PREVENTION
OIL SELLS
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Proa
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June 15-17,1971
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Printed in the United States of America
Library of Congress Catalog No. 74-124324
American Petroleum Institute
1801 K Street, N.W.
Washington, D. C. 20006
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CONTENTS
LAWS and ENFORCEMENT
Summary of Laws and Regulations Governing Spills and Discharges of Oil 3
William K. Tell, Jr., Texaco, Inc.
Oil Pollution Control Legislation and the Water Quality Improvement
Act of 1970 — The Federal Viewpoint 11
K. E. Biglane and R. H. Wyer, Division of Oil and Hazardous Materials, Water Quality
Office, Environmental Protection Agency
National Contingency Planning 17
Comdr. Daniel B. Charter, Jr., United States Coast Guard
International Activity Regarding Shipboard Oil Pollution Control 27
Capt. R. 1. Price, United States Coast Guard
The Oil Pollution Problem from the Viewpoint of Marine Insurance 43
Gordon W. Paulsen, Haight, Gardner, Poor & Havens
Should Financial Limitations Upon Liability Be
Applied to Oil Spill Removal and Damage? 49
C. R. Hallberg, United States Coast Guard
The Maine Law — A Precursor for the Oil Terminating States 53
William R. Adams, Environmental Improvement Commission, State of Maine
State Jurisdiction over OH Spills in a Federal System 57
Daniel Wilkes, University of Rhode Island
OIL SPILL PREVENTION, CONTROL, and MONITORING
Remote Sensing of Controlled Oil Spills 71
Clarence E. Catoe, United States Coast Guard I
Methods and Procedures for Preventing Oil Pollution
from Onshore and Offshore Faculties 85
R. D. Kaiser and H. D. Van Cleave, Environmental Protection Agency
Embroiled in Oil 91
Harold Bernard, Environmental Protection Agency
Prevention of Marine Pollution Through Understanding 97
Paul M. Hammer, Marine Advisory and Associated Services
Development of Tank Vessel Overfill Alarm Instruments 103
Donald J. Leonard, Shell Development Co.
iii
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The Use of a Gravity Type Oil Separator for Tanker Operations 109
R. O. Norris and W. H. Lockwood, Jr., Cities Service Tankers Corporation
Identification of Oil Leaks and Spills 119
R. E. Kreider, Standard Oil Company of California
Ballast Water Treatment — A Major Undertaking 125
Jonathan W. Scribner, Dept. of Health & Welfare, State of Alaska
Containment of OH by Sea Ice — Some Qualitative Aspects 133
F. G. Barber, Department of Fisheries and Forestry, Ottawa
Puget Sound Fisheries and Oil Pollution — A Status Report 139
Robert C. Clark and John S. Finley, Biological Laboratory, National Marine Fisheries
Service
A Joint State-Industry Program for Oil Pollution Control 147
Donald Corey, Division of Water Pollution Control, Massachusetts; Robert W. Neal and
Gerald R. Schimke, Arthur D. Little, Inc.
Alberta Ofl Spill Contingency Plan 157
7. G. Gainer, Canadian Petroleum Association
Development of an Air Deliverable Antipollntion Transfer System 165
Corrtdr. Robert J, Ketchel, United States Coast Guard and H. D. Smith, Goodyear Tire
and Rubber Co.
A Chemical Tagging System for Use in the Prevention of Oil Spills 179
Robert A. Landowne and Ralph B. Wainright, American Cyanamid Company
California Contingency Plan for Oil and Other Hazardous Materials Spills 183
John F. Matthews, Jr., Division of Oil and Gas, State of California
Role of the Oil Spill Cooperative in the Oil Producing Industry 191
5. C. Mut, Atlantic Richfield Co.
OD Spill Prevention and Detection Using an Instrumented Submersible 195
Wadsworth Owen, Vast, Inc. and William Leaf, Prototypes, Inc.
Causes of Oil Spills from Ships hi Port 199
W. H. Putman, Dept. of Fish and Game, State of California
Removal of Oil from Sunken Tankers 205
Vincent C. Rose and Gerald C. Soltz, University of Rhode Island
Ofl Versus Other Hazardous Substances 209
C. Hugh Thompson, Water Quality Office, Environmental Protection Agency
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Navy Harbor Oil Pollution Abatement 213
Jock E. Wilson, Naval Facilities Engineering Command
TREATING AGENTS
Sorbents for Oil Spill Removal 221
Paul Schatzberg and K. V. Nagy, Naval Ship and Development Laboratory
Laboratory Investigations into the Sinking of Oil Spills
with Participate Solids 235
O. Pordes, Egham Research Laboratories, U.K. and L. J. Schmit Jongbloed,
KominMijke/Shell Explordtie en Produktie Laboratorium, The Netherlands
Burning Agents for Ofl Spill Cleanup 245
Arnold Freiberger, Water Quality Office, Environmental Protection Agency
Assessment of Oil Spill Treating Agent Test Methods 253
/, R. Blacklaw, J. A. Strand and P. C. Walkup, Pacific Northwest Laboratories, Battelle
Memorial Institute
Oil Spill Dispersants — Current Status and Future Outlook 263
Gerard P. Canevari, Esso Research and Engineering Company
Dispersant Use vs Water Quality - 271
Richard T. Dewling, 7. Stephen Dorries and George Pence, Water Quality Office,
Environmental Protection Agency
Development of Toxicity Test Procedures for Marine Phytoplankton 279
John W. Strand, W. L. Templeton and I. A. Lichatowich, Pacific Northwest Laboratories,
Battelle Memorial Institute
Mkrobial Degradation of a Louisiana Crude Oil in Closed Flasks
and Undej: Simulated Field Conditions 287
Howard Kator, C. H. Oppenheimer and R. J. Miget, Florida State University
Toxicity of Oil-Dispersing Agents Determined in a Circulating Aquarium System 297
R. H. Engel and M. J. Neat, William F. Clapp Laboratories—Battelle Memorial
Institute
OH Spill Treatment With Composted Domestic Refuse 303
Walter G. Vaux, Stephen A. Weeks and Donald /. Walukas, Westinghouse Research
Laboratories
PHYSICAL REMOVAL and CONTAINMENT
A Study of the Performance Characteristics of the Oleophilic Belt Oil Scrubber 309
/. P. Oxenham, Shell Pipe Line Corporation
Free Vortex Recovery of Floating Oil 319
Eugene B. Nebeker and Sergio E. Rodriguez, Scientific Associates, Inc. and Paul G. Mikolaj,
Univ. of California—Santa Barbara
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Concept Development of a Powered Rotating Disk Oil Recovery System 329
5. T. Uyeda, R. L. Chuan, A. C. Connolly and Philip O. Johnson, Atlantic Research
Systems Division
Lockheed OO SpHl Recovery Device 339
Barrett Bruch, Lockheed Missiles & Space Co.
Development of Test Procedures for the Assessment of
Efficiency in Beach Cleaning 357
P. G. Jeffery, Warren Spring Laboratory, U.K.
Investigation of the Use of a Vortex Flow to Separate
Ofl from an Oil-Water Mixture 361
Arthur E. Mensing and Richard Stoeffler, United Aircraft Research Laboratories
"Dynamic KeeP Oil Containment System 369
Frank A. March, Ocean Systems, Inc.
Pneumatic Barriers for Oil Containment under Wind,
Wave and Current Conditions 381
David R. Basco, Texas A & M University
Theoretical and Experimental Evaluation of Ofl Spfll Control Devices 393
Wilbur Marks, Gunth R. Geiss and Jules Hirschman, Poseidon Scientific Corp.
Study of Equipment and Methods for Removing or
Dispersing Ofl from Open Waters 405
C. H. Henager, P. C. Walkup, J. R. Blacklaw and J. D. Smith, Pacific Northwest
Laboratories, Battelle Memorial Institute
The Recovery of Ofl from Water With Magnetic Liquids 415
R. Kaiser and G. Miskolezy, Avco Systems Division; C. K. Colton, Massachusetts
Institute of Technology and R. A. Curtis, Purdue Univ.
PHYSICAL-BIOLOGICAL EFFECTS
Some Effects of Ofl Pollution in Mflford Haven, United Kingdom 429
E. B. Cowell, Orielton Field Centre, U.K.
The Influence of Ofl and Detergents on Recolonization
in the Upper Intertidal Zone 437
Dale Straughan, Allan Hancock Foundation, University of Southern California
Sources and Biodegradation of Carcinogenic Hydrocarbons 441
Claude E. ZoBell, University of California—San Diego
Cleaning and Rehabilitation of Oiled Seabirds 453
G. Odham, Goteborgs University, Sweden
Initial Aging of Fuel Ofl Films on Sea Water 457
Craig L. Smith and William G. Maclntyre, Virginia Institute of Marine Science
vi
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Physical Processes in the Spread of Oil on a Water Surface 463
James A. Fay, Massachusetts Institute of Technology
The Physical Behavior of Oil on Water Derived from
Airborne Infrared and Microwave Radiometric Measurements 469
/. M. Kennedy, Resources Technology Corp. and E. G. Wermund, Remote Sensing, Inc.
Ofl Pollution Problems in the Arctic 479
Lt. (jg.) John L. Glaeser, United States Coast Guard
Effects of Exposure to Oil on Mytilus Californanus
From Different Localities 485
Robert Kanter, Dale Straughan and William lessee, Allan Hancock Foundation, University
of Southern California
The Movement of Oil Spills 489
Henry G. Schwartzberg, New York University
OIL SPILL CLEANUP
An Integrated Program for Oil Spill Cleanup 497
W. E. Belts and H. I. Fuller, Esso Research Center, V.K.; H. logger, Esso Petroleum Co.,
London
Evaluation of Selected Earthmoving Equipment for the
Restoration of Oil-Contaminated Beaches 505
James D. Sartor, URS Research Co.
Froth Flotation Cleaning of Ofl Contaminated Beaches 523
Garth D. Gumtz, Meloy Laboratories
A Hot Water Fluidization Process for Cleaning Oil-Contaminated Beach Sand 533
Paul G. Mikolaj and Edward J. Curran, University of California—Santa Barbara
The State's Role in Oil Spill Cleanup 541
John D. Harper, The Marsan Corporation
Vll
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LAWS AND ENFORCEMENT
Chairman: L. P. Haxby
Shell Oil Company
Co-Chairman: E. Cotton
Gulf Oil Corporation
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SUMMARY OF LAWS AND
REGULATIONS GOVERNING SPILLS AND
DISCHARGES OF OIL
William K. Tell, Jr.
Texaco, Inc.
INTRODUCTION
The past several years have seen a veritable explosion of
environmental laws and regulations, at all levels, federal,
state and local. In many instances the overall law in the area
has not evolved in an orderly manner. Legislatures, under
heavy popular pressures to enact forceful measures to
enhance the environment, have often acted precipitously
without insuring that the total fabric of laws and regula-
tions between the state and federal and local governments
was coordinated, consistent and non-duplicative. In certain
instances earlier laws not specifically tailored to today's
environmental problems have been stretched by the courts
to apply to polluters with perhaps commendable results in
the particular case at bar, but creating legal precedents
which are difficult to reconcile with other laws and
principles of statutory construction. Additional confusion
has been created by the large number of enforcement
agencies which have been brought into the picture at all
levels. These include the Environmental Protection Agency
(EPA), the Army Corps of Engineers, U.S. Coast Guard and
U.S. Geological Survey at the federal level and a multitude
of state and local agencies.
Further compounding the legal problems in the environ-
mental area has been the lack of adequate technical data on
the precise harmful effects of various pollutants. Legisla-
tures have generally felt lacking in-time or expertise to
resolve the complex issues, and therefore, have frequently
delegated responsibilities in this area to enforcement
agencies, often under extremely tight timetables for imple-
mentation. The result has too often been the adoption of
regulations based on superficial criteria which fail to
adequately appraise and reflect (1) the true extent of the
injury to the environment, (2) the technological capability
of industry to curtail its discharge of pollutants without
causing severe disruptions in employment and energy
supplies, (3) the time period reasonably required to install
such anti-pollutant devices, and (4) the ultimate cost to the
consumer. Unless realistic accommodations can be found in
these areas of potential conflict, and the public made better
informed on the price which it must pay for a cleaner
environment, what could and should be a proud chapter in
America's industrial revolution may end on a very sour note
for all.
This paper attempts to generally summarize the current
state of the law applicable to oil discharges. Unfortunately
the law in this area is evolving so rapidly that much of the
material contained herein reflecting events as of April 1,
1971 will be out of date by the time of the Oil Spill
Conference in mid-June. Since there are so many laws and
regulations in this field, my treatment of them has been
limited to a general description of the more significant
provisions in the interest of keeping this paper to manage-
able length. In many instances, however, the full text of the
statute or regulation with respect to these provisions has
been provided in an Appendix.
I. Federal Water Pollution Control Act Prior to 1970
The basic federal statute covering discharges of oils is the
Federal Water Pollution Control Act, 33 U.S.C., 1151 et
seq. This Act was originally enacted June 30, 1948 and
has been amended on several subsequent occasions, includ-
ing major revisions in 1956, 1965 and 1970.
Until the enactment of the Water Quality Improvement
Act of 1970, the Federal Water Pollution Control Act did
not specifically focus on the problem of oil discharges, nor
did it provide national effluent standards for oil or any
other substances. Instead, the Water Quality Act of 1965
amended the Water Pollution Control Act by requiring each
state to establish, and obtain federal approval of, water
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LAWS AND ENFORCEMENT
quality standards for the interstate waters within said
state.1 Thus, instead of effluent or discharge standards for
oil or any other substance, the statute provided for the
establishment of receiving water standards by each state.
Such standards, which have now received federal approval,
in whole or in part, for each state, normally do not contain
a precise criteria for allowable oil discharges. A typical state
standard regarding oil discharges would state that
"There shall be no slicks of free or floating oil
present in sufficient quantities to interfere with the
designated uses, nor shall emulsified oils be present
in sfuficient quantities to interfere with designated
uses."2
In addition to the absence of precise standards, federal
enforcement is limited to situations where the discharge has
caused a reduction in the quality of the receiving waters
below the standards set for that water body, or has polluted
the waters to the extent that it endangers the public health
or welfare. In the latter case, extended conference and
hearing procedures must be complied with before a lawsuit
to abate the violation can be commenced. In cases merely
involving alleged violations of receiving water standards no
such prerequisites to an enforcement proceeding are con-
templated by the 1965 Act.
n. Water Quality Improvement Act of 1970
Congress on April 3, 1970 enacted the Water Quality
Improvement Act of 1970, 33 U.S.CJV., 1161 et seq.3
amending the Federal Water Pollution Control Act in the
following major respects involving pollution by oil4:
1. The discharge of oil into or upon the navigable waters
of the United States, adjoining shorelines, or into or
upon the waters of the contiguous zone is prohibited
except in such "quantities and at times and locations
or under such circumstances or conditions as the
President may, by regulation, determine not to be
harmful." Regulations establishing permissible oil
discharges are to be "consistent with maritime safety
and with marine and navigation laws and regulations
and applicable water quality standards." Such regula-
tions are to determine "those quantities of oil the
discharge of which, at such times, locations, circum-
stances, and conditions, will be harmful to the public
health or welfare of the United States, including, but
not limited to, fish, wildlife, and public and private
property, shorelines, and beaches."
33 U.S.C.A., 1160. The pertinent provisions of the 1965 Act
are set forth in the Appendix hereto at pages i and ii.
2
Louisiana Water Quality Criteria and Plan for Implementation.
The pertinent provisions of the Act are set forth in the
Appendix hereto at pages iii-v.
Section 1 l(a) defines oil to mean "oil of any kind or in any
form, including, but not limited to, petroleum, fuel oil, sludge, oil
refuse, and oil mixed with wastes other than dredged spoil."
2. Any person in charge of a vessel or of an onshore or
offshore facility shall immediately notify the U.S.
Coast Guard of any discharge of oil in harmful
quantities. Failure to make immediate notification
shall be subject to fine of not more than $10,000, or
imprisonment for not more than one year, or both.
3. Any owner or operator of any vessel, onshore facility
or offshore facility from which oil is knowingly
discharged io harmful quantities shall be assessed a
civil penalty of not more than $10,000 for each
offense. Each violation is a separate offense.
4. An owner or operator of a vessel or offshore or
onshore facility shall be liable to the United States
Government for reimbursement of costs incurred in
the removal of oil discharges up to limits for vessels
of $100 per gross ton or $14 million, whichever is
lesser, and for onshore and offshore facilities up to
$8 million. If it is established that a discharge was the
result of willful negligence or willful misconduct
within the privity and knowledge of the owner, the
above limitations on liability shall not apply. Excep-
tions to liability for clean-up costs are granted where
an owner or operator can prove the discharge was
caused solely by (1) an act of God, (2) an act of war,
(3) negligence on the part of the United States
Government, or (4) an act or omission of a third
party. The provisions of the Act with respect to
clean-up cost and other procedures do not apply to
offshore facilities on the Outer Continental Shelf
which are covered separately by Interior Department
regulations promulgated under the Outer Continental
Shelf Lands Act and discussed in Section HI, infra.
5. Adoption of a National Contingency Plan adminis-
tered by the U.S. Coast Guard containing regulations
prescribing methods and procedures for the removal
and prevention of discharge of oil. Violations of such
regulations are subject to a civil penalty of not more
than $5,000 for each violation.
6. Establishment of a $35 million revolving fund to
cover costs incurred by the Government in arranging
for the removal of discharged oil (the Government
having the right to recover any such costs incurred
from the discharging party within the limits described
in Paragraph 3 above).
7. Any applicant for a federal license or permit to
conduct an activity which may result in the discharge
of oil into the navigable waters of the United States
must provide the licensing agency with a certificate
from the state in which the discharge originates, or
the applicable interstate water pollution control
agency having jurisdiction, that there is reasonable
assurance such activity will not violate applicable
water quality standards. The proposed regulations
under this provision (Vol. 36, Federal Register, No.
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SUMMARY OF LAWS . . .
25, page 2516, et seq.} define "license or permit" to
include leases for oil, minerals, or other exploitation.
8. Abatement actions may be initiated by a U.S.
Attorney if there is "an imminent and substantial
threat to the public health or welfare of the United
States, including, but not limited to, fish, shellfish,
and wildlife and public and private property, shore-
lines and beaches" because of a threatened or actual
discharge of oil.
The regulations promulgated by the Secretary of the
Interior pursuant to Section 1 l(bX3) of the Water Quality
Improvement Act of 1970 define prohibited discharges of
oil in quantities harmful to the public health and welfare as
being those which "(a) violate applicable water quality
standards, or (b) cause a film or sheen upon or discolora-
tion of the surface of water or adjoining shorelines or cause
a sludge or emulsion to be deposited beneath the surface of
the water or upon adjoining shorelines." 35 Federal
Register, 14307 (Sept. 11, 1970). Literally applied such
regulations would prohibit all oil discharges since even small
quantities of oil under certain weather and water conditions
will produce a sheen or discoloration. Strict enforcement of
the regulations would require shutting in substantial quanti-
ties of offshore oil production since minute quantities of oil
are contained in the discharges of brine produced with the
oil.
Following the issuance of the Interior Department
regulations defining "harmful quantities" of oil, petitions
were filed by a number of major producing companies
urging that such regulations be modified on the grounds of
the impracticality and unworkability of the "sheen" stan-
dard. The petitions pointed out that to the extent such
regulations prohibited all discharges of oil they were in
conflict with the legislative history of the Act which
contemplated that certain controlled discharges would be
permitted if they were consistent with applicable state
water quality standards, rules and regulations. Authority
for the administration of the Federal Water Quality
Improvement Act was transferred to the Environmental
Protection Agency on December 1, 1970 and as of the time
this paper was prepared such Agency had not acted on the
pending petitions.
III. Interior Department - Outer Continental
Shelf Regulations
On August 22, 1969, the Interior Department promul-
gated regulations under the Outer Continental Shelf Lands
Act, 43 U.S.C. 1331 et seq., governing oil and gas leasing
operations on the Outer Continental Shelf (30 CFR, Part
250 et seq; 43 CFR, Part 3380, et seq.}. These regulations
provide for, inter alia:
1. full consideration of all environmental factors by the
Interior Department before determining to offer oil,
gas and mineral leases for sale,
2. suspension of any producing operation which in the
judgment of the U.S. Geological Survey (U.S.G.S.)
threatens the environment,
3. prior review and approval by the U.S.G.S. of all plans
for exploration, drilling and development for the
prevention of pollution, blow-outs and leakage,
4. prompt reporting of leakage or spills to the Coast
Guard, EPA and the U.S.G.S.,
5. Imposition of obligations upon the lessee for the
control and total removal of any pollutant damaging
or threatening to damage, aquatic life, wildlife, or
public or private property.
The Water Quality Improvement Act of 1970 is not
applicable to offshore facilities in the Contiguous Zone (the
area seaward from the boundary of state ownership to the
12-mile limit) and such operations are controlled by the
Interior Department regulations set forth above.
IV. Refuse Act of 1899
The Refuse Act of 1899,5 although originally intended
to prevent navigational obstruction, has been used increas-
ingly in the pollution area. In essence the statute prohibits,
among other things, the discharge of refuse matter of any
kind into the navigable waters of the United States or their
tributaries, from any vessel or other floating craft, from the
shore, or from a wharf, manufacturing establishment or mill
of any kind. The prohibition does not apply to refuse
flowing from streets or sewers in a liquid state. Violations
are misdemeanors punishable by a $500 to $2,500 fine
and/or imprisonment for up to one year. Under a literal
reading of the statute, if the Secretary of the Army believes
that a particular discharge will not injure navigation, he
may permit said discharge under such limits and conditions
as are prescribed by him.
The 1899 Act appears to affect the problem of oil
discharges in the following manner:
1. The 1899 Act was not superseded by the Water
Quality Improvement Act of 1970, although some persons
have attempted—without success—to convince the courts
otherwise6. The statute and case law relating thereto
therefore are still applicable to oil discharges, both of
accidental and chronic origin.
2. Case law has extended the concept of "refuse"
beyond waste materials to valuable products, such as
gasoline7.
3. Case law also has extended relief under the statute
beyond the above-mentioned criminal sanctions to injunc-
tive relief in a civil action8. Therefore, although the Water
Quality Improvement Act of 1970 did not provide for
injunctive relief against discharges of oil in harmful quanti-
ties, except with respect to discharges determined by the
33 U.S.C.A. 407. The full text of the Act is set forth in the
Appendix hereto at page vii.
617.5. v. Vulcan Materials Co., 2 ERC 1145 (D.N.J. Sept 24,
1970).
7U.S. v. Standard Oil Co., 384 U.S. 224 (1966).
8E.G., U.S. v. Republic Steel Corp., 286 F.2d 875 (6th Cir.
1961); U.S. v. Florida Power & Light Co., 311 F. Supp. 1391 (D.
Fla. 1970).
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LAWS AND ENFORCEMENT
President as creating an imminent and substantial threat to
the public health or welfare, the Government can utilize the
1899 Act to obtain such relief.
4. It has been argued that industrial discharges con-
taining oil but not solids are not prohibited by the 1899
Act because such discharges flow from "sewers" and the
statute exempts refuse flowing from sewers in a liquid state.
Existing case law, however, has interpreted the exemption
as being limited to domestic—as distinguished from industri-
al—sewage9.
5. The Department of the Army, in coordination with
the Environmental Protection Agency, has commenced a
federal permit program for industrial discharges under the
statute, and has adopted regulations to implement that
program. All facilities affected by the permit program are
to apply for such permits no later than July 1, 1971. The
primary issue to be determined in processing permit
applications is whether a specific discharge is consistent
with "applicable water quality standards and related water
quality considerations, including environmental values re-
flected in water quality standards." This criterion, the
determination of which is to be in the hands of the
Environmental Protection Agency rather than the Army
Corps of Engineers, allows the federal authorities to go
beyond the state certification of compliance with water
quality standards that must be provided to the federal
authorities in order for a permit to issue10. Yet no
standards whatever are provided in the 1899 Act (which
speaks in the context of obstructions to navigation) or the
regulations as the basis under which the federal determina-
tion on this issue is to be made. With respect to oil
discharges, the regulations may provide some clearer guid-
ance, in that they also state that "no permit will be
issued.. .for discharges or deposits of harmful quantities of
oil, as defined pursuant to Section 11 of the Federal Water
Pollution Control Act." Presumably the standards to be
observed regarding oil contained in the discharges subject to
the permit program are to be established by the anticipated
revision by EPA of the regulations originally promulgated
by the Interior Department (see Sec. II, supra) defining
"harmful" discharges of oil pursuant to the aforesaid
Section 11 of the 1970 Act. Until that revision is adopted,
v. Vulcan Materials Co., op. cit. supra. See also U.S. v.
Republic Steel Corp., op. cit. supra.
10In a tetter to the Editor of the New York Times dated March
24, 1971, William D. Ruckelshaus, Administrator of the Environ-
mental Protection Agency, outlined the circumstances in which the
agency would override state certification:
"White encouraging the fullest assumption of responsibil-
ity by state agencies, E.P.A. will override state recommenda-
tions and apply appropriate water quality standards in these
key cases:
Where no state standard exists, or where existing state
standards contain loopholes.
Where hazardous or toxic materials are discharged.
Where state water quality standards are inadequate to
protect valuable fish and wildlife or their habitats.
In any case where the applicable state standard is so weak
as to be inconsistent with the purposes of the Federal Water
Pollution Control Act"
however, applicants will be without any means of determin-
ing whether de minimis amounts of oil contained in their
discharges will be a basis for rejecting their applications.
6. The scope of the 1899 Act prohibition clearly is
limited to "discharges from vessels and other floating craft,
from the shore, and from wharfs, manufacturing establish-
ments, and mills of any kind." Therefore, neither the
statute nor the regulations can legitimately be extended to
certain categories of petroleum operations, such as dis-
charges or deposits from drilling or production facilities
operating offshore or in inland waters, except to the extent
that such facilities discharge refuse from a shoreline or
wharf11. Nevertheless, the aforesaid regulations implement-
ing the permit program do not appear to recognize this
limitation. Instead they explicitly state that the 1899 Act is
considered to apply to all discharges or deposits into a
navigable waterway or tributary, although for policy
reasons discharges from and into certain government waste
treatment systems, and discharges from ships and other
watercraft, are excluded from the permit program. This
point of controversy has not, to my knowledge, been dealt
with by the courts as of the date of this writing.
V. State Oil Pollution Legislation
1970 was a year of significant legislative activity on the
state, as well as federal, level with respect to oil pollution.
Four states—Florida, Maine, Massachusetts and
Washington—enacted far-reaching oil pollution statutes12.
Those statutes, which apply to oil spills from vessels and
other facih'ties located within the coastal waters and other
areas of jurisdiction of the respective states, provide for
strict liability, without proof of negligence, not only for
reimbursement of state-incurred clean-up costs, but also for
damages to the environment and to third parties. The state
statutes contain no defenses from strict liability, except for
Washington, which provides relief from strict liability if it
can be established that the discharge was caused by an act
of war or by negligence on the part of the federal or state
government. The state statutes also differ from the federal
statute in that such liability is unlimited in amount. Other
far-reaching provisions contained in some of the state
statutes include: (1) extending liability beyond the vessel
operator to the cargo owner (Mass.), (2) extending liability
to the terminal operator for discharges from vessels
approaching or leaving said terminals (Maine), and (3)
imposing a terminal license fee of one-half cent barrel of oil
transferred (Maine).
Such discharges, however, are regulated by the Water Quality
Improvement Act and Interior Department OCS regulations dis-
cussed in Sections II and III, supra.
12Florida Oil Spill Prevention and Pollution Act; Maine Oil
Discharge Prevention and Pollution Control Act, 16 Me. Rev. Stat
§§541 et seq.; Mass. Clean Waters Act; Wash. Water Pollution
Control Act, RCWA Ch. 90.48 et. seq.
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SUMMARY OF LAWS . . .
The efforts of various states to superimpose their own
(and often duplicative) statutory schemes upon prior
obligations created by federal law are a matter of serious
concern for the petroleum, marine and other industries.
The question of whether and the extent to which prior
federal action in the pollution field may have preempted or
otherwise Constitutionally bar the states from enacting
pollution legislation is a matter presently under judicial
consideration in lawsuits challenging the constitutionality
of the Florida and Maine statutes. As of April 1, 1970,
court orders were in effect restraining the enforcement of
the Florida statute and certain essential provisions of the
Maine statute, pending a full hearing on the constitutional-
ity of this legislation.
VI. Pending Federal Legislation
Numerous bills designed to strengthen existing federal
water pollution legislation have been introduced in Con-
gress this year. Foremost among them, perhaps, are the
Administration bill introduced by Senator Cooper (S.
1014), and the bill introduced by Senator Muskie (S. 523).
By looking at both bills, it is possible to anticipate the
types of substantive changes which may occur in federal
water pollution legislation in the near future.
Amendments can be foreseen to Section 10 of the Water
Pollution Control Act to provide for uniform national
federal water quality criteria and effluent standards, as well
as federally recommended pollution control techniques
based on the latest technology and economic feasibility of
alternate methods of control. The states may be given 9
months to a year in which to submit to EPA, for its
approval, procedures and plans to implement, administer
and enforce such national standards. New facilities may be
required to be constructed with the latest available pollu-
tion control techniques and certified as to compliance with
applicable water quality standards. Violations will be
subject to very severe monetary penalties, as well as
abatement, and, additionally, may be the basis for citizen
suits as well as actions commenced by EPA.
APPENDIX
Pertinent Provisions of 1965 Act Amendments
To Water Pollution Control Act
SEC. 10. (a) The pollution of interstate or navigable
waters in or adjacent to any State or States (whether the
matter causing or contributing to such pollution is dis-
charged directly into such waters or reaches such waters
after discharge into a tributary of such waters), which
endangers the health or welfare of any persons, shall be
subject to abatement as provided in this Act.
(b) Consistent with the policy declaration of this Act,
State and interstate action to abate pollution of interstate
or navigable waters shall be encouraged and shall not,
except as otherwise provided by or pursuant to court order
under subsection (h), be displaced by Federal enforcement
action.
If the Governor of a State or a State water
pollution control agency files, within one year after the
date of enactment of this subsection, a letter of intent that
such State, after public hearings, will before June 30,1967,
adopt (A) water quality criteria applicable to interstate
waters or portions thereof within such State, and (B) a plan
for the implementation and enforcement of the water
quality criteria adopted, and if such criteria and plan are
established in accordance with the letter of intent, and if
the Secretary determines that such State criteria and plan
are consistent with paragraph (3) of this subsection, such
State criteria and plan shall thereafter be the water quality
standards applicable to such interstate waters or portions
thereof.
* * *
(5) The discharge of matter into such interstate waters
or portions thereof, which reduces the quality of such
waters below the water quality standards established under
this subsection (whether the matter causing or contributing
to such reduction is discharged directly into such waters or
reaches such waters after discharge into tributaries of such
waters), is subject to abatement in accordance with the
provisions of paragraph (1) or (2) of subsection (g) of this
section, except that at least 180 days before any abatement
action is initiated under either paragraph (1) or (2) of
subsection (g) as authorized by this subsection, the Secre-
tary shall notify the violators and other interested parties of
the violation of such standards. In any suit brought under
the provisions of this subsection the court shall receive in
evidence a transcript of the proceedings of the conference
and hearing provided for in this subsection, together with
the recommendations of the conference and Hearing Board
and the recommendations and standards promulgated by
the Secretary, and such additional evidence, including that
relating to the alleged violation of the standards, as it deems
necessary to a complete review of the standards and to a
determination of all other issues relating to the alleged
violation. The court, giving due consideration to the
practicability and to the physical and economic feasibility
of complying with such standards, shall have jurisdiction to
enter such judgment and orders enforcing such judgment as
the public interest and the equities of the case may require.
* * *
(g) If action reasonably calculated to secure abatement
of the pollution within the time specified in the notice
following the public hearing is not taken, the Secretary-
(1) in the case of pollution of waters which is
endangering the health or welfare of persons in a State
other than that in which the discharge or discharges
(causing or contributing to such pollution) originate,
may request the Attorney General to bring a suit on
behalf of the United States to secure abatement of
pollution, and
(2) in the case of pollution of waters which is
endangering the health or welfare of persons only in the
State in which the discharge or discharges (causing or
contributing to such pollution) originate, may, with the
written consent of the Governor of such State, request
the Attorney General to bring a suit on behalf of the
United States to secure abatement of the pollution.
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LAWS AND ENFORCEMENT
Pertinent Provisions of 1970 Act
Amendments To Water Pollution Control Act
Section ll(b)
(1) The Congress hereby declares that it is the policy of
the United States that there should be no discharges of oil
into or upon the navigable waters of the United States,
adjoining shorelines, or into or upon the waters of the
contiguous zone.
(2) The discharge or oil into or upon the navigable
waters of the United States, adjoining shorelines, or into or
upon the waters of the contiguous zone in harmful
quantities as determined by the President under paragraph
(3) of this subsection, is prohibited, except (A) in the case
of such discharges into the waters of the contiguous zone,
where permitted under article IV of the International
Convention for the Prevention of Pollution of the Sea by
Oil, 1954, as amended, and (B) where permitted in
quantities and at times and locations or under such
circumstances or conditions as the President may, by
regulation, determine not to be harmful. Any regulations
issued under this subsection shall be consistent with
maritime safety and with marine and navigation laws and
regulations and applicable water quality standards.
(3) The President shall, by regulation, to be issued as
soon as possible after the date of enactment of this
paragraph, determine for the purposes of this section, those
quantities of oil the discharge of which, at such times,
locations, circumstances, and conditions, will be harmful to
the public health or welfare of the United States, including,
but not limited to, fish, shellfish, wildlife, and public and
private property, shorelines, and beaches, except that in the
case of the discharge of oil into or upon the waters of the
contiguous zone, only those discharges which threaten the
fishery resources of the contiguous zone or threaten to
pollute or contribute to the pollution of the territory or the
territorial sea of the United States may be determined to be
harmful.
(4) Any person in charge of a vessel or of an onshore
facility or an offshore facility shall, as soon as he has
knowledge of any discharge of oil from such vessel or
facility in violation of paragraph (2) of this subsection,
immediately notify the appropriate agency of the United
States Government of such discharge. Any such person who
fails to notify immediately such agency of such discahrge
shall, upon conviction, be fined not more than $10,000, or
imprisoned for not more than one year, or both. Notifica-
tion received pursuant to this paragraph or information
obtained by the exploitation of such notification shall not
be used against any such person in any criminal case, except
a prosecution for perjury or for giving a false statement
(5) Any owner or operator of any vessel, onshore
facility, or offshore facility from which oil is knowingly
discharged in violation of paragraph (2) of this subsection
shall be assessed a civil penalty by the Secretary of the
department in which the Coast Guard is operating of not
more than $10,000 for each offense. No penalty shall be
assessed unless the owner or operator charged shall have
been given notice and opportunity for a hearing on such
charge. Each violation is a separate offense. Any such civil
penalty may be compromised by such Secretary. In
determining the amount of the penalty, or the amount
agreed upon in compromise, the appropriateness of such
penalty to the size of the business of the owner or operator
charged, the effect on the owner or operator's ability to
continue in business, and the gravity of the violation, shall
be considered by such Secretary. The Secretary of the
Treasury shall withhold at the request of such Secretary the
clearance required by section 4197 of the Revised Statutes
of the United States, as amended (46 U.S.C. 91), of any
vessel the owner or operator of which is subject to the
foregoing penalty. Clearance may be granted in such cases
upon the filing of a bond or other surety satisfactory to
such Secretary.
(cXO Whenever any oil is discharged, into or upon the
navigable waters of the United States, adjoining shorelines,
or into or upon the waters of the contiguous zone, the
President is authorized to act to remove or arrange for the
removal of such oil at any time, unless he determines such
removal will be done properly by the owner or operator of
the vessel, onshore facility, or offshore facility from which
the discharge occurs.
Section 11 (e)
(e) In addition to any other action taken by a State or
local government, when the President determines there is an
imminent and substantial threat to the public health or
welfare of the United States, including, but not limited to,
fish, shellfish, and wildlife and public and private property,
shorelines, and beaches within the United States, because of
an actual or threatened discharge of oil into or upon the
navigable waters of the United States from an onshore or
offshore facility, the President may require the United
States attorney of the district in which the threat occurs to
secure such relief as may be necessary to abate such threat,
and the district courts of the United States shall have
jurisdiction to grant such relief as the public interest and
the equities of the case may require.
(fXO Except where an owner or operator can prove
that a discharge was caused solely by (A) an act of God, (B)
an act of war, (C) negligence on the part of the United
States Government, or (D) an act or omission of a third
party without regard to whether any such act or omission
was or was not negligent, or any combination of the
foregoing clauses, such owner or operator of any vessel
from which oil is discharged in violation of subsection
(bX2) of this section shall, notwithstanding any other,
provision of law, be liable to the United States Government
for the actual costs incurred under subsection (c) for the
removal of such oil by the United States Government in an
amount not to exceed $100 per gross ton of such vessel or
$14,000,000, whichever is lesser, except that where the
United States can show that such discharge was the result
of willful negligence or willful misconduct within the
privity and knowledge of the owner, such owner or
operator shall be liable to the United States Government
for the full amount of such costs. Such costs shall
constitute a maritime lien on such vessel which may be
recovered in an action in rem in the district court of the
United States for any district within which any vessel may
be found. The United States may also bring an action
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SUMMARY OF LAWS . . .
against the owner or operator of such vessel in any court of
competent jurisdiction to recover such costs.
(2) Except where an owner or operator of an onshore
facility can prove that a discharge was caused solely by (A)
an act of God, (B) an act of war, (C) negligence on the part
of the United States Government, or (D) an act or omission
of a third party without regard to whether any such act or
omission was or was not negligent, or any combination of
the foregoing clauses, such owner or operator of any such
facility from which oil is discharged in violation of
subsection (bX2) of this section shall be liable to the
United States Government for the actual costs incurred
under subsection (c) for the removal of such oil by the
United States Government in an amount not to exceed
$8,000,000, except that where the United States can show
that such discharge was the result of willful negligence or
willful misconduct within the privity and knowledge of the
owner, such owner or operator shall be liable to the United
States Government for the full amount of such costs. The
United States may bring an action against the owner or
operator of such facility in any court of competent
jurisdiction to recover such costs. The Secretary is autho-
rized, by regulations, after consultation with the Secretary
of Commerce and the Small Business Administration, to
establish reasonable and equitable classifications of those
onshore facilities having a total fixed storage capacity of
1,000 barrels or less which he determines because of size,
type, and location do not present a substantial risk of the
discharge of oil in violation of subsection (bX2) of this
section, and apply with respect to such classifications
differing limits of liability which may be less than the
amount contained in this paragraph.
(3) Except where an owner or operator of an offshore
faculty can prove that a discharge was caused solely by (A)
an act of God, (B) an act of war, (C) negligence on the part
of the United States Government, or (D) an act or omission
of a third party without regard to whether any such act or
omission was or was not negligent, or any combination of
the foregoing clauses, such owner or operator of any such
facility from which oil is discharged, in violation of
subsection (bX2) of this section shall, notwithstanding any
other provision of law, be liable to the United States
Government for the actual costs incurred under subsection
(c) for the removal of such oil by the United States
Government in an amount not to exceed $8,000,000,
except that where the United States can show that such
discharge was the result of willful negligence or willful
misconduct within the privity and knowledge of the owner,
such owner or operator shall be liable to the United States
Government for the full amount of such costs. The United
States may bring an action against the owner or operator of
such a facility in any court of competent jurisdiction to
recover such costs.
Section 21(b)(l)
(bXO Any applicant for a Federal license or permit to
conduct any activity including, but not limited to, the
construction or operation of facilities, which may result in
any discharge into the navigable waters of the United
States, shall provide the licensing or permitting agency a
certification from the State in which the discharge origi-
nates or will originate, or, if appropriate, from the
interstate water pollution control agency having jurisdiction
over the navigable waters at the point where the discharge
originates or will originate, that there is reasonable assur-
ance, as determined by the State or interstate agency that
such activity will be conducted in a manner which will not
violate applicable water quality standards. Such State or
interstate agency shall establish procedures for public
notice in the case of all applications for certification by it,
and to the extent it deems appropriate, procedures for
public hearings in connection with specific applications. In
any case where such standards have been promulgated by
the Secretary pursuant to section 10(c) of this Act, or
where a State or interstate agency has no authority to give
such a certification, such certification shall be from the
Secretary. If the State, interstate agency, or Secretary, as
the case may be, fails or refuses to act on a request for
certification, within a reasonable period of time (which
shall not exceed one year) after receipt of such request, the
certification requirements of this subsection shall be waived
with respect to such Federal application. No license or
permit shall be granted until the certification required by
this section has been obtained or has been waived as
provided in the preceding sentence. No license or permit
shall be granted if certification has been denied by the
State, interstate agency, or the Secretary, as the case may
be.
Pertinent Provisions of Interior Department Outer
Continental Shelf Lands Act Regulations
§250.43 Pollution and waste disposal.
(a) The lessee shall not pollute land or water or damage
the aquatic life of the sea or allow extraneous matter to
enter and damage any mineral- or water-bearing formation.
The lessee shall dispose of all liquid and nonliquid waste
materials as prescribed by the supervisor. All spills or
leakage of oil or waste materials shall be recorded by the
lessee and, upon request of the supervisor, shall be reported
to him. All spills or leakage of a substantial size or quantity,
as defined by the supervisor, and those of any size or
quantity which cannot be immediately controlled also shall
be reported by the lessee without delay to the supervisor
and to the Coast Guard and the Regional Director of the
Federal Water Pollution Control Administration. All spills
or leakage of oil or waste materials of a size or quantity
specified by the designee under the pollution contingency
plan shall also be reported by the lessee without delay to
such designee.
(b) If the waters of the sea are polluted by the drilling or
production operations conducted by or on behalf of the
lessee, and such pollution damages or threatens to damage
aquatic life, wildlife, or public or private property, the
control and total removal of the pollutant, wheresoever
found, proximately resulting therefrom shall be at the
expense of the lessee. Upon failure of the lessee to control
and remove the pollutant the supervisor, in cooperation
with other appropriate agencies of the Federal, State and
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10
LAWS AND ENFORCEMENT
local governments, 01 in cooperation with the lessee, or
both, shall have the right to accomplish the control and
removal of the pollutant in accordance with any established
contingency plan for combating oil spills or by other means
at the cost of the lessee. Such action shall not relieve the
lessee of any responsibility as provided herein.
(c) The lessee's liability to third parties, other than for
cleaning up the pollutant in accordance with paragraph (b)
of this section shall be governed by applicable law.
Refuse Act of 1899
It shall not be lawful to throw, discharge, or deposit, or
cause, suffer, or procure to be thrown, discharged, or
deposited either from or out of any ship, barge, or other
floating craft of any kind, or from the shore, wharf,
manufacturing establishment, or mill of any kind, any
refuse matter of any kind or description whatever other
than that flowing from streets and sewers and passing
therefrom in a liquid state, into any navigable water of the
United States, or into any tributary of any navigable water
from which the same shall float or be washed into such
navigable water; and it shall not be lawful to deposit, or
cause, suffer, or procure to be deposited material of any
kind in any place on the bank of any navigable water, or on
the bank of any tributary of any navigable water, where the
same shall be liable to be washed into such navigable water,
either by ordinary or high tides, or by storms of floods, or
otherwise, whereby navigation shall or may be impeded or
obstructed: Provided, That nothing herein contained shall
extend to, apply to,- or prohibit the operations in connec-
tion with public works, considered necessary and proper by
the United States officers supervising such improvement or
public work: And provided further, That the Secretary of
the Army, whenever in the judgment of the Chief of
Engineers anchorage and navigation will not be injured
thereby, may permit the deposit of any material above
mentioned in navigable waters, within limits to be defined
and under conditions to be prescribed by him, provided
application is made to him prior to depositing such
material; and whenever any permit is so granted the
conditions thereof shall be strictly complied with, and any
violation thereof shall be unlawful.
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OIL POLLUTION CONTROL LEGISLATION
AND THE WATER QUALITY IMPROVEMENT
ACT OF 1970, THE FEDERAL VIEWPOINT
K.E. Biglane and R.H. Wyer
Division of Oil and Hazardous Materials
Water Quality Office
Environmental Protection Agency..
ABSTRACT
The Water Quality Improvement Act of 1970 was
enacted and signed into law on April 3, 1970. This Act
provides the mechanism for strong Federal actions relating
to oil removal, prevention and enforcement. This paper
discusses the most significant provisions of the Act and
describes the Federal point of view relating to key
provisions. Emphasis is placed on the rationale behind the
designation of a harmful quantity of oil, the impact of the
notification requirement, adequacy of oil removal
procedures, prevention of spills, and enforcement
provisions.
INTRODUCTION
It is significant to note that oil, as a specific polluter of
water, received early attention by the Congress with the
passage of the Oil Pollution Act of 1924. Although the
Refuse Act of 1899 (33 U.S.C.A. 407) is generally regarded
as the forerunner of water pollution control legislation in
this country, the discharge of oil into navigable water was
not declared a violation under this statute until 1936 (La
Merced, 84F. 2d 444). It is also significant to note that the
prohibitive section of these two statutes did not specify the
amounts of oil (or refuse) which, when discharged,
constituted a violation although under the 1924 Act the
Secretary of War (and later on, the Secretary of the
Interior) were authorized to prescribe permissible limits for
discharge.
Violators of the 1924 Act were assessed a criminal
penalty of no more that $2,500. The Act was moderately
successful from the standpoint of taking punitive action
against a discharger but the environment still suffered the
impact of potentially toxic, oily materials. In recognition of
this, Congress amended the 1924 Act in 1966 and required
the violator to remove the oil from the navigable waters. If
the discharger failed to do so the Federal government was
authorized to take action and seek reimbursement for the
cost of cleanup. Thus, the concept of environmental
protection through direct cleanup actions was clearly
established. The punitive section of the Act was weakened,
however, by requiring proof of willful discharge. The
general attitude of the violator to this legislation was to
totally disclaim knowledge of the spill and this resulted in
increased numbers in the mystery spill category. Cleanup
efforts at first were minimal, however, response to spill
incidents increased significantly with ihe advent of
chemical emulsifiers. This technique was touted as a
cleanup method which could quickly remove the oil "from
the public's eye." The method was portrayed as simple, fast
and an easy remedy but it also permitted the oil to remain
in the environment with a potential for significantly
affecting vital marine resources. Suddenly, a new dimension
was added to the oil pollution problem - that is, the proper
method of treatment or removal of an oil spill from water
in order to protect the aquatic biota, beaches and
waterfowl. In recognition of this problem, industry and the
Federal government began ambitious research programs to
devise better methods to contain and cleanup oil spills and
to try and restore the environment once it became
despoiled.
For the three years following the TORREY CANYON,
emphasis was placed on oil cleanup, new removal methods
and techniques, contingency planning and cleanup
cooperatives. State legislation and local ordinances began to
evolve with emphasis in these areas but the number of spills
continued to increase, unknown sources were
commonplace, and only punitive action through the 1899
Refuse Act was available to the government to curb the
11
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12
LAWS AND ENFORCEMENT
now increasing oil pollution problem. Also, during this
period an additional dimension emerged - an almost
overpowering public concern over the impact of water and
air pollution on our environment.
Water Quality Improvement Act 1970
In recognition of the deficiencies of existing legislation,
the need for effective enforcement, additional liability for
vessels and facilities, and methods to prevent the discharge
of oil, the Water Quality Improvement Act was enacted and
subsequently signed into law on April 3, 1970. The most
significant provisions of Section 11 of the Act state that:
a. The Federal government established by regulation
that quantity of oil determined to be harmful.
b. A person in charge of a vessel,.or an onshore or
offshore facility who fails to immediately notify the
appropriate Federal agency of a harmful discharge of
oil, can upon conviction be fined up to $10 thousand
or imprisoned for one year or both.
c. The owner or operator of a vessel, or an onshore or
offshore facility from which oil is knowingly
discharged can be assessed a civil penalty of up to
$10,000 for each offense.
d. The owner or operator of a vessel which discharges a
harmful quantity of oil can be held liable to the U.S.
Government for cleanup costs in an amount not to
exceed $100 per gross ton of the vessel or $14
million, whichever is less.
e. The owner or.operator of an onshore facility or
offshore facility which discharges a harmful quantity
of oil can be held liable for cleanup costs in an amount
not to exceed $8 million.
f. The Federal government may remove discharged oil
from the navigable waters and the contiguous zone at
any time, unless it is determined the owner or
operator is properly removing the discharged oil.
g. The Federal government will prepare and publish a
National Contingency Plan which shall provide for
effective action to minimize damages from oil
discharges including surveillance systems,
containment methods, removal procedures, and a
schedule designating use of dispersants.
h. The Federal government may remove or destroy a
vessel involved in a marine disaster in navigable waters
and take action against onshore and offshore facilities
which present an imminent and substantial oil
pollution threat.
i. The Federal government shall issue regulations
establishing methods and procedures for the removal
of oil; procedures, methods and requirements for
equipment to prevent discharges; and, governing the
inspection of vessels carrying cargoes of oil.
j. The owner or operator of a vessel or an onshore or
offshore facility who fails to comply with the
provisions of the regulations shall be liable to civil
penalty of not more than $5 thousand for each
violation.
k. The owner or operator of vessels over three hundred
gross tons shall provide evidence of financial
responsibility of $100 per gross ton of the vessel or
$14 million whichever is the lesser.
Harmful Discharge
The first and most significant task facing the Federal
government after passage of the Act was to define, under
Section 11, that quantity of oil that is harmful to public
health and welfare. The definition of a harmful quantity
was the key to activating the operational provisions of
Section 11. The widespread spills resulting from the
TORREY CANYON, the OCEAN EAGLE and the Santa
Barbara blowout were obviously harmful discharges but the
chronic, small discharges from both onshore and offshore
facilities are less obvious and, are believed to have the most
serious and long term effects on the environment. Because
of the far reaching impact of this regulation a discussion of
the rationale used to define that quantity is important. The
nation's of the world, the United States Government,
individual States and industry all recognize the need to
protect the environment, but the degree of protection
considered adequate by each is highly variable.
The amendments to the International Convention for
Prevention of Pollution of the Seas by Oil, 1954, as
amended in 1962 and 1969, reflect the worldwide concern
for preventing damage to the oceans by petroleum and its
by-products. The principal changes affecting tankers specify
that:
a. The instantaneous rate of discharge of oil content
does not exceed 60 litres per mile.
b. The total quantity of oil discharged on a ballast
voyage does not exceed 1/15,000 of the total
cargo-carrying capacity.
c. The tanker is more than 50 miles from the nearest
land when discharging.
The amendments of the Convention also state that
these provisions do not apply to the discharge of ballast
from tanks so cleaned that the effluent would produce no
visible traces of oil on the surface of clean calm water on a
clear day.
At the Brussels NATO meeting in 1970, the United
States took the initiative and achieved wide international
support for terminating all intentional discharges of oil and
oily wastes from ships into the ocean by 1970, if possible,
and by no later than the end of this decade. The intent of
these agreements is to eliminate the discharge of oil into the
high seas.
In 1965, the Federal Water Pollution Control
Administration initiated an intensive program to define
limits of toxic materials and other pollutants to the aquatic
biota. With the passage of the Water Quality Act of 1965,
the Secretary of the Interior established the National
Technical Advisory Committee on Water Quality Criteria.
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LEGISLATION AND THE ACT OF 1970
13
The subcommittee for Fish, Other Aquatic Life and
Wildlife consisting of 29 scientists and leaders of the field
recommend the following be adopted:
"Until more information on the chemistry and
toxicology of oil in sea water becomes available, the
following requirements are recommended for the
protection of marine life. No oil or petroleum
products should be discharged into estuarine or
coastal waters in quantities that (1) can be detected
as a visible film or sheen, or by odor, (2) cause
tainting of fish and/or edible invertebrates, (3) form
an oil-sludge deposit on the shores or bottom of the
receiving body of water, or (4) become effective
toxicants according to the criteria recommended in
the "Toxicity" section."
The subcommittee for Recreation and Aesthetics
recommended, among other criteria, that surface waters
should be free of substances attributable to discharges of
waste such as floating debris, oil, scum and other matter. It
is also interesting to note that the majority of the states
now include this criteria under the general provisions
category of State Water Quality Standards. Other sections
of the State Water Quality Standards prohibit the discharge
of toxic materials; however, quantitative limits for oil and
some other toxic materials such as mercury have not been
established.
With the passage of the Water Quality Act of 1970,
Congress delcared that it was the policy of the United
States that there should be no discharges of oil into or upon
the navigable waters of the United States, adjoining
shorelines, or into or upon the waters of the contiguous
zone and called for the President to issue regulations
defining that quantity of oil which will he harmful. The
regulations were published on September 11,1970. They
state that a harmful discharge of oil is one which violates
applicable Water Quality Standards or causes a sheen or
discoloration on the surface of the water.
The existing regulations defining a harmful quantity
should not be interpreted as being absolute. Both the
Federal government and industry are expending research
funds to better define the harmful effect of oil. The
amount may vary depending upon local conditions, type of
oil, marine resources, currents and other environmental
variables. Based upon evaluation of findings of studies now
underway, prohibited zones should be established and
upgraded State Water Quality Standards should specify
toxic limits on oils and toxic materials, s,
Notification
The next most impacting section of the Law deals with
the reporting of the discharge of a harmful quantity of oil
to the U.S. Coast Guard and/or EPA if inland waters.
Failure to immediately notify would subject the discharger
to a fine of not more than $10,000 or imprisonment for
not more than one year. How small of a quantity, what
type of oil, and how rapidly must the violator report are
the more significant questions which have been raised. Any
quantity of oil which violates water quality standards or
produces a sheen or emulsion or sludge must be reported.
All forms of oil including crudes, refined petroleum
products, natural oils, greases and sludges excepting
dredged spoil must be reported. The time frame within
which the report must be made is variable depending upon
circumstances. Anything other than immediate notification
would require documentation by the violation as to the
circumstance surrounding the delay. Our office has
differentiated between those materials considered to be oil
and those designated as hazardous materials. This
differentiation is based upon three considerations. These
involve whether or not a material is petroleum derived,
whether or not it is extractable by organic solvent or
whether or not the material's chemical structure is defined.
It has been argued that the purpose of notification is to
ensure immediate cleanup and that a thin sheen of oil could
be caused by a small quantity of oil which would not
warrent cleanup actions. In exploring this it has been found
that as little as 50 gallons per square mile would produce a
sheen and could be difficult to remove utilizing mechanical
means. However, if left unattended damages from such an
amount could result to boats, high value shore areas, to
waterfowl and other wildlife, and to the aquatic biota. It
has been reported that when oil from the plumage of
mallard ducks was coated on eggs , hatching success was
reduced from 80 to 21 percent. It also has been reported
that oil slicks and oil sludge tend to concentrate pesticides
which could have additional serious effects on the aquatic
biota. Each incident must be evaluated to determine what
clean up actions are required and this can only be
accomplished with immediate notification of the discharge
of a harmful quantity of oil.
Removal
The new Act clearly states that if the violator fails to
act to remove the oil he is liable to the U.S. Government
for actual cost incurred for cleanup of oil discharged in
violation of the harmful discharged regulations. Emphasis
on past spills has been to clean the beaches, clean the birds
if possible, remove as much of the floating oil as possible
and hope for the environment to absorb the greater portion
of the oil. New priorities and a new insistance on cleanup
are being developed. EPA will be providing guidelines on
procedure for determining if the discharger has properly
cleaned up the spilled oil. The word "clean" needs
clarification and a rationale will be developed so that the
Federal government and the violator can determine if all
harmful quantities of oil have been removed. Consideration
will need to be given to local environmental conditions, the
ecology and the available technology in assessing the
effectiveness of the cleanup operation. In accordance with
the Act, regulations establishing methods and procedures
for removal of discharges are being developed which will
delineate the responsibilities of the violator to ensure
proper removal of discharged oil. The problem associated
with the use of emulsifying agents has been evaluated and
the regulations will reflect the current EPA position on
their use. The regulation will cover specific items such as
proper disposal of removed oil and adequacy of cleanup
efforts.
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14
LAWS AND ENFORCEMENT
Prevention
The concern over what to report and how to cleanup
will become academic if aggressive preventive measures are
undertaken by industry. Spills caused by human error
account for up to 88 percent of the spill incidents reported
to us. Industry must develop training programs, procedural
manuals and operating regulations to reduce the number of
incidents. In addition, fail safe design concepts including
alarm systems, automatic controls and shut-off devices
must be developed. Secondary control systems such as
dikes, catchment areas and holding ponds may also be
necessary to prevent discharges from entering the
watercourses. The nation's major pipeline systems
exemplify a highly mechanized and automated system using
fail safe design concept, automatic valves, pressure sensors
and other devices to minimize opportunities for human
error.
In contrast to pipelines, vessel pilots must exercise
considerable judgment to navigate the sealanes, port
approaches and inland waterways. Storms, fog, lack of
channel markers are all contributing factors but improper
judgment is the primary cause of accidents. Installation of
echo ranging, depth sounding devices, inertial guidance
systems, and other navigation aids could drastically reduce
the number of vessel collisions and groundings. The air craft
control and aerospace guidance systems have already
developed much of the necessary technology.
Governmental agencies and private industry can take this
available knowledge and through additional research,
interpolate it for vessel navigation controls. Additionally,
secondary control systems such as double bottoms, and
gelling of petroleum during transport should be considered.
Reliance on equipment and automatic control devices
necessitates new technology to prevent equipment failure.
Failure mode and effect analysis concepts which were
highly developed in the space technology field should find
wide use in the petroleum industry. This approach requires
close coordination between regulatory agencies and the
private sector. Those responsible for design, operation, and
maintenance of transport systems should incorporate these
concepts into the early stages of development.
The implementation of prevention design concepts and
procedures is the responsibility of private industry.
However, promulgation of regulations and enforcement by
regulatory agencies is essential. Human error cannot be
totally designed out of a system but aggressive enforcement
of existing laws will no doubt encourage the employment
of alert, well trained operators.
The Water Quality Improvement Act includes
provisions for the prevention of discharges. Under Section
1 lj(l)(C) regulations are required to establish procedures,
methods and requirements for equipment to prevent
discharges of oil from vessels, onshore and offshore
facilities. These regulations have been promulgated in
general terms and permit industry and their consulting
engineer considerable leniency to upgrade and improve
present systems. It has been argued that stringent detailed
regulations restrict the advancement of new technology and
concepts. However, it can also be argued that general
regulations would encourage minimal designs which just
meet the requirement. It is the intention of EPA to monitor
very closely the advancement made in prevention and fail
safe design concepts and if sufficient progress is not made,
more stringent and detailed regulations will need to be
promulgated. Additionally, if the provisions of the Water
Quality Improvement Act are not sufficient to develop
strong aggressive prevention concepts, new legislation may
be necessary.
Enforcement
In addition to prevention concept to eliminate the
discharge of oil, an aggressive enforcement program will
also serve as a deterent to reduce the number of incidents.
The Act provides for seven significant actions which may be
taken against a violator. It should be noted that these
actions do not affect private legal actions and do not
preempt state authority to issue requirements or liability
with respect to the discharge of oil into state waters.
Federal action may be taken as follows:
a. Failure to notify of harmful discharge.
b. Deliberate discharge.
c. Cost for removal of vessel involved in marine disaster.
d. Relief against owner or operators of onshore/offshore
facility present imminent substantial threat.
e. Recovery of cleanup cost.
f. Violation of removal regulations.
g. Violation of prevention regulations.
These provisions will be enforced either through legal
actions by United States Attorney in U.S. District Courts or
through administrative hearing procedures established by
EPA and the Coast Guard. Investigation and evidence will
be collected by EPA and Coast Guard. Additional staff has
been placed in each EPA region to carry out spill response,
prevention and enforcement programs.
In addition to the enforcement provision of the Water
Quality Improvement Act chronic violators who comply
with the requirements of this Act but who also continue to
discharge oil will be prosecuted under the provisions of the
Refuse Act of 1899. If these legal actions fail to curb the
number of incidents and degradation of the environment
continues, additional legislation will be sought to
strengthen the enforcement aspects.
SUMMARY
The Water Quality Improvement Act of 1970 provides
for a strong Federal effort in cleanup, prevention, and
enforcement. It has generated new legislation at the State
level and has received the support of conservation groups.
Most of the petroleum industry is responding to the
provisions of the Act and, at present, is demonstrating a
willingness to protect the environment against the
unnecessary discharge of oil.
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LEGISLATION AND THE ACT OF 1970 15
International laws relating to oil pollution control are provisions of the Act and to cooperate fully with the States
continuously being strengthened. The U.S. has provided and industry to eliminate or, most assumedly, minimize oil
international leadership toward an objective of eliminating pollution. In the administration of the Act precaution will
oil discharges from vessels by the end of this decade. be taken to ensure that the regulations are reasonable and
based upon the most current technology and scientific
It is the intention of EPA to aggressively carry out the findings.
-------
NATIONAL CONTINGENCY PLANNING
Commander Daniel B. Charter, Jr., USCG
Maritime Pollution Control Branch
Office of Operations, Law Enforcement Division
United States Coast Guard
ABSTRACT
World production and transportation of petroleum
products have reached such magnitudes that the United
States must be prepared to cope with a massive pollution
disaster near its coast. The problems of advance planning
for cleanup of oil spills have been recognized for many
years but received little active interest before the Torrey
Canyon disaster in 1967. Following that incident the
United States began developing national and regional oil
spiR contingency plans, and the first national plan was
published in late 1968. The Water Quality Improvement
Act of 1970 spurred additional efforts, resulting in publica-
tion of a more comprehensive national plan and completion
of detailed regional plans. These plans created national and
regional response teams and established responsibilities and
procedures for responding to spills of oil and hazardous
materials in U.S. waters with appropriate cleanup and
control measures. The need for international contingency
planning has been recognized during the past year, and
some work has begun in this area.
INTRODUCTION
Today our society has reached a point of almost total
dependence upon petroleum and petroleum by-products. It
is essential every day to move literally millions of tons of
these substances through U.S. and international waters,
ports, and land areas. Without these various substances we
would be unable to maintain the standard of living that we
enjoy today. In fact, many of us would probably be unable
to exist. However, enjoyment of the benefits of these
commodities has not been without problems, some of
which include serious environmental degradation. The best
method of avoiding these environmental problems is to
ensure that these commodities are handled, transported,
and utilized in such a way as to prevent their discharge into
the environment. However, when prevention fails, a number
'The opinions or assertions contained herein are the private ones of
the writer and are not to be construed as official or reflecting the
views of the Commandant or the Coast Guard at large
of actions can be taken to minimize damages from a spill.
To be effective, these actions must be well coordinated, and
this is the function of contingency plans. This paper
outlines the history of Federal contingency planning in this
country and summarizes the status of existing plans.
History of Petroleum
Petroleum has been recognized and utilized for several
thousands of years. Probably the earliest usage involved
obnoxious seepage of oil in the Black Sea and the Caspian
Sea; this was put to beneficial use in cooking, heating,
lubrication, road-making and other construction. The
Chinese actually drilled for oil over two thousand years ago,
using percussion bits, bamboo piping, and brute force. They
had stumbled upon oil accidentally while extracting salt
from brine wells and, being far ahead of their time, made
recovery of petroleum and gas from the brine wells a major
objective.
In this country the history of oil drilling began in
Titusville, Pennsylvania, when Edwin L. Drake sank his first
well to 69 feet to initiate the Pennsylvania oil boom on
August 27, 1859. In 1865 the first successful pipeline was
constructed, and in 1871 the first rail tank car was in use.
By 1875 the first steel tanker was built.
In 1860 world production of ofl was about 1/2 million
barrels. A century later this had climbed to approximately
7 billion barrels per year, and the world currently produces
over 15 billion barrels of crude oil per year. The increase in
production and usage has naturally resulted in an increase
in transportation of ofl. Although through the years there
were numerous spills and vessel casualties that resulted in
heavy releases of oil, it was not until the 1940's that the
problem reached such magnitude that it drew serious
attention. Frequently our beaches were besmirched with oil
during World War II through the sinking of tankers in our
coastal waters. However, because of the dire circumstances
this did not generate acute public concern for cleanup. In
17
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18 LAWS AND ENFORCEMENT
the years following Worid War II, with the increased
technological development and the attendant increase in
production and consumption of oil, the problems of spills
became more acute. During the 1950's numerous studies
were conducted by various organizations and agencies on
the problems of oil spill control. In some locations
companies were formed that conducted cleanup activities
when the clamor of the property owners became too great.
Although the Coast Guard and other Federal agencies
cooperated in these efforts, the removal of spilled ofl
generally was not considered a government function, but
was left mainly to the pressures of state and local
government and the public. However, the records do
indicate that on occasion considerable pressure was exerted
by the local Coast Guard commander to insure that the
responsible party did conduct adequate cleanup.
NUM. MN&D CRUDE OIL PWOUCTION
IIU.IOB
OF MMfU
I960
INS
Figure 1: In the past two decades world crude ofl
production has increased sharply, doubling about every ten
years..
Development of Federal Plans
In my review of the Coast Guard files the first specific
official recommendation that the Federal Government play
a major role in the removal of oil was contained in an
internal directive dated 3 November 1964. That memoran-
dum proposed that "the Ofl Pollution Act of 1924 be
amended to provide, among other things, that the Secretary
may order any owner or person who has violated the Act to
remove such ofl pollution or to abate it. If there is a failure
to comply with the order the Secretary may, at his
discretion, remove such pollution or abate it." The Secre-
tary referred to was the Secretary of the Army, who at that
time was responsible for administration of the 1924 Act.
This was probably the result of a conference on ofl
pollution held on 18 March 1964. The following is from the
minutes of that conference:1 "As described by Captain
Frost USCG, the problem of reduction of occurrence in
removal of oil slicks is part of the formal activities of the
Coast Guard because that organization is duly charged, as
one of several agencies, with enforcement of the Ofl
Pollution Act. This responsibility is concomitant with the
duties related to the safety of vessels and waterfront
structures. The Coast Guard operates primarily through the
Captain of the Port, a Coast Guard officer assigned by area
to supervise Coast Guard law enforcement, safety, search-
and-rescue, and similar duties. In addition to reporting spills
and citation of violations, the duty of the Captain of the
Port includes evaluation and recommendation for proper
action on the cleanup of oil spills. In order to meet this last
obligation properly, the Captain of the Port must be
supplied with pertinent technical information of sufficient
depth to advise on questions such as those which follow:
(1) The chemical and hazardous nature of the petroleum
spilled. (2) What information should be placed in the hands
of the Captain of the Port to help him in his decision-
making? (3) Must the spill be physically or chemically
removed, or can the hazard be minimized without spill
removal? (4) What particular removal techniques are avail-
able? Which method, if several are applicable would be
best? Should these methods be chemical or physical? (5)
What is the proper equipment to be used? Where is it
available? (6) How does the size of the spill bear on its
removal? (7) How does the location of the spill bear on its
treatment and possible removal, for example, open sea
versus in-port, considering nearby buildings, port structures,
other vessels, and similar factors? (8) What will be the
influence of any chemicals introduced in removing spills?
Will the oyster, shellfish, or vertebrate fish crops be
adversely affected?"
The first mention that I have been able to locate of the
problem of on-scene coordination is in a letter from the
Commander, Second Coast Guard District, dated 18 Janu-
ary 1965, which was in response to an inquiry by the
Commandant as to the capabilities and problems of oil spill
control in the various Coast Guard districts. In his letter the
Commander, Second Coast Guard District, indicated that
when large spills or dangerous pollution occurs the Captain
of the Port having jurisdiction in the area would assume
on-scene operational control and coordinate the activities
of Coast Guard units assigned to the case. There was also
provision that the district office would coordinate activities
beyond the scope of the Captain of the Port. The letter
further indicated that all Captains of the Ports and the
rescue coordination center would keep a current list of
commercial and private facilities with cleanup capabilities
so that immediate action could be taken to clean up spills
considered hazardous or likely to damage property.
It is also interesting to note that the 1966 amendment2
to the Ofl Pollution Act of 1924 required any person
spilling ofl from a vessel into the navigable waters of the
United States to remove the ofl immediately from the water
and from the adjoining shorelines. If the spiller failed to do
so, the Secretary of the Interior was authorized to arrange
for removing the ofl, and the spiller would be liable for all
costs and expenses reasonably incurred by the Secretary in
accomplishing this removal. For various reasons this portion
of the law was largely ignored, and it appears that no action
was actually taken in the conduct of cleanup pursuant to
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NATIONAL CONTINGENCY PLANNING 19
the Act. Thus, in its effect, this law did not contribute
materially to development of federal contingency plans.
It is apparent from the study of Coast Guard records
that there was concern in the early and mid 60's over the
coordination of efforts and the cleanup of oil spills.
However, it was not until March, 1967, when the super-
tanker Toney Canyon grounded off the coast of England,
that really massive quantities of oil were released into the
water as a result of a single casualty or accident. With the
grounding of the Toney Canyon the United States and
other nations became acutely aware of the magnitude of
the problem of coordinating response efforts in cleanup of
a massive oil spill.
The immediate reaction in the United States was to
consider what we would have done had the same situation
occurred off our coast. It was apparent that no institution,
governmental or non-governmental, national or local, had
either the responsibility or capability for taking immediate
effective action.
For many years the Coast Guard had been charged with
the responsibility for maintaining search-and-rescue forces
in the maritime region to assist vessels and aircraft in
distress. The established network of Coast Guard shore
stations, vessels, aircraft and communications facilities
made it a logical choice for involvement in this problem
area, and the Coast Guard Commandant created an oil spill
study group to evaluate the problem. The group included
representatives of the former Federal Water Pollution
Control Administration, in the Department of the Interior,
and the Army Corps of Engineers, in the Department of
Defense, since both of those Federal agencies had statutory
responsibilities related to the protection of our territorial
and inland waters, generally as to the development and
enforcement of water quality standards and specifically as
to the discharge of oil and other refuse.
Another reaction to the Toney Canyon disaster was a
Presidential memorandum dated 26 May 1967 in which the
President directed the Secretaries of the Interior and
Transportation to conduct a joint study on how best to
mobilize the resources of the Federal government and the
nation to prevent disasters involving major spillage of oil,
other pollutants, and hazardous substances, and to mini-
mize the threat to health, safety, and our natural resources.
The President's directive stated that one of the required
actions was development of contingency plans to deal with
these emergencies. Shortly thereafter all Coast Guard
District Commanders were instructed to prepare con-
tingency plans for their districts and to coordinate these
plans with appropriate representatives of Federal agencies,
local authorities, and industry representatives. It was
directed that the planning should include identification of
critical areas along shorelines, navigable and coastal waters,
and the high seas within district boundaries; delineation of
areas of responsibility; an inventory of available equipment,
personnel, and specialized knowledge; and methods of
alerting appropriate officials and deploying equipment and
personnel.
Further guidance was provided in Commandant Instruc-
tion 5922.2 of 20 June 1967. An enclosure to that
instruction contained an outline of the factors to be
considered in developing the plans. Although several years
old, this guidance is still valuable in planning efforts today
and is included in appendix A to this paper.
At the same time, through contract to a private organ-
ization, a review was completed on the state of the art in
technology for response^ to oil spills. Utilizing all available
information each District^in coordination with other inter-
ested Federal agencies and local government groups, then
refined its plans. It was fully realized that for these plans
to be effective, massive research effort was necessary to
develop adequate response equipment, national legislation
was needed to clarify authority and responsibility, and
adequate funding had to be provided to insure the availa-
bility of equipment and materials.
These conclusions were reinforced by a joint report to
the President3, in February, 1968, wherein the Secretaries
of Transportation and the Interior made specific recommen-
dations for needed action at the national level.
In the early summer of 1968 a new planning initiative
was undertaken. In its review of marine concerns the
National Council on Marine Resources and Engineering
Development came to the conclusion that a unified national
planning effort was desirable. On 7 June 1968, following
the Council's recommendation, the President directed the
Secretary of the Interior to develop contingency plans for
each coastal region immediately. An interagency work
group which was established to develop these plans came to
the early conclusion that it was necessary to develop an
overall national plan to provide a framework for the re-
gional plans. Accordingly a national plan was developed,4
and in September, 1968, the President accepted the basic
national plan produced by the work group, with regional
and subregional plans to follow.
National Contingency Plan
In the meantime the Congress was developing new
legislation. The final result was the Water Quality Improve-
ment Act of 1970,5 which became law on 3 April 1970. It
included several very necessary and pertinent provisions.
These provisions, as implemented by the President, can be
simply stated as follows:
1. The discharge of harmful quantities of oil (as defined
by regulations issued by the Secretary of the Interior) from
vessels or onshore or offshore facilities into any inland,
territorial, or contiguous zone waters is prohibited.
2. The person in charge of the discharge source must
immediately report the discharge to the Coast Guard or
other specified officials.
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20 LAWS AND ENFORCEMENT
3. The owner or operator of the discharge source must
immediately remove the discharged oil or must reimburse
the Federal government for its costs should Federal action
be necessary.
4. A revolving fund of $35 million for immediate oE
removal needs was authorized.
5. A national contingency plan for Federal action,
containing specific provisions, was required.
In connection with the last item the President, using the
previous planning as a foundation and acting through the
Chairman of the Council on Environmental Quality, pub-
lished the National Oil and Hazardous Materials Pollution
Contingency Plan on 2 June 1970.6 This Plan provides for a
pattern of coordinated and integrated responses to pollut-
ing spills by departments and agencies of the Federal
government. It establishes a national response team and
provides guidelines for the establishment for regional
contingency plans and response teams. This Plan also
promotes the coordination and direction of Federal, state,
and local response systems and encourages the'development
of local government and private capabilities to handle such
polluting spills.
A primary objective of the National Plan is to encourage
the person responsible for a polluting spill to clean it up. If
this person is taking adequate action to remove the
pollutant or mitigate its effects, the principal thrust of
Federal activities is to monitor the situation and to provide
advice as may be necessary. Further Federal response
actions are required only if the person responsible for a
pollution incident does not act promptly to contain, clean
up, and dispose of the pollutant.
This plan is effective for all United States navigable
waters including inland rivers, the Great Lakes, coastal
territorial waters, and the contiguous zone and high seas
beyond this zone where there exists a threat to U.S. waters,
shoreface, or shelf-bottom.
Although many Federal agencies may at one time or
another become involved in a spill response situation, only
a few Federal agencies regularly become involved in spill
cleanup operations. These agencies have been designated
the "primary" agencies by the National Contingency Plan.
Each of them has responsibilities established by statute,
Executive Order, or Presidential Directive which may bear
on the Federal response to a pollution incident. The Plan
promotes the expeditious and harmonious discharge of
these responsibilities through recognition of the specific
capabilities of each agency. State and local governments,
industry groups, the academic community, and others are
also encouraged to commit resources for response to a spill.
Of special relevance here is the organization of a standby
scientific response capability.
The Plan established the National Interagency Commit-
tee for Control of Pollution by Oil and Hazardous Materials
STANDARD REGIONS FOR FEDERAL ADMINISTRATION
- C.G Are* of Responsibly
Figure 2: Under the National Contingency Plan regional
contingency plans have been developed for the ten standard
regions for Federal administration. The Coast Guard is
responsible for planning and providing on-scene com-
manders in coastal areas (dotted lines), and the Environ-
mental Protection Agency performs these functions in
inland areas.
(NIC), which is the principal instrumentality for national
plans and policies concerning Federal preparedness for
response to pollution incidents. This committee, which is
composed of representatives of the primary agencies,
develops procedures to promote the coordinated response
of government and private agencies to polluting spills and
makes recommendations concerning the interpretation,
application, and revision of the National Plan. It reviews
reports on the handling of major or unusual pollution
incidents for the purpose of analyzing such incidents and
recommending needed improvements in the contingency
plans.
Under the National Contingency Plan coordination and
direction of Federal pollution control activities at the scene
of a spill or potential spill is accomplished through an
on-scene commander (OSC). The OSC is the single execu-
tive agent predesignated by the regional plan to coordinate
and direct these activities in his area of the region. In the
event of a spill of oil or other hazardous substance, the first
Federal official on the site from any of the primary
agencies assumes the duty of coordinating activities under
the Plan until the predesignated OSC becomes available to
take charge. The OSC determines pertinent facts about a
spill, such as the nature, amount, and location of material
spilled, its probable direction and time of travel, and the
resources and installations which may be affected and the
priorities for protecting them. Thje OSC then initiates and
directs Phase II, Phase III. and Phase IV response operations
(described below), and he provides support and documenta-
tion for Phase V activities.
The U.S. Coast Guard is assigned the responsibility to
furnish or provide for OSCs for the high seas, coastal and
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NATIONAL CONTINGENCY PLANNING 21
OCMI
OSWEGO
Figure 3: In coastal areas, includingJhe Great Lakes, Coast
Guard Captains of the Ports (COTPs), Officers in Charge of
Marine Inspection (OCMs), and other Coast Guard units
are the predesignated on-scene commanders for response to
pollution incidents. Their geographic areas of responsibility
are described in the regional plans.
contiguous zone waters, coastal and Great Lakes ports and
harbors, and such other places as may be agreed upon
between the Environmental Protection Agency (EPA) and
the Coast Guard. EPA furnishes or provides for OSCs in
other areas. An exception to this rule is made whenever a
spill is caused by a U.S. public vessel or by a federally
controlled facility; in that case the responsible agency
provides the OSC and takes the initial response actions.
The Plan also established a National Response Team
(NRT), which, like the NIC, consists of representatives of
the primary agencies. It functions as an emergency response
advisory team and is activated in the event of a pollution
incident involving oil or any other hazardous material
which: (a) exceeds the response capability of the region in
which.it occurs; (b) affects more than one region; or (c)
involves national security or presents a major hazard to
substantial numbers of persons or nationally significant
amounts of property. During a pollution incident the NRT
meets at the National Response Center and reviews reports
coming from the OSC, requesting such additional informa-
tion as may be needed. The NRT coordinates the actions of
the various regions or districts in supplying needed assis-
tance to the OSC. It may recommend courses of action
through the Regional Response Team (see "Regional
Contingency Plans" below) for consideration by the OSC
but has no operational control of the OSC.
The National Response Center (NRC) is the Washington,
D.C., headquarters for activities relative to pollution inci-
dents. It is accommodated in Coast Guard Headquarters
and provides communications, information storage, person-
nel, and other necessary facilities to promote the smooth
functioning of this activity.
For the purposes of contingency planning the Federal
response to a polluting spill is divided into five phases, two
or more of which may take place simultaneously. They are:
Phase I: Discovery and Notification
Discovery of a spill may be through vessel patrols,
aircraft searches, or similar deliberate procedures, or
through incidental observations of government agencies or
the general public. Such reports may come initially from
fishing or pleasure boats, police departments, telephone
operators, port authorities, news media, airline pilots, etc.
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22 LAWS AND ENFORCEMENT
Regional plans provide for spill reports to be channeled into
the Regional Response Center as promptly as possible.
Phase II: Containment and Countermeasures
These are defensive actions to be initiated as soon as
possible after discovery and notification of a pollution
incident. After the OSC determines that further Federal
response actions are needed, he may direct appropriate
actions such as source control, public health protection,
ship salvage, placement of physical barriers to halt or slow
the spread of the pollutant, emplacement or activatipn of
booms or barreirs to protect specific installations or areas,
and deployment of materials to mitigate the effects of the
pollutant on water-related resources.
Phase III: Cleanup and Disposal
This includes those actions taken to remove the pollu-
tant from the water and on-shore areas, such as the
collection of oil through the use of sorbers, skimmers, or
other collection devices, the removal of beach sand, and
safe, nonpolluting disposal of pollutants which are recov-
ered in the cleanup process.
Phase IV: Restoration
This includes those actions taken to restore the environ-
ment to its pre-spill condition, such as replacement of
contaminated beach sand.
Phase V: Recovery of Damages and Enforcement
This includes recovery of damages to government prop-
erty ; however, third party damage is not considered in this
phase. Recovery of the costs of cleanup is also included, as
are other enforcement activities. The collection of scientific
and technical information of value for research and
development activities and for the enhancement of our
understanding of the environment may also be considered
in this phase.
The nucleus of a national-level strike force, consisting of
personnel trained, prepared, and available to provide the
necessary services to cany out this plan, has been estab-
lished by the Coast Guard. This force, presently located on
the east coast, is being augmented and will soon be sited at
various locations throughout the country. Assistance from
the national-level strike force may be requested through the
appropriate Coast Guard District Commander, Area Com-
mander, or the Commandant. The strike force will direct
the operation of any government-owned specialized pollu-
tion cleanup equipment and will function under the OSC.
At the time of this writing (March, 1971) action has
been initiated to amend the National Plan. The Comman-
dant of the Coast Guard has recommended amendments to
the plan to reflect the recent Federal reorganization and to
clarify or change portions of the plan that operational
experience has shown need amendment. No major changes
in the thrust or procedures in the plan are known to be
required, and the plan will continue to serve adequately in
its present form until the amendment is made. It is
understood that plans have been made to develop the
amendment on a high priority basis.
Regional Contingency Plans
As previously indicated, the President in June, 1968,
indicated that contingency plans were to be developed for
each coastal region. Thus it is clear that it was recognized
initially that the functional plans would have to be
developed at the regional level. The National Contingency
Plan provides the overall policy and general guidelines, for
these regional plans.
Although the original efforts to develop regional plans
were made by the Coast Guard, the President in his memo
of 7 June 1968 assigned this responsibility to the Depart-
ment of the Interior. Coast Guard units were then directed
to work with the Federal Water Pollution Control Admini-
stration (now the Water Quality Office of the Environ-
mental Protection Agency) in development of these plans.
Much of the previous work accomplished by the Coast
Guard was used as the basis for this development.
However, before these plans being developed by the
Department of the Interipr were actually completed and
submitted to the National Interagency Committee for
review and approval, responsibilities were again shifted.
Since the agency coordinating on-scene operations and
providing the bulk of the response resources was different
from the agency responsible for the planning activity, some
problems were naturally encountered. Meetings between
representatives of the Departments of Transportation and
the Interior in February and March, 1970, resulted in the
present agreement on planning and response responsibili-
ties.
The Coast Guard is responsible for contingency planning
in the coastal areas, and the Environmental Protection
Agency in inland areas. Coastal, areas generally encompass
waters subject to tidal activity or waters capable of
supporting deep-draft vessels. The agency responsible for
planning is also responsible for furnishing or providing for
on-scene commanders and acts as chairman of the regional
response team. The standard regions developed for purposes
of general Federal administration are used as the regions for
planning purposes. The coastal and inland regional plans
generally use standard format and procedures throughout
the country. The coastal plans are all based on a model plan
distributed in a Commandant Instruction in April, 1970.
Most of the inland plans were also patterned after this
model plan. Coastal regional plans are subdivided along
state boundaries. In many cases states are further sub-
divided into zones.
The coastal and inland regional plans were submitted to
the Council on Environmental Quality in June, 1970, as an
annex to the National Contingency Plan. These plans were
developed simultaneously with the National Plan and
before the full impact of the Water Quality Improvement
Act of 1970 could be assessed. Therefore, Coast Guard
-------
NATIONAL CONTINGENCY PLANNING 23
district commanders were directed to revise the plans by 1
December 1970. While this revision was in progress, most of
the pertinent responsibilities of the Department of the
Interior were transferred to the Administrator, Environ-
mental Protection Agency, by Federal Reorganization Plan
No. 3 of 1970. The December, 1970, editions of the coastal
regional plans were therefore obsolete before they were
approved. At the time of this writing (March, 1971), efforts
to develop further amendments have not been initiated but
will be as soon as the amendment to the National Plan is
developed.
The regional plans closely parallel the National Plan but
are adapted to the special problems of the geographic area
concerned and provide a considerable amount of detailed
information about that area. Their primary purpose is to
provide a Federal response capability at the regional level.
In each region there is a Regional Response Team (RRT)
consisting of regional representatives of the primary agen-
cies. Since the agencies' regional boundaries do not gener-
ally coincide with those of the newly created standard
Federal administrative regions, a single agency may be
represented on the RRT by any of several individuals,
depending on the location of the pollution incident being
considered. Like the NRT the RRT acts as an emergency
response advisory team, but on a regional level. It also
performs review and advisory functions relative to the
regional plan similar to those which the NIC performs
relative to the National Plan. The RRT controls the extent
and duration of Federal involvement in the response to a
pollution incident and decides when a shift in on-scene
coordination from the predesignated OSC to another
agency may be appropriate. There is also a Regional
Response Center in each region which performs functions
parallel to those of the National Response Center.
The regional plans also provide for local pollution
control strike forces which, like the national strike force,
are trained, prepared, and available to carry out the plans.
During an incident these teams will be able to assist the
national strike force or merge with other local forces, and
they will be capable of full independent response to all
minor spill situations within their areas. In addition, at
major ports (to be designated by the President) "emergency
port task forces" will be established'to complement the
national- and local-level strike forces. Detailed oil pollu-
tion prevention and removal plans will be developed for
these ports, and adequate oil pollution control equipment
and materials will be provided.
International Contingency Plans
The Torrey Canyon incident was of such magnitude that
it affected more than one country, thus indicating the
necessity for international coordination in pollution inci-
dents. One of the earliest efforts to develop international
pollution contingency plans was among the nations border-
ing on the North Sea. In the United States the first effort to
develop an international plan began in 1970 under the
auspices of the United States-Canada International Joint
Required Procedure for Rapid Alerting
notification required
notification required only if
spill might affect both countries
Minor Spills
Report from any of various sour
port from any of various sources
OSC
Deputy OSC (other country)
Moderate and Major Spills and Pollution Incidents
Report from any of various sources
OSC
Deputy OSC(other country)
OSC's country's
•enters of JRT
Deputy OSC's country's
neuters of JRT
Figure 4: This is an excerpt from a draft proposal for a
joint U.S.-Canadian Great Lakes pollution contingency
plan, showing proposed procedures for notifying appro-
priate officials of polluting spills. (OSC=On-Scene Com-
mander; JRT=Joint Response Team)
Commission (IJC). In response to an April, 1970, IJC
report7 recommending that the United States and Canada
develop a coordinated international contingency plan for
dealing with spills of oil and other hazardous materials in
the boundary waters of the Great Lakes system, a joint
U.S.-Canadian working group began preparation of such a
plan toward the end of last year. This project was given
additional impetus by an IJC report on Great Lakes
pollution8 dated December, 1970, which recommended,
among other things, that "the Governments of Canada and
the United States enter into agreement to develop coordi-
nated international contingency plans so that both coun-
tries may quickly and effectively respond to major acci-
dental spills of oils, hazardous or radioactive materials in
the boundary waters of the Great Lakes system."
As of March, 1971, a joint U.S.-Canadian pollution
contingency plan had been drafted and was being reviewed
by the joint working group. This draft plan would provide
for a pattern of coordinated and integrated responses to
-------
24 LAWS AND ENFORCEMENT
pollution incidents on the Great Lakes by responsible
federal, state, and local agencies in the U.S. and federal,
provincial, and local agencies in Canada. It was intended to
supplement the national, provincial, and regional plans of
the two nations and therefore addressed itself primarily to
international matters not covered by these plans. It would
cover the waters of the Great Lakes (except Lake Michi-
gan), their interconnecting waterways and major tributaries,
and the international section of the St. Lawrence River for
any polluting spill that affects, or threatens to affect, the
waters of both nations. As drafted, the joint plan would
establish a Joint Response Team comparable to the
Regional Response Teams in the United States. For any
spill requiring an international response an OSC from one
country and a deputy OSC from the other country would
be charged with on-scene coordination. A reporting system
would insure that such spills would be reported promptly
to the concerned government officials on both sides of the
border. Pre-planned procedures would be available for
coordinating rapid response measures, including the mobil-
ization of cleanup and control resources. A command-
control structure would be available to insure that emer-
gency actions could proceed without delay. Coordination
would also be provided in the areas of funding, surveillance,
and public information.
The need for international contingency plans received
further recognition at the conference on Pollution of the
Sea by Oil Spills which was conducted by NATO's
Committee on the Challenges of Modem Society in
November, 1970. The conference approved a resolution
calling on NATO nations to develop national oil spill
contingency plans, to cooperate in detecting and reporting
oil spills, to assist each other in minimizing the damage
caused by such spills, and to cooperate "to insure the
greater possible consistency and mutual assistance in the
preparation of their national contingency plans," among
other things. Specifically, the conference recommended
that the member nations establish centers along their coasts
to receive reports of oil spills and relay these reports to any
other nation that might be affected. It recommended that
member nations require their flag vessels and aircraft to
report oil spills to these centers. The concept of regions of
international cooperation based on geographic patterns of
petroleum commerce was also advocated in connection
with contingency planning.
It is evident that the area of international contingency
planning is currently an active one, and it will probably
undergo considerable development within the next few
years.
CONCLUSION
The plans discussed in this paper are those developed by
the Federal Government. In addition to the Federal plans,
many state and local governments and industries have
developed contingency plans. These non-federal plans
should, if possible, be developed in such fashion as to be
responsive to the Federal planning effort. This will help
avoid duplication and confusion and permit a compatible
coordinated response when required.
The planning effort never ceases. As further experience
is gained, the plans are re-evaluated, and changes are made
to improve their effectiveness. Also, agency responsibilities
will shift, and other changes will require amendments to the
plans. However, even with the best possible plans we would
still be unable to respond satisfactorily to spill situations at
present. Although the plans permit coordinated efforts and
clarify responsibilities, the response, no matter how
smoothly managed, will still be limited by the capability of
existing technology. However, as better equipment is
developed, the existing machinery for coordination of spill
control efforts ^will facilitate prompt deployment of the
equipment. We still have a long way to go, but we have
come a long way since the Torrey Canyon.
BIBLIOGRAPHY
1. "Oil Slick Pollution," minutes of Conference on Oil
Slick Pollution of Harbors and Associated Waters, 18 March
1964, U.S. Coast Guard.
2. Public Law 89-753, Section 211.
3. "Oil Pollution, A Report to the President," Department
of the Interior and the Department of Transportation,
February 1968.
4. "National Multi-Agency Oil and Hazardous Materials
Pollution Contingency Plan," September 1968.
5. Public Law 91-224.
6. "National Oil and Hazardous Materials Pollution Con-
tingency Plan," Council on Environmental Quality; Federal
Register, Vol. 35, pp.8508-8514, 2 June 1970.
7. "Special Report on Potential Oil Pollution, Eutrophica-
tion and Pollution from Watercraft," International Joint
Commission (United States-Canada), April 1970.
8. "Pollutuion of Lake Erie, Lake Ontario, and the
International Section of the St Lawrence Seaway," Inter-
national Joint Commission (United States-Canada), Decem-
ber 1970.
APPENDIX A
Guidelines for Combating Oil Pollution
Pre-emergency Oil Spill Planning
Review Disaster Control Plans and related data to include
plans to cope with a major oil spill occurring in:
(a) Port areas
(b) Harbor approaches or channel
(c) Navigable rivers, estuaries, and waterways
-------
NATIONAL CONTINGENCY PLANNING 25
(d) Coastal waters
(e) International waters posing a threat to the coastal
area
Assessment of Threat Caused by a Major Spill:
(a) Effect of spill on:
(1) Navigation
(2) Port safety
(3) Marine life
(4) Wildlife
(5) Municipal water supply
(6) Privately owned property
(b) Determination of maximum credible potential oil
spill.
(1) Quantity of spill
(2) Location of spill
(3) Survey of tanker operations in the assigned
area (operational areas)
(4) Properties of probable pollutants
(5) Areas affected by the spill
(a) Staying power of the spill
(b) Weather effect
(c) Effect of current, tides, or wind
Warning System
(a) A system for identifying sources of pollutants
(b) Establishment of a pollution reporting system or
network through:
(1) Voluntary participation of local Federal,
state and local agencies
(2) Active patrols, air and surface in the event
of a major spill
(3) Normal operations
(4) Surveillance, position, dead-reckoning of the
slick, plotting
(c) Establishment of a notification system to affect
local Federal, state and local authorities, industry
and the public through:
(1) Port warning system
On-Scene Operation
1. General
(a) Procedures for establishing a Security Zone
(b) Procedures for controlling entry of persons and
vessels
(c) An inventory of Coast Guard resources
(d) An inventory of other local resources of equipment,
technical knowledge and expertise
(e) Safety instructions to personnel operating in the
spill area
(f) Total effects of containment, abatement or clean-
up procedures and methods
2. Abatement procedures - containment, cleanup
(a) On the vessel
(b) Surrounding waters
(c) Ports, harbors, channels, or beaches
3. Containment
(a) Prior to majority container release
(1) Transfer to another container
(a) vessel (b) barge (c) floatable bags
(2) Vessel salvage
(3) Destroy—sea water temp, swell size, location
and pollutant property will dictate degree of
success
(b) After container release
(1) Envelope containment-spill boom, pneu-
matic barrier
(2) Chemical containment
(a) surface coagulants
(b) bottom coagulants—silicone base
(3) Dispersers—detergents, sodium or potassium
soaps
(4) Absorbent materials-sawdust, cement, straw,
chalk, lime, etc.
(5) Mutants-chemical emulsifier
(6) Destroy
4. Cleanup
(a) Water
(1) Mechanical
(a) skimmer (b) centrifuge (c) vacuum
(2) Chemical
(a) Coagulants
(1) Surface
(2) Bottom
(b) Detergents
(c) Dilutants
(d) Absorbents
(e) Destroy
(b) Beach
(1) Mechanical
(a) sand removal (b) burial of polluted sand
(2) Chemical
(a) Coagulants
(1) Surface
(b) Detergents
(c) Dispersers
(d) Destroy
Specific Comments:
1. Physical properties of many emulsifiers, solvents or
detergents are toxic to marine flora and fauna, therefore,
these agents should be used only with concurrence of
wildlife authorities.
2. Emulsifiers, solvents or detergents will i'orm a thin
layer on top of the parent oil slick, and will be more
affected by the wind, than the current.
3. Precipitating the oil to the bottom with presently
known products will only result in a short-term removal.
The oil will eventually rise to the surface. Sunken oil will
kill bottom wildlife.
4. Oil mechanically removed from the beaches and
buried in the ground may contaminate the water table. This
method of disposal should be cleared with local health
authorities.
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26 LAWS AND ENFORCEMENT
5. Burning of heavier grades of oil in the open sea is
generally unsuccessful because of the inability to maintain
burning temperatures.
6. Burning of chemicals may be extremely hazardous.
All chemical properties should be checked with a qualified
marine chemist or chemical engineer.
7. Mechanical booms are generally effective only in
sheltered waters; wind and wave action in the open sea will
either bridge or break the floating booms.
8. Firing or bombing of the vessel will probably
aggravate the pollution by further releasing oil remaining on
board.
9. Immediate action is mandatory to prevent or mini-
mize the spread of oil—hence the importance of oil spill
pre-planning cannot be overemphasized.
10. Amounts of emulsifiers, solvents or detergents may
be effective in proportion to amount of escaped oil as low
as 1:6-9. Ideal mixture, however, is 50-50.
11. Detergent mixture sprayed on the oil in a fine spray
in the open sea is reported to be non-toxic to marine life.
To be effective the mixture must be applied to the oil and
be thoroughly mixed within 30 minutes of application.
Mixing can be accomplished by the use of a powerful jet of
water or motorboat or ship's screw. Wind and sea action are
significant factors in dissipating the oil-detergent-sea water
emulsion. Specific actions, however, will depend to a large
degree on the chemical properties of the detergent.
-------
INTERNATIONAL ACTIVITY REGARDING
SHIPBOARD OIL POLLUTION CONTROL
CaptainR. I. Price*
United States Coast Guard
INTRODUCTION
"... the coasts and coastal waters of many countries are
seriously affected by oil pollution, the results of which
include great damage to coasts and beaches and consequent
hindrance to healthful recreation and interference with the
tourist industry, the death and destruction of birds and
other wild life, and probable adverse effects on fish and the
marine organisms on which they feed. There is widespread
public concern in many countries about the extent and
growth of this problem.
The pollution is caused by persistent oils, that is to say
crude oil, fuel oil, heavy diesel oil and lubricating oil. While
there is no conclusive evidence that these oils persist
indefinitely on the surface of the sea, they remain for very
long periods of time and are capable of being carried very
considerable distances by currents, wind and surface drifts
and of building up into deposits on the sea-shore. Very
large quantities of persistent oils are regularly discharged
into the sea by tankers as a result of the washing of their
tanks and the disposal of their oily ballast water. Dry cargo
ships which habitually use their fuel tanks for ballast water
also discharge oily ballast water into the sea and this also
gives rise to pollution. It is practicable for tankers to adopt
a procedure whereby their oily residues can be retained on
board and discharged into reception facilities at oil loading
ports or repair ports. Pollution resulting from the discharge
of ballast water from dry cargo ships can be reduced or
prevented by the installation of efficient oily-water separa-
tors or other means, such as the provision in ports of
adequate reception facilities for oil residues.
*Any opinions expressed in this paper are those of the author and
not necessarily those of the Coast Guard or the Department of
Transportation.
The only entirely effective method known of preventing
oil pollution is the complete avoidance of the discharge of
persistent oils into the sea and, as stated above, measures
are possible which would enable this to be substantially"
achieved.
While ... a date cannot be fixed at the present time by
which there should be complete avoidance of the discharge
of persistent oils into the sea,... complete avoidance of
the discharge of these persistent oils should, with certain
necessary exceptions, be observed from the earliest practi-
cable date and strongly urge all governments and other
bodies concerned to use their best endeavors to create the
conditions upon which the observance of such a prohibition
necessarily depends by securing the provision of adequate
facilities in their main ports and the necessary arrangements
in ships."
Sound familiar? You've heard or read that a hundred
times lately? Interesting!—That is a major portion of the
text of Resolution No. I of the 1954 International
Conference on Pollution of the Sea by Oil, titled the
"Complete Avoidance as Soon as Practicable of Discharge
of Persistent Oils Into the Sea."
First Efforts
Efforts to control oil pollution internationally go back a
very long way. Following World War I the U.S. Congress,
disturbed by damage caused by oil in the sea in 1922,
proposed an international conference. Studies which were
carried out then within the government led in 1924 to the
National Oil Pollution Act.
27
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28 LAWS AND ENFORCEMENT
In 1926, the United States convened an Intergovernmen-
tal Conference of Maritime Nations in Washington.* Al-
though the representatives of 13 governments endorse^ the
Act of that Conference, the Convention drafted then was
never adopted. However, cooperative agreement among
some ship owners to refrain from discharging oily water
within 50 miles of any coast did emerge from an Interna-
tional Shipping Conference made up of private ship owner
organizations held in 1926.
In 1936, the League of Nations proposed a Conference
to consider a Convention similar to the one drawn in
Washington ten years before but the Conference never took
place. The subject was reopened in 1949 under the United
Nations which accumulated the views of governments and
in 1953 the Economic and Social Council of the U.N.
endeavored to establish a group of experts to consider the
matter. This effort was postponed when the United
Kingdom government proposed a diplomatic conference in
London in 1954.
Thirty-two nations participated and produced the Con-
vention of 1954 along lines similar to the product of the
1926 Washington Conference.
The 1954 Convention:
The 1954 Convention for Prevention of Pollution of the
Sea by Oil was a rather broadly drawn effort which set up
zones in which it was prohibited to discharge oil or an
objectionable oily mixture (defined as having 100 parts or
more of oil per million of the mixture) and which instituted
an oil record book to be kept by each ship on the use and
handling of oil on board.
The Convention was apparently viewed as a first cut by
the conferees because Resolution I went on to propose that
a future Conference "to review the matter in light of
experience of tj»e working of the arrangements recom-
mended by this Conference should be held within three
years." However, it was eight years before there was to be
another meeting.
The 1954 Convention had a number of weaknesses such
as failure to specify uniform penalties and to cope with the
difficulty of prosecuting the many vessels of certain flags
which seldom return home. It exempted sludge and residues
provided these were discharged "as far from land as is
practicable." Also exempted was oily discharge from ships
other than tankers when proceeding to a port not having
reception facilities. On the other hand, the Convention also
had a number of significant regulations, some of which
were rather onerous. One placed a direct obligation on
*. . . the representatives of some governments considered that
after a specified period of notice the discharge of oily mixtures
constituting a nuisance should be prohibited everywhere, and that
in the meantime a system of areas should be established within
which no such discharge should be allowed. The other opinion was
to the effect that a sufficient case had not been made out for
prohibition everywhere fw>d that the establishment of an effective
system of areas would provide a complete or almost complete cure
for the evils complained of." (From the Report of the 1926 Wash-
ington Conference.)
governments to furnish adequate oil disposal facilities in
their ports. The United States with its extensive coast line
would have been under considerable burden to satisfy this
article within the stipulated three years after the Conven-
tion came into force. The Convention also required that
within 12 months after coming in force all ships be fitted to
assure that bilges could not be discharged into the sea
without the mixture being passed through an oily water
separator, notwithstanding findings of a national committee
on the inadequacies of separation equipment.
In consequence of these and other difficulties the United
States did not sign the Convention until 1961, in time to
join the following year in a new Conference convened to
amend the 1954 document.
The 1962 Conference:
The consequence of the 1962 amending Conference was
a strengthening of the Convention extending prohibited
zones considerably further to sea. The oil record book was
set out in greater detail. The impact of the 1954 document
was also softened in certain respects such as allowing oil in
bilges to be pumped overboard as long as the discharge did
not contravene the Convention, where the 1954 version
required an oily water separator. The 1962 Conference also
removed the obligation of Governments to furnish in each
main port oily water reception facilities and instead charged
them to promote provision of such facilities. Combined
with retention of the exemption for ships proceeding to a
port not having reception facilities, some of the "clout"
seems to have been lost. However, this relaxation was not
to be allowed a new ship of 20,000 tons gross tonnage,
which at that point in time was evidently regarded as the
outer limit. (This corresponds approximately to a tanker of
650' in length. Today supertankers exceed 1,000 feet in
length.) Any future such vessel was precluded from
discharging oil or oily mixture except in exceptional
circumstances and then only outside the prohibited zones
with a full report of the circumstances of each such case
being required.
Reception Facilities:
In preparation for the 1962 Conference the United
States National Committee conducted a survey of the
extent to which reception facilities for oily wastes were
available in the United States. The table at Annex I is
excerpted from the Proceedings of the Merchant Marine
Council of the U.S. Coast Guard, issue of May, 1961. A
similar survey is currently under way and it will be
interesting to leam what has happened in the past 10 years
toward increasing such facilities in this country.
Safety and Pollution:
Pollution by ships is an offshoot of safety needs. This is
not only the case with accidents but with "routine"
operations. Ships must regularly dispose of oily bilge to
preserve stability and to eliminate the accumulation of a
fire hazard. Conventional vessels at various times take on
ballast into emptied fuel tanks to preserve stability. Tankers
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INTERNATIONAL ACTIVITY ... 29
take on ballast water into cargo tanks to adequately
immerse propeller and rudder for controllability as well as
to immerse the hull to reduce structural stress in heavy seas.
The problem is getting rid of the contaminated water.
The delay and inconvenience caused by insufficient disposal
facilities in ports along with heavy penalties for harbor
pollution have generally been cause for evasion of the
carriage of required ballast in oil tanks. This was most
clearly demonstrated in 1956 when, having experienced a
collision off Nantucket inbound to New York, the crack
Italian liner ANDREA DORIA took a sharp initial list
which led to progressive flooding and the eventual loss of
the ship. According to a Coast Guard investigation con-
ducted for the House Merchant Marine Fisheries Committee
the vessel ought to have survived the damage. While her loss
could be directly attributed to failure to carry required
ballast water in the wing fuel tanks when empty, the
motivation for non-compliance was doubtless the wish to
avoid the in-port problem of disposing of oily water. This
problem of ballasting of passenger ships was studied
extensively by a U.S. Construction Committee preparing
the national position for the 1960 Safety of Life at Sea
Conference, convened as a consequence of the ANDREA
DORIA sinking. The Committee concluded that a ship
obliged to rely on ofly ballast operation had a built-in
safety hazard as a consequence of the distasteful aspects
which prompt evasion by the master and engineer. The
US., therefore, recommended to the Conference that
reliance on oily ballast operation by passenger ships should
be minimized and that future ships should be capable of
operating over as much of the intended route as practicable
without resorting to oily ballast for maintenance of
required stability.
What emerged in the 1960 Safety of Life at Sea
Convention is less specific, i.e., Regulation 8, Chapter II -
"When ballasting with water is necessary, the water
ballast should not in general be carried in tanks
intended for oil fuel. In ships in which it is not
practicable to avoid putting water in oil fuel tanks,
ofly water separator equipment to the satisfaction of
the Administration shall be fitted or other alternative
means acceptable to the Administration shall be
provided for disposing of the oily water ballast."
IMCO:
An important event in 1959 was the coming into force
of the Intergovernmental Maritime Consultative Organiza-
tion (IMCO), a specialized agency of the United Nations for
maritime matters. The IMCO Convention had been drawn
up in 1948 but it took 10 years before there was a
sufficient number of signatories to bring the Organization
to life.
The creation of IMCO provided a forum for continuing
exchange among the world's maritime safety administra-
tions. The Organization promptly became the custodian of
important international conventions regarding the sea and
the means by which those international treaties could be
kept up-to-date on a regular basis. Among the first activities
of IMCO were the conducting of conferences in 1960 on
Safety of Life at Sea (SOLAS) and in 1962 on amending
the Convention for Prevention of Pollution of the Sea by
Oil as mentioned earlier.
There are a number of international organizations taking
an interest in controlling marine pollution but the actions
of IMCO have the most direct impact. From this point most
of the discussion will pertain to work being done in this
Organization. It therefore seems appropriate to provide
some insight as to the mandate, structure and procedures of
this body.
The Assembly is the central body of the Organization
and is composed of the 72 member states. Regular
Assembly meetings are held every two years but the body
may hold extraordinary sessions when there is an urgent
need. The Council is the administrative organ comprised of
18 states which generally meet twice a year. Subordinate
to the Council are the Legal Committee, Facilitation
Committee, and as the primary action element, the Mari-
time Safety Committee (MSC). The MSC is made up of 16
member states and beneath this body there are at the
present time 11 working Subcommittees handling technical
matters according to function or discipline. Annex II is a
graphic depiction of the IMCO structure. The work in the
IMCO technical program is not conducted by its small
established Secretariat but by the representatives of the
member nations. This has a steadying effect because
proponent and advocate are obliged to personally under-
take the basic research to document and support their
porposals.
The Organization holds approximately 24 meetings each
calendar year. These meetings range from the subcommittee
level in which'purely technical considerations are appropri-
ate to those of the Assembly which as the governing body
of IMCO votes on proposals from the lower bodies after all
phases of the proposals have been considered.
The finished product of IMCO is the IMCO resolution. It
has been examined carefully from all angles and been
approved by vote of the Assembly on which all member
nations have equal representation.
At this point it is essential to appreciate the effect of an
IMCO decision upon the U.S. industry and the public in
general. To begin with, it should be clearly understood that
IMCO decisions are NOT automatically binding upon the
various governments. IMCO "recommends" the decision to
the governments for adoption. It is then up to the
individual governments to decide if they want to adopt
IMCO's recommended action. In this country, if the IMCO
recommendation relates to an International Convention or
an amendment to an International Convention, it would
not be binding upon industry or the public until:
a. Ratified by the United States.
b. Implementing legislation is passed (if needed); and
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30 LAWS AND ENFORCEMENT
c. Regulations (if needed) are promulgated in the
normal manner (in the case of Coast Guard Regula-
tions, this includes a public hearing).
If the IMCO recommendations did not relate to an
International Convention it would not be binding upon
industry or the public until:
(1) The Department of State refers the matter to the
appropriate agency (in the case of a technical
maritime safety matter this would probably be the
Coast Guard);
(2) Implementing legislation is passed (if needed); and
(3) Regulations (if needed) are promulgated in the
normal manner (in the case of Coast Guard Regula-
tions, this includes holding a public hearing).
Pre-TORREY CANYON:
Up to the point of the TORREY CANYON incident in
the Spring of 1967, IMCO had undertaken studies on a
wide range of subjects through its Technical Subcommittee
Organization, based primarily upon the recommendations
of the 1960 Safety of Life at Sea Conference including the
Rules for the Prevention of Collisions at Sea- and of the
1962 Conference for the Prevention of Oil Pollution at Sea.
Agreement was reached by the Organization on the
following items having a bearing on prevention of oil
pollution without the stimulus of that unfortunate inci-
dent:
-Standardized day and night markings for oceano-
graphic craft and structures;
—Recommended maintenance of certain navigation
lights on islets in the Red Sea to enhance safety of
tankers and other vessels plying those waters;
-Endorsed the separation of traffic in the Strait of
Dover along with the improvement of the pertinent
navigational aids;
-Developed jointly with the International Labor Organi-
zation a guidance document on the education and
training of masters, officers and seamen;
—Revised the International Code of Signals;
-Agreed upon lights and shapes for dracones under tow;
-Promoted the extension of weather reporting services;
-Agreed to encourage provision of spaces onboard ship
for the separation, clarification or purification and
carriage of slop oil by allowing such spaces to be
deducted from gross tonnage in determining net
tonnage.
-Recommended the performance of navigation lights in
large vessels with high superstructures aft.
—In 1966 conducted a major international conference to
update the International Load Line Convention of
1930, including for the first time requirements for the
internal compartmentation of cargo ships.
Post-TORREY CANYON:
The pace quickened with the grounding of the TORREY
CANYON leading the United Kingdom Government to call
for a special meeting of the IMCO Council, which in May
1967 added to the Organization's already formidable work
program new dimensions and priorities regarding pollution
control. Following an outline prepared by the British,
measures discussed were broken down as follows:
(a) Preventive Measures:
Sealanes
Shore Guidance
Speed Restrictions
Navigational Equipment
Officer and Crew Training
Use of Automatic Pilots
Construction and Design of Tankers
Identification and Charting of Hazards
(b) Remedial Measures:
Procedures in the Event of Accidents
Research on Oil Clearance
(c) Legal Measures:
Legal Rights of a Coastal State
Official Inquiries
Liability in Event of Accidents
Compulsory Insurance for Tankers
Movement of Salvage Equipment
Technical proposals were assigned to IMCO's standing
Subcommittees for study and to cope with the legal
questions there was established under the Council a Legal
Committee. On the suggestion of the United States, these
groups were given wide latitude in their studies.
The IMCO program on control of pollution has pro-
ceeded at a steady pace and at Annex III is the record of
actions taken by the Assembly in 1968 and 1969.
Resolution 175 was the most significant action, amend-
ing the Convention on Prevention of Pollution of the Seas
by Oil. The changes were directed toward promoting use of
the "load on top" procedure in tankers. This is the
technique currently employed in such vessels which in-
volves decanting of the tank washings during the cleaning of
tanks and the drawing off of water from beneath the oil.
The remaining oil and water mixture is transferred to a slop
tank and there further decanted. Eventually, the residue is
mixed with the next cargo which is added on top of the
slops. Evaluation of this procedure started in 1965 by the
IMCO Subcommittee on Marine Pollution which found that
the load on top procedure, during certain phases, contra-
vened the Oil Pollution Convention and suggested a number
of possible modifications to bring it more nearly into
compliance. Resolution 175 recognized that, notwithstand-
ing its shortcomings, the load on top procedure offered a
means of reducing the amount of oil going into the sea and
should be encouraged.
1969 Revision of the Ofl Pollution Convention:
The principal change eliminates the free zones in which
dumping or discharge of oil is not regulated with an
exception that the ship or tanker be proceeding en route
-------
INTERNATIONAL ACTIVITY ... 31
and that the "instantaneous rate of discharge of oil
content" does not exceed 60 litres per mile.
In ships other than tankers, discharge must be made as
far as practical from land, and the oil content less than
100 parts per 1,000,000 of the mixture.
The amount of oil so discharged from a tanker must be
limited to 1/15,000 of the total cargo-carrying capacity and
the discharge must take place more than 50 miles from the
nearest land. This would not apply to ballast from a cargo
tank which if discharged from a stationary tanker into calm
water on a clear day, would leave no visible trace of oil on
the water.
Another change eliminates the exemption for discharge
of oily residues.
A twelve-month period is allowed for vessels to change
oil drainage and bilge systems, after which they would be
required to comply with the amended Convention.
Brussels Conventions:
Pursuant to Resolution 171, in November 1969 an
International Legal Conference was held in Brussels, Bel-
gium, resulting in two Conventions entitled:
(1) The International Convention Relating to Interven-
tion on the High Seas in Cases of Oil Pollution
Casualties.
(2) The International Convention on Civil Liability for
Oil Pollution Damage.
The Convention Relating to Intervention on the High
Seas is important in dealing with oil pollution hazards on
the high seas since at present it is unclear under interna-
tional law what rights a State has to take action against a
foreign-flag vessel beyond its territorial sea. The Convention
permits Parties to take such measures on the high seas as
may be necessary to prevent, mitigate or eliminate a "grave
and imminent" danger of pollution by oil to their coastline
or related interests. Except in extreme urgency requiring
immediate measures, a coastal State exercising these rights
is required to first consult with other States affected by the
maritime casualty, and to notify persons whose interests
would be affected. Measures so taken must be proportion-
ate to the actual or threatened damage. The vessel owner
may question the measures taken and receive compensation
for unjustified coastal State action.
The Convention on Civil Liability establishes rules
relating to the liability of the owner of an oil carrying vessel
to governments and private parties for the damages caused
by oil pollution. Under the Convention the owner of the
vessel is liable in all cases for oil pollution damage except
when he can prove that the damage was caused by: (a) an
act of war, other hostilities, or act of God ("a natural
phenomenon of an exceptional inevitable and irresistible
character"), (b) an act or omission done with intent to
cause damage by the person suffering damage or by a third
party, (c) negligence of the person suffering damage, or (d)
negligence of a government. Procedures are set forth
whereby the shipowner may limit his liability (per incident)
to $134 per gross registered ton or $14 million, whichever
is lesser; the limitation is not permissible if the incident
occurred as the result of "the actual fault or privity of the
owner." Once this fund specified for meeting damage
claims in a given incident has been established, claims for
pollution damage arising out of that incident may not be
invoked against any other assets of the owner. Another
requirement is that the owner of a ship carrying over 2,000
tons of oil in bulk as cargo maintain insurance or other
financial security sufficient to cover his potential liability
under the Convention.
1970-71-The Age of Environment
Just as the seventies opened, explosions occurred in
three supertankers in the space of one week. This did not
lead to pollution as some wrongly supposed, because the
ships were ballasted and in process of cleaning tanks on the
return leg to the Persian Gulf. However, these incidents
underscored the safety problems in transport of bulk crude
oil. As the year progressed, Murphy's Law (if anything can
go wrong, it will) seemed to be in full effect as collisions
and strandings of oil tankers and blowouts in offshore oil
drilling 'operations occurred with perverse frequency, rivet-
ing the world's attention on the pollution issue.
In February 1970, the IMCO Subcommittee on Ship
Design &.Equipment reported that as regards ship design
and construction, present technology afforded no immedi-
ately practical means to reduce risk of collision or
stranding. Improvements could, however, be sought
through new devices such as high-powered lateral thrusters,
braking devices and controllable pitch propellers and
research on these units was under way in several countries.
It was recognized that these risks could be reduced by
the extension of the concept of separation of traffic and
improvement of the rules for preventing collisions at sea,
both of which were under active development by the
Subcommittee on Safety of Navigation. The Ship Design
Subcommittee did, however, draw up a suggested format
for presentation of maneuvering and stopping data to be
carried on the bridge of large vessels for the information of
the master and watch officers.
With regard to measures to limit the escape of oil should
collision or stranding occur, the MSC noted that the size of
individual tanks was increasing with increase in size of
tanker so that the amount of oil that could escape from a
single accident was becoming enormous. The Subcommittee
on Ship Design was instructed to investigate the economic
impact of installing additional bulkheads on the cost of ship
construction and operation. The United States Delegation
urged that IMCO evaluate the implications of increasing
tank size in supertankers from an ecological as well as a
naval architectural standpoint.
When the MSC met in October 1970, it agreed as an
interim measure to recommend that no further increases in
-------
32 LAWS AND ENFORCEMENT
tank size should be contemplated and set as a provisional
upper limit 30,000 cubic meters for a wing tank and 50,000
cubic meters for a center tank. The U.S. Delegation
consented to this proposal purely for interim purposes. The
MSC agreed that the lower values should be adopted if at all
practicable and instructed the Subcommittee on Ship
Design and Equipment to deal with the determination of
feasible reduction in tank size limits as a matter of the
highest urgency.
NATO:
Then in November 1970, Secretary of Transportation
Volpe addressing the opening session of NATO Conference
on Challenges of Modem Society propose'd that the nations
there assembled resolve to achieve "by mid-decade a
complete halt to all international discharge of oil and oily
wastes into the oceans by tankers and other vessels." With
the change that this should be achieved by mid-decade if
possible and certainly by 1980, this resolution was adopted.
Detailed recommendations agreed to by NATO nations to-
ward this end involve: (1) Early ratification of the 1969
amendments to the Convention for the Prevention of
Pollution of the Sea by Oil, (2) support and acceleration of
the work on the part of international organizations,
particularly IMCO, on development of equipment and
procedures for ship safety, and for measuring and control-
ling oil content of discharges and (3) the improvement of
reception facilities for oily wastes.
In effect, Secretary Volpe proposed that at last the
world should set the date which could not be fixed in 1954.
IMCO-1971:
The NATO proposal was advanced by the U.S. Delega-
tion at the March 1971, meeting of the IMCO MSC and will
lead to an acceleration ot* that organization's work program.
The MSC also adopted additional traffic separation schemes
bringing the total number to 65. The location of these
schemes are listed as Annex IV. Additionally, in an unusual
action, the MSC agreed that member governments should
make it an offense for ships of their registry which transit
any of the adopted traffic separation schemes to proceed
against the established direction of traffic flow.
Other Committee actions included study by the Sub-
committee on Safety of Navigation of recent incidents in
the English Channel relative to a possible need to unify the
buoyage system used in international waters, particularly
those marking wrecks and other dangers to shipping;
performance standards for navigational radar equipment
were approved; and a recommendation was adopted on
improving the reliability of the steering gear in large ships.
Studies were authorized on promulgating navigational
warnings to shipping and on enhancing safety of navigation
through the Straits of Dover. Responding to a proposal
submitted by Australia an amendment of the Oil Pollution
Convention was prepared to prohibit discharge of oil within
50 miles of the Great Barrier Reef.
The Committee also considered the results of the two
tasks of the Subcommittee on Ship Design & Equipment
mentioned earlier.
The increased cost of building and operating oil tankers
corresponding to reduced volume of individual tanks was
evaluated by means of the parameter Required Freight Rate
(RFR)-the cost to transport one ton of cargo without
profit.
where
SE = operating cost per year
/ = investment cost
=
(1 + /V* — 1
amortization coefficient at in-
terest rate i for an amortiza-
tion time length of n years
Ta = tons of cargo carried per year.
The study was carried out for tankers of 140,000, 227,000,
312,000 and 425,000 DWT, in each case with subdivision
arrangements ranging from 4 sets of tanks to 12 sets of
tanks. Longitudinal bulkheads were assumed placed at 1/4
and 1/3 the beam inboard of the side.
Using the relative increase in RFR permits neglecting
such factors as taxes and net profit which vary from one
nation to another and from time to time. The diagram
appearing as Annex V gives the essential results. While
recognizing its simplifications, the study procedure has
been concurred in by the tanker industry, except for an
opinion that the Subcommittee somewhat underestimated
the capital cost per ton of construction. This would shift
the absolute scale but would not significantly alter the
relative results. A similar effort by the International
Chamber of Shipping appears as Annex VI on which also is
shown the variations of "hypothetical oil outflow" men-
tioned below.
The Subcommittee also developed a proposal to limit
arrangement and size of tanks in future tankers to minimize
oil outflow in the event of collision or stranding. The
Subcommittee tried to allow the designer maximum free-
dom while promoting installation of defensive measures
such as double bottoms and wing void spaces. Standard
damage conditions were assumed for stranding and for
collision against which are evaluated the volume of tanks
breached. For collision breaching the hull at a bulkhead
between two wing tanks, all of the oil is assumed to escape.
In stranding, opening the bottom at the junction of four
tanks, 1/3 of the oil is assumed to escape unless certain
special arrangements have been provided. The consequence
of these injuries should not exceed a "hypothetical oil
outflow" limit which was left to the MSC to decide:
-------
INTERNATIONAL ACTIVITY . ..
33
In March 1971, the MSC determined that this figure
should not exceed a fixed quantity of 30,000 cubic meters
of oil. The proposal was drawn up as an amendment to the
Convention for the Prevention of Pollution of the Sea by
Oil and will be acted upon by the Assembly this fall. The
text of the resolutions and amendments appear at Annex
VII. If adopted as drafted, this requirement will affect all
tankers contracted for after 1 January 1972.
In addition to these technical activities, the Legal
Committee of IMCO is at work on preparations for a
Conference in Brussels in December 1971, to establish an
international fund to compensate for damage from oil
spillage. The fund would draw its resources from all
persons or companies (public and private) that import oil by
sea. The U.S. feels a condition for participation in the fund
should be that shipowners meet certain technical require-
ments toward preventing pollution incidents such as devel-
oped by IMCO.
Future Developments:
In the fall of 1971 the Assembly will act on the product
of the work program of the past two years. Additionally,
the aforementioned Legal Conference on the compensation
fund will take place. In 1972, United Nations Conference
on the Human Environment is scheduled, to be followed in
1973 by a Conference on Marine Pollution under IMCO
auspices to deal with maritime aspects arising from the
1972 UN. Conference. Also in prospect is a conference in
1973 or 1974 to revise the Rules for the Prevention of
Collisions at Sea. Studies are under way in the technical
Subcommittees to modify the Load Line or Safety Conven-
tions to extend subdivision measures to control floodability
of a ship's machinery space. The Subcommittee on Ship
Design will be looking into improving the stopping and
maneuverability of vessels. By 1975 or 1976, a need to
revise the Safety Convention will necessitate a Conference
because of many changes in construction requirements
since the 1960 Conference.
What's Missing:
Over the past 9 years, the author has been U.S.
representative and advisor to nearly all the technical
subcommittees and the Maritime Safety Committee. He
considers IMCO one of the most useful and productive of
international forums and has nothing but admiration for its
dedicated staff and profound respect for the competence .of
those representing other governments. However, the agenda
of the MSC is very full in dealing with the technical work of
its functionally aligned subcommittees. The MSC, in the
author's opinion needs to provide an up-dated central
philosophy which would permit effective tradeoff between
construction and operational requirements.
'Commander Warren D. Andrews, a brilliant young officer, was
struck down by a stray ballet while passing, unaware, the scene of
a resisted arrest
Internationally, a great deal has been done and is
continuing in connection with pollution abatement, but
there is still lacking a comprehensive analysis to decide
priorities. This is not easy to achieve and definitive results
are not assured. Attached at Annex VIII is a draft of such
an analytic approach dealing with accidents leading to
pollution. This was drawn up by the Planning Staff of the
Office of Merchant Marine Safety, Coast Guard Headquar-
ters over two years ago. However, owing to the untimely
death of one of its leading members,* the project was set
back severely and was never undertaken because of the
press of other requirements. (Development of the severity
factor "R" is particularly difficult.)
Analyzing control of pollution from "routine" opera-
tions, is even more involved. This relates to Secretary
Volpe's proposal to NATO, to completely eliminate all
discharges of oil to the sea. Virtually all existing tankers
and other ships were designed with some such discharge as a
tolerated practice.
To gain a little insight into the breadth of this matter,
consider eliminating tank washings from tankers. There are
five'conceivable "pure" alternatives:
(a) Construct the tankers with sufficient clean ballast
space that water need not be taken into the cargo
tanks. This would require more expensive hulls with
reduced cargo deadweight capability for the volume.
New ships constructed on this line would not enter
service considering the present backlog of orders
before 1975 or 1976. Existing ships could of course
be converted to this mode of operation by eliminat-
ing certain percentage of the tankage. That would
have the effect of reducing suddenly the total
available lift capacity the world over and would lead
to an almost immediate shortage of oil.
(b) Contrive means of keeping oil and water separated
by a barrier or film to allow putting first oil and
later water into the same tank. This scheme would
be fitted in sufficient tanks to cover the ballast
requirement, say 30%. This is easier said than done
owing to the fact that crude oil is an impure product
full of sand and sludge forming heavy deposits on
surfaces. There would also be problems of access and
the dimensions involved should not be ignored as a
difficulty.
(c) Develop an oily water separator that will totally
eliminate the emission of oil in the discharge. The
flow rate required is in terms of hundreds of tons
per hour and an effective oil content meter is
necessary to insure control. These devices have been
sought for the last 15 years or more without signal
success. These devices are needed to enhance the
reliability of the load on top procedure. It is
conceivable that separation devices could be fur-
nished at shore side reception facilities where there
is no restriction as to space, weight, power or time,
if not for shipboard use.
-------
34 LAWS AND ENFORCEMENT
(d) After discharge of the cargo, clean the tanks at a
special cleaning station before authorizing the vessel
to return to sea and take on ballast. The ship would
then sail approved as clean enough to take on and
discharge ballast freely. Such stations would involve
extensive capital investments in the oil consuming
countries and would perhaps add a delay of three
days to the schedule of tankers which is tantamount
to a reduction in the world carrying capacity.
(e) Build reception facilities ashore to receive the oily
water before loading a fresh cargo. These faculties
would have to be located at the point from which
the oil is taken, primarily the Persian Gulf, North
Africa, Southeast Asia, and Caribbean. These facili-
ties would necessitate a capital investment, the
construction of facilities and the obtaining of the
operating technicians.
It is obviously possible to have a mix of these five
alternatives and if we were only dealing with the problem
of disposition of tank washings from tankers it would not
be too difficult to discern where to make the investment.
However, Secretary of Transportation Volpe's proposal to
NATO also embraces the elimination of bilge and oily
ballast discharge from conventional vessels. Although there
is less of this waste by far per ship there are many more
such ships and unlike tankers, which have a relatively fixed
routing, the ports of call for conventional vessels are many
and far flung. Consequently, in the total picture capital
investment in reception faculties on a world wide scale
seems essential if the objective of eliminating discharges of
oil to the sea is to be attained.
There needs to be an extensive analysis to determine
how best to dedicate resources on a global basis. As far as
the author is aware no such analysis has yet been
undertaken.
CONCLUSION:
From this account of the international activity over the
past 50 years directed against oil pollution, two conclusions
can be drawn. First, had the problem been simple or
economic to solve, it would have been solved a long time
ago. Second, it is time the control of oil pollution was
finally achieved.
-------
INTERNATIONAL ACTIVITY
35
APPENDIX: 1
TABLE I—December 1960
U.S.A. SEA PORT AND LAKE PORT SHIPYARDS OF.VARIOUS CATEGORIES
STATIONARY AND MOBILE FACILITIES FOR OILY WATERS, IN LONG TONS OF 2,240 POUNDS
Tort area
New York
Los Arigfctes
Seattle
Total
Total 1955. . —
Num-
IXTOl
yards
G
9
i
l-
13
•j
6
69
55
Stationary facilities
Tanks
Num-
ber
20
19
3
10
13
9
17
17
110
93
Tons
415
3.91.2
•> MS
1 i~<;
3*2
137
IC.'SW
42.125
32. 55'J
Pond sepa-
rators
Num-
ber
""G
o
10
2
24
20
Tons
1.032
"'S
2. 461
i.7f3
SO
C.OS9
12,423
Total
Num-
ber
20
23
S
1«
IS
9
27
19
131
US
Tons
415
4.994
2. HI ii
4,021
6.9S7
3S2
l.^O
2ii, 910
48.214
44. 9>2
Mobile facilities
Barges
Num-
ber
5
8
17
9
1C
10
18
80
PI
Tons
7.292
1.G74
1.300
7,9211
94(i
1,852
785
2.593
24,302
23,459
Tank ears
Num-
ber
12
9
7
4
8
2
42
56
Tons
308
293
247
2S
309
130
1.375
1.423
Tank tracks
Num-
ber
2
4
"I
10
37
33
Tons
10
62
369
50
491
361
Portable
tanks
Num-
ber
3
15
18
125
Tons
30
540
570
S63
Total
Num-
ber
19
5
17
•M
9
27
39
45
187
295
Tons
T.600
1.674
1.593
xir;
94-5
1,972
1.523
3.313
2-5.79S
26.106
Totfil ill
facilities
Num-
ber
39
28
20
44
24
36
06
64
321
113
Ton?
Ji.C'15
t>.er-
minnls
503
3. 2A5
S. 175
'M!
5. 70s
9,790
7.030
9.025
U, MS
4. 435
4, 7S3
3. 3'Jl
4. 3'JO
1.211
Gfi. 9M
C2.UI1
Oily water storage capacity
Tanks
Num-
ber
6
20
14
3
7
13
2
10
17
9
7
S
G
3
125
124
Lone
tons
1.459
39. 01S
S3. 3DS
l.t'SO
32.5*5
49,720
11.571
47.9S3
12.640
2S.543
u. 97
S7. wlO
31.77o
53.M7
120. 709
3i. 3S4
15.53S
15.6-VI
6. V
44. K3
1U3. SIC
1.CC1
571.7*1
3S7, 14!
Total
Num-
ber
10
3)
27
16
10
*v>
10
16
£s
15
11
19
&
3
232
217
Isr-Z
toes
4. NO
H.O.J5
UJ.WS
»ibc«
V5.0V2
1:0. ias
40.955
63.53
%3M
34.6*5
Ii.'J4
117,361
17.167
3,492
?j-. 175
t-a,>ii
-------
36 LAWS AND ENFORCEMENT
APPENDIX: 2
APPENDIX: 3
October 1968—Resolutions of an Extraordinary
Session of the Assembly:
Resolution No.
146—Amends SOLAS 1960 to require radar, radio
direction-finding gear, gyro compass, echo sounder,
nautical publications and use of automatic pilot.
147—Requires masters to report all accidents in which
they are involved to a government appointed officer
or agency if an oil spill occurs or is probable.
Governments to insure that such reports are for-
warded to the appointed officer or agency promptly
and to provide IMCO with information designating
appointed officers or agencies for circulation to
member nations.
148—Governments to implement arrangements in order
to deal with significant spillage of oil from ships.
149—Regional cooperation in dealing with significant
spillages of oil, such as among the North Sea
countries.
150—Research and exchange of information on methods
for disposal of oil in cases of significant spillages.
151-Govemments to cooperate in detection of offenses,
enforcement of provisions, and investigation of
infractions of the International Convention for the
Prevention of Pollution of the Seas by Oil.
152—Encourages development and use of any possible
system or device whereby oily mixtures from tank
cleaning or ballasting are not discharged into the sea.
153—Urges review of national laws on penalties for
unlawful discharge of oil outside the territorial sea to
insure adequate severity, to improve penalties if
necessary and submit study and results to IMCO.
Prosecuting authorities to be given instructions as
will enable systematic proceedings to be taken
against any unlawful discharge of oil. Proposals for
amending the 1954 Oil Convention in order to more
severely penalize unlawful acts of pollution to be
prepared in time, if possible, for consideration of the
next IMCO Assembly meeting.
154—Governments are to report installation or changes
of oil reception facilities to IMCO for distribution,
to encourage studies on how facilities can be used
more effectively and to encourage ships under their
flag to use shore reception facilities where available.
155-The Maritime Safety Committee of IMCO to insure
that amendments to the Oil Pollution Convention
(especially in respect to prohibiting the discharge of
oil outside the prohibited zone) are proposed in time
for the next session of the IMCO Assembly, and the
need for amendment as regards to detection and
enforcement of deliberate pollution be determined.
156-Ships to carry an efficient electronic position-
fixing device suitable for the trade in which em-
ployed and appropriate amendment of SOLAS 1960
to be prepared for consideration by the IMCO
Assembly.
157-Recommendation on the use and testing of ship-
borne navigational equipment. Importance of mak-
ing most effective use of all navigational aids to be
brought to notice of ships' masters. Operational tests
of shipborne navigational equipment to be carried
out as frequently as possible at sea, particularly
when hazardous navigation is expected. Tests to be
recorded in the Log Book. Development and use of
reliable speed and distance indicators to be encour-
aged.
158—Recommendation on port advisory services, partic-
ularly in terminals and ports where noxious or
hazardous cargoes are handled, and requiring masters
to give early indication of expected time of arrival.
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INTERNATIONAL ACTIVITY . . .
37
159-Recommendation on pilotage services to be organ-
ized as a contribution to safety of navigation. Ships
for which pilot services are mandatory to be defined.
160-Recommendation on data concerning maneuvering
capabilities and stopping distances on ships to be
available on the bridge for various conditions of
draught and speed.
161-Recommendation on establishing traffic separation
schemes and areas to be avoided by ships of certain
classes. Adopts terms, definitions and general prin-
ciples concerning traffic separation and routing.
Requests the IMCO Maritime Safety Committee to
keep the subject of traffic separation schemes under
continuous review.
162—Recommendation on additional day and night
signals for deep-draught ships in narrow channels.
171-Convening of a conference on public and private
law aspects of pollution damage resulting from
maritime casualties to be held in November 1969, in
Brussels.
172—Recommendation for uniform application and
interpretation of Regulation 27 of the International
Convention on Load Lines, 1966. Governments to
give effect to this recommendation as soon as
possible.
173-Participation in official inquiries into maritime
casualties. A state affected by or having an interest
in a maritime casualty to be allowed participation in
the inquiries or other such proceedings relative to
the casualty.
Activity in 1969:
In October 1969, the IMCO Assembly met in London
for its sixth regular session, and adopted the following
resolutions:
175—Amends the International Convention for the
Prevention of Pollution of the Sea by Oil. (To be
explained in this paper.)
176-Noting the U.N. Conference on Human Environ-
ment scheduled for 1972, decides on an interna-
tional conference on Marine Pollution for 1973 to
consummate agreement on international restraint of
contamination of the sea, land and air by ships,
vessels and other equipment in the marine environ-
ment.
177-Recommends performance standards for naviga-
tional lights to ensure early identification among
vessels of their respective attitudes and conditions of
operation.
178—Recommends adoption of rules for positioning of
navigation lights to increase accuracy in estimating
the aspect of observed ships.
179-Recommends establishment of fairways or shipping
routes through off-shore exploration areas to ensure
that exploitation of sea-bed resources does not
obstruct shipping routes.
180—Recommends location of off-shore platforms be
disseminated by Notices to Mariners and/or radio
warnings.
182—Recommends off-shore platforms and associated
ships, aircraft and land stations be fitted with
maritime mobile safety radiocommunications equip-
ment.
186-Adopts traffic schemes in the approaches to New
York Harbor, Santa Barbara and Delaware Bay, long
with schemes for other areas in Europe and South
Africa.
188—Recommends the "Document for Guidance—
1968" on training of masters, officers and crew to
supersede one approved earlier.
189-Study on need of centralizing in IMCO the
statistical experience of oil spills.
192—Authorizes study and preparations for a conference
revising the Regulations for Preventing Collisions at
Sea, 1960, to be held in 1972.
APPENDIX: 4
Traffic Separation Schemes
A. Baltic Sea:
1. Off Sommers Island
2. Off Hogland (Gogland) Island
3. Off Rodsher Island
4. Off Kalbadagrund Lighthouse
5. Off Porkkala Lighthouse
6. Off Hankoniemi Peninsula
7. Off Kopu Peninsula
8. Off Gotland Island
9. Off Oland Island
10. Approaches to Rostock
11. In the Sound
B. Western European Waters
1. Off the Oslo Fjord
2. OffOksoy
3. OffLindesnes
4. OffLista
5-6. OffFeistein
7. In the German Bight
8. At North Hinder
9. North of Sandettie Bank
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38 LAWS AND ENFORCEMENT
10. In the Strait of Dover
11. Off Lizard
12. Off Lands End
13. South of the Scilly Isles
14. West of the Scilly Isles
15. Off Smalls
16. Off Skerries
17. Off Chicken Rock
18. In the North Channel
19. Off Tuskar Rock
20. Off Fastnet Rock
21. OffCasquets
22. OffUshant
23. Rochebonne Shelf
24. Off Finisterre
25. Off Cape Roca
26. Off Cape St. Vincent
27. At Banco del Hoyo
28. Off Hook of Holland
C. Mediterranean and Black Sea
1. In the Strait of Gibraltar
2. Off Card Island
3. Off Cape Bon
D. Indian Ocean and Adjacent Waters
1. In the Gulf of Suez
2. In the Southern portion of the Red Sea
3. In the Bab el Man deb Strait
4. In Hormuz Strait
5. In Persian Gulf
E. Off South Africa
1. Cooper Point
2. South Sand Bluff
3. Bashee Point
4. Hood Point
5. Great Fish Point
6. Cape Recife
7. Seal Point
8. Cape Agulhas
9. Quoin Point
10. Slangkop Point
11. Alphard Banks
F. Far East and South East Asia
1. Cape Terpenie (Sakhalin)
G. America, Atlantic Coast
1. Off New York
2. Off Delaware Bay
3. In the approaches to Chesapeake Bay
4. OffChedabuctoBay
H. America, Pacific Coast
1. Off San Francisco
2. In the Santa Barbara Channel
APPENDIX: 5
RFR VERSUS SWCffD VOUJME OF WNGWKS
SHIP A 14000 TWO-HFE
B 227000 "
- C 3BOOO •
- D «5000 •
TOMMCODE Vl/ll ANNEX III
5,00
450
350
vc( of single wing tanks (in c/mvWH
APPENDIX: 6
trfo soxtwn1^
-XK
2QDOO
FrcmMCOMSC XXH82
fig «5
-------
INTERNATIONAL ACTIVITY . . .
39
APPENDIX: 7
MARITIME SAFETY COMMITTEE
23rd Session
Agenda item 8
LIMITATION OF TANK SIZE OF OIL TANKERS
FROM THE POINT OF VIEW OF MINIMIZING
POLLUTION OF THE SEA BY OIL
Draft Resolution
Amendments to the International Convention for
the Prevention of Pollution of the Sea by Oil, 1954
THE ASSEMBLY,
NOTING Article 16(i) of the Convention on the
Inter-Governmental Maritime Consultative Organization
concerning the functions of the Assembly,
BEING CONSCIOUS of the responsibility of the Organ-
ization for taking effective measures for the prevention and
control of pollution of the marine environment which may
arise from maritime activities,
REALIZING that notwithstanding the adoption by the
Organization of various measures for preventing collisions
and strandings of ships, it is not possible to eliminate
entirely accidents which may lead to release of oil, but
desiring to minimize ensuing damage to the environment,
RECOGNIZING that construction of oil tankers of large
size without accompanying control of size or internal
arrangement of cargo tanks leads to the possibility, in the
event of a single accident, of serious environmental pollu-
tion,
HAVING EXAMINED the recommendations relating to
tank arrangements and to the limitation of tank size
prepared by the Maritime Safety Committee at its twenty-
third session,
CONSIDERING that the universal implementation of
such requirements can best be achieved by amending the
International Convention for the Prevention of Pollution of
the Sea by Oil, 1954,
NOTING that Article XVI of the International Conven-
tion for the Prevention of Pollution of the Sea by Oil, 1954
provides for procedures of amendment involving participa-
tion by the Organization,
ADOPTS the following Amendments to the Articles and
Annexes to that Convention, the texts of which are
attached to this Resolution:
(a) the addition of a new Article VI bis, and
(b) the addition of a new Annex [C],
REQUESTS the Secretary-General of the Organization,
in conformity with subparagraph (2)(a) of Article XVI to
communicate for consideration and acceptance, certified
copies of this Resolution and its attachment, to all
Contracting Governments to the International Convention
for the Prevention of Pollution of the Sea by Oil, 1954,
together with copies to all Members of the Organization,
INVITES all governments concerned to accept the
Amendments at the earliest possible date, and
DETERMINES in accordance with paragraph (5) of
Article XVI that these Amendments are of such an
important nature that any Contracting Government which
makes a declaration under paragraph (4) of Article XVI and
which does not accept the Amendments within a period of
12 months after the Amendments come into force, shall,
upon the expiry of this period, cease to be a party to the
present Convention.
ARTICLE VI bis
(1) Every tanker to which the present Convention applies.
' and for which the building contract is placed on or
after the date of coming into force of this Article shall
be constructed in accordance with the provisions of
Annex [C]. In addition, every tanker to which the
present Convention applies and for which the building
contract is placed, or in the absence of a building
contract the keel of which is laid or which is at a
similar stage of construction, before the date of coming
into force of this Article shall be required, within two
years after that date, to comply with the provisions of
Annex [C], where such a tanker falls into either of the
following categories:
(a) a tanker, the delivery of which is after 1 January 1977;
or
(b) a tanker to which both the following conditions apply:
(i) delivery is not later than 1 January 1977; and
(ii) the building contract is placed after 1 January
1972, or in cases where no building contract has
previously been placed, the keel is laid or the
tanker is at a similar stage of construction after
30 June 1972.
(2) A tanker required under paragraph (1) of this Article to
be constructed in accordance with Annex [C] and so
constructed shall carry on board a certificate issued or
authorized by the responsible Contracting Government
attesting such compliance. A tanker which under
paragraph (1) of this Article is not required to be
constructed in accordance with Annex [C] shall carry
on board a certificate to that effect issued or au-
thorized by the responsible Contracting Government, or
if the tanker does comply with Annex [C] although
not required to do so, it may carry on board a
certificate issued or authorized by the responsible
Contracting Government attesting such compliance. A
Contracting Government shall not permit such tankers
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40 LAWS AND ENFORCEMENT
under its flag to trade unless the appropriate certificate
has been issued.
(3) Certificates issued under the authority of a Contracting
Government shall be accepted by the other Contracting
Governments for all purposes covered by the present
Convention. They shall be regarded by the other
Contracting Governments as having the same force as
certificates issued by them.
(4) If a Contracting Government has clear grounds for
believing that a tanker required under paragraph (1) of
this Article to be constructed in accordance with
Annex [C] entering ports u> its territory or using
off-shore terminals under its control does not in fact
comply with Annex [C], such Contracting Government
may request consultation with the Government with
which the tanker is registered. If, after such consulta-
tion or otherwise, the Contracting Government is
satisfied that the tanker does not comply with Annex
[C], such Contracting Government may for this reason
deny such a tanker access to ports in its territorial
waters or to off-shore terminals under its control until
such time as the Contracting Government is satisfied
that the tanker does comply.
ANNEXC
Requirements Relating to Tank Arrangements
and to the Limitation of Tank Size
Assumed Extent of Damage
In the following paragraphs three dimensions of the
extent of damage of a parallel piped due to both collision
and stranding are assumed. In the case of stranding, two
conditions are set forth to be applied individually to the
stated portions of the ship. These values represent the
maximum assumed damage in such accidents and are to be
used to determine by trial at all conceivable locations the
worst combination of compartments which would be
breached by such an accident.
Collision
Longitudinal extent (/r):
Transverse extent (fc)
inboard from the ship's
side at right angles to
the centreline at the
level of the load line:
Vertical extent (yc):
Stranding
1/2/3
or 14.5 m, whichever is
less
B
— or 11.5 m, whichever is less
from the base line upwards
without limit
For 0.3L from
the forward
perpendicular
of the ship
Any other
part of
the ship
Longitudinal ex tent (/s): —
n
Transverse -extent (ts): -7- or 10.0 m,
whichever is less
5m
5m
Vertical extent (vs)
from the base line:
B_
15
or 6 m, whichever is less, for
any part of the ship
where: L, B in metres and perpendicular are as defined in
Regulation 3 of the International Convention on
Load Lines, 1966
HYPOTHETICAL OIL OUTFLOW FROM TANKS
ASSUMED TO BE BREACHED AS A RESULT
OF THE ACCIDENT
The hypothetical oil outflow in the case of collision (Oc)
and stranding (Os) should be calculated by the following
formulae with respect to compartments breached by each
assumed location of damage as defined in Section 1.
Collision
Oc =
Stranding
where:
(0
(2)
o
Wf = volume of a wing tank in m breached by
the damage assumed in Section 1; Wj for a
clean ballast tank may be taken equal to zero,
Ci = volume of a centre tank in m breached by
the damage assumed in Section 1; Cj for a
clean ballast tank may be taken equal to zero,
Kf= 1 ; when £>,- is equal to or greater than £,
'c
KJ should be taken equal to zero,
_h(
Zj = 1 —=- ; when A,- is equal to or greater than vs,
""-Vs
Zj should be taken equal to zero,
h{ = width of wing tank in m under consideration,
hj = minimum depth of the double bottom in m
under consideration; where no double bot-
tom is fitted, hi should be taken equal to
zero
wing tank = any tank adjacent to the side shell
plating,
centre tank = any tank inboard a longitudinal
bulkhead.
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INTERNATIONAL ACTIVITY ... 41
Special requirements
If a void space or clean water ballast tank of a length less
than/c as defined in first section is located between wing oil
tanks, Oc in formula (1) may be calculated on the basis of
volume W{ being the actual volume of one such tank (where
they are of equal capacity) or the smaller of the two tanks
(if they differ in capacity) adjacent to such space, multiplied
by Si as defined below and taking for all other wing tanks
involved in such a collision the value of the actual full
volume.
where:
/,- =
length in m of void space or clean ballast
tank under consideration.
(a) Credit should only be given in respect of double
bottom tanks which are either empty or carrying
clean water when cargo is carried in the tanks above.
(b) Where the double bottom does not extend for the
full length and width of the tank involved, the
double bottom is considered non-existent and the
volume of the tanks above the area of the stranding
damage is to be included in formula (2) even if the
tank is not considered breached because of the
installation of such a partial double bottom.
(c) Suction wells may be neglected in the determination
of the value hi provided such wells are not excessive
in area and extend below the tank for a minimum
distance and in no case more than half the height of
the double bottom. If the depth of such a well
exceeds half of the height of the double bottom, hi
should be taken equal to the double bottom height
minus the well height.
Piping serving such wells if installed within the
double bottom should be fitted with valves or other
closing arrangements located at the point of connec-
tion to the tank served to prevent oil outflow in the
event of damage of the piping during stranding.
Such piping should be installed as high from the
bottom shell as possible.
In the case where stranding damage simultaneously
involves four centre tanks, the value of Os may be
calculated according to the formula
Os =
(3)
An Administration may credit as reducing oil
outflow in case of stranding, an installed cargo
transfer system having an emergency high suction in
each cargo oil tank, capable of transferring from a
breached tank or tanks to segregated ballast tanks or
to available cargo tankage if it can be assured that
such tanks will have sufficient ullage. Credit for such
a system would be governed by ability to transfer in
two hours of operation, oil equal to one-half of the
largest of the breached tanks involved and by
availability of equivalent receiving capacity in ballast
or cargo tanks. The credit should be confined to
permitting calculation of Os according to formula
(3). The pipes for such suctions should be installed
at least at a height not less than the vertical extent
of the stranding damage vs.
The Administration should supply IMCO with the
information concerning the arrangements accepted
by it, for circulation to other governments.
LIMITATIONS OF SIZE OF CARGO OIL TANKS
Limitation of hypothetical oil outflow
The hypothetical oil outflow Oc or Os calculated in
accordance with the formulae in Section 2 should not
exceed 30,000 m3.
Limitation of volume of single tank
The volume of a wing tank should not exceed 22,500
m3..
The volume of a centre tank should not exceed 50,000
m3.
Limitation of tank length
The length of each tank should not exceed 10 m or one
of the foDowing values, whichever is greater:
(a) where no longitudinal bulkhead is provided:
O.IL
(b) where a longitudinal bulkhead is provided at the
centreline only:
0.15L
(c) where two or more longitudinal bulkheads are
provided:
(i) for wing tanks:
0.2L
(ii) for centre tanks:
(1) if ~ isfequal to or greater than —
13 5
0.21
b{ i
(2) if— is less than —:
D J
-where no centreline longitudinal bulkhead
is provided:
(0.5 ^ + 0.1) L
-where a centreline longitudinal bulkhead
is provided:
(0.25-' + 0.15) L
B
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42 LAWS AND ENFORCEMENT
DRAFT RESOLUTION
RECOMMENDATION TO PUT INTO EFFECT
REQUIREMENTS RELATING TO TANK
ARRANGEMENTS AND TO THE LIMITATION
OF TANK SIZE FROM THE POINT OF VIEW
OF MINIMIZING POLLUTION OF THE SEA BY OIL
THE ASSEMBLY,
NOTING Article 16(i) of the Convention on the
Inter-Governmental Maritime Consultative Organization
concerning the functions of the Assembly,
NOTING FURTHER that at its present session it
adopted by Resolution A. (VII) Amendments to the
International Convention for the Prevention of Pollution of
the Sea by Oil, 1954 concerning tank arrangements and the
limitation of tank size from the point of view of minimizing
pollution of the sea by oil,
INVITES all Governments concerned:
(a) to make known the provisions of the said Amendments
to shipowners and operators under their jurisdiction,
(b) to put into effect the said Amendments as soon as
possible without awaiting the entry into force of the
said Amendments with regard to ships intended for
their registry for which the building contract is placed
after the date on which this Resolution is adopted and
(c) to inform the Organization of measures taken by them
in this respect.
APPENDIX 8:
Outline
The purpose is to compare the relative effectiveness of
measures proposed to prevent or minimize potential pollu-
tion of the sea by oil from ship casualties.
The procedure involves considering circumstances in
which oQ may be released, taking into account the degree
of pollution which may occur and the likelihood of the
incident.
II. Potential Pollution Incidents: (not a complete list)
a. Collision with Ship — Busy Populated Port
b. Stranding - Populated Area
c. Collision with Ship at Sea < 10 miles
d. Collision with Ship > 10 < 100 miles at Sea
e. Collision with Ship - Small Unpopulated Port
f. Stranding — Isolated Area
g. Collision with Ship > 100 Miles at sea
h. Collision with Offshore Structure
i. Collision in Port with Dock
j. ...
III. Severity Factor: (R)
R is a factor to take cognizance of the seriousness of
any one of the potential polluting incidents, as regards the
quantity of oil which may be released, the difficulty of
controlling the released oil, problem of cleaning up, and
the extent of damage ensuing.
Thus, Ra is the severity of the incident "Collision with
Ship - Busy Populated Port."
IV. Frequency: (F)
F is the relative likelihood that any potential polluting
incident will occur. (Data on pollution are known to be of
limited quantity and detail, pollution having only recently
been recognized as a significant problem. Therefore, since
the method is entirely comparative, it could be valid to
draw upon the record of incidents listed befalling large
ocean-going vessels generally.)
Thus, Fa is indicative of the relative probability of
potential polluting incident "a. Collision with Ship - Busy
Populated Port."
V. Effectiveness: (£)
E is a factor to evaluate the utility of any Alternative
Measures as applied to any potential polluting incident.
Thus, E\a is defined as follows:
Number of incidents of Type a in which
Alternative 1 might be beneficial
la ~f Number of incidents of Type a
Elements Involved:
I. Alternative Measures: (not a complete list)
1. Training of Ship's Officers
2. Installation of Radar
3. Tank Size Limit
4. Tank Arrangement
5. Backing Power Requirement
6. Decreased Turning Circle
7. Sea Lanes
8
9
VI. Comparative Worth: (MO
W is the comparative worth of any Alternative Measure.
Thus the Worth of Alternative Measure 1 is:
= 2 (RaFa
. RnFnEln)
VII. Other Factors:
It is conceivable that in some Alternative Measures there
may be inherent an increase in risk of pollution. Such a
factor would have to be separately identified and a means
found for judging the negative contribution to Worth.
-------
THE OIL POLLUTION PROBLEM FROM
THE VIEWPOINT OF MARINE INSURANCE
Gordon W. Paulsen
Haight, Gardner, Poor & Havens
Together with Mr. Nicholas J. Healy of New York, who
has worked with me in the preparation of this paper, and to
whom I am greatly indebted, I, as an attorney, have
represented the major Protection and Indemnity
Associations—marine liability insurers—during the extensive
hearings which have been held for the last few years here in
the United States concerning the Insurance aspects of
proposed legislation respecting oil pollution by vessels. Our
clients have been referred to as the "London Group" of
Protection and Indemnity Associations, which together
insure the owners and operators of approximately three
quarters of the world's ocean-going tonnage against
liabilities including those resulting from oil spills. While
these Associations are called the "London Group", they are
not only British but also Norwegian, Swedish, Japanese,
Luxumbourgian and Bermudian. The assureds include
vessels of all nations including the United States. For a
number of reasons, United States insurers of these types of
liabilities manage their coverage in different ways and for
these reasons are not included in the "London Group."
Over one hundred years ago, as the maritime commerce
of the world grew rapidly, various groups of shipowners
found that the only way they could handle the risks of
claims being brought against them was to band together
mutually to insure one another's liabilities. The basic
principle was to be mutuality—that all of the members of
each Association were to be as nearly equal as possible with
respect to risks of exposure. The risks with which the
Protection and Indemnity Associations were concerned
included all legal liabilities except those covered by hull
insurance. By "legal liabilities" they included virtually all
liabilities imposed by law, among which were liabilities to
passengers who might be injured, to shippers whose cargo
might be damaged in transit, and liabilities to persons in no
way related to the venture who might be damaged as a
result of the operation of a vessel. There never has been any
doubt that one of the risks covered by the Protection and
Indemnity Associations was the risk of damage to persons
or property caused by accidental discharges of oil, provided
that the applicable law recognized such liability and,
further, provided that the facts established that the incident
came within the proscriptions of such law.
THE GENERAL MARITIME LAW AS APPLIED
BY THE ADMIRALTY COURTS OF THE
UNITED STATES IMPOSES LAIBILITY
UPON VESSEL OWNERS FOR OIL
POLLUTION
1. Damages
While there have been very few litigated cases
concerning the question, it has long been recognized by
Protection and Indemnity Associations that the general
maritime law imposes liability for damages resulting from
negligent discharges of oil. One case in which this question
is specifically discussed is In Re New Jersey Barging Corp.,
168 F. Supp. 925, 1959 A.M.C. 2532, 1956 A.M.C. 1338,
1955 A.M.C. 2270 (S.D.N.Y. 1958). Because of this
liability the Associations have, whenever the occasion
required, financed extensive clean-up measures to prevent
such liabilities from arising, or at least to keep them at a
minimum. For example, when there have been collisions or
groundings in which oil tanks have been ruptured the
Associations have paid for the measures required to contain
the oil and to prevent the oil's being spread to areas where
it could cause damage to persons or property. During the
Congressional hearings evidence was produced to show the
amounts which the Associations expended to contain oil
spills and also to pay damage claims when complete
containment was not possible. Obviously such expenditures
would not have been made if there had not been a
recognition that liability for such claims exists without any
legislation whatsoever.
43
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44 LAWS AND ENFORCEMENT
2. Government Clean-Up Costs
As I will discuss later, after the Torrey Canyon
grounding in international waters off the coast of England
in 1967, the British Government asked the
Intergovernmental Maritime Consultative Organization
(IMCO) to draft an International Convention concerning
the power of a government to act with respect to
containment and clean-up of oil spills occurring in
international waters. It was also feared that Her Majesty's
government might possibly be regarded by a Court as a
"good Samaritan" or volunteer if the government
undertook activities and would therefor not be entitled to
recover expenses incurred in connection with such
activities. I submit that the doubt as to power existed only
because the incident occurred in international waters and
that there is little doubt that a government would be
entitled to take measures to control the effects of an oil
spill in its own territorial waters-that such government
then would be held to be acting within its normal powers. I
also submit that any court hearing a claim for
reimbursement would not deny such claim on the ground
that the government was a volunteer or "good
Samaritan". As a matter of fact, the Governments of both
the United States and the Commonwealth of Puerto Rico
are taking the position that even without enabling
legislation they are entitled to recover under similar
circumstances. Thus, they are now claiming for such
clean-up costs in connection with the Ocean Eagle incident
which occurred at San Juan, Puerto Rico on March 3, 1968,
before enactment of P.L. 91-224.
I further submit that even in the event of a government
incurring costs of clean-up or minimization of damage to its
shores resulting from a high seas incident, there is little
doubt that the government would be able to recover from a
negligent shipowner. The best evidence that no legislation is
needed is the fact that the Torrey Canyon interests paid to
the French and British governments a total of over $7
million for the clean-up and preventive costs incurred in
that high seas incident even without any international
convention. Since the Protection and Indemnity
Association and the excess under-writers which paid these
amounts do not exist for the purpose of cleaning-up the
environment but to protect and indemnify their members
for payments with respect to legal liabilities, it appears to
me that this substantial payment is the best evidence that
legislation is not needed.
In view of the fact that liability for damages and
clean-up costs resulting from negligent discharges of oil
already exists under the general maritime law, and since
increasing such liabilities by making them absolute or
unlimited has no preventive effect whatsoever (but on the
contrary results in heavy expenditures by the maritime
industry and by government without any commensurate
benefit to the public) I submit that legislation regarding civil
liabilities in this field, is misdirected, and is at best a futile
exercise,and at worst simply fooling the public.
Nevertheless, since enactment of laws is apparently
regarded as a panacea for problems of almost any sort, let
us examine the history of legislation in this area in order to
ascertain whether or not there is a proper role for legislative
action with respect to control and prevention of oil spills.
THE ROLE OF LEGISLATION IN PREVENTING
OR REDUCING OIL POLLUTION FROM VESSELS
1. Enactment of New Legislation
Ever since the unfortunate grounding of the Torrey
Canyon there has been a great deal of time, money and
effort expended concerning legislation with respect to
liability for oil pollution from vessels. These efforts have
taken place in the international arena (through IMCO), at
the national level, and at state and local levels. The cost to
the governments has been enormous, and so has the cost to
the maritime industry. None of this monumental
expenditure has resulted in the clean-up of any waters or
the prevention of any oil spills-nor has it resulted in any
reimbursement to governments for clean-up costs beyond
that which they would have recovered in any event.
It appears to me that it is time to take a fresh look at
the role which legislation can play in preventing oil spills in
order to determine whether the public is receiving from
recent legislation now on the books any benefits
commensurate with the cost.
The British Government, in referring these questions to
IMCO, stated that it was refraining from enacting any
domestic legislation in this field and it was suggested that
other nations also refrain from enacting domestic legislation
pending agreement as to an international convention.
Nevertheless, the United States Senate on December 12,
1967 passed S.2760 which was designed to impose strict
liability on a vessel owner whose ship was involved in a
collision or stranding which resulted in an oil spill and to
deprive the owner of his right to limit liability for oil
pollution damage. A House Bill, H.R. 14,000, was similar to
S.2760. Whereas S.2760 had passed without any substantial
debate or public discussion, very extensive hearings were
conducted by the Sub-Committee on Rivers and Harbors of
the House Committee on Public Works, starting in April of
1968. As a result, H.R. 14,000 was substantially modified.
Senator Muskie's Sub-Committee on Air and Water
Pollution of the Senate Public Works Committee also held
public hearings concerning the implications of the proposed
house legislation.
At all of these hearings, the maritime community
pointed out that the proposed legislation would create risks
which were to some extent, at least, uninsurable and, to the
extent that some insurance was available, the cost to the
government and to the consumer would far outweigh any
possible benefit. It was pointed out again and again that
those portions of the bills which dealt with liability for oil
pollution from vessels would not prevent pollution and that
this type of legislation was not necessary since existing law
already covered the field. Of course, Congress could not
legislate with respect to the powers of governments to act if
incidents, occurred in international waters-this was a
subject for an international convention.
-------
THE VIEWPOINT OF MARINE INSURANCE 45
Nevertheless, eventually Congress passed Public Law
91-224, entitled the "Water Quality Improvement Act of
1970". Section 11 of the Act is entitled "Control of
Pollution by Oil". Much of this section properly deals with
such aspects of the problem as requiring the reporting of
discharges of oil (Section 11 (b)(4)), civil penalties for
knowingly discharging oil (Section 11 (bX5)), and the
establishment of a National Contingency Plan for removal
of oil (Section 11 (cX2)). The act also makes clear (Section
11 (cXl)), that the President of the United States is
"authorized to act ot remove or arrange for the removal of
such oil at any time, unless he determines such removal will
be done properly by the owner or operator of the vessel,
onshore facility, or offshore facility from which the
discharge occurs". It further makes clear (Section 11 (d) &
(e)) that whenever there are substantial or imminent threats
of pollution hazards the President of the United States has
authority to act. While it is my opinion that much of this
section of the act was unnecessary because such powers of
the Federal Government are already vested in the
President of the United States, nevertheless I cannot
criticize these aspects of the law if there was any doubt as
to such powers or any lack of clarity with respect to the
extent of these powers. In any event, there has been no
objection by the maritime community to these sections and
they can properly be said to come within the title of the
section, "Control of Pollution By Oil."
The same can be said for Section 11 Q)(0 which
entitles the President to "issue regulations consistent with
maritime safety and with marine navigation laws (A)
establishing methods and procedures for removal of
discharged oil, (B) establishing criteria for the development
and implementation of local and regional oil removal
contingency plans, (C) establishing procedures, methods,
and requirements for equipment to prevent discharges of oil
from vessels and from onshore facility and offshore facility,
and (D) governing the inspection of vessels carrying cargoes
of oil and the inspection of such cargoes in order to reduce
the likelihood of discharges of oil from such vessels in
violation of this section. All of this can really result in
"Water Quality Improvement"-the title of P.L. 91-224.
The same cannot logically be said to be true of Section
11 (0(0, which changed the basis for liability of vessel
owners to the United States Government from negligence
to absolute liability "except where an owner or operator
can prove that a discharge was caused solely by (A) an Act
of God, (B) Act of War, (C) negligence on the part of the
United States Government, or (D) an act or omission of a
third-party without regard to whether any such act or
omission was or was not negligent", and established a
separate limitation fund for the benefit of the United States
Government "in an amount not to exceed one hundred
dollars per gross ton of such vessel or fourteen million
dollars, whichever is larger, except that where the United
States can show that such discharge was the result of willful
negligence or willful misconduct within the privity or
knowledgeof the owner, such owner or operator shall be
liable to the United States Government for the full amount
of such costs." Section 11 (g) is similar with respect to the
liability of third-parties and Section 11 (pXO,(2)& (3)
requires that all vessels and barges over 300 gross tons using
any port or place in the United States or the navigable
waters of the United States give evidence of financial
responsibility to meet the obligations imposed by the act
and provide that the United States may bring a direct
action against an insurer who gives such evidence of
financial responsibility. During the extensive and protracted
hearings which were held in the two years prior to the
enactment of P.L. 91-224, it was pointed out by witnesses
from the maritime industry, and especially by Mr. Peter N.
Miller and Mr. John C.J. Shearer of London, England,
representing the London Group of Protection and
Indemnity Associations, that the capacity of the insurance
market to cover the risks imposed by this legislation was
limited and that too stringent legislation would be
self-defeating in that vessel owners would be unable to
obtain adequate insurance coverage. It was also pointed out
that there was no real need for requiring evidence of
financial responsibility since there had never been an
incident where there had been refusal to pay legitimate
claims under existing law where liability had been
established on the part of the vessel. Furthermore, there
is generally no need for such requirements when the
incident occurs within the territorial waters of the United
States since the types of spills which Section 11 of Public
Law 91-224 is designed to cover result from extremely
serious accidents which would never escape public notice.
Despite the general unhappiness in the maritime
community with those aspects of Public Law 91-224 which
deal with liability for accidental oil spills (as distinguished
from those aspects of the bill dealing with control of
sewage from vessels and other areas of a more technical
nature, to which there had been no objection) it has been
found that the liability imposed by the statute could be
insured and the evidence of financial responsibility to meet
the liabilities imposed by the statute has been furnished to
the federal Maritime Commission. However, the cost and
inconvenience to the industry and to the United States
Government of administering the financial responsibility
sections has been immense. See the article in "Seatrade" for
March 1971 at page 49 entitled "Legislation Which Could
Make Pollution Risks Uninsurable" by Malcolm Bennett.
He states that without the evidence given by the Protection
and Indemnity Associations before the Congressional
committees "the American Act (P.L. 91-224) would have
been much more punitive and, probably, unworkable."
Section 11 (o)(2) of Public Law 91-224 provides that
"nothing in this section shall be construed as preempting
any State or political sub-division thereof from imposing
any requirement or liability with respect to the discharge of
oil into any waters within such State." This provision has
been, in my view, wrongfully construed ^to open the way
for many coastal states to enact legislation which purports
to impose additional liabilities on the part of vessel owners
for accidental oil spills over and beyond those already
imposed by Public Law 91-224. Such legislation-which I
regard as unconstitutional—has been enacted in Washington,
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46 LAWS AND ENFORCEMENT
Maine, Michigan, Massachusetts and Florida, among others.
The result has been utter chaos. For example, the Florida
statute, which imposes absolute liability without limit to
the State of Florida for clean-up costs and to Florida
residents for damages resulting from accidental oil spills,
also requires that vessels trading to Florida provide evidence
of financial responsibility to meet the obligations imposed
by that statute. For most vessels this means evidence of
insurance—but the insurers already extended themselves as
far as they can to provide such evidence to the Federal
Maritime Commission and they have stated that they cannot
give evidence to the various coastal states. (See Figure 1).
I submit that this flurry of activity with respect to
legislation is not well thought out and that it is politically
motivated rather than being directed to actual solution of
problems. As stated by Mr. Edgar Paulson at the Hazardous
Polluting Substances Symposium held by the Department
of Transportation, United States Coast Guard, in New
Orleans on September 14-16, 1970 "some politicians have
discovered pollution as McCarthy discovered communism.
Decisions about water pollution are based upon political
consideration rather than the greatest good for the greatest
number" (Abstract of Proceedings, VII-17).
2. Enforcement of Existing Legislation
While no legislation regarding liabilities for accidental
oil spills resulting from groundings and collisions can
prevent such incidents—no navigator wants to have a
collision or to ground his vessel—enforcement of existing
legislation concerning operational spills can be effective in
reducing pollution of our waters. It has already been found
that one of the best vehicles for stopping such operational
spills is the Refuse Act of 1899,33 U.S.C J§406-407. Other
such Federal legislation is the Oil Pollution Act of 1924 as
amended (33 U.S.C.S433 et seq.) and the New York Harbor
Act of 1886. For discussion of this legislation and the
general problem of control of oil pollution on navigable
waters see Sweeney, Oil Pollution of the Oceans, 37 Ford-
ham Law Review 155 (1968). Also see Lohne, Oil Pollution
of Coastal and Inland Waterways of the United States Under
the Water Quality Improvement Act of 1970,38 Insurance
Counsel Journal 49 (January 1971). The problem of
operational oil spills resulting from tank cleaning operations
at sea is covered by the International Convention for the
Prevention of Pollution of the Sea By Oil and the Oil
Pollution Act of 1961, 33 UJS.C.i§1001-15. See Healy &
Paulsen, Marine Oil Pollution and the Water Quality
Improvement Act of 1970,1 J. Mar. Law & C. 537, especial-
ly pages 539-40.
However, enforcement of any legislation requires
appropriations—and this has never been a popular subject
with politicians. I submit that uniform and rigid
enforcement of legislation concerning operational oil spills
will do far more to clean-up the navigable waters of the
United States than will any new legislation concerning civil
liabilities for spills which were accidental and which
resulted from good faith errors of judgment in moments of
crisis. The cost of such enforcement is of course heavy, but
the results can readily be seen if the enforcement is
effective. The popular writer on financial problems, Miss
Sylvia Porter wrote in her column for September 23, 1970
on the subject "What Price Clean?"
Miss Porter wrote:
"/ read with interest your column, Sylvia, stating
that it's the U.S. consumer who will pay for the
control of pollution. You are right. There will
inevitably be either higher prices to the customer for
most products, or there will be a big dent made in the
private enterprise, profit motivated economy we have
in this country, with serious repercussions on the
value of equities, etc., etc."
Okay, Bob-a friend, and the president of a
world-famous chemical company-has zeroed in on a
basic question.
Are you a consumer, prepared to pay for the
staggering costs of not only cleaning up today's
environmental mess, but also preventing further air,
water and other types of pollution?
Are you, a consumer, prepared to support the
measures the company in which you own stock takes
to prevent or combat pollution-if the measures mean
costs which bite into profits?
Are you, as a taxpayer, ready to pay
anti-pollution taxes and to bear the costs of more and
more bond issues in your community to raise bigger
and bigger sums of money for pollution controls?
YOU HA VE to pay for them, you know, in one
guise or another. There is no one else but YOU to pay
for them. NO ONE.
Pollution is unmistakably, undeniably on your
mind.
More than seven in ten Americans say they are
worried about environmental pollution; a recent
Gallup poll disclosed that 10 per cent of a
cross-section of Americans now consider pollution
one of the most important problems facing the
nation, vs. only 2 per cent in June; some observers go
so far as to say this single issue of cleaning our air and
water will close the generation, racial and affluence
gaps.
But are you prepared to put your money where
your mouth is?
Tragically, the probability is that you are NOT.
Item: In a recent public opinion poll Americans
were asked whether they would pay $15 more in
federal taxes to finance a meaningful pollution
control program. By two to one, younger Americans
vowed that they would, but by two to one those in
the over-50 bracket opposed the tax. By two to one,
the better educated were for the tax, but by two to
one the less educated were against it. Only $15!
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LAWS AND ENFORCEMENT 47
And this is just the beginning of conflict. The
evidence points clearly to a real showdown in the
1970s between the business-as-usual segment of our
population which looks upon pollution as a price we
just have to pay for our material affluence and the
younger environmentalists who insist that factories
must close if they cannot meet rigid standards.
Item: Local taxpayers the nation over are voting
down a record number of bond issues proposed to
raise funds not only for schools but also for pollution
controls. And even the sums being refused are utterly
inadequate to meet most local needs.
Item: Federal income taxpayers are battling-via
their Representatives and Senators in
Washington—even the paltry sums being debated by
Congress to fight pollution. Total federal spending for
pollution control now amounts to only about $1
billion a year, and the typical $10,000-a-year city
taxpayer's annual federal tax bill for pollution
abatement is estimated at only $4-against $26 a year
for federal highway construction.
Item: Motorists are shunning the slightly more
expensive lead-free and low-lead gasolines now being
sold.
But the fact remains. As another reader, Kerry
W. Mulligan, chairman of California's Water
Resources Control Board wrote me: "People will have
to come to grips with the fact that environmental
protection costs money. To search for 'cheap'
solutions will be the most expensive step in the long
run. The basic choice is between short-term
correction of pollution and long-term environmental
protection."
Which will YOU choose?
She poses the question "Are you, a consumer, prepared
to pay for the staggering costs of not only cleaning up
today's environmental mess, but also preventing further air,
water and other types of pollution". She comments, "YOU
HAVE to pay for them, you know, in one quise or another.
These is no one else but YOU to pay for them. NO ONE." I
submit that the public, if given a clear picture of the
problem-and here I am more optimistic than is Miss
Porter-will be willing to pay for preventing further
pollution of our waters, but that the public will not be
willing to bear the cost of new legislation which is
unnecessary, irrelevant and does not result in prevention of
pollution.
CONCLUSION
It is my conclusion based on the experience which I
have had in representing Protection and Indemnity
Associations, in attending at legislative and other hearings
concerning proposed laws in the area of control of
pollution from vessels, and as a taxpayer and as an avowed
conservationist that:
1. While major casualties such as the Torrey
Canyon grounding are more dramatic, the principal
sources of oil pollution of navigable waters are the
compound effect of many relatively minor
operational spills which can be controlled by better
technology and uniform enforcement of existing
laws.
2. That major casualties such as the Torrey
Canyon grounding will not be prevented by
legislation imposing absolute liability and uninsurable
limits—that the principal deterrent to such casualties
is the risk to the lives and careers of the navigators
themselves which result from their in extremis errors
in judgment and that navigators do their utmost to
avoid such incidents. Again, the solution is better
technology.
3. That the cost of transportation of
commodities which the public wants and demands
will be increased by reason of the types of legislation
now being proposed and discussed without any
commensurate benefit whatsoever to the public.
4. That the most appropriate type of legislation
covering liability for oil spills from ocean-going
vessels is an Internation Convention. Even though a
proposed convention may not be perfect, the
essential requirement of uniformity would outweigh
any disadvantages of such a convention (e.g., the
1969 Brussels Convention concerning civil liability
for oil pollution and the powers of governments to
act.) In any event, legislation by individual states and
municipalities in addition to that of the Federal
Government is not only unconstitutional but also
impractical and self defeating.
5. That appropriations of money to provide for
enforcement of existing laws with respect to
operational oil spills and to provide for improved
technology in connection with transportation,
loading and discharging of oil and other hazardous
substances and clean-up procedures when spills
nevertheless occur will give the public its money's
worth, as well as making clear to the public that there
is no way to avoid the cost of ecological progress.
Finally —don't be afraid of the word "discrimination".
Not everything that is done in the name .of ecological
progress will clean up the environment. Separate the wheat
from the chaff. Discriminate between legislation which
merely improves a politican's image and that which also
does the essential job of cleaning up the environment. And
make sure that you get something of value for your
money—since it is you who will be paying for it in any
event.
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48 THE VIEWPOINT OF MARINE INSURANCE
THE WEST OF ENGLAND SHIP OWNERS
MUTUAL PROTECTION & INDEMNITY ASSOCIATION (LUXEMBOURG)
(INCORPORATED IN LUXEMBOURG)
THE WEST OF ENGLAND SHIP
OWNERS MUTUAL INSURANCE
ASSOCIATION (LONDON) LTD.
1 LLOYDS AVENUE.
LONDON. EC3N 3DN
TELEPHONE OI-4BO 7*72
TELEX WESTENG LONDON «aaO2»
TILCOIIAMS • CABLES
WESTENO. LONDON
Ref 71 M
To All Members
22nd February. 1971
OIL POLLUTION —FLORIDA
We refer to our Circular of December. 1970 covering legislation in Massachusetts. We
have now been informed that the State of Florida has issued regulations, the full terms of
which are as follows :—
"(1) No vessel or barge, carrying oil of any kind and in any form, gasoline, pesticides.
ammonia, chlorine, or other hazardous materials as cargo, shall use any port in Florida
on or after 1st March. 1971. for any purpose unless a Certificate of Financial Responsi
bility has been issued by the Department covering such vessel or barge.
(2) Either Owners or Operators of vessels or barges subject to Chapter 70-244. Laws
of Florida, must establish and maintain with the Department evidence of financial
responsibility in an amount not to exceed $100 per gross ton of such vessel or
$5.000.000 whichever is lesser. Provided, however, that if an applicant is the Owner
of more than one vessel or barge subject to this rule, financial responsibility need
only be established in an amount necessary to meet the maximum amount of financial
responsibility to which the largest vessel or barge could be subjected hereunder.
Nothing herein shall be construed to prohibit third parties from establishing evidence
of financial responsibility for such Owners or Operators of vessels or barges.
(3) The financial responsibility herein required may be established and maintained
by any one (1) of. or a combination of the-following methods acceptable- to the
Department :
(A) Evidence of Insurance—conditioned to pay all costs and expenses of the clean
up of any discharge as well as damages caused to the State and any other person.
(B) Surety Bonds payable to the Governor of the State conditioned to pay all costs
and expenses of the clean-up of any discharge as well as damages caused to the
State and any other person.
(C) Qualification as a self insurer, or
(D) Other evidence of financial responsibility satisfactory to the Department
(4) All applications, evidence, documents, and other statements required to be filed
with the Department shall be in English, and any monetary terms shall be expressed in
terms of United States currency. Such evidence of financial responsibility shall be
on forms furnished by the Department upon request of the Applicant.
f5) Where evidence of financial responsibility has been established, a separate Cer
tificatc covering each vessel shall be issued evidencing the Department's finding of
adequate financial responsibility to meet the minimum requirements of this Rule."
As we warned Members in the Massachusetts Circular referred to above, the under
signed Associations will not be able to issue separate Certificates for Florida.
We particularly draw your attention to the fact that these regulations come into force
on the 1st March. 197:
Yours faithfully
Assuranceforeningen Card
Assuranceforeningen Skuld
Newcastle Protection & Indemnity Association
Sunderland Steam Ship Protecting & Indemnity Association
Sveriges Angfartygs Assurans Forening
The London Steam-Ship Owners' Mutual Insurance Association Limited
The North of England Protecting & Indemnity Association Limited
The Standard Steamship Owners' Protection & Indemnity Association Limited
The Standard Steamship Owners' Protection and Indemnity Association (Bermuda) Lfi
United Kingdom Mutual Steam Ship Assurance Association (Bermuda) Limited
The West of England Ship Owners Mutual Protection and Indemnity Associatior
(Luxembourg)
Figure ].
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SHOULD FINANCIAL LIMITATIONS UPON
LIABILITY BE APPLIED TO OIL SPILL
REMOVAL AND DAMAGE
C. R. Hdlberg
Maritime International Law Division
United States Coast Guard
ABSTRACT
The title of this paper might lead the uninformed to the
conclusion that the question is yet to be resolved. To the
more knowledgeable it might appear to be a discussion as to
the merits of locking the bam long after the horse had been
stolen. While several august bodies, including the Congress
and the 1969 Brussels International Conference on Marine
Pollution Damages have concluded that there should be, at
least in certain cases, a financial limitation upon liability for
damages resulting from oil spills, the issue is far from dead.
The purpose of this paper is to raise the question as to
whether financial limitation schemes are the best solution
to the problem of cost distribution with regard to damage
caused by oil.
INTRODUCTION
In the old common law, as it existed before James Watt
and John MacAdam and the rest of the succeeding host of
persistent mechanics upset the status quo, the basic idea,
when someone had been injured or damaged, was to make
that person as whole again as possible. The focus of
attention and concern seemed to be upon the victim, and
within the capabilities of his purse, he who had done the
injury had to pay up. This is not going to be an historical
treatise on the good old common law and in the interests of
brevity the foregoing statement is something of a general-
ization, and subject to the infirmities attendant upon broad
statements. However it is necessary to look, albeit quickly,
at the antecedents of our body of laws in order to
comprehend, even minimally, just how we arrived at our
present sorry situation.
But, laying aside all of the complicating side issues, in
the good old days the basic limitation upon the tortfeasor's
liability to pay for damages was the size of his fortune. This
resulted, of course, in a certain amount of injustice to the
injured party who was not fortunate enough to be injured
by a financially sound tortfeasor. However the law, as a
Philadelphia lawyer once observed, is not the road to the
millenium but simply a means to keep the peace. The idea
of spreading the cost of the damage beyond the parties to
the transaction did not flourish in the common law.
With the advent of the steam engine and the modern
paved road, the opportunities for people damaging and
injuring one another increased almost as rapidly as the
opportunity to make vast sums of money did. Paying out
the large sums of cash to workmen injured in industrial
accidents, to pedestrians trampled by the speedy post
coaches and other such victims c-f what the school teachers
choose to call the Industrial Revolution put unpleasant
dents in the profit columns of the burgeoning new
industries. What with the frailties of their machinery, their
unsophisticated financing structure and the mysteries of the
marketing mechanism, there was little question but that
these industries needed help. The problem of government
was how to give this help—preferably at the least out-of-
pocket cost to the government. One of the many devices
that came to be employed was that formulated by the
fearless common law judges who created a whole new
concept of tort liability for these infant industries whereby
the injured parties themselves were made to foot the bill.
This approach also had the happy advantage of not costing
the government money. At least not then. The idea of
wrong doing in the moral sense was refurbished and trotted
out to limit the cases of recovery. This was further
bolstered by the creation of the doctrines of contributory
negligence, assumption of risk and other quasi-moralistic
means of transferring the costs of damage or injury from
the back of industry onto what the international lawyers—
with wry humor—have come to call the innocent victims.
Turning from the lawyer's perspective of the matter to
the economist's, the practical effect of these doctrines was
49
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50
LAWS AND ENFORCEMENT
to create a form of inverse subsidy, or better, it external-
ized some of the costs of doing business. This may be taken
to mean that the price of the product or service involved
did not reflect all of the costs of production. When one is
attempting to foster new industry somebody has to foot
the bill. To the extent that the specific beneficiaries do not
do so by reason of cost externalization, the so-called
general beneficiaries—the taxpayers, the public at large-
pay. Some form of taxation is usually required to make a
roughly equalized distribution of these costs. This has the
saving grace of fairness. However when these costs are
distributed solely amongst an irrationally selected group,
such as the corps d'elete of innocent victims, the element
of fairness seems to vanish.
It is necessary to observe that as industry developed
from its tottering infancy, reaction set in against what had
become unnecessary advantages and the ponderous legal
pendulum began to swing back toward the side of the
innocent victim. The various workmen's compensation
schemes are exempletive of the new devices which were
developed to ameliorate or eliminate the harshness of the
legal rules of tort liability. These mechanisms also had the
happy effect—from the economists point of view-of
internalizing the costs. The pendulum is still swinging, as
evidenced by the recent interest in no-fault automobile
insurance laws.
There were, of course, many other devices created to
limit liability of which the most important was the limited
liability company or corporation. Another was a statutorily
stated financial limitation upon liability. Both of these
concepts were designed to foster the growth of commerce
by the expediency of modifying the terms of contracts.
For reasons of public policy, it was important that
travellers had a place to stay and merchants a reasonably
reliable way to ship goods. Innkeepers and common carriers
were not overly enthused with the prospects on the one
hand of having to accept just about anybody or any cargo
that came along and on the other of having a high duty of
care imposed upon them. Since this was a reasonable
emotion, the solution was to either let them be choosey as
to their clients or limit their liability in some fashion. The
latter course prevailed and to this day, financial limitations
upon the liability of innkeepers and common carriers and
others of their general ilk are common. This does not
distress the economists since the costs of the service or
product remain internalized. Both parties to the contract
know where they stand beforehand and can take due
precautions. Cargo shippers will insure their cargoes and the
costs of the premiums will be reflected in the price to the
consumer. A parallel situation exists when one does
business with a limited liability company.
However it is important to note that the financial
limitation upon the liability of a common carrier applies
only to the relationship between the shipper and his cargo,
except in the maritime field-of which there will be more
later. If the common carrier's truck should run down a
pedestrian, the financial limitation upon liability is not
applicable. The parallel between financial limitations upon
liability and the limited liability company diverges at this
point of course. The limitation scheme for companies
applies with great equality to those outside of the contrac-
tual ambit as well as to those within. The judiciary, never
satisfied to leave things alone, has undertaken to set aside
the inequities of the limited liability of a company to an
injured party through a means which has the slightly risque*
label of "piercing the corporate veil." But this attack upon
limitation is really still in its infancy and it will probably be
quite sometime before the ordinary run of the mill
tortfeasee (to carry legal jargon to the brink) can derive any
solid comfort from it.
If industry ashore was in precarious state two hundred
years ago, industry afloat was in that state two thousand
years ago and there still isn't much improvement to write
home about. Freight on the first voyage of a ship in the
days of sail had better cover the capital outlay and
expected profit since the risks were rather enormous, and
hoping for a second successful voyage was not too realistic.
Insurance as we know it was developed for the spreading of
the risks involved in the maritime mercantile ventures. But
this was insufficient and other devices were employed.
Amongst these was the financial limitation upon liability.
This limitation did not apply just to the contractual
arrangements between the vessel and the cargo or passen-
gers, but to all activities of the vessel except where the
vessel owner was privy to whatever nefarious conduct that
resulted in a claim. All that this exception did was to drive
any remaining seagoing ship owners ashore.
As a matter of practical impact upon persons outside of
the contractual ambit, the limitation had litle effect since
nearly every vessel going to sea enjoyed an essentially
identical provision of liability limitation. Thus, when one
vessel collided with another, both were standing on a fairly
equal footing insofar as avoidance of liability was con-
cerned. Furthermore it was rather difficult for a merchant
vessel to damage something outside of the maritime
environment. Costs therefore tended to remain
intemalized-at least when the shipping industry was
viewed as a whole. However, with the advent of bigger
vessels carrying sizeable cargoes of rather hazardous com-
modities, explosives, lethal gases, petroleum, pesticides and
the like, it became fairly easy for a vessel to cause
substantial damage where the hazard had not before
existed. Thus substantial portions of Halifax and Texas City
and South Amboy were hoist by maritime petards (a petard
being an iron pot full of explosives hung on a fort's front
door with a view toward gaining a disputed access to said
fort) and in the latter two cases the innocent victims found
the shipowners claiming their liability extended only to the
value of the vessels after the incident, with the comforting
addition thereto of pending freight, if any. It should be
noted that the corporate veil piercing judiciary is beginning
to take a similar tack in admiralty, hanging an occasional
shipowner on a newly wrought privity hook. This exposi-
tion into the gallery of rat holes that are available routes to
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FINANCIAL LIMITATIONS ...
51
escape payment for damages done would not be complete
without at least cataloging the regimes of so-called absolute
liability, strict liability and ordinary fault liability. Absolute
liability, or the doctrine of extra-hazardous activities, is a
throwback to the good old common law when the state of
your moral fiber, your good or evil intentions, and the
nature of your enterprises was irrelevant and immaterial to
the issue of payment for damages. This doctrine was crept
back to a very limited degree, frequently covering the
movement and handling of explosives, and for a time
covering the new fangled flying machine. Just recently a
few states have resurrected the concept to apply to oil
pollution, to the general horror of prospective polluters and
their underwriters. The doctrine of strict liability is a notch
below absolute liability in its stringency-the tortfeasor is
given a limited number of escape hatches, usually including
acts of God, war and other assorted hostilities, intentional
acts by third parties and possibly a few more of similar ilk.
The doctrine of strict liability is probably best described as
the political compromise between the grim proponents of
absolute liability and the genial exponents of ordinary fault
liability, the creature from the Industrial Revolution.
Financial limitation, corporate limitation, fault limita-
tion and of course purse limitation all exist independently
in the armory of the defendant and can be deployed singly
or in conceit as needs dictate.
With the foregoing as background, the issue of financial
limitation may be viewed in context as simply one of the
available defenses to the payment of what the Brussels
1969 conference termed "full and adequate" compensation
for oil pollution damage.
Brussels Civil Liability Convention and the
Amended Federal Water Pollution Control Act
Both the Brussels Civil Liability Convention and Section
11 of the amended Federal Water Pollution Control Act
impose the strict liability regime—with closely parallel
escape hatches. The Civil Liability Convention applies only
to vessels carrying oil in bulk as cargo while Section 11
covers any installation, vehicle, or device that can spill into
navigable waters except aircraft and structures on the Outer
Continental Shelf. The Civil Liability Convention provides
an exclusive remedy for the damages to any party-govern-
mental or private—while Section 11 is limited to the Federal
government's removal costs, leaving the government's other
damages (such as in its proprietary capacity) and the
damages of all other innocent victims to their remedies
under State or Federal law. Both the Civil Liability
Convention and Section 11 with respect to vessels have a
very similar financial limitation—in the former about $135
a convention ton (smaller than gross, bigger than net) up to
a ceiling of $14 million, in the latter $ 100 a gross ton up to
the same $14 million. Section 11 further imposes an $8
million limitation on the liability of installations other than
vessels (with provision for a reduction in the case of small
and deserving facilities). When one dwells on the money
available from vessels it is well to remember that very few
ships are of sufficient size to reach the magic $14 million
figure. A good sized oil barge will gross around 2000 to
2500 tons which translates into a limitation figure of about
$250,000. A small tank farm ashore of comparable oil
capacity has a limitation figure of $8,000,000. How's that
for equity amongst prospective polluters?
It is, of course, relatively useless to discuss financial
limitation schemes without reference to how high they are
in relationship to the anticipated damages. If the ceiling is
truly high enough, then there is no real impact upon the
innocent victim whose damages fall below the limitation
figure and he cannot complain about the law on that score.
But one has to watch out for the meaning of the term
"damages," particularly in the pollution area. Section 11
clearly attempts to define "removal" costs (removal proba-
bly comprehends more than the commonly used phrase
"clean-up") in a manner to obviate the necessity of proving
"damages" in its commonly accepted (by lawyers) sense.
The Civil Liability Convention tries to do the same thing,
but less blatantly, and possibly less effectively. The
practical impact is to jack up considerably the amount of
the claim that can be asserted, which of course then affects
the assessment as to whether the limitation figure is high
enough. From the available statistics that have been
gathered, the only thing that can be perceived with clarity
is that no one really knows how much an oil spill can cost.
Equally no one knows how much real damage (as opposed
to legal damage) oil can do and for that matter just who is
entitled to claim injury (plants, animals and fish have no
standing in their own right, which is very convenient for
us). Thus the participants at the Brussels 1969 conference,
although they agreed on the $135/ton limitation figure,
retained sufficient doubts about the adequacy of that
amount to commission the elaboration of still another
Convention on oil pollution damage in order to raise the
effective ceiling on recovery for the innocent victims to a
figure of at least $30 million per incident.
While $8 million looks like a pretty high limitation
figure for onshore and offshore facilities, it is not beyond
the realm of reason to postulate a case where the costs
might exceed that amount-the forced interruption of a
major city's water supply might suffice. But in the same
situation where a vessel causes the incident, the Section 11
figure of $100/gross ton leaves the author at least with an
uneasy feeling. The feeling is heightened when the other
damages (e.g. other than Federal removal costs) are consid-
ered in the light of the vessel's remaining limitation
defense-its value after the incident, plus freight. This
defense incidentally (though there is nothing incidental
about it) is available even though suit is brought under a
State statute which, say, imposes unlimited and absolute
liability for oil pollution damage.
At this point two questions (at least) appear to require
an answer. Why was a financial limitation of liability
included in the Civil Liability Convention and in Section 11
of the FWPCA? How were the limitation figures deter-
mined?
-------
52 LAWS AND ENFORCEMENT
The published answers are contained in the records of
the hearings and deliberations on the subject and are, if
nothing else quite voluminous. The gist would appear to be
that producers and transporters of oil prefer to spread the
costs of the risk of pollution incidents through the medium
of insurance. The word "prefer" in point of fact hardly
describes the emotion involved. They view the availability
of insurance coverage—at a premium they can afford to
pay—as a necessity of economic life. Underwriters—equally
concerned with the necessity of the good economic life-do
not write policies for liability in unlimited amounts. It
follows then that if insurance is obtainable only in
determinable amounts, liability should be limited to such
an amount. The strength of this argument quite evidently
carried the day in both arenas and I leave it to the
proponents to elaborate thereupon. However, using a rather
common example, that of an automobile collision, it could
be observed that the tortfeasor's liability is unlimited—in
the sense of a financial limitation scheme—even though he
cannot obtain insurance coverage in an unlimited amount.
Carrying the argument forward then, all tort liability in the
United States should then have a limitation ceiling. But the
economists will then point out that where the damages
exceed the limitation figure, the costs of the product,
service or activity will be externalized and will be borne, in
an irrational distribution, by our corps d'elite of innocent
victims.
The answer to the second question is harden to pin
down. Within the determinable amounts of insurance
coverage, the degree of exposure has a great deal to do with
the premium charged on the one hand and the amount of
risk capital available in the insurance market. In the case of
oil pollution damage by vessels where the contemplated
liability regime was to be that of strict liability, and where
the knowledge as to what these damages would total up to
be was so sparse and uncertain, it seemed to work out that
the available insurance risk capital in the world's underwrit-
ing markets would top out the limitation figures which are
incorporated in the convention and the legislation. In short,
while there was ample capital available if the ordinary fault
regime was applied, there was precious little money
attracted to cover the strict liability regime even with a
financial limitation ceiling. The iconoclastic observation
was made by some that the aircraft industry—which has no
financial limitation ceiling for so-called third party dam-
ages—was not having difficulty in locating enough insurance
risk capital.
From the viewpoint of the concerned industries, the
national and international legislation on oil pollution
damage has or will impose a very heavy burden, and a
financial limitation upon their liabilities is an essential
element in their ability to continue to do business. From
the dispassionate viewpoint of the economist the equitable
(in the economic rather than legal sense) approach is to
internalize all of the costs of the product or service,
including the costs of pollution prevention and pollution
damage. Financial limitation schemes, and for that matter,
all of the other means of liability avoidance or limitation,
tends to defeat the goal of internalization. They argue that
only when the consumer is paying the full bill can he make
an intelligent choice in the market place. Products costly in
the pollution sense would tend to fail of selection in
competition with products less costly, other factors being
equal.
"INNVIC"
Lastly, the viewpoint of the innocent victim should be
considered. In this age of abbreviations and acronyms it
would probably be stylish to refer to him as the INNVIC.
When old.INNVIC finds himself on the receiving end of an
unwanted load of liberated hydrocarbons which fouls his
beach or water supply or otherwise disturbs his tranquil
enjoyment of what is left of the environment, he will
predictably react by demanding that the mess be cleaned
up—fault being sort of meaningless—and further that he be
fully compensated for his injuries, preferably to the extent
that his balance sheet shows a bit of untaxable profit as
well. What do you suppose is his opinion of the justice,
equity and propriety of a law that limits his recovery to
something less than the chimerical full and adequate
compensation? Does he bear with equanimity the concept
of inverse irrationally distributed subsidy? Does he glory in
assuming, quite involuntarily, a disproportionate share of
the costs of petroleum production, distribution and con-
sumption? Or does he, perhaps, share the views of the
unfortunate owner of a defective automobile that has been
repossessed who has just become apprised of the full
meaning of the phrase holder-in-due course?
-------
THE MAINE LAW-A PRECURSOR FOR
THE OIL TERAAINALING STATES
William R. Adams
Environmental Improvement Commission
State of Maine
INTRODUCTION
Long before TORREY CANYON, and as early as
November of 1963, when the Liberian tank ship NORTH-
ERN GULF ran aground in West Cod Ledge, off Casco
Bay, Maine, spilling 21,309 barrels of a light crude oil along
the rocky coast of Maine, causing untold devastation to the
shoreline and aquatic ecology, the concerned citizenry of
our State became acutely aware of the hazards involved in
transporting oil and oily products upon the clear, cold,
coastal waters of countless miles of our coast. This massive
spill stirred the dander of the yankee fishermen, the boat
owners, and the property owners and prodded them into a
concerted effort to increase clean up programs and seek
stronger enforcement by the regulatory bodies. Numerous
small suits evolved as a result of this oil spill and only as
recently as last year was the final civil suit settled. The
lobstermen and fishermen claimed irreparable damage to
their catches. Shore property owners were unable to cope
with the spill; clean-up agencies did not exist; the state of
art for clean up was crude, at best. The clean up panacea in
those years consisted of dumping large quantities of
dispersants on the water to seemingly make the black ugly
oil dissolve and disappear. The philosophy of, "Out of
sight, out of mind" prevailed, resulting in the dumping of
untold numbers of barrels of toxic chemical emulsifying
agents on the spill.
We have progressed considerably since those days.
International attention was focused on much greater spills.
TORREY CANYON and OCEAN EAGLE became house-
hold words. The anti-pollution tempo approached its
zenith. Research and development programs were under-
taken on the campus, in the laboratories, as well as in the
basements of citizens who were simply concerned with
coping with the problems of oil.
All during these years the attitude and determination of
the Maine Legislature was taking shape. People were talking
to their Legislators. The blast of the danger whistle
resounded in the newspapers, editorials, magazines, and
television. The sleeping giant, the public, had awakened. A
new course was being set.
A New Law on the Horizon
The First Special Session of the 104th Legislature
foresaw the need for strong Legislation. The Legislative
hands at the helm of the State drafted the strong
Legislation needed for the task ahead. They declared by
preamble to the proposed law, "that the highest and best
uses of the seacoast of the State are as a source of public
and private recreation and solace from the pressures of an
industrialized society, and as a source of public use and
private commerce in fishing, lobstering and gathering other
marine life used and useful in food production and other
commercial activities". The Legislature found "that preser-
vation of these uses is a matter of the highest urgency and
priority and that such uses can only be served effectively by
maintaining the coastal waters, estuaries, tidal flats, beaches
and public lands adjoining the seacoast in as close to a
pristine condition as possible taking into account multiple
use accommodations necessary to provide the broadest
possible promotion of public and private interests with the
least possible conflicts in such diverse uses. The transfer of
oil, petroleum products and their by-products between
vessels within the jurisdiction of the State and State waters
is a hazardous undertaking; that spills, discharges and
escape of oil, petroleum products and their by-products
occurring as a result of procedures involved in the transfer
and storage of such products pose threats of great danger
and damage to the marine, estuarine and adjacent terrestrial
environment of the State; to owners and users of shore front
property; to public and private recreation; to citizens of the
53
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54 LAWS AND ENFORCEMENT
State and of her interests deriving livelihood from marine-
related activities; and to the beauty of the Maine coast; that
such hazards have frequently occurred in the past; are
occurring now and present future threats of potentially
catastrophic proportions, all of which are expressly de-
clared to be inimical to the paramount interests of the State
as set forth and that such State interests outweigh any
economic burdens imposed by the Legislature upon those
engaged in transferring oil, petroleum products and their
by-products and related activities."
Police powers of the State were given to the Environ-
mental Improvement Commission. The Commission re-
ceived "power to deal.with the hazards and threats of
danger and damage posed by such transfers and related
activities; to require the prompt containment and removal
of pollution occasioned thereby; to provide procedures
whereby persons suffering damage from such occurrences
may be promptly made whole, and to establish a fund to
provide for the inspection and supervision of such activities
and guarantee the prompt payment of reasonable damage
claims resulting therefrom."
The Law—More Than a Paper Promise
The law provides for the following:
1. Prohibition of the corruption of waters and lands
adjoining the seacoast of the State.
2. Grants the Environmental Improvement Commission
the exercise of police powers and duties to implement the
law.
a. Extends jurisdictional powers and duties out to a
distance of 12 miles from the coastline of the State.
b. Provides for the issuance of licenses.
3. Establishes procedures for adopting regular and emer-
gency rules and regulations.
4. Authorizes the Governor to declare, by proclamation,
an emergency whenever any disaster or catastrophe exists
or appears imminent within the State arising from the
discharge of oil or oil products.
5. Requires the immediate undertaking of removal of
the spill by the perpetrator.
a. Removal must meet the Commission's satisfaction.
b. The Commission may undertake the removal of the
discharge or retain agents and contracts for such purposes.
c. Authorizes for the removal of any unexplained or
"mystery spill" within State waters.
6. Provides for the establishment and maintenance of
adequate employees and equipment at strategic locations
within the State to carry out the provisions of the law.
7. Creates the Maine Coastal Fund as a nonlapsing,
revolving fund of four million dollars. These monies to be
used for administration of the law, research and develop-
ment for thud party damages.
a. Sets a license fee of 1/2 cent per barrel for all oil and
oil products transferred on Maine waters.
8. Places the onus of liability on the licensee for all acts
and omissions from the moment his carrier (vessel) enters
and until departure from State waters.
Action of the Oil Industry
Initially, the oil industry did not object to our new law;
their real concern was over the liability provisions and the
1/2 cent per barrel license fee for petroleum product
transferred upon Maine waters. On May 10th, one day after
the law became effective, ten large oil companies and an oil
pipeline company brought about companion suits in a State
Superior Court against the Environmental Improvement
Commission to have the law declared unconstitutional. It
alleged, among other things, that the law violated or was
contrary to:
1. The Import-Export clause of the constitution
2. The Commerce clause
3. The Admiralty clause
4. The Due Process clause
5. The equal Protection clause, and
6. Raised similar objections based upon the State of
Maine constitution including deprivation of right to a trial
by jury.
The oil companies managed to obtain a preliminary
injunction against the Environmental Improvement Com-
mission, pending the outcome of the suit. Essentially the
injunction allows the oil companies involved in the suit to
pay monthly license fees to the Court, which is holding
these amounts in escrow, pending the final outcome of the
suit. For parties not involved in the suit, the Environmental
Improvement Commission has voluntarily set up an escrow
fund. This injunction does not preclude the Environmental
Improvement Commission from otherwise enforcing the
law.
The Present Situation
Comprehensive and meaningful oil discharge prevention
and pollution control regulations were drafted and adopted
on December 11, 1970 to become effective December 26,
1970. These regulations fulfill and supplement the meaning
of the law. They are, what we consider, minimal uniform
safety requirements for the oil handling facilities of Maine.
The thrust of responsibility is directly placed upon the
terminal operator.
The regulations require the establishment of such mat-
ters as a pre-transfer conference to insure for the proper
and safe loading/off-loading of oil cargo. To name just a
few, they delineate safe transfer procedures from vessel to
shore and vice versa; they allow for the transfer of vessel to
vessel within designated safe anchorage areas; they require
the taking of samples, and periodic inspection about the
vessel while transferring cargo.
Additionally, they require the establishment of local
contingency plans for each terminal; they require 12 hour
advance notice of any transfer; periodic and final reporting
of all spills and clean-up; and require fire fighting equip-
ment, which surprisingly as it may seem, many terminals do
not have, and finally the prohibition of dispersants is
provided for.
-------
THE MAINE LAW
55
All of the terminal regulations are safety oriented and
are designed to benefit not only the terminal operator but
also the people of Maine. Hopefully, they will bear fruit as
will be evidenced in the months that lie ahead.
Staff and Money—The Common Cry
At present our Bureau of Oil Pollution Control is
understaffed and underfunded. Our entire staff for this
program consists of two personnel, both of whom are
financially supported from the State's general fund. A plea
to the present Legislature for additional personnel and
funding has been made and favorably received. The
additional personnel are needed on location at the oil
transferring activities.
With the limited funds and personnel available, we are
continuing to enforce the tenets of the law. More important
than the regulating and enforcing of the spirit of the law,
we feel that we have developed a communication with the
entire oil industry. Greater feed back and cooperation is a
result. This is not exactly a new tack; but the change of
course is perceptible.
The Future
It is conceivable at this time that the license fees will be
tied up in litigation for a long time into the future.
Nevertheless, we cannot sit back and idly rest on our
laurels and expect the powers given to us by the Legislature
to magically solve our problems. Money is necessary to
actively pursue this aggressive program which has been
placed squarely upon bur shoulders. We plan to continue
our efforts under the stars of this strong regulating law. We
are hopeful that our own Legislature will allocate enough
monies for us to continue and expand our endeavors of
planning, inspecting and regulating the transfer of oil.
Functionally speaking, we recognize that the ships'
masters, the ship owners and operators, the terminal
operators, as well as operating personnel are all under the
pressures of our competitive economic profit-making
system and all too often short cuts are taken to reduce
turn-around time and increase pumping rates. Moreover, we
recognize and have had to face the realization that
self-regulation by the oil industry is not possible. It has
been tried and failed drastically. Stringent control by a
regulatory body seems to be the only answer.
Compliance with our regulations will insure clean waters
in and around terminals, thereby not only improving the
waters but also improving the terminal image to the
community. The "bureaucratic monkey" can always be
placed upon our backs. It is easier for the terminal operator
to go to his company and say, "they require it," rather than
the terminal operator himself requesting safety or abate-
ment equipment. Yes, this State has a lot to offer to the
terminal operator of Maine: Continual safety inspection
programs, closer monitoring of transfer operations by
trained inspectors, dialogue with the oil industry, and
cooperation with other agencies. These appear to be the
best oil dispersant agents known to date. We feel that
through extensive education and rigid safety inspection
programs, together as a team effort with the oil industry,
we can make Maine a leader in the prevention of spills
should a spill occur, contingency plans, stockpiling of
abatement equipment and a sound State organization will
surely aid in the prompt clean up.
The day will come when the nation will be able to look
proudly to our coordinated efforts and statistically show
that spills in Maine will be at the nadar for the nation.
Many states are anxiously watching to see what will happen
in Maine. They are awaiting the results of the litigation and
the formulative preparation that we have undertaken in
anticipation of the future. Perhaps the great American
dream can be realized and once again it will be said that,
"As Maine goes so goes the nation."
-------
STATE JURISDICTION OVER OIL SPILLS
IN A FEDERAL SYSTEM
Daniel Wlkes
Department of Political Science
University of Rhode Island, Kingston, R.I.
ABSTRACT
A comparison of the bases for state and federal juris-
dictions, in the light of Canadian Arctic, Florida, Maine and
Federal Water Pollution Control Acts, shows when, how
and why state and federal officials will find they have over-
lapping jurisdictions. The results of this preliminary study
point to several areas in which the overlaps should be kept
and some key ways in which they may be more rationally
related, especially in preventive measures and contingency
planning.
INTRODUCTION
The passage by states such as Florida and Maine of laws
to deal specifically with oil spills has raised questions about
both the limits and wisdom of state action in a federal
system. The Florida Oil Spill Prevention and Pollution Con-
trol Act took effect on July 1, 1970 and is to be found in
Florida Laws of 1970, chapter 70-244. The Maine "Act
Relating to Coastal Conveyance of Petroleum" was signed
into law by the Governor on February 5, 1970; it added a
new subchapter II-A to Title 38, chapter 3 of the Maine
Revised Statutes called "Oil Discharge Prevention and Pol-
lution Control" in sections 541 to 557. Both acts are sum-
marized and compared with federal laws in the United
States and Canada in the Table of Oil Spill Legislation
under Part II of this study below.
Crux of the Matter of State Laws
and Aims of This Study
The crux of the question of state controls over oil
spills—their prevention, containment, cleanup and reim-
bursements for costs or losses—lies in the fact that certain
functions which each state presently performs make it a
natural unit to handle local problems, while some results of
purely state control just do not fit into rational manage-
ment of the Oil Spill Problem.
For the United States, this study of state powers to
handle oil spills is made at a time in its federated system
when renewed responsibility is being handed to state cap-
itals over most aspects of control over seabed sands and
minerals or fish resources within three miles of shore.
Simultaneously, enforcement of water quality standards for
tidal waters has been made into the state unit's primary
responsibility under national laws.
For example, the Submerged Lands Act of 1953, by
Title 43 of the United States Code, in Section 1311 "con-
firmed . . and vested in" the coastal states "all" resources
within territorial waters or the seabed under them,
including "the right. . to manage them . . in accordance
with applicable state law." For Florida and Texas, The
Supreme Court held in 1960, for historical reasons, that the
federal Congress had intended these two states to get all
natural resources "underlying the Gulf of Mexico" up to 9
miles out.)
This means that
1) spill-producing activities related to state^icensed
oil production offshore, and
2) protection of local oyster beds, lobster grounds,
sport fisheries, trawling waters and the like fall within
state responsibilities.
In short, the state unit has had concern over oil spills thrust
upon it whether it wishes to be concerned or not.
What this study aims to do, therefore, is: first, to set
forth some examples of federal and state laws in the United
States and in Canada for comparison; second, to spell out
the limitations upon state powers under the federal system
57
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58 LAWS AND ENFORCEMENT
in the United States; and third, to present the author's own
views on (a) how both units may cumulatively use their
respective jurisdictions, and (b) which areas are those where
it is wisest to have federal rule-making exclusively, and
those where past patterns of concurrent jurisdiction still
serve a valid purpose.
Application Elsewhere of Lessons from
Jurisdiction in the U.S.
fa a few ways, the United States has special problems
of how much control over oil spills the federal government
can or must leave to state subdivisions. Most of the
problems discussed in this study, however, apply to
questions raised in other coastal nations. For a few
"federal" states, such as Argentina, Australia, Brazil,
Canada, the Federal Republic of Germany, India and Mexi-
co, some of these issues may arise in the future simply out
of the existence of separate governmental units or regions
of authority in oil spill situations.
Most important, however, is the fact that, for all
nations, there are marked similarities between the choices
their governments will have to make in connection with
international regimes for control of pollution and those
choices which states of the United States must make
vis-a-vis their government in Washington, D.C.
COMPARISON OF SAMPLE STATUTORY
OVERLAPS IN POWERS OVER OIL SPILLS
The following Table of Oil Spill Laws affords a means
for comparing the ways in which four governmental units
have set forth, in their specific oil spill law, a few rules on
jurisdictional control and conduct in relation to oil
pollution.
WARNING: It is vital to stress that every one of these
jurisdictions has other laws which apply to spill prevention,
control and liability. Each, for example, has decisional rules
in tort liability, admiralty or reach of its judges in requests
for equitable relief to be found in written court decisions.
Further, this Table has selected only a few parts of each
statute, often without adding every exception. It is an aid
to pinpoint the issues, not a guide to United States, Maine
Florida or Canadian legislation.
Table of Oil Spill Laws
What the
law does
REACHES
EXTRATER-
RITORIALLY
BODY TO
REGULATE
REGULA-
TIONS CAN
COVER
ACTS IN
CASE OF
SPILL
CONTIN-
GENCY
PLAN
CANADIAL ARCTIC
WATERS POLLUTION
PREVENTION ACT
100 miles from
shore above 60°
North latitude
Governor-in-
Council
Waste-threatening
activity, cargo,
ship; safety zone;
hull construction
sterring & propul-
sions gear; maximum
cargo; load lines;
maintenance; navi-
gation aids, crew,
lookouts & cleanups
supplies on board
pilotage, ine navi-
gators & breakers;
closed seasons;
load lines; lanes
Pollution Preven-
tions Control
Officer (PPCO)
Not specified
FLORIDA OIL SPILL
PREVENTION AND
POLLUTION CONTROL
ACT
None
Department of
Natural Resources
(D/NR)
Containment gear &
trained crew in
ship or terminal;
safety; removal by
state when owner
fails; criteria on
plans & means of
removal; minimum
sea conditions to
enter & master's
duty to report
his discharges &
troubles & denials
of entry; other
needed rules
Executive Director
of D/NR
State Plan plus
11 deep water
port plans
MAINE OIL DIS-
CHARGE PREVENTION
AND POLLUTION
CONTROL LAW
12 miles from the
coastline
Environmental
Improvement
Commission (EIC)
Operating ships &
terminals; safety
of ships & equipment
& inspection; remov-
al of pollutants;
control districts;
other needed rules
EIC (Governor also
has Civil Defense
powers)
State plans to be
developed
FEDERAL WATER
POLLUTION
CONTROL ACT,
SECTION 11
Zone allowed under
Territorial Sea
Convention when
proclaimed by U.S.
President (dele-
gated to the
Coast Guard)
Methods for remov-
al; criteria for
local & regional
plans; preventive
measures; equipment
on ship or shore
Coast Guard's
On-Scene
Commander
National Plan
by Coast Guard
regions
-------
STATE JURISDICTION. . . 59
Table of Oil Spill Laws (continued)
Law
SPILL OF UN-
KNOWN ORI-
GIN SPECIAL-
LY COVERED
DUTY TO
NOTIFY ON
NOTICE TO
GOTO
SPECIAL MEN
& EQUIP-
MENT
INSPECTION
CANADIAN ARCTIC
No
Master or person
in charge
Pollution Preven-
tion Control
Officer
PPCO's icebreakers
& (possibly) ice
navigator & pilots
Ship or shore site
FLORIDA
Yes
Pilot and master
Port Manager and
nearest Coast
Guard station
State and Port
Response Teams
and equipment
Terminals, ships &
MAINE
Yes
As regulated
As regulated
EIC may employ &
equip port or
state teams
Terminals, ships &
FEDERAL U.S.
No (yet subject to
surveillance sys-
tem called for)
Person in charge
"appropriate
agency" (as desig-
nated in rules)
Strike forces to be
set up or designated;
center to be set up
to co-ordinate & direct
national plan
Vessels "carrying oil"
ARE TERMINAL No, but permit
LICENSES would be needed
REQUIRED to operate, build
or expand one
© 1971 Daniel Wilkes
FORBIDS Any unauthorized
deposit or allow-
ing one; not
notifying of a
spill or threat or fol-
lowing orders of a PPCO
WHO IS
COVERED BY
IT
CRIMINAL
PENALTIES
EXEMPTED
FROM CRIM-
INAL LAW
AIDS TO
ENFORCE-
MENT
CIVIL
PENALTIES
EXEMPTED
FROM CIVIL
FINE
Depositors, owner &
master of ship or
cargo; i in charge
For deposit $5000/day &
$100,000/ship & for-
feit ship & cargo
(maximum) For others:
up to $25,000 & forfeit
No one
PPCO s have full
police powers
None
personnel
Yes for terminal
ships & personnel;
$300 fee & show -
cleanup ability
Discharging oil
in coastal waters
& lands unless re-
ported & removed;
an unlicensed ter-
minal; not notifying
of spill or follow-
ing orders & rules
Operator, master &
pilot, owner or 1
in charge
For failure to
notify: up to
$10,000 or two
years in jail
No one
Not specified
in Act
To $50,000/day
Immediate report-
er who fully re-
moves under rule
personnel
Yes for terminal,
ships & personnel;
one half cent per
barrel fee on oil
Discharging oil in
coastal waters &
lands or waters
that end up there;
violating orders,
rules or a license
Terminals & 1 vio-
lating a rule or dis-
charging oil
Per violation:
$10045000 per
day
One who promptly
reports & removes
spill under rules
EIC Inspection &
Enforcement em-
ployees have
powers of a
constable
None
No, but Corps of
Engineers permit
needed to build
or expand one
Discharging oil in
navigable waters,
shorelines or con-
tiguous zones in
amounts rules call
"harmful"; not
notifying of spill or
following rules
Owner, operator or
1 in charge
$10,000 or one
year or both is
maximum for
failure to notify
Person in charge
who notifies
immediately
President may ex-
tend enforcing to
contiguous zone
To $10,000/knowing
discharge & $5000/
other violation
No one
-------
60 LAWS AND ENFORCEMENT
Table of Oil Spill Laws (continued)
Laws CANADIAN ARCTIC
LIABLE FOR
DAMAGE
LIABLE FOR
COSTS OF
CLEANUP
EXEMPTED
FROM COST
OF CLEANUP
CAN THEY
DESTROY SHIP
AIDS TO
LAWSUITS
INFORMATION
OWNERS MUST
SUPPLY
FUND FOR
COSTS
SOURCE OF
FUND
AMOUNT IN
FUND
COSTS THAT
FUND PAYS
FOR
EXPRESS
RELATION TO
OTHER JURIS-
DICTIONS
Anyone for all
losses caused to
anyone
For reasonable
federal costs,
entrepreneurs, owner of
ship/cargo or charter party
No one
Yes
Liability of a
contributor for
his share
Any reasonable
information re-
quested
None (bond may
be required)
Cumulative with
provincial laws
under Canada Water Act
(within 12 miles of
shore)
FLORIDA
Not under Act or
Fund
Persons dis-
charging
Mere aider not
guilty of wilful
misconduct (he's
also exempt from
civil liability)
No provision
Can sue insurer
or surety direct
& owner of ships &
terminals must
have local agent
Terminal capacity
& plans & agree-
ments or equip-
ment for cleanup
Coastas Protec-
tion Fund
License fees & pen-
alties & $100,000
from treasury
To $5 million
Cleanup, abate?
ment, administra-
tion & rehabilita-
ting wildlife
Port Manager to
keep in touch
with Coast Guard
MAINE
Under Fund, for all
loss by anyone up
to indirect loss
of income
Oil terminal, for
acts of employee
or of ship which
uses it
No one
No provision
Can avoid suit in
claim settled by
Fund or arbitrated
As regulated
Coastal Protec-
tion Fund
1/2 cent/barrel
fee penalties &
reimbursements,
bonds
To $4 million
Cleanup by anyone,
damage to anyone,
administration and
research
No rule to be in-
consistent with a
federal one; towns
keep non-con-
flicting police
powers; EIC to
cooperate with
states, U.S. &
other nations &
agencies & can
agree with U.S. or
New England
Compactees
FEDERAL U.S.
Not under Act or
Fund
For costs to U.S.:
lesser of $ 100 per ton
or $14 million if ship,
S8 million if from
shore, unless wilful
misconduct
No one
Yes
Costs are liens on
ships; can sue in-
surer or surety
direct; injunction
authorized
As regulated
Revolving Fund &
possible bond
Fines, reimburse-
ments & U.S.
Treasury
To $35 million
Cleanup costs to
U.S. & owner who
is without fault
Federal may "coord-
inate and direct"
entire cleanup;
rules are cumula-
tive with state &
local, but Plan
rules may over-
ride states ones;
1954 Oil Convention
overrides all in
contiguous zone
-------
STATE JURISDICTION. .
61
WARNING :This Table is for illustrative purposes only as an
aid to understand the main areas and means of
setting out jurisdiction, liabilities both civil and
criminal, and regulatory responsibilities. It is
not a guide to legislation in Florida, Maine,
Canada or the United States. Each jurisdiction
has other statutory provisions in the Act used
as an example, aside from those summarized;
many provisions encapsuled above have ex-
ceptions or qualifications which are not set
forth, so as to make comparison easier. Lastly,
as "Common Law" jurisdictions, all four
governmental units include in their rules of law
those decisions of their courts in the past
which, by reason of persuasiveness or finality,
are supplements to statutory rules.
The above Table shows that the potential for state or
provincial jurisdictions to overlap with federal laws exists in
the United States, and through somewhat similar overlaps
in Canada, for almost every area of oil spill regulation. This
study will take up: first, the possibility of resolving these
overlaps by means of federal supremacy (in the United
States) in Part HI; next, in Part IV, the limits upon state
action in the absence of any valid federal exclusion from
concurrent rules; and lastly, in Part V, some preliminary
proposals for future jurisdictional developments.
EXCLUSION OF STATES OF THE UNITED
STATES UNDER THE 'FEDERAL
SUPREMACY CLAUSE'
Constitutional Framework
The framework for divisions of powers between the
Washington legislature and each of the 50 state legislatures,
from Alaska and Hawaii to the tip of Florida, is contained
in four parts of the United States Constitution: Article I on
the powers of Congress, Article III on maritime
jurisdictions, Article VI which makes certain federal laws
supreme over state ones, and the Tenth Amendment which
reserves certain unstated powers to each of the 50 states.
Basically, the following rules applying to overlaps are laid
down:
Rule One-77ze "Constitution., shall be the supreme
Law of the Land." (Article VI.) By court interpreta-
tion, this means that neither Washington nor state
lawmakers can pass valid laws which exceed some lim-
itation in the Constitution itself.
Rule Two-77/e "Laws of the United States (federal
enactments and decisional rulings) shall be the
supreme Law of the Land..and every State shall be
bound thereby," anything in the laws of any State to
the contrary notwithstanding. (Article VI.) This
means that any valid federal law which conflicts with
a state law will override that state law, unless some
unusually higher state right has been given to the
state by some other part of the Constitution.
Rule Three-TTze federal legislature has power to enact
all "necessary and proper" laws to carry out federal
functions under the Constitution, which include,
among others, these four powers related to oil spill
rules, namely, power to:
(1) lay uniform taxes;
(2) regulate commerce which goes to or comes
from outside any single state;
(3) define and punish "Piracies and Felonies
committed on the high seas, and Offenses
against the Law of Nations"; and
(4) "exercise exclusive Legislation" over areas
owned by the federal government by pur-
chase from a state, and provide for the gen-
eral welfare. (Article I.)
Rule Four-Treaties which bind the United States are
also "the supreme Law of the Land." (Article VI.)
Thus, federal laws to carry out obligations under in-
ternational oil pollution conventions, or similar treaty
arrangements such as the International Boundary
Waters Treaty covering water pollution disputes be-
tween the United States and Canada, may override
state laws, as may the treaty itself to the extent that
it is "self-executing".
Rule Five-Federal judges shall have power, to handle
"all Cases of admiralty and maritime Jurisdiction. "
(Article III.) This clause has been interpreted as per-
mitting Congress to give exclusive jurisdiction over
admiralty matters to federal courts, and to inversely
authorize the federal government to legislate in mat-
ters which affect any "navigable waters" of the
United States, which for our purposes include all
coastal waters where the high tide allows any boat to
go (or would but for silting up since).
Rule Six-v4// powers which the Constitution neither
delegated to the federal government nor prohibited to
the States are "reserved to the States." (Tenth
Amendment.) This means that some unspecified
kinds of state actions have been reserved to the states,
and a pollution abatement measure might conceivably
be held by a court to rest on such a power inde-
pendently of federal laws.
Effect of this Framework on
Regulation for Oil Spillage
Taken together, the above six rules give the Congress
ample room to take over practically all of the rule-making
functions in order to control oil spills. Action by any state
unit, therefore, must rest on either (a) an absence of federal
action—for example, arguably, if no sea lanes are laid down
to prevent tanker collisions in a harbor and the state's li-
cense to operate a terminal is conditioned on observance of
sea lanes; (b) federal laws which are not intended to "pre-
empt the field" of oil spill control or bar all state ac-
tion-for instance, as is currently the case under the concur-
rent regime of the Federal Water Pollution Control Act, as
amended, summarized in the Table of Oil Spill Laws above;
-------
62 LAWS AND ENFORCEMENT
or (c) some special state claim that it has an inherently
reserved right to take action in a given set of critical circum-
stances.
Special bases for this last type of power are discussed
in Part V below. Under the present concurrent regime, the
significance of state arguments about "reserved rights" may
be solely in those cases in which the federal government is
logically the one to make exclusive rules, but is deadlocked
and unable to act, so that a state unit's irreducible security
needs could be held by a judge to require it to act, rather
than to suffer the consequences of federal unwillingness to
act.
As a first step in rational jurisdictional management,
therefore, it will be important to identify those types of
rules where exclusive federal control is either logically or
jurisdictionally required. A preliminary list of items to be
considered for possible exclusivity might include:
1. Lighting on booms, floating barges, skimmers and
wrecked tankers which might perform both the navigation
safety functions of more general lighting requirements and
give notice of the special spill cleanup and fire or stain
hazards in the area. This is most logically an area in which
the Coast Guard should perform its traditional exclusive
role by promulgating and disseminating rules as quickly as
possible. There is no reason why a state's contingency plans
for oil spills cannot incorporate both the need for special
lights and knowledge about them, nor why interested states
cannot suggest rules or amendments based upon their ex-
perience. The need for uniformity, especially in interna-
tional waters, as well as the primary federal responsibility
for ship movements, puts this high on any exclusively fed-
eral listing.
2. Channels for one-way traffic for tankers, and for
vessels with which they might collide. From the Table of
Oil Spill Laws it can be seen that Maine envisaged this as
one of the functions for its Environmental Improvement
Commission, whereas the Canadian Arctic legislation made
this a federal function. At present, the United States federal
authorities have no such rules for Portland Harbor, the fifth
most-trafficked oil port in the United States. The question
arises, therefore, whether this state of affairs creates the
condition in which Maine might not take action under its
Oil Discharge Prevention and Pollution Control law and ar-
gue that its "irreducible security needs require the state to
act, rather than to suffer the consequences of federal unwil-
lingness to act?" As this is written (February 1971), the
Coast Guard has under consideration alternative routing for
sea lane separation for tankers entering and leaving Portland
Harbor. Thus, the logical denouement of an exclusively fed-
eral solution may soon be reached. The Maine example,
however, poses the type of problem which may be expected
for similar sea lane situations elsewhere.
The state's interest is still not small by any means.
First, the biological species placed in jeopardy by any tank-
er disaster are part of the resources which the state holds in
trust for its residents. Second, its public beaches and rocky
shores may, as in the case of Maine or Rhode Island or
Florida, play a principal role in recreation responsibilities of
the state unit to its people. Third, the men and equipment
siphoned to the site of a disaster, when they come from
state and local public employee groups, will be (a) far more
numerous than federal employees are likelyy to be, (b) far
more likely to be taken off other needed public service for
extended periods of time, and (c) far more disastrous to the
state unit than to the federal one in terms of both diver-
sions of human assets and diversions of the slim monetary
resources required.
The significant consequence of this is that no state can
"successfully" manage any but the most minor spill.lt will
always be the loser, and in the case of a tanker collision or
grounding during a delivery run, the relatively bigger loser
(at the very least until Disaster Funds begin to offset those
immediate diversions). Thus, the only spill "management"
against major spill threats is prevention.
This means two things: in arriving at exclusive federal
rules, state concerns for adequate preventive measures will
be entitled to significant influence, probably an influence
their legislators in Congress will be urging upon the federal
executive branch; and it will depend on that adequacy of
the final rules whether the exclusive powers of the Coast
Guard will be beyond reach of any overriding claim by the
state based on Rule Six above.
3. Minimum draught and sea conditions for tankers
entering port are expressly made subject to the Department
of Natural Resources in Florida under that state's Oil Spill
Prevention and Control Act. Here again is an area of ship
safety traditionally handled by the federal authorities.
Again, the state's concern is for "preventive medicine".
Here too, the remedy could be prompt and adequate feder-
al rules. One thing is certain: after the San Francisco Bay
Disaster of 1971 through collision in a fog, no state will be
any less concerned than Florida about preventive rules for
loaded tankers on their way into port. In some cases, the
prevention does not lie in barring entry, for the very rough
seas which may make entry hazardous make staying at sea
often just as risky; a regulatory response in terms of more
sophisticated entry navigation or deeper and wider channels
may be the right one, and here, too, the federal authorities
are the logical ones to act.
4. Hull construction, steering and propulsion gear are
reflected in Canada's schedules of subjects for preventive
regulation, and in more general terms in Florida and Maine,
powers to regulate ship safety. Functionally, freedom of
movement and ability to charter tankers to serve land-based
needs require some degree of uniformity; logically, there-
fore, international bodies, federal authorities or the
Commissioners on Uniform State Laws are the ones to for-
mulate any such protective requirements-awe? in that order.
It will only be through failure of IMCO or the federal
rule-makers to make an adequate response that any possible
tipping of the balance in favor of a unilateral state rule
could conceivably occur.
5. Enabling legislation for treaty obligations is properly
an area for exclusive federal control. It is worth noting,
however, that here, too, the adequacy of the federal re-
-------
STATE JURISDICTION. . . 63
sponse may be the key to whether state action is barred.
For example, when the Oil Pollution Act of 1924, as
enacted, was shown to be unduly restricted in light of the
Oil Pollution Convention of 1954, as amended, the ques-
tion of who would implement the Convention if the federal
government would not become a recurrent problem for
congressmen holding Hearings before the Committee on
Merchant Marine and Fisheries of the House of Representa-
tives in the spring of 1969. Since Rule Four says that all
treaties are "the supreme Law of the Land", a state could
conceivably enact enabling legislation-in default of federal
activity -to carry out the responsibilities which the United
States has as a result. For example, conditioning grant or
renewal of a terminal license on shore on adherence by
tankers entering or leaving the terminal to the Oil Pollution
Convention of 1954 might be a permissible state response,
or so it would argue.
History of "Exclusivity" Under the Studied
Laws on Oil Spills
Despite a specific request before the Public Works
Committee of the House of Representatives, during hear-
ings in April and May of 1968 on versions of the present
Section II summarized in the Table of Oil Spill Laws above,
the Congress rejected use of the federal supremacy powers
to make its federal oil spill law substitute for state action.
Page 358 of the transcript put out by that committee under
the title "Federal Water Pollution Control Act Amend-
ments -1968" shows that the marine general manager of
Mobil Oil Company asked that the new oil spill provisions
expressly preempt the field by providing that no other fed-
eral statutes could be construed as including within their
terms any discharge of oil and
that no State or local government or administrative
agency may impose on any vessel owner or operator
any requirement, penalty, or liability with respect to
cleanup of any discharge of oil into or on the territor-
ial seas or navigable waters of the United States.
The reason for this rejection by Congress of any language
which would invoke the 'Federal Supremacy Clause' is most
abundantly reflected in the fact that not a single govern-
ment official testifying wanted that power. On the con-
trary, repeated reference is made to the great reliance the
Coast Guard expected to place on the states and localities
living up to their duties to (a) handle the lesser spills en-
tirely by themselves and (b) play a large role in the support
groups to handle the larger spills. Also to the contrary is the
provision in Annex X of the National Contingency Plan
under paragraph 2005.2, in June 1970, that the use of dis-
persants, in any but exceptional cases spelled out pre-
viously,
shall be subject to this schedule except in States
where State laws, regulations or written policies that
govern the prohibition, use, quantity, or type of
dispersant are in effect. In such States, the State laws,
regulations or written policies shall be followed
during the cleanup. (Emphasis added.) "See FWPCA §
11(0)."
ADJUSTMENTS OF STATE AND
FEDERAL JURISDICTIONAL POWERS
The most superficial appraisal of the oil spill threat and
the resources to meet it in any federal system reveals that
enforcement of preventive and cleanup measures will need
both jurisdictions to be effective. The Coast Guard does not
have the inspectors, ships and lawyers to prepare and pro-
secute each and every case of infraction; the same might be
said of the United States Attorneys in each federal court-
house who must try the federal cases, of the state pros-
ecutors and coastal zone employees. What is said of so slow
a process as court enforcement goes double for the rapid
demands on both systems during a moderate or major spill.
In short, since neither can "go it alone", each will depend
upon concurrent enforcement possibilities by the other.
Concurrent Jurisdiction as a Device
to Enforce Exclusively Federal Rules
As a result, it is vital to keep in mind that no federal
rule needs to bar carbon copy state action in order to be
exclusive. The need for uniformity, or to preserve federal
interests in exclusivity for subjects of uniquely federal con-
cern, is not a need for federal enforcement alone; it is a
need for a single federally-formulated rule. This can be
done while multiplying the human, equipment and court
resources available on the order of ten to several hundred
times simply by retaining concurrent jurisdiction even in
Single Rule cases, just so long as the state enforcement can
conform to the federal rule.
Therefore, it is in the interest of the federal
government (1) not to "preempt the field" in oil spill con-
trol by expressly barring state regulation, and (2) to work
out concurrent enforcement possibilities under the regional
and sub-regional components of the National Contingency
Plan.
Overlap Areas Where Potential for
Conflicting Rules Exists
In most cases, there will be neither an exclusive federal
rule nor an absence of concurrent jurisdiction. A brief
glance across the columns of the Table of Oil Spill Laws
above quickly spells out the inevitable existence of con-
current administration, concurrent rule-making, and over-
lapping enforcement to be expected in any oil spill
incident. The problem is not how to eliminate the conflict,
but how to most rationally adjust the workings at both
levels.
The potential for conflicting requirements also lurks in
the data revealed by the following table prepared for this
study from Appendix C of the Dillingham Report's Volume
I on "Analysis of Oil Spills and Control Materials":
TABLE OF LISTED POTENTIAL DEVICES OR CHEMICALS*
Mechanical Equipment
Chemicals
Kind No. Listed
Booms 45
Recovery devices 35
Dispersant applicators 12
Pneumatic barriers 6
Domes 2
*As of February 1970 only
Kind No. Listed
Dispersants 1 26
Absorbent materials 37
Sinking materials 27
Burning promoters 3
Gelling promoters 3
Bird rehabilitators 2
-------
64 LAWS AND ENFORCEMENT
This early 1970 listing turned out to be only the top of the
iceberg. Just what adjustments are needed in each regula-
tory area of possible overlap, as discussed separately below,
one conclusion is easy to reach: it will take the scientists
and spill experts of federal plus state laboratories and teams
to provide the initial findings and evaluations for even the
most minimal list of products, species and oil environments.
1. Removal and containment methods
The most obvious place for predicted conflict between
state and federal officials lies in an area covered by spill
control powers in all of the four laws studied; this is in
methods of removal of the oil. Here especially, tempers can
be expected to run high in each of the following problem
areas if different levels insist on different inconsistent rules:
Booms-Vfhen there are not enough booms at the site
of a spill to prevent all areas of escape, choices will have to
be made. For example, the local official's primary concern
may be to have a boom protect a critical indentation in the
shore to save a local oyster ground. This might clash with a
Coast Guard On-Scene Commander's primary concern for a
slightly wider seaward circle of booms to keep the oil
pushing shoreward rather than out to sea. There are two
solutions to this type of problem. First, regional versions of
the National Contingency Plan and state laws both allow
the state to work out uniform protections in case of acci-
dent; thus, possible conflicts may be resolved in cooler per-
iods. Second, the very identification of such problems in
advance can play a role in setting requirements for booms
on hand for both private and public planners; there is no
good reason, for example, why our hypothetical conflict
should be allowed to arise, as both port safety and bed
survival are equally valid aims of spill control.
Removal equipment-The degree to which a state puts a
"crisis" tag on an oil spill potentially affecting key areas
will determine how important it will become to have equip-
ment (and storage barges or means) available to pump oil
off the surface as soon as possible, once a spill has occurred.
In a sense, federal interests should be no less; however, a
company's arrangements to have equipment brought in
when a spill occurs may seem more reasonable from a fed-
eral point of view than from that of any state or port which
sees catastrophic results if no equipment is available. This
could be the case, for example, off those parts of Long
Island's north shore where intensively cultivated oyster
beds are leased from the State of New York or owned
outright. Again, legal supremacy is no answer; advance
accommodations between state and federal officials is. Max-
imum safeguards to meet high priority local needs may be
the appropriate response as sophistication and equipment
availability increases. The oil company has a right to insist
that both levels impose costs of such on-site equipment or
storage capacity only when the interest to be protected is
sufficiently important to make such an expense reasonable
in all the circumstances involved.
Dispersants and non-sinking absorbent agents-The
prospect for the sharpest state-federal conflicts will lie in
the labelling under state and regional plans of Brand X as a
permitted dispersant or Brand Y as a prohibited one. At
present, under paragraph 2005.2 of the June 1970 National
Contingency Plan, federal authorities appear to be bound to
follow state rulings on detergents, at least in two cases:
(1) where the On-Scene Commander is not required to
act to reduce risk to life or risk of fire, and
(2) where the state has a law, regulation or written pol-
icy against it.
In our present state of flux, it is possible that the dis-
persants on hand will not have been ruled on by either a
regulation or a written "policy". (Only Canada has a speci-
fic law directed against the manufacture and sale of nu-
trient detergents which might apply within 12 miles of
shore after present administrative extensions run out.) An
argument can be made out, however, that the listing of
dispersants in the sub-regional or regional contingency plans
of the Coast Guard without any written protest from the
state amounts to acquiescence in their use where no policy
statement has been made at all.
If both state and federal lists are made up, however,
what may be a rare conflict can become an important one
to avoid. When both lists agree, there is no problem. The
ability of a state to ban a dispersant as
one which risks harm to local biological species of
concern to the people of this State or connected with
food chains on which fishes or other marine species
caught in state waters depend
is no small exercise of state responsibilities. The state's job
is (a) to protect the livelihoods of its commercial fishermen,
as in protecting Maine's lobstery from the havoc wreaked
by detergents on Brittany's lobsters after the Torrey
Canyon slick arrived (per J.E. Smith of the Plymouth Lab-
oratory); (b) to support recreational fishing, as off Florida;
and (c) to act as owner and trustee of the wildlife resources
within 3, or in two cases nine, miles of shore.
For the oil spill fighter there is a practical solution,
namely to have available supplies of those dispersants which
are allowed under both local and national lists, or have been
labelled as "least toxic" by the Water Quality Office on the
federal level and by its state counterpart laboratory.
For the two jurisdictions, however, sheer quantity of
testing suggests some adaptive rules be created. For in-
stance, state laboratories will be the ones more likely to
have established toxicity to local species under the syner-
gistic effects of local water quality conditions to be expect-
ed in oil spills. If they have done so, rational management
would suggest drawing up sub-regional federal lists based
upon state testing. Sometimes, on the other hand, the fed-
eral laboratory will have disclosed harmful effects from a
dispersant whose toxicity had not shown up in state tests.
Here, paragraph 2005.2 aside, rational management would
suggest changing the state's contingency plan to coincide
with the federal findings.
In a final class of cases, both sets of scientists will have
made identical tests and the state laboratory will "find"
-------
STATE JURISDICTION. . .
65
Brand Y toxic when the national laboratory "finds" it
non-toxic to the identical species. Here paragraph 2005.2
suggests a way to avoid a clash—the state promulgates a
written policy declaration against use of Brand Y and the
On-Scene Commander can follow it. In the long run, how-
ever, it is suggested that resolving conflicts by a State Su-
premacy absolutism will be no better than the theoretical
federal ability to proclaim itself supreme Two reasons are
pivotal here. First, oceanic movements as well as migratory
movements of fishes, crabs and lobsters make no spill
purely one state's affair. Second, far too much on-going
collaboration will be required for successful resource man-
agement and pollution abatement for avoidable conflicts to
be sought or for unavoidable ones to be resolved solely on
jurisdictional criteria.
The easiest accommodation to make, therefore, is to
allow cumulative regulation to prevail wherever possible.
Indeed, the "accumulation" will often have to include
other states in the region, or, for toxic results on a sea-
board-ranging fish like the mackerel, even all states on one
coast. Practical realities may likewise dictate needs to give
way in still other circumstances. For instance, tankers with
cargoes for Britain and the United States will have to have
BP-1100 available for use in U.K. waters, thus making this
dispersant one of the potentially available ones in spills of
the same tanker here. When COREXIT was first announced
in the New York Times of April 19, 1968 on page 81,
column 6, officials were reported to have announced this
dispersant would be carried by ESSO's entire 125-tanker
fleet; if such is in fact the case, it may make common sense
to have a clearance of this dispersant as "non-toxic to
marine species in foreseeable concentrations and synergistic
relationships" come from a national, or even international,
source instead of a state one. (Reports of toxicity of this
dispersant at the December 1970 FAO meeting in Rome
pinpointed the need for such an evaluation, although they
were themselves far from conclusive.)
Finally, it should not be forgotten that tradeoffs are
not merely between the costs of dispersion versus the risks
to local ecologies. Fire hazards, for example, attend certain
grade spills. Further, movement of a particular slick can
threaten beaches, coral reefs or fishing grounds elsehwere,
as in the Naval Sludge Dump Incident off Florida in 1970
where high seas fisheries and Georgian resources were with-
in range of the moving slick. Lastly, particular dispersants
may make oil brought on shore harder or easier for local
teams to remove, as in the OCEAN EAGLE disaster one
half mile from shore near San Juan, Puerto Rico in March
1968. There, the New York Times reported on page 1,
column 4 on March 5th that at least eight resort hotels had
to close their beaches "as oil and emulsifying chemicals,
used to combat the ever-widening slick, fouled the usually
clear waters," and the Dillingham Report stated that
treated oil of the 83,400 barrels of crude spilled was "much
harder to remove from shore".
Sinking materials and sinking absorbents-lhese raise
identical problems. In addition, however, the bottom and
bottom-related species are distinguishably threatened by
their use with significant consequences for potential clashes
in the decision whether to use them. These species, such as
lobsters and flatfish, are the very ones about which the
Coast Guard normally knows the least and state natural
resource agencies normally know the most. In this respect,
the Florida and Maine systems for dealing with spills differ
appreciably. The Florida Department of Natural Resources,
which regulates for and acts during spills, can actually be
expected to know more about sea and bay floor life than
federal navigation and spill control authorities. In Maine, on
the other hand, the analogous body is yet to be created,
and spill control is placed in the hands of the Environ-
mental Improvement Commission which has only some
overlaps with personnel knowledgeable about crucial shell
fish and flat fish grounds threatened by any choice to use
sinking materials; the Mullion Harbour bottom photo on
page 33 of Dr. Smith's 'Torrey Canyon' Pollution and
Marine Life shows most dramatically what ex-lobster
grounds can become. Yet it will be necessary to get biolo-
gists in the state government outside Maine's EIC to have
their say before contingency plans are drawn up if they are
to have an impact on the federal level.
LESSONS FOR FUTURE JURISDICTIONAL
GUIDELINES
LESSON ONE: Why federal control over planning and
directing spill control is the most logi-
cal
Logically, the federal government should take com-
plete charge because: (a) it has more territorial control,
nationwide expertise and mobilizable resources in ships,
planes, helicopters and men than the single state unit; (b) it
has the widest enforcement jurisdiction through: control
over all navigable waters, wide service of process papers,
and the widest power to reach owners of offending ships, as
by denying port clearance for an oil spilling tanker; and (c)
it has the most money, as in its authorized $35 million
revolving Fund for federal cleanup costs when the expected
appropriation comes in.
Yet, if the Coast Guard had both exclusive power and
responsibility over oil spills today, the ability to handle one
would be seriously set back. Federal authorities are most
often those farthest removed from local conditions and
often least knowledgeable about them. Then, too, Washing-
ton is just beginning to develop a core of men whose main
profession is to tackle major oil spills; this is the single
National Strike Force based on the East Coast. All other
federal authorities who might become involved, from the
Water Quality Labs to regional "strike forces" and
On-Scene Commanders, are men with other duties.
LESSON TWO: Why state control over planning and dir-
ecting action is case of a spill is the most
logical
Logically, state units should be strengthening their
ability to exercise jurisdictional control over spills because:
(a) they are closest physically to the scene in most cases;
(b) they are most familiar with the ecologies threatened and
-------
66 LAWS AND ENFORCEMENT
with their relative importance in the livelihoods and life of
the state; (c) they have more at stake in preventing, rather
than cleaning up, oil spills; and (d) they have been given
primary responsibility to control the quality of all waters
within their state by the federal government.
Yet, if the states had both exclusive power and respon-
sibility today, the ability to handle an oil spill would be
seriously set back. They have woefully inadequate re-
sources. For example, the Florida system begins, before the
first fees and fines come in, with only the $100,000 trans-
ferred from the treasury. With eleven deep water ports to
protect, this Coastal Protection Fund could not even pay
salaries for one expert per Port Response Team, let alone
for the equipment which Section 9 says must come from
this same Fund. Maine began its Oil Discharge Prevention
and Control Law functions with $30,000 for the first year,
two-thirds for wages and $10,000 for everything else.
In theory, the Maine Coastal Protection Fund will also
get fines and reimbursements plus the
One-Half-Cent-Per-Barrel license fee which terminal oper-
ators must pay on "oil, petroleum products or by-products
transferred" by the terminal each month. On the 1967 data
supplied by Dillingham Environmental Company, Portland
terminals handle a bit over 150,000,000 barrels each year.
Thus, an added $750,000 would be available for research,
inspection and spill cleanup in Maine. This fee is not col-
lected while it is being fought in the courts.
It is possible that the license fee will be sustained as a
reasonable burden for oil transport to pay toward prepared-
ness for spills. If so, the other 21 states with major ports
handling oil can be expected to consider following suit. The
illusion, however, is that this will make those states inde-
pendent of federal resources when moderate or major spills
occur, as the listing below shows:
EXPECTED STATE OIL SPILL FUNDS
FROM HALF-CENT4>ER-BARREL FEES*
ALABAMA
ALASKA
CALIFORNIA
CONNECTICUT
FLORIDA
GEORGIA
HAWAII
LOUISIANA
MAINE
MASSACHUSETTS
MARYLAND &
VIRGINIA
$ 154,000
33,000
1,772,000
351,000
668,000
73,000
204,000
409,000
789,000
662,000
584,000
MISSISSIPPI
NEW YORK &
NEW JERSEY
NORTH CAROLINA
OREGON
PENNSYLVANIA
RHODE ISLAND
SOUTH CAROLINA
TEXAS
WASHINGTON
$ 461,000
3,909,000
91,000
150,000
2,294,000
288,000
114,000
4,357,000
417,000
'based on Appendix B data in Dil-
lingham Report, vol. 1, rounded to
nearest 1,000.
The five states which would have over one million dollars in
their spill funds are among the very ones with the greatest
risk of major spills. In that same year of 1967, for instance,
tankers and oil barges made a trip into or out of a major
port: in California...20,000 times; in New York and New
Jersey...48,000 times; in Pennsylvania..! 2,000 times; and
in Texas—some 136,000 times, as shown by doubling round
trip port data from Dillingham's Appendix B. Since the
same Report shows on page 26 that over 60% of all major
spills surveyed occurred less than ten miles from shore, it is
clear that all twenty-two coastal states have both the high-
est stakes at risk and the greatest need for federal involve-
ment.
LESSON THREE: Thus, cumulative jurisdiction is a must,
especially for rational enforcement teams
Spill control is not the only area where each level of
government needs to have concurrent powers available. The
most critical need is for overlapping criminal enforcement
so that understaffed units, such as state Departments of
Natural Resources with manifold duties, can be reinforced
by Coast Guard employees who also must do other tasks.
Despite the obviousness of this need-which led Con-
gress to reject maritime requests for federal criminal
sections on oil spills to be exclusive-the most logical step to
make this two-level system work has not yet been taken.
This is to revise state laws so that federal officers, say in the
Water Quality Office and the Coast Guard, may issue sum-
monses for violations of state laws to bring charges into
state "courts. Often, for example, small cases belong in the
lower court system; yet, when it is the Coast Guard which
spots the violation, they either must prosecute in federal
court or find a state official to serve a summons or make an
arrest.
The reverse may also prove useful. For instance, often
ships of foreign registry are better brought in Canada and
the United States under the federal system with its clear-
ance tools and admiralty rules. A parallel exists under
Section 13 of the Rivers and Harbors Act of 1899, found in
Title 33 of the United States Code at Section 407, where in
certain cases a non-federal witness to pollution can bring a
suit. His action is based on the informer's interest in his
50% of the fine. The policy of allowing persons who are not
Coast Guard officers to initiate federal action in carefully
defined flagrant violation cases would be stronger, rather
than weaker, in the case of enforcement officers of the
state departments most immediately concerned with oil
spills.
LESSON FOUR: The logic behind exclusively federal rule-
making does not diminish this need for
overlapping enforcement.
This study has identified at least five areas where fede-
ral or international uniformity is functionally required.
These were: 1. lighting of booms, floating barges, skimmers
and wrecked tankers; 2. channels for one-way traffic; 3.
minimum draught and sea conditions on entering port; 4.
hull construction, steering and propulsion gear; and 5. laws
to implement treaties.
The same logic applies here which supports overlapping
jurisdiction in general, say during the 136,000 times per
year in which a tanker or barge enters or leaves Port Arthur,
Houston-Galveston, Corpus Christi or Brownsville in Texas.
So long as the state rules in an exclusively federal sphere are
carbon copies of the federal ones, as in required to avoid
conflict under the Maine law, for instance, dual enforce-
-------
STATE JURISDICTION. . .
67
merit does not destroy uniformity of rule while it does raise
chances for uniformity of enforcement.
LESSON FIVE: States will not leave regulation to federal
or international bodies where they are
left grossly inadequately protected against
spill threats to their own security
If an entire city of over one million people, such as
Qeveland, can lose 100% of its water supply by a spill in
Lake Erie, it would be a harsh rule-but a possible one-for a
federal judge to hold that Ohio must subject its coastal
cities to possible risk of a waterless period if the federal
legislature so insists. Honesty, however, must force lawyers
to advise federal officials that state claims to an irreducible
level of security below which federal and international in-
action cannot make them go may well be upheld by judges
in today's atmosphere of environmental concern.
There are at least five theories under which such state
powers to override grossly inadequate rule-making at higher
levels could be urged upon a sympathetic court:
The Burden-on-Exclusivity Theory-A court, putting
the burden of persuasion on the one arguing for
exclusivity, could find that Congress could not have
intended to "preempt" where to so hold would lead
to an unconscionaable result.
The Tenth Amendment Theory-The judge could
find, under our Rule Six above, that the powers
reserved include the right to survival-oriented spill
prevention rules, at least where the federal legislation
or rules are materially less stringent than state ones.
The Property Right Theory-A court could enforce
state rules on the ground it is owner and trustee of
public lands and waters "granted and confirmed" to
the state under the Submerged Lands Act of 1953; its
claim would be, not to stand vis-a-vis the national
government as a competing jurisdiction, but rather as"*
an owner entitled to "due process" before its
property is put in jeopardy.
The Inherent Right Theory-It may be held that fed-
eral rules cannot deprive states of those powers which
must inherently be included to carry out duties which
are left clearly theirs; thus, when a 8.4 million gallon
tanker runs aground in fog outside New Haven
harbor, as happened this past January, and Connec-
ticut employees are required to try everything to
protect and rehabilitate wildlife and shorelines, it
may be judicially required to hold that Connecticut
cannot be deprived of incidental powers needed to do
this job or to minimize chances of such spills.
The Police Power Theory-A judge might prefer this
theory to fit into familiar frameworks in the case law
by holding that the residual powers of a state which
override some constitutional federal powers include
the right to "police" to some minimum extent nec-
essary to avoid injuries to public health and safety,
such as might attend an oil spill.
LESSON SIX: More attention should be paid to state-
federal collaboration than has been giv-
en to it in the past
This study has been a preliminary one; neither time nor
the limitations placed on this unfunded study for the 1971
Conference on Prevention and Control of Oil Spills have
made it possible for all ramifications to be explored, nor for
the present findings to be elaborated upon. The working
out between the Coast Guard, the Federal Water Quality
Laboratory and state officials of sub-regional contingency
plans has so far proven to be the most effective means to
date of ensuring the kinds of collaboration called for, yet it
has not touched upon most of the very issues raised above.
The findings also suggest that states will step into the gaps
if such further work is not done-and soon.
LESSON SEVEN: Future international work must bear in
mind that these rationales for state uni-
lateral action in a federal system apply
to nations within the international one
if inadequate steps are taken there
This lesson is most dramatically reflected in the history
of the Canadian Arctic Waters Pollution Prevention Act,
summarized in the Table of Oil Spills above. The key impe-
tus for that act was the failure of the IMCO Conference at
Brussels to adequately address itself to the question of
preventing spills. Yet, according to senior scientist Dr. Max
Blumer of the Woods Hole Oceanographic Institute, the
dangers to shore and bottom communities from dousirigs
with oil, toxic effects from dispersants or habitats de-
stroyed by sinking agents, when combined with possible
risks of cancer in humans as more hydrocarbons enter the
food chains, lead to but one conclusion: the only way to
successfully manage oil spills is to prevent them.
-------
OIL SPILL PREVENTION, CONTROL
AND MONITORING
Chairman: Rear Admiral C. A. Richmond
United States Coast Guard
Co-Chairman: Commander W. E. Lehr
United States Coast Guard
-------
REMOTE SENSING OF OIL SPILLS
Clarence E. Catoe
and LTJG Frederick L. Orthlieb
Office of Research & Development
United States Coast Guard
ABSTRACT
A prerequisite for the control of coastal oil pollution is
the development of surveillance techniques which are capa-
ble of monitoring large areas of the ocean surface to detect
the presence of oil slicks. The U.S. Coast Guard Office of
Research and Development is currently engaged in basic
and applied research to determine the feasibility of various
remote sensing techniques for the detection and identifica-
tion of oil slicks. To date, several remote detection tech-
niques have shown promise for the detection and sur-
veillance of oil slicks; these were tested in a series of air-
borne measurements of controlled oil spills.
INTRODUCTION
Two separate experiments were conducted by the
Pollution Control Branch. The first was conducted in the
Gulf of Mexico approximately 80 miles offshore. This
experiment was concerned with the detection and quantifi-
cation of oily discharges from vessels underway. Using a
carefully calibrated metering pump, an extensive series of
controlled volume oil spills was generated. Each slick was
photographed in color and black and white from an or-
biting helicopter and from a vessel one-half mile astern.
Trackline overflights at 2000 feet were conducted utilizing
color visible, color infrared, and multispectrial ultraviolet
cameras, as well as passive microwave radiometers operating
at 10 Ghz and 30 Ghz. Data were obtained for five oil types
at 3 ship speeds over a wide range of surface and atmos-
pheric conditions.
The second experiment consisted of a series of four
controlled oil spills in which 330 gallons each of (1) No. 2
diesel fuel oil (39 API gravity), (2) Bunker C oil (9.7 API
gravity), (3) 21.6 API gravity crude, and (4) 26.1 API grav-
ity crude were discharged off the Southern California
coast in October through December 1970.
The objectives of this experiment were (1) to obtain
multjspectral signature data of oil spills and to determine
the capability of remote sensing techniques for surveillance
and detection of slicks, and (2) to determine from remote
sensor and surface vessel observation the spreading rate and
extent of the oil slicks in the ocean.
Background
Gulf of Mexico Experiment
The first controlled oil slick experiment was performed
in April 1970 to provide a tested means of aerial surveil-
lance, and detection of spilled oil, as well as a set of refer-
ence photographs of spills of known volume and concen-
tration for comparison with photographs of suspected pol-
lution violations.
Under the provisions of the International Convention
for the Prevention of Pollution of the Sea by Oil, 1954, as
amended in 1962, and as promulgated by the United States
Government in 33 U.S. Code 1001, certain vessels are pro-
hibited from discharging oily mixtures containing more
than one hundred parts oil per million parts mixture within
specified oceanic and coastal zones. A 1969 amendment to
that Convention, currently awaiting final ratification,
would revise the oil discharge limit upward to sixty liters of
oil per nautical mile of ship's track. In either case, enforce-
ment of 33 USC 1001 has been delegated to the Coast
Guard.
Prosecution of violators under the law requires first-
hand proof of illegal discharge, especially in the absence of
a confirming entry in the vessel's Oil Record Book. Such
evidence usually takes the form of aerial surveillance photo-
graphs, which are interpreted by expert witnesses as de-
picting either more or less than the legal limit of pollution.
This procedure is readily subject to challenge, especially
under the hundred parts per million (ppm) criterion, since
the apparent oil slick is dependent upon the total amount
of oil discharged, rather than its dilution in an effluent
71
-------
72 OIL SPILL PREVENTION .. .
stream. Sea and sky conditions also greatly influence the
appearance of surface slicks.
Reference photographs showing the appearance of oil
slicks of known volume and concentration under a variety
of sea and sky conditions could serve as standards of com-
parison for both initial decisions as to the probable legality
of a particular discharge, and for presentation of surveil-
lance photographs during courtroom activities. They would
help to substantiate the testimony of expert witnesses in
borderline cases, and might obviate such testimony in cases
of gross and flagrant violation.
Southern California Experiment
From 22 October to 3 December 1970, a series of
experiments were conducted to study various techniques of
remote oil slick measurement. The tests were conducted on
the open ocean in the vicinity of 119° 08, west longitude,
33° 45, north latitude (off the California coast). During this
period four sets of test were made.
Each experiment involved spills of 300 gallons each of
diesel oil and 9.7, 21.6 and 26.1 API gravity crude oils in
discrete slicks. A 65 foot work boat was used to gather
ground truth data, as well as to generate and monitor the
slicks. The data collected during these tests consisted of:
local weather, water temperature, humidity, surface winds,
sea state in and out of slicks, condition of oil, thickness at
edges and center (for possible volume determination), size
of oil slick, area of coverage, location of observers and time
of observation. The boat remained with the slicks in the
test area until they had dissipated (approximately three
days).
Airborne measurements with various sensors were
made of the slick periodically throughout its duration.
The timing of the four sets of tests was dependent
upon weather and sea state conditions. During the course of
the experiment an attempt was made to cover a broad range
of sea surface conditions from calm to fairly rough.
Experimental Results
Gulf of Mexico Experiment
In the period 6-12 April 1970, controlled oil slicks
having concentrations up to and including the legal limits
were produced and photographed. Each of the five oil types
was tested at ship speeds of 10, 14, and 17 knots, in order
to determine possible wake turbulence effects on the dis-
persion of the oil stream. A total of 103 tests were con-
ducted, including underway and static oil spills, a few
underway spills of non-persistent gasoline-oil mixtures, and
a static spill (ship drifting) of sub-surface water from the
River Rouge in Detroit, Michigan. Weather conditions from
clear and calm to rain and fog with moderate seas were
encountered. The remote-sensor equipped aircraft overflew
the entire series of tests; a separate report has been pre-
pared covering the overflight program.O)
The oil types and discharge rates used in the Gulf ex-
periment were:
Oil Types
No. 2 Fuel Oil - a light distillate, often spilled during
in-port fueling and ballasting of a wide range of vessels.
9250 Lube Oil - a medium weight ( ~SAE35) product,
often the major constituent of bilge-pumping discharges.
Crude Oils - account for the bulk of marine oil trans-
port; spilled in varying quantity as a result of tank cleaning
and deballasting of tanker vessels.
South Louisiana Crude - a low viscosity crude, con-
taining many lighter fractions and natural surfactants which
promote spreading over water.
Trix-Liz Crude (Texas) - a high viscosity, low sur-
factant crude having a much lesser spreading tendency.
No. 6 Fuel Oil - the most widely used residual fuel,
transported in large quantities and often spilled during
transfer operations.
Discharge Rates
Pumps through which ships might discharge oil or oily
mixtures range in capacity from 50 gallon per minute
(GPM) bilge pumps upwards to 2-5,000 GPM cargo and
ballast pumps. Simulation of such a wide range of flow
might have been impossible, had it not been discovered by
the British during earlier experiments*2) that the
appearance of a vessel-generated oil slick on the ocean
surface depends chiefly upon the total quantity of oil dis-
charged per mile of ship's track, regardless of the volume of
the effluent stream in which it was mixed, provided that
the oil was well mixed into the stream. Thus, an entire
family of discharge mixtures might be simulated by a single
test discharge having the same net oil content. For example,
a controlled discharge of pure oil at a rate of 0.1 GPM will
correspond to any discharge wherein the product of the oil
concentration and total discharge rate equals 0.1 GPM, pro-
vided that the experimental oil flow is well mixed into the
ship's wake. In the tests conducted for this project, dis-
persion of the oil into the wake was achieved by intro-
ducing a metered stream of oil directly into the wake just
aft of the ship's stern, whence it was sucked into the twin
screws and violently churned into the turbulent wake area.
Table 1 presents the mixture discharge rates and ppm con-
centrations simulated in this experiment. The production of
controlled slicks similar to the proposed 60 liter per mile
limit is equally straightforward, but ship speed rather than
mixture discharge rate is the controlling parameter. For
example, a ship making 15 knots travels one mile in 4 min-
utes; the oil flow to produce a 60 liter/mile slick is there-
fore 60/4 or 15 liters per minute, whereas a ship making 10
knots would cover one mile in 6 minutes, and the oil flow
to produce a 60 liter/mile slick would be 60/6 or 10 liters
per minute. It is therefore apparent that oil flow to produce
a slick of specific intensity is directly proportional to ship
speed. This relationship is shown in Table 2.
Having accounted for the effects of oil type, discharge
rate, and ship speed, there remain sea and sky conditions
and viewing angle as variables of concern. The availability
of test vehicles was severely limited and precluded waiting
on weather. To determine the effect of viewing angle on
-------
REMOTE SENSING OF SPILLS 73
slick detectability, an operational scenario was developed
which provided both aerial and surface platform photo-
graphic coverage. Aerial photos in both color and
black-and-white were obtained from an HH-52A helicopter
flying a clockwise oval pattern at an altitude of 500 feet
over the slick, including bow, starboard bow, starboard
quarter, stern, port quarter, and port bow aspects of the
oil-spilling 210 foot Medium Endurance Cutter, with one
additional color exposure at stern aspect from an altitude
of 200 feet. Surface photos were taken from an 82 foot
Patrol Craft while following 1/2 mile astern of the "210",
at positions within and directly alongside the oil slick, and
including bow, beam, and quarter viewing angles. Figure 1
is a schematic plan view of these photographic locations.
Parts-Per-Million Equivalents
Volume Basts
^S. 20
0.01
= 0.02
1 0.05
o
- 0.1
3
0.2
1 0.5
g
E! i.o
5 2.0
5.0
500
1000
2500
5000
1C 000
25 000
50 000.
100 000
250 000
TOTAL DISCHARGE RATE - Gallons/Minute
50 , 100 , 200 500 . 1000
200
400
1000
2000
4000
10 000
20 000
40 000
100 000
| 100
200
500
1000
2000
5000
10 000
20 000
50 000
50
[ 100
250
500
1000
2500
5000
10 000
25 000
20
40
100
200
400
1000
2000
4000
10 000
10
20
50
TOO
200
500
1000
2000
5000
2000
5
10
25
50
100
250
500
1000
2500
5000
2
4
10
20
40
100
200
400
1000
Solid Line — « 100 parts-per-roillion liitit
Dashed Line • 60 liters-per-nile limit («t normal ship speeds)
Table 1: Oil Flow Rate as a Function of Total Discharge Rate
Slick Intensity
11ters/mile
1
2
5
10
20
30
60
90
120
Oil Flow Rate
1iterS'-"-/knot
0.016
0.03
0.08
0.16
0.33
0.5
1.0
1.5
2.0
Flow at 15 Knots
9a11ons/mi-n.
0.066
0.13
0.33
0.66
1.32
1.98
3.96
5.94
7.92
River Rouge water spill remained coherent long enough to
obtain any photographic record.
Neither color nor black and white surface photography
provided sufficient discrimination between oil slicks and
the clean surface to be useful as a reliable means of pollu-
tion detection.
Aerial color and black and white photographs were ob-
tained under a wide variety of atmospheric and sea condi-
tions during the experiment. These photos hold the most
promise of serving as useful surveillance tools. Table 3 gives
the author's evaluation of the slick detection achieved for
each test.
Table 4 gives equivalent discharges in liters/mile and
gallons/minute as an aid in evaluating the detection capabil-
ities of conventional aerial photography under either the
100 ppm or the 60 liter/mile criterion.
-= Not Detected
+ = Positive Detection
? = Detection Uncertain
0 = Not Tested
N^.05 GPM
#2
FUEL OIL
9250
LUBE OIL
10
kt
LIGHT 14
CRUDE kt
17
kt
HEAVY
CRUDE
#6
FUEL OIL
0
0
—
—
0
—
—
OIL FLOW
0.1 GPM
-
—
7
?
7
+
7
RATE
0.5 GPM
?
—
+
+
+
+
+
1.0 GPM
+
+
+
+
+
+
+
60 jP/mi
0
0
+
+
-f
+
+
Ship Speed = 14 knots Unless Otherwise Noted
Table 2: Dependence of Oil Slick Intensity on Ship Speed
Aerial and surface photographic data were obtained for
all tests, but only spills of persistent oils were detected by
photographic means. Neither the gasoline spills nor the
Table 3: Photographic Detection Results
-------
74 Ol L SPILL PR EVENTION
Altitude
500'
500
Altitude
Figure 1: Diagram of Aerial and Surface Photographic
Locations
Southern California Experiment
Microwave Radiometric Investigations
Before the sea tests were conducted, laboratory mea-
surements had been performed on the petroleum pollutants
which indicated that:
1. The microwave signature of an oil film is inversely
proportional to the sensor wavelength.
2. The horizontal polarized signature is twice the ver-
tically polarized signature of an oil slick on a flat water
surface.
3. All signatures were greater than calm water without
oil (as shown in Figure 2).
In addition, the dielectric properites of the pollutants
were measured at 0.8 cm wavelength using an ellipsometer
(precision reflectometer). The real part of the dielectric
constant for the petroleum pollutants ranged from 1.85 to
2.41 as compared to a value of approximately 21 for sea
water at 23°C. A slight increase in the real part of the
dielectric constant and in large increase in the imaginary
GALLONS
PER
MINUTE
0.01
0,02
0.05
0.1
0.2
0.5
i.O
2.0
2.69
3.77
4.57
LITERS PER KILE
At 10 knots At 14 knots
.227
.455
1.14
2.27
4.55
ii.<»
22.7
45.5
60.0
.163
.325
.813
1.63
3.25
8.13
16.3
32.5
60.0
At 17 hrcts
.134
.268
.669
1.34
2.6S
6.69
13.4
26.8
60.0
[50
[40
1 30
I 20
i 10
' 0
Table 4: Oil Discharge Rate Equivalents
1.1» minim piutiann rai
UtLE 31° Fill Mill
^.-"^"^ Bunker "C"
nSf^^-^^^-^T. 2.9*' c-rtiZ
05
111 Fill TIICIKSS II Ml
30
2O
IO
n
r i » » unziiTii riunaiin mi
HUE 31° Fill Illll
Bunker
^-
-.
____ _ . . — •*
ilZ-20 API
40 API —
1 1
O.I
0.5
III Fill TIICIKSS II II
Gasoline
1.0
* Low vohMS may be due to nan-uniform distribution of oil
l-'igure 2: Summary of Microwave Response to Petroleum
Samples Examined During Laboratory Experiments
part were observed as the pollutants aged (shown in Figure
3). The ellipsometric measurements showed an almost lin-
ear increase in the dielectric constant for crude oils with
decreasing API gravity.
The airborne measurements were performed using dual
polarized radiometers operating at 0.3 cm and 0.81 cm
-------
REMOTE SENSING OF SPILLS 75
wavelength. A Piper Apache aircraft with the radiometers
mounted at a view angle of 45° was used for these tests.
The antenna brightness temperatures of the slicks (300 gal-
lons of pollutant) showed increases on the order of 3-20°K,
as indicated in Figures 4 and 5. Radiometric temperature
anomalies were dependent on the oil thickness and sea con-
ditions during the overflights. The brightness temperature
anomaly for a given thickness of pollutant is less for higher
sea states (warmer radiometrically) than the same thickness
on a calm sea as indicated in Figure 6. These measurements
indicate thinner oil slicks are more detectable than had
been expected at low sea states. Analysis of laboratory data
(Figure 6) show the vertical polarization temperature does
not vary appreciably for thicknesses less than 0.10 mm at a
view angle of 45°.
From the microwave investigation of the controlled oil
spills the following conclusions can be made: (1) the emis-
sivity of petroleum products is significantly higher than
that of a calm sea surface, (2) crude oil pollutants have
decreasing dielectric constants (increasing emissivity) with
increasing API gravity, (3) time of day and age of oil have
only small effects on the radiometric response, (4) detec-
tion improves with decreasing sensor wavelengths, and be-
comes poorer as the sea state increases, and (5) a microwave
oil pollution detection system can be configured for de-
tecting oil slicks of the type examined during the experi-
ment.
3.2 I-
2.8
_ 2.4
2.0
X 1.6
•- 1.2
0.8
0.4
0.0*
A«0.8I cm.
AGED 3 DAYS
N AIR
IN OfEK
EFFECT
AGING
FRESH OIL
VACUUM
_L
20 30 40
API UNITY
(•-BDNKEI '(' FUEL OIL]
l-'igure 3: Dielectric Constant of Crude Oils Versus API
Gravity
Spectroradiometric Investigation
The objective of this program was to evaluate several
radiometric techniques for detecting oil on water, by mea-
suring the contrast of sunlight as reflected by oil and water.
Figure 7 illustrates the overall technique: oil and water re-
flecting or backscattering sunlight to the aircraft.
For test purposes a Cessna 401 was equipped with a
Carey 14 spectroradiometer which operated from .3 to 1.1
micrometers with and without polarizing attachments. Dif-
ferential and correlation radiometers were used to compare
two or more specified frequencies associated with oil fluor-
escence in the ultraviolet and blue end of the spectrum.
Since variations in solar intensity, spectral distribution,
polarization and angle of incidence influence the radiance
measured by the above instruments, the next few figures
illustrate the characteristics of the skylight. Figure 8 illus-
trates the amount of direct and diffuse sunlight impinging
upon a horizontal surface, showing that the diffuse compo-
nent increases with cloudiness. One of the results from this
investigation is that the best contrast between oil and water
is obtained under overcast sky conditions. This is due to
the increase in the diffuse component. Figure 9 illustrates
how the spectral distribution of sunlight varies with the
sun's position in the sky. Sunlight impinging from different
directions will therefore have different spectral dis-
tributions. Figure 10 illustrates that skylight depends on
the angle of incidence and sky conditions.
Results of this portion of the experiment indicated the
following:
1. The maximum contrast between oil and water is in
the ultraviolet (380nm) and the red (600 nm).
nm.
2. The minimum contrast is in the range 450 to 500
3. The oil almost always appeared brighter than water.
4. Light oils appeared brighter than heavy oils.
5. No distinct absorption regions, which would dis-
tinguish one oil from another were observed.
6. Sky conditions are the most important factor in-
fluencing these results. Best contrast was achieved with an
overcast sky.
7. The effect of sea state needs more research.
8. Density gradients in the oil are qualitatively detec-
table, but more research is needed for quantitative results.
9. Polarization is a promising technique.
10. Future studies should be conducted with spectro-
radiometers which either rapidly scan or record several
wavelengths simultaneously.
-------
76 OIL SPILL PREVENTION...
10
20
125
TIME IN SECONDS
30 40 50
60
70
8O
5 75
50
-3 25
\\N^lVXy^^
OIL SLICK
1700
3400
5100 6800 8500 10200 M900
DISTANCE IN FEET
DATE' 10/30/70 X = 8.1mm
A/C ALTITUDE = 100 FT ANTENNA VIEW ANGLE = 45°
A/C SPEED = 115 MPH SLICK DIMENSION = 595 FT.
WATER TEMP = 16.4 OIL TYPE = MERGED 9.7, 21.6, 26.1
SEA STATE = 0 AND 34.1 API GRAVITY
12600
Figure 4
Multispectral Investigation
The University of Michigan, using their Douglas C-47
aircraft, overflew the controlled oil spills and obtained
multispectral imagery from the ultraviolet, visible, and in-
frared portion of the electromagnetic spectrum.
The multispectral imagery obtained provided a quali-
tative look into the problem of oil pollution detection.
Examination of the imagery in conjunction with conclu-
sions drawn from theoretical modeling of the slicks has shed
some light onto the question of interaction and the rela-
tionship between the thermal and UV region of detection.
Also, laboratory fluorescence data on several oils has indi-
cated that potential identification of oil types may be pos-
sible using fluorescence signatures as indicated in Figure 11.
Shown in Figure 12 is a black and white print of the
ultraviolet (.32-38 micrometer) imagery. At least a part of
all four types of oils used in the experiment show up on
brighter than the water background, while three of the oils
(21.6 API Crude, 26.1 API Crude, and Diesel fuel) also have
areas that are darker than water. This change in contrast
relative to water is due mainly to thickness variation within
the slick. However, it is also a function of oil type as shown
in Figure 13.
Using index of refraction and scattering and absorption
coefficients measured in the laboratory, a mathematical re-
flectance model for oil on water was used to generate values
of radiance from each of the four oils as a function of
thickness. The results for the UV region (.36-.3S micro-
meters) are plotted in fugire 12 along with values for two
types of water. The meteorological condition were set up to
match those of the actual flight. It is obvious from the
-------
REMOTE SENSING OF SPILLS 77
TIME IN SECONDS
10
20
30
40
50
oo
CO
OIL SLICK
I
I
A =8.1 mm
TIME IN SECONDS
IOO
75
50
25
10
20
30
40
50
T
T
1
1700 3400 5100 6800
DISTANCE IN FEET
ANTENNA VIEW ANGLE = 45°
SLICK DIMENSION = 105 FT
OIL TYPE = 26.1 API GRAVITY
DATE = 10/28/70
A/C ALTITUDE = 200 FT
A/C SPEED = 115 MPH
WATER TEMP = I6.4°C
SEA STATE = I
8500
1700 3400 5100 6800
DISTANCE IN FEET
ANTENNA VIEW ANGLE = 45°
SLICK DIMENSION = 935 FT
OIL TYPE = 26.1 API GRAVITY
DATE: 10/28/70
A/C ALTITUDE = 200 FT
A/C SPEED = 115 MPH
WATER TEMP = I6.4°C
SEA STATE = I
8500
Figure 5
graph that in the UV, thin layers of oil should be brighter
than water while thick layers will be darker, the cross-over
point being a function of the type of oil and water present.
The reason behind this change in reflectance with thickness
of an oil layer may be explained as follows. The radiance
viewed by the observer consists of two components, a
specular part (not sunglint) which is related to the oil layer
and an upwelling diffuse portion from the water beneath.
The specular radiance from the oil is essentially constant.
The diffuse radiance from the water varies with oil layer
thickness. The diffuse component is maximum for clear
water but approaches zero for very thick oil films.
In the thermal region, one finds intriguing results. Figure
14 shows a black and white print of the thermal (9.3-11.7
micrometer) imagery. Comparing figure 14 and figure 12,
one sees that, for crude oils, the lightest areas in the UV do
not appear at all in the thermal; whereas, the areas of
intermediate UV brightness appear colder (darker) than
water,and the darker-than-water areas in the UV show up as
hotter than water in the thermal. Diesel fuel, on the other
hand, shows up as colder than water while the intermediate
or darker UV areas appear somewhat warmer (though still
colder than water). The obvious conclusion to be drawn is
that thickness variations (as observed in the UV) are having
some effect on emitted radiation, although at present one
can only hypothesize as to the reason behind this effect.
One possible explanation is that as the oil layers become
thicker, evaporation losses from the volatiles present
increases, producing lowered temperatures in the slick.
However, as the oil becomes thick enough to absorb
significant solar energy, this cooling trend is overwhelmed
by solar heating and a "warm" slick results. The highly
volatile and relatively transparent diesel soil never attains
enough thickness to permit significant solar heating, and
thus always appears colder than water. Even here, however,
the thickest portions are slightly warmer than the
surrounding areas of moderate thickness.
-------
78
OIL SPILL PREVENTION . . .
TIME IN SECONDS
10
— 100
— 75
50
— 25
I70O 34OO 5IOO 6800
DISTANCE IN FEET
ANTENNA VIEW ANGLE = 45°
SLICK DIMENSION = 2550 FT
APPROXIMATE OIL THICKNESS = .068mm
OIL TYPE = 21.6 API GRAVITY
DATE: I2/2/7O
A/C ALTITUDE = 100 FT.
A/C SPEED = 115 MPH
WATER TEMP. = I2.8°C
SEA STATE=4
TIME IN SECONDS
10
20
30
40
BOAT-
IOILSLICK! —
X 3 3mm
I
170O 34OO 5IOO
DISTANCE IN FEET
6800
ANTENNA VIEW ANGLE -45°
SLICK DIMENSION = 2550 FT
APPROXIMATE OIL THICKNESS =. 068mm
OIL TYPE =21.6 API GRAVITY
DATE: 12/2/70
A/C ALTITUDE = IOO FT.
A/C SPEED = 115 MPH
WATER TEMP. = I2.8°C
SEA STATE =4
Figure 6
sntmuimina
u
wntmui uuwmi
l;igurc 7: Airborne Oil Slick Detection
-------
REMOTE SENSING OF SPILLS 79
no
100
90
IE 80
ca
•70
I50
140
30
20
10
0
TOTAL (DIRECT AND DIFFUSE)
DIFFUSE ONLY
CLEAR SKY
CIRRUS
ALTOCUMULUS
STRATUS
1.00
20 4O 60 80
SOLAR ZENITH ANGLE
100
Figure 8: Solar Irradiance at Ground Level
ZENITH ANGLE: 50°
240
200
•160
u go
40
300
Figure 9:
500
ffAVELENGTH.il
700
900
Spectral Distribution of Diffuse Radiance at
Various Azimuth Angles
Analysis of the thermal, visible, and UV data obtained
thus far has indicated that no signatures exist in the passive
mode which would permit identification of oil types. Al-
though it has been demonstrated that the UV region can
define the areal extent of an oil slick and that the UV
together with the thermal region gives thickness informa-
tion, neither holds much promise for identification. The
key to the problem may be in the fluorescence spectrum
DEGREE OF
POLARIZATION
.20 -
ANTISOLAR
POINT
Figure 10:
5 .6
£= -4
-.20
90 7O 50 30 10 10 30 5O 70 90
NADIR ANGLE, deg.
Degree of Polarization as a function of Direction
in the Sun's Vertical
ucimiiii snciu IIEFMEI IIESELJ
IESPIISE SPECTII (IEFIIEI IIESEL)
EieillTIIK SfECTII (HUE)
V-iE$n«j[
(tint)
ZOO 28O 360 440 52O GOO 68O
•mtEKTI, »
Figure 11: Detection and Identification of Oils by
Fluorescence
Radar Investigation
The Naval Research Laboratory using the EC-121 air-
craft equipped with the NRL four frequency dual polarized
radar system participated in two of the controlled oil spill
tests.
The 4FR system is basically four different pulsed co-
herent radars transmitting at P-band/UHF (428 MHz),
L-band (1228 MHz), C-band (4455 MHz) and X-band
(8910Mhz) with approximately 25 kw peak power. Each of
the four transmitters is designed to operate with two an-
tennas, one polarized horizontally and one vertically, either
separated or pulsed in rapid succession to provide a total of
eight different frequency polarization combinations. Al-
though these are eight distinct transmissions from the 4FR
system, there are 16 different frequency polarization com-
binations in the return. This is because the ocean surface
-------
80 OIL SPILL PREVENTION ...
9.7 API FUEL OIL 21.6 API CRUDE OIL
26.1 API CRUDE OIL #2 DIESEL FUEL
Hgure 12: Black & White Print of Ultraviolet Imagery Alt: 2000' Time: ]200 \ = .32-.3S
xc
\
CHPTY B*» WATER,.
'i us. mi
11 in mi u
;i i in inii
\ N
\x \
figure 13: Radiance vs Thickness
roughness acts as a depolarizer and converts some of the
incident vertically polarized return to horizontal and vice
versa. Each of the signal returns has amplitude and phase.
For the production of a Synthetic Aperature Radar(SAR)
image, however, only the phase of the return is required.
The phase data is recorded on film from a cathode ray tube
for later optical porcessing by which the SAR imagery is
generated. The tests performed with four frequency radar
indicate that it is possible to map the oil slicks in the verti-
cal polarization while the horizontal polarization is not
responsive. In the vertical polarization (VU) the presence of
oil on the synthetic aperature radar imagery is represented
by a dark non-reflecting area. This can be attributed to the
fact that within the oil areas the capillary.waves which are
required for backscatter are being damped. However, the
horizontal polarization (HH) and cross polarized com-
ponents give no indication of oil. This lack of apparent oil
detection by the horizontal and cross polarized components
is not a characteristic of the oil slicks as might be thought.
but rather a characteristic of slightly rough surfaces viewed
at shallow angles. Under such conditions, the horizontally
polarized radar cross section (RCS) is much smaller (6-20
db) than the vertically polarized RCS and the cross polar-
ized RCS is even much smaller.
9.7 API FUEL OIL
21.6 API CRUDE OIL
26.1 API "CRUDE OIL
#2 DIESEL FUEL
liiuia-14: Black & White Print of Thermal Imagery AH: 4000' Time: 1200.0 A- 9.3-11.7
-------
REMOTE SENSING OF SPILLS 81
J
NAUTICAL
MILES
RAMOS I 1320 GALLONS OF OIL
SANTA BARBARA AREA
29 OCT 70 (31)
VERT. POL., DEPRESSION ANCLE ~ 8'
AIRCRAFT ALTITUDE 2000 FEET
Figure 15: L-Band Imagery of Oil Slick on 29 October 1970
'
UHOS I
5AKTA BARBARA AREA
29 OCT «
1320 CALLOWS OF OIL
VERT. POL.. DEPRESSION ANGLE - 7*
AIRCRAFT ALTTTITDE 2000 FEET
Figure 16: P-Band Imagery of Oil Slick on 29 October 1970
In Figure 15 we have L-band imagery taken over the
test site on 29 October 1970 at 2000 feet. P-band imagery
taken at the same time is given in Figure 16. The oil image
in this case is compressed in the horizontal direction by a
factor of 2, and most of the resolution of the slick is lost.
This compression of the image in P-band is a scaling effect
of the radar.
Since the volume of the oil released in the spill was
known, it was possible to compute the average film thick-
ness which is given in Table 5, and Figure 17. The area of
o
-•
\e.
10
6
g
4
2
n
,
SANTA BARBARA AREA */ —
6 NOV 70 /•
660 GALLONS OF / •
API 26.1 CRUDE OIL *
CALM SEA /
LIGHT AIRS
—
_
/
/
x
L_r__J I
2.5
^
3 E
n
z
4 E
(A
5
6 £
0
10 v>
20
30
0 I 2 3 4
HOURS AFTER SPILL
Figure 17: Thickness of Oil Slick Versus Time
the oil slick was determined from the imagery by use of a
planimeter.
Ground Truth Data
The ground truth data collected during the course of
the experiment is given in Table 6.
CONCLUSIONS
Gulf of Mexico Experiment
Conventional aerial photography will provide positive
detection of oily mixtures discharged from vessels under-
way at normal speeds whenever the oil content of the dis-
charge is at least 1 GPM, regardless of sea conditions, illumi-
nation angle, or oil type.
Black and white photography is the preferred sur-
veillance tool. Color photography achieves slightly lower
detection thresholds than black and white, but the diffi-
culties in obtaining color prints with the proper balance and
contrast more than offset that advantage.
The detection threshold is significantly lower (>\/2
GPM) for heavier oils and crudes, particularly if the slick is
patchy or ropy in character. Down-sun and down-sea as-
pects further enhance contrast and aid detection, as does an
overcast sky.
The effect of ship speed on detection is limited to a
slight loss of contrast at higher speeds, due to increased
wake turbulence.
Southern California Experiment
Ultraviolet photographic techniques are considered to
offer great potential for detecting oil. The fluorescence
coming from the oil due to solar illumination is easily de-
tected.
-------
CO
c
•<
o>
1
Date Run Freq. Mean
No. Local
(1970) (MHz) Time
28 OCT 7 1228 0918
29 OCT 29 1228 0822
31 1228 0835
35 428 0904
6 NOV 78 428 1352
80 1228 1404
82 1228 1415
84 1228 1427
87 1228 1444
88 1228 1451
91 8910 1517
93 8910 1530
95 8910 1542
96 4455 1548
98 4455 1600
7 NOV 108 8910 1249
112 4455 1315
114 4455 1328
Large Oil Slick
Quantity Area Average
of Oil , ? Thickness
(gallons) (10eft ) (microns)
Diesel oil, API 34.1
Released 28 OCT. 0800-0827
330 -00.38 ~35
1320 48 1
57 1
43 1
Crude oil, API 26.1
Released 6 NOV. 1145-1230
660 1.0 26
1.9 14
2.9 9
3.2 8
4.0 7
7.3 4
8.4 3
9.2 3
11 2
10 3
10 3
Unidentified Oil Slick
660 21
18
23
Small Oil Slick
Quantity Area Average
of Oil , . Thickness
(gallons) (106fO (microns)
Crude oil, API 26.1
Released 28 OCT, 0840-0902
330 ~0.20 ~67
"The four spills of 28 OCT -
diesel (34.1), crude (26.1)
crude (21.6), #6134 fuel (9.7) -
_have merged into one slick.
#6175 fuel oil, API 9.7
Released 6 NOV. 1235-1315
660 "-0.2 ~130
0.86 31
0.82 33
0.86 31
1.6 17
1.4 19
1.7 16
1.5 18
1.7 16
1.8 15
2.0 13
Unidentified Oil Slick
660
3.7
5
-------
DATE
10/22
10/23
10/24
TIME
12:45
13:00
13:05
13:28
15:00
10:57
11:19
11:35
13:15
12:50
12 Diesel spill initiated
Diesel spill completed (330 Gal)
26.1 API spill Initiated
26.1 Spill completed (330 Gal)
21.6 API gravity spill initiated
21.6 Spill completed (330 Gal)
9.7 API gravity spill initiated
9.7 Spill completed (220 Gal)
One day aged 9.7 & 21.6 API
SEA STATE
(VISUAL
APPROX.)
0
0
0
0
0
0
0
0
0
0
WIND FORCE HATER
BEAUFORT TEMP.'C
SCALE
i
1
1
1
0
1
1
0
0
0
16.1
16.1
16.1
16.1
16,1
16.3
16.3
16.3
16.3
16.5
AIR
TEMP.'C
18
18
18
18
18
17
17
17
17
17
.2
.2
.2
.2
.2
.9
.9
.9
.9
.3
RELATIVE
HUMIDITY
*
80.0
80.0
80.0
80.0
80.0
75
75
75
75
67.0
BAROMETRIC SKY
, PRESSURE CONDITIONS
(MM H«>
768
768
768
768
768
763
763
763
763
764
Low thick
Low thick
Low thick
Low thick
Low thick
nigh thin
High thin
High thin
High thin
High thin
broken
broken
broken
broken
broken
scattered
scattered
scattered
scattered
scattered
10/28
3
3
D.
H
c
3-
10/29
10/30
11/6
11/7
11/8
12/2
12/3
gravity oil in two distinct
slicks
14:51 One day aged 9.7 & 21.6 API
gravity oil In two distinct
slicks
#2 Diesel spill initiated
#2 Diesel spill completed (330 Gal)
26.1 API Spill initiated
26.1 Spill completed (330 Gal)
26.1 API gravity spill initiated
26.1 Spill completed (330 Gal)
9.7 API gravity spill initiated
9.7 Spill completed (330 Gal)
08:00
08:27
08:40
09:02
09:08
09:35
09:49
10:20
12:20
14:48
16:11
07:40
08:40
11:30
14:57
16:09
09:00
11:30
13:00
14:26
11:45
12:30
12:35
13:15
12:30
16:00
09:00
11:00
13:30
13:55
14:43
15:00
15:40
13:20
15:30
16:00
The four slicks from 10/28
have merged forming one
large slick of irregular
shape 3 Ml x 4 Ml.
Same as 10/29
26.1 API gravity spill Initiated
26.1 Spill completed (660 Gal)
9.7 API gravity spill initiated
9.7 Spill completed (660 Gal)
One day aged 9.7 & 26.1 AFX
gravity oil in two discrete
slicks - 26.1 slick Is highly
streaked - 9.7 slick Is well
coalesced.
26.1 API slick had dlspersered
completely - 9.7 API slick has
taken on an elongated shape
.5x2 miles.
#2 Diesel spill initiated
#2 Diesel spill completed (660 Gal)
21.6 API gravity spill initiated
21.6 Spill completed
The two slicks from 12/2 have merged,
creating one large slick .5x6 miles.
At - Sea experiment terminated.
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
1-2
16.5
16.4
16.4
16.4
12.8
12.8
12.8
12.8
13.1
13.1
17.3
16.9
17.2
17.5
17.0
17.0
16.0
16.0
15.0
15.4
96.9
78
80
75.5
69
69
72.0
72.0
60.0
62.3
764
2
2
2
2
2
2
0
0
0
0
0
0
0
0
0
0
1
1
3
3
1
1
1
1
3
3
16,4
16.4
16.4
16.4
16.4
16.4
16.4
16.4
16.4
16.4
16.4
16.3
16.3
16.3
16.4
16.4
16.2
16.4
16.4
16.5
16.4
16.4
16.4
16.4
16.2
16.2
16.9
16.9
16.9
16.9
16.9
16.9
16.9
17.1
17.5
17.5
17.2
17.0
17.0
17.2
17.2
17.2
16.4
18.2
18.4
18.0
16.8
16.8
17.0
17.5
16.9
16.7
67
67
70.5
70.5
70.5
70.5
57.5
57.5
52.5
64.0
81.0
71.5
71.5
78.5
79.0
84.0
81.5
87.0
84.0
78.0
76.5
76.5
78.5
81.5
74.5
72.0
775
775
777
777
777
777
774
774
770
769
773
774
774
770
770
769
770
773
770
770
769
769
770
773
769
767
770
773
770
765
765
769
769
765
765
High thin scattered
Clear
Clear
Clear
Clear
Clear
Clear
Clear
Clear
Clear
Clear
Clear
Clear
Clear
Clear
Clear
Clear
High thin scattered
High thin scattered
High thin scattered
Clear
Low thick broken
Low thick broken
Low thick broken
Low thick broken
Clear
Clear
Clear
Clear
Clear
Clear
Clear
Clear
Clear
Clear
Clear
-------
84 OIL SPILL PREVENTION .. .
The optical-mechanical scanners such as infrared ima-
gers and the multispectral scanners are effective in detecting
oil slicks if they operate in the ultraviolet and blue, and 8
to 14 micrometer portion of the spectrum. Here oil fluor-
escence and oil emissivity can be used to provide detectable
differences. However, this approach is presently limited to
clear weather, i.e.,operates effectively only during clear sky
and daylight conditions.
Radar and passive microwave techniques appear very
promising. They show the best potential for providing ad-
verse weather coverage of large areas. A cursory amount of
data has been obtained to date for this technique in re-
ference to oil slick detection. Additional work in this area is
necessary to 'fully understand this technique's potential.
The mapping experiment performed in the Chedabucto Bay
area of Nova Scotia and the Southern California experiment
has resulted in synthetic aperture imagery in which oil
slicks are quite evident and well defined. Even though the
imagery was obtained on a variety of frequency/polar-
ization combinations, no signatures were identified which
could not be positively termed characteristic of the spill.
The use of radar in locating and monitoring oil contami-
nation on the sea surface has the advantage of rapidly
searching wide areas with good resolution under adverse
weather conditions. In general, there already exist sophis-
ticated models of radar scattering processes, and in parti-
cular, a fundamental understanding of the mechanism in-
volved in slick detection. The major liability of radar tech-
niques is the difficulty in obtaining real time processing.
Using passive microwave techniques, it is possible to
detect oil slicks on the open ocean. However, additional
work in this area is necessary, to fully understand this tech-
nique's potential. The additional work should address itself
to these areas: (1) Oil slick detection capability as a func-
tion of sea conditions. (2) Feasibility of estimating oil film
thickness from measured signatures. (3) Feasibility of
estimating oil film thickness from sensor characteristics.
Measurements to date indicate that a constant antenna view
angle of 30° to 45° produces the most favorable oil slick
signature. Depending upon whether or not the microwave
system is operating in the scanned or unscanned mode the
data obtained can easily be displayed on a strip television
monitor, facsimile machine, and/or strip chart recorder,
providing almost-real-time display capabilities.
REFERENCES
1. Detection of Oil Emission From Ships at Sea by
Observation from Aircraft, October 1969, Report No.
CRR/ES/15, Department of Scientific and Industrial Re-
search, Warren Spring Laboratory, for the Ministry of
Transport, United Kingdom.
2. Aukland, J.C., and Trexler, D.T., October 1970, Oil
Pollution Detection and Discrimination by Remote Sensing
Techniques, Report No. 714104/A/006-1 for the Applied
Technology Division, U.S. Coast Guard.
3. Guinard, N.W., and Purres, C.G., April 1970, The
Remote Sensing of Oil Slicks by Radar, Project No.
714104/A/004 for the Applied Technology Division, U.S.
Coast Guard.
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METHODS AND PROCEDURES FOR
PREVENTING OIL POLLUTION FROM
ONSHORE AND OFFSHORE
FACILITIES
R. D. Kaiser and H. D. Van Cleave
Water Quality Office
Environmental Protection Agency
ABSTRACT
Presention-the first line of defense against oil pollu-
tion-requires a well planned program for the implementa-
tion of fail safe design criteria and operating procedures,
personnel training, and reliable detection and safety equip-
ment. This paper summarizes current pollution prevention
practices in the production and development of oil and
associated appurtenances both onshore and offshore and
possible future developments of prevention technology.
The discussion of onshore activity will focus on the
Colorado River Basin which covers approximately one-
twelfth of the continental United States. Within this vast
area there are approximately three hundred producing oil
and gas fields. An oil pollution control program related to
oil and gas exploitation will be discussed.
In the beginning the Program's primary emphasis was on
the drilling activity. Field inspections were made on all
drilling sites in the States of Colorado and Utah. The
second phase of the program dealt with periodic field
inspections of the 300 oil and gas fields with attention
given to the overall housekeeping, well head leaks, gathering
lines, and tank bettery operations including the use of
slammer ponds.
Offshore oU and gas production and development has
generally been conducted in water depths of less than 300
feet. However, indications are that offshore technology is
advancing to the point to not only drill, but also to produce
in water depths reaching 1000-1300 feet. As offshore oil
and gas operations move ever seaward operators are
encountering increasing well pressures and other forces and
stresses to control. These increasing pressures, natural
forces and conditions coupled with "multiple-use" plat-
forms containing "multiple completion wells" present a
"multiple challenge" to design engineers in preventing
uncontrolled flow from a well. Single fixed structures with
a capability of supporting the drilling of from 20 to 60
wells directionally presents a costly structure vulnerable to
total loss if one well flows out of control. Therefore, a
sound "safety-in-depth " approach should be standard pro-
cedure for not only the driller but also the production
foreman if we are to prevent oil spills from uncontrolled
wells. The discussion of offshore facilities will review
generally the present safety devices, methods, and pro-
cedures for controlling well flow.
Procedures and equipment for prevention of oil spills
during drilling, production, and development are described;
their existing applications summarized, and the potential
for future developments is given. The equipment includes:
blowout preventers, surface and sub-surface safety devices.
Practices for the use of curbs, dikes and catch basins; flood,
hurricane and fire control procedures are examined from
the viewpoint of oil spill prevention. The role of design
criteria, personnel operating procedures, and human error
in spill prevention are discussed, and future practices are
postulated.
INTRODUCTION
Onshore and offshore wells represent 84% and 16%
respectively of the world's current oil production. The
current aggregate offshore reserves of 85 billion barrels
represent approximately 20% of the world's total reserves.
Within the United States, approximately 10% of the current
oil production is offshore. The U.S. Department of the
Interior estimates that by 1980, approximately 30% of the
U.S. oil requirements will come from our offshore re-
serves. l
U.S. oil production in open unprotected waters began as
early as 1938. Increasing oil demands, technological ad-
85
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86 OIL SPILL PREVENTION...
vances and economic and political factors have led to a
total U.S. production increase in offshore oil and gas
production from less than 1% in 1954 to approximately 9%
in 1969.2
There are many similarities between onshore and off-
shore exploration, drilling, completion and production
technology and practices; however, environmental and
economic factors have also created significant differences in
these phases of petroleum operations. For example, the
limited space of offshore facilities has resulted in standard
operating practices of multiple drillings and completions
from single facilities. Also, separation of oil and water in
the production of oil may utilize different equipment or
procedures. Similarly, the potential of water pollution due
to oil or brine water is different in offshore than it is in
onshore facilities, and therefore, it seems reasonable to
expect that pollution prevention and control practices will
differ.
In this paper, we will describe an onshore pollution
prevention and control program that was established in a
regional oil production area. This program will be presented
in a case study format, emphasizing prevention and control
methods and procedures that are peculiar to onshore oil
operations. We will phase into offshore drilling and produc-
tion by pointing out some similarities in well control
methods and procedures during drilling operations both
onshore and offshore. A description will follow of the
complexities of offshore drilling and production that are
peculiar to offshore operations and how these complexities
require more detailed considerations in establishing an
offshore pollution prevention program. By this comparison
study, we are attempting to demonstrate the need to more
thoroughly examine requirements for offshore pollution
prevention and control if we are to prevent the potential
economic and ecological losses accompanying offshore
drilling and production mishaps.
Onshore Prevention and Control Program
On November 3,1967, the Utah Water Pollution Control
Board requested the Federal Water Pollution Control
Administration, now known as the Water Quality Office of
the Environmental Protection Agency, to evaluate the
pollution effects connected with the disposal of oil field
brine water.
This was not the first time that Utah was aware of water
pollution problems associated with oil production. The U.S.
Geological Survey already had engineers in the field
supervising drilling and production. However, since Utah
only had one U.S. Geological Survey engineer assigned to it
and Colorado only had two, it was impossible for such a
small force to also investigate for water pollution at well
sites.
In order to answer Utah's request for assistance, FWPCA
began to provide technical assistance to the State and the
U.S. Geological Survey. Firmer contorl over oil associated
water pollution began to take effect.
It soon became apparent that because of the extensive
oil exploration and production in the States adjacent to
Utah, this field survey project was extended to include all
of the Colorado River Basin—an area which covers approx-
imately one-twelfth of the continental United States. This
program not only dealt with prevention of oil pollution but
with other wastes associated with oil exploration—such as
oil field brine water disposal. It is interesting to note here
that this voluntary program was started in the fall of 1967,
well before the passage of the Water Quality Improvement
Act of 1970.
The first phase of the program dealt with the drilling
activities within the Basin. The Colorado River-Booneville
Basins Office of FWPCA received notices of intention to
drill from the States of Utah and Colorado. These notices
listed the name of the well, the location and depth
expected and the company drilling the well. The notices
were received weekly and an average of 30 wells were
announced each month, including not only development
wells, but also wildcat wells.
The locations of over 200 well sites were plotted on
USGS 7 1/2 minute quadrangle maps. Approximately 40%
of these were within one mile of the nearest perennial
stream into which oil or wastes could be discharged. These
sites, in addition to another 10 randomly selected sites,
were inspected to determine the measures that were being
used to protect the environment from oil spills.
Approximately 25% of the sites visited had the potential
for pollution problems. The field visits considered all
aspects of potential pollution problems, including selection,
access, layout and construction of the site.
The site selection for development wells was set on a
specified acreage pattern. Several sites were in the flood
plain of streams known to have a great potential for flash
flooding during certain seasons of the year. In these cases
consideration was given to the length of time the rig would
be on the site and the protection measures provided for the
site, hi addition, it was suggested that drilling contractors
remove all liquids from the pits after completion of the well
to insure that later floods would not wash this material into
the stream.
The most common problem encountered at individual
well sites was the location of the mud pits. These pits were
often located in the stream bed, particularly if it was a dry
wash. During the flash flood season these pits were
vulnerable and the contents could easily be washed into the
nearest perennial stream. Another problem resulted from
air drilling operations. Pits for the cuttings were not used
and the cuttings, liquids, and detergents were discharged
onto the surface of the ground.
Many of the problems uncovered in the field visits were
quickly remedied by the drilling engineers, drilling contrac-
tors, and on many occasions by the USGS who administers
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METHODS AND PROCEDURES ...
87
oil and gas operations on Federal lands. An important facet
of this program was the educational value it carried. The
program made the drilling engineer, his company and the
drilling contractors aware that consideration should be
given to protection of the environment in the selection and
development of drilling sites. The results of this inspection
and review program were shown by a decrease in improper
site location and construction.
In addition to the regular well site activity, a search for
old abandoned wells which were leaking oil, water and gas
was also undertaken. When these were found a program for
preventing oil or other wastes from entering a water course
was established. One typical program was developed for the
plugging of the Cane Creek wells below Moab, Utah. These
wells had been discharging brine and oil into the Colorado
River. Preliminary investigations revealed that these wells
kd been drilled during the 1920's and 1930's. Two of the
wells had a history of high pressures and one well was
reported to have "blown-in" during the drilling, resulting in
an oil slick affecting most of the Colorado River with some
oil reaching the Gulf of California. Other information from
the well logs also indicated potential for an oil discharge to
the river.
These wells were located on the bank of the river and
were butted up against a 500-foot cliff. This was the last
location on the river where adequate oil pollution control
measures could be constructed before the river discharged
into Lake Powell. Based upon this information, the FWPCA
and the State of Utah agreed that the following measures
should be used to prevent oil from entering the Colorado
River:
1. Skimming ponds be constructed to skim oil from the
surface of the water before discharging the water to the
river.
2. A perimeter dike be constructed around the wells and
the skimming ponds.
3. Emergency pumping equipment be available to re-
move excess oil from the skimming ponds if necessary.
4. A boom be constructed across the Colorado River
downstream from the well sites and that straw would be
available to absorb the oil.
The first three measures were implemented by the State
of Utah. The boom was not used since available booms do
not work effectively in velocities such as encountered in the
Colorado River. Construction of an open fence-type boom
was considered too costly. The wells were successfully
plugged, thus resulting in the elimination of oil and brine
from the river.
Another phase of the program centered around inspec-
tions of the approximately 300 oil and gas fields within the
upper Colorado River. Attention focused on the disposal of
produced waters to the prevention and control of oil spills.
The survey indicated that produced water, which varies in
dissolved solids concentrations from less than 1000 mg/1 to
more than 250,000 mg/1, was disposed of in evaporation
pits, discharged to streams or injected into the ground.
During 1969 approximately 165 million barrels of water
were produced in the Colorado River Basin of which
approximately 25% used surface disposal methods. Approx-
imately 98% of this surface disposal was in Colorado and
Utah. During the inspections it was found that housekeep-
ing practices at most of the fields were not adequate. There
was evidence of oil around well heads, tank batteries, along
gathering lines and in the dry washes and stream banks. Oil
spills had occurred throughout the fields, indicating the
apparent lack of concern and/or training of personnel who
operated the field. Containment or cleanup of such spills
was minimal and oil was carried into streams by the heavy
runoff.
Two of the most common potential problem areas for
oil spills were the placement of gathering lines and the
diking of tank batteries. The gathering lines generally
consisted of small diameter steel piles laid on the surface of
the ground and were vulnerable to breaks caused by heavy
equipment. The pipes meandered across the ground, cross-
ing dry washes or streams, and were subject to breakage
during heavy runoff. Since these gathering lines were not
generally equipped with automatic shutoffs, a break could
p6rmit oil to be pumped into surface water courses for long
periods of time before being discovered. In some fields,
however, consideration of the location and protection of
these lines was evidenced.
Very few of the oil fields surveyed had dikes around the
tank batteries. This in itself presented a great potential for
oil spills since many of these tank batteries were perched on
hills above dry washes or streams. The inadequate house-
keeping and the lack of diked facilities were pointed out to
field operators and agencies as sources of oil pollution.
Results were minimal.
These surveys again proved valuable by making the
various companies and government agencies aware of the
potential for oil spills and the methods and procedures
which can be used to prevent such spills. Although
immediate action to remedy potential pollution problems
was not observed, it was felt that this program provided an
approach which could ultimately be utilized by agencies
and field operators to prevent oil spills.
The major success of this onshore program was in the
greater awareness for pollution control in oil exploitation
shown by personnel from the various companies and
agencies, and in the placing of the responsibility for
pollution prevention at the earliest point in the oil
production cycle.
Offshore Well Control
A desirable well control and pollution prevention pro-
gram must begin before a well is drilled and continue until
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88 OIL SPILL PREVENTION...
the producing formation is played out, and the well is
successfully plugged and abandoned.
Much of the technology of controlling wells offshore is
derived from onshore methods and procedures, particularly
during drilling operations. The same care and detailed well
planning is required regardless of well location. The
engineer and geologist must plan the well based on the
depth of the geologic formation, the estimated pressures,
and other considerations. During drilling, equipment or
environmental mishaps that could occur require careful
blowout and pollution prevention planning. Every foot of
hole made by every rig presents the possibility of a
blowout.
Generally, the necessary blowout prevention procedures
utilized onshore are used offshore. The function of drilling
muds are common both onshore and offshore. Essentially,
drilling mud cools and lubricates the drill bit, carries drill
cuttings to the surface, stabilizes the walls of the hole and
by increasing the weight of the mud in the fluid column,
becomes a safety method to control hole pressures.
Likewise, casing is used during drilling operations on and
offshore as an important part of the blowout prevention
plan. Casing has the extremely important safety function of
shutting out high pressure zones and stabilizing the well.
Blowout preventers are used as a surface safety device when
drilling or when the drill string is out of the hole. Usually
blowout preventers are tailored to meet the particular
requirements of the well. Blowout prevention equipment
used in drilling must meet rigid standards, particularly when
working with extremely high pressures. This equipment,
once installed, is frequently tested to assure that it will
function properly during an emergency situation. Both
onshore and offshore drilling crews practice emergency
shut-down procedures to make sure they all understand
what to do when emergency action is required.
However, despite the technological advances in casing
design, pumps, drilling fluids, blowout preventers, sub-
surface safety devices, computer applications for estimating
well conditions, and better training of operating and drilling
crews, blowouts still occur and in some cases coRtffbiite to
large amounts of oil being discharged into the environment.
To suggest a standardized prevention and control system
to control all wells during drilling operations onshore and
offshore would be impractical. Well control problems are
unique to each well and require individual attention, even
though this specialized or customized attention for each
well drilled requires much more planning effort when
moving offshore into a marine environment. Additional
planning effort is required because of the added stresses and
forces associated with marine operations, and other envi-
ronmental considerations. There is a distinct difference in
the method of operation offshore as compared to typical
onshore procedures. Onshore drilling and production are
sequential and separate, whereas offshore drilling and
production can occur together on the same platform. This
is not to suggest that blowouts are occurring more
frequently offshore than onshore. On the contrary, the
safety record offshore is exemplary. However, when one
reviews records of successful completions it becomes clear
that considerable planning and investment was made in well
control procedures and equipment before the first foot of
hole was drilled. The thousands of successful completions
are basically a result of balanced drilling with prevention
and control programs planned in depth.
The technology for deep water production is relatively
new. Offshore production of oil to date has been accom-
plished in water depths of less than 350 feet with the bulk
of offshore facilities in water depths of less than 100 feet.3
While it could generally be concluded that shallow water
production of oil has been somewhat successful, it does not
necessarily follow that deep water operations will enjoy the
same high degree of success. As offshore production moves
into deeper water, conventional production safety devices
now in use may not be adequate to control up to 200
producing wells 'on one platform. Ocean Oil recently
announced development plans calling for installation of a
drilling and production platform in 700 feet of water, five
miles offshore in California. As many as three drilling rigs
could be installed on the deck for drilling up to 60 wells
directionally.
It would seem from the foregoing that improved or
non-conventional safety devices and spill prevention pro-
grams need to be examined in light of the planned
mammoth multi-purpose platforms. The onshore drilling
and production site presents one well with essentially one
problem. However, when offshore, the one well problem
could rapidly become a multiple well problem. Further-
more, the risk for environmental damage increases and the
quantity of oil which could be spilled becomes greater;
therefore, the costs are expected to be greater. Hence, the
increased investment in prevention and control must be
accepted.
An example of this cost can be demonstrated by a recent
offshore catastrophe reported in Ocean Oil Weekly Report.
"Approximately 60 men were working on the platform at
the time the fire started. Four men died and 37 were
hospitalized as a result of the accident. The burning
platform contained 22 wells (21 duals and 1 single), was in
water approximately 55-60 feet deep and was valued by
some sources around SI2.5 million. Although the cause of
the accident is not known, it was not a blowout. It is
believed that the initial explosion and fire started with a
producible well that was being worked over by a wireline
company at the time. . . . naturally, since the well was
being worked on there wasn't any down-hole safety valve
installed." The subsequent cost of several relief wells plus
the cost of cleanup suggests that the cost of additional
safety equipment and improved operating procedures re-
quired to control the well become insignificant when
compared to the loss suffered.
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METHODS AND PROCEDURES ... 89
What new technology is available or is under develop-
ment that can be utilized for offshore prevention and
control problems? It is standard practice to position well
head safety devices on the ocean floor when drilling from
floating rigs. The experience and technology from such
underwater practices has expanded to include underwater
completion and production. Improved varying, manifolding
and surface-to-ocean floor communications have contrib-
uted to successful completions in shallow water. Existing
underwater technology is being applied in the further
development of underwater oil completion and production
practices for deeper water.
Humble Oil is developing a submerged production
system (SPS) including subsea well heads, manifolding, and
control and safety devices and equipment. A full-scale SPS
system is now being developed. We are looking forward to
the field testing and the success of this project.
Some advantages of underwater completions and pro-
duction are:
Less converging or consolidation of flow lines to one
centralized platform
Less vulnerability to hurricane damage
Less potential hazard to navigation
Less chance of fire or explosion
Less chance for debris to intefere with killing operations
Other improvements are also reported in sub-surface
safety devices.4 There are available as standard items direct
controlled and remote controlled sub-surface safety valves
that can be installed in most wells, regardless of original
down hole design. The concept of redundant sub-surface
safety valves should be considered in pollution prevention
planning. However, when redundant varying cannot be
installed there is a tubing removable ball-type safety valve
available that contains some excellent features that provide
back-up controls in the event of failure to activate. This
valve operates on a hydraulic pressure, piston principle and
is controlled from the surface by a control manifold.
Monitor pilots detect loss in hydraulic pressure. Should the
valve fail to close it could be closed at the surface
manually.5
There are also improvements in surface safety valves that
can be automatically shut-in by pilot signals due to
high-low pressure sensors, fire, liquid levels, and tempera-
tures. In addition, there are remote/direct control valves
sensitive to well conditions that can be tailored to the
peculiar conditions of a given facility.
SUMMARY
We believe that an effective oil spill prevention program
can be accomplished for oil well drilling and production
both onshore and offshore. However, the unique facilities
and environmental conditions that exist offshore deserve
special attention if oil spills are to be reduced and
environmental damage minimized. A sound safety-indepth
or fail-safe approach should become standard procedure in
offshore drilling and production. These standard procedures
would apply to the production foremen just as they apply
to the driller or the tool pusher. Many of the offshore
platforms today are multiple use structures that support
not only multiple producing wells but also drilling rigs for
simultaneous drilling operations. As these complex offshore
facilities move into deeper water more consolidation and
unitization should be expected. Therefore, the increasing
complexities of such structures present a distinct challenge
not only to the design and safety engineers, but also to the
environmental engineer.
REFERENCES
1. International and National Regulation of Pollution from
Offshore OB Production. Robert B. Kruiger. From a paper delivered
at a conference on International and Interstate Regulation of Water
Pollution, March 13, 1970, Columbia University, New York, New
York.
2. Petroleum and Sulfur on the U.S. Continental Shelf. U.S.
Department of the Interior. December 1969.
3. Ibid.
4. Ocean Oil Weekly Report. December 7,1970.
S. Safety Equipment that can help Prevent Pollution. Odis
Wilder. From a paper delivered to the American Society for
Petroleum Engineers, November 1970, Lafayette, Louisiana.
6. Ibid.
GENERAL REFERENCES
Economics of Oil and Gas Operations Offshore, U.S.A. R.C.
McCurdy, President, Shell Oil Company. May 1969.
Louisiana Oil and Gas Facts. Eleventh Edition, Mid-Continent Oil
and Gas Association.
Offshore Petroleum and the Environment. Staff paper prepared
by the Committee on Public Affairs, American Petroleum Institute,
October 6,1969.
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EMBROILED IN OIL
Harold Bernard
Agricultural and Marine Pollution Control Branch
Division of Applied Science and Technology
Environmental Protection Agency
ABSTRACT
The fate of used automotive crankcase oils are analyzed.
It appears that current methods for handling waste oils
dispose of about 0.5 billion gallons per year directly to the
environment. Burning tests using the waste oils for fuel oil
produced mixed results. Some tests indicated a 3:1 dtlht-
tion ratio could provide adequate results; other tests
indicated coking of fire tubes and clogging of burner
nozzels. A novel rerefining flow sheet which uses vacuum
distillation without clay treatment or chemicals to produce
a No. 2 and No. 4 fuel oil is presented. Additional research
and development is required, but the process has a potential
for about an 85-90% yield without producing any solid or
Squid pollution.
INTRODUCTION
All of us, the entire nation, are embroiled, not only in
oil but in the quality of our environment, en toto. No
longer can we be concerned solely with production effi-
ciency as it is related to maximizing unit output at lowest
cost. We must now consider as part of the production
processes, the ultimate fate of the product we produce. A
good case in point is the use of detergents. It was the
panacea for cleanliness. But look what it's doing to our
rivers and lakes. It's accelerated their rate of aging from one
of geologic time to only years. Many states have already
regulated against the further use of phosphates in deter-
gents.
Both industry and the government are involved in
research to try to find a substitute that is effective as a
detergent but at the same time does not detrimentally
affect any segment of the ecological cycle to an extent that
is unacceptable to the public.
Are we getting ourselves in the same dilemma with waste
crankcase oils? How many of you have given any thought
after you leave the service station to what happens to your
automobile crankcase drainings after you leave? As is our
nature-"out of sight, out mind". However, that conception
can no longer be tolerated.
Two recent messages from the President of the United
States paid particular attention to oil pollution and to a
need for recycling a hitherto considered waste product. The
President's message to the Congress proposing Administra-
tive and Legislative actions on May 20, 1970, was stated in
relation to oil pollution from ship transportation, but you
may be able to relate it to oil pollution in a broader sense.
It began with "the oil that fuels our industrial civilization
can also foul our natural environment.
"The threat of oil pollution from ships-both at sea and
in our harbors—represents a growing danger to our marine
environment. With the expansion of world trade over the
past three decades, seaborne oil transport has multiplied
tenfold and presently constitutes more than 60 percent of
the world's ocean commerce.
This increase in shipping has increased the oil pollution
hazard. Within the past ten years, there have been over 550
tanker collisions, four-fifths of which have involved ships
entering or leaving ports. The routine discharge by tankers
and other ships of oil and oily wastes as a part of their
regular operation is also a major contributor to the oil
pollution problem.
"The development of world commerce and industry and
its growing dependence on oil need not result in these
added dangers. The growing threat from oil spills can be
contained not by stopping industrial progress—but through
a careful combination of international cooperation and
national initiatives."
91
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92
OIL SPILL PREVENTION .. .
The message continued and outlined a number of actions
which the Congress should take to reduce the risks of oil
pollution.
It included international conventions, development of
standards, a Ports and Waterways Safety Act to control
navigation, traffic control, cooperation of private industry,
a broad program of research and development, licensing,
charging the spiller for oil pollution cleanup, and increased
surveillance. The President further noted that "many of
these (oil) spills result from willful violations of laws which
limit the discharging of oil. Such spills can be reduced by
more stringent surveillance procedures."
Another recent message from the President to Congress
related to recycling of junked automobiles. It stated, "The
particular disposal problems presented by the automobile
are unique. However, wherever appropriate we should also
seek to establish incentives and regulations to encourage the
reuse, recycling or easier disposal of other commonly used
goods." Let me repeat that last sentence for emphasis.
"However, wherever appropriate, we should also seek to
establish incentives and regulations to encourage the reuse,
recycling or easier disposal of other commonly used
goods."
This concept relates directly to waste oils, but we have
done precious little, if anything in this area. For example,
sales of automobile and industrial lubricating oils is now
approximately 2.5 billion gallons per year. It is estimated
that approximately 50 percent of this oil is not consumed
and is drained periodically to be replaced with new oil.
What happens to the 1.25 billion gallons that are drained
annually? An attempt is made here to ascertain the current
fate of this oil.
But before I proceed, let me say that I am not concerned
here with a presentation of absolute values, but only with
portraying the pollution potential of the problem.
A report by the State of Massachusetts on distribution
of waste oils was utilized by the American Petroleum
Institute to extrapolate the problem on a national scale.
A.P.I, indicated a national pollution potential of
approximately 450,000,000 gallons annually. The
distribution and sources are indicated in Table 1.
Table 1
Fate of Waste Oils*
Use % Volume-Gal/Year
Reprocessed for reuse 37-40% -5 billion
Road oil use 12% 150 million
Farm Use 3.0% 40 million
Dumped on ground 23-25% 300 million
Dumped into sewers 1% 12 million
Fate unknown 18-20% 250 million
*Based upon draining of 1.25 billion gallons per year
As the distribution of waste oils for the aforementioned
use may be the antithesis of environmental protection,
permit me to amplify on this for each of the above "Use"
categories.
In the category, "Reprocessing of the Waste Oils for
reuse," I have included rerefining of oil as well as use of
settled oil for fuel. In the current state of the industry,
about 30% of the oil ends up as an acid sludge. That's
equivalent to another 30 million gallons/year requiring
disposal. Add to that the unknown mountains of spent oily
clay used to clarify the product. Many states now refuse to
permit these sludges to be disposed of in sanitary land fills.
The industry has no sludge burner such as we recently
developed and demonstrated by the American Oil Company
in a joint project with the Water Quality Office of the
Environmental Protection Agency.
Where can all this sludge go? Where will it end up in the
environment? Last November, a large rerefmery in Pennsyl-
vania experienced a disaster. Lagoons holding the bottoms
sludges, gave way, venting 3 million gallons of oil waste to
the Schuylkill River. The company involved elected to
cease operations. Bankruptcies and shutdowns have de-
creased the industry's capacity from about 300 million
gallons/year in 1966 to about 100 million gallons per year
in 1971. Waste handling costs is the reason this industry is
experiencing an increasing rate of plant shutdowns. What's
happening to the oil?
Another use for the waste oil is to recycle it for a fuel.
The American Petroleum Institute presents some evidence
that if the waste oils are diluted with virgin oil, it may have
little or no detrimental affect on burner operation and
maintenance. However, let us take a real hard look at the
potential problems that could confront us from this use.
Tests performed by the Petroleum Rerefiners Association
indicate that waste crankcase oils contain huge quantities
of metallic pollutants as described in Table II: Pounds of
combustion products as Oxides per 10,000 gallons of waste
crankcase oil.2
Tests performed by National Oil Recovery Corporation,
a grantee of the Water Quality Office of the Environmental
Protection Agency, plus analyses conducted by oil com-
panies on both industrial and residential fuel burning units,
indicate that the waste oil can contribute to a buildup on
heating surfaces of hard thick deposits accumulated in a
relatively short time as well as a slow buildup of metallic
oxide films akin to those formed by high temperature flame
spraying processes. Needless to say, such deposits incur
significant maintenance costs and detract from the burning
concept.
Though I haven't gone into an indepth consideration of
the air pollution and air transported health problems that
can be considered when burning a fuel with the large
quantity of metallic pollutants noted in Table II, there is
evidence in the literature to indicate that under certain
conditions of burning, some of the impurities could
constitute a health hazard, or could necessitate additional
-------
EMBROILED IN OIL 93
effluent handling features such as high discharge stacks, air
cleaning equipment, monitoring or specific limitations as to
location of industry complexes that may burn this type of
fuel oil. Even if one were to assume that proper ratio could
be found that would preclude some of the above mentioned
problems the current industry modus operand! is the
antithesis of requisite management practices. The API
recognizes that the used oil is picked up by scavengers or
collectors. What do these collectors do with the oil? They
can either sell it to fuel oil suppliers, or sell it as a fuel
themselves. In either case how can one be assured that the
oil will be utilized in the I-to-3 ratio prescribed in the API
report and in any other proper ratio? How can such a
system be enforced without bringing public agencies into
the picture? Figure 1 is an example of the results of using
crankcase oil as a fuel without proper safeguards. These
clinkers were taken from a fire tube boiler that used
undiluted waste oils. Even with proper mixing safeguards,
the long-term effects of the use of this oil are unknown. As
seen from Table II significant quantities of metals are in the
waste oil. What happens to these in the burner irrespective
of their concentratipn? If it's anything like flame-metal
spraying, will the unsuspecting individual homeowner who
is the recipient of this oil have his maintenance costs
skyrocket? Can recycling of waste oils directly as a fuel be
realistically adopted without the manufacturer of the oil or
the user becoming responsible for its ultimate fate, or
without public regulations and proper enforcement? This
area is under study by both industry and the Water Quality
Office of the Environmental Protection Agency.
Figure 1
The report extrapolates that 150 million gallons of oil
may be used as road oil. Is this the right type of oil for this
purpose? It is high in emulsifiers and low in asphaltics. If it
rains soon after the oil is applied, does the oil emulse off
the roadbed into drainage ditches and into streams? What
percentage of the 150,000 gal/year of road oil ends up in
receiving waters? Then there is the 300,000,000 gal/year in
the category which is dumped on the ground at the source.
What part of this runs off to sewers, drainage ditches and
streams? What of the 250 million gallons per year whose
fate is unknown? If this volume were redistributed back
into the previous three categories in accordance with these
present percentages about 50 million gallons of waste oil
would get back to the environment.
And ladies and gentlemen, it does get back into the
environment. We polled our Regional Directors; they
indicated that used oil dumped into sewers, rivers and
harbors is a serious problem in their regions.
From this analysis it is conceivable that half a billion
gallons of oil are being discharged to the environment in an
uncontrolled manner.
This then is the current status!! What of the future??
"Trends" summarized by the API in the same report
indicate that the insult to the environment from used oils
may increase substantially in the near future. They project
a substantial decline in free pickup services with costs of
pickups being $5.00 & up. Will the user pay for pickup or
will he conveniently dispose of it himself to save a couple
of bucks?
The API report also projects "considerable diminution
of rerefming activity, and a growing tendency of scavenger
firms to go out of business." Triplex, a large rerefiner in
Long Island was reported in bankruptcy last year. The
previous winter two others in this geographic area also went
bankrupt. How many more will bite the dust?
The API further states that pickups, where available are
sometimes being made by uncontrolled "gypsy" operations.
"These include septic tank pumpers and a wide assortment
of truckers, including a few irresponsible, unknown, and
unreliable operators, who may take the oil to city dumps,
open fields, or other locations from which a portion of the
oil may find its way into streams, lakes, and fields." Yet if
these entrepreneurs do not pick up the oil, who will? With
rerefmers going out of business, will the collectors follow
suit? If their numbers decline, what will happen to the oil?
Rerefmers are reluctant to accept oil from "gypsies." The
main reason given in the API report is mixing of different
products and chemicals. Regardless of the reasons, this
indicates that oil that was picked up may not end up at a
rerefmery, or there will not be a sufficient number of
rerefmers to service the industry.
Burning is recommended by the API as the method that
should be emphasized for used oil pollution control. Again,
who will collect it and how will it be monitored for quality
control?
Remember, don't concentrate on the numbers I've
spewed out, just recall that they most likely are in the
hundreds of millions of gallons of oil; that 100 gallons of
oil can easily form a slick in a river that will require
significant efforts to clean up; and that the clean up costs
may be of the order of $1,000. That's $10 per gallon for a
-------
94
OIL SPILL PREVENTION . . .
Table 2.
POUNDS OF COMBUSTION PRODUCTS AS OXIDES
PER 10,000 GALLONS OF WASTE CRANKCASE OILS2
Zinc
Copper
Aluminum
Barium
Calcium
Nickel
Chromium
Iron
Silicon
Lead
Tin
Phosphorus
Boron
Magnesium
Total
Jackson Okla. City
Miss. Oklahoma
36 46
1.1 0.9
4.6 5.1
43 25
136 220
0.2 0.3
2.6 2.9
34 32
29 22
650 650
0.6 0.6
225 225
3.6 3.6
23 10
1188.7 1243.4
Washington Doraville
D.C. Georgia
58 33
1.4 1.2
2.6 5.1
57 20
162 131
0.3 2.4
4.8 1.5
17 30
13 24
400 570
0.6 1.0
255 211
2.8 4.3
23 36
997.5 1070.5
San Carlos Dearborn St Louis
Calif. Midi. Mo.
54 45 32
1.6
4.4
31
220
0.5
3.i
28
24
480
0.9
173
3.6
19
1043.8
Norco Rerefining Costs3 Table
Feed
Run# (Gal.)
4 176,288
5 228,324
Total 404,612
Product
Bottoms
Hvy.
Lt.
Barometric
Gasoline
Fuel, Loss (H2O)
Bottoms
(Gal.)
67,850
47,360
115,210
Total Gal.
#4 and #5
115,210
149,000
84,066
22,000
1,776
32,560
Hvy. Lt.
(Gal.) (Gal.)
46,700 44,475
102,300 39,591
Baro.
(Gal.)
22,000
149,000 84,066 22,000
Combined Yield
of #4 and #5
28.4
36.8
20.8
5.5
0.5
8.5(F)
1.4 1.2
4.8 4.5
9.3 33
147 120
0.6 0.3
2.6 2.2
36 32
27 64
720 650
1.0 0.9
264 189
5.9 3.6
31 25
1295.6 1157.7
3:
Gas
(Gal.)
863
913
1,776
Yield %
#4
38.5
26.5
25.2
Houston
Texas
32
1.3
4.4
45
162
0.9
2.9
30
19
570
1.3
189
3.8
61
1122.6
Fuel Water
Loss
16,400
16,160
32,560
Lyons
111.
44
1.5
6.3
38
168
0.7
1.2
42
24
650
0.9
173
5.9
25
1180.5
Yield %
#5
20.7
44.9
17.3
9.6
TOTAL DIRECT COSTS (Runs #4 and #5) per gallon
DIRECT COSTS $ 16,240.77 =
.0401 /gal. processing costs )
FEED CHARGE 404,612 )
TOTAL FIXED COSTS
$1,226.58 =
.003/gal. processing cost)
404.612
-------
EMBROILED IN OIL
95
waste product that costs of the order of 5 cents per gallon
to dispose of in an acceptable manner. This then is the
magnitude of the waste oil problem.
In our opinion there are two or three possible methods
for solving this vexing problem. They all involve recycling
of the waste oils.
Recycling for Fuel (without re-refining)
This method is feasible, but not in the manner proposed
in the API report. Considerable research is still required to
determine the constraints necessary to make burning of
waste oils acceptable. The burning tests that were con-
ducted on the large industrial furnaces should be repeated
for smaller burners, such as the homeowner types. Long
term effects should be noted. No matter how successful
burner tests are, the institutional modifications required to
make this concept practical will not be quickly available.
Who will follow the fate of the oil? How will proper mix
ratios be enforced? These are really the critical paths that
will determine the success or failure of this concept. Who in
each political subdivision will be responsible for enforce-
ment? These are real institutional problems that must be
faced squarely and resolved on an individual basis. Except
for the expanded burning testing program suggested,
actions necessary to make this approach effective Ire
confined almost exclusively to the political arena. This
avenue is always a long time in coming.
In my book, then, burning of waste oils cannot be an
approach that can be expected to produce effective and
desirable utilization of waste oils in the 70s.
Pickup by distributors of Virgin Oil
The institutional problems envisioned for the hetero-
geneous pickup system noted above can be eliminated if the
oil distributor picks up the waste oil himself-sort of the
way the soda-pop distributors do for empty returnable
bottles. This method is also fraught with problems:
1. It is more costly.
2. The majors would have to modify:
a. Distribution and collection methods and equip-
ment.
b. Bulk storage facilities at local depots.
c. Bulk shipment to refineries or burner installations.
d. Proportional distribution for refinery runs to
handle the waste oils with virgin oil refining.
e. Special runs or facilities for handling this type of
oil.
The problems would be unique for the majors as waste
oils volumes are relatively small when compared with the
millions of gallons put through a large refinery. Although
these problems can be solved relatively easily, the total
problem of collection and disposal of waste oils would still
require extensive institutional reforms to resolve such
questions as the fate of oil received by independents,
garages and terminals and the relationship of sales of oil in
retail outlets that permit individual automobile owners to
service their own cars. What do these fellows do with their
drainings? Should these retail outlets be permitted to sell
oil without accepting waste oils in return? Or should oil be
permitted to be sold only by those who have adequate
drainage and storage facilities? Unless these other institu-
tional problems are resolved at the same time as oil pickup
is instituted in all likelihood the oil problem will still rank
high in pollution potential.
Rerefining of Waste Oils
If for no other reason than it appears to be readily
attainable in a year or two, waste oUs can and should be
"economically" rerefmed and recycled into the competi-
tive market place to be reused or consumed in an
acceptable manner. I believe we are part way there, as
exhibited by our project in Bayonne, New Jersey, with the
National Oil Recovery Corporation (NORCO).
In this concept, utilizing a vacuum distillation technique,
the grantee has produced with relatively antiquated equip-
ment, marketable Number 2 and Number 4, sulfur-free and
metallic-free fuel oil. The flow sheet, mass balance and cost
estimates are shown in Figure 2 and Table III. The fuel oil
products become dark following exposure to light, and
exhibit a floe plus a slight odor which precluded its sale to
those outlets which also required the oil to be esthetically
acceptable.
Extensive investigations to determine the source of the
trouble indicated it to be:
a. Oxygenated hydrocarbons which are generated in
small percentages during fuel burning, and enter the engine
crankcase mainly as blowby past the pistons.
b. Nitrogen oxide in blowby gases which acts as a
catalyst in tar formation.
c. Additives that are compounded into the motor oil
to inhibit the formation of deposits during engine opera-
tion.
These additives appear to break down at temperatures of
about 700°F and become the precursor of tarry deposits
during the distillation process.
Double distillate runs and removal of the polymers and
metallics by head-end treatment processes indicate an
enhancement of color and odor and a marked decrease in
the light induced floe. Additional runs are proposed with
new modern critical equipment, plus modified flow sheets
to demonstrate that used crankcase oils can be economi-
cally converted to not only fuel oils, but also to diesel oil
and as metallic free chemical oil stocks for use in industry.
Note that in the present mode of reprocessing the waste
oils, approximately 25 percent of the original charge is in
the bottoms. A customer of NORCO has purchased the
bottoms, mixed it at a high ratio of about 10-to-l and has,
in turn, sold it on a rotation system to a few customers who
have burning equipment that have not been noticeable
affected following some burning tests. The fuel oil vendor
indicated that because some of his customers' equipment
was detrimentally affected, he now maintains a strict log on
-------
96
OIL SPILL PREVENTION
BAR CONO.
100 PSIG STEAM
BAR.OONQ.
FLASH
FURNACE
STORAGE
TANK I
r
-LL
t
\
•A
VENT
100 PSIG
STEAM
VWC
FRACTKDNATOR
2T HG-MO°F
FLASH
-TGWER
50»F -W>F
CHARGE MOGPH
OH., 1737GPH
H2O.63GPH
OIL-V^TER
SEPERATORS
rf
NAPTHA 27GPH
i
\
1 -
K VY CUT
f
' S04GPH " J
FRACTIONATOR
OVERHEAD
W2GPH
BOTTOMS
COOLER
396 GPH
648GPH
Figure 2
sales to all customers so each will not obtain more than one
or two loads of this mixture in five deliveries.
Of the several methods proposed for handling waste oils,
I firmly believe that, only if a viable waste oil industry can
be created, one which is also compatible with environ-
mental requirements, will the waste oil problem be really
resolved.
CONCLUSIONS:
The fate of large volumes of waste oils cannot be
accounted for. This waste product is potentially a great
source of pollution. Whereas the rerefining industry may
have, in the past, been able to handle the entire volume and
recycle this product for useful and safe consumption, the
combination of changes in the crankcase oil, economics of
handling and processing plus air, water and solid waste
management statutes have caused the capacity of the
industry to suffer markedly. The volume of oils that can
potentially be released to the environment can become
staggering and can become one of the greatest water
pollution and nuisance problems in the nation.
It is important that this potential source of pollution be
recognized and that both management and technology
changes be instituted to recycle this valuable resource.
REFERENCES
1. American Petroleum Institute Final Report of the
Task Force on Used Oil Disposal, May 1970.
2. Association of Petroleum Re-Refiners Letter Report,
February 11,1970.
3. Natonal Oil Recovery Corporation Project No. 15080
DBQ Demonstration of the complete conversion of crank-
case oil into useful products without producing Pollutant
Materials, January 1971.
-------
PREVENTION OF MARINE POLLUTION
THROUGH UNDERSTANDING
Paul M. Hammer
Marine Advisory and Associated Services
ABSTRACT
In order to place new emphasis on marine pollution
prevention in the complex field of tanker operations, the
author developed, and is currently conducting, a Shipboard
Pollution Control Indoctrination and Training Program.
This program, presented on-board during passage, covers all
aspects of ship operations at sea and in port which have
pollution potential. Through the use of movies, slides,
formal and informal discussion sessions the officers and
crew are given a better understanding of the economic, legal
and technical factors of marine pollution; good operating
practices are reviewed; the ship/terminal relationship is
explored; the policies and programs of management are
emphasized; personnel are prepared for more effective
action should an incident occur; and the overall pollution
control posture of the vessel and terminals is evaluated.
Meetings with management are held before and after the
shipboard session as a result of which comprehensive
pollution control programs are instituted or updated based
to a great extent upon the feedback from the ships and
recommendations of the author.
Based upon experiences with independent, oil company
and government contract tanker operators, and government
agencies functioning in the field, 1) details of the program
and its reception are reviewed, 2) observations are pre-
sented relative to conditions and particular problem areas
encountered, 3) suggestions for further concerted efforts in
the direction of pollution prevention are set forth and, 4)
farther desirable actions in the direction of education and
training are outlined.
INTRODUCTION
There seems to be a feeling on the part of many in both
government and industry that marine pollution and its
control constitute new problem areas with histories devoid
of concern, corrective work and progress. These same
people are prone to offer partial, and often impractical,
solutions without recognizing the complexity of the field or
taking the time to determine what has gone before. The
progress they are in a position to bring about is therefore
limited and basic approaches to effective pollution control
are overlooked. My conviction that maximum utilization of
the most effective marine pollution prevention mechanism
available to us—total involvement of a ship's officers and
crew—could bring about immediate and identifiable pollu-
tion reduction resulted in development of the Shipboard
Pollution Control Indoctrination and Training Program.
Ultimately, regardless of laws, regulations and company
policies, it is those involved in daily activities on board who
have substantial control over management expenditures
attributable to pollution. At the same time the reputation
of the ship operator rests in the hands of the Master, his
officers and crew. History bears witness to the fact that this
is one of the "traditions of the sea" and always will be.
Consider the Union Oil Tanker SANTA RITA which put
two fascinating records on the books in 1907—an unusual
cargo delivery for a tanker and one of the first recorded oil
pollution oriented casualties. In February of that year, after
being cleaned by steam injection, she delivered a cargo of
800 pianos to San Francisco. The next month she returned
to San Francisco with a load of fuel oil (not further
identified but quite possibly kerosene) and large quantities
were discharged into the Bay. The oil on the water was
ignited by a spark from a locomotive and the flames
reached the French vessel BEIELDIEU. Consider also the
following 1907 account from J.D. Henry's "Thirty-Five
Years of Oil Transport-the Evaluation of the Tank
Steamer" which gives us one of the first recorded ballast
handling lashups along with a beautiful example of under-
statement.
97
-------
98 PREVENTION THROUGH UNDERSTANDING
"There was a curious accident to one of the Pacific Oil
Traders a few months ago. While the vessel was off the
Coast the pumps were employed to clear some of her tanks
of water ballast, when, by an extraordinary mistake, they
started to discharge large quantities of oil cargo into the
sea."
Hundreds of thousands of words have been written in
laws, regulations, company policies and procedures related
to ship-oriented oil pollution control alone since 1907. Yet
we continue to be faced with the same operational
problems reflected by the above incidents. Definitive goals
have been set toward international total prohibition of
discharge of oil from any vessel anywhere within this
decade. Pressures build daily toward similar goals for all
forms of ship generated refuse. Many of the current design
and fitting-out approaches to overall pollution control are
appropriate for new vessel buildings, and a relatively
"pollution-proof ship-dry cargo, bulk, tanker, or passen-
ger—is not difficult to envision. We will, however, have
thousands of existing vessels with us for decades which
must be provided with alternative means for disposal of oily
ballast, bilge wastes, sanitary wastes, bunker/ballast double
bottom oily mixtures, garbage, trash and the like. Having in
mind limited means and capacities for handling shipboard
wastes on board, even through retrofitting with foreseeable
separators and treatment plants for example, there must be
a realization that all types of existing vessels need in-port
support facilities if sea and navigable waters pollution from
this source is to be brought to the absolute minimum. Up
to this point ships have been regarded as totally self-
sufficient with the waters of the world serving as their
waste dumping grounds—and we now know this cannot
continue. Each person in a position to do so must use every
possible political, regulatory and administrative means
available to promote in-port provision and use of waste
disposal facilities by both domestic and foreign flag vessels.
In the interim and regardless of what future tools are
provided on-board and in-port for pollution control the
men sailing the ships must be brought to, and maintained
at, the maximum level of overall pollution control orienta-
tion. With this orientation shipboard personnel are in a
position to make, and have made, substantial contributions
in the way of ideas (particularly in relation to operations on
their individual vessel) for implementing or upgrading
managements pollution control programs. The result quite
often is considerable reduction of the pollution potential of
the vessel without great expenditures of money. This is one
of the major facets of the shipboard training program and
only results from "going to sea" with the ship.
The decision to develop the Shipboard Pollution Control
Indoctrination and Training Program was made after a
thorough evaluation of current pollution control activities
and attitudes here and abroad specifically as they relate to
ship operation. Discussions were held with ship operators,
marine insurers and government agencies; Coast Guard and
other agency records of numerous pollution incidents were
analyzed; present industry approaches were reviewed; and
the moods of the Congress and the public were considered.
The results of this evaluation dramatically confirmed
that the operators of all types of vessels, and most
particularly tankers, were potentially faced with an un-
precedented number of financial and operational diffi-
culties directly attributable to pollution control attempts
both domestically and internationally. A partial listing of
these would include intense legislation and regulation
toward vessel operational controls with vastly increased
fines for violations, new vessel design requirements, new
in-port cargo handling controls, increased insurance costs
and out-of-line spill cleanup costs all entangled in a web of
interests and jurisdications. It was felt that the resultant
impacts could be lessened and the total interests of ship
operators best protected through prompt institution of
their own progressive and knowledgeable programs toward
effective shipboard pollution control and preparation for
the future. The focal point for any such programs is
obviously the vessel. Only through possession of a compre-
hensive and proper knowledge of the total spectrum of
political, economic, safety and technical aspects of pollu-
tion can shipboard personnel become dedicated to its
prevention and proper handling should an incident occur.
In addition to the obvious economic benefits resulting from
a shipboard educational program it is appropriate to
emphasize that 1) announcement of implementation of a
practical and applied major step toward pollution control
has great public relations value, 2) the courts and regulatory
agencies are favorably disposed toward those who use every
available approach, including out-of-house contract services,
to improve operations, 3) training intensifies profession-
alism and creates a feeling of responsibility, 4) the total
shipboard safety posture is enhanced, 5) all operations
which create a pollution potential are brought into perspec-
tive, 6) where pollution control instructions are in effect
they are reinforced through integration with the on-board
training program, 7) a solid foundation is established upon
which management can plan and build an in-house pollu-
tion control program if none now exists and, 8) the growing
concerns of organized labor over environmental matters are
recognized.
Three specific phases comprise the program over an
approximate period of 7-8 days. First is a one-day
preboarding session with management during which the
following matters are considered relative to the on-board
phase:
—Review of the details and philosophies of the ship-
board presentations,
-Tentative scheduling to include all of the officers and
as many crew members as possible having in mind
union contract terms and the voyage work schedule, all
to be finalized with the Master after boarding,
—Discussion of existing company policies and instruc-
tions toward pollution control,
-------
PREVENTION THROUGH UNDERSTANDING 99
-Discussion of, and suggestions on, management plans
for the future relative to pollution control programs,
-Discussion of the Final Report coverage,
-Evaluation of the previous reports and recommenda-
tions, and their pertinency to the current vessel, in
those cases where other vessels in the fleet have been
involved.
The second phase consists of spending the equivalent of
one leg of a coastwise or nearby foreign voyage aboard,
including observation of the loading and discharging opera-
tions. For the purposes of the program either the loaded or
ballast leg is appropriate. On one hand, the loaded voyage is
the most relaxed; on the other hand observation of tank
cleaning and related operations can be of value providing
program participation by the officers and crew is not
severely handicapped. In any case the in-port stay and the
first day at sea are devoted to observation, becoming
known, and laying the foundation for the subsequent
program. It is during this period that success of the formal
and informal sessions can be assured by overcoming the
normally suspicious nature of seamen. When they find that
the "stranger" holds a current USCG Mate's License, knows
tankers and their operation, speaks their language, has no
interest in evaluating individual performance, and knows his
subject, discussion and progress across-the-board com-
mences.
Six to eight hours (over a period of 2-3 days) are spent
in formal sessions with all deck and engine officers.
Low-key lectures, movies, slides and question/answer
periods are all utilized to upgrade understanding of the
pollution control problem and delineate the part each
officer has to play toward its solution in his own best
interests and those of the company. The major headings of
subject matter covered during these sessions are set forth in
ANNEX A. However the extensive material discussed under
each major item is continually revised to reflect current
developments, to incorporate individual management phi-
losophies and pollution control instructions, and to accom-
modate particular areas of interest shown by vessel person-
nel. It should be noted that approximately the first third of
the program is devoted to developing the background
understanding necessary for vessel personnel to realize the
importance to both themselves and management of the
practical aspects presented in the latter two-thirds. While all
aspects of oil pollution receive major treatment other
pollution sources (hazardous materials, sanitary wastes,
trash and garbage, galley wastes, and to some extent air
pollution) are covered in detail
The approach during the two hours spent with the crew
(one or two evenings after supper) is somewhat different.
Here the emphasis is on generating their concern, reviewing
their responsibilities on deck and in the engine room, and
emphasizing the necessity for total understanding and
proficiency in their jobs. The interest in the program which
is represented by the average 80% voluntary participation
by off-watch crew members from the three operating
departments is quite encouraging.
Equally important is the time, averaging 15 hours, spent
in informal discussions with the officers and crew. It is
during these sessions that much of the feedback so valuable
for effective implementation of management's policies and
procedures is gained, as are numerous practical suggestions
relative to the vessel and its operation. These discussion
periods are also used to obtain officer evaluation of the
feasibility of new concepts and procedures being considered
for fleet-wide application. By design much of this discus-
sion is with the Master, Chief Mate and Chief Engineer-
those who set and implement policy on board.
The remainder of the time on board is spent in observing
all aspects of the operation of the vessel. These observa-
tions, coupled with those made in port, result in a good
picture of the overall pollution control posture of the vessel
and aid in highlighting specific design or procedure prob-
lems which may require attention by management.
The third phase consists of development, submission,
and review of a comprehensive report covering the time on
board for consideration by management. Included is an
evaluation of the effectiveness of the training program,
evaluation of current operating practices on board and in the
terminals visited, recommendations pertinent to such prac-
tices, suggestions related to future pollution control pro-
gram needs, and other matters which may be agreed to
during the preboarding session. Part of this report is an
eighty-item checklist which evaluates the pollution poten-
tial design and operational characteristics of the terminals,
the terminal/ship interrelationship, and the ship itself. The
end results of the evaluations and recommendations of
these reports have been upgrading of existing pollution
control procedures and development of extensive new
programs for fleet-wide application such as a total over-
board discharge line valve sealing concept. The Shipboard
Pollution Control Indoctrination and Training Program
objectives of 1) bringing about, through training and
education on board, an immediate reduction of the
potential for a vessel causing a pollution incident, 2) giving
management a knowledgeable understanding of the effec-
tiveness of their current approaches, and 3) aiding in
development of effective new approaches toward putting
the company and its ships in the best possible situation
have been proven out to both management and the
shipboard personnel.
Observations:
The Shipboard Pollution Control Indoctrination and
Training Program has been conducted on a total of ten
vessels operated by five tanker companies (both indepen-
dent and integrated oil company operators) calling at 18
petroleum terminals. Based on that involvement, the many
hours of related discussion with shipboard and management
-------
100 OIL SPILL PREVENTION
personnel, and the current situation in the maritime
pollution control field the following observations and
conclusions are offered for deliberate consideration by
those who have legitimate interest in the reduction of sea
and navigable waters pollution. Certainly exceptions to
each exist but the intent is to reflect general areas which
require broad-based consideration.
-Officer and crew personnel are quite concerned over all
aspects of marine pollution, particularly as their
profession and jobs are affected. For this reason they
welcome every new step taken by management toward
giving them the knowledge, tools and support neces-
sary to do the best possible job under the pressures
they are now facing in U.S. and foreign ports.
-Several trends that seem to be under way reflect the
possibility that the tanker industry may face a shortage
of experienced and competent tanker officers in a few
years. Due to the increasing involvement of manage-
ment, government and unions with the ship and its
operation (with the resultant pressures on the officers)
the highly experienced and professional tankermen are
abandoning ship as soon as their finances and retire-
ment programs will permit. Concurrently, the general
lack of programs toward assurance of a secure career
for junior officers does nothing to promote their
interest in becoming proficient and dedicated tanker-
men. The situation is further complicated by the
number of relatively senior dry cargo ship officers
taking tanker jobs without an inclination toward
gaining proficiency. The increasing complexity of
tanker designs, cargos, and operating conditions dic-
tates that every possible step be taken toward promo-
tion of the education, training, proficiency and reten-
tion of tanker personnel.
—There is a great lack of written and audio-visual
materials appropriate and specifically designed for
marine pollution control training and education. Such
materials, properly and knowledgeably developed,
could make a substantial contribution to pollution
reduction. Their use by maritime training schools
(state, federal and union), management, and on board
would result in a considerable raising of understanding
and competency levels. Related to this is the difficult
situation created by the fact that experience in the
complex concept of safe and efficient bulk liquid
transfer and overall cargo handling operations can only
be gained on an operational vessel since no shoreside
training facilities exist. Development of training/
educational materials and facilities with marine pollu-
tion control orientation by the ship/terminal/
petroleum industries working together with govern-
ment support is worthy of careful consideration.
—A major area of concern by ships' personnel, related to
pollution control as well as overall operational safety,
is the great variance in design and operational charac-
teristics of terminals, the apparent lack of concerted
effort to bring terminals to a level of control parallel to
that placed on the vessel and its personnel, and their
interrelationship and joint responsibilities with ter-
minal personnel. Quite often the ultimate result is
conflict not in the best interests of the ship or
terminal. Resolution of this situation should be a high
priority matter for those with a legitimate part to play.
—By their nature, and as a result of past incidents, the
so-called persistent oils have received the bulk of oil
pollution control attention. However the impact of
current legislative and regulatory controls on navigable
waters emphasizes the fact that the operation of clean
oil vessels, and the problems encountered by their
personnel, are equally as important. Further, an inport
spill situation involving clean products or hazardous
materials, regardless of the source, can present diffi-
culties in excess of these encountered with many
persistent oils. The differentiation between oil pollu-
tants, particularly in territorial waters, does nothing to
promote overall pollution reduction.
-Traditionally tankers and their personnel have been
singled out for special scorn in connection with oil
pollution by those who do not grasp the total marine
pollution situation. Perhaps there is some foundation
for this but if total dedication to pollution control is
desired from tankermen immediate attention must be
paid to all sources of oil pollution in the ports and on
the seas of the world they share with others. Tankers,
dry cargo and passenger vessels of U.S. and foreign
registry; naval vessels; tugs and barges; shoreside
facilities and other sources all contribute substantially
to the total marine pollution problem. Unfortunately,
tanker operators and personnel suffer under another
"tradition of the sea"—when oil appears on the water
it is automatically assumed by enforcement personnel
that a tanker was the source and action is taken under
that assumption. It is also traditional that those
involved with the true source are quite willing to
perpetuate the "it must have been a tanker" assump-
tion. The defensive position this situation forces them
into is quite frustrating to tanker personnel and they
anxiously await evidence that sources of oil other than
from tankers are being recognized and corrected.
—The current trend toward uncoordinated and con-
flicting state, municipal and other local regulation of
vessel operation in connection with all phases of
pollution control is producing mass confusion and
consternation on board the ships. Under the Constitu-
tion the Federal Government preempts the control of
interstate and foreign commerce, and in fact specif-
ically did so by Presidential Order in connection with
bringing tank vessel safety under control of the original
Bureau of Marine Inspection and Navigation in order
to resolve the intolerable situation created by con-
flicting local regulation. The same situation exists
today in relation to pollution control, and it is also
becoming intolerable. The inevitable result will be
costs to the ultimate consumer far beyond those
necessary for effective pollution control. Development
-------
PREVENTION THROUGH UNDERSTANDING 101
and promulgation of a coordinated, comprehensive,
and effective set of pollution control requirements
covering all aspects of marine operations involving
interstate and international commerce appears manda-
tory, and should be the result of the involved
industries and the Federal establishment working
cooperatively toward a common goal-Federal pre-
emption of the field! If this is not accomplished utter
chaos lies immediately ahead and attainable pollution
control goals will never be achieved.
CONCLUSIONS:
As has been proven on board ship the most effective
approach to immediate reduction of marine pollution is
upgrading of the knowledge and operating practices of
personnel directly involved in activities having pollution
potential. Once this has been done institution of a knowl-
edgeable program to keep them constantly aware and
informed will enable them to effectively implement future
procedures, particularly if the operating personnel have had
the opportunity to provide practical inputs to management.
The alternatives, pollution control by management edict
and duplicatory government regulation, cannot succeed.
SHIPBOARD POLLUTION CONTROL TRAINING PROGRAM
Subject Coverage Outline
Orientation to the Objectives of the Program
The Program Content and Approaches to Presentation
History of Pollution Control Activities Within the Federal Government
History of Pollution Control Activities Within the Shipping Industry
History of Pollution Control Activities at the International Level
Review of Pertinent Domestic Laws and Regulations
Review of Pertinent International Conventions
The Process of Development of Domestic Requirements
The Process of Development of International Requirements
Domestic Agencies, their Jurisdictions and Activities
International Agencies, their Jurisdictions and Activities
Legal and Financial Liabilities of the Officers and Crew
Responsibilities of Vessel Personnel to Management
Responsibilities of the Terminal Operator
Effects of Various Pollutants on Marine Environments
The Complex Relationships Between Pollution and Safety
Refinery Operations Related to Crude Processing
Physical and Chemical Aspects of Oil and Other Pollutants On and In Water
The Potential for Pollution from Routine Ship Operation
Potential Pollution Problems During Cargo Transfer
Potential Pollution Problems During Bunkering Operations
Operating Practices for Pollution Prevention
Maintenance as a Pollution Control Practice
Tank Cleaning Procedures from the Viewpoint of Pollution Control
Ballast Handling from the Viewpoint of Pollution Control
Shoreside Ballast/Slop Handling Facilities
Bilge Waste Handling Procedures
The Load-on-Top Approach to Crude Carriage
The Tanker Owners Voluntary Agreement on Liability for Oil Pollution
(TOVALOP) and Vessel Personnel Responsibilities Thereunder
Priority of Actions in Minor Spill Situations
Priority of Actions in Gross Spill Situations
Evaluation of the Seriousness of an Incident
Operation of the Federal Oil Spill Contingency Plan
On-Board Spill Handling Techniques
Over-The-Side Spill Handling Techniques
The Lessons of History on Repeated Spill Causes
Current Status of Technological Development Projects
Continuing Sources of Pollution Control Information
The Future Plans of Management Relative to Pollution Control
Reporting Requirements
-------
DEVELOPMENT OF TANK VESSEL OVERFILL
ALARM INSTRUMENTS
Donald J. Leonard
Shell Development Co.
Emeryville, California
ABSTRACT
At the API-FWPCA joint conference on prevention and
control of oil spills held in New York in 1969, it was
reported that two-thirds of the oil spill incidents each year
occurred in port and harbor areas and were generated
during routine petroleum transfer operations. Based on our
investigations, the spills are generally the result of personnel
errors and only rarely due to equipment failure.
This paper describes the concept, development and
initial trials of a number of devices made for Shell and used
to prevent spills due to tank overfilling during tank vessel
boding. The instruments are inserted into the tanks
though tank-top ullage holes. They sound an alarm when
product reaches a level where a spill is imminent, alerting
crewmen and allowing them to take corrective action.
Complete instrument specifications are given as they
were presented to companies working with Shell on the
device development.
The evaluation, shipping company and U.S. Coast Guard
involvement and support, field testing of prototypes and
factors affecting Shell's device choice are described.
Apparent favorable initial device reception by the users,
ihip crewmen and dock personnel (bearing largely on
instrument effectiveness) is described.
A second phase effort is described which will accumulate
these alarms and provide an automatic link to shore
facilities to shut down pumps or close valves upon receipt
of an overfill alarm,
INTRODUCTION
In a continuing effort to prevent oil spills in Shell marine
loading operations, a project was begun to determine if
further means could be devised to prevent small spills of
this nature.
CONCEPT
Our investigations showed that error on the part of
personnel was the major source of spills with most of the
spill incidents resulting from tank overfilling. For many
reasons, personnel did not give enough attention to the
details of tank loading. Adding to the problem are the
higher loading rates now encountered as compared to those
formerly used. Rates can reach 10,000, 20,000 bbl/hr and
sometimes, compartments can be filled in less than one
hour.
Some of the problems encountered by shipboard people
can be illustrated by the following comments from reported
spills:
". we filled that tank and was filling this one but the
valve between them must have leaked so here the stuff
comes up out of the first tank. ... "
" he thought it was only going into Number 1
Center but it was going into 1 Port too which is smaller and
he didn't check it "
" .... we saw the tank start to overflow but the
wharfman couldn't stop his pumps in time "
Candid conversations with any tank vessel crewmen will
reveal similar stories and comments shared by all oil and
shipping companies.
The major problem for dock personnel is to be im-
mediately available when action is required to stop product
loading. Lack of rapid communication between ship and
shore at the time of emergency is a common problem. At
times the ship is not notified when flow rates change. In
addition, crewmen are reluctant to close shipboard valves
against the on-shore pumping pressure, feeling that a
broken hose could cause a worse situation than a compart-
ment overflow.
What can be done to assist crewmen and wharfmen to
better control the loading operation?
103
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104 OIL SPILL PREVENTION ...
After much observation of loading operations on many
tankers and barges of various shipping lines and oil
companies and many long discussions with ships' crews,
officers and dock people it became apparent that one
immediate solution for this type of spill would be some sort
of equipment which could be used in each tank being filled.
The apparatus would sound an alarm in order to alert
crewmen that a spill was imminent (in the event that a
filling tank had been neglected or missed and product level
became abnormally high) and that some action should be
taken to prevent it.
IMMEDIATE SOLUTION AND DEVELOPMENT
In other words, what was required was a portable high
level alarm. Simple. As can be seen from the specifications
as they finally evolved, the requirements were anything but
simple (see appendix for complete specifications essentially
the same as were sent out for quotation). There are many
subtle problem areas. The biggest problem and indeed still a
potential bottleneck is in the area of tank entry.
Shell wanted a safe, lightweight, self-contained, reliable,
rugged instrument that initially would be stored on docks
to be carried aboard tank vessels. It would have the widest
application, that is, it would be usable on all varieties of
tankers and barges that visit Shell terminals as well as with
all of the normal refinery products.
In March, 1970, in conjunction with the visits to
tank vessels and barges, a search was made of trade
literature to try to find devices already existing for this
application. None was found.
Several companies, selected by various means (referrals,
trade journal ads, exhibits at trade shows) were contacted
to determine their interest in developing the required
instrument. Concurrently, our own development of a device
was attempted and several approaches rejected. A foreign
company was discovered marketing a unit that appeared
promising for alarming on overfilling tanks. The instrument
was purchased and examined and found unsuitable for a
number of reasons.
It was soon felt that the satisfactory development of a
suitable instrument would best be done by taking advantage
of the talents of more companies. Since no suitable
instrument existed and progress seemed slow, it was
decided that a description of the instrument requirements
would be sent to a number of companies in order to take
advantage of many diverse technologies and enable a
selection to be made from many proposed solutions.
In the evolution of the specifications, Keystone Shipping
Co., a barge line, the U.S. Coast Guard MMT office and
various Shell departments were consulted and shown drafts
of the specifications with requests for comments and
direction before the inquiries were released.
The description that was developed (included here in its
entirety as an appendix) was sent in August, 1970, with
requests for quotation reaching 170 companies selected
from industrial instruments and control, cryogenics, fluidic,
geophysical and oceanographic concerns.
A total of 111 companies responded. Of this 111, 34
submitted preliminary proposals of which 16 appeared
reasonable.
In the end, seven companies supplied prototypes for
evaluation. As hoped, they offered widely varying solutions
to the many subtle problems. As some devices are still
under development by a number of companies, only very
general descriptions will be given here in order to preserve
proprietary information.
Two are powered by wind-up spring motors. This is
really the ideal energy source with respect to replenishment
because the recharging mechanism is walking around the
ship in the form of a crewman. The major drawback for
these units turned out to be the sound level available. It was
judged to be insufficient for large tankers but perfectly
adequate for barges or smaller vessels.
Three are gas powered. CO2 was finally selected as the
best gas (superior to freon for this application) because of
its availability (even small towns have a fire extinguisher
recharging concern), it retains usable pressure over wider
temperature ranges than most freons, and its "expand-
ability" (here defined as the volume of gas available at
ambient conditions from a given volume of the liquefied
gas) was satisfactory as was the sound production of all
CO devices. Also, all handling and storage of C02
cylinders and instruments can take place in any hazardous
area.
Two are battery powered. Both are intrinsically safe but
a safe area must be provided for their recharging. These
turned out to be the units lightest in weight but provided
lower sound output than the gas operated devices.
All but one of the prototypes made use of the tank
entry technique of passing a small tubing or cable under
existing fire screens.
TANK ENTRY
How to enter a tank and do it safely?
The most direct way, keeping the concept of a light-
weight, portable instrument is to insert a probe of some
sort into the tank through an existing opening - namely the
ullage hole. (A sketch of a typical tanker tank top showing
the ullage hole is included in the appendix for reference.)
This must be done so as to disturb the integrity of the fire
screen as little as possible. Many fire screens were seen to fit
quite loosely in their ullage holes so that a tubing or cable
no more than 1/8" in diameter could pass under the screen
and into the compartment without interfering with the
operation of the fire screen. The San Francisco USCG
office agreed, at least for purposes of the proposed field
tests of prototype devices under adequate supervision.
Present USCG regulations concerning ullage fire screen
operation are contained in 46 CFR 38.30-10 in "Rules and
Regulations for Tank Vessels", Subchapter D-CG 123,
which is given here.
"38.30-10 Cargo tank hatches, ullage holes, and Butter-
worth plates-TB/ALL. No cargo tank hatches, ullage holes, or
Butterworth plates shall be opened or shall remain open
without flame screens except under supervision of the
-------
OVERFILL ALARM INSTRUMENTS 1Q5
senior members of the crew on duty, unless the tank
opened is gas free."
An alternate means of tank entry for a portable
instrument is the "universal fire screen" approach. In this
technique, the existing fire screen is completely removed
and another is put in its place. The new screen will be
equipped to pass a probe into the tank while maintaining
screen integrity. The approach has generated handling
problems, a potentially cumbersome device and one that
may interfere with normal tank gauging operations.
Another solution is, of course, to modify the ship itself,
installing permanent fittings, remote tank level measure-
ment devices or even entire instruments somewhere in the
compartments. It was felt that to modify all vessels would
be a major, costly effort involving extensive development
and long lead times. The portable alarm development was
undertaken to provide a universal instrument which could
be used immediately and which would reduce the number
of spills at least until a major effort could be defined and
gotten under way.
FIELD TESTING
Field testing of prototypes consisted solely of exposing
instruments to handling by the people who would be using
them - namely ships' crewmen and dock personnel.
After receipt of the prototype instruments, an energy
analysis was made of each electrically powered unit to
ensure that they were intrinsically safe. Once this was
established and the devices were felt structurally suitable
(Le., able to withstand the abuse to which they would be
subjected) they all were taken to the San Francisco USCG
MMT office for their inspection and approval. The officers
verified the safety of the instruments and provided a letter
so stating, authorizing Shell to use a particular device for a
certain period of time (months) as an experiment. The
devices were then demonstrated to Port Security-Dock
Patrol personnel - those who would encounter the instru-
ments during the normal course of their duties.
Then the instruments were taken aboard vessels, ex-
plained and demonstrated to the ships' officers and
crewmen. The sensors were immersed in product and the
devices produced sound to everyone's satisfaction. Crew-
men handled the units and offered their very valuable
comments regarding device handling characteristics and
improvements. These suggestions were relayed to the
instrument manufacturers in order to develop more usable
devices.
Keystone Shipping Co. kindly offered much encourage-
ment plus the use of their vessels and facilities for the
development effort. The cooperation of their management,
ships' officers and crew play a major part in the progress of
the project.
RECEPTION
In general, the reception given the prototype devices by
shipboard people has been extremely favorable and no
acceptance problem is anticipated. The view seems to be
that the instruments present a means to assist the crewman
in his job as well as reduce the potential for costly fines and
delays. In fact, the concept of the instrument has generated
enthusiasm wherever it has been aired.
There is an initial fear that crewmen will learn to depend
upon the alarms to make their jobs easier, relaxing until
they hear an alarm, finding the alarming tank and servicing
it. After demonstrating the sound volume of the instru-
ments, it is generally agreed that the fact that the alarm
indicates a possible error would preclude its use as a routine
signal.
SELECTION
Two instruments were selected for further investigation
by Shell. One is the "Metralert" from Metritape Inc. of
Concord, Massachusetts (battery powered) and the other is
the "Polluta-Hooter" by Cryogenic Research Co. Inc.,
Boulder, Colorado (CO2 powered). At this time, both meet
most of the requirements (weight, ease of handling, sound
level, etc.) better than others. Some manufacturers are still
continuing development so others may turn out to be
superior in the future.
For the present, these two are acceptable and are
farthest along in their development. The reason two were
selected is since one is battery powered and the other is
CO2 powered, we can offer acceptable alternatives to users
where construction of special facilities, ease of handling, or
as yet unknown local factors become important. Both
companies are aware of the potential for further modifica-
tion of their devices as a result of some as yet undefined
requirements. The sensors for both enter the tank by
passing a small tubing for the "Polluta-Hooter" and a small
cable for the "Metralert" under the ship's fire screens.
At this writing, Shell is planning to purchase quantities
of each instrument for more intensive trials. The trials will
demonstrate instrument use and recharging patterns that
will evolve and may uncover possible jurisdictional or
manning problems. As has been done since the inception of
the project, we will continue to work closely with the Coast
Guard (or other agencies that may become involved),
shipping companies and barge lines in order to develop
mutually acceptable instruments. Although the two devices
are usable at present, there are areas that will be revealed
only by use that are worthy of further improvement in
order to produce a sturdier, lighter, more easily handled,
etc., instrument. This could be considered the final proto-
type stage for the instruments. As presently visualized, the
trials will involve realistic handling of devices by wharf
personnel and crewmen, with the wharf persons accounting
for the instruments, maintaining them and providing
introduction and initial simple use training to incoming
tanker crews and bargemen.
An observer will be on hand to record comments,
reactions and problems and to provide training, backup
support and encouragement to the wharfmen. He will also
define and relay directions for improvements to the device
manufacturer.
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106 OIL SPILL PREVENTION ...
When this phase is complete, there will be available two
high quality instruments that Shell or anyone else can
purchase with confidence.
CONTINUATION
It is proposed that the next phase be an investigation of
ways to accumulate the alarm signals from each instru-
ement in use on the tank vessel to provide a signal to shore
facilities in order to automatically shut down the loading
operation upon receipt of an alarm.
Present philosophy is that after an overfill alarm begins
to sound and does so continuously for, say, 30 seconds, a
crewman must service the alarming tank by shutting off the
instrument (which means that he must be at the tank and
so available in most cases to divert product flow somewhere
else), or the entire loading operation is shut down auto-
matically. Insertion into each instrument of a small, low
power telemetry transmitter with a receiver either on the
dock or hanging on the ship's rail is one way to accomplish
this.
One common aspect of the evolution of these instru-
ments is the enthusiasm and support offered by everyone
involved. The feeling most prevalent seemed to be one of
relief to the extent that something specific was being done
to help prevent spills. At the very least, the project has
generated activity and interest in a problem area and it is
believed that any attention focused on cures for this type
of problem can only result in a reduction of accidental
spills encountered in marine operations.
MATERIAL IS
ALUMIHUM, IROU
OK sreet.
HATCH COVER
ULLAGE HOLE
FIK£ SCREEN
RIHG. - FIKE
SCREEN KKTS
ON THIS RIUG
TRUHK
(TAUK)
DECK
Figure 1: Typical Tank Top Cross Section Type 'T2" Tankers
Showing Ullage Hole and Fire Screen Location.
APPENDIX
Request for Quotation on Overflow Alarm Device
GENERAL
This inquiry describes requirements for portable instru-
ments to be used on board tank vessels (tankers, barges) to
give an indication of imminent tank overfilling (high level)
in order to prevent spillage of products into waterways. The
instruments will be used on the decks of the vessels and will
sound an audible alarm (they may provide a visual signal as
well, such as a flag or light) which will alert ships crew and
dock personnel to take appropriate action to avoid a spill.
Readout or measurement of absolute tank level is NOT
required.
There should be a single instrument type to cover all
applications.
The instruments will be stored on docks and possibly
also on board tank vessels. They will be used at any time,
day or night. They must be self-contained, that is, requiring
no external power supply connection, they must be
lightweight, easy to carry about and handle, and ultra-
reliable.
The audio signal should be loud and distinctive in order
to be heard in conditions of high ambient noise (storms)
and over distances of 500 feet.
The devices should be able to operate in ambient
temperature conditions of -20°F to 140°F and the
environmental conditions associated with a corrosive
marine atmosphere. They should be able to withstand
anticipated rough handling, such as repeated dropping from
a 4-foot height.
The instruments may be powered electrically, pneumati-
cally, mechanically, or combinations of any energy source.
The energy source must be easily replaceable and/or
rechargeable with a minimum of special equipment or
handling required. It must be easy to test the status (charge,
pressure, etc.) of the energy source. Some means to test the
operation of the entire instrument is required. This should
test as much of the instruments' operation as possible.
The device should operate for at least 12 hours without
depletion of any of the energy sources and at the end of
that time be able to sound its alarm for at least one minute.
SAFETY
An absolute requirement is the safety of the device. The
location of use is considered Class I, Division I, Group D
(Pentane Group). The instruments may or may not be
stored in a safe area. The equipment, if electrical or
electronic, must be shown to be intrinsically safe by the
manufacturer by presentation to Shell Development of a
detailed energy balance statement with schematic and parts
list, etc., demonstrating conformance to ISA Recom-
mended Practice 12.2 for intrinsically safe equipment.
Explosion proof equipment is also acceptable and must
conform to National Electrical Code Chapter 5 for Class I,
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OVERFILL ALARM INSTRUMENTS 107
Division I, Group D locations, although it is felt that
explosion proof equipment may be prohibitively heavy.
Products to be loaded into tank vessels are any standard
petroleum refinery product from gasoline through cat
cracker feed stock, bunker fuel, crude oil, to asphalt at over
300° F. Densities will be from approximately 0.75 to 1.
Service is often dirty so the instrument should be easy to
dean and maintain.
SENSOR
The sensor, or that portion of the instrument which will
be inside the tank must be capable of withstanding
operational temperatures to 350° F. It must function
without becoming clogged as could happen with repeated
immersions in asphalt. Size should be small so as not to
interfere with normal tank gauging operations. Pressures
inside the tank during normal filling operations may be 1 to
2 inches of water or less. The device should be able to sense
product level 10 feet below the lip of the ullage hole (see
sketch).
Limited use of the instrument is anticipated for loading
of bunker fuel into cargo ships. This would require a sensor
capable of sensing fuel levels to 50 feet below the edge" of a
small (6 inch diameter) ullage pipe. Temporary replacement
of the normally-used sensor portion of the instrument with
a longer one for this purpose is acceptable.
Since tank filling rates will vary, some degree of
adjustability is desired. This could be accomplished by
simply coiling a tube or cable (or providing a slippable
hangar) in order to vertically position a sensing element.
Where possible, distances in feet from the end of the sensor
should be marked on the tube or cable. This is especially
important for the bunkering operation.
For protection against dangerous static discharges, there
must be no unearthed conductors placed inside the tank.
Proposed instruments with metallic sensors must provide a
positive means for grounding the instrument, possibly by
way of a substantial cable and large clip for external
connection to ships' structure. There should be no sharp
points present on the conductive sensor.
[Later it was decided to insist that no exposed metallic
objects be placed inside the tank.]
Insulators and insulating material placed inside the tank
present no problem.
TANK ENTRY FOR LEVEL SENSING DEVICES
Although the audible sounding mechanism and power
supply may rest outside the tank, some portion of the
device, the sensor, will probably be placed temporarily
inside the tank. Two methods of tank entry have been
approved for trial purposes by the local U.S. Coast Guard.
Both methods require operation around a "fire screen" or
"ullage screen." The enclosed sketch shows some details of
the access area around a typical tanker tank top.
Fire Screen
A fire screen is a removable structure, 6,8, 10 inches in
diameter (these dimensions are valid for most American
tank vessels, although there are many different sizes and
shapes, i.e., unusual dimensions on foreign vessels, and on
some barges seen on the Mississippi River, the removable
fire screen is square and the ullage hole is oval shaped).
There is a screen associated with each on-board tank to
provide a place for the crew to check tank ullage. They also
allow safe venting of vapors as the tank is being filled.
The screens usually rest horizontally on a ring mounted
inside the ullage hole (a section of pipe) and approximately
3/4 to 2-1/2 inches down from the top of the ullage hole.
They are made of brass, aluminum, or stainless steel and
weigh between one-half pound and six pounds. The screen
portion is at least 30 X 30 mesh. The screen must remain in
place at all times while loading and unloading cargo except
when removed by a crew member for tank gauging.
One approved method of tank entry involves removing
the existing fire screen and replacing it with a "universal"
screen which would cover all sizes of ullage holes. This
screen would fit OVER the ullage hole and be at least 10
inches in diameter to cover all smaller size ullage holes.
Special penetration of the "universal" screen by the sensor
could be accomplished to maintain the integrity of the fire
screen mesh.
The variable structure (typical of that shown in the
sketch) around the ullage hole makes this approach
difficult. It can be seen that the hinges for the ullage cover
would interfere with a larger size screen being placed over
the hole. A staggered or stepped screen may work, however.
The Mississippi River barges, with their square fire screen
and oval ullage hole, further add to the difficulties of the
"universal" screen approach. Other barges are fitted with an
ullage hole which is a 41-inch high, 6-inch diameter pipe
mounted on the deck, with no surrounding structure at all.
The other approved method for tank entry is to retain
the original screen but slip a tube or cable under the edge of
the screen slightly cocking it. The screens do not fit tightly
in the holes. The tube or cable should be 1/8 inch diameter
and there should probably be some means to support the
tube from the ullage hole lip.
It may be possible to devise some means to couple a high
tank level signal through the fire screen (magnetic, sonic,
electronic) which would eliminate the problems of a special
screen or tank access around the screen.
During tank filling operations on those vessels having no
automatic tapes or other tank gauging equipment, the
crewman checks tank ullage by lifting the fire screen and
looking into the tank sometimes lowering a float on the end
of a metal tape to gauge depth of product in the tank. The
fire screen is replaced in the ullage hole after gauging is
complete.
It is conceivable that the fire screen could be dropped or
jammed against the tube or cable entering the tank from
the alarm device, crushing, shorting or severing it. Some
form of protection should be employed to prevent this or
at least to detect the presence of faults of this nature.
-------
108 OIL SPILL PREVENTION...
There should be nothing placed inside the tank which
will be used as a sensor that will float freely under normal
conditions because there are ship structural members and
ladders in the ullage hole area, and the device when floating
could become entangled and lost.
Operation
At present, the general conception of operation of the
alarm instrument is that dock personnel or ships crewmen
will carry on board as many instruments as there will be
tanks being filled (say 10, although many tankers have 30
or more tanks which could conceivably be filling at one
time). The instruments will be positioned near each ullage
hole on the hatch cover or possibly hung on the lip of the
ullage hole (attractive for barges with their 41-inch ullage
pipe). The sensing element will be passed into the tank, and
the fire screen will be replaced. Then the instrument will be
turned on, tested for operation, and left alone. Crewmen
will supposedly be checking tank ullage in the normal
fashion which will not disturb the alarm. The device should
be removed before the final supervised topping off of the
tank takes place. It will probably be put aside to later be
used in another tank or to be picked up and taken ashore
for storage. However, the sensor will many times remain in
the tank until rising product level activates or covers it.
Only then will it be removed.
Tests
On board tests of instrument prototypes or finished
instruments will determine actual use patterns and demon-
strate instrument sturdiness. Prototypes must meet all
applicable final safety requirements and should be mechani-
cally able to withstand the abuse to which they will be
subjected.
At least one prototype instrument is required although
more than one will offer a better test.
Preliminary designs may be submitted to Shell Develop-
ment for discussion and clarification and should be received
not later than 30 days after receipt of this request. Upon
mutual approval of a preliminary design, a final design,
specifications, and prototype instrument should be received
within 60 days. This includes any energy balance state-
ments for proof of device safety.
After Shell Development has been shown that the device
meets all requirements, we will submit all documentation
and equipment to the local U.S. Coast Guard office for
their approval to conduct on-board trials at a Shell dock.
We will witness the tests and report the results to the
manufacturer. The U.S. Coast Guard will be kept continu-
ally aware of progress and problems and indeed may also
wish to observe.
Representatives of the appropriate shipping and barge
companies have agreed to the use of their vessels for these
tests and are quite interested in the project.
Shell Development will evaluate all instruments sub-
mitted and recommend purchase of the instrument which
best meets the requirements as outlined in this note.
It is expected thai other oil and transport companies will
be interested in equipment of this nature for similar
applications which will considerably broaden the market
beyond Shell's requirement.
This note is meant merely to provide very general
constraints in the interest of saving time and should in no
way' limit the ingenuity or special skills of any manufac-
turer.
Applicable USCG publications are:
"Rules and Regulations for Tank Vessels", subchapter
D, CGI 23.
"Electrical Engineering Regulations", subchapter J. CG
259 (see Section 111.60 and Section 111.65)
To request the Coast Guard publications, contact
Officer-in-Charge, Marine Inspection, U.S. Coast Guard,
local office.
The ISA publication on intrinsically safe equipment is
RP 12.2, "Intrinsically Safe and Non-Incendive Electrical
Instruments." ISA, 400 Stanwix Street, Pittsburgh, Penn-
sylvania 15222.
-------
USE OF A GRAVITY TYPE OIL SEPARATOR
FOR TANKER OPERATIONS
W. H. Lockwood
Cities Service Tankers Corporation
R. O. Norris
Research Division, Cities Service Oil Company
ABSTRACT
The need to control the oil content in ballast and tank
cleaning discharges to meet increasingly stringent seawater
pollution standards has led to the development of a gravity
type separator capable of handling up to 300 tons/hour of
city ballast water. When properly handled these separators
enable the tanker operator to clean tanks and process oily
ballast with an oil content of up to 100% without fear of
contamination of the seas. This continuous and automatic
operation is unaffected by normal movements. The re-
covered oil is available for burning as fuel aboard ship,
"load-on-top "or disposal ashore.
Separators of this type have been in use on three
70,000 DWT ships, for periods of one to three years. On
typical voyages a ship of this size can recover enough slop
oU to provide one day or more of bunkers if the ship is
equipped to bum the recovered oil. The ship's crew is
trained to carry out analysis of the oil to determine if the
oil can be burned onboard immediately following separa-
tion or must be treated to drop out salt and/or water prior
to burning. Several typical ballast voyages using the separa-
tor will be discussed. The overboard discharge of water
from the separator is analyzed to assure compliance with
current pollution regulations and a means to shunt the over-
board discharge into a holding tank is employed if the oil
content is too high. Limitations and possible improvements
of this type of separator will also be presented.
In May, 1967 the 1962 Amendments to the 1954
International Convention for the Prevention of Pollution of
the Sea by Oil came into force. One of these amendments
prohibits all ships of 20,000 DWT and over, for which the
building contract is entered into on or after May, 1967,
from discharging oil or an oily mixture, defined as water
with an oil content equal to or greater than 100 parts in
one million parts of the mixture, in designated areas of the
world.
The IMCO Subcommittee on Marine Pollution met in
December, 1968 to consider, among other things, possible
changes to the International Convention for the Prevention
of the Pollution of the Sea by Oil, 1954 as amended.
An amendment to Article III of 1954 is to substitute
the following: Subject to the provisions of Articles IV and
V; The discharge from a tanker to which the present con-
vention applies, of oil or oily mixture shall be prohibited
except when —
1. The tanker is proceeding en route and is more than
50 miles from the nearest land, the instantaneous rate of
discharge of oil content from cargo carrying spaces does not
exceed 60 litres per mile and the total quantity of oil
discharged on a ballast voyage does not exceed 1/15,000 of
the total cargo carrying capacity.
2. The discharge consists of ballast from a tank which
has been effectively cleaned since cargo was last carried
therein.
These rulings are very stringent ones and have set the
major oil companies searching for an efficient and practical
oily water separator to supplement the widely practiced
policy of "load-on-top".
"Load-on-top" was pioneered by the major oil com-
panies and consists of collecting all tank washings and oil
contaminated ballast drainings in a final slop tank. A period
of time is allowed for the water and oil to separate, then
the relatively clean water is pumped to the sea until the
interface is reached. The residual oil, though it contains
high percentages of water, is retained, and the next cargo
loaded on top of it. This method has prevented gross pollu-
109
-------
110 OIL SPILL PREVENTION...
tion by crude oil carriers. There is still a chance that as the
interface in the slop tank is neared, a certain amount of oil
is liable to be carried over in the discharge of the settled
water. This possibility has led our company to study and
test other means to prevent oily water discharge.
Past experience with gravitational methods of separa-
tion has indicated that good separation so as to meet the
present IMCO standard of 100 p.p.m. or any new amend-
ments will be most difficult. InTables 1 through 5 we show
the conditions and factors that led us to feel that the
"load-on-top" method of pollution control is not as effec-
tive as is desirable. These figures indicate that even with
good weather, an excessive amount of oily water exists
below the interface and is difficult to remove by normal
gravitational separation. Table 1 shows the analysis of dirty
ballast water under adverse weather conditions during a
twenty-day ballast leg. Table 2 shows the analysis of dirty
ballast on a smooth voyage and indicates the amount of oil
in the water after five days of settling. The samples were
taken over a five hour period after the start of gravitation
into another tank. There were 1500 barrels of oil and water
left in the tank at the point where the analysis showed 500
p.p jn. oil in water.
As an example of the quantity of oil and water dealt
with during ballast and cleaning operations Table 3 shows a
typical ballast voyage with the quantities of ballast, wash
water and oil involved. A total of 136,000 barrels of oily
water was handled by the ship.
Tanks that were prepared for clean ballast were washed
and stripped into a holding tank where the mixture was
allowed to settle for 48 to 72 hours before being pumped
overboard. Table 5 shows the oil content of the water dis-
charged overboard over a period of seven days. Several
analyses were taken during each period of discharge, the
overall average being 550 p.p.m. of oil.
From the data gathered the load-on-top method of
pollution control during tank washing appeared to be un-
satisfactory. Therefore, an extensive survey was made of all
known means of separating oil and water. The methods
most widely used were those employing mechanical means
of oil and water separation and the search was concentrated
in this area. The required separator had to meet certain
criteria such as:
1. Reasonable size and weight
2. Construction for marine use
3. Automation and ease of operation
4. Throughput of approx. 2,500 bbls/hour
5. Oil content in discharge less than 100 p.p.m.
6. Ease of sludge removal
In general there were three types of mechanical separa-
tors investigated.
Coalescer or Coagulation Separators
These are very high performance type of units that
have been successfully used in lube oils and jet type fuels
Days of
Treatment
1
3
4
5
8
9
10
11
14
15
17
20
No. IIP Center
1000+
1000+
Oil layer
Oil layer
Oil layer
1000+
3000+
Oil layer
Oil layer
3000+
3000+
1000+
No. US Center
1000+
1000+
Oil layer
Oil layer
Oil layer
1000+
3000+
Oil layer
Oil layer
3000+
3000+
1000+
Sample Depth
1 meter
1 meter
1 meter
1 & 2 meters
1 meter
1 meter
1 meter
1 meter
1 meter
1 meter
1 meter
1 meter
Remarks
No. IIS oil layer
Ship is rolling
Ship rolling
Ship less rolling
Ship is rolling again
Ship rolling
Table 1: Analy sis of Ballast Water - PPM of Crude Oil in Ballast
Water
Overboard discharge of "clean" ballast water after set-
tling for seven days is shown in Table 4. It should be point-
ed out, that following standard procedures, all pipelines and
pumps had been stripped free of oil prior to overboard
discharge of any water.
for removing water and other contaminants. It is very
doubtful if a coalescer could handle a heavy oil mixture
(the heavy emulsion between the oil and water interface)
without becoming clogged with sand and scale emulsions or
passing the oil through; there is also the problem of clean-
ing the coalescing medium.
-------
GRAVITY TYPE OIL SEPARATOR 111
TIME OP
* Time
tank
SAMPLE *
1/2
1
2
3
4
(hours) Pit. COMTEMT fppTr.)
500
100
100
100
200
5 500 (10 foot level)
after start of gravitation to another
following
a settling period of 5 days
gravity type of separator using any of the above types
Table 2: Analysis of Dirty Ballast - Normal Trip - 5 Days Settling
HO. OF TANKS
33
K>. Of TANKS
6
TOTAL VOLUME OF
WATER & OIL (BBLS.)
40.000
DIR1Y BALLAST WATER
TOTAL VOLUME OF
DIRTY BALLAST (BBLS.)
96.000
VOLUME OF WATER &
OIL AFTER STRIPPING
9.000
VOLUME OF WATER &
OIL AFTER DISCHARGE
OF CLEAN WATER
6.000
Table 3: Tank Cleaning Operations
TIME FROM START OF
DISCHARGE (HOURS)
0.1
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
5.0
6.0
OIL CONTENT, ppm *
800
500
100
100
200
200
300
400
500
800
1000 (tank at 3 ft.
level)
All samples of water were taken from a slip stream
rigged from the six-inch discharge valve on the
starboard side of the ship; a small 1/2" valve was
placed in the flange plate of the discharge line
for sampling.
Table 4: Oil Content During Discharge
Flotation and Flocculation Type
The flotation type of separator injects air bubbles to
separate the mixture, which would only increase the emul-
sion problems in an oil and water separation.
The flocculation injects a chemical compound for
separation of materials. These systems are ideal for ore re-
fining techniques.
Gravity Type Separators
This type of separator is ideal as it meets most of the
criteria set up by our studies and others. We eliminated any
DATE
11/27/66
11/28/66
11/29/66
11/30/66
12/1/66
12/2/66
12/3/66
DEPTH OF WATER OIL CONTENT
DISCHARGED * »ur= - oPH
6
14
17
14
26
20
10
* "Depth of water
ft.
ft.
ft.
ft.
ft.
ft.
ft.
discharged" means
300
500
400
500
500
750
900
the amount of water removed from
the tank.
Table 5: Oil Content During Settling
Those operating under vacuum or pressure or involving
electrical voltages were also discarded by our work. Centri-
fugal separators were also eliminated as some of the crude
oil emulsions were impossible to break in laboratory centri-
fuges.
These are several manufacturers of gravity type separa-
tors both in continental Europe, Asia and the U.S.A. It is
not the object of this paper to discriminate between the
various types of gravity separators. In most cases the design
is somewhat different but the basic principle is the same,
i.e., a large surface area is needed to separate the oil from
the water and the natural buoyancy of oil in water tends to
aid the separation.
The performance of the separator depends in large part
upon such factors as the oil content at the inlet, the roll of
the ship, water temperature, type of oil, piping arrange-
ment, slope of the separator, and the history of the oil to
be separated; i.e., the number of times, and when the oil
passed through the pump system.
We decided to use the SEREP separator which was
developed by P. Cheysson, the Director of the Sometran
research and tank-cleaning installation in LeHavre, France
and has been developed over the last ten years. The name
SEREP is derived from the words "Societe d'Etudes et de
Realisations d'Equipements Petroliers".
In 1967, Butterworth System, Inc. bought the patent
rights of the SEREP separator, and it is now marketed
under the name Butterworth outside continental Europe.
We have installed and operated three SEREP T-24 Separa-
tors, rated at 250 tons per hour.
These separators were installed on three 70,000 DWT
company tankers, the S.S."W. ALTON JONES" in 1967,
the S.S."BURL S. WATSON" in 1968 and the S.S."J. ED.
WARREN" in 1969.
The installation and piping were carried out as recom-
mended by the specification and guidance drawings to
insure that the separator was placed so that the oil outlet
was in a fore and aft line leading forward, utilizing the
normal stern trim of the ship to aid in oil recovery. The
recovered oil outlet line was installed as vertically as possi-
-------
•112 OIL SPILL PREVENTION...
ble from the separator to our slop oil tank, thus minimizing
any lengths of horizontal piping.
The separator was placed at the after end of the main
deck on the port side just aft of the last port center tank.
The ship has a slop oil tank located in 13 port center and
the relationship of the separator and slop oil tank is shown
in Figure 1.
The separator used on these 70,000 DWT tankers is the
SEREP T-24 and has the following dimensions:
OKICT MCOVERV
VENT-
r«- INLET
wCLEAN WATER
DROP LINE
TO TANK
SUCTION TO CRUDE
OIL SERVICE PUMP
Separator/Slop Tank Arrangement
250 ton/hr.
14 ft. 7 in.
7 ft. 11 in.
Figure 1:
Capacity
Height
Diameter
Weight:
Dry 11,900 Ibs.
Operating 43,000 Ibs.
At the present there are 18 SEREP/Butterworth T-24
separators in operation on various tankers. Some six larger
T-27 units (300 tons/hr.) have been installed on larger tank-
ers.
The T-24 separator is shown in a cut-away view in
Figure 2 with identification of the various parts. Figure 3
illustrates the way in which the oily water mixture is sep-
arated.
In the separator, the oil water mixture to be separated
is delivered through the inlet (1) to the upper part of the
apparatus. This mixture undergoes deaeration and a first
rough separation in the upper part of the separator, and the
separated oil flows directly into the oil recovery chamber
(14).
MIXTURE INLFT
2nd Stage
Recovery
Chamber
INT FlUSHtK,
CONNCCTION
SLUDGE OUTLET
Figure 2: SEREP/Butterworth T-24 Separator
VENT
OIL/WATER MIXTURE IN
MAIN
Figure 3: SEREP/Butterworth Oil/Water Separator
The remaining partly separated mixture flows down
through an annular space (2) to the bottom of the separator
and then through the opening (3) into the compartment (4)
-------
GRAVITY TYPE OIL SEPARATOR 113
SEPARATOR REPORT
Voy.
63
s/S
DATE
H«v. 26,
1970
•
*
Dec. 1,
1970
•
H
II
»
*
N
•
n
•
•
•
*
•
*
*
H
SAMPLING
T3ME(AKvt«fl
1400
1500
1600
0100
0200
0300
0400
0500
0600
0700
0800
0900
1000
1100
1200
1300
1400
1500
1600
1700
P.P.M.
DISCHARGE
200
200
150
50
50
50
100
200
200
200
20C
150
150
100
50
150
100
50
50
150
STRIP. PUMP
DISCH L/THR.
200
IT
n
200
n
n
N
N
II
II
»
N
H
»
n
n
N
»
»
n
AVERAGE
SPEED VESSE]
15.40
n
It!
15.26
n
it
it
N
Hi
It
It,
l»
It
»
It-
IT
15.00
»
n
»
Pase 1 of 3
REMARKS: (include)
(1)(AFI Gravity of Crude)
(2) (Identity of Tanks Cleaned)
(3) (Ho. EBIS. Recovered Slop Oil)
CO (Dirty Ballast Tanks)
(1) API - 34.3
(2) AH tanks
(3) Slop oil recovered, 400 BBLs for
burning and 1200 BBLs pumping
ashore at gas free station,
Marseille.
(Li Dirtv Ballast Tanks t 1.6.7 and
11 centers
CHIEF ENGINEER
CHIEF MATE
MASTER
Figure 4: Typical Separator Report, Page 1
-------
114
OIL SPILL PREVENTION...
SEPARATOR REPORT
Voy. # 63 B/P
S/S J. ED. WARREM
Page 2 of 3
DATE
Dee 1,
1970
N
»
»
•
»
•
Dae 2,
1970
•
N
H
*
•
•
»
•
•
•
II
H
SAMPLING
TBffif/iKvfifl
1800
1900
2000
2100
2200
2300
2400
0100
0200
0300
0400
0500
0600
0700
0800
0900
1000
1100
1200
1300
P.P.M.
DISCHARGE
100
50
50
150
50
50
50
50
150
50
50
50
50
200
200
100
100
50
150
100
STRIP. PUMP
DISCH L/THR.
200
*
•
*
•
m
n
•
*
N
•
H
N
*
II
•
m
*
N
*
AVERAGE
SPEED VESSE:
15.26.
H
•
*
li-
ft
It
14.92
H
•
»
»
»
•
»
»
»
•
»
H
REMARKS: (include)
(1)(API Gravity of Crude)
(2) (Identity of Tanks Cleaned)
(3) (Ho. BBLS. Recovered Slop Oil)
CO (Dirty Ballast Tanks)
CHTKF ENGINEER
c.H I Ki«' MATE
MASTER
Figure 5: Typical Separator Report, Page 2
-------
GRAVITY TYPE OIL SEPARATOR
SEPARATOR REPORT
Voy. # 63
s/S
Page 3 •* 3
DATE
Dec 2,
1970
»
•
•
•
•
•
SAMPLING
TIME(AKvt«fl
1400
1500
1600
1700
1800
1900
2000
P.P.M.
DISCHARGE
50
50
50
150
100
50
50
STRIP. PUMP
DISCH L/THR.
200
n
n
N
II
•
N
AVERAGE
SPEED VESSE]
14.92
H
»
»
IT
•
N
REMARKS: (include)
(1)(AFI Gravity of Crude)
(2) (Identity of Tanks Cleaned)
(3) (No. BBU3. Recovered Slop Oil)
CO (Dirty Ballast Tanks)
CHIEF ENGINEER
CHIEF MATE
MASTER
Figure 6: Typical Separator Report, Page 3
-------
116 OIL SPILL PREVENTION...
between the bottom cone and the second stage cone and
then is diffused at (5) where it undergoes another separa-
tion. Much of the oil in the form of small droplets is
retained by the ring of blades placed in the way of the
diffuser. These small droplets coalesce and rise up the
blades, increasing in size until their buoyancy is sufficient
to float off the tip of the blades. This oil collects at (6) and
then flows upward in the oil recovery column (11) and
enters the oil recovery chamber. The nearly oil-free mixture
then flows through the conduit (7) to enter the compart-
ment (8) from where it is diffused again at (9).
The last oil particles similarly are caught by the blades
of the second stage, are collected at (10) and flow upwards
in the adjustable weir (12) and finally into the oil recovery
chamber.
The clean water rises through funnel (13) and flows
over its lip to the water outlet.
The surface of the water above the lip of funnel (13)
establishes a reference level above which the oil in the oil
recovery columns rises to a height which is related to the
difference in density of the two liquids, i.e., oil and water.
The oil in the recovery columns flows into the oil recovery
chamber over weirs set higher than the water reference level
but lower than the maximum height to which the oil
columns will rise. If pure oil or grossly contaminated water
enters the separator, the free oil will not pass down to the
bottom of the separator but will flow directly to the oil
recovery chamber (14).
The oily water mixture is fed directly to the separator
by a 6 inch line from the stripping pump discharge line in
the pumproom. Recovered oil from the separator drops by
a 12 inch line to No. 13 port center chemical tank (2,000
bbl capacity) through the main deck and the outlet is
placed just off the bottom of chemical tank. The
clean-water flows through a 10 inch line with a 10" gate
valve and then over the side and through a canvas sleeve to
the sea.
The separator and the associated steel work were
coated with white paint and the unit blends fairly well with
the rest of the ship. The unit has been firmly supported and
bracketed and the piping also provides some support to the
separator.
One half inch sampling valves were placed on the oil
and water discharge lines for test purposes. Our procedures
for these tests were given in a paper, "Combustion of Crude
Oil in Ships Boilers", presented at the API Tanker Con-
ference on May 15 -17,1967 by Bassett & Norris.
This paper covers three 70,000 DWT tankers using the
SEREP T-24 separator over some 44 voyages during a three
year period. Some 20 voyages have been used in the calcula-
tions for this paper. The other 24 voyages were not used
because in the beginning the ships' reports did not cover the
number of samples taken, the number of tanks cleaned or
the number ballasted. The only data recorded was the num-
ber of barrels of slop oil burned.
Our ships must send a report on data collected during tors.
the ballast voyage on the separator operation. Figures 4, 5
and 6 show a typical operation report. The only thing unu-
sual in this report is that 1,200 bbls of burnable slop oil was
pumped ashore when the ship arrived for repairs. Due to
insufficient time between ports all of the slop oil could not
be burned. However, 400 bbls were burned at sea prior to
arrival.
Over a period of three years data has been accumulated
on the amount of slop oil recovered from separator opera-
tions on three 70,000 DWT tankers. The average amount of
burnable slop oil recovered is 1,200 to 1,500 bbls per trip.
Table 6 shows the amount of slop oil recovered for each of
the three ships during the period 1967 through 1970.
Tables 7, 8 & 9 show the relationship between p.p.m.
oil discharge, rate of discharge and the permissible dis-
charge of 60 liters per mile or 1/15,000 of the total cargo
carrying capacity. As the three ships involved have a
500,000 bbl capacity, then a total of 33 bbls discharge is
permissible
Compilation of Tables 7,8 & 9 shows an average of 2.6
liters of oil discharged per nautical mile and an average of
7.8 bbls of total oil discharged per voyage. The total
amount of oil retained onboard from the three ships over a
three-year period was 45,058 bbls.
From the data presented it can readily be seen that the
T-24 separator can be used as a reliable and simple method
of separating oil and water in shipboard operations. This
method separates the emulsion layer easily from the re-
latively clean water from either a holding tank or directly
from cleaning operations. The oily emulsion is discharged
along with oil and can later be separated. We have found
that the separator works very well from 190 - 220 tons per
hour, with very good quality water obtained at 150 tons
per hour. We are not sure how far to go in practice, because
we feel that on these ships the oil discharge to sea has been
drastically cut with a minimum of ship's personnel and
time. As we discharge from tank cleaning directly to the
separator, we eliminate a slop oil tank. We have been able
to clean all tanks on these ships obtaining some 2,500 bar-
rels of slop oil containing 30 - 50 per cent sea water. This
could be a "load-on-top" operation now. This oil is then
treated with an emulsion breaker and allowed to settle in a
heated tank, until the quality is such that the oil can be
burned; that is with less than 2% water and less than 20#per
1,000 barrels. These tests are run by the Engineering De-
partment. For a shipyard voyage we can arrive at the yard
with only our slop oil tank dirty and not gas free as it may
contain oil not burned in the ship's boilers.
The data shows that this type of separator is about
95% efficient (60 liters vs. 3 liters) staying well below the
maximum discharge of 60 liters per nautical mile.
CONCLUSIONS
1. SEREP/Butterworth T-24 is an efficient oily water
separator.
2. IMCO Amendments can fully be met by Tanker Opera-
-------
GRAVITY TYPE OIL SEPARATOR
117
3. Improvements or additions are needed for the separation
of waxy crudes and heavy No. 6 oils from water.
4. Need automatic instrumentation for analyzing discharge
streams. We have not discussed this need in this paper but
the authors and ship personnel have a great need for an
instrument that would analyze a discharge stream without
taking samples and running a chemical extraction vs. a set
of oil standards.
OIL CONTENT IN RATE
DISCHARGE, ppm** Ton/
TOTAL
BBL OIL
DISCHARGED LITERS/NAUTICAL
TO SEA MILE
RECOVERED SLOP OIL
NO. OF
SHIP VOYAGES
». ALTOS JONES 20
BURL S. WATSON 18
J. ED. BARREN 6
TOTAL! 45,058
RECOVERED
SLOP OIL. BBLS.
23,074
16.884
5,100
bbls or 6,437 tons
DATE SEPARATOR
INSTALLED
1967
1968
1969
51
54
57
60
61
62
64
65 •
481
290
3?2
265
353
289
404
1000
194
200
120
213
225
125
40
64
13.48
5.66
3. 14
6.01
10.20
6.21
10.44
33
6.10
3.59
2.67
2.89
5.10
2.40
0.35
3.80
* The cargo for this voyage vas a
heavy wax like crude, which causes
trouble in separators. There is a
need for additional heating coils
in this type of service,
** Ave of 20-40 analysis
Table 8: S.S. "Burl S. Watson" - Separator Data
VOYAGE
NO.
57
se
59
60
62
63 «
Table 6:
OIL CONTENT IN'
DISCHARGE, ppm
318
150
129
131
135
103
Recov
RATE
Ton/Hr .
200
200
200
200
200
200
'ered Slop On
TOTAL
BBL OIL
DISCHARGED
TO SEA
9.86
4.69
5.92
4.82
3.88
5.84
VOYAGE (
NO. I
LITERS/NAUTICAL
MILE
61 *
4.52 67
1.99 68
1.92 69
1.81 70
1.83
1.52
TOTAL
BBL OIL
)IL CONTENT IN- RATE DISCHARGED LITERS/NAUTICAL
vrgf-HARf-.P , ppm" TON/RR. TO SEA MILE
-
110 117 3.42 0.85
92 68 3.55 0.42
133 103 5.27 0.97
250 125 5.7 1.12
* This voyage was with #6 fuel oil which
separation, i.e., larger heating coils..
Voyage 63 - All tanks cleaned for shipyard.
* Ave of Z0-40 analysis
** Ave of 20-40 analysis
Table 9: S.S. "W. Alton Jones" - Separator Data
Table 7: S.S. "J. Ed. Warren" - Separator Data
-------
IDENTIFICATION OF OIL LEAKS
AND SPILLS
R.E. Kreider
Standard Oil Company of California
ABSTRACT
Development of a tentative method of comparison of
unknown petroleum leaks and spills with known sources is
reported. Methods of sampling and preparation of a residue,
free of water and solids, equivalent to a 24-hour weathered
sample are described. The principal method of analysis is
high-resolution temperature programmed gas
chromatography. Additional analyses considered are sulfur,
nitrogen, nickel, vanadium and infrared. Analyses of
samples by 10 cooperating laboratories are reported.
INTRODUCTION
In October, 1969,the Western Oil and Gas Association
initiated a subcommittee of their Air and Water
Conservation Committee for the purpose of developing
methods of sampling and analysis of spilled oil to establish
its identity. Ten major oil companies are cooperating in
the work. The number of participants has recently
increased to include four commerical laboratories and one
government laboratory. Fifteen laboratories are currently
analyzing six samples according to the method developed
thus far (Appendix 1). This work should be completed and
evaluated for reporting at the Conference. The method is
subject to change depending upon that evaluation.
It has been the intent of the committee to develop
rapid methods that will be useful to oil companies,
independent and government laboratories alike. This has
been done without the use of extremely costly laboratory
equipment. It is possible that some cases may require the
use of elaborate techniques such as mass spectroscopy,
nuclear magnetic resonance, and carbon isotope analysis.
Neutron activation analysis for a number of trace elements
is being used on samples for the U.S. Coast Guard and other
Federal agencies. Infrared analysis has been used by some
investigators for analysis of slicks and spills,l-3 however,
the committee feels that gas chromatography is a much
more useful technique. Infrared apparatus is commonly
available and may be another useful means of identification
in certain cases. The British Institute of Petroleum4 has
published a compilation of methods related to the subject
of analysis of beach pollutants. There is considerable
similarity in their approach to that of the Western Oil and
Gas Association, however, they describe some additional
tests that are elaborate and time consuming. A novel
approach using fluorescence spectroscopy has been
published.5 It may be useful in a small area investigation,
but it may be lacking when applied to a broad area.
Based upon the experience of the committee and upon
the literature,6-8 it was decided to rely heavily on high
resolution gas chromatography. Using standard conditions,
gas chromatography has been extremely useful in
controlling losses to refinery drainage systems by visual
comparison of chromatograms of unknowns with
chromatograms of knowns, ranging from gasoline to crude
oil and bunker fuel. In a refinery, the bigger the system, the
more complex some samples become, but frequently some
portion of the sample is distinctive enough for
identification of that portion to be made. If a
chromatogram of a sample does not match any
chromatogram in the reference file, there is still
considerable information that can be gained by inspection
of the chromatogram, depending upon experience. This
includes boiling range if it is a distillate, whether it is a
crude oil or a residual fuel, whether it is waxy as indicated
by high carbon number normal paraffins, or whether the
cutter is straight run or cracked stock.
In a bigger area, such as a bay or ocean, the gas
chromatographic technique is not the only answer to
identification of spills. The proposed method will also use
sulfur, nitrogen, nickel and vanadium contents and possibly
infrared analysis. While sulfur, nickel and vanadium are
frequently included in such analyses, nitrogen is included
because of its relatively high concentration in some
California crude oils.
119
-------
120 OIL SPILL PREVENTION
Treatment
One problem of slick and spill analysis is that such
samples are weathered, the extent of which depends upon
the conditions of exposure. This can seriously affect
elemental analyses and other analyses in relation to those of
an unweathered sample.
In simulated weathering, a crude oil lost essentially all
of its light ends boiling up to Ci2 (216°C) in 24 hours. The
simulation consisted of pouring a pint of crude oil onto the
surface of a barrel of sea water exposed to the weather. The
oil was sampled on successive days for gas chromatographic
analysis. The extent of weathering increases with time,
however, when the lighter hydrocarbons have weathered,
the semi-solid portion weathers at a slower rate (Figure 1).
Subsequent work showed that thinner films weather more
quickly. (Figure 2). One sample known to have been on San
Francisco Bay for five days lost hydrocarbons up to C\2< It
is impossible to simulate all conditions of weathering, but
the case of 24 hours seems to be a reasonable choice. The
committee chose to simulate such weathering by distilling
all samples, including reference samples, to 282°C liquid
temperature in ASTM distillation equipment,9 using an
inert gas flow to reduce thermal decomposition. Without
the inert gas, a liquid temperature of 315°C was used earlier
and slight cracking occurred in some samples. The similarity
between simulated weathering and the weathering achieved
by distillation is shown in Figure 3.
Samples picked up from the water or the beach will
probably be contaminated with water and solids. All
samples are dissolved in an equal volume of chloroform and
the solution centrifuged to separate solids and water. Water
is aspirated from the surface and the clear solution distilled
as described in the method. The residue is .cooled and
poured into suitable containers for analysis.
2.5r
CN
Figure 1: Effect of Time on Weathering, 0.5 mm
Initial Film Thickness
2.0
CM
O
« 1.5
j=
= 1.0
j*
o>
Q.
I °'5
CD
O>
Initial Film Thickness
aim
1 L
18
12
16 14
CN
Figure 2: Effect of Film Thickness on 24-Hour Weathering
10
o
~z
o
1.9 mm Film
24 Hr
Q.
o>
CO
o:
282°C. N2
15 ml/Min.
CN
Figure 3: Comparison of Simulated Weathering
Distillation and Weathering by
Analysis
The first set of samples exchanged by the participants
was analyzed by the best methods the individual members
had available. A second set of samples was analyzed by
more definite procedures. The most specific section of the
method is to obtain a chromatogram of the prepared
sample residue under conditions capable of partial
resolution of double peaks at both €17 and C]g positions.
These two double peaks occur in many, but not all crude
oils and are shown in Figure 4. Using the non-polar or
boiling point column described in the method, in the
manner described, will accomplish the desired resolution.
Performance of the column should be checked periodically
with a known sample to follow deterioration of the
column.
-------
IDENTIFICATION OF SPILLS AND LEAKS 121
The chromatogram of the sample of unknown origin is
compared visually to chromatograms of samples of known
origin (Figures 5, 6). Visual comparison is adequate in
limited situations, however,its capability is taxed in a large
refinery and is exceeded in a multi-refinery or larger area.
The participants are currently working on the application
of computer techniques to the problem. Computer
technique is available, however,the immediate problem is in
obtaining data for use of the computer. The chromatograms
do not return to baseline and obtaining useful simultaneous
digital data from them will require some ingenuity.
Results
In mid-1970 the participants reviewed analyses of their
second set of samples. Complete conformity to the
conditions prescribed for gas chrornatography had not been
achieved, due to limitations of available equipment.
however, most laboratories met or exceeded the desired
resolution.
Elemental analyses of the second set of samples are
shown in Tables 1-4. Assuming samples E and F, and G and
H to be duplicates and excluding the values for nickel and
30 25
Time, Win.
20
l-igure 4: Partial Chromatogram of Mixed Crude
1 Mmas Crude
20 I 18 , 16
vanadium from a commerical laboratory, only 5 of 140
values exceeded 95% confidence limits. The standard
deviations for sulfur and nitrogen are from 5 to 7% of their
means, but those for nickel and vanadium are from 12 to
17% which is rather high. This indicates that experience and
strict attention to the details of any method are necessary
for satisfactory determination of nickel and vanadium.
APPENDIX I
WOGA Method for Analysis of Beach
Pollutants, 11-1-70
Identification
Identification, or denial of identity, is by comparison
of data from analyses of an unknown oil with comparable
data from known oils, selected because of their possible
relationship to the particular pollution incident; for
example, suspected, accused, or questioned sources. Thus,
San Joaquin Heavy Crude
"'.< c,,
San Ardo Crude
Time. Mi n
Figure 6: Comparison of Naphthenic Crudes
Sample
Company
1
2
3
4
5
6
7
8
9
Method
X-Ray Fluorescence
Combustion-Turbidity
Combustion-Titration
Combustion -Titration
Combustion-Turbidity
X-Ray Fluorescence
Combustion-Titration
X-Ray Fluorescence
Combustion-Titration
Mean
E
1.48
1.60
1.60
1.36
1.47
1.41
1.47
1.45
1.26
1.47
F
1.47
1.63
1.60
1.35
1.46
1.44
1.52
1.54
1.36
1.47
G
1.58
1.56
1.81
1.45
1.58
1.73
1.58
1.60
1.49
1.58
H
1.58
1.60
1.64
1.47
1.52
1.67
1.68
1.58
1.36
1.58
•igure 5: Comparison ot'Paraffinic Crudes
Table 1: Percent Sulfer in Exchange Samples
-------
122 OIL SPILL PREVENTION
samples of such known oils must be collected and should be
submitted along with the unknown for analysis at the same
time. At present, identification of the source of a
weathered unknown oil sample by itself cannot be made
since a file of comparable data from weathered known oils
is not yet available.
One certain difference between unknown and known is
enough to deny identity; several moderately certain
differences may also suffice. Many close similarities (within
the uncertainties of analyses and samples) will be needed to
establish identity beyond reasonable doubt. The analyses
described below will distinguish many but not all samples.
For cases in which these analyses do not clearly distinguish
a pair of samples, and for important cases where additional
comparisons are needed to strengthen confidence in
conclusions, other analyses beyond those described in this
method will be required.
Sample
Company E F G H
1 0.91 0.92 0.99 1.02
2 0.99 1.01 ) 06 1.05
3 0.89 0.93 1.03 0.95
4 0.92 0.81 0.98 1.05
5 0.92 0.93 1.04 1.04
6 0.95 0.93 1.06 1.04
7 0.94 0.93 1.06 1.08
8 0.77 0.99 0.89 1.06
9 0.94 0.94 1.06 1.07
Mean 0.92 0.93 1.04 1.05
Samole
Company
1
2
3
4
5
6
7
8
9
Method
X-Ray Fluorescence
Atomic Absorption
Emission Spectroscopy
Emission Spectroscopy
X-Ray Fluorescence
Colorimetric
Emission Spectroscopy
X-Ray Fluorescence
Emission Spectroscopy
Colorimetric
Mean
E
138
150
26
140
211
165
135
187
140
148
148
Table 3: PPM Nickel in Exchange
F
141
143
80
150
216
160
134
169
145
140
145
Samples
G
113
110
27
170
179
123
105
148
115
120
120
H
113
99
17
135
133
120
110
147
110
120
120
Sample
Company
1
2
3
4
5
6
7
8
9
Method
X-Ray Fluorescence
Emission Spectroscopy
Emission Spectroscopy
X-Ray Fluorescence
Colorimetric
Emission Spectroscopy
X-Ray Fluorescence
Emission Spectroscopy
Colorimetric
Mean
E
33
32
30
38
37
34
38
40
40
37
F
34
73
30
38
35
27
41
40
29
35
G
120
57
170
158
118
134
140
100
132
134
H
ID
48
155
159
IB
142
D9
100
124
D9
Table 2: Percent Nitrogen in Exchange Samples
Sampling
It is desirable to get from 4-oz. to a pint of
representative sample of oil to the laboratory in a
previously clean container that can be closed securely. This
can be done by skimming into the container and, after
settling a short while, inverting the closed container to
drain water by cautiously opening the closure. The
container can be filled by further skimming. A more
elaborate device such as a separatory funnel could be used
to obtain a maximum of oil and a minimum of water.
If only a small amount of sample is available, or if it is a
very thin film on water, it may be picked up with glass
doth that has been treated for use in boat hulls and auto
Table 4: PPM Vanadium in Exchange Samples.
bodies. The lightest and cheapest grade (2 oz. duck) is suit-
able. Lay a square on the film, pick it up, and place it in a
clean container and close securely. A piece of new cloth
from the same source should be enclosed in another clean
container as a control. Additional methods of sampling are
described in a recent Federal publication.^
The choice of container and closure is important and
the following should be considered:
1. Container: First choice is glass, preferably new, though
used glass containers cleaned with detergent and thoroughly
washed with water are satisfactory. Second choice is a new
tin coated can. Resin coated cans, rusted cans and plastic
containers should not be used.
-------
IDENTIFICATION OF SPILLS AND LEAKS 123
"2. Closure: For wide mouth bottles and screw cap cans,
caps with aluminum coated cardboard inserts are preferred.
Aluminum foil should not be used because it will probably
leak. Second choice is a plastic coated cardboard insert.
Saran Wrap may make a satisfactory seal for an otherwise
unsatisfactory cap. Wax coated cardboard inserts should
not be used. Tin coated friction lids can be used on some
cans. For narrow necked bottles, new or clean corks are
satisfactory, but rubber stoppers should not be used.
3. Labeling: It is important that samples be properly
identified as to date, time and exact location of origin,
along with the name of the person taking the sample. It
may be desirable to include the name of a witness to the
sampling.
Shipment
Flammables, i.e., flash point less than 27°C, cannot be
shipped by U.S. mail, however, they can be shipped by
common carrier. Non-flammable liquids can be shipped by
mail if adequate protection against breakage and sufficient
absorbent packing are provided to protect other mail in
case of breakage. Samples as large as a quart may require
special handling.
Treatment
Dissolve approximately 100 ml of the oil sample in an
equal volume of chloroform. If the sample is waxy, warm
the solution, including the centrifuge tube and shield, to
60°C to prevent precipitation of wax. Centrifuge the
solution according to ASTM Method D-96 to separate free
water and sediment. Aspirate the free water and decant
about 100 ml of the treated solution to a chemically clean
ASTM D-1078 flask. If there is an intermediate layer of
solids between the water and chloroform, aspirate the free
water and decant through a loose plug of glass wool to
remove the solids. Insert an ASTM high distillation
thermometer (8C) to 6 mm from the bottom of the flask.
Also insert a 4 mm O.D. by 2 mm I.D. glass tube to the
same depth but with the bottom 5 cm bent about 20° to
direct the flow of nitrogen away from the thermometer
bulb. Start a nitrogen gas flow of 10-15 ml per minute
through the tube and distill in ASTM E-133 equipment to a
liquid temperature of 282°C. Continue the gas flow until
the liquid has cooled to 175°C and pour the residue into
suitable containers for analysis. If more treated sample is
needed, add more treated chloroform solution and repeat
the distillation.
Reference samples are to be treated in the same
manner as spill samples.
The prepared sample is to be used in the following
analyses and results reported on that basis.
Gas Chromatography
The following conditions should be adhered to as
dosely as practicable with the best equipment available:
Conditions:
Injector Temperature:
Detector Temperature:
325°C
350°C
Flow Rate: 20 ml/min.
Initial Temperature: 50°C
Final Temperature: 325°C
Temperature Rate: 6°C/min.
Chart Speed: 1.25 cm./min.
Column:
Support: 80/100 mesh Chromosorb W (AW-DMCS)
Substrate: 10% OV-101
Length: 3 m stainless steel
Diameter: 3.2 mm x 0.3 mm
Chromatograms are to be obtained at a single
attenuation so that the highest peaks are at approximately
3/4 of full scale on the recorder. The final temperature
should be held until Csg or C4fj has been eluted. The
resulting chromatograms can be used for visual comparison
of sample and suspect sources.
Samples too viscous for injection into the
chromatograph may be diluted with chloroform. Partial
resolution of double peaks occurring at both Cn and Cjg
positions is the primary measure of column performance
(Figure 4). These peaks occur in many, but not all crude
oils. Each laboratory should select a sample that can be run
periodically to follow the deterioration of the column
under these conditions. When resolution of the Ci7 and
CIB pairs is no longer adequate, the column should be
replaced.
Information as to the extent of weathering and the
nautre of the sample can be obtained more rapidly by gas
chromatography of the initial chloroform solution. The
object of the distillation procedure is to remove the
chloroform and to simulate approximately 24-hour
weathering so that elemental analyses are on a relatively
constant basis.
Sulfur
Determine sulfur by any desirable ASTM procedure.
Precaution should be taken against erroneous results by
chloride interference in combustion procedures.
Nitrogen
Determine nitrogen by Kjeldahl procedure.
Nickel and Vanadium
Determine nickel and vanadium by appropriate
methods provided that precaution against matrix effects are
used in X-ray and emission spectroscopy methods. If ashing
techniques are used in preparing concentrates, precaution
against loss by volatilization must be used in the form of
prior treatment with sulfuric acid,H"13 sulfur,^
benzene sulfonic acidlS or equivalent. If determinations of
other metals, particularly cobalt, copper and manganese are
conveniently available, report them also.
Ratios
Use of sulfur/nitrogen or nickel/vanadium ratios should
be approached with caution, especially if an element is
being determined near its limit of detection by a particular
method. When reasonably precise quantities have been
-------
124 OIL SPILL PREVENTION ...
determined, useful ratios may be obtained. Ratios should
not be reported unless absolute values for individual
elements are also reported.
Infrared
If infrared spectra are determined, use thin films of the
prepared sample residue between sodium chloride plates.
More than one thickness will probably be required to
obtain optimum spectra throughout the 2-15 micron
region; one spectrum should have more than 10%
transmission for the major bands and another should be
with a thicker film to emphasize the minor bands. Spectra
can be compared visually.
REFERENCES
1. Kawahara, F.K., "Laboratory Guide for the
Identification of Petroleum Products", U.S. Dept. of
Interior, FWPCA, Cincinnati, Ohio (1969).
2. Mattson, J.S., et al, "A Rapid Nondestruction Technique
for Infrared Identification of Crude Oils by Internal
Reflection Spectrometry",^nai Chem. 42:234 (1970).
3. Kawahara, F.K., and Ballinger, D.G., "Characterization
of Oil Slicks on Surface Waters", Ind. Eng. Chem. Prod.
Res. Develop. 9:553 (1970).
4. Institute of Petroleum Standardization Committee,
"Analytical Methods for Identification of the Source of
Pollution by Oil of the Seas, Rivers, and Beaches", /. Inst.
Petrol. 56:107(1970).
5. Thruston, A.D., and Knight, R.W., "Characterization of
Crude and Residual-Type Oils by Fluorescence
Spectroscopy",£>m>0H. Sci. Technol. 5:64(1971).
6. Cole, R.D., "Identification of Slop Oils-an Aid in
Tracing Refinery Oil Leaks",/. 7ns/. Petrol. 10:288(1968).
7. Brunnock, J.V. Buckworth, D.F., and Stephens, G.G.,
"Analysis of Beach Pollutants", ibid, S4: 310 (1968).
8. Ramsdale, S.J., and Wilkinson, R.E., "Identification of
Petroleum Sources of Beach Pollutants by Gas-Liquid Chro-
matography", ibid, 54:326 (1968).
9. American Soc. Testing Materials, ASTM Std. 17:1214
American Soc. Testing Materials, Philadelphia (1970).
10. Federal Water Pollution Control Administration, "Oil
Sampling Techniques". Water Poll. Cont. Res. Serv.
DAST-12, 15080 QBJ (1969).
11. Milner, O.I., et al, "Determination of Trace Metals in
Crude and Other Petroleum Oils", Anal. Chem. 24:1928
(1952).
12. Gamble, L.W., and Jones, W.H., "Determination of
Trace Metals in Petroleum", ibid, 27:1456 (1955).
13. McCoy, J.W., "Inorganic Analysis of Petroleum", pp.
180-183, Chemical Publishing Co., New York (1962).
14. Agazzi, E.J., et al. "Determination of Trace Metals in
Oils by Sulfur Incineration and Spectrophotometric
Measurement", Anal. Chem. 55:332(1963).
15. Shott, J.E., Garland, TJ., and Clark, R.O.,
"Determination of Traces of Nickel and Vanadium in
Petroleum Distillates", ibid, 33:506 (1961).
-------
BALLAST WATER TREATMENT: A MAJOR
UNDERTAKING
Jonathan W. Scribner
Division of Environmental Health
Department of Health & Welfare
State of Alaska
ABSTRACT
Port Valdez is an important fishery resource area located
at the proposed terminus of a 48 inch diameter, 800 mile,
crude oil pipeline system. This terminus facility will provide
for the transfer of crude oil to large oil tankers for
shipment to the "lower 48" and will also provide for the
treatment of oily ballast water from incoming vessels. The
degree of treatment required by State and Federal agencies
will limit the treated effluent water to 10 mg/1 total oil
content. This is considered to be as stringent a requirement
as exists for a similar facility anywhere in the world and
was imposed upon the industry to ensure maximum
protection of marine life. The treatment facility will consist
of primary gravity separation, secondary dissohed-air flota-
tion with the addition of chemicals and an outfall/diffuser
system terminating in Port Valdez at a depth greater than
100 feet.
INTRODUCTION
Vast crude oil discoveries on the North Slope Alaska
contemplate enormous impact upon the State of Alaska.
At the present time, there is a plan to transport these
crude oil reserves (estimated in the tens of billions of
barrels) southward across the State of Alaska via an 800
mile, 48 inch diameter pipeline to a terminal facility to be
located at Port Valdez, Alaska. From this terminal facility,
the oil will be transferred to oil tankers varying in size
from 16,000 to 250,000 DWT vessels and transported to
oil refineries located along the Pacific-coasts of Washington,
Oregon and California at the rate of 2 million barrels per
day.
This plan is receiving extremely close scrutiny from a
number of private and governmental entities in the United
States. Professing concern for the environment, critics are
attacking and analyzing the project for its economic, social
and political impact upon Alaska and upon the nation as
well.
Three dominant points of view are evident. One says the
oil reserves of Alaska should never be developed and insist
that Alaska become a vast national park preserved for
future generations to enjoy. Another group, more con-
cerned with economics, insists on immediate development
of Alaska's natural resources for development's sake. The
third position expresses concern for the environment saying
that development should and must occur only when strict
environmental safeguards are integrated into the entire
project.
It is not the intention of this paper to deal in depth with
these many interesting ideas. Instead, this paper will focus
upon one small but very important portion of the entire
project. This is the ballast water treatment facility to be
located at the pipeline terminus. It is small in terms of the
total $1.5 billion project and important because this ballast
water treatment facility is the largest known facility of its
kind designed to protect an important fishery resource in
the Valdez Area and will serve to eliminate unlawful
discharge of oily ballast water at sea.
This paper has three objectives:
1. To provide the environmental background of Valdez
Harbor1 which served as the basis for the design of the
ballast water treatment facility;
2. To discuss the applicable laws and regulations govern-
ing the control of oil pollution as they relate to this project
from the point of view of the State regulatory agency; and
3. To describe the method and efficacy of the ballast
water treatment facility.
125
-------
126 Ol L SPILL PR EVENTION ...
BACKGROUND
In December 1969, the University of Alaska Institutes of
Marine Science and Water Resources, (supported by the
Trans Alaska Pipeline System), (now the Alyeska Pipeline
Service Company), completed a baseline environmental
study of Port Valdez. This initial report quite under-
standably lacks much detailed information, yet it provides a
valuable aid for the development and design of the terminal
facilities.
Port Valdez is located in southcentral Alaska and is a
typical fiord estuary commonly studied in other parts of
Alaska. It is surrounded by sharply rising mountains
consisting predominantly of rock outcrops as high as 6,500
feet.
The City of Valdez (population approximately 1,000) is
situated on the northeastern shore of Port Valdez. Magnifi-
cant scenery and excellent salmon fishing are primary
reasons that tourism is the most active business. In
addition, Valdez is the terminus of the Richardson High-
way, long an access route to interior Alaska. Sewage from
the municipal sewage treatment system represents the only
present significant waste discharge into the entire estuary.
Extreme air temperatures range from -28' to 87°F. with
the average daily maximum being 43°F. and the average
daily minimum being 29°F. Annual mean precipitation is 62
inches (245 inches as snowfall).
There are three major rivers and many lesser streams
flowing into the estuary. All of these rivers and streams are
glacier fed. The melting glaciers create very high suspended
solids, however, other water quality characteristics of the
rivers and streams are exceptional. For example, dissolved
oxygen measurements were consistently found to be greater
than 95% saturation and chemical oxygen demand values
were generally less than 10 mg/1.
Port Valdez is a positive estuary in that more fresh water
is added through precipitation and the inflow from rivers
and streams than is lost by evaporation. It has an area of
approximately 25 square miles, a maximum depth of 850
feet and a mean depth of 750 feet. Port Valdez is
connected to Prince William Sound by Valdez Arm.
Maximum exchange of water between Port Valdez and
Prince William Sound is limited by a sill 485 feet deep,
extending across the southern portion of the inlet to Port
Valdez. In addition, the deep waters of Prince William
Sound below 575 feet are isolated from the deep waters of
the Gulf of Alaska by the continental shelf.
Nevertheless, studies of the^tructure and circulation of
fiords in Alaska reveal that there is a continuous or at least
frequent renewal of the water within the fiord. Similarly,
information obtained from Port Valdez to date indicates
that frequent renewal of the entire water structure within
the fiord occurs.
An interchange or overturning occurs each spring and
carries the oxygen-rich surface waters to replace the bottom
waters. Thus the fiord contains high concentrations of
dissolved oxygen throughout its depth enabling aerobic
organisms to thrive. During the preliminary studies by the
University of Alaska Institute of Marine Science, the lowest
dissolved oxygen value obtained was found at 650 feet and
was within 78% of saturation. Comparable depths in the
Gulf of Alaska reveal dissolved oxygen levels observed in
Port Valdez are very important when one considers that
theoretically considerable organic loading could be applied
before nuisance conditions would develop. Extreme caution
is necessary, however, because the preliminary studies
available do not allow an accurate estimate of the waste
organic matter than can be safely consumed by aerobic
micro-organisms. In order to more accurately predict this
value many factors such as vertical mixing Tales, rates of
decomposition, tidal action and fresh water flushing need
to be determined.
During the summer months salinity measurements indi-
cate fresh water outflow occurs in the upper 100 feet and
below 100 feet there is a very slow flow of saline water into
the estuary. Below 300 feet fairly uniform conditions exist.
The present data indicate that there is a complete
flushing of the estuary at least once a year. However, it is
emphasized that considerable study needs to be done
before the actual circulation and flushing characteristics of
Port Valdez are completely understood.
Preliminary biological data have been obtained in Port
Valdez and there is noticeably lower productivity within
this system compared to that obtained from Valdez Arm
and other bays within Prince William Sound. The available
data suggest that the physical environment within Port
Valdez is severely limiting and that the few organisms that
do exist are not vital to the present ecology of the area.
There are several important salmon streams, however,
which support large numbers of salmon. These streams will
require protection from the effects of oil spills and other
industrialization. Major attention must be focused on
maintaining salmon productivity in the Port Valdez
vicinity.
LAWS AND REGULATIONS2 •3-4-5
It is important to recognize that there is a vast
complexity of laws and regulations governing the modus
operandi of this plan to remove oil from beneath the frozen
ground on the North Slope of Alaska and ship it south to
market in the "lower 48". The following discussion,
however, will deal with only one set of laws which are
particularly significant when viewed in connection with the
ballast water treatment facility.
The State of Alaska has the responsibility and the right
to prevent and to control water pollution within its
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BALLAST WATER TREATMENT 127
boundaries. This is set forth in the Federal Water Pollution
Control Act of 1956 and although this Act has been
amended many times since original passage, the legislation
defines in clear terms congressional intent to make this
activity a State responsibility.
Toward this end the policy of the State was established
as follows:
"It is the public policy of the State to maintain
reasonable standards of purity of the waters of the State
.consistent with public health and public enjoyment, the
propagation and protection of fish and wildlife, including
birds, mammals and other terrestrial and aquatic life, and
the industrial development of the State, and to require the
use of all known available and reasonable methods to
prevent and control the pollution of the waters of the
State3". The Alaska Department of Health and Welfare is
assigned the jurisdiction to abate and prevent the pollution
of the waters of the State.
The Water Quality Act of 1965 provided that each of
the states must adopt water quality standards for interstate
waters. Thus Alaska revised its existing Water Quality
Standards to meet the approval of the Federal government.
These Water Quality Standards classify the waters of the
State according to use and establish Water Quality Stan-
dards for each of these classifications. Class "A" water has
the highest use classification possible descending in priority
to the lowest possible use classification Class "G". All
coastal waters are Class "D" or Class "E" (the difference
being in Class "E" waters shellfish are present). Port Valdez
is an important fishery area and is therefore a Class "D"
water.
The serious concern of the Alaska Department of Health
and Welfare for protecting the valuable fishery in the
Valdez Area has resulted in one of the most stringent oil
removal requirements in the world. Although State Water
Quality Standards imply a maximum of about 15 parts per
million of oil in the receiving waters (a visible sheen occurs
at about this level) State engineers have required the
Alyeska Pipeline Service Company staff to develop equip-
ment to reduce oil in the effluent from the ballast water
treatment plant to a maximum of 10 parts per million.
Since the 1970 Legislature has enacted a law to provide
that tankers bring all oily ballast ashore for treatment, the
Alyeska Valdez terminal treatment plant will actually be
protecting not only the Valdez Arm, but areas within and
off Prince William Sound where tankers might have been
expected to discharge surplus ballast prior to coming into
port.
Both from the standpoint of adequate laws and regula-
tions and from the standpoint of cooperative effort with
other state and Federal agencies, the Alaska Department of
Health and Welfare has developed a strong program which
exhibits a deep concern for environmental protection.
Through a program of plan review and permit issuance,
the Department exercises jurisdiction over all new industrial
and municipal sources of pollution. Preliminary plans
usually are discussed with staff engineers, final plans and
specifications are reviewed for compliance with our statute
and codes, and the completed project is monitored for
adherence to requirements set forth in a waste discharge
permit.
Prior to the greatly enhanced Federal Oil Pollution
Legislation of 1970, the Alaska Oil Pollution Task Force,
consisting of representatives of State and Federal govern-
ments as well as of industry, provided a mechanism for
development of a contingency plan, a communications
network, and for evaluation of plans for preventing and
controlling oil pollution. Particular stress was placed on the
need for all employees on drill rigs and pipelines to
understand the absolute necessity for preventing the loss of
oil from any system.
As spills are reported anywhere in Alaska today, State
and Federal engineers and biologists investigate promptly to
assure absolute minimum residual effect on the environment.
The industry or agency responsible is advised regarding
clean-up, and the investigating officer may assist in locating
absorbents and equipment for clean-up.
The Alyeska Pipeline Service Company will be required
to show in its plan submitted for Department approval that
adequate stockpiles of clean-up materials will be provided at
the terminal and that its employees have been trained to
make use of these materials as needed.
Ballast Water Treatment Facility
General:
Transferring 2 million barrels per day of Alaskan North
Slope crude oil from land based storage tanks to crude oil
tankers for shipment to refineries located in the "lower 48"
presents problems of great magnitude.
Because of damage that has been sustained to the marine
environment in areas where oil spills have occurred; because
of public clamor and because of increasingly more stringent
Federal and State requirements regarding the disposal of
oily ballast water on the open sea, future policy necessitates
that industry meet its legal and moral obligations to
maximize the utilization of modern, efficient onshore
treatment facilities.
Recognizing these obligations, Alyeska Pipeline Service
Company intends to construct what is perhaps the largest
facility of its kind to accept oily ballast from vessels
entering Port Valdez and reduce the total oil content to a
maximum of 10 mg/1 prior to discharging the effluent into
the waters of Port Valdez.
Three primary considerations served as the basis for the
design:
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128 OIL SPILL PREVENTION...
1. The effluent must meet State and Federal require-
ments;
2. The facilities must be easily operated and economi-
cally suited to local conditions; and
3. The facilities must be expandable to meet long-range
terminal capacity.
Laboratory Examination:
After agreeing with State and Federal water pollution
control officials that their ballast water treatment facility
must produce an effluent containing not more than 10
mg/1 total oil, Alyeska Pipeline Service Company engineers
retained a consultant to associate with an experienced man-
ufacturer to develop the equipment capable of meeting this
requirement. The manufacturer conducted extensive lab-
oratory tests under controlled conditions to determine the
feasibility of the project.
Alaskan North Slope crude oil with a specific gravity of
0.88 and Wilmington crude oil with a specific gravity of
0.92 were used in the tests for comparison or results. The
Alaskan crude was chosen as being representative of typical
problems to be encountered and the heavy Wilmington
crude was chosen to represent extreme conditions to be
expected in separating the oil from the water. Ocean water
obtained from Pudget Sound and artificial sea water were
used to prepare the wastes.
A Waring blender (16,000 rpm) and a centrifugal pump
were used to mix and emulsify the oil and ocean water.
Dissolved-air flotation laboratory equipment was used to
demonstrate the effectiveness of the process.
Total oil content was determined by the procedure
described in Standard Methods for the Examination of
Water and Wastewater, Twelfth edition.
The effects of aging time after emulsification, tempera-
ture, emulsification time, various chemical treatment meth-
ods and chemical treatment and dosages were evaluated in
order to recommend a method of meeting the requirements.
The results of the laboratory studies showed that
dissolved-air flotation with the addition of 25 mg/1 Alum
[Al2(SO4)3l8H2O] and 2 mg/1 of a synthetic cationic
polyelectrolyte coagulant aid would produce the desired
results.
In these tests the Waring blender was used to emulsify
the oil/water mixture for 1 and 2.5 minutes which was
considered to be more severe than the conditions expected
in the actual installation. Flocculation was allowed to occur
for 5 minutes in the laboratory tests and flotation using a
50% cycle rate was used.
Design Considerations:
The southern shore of Port Valdez was selected as the
site for the terminal facilities. This area provided excellent
topography for the oil tanker docking facilities and by
benching the treatment facilities into bedrock some 100
feet above sea level maximum protection was afforded
against tsunamis and earthquake action in this seismically
active region.
Figure 1 illustrates the basic design considerations for
this facility. It should be noted that the operations are
planned for two phase construction. The first phase facility
will have the capacity to accommodate the ballast water
from the simultaneous arrival of 2-250,000 DWT oil tankers
and 1-120,000 DWT oil tanker. It will provide sufficient
volume to store 1.29 million barrels of ballast water. The
future phase will be able to accommodate the simultaneous
arrival of 4-250,000 DWT tankers and 1-120,000 DWT
tanker and have storage capacity for 2.15 million barrels of
oily ballast water.
The ballast water secondary treatment system will
effectively treat 33.6 and 56.0 mgd at maximum flow for
the initial and future phases, respectively. Matching maxi-
mum oil recovery rate of 0.69 mgd and 1.15 mgd will be
accmumulated if required.
Ballast water temperatures are expected to range from
35°F. to 50°F. and the ballast water to be treated is assumed
to contain not more than 2! oil by volume. After primary
treatment, the ballast water is expected to contain 50-80
mg/1 and the final effluent will be required to contain not
more than 10mg/l total oil measured on 24 hour composite
Basis for Ballast Storage Capacity:
Initial: 2-250,000 DWT, 1-120,000 DWT
1.29 million barrels
Future: 4-250,000 DWT, 1-120,000 DWT
2.15 million barrels
Ballast Water Treatment Plant:
Initial: 23,340gpm(33.6 mgd)
Future: 38,900 gpm (56.0 mgd)
Dry Oil Recovery System:
Initial: 480 gpm (0.69 mgd)
Future: 800 gpm (1.15 mgd)
Temperature Ballast Water:
35°F to SOT
Crude Oil Content (Ballast Water):
To storage: 2% by volume
To treatment: 50-80 mg/1
Effluent Oil Content:
10 mg/1 maximum (based upon 24 hour
composite samples)
Figure 1: Design Considerations
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BALLAST WATER TREATMENT 129
Description of Facilities
There are three basic components to the ballast water
treatment system: Primary gravity separation storage tanks,
dissolved-air flotation secondary treatment with the addi-
tion of chemicals for flocculation and an outfall/diffuser
system extending into Port Valdez at least 100 feet deep.
In addition to these components, there will be an
extensive oil recovery system, complete facilities for chemi-
cal storage and addition, a storm drain/treatment system
and incineration facilities. Piping has been arranged to
provide complete versatility throughout the entire system.
Modern laboratory equipment and facilities will be pro-
vided to control and monitor the effectiveness of the
operation.
Oily ballast water from incoming vessels will be pumped
quickly into the onshore primary ballast water treatment
facility. It is anticipated that it will contain 2-3% oil by
volume. The primary system will consist of quiescent aging
in 430,000 barrel capacity storage tanks (250 feet diameter
x 53 feet high) for 6 to 8 hours. The settled ballast water
is expected to have an oil content of 50 to 80 mg/1.
The dissolved-air flotation process has been used exten-
sively to remove oil and suspended matter from water.
Often chemicals are added to the process to enhance
efficiency. The laboratory results showed that chemicals
were necessary to achieve the high degree of treatment
required. Figure 2 provides the design criteria for the
dissolved-air flotation system. These criteria follow closely
those recommended by the American Petroleum Institute's
Manual on Disposal of Refinery Wastes, Volume on Liquid
Wastes 1969, chapters 5,6, 7 and 9.
There are three basic units in the dissolved-air flotation
process:
1. Flocculation,
2. Pressurized aeration and mixing, and
3. Flotation.
The ballast water, including dosages of Alum (25 mg/1)
and polyelectrolyte (2 mg/1) which have been added
upstream, is retained in the flocculating chamber for ten
minutes. During this time, gentle mixing promotes floccula-
tion.
After the flocculation process, the ballast water is mixed
with an air-charged stream consisting of 50% recycled
effluent. As this stream (pressurized to 50 psig) is released
into the flocculated ballast water tiny air bubbles mix with
the ballast water and attach themselves to the flocculated
particles and suspended matter.
The flotation process follows the mixing chamber and
consists of a quiescent chamber which allows tiny air
bubbles to carry the solids and oil to the surface where
mechanical skimmers remove the floating mixture.
After flotation, the treated ballast water flows into a
collection flume, where it will be continuously monitored
for oil content, hence to a 42" diameter outfall pipeline
which extends into Port Valdez terminating at a depth of
more than 100 feet. At this point, there is a diffuser
network designed to promote dilution and mixing of the
treated water with the receiving waters of Port Valdez.
Criteria
Maximum influent flow = 23,340 gpm
Recycle Rate = 50% of influent flow
Rise rate Vt = 0.4 feet per minute
Flocculation detention time =10 minutes
Maximum channel width = 24 feet
Effective channel water depth =12 feet
Features of System (based on criteria)
Channel flow-through area = 288 square feet
Number of channels = 6
Flow through velocity Vh = 2.7 feet per minute
API design factor = 1.39
Channel effective length =112 feet
Flotation detention time = 41.5 minutes
Figure 2; Design Criteria for Floccu'ation-Flotation
Process
The laboratory results showed that it was necessary to
add 25 mg/1 Alum and 2 mg/1 of synthetic cationic
polyelectrolyte to the ballast water for most effective
treatment. An investigation into costs, transportation,
equipment requirements and operation resulted in the
utilization of a total liquid handling system.
The Alum will be diluted to a 6% solution and fed to the
system 30 seconds upstream of the flocculating zone by a
variable speed diaphragm pump. The polyelectrolyte will be
diluted to a 1% solution and added to the system by a
variable speed pump immediately following the Alum.
All pumping and storage systems are environmentally
controlled to ensure longtime trouble free operation.
The free oil removed from the ballast water during the
primary gravity separation phase is to be transferred to
skimmer tanks for additional gravity separation, hence to
oil heater treaters which produce an oil effluent having less
than 1 % water content. This recovered oil is transferred to
the terminal storage for ultimate shipping. The water
-------
/ / ft'1 > '' ( r
//: ti/^ \ •-
#y/// 3
.
Figure 3: Ballast Water Treating General Flow Diagram, Drawing No. D-50-M408-0 (Reproduced with
permission from Alyeska Pipeline Service Company).
-------
PORT VALDEZ CRUDE OIL STORA6E
Figure 4; Ballast Water Treating General Plot Plan, Drawing No. D-50-L401-0. (Reproduced with
permission from Alyeska Pipeline Service Company).
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132 OIL SPILL PREVENTION
removed from this process is returned to the primary
gravity separation tanks.
Incineration is planned to dispose of sludge deposits
which accumulate in the ballast water storage tanks and
other components of the separation process. This incinera-
tor will meet Federal emission standards.
SUMMARY
The ballast water treatment facility proposed for Port
Valdez will play an important role in the eventual elimina-
tion of oily ballast water at sea which has caused
unnecessary damage to the marine environment in the past.
This facility will be modern, expensive and efficient. In
fact, the standard of 10 mg/1 maximum oil content in the
effluent of the treated ballast water imposed upon the
Alyeska Pipeline Service Company by the State and Federal
regulatory agencies is perhaps the most stringent ever
required for a similar project.
It is proposed to quickly accept the oily ballast water
from incoming oil tankers into huge primary gravity
separation tanks. The waste water will then enter a
dissolved-air flotation system and with assistance of chemi-
cal additives the desired effluent is to be obtained.
Recovered oil will be transferred to the oil storage tanks for
shipment south. All waste sludges will be incinerated. The
facility is to be designed for versatility and backup units
will provide maximum reliability of operation. The facility
will be designed to accept all wastes and treat them on site
to meet all State statutes and regulations relative to
pollution of the land, air, and water.
Port Valdez is a typical estuary, deep, high in dissolved
oxygen content and continuously active. This is very
important when considering that the effluent from a highly
treated ballast water treatment facility will be discharged
into it. The effect of this effluent upon the marine life can
be expected to be minimal.
Of primary concern must be the protection of a very
important salmon fishery resource in Port Valdez. Biologi-
cal productivity has not been found to be diverse in Port
Valdez and no particular species except the salmon are vital
to the overall ecology in the estuary. This is not the case in
Valdez Arm or Prince William Sound, however. In these
areas, massive oil spills, if they occur have the potential to
inflict serious environmental insult upon the prolific
growths of plant and animal species in these highly produc-
tive and diverse waters. The potential for disastrous oil
spills from huge oil tankers traveling in the Prince William
Sound area demands that extensive, failsafe vessel move-
ment patterns and contingency plans be instituted to
eliminate this possibility from occurring for all practical
purposes.
In the opinion of this author, the Alyeska Pipeline
Service Company is committed to producing an excep-
tionally high quality ballast water effluent and has more
than met the challenge.
REFERENCES
1. Hood, D.W., 1969. Baseline Data Survey for Valdez
Pipeline Terminal Environmental Data Study, Report No.
R69-17, Institute of Marine Science, University of Alaska,
College, Alaska 99701.
2. Laws of the United States relating to Water Pollution
Control and Environmental Quality compiled by the
Committee on Public Works, U.S. House of Representa-
tives, Superintendent of Documents, U.S. Government
Printing Office, Washington, D.C. 20402.
3. Alaska Statutes, Title 46. Water, section 46.05.
4. Alaska Administrative Code, Title 7. Health and
Welfare, Chapter 70. Water Quality Standards.
5. Statement of Commissioner Frederick McGinnis,
Department of Health and Welfare, State of Alaska, at the
Department of Interior Hearing, February 24, 1971,
Anchorage, Alaska.
6. Incon, Inc., Engineers & Constructors, Houston,
Texas, Engineering Design Report, Ballast Water Treating
Facilities Trans Alaska Pipeline System Port Valdez Alaska
Terminal, July 1970.
1. American Petroleum Institute, Manual on Disposal of
Refinery, Wastes, Volume on Liquid Wastes, First edition
1969. (Priority)
8. Aqueous Wastes From Petroleum and Petrochemical
Plants, Milton R. Beychok, 1967.
-------
OIL SPILLED WITH ICE: SOME
QUALITATIVE ASPECTS
F.G. Barber
Marine Sciences Branch, Ottawa
ABSTRACT
The note gives an indication of the ways in which con-
tainment by an ice cover of spilled oil can occur and of
some of the ways in which the containment may be utilized
in cleanup. There is in the experience the implication that
certain characteristics of an ice cover may be usefully sim-
ulated in a man-made structure.
If spilled oil is to be removed from a water surface, i.e.,
picked up or burned, it must first be contained. If this is
not achieved by a shore and by the material on a shore, e.g.,
by debris, weed or ice, then it is frequently not possible to
provide containment by the deployment of man-made
structures. In the following it will be suggested that an ice
cover can limit oil movement at the surface almost as well
as a shore and that perhaps certain features of an ice cover
. could be incorporated into the techniques of boom con-
struction and deployment. It is emphasized that the experi-
ence is largely qualitative, so that while a clear indication of
processes is not possible, several are suggested. Of course an
operational association with oil spills usually does not
provide adequate opportunity to obtain anything but quali-
tative data; however, it is believed that the considerations
described here could be examined through experiment,
perhaps of the type described by Vance 1.
The general conclusion about the effectiveness of an
ice cover was derived in part from an experience on the east
coast of Canada in late winter2 and from two in summer in
the Canadian Arctic3-4. In each, the containment by the ice
was such as to limit the extent of shoreline eventually con-
taminated and in one, the containment allowed time for the
consideration of a number of recovery and cleanup meth-
ods which included pumping on to the sea ice to facilitate
evaporation. It is clear, however, that we are not yet able to
exploit containment on every occasion it might occur. As
ice can provide unusually effective containment, methods
of such exploitation in the arctic and other ice covered
waters might be pursued. This would include the considera-
tion that the containment by ice can occur for oil on a
water surface, on the ice surface, and perhaps under the ice
surface, and within the structure of the ice.
Particular Oil in Ice ,
Bunker C from the tanker ARROW aground in Cheda-
bucto Bay was found as particles within the structure of the
ice (Figure la); a form of oil which was very reminiscent of
the oil seen in seawater samples obtained there at depth.5
Apparently, the oil particles were at the surface and became
contained in the ice during the process of freezing. Later,
when ice was melting it was possible to discern areas of
"dirty" ice, at least 50 feet in diameter, within which were
near-surface accumulations of oil 2-6 inches in diameter
(Figure Ib). At this time I was able to view samples of the
ice and oil and I considered that the pattern resulted from a
redistribution of the particulate oil due to internal move-
ment with melt water (the ice cover was 4" thick and had
been 8" thick), but this is not at all certain. Neither is it
certain by what process the oil particles were formed.
Forrester5 suggested that wave action on oil at the water
surface and on oil ashore could lead to the formation of
particles; Wicks6 has shown that "showers of droplets" can
occur at the head wave region of oil containment. It seems
likely that both processes occurred at Chedabucto.
Oil on the Water Surface with Ice
In particular, large accumulations of oil were contained
across ice barriers there (Figure 1 c) which could have led to
the oil droplets of Wicks and hence the particles. Oil had
become incorporated into the ice sheet during growth and
ice can be seen mixed into the accumulations of oil at the
leading edge. Although an entirely adequate survey method
was not developed, we did attempt to determine the
amount of oil contained. On some occasions the oil was
judged to be 2-4 inches thick, but generally it appeared to
be less than an inch. At the time there was no way by
which we could pick up the Bunker C so contained; neither
did we learn how to burn it. Even now I am not certain
133
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134 OIL SPILLED WITH ICE . .
Figure 1- Four photos, the last three from a helicopter on
March 21 1970 of oil and ice in Chedabucto Bay2, (a) Oil in
paniculate form in a sample of ice from the relatively new ice cover
in Lennox Passage on February 28. View is of a vertical section; the
eraser end of the pencil is at the under-side of the ice. (b) The i<
how best this containment might have been exploited, al-
though pickup machinery of the type developed by Sewell
would likely have been effective.
Containment by ice occurred at Resolute, N.W.T.
(about 75° N latitude) in August, 1970 when a spill4 oc-
curred into the harbour where an 8-9 tenths ice cover
existed. The spill was relatively small, perhaps 3000 gallons,
surface toward the eastern edge of the ice cover in Lennox Passage.
(c) View to the north of Haddock Harbour, (d) View of Janvnn
Lagoon in which the last of the ice and oil there and the boom at
the entrance may be seen.
and was of a relatively light fuel oil, heavier than diesel but
much lighter? than a Bunker C type. For about six days
after the spill occurred, the ice containing the oil was c<
fined to the head of the harbour by the southerly wind^
Subsequently the wind changed to the north and movec
much of the ice and oil out of the harbour, although by this
time a portion of the shore had been oiled (Figure 2).
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OIL SPILL PREVENTION 135
Figure 2: Ice grounded on a relatively heavily-oiled portion of
the intcrtidal /one at Resolute.
Unforlunately, we were not able to observe the situation
prior to this major movement, so that it is not clear
whether either pumping or burning would have been clean-
up options, although I lend to believe they would have
been, particularly early in the spill. For example, the oil
might have been pumped inlo containers ashore or into a
ship, or to other areas of containment by sea ice and
burned in discrete amounts.
Oil on Sea Ice
These considerations were based on experience gained
in June, 1970 at Deception Bay in western Hudson Strait in
an association with cleanup of a spill from a tank farm
(Figure 3a) of about 400,000 gallons of diesel fuel and
some gasoline.3 The spill from the farm occurred during a
time of small tide at a location where the tidal range varied
from about 1 2 to 19 feet and where the sea was completely
covered with ice over four feet thick. Most of the oil was
contained within the large blocks of ice, 4-7 feet thick, on
the intertidal zone in front of the slide (Figure 3b) and
nearby on the surface of the water in pools along the tidal
hinge. As the tidal range increased to a maximum (on June
22), oil moved out of the area of containment in the inter-
tidal /.one of the slide onto these pools; however, a con-
siderable quantity of oil remained and this was eventually
cleaned up by burning. The burn (Figure 3c) was initiated
at low water al the time of maximum tidal range. It fol-
lowed a general cleanup of the site during the previous
week. The cleanups was initiated by pumping onto the sea
ice surface where it was eventually burned. The com-
bination proved an appropriate method of cleanup although
the burning caused some air pollution and some biological
damage resulted8.
The significant aspects of the incident are that the ice
cover provided effective control of the spill over a period of
two to three weeks and furnished an effective platform
from which to work. It also provided a unique type of
containment, i.e.,on the ice surface, as a secondary step in
cleanup. The considerations which led to pumping the oil
Rgurc 3: The tank farm at Deception Bay, Quebec after the
slide of early June, 1970. (a) The six tanks in the farm; that tank on
the far right was reported to have been nearly empty, (b) Area
about the lank on the intertidal zone after cleanup. Note that the
burn has "opened up" the ice of the intertidal zone in front of the
slide, (c) The start of the burn within the intertidal zone of the
slide.
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136
OIL SPILLED WITH ICE...
onto the sea ice included the observation that evaporation
was occurring and that, as the exposure and surface area
would be very much increased, the rate and quantity
evaporated would increase. I concluded that this would
have been an effective method of cleanup of that oil on the
ice surface. However, there were other considerations, in-
cluding the imminent breakup of the ice cover and the
requirement to burn at least part of the oil, i.e.,that portion
mentioned above which remained in the intertidal zone of
the slide area out of reach of the pumps. Therefore, it was
decided to effect an immediate cleanup by burning.
Oil under Ice Cover
It was a tentative conclusion that, away from inter-
tidal zones and lagoons, oil did not accumulate under an ice
cover, at least not under the uniformly flat ice without
ridges which was generally experienced. It was also con-
cluded that unoiled shores downwind of an area of contain-
ment remained free of oil. The initial consideration was
that the ice cover was simply serving as a very effective
"boom." Subsequently, it seemed that oil may be trans-
ported under an ice cover, but in particulate form within
the water column, and hence not generally available to oil a
shore.
On the other hand, many of the small lagoons around
Chedabucto Bay became ice covered and a number con-
tained oil. The topography of some lagoons was such that
they were relatively strongly coupled to the sea outside.
Nevertheless,most of the oil in them remained as long as the
ice cover remained, i.e., the ice and oil were generally dis-
persed from the lagoon at the same time (Figure Id). In
certain other lagoons (containing oil) with little coupling to
the sea, the oil did not move about under the ice cover, i.e.,
it was generally observed in the same location and pattern.
Subsequently, the ice cover was dispersed by melting and
the oil was then moved about by the wind to oil the in-
ternal shores of the lagoon.
To some extent this experience might have been antici-
pated. The ice cover removes the influence of wind and the
Bunker C fuel oil should have little tendency to spread at
water temperatures near freezing10, especially if it con-
tained water2. As well, and with regard to-the lagoon ex-
perience generally, it was not known to what extent the oil
was trapped between layers of ice there, except that in
some places it was2-
That ice can provide very effecitve containment is
evident. It is also evident that containment cannot always
be exploited in recovery or cleanup as some fule oil, Bunker
C for example, can be difficult to pump or burn. There is
some evidence that both these difficulties may be overcome
so that given containment it should be possible to clean up
any spilled fuel oil. On the other hand, there has yet to be
an adequate solution to the problem of containment
generally JO, at least in areas without an ice cover, so that
provision of containment has continued to be the central
problem of cleanup. The experience with ice cover and the
general conclusion concerning the effectiveness of an ice
cover carried with it the implication that certain features of
an ice cover might be arranged for in a man-made structure.
It was realized that an ice cover achieved significant
containment of oil on the water surface even though the
cover could be relatively shallow. It was also realized that
most failures of booms were due to "over-topping"! 1. The
failure does not occur with an ice cover mainly because of
the greater expanse relative to an ordinary boom, but also
because the leading edge of the ice barrier generally
contains broken ice which reduces the sea state, or "chop",
and hence, over-topping. Subsequently, oil becomes
contained and further reduces the chop. The critical feature
here is that an ice cover achieves a separation between the
line along which containment is achieved and the line along
which the wave energy acts. In most ordinary booms the
two coincide.
There are a number of ways by which the separation
might be achieved including the use of an air bubble barrier
to reduce the wind waves or by the addition of material to
simulate a field of broken ice. Were either of these measures
effective it might then be possible to look to a redesign of
the main barrier within the concept of a horizontal, rather
than vertical, array and so achieve a containment approach-
ing that of an ice cover. It is conceivable that such an array
would be inherently stable and flexible.
-------
OIL SPILL PREVENTION 137
REFERENCES
1. Vance, George P. 1971. Control of Arctic oil spills.
Ocean Industry. January: 14-17.
2. In "Task Force Operation Oil (Cleanup of the ARROW
oil spill in Chedabucto Bay". Volumes 2 and 3. Canada
Ministry of Transport. 1970.
3. Barber, F.G. 1970. Oil spills in ice: some cleanup
options.
4. Barber, F.G. 1971. An oiled Arctic shore. Arctic (in
press).
5. Forrester, WX). 1970. Oil particle surveys. Presented at
Fifteenth General Assembly IAPSO Tokyo.
6. Wicks, Moye, 1969. Fluid dynamics of floating oil con-
tainment by mechanical barriers in the presence of water
currents. In Proceedings Joint Conference on Prevention
and Control of Oil Spills: 55-106.
7. Dr. A.Y. McLean, Nova Scotia Technical College,
Halifax. Personal communication.
8. Grainger, E.H. and J.W. Wacasey. MS 1970. Report on a
visit to Deception Bay to examine the biological effects of
the oil spill of early June, 1970. Fisheries Research Board,
Canada.
9. Walkup, P.C., L.M. Polentz, J.D. Smith and P.L. Peter-
son. 1969. Study of equipment and methods for removing
oil from harbour waters. In Proceedings Joint Conference
on Prevention and Control of Oil Spills: 237-248.
10. Anonymous. 1971. Booms and bubble barriers. Marine
Pollution Bulletin. 2(1): 1-16.
11. Lehr, W.E. and J.O. Scherer. 1969. Design requirements
for booms. In Proceedings Joint Conference on Prevention
and Control of Oil Spills: 107-128.
-------
PUGET SOUND FISHERIES AND OIL
POLLUTION - A Status Report
Robert C. Clark, Jr. and John S. Finley
Biological Laboratory
National Marine Fisheries Service
Seattle, Washington 98102
ABSTRACT
The Greater Puget Sound Basin is one of the largest oil
handling areas on the West Coast of North America. Due to
the increased local need for petroleum products and to the
proposed influx of Alaskan North Slope crude oil in the
near future, this area will undoubtedly experience even
greater petroleum transportation and processing activities.
In terms of living resources of economic value-fish, shell-
fish, waterfowl and aquatic animals-Puget Sound is one of
the most productive estuaries on the Pacific Coast. There is
increasing evidence that the extensive sport, commercial
and aquacultural fisheries resources are threatened by pol-
lution resulting from oil spilled in the transport, handling,
and use of petroleum.
This paper presents a stauts report of what is being
done in the Pacific Northwest by the petroleum industry,
state government and federal agencies to protect the en-
vironment prior to the anticipated expansion of the petro-
leum industry. Research activities which will provide addi-
tional information for minimizing the impact of oil pollu-
tion on an already pollution-stressed environment are also
discussed.
The Greater Puget Sound Basin has all the natural re-
sources necessary to make it one of the most productive
estuaries in all of North America. This basin is that portion
of the Pacific Northwest containing all the inside waters
from Cape Flattery to north of Vancouver, British
Columbia. See Figure 1. With a shoreline equal in length to
the entire coastline of Washington, Oregon and California
and a surface area of 2,500 square miles, the Washington
State portion of the basin has the advantage of providing
protected deep water ports as well as a natural setting for
marine aquaculture. Today this area is becoming one of the
major oil handling centers on the West Coast of the United
States. Can the area meet the challenge of protecting its
natural environment while permitting an orderly develop-
ment of the petroleum industry?
Existing Fisheries and the Potential for
Aquaculture - The Renewable Resource
Deforestation, flood control, hydroelectric dams, in-
dustrial and municipal pollution have severely depleted
many of the nursery areas for Puget Sound fisheries. Fur-
ther urbanization and industrialization threaten their com-
plete destruction. Since it is unlikely that this process will
be reversed, it is becoming apparent that conventional fish-
ing methods will have to be supplemented by aquacultural
technology to maintain fishery hields at satisfactory levels.
Today the rich and productive waters of Puget Sound
directly support a commercial and sport fisheries valued at
75 to 85 million dollars annually. Two-thirds of this value
is derived from sport fishing. Intensive aquacultural acti-
vities, developed over the next decade or two, could add an
additional 100 million dollars annually. During the same
period of time, the volume of petroleum and its products
moved over Puget Sound waters could also increase as much
as ten times if the trans-Alaska and trans-U.S. pipelines are
built. Properly developed and managed, aquaculture and
the petroleum industry should be able to exist side by side
in the estuaries. While it would be difficult for properly
planned aquaculture to exclude the petroleum industry, the
oil pollution caused by a single large accident inside Puget
Sound could destroy the area's entire aquaculture industry.
Aquaculture is just beginning to emerge as an industry
in Puget Sound. One of the most ambitious projects is being
developed by the Lummi Indians on land situated between
two major oil refinery complexes in north Puget Sound:
Cherry Point-Ferndale a few miles to the north and Ana-
cortes to the south. The Lummi Indians have an investment
worth four million dollars in four aquacultural activities:
139
-------
140 OIL SPILL PREVENTION
Voncouver Island
1*1 if u M vnvmtcuk
*t FERNDALE*
BEJ.LINGHAM<^
i I J I ' ' ^ ^^ *
(Kw^ANACORTES
V- U Im \ =
Whidbey
Island
PORT ANGELES
Union
(Standby) .if
Olympic Peninsu la
Refineries
Crude Oil Pipelines
mini Product Pipeline
Figure 1: The Greater Puget Sound Basin
-------
PUGET SOUND 141
(I) an oyster-spawning hatchery, which is being used to
establish and perpetuate their stocks of seed oysters-an ex-
cess of which they plan to sell to other Puget Sound oyster
growers who are now dependent upon imported Japanese
seed oysters; (2) a series of diked ponds on the tide-flats for
rearing salmon, trout and rafted oysters; (3) a commercial
algae-harvesting operation which provides raw materials for
East Coast reduction plants; and (4) a bait worm industry
in the intertidal zone.
At Manchester, Washington, Ocean Systems Inc. has
undertaken a pilot salmon rearing project based on
salt-water rearing methods developed by the National
Marine Fisheries Service. Salmon are grown from eggs to
marketable fishes of 3/4 pound in one year. In Europe and
Japan mussels, clams and shrimp have proved amenable to
rearing under controlled conditions.
The Petroleum Industry —
The Unintentional Competitor
While aquaculture may represent the future for Puget
Sound, the present demands more than 400,000 barrels
each day (b/d - 42 U.S. gallons per barrel) of refined petro-
leum products to keep the factories, furnaces and motor
vehicles fueled in the coastal portions of Washington,
Oregon and British Columbia. The refining capacity of the
area is considerably less than the demand; so additional oil
is supplied by tanker from California. The demand for
petroleum products is expected to increase by approxi-
mately 4.5% annually for the western United States, and
the petroleum industry has started to build additional re-
fining facilities locally. There are already four refineries
near Vancouver, one at Ferndale, two at Anacortes, and two
small refineries in Tacoma.
A new Atlantic-Richfield Company (ARCO) refinery is
nearing completion at Cherry Point, and though it will in-
crease the area's production by 26%, it will still not meet
local demands. Standard Oil Company of California has a
large block of land adjacent to the ARCO refinery site and
Union Oil Company of California has actively sought a
Puget Sound refinery site in the past.
Additional local refineries will have to be built if the
present inflow of refined products from California is to be
reduced. The Trans Mountain Pipeline supplies low-sulfur
crude oil from Alberta and British Columbia oil fileds to
the existing refineries in Vancouver, Ferndale and Ana-
cortes. This supply of pipeline-delivered crude oil is essen-
tially limited to these refineries which are producing near
their design capacity now. Therefore, any new refinery will
probably be dependent on crude oil supplied by tanker.
ARCO will require up to 100,000 b/d, and each additional
facility will only add to this amount resulting in an abrupt
jump from 17,000 to several hundred thousand barrels of
crude oil shipped into Puget Sound daily.
When the Trans-Alaska Pipeline boosts its pumping rate
to the projected 2,000,000 b/d, the amount of crude oil
awflable at the Valdez terminal will exceed 'the western
united States petroleum requirements. The demands for
petroleum products are becoming critical in the Midwest
and East Coast, especially for low-sulfur crude oil such as
that from Alaska's North Slope. One plan under active con-
sideration is to transport North Slope crude oil through the
Trans-Alaska Pipeline, load it aboard supertankers at
Valdez, ship it to a Puget Sound terminal of a trans-U.S.
pipeline and then pump it to eastern markets. A feasibility
study has been undertaken by ARCO, British Petroleum,
Humble, Marathon and Mobil for this 2,600-mile, big-inch
pipeline. Depending on the size of such a trans-U.S. pipe-
line, up to 1,000,000 b/d of North Slope crude oil have
been predicted to enter Puget Sound.
The transportation of refined products in western
Washington and Oregon is by products pipeline (26%),
tanker and barge (69%) and tank and railcar (5%). On the
average, one finds approximately 28,000 barrels of crude
oil and nearly 220,000 barrels of refined products being
transported daily on waters of the Greater Puget Sound
Basin. Nearly 45 tankers (usually 15,000-30,000 dwt ves-
sels) call each month in Puget Sound ports to bring in crude
oil or products and to ship out locally-produced products,
and a small amount of crude oil.
, The mammoth tanker has become the most economical
and feasible method for the transportation of bulk
petroleum on a worldwide basis. Unless exception is made
to the Jones Act requiring U.S. built and manned vessels on
domestic runs, the crude oil shipments from Valdez to local
refineries will be in U.S. tankers. Figures on United States
and world tanker construction are presented in Table 1.
The conclusion that can be drawn from these facts and
figures is that more and more petroleum will be moving in
Puget Sound - and in larger and larger vessels.
Oil Spills - Examples of the
Potential Danger
Four principal reasons have been given for pollution in
oil ports: design faults, mechanical failures, spillage during
loading and unloading, and human error. Of these, the last
is the most important cause of oil pollution and the most
difficult one to correct. The majority of the large accidents
in recent years has been attributed to human error or poor
judgment. No oil port is able to avoid spillage. Severe
measures have been taken to prevent or control oil pollu-
tion in Milford Haven, a large and modern British oil port
adjacent to a National Park. There, 210 million barrels of
oil were handled in 1966; of this, 21,000 barrels were spil-
led in port. Thus, in spite of modern technology and in
spite of the declared intention to minimize pollution,
0.01% of the oil entering this port was spilled. Other oil
ports may have less favorable records, and a single large
catastrophe in port could increase this spillage rate drama-
tically. It would appear that oil spills and discharges are
inevitable in oil ports and refinery complexes. Assuming
that the loss in port can be limited to the exceptionally low
level of 0.01%, the average spillage from a 1 million b/d
shipping activity would be on the order of 100 barrels per
day.
-------
142 OIL SPILL PREVENTION ...
TABLE 1
UNITED STATES AND WORLD TANKER CONSTRUCTION
Company
ARCO
Overseas
Shipbullingh
Mobil Oil Corp.
Number
1
2
2
1
1
1
Deadweight
tons
120,000
120,000
69,800
62,000
120,000
126,000
Completion Yard/Notes
1973 Bethlehem Steel Corp.
1 974 Sparrows Point, Md.
1971
1970
1973
1972 Sun Shipbuilding &
Standard Oil (Calif)
Seatrain Lines
World Fleet
World Fleet
World Fleet
Largest Vessel
DDCo.
2 69,800 1972 Bethlehem Steel Corp.
1 230,000 1972 Seatrain Shipbuilding
1 230,000 1973 Brooklyn, N.Y.
21 200,000-plus 1969 As of June
94 200,000-plus 1970 As of June 30
168 150,000-plus 1973 On order as of Nov. 1970
2 477,000 1973 On Order in Japan
Oil pollution in Puget Sound has appeared to increase
slightly over the last four years as shipping and industriali-
zation have also increased. This may either be a real in-
crease or an apparent increase based on greater public
awareness and reporting of oil spills-or a combination of
both factors. A primary source of oil spill data has been the
U.S. Coast Guard. Over the last four years there haveljeen
over 200 Coast Guard investigations of oil spills in the
Pacific Northwest, exclusive of British Columbia waters.
The location of the polluting source, probabe cause, and
severity of these reported oil spills are given in Table 2.
Usually a loss of more than ten barrels is considered a major
spill in this area, although in a confined space as little as
two barrels can represent a major problem (bunker oil on a
swimming beach, in a yacht harbor, or in a sewage treat-
ment plant). The striking fact is that Puget Sound has a
higher percentage of major spills compared with other
Pacific Northwest ports (Portland, Lower Columbia River,
Coos Bay and coastal).
At the present time very little oil pollution is obvious
at the existing major Puget Sound refineries. Accidents do
occasionally occur during loading and unloading operations,
but they are generally cleaned up quickly by refinery opera-
tors. There are few subsurface sources of oil in this area; so
existing oil pollution problems come either from ships or
shore. The U.S. Army Corps of Engineers estimated that
40% of the 2,000 spills in UJ5. waters in 1966 were from
land-based sources. In addition to the known sources of oil
pollution, there are serious contributions from the dis-
charge of fuels and spent lubricants in untreated municipal
and industrial wastes and from the incomplete combustion
of marine fuels.
The Washington State Department of Ecology has also
kept a detailed file of the total number of oil and hazardous
materials spills that have been reported from all sources. In
1970 there were 234 spills reported within the waters of
the State of Washington, of which 218 were in Puget Sound
waters or tributaries. See Table 2. The large "unknown"
values reflect the inability of the State and the Coast
Guard to completely investigate every spill because of a
lack of funds, equipment and personnel. The majority of
the reports were from private citizens, not from official
monitoring or surveillance activities.
Regulatory Actions by the State of
Washington - A Potential Deterrent
To combat the dangers of oil pollution in Puget Sound,
the State of Washington has enacted one of the strongest oil
spill laws in the country leaving the oil companies, oil car-
riers and users with unlimited liability for cleaning up oil
spills as well as paying for damages to persons, property or
wildlife regardless of whether the cause was accidental or an
"act of God." In addition to being liable for cleanup and
damage costs, a person who intentionally or negligently per-
mits oil pollution can be subjected to fines up to $20,000.
Thjs law, passed during a special legislative session in 1970,
also sets up rapid review and court procedures for appeals
and allows the state water pollution control agency to
apply standards on effluents going into all waters of the
state. The State of Washington is also considering the estab-
lishment of an oil spill cleanup fund to complement the
unlimited liability law.
The State of Maine has a nonlapsing revolving fund of
$4,000,000 based on annual licence fees of 1/2 cent per
barrel of oil, petroleum products or their by-products trans-
ferred within the state. When the fund reaches the estab-
lished limit, the fees are reduced proportionately to cover
only administrative expenses and sums allocated to research
(maximum of $100,000 per year) and development. This
concept has been suggested for Washington. Another pro-
posal includes the establishing of a fee of 1/100 cent per
barrel on refinery production until a 4 million dollar fund is
reached. Such a fund would permit the state to move im-
mediately through the Department of Ecology to cleanup a
spill and then assess the offender. It would also permit the
State to clean up spills of unknown origin.
-------
PUGET SOUND 143
The Department of Ecology, established in July of
1970, is responsible for enforcing the State's water quality
standards and monitors its water resources. The Depart-
ment has also developed contingency plan capabilities for
responding to major oil pollution accidents in state waters
and have aggressively pursued their responsibilities.
The possibility of Puget Sound oil and gas exploration
in the near future has been reduced due to public pressure
and official decisions. The Washington State Public Lands
Commissioner in November 1970 denied 95 marine oil and
gas lease applications for 140,000 acres of Puget Sound
water bottoms on the grounds that the present
state-of-the-art in petroleu drilling technology could not as-
sure a 100% pollution-free environment. The State consi-
dered such drilling as being incompatable with a potential
multi-million dollar a year seafood cultivation industry in
portions of the 2 million acres of water bottoms under
State control. The Canadian Department of Fisheries and
Forestry denied Standard Oil Company of California
seismic drilling permits at the entrance of the Strait of Juan
de Fuca off the west coast of Vancouver Island in January
1971.
Research Activities-The Search
for an Equitable Solution
One of the limiting factors in developing reasonable
procedures for handling large quantities of petroleum in the
Greater Puget Sound Basin is insufficent knowledge of how
oil pollution damages the marine environment. Large-scale
and long-term studies in the past have usually dealt with
major tanker disasters after the accident occurred (such as
the Torrey Canyon, Tampico, Ocean Eagle, Arrow and the
West Falmouth barge spill). What is needed is research into
the problem of biological damage to local major ecological
zones: to determine the background distribution patterns
and the amounts of natural and man-introduced pollutants
in the environment; to establish through laboratory and
field experiments and bioassays, what effects might be ex-
pected if a pollutant escapes into the local environment;
and to describe and catalog the local marine flora and fauna
by ecological zone and by seasonal distribution.
Preliminary research has been initiated in the Greater
Puget Sound Basin by federal, state, educational and in-
dustry groups. At the Federal level, the Environmental Pro-
tection Agency (EPA) has contracted with Texas Instru-
ments of Dallas to investigate oil and hazardous materials
spills in the inland navigable waters, coastal and estuarine
zones of Washington, Oregon and Alaska. Texas Instru-
ments would start their study immediately after a major
accident to collect and evaluate meteorological and oceano-
graphic data, biological and ecological information, chemi-
cal and physical characteristics of the spill material, as well
as to monitor the pollutant movement or dispersion.
Western Washington State College at Bellingham received a
$16,227 research grant in 1969 from the Federal Water
^Pollution Control Administration to study the effects of
pollutants from an aluminum plant and an oil refinery on
marine plants. Battelle-Northwest at Richland received a
grant last year from the Federal Water Quality Administra-
tion for the development of a hydraulic skimmer capable of
recovering 50,000 gallons of oil per hour from an oil spill.
The Office of Sea Grant within the National Oceanic
and Atmospheric Administration (NOAA) provides research
funding to the University of Washington (and Oregon State
University) to promote long-term, ecological baseline data
acquisition and research activities. The University of Wash-
ington has instituted multi-discipline ocean engineering
systems design courses for students interested in working
on oil spillage problems in Puget Sound.
The National Marine Fisheries Service (NOAA) has a
research unit at the Seattle Biological Laboratory studying
the biological effect of oil pollution on Puget Sound marine
organisms by determining the existing background content
and distribution of saturated hydrocarbons and by observ-
ing short-term, sublethal physiological changes and chemi-
cal uptake of pollutant hydrocarbons under laboratory
bioassay conditions.
The Coast Guard has developed regional contingency
plans for the Seattle Coastal area, and NOAA is developing
plans for combining the scientific capabilities of its various
component Services (National Weather Service, National
Ocean Survey, Environmental Data Service, Environmental
Research Laboratories, Office of Sea Grant and the Na-
tional Marine Fisheries Service) into a coordinated disaster
response team to interface with the Coast Guard and State
contingency plans.
The Washington State Department of Fisheries, in
conjunction with the former Water Pollution Control
Commission, has conducted research in the area of relative
toxicity of various oil dispersants on oyster larvae,
steelhead and coho fingerlings, and has determinad the
dispersing efficiencies of the materials under local
conditions.
The petroleum industry has also been sponsoring re-
search in oil pollution effects. Esso Research and Engineer-
ing Company has awarded a 5380,000 contract to Bat-
telle-Northwest to study the long-term fate of oil in the sea
and its long-term effects on marine life. This study, the
major part of which is being conducted at the Marine Re-
search Laboratory at Sequim Bay, Washington, is develop-
ing tests to assess the immediate toxicity of crude oils, oil
and dispersant, and dispersants singly on a wide variety of
local marine organisms. Balanced eco-community bioassays
are contemplated as well as research into sublethal effects
and synergistic effects. The ultimate goal is to predict the
level at which these pollutants cause short-term acute and
long-term sublethal effects on the local organisms.
In addition to funding research, the local petroleum
industry, through the Seattle office of the Western Oil and
Gas Association, has established a cooperative cleanup pro-
gram and mutual self-help plan for Southern, Central and
Northern Puget Sound.
Even private citizens have become involved. One indi-
vidual has patented an air-dropped inflatable flotation oil
-------
144 OIL SPILL PREVENTION ...
spill control system utilizing a boom which could be
attached to a ship's hull by electromagnets or by vinyl
H-beam connectors to corral the spill oil.
Other industries in Puget Sound are more or less direct-
ly involved in oil pollution matters. To reduce the number
of possible tanker collisions and groundings, Honeywell,
Inc., through their Seattle Marine Systems Center, has
developed a "Proposed Automated Marine Traffic Advisory
System for Puget Sound" using a computerized radar con-
trol concept. Another Seattle firm, Stanley Associates, has
proposed the development of a private "fire brigade"
organization to stockpile needed oil spill cleanup equip-
ment (boats, skimmers, booms, absorbents, etc.) at strategic
points in Puget Sound from which they could direct the use
of such equipment in emergency and salvage operations.
This service would supplement the local oil industry con-
tingency plan and could be financed by the industry on an
annual maintenance fee plus additional charges for cleanup
after an accident.
The Canadian Department of Energy, Mines and Re-
sources (the Marine Sciences Branch which is now in the
new Department of the Environment) has formed an oil
pollution research program to study the long-term fate of
petroleum in sea water and sediments. This research, to be
conducted at the Fisheries Research Board of Canada's
Nanaimo Biological Station and at the Pacific Environment
Institute in Vancouver, will provide complementary infor-
mation from the Canadian portion of the Greater Puget
Sound Basin. The Marine Services of the Canadian Depart-
ent of Transport has developed a contingency response
capability for British Columbia oil spills.
CONCLUSIONS
Unlike oil and gas, food from the sea is a renewable
resource that can be utilized only as long as the water
quality allows the fish and plant life to enjoy maximum
growth. Unfortunately, the greater the amount of petro-
leum handled, the greater the risk for hydrocarbon pollu-
tion of the marine environment. The best procedure for
combatting oil spills in view of the damage to natural re-
sources and recreational facilities is to prevent them from
happening in the first place. By starting now it may still be
possible to restrict the potential damage of the Puget Sound
environment from oil pollution by promoting research into
the specific effects of these pollutants on the local marine
environment with the results being used to continually up-
date cleanup procedures and regulatory actions.
If modern pollution control technology is introduced
and practical pollution control regulations are enforced, it
would theoretically be possible to reduce the amount of oil
pollution while increasing the volume of oil handled.
Neither the well-being of the fishery resources nor the in-
creased development of the petroleum industry in the
Greater Puget Sound Basin need be mutually exclusive. By
developing stringent, yet realistic, rules and regulations
based on adequate research and applied under local condi-
tions, it should be possible to provide for the orderly de-
velopment of both the petroleum industry and the fishery
resources of Puget Sound.
-------
PUGET SOUND 145
TABLE 2
OIL SPILLS IN THE PACIFIC NORTHWEST
1967-1970
U.S. Coast Guard Oil Spill Investigations1
REPORTED SPILLS ATTRIBUTED CAUSE
Number Major Human Equip- Unknown
of Spills Spills ment
UNITED STATES
19683 714
ATTRIBUTED LOCATION
Shore Ship Unknown
PUGET SOUND ONLY
1967 12
1968 25
1969 18
1970 26
19702 218
33%
20
28
12
4
84%
52
67
62
39
16%
16
22
15
7
0%
32
11
23
54
42%
40
44
50
54
58%
32
50
31
15
0%
28
6
19
31
OTHER PACIFIC NORTHWEST PORTS
1967 20
1968 31
1969 33
1970 42
0%
10
12
2
55%
81
73
62
15%
3
3
5
30%
16
24
33
25%
16
39
37
60%
61
34
42
15%
23
27
21
ENTIRE PACIFIC NORTHWEST
1967 32
1968 56
1969 51
1970 68
12%
14
18
6
66%
68
70
62
16%
9
10
9
18%
23
20
29
31%
27
41
43
60%
48
39
37
9%
25
20
20
42%
49%
1
Accident (Oil Spill) Reports, U.S. Coast Guard, 13th District, Intelligence and Law Enforcement Branch
Washington State Department of Ecology, Monthly Reports of Reported Oil Spills
Department of the Interior data; 0.3% from oil drilling activities.
9%
-------
A JOINT STATE-INDUSTRY
PROGRAM FOR OIL POLLUTION CONTROL
R.W.Neal, G.R.Schimke
ArthurD. Little, Inc.
D.L. Corey
Division of Water Pollution Control,
Commonwealth of Massachusetts
ABSTRACT
This paper describes a project undertaken to establish
specific measures for reducing the threat of oil pollution
and to respond more effectively to oil spills in an intensely
utilized estuarine area near Boston. Its recommendations
are the result of a study of potential sources of pollution
and the mechanisms that spread it. To help design a
fast-response system for containing and removing spilled
oil, the study team developed a computer program that
could predict the probable path of oil spilled anywhere in
the area under various conditions of wind and tide. This
information was used to select locations for containment
devices and determine the speed with which they would
have to be deployed. The study was supported by the
Massachusetts Division of Water Pollution Control and
aided by the active cooperation of local industries through
a joint industry committee.
INTRODUCTION
In all the coastal states, numerous industrial complexes
are located on the waterfront for access to marine shipping.
Industries that handle oil or petroleum products have been
the source of accidental spills that threaten the natural
ecology, and interfere with the recreational and aesthetic
values so prized by property owners, boating enthusiasts,
swimmers, and both commercial and recreational
fishermen. Further pollution is introduced by the disposal
of oily materials in nearby drains that eventually empty
into the estuarine waters.
Description of Study Area
The Town River Bay and Fore River area bordering the
towns of Quincy, Braintree, and Weymouth in
Massachusetts typifies the intense, multiple-use
development of estuarine areas located near large urban
centers. This area located about ten miles southeast of
Boston (Figure 1) is not characteristic of many such areas,
however, because its waters and shorelines still remain
relatively clean. Nevertheless, it is increasingly threatened
by pollution: reported oil spills have increased in all but
one of the past six years, as shown in Table 1.
TABLE 1
OIL SPILLS IN
TOWN RIVER BAY AND FORE RIVER, 1964-1970
Year
1964
1965
1966
1967
1968
1969
1970
No.of
Spills
1
3
7
2
7
11
17
The area has almost 16 miles of shoreline, about 49%
of which is zoned for residential use and 41% for industry.
Public and open-space zoning accounts for about 8%, and
the remaining 2% is set aside for business (see Figure 2).
Almost one fourth of the shoreline is undeveloped and
consists largely of marshes. Beaches and park land occupy a
total of two miles of shoreline.
The area has significant shellfish resources, as shown in
Figure 3, but their utilization is hindered by pollution.
Quincy has 256 acres of "restricted" clam flats and 41 acres
of "seasonal" clam flats; Weymouth has 136 acres of
"restricted" clam flats. The remaining shoreline is closed to
shellfishing. These classifications are based on coliform
standards established by the Public Health Department, but
147
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148 OIL SPILL PREVENTION ...
the areas can also be closed in case of oil pollution.
Professional diggers are permitted to harvest clams in
restricted areas if the clams are taken to a cleaning station.
N.M
MASS
R.I
Figure 1: Location of Study Area
Study Background
Three years ago, recognizing the need for cooperative
action and pooling of resources, seven of the major
industries located on the waterfront formed an Industrial
Anti-Pollution Committee. Among other accomplishments,
they have developed mutual aid response plans for
combating oil spills in the area. Assistance and resources are
offered in all cases, regardless of the spill source. The
member companies and their locations are shown in Figure
4.
Despite the Committee's efforts to prevent, control,
and clean up spills more effectively, incidents have
continued and even increased. Accordingly, the
Massachusetts Division of Water Pollution Control (DWPC)
decided that additional steps were necessary to reduce the
frequency and magnitude of these spills and to halt the
gradual deterioration of the environment that would result
if the apparent trend continued. Working with the DWPC,
Arthur D. Little, Inc. has completed a study in this area
that is viewed as the first step of a longer term program of
positive action. The study produced the following:
(1) Physical surveys of each waterfront activity.
(2) Specific recommendations for changes in equipment
and procedures to reduce the chances of accidental
spills.
(3) Surveys of a large sample of businesses located in the
adjacent drainage areas that might discard oOy wastes
into storm drains.
(4) A detailed survey of surface currents, from which a
computer model was developed. (This model was
utilized to predict the path of oil spills under a
variety of conditions and to calculate the required
response times that must be met for an effective
response system.)
(5) Recommendations for a fast-response system tailored
to the specific needs in this area.
OUINCY
BRAINTREE
• HES10CKTKL MIIIIM mcuSTm»L VTTTH CITr OWCD. PURJC. Off* '•'•"'-'••' fluSMESS
Figure 2: Zoning of Waterfront Property
Surveys of Potential Spill Sources
Clearly, the most desirable and effective means of
preventing oil pollution is to stop spillage. A complete
program of prevention would include: (1) well-engineered
systems incorporating a variety of safeguards that forestall,
or mitigate the effects of both mechanical failure and
human error; (2) well-trained and highly motivated
operating personnel; and (3) a comprehensive system of
reporting and analysis so that the causes of accidental spills
can be established and steps taken to prevent similar future
occurrences.
Although the frequency and magnitude of spills can be
greatly reduced by preventive measures, it appears that
adverse circumstances combine sooner or later and
accidents inevitably occur. When an oil spill results, its
potential seriousness can be mitigated if it is quickly
detected and measures are rapidly employed to confine it.
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JOINT STATE - INDUSTRY PROGRAM ... 149
HESTBICHC ^B CLAMM-KO SEASOWL HtLATIVEL* UNDE VELOPED AND HIGH ECOLOGICAL VALUE
Figure 3: Shellfish Beds and other Areas of Ecological Value
QUINCV
tUJOB INOUSTIilES
E -GEICRAL DTNAMCS.'QUMCr tt\
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Figure 4: Major Industries and High-Use Areas
To develop specific recommendations for changes in
equipment and procedures to prevent oil spills, we
conducted a program of physical plant inspections and
interviews. All plants and facilities located on the
waterfront that handled oil products were included in the
surveys. In addition, a sample of inland businesses that
might be sources of oil wastes via storm drain systesm was
examined.
Waterfront Plants
We conducted surveys at 14 waterfront plants and
facilities. These included:
5 tank farms
1 fuel oil unloading dock
3 power generating stations
1 shipyard
1 soap manufacturing plant
2 yacht clubs
1 marina
Altogether, these facilities have nearly 100 storage
tanks for petroleum products and over 50 for other
chemicals, most of which are filled from ships or barges. In
recent years a number of small spills and five major spills
have been recorded. Of the latter, two resulted from human
error (accidentally leaving valves open), two were due to
equipment failure, and one was associated with an accident
in testing a new ship.
Following these surveys, we prepared
recommendations for each of the facilities. The measures
recommended differed from plant to plant, but they may
be generally summarized as follows:
• Installation of high-liquid-level alarms;
• Regular use of containment booms around ships or
barges during transfer operations;
• Installation of check valves in fill lines;
• Periodic testing and inspection of tanks, lines, and
hoses;
• Erection and proper maintenance of tank dikes;
• Periodic maintenance of valves and joints to eliminate
chronic leadage;
• Careful maintenance of oil-water separators in
drainage systems;
• Improvement of plant security, including the locking
of critical drains and valves;
• Preparation of written procedures for oil transfer
operations;
• Establishment of emergency response plans; and
• Institution of regular training programs for operating
personnel.
Inland Businesses
In addition to direct pollution from waterside sources,
oily substances can also reach the water basins via drains
and sewers from inland sites. Therefore, a second portion of
the survey effort was devoted to investigating the
magnitude of such sources of pollution.
We determined what areas of the towns of Quincy,
Braintree, and Weymouth have storm drain systems that
discharge into the Town River Bay and Fore River. We then
identified all businesses in these areas that could be sources
of oil pollution or of discharges that might occasionally be
identified as oil "slicks." A survey of all possible sources
was not feasible, so a statistical sample comprising 35% of
the total was selected to cover various categories of
businesses throughout the project area. Service stations
were not included, because information was already
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150 OIL SPILL PREVENTION...
available from an earlier study of automotive waste oil
disposal practices in Massachusetts^1)
The larger companies appeared to exercise care in their
disposal of oils and solvents. In most cases they reuse oil, or
oily waste is placed in 50-gallon drums and removed by a
service or taken to the city or town dump. Most of the
small businesses have very little waste in the oil, paint, or
plastics categories, and it usually ends up in the town
dump. Only three of the businesses surveyed might pose an
oil pollution problem, and these are small.
On the basis of this survey and the previously cited
study of automotive waste oil practices, we concluded that
the contribution to the oil pollution problem in this area by
random sources within the drainage area is probably very
small. Service stations and similar operations probably
dispose of approximately 1500 gallons of automotive waste
oil per year in these waters.
Study of Surface Currents
Previous studies gave some insight into the gross
circulation and flushing characteristics of this estuary .(2-5)
However, they did not give primary emphasis to surface
currents and thus did not provide adequate information for
predicting the paths of oU spills. To obtain this data, we
placed floats at various locations throughout the study area
and took periodic aerial photographs of their positions.
The aerial survey data were combined with separate
observations from a small craft to infer the circulation of
the surface water over the entire tidal cycle.
Once the surface current field throughout the region
had been specified, the data were spearated into unit areas
(cells) for computer processing. The computer program was
constructed so that data on a hypothesized spill may be
entered for any location within the project area, at any
stage of the tide cycle, and for any wind speed and
direction. The computer then plots the predicted path of
the spill for further examination.
The model assumes a simple relationship between the
tidal currents off Quincy Point (which are forecast in the
annual tide and current tables issued by the Coast and
Geodetic Survey) and the current in each of the several
hundred cells throughout the project area. Thus, given the
predicted current at Quincy Point and the results of the
survey, the computer can calculate both magnitude and
direction of the current in each cell. A further theoretical
simplification is that the tidal current and the wind-driven
current may be added vectorially and that the wind-driven
current transports the oil at 3% of the wind speed in the
direction of the wind.
The model does not reflect the continuous changt in
the shape of the shoreline with the tide; as a result, it may
predict movement of an oil slick across exposed tidal flats.
However, the computer printout identifies the general
physical makeup of each cell by means of a predetermined
code. The model computes the path of the oil until it enters
a cell consisting entirely of dry land, at which time the
calculation terminates and the path is plotted on a cathode
ray tube and on a printout.
In the calculation it is assumed that the oil can be
represented as a single spot. The model does not take into
account the spreading of the oil, nor does it recognize the
possibility that the oil can be transported along the beach
by wind currents. However, it does show the generalized
path that the oil will follow under specified tidal current
and wind conditions. Examination of the plot gives insight
as to how much of the shoreline will be affected.
Figure 4 shows the principal potential sources of
accidentally released oily substances and thier proximity to
the principal high-intensity use areas along the shoreline.
We hypothesized spills at each of the potential sources
under various wind and tide conditions to determine the
minimum amount of time available for protective response
measures.
Figure 5 shows the distribution of minimum travel
times for each of the eleven destinations. Under conditions
that favor rapid oil transport, every destination except No.
7 (far up the Fore River) can be reached by oil in less than
an hour from one source or another; the mean time for
spills to reach the critical throat area (where the installation
of barriers is reasonable) is on the order of 20 minutes.
Typical computer plots are reproduced in Figures 6A
and 6B. The former shows the effect (on the path of oil
spilled at source D) of a 5-knot wind blowing in three
different directions. (Note that the "wind bearing" is that
toward which it blows.) Figure 6B shows oil movement
from sources A, D, and G at maximum ebb current with a
6-knot southeast wind.
Fast-Response System
The key factors in minimizing the damage associated
with an oil spill are early detection, rapid containment and
control, and physical removal of the oil. In the confined
and heavily populated estuarine area covered by this study,
oil not quickly contained and removed will cause
immediate and serious damage. Our recommended response
system emphasizes these three steps, and is designed to
supplement local containment and cleanup procedures
which would be undertaken in any case by the responsible
and cooperating parties.
If the system is to be properly designed, its objective
must be clearly spelled out. Its cost depends on the size of
spill which the equipment must handle and on the
requirements for containing the spill. Considering the area's
topography and past history of spills, we believe that the
following response system requirements are reasonable:
• Containment of the spill within the branch of the
estuarine area in which it occurs and protection of
the other branches from oil intrusion.
• Capability to pick up oil in a 1/4-inch slick at a rate
of 50 gallons per minute.
Containment depends on the speed of detection and
the capacity of the containing equipment. Removal rates
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JOINT STATE - INDUSTRY PROGRAM
151
depend on equipment capacity and crew size. Spills which
;xceed the design rate of removal will cause damage and
necessitate additional cleanup operations. Thus, the
selection of a design performance level is a calculated risk.
The demonstrated capabilities of available hardware
fall considerably short of the requirements of a
fast-response system, but better equipment (barriers in
particular) is being developed and may be available soon.
Booms have been demonstrated to be effective in
containing oil spills in calm harbor waters, but they require
i significant time for deployment. Air barriers, which can
be activated very quickly, have undergone only limited
containment tests; they need additional testing and redesign
before they can be considered efficient and reliable.
CO
-
17
U
UJ
Q 8
10
11
«
• ••••*•• •
0 1.0 2.0 10
MINIMUM TRAVEL TIME (hours)
Figure 5: Minimum Travel Time: Frequency of Occurence by
Destination Number
Detection
The effective application of a fast-response system
depends on early detection of an oil spill. Detection can be
sr/wr TBC> 4-co
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Figure 6- Oil Spill Paths Obtained by Computer Simulation
enhanced in three basic ways. First, operators must be alert
ot the appearance of an oil slick on the water and to
unusual conditions in the plant which might be expected to
result in a spill. Second, control systems within the plant
should include, where possible, alarms to warn of
conditions (e.g., high tank levels) that might result in a spill.
When such alarms are activated, personnel should check the
area for spillage. Finally, continuous instrumental
monitoring of surface water and plant effluents could give
immediate detection.
Ideally, it would be desirable to monitor for oil at each
point where a major spill could enter the estuary, but the
present high cost of the available instruments, together with
the uncertainty -as to their reliability and durability in a
heavily populated estuary, argue against this approach.
Considerable development is under way and should be
followed carefully; meanwhile, a trial installation in the
vicinity of a selected plant is under consideration.
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152 OIL SPILL PREVENTION ...
Figure 7: Containment Branches and Potential Boom Locations
Containment
To meet the basic containment requirements, barrier
protection must be available at the locations shown in
Figure 7. A spill in Branch II would be contained by a
barrier at location a-b or d-e, depending on tide and wind
conditions. A spill in Branch I would be contained by a
barrier at location a-c. It is unlikely that barriers at a-b and
a-c would be required simultaneously.
This protection could be provided either by one of
several commercially available booms, which must be towed
into place following a spill, or by air barriers, which are
installed beforehand and activated by starting the
compressors which supply air to them. The relative merits
of booms and air barriers are summarized in Table 3 and
discussed below.
Table 3: Comparison of Booms and Air Barriers
Disadvantages
1. Must be physically drag-
ged into position.
2. Impede boat traffic when
deployed .
3. Subject to wear and tear
on handling.
4. Subject to damage and loss
of effectiveness in pack
Advantages
BOOMS
1. Well tested in many appli-
cations.
2. Will contain oil in currents
up to several knots in
calm water.
3. Lower cost - $5-20/ft for
calm water applications.
4. Little preventive mainte-
nance required.
AIR BARRIERS
1. Available for immediate
use, once installed.
2. Do not impede boat traffic.
3. Should be effective in
water containing pack
ice.
1. Relatively little available
performance data.
2. Pass oil in relatively low
currents (0.5-1 kt.)
3. High cost ($30-50/ft).
Cost per foot increases
with length due to air
supply requirements.
4. Should be submerged at
least 5-6 ft but prefer-
ably not deeper than
25ft.
5. Regular maintenance re-
quired on submerged
pipe and air supply.
Booms
A fast-response system for use today would have to
rely on booms for containment of spills. Many booms have
been tested and are commercially available.
Two booms will be required. One, approximately 1200
feet long, should be stored at point a (Figure 7) for
deployment either to point b or c as conditions require.
The other, approximately 1700 feet long, should be stored
at point d for deployment to point e.
, OIL SLICK CONTAINED BY
INDUCED SURFACE CURRENTS
Figure 8: Air Barrier Operation
End closure of a boom poses no real problem if it can
be attached to bulkheads that continuously draw water.
Sliding supports can provide secure anchoring at any water
level. Problems arise, however, if the horizontal position of
the waterline changes with the tide, or if the boom crosses
mud flats that are exposed at low water, as would occur
between points d and e. For ease of deployment of the
boom and effective end closure, 3-5 feet of water is
required. To assure this depth under any tidal condition, a
channel must be dredged and piers constructed at each end
to support sliding boom attachments.
Air Barriers
Air barriers are just now coming into use for
containment of surface contaminants. The basic principle is
shown in Figure 8. Air is pumped through a perforated pipe
laid on the bottom or floated at any desired level. The
rising air entrains water, causing an upwelling which is
converted to a current away from the barrier at the surface.
The induced current opposes any natural current coming
toward the barrier, thereby restricting the spread of surface
contaminants.
The critical parameters of air barrier installations are
not well defined, but it appears that the pipe must be at
least 6-10 feet below the surface. At shallower depths, the
air geysers out at the surface and only small surface
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JOINT STATE - INDUSTRY PROGRAM ... 153
currents result. The maximum depth for effective
containment depends on the currents in which the system
must operate. Tidal currents deflect the air screen and
reduce its effectiveness in proportion to the depth of the
pipe. In addition, increasing the depth of the pipe increases
the air pressure required to activate the system, resulting in
larger pumping costs and in larger capital outlay for more
powerful compressors. The optimum depth appears to be in
the range of 10-25 feet.
Limited tests to date suggest that the containment
capability of air barriers is significantly degraded in currents
as low as 0.5-1 knot. Oil tends to pass the barrier by being
drawn into vortices near the barrier, carried through the
barrier by the vortices beneath the surface, and released at
the surface downstream of the barrier. This problem can be
partially alleviated (at greater expense) by installing the
barrier at an angle to the flow.
To reduce air pumping costs and capital equipment
costs, and to reduce the effect of currents, floatable air
barriers are being investigated/^) The pipes lie on the
bottom when not needed and quickly rise to the optimum
depth when air is supplied. These would be useful in the
deep waters at locations a-b and a-c.
As with booms, the mud flats at location d-e prevent
the use of an air barrier at low water unless a trench is
dredged.
The potential advantages of air barriers are particularly
important for a fast-response containment system in a busy
estuary. In addition, they offer the possibility of keeping
the barrier locations ice-free. Either air or warm water from
a utility company's cooling water effluent could be
continually pumped through the air supply system during
the winter. This circulation would also flush the air supply
pipe and prevent possible clogging of the nozzles. The
feasibility of continuous circulation requires detailed
engineering analysis, however.
Therefore, we recommend that air barriers be strongly
considered .for use in the long-term system and that a
demonstration program be initiated to test them in this
application. On the other hand, we do not believe that their
present state of development permits their use as key
elements in a present-day fast-response system. The long
lengths required and variable depth conditions at the barrier
locations pose application problems that press or exceed
the state of the art.
Removal
Many skimmers and other oil collection devices are
currently available or under development, and several are in
regular use in estuarine areas. Difficulties with respect to
collection efficiency and operating reliability have yet to be
solved, however, and intensive development effort is
under way.
The recommended boom configuration suggests that
most contained spills will be collected in the vicinity of
points a and b, but the remaining collections could be
scattered throughout the study area. The collector should
therefore be portable and based in the vicinity of points a
and b. Portability, together with an ability to pick up oil
from a 1/4-inch slick at a rate of 50 gallons per minute,
indicates that a moderate - sized, self-propelled unit is
required.
Collected oil can best be stored in rubber bladders
towed by the collector. Such bladders are commercially
available in sizes ranging from 55 to 515 gallons; these have
built-in hose connections for oil transfer and can be rolled
on land as well as towed in the water. Several of these
bladders should be available, and a method for changing
bladders during collection should be devised. Collected oil
can be stored in the bladders until suitable disposal
arrangements can be made.
Auxiliary Equipment and Supplies
In addition to the specific equipment described above,
boats will be needed to deploy the booms, and one or more
trucks must be available to carry away the collected oil.
The only additional requirement is a plan which assures the
immediate availability of this equipment when required.
Absorbents will be needed to clean up any oil which
escapes containment and reaches the shore. In this case, fast
response is not of prime urgency. We recommend that a
small stock of treated straw be kept available for minor
cleanup operations and that the procedures for cleaning up
major spills which reach the land be decided upon when
and if such situations occur. Chemical dispersion or sinking
is not considered to be generally suitable in this area.
Operational Requirements
To provide fast and effective response to an oil spill,
the key operational requirements are:
• A central control location through which rapid
telephone contact with a Control Chief is assured.
The Control Chief should be a knowledgeable, trained
person with access to contingency plans that describe
whether and where booms should be deployed,
depending on the source and size of the spill, the tide,
and wind conditions.
• Immediate availability of a trained crew to deploy the
booms and to activate the skimmer. At this time, we
believe that a five-man crew is sufficient to put the
fast-response system into operation: three men with
one boat to deploy the booms, and two to activate
the skimmer. Following the immediate response,
additional men will be required within a few hours to
assist in the cleanup and to dispose of collected oil.
• A detailed set of contingency plans (referred to
above) which specify the action to be taken for any
foreseeable emergency condition. These plans allow
rapid response by the Control Chief; only in
exceptional cases should he be required to exercise a
significant amount of personal judgment in activating
the fast-response system.
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154 OIL SPILL PREVENTION ...
The decision of whether or not to deploy the system in
a given situation must be made quickly, on the basis of
perhaps limited information available at the time the spill is
detected. The basic criterion should be the minimum size of
the spill, such as 100 gallons, a figure that would be
specified in advance. If the amount is not known, it is
better to put the system into operation than to risk the
damage from an underestimated spill.
Special charts can be made to help response personnel
decide which barriers) to deploy. One would furnish the
tide condition for the particular time and date; another,
based on the information developed with our oil path
model, would specify where barriers were needed for that
tide condition and the prevailing wind direction, and (if
applicable) the order in which they should be deployed.
Local response to an oil spill must be coordinated with
state and federal plans and procedures for dealing with
spills. The DWPC is developing a statewide contingency
plan which will enable the state to ensure that effective
action is taken. Current thinking is that the DWPC should
be notified of any spill in the waters of the Commonwealth
so that it can:
• see that all possible appropriate corrective action is
taken by the responsible party,
• coordinate state activities at the site as required,
• request assistance from the U.S. Coast Guard, the
WQO regional office, and/or outside contractors, as
required,
• approve chemicals used in cleanup and the methods
of disposal of collected oil,
• work with the Attorney General's office to recover
costs, expenses, and damages to the Commonwealth,
and
• take follow-up action as required to prevent
recurrence of the spill.
The federal plan(7) requires that the Coast Guard be
notified in the event of a spill and describes the manner in
which the response of interested federal agencies will be
coordinated.
SUMMARY
This project comprised physical plant inspections,
physical surveys, technical studies, and analyses for the
purpose of developing specific recommendations for a
program that will lead to improved prevention and more
effective control of oil pollution in the waters of the Town
River Bay and Fore River, bordering the towns of Quincy,
Brain tree, and Weymouth.
We conducted individual plant surveys of all the
waterside industrial operations and developed for each a set
of specific recommendations for equipment and methods to
improve the prevention of oil spill accidents. In addition,
after identifying the businesses in the parts of the three
towns where storm drainage empties into the waters of the
study area, we physically surveyed a selected sample of
those that might dispose of waste oil (or oily substances) in
storm drains.
We designed and carried out a study of surface currents
utilizing aerial photography and surface floats. These results
were combined with those obtained by other investigations
of water currents in this area to establish the true pattern of
surface currents over a complete tidal cycle. Weather
Bureau data on wind speed and direction were then
incorporated with the surface current findings, and a
computer model was developed that could predict the path
and travel time of an oil spill occurring at any selected
location.
Records of past spills in the project area were compiled
from a variety of sources. These were analyzed to show
frequency of occurrence, seasonal patterns^ sources, and
causes (when known).
Combining the results of the above work, we developed
a set of recommendations for improved prevention and
described a system of equipment and procedures that
would provide a true fast-response system for effective
action if a spill does occur.
By forming and participating actively in a mutual aid
group, the indistries have already done much to maintain
the quality of this area. Some of the companies involved
have already begun installing equipment recommended for
spill prevention. The Industrial Anti-Pollution Committee is
presently studying the recommendations for a fast-response
system to determine what further steps the joint industry
group can support.
By initiating and supporting this study, in which all
concerned industry groups have fully cooperated, the
Massachusetts Division of Water Pollution Control has
taken the first step in what must be an on-going program to
reduce still further the threat of oil pollution and to
preserve this estuarine area. Putting our recommendations
into practice will require additional effort if tangible
benefits are to be realized. The DWPC, with the
cooperation of the local industries and the support of
interested federal agencies, should continue to supply the
required leadership.
The demonstration of an organized regional approach
to the prevention of oil spills and the limitation of spill
damage could be of widespread importance. The concept of
investing in a fast-response system to reduce the future
costs which would accrue from spills not otherwise
contained can)be applied usefully in industrialized port
areas,around the country.
REFERENCES
1. "Study of Waste Oil Disposal Practices in Massachusetts"
January 1969, C-70698, Arthur D. Little, Inc.
2. "Tidal Current Tables, 1970," U.S. Department of
Commerce, Environmental Science Services Administration.
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JOINT STATE-INDUSTRY PROGRAM... 155
3. U.S. Naval Oceanographic Office, "Field Report,
Weymouth Fore River Dye Dispersal Test, Quincy,Mass.,"
Unpublished Manuscript.
4. Dayton E. Carritt - "Report to the Boston Edison
Company on the Conditions of the Marine Environment
Pertinent to Siting a Nuclear Power Plant on Weymouth
Fore River," 1966, Unpublished Manuscript.
5. Weston Geophysical Engineers, Inc., "Hydrographic
Survey, Weymouth Fore River, East Braintree,
Massachusetts," June 1970, for Braintree Electric
Department under the direction of R.W. Beck and
Associates.
6. J. Grace and A. Sowyrda, Journal WPCF, XLII, No. 12
(December 1970), pp. 2074-2093.
7. "National Oil and Hazardous Materials Pollution
Contingency Plan," Council on Environmental Quality,
Federal Register, June 2, 1970.
-------
THE ALBERTA OIL SPILL
CONTINGENCY PLAN
J.G. Gainer
Environmental Conservation Committee
Canadian Petroleum Association
INTRODUCTION
The Environmental Conservation Committee of the
Canadian Petroleum Association undertook the task of
investigating the reports of several serious oil spills in the
province in 1970, in order to determine how the industry
might minimize the dangers of an apparently growing
hazard. The committee's limited investigations indicated
that, as in the early cases of the "Torrey-Canyon" disaster,
the Santa Barbara Coast spills and the recently published
McTaggert - Cowan report of the "Arrow" incident, the
problems were not so much due to lack of equipment and
containment techniques, but rather in their proper
deployment.
In each of these studies, it was most apparent that a
single authority or "task force commander" should be
immediately designated, and that a consistent approach to
any given problem must be maintained. The particular
approaches may vary for spills occurring on the high seas,
coastal or inland waters, but some established plan must
exist.
It was in this vein that the committee addressed itself
to the peculiar problems of Alberta where production and
pipeline operations were carried out in the forested
foothills, arid plains, nothern muskeg and in close
proximity to rivers and lakes. Initial discussions were held
with the staff of the Department of Lands and Forests who
were able to lend their particular expertise in these diverse
environmental studies. It was realized early in our
discussions that there were striking similarities between the
organization which would be required to combat a major
oil spill, and that which already existed in the Fire Fighting
Service of the Department of Lands and Forests.
The outcome of these discussions was that the
Canadian Petroleum Association accepted the responsibility
of developing a joint Industry-Government Contingency
Plan for the control of oil spills throughout the province. A
six-man "Alberta Oil Spill Contingency Plan Task Force"
was immediately formed with members of C.P.A. and
I.P.A.C. representing both the Production and Pipeline
segments of the industry.
Concurrently, with the CP.A.'s initial investigations, a
petroleum industry spill control cooperative was formed in
the Pembina Area under the chairmanship of Amoco
Canada Petroleum Company Ltd. Throughout the
development stages of the Provincial Plan, the Task Force
maintained an extremely close liaison with the Pembina
Cooperative.
The proposed plan has drawn upon the considerable
corporate experience of the Task Force member companies,
as well as model contingency plans advanced by such
industrial associations and governmental agencies with
which they are in contact throughout the world. Locally,
we have taken into consideration the advice of the
Department of Lands and Forests as well as the practical
knowledge developed by the Pembina Cooperative.
The plan has been briefly reviewed with the Chairman
of the Oil and Gas Conservation Board, and has received
approval in principle from the Board of Directors of the
Alberta Division of the C.P.A.
Scope of the Plan
In our initial discussions with the Department of Lands
and Forests, it was agreed that the authors would take
considerable liberties in defining the roles of the
governmental departments and regulatory agencies involved
in pollution control, in order to design an effective
emergency organizational structure. We believe that the
plan is pragmatic, but we realize, that in order to
implement it, some changes will be necessary in the
presently defined jurisdictions and responsibilities of
certain departments and regulatory agencies. We recognize
also, that many changes will evolve with the formation of
157
-------
158 OIL SPILL PREVENTION...
the recently announced Department of Environmental
Improvement.
Figure I presents the scope of the Contingency Plan, in
terms of the problems encountered throughout the
principal four facets of the petroleum industry, together
with the approach to the problems in defining the
respective roles of industry and government. The plan is
drawn up on the premise that industry will take care of its
own problems, and only where the spill exceeds the
capabilities of the operating companies will the combined
forces of the public and private sectors be utilized.
Our plan concentrates on pipeline breaks and' spills
from wells or other producing facilities and does not
concern itself directly with manufacturing and distribution
which are a more localized technical problem. Large spills
resulting from the manufacture and distribution of
products could well be handled by our proposed structure.
structure.
The plan is predicated upon the assumption that spills
will occur, through material failure, operating errors, or the
actions of forces outside the industry; and for this reason, it
may be considered as a remedial action program only. The
existence of such a plan will however, generate a greater
pollution control awareness at all operating levels, and thus
it will serve a secondary purpose by strengthening the
design and practice of other existing preventive programs.
COVEKMMEHT
HH>OUCT»O«i
- fOUCt
- f.m.a.
- court
Figure 1
By this plan we recognize industry's responsibility to
train the civil authorities and agencies in certain aspects of
petroleum technology; to prevent the possible confliction
of pollution control practices with industrial safety
procedures. An example of this apparent paradox is the
case of a leak in a products pipeline carrying a highly
volatile hydrocarbon stream. Whereas pumping would
normally cease in the event of a break; in this instance, the
preferable procedure might be to increase the pump rate in
order to replace the light hydrocarbon with a safer, less
volatile product.
The plan may be defined as a major spill plan and, as
such, is not concerned with the lowhazard spills on lands
which are not endangering water bodies or water courses,
but rather with those spills which pose a potential threat to
the environment beyond the immediate confines of the
producing or pipeline facility.
Throughout the province approximately 14,000 wells
are capable of delivering oil, although less than 9,000 are on
production in a typical month. The wells are contained in
over 180 producing areas as defined by the Oil and Gas
Conservation Board field limits.
The contingency plan proposes a grouping of the 180
producing areas into less than 20 spill control units, with
the allocation based upon the local operator's radius of
responsibility, and the degree of hazard for the respective
area as determined by evaluating the parameters listed in
Figure 2. In addition to applying purely industrial statistics
to these parameters, the careful consideration of the four
points listed under item No. 8, in determining the degree of
hazard, is a clear illustration of the Canadian Petroleum
Association's officially expressed support of the
"multiple-use" concept in evaluating all natural resources.
Inter-company cooperatives organized in each of the
20 areas would constitute the basic units in the plan, and
provide the first line of defense in the event of a major spill.
To illustrate the manner in which a cooperative might
function, we will outline the organizational work of the
Pembina Area Pollution Control Cooperative Committee.
Pembina Area Pollution Control
Cooperative Committee
On August 18, 1970, the operating companies in the
Pembina area met to form a committee for the purpose of
establishing procedures for the effective control of major
spills which could result in the pollution of the Pembina
and North Saskatchewan river systems. In order to attain
these objectives, three committees were formed and
provided with the terms of reference shown in Figure 3.
The prime objective was an evaluation of the drainage
basins to select sites where corrective action could be taken
to prevent pollution of major streams. The second objective
was to evaluate available control equipment and cleanup
materials.
That the Pembina plan fully recognizes the autonomy
of the member companies is seen in the recommendations
that all equipment will be privately owned and that the
operating company responsible for the spill will provide the
"on-scene" commander for all incidents. The alternative
procedure of assigning a standing "on-scene" commander
has the advantage of a permanent organization, but it
unfortunately results in a change of command when a spill
threat responsibility is handed from the single operator to
the cooperative's control.
The Equipment Committee has investigated materials
available from some 90 suppliers and evaluated several
locally fabricated containment and cleanup devices.
Preliminary tests have indicated that many commercially
-------
ALBERTA CONTINGENCY PLAN 159
PEMBINA AREA POLLUTION CONTROL
CO-OPERATIVE COMMITTEE
PLANNING ORGANIZATION
STEERING COMM.
- PURPOSE
- BOUNDARIES
- COMMUNICATIONS
- REGULATIONS
DRAINAGE BASIN
- TOPOGRAPHY
- ROADS
- CONTROL PTS
- REGULATIONS
- MANUAL
EQUIPMENT & MATERIAL
- CONTAINMENT
- REMOVAL
- INVENTORY
- LOGISTICS
Figure 2
ALBERTA OIL SPILL CONTINGENCY PLAN
PRODUCTION OPERATIONS - DEGREE OF HAZARD
1. NO. OF WELLS
2. PRODUCTION RATES (PER UNIT)
3. TOTAL PRODUCTION
4. REMOTENESS
S. AGE OF EQUIPMENT
6. HISTORY OF SPILLS
7. PROXIMITY TO MAJOR WATER COURSES
8. USE OF WATER COURSE
(A) DOMESTIC SUPPLY
IB) FISH ft WILDLIFE
1C) RECREATIONAL
(D) AGRICULTURE
Figure 3
available devices require considerable modification to meet
the local requirements.
The Drainage Basin Committee has prepared draft
copies of the Contingency Plan Manual, which will,when
finalized, be distributed to all Government and Regulatory
agencies as well as to key operating personnel among the
member companies. The plan outline is essentially shown
under the "Index" displayed in Figure 4.
The maps constitute the key sections of-the manual.
The National Topographic Series provide data on surface
features, main roads and drainage systems, while the
Alberta Lands and Forests maps contain current data on all
production facilities, secondary and private roads. Through
the parallel series of maps, which have been reduced to a
common scale with a complete cross-reference system based
PEMBINA FIELD
MAJOR OIL SPILL CONTINGENCY PLAN
INDEX
EMERGENCY PROCEDURES
COMPANY CONTACTS
GOVERNMENT CONTACTS
EQUIPMENT CHECK LISTS
EQUIPMENT USAGE
CONTROL POINT DESCRIPTION
MAPS - NATIONAL TOPOGRAPHIC SERIES
- LANDS 8c FORESTS
Figure 4
CONTROL POINT CLASSIFICATION
TYPE A. LARGE RIVERS TYPE B. SMALL RIVERS 8 CREEKS
/>04o-\ ,-CUIXHT
TYPE C. SMALL RIVERS 8 CREEKS
-tmoee
TYPE D. SMALL RIVERS ft CREEKS
Figure 5
on the Legal Survey, an operator can locate the spill and
dispatch equipment and personnel to the site by the
shortest and safest route.
The maps are a clear manifestation of excellent
Industry-Government cooperation, for without the
assistance of the respective Federal and Provincial
departments in this compilation, the final cost of the
manuals would have increased tenfold.
A detailed ground reconnaissance by the Drainage
Basin Committee produced the series of control point types
presented in Figure 5.
Type A represents the most feared form, where the oil
has entered a large river.
Types B and C represent a spill in a small stream, with
banks, which could be controlled with limited equipment
-------
160 OIL SPILL PREVENTION
PEMBINA COOPERATIVE
EQUIPMENT CHE C K LIST
TYPE OF SPILL
EQUIPMENT REQUIRED
AIRPLANE
BOATS
WINCH TRUCKS
LIGHT PL
VACUUM TRUCKS
- DISPATCH IMI
- OPTIONAL
Figure 6
supplementing the existing roadways to form
pseudo-natural barriers or separators.
Type D suggests a point in a stream where no natural
bank exists and a supplementary lateral barrier would be
required.
Based on this categorization, the equipment required
to clean up a specific spill is readily determined by referring
to the Equipment check list shown in Figure 6.
The preceding three exhibits represent only a small
portion of the total manual, but serve to illustrate how
intensively the Pembina group has studied the problem, in
order to provide an entirely practical communication and
action plan.
As other areas are organized, each will prepare similar
books, copies of which will be supplied to the Conservation
Board as well as the Provincial Organization, so that any
spill may easily be referenced and categorized when re-
ported or when assistance is requested.
Provincial Plan
Figure 7 illustrates the 16 drainage basins in the
province. Ten of these basins contain petroleum production
operations, and each of these has been studied in some
detail to establish the degrees of hazard, and the possible
number of control areas required.
The most southerly basin, the Milk River, will require
additional special study because it is part of the Mississippi
system and therefore falls within the jurisdiction of the
International Joint Commission. This presentation will
consider only the Alberta and the interprovincial drainage
basins. In finalizing the contingency plan, due consideration
will be given to regualtions under the Federal acts
pertaining to interprovincial streams. At this time we have
reviewed only the Navigable Waters Protection Act in
reference to establishing permanent control point anchors
and oil retention booms in the Pembina Area.
The Proliferation of pipelines and the density of
ALBERTA
DRAINAGE BASINS
Figure 7
producing areas shown in Figure 8 indicate the magnitude
of exposure to potential spills in each of the river basins.
The light areas represent heavy oil production which
does not pose a serious containment problem but may well
require specialized cleanup techniques.
The North Saskatchewan River Basin has conceivably
the highest exposure to potential spills in light of the large
-------
ALBERTA CONTINGENCY PLAN 161
ALBERTA
OIL FIELDS a PIPELINES
Figure 8
number of highly productive oil fields.the concentrations of
refineries in the greater Edmonton Area, and the numerous
major pipeline river crossings. Fortunately, the two most
advanced contingency plans have been instigated in this
basin, namely:
(i) Pembina Area Cooperative.
(ii) Edmonton Area - Survey and Contingency Plan for
the North Saskatchewan River.
The Edmonton Area Study will provide:
(1) Specific recommendations for the control and
recovery of oil spills in the North Saskatchewan River
by the strategic location of booms through full
utilization of the established river flow
characteristics.
(2) A general procedural manual which outlines the
application of available hydrological data in
predicting the movement of oil slicks in other rivers,
where subsequent spill contingency plans may be
desirable.
Significantly, the Edmonton study will include boht
open water and ice-bound conditions, to further
complement the Pembina program, which has to date been
limited to the summer state only. The data derived from
the two plans will considerably reduce the time required to
formulate in detail other area contingency plans.
In Figure 9, cooperative centers are listed for the
protection of the six river basins which contain the largest
number of producing wells.
The Pembina area ranks first in degree of hazard based
on operating wells, but it ranks last in terms of production
per well. The Rainbow wells produce in excess of 700
Bbls./day and represent the greatest hazard on a per well
basis. The detailed ranking of all fields is too extensive for
this presentation, but the majority of the larger fields have
been shown.
The Snipe Lake field is shown in two drainage basins,
but the control center has been selected as Valleyview,
where the field offices, industry services and
communication centers are located. We would solicit the
assitance of the Department of Lands and Forests in
designating other drainage area border cases which cannot
be defined solely by the logistics of the industry.
The industrial Edmonton area, and the Fort McMurray
oil sands projects cannot be categorized by the same
parameters used in the production areas, but the follwoing
pipeline capacities adequately indicate the importance of
these areas:
I.
:
45,000 B/D
Fort McMurray
Edmonton
-Light and Medium Crude 1,043,000
-Synthetic 45,000
-Pentanes Plus and LPG's 75,000
TOTAL
1,163,000
Figure 10 shows the communications structure of the
plan. The bottom tier shows the individual oil spill
cooperative areas which handle their own spills to the limit
of their capability. This could include isolated pools which
do not belong to a cooperative.
We recommend for simplicity and uniformity that
emergency reporting be done, as shown, to a single point,
which would have a 24-hour answering service. It is
suggested that this be tied in through the Oil and Gas
Conservation Board's telephone exchange.
-------
162 OIL SPILL PREVENTION ...
COOPERATIVE CENTRES
pence
SMOKY
ATHA8ASKA
M 5ASK
ZAMA
RAINBOW
SNIPE
KAYBOB
SNIPE
SWAN H.
MeMURRAY
PEUBINA
LEDUC
REDWATER
EDMONTON
STETTLER
JOFFRE
299
169
312
181
189
102
157
107
IT,
SI
2970 2670
1083 471
794 278
(INDUSTRIALI
633
M3
291
211
ZAMA
RAINBOW
FOX CREEK
VALIEYVIEW
MeMURRAY
DRAVTON
DEVON
EDMONTON
EDMONTON
STETTIER
RED DEER
Figure 9
0
1 1 T"""| ..... | »
r-L-,rJ-,rJ-irJ-ir-L,
TOHS IOMONKM «CFHOIV MM) < -
i 1 1 1 1 1 1 ii 1
Figure 10
We further recommend that this reporting procedure
be extended to also include pipeline oil spills but only for
emergencies with other normal reporting requirements
remaining unchanged. Communication would be made from
this point, as necessary, to other agencies and Government
Departments. Where an area cooperative or isolated
operator cannot cope with a spill, the communication
would continue to the Forest Protection Service of the
Department of Lands and Forests which we have shown as
the emergency organization to combat serious spills. Other
functions are also shown on this figure but they are
auxiliary functions and not directly involved with the plan.
Figure 11 shows the normal communication routing
under various circumstances and conditions. The legend
describes the symbols. It should be noted that "B-Board
and/or Pipeline Branch" is our recommended Conservation
Board Emergency Communication Point and "D-Provincial
Organization" is the Forest Protection Service of the
Department of Lands and Forests.
The Communications, under emergency conditions,
would originate with the spill observer, probably an
ALBERTA OIL SPILL CONTINGENCY PLAN
INITIAL COMMUNICATIONS PROCEDURE
NORMAL ACTION EMERGENCY fiCTinw
SOURCE
IDENTIFIED
AS SELF
AS OTHER
OPERATOR
SOURCE
UNIDENTIFIED
OR OPERATOR
UNAVAILABLE
MINOR
OM GROUND MARSH
OR ISOLATED SLOUCH
NOT MIGRATING
A -B
0-A_B
\
INTERMEDIATE
POTENTIAL MIGRATION
(CONTt*IUING SPILL.
SPRMG BREAKUP. PREC 1
0 — A;-— B
0— B-— A
\t
MIGRATING
\t\
°
0— A B
\!\
0— B, — -A
MAJOR
SPILL OM LAKE
Oft STREAM
0 -A -B
'N
C >D
0 — -B -A
O - OBSERVER
A - OPERATOR RESPONSIBLE FOR SPtLL
i - BOARD AND/OR PIPELINES BRANCH
C - AREA CO-OPERATIVE
0 - PROVINCIAL ORGANIZATION
—- MANDATORY
- — DISCRETIONAL
Figure 11
ALBERTA OIL SPILL CONTINGENCY PLAN
SERVICES AVAILABLE FROM DEPARTMENT OF LANDS & FORESTS
1. MANPOWER
2. EMERGENCY POWERS
3. MOBILITY
4. STRATEGIC BASES
5. COMMUNICATIONS
6. PUBLIC RELATIONS
Figure 12
operator, who would report to the Communication Center's
emergency number.
If the responsible operator cannot be identified or
located or is not competent to clean up the spill, the
Conservation Board would immediately engage the services
of the area cooperatives' members. If the spill is beyond the
capability of the area cooperative, or is in an isolated oil
pool or section of a pipeline which is not attached to a
cooperative, then the Board will immediately contact the
Provincial Organization which will actuate its emergency
procedures to contain and clean up the spill.
Where, in the opinion of the Board no emergency
exists, it would identify and contact the responsible
operator to undertake cleanup or, failing this, it would
engage antoher operator, the area cooperative or a
contractor to clean up the spill.
-------
ALBERTA CONTINGENCY PLAN 163
In the extreme situation where the Provincial
Organization is called into action, it would take complete
control under its emergency powers and would quickly
deploy manpower, equipment and supplies as necessary in a
particular situation to contain and clean up the spill.
We strongly recommend that the Department of Lands
and Forests, through its Forest Protection Service, be
designated as the "Provincial Organization" and given full
emergency powers for combatting oil spills, equivalent to
the powers it has for fighting forest fires. With such an
expanded role, additional operating and capital funds will
be required by the Department, but at this point in the
planning, it is difficult to forecast the incremental cost.
Figure 12 enumerates the reasons why we believe that
the Department of Lands and Forests is best qualified to
act as the ultimate oil spill control agency. Industry could
duplicate these services although at great cost, but without
emergency powers it would be severely hampered in
combatting spills and we therefore strongly urge the
Government to permit utilization of this existing
organization.
One of the major problems encountered by both the
Pembina Cooperative and the Contingency Plan Task Force
in the early planning stages was how to protect the
operator or cooperative against financial loss, and third
party liability, when they undertake to control and clean
up a spill where emergency action is necessary but the
action has not been requested by the operator responsible
for the spill. Such a situation could result from such things
as:
-an unidentified spill
-the responsible operator being unavailable, or
•the offending operator not being competent to control the
spill and unwilling to engage assistance.
In such a situation the law does not indemnify the good
Samaritan for costs or third party liability and, therefore,
unless help is requested by the offending operator, a second
party is not inclined to place himself in jeopardy.
The Oil and Gas Conservation Board has powers under
the Act to take control and to engage third parties for
specific services such as controlling wild weils, and also to
recover the costs of such actions. In such cases the Board's
agent is protected. The Board's powers do not appear to be
sufficiently broad, however, to cover all manner of
situations concerning oil spills and it appears that
amendments of the Act and Regulations are necessary. With
such expanded authority the Board could, where a reported
spill requires immediate action, engage a contractor,
operator or an area cooperative to control and clean up the
spill and such agent would then be protected. Upon
completion of the cleanup, all costs incurred could be
assessed against the responsible operator or in the case of an
unidentified spill, be appropriated from the Board's
operating fund.
Similarly, where a spill is sufficiently serious to require
the services of the Department of Lands and Forests, the
Department could be engaged as an agent of the Board and
its costs recovered as above or it could, through legislation,
acquire the power to assess costs of control and cleanup
directly to the offending operator. The Task Force favors
the plan involving the Board as the agency to whom the
offender is accountable.
It should be pointed out here that major spills which
would involve the Department would virtually all be
identifiable, thus practically eliminating the need to draw
on a special fund for the cost of unidentified spills.
In summary then we offer the following comments:
As stated previously the industry plans to tend to its
own oil spill problems through cooperative effort in the
various areas. An occasional serious spill will occur which
will be beyond the local organization's ability to control.
For such a situation an emergency organization will be
needed for the reasons enumerated, and we have
recommended that the Department of Lands and Forests be
directed to act in this role at such times as it is required.
That then is the basic framework of the plan.
In order to organize along the simple, direct lines
recommended, certain legislation, reorganization and
reassignment of jurisdiction will be required and these are
shown on Figure 13. Specifically, the following actions are
proposed for your consideration.
1. (a) Name the Forest Protection Service of the
Department of Lands and Forests as the
ultimate environmental protection agency.
(b) Provide the Forest Protection Service with an
expansion of the emergency powers it now has
for fire fighting to include containment and
cleanup of oil spills.
(c) Direct the service to utilize, during emergency
actions, an advisory group made up of the
operator responsible for the spill, a
representative from the Oil and Gas
Conservation Board, and, when applicable, a
representative of the Pipeline Division.
(d) Provide the Department with the necessary
funds for the purchase of specialized equipment
and supplies for strategic location in the
province and make provision for selected
members of the Department's staff to receive
specialized training.
2. Designate a single contact point for oil spill
emergency reporting, preferably the Oil and Gas
Conservation Board.
3. Designate the Oil and Gas Conservation Board as the
authority which engages all spill control and cleanup
services where the responsible operator fails to handle
his own spill. This should include engaging the Forest
Protection Service when needed. Further, the Oil and
Gas Conservation Board should be authorized to
assess costs of spill control and cleanup against the
offending operator in all situations, including those
where the Forest Protection Service has been
engaged.
-------
164 OIL SPILL PREVENTION ...
CONCLUSIONS & RECOMMENDATIONS
LANDS « FORESTS
ULTIMATE ENVIRONMENTAL
PROTECTION AGENCY
EXTENSION OF EMERGENCY
POWERS TO MAJOR OIL SPILLS
ADVISORS TO ON SITE
COMMANDERS
SINGLE COMMUNICATIONS POINT
LEOAL * FINANCIAL RESPONSIBILITY
DETAILED PLANNING
SECONDARY PROGRAMS
CURRENT TECHNOLOGY
RESEARCH
INDUSTRY STANDARDS
STATISTICAL ASSESSMENT
Figure 13
4. Regardless of the form that the contingency plan
ultimately takes, we strongly recommend that further
planning be done with the full involvement of
industry and to this end industry is prepared to make
available whatever manpower may be required.
I.P.A.C. and C.P.A. are currently preparing
communications to their memberships, appraising
them of the status of the provincial plan and pointing
out the urgent need for area plans to fit into the
proposed Provincial Plan. Work along this line will be
further accelerated in hazardous areas where the Oil
and Gas Conservation Regulations require the
preparation of contingency plans. The pioneer work
done by the Pembina Cooperative with the
Government's assistance, should greatly simplify the
formation of these other cooperatives.
5. Secondary programs which may evolve from the basic
plan might include:
(a) Maintenance of up-to-date information on new
developments in equipment, supplies and
techniques and their effectiveness in our
particular environment. Such information
would then guide the Department and Industry
in acquiring the appropriate equipment and
supplies.
(b) Information garnered in the foregoing could
point to areas where research is needed to fill
particular knowledge voids. This organization
could conceivably act as an agency for directing
or contracting for research and could control a
research budget.
(c) A set of preventive equipment design and
operating procedure standards could be
developed from oil spill experience. Such
standards could then either be recommended to
industry or used as a basis for amending
regulations.
(d) The Oil and Gas Conservation Board, since it
would be the recipient of all oil spill reports,
could maintain statistical records of spills. Such
records could facilitate more logical and
effective planning in all phases of preventive
and remedial standards.
-------
DEVELOPMENT OF AN AIR DELIVERABLE
ANTIPOLLUTION TRANSFER SYSTEM
INCLUDING THE DEVELOPMENT OF
OF AN OPTIMUM OIL STORAGE
CONTAINER
Commander R.J. Ketchel
United States Coast Guard
and
H.D. Smith
Goodyear Tire and Rubber Co,
ABSTRACT
During the past two years development of a special
purpose emergency tanker unloading system was accom-
plished. The Air Deliverable Transfer Pumping and Storage
System (ADAPTS) is now being provided for operational
use. This paper traces the development of the system from
inception to procurement specifications preparation. Prob-
lems encountered during the development effort are identi-
fied. Solutiom.and the rationale behind them, obtained to
overcome the technical and operational problems are dis-
cussed. Field test experience and performance data on the
ADAPTS system are presented.
INTRODUCTION
. Uncontrolled oil spills from grounded or damaged
tankers have in recent years caused large scale pollution of
ocean and shoreline areas. The U.S. Coast Guard has during
the past two years undertaken a three phase effort to com-
bat this threat to the environment. This program consists of
the development of equipment and techniques to reduce
the quantity of oil released, to control the spread of the
spilled oil and to remove the spilled oil. This paper will
describe the development of a self-contained system for the
emergency unloading of damaged tankers to reduce the
quantity of oil released.
This development has resulted in a unique Air Delivera-
ble Antipollution Transfer System (ADAPTS), consisting of
portable pumps, pump prime movers, temporary oil storage
containers, transfer piping, necessary fittings and tools and
requisite air delivery equipment. This system will be
pre'positioned at selected U.S. Coast Guard Air Stations and
will'be air-lifted to the scene of tankship casualties which
threaten an uncontrolled release of oil. Coincidentally,
Coast Guard Strike Force and civilian salvage personnel will
be helicopter delivered onboard the stricken vessel. The
system components will be delivered by parachute into the
water in close proximity to the stricken vessel Delivery of
these components onboard will be accomplished by
helicopter recovery of a lifting device and the helicopter
assisted retrieval of the remaining components by means of
the lifting device. Once onboard, system components will
be "assembled and operated by the Strike Force. Using the
portable ADAPTS pumps or the ship's installed pumps if
still operable, Strike Force personnel will transfer cargo oil
from the ship into temporary storage container. These
temporary storage containers, also parachute delivered, will
be towed to a safe anchorage by Coast Guard ships for later
disposal. The system has the capability of unloading 20,000
tons of cargo oil within 24 hours of a reported ship pollu-
tion incident. Deployment of the system is shown in the
artist's conception of Figure 1.
Development
Development of the system began in the Spring of
1968 with the inception of a concept for an emergency
*This paper was not presented during the conference.
165
-------
166 OIL SPILL PREVENTION
tanker unloading system. Background studies were com-
pleted and the basic system concept feasibility was es-
tablished. General system design criteria were established
and included that system development was to utilize
existing technology, materials and equipment to the great-
est extent possible. The system was to be complete and
self-contained and not require support from the distressed
ship. System components would include pump capacity,
pump power source, temporary storage containers, transfer
piping, necessary fittings and tools and the air delivery
equipment to deliver the packaged system. The components
nust be compatible for air delivery at the spill site by para-
;hute from the HC-130 Hercules aircraft within four hours
jf notification of a potential oil spill incident. The system
-nust perform in 40 mph winds and in 12 foot seas and be
:apable of transferring and storing 20,000 tons of crude oil
within a 20 hour period against a 60 foot head. A nominal
:rude oil having a viscosity of 100 ssu at 70°F and 340 ssu
it 40°F was designated as representing a typical average
:rude oil. The oil transfer pump must also pass through
Butterworth fittings.
A Request for Proposal for the Design and Development
of an Operational Prototype of this system was issued late
in 1968. The contract for this development effort was
awarded to Ocean Science and Engineering, Inc. of Bethes-
da, Maryland in the Spring of 1969. The total ADAPTS
prototype system was designed to consist of the following
three subsystems:
I. Air Delivery Subsystem
II. Transfer Pumping Subsystem
III. Temporary Storage Subsystem
Air Delivery Subsystem
The Air Delivery Subsystem consists of equipment for
the controlled delivery by parachute of system components
during deployment and a means to release parachutes and
component restraint on water impact. Pioneer Parachute
Co. Inc. was subcontracted for the design and manufacture
of the air delivery subsystem. Air delivery is to be effected
in two modules. One module consists of the system machin-
ery and includes the cargo oil transfer pump, the pump
Figure 1: Artist's Conception of ADAPTS in Use
-------
AIR DELIVERABLE TRANSFER SYSTEM
167
prime mover, a 55 gallon prime mover fuel supply and a
combination A-frame/tripod for recovery and movement of
the components. This equipment is air delivered by para-
chute from an altitude of 600 feet while packaged on a
8'xl2' air delivery platform. This air delivery is shown in
Figure 2. The module components are restrained by means
of a special container which is severed by pyrotechnic cut-
ters on water impact which allows the various components
to float free. This module weighs approximately 5000
pounds and uses a single vent controlled 100 foot diameter
G-l 1A parachute for recovery.
Strike Force who use the hand winch on the
A-frame/tripod to recover the machinery components. A
lightweight hydraulic powered winch is packaged with the
prime mover and is used to recover subsequent machinery
components. The winch is powered by the diesel prime
mover hydraulic power supply. Following recovery of all
equipment, the A-frame is converted into a tripod and used
to lower the submersible cargo oil pump into the hold of
the vessel.
A second module contains the temporary oil storage
container, 300 feet of 6 inch diameter transfer hose, infla-
tion and release equipment, a 40 pound anchor and two
crown recovery buoys. This 8'xl2' module is extracted
from the aircraft at an altitude of 800 feet by a 22 foot
diameter ring slot parachute. The container module is then
separated from the air delivery platform in mid-air by
means of static line cutter knives which sever the bindings
holding the module to the platform. This procedure was
incorporated to minimize water impact forces and to sim-
plify the deployment of the anchor and buoys in air.
Figure 2: Air Delivery of Pumping Subsystem
This main parachute is deployed by means of a static
line following extraction of the platform from the aircraft
by a 15 foot diameter ring slot parachute. Standard Air
Force low velocity extraction airdrop methods are used
therefore no new development was required. However, dur-
ing descent, a 22 pound ancrior and two crown or recovery
line buoys are deployed along separate trajectories. This is
done prior to splashdown to prevent fouling or tangling of
the crown and anchor lines which would prevent retrieval
of the anchor. This effort required special trajectory analy-
sis and the design of this unique mooring system package.
A .water actuated electrical circuit was also designed to re-
lease the parachute on water impact. The cargo oil transfer
pump is packaged in a flotation enclosure along with 160
feet of high pressure hydraulic hose. This pump, the diesel
prime mover packaged in a watertight case and the prime
mover fuel supply are tethered together and anchored. The
combination A-frame/lifting tripod with a recovery line and
buoy attached floats free and is ready for pick up by the
recovery helicopter. Figure 3 shows this recovery. This heli-
copter delivers the device to the Strike Force on the dis-
tressed vessel. The helicopter then attaches a messenger line
to the machinery crown line buoy and delivers it to the
Figure 3: Recovery of A-frame by Helicopter
Figure 4 shows this deployment. Trajectory analysis
played an important role in determining the feasibility of
this concept of air delivery. These studies included trajec-
tories and dynamics of the mooring system deployment
concept and water impact. Two 100 foot diameter G-l 1A
parachutes are deployed for recovery following platform
separation. On water impact the parachutes are released by
water actuated pyrotechnic release devices. The folded con-
tainer, restrained in a specially designed harness, is floating
and anchored. Styrofoam packaged within the container
-------
168 OIL SPILL PREVENTION .
causes the module to assume an upright attitude. Following
a 100 second delay the harness release devices are fired
which allow the container to unfold. A squib value is also
fired which releases nitrogen gas into the container's bow
buoyancy chamber. A recovery buoy is attached to the end
of the transfer hose which is retrieved by a helicopter. A
messenger line is attached to this hose end and the line
delivered to the Strike Force onboard the distressed vessel.
The hose end is then recovered by use of the hand or
hydraulic winch as necessary.
./nrv
Figure 4: Air Delivery of Storage Container Module
During concept development, an alternate approach for
storage container deployment was considered. This pro-
cedure called for platform extraction from the aircraft, con-
tainer module and platform separation and deployment of
the container in mid-air using a parachute to stabilize it as
necessary. This technique was rejected due to the potential
for damage to the container on impact and the complica-
tion of needed accessories.
Transfer Pumping Subsystem
The Transfer Pumping Subsystem power source
consists of a four cylinder, air cooled, 40 horsepower
die^el prime mover manufactured by Avco-Lycoming. This
standard engine has been slightly modified to incorporate a
manual hydraulic starter in place of the normal electric
starter and an external fuel tank in place of the integral fuel
tank. This integral fuel tank was converted into a hydraulic
oil reservoir for the hydraulic power transmission system.
The system hydraulic power is supplied by a Lucas IP-500
MAMS model variable displacement hydraulic pump. Ancil-
lary hydraulic system components are the hydraulic fluid
reservoir, a hydraulic prime pump, an Eastern Industries
Series 100 Model 107-41 supercharging pump, a 10 micron
hydraulic fluid filter and necessary system check and relief
valves. The prime mover and attached hydraulic power
supply, the system flowmeter readout device and the hy-
draulic winch are packaged in a watertight enclosure mea-
suring 40"x43"x48". This component weighs approxi-
mately 1150 pounds and is shown in Figure 5. The cargo oil
transfer pump is a two state centrifugal 10 inch type H
Figure 5: Diesel Prime Mover
submersible pump manufactured by the Byron Jackson
Pump Division of the Borg Warner Corporation. It is de-
signed to fit into a 12 inch diameter hatch so it can be
lowered into ships' tanks through standard Butterworth fit-
tings or deck plates. The pump is powered by a small
hydraulic motor which is directly coupled to the pump at
its lower end below the intake. The six inch diameter trans-
fer hose attaches to the pump discharge by means of a cam
locking quick acting fitting. The hydraulic supply and
return hoses are attached to the cargo pump and the
hydraulic power system by means of Snap-Tite quick acting
fittings. The oil transfer pump which weighs approximately
450 pounds is packaged with the two 80 foot lengths of
hydraulic hose in a rectangular aluminum structure mea-
suring 28"x28"x82". This structure contains polyurethane
foart] to provide flotation of the enclosure and pump when
they are deployed on the sea during recovery. This com-
plete package weighs 950 pounds and is shown in Figure 6.
This lightweight versitile pumping subsystem is capable of
transferring the design nominal crude oil at a rate of 1000
gallons per minute against a 60 foot head and through 300
feet of 6 inch diameter transfer hose. The difficult prob-
lems of delivering the necessary pumping power through a
lightweight unit and of providing design pumping capacity
in a relatively small, low powered pump were thus solved.
Temporary Storage Subsystem
The temporary storage subsystem consists of large 500
ton capacity flexible storage containers, flexible transfer
-------
AIR DELIVERABLE TRANSFER SYSTEM
169
hose and related equipment. The first system prototype
container developed by Uniroyal, Inc. consists of a mod-
ified pillow tank design incorporating a tapered bow which
is heavily reinforced to withstand and distribute towing
loads. The initial design called for the container to be
double ended for ease of deployment andrecovery, however,
model tests showed this configuration to be unstable in
yaw. Yaw stability was gained by removing the after taper.
Any tendency for the container to dive was corrected by
incorporating an inflatable buoyancy chamber on the bow
itself. These features proved to be very effective in achiev-
ing these goals as demonstrated through operational testing.
The difficult problem of designing and fabricating a tem-
porary storage container with strength to withstand towing
forces and forces of a 12 foot sea which was also light and
flexible to allow for air delivery by parachute had to be
solved. This problem was solved by conducting a model test
program that utilized scale models instrumented with strain
gauges, internal pressure transducers, and a towline tensio-
meter to determine the fabric stresses and towline loads
that would be experienced by the full scale prototype.
However, these tests gave inconclusive and inconsistent re-
sults due to the difficulty of scaling fabric thickness. The
difficulty of fabricating reliable strain gauges also contri-
buted to the problem. A significant result of the test pro-
gram was the determination that internal fluid surges set up
in resonance with the sea could cause excessive stresses in
the full scale prototype. The container design was based on
theoretical calculations which included the prediction of
maximum loads to 60,000 pounds. The container was de-
signed to withstand these loads with an appropriate safety
factor. To provide for the predicted higher stresses in the
stern area of the container this area of the container was
reinforced by the addition of a second fabric layer. An
additional model test program was also undertaken to
verify the results of the initial program. This second model
test utilized 1/15, 1/20, and 1/40 scale models instru-
mented to determine internal pressure, fabric stress and
towline tension. A graphical technique of data analysis was
used in which data from the several scale models were plot-
ted and compared on a common basis. The conclusions
reached were based on these graphical comparisons in an
effort to solve the problem of fabric thickness scaling. The
results of this test program indicated that the internal pres-
sures were directly related to the quasi static head and that
only insignificant internal fluid dynamic forces exist within
the container.
The prototype container was instrumented with inter-
nal and external pressure transducers and a towline tensio-
meter and tow tested at sea to verify the model test pred-
ictions. Tests were conducted in seas of six foot significant
wave height and at tow speeds to 6 knots. Tow loads were
measured which are approximately 50% greater than
predicted, however,these loads were observed to follow the
predicted load versus speed relationships. Significant inter-
nal fluid pressures were also measured. Maximum values of
approximately 10 psi gauge were measured. This indicates
that internal fluid dynamic forces are present. However,
fluid pressures of the same general magnitude were
measured by the externally mounted gauges. Maximum ex-
ternal pressures of approximately 13 psi gauge were mea-
sured with external-internal pressure differentials of
approximately 1-3 psi gauge noted. These test results are
presently being analyzed to explain the container internal
fluid dynamics. The results of the sea trials indicate that the
internal fluid surges are present and that the magnitude of
the internal pressures are intermediate between those pre-
dicted by the two model test programs.
Figure 7 shows this prototype container during sea
trials. Additional trials in seas of up to 12 foot significant
wave heights are planned to provide additional real world
data. Test data available indicate that this container is
suitable for towing to speeds of five knots in calm to
moderate seas and to speeds of four knots in moderate to
rough seas.
Figure 6: Oil Transfer Pump
A second prototype container, also fabricated by Uni-
royal, Inc., was of the same basic design as the first proto-
type. A tear problem in the tow point design of the first
prototype was corrected on this container along with the
addition of coloration of the external coating. These con-
tainers were fabricated of 13 oz. per sq. yard woven nylon
fabric which is coated internally and externally with a ni-
trile rubber compound. This prototype is 135'x35'x6' in
size when filled and has a capacity of 500 tons of oil. It
-------
170 OIL SPILL PREVENTION
weighs 8500 pounds when empty. When fully rigged for air
delivery this module has a weight of 13,000 pounds.
To ensure maximum success for the ADAPTS system a
parallel development of temporary storage containers was
undertaken. The Goodyear Tire and Rubber Co. was con-
tracted with for the development of a temporary storage
container of optimum shape, size and strength and to be
compatible with the ADAPTS system.
On June 1, 1970 Goodyear was awarded a contract by
the Coast Guard for the development of an optimized flexi-
ble storage container for the ADAPTS. The program in-
cluded a concept study; the fabrication and testing of one
fortieth and one eighth scale models: the design and
fabrication of a prototype container; and a packaging, de-
ployment and retrieval study.
The Concept Study consisted of a review.of hydro-
dynamic and structual theory for flexible towed bodies and
the choice of scale model size and shapes. From this study
evolved the six basic shapes for one fortieth scale model
testing shown in Figure 8. They included four cylindrical
bodies with both hemispherical and conical ends and had
fineness ratios (L/D) ranging from 9.31 to 23.5. One cylin-
drical body featured a ram inflated nose. Also included
were a tapered cylindrical body and a flat configuration
with pointed nose similar to the Uniroyal container shape.
Flow trippers, vortex generators and a drogue were pro-
vided to more closely simulate the prototype flow condi-
tions and to help stabilize the bodies where required. These
devices are illustrated by Figure 9.
MOD«L.»
i. C
«.*c
CYLINDRICAL
•ODIES
**C
5.
FLAT
IODY
6. C
TAPERED BODY
Figure 8: 1/40 Scale Models
FLOW TRIPPER
PLA*TIC TUBING
VORTEX .GENERATOR
-PLASTIC TUBIN«
VORTEX GENERATOR
-FABRIC SKIRT
Figure 7: Uniroyal, Inc. Prototype Oil Storage Container
PLASTIC com
Figure 9: Model Stabilization Devices
-------
AIR DELIVERABLE TRANSFER SYSTEM 171
The one fortieth scale model testing was conducted in
mid-July in the circulating channel at Naval Ships Research
and Development center (NSRDC). Over 250 runs were
made under the following conditions.
Variable
Velocity, Knpts
Full Scale
' 5
10
15
Tow Line Lengths, Feet 100
300
500
Percent Fill
95
100
1/40 Scale
0.8
1.6
2.4
2.5
7.5
12.5
95
100
This testing was conducted as a screening process and
performance was evaluated by visual observation during the
tests and later study of movie films taken during the tests.
Of the nine configurations tested, the tapered body
model with hemispherical ends was the most stable through
the range of test conditions. This model and a second
model having cylindrical body with conical nose and hemis-
pherical tail section were selected for the larger one eighth
scale model study. The latter shape was added since it could
be stabilized with a vortex generator and because of its
anticipated lower fabrication cost.
These two models were made of a square woven 4.5
ounce per square yard nylon cloth coated with poly-
urethane and utilized a closed cell vinyl foam along the top
interior surface for buoyancy. Both models were instru-
mented for internal pressures at forward, aft and midpoint
locations and for tow line tension. The tapered body also
had strain gauges on the skin at the forward, aft and mid-
point locations. Figure 10 shows the instrumented models.
The tests were conducted the week of August 7th at
NSRDC's deep water tow basin which, in addition to being
considerably larger than the circulating channel facility, has
the additional capability of wave making. These models, as
well as the earlier one fortieth scale models, were filled with
a water-alcohol solution having a specific gravity of 0.85.
One hundred and seventeen runs were made with combina-
tions of the following conditions.
Variable
Velocity, knots
Wave Height, feet
Wave Period, seconds
Full Scale
5
10
15
0
6
12
16
5.7
6.8
7.9
1/8 Scale
1.8
3.5
5.3
0
.75
1.5
2.0
2.0
2.4
2.8
Variable Full Scale 1/8 Scale
Percent Fill 95 95
100 100
105 105
Towline Lengths, feet 300 37.5
500 62.5
1000 125
TAPERED MODEL
SI. S2
r
i
p
/S.S" aA.
«•.*«,
SS.S*
-»-re
21' -T
s^. so,
59. 310
~~" PS-*- ^\
J
21.2." UA. —
CYLINDRICAL MODEL
27.2* OM
n n P9-PRESSURE TRANSDUCER
LOCATIONS
81 THRU 3K>- STRAIN CAUSE
LOCATIONS
Figure 10: 1/8 Scale Models
Based on the results of the tow tests, the tapered body
showed stable performance generally under all conditions
tested. The cylindrical model was stable for all conditions,
except with less than 100% fill. Towline tensions on
the tapered body was slightly higher than on the cylindrical
body indicating higher drag forces, which probably con-
tributed to its greater stability. Compared to the fuU scale
design limitation of 60,000 pounds at ten knots in twelve
foot seas, the model tests indicated 52,000 Ibs for the
tapered body and 45,000 pounds for the cylindrical con-
figuration.
After careful analysis of the strain gauge,pressure guage,
and towline data, it was concluded that only the towline
data were reliable. An attempt was made to correlate the
strain gage data with stresses calculated from the pressure
data by laboratory tensile testing of a section of fabric cut
from the tapered body with strain gauge intact, but it was
unsuccessful. It was also found that slight flexing of the
fabric produced large tension and compression readings of
the strain gauges.
In trying to determine the internal pressure upon
which hoop stress in the container is dependent, two dif-
ficulties were encountered. First, since the external pressure
-------
172 OIL SPILL PREVENTION
was not simultaneously measured, the differential pressure
acting on the container-could not be calculated. Second,
it was felt that the internal pressure measured contained a
velocity pressure element as well as the static pressure,
and since the velocity of the fluid inside the container was
not known the actual pressure contributing to'hoop stress
could not be determined. The only conclusion that could
be firmly drawn was that the hoop stress in the container
was less than those values calculated from the pressures
measured.
Based on test results, materials availability, weight, and
cost consideration, a decision was made to build the pro-
totype container in the tapered configuration using a square
woven fabric of twelve ounces per square yard having a
tensile of 650 pounds per inch. This decision was made
with the realization that the use of this weight fabric could
possibly restrict tow speeds and wave heights to less than
the design goal of ten knots in twelve foot waves. The
actual operational limitations were to be established by sea
trial of the prototpye container.
The prototype container was fabricated in Goodyear's
Phoenix facility and was shipped to Moorehead City, North
Carolina on January 7, 1971 for sea test. Figure 11 is a
sketch of this container showing some of its design features.
Its overall length is 173 feet five inches including hemis-
pherical ends.
fifteen foot tow harness of 2 5/8 inch diameter nylon rope.
A 40,000 pound fail safe link joins this rope to the 285
foot nylon tow rope of the same size. The other end of the
tow rope has a Danforth anchor attached. The anchor is
provided with a retrieval line and marker buoy. Figure 12
illustrates this assembly.
I igure 12: Prototype Container Forward Closure
Assembly
ravmG SKACKf 7
Figure 11: Sketch of Goodyear Tire and Rubber Company
Prototype Container
The diameter at the forward end is ten feet two inches
and it is fourteen feet two inches at the aft end. It has a
150,000 gallon capacity and weighs 2975 pounds without
hose and other accessories except fittings. The fabric is
coated with approximately .040 inch of polyurethane elas-
tomer. All seams are longitudinal and are both sewn and
cemented. A 25 inch diameter aluminum fitting is located
in the center of each domed end.
The forward closure plate is designed for a 60,000
pound tow load and contains the tow point for attaching a
Figure 13: Prototype Container Alt Closure Plate Assembly
The aft closure plate, as shown by the exploded view in
Figure 13, contains a fitting with a close coupled butterfly
valve to which a six inch diameter hose is attached. Three
lengths of hose totaling 300 feet is provided, A pair of
towing brackets with harness are also located on the aft
closure plate.
Reinforcing bands extending around the container are
located at approximately 43 foot intervals along its length.
Aluminum D-rings are fastened to these bands on either
side for attaching mooring lines and to assist in handling the
container.
-------
AIR DELIVERABLE TRAMSFER SYSTEM 173
Closed cell vinyl foam sections located on the interior
top surface of the tank provide buoyancy when it is empty.
A vent fitting and beacon are located on the top aft
end of the tank. For sea testing of the prototype, two
additional fittings were located in the sides of the tank for
mounting differential pressure transducer units and tabs
were provided on the top of the tank for mounting an
electronic package required for transmitting the pressure
data to the towing vessel.
The tank was packaged by folding onto an eight by ten
foot pallet along with hoses, lines, anchors, and other ac-
cessories. The total package weight was 4600 Ibs.
Deployment of the tank was accomplished by lifting
both ends with a crane and lowering into the water. It was
emptied and retrieved by lifting the nose end with a crane
and draining from the aft end. Additional lifting by the
D-rings along the body enables the container to be com-
pletely emptied and removed from the water. When dis-
charging oil instead of the fresh water as used in the proto-
type testing, a pump would be provided at the aft end to
transfer the oil ashore or to a barge.
Figure 14 shows this container during the sea trials.
Tow loads measured were in general agreement with those
predicted by the model test program. Internal fluid pressure
measurements showed that the pressures in the bow section
were greater than predicted while the pressures in other
container sections were in general agreement with the pre-
dictions of the model test program. These tests had
predicted a higher pressure area in the bow of the container
but not of the magnitude observed. Maximum pressures of
approximately 15 psi gauge were measured in this area with
maximum pressures of approximately 7 psi gauge measured
in other container sections. As noted during sea trials of the
Uniroyal, Inc. prototype, external pressure measurements
observed were of the same general magnitude as the internal
pressure at each location. Thus only low pressure dif-
ferentials are indicated across the container fabric. Maxi-
mum tow loads of approximately 20,000 pounds were
measured at a speed of 6 knots in 5 foot seas. This con-
tainer will be towable to speeds of 6 knots in calm to
moderate seas and to speeds of 5 knots in moderate to
rough seas. However, the full analysis of test results has not
been completed. Additional tow testing of this container is
also planned for the near future to provide additional
pressure and loading data for a full evaluation of opera-
tional performance and limitations.
Subsystem testing of components began in the Fall of
1969. These tests included air drop tests of dummy
modules to verify the air delivery concept for the oil
storage container module, pumping subsystem performance
tests, dockside drop tests of system modules to test impact
shock'resistance, retrieval tests and tow tests of the tem-
porary storage container. The first full system test was held
in lower Chesapeake Bay in February 1970.
This test held under calm conditions was followed by
three additional full system tests in the same location and
under the same general conditions. Figure 15 shows the
Figure 14: Goodyear Tire & Rubber Company
Prototype Container
machinery module being loaded onto a trailer for transfer
to the test aircraft. The oil storage container is shown
loaded in the aircraft in Figure 16. Use of the A-frame to
recover the system prime mover is shown in Figure 17.
Maximum wind velocity experienced during these tests was
20 knots with maximum seas to four feet observed. The
major problem experienced was difficulty with the water
actuated parachute and restraint release circuit. This prob-
lem was corrected and the system improved with the addi-
tion of redundant circuitry and pyrotechnics. Figure 18
shows the pumping subsystem on deck. A pumping sub-
system air drop test has been conducted under moderate to
heavy weather conditions of forty knot winds and six foot
seas. These tests have demonstrated the feasibility of the
-------
174 OIL SPILL PREVENTION. . .
system and have provided basic operating procedures. Com-
ponent reliability has also been tested while material
weakness identified and corrected. Additional rough-water
tests are planned for February 1971 to identify other prob-
lem areas and to determine system operational limitations.
Supplementary component testing has also been under-
taken. These tests will better determine the capability of
the pumping system under varying conditions, will establish
the reliability and endurance of the diesel prime mover
while operating at full load under extended periods of time
and provide the actual load trajectory for both the machin-
ery and storage container modules. This data will more
fully establish the operational capability of the system. Im-
proved utilization of the helicopter in system deployment
and retrieval is also being investigated. This will include
retrieval of system components by the HH-3F helicopter
with towing of components also envisioned. These
improved deployment techniques will be incorporated into
the system on completion of development tasks. Detailed
design and procurement specifications for an operational
system are now being prepared within the Coast Guard.
Procurement action for this system has been initiated with
contract award anticipated during the Summer of 1971.
SUMMARY
The development of the ADAPTS system completes
the first phase of the Coast Guard program to deal with the
problem of open sea oil spills. System feasibility has been
established and operational procedures developed through
subsystem and full system testing of an operational proto-
type. Additional operational testing is in progress to
establish operational limitations and to test component re-
liability. Procurement of the first operational system has
been initiated with contract award anticipated during the
Summer of 1971. This will result in the delivery of this first
operational system by the Summer of 1972.
Figure 15: Machinery Module Loading
-------
AIR DELIVERABLE TRANSFER SYSTEM 175
l;igurc 16: Oil Storage Container Module in Aircraft
-------
176 AIR DELIVERABLE TRANSFER SYSTEM
Figure 17: A-frame in Operation
-------
OIL SPILL PREVENTION ... 177
Figure 18: Pumping Subsystem on Deck
-------
A CHEMICAL TAGGING SYSTEM FOR USE
IN THE PREVENTION OF OIL SPILLS
R.A. Landowne and R.B. Wainright
American Cyanamid Company
Central Research Division
Stamford, Conn.
ABSTRACT
The bulk handling of various oils, especially crudes and
fuel oils, presents many chances for accidental spills. The
single most effective deterrent would be a tag in the oil
which would positively identify the party responsible for
spilled oil at the time of spillage. Crude petroleum from one
field can usually be distinguished from another by analy-
zing for trace constituents, such as heavy metals, but would
not discriminate among operators and carriers who handle
the same crude. Such discrimination is best achieved via
chemical tags blended into the oil at the time of change in
responsibility.
The most important property criteria for chemical tags
are discussed, including sensitivity, stability in the spill
environment, and non-interference with processing or use
of the oil. It is also necessary that the tags belong to a
system providing a large coding vocabulary. The Organic
Electrophore System is described, together with
preliminary findings which suggest it will satisfy the above
criteria. Ability to detect a tag at 1 ppb concentration in
crude oil using commercially available gas chromatographic
instrumentation is reported. Questions to be resolved
before the system can be brought to operational status are
discussed.
INTRODUCTION
Once oil has been spilled on surface waters, the ques-
tion of its effect on the environment is only one of degree.
Damage can be reduced through the use of more efficient
surveillance and cleanup methods, but never eliminated.
Thus, maximum attention must be focused on means of
preventing oil spills.
A convention adopted at the IMCO International Legal
Conference in November of 1969 covers civil liability for
the cost of oil cleanup, and holds owners and operators
liable for such costs up to a limit of $134 per gross re-
gistered ton, or $14 million, whichever is the lesser. This
magnitude of potential cost penalty is an enormous
incentive to the owners and operators to take all practical
steps to avoid spills. An additional giant step in this dir-
ection can be taken by extablishing a means of positively
identifying the source of pollutant oil from examination of
the oil subsequent to spillage. In waters carrying heavy
traffic, the evidence revealed in logs and other operating
records too frequently falls short of legal requirements, and
can at best indicate the most probably offender. Such is
particularly true in the case of. relatively small spills re-
sulting from various malpractices on the part of carriers.
Although small spills are individually of minor con-
sequence, collectively they have become a major environ-
mental problem. It is estimated by the Water Quality Office
of EPA that a total of 7,000 spills occur annually in U.S.
Waters.
It is desired, then, that a workable means be devised to
provide positive identification of the party responsible for
release of oil onto surface waters, with emphasis on oils
that have already entered the channels of commerce and are
being transported, transferred, or stored. To be workable,
the means must not be prohibitively costly, must not inter-
fere with further processing or use of the oil, and must
satisfy other criteria to be discussed below. For maximum
utility, the means must be adopted universally within a
specific region, or throughout the world.
Consideration of the source identification problem has
led some to propose the use of trace metals and other con-
stituents indigenous to petroleum as "fingerprints". While it
is true that oil from one producing field can usually be
distinguished from oil that is produced in another field, the
technique of "passive tagging" does not adequately dis-
criminate among the numerous operators or carriers who
might reasonably carry, transfer, or store crude oil and
refined oil products originating in the same production
field.
179
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180 OIL SPILL PREVENTION...
Active tagging of materials has long been practiced for
various purposes, including the policing of patent rights,
the identification of stolen goods, and the tracing of goods
at various stages in processing. One of the prime require-
ments for tags in all of these applications is long term
stability. Another is ability to distribute uniformly
throughout the goods, and a third is non-interference with
the ultimate use or function of the goods. Generally, the
tag is in the same physical state as the tagged article. Con-
ceivably, active tagging might be used either as a
self-sufficient system or as an adjunct to passive tagging.
One type of active tagging system that has been de-
veloped requires the use of radioactive materials. Another
depends on the use of metals or metal-organic compounds.
Neither seems well suited to the tagging of oils because of
the limitations they would impose on further processing or
use.
As far as oils are concerned, the extremely large
volume handled and the relatively low commercial value
(often about one cent per pound) demand a system of tag-.
ging agents that are detectable at very low concentration
levels, say, 1 ppm or below.
Description of System
Our work has centered around a metal-free,
non-radioactive system we call the Organic Electrophore
System, in which organic compounds known as
electrophores are utilized to provide the desired code
system. These electrophores, which possess a strong affinity
for capturing free electrons while in the gaseous state, can
furnish a very large coding vocabulary because:
• quite a few classes of chemical compounds
exhibit this property,
• within each class, variations in molecular weight
and molecular configuration produce discrete
code bits, and
• it is likely that workable combinations of code
bits from the same and different classes can be
put together.
The remarkable potential of the proposed system de-
pends on a combination of two laboratory analytical-
procedures, gas chromatography and electron capture de-
tection. The chromatography process makes a separation of
components based on their partitioning behavior in relation
to a liquid substrate material and an inert carrier gas. This
alone would not be useful for the present purpose. How-
ever, when the components separated by gas chromato-
graphy are subjected to electron capture spectrometry, an
additional distinction can be made with great sensitivity,
based on the level of affinity for electrons as measured in
an ionization chamber. The principle of this technique has
been described in the literature. (1,2)
The system of choice has outstanding features that
immediately suggest its worth. First, our investigations
show it to have great sensitivity, providing unequivocal dis-
crimination at a concentration of 50 ppb (parts per Wffib/z)
and lower. Second, it has the potential to be set up and
operated using presently known and readily available
organic chemicals. Third, the analytical methods require
little further development, and the apparatus is available
commercially. Finally, since we believe the Organic Electro-
phore System can be operated at a tag concentration level
of about 100 ppb, or below, it seems likely that the
materials costs will be a tiny fraction of the value of the
product. It is interesting to contemplate that, assuming 100
ppb of a $20/lb tagging agent, the largest tanker spill, which
cost in excess of $10 million to clean up, could have been
tagged with $370 worth of agent. Many of the compounds
that seem likely to be included are available commerically
at prices below the assumed figure.
Stability of the tags is an important concern. It should
be assured that the source of pollution can be identified
after a minimum of thirty days and preferably sixty days
exposure to ambient conditions, preceded by a much longer
period of time in storage. During ambient exposure, de-
gradation might occur by hydrolytic and oxidative pro-
cesses. Since the tags are organic compounds, uniformly
dispersed at very low concentration in the oil, they are not
prone to attack. Photodegradation would not occur because
of the aosorbance of naturally occurring aromatic com-
pounds in the oil in greater concentration (.001-1%) and
with much higher absorption coefficients (1033-105)than
any of the electrophores. The lack of solubility of the elect-
rophores would also prevent their leaching out into the
surrounding waters, nor would they be hydrolyzed at the
surface at any significant rate.
Degradation of oil by microorganism attack is said to
be up to 10 times as rapid as that by photo-enhanced
chemical oxidation (3*. Here again, eliminations of organic
tags because of differences in biodegradability is unlikely
considering the extreme dilutions to be used. The
electrophore system offers wide latitude in selection of
compounds having the required physical properties, and
which will "stay put" for the desired length of time, both
during storage and (after a spill) during exposure on the
surface waters.
The Organic Electrophore System is unlikely to suffer
from interference by the components normally found in
oils. There is an almost complete absence of compounds
having significant electron affinities in crude oils, as deter-
mined by analysis of Kuwait, southern Louisiana and Tia-
juana crudes, and Bunker C fuel oil. Even if an exceptional
case were discovered, it would be easy to select a code that
would avoid interference since the principle of analysis is
based on chromatographic fractionation combined with
electron capture detection. Attempts might be made to
"jam" the code by adding one or more active electrophores
to an oil slick. It would be so difficult to accomplish this
both uniformly and at the normal dilution level that the
jamming would be evident, and could be allowed for in the
analysis based on a standard kept on file after the tagging
operation.
Addition of the proposed tags to oil can be accom-
plished by means of known, proven procedures. It is
-------
CHEMICAL TAGGING SYSTEM...
envisioned that the tags would be stored as concentrates,
and metered into the oil during transfer of the oil. Com-
mercially available proportioning and metering equipment
would be used. Because of the very great dilution, a
two-stage operation is desirable in which the tag concen-
trate is first blended into a batch of the oil to be tagged,
after which the tagged blend is metered into a transfer line.
As an example, the concentration of tag might vary from
10% (100,000 ppm) in the concentrate to 100 ppm in the
intermediate blend to 0.1 ppm in the tagged oil.
(i)
(2)
(3)
(5)
(6)
- C - CH - CH -
€>-<<
(7) o - c ;c - o
^ • <
(8) -X
where X • haloatcm (chloro, brcno, iodo, fluoro)
(9) -SOs
Figure 1: Typical Electrophone Functional Groupings.
There are many classes of chemical compounds known
to have pronounced electron affinity. A partial listing of
the functional groupings that confer this property is shown
in Figure 1. The list expands greatly when one considers the
large number of molecules that are known to contain these
groupings. This is, naturally, advantage in that there is a
potentially large coding vocabulary.
Although some data are available from the literature
(4-8) an(j from general knowledge of experts in the field as
to which types of chemical compounds possess high elec-
tron affinity, many sensitivity values for high electron af-
finity compounds must still be determined under actual
analytical conditions. However, known likely candidates for
tagging agents are, for example, nitroalkanes and nitro-
phenyl derivatives, monochloroacetic acid, oxalacetic acid,
phthalic acid and cinnamic acid esters, benzoyl derivatives,
benzoquinone derivatives and haloalkane and halobenzene
derivatives.
Analysis Procedure
A small sample of the spilled oil, approximately 10 ml
eate, nitrotoluene or chloroacetanilide might be model
compounds found to be acceptable. Each is representative
of many additional compounds differing only in the size of
alkyl groups or alkyl substituted benzene groups. These re-
lated materials would then form a single coding group such
as the nitroalkyl benzenes or the dialkyl phthalates. Separa-
tion of the members of a homologous series is easily accom-
in size, would suffice. The actual measurement of electron
affinity values is carried out using a gas chromatograph with
an electron capture detector. Another detector, preferably
a flame ionization detector, is also required. The standard
procedure is to determine the sensitivity of the potential
tagging agent in terms of the smallest amount that can be
detected by the electron capture detector under suitable gas
chromatographic conditions. The flame detector is used to
determine the purity of the compound under test and to
more conveniently establish the conditions of analysis, such
as the proper chromatographic column and its operating
temperature and flow rate. When this is accomplished it is a
simple task to switch to the electron capture detector with-
out altering any other parameters, since the electronics for
the operation of both detectors are alike. (Even simultan-
eous operation of both detectors for monitoring the efflu-
ent from the same column is possible.) The sensitivity or
response of the detector to the test compound is deter-
mined by injecting as small an amount as possible into the
chromatograph. This is achieved by continually diluting a
solution of the material with a suitable solvent and noting
the reduction of the peak for the test compound. A value
for the minimum detectable amount, in grams, is then cal-
culated. Typical results ranged from 10-10 to 10"! 2 grams.
This value so determined is then used to compute the
concentration of the test compound in crude oil, or some
other oil, that can conveniently be detected by the same
analytical technique. When it is desired to measure the af-
finity of a test compound dissolved in an oil to be tagged,
the chromatography is performed with oil substituted for
the solvent.
Using the above general method, the utility of the Or-
ganic Electrophore System was tested using dibutyl maleate
as the electrophore. Three solutions were prepared as fol-
lows:
No. 1 2% Louisiana crude oil, 98% hexane,
and 50 ppm dibutyl maleate
No. 2 2% Louisiana crude oil, 98% hexane,
and 2 ppm dibutyl maleate
No. 3 100% Louisiana crude oil and 1 part
per billion of dibutyl mateate
When Solution No. 1 was compared against a blank con-
taining no electrophore, using gas chromatography
combined with a flame ionization detector, results were
identical, and the peak for dibutyl maleate could not be
distinguished. When the three solutions plus a blank were
processed using the same technique except for the substitu-
tion of an electron capture detector, the control sample
uielded essentially no peaks whatever, while the other sam-
ples showed distinct peaks about 13 minutes after sample
injection. Although the peak at 1 ppb concentration was
-------
182 Ol L SPILL PREVENTION ...
quite small, and required a lower attenuation setting for
readout, it was clearly distinguishable.
Discussion
When a model compound is found sufficiently sensi-
tive, additional members of the same homologous series
become promising candidates. For example, diethyl mal-
plished by gas chromatography so that each member of the
coding group is distinguishable at virtually the same analyti-
cal conditions used to test the model compound.
Many of the homologs in these classes of compounds
are available commercially. Even if exceptions should be
met, the commercial supply would not be a problem. Pre-
paration of homologs of satisfactory purity would be facile
since they are formed by adding side chains, and pure start-
ing reagents would be readily available. By this approach a
large total number of coding agents can be made available
that can be subgrouped according to their common electro-
phores and further broken down based upon molecular
weight, which determines gas chromatographic retention
time.
When the formation of isomers is possible, the very
difficult separation of these isomers is not required and can
be ignored. Actually, the chromatography will be run so as
not to distinguish between isomers, for example the alkyl
nitrobenzenes, but only to separate them according to
molecular weight. Usually, one or at most two isomers,
exceedingly difficult to resolve, predominate in such a mix-
ture and it would not be worth the effort to further extend
the size of the coding group by the complete separation of
all the possible isomers. Only when an isomer pair is as
easily resolved as is a homologous pair will both isomers be
used as individual coding agents. This is rarely the case,
however, except possibly for the t-butyl and isopropyl iso-
mers vs. their straight chain parent. The use of positional
isomers in the aromatic series as individual coding agents
would not be pursued because it is far more difficult to
elute them from the chromatograph individually than as a
single component.
It is essential to be able to use electrophores in combi-
nations in order to construct a large vocabulary. There
seems to be no question about combinations within the
same homologous series. However, one problem that might
be encountered is the accidental similarity in elution char-
acteristics of agents from two different chemical classes. If
this situation develops, it may be necessary to introduce a
second chromatographic procedure to fully decode a sam-
ple.
An unequivocal demonstration of stability would
appear to be crucial if evidence is to be utilized in legal
proceedings. Ultimately, each tagging agent, or combination
of agents must be tested under actual field conditions.
However, a laboratory program simulating exposure to the
natural environment may be satisfactory for screening these
compounds.
In conculsion, the Organic Electrophore System offers
promise as an active tagging system useful in the enforce-
ment against and prevention of oil spills. The extremely low
concentration of relatively stable yet harmless compounds,
their easy detection and wide variety for coding purposes
point up the desirability of putting such a system into wide-
spread use.
REFERENCES
1. Locklock I.E. and Lipsky, S.R., "Electron Affinity
Spectroscopy-A New Method for Identification of
Functional Groups in Chemical Compounds Separa-
ted by Gas Chromatography", JACS 82, 431 (1960).
2. Lovelock, J.E., "Affinity of Organic Compounds for
Free Electrons with Thermal Energy: Its Possible Sig-
nificance in Biology", Nature, 189, 729 (1961).
3. Dzyuban, I.N., Byull Inst. Biol. Vodokhran. Akad
SSSR.I, 11, (1958).
4. Landowne, R.A. and Kipsky, S.R., "Electron Capture
Spectrometry, and Adjunct to Gas Chromatography",
And. Chem., 34, 726, (1962).
5. Zielinski, W.L., Fishbein, L. and Thomas, R.O., "Re-
lationship of Structure to Sensitivity in Electron
Capture Analysis. III. Chloronitrobenzenes, Anilines
and Related Derivatives,"/. Chromat., 30, 77 (1967).
6. Landowne, R.A. and Lipsky, S.R., 'The Electron
Capture Spectorscopy of Haloacetates",^4nai Chem.,
35, 532(1963).
7. Landowne, R.A. and Lipsky, S.R., "High Sensitivity
Detection of Amino Acids by Gas Chromatography
and Electron Affinity Spectrometry", Nature, 199,
141 (1963).
8. Landowne, R.A., "Electron Affinity Applications in
Gas Chromatographic Analysis", Chem. Anal (Paris),
47,589(1965).
-------
CALIFORNIA CONTINGENCY PLAN FOR
OIL AND OTHER HAZARDOUS
MATERIAL SPILLS
by John F. Matthews, Jr.
California State Division of Oil and Gas
ABSTRACT
There is a dual approach in California for the
contingency plan for spills in that it must tie in with federal
plans plus suffice for the needs of heal areas within the
state. There are specifications in the plan for one state
authority to be in complete charge of the state's response.
In addition, the California approach also includes a State
Interagency Oil Spill Committee which draws its members
from the various affected state agencies. Members of
industry cooperatives, industry itself, and federal agencies
aid by adding input at committee meetings.
In organizing the state plan, three basic items have
been catalogued: the type of areas within the state, the
possible sources of pollution including probable quantities,
and the capability of the local areas. Types of areas include
the various shoreline configurations including offshore
islands and inland areas. Probable sources include tankers,
pipelines, and transportation systems. The capability of
local areas includes manpower, equipment, and dump sites;
the prime consideration, though, is the interest of the
governmental entities in these areas as lack of interest will
require increased involvement by the state government.
Overall regulations must be continually reviewed in
relation to the federal plans or local conditions and the
State Interagency Oil Spill Committee is used in California
for this purpose.
The state's basic consideration always is the protection
of its populace and natural resources.
INTRODUCTION
By definition contingency is a condition of being
subject to chance or accident. Any oil spill contingency
plan should meet the needs of a political subdivision to
abate, contain, and recover oil from any spills within its
jurisdiction.
The principal objective of the "California Oil Spill
Disaster Contingency Han" is to maintain an integrated and
effective state organization to combat major oil spills in and
about the State of California. Included are all major
elements, public and private, which have significant
resources and technical knowledge which may be required
or utilized in the public interest to combat such a spill.
Operations under the plan are directed toward the
preservation of the lives and health of the civil populace,
the protection of public and private property and the
preservation of natural resources.
The plan is designed to function independently or
effectively with either the U.S. Coast Guard or the
Environmental Protection Agency on a national, regional,
or subregional basis.
Definitions, Duties, and Organization
In order for a plan to function, the duties and
organization must be clearly defined. The California plan is
as follows:
ABBREVIATIONS
(National Plan)
EPA — Environmental Protection Agency
NRC — National Response Center
NRT - National Response Team
OSC — On-Scene Commander
OSOT - On-Scene Operations Team
ROT — Regional Operations Team
RRC — Regional Response Center
RRT — Regional Response Team
USCG - United States Coast Guard
(State Plan)
DOG - Division of Oil and Gas
OC - Operations Center
OSC - On-Scene Commander
183
-------
184
OIL SPILL PREVENTION .. .
RWQDB -.Regional Water Quality Control Board
SIOSC -State Interagency Oil Spill Committee
SLD - State Lands Division
SO A -State Operating Authority
SOT -State Operating Team
SST -State Support Team
SWRCB -State Water Resources Control Board
Disaster: A calamity from any cause, natural or
man-made, of such extent and severity that large numbers
of persons are imperiled and/or vast quantities of property
or natural resources are threatened, damaged, or destroyed.
Implicit in the term is the requirement to marshal and
employ the resources of numerous organizations, public
and private, civil and military, to minimize and recover
from its effects.
Oil: For the purposes hereof, this includes petroleum,
petroleum products, or sludge, oil refuse, and any other
oil-like substance which when spilled or discharged in large
quantities presents an imminent or immediate substantial
hazard to public health, safety or welfare, to natural
resources, or to public or private property.
Oil Spill Disaster: The discharge of large quantities of
oil which presents an imminent or immediate hazard to
public health, safety, or welfare, to natural resources, or to
public or private property, of a magnitude greater than the
mitigative capabilities of local organizations.
This term does not include small oil discharges which
cause only minor pollution of a local nature and which
constitute no major hazard. Such discharges are of interest
primarily from the law enforcement aspect by the local,
State, or Federal agency or agencies having jurisdiction.
Support: The furnishing of resources such
as: technical expertise including legal counsel, personnel,
equipment and material, and the delegation of the
authority necessary to direct the effective utilization
thereof.
On-Scene Commander (OSC): That person (or
organization) charged with the responsibility and delegated
commensurate authority for planning and directing the
overall operations of all organizations engaged in combating
an oil spill disaster; specific operations, however, will be
conducted under the supervision of the respective
organizations.
For spill disasters affecting navigable waters, the U.S.
Coast Guard will normally be the OSC. If a Regional
Operating Team is activated under the provisions of the
national contingency plan, the Regional Operating Team
will be advisory to OSC. Under the leadership of the OSC,
the State Operating Authority directs all state and local
government agency oil spill disaster operations.
The Environmental Protection Agency and the State
Operating Authority are joint On-Scene Commanders for
inland waters above the ebb and flow tide line. This line has
been defined for each river in the state.
For all other oil spill disasters, the State Operating
Authority shall be the OSC.
State Operating Authority (SOA): That person
charged with the responsibility and delegated
commensurate authority for planning and directing the
coordinated overall operations of all state and local
government agencies engaged in combating an oil spill
disaster, and to coordinate these operations with those of
federal agencies and private organizations. He shall be
delegated such authority as may be necessary to effectively
carry out this responsibility by, and shall serve at the
pleasure of, the State Support Team. He is also a member
of the Regional Team under the federal plan of the EPA or
USCG.
Either the SOA or one of his alternates shall be
available for immediate communications contact at all
times.
State Support Team (SST): This team consists of: the
Secretary for Resources, who shall be chairman; the
Secretary for Agriculture and Services; the Secretary for
Business and Transportation; the Secretary for Human
Relations; the Attorney General; the Director of the Office
of Emergency Services; State Adjutant General; and the
Director of the Department of Finance.
The State Support Team shall designate the SOA as
specified above, and shall provide him with such support
and authority as he may properly need to meet his
responsibilities.
State Operating Team (SOT): This on-scene team shall
provide technical advice, operating personnel and
equipment, and general counsel to the SOA during oil spill
disasters. The SOT will be composed of designated
representatives and alternates from the following agencies
or organizations:
Department of Conseivation
Division of Oil and Gas (2 members)
Division of State Lands (if required)
Department of Fish and Game
State Water Resources Control Board
Department of Parks and Recreation (if required)
Department of Public Health (if required)
Department of Public Works
Division of Highways
Office of Emergency Services
Office of the Attorney General
Local Government
Industry
SOT members will be appointed by their department
heads and must have a thorough knowledge of the resources
their organization can provide and commensurate authority
to place these resources at the disposal of the On-Scene
Commander in a timely manner. Team members will act as
liaison between the OSC and their respective agencies and
will arrange and expedite their agency's response to a
request for support by the OSC in such a manner as to
optimize the state's efforts in combating an oil spill.
-------
CALIFORNIA CONTINGENCY PLAN 185
The SOT shall meet annually in October (at the call of
the SOA) and/or at any other time at the request of the
SOA, for the purpose of discussing the past operations of
the team, changes in available resources, proposed changes
in the plan, and any other pertinent subject.
They shall also hold a formal critique, within 3 days of
its deactivation, of any incident during which the Team, or
any part thereof, was activated. A written report of
the results of this meeting shall be transmitted to the SOA
within 5 days and shall, if warranted, include specific
recommendations for revisions and additions to the oil spill
disaster contingency plan.
The Department of Conservation Public Information
Officer will be responsible for public information and
public relations services for OSC and furnishes progress
reports to the Governor's office.
The local government member shall be as specified by
the local contingency plan or as otherwise designated by
local authorities.
The industry member shall be designated by the
company involved or otherwise by the industry association
deemed most appropriate by the OSC. When the SOA is
also the On-Scene Commander, a representative of the
industry most closely affected by the oil spill (preferably
from the company involved, if any) shall also be a member
of the operational element of the SOT.
Such additional support from other state agencies as
the OSC may require shall be provided through the SST.
A representative of the Office of Emergency Services,
as a member of the SOT, shall work directly with the SOA
and provide for early alerting, other communications
services, and progress reports to the Governor's office.
State agency members of the SOT shall be designated
by their respective agency heads. The local government
member shall be as specified by the local authorities. The
industry member shall be designated by the company
involved or otherwise by the industry association deemed
most appropriate by the SOA.
Operations Center (OC): The Operations Center shall
be oil spill disaster headquarters for the SOA and the State
Operating Team. The SOA, in cooperation with the Office
of Emergency Services, shall select facilities as near as
practicable to the spill site considering such factors as
accessibility, communications facilities, location of
operational units, and safety.
The Department of Conservation shall be in charge of
establishing, equipping, and maintaining the operations
center. Other members of the SOT will furnish personnel to
staff the center as requested by the SOA.
The Operations Center may be relocated at any time
by the SOA after 24 hours notice (if possible) to all
organizations directly concerned.
State Interagency Oil Spill Committee (SIOSC): This
standing committee is hereby created and shall function
until dissolved by the State Support Team.
SIOSC shall be responsible for the following:
1. Establishing and maintaining liaison with federal, local,
and regional public and private organizations engaged in oil
pollution prevention and control;
2. Coordination between state agencies and other
organization in day-to-day procedures and practices relative
to the prevention and mitigation of pollution from oil
discharges;
3. Reviewing this plan at least once yearly to consider the
effect of newly enacted legislation, for consideration of
suggested amendments and additions, and for circulation of
recommendations for same to the parties hereto:
4. Reviewing contingency plans of other organizations; and
5. Recommending neccessary research, development and
testing by the appropriate organizations of materials,
equipment, and methods related to oil spill prevention and
control.
The SIOSC shall consist of the SOA, as chairman, and
as regular members, a representative and alternate from,
and appointed by the head of, each of the following
agencies: Department of Fish and Game, Department of
Conservation, Water Resources Control Board, and State
Lands Division. An Office of Emergency Services
representative shall participate in all contingency plan
considerations. In addition, the SOA may request other
agencies to be represented from time to time as
appropriate.
SIOSC shall meet annually in October at the call of the
chairman and at any other time at the request of the
chairman or of any two regular Committee members.
Operational Responsibilities
Local Authorities: Action to abate oil spills on
uplands or on nonnavigable inland waters, unless otherwise
governed by statute, is the primary responsibility of local
government. Local authorities must take all necessary
action to rescue and evacuate endangered citizens; secure,
contain, and abate the spill; alert the SOA and/or Coast
Guard; and enforce the security of the affected area.
Personnel from the industry involved in the spill can be
expected (or may be required by law) to exert all possible
efforts to mitigate the spill; local authorities may need to
support industry efforts with personnel and equipment,
particularly from fire departments and law enforcement
agencies. The existence of a local or regional oil spill
contingency plan will expedite operations. Establishment of
a central operations and communications center will greatly
aid coordination of the various operational elements which
may be employed, including state and federal agencies.
U.S. Coast Guard (USCG): In the event of oil spills on
navigable waters, including inland navigable waters to the
ebb and flow tide line, the Coast Guard has a primary
responsibility to take mitigative action in accordance with
standard operating procedures. Local authorities and the
SOA should be alerted and prepared to provide assistance as
requested. Local authorities should take all possible steps to
abate the effects of oil and oil-contaminated materials
which reach shore regardless of the origin of the spill.
-------
186 OIL SPILL PREVENTION ...
Federal^
Agency
URCB
DC
(DOC)
DFG
SLD
Other
State
Agency
1
Local
GoT't
Industry
Figure 1: U.S. Coast Guard as On-Scene Commander. (Spill
primarily on navigable waters of the state of California, national
contingency plan activated.)
Figure 2: U.S. Coast Guard as On-Scene Commander. (Spill
primarily on Federal navigable waters, national contingency plan
activated.)
Environmental Protection Agency (EPA): In event of
oil spills on inland waters above the ebb and flow tide line,
the EPA and the State Operating Authority have joint
responsibility to take mitigative action (Organizational
Chart 4).
State of California: Upon notification of an oil spill
"alerting procedures" the State Operating Authority will
ascertain all available facts regarding the spill by
communication with local authorities, state personnel on
the scene or in the area, the Coast Guard if involved, and by
any other available means. If it appears that state assistance
is or may become needed, he shall alert the State Operating
Team and the Chairman of the State Support Team and
proceed, or dispatch a representative, to the scene. The
SOA or his representative will then establish an on-scene
communications base, monitor operations at the spill site,
and furnish technical assistance from state agencies as
required.
At his discretion, the SOA may partially activate the
State Operating Team to act in an advisory capacity. If a
need for major state efforts is indicated, he shall, with the
approval of the State Support Team, declare the existence
of an "oil spill disaster" and fully activate the State
Operating Team. At this point, if the Coast Guard is not
already actively involved, the SOA becomes the On-Scene
Commander for all spill-related operations. Otherwise, he
shall direct state and local agency operations under the
leadership of the Coast Guard On-Scene Commander.
Depending upon the gravity of the situation, he may
recommend that the State Support Team request the
Governor to proclaim a State of Disaster.
Figure 3: Organization Charts (1) State Operating Team
Federal Regional Operations Team (ROT): If, in the
judgment of federal authorities, the magnitude of the spill
disaster exceeds the mitigative capabilities of the otherwise
available forces, or if the spill originates in an area under
federal jurisdiction, the "National Multi-Agency Oil and
Hazardous Materials Pollution Contingency Plan" will be
activated. A Regional Operations Team will be formed
which will be advisory to OSC. The SOA will function
directly under the On-Scene Commander under the U.S.
Coast Guard plan or as co-OSC under the EPA plan with
the continued responsibility of directing state and local
agency operations. Unless the spill is primarily on
state-owned lands, the industry representative, otherwise on
the State Operating Team, will at the request of the
On-Scene Commander function directly under him.
Alerting Procedures (see Figure 4)
In the event of a major oil spill or serious threat of
such spill in or about the state, those who first become
aware should immediately warn endangered persons in the
affected area and notify the local authorities, the Office of
Emergency Services, and/or the nearest U.S. Coast Guard
station.
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CALIFORNIA CONTINGENCY PLAN 187
ATELY
ENDANGERED
rTTT7ENR
H
Loc*l
/ {Local, state.
I or Citizen)
* Exceptions (Hlnor Spills)i
San Francisco Bay - notify
USCG for all spills
Long Beach-Los Angeles
Harbor-notify local Fish
and Game office - Phone:
213-1'53-77'H; AT3S t*7-
2253
(Spills from oil ncll oper-
ations should go to DOC as
primary agency)
San Diego Bay - notify UJCG or
WBCB
Figure 4: General Alerting Procedure Chart
If alerted first, local authorities should immediately
notify the Office of Emergency Services, Sacramento ATSS
No. (916) 485-6231 or 42M990 or Public No. (916)
445-6231 and, if the spill is in or near navigable waters, also
notify the nearest U.S. Coast Guard station. Local
authorities will disseminate additional warnings to the
general public in the area. The Office of Emergency
Services, however notified, will immediately alert the State
Operating Authority or one of his predesignated alternates,
in accordance with the standard operating procedure.
Spill Classification:
Oil spills will be classified into three general levels:
MINOR: Minimal spill (less than 1,000 gallons) which
has been abated and can easily be removed
and therefore, will not create a continuing
problem.
Operator to notify local office of the
Division of Oil and Gas immediately.* DOG
will notify headquarters, DFG, and RWQCB
(also SLD if offshore) during the next
regular office hours.
MODERATE: Spill, either abated or not abated, of
sufficient size (1,000 to 10,000 gallons) to
create damage but which is within the
capability of the operator to handle.
Operator to notify local DOG office
immediately.* DOG will immediately notify
headquarters, DFG (if spill would create a
problem for wildlife), WRCB, and SLD, if
offshore. (All agencies should supply DOG
with name and phone number of those to
notify in each area after office hours.)
MAJOR: Spill of a large magnitude (over 10,000
gallons) or of a continuing nature which
requires contributions from the state to aid
in the containment and recovery of the oil
and/or the activation of the SOT. Discharges
that occur in, or endanger critical water
areas, or are a threat to public health shall be
classified as major regardless of the volume.
Operator to notify DOG immediately.*
DOG to immediately notify OES and SOA.
SOA will notify SOT if necessary. SOA will
maintain current list of SOT members and
their phone numbers.
*DOG TELEPHONE NUMBERS:
Inglewood - (213) 678-7274
Santa Paula - (805) 525-6916
Santa Maria - (80S) 925-1658
Bakersfield - (805) 324-4515
Taft- (805)765-4138
Coalinga- (209)935-2941
Woodland- (209)662^683
Operations
Regardless of the makeup of the organization of the
type or location of the oil spill, certain basic operations will
need to be carried out. The employment of any or a
combination of the suggested measures will be undertaken
only after technical advice has been sought and all
considerations of safety, feasibility, availability of material
and equipment, side effects, and consequences have been
made. Some of the following operations may be conducted
a step at a time, but many will of necessity be carried out
simultaneously.
WARNINGS AND PATROLS
Issue warnings to threatened areas and establish spill
perimeter patrols. In the case of a major spill, new areas
may be imperiled from time to time as the oil spreads or
changes course.
OPERATIONS CENTER
The SOA shall select, establish, staff and equip an
Operations Center as a base of operations and
communications center. Other members of the SOT will
furnish personnel to augment the State as requested by the
SOA.
GATHER INFORMATION
Continuously gather the maximum information
concerning the spill: source and cause, present and
potential volumes and rates of discharge, chemical and
physical properties of the oil, and its present and probable
directions and rates of movement.
SECURE, CONTAIN AND ABATE SPILL
Formulate and execute plans to secure, contain, and
abate the spill.
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188 OIL SPILL PREVENTION...
Special Forces
and Projects
Federal. State &
Local Forces
__Labor Groups
Contractors
— Legal Advisor •—Etc.
Figure 5: SOA and EPA as Co-On-Scene Commanders. (Spill on
inland waters, not under USCG jurisdiction, national contingency
plan activated.)
Securing Source:
The more quickly and effectively the source is secured,
the less will be the magnitude of all other required
operations. This may require expert technical knowledge in
one or more fields such as engineering, ship salvage,
pipelines, oil well drilling or producing, refineries,
chemistry, geology, water quality, or demolition. It may
also require considerable special equipment and materials,
and trained crews. Industry representatives will normally
know where these can be obtained. In cases where the
source cannot be immediately secured, an alternative may
be to transfer pollutants from a damaged enclosure to other
facilities.
Containment and Removal:
The spilled oil generally should be contained in the
smallest possible area to reduce contamination and more
easily facilitate removal. In water areas, this will probably
involve the use of booms or caissons, and/or absorbents; on
land this may involve the use of levees, ditches, pits, and/or
absorbents'.
Gross quantities of the oil will need to be removed or
dispersed. On water, this may require skimming and/or
pumping equipment and storage vessels (these may require
towing); dispersent, solvent, chemicals, absorbents, or
biological cultures (these will all require application
equipment.) On land, this may require pumping, scraping,
earthmoving, steaming, or flushing equipment; solvent,
chemicals, or absorbents and raking or scooping equipment.
Burning may or may not be practical or acceptable either
on water or land areas, depending on the composition and
location of the material and local air pollution regulations.
Special attention should be given to operations in
critical areas such as lagoons and estuaries.
Disposal:
The oil and contaminated materials will require safe
disposal. Some liquids may be treated and reclaimed if
facilities are near at hand; some may require burial or
subsurface disposal with or without prior treatment.
Established disposal sites such as county or city dumps may
or may not accept contaminated material, particularly if it
is saturated or supersaturated; undersaturated material will
generally be more acceptable. Disposal and/or treatment
sites can become a severe problem. Disposal sites should be
predetermined by the State Water Resources Control
Board. Burning may or may not be practical or acceptable
depending on the composition and location of the material
and local air pollution regulations. On-site burial by discing
or other methods may or may not be feasible. Most disposal
methods will require hauling, loading, and other heavy
equipment. Care must be taken to avoid polluting
underground or surface water supplies.
Geanup and Rehabilitation:
The final operational phase will be cleanup and
rehabilitation of the affected area. Depending on the effects
of the spill, this may involve steam-cleaning, re-soiling,
re-vegetation, re-seeding oyster beds, leveling,
reconstruction of buildings and engineering works,
reestablishment of kelp beds, etc.
All the above operations will require logistic support
such as: provisions, materials and equipment,
transportation, loading, unloading, storage facilities, and
security provisions; communications; personnel, messing
and berthing facilities; semi-continuous surveillance of the
spill and its movements by aircraft, vehicles and/or boats;
sampling and analysis; equipment maintenance; weather
and sea forecasting for spill plotting and drift prediction;
medical services; collection and recordation of data
(including photography) on a day-to-day basis; legal
counsel; and administration, record keeping, funding and
accounting.
Volunteers (under study):
Bird Cleaning Stations (under study):
INFORMATION CENTER:
When a pollution incident occurs and the OSC is the
State Operating Authority, the Information Officer of the
Department of Conservation shall be notified immediately
and will act as Supervising Information Officer. He will
establish and direct an information center where he will
have easy access to the SOA and he shall take such other
-------
CALIFORNIA CONTINGENCY PLAN 189
steps as may be appropriate to coordinate public informa-
tion related to the incident.
The Supervising Information Officer, on behalf of the
SOA, may request appropriate professional and clerical
assistance from the member organizations of the State
Support Team and State Interagency Oil Spill Committee.
The Supervising Information Officer will contact press
offices of federal, state, and local governments, and other
concerned interests, as appropriate. The staff of the
information center shall compile a factual, detailed
chronology of the disaster, mitigative actions taken, and
related events and circumstances. He shall file daily
situation reports to higher authority and interested
agencies, and disseminate evaluated information to the
news media and the general public.
All news releases and any press contacts relating to the
incident will be made through the Supervising Information
Officer, acting on behalf of the SOA. He can be contacted
at (916) 445-3976.
EVALUATION TEAM:
In the judgment of the State Operating Authority, it
may be advisable to activate the Evaluation Team. The
purpose of the team will be to (1) evaluate the methods,
equipment, and materials used to contain and clean up the
spill and to assess damage to life, health, property, and
natural resources and (2) to assess damage to fish and
wildlife.
The team will consist of the Department of
Conservation and the Department of Fish and Game as
co-chairmen. Their primary responsibilities will be as in (1)
and (2) above respectively. Any state agency or members of
SIOSC that have the necessary expertise may be designated
members of the team for a particular spill.
DRILLS:
The SOA shall from time to time order simulated drills.
These may be with or without prior warning.
-------
THE ROLE OF THE OIL SPILL COOPERATIVE
IN THE OIL PRODUCING INDUSTRY
S. C. Mut
Eastern Region, North American Producing Division
Atlantic Richfield Company
ABSTRACT
When an oil spill occurs there is one question that is
paramount to all who have an interest in that very unhappy
occurrence. That question is.-"Does the spitter have the
capability to clean up the mess quickly and effectively?"
The answer is "Yes" if everything he needs is available to
him. If his requirements are to be readily available, it is
necessary that the capability to respond has been developed
before the spill occurs. This capability can be developed
either by the operator acting for himself alone or in a joint
effort with other members of industry in an oil spill
cooperative.
Oil spill cooperatives have been patterned after associa-
tions formed by oil companies to assist each other in the
event of fires, hurricanes, and other disasters. One of the
first active spill cooperatives was formed in Boston in 1967.
Reportedly, more than 60 such cooperatives are now active.
These are principally, however, harbor cooperatives involv-
ing refining, terminal, and transportation facilities. This
paper deals only with those cooperatives which involve oil
producing facilities with significant spill potential. At the
beginning of 1971, there were seven such cooperatives and
several others in various stages of formation. Their locations
range from the Gulf Coast to Alaska.
INTRODUCTION
What is an oil spill cooperative? It is simply an organized
approach involving several operators to cooperate in various
activities regarding oil spills. The role of the oil spill
cooperative can vary from that of mere lending of
equipment among the cooperating companies to a more
comprehensive activity involving planning, training, pur-
chase and maintenance of equipment, etc. The form of the
oil spill cooperative may be quite simple, as in the joint
operation, or it may be more complex, as in the non-profit
corporation. But regardless of organizational format, there
are some aspects of the overall situation where the
cooperative can and should perform a leading role and
other portions where its activities are necessarily limited.
To examine the role of the oil spill cooperative it is
necessary to keep in mind two distinct phases;preparation
before the spill and response in the event of a spill. The
cooperative's function in preparation is quite different from
its function in response.
The Preparatory Phase
The preparation phase involves (1) evaluation of the
elements or factors of the situation which will exist in the
event of a spill, (2) identification of the needs to be
fulfilled and (3) development of the plans and mechanisms
to meet those needs. To be adequately prepared for a spill,
it is necessary that these needs and requirements be
determined and that appropriate action be taken to meet
these needs before a spill occurs. Some of the factors to be
considered are the physical environment, the location and
nature of facilities with spill potential, the magnitude of
potential spills, and the laws affecting the operation of the
faculties. Next, with this information in hand, one must
decide on the control and cleanup techniques to be used,
the materials and equipment that will be required, and the
method of their use. The preparation phase is complete
only when these requirements are met by identifying
sources of supply, purchasing and stockpiling or otherwise
providing for the necessary equipment and material, train-
ing personnel, and by developing methods and plans for
combatting spills. In this preparation phase, the oil spill
cooperative is operating as a voluntary association with its
objectives and responsibilities defined by the members of
the cooperative.
The Response Phase
The response phase, which commences with the spill,
involves the actual utilization of the equipment, materials,
191
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192 OIL SPILL PREVENTION ...
expertise, personnel and plans developed or provided for
during the preparation phase to contain and clean up the
spill.
The response phase is different from the preparation
phase in that the responsibilities of the various parties
involved are not defined by the parties themselves, but
instead are clearly set out in the law. In the response phase,
then, the cooperative must adapt its activity so as to
conform to this situation.
A central consideration here is that the primary responsi-
bility for response in an oil spill situation clearly falls upon
the spilling party. Basic in the American system of law is
the concept that subject to applicable laws and to the rights
of other parties, an individual may decide upon his own
course of action, and in so doing be responsible for the
results of his decisions and actions. The operations of an oil
producer are subject to a fairly elaborate and complete set
of regulations, State or Federal, or both, but within these
regulations he operates the facility as he determines, enjoys
the benefits of the operation, and at the same time exposes
himself to any liabilities that may result. Thus he has the
primary responsibility for dealing with an oil spill.
However, should the spilling party be unable to dis-
charge his responsibilities to clean up a spill, or should there
occur a spill of unknown origin, the responsibility passes to
the Government. The Water Quality Improvement Act of
1970, which amended the Water Pollution Control Act of
1956, specifically places the duty upon the President to
clean up oil spills unless he determines the spilling party is
taking the necessary action. The direct responsibility for
this has been assigned to the On-Scene Commander as set
out in the National Oil and Hazardous Materials Pollution
Contingency Plan. Even where the Federal government does
clean up the spill, in most instances the spilling party is
liable for cleanup costs subject only to a rather large dollar
limitation. These aspects of the law must be fully taken
into account in devising plans for response to an oil spill,
and in defining the activities of the cooperative in the
response phase.
With this as background, let us first consider the
functions of the cooperative in the preparation phase.
Basically, there are five needs or requirements which must
be provided for during the preparation phase so that when
an oil spill occurs it may be contained and cleaned up as
effectively and as rapidly as possible. These are the
availability of (1) equipment and materials, (2) technical
expertise, (3) trained personnel and labor, (4) communica-
tion facilities, and finally (5) contingency plans. The
contingency plan must include not only the method for
containment and cleanup but also plans for liaison, dis-
semination of information and direction of the cleanup
activity.
In most instances there are four considerations that
apply to each of these needs or requirements. In order to
fulfill the needs one must determine first what is required
to get the job done; second, a source of supply; third, for
things which must be stockpiled, how and by whom
collection and maintenance will be accomplished; and
fourth, who will actually supervise and carry out the
operation. This is rather obvious when applied to things like
spill booms, barges and tugboats, but these same considera-
tions apply in one degree or another to technical expertise,
trained personnel and labor, communications facilities and
contingency plans.
This preparation activity can be and often is carried out
by the individual operators, but in many areas the
cooperative offers certain advantages. It is readily apparent
that there could be a substantial advantage in having the
cooperative make the initial surveys and studies since it
could have access to more information, and could bring a
wider diversity of expertise to bear. Then, too, a significant
economic advantage will be obtained when joint ownership
of equipment and materials is considered. Through joint
ownership of large expensive items of equipment and the
pooling of less expensive but necessary items, much
wasteful duplication will be avoided. Very often the total
amount of equipment and materials necessary to meet the
needs of a group of operators in a particular area is very
little more than that which would be considered necessary
by any one of the individual operators for his own use.
In many producing areas the requirement for the
cooperative to stockpile and maintain equipment and
materials is minimal, as there are usually available various
kinds of oil field service contractors with the ability to
furnish the necessary equipment, materials, manpower, and
know-how. The contractors' ability to supply manpower in
quantity is especially significant, as the operating com-
panies do not normally have sufficient personnel with the
appropriate skills, nor do the cooperatives, which normally
have only a small number of employees. Where such
contractors are involved in the overall plan the cooperative
can perform a valuable service by maintaining an up-to-date
knowledge of their capabilities, by setting up stand-by
arrangements with them, and developing standard agree-
ments and contracts which can be activated quickly.
So much for the role of the cooperative in the
preparation phase. While not as dramatic as the activities
which take place in the response phase, it is important
work, and crucial to the success of the containment and
cleanup operation.
Throughout the preparation phase, the cooperative has
the leading role, though the participating operators are
usually heavily involved as well. In the response phase, the
situation is different. As pointed out earlier, the burden and
responsibility for containing and cleaning up an oil spill
falls initially on the owner or operator. In the absence of
prompt and effective action on his part, the responsibility
passes to the On-Scene Commander. Neither of these
parties may abdicate this responsibility, nor may it be
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THE ROLE OF THE COOPERATIVE 193
assumed by the cooperative. The job of cleaning up the spill
must be done by one of these parties, either directly or
through a contractor working under that party's authority
and direction.
One of these parties, then, bears the responsibility for
bringing into action the plans, materials, equipment, con-
tractors and the like; that is, all the arrangements made or
set up by the cooperative during the preparation phase. The
cooperative can and will likely participate in mobilizing the
necessary resources and getting the operations started. It
may play a major or a minor role at this point, depending
on the wishes of the operator or the On-Scene Commander,
but it must not act independently or in place of them. Its
actions must be taken under the direction of one of these
parties, who then retains the overall responsibility.
SUMMARY
In summary then, it can readily be seen that the
cooperative may participate fully in the preparation phase
by conducting surveys and studies of the area of interest
and the spill potential, and by determining the type and
amount of equipment and material necessary and the
manpower and technical expertise needed. It may engage in
training programs of supervisory personnel to be utilized by
the individual companies in the event of a spill. The
cooperative can best, in concerted effort and through
contact with the proper governmental agencies, establish
communication channels and the method of liaison to be
utilized during a spill emergency. It may establish or
identify sources of labor, equipment and materials, and
may participate in drafting contracts or model forms. The
cooperative may participate in the ownership and mainte-
nance of equipment and materials. The cooperative may
also devise plans, methods, and techniques for coping with
spills and provide a means of communicating to the public
or the governmental agencies. In short, the cooperative may
and should, in the absence of some overriding reason,
maintain a role in those areas where either economies can
be gained or where consensus and/or concerted group
action is needed.
In the response to a spill, the cooperative should not
operate as an independent entity, but instead should
function under the direction and authority of the party
responsible for cleaning up the spill. It should make
available all its facilities, equipment, and expertise and lend
every assistance possible in mobilizing a swift and effective
response.
-------
OIL SPILL PREVENTION AND DETECTION
USING AN INSTRUMENTED SUBMERSIBLE
Wadsworth Owen,
VAST, Inc.
and
William Leaf,
Prototypes, Inc.
ABSTRACT
Submersible inspection of underwater pipes, storage
tanks, and drill rigs has often been limited to visual and
television techniques.
The advent of the small, inexpensive submersible of
limited depth capability makes it economically feasible to
propose the use of the submersible as a platform from
which to operate commercial ultrasonic testing apparatus.
The feasibility of these methods is discussed, and mounting
configurations and operational procedures are outlined.
Detection of seepage or breaks in pipes or containers is
also economically feasible through the use of fluorometric
techniques in conjunction with the small submersible.
Rhodamine dyes are used as a tracer in conjunction with
the submersible-mounted fluorometer to locate and mark
seepage or break locations. These non-toxic dyes can be
added in very small amounts to the fluid in the pipe or
containment vessel since the sensitivity of the fluorometric
detection system is on the order of one part in 1 ^ to one
part in 1(T^, depending on the type of instrument used,
the background fluorescence, and the material used as a
carrier for the dye.
Other applications for the use of submersible-mounted
fluorometers are: The inspection of ocean sewer outfall
pipes, diffusion of materials at depth, bottom current
detection, and detection of oil-filled power cable breaks.
Underwater inspection techniques are presently used to
assay the integrity of ships, pipelines, and underwater
storage tanks. It is expected that these techniques must be
expanded to meet the challenge of Man's increasing
underwater activities. Pipeline surveys have been success-
fully completed by submersibles 1, and divers are routinely
used for inspection tasks.
Underwater inspection for vessels of unusual size is
now recognized by the American Bureau of Shipping (ABS)
on an individual case basis. Each inspection must stand on
its own merit. The first ABS-approved underwater inspec-
tion was recently completed by divers of the California
Diving Company, Inc., at a reported considerable saving to
the drill rig owner. 2
Their size and attendant handling and operating cost
factors make the larger submersibles most suited for
pipeline inspection in deep water.. The smaller submersibles
such as Nekton, Guppy, and VAST Mk HI types are
economically suitable for ship, rig, and underwater storage
vessel inspection. They bridge the gap between the unassist-
ed diver and the more complex submersibles. They give the
diver greater endurance, temperature tolerance, and pay-
load, but reduce his flexibility and dexterity. The small
submersible must be fitted with instruments that either
extend the diver's ability or allow him to perform tasks not
suited to the unassisted diver.
We at VAST have been investigating the feasibility of
using submersible-mounted ultrasonic inspection apparatus
to inspect large tankers and underwater storage vessels. We
are also examining another technique, described in detail
later in the paper, which uses fluorescent tracer material in
conjunction with a sensitive instrument called a fluoro-
meter to trace seepage leaks or breaks in pipelines or in
underwater storage vessels.
The concept of using ultrasonic testing equipment for
the underwater inspection of supertankers evolved from a
knowledge of the practice of immersed testing of forgings
and wrought products by the manufacturing industry.3 At
first it was hoped that, following industrial practice, water
would serve as a coupling medium, and no contact would
have to be made with the steel of the ship. However,
experiments with the Krout-Kramer ultrasonic plate thick-
ness and fracture testing apparatus performed in our
195
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196 OIL SPILL PREVENTION ...
laboratory indicate that even in water physical contact
must be made between the probe and the metal or plate to
be tested. The narrow acoustic beam width of the ultra-
sonic test probe makes micrometer adjustment of the
angular orientation of the probe necessary in order to
receive the return signal. Although it may be possible
technically to develop plate thickness apparatus which does
not require such precise angular orientation, none is
presently under development. To inspect ships with any
ultrasonic apparatus now available, it is necessary to clean
the area before making contact with the probes. Divers now
use ultrasonic test equipment such as the Krout-Kramer
portable units with underwater probes or their equivalent.
As one would expect, practical experience indicates that
the coupling between the probe and the steel is better
underwater than in air. Thus for the present a submersible
using ultrasonic test equipment must be able to clean the
contact area, stop under the area, and position the probe
against the plate to be tested with a sufficiently precise
angular orientation to obtain a return signal.
The attached figures indicate the method of accomplishing
this using a submersible with a transparent dome on top.
Figure 1 shows the submersible fitted with fore and aft
dome guards and spring-mounted fracture and plate thick-
ness probes just forward of the dome. (Note: Two
transducers are usually used for the fracture test.) A brush
mounted on the forward dome guard is used to clean a
small area of the vessel at the sub approaches with a
positive angle of attack (up bubble). As the friction of the
brush against the plates of the vessel stops the submersible,
a small area is cleaned. Then a small amount of ballast is
blown from the aft ballast tank to rotate the
spring-mounted ultrasonic probes slowly against the bottom
of the ship (Figure 2). The readout instrument for the
ultrasonic apparatus can be used either for the fraction test
or the plate thickness test. Figure 2 shows the submarine
stopped with the probes resting against the plates of the
vessel.
The diver inside the submersible can make plate
thickness and fracture tests without returning to the
surface. He can illuminate and photograph areas of interest
under the ship and use any suitable equipment necessary to
the task. In this sense the diver has greater flexibility from
within the submersible since it can carry a variety of tools
for inspection tasks. It is also possible to take notes, make
drawings, and record vocal observations from within, which
adds to the utility of the submersible.
Regular inspection of pipelines, storage vessels, and
ships is an important tool in the prevention of accidental
discharge of liquid products into the marine environment.
The detection of breaks and seepage after they occur is
another aspect of pollution control which is expected to
become more important to industry in the future. The
difficulties and potential benefits involved in applying
water tracing techniques to submerged leak detection are
discussed in detail below.
Tracing the movements of a body of water, or other
liquid is a problem that confronts technical men of all
disciplines. The public health man wants to know the
flushing rate in sewage disposal areas. The marine biologist
is interested in the vertical and horizontal displacements of
the waters which transport marine growth. The physical
oceanographer is concerned with the flows and mixtures
that constantly change the nature of water bodies. And the
inspector of submerged oil containments has to discover the
sources of oil leakage.
In the past, many techniques have been devised and
applied to these studies. For instance, there is the direct
sampling method, where synoptic measurements of chemi-
cal contents are taken at a set of locations and are then
compared to evaluate changes in the water system; or floats
may be placed in the sea and then followed to learn the
paths of the currents or the up-and-down movement of a
layer of particular density. And, of course, many other
techniques which are well-known and accepted in a specific
field wfll occur to the reader.
One approach to the analysis of flow and mixing is to
add dye of an unmistakable color to the fluid system and to
trace the path taken by the stained patch as it is borne by
the stream. This Is a very old method and has been much
used to follow the course of underground water tables and
hidden streams. Fluorescein dye is usually employed
because of its characteristically intense yellow-green color.
BREAKAWAY VIEW
SHOWING READOUT
INSTRUMENT POSITION
Figure 1: Approach
Figure 2: Contact
-------
... AN INSTRUMENTED SUBMERSIBLE 197
Obviously, if this dye-tracing technique were to be
directly applied in populated areas, there would be a
well-justified public complaint, since enough dye to give a
visual indication would certainly be objected to by a public
aroused by the hazards of polluting additives. So, these
visual dye-tracing techniques may be employed only in
small-scale operations or where there will be sufficient
subsequent dilution to reduce the concentrations to less
than visible levels.
Within the past decade, a new method of dye detection
has gained favor among observers of fluid behavior. Not
dependent on visual characteristics, and considerably more
sensitive than former methods, the fluorometric technique
of dye concentration measurement makes possible the use
of smaller quantities of dye and the tracing of dilutions
smaller than one part in a billion, several orders of
magnitude below the threshold of visual detection. This
technique makes use of the fluorescent properties of certain
materials, their ability, when illuminated with a light of one
color, to emit light of another color. The most common
material for water tracing is rhodamine-B, an inexpensive,
non-toxic, organic dye, very commonly used in tinting
lipsticks and birthday cake candles. When this dye is
illuminated, or excited, by green light, it responds by
emitting an orange fluorescence. Petroleum products, them-
selves, are fluorescent, usually emitting a blue, or
blue-white, light.
Rhodamine is particularly attractive as a tracer since
there are practically no natural materials found in water
which exhibit the fluorescent characteristics mentioned
above. Of course there are natural fluorescent materials
found in water, mineral, animal, and vegetable matter; but,
fortunately, almost all of these emit light at much shorter
wavelengths (in the blues and greens), and require corre-
spondingly shorter excitation wavelengths, usually in the
ultraviolet region. Where industrial sewage wastes are
present, there is always the possibility that they contain
fluorescent contaminants, which will establish a back-
ground level that adds to the light from the glowing dye.
However, preliminary investigation of the water body
before the dye is added will reveal this source of error and
make possible a proper evaluation of it.
The economics of rhodamine-B are particularly attrac-
tive. The current price of this material, in thirty percent
solution is about $2.50 per pound. A pound of the material
will tag over a million cubic feet of water to the readily
detectable level of ten parts per billion.
The survey made by a submersible consists of a series
of "passes" close to the containment, or pipeline, while
observing the results of continuous sampling through the
fluorometer. If the tracer material remains visible, of
course, the instrument is redundant; but subsequent dilu-
tions of the fluorophore, and its dissemination over a large
area, eventually make it invisible; and only the fluorometer
can detect the tracer's presence.
The fluorometer, itself, which makes part-in-a-billion
readings possible, is a form of optical bridge with light
source, photodetector, specialized light filters, and pro-
vision for a through-flowing water sample. Many of the
instruments used in the field today are specially adapted
laboratory apparatus; they remain topside while a water
sample is pumped through long tubes; this can present
problems in under-way inspection. Another form of the
fluorometer is the in situ instrument which can be located
directly in the water body through the use of a towed
depressor, or it can be mounted on the hull of a
submersible. Fluorescence data are brought to the survey
vessel through a small electrical cable. The in situ form is
particularly useful in field work since its electrical power
requirements are small, and it is better able to withstand
rough handling shocks.
It would appear, then, that adding a fluorophore tag to
the contained petroleum will greatly facilitate the detection
and location of leakage. The approach may seem simple at
first blush, but there are a few obstacles to be overcome.
In using a submersible-mounted fluorometer to detect
a leak, one should be able to reconnoiter at some distance
and pick up a fluorescent signal. This means that the tracer
tag, if mixed with the petroleum in the pipeline or storage
vessel, must not be trapped in the oil and borne to the
surface with the escaping liquid; but it must, somehow,
leach out of the oil and dissolve in the surrounding water.
This requirement is not readily accomplished — finding a
fluorophore which readily dissolves in both oil and water —
and we know of no such material. It is possible that a
determined chemist's search would develop such a tag.
There is an alternate approach to the dual solubility
problem — one particularly applicable to submerged pipe-
line inspection. A quantity of rhodamine tracer is pumped
through the system concurrent with the inspection interval.
As the dye emerges from the leak, it mixes with the
surrounding water and forms a streaming cloud down-
stream, where it can be detected readily with the fluoro-
meter. The quantity and concentration of the dye pumped
depend on many factors such as the size and length of the
suspected section, the mixing and diffusing rates expected
in the ambient waters, and the probable downstream
distance between submersible and pipeline.
The suggestion has been made that containment
failures in underwater electrical power cables might be
detected in a very similar manner. Generally, these cables
are oil-filled, the oil being an excellent insulator. If a dye
could be added to the oil, it would leak into the
surrounding water in the event of a cable break, thus
facilitating fluorometric detection. This is a possibility
although, along with the problem of miscibility in both oil
and water, there is the difficulty of selecting a tag which
does not degrade the insulating effectiveness of the oil or of
the dielectric material of the cable. A thorough develop-
ment and proving program would be needed before
adopting such an approach.
-------
198 OIL SPILL PREVENTION ...
The economic potential of all methods of underwater
inspection increases as the size of ships, storage vessels, and
drill rigs increases. This is because the availability and
convenience of location of drydock facilities decreases as
vessel size increases. The larger the vessel, the greater the
loss due to its out-of-service time while it is transiting to or
in drydock. Thus, if drydock intervals could be extended
even one year through the use of underwater inspection
techniques, the anticipated cost saving appears to be great.
The cost of bringing the equipment to the ship will be
much less than the revenue lost while the ship is out of
service. Of course, this saving will not apply if the vessel can
be scheduled for dry docking at a regular port of call;
however, as the size of the vessel increases, this will become
more difficult. It is reasonably assured that the cost of an
underwater inspection is less than that of a drydock
inspection. A further saving may be accrued if the ship can
be inspected and/or cleaned while moored offshore to
discharge cargo, as this eliminates the out-of-service time.
The requirement to unload oil from an offshore mooring
will probably increase as the size and draft of the vessels
increase.
CONCLUSIONS:
In summary, we have investigated the feasibility of
underwater inspection using ultrasonic equipment mounted
on a small submersible and found it to be a practical and
economical procedure which has potential for even greater
cost saving when an apparatus is developed which elimi-
nates the need for direct contact. We have also studied the
feasibility of adapting water tracer techniques to under-
water leak and seepage detection and found that they have
a great potential usefulness. A submersible equipped with
an underwater fluorometer can now be used to test the
integrity of a water-filled pipeline. The major unsolved
problem is the one of dual solubilities, and it is this to
which we are now directing our attention.
REFERENCES
1. Stevens, R. C., "The lock-out submersible — a new
dimension for the working diver," Equipment for the
working diver, 1970 Symposium (February 24-25, 1970,
Columbus, Ohio), pp 403-424, Marine Technology Society,
Washington, D. C.
2. "How ABS inspects and certifies drilling rigs," Ocean
Industry, October 1969, page 29, Gulf Publishing Company,
Houston, Texas.
3. Hislop, J. D., "Flaw size evaluation in immersed
ultrasonic testing," Non-Destructive Testing, August 1969,
Vol. 2, No. 3, pp 183-192, Diffe Science and Technology
Publications, Ltd., Surrey, England.
-------
CAUSES OF OIL SPILLS FROM SHIPS
IN PORT
Captain W.H. Putman
The Resources Agency
California Department of Fish and Game
Long'Beach, California
ABSTRACT
This is a summary of causes of oil spills from ships in
the ports of Los Angeles/Long Beach during the period-
1962-1969. The data presented are a matter of record, and
believed to be statistically sound. These data should be
helpful to the Naval and Maritime communities as well as
those concerned with oil spill contingency plans.
Background
The California Department of Fish and Game began
investigating oil spills from merchant vessels in 1915 when
petroleum was added as a prohibitive substance to the
State's first water pollution statute enacted in 1875. This
criminal statute carries a minimum punishment of $100 and
a maximum penalty of $1000 and/or imprisonment in the
county jail not to exceed six months.
In January 1962, the Commander Naval Base Los
Angeles (COMNAVBASE-LOSA) requested the Department
to investigate oil spills from all Navy vessels in the two
ports to ascertain causes of Navy oil spills. "A report of our
findings was sent to the Navy in October 1970. The Depart-
ment was motivated to submit this report because of its
unique position of possessing data on both merchant and
Navy oil spills. It was utterly amazing, when one considered
the widely divergent purposes for which the ships were
built, to find the same dog "bit" all when it came to causes
of oil spills.
Procedures
Uniformed wardens of this Department responded to
all Navy spills as well as merchant spills. Our on-scene func-
tions were mainly two fold: (1) To contain and remove the
oil spill. Most spills were physically removed by sorbents
and skimming devices. Highly volatile liquids were agitated
and allowed to dissipate into the atmosphere. The use of
dispersants or sinking agents was prohibited. (2) To gather
evidence and data pertaining to the spill.
We investigated 443 merchant spills and 390 Navy
spills and mopped up some 13,000 barrels of oil during the
period 1962-1969 (Tables 1 and 2). Criminal complaints
were filed against masters and/or ship owners of merchant
vessels when evidence supported such a course of action.
No criminal suits were initiated for Navy spills; instead, our
investigation reports were sent to COMNAVBASE-LOSA
for military action.
Reports
A new investigative and reporting system was
developed during the period 1962-1969. The upper portion
of the form used in the reporting system provides space to
detail essential information an investigator must have to
prepare for trial. (Collected information also has been use-
ful in settling claims in admiralty.) The new aspect for oil
spill investigations is in the center portion of the form. Here
the causes of the oil spill are related to oil movement and to
point of emanation from the vessel. These are termed evolu-
tion and source, respectively. The report has space for nar-
ration which, if used properly, should permit the reporter
to expand upon other factors pertinent to the spill. The
general concept of the report was used by the Environ-
mental Protective Agency (formerly Federal Water Quality
Administration) and Coast Guard Headquarters in formu-
lating a national oil spill reporting system.
Problem Areas
There were two major problem areas that resulted in
oil spills in port: bilge evolution and fuel evolutions- which
included movements of ballast. Since these major problems
are so unrelated and solution to each calls for different
action, they are discussed separately.
199
-------
200 OIL SPILL PREVENTION...
Total Oil Spill Investigations from Ships in San Pedro Bay
1962-1969
Year
1962
1963
1964
1965
1966
1967
1968
1969
Total
Merchant
37
41
51
48
52
84
79
51
443
Navy
28
48
36
23
71
91
57
36
390
Total
65
89
87
71
123
175
136
87'
833
Table 1
Evolutions
Bilge Evolution
Of 833 investigations conducted by the Department,
bilge evolutions accounted for 249 oil spills (Navy 162 -
Merchant 87). These 249 spills represent only those related
to a known ship or source, since there were so many cases
of bilge oil drifting throughout the ports in the early and
middle 1960's that it was impossible to tally a count. Con-
sequently, the 249 spills do not accurately reflect the true
magnitude of the bilge problem. Although the frequency of
oil spills from bilge evolutions has become notably less in
the past two years, clandestine bilge pumping at night still
occurs.
Fuel Evolution
Merchant vessels accounted for 356 spills and Navy
ships were responsible for 228 spills related to fuel evolu-
tions. Some spills were not reported and the sources of
others could not be determined because of a lack of infor-
mation. Nevertheless, we do feel these 584 incidents repre-
sent over 95% of all the fuel evolution type oil spills. Ex-
cept in the rare instances of collision, hull leaks, or thermal
expansion of oil, ships did not spill oil until fuel or ballast
was moved by pumps within a system (Tables 3,4, and 5).
Total Barrels of
Merchant
Oil Spilled fran Ships in
1962-1969
t-^M^
f 37% 631
f Navy Merchant
31 72 / 5370
\ /[excluding
\ / collision]
\/ S
X /
Size Spill No. Spills
-1 to 1
2
3
4
5
6
7
8
10
15
20
25
30
50
60
100
150
200
300
350
1300
4500 [collision]
179
60
28
4
61
1
1
1
30
10
14
7
6
5
1
2
2
1
3
1
1
1
Total number barrels - 9870
San Pedro Bay
\
\
1
/
Navy
Size Spill
-1 to 1
2
3
4
5
6
7
8
10
15
20
25
30
40
45
50
60
65
75
100
150
200
250
300
350
No. Spills
173
66
32
16
36
2
1
1
13
3
7
5
Total nuifcer barrels - 3172
Table 2
Sources
When a spill occurred, oil escaped from some point
within the ship. These points of escapement fell into two
groups. The first group, such as vent tubes, sounding tubes,
overflow lines, and tank tops, was located above the water
line. The second group of sources was found below the
water line, and consisted of through-hull fittings connected
to bilge pumps, stripping pumps, main cargo pumps, general
service pumps, ballast pumps, and fuel transfer pumps
(Tables 3,4, and 5).
Causes
There were a number of different sources and causes of
spills from merchant freighters and tankships as well as
Navy vessels (Tables 3, 4, and 5). Freighters developed 12
different causes, tankships 18, and Navy vessels 21, with an
average of two causes per spill. There were many combina-
tions, but the most prevalent was a tank that was overfilled
because it was not sounded properly and oil escaped from a
vent tube or overflow line during bunkering operations.
CONCLUSIONS
The oily bilge and ballast problem will be with us until
facilities are made available to bring these liquids ashore for
-------
SPILLS FROM SHIPS IN PORT 201
accessing and disposal. Oil spills appear to originate from
ill types of ships regardless of their country of registry. As
i rule, we can conclude the country that has the most ships
Killing at a port will suffer, in a direct ratio, the highest
number of oil spills (Table 6).
Department investigations disclose that most ships and
their plumbing are built along a universal and classic design.
So when a spill related to fuel evolutions occurs, it does not
make any difference what flag she carries or what port she
enters, because the causes will be the same. Therefore, we
can expect these type oil spills until the Naval and Maritime
communities install self-contained overflow fuel systems
within their ships. Nearly all oil spills suffered during fuel
evolutions are directly related to personnel failure. We also
Ind the larger oil spills are usually attendant with a greater
degree of negligence.
In order to keep the "problem" of oil spills in its
iroper perspective, we feel it important to note the num-
jer and size of oil spills (Table 2).
Clean up operations of large oil spills resulting from
collisions or strandings have been adequately provided for
3y Federal and State contingency plans in California. We
relieve more research and development should be pointed
to the day by day removal of the chronic small oil spills.
FREIGHTERS
210 Spills
No. Evolutions No. Sources No. Causes
172 Bunkering 140 Vent tubes 176 Overfilled tanks
or none
5 Deballasting 13 Fuel manifolds 45 Top off at excessive
rate
2 Ballasting 6 General service pumps 33 Incorrect valve
alignment
1 Hydro test 4 Hull leaks 13 Did not consider list
or drag
2 Tank tops 9 Manifold problems
2 Fuel transfer pumps 7 Communication problems
2 Fuel hoses 4 Hull leaks
3 Valve obstructions
2 Use overflow tanks for
storage
2 Hose disconnects
1 Ruptured fuel hose
SOURCES AND CAUSES PER EVOLUTION FOR FREIGHTERS
BUNKERING - 172 Spills
Ho. Sources No. Causes
123 Vent tubes I*5 Overfilled tanks
33 Overflow lines 7* Soundings infrequent
or none
8 Fuel manifolds 42 Tol> o£f at excessive rate
4 Hull leaks 21 Incorrect valve alignment
2 Fuel hoses 11 Did not consider list or
drag
1 Fuel transfer pump 4 Hull leaks
2 Static pressure excessive
2 Use overflow tanks for
s tor age
2 Fuel hose disconnects
FUEL TRANSFER - 30 Spills
15 Vent tubes 28 Overfilled tanks
8 Fuel manifolds 9 Incorrect valve alignment
1 Tank top 3 Top off at excessive rate
1 General service pump 3 Valve obstruction
1 Fuel transfer pump 2 Did not consider list or
drag
1 No prior back suction
DEBALLASTING - 5 Spills
5 General service 5 Knowingly pump oily ballast
pumps overboard
BALLASTING - 2 Spills
2 Vent tubes 2 Overfilled tanks
2 Soundings infrequent or none
HYDRO TEST - 1 Spill
1 Fuel manifold 1 Ruptured fuel manifold
Table 3
TANK SHIPS
146 SPILLS
No. Evolutions No. Sources No. Causes
54 Load cargo 60 Tank tops 52 Overfilled tanks
40 Discharge 27 Main cargo 5L Incorrect valve
cargo pumps alignment
27 Bunkering 22 Hull leaks 34 Soundings In-
frequent or
none
9 Deballast 12 Stripping 22 Hull leaks
pumps
7 Ballast 6 Cargo hoses 5 6 ruptured cargo
hoses , 6 broken
chicksands , no
back flush prior
to deballasting
4 Fuel transfer 6 Chicksands 4 Did not con-
sider list or
drag
2 Cargo .transfer 5 Overflow 4 Top off at ex-
lines cessive rate
oily ballast
overboard
1 Light off boiler 1 Fuel transfer 3 Excessive dis-
pump charge rate
deballasting
Table 3: (cont. next col.)
Table 4: (cont. next page)
-------
202 Ol L SPILL PREVENTION ...
1 S tack 1 Conmunica t ion
problem
1 Collision 1 Ruptured riser
1 Light off
improperly
1 Thermal expan-
sion
1 Broken reach rod
1 Collision
SOURCES AND CAUSES PER EVOLUTION FOR TANK SHIPS
LOAD CARGO 48 SPILLS
No , Sources No . Causes
30 Tank tops 24 Overfilled tanks
14 Hull leaks 17 Sounding infre-
quent or none
3 Cargo hoses 15 Incorrect valve
alignments
3 Chicksands 14 Hull leaks
3 Main cargo pumps 3 Ruptured cargo hoses
1 Stripping pump 3 Broken Chicksands
1 Did not consider
list or drag
1 Thermal expansion
2 Skin valve open
DISCHARGE CARGO 34 SPILLS
9 Tank tops 24 Incorrect valve
alignment
9 Stripping pumps 8 Hull leaks
8 Main cargo pumps 3 Overfilled tanks
8 Hull leaks 3 Ruptured cargo hoses
BALLASTING 7 SPILLS
4 Main cargo pump 5 Ballasting without
prior back suction
1 Stripping pump 2 Incorrect valve
alignments
1 Fuel transpfer pump 1 Overfilled tank
1 Tank top
FUEL TRANSFER 4 SPILLS
1 Vent tubes 2 Overfilled tanks
1 Overflow lines 1 Top off at excess-
ive rate
1 Tank top 1 Soundings infre-
quent or none
1 Stripping pump 1 Incorrect valve
alignment
1 Skin valve open
CARGO TRANSFER 2 SPILLS
No . Sources No . Causes
1 Tank top 1 Overfilled tank
1 Main cargo pump 1 Soundings infre-
quent or none
1 Incorrect valve
alignment
HYDRO TEST 1 SPILL
1 Riser 1 Ruptured rise
LIGHT OFF BOILER 1 SPILL
1 Stack 1 Light off improperly
COLLISION 1 SPILL
1 Fuel storage tank 1 Collision
Table 4
DEBALLASTING 9 SPILLS
Main cargo pumps 4
Stripping ]
Knowingly pu*p
oily ballast over-
board
Excessive dis-
charge rate deball-
astlng
Incorrect valve
alignment
No.
78
12
6
3
2
1
1
SOURCES AND CAUSES PER EVOLUTION FOR
Bunkering - 103
Sources No .
Overflow lines 93
Vent tubes 37
Fueling hoses 33
Tank tops 19
Fuel transfer 19
pumps
Manifold 5
Rise 4
2
I
I
1
1
1
ALL NAVY SHIPS - 228 SPILLS
Spills
Causes
Overfilled tanks
Incorrect valve alignments
Sounding infrequent or
none
Top off at excessive
rate
Use overflow tanks for
storage
Did not consider list
or drag
Poorly lashed hoses
Ruptured hoses
Riser not capped
No blank flange on mani-
fold
Faulty valve
Poorly constructed tank
Cravited from shore
Table 4: (cent, next col.)
Table 5: (cont next page)
-------
SPILLS FROM SHIPS IN PORT 203
ALL NAVY SHIPS - 2E8 SPILLS
No. Evolutions Ho. Sources No. Causes
103 Bunkering 159 Overflow lines 191 Over-
filled
tank
88 Fuel transfer 16 Vent tubes 83 Sound-
Ings
infre-
quent
or none
12 Load cargo 16 Tank tops 77 Incor-
rect
valve
align-
ment
6 Offload fuel 10 Fuel hoses 33 Ose over-
flow
tanks
for stor-
age
4 Discharge cargo 6 Main cargo pumps 23 Top off
at ex-
cessive
rate
4 Deballast 6 Fuel transfer 8 Did not
pump consider
list or
drag
3 Pump to shore tank 4 Hull leaks 5 Communi-
cation
problem
2 Hull leaks 3 Bilge punps 5 Poorly
lashed
fuel
hoses
2 Hydro test 3 'Sludge tanks 4 Fuel hose
rupture
2 Collision 2 Manifolds 4 Hull
leaks
1 Ballast 1 Sounding tubes 2 Blow
down
from YO
1 Transfer cargo 1 Riser 2 Leaking
manifold
1 Stripping pumps 2 Faulty
valves
2 Static
pressure
excessive
1 Ballast
without
tank
back
suction
1 Poorly
cons truc-
ted tank
(sound-
Ing
tube)
I Obstruc-
ted
sounding
tube
1 Obstruc-
ted fuel
line
1 Dis-
placed
gasoline
header
1 Gravit
shore
1 Uncapped
riser
Fuel Transfer - 88
83 Overflow lines 84
3 Vent tubes 44
1 Sounding tubes 25
1 Bilge pump 14
I Main cargo pump 4
1 Fuel transfer pump 3
1 lianifold 1
1
1
1
CARGO LOADING - 12
8 Tank tops 8
2 Loading hose 6
1 Main cargo pump 4
1
1
Off Loading Fuel -
2 Fuel transfer 4
pumps
1 Vent tubes 2
1 Overflow lines 2
1 Tank tops
1 Bilge pumps
Deballasting - 4
2 Main cargo pump 2
1 Bilge pump 2
1 Fuel transfer 1
pump
Spills
Overfilled tanks
Sounding infrequent or
none
Incorrect valve alignments
Use overflow tanks for
storage
Did not consider list or
drag
Communication problem
cessive
Hose disconnect
Displaced gas header
Faulty valve
Obstructed sounding
tube
SPILLS
Overfilled tanks
merits
Soundings infrequent
or none *
Communication problem
Leaking manifold
6 Spills
Incorrect valve align-
ments
none
Overfilled tanks
Spills
Did not consider list
or drag
Coflnunication problem
ment
Hull Leaks -
Hydrostatic Test
2 Hoses 2
Collisions -
. Ballasting -
1 Main cargo pump 1
Transfer Fuel from Cargo
1 Tank top 1
1
2 Spills
s - 2 Spills
2 Spills
1 Spill
Take ballast without
prior back suction
to Bunker Tank - 1 Spill
Overfilled tank
Misaligned valve
Table 5
-------
204 OIL SPILL PREVENTION . . .
Total Number of Merchant Oil Spills per Flag
Excluding Bilge Pumping
Freighters
Flag
u. s.
Norway
England
Liberia
Sweden
Gernan
Greek
Panana
China
Japan
Denmark
Indonesia
Israel
Taiwan
Chili
Columbia
Korea
Netherlands
Nicaragua
Okinawa
Peru
Yugoslavia
So. Spills
88
21
18
16
IS
12
8
6
5
4
3
2
2
2
1
1
1
1
1
1
1
1
Tankships
Flag No. Spills
U. S. 75
Liberia 34
Norway 15
Panana 6
England 5
Italy 5
Finland 2
Sweden 2
Greek 1
Venezuela 1
Netherlands 1
Japan 1
Mexico 1
Table 6
-------
REMOVAL OF OIL FROM
SUNKEN TANKERS
Vincent C. Rose and Gerald C. Soltz
Department of Ocean Engineering
University of Rhode Island
Kingston, Rhode Island
ABSTRACT
A study was conducted on methods of eliminating the
oil threat from sunken tankers. The following possibilities
were considered: (1) destruction of the tanker and treating
the oil on the surface, (2) treating the oil in the tanker, and
(3) salvage of the oil. A thorough investigation of present
chemical, biological, natural degradation, and mechanical
methods of treating oilled to the conclusion that pumping
the oil from the tankers was the most economical and ef-
fective solution.
The final design was limited to ships laying in one
hundred to six hundred feet of water. It incorporates a
search operation to locate and buoy the tanker, a prelimi-
nary survey to determine the position and condition of the
ship and methods for penetrating the tanks and pumping
the oil from them. Necessary precautions are included to
prevent leakage of oil during the operation.
The oil would be removed by dynamically positioning
a converted tanker and a diver operation boat over the
sunken ship. A ten inch rubber hose would be lowered to
the sunken ship and secured to the hull with diver-operated
stud guns. Two penetrations would be made in each oil
tank to allow water in and oil out. The hull would be
penetrated by either a pneumatically operated circular saw
or a large reactionless hole punch. Once the holes were
made the oil would be pumped to the converted tanker for
transportation to a shore based processing plant. Final
cleanup would involve capping the open holes and innocu-
lating each tank with oil eating bacteria.
Removal of Oil From Sunken Tankers
A study was conducted on methods of eliminating the
oil pollution threat from sunken tankers by our graduate
level, advanced design, class during the spring of 1969.0)
Knowledge of the latest state of the art was provided
through guest lectures by outstanding scientists and
engineers from industry and government. These lectures in-
cluded information on tanker design, environmental effects
of oil spills, methods of cleaning up oil spills, methods of
preventing oil spills and a detailed assessment of the
on-going Santa Barbara incident.
All possible methods of oil pollution control were
studied and related to the problem. These methods can be
grouped into three general concepts: (1) release of oil from
the tanker with surface treatment, (2) treatment of the oil
in place, and (3) salvage of the oil.
The easiest method of removing the oil would be by
demolishing the ship. However, when the oil reached the
surface, it would still have to be treated by chemical, biolo-
gical or mechanical methods. Most chemicals were found to
be ineffective except under ideal conditions. In addition,
many chemicals are as harmful to the environment as the
oil. Biological methods are slow and require much addi-
tional research. Mechanical methods are generally restricted
to calm waters.
Treatment of the oil in place would involve injecting
the necessary biological or chemical agents into each tank.
Some methods of stirring would have to be provided to
insure complete reaction. At the present time no chemical
or biological agents have proven successful for this applica-
tion.
The third concept, salvage of the oil, would require a
mechanical system to bring the oil to the surface and trans-
fer it to a container. A positive displacement pump and
flexible hose was selected as the best means of handling the
oil. A converted T-2 tanker was chosen over rubber barges
and inflatable bags as the method of storage. A large num-
ber of bags would be required to contain the full cargo.
Selection of the final technique was based primarily on
effectiveness, risk of containment loss and state of the
art. The final design was limited to ships laying on one
205
-------
206 REMOVAL FROM SUNKEN TANKERS ...
hundred to six hundred feet of water. It incorporates a
search operation to locate and buoy the sunken tanker.Div-
ers would then be used to determine the position if the
ship and the condition of each tank, a stud gun with hollow
studs would be used to make sampling holes in each tank. A
sample would be extracted from each tank using a hollow
needle attached to an evacuated flask. Once the filled tanks
were located, a penetrating device would be attached to the
proper area of the hull. A hole would be made into the
tank. A flexible 10-inch hose would connect the device to a
pump which would remove all the oil into the storage con-
tainer. In order to keep the ship from collapsing, a second
hole would be made to allow water into the tank as the oil
is removed. After the oil is removed the device would be
removed and the hole sealed to prevent leakage of the re-
maining oil. Before sealing the tank would be innoculated
with oil-eating bacteria to reduce the residual oil in the
tank.
With the exception of the hull penetration device, the
components of the design are all currently available. Al-
though a number of methods were investigated, only two
methods of penetrating the hull appear feasible—a large
pneumatic punch and a circular saw.
Cutter mass 40 Ib
Counter Piston mass . 20 Ib
Time for cutter to hit hull 0.0045 sec.
Distance cutter moves 9.8 in.
Cutter velocity 5742.4n/
Distance counter piston aoves 5*5 ^n»
Counter piston velocity 719.6
Pressure in chasber at contact 625.5
Approximate weight 160 Ibs
Figure 1: Reactionless Punch
-------
OIL SPILL PREVENTION ... 207
The basic design of the punch is shown in Figure 1.
There are two masses, the cutter and the counter piston.
The principle is much like a recoilless rifle in that both
masses fire in opposite directions thus minimizing the barrel
recoil. The two masses are held together by a shear pin.
Compressed air is used to pressurize the space between the
two masses and thus provide the force to shear the pin. The
system was optimized for operation in 200 feet of water.
The complete design is shown in Figure 2. After the flange
has been connected to the hull, the joint is sealed with an
inflatable rubber gasket. When the system is fired, the
punch penetrates the hull and the counter piston moves
several inches back along the tube. A spring pulls the
. counter piston out of the way so that the passage to the
hose is clear. This permits the oil to be pumped out through
the tee connection. After the tanker is pumped out the
assembly can be separated from the flange by using the
exploding bolts. A cover plate can be placed over the hole
to contain the remaining oil water mixture.
Figure 2: Punch Assembly
A second smaller unit is used to permit water to re-
place the oil. A check valve is used to prevent the oil from
coming out of this opening.
The second design is an adaption of a commerically
available machine for tapping pressurized water and gas
lines. The major component of this hull penetrating as-
sembly, shown in Figure 3, are:
1. A special nipple with a gasketed flange for fastening
to the ship's hull.
2. A gate valve which attaches to the nipple.
3. A Mueller Company Model Cl 36 Drilling Machine.
(The Mueller Company, Decatur, Illinois.)
4. An air motor to power the drill.
A check valve would have to be added to the air motor
exhaust to prevent the chamber from filling with wwater.
After the hole is drilled, the cutter can be removed and
the oil pumped out of the tank. When all the oil has been
recovered, a "Completion Machine" can be used to insert a
plug in the nipple. This plug will seal the tank and permit
recovery of the valve. The cost of a complete assembly is
estimated at $4000. The equipment required is shown in
Table I.
Table I: Equipment Required for
Drilling Machine Assembly
ITEM
MUELLER CATALOG NO.
Drilling Machine Cl-36
Gate Valve 83953
Save-A-Valve Nipple H-17495
Drilling Machine
Adapter
Shell Cutter 33999
Cutter Hub 63978
Pilot Drill 64244
Completion Machine H-17345
Air Motor H-600
Modified for under-
water use
Modified with flange
and gasket
Replaced by quick
disconnect adapter
Modified for under-
water use
As originally conceived, the system was designed to
eliminate any future threat from the more than 100 tankers
sunk off the North Atlantic coast during World War II.
However, the total amount of oil remaining in these vessels
would at most be equivalent to only one super tanker. A
more practical use would be to pump out sections of
modern tankers that have recently sunk. For instance, the
stern section of the tanker that broke up and sunk off
Puerto Rico in 1969.
When the stern section of the Greek Tanker Arrow
sunk in 100 feet of water in Chedabucto Bay, Nova Scotia,
in February 1970, a 1.5 million gallons of bunker C fuel oil
threat was caused. Quite independent of our project, a new
technique was used to recover the oil by means of a drilling
machine. The technique was similar to the design described
above with the exception that a steam line was added to
heat the oil. When the air lines froze, the air motor was
replaced with a hydraulic motor and the tanker was
successfully pumped out.
It is suggested that these techniques should be further
refined. A number of penetrating devices should be built
and stored for emergency use at one or more central oil
spill equipment depots. The lightweight nature of the De-
vice would permit easy air shipment.
REFERENCE
1. VanRyzin, etl al., "Elimination of Oil Pollution
from Sunken Tankers," Department of Ocean Engineering,
University of Rhode Island, Kingston, Rhode Island, May
1969.
-------
208 REMOVAL FROM SUNKEN TANKERS .. .
Figure 3: Circular Saw Assembly
-------
OIL VERSUS OTHER HAZARDOUS
SUBSTANCES
by C. Hugh Thompson
Water Quality Office
Environmental Protection Agency
ABSTRACT
The Water Quality Improvement Act of 1970 requires
that pollution by oil and hazardous substances other than
oil be addressed by the Federal Government. By satisfying
the several provisions of the Law an overlap occurs when
dealing with establishing the difference between oil and
hazardous substances.
To satisfy in part the provisions of sections 11 and 12
of the Law, regulations are to be promulgated for oil and
hazardous substances. A rationale is presented in this paper
which, when combined with the regulations, should allow
industry and government to proceed in this area without
detailed lists of materials being required. The rationale is
based upon a material being petroleum derived or
extractable or having defined chemical structure.
INTRODUCTION
The passage of the Water Quality Improvement Act of
1970 on April 3, 1970 clearly emphasized the problem of
discharges of oil and hazardous substances into our nation's
waters. This emphasis was illustrated in sections 11 and 12
of the Law (Public Law 91-224). Section 11 and section 12
of the Law require the President to designate "harmful
quantities of oil" and "hazardous substances" other than
ofl. Some of the provisions of section 11 of the Law call
for: establishing financial responsibility of potential oil
dischargers; administering sanction against oil dischargers
who fail to give notice or willfully discharge; making oil
dischargers liable for costs of cleanup regardless if they or
the Federal Government implement the cleanup. The
provisions of section 12 of the Law are not currently
defined in the detail that section 11 provisions are. There
are no enforcement provisions in section 12 to back
requests that notice be given of discharges of hazardous
substances nor is liability or financial responsibility
established for potential dischargers of hazardous
substances.
The large disparity between the economic sanctions
against dischargers of oil versus dischargers of hazardous
substances makes it important that government and
industry understand and agree upon a clear dividing line
between oil and hazardous substances. This paper will
demonstrate a rationale that may be used for the purposes
of the Law to discriminate between oil and hazardous
substances. Refinement of this rationale must recognize the
provisions of the Law which designate harmful quantities of
oil and hazardous substances. The Law lacks a clear
definition of what is considered a hazardous substance. A
non-oil material is not, by definition, a hazardous
substance, but rather a material that may be considered as a
candidate to be designated a hazardous substance.
Several laws have been enacted in which attempts have
been made to define oil. Some of these laws and definitions
are as follows:
Oil Pollution Act of 1924
"the term 'oil' means oil of any kind or in any form
including fuel oil, oil sludge, and oil refuse";
Oil Pollution Act of 1961
"the term 'oil' means persistent oils, such as crude oil,
fuel oil, heavy diesel oil, and lubricating oil. For the
purpose of this legislation, the oil in an oily mixture
of less than one hundred part of oil in one million
parts of mixture, shall not be deemed to foul the
surface of the sea";
"the term 'heavy diesel oil' means marine diesel oil,
other than those distillates of which more than 50
percentum, by volume distills at a temperature not
exceeding three hundred and forty degrees centigrade
when tested by the American Society for the Testing
of Materials Standard Method D.I58/53";
209
-------
210 OIL SPILL PREVENTION . . .
Oil Pollution Act of1961, as Amended
. . . change Standard Method D.158/53 to
D.86/59 ...
"the term 'oil' means crude oil, fuel oil, heavy diesel
oil, and lubricating oil, and 'oily' shall be construed
accordingly. An 'oily mixture' means a mixture with
an oil content of one hundred parts or more in one
million parts of mixture";
Clean Water Restoration Act of 1966
" 'oil' means oil of any kind or in any form, including
fuel oil, sludge, and oil refuse";
International Convention Relating to Intervention on
the High Seas in Cases of Oil Pollution Casualties
(1969)
" 'oil' means crude oil, fuel oil, diesel oil and
lubricating oil";
International Convention on Civil Liability for Oil
Pollution Damage (1969)
" 'oil' means any persistent oil such as crude oil, fuel
oil, heavy diesel oil, lubricating oil and whale oil,
whether carried on board a ship as cargo or in the
bunkers of such a ship".
Water Quality Improvement Act of 1970
" 'oil' means oil of any kind or in any form, including
but not limited to, petroleum, fuel oil, sludge, oil
refuse, and oil mixed with wastes other than dredged
spofl".
However, with the exception of the Water Quality
Improvement Act of 1970, none of the above definitions
were developed with a parallel intent expressed for
hazardous substances.
Congress asked the President to designate "... as
hazardous substances, other than ofl as defined in section
11 of this Act (PL 91-224), such elements and compounds
which, when discharged in any quantity into or upon the
navigable waters of the United States or adjoining
shorelines or the waters of the contiguous zone, present an
imminent and substantial danger to the public health or
welfare, including, but not limited to, fish, shellfish,
wildlife, shorelines, and beaches ...". The apparent overlap
and breadth of the problem poses a complicated situation.
Concern and confusion was expressed by industry relative
to what was the basis of decision to determine if a material
was an oil or whether it was a hazardous substance/') A
general rule based upon established technical considerations
would be preferred, but an incremental decision sequence
that demonstrates the factors to be considered may be
more appropriate.
Technical definitions of oil may be found in several
texts and handbooks. However, these definitions were
usually developed for purposes 'other than water quality
management and therefore may or may not stress
properties that are significant for oil discharged into or
upon the navigable waters of the United States.
Defining authorities'^) note that any liquid of relatively
high viscosity which has a slippery feel is likely to be called
an oil. Oily matter is defined by the American Society for
the Testing of Materials (Dl340-60) as hydrocarbons,
hydrocarbon derivatives, and all liquid or unctuous
substances that have boiling points of 90°C or above and
are extractable from water at pH 5.0 or lower using
benzene [chloroform or carbon tetrachloride] asasolvent.(^)
The major catagories of oil are recognized^s (a) petroleum
or mineral or hydrocarbon oils derived from crude
petroleum, (b) fatty oils which are glycerol esters derived
from vegetable or animal fats or similar materials, and (c)
essential oils derived from plants, usually not esters but
more often terpene hydrocarbons. The determination of
oils and grease for water quality management has been
suggestedin Standard Methods^) to involve extraction using
various solvents such as petroleum ether or
trichlorotrifluroethane and represents dissolved or
emulsified oil or grease found in water. Kerosene and
gasoline cannot be determined without modification of the
procedure. Part 17 and part 18 of the American Society for
the Testing of Materials Standards(^)list criteria for crude oil;
diesel fuel oil, fuel oil; gas oils; illuminating oils, lubricants,
mineral oil, plant spray oils; rubber extender oils;
transformer oils and turbine oils.
Under the provision of the Law (PL 91-224), "oil of
any kind or in any form" is to be addressed. This may be
interpreted to mean coconut ofl, shale ofl, olive ofl, mineral
ofl, linseed oil, peanut ofl, fats, greases, and petroleum
derived ofls. Basic recommendation of the National
Technical Advisory Committee note that waters, both fresh
and salt, should be free from "floating debris, oil, scum and
other matter."(^) The considerations of sources of oil
included/**) bilge and ballast waters from ships, oil refinery
wastes, industrial plant wastes such as oil, grease, and fats
from the lubrication of machinery, reduction works, plants
manufacturing hydrogenated glycerides, free fatty acids,
and glycerine, rolling mills, county drains, storm-water
overflows, gasoline filling stations and bulk stations".
However, interpretation of a harmful quantity of oil was
based primarily upon the petroleum derived oils as
suggested by the National Technical Advisory CommitteeC**)
Chemical tests(7)advise that liquid fats are called oils but
these glycerides of animal and vegetable origin should not
be confused with lubricating oils, which are hydrocarbons.
This distinction is the basis of the problem in that Congress
has required that the public health or welfare be protected
from "ofl of any kind."
Hazardous substances may be designated under the
provisions of section 12 to include inherently hazardous
and other hazardous substances. This designation would be
responsive to the broad categories of materials that may be
spilled into the navigable waters of the United States.
Materials may be designated as inherently hazardous
include toxic metals and anions, Class A, B, C poisons
covered by Department of Transportation regulations,
economic poisons and radioactive materials. Other
hazardous substances could include a very braod based
-------
OIL vs OTHER HAZARDOUS SUBSTANCES 211
group of acids, anhydrides, oxides, peroxides, bases,
alkalies, elements and salts, halocarbons, alcohols,
aldehydes and ketones, esters, ethers, aromatics, nitrogen
containing compounds, sulfer containing compounds,
miscellaneous compounds and hydrocarbons other than oil.
Water quality criteria indicating the extent of imminent and
substantial danger to the public health or welfare are to be
used to assess the severity of the discharge.
The Rationale for Determination
The rationale used to distinguish between oil and
hazardous substances must respond to the requirements of
Congress and be as inclusive under the term oil as
technically feasible. Most oils are complex mixtures of
elements and compounds that are described by specific
gravity, melting point, viscosity, boiling point, flash point,
bromine number, iodine number, saponification number,
cloud and pour points, trace impurity analysis, and
quantity of solvent extractable materials, as well as others.
The chemical structure of most oils is difficult to determine
and is not used to describe the materials' behavior.
Elemental analysis or assay of certain chemical radicals in
an oil may be determined to gain further insight into the
expected physical, chemical or biological behavior of the
material, but the actual chemical structure of the oil is not
defined and used.
Figure 1 illustrates the decision points that may be
used to discriminate between an "... oil of any kind in any
form..." and a material which may be a hazardous
substance. This distinction implies that a material
determined not to be an oil need not be a hazardous
substance. This flexibility must be provided since all non-oil
materials are not necessarily hazardous substances.
The rationale involved with Figure 1, which attempts
to distinguish between oil and potential hazardous
substances, requires at least three questions to be answered
for most materials. Is the material in question derived from
a petroleum or petroleum-like source? If the material is
petroleum derived is the chemical structure defined? If the
chemical structure is defined for this petroleum derived
material, then it is a possible candidate for designation as a
hazardous substance. If the chemical structure is not
defined for this petroleum derived material, then it is an oil
and can occur in any form.
VM <*• nmilidate for hazanlflii'i sub.
Is th»«aterUl
peaoiam oenvniT
> • ro oil in my fbni
is thecheaiul
is the »ai
(organic selmnt)
structure
«n oil of any kind
icandicUte for haz. sub.
•*« candidate for hariTdmis sub.
Figure 1: Rationale for Distinguishing Between Oils and Materials
that may be Hazardous Substances
However, if the material is not derived from a
petroleum or petroleum-like source, then is the material
extractable by an organic solvent such as benzene,
chloroform or carbontetrachloride? If the non-petroleum
derived material is extractable by an organic solvent, then
again the question of chemical structure being defined must
be asked. If the chemical structure of the extractable
non-petroleum derived material is not defined, then it is an
oil of any kind. If the non-petroleum derived material
which is extractable has a defined chemical structure it is a
candidate for designation as a hazardous substance. The last
alternative is that of a non-petroleum derived material
which is not extractable by organic solvent. This material
may be a candidate for designation as a hazardous
substance and would include a multitude of elements and
compounds'and mixtures thereof.
To test the rationale examples of materials are
provided in Table 1. A variety of materials are listed and it
may be noted that the determination is reached quickly for
a majority of materials. This distinguishing rationale may be
used to separate oil from possible hazardous substances.
The actual designation of hazardous substances requires
that the provisions of section 12(a)(l) of the Law (PL
91-224) be considered as published in Code of Federal
Regulations. This part of the Code of Federal Regulations
designates those materials other than oil which pose
imminent and substantial danger to the public health or
welfare as hazardous substances.
CONCLUSION
This paper has demonstrated a rationale which may be
used by government and industry to determine what
materials may be considered oils or possible hazardous
substances under the provisions of sections 11 and 12 of
the Water Quality Improvement Act of 1970. Industry is
provided with regulations that define a harmful discharge of
oil (18 CFR Part 610) and what materials are designated
hazardous substances (18 CFR Part 618). The rationale
developed here should be applicable to a majority of the
materials in question that may be produced, stored,
transported, used and ultimately disposed. Acceptance of
this rationale will allow industry and government to
proceed under the provisons of the Law without detailedlists
of materials.
REFERENCES
(1) Abstract of Proceedings Hazardous Polluting
Substances Symposium. Department of Transportation,
U.S. Coast Guard, New Orleans, Louisiana, September
14-16,1970.
(2) Rose, Arthur; Rose, Elizabeth. The Condensed
Chemical Dictionary. Seventh Edition, Van Nostrand
Reinhold Company, New York, New York, 1966.
(3) Manual on Industrial Water and Industrial Waste Water.
Second Edition, American Society for Testing and
Materials, Philadelphia, Pennsylvania, 1966.
-------
212 OIL SPILL PREVENTION . . .
(4) Standard Methods for the Examination of Water and (6) Water Quality Criteria. National Technical Advisory
Wastewater. Thirteenth Edition, American Public Health Committee, Federal Water Pollution Control
Association, Inc., New York, New York, 1970. Administration, Department of the Interior, 1968.
(5) 1965 Book of ASTM Standards. Part 17, American (7) Brewster, R. Q., McEwen, W. E. Organic Chemistrry.
Society for Testing and Materials, Philadelphia, Third Edition, Prentice-Hall, Inc., Englewood Cliffs, New
Pennsylvania, January 1965. Jersey, 1961.
Table 1:
Examples of Materials to Test the Rationale
to Distinguish Between Oils and Possible Hazardous Substances
Petroleum Chemical Extractable Chemical Oil/
Materials Derived Structure (Solvent) Structure Haz. Sub.
Crude Oil Yes No - - Oil
JP-4 Fuel Yes No - - Oil
Toluene Yes Yes - - H.S.
Tallow No - Yes No Oil
Molasses No - No - H.S.
Refinery Waste Yes No - _ Oil
Plating Waste No - No H.S.
Mix - Kerosene & Benzene Yes No - - Oil
Corn Oil No - Yes No Oil
Stearic Acid No - Yes Yes H.S.
Meat Renderings No - Yes No Oil
Coas Dust Yes No - - Oil
Cresol Yes Yes - - H.S.
Whale Oil No - Yes No Oil
Hexanol Yes Yes - - H.S.
Lacquer Based Paint No — Yes No Oil
Methyl Mercury No - Yes Yes H.S.
DDT Yes Yes - - H.S.
-------
NAVY HARBOR OIL POLLUTION
ABATEMENT: A PROGRESS REPORT
JackE. Wilson
Naval Facilities Engineering Command
INTRODUCTION
Naval shore establishments over the past five years,
under the leadership of the Naval Facilities Engineering
Command (NavFac), in terms of dollars spent for facilities
has a record in pollution control that tops any other single
federal agency. However, most all of the approximate $75
million appropriated by Congress to the Navy for pollution
control over this period, has gone for sewage treatment and
air pollution control. Since the last Joint Conference on
Prevention and Control of Oil Spills in December 1969, the
Navy (again under NavFac leadership for harbor oil
pollution) has greatly intensified its program to prevent and
control oil pollution.
Mr. J. Stephen Dorrler, in his 1969 report,' defined
the Navy harbor oil pollution problem as, "small but
frequent spills." At that time, we had very little in terms of
a Navy-wide capability to solve the problem. Several naval
installations had undertaken efforts at the local level to
prevent and control oil spills. Several installations had barge
skimmers utilizing a weir skimming technique and gravity
oil-water separation, locally fabricated booms, small
response/cleanup teams, and some utilized contractor
cleanup capability who in turn used rather archaic
techniques. General practice was to apply dispersing agents
or carbonized sand to remove the "fire hazard" from the
surface of the water. Since readily available alternatives
were not at hand and development of pollution control
technology was not the Navy's mission, the then accepted
techniques being utilized by non-Navy parties were being
adapted, used and generally accepted, However, due to
public pressure arising out of the national wave of
ecological awareness, and with Presidential, Congressional
direction, Navy leaders established the requirement that,
"Navy oil pollution will be abated." The goal of "zero
pollution," anywhere in the world by mid-decade, was
proposed by a Presidential representative to a NATO
Conference in November, 1970,and this goal has been
amplified throughout the Navy oil pollution control
program and accepted as a target. By Presidential Executive
Orders2'3 we are required to: "Conform to water quality
standards .. . required to use, store, and handle all materials
. . . including petroleum products ... so as to avoid or
minimize the possibilities for water and air pollution."
"Monitor, evaluate, and control on a continuing basis . . .
activities so as to protect and enhance the quality of the
environment."
Prevention
A program is now under way to prevent oil spills from
Navy ships and shore installations. The Secretary of the
Navy and the Chief of Naval Operations have ordered that
no oil will be dishcarged from ship or shore within the
territorial sea and no oil collected in port or ashore will be
dumped anywhere at sea and prohibits the discharge of all
waste oil and oily mixtures in all areas except when
operational emergencies exist.
Several area Commanders have strict local regulations
on ship in-port operations and disallow fueling operations
during times of high risk for spills (e.g., at night) and in
certain publically sensitive or ecologically delicate areas. Oil
watches have been intensified and some hardware
alterations undertaken to prevent or diminish spills.
However, Navy-wide preventive measures have not yet been
undertaken since standard "fixes," that apply
across-the-board to all ships, installations and ship missions,
are not now available. Ship-board alterations are made
doubly difficult since Navy ships and operating procedures
were designed in times when the environment did not enjoy
its present ranking in the list of national priorities and some
ships in use today were designed to easily spill oil when in
certain operational modes, and correcting this feature is
taking considerable effort and money.
213
-------
214 OIL SPILL PREVENTION . . .
To accelerate prevention and control, a comprehensive
Navy-wide study of oil pollution of the environment by
ship and shore facilities is now under way. Phase A, which
identified and quantified the problem, was recently
completed. The prime reason for this new -study was to
accelerate the program so the "zero pollution" target by
mid-decade could be reached. In the study, we are looking
for immediate corrective measures as well as long-range
solutions and the dollars we taxpayers must produce to
meet the national goal.
An example of local efforts, which may be utilized
Navy-wide, is the new bilge pumping practice recently
begun at the Naval Amphibious Base, Coronado, California.
All the amphibious craft are required to pump bilges only
at the pierside defueling station. The station consists of a
receipt and holding tank and a tank truck periodically picks
up the waste for further processing and disposal. Another
local effort to provide immediate solutions to the problem
was a study conducted at San Diego by a group of "salty"
Navy veterans with long experience in shipboard and
fueling operations. Some relatively inexpensive onboard
piping and operating procedures were recommended that
would preclude the prime cause of spills—human errors.
Most naval horbors with a history of serious oil
pollution have an oil pollution contingency plan, but a
recent Chief of Naval Operations instruction directs all
naval installations to prepare one. It is intended that all
Navy contingency plans blend with non-Navy regional or
local contingency plans and augment the national
multi-agency contingency plan. Development of these plans
is now under way.
Containment
The ongoing Navy effort to develop an effective
containment and cleanup program is based on the premise
that there will be some level of accidental spills, no matter
how well the prevention program is planned and executed.
Oil booms are presently used by the Navy where oil spillage
is expected or occurs. Oil booms, their design,
development, manufacture, sale, use and failure, has
probably seen more activity over the past few years than
any other type of oil pollution control equipment. Very
little of this activity has been based on sound technology,
but rather on the desire to exploit a potential market that
could be satisfied through the use of existing manufacturing
processes, available raw products or apparent technical
expertise that could be adapted to meet the urgent demand
with minimal capital outlay and little elapsed time from
initial investment to profitable return. As is well known,
this approach resulted in many instances in failure.
At this time, the Navy does not plan to spend any
money on basic boom development, since it appears from
experience to date that booms that are commercially
available are effective in containing oil in relatively
quiescent waters, characteristic of most Navy harbors.
Instead Navy research and development money will be
invested in an test lagoon at the Naval Civil Engineering
Laboratory (NCEL), Port Huenemen, California, to
determine the best boom commercially available and the
boom best suited for the Navy problem. The lagoon will
be operational late in 1971.
Ideally, we are searching for a boom that is easily
transportable and deployable from a pier or boat, durable
in the sea environment and to the abuses of the congested
harbor protrusions, etc., effective in containing oil in
inshore waters, easily cleaned and stowed and economically
competitive with booms being less desirable in one or
several of the above features.
A military specification for purchasing oil booms was
recently completed by the Navy. It will be upgraded (and
hopefully will become more restrictive) as new information
is obtained from the testing program proposed at the NCEL
test lagoon.
Another promising containment medium is the
monomolecular surface films being investigated and
developed by Dr. Garrett of the Naval Research Laboratory
and reported in the 1969 Conference.4 Dr. Garrett has
recently been conducting field tests on actual spills and the
results are encouraging. The "piston film" or "oil herder,"
as it is often called, has a place in the overall scheme and
mix of Navy oil pollution control tools, especially for quick
response, containment and oil film thickening for more
effective pickup.
NCEL has greatly increased its Research Development,
Test and Evaluation work in oil pollution control over the
past two years. A task that is presently under way, which
relates to containment, is the study of oceanographic
factors affecting oil spills. Also, an evaluation of oil
thickening methods to better affect pickup and prevent
spreading is under way.
An engineering investigation of oil pollution from POL
facilities is presently being conducted for NavFac by Van
Houten and Associates, architects and engineers. This
investigation will continue into the next calendar year and
will provide new design criteria for alteration, repair and
new construction of POL facilities. The information
obtained from Phase A of the Navy-wide study previously
mentioned will be utilized in this investigation. The
approach is to "give a completely fresh look'! at how POL
facilities are constructed and operated and interpret the
findings into firm solutions that are keyed to the new
environmental quality requirements. A similar engineering
investigation of pollution from airfield runoff was recently
completed for NavFac by Howard, Needles, Tammen and
Bergendoff Consulting Engineers. This investigation
resulted in standardized design criteria for handling and
treating all airfield runoff.
Harbor Cleanup
NavFac, which has the responsibility for technical
expertise in harbor cleanup, along with NCEL as the
principal research laboratory for the Navy's shore
establishment, has underway a rigorous program for
developing a harbor cleanup capability.
Navy policy is to utilize commercially available
equipment when applicable to the Navy type harbor and oil
-------
NAVY HARBOR POLLUTION ABATEMENT ... 215
pollution problem, i.e., congested, active harbors with
nested ships, debris, open piers, etc.; in general, confined,
busy waters with difficult to reach nooks and crannies.
The objective in developing a Navy in-house capability
is in accordance with the recommendations of the Battelle
Study,-* conducted in 1969, i.e.. "The two most
cost-effective systems for broad application were found to
be mechanical recovery of spilled material by surface
suction systems, supplemented by mechanical containment,
and the application of chemical dispersants." However,
since dispersants are undesirable due to ecological harm
wrought by the dispersed oil as well as the dispersant,
physical removal is the method being pursued.
Cleanup systems, consisting of containment devices
and pickup equipment (commonly referred to as suction
devices or skimmers) are being developed. The class of oil
spills and environment have been narrowed to four
characteristic categories as follows: 1) minor* near-shore
spills; 2) moderate* near-shore spills: 3) minor inner-water
spills; and 4) moderate innerwater spills.
Figure 2: System for Moderate Near-Shore Spills
Figure 3: System for In-Water Spill Cleanup
Figure 1: System for Minor Near-Shore Spills
*Minor being up to 100 gallons and a moderate spill 100 - 10.000
gallons. At this time the Navy is not actively pursuing development
of a capability for coping with major oil spills except for salvage
operations as specified in the National Contingency Plan.
Four basic cleanup system concepts, which may share
common components, have been developed. All require
boom with manpower for containment and boats for
handling the boom. For a class 1 spill (Figure 1), a small
land-based portable skimmer with pump, piping and
oil/water receptacle that can be transported, deployed and
operated by one or two men at the most, is desirable. The
class 2 concept (Figure 2) consists of land-based multiple
units of small portable skimmers and auxiliary piping and
pumping. Oil/water storage and mobility for the system to
ferry the collected oil to reclamation points without
interrupting the ongoing cleanup operation. Both class 1
-------
216
OIL SPILL PREVENTION
Figure 4: System for High-Rate In-Water Spill Pickup
and class 2 systems would be operated from the shore or
pierside with little mobility in the water except for boom
deployment and maintenance. When the skimmer heads are
operated in the water from boats, the power supply.
receptacles and other support equipment would remain on
shore.
Class 3 and class 4 systems (Figure 3) require in-water
mobility. Basically these systems would merely be class I
and class 2 systems adapted to boats. Also, a large
catamaran type skimmer (Figure 4) is under development
which may be utilized in certain areas where spills get in
open water requiring faster mobility and higher pickup
rates. Small portable skimmers would still be used in
conjunction with the catamaran skimmer for hard-to-get-at
areas not accessable to the large unit.
Generally the movement of Navy spills on the water
are very predictable in most areas and pierside pickup is
usually feasible. The Navy spill as characterized by Dorrler
•^is usually small but frequent, therefore, prepositioned,
compact skimmers with quick response and containment
capability can handle most spills. For larger spills.
additional units can be brought in from other prepositioned
locations as required. The idea is to have flexibility, best
affected by compatible components within the various
systems. Certain components that are now adequate for the
task and are readily available and will always be needed are
being procured, e.g., booms, pumps, boats, storage for oil
and stowage space for equipment, etc. Skimmers are being
procured and used, but better, more desirable ones will
replace these when available. Therefore, it is expected that
only skimmers, a small part of the total system now being
procured, will be technologically obsolete soon. Also, the
small skimmers being purchased now are expected to have a
short useful life, therefore, will require replacement soon
anyway. Also, most booms are .considered consumable
items to a certain degree.
A small portable skimmer, to meet these concept
requirements, is now being developed by JBF Scientific
Corporation under a joint EPA-Navy contract. The skimmer
concept, testing and evaluation was developed by JBF
under previous EPA funding. Optimism is high that the
skimmer will operate effectively in the Navy harbor
environment and as a side benefit, it can be adopted to
collect sorbents, as well as small debris.
The best small portable skimmer developed to date is
the NCEL vacuum pickup device (depicted in Figures 2 and
3). The NCEL device costs about one-sixth as much as
available commerical models, and has been successfully
tested and used in several Navy harbors. The system shown
in Figure 3 is a concept developed around a converted
LCM-6. This system was developed at the Naval Station,
San Diego, California, with technical assistance from
NavFac and NCEL. It utilizes a vacuum principle with the
NCEL suction heads and has been operational since late
1970. Another system is being fabricated at the Public
Works Center, Norfolk, Virginia. The mobile, self-contained
system, working with containment boom, has proved most
effective in San Diego. A more efficient (oil-to-water ratio)
and productive pickup head is desirable and being
pursued.
At present, the major constraint on harbor oil spill
cleanup is the pickup head. The test lagoon at NCEL will
provide a means to test and evaluate, under controlled
conditions, commercial, as well as Navy production models,
as they become available.
A sorbent application, retrieval, regeneration and
disposal system is another type of oil cleanup system of
interest to the Navy. Work is now under way at NCEL and
NSRDL (Naval Ships Research and Development
Laboratory), Annapolis, to test and evaluate sorbent
materials. NCEL has concurrently begun developing the
concept for the total sorbent system. The system would
apply, retrieve, regenerate (if feasible) and dispose (if
required) of the sorbent material. Basically the task is to
evaluate existing equipment that can be adapted to such a
system, undertake necessary R&D efforts to fill equipment
gaps, design and put the components together into a
workable system, establish the operating scheme, and select
the appropriate sorbent(s). The ideal sorbent would be one
that is oleophilic, hydrophobic, easily handled, easily
dispensed and retrieved in open water, does not sink,
non-toxic, can be easily regenerated and reused, and is cost
effective. A sorbent system would not only be an effective
pickup means, but would retard the oil's spreading and
thicken the oil film. Bacterial degradation is another oil
spill cleanup technique under investigation at NCEL for the
Office of Naval Research. NCEL is attempting to isolate
bacteria with the most ravaneous appetite for oil. Bacteria
of the genus Pseudomonas taken from samples of beach
sand and soil in Ventura and Santa Barbara counties, when
placed in flasks with oil apparently consume at least a
portion of the oil. The Laboratory is hoping to isolate the
responsible bacteria and find methods to increase and
control the rate of oil consumption. If effective bacteria are
isolated, then this research task may be extended and
extrapolated to shoreside treatment of oily waste waters.
-------
NAVY HARBOR POLLUTION ABATEMENT ... 217
Treatment and Disposal Ashore
The recently completed Navy-wide survey which
identified the sources, causes, and quanitites of oil
pollution ashore, revealed that very little oil is deliberately
discharged to the environment. However, existing
equipment, operating procedures and housekeeping
practices are resulting in some oil pollution. The intentional, as
well as the unintentional plus accidental spills, will be
prevented or controlled and properly treated. This
intensified effort to control and cleanup accidental spills
and properly treat and dispose of all generated oily wastes,
will result in more treatment and disposal facilities ashore.
Presently the Navy has some existing treatment
facilities consisting of API separators, slop oil gravity
separators, holding ponds and a few emulsion breaking
plants. Contaminated fuels and fuel reclamation plants with
varying degrees of treatment efficiency also exist. Some
new, more effective treatment plants, are now under
construction. On Guam a waste oil treatment and disposal
facility is being constructed. This facility will treat all waste
oil generated in the Apra Harbor Naval Complex from ship
repair facilities, the fuel depot, shop wastes and oily ballast
from ships. The treatment plant has the capability to
handle clean and dirty wastes separately so reclaimable oils
can be saved. The unreclaimed oil will be burned in a
non-polluting high temperature waste oil burner. On the
waterside of the plant, stripped water will pass through
gravity separation, then to chemical and air flotation
emulsion breaking with discharge to a two stage holding
pond before discharge.
At Manchester, Washington, a comparable plant
utilizing physical coalescing and chemical emulsion
breaking is being designed. These are the type plants now
being built for shore treatment of wastes. Other treatment
methods that show promise for efficient treatment at lower
cost are being investigated. For the oily wastes being
produced at Mayport, Florida, treatment consisting of a
chemical precipitating/air flotation package plant (with pH
adjustment to 5.5) is under design. The plant is being
designed to break stable emulsions. The interim facility
currently being operated (gravity separation only) is
producing a waste oil which is being sold at a profit to the
Navy.
A system consisting of an inexpensive coalescing unit
followed by regenerative sorbent filter pakcs is being
investigated for possible use at other locations. The system
has no moving parts, minimal power requirements and is
expected to require minimal operation and maintenance.
In selecting a final treatment alternative, protection of
the environment is the prime criterion, however,
simultaneous production of a saleable or useable
by-product is a highly desirable secondary objective.
Some particular unit processes of interest, from which
the required mix of processes for a particular waste and
effluent requirement could be selected, are API separators,
plate interceptor separators, coalescers, chemical emulsion
breaking units, sorbent filters. Some of the processes are
operational and/or commercially available while the others
are being investigated or developed for Navy use.
CONCLUSIONS
The Navy's present oil spill cleanup bill is estimated at
over $2 million. Research development, test and evaluation
investigations now underway at NavFac and NCEL is valued
in the neighborhood of $300,000. This expenditure could
increase to over $1 million next year if budget proposals are
approved. Equipment now onboard at naval activities, in
the form of skimmers, boats, boom, sorbents and .auxiliary
equipment is valued at over $1 million. The U.S. Navy has
publically declared "war" on oil pollution. The Navy's
program includes ship, aircraft and shore oil pollution
abatement.
"We have maintained a rigorous attack on our
problems of pollution," Navy Secretary John Chafee says.
"We have made a good beginning and are in for the long
pull." Where present technology does not offer immediate
solutions, the Navy has initiated in-house action.
REFERENCES
(1) Dorrler, J.S., "Limited Oil Spills at Naval Shore
Installations" Proceedings Joint Conference on Prevention
and Control of Oil Spills, Dec 15-17, 1969, pp. 151-156,
Americana Hotel, New York, N.Y.
(2) Executive Order 11507, "Prevention, Control, and
Abatement of Air and Water Pollution at Federal
Facilities," Federal Register, Vol. 35, No. 25, Feb 5, 1970.
(3) Executive Order 11514, "Protection and
Enhancement of Environmental Qaulity." Federal Register,
Vol. 35, No. 46, Mar 7,1970.
(4) Garrett, W.D., "Confinement and Control of Oil
Pollution on Water with Monomolecular Surface Films,"
Proceedings Joint Conference on Prevention and Control of
Oil Spills, Dec 15-17 1969, pp. 257-261, Americana Hotel,
New York, N.Y.
(5) Battelle Northwest Institute, "Study of Equipment
and Methods for Removing Oil from Harbor Waters,".
Report No. CR. 70.001 (AD No. 6969880) of 25 Aug
1969.
-------
TREATING AGENTS
Chairman: S. M. Pier
The Pace Company
Co-Chairman: J. R. Gould
American Petroleum Institute
-------
SORBENTS FOR OIL SPILL REMOVAL
by Paul Schaizberg and K. V. Nagy
Naval Ship Research and Development Laboratory
Annapolis, Maryland
ABSTRACT
Materials that float on water, attract and absorb oil and
can easily be removed from the water constitute one of the
most effective means for completely separating spilled oil
from the water environment. Three classes of materials can
be used for this purpose inorganic products, natural
organic products and synthetic organic products. Several
examples of each of these classes are evaluated for their
potential use as sorbents. Laboratory procedures are
utilized to determine oil and water sorption capacity, oil
retention capacity, buoyancy with and without absorbed
oil, effect of petroleum product variation, and sorbent/oil
coherence. Of twenty sorbent materials evaluated, the
polymeric foams exhibited the highest sorption capacities
for oils. These foams also absorb water. While this reduces
their capacity for oil, some of the foams still retain a high
sorption capacity. On the average, much lower oil sorption
capacities were exhibited by the inorganic and the natural
organic materials.
development. These materials have considerable variation in
composition, structure and sorptive capacity.
While some data on sorbent materials have been
published! >2 a systematic laboratory evaluation of many
sorbents being considered for or already in use has not been
reported. Such information is needed to assist in the
selection of sorbents for a variety of uses in cleaning up oil
spills and in establishing design criteria for sorbent dispersal
and recovery systems currently being developed.
Theoretical and Practical Considerations
When sorbent materials are distributed during an oil
spill they can initially contact oil and then water or the
converse; in either case, some competition for the solid
surface between the two liquids can be expected. For
maximum effectiveness, a sorbent material should be
hydrophobic and oleophilic. That is, the solid should not be
wetted by water but should be wetted by oi.
INTRODUCTION
Materials that float on water, attract and absorb oil and
can easily be removed from the water with the oil
constitute one of the most effective means for completely
separating oil from the water environment. These floating
sorbents can be applied from ships and boats, from the air
to and around spills, as well as along the shore to intercept
an advancing slick. In high sea states when containment
devices cease to function, sorbents can be applied, from the
air if necessary, to be collected under calmer conditions or
after being driven to the shore by onshore winds.
In recognition of the potential application of sorbents
for removing spilled oil from water, a large variety of
materials is now commercially available for this purpose.
Others are being made available after some product
The phenomenon of wetting and spreading of liquids
on solids has been extensively investigated by Zisman and
others.3 The contact angle 0 (Figure 1) that a drop of
liquid makes on a plane solid surface is realted to three
surface tensions in equation (1), proposed by Young.4
(1)
where ysv is the surface tension at the solid-vapor inter-
face
>SLis the surface tension at the solid-liquid inter-
face
>Lvis the surface tension at the liquid-vapor inter-
face
221
-------
222 TREATING AGENTS
VAPOR
///////////////////// //
SOLID
Figure 1: Contact Angle of a Drop
Thus, a liquid is non-spreading when 9 =£ 0°;and when
the liquid wets the solid completely, spreading over the
surface, 8 = 0°. Another equation, introduced by Dupre,5
relates the reversible work of adhesion of a solid and liquid,
the three surface tensions
WA = ?sv + >LV 7SL (2)
Combing equations (1) and (2) leads to equation (3)
WA = TLV (COS 0 + 1) (3)
The spreading coefficient S has been defined^ as
S =
Combing equations (1) and (4) leads to equation (5)
S = 7LV (COS 0 - 1) (5)
Equations (3) and (5) describe adhesion and spreading
without the terms ^sv and YSL which are difficult to
measure; it has also been shown7 that
S = WA-WC (6)
where WC is the reversible work of cohesion of the liquid.
Relating equations (3) and (6) leads to
S = 7LV (COS 6 + 1) - WC (7)
For spreading s>o and for nonspreading sS o.
A rectilinear relation has been established^ between
the cosine of the contact angle 9 and the surface tension
TLV for each homologous series of organic liquids such as
the normal hydrocarbons. The liquid surface tension at
which cosine 6 = 1 for a solid is defined as 7C , the
critical surface tension of that solid. Liquids with surface
tensions less than the 7C of a solid will spread on that
solid. For example, a hydrocarbon liquid such as
hexamethyltetracosane (squaline, C3fjH62) with a surface
tension of 28 dynes/cm would spread on polyethylene
( 7C =31 dynes/cm)but not on polytetrafluorethylene
PTFE) ( TC - 18 dynes/cm. Water with a surface tension
of 72 dynes/cm would not spread on either solid. This
indicates that forms of polyethylene should be good
sorbents for oil. Many natural and synthetic organic solids
have values of 7C that are larger than the surface
tensions of petroleum products but smaller than the surface
tension of water so that wetting and spreading of oil on
these solids preferentially to water can be expected.
Inorganic solids that do not have the required value of
7c can be modified by various surface treatments to
product the desired condition.
With some solids sorption does not only involve the
contact angle the liquid makes on its surface. If the solid
consists of fine capillaries or pores, soprtion of the
liquid would also involve capillary rise, where the driving
force is that of the pressure difference across the curved
surface of the liquid meniscus.
The rate of entry v of a liquid into a capillary has been
described** by equation (8) where TJ is the radius of
curvature of the capillary;^LV and TJ are the surface
V = (ryLV/4dn) COS 0
(8)
tension and viscosity of the liquid, respectively; d is the
depth of penetration and 0 the angle of contact between
the liquid and the capillary wall. If 0 is 0°, for the
oil/sorbent contact angle, cosine Q becomes unity and
equation (8) reduces to
V = (ryLV)/(4dn)
(9)
Equation (9) demonstrates that the rate of penetration
of an oil into a capillary is inverselyproportionalto the oil's
viscosity and directly proportional to the capillary radius.
Spilled petroleum products have a viscosity range of two
orders of magnitude. Consequently, depending on the
capillary diameter of sorbent materials, oil penetration rates
could be fast (seconds) as in No. 2 fuel oil or slow (hours)
as in a Bunker C oil. If 9 , = 90° for water/sorbent contact
angles, cosine 0 becomes 0 and the penetration rate
would be 0 for water entering a capillary.
The foregoing has been a theoretical description of the
basic phenomena that would be operating in the process of
sorption of oil by a sorbent in the presence of water. In the
real situation a number of other factors must be recognized
It has been shown^ that a hydrocarbon mixture spreads on
a solid by the advance of a primary film less than 1000A
thick usually followed by a thicker secondary film The
movement of the secondary film results from a surface
tension gradient across the transition zone between the
primary and secondary films. This gradient is produced by
the unequal depletion by evaporation of the more volatile
constituents having a lower surface tension. Thus, volatile
constituents in spilled oil would serve to enhance spreading
of the ofl through the sorbent. However, if a spill remains
uncollected it loses the volatile constituents which have the
greatest effect on spreading. In addition, evaporative loss of
oil constituents increases the viscosity of the residue which
will decrease the spreading rate. When spilled oil ceases
to flow due to low ambient temperatures its viscosity
becomes so high that no spreading occurs. Although the
surface tension of water is high, it can be significantly
reduced by the presence of surface active materials. Thus,
-------
SQRBENTS FOR OIL SPILL REMOVAL 223
the presence of detergents, as contaminants in water along
the coast or due to attempts to disperse spilled oil, can
seriously interfere with the effective use of sorbents since
the detergents will permit water to wet and spread on the
sorbents and thereby compete with the oil. Surface-active
components of spilled oil can also affect the wetting
characteristics of water. Similarly, the use of surface-active
agents to retard spreading of oil on water may interfere
with the subsequent use of sorbent materials.
It is shown by equation (7) that the cohesive energy of
a liquid, We, opposes spreading on a solid. In some cases,
however, cohesive energy can operate favorably. If the
sorbent consists of loose powder or loose fibers the
cohesive energy of the oil between the particles can serve to
produce a congealed mass which retards spreading of the oil
and facilitates removal of the oil/sorbent mixture.
In addition to the wetting, spreading and capillary
phenomena involved in the sorption process, a high
surface-to-solid volume ratio is very important. Once a
material has the desired wetting characteristics, its sorption
capacity is proportional to the material's exposed surface
area.
Methodology
Development of laboratory methods to evaluate
sorbents was influenced by the need for the following
information: maximum ofl sorption capacity, effect of
mixing on oil retention and water pickup, effect of
competition between oil and water for the solid surface,
water sorption capacity, buoyancy retention, oil retention,
effect of petroleum product variation and oil/sorbent
coherence. To provide this information the following two
procedures were utilized.
Procedure A
A weighed sample of sorbent is submerged in the oil
for IS minutes with frequent stirring to assure saturation. It
is then drained for 15 minutes in a wire screen basket
having 1/16 inch openings. If the material contains small
particles which would be lost through this screen a finer
screen is used. After draining, the oil-soaked sorbent sample
is weighed and placed in a one liter bottle one-half full of
synthetic seawater.The bottle is stoppered and shaken for
six hours at a closely controlled rate and amplitude which is
adjusted so that the oil-soaked sorbent is frequently doused
with water. After shaking, the consistency and buoyancy of
the oil/sorbent mixture is noted. The mixture is transferred
to the wire screen basket, drained for IS minutes and
weighed. The water content of the mixture is determined
by distillation in accordance with ASTM Method D95. This
series of tests results in the following information for each
sorbent and petroleum product combination: maximum oil
sorption capacity, ofl/sorbent consistency and buoyancy
retention after snaking, ofl retention and water absorption
after shaking.
Procedure B
A weighed sample of sorbent is placed in a one liter
bottle one-half full of synthetic seawater. The bottle is
stoppered and shaken as in Procedure A but for 30 minutes.
The material is transferred to the wire screen basket or the
finer screen if necessary, drained for five minutes and
weighed to determine water pickup. The water-soaked
sorbent is then thoroughly mixed with oil, drained and
weighed as in Procedure A. Water content is determined by
distillation as in Procedure A. In a separate test, the
weighed sorbent is shaken with water for six hours and its
water pickup and buoyancy determined. This series of tests
results in the following information for each sorbent and
petroleum product combination: water sorption capacity,
buoyancy retention, and oil sorption capacity after prior
contact of sorbent with water.
Petroleum Products
Four petroleum products were used in the evaluation:
a No. 2 fuel oil, a light crude oil (South Louisiana), a heavy
crude oil (Bachaquero) and a Bunker C oil. Table 1 lists
these products along with some of their pertinent physical
properties.
Table I: Properties of Petroleum Products
OIL TYPE
Specific Gravity, 77°F
API0, 77°F
Kinematic Viscosity, Cs,
77°F
No. 2 Fuel
0.856
33.8
3.1
-10
Pour Point, F
Surface Tension, 77°F,
dynes/cm 37.1
Interfacial Tension with
synthetic seawater, 77°F,
dynes/cm 36.0
Emulsification Characteristics
with synthetic seawater, 77°F, 3 min.
Light Crude
(S. La.)
0.854
34.2
7.8
10
34.2
24.9
65 min.
Heavy Crude
(Bachaquero)
0.977
13.3
2600
15
38.6
37.8
2hrs.
Bunker C
0.942
18.9
2800
65
39.9
46.2
none
after
2 wks.
-------
224 TREATING AGENTS
SORBENTS
Representative samples of three classes of sorbents
were tested: inorganic, natural organic and synthetic
organic materials. Table 2 lists the sorbents along with some
descriptive information. Photographs of these materials are
presented in Figures 2-21.
TABLE 2 - SORBENTS
Inorganic
Perlite, treated
Glass wool containing oleophilic additives
Vermiculite, expanded and treated
Volcanic ash, expanded and treated
Natural Organic
Corn cob, ground
Peanut hulls, ground
Redwood fiber, shredded
Sawdust, treated
Wheat straw
Wood cellulose fiber, treated
Synthetic Organic
Polyurethane foams
A. Polyether type, shredded
B. Polyester type, reticulated
C. Polyether type, 1/2 inch cubes
Urea formaldehyde foam
Polyethylene fibers
A. Wool type
B. Sheet, matted
C. Continuous element, non-woven
Polyester plastic shavings
Polystyrene powder
Polytetrafluoroethylene (PTFE) shavings
Figure 2: Perlite
Figure 3: Vermiculite
Figure 4: Volcanic Ash
-------
SORBENTS FOR OIL SPILL REMOVAL 225
%••• *
Figure 5: Corn Cob
Figure 7: Redwood Fiber
-' ^'w;,^
a* ' - - jJfT -
^HjjtfSg
I'igurc 6: Peanut Hulls
Figure 8: Sawdust
-------
226 TREATING AGENTS
Figure 9: Wheat Straw
Figure 11: Polyurethane Foam, Shredded
Figure 10: Wood Cellulose Fiber
Figure 12: Polyurethane Foam, Reticulated
-------
SORBENTS FOR OIL SPILL REMOVAL 227
Figure 13: Polyurethane Foam. Cubes
Figure 15: Polyethylene Fiber, Wool
Figure 14: Urea Formaldehyde Foam
F'igure 16: Polyethylene Fiber, Sheet
-------
228 TREATING AGENTS
Figure 17: Polyethylene Fiber. Continuous Element
Figure 19: Polyester Plastic Shavings
Figure 18: Polypropylene Fiber, Non-Woven
Figure 20: Polystyrene Powder
-------
SORBENTS FOR OIL SPILL REMOVAL 229
Figure 21: PTFE Shavings
Results
Maximum oil sorption capacity expressed in grams of
oil per gram of sorbent is shown in Table 3 for the twenty
materials tested with the four different oils. Precision of the
data is ±5%. A large variation in sorption capacity among
different materials exists. The highest sorption capacities
are exhibited by the foams and the polyethylene fiber
materials. A decline in sorption capacity with decreasing
viscosity of the test oils can be seen. Table 4 shows the
effect of shaking Bunker C oil-soaked sorbent with
synthetic seawater for six hours in terms of water gained,
water/oil ratios, and oil retained. Considerable variation in
water pickup and' water/oil ratios is seen. Some oil-soaked
sorbents gained large amounts of water, while others gained
little. Oil retention varied among the sorbents, but 8 of the
20 sorbents retained more than 90% of the oil. Table 5
shows the sorbents' water sorption capacity after shaking
with seawater for 30 minutes and six hours, buoyancy after
shaking with seawater for six hours, and sorption capacity
for Bunker C oil before and after shaking with water for 30
minutes. There is little difference in most cases in water
sorption between the short and long shaking times. All of
the natural organic sorbents (vegetable origin) lost
buoyancy after shaking with seawater for six hours, while
most of the other sorbents retained buoyancy. With the
Table 3: Maximum Oil Sorption Capacity Grams Oil/Gram Sorbent
Test Oils
Test Oil viscosity at 77°F, cs
Perlite
Vermiculite
Volcanic Ash
Corn cob, ground
Peanut hulls, ground
Redwood fiber, ground
Sawdust
Wheat Straw
Wood cellulose fiber
Polyurethane foams
A. Polyether type, shredded
B. Polyester type, reticulated
C. Polyether type, 1/2 in. cubes
Urea formaldehyde foam
Polyethylene fibers
A. Wool type
B. Sheet, matted
C. Continuous element, non-woven
Polypropylene fiber, non-woven
Polystyrene powder
Polyester shavings
PTFE shavings
Bunker C
2800
4.6
4.3
21.2
5.7
5.8
14.7
3.0
5.8
18.6
72.7
30.3
72.7
72.7
37.0
18.6
i 46.0
21.7
23.4
8.8
5.0
Heavy Crude
2600
4.0
3.8
18.1
5.6
4.3
11.8
3.7
6.4
17.3
74.8 q
24.5
71.7
52.4
27.8
17.6
36.7
18.1
21.7
7.4
6.0
Light Crude
7.8
3.3
3.3
7.2
4.7
•") 1
£..£
6.5
3.6
2.4
11.4
60.0
30.6
66.1
50.3
19.7
11.9
45.4
6.9
20.4
6.6
1.4
No. 2 Fuel
3.1
3.0
3.6
5.0
3.8
2.2
6.4
2.8
1.8
9.0
48.7
27.5
64.9
47.8
16.1
10.6
36.2
4.8
5.8
4.7
1.0
-------
230
TREATING AGENTS
Table 4: Influence of Water on Oil-Soaked Sorbent
Sorption Capacity Water Water/Oil Oil
for Bunker C oil Gain Ratio Retention
Perlite 4.9
Vermiculite 4.9
Volcanic Ash 19.5
Corn cob, ground 5.7
Peanut hulls, ground 6.0
Redwood fiber, shredded 14.7
Sawdust 4.1
Wheat straw 6.0
Wood cellulose fiber 18.1
Polyurethane foams
A. Polyether type, shredded 79.0
B. Polyester type, reticulated 31.6
C. Polyether type, 1/2 in. cubes 72.9
Urea formaldehyde foam 76.2
Polyethylene fibers
A. Wool type 37.0
B. Sheet, matted 19.3
C. Continuous element, non-woven 49.0
Polypropylene fiber, non-woven 21.7
Polystyrene powder 24.0
Polyester shavings 8.4
PTFE shavings 4.2
notable exception of the foams, little reduction in oil
sorption capacity is seen for sorbents preferentially
contacted with water.
Discussion
While the highest oil sorption capacities are exhibited
by the foams, these materials also absorb a large amount of
water. When preferentially and vigorously contacted with
water for 30 minutes some of the foams lose significant
capacity to absorb oil (Table 5). Nevertheless, two of the
foams still show a high capacity for oil sorption. The
relatively high water pickup of a number of the oil-soaked
sorbents as shown in Table 4 is attributed, in part, to the
formation of water-in-oil emulsions since the Bunker C oil
used for this purpose showed good emulsion forming
characteristics (Table 1). Table 6 shows the water/oil ratios
of several oil-soaked sorbents after shaking in seawater for
six hours. The highest ratios are found for the Bunker C oil,
indicating the formation of water-in-oil emulsions. The
variation in the water/oil ratios between sorbents suggests
different degrees of sorbent involvement in emulsion
stabilization.
When feasible, it is preferable to apply sorbent directly
to the oil slick and achieve thereby preferential contact
1.7
0.8
46.5
3.6
4.9
15.5
12.9
5.0
12.6
80.0
7.5
82.0
84.0
25.0
5.5
2.5
15.8
78.0
25.5
6.2
0.35
0.18
2.38
0.62
0.82
1.05
3.14
0.83
0.70
1.01
0.24
1.04
1.10
0.68
0.28
0.06
0.73
3.25
3.04
1.48
71
82
85
96
58
78
83
98
92
66
83
89
97
65
99
98
68
90
64
67
with the ofl. When thoroughly soaked with either Bunker C
or heavy crude oil, all sorbents tested retained buoyancy
despite vigorous shaking with seawater for six hours. Based
on a number of tests, similar results are expected for the
other test oils. The most rigorous test conducted for
buoyancy retention consisted of shaking the sorbent with
water for six hours. Loss of buoyancy under those
conditions is an undesirable sorbent characteristic, since it
is not always feasible to apply sorbents directly to the oil
slick. Even if the sorbent can be applied directly to the
slick, only partial coating by the oil can be expected under
field conditions. If subsequent contact with water causes
loss of buoyancy, the oil on the sorbent will be sunk with
it.
Another property of interest is the oil/sorbent
consistency, since that plays a role in the method of
retrieval. This is influenced partly by the viscosity of the oil
and partly by the nature of the sorbent. Figures 22-25 are
photographs which illustrate the influence of the oil. In
those figures polyurethane foam C is seen after being
saturated with each of the four test oils and shaken in
seawater for six hours. The two viscous oils have formed
distinct clumps with the sorbent and are therefore relatively
easy to remove from the water. The two less viscous oils,
however, do not form a coherent mass with the sorbent
-------
SORBENTS FOR OIL SPILL REMOVAL 231
Table 5: Influence of Water on Buoyancy and Sorption Capacity
Sorption Capacity
for Water g/g
after shaking for
30 min. 6 hrs.
Perlite
Vermiculite
Volcanic ash
Corn cob. ground
Peanut hulls, ground
Redwood fiber, shredded
Sawdust
Wheat straw
Wood cellulose fiber
Polyurethane foams
A. Polyether type, shredded
B. Polyester type, reticulated
C. Polyether type, 1/2 in. cubes
Urea formaldehyde foam
A. Wool type
B. Sheet, matted
C. Continuous element,
non-woven
Polypropylene fiber, non-woven
Polystyrene powder
Polyester shavings
PTFE shavings
3.8 3.8
3.9
6.6
6.8
2.9
7.6
4.5
4.4
12.8
38.9
18.4
28.8
33.2
3.3
1.5
9.0
3.2
13.8
6.4
0.4
3.4
4.3
5.2
6.4
5.1
7.6
4.8
5.3
12.6
34.5
26.6
45.2
48.2
4.2
6.0
12.0
4.7
18.1
6.6
0.8
Buoyancy
after shaking
for 6 hrs.
floats i
sinks
floats
sinks
sinks
sinks
sinks
sinks
sinks
floats
floats
floats
floatS2
floats
floats
floats
floats
floats
floats
floats
Ratio of Sorption
Capacities for Bunker C
Oil, after/before
shaking with water
1.0
0.2
0.8
1.0
0.8
0.4
1.0
0.9
1.0
0.6
0.6
0.7
0.2
1.0
1.0
0.7
1.0
1.0
1.0
1.0
... ..
~
Figure 22: Polyurethane Foam
(Cubes) with No. 2 Fuel Oil
Figure 23: Polyurethane Foam
(Cubes) with Light Crude Oil
Figure 24: Polyurethane Foam
(Cubes) with Heavy Crude Oil
Figure 25: Polyurethane Foam
(Cubes) with Bunker C Oil
which would make retrieval more difficult. Another
illustration of the role of viscosity of the oil is seen in
Figures 26 and 27. In these photographs PTFE shavings
have been soaked in oil and then shaken in seawater for six
hours. As has been pointed out earlier, PTFE is an
undesirable sorbent material since it is not easily wetted by
oil. Nevertheless, when treated with the viscous Bunker C
oil a thick clump is formed, but the light crude oil produces
a loose structure with the PTFE shavings. When soaked
with Bunker C oil all the sorbents, except one, could be
-------
232 TREATING AGENTS
Test Oils
Polypropylene fiber
Sawdust
Redwood fiber
Wood cellulose fiber
Polyester shavings
Polyurethane foam
Table 6: Water/Oil Ratios of Oil-Soaked Sorbents
No. 2 Fuel Light Crude Heavy Crude
0.39
0.27
0.01
0.11
0.36
0.58
0.07
o.:o
0.03
0.60
0.09
0.25
0.12
0.38
0.33
Bunker C
0.73
3.14
1.05
0.70
3.04
1.04
m
Figure 26: PTFE Shavings
with Light Crude Oil
Figure 27: PTFE Shavings
\vith Bunker C Oil
retained in the wire screen basket having 1/16 inch
openings. The volcanic ash sorbent passed through the
screen.
The test methods used were applied equally to all
sorbents. Consequently, the results have relative
significance at least. An important consideration is to what
extent the results from these tests can be related to the
large scale application of sorbents. Results of some large
scale sorbent tests have been reported.^ These results
showed oil-to-sorbem weight ratios for perlite (5), hay (4)
equivalent to straw), urea formaldehyde foam (26) and a
polyurethane foam (46), all of which are similar to results
reported in Table 3. Based on this comparison it seems
reasonable that the laboratory results reported in this paper
can be applied to the selection of sorbents for large scale
operations. The vigorous shaking of the oil/sorbent
mixtures and sorbents in seawater for six hours may be
considered too severe a test, especially when compared to
calm conditions in sheltered areas. For other situations,
however, it may not be severe enough, particularly since
sorbents, oil-soaked or not, can encounter exposure to the
water lasting for days.
Cost-effectiveness of the sorbents tests was not
considered since this involves not only the initial cost of
materials but also the nature of the oil spill, environmental
conditions and other factors, all of which lie beyond the
scope of this paper. One factor, in addition to high sorption
capacity, which can have a profound influence on
cost-effectiveness is sorbent reusability. Some of the foams
and other sorbents appear to have reusability potential, but
this needs to be investigated further. Another factor is
on-site generation of sorbents which is a potential exhibited
by the synthetic foams. This, too, needs to be investigated.
Whatever sorbents are used, they must function as part of a
system which brings the material to the spill site, disperses
and recovers them, reuses them if feasible, and finally
disposes of them.
CONCLUSIONS
Based on the sorbents tested, and within the
limitations of the laboratory procedures utilized, the
following conclusions can be drawn:
1. Polymeric foams have the highest sorption capacities for
oils. This capacity is essentially independent of the viscosity
of the oils. Foams also absorb water readily, which reduces
their capacity for oil sorption. Nevertheless, two of the
polyurethane foams still show the highest oil sorption
capacity of all sorbents tested.
I. Polyethylene fiber products exhibit a good sorption and
polypropropylene capacity for oils which is unimpaired by
prior contact with water. This is also shown by a
polystyrene powder.
3. Inorganic sorbents do not show high oil sorption
capacities. These capacities are dependent on the viscosity
of the oils resulting in sharply reduced sorption for the less
viscous oils.
4. Natural organic sorbents (vegetable origin) lose
buoyancy when preferentially and vigorously contacted
with water. They do not show high sorption capacities for
oils.
5. The laboratory methods for evaluating oil sorbents are
satisfactory and the results can be applied in the selection
of sorbents for full scale sorbent dispersal and recovery
systems.
ACKNOWLEDGMENTS
This paper represents a portion of an investigation
sponsored by the U. S. Coast Guard, Division of Applied
Technology, Washington, D. C. The cognizant technical
manager is Cdr. W. E. Lehr, head, Oil Pollution Control
Branch.
-------
SORBENTS FOR OIL SPILL REMOVAL 233
The authors are grateful to Mr. Leo T. McCarthy,
Edison Water Quality Laboratory, Environmental
Protection Agency, Edison, New Jersey, for his helpful
comments and suggestions during the course of this
investigation.
REFERENCES:
1. Struzeski, Jr., E. J. and R. T. Dewling, "Chemical
Treatment of Oil Spills," Proceedings Joint Conference on
Prevention and Control of Oil Spills, New York, N.Y.,
December 15-17,1969.
2. Milz, E. A., "An Evaluation - Oil Spill Control
Equipment and Techniques" Report on the 21st Annual
Pipeline Conference, Dallas, Texas, April 13-15,1970.
3. Zisman, W. A., "Relation of Equilibrium Contact Angle
to Liquid and Solid Constitution," in Contact Angle,
Wettability, and Adhesion, Washington, American Chemical
Society, 1964.
4. Young, Thomas, Philosophical Transactions of the
Royal Society (London), Vol. 95, p. 65,1805.
5. Dupre, A., Theorie Mechaniqtte de la Chaleur, Paris
Gauthier-Villars, p. 369,1869.
6. Cooper, W. A. and W. A. Nuttall, Journal of Agricultural
Science, Vol. 7, p. 219, (1915).
7. Harkins, W.D., Chemical Reviews, Vol. 29, p. 408,1941.
8. Washburn,E.W./%js/cfl/'^ev/ews, Series 2, Vol. 17, p.
273,1921.
9. Bascom, W.D., R.L. Cottington, and C.R. Singleterry,
"Dynamic Surface Phenomena in the Spontaneous
Spreading of Oils on Solids," in Contact Angle, Wettability,
and Adhesion, Washington, Aerican Chemical Society,
1964.
-------
LABORATORY INVESTIGATION INTO
THE SINKING OF OIL SPILLS WITH
PARTICULATE SOLIDS
O. Pordes
Egham Research Laboratories
Shell Research Limited
United Kingdom
and
L. J. Schmit Jongbloed
KoninklijkelShell Exploratie en Produktie Laboratorium
The Netherlands
ABSTRACT
This paper describes experimental laboratory work
relevant to the sinking of floating oil spills.
The results show that aqueous sand slurries treated with
an amine acetate salt have satisfactory sinking and retention
properties. In general, aqueous sand slurries containing
cationic wetting agents of widely different water solubilities
can effect sinking provided that the concentration of the
wetting agent is within the range necessary to give
oleophilic sand surfaces. Fine powders have better retention
properties than have sands, but are unsatisfactory sinkers
unless mechanical stirring is provided.
To sink stable water-in-oil emulsions effectively a sinker
application rate is required which allows for the cohesive
structure of the emulsion as well as for the wetting of the
sinker by the oil phase.
Work relevant to fears that bottom trawling fishing gear
may befouled in areas where oil slicks had been sunk shows
that under very severe experimental conditions hydrophilic
and oleophilic fishing net twines can be fouled, but the
significance of this in relation to practical considerations is
unknown. The feasibility of preventing carpet formation by
sunken oil/solid masses by reducing the size of the sinking
oOjsolid droplets and delaying or preventing their coales-
cence by spraying a dispersant onto the oil before sinker
application is discussed.
Standard laboratory procedures in direct support of the
Shell Sand Sink method are detailed.
INTRODUCTION
For effective sinking of floating oil spills, the prime
requirement is for a participate solid of high density. The
sinking agent should preferably have a large specific surface
area and should be wetted by oil in the presence of water.
In order that the oil be retained on the bottom of the sea,
to be ultimately buried by sand or silt, or biologically
degraded, it must not be displaced by water from the solid.
An effective sinking method may also be required to
deal with a wide variety of oil types ranging from low
viscosity crude oils to stable water-in-oil emulsions.
With these requirements in mind the aim of this work
was to compare some particulate solids with regard to their
effectiveness as sinking agents, and to compare methods of
rendering solid surfaces oil wettable in the presence of
water.O)
As apprehension has been expressed that bottom fishing
gear may be fouled when dragged through sunken oil/sinker
mixtures^ the possibility of fouling of different fishing
net twines was examined.
General Laboratory Evaluation of Sinker Agents
Initial Scouting
Within hours of the grounding of the Torrey Canyon
some experiments on sinking floating Kuwait crude oil
films were carried out with sandy sinkers; these ranged
from untreated dry or wet sand to sands coated with
bituminous cutbacks or emulsions, paraffin wax and
aqueous dispersions or solutions of cationic surface active
agents.
Sands coated with bituminous cutbacks and emulsions
proved to be ineffective, whilst sands coated with aqueous
solutions or dispersions of cationic surface active agents, or
dry sand coated with paraffin wax offered useful possibili-
ties. Without mechanical stirring of the sand slurry/oil,
235
-------
236 TREATING AGENTS
sinking was effected by using cationic surface agents of
widely different water solubilities provided that the concen-
tration was within the critical range necessary to give
oleophilic sand surfaces. As shown in Table 1, the capacity
of wetting agents such as fatty di-amines and quaternary
ammonium salts to anchor the oil at the bottom without
previous stirring of the slurry/ofl is limited, and except in
the case of the sand slurry treated with 0.05% cetyl
pyridinium bromide (Fixanol C) much of the oil returned
to the surface within 24 hours after sinking.
When mechanical stirring was used to mix the sand
slurry and the oil, long-term retention on the bottom was
achieved with water insoluble (e.g. 0.1% di-alkyl quaternary
ammonium chloride (Arquad 2HT-75) and soluble (e.g.
0.05% Fixanol C) cationic wetting agents.
Experimental details and results are given in Appendix 1.
Comparison of Sinking and Retention Powers of
Various Particulate Solids
In this next and wider series of experiments the
effectiveness of various particulat solids, i.e., sands and fine
powders, to sink floating oil together with their ability to
retain the sunken oil was examined. The particle size
analysis, as determined by sieving through BS sieves, is
given in Table 1.
Table 1 : Particle Size Distribution
Particle size range
(mm)
-2.411 + 1.204
-1.204+0.599
-0.599 + 0.295
-0.295 + 0.152
-0.152 + 0.076
-0.076
-0.076+0.037
-0.037
Sand No. 1
0
0
3.8
67.5
26.8
1.9
—
—
Sand No. 2(l)
0
0
0
0
93.4
6.6
—
—
of Solid Sinker Materials
Siliconized sand' '
(%W)
0.5
5.0
51.0
41.5
1.5
0.5
—
—
SPFA(3)
0
0
2.0
6.8
18.0
_
20.2
53.0
Snowcal(4)
0
0
0
0
0
_
0
100
(48%< 0.003)
*• ^Fraction passing B.S. sieve No. 100(0.152 mm) of Sand No. 1.
' 'Sand treated with water-based sodium methyl siliconate solution.
* 'Pulverized fuel ash treated with methyl trichlorosilane.
^Treated whiting.
The results are tabulated in Tables 2 and 3 and show
that:-
(a) sands treated with sflicones or paraffin wax have
satisfactory oil-sinking properties with or without
the provision of mechanical stirring. Aqueous sand
slurries treated with an amine acetate salt (Armac T)
behave similarly. There is no clear pattern of effect
of Armac T concentrations between 0.05-0.125%
(weight of dry sand), but in all cases at least
two-thirds of the oil is retained on the bottom.
More finely graded materials, treated whiting or
chalk and silane treated pulverized fuel ash, require
an impracticably long time to sink floating oil ex-
cept for oils of low viscosity. However, these
powders display a high degree of sinking efficiency
if mechanical agitation is provided.
(b) Sunken oil was more effectively retained on the
bottom by the powdery sinking agents than by the
comparatively coarse sands. Similarly, finer fractions
of sand display better oil retention than the coarser
ones.
However, irrespective of the fineness of the grading,
the sunken oil/solid masses obtained with wax-
coated sand are in all cases the firmest and most
cohesive of the sunken masses.
(c) It appears that the rate of application of sinking
agents, in particular fine powders, plays a more
important role in obtaining optimum sinking effec-
tiveness than is sometimes suspected. It is suggested
that fine powders should be applied at a rate not
much faster than that at which the particles sink
into or are encapsulated by the oil.
Experimental details are given in Appendix 2.
-------
TREATING AGENTS 237
Table 2: Sinking and Retention Effectiveness of Solid Sinkers
Sinker
Sand No. l/ArmacT(1>
Sand No. 2/Armac T
Sand No. I/wax 2.2>
Sand No. 2/wax 2.0
Snowcal
Nautex H
SPFA
Siliconized sand
Sand No. 1
Kuwait crude oil (25% topped)
% oil sunk
Sinker
Spreading
90
98
85
85
50
50
2
85
-
Spreading
and
staring
90
98
95
90
98
90
99
85
-
% oil on dish bottom
Days after
Spreading
1 7 14
90 88 66
95 90 71
85 85 74
85 80 75
98 98 98
99 98
0 98 98
85 80 56
_
Spreading and
stirring
1 7 14
90 90 69
95 95 74
90 85 70
85 85 71
96 96 96
98 98
99 99 99
80 75 42
- - -
Shell Heavy Fuel Oil B
% oil sunk
Sinker
Spreading
99
99
99
98
0
0
0
99
85
Spreading
and
stirring
99
99
99
98
99
99
99
99
-
% oil on dish bottom
Days after
Spreading
1 7 14
80 66
99 95 76
95 82
95 90 87
000
000
000
75 42
70 60 23
Spreading and
stirring
1 7 14
99 76
98 98 91
85 72
95 90 81
99 99 99
99 99 99
99 99 99
80 60
_
*• '0.05%w Armac T on weight of dry sand.
140/14S°F m. pt. fully refined paraffin wax on weight of dry sand.
Table 3: Effect of Concentration of Armac T on the Sinking of Topped Kuwait Crude Oil
Sinker
Armac T
(%w of dry sand)
Appearance
1 hour after sinker application
4 hours after sinker application.
Quantitative determination of Oil sunk, %w
168 hours after sinker application.
1
^ «™^J Mr. 1
0.05
0.075 O.J
* \bout 95*& oil sunk
0.125
Oil/solid in discrete droplets on the bottom.
As after 1 hour
70
~* Total coalescence of oil/solid droplets »-
80 70
77
The Sinking of Floating, Stable, Water-in-Oil
Emulsions (Chocolate Mousse)
Some experiments were carried out to assess the ability
of Armac T treated sand slurries to sink floating water-in-oil
emulsions. Observations made during this work suggest that
for the sinking of mousse the following criteria obtain:-
1. If the sand slurry is scattered evenly but rapidly the
mousse will quickly sink below the surface of the
water. However, if there has been insufficient time
either for the oil to wet the sand or for the sand to
sink into the emulsion, the sand will be washed off
the surface of the mousse, and the emulsion will rise
to the surface.
2. If the sand is spread unevenly and rapidly over the
raft of mousse, the mass will sink, turn turtle, shed
the sand [for the reasons given in (1)] and surface
again.
3. It is imperative that the solid sinker be applied at
least slowly enough for the solid to be wetted by the
oil at its contact area before sinking is effected. This
slow rate of application will achieve adhesion of the
sand to the emulsion and so resist washing off during
subsequent sinking. There is an indication that more
rapid wetting is obtained with the 0.1% than with the
0.5% Armac T treated sand slurry (see Table 4).
4. It is thought possible to sink and probably retain the
mousse on the bottom by spraying the sinker slurry
with sufficient force to penetrate into the body of
the mousse.
Experimental details are given in Appendix 3.
-------
238 SINKING OF SPILLS WITH PARTICULATE SOLIDS
Table 4: Effect of Concentration of Armac T and of the Time Taken to Apply Sinker on the Sinking
of Floating Water-in-Oil Emulsions (average water content - 78%w)
Oil
Sinker solid
Armac T %w
Time taken to apply sinker (minutes)
Estimate of emulsion floating on top (%w)
Hours after sinker application
0
1
24
168
Topped Kuwait crude oil (25% topped)
Sand No. 1
0.05
15
40
40
40
50
0.05
45
10
10
10
15
0.1
15
25
25
24
30
0.1
45
0
0
0
0
0.05
15
20
20
30
40
0.1
15
15
15
14
20
Laboratory Work in Direct Support
for the Shell Sand Sink Method
Two laboratory test procedures, developed by KSEPL,
Rijswijk, which were instrumental in establishing the Shell
Sand Sink Method* as a practical large scale, anti-pollution
measure are the adhesion test and the spraying test.
Adhesion test
This test is used to determine the ability of wetting
agents to render water-wet sand surfaces oleophilic. It is
used for screening the great number of wetting agents
available as well as for determining the optimum amount of
a chosen surfactant under certain given conditions.
In brief, 50 g of dry sand is mixed with sea water and
treated with the surfactant. The slurry is then well mixed
with 30 g of ofl, transferred to a 250 ml flask, topped up
with sea water and allowed to stand for 24 hours, after
which the amount of ofl floating on top is measured. The
result is expressed in kg ofl retained by 1 kg of dry sand.
The test is repeated with different amounts of wetting
agent, the results plotted and the optimum determined;
It will, of course, be appreciated that when this test
procedure is used for screening wetting agents the three
principal parameters, i.e., water, sand and oil, are kept
constant.
Fuller test details are given in Appendix 4.
*The applicability of this method on the open sea was confirmed by
the KSEPL sea trial on the 8th April, 1970. The report on this trial
"The Shell Sand Sink Method" is available on request at Konin-
klijke/Shell Exploratie en Produktie Laboiatorium, Rijswijk, The
Netherlands.
Spraying test
This test is complementary to the adhesion test and is a
small-scale, sand slurry spraying test in which materials and
concentrations found promising in the adhesion test are
further examined.
In brief, a 5 mm thick layer of oil is spread on sea water
in a 3.5 m long, 1.25 m wide and 0.5 m deep tank. A
multinozzle sprayer travels at constant height and speed
once over the tank. The surfactant treated sand/sea water
(20 kg sand) mixture is sprayed at a constant angle into the
oil layer (15 kg), and hits it with constant impact velocity.
The amount of oil floating on the surface of the water after
at least 12 hour standing is considered as a yardstick of
performance.
Fuller test details are given in Appendix 5.
Results
In comparable cases, less oil is generally retained per kg
of dry sand in the static adhesion test than in the dynamic
spraying test. It appears also that the best performances in
the adhesion test are not necessarily top-ranking in the
spraying test. The difference between the results of the two
test methods is almost certainly caused by:
(a) differences in the mixing intensity of sand with oil,
(b) differences in the oil/sand ratios used,
(c) differences in the water/sand ratios used and
(d) differences in ambient test temperatures.
However, more weight is given to the spraying test as it
approaches practical sea conditions more closely than the
adhesion test.
Considering the factors affecting the retention of ofl by
sand it seems that the optimum surfactant addition for an
average North Sea sand (medium particle size of about 250
-------
SINKING OF SPILLS WITH PARTICULATE SOLIDS 239
micron with an insignificant fraction larger than 1000
micron) lies between 250 and 500 ppm. Finer sand, or sand
contaminated with a little clay, requires a larger amount of
wetting agent, such as 1000 ppm, to achieve maximum
effectiveness.
It takes less sand to sink heavy and viscous oil than a
light and thin crude. Too coarse a sand affects the oil
retention unfavorably, while too fine a sand is costly on
account of higher surfactant requirements. Sand with a
minimum clay and silt content is thus the preferred sinker
aggregate. A mixing time of 10-20 seconds at high shear
rate is sufficient to treat the sand with surfactant. A 50/50
surfactant solution in isopropyl alcohol or glycol facilitates
handling, and care should be taken to choose a surfactant
solvent system of pour point low enough to cope with the
lowest temperatures expected. From the spraying tests, in
which variables such as wetting agent concentration, slurry
weight, nozzle speed and angle, and oil-layer thickness
could be studied, it was seen that 95% of a 5 mm layer of
heavy crude could be sunk using a 1:1 weight ratio of
sand/oil. It further appeared, that the useful application of
the sand slurry would be limited by the viscosity of the oil,
with the lower limit being somewhere around 150 cS at sea
temperature. This is, in practical terms, not considered to.
be a serious limitation, because most lighter crude oils will
have weathered sufficiently after a comparatively brief
exposure at sea to come within this viscosity limit.
Furthermore, recent experiments carried out with 4-10 cS
light Nigerian crude (carried out at the time of the salvage
operation for the "Pacific Glory" October-November 1970)
indicated that, though the viscosity of the oil is below the
value so far accepted as the critican minimum, successful
sinking can be achieved if the normally recommended
sand/oil ratio is increased from 1 to 2.
Oleophilic and Hydrophilic Fishing Net Twines
Under the severe experimental conditions (see Appendix
6), fishing net twines, both natural and synthetic, were
fouled by oil/sinker masses. However, a natural and
hydrophilic one, e.g. manila twine, was less prone to fouling
than the synthetic and oleophilic polyethylene and
polypropylene materials. No oil/sinker mass can be singled
out as causing a minimum amount of fouling, and a
particular sinker cannot therefore be recommended (see
Table 5). It seems that experimental conditions can be
created under which any twine will be contaminated by any
oil/sinker mastic. However, it has not yet been established
that conditions at sea are as severe as those chosen for these
experiments.
Experimental details are given in Appendix 6.
Table 5: The Relative Susceptibilities of Fishing Net
Twines to Fouling by Sunker Oil/Solid Mastics*
Twine
15/12 Orange polythene
15/32 Orange polythene
360P Ulstron (polypropylene)
90P Ulstron (polypropylene)
3/1 10 Manila twine
Fouling - increase
in weight of twine
g/m
2.7
6.9
5.0
1.2
1.5
mean 3.5
%w
160
150
155
165
15
130
*The oil/solid mastics were obtained by sinking topped Kuwait
crude oil and fuel all with Armac T sand slurry, waxed sand,
siliconized sand, SPFA, Snowcal and Nautex H. As only very minor
differences in fouling by the different oils and solid sinkers were
obtained, average values are tabulated.
Fouling of Fishing Net Twines
As apprehension has been expressed that bottom fishing
gear may be fouled when dragged through sunken oil/sinker
masses some laboratory work was also carried out with
typical fishing-net twines.
Cum °lo weight rcto
100
60
Normdi typ
0
1000
Figure 1: Sieve Analysis Silver Sand
Size and Coalescence of Oil/Sinker Droplets
Further to the fears that fishing operations may be
hindered through fouling in areas where oil slicks had been
sunk one looked into possibilities of: —
(a) reducing the size of sinking, discrete oil/solid drop-
lets, and
(b) preventing carpet formation at the bottom of the
sea by inhibiting or delaying the coalescence of the
sunken droplets.
The feasibility of this approach was indicated in that by
using for example Armac T treated sand slurries as the
sinker, a reduction in the size of the sinking oil/solid
droplets and a delay in the coalescence of the sunken
droplets were achieved by spraying an oil-soluble surfactant
solution onto the floating oil slick before application of the
sinker (see Table 6).
Applying the dispersant onto the floating oil film
immediately before the application of the sinker was found
to be a more effective way of preventing or delaying
-------
240 TREATING AGENTS
Table 1 A: Sinking of Floating Oil with Sand Slurries (Slurry Scattered)
Dish
No.
1
2
3
4
5
7
8
9
10
11
12
13
14
15
5
Aqueous phase
of slurry
containing (%w)
1 Duomeen C
1 Duomeen 12
1 Duomeen S
1 Arquad S-50
1 Arquad 2HT-75
0.1 Arquad S-50
0.01 Arquad S-50
Filtered water from 1 Arquad 2HT-75 dispersion
0.5 Arquad S-50- 0.5 Arquad 2HT-75
0.1 Arquad 2HT-75
1 Fixanol C
0.1 Fixanol C
0.01 Fixanol C
0.05 Fixanol C
lOOg of dry sand coated with 2 140/145°F
FRPwax*
Condition of oil
%w oil sunk immediately
after application of slurry
About 95
About 95
About 95
About 95
About 95
About 95
About 95
About 95
About 75
About 99
About 80
About 95
About 95
About 99
About 99
%w oil floating, 24 hours
after application of slurry
About 30
About 70
About 30
About 70
About 30
About 70
About 70
About 70
About 85
About 25
About 90
About 80
About 40
About 5
About 1-2
*Waxed sand was included to serve as a reference standard.
After noting the conditions of the oil 24 hours after the application of the slurry, the oil and sand were hand mixed.
The results are given in Table 2.
Table 2A: Sinking of Floating Ofl with Sand Slurries (Hand mixing with a spatula of the oil and sand in the
dish 24 hours after the slurry application — see Table 1 A)
Dish
No.
1
2
3
4
5
7
8
9
10
11
12
13
14
15
6
Aqueous phase
of slurry
containing
l%w Duomeen C
l%w Duomeen 12
l%w Duomeen S
l%w Arquad S-50
l%w Arquad 2HT-75
0.1 %w Arquad S-50
0.01%w Arquad S-50
Filtered water from l%w Arquad 2HT-75 dispersion
30.5%w Arquad S-50 - 0.5% Arquad 2HT-75
0.1% Arquad 2HT-75
l%w Fixanol C
0.1%w Fixanol C
0.01%w Fixanol C
0.05%w Fixanol C
100 g of dry sand with 2%w 140/ 145° F FRP wax
Condition of oil
Immediately after mixing
%w of oil sunk
About 99
About 99
About 99
About 95
About 99
About 99
About 99
About 30
About 95
About 99
About 99
About 99
About 99
About 99
No mixing
168 hours after mixing
%w of oil floating
About 20
About 30
About 15
About 50
About 1
About 10
About 25
About 80
About 30
About 1
About 50
About 10
About 3
About 1
About 1
-------
SINKING OF SPILLS WITH PARTICULATE SOLIDS 241
Table 6: The Effect of Spraying a Dispersant Solution onto the Floating Oil Immediately Prior to the Sinker Application
Oil
Solid Sinker
ArmacT
(%w on dry sand)
Dispersant
(%w on floating oil)
Appearance
Hours after
sinker
application
2
168
Topped Kuwait Crude Oil (25% topped)
Shell Heavy Fuel Oil "B"
< ^inH Nrt 1 -f-
-i "Of t
0
About 90% of oil
sunk is discrete
droplets of 1-2
cm dia. Some
coalescence
As after 1 hour
Extensive
coalescence
5
About 75% of oil
sunk in discrete
droplets of about
1 cm dia. No
coalescence
Extensive
coalescence
Extensive
coalescence
10
About 80% of oil
sunk in discrete
droplets of
<0.5 cm dia. No.
coalescence
As after 1 hour
No coalescence
0
About 90% of oil
sunk in large,
discrete drops of
>2 cm dia. Some
coalescence
Some
coalescence
Some
coalescence
5
About 80% of oil
sunk in discrete
droplets of
< 1.0 cm dia. No.
coalescence
Some
coalescence
Some
coalescence
10
About 80% of oil
sunk in discrete
droplets of
<0.5 cm dia. No
coalescence
No coalescence
No coalescence
coalescence than either applying it directly below he
floating oil film or mixing it with the Armac T treated sand
slurry.
Experimental details are given in Appendix 7.
REFERENCES
1. United States of America, Patent Specification No.
2367384 Sept. 1942.
2. System Study of Oil Cleanings Procedures. Volume
1: Analysis of Oil Spills and Control Materials. G.A.
Gflmore, D.D. Smith, A.H. Rice, E.H. Shenton and W.H.
Moser, Dillingham Environmental Company, Dillingham
Corporation 1970.
3. SA. Berridge, M.T. Thew and A.G. Loriston-Clarke.
J. Inst. Petrol.
APPENDIX 1
Initial Scouting Tests
Materials Used
1. Cationic wetting agents
1.1 Fatty di-amines
Duomeen S
Duomeen C
Duomeen 12
2. Sand
Sand No. 1
Buckland Sand and Silica Co.
Armour Hess Chemicals Ltd.
Armour Hess Chemicals Ltd.
Armour Hess Chemicals Ltd.
1.2 Quaternary ammonium salts
Arquad S-50
(mono alkyl quaternary ammonium
chloride) Armour Hess Chemicals Ltd.
Arquad 2HT-75
(di alkyl quaternary ammonium
chloride) Armour Hess Chemicals Ltd.
Fixanol C
(Technical grade of cetyl
pyridinium bromide) ICI
3. Sea water
Artificial sea water was prepared by adding the following
salts to distilled water: —
2.5%w NaCl
1.1 %w MgCl2
0.4%w
4. Fuel oil
Shell heavy fuel oil "B"
(viscosity RI at 100°F - 2100 sec)
Test Procedure
152 mm x 76 mm Pyrex crystallizing dishes are filled
with 750 g of artificial sea water to a height of about 45
mm. 50 g of oil is poured onto the water and allowed to
spread over the whole surface, giving an oil film of about 3
mm thickness. 150 g of sand slurry is then scattered as
carefully and evenly as possible with a spatula over the oil
film.
Visual estimates of the amounts of oil on the surface of
the water and on the bottom of the dish are made
immediately after application of the slurry and again after
24 hours. Having noted the conditions 24 hours after the
slurry application, the oil and sand are mixed with a spatula
until the maximum possible sinking of oil is obtained. The
extent and ease of mixing are then noted. 168 hours after
mixing, the amount of oil on the surface of the water is
estimated.
All the work was carried out in a temperature (20°C) and
humidity (65% r.h.) controlled room.
The sand slurries were prepared by mixing 100 g of dry
sand with 50 g of artificial sea water containing a stipulated
type and amount of cationic wetting agent.
-------
TREATING AGENTS
APPENDIX 2
Comparison of Sinking and Retention Powers
of Various Particulate Solids
Materials Used
1. Oils
Shell heavy fuel oil "B"
(Viscosity R.I. at 100°F - 2,100 sec)
Topped Kuwait crude oil
(25% topped)
(Viscosity R.I. at 100°F - 396 sec)
2. Sinking agents
2.1 Sands
Sand No. 1 Buckland Sand & Silica Co.
Siliconized sand Midland Silicones Ltd. Barry.
2.2 Powders
Nautex H
"Craie de Champagne" Wolon Co. Ltd. Esher
Snowcal
Treated whiting Welwyn Hall Research
Association, Welwyn
Silane Treated Pulverized
Fuel Ash (SPFA) Midland Silicones Ltd. Barry
3. Surface active agents
Armac T (amine acetate salt)
Armour Hess Chemicals Ltd.
Test procedure
1. Oil sinking and retention efficiency
152 mm x 76 mm Pyrex crystallizing dishes are filled
with artificial sea water to a depth of about 45 mm. 50 g of
oil is poured onto the water and allowed to spread over the
whole surface, giving an oil film thickness of about 3 mm.
150 g of aqueous sand slurry (100 g sand, 50 g of 0.1% wt
aqueous dispersion of Armac T) or 100 g of dry sinker is
then scattered during a period of about 15 minutes, either
as carefully and evenly as possible with a spatula over the
calm oil film, or whilst the oil and water are being stirred
with another spatula.
Visual estimates of the amounts of oil floating on the
surface are made immediately after application of the
sinker. Quantitative determinations are made after 1, 7 and
14 days.
APPENDIX 3
The Sinking of Floating, Stable,
Water-in-Oil Emulsions
Materials used
1. Oils
Shell Heavy Fuel Oil "B"
(Viscosity R.I. at 100°F - 2100 sec)
Topped Kuwait Crude Oil
(25% topped)
(Viscosity R.I. at 100°F - 396 sec)
2. Sinking agents
2.1 Sand No. 1 Buckland Sand & Silica Co.
2.2 Surface active agent
Armac T (Amine acetate salt)
Armour Hess Chemicals Ltd.
2.3 Preparation of aqueous dispersion of
surface active agent
Armac T is dissolved in isopropyl alcohol (1:1
weight ratio) before being dispersed in Egham tap
water (Zeolite softened - total hardness about
3 ppm) at 0.1 %w (Armac T) concentration.
3. Sea Water
Artificial sea water was prepared as shown in Appendix 1.
1. Preparation of water in oil emulsion (mousse)
Using laboratory prepared sea water, water-in-oil emul-
sions were prepared with the topped Kuwait Crude Oil and
the Fuel Oil "B".
60 g of oil was poured into a 800 ml tall form Pyrex
beaker (175 mm high and 89 mm dia.) and stirred at a fast
rate (about 12-1300 rpm) with a three bladed downdraught
paddle stirrer (51 mm dia.). Water was added in 20 ml
batches and stirring carried out after each addition until all
the free water was absorbed into the oil and the emulsion
looked homogeneous and smooth. This procedure was
repeated until a further water addition produced a clearly
visible peripheral ring of clean, free water on the surface of
the emulsion during stirring/3)
The semi-solid emulsion was then spooned out onto the
water surface in the Pyrex test cylinder. If the emulsion
filmed out within 24 hours it was rejected.
APPENDIX 4
Adhesion Test
Materials
a. Sand
Silver-sand (particle size 50-400 micron); for sieve
analysis see Figure 1.
b. Oil
Topped Kuwait crude (25% topped).
c. Water
Natural sea water.
d. Oil-wetting agents
A l%w solution (suspension) is prepared. Mix the chemi-
cal under test with an equal volume of isopropyl
alcohol or ethyleneglycol and dilute with sea water to a
1% concentration of the oil-wetting agent.
e. Flask
250 ml Erlenmeyer flask equipped with a calibrated
25 ml tube (quickfit connection).
-------
SINKING OF SPILLS WITH PARTICULATE SOLIDS 243
Test Procedure
Weigh 50 g of the dry sand in a 400 ml beaker. Add 90
ml of sea water and mix with spatula for 1 min. Add whilst
stirring 2, 5 or 10 ml of the 1% solution of oil-wetting
agent. Mix for 3 min with magnetic stirrer. Decant super-
natent liquid. Mix remaining slurry with 30 g (33.3 ml)
topped Kuwait crude. Transfer mixture to the 250 ml flask,
install the calibrated tube and fill the flask and the tube
with sea water to the upper calibration mark. The amount
of oil in the calibrated tube after standing for 24 hours (or
less) is determined and the amount of oil retained on the
sand is given by 30 minus this amount. The results are
expressed in the form of
weight of oil sunk
weight of sand used
Remark
Suitable samples should be further tested at varying
concentrations e.g. 125, 250, 500, 1000 and 2000 ppm
agent on dry sand.
APPENDIX 5
Spraying Test
Materials
(a) Sand
Siliconized sand
(b) Oil
Topped Kuwait crude (25% topped).
(c) Water
Natural sea water (North sea).
Apparatus
(a) Size of open tank
350x 125 x 50cm depth, surface area 4,375 m2.
(b) Sprayer
(i) Consists of 12 nozzles.
(ii) 25 cm above oil level.
(iii) 16.7 cm/sec (0.6 km/hr) travelling speed.
Procedure
(a) Oil layer on water
0.5 cm thick.
(b) Composition of slurry
5.1 volume parts of natural sea water, 1 volume part
of treated sand.
(c) Treatment of sand
In a 200 litre drum 75 kg sand, 150 litres sea water
and 250, 500 or 1000 ppm of surfactant (calculated
on 100% active material) dissolved in equal amounts
of isopropyl alcohol or glycol, are intimately mixed.
(d) Impact velocity
10 m/sec.
(e) Angle of impact
10-20°
(f) Actual amounts jetted
Slurry: 35 litres in 21 sec.
Sand: 5.75 litres (15.3 kg).
Water: 29.25 litres.
(g) Actual amount of oil
19.7 kg.
(h) Sand/oil ratio
0.77.
APPENDIX 6
Fouling of Fishing Net Twines
Materials used :
1. Oils
Shell Heavy Fuel Oil "B"
(Viscosity R.I. at 100T - 2,1000 sec).
Topped Kuwait Crude
(25% topped)
(Viscosity R.I. at 100T-
396 sec).
2. Sinking agents
2.1 Sands
(a) Sand No. 1
(b) Siliconized sand
(Sand No. 2)
2.2
Powders
Nautex H
Buckland Sand & Silica Co.
Midland Silicones Ltd. Barry
Wolon Co. Ltd. Esher
Silane treated pulverized fuel
ash (SPFA) Midland Silicones Ltd. Barry
Snowcal
(Treated whiting)
Welwyn Hall Research
Association, Welwyn
3. Surface active agents
Armac T (Amine acetate salt)
Armour Hess Chemicals Ltd.
4. Sea water
Artificial sea water was prepared as shown in Appendix 1.
5. Netting twines
0.015/12 Orange polythene
Orange polythene
Manila twine
0.015/32
3/100
360 P
Ulstron twine
Tarred (90P) Ulstron twine
Bridport Gundry Ltd.
Bridport Gundry Ltd.
Bridport Gundry Ltd.
Bridport Gundry Ltd.
Bridport Gundry Ltd.
Test Procedure
1. Fouling of fishing net twines
216 mm x 76 mm Pyrex crystallizing dishes are filled to
a depth of about 45 mm with artificial sea water. 100 g of
oil, is poured onto the surface of the water and spread to
give a film thickness of about 3 mm. 200 g of dry sinker
(300 g in the case of slurries, i.e., 200 g sand and 100 g
-------
244
TREATING AGENTS
water containing the amine salt) is spread as evenly as
possible whilst the ofl and water are being stirred by
spatula.
If after 24 hours the action of the sinking agent is
complete, the surface of the water is cleaned, and the
sunken mastic is considered ready for fouling tests. If the
action of the sinker is not complete after 24 hours the dish
is rocked until most of the oil and sinker are sunk. The
remainder of ofl and sinking agent is cleaned off the water
surface before fouling tests are begun.
Fouling tests are carried out with 5 lengths of twine
which have been soaked in artificial sea water for at least 24
hours. The twines are weighed individually, after lightly
shaking off the surface water, and fitted into a 152 mm
square metal frame, which can accommodate five lengths of
twine, tautly strung in parallel, at 25 mm intervals, from
two opposite sides of the frame.
By means of its handle the frame, containing the twines,
is pressed into the oil/sinker mastic. This is repeated eleven
times, turning the frame through about 30° each time, thus
turning it full circle. In addition, to ensure most severe
conditions, oil/sinker mastic is spread over and smeared
onto the twines with a spatula. The frame is then removed
from the dish and:—
(a) allowed to drain above the dish,
(b) washed in clean artificial sea water by immersing
and rotating vigorously back and forth through
about 90°,
(c) allowed to drain until free of surface water, after
which, the twines are removed from the frame and
re weighed.
The increase in weight of the twines is calculated as g/m
and as % increase in weight.
APPENDIX 7
Size and Coalescence of Oil/Sinker Droplets
Materials Used
1. Oils
Shell Heavy Fuel Oil "B"
(Viscosity R.I. at 100T - 2,100 sec)
Topped Kuwait Crude Oil (25% topped)
(Viscosity R.I. at 100°F - 396 sec)
2. Sinking agents
2.1 Sand
Sand No. 1
3. Surface active agents
Armac T
Dispersant
Buckland Sand and Silica Co.
Armour Hess Chemicals Ltd.
An experimental laboratory-prepared formulation con-
sisting of 30% of a water insoluble long-chain alcohol
ethoxylate dissolved in a low-aromatic kerosene.
4. Sea Water
Artificial sea water was prepared with Egham tap water
(Zeolite softened — about 3 ppm total hardness) by adding
the salts as shown in Appendix 1.
INSERT APPENDIX 7
Test Procedure
152 mm x 912 mm Pyrex cylinders are rilled with 13
litres of artificial sea water. 50 g of oil is poured onto the
water and allowed to spread over the whole surface giving
an ofl film thickness of about 3 mm. 150 g of aqueous sand
slurry (100 g of sand and 50 g of aqueous Armac T
dispersion) is then scattered carefully and as evenly as
possible, during a period of 15 minutes, with a spatula over
the calm ofl surface. The dispersant, where used, is applied
onto the ofl film with a syringe immediately before sinker
spreading is commenced. The experiments were carried out
in a constant temperature room at 20° ± 2°C.
Observations on the size and the extent of coalescence
of the sunken oil/sand droplets are made and reported 1, 2
and 168 hours after the sinker application.
-------
BURNING AGENTS FOR OIL SPILL CLEANUP
Arnold Freiberger
Edison Water Quality Laboratory
Environmental Protection Agency
and
John M. Byers
Lieutenant Commander, United States Navy
ABSTRACT
The accidental spillage of oil into surface -waters contin-
ues to pox a pollution hazard as tankers and cargoes
increase in size. Burning of oU slicks offers an attractive
means of eliminating spilled oil, however, the heavier crudes
and fuel oils require the addition of burning agents to assist
in ignition and in sustaining combustion. The advantages of
burning oil slicks are set forth, and currently available
commercial burning agents are listed. Results of laboratory
and field tests of a variety of burning agents are given, and
several incidents where burning was used in an actual oil
spiH are reported. Current and future development in this
area is described.
INTRODUCTION
The threat of large spillages of oil will persist for as long
as oil tankers provide a major means of transport. The total
capacity of the world's tanker fleet doubled during the
1960's. By the middle of the 1970's as many as 5,000 oil
tankers with a total dead-weight capacity of about ISO
million tons will be plying the oceans. Modern tankers are
making increased use of new and better navigational aids.
However, tanker size is increasing; the majority of new
construction is currently of vessels in excess of 100,000
DWT, and plans for supertankers of half a million DWT are
being made. Thus, while the potential danger of tanker
accidents may decrease, those accidents which do occur will
present a greater pollution hazard because of the larger
cargoes.
Oil spilled into surface waters will, if left undisturbed, be
subject to a variety of physical and chemical actions; among
The opinions and assertions contained in this paper are solely those
of the authors, and do not necessarily represent those of the
Environmental Protection Agency or the Navy. Mention of commer-
cial product names does not imply endorsement of these products
by the U.S. Government
the former are spreading, evaporation, sinking and resurfac-
ing, and the action of winds and currents; and among the
latter are emulsification, dissolution, oxidation, and degrad-
ation. Undoubtedly these actions cause a good deal of
spilled oil to be "lost". On the other hand, some of these
same actions ultimately result in oil spills reaching shore-
lines and beaches where aesthetic and ecological damage
takes place.
There is a need, therefore, to remove or reduce the
hazard of oil spilled into the water environment. Several
methods to accomplish this, currently being investigated or
developed, include the use of skimmers, booms, and a
variety of. harvesting devices and oil-water separators, as
well as the use of dispersants, sinking agents, collecting
agents and burning agents. This paper deals with burning
agents; their description, use, and effectiveness, and their
place in the overall oil clean-up picture.
BURNING OF OIL SLICKS
Floating oil slicks are; difficult to burn in spite of the
fact that in many instances normally highly combustible
materials are involved. This is especially true if ignition is
attempted some time after a spill has occurred. With the
passage of even a short time, the more volatile, lower flash
point fractions tend to be lost by evaporation to the
atmosphere. Also, as the slick spreads it becomes thinner,
and may begin to break up and emulsify. With the volatiles
gone, ignition becomes difficult or impossible; and with
thin oil slicks, the heat loss to the water beneath is
sufficient to prevent sustained combustion.1 Reports of
some investigators indicate that floating oils on water with
thicknesses less than 3 millimeters will not burn. It has also
been reported that thin slicks of kerosene, gas oil, lubri-
cating oil and fuel oil on water will not burn at all without
a wick. The action of winds and currents also contribute
difficulties to burning by accelerating the loss of volatiles,
245
-------
246 TR EATING AG ENTS
by dissipating the heat needed to sustain combustion, by
breaking up the oil slick, and by promoting emulsification
of the oil and water.1
In spite of the difficulties, and indeed the hazards which
are obviously involved, burning does seem to offer an
attractive means of eliminating large amounts of spilled oil
in the water environment. Some of the advantages of this
method are as follows:
1. Capacity. Burning of very large quantities of spilled
oil is possible.
2. Speed. Once decided upon as desirable, a burn can be
initiated and completed within a relatively short
time.
3. Completeness. Burning offers a method which can
greatly reduce (90% or more) an oil spill. No further
collection, separation, containment or handling is
usually required.
4. Economy. The limited requirements in equipment
and manpower, and the low cost of some burning
agents, places burning among the more economical
methods for oil spill cleanup.
5. Ecology. There is no evidence, to date, to indicate
that burning has a harmful effect upon life in the sea,
even in the area directly beneath the burn. Air
pollution, by smoke plumes from burning oil could
be minimized by improved burning methods which
would consume most of the polluting exhausts.
6. Toxicity. Burning may be accomplished without the
addition of toxic or polluting materials. Most burning
agents are either inert or non-toxic.
BURNING AGENTS
Generally speaking, the term burning agent may be
defined as any material which is applied to oil to promote
its combustion either by igniting or by assisting ignition or
by sustaining combustion.'>^
Materials which ignite include such hydro-igniters as
sodium or magnesium which react with water to produce
hydrogen and heat with explosive violence and burning; and
such auto-igniters as the chlorates of sodium or potassium
which react with the carbon and hydrogen of a fuel to
produce carbon dioxide, water and heat with semi-explosive
violence.
Materials which assist ignition are generally the lighter
mineral oil fractions such as gasoline or the lighter crude
oils such as Louisiana Crude which have high vapor
pressures and low flash points, and ignite easily. Once afire
they provide sufficient heat to volatilize and ignite a heavier
crude or a Number 6. With continued application, such
light oils could also act to sustain combustion by over-
coming heat losses to the sea and maintaining the tempera-
ture of the heavier crude above its flash point.
Materials which sustain combustion are usually wicking
agents which, by virtue of their porosity and/or large
surface area, draw up the oil to provide a base from which
to burn and to furnish improved oxygen access. Examples
of wicking agents include cellulated glass beads and
common straw.
Most of the burning agents which have been tested, and
which are available either commercially or on an experi-
mental basis, are wholly or in part wicking agents; and in
general, the terms "burning agent" and "wicking agent" are
used interchangeably.
COMMERCIAL BURNING AGENTS
A review of the literature, and of the technical brochures
of manufacturers, indicates that there are currently eight
commercially or experimentally available burning agents.
These are briefly described as follows:
1. SeaBead Nodules. Pittsburgh Corning Corporation,
Pittsburgh, Pennsylvania. SeaBeads are cellulated
glass beads, approximately 1/4 inch in diameter.
(Also available in 1/16 inch diameter size and in
colors of light or dark gray.) Applied to an oil spill
they become oil-covered by capillary action. Ignition
may be accomplished by an incendiary device such as
a blow torch. The SeaBeads act as a wick to maintain
combustion of the oil. After burning, the SeaBeads
may be collected or left to break up from abrasion.
2. Cab-O-SH ST-2-O. Cabot Corporation, Boston, Massa-
chusetts. Cab-0-Sil ST-2-O is a silane treated fumed
silica. It may be applied to an oil spill in the form of
a water slurry. The water sinks beneath the oil and
the silica remains floating on top. Ignition is best
accomplished with the aid of a priming fuel such as
gasoline or lighter fluid. The Cab-O-Sil ST-2-O acts as
an oil diffuser and capillary wicking agent. After
burning, a hard sheet-like residue remains which can
be mechanically recovered. •
3. Aerosil R-972. Degussa, Inc., New York, New York.
Aerosil R-972 is a silane treated fumed silica.
Although it has not been tested as a burning agent, it
would probably function much the same as the
above-mentioned Cab-O-Sil.
4. Ekoperl. Grefco, Inc., New York, New York. Ekoperl
is a granular form of expanded perlite (silicon and
aluminum oxides), treated with a silicone to render it
hydrophobic. Primarily designed as an oil sorbent, its
use as a burning agent has been suggested, and for
this purpose it should act as a wick to maintain
combustion of the oil. Grefco recommends applica-
tion in air suspension from beneath the oil slick to
reduce dust losses in the wind. After burning, the
perlite could be removed, although residuals in the
sea should not pose a serious hazard.
5. Oilex Fire. Keltron, Inc., Switzerland. Oilex Fire
consists of Keltron's product Oilex, a sorbent, plus a
hydro-igniting chemical. Keltron reports that this
-------
BURNING AGENTS 247
product has been used on small spills in Swiss lakes
and the Adriatic Sea. The product is designed to
ignite upon application and then to act as a wicking
agent to maintain combustion. Care must be exer-
cised in storage and handling.
6. Kontax. Eduard Michels GmbH, Essen. Germany.
Kontax is a paste containing a hydro-ignitable chemi-
cal. Its effectiveness was demonstrated on a test spill
in the North Sea where 85 kg. of Kontax successfully
burned 10 tons of heavy Arabian crude.5 Care must
be exercised in storage and handling.
7. Pyraxon. Guardian Chemical Corp.. Long Island City,
New York. Pyraxon is a two component system
consisting of a liquid primer and a powder oxidant-
catalyst. According to the manufacturer, the readily
ignitable primer provides the heat necessary to begin
the combustion of oil and to initiate the catalytic
cracking action of the powder which converts the oil
to more readily combustible fractions. Once begun.
the process is said to be self-sustaining until the oil is
consumed." While both the liquid and powder are
claimed to be stable in storage, care must be
exercised in storage and handling.
8. Straw. Untreated straw and hay. and chemically
treated (hydrophobic) straw and hay. act as wicking
agents on oil slicks. The oil is drawn up onto the
surface of the straw where combustion is sustained
by increased oxygen availability. Straw is the most
readily available, as well as the cheapest, burning
agent.3 After burning, the carbonaceous residue may
be removed, although it should not pose a serious
hazard if left in the sea.
CASE HISTORIES: BURNING OF OIL AT SEA
There have been a few attempts in recent years to clean
up actual oil spills by burning, with varying degrees of
success.
1. Torrey Canyon. The "Torrey Canyon", carrying
119.000 tons of Kuwait crude oil. ran aground on the
Seven Stones rocks. Lands End. England on the
morning of March 18. 1967.7 About 30.000 tons of
oil were released into the sea. followed by an
additional 20.000 tons lost during the next seven
days. All of the burning of oil following this incident
was conducted to dispose of oil still in the vessel's
tanks. Burning of oil slicks was not carried out. and
the Torrey Canyon incident is reported here mainly
because of its historical significance in the overall
cleanup picture.
The Committee of Scientists on the Scientific and
Technological Aspects of the Torrey Canyon Disas-
ter, which first convened on March 22. 1967. may
have considered burning on the sea. but if they did,
the idea was rejected. The Committee later reported
that there was no point in trying to burn weathered
oil on the sea after most of the volatiles has been lost
and water emulsions had been formed. The need for a
burning or wicking agent, apparently unavailable at
that time, was realized by the Committee who
suggested that such wicking agents, which would
sustain combustion of oil slicks, merited further
investigation.
2. Arrow. The "Arrow", carrying 16,000 tons of
Bunker C oil ran aground on Cerberus Rock, Cheda-
Q
bucto Bay, Nova Scotia on February 4, 1970.
During the next few days, burns were conducted on
several small scale slicks using SeaBeads to sustain
combustion. The oil slick from the "Arrow" con-
sisted mostly of an iridescent film, but with occa-
sional thicker "globs" of viscous Bunker C which
measured up to 15 feet in diameter. Several of these
Bunker C patches were selected for burning, were
coated with SeaBeads, and ignited with Varsol (a
primer) and a marking flare. The results indicated
that the SeaBeads showed an ability to burn slicks of
Bunker C oil at near freezing temperatures with 15
knot winds. (Figure 1) Combustion was not com-
plete; several reignitions were necessary to achieve
50% reduction. As combustion was limited to the
Figure 1: One of several patches of Bunker C which had been
treated with SeaBeads and ignited following the grounding of the
tanker "Arrow" in Chedabucto Bay, Nova Scotia, in February 1970.
area of SeaBead application, there was little danger of
uncontrolled conflagration. It was also noted that
once ignited, the oil patches tended to spread to
thinner slicks, thus making combustion more diffi-
cult. Effective burning, therefore, may require some
sort of containment.
3. Othello. The freighter "Othello" spilled about 25,000
gallons of heavy fuel oil following a collision with the
tanker "Katelysia" in Tralhavet Bay near Stockholm.
Sweden on March 20, 1970. The passage of ships
through the icy bay in the days following the spill
tended to break-up the slick, and it was also reported
that a large amount of spilled oil moved under the
three-foot-thick ice pack. Early attempts by the
Swedish Coast Guard to bum the slick by priming
-------
248
TREATING AGENTS
with kerosene failed. Eventually, combustion was
achieved on some of the remaining oil pools with the
aid of Cab-O-Sil ST-2-0, and it was indicated that
additional pools, as well as oil released from beneath
the ice by the springtime thaw, would be systemati-
cally burned with Cab-O-Sil. The Swedish Coast
Guard has expressed satisfaction with the perfor-
mance of this burning agent and consider it an
effective technique for controlling oil-spill pollution.
EVALUATION OF BURNING AGENTS
EPA Laboratory Tests
Burning experiments carried out by EPA at the Edison
Water Quality Laboratory were conducted in outdoor
tanks with 24 square feet of exposed surface area. A No. 6
fuel oil, floating upon water in the tank, would not sustain
combustion at a thickness of 1/2 to 2/3 inches.
1. Pyraxon liquid and powder (Guardian Chemical
Company) were applied to the slick and while the
liquid ignited, no combustion of the oil could be
sustained.
2. Cab-O-Sil ST-2-0 (Cabot Corp.) was generously
applied to a similar slick and ignited. Sporadic
burning of oil ensued, but it was evident after this
burning that appreciable oil remained.
3. SeaBeads (Pittsburgh Corning) performed well on
slicks of No. 6 fuel oil. (Figure 2) Slick thickness
varied from 1/10 to 1/4 inches. Burning was quite
complete in those areas of the slick which were
completely covered with the SeaBeads. Non-treated
slick areas remained unburned. It is estimated that
the complete coverage needed for efficient burning
requires about one pound of SeaBeads per 12 to 15
square feet of oil slick.
4. Straw. A slick comprising 2 liters of No. 6 fuel oil
confined within a six-square-foot area was used.
Initially, the oil and water were cold (water tempera-
ture: 5°C, air temperature: 5°C) and the oil confined
itself to a circle measuring about 15 inches in
diameter, with a thickness of about 3/4 inches.
Approximately 80 grams of common, untreated
straw was distributed on the slick. No priming fuel
was used, and the straw was ignited with a gas torch.
Within a minute or two the oil was burning vigor-
ously. About 80% of the oil was consumed. It
appeared that the oil-soaked straw burned first to
form a closely knit web of filamentous carbon wicks
(Figure 3) which then ignited the oil and sustained
the oil burn. (Figure 4)
Figure 2: EPA laboratory burning test indicated that SeaBeads
performed well in reducing a spill No. 6 fuel oil; however, burning
only occurred where oil was covered with nodules.
Figure 3: Straw floating upon an oil slick shortly after ignition in an
EPA laboratory test. Straw burned initially to form a filamentous
carbon wicking agent.
5. Ekoperl. A slick comprising 2 liters of No. 6 fuel oil
confined within a size-square-foot area was used.
Initially the oil and water were cold (water tem-
perature: 7°C, air temperature: 8°C) and the oil
confined itself to a circle measuring about 15 inches
-------
BURNING AGENTS 249
Figure 4: About one minute after ignition (Figure 3), straw
performed well as a burning agent for a No. 6 fuel oil in the EPA
laboratory test.
Figure 5: Treating a spill of No. 6 fuel oil with Ekoperl resulted in
only about one-third oil reduction in this EPA laboratory test.
in diameter with a thickness of about 3/4 inches.
Approximately 1/4 pound of Ekoperl was evenly
distributed on the surface of the slick. Ignition was
accomplished by tossing on a rag soaked with
petroleum ether, and lighted. The oil was slow to
ignite, but once combustion was started there was a
short period of vigorous burning (Figure S) followed
by sudden extinguishment. It was estimated that only
about one-third of the oil was consumed.
EPA Field Tests
Field-scale oil slick burning tests were conducted by the
Edison Water Quality Laboratory off the coast of New
Jersey in the summer of 1970. Preliminary evaluations of
test data from these experiments indicate the following:
1. Burning of free-floating or uncontained oil slicks is
extremely difficult unless the thickness of oil is 2
millimeters or greater.
2. Adequate automated seeding methods for both the
powder and nodule types burning agents are lacking.
Spreading of the burning agents was accomplished by
hand.
3. Contained South Louisiana crude oil was successfully
burned-80% to 90% reduction-without the use of
burning agents. Bunker C could not be ignited under
these same conditions.
4. Bunker C was successfully burned-80% to 90%
reduction when the slick was seeded with SeaBeads
and a priming fuel (Figure 6). It was observed that
South Louisiana crude oil performed better as a
priming agent than did gasoline or lighter fluid.
5. Use of magnesium type flares and gasoline torches to
ignite the burning-agent-treated slick proved unsuc-
cessful. Ignition was achieved using a blow torch; care
being taken not to push aside the seeded oil so as to
expose the water surface.
U.S. Navy Field Tests
A sea test for treatment of oil spills by controlled
burning was conducted by the U.S. Navy in the North
Atlantic Ocean during May 1970. A description of these
tests, code named "SPILLEX", and an evaluation of the
test results follow.
The USS COMPTON (DD-705) arrived at about noon on
May 19th at the SPILLEX test site about 300 miles
southeast of Boston. The tests commenced at about 7:00
a.m. on May 20th.
The first phase of the mission, the testing of the
combustibility of untreated spilled oil was completed with
repeated unsuccessful attempts at ignition with an Army
flame thrower. The second phase, that of testing the
wicking action of two commercial products on spilled oil
was then attempted. Under sea and weather conditions
varying from unfavorable to good, ample testing of Pitts-
burgh Corning "SeaBeads" and Cabot Corporation
"Cab-O-Sil ST-2-O" was carried out. After various failures,
two successful burns were realized, the first being of small
-------
250 TREATING AGENTS
Figure 6: EPA field burning tests with SeaBeads pointed out the
need for automated seeding methods and for containment of the oil
slick.
size with the second producing flames and smoke of good
proportions.
It was readily apparent that the two major problems
existing were inadequate application and lack of ignition
technique. In the seeding operations Pittsburgh Coming
used an air blower unit and Cabot used a hand fed hopper
and mixing nozzle with water as the carrying vehicle. Both
systems failed to provide proper seeding or sufficient range.
Winds of 15 to 20 knots and rain reduced effectiveness of
appb'cation in initial tests, however, under improving
conditions, both systems still failed to produce satisfactory
seeding of the oil slick. Hand seeding of the oil immediately
along side the ship was finally decided on, resulting in
adequate coverage of areas approximately 4 feet wide by 30
feet in length. The two successful burns resulted from this
technique.
Ignition of the seeded oil proved to be an even greater
obstacle. Attempts at ignition by flame thrower and
magnesium flares were unsuccessful even with addition of
diesel oil and napalm as priming agents. Numerous other
types of igniters were applied, all unsuccessfully. Ignition
finally resulted after using gasoline and kerosene as primers
touched off by the flame thrower. This burn lasted approx-
imately 10 minutes and considerable oil was consumed
within the treated area (Figure 7). The wicking action of
each product was observed to be successful in the seeded oil
on a limited basis. Wind and wave dispersement of the oil
into separated pools appeared to prevent complete burning
of the treated slick.
Figure 7: Large scale burning tests were conducted by the U.S. Navy
in the North Atlantic Ocean, about 300 miles offshore, in May
1970. SeaBeads and Cab-O-Sil ST-2-O were successfully used to
reduce a quantity of spilled oil.
After one full day of experimentation, it was the
consensus of observers that further testing would prove
inconclusive with present equipment and ignition methods,
and the exercise was terminated. The following findings are
reported:
1. Bunker C oil spilled in its natural state on cold water
will not support combustion without a wicking agent.
2. The seeding methods demonstrated, and the ignition
methods attempted, are both inadequate for normal
at-sea conditions, wind and wave action being the
deterring factors.
3. Subject to satisfactory ignition methods, both prod-
ucts tested will provide a wicking action and support
combustion of cold Bunker C oil when adequate
coverage is obtained.
4. The seeded oil, once ignited, will be considerably
reduced by burning. However, wind and wave action
caused dispersement of the seeded oil into smaller
pools which separated from the burning oil and thus
did not ignite and burn. Containment of the slick by
booming appears necessary in order to alleviate this
problem and provide for a continuous burn.
The development of a combustion disposal technique for
oil continues to be considered worthwhile, particularly as it
appears to work well under cold-weather conditions and has
little or no adverse effect upon fish or the ecology of the
ocean floor.
CURRENT RESEARCH AND DEVELOPMENT EFFORTS
Burning and wicking agents have been shown to be quite
successful at reducing spilled oil in surface waters. However,
one result of both the EPA and the U.S. Navy field tests is
an indication that existing methods for the application of
-------
BURNING AGENTS 251
burning agents and the ignition of the oil are inadequate.
For example, to resort to "hand seeding" of an oil slick
during an actual spill incident would be highly undesirable,
and might very well preclude burning as an effective
method. Tests also indicate that some sort of containment
of the oil slick is essential for complete burning and
efficient use of burning agents. Another need in connection
with the use of burning agents is the reduction of air
pollution during a burn. The thick black smoke which
ordinarily rises from burning oil is due to inefficient and
incomplete combustion. Some attempts to remedy this
have been reported. A "floating incinerator" has been
tested by the British Petroleum Company and a "floating
furnace" is currently undergoing development by the
Pittsburgh Corning Corporation. Devices such as these, if
proved successful, could be used to contain and enclose the
area of burn, thus providing far greater control of combus-
tion, and hopefully a much cleaner exhaust. Used in
conjunction with systems of anchored or moving booms to
corral and thicken the oil slick, these furnaces may serve to
greatly broaden the applicability and feasibility of burning,
not only at sea, but at in-shore sites as well.
REFERENCES
1. "Oil Spill Treating Agents", Report to the American
Petroleum Institute. Battelle Memorial Institute. May 1970
2. Nelson, W. L., "Inflammability of Oil Films on the
Surface of Water", Oil and Gas J., 36 No. 52, p. 148 and
150. 1938
3. "Combatting Pollution Created by Oil Spills", Report
to the Department of Transportation, United States Coast
Guard. Arthur D. Little, Inc. June 1969.
4. Patterson, D.A., "Oil-Spill Cleanup: A Matter of $'s
and Methods", Chen Eng., 76 No. 3, p. 50-52. 1969
5. "Report concerning an experiment to destroy oil
slicks with the ignition agent 'Kontax'", Rijkswaterstaat
(State Department of Waterways), Netherlands. August
1969
6. Struzeski, E. J., Jr., and R. T. Dewling, "Chemical
Treatment of Oil Spills", Proceedings Joint Conference on
Prevention and Control of Oil Spills. New York. December
1969
7. 'The Torrey Canyon", Report of the Committee of
Scientists on the Scientific and Technological Aspects of
the Torrey Canyon Disaster. HMSO, London. 1967
8. Murphy, Thomas A., "An On-Scene Report: The
Sinking of the Tanker 'Arrow'", Edison Water Quality
Laboratory Report, U.S. Department of the Interior.
February 1970
ACKNOWLEDGEMENTS
The authors wish to express their appreciation to Rear
Admiral Joseph C. Wylie, USN, Commandant First Naval
District, for his interest and support in this work; and to
Commander James Ford, USN, Commanding Officer USS
COMPTON (DD-705) for his invaluable assistance "under
fire" during the SPILLEX Sea Tests. The authors also wish
to thank Mr. Richard T. Dewling, Director of Research and
Development, Edison Water Quality Laboratory under
whose direction the EPA field tests were performed; and
Mr. Michael Killeen who assisted in the performance of the
EPA laboratory tests.
-------
ASSESSMENT OF OIL SPILL TREATING
AGENT TEST METHODS
/. R. Blacklaw, J. A. Strand and P. C. Walkup
Battelle Memorial Institute
Pacific Northwest Laboratories
Richland, Washington
ABSTRACT
This presentation summarizes a study of currently used
laboratory methods for evaluating oil spill treating agents.
Work was performed under contract to the American
Petroleum Institute.
Treating agents were classified as dispersants, sinking
agents, sorbents, combustion promoters, biodegradants,
getting agents, and beach cleaners. The mechanisms and
chemical reactions controlling the field application of each
type of agent were defined. Parameters critical to the
evaluation of both the effectiveness and toxicity of each
type of agent were thereby identified. Present methods of
laboratory measurement were then compiled and reviewed
for the adequacy of parameter control as well as the
appropriateness of the variables measured.
It was found that no existing standardized tests are
capable of reproducibly and accurately measuring the
effectiveness or toxicity of any oil spill treating agent.
Some tests, notably those for dispersants, are amenable to
improvement such that reliable laboratory methods will
result through improved mechanical equipment,
temperature control, exposure conditions, agitation level,
reagent standardization, and selection of test biota.
The study concluded with a delineation of procedures,
equipment, and material specifications for laboratory
effectiveness and toxicity measurement. These are modified
versions of existing methods and it was recommended that
they be verified by an appropriate laboratory program.
INTRODUCTION
A variety of treating agents, equipment and methods
are available for use as countermeasures against marine
pollution from oil spillage. The organizations or individuals
responsible for preparing or implementing response
plans—sometimes in a crisis environment—must choose
among these. When such a choice is among specific treating
agents, the decision should be based on the effectiveness
and probable environmental effects of the agents for the
situation at hand. In particular, information on dosage
rates, application methods, stability, reaction times,
toxicity to humans, and toxicity to indigenous marine life
is needed in order that objective decisions can be made. The
objectives of the work reported herein were to determine
whether existing laboratory tests provide the information
required pertinent to oil spill treating agents and to develop
more appropriate methods as needed. Both standard
methods of test, e.g. ASTM Standards, and methods
employed by manufacturers, research institutions, or during
the course of oil spill cleanup activities were included.
Standard methods of test were found to be of value for
some types of agent but are not addressed to measurement
of toxicity nor effectiveness for the range of treating agents
available. This discussion is confined to these two aspects of
oil spill treating agent application.
Information on generic types, methods of application,
and physical/chemical characteristics of treating agents was
compiled from a literature review and questionnaire
submitted to manufacturers, distributors, and users of
treating agents(l ,2). This led to the classification of treating
agents as follows:
Type of Agent
Dispersant
Sinking Agent
Sorbent
Combustion
Promoter
Function
Causes formation of oil-in-water
suspensions
Creates high density compound or agglo-
merate by chemical or physical action
which sinks.
Adsorbs or absorbs oil preferentially to
form a floating mass.
Provides wick or other action for en-
hanced combustion.
253
-------
254 TREATING AGENTS
Biodegradants Oxidizes by bacterial action.
Gelling Agent Forms semisolid oil agglomerate.
Beach Cleaner Releases oil from sand, rock, etc.
Effectiveness Tests
Important parameters for laboratory effectiveness test
methods are identified in Table I. The amount and type of
agitation, temperature, water composition and quality, and
oil type are parameters which are significant for the
effectiveness evaluation of all type of treating agents.
Laboratory effectiveness tests should provide for control of
these parameters at values which correlate with actual field
conditions.
Variables which characterize "effectiveness' were
identified as: the dosage level required, the amount of
residue or untreated oil at the water surface after treatment
at optimal dosage, and the stability of the agent/oil
product. Any effectiveness test method which is developed
should be objective, i.e., it should afford a quantitative
measure of effectiveness rather than an assessment of these
variables based on judgment or visual observation. Equally
important are provisions for duplicating the sequence,
timing, and techniques generally used during field
application of the various agents.
Applicable existing tests were identified for
dispersants, combustion promoters, beach cleaners and
biological degrading agents. It was recommended that
effectiveness tests be based on these procedures, as follows,
but modified for improved control of parameters:
Most Applicable Test
Solvent-Emulsifier, Oil Slick
(MIL-S-22864A)
Burning Test-Joint Fire Research
Station (Great Britain)
ASTM Designation: D2329-65T
Biological Osygen Demand of
Industrial Water and Industrial
Waste Water
A Beach Cleaning Efficiency Test
for Solvent Emulsifiers and Other
Detergent Materials - Institute of
Petroleum (Great Britain)
General test procedures were designed for the other
types of treating agents.
Agent Type
Dispersant
Combustion Promoter
Biological Degrading
Agent
Beach Cleaner
TABLE I
PARAMETERS OF PROBABLE SIGNIFICANCE TO LABORATORY EFFECTIVENESS
TEST MEHTODS
Level and
Type of
Type of Agent Agitation Temperature
Composition
and
Oil Contact Scale
Characteristics
Solid Materials
in Contact with
Dispersant XX
Sinking Agent X
Sorbent XX
Combustion
Promoter XX
Biological
Degrading
Agent XX
Gel ling Agent XX
Beach Cleaner XX
XX
X
XX
XX
XX
XX
X
Quality Type Time Dimension Oil/Agent
XX
XX
XX
XX
XX
XX
XX
XX
XX
X
XX
XX
XX
X
X
X
X
X
X
X
X
X
X
XX
X
X
XX
XX Parameter should be controlled at several specified values.
X Parameter should be controlled at one specified value.
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TREATING AGENT TEST METHODS 255
The physical and chemical reactions of each of the
various types of agent with spilled oil are unique. Each
agent type was therefore considered individually to
delineate those laboratory procedures, experimental
apparatus, and materials which best match its use during
actual field application operations. Results of laboratory
tests, simply stated, should be the amount of agent required
per unit volume of oil, the stability of the oil-agent
product, and the amount of residue or unaffected oil left
after use of an agent at optimal dosage levels.
A detailed discussion of factors leading to these
conclusions for the most widely used agent, dispersants,
follows. Principal aspects are: the identification of
parameters which should be controlled in laboratory tests
in order to represent the expected variations in field use,
based on information from manufacturers application data,
current spill experience, and published reference works;
delineation of variables which should be measured for
assessment of effectiveness; evaluation of existing testing
methods; and recommendation of existing, modified or
wholly new testing procedures.
DISPERSANTS
Dispersants remove floating oil from water surfaces by
the formation of dispersed oil droplets. Such agents contain
surfactants, solvents and stabilizers. Surfactants promote
the spreading of oil by reducing its surface tension and
provide the chemical species necessary to form molecular
layers on oil droplets. Solvents improve the surfactant
contact with oil .(3)
The generation of oil droplets requires the application
of mechanical energy. The applied shear controls the size of
droplets produced. Within limits, the amount of shear
required to produce given sized droplets increases with
increasing oil viscosity. In the presence of a surface active
agent, the characteristics of the dispersed droplets are then
determined by the rates at which competing phenomena
occur—droplet coalescence and the orientation of the
surfactant at oil/water interfaces so as to prevent
coalescence. If the surfactant orients quickly and is present
in sufficient quantity, coalescence of droplets will proceed
to only a minor degree before they are stabilized by the
natural dilution process.
A valid laboratory dispersant test must realistically
consider these factors in addition to measuring the
quantities which define "effectiveness"—the amount of
agent required relative to the amount of spilled oil (dosage
level), the completeness of oil dispersion, and the stability
of the dispersion.
Agitation and Mixing
The efficiency of virtually every dispersing agent
benefits from agitation and mixing. Some oils can be
dispersed in water without the addition of dispersants if
enough mechanical mixing energy is applied. Most
dispersant manufacturers recommend mixing their products
with floating oil slicks by means of high pressure spraying
systems or boat propellers. Some state that mixing is
mandatory, particularly for dispersing heavy viscous oils(2).
Mixing by natural phenomena occurs by the actions of
waves, winds, and currents. The forces exerted on floating
materials by waves are theoretically normal to the water
surface—whether they be on wave crests, troughs, or
intermediate locations-provided the waves are not
breaking. Non-breaking waves would be expected to
contribute little surface energy for mixing purposes. The
more important element, for mixing of floating materials,
would be the energy transfer from air currents (winds) to
the water surface. The mechanisms and explanation of the
transfer of energy from winds to water surfaces are
complex and poorly understood. However, an empirical
approach may be used relating field data on wave
characteristics (height, period, and velocity) to wind
velocity and duration. Total wave energy can be calculated
from wave characteristics. Then the rate of energy transfer
may be computed as a function of wind speed. Data
compiled by Wiegel(4) was treated in this way.
Mixing energy imparted to floating slicks by currents
would be quite limited unless surface water velocities were
great enough to produce turbulence. During the vast
majority of the time in offshore waters this would not be
the case. Once a slick is partially dispersed beneath the
water surface, the effects of water currents would be to
further disperse and dilute suspended oil.
The energy input from spray systems may be estimated
from typical spray system arrangements and operating
conditions. Mixing energy levels from spray vessel
propellers may be estimated based on typical work boat
dimensions and operating speeds.
The data developed for mixing energy inputs from
winds, spray systems, and boat propellers are summarized
in Table II, following. If one takes as an "average"
condition about a ten knot wind with the application
methods as specified, then the total estimated effective
mixing energy per unit area would be about 7.7 ft Ib/ft2.
For calm conditions, the energy input would be about 4.1
ft Ib/ft2. Effectiveness laboratory testing methods should
control the mixing energy input to a similar energy input
range and tests should be performed at the two
values—representing the normal minimum and maximum
energy inputs.
Temperature
Data on the effects of temperature variation on oil
dispersant efficiency are sparse. Work by Zitko and
Carson(5) on the efficiency of two dispersants on Bunker C
shows that, for one predominantly water soluble dispersant,
efficiency decreases with increasing temperature and for a
predominantly oil soluble agent efficiency decreased with
decreasing temperature. Although the data are difficult to
interpret it would appear that the required dosage to
disperse a fixed quantity of Bunker C varied by up to a
factor of three over the temperature range of 5 to 20°C.
Additional support of the significance of temperature
variations on dispersant agent efficiency are the statements
by some manufacturers that their dispersants have reduced
effectiveness at lower temperatures(2).
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256 TREATING AGENTS
TABLE II
ESTIMATED SURFACE ENERGY INPUT FROM VARIOUS PHENOMENA FOR DISPERSANTS^
Mixing Energy by Winds
Assumptions:
(1) Deep water
(2) Energy input is charac-
terized by average of the
1/2 highest waves.
(3) At the end of one hour,
all dispersants would be
diffused into water and
mixing would no longer
be important o
Mixing Energy from Spray
Systems
Assumptions:
(1) Spray system with five
nozzles per header.
(2) Two headers
(3) Flow rate of 2 gpm per
nozzle at 50 psi discharge
Pressure.
(4) Speed of travel - 10
knots.
(5) One pass covers 50 ft. of
width (two headers).
Mixing Energy from Propeller
and Wake
Assumptions:
(1) Application boat 25 ft.
long by 10 ft. beam.
(2) Two 20 ft. long spray
headers.
(3) Speed of 5 knots.
(4) One pass covers 50 ft.
width.
Wind Velocity Mixing Energy
(knots) (ft Ib/ft2)
2
5
10
20
30
40
0.0258
0.426
3.63
30.6
100.7
264.5
Mixing Energy
(ft Ib/ft2)
0.212
Mixing Energy
(ft Ib/ft2)
3.9
Temperature changes could affect the rate of
interaction between materials by altering the interfacial
tension, adsorption rate of the surfactant and the viscosity
of all components (agent, oil, and water). An increase in
temperature will reduce interfacial tension and viscosity
and will permit a more rapid dispersion rate.
Other temperature dependent effects, theoretically
capable of changing the efficiency of dispersants include
the possibilities that low temperatures could cause the
solubility of the surfactant in the petroleum diluent to
decrease to the point where it precipitates. Also, high
temperatures could cause accelerated evaporation of the
diluent to the point where the surfactant precipitates.
However, the solubilities and concentrations of surfactants
in most commercially available dispersants would preclude
such effects.
In addition, the relatively greater rate of change hi oil
density with respect to water density as temperature is
increased may enhance dispersed droplets movement
upward and concentration at or near the surface. Such
"creaming" is observed in static oil-water dispersions. The
net result would be a decreased dispersant effectiveness at
high temperature.
The range of temperature expected in the majority of
spill situations and the characteristics of most dispersant
agents suggests that laboratory effectiveness tests
performed at a predetermined fixed temperature range
which is representative of field application situations (say,
40 to 70°F) would adequately treat the temperature
dependance of agent effectiveness.
Water Quality Characteristics
Water quality characteristics can be expected to affect
the performance of oil spill treating agents both directly
and indirectly. The meager information available on the
effects of water quality on the performance of dispersants
shows that measurable differences in reaction time and
stability of oil-agent mixtures are attributable to water
quality changes.
Oda performed tests using Polycomplex A-ll to
determine the effects of salinity on emulsification
efficiency. Comparison of the results showed that the best
dispersion in test samples occurred at the higher salt
concentrations/^)
Sea water is a mixture in which many reactions, which
are understood for fresh water, either do not occur or may
be modified. As evidence of this PerkinsC?) calls attention
to an apparent pH depression, which he attributes to a
micelle effect, observed when detergents were added to sea
water, which did not occur in the case of fresh water.
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TREATING AGENT TEST METHODS 257
One British technique(S) for determining the
effectiveness of various detergents in treating oil spills
involved the measurement of interfacial tensions, since a
reduction in tension is a requisite to achieving good
dispersion characteristics. Adam(9) states that "most salts
raise the surface tension of water almost linearly with
increasing concentration," which is indicative that
interfacial tension of oil-agent mixtures may well be a
function of salinity. No references were found regarding
investigations of this nature, although an earlier cited
referenced) also discusses other phenomena, such as the
reversal of oil-in-water emulsions, that might in part be
attributable to changes in salt concentrations.
The information available relative to the effects of
water quality on oil-spill treating agent efficiency indicates
that some quality considerations, particularly salinity, may
be of concern. Other parameters probably have a
significantly lesser effect.
It is concluded that minimum requirements for
appropriate laboratory effectiveness tests must include both
simulated fresh and sea waters. Fresh water should be
representative of the hardness of natural waters. Simulated
sea water should contain the significant ion species present
in natural sea water at appropriate average concentrations.
Oil Type
The variation of dispersant efficiency with different
refined petroleum products and crude oils is shown by the
work of Oda and EngOO). Dispersants were applied to
simulated spills of seven crude oils and three fuel oils under
otherwise identical conditions. Although no quantitative
findings were reported, the efficiency of each of the five
dispersants evaluated varied with the type of oil. Generally
the dispersants were most effective on the refined products
and least effective on high viscosity crude oils. In addition,
many manufacturers state that their dispersant agents are
less effective on heavy fuel oils or weathered crude oil than
on fresh crude oil or light fuel oils(2).
Variations in the efficiency of a dispersant on different
oils are attributable to the chemical species comprising the
oil, the physical characteristics of the oil (viscosity, surface
tension, and density), or the presence of surface active
agents in the oils,(ll)
It is clear that the most definitive laboratory dispersant
effectiveness test would utilize the material actually spilled
in the incident of concern and this material would be in the
identical condition as it exists on the water surface. The
possibilities of evaporation, weathering, and water-in-oil
emulsification (the infamous chocolate mousse) are
examples on condition variations. Such "tailoring" of
effectiveness tests is not compatible with a general
dispersant effectiveness test. Even if this were feasible, it is
impossible to obtain a representative sample of an oil
slick-due to the changes occurring within the slick with
time and the probable nonuniformity. of large slicks. The
preferred approach would be to design the testing methods
to be compatible with a variety of potential oil types.
Specified fresh and conditioned oils, which represent the
range of physical and chemical characteristics of potential
spill materials, could then be used to evaluate the
effectiveness of the dispersant. A representative listing
would be
• Low gravity—high viscosity refined product (such as
Bunder C Fuel)
• Fresh low gravity crude oil
• Fresh high gravity crude oil
• Weathered crude oil
Refined light products, such as gasoline, jet fuel, and
diesel fuels, are not of serious concern because their high
evaporation and spreading rates cause dissipation before
dispersants could be applied in most spill situations.
Scale Effects
Dimensional characteristics of oil slicks could
conceivably cause variance between dispersant effectiveness
in the actual spill and laboratory situations. For example,
(a) the presence of an unlimited amount of water beneath
the slick in the field situation promotes leaching of the
agent from a dispersion or allow useless diffusion of the
agent into the water which would not occur in the
laboratory, (b) restraint of the oil slick in the laboratory,
due to relatively large quantities of oil in small test vessles,
could falsely enhance the efficiency of an agent in
comparison to the field where spreading was unrestrained,
and (c) a high ratio of oil and dispersant volumes to water
volume in the laboratory might wrongfully favor a
dispersant whose hydrophilic-lipophilic balance happens to
correspond to the laboratory situation.
These possibilities have not been investigated and the
impact of scale effects is not known. However, common
sense would suggest that laboratory effectiveness test
procedures employ large ratios of water to oil and water to
dispersant. Furthermore, sufficient surface area should be
provided so as to not restrain the oil slick.
Contact Time
Many manufacturers recommend that their dispersant
be applied to an oil slick and agitated after a waiting period
ranging from 3 to 15 minutes(2).
Murphy reported work in which the contact time was
varied from one to ten minutes in tests of four nonionic
dispersants. It was found that the change in fraction of oil
dispersed over this range of contact time varied from zero
to a factor of three 12).
Signigicant as "contact time" may be in the laboratory,
field environmental conditions and application methods
(pressure spray systems mounted on propeller driven boats
which are driven through slicks) generally cause mixing
agitation during or immediately after dispersant
application. Contact times on the order of minutes are
possible for only very small spills.
In conclusion, it is recommended that the following
parameters be controlled during laboratory effectiveness
testing:
Agitation and Mixing - Based on energy input due to
natural mechanisms and application methods. Range
from 4 to 8 ft Ib/ft2.
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258 TREATING AGENTS
Temperature - Based on expected sea temperature
extremes. Range 40 to 70°F.
Water Quality - Based on expected spill sites. Range
from fresh water to sea water.
Spilled Material - Based on range of potential spill
products and materials. Range from Bunker C fuel oil
and weathered crudes to fresh crude oil.
Contact Time - Should match field condition as
closely as possible with some mixing and agitation
immediately after application of the dispersant.
Scale Effects - Large ratios of water to oil and water
to dispersant volumes should be used. Large surface
area should be provided so as not K- restrain floating
oil from spreading.
These are listed as partial criteria by which to judge the
adequacy of existing effectiveness laboratory tests. It
remains to identify the performance characteristics to be
meausred to define "effectiveness."
Dosage requirements and completeness of dispersion
can be ascertained by two basic laboratory approaches:
a) Add a standard amount of dispersing agent to a
standard oil slick and determine the fraction of oil
dispersed. Compute the amount of agent required to
disperse a unit quantity of oil.
b) Add idspersing agent to a standard oil slick until the
oil is completely dispersed. Compute the amount of
agent required to disperse a unit quantity of oil.
In the field application situation, an attempt is
normally made to estimate the amount of oil spilled and
the area of the oil slick. Dispersants are then applied at a
rate calculated to disperse the oil within the constraints
imposed by regulatory authorities such as proximity to land
or sensitive resources and allowable dispersant
concentration levels. Neither of the two possible laboratory
methods outlined relates well to the field situation; method
(a) would measure the required dosage only where there is
always an excess of oil; method (b) would integrate the
dosage over the range of relative concentrations from a
great excess of oil (at the beginning of application of the
agent) to the point where the agent and oil are equilibrated
for dispersion formation. Both methods would tend to
overestimate dispersant efficiency in comparison to the
field situation.
Other complications occur because dispersing capacity
is probably not a linear function of dispersant dosage
(volume of dispersant/volume of oil). Data developed by
Zitko and Carson(5) indicate approximately a first order
exponential relationship between emulsifying effect and
dispersant dosage level for experiments involving Corexit
7664 and XZIT dispersing Bunker C oil in salt water.
It is concluded that no one method of measuring
required odsage rate in the laboratory is likely to correlate
well with field application results. The most reasonable
alternative is to add the dispersing agent to the floating
slick in "batch" doses at several levels of concentration.
One test would be at the manufacturer's recommended
dosage rate (ranges from 1:10 to 1:1 agent volume to oil
volume), a second test at approximately half the
recommended ratio, and a third at a fixed dosage level (say,
5 parts oil/1 part dispersant). The average of the results, in
percent of oil dispersed, would be representative of
performance,
Stability meausrement will determine whether
coalescence or breakdown of an oil-in-water dispersion will
occur under the conditions of the field application. Such
dispersion must remain stable until dilution or separation of
oil droplets effectively prevents coalescence. Natural
diffusion effects of the droplets and perturbations such as
currents and tides would accelerate the dilution process.
The amount of dilution, or separation of droplets,
necessary for stability depends primarily on the nature of
the surfactant—dimensional structure (ability of dispersed
droplets to "fend off* collisions), ionic characteristics of
hydrophilic portion of surfactant (ability to form inoic
charges for electrical repulsion between droplets), and the
ability of the surfactant to form densely packed surface
films of relatively high strength. The size of the droplets
and distribution of droplet sizes are also critical to stability
and the natural tendency for hydrostatic rise of the oil to
the surface (creaming).
The previously cited work by Zitko and Carson
provides some insight as to the kinetics of coagulation of
emulsions of Bunker C dispersed by use of two dispersants.
Their work shows that coagulation is most rapid during the
first hour after stopping agitation.
It is concluded that the dearth of information
regarding oil droplet diffusion in spill situations does not
permit a meaningful conclusion regarding minimum
acceptable dispersion coalescing times. However, if the
dispersion generated in the laboratory is stable for a few
hours, the subject agent would be expected to perform
adequately in the field. Such a procedure involving periodic
analysis of samples from a static dispersion or from a
dispersion agitated at levels consistent with natural
conditions should be incorporated in effectiveness test
procedures.
The test which best meets the previously developed
criteria is entitled "Solvent-Emulsifier, Oil Slick,
MH-S-22864A, 24 February, 1969." Refinement and
modification of the specified equipment and procedures are
expected te result in a reliable and reproducible dispersant
effectiveness test method. Additional features should
include:
• Provisions for more appropriate forms and levels of
agitation. The reference test provides approximately
600 ft Ib/ft2 of surface energy input, two orders of
magnitude greater than levels of mixing expected in
field applications.
• Equipment for performance of tests over a range of
temperatures.
• Detailed specification of petroleum products and
water quality characteristics.
Toxicity Tests
Review of recent literature on the TORREY CANYON
incident(13) and othersO^) reveals information on toxic
-------
TREATING AGENT TEST METHODS 259
effects of oil spillage and oil spill treating agents, separately
and combined. From this information and from knowledge
particular to spill materials, agent properties, water quality
and other pertinent properties, the important ecological
manifestations of an oil spill are determined contingent
upon the particular biological, meteorological and
hydrographic environment considered.
The major toxicity test types which are necessary to
evaluate ecological impact are thus determined. Laboratory
experiments verify that toxicity is largely restricted to
volatile fractions; however, there is evidence of the
long-term effect on certain organisms tested which
manifested itself 12 days after exposure to sublethal
concentrations. 03) it is, therefore, important to include a
sublethal or long-term test to determine the effects of
persistent fractions of chemical agents in combination with
"standard" oil spill materials. Also indicated was a need to
evaluate the sensitivity of embryonic or larval stages of
invertebrates and fish, as destruction of such populations
are likely to have severe long-term effects in terms of
depletion of commercial and recreational fisheries.
Although it is stated that use of dispersants is desired
to aid in the decomposition of oil on beaches03) little
definitive information is available comparing rates of
degradation either in the presence or absence of treating
agents. It is quite possible that persistent fractions of
dispersants can retard biological decomposition. Sinking of
oil deeply into the sediments, where oxygen necessary for
aerobic processes of degradation is rapidly depleted and not
readily renewed, and where the toxic fractions of dispersant
mixtures are retained in the absence of evaporative
processes may account for the persistence of oil and
dispersant mixtures observ ed on numerous beaches months
after the TORREY CANYON disasterX13) These
observations justify the requirement of a biodegradation
toxicity test, because of apparent toxic effects upon
free^loating and interstitial degradation organisms and
because of an increased time span associated with the
persistent toxic fractions in the presence of suppressed
microbial populations.
The process of intermittent exposures implied by the
field studies of oil and beach or bottom deposit
interaction^13) (mechanical wave and wind action in
scouring such deposits and oil/treating agent stability), are
important because of the chronic exposures to local
organisms. Such exposures may have drastic effects upon
resettlement and recolonization of the benthic environment
and must therefore be considered a necessary toxicity
determination.
ObservationsO3) of shoreline and offshore
environments indicate a broad range in organisms affected
by surface oil and treating agents applied to such slicks.
Therefore, protection of aquatic life must reflect the effects
of the most sensitive species present. Due to the variation in
possible spill environments, a diverse set of test organisms
representing different trophic levels and for different
regional specie diversity must be used to produce credible
and quantitatively significant results.
These and other aspects justify the following test types
as being necessary and sufficient to evaluate biological
effects: acute toxicity, sublethal toxicity, field evaluations,
toxicity to humans, biodegradation and tainting.
Known variables affecting toxicity test results were
identified; varialbes particular to oils characteristics, agent
mechanisms and properties and water quality variable were
also examined. These were then scrutinized to determine
the sensitivity of the variables.
Significant parameters to toxicity tests were chosen
and are included in Table III. Oil type (stability and
volatility), ionic state and oil/agent properties),
temperature, dissolved oxygen in the test medium, pH,
alkalinity and hardness of the test waters, salinity,
synergists and test organisms were chosen. Sensitivity of
each test type with these parameters isimplied in Table III
by way of the degree of control required for the particular
test.
Bioassays are generally alboratory attempts to
duplicate typical and actual field conditions such that the
results obtained are indicative of a realisitc and meaningful
assessment of potential detriment to the environment. For
the most part, all that is required for bioassay is a water of
satisfactory quality for existence of test organisms, a source
of waste or chemical toxicant, and a supply of healthy test
organisms.05) .
Current bioassay procedures either fail to recognize the
effects of chemical composition of the toxicant,
temperature, pH, oxygen, the presence of other pollutants,
and the relative sensitivity of organisms selected for test, or
if recognized, provide only a means of obtaining
comparative data using the same source of water or diluent
and neglect reporting the assessment of such factors! 15)
Failure to report these variables results in much conflicting
data which are not easily reconciled.
Because of special problems arising in testing of oil,
chemical agents, and oil-agent mixtures, special effort was
made to elucidate the possible effects upon toxicity
measurement of failure to control such intrinsic factors.(0
Evaluation of current methods of bioassay conclusions
resulted in the following conclusions:
(1) Acute Toxicity Measurement The widely used static
bioasay, from which most available toxicity data are
derived, is a measure of relative toxicity and should
not be used to determine absolute values.
(2) Sublethal Toxicity Measurement Although the trend
in recent years in pollution research is aimed at
sublethal effects rather than purely lethal conditions,
none of the standard bioasay methods provide this
investigative capability. Generally, the detection of
such effects requires testing over a long time span;
weeks, months, or years. Tests which encompass such
time frames are impractical for routine
testing-"short cut" methods must be developed.
(3) Field Tests No rapid, meaningful field test exists.
Existing tests give only an approximate toxicity. The
major difficulty is in defining the concentration of
pollutant in the test water.
(4) Toxicity to Humans Toxicity from inhalation should
be tested in addition to existing tests based on oral
ingestion and eye irritation.
-------
260 TREATING AGENTS
TABLE III
PARAMETERS OF PROBABLE SIGNIFICANCE TO TOXICITY TESTING METHODS
Agent
Properties
and Alkalinity
Type of Oil Applications Dissolved and Test
Toxicity Test Type Method Temperature Oxygen Hardness Salinity Synergists Organism
Acute
Toxicity
Sublethal
Toxicity
Field Tests
xx
XX
XX
Toxicity to
Humans XX
Biodegrad-
ability XX
XX
XX
XX
Tainting
XX
XX
XX
XX
XX
NC
X
XX
X
XX
NC
NA
XX
X
X
NC
X
XX
X
XX
XX
XX
XX
XX
X
NC
X
X
XX
XX
XX
X
X
XX
XX Parameter should be controlled at several specified values.
X Parameter should be controlled at one specified value.
NA Not applicable.
NC No control possible.
(5) Biodegradability Biodegradation of oil and treating
agents occurs to an appreciable degree. T here is
evidence to suggest that in certain situations the rate
of degradation may be depressed by environmental
factors and the persistent toxic fractions of both oil
and chemical agent. Currently used test procedures
are adequate to measure biodegradation.
(6) Tainting Current practice of both management and
regulatory agencies provides that substances that
produce undesirable tastes and off-flavors in
commercially important species should not be present
in concentrations above those known to be accepted
by bioassay and taste panels. Since this procedure is
not highly objective, development of a more
appropriate technique is indicated.
Test procedures were recommended for each toxicity
test type but are so lengthy and diverse in nature that they
will not be included (See Reference 1) but will only be
listed in reference form in Appendix A.
Test development of these recommended tests is
suggested in order to ascertain their relevance to the oil spill
and treating agent biological effect. Particular deficiencies
which are apparent and deverse experimental evaluation are
summarized:
• Specification of test oils and water quality criteria is
needed.
• Evaluations by region, of "valued" biota potentially
vulnerable. (Sensitivity checks and choise of test
psecies) is required.
• Laboratory evaluation of the recommended
sensitivity of controlled variables and subsequent
selection of detailed test procedures. Of particular
emphasis should be development of sublethal test
procedures on marine algae and plankton and upon
embryonic and larval stages of fish and shellfish.
REFERENCES
1. P.C. Walkup, J.R. Blacklaw, J.A. Strand and
B.C. Martin. "Oil Spill Treating agents, Test
Procedures: Status and Recommendations," by
Battelle-Northwest for American Petroleum Institute
Committee for Oil and Water Conservation Research
Report. May 1,1970.
2. P.C. Walkup, J.R. Blacklaw and C.H. Henager.
"Oil Spill Treating Agents, A Compendium," by
Battelle - Northwest for Aermican Petroleum
Institute Committee for Oil and Water Conservation
Research Report. May 1,1970.
-------
TREATING AGENT TEST METHODS 261
3. "A Status Report on the Use of Chemicals and
Other Materials to Treat Oil Spilled on Water,"
Northeast Region Edison, New Jersey, Federal Water
Qaulity Administration. 1969.
4. R.L. Wiegel. "Oceanographical Engineering,"
Prentice-Hall, Inc., Englewood Cliffs, New Jersey.
1964.
5. V. Zitko and W.G. Carson. "Bunker C Oil
Dispersibility in Water by Corexit and Xzit at
Different Temperatures," Manuscript Report, Series
No. 1043, Fisheries Research Board of Canada,
Biological Station, St. Andrews, N. B. October 1969.
6. A. Oda. "Evaluation of Polycomplex A-ll as
an Oil Dispersant," Research Paper No. 2020, Ontario
(Canada) Water Resources Commission. June 1968.
7. E.J. Perkins. "Some Properties of Detergents
in the Marine Environment," (in press), Chemistry
and Industry (UK). 1969.
8. C.E. Carpenter, et al. "Laboratory
Examination of Materials for Treating the Torrey
Canyon Oil Spill," Admiralty Oil Laboratory Report
No. 5 I.January 1969.
9. N.K. Adam. "The Physics and Chemistry of
Surfaces," 3rd Edition, Oxford University Press.
1941.
10. A. Oda and P. Eng. "A Report on the
Laboratory Evaluation of Five Chimical Additives
Used for the Removal of Oil Slicks on water,"
Ontario (Canada) Water Resources Commission.
August 1968.
11. G.P. Canaveri. "General Dispersant Theory,"
API-FWPCA Joint Conference on Prevention and
Control of Oil Spills. December 15-17, 1969.
12. T.A. Murphy. "Evaluation of the
Effectiveness of Oil-Dispersing Chemicals,"
API-FWPCA Joint Conference on Prevention and
Control of Oil Spills. December 15-17, 1969.
13. J.E. Smith (Editor. "TORREY CANYON
Pollution and Marine Life," Rept. Plymouth
Laboratory, Marine Biological Association of the
U.K., Cambridge at the University Press, 196 pp.
1968.
14. W.H. Swift, et al. "REview of Santa Barbara
Channel Oil Pollution Control Administration and
U.S. Coast Guard, DAST 20. July 1969.
15. D.I. Mount. "Consideration for Acceptable
Concentrations of Pesticides for Fish Production,"
Symposium on Water Quality Criteria to Protect
Aquatic Life, September 1966, American Fisheries
Society, Spec. Pub. No. 4.
Appendix: Suggested Toxicity
Test Methods
Test No. Reference
1 Standard Methods for the Examination of Water
and Waste Water Including Bottom Sediment and
Sludges 1965 12th Ed. APHA, Inc., New York. pp.
457-473.
2 U.S. Dept. of the Interior 1969. Interim Toxicity
Procedures. Federal Water Pollution Control
Administration.
3 J.E. Smith (Editor, "1968 Torrey Canyon
Pollution and Marine Life." A report by the
Plymouth Laboratory of the Marine Biological
Association of the United Kingdom, Cambridge at
the University Press.
4 Ibid
5 A.D. Boney. 1968 Experiments with Some
Detergents and Certain Intertidal Algae. In: The
Biological Effects of Oil Pollution on Littoral
Communities 1968 Symposium Proc. Field Studies
Council, London, United Kingdom.
6 J.M. Baker. 1969 The effects of Oil Polution on
Salt-Marsh Communities. In: First Annual Rept.
Field Studies Council, Oil Pollution Research Unit,
Orielton Field Centre.
7 Ibid.
8 H.B. Tracy, R.A. Lee, C.E. Woelke and G.
Sanborn. 1969. A Report on the Relative
Toxicities and Dispersing Evaluations of Eleven
Oil-Dispersing Products. State of Washington
Water Pollution Control Commission, State of
Washington Department of Fisheries.
9 Personal Communication, Enjay Chemical
Company, New York
10 Ibid
11 Goldacre, R.J. 1968 Effect on Detergents and Oils
on the Cell Membrane. In: The Biological Effects
of Oil Pollution on Littoral Communities. 1968
Symposium Proc., Field Studies Council, London,
United Kingdom.
12 Manual on Industrial Water and Industrial Waste
Water 1965 2nd Edition ASTM Special Tech. Pub.
148-H Philadelphia, 809-817.
13 W.W. Umbreit, R.H. Burris, and J.F. Stauffer
Manometric Techniques. Burgess Publishing Co.
1959.
14 Surber, E.W., English, J.N., and G.N. McDermott.
Tainting of Fish by Outboard Motor Exhaust
Wastes as Related to Gas and Oil Coksumption.
1965 In: Biological Problems in Water Pollution.
1962 Seminar, Trans. P.H.S. Publication
999-WP-25 (Robert A. Taft Sanitary Engineering
Center, Cincinnati, Ohio).
-------
OIL SPILL DISPERSANTS - CURRENT
STATUS AND FUTURE OUTLOOK
Gerard P. Canevari
Esso Research & Engineering Company
ABSTRACT
{The use of chemical dispersants for the handling of oil
spills has had a brief but highly turbulent history. Despite
extensive laboratory data and field application experience,
their role in oil spitt cleanup is still controversial "3
This paper reviews some of this past history as
background in order to derive the pros and cons regarding
their use. Opinions vary from an extreme of no use
whatsoever to an acceptance of this as the only practical
technique to combat an oil spill under rough sea conditions.
Improvements in the formulation of dispersants during
the past several years are reviewed. These innovations
involve modifications to improve effectiveness, application
techniques and toxicological properties. A brief outline of
the mechanism of dispersing is presented to permit a better
understanding of these formulation modifications and the
manner in which said changes influence dispersant
properties.
The future outlook for dispersants, based on current
and anticipated research in this field, is also discussed. This
research involves biological as well as operational aspects of
dispersants.
INTRODUCTION
It is not possible, in a discussion of this subject, to
separate the surface chemistry aspects, i.e., mechanism of
dispersing, relative effectiveness of various formulations,
application techniques, from the environmental aspects,
i.e., ecological effects of dispersing oil. Indeed, most recent
decisions regarding the advisability of using dispersants have
been based on ecological rather than
operational/effectiveness considerations. Further, these are
state regulations that now base the amount of chemical
dispersant that can be applied on the dispersant's toxicity.
Therefore, both the biological and operational aspects
of the extensive laboratory effort and field applications
during the past 2-3 years are reviewed in the following
development of the subject.
•The perspective of chemical dispersants in the general
subject of oil spills.
•The advantages and disadvantages of their use.
•The relationship between dispersant effectiveness and
toxicity.
Why Even Consider The Use of Chemical
Dispersants?
In view of the current restrictions and concerns
regarding the use of chemical dispersants (and to put the
subject in the correct perspective at the outset), it is in
order to consider the total subject of Oil Spill Handling and
Control. In this regard, prevention of spills is always the
first consideration. The major effort in the industrial and
governmental communities has been directed toward this
end.
After a spill has occurred, containment and physical
removal is the recommended procedure. It is, of course, the
most complete solution to the problem. If spill booms, oil
sorbing agents and associated recovery hardware were an
effective and viable solution under all field conditions
encountered, there would be no justification for
considering the use of a dispersing agent that permits the oil
to remain in the environment. Unfortunately, however, the
present state of the art restricts the effective range of
application of containment booms to rather quiescent
conditions, i.e., seas not exceeding approximately two feet
or currents less than about two knots. A concise summary
by DewlingO) made in September 1970, indicated there are
at least 37 different known designs of containment booms
ranging from $5 to $45 per foot. In addition, the first few
hours after a typical spill are critical and the deployment of
booms is time consuming. It must be emphasized, however,
that there is extensive research underway to extend the
capability of these devices.
263
-------
264 TREATING AGENTS
Clearly then, situations can and do arise wherein the
spill cannot be recovered because of the above-cited
limitations. There are two courses of action now available;
in one case, the oil may be permitted to remain as an intact,
cohesive slick on the surface of the water and possibly
reach and contaminate the shore. For the alternate case, the
oil spill may be treated — with such treatment directed
toward removing the oil from the water surface by the
formation of an oil-in-water dispersion. It can be noted that
in either case the oil contaminant is not removed from the
marine environment. Thus, the perspective for such treating
techniques is that of a last resort approach, i.e., attempting
to minimize the detrimental effects of an undesirable
situation.
An Untreated Oil Spill Can Cause Ecological
As Well As Monetary Damage
On order to evaluate under what conditions, if any, it
may be advantageous to disperse an unrecoverable spill, the
resulting damage that might otherwise occur should first be
considered. From the hard, intensive look directed at this
subject during the past five years, these debits might be
summarized as follows: ^^<^-
1. Shore contamination by beached oil represents biologi-
cal as well as property damage. The damage to the inter-
tidal region resulting from an untreated, intact, cohesive
layer of oil is visually apparent and particularly distres-
sing. It encompasses both biological and property
damage. The very large extent of the property damage is
evident from the amount of the lawsuits following an oil
spill undertaken by tourist interests, property owners,
etc. In addition, the cleanup costs for a typical, large
spill in a valued resort area can be several million dollars.
This is also the most publicized aspect as can be readily
appreciated by extensive magazine articles as typified by
Life Magazine 2,3 . These publications covered such
spills as Santa Barbara, Tampa Bay, San Francisco Bay,
Gulf of Mexico in a popular style complete with the
appropriate photographs of oil stained beaches and
shore property. However, even in this non-technical
treatment of the subject, biological damage due to a
physical smothering effect on some intertidal organisms,
such as mussels, barnacles, crabs, etc., can be readily
seen.
The effects of untreated oil coming ashore was well
documented in a scientific manner by Blumer et at.4
In September, 1969, a spill of highly aromatic fuel oil
from the barge Florida in Buzzards Bay was
incorporated into the bottom sediment to at least 10
meters of water depth. This illustrates very well the
wetting effect of untreated spilled oil and its ability to
cling to shore surfaces. In this instance, the oil was
physically dispersed by the heavy seas but retained its
adhesive characteristics. It is postulated that the oil
droplets came into contact with and wetted the sand
particles that were temporarily suspended in the
turbulent water column. Additional spill incidents that
have cited instances of oil incorporated into the
sediment have been reported by Murphy 5 . in the
above instances, there has been a significant kill of all
marine life in the area, particularly where a highly
aromatic product, such as some distillate fuels
containing cracked components, was the contaminant, as
.distinguished from whole crude oil.
Finally, in instances where there has been a sub-lethal
exposure to the oil spill, the physical coating of marine
life such as lobsters with small amounts of oil, though
conceivably harmless, causes tainting and commercial
loss.
2. Marine fowl, especially diving birds, are particularly
vulnerable to an oil spill. Nelson-Smith 6 has analyzed
the cause as mechanical damage; the oil penetrates the
plumage that normally provides water-proofing and heat
insulation. As an example, an oil-contaminated bird at
an ambient temperature of +59°F is stressed to the same
degree as a healthy bird at -4°F. McCaull 7 has cited
some statistics, e.g., more than 25,000 birds, mostly
guillemonts and razorbills, were killed after the Torrey
Canyon spill.
3. Persistent tarry agglomerates are formed as the spilled
oil weathers at sea. There is mounting concern regarding
the presence of tar-like globules at sea. This persistent
material is believed to represent a 10-15% residue of a
larger volume of cohesive crude oil. During the voyage
of Thor Heyerdahl's papyruts boat, RA, Bakerv*)
reported extensive sighting of masses of the tarry lumps
in the open sea. Other incidents have been reported by
the International Oceanographic Foundation(9). A more
quantitative and detailed assessment of the situation was
documented by Horn et alOO) after a cruise of the
research craft R.V. Atlantis. These tarry agglomerates
were present in 75% of over 700 hauls with a surface
skimming (neuston) net in the Mediterranean Sea and
eastern North Atlantic. The amount of tar in some areas
was estimated at 0.5 milliliter in volume per square
meter of sea surface. ~\
The Mechanism of Chemical Dispersion As It
Relates to The Treatment of Spilled Oil
mechanism of chemical dispersion has previously
been covered in some detail by CanevariOM^) and
Poliakoff03), among others. However, in order to consider
the pros and cons for the use of chemical dispersants, as
well as to review recent modifications in this area, a brief
outline of the mechanism will be useful.
LAS depicted in Figure la, oil spilled on the surface of
the water has a driving force to film out, expressed as a
spreading pressure, dynes/cm. A relatively pure, nonpolar
white oil exhibits a high interfacial tension with the water
phase and normally does not spread very readily; crude oils
generally establish lower interfacial tension and spread
more readily. When a surface-active agent (surfactant) is
applied to this system, as in Figure Ib, it lowers the
interfacial tension because of its amphiphatic nature, i.e.,
partly oil soluble (lipophilic) and partly water soluble
(hydrophflic). By reducing interfacial tension in this
-------
OIL SPILL DISPERSANTS 265
manner, the generation of interfacial area upon the
application of mixing energy is enhanced as depicted in
Figure Ic, since:
WK = To/w Ao/w
wherein:
W]^ is mixing energy, ergs
AO/W is interfacial area, cm^
70/w is interfacial tension, dynes/cm
A more subtle requirement of the surface-active agent
is the prevention of coalescence of the droplets once they
are formed. This is schematically shown in Figure Id. In
essence, the surfactant acts to fend and physically parry
droplet collisions. This same property also reduces the
tendency of droplets to stick to and thereby wet an
immersed solid surface.
The vital component of any oil spill dispersant is
therefore the surface-active agent. A solvent is usually
added as a diluent or vehicle for the surfactant. It also
reduces viscosity and aids in distributing the surfactant
more uniformly to the oil layer J
a) Oil Spill Spreads
Water
b) Chemical Dispersant Applied
Surface Active Agent
c) Mixing Readily Forms Droplets
Fine0il
Droplets
d) Droplet Coalescence Prevented By Dispersant
Droplets
^^ -_ - _—= VT -__- *^> — &^^ Stabilized By
^Surface Active
——— Agent
Figure 1 - Mechanism of Chemical Dispersion
What Are The Incentives For Chemically
Dispersing Oil?
_ From the foregoing brief discussion of the dispersing
mechanism, it can be appreciated that the dispersant acts
solely as an agent to enhance the formation of oil droplets.
It does not "weight" the droplets in order to sink them. It
does not solubilize the oil into the water column. It simply
promotes an oil-in-water dispersion. Therefore, in this last
resort situation, i.e., the oil spill cannot be removed from
the sea, the following benefits for chemically dispersing and
removing the oil from the surface of the water have been
established.
1. Tlie rate of biodegradation of the oil is increased. This is
accomplished by the orders of magnitude increase in
interfacial area by dispersion. The small dispersed
droplets are known to be more conducive to bacterial
action. Further, the dispersion/dilution of the spilled oil
into the water column makes it available to a much
larger population of microbial orgaru'sms. ZoBellO^), jn
a review and treatment of this subject, cites
biodegradation rates that are one or two orders of
magnitude higher for emulsified oil compared to a
surface film. Basically, the hydrocarbons will not be
attacked at all by the microorganisms unless there is
contact of the hydrocarbon molecules with the water
phase. Since most hydrocarbons are only slightly soluble
in water, the utilization of the microorganism is
dependent upon such means as dispersion.
2. Damage to marine fowl is avoided since oil is removed
from the water surface. It is apparent that bird damage
is eliminated by the formation of fine oil droplets that
are dispersed in the upper several feet of water by the
mixing process.
3. The fire hazard from the spilled oil is reduced by
dispersion of the oil several feet into the water column.
The removal of this combustible material from the
water's surface and from contact with the atmosphere
prevents possible combustion of the spilled oil. This is
perhaps the most accepted benefit accruing from the use
of dispersants. It has provided the motivation for many
past instances of dispersant applications.
4. Tlie spilled oil is prevented from wetting solid surfaces
such as beach sand, shore property, etc. The "fending"
action of a properly selected surfactant in preventing the
droplets from sticking has been cited previously. It is
important, in this regard, to emphasize "properly
selected" surfactants since this property is dependent
upon the generic type of surfactant. Therefore, this
aspect of the dispersant's behavior is not unanimously
accepted. For example, the first Report of the
President's Panel on Oil SpillsO5) states:
"The use of emulsifiers and detergents can be justified
only if they are employed well out from the littoral
zone and if local currents send emulsifier-oil mixture
further out to the open sea. The use of detergents on
beaches, littoral zones, and harbors is more dangerous
because in making oil miscible with water, the oil will
-------
266 TREATING AGENTS
spread into the sand and penetrate crevices and the
suspended emulsion will coat the body and gills of
marine animals — surfaces which untreated oil would
not "wet."
In this regard, however, the following laboratory
experiment to evaluate this aspect will be of interest.
a. 265 cc sea water, 95 cc beach sand, and 20 cc of Kuwait
Crude were placed in a graduate. This represents a
vertical cross section of marine environment after a spill.
b. The mixture was agitated to simulate turbulent
intertidal conditions.
c. The sample was settled to separate the oil-water-sand
phases.
d. After settling, the mixture was purged with clean sea
water to simulate the return to a non-contaminated
condition.
The above experiment was then repeated with the
addition of 4 cc of a chemical dispersant to the 20 cc of
Kuwait Crude in step a. The comparative results are
illustrated in Figure 2 showing the graduates after settling
(before purging). The contamination/wetting of the sand by
the untreated oil is readily apparent. The sand phase
appears slightly discolored in the dispersant-oil system due
to the presence of fine oil droplets trapped in the interstices
of the sand bed. The non-wetting character of this treated
oil is even more evident in Figure 3 which depicts the
samples after purging with clean sea water. An analysis of
the oil content of the sand bed indicated that, in the
experiment with the untreated oil, 11.2 cc oil (of the initial
20.0 cc) had plated out on the sand.
Samples Shown After Settling
Fine Oil Droplets
Trapped In Sand
Cru> Oil
+
Sea Water
+
Sand
Crude Oil & Chemical
Dispersant
+
Sea Water
Sand
Figure 2 - Comparison of Wetting Effect of Crude Oil with and
without Chemical Dispersant
5. Tire formation of tar-like residue from an oil spill is
prevented. These floating agglomerates, as discussed
previously, range up to 10 cm in diameter. Although the
origin of these floating tar balls has been a matter of
extensive speculation recently, their formation can be
postulated as starting from a larger intact mass of spilled
oil and weathering to a residue of only 10 to 15 percent
of the original volume. It is reasonable to assume,
however, that if the oil had been chemically dispersed,
in a stable manner, into droplets less than 1 mm in
diameter, the formation of these large agglomerated
residues would be prevented.
As an oil mass weathers and becomes more viscous, its
tendency to remain intact, rather than become
segmented by the action of the sea, increases. Probably
the formation of highly viscous, semi-solid water-in-oil
emulsions - now familiarly termed "chocolate mousse"
- also aids in keeping the oil as an intact mass and
ultimately forming said agglomerates. Here again, the
use of suitable surfactants in treating (dispersing) an oil
spill has been shown by Hellmann etal.,16 Federal
Institute for Hydrological Research of West Germany, to
prevent the formation of these undesirable, gelatinous
water-in-oil emulsions. Dr. Hellmann's work is
noteworthy in that he applied basic principles of surface
behavior to the overall problem of oil spill control and
to the evaluation of various surfactants for this purpose.
Samples-Shown After Purging
Oil Contamination
Persists After
Purging
Note Clean Sand
Crude Oil
Crude Oil 8. Chemical
Dispersant
Figure 3 - Comparison of Wetting Effect of Crude Oil with and
without Chemical Dispersant
The Negative Aspects of Chemical Dispersants
Based On A Review Of Their History Of Use
Considering the aforementioned specific beneficial
aspects of removing the oil from the water's surface by the
aid of chemical dispersants, one must now ask — what are
the negative aspects and the ecological price for this last
resort solution? There are two major concerns — the first
involving the toxicity of the chemical itself and the second
involving the toxic effects of the dispersed oil. In addition,
there is some sentiment that the approved use of chemical
dispersants could result in their over-use and in laxity
toward physical removal of oil and towards the
-------
OIL SPILL DISPERSANTS 267
development of devices for this purpose. There is also a
persistent skepticism regarding the effectiveness of
dispersants in dispersing an oil spill in the first place. A
review of these aspects based on the history of this area to
date, follows:
1. The toxicity of the chemical dispersants has been a
major concern since their use became significant. The
bases for the concern were investigations such as that of
Smith et al(17) published in 1968 after the Torrey
Canyon that revealed that the particular chemicals used
did more biological damage in some areas — particularly
the intertidal zones — than the oil itself. Dr.
Cerame-Vivas(18)) m investigating dispersants used
during the grounding of the Ocean Eagle in Puerto Rico
during March, 1968, recommended that their use be
discontinued because of their high level of toxicity. A
very extensive literature search conducted by
Battelle-Northwest09) in November, 1967, cited that the
biological effects of all detergents (dispersants) are
similar and there was general agreement that levels of 5-
to 10 ppm will cause death.
In 1967-68, the period covered during the above
publications, the chemical formulations available to
disperse spilled oil were mainly derived from degreasers
and cleaning agents — in fact, the terms "detergent" and
"toxic detergents" were used quite commonly. To
permit these agents to cut through and dissolve tar-like
residues and clean similar contaminants from surfaces,
an aromatic solvent, such as heavy aromatic naphtha,
was generally employed. The short term acute toxicity
of aromatic solvents to marine life is well-known.
Blumer(20) points out that low boiling aromatics are
toxic to man as well as all other organisms, and that it
was the great tragedy of the Torrey Canyon that the
detergents used were dissolved in low boiling aromatics.
The toxicity of these aromatic solvent constituents were
extensively studied by the Marine Biological Laboratory
of the UJC. (see Ref 17), and their acute toxicity was
evident, e.g., 5 ppm of kex (kerosene extract) solvent
killed 50% of the Elminius nauplius larvae in 21
minutes. Their analyses of the more common detergents
(dispersants) used during the Torrey Canyon indicated
that they contained some portion of aromatics.
In addition to these aromatic solvents, the surfactants
were typically selected from the class of compounds
formed by the reaction of hydroxy-containing
compounds (e.g., phenol or alcohol) with ethylene
oxide.
A typical surfactant might therefore be ethoxylated
nonyl phenol. The number of ethylene oxide groups
added to the nonyl-^henol hydrophobe may be
controlled to any desired extent to adjust tfie degree of
water solubility of the material. These types of
surfactants, although effective emulsifiers, were quite
detrimental to marine life. In fresh water experiments,
Marchetti(21) in 1965 indicated that a
nonylphenol-ethylene oxide condensate was toxic at
concentrations below 10 ppm.
It can thus be appreciated that either the solvent or the
surface-active agent of a dispersant formulation can be
toxic. In the case of the Torrey Canyon era, both the
aromatic solvents and the type of surface-active agent
used in the chemical formulations possessed high light
toxicity.
However, during the past three years there has been
research directed toward producing dispersant
formulations that would have little effect on marine life.
For example, water is now used as the solvent in
products where it is compatible with the particular
formulation. High boiling saturated hydrocarbons which
are similar to the types of hydrocarbons that occur
naturally in the marine environment, and have a low
order of toxicity, are now also employed as solvents in
some of the more recent dispersant recipes.
The above modification of the solvent, and the selection
of surface-active agents from generic types that are not
considered to be chemically toxic, have resulted in the
development of dispersant products that exhibit greatly
reduced toxicity. This can be illustrated by the
investigation of J. E. PortmannC^), Fisheries
Laboratory, Burnham-on-Crouch, Essex. Table 1
illustrates this point by citing selected toxicity results to
illustrate the degree of change of the toxic level. For
example, three dispersant products used during the
Torrey Canyon spill and identified as Torrey Canyon
Dispersants A, B, C, have 48 hr LCso values of 8.8, 5.8
and 6.6 ppm, respectively. These concentrations
represent the amount of the specific agent to kill 50%
of the test species (Crangon crangon) in 48 hours. The
toxicity of a typical Torrey Canyon surfactant,
ethoxylated nonyl phenol, is shown at 89.5 ppm. By
comparison, the toxicity levels of three dispersant
products developed since the Torrey Canyon, identified
as D, E, F, are 7,500-10,000; 3,300-10,000; and
>3,300 ppm, respectively. These concentrations are
orders of magnitude greater than the level applied by
conventional application in the field. Also in this regard,
the statement that a "completely new family of
dispersants has now been developed" was made by
Beynon in a presentation to the Workshop on Oil Spill
Cleanup in the UJC. during October 1970(23)
Other agencies have confirmed this finding. Table 2
illustrates results of a recent study by the Fisheries
Research Board of Canada entitled, "Toxicity Tests with
Oil Dispersants in Connection with Oil Spill at
Chedabucto Bay, N.S."(24) Again, the large difference
in toxicity due to the surfactant-solvent recipe can be
noted in the summary of results (Table 2). These values
represent 4 day LCso values in fresh water to Salmon
(Salmo salar L) and vary from 'Toxic" (1-100 ppm) to
"Practically non-toxic" (> 10,000 ppm). These do not
represent solely isolated data points based on limited
testing to highly resistant species. Over 25 research
institutions are known to have conducted studies on
these lower toxicity chemicals. Testing by Dr. Molly
Spooner(25,26)j among others, has encompassed
juvenile species, planktonic life and other very sensitive
-------
268 TREATING AGENTS
Table 1: Some Representative Toxicity Results Illustrate Development of Low Toxicity Products
CHEMICAL TOXICITY DATA
[48 HR. LC50, PPM,
BROWN SHRIMP
(CRANGON CRANGON)]
NONYL PHENOL - ETHYLENE OXIDE 89.5
TORREY CANYON DISPERSANT 'A' 8.8
'B' 5.8
'C' 6.6
POST TORREY CANYON DISPERSANT D 7,500 - 10,000
E 3,300 - 10,000
F 3300
Abstracted from "Toxicity of 120 Substances to Marine Organisms", J.E. Portmann (22).
Table 2: Summary of Toxicity Tests With 10 Oil Dispersants
CATEGORY TOXICITY DATA NUMBER OF
[4 DAY LCso, PPM, DISPERSANTS
SALMON
(SALMO SALARL)]
PRACTICALLY NON-TOXIC 10,000 1
SLIGHTLY TOXIC 1,000-10,000 0
MODERATELY TOXIC 100-1,000 1
TOXIC " 1-100
Abstracted from Fisheries Research Board of Canada, Tech. Report 201 (24).
Table 3: Toxicity Levels of Some Dispersants with and Without Oil
TOXICITY DATA
[96 HR TLm, PPM,
DISPERSANT FATHEAD MINNOW (PIMEPHALES PROMELAS)]
PRODUCT A 56
" +OIL 14.0
PRODUCT B 14 0
" +OIL 27.0
PRODUCT C 25 0
" +OIL 42.0
PRODUCT D 32 0
" +OIL 44.0
PRODUCT E 56.0
" +OIL 75.0
PRODUCT F 3200+
" + OIL 1800+
NOTE:
DISPERSANT
Abstracted from "Biological Evaluation of Six Chemicals Used to Disperse Oil Spills", State of Michigan (29).
-------
OIL SPILL DISPERSANTS
269
forms of marine life. Studies such as those by Boyle(27)
and Stander(28) have actually surveyed the lexicological
effects at sea after application of these new chemical
dispersants to actual oil spills.
Clearly then, the concern and conclusion that all
chemical dispersants are in themselves inherently toxic is
incorrect. Some of the most effective
emulsifiers/dispersants available are those derived from and
found in the natural environment.
2. The toxicity of the dispersed oil itself is a more valid
concern. The "ecological price" for the cited benefits of
dispersing oil is the introduction of dispersed oil
droplets several feet or more into the water column. The
oil, in this physical form, is made available to other
types of marine life in addition to the
hydrocarbon-oxidizing bacteria. Necton and other filter
feeders may now come into contact with dispersed oil
droplets that they might have otherwise escaped as an
oil film on the surface of the water.
There are published data on the acute toxicity levels of
dispersed oil such as that from the State of Michigan(29)
presented as Tabl e 3. This does indicate an approximate
tolerance level of a thousand ppm or more for dispersed
oil. It can also be noted that the toxicity of the chemical
is reflected in the toxicity levels for the dispersed oil.
The basis for the often-heard statement, "the chemicals
are more toxic than the oil", can be well appreciated by
areview of these data.In considering a toxic level of 1000
ppm or so for dispersed oil, however, it should be noted
that 1) it is unlikely that fish would remain in this
inhospitable environment for 96 hours and 2) the
dispersed oil has a driving force to dilute itself.
Probably of greater concern than the above acute effects
is the possibility that the finely dispersed oil droplets
represent a more subtle contaminant and may cause
long-range effects. No such effects have been noted as an
aftermath of major spills such as the Torrey Canyon and
Santa Barbara. It should also be noted that crude ofl is a
natural rather than man-synthesized material. Wheeler
North(3°) reported after extensive research into several
spill incidents, "Unlike many of the products man
liberates into the environment, crude oil is a naturally
occurring substance. From time to time it appears on
the.earth's crust by natural processes of exudation."
However, there is a need to obtain a better assessment of
what long-range effects on marine life might exist. The
short-term toxic effects are apparent in terms of
mortality at various concentrations, tainting, etc.
Possible long-range effects, such as change in behavioral
patterns and accumulation of trace amounts of
persistent hydrocarbons, are both more nebulous and
less known. Concerning the current status of this area,
there is an extensive research program now underway at
the Battelle-Northwest Laboratories to determine these
long range effects of spilled oil - both in the untreated
and chemically dispersed state - on the marine
environment.
A variety of hydrocarbons, e.g., Kuwait Crude, So.
Louisiana Crude, No. 2 Fuel Oil and No. 6 Fuel Oil will
be tested and the test species will include all valued
organisms in the area. The ultimate fate of the ofl in the
marine environment, as well as its persistence in marine
life, will be studied.
The Effectiveness of Dispersants And The
Efficiency - Toxicity Relationship
It cannot be conclusively shown that the post Torrey
Canyon era has produced more effective, as well as less
toxic dispersants since a single reproducible and
representative laboratory test procedure for dispersant
effectiveness is still not universally accepted. Such a
comparative test method would be most useful. A Battelle
Northwest study(31) actually lists 36 tests for this purpose.
However, there is no theoretical basis for any relationship
between the toxicity of the particular surfactant and its
effectiveness as an emulsifier.
In considering the utility of these "post Torrey
Canyon" products, it may be more constructive to review
some of the field applications of the past 1-2 years. One of
the most controlled large scale tests was conducted by the
West German Government in the North Sea. Eleven metric
tons of crude oil was used for the controlled spill and
subsequently dispersed by 1030 liters of chemical
dispersant. The results were favorable, but more important
was the monitoring and evaluation of the dispersing
mechanism(32). By taking continuous dip samples during
and after the tests, it was determined that the actual
dispersion achieved consisted of ofl droplets of a few
millimeters in diameter.
The fact that droplets of this size can be maintained in
suspension in the sea is most relevant. In most proposed
criteria for dispersant application, there is consideration
for an adjustment of toxicity levels based on effectiveness
tests. In essence, a dispersant with a relative efficiency of
50% is supposed to require twice the amount to achieve the
degree of dispersion of an agent with a relative efficiency of
100%. Therefore, for two products of similar chemical
toxicity, the more "efficient" dispersant is currently
considered to be overall less toxic because of the amount
required. However, a subtle complicating factor is droplet
size. Since the basis for the efficiency rating of the chemical
is the stability of the ofl-in-water dispersion, the finer the
oil droplet, the more stable the dispersion. It has been
found during the past year, however, that finer droplets
have greater immediate acute toxicity to marine life,
particularly in the 10 micron range. Hence, the "ideal"
dispersant would seem to be one that would generate the
largest sized droplet in the field consistent with removing
the ofl from the water's surface, preventing droplet
coalescence and enhancing biodegradation.
There have been other published but more subjective
accounts of field applications that are relevant, such as that
in Tarut Bay, Saudi Arabia(33). This provides a good
example of specific areas where it was felt advisable to use
chemical dispersants and others where it was deemed
inadvisable.
-------
270 TREATING AGENTS
CONCLUSIONS
In summary, the role of chemical dispersants in the
handling of spills is unsettled and not universally agreed
upon. The obvious short-range benefits from the use of the
"post Torrey Canyon" era dispersants can now be
appreciated from the review of developments in the field
during the past two years. The ultimate use that dispersants
might find is predicated apparently on the determination of
the more nebulous long-range effects of the dispersed oil
droplets in the water column. To date, information on the
effects of both oil and dispersants has been mainly derived
from short term laboratory experiments. Data on the
long-range effects are needed to fill this gap in the scientific
knowledge on this subject. Therefore, the final resolution
of the limits of dispersant application will be based on an
objective evaluation of data from ongoing biological
studies, such as the Battelle-Northwest program and
well-monitored field applications.
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State of Michigan (1969).
30. Mitchell, Charles T., Anderson, Einar K., Jones,
Lawrence G., North, Wheeler J.: "What Ofl Does to
Ecology." Journal WPCE, Vol. 42, No. 5, Part 1, May
1970, pg. 812-818.
31. Battelle Northwest Laboratories, "Oil Spill Treating
Agents - Test Procedures", Final Report API Project
03-7, May 1,1970.
32. Hellmann, H., "Combatting Ofl with Corexit 7664, A
Large-Scale Test in the North Sea", Hansa-706 No. 16
1368-8,1969.
33. Spooner, M., "Ofl Spill in Tarut Bay, Saudi Arabia",
Marine Pollution Bulletin, November, 1970.
-------
DISPERSANT USE vs WATER QUALITY
Richard T. Dewling, J. Stephen Dorrler and
George D. Pence, Jr.
Edison Water Quality Laboratory
Environmental Protection Agency
ABSTRACT
As environmentalists, we must constantly be aware of,
and recognize the potential pollution problems that might
result from an oil spill cleanup approach or system. Based
on biodegradability and ultimate oxygen demand data
developed by the Edison Water Quality Laboratory as well
as others, it would appear that more than knowledge of
toxicity and emulsion efficiency should guide our decisions
regarding the use of chemical dispersants for oil spill
cleanup.
DISPERSANTT USE vs WATER QUALITY
The massive applications of highly toxic "detergents"
during the Torrey Canyon incident unquestionably initiated
and provoked the cloud of controversy which exists today
concerning the use of these products. Statements made at
the time of this spill, which indicated that the detergents
caused more damage^ * than the oil alone, naturally caused
the scientific community to focus its attention on the
toxicity of these chemicals to marine life. Was this
attention properly directed, or should it have been focused
on such factors as (a) the methods of application ;<2) (b) the
synergistic or antagonistic effect caused by mixing oil and
dispersants;(3)<4>(5X6) or more importantly (c) the toxici-
ty of emulsified oil itself to various forms of marine
It is not our intention to restate the technical literature
and discuss these points, or take issue with the recent
documented studies*14**15) dealing with the biological
effects associated with oil pollution. Rather, it is our
objective to bring to light yet another problem-dispersant
biodegradability— with which we must concern ourselves
when a decision is made regarding the use of dispersants for
ofl spill cleanup. From the standpoint of water quality,
there must be concern for the rate of degradation and the
ultimate oxygen demand of the dispersant and/or disper-
sant-oil mixture. This potential problem, which is para-
mount in inland or coastal polluted waters, must stand
alongside toxicity, since it too, can cause acute lethal
effects among many marine species.
U.S. Regulations-Controlled Chemical Application
The United States regulations regarding the use of
chemicals to treat oil spills, shown in Appendix I, is not one
of denial, but rather one of controlled application. In such
instances as the two Gulf of Mexico platform fires in 1970,
chemicals were applied* 16>(17> in order to eliminate a
hazard to human life. Similarly, the application of chemi-
cals may be warranted in order to protect segments of an
endangered species, or to prevent further environmental
damage.
Use under all three of these conditions is in accordance
with the Federal regulations, and, when applied to open
waters, or areas that have good mixing and circulation,
chances are, if the dispersants are used discretely and
correctly, minimal acute biological effects will likely occur.
However, let us turn the situation around and consider
using chemicals for handling a spill in an enclosed body of
water, with limited circulation, and which is moderately
polluted—50 to 75 percent dissolved oxygen saturation.
Assuming that the toxicity of the dispersant being sched-
uled for use is relatively low (TLso> 10,000 mg/1), our
environmental concern must now shift to a new area—the
potential problem of adversely affecting the oxygen re-
sources of the waterway being treated.
Dispersant Biodegradability
The problem of biodegradability and the ultimate
oxygen demand of dispersants has received little attention,
except perhaps by EPA when it established the three level
271
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272 TREATING AGENTS
control limiting the amount of dispersants which could be
applied during an oil spill incident. When applied in
quantities, chemicals themselves can be a significant pol-
lutant, and at times, depending upon the existing water
quality conditions, can lower the dissolved oxygen level to
such a point that damage to the biological community will
occur, and potentially cause more lasting influence in the
environment than toxicity.
Data developed by this laboratory, and confirmed by
others/18^ suggest that the BODs (five day biochemical
oxygen demand) of dispersants can run as high as 880,000
mg/1. Additional data on the long term oxygen demand of
various dispersants, which are shown in Tables I & II, sug-
gest that levels exceeding 1,000,000 parts per million are
attainable .(19)
TABLE 1: Edison Water Quality Laboratory Dispersant
(Amino-amido complex with water diluent)
Ultimate Oxygen Demand (UOD)
Time Oxygen Utilization (mg/1 )
(Days) *Atlantic Ocean Dilution H2& "Raritan Bay Dilution H20
1
3
4
S
6
7
8
11
12
13
15
19
20
21
22
24
25
29
31
33
99,600
106,900
111,800
128,900
128,400
165,100
255,000
279,300
284,200
318,700
330,300
383,800
410,500
429,900
444,500
481,000
561,200
595,200
614,700
295,200
350,400
410,400
460,800
504,000
578,400
710,400
724,800
736,800
746,400
792,000
799,200
805,200
817,200
822,000
853,300
894,600
906,700
916,300
* Dilution waters unseeded
It is noteworthy to point out in Table I the difference in
ultimate demands for the two dilution waters used. Raritan
Bay is somewhat polluted in comparison to Atlantic Ocean
water; therefore, it is felt that it has the necessary seed
organisms and nutrients to develop this higher demand.
Additional data are naturally needed to confirm this
theory.
UOD Significance
What is the significance of such data as it relates to an
actual oil spill incident? As an illustration, let us assume
that 75,000 barrels of oil were spilled into the Delaware
River at the mouth of the Schuylkill River, and it was
suggested that dispersant chemicals be used to clean up the
complete spill.
Water quality data in this waterway have been well
established by previous EPA investigations, and mathemat-
ical models have been developed for dissolved oxygen
loadings^20' thus the reason for selecting the Delaware
River for this example. Figure 1 illustrates River "Sections"
for the mathematical model and shows where the "spill"
occurred.
As illustrated in Figure 2, which also indicates the as-
sumptions for the estuary and spill, the oxygen deficit at
"day one," after chemicals have been applied, is 1.5 mg/1 at
Section 15, located downstream from Philadelphia. As-
suming 100 percent dissolved oxygen saturation in the
River, which is approximately 9.2 mg/1 at 20°C, this deficit
will probably not cause adverse water quality conditions.
On the third day following the spill and application of
chemicals, an oxygen deficit of 3.4 mg/1 is produced. Again,
if 100 percent saturation prevails, there will probably be no
immediate acute biological stress or response; however, a
serious problem, with adverse environmental consequences,
will likely occur if the oxygen saturation of the river is 50
percent (4.6 mg/1) or lower, a condition which we know
normally exists in this and other polluted estuaries and
rivers during many months of the year.
CONCLUSIONS
As environmentalists, we must constantly be aware of,
and recognize the potential pollution problems that might
result from an oil spill cleanup approach or system. Based
on the data presented, it would appear that more than
TABLE 2: Twenty-Day Biochemical Oxygen Demand< * 9>
Dispersant
A-(Petroleum solvent,
alkylaryl benzene,
non ionic)
A
A
A
A
B -(A Ikanolamides,
no diluent)
B
B
B
B
C -(Water-alcohol
diluent, non ionic)
C
C
C
C
D-(Petroleum based,
non ionic)
D
D
D
D
Oil
South Louisiana Crude Oil
Bachaquero Crude Oil
No. 2 Fuel Oil
No. 6 Fuel Oil
South Louisiana Crude Oil
Bachaquero Crude Oil
No. 2 Fuel Oil
No. 6 Fuel Oil
South Louisiana Crude Oil
Bachaquero Crude Oil
No. 2 Fuel Oil
No. 6 Fuel Oil
South Louisiana Crude Oil
Bachaquero Crude Oil
No. 2 Fuel Oil
No. 6 Fuel Oil
B.O.D. (mg/1)
783,000
480,000
117,000
880,000
150,000
850,000
521,000
87,000
830,000
190,000
450,000
378,000
255,000
797,000
298,000
1,334,000
445,000
330,000
757,000
306,000
-------
DISPERSANT USE vs WATER QUALITY 273
Assunpink
Creek
"Oil Spill' of 75,000 bbls occurred at
Section 15, located south of Philadelphia
and at mouth of Schyulkill River
DIL SPILL //6i9
Timbe
Creek
Smyrna
Rivet
Figure 1: Mathematical Model River Sections-Delaware Estuary
-------
Philadelphia
10 11 12 13
RIVER MATH MODEL SECTIONS
Chester
rs
Wilmington
21 22
23 24 25 26 27 28
29
30
Based on the response of the Delaware River to
a unit impulse load, which was simulated on an
analog computer,' 21) graphs were developed for
the oxygen deficits for "days" 1,3,5,8 and 12
following a 75,000 barrel spill at "Section 15" of
the River. Other assumptions were:
T1.5Q of dispersant recommend for use was
10,000 mg/l ; oil thickness of 2mm; con-
trolling criteria for dispersant use would be
1/5 of total volume spilled; or 630,000
gallons
UOD of dispersant = 916,000 mg/l
Freshwater inflow to River = 3,000 cfs
Total mixing and diffusion throughout
depth of River 36 foot average depth
Decay coefficient 0.2/day
Reaeration coefficient 0.2/day
Dispersion coefficient 7 sq. mi./day
l-'igurc 2: Dispersant Use vs Water Quality
H
m
H
2
O
rn
Z
to
-------
DISPERSANT USE vs WATER QUALITY 275
knowledge of toxicity and emulsion efficiency should guide
our decisions regarding the use of dispersant chemicals for
treating oil spills.
Figure 3: Warburg Respirometer was Used at the Edison Water
Quality Laboratory to Determine Rate of Biodegradability and
Ultimate Oxygen Demand of Dispersants
APPENDIX I
SCHEDULE OF DISPERSANTS AND OTHER
CHEMICALS TO TREAT OIL SPILLS
(Published as Annex X to National Contingency Plan,
June 2, 1970)
2001 General
2001.1 This schedule shall apply to the navigable waters
of the United States and adjoining shorelines, and the
waters of the contiguous zone as defined in Article 24 of
the Convention on the Territorial Sea and the Contiguous
Zone.
2001.2 This schedule applies to the regulation of any
chemical as hereinafter defined that is applied to an oil
spill.
2001.3 This schedule advocates development and utili-
zation of mechanical and other control methods that will
result in removal of oil from the environment with
subsequent proper disposal.
2001.4 Relationship of the Water Quality Office, En-
vironmental Protection Agency (WQO-EPA) with other
Federal agencies and State agencies in implementing this
schedule: in those States with more stringent laws, regula-
tions or written policies for regulation of chemical use,
such state laws, regulations, or written policies shall govern.
This schedule will apply in those States that have not
adopted such laws, regulations or written policies.
2002 Definitions
Substances applied to an oil spill are defined as follows:
2002.1 Collecting agents—include chemicals or other
agents that can gell, sorb, congeal, herd, entrap, fix, or
make the oil mass more rigid or viscous in order to
facilitate surface removal of oil.
2002.2 Sinking agents—are those chemical or other
agents that can physically sink oil below the water surface.
2002.3 Dispersing agents—are those chemical agents or
compounds which emulsify, disperse or solubilize oil into
the water column or act to further the surface spreading of
oil slicks in order to facilitate dispersal of the oil into the
water column.
2003 Collecting Agents
Collecting agents are considered to be generally ac-
ceptable providing that these materials do not in themselves
or in combination with the oil increase the pollution
hazard.
2004 Sinking Agents
Sinking agents may be used only in marine waters
exceeding 100 meters in depth where currents are not
predominantly on-shore, and only if other control methods
are judged by WQO-EPA to be inadequate or not feasible.
2005 Authorities Controlling Use of Dispersants
2005.1' Regional response team activated; Dispersants
may be used in any place, at any time, and in quantities
designated by the On-Scene Commander, when their use
will;
2005.1-1 in the judgment of the On-Scene Com-
mander, prevent or substantially reduce hazard to
human life or limb or substantial hazard of fire to
property;
2005.1-2 in the judgment of WQO-EPA, in consulta-
tion with appropriate State agencies, prevent or
reduce substantial hazard to a major segment of the
population(s) of vulnerable species of waterfowl; and
2005.1-3 in the judgment of WQO-EPA, in consulta-
tion with appropriate State agencies, result in the
least overall environmental damage, or interference
with designated uses.
2005.2 Regional response team not activated; Provi-
sions of Section 2005.1-1 shall apply. The use of disper-
sants in any other situation shall be subject to this schedule
except in States where State laws, regulations, or written
policies that govern the prohibition, use, quantity, or type
of dispersant are in effect. In such States, the State laws,
regulations or written policies shall be followed during the
cleanup operation.
-------
276 TREATING AGENTS
2006 Interim Restrictions on Use of Dispersants
for Pollution Control Purposes
Except as noted in 2005.1, dispersants shall not be used;
2006.1 On any distillate fuel oil;
2006.2 on any spill of oil less than 200 barrels in
quantity;
2006.3 on any shoreline;
2006.4 in any waters less than 100 feet deep;
2006.5 in any waters containing major populations, or
breeding or passage areas for species of fish or marine life
which may be damaged or rendered commercially less
marketable by exposure to dispersant or dispersed oil;
2006.6 in any waters where winds and/or currents are
of such velocity and direction that dispersed oil mixtures
would likely, in the judgment of WQO-EPA, be carried to
shore areas within 24 hours; or
2006.7 in any waters where such use may affect surface
water supplies.
2007 Dispersant Use
Dispersants may be used in accordance with this
schedule if other control methods are judged to be
inadequate or infeasible, and if:
2007.1 Information has been provided to WQO-EPA, in
sufficient time prior to its use for review by WQO-EPA, on
its toxicity, effectiveness and oxygen demand determined
by the standard procedures published by WQO-EPA. (Prior
to publication by WQO-EPA of standard procedures, no
dispersant shall be applied, except as noted in Section
2005.1-1 in quantities exceeding 5 ppm in the upper 3 feet
of the water column during any 24-hour period. This
amount is equivalent to 5 gallons per acre per 24 hours.);
and
2007.2 applied during any 24-hour period in quantities
not exceeding the 96 hour TL5Q of the most sensitive
species tested as calculated in the top foot of the water
column. The maximum volume of chemical permitted, in
gallons per acre per 24 hours, shall be calculated by
multiplying the 96 hour TL5Q value of the most sensitive
species tested, in ppm, by 0.33; except that in no case, ex-
cept as noted in Section 2005.1-1, will the daily application
rate of chemical exceed 540 gallons per acre or one-fifth of
the total volume spilled, whichever quantity is smaller.
2007.3 Dispersant containers are labeled with the fol-
lowing information:
2007.3-1 Name, brand or trademark, if any, under
which the chemical is sold;
2007.3-2 name and address of the manufacturer,
importer or vendor;
2007.3-3 flash point;
2007.3-4 freezing or pour point;
2007.3-5 viscosity;
2007.3-6 recommend application procedure(s), con-
centration^), and conditions for use as regards water
salinity, water temperature, and types and ages of
oils; and
2007.3-7 date of production and shelf life.
2007.4 Information to be supplied to WQO-EPA on the:
2007.4-1 Chemical name and percentage of each
component;
2007.4-2 concentrations of potentially hazardous
trace materials, including, but not necessarily being
limited to lead, chromium, zinc, arsenic, mercury,
nickel, copper or chlorinated hydrocarbons;
2007.4-3 description of analytical methods used in
determining chemical characteristics outlined in
2007.4-1,2 above;
2007.44 methods for analyzing the chemical in fresh
and salt water are provided to WQO-EPA, or reasons
why such analytical methods cannot be provided;
2007.4-5 for purposes of research and development,
WQO-EPA may authorize use of dispersants in
specified amounts and locations under controlled
conditions irrespective of the provisions of this
schedule.
REFERENCES
1. Smith, J. E., (edit) Torrey Canyon Pollution and
Marine Life, Cambridge University Press, N.Y.C., 1968
2. Anon "The Torrey Canyon", Report of the Commit-
tee of Scientists on the Scientific and Technological
Aspects of the Torrey Canyon Disaster. HA!. Stat. Off.,
London, 1967
3. Griffith, D.G., Toxicity of Crude Oil and Detergents
to Two Species of Edible Molluscs Under Artificial Tidal
Conditions, FAO Technical Conference on Marine Pollution
and Its Effect on Living Resources and Fishing, December
1970
4. Tarzwell, C., Proceedings: Industry Government
Seminar, Oil Spill Treating Agents, April 1970
5. Mills, Jr., E.R., The Acute Toxicity of Various Crude
Oils and Oil Spill Removers on Two Genera of Marine
Shrimp, Louisiana State University, May 1970
6. Cowell, E.B., et al., Biological Effects of Oil Pollu-
tion and Oil Cleaning Materials on Littoral Communities,
Including Salt Marshes, FAO Technical Conference on
Marine Pollution and Its Effect on Living Resources and
Fishing, December 1970
7. Blumer, M., et al., Hydrocarbon Pollution of Edible
Shellfish by an Oil Spill, Woods Hole Oceanographic
Institution, Ref. No. 70-1
8. Gutsell, J.S. (1921) Danger to Fisheries from Oil and
Tar Pollution of Waters, App. II, Rept. to U.S. Commis-
sioner of Fisheries, Bur. Fish. Doc. 910
9. Gage, S. DeM. (1924) The Control of Oil Pollution
in Rhode Island, Papers Boston Soc. Civil Eng. 11 (6) 237
-------
DISPERSANT USE vs WATER QUALITY 277
10. Gowanlock, J.N. (1935) Pollution by OH in Relation
to Oysters, Trans Amer Fish Soc. p. 293
11. Anon (1955) Oil Pollution Studied by Service's
Seattle Biological Laboratory, Commercial Fisheries Review
17(3)35
12. Tagatz, M.E. (1961) Reduced Oxygen Tolerance and
Toxicity of Petroleum Products to Juvenile American Shad,
Chesapeake Science, 2 (1-2) 65
13.McKee, J.E., Wolf, N.W. (1963) Water Quality
Criteria, Publ. 3A, Resources Agency of California, State
Water Quality Control Board, 2d Edit., p. 229
14. Straughan, D., Biological and Oceanographical Sur-
vey of the Santa Barbara Channel Oil Spill 1969-1970,
Volume I, Biology & Bacteriology, Allan Hancock Founda-
tion, University of S.C., 1971
15. Blumer, M., et al., The West Falmouth Oil Spill,
Woods Hole Oceanographic Institution, Ref. No. 70-44
16. Biglane, K., EPA, WQO, Office of Oil & Hazardous
Materials. Personal Communication, 1971
17. Ocean Industry, Feb., March 1971
18. Anon. A Biological Evaluation of Six Chemicals used
to Disperse Oil Spills, Department of Natural Resources,
State of Michigan, 1969
19. Anon. Pacific Engineering Laboratory, Preliminary
Report on Testing Oil Dispersant Toxicity & Emulsion
Efficiency, EPA, WQO, Contract No. 14-12-879, March
1971
20. Delaware Estuary Comprehensive Study-Preliminary
Report and Findings F.W.P.C.A., July 1966
21. Pence, G., Analog Simulation Model, Delaware Estu-
ary Comprehensive Study, Unpublished.
-------
DEVELOPMENT OF TOXICITY TEST
PROCEDURES FOR MARINE
PHYTOPLANKTON
J.A. Strand, W.L. Templeton,
J.A. Lichatowich, and C. W. Apts,
Aquatic Ecology Section, Ecosystems Department,
Pacific Northwest Laboratory,
Battelle Memorial Institute
ABSTRACT
Recommended bioassay procedures are presented that
can be routinely applied to evaluate the relative toxicity of
oil, chemical dispersants, and oil-dispersant mixtures to 1)
naturally occurring populations of phytoplankton, and 2)
representative marine phytoplankters grown in pure
culture. The methods presented, in general, represent 1)
application of techniques routinely employed in the
measurement of marine primary productivity, and 2)
application of the Inhibitory Toxicity Test, a tentative
method devised by the American Society for Testing and
Materials to evaluate acute toxicity of industrial wastes to
diatoms.
INTRODUCTION
There is increasing evidence for detrimental effects to
fish (3, 15), Crustacea (2, 4, 21), molluscs (2), and other
aquatic organisms (1, 2, 13, 31) from the release of crude
or refined oils and subsequent application of oil treating
agents. However, few researchers have examined the
influence of these materials on phytoplankton which
comprise basic and essential elements of almost all aquatic
food webs.
The bioassay method is generally accepted as the
standard procedure to assess the acute effects of a toxicant
on a selected organism. The bioassay, an outgrowth of
chemical assay, has traditionally employed lethality as the
measurement of effect. However, lethality or death cannot
*The studies presented in this paper were prepared under
contract for the American Petroleum Institute, Committee for Oil
and Water Conservation.
always be determined; and for algal cells, lethality is not
considered a reliable end point (29).
With this in mind, we have searched for alternative
methods for evaluating the effects of oil and dispersants on
marine phytoplankton. In this report, bioassay procedures
are presented that can be routinely applied to evaluate the
relative toxicity of oil, chemical dispersants, and
oil-dispersant mixtures to 1) naturally occurring
populations of phytoplankton, or 2) representative marine
phytoplankters grown in pure culture.
General Procedures
The methods presented in this report represent 1)
application of techniques routinely employed in the
measurement of marine primary productivity, and 2)
application of the Inhibitory Toxicity Test (11), a tentative
method devised by the American Society for Testing and
Materials to evaluate acute toxicity of industrial wastes to
diatoms.
Oil-Dispersant Mixtures
Emulsions of crude oil and the chemical dispersant
were tested in a ratio of 10 parts oil to 1 part chemical
dispersant by volume. Concentration of oil and dispersant
are expressed in parts per million (ppm) of the total
product (oil and dispersant) in each test solution. Test
solutions were prepared by first adding oil, then dispersant
and finally diluent water, all at desired amounts.
Continuous mixing using a magnetic stirrer was found
to produce excellent dispersions. Oil and dispersant
emulsions prepared in this way immediately disperse into
small globules and are distributed throughout the entire test
'solution. Emulsions not continuously mixed during
279
-------
280 TREATING AGENTS
preparation tended to coalesce into a sb'ck on the water
surface with only a fraction of the total emulsion being
dispersed throughout the test solution.
Application of Marine Productivity Measurements
Isotopic Carbon Method
Doty and Oguri (6) and Jitts (9) have published
standard methods for measuring photosynthetic rates using
the Cl4 technique. Strickland (26) and Ryther (18)
compared the Cl4 and oxygen methods for measuring
photosynthesis of marine algae and found the former
50-100 times more sensitive. The Cl4 technique has been
subjected to much refinement since first introduced and
employed by Steemann-Mielsen (22, 24). The theoretical
basis and underlying assumption have been reported by Van
Norman and Brown (29), Goldman and Mason (7), Rodhe
(17), Steemann-Nielson and Hanson (23), McAllister (12),
and Ryther (19). Most recently, the application of this
technique for assessment of the effects of organomercurial
fungicides on marine diatoms was reported by Harriss et al.
(8).
In the present studies, the Cl4 technique was used in
two experimental designs. Basically these tests were:
1. Field experiments using natural surface sea water and
natural mixed phytoplankton communities.
2. Laboratory experiments using purified marine flagellate
cultures.
In Situ Bioassay with Natural Seed
Methods
A small platform anchored in a shallow estuary was
used as a permanent sampling station. Water samples were
taken at a depth of .5 meters with a Kremmer water
sampler and transferred to 125 ml glass bottles. Some of
the bottles (dark bottles) were coated with black
rubberized material to eliminate light. Three mis of water
were withdrawn from each bottle and 1 ml of sea
water-dispersant mixture was added to produce the
required concentration. One ml of a 10 microcurie solution
of CJ4 labeled sodium carbonate (NaHCOs) was added to
each bottle. Three ml were withdrawn and only two
replaced to prevent escape of Cl4 labeled water as the
stopper was inserted. Bottles thus prepared were incubated
for 24 hours suspended from the platform at a depth of .5
meters.
The contents of each bottle were then passed under
vacuum through a .45 micron Millipore Filter. The filter
was placed in a scintillation counting vial containing 17 ml
scintillant cocktail. The scintillant cocktail was prepared by
dissolving 5 g PPO and 0.5 g POPOP in 1000 ml toluene,
and then adding 30.6 ml Beckman Biosolve BBS-3. The
radioactivity was determined as counts per minute (CPM).
Quench was determined by adding a known amount of Cl4
to the vial and recounting. This allowed us to back calculate
and correct the initial sample counts for quench due to
chemical interference or self absorbtion by the algal cells.
Once the counts per minute (CPM) for each sample were
corrected, the net CPM was derived by subtracting the dark
bottle CPM from light bottle CPM. Photosynthesis as
^ was then calculated by the equation:
Net CPM
1
total added CPM Hours of incubation
x C02 (mg per liter sea water)
x 12x 1000 = mgC/n/m3 (5)
44
A 50 per cent reduction in photosynthetic rate as
measured by uptake of carbon-14 relative to uptake by
controls may be used as a standard measurement of
toxicity.
Results
Figures 1 and 2 demonstrate the effects of a selected
oil and dispersant emulsion on primary production of
planktonic algae obtained from the natural environment.
The curves, from two independent tests, represent exposure
times of 8 and 15 hours respectively.
The slight increase in mean productivity rate at the 1
ppm level as indicated in both Figures 1 and 2 is
reproducible and significant at the 0.05 probability level as
determined by the least significant difference test of
Senadacor (20). This perhaps indicates an initial
stimulatory effect due to substances in the oil and
dispersant mixture. This effect is less evident at 15 hours
exposure. There is no significant difference between
controls, 0 ppm, and the 10 ppm treatments.
Photosynthesis or productivity is significantly reduced at
50,100 and 1000 ppm.
10 50 100 1.000
Holl Che* 622-KuMalt Crude Evulsion (ppm)
Figure 1: The relationship between oil-dispersant emulsions and
Primary Production of Planktonic Algae from Seqium Bay. Samples
taken eight hours after contaminating water with the emulsion. The
range of values at each concentration represent 4 replicate
determinations.
-------
TOXICITY TEST PROCEDURES . . .
281
Successive daily determinations covering a period of
nearly 3 months disclose significant variation in the baseline
rate of primary production; undoubtedly attributed to
changes in environmental parameters of light, temperature
or changes in the diversity and density of the plank. M
community.
or different days more comparable, tests should be
conducted at the same time each day.
Water analysis should include pH, salinity, alkalinity,
DO and temperature, salinity pH, and alkalinity are needed
to estimate total free C02- CO2 is used to calculate the
ratio of C12 an
10 50 100
Dlspersant Concentration In pp«
Figure 2: The relationship between Oil-Dispersant Emulsions and
Primary Production of planktonic algae from Seqium Bay. Samples
taken fifteen hours after contaminating water with the emulsion.
The range of values at each concentration represent 4 replicate
determinations.
Discussion
The in situ algal bioassay utilizing the C^4 technique
represents a rapid sensitive way to assess the effects of
discharged oil and chemical treatment on phytoplankton. It
is especially suitable for assessing the effect of oil in the
open sea. Photosynthetic rates of samples collected just
below the surface of an oil contaminated area can be
compared to photosynthetic rates of samples from adjacent
uncontaminated water. The samples may be incubated in
the sea or more conveniently in an ambient temperature
water bath on shipboard.
Patchy distribution of algal cells in the sea necessitates
the use of several replicate samples. The statistical
sensitivity of the differences between control and treated
samples will increase with the number of replicates. A
minimum of four light and one dark sample is suggested.
With careful application, technical error introduced by the
operator is negligible. Coefficients of variation between 11
and 25 per cent can be expected as a result of natural
variation or systematic error.
Incubation time will vary with the estimated
productivity of the area. Eutrophic coastal regions would
need 2-6 hours incubation whereas oliegotrophic areas in
the open sea may need 6-10 hours of incubation.
Photosynthetic rates seem to vary on a daily
periodicity. In order to make data from different samples
Laboratory Bioassay with Purified Seed
Bioassay techniques similar to the in situ experiments
utilizing natural plankton populations were employed to
determine the effect of oil-dispersant emulsions on
laboratory grown phytoplankters,
Monochrysis lutheri, for use in these bioassays was
mass cultured in 2 1/2 gallon carboys placed in a constant
temperature water bath maintained at 20.0° C. Culture
medium was prepared by adding the nutrients prescribed by
Strand (25), Table I, to autoclaved sea water. Six thousand
mis of this medium in a 2 1/2 gallon carboy was seeded
with a 500 ml aliquot from a stock Monochrysis culture.
There was no need to sparge the medium as the
Monochrysis cells appeared to distribute themselves
uniformly throughout the container. Periodic cell counts
were made with a hemocytometer and as population
growth reached its peak (2 weeks), 500 mis of this
population were transferred into another six thousand mis
of fresh medium. Overhead lighting was provided by a bank
of fluorescent lamps which yielded an irradiance of 3.7 lux
at the water bath surface, and which was programmed for a
photoperiod of 1 2 hours light and 1 2 hours dark.
Table 1: Sea Water Enrichment Mixture
KN03 20.0 mg.
K/2HP04 3.5 mg.
FeCL3 0.097 mg.
MnCl2 0.0075 mg.
Glycerophosphate di-sodium pentahydrate 1.0 mg.
EDTA 1.0 mg.
B12 l-QW-
ThiaminHCl 0.2 mg.
Biotin 1-0/*g-
Tris (hydroxymethel) aminomethane 30.0 mg.
Fresh off-shore sea water 75.0ml.
Distilled water 25.0 ml.
Six, five hundred ml aliquots of a pure culture of
monochrysis a marine flagellate, were mixed with 5,500 mis
fresh culture medium in each of six 2 1/2 gallon carboys.
Samples from each 500 ml culture aliquot were counted to
ensure each carboy received an equal number of algal cells.
The carboy was sealed with a rubber stopper pierced by
three glass rods. Two glass rods extended to near the
bottom of the carboy; one for withdrawing samples; the
-------
282 TREATING AGENTS
other for introducing air from a compressor to insure
continued mixing of oil and dispersant during exposure.
The third, a shorter glass rod, maintained air equilibration.
These experiments were conducted in a constant
temperature room maintained at 20+1°C. Overhead
fluorescent lighting was provided as above.
Oil-dispersant emulsions were prepared, introduced
into the carboys with Eppindorf automatic pipettes and
allowed to mix the Monochrysis-meAium for two hours
before sampling. Five 125 ml samples were drawn (four
light bottles, one dark) from each carboy. The samples were
inoculated with 10 microcurie solution Cl4 of labeled
NaHCOs and allowed to incubate at 20+1° C for six hours.
Fifteen minutes prior to sampling, air introduced to the
carboy was shut off, allowing the dispersed oil to rise to the
surface. By drawing algal samples from below the "slick"
we obtained cells that had been exposed to oil and
dispersant, but the sample itself was relatively free of oil.
This lessened problems such as C^ adsorbed to oil
particles, oil particles pluging the Millepore filter, arid
quench due to oil in the scintillant cocktail. The incubated
samples were processed as previously described.
The photosynthetic rates expressed as mgC/hr/m^
were calculated using the same formula presented in the
previous section.
Results
By using known amounts of rapidly growing
Monochrysis we hoped to reduce variability; and by
increasing the number of replicates, obtain significant
differences in production over a narrower range of
concentrations. The least significant difference test was run
on the data presented in Figure 3. All mean production
values for algae treated with the oil-dispersant emulsion
were significantly different, at 0.5 probability level, from
the controls. There were significant differences between
mean production values for the different treatments except
between 60 and 80 ppm, and at 100 ppm.
Discussion
For routine bioassay, purified cultures of marine
phytoplankters are recommended. For prediction of
environmental effects, cultures of indigenous algal species
isolated from the region of concern are suggested. Since cell
densities and the physiological state of the culture can be
more effectively controlled, the use of cultured algae will
enable researchers to standardize the reporting of the
relative toxicity of various dispersants, oil, and
oil-dispersant emulsions. Algae should be cultured at the
temperature which the tests will be conducted. If there is to
be a temperature change, sufficient time should be allowed
for the particular species to make the physiological
adjustments. Fresh culture medium should be used for each
series of bioassays. Once the medium has been seeded with
an algae culture the bioassay should be conducted shortly
afterwards since photosynthesis decreases as the population
density increases and nutrients become limited.
5.00
1)0 60 BO 100 100
Roll Chem 622-Kuwalt Crude Esulslon In ppm
Figure 3: Relationship between oil-Dispersant Emulsions and
Primary Production of Monochrysis Lutheri at 20 C. The Range of
Values at each Concentration Represent 4 Replicate
Determinations.
Chlorophyll-a Method
As early as 1930, Kreps and Verbinskaya (28) used
chlorophyll as a measure of marine phytoplankton
productivity; and a field technique, using comparisons of
acetone extracts against aqueous standards of nickel
chromate was initiated by Harvey (28). The method of
Creitz and Richards (28) which involves filtering the plant
cells from 0.5 to 10 liters of water through a membrane
filter and adding the filter to a 90 per cent acetone-water
mixture to dissolve it and extract phytoplanktonic
pigments, has been used extensively since 1955.
Methods
Experiments designed to test the effect of dispersants
and oil-dispersant emulsions on marine phytoplankton by
determining the concentration of chlorophyll-a were
conducted in accordance with procedures outlined by
Creitz and Richards (28). Cultures of the flagellate
Monochrysis lutheri were used in this series of tests. Three
types of experiments were conducted.
1. Cultures were contaminated with a wide range of
concentrations of oil-dispersant emulsions to determine the
approximate toxicity threshold.
2. Cultures were exposed to a narrow range of
concentrations to determine if small differences in toxicity
could be determined by this method.
3. A series of tests were performed to determine if the
toxicity of a dispersant was reduced by aeration.
A basic procedure is common to all three types of tests.
250 ml Erlenmeyer flasks were filled with 200 ml fresh
-------
TOXICITY TEST PROCEDURES ... 283
culture medium as described in Table I (25). Each flask was
seeded with a 2 ml aliquot from a purified culture of
Monochrysis. The oil-dispersant emulsion prepared as
previously described, the oil-dispersant emulsion was
metered into the Erlenmeyer flask with an Eppindorf
automatic pipette. The Erlenmeyer flasks were capped with
cotton and incubated for 3-5 days at 20+1° C under 3.7 lux
of fluorescent illumination. Before filtering, a two or three
ml aliquot of a 1 M solution MgCI/j was added to each
Erlenmeyer flask; the content of each flask was then
filtered through a .45 micron Millepore filter. The Millepore
filter was then placed in a small vial with 10 ml 90%
acetone. The vial was wrapped in aluminum foil and kept in
a refrigerator at 7° C for 24 hours.
After 24 hours the vials were centrifugal and the
supernatant poured into a 10 ml cuvette having a path
length of 10 cm. The cuvettes were kept in the dark until
placed in the spectrometer.
Absorption (synonymous with extinction or optical
density) was read directly on a Bausch and Lomb
"Spectronic 20" spectrometer at 665, 645 and 630
milli-microns. The Richards and Thompson (16) formula
was used to convert absorption readings to mg/1
chlorophyll. Per cent transmission can also be used- if
converted to absorbance by the formula:
abosrbance = 109jQ
100
transmission
10 pp» 100 w>» t.OOO pp» 10.000 pp»
DlsporMnt Concentration In pp»
Figure 4: Amount of Chlorophyll-a Extracted From Cultures of
Monochrysis Exposed to Dispersant. The Range of Values at each
Concentration Represent 3 Replicate Determinations.
However, Strickland and Parsons (27) discourage this since
per cent transmission is not directly related to the
concentration of substance being measured.
The first chlorophyll experiment employed three
replicates of five concentrations of dispersant. The samples
were incubated five days.
The second experiment was similar to the first except
an oil-dispersant emulsion was used. The concentrations
ranged over a narrow interval and there were four replicates
at each concentration.
In the third experiment we initiated four separate tests.
Each consisted of five concentrations of dispersant, but in
each test the dispersant used had been aerated for a
different length of time.
Results
Figure 4 graphically presents the relationship between
the dispersant and the chlorophyll content of Monochrysis
cultures. The apparent toxic threshold is in the 10-100 ppm
range. Variability within a single concentration appears to
be negligible.
Results — Figure 4 graphically presents the relationship
between the dispersant BP 1100 and the chlorophyll
content of Monochrysis cultures. The apparent toxic
threshold is in the 10-100 ppm range. Variability within a
single concentration appears to be negligible.
The results of the second type of experiment is shown
in Figure 5. In this test we were able to differentiate
differences in chlorophyll-a concentration over a narrower
range of effluent concentrations. The effect indicated in
Figure 5 seems to compliment the effects depicted in
Figure 3 of the C14 experiments; that is, the apparent toxic
threshold being in the 10 to 100 ppm range. The two tests
were conducted using a similar concentration range of
oil-dispersant emulsion.
Data from the third experiment is presented in Table
II. Aeration decreases toxicity. The toxic threshold seems
to increase, i.e. the dispersant becomes less toxic the longer
it is aerated. Boney (1), found similar results with aerated
BP 1100 fractions using the green algae, Prasinocladus
marinus.
Discussion
The concentration of chlorophyll-a in purified
flagellate cultures is sensitive to contamination by
oil-dispersant emulsion or oil dispersants alone. The
reduction in chlorophyll-a seems to compliment reduction
in photosynthesis in rapidly growing purified flagellate
cultures.
While a reduction in chlorophyll-a may not always
represent a similar reduction in productivity, Odum, et al.
(14), it does represent a loss in the potential productivity of
the system. During periods of low temperature chlorophyll
concentration may not be the factor limiting
photosynthesis. The amount and activity rate of the cellular
enzymes may limit photosynthesis, Jorgenson,
Steemann-Nielsen; (1); however, as environmental
conditions change and chlorophyll becomes limiting, any
loss in chlorophyll will then be reflected in lowered
productivity.
This bioassay can be used to determine the relative
toxicity of various dispersants, dispersant-oil emulsions and
-------
284 TREATING AGENTS
Table 2: Concentration of Extracted Chlorophyll-a in Monochrysis Cultures Exposed
to the Dispersant BP
Treatment
Control
1 ppm
10 ppm
100 ppm
1,000 ppm
10,000 ppm
Control
1 ppm
10 ppm
100 ppm
1,000 ppm
10,000 ppm
Control
1 ppm
10 ppm
100 ppm
1,000 ppm
10,000 ppm
Control
1 ppm
10 ppm
100 ppm
1,000 ppm
10,000 ppm
1 100 Which was not Aerated or was Aerated
Aeration Time
0
0
0
0
0
0
1 hour
1 hour
1 hour
1 hour
1 hour
1 hour
4 hours
4 hours
4 hours
4 hours
4 hours
4 hours
8 hours
8 hours
8 hours
8 hours
8 hours
8 hours
for 1 , 4 or 8 hours.
Chlorophyll-a
mg/1
3.61
4.24
1.43
0.922
0.445
0.0
3.68
3.81
3.84
1.83
0.539
0.00
2.27
2.59
2.76
2.40
0.00
0.012
2.44
7.10
2.76
2.44
1.66
0.038
J 3
Holl Che* 622-Kintalt Crude EBulslons (pp«)
Figure 5: Relationships Between oil-Dispersant Emulsion and
Chlorophyll-a Concentation of Monochrysis. The Range of Values at
Each Concentration Represent 4 Replicate Determinations.
refined or unrefined oils. Minimal amounts of equipment
are needed. The prescribed measurement of toxicity may be
expressed as a Median Tolerance Limit, TLM, or the
concentration of the test material that produces a 50 per
cent reduction in extractable chlorophyll-a. Odum, et al.
(14), have evaluated the Bausch and Lomb "Spectronic 20"
and justify its use if extreme accuracy is not required. This
test then represents a sensitive way of assessing the effect of
oil dispersants and oil-dispersant emulsions on a compound
essential to phytoplankton. However, care must be
exercised in interpreting this effect in terms of primary
production.
Inhibitory Toxicity Bioassay
The preceding tests used photosynthetic rate and
chlorophyll-a concentration to assay the effects of
oil-dispersant emulsions and oil dispersants on
phytoplankton. Photosynthesis and chlorophyll-a, assuming
a relationship between chlorophyll-a and photosynthesis, to
have their fullest meaning should be looked at relative to
the size of the population, since fast growing, but small
populations, may have the same production rate, i.e. the
amount of biomass produced over a given period of time, as
a slow growing but large population. In this case cell counts
would serve as an adequate index of population size.
-------
TOXICITY TEST PROCEDURES ... 285
Methods
For a detailed account of procedures, the reader is
referred to the ASTM Manual on Industrial Water and
Industrial Waste Water, 2nd Edition (11).
Erlenmeyer flasks (250 ml) were filled with 200 mis
fresh culture medium as prepared in Table I (25). Each
flask was seeded with a 2 ml aliquot from a purified culture
of Monochrysis The oil-dispersant emulsion was prepared as
before and metered into each test flask using an Eppindorf
automatic pipette. The flasks were capped with cotton and
incubated at 20+1° C under 3.7 lux of fluorescent
illumination.
Cell counts were made for each concentration of
oil-dispersant emulsion and controls. Each count consisted
of the mean number of cells within six fields of a
hemocytometer. Counts were made every other day for the
first 4 days, then each day for the last 2 days. Care was
exercised in obtaining an even distribution of cells over the
counting grid.
RESULTS AND DISCUSSION
Figure 6 illustrates the results of this experiment.
Except for an apparent discrepancy at 800 ppm the growth
rates. of- Monochrysis populations were related to the
concentration of oil dispersant emulsion. Again the results
compliment the data from the Cl4 experiment Figure 3,
and the chlorophyll-a experiment. Figure 5, which
employed similar concentrations of the same emulsion
constituents. Due to the number of variables encountered,
no units of precision and accuracy are indicated. The
prescribed measurement of toxicity may be expressed as
the Median Inhibitory Limit, ILm, or the concentration of
any toxicant that produces a 50 per cent reduction in
growth rate. As with the previous techniques this bioassay
can produce meaningful data in itself, but would be of
greatest utility, if conducted in conjunction with Cl4 ir
chlorophyll-a bioasays.
"h
X
3
5
Figure 6: Population Growth Rates of Monochrysis Exposed to
Dispersant Crude Emulsion.
GENERAL DISCUSSION
While the field or in situ technique described at the
outset allows the researcher to study the response of
planktonic algae in a near natural environment, it is
recommended that parallel tests under controlled
laboratory conditions also be conducted. The yield of
information from both field and laboratory can then be
integrated into a more meaningful solution to the problems
associated with release of oil.
The tests as described in this report are of obvious
value in forcasting the effect upon phytoplankton stocks
through usage of the varying proposed treating agents and
application methods presently available. Toxicity data
derived from such recommended techniques prior to actual
field use will provide the basis for effective selection of
those materials or methods least toxic to aquatic life, and
for recommending or prohibiting their use. This need was
demonstrated by the misuse of dispersants following the
Torrey Canyon disaster.
SUMMARY
Bioassay procedures are presented that can be
routinely applied to evaluate the relative toxicity of oil,
chemical dispersants, and oil-dispersant mixtures to marine
phytoplankton. Toxicity data derived from recommended
procedures prior to actual field use of dispersant chemicals
will provide the basis for effective selection of those
materials least detrimental to the aquatic environment.
BIBLIOGRAPHY
(1) Boney, A. D. 1970. Toxicity Studies with an Oil^Spill
Emulsifier and the Green Alga, Prasinocladus marinus. J.
Mar. Biol. Assn. U. K., 50:461473.
(2) Carthy, J. D., and D. R. Arthuer, [eds.]. 1968. The
Biological Effects of Oil Pollution on Littoral Communities.
Suppl. to Vol. 2 of Field Studies. Field Studies Council,
London, Eng. - ;
(3) Chadwick, H. K. 1960. Toxicity of Tricon Oil Spill
Eradicator to Striped Bass, Roccus saxatilis. Calif. Fish
Game, 46, 373.
(4) Corner, E. D. S., A. J. Southward, and E. C.
Southward. 1968. Toxicity of Oil-Spill Removers
(detergents) to Marine Life: An Assessment Using the
Intertidal Barnacle, Elminius modestus. Jour. Mar. Biol.
Assn. U. K., 48,29.
(5) Doty, S. and M. Oguri. 1959. Selected Features of
the Isotopic Carbon Primary Productivity
Technique. Rapp. Froc.-verb, Cons. Internal. Explor. Mer.
144:47-55.
(6) Doty, S. and Oguri, M. 1957. Evidence of a
Photosynthetic Daily Periodicity. Limnology and
Oceanography, 2:37-40.
(7) Goldman, R. and Mason, D. T. 1962. Inorganic
Precipitation of Carbon in Productivity Experiments
Utilizing Carbon-14. Science, 136(1050): 1049-1050.
-------
286 TREATING AGENTS
(8) Harms, A. C., D. B. White, and R. B.
Macfarlane. 1970. Mercury Compounds Reduce
Photosynthesis by Plankton. Science 170(3959) :736-737.
(9) Jitts, H. R. 1962. The Standardization and
Comparison of Measurements of Primary Production by the
Cl4 Technique. Symposium on Marine Productivity in the
Pacific 10th Pac. Sci. Cong., Honolulu. §
(10) Jorgensen, E. G. and E. Steemann-Nielsen. 1965-
. Adaptation in Plankton Algae, p. 3746. In C. R.
Goldman (ed.), Primary Productivity in Aquatic
Environments. Mem. Inst. Ital. Idrobiol., 18 Suppl.,
University of California Press, Berkeley.
(11) Manual on Industrial Water and Industrial Waste
Water. 1965. 2nd Edition ASTM-Special Tech. Pub.
148-H, Philadelphia.
(12) McAllister, C. D. 1961. Observations on the
Variations of PJanktonic Photosynthesis with Light
Intensity, Using both the 02 and C*4 Methods. Limnology
and Oceanography 6(4): 483-484.
(13) Mironov, 0. G. 1968. Hydrocarbon Pollution of the
Sea and Its Influence on Marine Organisms. Helgo, wiss.
Mecresunters, 17,335.
(14) Odum, T., W. McConnell and W. Abbott. 1958. The
Chlorophyll "A" of Communities. Pub. Int. Mar. Soc.,
Univ. of Texas, 5:65-69.
(15) Portmann, J. E., and Connor, P. M. 1968. The
Toxicity of Several Oil-Spill Removers to Some Species of
Fish and Shellfish. Mar. Biol., 1,322.
(16) Richards, A. and G. Thompson. 1952. The
Estimation and Characterization of Plankton Populations
by Pigment Analysis II Spectrophotometric Method for the
Estimation of Plankton Pigments. Jour. Mar. Res.,
11:147-155.
(17) Rodhe, W. 1958. The Primary Production in
Lakes. Some Results and Restrictions of the C14 Method.
Rapp. et Proc^verb. Cons. Internal. Explor. de la Mer. Vol.
144.
(18) Ryther, J. H. 1954. A Comparison of the Oxygen
and C-14 Methods of Measuring Marine
Photosynthesis. Jour. de. Conseil, 20:25-37.
(19) Ryther, J. H. 1954. The Ratio of Photosynthesis to
Respiration in Marine Plankton Algae and its Effect Upon
the Measurement of Productivity. Deep Sea Research,
2:134-139.
(20) Senadecor, W. and W. G. Cochran. 1967. Statistical
Methods. Sixth Edition, Iowa State University Press, Ames,
Iowa, 539 p.
(21) Spooner, M. F. 1968. Preliminary Work on
Comparative Toxicities of Some Oil Spill Dispersants and a
Few Tests with Oils and Corexit. Marine Biological
Laboratory, Plymouth, Eng.
(22) Steemann-Nielsen, E. 1951. Measurement of the
Production of Organic Matter in the Sea by Means of
Carbon-14. Nature, 167:684-685.
(23) Steemann-Nielsen, E. and V. K.
Hansen. 1959. Measurements with the Carbon-14
Technique of the Respiration Rates in Natural Population
of Phytoplankton. Deep Sea Research, 5(3): 222-233.
(24) Steemann-Nielsen, E. 1952. The Use of Radioactive
Carbon (Cl4) for Measuring Organic Production in the
Sea. Jour, du Conseil., 18:117-140.
(25) Strand, J. A., J. T. Cummins and B. E.
Vaughan. 1966. Artificial Culture of Marine Sea Weeds in
Recirculation Aquarium Systems. Biological Bulletin,
131(3):487-500.
(26) Strickland, J. D. H. 1960. Measuring the Production
of Marine Phytoplankton. Bull. Fish. Res. Bdg. Can., 122,
p.172.
(27) Strickland, J. D. H. and T. R. Parsons. 1968. A
Practical Handbook of Sea Water Analysis. Bull. Fish. Res.
Bd. Can., 167, p. 311.
(28) Strickland, J. D. H. 1965. Phytoplankton and Marine
Primary Production. Annual Review of Microbiology, C. E.
Clifton (ed.), Annual Reviews Inc., Palo Alto, Calif.
(29) U.S. Department of the Interior. 1968. Report of
the Committee on Water Quality Criteris, FWPCA, U.S.
Government Printing Office.
(30) Van Norman, R. W. and A. H. Brown. 1952. The
Relative Rates of Photosynthetic Assimilation of Isotopic
Forms of Carbon Dioxide. Plant Physiology 27:691-709.
(31) Wilson, D. P. 1968. Temporary Absorption on a
Substrate of an Oil-Spill Remover (detergent): Tests with
Larvae ofSabellaria spinulosa. Jour. Mar. Biol. Assn. U. K.,
48,183.
-------
MICROBIAL DEGRADATION OF A
LOUISIANA CRUDE OIL IN CLOSED FLASKS
AND UNDER SIMULATED FIELD
CONDITIONS
Howard Kator, C. ff. Oppenheimer and R. J, Miget
Department of Oceanography
Florida State University
ABSTRACT
Petroleum utilizing microorganisms in flasks containing
enriched seawater exhibited a clear metabolic preference
for saturated paraffins in a Louisiana crude oil. The rates of
oxidation of these compounds were directly proportional
to incubation temperature and roughly doubled with a ten
degree increase. A pattern of growth consisting of an
initially large rate of saturated paraffin oxidation, followed
by a decrease and another increase in rate was observed.
The initially large rates were attributed to the metabolism
of n-paraffins smaller than C-18. No even or odd chain
length preference for n-paraffins was indicated. There was
no evidence of utilization for aromatic compounds.
Application of a microbial culture to an oil slick under
simulated field conditions, clearly showed that microbes
could accelerate the removal of a Louisiana crude oil from
an oil slick on seawater. The rates of oil removal in
outdoor, exposed conditions, were twice as large as the
rates of evaporative oil loss. The microbes produced a
significant change in oil "stickiness". Measurements
indicated the oil was dispersed through microbial activity.
The cells preferentially remained at the oil-water interface
during the experimental periods.
INTRODUCTION
The work reported in this paper complements an
earlier study1 to evaluate the feasibility of microbial
seeding to accelerate crude oil degradation in seawater.
This paper is composed of two sections. The first
concerns itself with metabolic studies performed to
determine which types of compounds in Louisiana crude oil
were more easily oxidized by mixed cultures of petroleum
degrading microorganisms. The second part presents
experiments in which large tanks were used to model oil
spills and microbial seeding.
Metabolic Studies
Introduction
Owing to the increased incidence of maritime oil spills,
our knowledge of the crude oil degrading capabilities of
microorganisms in seawater must be extended and
developed.
Microbial metabolic studies2,3 have indicated that
n-paraffins are the most labile hydrocarbons with branched
paraffins more resistant but more resistant but more easily
oxidized than either cycloparaffins or aromatics. Our
studies have shown that the microbial utilization of the
branched paraffin pristane (2,6,10,14-tetramethylpe-
ntadecane) in seawater, conformed to this pattern. While
the n-paraffins in crude oils were extensively degraded, the
pristane in the Louisiana crude oil was not metabolized.
However, pristane was rapidly oxidized when it was the
only source of carbon and energy in seawater.
An evaluation of the effectiveness of microbial crude
oil degradation on the sea surface should consider the
relative susceptibilities and rate of utilization of the major
chemical fractions in crude oils. Therefore, a standard
chromatographic procedure using activated silica gel4 was
used to fractionate degraded Louisiana crude oil into four
chemical groups; saturated paraffins (heptane eluate),
aromatics and naphthenes (both types of compounds elute
with carbon tetrachloride. and benzene), and "asphaltic"
compounds containing oxygen, nitrogen and sulfur
(methanol eluate).
287
-------
288
TREATING AGENTS
Methods
Microbially degraded oil samples were obtained
through the following procedures.
Selected mixed cultures (BHMO, OILRIG, SOCLA)!
were grown on enriched seawater (ESW, Appendix (A))
agar plates inverted over Louisiana crude oil. Afther 24
hours incubation at 25°C the cells were scraped off the agar
surface and suspended in sterile ESW to an optical density
of 0.1 (lO? to 108 cells/ml) Each suspension was used to
inoculate three of a series of four flasks. (1.0 ml/flask) each
containing 200 ml of sterile ESW. The fourth flask served as
a sterile control. One-tenth ml (71 ±2.5 mg) of Louisiana
crude oil was dispensed with a 100 microliter syringe into
all twelve flasks. The flasks were sealed to minimize
evaporation and incubated at 20°C. on a rotary shaker (160
rpm). An identical procedure was used to prepare another
series of flasks for incubation at 30°C.
The flasks were removed from incubation at
predetermined intervals and the water phase acidified to a
pH of 4 with concentrated HC1. Twenty-five ml of a
benzene-ether solvent mixture (2:1, v/v) was added to each
flask. Extraction proceeded for at least 24 hours at room
temperature. The organic layer was then washed with
acidified distilled water. The spent water phase containing
cells was re-extracted with 25 ml of the solvent mixture and
was normally colorless. Both organic extracts were
combined, dried through anyhydrous Na2S04, and the
solvent evaporated to dryness through aspiration.
The residual crude oil was transfered in a small volume
of heptane (0.5 ml) to a 9 mm ID. glass column containing
18 gm of activated silica gel. The sample was
chromatographed with distilled solvents of increasing
polarity. Eluted fractions were collected in tared aluminum
weighing dishes (weighed to nearest 0.1 mg) and the
solvents evaporated through gentle heating at 40°C. The
weights of the eluted fractions were then determined. These
data are presented in Table 1.
Observations
The most extensive weight changes occurred in the
heptane or saturated paraffin fraction. In contrast to the
other fractions which occasionally increased in weight, this
fraction consistently showed a weight loss. The maximum
weight loss obtained (18.6 mg, SOCLA at 30°C) was
equivalent to 55% of the control heptane fraction weight.
Changes in the average daily rate of weight loss in the
heptane fraction are illustrated in Figure 1. These curves
clearly show the direct dependency of the rates of weight
loss upon incubation temperature. The cultures incubated
at 30°C exhibited rates of weight loss at least twice as large
as the same cultures incubated at 20°C
SOCLA culture at 20°C
Fraction Control 27 hrs
(92 hrs)
Heptane 32.6 32.6
Benzene 10.5 9.4
Methanol 3.4 3.1
SOCLA culture at 30°C
Heptane 33.8* 33.8
Benzene 10.6 8.2
Methanol 4.8 3.6
*72 hrs
BHMO culture at 20°C
48 hrs
31.5
8.2
3.0
25.0
8.2
4.8q
92 hrs
26.1
15.2
8.0
5.2
Total % loss of
change control
-6.5 19
-2.3 21
-0.4 11
-18.6*
-2.6
-K).4
55
24
Fraction Control 24 hrs 48 hrs 96 hrs Total % loss of
(96 hrs)
Heptane
CC14
Benzene
Methanol
30.3
4.6
6.1
6.7
29.0
2.9
8.2
7.4
26.4
2.7
7.9
8.0
23.4
1.9
6.5
9.9
-6.9
-2.7
+0.4
+4.8
BHMO culture at 30°C
Heptane
CCI4
Benzene
Methanol
30.3
3.4
7.0
5.7
26.6
2.4
8.6
8.4
26.2
2.8
8.6
9.0
23.9
1.9
6.4
7.2
-6.4
-1.5
-0.6
+1.5
control
22
44
21
44
8
Table 1 (Continued)
-------
MICROBIAL DEGRADATION
289
Table 1
OILRIG culture at 20°C
Fraction Control 24 hrs 72 hrs 96 hrs Total % loss of
(96 hrs) change control
31
6
17
21
Heptane
CC14
Benzene
Methanol
31.9
4.4
10.8
8.2
28.9
5.2
8.5
5.9
26.9
8.8
10.4
7.3
21.8
4.1
8.9 q
6.4
-10.1
-0.3
-1.9
-1.8
OILRIG culture at °C
Heptane
CC14
Benzene
Methanol
31.9
3.4
9.2
6.1
24.1
4.0
7.8
5.9
21.9
5.5
9.8
6.7
18.2
2.9
8.0
8.3
-13.7
-0.5
-1.2
+2.2
42
14
13
Table 1: Weight (in mg's) Changes in Various Chromatographic Fractions
from Louisiana Crude Oil Produced Trhough Microbial Degradation
OILRIG, BHMO, and to a lesser degree SOCLA,
exhibited a cycle or pattern of change in their rates of
weight loss. During the initial growth period, the cultures
displayed their largest rates of weight loss in the heptane
fraction. A decleration in the rate of weight loss then
occurred which was followed by an increase in rate. The
BHMO culture grown at 20°C was probably repeating this
pattern over a longer time period. SOCLA, an oil^ositive
culture (grows and remains at the oil-water interface 1),
characteristically grows more slowly than the other mixed
cultures. Perhaps SOCLA would have displayed a more
developed growth pattern had the incubation period been
longer.
It is probable that the initially large rates of weight
loss, or saturated paraffin oxidation, were due to utilization
of the smaller, more water soluble paraffins. Gas
chromatograms of the heptane fractions indicated that only
n-paraffins smaller than C-18 were utilized during the early
growth periods. A shift in population produced by
requirements to metabolize larger, branched and normal
paraffins, or by the decreased solubility of the larger
paraffins, may explain the specific growth patterns
observed.
The fractions containing aromatic and naphthenic
compounds exhibited weight changes which were
interpreted to indicate insignificant microbial utilization of
aromatic and naphthenic compounds. Despite initial
decreases in the weight of the benzene fractions, consistent
weight losses did not occur. Also, weight changes in these
fractions showed no apparent dependency upon incubation
temperature.
UV monitored high speed column chromatography
(Appendix (B)) of these aromatic containing fractions,
indicated no substantial changes in the elution patterns of
the UV absorbing compounds following degradation. This
suggests that the observed weight changes in these fractions
may have been due to: (a) the production of large
molecular weight esters polar enough to elute with benzene,
(b) the oxidation of the alkyl side chains of the aromatic
rings causing a loss in fraction weight but not in UV
absorption, (c) oxidation of naphthenic compounds. The
first suggestion is plausible since the production of large
esters from n-paraffins is well documented,^ and IR
internal reflectance spectroscipic analysis of degraded crude
oil indicated the production of oxygenated material
absorbing in an ester region.
In contrast to the weight changes of the aromatic
containing fractions, the methanol eluted material showed
appreciable weight gains. Production of polar molecules no
doubt accounts for these weight increases.
The preference these petroleum degrading organisms
possess for n-paraffins suggests a concept similar to
diauxie.5 Diauxic growth is the sequential utilization of
preferred substrates from a mixture.
Additional support for diauxie has been the
observations that SOCLA, BHMO, OILRIG, and other
mixed cultures grew on and dispersed pure pristane and the
benzene fraction of Louisiana crude when n-paraffins were
not present (Table 2).
-------
290
TREATING AGENTS
Culture
Control
BHMO
TPLA
NOLA
C-63
SOCLA
OILRIG
Louisiana crude
24hrs
0*
slight
0
0
1
slight
slight
48hrs
0
3
2
2
2
3
3
Benzene fraction
24 hrs 48 hrs
0
0
0
0
2
slight
3
0
3
3
3
4
4
4
*Values refer to relative turbidity, i.e., 0=no turbidity, slight = optical density
less than 0.05, 1 = optical density 0.05 to 0.1, 2 = optical density 0.1 to 0.5,
3 = optical density 0.5 to 1.0, 4 = optical density greater than 1.0
Table 2: Growth of a Series of Mixed Bacterial Cultures on a Louisiana Crude Oil
and on the Benzene Fraction from the Louisiana Crude Oil
Gas chromatographic evaluation of the heptane
fractions (Figures 2 and 3) indicated microbial utilization
of the n-paraffins C-12 through C-30. No odd or even chain
length preference was evidenced and the sequence of
utilization was inversely related to chain length. The sums
of the peak heights for each heptane fraction (Table 3)
show a decrease in value with time. Although the sums
decreased more rapidly at the higher incubation
temperatures (OILRIG at 30°C), the final percentages of
n-paraffins oxidized were similar for all the cultures.
OILRIG
CONTROL
(96 hrs)
24 hrs
72 hrs
96 hrs
20°C
30°C
SOCLA
20°C
BHMO
9.60
9.07
CONTROL
(92 hrs)
7.29
CONTROL
(96 hrs)
inn4
9.38
8.16
27 hrs
6.92
24 hrs
S 74
7.04
3.87
48 hrs
4.88
48 hrs
3.34
3.11
92 hrs
2.84
96 hrs
441
Loss as % of
control
65
65
Loss as % of
control
61
Loss as % of
control
56
Table 3: Changes in the Peak Hieght Sums of the n-Paraffins C-12 to C-30
in Louisiana Crude Oil Following Microbial Degradation in Closed Systems.
Simulated Field Studies
Introduction
As an intermediate approach to field studies,
experiments were performed in large outdoor tanks
(Appendix (C)) containing 900 liters of seawater. Several
assumptions, basic to the concept of microbial seeding to
accelerate petroleum degradation, were examined using
these tanks. One assumption was that the seeded cells
would preferentially remain at the ofl^water interface.
Constituents within an "open", or unenclosed, system are
subject to dilution. Similarly, dilution could produce a
decrease in cell population at the oil-water interface. It
follows that the overall rate of oil degradation would then
be lowered. The other assumption was that significant oil
degradation could be measured in large volume outdoor
tanks. It was possible that extensive evaporation would
obscure oil removal produced microbiologically. Also, the
bacteria would be exposed to variations in sunlight
intensity and fluctuations in temperature. Rather than
attempt to control these parameters, a rigorous approach
was elected and the tanks placed outdoors unprotected.
-------
MICROBIAL DEGRADATION 291
11
10
20* C
01LRIG
IHMO
Tint ii diys
Figure 1: Changes in the Average Rates of Weight Loss in
the Heptane Fraction of a Microbially Degraded
Louisiana Crude Oil.
Methods
The difficulties in sampling an oil slick should be
obvious. Tank oil slicks were neither homogeneous nor did
the oil lend itself to discrete sampling. Since a statistical
approach was warranted, a symmetrical grid to assign
sample locations was superimposed over the tanks.
Surface ofl samples were obtained with glass slides
(9-12 samples/tank), fiberglass screens (6 samples/tank),
and Mason jars (5-6 samples/tank). Details of the sampling
procedures are in Appendix (D).
The ofl removed on glass slides was termed "sticky"
oil. Fiberglass screens and Mason jars removed more
complete surface oil samples consisting of both "sticky"
and dispersed or "non-sticky" ofl. Laboratory studies
demonstrated that "stickiness", or the quantity of ofl
adhering to a glass slide, declined during microbial ofl
degradation.
In the first tank experiment (#1), 50 ml of a
pre-evaporated Louisiana crude ofl was spilled in each of
two tanks. Pre-evaporation of the light weight crude oil
(vigorous aeration at constant temperature for 48 hrs)
reduced the concentration of the n-paraffins smaller than
C-15 and caused a slight increase in ofl density. This
treatment was used to decrease the evaporative ofl losses
encountered at air temperatures higher than 20°C.
Each tank was sprayed twice with 200 ml of a 10%
solution of (NH/4)2S04 (indicated as NU on Figures 4 and
5) giving a final concentration of 13 mg NH4+/1. By
comparison, NH4+ concentrations in Chesapeake Bay
ranged from 0.05 to 0.1 mg NH4+/1 in the surface water
near Annapolis.6 The inoculated tank was sprayed with 200
ml of a dense suspension of BHMO (IQl4 cells/ml)
previously grown for 24 hours in ESW on Louisiana crude
ofl.
In the second experiment (#2) each tank received 100
ml of Louisiana crude ofl. A BHMO suspension containing
IQlO cells/ml was used to inoculate one of the tanks after
both had been sprayed with 200 ml of a 10% solution of
(NH4)2S04.
OILRia
IO*C-Loul(l«iil
CONTROL
72 HOURS
— M HOURS
14
16 18 20 22 24 26
•-ParoKiB Mail Uigtfc
28
- CONTROL
- » HOURS
- M HOURS
14
1C W 20 22 24 26
•-rWfil Chill lllgtk
28
30
Figure 2: Changes in the Peak Heights of the n-Paraffins C-12 to
C-30 in a Louisiana Crude Oil Due to Microbial
Degradation. Incubation Temperatures are Indicated.
-------
292 TREATING AGENTS
Observations
Within a day after application of the BHMO culture,
the oil in the inoculated tanks (Experiment 1 and 2)
appeared dull and stringy. The oU in the control tanks
remained darkly colored and tended to form aggregates. If a
glass slide was dipped into the oil in the inoculated tanks,
then washed with benzene, a white film remained attached
to the slide. No similar fflm was detected at the oil-water
interface in the control tanks. Phase microscopic
examination of the film revealed a solid mass of cells
morphologically similar to the inoculum cells. Cell counts
(Appendix (E)) obtained during the course of the
experiments, indicated that the bacteria remained
preferentially at the oil water interface. These data are
shown in Table 4.
The changes in the amounts of surface oil sampled are
presented in Figures 4 and 5. Variations in water
temperature are indicated at the sampling times.
Microbial degration dispersed the pollutant oil so that
"stickiness' and aggregation decreased with time. The
decrease in "stickiness' was indicated by the smaller weights
of oil removed by the glass slides in the inoculated tanks. A
reduction in aggregation was shown by the generally lower
standard deviations in the inoculated tanks.
The initial average rates of oil removal were
consistently larger in the inoculated tanks (Table 5). The
rates of microbial oil removal were at least twice as large as
the rates of evaporative oil loss. Larger rates of microbial oil
removal, obtained in the first experiment, were probably
due to the smaller volume of oil added and the greater cell
density of the inoculum. Apparently, pre-evaporation was
not effective in reducing the concentration of low
molecular weight paraffins to a level where microbial
growth was limited.
Time after
(culture application)
One hour
(oil-water interface)
Tank Experiment 1
Inoculated
tank
Three days
(oil-water interface)
Tank
Time after
culture application
One hour
(mid-depth
One day
(oil-water interface)
(mid depth)
Two days
(oil-water interface)
(mid-depth)
Five days
(oil-water interface)
(mid-depth)
2x 105
cells/cm2
2x 105
cells/cm2
Experiment 2
Inoculated
tank
1.0 x 103
cells/ml
9.0 x 104
cells/cm^
1.0 x 103
cells/ml
3.7 x 104
cells/cm^
0.0
3.7 x 103
cells/cm^
0.0
Control
tank
0.0
0.0
Control
tank
0.0
0.0
0.0
0.0
0.0
0.0
0.0
*see Appendix for description of most probable
number technique.
Table 4: Numbers of Hydrocarbons Degrading Bacteria"
-------
MICROBIAL DEGRADATION 293
After one day, the rates of oil loss in the inoculated
tanks decreased to values similar to the rates of loss due to
evaporation. These results were similar to those obtained in
flasks where a decrease in the rate of saturated paraffin
oxidation followed depletion of the labile low molecular
weight paraffins.
The decrease in microbial rate of oil removal could not
have been due to limiting concentrations of NH4+.
NH4+-Nitrogen concentrations were always above 10 mg
NH4+/1, but competition between algae and bacteria for
phosphorous may have limited further microbial growth.
Algae were frequently observed growing on the walls of the
i tanks.
SOCLA
M°C-Lou!»l«u Crud.
CONTROL
41 HOURS
12 HOURS
II 2t 22 24
-P.raffi. Chaii Ltigtli
1.00
CONTROL
M HOURS
»• HOURS
-15 if it ' ' i'i ' ' *
••PoroHia Cbaii
Figure 3: Changes in the Peak Heights of the n-Paraffins C-12 to
C-30 in a Louisiana Crude OB Due to Microbial
Degradation. Incubation Temperatures are indicated.
The average percentages of oil remaining on the
seawater surface at the termination of the experiments are
shown in Table 6.
Gas chromatographic evaluation of the surface oil
samples showed that the BHMO cells remained active at the
oil-water interface during the experimental period. Only the
smaller n-paraffins (smaller than C-15) were utilized during
the final days of the experiment. The ultimate peak height
changes (Appendix (F)) are shown in Figure 6. The
numerical sums of the peak heights for each sample (Table
7) indicate the relative abundance of n-paraffins (C-12 to
C-30) remaining when the sample was obtained. Clearly,
microbial seeding was responsible for the accelerated
removal of these pollutant n-paraffins.
Or|»lc
Cirk*i
•••
1*00
1400 -.
1200-
1000-,
100
too
400
200
SCREENS
GLASS SLIDES
14*
IHOCULAYIO
•UTIIIIIITI NU
Oil
•I I
140
TIME IN DATS
Figure 4: Experiment 1. Loss of a Pre-evaporated Louisiana Crude
Oil Due to Microbial. Seeding of an Oil Slick Under
Simulated Field Conditions.
EXPERIMENT 1
Sampler Inoculated Tank
Slides 1.3 mg/day/cm2
Screens 8.5 ppmC/day/cm2
EXPERIMENT 2
Sampler Inoculated Tank
Slides 0.7 mg/day/cm2
Jars 4.8 ppmC/day/cm2
Control Tank
0.6 mg/day/cm2
4.0 ppmC/day/cm2
Control Tank
0.2 mg)day/cm2
1.2 ppmC/day/cm2
Table 5: Average Rates of Crude Oil Loss During the First
24 Hours After Inoculation
-------
294 TREATING AGENTS
Sampler
Slides
Screens
Sampler
Slides
Jars
EXPERIMENT 1
Inoculated Tank
3.0
4.0
EXPERIMENT 2
Inoculated Tank
19.0
9.0
Control Tank
44.0
56.0
Control Tank
100.0
36.0
Table 6: Average Percentages of Crude Oil Remaining on the Surface
at the Termination of the Experiments
MASON JAIS
GLASS SHOES
Figure 5: Experiment 2. Loss of a Louisiana Crude Oil Due to
Microbial Seeding of an Ofl Slick Under Simulated Field
Conditions.
12 H IS II 20 22 24 26 21 30
•-PifiHii Ckil. Uigtli
CONTROL IMOCULATEOfBHMO)
12
II
26 22 2< 2* 21 30
i-PinHi. C.iii ItMtfc
Figure 6: Changes in the Peak Heights of n-Parafflns C-12 to C-30
in a Louisiana Crude Oil Due to Microbial Seeding of an
Oil Slick Under Simulated Field Conditions.
Tank Experiment 1
0 time . Three days
Control Inoculated Control Inoculated
10.24 10.56 7.93 4.60
Tank Experiment 2
0 time One day Two days Five days
Con Inoc Con Inoc Con Inoc Con Inoc
11.85 12.18 10.80 10.29 9.83 9.33 8.95 4.30
Table 7: Changes in the Peak Height Sums of the n-Paraffins C-12
to C-30 in Louisiana Crude Oil Following Microbial Degradation of an
an Ofl Slick
-------
MICROBIAL DEGRADATION
295
CONCLUSIONS
Mixed microbial cultures degraded Louisiana crude oil
in both closed flasks and large seawater tanks. In simulated
field studies, the application of a mixed microbial culture
to an oil slick produced a measurable decrease in oil
"stickiness" and quantity on the water surface. The initial
rates of microbial oil removal were at least twice as large as
the rates of evaporation. The largest rates of oil removal
occurred during the initial growth periods. This was
attributed to utilization of n-paraffms smaller than C-l 5.
Cell counts indicated thats the seeded cells
preferentially remained at the oil-water interface during the
entire experimental period.
Closed flask studies showed a clear metabolic
preference of the hydrocarbon utilizing cultures for
saturated paraffins. The rates of oxidation of saturated
paraffins were directly dependent upon incubation
temperature. The largest rates of oxidation of saturated
paraffins occurred during the initial growth periods when
n-paraffins smaller than C-l 8 were being used. The range of
n-paraffin utilization was from C-l 2 to C-30. Aromatic and
naphthenic compounds did not appear to have been
metabolized.
APPENDIX
(A) Enriched seawater (ESW) contains 1 ppt
(NH4)2SO4,10 ppm K2HP04,and 5 ppm yeast extract. The
final pH was adjusted to 8.1.
(B) High pressure or high speed column
chromatography (HSCC) derives its title owing to the use of
a high pressure pump which moves solvent through the
column. Increasing the rate of solvent flow substantially
reduces the analysis period.
A UV monitor was used with HSCC to detect the
presence of aromatics eluting from the column. Using silicic
acid (stationary phase) and cyclohexane (mobile phase)
both the carbon tetrachloride and benzene fractions
showed characteristic aromatic elution patterns. No
significant alterations of these patterns due to microbial
degradation of the whole oil were observed.
(C) Plywood tanks (4'x4'x2') were constructed and
coated with epoxy paint. Sampling ports were located 10
cm below the water surface and at mid-depth. An overflow
tube was provided for flow-through circulation using
natural seawater. Two submersible pumps were located at
opposite corners of the tanks, approximately 10-15 cm
below the water surface. These pumps provided turbulent
movement of the upper water layers and the surface slick.
(D) Glass slides (area = 38.8 cm 2) were treated with
Siliclad* T. M. (a water soluble silicon solution produced
by Clay-Adams Co.). The slides were then immersed'
vertically to a constant level in the oil film. The oil adhering
was washed off with benzene into tared aluminum weighing
dishes. The solvent was gently evaporated and the residual
oil weighed.
Fiberglass screens (area = 122.8 cm2) were treated with
Siliclad. The screens were gently floated onto the oil slick,
removed, and transfered to a sterile Mason jar. The screens
were then mixed in a blender with seawater and tribasic
phosphate to emulsify the oil retained. Samples were then
removed for total organic carbon analysis. Duplicate screen
samples were mixed only in seawater and the hydrocarbon
degrading bacterial populations in the oil slick determined
with the dilution tube technique.
Glass Mason jars (one pint with a sampling area = 28.3
cm^) were used to obtain complete surface oil slick
samples. Mason jar lids were suspended by nylon lines in
the water before adding the oil to the tanks. Samples of the
surface slick were removed by threading one of the lines
through a 1/4 hole in the bottom of an inverted sterile
Mason jar. The jar was immersed through the oil slick until
it was approximately 3/4 full, the top was drawn to the
mouth tightly with the nylon line, and the jar was
withdrawn from the water. With the top firmly held in
place the nylon line was cut and the hole stoppered.
Water was then drained from the hole in the jar bottom
to a constant volume of 240 ml. The sample was mixed in
blender, and aliquots removed for bacterial enumeration.
The remaining sample was further emulsified in the blender
with tribasic phosphate for total organic carbon analysis.
(E) Dilution or most probable number technique was
used for cell enumeration. Bacterial cells were assumed to
be equally distributed in a volume of seawater. A volume of
this water was serially diluted by powers of ten in tubes
containing ESW overlain with Louisiana crude oil until
growth no longer occurred. The most probable number of
cells was equivalent to the dilution factor of the tube in
which growth last occurred.
(F) Pristane naturally occurring in the Louisiana crude
oil was used as an internal standard to calculate changes in
peak heights of the n-paraffins C-l 2 to C-30. Due to
evaporation in outdoor tanks the ratio of phytane to
pristane increased with time. In closed systems this ratio of
relatively resistant branched paraffins normally remained
constant. Occasionally, the increase in the ratio was even
larger in the inoculated tanks suggesting utilization as well
as evaporation. Although these changes were not very large,
the peak heights calculated using pristane as a standard
would be too small. To compensate only for biological
utilization, the quotient of the ratios in both tanks was
found and the peak heights in the inoculated tanks
corrected with this fraction.
REFERENCES
1. R. J. Miget, C. H. Oppenheimer, H. I. Kator, and P. A.
LaRock, "Microbial Degradation of Normal Paraffin
Hydrocarbons in Crude Oils," Proceedings-Joint
Conference on Prevention and Control of Oil Spills, 327,
(1969).
2. R. W. Stone, M. R. Fenske, and A. G. C. White,
"Microorganisms Attacking Petroleum and Petroleum
Fractions," J. Bacteriology, 39,91 (1940).
-------
296 TREATING AGENTS
3. A. C. Van der Linden and G. J. E. Thijsse, 'The 6. J. H. Carpenter, D. W. Pritchard, and R. C. Whaley,
Mechanisms of Microbial Oxidations of Petroleum "Observations of Eutrophication and Nutrient Cycles in
Hydrocarbons," Adv. Enzymology, 27,469, (1965). Some Coastal Plane Estuaries," In: Eutrophication:
4. W. G. Meinschein and G. S. Kenny, "Analysis of A Causes, Consequences, Correctives. Proceedings of a
Chromatographic Fraction of Organic Extracts of Soils," Symposium, National Academy of Sciences, Wash.,
Analytical Chem., 29,1153, (1957). D.C., 210, (1969).
5. C. Lamanna and M. F. Ma&ette, Basic Bacteriology, The
Williams and Wflkins Co., 1001 p., (1965).
-------
TOXICITY OF SOIL DISPERSING AGENTS
DETERMINED IN A CIRCULATING
AQUARIUM SYSTEM
Robert H. Engel and Marilynn J. Neat
William F. Clapp Laboratories, Inc.
ofBattelle Memorial Institute
Duxbury, Massachusetts
ABSTRACT
The toxicity of two non-ionic oil-dispersing agents was
determined on a number of marine species: the edible
mussel Mytilis edulis, winter flounder, soft shell clam,
mummichog, Atlantic silversides and fourth stage lobster
larvae.
The bioassay system used consisted of a series of
storage reservoirs and exposure tanks with a total volume of
112 liters. Water movement was provided by a series of
marine aquarium pumps which circulated water at a rate of 4
Kters/min. Additional aeration was not required for the
mummichog, mussel or fourth stage lobster larvae.
At 20°C, TLx's calculated from 24 to 96 hours fell
between 30 and 75 mg/1, with no significant difference in
toxicity between the two dispersants. A t 5°C, toxicity in
the mummichog was significantly lower; this may be
explained by the accompanying higher oxygen levels.
The advantages of the circulating aquarium system in
relation to the static and continuous-flow bioassay systems
are discussed.
Aquatic Bioassay Method
Aquatic bioassay methods for the evaluation of acute
toxicity have routinely been based on the use of static
systems/1) Usually, the fish species is introduced into a
series of tanks containing 5 to 10 gallons of water and
various concentrations of the test chemical, and the
appearance of toxic effects (e.g., loss of equilibrium,
abnormal gill movements, death) is noted over a 96-hour
period. The main advantage of this method is that the
procedures are fairly simple and widely applicable in many
laboratories; hence, their general acceptance.
On the other hand, the static bioassay system is
recognized as having a number of inherent disadvantages.
First, the renewal of dissolved oxygen takes place only
through surface absorption, and in many cases this
absorption is inadequate to maintain the recommended
minimum dissolved oxygen levels (5 ppm for cold-water
fish), particularly when chemicals having a high biochemical
oxygen demand are being studied. Oxygen depletion can be
overcome by aeration; this must be carefully controlled and
continuously monitored in order to avoid supersaturation.
However, aeration introduces a second disadvantage, the
excessive loss of any volatile components that may affect
toxicity. Although these materials are volatilized at a
natural rate from the water surface, aeration can greatly
acceleiate this loss and consequently reduce the toxicity
that would have been evident under natural conditions.
A third disadvantage affects the system in the opposite
direction, that of increasing toxicity. This is the constantly
changing chemical environment brought about by the
species itself, namely, increasing carbon dioxide levels as a
result of respiration (leading to a fall in pH) and increasing
ammonia levels as a result of excretion. This problem is
often met by daily renewal of the test solutions.
It is known that all of these disadvantages can be
avoided by the use of a continuous-flow system. In this
system a large reservoir of the test water and stock solutions
of the toxic chemical are used to continually renew the
water in the test container. Dissolved oxygen is maintained
at acceptable levels, aeration is not required and toxic waste
products do not accumulate. Unfortunately, these
*Research sponsored by the Commonwealth of Massachusetts,
Division of Water Pollution Control, Project No. 69-6.
297
-------
298 TREATING AGENTS
procedures are somewhat unwieldy and beyond the
physical capabilities of many laboratories. Consequently, in
the interests of procedural uniformity they are generally
not recommended for routine application(2). Also, when
oil-dispersing chemicals are being tested, this system has the
disadvantage that steady addition of the dispersant
continually renews its volatile solvent component. This
component, which has been shown to account for most
dispersant toxicity(3), is normally lost through evaporation
within the first 48 hours after application, and any species
which can withstand this initial exposure will usually
survive. Continuous renewal would tend to distort the
results in the direction of higher toxicities. Ironically, it is
an advantage of the static system that solvent evaporation
proceeds as in the natural aquatic environment.
Between these two extremes there is a third system,
the use of which seems to have received very little
attention; this is the circulating aquarium system. It would
appear that this system may offer some distinct advantages,
particularly in relation to the study of the toxicity of
oil-dispersing chemicals. As in the case of the
continuous-flow system, dissolved oxygen levels, aeration
and build-up of toxic waste products need not concern the
experimenter. Also, the single addition of dispersant at the
start of the experiment permits the effect of the natural
volatilization of the solvent component to be reflected in
the results. Thus, it would seem that by studying the
toxicity of oil-dispersing chemicals in a circulating
aquarium system, one could combine the advantages of
both the static and the continuous-flow systems while
avoiding the disadvantages of each.
In this study, a circulating aquarium system was used
to study the toxicity of two non-ionic oil-dispersant
chemicals on a number of marine vertebrate and
invertebrate species. The dispersants used were (A)
Aquaclene-100 (Metropolitan Petroleum Petrochemicals,
Inc., Boston, Mass.) and (B) CoIloid-88 (a product of
Colloid Chemical Co., Brockton, Mass).
The marine species studied were the mummichog,
Fundulus heteroclitus; Atlantic silversides, Menidia
menidia; winter flounder, Pseudopleumnectes americanus;
the soft shell clam, Mya arenaria; the edible mussel,Mytilis
edulis; and the fourth larval stage of lobster, Homarus
americanus. All species, with the exception of the lobster
larvae, were collected by the Clapp Laboratory staff from
Duxbury Bay and held in the laboratories' 24-hour
continuous-flowing sea water system until use. Fourth stage
lobster larvae were generously supplied by Mr. John Hughes
of the Massachusetts State Lobster Hatchery on Martha's
Vineyard. The larvae were brought to the laboratory
packed in ice and assays begun within 16 hours.
Circulating Aquarium System
The bioassay tanks were constructed by 1/4" plexiglass
sealed with ethylene dichloride; the dimensions are shown
in Fig. 1. These tanks were designed to be easily converted
from a circulating system to a continuous-flow system.
Hence, their physical arrangement is more involved than
necessary for just a circulating aquarium system. The
operating volumes of the reservoir and exposure tanks were
76 1 (20 gal.) and 36 1 (9.5 gal.), respectively. All internal
seams were'sealed with a silicone rubber aquarium sealer
manufactured by Dow Corning Corporation, Midland,
Michigan. This material is inert in sea water and does not
dry out when the tanks are not in use. The tanks were well
cured in sea water before use.
For the circulating aquarium system, a series of six
reservoir tanks and six exposure tanks was connected with
Tygon tubing, as shown in Figs. 2 and 3. Plastic screening
across exit holes of the exposure tank prevented the smaller
species from entering the reservoir tank. Circulation was
provided by Aquamaster aquarium pumps (Model PL, E. G.
Danner Mfg. Inc., Brooklyn, N.Y.), operating continuously
during the assay period at a pumping rate of 4
liters/minute. This rate resulted in a circulation time of
approximately 20 minutes for the entire 112 1. No filtering
material was used in the filter box. The bioassay
temperature was maintained at 20°C in each system with a
single 10" aquarium heater. During the warmer summer
months the laboratory was air-conditioned to below 20°C.
A number of experiments were carried out at 5°C by
placing the bioassay apparatus in a constant-environment
room maintained at that temperature.
17"
k
-23"-
Overflow tube
1.5" 1.0.
Alt other tubing
0.5 " I. D.
k—11.5"-*]
Reservoir Tank
J
-27.5"-
—11.5"-
All tubing
0.5" I.D.
Exposure Tank
Figure 1: Dimensions of Bioassay Tanks
Reservoir Tank
Figure 2: Circulating Aquarium System
-------
TOXICITY OF OIL DISPERSING AGENTS .. .
299
Figure 3: Circulating Aquarium System in Operation
The basic bioassay procedure was as follows:
mummichog, silversides and flounder were fasted 48 hours
prior to the experiment. Soft shell clams and mussels were
maintained in flowing sea water and used within 48 hours.
Species were placed in the exposure tanks (at least 10
specimens per concentration) and sufficient time allowed
for the circulating system to equilibrate to 20°C. (up to 24
hours). Because of the natural cannibalism of fourth stage
lobster larvae, it was necessary to isolate the individual
specimens in the exposure tank. Each larvae was therefore
placed in individual glass tubes, 2 inches in length, covered
at each end with a small piece of plastic screening. This
procedure permitted free movement of the larvae, open
circulation through glass tube and the identification of each
molt during the assay period.
Following withdrawal of an initial water sample, the
appropriate weights of dispersant were added to the
reservoir tanks of five of the systems, the sixth serving as
control, and the tanks maintained in this condition for 96
hours. Oxygen levels and mortalities were determined for
each concentration at 24,48, 72 and 96 hours.
Median tolerance limits were calculated by means of
straight line graphical interpolation on semi-logarithmic
coordinate paper as described in Standard Methods. In each
case, at least two experiments were required to determine
the TLm and all data obtained were combined into a single
plot. All experimental points falling between 5% and 95%
survival were plotted except in those instances when the
oxygen level fell below 5 ppm.
Results and Discussion
The experimental work in this study was carried out
between January and December 1970. The characteristics
of Duxbury Bay water during this time is shown in Table 1.
Only oxygen exhibited a cyclical pattern, falling to the
lower limits during the summer months.
AVERAGE
RANGE
VARIATION
pH
7.71
7.45-7.98
7
ALKALINITY
(MG/I CaC03)
103.9
96.6-109.0
11
HARDNESS
(MG/I CaC03)
5,823
5,410-6,860
21
OXYGEN
(PPM)
7.70
5.06-10.50
42
TABLE 1
Of the species studied, the mummichog, the edible
mussel and fourth stage lobster larvae could be maintained,
without aeration, at 20°C for 96 hours at oxygen levels
above 5 ppm (Fig. 4). Dissolved oxygen varied from 5 to
7.8 pp. The data for mummichog is shown in'Fig. 5. At
20°C, dissolved oxygen varied from 5 to 8 ppm and at 5°C,
from 7 to 12 ppm. The average total weight of mummichog
was 80 mg/1, well below the 2 g/1 recommended for the
static bioassay system. Similar data for the edible mussel
and the fourth stage lobster larvae are shown in Figs. 6 and
7. In each, dissolved oxygen was easily maintained above 5
ppm during the 96-hour period. In the case of Atlantic
silversides, a species requiring higher oxygen levels,
continuous aeration was used at 20°C (Fig. 8). This was
done in order to insure that the data on the dispersant
chemicals would be obtained under adequately oxygenated
conditions. The results would indicate that aeration was
probably unnecessary, oxygen levels averaging above 7
ppm. With studies conducted at 5°C, no aeration was used,
and the system remained fully oxygenated. The average
total weight of silversides was .35 g/1.
Aeration was required for bothflounder and soft shell
clam (Figs. 9 & 10), although the latter required only 20
minutes a day. In the case of the flounder, the average total
weight of the fish was 25 g/1.
Median tolerance limits (TLm's) of the species tested
are presented in Table 2.
12
10
2
Day
Figure 4: Dissolved Oxygen Levels for Species Maintained Without
Aeration. The Variation Shown is the Total Range.
-------
300 TREATING AGENTS
Figure 5: Dissolved Oxygen Levels for Mummichog at 5 and 20
12
IO
I
1123
Day
Figure 6: Dissolved Oxygen Levels for Edible Mussel
Figure 8: Dissolved Oxygen Levels for Atlantic Silver sides at 5 and
20°C.
Figure 9: Dissolved Oxygen Levels for Flounder
12 i 1 1 T
Figure 7: Dissolved Oxygen Levels for Lobster (4th Stage Larvae)
Figure 10: Dissolved Oxygen Levels for Soft Shell Clam
-------
TOXICITY OF OIL DISPERSING AGENTS ... 301
The 96-hour TLm's of all species appear to be very
similar (from 25 to 70 mg/1), and there would seem to be
no essential difference in toxicity between the two
dispersants. Portmann and Conner (3), reporting on the
toxicity of a dozen dispersing agents to shrimp, shore crabs
and cockles, found 48-hour TLm's to be generally below
100 mg/1. They also noted that there appeared to be little
difference in toxicity between species, an observation borne
out by the present study.
The short term, 24-hour toxicity found in the case of
mummichog, silversides, flounder and lobster larvae
suggests that the toxicity is due to the relatively volatile
solvent fraction of the oil dispersant. This was further
indicated by placing mummichogs in dispersant solution
that had been circulating four days. No mortaility occurred
during 48 hours at the TLm of the mummichog. Thus, as
with most dispersant chemicals, toxicity appears to be due
primarily to the solvent rather than the emulsifier.
SPECIES
MUMMICHOG
ATLANTIC .
SILVERSIDES
WINTER
FLOUNDER
SOFT.SHELL
CLAM
MEDIAN
DISPERSANT AT 24 HOURS AT
A
B
A
B
A
B
A
B
EDIBLE MUSSEL A
B
LOBSTER
(4TH STAGE)
A
B
•SUPPLEMENTAL AERATION
TEST TEMPERATURE: 20 C
FIGURES IN PARENTHESES
0 AND 100% SURVIVAL.
60
(70)
26
35
40
47
>)40
>120
>IOO
>100
54
50
PROVIDED.
ARE BASED ON FEWER
TOLERANCE
41 HOURS
50
(70)
25
32
(31)
46
71
>100
95
LIMIT. TL, (MG/1)
AT 72 HOURS
(44)
(70)
25
32
(31.
46
76
(45)
56
43
46 46
46 46
THAN 5 CONCENTRATIONS
AT 96 HOURS
(44)
(70)
25
32
(3»)
46
(50)
(45)
3)
51
46
BETWEEN
TABLE 1
Both molluscan species tested showed an increasing
toxic response to the dispersants during the 96-hour assay
period, as evidenced by the lower TLm on each successive
day. The cumulative effect for molluscan species may
indicate a different mechanism of toxicity, perhaps
involving the emulsifier.
In the case of the lobster larvae, it was noted that glass
tubes containing a dead larva usually contained an
accompanying molt, while very few molts were found
associated with the surviving larvae. This would indicate
that lobster larvae are particularly sensitive to these
dispersants immediately after molting.
The results of bioassays conducted at 5°C are
summarized in Table 3. Two opposing effects in^ toxicity
can be expected when running experiments at 5°C versus
20°C. First, the lower metabolic rate of the species involved
would presumably decrease the toxicity, as assimilation of
the toxic material would not occur as rapidly. This effect
would tend to be offset by the slower rate of evaporation at
the lower temperature, thereby maintaining a higher
concentration of the toxic component during the course of
the experiment. Between 5°C and 20°C no essential
difference in toxicity was seen with silversides. The
mummichog appeared to be much less sensitive to the
dispersant at 5°C which may have been due to the lower
metabolic rate at that temperature. It would seem that
there is little justification for incorporating temperature
studies into a routine toxicity program, as the effect on
each particular species would have to be determined
individually. For routine screening, tests conducted at the
highest inshore summer temperature as recommended by
LaRoche et al (4) should be adequate.
SPECIES
MUMMICHOG
ATLANTIC
SILVERSIDES
TEMPERATURE
5
20
5
20
MEDIAH
AT 24 HOURS AT
no
HOUR!
200
50
23
25
LIMIT. TL_ (MG/1)
AT 72 HOURS AT
(146)
(44)
!<
25
96 HOUR!
(191)
(44)
(19
(25)
TABLE 3
As marine zooplankton appear to be extremely
sensitive to these chemicals, (Calanus flnmarchicus and
Acartia clausi, two important food species, succumbing
within one hour at concentrations of 50 and 25 mg/1,
respectively), the toxicity of both dispersans toward marine
plankton was tested at a dispersant concentration of 30
mg/1, the TLm of Atlantic silversides. This exposure was
carried out under static conditions on plankton tow
samples without aeration. Microscopic examination
revealed a population dominated by copepods and nauplii,
the latter being more numerous. Polychaete larvae were also
fairly common and there were small numbers of cladoceras
nematodes, foraminifera and phytoplankton. All organisms
were alive and vigorous. Twenty-four hours after the
addition of each dispersant, 90% of the organisms were
dead or moribund. It appeared that larval polychaetes were
more resistant than other organisms. The importance of
these species in marine food webs, the rapid appearance of
toxicity and the ease with which marine plankton can be
handled suggest that further consideration should be given
to including plankton grab samples in future programs of
toxicity testing.
The circulating aquarium system used in this study was
designed to be easily converted to a continuous-flow
system, with either separate compartmentalized units or a
single large water reservoir. The result was a design which,
at times, became unwieldy to work with, particularly
during cleaning. For most of the species tested, there would
seem to be little reason to increase the size of the assay
vessel beyond the 36 liters contained in the exposure tanks.
Plastic tanks of this size with attached pumps should be
adequate for most species except those requiring more
water and circulation, such as flounder. Aquarium systems
are easily maintained and do not require the larger working
areas and attention of continuous-flow systems. The
constant levels of dissolved oxygen and the more natural
rate of dispersant volatilization suggest that this system is
particularly suitable for bioassay of oil-dispersing chemicals.
Mention of commercial products does not imply
endorsement.
-------
302 TREATING AGENTS
REFERENCES 3. J. E. Portmann and PM. Conner.'The Toxicity of
Several Oil-Spill Removers to Some Species of Fish and
1. "Standard Methods for the Examination of Water and Shellfish," Marine Biol. 1 322-329(1968).
Wastewater", 12th edition, American Public Health . r T oDrt. „ D -.. „„* r M T-, ,«™n "n-^,,c ,
. . ' v, v,, /tntc\ CAC 4. O. LaRoche, R. bisler and C. M. Tarzwell, Bioassay
Association, Inc., N.Y.C. (1965), p 545. Procedures for Oil and Oil-dispersant Toxicity Evaluation,"
2. Ibid., p. 562. J. Water Poll. Cont. Fed. 42 1982-1989 (1970).
-------
OIL SPILL TREATMENT WITH COMPOSTED
DOMESTIC REFUSE
Walter G. Vaux, Stephen A. Weeks,
Donald J. Walukas
Industrial Ecology Research
Westinghouse Research Laboratories
Pittsburgh, Pennsylvania 15235
ABSTRACT
Floating crude oil can be absorbed and recovered with
compost made from domestic refuse. Experiments showed
that compost floats on water without wetting until it
encounters oil, then absorbs oil at 3.4 ml crude/gram
compost (19 barrels/ton).
Oil-saturated compost forms cohesive masses which are
easily retrieved from water. Floating masses of oily
compost bum vigorously and leave a coke-like residue
which sinks. Oily compost can be sunk; underwater it
breaks into small suspended particles which disperse and
degrade.
Ocean tests off San Diego demonstrated that very thin
and thick (1.5 mm) films can be treated and removed
quickly.
This method can be applied to (i) absorption and
recovery, (ii) absorption and sinking, (Hi) absorption and
ignoring. Treated oil when left afloat is non-adhesive and
will not stain vessels or wildlife, compost will aid
decomposition of the sequestered oil which washes ashore.
Retrieved oily compost may be burned at sea or on shore.
Economic studies show the use of compost to be
competitive. Compost is inexpensive, continuously
available, stable, easily transported and distributed at sea.
INTRODUCTION
The idea of treating oil slicks with composted refuse
arose in a formal brainstorming session. Two researchers
had independently noticed that compost is difficult to wet,
yet it readily absorbs oil. The conclusion that compost
might absorb floating oil led to bench-top experiments
which showed the surprising effectiveness of compost in oil
spill treatment.
In the lab experiments compost sprinkled over oil
floating on water in a one-liter beaker quickly absorbed the
oil and formed cohesive sponge-like masses. The masses
remained intact and floating after agitation. Quantitative
measurements of compost's absorption capacity for pump
oil — no crude was available then — showed a capacity of
2.8 ml oil/gram of compost or 16 barrels of oil absorbed
per ton of compost.
Compost: Character, Availability
Cura brand compost, used in all of our tests, was
manufactured from domestic refuse by the International
Disposal Corporation of St. Petersburg, Florida. The
composting process includes magnetic, ballistic, and hand
separation of non-compostables, then grinding, composting,
drying and final grinding. Composting is aerobic and, in the
five-day reaction, temperatures rise to 170°Fwith an earthy
odor.
The St. Petersburg plant's daily capacity is conversion
of 100 tons of refuse to 70 tons of compost.
Oil Spill Treatment Method
Absorption Experiments
We evaluated compost along with two other common
and somewhat similar absorbent candidates. The oil used
was a sample of African Crude supplied by Gulf Research.
The absorbents tested were Cura brand compost, fine
sawdust with some coarse shreds, and oven-dried peatmoss.
Crude was floated on water in 1000 ml beakers.
Absorbents were added in slight deficiency. When the
absorbents were saturated — about 10 minutes at 20°C —
the clumps formed were removed with a wire screen. After
allowing the excess oil to drip from the screens for five
minutes, the volume of unabsorbed oil was measured. The
303
-------
304 TREATING AGENTS
results of these measurements are summarized in Table 1.
Table 1:- Results of Crude Oil Absorption Tests
Vol oil absorbed/mass of absorbent
ml/g mean bbl/ton
Absorbent
Compost
Sawdust
Peatmoss
3.7
3.1
6.5
8.1
2.5
3.8
3.4
7.3
3.2
19
42
18
The results show that there was no significant difference in
the capacities of compost and peatmoss. However, the
capacity of sawdust was double the capacity of compost or
peatmoss.
Each absorbent took up oil to its full capacity since it
was spread directly on a continuous oil surface. Compost
and peatmoss are difficult to wet with water and float until
they encounter a patch of floating oil. Sawdust, on the
other hand, wets immediately and sinks within five seconds.
Unless sawdust can be placed directly on a continuous film
of oil its efficacy will be limited.
Burning of Oil Soaked Compost
Burning of spilled oil is discouraged, particularly near
populated shores. The sooty smoke from possible
incomplete combustion may cause secondary pollution in
the air. Yet we can envision situations, — say far at sea, or
when retrieval equipment is unavailable, — where it would
be better to rid oil from the water before it dispersed too
widely.
Oil burning was first tested in the laboratory in a
beaker. The intensity of the flames and smoke quickly
ended the indoor testing.
In a three-square-foot outdoor water trough, 1500 ml
of floating crude oil was absorbed into about 500 grams of
compost. Ten minutes after compost application, the
saturated mass was ignited.
The oil burned vigorously on the water and generated
dense black smoke. After ten minutes the oil combustion
stopped very suddenly. A coke-like residue remained. It
sank.
Biological Degradation
A beaker of oil-soaked compost in water has been kept
at room temperature for several months. One month after
the beginning of these observations fungus invasion of the
mass was evident. The mass then broke into small — about
10 mesh—particles which suspended in the water. The
particles were non-adhesive. Subsequent aerobic activity
was indicated by the odor of suspended particles. After
several months particles were still in suspension and
non-adhesive. No free oil was evident at any time.
Field Tests At San Diego
Westinghouse Ocean Research Laboratory scientists
tested the compost absorption method at sea on 28
October 1970. During the tests the sea was calm with less
than a 4 knot wind. Signal Oil Company provided
Huntington Beach crude oil for the test. The Cura brand
compost was assayed at 14% moisture; above the 5%
normal moisture, because of heavy dew and rain before the
test. Test slicks were overtreated because of Coast Guard
surveillance and sensitive public concern at the time.
In an initial test one gallon of crude oil spread to a
circular film 120 feet in diameter. Average slick thickness
was 0.00014 inches. The crew of a small boat broadcast
compost over the slick. Although there was no clump
formation, oil was soaked up wherever it contacted
compost particles. Floating compost and oil were collected
in a plywood vee suspended between the twin hulls of the
recovery vessel R/V MIDWIFE. The 1/4 inch mesh at the
vee allowed oily compost to escape and only one quarter of
the oily compost was recovered.
In a second test one gallon of crude was treated with
26.5 Ib of compost after the slick had spread to a six-foot
diameter circle. Average slick thickness was 0.06 inches. All
of the oil was covered and formed into clumps 2 to 3 inches
in diameter. As the clumps dispersed, no oil was visible.
All floating clumps were recovered within 15 minutes.
No trace of oil or compost remained. The retrieval system
recovered 16.5 Ib of oily, wet compost. The remainder
sank.
In a final test one gallon of crude in an 8 foot diameter
circle was treated with compost. The floating material was
sprayed with seawater and sank. Churning the
compost-treated slick with the small boat's engine proved
effective in sinking all traces of oil and compost.
Two hours and twenty minutes after the first test, all
experiments were completed and all traces of the several
slicks were gone.
The results of these experiments show that compost
does absorb floating oil in very thin or heavy films, and that
all remnants of a treated slick can be sunk by spraying or
agitation.
Compost Distribution Tests
The primary candidate for broadcasting compost at sea
is the snowblower. A machine has been tested and it picks
up, transports, and broadcasts compost in the same
effective manner that it handles snow.
The snowblower is well suited to skid mounting for use
on a boat or barge. Either bulk or bagged compost could be
blown over an oil spill with a minimum of compost
handling or labor.
DISCUSSION
Other Absorbents
Today's most prevalent absorbent is straw. San
Francisco treated its January, 1971 spill of 800,000 gallons
with straw.
-------
COMPOSTED DOMESTIC REFUSE 305
The State of Maine has prepared a contingency plan for
oil spill prevention, containment, and cleanup. 1 The plan
explains that, "straw is not necessarily the best absorbent
available, but it is quite definitely the cheapest. We have
found that it is very difficult to obtain straw in the State of
Maine." The cost of baled straw, F.O.B. the farm, is close
to $10.00/ton at the minimum. Straw absorbs five times its
weight in oil.2
Other absorbents include coated talc, polyurethane
foam, perlite, and pine bark.
Cost Comparison with Existing Treatments
Gilmore^ et. al., give cost estimates for oil spill cleanup
of several techniques. These include a sinking material
(treated chalk) at $44 per barrel, and straw absorbent
which is recovered and buried on shore at $18/barrel.
recovered and buried on shore at $18/barrel.
To recover the oil soaked straw aboard ship costs
$7.10 per barrel. This cost includes: (1) $50 per ton of
straw delivered to port, (2) $5 per hour loading cost, (3)
$60 per ton loading cost, and (4) recovery costs of oil
soaked straw at $64 per ton of applied straw. Thirty tons of
straw is assumed to absorb 1000 barrels of oil. The cost
estimate allows for a 30% excess application which results
in a total application rate of 39 tons per 1000 barrels.
To treat an oil spill with compost and to recover the oil
soaked compost aboard ship costs $6.10 per barrel of oil
spilled. These costs include: (1) $30 per ton of compost
delivered to port (This includes a credit for regular handling
costs paid by the disposal company),(2) $1 per ton loading
costs (by snowblower), (3) $18 per ton application to oil
spill (by snowblower), and (4) $29 per ton recovery costs
(by purse seiner). Allowance is made for 48% excess
treatment and thus a application rate of 78 tons of compost
per 1000 barrels of oil spilled.
Various Ways of Applying the Method
The results of at-sea tests off San Diego suggest several
ways in which the method can be applied.
Probably the best protection to our water and shore
environments would be through treatment and recovery of
oily compost. The large clumps of oily compost are easily
retrieved by a rigid net towed through the water.
In the absence of danger to shellfish beds, a second
technique is to absorb and sink. Long-term laboratory
tests have shown that oil is not released from compost, but
that the oil-compost mixture suspends in water and
degrades. No free oil is released and the suspension particles
are not adhesive.
A third possibility is to absorb and ignore, perhaps the
only possibility in an immediate threat to beaches, resorts,
estuaries, or populous areas. Unlike oil-soaked straw, the oil
soaked compost forms non-staining clumps or particles
which will not stain vessels or adhere to birds and animals.
Waves and wind action will serve to sink the treated compost
which will disperse.
A fourth possibility is to allow oily compost to wash
ashore and plow it into the beach sand. Under aerobic
conditions the compost will aid decomposition in much the
same way that oily bilge water is decomposed in soil along
the Gulf Coast.
Utilization of Recovered Compost
Much of the proposal for using recovered compost is
conjecture and we can at present list only practicable
possiblities.
Tests have shown that retrieved oil-soaked compost
burns completely and that the compost mat remaining after
recovery by squeezing burns cleanly in air. Either could be
used as a fuel at sea or on shore.
Recovered oily compost could be disposed of
aerobically by incorporation into the soil. Applications of
5.00 to 1000 tons per acre could degrade without
introduction of hydrocarbons into the groundwater. Soil
would be recoverable for farming within one year.
CONCLUSIONS
1. Compost, formed from domestic refuse, is
hydrophobic, and oleophilic. It is effective in absorbing
floating oil.
2. Oil soaked compost floats, but can be sunk by
spraying or agitation.
3. Oil soaked compost initially forms into
sponge-like masses which can be recovered from the water.
4. Compost oil masses eventually break up into small
particles which suspend in water. Neither the large masses
or fine particles will stain vessels or wildlife. The oily
compost degrades biologically.
5. Compost-treated crude oil burns vigorously on
water leaving a coke-like residue which sinks.
6. Tests at sea demonstrated that spilled oil can be
treated, then recovered or sunk quickly.
7. A commercial snowblower is effective in compost
distribution.
8. Recovered compost can be burned either as
collected or after the bulk of absorbed oil is pressed out.
REFERENCES
1. Portland Harbor Pollution Abatement Committee,
1970. Oil and hazardous materials contingency plan for
prevention, containment and cleanup for the State of
Maine. 40 Commercial St., Portland, Maine, 35 p.
2. Chemical Engineering News, 1970. Dillingham plant
attacks oil spill cleanup problem. July 27, p. 34-36.
3. Pattison, D.A., 1969. Oil spill cleanup: a matter of
$'s and methods. Chemical Engineering, V. 76, N. 3, Feb.
10, P. 50-52.
4. Gilmore, George A., et. al., 1970. Systems study of
oil spill cleanup procedures, Dillingham Corporation.
American Petroleum Institute, New York.
-------
PHYSICAL REMOVAL AND CONTAINMENT
Chairman: A. Cywin
Environmental Protection Agency
Co-Chairman: H. Bernard
Environmental Protection Agency
-------
A STUDY OF THE PERFORMANCE CHARACTERISTICS
OF THE OLEOPHILIC BELT "OIL SCRUBBER"
J.P. Oxenham
Shell Pipe Line Corporation
Research and Development Laboratory
ABSTRACT
Analyses and experimentation have indicated that the
maximum recovery rate of an oleophilic belt oil recovery
system is generally limited by the rate at which oil may be
transferred to the belt surface and interior. The rate of
absorption of oil by an oleophilic belt increases with
increasing specific surface and permeability of the belt
material, increasing slick depth, decreasing oil viscosity, and
decreasing interfacial tension between the oil and belt
material In operations with high viscosity oils and high belt
speeds significant quantities of oil may be withdrawn on
the belt's outer surface. The oil scrubber's performance is
not detrimentally affected by the presence of waves, nor by
the presence of solid materials, emulsions, or "rag" in
limited quantities. The stability of the belt is a primary
concern for operations in the presence of transverse
currents.
Oil slicks may be removed from the surface of water by
several methods. The oil may be burned on the water's
surface, sunk by the application of a dense oleophilic
material of large surface area, or emulsified by the
application of a detergent. After each of these procedures,
oil residues remain on the surface, bottom, or within the
water for some time after the removal operation. The
alternative is to recover and separate the oil from the water
for transport to a remote location for disposal. This may be
accomplished directly by the use of suction or weir type
skimming devices, or, indirectly, by first chemically or
physically modifying the slick to facilitate its recovery. To
date, skimming devices have proven very inefficient due to
the undesirably large amounts of water obtained with the
oil, especially in the presence of wind and wave action. The
use of sorbent materials has proven more desirable in terms
of the oil-to-water ratios of the recovered materials, but the
difficulties of containing and collecting sorbents once they
are dispersed upon the oil surface are considerable. The
oleophilic belt oil scrubber is intended to obtain the high
oil-to-water ratios of sorbents while eliminating the
problems of recovering vast quantities of material loosed
upon the water surface.
The oil scrubber utilizes a continuously cycled, endless,
buoyant, oleophilic belt to recover oil from the water's
surface. The belt is drawn over the water, across the area of
an oil slick, passed through a set of wringers to remove the
sorbed oil from the belt material, and returned to the
water. An idler pulley is generally employed to extend the
belt away from the wringing and driving machinery.
The oil scrubber concept is appealing due to its
simplicity, economy, and portability. Early investigations
indicated that, with a low power requirement, near total oil
recovery was possible, and that the device remained
effective in moderate currents and seas. Large oil volume
recovery rates appeared possible due to the high
oil-to-water ratios obtainable. Model tests in the
Netherlands2 were encouraging, as the models operated
smoothly and remained effective in the presence of flotsam.
During these investigations, polypropylene wool was chosen
for the inner belt material on the merit of its oleophilic
qualities, high porosity, permeability, buoyancy, durable
resilience, flexibility, and high strength.
A three-month, integrated program of mathematical
modeling and experimentation was undertaken at Shell Pipe
Line Corporation's Research and Development Laboratory
in Houston, Texas, under sponsorship of the U.S. Coast
Guard,*to obtain a working knowledge of the factors
influencing the oil scrubber's performance. The object of
*The opinions or assertions contained herein are the private ones of
the writer and are not to be construed as official 01 reflecting
the views of the Commandant or the Coast Guard at-laige.
309
-------
310 PHYSICAL REMOVAI
this investigation was to develop an understanding of the
basic phenomena involved in the system's operation,
sufficient to allow the prediction of the performance
characteristics of proposed oil recovery devices of this type.
The process of removing oil from water surfaces by
means of a continuous oleophilic belt consists of four basic
steps. These steps, and factors related to each, are:
0) The transport of oil on the water surface to the
proximity of the belt
a) Spreading of the slick due to gravitational and
surface tension forces.
b) Influence of wind, current, waves, and belt
motion on movement of the slick.
c) Use of booms and surface active chemicals in
proximity to the belt.
d) Lateral movement of the recovery belt.
(2) The transfer of oil from the water surface to the belt
surface and interior.
a) Imbibition of oil by the belt while in motion.
b) Withdrawal of fluids on the belt surface upon
removal of the belt from the water.
c) Mixing of oil and water by the belt and effects
due to the presence of emulsion or sludge.
d) The presence of detergent chemicals in the
water and oil.
(3) The transport of oil by the belt to the wringer
a) Influence of the relative motion of the water on
the oil holding ability of the belt.
b) Draining of oil through the interior and from
the surface of the belt when it is lifted from the
water.
(4) The wringing operation
a) Pressures created within the belt by rollers or
other wringing devices.
b) Traction forces of the wringers on the belt (if
drive is supplied through the wringer-rollers, as
has been the case to date).
c) Deterioration of belt properties with use.
The maximum flow rate obtainable with a given system will
be determined by the minimum of the set of maximum
flow rates permitted by each of the above steps for that
system.
QMAX3'4
Thus, if the QIM AY mav ^e determined for each of these
steps, the overall performance of the system may be
predicted.
Oil Absorption by the Belt
Fundamental to the operation of the oleophilic belt oil
scrubber, is the absorption of oil by the belt while it is
floating on the water. To demonstrate the influence of
various fluid and belt material properties on the imbibition
rates, the driving force of the flow in a single capillary may
first be considered. The condition of equilibrium for point
P in Figure la is
°a,o cos a = (CTa,s - ao,s)
0)
.o^s ar>d °o,s are tne interfacial tensions of
air-oil, air-solid, and oil-solid respectively. Thus
a = cos"
a,o
The driving force for the single capillary is then
F = 27170,, n cos a =
(2)
(3)
Here A0a 0 = (oa,s"°o,s)> or tne driving force per unit
circumference of the interfacial tensions.
For the absorption of oil by a section of porous
material, as illustrated in Figure Ib. the driving force of the
flow becomes the sum of the driving forces of the
interfacial tensions in each of the pores over the
cross-section area A of the material.
F = 2 F; = Aoa n 2?r2 r; (4)
A A '
The effective driving pressure may then be found by
dividing by the fluid area,
AP = Aa
2
A
Aa.
(5)
where L is the specific surface, or pore surface area per unit
A I R
Figure la - Driving Force in a Capillary
-------
OLEOPHILIC BELT OIL SCRUBBER 311
Porous Medium
Figure Ib - Absorption of Oil by a Porous Oleophilic Material
volume of the material. When the driving pressure is
expressed in this form, the cross-section of the pores need
not be assumed circular.
Equation (5) makes no allowance for the non-parallel
walls of the capillaries. The variation in the angle between
the pore walls and the normal to the interfacial plane must
be accounted for by replacing £ by 2e, the effective
specific surface of the material. For all materials.
Se < 2 (6)
Equations (5) and (6) may be used together with
Darcy's Law in the form3
K =
Q
A(AP/L)
(7)
where Q is the volume flow rate, ju is the fluid viscosity, A
is the cross-section area, AP is the pressure drop over the
length L, and K is the permeability of the material, to
determine the rate at which fluid is drawn into the material.
The volume flow rate per unit area is then
ACT
a,o
(8)
Noting that the rate of propagation of the fluid boundary is
dL =5/0 (9)
dt
where 0 is the porosity of the material, the rate at which
the fluid boundary progresses into the medium may be
determined from the relation
Ao
a,o
(10)
Thus
ACT
L =
a,o
(ID
and the volume of oil absorbed per unit area, as a function
of time, is
ACT
q =
a,o
2K2
(12)
In general, a dry belt will absorb water much more
rapidly than oil due to the water's higher driving force and
lower viscosity. Thus, when the slick depth is less than the
belt thickness (do/b
-------
312 PHYSICAL REMOVAL. . .
Jw,o
X
/
(15)
with Aaw 0 = (aw,s - ao,s)- If only one edge of the belt is
exposed to oil, the relation becomes
RI -
(16)
It should be noted that in developing equation (15)
and (16), the effect of the viscosity of the water within the
belt was intrinsically ignored. The resulting error was
examined analytically and found to be 5% or less for Rj
> '\5, and to improve with increasing HQ and R.
Experimental Apparatus and Procedures
The "oil scrubber" used in the experimental portion of
this program is shown in Figures 3a and 3b. The wringer
and drive assembly weighed 725 pounds, and was powered
by a 3 hp electric motor. The wringer consisted of two
6-inch diameter steel rollers, which were adjusted to a gap
of 0.2-inch during the experiments. The belt was
Figure 3a - Front View of Oil Scrubber
approximately three inches wide by 5/8-inch thick, and
was composed of polypropylene felt with a 6.36 x 1O4
inch mean fiber diameter, enclosed in a nylon mesh sewn
with three seams, as illustrated in Figures 4a and 4b. The
belt was run through the wringers for 250 cycles prior to
the oil recovery experiments to eliminate the effects of belt
compression on the experimental data. A pully was utilized
to keep the 89 foot belt extended across a 125x50x6 foot
Figure 3b - Rear View of Oil Scrubber
wave tank during quiescent water and wave state testing.
Floating booms were used to confine the oil in proximity
to the belt. For testing the effect of currents normal to the
belt length, a section of belt was extended across the 6x6
foot test section of a current tank, in which current
velocities of up to 8 feet/sec could be produced. Tests were
also conducted with the current running parallel to the belt.
Refined oils, whose properties are shown in Table 1, were
used for testing as the properties of refined products vary
less upon weathering than those of crude oils. Oil properties
were tested periodically during the experiments so that any
weathering effects could be taken into account in
processing the data.
Slick depth measurements were taken before and after
each run. Oil-water ratios were determined from periodic
samples of the effluent. Flow rates were derived from the
time required to fill standard containers. Visual
observations of the behavior of the belt and machinery
were made during each run.
Table 1
Test Oil Properties
Type
Specific
Gravity at
70dF
LVI 65 Naph- 0.8935
thenic
Golden Paiaf- 0.8870
ShelOOWfinic
Kinematic
Viscositv at
70°F
centistokes
27
210
Intertidal
Surface Tension
Tension (Tap Water)
dyne/cm dyne/cm
30.1
30.0
41.0
24.5
-------
OLEOPHILIC BELT OIL SCRUBBER 313
Figure 4a - Oleophilic Belt Before Testing
Results
Equation (16) is shown as a solid line in Figures 5, 6,
and 7, together with data obtained in the experimental
program, vvjiicjj has been non-dimensionalized in terms of
R! 7, and Q. Q is a non-dimensional volume recovery rate,
defined as
Q =
wh V
(17)
B
where Q is the volume flow rate and Vg is the belt velocity.
The dimensionless soaking time was found from the belt
velocity and length of belt on the water bv the relation
L
I
\
A°
w.o
\ JjL
/ VB
(18)
R! was used for purposes of comparison with the data,
after it was observed that the small area between the
outgoing and incoming belt was relatively free of oil during
the scrubber's operation, and absorption took place
primarily at one edge of the belt (the outside).
In Figures 5. 6, and 7, R is plotted against?for various
ranges of (d0/b). Broken lines have been included in these
figures to indicate the general trends associated with
varying slick depth ratios. It should be noted that these
values were not corrected for the effects of wave height to
length ratio, drift velocity, or the wind conditions under
which the data were taken. Data taken in quiescent
conditions (h/6 = 0) areindicatedby the darkened symbols.
It is evident from Figure 7. that equation (16) gives a
Figure 4b - Oleophilic Belt at Conclusion of Test Program
oo
00 O2 04 O6 08 I O 12 14
t
Fieure 5 - R as a Function of Dimensionless Soaking Time (?) for
Ranges of d0,b from Experiments with LVI 65 Oil. Broken Lines
Indicate Trends.: Solid Symbols Indicate Quiescent Conditions (h/£
= 0).
generally conservative estimate o^the recovery rates for ?>
1 and (d0/b) 0.6. Values of Q observed for (do/b)<0.6
are less than theoretically predicted as the assumption that
-------
314 PHYSICAL REMOVAL. . .
the entire depth of the belt edge is exposed to the oil
becomes increasingly invalid and the influence of end
effects on the flow becomes significant.
i.or
0.9 -
O.I
00
d./b<0.7 O-
0.7
-------
OLEOPHILIC BELT OIL SCRUBBER 315
slick depth to belt thickness ratio of 0.63. Similar data for
quiescent conditions are included for comparison. In each
case, the total and oil volume recovery rates are increased
by wave action. Further, the oil volume recovery rate is
increased to a greater extent than the total volume recovery
rate, resulting in an improved oil recovery ratio as
i.o
0.9
o.e
0.7
0.6
R 0.5
0.4
0.3
0.2
O.I
tested at wave steepness ratios less than 0.026. The smallest
ratio tested was 0.027.
0.0
O.l
-------
316 PHYSICAL REMOVAL. . .
length. Oil recovery ratios increased with slick depth as
before, however, ratios ceased to increase at shallower slick
depths than without current. This was apparently due to
the increased tendency of the oil to contact the underside
of the belt at shallower slick depths due to the effects of
the current. At high current velocities normal to the belt
length (2 ft/sec and greater), a significant decrease in oil
recovery rate was observed. This was attributed to belt
instabilities, as the belt was turned on edge or drawn
beneath the surface by the flow.
During the tests, it was observed that recovery rates
were not significantly affected by the "rag" and "scum"
produced by the weathering of oil. Emulsions were
produced by the wringing operation but presented no
particular problem as they would break spontaneously
when allowed to stand for approximately half an hour.
CE
i I0
0
o
S. 0.8
TJ
3
2 0.6\
£
o —
•o
I 0.4
o ,
u
9
tL
5 0.2
•5
o
K 0.0
0
Approximate Average
in Calm Water
/Approximate Average
/ With Waves
M I
D
A
A
OIL T d./b
A SHELL GOLDEN 0.17 0.65
A LVI OIL 0.17 0.66
• SHELL GOLDEN 0.17 1.20
E LVI OIL 0.17 1.20
1 1 1 1 1
00 0.02 0.04 0.06 0.08 0.10
Wave Height to Length Ratio (ti/Z)
Figure 12 - Oil Recovery Rate Divided by Total Recovery Rate as a
Function of Wave Height to Length Ratio
Performance of Larger Devices
The dimensionless soaking time (t) and slick depth to
belt thickness ratio (do/b) provide an adequate basis for the
scaling of oil volume ratios and total volume recovery rates
for various oils, belt cross-section geometries, and belt
velocities and sizes. As an example, the performance of a
device utilizing a larger belt, of width 20 inches and
thickness 0.8 inch, is considered in Table 2. Such a belt, if
constructed in the same manner and of the same material as
that of the experimental device, would weigh
approximately 0.95 pounds/foot dry and 6.06 pounds/foot
wet. A belt length of 800 ft and a recovery ratio of R = 0.6
were assumed in constructing this table. It should be noted
that, in scaling the results, the intrinsic assumption was
made that the prototype wringer-drive configuration was
also similar to that of the experimental device.
From the table, it is evident that very low volume
recovery ratios are realized for the case of slicks of 0.25
inch depth; but, for deep slicks of the less viscous (18
centipoise) oil, a recovery rate of 165 bbl/hr is possible,In
view of the results obtained in tests with currents and
waves, it would appear that the recovery rate for thin slicks
might be increased by the presence of waves and/or
currents. A further increase might be achieved by
decreasing the gap between the rollers; however, this might
result in a gradual reduction in porosity and a general
deterioration of the belt with a consequent reduction in the
oil capacity of the belt over a period of time.
Analyses of the rate of transport of oil to the belt on
the water surface, taking into consideration the effects of
wind, current, and the spreading of a slick, were
performed.6 For times in excess of 50 hours after a 15,000
bbl spill, fluxes greater than those corresponding to the
maximum recovery rates indicated in Table 2 may be
achieved by very slow lateral motion of the belt (less than
one mph).
CONCLUSIONS
These analyses and experiments have demonstrated
that the rate of absorption of oil by an oleophilic belt
increases with increasing specific surface and permeability
of the belt material, increasing slick depth, decreasing oil
viscosity, and decreasing interfacial tension between the oil
and belt material. In operations with high viscosity oils and
high belt speeds, significant quantities of oil may be
withdrawn as a film on the belt's outer surface. In general,
the oil scrubber's performance is not detrimentally affected
Table 2
Predicted Characteristic Values for Prototype Oil
Scrubber with Polypropylene Wool Belt
20 Inches Wide, 0.8 Inches Thick, and 800 Feet
Long, Operated at an Oil Recovery Ratio (R) of 0.60
Oil
•>
VO
§
4> —
•O a>
3«
Slick
Depth
in
0.25
0.50
1.00
0.25
0.50
1.00
d0/b
0.31
0.62
1.25
0.31
9.62
1.25
A
3.20
0.20
0.02
0.03
0.02
0.008
T
Or
0.35
033
032
0.17
0.18
0.19
f
Qo
0.28
0.26
0.26
0.14
0.14
0.15
(sec)
14,150
884
88
1,489
1,048
441
VB
(ft/sec)
0.056
0.90
9.05
0.537
0.764
1.814
Qo
(gpm)
0.8
12
115
3.6
5.5
14
Qo
(bbl/hr)
1
17
165
5
8
20
-------
OLEOPHILIC BELT OIL SCRUBBER 317
by the presence of waves; nor by the presence of solid
materials, emulsions, or "rag" in limited quantities.
However, the oil scrubber's performance may be
substantially reduced by the presence of detergents and
other chemicals in the oil or water which reduce the surface
tension driving forces and thus oil imbibition rates of the
belt. The stability of the oleophilic belt is a primary
concern when it is to be operated in the presence of
transverse currents. In general, the maximum oil recovery
rate of a given system is limited by the rate at which oil
may be transferred to the belt surface and interior.
t = Time
T = Dimensionless time: t =
2Aa
Vg = Belt velocity
w = Width of belt
« = Contact angle
ju = Absolute viscosity
2 = Specific surface
a = Interfacial tension
Aa = Driving force per unit circumference
= Porosity
NOMENCLATURE
A = Area
b = Thickness of belt
do = Thickness of oil slick
h = Wave height
K = Permeability
L = Length
LB = Length of belt in water
2 = Wave length
P = Pressure
P = Effective driving pressure due to capillary
Q
forces
= Volume flow rate
= Dimensionless. volume recovery
~ Q
rate: Q=
q = Volume absorbed per unit area
q = Volume flux per unit area
R = Volume recovery ratio, oil volume to total
volume
R! = Volume recovery ratio, oil volume to total
volume, one belt edge exposed (Eq. 16)
R2 = Volume recovery ratio, oil volume to total
volume, both belt edges exposed (Eq. 14)
r = Radius of capillary or pore
Subscripts
a = Air
B = Belt
e = Effective
o = Oil
s = = Solid
T = Total
w = Water
REFERENCES
1. W.F. Searle, Jr., "Two Oil Spill Control Systems Tailored
to Specific Tasks", Ocean Industry, Vol. 5, No. 7, July
1970,p.45.
2. H. Tadema, "New Methods of Combatting Oil Slicks",
API-FWPCA Joint Conference on Oil Spills, Proceedings,
New York City .December 15-17,1969.
3. R.E. Collins, Flow of Fluids Through Porous Materials,
Reinhold Publishing Corp., 1961.
4. D.A. White and J.A. Tallmadge, "Theory of Drag Out of
Liquids on Flat Plates", Chemical Engineering Science,
1965, Vol. 20, pp. 33-37.
5. A.J. Soroka and J.A. Tallmadge, "The Inertia! Theory
for Plate Withdrawal", Fundamental Research in Fluid
Mecahnics, Part I, American Institute of Chemical
Engineers, 62nd Annual Meeting, Nov. 1970.
6. R.A. Cochran, W.T. Jones, J.P. Oxenham, U.S.C.G. Rept.
No. 714103/A/002, "A Feasibility Study of the Use of the
Oleophilic Belt Scrubber", Shell Pipe Line Corp., Res. and
Dev. Laboratory, October 1970, Final Report.
-------
FREE VORTEX RECOVERY OF
FLOATING OIL
Eugene B. Nebeker and Sergio E. Rodriguez,
Scientific A ssociates, Inc.
Santa Monica, California
and
Paul G. Mikolaj
University of California
Santa Barbara, California
ABSTRACT
A concept employing a free vortex for use in
recovering oil from high seas oil spills is presented. An
experimental evaluation program has been completed which
demonstrates the feasibility of this concept as well as design
limitations.
An oil slick will migrate toward the center of the
vortex due to the action of the water flow induced by an
impeller. At an appropriate speed of rotation, the oil will
submerge and accumulate within a central region of the
vortex. This pocket will contain a concentrated mass of oil
which can readily be removed by conventional pumping.
Advantages of this technique include effective operation in
high seas and the ability to both collect and concentrate an
oil slick in a single operation.
Tests were performed with a free vortex oil recovery
model having an impeller diameter of one foot.
Performance data were obtained both under quiescent
water conditions and also under environmental conditions
that simulated 10-foot deep water waves, 20-knot winds,
and 2-knot currents.
Detailed scaling considerations based on the test data
indicate that a prototype device, with diameter on the
order of4-feet and larger, would be operable in all typically
occurring 10-foot seas. Depending on its size, the prototype
will recover in excess of 100 gallons per minute of oil with
an oil-to-water ratio greater than 1.2 when operating with a
crude oil film of only 0.1 inches in thickness.
INTRODUCTION
Procedures for dealing with an oil spill in the marine
environment may conveniently be classified into two phases
— containment and recovery. 1 Containment, usually by
means of floating barriers or booms, is necessary to prevent
the oil from spreading into a thin slick which can cover vast
areas of the water. Since practical considerations are such
that not all of the spilled oil is likely to be contained, the
recovery device should be capable of removing both thin
slicks (5*0.001 inches) as well as the thicker slicks ( > 0.1
inches). Hence, the technical effort on oil spill clean-up has
been directed both at the development of techniques for
thin oil film recovery and of containment systems which
provide for rapid deployment. In both aspects of spill
clean-up, a primary problem is obtaining adequate
performance under ambient disturbance, i.e., waves,
currents, and winds. Most recovery devices and
containment booms become ineffective in waves more than
2 feet high.2
The methods presently used for dealing with a floating
oil film include direct mechanical recovery or skimming,
recovery with the aid of a floating sorbent material, and
special techniques such as sinking, burning, and dispersion.
Of these, the mechanical skimmers offer a number of
attractive advantages. Sorbent materials require
broadcasting and admixing with oil, and also pose difficult
recovery problems. The other combatant techniques often
involve adverse secondary effects to the marine
environment. Many mechanical skimmers utilize submerged
weirs of various types to pick off an oil-rich surface layer of
the water. Another approach involves physical contact of
the oil layer with an oleophilic rotating drum, endless belt,
disk, or similar arrangement.
This paper presents preliminary work on the relatively
novel concept of mechanical skimming by means of a free
vortex which is generated at the water's surface. This
approach has a fundamental advantage in that oil collection
is not directly performed by the hardware but rather by the
319
-------
320 PHYSICAL REMOVAL
induced vortex flow which is better able to maintain its
relationship to the water surface than the hardware itself.
In addition, the vortex flow represents a substantial
concentration of angular momentum which resists
distortion by ambient disturbances. Hence, the free vortex
skimmer concept offers a special capability for oil slick
recovery under both quiescent and disturbed water
conditions.
FREE VORTEX CONCEPT
The free vortex collection process is shown
schematically in Figure 1. A rotating submerged impeller
assembly produces vortex flow in a subsurface column of
water. The axial flow of water through the impeller
produces an inward funneling flow in the overlying water.
Under the action of these flow fields, an oil slick will
migrate toward the vortex axis, submerge, and concentrate
in a central pocket. A recovery pump intake within this
pocket can thus remove oil with relatively little water. A
practical free vortex skimmer involves a relatively complex
flow field, particularly with regard to the detailed behavior
of oil entrained by the vortex and to the hardware needed
to maintain a strong vortex flow. The following comments
indicate in a qualitative way, some of the important
considerations in vortex skimmer performance.
In the rotating water column, both a vertical
hydrostatic pressure gradient, and a radial pressure gradient
are present; the latter in association with centrifugal
acceleration. The simultaneous existence of these pressure
gradients under a constant-pressure free surface leads to the
well-know depression of the surface over the vortex.
Submerged oil will experience a buoyant force and a radial
force toward the vortex axis. For the devices considered
here, the radial forces are preponderant in the outer vortex
region. For example, with 100 rpm water rotation at one
foot radius, the centrifugal force is three times larger than
the bouyqnt force. Near the vortex axis, these forces
become comparable and the buoyant force eventually
dominates. Thus, the oil pocket forms at the top and center
of the vortex column.
Inward migration of oil floating at tne water surface
results from the converging radial water inflow produced by
axial flow through the impeller. Surface oil simply rides
with this inflow towards the vortex center. The rotational
flow at the surface is not effective in collecting oil because
its net radial force on floating oil is zero. Once in the
vicinity of the vortex axis, however, two new factors come
into play which tend to submerge the oil. One is a
downturning or funneling of the radial water inflow
toward the impeller. The other is turbulent diffusional
transport; a large scale vortex flow of this type contains
considerable irregular eddying motion which tends to build
up and maintain a concentration of submerged oil droplets.
Once oil has been submerged, the centrifugal forces
produced by the rotational flow field cause the oil droplets
to acquire an inward slip velocity relative to the rotating
water. A similar but upward slip velocity is established by
the buoyant forces. The axial flow field then tends to take
droplets downward beyond the collection pocket and
PUNP
-—*». RECOVERED OIL
SUBMERGED
PROPELLER
Figure 1: Sketch Showing the "Free Vortex Recovery of Floating
Oil." Due to the action of water flow induced by the submerged
propeller, a surface oil slick will migrate toward the center of the
swirling column of water. The oil then becomes trapped by the
vortex'seentrifugal force field and accumulates in a pocket below the
water surface where it can be removed by pumping.
turbulent diffusion tends to distribute droplets throughout
the entire vortex region.
Therefore, the free vortex skimmer operates by means
of a dynamic balance between the inward and upward
forces which tend to form the vortex pocket and the flows
which tend to submerge and distribute the oil. Because of
these factors, the pocket is not uniquely defined but
represents a region of high oil concentration which declines
downwards and outward. However, both theoretical
estimates and experimental observations indicate that the
concentration profile can be made sufficiently sharp to
regard it approximately as the formation of a central,
oil-rich pocket.
An underwater photograph of a vortex pocket
obtained when the axial and rotational flow fields are
properly balanced is shown in Figure 3a. In contrast, Figure
3b shows the "bathtub" type of vortex formed when axial
flow predominates. This latter mode of operation is
unsuitable for skimming operations because oil will be
pulled beneath the pocket and into the impeller. Since the
major and inherent advantage of the free vortex device is its
ability to concentrate and accumulate oil in a pocket, the
axial flow must be suitably balanced by an induced
rotational flow.
-------
FREE VORTEX RECOVERY
321
The potential recovery efficiency is related to the
volume fraction of oil in the pocket and will depend on
those factors which determine slip velocity. Among these.
the oil density is of paramount importance. Recovery
efficiency will depend on the density contrast between oil
and water and will tend to decline as the oil density-
approaches that of water. Viscosity does not appear to be an
important factor since the viscosity of oil is ordinarily
sufficiently large that viscosity-dependent internal
circulation in oil drops should not affect slip flow
significantly. Oil droplet formation would thus be expected
to result primarily from dynamic forces in the turbulent
flow field rather than from viscous stresses. As indicated
by the Weber number, the oil/water interfacial tension will
be influential in the process of oil breakup and drop
formation. However, oils will not vary widely in this
property and a major quantitative effect is not to be
expected.
Figure 2: Photograph of Model in Final Configuration
Figures 3a - 3c: Photographs of various types of vortices.
EXPERIMENTAL INVESTIGATION
A concept feasibility study of the free vortex to
recover oil from high seas oil spills was performed in the
summer of 1970^. Following a series of laboratory
experiments to establish the magnitude of key operating
parameters, a free vortex oil recovery model was designed
and constructed. The model tested is shown in Figure 2 and
consisted of a 1-foot diameter impeller surrounded by a
rotating cylindrical duct with an annular disc. The impeller
was powered by a hydraulic motor which was connected to
high pressure lines supplied from a tender. The entire
impeller assemblage, which was mounted on the center of a
triangular frame, was suspended beneath the water surface
from three floats. The overall size of the model, as shown in
Figure 2, can be judged by noting that the center-to-center
distance between floats is approximately 41/2 feet.
Testing and data collection were performed in a model
basin capable of providing deep water waves. Data were
obtained both under quiescent water conditions and also
under environmental conditions that simulated 10-foot
seas, 20-knot winds, and 2-knot currents.
Throughout the experimental work, the major
performance criteria of interest were the effectiveness and
efficiency. Effectiveness is the rate of oil recovery in gallons
-------
322 PHYSICAL REMOVAL
of oil per minute and efficiency is the volume fraction of
oil in the recovered oil/water mixture. Throughout this
program, only clear oil was recovered, and no water-in-oil
emulsions were detected.
Testing Under Quiescent Conditions
Testing was first initiated to determine the effect of oil
film thickness on performance under quiescent conditions.
During these tests, the model was surrounded by a 10-foot
diameter circular boom. Various quantities of crude oil
were added to the water surface within this boom to form
oil film thicknesses ranging from 0.001 inch to 0.1 inch.
The physical properties of the crude oil used in these
experiments are shown in Table 1.
After sufficient time was allowed for the oil to form a
uniform layer, rotation of the impeller was started.
Approximately 1-2 second were required to bring the
impeller up to operational speed. After this full rotational
speed was attained, 3-5 seconds were required to develop a
vortex and start the inflow of the slick to the center of the
device. From 10 to 15 seconds more were necessary to
draw in enough oil to form an oil pocket. Beyond these
times, insufficient oil remained within the capture radius to
supply the pocket, and the vortex became "oil starved."
This phenomenon is shown by the sequence of photographs
in Figure 4. The oil slick in this particular run was residual
crude, 0.032 inches thick. Behavior for other oils and
thicknesses was similar. A significant feature of these
photographs is that a capture radius of approximately 1 2/3
feet is almost completely cleared of oil in 20 seconds after
startup.
In taking data, the transfer pump used to remove oil
from the pocket was started at the time the impeller
reached operational speed (t = 0 seconds). The discharge
from the pump was directed into a series of containers at
5-second intervals. Analysis of the contents of these
containers showed that maximum effectiveness and
efficiency were attained 20-30 seconds after full impeller
speed was reached. During this interval, sufficient time had
passed for the oil pocket to develop, but not enough for the
pocket to be starved for oil. These maximum
effectivenesses and efficiencies are reported because, not
suffering from the effects of vortex formation or oil
starvation, they are the most meaningful data.
Table 1: Summary of Oil Properties
Oil Type
CPI
Gravity
Specific
Gravity (60/60°F)
Kinematic
Viscosity (centistokes)
(«60°F @100°F
Heating oil
Diesel oil
Crude oil
Residual fuel
37C
32°
26°
19°
0.840
0.865
0.898
0.940
4.8
8.4
39
500
2.8
4.0
12.0
160
-------
FREE VORTEX RECOVERY.. . 323
Figures 4a - 4f: Surface Oil Slick Patterns During Quiescent Tests.
These data for effectiveness and efficiency as a
function of oil film thickness are shown in Figure 5. For
film thicknesses from 0.001 inch to 0.1 inch, the
effectiveness ranged from 0.1 to 6.6 gallons per minute, and
the efficiency varied from 0.9 to 55 percent using a total
pumping rate of 12 gallons per minute from the vortex. The
effectiveness and efficiency increased monotonically up to
the maximum film thickness tested. Performance did not
level off significantly within the range of film thicknesses
used, indicating that the maximum effectiveness and
efficiency of the free vortex model were not approached.
Conceivably, an efficiency approaching 100 percent could
be attained at slightly greater flim thicknesses.
These results are believed to be very conservative for a
variety of reasons. Subsequent tests indicated that
substantial changes in performance could be obtained by
varying the depth of submergence of the recovery pump
intake. In addition, only a nominal recovery pumping rate
of 12 gallons per minute was used. Increasing this pumping
rate would improve the effectiveness while lowering the
efficiency and vice versa.
Tests were also made to determine the effect of oil
properties on the efficiency and effectiveness. These
measurements were made at a nominal film thickness of
0.032 inch using the four oils listed in Table 1. Performance
with the heavy oil was only approximately 25 percent less
than that obtained with the light oils. This decrease in
performance is most likely attributable to an increase in
density rather than viscosity.
Testing Under Simulated High Sea Conditions
Final testing of the free vortex oil recovery model
under a variety of environmental conditions was performed
in a model basin 120 feet long by 48 feet wide.* At the
time of testing, the water depth was maintained at 13 feet.
For this depth, the maximum period of deep water waves
that could be simulated was 3 seconds'. The maximum
wave height used in the tests was approximately one foot.
The action of waves on the vortex was viewed both
from the surface and also from under water. With the
possible exception of a slight narrowing of the vortex at the
water surface, the shape and configuration of the vortex
under wave action was nearly the same as that under
quiescent conditions. However, the vortex moved in an
orbital pattern characteristic of the wave particle motions.
Figure 3c shows a photograph of a vortex being displaced
*The model basin used in these tests was operated by the Offshore
Technology Corporation in Escondido, California.
-------
324 PHYSICAL REMOVAL
slightly due to the action of a simple wave with a 5-inch
wave height and a 2-second period.
Following these qualitative observations, a series of
tests was run to establish the wave regime for which stable
vortex behavior could be expected. These tests were made
without using oil. Various simple (sinusoidal) waves were
generated and notation was made of the wave height and
wave period combinations which the vortex could not
withstand indefinitely. This information is shown on Figure
6 as the "critical line." Throughout the area above and to
the left of this critical line, the vortex was stable
indefinitely and thus represents the operable wave regime.
The area bounded by the critical line and the line
corresponding to unstable or breaking deep water waves^
represents the inoperable regime. Throughout this latter
area, simple waves eventually destroyed the vortex. The
point of eventual destruction of the vortex was readily
apparent by visual observation, and the data points shown
on this critical line were very reproducible. Tests were also
conducted to determine the stability limits of the vortex
under currents. Action of a current on the model was
simulated by towing. A line was attached from the model,
through a system of pulleys, to lead weights. The weights
pulled the model through the water at a constant speed
which was measured by means of a rotary variable
differential transformer attached to one of the pulleys. The
behavior of the vortex was observed visually and the
maximum towing speed which the vortex could maintain
without being destroyed was about 0.7 knots. The action of
the voitex to towing was similar to that under wave
conditions except that the orbital motion associated with
waves was not present.
To investigate the effect of waves on the oil recovery
performance of the model, diesel oil (see Table 1) was
added to the water surface at a constant rate. The point of
addition was about 11/2 feet upstream of the mechanical
axis of the model. A boom or other containment device was
not used in order to avoid adversely affecting the wave
characteristics. With the vortex formed and the recovery
pump running, oil would first be collected under quiescent
conditions for a known time interval. Waves would then be
generated and the collection process repeated. By
comparing the amount of oil in the collected effluents, the
degradation in performance could be determined.
Two sets of wave conditions were used to study the
effect of simulated high seas on oil recovery performance —
one involving a wave period scan and the other a wave
height scan. The location of these wave scans is shown in
Figure 6. Test results showed a gradual decrease in
performance as the critical line was approached. The
observation was made, however, that the vortex continued
to collect and contain oil regardless of its wave induced
displacement from the mechanical axis of rotation. Since
the recovery head was in a fixed position, the displaced
vortex could not be effectively followed (see Figure 3c).'
Therefore, the observed decrease in performance seemed to
be more a function of recovery head position than of the
vortex's ability to collect oil while in its displaced position.
.1
.08
.06
EFFECTIVENESS (GALLONS OF OIL/MINUTE)
1.0 2.0 3.0 4.0 5.0 5.0,
.0010
20 30 10
PERCENT EFFICIENCY
50
60
Figrre 5: Effect of Oil Film Thickness on efficiency and
Effectiveness
3.0
2.5
2.0
5
0.5
STABLE VORTEX
No. 3i-lJ /-/
Random
Sea
State
Region of
Simulated Whitecaps
.20 .40 .60 .80
WAVE HEIGHT (FEET)
Figure 6: Vortex Stability in Waves
1.00
-------
FREE VORTEX RECOVERY ... 325
Experiments were then performed to investigate the
model's behavior under simulated number 3 and number 5
random sea states, scaled to one-tenth^. The average period
and wave height of these simulated sea states are shown in
Figure 6, where the wave height is scaled to one-tenth and
the wave period to I/ 10.
Using the same procedure discussed above, the
effectiveness and efficiency were measured before and after
the arrival of waves. The qualitative observation was made
that random sea states did not affect vortex stability as
severely as a series of simple waves close to the critical line.
In random seas, the vortex usually has a chance to recover
after a potentially destructive wave passes before being hit
by another.
To investigate the effect of winds, a large blower was
suspended upstream of the model in such a way that the air
streamlines were almost parallel to the water surface. An
anemometer measured 20 knots at the model. With a fetch
of about 10 feet, a surface current of about 1 foot/second
was generated. To investigate the effect of whitecaps on the
operation of the model, the same experiment was repeated
in conjunction with steep waves near the breaking wave
line, (wave height) / (wave length) = H/L = 1/7, in Figure 6.
In this manner, steep waves were created and "blown over"
by the wind to form whitecaps. To perform this
experiment, the available range of waves was necessarily
limited to the region bounded approximately by the slender
rectangle at the bottom left corner of Figure 6. Other waves
near the breaking wave line would have been inside the
instability region of vortex operation. Using the
experimental procedures previously described, the
effectiveness and efficiency were decreased about 60
percent by the 20 knot wind and about 80 percent by the
wind produced whitecaps.
SCALING
Significant Variables
In scaling a free vortex oil recovery device to larger
physical sizes, the interaction of size with operating
parameters such as film thickness, oil properties,
environmental conditions, etc., must all be considered.
However, since the major objective of this investigation has
been to develop an oil recovery device for use under high
sea conditions, primary emphasis must be given to the
environmental parameters. The tests conducted with the
one-foot model indicated definite limits with regard to
stable vortex operation in waves and currents. Therefore, in
scaring these test results to larger devices, the main problem
was to determine the manner in which the limits of vortex
stability were physically related to the significant
environmental parameters.
In Figure 6, the region of stable vortex operation has
been presented on a wave height-period diagram. Wave
height is an independent variable and therefore may be
scaled directly against the vortex diameter on purely
dimensional considerations. However, selection of the wave
period rather than wavelength as the second variable is a
matter of choice. These quantities are related, and the
choice as to which one is the fundamental variable has a
large influence on scale up.
The wave period was selected as the significant variable
on the consideration that vortex stability is limited by the
speed of subsurface orbital water motion which is
proportional to the ratio of wave height to period. In the
model tests, vortex destruction (as shown by the critical
line of Figure 6) occurred at orbital speeds ranging from 0.5
to 0.7 knots. This speed corresponds approximately to the
towing speed which also resulted in vortex destruction.
Since wave action and towing are rather distinct processes,
this correspondence in speeds may be taken as experimental
evidence supporting the choice of wave period. Test
experience also indicated that neither the wavelength nor
the wave steepness, which is also nearly constant along the
stability limit in Figure 6, provides a satisfactory
explanation of vortex destruction.
Figure 7 shows vortex stability limits on a wave
height-period diagram for vortex diameters of 1,2,4, and 8
feet. These limits have been obtained from Figure 6 by
assuming that the curve of critical wave periods is a
function of (wave height) / (vortex diameter); the wave
height is thus expressed as a multiple of vortex diameters.
However, the period scale corresponding to the
experimental observations with the model has been
retained. On dimensional considerations, the wave period
must scale to rotational speed which is the only design
parameter involving pure time. Hence, retention of the
period scale implies that all vortex sizes in Figure 7 will
operate at the same rotational speed as the one-foot model.
As will be discussed in the following section, the model
tested was already near prototype size. Therefore,
prototype devices which are not much larger than the
model may be expected to be operable at rotational speeds
near those actually utilized.
The other environmental factors to be considered in
scale up are currents and wind action. Currents may be
viewed basically in terms of the relative motion of adjacent
water. The effect of such relative currents is exemplified by
towing the free vortex device through still water. In the
towing tests performed with the one-foot model, vortex
stability was retained up to a towing speed of 0.7 knots.
From the scaling arguments presented above, this limiting
relative current increases in proportion to prototype
diameter — again assuming that rotational speed remains
constant. Thus, for example, a 4-foot prototype size would
be stable up to about 2.8 knots relative current. No major
or special scale effects can be foreseen as a result of wind
action since its primary effect on performance is through
induced water motion. With the possible exception of
"white cap" generation, the effects of wind induced waves
and currents can be treated as previously described.
Prototype Size
The vortex stability curves in Figure 7 establish a
region of operabflity to the left and above the limiting
-------
326 PHYSICAL REMOVAL
curve, i.e., for smaller wave heights and longer periods.
Stable operation and oil recovery are expected for all waves
which lie within this region. Also plotted in Figure 7 is the
curve which defines the region of theoretically possible
deep water waves, i.e., waves whose ratio of height to
length is less than or equal to l/?5>6. As in the case of the
vortex stability curves, the region lies to the left and above
the curve. Where this possible wave region lies inside the
stability region of the vortex, successful operation would be
expected.
In attempting to establish an approximate prototype
size for use in high sea conditions, the demarcation given
above is extremely pessimistic with regard to vortex oil
recovery utilization. Although a maximum wave steepness
of one-seventh is well founded on analysis and has been
verified experimentally, actual waves occurring in the open
sea do not approach this steepness. Myers, et al.6 indicate
that real wave profiles never exceed a steepness of
one-tenth and are commonly less than one-twentieth. These
practical wave limit lines (H/L = 1/10 and H/L = 1/20) have
also been included in Figure 7 to better define the expected
conditions of operation.
Besides wave steepness, consideration must also be
given to the maximum expected wave heights. In this
regard, the vortex stability limits for the smaller prototype
sizes shown in Figure 7 cannot be accurately drawn to
higher wave heights because the experimental observations
on the model were necessarily limited as to wave height. It
appears, however, that the vortex stability limits tend to
parallel the wave stability limits at large periods and
heights. Kinsman? states that about 45 percent of the
ocean waves are less than 4 feet high and 80 percent are less
than 12 feet high. Thus a maximum wave height of 5-10
feet could be considered as a reasonable upper limit of
practical oil recovery operation.
Inspection of the plots shown in Figure 7 leads to the
following conclusions as to the expected operability of
various size vortex devices in waves. A vortex recovery
device of about 6-feet diameter (main impeller) should be
operable in all theoretically possible waves up to about 10
feet in height. A device of about 4-feet diameter would be
operable in the most severe actually occurring waves. This
operability is certainly indicated for waves up to 5 -feet high
and probably extends several feet beyond. A device of only
2-feet diameter should be operable in the more commonly
occurring waves up to 2 or 3 feet in height. However,
extension into the 5-10 feet wave height range of interest
may be questionable as it implies a rather long
extrapolation of the model data used for scaling.
In summary, a free vortex oil recovery device with an
impeller diameter on the order of 3 or 4 feet appears to be
a suitable prototype size. This would represent the
minimum size device, with attendant minimum power
requirements and maximum maneuverability, required to
cope with practical wave regimes. Since the test model
already had a 1-foot diameter, extension of the test
experience to the indicated prototype size appears
reasonable.
2 H 6
HAVE HEIGHT (FEET)
10
Figure 7: Stability of Prototype Devices to Wave Action
Prototype Performance
For any given set of oil slick parameters (film
thickness, type of oil, etc.), the rate of oil recovery is
expected to increase in proportion to the square of the
linear dimension of the prototype. A larger prototype size
generally implies a greater amount of oil within the
immediate capture radius of the vortex. The capture area
would increase with the square of the diameter, and for a
given film thickness, so would the gross amount of oil
immediately accessible to the vortex. Thus, a 4-foot
prototype would encompass 16 times as much oil as the
1-foot model. Although the distance to be traveled by the
oil increases in proportion to diameter, so do the
transporting velocities. Hence, the potential effectiveness of
a 4-foot prototype is also 16 times larger than that of the
model.
The pumping rate used during model testing was 12
gallons per minute, a nominal choice with no effort at
optimization. With this pumping rate, a peak effectiveness
of 6.6 gallons per minute of oil was achieved with an 0.1
inch film of crude oil. This rate is considered very
conservative, for the reasons already mentioned. However,
by scaling this nominal pumping rate and very conservative
measurement of the effectiveness, a 4-foot diameter
prototype device would have an effectiveness'of 106 gallons
of oil per minute at the stated oil film conditions.
The effect of film thickness on the rate of oil recovery
is anticipated to be the same as that observed during model
testing. Effectiveness increased with film thickness because
thicker films provided proportionately more oil within the
capture radius of the vortex. However, as heavier oils are
encountered, effectiveness would be expected to degrade in
the same manner as found in testing the 1-foot model.
The expected efficiency of a prototype device is
related primarily to the nature and stability of the vortex
oil pocket. In this regard, film thickness and oil properties
would play the same role in a prototype as they did in the
-------
FREE VORTEX RECOVERY... 327
1-foot model. Similarly, a prototype would have the same
relative stability in waves as the model despite an increased
absolute scale of ambient disturbances. In contrast to
effectiveness, which is an absolute measure, efficiency is a
dimensionless criterion. Thus no gross size effects are
involved and the efficiencies observed with the 1-foot
model may be taken over to a prototype without change.
CONCLUSIONS
The following conclusions were reached from tests
performed with the 1-foot diameter experimental model of
a free vortex oil recovery device:
1. The free vortex ofl recovery concept has definitely
attractive performance charactertistics. For example, the
vortex flow field developed with the 1-foot size was capable
of removing 6.6 gallons per minute of oil from a 0.1-inch
film of crude oil. This effectiveness was achieved at a
12-gallon per minute gross pumping rate, giving an oil
recovery efficiency of 55 percent. Neither the pumping rate
nor the oil intake position were optimal choices. A
comparable performance, within 25 percent, was obtained
with various other oils. Decreasing film thickness reduced
these performance levels in a reasonable padual manner.
2. The vortex flow field showed reasonable stability against
external flow disturbances. Stability against wave motion
was a function of wave height and period for the 1-foot
model. In tests with wave heights up to nearly 1-foot, the
model retained stability over roughly half of the
theoretically possible wave spectrum. The model retained
vortex stability at towing speeds up to 0.7 knots.
3. Prototype devices with diameters on the order of 4 feet
and larger should make the vortex collection concept
feasible with all waves up to IWeet high. This estimate is
based on the reported actual limits of wave height and
period under open sea conditions. These prototype sizes
would be capable of withstanding relative currents or
towing speeds in excess of 2 knots. Prototype effectiveness
would increase in proportion to the square of the diameter,
e.g., a 4-foot device would have oil removal capacity on the
order of 100 gallons per minute for a 0.1-inch thick oil
slick. Efficiency for the prototype sizes would be similar to
those for the model. Since the 1-foot model was already
near prototype dimensions, this extrapolation of
performance appears reasonably safe.
ACKNOWLEDGEMENT
A substantial portion of this study was performed for
the U.S. Coast Guard under Contract DOT-CG-00594-A.
Assisting in the study were A. A. Allen, G. A. Griffith, and
R. L. Rundle.
REFERENCES
1. W. E. Lehr, Jr., "Oil Spill Containment and Clean-Up
Procedures," paper given at the Santa Barbara Oil
Symposium, Santa Barbara, California, December 18,
1970.
2. "Systems Study of Oil Spill Cleanup Procedures, Vol. I.,
Analysis of Oil Spills and Control Materials," Applied
Oceanography Division, Dillingham Corporation, La
Jolla, California, February 1970.
3. J. O. Hinze, "Fundamentals of the Hydrodynamic
Mechanism Splitting in Dispersion Processes," A.I.Ch.E.
Journal, 1,289(2955).
4. P. G. Mikolaj, E. B. Nebeker, and S. E. Rodriguez, "Free
Vortex Recovery of Floating Oil," Report No.
714103/A/003 prepared by Scientific Associates, Inc.
for U. S. Coast Guard Contract DOT-CG-00594-A.
5. R. L. Wiegel, "Oceanographical Engineering,"
Prentice-Hall, Inc., Englewood Cliffs, N.J., 1964.
6. J. J. Myers, C. H. Holm, and R. F. McAllister,
"Handbook of Ocean and Underwater Engineering,"
McGraw-Hill Book Company, New York, 1964.
7. Kinsman, B., "Wind Waves, Their Generation and
Propagation on the Ocean Surface," Prentice-Hall, Inc.,
Englewood Cliffs, N.J., 1965.
-------
CONCEPT DEVELOPMENT OF A POWERED
ROTATING DISK OIL RECOVERY SYSTEM
S. T. Uyeda, R. L. Chuan, A. C. Connolly, and
Philip O. Johnson
Atlantic Research Systems Division
Costa Mesa, California
INTRODUCTION
A simple technique for the recovery of oil from the
water surface is by the use of rotating disks which are pre-
ferentially wet by the oil and collected from the disks with
wipers. The principal is also utilized with rotating devices.
The potential advantages of the rotating disk technique
are:
(1) high recovery rate,
(2) recovery of thin oil slicks,
(3) recovery of oil with varying viscosities and
emulsification,
(4) relative insensitivity to waves and current,
(5) minimum tendency to emulsify the oil,
(6) relatively insensitive to debris,
(7) oil-water sepration during pickup
Because of these potential benefits, Atlantic Research
Corporation under the sponsorship of the Environmental
Protection Administration, Water Quality Office, per-
formed a series of studies to determine the feasibility of the
disk system for the recovery of oil from the ocean surface.
The evaluation program consisted of:
(1) Experimental tests in the tow tank in current and
waves for oil types ranging from light diesel to Bun-
ker "C" oil.
(2) Data comparison between theoretical analysis and ex-
perimental data and the derivation of
non-dimensional scaling coefficients.
(3) Preliminary sizing recommendation for a disk unit for
the recovery of 50,000 gallons of oil per hour.
The tow basin tests were conducted with aluminum
disks. Aluminum was chosen over teflon, polypropylene,
polyethelene, and neoprene after extensive laboratory tests.
The tests indicated that aluminum and polyethelene had
the best overall pickup efficiency in the viscosity range of
diesel to Bunker "C" oils. The manufacturability, and re-
pairability led to the choice of aluminum over polyethe-
lene.
The rotating disk system was found to be capable of
high oil pickup with little or no water pickup. The results
of the theoretical analysis compared satisfactorily with
experiments conducted at model scales.
- A summary of the theoretical development and com-
parison with experimental data is presented. The recom-
mended design for a 50,000 gallon/hour capacity system
and several concepts for utilization with booms and barriers
are illustrated.
Figure 1: Disk Oil Recovery Configuration
329
-------
330 PHYSICAL REMOVAL . .
Theoretical Development
Consider a disk of radius R immersed partially to a
depth of D and a corresponding chord C, in an oil slick of
thickness d floating on water, as depicted in Figure 1. The
disk rotates at the rate GO. The oil pickup mechanism may
be depicted as shown in Figure 2. In this vertical section of
the disk is shown the oil boundary-layer of thickness 6,
being pulled from the oil pool of thickness d up the disk at
a vertical velocity of cox, where x is the horizontal distance
from the center of the disk to the point in question, as seen
in Figure 2.
By equating the gravitational force and the shearing
force in an element of oil, the following equation for the
velocity distribution in the oil boundary-layer is obtained:
Pg 2 y / Pg
— y +— lv -ox
2/* 8 \ 8 $1
(1)
in which p is the density of the oil, and /u its viscosity
coefficient. The constants 6 and V5 in Equation (1) are
determined from boundary conditions at the "fillet" be-
tween the horizontal oil slick and the vertical oil bound-
ary-layer.
By considering the balance of the shearing force and
the surface tension, as sketched in Figure 3, in which FM is
the viscous force, ydx the surface tension force and h6 is
the height of the fillet, the boundary-layer thickness is
determined to be:
fy 27-7 \ fy~
•A/— + I^X-V J-tfc
VP& PS \ s/ VPS
which may be put into dimensionless form
where
(2)
2Q
v = —
S Cd
x+v
8 6?
(4)
by use of Equation (1).
The total rate of pumping for both sides of the disk
along the chord from xg to C/2 is then:
.C/2
/dQ\ / » (5)
I — I dx =
I
I
V
' K& S lj
&>x + v —— o Idx
With a change of variables
£ = — (ox- v )
y s
(6)
Equation (5) becomes dimensionless in the new variable
in which the upper limit of integration
C
(7)
' max
4M / C A
= I o> — — v I
y V 2 s)
and
It is noted that in the above expressions = o when cox
= vg. In other words, oil boundary-layer is not formed
along the entire chord from x = o to x = C/2. There is a
minimum xg = vg/co at which the boundary4ayer begins to
form.
The velocity at the edge of the boundary-layer, vg, is
determined by considering continuity of the average flow
of oij in the dick horizontally toward the disk and the
vertical flow in the boundary-layer.
8 =
Integration of Equation (6) yields
-------
ROTATING DISK RECOVERY SYSTEM 331
(8)
3 ( y 8
3/2 3
max
:t-
+
3/2
max
max
-4) + 5/r + 4
max ^ max
Equations (7) and (3) are combined to
max
Y
2(i
Equations (7), (8), and (9) can be combined to yield two
parametric equations in £ max for to and Q:
-f +—
2 max 10
5 f + 4 + ( f - 4) ( f + 1
" max •> max "" max
(10)
3 2
D
3/2
"" max
(11)
- max \
~ )
^C I
Disk
DISK
— — £ — — ----- L
1
x
OIL
Figure 3: Boundary Conditions
In Figure 4 the dimensionless pumping rate Q is
plotted against the dimensionless rotation rate w for var-
ious values of the dimensionless oil slick thickness d
As far as the above theory is concerned there is no
limit to the value of Q as co is increased, which would
suggest that very high pumping rates can be achieved simply
by turning the disk at a high rate. In practice this cannot be
achieved, because the disk becomes "starved" when the oil
in-flow rate toward the disk (which is supported mainly by
surface-tension controlled spread of the slick) cannot match
the removal rate of the disk. It is found experimentally that
when starvation occurs the disk picks up water as well as
oil, with the water content increasing as the disk rotation
rate increases beyond the limit at which starvation begins.
Figure 5 shows the comparison between theory and
experiment, the latter performed with a single 18-inch
diameter disk immersed in a stationary slick of each of
three types of oil: diesel, 40-weight motor oil, and Bunker
"C" fuel oil. The slick thickness range is from 0.1 to 2.0
inches, corresponding to a dimensionless thickness range
from 1.3 to 27.
Figure 2: Oil Boundary-Layer Formation on Disk
Figure 4: Theoretical Model Results
-------
332 PHYSICAL REMOVAL .
Figure 5: Comparison of Theory with Experiment - No Current
z
FIVE DISKS WITH VARIOUS SPACINGS
>• CURRENTS UP TO 3 KNOTS
FLAGGED SYMBOLS = WATER CONTENT
"AM WEIGHT OIL ~
_ O BBNKER 'C'
Q =
a I*
Figure 7: Disk-Oil Relationship
It is noted that quite a few of the data points (flagged
points) signify pick-up with water, due to starvation of the
disk, especially in the cases of thin slick. The general
agreement between theory and experiment is, however,
satisfactory, especially in view of the fact that the values
vary over four orders of magnitude.
The simplest way to avoid disk starvation is to cause
relative motion between the disk system and the slick so
that the slick can more readily feed the disk. This has been
done experimentally in a towing basin with a 5-disk system
moving through oil at speeds up to 3 knots, with two types
of oil-40-weight motor oil and Bunker "C" fuel oil. The
results are shown in Figure 6. It is seen that there are far
fewer points with water pick-up than in the stationary case.
Figure 6: Comparison of Theory with Experiment - With Current
Figure 8: Disk Wiper System
-------
ROTATING DISK RECOVERY SYSTEM
333
Further analytical efforts are under way to predict
water pick-up as a function of the disk rotation rate. In the
meantime, some assessment of the limiting rotation rate
can be made empirically from the experimental data in
Figure 6. It is tentatively established that a limiting w of 60
can be used for 40-weight motor oil and 100 for Bunker C
fuel ofl. The limiting c3 for diesel oil is estimated conserva-
tively at co = 1 from the data in Figure 5. Once a limiting 53
is specified, the corresponding maximum pick-up rate Q can
be found from Figure 4 for the appropriate value of the
dimensionless slick thickness d~.
The total pumping rate that can be achieved by a
system of disks depends then only on the number of disks
employed. The spacing between disks would be large
enough to prevent the oil from filling the space and re-
ducing the pumping effectiveness of the disks. The min-
imum spacing would be given by the widths of the oil layers
on the disk surfaces plus the width of the oil fillet between
these layers. From Figure 7, the width of the oil layers is
and the width of the fillet is not more than 2 y/pghmjn ~ Y i
where hm;n is the height of the fillet trough. For y = 18hrain
/Z\ (13)
or
and
nun
mm
6 (15)
The minimum spacing would then be
(16)
For a deep slick,
max
= 2 (JL / y « C, which is the worst case.
With Bunker C the largest value of £ max is of the order of 200, and
tfarjT k/201 -1 + 3\/§~ = 4.6 cm = 1.8 inches (17)
mm
-------
334 PHYSICAL REMOVAL . . .
Similarly the minimum spacing the thick layers of 40
weight and diesel oils are calculated to be:
Diesel Oil 0.98 cm or 0.38 inch
40 weight 3.4cm or 1.3 inch
It is noted that these minimum spacings are independ-
ent of the size of disk.
Some sample design calculations have been made for a
full scale system capable of pumping 50,000 gallons per
hour of oil free of water. The results are shown in Table 1.
It is seen that to achieve a pumping rate of 50,000 gal/hr.
only a relatively modest system is required. The greatest
burden in such a system is imposed by a thin slick of low
viscosity oil; although, even there, the overall system is not
too massive.
Table 1 Design Parameters for MultipDisk System with Capacity of
50,000 Gallons-Hours ,
Disk Diameter 7 feet
Disk Immersion Chord 6 feet
Slick Thickness
Limiting Disk Rate
Max Pumping Rate
Number of Disks
Disk Spacing
System Length
77.0
Diesel
40-Weight
77.0
2.0
13.0
9.0
2.0
2.0
Bunker C
d
d
Oi
max
u>
~Q
^max
Q
max
(single disk)
1 mm
0.54
1.0
36.0
0.03
650.0
1 inch
13.7
60.0
20.0
30.0
5,700.0
1 inch
13.4
100.0
3-6 rpm
65.0
1,470.0 gal/hr
34.0
2.0 inches
6.0 feet
Relative Cuttent Speed - 2 knots for all cases
-------
ROTATING DISK RECOVERY SYSTEM 335
A wiper design not unlike a stationary windshield
wiper blade on each face may be used to recover the oil
from the disks. The oil is gravity fed into a trough between
the disks and into a collector.
ENDLESS BELT
SUMP
DISK
Figure 9: Endless Belt Wiper Concept
A second method may be to direct the oil from the
wiper into a central hub where it is pumped to the storage
reservoir. This is shown in Figure 8. An Archimedes' screw
can be used to pump the oil in the hub to the storage
reservoirs.
Figure 10: General Arrangement-Oil Recovery Subsystem
A third concept employs an endless belt to wipe and
transport the oil to the reservoir as shown in Figure 9. The
reservoir would be located well above the surface of the
water to minimize water intrusion in high sea states. One of
the major advantages of this type of wiper system is that it
tends to act as secondary separator. A portion of the water
picked up by the disks will separate from the mixture and
run off the belt. However, effectiveness of this design and
its ability to transport large quantities of viscous oil will
have to be determined by comprehensive functional tests.
STORAGE BAG
Figure 11: Recovery System Concept - Configuration No. 1 and
Alternate
OIL CONTAINMENT
BARRIER
STORAGE BAG
Figure 12: Recovery System Concept - Configuration No. 2
-------
336 PHYSICAL REMOVAI
The oil recovery system can be supported by a
platform that is shaped for low drag and to direct the oil to
the disk with minimum of turbulence. Because the oil
recovery effectiveness and efficiency is influenced to a
degree by the platform motion, sea kindliness of the
platform is desirable.
A candidate concept platform is the catamaran
configuration as shown in Figure 10. The recovery disk unit
is located at the longitudinal center of gravity between the
two hulls so that the disks will be affected little by the
pitching motion. The hull is contoured into a shape of a
converging-diverging nozzle with the disks located at the
throat.
Care must be taken to design the forebody of the hull
so that is has a smooth entry into the water during pitch.
This will eliminate any violent slamming which can disturb
the oil near and around the hull.
The catamaran can be equipped with a portable barrier
which can be lowered between the hull just aft of the
recovery unit again near the center of gravity, creating a
containment section between the hulls. The barrier is raised
for towing.
A debris guard is provided across the bow of the
platform to prevent large debris from damaging the disks. It
is expected that the debris would be shallow floating
objects which permit the oil to drain past them with little
resistance and should not affect the performance of the
disks significantly.
O!L CONTAINMENT
BARRIER
TRANSFER BUOY-
OII, CONTAINMENT
DA Rill EH
RECOVERY
SUBSYSTEM
TRANSFER BUOY
STORAGE BAG
Figure 14; Recovery System Concept - Configuration No. 3
Alternate
Figure 13: Recovery System Concept - Configuration No. 3
Catamarans typically have a high degree of transverse
stability. The transverse metacentric height is usually of the
same order of magnitude as the longitudinal metacentric
height; and in some cases, transverse stability is greater than
longitudinal stability. In conventional size ships, this high
degree of stability may be excessive for human comfort
because rolling motions tend to be very quick. For a small
unmanned catamaran such as the oil recovery vessel, this
should not be a problem. The potential advantage of this
type of system would be the minimum motion imparted to
the disks under high sea state conditions.
Possible concepts for the use of the disk system in
conjunction with moored barriers are shown in Figures 11
through 14. A comparison of the salient features, with the
advantages and disadvantages are presented in Table 2. The
recovery system with herding booms may also be towed
through a spill for oil pickup.
-------
ROTATING DISK RECOVERY SYSTEM 337
MAJOR FEATURES
ADVANTAGES
DISADVANTAGES
a) HOSE CONNECT FROM RECOVERY
UNIT TO PICK UP BUOY FOR OIL
TRANSFER.
a) INCREASES PICK-UP
EFFECTIVENESS.
a) MAKES MANEUVERING OPERA-
TION OF RECOVERY UNIT
CRITICAL.
b) LOADS INTERACTION BETWEEN
PICK UP BUOY, TRANSFER
PIPE AND RECOVERY UNIT.
INCREASES SURVIVABILITY
PROBLEM.
CONFIGURATION NO. 2
MAJOR FEATURES
a) RECOVERY UNIT IN LINE WITH
MOORED BARRIER. CLOSURE
BARRIER BUILT INTO RECOVERY
UNIT.
b) PICK UP BUOY SEPARATELY
MOORED ACTS AS ANEBAR
FOR BAGS AND AS SPRING
BUOY.
ADVANTAGES
a) SIMPLEST MOORING
OPERATION.
b) HIGH PICK UP RATE.
s
DISADVANTAGES
a) LOADS AND MOTION INTERACTION
b) LIMITED TO 1 KNOT CURRENT
C) BARRIER AND RECOVERY UNIT
DEPLOYED CONCURRENTLY.
d) PICK UP UNIT DIRECTIONALLY
ORIENTED.
Table 2a: Comparison of System Configurations
MAJOR FEATURES
a) MOORED BARRIER
b) SELF PROPELLED RECOVERY
UNIT WITHIN BARRIER
c) STORAGE BAG EXTERIOR TO
BARRIER WITH PICK-UP BUOY
MOORED INSIDE OF BARRIER
RING.
ADVANTAGES
a) BARRIER AND RECOVERY
UNIT INDEPENDENT
SYSTEMS.
MINIMIZES LOADS AND
MOTION INTERACTIONS,
MAKES SURVIVABILITY
PROBLEM SIMPLER AND
RECOVERY PREDICTIONS
MORE ACCURATE.
b) RESPONSE TIME FOR
RECOVERY UNIT
INDEPENDENT OF
BARRIER.
DISADVANTAGES
a) RECOVERY UNIT MUST BE
PROPELLED WITH AIR JET
TO PREVENT OIL WATER
MIXING BY PROPELLER.
b) CAPACITY OF RECOVERY
UNIT LIMITED THUS REQUIRING
FREQUENT TRANSFER OF OIL
TO BUOY.
c) MOORING OF INTERNAL BUOY
REQUIRES SHIP INSIDE OF
BARRIER, UNDESIRABLE DUE
TO CLOSE QUARTERS FOR
OPERATION.
d) CANNOT RECOVER OIL WITH
25 FEET OF BARRIER.
e) LIMITED TO 1 KNOT CURRENT.
f ) RECOVERY UNIT MUST BE
MANNED.
Table 2b: Comparison of System Configurations, (Configuration
No. 1 Alternate)
-------
338 PHYSICAL REMOVAI
MAJOR FEATURES
ADVANTAGES
DISADVANTAGES
a) RECOVERY UNITS IN TANDEM
DISK SPACING PROGRESSIVELY
BECOMING NARROWER IN DOWN
STREAM RECOVERY UNITS. DISK
IN LAST UNIT SPACED FOR COM-
PLETE OIL PICK UP.
b) PICK UP BUOY SEPARATELY
MOORED ACTS AS AN ANCHOR
FOR BAGS AND AS SPRING
BUOY.
c) BARRIER IN HERDING ARRANGE-
MENT.
a) OPERATIONAL CURRENT LIMIT
INCREASED TO 2 KNOTS OR
GREATER. OIL AND WATER IS
ALLOWED TO PASS THROUGH
THE RECOVERY UNITS AND NO
HEAD WAVE IS ALLOWED TO
FORM. DISKS IN LAST RECOV-
ERY UNIT IN SYSTEM ARE
SPACED FOR CLEAN PICK-UP.
b) HIGH PICK-UP RATE.
a) COMPLICATES MOORING
b) MOST COMPLEX LOADS AND
MOTION INTERACTION.
c) BARRIER AND RECOVERY
UNIT DEPLOYED CONCUR-
RENTLY.
d) PICK-UP UNIT DIRECTIONALLY
ORIENTED.
CONFIGURATION NO. 3 ALTERNATE
MAJOR FEATURES
ADVANTAGES
DISADVANTAGES
a) RECOVERY UNITS IN TANDEM
MOORED SEPARATELY FROM
BARRIER.
a) BARRIER AND RECOVERY
UNIT INDEPENDENT SYSTEMS
MINIMIZING INTERACTIONS
OF LOADS AND MOTIONS.
b) DEPLOYMENT OPERATIONS
SIMPLIFIED.
c) RESPONSE TIME FOR
RECOVERY UNIT INDEPEN-
DENT OF BARRIERS.
a) LOSS OF OIL CAN OCCUR
BETWEEN GAP OF BARRIER
AND HERDING BOOM IF THE
DIRECTION OF WIND AND/OR
CURRENT SHOULD CHANGE
DURING THE OPERATION.
Table 2c: Comparison of System Configurations, (Configuration
No. 3)
CONCLUSION
. A disk type oil recovery system offers:
(1) A high pick-up rate
(2) Capability to pick up oil spread as thin as 1 nun
(3) Capability to pick up light diesel as well as Bun-
ker •€' oil
(4) Relative insensitivity to waves and current
(5) Low tendency to disturb and emulsify the oil
during pick-up
(6) Relative insensitivity to oil condition such as
emulsification
(7) Efficient oil-water separation
(8) Relatively debris-safe
This study has shown that a disk system is effective
and practical and can be a valuable tool in the control of oil
spills.
-------
LOCKHEED OIL SPILL
RECOVERY DEVICE
Barrett Bnich
and
K.R. Maxwell
Ocean Systems
Research and Development Division
Lockheed Missiles & Space Company
ABSTRACT
Tests and analysis of an oil spill recovery device with
various oils, under fonvard way and with waves, established
a method for estimating performance and verified fonvard
way scaling to be by the square-foot of the device diameter
and oil recovery rate by the 5/2 power.
An 8-ft-diameter, 10-ft-long device in sea state 4 and a
2-kt current could recover 8,600 bbls of light oil per day
with less than 25 percent additional free water and in calm
seas, 17,200 bpd. Within containment booms, 1 to 4 in. of
oil are required for maximum recovery. Natural emulsion
recovery is double the light oil rate. The device does not
create emulsion.
Above 2 kts, oil recovery remains maximum while
free-sweeping slicks over 1/2-in. thick. With thinner slicks,
the rate decreases linearly down to at least 0.01 in. Tests
established 70 percent recovery of oil encountered on a
single pass. This can be increased by successive passes.
Free-sweeping in calm seas is feasible up to 5 kt.
INTRODUCTION
The design concept described here for a high-seas oil
recovery system is based on the use of a Lockheed
proprietary oil recovery device. Much of the test data
verifying the feasibility of the concept were derived from a
U.S. Coast Guard sponsored engineering evaluation
program. (DThe opinions or assertions, however, are the
author's private ones and should not be construed to be
official views of the commandant or the Coast Guard at
large.
The recovery device picks up oil on both sides of a
number of closely packed vertical discs, which are
nominally half immersed in the sea. The rotation of these
discs through a layer of oil creates a viscous shear which
attaches the oil to the discs in the manner shown in Fig. 1.
VANE CONNECTING
ADJACENT DISCS
SCRAPER
ROTATING DISCS
STATIONARY HOLLOW
SHAFT - OPEN AT TOP
OIL FREE
CLEAR WATER
DISCHARGE
Figure 1: Cross-Section Sketch of Device
Disc rotation is fast enough to allow the oil to remain
on the discs until it is removed by scrapers, but is not
sufficient to carry the less viscous water which also does
not readily adhere to the oil.
The discs are held in position by horizontal vanes
attached on the disc peripheries and supported by end
plates on a stationary support shaft. The vanes act to ingest
oil and water. An overlap of the vanes traps the oil to allow
its thickness to build up so that the discs can operate at
maximum effectiveness in thin slicks. However, if
oversupplied. the excess oil will be bypassed.
The ability to operate in thin slicks is necessary to
perform effective recovery operations with thin layers of oil
within a containment boom and with thin patches that have
escaped containment.
339
-------
340 PHYSICAL REMOVAI
High reserve buoyancy flotation can provide quick
heave response to most open sea waves, but the device must
have some compliance to operate efficiently at immersion
depths off of the nominal still water line to cope with short
and steep waves.
The Recovery Problem
As described by Fay(2) and Hoult(3 and 4)> after the
first hour, an oil spill spreads at a rate independent of the
amount spilled and fast enough to demand rapid control
measures to capture a recoverable thickness and to prevent
wind and current from beaching the oil.
If containment booms cannot be used, the problem
compounds so that after 20 hours the spread rate reaches
1.2 million square feet per hour, as determined by Cochran,
et al. (5) If sweeping is attempted at this point, in lieu of
containment, a 100-ft swath would have to be swept at 2
kts to keep up with the spreading. Additional width is
required proportional to the square of any further delay.
The oil thickness can be considered uniform; hence,
dependent on the amount spilled. If the spill continues in
the presence of current and wind, further enlargement and
elongation will occur.
If a containment boom is used and there are waves
present, the boom's effectiveness will degrade depending on
its draft and heave compliance. In a calm water current, a
head wave thickening of the oil occurs at its leading edge.
However, with waves, there is some speculation whether a
stable head wave forms. According to the preceding
references, and ignoring the head wave and assuming a
distance near the boom of about five times its draft, d,
where the oil is a thickness, ho; the leading edge of the oil
extends a distance, Xie, ahead of the boom apex in a
current, u, and with a sea water-oil fractional density, A, ast
follows:
= 5d +
Agh20
(0.72)2U2
(1)
Likewise, the oil depth, hx, at a given distance, x, from the
apex of the boom varies as follows:
. (0.072)2u2(5d -x)
(2)
, for:x 5d
The location of the leading edge and the thickness
distribution affect the operation of any oil recovery
system. The above equations show that the contained oil
slick will decrease rapidly in size and thickness with
increasing current, and oil specific gravity. In waves, ho will
also decrease significantly.
There is a basic limitation on the still-water oil
recovery rate which is independent of the detailed recovery
method. This limitation depends on the gravity-inertial
feeding of oil from the pool to the recovery device. The
phenomenon is analogous to open-channel critical flow and
has been discussed by Cross and Hoult(5). The recovery
system must accelerate the oil in the stagnant pool toward
itself to achieve the desired flow rate Q. However, the limit
to the oil velocity, V, is about
- 2gAhs
(3)
With W as the width of the oil recovery device, the resultant
maximum oil removal rate Qmax is:
Qmax ^Wh^2 2gA (4)
When the recovery device is placed inside an oil
containment boom, either moored in a current or towed as
a sweep, upstream the oil has a relative velocity. However,
the boom causes the oil to pile up and downstream from
the leading edge, the oil is nearly stationary relative to the
recovery system. As a first approximation, it behaves like
that in the above stagnant pool description.
A graph of the flow limitation per foot of recovery
device intake as a function of oil depth for several specific
gravity oils in shown in Fig. 2. Likely maximum recovery
points for the Lockheed device are also shown for later
reference.
200
pOIL
p WATER
• LIKELY MAXIMUM RECOVERY
POINTS
246
OIL POOL DEPTH ~ INCHES
Figure 2: Maximum Flow Rate Toward An Oil Recovery Device Per
Unit Width From a Stationary Oil Pool
-------
LOCKHEED RECOVERY DEVICE 341
This gravity flow does not apply if the oil recovery
device is attached in the apex of a "U"-shaped or echeloned
boom and recovers oil at the same rate it is encountered. In
this case, Qmax is the multiple of sweeping speed, swath
width, and slick thicknesses.
The advantages of placing the recovery device inside a
stationary boom are: any oil bypassed through the device
can be reprocessed; the contained oil acts as a buffer
storage for uneven oil encounter rates and there is a
minimum interference with the boom's dynamics. The
disadvantage is that the recovery device must be
maneuvered and maintained in relatively close proximity to
the boom but must avoid physical contact. Also, oil feeding
to the removal device is limited to the gravity-inertia!
mechanism to drain the stagnant pool.
The advantages of placing the recovery device at the
apex of a sweeping boom is that the device may be
force-fed without the gravity-inertial limit from a wide
sweep mouth. This might be advantageous with the oil
emulsifiedd to such a high specific gravity that it has a low
feed rate from a stagnant pool. It sacrifices the advantages
of placing the device inside the boom.
Although sweeping free-spreading oil by the recovery
device without a boom is not very attractive, weather may
not permit early containment of a spill, yet may allow
sweeping. Hence, some effectiveness under these conditions
could be of great value in reducing the impact of a
storm-dispersed slick.
Theory of Operation and Test Verification
The oil and water that flows between adjacent discs
and into the recovery device passes through overlapping
vanes. The overlap keeps oil from escaping up to a certain
limiting input thickness. However, the vanes can also
potentially choke the oil flow into the device. The
maximum flow rate is a function of the oil viscosity and the
shape of the restricted disc and vane formed rectangular
passage". The geometry is described in Fig. 3.
For a round circular pipe of radius, ro, the volumetric flow
rate, Q, of an oil viscosity n through the pipe is given by
dp
dx
(5)
dx
= pressure gradient.
As an approximation, the rectangular passage on the disc of
radius, r, rotating at cj rpm can be treated as an equivalent
pipe with identical cross-section. The velocity in the
rectangular channel, u, is:
where 6 = angle the vanes make with a tangent to the outer
radius. Assuming that the entire rectangular passage of
length, 17, is filled with oil of density, p0,and that the oil
shows to near zero velocity after passing through the
channel, the pressure gradient can be approximated by
dp =
dx
co
s2fl
lb
(7)
Then, where r'o is an equivalent pipe radius, Eq. (5)
becomes
= ^L 1/2 (rcocosfl)2 4
8
V
(8)
Substitution of Eq. (8) for an 8-ft-dia. device with three
passages formed by 2-in. disc spacing and 10-deg spacing of
8-in.-long vanes simultaneously flowing gives
27xl03
(9)
where
Q = flow rate between the vanes in GPM
v = viscosity in Cst
Once the oil enters the device, buoyancy causes the oil to
rise to the surface and form a pool. Unless there is
sufficient oil present to saturate the device, the trapped oil
layer builds up to a thickness, h, much greater than that of
the slick. The layer acts as a buffer storage in waves where
the oil ingestion rate varies.
If sufficient oil is present, the device becomes saturated
and the oil escapes through the vanes. However,
observations during static tests show a substantial tolerance
between the minimum depth that supports maximum
recovery and the depth that saturates the device.
The oil that remains inside the periphery of the device
adheres to the disc through viscous action. The oil quantity
that adheres to the disc can be estimated using the theory
for the sudden acceleration of a plate from rest in a
stationary fluid. The rotating disc replaces the moving plate
and the floating oil layer of kinematic viscosity, v,
represents the stationary fluid. The results from the analysis
show that
r3/2
(10)
u = r
cos 6
(6)
Gravity action on the ascending disc, discussed later, limits
the recovery rate. However, Eq. (10) defines the minimum
thickness required to maintain a given recovery rate and
tests with a plain disc verified this.
As oil is removed, fresh oil flows toward the disc by gravity
action.
Q Ah3/2
-------
342 PHYSICAL REMOVAL
Rectangular
Passage
Figure 3: Vane - Disc Geometry
As the disc rotates into the water, the oil boundary
layer is acted upon by viscous shear at the water/oil
interface, causing a secondary flow of the water in both the
radial and circumferential directions. Experiments showed
that the flow field at the ascending disc side causes a water
head rise which forms a physical barrier between the
surrounding oil and the ascending disc. Thus, the only oil
that adheres to the disc is that picked up when the disc
descends.
Figure 4 (Continued)
Figure 4 shows the surface flow pattern on a 2-in. layer
of diesel oil as the 5-ft disc descends at 10 rpm and the
water head rise at emergence. Figure 5 shows the How
pattern of the oil on the disc as it approaches the wiper.
When the disc emerges, the oil layer attached to the
disc is acted upon by gravity and centrifugal acceleration to
result in a curved trajectory for a particle of oil that is
carried to the wiper. An approximate computation of the
oil layer thickness can be made by applying the theory for a
plate withdrawn from a liquid. Centrifugal force is
neglected because the ratio of centrifugal force to gravity is
of the order of a tenth or less. The vertical pattern of the
oil in Fig. 5 confirms the predicted lack of centrifugal force
effect.
Figure 4: Descending and Ascending Sides of Disc
Figure 5: Flow Pattern of Oil Layer on the Disc
-------
LOCKHEED RECOVERY DEVICE 343
For a recovery device operating at 10 rpm and u = rco
~ 100 cm/sec; and with an oil of ^ = 10 cp and a = 40
dynes/cm Ref. (1) shows that the effects of surface tension
on oil recovery rate are negligible provided that the
capillary number is much greater than one. In this case,
/uuo/a = 25. Thus, viscous and gravitational forces dominate
and within the supply limit of Eq. (10) the theory applied
to the ascending disc shows that
(12)
Q = pl/2g.l/2w3/2r5/2.forQ 14 rpm. The grass recovery continued to increase with
a larger water content at higher to. One possible reason is
that all devices with vanes have geometirc similarity and
may generate turbulence that limits oil recovery and
encourages water pickup at identical rotational speeds.
Figures 7, 8, and 9 show the model devices used to
obtain the data shown in Fig. 6. Also, static tests with the
5-ft disc showed negligible sensitivity to heel angles up to
40 deg as shown in Fig. 10. Similar tests with the varied
models also showed no heel sensitivity.
The predicted increase with viscosity was not evident
in tests although recovery did increase by as much as a
factor of 5. Figure 11 shows these test results, and a rough
empirical curve. Several experimental factors that could
account for the discrepancy include: insufficient oil in the
calm pool, choked flow at the vane inlets, choked flow at
the wipers, and choked flow through the shaft. Further
testing is being conducted to better define the sensitivity of
viscosity since this is the single most important oil
parameter that affects the recovery device operation.
Recovery effectiveness theoretically varies with the
square root of the viscosity and typical viscosities range
from 1 to 104 cSt for light fuel oils to heavy residuals. The
2.0
H 1.5
S
s
z
1.0
0.
I I I
O 10-INCH-DIAMETER DEVICE, PARAFIN - v = 5. 86 CST
D iO-INCH-DIAMETER DEVICE, DIESEL - i> = 5. 65 CST
+ 10-INCH-DIAMETER DEVICE, WATER ONLY - v = 1.0 CSr:
A 5-FOOT-DIAMETER DISC, DIESEL - v = 5. 5 CST
D 3-FOOT-DIAMETER DISC, DIESEL - v = 6.0 CST
k 24-INCH-DIAMETER DISC, DIESEL - v = 6.0 CST
O 24-INCH-DIAMETER DISC, PARAFIN CRUDE - v = 5.9 CST
X 11-INCH-DIAMETER DEVICE, JP-5 - " = 0.7 CST
I I i I I I I I I I I I
- DISC ROTATIONAL SPEED (RPM)
Figure 6: Normalized Test Data for the 10-in. and 24-In. Device and
the Single Disc as a Function of Disc Rotational Speed
-------
344 PHYSICAL REMOVAL .
influence of surface temperature, T, on the recovery
effectiveness should only be related to the manner in which
viscosity affects recovery effectiveness so that
where
,K/T
where v
,K/T
(13)
The importance of surface tension to recovery
efficiency (percent net oil to gross recovered material) can
be deduced from static testing of seasoned oily discs in
Figure 7: The 10-In. Diameter Model
water free of an oil slick. Figure 6 shows at the selected
12-rpm rotational speed that water pickup using an oily
(hydrophobic) disc was only 13 percent of theoretical for a
hydrophillic disc. It is assumed this degradation is due to
surface tension. Taking both this surface tension effect
and that of the water viscosity into account, the water
pickup rate would be 6 percent of that for diesel oil.
However, when oil is present, the outside of the oil layer
moves at a lower velocity than the disc; thence, water
pickup is still lower. Measured static test values of recovery
efficiency with fresh diesel exceeded 99 percent. With wet
oils and paraffinic crude under forward way and in waves,
this degrades and water entrains as free droplets on the
surface of the disc. Under way and with waves, the
submerged oil layer on the discs is affected and
irregularities allow additional water to become attached.
The performance under these conditions is discussed
subsequently.
When the oil is carried to the wiper, it flows in a layer
of thickness, 5, down to the shaft at a mean velocity u1, by
gravity action and into a trough of width, w. The flow rate
into the shaft, Q = u'5w, and
from boundary layer theory.
The maximum flow rate occurs when 5 equals half the
gap between the discs. For a device with a 2-in. disc spacing
and a 6-in. through width, the maximum flow rate of oil
with kinematic viscosity, v, in cSt to the hollow shaft per
disc is
n _ 25.7 x 1CP
Q gpm
(15)
Comparison of Eq. (9) for the flow intake limitation
with Eq. (15) for the flow down the wiper shows similar
results. Botj equations are quite approximate for estimating
flow "choking" conditions but when the more conservative
Eq. (9) is used with Fig. 1 1, the recovery rate as a function
of viscosity can be estimated. The recovery rate for low oil
viscosities is given by Eq. (12). With v = 6 cSt, CL> = 12 rpm,
and R = 4 ft, the predicted recovery rate is about 10 gpm
per disc. When this rate is combined with the Fig. 11
empirical curve, rather than the Eq. (12) Q
-------
LOCKHEED RECOVERY DEVICE 345
O FORWARD WAY TEST
I NO FORWARD WAY
100
OIL VISCOSITY. cSt
Figure 11: Oil Recovery Rate as a Function of Viscosity
1000
10000
Viscosity and specific gravity of oils are generally
related. The higher the specific gravity, the more viscous
the oil is. For v = 750 cSt, a typical specific gravity is 0.95.
Figure 2 shows that in a static pool at least 3 in. of oil is
required to achieve maximum recovery.
When the recovery subsystem is moving at a forward
way, u, with respect to the stationary oil pool of thickness,
h0, the oil flow rate to a device of width, W, is
Q = u h0 w
(16)
However, the recovery rate as predicted by Eq. (12) is
also modified by the forward speed. Experiments,
conducted with the 1/4-scale device (24-in.-diameter)
shown in Fig. 13, showed that when the speed is increased
from zero up to a critical value the recovery rate is
approximately equal to either the recovery potential from
Eq. (12) or the encounter rate from Eq. (16), whichever is
less. The critical speed can be scaled with the densimetric
Froude number, F = u^/gAr; and, the critical Froude
number was found to be 0.53.
For speeds greater than the critical speed, the recovery
rate for a given thickness declines. The reasons for the
decline are probably some combination of flow under the
device (drainage) and a breakdown of the mechanism by
which the oil adheres to the disc. The results of tests with
the 1/4-scale device and the experimental test conditions
and their full-scale equivalents are noted on Fig. 13.
Experiments show that for a constant forward way above
the critical speed, the recovery rate is proportional to the
thickness of oil, as shown in Fig. 14. This graph implies that
the ratio of oil recovered to oil encountered is constant.
Using these criteria, the oil recovery rate is assumed to
increase with thickness until the capacity of the device is
exceeded, at which time the recovery rate is computed and
-------
346 PHYSICAL REMOVAL . . .
adjusted by an appropriate recovery (water content)
efficiency, rjw, that depends on forward way and which has
been experimentally determined as shown in Figure 15.
The recovery efficiency and oil bypass are both related to
the depth of the captured pool of oil in front of the device.
The Froude number equation relates oil depth and water
velocity with the drum radius as the characteristic
dimension. The scaling law implies that for larger drums the
captive oil pool depth increases for a given forward way and
more oil is ingested into the device and recovered. By
Froude scaling the forward way and assuming that the ratio
of oil recovered to oil encountered is constant, a method
was generated to scale the 1 /4-scale model data for recovery
effectiveness and efficiency as shown in Figs. 13 and 15,
respectively. The derivation of the method is given in Ref. 1
and the results are
Q = min
(17)
where
C = recovery drum length
Qmod = m°del recovery rate shown in Fig. 16
RECOVERY RATE PER DISC (GPM)
I.
^3:
Figure 12: Recover} Rate of the Proposed Prototype for Different
Oil Viscosities
The predicted recovery rate based on Eq. (17) with low
viscosity oil (v = 6 cSt) for an 8-ft-diameter by 10-ft-long
device with a 2-in. disc spacing in calm water is shown in
Fig. 16 as a function of forward way and oil thickness. The
buildup for thin slicks is a composite of the Fig. 2 spreading
rate and the physical encounter rate, whichever is greatest
until the recovery device capability is reached. The scaled
data for the 1/4-scale device is the basis for the predicted
curve. The scaled data from the 1/9-scale model lie slightly
below the prediction, but generally confirm the scaling
method.
Figure 16 also shows that up to 2 kts. for slick
thicknesses less than 0.3 in., less oil is encountered than can
be recovered. At speeds greater than 2 kts, the recovery rate
declines only gradually with increased forward way.
The Froude number equation states that the amount of
oil bypass under the device due to drainage increases as the
specific gravity increases. Measurements were made with
emulsified diesel of specific gravity between 0.93 and 0.°-7
and with clean oil of 0.87 s.g. Thus, the fractional density,
A decreased roughly 75 percent. However, the viscosity
increased by 105. The experimental effect under forward
way was inconclusive with regard to specific gravity since
the recovery rate with the highly emulsified diesel was
sometimes fivefold that of clean diesel. It has been
speculated that Froude Number scaling of dimensions and
speed for a given oil may still be valid even though it can
not be demonstrated with different oils. The reason is that
the large increase in recovery due to viscosity increases the
throughflow of oil and probably affects the drainage
criteria which takes no account of throughflow. In any
event, it appeared that specific gravity is a second-order
effect compared to viscosity.
The analysis assumes that oil flow under the device is
principally caused by the drum acting as a flow obstruction
and the data support this contention. Tests at high drum
rotational speeds show an absence of a visible bow wave in
front of the drum, and it appears that all of the oil flows
into the drum. However, the pickup mechanism does not
work efficiently (large amounts of water are collected) as
can be seen in Figs. 13 and 15.
The addition of waves to both calm water and while
under way results in a degradation in recovery effectiveness
and efficiency. Tests plotted on Figs. 13 and 15 showed
that this degradation could not be described in terms of
some time averaged change in immersion depth, and that
the recovery rate in waves is dependent upon both
amplitude and forward way. The experimental data suggest
that either the oscillation motion somehow prohibits the oil
from entering the drum or the film attachment mechanism
breaks down. Estimations of the breakdown have not been
made since the physical processes governing the pickup
failure are not known. Visual observations noted that as the
drum descended into the water as a result of the heaving
motion, the surging action pushes the oil that was at the
-------
LOCKHEED RECOVERY DEVICE
347
face of the drum downward where it can pass under the
drum. A picture of this is shown in Fig. 17. Because of the
complex nature of the flow field in the presence of waves,
the degradation of performance with waves is obtained
from experimental data.
The ratio of recovery rate in waves to that in no waves.
Qw/Ou- can be obtained from Fig. 13. The speed and wave
height can be Froude-scaled and the degradation in
recovery effectiveness for the proposed prototype can be
scaled. The degradation is shown in Fig. 1 8 as a function of
wave height for different forward way speeds. The recovery
efficiency is shown in Fig. 15.
The results shown in Fig. 18 are based upon
experimental data conducted in the Lockheed Ring
Channel shown in Fig. 19. The results in Fig. 16 can be
multiplied by the degradation shown in Fig. 18 to predict
prototype recovery in waves while under way.
The test procedure used to generate the experimental
data for wave degradation consisted of sinuosoidally driving
the recovery device at the prescribed amplitude and
frequency. The test conditions depended upon the response
characteristics of the recovery device mounted in catamaran
hulls pictured in Fig. 20 and 21 and measured on 1/9-scale
model tests in the Lockheed tow and wave tank. The tesl
results from photographic data were analyzed over a range
of wave frequencies and length. The Pierson-Moskowitz
energy spectrum for a random sea was applied and the
result is shown in Fig. 22.
The tests conducted in the Lockheed Ring Channel
only approximated the motion of the drum. Also, the data
presented in Fig. 13 are over a narrow wave period range
and the sensitivity of recovery effectiveness with period is
not known. Future work will eliminate this problem by
measuring recovery rate with a working model of the device
while the model is being towed in regular and random
waves through the range of interest.
10
NET OIL
RECOVERY
RATE
(GPM)
WAVES
AMPLITUDE
± 1"
± 2"
± 2-1/2"
± 3-1/2"
* 4-1/2"
± 5"
j ! | . j Tr*h«f>H^
3
:::::::::::: -\
24-INCH DIA DEVICE
PERIOD CODE DIESEL OIL
3.QSEC 1/4 SHADED FILM THICKNESS
3.0 SEC 1/4 SHADED VISCOSITY = 5 1
3.0 SEC 1/4 SHADED DRUM ROTATIONAL
3.0 SEC 1/2 SHADED _
2. 6 SEC 3/4 SHADED O = 4.5 RPMl
2.0 SEC FULL SHADED A = 7.0
i •' ii" in D = 9.5 _)
O= 12 RPM
3- r+~-"T 0= 18RPM
= .04 IN.
O 8cSt
SPEED
NORMALIZED
TO 12 RPM
^
HI::
^.
^±| ::::: \. 0
~~I~~ III IJ-LJ-L
FOKWAJtt) WAY - (ITS)
Figure 13: Recovery' Rate of the 1/4-Scale Device With Forward
Way With and Without The Presence of Waves
-------
348 PHYSICAL REMOVAL
s
0,
g
K
H
X
w
C 4
O
0
O
I
9
OIL TYPE -DIESEL, ;• = 6 CST
DRUM ROTATIONAL SPEED = 10 RPM
ADVANCE RATE = 2.7-2.8 FT/SEC
-------
LOCKHEED RECOVERY DEVICE 349
234
FORWARD WAY (KNOTS)
Figure 16: Full-scale Predicted Oil Recovery Rate vs. Forward Way
for Law Viscosity Oil
Figure 17: Extremes of Wave Heaving for Device Under Forward
Way at 17 rpm
-------
350 PHYSICAL REMOVAL .
Figure 17 (Continued)
NOTE: THE FULL SCALE SPEEDS IN KNOTS IDENTIFY
EACH CURVE.WAVE PERIOD = 5 SECONDS AVERAGE
WAVE HEIGHT (FT)
Figure 18: Oil Recovery Rate in the Presence of Waves as a
Function of Heave Amplitude of the Drum for Different Tow
Speeds
Figure 19: Lockheed Ring Channel and Model Carriage
-------
LOCKHEED RECOVERY DEVICE 351
Figure 21: Model With Minimum Waterline Height
Figure 19 (Continued)
PERCENT OF TIMF. WATER HEIGHT IS GREATER THAN HW
«0 50 10 1 0.1 0.01
0.01 0.1 1
PERCENT OF TIME WATER HEIGHT IS LESS THAN H
Figure 22: Water Height at Bo\v and Stern - Frequency of
Occurrence in 1-Foot Significant Wave Height Seas at Tow Speed of
5 knots
CONTAINMENT BOOM
STORAGE BAGS
Figure 23: Sketch of Deployed System
Figure 20: Model With Maximum Waterline Height
-------
352 PHYSICAL REMOVAI
OIL RECOVERY DEVICE
AIR EXHAUST
SNORKEL
LOA
BEAM
HEIGHT.
DRAFT_
DISPLACEMENT.
OPERATING
-36FT-10IN.
.21 FT-101/2IN.
_12 FT-5 IN.
-2FT-11 IN.
. 22,400LB
(FULL LOAD)
SIDE VIEW
AIR INTAKE-
FRONT VIEW
-AIR INLET
HULL CENTER SECTION
Figure 24: Concept Arrangement of Oil Recovery System
-------
LOCKHEED RECOVERY DEVICE 353
2500 i—
2000
o
1500
B
O
e
PS
w
PS
1000
500
NOTE: OIL POOL DEPTH ASSUMED TO BE AT LEAST 4 IN.
UNDER ALL ENVIRONMENTAL CONDITIONS:
ARBITRARY
PUMP CAPACITY
RECOVERY RATE IN
CALM WATER,
NO CURRENT
TRANSFER
PUMP LIMIT
CHOKING CONDITION
RECOVERY RATE IN
SEA STATE 4, 2 KT
CURRENT
10
No. 1 &
No. 2
FUEL
OIL
100 1000
VISCOSITY (CENTISTOKES)
CRUDE OILS, T > 28°
No. 3 & No. 4 FUEL OILS, T > 28*F
10,000
No. 5 & No. 6 FUEL OILS,
T > 50" F ^
MEDIUM -TO -HEAVY
EMULSIONS
Figure 25: Recovery Effectiveness
-------
354 PHYSICAL REMOVAL . .
Figure 9: 24-In. Device Under Way at 17 rpm, No Waves
-------
LOCKHEED RECOVERY DEVICE 355
1
Q - Oil Recovery Rate
»
3
;i
0
xperimental a~
f both sidqs
1
vt
"y
ji
•age
Q(40) 4-
2
1-.5
1.-C
3'f — ^'
Wiped Side
of Disc
\
)
s
a
c
^
^
/
^
f
A
If
>
K
f
/
'
>-
^f
f
^
"'F
i*/
^
^
i
^
s
'}
>
i i i
DISC"
w*
1
-30
-20
1O 0 TO
- Heel Angle - degrees
20
30
Figure 10: Experimental Oil Recovery Rate of One Side of a 60-In.
Diameter Disc as a Function of Heel Angle
-------
356 PHYSICAL REMOVAI
Operational Capabilities
The operational capabilities of a full-scale 8-ft-diameter
by 10-ft-long system can be determined from the foregoing
analysis. Figure 23 shows a sketch of the recovery system in
use with a containment boom. The containment boom
concentrates the oil into a stagnant pool where it must flow
toward the oil recovery.system. The flow rate is gravity and
inertia-limited, as shown in Fig. 2 for different
specific-gravity oils. The required pool thickness is between
1 and 4 in. for current speeds up to 2 kts, depending upon
the oil specific gravity and sea state. Using Eq. (2) to
calculate the thickness variation as a function of distance
from the boom apex, assuming there is 1 ft of oil in the
thickest part of the pool, shows that 3 in. of 0.95
specific-gravity oil are available at about 30 ft from the
boom apex in a 2-kt current. In a 1-kt current, the oil will
reach out 120 ft. For oils with a lower specific gravity
(lower viscosity), the required thickness to achieve the
predicted recovery rate decreases according to Fig. 2.
Likewise, 4 in. of oil is available SO ft from the boom apex
tor O.57-specitic-gravity oil in a 2-kt current. In a 1-kt
current, the oil will reach out 200 ft. For oils with a higher
specific gravity (high viscosity), the required thickness
remains at about 3 in., because the predicted recovery rate
decreases and less oil is needed to feed the device.
Since both the recovery system and the containment
boom will be loosely moored to have an essential quick
heave response to steep waves, they will also be subject to
reasonably large lateral excursions. Assuming they are
structurally and dynamically independent of each other, 20
to 45 feet of sea room seems a practical requirement
depending on sea state. Eventually, the barrier may fail to
hold a sufficient quantity of high-specific-gravity oil in a
current. Of course, these conditions are somewhat relaxed
at lower current speeds because the quantity of oil varies
inversely with the square of the current speed. Likewise, "
the containment boom and recovery system could be
moved in the current to reduce the relative speed.
The effect of current on recovery effectiveness and
efficiency was not directly tested. It was assumed
conservative to equate the effect of current with the test
results from moving the device through the water. If
sufficient oil is presented to the device, the recovery rate of
low viscosity oil is about 500 gpm for current speeds
between 0 and 2 kts. For high viscosity oils, Fig. 12 shows
the increase and the imposition of choking. The assumed
full-scale system would have 50 discs so its performance
would be 50-fold that of Fig. 12. A concept general
arrangement of a full-scale system is shown in Fig. 24.
The oil recovery system's net oil (and natural
emulsion) recovery rate capability is shown in Fig. 25 as a
function of viscosity. Viscosity is the most important oil
property that affects performance of the recovery
subsystem. In a similar, but not directly related sense,
specific gravity is the most important ofl property that
affects containment boom performance. The graph in Fig.
25 shows most of the other limitations on system
performance. The bottom of left-hand band shows the
variation in performance due to combined severe Sea State
4 and 2-kt current. The right-hand limit shows the effect of
viscous choking at both the disc-vane entrance passages and
the internal wipers. It should be recalled that this limit is
not absolute.
Between these limits there is a cutoff due to the
arbitrary sizing of the oil transfer pump and its prime
mover engine. By following the pump capacity curve to the
lower viscosity region, it can be seen that in heavy seas,
when recovery efficiency drops, the recovery rate also
drops and the pump may be operated at down to 1 /6 of its
rated capacity to minimize its tendency to emulsify. Within
these limits, the recovery efficiency exceeds 75 percent.
Also shown in Fig. 25 is the viscosity for typical oils.
Within the selected recovery device rotational speed range,
the type of oil recovered does not appear to influence the
recovery rate. It was assumed that the containment boom
provides sufficient oil to naturally flow by the
gravity-inertia mechanism to the recovery system at a rate
that supports the recovery capability. For specific gravities
up to 0.99, a 4-in. thickness is sufficient to feed at the
shown rates. A lesser quantity, down to 1/2 in. is required
with specific gravities down to 0.85 when following the
curve from the peak point all of the way to the left. If the
device is presented free oil in a current, the oil depth only
needs to be 1/2 in. to allow the recovery system to reach
maximum capacity without regard to specific gravity. For
thinner layers of oil down to 0.01 in., the recovery device
retains its effectiveness at a constant rate that is
proportional to the oil encounter rate.
REFERENCES
1. B. Bruch, K.R. Maxwell, and H.G. Ulbrich,
"Engineering Concept Evaluation Program for High Seas Oil
Spill Recovery," ORD, Report No. 71403-A-004, Dec.
1970.
2. J.A. Fay, 'The Spread of Oil Slicks on a Calm Sea,"
p. 53 in Oil on the Sea, DP. Hoult, ed. Plenum Press, N.Y.,
1969.
3. DP. Hoult, "Containment and Collection Devices
for Oil Slicks," Oil on the Sea, DP. Hoult, ed. Plenum
Press, New York, N.Y., 1969, pp 65-80
4. DP. Hoult, "Containment of Oil Spills by Physical
and Air Barriers," Paper No. 176, Third Joint Meeting
Institute de Ingenieros Quimicos De Puerto Rico and
American Institute of Chemical Engineers, San Juan, Puerto
Rico, May 17-20,1970.
5. R.A. Cochran, W.T. Jones, and JP. Oxenham, "A
Feasibility Study of the Use of the Oleophilic Belt Oil
Scrubber," USCG Final Report (Contract
DOT-CG-00593-A), Oct 1970.
-------
THE DEVELOPMENT OF TEST PROCEDURES
FOR THE ASSESSMENT OF EFFICIENCY
IN BEACH CLEANING
P. G. Jeffery
Warren Spring Laboratory
Department of Trade and Industry
United Kingdom
ABSTRACT
A bewildering variety of materials has been suggested for
the removal of spilt oil from beaches, rocks and shore-line
structures. These vary considerably in composition, toxic-
ity, efficiency and cost. Early laboratory test procedures
developed in 1961, were concerned only with efficiency in
cleaning and were demonstrably non-reproducible. Since
that date considerable efforts have been made to refine the
procedures in use, and to introduce new tests closely allied
to the beach cleaning process.
A co-operative exercise, undertaken in con/unction with
the maljor oil companies of the United Kingdom demon-
strated the degree of agreement between laboratories that
could be expected from such standardized test procedures.
Recent developments in this field at Warren Spring Labora-
tory, and the procedure at present used for the assessment
of these materials for beach cleaning in the United
Kingdom are described.
INTRODUCTION
There is no completely adequate procedure that can be
used to assess the overall efficiency of materials proposed
for beach cleaning. This stems partly from the variation in
character of beaches, and partly from the wide variety of
conditions (e.g., slope, drainage, tidal action, intertidal
scouring etc.) existing on beaches for which cleaning is
necessary, and fow which the test procedure must be
designed to simulate.
Tests involving the laying down of oiled strips on
beaches are seldom satisfactory, in that such experiments
are not repeatable from one tide to the next, and cannot be
equated to experiments made on other beaches or under
different conditions. In practice this leads to the impossibil-
ity of making fair comparison between one experiment and
the succeeding one and hence between one material and
another.
It has also proved difficult to reproduce laboratory tests
but in practice a fair assessment of any new material
suggested for beach cleaning can be made using the
laboratory test procedures developed, provided that they
are backed by general experience in the use of laboratory
evaluation of such materials. This background experience is
essential to enable a differentiation to be made between
measured properties that are relevant to the requirement,
and those that are not.
This paper has been written not only to summarize the
work that has lead up to the present new test procedure,
but also to describe some of the work undertaken to
evaluate other possible test procedures. It is hoped that the
paper will prevent other workers in this field from
following blind alleys which were found during the course
of the work.
The Preliminary Work
The development of full scale procedures for the
cleaning of the beaches of the United Kingdom started in
1961. In the early stages, it was realized that some
laboratory method would be required for comparing one
dispersing material with another. The first test methods
developed closely followed the large-scale practice that was
then being developed, namely, the elution of oil from a
section of a shingle beach. The oil chosen for this purpose
was a heavy fuel oil, Bunker C, with a Redwood viscosity of
about 4,000. This oil was selected as being a reasonably
uniform, readily available commercial product frequently
spilt and representing something rather more difficult to
clean than the lighter crudes, but a good deal easier than
the tarry lumps which were not acted upon at all by the
357
-------
358 PHYSICAL REMOVAL ...
dispersants. It proved to be a convenient oil to handle
gravimetrically. The first determinations were made by
weighing the residue remaining after oil which had been
eluted from the shingle beach section with sea water was
recovered by solvent extraction using benzene. The oil
fraction remaining on the beach section was similarly
recovered by solvent extraction using benzene. The oil
fraction remaining on the beach section was similarly
recovered using benzene, the solvent being removed and the
oil weighed. Unfortunately it was not possible to get
reproducible results from this simple test procedure. This
was shown to be due in some measure to the difficulties of
eluting the oil from the heterogeneous shingle bed. In
particular it was realized that variation in size and shape of
the inter-particle space was resulting in erratic hold-up.
Other points noted in these initial studies were the need for
uniform wetting of the bed with salt water and the need for
greater uniformity in the method of treating the deposited
oil with solvent emulsifier.
The Cleaning of Flat Surfaces
At this stage it was considered vital to re-examine the
fundamental premise behind the test (i.e., that the proce-
dure used should be a scaled-down version of large-scale
practice) to try to find an alternative method that would be
more reproducible, yet at the same time give results directly
applicable to beach-cleaning practice.
It was argued that since many beaches are composed of
or contain quite large pebbles, a useful test procedure could
be one based upon the cleaning of a single test pebble, or its
equivalent, in the laboratory. A number of test surfaces
were therefore examined, including concrete, tile, bricks of
various porosities, various metal surfaces, sand-blasted glass
plates and natural pebbles of several kinds. Each surface
was oiled, sprayed with solvent emulsifier and then washed
down with sea water.
In general it was found that the surfaces were of two
kinds, those that were cleaned far too easily to give any
measure of the cleaning efficiency of the emulsifier, and
those including all surfaces of high porosity, that proved
impossible to clean. An added difficulty was the virtual
impossibility of measuring the quantities of solvent/emulsi-
fier .mixture used, particularly in relation to coverage of
the oiled plates or surfaces.
This type of test procedure was therefore abandoned for
beach cleaners, although subsequent work using a porous
plate has since led to the development of a suitable test
method for gels and pastes which are designed to clean oil
and tar products from road surfaces, concrete and brick-
work.
The "Model Beach" Test
This is the test procedure that has been in continuous
use since 1967, and is described in some detail by Beynon
at the Joint Symposium organized in 1969 by the American
Petroleum Institute and the then Federal Water Pollution
Control Administration.
In this procedure, the earlier shingle beach was replaced
by a uniform bed of cleaned, Ballotini glass spheres
approximately equating to coarse sand in particle size. This
provided a uniform bed with a slightly dished surface which
could be wetted with sea water, have standard amounts of a
bunker oil and of solvent/emulsifier added to it, and then
be eluted with sea water. The efficiency of cleaning was
measured by recovering both the oil eluted from the model
beach and that remaining in the test bed, for a number of
oil/emulsifier ratios.
For the determination of oil, the recovered fractions
were diluted to volume in a halocarbon solvent and
measured spectrophotometrically. This in itself is not a
simple process as turbidities sometimes develop in the
chloroform solutions, vitiating the measurement. Chloro-
form solutions of oil must not be exposed to sunlight, nor
for prolonged periods to strong daylight. Even so, the
combined totals for oil in the two samples usually exceeds
the original oil added by a small amount. This in itself is
not of importance, as this small amount is well within the
variations experienced in using this method. Some of this
excessive total is due to the color of the dispersant mixture
under test.
In the hands of a skilled operator, this test procedure
gives results that are reproducible to ±20 per cent. Graphs
of typical results are shown in Figure 1, together with brief
comments by way of interpretation. It is only with
difficulty that these results can be used to compare two
dissimilar materials quantitatively, but they can easily and
simply to interpreted visually by a straightforward compari-
son with those materials known to be effective as beach
cleaners.
30
i
10
1 I '
A. POOR BEACH CLEANER,
UNABLE TO PENETRATE OIL
B. GOOD BEACH CLEANER
C EXCELLENT BEACH CLEANER,
HIGH N AROMATIC SOLV
1=5 2:5
RATIO OF BEACH CLEANER TO OIL
Figure 1: Results From "Model Beach" Test
3:5
-------
...EFFICIENCY IN BEACH CLEANING 359
Unfortunately this test procedure gives erratic results in
unskilled hands, and this is exemplified by the remarks of
Beynon concerning an inter-laboratory co-operative test
program. A total of six laboratories were asked to use this
procedure for assessing the beach cleaning efficiency of
seven commercially available dispersants. The results he
quotes for a second co-operative test program show that
this model beach test procedure is unsuited as it stands for
standarization. All that can reasonably be claimed from this
exercise is that dispersants known to be poor for beach
cleaning were shown to be poor at cleaning the model
beach, while conversely, dispersants which were good for
beach cleaning also cleaned the model beach.
However no two laboratories ranked the seven materials
in the same order, and one laboratory rated a particularly
poor cleaner higher than another laboratory rated a good
one.
Developments of the "Model Beach" Test
As a preliminary exercise toward the development of a
modified test procedure, an examination was made of the
likely causes of variation of results from one laboratory and
another. Particular attention was paid to the spectrophoto-
metric method of measurement, as considerable differences
in technique were discovered between the co-operating
analysts. However these differences were, on examination,
not found to be capable of explaining the vast differences
in the results that had earlier been obtained.
The following observations, explaining the differences
noted in the laboratory and believed to be responsible for
the lack of repeatability within a single laboratory, were
finally selected as explaining the major part of the
inter-laboratory variation:
(a) the bunker oil used in this test does not spread over
the glass beads in a uniform manner. The spread is
greater on some occasions than on others, and there
is variation in the depth of penetration of the beads.
(b) the solvent/emulsifier mixture does not 'react' with
the oil on the glass beads in a uniform manner. It is
to be expected that different emulsifiers would
behave differently, but on occasions the same
emulsifier follows a different pattern. To some
extent this is a result of (a) above, but in addition
the rate of adsorption of the emulsifier into the bead
bed is sometimes so rapid that a part of it escapes
contact with the oil.
(c) owing to channelling within the bead column, some
of the water used is not effective in leaching the
emulsified oil. With some emulsifiers, the dilution of
the oil with the contained solvent enables globules
of unemulsified oil to be eluted mechanically. To
avoid these differences, that could give rise to a
considerable variation of results, a number of
changes were introduced. The test bed of glass beads
was reduced considerably in diameter, and length-
ened somewhat to give a narrow longish column.
The bead diameter was reduced considerably. These
two changes between them restricted the amount of
channelling through the beads, gave a better control
over the flow rate of fluid through the column, and
prevented the mechanical elution of globules of
diluted (as distinct from emulsified) oil.
Other changes introduced included the use of
glass beads previously treated with oil, and the use
of methanol to elute water, salt and emulsifier from
the column, prior to eluting the oil with halocarbon
solvent.
These changes gave a new procedure which at
least within my own laboratory proved to be a great
deal more reproducible than the earlier ones. Unfor-
tunately the behavior of solvent/emulsifier mixtures
in the test has since been shown to bear no relation
to the behavior of the solvent/emulsifier mixture in
large-scale beach cleaning. For many materials, the
test gave a measure of the amount of emulsifying
constituent present (i.e., the surface active material)
and no indication at all of the penetrating power of
the solvent fraction, nor of the ability of the solvent
to make available the emulsifying constituent.
Recent Developments
In these developments, attempts have been made in the
test procedure to approximate more closely to conditions
prevailing on a beach. The use of pre-treated oily beads has
been retained, but they are no longer supported in a glass
column. A larger volume of beads is taken and the
solvent/emulsifier mixture added using a syringe with a
hypodermic needle. After allowing the test bed to stand for
a fixed period of time, a known volume of sea water is
added, and the beaker and contents are transferred to a
shaking table which is set in motion at such a speed that the
glass beads are gently agitated, but are not actually swirled
around the beaker.
In this action the oil is liberated and emulsified. The
aqueous phase containing the emulsified oil is decanted and
the oil recovered by halocarbon extraction. Oil remaining
on the surface of the beads is recovered by washing with
chloroform. Both samples of oil are examined spectro-
photometrically in the usual way.
The advantages claimed for this procedure are as
follows:
(a) as the oil is present in a thin surface layer
only, it cannot be detached mechanically in
the form of large droplets;
(b) the solvent itself has a diluting effect in the
test procedure, which parallels that obtained
in practice; and
-------
360 PHYSICAL REMOVAL ...
(c) the motion of the shaking table simulates the
wave aciton that takes place on natural
beaches.
This test procedure is still under evaluation, but prelimi-
nary results are encouraging. Whether they remain as
encouraging when the test is in the hands of operators
unskilled in this kind of testwork remains to be seen.
APPENDIX I
A Beach Cleaning Efficiency Test for
Solvent Emulsifiers and
Other Detergent Materials
In this test procedure, a measured volume of dispersant
is spread on to an oiled "beach" of glass balls. Sea water is
added, and the "beach" gently agitated for 15 minutes. The
oil that is removed from the "beach," and also that
remaining on the glass beads, is determined spectrophoto-
metrically.
MATERIALS REQUIRED
Apparatus
Syringe pipettes, 2-ml and 10-ml capacity.
BaJlotini solid glass spheres, 16-25 mesh.
Spectrophotometer, with 0.5 cm cells.
Separating funnels, 250-ml.
Beakers, 250-ml and 600-ml.
Measuring cylinder, 100-ml.
Clock glass, 5-cm diameter, with a 15-cm glass rod
cemented to the concave surface.
Volumetric flasks, 100-ml.
Hotplate
Filter funnel, 15-cm.
Filter papers, Whatman No. 1,9-cm.
Shaking table, a shaking table capable of imparting a
rotating motion of up to 120 r.p.m. to a deck
modified to hold up to 10 250-ml beakers.
Reagents
CMoroform
Sea water, synthetic sea water prepared from "Sea Water
Corrosion Test Tablets".
Test oil, topped Kuwait crude oil.
PROCEDURE
Switch on the shaking table and set to a speed of about
120 r.pjn.
Weigh 500 g of Ballotini solid glass spheres into a 600-ml
beaker and, using a syringe pipette, add exactly 10 ml of
topped crude ofl. Stir the beads thoroughly to obtain
complete mixing and uniformly coated beads.
Transfer 50 g of the oiled beads to a 250-ml beaker, and,
using the clock galss with the glass rod cemented to it, press
down on the beads to give a slightly concave surface.
Using the smaller of the two syringe pipettes, add 0.2 ml
of the beach cleaner under test. A fine needle should be
used to ensure an even distribution of solvent/emulsifier
mixture over the concave surface of the test bed. Allow the
cleaner to soak into the bed for 15 minutes, then add 100
ml of sea water by gently pouring down the side of the
beaker so as not to disturb the beads. Place the beaker on
the shaking table and shake for 15 minutes. The table speed
should be adjusted to impart a swirling motion to the sea
water and a gentle agitation to the glass beads.
Remove the beaker from the table and decant the liquid
fraction into a 250-ml separating funnel. Wash the beads
with two 25-ml portions of sea water, adding the washings
to the liquid fraction in the separating funnel.
Extract the oil from the aqueous/emulsifier oil fraction
by shaking with five 15-ml portions of chloroform, col-
lecting the chloroform extracts in a 100-ml volumetric
flask. Dilute the chloroform solution to volume and
determine the oil content by spectrophotometric measure-
ment at 580 run in the usual way (Note 1).
Rine the oiled beads remaining in the beaker with suc-
cessive small portions of chloroform and collect the
combined organic solution in a 100-ml volumetric flask,
also for spectrophotometric measurement at 580 nm in the
usual way (Note 2).
Using a calibration graph, calculate the oil removed from
the "beach" as a percentage of total oil recovered (Note 3),
and plot these values against the ratio of oil to beach
cleaner (Note 4).
CALIBRATION
Using a syringe pipette, measure three 0.8 ml volumes of
topped crude oil into three separate beakers. Dissolve each
portion of ofl in chloroform, transfer to separate 100-ml
volumetric flasks and dilute each to the mark. Measure the
absorbance at 580 mm and calculate a factor for converting
absorbance readings to volumes of oil. Take an average of
the three factors obtained.
TIMING
A totla of five tests in one series can be undertaken
concurrently. The time taken is approximately 2% hours.
NOTES
1. The chloroform solution should be perfectly clear
and remain so. If clouding occurs this may be
removed by filtration through a small filter paper, or
by gentle boiling for a few minutes, allowing to cool
and diluting once again to volume.
2. The amount of oil remaining on the "beach" cannot
be calculated by differences, as the amount of oil
taken varies slightly from one test to the next.
3. This ratio technique is necessary as some beach
cleaners at present available have appreciable optical
densities at 580 nm, leading to apparently high
recoveries of oil.
4. Suitable ratios of oil to beach cleaner are 5:1, 5:2,
5:3,5:4 and 5:5.
-------
INVESTIGATION OF THE USE OF A
VORTEX FLOW TO SEPARATE OIL
FROM AN OIL-WATER MIXTURE
Arthur E. Mensing and Richard C. Stoeffler,
United Aircraft Research Laboratories
East Hartford, Connecticut
ABSTRACT
The use of a continuous-flow vortex separator as a
component of an oil spill clean-up system was investigated.
Tangential injection of the oil-water mixture into the
vortex tube produces buoyant forces which accelerate the
lighter oil to the vortex axis. The cleansed water and the
core containing the oil are exhausted through exit ports in
opposite end walls of the vortex tube. The cleansed water
would be returned to the sea and the core flow containing
the oil would be stored.
Tests of laboratory-scale model vortex separators were
made using oil-water mixtures having inlet oil-to-total-flow
ratios between 0.002 and 0.3 and for a variety of geometric
and flow conditions. The tests were made using four types
of oil (napthene-base crude, paraffin-base crude, dieseland
No. 6 heating fuel) having viscosities between 3 and 4250
cps (measured at 75 F) and specific gravities between 0.83
and 0.97. The results showed that separator performance
may be optimized by proper control of the oil exhaust
flow. Under optimum conditions, approximately 90
percent of the injected oil was separated and captured, and
the captured flow contained approximately 90 percent oil.
Studies were also made to determine the sizes and
weights of components for full-scale vortex separators,
including the necessary pumps and prime movers.
INTRODUCTION
An oil-water separator which operates on-line and
processes large volume flow rates of an oil-water mixture
may be a required component in many oil-spill clean-up
systems. The use of a confined vortex flow appears to be a
desirable separation method because it provides large
relative radial accelerations between two components
having differing specific gravities. Thus, the oil is
accelerated radially inward at a greater rate than the water
and is concentrated at the center where it can be
conveniently removed. A vortex separator is simple,
requires no rotation of a large mass (such as a centrifuge),
and can handle large flow rates in a relatively small volume.
However, a pressure drop exists across the vortex, and a
pump must be provided to increase the pressure of the
incoming oil-water mixture.
The objectives of this study were: (1) to conduct
small-scale laboratory tests to evaluate feasibility and (2) to
define the components that are required for a full-scale
separator. The tests included investigation of some of the
effects of geometry, oil properties, and oil and water flow
rates on performance, i.e., (1) the fraction of the incoming
oil that is separated and removed from the separator (the
separator effectiveness) and (2) the oil fraction of the fluid
withdrawn through the oil exit (the separator efficiency). It
is desirable not only to remove most of the oil injected into
the separator, but also to remove this oil in a relatively
water-free condition to minimize the oil storage volume
required.
VORTEX THEORY
The radial acceleration of fluid in a vortex is balanced
by the radial pressure gradient. In a vortex containing small
amounts of oil, the radial pressure gradient is determined
by the radial acceleration of the water; thus, there is a net
force on the lighter oil accelerating the oil particles radially
inward. The radial acceleration difference between the oil
and the water is
pw-Po
(1)
*This program was supported in part undei Contract DOT-
CG-00546-A with U.S. Coast Guard Headquarters, Washing
ton, D.C., 20591.
361
-------
362 PHYSICAL REMOVAI
The radial variation of the acceleration difference is shown
in Fig. 1 (oil specific gravity of 0.9). Curves are presented
for two different vortex radii (0.417 ft and 5.0 ft), and for
several values of the tangential velocity, V * j, at the
peripheral wall.
The pressure drop across the vortex can be calculated
by integrating the radial mometum equation:
2
r - g r (2)
For a vortex in which W is inversely proportioned to r,
integration of Eq. (2) between the peripheral wall of the
vortex, r,, and the radius of the exit port, re, gives the
pressure difference across the vortex, AP:
(2)
AP =
-1
(3)
g
Calculations using Eq. (3) were performed with n/re = 5.0
and the results are presented in Fig. 2. The pressure drop
across the vortex is independent of the vortex diameter, but
is dependent on the tangential velocity at the peripheral
wall. Figures 1 and 2 indicate that large radial accelerations
of the oil particles can be obtained with pressure drops
across the vortex generally less than 1.5 atm.
TEST EQUIPMENT
The laboratory model tests were conducted using three
different separators: lO-in.-dia by 29.25-in.-long, 10-in.-dia
by 15-in.-long, and 54n.-dia by 15-in.-long. The flow system
employed is shown schematically in Fig. 3. The oil is stored
in an 80-gal pressure vessel and flows through a throttling
valve and a flowmeter prior to being injected into the
incoming water stream. The oil and water are well mixed
before being injected into the separator. The outflow from
the separator (both ofl and water) enters a 1000-gal storage
tank where the oil-water mixture is quiescent for
approximately 12 hours, permitting the oil and water to
separate. The water is then drained from the bottom of the
tank.
Four types of oil were employed: a napthene-base
crude oil, a paraffin-base crude ofl, a No. 6 fuel ofl and a
diesel fuel. These were chosen to provide a range of specific
gravities and viscosities (see Table I for the measured
properties). The maximum ofl flow rate possible with the
system shown in Fig. 3 was approximately 5 gpm. Thus,
maximum inlet ofl concentrations of 12 and 30 percent
could be obtained in the lO-in.-dia and 5-in.-dia separators,
respectively.
A sketch of the separator is shown in Fig. 4. The
oil-water mixture was injected in a tangential direction
through a series of ducts located near the periphery of one
end wall. The injection configuration in the lO-in.-dia
separator consisted of six 0.88-in.-ID ducts and four
0.38-in.ID ducts in the 5-in.-dia separator. The water was
withdrawn through a part at the center of the opposite end
wall. The exit port diameter was 20 percent of the
separator diameter. A core plate with a diameter half that
of the exit port was located on the vortex centerline at the
water exhaust end (see Fig. 4). The core plate provides a
space for the storage of separated ofl within the vortex and
prevents the oil from being swept out with the exhausting
water. The oil was removed through a small duct located at
the center of the end wall containing the injectors. A
photograph of the separator is shown in Fig. 5 operating
with an inlet oil concentration of approximately 2 percent.
The dark region in the center of the vortex is the ofl core.
100
50
20
10
•c
m 5
| 2
< 1
_j
5 0.5
z
III
I 0.2
£ 0.1
•0.05
5 0.02
" 0.01
0.005
0.002
0.001
LINE
V"
0.417
5.0
- \
0.2 0.4 0.6 0.8
RADIUS RATIO, r/r,
1.0
Figure 1. Radial Acceleration Difference Between Oil and Water
-------
THE USE OF A VORTEX FLOW... 363
8 100
O« 50
u. 10
°
0
£5 2
°
0.2
0.1
0 2 4 6 8 10 12
TANGENTIAL VELOCITY AT
PERIPHERAL WALL, V«,-FT/SEC
Figure 2. Pressure Difference Across Vortex
Test Procedures
The primary purposes of the vortex oil-water
separation experiments were to determine the separator
effectiveness (i.e., the fraction of incoming oil that could be
captured and removed through the oil exhaust duct) and
the separator efficiency (i.e., that fraction of the flow
removed through the oil exhaust duct that was oil). The
test procedures were: (1) the water and oil flow rates were
set to provide a given incoming oil-water mixture; (2) the
flow into the storage tank was throttled to maintain a given
pressure at the vortex centerline; (3) when steady-state
conditions existed, a sample of the flow exhausting from oil
exhaust duct was taken; (4) both the volume of the sample
(sample sizes ranged, from approximately 100 ml to 1000
ml) and the time to take the sample were measured; (5) the
samples were allowed to remain quiescent until the oil and
water in the sample had separated. The oil fraction of the
sample was measured and the separator efficiency was
determined. The volume of the oil in the sample and the
time required to collect the sample were used to determine
the flow rate of the captured oil. The effectiveness of the
separator was determined from the ratio of the captured oil
flow rate to the flow rate of the incoming oil. Several
checks were made on the specific gravity of the captured oil
to insure that no water was emulsified in the captured oil.
FROM WATER
MAIN
H.OW-
METER
Oil
FLOW
METER
-u
FROM ^CYLINDER RESULTS OF VORTEX SEPARATOR TESTS
I SO GAL OIL
I STORAGE TANK
d
VORTEX
SEPARATOR
h— OIL EXHAUST
WATER EXHAUST
TO DRAIN
Figure 3. Schematic of Piping System for Vortex Separator
OIL EXHAUST DUCT-
-EXHAUST DUCT
END WALL INJECTORS -
SECTION A-A
SECTION B-B
Figure 4. Vortex Separator With End-Wall Injection
Tests were conducted with the three different oil-water
separators over a wide range of conditions to determine the
variations of the separator effectiveness and the separator
efficiency with inlet oil-to-total-flow ratio. It is desirable
that both the separator effectiveness, Es, and the separator
efficiency, r?s , be close to one. If the separator
effectiveness was 1.0, all the incoming oil would be
recovered and only water would be exhausted. If the
separator efficiency was 1.0, only pure oil would be
exhausted through the oil exhaust port. It is also desirable
that Es and TJS be insensitive to the inlet oil-to-total-flow
ratio, Oi, since it appears unlikely that Oi will be constant
in the flow supplied to the separator.
Results of lO-in.-dia Vortex Separator Tests
Tests of the lO-in.-dia by 29.25-in.-long separator were
conducted using each of four different types of oil listed in
Table I. The injected water flow rate was maintained
constant at 48 gpm, the pressure at the vortex center was 7
psig, the pressure drop across the vortex was approximately
3 psi, and the injection velocity of the oil-water mixture
was 4.3 ft/sec. The oil was removed through a 0.19-in.-dia
port in the end wall containing the injectors, and the
pressure in the oil exit duct was atmospheric. Tests were
conducted throughout a range of inlet oil-to-total-flow
ratios, Oj, from approximately 0.002 to 0.12.
The variation of the separator effectiveness, Es, with
inlet oil-to-total-flow ratio is shown in Fig. 6(a). In the tests
conducted with the No. 6 fuel oil, napthene-base crude oil,
and the diesel oil, samples collected from the oil exhaust
duct consisted of water and whatever type of oil was
-------
364 PHYSICAL REMOVAL .
injected. In tests with the paraffin-base crude oil,the sample
consisted of water, oil, and a third substance (mostly
paraffin) having a specific gravity of 0.95. There appeared
to be a small amount of oil trapped within the paraffin. The
paraffin was not included as oil captured in results
presented in Fig. 6(a) because the fraction of oil being
converted to this fluid was not known. The results for the
paraffin-base crude then are conservative.
Figure 5. Photograph of Vortex Separator in Operation
In the range of inlet oil-to-total-flow ratios between
0.002 and 0.02, visual observation indicated a small
instability in the oil core. For this range of Oj, the oil core
diameter increases as Oj increases until the oil core reaches
the approximate diameter of the core plate. The instability
appears to be associated with a very small oil core and may
account for the reduced and somewhat erratic behavior of
the separator effectiveness within this range of Oj.
(Operation of this particular separator with Oj less than
approximately 0.02 is undersirable because of low values of
separator efficiency.) For this configuration, separator
effectiveness reached a maximum value of approximately
0.80 with Oj equal to approximately 0.02. Increasing Oj
beyond 0.02 resulted in a decrease in effectiveness because
more oil was injected into the separator than could be
exhausted through the oil exhaust port. Increasing the
pressure or increasing the area of the oil exhaust port is
necessary if the effectiveness is to be increased at larger
values of Oj.
The variation of the separator efficiency, TJS, with
inlet oil-to-total-flow ratio is shown in Fig. 6(b). The
efficiency increases rapidly as Oj is increased to
approximately 0.02. At larger values of Oj, the efficiency
remains nearly constant or increased very slightly. For this
particular configuration, the efficiency at values of Oj
greater than 0.02 was about 0.8 (higher for the
napthene-base crude) and has reached the maximum value
for the g^en geometry.
SYMBOL
D
A
o
0
TYPE OF Oil
DIESEL
CRUDE-
PARAFFIN BASE
CRUDE-
NAPHTHENE BASE
NO. 6 FUEL OIL
(a) SEPARATOR EFFECTIVENESS
J 1.05-
0.02 0.04 0.06 0.08 0.10 0.12
(b) SEPARATOR EFFICIENCY
0 0.02 0.04 0.06 0.08 0.10 012
INLET OIL-TO-TOTAUFLOW RATIO, O;
Figure 6. Performance of 10-Inch-Diameter Separator for Four
Types of Oil
The data presented in Fig. 6 indicate that, for the
particular geometry tested, the maximum values of
separator effectiveness and efficiency would be obtained
under test conditions in which Oj was approximately equal
to 0.02. For Oj greater than 0.02, the oil removal rate is less
than the incoming oil flow rate, thus causing the separator
efficiency to remain nearly constant and the effectiveness
to decrease. Conversely, at values of Oj less than 0.02 most
of the inlet oil is captured (the separator effectiveness is
large), but a substantial amount of water is captured with
the oil (a low efficiency). Neither oil viscosity nor the oil
speicifc gravity had much effect on the separator
performance.
Performance data were also obtained at various inlet
water flow rates (Qw = 31,48,and 96 gpm). For these tests
the napthene-base crude oil was used. The pressure drops
across the vortex were approximately 2, 3, and 13 psi for
flow rates of 31, 48, and 96 gpm, respectively. The
variations of the separator effectiveness and efficiency with
inlet-oil-to-total-flow ratio are presented in Fig. 7. The
optimum separator performance when operated at both 31
gpm and 48 gpm are comparable - the effectiveness and
efficiencies are greater than approximately 0.85. However,
-------
THE USE OF A VORTEX FLOW ...
365
the value of Oj at which the optimum performance occurs
is different for the two flow rates. If the data were
presented with ofl flow'rate as the abscissa instead of inlet
oil-to-total-flow ratio, the optimum performance would
occur at approximately the same value.
The data in Fig. 7 indicate that the separator
effectiveness for a water flow rate of 96 gpm was less than
at 31 and 48 gpm. As the water flow rate is increased, the
residence time of the flow within the vortex separator is
decreased and less time is available for the ofl to be driven
to the core (an average residence time can be defined as the
separator volume divided by the volumetric flow rate, Qw).
The decreased residence time may explain the decrease in
separator effectiveness at Qw = 96 gpm. The average
residence time for flow in the separator is 20,12, and 6 sec
for Qw = 31,48, and 96 gpm, respectively.
Performance data were also obtained with different
separator lengths. The 104n.-dia separator was used with
lengths of 29.25 in. and 15 in. The oil (naphthene-base
crude) was again exhausted through a 0.19-in.-dia exhaust
duct in the injector end wall. Water flow rate was
maintained constant at 48 gpm. As shown in Fig. 8(a), the
maximum value of effectiveness was greater for the 15-in.
length than for the 29.25-in. length. Efficiency (Fig. 8(b))
was relatively unaffected by length.
Optimum performance appears to depend on the
amount of oil that can be exhausted through the oil
exhaust port. Thus, a separator must incorporate a control
to provide best operation under varying inlet
oil-to-total-flow ratios. This control may be achieved by
varying the area of the oil exhaust port. Preliminary tests
have been conducted using the lO-in.-dia by 15-in.4ong
separator in which the oil exhaust port area was decreased
by positioning a conical centerbody in the exhaust port.
Reducing the area by 16 percent increased both separator
effectiveness and efficiency when Oj was 0.015. Similarly,
further reduction in the oil exhaust port area to 64 percent
of its original value increased the separator performance at
Oj of 0.01. Thus, a variable-area oil exhaust port could
provide optimum separator performance throughout a
range of inlet oil-to-total-flow ratios.
Other tests were made with the lO-in.-dia separator to
investigate the effects of certain changes in geometry. Some
were made with injection through a slot along the
peripheral wall in place of the end-wall injectors. In other
tests, no core plate was used. Data obtained using a slot
injector resulted in little or no improvement in the
separator performance. However, removal of the core plate
drastically reduced the performance of the separator and
made it impossible to obtain efficiencies greater than about
15 percent.
5-in.-dia Vortex Separator Tests
Tests which were impractical in the lO-in.-dia separator
were conducted using the 5-in.-dia by 15-in.-long separator.
In one series of tests, performance was determined at inlet
oil-to-total-flow ratios up to 0.3. In other tests, the effect
of external motions (such as might be caused by ship
motions) on performance was determined.
Separator performance data obtained with inlet
oil-to-total-flow ratios up to approximately 0.3 are
presented in Fig. 9. These tests were run with a water flow
rate of 7 gpm and with the naphthene-base crude oil.
Several different oil exhaust port areas were used, as noted
in Fig. 9. The benefits of a variables-area oil exhaust port
are apparent in Fig. 9.
This separator was also tested in an unsteady force
field generated by manually shaking the separator in the
vertical plane (the axis of the separator was horizontal). It
was estimated that the acceleration fluctuated between-0.5
g to plus 2.5 g's at approximately 4 Hz. Test data indicated
that shaking the separator resulted in a decrease in
performance of approximately 10 percent.
SYMBOL
A
0
D
WATER FLOW
RATE, GPM
31
48
96
(a) SEPARATOR EFFECTIVENESS
0.02 0.04 0.06 0.08 0.10
(b) SEPARATOR EFFICIENCY
uj t O 9
"*"
0.02 0.04 0.06 0.08
INLET OIL-TO-TOTAL-FLOW
RATIO, Oj
Figure 7. Performance of 10-Inch-Diameter Separator for Three
Water Flow Rates
-------
366 PHYSICAL REMOVAL...
SYMBOL
a
o
LENGTH.
L-IN.
29.25
IS
(a) SEPARATOR EFFECTIVENESS
Si U
„,- i.o
M ° 8
Z 0.6
ui
0.4
0.2
0
O.02 0.04 0.06 0.08 0.10
(b) SEPARATOR EFFICIENCY
0.02 0.04 0.06 0.08 0.10
INLET OIL-TO-TOTAUFLOW
RATIO, O;
Figure 8. Performance of 10-Inch-Diameter Separator for Two
Vortex Tube Lenghts
Data obtained from tests using the model vortex
separator have shown: (a) the viscosity of the oil has little
or no effect on the separator performance, (2) an average
residence time of approximately 10 sec is required to
obtain good separator performance for ofls having specific
gravities between 0.83 and 0.97, (3) a variable-area ofl
exhaust port is required to optimize separator performance
over a- range of inlet ofl-to-total-flow ratios, (4) good
separator performance has been obtained for inlet
oil-to-total-flow ratios between 0.002 and 0.3, and (5) the
effect of external accelerations on the performance of a
vortes separator is small.
Design Characteristics of a Full-Scale Vortex
Separator System
The application of a vortex separator requires, in
addition to the separator itself, a pump to increase the
pressure of the oil-water mixture and a prime mover for the
pump. A systems analysis was undertaken to determine the
operating characteristics and weights of full-scale vortex
separator systems having flow capabilities from 1000 to
100,000 gpm.
Characteristics of Pumps
A pump is required which will provide a head rise of
approximately 50 ft of water without emulsifying the oil in
the oil-water mixture. Discussions with manufacturers of
large-volume-flow-rate pumps indicated that centrifugal
pumps may induce excessive turbulence that could emulsify
the oil-water mixture. However, three other types of pumps
might be used with full-scale separators: propeller, mixed
flow, and vertical turbine pumps. The vertical turbine pump
is capable of attaining the highest head rise per stage for a
given flow rate and the propeller pump exhibits the lowest
head rise per stage. However, emulsification of the oil-water
mixture is most likely to be encountered with the vertical
turbine pumps. The pumps investigated in this study were
off-the-shelf items and, with few exceptions, the prime
movers for these pumps were electric motors. The pump
power requirements for several flow rates are listed in Table
II.
Weight of Vortex Separator System
The estimated weight of a system, including the
separator itself, the pump and its prime mover, were
determined for flow rates from 1000 gpm to 100,000 gpm.
For these studies the length-to-diameter ratio and average
ITTT««111 JMTT
I IN.
0.125 IN.
0.250 IN.
(a) SEPARATOR EFFECTIVENESS
i.Ol 0.02 0.05 0.10 0.2
0.5 1.0
(b) SEPARATOR EFFICIENCY
1.0
0.6
M
-------
THE USE OF A VORTEX FLOW ... 367
residence time of flow in the separator were 3 and 10 sec,
respectively. The separator was assumed to be fabricated
from commercially available steel. The variation with flow
rate of the weight of the entire system is shown in Fig. 10.
Curves are presented for the combined weight of the pump
and prime mover, the combined weight of the pump, prime
mover and dry vortex separator, and the total weight of the
system including the water that would be contained in the
vortex separator. Also included in Fig. 10 are the weights of
a system which may be realized if advanced components
were used. In this design, the vortex pressure drop would be
reduced from 50 ft of water to approximately 20 ft of
water (this may be possible if a diffuser is used at the
separator exhaust to recover most of the swirl component
of the exhaust velocity). Also, the vortex separator would
be constructed of reinforced^iberglass rather than steel. A
substantial .weight savings of the separator system is
evident.
CONCLUSIONS:
Results of this study have shown that a,confined vortex
flow can be used to separate oil from an oil-water mixture.
Values of separator effectiveness equal to or greater than
0.9 were obtained with separator efficiencies equal to
approximately 0.9. Vortex separator systems which process
large volume flow rates of an oil-water mixture are not
prohibitively large; the average fluid residence time within
the vortex separator is about 10 sec. However, additional
development work on the vortex separator is needed. This
work includes the development of an oil exhaust port area
control and an oil exhaust sensor to provide good separator
performance throughout large variations of inlet oil
concentration. In addition, it may be desirable to
incorporate a vortex diffuser to recover a portion of the
total pressure drop across the vortex and thus minimize the
size and weight of the pump required. Additional
Table 1: Properties of Oils Used in Vortex Separator Tests
Type of Oil
Naphthene-Base Crude
Paraffin-Base Crude
Diesel Fuel
No. 6 Fuel
Specific Gravity
@ 75 deg F
0.90
0.83'
0.84
0.97
Viscosity @ 75 deg F
cps
79
3.2
3.0
4250
SUS
360
40
37
20,000
10
FLOW RATE,GPM
Figure 10. Weight of Vortex Separator System
investigations are also required to further optimize the
performance of the vortex separator with respect to the
injection velocity of the inlet flow.
Table 2: Pump Power Requirements for 50 Ft. Head Rise
Flow Rate (gpm) Power (hp)
1,000
2,500
5,000
10,000
25,000
50,000
100,000
15
38
75
150
380
750
1,500
List of Symbols
ar j Radial acceleration difference, ft/sec2
D Diameter of vortex separator, in, or ft
Es Separator Effectiveness
g Acceleration of gravity, g = 32.2 ft/sec2
L Length of vortex separator, in.
Oi Inlet oil-to-total-flow ratio, dimensionless
P Pressure in vortex,
-------
368 PHYSICAL REMOVAL ...
Water flow rate, gpm
Radius, ft
Radius of vortex separator, ft
Water exit radius, ft
Tangential velocity in vortex, ft/sec
Po
pw
AP
Tangential velocity at periphery of vortex, ft/sec
Separator efficiency
Density of oil, slugs/ft-*
Density of water, slugs/ft3
Pressure difference across vortex, lb/ft2 or ft of water
-------
"DYNAMIC KEEL" OIL CONTAINMENT
SYSTEM
Frank March
Ocean Systems, Inc.
ABSTRACT
Ocean Systems, Inc., under contract to the U.S. Coast
Guard, has developed an oil containment system for use on
the high seas. The system is designed to contain oil in 4-5
foot seas in combination with 20 mile per hour winds and
ft 7-1 knot currents in a nominal water depth of 200 feet
and up to 30 miles from shore.
The barrier design is based on the use of flexible poly-
urethane foam, with a "dynamic keel" that imparts high
static and dynamic stability. The barrier consists of a
non-water-absorbing foam package that provides buoyancy
and a surface barrier, and a water-absorbing foam package
that provides a submerged barrier and serves as a "dynamic
keel" The two packages are connected into an integral unit
that can be compressed to approximately 20% of the origi-
nal volume for storage and transportation. The memory or
resiliency of the foam material causes the barrier to resume
its original shape and size after the packaging restraints are
released. It should be noted that no compressors, pumps
and other mechanical support equipment are required.
Results of analytical studies and model testing are pre-
sented which indicate the effectiveness of the system.
INTRODUCTION
• Ocean Systems, Incorporated has developed a unique
oil containment system for use on the high seas for the U.S.
Coast Guard, under Contract DOT-CG-00, 489-A during
the period of December 1969 to June 1970. This paper
describes the results of analysis, testing and design of that
system. In. performing this work Ocean Systems, Inc. was
assisted by Union Carbide Corp. Chemicals and Plastics Div.
(material testing) and by the All-American Engineering Co.
(air deployment).
System Objectives
The principal objective of the containment system is to
quickly confine thick films of oil in waves up to five feet
high in combination with 20 mile per hour winds and 2
knot currents*, in a nominal water depth of 200 feet, and
up to 30 miles from shore. In addition, the system must
maintain its physical integrity, though not performing as an
, effective containment device, in seas of 20 feet, winds of 60
miles per hour and currents of 3 knots. To quickly contain
an oil spill, the system must be capable of being deployed
in four hours.
Other salient development requirements have included
compatibility with existing Coast Guard ships, boats and
aircraft; air deployment capability; high reliability; low
maintenance requirements; and the ability to survive in the
aforementioned environment for a period of several weeks.
Design Concept
The barrier concept is based on the use of flexible
polyurethane foam, with a "dynamic keel" that imparts
high static and dynamic stability. The barrier consists of a
non-water-absorbing foam package that provides a sub-
merged barrier and serves as a "dynamic keel". The two
packages are connected into an integral unit that can be
compressed to approximately 20% of the original volume
for storage and transportation. The memory or resiliency of
the foam material causes the barrier to resume its original
shape and size after the packaging restraints are released. It
should be noted that no compressors, pumps and other
mechanical support equipment are required. Sketches of
the barrier are shown in Figure 1.
The barrier system, as developed, consists of four
sub-systems:
1. Barrier Subsystem
2. Mooring Subsystem
3. Package Subsystem
4. Deployment/Retrieval Subsystem
A brief discussion of each of these subsystems follows.
*Since completion of this work in June 1970 the U.S. Coast Guard
has lowered its containment objectives to approximately a 1 knot
current. This has resulted in some barrier design changes which have
not been included in this paper.
369
-------
370 PHYSICAL REMOVAL ..
URETHANE ELASTOMER COATING
POLYETHEH FOAM - -
ELASTOMER LAYER
END FITTING
1 CONNECTOR
Figure 1: Barrier Schematic
Barrier Subsystem
The unique feature of the barrier subsystem is the
achievement of stability and buoyancy by utilizing readily
available seawater and air, combined with the use of stored
potential energy (plastic "memory") in the compressed
foam. Although the "dynamic keel" is essentially weightless
in water, the large displaced volume of the trapped water
and the large waterplane area provide excellent sea con-
formance characteristics. The stored energy in the com-
pressed foam is similar to spring compression, and has a
long shelf life which requires little or no maintenance.
These features eliminate the need for ballast weights and
power sources, and simplify the logistics of air transporta-
tion and delivery, and on-site operations. The barrier is
modular, each module being 17 feet in length, and can be
assembled to contain oil slicks of a wide range of sizes. The
above-water portion extends 2 feet above the water level,
and the below-water section extends 4 feet below water.
Seals prevent seepage between modules, and connectors
provide the structural requirements to keep the barriers to-
gether. A Dacron strength belt is located in the center of
pressure of the bottom section of the barrier and provides
the strength required to maintain the barrier's structural
integrity under high sea state conditions. The strength belt
of the barrier is designed with an ultimate strength in excess
of 200,000 Ibs.
The upper section is sealed for buoyancy and acts as a
surface barrier. The foam for the upper section is covered
with a urethane elastomer skin which has been especially
chosen for its resistance to oil, and for its excellent strength
and abrasion resistant properties.
The sealed upper section has a specially designed air
valve which allows air to enter while preventing the entry of
water. This allows the upper and lower sections to both be
compressed for transportation.
Figure
Lt Weight Barrier Under Tow
Mooring Subsystem
The primary mooring subsystem in the early phases of
deployment of the barrier consists of two ships attached
to the ends of the barrier, which maintain the barrier
in a parabolic configuration with respect to the slick.
(See Figure 2). If current speeds are excessive, the
barrier may be allowed to drift to some extent with the
current, i.e., the barrier moves with a velocity relative to
the oil slick that is smaller than the current velocity. Use of
this "active" mooring system permits rapid deployment of
the barrier in such a way that it will be effective and can
still be deployed in four hours. In later phases of deploy-
ment, a specially designed passive mooring system can be
used. This system consists of a polyethylene foam cylinder
upon which is wound an appropriate length of mooring line
together with an anchor. This system is modular and can 'oe
attached at any of the convenient barrier mooring loca-
tions. The spring constant of the mooring lines has been
specifically designed to minimize dynamic forces on the
barrier and enhance the barrier's oil containment capabil-
ity.
Package Subsystem
The package subsystem consists of a lightweight struc-
tural box which is capable of containing approximately 500
feet of oil containment barrier. The box is !6 feet
long, 8 feet wide, and 6 feet high. These dimensions have
been chosen so that two boxes can fit within the cargo
compartment ofanHC-130B aircraft. The containers have a
special aluminum skid which is compatible with a rail-type
aerial delivery system. The container package itself provides
-------
"DYNAMIC KEEL" SYSTEM 371
the constraints for the barrier so that when these con-
straints are released, the barrier unfolds and automatically
self-deploys. The aluminum skid acts as anchor for the bar-
rier string upon initial deployment. Figure 3 shows an art-
ist's concept of aerial delivery and automatic deployment
of the barrier package.
Deployment/Retrieval Subsystem
The deployment/retrieval subsystem consists of the
parachutes, rigging and release mechanisms required to air
deploy the oil containment barrier. The parachutes used are
a small extraction chute and four large G-ll. 100 ft. di-
ameter main parachutes. The rail-package interfaces within
the plane are an additional portion of the deploy-
ment/retrieval subsystem.
Description of Research Undertaken
Introduction
A comprehensive series of studies, tests and designs
were completed during this program. Work included studies
and tests to assess the hydrodynamic response of the barrier
in waves and currents; to determine the environmental
properties of previously selected materials; to assess the
strength capabilities of the barrier; to test the structural and
operational properties of the mooring sub-system; to test
the package sub-system; ami further operational tests (in-
cluding an air drop test) to assess the deployment capability
of the barrier. A detailed description of the test program
follows.
Current Tests wjth Oil
Introduction
When water flows past a boom-type barrier a low pres-
sure region is formed about the bottom edge of the boom.
This low pressure region is caused by the difference be-
tween the relatively high velocity of the water as it flows
under the barrier, and the relatively low velocity of the
water near the surface. Under certain conditions oil from an
oil film or slick located above this low pressure region will
drain into the low pressure region and will be swept under
the barrier. The conditions that must be met for drainage to
occur are certain combinations of water velocity, oil den-
sity, and depth of barrier below the oil/water interface.
Previous work shows that near-boom drainage or
run-under is a gravity phenomenon and the point where
drainage will occur can be approximately represented by a
dimensionless number. The dimensionless number that is
used in connection with the drainage phenomenon is called
the densimetric Froude number (NpRjj*) and includes the
combinations of parameters mentioned above.
The objective of these tests was to investigate the
phenomenon of run-under or drainage, and to determine if
there was any relationship between the cross-sectional
shape of a barrier and run-under.
Models of five cross-sectional shapes (See Figure 4)
were tested and their performance compared on the basis of
densimetric Froude numbers.
far
Figure 3: Aerial Delivery of Lt Weight System
EACH MODEL 2' LONG
TYPE I
. TYPE U
TYPE HE
TYPE
. TYPE 1C
Figure 4:
V
Model X-Sections
TRD
LS Pw - Po
Pw
V = Free stream velocity
L = Depth of barrier below slick
g = Gravity constant
pw = Density of water
po= Density of Oil
Apparatus and Procedure
- The tests were conducted in a 2'x2' closed-circuit cur-
rent channel specifically designed and constructed for these
tests. Currents up to 1.5 ft/sec, were produced by an educ-
tor; water level was controlled, and oil leakage prevented by
a weir located in one corner of the channel. Two adjacent
-------
372 PHYSICAL REMOVAL ...
four foot long acrylic windows were located on one side of
the channel.
Several methods of measuring current velocities were
employed, (including a flow meter that quickly became
fouled with oil) but only one proved satisfactory. This
method consisted of measuring the time required for neu-
trally buoyant particles to travel a measured distance.
The oils used in the test were either No. 5 diesel fuel
(S.G. = .92) or No. 2 Diesel fuel (S.G. = .87).
All tests were performed using the following proce-
dure:
1. Model placed in channel.
2. Tank flooded, water level in channel adjusted and
eductor adjusted to produce weak current.
3. Oil poured on water surface upstream of model,
water temperature, oil type and quantity recorded.
4. Current velocity increased in increments and the
following measurements taken at the center of the
channel with each increase of velocity:
—Current velocity
-Slick length
—Slick thickness at model
—Depth of model below slick
5. Current velocity further increased until run-under
occurred and above measurements repeated.
6. Current velocity decreased and Steps 4 and 5 re-
peated until sufficient amount of data was recorded.
1.5-
6 1.0-
.50
V
LgP.-Po
1.00
1.50
Figure 5:
D S.G. > .92 (NO. 5 FUEL OIL)
V S.G. • .87 (NO. Z FUEL OIL)
© OIL/WATER BUBBLE
Run-Under Points for Five Bairjpr Cross
Sections Tested
Results
The results of these tests are illustrated by Figures 5
and 6. Figure 5 includes points for all five cross sectional
shapes tested. The points without circles represent points
where there was clearly visible run-under consisting of bub-
bles and/or thin streams of ofl. The points with circles re-
present points where the run-under consisted of water-filled
ofl bubbles. The straight line represents the division be-
tween ofl bubble run-under and water-filled ofl bubble
run-under for Shpae No. V. The slope of this line is a densi-
metric Froude number. The range of slopes for equivalent
lines for the other four cross-sectional shapes was small; the
values range from 1.00 to 1.25.
Figure 2.3 is a comparison between experimentally
measured volumes and theoretically predicted volumes for
measured lengths of oil slicks. All of the measured volumes
were obtained from test data for two tests randomly
selected.
.6-
J -4
O
MEASURED VOL.
— j
7
L
THEORE«ALVOL.»BESTF,T-
LINEAR REGRESSION
TESTN
-------
"DYNAMIC KEEL" SYSTEM 373
Discussion of Results
It can be seen from Figure 5 that although the Froude
number at run-under varies with density/viscosity, it is
above 1.0 for all cases where the run-under consisted of oil
bubbles. Although it is not certain, it appeared that the
water-filled oil bubbles had a very thin skin of oil. If this is
true then the positions of the water-filled oil bubbles as
plotted on Figure 5 would be misleading since the
value assumes that the bubbles are solid oil.
Lg Pw - Po
Pw
The water-filled oil bubbles cannot be considered reliable
evidence; also, the oil contained in these bubbles is minimal
and contributes little to total oil leakage.
The experimental results were compared to theoretical
predictions, and in general the values of NpRD at
run-under, in regions tested, agree quite favorably with
those predicted in the analysis.
There did not appear to be any significant differences
in performance among the five cross sections tested. If
there is any difference in performance that is shape de-
pendent, it was not determinable within the accuracy and
scope of the tests performed. The cross-sectional shape
selected (Shape V) was based on factors other than its abil-
ity to prevent oil run-under in currents. The depth of the
selected barrier shape was, of course, based on performance
requirements in currents.
The experimental values in Figure 6 agree quite well
with theoretical predictions. This indicates that the ana-
lytical solution is valid and can be used for projecting oil
pile-up for prototype barriers.
Conclusions
1. Run-under or drainage appears to be independent
of the cross-sectional shape of a barrier.
and damping coefficients; model testing in waves including
regular and irregular waves, shallow water waves and various
model configurations. All of these tests were performed at
Ocean Systems, Inc. Reston facility using a specially de-
signed wave tank.
Static Stability Tests
Static stability tests were conducted with models of
two different cross-sectional shapes. Because these tests
were conducted prior to the selection of the final cross-sec-
tional shape, the final shape was not tested; however, the
experimental data from the shapes tested supported the
analytical approach employed for determining static sta-
bility. The results of these tests indicated that the barrier
had a large positive stability throughout its whole roll range
due to the mass of the entrapped water.
Determination of Added Mass and Damping
Coefficients
Values for the added mass and damping coefficients
were needed in order to determine the theoretical response
of the barrier in waves and to scale model results up to full
scale conditions.
These coefficients were determined by recording the
free oscillation of a barrier model when deflected and re-
leased. A 1/4 scale model of the barrier was placed laterally
in the wave tank in front of the acrylic window, displaced
downward, and then released. The resulting oscillations
were photographically recorded and the results analyzed.
The heave natural period of the 1/4 scale model was
scaled up to give a heave period for the full scale prototype
barrier of 1.8 sec., which is well below the significant
period of exciting ocean waves.
For a wave period of 5.5 sec., which corresponds to the
significant period of waves under maximum effectiveness
conditions, the value for added mass was found to be .37.
This value agrees quite well with analytically determined
values for the added mass.
The experimentally determined damping coefficient
was determined to be approximately 0.21, again-in good
agreement with theoretical values.
2. The point (current velocity) where run-under will
occur, for a specified barrier depth, oil slick depth,
and oil density, is predictable using the analytical ex-
pressions developed in the course of the program.
Determination of Barrier Sea Response
Introduction
Barrier sea response was determined in three basic test
phases: static stability tests; determination of added mass
Wave Testing-General
The objective of the wave tests was to determine the
dynamic response for scale models of the contianment
barrier. The tests were conducted in a wave tank located in
the Ocean Systems, Inc. Reston, Va. facility. A total of 160
individual wave tests were performed, including models of
two different scales, and a variety of wave conditions.
Wave Tank
Because many of the tests required the use of various
types of contaminating oil and Ocean Systems wanted easy
access to the tank for performance of a large number of
-------
374 PHYSICAL REMOVAL ...
MOMTIW MOOUCTS
MDOCU (O
StUDDRWl.
MAKINC PLTWOOO
o
z
o'-
Figure 7: Wave Tank
tests, a tank was designed and constructed at the Ocean
Systems, Inc.'s Reston facility.
The tank as constructed is shown in Figure 7. The
wavemaker is capable of producing regular waves with
heights in excess of one foot with periods ranging from 0.5
to 3.5 sec.
Three wave absorbers are installed in the end of the
tank; they dampen out about 95% of the wave energy for
waves with periods less than 2 seconds.
Scale Models
The dimensions of models used in the wave tests were
geometrically scaled from the prototype. Models of two
different scales, 1/8 and 1/4, were used in the tests. The
upper section of the 1/4 scale model consisted of poly ether
foam coated with urethane elastomer; its lower section of
reticulated polyester foam 100 cells/inch. The bending stiff-
ness of .the 1/4 scale model was not scaled from the proto-
type; since this model was only tested with the longitudinal
axis parallel to the wave fronts this parameter was not im-
portant.
Two types of 1/8 scale models were constructed: one
had a silicone (RTV-116) coated top section, the other a
polyethylene film covered top section; both had reticulated
polyester foam bottoms.
The bending stiffness of the models was slightly (al- '
though not significantly) higher than that desired as de-
termined by scaling laws; however, the difference was ac-
counted for in the computer program used to make theo-
retical predictions for model motion. It was not necessary Figure 8:
to scale the drainage rate for the keel since drainage rate
-100*
THEORETICAL
2 3
CO (RAO/SEC)
O g SCALE MODEL TEST
V$ SCALE MODEL TEST
Heave Response Operator & Heave Phase Angle
Vs Wave Frequency1 for Prototype
-------
"DYNAMIC KEEL" SYSTEM 375
-50*
< -IOO--
<
I
-150*
1-50
UJ
0.
o
ui 1.00
V)
z
o
a.
10
u
°= .50
O
THEORETICAL
O
o
o
CO (RAD/SEC)
O Q SCALE MODEL TEST
V 5 SCALE MODEL TFST
Figure 9:
Sway Response Operator & Sway Phase Angle
Vs Wave Frequency for Prototype
was slow compared to wave frequencies for both models
and prototype.
Testing Procedures
The model to be tested was placed in the wave tank in
front of the acrylic window and moored with elastic bands
having a calibrated spring constant. The spring constant of
the elastic bands was scaled down from prototype mooring
lines.
The wave maker was turned on, a wave of constant
period and height produced, and motions of the barrier, and
wave profile were photographically recorded with a movie
camera.
Data Reduction
The films of barrier motion were projected onto a
screen with a grid using a Photo-Optical Data Analyzer to
analyze the motions.
The heave and sway motions for each wave were divi-
ded by the wave height to determine the response operator.
Trie phase angle between trough or crest of the wave and
minimum or maximum heave and sway records was also
determined. It should be noted that when the peak of the
motion occurs before the crest of the wave the phase angle
is negative, and when it occurs after, the phase angle is
positive. This notation is consistent with the output of the
theoretical computer programs.
i.oo
HEAVE
a
PITCH
RESPONSE
OPERATORS .50
.25
4 6
UKRAD/SEC)
O HEAVE
A PITCH
±SCALE
TENSION = 20 LBS
Figure 10: Heave and Pitch Response Under 20 Lb Tension
The mean values and standard deviations were cal-
culated for the response operators and phase angles. These
values were then plotted versus wave frequency and com-
pared to the output of the theoretical computer programs
for the models.
Regular Wave Testing—Models Parallel to Wavefront
These tests were conducted with both 1/8 and 1/4
scale models in waves corresponding to full scale periods of
1.86 or 5.88 sec. and full scale heights up to 6 ft. The heave
and sway results for these tests, scaled up to prototype, are
shown on Figures 8 & 9. Also shown are the theoretical
response operators and phase angles as computed by linear
theory. (See Task 3.1.3 in the Appendix).
It can be seen that the heave phase angle is in good
agreement with theory while the heave response operator is
not. The disagreement in heave response is thought to be
primarily due to the assumption of linearity in the theory.
The model tests results indicate that the heave response-of
the barrier is much better (with respect to surface conform-
ance) than predicted by theory.
The sway phase angle is in good agreement with theory
as are the sway response results for the 1/8 scale tests. The
disagreement between the 1/4 scale siway response and
theory is thought to be caused by transport velocities as-
sociated with the wave maker when producing low fre-
quency waves. It can be seen that the agreement with
-------
376 PHYSICAL REMOVAL...
theory for sway response becomes better for the higher
frequency waves.
Models in Tension Test- Regular Waves
These tests were conducted with a string of 1/8 scale
models moored perpendicular to the wave fronts. The
models were tested in waves with full scale periods from 3.1
to 8.4 seconds and with full scale tensions of 0-15,000 Ib.
The barrier models were maintained under constant
tension by mooring one end of the model string, and on the
other end attaching a line that ran over a sheave and had a
free-hanging weight attached.
Tests were conducted with tensions of 0,10,20 and 30
Ibs. in the model string. The heave and pitch response op-
erators for model motion were calculated for all tests and
were compared to output from a theoretical computer pro-
gram. The agreement was fairly good and any discrepancies
are thought to be associated with modeling problems. Fig-
ure 10 shows the results of one test series.
Other Wave Tests
Other tests were also run of the 1/8 scale models
arranged in a ring (in both regular and irregular waves) and
of the 1/4 scale barrier models in shallow water waves.
Space does not permit a discussion of these results.
Conclusions
1. With due allowances for the problems in model
testing, experimental results show that linear theory
predicts phase angles reliably but fails to predict re-
sponse operators (particularly heave) at high fre-
quencies and large wave amplitudes.
2. In the frequency range where the maximum energy
of the sea spectrum is concentrated, linear theory pre-
dicts barrier motions with fair accuracy.
3. In general, the barrier conforms more closely to
the sea surface over a wider range of frequencies than
predicted by linear theory.
Wave Tests with Oil
Regular wave tests were conducted on 1/8 and 1/4
scale models of the prototpye barrier to determine the per-
formance of the barrier in containing oil slicks. The models
were tested in regular waves with full scale periods ranging
from 1.9 to 8.9 sec. and full scale heights up to 4.8 ft. The
oil slicks in the tests had full scale thicknesses up to 3.5 ft.
The 1/8 scale model used in these tests was the same
model used in previously mentioned tests. Only a few tests
were conducted with this model because of testing pro-
blems.
After the 1/8 scale tests had been completed a
single 1/4 scale model was used. A polyethylene curtain
(See Figure 11) suspended by elastic bands was hung in
front of the model with its ends attached to the ends of the
model. Thus, a closed fence that was transparent to waves
was formed in front of the model. The polyethylene curtain
permitted a slick of significant depth in front of the model '
4- SCALE BARRIER
ELASTIC BANDS
WAVES
-POLYETHYLENE SHEET
:LASTIC MOORING
LINES
Figure 11: 1/4 Scale Oil Containment Test.
and did not noticeably affect the motion of the barrier
model. Calibrated elastic bands were used to moor the
model.
Eleven tests were conducted using the 1/8 scale model
ring and No. 2 fuel' oil; forty-three were conducted using
the 1/4 scale model and No. 5 fuel oil. Mean values for
wave heights and periods were measured for each test along
with measurements of slick depth. The results of the tests
were tabulated and the datum points plotted on graphs in
various forms in an effort to obtain conclusive and quanti-
tative data concerning oil leakage.
It was suspected that a primary cause of oil leakage
would be differential velocities between the barrier and
water particles. The results of the tests did indicate that oil
leakage rates were higher at higher predicted differential
velocities although there was much scatter in the data. It is
believed that the actual differential velocities in the wave
tank were larger than those calculated for the barrier mo-
tions. These larger velocities were probably caused by
seiches and transport velocities in the tank. (These same
problems caused irregularities in the sway data.) Possibly, if
the differential particle velocities in the tank had been
measured with a flow meter, the results would have been
more indicative of what was occurring.
The results of the tests did indicate that for full scale
waves with periods greater than about 3 sec. very little
leakage would occur for slick depths less than one-half the
barrier depth. For full scale waves with periods less than
about 3 sec. the wave height had to be large (> 2 ft.) for
leakage to occur, and then the leakage was mostly in the
form of splash over the top of the barrier.;
Towing Tests
Two separate series of towing tests were conducted
on models of the barrier: the first were to determine
longitudinal towing forces required for long strings of
barrier modules in calm water and in waves; the second, to
determine dynamic forces induced in the barrier when
towed or moored in the deployed (parabolic) configuration.
All testing was performed at Hydronautics Ship Model
Basin, Laurel, Maryland. The main towing tank is 310 feet
long, 25 feet wide and 11 feet 8 inches deep. The wave
-------
'DYNAMIC KEEL" SYSTEM 377
Figure 12: 1 /12 Scale Model Te st
making apparatus is capable of producing regular waves of
20 inch height and irregular (sea spectrum) waves of 14
inch significant height. Both digital and analog records were
obtained for the tests.
Model String Tests
A 16 ft. long 1/8 scale cross-section model was towed
longitudinally at three velocities in calm water and at one
velocity in irregular waves. Tests in irregular waves were run
for two nominal values of significant wave height.
Drag forces were measured with a force gauge mounted
on the towing carriage, electronically integrated over time,
and recorded in digital form along with the carriage velo-
city. Sea spectrum waves with the correct significant height
were produced automatically by the wave maker.
Typical scaled forces required for towing 100 ft. of
prototype barrier at 4 knots are: 400 Ibs. in calm water;
600 Ibs. in 3.8 ft. waves; and 700 Ibs. for 7.7 ft. waves.
Deployed Barrier Model Tests
These tests were conducted on a 1/12 scale model of
1,000 ft. of prototype barrier. The intent of the test was to
find dynamic forces induced in the barrier by waves when
the barrier is being towed or moored parabolically in a
current.
- Hydronautics, Inc. Ship Model Basin
These forces were simulated by towing the model in
the test channel at prototype velocities up to 3 knots and in
irregular waves up to 14 in. (14 ft. full scale) significant
height. The ends of the barrier model were attached at
points on opposite sides of the towing carriage so that the
model assumed a parabolic shape when towed. Forces and
wave parameters were measured and recorded using the
same methods as in the previously described test. A photog-
raph of the test apparatus is shown in Figure 12.
Digital records with integrated force values were ob-
tained for 2 and 3 knot prototype tow velocities in calm
water. Analog records for each test were reduced to obtain
significant wave heights and forces for tows in irregular
waves. The significant forces determined for the wave tests
were compared to the forces recorded for static (i.e., calm
water) conditions to obtain a "dynamic factor." The signi-
ficant "dynamic factor" was determined to be approxi-
mately 1.5-1.6 for 20 ft. significant waves in velocities up
to 3 knots. The maximum possible "dynamic factor" will
be 3.1-3.3 times the static value.
It is recommended from the results of the test that the
prototype barrier be capable of sustaining approximately
3.5 times the steady state value of tension caused by cur-
rents or towing speeds.
-------
378 PHYSICAL REMOVAL
Other Tests
A number of other tests were conducted in the course
of the program which cannot be described in detail because
of space limitations. A listing and brief summary of these
tests is given below however:
1. Material Tests - The following parameters were
tested: tensile strength, tear strength, delamination
resistance, oil degradation, recovery from com-
pression, and abrasion resistance. All chosen materials
were determined to be suitable for the application.
2. Seal Between Modules Test - The oil holding capa-
bility and flexibility of the seal were determined to
be satisfactory.
3. Absorption Rate Tests - It was determined that the
dynamic keel of a full scale model would become
completely saturated with water in 4 minutes.
4. Drainage Rate Tests - It was determined that 75% of
the water in the keel would drain out in 8 minutes if
the keel were completely removed from the water, as
in recovery operations.
5. Air Valve Tests - The selected air valve design was
determined to be capable of inflating the barrier with
air only, even if the barrier were temporarily sub-
merged in waves.
6. Packaging Tests - It was determined that the barrier
could be compressed to less than 20% of its original
volume without damage and then returned to its ini-
tial configuration. See Figure 13.
7. Air Drop Test - The drop and deployment sequence
of the barrier was verified to be acceptable. See Fig-
ure 14.
8. Mooring Buoy Test - These tests determined that a
mooring unit with 1000 ft. of line can be laid in 5
minutes. See Figure 15.
°. Structural Tests - Structural Tests of the barrier units,
barrier connector, and mooring buoy units verified
the structural integrity of the system.
10. Oil Removal Tests - Tests indicated that oil can be
removed from the foam keel without adversely affect-
ing barrier characteristics.
Figure 13: Packaging Operation - 1/2 Scale Mode!
-------
"DYNAMIC KEEL" SYSTEM 379
I
Figure 14: Air Drop Test - 1/2 Scale Model
„ ...
F
» r*v^
Figure 15: Mooring Line Being Unspooled from Buoy
-------
380 PHYSICAL REMOVAI
CONCLUSION beginning of this paper. This conclusion assumes, of
It was determined after substantial studies and course, that the system is deployed in the optimum
testing that, within its working range, the described mode, such as "drifting" under high current
oil containment system is* fully capable of meeting or conditions. In summary a unique and effective high
surpassing all its design objectives discussed in the seas oil containment system has been demonstrated..
-------
PNEUMATIC BARRIERS FOR OIL
CONTAINMENT UNDER WIND, WAVE,
AND CURRENT CONDITIONS
David R. Basco
Department of Civil Engineering
Texas A &M University
ABSTRACT
An experimental laboratory study of the pneumatic
barrier has recently been completed at Texas A&M
University (sponsored by the U. S. Coast Guard). Both the
fluid mechanics of air-bubble generated currents and their
effectiveness for containing oil under wind, wave, and
current loadings were investigated.
The bubble-generated current has been found to
provide an effective means of containing oil on water.
However, under strong currents (2 knots) or breaking wave
conditions, large quantities of air are required and the
substantial increase in power requirements which results
may prove the system uneconomical for some applications.
Consequently, use of the pneumatic barrier to prevent
oil spreading on water is recommended for protected areas
with low (below 1.0 knot) currents.
INTRODUCTION
For Phase I of the U.S. Coast Guard's Oil Spill
Containment Program, Wilson Industries, Inc. of Houston,
Texas was awarded one of three "Concept Development"
contracts for a heavy duty containment system. The
research effort was subsequently subcontracted to Texas
A&M University, College Station. This paper presents the
essential laboratory results of that study for the unique
application of a pneumatic system to contain oil.
Mechanism for Containment
An air bubble released below the surface of a liquid
such as water will rise to the surface because its buoyant
force is greater than the combination of fluid drag on the
bubble and its weight. As the bubble rises it drags water
along with it creating an upward flow. At the free surface
the air bubble is dissipated. However, the upward liquid
momentum is deflected and causes a surface current. If a
number of small bubbles continuously flow from a
submerged duct, a steady surface current can be used to
oppose the potential spreading energy of oil of a given
depth. When equilibrium is established the oil is essentially
contained by the bubble generated current. This forms the
basis of the air or pneumatic barrier for oil containment.
One objective of the research was to determine the
relationship between the quantity and manner of air
bubbles released and the kinematics of the generated
surface flows.
Oil flowing over water is a complex phenomena. Being
lighter than water, gravity forces "drive" the oil to "seek"
its own uniform level above the water surface. In a system
open to the atmosphere, the driving force is solely the
hydrostatic pressure head of the oil. Thus, a thick layer of
oil will have a greater tendency to spread than the same oil
of smaller depth.
Once the flow commences the gravity forces which
originated the motion soon give way and are dominated by
viscous shear at the interface so that the viscous forces
govern the dynamics of the motion. Spreading decreases the
oil thickness.
At some further point when the oil becomes of "film"
thickness, surface tension forces become dominant and this
phenomena determines the manner in which further
spreading take place. Superimposed wind and wave forces
add considerable complexity to the situation.
Fortunately, under equilibrium conditions that must
prevail during oil containment the oil behind the barrier is
essentially stationary so that the retarding viscous forces
and surface tension forces are not present or very weak.
Hence, analysis of the problem reduces to the case where
the ratio of gravity forces to inertia forces describe the
381
-------
382 PHYSICAL REMOVAI
behavior. And, since two liquids of differing densities are
involved, the ratio of the two forces is characteristically
described by the densimetric Froude number, FD, i.e.,
P _ gravity forces
inertia forces
_ V
gLApA
0)
pw
where:
FD = densimetric Froude number, dimensionless
V = = characteristic reference velocity
g = gravity constant
L = characteristic reference length
Ap = pw . PO = mass density difference
Po = mass density of oil
pw = mass density of water
Eqn. (1) becomes, if SG0 is the oil specific gravity,
(2)
For oil spill containment by pneumatic barrier, the
maximum surface velocity generated by the bubbles, Umax
can be used as reference. The characteristic reference length
is naturally the mean oil depth contained, h. Consequently,
u
max
gh(l-SG0)
(3)
It is apparent that for a given oil, as the driving force, h
increases, the spreading tendency (velocity) increases and
for equilibrium to be maintained a "retarding" force
primarily composed of the kinetic energy in the bubble
generated current must also be increased. To be determined
therefore, is the critical ratio of Umax/'l| gh (1 - SGO)
the crucial point when failure occurs or begins to occur.
Letting « be a coefficient equal to (Fjj) critical at failure,
Equation (3) can be written
U,
max
gh(l-SG0)
(4)
The second purpose of this research was to determine
the critical failure value of « under stagnant water, wave
and current conditions. The method of solution was
essentially experimental since the bubble generated
velocities retarding the oil are not completely understood,
particularly when oil is present in significant depths near
the barrier. It was anticipated that a. would be a true
constant independent of the scale of the laboratory tests.
Kinematics of Pneumatic System
The use of a bubble induced surface current for wave
attenuation has been proposed for many years. Fortunately
therefore, a number of laboratory scale and prototype
studies are available in the literature regarding the
kinematics of the pneumatic system. A list of the more
important publications appears as Table 1. The geometrical
variables of interest are also shown in Table 1 and defined
in Fig. 1 and where they first appear in this paper.
Surface Currents
Taylor1 used an analogy between the hot air flow from
a heat source and the vertical current induced by the air
bubbles. He found theoretically that the vertical current,
Vjnax (Fig. 1) is related to the unit discharge rate of air, q
by the following relationship
where:
j i «., SPACES
IT5 PER FOOT
n
Q. m j _ AIR FLOW/RATE"
W I q " PER UNIT WIDTH
ORIRCE
• DIAMETER
, MANIFOLD
DIAMETER
MANIFOLD
PRESSURE
SECTION A-A
Figure 1: Definitions of Geometric, Fluid and Flow Variables
g = the gravity constant
K = an experimentally determined constant
The constant K was found to be about 1.9 from the hot air
analogy tests. If no energy loss occurs when the flow
momentum changes to the horizontal direction at the
surface then the theoretical surface velocity as determined
by Taylor becomes
Umax = l-9(gq)l/3 (Theoretical) (6)
Since 1955, many experiments have been performed in
the laboratory and at prototype scale to determine the
constant in Eqn. (5). Those felt to be most significant have
been plotted as Fig. 2 which also includes Taylor's
theoretical result. Although the general trend of all
experiments was similar, a wide variation in K values were
obtained. Possible reasons for these variations are:
1. Inconsistent location where Umax is experimentally
determined.
2. Failure of all investigators to correct test air
flowrates to standard temperatures and pressures.
-------
PHYSICAL REMOVAL
383
GRAPH OF AIR DISCHARGE VERSUS
MAXIMUM SURFACE VELOCITY
0002 —
0.001
01
40 5O 6O 70 8O9OK)
. MAXIMUM SURFACE VELOCITY. FT/SEC
Figure 2: Air Discharge Versus Maximum Surface Velocity Previous Research
-------
384 PHYSICAL REMOVAI
3. Differences in orifice size and number, i.e.,
variations in bubble size produced.
4. Scale effects possibly due to the depth of manifold
pipe submergence.
5. Boundary effects of bottom and sides.
6. Experimental error.
Fig. 3 illustrates the experimental results of Umax
plotted against q for four differnt water depths tested in
four different flumes in this study. In all tests Umax was
measured at x/H about 0.5 with 1/16-in. diameter holes
spaced 24 per foot. The trends in all cases followed the
theoretical slope and the constant K appeared to increase
slightly with water depth. The one exception was in the
wide (5 foot) flume when there appeared to be very little
change of Umax with increased manifold depth, H. Further
tests at depths of 25 to 30 ft and in wide flumes are needed
to clarify this result.
Under identical test conditions the size of the orifice
nozzles in the manifold pipe were varied. A slight increase
in the constant K with a smaller orifice resulted. In many
cases, however, experimental error was larger than the
apparent differences noted.
In stagnant water the results plotted in Fig. 3 for Umax
versus q indicate a constant, K of about 1.5 which is close
to that reported by Bulson (1)* (10). Little change in
performance was noted with variation in orifice size which
is also reported by Bulson (1). The flow boundary
exhibited no effects for the limited range of tests
performed. The manifold pressures were found to increase
as hole size diminished.
I.O
ae
0.6
Q4
02
.«£
' ft
01
a oe
006
FUME COMPARISONS
q - »» - Umo«
V 0.5
*' fc
06 OB 1.0
4O GO BO K>O
Umax (ft/sec.)
Figure 3: Effect of Water Depth on Maximum Surface Velocity
Velocity Profile Generated
All previous research efforts essentially found that the
generated current developed a linear profile with depth.
'Numbers in parenthesis refer to those authors listed jn Table 1.
i.OO
0.90
TWO FEET WIDE
WAVE CHANNEL
• RUN NO.
O RUN NO.
• RUN NO.
O RUN NO.
Q RUN NO.
ARUM NO.
A RUN NO.
VRUN NO.
U
TJmox
I (TEST NO. I)
2 (TEST NO. Z)
3 (TEST NO. 2)
4 (TEST NO. 3)
5 (TEST NO. 3)
6 (TEST NO. 3)
2 (TEST NO. 4)
3 (TEST NO. 4)
T « 2.0 feet
STAGNANT CONDITIONS
01
Umox
Figure 4: Dimensionless Velocity Profile with Depth
Taylor suggested that the distance, b from the surface to
the point where the generated current was zero would be
approximately 0.28H. Sjoberg and Verner (9) and others
(5) (14) (4) suggested 0.25H.
Besides the measurement of Umax at x/H equal to 0.5,
for many tests a depth velocity profile was also established
for this study. The measured profile was approximately
linear and the depth of velocity reversal, b was
approximately equal to one-quarter of the manifold depth,
H. Fig. 4 summarizes the results of many tests at different
air flowrates, water depths and manifold depths on a
dimensionless basis. These results were consistent with
those previously report (5) (4) (14) for profiles measured at
x/H about 0.5
Decay of Surface Currents Under
Stagnant Conditions
Many measurements were also taken to determine the
reduction of Umax as the distance from the bubble
eruption increased. The decay was essentially linear with
maximum surface currents found near x/H about 0.5. To
facilitate a dimensionless plot, Umax at x equal to zero was
established by extrapolation of each graphical plot of the
results. The ratio of the surface velocity Umax to that
-------
PNEUMATIC BARRIERS... 385
TWO FOOT WIDE CHANNEL
O TEST NO. I RUN NO. 2 H/T = 10
A
D
V
O
X
TEST NO. I
TEST NO. I
TEST NO. I
TEST NO. 7
TEST NO. 7
RUN
RUN
RUN
RUN
RUN
NQ
NO.
NO.
NO.
NO.
3
4
5
I
2
1.0
10
1.0
0.5
0.5
Umax
(Umax)Xs0o.6
STAGNANT
Umax
(Umax)x=0
- vs - —
Figure 5: Dimensionless Surface Velocity Profile
extrapolated value at x equal to zero plotted against x/H
for a number of tests is presented as Fig. 5. Although some
scatter existed, the solid line roughly indicates the trend of
the results. If Umax at x/H equal to 0.5 is sued as reference
the trend is indicated by the dashed line of Fig. 5. The
manifold location with respect to the floor boundary did
not appear to be of importance.
Previous investigations also established that the
horizontal surface velocity decreased with increased
distance from the manifold certainline. Due to the eruption
of air bubbles the maximum Umax usually occurred
between 0.3H and 0.6H (1) (5) (15).
Effect of Steady Channel Flow
on Bubble Current
A steady, uniform, open, channel flow added to the
bubble current has been found to shift the bubble pattern.
Consequently, instead of the center of bubble eruption
occurring directly above the submerged pipe, it occurs some
distance downstream.
It was postulated that the individual velocity profiles
of open channel flow and bubble-generated current could
be linearly superimposed together. If this theoretical
supposition could be experimentally proven, then the
resulting combined velocity profile could be theoretically
estimated for any combination of channel flow and bubble
current.
Since the stagnant bubble current was symmetrical
about the centerline of bubble eruption, it was
hypothesized that the channel flow would decrease the
upstream bubble generated current and increase the
downstream current by similar amounts. Thus the upstream
decrease would be the critical case for oil containment and
of most interest for this application.
Experimental tests were performed in an 18-in wide
flume with water depths of around 7.5 feet. In one
representative case an air flowrate of 0.436 cofs/ft was
added in the flume which would normally create a Umax of
4.1 ft/sec under stagnant conditions. Velocity profile
measurements were then taken at five locations upstream of
the shifted bubble eruption. The characteristic linear depth
profile was still present and the resulting surface current
generated, U'max still decayed with distance from the
centerline of eruption. This test was carried out with a
mean velocity of 1,78 ft/sec present in the open channel.
With the aid of Figs. 3 and 5 the theoretical stagnant
bubble generated profiles were estimated at each location
of interest and plotted as the triangular profiles in Fig. 6.
-------
386 PHYSICAL REMOVAL...
THEORY -VS- EXPERIMENT
BUBBLES
T7
x.-? o fMt ^t—
Theory—" .T'Vi .
tMpflnniQni '
|— umox-aes 1
b'«l07fl
^
b.H/4-IBfl'
Figure 6: Current Plus Bubble-Generated Velocity Profiles
For this theoretical study b was estimated as 0.2SH or
about 1.88 ft for all cases, Next, the opposing mean flow,
Vm of about 1.78 ft/sec was superimposed at all locations.
The resulting theoretical, surface current, U'max and depth
to zero velocity, b' are indicated as the solid line with
direction arrows in Fig. 6.
The experimentally measured velocities have been
added to Fig. 6 for comparison. There appeared to be
excellent agreement between theory and experiment for all
surface velocities of interest. Even the difficult estimation
of b' showed fair correlation with the experimentally
determined values being consistently greater than b'
theoretical. Similar results were experienced for other air
flowrates in the 18-in flume and for shallower water tests in
a 2-ft wide channel. It was tentatively concluded that the
principle of linear superposition could be applied to
combine stagnant Umax and a uniform channel velocity.
Consequently, the initial objective of the research was
felt to be completed in that the kinematics of the
air-generated currents had been reasonably well established
from the laboratory scale experiments.
Oil Containment
Stagnant Water Conditions
Use of pneumatically developed currents to contain oil
is a relatively new idea and consequently no published
research work is available. However, an unpublished report
by Sjoberg and Verner2 was obtained from Chalmers
University in Sweden which cited references indicating that
the critical constant, a at failure (Eqn. 4) was between 1.0
and 1.4. Their own tests gave an a equal to 1.2,
"... which is required to stop leakage of oil through the
barrier."
Initial laboratory tests were conducted in a two-foot
wide channel with 2 ft of water depth, T and the manifold
located near the bottom, H so that H/T was about 1.0. With
a constant surface current Umax, being generated, the oil
depth contained, was gradually increased until failure
occurred. The ^fgh (1) — SGO) value at failure was then
computed and plotted against Umax- Fig- 7 presents the
results.
4.0 r
3.5
3.0 -
25
Umax
ZO
1.5
1.0
0.5
STAGNANT TESTS
Unai-vs-slghd-SGo)'
h» ofl thickness when failure occurs
determined when barrier fails
either by substantial 08
passing through or over tap
of bubble eruption.
TESTED BY
FLUME H/T SG INVESTIGATOR
TAMU
TAMU
OS 085 TAMU
10 085 TAMU
i- CHALMERS U
10 089
O5 0.89
0.5
0.5
1.0
2.0
Z.5
3.0
Figure 7: Stagnant Water Test Results
Next, the manifold was raised off the floor so that H/T
equalled 0.5. The results are plotted in Fig. 7 for two
different specific gravity oils. In all cases the critical
coefficients were found to lie in the 1.0 to 1.2 range.
Finally, stagnant water tests were performed in an
18-in wide flume with T about 7.7 feet to check failure in
the higher Umax range. These results plotted on Fig. 7
confirm those results previously obtained. In these tests it
was found that as the oil depth h approached the current
-------
PNEUMATIC BARRIERS... 337
depth, b significantly greater surface velocities were
required to prevent failure. Since b depended on the
manifold depth or water depth in the channel this "scale
effect" was greatly influenced by the shallow water in the
laboratory flumes.
Four experimentally determined data points taken
from the Chalmers University tests by Sjoberg and Verner
(9) are also shown in Fig. 7 for comparison. Excellent
agreement was obtained. Consequently a critical oc
coefficient of 1.2 was recommended for preliminary design
under stagnant conditions.
Failure was considered to occur when masses of oil
droplets began to pass through the barrier below the
surfaces or when masses of oil overtopped the barrier.
Channel Current Effects
To test the principle of linear superposition of
velocities previously discussed, the 18-in wide flume was
used with 7.7 ft of water and a mean uniform flow velocity,
Vm of 1.78 ft/sec. A constant bubble generated velocity
was introduced and the effects of the added channel
current tested by adding oil and noting the mean oil
thickness at failure. If the superposition principle should
hold under these conditions then a plot of the effective
surface velocity, U'max(Umax minus V^) versus ^ gh (1-SGO)
should also result in a critical a coefficient of 1.2 near
failure. Fig. 8 presents the results which generally indicate
that this is precisely what happened. Unfortunately, time
was unavailable to completely verify these results
particularly at small values of Umax-
Failure depths were recorded when masses of oil began
to overtop the air bubble eruptions and move downstream.
Significantly, it was also observed that prior to this type of
failure, a number of oil droplets were entrained near the
head region of the contained oil volumes, swept
downstream by the current and passedthrough the deflected
bubble region. This slow rate of oil loss was investigated
independently and entrainment of oil drops found to begin
when the mean current velocity was about 1.6 ft/sec or
greater. Further investigation into the entrainment effect
was not possible due to limited time available for study.
Additional research is recommended to include the effects
of interfacial tension and viscosity on the minimum
entrainment velocity for oil droplet formation at the
headwave.
Wave Effects
With the addition of uniform waves against the air
barrier, two distinct regions of failure were noted by
Sjoberg and Verner (9). In one region the waves were such
that they were practically unaltered by the bubble
generated current against them. These waves were
characteristically long period swells with low values of
steepness and the oil bobbed up and down on the water.
Sjoberg and Verner obtained a values greater than 1.2
with this type of waves present and attributed the slight
increase to "... the pumping effect of the waves, which
press the oil front against the barrier."
2.0 r
1.6 -
1.4
\2
1.0
0.8
0.6
0.4
0.2
18-INCH WIDE FLUME
CURRENT TESTS
Umox-vs-Jgh(l-SGo)'
H=7.6ft
T=7.7ft
d-Vl6in
Vm= 1.78 ft/sec
Umox from Fig. 6
(See Task 080200)
• - h at failure when
masses of oil begin
top overtop barrier
0.4
1.0
1.2
0.6 0.8
Vgh(l-SGo)'
Figure 8: Effect of Channel Current on Containment
The other, more critical case was characterized by
waves of high steepness ratio which broke against the front
of the bubble barrier when moving against an adverse
current created by the bubbles (principle of pneumatic
wave breaker). The potential energy in the wave is
transferred to kinetic energy and a significantly increased
surface velocity, U^x is needed to contain the oil.
Tests by Sjoberg and Verner indicated tha the critical
constant, a increased to about 2.7 when the waves broke
at the barrier. They also indicated that the coefficient
depended on the depth and profile of the generated current
and the steepness of the oncoming wave train.
For the Coast Guard Project, prototype waves had to
be scaled to model sizes for the laboratory tests. A wide
range of wave conditions could be specified and time
limitations prevented testing all combinations. Therefore,
the significant wave characteristics (10 ft height, 6 sec
period, etc.) were chosen as most representative for
laboratory tests in the two-foot wide wave channel available
at a 25:1 scale ratio.
Although some secondary harmonics existed in the
laboratory channel the uniform wave used was essentially
of a scaled size and period very close to that required.
Model surface velocities generated were near 1.0 ft/sec
which scaled-up to about 5.0 ft/sec in the prototype.
As noted above, the required U^x to contain oil was
also considered to depend on the height, H and length, L of
the waves striking the barrier, i.e., on the wave steepness
-------
388 PHYSICAL REMOVAL
H/L. Waves of large steepness ratio approaching breaking
conditions were found to impose additional forces on the
barrier.
In a theoretical analysis of a deep water wave entering
an adverse, uniform current, Unna3 suggested that when
the adverse current, U, was about 25 percent of the wave
celerity, Cj, the deep water wave would be fully attenuated
by the adverse current (hydraulic breakwater). Wave theory
states that waves break when the steepness, H/L exceeds
0.14 in deep water.
Dick and Brebner (14) combined these results and
determined the effects of a uniform, adverse current to aid
in breaking waves. Fig. 9 reproduces the combined effects
and shows at what U/C] ratios breaking occurs for varying
wave steepness.
The significant wave conditions used in this study fell
far from the area where breaking occurs, consequently the
large swells characteristic of the significant design waves
were felt to probably have little or no "pumping" effects
on the pneumatic containment device.
Of primary interest for the laboratory tests was the
case with oil located on the side from which waves were
generated so that the waves possibly moved the oil against
the barrier. Fig. 10 presents the results in the same Umax
versus Vgh 0 - SG
-------
PNEUMATIC BARRIERS... 389
MODEL WAVES
I'25 SCALE RATIO
Umm - vs - /gh (l-SGo
WAVES
Umox
2.0
L8
L6
14
12
Umax 1.0
0.8
0.6
0.4
0.2
0 NO FAILURE
• SMALL OEOPLETS
OF OIL CAUGHT
AND SWEPT THRU
BARRIER
DURING TESTS WAVE GENERATOR
STOPPED AND STAGNANT CONDITIONS
NOTED TO BE CLOSER TO FAILURE
THAN WHEN WAVES PRESENT.
_J I I I
Figure 10: Effect of Model Waves on Containment
If the manifold is assumed to be 25 ft below the water
surface and 1/2 an atmosphere is provided internally to
force the air through the orifices an H of 42 ft of water can
be used for estimation purposes. Also, K equal to 1.5 in
Eqn. (6) will enable the unit volumetric flowrate, q to be
related to the surface current produced. Fig. 11 presents
the resulting horsepowers per foot for Umax from 0 to 10.0
ft/sec. Deeper manifold pipe location, pipe friction losses
and higher manifold pressures would all tend to increase the
hp/ft values shown. Orifice discharge coefficients other
than the 1.0 values assumed would also increase the power
requirements.
As Fig. 11 demonstrates, the horsepower required to
generate surface currents increases approximately at a
three-fold rate. It is therefore apparent that if breaking
waves are present which "pump" the oil past the barrier
(as 3.0) or if strong currents are encountered which
reduce the effective bubble current and cause entrainment,
the excessive power requirements required to generate the
necessarily large surface currents to contain oil make the
pneumatic system uneconomical to operate. The sea state
conditions required by the Coast Guard for their proposed
"heavy-duty" oil containment system were adverse enough
to make the pneumatic system for containment of large,
deep ocean oil spills uneconomical. However, the
pneumatic system is still an effective and economic means
for containing oil in areas where strong currents and
breaking waves are not encountered. Its use is
recommended for protected coastal areas, harbors, docks,
oil unloading facilities, and possibly even to encircle oil
drilling platforms in some instances. Permanently installed
out of sight and without interference to surface traffic, it
15
514
O
"•13
a.
it! 12
I10
29
ui
CO
cc
Q
_l
L_
6
4
Q
ASSUMPTIONS
-I.UMAX s 1.
2. DEPTH = 2 8 FT.
-3.MANIFOLD PRESSURE
HEAD * 17 FT.
4. NO FRICTION
5. ORIFICE COEFF = 1.0
•.NO COMPRESSIBILITY/
EFFECTS
i . t i i I
01234 5 6 7 8 9 10
UMAX FT/SEC
Figure 11: Approximate Horsepower Variation with Surface
Velocity
can offer positive protection against the spreading of oil (or
other surface pollutants) to undesirable areas.
Two foreign installations are known to the writer. In
Antwerp Harbor (Belgium) three pneumatic barriers (each
575 ft long) have been installed across the docks of the
Societe Industrielle Beige des Petrol (oil refinery). Their
purpose is to prevent oil spillage during loading and
unloading operations from spreading into the harbor (9). In
1968 the Yacimientos Petroleum Co. installed a pneumatic
oil containment system in the La Plata Harbor (Argentina)
to stop floating petroleum from reaching commercial and
public beaches in the area.5
CONCLUSIONS AND RECOMMENDATIONS
Based on the limited scale and range of the laboratory
tests discussed above the following conclusions and
recommendations are tentatively drawn.
1. The continual release of air below water creates a
surface current of water near the surface.
2. The magnitude of the current at the surface
decreases approximately linearly with distance from the
submerged pipe. It is a maximum at a distance of around
0.3 to 0.6 pipe depths from the pipe.
-------
NO.
i
2
3
4
5
6
7
8
9
10
II
12
13
14
TITLE
CURRENTS PRODUCED BY
AN AIR CURRENT IN DEEP
WATER
EXPERIMENTAL STUDIES OF
PNEUMATIC AND HYDRAULIC
BREAKWATERS
PNEUMATIC WAVE ATTENU-
ATION FULL SCALE TANK
TESTS
PNEUMATIC AND SIMILAR
BREAKWATERS (MODEL EXPER
USING SURFACE CURRENTS)
REDUCTION OF SALT WATER
INTRUSION THROUGH LOCKS
BY PNEUMATIC BARRIERS
BREAKING UP WAVES BY
AIR INJECTION
FIRST TESTS ETC. JAPAN-
ESE PNEUMATIC
BREAKWATER (U)
SECOND TESTS ETC. JA-
PANESE PNEUMATIC BREAK-
WATER (ffl)
ATLAS COPCO CO.
(CHALMERS UNIV - SWEDEN)
LARGE SCALE BUBBLE BREAK
WATER EXPERIMENTS-FELTHAM
PNEUMATIC BREAKWATER
WAVE EXTINCTION BY
PNEUMATIC BREAKWATER
MOBILE BREAKWATER STUDIES
LABORATORY STUDIES OF
PNEUMATIC BREAKWATERS
NOTE ' 1. (UNDER ONE ATMOS.
AUTHOR h*"™"
P S. BULSON
(SOUTHAMPTON)
STRAUB. BOWERS
TARAPORE
U. S. ARMY
TRANSPORTATION
RESEARCH COMM.
J. T. EVANS
DOCKS 8 INLAND
W W STA.
G. ABRAHAM a
P v. d. BURGH
J. 8 SCHUF
M. KURIHARA
(1955)
M. KURIHARA
(1955-56)
MR. VERNER
P S. BULSON
J. A. CHARLTON
A A. DMITRIEV
T VBONCHKOVSKAW
A.V. TEPLOV
J. H. CARR
T. M. DICK a
A. BREBNER
DOCK a HARBOR
AUTH. MAY 1961
SA.F T. R. NO. 23
AUG. 1959
TREC. T R. 60-26
DEC. I960
DOCK a HARBOR
AUTH DEC. 1955
DELFT HYD. LAB
PUB NO. 28
AUG. 1962
TRANS. WES. 1943
OCT. 1940
U. of CALIF TRANS.
AUG. 1958
U.ot CALIF TRANS.
NOV 1956
1969
DOCK a HARBOR
AUTH. OCT. 1963
BRITISH HYDRO.
RESEARCH ASS.
FEB. 1961
£.RWAVE RESEARCH
LAB. TECH. REPORT
04-10 APR. 1961
C.I.T. REPORT N-642
DEC. 1950
QUEEN'S UNI. C. E.
RESEARH REPORT
NO. 12 JULY I960
LABORATORY
OR PROTOTYPE
PROTOTYPE
LABORATORY
PROTOTYPE
LABORATORY
PROTOTYPE
LABORATORY
PROTOTYPE
PROTOTYPE
PROTOTYPE
PROTOTYPE
PROTOTYPE
LABORATORY
LABORATORY
LABORATORY
LABORATORY
H
(PIPE
DEPTH.
as. ir
25.5,34
1.0
4.5
0 TO 16
1 NTER.
3
16.5.246
310
0.73 TO U
262 TO
31.6
53.5
30 t
6,12
23'-8"B01
34
3.75 -5.0
0.8
1.1
2.75
D
(PIPE
DIAMETER,
INCHES)
6
3
H5/J6
1 I.D.
3
5
6
6
6
2
1/4 H
3/8
3/4
21/32 ID
d
(ORIFICE
DIAMETER
INCHES}
1/16, 1/8
1/4,3/6
1/8,3/6,1/4
1/4 START
11/32
1/16
1/32 H
3/64 H
1/16 (-)
5/64*1/16
M
Imm*
0.0394"«
3/64
3/8
1/4
/8, 3/8, 1/4
/I6, 1/6,1/4
1/12 (-)
0.0135
0.040
3/32
S
(ORIFICE
SPACING
/FEET)
5.1
26
37
38
30
II
15
12
2
3
2T03
4
28
12
32
24
N
(NUMBER
OF PIPE
*1ANFOLDS
USUALLY
ONE AT
A TIME
4OI2"CEN
SINGLE a
DOUBLE
ONE
ONE
ONE
ONE
ONE AT
A TIME
5 AT 15"
1 TO 9
ONE
I TO 5
ONE
Q1
(FLOWRATE
CFS/FT)
0.05
TO 1.71
.04-0.22
0.033 TO
0.78 SIN.
0.167
MAX.
[0.3 - 05)
0053 TO
0.19
0.04 TO
0.19
0.95, 1.05,
116
133 MAX.
0,14 -.5
0.001
0.03
O.I
Vr
DISCHARGE
PRESSURE)
0 TO 70.
Sptl
1422 p»ig
-57p$lg
MAX.
7 ATMOS.
AP*
2 ATMOS.
DIFF •
1/4 ATMOS
40p»i7itX)»
T
(DEPTH
OF TANK,
FEET)
6 BELOW
DATUM
1.25
6
PIPE ON
BOTTOM
IT VARIED
4
APPROX
H
I.I
50 TO
65
55
25
40
5
0.8
2.75
W
(CHANNEL
WIDTH.
FEET)
100-
150
2.0
9.0
15.0
4.0
46-83
2.4
OPEN
SEA
100 PIPE
THREE
DIMEN-
SIONAL
48
100
1.8
0.5
8
10
Table 1: Literature Survey
-------
PNEUMATIC BARRIERS . . .
391
3. The velocity generated by the bubbles decreases
approximately linearly with water depth and is a maximum
at the surface. The velocity reverses (current is zero) at a
distance below the surface which is about one-quarter of
the pipe depth.
4. The maximum surface current generated is
proportional to the unit air flowrate raised to the one-third
power. The constant of proportionality is strongly
dependent on depth of manifold pipe and practically
independent of manifold hole size.
5. The following relationship was recommended for
preliminary estimation purposes Umax = 1.5 (gq)l/3.
6. The principle of linear superposition applied to
combine stagnant Umax and channel flow velocities was
found to hold.
7. The critical failure coefficent a for stagnant water
and with currents was about 1.2. The wave conditions,
steepness, etc. influenced the a factor considerably.
8. More studies are needed to verify the apparent
entrainment of oil droplets by currents with velocities
greater than 1.6 ft/sec.
9. It is recommended that complete verification of the
above preliminary results be made under prototype
conditions.
Use of the pneumatic barrier to prevent oil spreading
on water is recommended for protected areas with low
(below 1.0 knot) currents.
REFERENCES
ITaylor, Geoffrey, 1955; "The Action of a Surface Current
Used as a Breakwater", Proceedings, Royal Society of
London Ser. A, 231, 1955.
2Sjoberg, A., and Verner, B., "Pneumatic Barriers Against
the Spreading of Oil on Water", unpublished report of
Chalmers University, Gothenburg and Atlas Copco AB,
Stockholm, Sweden, 1969.
3Unna, P. J. H., "Waves and Tidal Streams", Nature, Vol.
149, Feb. 1942,p. 219.
4Sorensen, R. M., "Wind Set-Up of Oil Slicks", ASCE
Transportation Engineering Conference, Boston,
Massachusetts, July 13-16,1970.
SBulletin Hydraulic Research 1966 and 1967, IAHR, Vol.
20, Dec. 1968, p. 43.
ACKNOWLEDGEMENT
The study was sponsored by Wilson Industries, Inc.,
under contract with the U. S. Coast Guard. Dr. John B.
Herbich, Head, Coastal and Ocean Engineering Division of
the Department of Civil Engineering was the project
director. The writer is especially indebted to graduate
students, C. McClenan and W. Son and to co-operative
student D. Stockard for their determination of the
experimental values.
The project was administered by Dr. C.H. Samson, Jr.,
Head of the Civil Engineering Department and Mr. H.
Whitmore of the Texas Engineering Experiment Station.
-------
THEORETICAL AND EXPERIMENTAL
EVALUATION OF OIL SPILL
CONTROL DEVICES1
Wilbur Marks, GuntherR. Geiss and Julius Hirshman
Poseidon Scientific Corporation
ABSTRACT
This paper describes the first phases of a program aimed
at providing a means for evaluation of existing oil contain-
ment devices (booms, barriers, etc.) and for improving basic
design through variation of geometric and physical param-
eters. A mathematical/computer model is derived that
describes the behavior (forces and motions) of a spill-
control device in given environmental conditions of wind,
current, and waves, and specified deployment configura-
tion. The results of evaluating 14 booms in terms of
probability of mechanical (structural) and spill-control
failure are discussed in general terms as are the results of
model-tank tests aimed at obtaining data for comparative
evaluation of booms and for validating and improving the
analytical model. A more definitive statement of results
awaits the completion of at-sea experiments and data
analysis which are presently being carried out.
INTRODUCTION
The problem of combatting accidental oil spills is most
vexing because it doesn't permit a unique and universal
solution. Instead, one must consider a spectrum of solu-
tions that hopefully overlap to cover the entire problem
range. Of particular interest, as a potential remedy, is the
oil containment barrier or "boom." Such a device merits
close attention because it, of all proposed remedies, in no
way endangers or even alters the environment. As a
mechanical system, the boom is introduced at the air-sea
interface where it hopefully acts to concentrate oil and is
ultimately removed presumably with no evidence of its
presence remaining.
The original concept of an oil containment boom was
deceptively simple in that the only requirements were a
The work reported here was carried out by Poseidon Scientific
Corporation, Hauppaiige, New York, under contract to the
American Petroleum Institute.
vertical wall with means of flotation and a way to hold it
fast against the spread of oil. This first generation boom
failed utterly to achieve the goal of imprisoning the spill
but, in its naivete, it functioned beautifully to define the
essence of the problem and to specify important charac-
teristics of the solution.
In stagnant water there is no problem whatsoever; logs,
for example, will do nicely to prevent the spread of oil.
However, when the surface is in motion and there is mass
transport, such as is the case when wind and/or current are
present, then the dynamics of flow around and about the
barrier is cause for more than a little concern. If, in
addition to surface flow of oil (or apart from it), there is
oscillatory motion due to waves, then the spectrum of
possible structural failure is enlarged adding to the concern
for oil escaping over the top or underneath the boom.
The first generation of oil containment booms led to the
first round of serious study of booms which, together with
some practical experience in using booms in real pills,
revealed some truisms about the oil containment problem.
It is unlikely that any one boom will be maximally effective
in all environmental conditions. The relative, motion
between the oil and the bom is a very important factor in
containment. High seas pose the greatest threat to contain-
ment operations.
Further boom development evolved from practical ex-
perience, some intuition and, in a few cases, a bit of naval
architectural design. To accelerate solution of the problem
and to provide some realistic engineering answers, programs
such as the one reported here were initiated by various
concerned organizations.
The purpose of this program is to provide a means for
evaluating oil containment devices and for improving boom
performance through basic design variation. The procedure
adopted to achieve these objectives required development
of a mathematical/computer model of forces and motions
393
-------
394 PHYSICAL REMOVAI
experienced by a boom, with given characteristics and
deployment configuration, when it is exposed to wind,
current, and waves. This model was then used to evaluate
existing oil containment devices and in the selection of
booms for scale-model testing. Scale-model tests were
subsequently carried out in ship model towing tanks to
determine mechanical and structural characteristics and oil
containment efficiency of selected booms. Data from the
model tests will be used to improve the predictive quality
of the analytical model. Finally, sea tests will provide
additional input to analytical model improvement and
critical performance evaluation.
As the model is successively improved, its potential as a
design/analysis tool for use in prescribing boom charac-
teristics as a function of mission requirements is cor-
respondingly enhanced.
As of this writing, a "first-cut" of the model is
completed as are scale model tank tests of mechanical
behavior, structural integrity and oil containment efficien-
cy. These aspects of the program will be described herein as
will some general results of a preliminary nature. A more
detailed exposition of the results of this program will be
prepared upon completion of all experimentation and data
analysis.
1HE ANALYTICAL MODEL
The analytical model was developed to meet these
specific objectives:
1) Accurately model the majority of devices under
consideration, in all likely deployment configurations, and
under all environmental conditions,
2) Produce an efficient computer program that would
calculate the probability of structural and spill control
failure for each device, as a function of deployment
configuration and environmental conditions.
As a prerequisite to development of the analytical
model, basic data on containment booms were solicited by
questionnaire to the manufacturers and distributors of SO
devices. The results thus obtained and subsequent personal
contacts produced responses on a total of 26 devices. These
responses ranged from complete engineering drawings to
somewhat vague descriptions of design characteristics. In no
case were hydrodynamic or structural data available. To
simplify the subsequent analysis and evaluation, the follow-
ing five categories of generic devices, based on physical
characteristics, were created:
I - Continuous devices with continuous flotation,
e.g., inflatable devices.
II — Continuous devices with discrete flotation, e.g.,
fabric devices with attached individual floats.
Ill - Discrete devices with discrete flotation, e.g., the
"Navy" boom.
IV - "Low tension" devices, i.e., devices in which the
main tension member is physically separated
from the device.
V — Hybrid devices, i.e., devices that embody ad-
ditional forms of spill control (filtration, bubble
barriers, and absorbents, etc.) in their design.
Formulation of the model to approximate boom be-
havior is predicated on the following assumptions: 1) the
devices may be represented by a chain of rigid segments
interconnected by flexible couplings; 2) the motion of the
rigid segments may be described by linear ship motion
theory; 3) the entire device behaves linearly, i.e., the overall
behavior is the sum of the effects due to each individual
cause; 4) the most significant motions are roll, pitch, and
heave; and 5) containment effectiveness can be represented
by a device's motion with respect to the water (i.e.,
submergence and emergence).
The first assumption reduces the describing equations to
a set of ordinary differential equations thereby simplifying
the analysis; the second enables the use of a solid body of
hydrodynamic theory for the development of these equa-
tions. Assumption three simplifies the computation most
significantly by permitting use of harmonic response theory
and spectral analysis while recognizing that the current
state of the art does not warrant a more complex model.
The fourth assumption reduces the complexity of the
model by ignoring three degrees of freedom. The three
motions that are retained are directly related to reducing
the device's effective draft and freeboard and resulting spill
control effectiveness. The last assumption emphasizes the
naive state of our understanding of the behavior of two
fluids dynamically interacting with a barrier. The net result
of these assumptions is a model capable of describing the
devices in categories I and II by approximation, the devices
in category III directly, and the devices in categories IV and
V partially.
The comparative evaluation of devices for selection of
candidates for model towing tank tests is based on
computational experiments involving a variation of boom
configurations and environmental inputs. The results are
developed into a rank ordering of device effectiveness based
first on structural integrity and secondly on spill control
efficiency. Clearly a device that fails to survive in given
wind/waves/current is of no spill-control value under those
environmental conditions.
The spill control device model is validated by com-
parison of its predicted behavior with measurements of
scale-model behavior in a towing tank and measurements of
full scale device behavior at sea. The experimental measure-
ments include motions, tow-line tension, deployment con-
figuration and oil containment effectiveness. In addition,
qualitative observations are made on emergence-
subemergence, oil behavior, and device handling qualities.
THE MODEL
The model of oil spill control device motions and forces
is composed of a steady state part and a dynamic part. The
steady state part describes the forces, deployment con-
figuration, and device attitude in the absence of waves; the
dynamic part describes the dynamic forces and motions in
response to a prescribed sea state. The assumption of
linearity permits addition of the separate contribution of
the steady state and dynamic parts.
-------
EVALUATION OF CONTROL DEVICES 395
I 1NE
©VEND
© y MIDH
NUMBER OF SEGMENTS (FIRST BEGINS
ATP)
SEGMENT LENGTH
X COORDINATE OF END POINT
Y COORDINATE OF END POINT
Y COORDINATE AT X END/2
7 WIND FACTOR
(CAUSING EFFECTIVE CURRENT)
B DRAG FACTOR
(FOR TANGENTIAL DRAG)
N
\
\
\
\
\
\
\
\
\
X END/2
XENDfS)
Figure 1: Configuration Data
Based on the analogy to a towed neutrally buoyant
cable, the boom configuration is assumed to be parabolic
(Figure 1). This eliminates complex calculations of con-
figuration which are unwarranted since the desired quanti-
ties, heel angle (rotation of the plane of the device from the
normal to the water surface) and tension, are relatively
insensitive to configuration.
The calculation of steady state forces is based on the
assumption that the effects of wind, wind induced current,
sea current and towing velocity are additive. In fact, the
latter three are added vectorially to produce a net effective
current used in calculating current forces (Figure 2). The
This .configuration is chosen to be
y =
(i)
where
4YMIDH ' YEND
END
C2 =
2Y
END
4Y
MIDH
X'
END
are
A list of Notation that describes the symbols in the equations is
found at the end of the text.
defined in Figure I.2 Note that the device may lie
anywhere on the parabolic arc thus allowing a wide variety
of configurations. The input parameters are selected by
experience and verified by comparing the calculated total
force normal to each rigid segment with the calculated
component of tension normal to that segment.
segments are assumed to be small enough to be without
curvature and flat plate viscous drag formulas are used. The
components of drag force normal and tangential to a
particular segment (number j) are given by
(4)
and
(5)
respectively, where Ci is the drag coefficient (taken as
2.0), A is the area projected to the fluid flow, p is the mass
density of the fluid (air or water), U is the fluid speed
relative to the device, "yy is the angle between the segment /
and the relative fluid velocity, and V is an experimentally
determined coefficient taken as 0.02. These forces are
-------
396 PHYSICAL REMOVAL
calculated for the wind and the net effective water current
separately.
The heel angle 0 is given by the relation
a
sn
WG
(6)
M
where Affl is the applied moment, W is the segment weight
and C is the metacentric height given by
+ G • B
(7)
where I^wp) is the moment of inertia of the waterplane
area about its longitudinal axis, G and B are the distances of
the center of gravity and center of buoyancy below the
waterline, and a is the segment displaced-volume. This
formulation ignores resistance to heel due to ring stiffness
induced by the curved deployment.
The moment^/ is
cos
(8)
YfljTj/1) - X(l)Tyfl) -
X(n+l)Ty(n+l) = -M
+ T
yfl) = 0
(10)
where n+1 is the last joint, !*„ Tv are the x and y
•* y
components of tension, F and F are the components of
•* y
the vector sum of forces on the segments, and similarly, M
is the net moment on the device. The tension components
at any joint are calculated from those at the preceding
joint, i.e.,
+ 1) = Tjn - FP(i) sin 5(j) + pP(j) cos Sfj)
Tyfj +1) = TJj) + Ft>(j) cos S(f) + FP(f) sin 6(j)
Jv 1
T(j + 1) = (T2(j +1) + T2(j +1))1/2
(11)
where PP and F? are the forces equilibrated by tension, i.e.,
where Fi", and F~~ are the normal components of wind and
J\ N
current force, d is the draft, h is the freeboard, and e is the
distance of the structural center below the waterline. The
cosine term accounts for the reduction of projected area
due to heeling. Thus, by combining Eqs. (6) and (8), heel is
determined by
tan =
WG
'M
(9)
In the case of devices with little freeboard or effective sail
area, e.g., a cylindrical float and a flexible skirt, the heel of
only the "skirt is calculated, and thus Gj^ is calculated for
the skirt only and F^ is set to zero in Eqs. (8) and (9).
N
However, the flexibility of the skirt is not accounted for,
i.e., ballooning of the skirt is not considered.
The calculation of static tension is based on three
equations of equilibrium and the requirement that the ratio
of tension components at joint 1 (the left end point of
segments n in Figure 1 .) be equal to the slope of the curve
at that point, i.e.,
- Tyfn+1) = Fx
Ty(l)-Ty(n+l) = Fy
=
pP = (FC+FW)
T N N
+ TFWsin2
N
(12)
The parameter T takes the value 1 for a flexible skirt and
the value 0 for a rigid skirt and 8(j) is the angle of the
segment with the X axis.
This completes the description of the steady state part
of the model which is relatively simple and computationally
efficient. The inputs to this part of the model are: the
wind, current and towing velocities, the device parameters,
and the configuration parameters. The outputs are: the
tension at each joint, the heel angle of each segment, and
the check force at each segment for checking the chosen
configuration input parameters.
The dynamic part of the model describes the device
response to regular and irregular waves and depends on the
calculations of the steady state part. The assumptions made
here are: 1) yaw, surge and sway motions are negligible; 2)
tension variations due to waves are negligibly small com-
pared to the static tension; 3) the rigid segments are
uniform in the longitudinal direction; 4) the segment length
(or sum of segment lengths for very closely coupled
segments) is much larger than the transverse dimensions; 5)
the transverse dimension is smaller than the smallest
wavelength; 6) roll is uncoupled from sway and yaw; 7)
oblique waves can be effectively decomposed into head and
beam waves; and 8) small angle approximations are ap-
-------
EVALUATION OF CONTROL DEVICES 397
plicable. The assumptions 3) through 8) are the normal
assumptions of linear ship motion theory. Assumption 1) is
made to simplify the model and 2) is made to maintain
linearity.
The dynamic portion of the model is too lengthy to
detail here so only some of the salient features of the pitch
and heave portion will be described. The roll portion of the
model follows essentially a parallel development.
The pitch, 6, and heave, z of segment / in response to a
sinusoidal wave of amplitude a and radian frequency oo are
given by
j) + B'z(j) + Cz(i) =
(13)
where V(j) and M(j) are the vertical shear force and
moment at joint /, F(j) and M(j) are the complex driving
force and moment on segment / due to a wave of frequency
to, the real part of the solution is understood throughout,
and a dot or double dot above a quantity indicates first and
second time derivatives respectively. The coefficients are
related to the rigid segment length, a, water line width, b,
two dimensional added mass, m, and damping, n, by
A' = ma, B' = na,C' =
n _ "W5 F _ "a3 r'
D-iT>E-^2' G
the driving force, F, and moment, M, are given by
a^
F(j) = ae'ksdfpwgb - u?m + iun] I f1
J dL
(14)
dx
M(j) = -ae'^p^fe - co2™ + /con/ I
xe 1 dx (15)
-a
2
where a is the wave amplitude, k is the wave number (—£•)•
c*r
ki = k cos fy' and /?• is the angle between the sea and the
normal to the segment /, s is the sectional area coefficient, b
is the sectional beam, and d is the sectional draft.
The solution of the system of Eqs. (13) is implemented
by the use of state vectors and matrix algebra. The state
vectors Rfj) are defined at each joint / of a segment or
coupling and have components: ^-vertical displacement,
0-pitch angle, F-vertical shear, and M-moment. This for-
mulation readily permits differences in orientation to the
sea between segments, different end conditions (fixed to
barge, tow line, etc.), various forms of segment couplings
(See Figure 3 for typical model), the inclusion of different
segments (moorings, barges, skimmers, etc.) and only part
of a device to be examined. The state vector R defined
above obeys
R(j+D = URfj
(16)
where only end forces are considered and a matrix {/.-
relates one end of a specific segment or coupling to the
other. By adding a unit component to the state vectotR(j),
create R(j), thus including the distributed loads (wave
forcing terms) i.e.,
U- W, .
(17)
Eq. (17) is derived from the system of Eq. (13) for the
rigid or first order equations describing the coupling, where
the quantities are complex and vector W- contains the
forcing terms F" and M"'. By repeated multiplication by
Up which varies with segment number,3 one relates the
state variables at one end of the device to those at the
other, i.e.,
R(n) = Un.... UjR(l) = PRfl)
(18)
Two of the four state variables are specified at each end of
the device according to the physical constraints at the ends;
that puts Eq. (18) into the form of a two-point boundary
value problem that must be solved for the remaining four
state variables. This can be done by partitioning, but for
long booms numerical problems arise so a more sophisticat-
ed technique is used. That then completes the determina-
tion of the response of the end points to a sinusoidal wave.
The response of any other point in the chain is obtained by
using Eq. (17) repeatedly.
By dividing the amplitude of a given response by the
wave amplitude, a, the unit sinusoidal response (Response
Amplitude Operator) is obtained for that wave frequency
CO. By repeating the entire process at many frequencies oo
One can either consider both rigid segments and couplings as
segments or define a segment as a rigid segment plus one flexible
coupling. (See Figure 3).
-------
398 PHYSICAL REMOVAL . .
the pitch and heave RAO's, H^iu) and
obtained for each segment.
are COMPUTATIONAL EVALUATION OF DEVICES
The response of a particular variable to an irregular
unidirectional sea is then given in terms of its power
spectrum $ e.g.,
where
is the Pierson-Moskowitz wave spectrum
O.OOSlg2 I -33-56h 1
_5 exp\—T-
Ur \ CO
0
(20)
corresponding to the specified sea state with significant
wave height hj /j. Then, for example, the probability that
the heave amplitude, qjj), at joint/ exceeds magnitude Q is
given by
(21)
where
(22)
and to£, o^ are the limits of the frequency band in which
significant motion occurs. By similarly deriving the RAO
for heave relative to the water surface, Eq. (21) will yield
the probability of emergence and submergence when Q is
the freeboard and draft, respectively. Similarly, by relating
the stress in a given structural member to the forces and
moments the probability of failure of that member is
derived by setting Q equal to the limiting stress.
To sum up, the model described above has the following
important features: 1) calculation of statistics of forces and
motions for oil spill control devices in an irregular sea
including probability of structural and elementary spill
control failure; 2) analysis of both continuous and discrete
devices in arbitrary deployment configurations and environ-
mental conditions; 3) ability to readily represent parts of
devices or combinations of devices; and 4) computational
efficiency largely as a result of the simplicity of the steady
state portion of the model. The model does not account for
interaction of the device with oil on the water (i.e., the
fluid mechanics), devices based on other than mechanical
obstruction of oil spread, or devices that are relatively
wide. Future research will expand the model in these
directions.
Of the 26 devices for which data were received 14 were
analyzed using the model described herein. Twelve devices
were eliminated because of lack of design data, or similarity
to other devices, or inability of the math model to describe
the system. The numerical calculations were carried out for
a moderate environment comprising a state 3 sea (signifi-
cant wave height 2.9 feet), 13 knot wind and 0.6 knot
current. The deployment configuration was symmetric, i.e.,
U-shaped, and the waves, wind, and current were directed"
along the line of symmetry of the configuration. The
following general results are noted:
1) Eight of the devices exhibited heel angles greater
than 30°. These were largely in Categories I and II.
2) Three devices were found to have excessive motion
relative to the sea surface, i.e., poor following charac-
teristics.
TOW SPEED (7)
AND DIRECTION ©
WIND SPEED © AND DIRECTION ®
CURRENT SPEED © AND 0 DIRECTION
SEA DIRECTION ©
S SIGNIFICANT _
WAVE HEIGHT (T)
O.O3W+C+T « EC. EFFECTIVE CURRENT
WHERE T« TOW VELOCITY
Figure 2: Seaway Data
-------
EVALUATION OF CONTROL DEVICES 399
3) One device exhibited a static stress above its estimat-
ed safe stress.
4) Three devices showed a high probability of failure
due to dynamic loads.
The wide variety of behavior exhibited within a given
category does not permit generalizations to be made on the
performance of devices within generic categories. The only
specific comment that can be made is that excessive heel
angles were primarily observed in devices with flexible
skirts. This may be due to treating them as relatively rigid
skirts (e.g., no allownace for ballooning) and the lack of
ring stiffness effects in the model.
The work reported here comprises an initial attempt to
mathematically describe spill control device behavior. It is
expected that the model will ultimately be improved by
added mathematical sophistication and by incorporation of
data developed via model tests and sea trials.
THE MODEL TANK EXPERIMENTS
Mechanical Behavior
and Structural Integrity
Motion and force studies on a number of booms were
carried out in the ship model towing tank of the Webb
Institute of Naval Architecture. The tank is 100 feet long, 8
feet wide and 5 feet deep. There is a wavemaker at one end
and a beach at the other. A towing carriage is used to pull
the model through the water. In these experiments, towed
motion of the barrier device through the water may be
viewed either as its motion or the flow of a current or a
combination of both those vectors. Five different booms
were tested; three at a scale ratio of 1:5, one at 1:6 and one
at 1:9. Physical scaling of the booms was a particularly
difficult problem, because the laws that were applied were
not fully developed for this particular use. Indeed, some
models could not be properly scaled, so not all of the
generic classes were tested. The scale used was often
determined by the physical characteristics of available
modeling materials which explains the difference in scale
ratios for different models.
During the tests, a variety of towing speeds were used to
simulate a range of current up to 4 knots. Regular waves
with variable heights were used to obtain response am-
plitude operators (RAO) and some tests in irregular wave
systems were also run. The models were deployed in
different orientations to the waves and current.
The measurement system was primarily photo-optical,
because scaling prohibited attachment of measurement
devices to the booms. The photo-optical system was used to
record motions. In addition, force gages in the mooring
lines recorded towing forces. Waves were recorded with
both stationary and moving (on the tow carriage) wave
wires. Towing speed is accurately calculated by means of
relay-activated precision timing over measured courses.
Figure 4 shows the test system used in these experiments.
WATER LINE-
d- DRAFT
h- FREEBOARD
e- WATER LINE TO CABLE
DISTANCE
a- RIGID SEGMENT LENGTH
s- FLEXIBLE SEGMENT LENGTH
H'-RESTORING FORCE
H*- RESTORING MOMENT
Figure 3: Structural Data - Appropriate to Single Section of "Navy Boom'
-------
400 PHYSICAL REMOVAL .
Over a two-week period, approximately 400 tests were
carried out under systematically varied conditions of
current, waves, and deployment configuration. The data are
now being analyzed, but the following general observations
are believed to apply:
Different booms within the same generic category
exhibited wide variations in behavior while some
booms in different categories behaved equally well.
This appears to result primarily from engineering
design practice.
2. Loose skirts have little effect on performance even at
moderate tow speeds (currents). On the other hand,
fabric devices do exhibit rigidity due to ring stiffness.
Therefore, ring stiffness and ballooning are important
factors in boom design and may not be ignored as
was done in the development of the analytical model.
3. Booms with low beam/draft ratios (fabric booms
particularly) are prone to exhibit planning and poor
stability in moderate to high currents.
4. The effect of sway becomes important in longer
period waves.
Figure 4: Layout of Model Tank Testing System for Studying
Forces and Motions (1. Model Test Tank; 2. Tank Wall; Direction of
Tow, Current and Waves in Opposite Direction; 4. Towing and
Instrumentation Carriage; 5. Model of Oil Spill Control Device;
Water-Level Orthogonal Super 8-MM Movie Camera; 7. Overhead
3S-MM Still Camera; 8. Force Transducer; 9. Moving Wave Wire; 10.
Data Cards and Frame Counters; 11. Oscillograph Recorder for
Waves, Forces, and Test Parameters; 12. Oscilloscope — Camera
Synchronism Check.)
-------
EVALUATION OF CONTROL DEVICES 401
5. Nonlinear effects were observed, particularly at
higher currents and steeper waves. It is not clear how
important this is in prediction of boom behavior, but
the matter must be reconciled.
OIL CONTAINMENT EFFICIENCY
This phase of testing was carried out in the Davidson
Laboratory towing tank (300' x 12' x 5') of Stevens
Institute of Technology.
The oil-containment experimental system (Figure 5)
comprised of the following elements:
a) The oil metering system that pumped oil into the
water at a constant rate at prescribed times.
b) The boom tow-system that simulated the combina-
tion of towing and current and measured the resultant force
in the tow line.
c) The camera system along with the tow-force and
wave recorders comprised the entire data acquisition
system. There were 4 cameras in the system: 1) a
wide-angle super-8 movie camera to record action on the
surface, 2) a 16-mm movie camera mounted on a 90°-view
periscope to film underwater action, 3) a hand held super 8
movie camera to film operational aspects and special angles,
and 4) a motor-driven 35-mm still camera to record boom
shape and oil flow.
d) The weir towed behind the boom to capture and
hold oil that might elude the boom.
e) Two blowers used to "wind-sweep" the tank to
concentrate oil for cleanup purposes.
f) A recording oscillograph to record boom tensions.
g) Two underwater curtains that were raised at the end
of each run to trap the test boom and the oil it is
containing.
Figure 5: Layout of Test System for Oil Containment Experiments
(1. Test Tank; 2. Test Boom; 3. Test Oil; 4. Oil Applicator; 5. "Y"
Valve for Controlling Oil Flow; 6. Oil Makeup Tank; 7. Metering
Pump with Controlled Speed Motor; 8. Oil Collection Wier; 9.
Escaped Oil; 10. Super 8-MM Still Camera for Overhead Viewing;
12. 16-MM Movie Camera for Underwater Viewing; 13. Underwater
"90°" Periscope with Mirror; 14. Synchronized Clocks (one in
Underwater Housing); 15. Oscillograph Recorder; 16. Force
Transducer; 17. Oil Cleanup Fans.)
-------
402 PHYSICAL REMOVAI
A total of 22 tests were run; each test required from one
to three hours of preparation. The same five booms were
tested in a variety of currents and waves. Oil samples were
taken for chemical analysis. Preliminary examination of the
data reveals that new information concerning boom be-
havior has been obtained. Some unverified observations are:
1) The results of Wicks describing the behavior of oil
flow near a barrier in a current appear to be generally
supported by the test series run in current alone,
2) Sway, ring stiffness, and planing (diving) appear to
be important factors in oil loss in waves and current,
3) Each different type of boom failed for a different
reason in the wave tests.
4) A boom that successfully held oil most of the time in
a relatively high sea state and current failed upon inter-
action with an exceptionally large wave.
5) The importance of the oil's characteristics was clearly
demonstrated when, under identical current conditions, the
boom contained No. 2 fuel oil and the industrial lube oils
effectively while it failed utterly to contain No. 4 oil.
SUMMARY
Perhaps the most important result to emanate from this
and other like studies is a reassessment of technical
objectives. For example, it was recognized, even before this
work was undertaken, that if the oil is propelled in a
current of sufficient magnitude no conventional boom can
hold it. Now, it is seen that as booms are used to control or
divert oil, rather than contain, there is a limit to the
amount of oil that can be handled under specific con-
ditions. The tendency is to consider booms in combination
with removal devices for maximum effectiveness.
New ideas for boom configurations are beginning to
proliferate. The reason is obvious; no single boom can
effectively function in all environmental conditions. The
tests reported here have shown that different designs solve
different problems. Of the five booms that were model-
tested, almost all failed for different reasons. However,
when cost-effectiveness and ease of handling are included as
criteria, some of the poorer performers may be considered
to be more attractive than the better performers for a
specific mission.
There is beginning to appear a more realistic acknowl-
edgment of the scope of the problem. At the ends of the
spectrum of understanding are stagnant water and high seas.
In the former, virtually any remedy will suffice; in the
latter, there is no known remedy. In between reside the
bulk of realistic environmental conditions and it is here that
solutions should be and are being sought.
Once it is established that booms will continue to be
useful and that ultimately a "family" of booms for all
occasions should be developed, then the importance of
mathematical modeling and tank experimentation begin to
emerge. There is no more efficient way (time and cost) to
examine booms and to evaluate design changes than
through mathematical modeling provided, of course, the
model is representative of the real physical world it
purports to describe. The model tank is an excellent
medium for validating predictions of the analytical model
and for proving performance. The same applies to at-sea
testing where final designs receive their baptism of fire.
What is probably needed for the long haul is a standard
model tank and at-sea test facility and procedure so that all
prospective booms can receive uniform evaluation.
LIST OF SYMBOLS
- area projected to the fluid flow
— added mass coefficient in heave equation
— rigid segment length
~ a statistic of sea spectrum
— distance of the center of buoyancy below the
waterline
— damping coefficient in heave equation
- waterline width, sectional beam
— restoring force coefficient in heave equation
- drag coefficient (taken as 2.0)
~ constant in configuration equation
- constant in configuration equation
- added moment of inertia coefficient in pitch
equation
— draft, sectional draft
E — damping coefficient in pitch equation
E i • i — "energy" of spectrum for variable q(j)
A
A'
a
a j /?
B
B1
b
C'
CA
D
-------
EVALUATION OF CONTROL DEVICES 403
G'
distance of the structural center below the
waterline
complex driving force on segment/
normal component of current force
normal component of force equilibrated by
tension
tangential component of force equilibrated by
tension
normal component of wind force
normal force on segment /
tangential force on segment/
x component of vector sum of forces on the
segments
y component of vector sum of forces on the
segments
distance of the center of gravity below the
waterline
restoring coefficient in pitch equation
metacentric height
gravitational acceleration
heave Response Amplitude Operator
pitch Response Amplitude Operator
freeboard
significant wave height
pitch moment of inertia
moment of inertia of the water plane area
about its longitudinal axis
M
M
m
n
n+1
P
Q
— index used for segment or joint number
T
7L
T
y
u
ui
— wave number
- apparent wave number due to oblique sea
- mass of rigid segment
- applied moment
— complex driving moment on segment /
- moment at joint/
— two dimensional added mass
— damping factor
- last joint
— matrix that relates motions and loads at one
end of boom to those at the other end
_ parameter of probability distribution
— vertical displacement component of state vector
RfiJ
— heave amplitude at joint/
— state vectors defined at each joint / of a
segment or coupling with components, q, 6, V
and M.
— state vector Rfj) plus a unit component
- sectional area coefficient
— tension
— x component of tension
— y component of tension
— time
— fluid speed relative to the device
- a matrix relating motions and loads at one end
of a specific segment or coupling to those at its
other end
-------
404 PHYSICAL REMOVAL . . .
V
V(i)
w
Wl
XEND
vertical shear component of state vector R(j)
vertical shear force at joint/
segment weight
part of U- containing forcing terms Ffj) and
— coordinate in waterplane
- input quantity (defined in Fig. 1)
— coordinate in waterplane
- input quantity (defined in Fig. 1)
— input quantity (defined in Fig. 1)
— heave motion of a segment
— amplitude of a sinusoidal wave
— angle between sea and the normal to segment/
- angle between the segment / and the relative
fluid velocity
P
Pw
T
CO
— pitch angle, pitch angle component of state
vector/ty/;
— experimentally determined coefficient (taken as
0.02)
— mass density of the fluid (air or water)
— mass density of water
— coefficient (takes the value of 1 for a flexible
skirt and 0 for a rigid skirt)
- power spectrum of the response of a particular
variable to an irregular unidirectional sea
— power spectrum of variable q(j)
— Pierson-Moskowitz sea spectrum
— heel angle
_ radian frequency of a sinusoidal wave
_ limits of the frequency band in which sig-
nificant motion occurs
— segment displacement volume
d
dt
-, derivative with respect to time
Sfj} — angle of the segment / with the X axis
-------
STUDY OF EQUIPMENT AND METHODS
FOR REMOVING OR DISPERSING OIL
FROM OPEN WATERS
C.H. Henager, P.C. Walkup,
J.R. Blacklaw and J.D. Smith
Pacific Northwest Laboratories,
Batelle Memorial Institute
Richldnd, Washington
ABSTRACT
A cost effectiveness analysis was performed for
equipment, materials and techniques applicable to the
removal or dispersal of spilled oil from U.S. Navy oilers and
gasoline tankers on open waters. Effectiveness parameters
included oil product types (JP-5, Distillate Fule, Navy
Special and Bunker C), a range of spill locations (3 and 12
miles from shore) and varying spill sizes (2,700 gal, 270,000
gal, and 6,750,000 gal). Criteria for evaluation of systems
under the above parameter situations, formulated for
presently available equipment and materials, included:
completeness of oil removal; rate of removal; hazard and
pollution; use in limited access areas; sensitivity to expected
environmental factors; sensitivity to temperature extremes;
toxicity to marine life; and system availability. Cost
effectiveness was determined using the 3 spill sizes and
checked for spill frequency sensitivity, The three most cost
effective systems for the range of spill sizes were found to
be burning, dispersing, and mechanical skimming.
Considering system applicability to avrious products and
the requirements of rate of removal for massive spills, the
most practical universal system with a favorable cost
effectiveness ratio was found to be dispersing. This is
followed by dispersing phis a containment boom. Burning
agents applied directly to the spill were judged to be the
third best system based on its favorable cost effectiveness
but limited applicability to oil types and permissible
burning circumstances.
INTRODUCTION
A variety of equipment, materials, and techniques have
been used to remove spilled petroleum products from open
waters. The range of credible spill situations and petroleum
products with high potential involvement suggests that no
single system is likely to be completely effective. This study
was performed to identify and describe the most
cost-effective available systems consisting of present or new
combinations of existing equipment, materials, and
techniques. It was also intended to identify present
deficiencies and recommend specific measures for future
employment by the Navy to combat spills on open waters
in close proximity to valued resources. Consideration of
costs, effectiveness, speed, hazards, ecological effects,
environmental and geographic factors, and other
constraints are included. The study focuses on the major
petroleum products in current use by the Navy or planned
for future use. These products are Bunker C, Navy Special,
JP-5 and Distillate Fuel. This study was performed under
contract N62399-70-C-0008 to the U. S. Navy. The Naval
Civil Engineering Laboratory at Port Hueneme, California,
was the contracting agency and the Supervisor of Salvage,
Naval Ship Systems Command was the sponsoring agency.
A rational decision-making methodology developed for
a prior studyO) was employed for choosing among
alternative countermeasures against petroleum product
spills from Naval oilers and gasoline tankers. The study
encompassed detailed analysis of the effects and behavior
of spilled oil, state-of-art study of available materials and
methods, and detailed review of representative spills. This
presentation will be confined to the effectiveness analysis
and its results.
The principal ingredient of the decision-making
methodology is an effectiveness analysis.
405
-------
406 PHYSICAL REMOVAI
EFFECTIVENESS ANALYSIS
Analysis of the effectiveness of systems for removal of
petroleum product spills from open water surfaces
requires assessment of operational aspects under a range of
conditions. These conditions are parameters whose
extremes are the boundaries for the assessment.
"Effectiveness" is not quantifiable unless specific
characteristics which contribute to or detract from the
overall effectiveness are considered. The identification of
such characteristics, criteria for judging them, and a rational
plan for combining them into overall effectiveness follow.
Effectiveness Parameters
Effectiveness analysis involves assessment of each
candidate system with respect to all effectiveness criteria
over a range of conditions. These conditions may properly
be called "parameters." They are the expected
characteristics of spill incidents, the geographic and
physical characteristics of spill sites, and the environmental
conditions at spill sites. The parameters developed here are
hypothetical and it is believed that they represent a realistic
open sea situation. Representative ranges for these aspects
were derived from available historical information and
descriptive materials. The parameters selected for this
study, and the rationale for their development, are given in
the following paragraphs.
Size of Spill
The size of spills from Navy oilers and gasoline tankers
can range from minor fuel handling incidents involving a
few hundred gallons to a major incident where several
compartments or a complete vessel are Involved.
For purposes of this study, incidents were classified
into three representative size ranges: 2,700 gallons (10
tons), 270,000 gallons (1,000 tons), and 6,750,000 gallons
(25,000 tons). These spill sizes represent: either (1) minor
damage or personnel error, (2) the rupture of a large tank
or several small tanks, or (3) the catastrophic loss of the
total oil capacity of a Naval Oiler.
Location of Spills
The proximity of a maritime casualty to valuable shore
and near-shore resources can have considerable significance.
The spreading and influence of wind and waves can put the
oil into a beach in a short time if the incident is close to
land. The time available for spill cleanup is a direct function
of the spill location and local hydrographic and
meteorologic environment. Most spillage of significant size
is a result of collision, groundings or adverse weather. The
probability of each of these cases is enhanced the closer the
vessel is to land. Two locations were chosen for use in this
analysis: three miles from shore and twelve miles from
shore. Mid-ocean spills were not chosen for study cases
because the spreading and dispersal of oil spills by wind and
waves take place so rapidly that by the time clean-up
equipment would arrive at a mid-ocean spill, it would be
impractical if not impossible to locate and treat the widely
spread oil slicks.
Frequency of Spillages
The frequency of spillage is important because of the
effect of frequency upon system properties, i.e.,
maintenance, maneuverability, and fixed versus variable
costs. Clean-up costs per gallon of spillage will be quite high
if a very few spills are encountered.
Spill frequencies of the incidents described previously
can only be implied. The maritime casualty record of U. S.
registered vessels worldwide and foreign vessels in U. S.
waters for 1966 and 1967(2) were usedto approximate spill
frequencies.
These data suggest that, with approximately forty
oilers and gasoline tankers worldwide, ten 270,000 gallon
spills and one 6,750,000 gallon spill might be expected per
year, exclusive of war-time casualties. The number of
minor, or 2,700 gallon spills, is not estimated, there being
no data on which to base an estimate. However, the
frequency of the small spills has been considered in the cost
analysis by varying the frequency to determine the effect.
Effectiveness Criteria
The criteria for the effectiveness measurement should
minimize the subjective judgment which must be employed.
Rather than attempt to finely rank each system with
respect to the criteria, which would inject undesirable
subjective judgment into the analysis, we have chosen to
establish the individual criteria in terms of minimal
performance requirements. Each system is then given a
numerical index which reflects whether it exceeds, meets,
or fails to meet each of the criteria. The sum of these
indices, for all combinations of parameters, then reflects
the overall relative effectiveness of a particular system
The effectiveness criteria employed in this study are
listed in Table 1. The rationale- for their development
follows:
Table 1. Effectiveness Criteria
Operational Aspect
Completeness of
Removal
Rate of Removal
Does Not Increase
Pollution 01 Hazard
Completeness of Removal Essentially
complete removal in consideration of
environmental, geographic, and
hydrographic parameters.
Recovery at a rate such that removal
from surface waters is complete
before a slick contacts valued shore
resources. Includes deployability and
mobility considerations.
Must not produce a situation having a
higher pollution hazard or lower
safety potential than the
contaminating petroleum product
alone. Primarily applicable to
chemical or chemomechanical
methods.
-------
EQUIPMENT AND METHODS
407
Applicability to
Limited Access Areas
Sensitivity to Natural
Phenomena or Floating
Debris
Toxicity to Marine Life
Availability
Sensitivity to
Temperature
Must be capable of operation
adjacent to ship salvage and shallow
water areas which may limit access.
Judgment based on maneuverability
and size.
Must be capable of operating under
the anticipated sea, wind and current
conditions prevailing at spill scenes
90% of the time. Must not be
rendered inoperable by minor
floating debris or, where applicable,
by water-in-oil emulsions.
Will not contaminate fisheries and
other commercially or recreationally
significant marine life to cause
mortality, condemnation of fish
products, or flavor degradation.
Will be available for application at
least 95% of the time in
consideration of reliability,
repairability, and level of skill
required of candidate systems.2
Must be capable Qof operating at
temperatures of 40°F, i.e., must not
be rendered inoperable by
temperatures in the 40-50 F range.
Completeness of Oil Removal
Any system worthy of consideration must be
theoretically capable of at least 90% complete removal of
the spilled product from the water surface. Some systems,
especially mechanical ones, can not be expected to do this
under adverse combinations of environmental, geographic,
or hydrographic parameters considered in this study.
Each system was evaluated for the combinations of
parameters involved in this study, by considering its design
features which detract from or contribute to the
completeness of petroleum product removal. Those which
are capable of providing 90% or greater removal were given
an index of (+2) and those which have severe limitations in
this regard (less than 50%) were given an index of (0).
Those which appear theoretically capable of 90% removal
performance, but are undemonstrated for the particular
combination of parameters involved, were given an index of
+1.
Rate of Removal
A measure of the effectiveness of an oil spill
countermeasure is its ability to contain or remove the
spilled material before it damages vulnerable property or
marine life. Removal must be effected before a slick
becomes so thin that it is untreatable or unrecoverable.
Where the wind conditions are calm and currents are
not significant, the ra'te of movement of the edge of a slick
will be controlled by the spreading rate. No directly
applicable quantitative data on spreading rates for the
materials of concern (JP-5 , Navy Special, Bunker C, and
Distillate Fuel) have been found. However, the work of
Blokker and Berridge, et al(3,4) provides some basis for
estimation of rates of oil slick spreading. Calculated slick
characteristics based on these works are shown in Table 2.
The Blokker equation can be stated as,
K(dw-d0)
where
D =
iw,d0
V,
o
t =
DO =
K =
slick diameter, meters
density of water and oil, respectively
volume of oil, cubic meters
time after spillage, minutes
slick diameter at t=0
a constant depending on the oil.
The density of Bunker C can be greater than that of sea
water; therefore, Bunker C will have little tendency to
spread. In addition, the pour point of Bunker C will
usually be above the temperature of the sea water. This will
further inhibit spreading. Bunker C will not be expected to
spread to less than 2 cm thickness.
Table 2. Theoretical Slick Dimensions After Spill
2.700 gal Spill
270,000 gal Spill
6,750,000 gal Spill
JP.-5 and
Distillate
Fuel
Navy
Special
Bunker C
Time After
Spill
1 !iin.
10 Min.
1 Hr.
2 Hr.
5 Hr.
10 Kr.
1 Min.
10 flin.
1 Kr.
2 Hr.
5 Hr.
10 Hr.
Thickness
(In. x 10-2)
79
3.64
1.01
.65
.35
.22
79
6.15
1.74
1.09
0.60
0,38
Area
(Ft.2 x 106)
.004
.11
.394
.62
1.14
1.82
.004
.065
.23
.366
.668
1.06
Thickness
(In. x 10-2)
79
16.9
4.8
3.0
1.63
1.03
79
28.7
8.25
5.18
2.79
1.72
Area
(Ft.2 x 106)
0.4
2.35
8.24
13.2
24.3
38.5
0.4
1.38
4.8
7.65
14.2
22.4
Thickness
(In. x 10~2)
79
37.5
13.4
8.6
4.72
2.38
79
51.5
21.6
14.3
7.92
5.23
Area
(Ft.2 x 106)
10.0
26.4
73.9
115.0
210
416
10.0
19.2
45.8
69.4
125
189
10 Hr.
79
.004
79
0.4
79
10.0
-------
408 PHYSICAL REMOVAI
Values of K for the petroleum products of interest in
this study have not been determined. However, Blokker has
determined this constant for several refined products, some
of which resemble JP-5, Navy Special, and Distillate Fuel.
The JP-5 and Distillate Fuel have similar densities and
viscosities and closely correspond to Blokker's gas oil (Sp.
Gr. = 0.83,11 = 4.3 cP at 20°C). Navy Special is similar to
the lubricating oil tested (Sp. Gr.=0.90,/i=490cP at 20°C).
The values of K, for these materials, were 15,000 min'1 and
9,800 min-1, respectively, and were used herein.
According to Berridge, the thickness of a slick, after
the lapse of a full day, tends to approach the same value
(0.0008 to 0.0012 in. in their reported tests) for a group of
oils covering a wide range of properties. It is probable that
the JP-5, Distillate Fuel, and Navy Special would all exhibit
this characteristic.
The required recovery rate, within the previous
context, revolves about the ability of a system to treat a
given water surface area within a specified time span.
Effectiveness criterion is best expressed for rapidly
spreading materials as area treated per unit time. For slowly
spreading materials such as Bunker C, the required recovery
rate is best expressed as volume treated per unit time.
For all treatment methods, deployment speed becomes
an important consideration for rapidly spreading oil slicks.
For spills on the open sea, effective treatment could
only be undertaken during daylight hours. For such cases, it
is arbitrarily assumed that at least eight hours of daylight
would be available for countermeasure activities in the vast
majority of cases.
For some postulated spill cases, onshore currents and
winds may become controlling.
It follows from the above discussion that different
quantitative recovery rates are required for each
combination of parameters. For purposes of this study, and
on the basis of the above reasoning, criteria were selected
for various combinations of parameters. These are shown in
Table 3.
These detailed criteria apply to systems which do not
utilize containment devices to prevent spreading movement
of the offending material.
For purposes of comparing various systems, the
following indices were utilized in the total effectiveness:
Rate of Removal Index
System exceeds criteria +2
System meets criteria +1
System fails to meet criteria by 1 order
of magnitude 0
System fails to meet criteria by 2 or
more orders of magnitude
The purpose of the (-1) rating is to assist in identifying
systems which may score well on other items but which,
because of inability to effect cleanup within the required
time span, could not be considered as practical systems.
Effect of Method on Pollution and Hazard
Generally, mechanical methods of spill treatment do
not cause adverse effects. An exception to this would be
mechanical systems which involve containment by booms or
corrals when employed on spills of JP-5. Prevention of
spreading of this flammable material, by gathering it in such
containment, might be undesirable because of the
associated fire hazard. Fire hazards may be minimized by
the application of dispersant.
Chemical methods must be carefully considered
because of the possibility that the chemical may be
hazardous to personnel. Certain types of sorbents may
create visibility hazards or ingestion hazards to personnel
from dusty conditions. The possibility of dispersed or sunk
materials reappearing at a later time must also be
considered.
The indices applied were as follows:
Effect Index
Reduces Pollution or Hazard +1
No Effect on Pollution or Hazard 0.5
Increases Pollution or Hazard , 0
Applicability to Areas Having Limited Access
Many cases of oil spillage may result from the
grounding of a vessel on a reef of protuberance. In these
cases, rescue and recovery operations as well as oil spillage
abatement procedures may be impaired. Shallow water
areas may also influence the operation of certain
mechanical devices. In the open sea environment, this effect
will not be pronounced as when near reef and shoaling
areas. The Maritime Casualty Record reflects that many
casualties are due to groundings. This was the case with the
GENERAL COLOCOTRONIS, the TORREY CANYON,
the OCEAN EAGLE, and the Tanker R. C. STONER. The
R.C. STONER grounded near the harbor entrance to Wake
Island, September 6,1967.
Consideration of this aspect, in the effectiveness
analysis, consists of evaluating each component of all
hypothetical and actual systems in terms:
• Access requirements in terms of water surface area
: and depth of planes perpendicular to water surface
needed for effective mobility.
• Maneuverability of system in terms of turning radius
and reversibility. Stability if floating or fixed objects
are struck during movement.
Each system was individually evaluated for the
parametric situations involving the characteristics
mentioned above. Indices were assigned for each system as
follows:
-------
EQUIPMENT AND METHODS 409
Table 3. Minimum Speed of Application Criterion for Governing Parameters.
Parameter
Location of Spill
Readily accessible open sea
areas when environmental
conditions are moderately
severe; (assume wind 20 mph
towards shore and spill 3
mi. offshore).
Readily accessible open sea
areas when environmental
conditions are moderately
severe; (assume wind 20 mph
towards shore and spill
12 mi. offshore).
Petroleum
Product
JP-5 and
Distillate
Fuel
Navy
Special
Bunker C
JP-5 and
Distillate
Fuel
Navy
Bunker C
Spill Size
Gallons
2,700
270,000
6,750,000
2,700
270,000
6,750,000
2,700
270,000
6,750,000
2,700
270,000
6,750,000
2,700
270,000
6,750,000
2,700
270,000
6,750,000
Minimum Oil
Treatment Rate
5,860 Ft2/Min
124,000 Ft2/Min
1,882,000 Ft2/Min
3,400 Ft2/Min
75,800 Ft2/Min
842,000 Ft2/Min
15 Gal/Min
1,540 Gal/Min
40,000 Gal/Min
3,560 Ft2/Min
82,300 Ft2/Min
1,010,000 Ft2/Min
2,150 Ft2/Min
47,500 Ft2/Min
280,000 Ft2/Min
4 Gal/Min
380 Gal/Min
9,650 Gal/Min
Basis
Recovery or dispersing before
oil reaches shore. One hour
for deployment (equipment on
the scene) and slick movement
at 4% of wind velocity.
Recovery or dispersing before
oil reaches shore. Four hours
for deployment (equipment on
the scene) and slick movement
at 4% of wind velocity assumed.
Applicability to Limited Access Areas
Exceeds Needs
Meets Needs
Does Not Meet Needs
Index
+1.0
+0.5
0
Sensitivity to Natural Phenomena or Floating Debris
Many mechanical systems are suceptible to stalling
from pluggage or blockage by floating debris. Design
features such as screens, strainers, and baffles may enable a
system to effectively handle such floating debris.
Systems employing rotating drums or endless belts of
sorptive material are vulnerable to damage and stalling if
rigid debris of irregular shape is picked up at the water
surface.
The sensitivity of a system to water, wave and wind
conditions is a significant performance factor. While it is
unlikely that spillage cleanup would be of priority concern
during severe storm conditions, effective systems must be
usable during conditions more severe than"calm." It seems
appropriate for purposes of this report to select conditions
which would prevail during the vast majority of the time -
applicable for as much as 90% of the time.
A study of worldwide weather established that the
significant wave height for 90% probability varies from 1.0
to 13.0 ft. For the purpose of this study the significant
wave height, worldwide, during spill countermeasure
operations was taken as an average of these samplings which
is 5.0 ft. By similar reasoning, the significant wind speed
was taken as 20 mph.
The indices applied to this aspect of countermeasure
effectiveness are as follows:
Effect Index
Not affected by 5.0 ft. waves, 20 mph winds, or
debris +2
Slightly affected by 5.0 ft waves, 20 mph
winds, or debris 1.0
Rendered inoperable by 5.0 ft waves, 20 mph
winds, or debris 0
Toxicity to Marine Life
Most chemicals dispersants are toxic to marine life.
Toxicity thresholds range from approximately 5 ppm to
10,000 ppm for presently used commercial materials.(5)
The actual effect of using a specific dispersant in a given
situation is dependent on the marine life present, the
diffusion characteristics at the spill locale, the effectiveness
of tidal flushing, the application rate, and the physical
characteristics of the spill material. Standards regulating the
use of dispersants range- from "unlimited" to "none
permitted." FWQA rules employed during the Santa
Barbara incident permitted chemical dispersants to be used
at ^ 1 mile off shore at concentrations equivalent to 5 ppm
in the top three feet of water.
The amount of chemicals required for emulsification
are generally two to three times the manufacturer's
recommendations - mostly due to the variance between
field application and laboratory testing. A typical chemical
dispersant must be used in the ratio 1:5 for effective use. It
-------
410 PHYSICAL REMOVAI
was concluded that chemical dispersants cannot be
effectively used within 1 mile of shore without exceeding
most toxicity limits. In deep water, dispersants could be
used more freely without known or measured adverse
effects on marine life.
The applicability of chemical methods will depend on
the circumstances of the specific spill situation and is
exemplified as follows:
Toxicity Index
Systems allowing no toxic residuals +2
Systems or spill situations allowing residuals
but not in excess of 5 ppm in top 3 ft
(when 1 mile or less from shore) or residuals
> ppm in top 3 ft but greater than 1 mile
from shore +1
Systems or spill situations allowing residuals >
5 ppm in top 3 ft (< 1 mile from shore) or
affecting benthic organisms adversely 0
Availability
An effective system for removal of oil pollutants from
the surface of open waters must be available for use when
needed. Many of the systems to be studied have been
extensively used and corresponding historical data are
available. Other systems have not been used enough to
provide a sound basis for judging these aspects. In the latter
instances, the systems were analyzed on the basis of the
experience with components involved, or similar
components, to derive estimates of availability probability.
Availability Index
Systems available ^ 95% of the time +2
Systems available 50-95% of the time +1
Systems available < 50% of the time 0
Sensitivity to Temperature
Systems for use in open sea conditions should be
effective over the range of temperatures encountered in
diverse geographic locations. Systems employing sorbents
or suction devices may be expected to be adversely affected
on thicker oils such as Navy Special and Bunker C at low
temperatures. The action of chemical dispersants is also
slowed by low temperatures. The mean sea surface
temperature in most areas of potential spillage is between
40°F and 80°F. It is appropriate that the systems should be
expected to function in temperatures down to at least
40°F. The indices applied for this criterion were derived
from the above reasoning and are:
Sensitivity to Temperature
Index
•These systems have 12 or more negative points (fails to meet rate
of removal requirements by 2 orders of magnitude) indicating ser -
ious inability of available equipment or methods to meet rate of
removal requirements. They were judged impractical to consider
at the present time.
Not affected by temperatures of 40-50°F +1
Slightly affected by temperatures of
40-50°F 0.5
Rendered inoperable by temperatures of
40-50°F 0
EFFECTIVENESS EVALUATION
The performance criteria and parameters which define
the range of spill situations have been combined to form a
matrix, Figure 1, to enable a comparative effectiveness
analysis of potential systems. A separate worksheet is used
for each postulated system; the sum of the index points for
that system then is a comparative measure of the ability of
that system to meet all of the criteria.
These systems are synthesized using state-of-the-art
equipment, and are evaluated on known present capability.
The comparisons of all systems indicate that thirteen
systems are superior (over 90 points). Of these, one
(biological degradation) was judged impractical because of
inability to meet requirements for rate of removal by
several orders of magnitude. The potential systems in
descending order of effectiveness are:
1. Chemical dispersants applied directly to the spill
(229)
2. Chemical dispersants plus containment (151)
3. Advancing gravity skimmer or weir (133)
4. Gellants/conveyor(self-propelled)(l32)
5. Gellants/conveyor plus containment (124)
6. Chemical burning agents applied directly to the
spfll(120)
*7. Enhanced degradation (addition of bacteria,
enzymes, etc.) (120)
8. Chemical burning agents plus containment (114)
9. Advancing gravity skimmer or weir plus
containment (109)
10. Sorbents/conveyor (self-propelled) (107)
11. Endless belt on water surface (portable) (106)
12. Sorbents/suction device plus containment (93)
13. Sorbents/conveyor plus containment (91)
14. Endless belt on water surface plus containment
(87)
* 15. Suction devices (portable) (87)
16. Sorbents/portable suction devices (83)
17. Sinking agents applied directly to slick (82)
18. Sinking agents plus containment (76)
*19. Rotating drums (self-propelled) (66)
*20. Rotating drums plus containment (66)
*21. Suction devices (portable) plus containment (63)
-------
EQUIPMENT AND METHODS 411
Containment generally does not improve the
effectiveness of these systems. This is because presently
available booms are not reliable or effective for open water
use. Dependence on a boom tends to make the system less
effective, i.e., oil escapes and equipment to treat oil outside
the boom is not available or planned for. The principal
deficiency of most- mechanical systems is inability to
function effectively in 5-foot waves and 20 mph winds.
It should also be recognized that in some cases the
criteria can vary with the parameters, or parameters and
criteria can be dependent on each other. An example is that
much more relative speed is required for a large spill close
to shore than for a small spill under similar conditions.
The parameters can also have different meanings
depending on the type of system. For a chemical system,
wave action aids in dispersing, while in a mechanical system
the wave action is a hindrance.
Other notes of this type, developed during the
effectiveness compilation, are given in the following
paragraphs.
Completeness of Removal
Chemical Systems - Implies that the oil is essentially
completely dispersed from the water surface and does not
reappear at a later time. This means that where water-in-oil
emulsions may form, as with Bunker C, or wave agitation is
insufficient, chemicals do not necessarily do a complete
job, as they may reappear.
Chemomechanical and Mechanical Systems - Implies
that the system removes the oil from the water surface
before it spreads or drifts out of range. Therefore, these
systems must operate more rapidly on spills of lighter
products. Also, the system must be capable of removing the
oil accumulated around obstructions or booms. This is not
the same as operating in limited access areas. For example,
rotating drums have little or no ability to draw heavy or
very light oils from the surrounding area and, therefore, will
not do an essentially complete job. More importantly, the
system must be capable of operating under the environment
conditions. Rotating drums and suction devices, for
example, will be severely hampered by wave action in open
sea conditions and the completeness of removal would be
expected to be very low.
Rate of Removal
Hazard and Pollution
Includes water surface pollution to waterfowl, facilities
and private boats (i.e., damage to recreation such as
swimming), fire danger, air pollution, navigational danger
and possible equipment damage from dusty conditions.
If a chemical dispersant reappears some time after
treatment the pollution can be great.
Sinking agents which release the oil at a later time are
similarly ineffective.
System Use in Limited Access
Ability to maneuver, chase windrows of oil and work
close to a ship. Also ability to pick up accumulated oil
behind a containment boom and operability in shallow
water for mechanical systems.
Sensitivity to Environmental Factors
Is the system itself sensitive to waves, etc., or does its
capability for retrieval decrease? For this evaluation, it was
considered that systems using containment booms available
today would be penalized because the booms themselves
would be subject to frequent overtoppings in 5-foot waves
or could be expected to come apart or tip over. This has
been the case to date with virtually every boom which has
been subjected to open sea conditions. Model tests by
Hydronautics Inc.(6) provide further evidence to support
the ineffectiveness of booms in open sea conditions. The
tests indicated that in sea state 5, which encompasses an
average wave height of 5 to 7.9 feet, conventional booms
would be overtopped frequently.
Toxicity
Applies only to chemicals. Excludes water fowl. The
conclusions drawn in the report, the TORREY
CANYON(7) and othersC8*9), that the offshore spraying of
detergents in deep water has no significant toxic or other
deleterious effect on offshore or inshore fishing were
applied to spills up to 270,000 gallons. However, for the
6,750,000 gallon spill, large amounts of dispersants would
be required, much of which would likely be close to shore.
For this case, the chances of exceeding 5 ppm near shore
would be great.
Availability
Any self-propelled system must be penalized in this
respect because the propulsion unit is bound to break down
or require periodic maintenance. Portable gear is superior
because it can use available vessels.
Speed often is an essential factor in completeness, i.e.,
the slick will spread too thin if it can't be recovered in time.
A system which fails to function because the film thickness
is too thin (as for burning where the film must be 0.03
inches thick or more) or which could not remove a slick
before it reached the shore (as for enhanced
biodegradation) would be severely penalized.
COST ANALYSIS
The life cycle costs of the twelve systems which scored
most effectively over the full range of parameters were
derived for the purpose of generating comparative cost
effectiveness indices.
-------
412 PHYSICAL REMOVAL . . .
SYSTEM:
Size
Parameters
Products
Criteria
Location
1 3 Miles
From Shore
I 2700 gal A JP-5
II 270,000 B Distillate
gal C Navy Special 2 12 Miles
III 6,750,000 D Bunker c From Shore
gal
1,1
FA Tl
L_2
P
l_2
P
L_2
P
L l_2
FA P
1.2
B P
L.2
P
l_2
D P
L L2
FA P
l_2
B P
L.2
c P
l_2
D P
LD L2
1
1
TOTAL
Figure 1: Effectiveness Analysis Worksheet.
-------
EQUIPMENT AND METHODS 413
Systems that had severe limitations in accomplishing
the oil removal or dispersal were not evaluated. Thus
biological degrading was not evaluated because a spill would
reach shore before any appreciable removal could be
effected.
Several systems have common cost data, such as hourly
labor charges. The hourly charge rates were derived from
either commerical rental rates or the cost of new equipment
depreciated over its expected life. Some equipment charges
such as booms were prorated per spill rather than on an
hourly rate, based on procurement costs depreciated over
the expected life. Maintenance costs were calculated on
accepted chemical industry rates for equipment in
moderate to severe corrosive environment (10% of
acquisition cost/year for mechanical equipment, 5% of
acquisition cost/year for booms).
IDENTIFICATION OF MOST COST
EFFECTIVE SYSTEMS
The cost analysis showed that the cost per gallon to
treat oil varies with the spill size and frequency. The cases
and parameters used are believed to represent the most
probable situations where oil spills of 2,700, 270,000 and
6,750,000 gallon sizes would require clean-up activity to
prevent oil contamination of resources. Cost data were
combined with the effectiveness indices by dividing the
cost/gallon of oil treated for each spill size and system by
the effectiveness index for each spill size and system. These
are shown in Tables 4, 5, 6 and 7. The system having the
lowest cost/effectiveness ratio is the most favorable. For
the small spills, the cost effectiveness is frequency
dependent and the choice of system then depends on the
number of spills of the small size which require treatment.
There are several practical matters to consider in the
selection of these systems. One of these is that presently
available booms have not been shown to be effective in
open sea conditions. Parting of the boom, frequent
overtopping in 5 foot waves, capsizing and oil carryunder in
currents or towing conditions exceeding 1 to 1-1/2 knots
are the principal deficiences.
Thus, a system using a containment boom cannot be
considered practically effective if reliance is placed on the
boom. Nevertheless it was assumed that a boom designed
for open seas could function for a limited time, though
inefficiently, to slow the spread of oil or gather and thicken
it for skimming or burning operations. Another
consideration is that burning agents could only be evaluated
for contained Navy Special or Bunker C and uncontained
Bunker C. This is because the other products, JP-5,
Distillate Fuel and uncontained Navy Special spread or
disperse and evaporate so rapidly that they would likely be
too thin for burning agents by the time equipment arrived.
(A 270,000 gallon spill of JP-5 or Distillate Fuel spreads to
less than the critical thickness for burning agents in about
two hours; for a 2,700 gallon spill it is a little over 10
minutes.) A third consideration is that if burning agents are
applied to oil that is surrounding or escaping from a vessle,
it will pose a serious threat to the vessel itself. Smoke
pollution near population centers is also an objectionable
aspect of burning.
Thus the decision to use burning agents is dependent
on location of the spill, type of oil and safety of the ship or
other valuable property. For these reasons, burning does
not represent a practical universal system even though its
cost effectiveness for certain oils is favorable.
Based on the effectiveness analysis, the most cost
effective system for removing or dispersing oil from open
waters are:
(1) Chemical burning agents applied to Bunker C prior
to emulsification or to Navy Special when the slick is thick
enough for burning. This method would be restricted to
areas away from the ship and other valuable property and
to areas where the smoke would not be considered a
pollution problem. As pointed out previously, this system is
not a practical universal system because of the restrictions
on oil type, thickness, emulsification, and location. This
system would be improved if seaworthy fireproof booms
were available to contain oil in thick layers for burning.
(2) Chemical dispersants applied directly to the slick
where the spill is one mile or more from shore. This system
appears to be the optimum choice for a universal system at
the present time. The effectiveness of this system would be
improved if seaworthy booms were available to prevent
spread of oil.
(3) Advancing skimmers or weirs for small and
intermediate spills, 2,700 to 270,000 gallons. Such a system
was used to collect up to 25 barrels/day (about 1,000
gals/day) during the Santa Barbara Channel incident.
Large offshore workboats or similar craft could be
equipped with detachable skimmer booms on each side
with associated pumps to collect up to 50 barrels/day each.
For major spills in the 6,750,000 gallon category, the
recovery rate is insufficient unless large numbers of vessels
are used; e.g., to clean up 6,750,000 gallons in 5 days
would require about 600 vessels recovering at 2,000
gals/day.
Considering the restraints listed previously, it is
concluded that the most practical universal system for
treating oil spills on open water is chemical dispersants
applied directly to the slick. Where feasible, a containment
boom designed for open seas application should be
deployed. Even though it may eventually fail or be
ineffective, it will slow the spread of oil for a period of
time. The oil which escapes may still be treated by
dispersants. Where regulations prohibit the use of
dispersants, burning (where feasible), or mechanical
removal by skimmer devices should be employed.
REFERENCES
1. P.C. Walkup, et al. "Study of Equipment and
Methods for Removing Oil from Harbor Waters," Report
No. CR.70.001 by BatteUe-Northwest for the U.S. Navy.
August 1969.
2. "A Report on Pollution of the Nation's Water by Oil
and Other Hazardous Substance," by the Secretary of the
-------
414 PHYSICAL REMOVAL
Interior and the Secretary of Transportation, p. 7, February
1968.
3. S.A. Berridge, R.A. Dean, R.G. Fallows and A. Fish.
"The Properties of Persistent Oils at Sea," /. Inst. Petrol.,
Vol. 54, No. 539. November 1968.
4. P.C. Blokker. "Spreading and Evaporation of
Petroleum Products on Water," Paper presented to the
Fourth International Harbor Conference, Antwerp. June
22-27,1964.
5. A. Oda. "A Report on the Laboratory Evaluation of
Five Chemical Additives Used for the Removal of Oil Slicks
on Water," Paper No. 2019, Ontario Water Resources
Commission, August 1968.
6.W.T. Lindemath, et al. "Analysis of Model Tests to
determine Forces and Motions of an Oil Retention Boom,"
technical note 948-1, a Report for the U.S. Coast Guard by
Hydronautics, Inc., January 1970.
7. The TORREY CANYON, Report of the Committee
of Scientists on the Scientific and Technological Aspects of
the TORREY CANYON Disaster, London: H.M.S.O., 1967.
8. A.C. Simpson. 'The TORREY CANYON Disaster
and Fisheries," Ministry of Agriculture, Fisheries and Food,
Fisheries Laboratory, Burnham on Crouch, Essex, February
1968.
9. UP. Holdworth. "Control of Accidental Oil Spillage
at Sea," Proceedings of the Institute of the Institute of
Petroleum Summer Meeting, Brighton, 1968.
-------
THE RECOVERY OF OIL FROM WATER
WITH MAGNETIC LIQUIDS
R. Kaiser and G. Miskolczy
Systems Division, A VCO Corporation
and
R.A. Curtis C.K. Colton
Purdue University Massachusetts Institute of Technology
ABSTRACT
A novel method of oil-water separation has been
developed which utilizes magnetism to separate the two.
phases. In this method, a ferro-fluid miscible with one of
the phases, usually the oU phase, is added to the mixture. A
femfluid is a stable magnetically responsive colloidal
dispersion of superparamagnetic particles. Adding a ferro-
fluid to a miscible liquid renders the mixture magnetically
responsive. Thus, when an oU-soluble, water-insoluble ferro-
fluid is added to an oil-water mixture, magnetic properties
are conferred to the oU phase alone. When the mixture is
passed through a suitable device in which a magnetic field is
generated, a selective magnetic body force is exerted on the
oU which is retained within the device while the water
passes through.
This method has been applied to the problems of
removing oil from the surface of the ocean and to the
separation of oil in water emulsions. In this paper, the
principles of removing oU from water by magnetic means
are discussed. Based on these principles, the different types
of equipment required to separate an oil-water emulsion
and to remove an oil spill from the surface of the ocean are
considered. Preliminary results and economic projections
are then presented.
INTRODUCTION
Magnetic techniques are commonly used to separate
solid materials, such as iron ore, from a solid mixture or a
liquid phase. However, magnetic forces have not been
previously applied to the separation of mixtures of two
immiscible liquids because most common liquids exhibit a
weak and insignificant magnetic response. In this paper,
new methods for separation of oil-water mixtures are
described. These techniques involve 1) conferring a signifi-
cant magnetic response to one phase of the mixture and 2)
exerting a selective body force on that phase within an
appropriately designed separation device.
As previously reported (1), the proper addition of
colloidal particles of a ferromagnetic solid to a liquid results
in a mixture that has unique physical characteristics. These
materials, known as ferrofluids, combine a strong magnetic
response with regular liquid state properties that are
retained even in a magnetic field. Addition of a ferrofluid
to a miscible liquid renders the entire phase magnetically
responsive. Significant magnetic properties can be given to a
specific component of a mixture of immiscible liquids by
adding a ferrofluid which is miscible with that phase alone.
In particular, addition of an oil-soluble, water-insoluble
ferrofluid to an oil-water mixture selectively confers mag-
netic properties to the oil phase. Oil-water separation is
then accomplished by passing the treated mixture through a
magnetic field generated within a suitable device. A
selective magnetic body force is exerted on the oil which is
thus retained within the device while water passes through
unhindered. This results in very rapid and selective separa-
tion of the liquid phases, even when one of the phases is
present as a thin surface film or as a fine, stable emulsion.
In the following sections of this paper, the requirements
imposed upon ferrofluids for oil-water separation and the
parameters influencing magnetic liquid-liquid separation are
first discussed. Two applications of magnetic liquid separa-
tion are then described. These are the harvesting of a thin
oil slick from the surface of the ocean and the essentially
complete removal of emulsified oil from tanker ballast
water.
Description of Ferrofluids
Ferrofluids are stable colloidal dispersions of single
domain ferromagnetic particles that do not settle under
gravity or in the presence of a strong magnetic field. The
415
-------
416 PHYSICAL REMOVAL ...
magnetic response of a ferrofluid is a result of the coupling
of individual magnetic particles with a substantial volume
of the surrounding carrier liquids. Coupling is facilitated by
the presence of a stabilizing agent which can adsorb on the
surface of the particle and also be solvated by the
surrounding carrier liquid. Consequently, in the presence of
an applied magnetic field, the force experienced by each
particle in the direction of the magnetic gradient is also
transmitted to the bulk liquid phase, even at high dilution
ratios. The stabilizing agent serves two other functions:
a) By proper choice of stabilizing agent, magnetic
properties can be selectively conferred to a wide range of
liquids which include water, hydrocarbons, and fluorocar-
bons;
b) The solvated "sheath" is also responsible for the
stability of the suspension. The particles in suspension do
not flocculate in a magnetic field because their size is small
enough (about 100A) for thermal agitation (Brownian
motion) to exert a significant dispersive influence. The
solvated sheath provides short range repulsion between
particles. If this were not accomplished, interparticle
attractive forces of molecular and magnetic origin would
rapidly lead to particle agglomeration and gross phase
separation.
The particular ferrofluids that can be used for oil
recovery application require certain physical and chemical
attributes which are listed in TABLE I. Ferrofluids suitable
for oil recovery applications, for example, consist of a
TABLE 1
A. Miscible with a wide range of petroleum products,
ranging from light oils to heavy residual fuel oils.
B. Less dense than sea water.
C. Insoluble in water.
D. Do not spread on water.
E. High magnetic susceptibility.
F. Low viscosity for ease of application.
G. Non-toxic and safe to handle.
H. High flash point.
I. Must not be a serious pollutant.
colloidal suspension of magnetic iron oxide (either Fe304
or oFejOa) in a light, saturated hydrocarbon oil. They are
thus soluble in oil and insoluble in water. These oil-control
ferrofluids are formulated in such a way that they have
carefully controlled spreading characteristics. In most in-
stances, it is desirable for the ferrofluid to have a negative
spreading coefficient against water. This results in minimal
surface activity and eliminates undesirable side effects such
as uncontrolled oil emulsification.
The magnetic properties of ferrofluids can best be
described by considering the particles in a ferrofluid to
behave as an assembly of non-interacting magnets (2). In
the absence of a magnetic field, they are randomly oriented
and the ferrofluid has no net moment. In a magnetic field,
the magnetization of a ferrofluid, M, increases with
increasing field until a saturation value is reached. Under
these conditions, the particle moments are aligned in the
direction of the applied field, and the saturation magnetiza-
tion of the ferrofluid, Ms, is given by
Ms = eM* (1)
where 6 is the volumetric concentration of magnetic colloid
and M* is the effective domain magnetization of the
colloidal particles. For oil spill applications, magnetite
concentration, and hence ferrofluid magnetization, is lim-
ited by the operational requirements that the ferrofluid
should not sink in sea water. Ferrofluid density, Pp, is
expressed as:
Pp = ep + pL (1 -e) (2)
where
p = density of the magnetic particles, g/cm^
PL = density of the carried liquid, g/cm2
For a limiting value of Pp = 1.03 g/cm3 (density of sea
water), e = 0.07 for a kerosene-based (p£ = 0.80 g/cm3)
magnetite (p = 4.Sglcm3) ferrofluid. Such a ferrofluid has
a saturation magnetization from 200 to 300 gauss.
Typically the viscosity of ferrofluids is low, i.e., 10 cp at
30°C for a 300 gauss ferrofluid. There is, furthermore,
surprisingly little influence of shear rate and magnetic field
on the viscosity (3).
Use of Magnetic Body Forces
To Separate and Control Liquid Phases
When a ferrofluid is placed in a magnetic field, there
results an induced magnetization within the ferrofluids. If,
in addition, there is a gradient of the magnetic field, then
there is also a net force on the ferrofluid. The magnitude of
the force per unit volume of fluid is proportional to the
induced magnetization and to the applied field gradient:
IM= J_ MVH (3)
F 47T
Approxpiately designed magnetic field gradients may be
imposed on a magnetized oil-water mixture in a number of
ways. The mixture may be made to flow in the fringe field
region outside the gap of a magnet (Figure la), in the gap
of a magnet with appropriately shaped pole pieces (Figure
Ib), or in a chamber in which ferromagnetic objects are
placed to locally alter the field distribution (Figure Ic). By
appropriate device design, the force exerted on a ferrofluid-
oil mixture at local points within the device may be made
as high as 103 to 106 times that exerted by gravity. This
force accelerates the ferrofluid toward the zone of maxi-
mum field where it then behaves as though it is restrained
by a magnetic pressure, PM, which can be expressed as
(4,5):
-------
RECOVERY WITH MAGNETIC LIQUIDS 417
H MdH
~4JT
la) IN FRINGE FIELD OF MAGNET GAP
-GRADIENT FRINGE FIELD
For high fields in which M = Ms,
The pressures required to dislodge a 100 gauss ferrofluid
from the gap of typical hand magnet (H = 2000 oe), a
saturated iron-gapped electromagnet (H = 20,000 oe), and a
super-conducting magnet (H= 100,000 oe) are 0.23 psi, 2.3
psi, and 11.6 psi respectively. These numbers indicate that
it is possible to generate reasonable magnetic pressures, of
the order of 1 psi, with standard electromagnets and
relatively dilute ferrofluids.
Generalized Process Description
The magnetic oil-water separation process consists of the
following principal steps:
1) Rendering the oil phase magnetic by mixing it with
an oil-based ferrofluid, preferably before it comes into
contact with water.
2) Passing magnetized oil-water mixture in the vicinity
of a magnetic field source, which results in the capture of
the oil phase while allowing water to flow by unhindered.
3) Removing the magnetized oil from the magnetic
collection device.
4) Storing the recovered oil.
While the overall process is conceptually the same, the
equipment and procedure required for each operation will
vary with the nature of the specific separation problem.
This is exemplified by the two examples discussed in the
following sections, the harvesting of an oil slick and the
removal of emulsified oil from ballast water.
Magnetic Oil Spill Harvesting
Background
Oil spills continue to pose a constant threat to the
environment. In spite of the increasing public pressure to
develop improved oil slick control methods, none of the
existing systems developed to date are fully satisfactory.
Tables II and III list the specifications of what would
constitute an effective oil spill harvesting system (6): These
specifications are dictated by the following considerations:
1. An oil slick is essentially a discontinuous layer of ofl
floating on the surface of the sea. This film spreads
spontaneously and rapidly becomes a thin film, less than 1
mm thick, of extended surface area.
2. The composition of an oil slick is a dynamic variable.
At time of collection, the oil slick is often a very viscous
fraction of the initial spill, altered by exposure to the
environment. The oil will often contain significant amounts
of emulsified water ("chocolate mousse").
3. The size of an oil spill is variable. Some of the better
publicized incidents involved spills that contained many
thousands of barrels of oil.
FERROMAGNETIC MATERIAL
VOIDS
10 IN MAGNET GAP PARTIALLY Fl LLED WITH FERROMAGNETIC OBJECTS
Figure 1: Generation of Magnetic Field Gradients
4. Major oil spills, especially in off-shore waters, usually
occur under adverse environmental conditions.
5. It is not possible to predict the future occurrences of
a specific oil spill.
The principal drawback common to many harvesting
systems which attempt to contain or physically remove the
oil from the water surface is the lack of selective action on
the oil film itself. In such cases, any attempt to collect the
oil will also result in the collection of a much larger amount
of water, which then must be removed. The quantity of
water collected, which can exceed the amount of oil picked
by a few orders of magnitude, determines the collection
capacity of the harvesting system. The exceptions are
processes based on adsorption on oleophilic substrates or
percolation of oil through selective barriers (7) which have
the drawbacks of limited capacity. Severe materials han-
dling problems are associated with the distribution and
recovery of sorbents. The objection also applies to use, as
oil sorbent, of polystyrene foam beads coated with iron
which can be collected with a magnet (8).
Process Concept
A conceptual flow diagram of a generalized magnetic oil
spill harvesting system is presented in Figure 2. Magnetic
properties are first imparted to the floating oil by addition
of an oil-soluble, water-insoluble, oil-recovery ferrofluid.
The surface layer of water with the treated oil slick is then
channeled into the vicinity of the gap of a magnet where a
selective magnetic body force is applied to the oil, drawing
it from the water into the gap. The gap of the magnet also
acts as an accumulator from which the water-free oil can
-------
418 PHYSICAL REMOVAL ...
FlOW DIAGRAM FOR MAGNETIC OIL SPILL REMOVAL SYS1EM
Figure 2: Flow Diagram for Magnetic Oil Spil Removal System
then be withdrawn with standard pumps and transferred to
suitable storage containers.
Experimental Demonstration
A series of simulated oil spill recovery tests were carried
out to determine the effects of various factors on the
efficiency of separation. These factors included oil type,
water characteristics (e.g., fresh water versus sea water),
mixing of oil and ferrofluid, oil magnetization, magnetic
field configuration, and flow conditions.
The largest of these recovery tests were carried out in a
200 gallon, 57 inch diameter test tank, filled with tap
water. The magnetic field source consisted of a water-
cooled cofl whose overall dimensions were: o.d. = 6 inches,
i.d. = 1 inch, length = 3 inches. A maximum field of 2000
oe was generated in the pp. The cofl was placed horizon-
tally in the water with its axis at the water line. A suction
tube was mounted in the center of the cofl with its inlet
just above the water level. This tube was connected to a
vacuum pump to remove ofl which was magnetically drawn
into the cofl.
A demonstrative test is pictured in Figure 3. Approxi-
mately 500 ml of No. 6 fuel ofl (density = 0.965 dcm*,
viscosity = 2000 cp at 30°O was mixed with the 100 ml of
oil-based ferrofluid (Avco No. 1111) with a saturation
magnetization of 100 gauss. The resulting mixture, which
had a saturation magnetization of about 16 gauss, was
poured on the water surface in the test tank. As shown in
Figure 3a, it formed an irregular slick about 30 mils thick,
VA. ft wide and 3 ft long. Initially the closest edge of this
slick was about 1 ft from the throat of the cofl (which was
near the edge of the tank). At this distance, the cofl had
only a slight effect on the slick. However, once the edge
drifted to within about 5 in. of the cofl, the ofl was quickly
drawn into it (Figure 3b). Within about 20 seconds after
that the entire slick collected in the vicinity of the cofl.
Therafter the vacuum pump was turned on and the ofl was
drawn through the suction tube into a receptacle (Figure
3c). Essentially all of the floating magnetized ofl was
collected (some adhered to the side of the tank). A small
amount of ofl was left as a transparent film on the water
about 10 microns thick.
In addition to the quasi-static tests, such as the one
described above, model tests were performed under condi-
tions more representative of the environment of an opera-
tional system. The disruptive forces generated by open sea
conditions could not be obtained in this tank. Therefore,
the test conditions were chosen such that both the
disruptive forces caused by the motion of the water and the
magnetic capture forces acting on the oil were smaller in
magnitude than would be operative in a full scale system.
In these tests, a 27 inch diameter center ring was placed
in the tank, creating a 15 inch wide annular channel. Water
was pumped around the channel at a surface velocity of
about 5 cm/sec (0.1 knot). In a typical test, Number 6 ofl
was poured onto the surface of the water and allowed to
form a discontinuous, elongated slick less than 0.5 mm
thick. Ferrofluid 1111 was sprayed into the ofl and allowed
to mix, forming an oil-ferrofluid mixture with an average
saturation magnetization of about 20 gauss. When the
electromagnet was activated, the magnetic ofl was collected
in the gap of the magnet and then pumped into a remote
container. Ultimately, about 97 per cent of the oil floating
in the channel was removed with about an equal volume of
water. However, of the ofl recovered the first 70 per cent
was collected without the entrainment of free water.
These tests demonstrated the feasibility of separating a
thin slick of ofl from water with magnetic forces. Magnet-
ized ofl is drawn into the gap of even the relatively weak
magnet used. This ofl accummulates in the gap, to the
exclusion of air and water. Once the gap is filled with ofl,
an aspirator intake placed in the magnet gap will draw only
ofl. Significantly unproved results are expected with full
scale systems which would use more powerful magnets.
Development of an Operational System
An integrated magnetic ofl spill harvesting system is
basically a sea-going magnet with auxiliary equipment
required to add ferrofluid to the ofl slick, and with transfer
and storage facilities for the collected ofl. The possible ways
of utilizing a magnetic ofl spill recovery process are limited
only by the operational requirements (Tables II and III)
and the laws of magnetism and fluid mechanics. Any source
of magnetic field produces a field distribution, the magni-
tude of which decreases rapidly with distance from the
source. As a consequence, the magnetic forces produced in
a magnetizable substance (the treated ofl), although large in
the vicinity of the field source, decay rapidly with distance
from the source. For significant forces to be brought into
play, the ofl must be close to the magnet. Given the large
area of an ofl slick, this is best accomplished by moving the
magnet through the slick.
According to Equation (5), there is a restraining pres-
sure, PM, exerted on a magnetic fluid (ferrofluid and ofl) in
the gap of a magnet, approximately equal to the product
4° £, where Mo is the fluid magnetization and Hg is the
field in the gap. For efficient operation of the collector,
this magnetic pressure must exceed the sum of the pressures
-------
RECOVERY WITH MAGNETIC LIQUIDS 419
Figure 3: Photographs of Experimental Magnetic Oil Spill Collection
System.
Figure 3a: In absence of a magnetic field, a thin slick of No. 6 Fuel
oil previously treated by addition of an oil base ferrofluid. floats
freely on water in a 2 meter pool. The oil contains 19t magnetite by
volume.
Figure 3b: The electromagnet is turned on. The oil is diawn into the
gap of the magnet by the fringe field. The oil is concentrated in the
annular gap where the field is 2000 oe.
Figure 3c: Oil is separated from the gap into a receiving bottle
outside the pool. Since the entrance of the suction pipe is placed in
the gap above the water line there is no carry-off water as would
occur in standard skimming systems.
which tend to dislodge the oil from the gap. These
pressures are 1) the stagnation pressure due to the relative
velocity, V, between the collector and the oil slick (VipK2,
P * 1 glcrn3); and 2) the hydrostatic head, pgh, of water
above the magnet gap, e.g., from waves impinging on the
collector, where h is the instantaneous peak difference in
water level between the magnet gap and the surrounding sea
surface. The conditions which must be met to prevent
magnetized oil from being dislodged from the gap due to
these pressures can be expressed as follows:
MoHg
4?r
+ pgh
(6)
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420 PHYSICAL REMOVAL .
TABLE 2
A. Rapid oil recovery rate
B. Complete removal of oil from the water surface
C. Minimum amounts of water entering each unit process
D. Minimum influence of water motion and waves on
collection efficiency
E. Minimum amount of auxiliary eqipment
F. Reject floating solids of a size which will interfere
with the efficiency of or damage the recovery system
G. High mobility and maneuverability
H. Compatibility with marine life
I. Reasonable first cost
J. Low operating expense
K. Minimum maintenance requirements
L. Maximum ease and speed of repairs
M. Readily available replacement parts
N. System independent of physical properties of oil.
TABLE 3
ENVIRONMENTAL
CONDITIONS
Wave Height
Wind Velocity
Current Velocity
OPERATIONAL
REQUIREMENTS
Slick Thickness
Oil Collection Rate
Water Content of
Collected Oil
Residual Oil in
Effluent Water
Types of Oil
Protected
Waters
2ft.
20mph
6 Knot
Open
Waters
5ft.
30mph
2 Knot
< 1.5 mm < 1.5 mm
3000gal/hr. 10,000 gal/hr.
<10mg/l
Light Diesel-
Heavy Asphalt
<10mg/l
Light Diesel-
Bunker C
iron. The magnetic pressure corresponding to these limits is
approximately 0.5 atm (7 psi). This is equal to the
stagnation pressure of a 20 knot current or the hydraulic
head of 15 ft of water. With the rapid development of
economical superconducting magnets, capable of generating
fields larger by one order of magnitude, a limiting magnetic
pressure of 5 atmospheres may be feasible in the future.
Under operational conditions, lower magnetic pressures
will be obtained, if only because the ferrofluid is diluted
with the oil to be removed. Since the ferrofluid is a
consumable additive, logistic and economic considerations
make it desirable to use the minimum amount of ferrofluid
necessary to achieve efficient harvesting especially for large
spills at sea. The implications of the above are:
1. The strongest possible magnet should be used as a
collector.
2. The amount of ferrofluid required to achieve com-
plete harvesting will depend on the operating environment.
• Many configurations for a magnetic collection system
are conceivable because a magnetic field can be oriented in
any desired direction and can also be deployed either at the
waterUne or underneath the surface. Two examples of inte-
grated magnetic harvesting systems are presented, the first,
more suitable for small spills in protected waters, the
second for large spills in the open sea. In addition to these
representative integrated designs, a magnetic oil collector
could be used as a sub-system of existing collection systems
in order to augment the oil collection capacity and improve
their efficiency.
TO COLLECTION PUMPS
WATER OUTLET
Figure 4: Cross-Section of Magnetic Oil Collector
It is useful to consider the limiting capabilities of a-
magnetic collection system in terms of equivalent velocity
and wave height. The maximum magnetization of an oil
slick will be that of undiluted ferrofluid whose density is
equal to that of sea water. As discussed in a previous
section, such a ferrofluid will have a magnetization as
high as 300 gauss. The maximum gap field economically
obtainable with current state-of-the-art designs is 20,000
oe, this limit being imposed by the magnetic saturation of
The first example (shown in Figure 4) is a collector
magnet floated on twin pontoons, and propelled through
the oil slick by an auxiliary vessel. The pontoons are
designed to keep the collection gap in close proximity to
the water surface. A permanent magnet is presented in the
sketch for purposes of simplicity. However, in practice, an
electromagnet would be used. Flexible suction pipes lead
from the collection pp to an oil pump, which can be
mounted on the magnet. Flexible discharge pipes lead
-------
RECOVERY WITH MAGNETIC LIQUIDS 421
either to a tank on board the propelling vessel or to an
auxiliary barge.
As the magnetic collector traverses a previously mag-
netized oil slick at a velocity, V, there will be a diversion of
the lower layers of water underneath the magnet while the
surface layer of oil and water approach the gap. The
magnetic oil is captured by the magnetic field and collects
on the pole faces. Any water which initially passes through
the gap is unaffected by the field and is discharged from the
bottom and sides of the collector. The oil collected at the
pole faces accumulates until it fills the gap; the water flow
subsequently by-passing the completely filled gap. The
magnetic pressure restrains the oil against kinetic head of
flowing liquid. Once the gap is filled, water-free oil is
continuously removed from the gap by applying suction
from the oil pump.
Under the action of waves and the bobbing motion of
the collector in the sea, the magnet gap will oscillate about
the water line. When the gap lies above the water line, oil is
Figure 5: Oil Spill Harvester (Cross-section)
dammed up against the lower part of the leading edge of
the collector with water flowing under the harvester. This
water flow tends to drag the dammed oil with it due to
viscous drag of the water on the oil. The oil is retained
against the drag forces by the fringe field of the magnet
which tends to draw this oil into the gap. Although this
magnetic force is lower than that experienced by the oil in
the gap, the dislodging force is also lower and the magnetic
forces resist the tendency for oil to pass underneath the
magnet.
When the magnet gap is below the surface, .the oil
delivered to the magnetic collector will tend to dam up
against the upper leading edge of the magnet. The leakage
field around the sides of the magnet will enhance the
viscous drag forces and the oil will be rapidly drawn into
the gap. This reduces the tendency for the oil to splash over
the top of the magnet. The most critical condition exists
when there is an instantaneous change in the level of the
water outside the collector and no change in the level of
water inside the magnet, as would occur with an impinging
wave. This results in dislodged pressure proportional to the
difference in hydrostatic head, h. This hydrastatic head
across the gap will be primarily a function of the ability of
the collector to follow wave induced variations at the ocean
Figure 6: Oil Spill Harvester (Plan View)
surface. If the frequency of the waves is less than the
natural bobbing frequency of the collector, then it will be
able to respond to these relatively slow variations of surface
height and will remain at the ocean surface. Waves with
amplitudes greater than 1 ft have frequencies of less than V4
sec (9). The bobbing frequency,/j, of the collector is given
here by the following equation:
fb =
-
27T
(7)
where g is the acceleration of gravity and dl is the effective
draft of the collector. If d1 < 3 ft then/j > VL sec.
By continuity, the volumetric flow rate of oil collected,
Qo, is related to the velocity of the magnet relative to the
oil by the following equation:
Qo = VtL (8)
where t is the thickness of the oil slick and L is the
collection length.
Substituting for V in expression (6) results in the following
expression:
Qo
MoHg 1
4?r 2
Lt
pgh
(9)
To meet the specifications for protected waters listed in
Table III (Qo = 3000 gals/hr., wave height = 2 ft), assuming
that Hg = 20000 oe, L = 6 ft, and that h = 1 ft, the
minimum oil slick magnetization required for capture is 30
gauss. An oil slick with a magnetization of 50 gauss would
-------
422 , PHYSICAL REMOVAL ...
be captured even if the collector were subjected to the full
height of the waves. At this collection rate, the harvester
would move through the slick at 3 knots.
The size of the magnet is principally determined by the
gap field, assumed to be 20,000 oe, and the volume of the
gap. The volume of the gap should be larger than the
volume of ofl collected in the period of time /j,/2 in order
to prevent water from entering into the suction pipes. For
Qo = 3000 gals/hr and fj, = 0.5 sec, this minimum gap
volume is SO in3. Since it was assumed that the magnet has
a collection length of 6 ft (72 in.) the magnet would have a
gap volume of 72 hi3 with only a one inch square gap. This
arrangement will require a magnet with an overall volume
of approximately 30 ft3 (2 ft high x 2.5 deep x 6 ft long).
It would weigh approximately 10000 Ibs, and require a
flotation equivalent to the displacement of 150 ft3 of
water.
A promising variation of this magnet configuration is a
"magnetic ofl broom" (TM) presently under development.
This is a smaller, lighter and thus more maneuverable device
capable of being handled by one man from a small boat. It
is designed to clean up oil spills which occur at docking
facilities due to the accidental spillage of small quantities of
oil. This device for example would be able to operate in
presently inaccessable areas such as underneath piers, or
around wooden or concrete pilings.
A promising prototype design for high rate collection in
open waters is a unique T-shaped vessel, as shown in Figures
5 and 6. This "spill harvester" has an oil counter gap in the
bottom of the hull in the broad leading edge of the vessel.
In this configuration, the magnetic collector is held in
continuous contact with the magnetic ofl which is forced to
go underneath the hull of the vessel. The previously
magnetized ofl, which has a nominal magnetization of 50
gauss is drawn into the collection gap, the region of highest
magnetic field. As in the floating collector of the previous
example, a conventional pumping system can withdraw the
ofl and send it along to a storage container in the ship's
hold.
The hydraulic head, which naturally occurs at the gap,
can flood the magnet gap and water can be drawn into the
pumping/storage system, if there are lapses in the ofl film,
or if the ofl is removed too rapidly from the gap. To offset
this, a small, sealed air chamber is located directly above
the gap which provides a slight over pressure (about 0.4 psi) •
at the upper ofl surface. This pressure, which is ordinarily
offset by the magnetic pressure developed in the ferrofluid-
oil mixture, wfll keep water from the ofl suction ports.
The magnetic collector of the proposed system is made
up of 10 electromagnet modules joined together. Each
magnet module has pole pieces shaped to provide a 20,000
oersted magnetic field across a 3 cm pp, and each contains
suction tubes which carry the oil from the gap to a
self-priming pump. The magnets are mounted in the
non-magnetized aluminum hull (nominally 9 inches below
the water surface) and extend the width of the 20-foot hull.
The power necessary to drive the magnet is 28.8 KW per
module or about 288 KW total. Power is provided by a 300
KW generator.
The basic system would contain four modules which
could be carried on deck of a mother ship, or disassembled
for air transport in a large cargo plane. The system could be
deployed at the ofl spill site either as a towed unit or a
self-propelled craft. The system provides for intermediate
storage of recovered ofl and has provisions for ofl transfer
to supporting vessels. It is an integrated system designed to
operate at up to 6 knots. This corresponds to a harvesting
rate of 16 acres per hour. Assuming an ofl thickness of 1
mm, this is equivalent to 12,500 gallons per hour.
The ferrofluid, which is added to the ofl slick, must float
on water. This ferrofluid is a relatively dilute suspension of
magnetite (7 vol%) in a light ofl. In order to minimize
storage and logistic problems associated with responding to
ofl spills, which may occur anywhere and at any time,
storage and shipment of a concentrated ferrofluid is
envisioned. This concentrate is a ferrofluid with the
minimum amount of diluent liquid needed to obtain
reasonable flow properties. It is also a much denser liquid.
This concentrated ferrofluid would contain four times as
much magnetite and would be twice as dense as the
operational fluid. It would be diluted, at the site of the spill
or the nearest port, with a locally available diluent, which
could be kerosene, No. 2 Fuel Ofl, or even ofl recovered
from the spill.
The best method of adding ferrofluid to the oil spill is at
the source, such as a well head or a grounded tanker. When
this is not feasible, the ferrofluid, then, is best dispensed
from a second boat proceeding the harvester. It could also
be dispensed from an aircraft or helicopter in case of a large
spill at sea, or by a portable spraying unit in case of a very
small spill.
In a typical case, the ferrofluid is added to the slick
metering it into a set of high speed water streams, similar to
the stream of a fire nozzle which would provide relatively
uniform coverage of the slick. These water jets enhance the
mixing of the ferrofluid with the ofl. Further mixing is
obtained by allowing a certain distance between the
spraying boat and the harvester. Typically, one minute is
considered to be sufficient time to obtain the degree of
mixing of the ofl and ferrofluid required for efficient
harvesting. The mixing time is a strong function of sea state
and viscosity of the ofl; the one minute criterion is based on
the time needed to provide good mixing in a low viscosity
ofl in a sea-state. With the high viscosity oils, the mixing
need not be as thorough since the consistency of the ofl has
been found to result in favorable side effect In this case,
the magnetic fractions of a slick drag the ferrofluid free
parts with them into the collector.
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RECOVERY WITH MAGNETIC LIQUIDS 423
The nominal quantity of feirofluid that is added is one
gallon of 300 gauss ferrofluid to five gallons of oil. This
corresponds to the addition of one gallon of concentrated
ferrofluid to 20 gallons of oil. Since the thickness of the
slick and sea state are not constant, the flow rate of
ferrofluid will be controlled by the efficiency of the
harvester under operating conditions, i.e., the detection of
significant quantities of oil downstream of the magnet.
Less ferrofluid will be required with lower collection
rates and in lower sea state. In some instances, where the oil
spill can be used as a diluent, as in the case of a low density
oil, it is possible to recycle the ferrofluid. A regular
ferrofluid would be used to begin the clean-up operation.
However, after the initial clean-up had begun, the recovered
oil (saturation magnetization of about 50 gauss) could be
mixed with ferrofluid concentrate to achieve the 200-300
gauss saturation magnetization of ferrofluid and be recycled
to recover the remainder of the slick.
The principal advantage offered by the magnetic oil spill
harvesting process described above is its ability to collect a
thin slick of oil at an acceptable rate with little entrainment
of water. The ability to exert a positive, selective body
force on the oil, at a finite distance away from the magnet,
makes essentially total removal of the oil feasible.
The potential of ecological damage is minimal with this
process since the additive is removed with oil. Any
ferrofluid left in the water does not constitute a serious
pollutant inasmuch as the carrier is volatile enough to
evaporate in time. Ferrofluids have been prepared with
biodegradable stabilizing agents. The magnetic particles are
the only true residue and will form traces of a harmless
inorganic addition to the silt on the ocean, lake or river
bottom.
Since ferrofluids are liquid, they can be easily handled
and dispensed, lending to mechanization of the operation.
Minimal on-site labor will be required. The recovered oil
can often be used as fuel or reprocessed in a refinery.
Furthermore, a relatively small amount of magnetic mate-
rial is required to obtain oil removal. It should be noted
that the cost of the raw materials for a ferrofluid are less
than 10«/lb. All these factors result in projected recovery
costs of between $0.25 and $1.00 per gallon of oil
recovered, depending on the particulars of the slick, for a
fully operational system. These costs are significantly lower
than current, less effective systems.
Magnetic Separation of Oil-Water Emulsions
Background
The water borne commercial fleets are powered almost
exclusively by ofl, and perhaps one vessel in five is also
engaged in transporting it. A major source of oil pollution
of the seas occurs as a result of the deballasting of vessels,
the cleaning of ofl tanks and the pumping of bilge water
which collects in the below decks areas of vessels and which
usually becomes mixed with these waste oils. According to
a recent survey (10), normal maritime traffic accounts for
about 50% of the direct oil losses in the world's waters.
This oil is usually discharged as a dilute emulsion of fine oil
droplets (less than 10/u diameter) in water. Many major
tanker operators are applying improved operational meth-
ods, such as the load on top procedure and installing
mechanical shipboard oil-water separators. Even with these
methods, however, if the oil is suspended as a stable
emulsion, it is not presently feasible to have a water
effluent that meets present international standards (less
than 100 mg oil/liter), much less some of the stringent
standards that are expected in the future (less than 10 mg
oil/liter). The principles of magnetic liquid separation used
to harvest a thin oil slick, are also applicable to the problem
of separating stable oil in water emulsions. As will be
discussed, essentially total removal of oil is obtained with
the addition of only small amounts of ferrofluid to the oil
phase, even at high volumetric flow rates of the emulsion
through a suitable magnetic separator.
Separation Principle
In this novel magnetic process for oil/water separation, a
ferrofluid miscible with one of the phases, usually the oil
phase, is added to. the mixture. Thus, when an oil
soluble/water insoluble ferrofluid is added to an oil/water
mixture, magnetic properties are conferred to the oil phase
alone. When the emulsion is passed through a bed of
magnetic material in which a magnetic field is generated, a
selective magnetic body force is exerted on the oil. The oil
is thus retained within the device while the water passes
through. This has proven to be a very effective way of
separating even very fine, non-coalescable oil in water
emulsions. It has been possible to obtain reductions in oil
concentration of three to four orders of magnitude in
residence times of the order of 10 seconds.
A typical feed would be an emulsion of crude oil in
water which contained 1% to 5% oil, present as stable
droplets with a volume mean particle diameter of 4 micron.
Even the addition of 0.1% magnetite colloid to the oil
results in its essentially total removal (less than 10 ppm oil)
from the water. A typical bed for these applications
consists of fine powders or screens of a ferromagnetic metal
such as iron, cobalt or 400 series stainless steel in the
presence of an externally applied field of 1000 to 5000 oe.
hi comparison, centrifuging this emulsion in a standard
2000 g laboratory centrifuge for 2 hours results in little
separation since the density of the oil is close to that of
water. In this instance, based on a residence time of 10
seconds, the magnetic separation can be considered as the
static equivalent of 1,000,000 g centrifuge. A small
hand-held demonstration unit is shown in Figure 7.
Experiments
The separation of suspended oil from water is being
studied in a laboratory magnetic oil-water separation
system which consists of a separation cell filled with
magnetic packing placed in an appropriate magnetic field
-------
424 PHYSICAL REMOVAL.
Figure 7: Demonstration of Magnetic Liquid Separation.
An 1% emulsion of magnetic crude oil (magnetization of 10
gauss) is shown in Tube 2. The emulsion is passed through a
small magnetic separator cell, placed in the gap of the hand
magnet. The clear effluent (< 10 ppm oil) is shown in Tube
1. Tube 3 contains distilled water for comparison.
source, and the necessary reservoirs, pumps, flowmeters,
gages and collection system, as shown in Figure 8.
The results of some typical tests being performed are
presented here. A stable non-coalesable emulsion of kero-
sene in water, stabilized by the addition of Tween 80 (Atlas
Chemical Co.), was prepared in a high speed blender. This
kerosene had a magnetization of 10 gauss. As shown in
Figure 9, all the droplets in suspension were smaller than 10
microns and had no tendency to coalesce, based on
sequential particle size measurements taken over a 25 hour
time span. The emulsion was pumped through a packed bed
of ferromagnetic powder, placed in the gap of an electro-
magnet, at different flow rates. The effluent water was
collected sequentially. The oil concentration of the consec-
utive samples was measured by gas chromatography, gener-
ating breakthrough curves typical of adsorption processes.
99.9
99.8
2
1
0.5
0.2
0.1
0.05
I I I I I I I
DROPLET DIAMETER Id) cm < 10
Figure 8: Schematic of Experimental Arrangement
Figure 9: Droplet Size Distribution for Standard Tween 80
Stabilized Kerosene Emulsions.
These curves are presented in Figure 10. In this figure, the
oil concentration of the effluent from the column is plotted
against the ratio of the cumulative volume of the oil feed to
the bed void volume. This ratio is directly proportional to
time since inlet oil concentration and feed rate were kept
constant. Note that before breakthrough, the oil content of
the effluent is 3 to 4 orders of magnitude smaller than the
oil content of the feed emulsion. The scatter in the data is
due to the fact that 10 ppm approached the limit of
resolution of the analytical method. Note also that the
volumetric flow rate is high, ranging from over 60 to 300
bed volumes/hr.
After saturation was obtained, the magnetic field was
turned off and concentrated oil in the bed was released into
the exit stream by the incoming emulsion. The first flush
samples were concentrated oil in water emulsions that
contained from 20% to over 70% of oil on a volume basis.
The oil concentration of the outlet then decayed with time
until the outlet concentration of oil was equal to the oil
concentration of the inlet emulsion. This occured by
passing less than five bed void volumes of feed emulsion.
Oil Removal from Tanker Ballast Water
The magnetic separation technique appears to have
application to a wide variety of separation problems
encountered by the petroleum industry, including both
-------
RECOVERY WITH MAGNETIC LIQUIDS 425
g
s
I
3
o
O 10"
u
BED VOLUME 13
FLUID MAG. 10
3
»""
0.1 0.10
OIL VOLUME THROUGH BED
BED VOID VOLUME
Figure 10: Magnetic Oil Removal with a Nor.-Coalescable Emulsion.
EMPTY TANK
WITH OIL COATED WALLS
NOMINAL OIL CONTENT = 0.17. OF TANK CAPACITY
marine and industrially-based oil emulsions, where initial
access to the two immiscible phases is available before
emulsion formation. An obvious example is oil removal
from emulsions formed during "load on top" procedures
for cleaning tanker holds as well as from ballast water
emulsions formed within tanker holds when this procedure
is not used.
As an example, consider oil-water separation from
tanker ballast water emulsions (See Figure 11). After
unloading, the oil clinging to the sides of a hold is sprayed
with jets of ferrofluid. The hold is then cleaned and/or
filled as in normal operation. During transit (or at port), the
resulting emulsion (typically one per cent oil) is processed
through one of two units operating in parallel similar to the
magnetic device described above. Extensive bench-scale
testing shows that the water effluent will meet or better
existing and proposed standards (less than 100 ppm oil).
After a period of time, depending upon device size, flow
rate and ferrofluid-oil ratio, the device will "saturate" and
the flow is diverted to the second unit. At this point, the
FERROFLUID STORAGE
MIXING SPRAY NOZZLE
MAGNETIZATION OF RESIDUAL
OIL IN TANK BY MIXING WITH
FERROFLUID
LEGEND
XO - OPEN VALVE
Xc - CLOSED VALVE
Q - ON BOARD OIL TRANSFER PUMP
BALLASTING OF TANK WITH SEA WATER
FORMATION OF OIL-WATER EMULSION
SEA WATER
MAGNETIC SEPARATORS
BED A BED B
ON STREAM REGENERATING
I T
i
SEA WATER FOR BACK FLUSH
(TO CLEAN TANK OR DISCHARGE)
DE-OILING OF BALLAST WATER
SLOP TANK
FOR CONCENTRATED
OIL/WATER EMULSION
Figure 11: Process Description for Magnetic De-Oiling of Ballast! Water.
-------
426 PHYSICAL REMOVAL ...
ballast water emulsions encountered with crude and fuel
oils; hence, it represents an overly conservative estimate.)
Total capital cost, including auxiliary pumps and instru-
mentation for a fully automated unit is estimated to be less
than $100,000. Ferrofluid will be required in the ratio of 1
part to ISO parts oil. At a projected price of $1.00 per
gallon, a total operating cost will be less than one cent per
gallon of oil processed. This is significantly less than
prevailing price of crude oil which is SB/barrel or roughly
7« per gallon. Theoretical and experimental studies show
that, to a good approximation,
emulsion flow rate _
ferrofluid-oil ratio
= constant
if all other variables are fixed. Hence, the same device could
operate at 500 gpm with a 1:30 ferrofluid-oil ratio at an
operating cost of 3< per gallon of oil. The optimum
device is "regenerated" by shutting off the magnetic field.
The effluent removed during this operation will contain up
to 50-80% oil as well as other particulates such as wax,
sand, etc. This concentrated emulsion is stored in a small
slop tank. It may also be reprocessed in a smaller device or
easily broken by conventional means. The device is now
ready for the next cycle.
Projected system economics for a 100 gpm system are
based upon laboratory bench-scale experiments with a fine,
highly stable emulsion containing a volume-mean diameter
of about 4.5 microns. The following estimates are based
upon virtually absolute removal of all droplets larger than
about 1.5 microns. (Note that this is significantly finer than
operating conditions would depend upon an economic
trade-off between larger equipment (greater throughput)
with lower ferrofluid usage and smaller equipment (hence
lower capital cost) with greater ferrofluid usage and higher
operating cost.
It is useful to compare the projected costs of the two
magnetic separation processes described above. These are
essentially parallel systems which consider the removal of
oil from water before contact with the ocean, and after
contact with the ocean. This comparison exemplifies the
well worn saying, "an ounce of prevention is worth a pound
of cure."
REFERENCES
1. Kaiser, R., and G. Miskolczy, I.E.E.E. Trans. Mag-
netics, MAG-6, (No. 3), 694 (Sept. 1970).
2. Kaiser, R., and G. Miskolczy, J. Applied Physics, 41,
1064 (1970).
3. Rosenweig, R.E., R. Kaiser and G. Miskolczy, /.
Colloid Interface Science, 29,680(1969).
4. Neuringer, J., and R.E. Rosensweig, Physics of
Fluids, 27,1927 (1964).
5. Rosensweig, R.E., A/.A/4./., 4,1751 (1966).
6. U.S.EJ.A., W.Q.O., "Oil Recovery System Using
Sorbent Material" (RTP) WA 71-531, Washingon, D.C.
20242, Nov. 18,1970.
7. Graham, DJ., Johnson, R.L., and Bhuta, P.G., as
reported in Product Engineering, p. 49, March 1,1971.
8. Turbeville, J.E., as reported in Offshore Technology,
August 1970.
9. Wiegel, R.L., "Oceanographical Engineering", p. 205,
Prentice-Hall, Inc., New York, 1964.
10. Anon., "Man's Impact on the Global Environment",
p. 267, The M.I.T. Press, Cambridge, Mass., 1970.
-------
PHYSICAL-BIOLOGICAL EFFECTS
Chairman: P. Roedet
National Oceanic and Atmospheric
Administration
Co-Chainnan: R. T. Dewling
Environmental Protection Agency
-------
SOME EFFECTS OF OIL POLLUTION IN
AAILFORD HAVEN, UNITED KINGDOM
E. B. Cowell
Field Studies Council, Orielton Field Centre
ABSTRACT
Research on the biological effects of oil pollution and
detergent cleaning operations within the port of Mttford
Haven is described. Observations made on accidental
pillages, experimental field spillages and laboratory investi-
gations confirm that both salt marsh communities and
rocky shores do normally recover from oil pollution acci-
dents but that shore cleaning with emulsifiers can do
serious damage if misused, although recovery follows. The
effects of some new emulsifiers which are up to 1000X less
toxic are discussed.
Chronic pollution damage from refinery discharges has
been identified both in Milford Haven and elsewhere, but it
has been shown that these effects are eliminated if the
outfall pipes are located offshore in locations of good
dispersion and currents.
Long term surveys reveal no widespread long term
damage to the Fauna and Flora of Milford Haven attribut-
able to the development of the oil port.
INTRODUCTION
Britain has few ports capable of handling super tankers.
Milford Haven, even though it lay in the heart of the newly
formed Pembrokeshire National Park filled the require-
ments so well that in 1960 two major oil companies opened
marine terminals there: one serves its own refinery and the
other receives and stores crude oil for transmission to
IJandarcy refinery near Swansea by a 63 mile pipeline. By
1970 the Haven had become Britain's largest oil port, with
a total of 40 million tons handled annually. Two further
references have been built each with its own terminal and
the building of a fourth refinery has just begun. Tankers of
more than 200,000 tons can be accepted in the port.
The development of Milford Haven as an oil port has
resulted in fairly frequent spillages of oil. Spillage fre-
quency is likely to rise as the port expands although the
spillage rate per ton handled has in fact fallen as time
proceeds (Dudley 1970).
1966 .0002%
1967 .0014%
1968 .0002%
1969 .0001%
The present anti-pollution organization of Milford Haven
is extremely efficient but several spillages do reach the
shores each year. Smaller spills are kept off the shores by a
unique system. The oil companies and the Milford Haven
Conservancy Board (the harbour authority) jointly operate
a launch equipped with spray booms and tanks of emulsi-
fier (dispersant). This craft goes into operation as soon as a
slick is sighted, dispersing the oil efficiently and economi-
cally. In the event of large spillages up to five launches can
be brought into action and recently a large tug boat has
been used equipped with spray booms and towing the 'five
barred' gate arrangement designed by the Ministry of
Technology, Warren Springs Laboratory. This equipment is
used to agitate the treated water in the wake of the ship.
An average of 2,500 gallons of emulsifier are used within
the port each month, the responsibility for oil spillages is
argued out after the event and if the culprit cannot be
found, the cost of the cleaning operation is shared.
Until late 1970 the emulsifier used was the highly toxic
B.P. 1002, or its equivalents. Recently only the newly B.P.
1100 has been used which is almost a 1000X less toxic to
most littoral animals (Crapp 1970).
This paper reports work done by the research team of
the Field Studies Council Oil Pollution Research Unit,
Orielton, Pembroke, South Wales, to determine the biologi-
429
-------
430 PHYSICAL-BIOLOGICAL EFFECTS
cal and ecological effects of the pollution of Milford Haven
by oil and the consequences of the cleaning operations that
are used. The research has been divided into three sections.
The first under J. M. Baker is on the effects of oil pollution
and shore cleaning on salt-marsh communities, the second
by G. B. Crapp is on the effects on rocky shores, while the
thud under S. M. Ottway is on the effects of oils on rock
pools. I have been responsible for some of the direct
research and for its general direction.
THE EFFECTS OF SINGLE OIL
SPILLAGES ON SALT MARSHES
In Britain, salt marsh communities colonise the mudflats
of sheltered shores and tidal estuaries between Mean High
Water Neap tide levels (MHWN) and Mean High Water
Spring (MHWS). These marshes are the feeding grounds of
wild fowl, waders and swans and are vital for the
maintenance and recovery from oil pollution of the
populations of many bird species. They are also involved in
the energy flow systems of related offshore mudflats and
in maintaining estuarine production (Odum & Smalley
19S9, Odum 1961, Teal 1962). Salt marshes are also
economically important since they stabilise and raise the ,
levels of mudflats and make land available for sea defence
and land reclammation (Allen 1930, Ranwell 1967).
METHODS
Observations following oil spills were made at Milford
Haven, S. W. Wales, by Cowell 1969, Baker 1970, Cowell &
Baker 1969, and experimental simulated oil pollution has
been done by spraying at different times of year. Experi-
mental emulsifier cleaning has also been tried. Salt marsh
turves kept in an unheated greenhouse have been used for
comparing the effects of different oil fractions and volumes
and emulsifiers. Changes in vegetation were studied by
cover estimations using a points frame (Tiver & Crocker
1949) while productivity measurements as dry weight;
population counts and infra red photography were also
used.
RESULTS
Oil adheres firmly to the plants and very little is washed
off during successive tides. Under oil films, leaves may
remain green initially but eventually yellow and die. Plants,
however, recover by producing new shoots, a few of which
can usually be seen within 3 weeks of pollution unless large
quantities of oil have soaked into the plant bases and soil.
Seedlings and annuals rarely recover directly. In the long
term, however, recovery from crude oil spillages has been
observed many times. (Buck & Harrison 1967, Ranwell
1968, Smith 1968, Stebbings 1968, Cowell & Baker 1969).
The evidence from observations of both accidental and
experimental spillages is that marshes recover well from
single oil spillages. A badly oiled marsh at Bentlass on the
Pembroke River which was severely damaged after the
Chryssi P. Goulandris tanker accident in 1967 (Cowell
1969) was virtually completely recovered two years later
(Cowell & Baker 1969).
Experimental work has shown that oil toxicity varies
widely with the type of oil spilled, being higher where the
aromatic content is high especially the fractions boiling
below 149°C (Ottway 1970).
Damage to salt marsh plants from crude oil also varies
with season, being less severe in winter spillages than in
spillages occurring in spring and early summer.
SINGLE SPILLAGES ON ROCKY SHORES
The effects of spillages on the intertidal zone of rocky
shores were investigated experimentally using simulated
spillages in the field and by following the changes occurring
in the aftermath of accidental spillages. Recordings taken
were comprehensive and included those made using the
Crisp and Southward Abundance scale (1958), the modifi-
cation of this by Ballantine (1961) and counts and
measurements of length size frequency distributions in the
case of Patella spp. (Limpets) and Balanus and Chthamalus
spp. (Barnacles) Crapp 1969, Crapp 1970.
The field trials snowed that most littoral species are
resistant to toxic oils, even when spilt at intervals of one
month. Some littoral gastropod snails, notably Littorina
neritoides L., L. saxatilis and L. obtusata, are affected by
thicker oils. These are all small species and a thick layer of
oil on the shell effectively increases the volume and mass of
the animal. When this occurrs wave action is more likely to
dislodge it from the rock.
Laboratory experiments on the toxicity of oils per-
formed by Ottway (1970) revealed wide variation in the
toxicities of different oils and oil fractions using standard-
ised tests described by Crapp (1970) and Ottway (1970).
High mortalities recorded in the laboratory were not found
under field conditions due to the evaporation of many
toxic low boiling aromatics and the dilution of those
fractions which pass into solution. Work on the toxicity of
soluble fractions is continuing but so far only low toxicities
are recorded from solutions made under simulated field
conditions using vented containers.
CHRONIC POLLUSION AND
SUCCESSIVE SPILLAGES
Cowell (1970) has described two possible forms of
chronic oil pollution. Firstly, that resulting from successive
spillages occurring at a frequency greater than that allowing
complete recovery, and secondly that resulting from the
continuous discharge of low levels of oil in effluents such as
those from refinery outfalls, ballast water treatment plants,
etc.
Successive Spillages
On salt marshes successive spillages were studied by
Baker (1970). Plots sited on three different types of salt
marsh community were set up both at Bentlass, Milford
Haven and marshes on the Gower Estuary (Glamorgan-
shire). Points frame recording and productivity measure-
ments have shown that recovery from up to four successive
-------
EFFECTS IN MILFORD HAVEN 431
75 — O^3
20 - ' ' H\T 1
15 - o o"
10 - A 71
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5~ \ A
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20 - °
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-------
432 PHYSICAL-BIOLOGICAL EFFECTS
The oldest outfall in Milford Haven is sited within a
small bay and discharges from an outfall on the shore at the
level of E.L.W.S. tides. When this sheltered bay was first
examined in 1969 it was surprising to find that the
dominant intertidal species was the exposed shore species
of brown seaweed Fucus vesiculosus. From the bay's
position a limpet/barnacle dominated shore had been
expected with the sheltered shore brown seaweed
Ascophyllum nodosum as the dominant algae.
Early records showed that this shore had originally been
a limpet/barnacle dominated shore. To study the changes
six transects were established up to 450 meters on either
side of the outfall. It was found that several species
occurred in reduced numbers or were absent, especially L.
saxatilis negiecta Littorina neritoides, Monodonta lineata
and Gibbula umbilicalis. The populations of limpets,
especially Patella vulgata and the barnacles Balanus bala-
noides and Chthamaius stellatus were also considerably
reduced on transects 3 and 4. The severely depleted fauna
and flora took the form of a pollution gradient (Crapp
1970).
A second outfall investigated is at a jettyhead and has
been operating for six years and effluent is pumped along
the jetty. The outfall opens at M.L.W.S. and is operated
while the tide is ebbing. No biological changes in the
intertidal zone were found that could be attributed to the
outfall water.
Further investigations were done by tracing water
movements throughout the tidal cycle, and by measuring
dispersion and dilution using a salinometer. For water
movement investigations floats with almost negative buoy-
ancy were designed equipped with marker flags. These were
dropped at the outfalls in groups of ten at regular time
intervals and their positions plotted at varying stages of the
tide.
It was found that at the outfall discharging into a bay at
the shoreline, surface currents away from the outfall are
slow, except in the early stages of ebb and flood tides and
that at some stages, but especially at slack water, some of
the effluent was circulated back to the shore.
At the outfall on the jettyhead, surface currents did not
transport the effluents back to the shore for considerable
distances (up to % mile or more).
Observations were also made on dilutions of the effluent
by measurements of salinity changes using direct readings
taken on a salinity temperature bridge (National Institute
of Oceanography Pattern). The salinity of the area is
normally 32°/oo of salt while that of the effluent was
14°/oo. At the shoreline the influence of the effluent was
detectable but no salinities were lower than 27°/oo. At
most regions just offshore the salinities were 30" /oo. These
salinities were found at low water but as the tide rose the
influence of the effluent decreased.
It was concluded that with effluents containing oil levels
of 20-25 ppm of oil biological damage only occurs if the
effluents are discharged at the shoreline in areas of poor
tidal dispersion, but that effluents discharged offshore at
jettyheads in areas of good dispersion produce no measur-
able biological change (Baker 1970, Cowell 1970, Crapp
1970).
It is interesting to note that as a consequence of these
findings the West Wales River Board is lowering the
permissible maximum levels of oil discharge into Milford
Haven from refinery effluents to 25 ppm and all future
installations must discharge at the jettyhead over the deep
water channels.
EFFECTS OF SHORE CLEANING WITH EMULSIFIERS
Among others the following emulsifiers have been tested
both in the laboratory and the field. B.P. 1002 (a solvent
emulsifier commonly used for cleaning oil), test blends X
(low aromatic content) and Y (high aromatic content) and
B.P. 1100.
Puccinellia/Festuca turf
100 -i A-A-
c
o
"o
en
TJ
O
0)
E
TJ
V
CJ
E
60 -
50 -
AC -
20 -
TJ —
O>
~ 0
Solvent A
B P 1002
O Test blend X
• Test blend v
T I | 1 I I i I I
0 20 40 60 80 100 %
Emulsifier concentration
Effects of emulsifiers and a solvent on PuccinellialFestuca turf.
Puccinellia maritime!
1 week otter treatment
PU?.*- '.r>^*'°_rn9ri*'ma
3 weeks after treatment
100 -
80 -
60 -
40 -
20 -
0 -
100 -i
80 -
60 -
40 -
20 -
o -i
0-8 0
8
/ B R 1100
3"
1 1 1 1 i
o-o o
c
0 O.S. 10239
00
>
1 I i 1 1
100 -i o--p o
80 4 / '
I O
60 i /
40 4 / B R '002
20 -I/
p «
u
oo
1 1 1 1 1
0 20 40 60 83 TOO •/.
100
BO
CO
40
20
0
100
eo
60
40
20
B.R 1100
Emulsifior cone.
Effects of emulsifiers on Puednellia turf.
Figure 3: (After Baker 1970)
D.S. 10239
I
0-0-'. - j
E.P. 1002
0 20 « 60 80 K» "k
Efr.-jlsifier cone .
-------
EFFECTS IN MILFORD HAVEN
433
SALT MARSHES
On salt marsh plants small differences have been
observed between the toxicities of these materials. In all
cases concentrations below 10% were not permanently
damaging and concentrations above 50% killed them. The
toxicity to salt marsh plants depends upon dilution rather
than the absolute amount of emulsifier, e.g., 10 ml of
undiluted emulsifier kills a salt marsh turf 30 cm x 40 cm
but the same amount of emulsifier has no visible effect if
applied as 100ml of 1% solution. In tests with B.P. 1002
and its solvent A260 the solvent alone proved as toxic as
the whole emulsifier. Any hydrocarbon solvent is liable to
penetrate into plants through lipophilic surfaces and
penetration is crucial in determining toxicity. Once inside
the plant it may dissolve in cell membranes and cause loss
of cell sap. There is a relationship between toxicity to salt
marsh plants and dilution. Penetration of undiluted emulsi-
fiers may be as rapid as 20 seconds but the time is greater in
more aqueous solutions, see Figure 3.
ROCKY SHORES
The chief ways of cleaning oil from shores are mechani-
cal removal and washing with solvent emulsifiers. Until
recently most emulsifiers available were highly toxic. Most
of our research has been done with B.P. 1002. In the
laboratory these were applied to test species in the manner
described by Perkins (1968) and Crapp (1970). The animals
were exposed to high concentrations of detergent for 1
hour and this was followed by a recovery period in clean
sea water. Susceptibility varied both between species and
within species at varying times of the year. See Figure 4. In
general the intertidal gastropods were more susceptible in
winter shore cleaning than in summer, e.g., the topshell
Monodonta lineata, a southern warm water species, is most
resistant to detergent treatment in the warmer summer
months. However, the dog whelk Nucella lapilhis, a species
which extends into Arctic waters has a greater resistance in
December than in July or October, Figure 5.
These figures have been compared with observations
made following a spillage in Milford Haven in November
1968 and with the results of field experiments set up to list
the effects of detergent treatment.
The spillage was one of crude oil that went ashore at
Hazelbeach, Milford Haven, a shore which had already been
polluted and cleaned in January 1967. (Nelson-Smith 1968
a, b). Nelson-Smith recorded that although many organisms
were killed, enough grazing animals survived to prevent an
algal flush from covering the shore. Detergent treatment in
1968 was light but the shore had not fully recovered from
an earlier spillage. Three weeks after the cleaning the
number of gastropods was drastically reduced but increased
again by January 1969. Crapp (1970) believes that the
animals on the shore behaved in the same way as those in
the laboratory. Exposure to emulsifier was followed by
retraction into the shell following which the animals were
rolled by water hosing and wave action into deep crevices
-.MAR APR . MAT JU;:i: JULY AUO SEPT OCT NOV DEC JAh FEb" MAR APR MAY JUNE
Seasonal variations in mortalities recorded in Monodonta lineata following exposure to various concentrations of BP 1002 for one hr.
Figure 4a: (From Crapp 1970)
-------
434 PHYSICAL-BIOLOGICAL EFFECTS
9000 10000 90000 COOOO 3300001000000
[from OUff. 19701
Figure 4b: Resistance of Various Intertidal Species to BP 1002
or into the sublittoral zone. Two months later these animals
had recovered and regained their normal position on the
shore. The most susceptible animal proved to be the limpet
Patella vulgata which was reduced from 150 per m2 to 21
per m2. The numbers continued to decline during the
spring and by the time that young were recorded in June
1969 the density had dropped to 5 per m2. This density
was insufficient to prevent an algal flush from developing.
During the spring the shore was covered by a growth of the
green alga Enteromorpha and this was replaced in the
summer by Fucus vesfculosus. The covering of the shore by
Fucus has altered its character completely and the number
of barnacles subsequently declined. This will presumably be
followed by a decline in the numbers of the carnivore
Nucella lapfllus which feeds on barnacles. The same
sequences of events were recorded on detergent treated
experimental plots and following the Torrey Canyon and
Fina Norvege spillages.
> UNEMM
NUCELLA UtPWlJS
Figure 5: Resistance of Two Intertidal Specks to BP 1002 at
Different Times of Year.
All these shores resemble the experimental strip at Port
Erin, Isle of Man, described by Jones (1948) and South-
ward (1964) where limpets were removed intentionally.
The evidence suggests that recovery from damage by B.P.
1002 is a normal successional process and if this is so a time
scale of 10-15 years can be expected before normal
situations are reached.
Work on BJ*. 1100 has shown this new emulsifier to be
almost 1000X less toxic than B.P. 1002. This is a marked
improvement but the material still has some toxicity
particularly to the dominant species Patella vulgata and
Mytttus edulis. We predict that if B.P. 1100 were misused on
the scale which occurred after the Torrey Canyon disaster
then the populations of these species would be markedly
affected. This would of course result in community
repercussions similar to those observed with light treatment
with BJ. 1002.
We are convinced that salt marsh communities should
never be treated with detergents but that rocky shores can
be cleaned with minimal damage provided that the new low
toxicity materials such as B J>. 1100 are used in moderation.
Floating oil slicks are best dealt with before they come
ashore even if the more toxic dispersants are used since
toxicity is related to dilution.
MONITORING BIOLOGICAL CHANGE
IN MILFORD HAVEN
Long term changes in the fauna and flora of Milford
Haven as a result of the oil industry operations are being
recorded using 32 monitoring transects around the shores
of the port. Recording is done using the modified Crisp &
Southward scale described by Crapp (1970). Recording
began before the oil port was established, (Nelson-Smith
1964, Moyse & Nelson-Smith 1963, Nelson-Smith 1967a,
Arnold 1959).
These surveys reveal no long term changes in the flora
and fauna of Milford Haven that are attributable to the
development and operation of the oil terminals and
refineries. The only exceptions to this being damage to two
repeatedly cleaned recreational beaches and to damage
within the immediate vicinity of one refinery outfall pipe
discharging water with an oil content of approximately 25
ppm.
This result is very encouraging if one consideres that
.0001% of the 40 million tons handled is lost into the
harbour and that these losses are treated with emulsifying
agents which until recently have been of very toxic nature.
The port also has the addition of 1,680 barrels of oil from
refinery discharge sources. We conclude that even with the
established toxicity of crude and other oils and the toxicity
of detergent materials the damage to intertidal fauna and
flora is minimal when most oil spillages are treated while
still afloat ensuring that dilution to that below toxic levels
can take place.
This work was supported by grants from the Jubilee
Fund of the Institute of Petroleum, and the World Wildlife
Fund-Torrey Canyon Appeal. The work is registered as
-------
EFFECTS IN MlLFORD HAVEN 435
part of the International Biological Programme Section No.
UK/PM/5.
REFERENCES
1. ALLEN, H. H. 193QSpartina townsendii, a valuable
grass for reclammation of tidal mud-flats. 2 Experience in
New Zealand. N.Z. JLAgric. 40:189-96.
2. ARNOLD, D. C. 1959 Report of work undertaken
during tenure of a Research Fellowship in marine biology at
Swansea 1958-59. Development Commission, pp. 71 (type-
scripts) 1954.
3. BAKER, J. M. 1970 The effects of a single oil
spillage; in The ecological effects of oil pollution on littoral
communities. Proc. of symp. Nov. 31st & Dec. 1st 1970,
ed. E. B. Cowell, Inst. of Pet. London (in press).
4. BAKER, J. M. 1970 Successive spillages; in the
ecological effects of oil pollution on littoral communities.
Proc. of symp. Nov. 31st & Dec. 1st 1970, ed. E. B. Cowell,
Inst. of Pet. London (in press).
5. BAKER, J. M. 1970 The effects of a single oil
spillage, in The ecological effects of oil pollution on littoral
communities. Proc. of symp. Nov. 31st & Dec. 1st 1970,
ed. E. B. Cowell, Inst. of Pet. London (in press).
6. BAKER, J. M. 1970 Refinery Effluent; in The
ecological effects of oil pollution on littoral communities.
Proc. of symp. Nov. 31st & Dec. 1st 1970, ed. E. B. Cowell,
Inst. of Pet. London (in press).
7. BAKER, J. M. 1970 Oil and salt marsh soil; in The
ecological effects of oil pollution on littoral communities.
Proc. of symp. Nov. 31st & Dec. 1st 1970, ed. E. B. Cowell,
Inst. of Pet. London (in press).
8. BAKER, J. M. 1970 Comparative toxicities of oils,
oil fractions and emulsifiers; in The ecological effects of oil
pollution on littoral communities. Proc. of symp. Nov. 31st
& Dec. 1st 1970, ed. E. B. Cowell, Inst. of Pet. London (in
press).
9. BALLANTINE, W. J. 1961 A biologically-defined
exposure scale for the comparative description of rocky^
shores, Field Stud. 1(3)1-19.
10. BUCK, W., & HARRISON, J. 1967 Some prolonged
effects of oil pollution on the Medway estuary. Ann. Rep.
Wildfowl Ass. 32-33.
11. COWELL, E. B. 1969 The effects of oil pollution on
salt marsh communities in Pembrokeshire and Cornwall.
J.appl.Ecol. 6:133-42.
12. COWELL, E. B. 1970 Chronic oil pollution caused
by refinery effluent water. Water Pollution by Oil Ed. P.
Hepple, Inst. Pet. London. Appendix p.380-381.
13. COWELL, E. B., & BAKER, J. M. 1969 Recovery of
a salt marsh in Pembrokeshire, S. W. Wales from pollution
by crude oil. Biol. Conserv. 1:291-5.
14. COWELL, E. B., BAKER, J. M. & CRAPP, G. B.
1970 The biological effects of oil pollution and oil littoral
communities, including salt marshes. Paper No. E.ll,
F.A.O. Technical Conference on marine pollution and its
effects on living resources and fishing, Rome Italy, Dec.
1970
15. CRAPP, G. B. 1970 'The biological consequences of
emulsifier cleaning' in The ecological effects of oil pollution
on littoral communities. Proc. of symp. Nov. 31st & Dec.
1st 1970, ed. E. B. Cowell, Inst. of Pet. London (in press).
16. CRAPP, G. B. 1970 The biological effects of marine
oil pollution and shore cleansing. Annual Report, Field
Studies Council, Oil Pollution Research Unit 1969.
17. CRAPP, G. B. 1970 'Laboratory experiments with
emulsifiers'; in The ecological effects of oil pollution on
littoral communities. Proc. of symp. Nov. 31st & Dec. 1st
1970, ed. E. B. Cowell, Inst. of Pet. London (in press).
18. CRAPP, G. B. 1970 'Chronic oil pollution'; in The
ecological effects of oil pollution on littoral communities.
Proc. of symp. Nov. 31st & Dec. 1st 1970, ed. E. B. Cowell,
Inst. of Pet. London (in press).
19. CRAPP, G. B. 1970 'Monitoring the rocky shore'; in
The ecological effects of oil pollution on littoral com-
munities. Proc. of. symp. Nov. 31st & Dec. 1st 1970, ed. E.
B. Cowell, Inst. of Pet. London, (in press).
20. CRAPP, G. B. 1970 Chapter 2 - the biological
effects of marine oil pollution and shore cleansing. Ph.D.
Thesis, University of Wales.
21. CRISP, D. J., & SOUTHWARD, A. J. 1958 The
distribution of intertidal organisms along the coasts of the
English Channel. J.mar.biol.Assoc.UJC. 37,157-208.
22. DUDLEY, G. 1970 Oil pollution in a major oil port:
the incidence, behaviour, and treatment of oil spills, in The
Ecological effects of oil pollution on littoral communities.
Proc. of symp. Nov. 31st & Dec. 1st 1970, ed. E. B. Cowell,
hist, of Pet. London (in press).
23. JONES, N. S. 1948 Observations and experiments
on the biology of Petella vulgata at Port St. Mary, Isle of
Man. Proc. Lpool.biol.Soc. 55:60-77.
24. MOYSE, J. & NELSON-SMITH, A. 1963 Zonation
of animals and plants on rocky shores around Dale,
Pembrokeshire, Field Stud. 1(5)1-31.
25. NELSON-SMITH, A. 1968a The effects of oil
pollution and emulsifier cleansing on shore life in south-
west Britain. J.appl.Ecol. 5:97-107.
26. NELSON-SMITH, A. 1968b Biological conse-
quences of oil pollution and shore cleansing. Field Stud. 2
suppl. 73-8.
27. NELSON-SMITH, A. 1967a Marine biology of
Milford Haven: the distribution of littoral animals and
plants. Field Stud. 2 pp. 407-434.
28. ODUM, E. P. 1961 The role of tidal marshes in
estuarine production. N.Y. St. Conserv. June-July 1961.
29. ODUM, E. P., & SMALLEY, A. E. 1959 Compari-
son of population energy flow of a herbivorous and deposit
feeding invertebrate on a salt marsh ecosystem. Proc.
Nath.Acad.Sci. U.S.A. 45:617-22.
30. OTTWAY, S. M. 1970 'The comparative toxicities
of crude oils'; in The ecological effects of oil pollution on
littoral communities. Proc. of symp. Nov. 31st & Dec. 1st
1970, ed. E. B. Cowell, Inst. of Pet. London (in press).
31. PERKINS, E. J. 1968 The toxicity of oil emulsifiers
to some inshore fauna. Field Stud. 2 suppl. 81-90, ed. J. D.
Carthy&D.R. Arthur.
-------
436 PHYSICAL-BIOLOGICAL EFFECTS
32. RANWELL, D. S. 1967 World resources ofSpartina
townsendii and economic use of Spartina marshland.
Jappl.Ecol. 4
-------
THE INFLUENCE OF OIL AND DETERGENTS
ON RECOLONIZATION IN THE
UPPER INTERTIDAL ZONE
Dale Straughan
Allan Hancock Foundation
University of Southern California
ABSTRACT
Recolonization of asbestos fouling plates treated
variously with oil and detergents is dependent on the season
of the year. The presence of oil favors C. fissus settlement
but retards algal settlement.
INTRODUCTION
Following the 1969 oil spill in the Santa Barbara
Channel, most of the oil accumulated in the upper sections
of .the intertidal zone. Nicholson and Cimberg (1971) noted
this increasing dosage of oil on the substrate from low tide
to high tide on their transect at East Cabrillo Beach. They
report that the highest intertidal mortality occurred due
apparently to smothering of the small barnacle Chthamalus
fissus. Neushal (1970) and the California Department of
Fish and Game (1969) reported similar findings.
The policy in the United States is not to use
dispersants to treat oil at sea or on the beaches except
under special circumstances such as an acute fire hazard.
Hence mechanical methods were used to remove oil along
Santa Barbara beaches. The most common method was to
soak up the oil with straw and then remove the oily straw.
This gives rise to two problems—what to do with oily straw
and how to remove all the oily straw from between the
crevices of rocks. The latter is a virtually impossible task.
This oily straw remains in inaccessible areas over two years
after the spill! Oil that was not cleaned from rocks in 1969
is also still present.
Nicholson and Cimberg (1971) first noted Chthamalus
fissus settlement on oil originating from the January 1969
oil spill in November, 1969. This barnacle settled both on
oil and the oil-straw mixture. However, there is an
importance difference. Oil forms a hard substrate while the
oil-straw mixture forms a crumbly substrate which is
eroded away by the sea. When the oil-straw mixture is
eroded away, organisms including C. fissus that had settled
on this mixture, are also eroded away. This causes a further
delay in the complete recolonization of the area. Hence, it
is very important in the recovery of an area, that if straw is
added to oil, all of the oil-straw mixture is removed.
In some areas, it is impossible to guarantee complete
removal of this oil-straw mixture. Under conditions such as
these, it may be desirable to use a detergent to clean up the
oil. While this may cause a higher initial mortality among
intertidal organisms due to the use of detergents, a faster
recolonization and recovery rate in the area could outwiegh
the initial loss. This paper presents the first in a series of
experiments designed to investigate problems of recovery in
the upper intertidal zone after an oil spill. Data on the
effects of oil, and oil and dispersants on recolonization are
presented. Part of the present controversy over detergent
use involves the pros and cons of water base and petroleum
base detergent. In this study three water based and two
petroleum based products were used. BP 1002 was used
after the "Torrey Canyon" disaster and is used here to
provide some baseline for comparison with otherr work.
Materials and Methods
Asbestos plates with one surface grooved or pitted and
the other surface flat with only a slight roughness in
texture, were used for all experiments. All plates, with one
exception, were gray in color. The plates were suspended in
a series of five frames under the jetty at the Santa Catalina
Marine Laboratory. The ridged or grooved surface of all
plates faced the shoreline. Asbestos plates were chosen as
437
-------
438
PHYSICAL-BIOLOGICAL EFFECTS
they provided the best artificial substrate which was
capable of absorbing oil in a way similar to the surface of
rocks.
Santa Barbara crude oil from the Dos Cuadras Offshore
basin was used in all oil experiments. Five detergents A -
BP1100, B - BP1002, C - Poly-complex All, D - Corexit
7664, E - Corexit 8666 were used. Polycomplex A 11 and
Corexit 7664 (C and D) were both used in the Santa
Barbara Chanel after the 1969 oil spill (Straughan, 1971a).
Tom Gaines (1970) reported that the detergents used after
the Santa Barbara oil spill were ineffective at sea. BP1100
(A) is a new product of low toxicity and is the only one of
the products recommended by the manufacturer for use on
shore. Corexit 8666 (E) is a water based product with a
similar toxicity level to the petroleum based BP1100 (A).
Two types of experiments were conducted:
1. the effects of oil alone
2. The effects of oil and detergents.
Plates in (1) were 80x100 mm and in (2) they were 80x120
mm.
1. The effects of oil. Half of each plate was soaked in
oil for a known period and dried outside for 24 hours
before being submerged. In all except one experiment, the
experimental portions were soaked in oil for 48 hours. In
one experiment some experimental surfaces were soaked in
oil 1, 2 and 6 days to compare effects of different amounts
of oil on colonization.
2. The effects of detergents and oil. The lower half of
each plate was treated as in the "oil alone" experiments,
and the right vertical half was scrubbed with detergent. This
means each plate had four types of surfaces, the upper
section was all unofled but half of it was treated with
detergent and half not treated with detergent, while the
lower section was oiled and half of it was treated with
detergents and half not treated with detergents.
Detergents were applied within an hour of surfaces
being covered by the rising tide in accordance with one
(BP) manufacturers instructions. All instructions of the
application of detergents mentioned that oil and detergent
should be well mixed. To simulate this mixing the detergent
was applied with a small brush. It has since been suggested
that application with a spray would be a better simulation.
two days is given in Table 2. No Chthamalus settlement was
recorded on these plates between the end of July and the
beginning of January. This is not due to an insufficient
period of submergence because these sets of plates with no
Chthamalus settlement were submerged 65 and 170 days
respectively while a plate submerged between April and
June bore a Chthamalus settlement within 73 days. Hence
this may be regarded as a seasonal effect. There was some
algal cover on all control plates. There was no algae on the
oiled plate examined after 65 days while on all other dates
there was less algae on the oiled plates than on the control
plates.
The algal abundance and density of Chthamalus on
controls and on fouling plates soaked in oil for 1,2, and 6
days respectively is given in Table 3. There was an inverse
relationship between the number of Chthamalus present
and algal cover on the fouling plates. With one exception
there is a direct relationship between the density of
Chthamalus settlement and number of days the surface was
soaked in oil and an inverse relationship between the
percentage of algal cover and the number of days the
surface was soaked in oil. There was no visible oil, no algae
and a very high density of Chthamalus, on this plate.
Black oil was visible on all oiled plates examined after
65 and 73 days, but not on plates examined after 255 and
335 days.
Effects of Oil and Detergents
These experiments were commenced July 23,1970 and
the results presented in Table 4 describe the condition of
these folding surfaces on January 8, 1971. No Chthamalus
had settled on these surfaces by this date. On both oiled
and unoiled surfaces in this experiment there is no
difference between areas treated by detergent and those not
treated by detergent. However, there is consistently more
algal growth on unoiled than on oiled surfaces. Oiled
surfaces treated with detergents in series A and E bore no
algal growth at all.
While black oil was visible on all oiled surfaces on
January 8, 1971, plates B, C, D had a few apparently clean
areas.
Results
Effects of Ofl
Oil came ashore at Santa Catalina Island in the New
Year of 1970. On July 23, 1970 counts were made of C.
fissus on adjacent oiled and unofled upper horizontal and
vertical surfaces on rocks shaded by the jetty at the Santa
Catalina Island Marine Laboratory. In general, the
Chthamalus population was denser on the oiled than on the
unoiled surfaces (Table 1).
The algal abundance and density of Chthamalus on
controls and on fouling plates previously soaked in oil for
Table 1. Comparison of Density of C. fissus on Oiled and
Unoiled Rock Surfaces. Areas are of Equal Size and Same
Surface Angle.
Area
(sq.m)
100
250
900
1000
150
400
400
Density of C ftssus
Oiled Surface Unoiled Surface
0.25
0.2
0.77
0.03
0.2
0.135
0.2
0.3
0.105
0.44
0.015
0.066
0.075
0.125
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THE INFLUENCE OF Oil
439
Table 2. Number of C. fissus and Algal Cover on Oiled and
Unofled Surfaces
Date
July 29, 1969
-Oct. 2, 1969
No. days
65
225
335
73
170
Algal
Unofled Oiled
July 29, 1969
-April 10,1970
July 29, 1969
-June 29, 1970
April 17, 1970
-June 29, 1970
July 23, 1970
-Jan 8, 1971
-No algae; + thin layer of algae in hollows only;
'rH- thick layer of algae on hollows and ridges
C. fissus
Unofled Oiled
1
0
83
22
0
Months Submerged
JFMAMJJASOND
0
67
126
53
0
thin layer of algae on hollows and ridges;
Table 3. Number of C. fissus and algal cover on unofled
plates and plates soaked in oil 1,2, and 6 days. Plates were
submerged April 17 to June 29,1970.
Algae C fissus
Unofled -H- 22
Oiled 1 day
Oiled 2 days
Oiled 6 days
-H-
+
+
+
35, 240
53,56
127,150
+ thin layer of algae on part of the plate;
++ thin layer of algae on all the plate
Discussion
The results of the experiments provide data which
support the ideas that the rate of recovery is dependent on
the season of the year when the spill occurs. One initially
surprising result is that settlement of CTztfza/amMS was more
abundant on oiled than unofled surfaces. After any
components toxic to settling Chthamalus are lost, this may
be explained by either one of or both of the following
reasons. Most fouling organisms including all barnacles that
have been studied, settle more abundantly on a black
surface than a light surface. Hence settlement could be
more abundant on a black oiled asbestos surface than a
light unofled asbestos surface. There is also an inverse
relationship between algal cover and density of Chthamalus.
The ofl inhibits algal growth on an area leaving it available
for Chthamalus settlement. This means that a layer of ofl in
an upper intertidal area could change the community in an
area from one dominated by small algal species grazed on
by species such as Littorna to a community dominated by
the barnacle Chthamalus.
Data on the effects of ofl and detergents showed that
the presence or absence of ofl on a surface was more
important than treatment with detergent. While these tests
were not efficiency tests for detergents, it should be noted
that there was less ofl visible on plates B, C, D, than on the
other plates and that these were the only plates that bore
algal growth on the oiled surfaces. However, no difference
was detected between surfaces treated and untreated with
detergents. One can only assume that even though care was
taken to only apply detergent to half the surface of the
plate, splash and washing by the tides spread the detergent
over the whole plate. These experiments must be repeated
ensuring that no detergent reaches the control areas.
The data presented here suggests that leaving an oiled
surface untreated in upper intertidal areas in the Santa
Barbara Channel favors recolonization by a Chthamalus
dominated community while removal of the ofl would
favor recolonization by an algal - herbivore dominated
community. Under normal conditions, in the absence of oil,
there is a continuing flux between these communities. If an
algal dominated community is heavily grazed or damaged
by sand abrasion during a storm, it may be replaced by
either another algal dominated community or a Chthamalus
dominated community depending which organisms are
settling when the substrate is exposed. The reverse is also
true.
These experiments were conducted on relatively small
isolated asbestos surfaces. The communities formed on
these surfaces are limited by the size, isolation, and
composition of the substrate. These communities are
probably less complex than the type of community that
would normally be established on the orcky shores. Further
work is required to establish the relationship between the
data obtained on experimental surfaces and conditions on
the natural substrate.
ACKNOWLEDGEMENTS
The research was partially supported by a grant
(GH-89) from the National Sea Grant Program, U.S.
Department of Commerce to the University of Southern
California. I wish to particularly thank Dr. Russell Zimmer,
-------
440 PHYSICAL-BIOLOGICAL EFFECTS
Table 4. Algal cover 170 days after fouling plates treated
with oH and detergents on July 23,1970.
BP 1100
BP 1002
Polycomplex All
Corexit 7664
Corexit 8666
No 09
Detergent No Detergent
Oil
Detergent No Detergent
- no algae; J
and ridges;
thin layer algae in hollows only; ++ thin layer algae on hollows
thick layer of algae on hollows and ridges;
Resident Director of the Santa Catalina Marine Laboratory
and Larry Loeper for their assistance. I also wish to thank
the following: Union Oil of California for supplying the oil;
British Petroleum for supplying BP1100 and BP1002;Esso
Research and Engineering Company for supplying Corexit
7664 and Corexit 8666; and Guardian Chemical
Corporation for supplying Polycomplex All.
REFERENCES
California Department of Fish and Game (1969). Santa
Barbara oil leak. California Department of Fish and Game
Interim Report, December 15,1969.
Gaines, T.H. (1970) Pollution control at a major oil
spill. Paper presented at the International Conference on
Water Pollution Research, San Francisco, July, 1970.
Neushal, M. (1970) Effects of Pollution on
Populations of Intertidal and Subtidal Organisms. Paper
presented at Santa Barbara Oil Symposium, Santa Barbara,
December 17,1970.
Nicholson, N.L. and Cimberg, R.L. (1971) The Santa
Barbara oil spills of 1969, a post-spill survey of the rocky
intertidal. In Biological and Oceanographical Survey of the
Santa Barbara Channel Oil Spill, 1969-70: 325400. Publ.
Allan Hancock Foundation.
Straughan, D. (1971) Introduction. In Biological and
Oceanographical Survey of the Santa Barbara Channel Oil
Spill, 1969-70: 1-10. Pub. Allan Hancock Foundation.
-------
SOURCES AND BIODEGRADATION OF
CARCINOGENIC HYDROCARBONS
Claude E. ZoBell
Scripps Institution of
Oceanography
University of California, San Diego,
LaJolla, Calif.
ABSTRACT
Carcinogenic hydrocarbons (CHC) are widely
distributed in air, soil, marine mud, water, oils (vegetable as
well as mineral), and other materials. Most organisms
appear to contain little or no CHC, but from 1 to more
than 1,000 w?/kg has been detected in certain plants and
animals. A major source of CHC is the combustion or
pyrolysis of carbonaceous materials, including fossil fuels,
organic refuse, forest fires, etc. Airborne, liquid, or solid
pollutants tend to find their way into soU, streams, lakes,
and the sea. Pertinent to the problem of oil spills is the
quantity of CHC contributed by such spills as compared
with that from aerial transport, terrestrial drainage,
biosynthesis of CHC, and other sources.
Evidence is presented for the synthesis of carcinogenic
hydrocarbons by various species of bacteria, algae, and
higher plants. Although some may be retained by their
tissues, a good many animals metabolize various
carcinogenic hydrocarbons and excrete the oxidation
products. In most aquatic environments as well as in moist
aerobic soil, bacteria bring about the degradation of CHC.
INTRODUCTION
Carcinogenic hydrocarbons, including 3,4-benzpyfene,
various benzanthracenes, and other polycyclic or
polynuclear aromatic hydrocarbons (PAH) appear to be
widely distributed in the sea as well as in river water and
soil. The PAH content of marine plankton, seaweeds, fish,
shellfish, and several other classes of invertebrates ranges
from nil in most specimens to more than 500 Mg/kg in a
few. Up to 3,000 ug/kg of PAH has been found in certain
marine mud samples from coastal waters. Certain
investigators have attributed the PAH content of aquatic
organisms and bottom deposits to oil spills, but
biosynthesis, aerial transport, and terrestrial drainage seem
to be the principal sources of carcinogenic hydrocarbons in
aquatic environments.
What are Carcinogenic Hydrocarbons?
Most of the so-called carcinogenic hydrocarbons are
complex polycyclic compounds consisting of from four to
seven unsaturated benzene-ring structures. The capacity of
such compounds to induce cancer has been tested in
susceptible experimental animals by various investigators.
1,19,20,22,37,92 Among the thousands of closely related
hydrocarbons which have been tested for carcinogenicity,
only a few have exhibited any tendency to induce cancer.
Whether these potentially carcinogenic compounds induce
cancer depends upon the diet, sex, species, strain, age, and
treatment of the experimental animals. Dosage, mode of
administration and repetitive application influence
results.42 In several species the latent period may range
from a few days to several years.
According to Heidelberger,38 the following are the
most active carcinogenic hydrocarbons, listed in order of
decreasing potency:
20-Methylcholanthrene
9,10-Dimethyl-l ,2,5,6-dibenzanthracene
9,10-Dimethyl-l ,2-benzanthracene
3,4-Benzpyrene; also called Benzo-3,4-pyrene,
Benzo(a)pyrene or BaP
1,2-Benzanthracene
10-Methyl-l ,2-benzanthracene
1,2,5,6-Dibenzanthracene
Several other polycyclic aromatic hydrocarbons exhibit
some carcinogenic activity, but hundreds of closely ralated
hydrocarbons are inactive. The significance of structure
may be illustrated by pointing out that whereas
441
-------
442 PHYSICAL REMOVAL .
20-Melhyl cholamtiren*
1,2,5,6-Dibenzanthracene
1,2,3,4-Dibenzanthracene
3,4-Benzpyrene
1,2-Benzpyrene
Figure 1. Hydrocarbons on Left are Active Carcinogens Whereas
those on Right are Inactive. The Anthracene and Pyrene Nuclei are
Stippled.
3,4.9, IQ-Dibenzpyre'
300 400 420 460WO 5W3 380 400 42O 46C 50C SW 380
W*VEIWTH (mm
Figure 2. Fluorescent Curves of Some Common Carcinogenic
Hydrocarbons (after Thomas et a/. 97
1,2,5,6-dibenzanthracene (Figure 1) is a potent carcinogen,
1,2,3,4-dibenzanthracene is carcinogenically inactive.83
* Similarly, whereas 3,4-benzpyrene is a highly potent
carcinogen, 1,2-benzpyrene is inactive (Figure 1). For
further information on the chemical structure and potency
of carcinogenic hydrocarbons see the
References. 1,23,25,36,92
Analytical Methods
The kind and quantity of PAH occurring in various
materials was determined by extracting samples with
spectroscopic grade ether, chloroform, or heptane.
Appropriately diluted or concentrated (by distillation) 5-A/l
aliquots were applied to acetylated strip paper. From 40 to
80% acetic acid was used to give different degrees of
separation. After 4 to 24 hours development, the
' fluorescent emissions were measured with a Beckman
Model DU spectrophotometer having a photomultiplier
attachment, using U-V irradiations.24,97
Figure 2 shows fluorescent curves for six different
carcinogenic hydrocarbons. Note that each curve has three
peaks or energy maxima.
Occurrence of Carcinogenic Hydrocarbons in Nature
Relatively little is known about the natural occurrence
of carcinogenic hydrocarbons. For the most part the
concentrations are very low, generally much too low to
induce cancer except when animals were subjected to
continuous and prolonged exposure to various tars, greases,
oils, soots, and certain other combustion products. Only
after the carcinogenic compounds were identified and
chromatographic techniques (mainly gas or paper
chiomatography) were perfected has it been practical to
look for such compounds in air, water, soil, plants, animals,
vegetable oils, mineral oils, and other materials.
Attention has been focussed mainly on looking for
3,4-benzpyrene and certain benz- or dibenz-anthracenes,
because these highly potent carcinogens seem to be quite
widely distributed in nature as well as in many man-made
products.The latter include smoked fish.45 smoked meat,81
cooked sausages,26 charred meat,45,51 internal
combustion engine exhaust ,39,100 tobacco
smoke,27,43,101 and urban air.69,86,87,97
PAH Content of Mineral Oils. Samples of crude oil
from the Persian Gulf, Libya, and Venezula were found by
Graf and Winter32 to contain 400. 1,320, and 1,600 jug/kg
respectively of 3,4-benzpyrene (BaP). The BaP content of
unused motor oil was 26 Mg/kg as compared with 5,800
Mg/kg BaP in the motor oil after being used in an engine for
about 1,400 miles.
BaP as well as a variety of 1,2-benzanthracenes,
1,2-benzphenanthrene (chrysene), diphenylmethane
(fluorene), phenanthrene, and dibenzthiophene have been
demonstrated in Kuwait crude oil. 18,67 The PAH content
of catalytically cracked oils has been reported41 to be
appreciably higher in fractions boiling above 670 F
(354°C) than in the crude stocks. Napthenic or asphalt-base
oils generally have much greater carcinogenic potency than
paraffin types.5,67
The total PAH of crude oils is rarely as much as 0.1%,
of which only a small fraction consists of carcinogenic
hydrocarbons, but pyrolysis may result in substantial
increases in the PAH content.2,94
PAH Content of Vegetable Oils and Plants. The PAH
content of unrefined vegetable oils ranges from less than 10
to more than 3,000 jug/kg.3,35 Slowly filtering the
vegetable oils through activated charcoal removes most of
the PAH. Table 1 shows the quantities of 3,4-benzpyrene
found in 63 unrefined samples of 9 different vegetable oils.
-------
CARCINOGENIC HYDROCARBONS 443
Table 1: 3,4 - Benzpyrene
Content of Crude Vegetable Oils (Mg/kg)35
Kind of Oil
Lowest
Highest
Average
Coconut 1 '
Sunflower i
Palm kernel
Rapseed
Peanut
Soybean
Unseed
Cottonseed
Palm (
7.9
5.1
.3
.3
.3
.5
.3
.0
).6
48.4
15.3
6.0
4.0
2.7
1.9
1.5
2.2
2.4
43.7
10.6
4.1
2.8
1.9
1.7
1.4
1.4
1.2
Binet and Mallet4 demonstrated the occurrence of
3,4-benzpyrene in forest soil and associated vegetable
materials in amounts as follows:
Forest Soil
Hypnum moss
Polyporus fungus
Climbing ivy
Various mosses
4 to 8 Mg/kg
3 to 46 "
6 to 7 "
9 to 85 "
9 to 19 "
Fallen oak leaves were found by Mallet^ to contain up to
300 Mg/kg of 3,4-benzpyrene. At first Mallet and associates
interpreted this as indicative of aerial pollution of plants by
PAH, but more recent observations summarized in a
following section of this paper suggest that many kinds of
plants synthesize PAH.
Mallet and Priou^l reported finding up to 350 Mg/kg of
3,4-benzpyrene in seaweeds and grasses harvested from
Saint-Malo Bay, France. Seaweeds and grasses harvested
from Clipperton Lagoon, where there has been relatively
little pollution, contained an average of 440 Mg/kg of
3,4-benzpyrene.71 Both values are reported on a dry-weight
basis.
Investigations52,53,59,60,62,71,77 in widely scattered
regions have demonstrated the presence of from 2 to more
than 1,000 Mg/kg of 3,4-benzpyrenein numerous samplesof
marine plankton consisting predominatly of
phy to plank ton. The highest concentrations of BaP seem to
occur in plankton samples collected from polluted waters.
BaP Content of Marine Mud and Animals. A large
variety of marine animals (see Table 2) have been shown to
contain appreciable quantities of 3,4-benzpyrene. There
appears to be some correlation between the BaP content of
animals and the pollution of water or bottom deposits, but
certain animals collected off the west coast of Greenland
and from Clipperton Lagoon (regions of little pollution)
contained about as much BaP as the same classes of animals
collected from badly polluted regions.
Piccinetti77 detected BaP in only 35 individual animals
out of 276 individuals representing 53 different species
collected along the Adriatic coast. BaP was found in a
higher percentage of plankton feeders than in higher
trophic level feeders like fish.
The BaP content of marine animals appears to be
correlated with the productivity of the water in which they
live and the degree of terrestrial pollution. In general,
animals living on or in badly polluted bottoms have a higher
BaP content than actively swimming pelagic species. Up to
5,000 jug/kg BaP has been reported in mud samples
collected from highly productive waters subject to
terrestrial pollution (see Table 3). The PAH content of
marine bottom deposits is believed to be derived largely
from terrestrial pollution, including land drainage and
rainfall, and partly from the biosynthesis of PAH by
bacterial and algal growth in the sea.10. 11,44, 73, 74
Sea water from which plankton and other participate
materials have been removed by filtration or centrifugation
generally contains no detectable PAH. The particulate
materials removed from sea water in certain regions may
contain appreciable quantities of BaP and other PAH. The
particulate material was not removed from the Clipperton
Lagoon water samples which were reported7^ to contain
from 34 to 40Mg/kg BaP. The BaP content of various plants
and animals living in the lagoon water ranged from 7.5 to
536 ug/kg.
PAH Content of Terrestrial Streams, Lakes, and Soil.
Unfiltered water samples from Lake Constance and the
Rhine River were found7 to contain 25 different PAH,
including 3,4-benzpyrene (BaP), 3,4-benzfluoranthene,
10,11-benzfluoranthene, 11,12-benzfluoranthene,
1,12-benzperylene, and 1,2-benzanthracene.8 Suspended
solid matter recovered from Lake Constance and Rhine
River water was found to contain around 10 Mg/kg PAH.
Borneff and Fisher^ calculated that Rhine River water
carried around 0.075 mg of carcinogenic PAH per cubic
meter. Such carcinogens could be removed from water by
passage through activated charcoal but not by chlorination.
From 10 to 8,500 Mg/kg of BaP has been reported5^ to
occur in sediments from the Seine River. Assuming an
average load of 25 grams of such suspended solids per cubic
meter of water, the Seine would be carrying from 0.25 to
214 Mg of BaP per cubic meter. An apprecialbe part of the
PAH content is believed to be derived from soil and
atmospheric precipitation. Biosynthesis in the water and oil
pollution of the water are believed to be of secondary
importance.
The occurrence of from 2 to 1,300 Mg/kg of garden or
forest soil has been reported by various
investigators.6,34,55,58,90,104 jn old habitation areas near
Moscow, the concentration of BaP in soil was found by
Shabad^O to be two or three times higher than in new areas
closed to heavy traffic. From 10 to 550 times more BaP
was found in soil in the vicinity of intensive combustion
exhausts than in soil removed from any kind of
combustion:
Soil Sampling region BaP,
Intensive combustion exhausts 19,100
District of oil buildings 346
Another district in Moscow 268
District of new housing in Moscow 105
Suburban area of Moscow 81
Farm field near Moscow 79
Protected water storage area nil
-------
444 PHYSICAL REMOVAL . . .
Table 2: Quantities of 3,4-Benzpyrene Detected in Marine Animals
(Values are expressed as //g/kg dry weight of animal tissue)*
Kind of animals
Geographic location
BaP.ng/kg
Table 3: Quantities of 3,4-Benzpyrene Detected in Bottom Deposits
Material
Geographic location
BaP, jug/kg
Reference
Oysters
n
Mussels
Holothurians
9*
Codfish and shellfish
Fish nad shellfish
Fish and crustaceans
Crustaceans
Isopod crustaceans
Various fishes
Invertebrates
Norfolk, Virginia
French coast
Toulon Roads, France
- Villefranche Bay, France
West coast of Greenland
99 19 99 9,
Saint-Malo Bay, France
Villefranche Bay, France
Arctic Oeean
Clipperton Lagoon
Adriatic Coast, Italy
9» 99 99
10 to 20
1 to 70
2 to 30
up to 2000
nil
16 to 60
3 to 125
nil to 400
nil to 230
up to 530
nil to 900
nil to 2200
17
57
33
49
60
60
61
63
54
70
77
77
Reference
Mud (42 stations)
Mud from pyster beds
Mud (17 stations)
Mud (8 stations)
Mud (12 stations)
Mud and sand
Calcareous deposits
Surface mud
Mud (21 8 samples)
Tyrrhenian Sea
French coast
Mediterranean coast
Villefranche Bay, France
French coast
Villefranche Bay, France
Franch coast
Italian coast
Adriatic coast
1 to 3000
90 to 2840
up to 1800
16 to 5000
nil to 1700
nil to 1700
8 to 59
nil to 2500
nil to 3400
12
33
48
50
57
75
64
89
77
Table 4. Quantities of PAH Resulting From Combustion of One Gallon
of Commercial Gasoline (calculated from data published by Hoffman and Wynder 40)
PAH
mg/gal
1 ,2,5,6-Dibenzanthracene
10,1 1-Benzfluoranthene
3,4-Benzpyrene
1 ,2-Benzanthracene
1 ,2-Benzphenanthrene
3,4-Benzfluoranthene
1,2-Benzpyrene
0.007
0.047
0.088
0.172
0.175
0.179
1.181
2.6
17.4
32.6
63.6
64.7
66.2
426.9
-------
CARCINOGENIC HYDROCARBONS 445
PAH Content of Air and Combustion Products.
Appreciable quantities of BaP and certain other
carcinogenic hydrocarbons occur in city
air.27,39,46,69,86,91,96,100 Based on anajyses Qf ^
samples from several large cities, Falk and Kotin27 record
the following mean BaP contents, expressed as ug of BaP
per 100 cubic meters of air under standard conditions:
St. Louis
London
Cleveland
Chicago
Copenhagen
Oslo
Moscow
54.0
46.0
25.0
15.0
10.3
0.8
0.2
The pyrolysis of various carbon compounds is the
principal source of PAH in the air. From 0.007 to 130
grams of BaP is produced per ton of coal burned by various
firing methods.96 Mostly less than 0.02 grams of BaP is
liberated into the air per ton of coal burned in modern
stokers.
From 0.165 to 570 jig of BaP, plus appreciable
quantities of other PAH, is produced per kg of organic
refuse incinerated.96 Comparable quantities of PAH per
unit of vegetation burned result from forest, brush, and
grass fires.
Meaningful amounts of BaP and other PAH are
liberated into the air incidental to the war, normal
degradation, or incineration of rubber tires. The mean
amount is in the neighborhood of 30 mg BaP per gram of
rubber.28
Highly variable amounts of PAH result from burning
crude oil or products derived therefrom. The amount
depends on the material and the method of its combustion.
Burning fuel oil in steam plants or for heating purposes
results in the liberation of from 0.05 to 50 grams of BaP
per ton of oil.
The exhaust resulting from the combustion of a gallon
of commercial gasoline in an internal combustion engine
was found by Hoffmann and Wyndei-40 to yield an average
of 2.8 grams of aerosols containing appreciable quantities
of PAH. Some of the compounds which were identified are
reported in Table 4. Somewhat smaller amounts of PAH
were produced when oil consumption was low. More than
twice the amounts of PAH recorded in Table 4 were
produced when oil consumption was high.39 Burning a
gallon of fuel in diesel engine results in the liberation of
large amounts of PAH. 100
BaP Content of Tobacco Smoke. The smoke from an
average size cigarette contains about 0.01 /ug of BaP and
larger amounts of certain other carcinogens.27 Cigars and
pipe tobacco also yield PAH in smoke as well as in tars.30
Exclusive of China, the worldwide consumption of
cigarettes in 1968 was 2,500 billion.95 Smoking this many
cigarettes is calculated to yield at least 25 kg of BaP plus
other PAH. This is approximately the BaP content of
25,000 tons of crude ofl, assuming its average BaP content
tobel,000/*g/kg.
Biosynthesis of Carcinogenic Hydrocarbons
PAH Synthesis by Bacteria. Based on API Research
Project 43A work on the part played by bacteria in the
origin of oil, ZoBelll07 reported that anaerobic bacterial.
synthesized appreciable quantities of liquid and solid
hydrocarbons. Extracted from a 5-gallon culture was 1,640
mg of oily material, 367 mg of which consisted mainly of
PAH.
Several species of bacteria have been shown4* to
synthesize 3 ,4-b e nzpy re ne , 3,4- and
10,11-benzfluoranthene, and 1,2-benzanthracene in
glycerin-fructose agar initially devoid of hydrocarbons
(Table 5). The PAH was synthesized intracellulary.
The anaerobic bacterium Clostridium putride was
reported^6,52,53,66 to assimilate lipids associated with
dead plankton, forming from 120 to nearly 8,000 pig BaP
per kg of plankton (dry weight basis). The plankton
contained from nil to 127 jug BaP per kg. Under aerobic
conditions, mixed cultures of bacteria destroyed the BaP,
whereas under anaerobic conditions, bacterial growth
resulted in an increase in the BaP content (Table
6).52,53,66
Clostridium putride was reported ^5to synthesize from
20 to 42 ug BaP per kg of garden sofl at room temperature.
Under similar experimental conditions, Escherichia coli
produced from 22 to 50 ^g BaP per kg of soil enriched with
fatty acids.gr
Bacillus badius was observed?2 to synthesize 0.084 ug
BaP and 0.3 ug of perylene (a weakly active carcinogenic
PAH) per liter of nutrient medium in 7 days of 36 °C.
Somewhat more of these two carcinogens were synthesized
by Bacillus badius in nutrient medium enriched with
lycopene, 0-carotene, naphthalene acetate, and vitamin
Field observations in Clipperton Lagoon by Niaussat
and associates 70,73,74 confirm the microbial synthesis of
BaP under natural conditions in sea water and bottom
deposits.
PAH Synthesis by Algae and Higher Plants. The
freshwater alga Chlorella vulgaris was shown by Borneff et
al 10,11 to synthesize BaP and other carcinogenic PAH
(Table 7). Unequivocal evidence for the biosynthesis of
PAH was obtained by demonstrating the conversion of
Cl4-tagged acetate by algal cultures. Duplicating the results
adds to the significance of the observations. The presence
of Cl4 in the PAH demonstrates that the PAH was
synthesized from acetate by the algae and that it did not
come from extraneous sources such as PAH in polluted air
or culture medium. (The common occurrence of PAH in
air, especially in urban or laboratory air, often makes it
extremely difficult to assay various kinds of samples for
minute quantities of PAH.)
Wheat, rye, and lentil synthesize various PAH.31 These
grains were grown in nutrient solutions prepared with high
purity chemicals which were tested for the absence of PAH.
After the seeds had germinated and the plants had attained
a height of about 10 cm, they were examined for PAH by
-------
446 PHYSICAL REMOVAL .
spectrographic techniques. Compared to control media and
non-germinated seeds, the BaP content in the plants had
increased between 10- and 100-fold.
BaP and certain other carcinogenic hydrocarbons have
been detected in numerous plant species (see section on
PAH Content of Vegetable Oils and Plants). This poses the
pertinent question whether such PAH content represents
extraneous contamination or does it represent synthesis of
PAH by the plants and bacteria. Both processes are
probably widely operative. Before claiming that PAH found
in marine phytoplankton or other vegetation is due to
pollution, it must be established that the higher plants did
not synthesize the PAH.
Biodegradation of Carcinogenic Hydrocarbons
PAH Metabolism by Animals. There is voluminous
literature on the fate of PAH in experimental animals,
mostly mice, rats, rabbits, and dogs. In one of the earlier
comprehensive reviews, YounglO* cjtes 385 references
bearing on the animal metabolism of carbocyclic
compounds, including several PAH. In a more recent article,'
he 103 reviews 71 articles on the oxidation of PAH by rats
and rabbits. Many animal species are known to metabolize
BaP.13,14,15,42,68
During the last decade, improved chromatographic
techniques have facilitated the detection of carcinogenic
PAH and their metabolic products. According to
Boyland,14 who has published nearly 200 papers on this
subject, the slightest change in the molecule of such
substances as benzanthrenes, phenanthrenes, benzpyrenes,
etc. usually renders them non-carcinogenic. In other words,
complete oxidation or degradation of the carcinogen is not
required for its detoxification. Various carboxylates,
hydroxy compounds, quinones, and ethereal sulfates are
common metabolic products of PAH. Ordinarily, such
products are not carcinogenic and they are excreted by
animals under favorable conditions. Such products are
usually more susceptible to further oxidation than the
parent PAH.
The conversion of BaP to various oxidation products
by the action of benzpyrene hydroxylase in weanling rats
has been reported by Conney et at 21 Most of the BaP fed
with chow to cockroaches was excreted in feces.82 Part of
the BaP was metabolized within the cockroaches, because
the input of BaP exceeded the amount excreted plus that
remaining in the tissues and gut.
The annelid worm Tubifex was observed*^ to absorb
BaP from polluted water. Although BaP accumulated in the
worm's tissues in amounts as high as 52 fig/kg dry weight,
some was metabolized by the worms. The metabolism of
various PAH has been demonstrated in a number of
different invertebrate species. However, it has been difficult
to determine whether the PAH was oxidized by the
invertebrates or by microorganisms occurring in the gut or
growing on the integument.
Mciorbial Degradation of PAH. Two potent
carcinogenic hydrocarbons, 1,2-benzanthracene and
1,2,5,6-dibenzanthracene, as well as naphthalene,
anthracene, and phenanthrene were shown by Sisler and
ZoBell93 to be oxidized by large populations of mixed
cultures of marine and soil bacteria. More recent
observations by the author and his associates, using
chromatographic techniques, have demonstrated that
PAH-degrading microorganisms commonly occur in
polluted soil and water. The disappearance of as much as
100 //g of BaP and certain other carcinogenic hydrocarbons
per liter of medium inoculated with 10 ml of polluted
water or mud has been demonstrated after two to four
weeks incubation at 25°C.
Their own observations and some of the extensive
literature on the microbial oxidation of naphthalene and
related compounds have been reviewed by various
investigators.40,47,84,85,98,99,105,106 The susceptibility
of various PAH to microbial degradation is well established.
Urgently needed is more information on the rates of such
degradation where soil or water is subject to pollution with
carcinogenic hydrocarbons. Also needed is more
information on the kinds of microorganisms which are
involved in biodegradation reactions.
Certain bacteria growing in oil-polluted soils were
observed by Petrikevich et al. 76 to accumulate BaP in their
cells. At least part of the BaP was metabolically
transformed. From soil having a BaP content of between
100 and 200 jug/kg Poglazova et ai?8 isolated 17 strains of
bacteria, all of which accumulated BaP in then- cells. When
cultured in nutrient medium treated with about 200 Mg of
BaP per liter, each of the 17 bacterial strains was found to
degrade BaP in amounts ranging from 4 to 82%in 4 months
at 28°C. Degrade means that the bacteria brought about
changes in the quasi-linear spectra of fluorescence in
n-octane. Within 8 days an average of about 40% of the BaP
was degraded. Table 8 shows the amounts of BaP degraded
by various bacteria growing in nutrient medium.79 Mixed
cultures of soil bacteria growing in medium containing
around 200 Mg BaP/kg were found79 to degrade an average
of 85% of the BaP within two months at 28°C. '
Table 5: Quantities of Carcinogenic Hydrocarbons (CHC)
Synthesized per Kilogram of Bacterial biomass
(from Knorr and Schenk44)
Species
CHC
Mycobacterium smegmatis 60
Proteus vulgaris 56
Escherichia coli (strain 1) 50
Escherichia cilo (strain 2) 46
Pseudomonas fluorescens 30
Serratia marcescens 20
Within the range of 20 to 500 jig/liter, the amount of
BaP added to nutrient medium did not greatly influence the
percentage of BaP degraded by Bacillus megaterium
growing in nutrient medium.80 Some representative data
are summarized in Table 8.
-------
CARCINOGENIC HYDROCARBONS 447
Table 6: Effects of Mixed Cultures of Bacteria on
3,4-Benzpyrene (BaP) Content of Dead Plankton52,53
Sample
number
42
49
102
186
43
46
211
212
238
230
Incubation
condition
Aerobic
«
«
n
Anaerobic
»
9>
)»
«
»
Initial BaP
(Mg/kg)
127
49
88
trace
58
trace
trace
nil
nil
nil
BaP, j/g/kg
after 15 days
4.0
nil
0.3
nil
8000
120
160
180
210
1200
Table 7: Quantities of PAH Synthesized per Kilogram of Algal Biomass Formed From
Normal Acetate and C14 - tagged Acetate (from Borneff et al. 1°>1!)
PAH
3,4-Benzpyrene (BaP)
1 1 ,1 2-Benzfluorenthene
1 ,2,3-Indenopyrene
Benzo (ghi)perylene
3 ,4-Benzofluoranthene
1 ,2-Benzanthracene
Fluoranthene
Normal Acetate
0.7 Aig
1.4 "
1.8 "
2.2 "
3.9 "
7.8 "
58.0 "
C*4 tagged acetate
0.8 //g
1.5 "
1.7 "
2.3 "
4.2 "
6.5 "
62.0 "
Table 8: Degradation of 3,4-Benzpyrene (BaP) by Bacteria in Nutrient
Medium Incubated at 28°C (from Poglazova et al. 80)
Culture or strain
Mycobacterium lacticola 63
" DS
Mycobacterium flavum R^b
" Cj
Mycobacterium rubrum 843
" D2
Mycobacterium smegmatis
Bacillus megaterium mutant
PBK No. 5
PBKNo. 13
2/P
BaP in medium, /zg/leter
Initially After 4 days
280
280
280
280
280
280
280
280
200
200
200
188
237
200
145
241
128
180
170
160
166
190
Per cent
decrease
33
15
29
48
14
54
35
15
20
17
5
-------
448
PHYSICAL REMOVAL
Bacteria isolated from soil containing appreciable
quantities of BaP were found by Poglazova et ai°0 to be
much more active in degrading BaP than the same or similar
bacteria which had been cultivated for considerable time in
the absence of BaP or related PAH. This is true of many
kinds of hydrocarbon-oxidizing bacteria.105,106
SUMMARY
Various kinds of carcinogenic hydrocarbons (CHC),
including 3,4-benzpyrene and some 1,2-benzanthracenes,
have been found in coastal bottom deposits, plankton, and
marine animals. Suspected sources of such CHC in the sea
include the aerial transport of combustion products,
terrestrial drainage, synthesis of CHC by bacteria or higher
plants, and pollution by oil or other materials.
The CHC content of most samples of marine mud,
plankton, and animals is less than 0.1 jug/kg (dry weight),
but more than 1,000 jug/kg has been found in a few
specimens. Based on data obtained from the analysis of
only a few samples, the CHC content of crude oils appears
to range from less than 100 to more than 1,000 #g/kg.
Combustion or pryolysis of mineral oils, coal, and all kinds
of organic materials tends to generate appreciable quantities
of CHC. Air in industrialized regions has been shown to
contain from 0.2 to 54 j*g 3,4-benzpyrene (BaP) per m3.
Smoke from the 2,500 billion cigarettes consumed annually
on a worldwide basis is calculated to account for as much
BaP as the amount in 25,000 tons of crude oil, assuming
the average BaP content of the latter to be 1,000 //g/kg.
The BaP content of forest and garden soils has been
found to be from nil to 1,000 Mg/kg (dry weight). Much
higher concentrations of BaP have been reported in soil in
regions of intensive combustion exhausts. Suspended solids
filtered from river and lake water in highly industrialized
regions have been found to contain from 10 to 8,000 jig
BaP/kg. This is equivalent to 25 to 214 ug BaP/m3 water.
The average BaP content of certain unrefined vegetable
oils ranges from 1.2 to 43.7 jug/kg, coconut oil having the
highest content. Appreciable amounts of BaP and other
CHC have also been detected in various species of bacteria,
algae, and higher plants. In many cases it is problematical
whether the CHC content is attributable to pollution or to
biosynthesis.
Evidence is presented for the synthesis .of BaP by
certain bacteria, algae, and higher plants.
The biodegradation of various CHC by bacteria is well
documented. Key references are also given to the
voluminous literature on the metabolism of CHC by mice,
rats, rabbits, dogs, and invertebrates.
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CLEANING AND REHABILITATION
OF OILED SEABIRDS
Goran Odham
Goteborg University
Sweden
Release of oil from tankers is a constant threat to
seabirds, especially along seaboards or in inland seas. The
problem has recently been accentuated in the Baltic where
the sea traffic includes tankers of more than 100,000 tons.
A collision here could exterminate certain species of
seabirds, and could affect other animals as well as marine
vegetation.
The ability of the seabirds to spend a large part of their
lives on water is due to their water-proof plumage. The
water-repellant property of the plumage depends on the
textures of the feathers and the presence of a water-proof-
ing wax that is produced by the preen gland at the bird's
rear.
Experience gained from the study of oil seabirds has
shown that oil impairs two important qualities of the
plumage: water repellency and heat insulation. After oiling,
the bird's ability to fly decreases or is totally lost, and
because water repellency of the plumage is lost, feeding
becomes more difficult. The risk of poisoning by toxic
sulphur compounds in the oil is also very real. Post
mortems have shown that oil is frequently present in the
digestive tract, presumably as a result of preening. Oil
poisoning changes the natural bacterial flora, and is often
followed by fungal infections of the intestinal organs.
When detergents are used to wash oiled seabirds the
natural feather wax is removed as the solubility and
emulsifying properties and the feather wax of the contami-
nating oil are almost identical. Due to the importance of
wax in maintaining water repellency and heat insulation no
seabiid can be returned to its natural environment until the
wax has been replaced in one way or another.
Investigations of the chemical composition of the wax
have been in progress at the Institute of Medical Biochemis-
try at the University of Goteborg for several years. The wax
producing gland is a paired organ at the rump of the bird.
The gland forms a small protuberance around the two
excretory openings. Around them are arranged two small
downy tufts which in the living bird are soaked with feather
wax. The secretion of the preen gland resembles that of the
sebacious glands in being of destructive type, i.e., the whole
cells of the glandular epithelium are successively trans-
formed into secretion.
Preen gland wax of about fifteen species of seabirds
belonging mainly to the family of Anatidae has been
investigated so far. The amount of secretion that could be
continuously collected from a bird varied from a few mg up
to 200 mg every second day. Chemically, the wax consists
of monoesters composed of longchain fatty alcohols and
fatty acids. The acids and alcohols often possess methyl
branches on the carbon chains. Interestingly, different
species produce secretions of differing chemical composi-
tion; the wax is utterly species-specific [cf. e.g. 1 ].
As an example the chemical composition of the feather
wax of the common eider (Somateria mollissima) is shown
in Tables 1 and 2.2 Clearly, a very complex pattern of acids
and alcohols is at hand. If all combinations between acids
and alcohols exist the number of different wax molecule
structures exceeds 300.
An even more complicated pattern of wax molecules is
found in the preen gland secretion of the guillemot (Una
aalge), a species which has been investigated at the request
of the Imperial Chemical Industries following the grounding
of the Torrey Canyon. Here, capillary gas chromatography
showed the presence of more than 100 fatty acid structures
(Figure 1) and about the same number of alcohols. Thus
the number of possible different wax structures exceeds
10,000.
453
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454 PHYSICAL-BIOLOGICAL EFFECTS
Figure 1. Gas Chromatogram of Methyl Esters of Fatly Acids from the Qufflemot. Golay Type R Capillary Column at 168°. Inset: Expanded
Region of the Methyl Esters from n-Cg to n-C,2 at 160°.
As mentioned, the preen gland produces on an average
about 50 mg of wax per day, which compensates for the
natural loss, and the plumage usually contains a few grams
of preen gland wax. It is obvious that it takes a very long
time for the bird to replace all the wax after cleaning. The
species specificity and the very complex nature of the wax,
as exemplified above, makes it essential to use a more
simple composition, a unit wax, for replacement purposes.
In connection with an accidental release of oil in the
harbor of Goteborg attempts were made to clean 150 oiled
swans with an emulsion of triolein in water. Synthetic "unit
wax" (Pur-Cellin oil, Dragoco, Holtzminden, Germany) was
subsequently sprayed on the plumage. In practice the
spraying technique was not very satisfactory; overdoses
were given resulting in a plumage with the same properties
as the original oiled plumage.
To overcome this problem a new cleaning agent,
Larodan 121, with which the waxing takes place during
cleaning (a method similar to that sometimes used in
cleaning cars) was formulated3. The cleaning agent consists
of a crystalline dispersion of hydrophilic lipid crystals in
water with the unit wax mentioned embedded in the crystal
matrix. The formation of the lipid crystal dispersion and its
structure and properties will be described here.
In connection with a study of the phase behavior of
aqueous glyceride systems and the structure of the various
liquid-crystalline and micellar phases, a new structure of
general type was described4 -. It is formed in the water-rich
part of the phase diagram (in the region about 50-100
weight per cent water) at a certain range of the hydro-
philic-lipophilic balance (H.L.B.). The lipid in question
must thus be hydrophilic enough to interact with water,
but lipophilic enough not to give a micellar solution. If for
example a-hydroxy fatty acids in excess of water are
considered, they give a micellar solution at short chain
lengths and no interaction with water at very long chains,
whereas the actual liquid-crystalline structure is formed at
medium chain lengths (e.g. C12). The structure of this
phase is concentric with bimolecular lipid layers alternating
with water layers. These particles dispersed in the water
medium are either spherical or cylindrical in shape. The
lipid layers separated by water layers expose the polar
groups toward the water, and the hydrocarbon chains are in
a liquid state.
The particles exhibit strong birefringence when observed
in the polarizing microscope as shown in Figure 2. The
same structure has earlier been observed in diluted water
dispersions of lecithins using electron microscopy.
Lipid molecules of long-chain type crystallize in thin
sheets parallel to the bimolecular layers, as indicated in
Figure 3. When this type of lipid is crystallized from the
melt or from nonpolar solvents in which they are soluble,
the dominating crystal surface is formed by the terminating
methyl groups of the hydrocarbon chains. This gives the
-------
OILED SEABIRDS 455
Figure 2. A Liquid-Crystalline Monoglyceride-Water Dispersion
Viewed in the Polarizing Microscope. The Structure Consists Mainly
of Concentric Cylindrical Threads.
crystals hydrophobia properties (cf. Figure 3). If, however,
the lipid crystals are formed in the liquid-crystalline
medium described earlier, the crystals appear to grow by
discrete layer units corresponding to the bimolecular layers
constituting the concentric particles. The crystallization
mechanique is illustrated in Figure 4. The polar end groups
will thus be exposed on the dominating surface, which
results in hydrophilic properties of the crystals. As a
consequence of the hydrophilic properties it is possible to
muuuuwuuuum
tmnmmmmmi
muuwwm
uuuuuwuuuuuutu
mmmmmmmmm
Figure 3. Fragment of a Lipid Crystal (each molecule is indicated by
the chain axis and the polar group only). Illustrating the Dominating
Surface Formed by the Methyl End Groups.
Figure 4. Schematic Illustration of the Proposed Crystallization
Mechanism from a Liquid-Crystalline Dispersion, at which the
Dominating Crystal Surfaces are Formed by the Polar Groups.
obtain a dispersion of such crystals in as much as 90 weight
per cent water with a firm consistency. One application of
hydrophilic lipid crystals is their use as an ointmentbase.5
The formulated cleaning agent for oiled seabirds consists
of a dispersion of hydrophilic monolaurin cyrstals in water,
and as the unit wax is present during the crystallization the
wax first forms microdroplets in the central part of the
liquid-crystalline particles. The wax droplets seem to
remain unchanged after the crystallization, the difference
being that they afterwards are surrounded by crystalline
monoglycerides instead of the flexible liquid-crystalline
lamellae. The hydrophilic monoglyceride crystal dispersion
has a good emulgating capability of oil. The crystals can
easily be split mechanically along the methyl end group
planes. The emulgating properties are probably due to such
separation of the layers constituting the crystals, at which
hydrophobic surfaces are formed. The idea behind the
formulation is that the wax microdroplets are located in the
central part of the crystalline particles, and at cleaning the
layers will separate.
In Larodan, the hydrophilic lipid is the 1-monoglyceride
of dodecanoic acid (chain length 12) and the synthetic wax
(Pur-Cellin oil) contains a methyl-branched C7 -acid linked
to rt-octadecanol-1. The wax is a common component of
cosmetic preparations (Larodan 127 refers to these chain-
lengths). The proportions of the three components, mono-
glyceride, wax and water, were adjusted on the basis of
practical tests so that the final product consisted of 20%
monoglyceride and 29c wax in water. The cleaning agent
thus consists of two lipid components of the same type as
those occurring naturally in seabirds.
The cleaning agent was tested in the laboratory on ten
Peiping ducks contaminated with Shell talpa oil 30 to
which carbon powder had been added. About 100 g of
contaminant was used on each bird, and after 3 days they
were washed with the cleaning agent. Only one washing was
required to remove the oil, and after 8-10 days the birds
could swim. Comparisons with other cleaning agents
-------
456 PHYSICAL-BIOLOGICAL EFFECTS
showed that with these the washing procedure was longer,
and the birds took longer to float.
Larodan has been used on a large scale in Scandinavia,
for example in Gavle, Sweden, where about seventy-five
birds belonging to the family of Anatidae were successfully
cleaned and returned to their natural environment within a
fortnight.
Table 1: Acids Found in the Preen Gland Wax ofSomateria
moltissima.
Table 2: Alcohols Found in the Preen Gland Wax of
Somateria molKsama.
Structure
Relative abundance
2,6-Dimethyloctanoic acid 18.2
2D,4D,6D-Trimethyloctanoic acid 12.6
4.6-Dimethyloctanoic acid 4.9
2,4-Dimethylnonanoic acid 1.3
2D,4D,6D-Trimethyhionanoic acid 27.0
2,6-Dimethyldecanoic acid 7.8
2,8-Dimethyldecanoic acid 2.7
2D,4D,6D,8D-Tetramethyldecanoic acid 2.1
2,6,8-Trimethyldecanoic acid 8.6
2,6-Dimethylundecanoic acid 3.1
2D,4D,6D,8D-Tetramethylundecanoic acid 1.5
Unidentified material 5.9
n-Hexanoic acid 0.1
n-Heptanoic acid 0.1
n-Octanoic acid 1.4
R-Nananoic acid 0.2
R-Decanoic acid 2.1
R-Undecanoic acid 0.1
R-Dodecanoic acid 0.3
100.0
Structure
Straight chain alcohols
n-Tetradecanol-1
n-Pentadecanol-1
n-Hexadecanol-1
n-Heptadecanol-1
H-Octadecanol-1
Branched alcohols
Branched C
Branched C
Branched C
Branched C
15
17
17
19
Relative abundance
0.9
0.5
28.1
1.7
63.7
94.9
0.3
2.1
1.6
S.I
100.0
REFERENCES
1. Odham, G., and Stenhagen, E., Ace. Chem. Res. 1971
In press.
2. Odham, G., Arkiv Kemi 27,263 (1961)
3. Larsson, K., and Odham, G., Marine Poll. Bull. 1,122
(1970)
4. Larsson, K., Z. phys. Chem. 56,173 (1967)
5. Larsson, K., English Patent No. 1174672 (1970)
-------
INITIAL AGING OF FUEL OIL FILMS
OF SEA WATER
Craig L. Smith and William G. Maclntyre
Virginia Institute of Marine Science
ABSTRACT
The process of aging or weathering of nos. 2, 4, and 6
fuel oil films on sea water has been studied both in
laboratory apparatus and at sea. Loss of oil components by
evaporation and dissolution was considered to be the main
mechanism of the initial weathering. The rates of evapora-
tion of each oil type and comparison of the relative
importance of evaporation and dissolution are reported.
During the initial weathering period, the rate of evaporative
loss of weight of a given fuel oil was found to be
proportional to the percentage of volatile compounds (ie.
with boiling points less than 27
-------
458 PHYSICAL-BIOLOGICAL EFFECTS
EXHAUST
DRY ICE, ACETONE
Figure 1: Bubbler assembly foi oil film aging.
permitted removal of sea water for analyses, avoiding
contamination by the film.
The cold trap contents, as well as the sea water aliquots
were extracted with several portions of pentane, and the
extracts adjusted to a standard volume for gas chromato-
graphic analysis. A Perkin-Elmer Model 900 gas chroma-
tograph with flame ionization detectors was fitted with
dual %" x 3' copper columns packed with 5% SE-30 on
80/100 mesh acid washed and sflanized Chromosorb W. The
temperature was programmed at the rate of 8° per minute
from SO-300°C. These conditions and choice of column
were selected to provide the low resolution requirements of
the ASTM Boiling Range Test by Gas Chromatography
(D2887-70T). The chromatograms obtained, therefore, do
not show the detail possible from normal operation. The
chromatograms were quantified by comparison of peak
areas with those of hydrocarbon reference standards.
A spill of 200 gallons of no. 2 fuel oil 15 miles off the
Virginia coast was sampled hourly from the time of release
until effective dissipation. Samples were scooped from the
film and stored in foil-lined Mason jars at Dry Ice
temperatures until analysis. The air and water temperatures
during this study were almost constant, at about 5°C. The
wind and sea state at the time of release were very calm,
but increased to 18-20 knots with whitecaps and breaking
waves. After 8 hours, the film could no longer be
effectively sampled. Gas chromatograms of the raw oil
itself, or of a pentane extract were made for each sample.
The fuel oils used in this study had various origins and
somewhat vague histories. The no. 2 oil was a straight run
distillate derived from various Texas crudes, and had a
boiling range of 170-370"C. Its composition is defined
Table 1. About half of this grade is in the volatile portion
with boiling point less than 270°C. The nos. 4 and 6 fuel
oils were derived from Venezuelan crudes, and were
characterized by their supplier as mixtures of pure residual
oil with various refinery distillates, blended to an appro-
priate viscosity. Both these oils had initial boiling points
around 170°C, and actual distillation showed no major
discontinuities in boiling point composition. The aromatic
character of the oils was determined by the ASTM
Table 1: Fuel Oil Composition
Boiling Range (at 760mm)
Fuel
oa
#2
#4
#6
Below
200°C
200-
270° C
45%
Above
270°C
50%
85%
90%
Aromatic
Character
42%
45%
29%
each, corresponding approximately to the 170-270° C boil-
ing range.
Results
The rates of loss of volatiles from each grade of fuel oil
are compared graphically in Figure 2. The plots of all three
oils show the common feature of a high initial rate of loss
during the first ten hours, which tapers off to a nearly
linear slope. How long this linear portion of the loss curves
will be found has not been determined, but it must
eventually flatten out as the reserve of volatiles in the oil
film is depleted. The change in boiling range composition
14-
hi
oc
o
£L
<
hi
U.
O
z
hi
O
cc.
hi
Q.
12-
10-
I
10
20
TIME (hours)
Figure 2: Rates of fuel oil evaporation in bubbler apparatus,
25'C., 2 liters/minute flow.
-------
AGING OF FUEL OIL FILMS 459
with time of the trapped evaporate fractions of nos. 2, 4,
and 6 fuel oils is shown in Figure 3. The bottom and top
curves represent the initial and final boiling points of the
fraction, and the middle curve defines the mean boiling
point of the fraction. The results from each of the three oils
were sufficiently similar to permit the use of only one curve
for each of the three oils. Differences of any significance
were noted only in the first six hours. A broken portion of
each curve in that region demonstrates the general trend of
the three oils only. The boiling ranges were determined by
the ASTM Boiling Range Test by Gas Chromatography.
Note that the initial and mean boiling point curves assume a
linear slope, while the final boiling point curve flattens out
« 300°.
o
o
a.
o
z
J 200°-
o
-------
460 PHYSICAL-BIOLOGICAL EFFECTS
The amount of oil components found dissolved in the
sea water was found to be almost negligible when compared
to the amount evaporated for all three oils. There are prob-
ably several reasons for this result, but the limit of solubili-
ty does not appear to be a critical factor. Naphthalene, for
example, was found in concentrations some two orders of
magnitude smaller than its maximum calculated solubility.
It also appears from comparisons of gas chromatograms of
the oil before and after the weathering experiment that the
reserves of the possible water soluble components of the oil
film have not been exhausted. An experiment designed to
prove this is planned. The most likely explanation is that
dissolution of the water solubles is in direct competition
with evaporation. This is borne out by the finding of
considerable quantities of aromatics in the evaporate
fractions, including those compounds which were identified
in the water extracts. These compounds may either be
evaporated directly from the oil film, or they may be
efficiently scrubbed from the sea water by the air sweep
which was continuously bubbled through it. A recent paper •
on the subject1 shows that even aromatic hydrocarbons are
fairly readily partitioned into the gas phase from an
aqueous solution.
The gas chromatogram of the sea water extract from the
weathering experiment with no. 4 fuel oil is compared with
the gas chromatogram of a low boiling distillate fraction of
no. 4 fuel oil in Figure 5. The aromatic portion of the
#4 fuel oil
aromatic fraction
#4 fuel oil
aqueous extract
200° C 240* C 280° C
SIMULATED BOILING POINT (ASTM D2887-70T)
Figure 5: Comparison of no. 4 fuel oil aromatic fraction, bp.
190-25CTC with no. 4 fuel on water solubles.
distillate fraction, separated by column chromatography on
silica gel, is shown to be quite similar. The saturated
portion of the distillate fraction was entirely different in
character. The most interesting feature of the sea water
extract is the low concentration of the low boiling
alkylbenzenes, which are thought to be quite soluble in
water. This again, may be a result of scrubbing by the air
sweep. The relatively large amounts of these compounds
which were found dissolved in sea water after equilibration
with petroleum products in a recent report2 may be due to
the fact that the authors permitted no equilibration of their
system with the atmosphere. In most natural environmental
situations, an oil film and the first few feet of water
beneath it are in good contact with the atmosphere due to
wave action. Therefore, the lower molecular weight alkyl-
benzenes from an unconfined oil spill should be released to
the atmosphere for the most part, and would not be
dissolved. The majority of the components of a fuel oil spill
which do dissolve, then, will be the less soluble but far less
volatile high boiling aromatics.
The assignment of the peaks in these chromatograms was
made on the basis of identical retention time with an
authentic sample where possible, or by the mass spectrum
of the fraction trapped from the gas chromatograph
effluent. A more detailed study of the scrubbing pheno-
menon is planned when the gas chromatograph is set up for
higher resolution.
The study of the behaviour of an oil film at sea is limited
to the periodic sampling of the film itself, mainly because
of the high dilution factors involved for the evaporated and
dissolved components. Figure 6 shows the rates of loss of
several representative normal paraffins from an unconfined
spill of no. 2 fuel oil at sea. The rates of loss of these
WIND SPEED (knots)
I 10 15 18 18
100-
0 I 234567
TIME (hours)
Figure 6: Rate of loss of /t-paraffins from no. 2 fuel oil slick at sea.
5*C.
-------
AGING OF FUEL OIL FILMS 461
paraffins show a regular decrease as the carbon chain, and
boiling point increase. The rather sharp break observable in
the curves after about three hours is due to a major increase
in wind strength. The wind, which was of negligible
intensity at first, increased to a velocity of about 18 knots.
The break in the curves corresponds to the onset of
whitecapping and breaking waves. Such wave action in-
creases the surface area of the film and at the same time,
decreases film thickness. At sea, as well as in the laboratory
bubbler experiment, the rate of loss of compounds with
boiling points higher than 270° is quite small. Table 3
compares the percentages of normal paraffins lost from
films of no. 2 fuel oil at sea after about 6 hours with those
lost from no. 2 oil films in the laboratory bubbler after 40
hours. Despite the fact that the weathering in the bubbler
apparatus was carried out at 20°C higher temperature and
for 7 times longer, losses from the film at sea were much
larger. Rough calculations show that the bubbler experi-
ment would have to have been continued in excess of 100
hours to achieve comparable weathering. This result is
believed to be due to the fact that at sea, air flow across the
film surface was several orders of magnitude greater than
that in the laboratory, when the wind velocity and total
surface area per unit volume of oil was considered.
It was initially planned to study laboratory weathering
where the air sweep was just passed over the oil film,
instead of being bubbled through. Preliminary experiments
showed that this resulted in a slower rate of evaporation of
volatiles. Because the evaporation rate at sea so greatly
exceeded that with bubbling, weathering in the laboratory
in this non-turbulent mode should have even less relevance
to the processes in actual oil spills. Future experiments are
to be carried but at increased rates of weathering.
In summary, we find that the major pathway of initial
weathering of fuel ofls is evaporative loss of volatile
components. The volatile components are those with a
boiling point less than 270° C. The initial rates of loss of
Table 3: Loss of n-Paraffins from #2 Fuel OU
Percent of initial concentration lost
Normal After 6 hrs. at sea, After 40 hrs. in
Paraffin 18 kn. wind, 5°C bubbler, 2S°C
Decane
Hendecane
Dodecane
Tridecane
Tetradecane
Pentadecane
96.
85.-
58.-
44.:
7.1
5.'
80.7%
45.8%
19.7%
5.5%
none
none
these volatiles are proportional to the amount of volatile
material present. The oil viscosity doesn't seem to be an
important factor. Large accelerations of weathering rates
occur when wind strength increases to the onset of
whitecaps and breaking waves. Even the relatively water-
soluble low boiling alkylbenzenes are readily evaporated,
leaving the less soluble higher boiling aromatics as the
major dissolved species.
ACKNOWLEDGEMENTS
We would like to thank the Federal Water Quality
Administration for financial support of this study, NASA
Wallops Island for vessel support, and NASA Langely
Research Center for use of their mass spectrometer.
REFERENCES
1) C. McAuliffe, Chen Tech., Jan. 1971, p. 46.
2) D. B. Boylan and B. W. Tripp, Nature, 230,
44(1971).
-------
PHYSICAL PROCESSES IN THE SPREAD OF
OIL ON A WATER SURFACE
James A. Fay
Fluid Mechanics Laboratory
Department of Mechanical Engineering
Massachusetts Institute of Technology
Cambridge, Massachusetts
ABSTRACT
Formulae are recommended for calculating the extent
of the spread of oil slicks on water as a function of time.
They are based on empirical measurements of spreading
rates and analytical and theoretical studies of the physical
processes which accelerate or retard the spread of a film.
Both one-dimensional and two-dimensional (axisymmetric)
slicks are treated. Comparisons of the recommended formu-
lae are made with the limited number of field observations,
both for the rate of spread and the maximum slick size.
INTRODUCTION
This paper reviews our current understanding of the
physical processes which initially cause and ultimately ter-
minate the spread of oil (or other immiscible fluids) on the
surface of water. We are principally concerned with the
spread of large volumes of oil, such as might be encount-
ered in spills from ships or oil wells, and which cannot be
reproduced easily in a laboratory at full scale. Our approach
is to consider some simple cases of oil spread, which will
not likely be duplicated precisely in practice, but for which
a theoretical or semi-empirical description can be found,
especially through use of properly designed laboratory exp-
eriments which simulate full scale spreading phenomena.
Based on this understanding, a correlation of field observ-
ations is made as a test of the suitability and accuracy of
these predictions, and empirical formulae for estimating
spreading rates are recommended.
The physically most important assumption underlying
our analysis, which is most likely to be violated in any real
incident of a spill, is the absence of any effects of wind,
tidal currents and waves. We would expect that the drifting
motion caused by winds and tidal currents would simply be
superimposed on the spreading motion to be experienced
on calm, stationary water, since these latter motions are
confined to a layer near the surface which is relatively thin
compared with that subject to wind friction effects or tidal
motion. It is more likely that wind and tidal current will
produce relative shearing motion in the plane of the water
surface, deforming the shape of the spreading slick from
those simple shapes expected in calm water. Such distortion
is commonly observed, and is most likely to limit the useful-
ness of the spreading laws which we propose. These effects
are very difficult to predict or even describe, and there is
little empirical evidence on which to base an estimate of
their importance.
The first order effects of surface waves, on the other
hand, can be shown to be negligible. Because of their per-
iodic nature, waves produce oscillatory forces having zero
mean value and which therefore do not affect the spreading
motion which proceeds on a much longer time scale than
the usual wave periods. Of course, there are non-linear
effects of waves which are probably not separately disting-
uishable from those associated with winds and tidal
currents, and are equally difficult to predict.
The use of laboratory scale experiments to establish
empirical spreading laws and to check theoretical predic-
tions has been discussed elsewhere!. We shall make use of
such experimental evidence to provide the best estimate of
spreading rates, accepting the asserted validity of the scaling
of these experiments to full size. The basis of such scaling is
a well understood aspect of fluid mechanics, and will not be
further discussed here.
*This research was supported by the U.S. Coast Guard under
contract No. DOT-CG-01-381-A.
463
-------
464 PHYSICAL-BIOLOGICAL EFFECTS
Accurate field observations of the spread of oil slicks
are very rare. We have tried to include all measurements
which have been published, but in most cases we have been
forced to assume additional information, such as spreading
coefficients, when comparing these observations with a
theory. Given the inaccuracy of the observations, these
assumptions are of no great significance, but only serve to
emphasize the scarcity and crudity of the observations. A
major goal of our proposed correlations is to permit the
comparison with future (and hopefully more accurate)
observations.
Spreading and Retarding Forces
Although the force of gravity acts downward, it causes
a sidewise spreading motion of a floating oil film by creat-
ing an unbalanced pressure distribution in the pool of oil
and the surrounding water. This force on an element of oil
film acts in the direction of decreasing film thickness and is
proportional to the thickness, its gradient, and the differ-
ence in density between oil and water. (See Fig. 1.) As the
oil film spreads and becomes thinner, the gravity force
diminishes.
At the front edge of the expanding slick an imbalance
exists between the surface tension at the water-air interface
and the sum of surface tensions at the oil-air and oil-water
interfaces. Hie net difference, called the spreading coeffic-
ient, is a force which acts at the edge of the film, pulling it
outwards. This spreading force does not depend upon the
film thickness as does the gravity force, and will not de-
crease as the oil film thins out (unless the chemical proper-
ties change through aging). Eventually the surface tension
force will predominate as the spreading force.
These spreading forces are counterbalanced by the
inertia of the oil film and of the thin boundary layer of
water below it which is dragged along by friction (see Fig.
1). The inertia of an element of the oil layer decreasess with
its thickness as time progresses and the film spreads, but the
inertia of the viscous layer of water below the oil increases
with time as its thickness grows. Consequently, the viscous
retardation will eventually outweigh the inertial resistance
.of the oil layer itself.
GRAVITY
INERTIA
SURFACE TENSION
&-J7T
T
FRICTION
Fig. 1: , The four forces which act on an oil film
(see list of symbol!).
It is also informative to consider these effects from the
point of an energy balance. A pool of oil floating on water
possesses a greater potential evergy than the water it dis-
places, in proportion to its thickness. As it spreads and its
thickness decreases, there is a loss of potential energy. Also,
as air/water surface is replaced by an oil film, the surface
energy per unit area (which has the same physical value as
the interfacial tension) is reduced by an amount equal to
the spreading coefficient. Thus both surface energy and
potential energy are decreased as the slick spreads. This
energy is converted either into heat by viscous dissipation
in the water beneath the slick or into the energy of gravity
surface waves which propagate away from the expanding oil
pool. In other words, each spreading force is associated
with an energy-producing process and each retarding force
with an energy-dissipating process.
It is thus clear that the spread of an oil film will pass
through several stages as time progresses, in each of which
one spreading force will be balanced by one retarding
force.2 Although there are four such possible combinations,
for large scale slicks only three regimes are important: (i)
the gravity-inertia regime (called "inertial spread"), (ii) the
gravity-viscous regime (called "viscous spread") and the sur-
face tension-viscous regime (called "surface tension
spread"). As time progresses, a large spill will pass through
these three regimes in succession. A very small spill (a few
liters, say) will almost from the start behave as a surface
tension spread.
The spreading laws for each regime have been deter-
mined, to within an unknown constant, for each regime and
for the. cases of a one-dimensional and two-dimensional
(axisymmetric) slick1.2. These laws give the linear extent
of the slick (length C or radius r) as a function of the time t
since the oil was released at the origin of the spread, the
volume of the oil spill and the physical properties of the oil
and water. These spreading laws are given in Table I, and
the undetermined proportionality coefficients are denoted
by the symbol k.
Evaluation of Spreading Laws
The proportionality constants k can be determined
from laboratory experiments or from a suitable detailed
hydrodynamic theory of the spreading motion in each re-
gime. So far, only one-dimensional spreading experiments
have been reported1-3, and there have been advanced con-
flicting theories1-4 for the inertial spreading regime. We
suggest below (and in Table II) best values for these coeffi-
cients, based upon published experimental data and our
own (unpublished) theoretical analysis and extrapolation of
the empirical data. We discuss below each entry separately.
One-dimensional inertial spread. Here we use the
experimental value of to; = 1.5 determined by Hoult and
Suchon1 (see Fig. 2). Their theoretical value (kjj = 3) is
clearly in disagreement with the experiments. An alter-
native theoretical solution has been given by Fannelop and
Waldmant, from which kfo is found to be 3/101/3 = 1.39.
We believe that the correct theoretical value is 3/71/3 =
-------
PHYSICAL PROCESSES ... 465
1.57, for reasons which we shall not elaborate on here. This
latter theoretical estimate is certainly very close to the
observed values in the laboratory experiments.
One-dimensional viscous spread. The empirical value of
lqv = 1.5 determined by Hoult and Suchon1 (see Fig. 2) is
recommended.
io2
S 10'
10
-M.5(AgAt2)"3
J I
I0"z 10"' I 10'
t/[A4/(Ag)iV]l/7
10'
I0a
Fig. 2: Experiments showing the transition from inertial
to viscous spread, for a one-dimensional flow^. .
'l',o-2
10
-3
o DODECANOL -I
D OLEYL ALCOHOL
A COTTONSEED OIL
+ TRICRESYL PHOSPHATE
2,3 M/4
10*
10'
10°
One-dimensional surface tension spread. The
experiments of Garret and Barger5 (see Fig. 3) and Lee3
(see Fig. 4) both support a value of kit =1-33.
Two-dimensional (axisymmetric) inertial spread. Since
there are no experimental results available, we recommend
the theoretical value of k2i = 2/ (37r)l/4 = 1.14 as determ-
ined by the same analysis leading to the one-dimensional
value quoted above, and which agreed closely with the cor-
responding experiments. This value is also given by
Fannelop and Waldman-4
Two-dimensional viscous spread. Again, no experi-
ments have been reported. A boundary layer theory de-
veloped by Hoult and Suchon1 possesses no unique solu-
tions and hence yields no definite values for kiv or k2v- It is
our belief that the proper solution can only be determined
theoretically by solving the complicated flow at the leading
edge of the slick. However, we suggest that an estimate of
k2y can be made in the following manner. If we select the
one-dimensional theoretical solution which leads to the
observed value of kiv, and then hypothesize that the two
dimensional solution should have the same boundary
values, we can then determine the value of k2v from this
latter solution. Our justification for such a procedure is the
supposition that the flow near the leading edge of the slick
is the same for the two-dimensional as for the one-
dimensional case, and that the dimensionless boundary
values of the theoretical solutions, which are determined by
this flow, should also be identical. Using this procedure, we
have found the value shown in Table II.
Two-dimensional surface tension spread. We have used
the same piocedure as that outlined in the preceding
paragraph to estimate the value of k2t, shown in Table II,
Fig. 3: Measurements of spreading velocity versus slick
length for one-dimensional surface tension spreading
Q experiments.^
10
107f
4x106
10
,7
6x10'
Fig. 4: Lee's experiments^ on one-dimensional surface
tension spreading. Solid line corresponds to k^ = 1.33.
-------
466 PHYSICAL-BIOLOGICAL EFFECTS
since there are no experiments available. According to
Fay2, the maximum observed spread in field observations
would correspond to k2t = 10//F = 5.7. While this is larger
than the corresponding value recommended in Table II, it is
most likely uncertain by a factor of two because of the
difficulties of making observations and the imperfections of
the field experiments. A comparison of the theoretical
spread area with observed values is shown in Fig. 5.
.to
10'
I0e
10'
10
I I
2 xlO* TONS OIL (TORREY CANYON)
80 BBL OIL
3O BBL OIL
o
— o
110
9O
25
BBL
BBL
BBL
SANTA BARBARA
OIL/WATER
OIL/WATER
OIL/WATER
I03
10"
10°
t (sec)
10"
Fig. 5:
A comparison of the theoretical axisymmetric slick area (for surface
tension spread) with observed values2.6. Solid line corresponds to
the value of k2t shown in Table II and a spreading coefficient of 30
dyne/cm.
The Termination of Spreading
It has already been noted that, after some time, slicks
cease to spread2'7. In almost all cases, the final film thick-
ness is much greater than that of a monomolecular layer7,
being about Ifr2 to 10~3 cm. Fay2 has suggested that the
cessation of spread is caused by the evaporation of some oil
fractions which reduces, the spreading coefficient to zero.
His estimate of slick size for which this evaporation (limited
by diffusion through the oil layer) would be appreciable,
was an order of magnitude smaller than the observed values.
We propose here a modified version of this theory. We
believe that the spreading coefficient is reduced by an in-
crease in the wafer-oil interfacial tension brought about by
the dissolving of oil fractions in the water layer underneath
ttie oil film. The volume of oil which can be dissolved in
this layer (per unit area of oil/water interface) would then
be s(Dt)l/2\ where s is the solubility of the significant oil
fractions in water. As a consequence, the previous estimate
of Fay would be increased by a factor of s-3/8, or a factor
of about ten for s = 10-3, a reasonable value. As a conse-
quence, the maximum area A of the slick would become,
A „
1/8
10
8
UJ
cc
o
o
1
1
1
0246
LOG VOLUME (m3)
Fig 6:
Maximum slick area as a function of volume. Eq. (2) compared with
observations taken from Ref. 7.
in which ka is an undetermined constant of order unity.
Because of the uncertainties in s and a in the field
observations, and the lack of laboratory data, it is proposed
that the maximum slick area be related to the volume of
the spill by the dimensional formula,
A(m2)=!05 [V(m3)]3/4 (2)
This is compared in Fig. 6 with field observations recently
summarized by Allen and Estes7. Equation (1) would have
the value given by Eq. (2) if o = 10 dyne/cm, D = 10-5
cm2/sec, s = 10-3, and ka = 1.
NOMENCLATURE
A Volume of oil per unit length normal to x
g Acceleration of gravity
h Thickness of oil film
k Proportionality constant
C Length of one-dimensional oil slick
r Maximum radius of axisymmetric oil slick
solubility
t Time since initiation of spread
u Spreading velocity of oil film
V Volume of oil in axisymmetric spread
-------
PHYSICAL PROCESSES ... 467
x Dimension in direction of one-dimensional spread
8 Thickness of viscous boundary layer in the water
underneath the oil film
a Spreading coefficient or interfacial tension (with
subscript)
v Kinematic viscosity of water
ir Absolute viscosity of water
p Density of water
A Ratio of density difference between water and oil
to density of water
Subscripts
1 One-dimensional spread
2 Two-dimensional (axisymmetric) spread
S Maximum area
i Inertial spread
t Surface tension spread
v Viscous spread
ow Oil/water
aw Air/water
oa Oil/air
Table I: Spreading Laws for Oil Slicks
One-dimensional
Inertial
Viscous
Surface tension
£ = kji (AgAt2)l/3
« = kiv (*gA2t3/2/j;1/2)l/4
£ = kit (o2t3/p2.,)l/4
Axisymmetric
r = k2i (agVt2)l/4
r = k2v(AgV2t3/2/pl/2)l/6
r = k2t(a2t3/p2J,)l/4
Table II: Spreading Law Coefficients
One-dimensional
Inertial
Viscous
Surface tension
ku = 1.5
lqv=1.5
ku = 1-33
Axisymmetric
1.14
1.45
2.30
REFERENCES
1. Hoult, D.P., and Suchon, W., 'The spread of oil in a
channel," Fluid Mechanics Laboratory, Dept. of Mechanical
Engineering, Massachusetts Institute of Technology, Cam-
bridge, May 1970.
2. Fay, J.A., "The spread of oil slicks on a calm sea,"
Oil on the Sea (ed. by D. Hoult), pp. 53-64, Plenum, New
York, 1969.
3. Lee, R.A., "A study of the surface tension con-
trolled regime of oil spread," M.S. Thesis, Massachusetts
Institute of Technology, Cambridge, Jan. 1971.
4. Fannelop, T.K., and Waldman, G.D., 'The dynamics
of oil slicks or creeping crude," Paper No. 71-14, Am. Inst.
of Aeronautics nad Astronautics, New York, Jan. 1971.
5. Garrett, W.D., and Barger, W.R., "Factors affecting
the use of monomolecular surface films to control oil pollu-
tion on water," Env. Sci. and Technology, 4, pp. 123-127,
Feb.1970.
6. Allen, A., Statement on Santa Barbara oil spill pre-
sented to U.S. Senate Interior Subcommittee on Minerals,
Materials and Fuels, May 1969.
7. Allen, A.A., and Estes, J.E., "Detection and mea-
surement of oil films," Santa Barbara Oil Symposium, U. of
California, Santa Barbara, 1970 (to be published).
-------
THE BEHAVIOR OF OIL ON WATER
DERIVED FROM AIRBORNE INFRARED
AND MICROWAVE RADIOMETRIC
MEASUREMENTS
J.M. Kennedy
TRW Systems
Houston, Texas
and
E.G. Wermund
Remote Sensing, Inc.
Houston, Texas
INTRODUCTION
The objectives of this paper are to describe some
physical properties of oil spills and to evaluate both
infrared imagery and the microwave radiometry for
tracking and calculating volumes of oil spilled.
According to 1969 estimates by the Federal Water
Quality Administration, now a member of the
Environmental Protection Agency, 7,000 oil spills occur in
United States Waters annually. This number is based on
identifiable slicks^Jhe true number may be considerably
larger. Assuming this number is relatively accurate this
relates to about 20 identifiable spills per day, a large
number if random distribution is assumed. However, a
majority of these can be related to geographic locations
where oil production, shipping, storage and pipelining are
concentrated, i.e., the Houston-Galveston area. The basic
problem is not finding a sufficient number of spills to
analyze, but is one of identifying the source,how much.and
assignment of a hazard priority. The most economical
method of geographical surveillance for spills, identifying
sources and predicting terminal locations is by utilization of
airborne detection and monitoring systems.
BACKGROUND
In 1966 a series of experiments was carried out which
showed that long wavelength systems (microwave)
penetrated fresh water ice and with proper analysis, ice
thickness could be measured. These laboratory
measurements and developed theory were extended to
include oil on sea water in 1967. The basic data is shown in
Figure I, where a bistatic microwave system was used to
show that two interface reflections occur which produce
constructive and destructive electromagnetic radiation
values. When reflection from the air/oil interface are in
phase with the reflection from the oil/water interface
constructive signals are received. When these reflections are
out of phase destructive interference occurs and the
resultant signal is reduced. These oscillations approach a
sine wave configuration that can be associated with oil
thickness on a quarter wave length basis. With this
established relationship it should be possible to determine
oil thickness on water to a fraction of a wavelength, once
refraction factors are determined. However, notice in
Figure 1 there are points of ambiguity. That is, in two
pattern wave-lengths there are four oil thickness values that
produce the same values. This problem can be overcome by
selecting instruments with the proper observational
wavelength. If the observational wavelength is too long,
differential values between open water and oil
contaminated water will be too small to detect or the
accuracy would be somewhat doubtful. If the observational
wavelength is too short the ambiguity problem is present.
According to the Melpar Report(l) (1969) surface
dispersion is very rapid and oil thickness on heavily
contaminated water does not exceed 2 mm. Therefore, if
microwave systems with operating frequencies in the order
of 20 mm are used, analysis of oil thickness is confined to
the first rise and straight line portion of the constructive
interference pattern.
469
-------
470 PHYSICAL - BIOLOGICAL EFFECTS
w
u
S
0.4S7 cm
T T t
0.914cm 1.2cm oil I.371cm
Oil Thickness in Centimeters
Figure 1: Voltage vs Oil Thickness on Sea Water (No.20 SAE Oil)
Thermal infrared imagery systems have proven to be of
great value in tracking oil spills and determining their areal
distribution. The first extensive use of systems operating in
the thermal infrared region (8 to 14 micron) occurred in
conjunction with the infamous Santa Barbara incident. At
that time there was a great deal of discussion and academic
discourse on why the oil appeared as a cool anomaly against
a warm water background. For the Santa Barbara spill,
Lowe and Hasell(2) (1969) suggest that the cold appearing
oil results from upwelling colder water mixed with oil.
Estes and GolombC3) (1970) agree that the cold signature
of oil results from cold water mixing. They suggest that hot
spots result where thick unmixed oil absorbs and re-emits
greater heat.
IR images in the 8 to 14 microns regions were
obtained from three oil spills in the Gulf of Mexico during
1970: the Main Pass Block 41 spill in March, the Chambers
and Kennedy spill off Galveston in May and the South
Timbalier Block 26 spill in December. Altitudes of infrared
scanning were from 2,000 to 35,000 feet. Times of data
collection were from 0130 to 2030 hours with sea states
varying from dead calm to 6 foot waves. Thermometric oil
temperatures varied from ambient in the storage tanks of
the Chambers and Kennedy platform, to production
temperature at the Main Pass Block 41 platform
(approximately 250°F), to oil heated by fire on the South
Timbalier Block 26 platform. In every case, the oil
appeared colder than the water except for a few very local
hot spots. In each of these cases the 8 to 14 micron
signature for oil remained cool compared to open water.
Therefore, it is unlikely that upwelling phenomenon is
involved in all cases.
Two possible explanations appear reasonable. One, the
cold signature for oil on water is related to an evaporation
phenomenon. In this case evaporation of volatile elements
from fresh oil is more rapid than from water and
evaporative cooling of the surface takes place. A difficulty
with this theory is that evaporation must persist for days.
Our data show that oil trapped for several days against
convergence lines, the brackish-marine waters interface, still
appears cold relative to sea water. A second and more
acceptable explanation is that the contrast is due to an
emissivity phenomenon. Oil heated in the fire of the South
Timbalier Block 26 platform (Figure 2) remians cooler than
uncontaminated open seawater. The primary reason is that
the emissivity of oil is less than that of seawater. This is also
compatible with the observation of small hot spots within
the oil spill area. The hot spots seem to appear where there
is emulsified foamy oil which behaves like a diffraction
grating. This results in local high emissivity and resolves the
-------
BEHAVIOR OF Oil 471
Table 1: Quantitative Determination of Oil by Multisensor Data Comparison
Fit 1
1300 Hrs.
3/11/70
Zone 1
Zone 2
Zone 3
Zone 4
Zone 5
Zone 6
Zone 7
Zone 8
Zone 9
Zone 10
Zone 11
TOTALS
Planl-
meter
area
(Sq.In.)
0.75
0.09
0.36
0.67
0.15
0.69
0.03
0.29
0.46
0.20
0.20
3.87
Conversion
Factor
43.60xl06
43.60xl06
43.60xl06
43.60xl06
43.60xl06
43.60xl06
43.60xl06
43.60xl06
43.60xl06
43.60xl06
43.60xl06
Ground Area
(Sq. Ft.)
32.70 x 106
3.92 x 106
15.69 x 106
29.21 x 106
6.54 x 106
30.08 x 106
1.30 x 106
12.64 x 106
20.05 x 106
8.72 x 106
8.72 x 106
168.73 x 106
Micro-
wave
Temp.
(°K)
260
232
226
250
226
260
226
226
260
250
235
Estimated
Thickness
(mm » Ft)
l.B * .0059
0.8 * .0026
0.6 = .0020
1.4 = .0046
0.6 = .0020
1.8 = .0059
0.6 = .0020
0.6 = .0020
1.8 = .0059
1.4 = .0046
0.8 = .0026
Cubic Feet
of Oil
19.29 x 10*
1.01 x 10*
3.12 x 104
13.43 x 104
1.30 x 104
17.74 x 104
.26 x 104
2.52 x 104
11.82 x 104
4.01 x 104
2.26 x 104
76.76 x 104
Barrels of
oil
(1 barrel »
31.5 Gal.)
4.58 x 104
.23 x 104
.74 x 104
3.19 x 104
.30 x 104 •
4.21 x 104
.06 x 104
.59 x 104
2.80 x 104
.95 x 104
.53 x 104
18.18 x 104
Table 2: Quantitative Determination of Oil by Multisensor Data Comparison
Fit *
1630 Hrs.
3/11/70
Zone 1
Zone 2
Zone 3
Zone 4
Zone 5
Zone 6
Zone 7
Zone 8
Zone 9
Zone 10
TOTALS
Plani-
meter
area
(Sq.In.)
.50
.05
.07
.26
.25
.10
.29
.325
.69
.095
2.630
Conversion
Factor
68.64xl06
68.64xl06
68.64xl06
68.64xl06
68.64xl06
68.64xl06
68.64xl06
68.64xl06
68.64xl06
68.64xl06
Ground Area
(Sq. Ft.)
34.32xl06
3.43xl06
4.80xl06
17.84xl06
17.16xl06
6.86xl06
19.90xl06
22.30xl06
47.36xl06
6.52xl06
180.49xl06
Micro-
wave
Temp.
(°K)
Not Avail
Not Avail
Not Avail
Not Avail
Not Aval 1
Not Avail
Not Avail
Not Avail
Not Avail
Not Avail
Estimated
Thickness
(mm * Ft)
1.8 * .0059
1.4 = .0046
0.6 = .0020
0.6 = .0020
1.4 = .0046
0.6 * .0020
1.8 = .0059
0.6 = .0020
1.4 = .0046
1.8 = .0059
Cubic Feet
of Oil
20.24 x 104
1.57 x 104
.96 x 104
3.49 x 104
7.89 x 104
1.37 x 104
11.74 x 104
4.46 x 104
21.78 x 104
3.84 x 104
77.34 x 104
Barrels of
oil
(1 barrel =•
31.5 Gal.)
4.80 x 104
.37 x 104
.22 x 104
.82 x 104
1.87 x 104
.32 x 104
2.78 x 104
1.05 x 104
5.17 x 104
.91 x 104
18.31 x 104
-------
472 PHYSICAL - BIOLOGICAL EFFECTS
0645 MILES
Figure 2: Shell Platform, Block 26s Timbaliei Area (12-9-70)
Figure 3: The Location of the Main Pass. Block 41
interested observations to an emissivity function. Another
point of interest is that emissivity, reflected as infrared
"coolness" or darker gray levels, appears to be a function of
oil thickness. Thicker oil causes an apparent emissivity
decrease appearing colder in the imagery. Thin oil allows
some penetration of underlying water radiation and thus
becomes a function of an oil/water combination. The exact
relationship between oil thickness and infrared temperature
has not been quantified and indeed may be a function of oil
type.
A number of other remote sensors such as ultraviolet
and multispectral photography have proven valuable for
documenting oil spills. They are limited to daylight and
relatively cloud free conditions. Solar angle and amount of
lighting introduce multiple variables into reflectivity
measurements that are difficult to quantitize. As our
objective is to quantify oil spills, these methods will not be
discussed.
Two systems, infrared and microwave, have now been
defined which can effectively operate under day/night and
relatively bad weather conditions. These two systems, when
operated in concert, can be used to locate, track and
determine the volume of oil on sea surfaces. In cases of
-------
BEHAVIOR OF OIL .
473
8-14,u IR Image
Oil Thickness by Zones
13.7 GHZ Microwave
( 10,000ft
Radiometric
isoohrs
Profile
3-11-70)
45'
Figure 4
flowing spills, such as the Gulf of Mexico events, fair
estimates of flow rates and the effectiveness of clean up
operations can be determined. Also, the temporal image
(IR) pattern change .can be used to forecast and hindcast
surface movements of spills.
Volumetric Calculations and
Flow Rate Determinations
This discussion of volumetric and flow rate
determinations is primarily concerned with technique.
While the derived values are of the proper order of
magnitude there may be some errors. The techniques used
are simple known methods of analysis that can be
performed rapidly and without highly specialized
equipment.
The Main Pass Block 41 oil spill which occurred in
March of 1970 is used as an example. This spill (Figure 3),
about 110 miles southeast of New Orleans, threatened
several tens of miles of Louisiana coast line.
An examination of several sets of images taken over a
period of fourteen days shows that on the eleventh of
March the ocean surface currents shifted in manner such
that the entire spill was displaced. This displacement
permitted temporal analysis so that two different
volumetric calculations could be compared.
The data sets utilized consist of thermal infrared
(8-14^) imagery and a microwave radiometric (2.2mm)
profile obtained at 1300 hours (local) from an altitude of
10,000 feet and infrared imagery obtained from 35,000
feet at 1630 hours (local). Microwave radiometric profiles
from the 35,000 foot overflight could not be used because
the resolution was too gross to be of value.
Figure 4 is the data set obtained from 10,000 feet. The
infrared gray levels associated with oil contamination were
divided into three units; dark gray for thick oil, medium
gray for intermediate thickness and light gray for thin oil.
These divisions were used to visually zone the spill into
units. The actual ground area of each zone was determined
using a model 62-0022 K & E compensating polar
planimeter. Each zone was measured four times and the
average area used. The cross track scale factor was
determined by using the known angular scan angle and
radar altimeter data. The along track scale factor for the
imagery was determined by using doppler ground velocity
data and time. Scale factors for the 35,000 foot imagery
were obtained by using the ratio distances between fixed
points (platforms) discernible in both the 10,000 and
35,000 foot imagery. Thus, if the scale factor of the 10,000
foot imagery was in error the same error would be
translated to the 35,000 foot imagery and the determined
area values are correct relative to each other.
In Figure 4, which is a composite of infrared imagery.
the microwave profile and visual infrared zoning, the three
units of the data set are correlated on a point-to-point basis.
The two white lines on the infrared image represent the
microwave radiometric ground track and the small white
dots are microwave radiometric data points.
-------
474 PHYSICAL - BIOLOGICAL EFFECTS
The logic and assumptions used to quantify the data are
as follows:
A. From the Melpar Report, it was assumed that oil
thickness did not exceed two (2) millimeters.
B. The infrared image density (gray level) is an indicator
of oil thickness. The darker areas are cooler because
the thicker oil more completely masks the IR effects
of the underlying water.
C. Increases in microwave radiometric temperature of oil
over that obtained from open ocean, is due to the
presence of oil. The increase has a linear relationship
to oil thickness at microwave wave4ength utilized (22
mm).
D. Because the microwave radiometer resolution cell is
large (700 feet in diameter) the integrated
temperature value is due to the statistical oil
thickness of the entire cell (automatic data
compression).
E. By combining oil spill distribution from the IR with
statistical thickness values obtained from the
microwave system, volumetric values of total oil can
be obtained.
F. Differences in volumetric values determined as a
function of time, can be used to obtain a good
estimate of flow rate.
G. The sea state of the surrounding open water and that
occupied by the oil spill are the same.
From Figure 4, it was determined that the maximum
attained microwave temperature was 270°K and the open
ocean background temperature was 212°K (all
temperatures are raw uncorrected values) a difference of
58°K. This value was used to represent a thickness of two
(2) millimeters. The average microwave temperature was
then determined for each zone and appropriate thickness
assigned. The conversion to quantitative values is shown in
Table 1.
The same procedure was used for the 35,000 foot
imagery (Figure 5). In this case no microwave data were
obtained. However, it was assumed that the thickness of the
infrared zones did not change appreciably and thickness
values determined from the 10,000 foot data were
appropriately assigned. The results of these calculations are
shown in Tables 1 and 2.
Comparison of the determined volumes shows a
differential of 1300 barrels accumulated during the, three
and one hah0 hour period between data acquisition sets.
This is about 370 barrels per hour using the convention of
31.5 Imperial gallons per barrel. If the petroleum industry
convention of 42 gallons per barrel is used the flow rate is
292 barrels per hour, which seems to be a reasonable
quantity.
It should be pointed out that the two data sets show
that the shift in surface currents caused the oil to deviate
about 170° away from the confining barrages. This means
oil "pick up" was minimal between images and the
calculated flow rate more nearly correct.
This example of using remote sensor systems for
calculating total oil in a spill and perhaps determining flow
rate is for demonstrating a quantitative technique rather
than quantitizing the Chevron incident. The data presented
are gross and the transfer functions between data sets
contain some assumptions that may well be questioned.
Small errors in planimetry can result in significant errors in
quantities of total ofl, However, even when potential errors
are considered, the technique is valid" and the rapidity of
data turn around (a matter of hours) justifies further
development.
Theoretical Surface Diffusion
The previous empirical calculations show some
relations to research work performed by Murray, Smith and
Son GO, members of the technical staff at the Coastal
Studies Institute, Louisiana State University. They applied
the statistical theory of turbulence developed by G.I.
Taylor in 1935, primarily for one dimensional gaseous
particle spread, to ocean surface diffusion of oil. The
primary reason for including their work in this presentation
is that the developed theoretical models are remarkably
similar to the infrared images obtained on March 11th. Also
the models strongly indicate that if sufficient physical
oceanographic data are acquired very good hindcasts and
forecasts can be made on slick movement.
Murray, et. al., performed derivations on Taylor's
original formula to arrive at:
doy
(V-2,1'2
dx
for short diffusion times, and
doy2
2 V'2 Cy*
dx
for long surface diffusion times.
where;
ay = variance of fluid particles around the source
y -2 = square of turbulence intensity
u = horizontal mean flow of the transporting medium
Cy* = Langrangina eddy size
A pictorial representation of this model is shown in
Figure 6 and the resemblance to the Block 41 spill
configuration is quite apparent. They carried the derivation
further by considering the spread of oil on water from a
point source as a two dimensional process in the X-Y plane
with only horizontal motion. That is the spread of oil and
the shape of the slick is controlled by surface phenomena
only. This led to a shape factor which defines the ratio of
slick width to dick length. The results of which are shown
-------
BEHAVIOR OF OIL . 475
8-14ju I R Image
MEDIUM THICK OIL
Oil Thickness by Zones
35,000ft. 1630hrs. 3-11-70
Figure 5;
-------
476 PHYSICAL - BIOLOGICAL EFFECTS
in Figure 7, where the slick configuration is theoretically
plotted as functions of time and surface current velocity.
Fortunately, the comparative model, u=0.6 knots, is for
March llth, the same day that the actual infrared imagery
was acquired. The comparison of theoretical slick
configuration with actual image configuration is
remarkable.
What this all means is that if surface current data are
available IR imagery can be used to determine how long a
slick has been present and the source dkection can be
hindcast. Of course this assumes a point source and
somewhat steady state surface current, but at least good
attempts are being made to match theoretical modeling
with actual slick configurations and these attempts appear
to be headed in the right direction.
CONCLUSIONS
The utilization of thermal infrared and microwave
radiometric sensors, approached from a systems analysis
point of view, if of great value to operational programs for
cleaning up oil pollution in ocean and coastal water
environments. In addition these systems can be used to
increase the value and upgrade theoretical models so that
they more nearly match field observations. The preliminary
findings of this study point to fruitful areas of directed
applications research and the techniques should be pursued
with vigor and proper governmental funding.
There is a great need to properly relate theoretical
models such as those developed by Murray, et al., to actual
oil spill movements. This can be accomplished by
correlating temporal acquired imagery with surface
oceanographic data. Once the true relations between
physical surface oceanography, oil spill configurations, and
oil movements have been firmly established the need for
surface data will be greatly reduced. This will ultimately
result in greatly reduced costs for spill tracking, source
identification, terminal destination determination and
determining the efficiency of clean-up operations.
REFERENCES
1. Melpar. (1969). Oil Tagging System Study Summary
Report Contract No. 14-12-500 Federal Water Pollution
Control Administration, Pages 1-3.
2. Lowe, S.D. and P.G. Hasell, (1969), Multispectral
Sensing of Oil Pollution; Proc. 6th International
Symposium on Remote Sensing of Environment, pages
755^-765.
3. Estes, I.E. and Bed Golomb, (1970), Monitoring
Environmental Pollution; Journal of Remote Sensing,
Volume 1, pages 8-13.
4. Murray, S.P., Smith, W.G., and Sonu, C.J.
Oceanographic Observations and Theoretical Analysis of Oil
Slicks During the Chevron Spill, March, 1970. Technical
Report No. 87, Coastal Studies Institute, Louisiana State
University.
Figure 6: Linear, Transitional, and Parabolic Diffusion Regimes Predicted by Taylor Theory
-------
= 3.5 houri
U-.6 knot
louiiiono ilick
March II, 1970
U = .S knot
Ar.o=48.2 km'
1 = 22.2 hour.
= .2 knot
Ar»0=301 km
. • 1 = 5.7 dgyi f
10
20 km
Theoretical tllckn K=4x)09 cm*/t*c
Q-IOOO fabl/day
oa
m
x
>
0
73
a
-n
Figure 7: Comparison of Observed Slick Against Theoretical Slicks, Illustrating Effect of Decreasing Velocity of Slick Size
-------
A DISCUSSION OF THE FUTURE OIL SPILL
PROBLEM IN THE ARCTIC
LTJGJ.L. Glaeser
Pollution Control Branch
Applied Technology Division
Office of Research and Development
United States Coast Guard
ABSTRACT
Future oil production in Arctic regions will present the
opportunity for oil pollution as a result of human error and
equipment failures. In order to attain an insight into what
may be expected, an assessment of the magnitude of future
oil spillage is presented. In addition, factors affecting the
fate and behavior of spilled oil are discussed based on the
results of the U.S. Coast Guard's Arctic Oil Spill Test Pro-
gram.
The Coast Guard's program to contend with oil spills in
the Arctic has one aspect unusual to today's pollution re-
search; it is investigating an area which has yet to surface as
a major problem. Although this approach should ultimately
prove to be wise, the researcher is initially faced with hav-
ing to predict the nature of the problem so that he can
prepare a logical plan of attack. This presentation will
therefore attempt to better define the causes and effects of
the potential arctic problem by presenting some of the
existing information on the topic.
Definition of the Future Problem
One need only look at the potential reserves available
for development to appreciate the possible oil pollution
problem in the Arctic. In addition to the well known fields
at Prudhoe Bay, two other areas show promise for develop-
ment, the Mackenzie Basin and the Arctic Islands, both in
Canada. 1 It has been estimated that the total reserves in
these areas may exceed 150 billion barrels.2 In order to
bring this oil to market, it appears that three systems of
transportation may be used, the Trans-Alaskan pipeline, a
Mackenzie Valley pipeline, and a system of icebreaking
tankers.3 The use of tankers to bring oil from the Arctic
Islands appears to be the most logical approach since they
are well removed from the mainland. Industry has indicated
its commitment in this area by holding 177 million acres in
the Arctic Islands for possible future production of oil.4
Although some information is available concerning the
extent of oil reserves in the Arctic, only previous statistics
can be used to forecast the amount of pollutants which
may eventually enter the environment. Probably the most
closely relatable area is Cook Inlet in Alaska. A study of oil
dissipation and biodegradation in Cook Inlet has estimated
the input of petroleum hydrocarbons from accidental spills
and effluents to range annually from 10,000 to 17,000 bar-
rels, or approximately 0.03 percent of the oil produced and
handled in the area.5
This figure compares with Dr. Max Blumer's estimate
that 0.10 percent of the oil transported over the sea is
spilled.6
It is estimated that by 1975 oil production on the
North Slope of Alaska will range from approximately 1 to
1.5 million barrels per day, and by 1980, 2 to 2.8 million
barrels per day.7 Therefore if only as little as .01 percent of
the oil produced is spilled, an average of 8400 gallons will
be discharged into the environment on a daily basis, or
approximately 1000 tons per year. This really represents a
minimum figure as it accounts for only the North Slope. A
tanker with only one compartment damaged could dis-
charge as much as 25,00 tons of oil into the environment
by itself.
It is interesting to note that the Trans-Alaskan Pipeline
System is designed to ultimately transport 2 million barrels
per day.8 Thus it can be seen that by 1980 it will be oper-
ating at capacity and other facilities for transport will be
required.
The oil discharges in Cook Inlet result mainly from oil
production at fifteen offshore drilling platforms. A similar
479
-------
480 PHYSICAL - BIOLOGICAL EFFECTS
situation should be expected off the North Slope, where
the State of Alaska has leased much acreage in the Beaufort
Sea.9 This is in shallow water semi-protected by a long
series of islands 2 to 12 miles north of the beach.10 How-
ever, the production hazards associated with the environ-
mental conditions are hardly less than in Cook Inlet. The
shallow water and near absence of tides should simplify oil
production in this area, but a large number of wells would
increase the number of opportunities for accidents.11 It
should be expected that eventually production will be
attempted in the deeper waters, where drilling rigs and
associated pipelines will be subjected to the full impact of
the ice pack.12
Great hazards are also associated with shipping. Ice
pack forces can be severe enough to immobilize or damage
ice-breaking tankers of present design. Should a tanker be
immobilized in ice, it is possible that the ship would be
grounded by the moving ice pack.
An examination of 36 major spills in the past has
shown that 75 percent of the spills were associated with
vessels, of which 90 percent involved tankers and one half
were associated with groundings.13 Of the 36 major spills.
50 percent varied between 5,000 and 100,000 barrels, 70
percent were over 5000 barrels, and 15 percent were over
200,000 barrels. Thus we have an indication of the possible
hazards associated with the shipping of oil.
Very little information is available concerning the ex-
tent to which oil pollution in the Arctic may affect the
ecological balance. It has been speculated that a spill of a
very large magnitude could adversely affect plankton and
disrupt the food chain.14 However,the most damaging re-
sults are likely to be the direct effects on birds and mam-
mals.1 5 It is estimated that several million birds and water-
foul migrate along the Beaufort Seacoast and depend on
ice-free water for feeding. 16 These birds would be harmed
by contact with oil. Polar bears and possibly seals are also
vulnerable to harm as a result of exposure to oil.
The Fate and Behavior of Spilled Oil in the Arctic
Oil which has been spilled on water is subject to several
important natural processes: dispersion (spreading), eva-
poration, solution, absorption, biodegradation, and ultra-
violet oxidation. The relative effect of each process will
vary somewhat with geographical location, and considerable
difference will be found between their effects in Arctic and
temperate regions.
Figure 1 - One of the two devices used to release oil over ice and water
-------
PROBLEMS IN THE ARCTIC 481
A better understanding of the most important of these
processes was gained as a result of the U.S. Coast Guard's
Arctic Oil Spill Test Program, which was conducted on an
ice floe in the Chukchi Sea in July 1970.1? As part of the
program, a number of small oil spills were made to obtain
information on the spreading behavior of crude oil, its
interaction characteristics with ice, and its aging charac-
teristics in theArcticenvironment.
Depending on the season and the kind of accident, oil
may spread on ice, under ice, on water, or in several modes
at once. For this reason, experiments were designed to
quantify the spreading behavior of Prudhoe Bay crude in all
three modes.
Spreading on Ice
The spreading experiments on ice were conducted
using two 55 gallon release tanks like the one shown in
Figure (1). In order to account for all the possible variables
in a future accidental spill, the parameters of volume, vis-
cosity, density, temperature, and release rate of the oil were
varied. The oil volume was varied by using one or two
release tanks, the oil density and viscosity by using diesel
oil or Prudhoe Bay crude, and the release rate by varying
the size of the orifice through which the oil was released.
Spreading rates were measured by manually timing the lead-
ing edge of the spilled oil as it passed a series of stakes
planted in the ice.
Both the diesel and crude oils were found to spread
easily over the ice surface, but were contained in a small
area by the natural surface irregularities. The ice surface
was porous, consisting of a layer of recrystalized ice
approximately two inches thick. This surface layer was
found to absorb up to 25 percent of its volume in oil, but
did not prevent the oils from migrating through the layer
because of gravitational forces.
It was planned to use the spills as a model test in order
to predict the behavior of larger spills, but the ice surface
proved to be too rough and absorbent. However, relation-
ships were found in the data which provide a better under-
standing of the spreading process.
The viscosity of the Prudhoe Bay crude tested is light
enough to allow it to spread easily under summertime arc-
tic conditions. Colder temperatures in the winter, however,
will lower the viscosity of the crude sufficiently to cause it
to apparently freeze. At all times the natural roughness of
the ice surface will act to contain spilled oil.
Spreading on Water
The nature of crude oil spreading on the water surface
was investigated in a manner similar to the investigation of
spreading on ice. In this case the Prudhoe Bay Crude was
discharged into a 100 foot long "U" shaped channel con-
structed on the surface of a melt pond. A conventional oil
boom was used. The progress of the oil front down the
length of the channel was manually timed.
Only one run of the experiment provided usable data.
The data are presented in Figure (2). As can be seen in the
figure, a transition point was reached after which the oil
slick stopped spreading. The Prudhoe Bay crude reached
this stable configuration because of its surface tension
characteristics. It would not spread to a film thinner than
approximately 5mm. After the slick reached this thickness,
further movement was controlled only by the wind.
The data which were taken during this experiment
compare favorably with theory developed for the spreading
of oil on warmer waters.18 This theory divides the spread-
ing process into three successive regimes in which certain
forces dominate. The first regime involves gravity and
inertia] forces, the second, gravity and viscous forces, and
the third, viscous and surface tension forces. The first
regime was not observed during the experiment because of
the release conditions. Figure (2) shows the theory for the
second and third regimes compared with the data. Spread-
ing did not take place in the third regime because of the
surface tension characteristics of the oil.
The ice present in the test area acted as a barrier to
hold back thin slicks blown against it by the wind. How-
ever, many of the leads in the ice were interconnected and
served as downwind escape paths for some of the floating
oil.
11.0
o.i
EXPERIMENTAL DATA
PHASE TRANSITION
SURFACE TENSION
SPREADING
GRAVITY-VISCOUS SPREADING
0 1
1.0
TIME/TRANSITION TIME
Figure 2 - Nodimensionalized data for spreading
of oil on water compared with theory.
Spreading under Ice
Spreading of Prudhoe Bay crude oil under ice was qual-
itatively assessed by using divers to observe the process and
take photographs. The oil was discharged below the ice by
physically pumping it through a hole in the ice.
As the specific gravity of the oil (approximately .89)
was not a great deal less than the water, it was not known
to what extent the oil would be dispersed by any turbu-
lence present. The oil was observed in all cases to rise to the
-------
482 PHYSICAL - BIOLOGICAL EFFECTS
underside of the ice and form in pockets, as is shown for 55
gallons of oil in Figure (3). Due to a general lack of turbu-
lence in the area, the oil pockets remained essentially
unchanged over a 24 hour observation period.
The behavior observed in this experiment can be gener-
alized somewhat further.^ Multi-year sea ice will in general
have a specific gravity of .85 as compared with .91 for pure,
salt free ice. The sea ice is of a lower density because of a
brine migration process which leaves the ice with a porous
structure. In comparison with the sea ice, crude oil will
almost always be more dense. The conclusion which may be
drawn, therefore, is that if given the opportunity, crude oil
will flow under multi-year sea ice because of hydrostatic
considerations.
Regardless of the season, the temperature at the under-
side of the ice will be that of the freezing water. At this
temperature, a typical North Slope crude such as the one
tested will have a low enough viscosity to flow easily. Multi-
-year ice in general has a very rugged underside, with pres-
sure ridges extending vertically downward as much as 150
feet. These features will tend to severely restrict the flow of
a large volume of oil by trapping the oil or causing the oil
to flow around the obstructions.
Considerations of the basic forces involved in the
spreading of oil under ice indicate that three time scales
exist for natural processes to take place.20 The first period
will last on the order of one hour, in which a stable pool of
oil establishes itself beneath the ice. The next period in-
volves gradual dispersion of the oil by any currents present,
and the third, a gradual dissipation by biological degrada-
tion and other processes. For reasons later presented, this
last time scale is probably extremely long.
Characteristics of Aged Crude
In order to either predict the fate and behavior of oil in
the Arctic or to develop methods to control it, an under-
standing of the basic nature of aged oil is required. As part
of the test program, samples were taken of Prudhoe Bay
crude which was allowed to age on ice, on water, and under
ice in the actual environment. The samples were then sub-
jected to physical and chemical analysis.
The physical analysis consisted of measuring the den-
sity, viscosity, and surface tension of the samples. As was
expected, the oil exhibited an increase in viscosity with
time, which is attributed chiefly to a loss of volatiles. Vis-
cosities of the aged samples are shown in Figures (4) and
(5). The specific gravity of the oil was correspondingly
raised, as is shown in Figure (6). Air-oil interfacial surface
tension exhibited little change after the first two days.
A chemical analysis of the samples produced data on
the boiling point distribution and ratio of saturated to
aromatic hydrocarbons. The analysis showed the oil to lose
ail of its gasoline and lighter fractions in a period of less
than five days, the loss probably occurring within two or
three days. Results of the ratio of saturated to aromatic
hydrocarbons were inconclusive.
Figure 3 - Crude Oil pocketing at the water -ice interface.
1000
Figure 4 - Viscosity of Prudhoe Bay crude oil aged on water.
-------
PROBLEMS IN THE ARCTIC 483
1000
345
10 20 30 40 50
TEMPERATURE (DEC C)
Figure 5 - Viscosity of Pruhoe Bay crude oil aged on ice.
1.00
.98
.96
i.94
s
s
:.92
.90
.86
o
A
A
G
O
A
O OIL A6ED ON ICE
A OIL AGED ON HATER
1,
0 2
6 8 10
TIME (DAYS)
14 16 18
Figure 6 - Specific gravity of aged Prudhoe Bay crude oil.
Although these observed trends will only occur under
summertime arctic conditions, they most likely represent
the case for which the greatest changes will take place. For
example, the loss of volatiles is not expected to be as great
in the winter because of the cold ambient temperatures on
the ice surface.
Biodegradation
It was speculated prior to performing the test program
that : summertime arctic temperatures may allow the
growth of organisms which could effectively degrade spilled
oil. As a result, surface water samples were taken and
analyzed. Fungi were found which were able to utilize a
particular hydrocarbon at elevated temperatures, and a
bacterium was found which showed growth at elevated tem-
peratures and was able to disperse certain test oils. No or-
ganisms were found which were able to utilize or disperse
oils at summertime arctic temperatures, although this does
not preclude the presense of such organisms.
Biodegradation is not expected to be a significant fac-
tor in the fate of oil trapped underneath an ice field for
several reasons.21 A great amount of oxygen is required to
oxidize oil. It has been estimated that it requires all the
oxygen in 320,000 gallons of sea water saturated with oxy-
gen to oxidize one gallon of crude oil.22 \n addition, ice on
the surface and salinity stratified water beneath the ice may
inhibit a supply of oxygen to the oil. And finally, the oil
will have a relatively small surface area due to pocketing at
the ice-water interface.
Biodegradation appears to be a significant factor in
Cook^Inlet, where the ambient surface water temperatures
are 5°C, as compared with 0°C north of Pt. Barrow.23
Surface turbulence resulting from wind and current forces
are common in the Cook Inlet area and act to disperse oil
slicks. The dispersed oil is then more easily biodegraded.
Surface turbulence is not common in the Beaufort and
Chukchi Seas. It was concluded that b'iodegradation of
Cook Inlet crude oil in Cook Inlet is essentially complete in
one to two months.
Interaction with Ice
An oil spill on the surface of an ice field will result in a
greater than normal absorption of solar radiation and a re-
sulting melting of ice. The long term effect a dark layer of
oil may have on the delicate heat budget of the Arctic is
unknown, and therefore will require future research.
A spill on the ice surface was investigated during the
test program. Results show that the two major factors
affecting the heat exchange at the oil spill were the radia-
tion balance at the surface (both incoming and reflected)
and the heat utilized in melting ice. The oil covered ice
absorbed approximately 30 percent more radiation than the
clean ice, and as a result initially melted ice at a rate of
approximately 2 cm/day greater than the clean ice.
Other Factors
Solution and absorption into ice are two other factors
which may substantially affect the fate of spilled oil. Little
-------
484 PHYSICAL - BIOLOGICAL EFFECTS
is known about these factors in the Arctic, although it is
expected that their time scales are equal to or greater than
that of evaporation. Ultraviolet oxidation is not expected
to be a large factor because of low winter light levels, insu-
lation'of oil by ice cover, and low oil surface areas of
exposure.
In addition to the fate and behavior studies conducted
during the Arctic Oil Spill Test Program, several methods
for removing oil from the environment were tested. It was
found that the Prudhoe Bay crude contained enough vola-
tiles to allow a small spill to bum to a small residue without
the aid of any burning agents. It is now known to what
extent this method would be effective on a large spill.
Straw and peat moss were found to act as effective
absorbants on spilled Prudhoe Bay crude, although the
straw proved to be easier to use.
SUMMARY AND CONCLUSIONS
Based on the results of the test program, the relative
importance of factors affecting the fate and behavior of
spilled oil are better understood.
If oil is spilled in the vicinity of pack ice, the spreading
of oil will be restricted by the presence of the ice. Prudhoe
Bay crude spilled on water will be moved by the wind, but
may not spread out into thin films.
Crude oil spilled under summertime conditions will
become relatively more viscous and dense as it ages. If given
the opportunity, crude oil may spread below an ice field,
where its, fate will be subject to solution, absorbtion into
ice, and dissipation by current. Biodegradation may not
significantly affect the fate of spilled ofl.
Oil spilled on ah ice surface will provide heat to the
environment by the absorption of solar radiation and will
melt ice underneath itself at a relatively higher rate than sur-
rounding ice.
Although a better insight into the potential Arctic Oil
Pollution problem has been achieved as a result of the U.S.
Coast Guard's test program, further research is required to
fully understand the behavior of ofl spilled in the Arctic.
The Coast Guard will continue its research in this field,
investigating such areas as the spreading of large volumes of
oil in an ice field and the aging of oil under winter condi-
tions. With this additional information we should be able to
define the scope of the cleanup problem and then develop
both methods and equipment to control future arctic oil
spills.
1. Sproule, John C», "All Three Arctic Regions Will See
Intense Activity in Next 5 Years," Oil and Gas Journal,
April 20,1970, p. 118-119.
2. Ibid.
3. Ibid.
4. Underfill!, J.C., 'The Future of Oil and Gas Development
in the Canadian North," in Slater, B, Arctic and Middle
North Transportation, Arctic Institute of North America,
Washington, D.C., 1969, p. 99-107.
5. Kinney, PJ., Button, D.K., and Schell, D.M., "Kinetics
of Dissipation and Biodegradation of Crude Oil in Alaska's
Cook Inlet," Proceedings, Joint Conference on Prevention
and Control of Oil Spills, American Petroleum Institute,
New York 1969, p. 333-340.
6. Blumer, M., "Oil Pollution of the Ocean," in Hoult, D.P.,
Oil on the Sea, Plenum Press, New York, 1969, p. 65-80.
7. Report by the U.S. Cabinet Task Force on Oil Import
Control, The Oil Import Question, U.S. Government Print-
ing Office, 1970, p. 235, 237.
8. 'The Impact of Prudhoemania," Oil and Gas Journal,
April 20, 1970, p. 146-156.
9. Brooks, J.W., "Environmental Influences of Oil and Gas
Development with Reference to the Arctic Slope and Beau-
fort Sea", Bureau of Sport Fisheries and Wildlife, 1970, p.
43.
ll./Wd.,p.44.
\2. Ibid., p. 43.
13. Gflmore, G.A., et al., "Systems Study of Oil Cleanup
Procedures," Final Report to American Petroleum Institute
by Dillingham Corp., 1970, Volume I, p. 7ff.
14. Brooks, op. cit., p. 47
1S.IWL, p. 48.
16. Ibid., p. 48.
17. Glaeser, J.L., and Vance, GP., "A Study of the Behav-
ior of Oil Spills in the Arctic," 1971, AD 717142, National
Technical Information Service, Springfield, Virginia.
18. Fay, J.A., 'The Spread of Oil Slicks on a Calm Sea," in
Hoult, D.P., (ed.),0/7 on the Sea, Plenum Press, New York,
1969, p. 53-63.
19. Hoult, DJ*., "Engineering Research on Oil Spills in the
Arctic", a proposal submitted to the U.S. Coast Guard by
the Massachusetts Institute of Technology, January 1971.
20. Ibid.
21. Ibid.
22. Blumer, M., Testimony before the Subcommittee on
Air and Water Pollution, Senate Committee on Public
Works, Machias, Maine, September 9, 1970.
23. Kinney, op. cit.
-------
EFEECTS OF EXPOSURE TO OIL ON
MYTILUS CALIFORNIANUS
FROM DIFFERENT LOCALITIES
Robert Kanter and Dale Straughan
Allan Hancock Foundation,
University of Southern California
and
William N. Jessee
Biology Department
Humboldt State College
ABSTRACT
The results of the first two of a series of experiments in
a study to determine if organisms exposed to natural oil
seepage have a higher tolerance to a spUl of similar crude oil
than organisms that have not been exposed to natural oil
seepage are presented. Mytttus califomianus from different
localities along the California Coast were exposed to
varying crude oil concentrations in the laboratory. The data
shows a higher tolerance to oil in M. califomianus from a
natural oil seep area than in M. califomianus from non-oil
seep areas. There is also a different tolerance to oil between
M. califomianus from different non-oil seep areas.
INTRODUCTION
The results of a recent study of the "after effects" of the
1969 oil spill in the Santa Barbara Channel, indicate that
mortality among the fauna in the area was not as great as
initially predicted. The field data suggest that most of the
mortality was due to physical effects (e.g. smothering of
Chthamalus fissus) and not toxic effects of the oil
(Nicholson and Cimberg, 1971).
The Santa Barbara area has been long exposed to natural
oil seepage and it is hypothesized that animals in this area
have developed a greater tolerance to Santa Barbara crude
oil than that possessed by animals that have not been
exposed to this natural seepage. This paper presents results
of the first two of a series of experiments to test this
hypothesis.
The experiments were conducted on the mussel, Mytilus
califomianus Conrad. This intertidal species is wide ranging
(Alaska to Baja, California) and survives well under labora-
tory conditions. It is abundant on the open coast both in
areas subjected to oil from natural seepage and in non-oil
seep areas.
Materials and Methods
In the first experiment (28 June-7 July, 1970) all
animals were maintained in unfiltered seawater at fluctua-
ting room temperatures and in irregular light and dark
periodicities. 60 M. califomianus were collected from a
rocky reef at Coal Oil Point (a natural oil seep area), and 40
M. califomianus from a man made metal groin at East
Cabrillo (a non-oil seep area). Twenty specimens of a
similar size range were placed in each of five aquaria
containing four liters of liquid. That is, two aquaria
contained animals from East Cabrillo and the other three
aquaria contained animals from Coal Oil Point. One aquaria
from each locality contained seawater only (the control),
one aquaria from each locality contained 40 ml oil plus
seawater (1 x 104 p.pm. oil), and the fifth aquaria (Coal
Oil Point only) contained 4 ml oil plus seawater (1 x 103
p.p.m. oil).
Seawater and oil were changed daily at which time dead
animals were removed and their shell length recorded. The
experiment was terminated after 10 days.
The second experiment (25 August-27 September 1970)
was carried out in a constant environment chamber where
water temperatures were maintained at 15±2°C* and there
was a constant cycle of 14 hours of light and 10 hours
darkness. Filtered seawater was used in this experiment. 80
M. califomianus were collected from jetty piles at Pismo
Beach (a non-oil seep area), a rocky reef at Coal Oil Point (a
natural oil seep area) and a rocky shoreline at Big
Fisherman's Cove, Santa Catalina Island (a non-oil seep
area), respectively (all localities are in southern California).
As in the first experiment, animals from each locality were
divided into groups of twenty of a similar size range and
*On September 4 to 6, the refrigeration system broke down and
temperatures rose to 20.0° and 20.S°C respectively.
485
-------
486 PHYSICAL - BIOLOGICAL EFFECTS
maintained in aerated aquaria containing four liters of
liquid. One aquaria from each locality contained filtered
seawater only (the control), one aquaria from each locality
contained 400 ml of oil plus filtered seawater (1 x 10s
p.p.m. oil), one aquaria from each locality contained 40 ml
of oil plus filtered seawater (1 x 104 p.pjn. oil), one
aquaria from each locality contained 4 ml of oil plus
filtered seawater (1 x 103 p.p.m. oil). Oil and seawater were
changed at approximately 48 hour intervals. Dead animals
were removed and their numbers and shell lengths recorded.
The Santa Barbara crude oil that was used in these
experiments came from offshore oil fields on the Rincon
trend. The aquaria were 8 liter plastic containers with
round corners to facilitate easier removal of oil when oil
was changed. Water was always placed in the aquaria first
and then oil was added so that the oil floated on the surface
of the water. All mussels were well below the surface of the
water and did not come into direct contact with floating
oil.
RESULTS
100
80
60
40
t
20
EAST CABRILLO
—CONTROL
-h103ppmOIL
2 3 4 5 6 7 8 9 10
TIME IN DAYS
Figure 1. Survival of M. cdifomiamu from East Cabrillo Beach
(Experiment 1).
EXPERIMENT 1 (FIGURE 1)
No mortality was recorded in animals either from the
control or the two experimental aquaria (1 x 103 and
1 x 104 p.pjn. ofl) from Coal Oil Point. Two of the control
animals from East Cabrillo Beach died on the ninth day,
while all animals from East Cabrillo Beach were dead by the
ninth day when exposed to 1 x 103 p.pjn. ofl. These data
suggest that M. califomianus from East Cabrillo Beach (a
non-oil seep area) are less tolerant to ofl than M. cali-
fomianus from Coal Ofl Point (an ofl seep area).
EXPERIMENT 2 (FIGURE 2)
While no mortality was recorded in the control group
from Catalina Island, there was a 50% mortality during the
first two weeks in the control group from Pismo Beach, and
seven animals died from the Coal Oil Point control group
during the last 9 days of the experiment. More than 50%
mortality was recorded in all experimental groups from
Pismo Beach so that a 50% mortality was probably
associated with collection methods or laboratory condi-
tions. Reasons for the mortality among Coal Oil Point
control animals are unknown particularly as lower mortali-
ties were recorded in all experimental groups at the end of
the experiment.
100
It M
£?£ 40
20
100;.
ft"
ss 40
20
KEY TO FIGURES'
- — C0»l OIL POUT
—• PISMO BEACH
— CATAUNA
24 6 8 10 12 14 16 IB 20 22 24 2f 28 30 32 34
TIME III DAYS
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34
TIME IN DAYS
SI 40
dlPi
20
24 6 1 10 12 14 IS 18 20 22 24 26 28 30 32 34
TIME IN OATS
2 4 6 I 10 12 14 16 18 20 22 24 26 28 30 32 34
TIME IN DAYS
Figure 2. Survival of M. califomianus from Coal Oil Point, Pismo
Beach, Fisherman's Cove at Santa Catalina Island (Experiment 2).
The general trends at all three localities were (1) animals
started to die earlier when exposed to high concentrations
of ofl than when exposed to low concentrations of oil; (2)
more animals died when exposed to high concentrations of
oil than when exposed to low concentrations of oil. At all
experimental concentrations of ofl, mortality was lower at
Coal OH Point than at either of the two non-oil seep
localities. In all cases mortality was highest among animals
from Pismo Beach. At concentrations of 1 x 103 p.p.m. and
1 x 104 p.p.m. animals from Santa Catalina Island had a
mortality rate similar to that recorded among animals from
Coal Oil Point. At concentrations of 1 x 10s p.p.m. animals
from Santa Catalina Island had a mortality rate similar to
those from Pismo Beach. This data indicates a difference in
tolerance to ofl at the two lower concentrations, between
animals from two non-oil seep localities.
-------
MYTILUS CALIFORNIANUS 487
The constant production of new byssus threads was an
indication of normal healthy functioning animals in experi-
mental conditions. The analysis of data to determine if
mortality is related to size is incomplete.
Discussion
RELATIONSHIP TO FIELD CONDITIONS
In these experiments animals were not exposed to tidal
cycles nor were they exposed to the normal amount of
water movement. Coe and Fox (1962) indicated that
normal growth was uneffected by either of these factors.
The animals were not fed in either experiment. Coe and
Fox (1942) found that they could be maintained in the
laboratory for up to four months before there was a
significant number of deaths due to starvation. Hence one
could probably liken the laboratory conditions to condi-
tions found in a rock pool which never drained at low tide
and which received a fresh dose of oil daily (experiment 1)
and at two day intervals (experiment 2). In the first
experiment, water temperatures were above that of sea-
water so that the temperature regime was similar to that
experienced at low tide while in the second experiment
water temperatures were similar to those experienced at
high tide.
Santa Barbara crude oil is relatively insoluble in seawater
(R.L. Kolpack, personal communication) so that while the
over all ratio of oil and water used in one aquaria was 1
p.p.m. for example, most of the oil was at the surface of
the water and the concentration of oil in the seawater
would actually have been much less than this. No attempt
was made to prevent the aromatic compounds from
evaporating. Kolpack (personal communication) found a
very low percentage of light aromatic compounds in Santa
Barbara crude oil. Hence only a small fraction of the oil was
lost. This fraction would also be lost in the event of an oil
spill.
It is impossible to choose sampling areas in which the
only difference is the exposure or non-exposure of the
organisms to natural oil seepage. The areas chosen however,
are an attempt to come as close as possible to this ideal.
Coal Oil Point and East Cabrillo Beach are localities a few
miles apart within the Santa Barbara Channel. The former is
a long low reef while the latter is a man made metal groin.
Apart from substrate differences, one would expect little
difference in the effects of other pollutants although East
Cabrillo is in Santa Barbara and may be more subjected to
the effects of sewage pollution. Pismo Beach is north of the
Santa Barbara Channel in an area of lower pollution and
where water temperatures are slightly lower. Santa Catalina
Island is situated south of the Santa Barbara Channel, 20
miles offshore from Los Angeles and appears to be outside
the influence of pollution originating in Los Angeles.
COMPARISON OF EXPERIMENTAL DATA
Seasonal changes must also be considered when exam-
ining this data. Experiment 2 was not commenced until two
months after experiment 1. Crapp (1971) found seasonal
changes in tolerance of British marine invertebrates to
detergents. Until seasonal tolerances have been determined
as regards to oil, one should take into account seasonal
differences. Hence while data from different localities in
each experiment is comparable, data from experiment 1 is
not directly comparable with experiment 2 both through
the difference in methods used and possible seasonal
differences.
Data from these experiments is not comparable to data
obtained using standard bioassay methods such as those
proposed by Tarzwell (1969). In these standard methods,
oil and water are mixed on a shaker-no attempt was made
to mix oil and water in the present experiments.
In both experiments animals from Coal Oil Point (the oil
seep area) were more tolerant to oil than those from the
non-oil seep localities. This strongly supports the hypothe-
sis advanced to explain low mortalities following the Santa
Barbara oil spill. However, it would be foolish to accept this
as the complete explanation. Nicholson and Cimberg
(1971) suggest that it is only species with a high tolerance
to'oil that occur in areas exposed to natural oil seepage.
This suggests a preliminary selection which permits only
those species with some tolerance to oil to settle and
survive in the oil seep areas and that subsequent to this,
there is a further acclimation to the presence of oil. M.
califomianus does not brood eggs but releases gametes into
the sea. Since developing eggs and larvae are distributed by
ocean currents there is no long term isolation of M.
califomianus at Coal Oil Point enabling inbred tolerances to
oil to develop.
The lower tolerance of animals at East Cabrillo beach
than at Coal Oil Point indicates that the factors enabling
the survival of the Coal Oil Point animals in these
experiments are not operative throughout the whole Santa
Barbara Channel. This further supports the idea that the
higher tolerance is due to acclimation in the presence of oil.
The data presented support the hypothesis that M. cali-
fomianus that are exposed to natural oil seepage are more
tolerant to oil than M. califomianus that are not exposed to
oil seepage.
In experiment 2, there was also a difference in tolerance
to oil between animals collected at Pismo Beach and
animals collected at Santa Catalina Island. The reasons for
this are unknown. However, it does point to the fact that
there may be more physiological variations between differ-
ent populations of the same species than at present are
visualized.
CONCLUSIONS
1. Mortality started sooner and was greater when
animals were exposed to high concentrations of oil than
when animals were exposed to low concentrations of oil.
2. In each experiment mortality was lower in animals
from natural oil seep localities than from non-oil seep
localities.
-------
488 PHYSICAL - BIOLOGICAL EFFECTS
3. There was some variation in tolerance to oil between
animals from different non-oil seep localities suggesting that
there may be less physiological homogeneity between a
species at different localities than at presently believed. This
difference could be due to either man made changes
including pollution or natural factors, such as .range
extremes.
ACKNOWLEDGEMENTS
We wish to thank Union Oil of California and the Mobil
Oil Corporation for supplying oil used in these experiments.
The research was supported by a grant {GH-89) from the
National Sea Grant Program, U.S. Department of Com-
merce to the University of Southern California. We are also
grateful to Mr. William Walker at the Marineland of the
Pacific for assistance he has given in obtaining clean filtered
seawater.
REFERENCES
Coe, W.R. and Fox, D.L. (1942). Biology of the California
sea-mussel (Mytttus caKfomianus). 1. Influence of tem-
perature, food supply, sex and age on the rate of growth.
/. Exp. ZooL 90:1-30.
Crapp, G.B. (1970). Laboratory Experiments with Emulsi-
fiers. Paper presented at a Symposium on the Ecological
Effects of Oil Pollution on Littoral Communities at the
Zoological Society of London. 1 December 1970: 29-46.
Nicholson, N.L. and Cimberg, R.L. (1971). The Santa
Barbara Oil Spills of 1969: A Post-Spill Survey of the
Rocky Intertidal. In Biological and Oceanographical
Survey of the Santa Barbara Channel Oil Spill
1969-1970. Pub. Man Hancock Foundation: 325-400.
Tarzwell, C.M. (1969). Standard Methods for the Deter-
mination of Relative Toxicity of Oil Dispersants and
Mixtures of Dispersants and Various Oils to Aquatic
Organisms. Proceedings of Joint Conference on Presenta-
tion and Control of Oil Spills Sponsored by API and
FWPCA December 15-17,1969: 179-186.
FIGURES
Figure 1. Survival of M. caKfomianus from East Cabrillo
Beach (Experiment 1).
Figure 2. Survival of M. califomianus from Coal Oil Point,
Pismo Beach, Fisherman's Cove at Santa Catalina Island
(Experiment 2).
-------
THE MOVEMENT OF OIL SPILLS
Henry G. Schwartzberg
School of Engineering and Science
New York University
ABSTRACT
The effects of winds, waves, and currents, and the
physical properties of oil and water on the drift rates of oil
spills were studied in tests carried out in a combined water
basin wind tunnel. On calm water, oil drifted at a fairly
constant percentage of the wind speed regardless of the
nature and spreading, tendencies of the oil, the spill size,
and water temperature, depth, and salinity. Percent drift
varied with wind tunnel height. Extrapolation to infinite
height indicated that on calm open water wind drift should
be3.7%.
Shallow water waves, which produced no significant
drift themselves, reduced wind drift. Analysis indicated that
deep water waves produced by the wind should produce
significant drift, complicating wind drift prediction, but the
magnitude of the wind wave interaction effects is not yet
known. Test wind drifts and current drifts were found not
to be directly additive.
Background
To fight oil spills effectively we have to know the rate
and direction of spill movement. This work, sponsored by
the FWPCA and initiated at a time when such information
was fragmentary and scattered, was designed to develop
correlations for predicting spill movement. The same events
which stimulated this work triggered similar efforts on the
part of others and there is, no doubt, some overlap between
our results and theirs.
Equipment
A combined water basin wind tunnel fitted with a wave
machine and a current producing pumping system was set
up to test the factors most likely to influence oil spill drift.
This set-up, shown in Figure 1, consisted of a wind-tun-
nel-covered, 19-ft. long, 11.5-in. deep, 5-ft. wide test basin.
Two 19-ft. long, 12-in. wide, 11.5-in. deep return channels,
not under the wind tunnel, were installed, one on each side
of the basin and connected to it at its upstream and down-
stream ends. These channels provided a return route for the
wind induced surface flows, which were dead-ended at the
downstream end of the basin, and which otherwise would
have returned as submerged currents affecting the flow
structure and surface slope in the basin. Preliminary wind
drift test results obtained without the return channels were
much more variable and non-reproducible than results ob-
tained after installation of these channels. The channels
were also fitted with variable-speed motor-driven propellers,
which could be used to create currents in the test basin
when required.
The wind duct was constructed of polyethylene film
supported by slotted angle-iron frames, which could be
adjusted so as to vary the duct height. Tests were carried
out at wind tunnel heights ranging from 7 inches to 30
inches, most of them at a standard height of 22 inches. A
transition duct, fitted with grids to provide a uniform velo-
city profile and eliminate fan induced swirl, connected the
fan to the tunnel. Two fans were used: a 1/4 H.P., 12,000
SCFM free discharge unit, and a 3 H.P., 30,000 SCFM free
discharge unit. The wind velocities were varied from 7
ft/sec to 27 ft/sec by the choice of fan used, by varying the
fan speed and duct height, and by the use of inlet choking
grids. Wind speeds were measured by taking 9 or 15 point
traverses at the air discharge from the tunnel using a ro-
tating vane anenometer. These velocities were corrected for
the slight change in flow cross sectional area over the water
and in the discharge opening.
In the wind drift tests, oil was released near the upwind
end of the basin by lowering a retaining ring containing a
known amount of oil. The time required for the oil to
traverse a fixed distance (usually six feet) in the middle of
the basin was measured to the nearest 0.1 second. To avoid
end effects, which were readily apparent, drift rate mea-
surements involving drift movement over the first five feet
or the last five feet of the basins length were not used.
459
-------
490 PHYSICAL-BIOLOGICAL EFFECTS
"UD
Figure 1. Wind Tunnel Water Basin - F fan, T wind tunnel, B water
basin, R return channels, G wind grid, D oil release dam, O oil
supply reservoir, S adjustable angle-iron tunnel supports, C current
pumping motor driven propellers, WP wave paddle, WD wave
machine drive.
Usually ten runs were carried out for a given set of condi-
tions. Tests were carried out for non-spreading and spread-
ing oils, oils of different viscosity, different water depths,
different spill sizes, different water temperatures, and using
both clean and dirty salt and fresh water.
Results
The results of these tests at standard conditions (wind
tunnel height, 22 in.; water depth 7.5 to 10.5 in.; 50 ml.
spill volume; temperature about 22°C) are presented in
Figure 2, where the percent drift (oil drift velocity/wind
velocity) is plotted vs. wind velocity. To correct for the
slight non-uniformity in wind velocity profile, the percent
drift and wind velocity are based on the wind velocity along
the tunnel's center line, where the oil drift usually
occurred.
While there is a good deal of scatter in the data, the
average percent drift appears to remain fairly constant as
the velocity varies. For the forty tests (roughly 400 indi-
vidual runs) plotted, the percent drift averages 3.09%. The
average relative deviation is 6.2% (0.19 percent drift units)
and the maximum relative deviation is 19%. Some of this
variation is no doubt due to the difficulty experienced in
timing the movement of spills which deformed, broke, and
spread as they moved, but, based on the average drift varia-
tion for the individual runs in a given test, part of the
variation between tests appears to be due to other
indeterminate causes. The variation due to experimentally
controlled change was often relatively small when
compared to this random variation. For example, compared
to the average standard percent drift of 3.09% the following
average percent drift values were obtained: highly viscous
heavy paraffin oil, 3.11%; spills on low temperature water
(i.e. water having a viscosity 1.4 times as great as that at
22°C), 3.21%; crude oil at wind velocities below 18.5
ft/sec, 3.08%; 100 and 200 ml. spills, 2.98%; spills on high-
ly dirty water, 3.19%.
The average percent drift for the tests at wind velo-
cities below 18.5 ft/sec, where the small fan was used, was
3.14%, while that for velocities above 19 ft/sec, where the
IX
a
f
^f
5 10 IS 20
WIND SPEED (FEET/SECOND)
25
Figure 2. Percent Drift (Drift Velocity x 100/Wind Velocity) vs.
Wind Speed - O Light Paraffin Oil, A Heavy Paraffinn Oil. • Urania
Crude Oil, High Speed Fan Run (underlined),"Salt Water Run
(overlined).
large fan was used was 2.98%. This may be indicative of a
true reduction in percent drift as wind velocity rises, or it
may be an artifact due to the use of two different fans,
which provided somewhat different velocity profiles in the
two sets of runs. As pointed out later, waves cause a reduc-
tion in the percent wind drift, and the greater waviness
produced by the higher velocity winds may have caused the
noted reduction in percent drift. In the salt water tests.
which were all carried out at high wind velocities, the av-
erage drift was 2.96%, which is virtually identical with the
fresh water results for the same velocity range.
Paraffin oil, which forms lens-like pools, was used in
most tests at wind velocities below 18.5 ft/sec because the
sharper pool definition it provided permitted more accurate
timing and because it was easier to clean the pool after its
use. At wind velocities above 18.5 ft/sec paraffin oil pools
broke up badly and were difficult to see, so that crude oil,
which was much more visible, was used exclusively. Because
of the large number of crude oil tests run in the high velo-
city range, and the probable existence of a velocity or fan
dependent percent drift effect, only the low velocity crude
oil tests were used in the previously cited comparison of the
percent drift for crude oil.
Based on the evidence cited and tests using tetradecane
it appears that the percent drift is not strongly dependent
on the physical and chemical properties of the oil and
water, at least not over the normal range likely to be en-
countered.
Water Depth Effects
To determine whether the above results were app-
licable in deep water a series of tests were carried out in
which the effective water depth was reduced by the inser-
tion of false bottoms in the test basin. This expedient was
used in place of simply lowering the water level, because
lowering the water level also produced a concurrent var-
-------
MOVEMENT OF OIL SPILLS 491
iation in wind height. Further, when the water level was
reduced excessively, an air vortexwasscreated at the upwind
end of the basin. This vortex disturbed the wind velocity
pattern, causing localized reversals in drift and great irr-
egularity and reduction in the drift rate. In contrast, when
false bottoms were used and the effective depth was re-
duced to as little as 3.5 in., normal reproducibility was.
obtained, and the average percent drift was 3.14%. Because
of the influence of submerged return currents, and based on
the work of other investigators1, it is anticipated that the
percent drift would decrease at water depths lower than 3.5
in. The absnece of a depth effect over the range tested,
however, should indicate that these results are valid in
deeper water.
Wind Duct Height Effects
When the wind height over the water was changed, the
percent drift changed significantly. Compared to the 3.09%
drift at the standard tunnel height of 22 in. (wind height 24
in. due to water level depression), a 2.59% average drift was
obtained at a wind height of 15 in., and a 3.37% average
drift on limited tests at a 34-in. wind height. Since we were
interested in wind drift on open water we sought to de-
termine the percent drift at infinite wind height. Extra-
polation to infinite wind height was done by assuming that
the percent drift obeyed a relationship of the form:
D = DO - B/Hn (1)
where Do is the open water percent drift, H is the wind
height, D the percent drift measured under a wind tunnel, n
some suitable exponent, and B a constant. An empirical
best fit for such an equation can be obtained by plotting D
vs. l/Hn for various values of n, until the value which yields
the best straight line is found. The l/Hn = 0 intercept
yields D0.
It appeared likely that the duct height effect was due
to the increased water surface slope generated by the in-
crease in air pressure drop at low wind tunnel heights. This
pressure drop depressed the water level at the upstream end
of the basin. The drifting oil thus travelled up a slight slope
which became progressively steeper as the duct height de-
creased. For rectangular ducts in the air velocity range
tested the pressure gradients and hence the surface slopes
are proportional to 1/Hl-l?: hence a value of 1.17 was
used for n in Eq. 1. This yields a fairly good straight line
with an intercept indicating that Do is 3.7%. This value lies
between the 3.4% average value reported by Smith2 for the
Torrey Canyon spill, the 4.2% value reported by Tomczak3
for the Gerd Maersk spill, and the 4.0% average value
obtained by averaging Stroop's4 open sea test data. Since
there is a great deal of scatter about the average values for
these sets of data and the current and wave conditions are
not quantitatively known, it is quite possible that this
apparent measure of agreement is in part accidental.
Shear Stress Analysis
A simple theory provides insight as to the drift
mechanism. A somewhat idealized velocity profile for the
air water system is shown in Figure 3. The air moving at
O 1
UJ
AIR
WATER
U<
UA
VELOCITY
Figure 3. Wind and Water Velocity Profile
velocity Ua exerts a shear stress proportional to fa/>a(Ua -
Us)2 on the water surface, which drifts at a velocity Us.
The bulk of the water can be regarded as moving backward
at velocity Us relative to the surface. As a consequence the
water exerts a shear stress proportional to fw/owUs2 which is
equla to the air shear stress but oppositely directed. In
these expressions fa and fw> andpwandpw are the friction
factors and densities for the air and water respectively.
Equating the two stresses there is obtained:
(2)
The friction factors fa and fw for high Reynolds number flow
over a flat surface are correlated by expressions of the type:
f=K(LUp/Ai)-1/7
(3)
Substituting appropriate values for p, U, and the viscosities
jua and nw in Eq. 3, and then substituting Eq. 3 for fa and
fw in Eq. 2, there is obtained after cancellation of the
constant K and the flow length L and some rearrangement:
O.OlDo =
Upon substituting values for the densities and viscosities of
air and water there is obtained:
0.01D0 = Us/Ua=0.0318
The equivalent value for air and sea water is 0.0314.
(5)
-------
492 PHYSICAL-BIOLOGICAL EFFECTS
In our tests the drift rates for small pieces of polyethy-
lene film floating on the water surface were consistently
10% lower than the drift rates for oil at the same test
conditions. Based on this 10% correction the polyethylene
marker percent drift for open water should be about 3.3%,
which is fairly close to the 3.18% predicted by Eq. 5. The
polyethylene marker may be indicative of the water surface
drift as opposed to the oil drift. It is interesting to note that
if the oil density is substituted in place of the water density
in Eq. 4, while still retaining the water viscosity value, a
percent drift of 3.41% is predicted, which is substantially
closer to our experimentally based D0 value.
Drift and Spread Retardation
The percent drift for wood chips decreased rapidly as
the thickness of the chip increased. Chips 3/32-in. thick
drifted at 85% of the oil drift velocity, and 3/16-in. thick
chips at 75% of the oil velocity. This suggests that the rapid
decay of water velocity with depth shown in Figure 3 is
correct. Based on this observation it appeared likely that
drag surfaces attached to an oil pool and penetrating only
one to one and a half inches down into the water could
significantly reduce oil drift rates. When a pool of oil was
placed in the drag device shown in Figure 4, the percent
drift was reduced to 1.5% and no oil was lost. Other drag
devices also slowed down oil drift, but were less effective in
retaining the oil-which drifted at the normal rate once it
escaped. Foamed plastic nets, which essentially consist of a
multiplicity of surface enclosures somewhat like the ring
part of the device shown in Figure 4, were effective in
preventing or minimizing the spreading of oil spills while
drifting along with the oil. Such nets, which could be gen-
erated at sea if desired, might be a useful method for retard-
ing the spread of spills.
It is interesting to note that freely spreading oils could
be converted into lens form by the addition of suitable
surfactants at the spill site. The original lens broke up into
smaller lenses as the spill drifted under wind action, the
breakup being more severe the more intense the wind
action. Despite this breakup, the small lenses persisted and
spreading was retarded during downwind drift. Such lens
induction may represent a useful technique for minimizing
spill spreading in instances when spill confinement is im-
possible.
Wave Effects
Wind drift rates were measured in the presence of 4-in.
high waves having a one second period and roughly a 45-in.
wave length. In the absence of wind, these waves produced
negligibly small drift (0.01 ft/sec). In the presence of wind,
the waves, moving either with or against the wind, reduced
the percent drift to 2.66% as compared to the standard
3.09%. It is thus apparent that waves significantly interfere
with direct wind drift. It is believed that the drift reduction
occurs due to the presence of a wind shadow or vortex
induced drag-free or reversed-drag zone on the lee side of
the wave crest.
The wind-wave-drift interaction is considerably more
complicated than suggested by our experimental results.
6 I N.
1
1/4 IN. ROUND
STYROFOAM
I IN.LONG
WIRES
Figure 4. Spill Drift Retarding Device
While shallow water waves usually cause negligible surface
drift, as in our tests, it is well known that deep water waves
cause significant drift. Stokes5 derived the following equa-
tion, which has been experimentally verified and which pre-
dicts the drift velocity Ud caused by simple deep water
waves:
Ud = 27TA2 co/A = (27r/X)3/2A2gl /2 = w3A2/g (6)
where A is the wave amplitude (half the wave height), co
the wave angular frequency, X the wave length, and g is the
acceleration of gravity. The last two forms of this equation
arise out of the velocity, wave length, angular frequency
interdependence for deep water waves.
Ocean waves have a highly complex spectral composi-
tion, and therefore Eq. 6 is not directly applicable to them.
Chang6, has developed the following equation which pre-
dicts Ud for waves of complex spectral composition:
Ud =
g
S (c
(7)
where S(co) gives the spectral distribution of wave energy as
a function of co the angular wave frequencies making up the
spectrum. Since the energy content of a wave is propor-
tional to A2 the above integral effectively sums up the
Stokes drift for all the spectral components of the wave
field. The validity of Eq. 7 thus rests on the assumption
that each frequency component of the wave spectrum simu-
ltaneously produces its own drift and that all these individ-
ual drifts are additive.
Chang tested Eq. 7 by measuring the surface drift pro-
duced by artificially generated random long crested waves
in a deep water test basin, and apparently obtained good
-------
MOVEMENT OF OIL SPILLS 493
agreement. However the wave spectrum tested was narrow
.(periods ranged from 0.25 to 1.25 seconds, with the great
bulk of the wave energy being contained in the 0.4 to 0.8
second range). Upon examining the drifts produced, it app-
ears they could have been roughly predicted on the basis of
substituting the average wave height and average wave fre- '
quency in Eq. 6. It is therefore hard to tell whether Eq. 1,
which takes into account the whole spectral composition,
or Eq. 6 used with a single effective wave height and a
single effective wave length or frequency should be used in
predicting wave drift.
For wind generated waves on the ocean, in contrast to
the cited test basin work, the drift values predicted by these
two different approaches are markedly different. For ex-
ample, if wave drift estimates for fully developed wind
waves are based on substituting in Equation 6 the average
wave amplitude and the frequency where most of the
energy is concentrated for such fully developed waves, the
predicted drifts range from 0.04 knots for a 10 knot wind
to 0.33 knots for a 50 knot wind. Based on wind speed this
represents a 0.12% drift at 10 knots increasing almost
linearly to 0.65% drift at 50 knots. It is recognized that the
above calculations have only qualitative significance at best,
and that the above combination of amplitude and
frequency may not be the most valid one to employ.
However, these calculated results should serve for purposes
of rough comparison.
In contrast if one uses Eq. 7 by substituting, for
example, Pierson and Moskowitz'7 wave spectra correlation
for fully developed wind generated waves
S(w) = 0.00405(g2/w5) exp (-0.74(g/Uaw)4)
(8)
for S(£o) in Eq. 7 and carries out the indicated integration,
one obtains:
Ud/Ua = 0.022
(9)
for all wind speeds. That is the surface drift produced by
fully developed wind waves should be 2.2% of the wind
velocity. Not only does this percent drift remain constant
but it is substantially greater than the drift predicted by Eq.
9 is added to the direct wind drift predicted on the basis of
our experiments, neglecting for the moment the retardation
of direct wind drift caused by waves, the predicted
combined drift would be 5.9% of the wind velocity—which
is much higher than has been noted in field observations.
Even taking into account wave induced retardation of
direct wind drift, predicted combined percent drifts would
be of the order of 5.5%, which is still much too high.
Therefore the use of Eq. 9 appears invalid, and the use of
Eq. 7, on which it is based, appears suspect.
The wind-wave-drift interaction situation may be sum-
marized as follows. Winds induce direct wind drift, but at
the same time generate waves. These waves interfere with
and reduce direct wind drift, but at the same time give rise
to a surface drift themselves. This wave drift is a function
of the spectral composition of the waves, but the exact
functional form is debatable. Since spectral composition
depends on preceding wind history, and existing wind speed
and fetch, it is anticipated that the percent drift for spills at
sea should be a function of all these factors. There is,
however, some possibility that wave induced retardation of
direct wind drift and the drift produced by deep water
waves are of the same order of magnitude and thus may
largely cancel each other so that appraent percent drift of-
ten appears to be fairly constant.
Combined Wind and Currents Drift
Sixteen sets of tests were carried out in which floating
oil spills were subjected to both wind and current action.
The currents, generated by motor driven propellers in the
return ducts, were directed into the test basin through a
smoothed venturi-like entrance port so as to minimize
vortex formation. These currents were passed through a
series of grids near the upstream end of the test basin so as
to provide a uniform velocity profile. Without these pre-
cautions test results were extremely variable and
non-reproducible. The use of the grids, however, greatly
reduced the maximum current velocity that could be gen-
erated by the propeller driven pumping system.
In this series of tests the wind drift was measured in
the absence of currents, and the current drift was measured
in the absence of wind, and then the combined drift for the
same pumping conditions and wind speed was neasured.
The wind drifts tested ranged from 0.22 to 0.83 ft/sec, and
the current drifts from 0.15 to 0.37 ft/sec, with one test
being carried out at a reversed current of 0.19 ft/sec.
In all tests, including the one in which the current was
directed opposite to the wind, the apparent contribution of
the current to the combined drift was less than the current
drift in the absence of wind. This result was startling and
contrary to our expectation that the wind and current
drifts would be simply additive or nearly so. The combined
drift Ut was roughly correlated by the equation:
Ut = Us + 0.56Uc (10)
where Us is the wind drift and Uc the current drift. Al-
though the average deviation from this equation was only
6.4% and the maximum deviation 13.4%, the percent devia-
tions based on Uc- rather than Ut are substantially higher,
averaging 37.5%. Eq. 10 is suspect, and can't be correct in
general since Ut must approach Uc and not 0.56UC as Us
goes to zero. The available data, however, do not indicate
any trend toward an increased coefficient for Uc as Us
decreases.
The cause for the lack of additivity of wind and cur-
rent drifts has not been determined. It is believed that it
might be due to the vertical velocity profile of the current
altering the shear stress that is developed in the waterr near
the air water interface,
A more detailed description of the work reported
herein and additional work relating to the extent of spread
and the rate of spreading of oil spills may be found in
report number 150-80-EPL 04/70 of the Water Pollution
Control Administration (now the Water Quality Office of
the Environmental Protection Administration).
-------
494 PHYSICAL - BIOLOGICAL EFFECTS
REFERENCES: Bureau of Standards, Dept. of Commerce, Washington, D.C.
1. Hidy, G.M. and Plate, EJ.,/. of Fluid Mech., 26, p. (1927).
651 (1966). 5. Stokes, G.G., Trans. Camb. Phil. Soc., 8, p. 441
2. Smith, J.E. "Torrey Canyon" Pollution and Marine (1847).
Life," Cambridge (1968). 6. Chang, M.S., /. ofGeophys. Research, 74, p. 1515,
3. Tomczak, G., Ozeanographie, 10, p. (1964). (1969).
- 4. Stroop, D.V., "Report on Oil Pollution Ex- 7. Pierson, WJ. and Moskowitz, L., / ofGeophys.
periments, Behavior of Fuel Oil on the Surface of the Sea" Research, 69, p. 5181, (1964).
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OIL SPILL CLEANUP
Chairman: T. H. Gaines
Union Oil Company of California
Co-Chairman: J. H. Weiland
Texaco, Inc.
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AN INTEGRATED PROGRAM FOR
OIL SPILL CLEANUP
BY
W. E. BETTS andH. I. FULLER
Esso Research Centre,
Abingdon, Berks, U.K.
and
H. JAGGER^
Esso Petroleum Co. Ltd.,
London
ABSTRACT
This paper discusses the necessary requirements of an
integrated program for dealing with oil spills on water. Such
a program necessarily involves a designated administrative
organization, sound contingency planning, pre-selection of
equipment and materials to cover a range of techniques,
and a recognition of the importance of flexibility so that
the proper combination of techniques can be united into
the optimum operation to meet the special circumstances
of each individual spill.
This philosophy is illustrated by a description of the
administrative organization in the United Kingdom at
central and local government level, by the contingency
planning of one of the major oil companies, and by the
different combinations of confinement, removal, and other
techniques that have proved appropriate in Europe for
water surfaces ranging from streams to seas.
The paper emphasizes that the optimum cleanup
operation for the unique conditions of each spill requires
preparedness, flexibility and an integration of appropriate
techniques.
Integrated Planning
[_0il spills will occur in the future no matter how well
disciplined the oil industry becomes, how careful its
customers are in handling the products supplied to them, or
how stringent are the laws governing the storage and
distribution of those products. In most instances spills
require prompt attention whether they are at sea—as a
result of collision, grounding or careless discharge of
incompletely separated ballast water-or on land or on an
inland water surface. It follows therefore that detailed plans
must be drawn up to ensure that immediate action can be
taken wherever and whenever spills do occur. These plans
must be capable of covering all situations from the high seas
to the most remote inland location. They must utilize
suitable existing resources as much as possible yet ensure
the availability of specialized knowledge and equipment
when these are required;] The United Kingdom has
developed an integrated program which covers oil pollution
at sea in harbors and estuaries, on the beaches, and at any
inland location. The program is fully integrated in that
central and local government, the oil industry, and river and
harbor authorities have been involved in the planning and
will each contribute as appropriate in the cleanup
operation.
OIL AT SEA
In an earlier paper1, one of the authors reviewed the
United Kingdom plans for dealing with beach pollution and
was able at that time to mention the role of the Board of
Trade under the Agreement for Cooperation in dealing with
North Sea oil spills (the "Hamburg" Agreement). More
details of those plans have been publicized^ since that date.
They provide for the setting up at thirty ports around the
British Isles of centres with equipment to disperse oil slicks
and for the use at short notice of sea-going tugs (and, in
some areas, fishing patrol vessels) to employ the equipment.
Close liaison between the oil industry, through the U.K.
Chamber of Shipping (Tanker Section) and through the
Institute of Petroleum, with Board of Trade headquarters
and with the nine regional officers responsible for the
program in their own geographical areas ensures that
497
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498 OIL SPILL CLEANUP
industry expertise and materials are available and are fully
integrated into the overall contingency plans.
Of course, individual oil companies also have detailed
plans for dealing with marine emergencies, and these
include possible oil spill incidents. Esso Petroleum Co. Ltd.
has had such a plan for some years. It has been tested on
several occasions in various parts of the world and found to
be effective. It provides for the immediate manning of a
command headquarters in the company's London offices
whenever an appropriate distress signal is received from a
tanker anywhere in the world. According to the
information received, detailed plans can then be actioned to
dispatch a field commander to take charge .locally of rescue,
salvage and (where necessary) oil cleanup operations.
Detailed lists of salvage equipment and of salvage and
cleanup contractors are maintained, and duplicate "pocket
packs" of information appropriate to any location can be
taken out by the field force commander. In the case of the
UJC., detailed records and card indexes are kept of all
Board of Trade and coastal local authorities and of nature
conservancy, fishery and other interests. The names of key
company personnel are also available to all other major
U.K. oil companies as well as to the central and local
government departments concerned. Still further
integration is provided within the company in that the
resources of the marine emergency program are available to
the refineries, pipeline, and marketing functions to
supplement their own plans. The full marine program is
known to, and available for the assistance of, any other
affiliate of Standard Oil Company (New Jersey)-thus
providing a measure of worldwide integration.
HARBOR ESTUARIES AND BEACHES
The integration of industry and local government
resources is particularly evident in the cooperative programs
for dealing with oil spills at major oil ports. The Milford
Haven plans, in which the Conservancy Board carries out
cleanup in the harbor and subsequently bills the
appropriate oil installation when a spill can be ascribed to
one company's operations, has been in operation for some
years.3 The South Coast Early Warning System was set up
as a result of joint discussions between local government
and industry to ensure prompt reporting of oil slicks in the
busy shipping lanes of the English Channel/* A somewhat
similar plan has been introduced recently on the Humber
estuary—which is fast becoming another major oil port.
This is the result of joint industry/government discussions,
first at national level and more recently at local level.5 The
Thames estuary and Clyde River (Glasgow) each have
detailed emergency plans as the result of joint river
authority/industry initiative.
The beach pollution plan resulted from the initiative
taken by the Institute of Petroleum in 1966.
Recommendations made by a joint committee consisting of
representatives from central and local government and the
institute were accepted by the then Minister of Housing &
Local Government. In consequence each coastal county
appointed an Oil Pollution Officer responsible for preparing
detailed programs to deal with oil, to liaise with adjacent
counties, with local oil industry installations, and with
subordinate local authorities. A full exchange between
government and oil companies has ensured that the
personnel from each have the day and night telephone
numbers of members from the other partners, while field
exercises and demonstrations have ensured a knowledge of
the equipment and procedures used in oil cleanup.
INLAND SPILLS
Discussion at two recent joint conferences^,?
highlighted the concern of a number of people in the U.K.
that while plans existed for oil spills at sea and for oil
contamination of beaches, no cooperative integrated
program existed for inland spills. Individual oil companies
had made arrangements to handle incidents involving their
own facilities or even those of customers associated with
them. These arrangements also have formed the basis for a
program of mutual assistance between oil companies
involved in pollution incidents.
Except in coastal counties, no local authorities have
previously had any clear responsibility for oil pollution.
Although river authorities (river authorities in England
and Wales and | river purification boards in Scotland) had
responsibility for fresh water resources in their respective
areas, action against oil pollution was only organized in a
limited number of areas where abstraction for domestic
purposes is on a significant scale.
Discussion of this situation by the joint Oil and Water
Industry Working Group—set up on the initiative of the
Institute of Petroleum in 1964-has resulted in a proposal
that river authorities should be responsible for detailed
programs for their respective areas. A subcommittee of the
working group, consisting of representatives from central
government, the river authorities and the Institute of
Petroleum, has drawn up recommendations on these lines.
Oil spill incidents are to be reported direct to the river
authority concerned by owners of installations or others
who have established contacts with the authority. Members
of the public (and those in doubt as to the whereabouts of
the river authority) are invited to use normal police
communication channels as for any other unusual incident.
.The river authority in turn will notify all downstream
interests and in particular water abstraction, harbor
authorities, drainage and sewage bodies likely to be affected
by the incident. River authorities will establish stocks of
necessary equipment and materials needed to deal with
incidents and organize field exercises.
In drawing up their plans the river authorities will be
invited to liaise with county and other local authorities and
with local oil company installations. In this way the
existing plans of coastal authorities and the oil companies
wfll be integrated with those of the river authorities and the
unnecessary duplication of equipment and materials
avoided.
Overall coordination within H.M. Government by a
Minister of State for the Environment ensures a large
measure of overall integration for these plans covering
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INTEGRATED PROGRAM 499
respectively the treatment of pollution at sea, in the various
major oil ports, on the beaches, and inland. Full
cooperation between the oil industry and the various local
and central government departments in drawing up these
administrative plans has led to full discussions of practical
methods of oil spill cleanup**.
These discussions revealed the limitations of individual
cleanup methods and highlighted the importance of an
integrated approach. Subsequent sections of this paper deal
with the concept of integration as applied to the physical
cleanup of oil spills.
Integrated Clean-up
The physical cleanup of oil spills on water surfaces is a
far from simple operation. The search for a single universal
method, capable of dealing with all types of oil, in any
quantity and thickness and in all weather conditions, has
proved unsuccessful. In the course of this search, many
techniques have come to be branded as inadequate because
they cannot be effectively applied outside a limited range
of conditions.
LIMITATIONS OF INDIVIDUAL METHODS
Booms will contain oil slicks, within certain limitations
of wind, waves and currents, but they cannot go on
collecting more and more oil indefinitely. Many booms
have been strung across harbors and bays in an attempt to
prevent oil being washed ashore on the tide. These arrest
some oil, but as more oil collects and the depth builds up
they inevitably fail.
Suction nozzles work efficiently when used on thick
oil, but their operation is upset by waves. When used on
thin or patchy oil slicks, they collect a disproportionately
large amount of water, so that huge storage and separation
facilities become necessary.
Weir skimmers are intended to allow the surface layer
of oil to flow by gravity into a container from which it can
be removed. They work admirably on thick oil, provided
the waves and current are small. However, like suction
nozzles, they also collect water in large quantities if the oil
is thin or the waves are large.
The main problem with absorbents is the difficulty of
distributing them over a slick and of collecting and
removing them from a large area of water surface. Unless
the absorbent is reusable, large amounts are required.
Typically three times the volume of oil spilled. This leads to
storage, transportation and disposal problems and
considerable expense.
Gelling agents present the same problems of contacting
the oil and removal of the gell as are posed by absorbents.
Sinking agents are only permissible in certain areas and are
expensive for use on thin slicks. Dispersants are prohibited
in many locations, whilst destruction by burning is only
possible for thick oil slicks in fireproof or expendable
surroundings.
Each category of these cleanup methods has had its
champions. Each has tended to be examined in isolation.
Thus, there have been trials on booms, studies on skimmers,
and tests on absorbents. Nevertheless, no one method is
individually suited to all types, sizes, and circumstances of
oil spill. Effective- cleanup of any particular spill can be
obtained, however, by using a combination of these
methods.'The ideal combination is one in which each part
complements and assists the other parts, in other words-an
integrated combination. The practice of specializing in
a certain category of cleanup methods has tended to divert
attention from the much more valuable integrated
approach.
Suction removal system
Oil slick
Oil _
drum
W7T/
Weights
r*~i
f Fiied boom
Flow-
Fixed booms
Oil pumped from
fixed-weir skimmer
into tonk
Oil removed by
absorbents onto
plastic sheets
Figure 1: Simple fixed-weir Skimmer Being Used with an Overflow
Dam.
THE INTEGRATED APPROACH
The philosophy of integration can be illustrated by
examining the interdependence of booms and floating
skimmers. A boom can be used to contain a certain amount
of oil, but fails if the oil is allowed to build up; the
concentrated oil layer must be continuously removed to
allow the boom to go on working satisfactorily. A floating
skimmer operates best on a thick oil layer in calm
conditions. Used in conjunction, these two cleanup devices
assist each other and form an effective solution in
circumstances where each would fail if applied on its own.
The boom can be used to guide the collected oil to the
skimmer and so avoid the necessity of relocating the
skimmer as it clears oil from its immediate vicinity.
Similarly, the spreading and collection problems
presented by absorbents are minimized if their use is
restricted to oil confined by a boom. By limiting the use of
absorbents to slicks which are too thin for efficient
mechanical removal, the volume of absorbent required is
reduced, thus lowering the cost and simplifying the
transportation and disposal operations.
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500 OIL SPILL CLEANUP
Figure 2: Boom Held in two smooth curves by Parachute-Type Moor-
ing SystemW.
Thus, an integrated operation is one in which
individual methods are combined in such a way that they
are mutually beneficial. Moreover, in an integrated
cleanup, each part is operated so as to require the
minimum total effort. Nonintegrated combinations often
merely transfer the problem from one area to another
where it may be-more difficult to deal with; for example,
the large-scale use of absorbents on thick slicks solves a
removal problem at the expense of a disposal problem.
The many possible variations of location, waves, water
current, amount and type of oil, etc, make each spill '
unique. Even different parts of the same spill may warrant
different treatments. It is therefore necessary to be
prepared with a range of cleanup methods so that the
optimum techniques can be selected for combination into
an integrated operation which is suited to the particular
spill to be dealt with. Given this flexibility of both
equipment and method of use, integrated cleanup
operations can be used under a wide variety of conditions,
both at sea and on inland water surfaces.
Flow
Attlliory
Oil pu«Hd from floating
skimmer inM tank
Oil rtimwd by
Figure[3^AuxiliaiyBoom?and Bank|Sealing AnangementsjUsing Extra
Sections of Boom.
INTEGRATED CLEAN-UP OPERATIONS
The basic principle of the integrated operation is to
recover as much oil as possible in a form in which it can
easily be disposed of. This normally entails confinement
and mechanical recovery of the major portion of the spill
for subsequent re-refining or from combustion in such a
way as to minimize air pollution. The remaining oil can
then be attacked with absorbents and, after retrieval,
burned or disposed of in a safe area. In some circumstances,
dispersing or sinking may be the answer for oil which
cannot be recovered mechanically; in severe sea conditions,
this may apply to all the oil.
An integrated cleanup operation involves confinement,
removal, storage, transportation, and disposal. The major
part of the operation, and the most difficult, is the
integration of confinement and removal techniques so that
they retrieve oil and oil-soaked absorbents in a form which
minimizes other problems. It is on this aspect of integration
that the examples given later concentrate.
The following sections describe, with practical details
where these appear not to be generally available elsewhere,
how integrated cleanup operations can be carried out on a
variety of water surfaces, from inland streams to estuaries
and the sea.
Streams
Containment and removal techniques require a calm
stretch of water to allow the oil to separate out onto the
surface. The basic techniques for oil removal are useless on
fast-flowing shallow streams. If suitable quiescent
conditions do not occur naturally, a deep slow-moving area
of water can be created by using dams of sandbags, timber,
or earth. The oil thus contained can then be removed using
suction nozzles,skimmers,or absorbents as appropriate.
If a dam is required, it should be suituated at an
accessible point where there are high banks. It must be well
keyed into the banks and buttressed to support the oil and
water pressure.
Oil is retained by an underflow dam so long as the
water level is kept below the lip of the dam. There are
several ways of arranging this. The water can be released
from below the oil layer through pipes incorporated low
down during the formation of earth or sandbag dams.
Timber dams can be constructed so that planks can be
moved up and down to form adjustable sluices.
Small water flow rates can be released by syphons or,
preferably, by pumps. Pumping has the advantage that the
water offtake can be positioned away from the base of the
dam and in the deepest part of the water. Consequently,
pumping is less likely to disturb the surface layer and
entrain oil. It is also more controllable. The water intake
should be fitted with a large strainer to prevent entrainment
of solids and also to reduce water turbulence.
Care is needed with underflow dams to prevent
flooding upstream, to prevent the dam overflowing, and to
prevent oil escaping with the released water. The last is
caused by insufficient rate of oil removal and/or
insufficient depth for the rate at which the water is being
released.
The problems associated with the control of the water
release from underflow dams can be avoided by using an
overflow dam. A separate barrier across the pool arrests the
surface layer of oil whilst the water is released by
overflowing the top of the dam. This arrangement can be
used with larger water flow rates than are practicable for
underflow dams and is less prone to disruption by changes
in the water flow rates.
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INTEGRATED PROGRAM 501
A fixed boom, made from timber planks, provides a
convenient barrier for use with an overflow dam. This type
of boom requires a constant water level, low water flow
rate and a calm surface, which are just the conditions
provided by the overflow dam.
The. fixed boom should be placed at an angle of about
45° across the waterway. This decreases the effective water
velocity beneath the barrier and also concentrates the oil at
the bank. Arrangements can therefore be made to bring the
oil to the bank with the better access. In addition, the
removal point should be located where the water current is
at a minimum.
Whenever possible, an integrated cleanup system will
make use of local conditions to assist the operation. For
instance, the wind may tend to concentrate the oil against
one bank in preference to the other. Ah1 such factors should
be considered, in addition to questions of accessability,
when deciding to which bank to angle the boom.
The necessary boom length will be approximately 1H
times the width of the watercourse. The ends of the planks
are buried in the banks of the waterway to provide an
effective seal, and stakes are driven into the stream bed and
used as additional supports on the downstream side of the
boom as required. Any protrusions on the upstream side of
the boom will cause pockets which trap the oil and also
form points at which turbulence is likely to be set up at
high water flows. These should be avoided because they will
result in oil being drawn beneath the boom.
As emergency containment arrangements are rarely
perfect, a series of dams or booms is usually required. The
majority of the ofl will be removed at the upstream ones,
while the downstream ones are used to capture any oil
which escapes. Different cleanup methods are usually
required for removing the different thicknesses of oil
behind the various booms.
Oil must be continually removed from the angle
between the downstream end of the boom and the bank. It
is essential that a watertight seal between the boom and
bank is maintained at this point. If mechanical removal
methods are employed, sufficient water depth must be
available.
Mechanical recovery processes inevitably entrain some
water with the oil. Transport requirements can be reduced
by employing, a temporary storage tank as a separator and
removing some of the collected water.
Weir skimmers provide the most generally suitable
means of recovering oil. They are generally slower than
suction nozzles but they collect a higher proportion of ofl
when used on thin oil slicks. Suction nozzles can be used
where the water depth is insufficient for weir skimmers.
Fixed-weir skimmers should only be used in quiet
waters of constant depth. The conditions provided by
overflow dams are thus ideal for a fixed-weir skimmer.
Figure 1 illustrates a simple fixed-weir skimmer being used
in conjunction with an overflow dam. The skimmer,
constructed from an open oil drum, is supported so that the
riiri is just below the surface. The suction hose inlet is
positioned near the top of the drum and weights are used as
an added precaution against the drum's floating. The dpjrn
can of course be cut down to suit shallower waters.
The recovered oil and: water mixture is pumped into a
portable storage tank which allows further separation to
take place before the oil is transported away.
Small quantities of ofl, in slicks which are too thin for
efficient removal by skimmers, can conveniently be
removed by absorbents. Thus, absorbents are used on the
minor amounts of oil escaping to downstream confinement
arrangements, and also at the upstream boom after the
skimmers have reduced the oil to a thin layer.
In use, the absorbent is thrown or spread out onto the
ofl surface so that it collects as a mat or pile against the
boom. Some stirring is usually required to enable fresh
absorbent to be presented to the advancing ofl. The
oil-saturated absorbent is then removed and renewed.
Because the ofl is confined to a small area by the
boom, spreading and retrieval of the absorbent is simplified.
A wide variety of materials has been used as
absorbents. The most popular, and the ones which have had
most success, are straw, polyurethane foam, and various
commerical powders. Foam and powder absorbents are
preferred for light oils. Straw is better for picking up
viscous oils.
On small streams contaminated with minor amounts of
ofl, a dam can be constructed of straw bales. The intention
in this case is not so much to raise the upstream waterlevel
but more to present a sufficient area of dam face to allow
the water to filer through it. Most of the ofl wfll be
absorbed by the straw. Strawbale dams should be
duplicated and also be replaced before becoming saturated
with ofl. Some ofl release can be expected when a straw
bale is removed from the water. To prevent its escape, and
also to prevent a sudden release of water, a third
replacement dam should be constructed downstream before
removal of the upstream one.
Thus, containment and removal of ofl on stress may
well require an integrated combination of overflow or
underflow dams, fixed booms, skimmers, absorbents, and
strawbale dams.
Canals
On navigation canals, and similar still or very slowly
moving waterways, the main movement of ofl wfll be by
wind action. Under these conditions only a lightweight
boom is required to contain the ofl for removal by
skimmers or absorbents.
A floating boom of the inflatable type can be
positioned at an angle to the waterway to allow the wind to
concentrate the ofl at one bank.
The depth of the canal may make it difficult to set up
a fixed-weir skimmer. Floating-weir skimmers can be used
in which the weir is supported just below the surface by
floats. The depth of rim immersion can be adjusted, with
some difficulty, either by movement of the floats relative
to the weir or by adding ballast to the floats.
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502 OIL SPILL CLEANUP
Absorbents are conveniently used to remove the thin
oil slicks left after mechanical removal and for oil removal
at secondary booms where these are employed.
The relatively small amount of absorbent used in these
operations can be burned on site as a pile, or, with less
smoke, in a simple incinerator. Alternatively it can be
transported to a safe dumping area.
In this case, then, the confinement and removal part of
the integrated operation involves floating booms, skimmers
and absorbents, each assisting one another and each being
> applied in the most effective way.
Rivers
The same basic approach of confinement by booms,
mechanical removal by skimmers, and "polishing" with
absorbents is applicable on rivers having a sufficiently calm
area of water for separation of the oil and water phases.
Transportability, lightness, and ease of positioning are
essential requirements for an emergency floating boom, on
most inland waterways. Flexible booms with inflatable
buoyancy chambers are suitable for this purpose. Some
lightweight .types, suitable for use on small slow rivers, are
cheap enough to be regarded as disposable and this obviates
any problems of cleaning them afterwards. Such booms are
preferably stocked in short lengths which can be joined
together so that they can be applied to a variety of widths
of waterway. Stronger versions are appropriate for wide
rivers with water currents above Vi knot. Hence, flexibility
is desirable in the selection of equipment stocks, so that the
optimum boom for the particular circumstances of a spill
can be used in the integrated cleanup operation.
Work by Newman and Macbeth? has shown that both
the design of booms and their method of use are important
to their effectiveness. In brief, the boom should have a
smooth profile and be moored at frequent intervals from
the bottom of the skirt or fin, using mooring ropes with a
minimum length of 5 times the water depth.
The selection of the site for a boom is governed by the
same conditions as were outlined for streams. In other
words, a smooth undisturbed stretch of river is required,
with good access, a low water velocity near the banks, and
sufficient depth to operate oil removal equipment. The
boom should be positioned where the current is at a
minimum. It is more effective to boom at a wide slow
position than a narrow fast stretch of water.
The boom is best deployed in two smooth curves from
the point of maximum velocity (usually the center of the
river) to both banks; as illustrated in Figure 2. This
arrangement directs the surface flow of oil to the sides of
the river where the current is slower. Of course, this double
boom system requires oil to be removed from both banks.
The faster the flow of water, the more the boom
should be angled. However, the more acute the angle the
greater is the length of boom required. Fast rivers, above
about 2 knots, require an unrealistic length of boom. The
boom should be a minimum of 2 river-widths, and 3
river-widths for currents above 1 knot. For water currents
below % knot, one continuous boom can be employed at an
angle from one bank to the other, so allowing oil removal
operations to be confined to one bank.
As usual, the inshore end of the boom must make an
effective seal with the bank. This is usually easier to arrange
under emergency conditions if flexible booms are used. A
seal can often conveniently be formed by attaching an extra
length of boom to the moored end and positioning this
along the bank upstream of the boom. The resulting pocket
collects the oil ready for removal.
Oil removal operations, particularly where absorbents
are used, may cause some oil to escape beneath the boom.
This can be recaptured by a small addition boom deploying
as shown in Figure 3. Once again the bank can be
protected, and an effective seal ensured, by employing an
extra length of boom along the bank. This arrangement is
also recommended for tidal conditions where the normal
sealing methods are complicated by the rise and fall of the
boom. Booms which have joints which enable three sections
to be connected together at the same point are an
advantage in these situations.
Oil removal should be by skimmers or absorbents as
appropriate to the thickness of oil collected.
The operation of floating-weir skimmers is assisted and
simplified by being located in the sheltered area near the
bank. This type of skimmer works satisfactorily in long
swells but collects large amounts of water when used in
choppy waves.
The efficiency of a boom is improved by keeping the
front edge of the oil slick at a distance. This can
conveniently be achieved by floating a mat of straw along
the upstream edge of the boom. Foam chippings or a
powdered absorbent can then be used to absorb the oil at
the upstream edge of the straw mat.
'Some oil will always leak under a boom. Major
amounts will escape if the oil has a high specified gravity or
the water flows faster than about 2 knots. When sufficient
boom is available, the complete layout should be duplicated
downstream.
On fast flowing rivers another form of integrated
operation is appropriate.
When river currents exceed about 2 knots, booms lose
their effectiveness because the oil is swept underneath
them. In theory, this can be overcome in two ways: by
setting the boom at a more acute angle, and/or by
increasing the buoyancy of the oil. The first of these, as has
already been mentioned, may require an unrealistic length
of boom. The second can be achieved by contacting the oil
with a low density absorbent so that the resulting
combination floats better than the oil alone.
In use, the absorbent in the form of foam chips or a
commercial powder is spread across the surface of the river,
from the bank by means of air or water educators, or from
a bridge. In the latter case the absorbent is tipped into a
hopper which is connected to the water surface by a
flexible chute. This arrangement prevents the absorbent
being blown away. The object is to continuously scatter
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INTEGRATED PROGRAM 503
absorbent onto the passing ofl. However, this necessitates
an excess of absorbent and hence is expensive.
The oil-saturated absorbent is diverted to the bank
downstream by a series of angled booms. Large suction
nozzles can be used for removing the absorbent but it must
be remembered that some mineral-based powders are
abrasive to pumps.
The use of absorbents in this way is inefficient and
expensive. In some circumstances, however, this solution
may be the only alternative to allowing the oil to travel a
considerable distance downstream before reaching a calm
stretch of water on which other, more efficient, operations
can be employed.
On rivers, therefore, integrated operations involve
booms, skimmers, and absorbents used in various ways
depending upon the circumstances.
Lakes
Lakes often provide the ideal conditions of calm
slow-moving water which allow the oil to be easily confined
by booms for removal by either mechanical skimmers or
absorbents.
Oil movement is mainly by wind action which will tend
to concentrate it at one shore or in a bay. A light
floating-boom can be deployed to hold the oil for removal
in case the wind alters direction. Oil on a river flowing into a
lake should be boomed as close to the entrance as possible.
The boom should be positioned on the lake at an angle to
the residual river current so as to direct the surface water to
a slower moving area. The boom should enclose the
minimum area consistent with not exceeding a water flow
rate under the boom of 0.3m/sec.
Removal can be by nozzles, skimmers or absorbents as
appropriate to the concentrated slick thickness.
Booms can also be used to "sweep" large surfaces of
still water. The essential requirement for this operation is
that it is done VERY SLOWLY. The boom should be
moved at not more than 10 m/minute. Where small
quantities of oil are involved absorbent booms can be used
to both sweep and remove the ofl in one operation.
Polyurethane foam chips contained in a netting tube make
a very effective absorbent boom for low viscosity oils.
Viscous oils can be absorbed by straw. A simple straw
boom can be formed from bales linked together on a wire
rope. The bales should have the normal binding replaced
with metal strapping. Straw bale booms can be used as an
alternative to impervious floating booms in currents up to
about 0.3 m/sec. However, they will require replacement as
they become waterlogged or saturated with oil.
Ice on pools and lakes presents special difficulties for
oil clean-up operations. Oil on a river entering a frozen lake
generally goes beneath the ice layer. Channels can be
smashed in thin ice to install floating booms. Where thick
ice is involved (above 10 cm) booms are best maneuvered
into a submerged position through holes cut in the ice or
from the clear area near an inlet. Fence type booms are
unsuitable for operations beneath ice; a flexible circular
flotation chamber, without upward projections, is
preferred. In some circumstances it is easier to blow up an
inflatable boom after deploying it.
Holes can be cut in the ice upstream of the boom for
recovering oil by skimmers. Floating ice tends to interfere
with the operation of'weir skimmers which should be
protected by a wire netting grid.
These examples again illustrate the flexibility, both in
equipment and method of use, which is desirable for
effective integrated cleanup operations.
Estuaries and the Sea
The same basic methods of confinement and of
recovering as much ofl as possible by mechanical means
which were described for rivers apply to estauries. Waves
are usually the limiting factor in cleanup operations in
estuaries, and even more so in the open sea.
Heavy-tduty booms with increased freeboard to
prevent over-topping by waves will be appropriate. Where
booms are towed by boats, the relative movement of boom
and water should be kept low to minimise the risk of ofl
being swept underneath the boom. To prevent it building
up, the oil must be removed continuously.
Where permitted, dispersants may be used to
contribute to a cleanup operation. Considerable success has
been achieved by using dispersants when weather
conditions do not permit confinement and removal
methods to be used. The same waves which cause booms
and skimmers to fail aid the agitation needed by
dispersants.
The best results are obtained by integrating the
spraying and agitation into one operation, such as that
developed by the UJC. Warren Spring Laboratories.10 In
this system, mixing is provided by surface breaker agitators
towed by the vessel doing the spraying. Dispersing is
applicable to both thin and thick ofl slicks and can be
carried out in most weather conditions. However, it should
only be used on large bodies of moving water and with the
permission of the relevant authorities.
Sea conditions undoubtedly pose the most difficult
circumstances for ofl recovery. Even so, the integrated
approach is still applicable.
SUMMARY
Effective cleanup encompasses good administration,
sound contingency planning, and appropriate selection of
methods and equipment, combined into an integrated
program.
Action becomes most effective when all the
organizations involved have combined their efforts in
setting up appropriate action groups and have made joint
contingency plans which allow for a flexible combination
of practical methods.
The administrational arrangements described in this
paper illustrate what has been achieved in the United
Kingdom. These are not the only possible arrangements,
-------
504 OIL SPILL CLEANUP
nor are the practical methods described the only ones for
cleanup oil spills on water. These practical methods are,
however, operations which have succeeded in practice,
which use simple equipment, and which minimise both the
total effort and the expense required. They achieve this
because they are integrated operations.
Just as there is no single cleanup method, no matter
how sophisticated, which does not benefit from being
combined into an integrated operation, so there is no
individual body which cannot benefit from joint planning.
The concept of integration is applicable to all forms,
sizes and circumstances of oil spill, not only on water
surfaces but also on the soil, in subsoils and in
groundwaters. In administration and in practice, integration
provides the key to successful oil spill cleanup.
REFERENCES
(1) .H. Jagger. API/FWPCA "Joint Conference on
Prevention and Control of Oil Spills" New York, 15th-17th
December 1969.
(2) Board of Trade Supplement. September 9th 1970.
(3) Appendix 5 ) Minutes of Evidence, Select Committee
on Science & Technology. HMSO London, September
1967.
(4) Appendix 3)
(5) Lloyds List-February, 1971.
(6) Institute of Water Pollution Control: "Seminar on
Water Pollution by Oil, Aviemore, Scotland, 4th-8th May,
1970",1971.
(7) Institute of Petroleum: Symposium on the Ecological
Effects of Oil Pollution on Littoral Communities, London,
30th November-lst December 1970. J. Inst. Petrol. - in
press.
(8) "Workshop on Oil Spill Clean-up" Institute of
Petroleum, London, 16th October 1970. J. Inst. Petrol.
Vol. 57, January 1971.
(9) Newman, D. E., and Macbeth, N.I. "The Use of Booms
as Barriers to Oil Pollution in Tidal Estuaries and Sheltered
Waters." Institute of Water Pollution Control: "Seminar on
Water Pollution by Oil, Aviemore, Scotland 4th-8th May,
1970," 1971.
(10) "Instructions for using WSL Dispersant Spraying
Equipment" Ministry of Technology, Warren Spring
Laboratory, Stevenage, Hertfordshire, UK. 1970.
-------
EVALUATION OF SELECTED EARTHMOVING
EQUIPMENT FOR THE RESTORATION OF
OIL-CONTAMINATED BEACHES
James D. Sartor and Carl R. Foget
URS Research Company
SanMateo, California
ABSTRACT
Research studies were conducted to evaluate the use of
selected earthmoving equipment in oil-contaminated
beach-restoration operations and to determine the cost and
effectiveness of such equipment. Specifically, the objectives
were to:
Determine modifications and cost required to
improve the capacity of selected equipment.
Develop optimum operating procedures for each
method.
Determine, through field testing, the operating
cost of each method evaluated.
These objectives were accomplished in two phases.
Phase I: reviewed procedures utilized in previous
beach-restoration operations, phis surveyed and evaluated
commercially available earthmoving equipment. Phase
II: conducted full-scale tests to demonstrate the restora-
tion procedures developed and to determine the efficiency
with which each procedure/equipment item collects
oil-contaminated material The flexibility and performance
characteristics of the equipment were tested under a variety
of beach conditions.
The oil removal effectiveness was greater than 98% for
att restoration procedures. The highest effectiveness was
achieved using the motorized grader and motorized eleva-
ting scraper working in combination. The tracked front end
loaders were least effective. On beaches possessing low
shear strength, flotation tires or steel-belted half-tracks on
the motorized grader and a non-self-propelled elevating
scraper with a tracked prime mover should be used.
Conveyor-screening systems can be effectively utilized to
had oil-contaminated material into trucks for transport to
disposal areas, separate oil-sand pellets from clean sand, and
partially separate oil-contaminated debris (Le., straw, kelp,
seaweed) from oil-contaminated sand.
The beach-restoration operations evaluated in this
study were successfully utilized in the restoration of
oil-contaminated beaches resulting from the recent San
Francisco Bay oil spill incident.
This study was conducted in fulfillment of Contract
No. 14-12-811 between The Federal Water Quality Office,
and The URS Research Company.
INTRODUCTION
BACKGROUND
An increasing hazard of contamination of the environ-
ment with oil has accompanied the worldwide growth of
the petroleum industry. Since 1954, some 8,000 offshore
wells have been drilled, with 8 resulting in oil blowouts and
17 in gas blowouts, the recent Santa Barbara Channel 1
blowout being the most serious. It has been predicted^ that
if offshore development continues to expand at the present
rate and the frequency of accidents remains the same,
3,000 to 5,000 wells will be drilled annually by 1980, and
we can expect to have a major pollution incident every
year. Additionally, supertankers of the future will carry
much more oil than that released by the rupture at Santa
Barbara and by the grounding of the Torrey Canyon3 and
the more recent collision of the Oregon Standard and
Arizona Standard in the San Francisco Bay.
The problem of beach contamination becomes severe
in the case of large accidental oil releases at sea, such as that
of the Torrey Canyon and Santa Barbara incidents. Com-
plete removal or dispersal of the released oil at sea in these
incidents was not possible, and very large oil slicks moved
505
-------
506 OIL SPILL CLEANUP
ashore, coating entire beaches up to the high-tide mark.
Where oil absorbents, such as straw, had been broadcast on
the oil slick at sea, as at Santa Barbara and in the San
Francisco Bay spill, the oil-soaked absorbent was also
deposited on the beaches, rocky shores, and riprap.
Once the oil comes ashore, serious economic and
ecological consequences may result. Oil contamination has
an obvious adverse effect on recreational uses of beaches.
Since in many situations complete removal or dispersal of
oil before it reaches the coast will be impossible, effective
beach-restoration procedures are needed. In all major spills
to date, containment of the oil spill at sea has been
ineffective-resulting in oil-contamination of shorelines.
Previous restoration methods have used excessive
amounts of labor. The choice of a restoration method
depends upon the economical and recreational value of the
area and surface conditions and topography of the shore-
line. Although various types of earthmoving, construction,
and agricultural equipment have been utilized in
beach-restoration projects, the equipment does not appear to -
have been utilized either effectively or efficiently, and little
has been done to mechanize or systematize beach cleanup
operations.
URS Research Company personnel have had extensive
experience in the development of procedures for the
decontamination of beach and land areas contaminated
with radioactive fallout 4-9 Although fallout does not have
the same physical characteristics as oil-contaminated sand
and debris, the requirements of complete removal of the
fallout particles from beach areas pose a similar problem,
ie., removal of a thin layer of surface.
During these previous studies, the processes involved
and means of improving the performance of earthmoving
equipment were investigated. Many of these findings are
applicable to the use of similar equipment for utilization in
the cleanup of oil-contaminated beaches. The possible
approaches to improving performance (and reducing cost)
of selected equipment include:
Modifications to equipment, such as addition of
baffles, blade modifications, etc.
Optimizing operational procedures, such as speed
of operation, blade angles, depth of cut
Changes in operational procedures, such as use of
conveyor-screening systems in combination with
' graders and scrapers
OBJECTIVES
The objectives of this research study were to evaluate
the use of selected earthmoving equipment in oil-contami-
nated beach-restoration operations and to determine their
cost and effectiveness in removing oil-contaminated sand
and debris. Specifically, the objectives included:
(1) Determination of modifications and cost required
to improve the capacity of the selected equipment
(2) Development of optimum operating procedures for
each method
(3) Determination of the operating cost, of each
method evaluated through field testing.
SCOPE
The method and equipment selected to restore a beach
contaminated with oil will depend upon the manner in
which the oil has been deposited onto the beach and the
type of beach contaminated. For the purpose of this study,
the principal effort was directed towards examining two
representative situations involving oil contamination:
I. Beach material uniformly contaminated with a thin
layer of oil up to the high-tide mark and/or deposits
of oil dispersed randomly over the beach surface.
Oil-deposit penetration is limited to approximately
lin.
II. Agglomerated pellets of oil-sand mixture or
oil-soaked material, such as straw and beach debris,
distributed randomly over the surface and/or mixed
into the sand
In both of the stated conditions the restoration
involves: (a) the physical pickup of the deposited oil,
oil-contaminated sand, straw, or other debris; (b) the
separation (in some cases) of the oil-contaminated debris
from clean, loose sand, and (c) the removal of the
oil-contaminated materials to a disposal site.
The surface conditions and topography of the beach
contaminated with oil will dictate the choice of equipment
to be utilized and the operating procedure to be followed.
Surface conditions can vary from a smooth, hard, sandy
surface to rocky (shingled), irregular surfaces. The topog-
raphy can range from long flat beaches to those that are
short, scalloped, steep and undulating. The principal effort
in this project was directed towards the development of
operating procedures and equipment required for the
restoration of sandy beaches.
METHOD OF APPROACH
The objectives of this research study were accom-
plished in two phases, each comprised of several tasks as
follows:
Phase I
Task I
Review existing reports on recent oil-pollution inci-
dents and other available information to determine:
(a) The magnitude of beach contamination (to esti-
mate potential material-handling load)
(b) Probable situations to be encountered (i.e., uni-
form or non-uniform oil contamination, types and
amounts of debris, etc.)
(c) Previous methods utilized in beach-restoration
operations
(d) The range of characteristics of beach sands (par-
ticle size, cohesiveness, materials, occurrence of
rock, etc.) and beaches (size, accessibility, etc.) of
the United States that may be subject to oil
contamination.
-------
EARTHMOVING EQUIPMENT
507
Task II
Review equipment performance and develop prelimi-
nary beach-restoration operations as follows:
(a) Survey commercially available equipment and
obtain information on pertinent performance
characteristics.
(b) Review and evaluate previously used beach-restora-
tion methods and identify limitations of equip-
ment utilized.
(c) Design candidate beach-restoration procedures and
identify possible limitations of equipment.
(d) Specify possible modifications to the equipment to
increase effectiveness.
Task III
Conduct preliminary evaluation tests to determine:
(a) Necessary modifications and cost of modifications
to motor-grader blades and motorized scraper
hoppers to minimize spillage
(b) Effectiveness of various screening techniques for
oil-contaminated beach material
(c) Effectiveness of pretreatment methods to facilitate
pickup of contaminated beach material.
Phase II
Task I
Conduct full-scale field tests to evaluate the operating
procedures and equipment modifications selected in Phase
I. Performance criteria measured for each procedure and
equipment combination evaluated included:
(a) Efficiency with which each procedure/equipment
collects or spills oil-contaminated material
(b) The ratio of oil to inert material in the mixture
collected
(c) The cost per unit of oil collected and unit of beach
material handled
(d) Capability of the equipment to operate under a
variety of beach conditions
(e) Performance characteristics at various speeds,
blade angles, and depths of cut
Phase I Evaluation Tests
Full-scale evaluation tests at three beach sites along the
San Mateo County (California) coastline, plus laboratory
tests utilizing scaled mock-ups were conducted during Phase
I to determine:
(a) Means of applying oil and oil-sand-straw mixture to
beach test areas
(b) Performance information for the various classes of
equipment to be utilized in the beach-restoration
operations
(c) Evaluation of conveyor-screening techniques for
the separation of oil-straw-sand mixtures from
clean sand
(d) Necessary modifications to equipment to enhance
performance for beach-restoration operations
On the basis of the analysis of previously used cleanup
methods, discussions with equipment manufacturers, and a
survey of commonly available earthmoving construction
and agricultural equipment, the following equipment was
selected for evaluation in this study:
Motorized graders
Motorized elevating scrapers
Front end loaders
Conveyor-screening systems
Figure 1; San Mateo County Coastline Test Sites
FULL-SCALE TESTS
Full-scale tests to evaluate the performance of selected
earthmoving equipment were conducted at three beach sites
along the San Mateo County coastline. The locations of
these beach sites are shown in Fig. 1. The selection of the
test sites was made after considering the following factors:
(a) accessibility, (b) slope of beach, (c) sand grain size
gradation, and (d) typicality (of recreation-type beaches).
For each site, the average slope of the beach in the
intertidal zone was determined. Sand samples were taken at
various locations in both the intertidal zone and in the
backshore area to establish the grain size gradation and the
sand classification for each test site. The grain size
gradation was determined by a standard sieve analysis, and
the sand classification followed that established by the U.S.
Department of Soil Conservation soil classification system.
A detailed description of each of the three beach test
areas follows:
Francis State Park Beach, Half Moon Bay, Cali-
fornia — can be classified as a spit and bay mouth
bar type of beach and contains a coarse to medium
sand with a median grain size of 0.54 mm in the
backshore area and 0.45 mm in the tidal zone. The
beach is loosely packed, has very soft footing, and
a tidal zone slope of 6%.
-------
508
OIL SPILL CLEANUP
Tunitas Beach, south of Half Moon Bay - is an
excellent example of a pocket beach and contains
a fine to very fine type of sand with a median
grain size of 0.25 mm in the backshore and 0.21
mm in the tidal zone. The beach is hard packed
with very firm footing and has a tidal zone slope
of 3%.
Half Moon Bay Harbor Beach, Princeton, Cali-
fornia - is located behind the breakwater of the
Half Moon Bay harbor and can be classified as a
spit and baymouth bar type of beach. The sand on
the beach is poorly graded, varying from very
coarse to very fine grain size and has a median
size of 0.82 mm in the tidal zone. The beach has
medium packed sand with medium to firm footing
and a tidal zone slope of 3%.
All three beaches are used for recreational purposes.
The Francis State Park Beach and the Princeton Beach are
public beaches and offer ready access for heavy equipment.
Tunitas Beach, a private beach, is located at the base of
steep cliffs and an access road had to be constructed by
widening an existing foot path. This was accomplished in 1
day's time with a bulldozer. These three beach test sites
provided a range of characteristics that are representative of
many beaches along the coastline of the United States.
Seventeen series of tests were conducted utilizing a
motorized grader, motorized scrapers, and front end
loaders, singly and in combination. The equipment evalu-
ated included:
Front End Loader - International Harvester Model
175B, crawler tractor, 4-in-l bucket, 2-cu-yd capacity,
120hp
The choice of make and model of equipment evaluated
was determined only by equipment availability at the time
of testing. These items, however, are representative of their
classes.
To improve the performance on sand, the motorized
grader was equipped with 23.5x25, 10-ply flotation tires on
all four driving wheels in place of the standard 13.00x24.
10-ply tires. The motorized elevating scraper was also
equipped with two optional features designed to improve
operating performance on sand. These consisted of the
following;
(a) The installation of a high-speed, low-torque motor
cartridge kit to increase the elevator speed approxi-
mately 20-29%.
(b) A transmission change consisting of a turbine and
drive gear modification to reduce the ground speed
from a maximum speed in first gear of 6 mph to
2.72 mph and a reduction in second gear high
range from 24 mph to 16.6 mph.
The operating characteristics of each piece of equip-
ment in removing the surface layer of sand was determined
at each beach test site under different beach conditions. In
several tests, oil was utilized in tidal zone areas, and in one
instance on the backshore area where oil was applied to the
surface by spilling a container of water and oil over the test
site. In several tests the test area was covered with straw or
a test area was selected that was covered with kelp and
other debris.
. * V _ - -J --
•• ,.« ^
Figure 2: Motorized Grader
Motorized Grader - (Fig. 2) Caterpillar Model 12,
rubber tired, 12-ft blade, 115 hp
Motorized Elevating Scraper - (Fig. 3) International
Harvester Model E-200, rubber tired, 9-cu-yd capacity,
135 hp, two-wheel drive
Motorized Scraper - (Fig. 4) Caterpillar Model 10,
rubber tired, 12-cu-yd capacity, 120 hp, four-wheel
drive
Front End Loader - Caterpillar Model 955, crawler
tractor, 4-in-l bucket, 1-3/4-cu-yd capacity, 115 hp
Figure 3: Motorized Elevating Scraper
The beach-restoration procedures evaluated for each
piece of equipment and combination of equipment in the
Phase I tests are listed in Table 1. The basic test procedure
was to operate the equipment on a 100-by 30-ft test area
and to time and photograph the operations and obtain
appropriate measurements, including width of cut, depth of
cut, size of windrows and visual observations of effective-
ness (i.e., amount of spillage). Each piece of candidate
-------
EARTHMOVING EQUIPMENT 5Q9
equipment was tested individually to determine its opera-
ting characteristics and performance in removing a thin
surface layer of sand under various beach conditions. The
motorized grader was then operated in combination with
the elevator scraper and the front end loader to determine
the effectiveness of combined operations.
During both the individual tests and the combined
equipment tests, the various pieces of heavy equipment
were operated at different speeds, depths of cut, and blade
angles to determine the optimum operating characteristics
for equipment performance on a sandy beach. Finally,
several tests were run to determine cycle time (i.e., a
complete loading cycle, which includes loading, hauling,
dumping, and return to loading position). In some of these
tests, longer test areas were used to approximate actual
conditions (e.g., the scraper will normally operate in one
direction and continue loading until its capacity is reached
instead of making short, 100-ft passes).
Figure 4: Motorized Scraper
A.
C.
D.
PROCEDURES
Surface layer of beach material
pushed into windrows by a motorized
grader for pickup and removal by a
motorized elevating scraper.
pushed into windrows by a motorized
grader for pickup by front end
loaders and removal bv trucks .
Surface layer of beach material
picked up by a front end loader
and removal by trucks .
Surface layer of beach material
EQl' I PMEST
Motorized Grader
Motorized Elevating Scraper
Front End Loader
Trucks
Front End Loader
Trucks
Motorized Elevating Scraper
One measure of efficiency is the amount of sand
removed during a beach-restoration operation. For each
operation, the volume of sand (in cubic yards) removed per
acre of beach cleaned was calculated from the data. The
results in Table 2 show that the smallest amount of material
per acre was removed with the motorized grader and
motorized elevating scraper working in combination
(Restoration Procedure A, Table 1). The motorized eleva-
ting scraper operating alone was the next best procedure.
The most inefficient arrangement utilized a front end
loader to scrape up and remove the material.
The range of values given is based on several tests. An
important parameter in calculating the total volume re-
moved is the depth of cut, and in each test an average depth
of cuty was measured. In some instances, due to the bearing
surface of the test area and topography, it was difficult for
the operator to maintain a constant depth of cut.
Another measure of efficiency is the rate (hr/acre) at
which beach areas are cleared. Table 3 presents the rate of
clearing for the various pieces of equipment evaluated and
combinations of equipment. The calculations are based on
these operations in which cycle times were taken.
The values given for each equipment item and/or
combination of items are based on equipment performing
under optimum conditions (i.e., the motorized elevating
scraper loading in first gear and hauling and returning from
the dump area in second gear: the motorized grader
operating in second gear for both forward and reverse; and
the front end loader operating in first gear for scraping and
second gear for hauling and dumping).
The calculated values are based on the haul distances
given in Table 3 for each operation. Increasing or decreasing
VOLUME OF SAND REMOVED
(Cu yd acre of beach cleaned)
Motorized Grader and
Motorized Elevating
Scraper
Motorized Elevating
Scraper
Motorized Grader and
Front End Loader
Front End Loader
Loose Sand or
Backshore Area
130-145
300-400
800-1200
Firm Hard-
Packed Beach
70-100
200-250
300-325
Firm Beach With
Straw Applied @
100 Bales. Acre
180-200
Table 2: Sand Removal During Various Beach Restoration
Operations
CLEARANCE RATES
(hr/acre)
HAUL DISTANCE (ft)
TO DUMP (one way)
Motorized Grader and
Motorized Elevating
Scraper
Motorieed Elevating
Scraper
Motorized Grader and
Front End Loader
Table 1: Beach Restoration Procedures Evaluated in Phase I Tests
Table 3: Acres Cleared and Hauled by Various Types and
Combinations of Equipment
-------
510 OIL SPILL CLEANUP
these distances would increase or decrease the rates
accordingly. When a motorized grader is used in combina-
tion with a motorized elevating scraper or front end loader,
the indicated rates may be increased by the use of
additional scrapers or front end loaders. The motorized
grader is capable of producing windrows continuously, and
several motorized elevating scrapers or front end loaders
can be utilized to pick up and remove the windrows.
As indicated in Table 3, the motorized grader/motor-
ized elevating scraper combination is the most efficient for
an equivalent length of haul. The least efficient is the front
end loader, working singly.
Tests were also conducted on backshore tests areas.
On the Francis State Park Beach, where very loose dry sand
was encountered, the rubber-tired equipment ( motorized
grader and motorized elevating scraper) could not operate
efficiently and in several instances became immobilized.
Only the crawler-mounted front end loader could perform.
However, as indicated in Table 2, the use of a front end
loaders is very inefficient in terms of the volume of material
removed.
Procedures for minimizing the oil contamination of
backshore areas should be instituted at the first indication
of a possible shoreline pollution event. Under normal tide
conditions, a berm or dike at the high-tide mark can
prevent oil from contaminating backshore areas. However,
as in the case of Santa Barbara, heavy winter storms can
wash oil over dikes or breakwaters onto these areas.
Phase II Demonstration Tests
Full-scale demonstration tests were conducted to
evalute the restoration procedures and equipment modifica-
tions selected in the Phase I evaluation tests. Performance
criteria measured for each procedure/equipment evaluated
included:
(a) Efficiency with which each procedure/equipment
item collected or spilled oil-contaminated material.
(b) Trie ratio of oil to inert material in the mixture
collected.
(c) The cost per unit of oil collected and unit of beach
material handled.
(d) Capability of the equipment to operate under a
variety of beach conditions.
(e) Performance characteristics at various speeds, blade
angles, and depths of cut.
RESTORATION PROCEDURES EVALUATED
The beach-restoration procedures recommended for
full-scale testing in the Phase II demonstration tests, based
on the Phase I preliminary evaluation tests, include the use
of: (a) motorized graders; (b) motorized elevating scrapers;
(c) crawler tractor-drawn elevating scraper; (d) front end
loaders; and (e) conveyor-screening systems. A total of 20
tests were conducted on test areas exhibiting the listed
beach conditions. The equipment items utilized included
those evaluated previously in the Phase I tests, and the
following additional equipment:
Front End Loader International Harvester.
Model H-80, rubber tired, 3-cu-yd capacity, 225
hp
Portable Conveyor-Screening Plant Barber
Greene, Model PS-70, 24-in. belt, 270 tons/hr
Non-Self-Propelled Elevating Scraper - Johnson
Mfg. Co., Model 80-C, rubber tired, 8-cu-yd
capacity
Mulch Spreader - Finn Mulch Spreader, Model P.
10 tons/hi
As stated previously, the choice of make and model of
equipment evaluated was determined only by equipment
availability at time of testing and were representative of
their classes.
Figure 5: Close-up of Oil Film on Test Area
Figure 6: Straw Being Dispersed on Test Area by Straw Blower
-------
EARTHMOVING EQUIPMENT 5||
•
Figure 7: Oil-Sand Pellets Distributed Over Test Area
TEST CONDITIONS AND DATA COLLECTED
The restoration procedures were evaluated for five
beach conditions:
(1) Tidal zone - contaminated with a thin film of oil
(Fig. 5)
(2) Tidal zone - contaminated with an oil-straw
mixture (Fig. 6)
(3) Tidal zone -- contaminated with randomly dis-
persed, agglomerated oil-sand pellets (Fig. 7)
(4) Backshore zone - contaminated with a thin film
of oil
(5) Backshore zone — contaminated with randomly
dispersed, agglomerated oil-sand pellets
The following measurements and data were collected
for each test series conducted.
Pre-Test Conditions
(a) Quantity of contamination agent dispersed on test
area
(b) Total area contaminated
(c) Average depth of penetration of oil
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1
1
LyL 1PMENT
EVALIATED
V. :.:..,,. EKvjt-
in- S. raptr
M«.lunzt-d EK-V3T-
int: Serai- r
Si rapiT
C :•_>*!, r Trjtljr
* i :h ti.iK- tracks
t l ont Eriii • •
Hubber tirn:
!»t; 3^ rapt-r
me S> TJpvr *1 lh
i nn St.- r a per *• i ih
• • : -•. i S 1 t-s
sami baffles
Mutori/rv
-------
512 OIL SPILL CLEANUP
TEST
NO.
E-2
(•)
BEACH DISTANCE
. CONDI- EQUIPMENT OIL CONTAHMTIOM ABBA CUT TIME VOLUME TO UNLOAD-
TION EVALUATED DISPERSED AREA COVERED CLEANED WIDTH DEPTH LENGTH OPERATION CYCLE REMOVED IMG AREA CONCENTS
• (K*l) <•» ft) (*q yd) (in.) (ft) (Bin.aec) (cu yd) (ft)
MDtorlMtJ Kl««t- 35 10 Resultant »lndrow easily picked up by motorized
int 8crai»r .ith ' «l«v.ting .craper.
sand baffle*
Coaveyor-Sc reenlaa:
Syste*
•otorlKed Ilevat- 36 30 nated. Conveyor-screcnlnc system separates 75-80%
ing Scraper with ' of *triw plcked u* fro" "nd-
•tod baffle*
Straw Blower
CouT«yor-3c retninf
System
3 Motorized Elevat- 190 292O 445 20 1-1.5 2OO 26. 3O 26.30 34 1000 Very little spillage occurred. Straw on test
in*- Scraper area eliminate* pickup of oil on tires.
Straw Blover
Conveyor-Sc reeoiBf
Syatt*
Sec Table 4
Table 5: Full Scale Demonstration Tests - Data Summary
1&91 COHOI-
NO. TIW
SqUIPMEHT OIL ttHTTAMlKAriOtl AREA
EVALUATED DISPERSED AREA COVERED CLEANED WIDTH DEPTH LENGTH __..
DISTAKE
VOLUME TO UKLQAD-
BmOVED 1HC ABEA
leu yd) (ft)
E-3 3 Ho tori zed Elevat- 190 2400 267 2O 1-1.5 120 23,15 23.15 13.5 800
1ST 20 1-1.5 75 2,41 2,41
H !».. 2 50 7,31 7,31
bowl. Conveyor-screening system very efficient
in separating oil-sand pellets frost clean sand.
F-3 3 Motorized Elevat- ISO
luf Scraper •itit
sand baffles
Coaveyor-Sc recninc
HotoriMd Elavat-
tnc Scraper v&tb
saod baffles
CoBveyor-ScreeBtni
Systea
C-3 3 Motorized Grader 160
Motorized Elcvat-
iac Scraper vltb
sand baffles
CoRwyor-Screeatnx
Syste.
C-5 5 Motorized Grader 200
Motorized Elevat-
ing Scraper «itb
saad baffles
Conveyor-Screenlnf
Systeai
20 1 100
2,27
4,45
1,31
3,25
7,12 9 750 Utj
noted in Test B-3.
4,M 3.5 BOO
Sec Table 4
Table 6: Removal of Oil-Sand Pellets - Data Summary
Equipment Operations
(a) Equipment conditions — blade angle, operating
speed, depth of cut, elevator speed
(b) Size of windrows-length, width, depth
(c) Elapsed time for each pass
(d) Elapsed time for each loading cycle
(e) Volume of material in scraper bowl
(Q Elapsed time for each unloading cycle
(g) Distance to unloading area
(h) Total cycle time
(i) Estimated amount of spillage
Post-Test Conditions
(a) Location and amount of contamination agent
remaining on test area
(b) Location and amount of debris, kelp, etc., remain-
ing on test area
Still photographs and motion pictures were taken
before, during, and after each test series to document each
operation.
-------
EARTHMOVING EQUIPMENT 5)3
^^•MH
TEST
NO.
A-l
A-l-1
Ol
D-l
E-l
F-l
F-4
G-l
G-4
H-l
H-4
(a)
(b)
BEACH
CONDI- „
TIONta)
1
1
1
1
1
1
4
1
4
1
4
See Table
Based on
RESTORATION PROCEDURE MODIFICATIONS
Combination of Motorized Grader None
and Motorized Elevating Scraper
Combination of Motorized Grader None
and Motorized Elevating Scraper
Towed Elevating Scraper None
Combination of Motorized Grader None
and Front End Loader mounted on
rubber tired tractor
Motorized Elevating Scraper None
Motorized Elevating Scraper Sand Baffles
Motorized Elevating Scraper Sand Baffles
Combination of Motorized Grader Sand Baffle's
and Motorized Elevating Scraper
Combination of Motorized Grader -Sand Baffles
and Motorized Elevating Scraper
Combination of Motorized Grader 4-1 Bucket
and Front End Loader mounted on
crawler tractor
Combination of Motorized Grader 4-1 Bucket
and Front End Loader mounted on
crawler tractor
4
500— ft distance to unloading area
VOLUME
OF SAND
REMOVED RATE
(cu yd/ (hr/
acre) acre)
483 3.85
580 2.70
228 7.14
235 5.55
596 4.00
305 1.10
443 2.70
336 1.64
394
180 21.0
236 37,0
INITIAL
OIL
LOADING
(gal/
sq yd)
0.48
0.57
0.83
0.45
0.83
0.76
0.62
0.58
0.77
0.94
OIL OIL
REMOVED RESIDUAL
(gal/ (gal/
sq yd) sq yd)
4.8 0.0013
4.7
—
17.1 0.0006
3.6 0.0002
13.1
8.2 0.001
8.8 0.0001
7.2 0.0009
21.8 0.002
19.3 0.0019
Table 7: Removal of Thin Film of Oil - Summary of Test Results
BEACH
TEST CONDI-
HO. TIONU>
B-l
B-2
E-2
RESTORATION PROCEDURE
VOLUME INITIAL
OF SAND OIL OIL OIL
MODIFICATIONS REMOVED RATE LOADING REMOVED RESIDUAL
(cu yd/ (hr/ (gal/
(gal/ (gal/
Combination of Motorized Grader Sand Baffles
and Motorized Elevating Scraper
Combination of Motorized Grader Sand Baffles
and Motorized Elevating Scraper
with straw added
acre) acre) sq yd) cu yd) sq yd)
297 2.56 0.43 7.05 0.0002
Motorized Elevating Scraper
with straw added
None
343
377
2.78
2.44
0.60
0.58
8.4
7.6
(a) See Table 4
(b) Based on 500-ft distance to unloading area
Table 8: Full Scale Demonstration Tests - Summary of Test Results
-------
514 OIL SPILL CLEANUP
TEST
NO.
G-3
G-5
F-3
F-5
E-3
(a)
(b)
(c)
BEACH
CONDI-.
TIONta)
3
5
3
5
3
RESTORATION PROCEDURE MODIFICATIONS
Combination of Motorized Grader Sand Baffles
and Motorized Elevating Scraper
Combination of Motorized Grader Sand Baffles
and Motorized Elevating Scraper
Motorized Elevating Scraper Sand Baffles
Motorized Elevating Scraper Sand Baffles
Motorized Elevating Scraper None
VOLUME
OF SAND
REMOVED RATE1 '
(cu yd/ (hr/
acre) acre)
260 2.32
76 1.64
231
345 1.75
245 4.35
INITIAL
OIL
PELLET
LOADING
(lb/
sq yd)
2.0
2.8
1.6
1.5
0.7
OIL
PELLETS
REMOVED
(lb/
cu yd)
36.5
175
33
21.1
14.1
OIL
PELLET
RESIDUAL
(lb/
sqyd)(c)
O
0
0.045
0.009
0.015
See Table 4
Based on 1500-ft distance to unloading area
A value of
0 indicates no oil-sand pellets remained on test
area
Table 9: Removal of Thin Film of Oil - Summary of Test Results
TEST RESULTS
The major observations and data collected during the
Phase II testing are given in Tables 4 through 6. Included
are detailed data on each test, including quantity of oil
contamination; time of operation; area cleaned; depth,
width and length of cut; material removed; and comments
on the performance of the equipment. The principal test
variables during the Phase II testing were beach conditions,
equipment modifications, and equipment combinations.
Specific equipment variables, such as blade angle and
operating speeds, were evaluated during the Phase I testing,
and the optimum settings determined therein were utilized
in the Phase II test program. The depth of cut was
dependent upon the depth of ofl penetration in each test.
Measures of effectiveness for each restoration pro-
cedure in terms of the total volume of sand removed per
acre of beach cleaned, the cleaning rate, the ratio of oil
removed to the volume of sand removed, and the residual
amount of oil remaining on each test area after cleaning are
presented in Tables 7 through 9. The total area cleaned in
each test was usually greater than the area contaminated
with ofl Thus, to allow for comparisons between restora-
tion procedures, the total cleared area was assumed to be
uniformly contaminated with ofl at the initial ofl loadings
given in Tables 7 through 9. The initial ofl loadings utilized
would approximate 10,000 gal of ofl deposited over 1 mile
of beach, 30 ft wide.
The interaction between the ofl loadings and the
various equipment types evaluated was minimal, Le., the
presence of the film of ofl on the beach surface did not
affect the ability of the equipment to pick up, cut, or
transport the contaminated beach material. The mixing
action that occurred in the cutting and/or pickup of a thin
film of ofl and the underlying clean sand results in a
uniform oil-sand mixture. Under these conditions, it is not
possible to separate oil-contaminated sand from clean sand
by screening.
The experience of the equipment operator to properly
operate earthmoving equipment under the beach conditions
encountered in the Phase II tests was found to have an
important influence on the volume of material removed
from each test area. The motorized grader operator for Test
A-l, A-l-1, G-l, and G-4, which were conducted in
combination with the motorized elevating scraper, experi-
enced difficulty in maintaining a constant depth of cut, and
in most instances cut deeper than required, thus forming
large windrows. This resulted in removal of an excessive
amount of material from the test area.
In contrast, the experienced motorized grader operator
utilized during Test D-l and H-l, conducted in combination
with front end loaders, maintained a constant 1/2- to 1-in
cut, thereby forming smaller windrows and minimizing the
volume of material removed.
The average depth of ofl penetration on most of the
tests was limited to 1/2 to 1 in. However, varying oil
penetration was noted on most test area. Its extent
depended upon the nature of the beach test area and the
length of the interval between loading and removal. Oil
penetration greater than 1 in. usually occurred in small
areas (2 to 3 sq ft) where coarser sand had concentrated. In
some instances, removal of these lenses of oil necessitated
additional cleanup passes; however, they could have been
easily removed .manually.
In Test E-2, the test area was a hard-packed tidal flat
and ofl remained pooled on the surface with little to no
"penetration. In Test B-2, in an area in the upper tidal zone,
ofl remained on the test area 2 to 3 hours prior to removal;
-------
EARTHMOYING EQUIPMENT 515
during this time oil penetrated 2 to 3 in., thus requiring
additional cleanup passes.
REMOVAL EFFECTIVENESS
The oil removal effectiveness was determined by
manually removing all of the visible ofl remaining on the
test area subsequent to the completion of a restoration
procedure and stripping the oil from the oil-sand mixture.
The residual amount of oil for each test is given in Tables 7
through 9. The ofl removal effectiveness was greater than
98% for all restoration procedures. The highest effective-
ness was achieved through the use of the motorized grader
and motorized elevating scraper working in combination.
the lowesteffectiveness was obtained with the tracked front
end loader.
The removal effectiveness for oil-sand pellets was also
greater than 98%, The residual oil-sand pellets on Tests F-3,
F-5, and E-3 resulted from spillage following raising of the
filled bowl on the motorized elevating scraper at the end of
the test area.
CLEANING RATE
Table 10 presents cleaning rates for each restoration
procedure evaluated on both tidal zone areas and backshore
area. The rates presented for the motorized grader and
motorized elevating scraper were obtained from the
full-scale demonstration tests, where the times of operation
were longer, thus more realistic than the operating times
from the small-scale tests. A major factor affecting the
cleaning rate is the distance the material picked up has to
be hauled to an unloading area. During the Phase II tests,
distance to unloading areas varied from 50 to 2450 ft. To
allow comparisons of cleaning rates, the rate data given in
Tables 4 through 6 were normalized to a 500-ft, one-way
hauling distance for all tests.
As indicated in Table 10, there was no significant
difference in cleaning rates between the motorized elevating
scraper working singly or in combination with the motor-
feed grader. This is in contrast to the results of Phase I,
where the motorized elevating scraper was slower when
working singly. This disparity was due to the manner in
which the motorized grader was operated. In Phase I, in
which no ofl was used, the motorized grader made 1/2-in.
cuts, thus forming windrows that were easily picked up by
the motorized elevating scraper. In Phase II, the motorized
grader maintained a depth of cut at depth of ofl penetra-
tion, which in most instances was 1 to 1-1/2 in., thus
forming larger windrows which increased the loading time
for the motorized elevating scraper.
Under ofl contamination conditions where ofl penetra-
tion is greater than 1 in., it is recommended that the
motorized elevating scraper be used singly. In instances
where ofl penetration is limited to 1/2 in., such as on a
firmly packed tidal flat, the use of a motorized grader and
motorized, elevating scraping working in combination is
recommended.
The cleaning rates for front end loaders working in
combination with a motorized grader were greater than
those of the motorized grader-motorized elevating scraper
combination by a factor of 8 for a crawler tractor mounted
front end loader and a factor.of 2 for the rubber tired
mounted front end loader.
Combination of Motorized Grader^
and Motorized Elevating Scraper
Motorized Elevating Scraper
Combination of Motorized Grader and
Front End Loader mounted on crawler
tractor
Combination of Motorized Grader and
Front End Loader mounted on rubber-
tired tractor
(a) For 500-ft distance to unloading area
(b) Motorized Grader operated at rate of 0
TIDAL ZONE
-------
516 OIL SPILL CLEANUP
SIDE VIEW
TOP VIEW
Bowl bottom
-«H
Bowl side
"'• • ~ - '
Figure 10: Steel Half-Tracks Mounted on Motorized Grader
-45"
Moterial: 1/4" plate steel
Two required
60"
**&K
. •
Figure 8: Design and Position of Baffle Plates
Figure 9: Sand Baffle Mounted in Bowl of Motorized Elevating
Scraper
Figure 11: Non-Self-Propelled Elevating Scraper
The effectiveness of the sand baffle plates in reducing
spillage was evaluated by performing tests with and without
the baffle plates installed. Test results given in Table 7 for
Test E-l and F-l, and Tests A-l and G-l show that under
the same beach condition, the addition of the baffle plates
resulted in the removal of a significantly smaller amount of
material. This was due to a reduction in spillage around the
edges of the bowl, which elliminated the need for
additional cleanup passes - passes which would be certain
to gather additional extraneous sand. However, when straw
was utilized as an oil absorbent, there was no significant
difference in the pickup efficiency of the baffle-equipped
motorized elevating scraper and the conventional unit.
Steel Half-Tracks
The major problem in the use of the motorized grader
was its inability to maintain traction when operating on a
beach of low-bearing sand. Flotation tires on all wheels will
overcome this problem on most beaches; however, a
motorized grader equipped with flotation tires became
immoblized on Francis State Park Beach. A set of steel
half-tracks were mounted on the motorized grader (see Fig.
-------
EARTH MOVING EQUIPMENT 5)7
10) and evaluated. The addition of the steel half-tracks
enabled the motorized grader to maintain traction but the
low-shearing strength of the sand prevented proper
formation of windrows. The sand would roll under the
blade or spill around the leading edge of the blade. Under
such beach conditions, a tracked front end loader or towed
elevating scraper would have to be utilized for the removal
of oil-contaminated material.
Towed Elevating Scraper
On certain beaches of low-bearing strength, the
motorized elevating scraper in its present configuration
became immobilized. Under these circumstances, a
non-self-propelled elevating scraper, pulled by a tracked
bulldozer, should be used.
A Johnson Model 80-C (Fig. 11), non-self-propelled
elevating scraper connected to a crawler tractor, was used
on the Francis State Park Beach. This combination proved
very effective in making thin cuts both in the tidal zone and
backshore areas.
STRAW REMOVAL
Straw has been the most widely used material for
absorbing oil on both water and beach areas. However, the
subsequent removal of straw from beach areas has involved
the use of large amounts of manual labor. During the Phase
II tests, straw was used to cover the film of or! dispersed
during the full-scale demonstration Tests B-2 and E-2.
Figure 6 shows the straw being distributed over a test area
by means of a straw blower.
The straw was effectively removed from beach areas by
both the motorized grader and motorized elevating scraper
in combiantion and by the motorized elevating scraper
operating alone. The effectiveness of straw in absorbing oil
on beach areas will depend upon the time of initial contact
with the oil. If the oil has time to penetrate into the beach
surface, straw will not be beneficial. However, if straw is
applied very soon after the oil arrives or on oil lying in
pools, it is most effective in decreasing the amount of oil
that would be picked up by the tires of rubber-tired
equipment. Additionally, as noted in the Phase I tests,
straw tends to act as a binder for sand and reduces spillage
around the edges of the bowl on the motorized elevating
scraper as it makes a thin cut or picks up windrows.
UNLOADING RAMP AND CONVEYOR SYSTEM
The use of an unloading ramp-conveyor system for
transfer of oil-contaminated material to trucks for disposal
was evaluated in Phase II. A ramp was constructed using
surplus railroad ties for the main structural support and a
track roadway over the conveyor bin. Figure 12 shows the
motorized elevating scraper positioned on the ramp prior to
unloading. The structural framework and roadway are so
designed that they can be easily relocated. Only earth
ramps at the new location would have to be constructed.
The conveyor system installed was used to load
oil-contaminated sand directly intotrucks(Fig. 13) and, with
a screening system attached (Fig. 14), to separate
oil-contaminated debris from the sand.
Figure 12: Motorized Elevating Scraper Positioned on Unloading
Ramp Prior to Unloading
'
Figure 13: Conveyor System Discnarging Oil-Contaminated Sand
Into Truck
Figure 14: Conveyor-Screening System Separating Oil-Straw
Mixture From Clean Sand
-------
518 OIL SPILL CLEANUP
A single-deck vibrating screen was used. The screen size
was determined by type of material to be separated. For
the separation of oil-contaminated straw or beach debris
from the sand, a 2-in. mesh screen was used at the upper
end of the screen deck and a 3/4-in. mesh at the lower end.
This combination of screen sizes was found to efficiently
separate all beach debris (kelp, seaweed, rocks, etc.) from
the sand and 70 to 80% of the oil-straw mixture. When
using the screening system to separate oil-sand pellets from
clean sand, the 3/4-in. screen was used at the upper end of
the screen deck and a 3/8-in. screen at the lower end. This
combination successfully separated all the oil-sand pellets
from clean sand.
The screening deck includes adjustable oversize and
concentrating chutes to direct the flow of oversize and
screened material (see Fig. 14).
COST ANALYSIS
The cost per unit of oil collected, unit of beach
material handled, and area cleaned (for the removal of a thin
film of oil from a beach tidal zone) was calculated for each
restoration procedure evaluated. These costs are tabulated
in Table 11. The cost of moving the oil-contaminated sand
to an unloading area is tabulated separately from the cost
of transporting the material to disposal sites at various haul
distances. The cost of a conveyor system to transfer
material into trucks is included in the removal costs for
restoration procedures utilizing motorized elevating
scrapers. Those restoration procedures utilizing front end
loaders are assumed to unload material directly into trucks.
The beach-restoration procedures that provided the lowest
removal costs are those that utilize a motorized elevating
scraper singly or in combination with a motorized grader.
The removal cost per acre is the principal cost to be
considered in planning beach-restoration operations. The
cost per gallon of ofl removed is a function of the initial
oil loading and the cost per cubic yard removed is a
function of the effectivness of the equipment in making a
thin cut with a minimum of spillage. The transport costs are
a function of the amount of material removed to clean a
beach area. The higher transport costs associated with
restoration procedures utilizing front end loaders reflect the
inefficiency of front end loaders in removing
oil-contaminated material. Heavier initial oil loadings than
the 0.5 gal/sq yd used in this test program would have little
to no effect on the cleaning cost per acre if oil penetration
is limited to 1 in. However, the removal cost per gallon of
oil would decrease in proportion to the increase in oil
loading.
The beach-restoration costs associated with the Santa
Barbara (California) and Grand Island (Louisiana) .oil-spill
incidents were calculated from information reported in
Refs. 10 and 11. The available data, was inadequate for a
complete cost analysis, but an approximation of the cost
• '
*The cost analysis is based on information given for the cost per mile
of beach cleaned with no mention of width of beach cleaned. There-
fore, as the width of beach assumed to be cleaned increases, the cost
per acre decreases.
per acre of beach cleaned was made. At Santa Barbara, it
was statedlO that a work force of 50 men aided by 4 front
end loaders, 2 bulldozers and 10 dump trucks could clean 1
mile of beach per 8-hour day. By applying current local
equipment rental rates and the prevailing labor rates in the
Santa Barbara area, a cleaning cost of $325 per acre was
calculated for 1 mile of beach 75 ft wide, and $500 per acre
for 1 mile of beach 50 ft wide.* The cost of trucks was not
included since not enough data were available on length of
haul and number of trips per truck.
At Grand Island, the restoration procedure involved
the use of motorized graders operating in conjunction with
front end loaders. A work force of 1 motorized grader, 3
rubber-tired front end loaders, and 20 men cleaned 15 miles
of beach in 4 days. The cleanup cost was calculated on the
same basis used for the Santa Barbara incident. This yielded
a cost of $140 per acre for 1 mile of beach 20 ft wide, and
$170 per acre for 1 mile of beach 15 ft wide. As in the
Santa Barbara calculation, trucking costs were not included
because of insufficient data.
Comparison of these costs with those listed inTable 11
for the beach-restoration procedures evaluated in this
program shows that the Grand Island costs are comparable
to those calculated for the motorized grader-front end
loader combination. The advantages of utilizing motorized
elevating scrapers in beach-restoration operations is readily
apparent when comparing the $108 per acre cost versus
$325 to $500 per acre cost incurred at Santa Barbara,
where a large amount of manual labor was utilized.
FINDINGS
Based on the efficiency with which each
beach-restoration procedure collects ^>r spills
oil-contaminated material and on the overall production
rates determined for
• Motorized graders
• Motorized elevating scrapers
• Front end loaders
• Conveyor-screening system
utilized singly or in combination, the following findings are
offered:
1. A motorized grader and motorized elevating scraper
working in combination provide the most rapid means
of beach-restoration when oil penetration is limited to
less than 1 in. For oil penetrations greater than 1 in., the
motorized elevating scraper operating singly is more
efficient. In addition, the use of motorized graders and
motorized elevating scrapers working in combination
results in the removal of the smallest amount of
uncontaminated beach material.
(a) The optimum moldboard (blade) angle for the
motorized grader, in which minimum spillage
occurred while windrowing sand, was found to be
50 deg from the perpendicular to the direction of
travel. At smaller angles the sand builds up on the
moldboard and spills around the leading edge. At
-------
EARTHMOVING EQUIPMENT 519
'a) (b)
Restoration Procedui Removal Cost
( $ \ ( $\ ( $ \
\qu yd/ \gal/ \acre/
Combination of motorized grader and
9 cu yd motorized elevating scraper
with 24-in. belt conveyor system 0.37 0.05 118
9 cu yd motorized elevating scraper
with 24-in. belt conveyor system 0.32 0.045 108
Combination of motorized grader and
3 cu yd rubber tired front end loader 0.75 0.07 176
Combination of motorized grader and
2 cu yd tracked front end loader 2.50 0.19 450
Tracked "ront end loader 1.92 0.64 1,540
(c)
Transport Cost CS/Acre) to
Disposal Area at
Indicated Distance
Miles
1 5 10 2O
30 90 150 3OO
32 93 161 321
25 77 124 220
20 60 96 173
88 261 420 757
(a) Basfd on initial oij loading of 0.5 gal/sq yd
(b) Based on 60-min working hour
(c) Based on 15-cu-yd-capacity trucLs
Table 11: Cost Summary for Removal of Thin Film of Oil from Beach Tidal Zone
elevating scraper may become immobilized during
the conduct of beach-restoration operations. For
such beaches, flotation tires or steel-belted
half-tracks on the motorized grader and a
non-self-propelled elevating scraper with a tracked
prime mover should be used.
(e) The addition of the sand baffle plates to the
motorized elevating scraper bowl resulted in the
removal of a significantly smaller total amount of
material in the course of removing a thin film of oil.
This was due to a reduction in spillage around the
edges of the bowl, which eliminated the need for
additional cleanup passes — passes which would be
certain to gather additional extraneous sand.
However, when straw was utilized as an oil
absorbent, there was no significant difference in the
pickup efficiency of the baffle-equipped motorized
elevating scraper and the conventional unit.
Figure 15: Motorized Grader Casting Second-Pass Windrow-
larger angles, the operator loses the fine control of
the blade and has difficulty keeping a constant
depth of cut.
(b) Straw spread on beach areas is easily windrowed
by the motorized grader and removed by the
motorized elevating scraper. Removing straw
directly with a motorized elevating scraper posed no
problems.
(c) Kelp, seaweed and similar debris do not
interfere with the operation of either the motorized
grader or motorized elevating scraper.
(d) On beaches possessing low shear strength, both
the rubber-tired motorized grader and motorized
PLAN VIEW
direction
of travel
Figure 16: Motorized Grader Operational Sequence
-------
520 OIL SPILL CLEANUP
Figure 19: Motorized Elevating Scraper Making Third Pass on Test
Area Contaminated With Oil-Straw Mixture
Figure 17: Motorized Elevating Scraper in Position to Remove
Windrow
*•» *
•1£ f !
Figure 18: Motorized Elevating Scraper Removing Thin Film of Oil
2. The oil removal effectivness was greater than 98% for
all restoration procedures. The highest effectiveness was
achieved through the use of the motorized grader and
motorized elevating scraper working in combination.
Figure 20: Motorized Elevating Scraper Removing Oil-Sand Pellets
from Test Area
The lowest effectiveness was obtained with the tracked
front end loader.
3. The interaction between the oil loadings employed
during the test program and the various equipment types
evaluated was minimal, i.e., the presence of the film of
oil on the beach surface did not affect the ability of the
equipment to pick up, cut, or transport the
contaminated beach material. It is believed that this
finding could be extrapolated to oil loadings several
times greater.
4. A front end loader mounted on a crawler tractor is
the most inefficient apparatus tested. In addition, more
spillage occurs with its use than with any other
equipment. We believe these results can be extrapolated
to apply also to bulldozers. If front end loaders are
utilized, it should be in combination with motorized
graders, thus minimizing the volume of material
removed and increasing the cleaning rate.
-------
EARTHMOVING EQUIPMENT 521
RESTORATION PROCEDURE
METHOD OF OPERATION
A. Combination of motorized
grader and motorized
elevating scraper
(Figs. 15,16,17)
B. Motorized elevating
scraper
(Figs. 18,19,20)
C. Combination of motorized
grader and front end
loader
D. Front end loader
Motorized graders cut and remove surface layer of beach material and
form large windrows. Motorized scrapers pick up windrowed material
and haul to disposal area for dumping or to unloading ramp-conveyor
system for transfer to dump trucks. Screening system utilized to
separate beach debris such as straw and kelp from sand when large
amounts of debris are present.
Motorized elevating scrapers, working singly, cut and pick up surface
layer of beach material and haul to disposal area for dumping or to
unloading ramp-conveyor system for transfer to dump trucks. Screen-
ing system utilized to separate beach debris such as straw and kelp,
from sand when large amounts of debris present.
Motorized graders cut and remove surface layer of beach material and
form large windrows. Front end loaders pick up windrowed material
and load material into following trucks. Trucks remove material to
disposal area or to conveyor-screening system for separation of
large amounts of debris from sand.
Front end loaders, working singly, cut and pick up surface layer of
beach material and load material into following trucks. Trucks
remove material to disposal area or to conveyor-screening system
for separation of large amounts of debris from sand.
Utilize restoration procedures C and D only in instances where motorized elevating scrapers are not
available. Operations of front end loaders on oil-contaminated beach areas should be kept to a
minimum.
Table 12: Recommended Restoration Procedures
5. A non-elevating motorized scraper will not operate
efficiently on beach areas unless a tracked prime mover
is used as the principal source of power or as a pusher to
assist in loading. A thin cut is difficult to maintain, and
excess spillage occurs when loading.
6. Beach-restoration operations on backshore areas
become very difficult due to the looseness of the sand.
Procedures for minimizing the oil contamination of
backshore areas should be instituted at the first
indication of a possible shoreline-pollution event. Under
normal tide conditions, a berm or dike at the high-tide
mark can prevent oil from contaminating backshore
areas.
7. Conveyor-screening systems can be effectively
utilized to: (a) load oil-contaminated material into
trucks for transport to disposal areas, (b) separate
oil-sand pellets from clean sand, and (c) partially
separate oil-contaminated debris (i.e., straw, kelp,
seaweed) from oil-contaminated sand.
8. The mixing action that occurred in the cutting
and/or pickup of a thin film of fresh oil and the
underlying clean sand results in a uniform oil-sand
mixture. Under these conditions, it is not possible, by
screening techniques, to separate oil-contaminated sand
from clean sand.
The cost of removing a thin film (0.5 gal/sq yd) of
oil from a beach tidal zone ranged from $108/acre (with
a motorized elevating scraper operating alone), to
$1540/acre (with a tracked front end loader operating
alone). These costs are based on a haul distance (to
unloading area) of 500 ft and average equipment rental
rates.
As a result of the tests conducted in this study, the
restoration procedures listed in Table 12 are
recommended for use in the restoration of
oil-contaminated beaches.
REFERENCES
1. Review of the Santa Barbara Channel Oil Pollution
Incident, Water Pollution Control Research Series, DAST
20, July 1969
2. Offshore Mineral Resources, Second Report of the
President's Panel on Oil Spills, Executive Office of the
President, Office of Science and Technology, 1969
3. The Torrey 'Canyon, Report of the Committee of
Scientists on the Scientific and Technological Aspects of
the Torrey Canyon Disaster, Her Majesty's Stationery
Office, London, England, 1967
4. Earl, J. R., and J. D. Sartor, Report of Land
Reclamation Tests, U.S. Naval Radiological Defense
Laboratory, San Francisco, California (AD-332E), March
1952
5. Earl, J. R., and J. D. Sartor, Report of Land
Reclamation Tests, Conducted During Operation JANGLE,
WT-400, February 1952
-------
522 OIL SPILL CLEANUP
6. Sartor, J. D., H. B. Curtis, H. Lee, and W. L. Owen, Cost
and Effectiveness of Decontamination Procedures for Land
Targets, STONEMAN I, U.S. Naval Radiological Defense
Laboratory, USNRDLTR-196, December 27,1957
7. Lee, H., J. D. Sartor, and W. H. Van Horn, STONEMAN
II, Test of Reclamation Procedures, U.S. Naval Radiological
Defense Laboratory, USNRDL-TR-337, January 12,1959
8. Owen, W. L., and J. D. Sartor, Radiological Recovery of
Land Target Components - Complex land Complex II, U.
S. Naval Radiological Defense Laboratory,
USNRDL-TR-570, May 25,1962
9. Owen, W. L., and J. D. Sartor, Radiological Recovery of
Land Target Components - Complex III, U. S. Naval
Radiolgoical Defense Laboratory, USNRDL-TR-700,
November 20,1963
10. Gaines, T. H., Oil Pollution Control - Santa Barbara,
California, Union Oil Company of California, 1969
11. Humble Oil News Letter, February 1970
-------
FROTH FLOTATION CLEANUP OF
OIL-CONTAMINATED BEACHES
Garth D. Gumtz and Thomas P. Meloy
Meloy Laboratories
ABSTRACT
Based on laboratory studies and prelmiruuy design, a
30 tons per hour froth flotation plant was built for cleaning
oil contaminated beach sands. Selected laboratory data and
demonstration data for three tests are considered in this
paper. The essential elements for plant operation were'^a
froth flotation machine, belt feeder, oil recovery tank,
process water pump, water supply, elevating scraper, and
front end loader. Demonstrations ranged from nominal runs
with feed rates of 30 tons per hour and oil concentrations
of 0.5% to one run at 60 tons per hour and another with an
oU concentration approaching 3%. Some of the conclusions
reached during the study were: 1) sea water is advantageous
to the process, 2) similar (about 125 parts per million) or
better residual oil concentrations should be possible when
water is not recycled, and 3) mobilization of a froth
flotation beach cleaner is feasible.
The work discussed in this paper was performed in
fulfillment of Contract No. 14-12-809 between the Water
Quality Office of the Environmental Protection Agency and
Meloy Laboratories (Mel-Labs, Inc.).
Froth Flotation Cleaning of
00 Contaminated Beaches
INTRODUCTION
When oil pollutes a sandy beach, no single form of
contamination takes place: It depends on the type of oil,
length of time at sea, temperature, time the oil has been on
the beach, and type of sand. Some oils, sufficiently long at
sea, will arrive at the beach as pebbles or streaks, and can be
*Based on work performed in fulfillment of Contract No.
14-12-809 between the Water Quality Office of the Environmental
Protection Agency and Meloy Laboratories (Mel-Labs, Inc.).
removed easily by a beach cleaner. Other types of oil
(particularly crudes) which have been at sea for a long time
are water-oil emulsions that are somewhat similar to butter,
and look like chocolate mousse. These emulsions, while on
the beach, are altered by environmental and biological
impact; they become putty-like and finally brittle. This
type of pollution can also be cleaned up by a beach cleaner
or dry screening. Fresh crude (and many fuel oils) will
penetrate the sand, coating sand particles and filling some
of the interstitial voids in the beach.
Experience with liquid oil falls indicates that the depth
of penetration and position of the contaminant is not easily
ascertained from the surface. Uncontaminated sands may
bury the contaminated part, and the width and depth of
the oil contamination may vary markedly within short
distances; thus, finding the contaminated sand can be
expensive. Modern practice has been to take large swathes
of the beach and, as spots of contamination remain, to
either take a second cut of sand or dig out the contamina-
ted spots by hand. This results in a large amount of sand in
which relatively small sections are contaminated. Thus, any
cleanup procedure must either concentrate contaminated
sand or be very economical in the treatment of the
contaminants.
The Corps of Engineers uses the figure of $5.00 a cubic
yard for the replacement of sand on a beach. This price
includes finding the sand, transportation, and addition of
the sand to the beach. Any process used in beach
restoration must consider that cleaning costs greater than
$5.00 a ton are in competition with simply removing the
sand, disposing of it, and replacing it with fresh sand.
Oil-soaked sand is an ideal material for cleaning by
froth flotation because processing costs are very low and
very little, if any, chemical or physical pretreatment is
called for. The sand does not need crushing because it is
naturally finely divided, and it is also relatively free of
"slimes." The sand is naturally hydrophilic and the oil is
naturally hydrophobic. Many oils froth rather easily. The
523
-------
524
OIL SPILL CLEANUP
oil is less dense than either the watei or the sand, thereby
facilitating flotation.
Large quantities of sand are cleansed by flotation in
the United States. New Jersey optical sand is cleaned by
floating iron-bearing minerals from the bulk of the siliceous
sand; iron stains on the sand surface are removed by the
violent actions occurring in pumps, flotation cells, and
cyclones; this sand, after cleaning, is sold for $3.00 a ton.
In North Carolina, sands are float-cleaned and scrubbed by
pumps and cyclones; they are sold throughout the country
for use in golf traps; this sand is exceedingly white. Dark
brown tar sands in Canada are floated in hot water to
remove the ofl, using an otherwise standard flowsheet; these
sands come out very white. Flotation has often been used
to clean and to separate ofl from sands.
Extensive laboratory experiments at Meloy Labora-
tories indicated that froth flotation with appropriate
scrubbing permits the cleaning of a wide range of sands
contaminated with a wide variety of ofls. "Oils", ranging
from a very light crude whose nature was much like
gasoline to a baked solid fuel oil, were successfully removed
from mixtures with sands, ranging from Dam Neck beach
with 100% of its grains smaller'than 841 microns to a
yellow river sand with almost 10% by weight larger than
1.68 mm. The ofls were aged and unaged and deposited on
both wet and dry sand. In every case in which it was
attempted, it was relatively easy to select a combination of
operating conditions under which the cleaning process
worked. In short, flotation seemed to have considerable
promise for the cleaning of ofl contaminated beach sands.
Based on the laboratory experiments and on consulta-
tion with individuals and literature familiar with the glass
sand cleaning industry, Meloy Laboratories proceeded with
the design and construction of a beach cleaning demonstra-
tion plant. Preliminary design of the plant involved con-
siderations analogous to the design of sand cleaning and
froth flotation plants in the mining industry. Two criteria
were primary in the initial design: First, the plant was to
operate at a sand feed rate of about 30 tons/hour and be
entirely self-contained, and, second, the cleaning system
was to be closed as completely as was practical so that no
extraneous ofl contamination could result from the opera-
tion of the plant during the demonstration studies. Of
course, all the plant components had to be relatively
resistant to a marine environment, and provision had to be
made for running analyses of ofl concentrations in both
sand and water at the site.
A suitable site was found in the vicinity of Virginia
Beach, Virginia; specifically, it was on the U. S. Navy's
Fleet Anti-Air Warfare Training Center at Dam Neck,
Virginia. Navy representatives reviewed the proposed pro-
ject and conferred with Meloy Laboratories' technical staff
before leasing the site in early 1970. Check out of the plant
unit operations began in mid-September of 1970 and was
completed in less than a month. The first actual plant
demonstration took place on October 6,1970.
The demonstration studies took place under conditions
comparable to those of a medium-sized minerals processing
plant. The major differences were due to the comparative
isolation of the site from the, sometimes, necessary support
services. These differences were, however, themselves a
valuable education since a mobile beach cleaning unit may
very well have to be operated under similar isolation.
Although directly aimed at demonstrating the efficacy of
the froth flotation process for cleaning ofl contaminated
beach sands, the project also provided a wide variety of
knowledge about the field operation of such a system. This
knowledge ranged from the problems expected in operating
unmodified heavy equipment on a beach to the deleterious
effect noticed for the attrition scrubbing of a "normal"
oil-sand mixture.
The project contract called for running five demonstra-
tions: these were: 1) a nominal run with a sand feed rate of
25 to 30 tons/hour and an oil contamination level of 0.5 to
1.0% by weight of medium fuel oil, 2) the same as number
1 but with a heavy fuel oil, 3) the same as number 1 but
with a sand feed rate of about 20 tons/hour, 4) the same as
number 1 but with the ofl partially sorbed into straw before
deposition, and 5) the same as number 3 but with a much
higher ofl content (estimated at 3% by material balance).
The results of these tests were briefly as follows. Under
nominal conditions, with the closed loop process, the sand
was cleaned to an acceptable level (less than 150 ppm oil in
the water saturated, cleaned sand), and the change to a
heavier oil made little apparent difference in the efficacy of
the process. Lowering the sand feed rate had significant
effect on the processed water and little effect on the
cleaned sand. The presence of straw demands much more
continuous attention to the belt feeder unit operation;
apparently, straw also promotes dispersion of ofl into
water. Finally, the system islimitedmainly by the total flow
of ofl through it with a maximum acceptable level of oil
contamination at 30 ton/hour sand feed rate of about 1%.
. An elevating scraper and front end loader were
necessary for plant operation. One of the first problems
with the demonstrations was getting this equipment to
operate satisfactorily in loose beach sand; there was no
problem on the beach itself; the problems came when the
heavy equipment had to move between the plant and the
beach. Reliable transport was finally achieved when pierced
steel planking was laid in a single track from the plant to the
beach; some such provision should also be made for a
mobile unit since vehicles with balloon tires or tracks may
not be available.
The field work did show that the major items of
process equipment are very dependable under even very
severe weather conditions; this portends well for a mobile
unit. The components which did give trouble were the
pumps and dewatering cyclone; since none of these items
are envisioned for use in actual emergency operations,
problems with them are not particularly relevant. The
hopper and belt feeder, flotation machine, and leased
submersible pump operated very dependably over long time
periods; maintenance was also only of minor concern. Since
these three items represent (along with a suitable power
supply) a mobile beach cleaner, the results of the field tests
were quite heartening.
-------
FROTH FLOTATION CLEANING
525
LABORATORY STUDIES
The purpose of the laboratory studies in this project
was threefold. In the first place, it was shown that flotation
cleaning of oil contaminated beach sand is feasible in the
context of the original proposal (feasibility studies); experi-
ments which simulated the "natural" contamination of
beaches were also successful (simulated beach conditions).
Secondly, by attempting to clean severely contaminated
samples of beach sand, limits were placed upon the
probable, successful operation of the proposed plant. These
limits were found to confine a zone of plant operation
which is much broader than originally thought possible.
.Third, a quantitative method was developed for measuring
61 contamination levels. This method was used in the
laboratory while running two series of tests on the effects
of operating conditions on the efficiency of a laboratory
scale froth flotation machine; these lab tests are the only
ones considered in detail in this paper.
The general problem of determining quantitatively the
contamination of sand by oil was beyond the scope of the
project. Both sands and oils are too variable to expect that
there is any easy way to do this. What was needed,
however, was a quantitative technique which will work
specifically for a given oil and beach sand. A number of
possible techniques came to mind: photometrically meas-
uring the reflectance of visible light from beds of sand,
spectrometrically measuring the oil concentration in a
solvent which has been used to extract oil from sand,
chemically determining the concentration of carbon in a
solution obtained by digesting a sample of sand with an
appropriate chemical, measuring the transmittance of light
through an oil-sand-liquid mixture where the liquid has a
refractive index which is the same as the sand's, and using a
gas analyzer (methane or general hydrocarbon) to detect
the "odor" of contaminated sand. The second of these was
finally settled upon as being most practical and amenable
to field test conditions.
Solvent extraction combined with spectrometic anal-
ysis does not have the same limitations as visual and
photometric evaluations. In principle, this technique may
be used to detect oils which are invisible to the human eye.
Wave-lengths may also be sought which maximize absorp-
tion and, thereby, maximize detection sensitivity; unfortu-
nately, for complex mixtures like oils no general analytical
scheme can be worked out. Spectrometric analysis is much
more suited for detecting the components of a mixture
than the mixture itself. However, in the case of a known
contaminant a suitable correlation can be developed. Much
of the discoloration due to oil pollutants can be related to
suspended solids: asphaltenes, carbenes, carboids, etc.;
these solids are not removed by most solvent extractions
and, therefore, are not usually detected by this technique.
For fixed oil, sand, and solvent this method should be
successful; it was, for this reason, used'during the demon-
stration study.
Several solvents were tested for the analysis of sand
and water samples. Benzene was finally selected due to its
efficacy with the fuel oils most commonly used in the
demonstration plant (numbers 4 and 6). It also had the
advantage of being relatively low in cost while still of
analytical quality. Briefly, the analytical scheme went as
follows. A sample of the oil to be used as a contaminant
was put into solution with benzene; known amounts of
both materials were used to make up these standard
solutions. The concentrations of oil in the benzene solu-
tions were then correlated in the usual manner with
transmittance readings from a Spectronic 20 spectrophoto-
meter by Fischer Scientific Company. As expected, concen-
tration varied linearly with the logarithm of the trans-
mittance at a fixed wavelength of incident light. Plots or
correlations of this sort had to be made up for each sand-oil
combination considered; since such correlations involve
standard, classical analytical chemistry, no examples of
plots are presented here. The wavelength of light was
generally around 450 millimicrons. Before unknowns could
be confidently considered, the standard correlations had to
be available; if they were not, the best that could be done
was to express contamination levels in terms of equivalence
to some known oil contamination.
Generally, large variability of samples was discovered
under full scale, field test conditions; this was not unex-
pected; Background contamination in the sand at the field
site was not insignificant. The analytical results of one
demonstration indicated a background contamination of
about 20 ppm in the Dam Neck beach sand prior to
contamination; this concentration is, of course, an equiva-
lent value in terms of the No. 4 fuel oil which was
eventually used to contaminate the sand.
Toward; the end of Phase I of the program, the
analytical technique described above was used in some
limited laboratory studies aimed at the effect of varying
froth flotation operating parameters. The results of these
studies are discussed below.
The first series of tests sought to attach numbers to the
effect of increasing turbulence in the laboratory flotation
cell. The analytical results for these tests are presented in
Table 1. Aeration rates were varied in three steps from the
minimum rate to the maximum for each of four impeller
speeds; the minimum rate was dictated by the lower limit
of the rotameter used to measure aeration and was,
therefore, the same for each impeller speed while the
maximum rate was itself a function of the impeller speed.
Average residual oil concentrations in the cleaned sand
increased fairly regularly with increasing impeller speed:
averages of 107, 101, 190 and 300 parts per million oil by
weight for 1000,1200, 1800 and 2400 rpm impeller speeds
respectively. There is an implication in this averaged data
that an optimum exists with respect to impeller speed; "a
priori," this must be the cast since at zero impeller speed
contaminated sand would settle to the bottom of the cell,
never contact air bubbles, and therefore, never be cleaned
while at very high impeller speeds any oil which rose to the
top of the flotation cell would immediately be returned to
the sand slurry due to the intense mixing action and,
therefore .cleaning would once again not occur. The data was
not, however, precise enough to allow a determination of
the optimum impeller speed on the basis of only 16
laboratory tests. Such a result relative to precision is
classically found for froth flotation on any scale; compre-
-------
526 OIL SPILL CLEANUP
hensive test work in the minerals industry always involves
large numbers of repetitive tests on a large numbers of
samples.
Table 2: Analytical Results for Series Two Lab Tests
Table 1: Analytical Results for Series One Lab Tests Sand Charg£ Aeration Rat6j Maximum
Impeller Speed Aeration Rate
revolutions per minute (liters per minute)
1000
1000
1000
1000
1200
1200
120
1200
1800
1800
1800
1800
2400
2400
2400
2400
1.35
3.55
6.10
8.85
1.35
4.80
8.85
13.25
1.35
8.85
16.2
19.2
1.35
6.10
11.8
26.8
Oil in Cleaned
Sand
(parts per Million
by Weight)
173.1
84.3
82.1
87.5
131.9
118.4
94.5
60.1
483.0
127.6
75.6
72.5
302.2
400.0
360.4
137.1
These tests were run with the Wemco laboratory test
flotation machine; each involved a 300 gram charge of sand
contaminated at 5.00% with number 4 fuel oil and a froth
flotation time of 3.5 minutes. A standard 3 liter cell was
used for each test.
These test results may also be used to gain a semi-quan-
titative grasp of the effect of aeration rate on the process.
Each impeller speed was tested at four aeration rates which
may be designated as low, medium low, medium high and
high; the averages over the four impeller speeds at each of
these levels is 273, 183, 153 and 89 parts per million
residual oil respectively. This result shows clearly that
increased aeration decreases residual oil contamination over
the range of conditions considered; this was not unexpected
although high enough aeration rates should eventually
promote a degradation in residual oil concentrations.
The second series of laboratory tests looked for the
effect, on a quantitative basis, of three variables: magnitude
of sand charge, initial ofl concentration and aeration rate.
The results of these tests are presented in Tables 2 and 3.
The data for increasing sand charge are somewhat incon-
clusive although a general trend towards increasing residual
ofl with increased charge can be seen. This makes sense for
fixed feed concentration, impeller speed, flotation time and
(relatively) aeration rate; increased sand charge implies
increased total ofl in the cell which, in turn, implies
increased solubflized and dispersed ofl in the process water,
some of which is always recovered with the cleaned sand.
The twelve tests which considered three fixed aeration
rates (see Table 3) confirmed the semi-quantitative results
of the series one tests. The averages over the four initial ofl
concentrations were 109, 139 and 160 parts per million of
(grams) (liters per minute)
100 12.8
250 12.5
400 11.8
550 11.8
700 10.4
Oil in Cleaned
Sand
(parts per million
by weight)
49.4
107.4
128.9
130.0
82.8
*These tests were run with an impeller speed of 1200 rpm,
a feed No. 4 fuel oil concentration of 5.00% and a 3.5
minute flotation time; again, the standard test cell was
used.
Table 3. Analytical Results for Series Two Lab Tests
Initial Oil, Oil in Cleaned
Concentration Sand
(No. 4 Fuel Oil) Aeration Rate (parts per million by
(percent by weight) (liters per minute) weight)
1 11.8 135.1
3 11.8 64.6
5 11.8 77.5
9 11.8 160.1
1 6.1 54.5
3 6.1 110.4
5 6.1 186.1
9 6 1 203.6
1 1.35 39.0
3 1.35 130.2
5 1.35 182.6
9 1.35 289.8
*These tests involved an impeller speed of 1200 rpm and a
250 gram charge of contaminated sand; again, a standard
test cell and a 3.5 minute flotation time were used.
residual oil for aeration rates of 11.8, 6.1 and 1.35
liters/minute respectively. This is good quantitative evi-
dence that increased aeration decreases the amount of
residual oil in the cleaned sand. Again, the data was
averaged over four tests at the same aeration rate; a more
comprehensive test program would have to involve repeti-
tive testing under identical conditions to allow statistical
evaluation of the analytical results. Fortunately, the test
work discussed here was more to verify the practicability of
the technique used to measure oil contamination levels
rather than to study, in depth, the laboratory scale cleaning
of ofl contaminated beach sand by froth flotation. Such an
in-depth study could be a project in its own right, although
its value relative to full scale cleaning operations would be
dubious.
Averaging over the three aeration rates (see Table 3)
for the four initial oil concentrations gives a quantitative
indication of the effect of feed oil for intital concentration
-------
FROTH FLOTATION CLEANING
527
on the process: 76, 102, 149, and 218 parts per million
residual oil for initial concentrations of 1, 3, 5 and 9%
respectively. This result substantiates quantitatively what
had been observed qualitatively in other tests: For
"significant" feed oil concentrations there is apparently a
bottoming out of residual oil concentration; in other words,
there is a minimum (and finite) exit concentration of oil in
the cleaned sand which cannot be eliminated except by
decreasing the feed concentration of the oil to a very low
level (this is, from an applications viewpoint, an impractical
way to reduce the residual oil level.) This minimum oil
concentration is (considering the data presented above)
about 60 ppm or 0.006%; feed oil concentrations would
have to be reduced to about this level to effect any further
large decreases in residual contamination.
The analytical problems observed during the laboratory
tests were also of importance during the field demonstra-
tions. Over and above this, the field tests presented their
own special difficulties: lack of, for instance, homogeneity
of the feed sand, control over operating temperatures, truly
representative sampling, and absolute control over all
process materials. Such considerations were somewhat
important during the laboratory test program, but they had
to be kept constantly in mind when the analytical results of
the full scale test program were considered.
DEMONSTRATION STUDIES
Figure 1 is a flowsheet of the plant which was
constructed and operated at Dam Neck, Virginia. As can be
seen, the operation was essentially that of a closed system.
This becomes even more obvious when it is realized that the
actual plant site was within a depression in the sand dunes
above the beach. It was literally possible to dump and
experiment with oil at will in the area of the plant. This
was, of course, not true for the area of the beach which was
also used for the demonstrations. When oil was spilled on
the beach to contaminate the sand, great care had to be
taken so that oil did not migrate into the surf. On some
beaches this would not be a problem, but at Dam Neck the
beach has a relatively great slope to it and is not at all flat.
The latter condition also had considerable impact on the
efficiency with which contaminated sand could be picked
up.
The flowsheet is self explanatory although it should be
remarked that the equipment items necessary for an
emergency field operation would be only the hopper and
belt feeder, the flotation machine and air blower, the oil
recovery tank, and an appropriate submersible pump to
deliver sea water from the surf. The extra pieces of
equipment represented in the flowsheet served to make the
plant both safer to operate (in the sense of not producing
unwanted contamination during the demonstrations) and
more flexible as regards the information which could be
gathered from the demonstrations. For instance, we knew
that if sand were contaminated in a fashion with which the
flotation machine could not cope, the scrubber could be
used to clean the sand at the price of very low capacity; to
resolve such a problem low capacity can be tolerated.
Second, the scrubber provided valuable information on the
effect of undue turbulence on the froth flotation cleaning
process; with high residence time the scrubber dispersed oil
so well into'the process water that the flotation machine's
efficincy was decreased drastically. However, note that this
also implies that repetitive scrubbing in combination with
dewatering and gravity separation of oil and water might
also be useful for cleaning oil contaminated sand.
Figure 2 is a photograph of the plant as seen from the
discharge end. It is obvious from this photograph that the
plant was quite a sprawling affair; this facilitated access to
the various system's components and made modification of
the plant for the purpose of the various demonstrations
relatively easy. Since only about half of the equipment
items would be necessary for a mobile unit and since they
could also be placed in much closer proximity to one
another, the demonstration plant, as such, is somewhat
misleading. The plant, of course, did give observers a much
clearer picture as to what was taking place in the process
than a mobile unit probably would.
Table 4 lists some of the data for the first plant
demonstration. Water rates were uniformly high during this
run although the attrition scrubber did operate at some-
thing more than its minimum residence time; this, of
course, was eventually found to be deleterious to the
process. The number 4 fuel oil used in this demonstration
was sprayed on the beach using a T-bar system with a small
compressor; the sand was wet down ahead of the oil spray.
Due to the undulating nature of the beach, the elevating
scraper which was used to pick up the contaminated sand (a
WABCO Dill A) could not do better than a four or five
inch cut. Even with this relatively deep cut it was still
necessary to go back over the contaminated area with a
front end loader and shovels to make sure that no oil
contamination remained on the beach. The standard devia-
tions of the measured average oil concentrations are quite
high; this is not surprising since 1) the samples taken were
small relative to the total processing rates and 2) there was
no provision for mixing the feed sand into something like a
homogeneous state. This test, as did all others with the
closed loop in operation, involved a continually increasing
concentration of oil in the exit water. This was first
observed visually as the feed water to the plant became
more and more contaminated (see the feed water analyses
in Table 6); since plant start up involved an operating
period of 45 minutes in which the plant was allowed to
come to steady-state, the feed water contained a significant
amount of oil by the time sampling was initiated. Compari-
son of the oil contents between the feed and cleaned sands
is, however, quite encouraging.
Table 5 presents data for the third demonstration
which took place with a low sand feed rate relative to the
first. As can be seen from the table, the various processing
rates were essentially identical to those of the first
demonstration. The only obvious difference is that pine oil
was used as a frothing reagent in this test; this continued
for several of the following tests but was finally discon-
tinued when it was found that the sample analyses did not
-------
PROCESS MATER TAMX
(JO n. DJA. « i n. m.)
(PLASTIC COMTMKtlOU)
MAXB*UP
PUMP (»• > 1 l/JM
»*» i rh 7 L,
OCBM^ LJ 4 " •*! I"1
II OP* MATIR \ /
tn an HATER
1 H3 «...
PROCEIS MATER PUMP («• M 3")
TATS MaiHEERIlM
10 GPH ,10 OFH 109 aPN 10 0PM
MATER HATER MATER HATER C
1000 LS. /KIN. SAND - ._ _. .„., L
T " 11 IM 1 0 3 *^ **•
"?"* *"" "•UM™
***' \ / /•>''? 51 tfl IP
FEED HOPPER \ / / >X^ IB
d»» eu. rt.) \ / // [>C] ' i
\ / //^ M "*" r—
\ / ss \ QR1"1'* 9
j I/ FEEDER \ |~^
LIKI-EU.I, 1 1— •' 1 1 ^ VERTICAL1 ' ' 1
XMC* ATTRITION SLURRY PUMP (2 1/2')
mU KRUEBER (UiilOHIH KACHI»E»Y CO.
(loo eg, FT.)
(7S NT. % SOLIDS) FSHS
DENVER EBUIPHBNT co. 1 1
BASItl U TCK« OF (AMD FSI>>
PROCESSED PER HOUR FLOTATION AIR BLOHBR
TTPICAL DATAI FII37
SPECIFIC DRAVITZB*.
OIL t.10
MATER 1.00
DENSITIES,
BUL> SAND (1.5 LES./CU. FT.
MATER 1.31 LBS./CAL.
ISTIMATie POKER REQUIREMIHH
ATTRITION SCRUBBER CO HP.
FLOTATION CILLE 30 HP.
PUMPS t CONTROLLER 51 HP.
•CAM FEEDER 2 HP.
10 SFN HASB
, "**•* »UU LIVIL CONTROLLER
105 GPH ""» EgUIPHENT CO.
NATER f H P] 1
f
^ ~ N
M 9 ? ? «•«
PULP
BLURRI >
f PUMP (I* > 9')
DENVER
EQUIPMENT CO. ^
O
J-. 9W L«
* ' 45 am
\ /FLOTATION
/ CELLS
/ I2S m, 1 SOLIDS)
/ (240 CO. FT. )
/ DENVER EQUIPMENT CO.
/ FBI 30
20 LES/MIN. OIL
10 LBI/HIN. SAND
27 LBS/MII). KATtR
-
OIL RECOVERY TANK
U«00 CU. FT.)
(MOOD CONSTRUCTION)
FSI35A1B
m OPH
DENATERIHG
CYCLONE
124*)
/ RREBS
/
I./KTN. SAND
MATER
^
1™
r
o
r-
m
C
•o
ISO HP. OR 112 r». (RATED. NOT DESISN)
1ITIHATED RtllftlHCt TIHZI
(RASED OKLlf ON INPUT FLOWS)
FEED HOPPER
ATTRITION SCRUBBER
FLOTATION CILLI
OIL RECOVERY TANK*
PROCESS HATER TANK
I.I KIN.
1.5 M1N.
4.4 KIN.
12.2 HRS.
»0.0 NIK.
•NOT RUED Of FROTI VOLUB
Figure 1: Demonstration Plant Flowsheet
-------
FROTH FLOTATION CLEANING
529
Figure 2: Photograph of Dam Neck Demonstration Plant
(A. Hopper and Belt Feeder; B. Attrition Scrubber: C. Vertical
Sump Pump; D. Froth Flotation Machine; E. Horizontal Slurry
Pump; F. Dewatering Cyclone; G. Process Water Tank; H. Oil
Recovery Tank; 1. Electrical Shed: J. Office and Laboratory Trailer)
Table 6 gives data for a run in which the attrition
scrubber was by-passed; in all other respects that run was
identical to the third. The scrubber bypass was a sluice
which delivered sand from the end of the belt feeder
directly to the vertical pump's sump. The cleaned sand in
this test was much lower in residual oil contamination than
that in test three even though the feed sand was much more
contaminated. The exit water, however, was contaminated.
Some of this extra contamination can be attributed to the
finely dispersed oil entering the system in the feed water.
The temperature of the water during this demonstration
was also significantly lower than during number three
(something like 50°F). One of the important findings
during the project was that lower water temperatures
decrease process efficiency; although this was found to hold
for the full scale system, it was not observed during the
laboratory studies.
show any apparent benefit from the use of pine oil. The
lower sand feed rate caused an overall decrease in the oil
concentrations in the exit stream. The change of concentra-
tion in the cleaned sand should be considered an anomalous
result; the change in the exit water was, however, dramatic.
Of course, attaching importance to these changes assumes
that the feed sands in tests one and three were essentially
the same; this is not unreasonable since they were prepared
in identical ways.
CONCLUSIONS
The froth flotation demonstration studies at Dam
Neck, Virginia, demonstrated the feasibility of the process
for dramatically reducing the impact of oil pollution on
beaches without the physical disposal of contaminated
sand. Observations at the Dam Neck site led to the
conclusion that cleaned sand with parts per million residual
oil has very little impact when returned to a beach. At the
Table 4. Data for Demonstration Number 1
Sand feed rate
Total water feed rate
Water rate to attrition scrubber
Water rate to vertical pump
Water rate to flotation machine
Aeration rate
Screen spray rate
Launder wash rate
Water rate to horizontal pump
Rate of pine oil addition
Oil type
30 tons/hour
450 gallons/minute
110 gallons/minute
100 gallons/minute
220 gallons/minute
280 cubic feet/minute
20 gallons/minute
none
none
none
No. 4 fuel oil
Sample No.
Analytical Results
(parts per million by weight oil)
Feed Sand Feed Water Cleaned Sand Exit Water
(H2O saturated)
B
C
D
E
Average
Standard
Deviation
not
measured
but
estimated
at
0.5%
5,000ppm
n/a
n/a
not
measured
n/a
n/a
133
125
137
129
142
133
5%
348
263
216
162
443
286
39%
-------
530 OIL SPILL CLEANUP
Table 5. Data for Demonstration Number 3
Sand feed rate
Total water feed rate
Water rate to attrition scrubber
Water rate to vertical pump
Water rate to flotation machine
Aeration rate
Screen spray rate
Launder wash rate
Water rate to horizontal pump
Rate of pine oil addition
Oil type
Analytical Results
(parts per million by weight oil)
19 tons/hour
450 gallons/minute
115 gallons/minute
40 gallons/minute
215 gallons/minute
280 cubic feet/minute
80 gallons/minute
none
none
approximately 1 cc/minute
No. 4 fuel oil
Sample No. Feed Sand
Feed Water Cleaned Sand Exit Water
(H2O saturated)
A
B
B
C
D
E
F
G
H
I
Average
Standard
Deviation
4,180
2,750
2,750
4,125
4,850
5,200
6,600
3,070
3,040
3,260
4,096
29%
not
measured
218
157
129
183
141
250
209
214
211
196
21%
384
246
183
68
90
141
77
55
76
138
77%
-------
FROTHE FLOTATION
531
Table 6. Data for Demonstration Number 10
Sand feed rate
Total water feed rate
Water rate to attrition scrubber
Water rate to vertical pump
Water rate to flotation machine
Aeration rate
Screen spray rate
Launder wash rate
Water rate to horizontal pump
Rate of pine oil addition
Oil type
Analytical Results
( parts per million by weight oil)
Sample No. Feed Sand Feed Water
154
212
232
244
355
400
288
284
258
304
19 tons/hour
440 gallons/minute
none
235 gallons/minute
205 gallons/minute
280 cubic feet/minute
none
none
140 gallons/minute
approximately 1 cc/minute
No. 4 fuel oil
A
B
C
D
E
F
G
H
I
J
Average
Standard Deviation
7,100
9,000
4,160
8,840
7,050
4,800
6,740
6,450
11,900
4,160
7,020
Cleaned Sand
(H20 saturated)
100
106
99
106
79
93
104
125
120
132
Exit Water
622
340
230
284
615
600
615
303
630
825
273
106
496
34%
26%
14%
40%
worst, very, very limited visual evidence of oil appears due
to the action of surf and tides after sand has been returned.
The demonstrations served to show that froth flotation is
an adequate cleaning procedure without recourse to an
auxiliary scrubbing operation; therefore, mobilization of
the process becomes a relatively simple matter. This
technique becomes, perhaps, even more attractive when
cost estimates of 50 to 70 cents per ton of cleaned sand are
compared to the "baseline" cost of $5 per ton advanced by
the Army Corps of Engineers.
Finally, the authors wish to thank the Water Quality
Office for their support of the work discussed above. We
also express our gratitude for the efforts of the field
engineering crew without which this paper could not have
been written; B. C. Langley, K. W. Benson and S. J. Rose
are in a special sense co-authors.
-------
A HOT WATER FLUIDIZATION PROCE§S
FOR GLEAMING OIL-CONTAMINATED
BEACH SAND
Paul G.Mikolaj
University of California, Santa Barbara
and
Edward J. Curran
Standard Oil Company of California
ABSTRACT
A pilot device capable of cleaning one ton per hour of
oil-contaminated beach sand was built and tested. The
processing scheme was a variation of the hot water method
used in the Athabasca Tar Sand Deposits and utilized liquid
fluidization to effect the oil-sand separation. Tests per-
formed with a sand mixture containing 1 to 2 percent of a
23° API crude oil showed that upwards of 95 percent of
the oil could be removed. Operation with a 14° APT
residual oil was less satisfactory.
The hot water fluidization process is judged to be a
technically feasible concept although there appear to be
definite limitations as to its general applicability. These
limitations are concerned primarily with the range of sand
particle sizes that can be fluidized without excessive
eiutriation. Additional experimentation is needed to further
delineate the range of potential application.
INTRODUCTION
The most serious threat posed by a major oil spill is the
potential damage it can cause to beaches and other
recreational shoreline areas. This damage can take many
forms, ranging from a high mortality to the usually
abundant marine life found in the intertidal zone, to
foregone recreational use. A recently completed study
brings out the magnitude of this damage. Mead and
Sorensenl have estimated that the total economic cost of
the Santa Barbara oil spill was $16.4 million. Two items
stand out in their analysis:
a) $4.9 million were spent for beach, harbor, and
property cleanup operations.
b) the value of lost recreational use during the
12-month period .following the oil spiff was esti-
mated to be $3.1 million.
Thus, nearly 50% of the total cost of the Santa Barbara ofl
spill may be directly attributed to beach and shoreline
contamination.
In the face of this magnitude of costs, the need to
develop a combatant technology that will keep the oil from
coming ashore is obvious. Also required, however, is an
effective method to deal with the beach contamination
problem directly. For, even if a /working cohtain-
ment-recovery system were available, some of the oil could
still come ashore. Furthermore, the amount of these
contaminants could be very large, since there is a sub-
stantial likelihood that time and logistic considerations
would prevent the necessary early deployment of open sea
combatant devices. This relative certainty of beach con-
tamination, coupled with the primitive techniques currently
in use, thus provides considerable incentive for developing
new and better treatment methods.
Additional stimulus is provided by the fact that
cleanup methods currently in use often result in the loss of
large quantities of valuable sand. This factor assumes
special, and sometimes crucial, importance in the case of
shorelines where encroachment of man-made marine struc-
tures or interference caused by jetties, breakwaters, etc. has
upset the natural sand supply processes. In these instances a
"cleaned" beach will have little recreational value unless the
sand is also restored.
During the past few years, a number of methods for
the in-place restoration of oil-contaminated beaches have
been proposed.^ These methods employ various processing
schemes and may conveniently be categorized as either
533
-------
534 OIL SPILL CLEANUP
thermal, physical, chemical, or biological in nature. In this
paper, we describe some preliminary results of a physical
processing technique — the mechanical removal of oil from
sand by means of hot water washing.
HOT WATER PROCESSING
The basis for a hot water processing scheme lies in the
fact that sand is an inorganic material and is therefore
preferentially wetted by water rather than by oil. Under
ambient temperature conditions, oil adheres to sand par-
ticles by a combination of surface and viscous forces.
However, when an oil-coated sand particle is placed in a
high temperature aqueous medium, these forces are sub-
stantially reduced. Since there is a basic absence of
attractive forces between the oil and the hydrophilic
surface of the sand particle, the oil separates and rises to
the water surface while the sand, by virtue of its higher
density, sinks to the bottom.
In addition to its basic conceptual simplicity, optimism
for this approach to cleaning oily sand is provided by the
commercial use of a similar process for recovering oil from
the Athabasca Tar Sands in Alberta, Canada. These tar
sands consist of viscous hydrocarbons (called bitumen)
trapped in a matrix of day and loosely consolidated
sandstone. Hydrocarbon content ranges from about 3 to 18
percent. Although details of the commercial hot water
process are not important here, there are several factors
which distinguish it from a potential beach cleaning
application.
The principal goal in the Athabasca operation is to
recover a pure grade of bitumen, i.e., a hydrocarbon phase
which is free of all entrained sand and clay particles. This
purity requirement necessitates a complex processing
scheme which involves conditioning, screening, primary and
secondary froth flotation, settling, and centrifugation.
Further complexities are introduced by way of economic
constraints, principally in the form of minimum water
usage.
By way of contrast, the focal point of a hot water
beach cleaning operation is the sand and not the oil, i.e.,
the condition, or solids content, of the recovered oil is
irrelevant and immaterial (at least in principle). Further-
more, the oil-sand mixture is much easier to separate
because, unlike the consolidated Athabasca sands, beach
sand is free flowing. Thus, the processing complexities of
the Athabasca operation are not necessarily indicative of
the requirements for an effective beach cleaning operation.
The physical separation of oil from sand by hot water
washing is inherently a two-step operation — stripping and
oil recovery. From the viewpoint of developing a workable
process, the first step offers the greatest latitude for
innovation. Whatever method or technique is selected, the
output from the first step will be an oil-water mixture
which can .then be treated by well established procedures to
recover the ofl. We, of course, qualify this delination of the
problem by stating that a prime criterion for judging the
suitability of the first step is that the oil-water effluent be
amenable to standard treatment, i.e., a non-emulsified
mixture.
The method we have investigated for stripping oil from
contaminated beach sand is hot water fluidization. The
process consists of feeding oily sand to the top of a liquid
fluidized bed contactor and adding hot water at the
bottom. As the sand slowly sinks through a rising column
of hot water, oil is stripped off and rises to the surface
where it is taken off to an oil-water separator. Clean sand in
slurry form is removed from the bottom of the contactor.
Potential advantages of this method are:
1. Reliability — there are no moving parts (agitators,
etc.) which can suffer mechanical breakdown.
2. Ease of ofl recovery — the low hydrodynamic
velocities required for fluidization result in minimal
ofl emulsification.
3. Portability — the anticipated physical dimensions of
a fluidized bed contactor, are such that the unit can
easily be transported to the site of an ofl spill.
The work described in this paper was conducted by
students in the Department of Chemical and Nuclear
Engineering at the University of California, Santa Barbara
and represents a preliminary evaluation of the hot water
fluidization concept. The principal technical objectives
were: 1) examine conceptual feasibility, and 2) define the
major design problems which would have to be solved in
order to conduct a thorough technical investigation.
DESIGN
The Overall Process
Groundwork for the design of a hot water process to
clean oily beach sand was laid by a group of chemical
engineering students in the Spring of 1969. This effort was
prompted by the January, 1969 ofl spfll in the Santa
Barbara Channel and was undertaken as part of the senior
course in chemical engineering design. Although the original
study was only a "paper" analysis, the results were
sufficiently optimistic to stimulate the following year's
students into undertaking an experimental pilot operation.
On the basis of results from the original student investiga-
tion, as well as guidelines provided by a Request for
Proposals issued by the Federal Water Pollution Control
Administration, the following design criteria were estab-
lished:
a) The process should make maximum use of readily
available sea water.
b) A continuous process would be preferable over
batch-wise operation.
c) The mechanical design should be as simple as
possible to insure reliability.
d) Physical size should be small enough to permit easy
transportation both to and at the site of an ofl
spfll.
e) Hardware configuration should allow for ease in
deployment and on-site setup.
f) Process energy demands should be minimized.
-------
HOT WATER FLUIDIZATION
535
BELT
CONVEYOR
OILY
SAND
LIQUID
FLUIDIZED BED
CONTACTOR
OIL-WATER
OVERFLOW
RECOVERED
OIL
MAKE-UP
tCLEAN SAND
SLURRY
Figure 1: Process Flow Diagram of the Hot Water Fluidization
Concept.
While these objectives were considered to be essential
for actual prototype operation, the extent to which they
could be realized in the pilot test study was limited by
funding and available student time. The design and subse-
quent testing, therefore, reflect these practical constraints.
The processing method which was selected for accom-
plishing the hot water wash is shown schematically in
Figure 1. Oily sand is transferred by means of a belt
conveyor to the top of a liquid fluidized bed contactor.
The nominal design feed rate was 20 cubic feet or about
one ton (dry basis) of sand per hour. At the bottom of the
contactor, hot water is added at a rate sufficient to
maintain the sand in a fluidized state. The nominal water
rate is 5 gallons per minute and the temperature is about
200°F. A clean sand slurry is removed from the bottom of
the contactor through a diaphragm valve and can be
transported hydraulically to a suitable storage area for
subsequent redistribution.
At the top of the contactor, the stripped oil and excess
fluidizing water are taken off through an overflow line and
pass, by gravity flow, to an oil-water separator. The flow
rate of oil-water effluent to the separator depends on the
amount of water required to generate a slurry at the
bottom of the contactor but is nominally in the range of 2
to 3 gallons per minute. The temperature of this stream is
approximately 160°F. The separator, in principle, can
operate either by continually removing the recovered oil or
by accumulating the oil for periodic batch removal. In
order to provide heat economies, clarified water is with-
drawn from the separator and is pumped back to the
contactor. Make-up water is added, either to the separator
for temperature and liquid level control purposes, or
directly to the recycle water line.
While many alternatives were available for providing
heat energy to the process, direct addition of live steam was
selected on the basis of simplicity, both from the stand-
point of hardware design as well as operability. The steam
sparger design consisted of a capped 3/4-inch pipe, with
1/16-inch diameter drilled holes, mounted concentrically
within a two-foot length of 2-inch diameter pipe. A
3/4-inch pipe was also used for the water inlet and outlet
connections.
For the process flow rates described above, the input
energy requirements are in the range of 3000 to 5000
BTU/min.. depending on water recycle ratio and heat losses
to the ambient surroundings. With input steam at 95 psig,
this sparger system was found to be very effective (although
noisy) in maintaining the desired operating temperature.
The heated water from the sparger is then sent to the
bottom of the contactor, thus completing the processing
scheme.
The entire processing system was mounted on a heavy
duty skid which, in principle, could readily be transported
to any desired beach location. A photograph of the system
in its final configuration is shown in Figure 2. The large
hurdle-type brace shown in this photograph was used to
support the conveyor and is not part of the processing
system. The horizontal pipe in the lower right hand section
is the clean sand slurry pipe.
Figure 2: Photograph of the Scale Model Hot Water Fluidization
System.
-------
536 OIL SPILL CLEANUP
Hie Fluidized Bed Contactor
The heart of the process shown in Figure 1 is the liquid
fluidized bed contactor. Fluidization is a well known
phenomenon which occurs when a fluid (gas or liquid)
passes upwards through a bed of solid particles. At low
rates of flow, the fluid merely percolates through the void
spaces between the stationary particles. The pressure drop
across the bed is directly proportional to the flow rate and
the bed is termed "fixed". As the flow rate is increased, the
solid particles move apart somewhat and become rearranged
so as to offer less resistance to the flow of fluid. In this
state, the voidage is increased and the bed is termed
"expanded." This process of bed expansion continues with
increasing flow rate until a point is reached when the
particles all become freely suspended in the upward flowing
gas or liquid. At this point, the fractional drag force
between the particle and the fluid just counterbalances the
weight of the particle. In this state, the bed is considered to
be incipiently "fluidized" and the pressure drop across the
bed is approximately equal to the weight of the fluid plus
the weight of all the solid particles. Further increase in fluid
velocity causes still further bed expansion but the pressure
drop remains nearly constant and independent of the flow
rate. In essence, the bed of solids has been "rendered fluid"
and its properties are, in many respects, equivalent to those
of a dense, viscous liquid.
While many factors govern the behavior of fluidized
beds3,4, a detailed analysis of Jhe complexities of this
behavior is beyond the scope of our study. We, instead,
focus attention on those aspects of fluidization which are
significant in the design of a device for cleaning oily beach
sand. In this regard, the major advantages are:
a) Intimate contact between sand particles and fluid
which, while highly efficient, is sufficiently gentle
to minimize fee pendency to form oiHn-water
emulsions.
b) Relatively low power requirements to achieve the
necessary fluid-solid contact
c) Fluid-like behavior of the sand bed simplifies the
mechanical problems associated with solids handling
and transfer.
On the other hand, its disadvantages include:
a) A tendency for rapid mixing of solids in the bed
and nonuniform residence times which .can lead to
contamination of the "dean" sand effluent.
b) Difficulties in maintaining a uniform state of
fluidization when the input sand has .a broad
particle size distribution.
Details of the liquid fluidized bed contactor design are
shown schematically in Figure 3. The unit consisted of a
column, one foot in diameter by six feet in height. Oily
sand was admitted through an input cone (included angle of
60°) fitted to a 15-inch length of 5-inch diameter pipe. The
feed pipe extended into the freeboard zone of the
contactor, thus permitting oily sand to be introduced in the
approximate vicinity of the fluidized bed interface. The
oil-water overflow line was 1% inches in diameter — a
dimension governed more by potential plugging than by
flow rate requirements. Similarly, although not shown in
Figure 3, the input cone was fitted with a water spray ring
(0.5 gpm) to prevent sand from bridging the feed pipe.
The bottom of the contactor column was fitted with a
number of upward directed jets to provide hot water for
fluidization. These jets were of simple design and consisted
basically of check valves mounted on 3/4-inch pipe outlets.
The purpose of the check valves was to prevent clogging by
solids when the system was being shut down. In addition to
the fluidizing jets, a separate water stream was provided to
flush clean sand from the bottom of the column. The flush
line consisted of a perforated 3/4-inch diameter pipe which
extended to the apex of a 60° output cone. The cone was
fitted with a 2-inch diaphragm valve that was used to
control the output rate of clean sand from the contactor.
Although not shown in Figure 3, an auxiliary water line was
added downstream of the diaphragm valve to aid in
transporting the dean sand slurry to the location of
sand-water disengagement. The contactor was also equipped
with provisions for measuring temperature and pressure
profiles.
OILY SAND
I
INPUT CONE
OIL LAYER
.OIL-WATER
OVERFLOW
FREEBOARD ZONE
PRESSURE __
TAP -~
THERMAL
WELL
FLUIDIZED ZONE
FLUIDIZING JETS
1 INPUT
i WATER
FLUSH LINE
DIAPHRAGM VALVE
CLEAN SAND
SLURRY
Figure 3: Schematic Diagram of the Liquid Fluidized Bed Con-
tactor
-------
HOT WATER FLUIDIZATION 537
The Oil-Water Separator
The overhead effluent from the contactor consists of
oil, water, and entrained fine sand particles. The function
of the oil-water separator is to clarify this mixture to the
greatest extent possible — the oil phase going to disposal
jnd the water phase for recycle. Clarification of the water
phase is the most important function as this directly affects
the quality of clean sand effluent from the contactor. The
presence of entrained sand, however, complicates this
otherwise straightforward physical separation process.
Traditional methods for clarifying an oil-water mixture
are barrier separation (the equivalent of fluid-phase "filtra-
tion") and gravitational or centrifugal separation. With
regard to the present study, the effluent stream to be
separated ranged from 1 to 5 percent in oil content and, as
previously discussed, it was expected that this effluent
would be relatively "nondispersed" in nature. Therefore,
our design was based on the premise that gravity separa-
tion would yield a recycle water stream of sufficient clarity.
Gravity separation depends generally on the slip
Velocity of ofl drops relative to water as a result of the oil's
tower density. The slip velocity acts to displace oil upwards
relative to the water in the separator. This slip velocity is
fflustrated by Stoke's equation for the steady upward
velocity, u, of a sphere in an infinite fluid mediumS.
u = gD2 (p0 - pw)
(1)
In this equation, g is the gravitational acceleration, D is the
sphere diameter, p0 and pw are the densities of the (oil)
sphere and (water) medium, and v is the viscosity of the
water. While this equation is strictly applicable only to rigid
spheres, it illustrates the basic and significant features of
gravitational separation. Slip velocity (and hence, ultimate
separator clarification) increases according to the accelera-
tion field, density contrast, and drop size, and decreases
with increasing water phase viscosity, i.e., decreasing
temperature.
Under "normal" circumstances, the separation of an
oil-water mixture is favored by higher operating tempera-
tures, Le., the density contrast increases6 and the water
viscosity decreases. In the present study, however, the
situation is complicated by the presence of entrained sand
in the contactor effluent This sand acts to increase the oil
droplet diameter and drecrease the density contrast. At the
normally favorable high temperatures, however, ofl tends
to be stripped from the sand particles, thereby decreasing
droplet diameter. Since slip velocity is proportional to the
diameter squared, the exact effect of separator temperature
is therefore difficult to predict
The separator design used in this study consisted of a
standard 55-gallon drum fitted with appropriate instru-
mentation, piping, and valves as shown in Figure 1. Due to
the considerable uncertainty in anticipated performance,
provision was made to add a second stage separator (also a
55-gallon drum) if needed. The recirculation pump was a
centrifugal type delivering 30 gpm at 25 psi head. Flow
rates were measured by calibrated orifice meters.
TESTING
Testing was performed during late spring of 1970.
Initial efforts used only clean sand and were devoted to
obtaining calibration data-and verifying the performance of
items such as the steam sparger, diaphragm valve, fluidizing
jets, etc. While most components functioned as expected
(or were made to do so with minor modifications), two
potential problems were encountered:
a) plugging of various flow channels due to rocks,
debris, and other flotsam.
b) entrainment of fine sand particles in the overhead
effluent from the contactor.
As discussed in the previous section, the processing
unit was designed for in situ operation. While in this regard
the system is basically self-contained, it does have certain
auxiliary requirements. These are: 1) power, 2) steam, 3)
water, and 4) a conveyance system. From an operational
standpoint, the steam requirement presented the most
difficulties. Practical considerations, therefore, dictated
that testing be conducted near a laboratory that had a ready
supply of available steam. Unfortunately, this laboratory
did not have a convenient supply of sea water (which was
the preferred aqueous medium) and, therefore, fresh water
was used instead.
The use of fresh water imposed stringent demands on
the resulting performance. Efficient operation of both the
contactor and the separator depends directly on the density
contrast between ofl and the aqueous medium. For oils
used in this test (see Table 1), the substitution of fresh
water decreased this density contrast by 20 to 50 percent
over that which would be obtained with sea water.
Performance tests were conducted with a synthetic
mixture of ofl and local beach sand. In all test runs, the
mixture fed to the fluidized bed contactor contained an
average of one to two weight percent ofl. This feed mixture
was not uniformly blended and had pockets of substantially
higher ofl content as well as pockets of essentially clean
sand. The properties of the ofls used in the test runs are
presented in Table 1 and a grain size analysis of the beach
sand is given in Table 2. Except where noted, all test runs
were performed with the 23° API gravity crude ofl.
Table 1: Summary of Oil Properties
Crude Oil Residual Oil
Gravity, °API
Distillation, volume %
< 350° F
350 - 650° F
650 - 1025° F
>1025° F
Viscosity, centistokes
@ 60° F
@100° F
23
10.6
29.5
33.2
26.7
39
12
14
trace
15.7
53.2
31.0
500
160
-------
538 OIL SPILL CLEANUP
Table 2: Beach Sand Size Distribution
Particle Size, Inches Weight %
<.006
.006 - .010
.010 - .014
.014 - .020
>.020
5
48
39
7
1
Because of limitations on available time, all tests were
run at nominal design conditions and flow rates. The two
problems which were identified during preliminary testing,
i.e., plugging and entrainment, continued to be troublesome
during this stage of testing. In addition, it became readily
apparent that the oil-water separator was not performing as
desired. Performance was improved by the addition of a
second stage separator (the horizontal 55-gallon drum
shown in Figure 2) but still did not reach an acceptable
level. The basic problem was that dispersed oil in the
separator recycle stream was contaminating the "clean"
sand slurry from the bottom of the contactor. The only
solution found to be effective was to divert the contactor
effluent to a separate, isolated vessel and not recycle any of
water. Under these operating conditions, the effluent sand
slurry then contained very little observable oil.
Quantification of the cleaning ability of the hot water
fluidization process was determined by analyzing the clean
sand effluent for residual oil. The method used was a
modification of a colorimetric technique reported else-
where?. Briefly, it consisted of dividing a representative
sample of clean sand effluent into two weighed portions.
One portion was simply dried in order to convert measure-
ments to a dry sand basis. To the other portion, a known
amount of hydrocarbon solvent was added (commercial
paint thinner was found to be effective). After agitation
and settling, the hydrocarbon extract was decanted, placed
in a colorimeter, and the percent transmission of mono-
chromatic light was measured. By comparing this trans-
mittance to that of a suitably prepared and known standard
solution, the oil content of the sand sample could readily
be determined.
Results of these analyses showed that upwards of 95
percent of the oil was removed. Although the majority of
samples indicated a cleaning efficiency of 98 - 99 percent,
certain instabilities in the process operation resulted in
occasional samples that would register a somewhat higher
degree of oil content The 95 percent figure is therefore
believed to be a realistic, but conservative, measure of
cleaning efficiency for the hot water fluidization process.
Our original test schedule also called for operation with
a residual crude oil (see Table 1). The purpose of this test
was to simulate beach cleanup operations when dealing
with a highly weathered ofl, i.e., an ofl which had lost most
of its volatfles and had increased in density because of a
lengthy exposure to the marine environment. As expected,
the clarifying ability of the oil-water separator was signifi-
cantly worse when the contaminant was a residual crude.
Furthermore, the "clean" sand effluent contained sub-
stantially more oily contaminants even when the process
was operated without water recycle. This degradation in
performance was due to oil-sand agglomerates that were not
broken up during the downward passage through the
fluidized bed contactor. Because testing was limited,
however, the exact cause for this behavior could not be
ascertained.
DISCUSSION
As mentioned previously, the main technical objective
of this study was to examine conceptual feasibility of the
hot water fluidization process and define the major design
problems which would have to be solved in order to
conduct further studies. In this respect, it is appropriate to
examine some of the problems encountered during opera-
tional testing and assess their effect on the design of a
prototype test model.
The most pervasive problem appears to be the typically
broad particle size distribution of most beach sands. In
comparison with other studies**, the sand used in these tests
had a rather narrow grain size distribution. As this
distribution broadens, the problems become more severe.
In the first place, the grain size distribution has a direct
effect on the fluidization process itself. When the fluidizing
medium is a liquid, the relationship between minimum
fluidizing velocity and particle diameter may be approxi-
mated by Stoke's equation (see Eq. (1)). Each particle size,
however, also has a characteristic maximum fluidizing
velocity3. Therefore, an operating velocity (or flow rate)
must be chosen which is low enough so that fines are not
carried out the top and, at the same time, is great enough to
freely suspend the larger size particles. For the sand used in
these tests, the maximum velocity for fine grains was about
3 to 4 times the minimum for the coarse grains. This range,
of course, narrows as the size distribution broadens.
A second, but related, effect of particle size distribu-
tion concerns performance of the oil-water separator. The
responsible phenomenon is termed elutriation, i.e., the
selective removal of fines by entrainment from a fluidized
bed which contains a mixture of particle sizes. These fines
become intimately mixed with the oil droplets during
passage from the contactor overflow to the separator, and
drastically reduce the oil-water density contrast. In the
present study, this effect was accentuated by the use of
fresh water instead of sea water. Although a certain amount
of fines carry-over is unavoidable, the problem can be
minimized by proper design of the contactor freeboard
volume. Even with minimum carry-over, however, it may be
necessary to resort to barrier or centrifugal separation
techniques in order to obtain a water recycle stream of suf-
ficient clarity.
Another factor which affects cleaning performance is
the mechanism of sand flow through the contactor.
Fluidized beds are normally considered to have a high
degree of axial mixing and an associated broad range of
particle residence times. While this behavior accurately
describes a gas fluidized bed, an entirely different situation
-------
HOT WATER FLUIDIZATION 539
is possible with liquid fluidized beds. The ideal operating
mode for a beach sand cleaner (and, in fact, the mode
which was hypothesized in this design) is "plug" flow in
rwhich axial mixing of solid particles relative to the bulk
downward flow of sand is zero. Under these conditions, the
residence time is constant, and all particles are exposed to
the hot water wash for exactly the same length of time.
In actual operation, however, this situation does not
prevail, even in the case of liquid fluidization. Axial mixing
does occur and, if it is sufficiently large, some of the sand
particles will exit from the bottom of the contactor before
they are completely stripped of oil. The extent of axial
mixing (or nonuniform residence time) is dependent both
on column operating conditions and also on mechanical
design factors. With regard to the former, axial mixing
increases with increasing fluid velocity. Thus, problems can
be expected if a bed of widely varying particle sizes is to be
completely fluidized. In the matter of mechanical design,
the most important factor is the manner in which fluidizing
liquid is introduced and distributed across the bottom of
the column. Improper distributor design or faulty operation
can lead to channeling. While this phenomenon is different
from axial mixing, the end result is the same, i.e.,
insufficient contact between the wash water and oily sand.
The other problems encountered during operational
testing of the hot water fluidization model were basically
mechanical in nature. The major difficulties were associated
with plugging of various flow channels and inadequate flow
control of the clean sand effuent stream. Some of the
plugging problems may be attributed to the physical size of
the test model and others are amenable to solution by
suitable design, i.e., the use of traps, check valves, delump-
ers, etc. It is anticipated, however, that a full scale model
would require preliminary screening of the input sand to
remove large debris. With regard to the second mechanical
difficulty, improved flow control of the clean sand effluent
could most likely be obtained by using a slurry pump or
other appropriate hardware.
CONCLUSION
In conclusion, we judge the hot water fluidization
process for cleaning oil-contaminated sand to be technically
feasible and deserving of further study. Cleaning efficiencies
in excess of 95 percent are indicated and a rough scale-up
of the test data indicates that 20 tons of sand per hour
could be processed in a fluidized bed contactor 2 to 3 feet
in diameter by 10 to 15 feet in height.
On the basis of preliminary tests and theoretical
analysis, however, there appear to be definite limitations as
to the general applicability of a hot water fluidization
process. These limitations are concerned primarily with the
range or distribution of sand particle sizes that can be
fluidized without excessive elutriation. Additional experi-
mentation is needed to delineate these limitations.
ACKNOWLEDGEMENT
The following individuals assisted throughout the
course of this study: Steve L. Gleitman, Charles H. Hanson,
Paul A. Helman, David E. Farlow, Fahad A. Somait,
Bernard C. K. Chan, Frederick W. Thoits, and Joseph M.
Seda.
REFERENCES
1. W. J. Mead and P. E. Sorensen, "The Economic Cost of
the Santa Barbara Oil Spill," paper presented at the
Santa Barbara Oil Symposium, December 16-18, 1970;
Symposium Proceedings to be published by the Marine
Science Institute, University of California, Santa Bar-
bara.
2. "Combating Pollution Created by Oil Spills," Vol. 1,
Report to the Dept. of Transportation, U. S. Coast
Guard, prepared by A. D. Little, Inc., June 30, 1969.
3. D. Kunii and O. Levenspiel, "Fluidization Engineering,"
John Wiley & Sons, New York (1969).
4. "Proceedings of the International Symposium on Fluidi-
zation," A. A. Drinkenburg, ed., Netherlands University
Press, Amsterdam (1967).
5. "Chemical Engineer's Handbook," J. H. Perry, ed.,
McGraw-Hill Book Company, New York (1963).
6. 'Technical Data Book - Petroleum Refining," Am.
Petrol. Inst., New York (1966).
7. A. A. Allen, R. S. Schlueter, and P. G. Mikolaj, "Natural
Oil Seepage at Coal Oil Point, Santa Barbara, Cali-
fornia," Science, 170,974 (1970).
8. "Cleaning Oil-Contaminated Beaches with Chemicals,"
Report prepared for the Dept. of Interior, FWPCA by
the Northwest Region Research and Development Pro-
gram, Edison, New Jersey, August, 1969.
-------
THE STATE'S ROLE IN OIL SPILL CLEANUP
John D. Harper
Epro Oceanographic Institute
and
TheMarsan Corporation
Elgin, Illinois
ABSTRACT
With the policy of the Federal Government to respond
generally to oil and hazardous material spills beyond the
response capability of state and local governments, it has
become necessary for the Fifty States and other govern-
mental units to initiate measures whereby Strike Forces can
be deployed by the states to contain and recover the
numerous minor oil and hazardous material spills that in-
creasingly occur. Since the states and local governments
provide police and fire protection for their citizens, they
are now being asked to furnish a capable team of trained
personnel with necessary equipment to safeguard the en-
vironment, the marine in particular, from the abuses of
accidental oil and hazardous material spills.
The John Muir oil spill in Wausau, Wisconsin, in Octo-
ber - November, 1970, has shown how necessary it is for
assistance at the state or local government level to be
available for those spills not requiring federal or industry
response. It is recognized that the states and local govern-
ments are increasingly being burdened with fiscal responsi-
bilities in excess of revenues for the services they provide
their citizens. This could be one area where the Federal
Government could work in partnership with the state and
local governments by providing financial assistance.
A prerequisite in combatting an oil spill or the acci-
dental discharge of other hazardous materials into the
environment is, of course, to respond with a team of work-
ers experienced and knowledgeable in the subject of con-
tainment and recovery methods with the specialized equip-
ment necessary to perform the tasks at hand. These "Strike
Forces" are the first line of defense and can be compared to
other teams such as fire fighters, either municipal or in the
forest service, who actually perform the duties necessary to
conclude a successful operation. Where do the Strike Forces
come from? How many do we have? How well trained are
they? Must they be ad hoc groups hastily assembled on a
catch as catch can basis when a spill occurs? Must they be
almost exclusively in-house personnel of the offender aug-
mented with well meaning but untrained and non-directed
volunteers? What happens when the offender cannot
mobilize a Strike Force? These are questions easily asked
but not too easily answered. A Response Team of regula-
tory officials from all levels of government will, almost
without exception, examine an oil or hazardous material
spill to determine what remedial measures are necessary to
minimize the damage to the marine environment. But
where is the Strike Force to implement these recommenda-
tions?
A number of regional contingency plans have evolved
whereby provisions for a Strike Force to contain and
recover accidentally spilled oil are an integral part of the
operation. These are, by and large, federally and industry
orientated. The industry plans take the form of a coopera-
tive effort of terminal operators in liaison with the local
regulatory and harbor authorities.
Two excellent examples of this are the Portland Harbor
Pollution Abatement Committee Contingency Plan for the
state of Maine and the Louisville Area Industrial Mutual
Aid group that fields Strike Forces to work spills on the
Ohio River. Other cooperative groups have been formed
and are being formed, and it is anticipated that eventually a
veritable network of industry oriented Response Teams and
Strike Forces will be available to police their own activities.
Additional Strike Forces may be available depending upon
the geographic location of an oil spill by third party partici-
pants specializing in the contracting for containment and
clean up of oil spills. Third party contractors can provide a
valuable service by fielding Strike Forces where there is an
absence of a cooperative effort on the local scene, and the
nature of the spill is such that federal response is not called
for. The major disadvantage in the contracting for the clean
-------
542 OIL SPILL CLEANUP
up of an oil spill is the lack of assurances that can be given
on the degree of effectiveness of the methods, and whether
these same methods are accepted or not by the regulatory
agency having jurisdiction on the spill. Another factor that
third party contractors have to contend with is that of the
matter of economics. A Strike Force with all the attendant
equipment peculiar to its needs and the trained manpower
can be expensive, especially when working in the marine
environment ofttimes for long hours. Compensation for ex-
penses borne by a contractor in the performance of his
clean up operations are defensible if these costs can be
justified and are not exorbitant. Another matter is whether
or not it is a defensible position to assume that third party
contractors should be profit oriented while working a dis-
aster situation. All too often a Strike Force must be hastily
assembled as best it can from what is purportedly accurate
capabilities listed in regional contingency plans. Those who
have worked oil spills - either as a member of a Response
Team or on a Strike Force - know that there can be a wide
disparity between the number of personnel, equipment and
materials listed as available in a contingency plan and the
number that can be fielded to participate in an oil spill
dean up operation; and in some parts of this country, con-
tingency plans are nonexistent.
Recognizing that not only are Response Teams neces-
sary at the scene of an oil spill, but that Strike Forces are
imperative if the actual containment is .to be attempted and
the recovery is to be initiated, the Federal Government has
established the means through the U.S. Coast Guard and
the Environmental Protection Agency whereby Strike
Forces will become available to participate in major spills to
which there has been no local or regional response.
In the National Oil and Hazardous Materials Pollution
Contingency Plan it is stated that,
"The policy of the Federal Government is to respond
to -those situations which are beyond the response
capability of State and local governments and private
interests. Normally minor spills will be well within
the capability of non-federal resources and will not,
therefore, require a Federal response. Firm commit-
ments for response personnel and other resources
should be obtained from state and local govern-
ments."
Further, in the Water Quality Improvement Act of 1970,
Section 11, Control of Pollution by Oil, Subsection (c) (2)
it is indicated, in part, that..."for efficient, coordinated,
and effective action to minimize damage from oil discharges
(duties) shall include.).. .(A) coordination with state and
local agencies "
As much as it would be desired by some to place this
unhappy burden of cleaning up the nation's waterways
when oil spills occur solely upon the Federal Government,
it must be recognized by the states and municipal govern-
ments that this duty is viewed by the Federal Government
as the joint responsibility of the state and local com-
munities acting with federal agencies when a spill occurs.
While in the context of this paper the clean up of oil spills
is emphasized, we must, nevertheless, recognize that Strike
Forces should be equipped to deal with the accidental dis-
charge or spillage of hazardous materials including toxic
gases and chemicals and radioactive waste material. It is
imperative that consideration be given by the chief exe'cu-
tive officer and responsible legislators of the Fifty States,
the Commonwealth of Puerto Rico, the Virgin Islands, the
Canal Zone, American Samoa, and the Trust Territory of
the Pacific that provisions be made to immediately establish
well equipped Strike Forces to deal with the accidental
discharge of oil and other hazardous materials into the
environment. These Strike Forces of the states and local
governments could be a segment of the civil defense group
or could be a working arm of the Department of Natural
Resources or equivalent state agencies. Suggested state legis-
lation on the subject of oil discharge control has been
developed by the Council of State Governments of Lexing-
ton, Kentucky, and while patterned after the Maine statute,
may be of assistance to other legislative bodies desiring to
confront this problem.
What constitutes a Strike Force? For oil spill con-
tainment and recovery a minimum nucleus of ten men is
required that can be rapidly expanded by drawing upon
other state and local government departments for labor as
the situation demands. A ten-man Strike Force would in-
clude the Director of Operations and an Assistant Director
with eight men who would have the multiple capability of
operating vehicles, equipment and small boats. Each should
be licensed to operate VHP radio on the standard ship band
channels, as communication between different segments of
the oil spill control operation and merchant and other ves-
sels in the vicinity is of considerable importance. The Direc-
tgr and Assistant Director should be equally well versed in
the established procedures and operations for the control
and recovery of oily pollutants as well as having personal
characteristics suitable for the job. Only experience will
show that the Director of the Strike Force operations and
his assistant must be of an unflappable nature, not prone to
suffer under the pressures of his job. The Director and
Assistant Director should be equally qualified in estab-
lishing and maintaining liaison with the Response Team and
all of the regulatory agencies having jurisdiction on a parti-
cular operation. The Director of a Strike Force operation
assumes the responsibility for initiating to the best of his
ability and to the degree that the local situation dictates,
the most efficient and effective containment and recovery
operation! in j liaison j and upon consultation • with the
Response Team. His assistant is delegated to'keep the oper-
ation in action around the dock as is so often required in
working oil spills. Eighteen and twenty hour days are the
norm for these personnel and the scheduling must be such
that responsible authority, either the Director or his assist-
ant, is present continuously. The specialized equipment
needed by a Strike Force is still subject to some contro-
versy. The obvious tools are necessary and must be acquired
and these include the oil containment barriers, the smaller
boats, and tools, vehicles, and oil or sorbent removal
devices. One word of caution here is that there has been a
-------
THE STATE'S ROLE
543
great proliferation of hardware supposedly designed to
remove oil from the marine environment, some of it quite
costly. Unfortunately, the equipment's performance in
practice does not always bear out the public relations state-
ments issued on its behalf by its manufacturer. It is a case
of, "All that glitters is not gold." Those desiring to establish
a Strike Force would be well advised to take a hard long
scrutiny of equipment with alleged oil recovery capabilities
before making investments. It is hoped that eventually an
Evaluation Commission including government, industry and
academia members, will be established to offer guidance in
the selection of oil spill containment and recovery methods,
equipment and materials. Another word of caution is given
the matter of permitting "demonstrations" of equipment
and material by vendors during an oil spill recovery oper-
ation. Ofttimes the attention paid to a new or novel
approach may be out of proportion to that which is war-
ranted, and the primary task using accepted methods
suffers. It is not too much to ask of the vendors to work
the "bugs" out of their own equipment and materials on
their own time and not to compound the problems of the
Director of the Strike Force during an emergency oper-
ation. The Director should further fully protect himself
against backcharges or rental of equipment and materials
that he believes is being "demonstrated" gratis. It has been
known to happen that vendors try to collect for the trial
use of unproven equipment.
The Director of a Strike Force should be cognizant of
some of the more pressing legalistic problems associated
with working an oil spill. An example is the interference
with navigation through the deployment of oil containment
barriers. A blocked channel effectively closing off shipping
could result in demurrage assessments by a vessel against
the offender or the Strike Force attempting to clean up the
spill unless provisions are made to open and close the bar-
rier. This requires that an oil barrier blocking a channel be
manned around the clock with a boat and personnel having
the ability to communicate with the vessel desiring passage.
Frequently a double barrier is required across a channel,
one several hundred yards below the other, to permit this
locking through operation without the risk of losing the
pollutant. These barriers should be lighted for night time
visibility to the prescribed requirements of the U.S. Coast
Guard. The Director should be aware of the many legal
ramifications of an oil spill operation, including the lia-
bilities that can be incurred and be able to obtain expert
consul when the need arises. Environmental law is just now
emerging and almost every adjudication results in a land-
mark decision.
In any event, it is necessary firstly to have a Strike
Force and then to have it prepared to perform its functions
as that is seen to be.
An almost classic example of the lack of preparedness
that can exist at the state level in combatting an oil spill
occurred in Wausau, Wisconsin, last October. The John
Muir oil spill began on October 18 with the discharge
through heating system vent piping from the John Muir
Middle School of some- 2,000 gallons of No. 5 fuel oil into
the City of Wausau's storm sewer system. As is so often the
case, this happened on a weekend and at night and went
undetected for several hours. The fuel oil found its way
into the Wisconsin River through the storm sewer system
and was first reported by hunters on the Wisconsin River
and Lake Wausau to a Game Warden of the Department of
Natural Resources. The game warden, recognizing the ser-
iousness of the situation, attempted to learn the source of
the pollutant's entry into the river and notify local govern-
ment officials in the City of Wausau of the matter. The
early history of the oil spill revealed that Game Warden
Harry Borner had to be not only the Response Team, but,
with several of his men, also the Strike Force until such
time as the school district could mobilize manpower and
equipment to perform the clean up tasks. Only the coopera-
tion of Superintendent Burton of the Wausau School Board
and the efforts of Game Warden Borner averted what could
have been a much more serious impingement on the quality
of the marine environment of the Wisconsin River, Lake
Wausau and the Rib River. Mr. William Burton, Superin-
tendent of the Wausau School District, presented in a hear-
ing of the Division of Environmental Protection of the state
of Wisconsin testimony which said in part:
"When it became apparent to me that the responsi-
bilities associated with the cleanup of an oil spill
would be the duty of the Wausau Joint District No. 1,
I immediately requested expert assistance from those
knowledgeable in the field. The spill occurred on Sun-
day, October 18. Indecision reigned for some three
days, until Wednesday, October 21, it became
apparent that the School Board would have to, in the
absence of assistance from others, assume the respon-
sibility for the oil spill cleanup. The School Board
had manpower and equipment consisting of boats,
trucks, and certain containment booms. What we
needed was some direction from someone or some
agency that had experience in oil spill containment
and recovery."
The John Muri oil spill is a classic example of a number
of oil spills. All of the elements that are attendant in the
major disasters were present at the John Muir oil spill.
Some responsible officials recognized that considerable per-
sonal and cooperative effort would have to be made to
control and remove the oil. Others, unfortunately, did not.
The history of the John Muir oil spill is written into the
testimony presented to the Division of Environmental Pro-
tection of the State of Wisconsin on October 27, 1970.
The one lesson that it is hoped could be learned from
this spill, as with so many others, is the need for a state or
local government Strike Force that can initiate immediate
remedial measures when and where accidental spills occur.
What would be the cost of a state Strike Force? It
would necessarily vary depending upon a number of factors
including manpower requirements, equipment needs and
geographic area to be served. I would estimate an initial
budget of Five Hundred to Seven Hundred Thousand
Dollars plus an annual appropriation of Three Hundred to
-------
544 OIL SPILL CLEANUP
Five Hundred Thousand Dollars could produce a vialbe and
effective Stirke Force. Existing resources in men and
equipment of the state or local government'could very well
reduce these formidable amounts to something more
palatable. For example, the city of Wausau used a vacuum
truck perchased for catch basin cleaning and leaf removal
Operations to great advantage in their oil spill recovery
operations. An inventory of existing equipment with its
locations and availability would be of inestimable value in
equipping a Strike Force. Specialized containment and
recovery equipment would still most likely have to be
procured. Would the burden for this expenditure be solely
upon the taxpayer? Not necessarily. There are a number of
means whereby expenses incurred on a spill are recoverable.
If they were not, we would not see any third party
contractors in the business. It is not so much what the costs
are as to how much it pays in the benefits of protecting the
state's natural and water resources from degradation by
accidental ofl spillages. I would fully expect that while it is
the state or local governmental body's responsibility to •
field Strike Forces, financial assistance should be available
from federal sources. My belief in this is reinforced by
remakrs of Commissioner Dominick of the Water Qaulity
Office of Environmental Protection Agency in his address
to the Association of State and Interstate Administrators in
Portland, Oregon, on October 26, 1970. Here it was
indicated that the Federal Government believes cooperative
programs at all levels of government-a partnership based
on mutual respect in which all parties contirbute their best
efforts-will lead to a successful state-federal partnership of
water pollution prevention and control. Further, in the
stauts report of the FWQA, Clean Water for the 1970's it is
indicated that there is to be "better assistance to the
states." Whether or not these promises bear fruition and
federal assistance in the form of grants or other assistance is
made available, the states and many local governmental
bodies do have the responsibility and the duty, just as they
have in fire and police protection, to defend the quality of
their own resources, be they natural, marine, or mineral, for
the citizens of their state.
Those states that have already initiated planning to
contend with oil spills including the formation of Strike
Forces are to be commended, and it is hoped their exem-
plary efforts will be inspiration to other states requiring
similar programs. The states of California, Connecticut,
Florida, Maine, Massachusetts, Pennsylvania and Washing-
ton are singled Out as being particularly cognizant of the
necessity for state directed action in oil spill containment
and clean up operations.
My apologies to those I have inadvertently omitted
who have recognized the need for local action to safeguard
the environment and have taken steps to implement reme-
dial measures when the occasion demands.
REFERENCES
1. The National Oil and Hazardous Materials Pollution
Contingency Plan, June, 1970, US G.P.O.; 1970
0-398-938.
2. Federal Water Pollution Control Act, US Department
of Interior, US G.P.O. 1970 0-389-779. •
3. Clean Water for the 1970's, a Status Report, De-
partment of Interior, Federal Water Quality
Administration, US GP.O. 1970 0-398-880.
4. Ocean Dumping, a National Policy, a Report to the
President, prepared by the Council on Environmental
Quality, October 1970, US G.P.0.1970 0-404-547.
5. Oil Pollution, Report to the President, Department of
Interior - Department of Transportation, February,
1968, US G.P.0.0-298-767.
6. Oil and Hazardous Materials Contingency Plan for
Prevention, Containment and Clean Up for the State
of Maine, January 1970, Portland, Maine, Pollution
Abatement Committee, 04111.
7. 1971 Suggested State Legislation, Vol. xxx, Oil Dis-
charge Control, The Council of State Governments,
Lexington, Kentucky, 40505.
8. Testimony presented in the John Muir oil spill, Wau-
sau, Wisconsin, October 27, 1970, unpublished,
presented to Division of Environmental Protection,
Department of Natural Resources, State of Wisconsin.
9. An Oil Spill, We Profit by our Mistakes, Dick
Kloppenburg, October 23, 1970, Wausau Daily
Record-Herald.
10. No Silent Partners, unpublished, Remarks of David D.
Dominick, Commissioner Federal Water Quality Ad-
ministration, US Department of Interior, Address to
Association of State and Interstate Administrators,
Portland, Oregon, October 26, 1970.
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