EPA-600/8-82-010
June 1982
MANUAL OF PRACTICE
CHEMICAL TREATING AGENTS
IN
OIL SPILL CONTROL
by
Robert W. Castle, Carl R. Foget, and Eric Schrier
Woodward-Clyde Consultants
Three Embarcadero Center, Suite 700
San Francisco, California 94111
Contract No. 68-03-2621
Project Officer
Leo T. McCarthy, Jr.
Solid and Hazardous Waste Research Division
Oil and Hazardous Materials Spill Branch
Municipal Environmental Research Laboratory (Cincinnati)
Edison, New Jersey 08837
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
-------
DISCLAIMER
This report has been reviewed by the Municipal Environmental Research
Laboratory - Cincinnati, U.S. Environmental Protection Agency, and approved
for publication. Approval does not signify that the contents necessarily
reflect the views and policies of the U.S. Environmental Protection Agency,
nor does mention of trade names or commercial products constitute endorsement
or recommendation for use.
11
-------
FOREWORD
The U.S. Environmental Protection Agency was created because of
increasing public and government concern about the dangers of pollution
to the health and welfare of the American people. Noxious air, foul
water, and spoiled land are tragic testimonies to the deterioration of
our natural environment. The complexity of that environment and the
interplay of its components require a concentrated and integrated attack
on the problem.
Research and development is that necessary first step in problem
solution; it involves defining the problem, measuring its impact, and
searching for solutions. The Municipal Environmental Research Labora-
tory develops new and improved technology and systems to prevent, treat,
and manage wastewater and solid and hazardous waste pollutant discharges
from municipal and community sources, to preserve and treat public drink-
ing water supplies, and to minimize the adverse economic, social, health,
and aesthetic effects of pollution. This publication is one of the prod-
ucts of that research and provides a most vital communications link
between the researcher and the user community.
The purpose of this manual is to provide the On-Scene Coordinator
(OSC) with a systematic methodology consistent with national policy that
can be used to assess the case-by-case acceptability of oil spill treat-
ment using chemicals, and to determine appropriate application procedures.
Francis T. Mayo, Director
Municipal Environmental Research Laboratory
111
-------
ABSTRACT
The purpose of this manual is to provide the On-Scene Coordinator (OSC)
with a systematic methodology consistent with national policy that can be
used to assess the case-by-case acceptability of oil spill treatment using
chemicals, and to determine appropriate application procedures.
It contains guidelines for evaluating spill safety, determination of
relevant spill characteristics, prediction of treated and nontreated spill
movement, and criteria for comparison of probable impacts with and without
treatment. Dispersion of oil at sea, dispersion on the shoreline, and the
use of surface collecting agents are considered. The manual additionally
describes general chemical agent application procedures and dosage
regulation.
This manual is submitted as partial fulfillment of Contract No. 68-03-
2621 by Woodward-Clyde Consultants under the sponsorship of the U.S.
Environmental Protection Agency.
IV
-------
CONTENTS
Abstract
Contents
Figures
Tables x
Acknowledgment x^i
100 Introduction 100-1
101 Purpose 100-1
102 The National Contingency Plan 100-2
103 Use of Manual 100-3
200 Information Checklist 200-1
300 Spill Characteristics and Movements 300-1
301 Oil Classification 300-1
302 Slick Movement 300-5
303 Fire/Explosion Hazard 300-12
400 Criteria for Dispersion of Oil at Sea 400-1
401 Decision Rationale 400-1
402 Identification of Threatened Areas 400-3
403 Conventional Control and Recovery Potential 400-7
404 Oil Dispersibility 400-13
405 Selection of Application Technique,
Dispersant and Dosage 400-15
406 Movement of Dispersed Oil 400-23
407 Impact Comparison 400-41
500 Criteria for Dispersion of Oil on Shorelines 500-1
501 Decision Rationale 500-1
502 Conventional Protection and Cleanup Potential 500-3
503 Natural Cleaning Potential 500-4
504 Selection of Application Technique,
Dispersant, and Dosage 500-9
505 Ecologic Criteria 500-16
600 Criteria for Use of Surface Collecting Agents * 600-1
601 General 600-1
602 Environmental Criteria Controlling Use 600-2
603 Selection of Application Method and Dosage 600-6
-------
Appendices
A. Annex X A-l
B. Techniques for Dispersion at Sea B-l
C. Techniques for Dispersion on Shorelines C-1
D. Techniques for Use of Surface Collecting Agents D-l
VI
-------
FIGURES
Number Page
103-1 Chemical treatment of oil spills - decision process 100-4
301-1 Field identification of oil types 300-4
302-1 Volume, film thickness, appearance, and area
covered by oil spill 300-6
302-2 Vector addition for 10 km/hr NW wind and
0.3 km/hr north current 300-8
302-3 Maximum oil spill radius versus time 300-9
302-4 Typical evolution of slick surface 300-10
303-1 Decision guide - fire hazard and response 300-13
401-1 Decision guide - dispersion of floating oil 400-2
403-1 Assessment guide for mechanical control and
recovery 400-8
403-2 Windwaves at sea 400-9
403-3 Recovery rates of skimmers for different sweep
widths and vessel speeds 400-12
405-1 Product selection procedure 400-18
405-2 Product selection worksheet 400-19
405-3 Dispersant requirements at manufacturer's
recommended application ratios 400-21
406-1 Dispersed oil movement worksheet 400-24
406-2 Concentration of dispersed oil at 25 percent
dispersion effectiveness 400-27
406-3 Concentration of dispersed oil at 50 percent
dispersion effectiveness 400-28
vii
-------
Number Page
406-4 Concentration of dispersed oil at 75 percent
dispersion effectiveness 400-29
406-5 Concentration of dispersed oil at 100 percent
dispersion effectiveness 400-30
406-6 Dispersant concentration 400-31
406-7 Concentrations of dispersants in upper meter 400-32
406-8 Concentrations of dispersants in 3 meters 400-33
406-9 Concentrations of dispersants in 10 meters 400-34
406-10 Concentrations of dispersants in 30 meters 400-35
406-11 Maximum plume centerline concentration 400-38
407-1 Impact comparison matrix 400-42
407-2 Impact severity chart 400-46
407-3 Hypothetical spill event 400-52
407-4 Hypothetical spill event impact comparison matrix 400-53
501-1 Sequence for consideration of dispersant use on
shorelines 500-2
503-1 Shoreline energy levels 500-5
503-2 Natural cleaning potential for sediment shorelines 500-7
503-3 Natural cleaning potential for non-sediment type
shorelines 500-8
504-1 Decision guide - dispersant beach cleaning techniques
for sediment beaches 500-14
504-2 Decision guide - dispersant beach cleaning techniques
for non-sediment beaches 500-15
603-1 Collecting agent application 600-7
B-l Schematic of low pressure vessel spraying system -
full strength application B-4
B-2 Schematic for vessel spraying system - diluted
application B-5
Vlll
-------
Number Page
B-3 Schematic for high pressure vessel spraying system
using eductors to introduce dispersant B-6
B-4 Schematic for high pressure jet spray system B-7
B-5 U.S.C.G. foam eductor system B-9
B-6 Eductor rate versus dispersant discharged B-10
B-7 Vessel speed - dosage rate graph B-12
B-8 On-board helicopter spray system B-15
B-9 Bucket-type helicopter spray system ... B-17
B-10 Light agricultural aircraft spray system:
wind driven pump B-18
B-ll Light agricultural aircraft spray system:
hydraulic pump B-19
B-12 Pump output calculation nomogram B-22
D-l Surface collecting agent application speed guide D-3
-------
TABLES
Number Page
200-1 General Spill Information 200-2
200-2 Environmental Data 200-3
301-1 Spill Response Oil Classification 300-2
303-1 Flash Points and Flammability Limits of
Refined Petroleum Products 300-14
402-1 Special Features, Resources, and Uses 400-4
403-1 Checklist for Logistics of Containment and
Recovery Operations 400-10
404-1 Oil Type: Dispersant Compatability 400-14
405-1 Application System: Dispersant Type Compatability 400-16
405-2 Advantages and Disadvantages of Major Dispersant
Application Systems 400-17
405-3 Product Screening Criteria 400-20
406-1 Estimated Initial Mixing Depths 400-25
406-2 Typical Evaporation - Dissolution Loss 400-40
407-1 Criteria for "Severe" Impact Rating 400-43
407-2 Grades of Toxicity 400-45
407-3 Summary of Toxicity Data 400-50
504-1 Dispersant Type versus Substrate Type 500-10
504-2 Equipment and Application Methods for Different
Dispersant Types 500-11
504-3 Dispersant Beach Cleaning Techniques 500-13
-------
Number Page
602-1 Conditions Under Which Surface Collecting
Agents Are Effective and Are Not Effective 600-3
602-2 Checklist for Determining Feasibility of Using
Surface Collective Agents for Oil Containment
and Shoreline Protection 600-4
603-1 Application Techniques for Surface Collecting Agents 600-8
B-l Basic Vessel Application Systems B-2
B-2 Representative Aircraft Specifications B-14
C-l Water Base Dispersant Application Methods C-2
XI
-------
ACKNOWLEDGMENT
The authors wish to express their appreciation to Mr. James D. Sartor,
Mr. Martin Cramer, and Dr. David Liu of Woodward-Clyde Consultants, Environ-
mental Systems Division for their invaluable assistance and guidance in the
preparation of this manual.
We also gratefully acknowledge technical advice supplied by Dr. John
Frasier, Shell Oil Company; Mr. Gordon Lindbloom, Exxon Chemical Company; Mr.
D.E. Fitzgerald, Atlantic Richfield Company; Mr. Eric Cowell, British Petro-
leum Company; Mr. Sol Schwartz, EPA Region IX Technical Assistance Team; and
Dr. Royal Nadeau, EPA Emergency Response Team, for their review of the draft
report and helpful comments. Special thanks is given to Mr. Leo T. McCarthy,
Jr. who served as Project Officer for the Environmental Protection Agency.
XII
-------
SECTION 100
INTRODUCTION
101 PURPOSE
The major types of oil spill response actions include physical contain-
ment, mechanical recovery, and chemical treatment. Those actions resulting
in the actual recovery of the spilled material are preferred. However, such
actions are operationally limited to relatively calm conditions, localized
areas, and cases where there is minimal risk of fire or explosion. The use
of chemical treating agents (dispersants and surface collectors) expands the
range of operating conditions under which mitigating actions can be conduct-
ed, permits treatment of large areas, and reduces fire and explosion hazard.
This manual of practice is designed to provide a systematic methodology
for determining the acceptability of using chemical agents in the treatment
of oil spills. The methodology allows assessment of the threat or extent of
sensitive area contamination, evaluation of the relative impacts associated
with various response alternatives, and selection of appropriate application
methods.
100-1
-------
102 THE NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION CONTINGENCY PLAN
Developed pursuant to Public Law 92-500 (The Federal Water Pollution
Control Act), the National Oil and Hazardous Substances Pollution Contingency
Plan (NCP) provides a basis for ensuring efficient, coordinated, and effec-
tive action to minimize damage from oil and hazardous substance discharge,
including containment, dispersal, and removal. While advocating physical
control and removal of spilled oil, the NCP (Part 1510, Chapter V, Title 40,
The Code of Federal Regulations) provides a schedule for case-by-case utili-
zation of chemical treating agents and other additives. Known as Annex X,
this schedule is reproduced in Appendix A.
Annex X permits case-by-case consideration of chemical dispersion in the
following circumstances:
• In any case when, in the judgment of the federal On-Scene
Coordinator (OSC), its use will prevent or substantially reduce
hazard to human life or limb or substantially reduce explosion or
fire hazard to property.
• For major or medium discharges when, in the judgment of the on-scene
Environmental Protection Agency representative, its use will prevent
or reduce substantial hazard to a major segment of the population(s)
of vulnerable species of waterfowl.
• For major and medium discharges when, in the judgment of the
Environmental Protection Agency response team member in consultation
with appropriate state and federal agencies, its use will result in
the least overall environmental damage, or interference with desig-
nated water uses.
Annex X also permits case-by-case consideration of surface collecting
agent use under the following conditions:
• For all size discharges when its use will result in the least over-
all environmental damage or interference with designated water uses.
• For all size discharges when its use will provide a key element in
the most effective system for removing oil from the water environ-
ment .
Annex X requires submission of certain product and laboratory test data
prior to consideration of a product for field use. Data so submitted are
intended to provide information for case-by-case decision-making by on-scene
federal personnel.
The NCP further provides for certain technical, logistical, and scien-
tific support. This manual is designed to incorporate and utilize these pro-
visions and resources. As such, it is essential that the user of this manual
be familiar with the provisions, procedures, and restrictions of the NCP in
general and Annex X in particular.
100-2
-------
103 USE OF MANUAL
This manual provides the user with guidelines which enable case-by-case
assessment of the feasibility and acceptability of chemical agent use in the
control of oil spills in the marine environment. Figure 103-1 presents a
flow diagram illustrating the decision-making sequence and general organiza-
tion of the manual. Each decision point indicated represents one or more
subsections of the manual, which provide instructions on how to conduct a
specific evaluation or make a decision.
Section 200 contains field checklists which assemble information neces-
sary to access chemical treatment feasibility and application criteria, and
to compare impacts resulting from the available options.
Section 300 uses portions of this material to develop assessments
regarding spill characteristics and movement. It also provides criteria to
assess fire and explosion hazards. Use of chemical agents is acceptable to
the degree necessary to mitigate risk to human life, limb, or property with-
out further qualification.
Section 400, Criteria for the Dispersion of Oil at Sea, deals with
situations where shoreline contamination will not occur immediately. In
evaluating the acceptibility of chemical treatment, it provides criteria for
identification of threatened features or areas; assessment of control and
recovery potential using conventional techniques; evaluation of oil disper-
sibility; application techniques, dispersants, and dosage; prediction of oil
movement and characteristics; and comparison of the impacts associated with
dispersion versus those associated with conventional or no treatment.
Section 500 discusses the use of dispersants in treating shorelines
where oiling is imminent or has already occurred. It provides guidelines for
assessment of the probable adequacy of conventional protection and cleanup;
evaluation of probable natural cleaning processes; guidelines for the selec-
tion of agent, application technique, and dosage; and assessment of ecologic
factors.
Section 600 discusses the applications of surface collecting agents;
environmental factors which control their successful use; and the selection
of appropriate application methods, dosage, and supporting equipment.
A series of appendices is included to provide support information.
These appendices include:
Appendix A Annex X
Appendix B Techniques for Dispersion at Sea
Appendix C Techniques for Dispersion on Shorelines
Appendix D Techniques for Use of Surface Collecting Agents
100-3
-------
Spill information ^v
(200) )
K Environ mental
information
(200)
f Determine oil characteristics^
I and classification I
v" (301) y
C
c
Predict slick movements
(302)
Evaluate fire and
explosion hazard
(303)
Does spill present a
threat to human life
or limb, or explosion/fire
hazard to property'
O
O
Floating slick
(401)
Identify
threatened areas
(402)
Assess conventional
control and recovery
capability
(403)
^Surface collecting ^
-4 agents )-
\(600) (Appendix D)/
Chemical dispersion
acceptable as necessary
to control hazard
(404, 405, Appendix B)
Slick grounded
or grounding
imminent
(501)
Identify primary or
secondary threatened
areas
(402)
Assess conventional
control and recovi
capability
(502)
-\
'ery 1
Will control and
recovery actions
be adequate'
IMPLEMENT
Can environmentally
acceptable control and
recovery actions be taken'
-------
(Evaluate dispersibility ^
of oil 1
(404) I
c
Assess natural
cleaning potential
(603)
O
o
I
Ln
Is chemical dispersion
feasible?
Prepare to
treat on shore
(501)
Allow to
clean
naturally
Is natural cleaning
acceptable?
Select dispersant,
application, technique
and dosage
' (405)
'Predict movement and X
characteristics of '
dispersant and dispersed oil;
(406) J
^ ^
/ Select dispersant,
( application, technique
I and dosage
V '«*)
Evaluate impacts of
chemical dispersion
vs other treatment
(505)
^^^^^^^^^^^^^^^^^^^^^^
Compare impact of
chemical dispersion vs
no treatment
(407)
Chemical dispersion less
environmentally
damaging
Is chemical dispersion
less environmentally
damaging'
Prepare to
treat on shore
(501)
Chemical dispersion
acceptable
(Appendix C)
Chemical dispersion
acceptable
(Appendix B)
Figure 103-1. Chemical treatment of oil spills - decision process.
-------
SECTION 200
INFORMATION CHECKLIST
Evaluation of the acceptability of chemical agent use involves numerous
assessments requiring a variety of information. While many types of informa-
tion can be assembled for a geographic area prior to actual need, every spill
has its own combination of unique characteristics which can only be deter-
mined during the incident. Tables 200-1 and 200-2 are checklists designed to
facilitate collection of appropriate data.
Table 200-1 lists general information including time, location, volume,
and characteristics of the oil which can be used in estimating the extent of
the spill and its treatability. Meteorologic and oceanographic data are also
included to help predict spill movement and conventional cleanup potential.
Table 200-2 guides the collection of general ecologic data which are
necessary to identify possible threats and evaluation of impacts. Normally,
state and local officials and experts are available to contribute this type
of information. Their input may be particularly valuable in the identifica-
tion of local conditions, problems, and attitudes.
200-1
-------
TABLE 200-1. GENERAL SPILL INFORMATION
INCIDENT DATA
Apparent source:
Time and date: _
Location:
Is spill continuing? Yes No
Volume of discharge: Known (barrels)
Estimated (barrels)
Loss rate if continuing: (barrels/day)
Size and location of slick: (plot on chart)
Observed rate and direction of slick movement:
Oil type: A B C D (section 301)
Slick type: Continuous Windrows Other (specify)
Estimated average thickness:
Emulsification:
METEOROLOGIC DATA
Air temperature:
Wind: Speed Direction
Precipitation:
Visibility:
Forecast:
OCEANOGRAPHIC DATA
Water temperature:
Currents: Type Speed . Direction.
Sea state: 1 2 3 4 5
Average wave height (crest to trough): (m)
HYDROLOGIC DATA (near shore)
Wave height: (m)
irrents:
Tidal (ebb): Velocity
Tidal (flood): Velocity
Rlwk w/atpr-
Direction
Direction
Duration
Duration
(min)
Longshore currents: Velocity Direction
Tidal range: Rising Falling
Turbidity:
ADDITIONAL INFORMATION
200-2
-------
TABLE 200-2. ENVIRONMENTAL DATA
OFFSHORE AREAS
Sensitive Marine Resources
Waterfowl: Present Species Number
Marine mammals: Present Species Number.
Other (specify):
Commercial Use
Industrial (specify type, location):
Finfish (specify type, location): —
Shellfish (specify type, location):-
Other (specify type, location):
Recreational/Navigational use:
Other special features:
NEARSHORE/ONSHORE AREAS
Sensitive Marine Resources
Waterfowl: Present Species Number Nesting Area.
Marine mammals: Present Species Number
Estuaries:
Wetlands:
Coral reefs:
Rare, endangered, unique species/
associations (specify species/type):
Other (specify):
Commercial Use
Industrial (specify)
Finfishery:
Shellfishery:
Other:
Recreational Use
Harbors:
Recreational beaches/parks:
Boating:
Tourism:
Other (specify):.
200-3
-------
SECTION 300
SPILL CHARACTERISTICS AND MOVEMENT
301 OIL CLASSIFICATION
Petroleum can differ widely in its physical and chemical properties and
reactions when spilled in the environment or subjected to various types of
control actions. Weathering, emulsification, and other processes can further
alter the nature of the material with time. An understanding of the oil and
its probable reactions is necessary in predicting impacts and designing an
effective spill response.
The spilled material must be assessed as it reacts and changes in the
field. The following field classification groups oils into categories having
features common to both physical and chemical treatment. The four classes of
oil are:
• CLASS A: Low viscosity, high spreading rate oils
• CLASS B: Moderate or high viscosity, waxy or
paraffin-base oils
• CLASS C: High viscosity, low spreading rate, asphaltic
or mixed-base oils
• CLASS D: Non-spreading oils.
Table 301-1 summarizes representative oils, diagnostic properties, and
physical/chemical characteristics for each class.
Class A; Low Viscosity. High Spreading Rate Oils
This class typically includes light fuel oils and many light crude oils.
These materials are generally flammable when fresh. Class A oils can be
identified by high fluidity, clarity, rapid spreading rate, strong odor, and
high evaporation rate. They do not tend to adhere to surfaces and can usu-
ally be removed by flushing. Their tendency to penetrate porous surfaces is
high, and when incorporated in reducing substrates, Class A oils may be per-
sistent. When fresh, oils of this class can be considered highly toxic.
Class A oils tend to form unstable emulsions. Heavier Class A oils may
partially evaporate, leaving a residue that may fall into one of the other
response classes.
Class B; Moderate or High Viscosity Waxy Oils
This class includes medium to heavy paraffin-base oils distinguished by
a waxy or non-sticky feel. The oils of this class adhere to rock, plant and
other surfaces, but tend to be moderately removable by flushing. Their
300-1
-------
TABLE 301-1. SPILL RESPONSE OIL CLASSIFICATION
Field-Determined
Oil Type
Designation
Representative
Oils
Diagnostic Properties
Physical/Chemical Properties
00
o
o
I
Low viscosity,
high spreading
rate oils
Moderate or
higher viscos-
ity paraffin
base oils
High viscosity
low spreading
rate oils
Nonfluid oils
(at ambient
temperature)
Distillate fuel
and light crude
oils (all types)
Medium to heavy
paraffin base
refined and crude
oils; water-in-
oil emulsions
Residual fuel
oils; medium to
heavy asphaltic
and mixed-base
crudes; weath-
ered oil
Residual and heavy
crude oils (all
types); weathered
oil, water-in-oil
emulsions
Highly fluid, usually
transparent but can be
opaque, strong odor,
rapid spreading, can
be rinsed from surfaces
by simple agitation.
Moderate to high vis-
cosity, waxy feel, can
be rinsed from surfaces
by low pressure water
flushing.
Typically opaque brown
or black, sticky or
tarry, viscous, cannot
be rinsed from surfaces
by agitation.
Tarry or waxy lumps.
May be flammable, high rate
of evaporative loss of vola-
tile components, assumed to
be highly toxic when fresh,
tend to form unstable emul-
sions, may penetrate sub-
strates, respond well to
most control techniques.
Generally removable from
surfaces, soil penetration
variable, toxicity variable.
Includes water-in-oil emul-
High viscosity, hard to
remove from surfaces, tend
to form stable emulsions,
high specific gravity and
potential for sinking after
weathering, low substrate
penetration low toxicity
(biological effects due
primarily to smothering).
Will interfere with many
types of recovery equipment.
Nonspreading, cannot be re-
covered from water surfaces
using most conventional
cleanup equipment, cannot
be pumped without preheat-
ing or slurrying, initially
relatively nontoxic, may
melt and flow when stranded
in sun.
-------
tendency to penetrate permeable substrates is variable, and increases as
temperatures rise. Toxicity is variable depending on the percentage of
volatile components. When weathered or subjected to low temperatures, they
commonly become solid and fall into the Class D category. Water-in-oil emul-
sions (Mousse) which still flow, generally fit into this class.
Class C: High Viscosity. Low Spreading Rate Asphaltic Oils
This class normally includes residual fuel oils and heavier asphaltic
and mixed-base crude oils which are in the fluid state at ambient tempera-
tures. Characteristically viscous, sticky or tarry, and brown or black in
color, they generally adhere to substrates and resist removal by flushing.
After natural light ends and cutter stock evaporate, their toxicity tends to
be low. Biological effects are generally the result of smothering. The
ability to penetrate substrates is typically low. Many Class C oils have a
specific gravity near or exceeding that of water and may sink. Class C oils
will weather to a tar- or asphalt-like consistency and then may be considered
as Class D oils. The emulsions formed tend to be stable.
Class D; Nonfluid Oils
This class includes residual oils, heavy crude oils, some high paraffin
crude oils, and weathered oils that are solid or nonfluid at spill tempera-
tures. In solid form, they are essentially nontoxic. Class D oils may react
as Class A, B, or C at temperatures above their pour point.
Oil Identification
The criteria for field categorization of oil type are shown graphically
in Figure 301-1. The key diagnostic factors are described on the lower left
portion of the figure.
300-3
-------
Is the source
of the oil known?
No
Yes
Gather information
on quantity and
type of oil.
Is the oil
opaque?
Yes
Does the oil
feel waxy?
Yes
,, No
Is the oil in
solid chunks?
No
Yes
DEFINITION OF TERMS
OPAQUE: Cannot see through coating of oil.
WAXY: Feels slick but is not sticky,
can be easily wiped off fingers or hand with a cloth,
can be viscous.
SOLID OR Does not flow, can have solid
CHUNKY: consistency or be soft like putty.
STICKY Oil is very sticky and has a thick consistency,
OR it not easily removed from hands or fingers
VISCOUS: without using detergents or solvent.
Type 'C'
oil
Figure 301-1. Field identification of oil types.
300-4
-------
302 SLICK MOVEMENT
General
Slick movement prediction is necessary to determine the location of
potential shoreline and/or sensitive area contamination, and for direction of
response actions. Helpful data to predict oil spill movement are (listed in
order of importance): 1) surface current speed and direction, 2) wind speed
and direction, and 3) oil spreading characteristics. An accurate assessment
of spill volume is needed to determine cleanup equipment and chemical treat-
ing agent requirements. In addition, an understanding of the slick surface
behavior is important in the selection of control techniques and treatment
dosages.
Estimation of Spill Volume
Spill volume determines, in part, the amount of equipment, manpower and
other resources needed to execute the response. Because early estimates of
spill size are often unavailable or of questionable accuracy, first-hand en-
sile estimations are generally necessary. The following methods can provide
rapid working approximations:
• When tankers or oil barge casualties are involved, volumes can be
estimated if the cargo capacity and extent of hull damage are
known. Although the extent of hull damage and oil loss cannot
often be reliably estimated, total cargo capacity (by tank or ship)
can be useful in setting maximum spill size.
• If a spill occurs during oil transfer, the total spill volume can
be estimated if the pumping rate and the elapsed time between leak
occurrence and pumping shutdown are known. The maximum pumping
rate from the offloading source may be assumed to be the spill rate
for a complete transfer, hose rupture, pipeline or manifold fail-
ure. Spills resulting from improper flange makeup or from hose
leaks would be likely to occur at significantly lower rates.
• A rough estimate of spill volume can be calculated by considering
slick area and average thickness. Figure 302-1 relates the appear-
ance of oil on water to its thickness. These observations hold
true for spills less than about 0.25 mm thick. Because large
spills require significant time to spread to these thicknesses, a
direct measurement of slick thickness would be preferable early in
the spill.
Prediction of Spill Movement
The National Oceanographic and Atmospheric Administration (NOAA), under
the NCP, has the responsibility of providing marine environmental data to the
OSC. This data includes present and predicted meteorological, hydrological,
and oceanographic conditions for the area in question. NOAA has developed
computerized oil spill movement prediction models that can be used at the
request of the OSC to predict which shoreline areas or offshore amenities are
threatened by an oil spill.
300-5
-------
10 cm
1 cm
0.1 cm
0.01 cm
1,000,000
o
o
0.001 cm
0.0001 cm
0.00001 cm
AREA COVERED AFTER 24 HR (m2)
Shaded area indicates the range of oil slick
observations for which thickness and area
covered can be determined by appearance
Any value below the shaded area would
not be visible, and any value above would
be a dark brown or black
Figure 302-1. Volume, film thickness, appearance,
and area covered by oil spills.
-------
In the absence of sophisticated predictive modeling, on-scene personnel
can predict initial oil slick movements by vector addition of the two main
motive forces that apply: surface currents and winds. Observations from
actual spill situations have shown that wind will cause an oil slick to move
at between 0 and 4 percent of the wind speed, and in the same general direc-
tion. The exact percentage appears related to oil viscosity. For estimation
purposes, a factor of three percent is generally acceptable. Figure 302-2
gives an example of the vector addition method of oil slick movement predic-
tion. The general methodology for use of this technique is as follows:
1. Draw ocean current and wind component vectors in their relative
directions and lengths as shown in Diagram 1 (length of vector
represents velocity: 10 mm = 0.1 km/hr).
2. Draw a line parallel to the wind vector starting from the tip of the
current vector and measuring the exact length of the wind vector, as
shown in Diagram 2.
3. Draw a line from the point of origin (present oil slick position) to
the tip of the parallel wind vector line in Diagram 3. This final
line is the resultant vector which gives the direction and speed of
the oil slick movement. The direction can be measured by using the
cardinal points of a compass. The speed is determined by the length
of the resultant vector. The resultant vector can also be used to
estimate slick arrival time at points of interest along the path of
movement.
In cases where winds and currents are unknown or variable, aerial reconnais-
sance is a useful tool for supplying input to predictive estimates, and
tracking actual movements. Oil spills eventually cease to increase in size
if the spill source is stopped. In such situations, and when conditions are
calm, Figure 302-3 can be used to approximate probable spill radius. Calcu-
lations are based on a typical light crude oil (CLASS A) and may differ for
other oils.
Slick Characteristics
The preceding discussion assumes the surface distribution of oil within
a slick to be more or less uniform. While this assumption is adequate for
gross movement and volume estimation, actual slicks are rarely uniform.
Since the surface distribution of oil within a slick is important to treat-
ment selection, it is useful to understand some basic characteristics of
floating oil.
Figure 302-4 depicts the typical evolution of a larger slick. The
initial slick spread in Zone A is governed by gravity and inertial forces.
During this period the slick is relatively thick and its surface distribution
tends to remain continuous. As the initial spreading forces decrease and
such environmental factors as wind become important, windrow development is
common. Zone B indicates the zone of windrow development. In Zone C, addi-
tional exposure results in windrow breakup and formulation of "minislicks."
Typically the areas around and between minislicks and windrows are covered by
300-7
-------
1.
W-*
Current component - 0.3 km/hr
towards the north
10 mm = 0.1 km/hr
Present oil slick position
Wind component
3% of 10 km/hr from
the northwest
2.
3.
Figure 302-2. Vector addition for 10 km/hr NW
wind and 0.3 km/hr north current.
300-8
-------
16000
14000 -
Figure 302-3. Maximum oil spill radius versus time
(Fay-Hoult model).
300-9
-------
oi-ooe
-------
thin sheens. These sheens reflect differential spreading rates encountered
with some oils and the release of volatile fractions of more viscous oils.
If sufficient time and distance are available, a slick will ultimately
disappear in Zone C. If the slick movement is impeded, however, remaining
floating material may concentrate. This occurs commonly in response to the
presence of shorelines and coastal currents, and is shown on Figure 302-4 as
Zone D.
300-11
-------
303 FIRE/EXPLOSION HAZARD
The threat of fire and explosion is associated with marine oil spills.
The following rules should always be considered in the initial evaluation of
an oil spill:
• Until otherwise established, all oil spills - particularly those
involving gasolines or continuous spillage (pipeline breaks, well
blow outs, etc.) should be considered as fire hazards.
• Any spills (light refined products and light crude oil in partic-
ular) involving confined airspace in which vapors may concentrate
(shipboard tankage and machine spaces, under docks, etc.) should be
considered potentially explosive.
Chemical dispersants may be particularly useful in fire control and
reduction of fire and explosion hazard. In situations where such hazards
threaten human life and property, federal regulations allow the On-Scene
Coordinator to wave normal use restrictions and take immediate action.
Figure 303-1 is a decision guide to assist in the determination of hazards
and appropriate actions. As with any general guide, exceptions can exist.
Each case should be evaluated with utmost caution.
Fire hazard will normally diminish rapidly with time and distance from
the source. When in doubt, the potential fire hazard an oil spill presents
can be established by:
(1) determining flash point of the oil, or
(2) determining hydrocarbon vapor content of the air near the surface
of the slick by using an explosive gas detector
The flash point is the temperature at which the vapors rising from the
surface of the oil will ignite with a flash of very short duration when a
flame is passed over the surface. If the flash point of the spilled oil is
close to or below the ambient air temperature, the oil poses a fire hazard.
The minimum flash point and flammability limits for common refined petroleum
products are given in Table 303-1.
Prevailing weather conditions can affect the hazard potential of the
spilled oil. A calm, hot day could accentuate vapor buildup. Strong winds
(greater than 15-20 knots), on the other hand, will tend to disperse the
vapors below the flammability limit, considerably reducing the fire hazard.
In addition to the oil, flammability of the dispersant should be consid-
ered in the control of fire and explosion hazard. Hydrocarbon base disper-
sants should not be applied for control of fire hazard if nonflammable (water
solvent) types are available, nor should they be used in the vicinity of open
flame. Flash point data for EPA approved dispersants is given in the Annex X
data submissions.
300-12
-------
O
O
Is
material
burning'
Refined
Products
\
Crudes
Low Flash Point
High Flash Point
\
2
JJnconfmed
Confined
Confined
Continuous Discharge
Unconfmed
Yes
Is there a hazard to
life or is property
endangered?
(Consider areas of
potential spread)
No
-\
V
Evacuate area
Control spark sources
Ventilate
Allow to dissipate naturally
Proceed with conventional
actions
(consider burning)
Evacuate area
Control spark sources
Ventilate
Allow to dissipate naturally
Consider dispersion
to reduce hazard if
life/property theatened
Check vapor levels
Proceed with conventional
actions
Consider burning
Consider
chemical
dispersion
Allow to burn
Figure 303-1. Decision guide - fire hazard and response.
-------
Table 303-1. FLASH POINTS AND FLAMNABILITY LIMITS OF REFINED PETROLEUM
PRODUCTS
Aviation Gasoline
Automobile Gasoline
Naptha
Kerosene
Flash Point (°C)
-59.8
-57.0 + 52.0
-20.9
23.6 + 29.1
Flammable
Limits in Air
1. 27-7.17,
1.42-7.4%
0,.9%-6.0%
0.7%-5%
Jet Fuels:
JP-1
JP-3
JP-4
JP-5
23.6
29.1 + 51.3
-37.6 - -15.3
45.8
0.7-5%
Not Known
1.3%-8.0%
0.6%-4.6%
Diesel Fuels
ID
2D
Residual Fuel Oils
23.6
37.4
I ,,3-6.0%
1.3-6.0%
No. 4
No. 5
No. 6
>40.2
>40.2
>51.3
1-5%
1-5%
1-5%
Source: CHRIS, Hazardous Chemical Data, U.S. Coast Guard
CG-446, 1974.
300-14
-------
SECTION 400
CRITERIA FOR DISPERSION OF OIL AT SEA
401 GENERAL
This section provides a rationale for determining, case-by-case, the
acceptability of chemical dispersion of oil at sea. This rationale, pre-
sented graphically in Figure 401-1, consists of a series of basic questions.
Does the spill present a threat to shorelines or sensitive areas or ameni-
ties? If a threat is identified, is it probable that conventional control
and recovery actions will be adequate? Is the oil type dispersible, and can
an effective dispersion operation be implemented? Are the probable impacts
associated with dispersed oil less than those expected without such action?
The following subsections provide criteria for evaluating these basic ques-
tions .
400-1
-------
Are shorelines
or sensitive
areas threatened ?
(302, 402)
NO
o
o
N3
YES
Allow to
disperse
naturally
Are
conventional
control and
recovery
techniques
adequate?
(403)
Are
impacts
associated
with
dispersion
less than
with other
options ?
(406, 407)
YES
Dispersion
acceptable
Treat
onshore
Implement
Figure 401-1. Decision guide - dispersion of floating oil.
-------
402 IDENTIFICATION OF THREATENED AREAS
In Section 302 general slick movement is projected. Amenities in the
general path of movement including special features, resources, and uses that
are of particular biological, physical, or cultural importance can be iden-
tified and plotted. The relative importance of amenities in an area can vary
with the season, severity, and duration of the expected impact and potential
for recovery. Because of the high visibility of special features, resources,
and uses in an area, and of the limitations of time, manpower, and equipment
in responding to a spill, rapid identification of the amenities becomes a
critical part of the dispersant question. Local and regional experts can
provide necessary information on the nature and location of relevant environ-
mental concerns. In general, the probable effects of oil and oil dispersions
should be considered for the general amenities listed in Table 402-1. This
table also provides brief evaluation criteria.
400-3
-------
TABLE 402-1. SPECIAL FEATURES, RESOURCES, AND USES
1. Rare, Threatened, Endangered, or Protected Species
• Any species on federal or state special status lists.
• Relatively few expected in marine areas, some in estuaries, most
infresh water.
• Sensitivity will depend on the reason the species uses the aquatic
habitat, duration of use, importance of the habitat to successful
completion of the species life cycle, and public and political-
concern for the species.
• In general, sensitivities in decreasing order are: 1) resides in
aquatic habitat and completes whole life cycle in one place, 2)
habitat essential for breeding purposes, 3) habitat essential for
feeding purposes, and 4) habitat essential for resting and other
intermittant uses.
2. Reserves, Preserves, and Other Legally Protected Areas
• Areas protected by some legal mandate or areas locally recognized as
important for scientific or ecological reasons.
• Areas of special biological significance.
• Ecological preserves.
• Wildlife'and/or waterfowl sanctuaries and refuges.
• Scientific research areas.
3. Waterfowl Rookery or Concentration Areas
• Shoreline areas (rookeries) used for breeding, nesting, and fledging
activities.
• Open-water areas (concentration) used for resting, feeding, and
breeding
• Sensitivity will depend on which species are present; number,
extent, reason for use of the habitat; and susceptibility to oil
impacts.
• In general, sensitivities in decreasing order are: 1) diving ducks,
2) swimming and surface-feeding waterfowl, 3) gulls, terns, etc.,
4) shorebirds and 5) water-associated birds.
400-4
-------
TABLE 402-1 (Continued). SPECIAL FEATURES, RESOURCES, AND USES
4. Mammal Rookeries, Calving Grounds, and Concentration Areas
• Sensitivity will depend on which species are present; number,
extent, reason for use of the habitat; and susceptibility
to oil and dispersion impacts.
• In the marine environment, rookeries, and calving grounds are
generally more sensitive to oil impacts than are concentration
(haul-out) areas.
5. Species of Commercial Importance
• Clams and oysters.
• Crabs, shrimp, lobsters.
• Finfish (including spawning areas offshore, intertidal, and in
shallow streams).
• Algae.
• Aquaculture sites (shellfish, algae, finfish, lugworms etc.).
• Fish bait (lugworms, clams, ghost shrimp etc.).
• Sensitivity will depend on season, economic value of the local
harvest to the area, and susceptibility to oil and dispersion
impacts.
6. Species of Recreational Importance
• Clams, oysters, mussels.
• Crabs, shrimp, lobsters, ghost shrimp, lugworms, etc.
• Finfish (shoreline fishing areas, spawning areas for grunnion, salmon,
bass, and other fish).
• Abalone.
• Sensitivity will depend on season, use, and susceptibility to oil and
dispersion impacts.
7. Ecologically Productive Areas
• Eelgrass beds.
• Marshes and other wetlands.
400-5
-------
TABLE 402-1 (Continued). SPECIAL FEATURES, RESOURCES, AND USES
• Estuaries.
• Coral Reefs.
• Mangroves.
• Some kelp beds.
• Areas critical to survival of local population of species known to be
of major ecological significance in structure, function, stability,
and survival of the aquatic community.
8. Areas of Beach Stabilizing Vegetation
• Vegetation stabilizing sand dunes important to protecting backshore
areas.
• Vegetation preventing shoreline banks from erosion.
9. Areas of Geological Significance
• High erosion potential areas.
• Specially designated geological study areas.
• Fossiliferous formations.
• Mineral-bearing sediment deposits.
10. Areas of Recreational Significance
• Marinas and boat harbors.
• State parks and beaches.
• Sunbathing, surfing, and swimming beaches.
• Beaches with shore-front homes.
• Beaches with shore-front hotels and restaurants.
• Beaches adjacent to roads and highways.
11. Areas of Commercial or Industrial Significance
• Cooling water intakes.
• Process water intakes.
400-6
-------
403 ASSESSMENT OF CONVENTIONAL CONTROL AND RECOVERY
Federal policy advocates physical control and recovery of spilled oil
using conventional techniques (i.e., booms, skimmers, etc). The adequacy of
physical control and recovery of an oil spill at sea is dependent on a vari-
ety of factors including:
• prevailing meteorological and oceanographic conditions
• physical properties of the spilled oil
• availability of suitable oil spill control and recovery
equipment
The decision guide (Figure 403-1) illustrates how these factors can be
evaluated to determine the feasibility of containing and cleaning up an oil
spill at sea.
Sea State Conditions
The first factor to consider is the prevailing and predicted meteorolo-
gical and oceanographic conditions, which can be expressed as sea state.
Figure 403-2 illustrates how sea state can be estimated from wind speed and
wave heights. It also indicates the limitations of containment booms and oil
skimmers for various sea states. Generally, even containment booms and skim-
ming equipment rated for open sea conditions quickly lose effectiveness once
sea state 3 is surpassed. Therefore, if a sea state of 4 (i.e., breaking
waves over 5 feet) or greater is present and predicted for several days,
mechanical containment and cleanup techniques would be of limited effective-
ness or ineffective in controlling the spill.
Oil Properties
Skimmer recovery is affected by the physical state of the oil. High
viscosity and nonflowing oils are more difficult to recover and can consider-
ably reduce a skimmer's effectiveness.
Logistics
The availability of sufficient equipment and response time for implemen-
tation comprises the final assessment factor. A checklist for determining
the feasibility of containment and skimming operations is given in Table
403-1. If the answer to all questions is affirmative, then booming and skim-
ming operations should be feasible. If one or more answers are negative, the
physical control of the spilled oil might not be totally effective, and con-
sideration is given to other alternate or supplemental techniques (i.e.,
chemical treatment).
The length of boom needed to contain a fresh oil slick at sea is depen-
dent on the time required for its deployment and the volume of oil spilled.
As a slick spreads and thins out on the water surface it tends to break into
long narrow windrows in response to wind and wave conditions. This action
greatly increases the slick perimeter and consequently the amount of boom
needed for containment.
400-7
-------
Are present and/or predicted
sea state conditions greater
than sea state 3 ?
Determine Type of Oil
1. Light Distillate
Fuels
2. Low-Medium
Viscosity Distillates
and Crudes
Skimming operations
normally effective
Evaluate adequacy
of containment and
skimming operations
1. High Viscosity
Distillates and
Weathered Crudes
2. Nonspreading Oils
Skimming operations
only partially effective
Mechanical cleanup and
control equipment will
not be effective.
Examine dispersant
applications
./ \
if not 100% adequate
Figure 403-1. Assessment guide for mechanical control and recovery.
400-8
-------
o
1
VO
*
1. WIND VELOCITY (knots) 4
2. BEAUFORT WIND
AND DESCRIPTION
1
Air
I I
5 6
I I
2
as.
I I
7891
I I
3
0
4
Moderate
Breeze
I
5
I
20
|
Fresh
Breeze
3. REQUIRED FETCH (miles) Fetch is the number of miles a given
wind has been blowing over open water.
4. REQUIRED WIND DURATION (hours)
Duration is the time a given wind has ,
been blowing over open water.
I
I
5 20
I
|
200
I
I
i
30
6
Strong
Breeze
|
7
Mod-
erate
Gale
300
4
8
Fresh
Gate
I
I
0 50 60
I
9
Strong
Gale
10 ,..
W,hole Storm
Gale
I
400 500 600 700
25
I
If the fetch and duration are as great as indicated above, the
following
wave
will exist. Wave heights may be up to 10% greater if fetch and duration are
5. WAVE HEIGHT - CREST TO TROUGH (feet)
6. SEA STATE AND DESCRIPTION
1
1
Smooth
4
WhitP
2 Caps
Form
2 3
Slight Moderate
I
6 8
I
4
Rough
I
10
I
5
Very
Rough
I
I
30
I
I
I
35
I
conditions
greater.
I
15
I
20
6
High
I !
25 30
| |
I I
40 50 60
7
Very High
| |
8
Precipitous
•« — Small skimmers and booms with freeboard less than 16" — ^s.
Large skimmers and booms ^^
Note' Corresponding values lie on a vertical line.
This table applies only to waves generated by the local wind
and does not apply to swell originating elsewhere.
WARNING: Presence of swell makes accurate wave observation
exceedingly difficult.
NOTE: a. The height of waves is arbitrarily chosen as the height
of the highest 1/3 of the waves. Occasional waves
caused by interference between waves or between
waves and swell may be considerably larger.
b. The above values are only approximate due both to
lack of precise data and to the difficulty in expressing
it in a single easy way.
Figure 403-2. Wind waves at sea.
-------
TABLE 403-1. CHECKLIST FOR LOGISTICS OF CONTAINMENT AND RECOVERY OPERATIONS
Containment or Protection Yes No
1. Is there sufficient length of boom(s) available for
use (Length needed - approximately 60% of the
perimeter of the oil slick or slicks or 125% of
perimeter of area to be protected)
2. Are vessels and crews available to transport and
deploy boom
3. Can the boom(s) be deployed before the slick con-
tacts shoreline (Compare ETA of oil on shore with
estimated deployment time of booms)
Recovery
1. Are skimmers available which can operate under
open sea conditions
2. If so, is the combined pickup rate of the
skimmers sufficient to pick up most of the oil
in a reasonable time*
3. Is there sufficient storage available for the
skimmers to offload recovered oil without dis-
rupting or delaying the skimming operations
*If the discharge is continuous, can the skimmers pick up the oil volume
discharged daily, or if the discharge is of short duration, can the
skimmers pick up the spilled oil in 10 to 15 days.
400-10
-------
The areal extent and thickness of an oil slick is important in deter-
mining the number of skimmers needed for recovery operations. The amount of
oil a skimmer encounters during a skimming operation is the primary factor in
determining recovery rate. Many large ocean skimmers are capable of pumping
6,000 to 10,000 gallons of oil per hour; however, that large a volume of oil
would rarely be encountered.
Figure 403-3 can be used to estimate the encounter rate of a skimmer
with a known sweep width and skimming speed for various surface concentra-
tions of oil. The encounter rate multiplied by the skimmer efficiency gives
an estimate of oil recovery. For instance, if a skimmer with a sweep width
of 20 feet was operating in a 0.1 mm oil slick at a skimming speed of 2
knots, it would encounter approximately 600 gallons of oil in one hour. If
the skimmer has a recovery efficiency of 90 percent (i.e., it recovers 90
percent of the oil it encounters) it would pick up approximately 540 gallons
of oil per hour. The encounter rates do not reflect any time lost for manu-
vering, offloading of recovered oil or transit time to an offloading site.
Therefore, when estimating skimmer recovery rates only the actual time spent
in skimming should be used to determine an expected daily recovery rate.
Partial Effectiveness
In many cases conventional control and recovery techniques may be lim-
ited to certain parts of the spill due to adverse conditions or the sheer
magnitude of the spill. In this event, both chemical treatment and conven-
tional techniques should be considered to provide maximum overall effective-
ness and minimum damage.
400-11
-------
10.0
5|S
Ikt
2kt
3kt
4kt
5kt
11,000
20 SO 100 200300 500 1.000
40 100 200 4006001,000 2.000
6O 150 300 6009001,500 3,000
80
400 800 1,200 2,000 4,000
-U
100 250 500 1,0001.5002,5005.000
GALLONS PER HOUR
10,000
20,0190
30.000
40,000
50,000
1,100 5
IE
LU
O
u.
O
O
-110
11
Figure 403-3. Encounter rates of skimmers for different sweep
widths and vessel speeds versus slick thickness.
400-12
-------
404 OIL DISPERSABILITY
Dispersant Selection
The effectiveness of any particular dispersant application is dependent
on a combination of factors including oil type and condition, dispersant type
and dosage, mixing energy, and temperature. Typically, dispersants are most
effective on the least persistent (more volatile) oils and less effective on
the more persistent oils. In some cases (i.e., nonspreading oil) chemical
treatment may have little or no effect.
Dispersants contain surface active agents which reduce the oil-to-water
interfacial tension. In the presence of energy supplied by natural or
mechanical mixing - or in some cases by molecular diffusion, formation of oil
droplets is enhanced. Coatings on each oil droplet prevent their reforming.
Dispersant formulations may be divided into three basic types: those which
contain surface active agents carried in a hydrocarbon (hydrocarbon base)
solvent; those which contain surface active agents carried in an aqueous
solvent (commonly water or alcohol-water base); and those which contain high
concentrations of active ingredients in relation to the carrier (concen-
trate).
Table 404-1 lists the compatibility of major oil categories with dis-
persant types. From this table, a few general rules can be developed.
• Oils having a pour point less than the ambient water tem-
perature cannot be successfully chemically dispersed.
• High viscosity (low spreading rate oils) may be difficult to
disperse effectively.
400-13
-------
TABLE 404-1. OIL TYPE: DISPERSANT COMPATABILITY
Oil Category
Water Base
Dispersant Type
Hydrocarbon Base Concentrate
A Low viscosity, high
spreading rate oils
and products
B Moderate or high vis-
cosity waxy oils
C High viscosity low
spreading rate oils
D Non-spreading oils
X
X
Chemical dispersion not effective
^Dispersion of highly volatile products not recommended except to control
extreme fire/explosion hazard
^Effectiveness may be limited
400-14
-------
405 DETERMINATION OF APPLICATION TECHNIQUE, PRODUCT, AND DOSAGE
Application Technique
Application techniques compatible with each generic type of dispersant
are listed in Table 405-1. A number of techniques may be applicable to each
type, however, there is no established formula for selecting among the pos-
sibilities. Selection may be dictated by dispersant and equipment availabil-
ity, any limiting operating conditions, and spill magnitude. In the event of
a large spill, all available systems may be required.
Factors to consider in selecting the optimum technique should include
sea state, spill characteristics, logistics, desired treatment rate, need for
supplementary mixing energy, and cost. Table 405-2 can assist the user in
the selection process by comparing advantages and disadvantages of respective
application techniques.
Product Selection
A dispersant product must comply with federal requirements concerning
the submission of technical data to be considered for use. Figure 405-1 pre-
sents a product selection approach which uses a screening and ranking pro-
cess. Generally, products are generically identified by their manufacturer.
In cases where they are not, they may be categorized using data required by
Annex X. Candidate products can be listed in the dispersant selection work-
sheet provided in Figure 405-2. By recording appropriate data, products
having undesirable properties can be preliminarily screened. Undesirable
properties, criteria for their evaluation, and data references required by
Annex 10 are listed in Table 405-3. The acceptability of each criteria will
probably involve subjective user evaluation.
Products remaining after this screening are then ranked for relative
effectiveness and toxicity using the test data required by the worksheet.
These data are based on laboratory tests and are therefore only suggestive
of what may be encountered in the field.
Dosage
Most products are supplied with dosage recommendations, normally in
terms of dosage per acre or as a dispersant-to-oil ratio. These recommenda-
tions are based on manufacturers' experimentation'and experience and are
suitable starting dosages. Dosages beyond that required to achieve a satis-
factory dispersion should not be used. Manufacturers' representatives may be
consulted for unusual oils or conditions. Typically, experimentation with
initial applications will be required.
In field situations oil distribution is commonly irregular and quanti-
ties difficult to estimate. Under such circumstances an average or optimum
dosage must be used. Accordingly, some manufacturers supply a recommended
dosage per acre for general use. Such dosages are acceptable for initial
application, with adjustments made as appropriate after test applications.
For products where dosage is given in terms of a dispersant-to-oil
ratio, calculation of a usable application rate is necessary. Figure 405-3
400-15
-------
TABLE 405-1. APPLICATION SYSTEM: DISPERSANT TYPE COMPATIBILITY
o
o
i
Application System
Hand Spray
Neat
Vessel Spray Systems
< 20 GPM
Neat
Injection into
seawater stream
> 20 GPM
Injection into
seawater stream
Eduction into
seawater stream
Fire Systems
(portable and fixed)
Eduction into
seawater stream
Aerial Systems
Neat
Dispersant Type
Water. Base
X
X
X
X
X
X
X
Hydrocarbon Base
X
X
X
Concentrate
X
X
X
X
X
X
-------
TABLE 405-2.
ADVANTAGES AND DISADVANTAGES OF MAJOR
DISPERSANT APPLICATION SYSTEMS
SYSTEM
ADVANTAGES
DISADVANTAGES
Hand Spray
Vessel Systems
(General)
Vessel Systems
(<20 GPM)
Vessel Systems
(>20 GPM)
Vessel Systems
(Fixed fire moni-
tor or pump/hose
systems)
Vessel Systems
(Trained fire
monitor or pump/
hose systems)
Aerial Systems
(General)
Aerial Systems
(Helicopter)
Aerial Systems
(Light agricul-
tural aircraft)
Aerial Systems
(Heavy aircraft)
Equipment readily available, spray
may be accurately directed
May be used on vessels of oppor-
tunity, larger vessels provide
high dispersant capacity and
duration on station, effective
in treating windrows
Packaged systems available (WSL-
type), can be used in conjunction
with breaker boards to supply ad-
ditional mixing energy, good con-
trol of dosage
Packaged systems available, can
be used with breaker boards to sup-
ply additional mixing energy, with
dilutable dispersants effective
operating characteristics extended
Pumps, monitors, eductors commonly
built into vessels, minimal oper-
ator requirements, spray imparts
some mixing energy, can operate in
slightly higher sea states than
outrigger systems
Dispersant may be directed to oil
concentrations, may use existing
fire systems, spray may be used
for mixing
High application rates and low
response times, can operate in
higher sea states than most ves-
sels, better visual monitoring
of slick than vessels
Highly manueverable, rapid re-
sponse, many systems adapt to
most aircraft, operating base
requirements minimal
Fair availability in most areas,
adaptation of agricultural sys-
tems rapid and simple (nozzle
modification), good maneuver-
ability, minimal airfield require-
ments (dirt air strip)
High capacity and extended oper-
ating range
Limited coverage rate, dosage difficult
to control, no provision for external
mixing
Slow operational and transit speeds
limit total coverage per day, operation
in high seas may be hazardous, spotter
aircraft may be required
Flow rate too low for eduction of con-
centrate dispersants, outriggers and
breaker boards limit maximum opera-
tional sea state
Output is generally too high for heat
applications, outriggers and breaker
boards limit maximum operational sea
state
Spray distribution may be irregular
No control of dosage, operator(s)
required
Operation precluded in low visibility,
no provision for adding external energy,
high or cross winds tend to interfere
with application
Limited dispersant capacity, cargo must
be traded for fuel for long-range appli-
cations
Limited dispersant capacity, typically
must operate in sight of land, may be
difficult to achieve desired single-
pass dosage
Systems not common, maneuverability
limited during application, spotter
planes required, full-size airfield
required, may be difficult to achieve
desired single-pass dosage
400-17
-------
o
o
I
I—'
00
Generic
Dispersant
Cf
Product
A
Product
B
1
1
Product
C
1
Product
D
1
)
y
K
\
/
y
K
V
K
)
V
Undesirable
Property
Screening
K
Acceptable j
V
k k
Relative
Effectiveness
Highest ,
V
k
Lowest j
Relative
Toxicity
Lowest ,
k
Highest )
y y
K
Unacceptable .
Relative
Ranking
1
2
3
4
Do not
use
Figure 405-1. Product selection procedure.
-------
1. OPERATIONAL PARAMETERS
Product
A
B
C
D
Special Handling
Flash Point
Pour Point Acceptable?
2. CHEMICAL CONSTITUENTS
Product
A
B
C
D
3. EFFECTIVENESS -
Product
A
B
C
D
Solvents
Additives
NO. 2 NO. 6 (chose elos*
M<*»* SSSSn, Acceptable?
sst type)
Initial Relative Rank
Final Relative Rank
4. TOXICITY
Product
A
B
C
D
P. Promelas
Dispersant
Disp.+Oil
Rel. Rank
F. Heteroclitus
Ditpersant
Disp.+Oil
Rel. Rank
A. Sal ma
Oispersant
Disp.+Oil
Rel. Rank
Figure 405-2. Product selection worksheet (using data required by Annex X).
400-19
-------
TABLE 405-3. PRODUCT SCREENING CRITERIA
PROPERTY
EVALUATION CRITERIA
ANNEX X REF.
Special Handling or
Worker Safety Re-
quirements
Shelf Life
Flash Point
Excessive special handling or worker
safety precautions are undesirable
Age of product stock should be less
than stated shelf-life (check for
component fractionation, etc.)
Flash point should not be low enough
to create fire hazard or ignite if
used near fire
2003.3 - 4.4
2003.3 - 4.5
2003.3 - 4.9
Pour Point
Heavy Metals or
Chlorinated
Hydrocarbons
Pour point of product should be
below ambient water temp.
Formulations should not contain
appreciable quantities of heavy
metals and/or chlorinated hydro-
carbons
2003.3 - 4.10
2003.3 - 4.17
Availability
Short-term product availability should
be sufficient for initiation of use
None
400-20
-------
10.0 -
5.0 -
1.0 -
UJ 0.5 -
O
I
I-
O 0.1
_l
V)
0.05 -
0.01 -
11,000
1.0
(Source: SC-PCO, f978)
10
100
1,000
1,100
O O
cc.
o
<
110 O
Q.
11
10,000
Figure 405-3. Dispersant requirements at manufacturer's
recommended application ratios (gallons per acre).
400-21
-------
has been prepared to speed this calculation. To use this graph, it is neces-
sary to estimate the approximate volume of oil per area. Using the recom-
mended application ratio, the dispersant requirements in U.S. gallons per
acre can be determined.
Example: Thickness of the slick is estimated at 0.1 mm. The manufac-
turer recommends his product be used at one part dispersant to
20 parts oil. Using the graph, a dosage requirement of 5 gal-
lons per acre can be determined.
Dosage adjustment may be necessary and will require trial applications
and visual assessment. In some cases multiple applications may be required
to achieve the desired dosage. The lowest dosage which results in effective
dispersion represents the most cost-effective and environmentally acceptable
application rate.
To visually assess the effectiveness of an application, dispersion can
be thought of as a two-phase process. Initially, oil and dispersant are
mixed and individual droplets formed. Although technically dispersed, drop-
let density may be sufficient to give the appearance of an intact slick,
especially if mixing energy is low. Distinguishing dispersed oil at this
stage can be extremely difficult. The time required for the initial phase of
dispersion may vary from instantaneous to several minutes,, depending on the
product and mixing energy. Nature conducts the second phase of dispersion by
physically separating the treated droplets both vertically and horizontally.
Oil is being rapidly dispersed when a coffee-colored cloud forms in the water
column after treatment. In an effective final dispersion,, little or no
floating or reforming oil should be detected.
400-22
-------
406 DISPERSED OIL MOVEMENT AND CHARACTERISTICS
Dispersed oil forms a plume in the upper water column which may or may
not travel in the same direction and speed as would untreated floating oil.
Since ecologic effects associated with dispersed oil and dispersant are
directly related to their nature and concentration, prediction of plume move-
ment, composition, and concentration at any point of interest is desirable.
This section provides guidelines for field estimation of mixing depths in the
water column, initial concentration of oil and dispersants, direction of
plume movement, concentration of oil and dispersants at various points of
interest, and general types of degradation which can be expected.
Evaluation of dispersed oil movement and characteristics includes:
• estimation of initial mixing depth
• estimation of initial concentrations of oil and dispersant
over a specified mixing depth
• prediction of movement of the dispersed material
• estimation of maximum plume center line concentrations at
any point of interest
• evaluation of probable changes in composition with time
Figure 406-1 is a worksheet for the computation of dispersed oil move-
ments and dilution.
Estimation of Initial Mixing Depth
Dispersants and dispersed oil will mix relatively rapidly with near sur-
face waters by turbulent diffusion and other processes. Mixing depth is con-
trolled largely by the amount of available energy supplied by wind waves,
swells, tidal currents, wind-induced currents, density currents, and artifi-
cially supplied energy (breaker boards, fire streams, propellers, etc.).
Determination of "initial" mixing depth is necessary for predictive modeling
of the dispersion plume and may be conducted by several methods.
Direct Observation. Mixing depths may be monitored visually in the field
using divers (visibility permitting) or more precisely with field chemical
measurements.
Calculation. If direct observations are not possible, initial mixing
depths may be approximated from observable features such as wave height.
Although no simple formulas exist for vertical diffusion and mixing processes
in the ocean, the guidelines presented in Table 406-1 may be used. When
using these guidelines, the greatest applicable mixing depth should be selec-
ted. Field observations suggest oil dispersed in the open ocean will remain
near its initial mixing depth unless the mixing phenomenon changes.
400-23
-------
INITIAL MIXING DEPTH
Wind Waves
Swell
Artificial
Max
INITIAL CONCENTRATION (Co)
Oil
Dispersant
SURFACE WATER MASS MOVEMENT
Direction
Speed
THREATENED AREAS
1 (Specify) Dist ETA Cmax.
2
*
3
Figure 406-1. Dispersed oil movement worksheet.
400-24
-------
TABLE 406-1. ESTIMATED INITIAL MIXING DEPTHS
Situation
Mixing Mechanism
Depth Guideline
Open Ocean Windwaves
Swell
Near Shore Mixing depth highly vari-
able, may mix to bottom
Artificial Breaker Boards*
Mixing Modified Breaker Boards*
Vessel Wake and Propeller*
Fire Stream*
50% of observed wave height
10% to 25% of observed
swell height
1/2 meter
2-3 meters
Propeller Depth
1/2 Meter
*Smith, G.F. and McCracken, W.E., 1977, "Techniques for Mixing Disper-
sant-Treated Oil Slicks into the Water," Proceedings, 1977 Oil Spill
Conference.
400-25
-------
Estimation of Initial Concentrations of Oil and Dispersants
The initial concentration of oil and dispersant introduced into the
water column can be calculated on the basis of oil thickness and dispersant
applied, effectiveness of the dispersion (percent oil remaining dispersed),
and the initial mixing depth. Figures 406-2, 406-3, 406-4, and 406-5 may be
used to calculate concentration of dispersed oil (in parts per million) for
various depths and degrees of dispersion effectiveness. To use these
figures, the volume of oil present must be estimated. It may be entered in
the figures as average slick thickness or as estimated oil per unit area. To
reach an acceptable representation of total oil entering the water column
under such circumstances, oil volume estimates should be based on averages
over large areas (acres).
Dispersion effectiveness testing is among the data required by Annex X.
Test data is given in terms of percent initial dispersion (after 10 minutes)
and percent final dispersion (after 120 minutes) for no. 2 and no. 6 fuel
oils. If used carefully, this data may be used to estimate effectiveness
sufficiently to permit planning-type calculations. Effectiveness should be
approximated from Annex X data (rounded to the nearest 25 percentile) for the
most similar oil type. Final effectiveness values given in Annex X data are
probably most representative. For any particular dispersant, final effec-
tiveness values that are greater than the initial values suggest the contin-
uing effect of the dispersant. Final values that are less than initial
values can be associated with the resurfacing of larger oil droplets with
time. Based on the mixing depth previously determined, the calculated
dispersion concentration may be read directly off the figures. (Values pro-
vided by the figures do not reflect overall or component losses resulting
from dissolution or other processes during weathering).
Example: Estimate the concentration of No. 6 fuel oil dispersed by pro-
duct A in seas with 2 meter wave height. No supplementary
mixing is used. From Table 406-1 the estimated initial mixing
depth is half the wave height, or 1 meter. Test data required
by Annex X for product A suggests a final effectiveness with
No. 6 fuel oil of 40 percent for a dispersant/oil ratio of
1:10. Average thickness of the slick is estimated at 0.1 mm.
Using Figure 406-3 (50 percent effectiveness) concentration of
dispersed oil in the upper meter of water can be estimated at
50 ppm.
Estimation of dispersant concentration in near surface waters is less
complicated than for oil, as dispersant application is more or less uniform.
Based on an application in gallons per acre, Figure 406-6 can be used to
estimate dispersant concentration at depth. For example, the dispersant con-
centration in the upper meter of water at an application rate of 10 gallons
per acre is approximately 10 ppm.
Figures 406-7, 406-8, 406-9, and 406-10 can be used to estimate water
column concentrations when dosage is given as a dispersant-to-oil ratio. For
example, it is desired to estimate the dispersant concentration in the upper
3 meters for a slick averaging 0.1 mm at an application ratio of 1:20. Using
Figure 406-8 the concentration can be read as approximately 1.2 ppm.
400-26
-------
o
o
I
0.01
1.0
10.0
100.0
1,000.0
10,000.0
Figure 406-2. Concentration of dispersed oil at various depths
at 25 percent dispersion effectiveness (ppm).
-------
a
i
CD
0.01
10.0
1000
1,000.0
0
10,000.0
Figure 406-3. Concentration of dispersed oil at various depths
at 50 percent dispersion effectiveness (ppm).
-------
.p-
O
O
I
0.01
0.1
1.0
10.0
1000
1.000.0
Figure 406-4. Concentration of dispersed oil at various depths
at 75 percent dispersion effectiveness (ppm).
-------
o
o
I
y
o
o
_l
in
0.01
10.0
100.0
1,000.0
10.000.0
Figure 406-5. Concentration of dispersed oil at various depths
at 100 percent dispersion effectiveness (ppm).
-------
o
o
I
0.01
0.1
1.0
10.0
100.0
1,000.0
Figure 406-6. Dispersant concentration (ppm) homogeneous
mixing at indicated depth.
-------
o
o
I
LU
Lt
O
<
IT
ill
Q.
o
CO
z
o
_l
<
0 1
1 0
10.0
100.0
Figure 406-7. Concentrations of dispersants in upper meter
for various D/O application ratios (ppm).
-------
O
O
I
LU
z
*
O
X
O
_l
c/I
LU
oc
CJ
cc
LU
a.
_l
5
u_
o
z
o
_1
<
0.001
0.01
1000
1
1,000.0
Figure 406-8. Concentrations of dispersants in upper 3 meters
for various D/0 application ratios (ppm).
-------
.p-
o
o
I
E
£
v:
o
i
cc
o
<
QC
LU
Q.
o
LL
O
2
O
_J
_l
<
0.1
i.o
10.0
100.0
1
1,000.0
Figure 406-9. Concentrations of dispersants in upper 10 meters
for various D/0 application ratios {ppm).
-------
-e-
o
o
I
U)
HI
DC
O
<
DC
LU
CL
O
CO
z
o
o
0.001
0.01
1.0
10.0
100.0
1
1,000.0
Figure 406-10. Concentrations of dispersants in upper 30 meters
for various D/O application ratios (ppm).
-------
Prediction of Movement of the Dispersed Oil and Dispersant
In most cases the movements of floating oil are dominated or strongly
influenced by wind. Once dispersed into the water column, however, the
effect of wind diminishes and other processes including oceanic and nearshore
circulation may be more important. The direction and rate of the near sur-
face water movement must be estimated for each situation. Sufficient hydro-
graphic information may be available to permit estimation of movement and
direction by graphic methods. If sufficient information is not available,
direct field measurements of water movement such as with dye-drops and sub-
sequent tracking or by tracking of subsurface drogues may be required.
Estimation of Plume Centerline Concentrations
Based on diffusion theory (Fickian) for surface plumes in oceanic envi-
ronments, it is possible to estimate the theoretical maximum concentration of
unaltered oil and dispersant at any desired downcurrent distance. Resulting
concentrations will be extremely conservative in that evaporation, dissolu-
tion, and other subtractive processes cannot be directly considered due to
lack of representative decay or rate constants. The basic formula* for cal-
culation of maximum plume centerline concentration is:
3/2
(1+2/3
C = C erf
max o
x
where: 0 - =
with C = maximum concentration in plume at distance (x)
max ^
downcurrent
C = initial concentration at initial mixing depth
x = distance downcurrent (cm)
b = initial plume width (width of treatment zone
perpendicular to direction of movement) (cm)
U = average current velocity (cm/sec)
a = 0.01 cgs units (factor relating horizontal eddy
diffusivity to lateral plume spread)
erf = standard error function which is defined as
*Note: The model presented is based on standard ocean outfall design prac-
tice. The objectives of the original model and properties of the
materials it deals with are felt to be reasonably similar to the oil
dispersion issue.
400-36
-------
-t2dt
erf x
The equation may be solved in terms of the ratio C : C by calcula-
/, t max °
ting p x/b where:
x 0.12 x
Ub
2/3
The equation may be solved in terms of the ratio C : C by calcula-
ting the factor x/b and using the graph provided in Figure 40o-ll. Para-
meters used in the calculation of x/b can all be readily estimated in the
field.
It is important to note that concentrations projected using this formula
can be taken as maximum values. Not included in the calculation are decay
factors such as evaporation, photo oxidation, biodegradation, and so on.
Changes in composition due to these factors are discussed in the following
section. Additionally, when applying the formula it should be kept in mind
that the resulting dispersion may not be uniform. In cases where dispersion
is not totally effective, the amount of oil actually dispersed in the water
column can be reestimated and concentrations recalculated. In such
instances, consideration must be given to assessment of the fate of the
resurfaced oil. Incomplete oil dispersion should not seriously affect
the calculation of dispersant concentrations in the water column.
Example: Estimate the water column concentrations of oil and disper-
sants where the dispersion plume is expected to encounter a
shellfish bed. At the time dispersion can be implemented, the
floating slick has spread to a width of approximately 1000
feet (b = 3.05 x 10 cm). Water velocity (^) has been measured
at 0.3 knot (15 cm/sec). The shellfish bed is 20,000 ft
(6.1 x 10 cm) from the dispersion line.
Using data from a previous example, initial concentrations
(C ) in the surface meter were estimated at 50 ppm dispersed
oil and 10 ppm dispersant.
Therefore:
x
& -
b
0.12 x
0.12 (6.1 x 10 )
15(3xl04) 2/3
- 5.04
Using Figure 406-11 the
max
ratio can be determined as
400-37
-------
8C-001?
MAXIMUM CONCENTRATION,
to
8
8 S
o, §|
fi
Q 3
o
CD
II
3 3
131 o
cr|x o
11 8
DO
;o
w
TO
o-ix
o
ca
O
o>
X
DILUTION FACTOR,
C0
-------
0.15. Applying this ratio, maximum concentrations at the
shellfish bed can be calculated as 7.5 ppm oil and 1.5 ppm
dispersant.
Travel time for the plume can be calculated at about 11 hours.
During this time a substantial loss of light molecular weight
hydrocarbons can be expected, decreasing both the total con-
centration, and reducing toxic properties.
Evaluation of Changes in Composition with Time
Toxic effects are generally associated with lower weight carbon mole-
cules (C..-C.., and lower), most of which will dissolve or evaporate in the
early hours or the spill. Evaporation will usually account for the greatest
percentage of loss. Table 406-2 presents typical evaporative/dissolution
losses with time and wind exposure. The data indicates most of the lighter,
more toxic fractions of oil are lost within 24 hours. Field evidence sug-
gests that dispersion can increase the naturally occurring loss rate due to
evaporation and dissolution.
400-39
-------
TABLE 406-2. TYPICAL EVAPORATION-DISSOLUTION LOSS
o
o
i
Fraction
Paraffin (C&-CU)
Paraffin (ci5~C22^
Cyclo-Paraf f in
(c5-cn)
Aromatic
(Mono-cyclic)
(c6-c10)
Aromatic
(Poly-cyclic)
Residual
PERCENT OF FRACTION REMAINING2
Wind 5 kt 10 kt 20 kt
Evap:Dissol. ' Exposure 12 24 48 hrs 12 24 48 hrs 12 24 48 hrs
60:1 30 10 1 511 111
97 95 89 97 95 89 97 95 89
12:1 25 7 1 511 111
6:1 20 4 1 511 111
20:1 99 98 96 99 98 96 99 98 96
100 100 100 100 100 100 100 100 100
Calculated for 10 kt wind
These values are approximate and dependent on factors including temperature,
oil film thickness, emulsification, etc.
Estimated time for 10 percent remaining is 40 days
Estimated time for 10 percent remaining is 110 days
orM rn/"t? . T „ v ~i <• I O"7 1 \
-------
407 IMPACT COMPARISON
General Procedure
Oil spill response decisions should aim for the minimum probable envi-
ronmental damage whether chemical dispersion is used or not. This section
provides a means for identifying amenities threatened by various actions and
assessing their probable impacts. It also provides onscene criteria for
weighting resulting impacts. Evaluations may be conducted for the entire
spill or for specific geographic areas of a large incident. Impacts can be
evaluated and compared using the following steps:
A. Using information provided in Sections 302, 402, and 406,
list the amenities threatened by both conventionally or
nontreated oil, and by chemically treated oil.
B. Assess the probable severity of each type of impact for
both conventionally or non-treated and chemically treated
cases for each amenity as appropriate.
C. Weigh the impacts and identify the case resulting in the
least probable impact for the situation.
Note: When conducting the assessment and comparison, it is
important to remember that chemical treatment will
likely not be 100 percent effective. Oil not dispersed
in the upper water column at the point of contact with
the threatened amenity may react as untreated oil and
require assessment in both categories.
Impact Comparison Matrix
Figure 407-1 provides a matrix to be used in organizing the impact
assessment and comparison. Before using the matrix, predicted movement and
extent of untreated and dispersed oil (as determined in Section 302 and 406)
should be plotted an appropriate charts. In consultation with local repre-
sentatives, amenities of concern within both zones of exposure should be
identified (Section 402) and listed in the threatened amenity column of the
matrix. The general types of impacts can then be assessed. Three levels of
impact should be considered: probable severe impact; unknown impact; and
probable low impact. More specific guidelines for defining a "probably
severe" impact to an amenity are given in Table 407-1.
Where the extent of possible contamination is uncertain, evaluations
should assume a worst-case situation. Subjective judgements about non-biolo-
gical impacts are relatively straightforward and self-explanatory. Biologi-
cal questions are more complex. The following discussion will help the user
assess "biological" questions related to treated and untreated cases.
The Chemically Treated Case
Extensive information exists regarding the toxic effects of oil and dis-
persants but this information must be used with caution in regard to direct
field application. Laboratory tests and field observations regarding the
effects and performance of the high toxicity Torrey-Canyon era dispersants
400-41
-------
CONVENTIONALLY OR
NOT TREATED
CHEMICALLY
TREATED
THREATENED
AMENITY
+ = Probable severe impact
0= Unknown impact
-= No or probable low impact
Figure 407-1. Impact comparison matrix.
400-42
-------
TABLE 407-1. CRITERIA FOR "SEVERE" IMPACT RATING
IMPACT CATEGORY
SEVERE RATING CRITERIA
ECONOMIC
If the temporary or long-term loss of
an amenity will affect the local or
regional economy directly (e.g., clos-
ing of commercial fishing grounds) or
indirectly (e.g., decreased tourism
because of contaminated recreational
beaches), then the the particular
action is considered to have a "prob-
able severe Impact" on the amenity.
AESTHETIC
TOXICITY
SMOTHERING
SUBLETHAL
PERSISTENCE
RECOVERY
If the temporary or
sence of oil will ch
value of an amenity.
If the amenity is va
because of its appea
on sailboat hulls, o
tlonal beach), then
action is considered
able severe impact
longer-term pre-
ange the esthetic
and especially
lued in part
ranee (e.g. , oil
11 on a recrea-
the particular
to have a "prob-
on that amenity.
If the presence of oil, dlspersant, or
dispersion, through the action of its
chemical properties, will adversely
affect a major portion of a biological
amenity (e.g., a commercial shellfish
bed) then the particular action is
considered to have a "probable severe
impact" on that amenity.
If the oil will adversely affect a
major portion of a biological ameni-
ty through the action of physical
contact (I.e., smootherlng, covering,
clogging, suffocating) then the parti-
cular action is considered to have a
"probable severe Impact" on that
amenity.
Oil, dlspersant, or components there-
of will interfere with a significant
portion of a population or community
at a sublethal level. Interferences
can include disruption of reproduc-
tive or other functions, carcinogen
effects, and so on.
If contamination by oil, dlsper-
sant, or dispersion will result
in the incorporation of oil and/
or toxic substances in the envi-
ronment (e.g., burial on a beach)
such that they become a long-term
fixture of that environment, then
the particular action is considered
to have a "probable severe Impact"
on that amenity.
If the temporary or longer-term pre-
sence of oil, dlspersants, or disper-
sions will physically or chemically
delay or prevent the recovery of the
amenity to pre-splll conditions, then
the particular action is considered
to have a "probable severe impact"
on that amenity.
400-43
-------
are not germane to, nor should be used in the assessment of modern, low toxi-
city products. Data on modern dispersants are difficult to compare due to
the considerable variability in test oils, procedures, test organisms, and
duration of exposure, and can seldom be compared or applied directly to the
field. Test data required by Annex X does provide a measure of uniformity
and, while not directly applicable to field use, may be used to rank pro-
ducts. Toxicity rankings should be used in terms of order(s) of magnitude
differences and not absolute values. In the broadest sense, the joint IMCO/
FAO/UNESCO/WMO Committee (1969) proposed grades of toxicity for pollutants
in the aquatic environment can be used to indicate how order of magnitude
differences relate in scale (Table 407-2). Grades proposed by other experts
are also shown in this table.
After identifying lower toxicity dispersants using the EPA toxicity
data, estimates of dispersant and oil concentrations in the water column, as
described in Section 406, can be used for predicting potential ecological
effects. Although no field-worthy models exist for predicting the ecological
effects associated with a given concentration of oil or dispersant, approx-
imate toxic concentration limits for each dispersant product and each generic
oil type can be delineated by relating estimated dispersant concentrations
with EPA LC data for approved dispersants (an LC-- is the concentration at
which 50 percent of the test organisms do not survive over a given time
period). Figure 407-2 (impact severity chart) can then be used to estimate
the impact severity a particular dispersant could have on a particular biolo-
gical amenity. The figure should be used in the following manner:
1) Obtain the most sensitive LC,._ from the EPA data for the
proposed dispersant(s) (i.e., use the lowest ppm LC of
the three bioassays).
2) Find the LC value on the vertical axis of the figure and
draw a horizontal line from that point.
3) Obtain the estimated concentration of the dispersant or
oil/dispersant at the desired location from Section 406.
4) Find the dispersant concentration on the horizontal axis
(for the appropriate safety factor) and draw a vertical
line from that point.
5) If the two lines intersect above the diagonal line, the
dispersant can be expected to have "probable low impact" on
the biological amenity. If the two lines intersect below
the diagonal line, the dispersant can be expected to have a
"probable severe impact" on that amenity.
Three safety factors are incorporated in the horizontal axis of the
chart. In 1972, the NAS-NAE Committee on Water Quality proposed that "the
prediction of safe levels be made by carrying out bioassays for acute lethal
toxicity and multiplying the lethal concentration by a, suitable application
factor." The committee recommended that the maximum concentration not exceed
400-44
-------
TABLE 407-2. GRADES OF TOXICITY
Practically
non-toxic
Slightly
toxic
Moderately
toxic
Toxic
Very Toxic
TLmdng/l)1
MO.OOO
1,000-10,000
100-1,000
1-100
1
2
LC50(ppm)
10,000-1,000,000
1,000-10,000
100-1,000
10-100
10
LC50(ppm)
>10,000
1000-10,000
100-1000
100
1
IMCO/FAO/UNESCO/WMO Group of Experts (1970).
-Jeffery, P.G., and J.A. Nichols (1974).
Beynon and Cowell (1974)
400-45
-------
NO OR PROBABLE LOW IMPACT
PROBABLE SEVERE IMPACT
(0.10 safety factor)
(0.01 safety factor)
(0.001 safety factor)
CONCENTRATION IN WATER COLUMN (ppm)
Figure 407-2. Impact severity chart.
400-46
-------
one one-hundredth (0.01) of the LC values. This 0.01 factor is intended
for application to single species, and is subject to some question when
applied to ecosystems whose component members may exhibit varying levels of
toxic response. The accuracy of the resulting impact prediction improves if
the procedure is used on a number of local species. When only EPA test data
are available the resulting predictions should provide a general indication
of overall impact. For highly sensitive situations demanding additional pre-
caution, a 0.001 safety factor (one one-thousandth of the LC,-_) can be
applied; for less sensitive situations, concentrations using a 0.1 safety
factor (one tenth of the LC_Q) can be used. Selection of the appropriate
factor is at the discretion of the OSC in consultation with his support staff
and local scientists.
Exposure time is another important consideration. Typically, the longer
an organism or aquatic community is exposed to a given concentration, the
higher the potential for adverse impacts. In using Figure 407-2, it is
assumed that organisms will be exposed indefinitely. In reality, concentra-
tions actually encountered likely to be short-term phenomena owing to natural
mixing and rapid dilution phenomena. EPA LC bioassays are run for 48 or 96
hours, depending upon the test organisms and concentration is not diluted
over time. The use of the most sensitive (lowest ppm) of the three bioassay
tests for the dispersant's base LCc0 skews the outcome toward the "probably
severe impact" designation.
Example: A valuable shellfish bed lies 3 m deep and 2 km from the pro-
posed dispersion point. The estimated concentration of dis-
persant at the bed is calculated at 2 ppm, and EPA toxicity
data shows the lowest LC__ concentration for this dispersant
to be 2500 ppm. Using Figure 407-2 the point where 2500 ppm
and 2 ppm intersect (using the 0.01 safety factor) is clearly
in the "probable low impact" area. Thus, the specified dose
of this dispersant should not acutely affect the shellfish
bed. If the most sensitive LC_0 for the dispersant had been
100 ppm instead of 2500 ppm, tne conservative prediction would
have been different (i.e., the dispersant should have a prob-
able severe impact).
Multiple Dispersant Applications and Maximum Permissible Dosage. Figure
407-2, can also be used to estimate safe maximum concentrations for multiple
dispersant applications or the permissible maximum concentration for a given
LC_0 toxicity. The maximum allowable (sublethal) concentration of dispersant
in the water column is divided by the anticipated concentration from each
application to determine the number of applications that can be safely under-
taken. This number will be quite conservative in areas with high circulation
rates as continual dilution will preclude the buildup of high dispersant con-
centrations. Under no circumstances should the indicated maximum acceptable
concentration be exceeded.
Dispersed Oil Effects
After determining the potential effects of the dispersant, the potential
effects of the dispersed oil must be evaluated. Unlike dispersants, no stan-
dardized toxicity test for oil exists, as the composition of oils and refined
400-47
-------
products vary widely. Should the user have access to toxicity data for an
oil similar to the one spilled, Figure 407-2 can be used to predict the
severity of the potential impact in a fashion similar to one for dispersants.
Again, use of the 0.01 safety factor and the assumption that all the toxic
components of the oil are transferred into the water column (when, in fact,
the more volatile fractions are usually quickly lost through evaporation)
should ensure an adequately conservative outcome. If no oil toxicity data
are available, background information on the effects associated with generic
oil types and past spill events (as discussed for the untreated case) will
have to be used in making assessments.
Some laboratory and field evidence suggests that chemically produced oil
dispersions may be more toxic than naturally produced dispersions. It has
been hypothesized that this phenomena is a synergism between oil and disper-
sant which produces more toxic end products. The "increased toxicity" of a
dispersion is probably more related to the increased availability of the oil
to marine organisms. By breaking the oil up into minute droplets, the dis-
persant enhances the uptake and incorporation of certain oil components by
many marine organisms through their breathing and feeding mechanisms. For
this reason, dispersed oil may have a more adverse impact on a biological
amenity than untreated oil at the same concentration.
This differential could be extremely important in relation to the incor-
poration of certain polycyclic aromatic hydrocarbons and complex hydrocarbons
and tars into edible fish and shellfish as they may result in tainting. In
addition, these substances have been implicated as possible carcinogens
though the dose/response relationships for both large, single-dose exposures
and low-level, chronic exposures to such carcinogens are far from resolved.
The breakdown of oil into fine droplets has some environmental advan-
tages which may outweigh its possible drawbacks. By increasing the surface
area exposed per unit volume of oil, biodegradation is accelerated thus
decreasing persistence in the marine environment. Similarly, the dispersant,
by coating the oil droplets may prevent the oil from sticking to plant, rock,
and sediment substrates.
Little information is available regarding sublethal long-term effects
of dispersed oil. Chronic low-level exposure could occur if oil or disper-
sant is incorporated into sediments and gradually released with time. This
is most likely to occur in estuaries and near-shore environments. Sublethal
concentrations and effects are difficult to detect and measure in the envi-
ronment. Such sublethal effects include possible change in fecundity, fer-
tilization, larval development, respiratory rate, and escape and feeding
responses. Recognizing the possible consequences in a population or marine
community, some researchers have proposed that standard toxicity tests should
measure the lowest median concentrations that affect biological functions
important for survival of individuals in an ecosystem. Many modern disper-
sants are, however, biodegradable and should not create chronic toxicity
problems. Until better information is available prediction of biological
effects expected with dispersants, dispersions, and untreated oil must be
dictated by lethal concentration considerations and prudent use of safety
factors.
400-48
-------
The Untreated Case
The deleterious effects of untreated oil on marine life are largely due
to physical rather than chemical action [i.e., interference of respiration
through clogging (smothering) of gill filaments versus physiological effects
of uptake of toxic components]. Although certain components of oil are
extremely toxic, the smothering and mechanical interference of biological
activity often cause greater damage.
Low-boiling aromatics and saturated hydrocarbons (e.g., in light fuel
oils) appear to be more directly toxic than the higher-boiling saturated
hydrocarbons (e.g., in heavy crudes). Typically, those fractions with low
boiling points are lost first. Table 407-3 gives the estimated concentra-
tions (ppm) of the soluble aromatics required to cause toxicity in various
classes of organisms and the amount of No. 2 fuel oil and a representative
crude oil needed to produce an equivalent dose of aromatics. It is apparent
from the table that No. 2 fuel oil owes its high toxicity to its high aro-
matic content. Larval forms are more susceptible to impact than are the
adults of the same species. In the case of an offshore spill moving onshore,
chemically toxic, unweathered oil may never come into contact with marine
organisms other than plankton populations in the immediate spill vicinity.
Tainting and the accumulation of potentially carcinogenic agents in com-
mercial fish and shellfish can and do occur with an untreated oil slick
through natural dispersion, solubilization, and long-term persistence. The
higher molecular weight polynuclear fractions in oil may be particularly sig-
nificant in their persistence and subsequent accumulation in the food web,
although many of the edible fish and shellfish species depurate (or elimina-
te) the petroleum hydrocarbons that they accumulate when no longer exposed to
contamination.
When a weathered oil does reach the nearshore area, massive mortalities
can result. The most visible class of organisms affected are usually birds,
particularly those species that feed by diving. Oil penetrates and clings to
the plumage, matting the feather structure and causing loss of insulative
properties. The bird can then become chilled and susceptible to severe meta-
bolic stress, exhaustion, and disease. In addition, an oiled bird can ingest
quantities of oil during preening which can cause poisoning, inflammation of
the digestive tract, or disturbance of other physiological processes. Oil
can also have a profound direct effect on the viability of bird eggs and on
the capability for incubation of fertile eggs if the breasts of nesting birds
are contaminated.
Invertebrate populations may suffer dramatically when in physical con-
tact with the oil. Recruitment and recovery can be rapid if the affected
organisms represent only a portion of a larger, regional population and the
oil does not persist. Successional recovery of an intertidal marine commu-
nity ranges from weeks or months to a decade, depending on the structural
complexity of the community, the amount and type of oil present, the persis-
tence of the oil, and the degree of the initial damage. Persistent
contamination by petroleum, or frequent chronic spills, may hinder natural
succession and slow recovery.
400-49
-------
TABLE 407-3 SUMMARY OF TOXICITY DATA
CLASS OF ORGANISMS
FLORA
FINFISH
LARVAE
(All species)
PELAGIC
CRUSTACEANS
GASTROPODS
(Snails, etc.)
BIVALVES
(Oysters, clams,
etc. )
BENTHIC CRUSTACEANS
(Lobsters, crabs, etc.)
OTHER BENTHIC
INVERTEBRATES
(Worms, etc.)
Es timated
Concentration
(ppm) of
Soluble
Aroma tics
Causing
Toxicity
10 - 100
5-50
0.1 - 1.0
1 - 10
10 - 100
5-50
1 - 10
1 - 10
Estimated Amount (ppm)
of Petroleum Substances
Containing Equivalent
Amount of Aromatics
#2
FUEL OIL FRESH CRUDE
50 - 500 104 - 105
25 - 250 104 - 105
0.5 - 5 102 - 103
5-50 103 - 104
50 - 500 104 - 105
25 - 250 104 - 105
5-50 103 - 104
5-50 103 - 104
Stephen Moore. 1973. Background Papers for a Workshop on Inputs, Fates,
and Effects of Petroleum in the Marine Environment. National Academy of
Sciences.
400-50
-------
Comparing Impacts
The completed comparison matrix forms a basis for determining the most
acceptable overall mode of treatment. The individual impact cells of the
matrix are not additive and therefore the most appropriate action will not
necessarily be the one with the least number of severe impacts. The matrix
has been designed as a qualitative rather than a quantitative tool because
different amenities can have dramatically different values at different times
of the year and in different local and regional settings. For example, a
waterfowl feeding area along a coast may be considered more valuable during a
winter spill when large numbers of birds are present than would a recreation-
al swimming area that is used almost exclusively in summer. Their relative
standing might be reversed during a summer spill depending on the type and
expected persistence of the oil, relative recovery times for both the water-
fowl feeding and swimming areas, and the availability of similar areas out-
side the zone of contamination. Conceivably a local or regional community
that depends solely on tourism for its livelihood would consider a single
severe impact to their recreational beaches more important than a combination
of other types of impacts.
The purpose of the matrix is to ensure that the major potential effects
of each action are considered. In consultation with local and regional
experts, the user must compare the different weightings of the amenities in
determining the most acceptable alternative.
Example: A crude oil spill occurs in coastal waters and threatens to
move into an area characterized by the special features and
amenities as identified by the OSC and listed in Figure 407-3.
Environmental conditions preclude conventional control actions
in all areas with the exception of the larger estuary. Even
in this area the adequacy of any conventional effort is uncer-
tain. Considering the sensitive nature of the shoreline, it
is decided to evaluate the feasibility of chemical dispersion
offshore to reduce the overall damage. Estimated zones of
contamination are calculated using procedures presented earli-
er in this manual. The results are shown in Figure 407-3.
With the assistance of local and regional experts, evaluations
of the impact severity on each amenity are conducted. The
results are listed on the comparison matrix shown in Figure
407-4. As indicated, "probable severe impacts" can be expec-
ted with oiling of all threatened shoreline amenities. Chem-
ical dispersion is an attractive alternative because it may
reduce or eliminate contamination of these areas. Plume dis-
persion modeling suggests that an important commercial shell-
fishing area lies in the path of the dispersed oil plume, and
that the concentration of dispersant in the waters over the
shellfish bed may reach 1.5 ppm. Toxicity data on the dis-
persant used include a lowest LC of 1000 ppm. Using Figure
407-2 a "probable low impact rating" is determined using a
0.01 application factor. The concentration of dispersed oil
at the shellfish area has been previously estimated at 100
ppm. Travel time has been previously estimated at 20 hours,
400-51
-------
': "ipf • Waterfowl rookery
• Industrial water intake .2ijS**&'~'}
I . ,.J%®>
Figure 407-3. Hypothetical spill event.
400-52
-------
CONVENTIONALLY OR
NOT TREATED
CHEMICALLY
TREATED
THREATENED
AMENITY
Waterfowl
rookery
Industrial water
intake
Endangered
species
Recreational
beach
Commercial
shellfishing area
-
+
-
+
+
-
-
+
0
-
+
-
+
-
0
-
0
-
0
-
-
-
0
-
0
-
+
-
0
-
-
-
-
-
-
-
-
0
-
-
-
0
+ = Probable severe impact
0= Unknown impact
- = No or probable low impact
Figure 407-4. Hypothetical spill event impact comparison matrix.
400-53
-------
sufficient to allow significant reduction in this concentra-
tion through loss of volatile fractions. In addition, the
calculations consider only the upper several meters; the
shellfish beds are at a depth of 60 meters. Thus, risks to
the amenity appear far less than the probable effects of
untreated oil impact on the amenity shoreline. Chemical
treatment is recomended at the indicated site.
400-54
-------
SECTION 500
CRITERIA FOR USE OF DISPERSANTS ON SHORELINES
501 GENERAL PROCEDURE
Dispersants can aid in the restoration of shorelines by loosening or
dissolving oil coatings or preventing the adherence of physically loosened
oil particles on other surfaces. Due to difficulties in controlling dosage
and the potential for environmental side effects, dispersants should only be
considered for cleaning contaminated shorelines when mechanical cleanup and
natural recovery are judged very difficult, ineffective, or potentially more
environmentally damaging. To consider products for shoreline use, they
should be recommended for that purpose or designated as beach-cleaners by
their manufacturers.
Figure 501-1 gives a sequence of considerations required to evaluate the
probable acceptability of dispersant use for shoreline cleaning. Supporting
sections of the manual have been referenced when appropriate.
500-1
-------
O
O
I
ro
K
Determine
area of
effect
(402)
Contamment imminent y
K
Oil onshore
V
•Manual of Practice for Protection
Vnlnmec 1 anri 7 (EPA-600/7-79-
V
K
Effective y
adequacy ^f
of surface '
collecting
agents k
Ineffective ^
V
K
Adequate y
Evaluate
conventional
clean-up
techniques
(502)
K
Inadequate y
V
and Cleanup of Shorelines-
187aand 187b)
V
K
Acceptable .
V
Evaluate
natural k
potential \
(503) Acceptable J
\^elect ' "I/
(504) r
"•••»-=K»U,O y Evaluate
^^_^_^ / Impacts k
I/ (firm) JV
Unacceptable y
V
Implement
(Appendix D)
Go to oil
onshore
Implement
manual*
Allow to clean
naturally
Consider use of
dispersants
(Appendix C!
Consider
extraordinary
actions
Figure 501-1. Sequence for consideration of dispersant use on shorelines.
-------
502 CONVENTIONAL PROTECTION AND CLEANUP POTENTIAL
Mechanical Cleanup of Shorelines
Physical removal is generally the preferred method for cleaning oil con-
taminated shorelines. The EPA Manual of Practice for Protection and Cleanup
of Shorelines (EPA-600/7-79-187a and 187b) describes cleanup techniques and
sets guidelines for the selection of the proper technique for various spill
and shoreline conditions.
Dispersant use on shorelines may be acceptable if one or more of the
following conditions exist:
1. Insufficient physical cleanup equipment and/or manpower to effec-
tively clean the shoreline in a timely manner.
2. No land or water access for mechanical cleanup equipment.
3. Contaminated beach sediment cannot be removed and replaced without
causing unacceptable environmental damage.
Insufficient Resources. This condition may occur in the event of a large
oil spill where many kilometers of shoreline are contaminated and there is
insufficient cleanup equipment available locally or regionally. The same
condition may also arise for a smaller spill in a remote area where required
equipment is not available.
Lack of Access. Certain shoreline areas may be inaccessable to cleanup
equipment from land because there are no roads in the region, or there are
marshlands or cliffs behind the beaches. Access from the water may not be
possible because of heavy surf conditions or shoals.
Sediment Removal. Removal of contaminated sediment from a shoreline may
cause unacceptable environmental damage. This may occur if (1) sediment
removal upsets a delicate habitat, (2) natural replacement of the removed
sediment by littoral processes would not be sufficient, (3) sediment removal
would cause excessive erosion of backshore areas, or (4) a local supply of
similar sediment was not available to replace the sediment during the cleanup
operation.
500-3
-------
503 NATURAL CLEANING POTENTIAL
The acceptability of allowing an oiled shoreline to clean naturally is
based on the rate and degree of natural cleaning and their compatibility with
desired recovery and resumption of use of the area.
Several factors influence the natural cleaning potential of a shoreline
area. These factors in the order of their importance are:
1. The energy level of the shoreline area.
2. The type and volume of the spilled oil and its depth of penetration.
3. The prevailing climate.
Energy Levels
The energy level of a shoreline can be defined as the mechanical energy
imparted to the shoreline by waves and wind and is generally indicated by the
size and frequency of waves which impact the shoreline. Shorelines which
have predominately onshore winds will have higher energy levels than shore-
lines where the wind blows predominately offshore. Fetch is an indication of
the degree of exposure or shelter for a given shoreline and is defined as the
length of water surface area over which winds can generate waves. Other
indications of shoreline energy levels for sediment beaches are the height of
a beach berm or ridge and sediment sorting on a given shoreline. The height
of the berm (on sand beaches) or ridge (on pebble/cobble beaches) is a direct
function of wave height; increases in wave height and wave energy create
higher berms or ridges.
The degree of sorting of beach sediments can be a useful indicator of
shoreline energy levels. High wave-energy beaches are usually characterized
by well-sorted sediments (i.e., only one size of sediments). In sheltered,
low-energy locations the beach is usually composed of a mixture of sediment
sizes. The higher the energy, the higher the probability of high natural
cleaning rates.
Figure 503-1 indicates the relationship between the factors discussed
above. It can be used to approximate the energy level of various coastline
areas.
Oil
The type and volume of oil and its depth of penetration will influence
the natural cleaning potential of a shoreline. Viscous sticky oils (Class C)
will tend to stick to impervious surfaces like rocks and sea walls, but will
not penetrate sediment beaches in depth. Lighter, less viscous oils (Class
A) will only thinly coat impervious surfaces but can deeply penetrate sedi-
ment beaches. Penetration and burial insulate the oil from surface radiation
and wave energy. Oil will generally penetrate larger grain sediments and
will be buried most readily in areas characterized by high sedimentation
rates (e.g., longshore sand transport, freshwater sediment loading). Thick
viscous oil coatings on impervious surfaces resist wave scouring to a greater
extent than thin, less viscous coatings.
500-4
-------
FETCH
Lor
(>20C
i
Sh
«5C
^g
Ikm)
h
art
km)
PREVAILING
WINDS
Ons
/
Offsl
'lore
L
lore
COASTAL
EXPOSURE
Stra
(Op
t
Inde
(Shell
ght
en)
i
nted
ered)
BERM/RIDGE
HEIGHT
HI
i
Lc
gn
L
w
SEDIMENT
SORTING
Go
A
Pa
od
k
or
ENERGY
LEVEL
H
i
L
igh
k
3W
Figure 503-1. Shoreline energy levels.
500-5
-------
Climate
Prevailing air and water temperatures can effect the persistence of oil
on a shoreline. The colder the air and water temperatures, the more likely
the oil will persist. Rates of physical and biological (microbial) degrada-
tion decrease as temperatures decrease. Conversely, as temperatures rise,
oil becomes more mechanically and biologically susceptible to removal.
Assessment
Accurate estimates of the natural cleaning potential of a shoreline can
be difficult without taking long term field measurements. However, Figures
503-2 (sediment beaches) and 503-3 (non-sediment beaches) can be used to
indicate whether a specific shoreline has a high or low potential for natural
cleaning. A high potential would mean that most of the oil should be removed
naturally from a shoreline in several days to months. A low potential for
natural cleaning means that a majority of the oil would remain on the shore-
line for months to years and that some oil may remain for decades.
500-6
-------
Substrate
Type
O
O
I
Mud
Sand
Gravel
Cobble
Energy
Levels
High
(Exposed)
Low
(Sheltered)
Degree of
Penetration
or Burial
All or
most of oil
exposed
Amount of Oil
Contamination
Extensive oil
penetration
or burial
V
All or
most of oil
exposed
Extensive oil
penetration
or burial
^>
Light
Heavy
Light
Heavy
Light
Heavy
Light
Heavy
Natural
Cleaning Potential
of Shoreline
Hi
1
Lo
gh
w
Figure 503-2. Natural cleaning potential for sediment shoreline.
-------
Ol
o
o
I
oo
Substrate
Type
Rock cliff
Rock ledge
Man-made
structures
Boulders
Energy
Levels
High
(Exposed)
Low
(Sheltered!
Amount of Oil
Contamination
Low
Light thin
coating
High
Heavy viscous
coating
Low
Light thin
coating
High
Heavy viscous
coating
Prevailing
Temperature
Natural
Cleaning Potential
of Shoreline
High
Low
Figure 503-3. Natural cleaning potential for non-sediment type shorelines.
-------
504 SELECTION OF APPLICATION TECHNIQUES, DISPERSANT, AND DOSAGE
Once dispersant cleaning has been deemed acceptable, the proper dis-
persant, application technique, and dosage must be selected for the specific
area to be cleaned. Selection is based on the nature of the surface to be
cleaned and the mode of cleaning, rather than the oil type, which will be
weathered and viscous in most cases.
In general, dispersants are best suited for use on impervious surfaces
such as rock cliffs or platforms, seawalls, docks, etc., but can also be used
on sand or cobble beaches. Manufacturers' recommendations for dispersants
should be reviewed prior to application.
Selection of Dispersant Type
There are two types of dispersants which can be used to clean oil-
contaminated shorelines. These are:
• hydrocarbon base dispersants
• water base dispersants
Table 504-1 indicates the type of substrate on which the two types of
dispersants can be used. Table 504-2 relates the dispersant type to appli-
cation equipment and methods.
Hydrocarbon Base Dispersants. The use of hydrocarbon base dispersants to
clean shorelines is generally limited to impervious surfaces contaminated
with highly viscous or weathered oil. Application to sand, gravel, or cobble
beaches may result in deeper oil penetration of the sediments. Typically,
these dispersants are applied neat and allowed to stand for a short period of
time before agitation by water jets or wave action. Successful use depends
on uniform application, adequate contact time, and agitation of the oil/dis-
persant mixture. The contact time allows the agent to penetrate and loosen
the oil, and the agitation by wave action or water jets ensures thorough
removal and dilution.
Highly viscous or weathered soils may require several applications for
effective removal. Stiff brooms can be used on solid surfaces to work the
dispersant into the oil, thereby increasing effectiveness. Steam may be
beneficial in final removal.
Water Base Dispersants. Water base dispersants are usually applied in
diluted form (1-10 percent in water) through a high-pressure spray system or
fire hose. Their primary objective is to prevent the oil reforming or adher-
ing to other surfaces as the force of the water spray striking the contami-
nated surface provides the mechanism for oil removal. If used undiluted on
unconsolidated surfaces, they may drive the oil deeper into the substrate.
Therefore, application to sand, gravel, or cobble beaches should be uniform
and conducted just prior to the rising tide. Application to seawalls, rock
cliffs, docks, and other impervious surfaces is generally more effective
using very high pressure hydroblasting equipment but can also be accomplished
at lower pressures using fire hoses. For highly viscous or weathered oils,
500-9
-------
TABLE 504-1. DISPERSANT TYPE VERSUS SUBSTRATE TYPE
DISPERSANT TYPE
SUBSTRATE TYPE Hydrocarbon Base Water Base
Mudflats X
Sand/Gravel X
Cobble X
Boulder X X
Rock Platform X X
Rock Cliffs X X
Man-made Structures X X
500-10
-------
TABLE 504-2. EQUIPMENT AND APPLICATION METHODS FOR DIFFERENT DISPERSANT TYPES
DISPERSANT APPLICATION EQUIPMENT DILUTION
TYPE METHOD USED METHOD
Hydrocarbon Applied neat at Hand-held or back- Not Applicable
base low pressure and pack sprayers, low
volume pressure/volume
pumps, single or
multi-nozzle spray
lances, or agricul-
tural spraying equip-
ment (fire pumps,
hoses, and nozzles
for flushing)
Water base Applied in solu- Hand-held or back- Premixed, or
tion at concen- pack sprayers, high diluted through
trations of 1-10%; pressure/volume eduction or
usually at high pumps, injection injection.
pressure and puiaps, fire nozzles
volume. or spray lances, or
agricultural spray-
ing equipment.
500-11
-------
a presoak using hydrocarbon base or concentrate dispersant applied full
strength may be necessary.
The dispersant/water solution can be prepared by premixing, eduction, or
injection into a high pressure water stream. The high pressure nature of the
application system not only delivers the dispersant to the oil but also mixes
it in and removes the dispersed oil from the substrate. Sand, gravel, or
cobble beaches may require repeated applications after every few tidal
cycles. This permits wave action to turn over cobbles or the top layers of
sediment exposing previously untreated oil.
Selection of Dispersant Cleanup Techniques
Several different methods can be used to implement dispersant cleaning
of a shoreline. Table 504-3 lists two techniques and several application
methods for using dispersants on a shoreline. The following factors influ-
ence the selection of a dispersant shoreline cleaning technique:
type of substrate
shoreline energy level
sensitivity of the shoreline to oil and dispersant
type and amount of oil contamination
vehicle access and trafficability on a shoreline
Two decision guides have been prepared to help the user evaluate these fac-
tors for a given shoreline and select the preferred dispersant cleanup tech-
nique. Figure 504-1 discusses sediment-type shorelines, and Figure 504-2
discusses non-sediment-type shorelines.
Implementing Dispersant Shoreline Cleaning
The intertidal zone should be treated just ahead of the rising tide so
that wave action can agitate the dispersant/oil mixture and disperse it into
the sea yet still allow adequate contact time for maximum effectiveness.
Contaminated substrate lying above the high water line should be treated with
dispersant and pushed into the surf zone or flushed thoroughly with seawater.
Field experience involving the use of dispersants in conjunction with
flushing equipment indicates that dispersants do not necessarily improve
cleaning rates but do disperse the removed oil, preventing it from coagula-
ting and penetrating sediments.
Dispersant Dosage
Specific dosage rates for dispersant cleaning of shorelines have not
been developed. Manufacturers' recommendations should be followed initially
and adjusted based on the effectiveness of the cleaning operation.
500-12
-------
TABLE 504-3. DISPERSANT BEACH CLEANING TECHNIQUES
Dispersant applied directly to oil on beach; tidal and wave action
remove dispersed oil.
A. Vehicle. Application of water base dispersant by spray bar from
tank truck or beach vehicle.
B. Manual. Application of water base dispersant by fire hose or
hydrocarbon base dispersant by spray system.
Dispersant applied to oil on shoreline (beach, rocks, sea walls,
etc.) and oily runoff collected.
A. Application of water base dispersant by fire hose or hydrocarbon
base dispersant by portable spray systems to oiled area, collect
runoff.
B. Push loose substrate into stock pile on back shore area, apply
water base dispersant to stock pile and collect runoff.
C. Injection of water base dispersant into high pressure washing
system—collect runoff.
500-13
-------
Shoreline
Energy
Level
sdium \
rV
Medium
to
High
o
o
I
I LOW I
Can
dispersed
oil
remain YCS
in
environ-
ment?
w
2.B Stockpile substrate,
apply dispersant,
collect runoff
Is there
vehicle access
to beach
and is
beach
trafficable
to tracked or
wheeled
vehicles'
NO
YES
Degree of oil
contamination
Surface medium-
heavily
contaminated
Surface lightly
contaminated
1.A Vehicle
application
1 B. Manual
application
1.B.
Manual
application
If oil
contamination
extends beyond
high tide line,
use bulldozer or
front-end loader
to push
dispersant
treated oily
sediments into
surf zone
Figure 504-1. Decision guide- dispersant beach cleaning techniques
for sediment beaches (1.A. etc., refers to techniques
listed on Table 504-3).
-------
Beach Type
Boulder
Rock
Man-Made
Structures
Shoreline
energy
level
Medium
to high
Low
Can dispersed
oil remain in
environment ?
Yes
No
O
o
I
Is stranded oil highly weathered or tar-like?
Yes
No
Amount of oil
contamination
Surface
lightly
contaminated
Surface
heavily
contaminated
1.B. Manual
application
1. B Dispersant
manually applied,
then flushed
2. A. Dispersant manually applied, then
flushed and runoff collected.
or
2 C. Inject dispersant into high-pressure washer.
N,
I/
Amount of oil
contamination
Surface
lightly
contaminated
Surface
heavily
contaminated
2. A. Manual application
of dispersant, then
collect runoff
2. B. Dispersant applied
or manually, then
C. flushed and runoff
collected
Figure 504-2. Decision guide - dispersant beach cleaning techniques for non-sediment
beaches (1.B. etc., refers to techniques listed on Table 504-3).
-------
505 ECOLOGIC CRITERIA
The final consideration in determining acceptability of dispersant use
on shorelines is the relative ecologic effect. Dispersant use is acceptable
when it results in the least overall environmental damage and facilitates the
speediest return to normal conditions. The following criteria can guide
decisions which regard the environmental consequences of dispersant use:
1. Existing Damage. If most or all shoreline organisms are already
coated with oil and the nearshore waters are carrying heavy oil
concentrations, the bulk of damage has probably been done and the
additive effects of dispersant and dispersed oil will probably be
minimal. When evaluating existing damage, it is important to con-
sider the three-dimensional nature of the beach. Often contamina-
tion is restricted to surface coatings; sub-surface or under-rock
habitats may be unaffected. While removing surface contamination,
dispersant treatment may contaminate these lower areas which previ-
ously escaped the incoming floating oil. Chemical dispersion in the
vicinity of emergent or submergent vegetation is not recommended.
2. Contamination of Adjacent Areas. In addition to effects on-site,
dispersant application should be considered in terms of effects on
adjacent areas. The case for chemical treatment may be considered
from two related points of view:
a) In some situations oil leaching from a contaminated site may
pose a threat to a nearby resource or amenity. Any uncontrolled
expansion of the zone of contamination is ecologically undesir-
able.
b) Oil removed by natural processes and by chemical treatment will
ultimately be distributed on adjacent beaches and near-shore
waters. When left to natural processes, removal is usually com-
paratively slow and the resulting concentrations in the surround-
ing environment are low. In addition, the weathering processes
tend to facilitate removal of the more toxic components. In
chemical treatment the removal rate is rapid and local short-term
concentrations of removed material can be expected to be higher.
The toxicity of the dispersant itself should also be considered.
The movement and fate of materials dispersed in the near-shore
environment are not clearly understood. Until the controlling
mechanisms can be evaluated more accurately, shoreline chemical
dispersion should be considered only when rapid mixing and dilu-
tion with receiving waters is assured or when oily runoff can be
collected. Areas with high mixing and flushing rates are typi-
fied by open configuration and/or high tidal variation.
3. Persistence. All forms of treatment are designed to reduce
persistence, and none should be used in situations where they may
result in an increase. Generally, if dispersion results in oil
penetrating shoreline or nearshore sediments, its persistence will
500-16
-------
be increased. Persistence should be considered both in terms of the
initial site of contamination and the ultimate fate of the removed
oil.
Oil has been observed to adhere to suspended sediments and sink.
The effect of dispersant treatment on this phenomena is uncertain.
In areas of high turbidity, sediment sinking of dispersed oil should
be considered possible.
Note: Actual persistence of buried oil should consider the role of
littoral processes. If a shoreline is undergoing seasonal
or storm-related offshore sediment movement, any buried oil
may be quickly removed.
Recovery. Recolonization of a shoreline largely depends on the
suitability of that shoreline for settlement and survival of
recruits. Oil left exposed on the shoreline surface or gradually
released there will inhibit the recovery process. Spores and larvae
that recolonize a polluted shoreline will largely originate from
adjacent unpolluted shores and not from the survivors of that shore-
line. The proximity of such "seed" areas improves the opportunities
for accelerated recovery.
In general, dispersant use should not expand environmental damage if
extensive mortality has already occurred. However, dispersant use
may be desirable if treatment will decrease the persistence of the
oil on the shoreline and encourage the biological recovery process.
500-17
-------
SECTION 600
CRITERIA FOR USE OF SURFACE COLLECTING AGENTS
601 GENERAL
Surface collecting agents (SCA) are defined by the EPA as surface film
forming chemicals for controlling oil layer thickness. By regulating the
thickness, the film formed by the agent temporarily keeps the oil from
spreading excessively. The application of SCA is discussed in Appendix D.
The primary use is to concentrate the oil, thus making physical recovery
more effective. It may also be used to temporarily protect a shoreline by
fending off the oil slick from a particular area.
SCA use requires the verbal permission ot the Federal DCS which may be
granted either in person or by telephone. The OSC may authorize use of an
SCA if:
(1) it will result in the least overall environmental damage or inter-
ference with designated water use.
(2) provide a key element in the most effective system for removing oil
or hazardous substance discharge from the water environment.
The OSC must also ascertain that the prevailing environmental, meteoro-
logical, and oceanographic conditions at the spill site are compatible with
the agent's use.
600-1
-------
602 ENVIRONMENTAL CRITERIA CONTROLLING USE
Limitations on SCA Use
Collecting agent surface tension forces are comparatively weak and
approximately equivalent to those generated by a 3 mph wind or a surface
current of 0.1 knot. Therefore, an SCA cannot keep oil from moving against
most winds and currents. The agent can, however, control oil slick spread in
moderate currents and in winds up to 20-25 mph, thereby facilitating cleanup
and reducing the area of contamination if a slick comes ashore.
SCA effectiveness will lessen with time. A properly applied film can
usually maintain its integrity for a period of several hours although this is
highly dependent on meteorological activity and the surface conditions of the
water. Choppy wave action and wind can break the continuous chemical film
formed by the agent, allowing the oil to resume spreading through the breaks.
Additional applications can prolong the effective containment period.
The effectiveness of SCA is reduced in waters which are heavily con-
taminated with soaps or detergents. In addition, they are ineffective on
oils in a solidified or semisolidified state such as weathered viscous oils,
oils with high paraffin content, or water-in-oil emulsions. Table 602-1
provides a summary of conditions under which the agents are effective and not
effective.
When To Use Surface Collecting Agents
The decision to use a surface collecting agent to control an oil slick
depends on several factors.
Table 602-2 presents a series of questions which can guide determination
of the feasibility of SCA use for a given spill situation. If the answers to
the questions of the checklist are affirmative, then the spill is a good can-
didate for the use of an SCA for oil containment or shoreline protection.
Ecologic Considerations
While SCA have a measurable level of toxicity, they are typically
applied in very low dosages and over limited areas (i.e., along the perimeter
or leading edge of a slick). They also operate at the surface and evaporate
relatively rapidly. (SCA contain carrier solvents that may be partially sol-
uble). Open water application in accordance with manufacturers' recommenda-
tions should not res-ult in concentrations causing quantifiable effects.
Greater ecologic concern should be given to shoreline application, where
direct agent-amenity contact and higher concentrations are possible, espe-
cially with continual or repeated applications. Surface collecting agents
hold promise for the temporary protection of wetlands and mangroves if
applied properly. Since their impacts on vegetation are not well-known, use
should probably be limited to application where significant contamination is
indicated.
A final consideration should be directed to the possible misapplication
of an SCA. If applied seaward of the oil and shoreline, the oil may be
forced ashore greatly compounding cleanup and damage. Wind and tidal shifts
600-2
-------
TABLE 602-1.
CONDITIONS UNDER WHICH SURFACE COLLECTING AGENTS ARE
EFFECTIVE AND ARE NOT EFFECTIVE
Condition
Effective
Not Effective In
Waves
Currents
Wind
Temperature
Oil type
Debris or vegetat.ion
swells up to 4 to 6
ft in height
currents up to 0.1
kt. May be useful
in deflecting oil
from shorelines at
higher currents, or
in controlling the
growth of a slick
moving in a higher
current
winds up to 20-25 mph
air temperature above
pour point of collecting
agent
fluid petroleum oils
breaking waves,
white caps, or
surf
against currents
greater than
0.1 kt
Time
areas with little or
no floating debris
or oiled vegetation
short periods of time
(up to 6 hr)
against winds of
greater than 3 mph
air temperatures
below pour point
collecting agent
weathered viscous
oils, high parafin
oils and water-in-oil
emulsions
areas with floating
debris or where oil
has contaminated
aquatic vegetation
600-3
-------
TABLE 602-2. CHECKLIST FOR DETERMINING FEASIBILITY OF USING SURFACE
COLLECTING AGENTS FOR OIL CONTAINMENT AND SHORELINE
PROTECTION
DETERMINING FACTOR YES NO
1. Are waves nonbreaking and less than
4 to 6 feet in height?
2. Is surface current less than 0.1 knots?
3. Is wind less than 20-25 mph (containment)
or less than 3 mph towards shoreline
(protection)?
4. Is air temperature greater than pour
point of agent?
5. Is spilled oil in a fluid state?
6. Is there an absence of floating debris or
aquatic vegetation in spill area?
7. Are there areas of special biological
significance (i.e., bird nesting areas,
shellfish beds, marshlands, etc.) or
commercial significance (high-amenity
beaches, etc.)?
8. Is an oil skimmer available to collect
contained oil?
9. Is there equipment available to supply
the surface collecting agent?
600-4
-------
can result in the generation of similar problems. Inshore use requires a
clear understanding of its performance and the nature of area to be treated.
Application Rates
Current maximum application rates have been set by EPA at 2 gallons per
linear mile or 1 ounce per 20 feet with allowances for reapplication every
six hours but not to exceed three times in any 24-hour period. An increase
in these maximum rates is currently being reviewed by EPA. Current approved
application rates can be obtained through the OSC.
600-5
-------
603 APPLICATION
SCA can be effective in controlling spilled oil when used in conjunction
with booms and skimmers. If applied in a timely manner to the slick perime-
ter the agent can reduce the amount of oil boom required for slick contain-
ment and concentrate oil in a smaller area for more effective skimming.
However, belt and disc skimmers may lose effectiveness when used in the pres-
ence of SCA. If a disc or belt becomes wetted by a collecting agent, it may
tend to repel oil instead of recovering it. Therefore, when these skimmers
are used on an oil slick surrounded by a collecting agent, they should be
deployed in the middle of the slick and not driven into the slick through the
chemical barrier. Similar precautions should be taken when using sorbents
with an SCA. The sorbents should be placed directly on the oil slick inside
of the chemical barrier and not dragged through the barrier.
In quiet harbor or marina areas SCA can be applied to the water between
the oil and the shoreline, structures, boats, etc. to repel oil until recov-
ery can be implemented. They can be used in inaccessible locations between
ships and under docks by applying the chemical to the water behind the oil,
causing it to move out to areas where recovery techniques can be applied.
General Application Method
Application of SCA should be conducted as follows:
• Apply the agents as quickly as possible. Agents are most effective
when applied during the early stages of a spill when the oil is in
the initial phases of spreading.
• Apply the agents full strength and not diluted.
• Apply the agents as a stream or coarse spray in a narrow path close
to the edge of the oil slick.
• Do not apply the agent to the slick itself. Agents sprayed onto an
oil slick will be ineffective.
Figure 603-1 illustrates methods of applying a collecting agent under
several different conditions.
Selection of SCA Application Techniques
There are several different agent application techniques for controlling
an oil spill. The most common methods incorporate the use of spray units
mounted on airplanes, helicopters, boats, or carried by hand. In the absence
of spray equipment, the agents can be applied using drip pots or squirt bot-
tles. For small spills occurring in semi-confined areas such as docks, har-
bors, estuaries, etc., the collecting agents should be applied with backpack
sprayers or hand-held spray lances.
Moderate to large spills occurring in the nearshore area or out to sea
are best treated with vessel or helicopter mounted spray equipment. Very
large offshore spills may require application by light, fixed-wing aircraft.
Table 603-1 summarizes application techniques in relation to different spill
situations.
600-6
-------
Apply Agent Here
Water Current
••.-•. • • *• -T^'^'*
o»-...<. .•;..•.•; ;.-•..-
^
Do not Apply
Agent Here
Apply Agent
Here
Do not Apply
Agent Here
Shoreline Protection
Shoreline Protection
Apply Agent Here
Do not Apply
Agent Here
Apply Agent Here
Apply Agent Here
Skimmer
Slick Concentration
Windrow Concentration
Figure 603-1. Collecting agent application.
600-7
-------
TABLE 603-1. APPLICATION TECHNIQUES FOR SURFACE COLLECTING AGENTS
o
o
i
00
Surface Collecting
Agent Use
Concentrate oil — agent is
applied to edges of oil
slick to concentrate oil
for subsequent boom contain-
ment or pickup by a skimmer
Move oil from underneath
structures — collecting agent
is applied behind an oil
slick underneath a dock or
wharf to drive oil out from
underneath structure to
facilitate cleanup
Shoreline protection —
collecting agent is applied
in water ahead of an oil slick
Small Spill
1. Back pack or
hand-held
sprayer
1. Back pack or
hand-held
sprayer
1. Back pack or
hand -held
sprayer
Application Technique
Moderate Spill
1. Helicopter
spray
system
1. Hand-held
lance with
chemical
pump
1. Boat spray
system
Large Spill
1. Fixed
wing
aircraft
n/a
1. Fixed wing
wing
aircraft
and on front of the shoreline
area to be protected
2. Drip pots
2. Helicopter
2. Helicopter
-------
APPENDIX A
ANNEX X - SCHEDULE OF CHEMICAL AND OTHER ADDITIVES^
TO REMOVE OIL AND HAZARDOUS SUBSTANCES DISCHARGES
2001 General
2001.1 This Schedule has been prepared
by the U.S. Environmental Protection Agency
pursuant to section 1(2) of Executive Order
11735. This Schedule applies to the waters of
the United States and adjoining shorelines,
the waters of the Contiguous Zone, and the
high seas beyond the Contiguous Zone in
connection with activities under the Outer
Continental Shelf Lands Act or the Deep
Water Port Act of 1974, or which may affect
natural resources belonging to, appertaining
to, or under the exclusive management
authority of the United States (including
resources under the Fishery Conservation
and Management Act of 1976).
2001,2 This Schedule applies to the use of
any chemicals or other additives as
hereinafter defined that may be used to
remove oil and remove or neutralize
hazardous substances discharges. Any
chemical agent or other substance not
specifically defined in this schedule will be
considered by EPA on a case-by-case basis
for use in the removal of oil and hazardous
substances discharges.
2001.3 This Schedule favors development
and utilization of sorbents, skimmers,, booms
and other mechanical control methods to
remote or mitigate oil and remove, mitigate,
or neutralize hazardous substances
discharges from the environment with
subsequent proper disposal.
2001.4 It is the intent of this Schedule that
the use of chemicals and additives to remove
or mitigate the effects of oil or hazardous
substances discharges shall cause the least
overall environmental impact.
2001.5 In implementing this Schedule and
in maintaining its relationship with other
Federal and State agencies, EPA shall
recognize that some States may have more
stringent laws, regulations or written policies
regulating the use of chemicals in the removal
of oil and hazardous substance discharges, in
which case such laws, regulations or policies
shall govern.
2001.6 It has been determined that
because of the overriding need for prompt
initiation of discharge removal actions no
formal permit, as provided for by Sec. 402 of
the Act, shall be required before application
of chemicals to mitigate the effects of a
discharge. The provisions of Sec. 1510.21 (f)
and 1510.36(a)(3) of this Plan shall apply.
2002 Definitions
Materials applied to oil or floating
hazardous substances discharges are defined
as follows:
2002.1 Chemical agents are those
elements, compounds, or mixtures that
disperse, dissolve, emulsify, neutralize,
precipitate, reduce, solubilize, oxidize,
concentrate, congeal, entrap, fix, gell, make
the pollutant mass more rigid or viscous, or
otherwise facilitate the mitigation of
deleterious effects or removal of the pollutant
from the water.
2002.2 Dispersing Agents are those
chemical agents 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.
2002.3 Surface Collecting Agents are
those chemical agents which are a surface
film forming chemical for controlling oil layer
thickness.
2002.4 Biological Additives are
microbiological cultures, enzymes, or nutrient
additives that are deliberately introduced
into an oil or hazardous substance spill for
the specific purpose of encouraging bio-
degradation to mitigate the effects of a spill.
2002.5 Burning Agents are those materials
which, through physical or chemical means,
improve .the combustibility of the materials to
which they are applied.
2002.6 Sinking Agents are those materials
which are applied to oil and hazardous
substance spills to sink floating pollutants
below the water surface.
2002.7 Mechanical removal methods
include the use of pumps, skimmers, booms.
*Council on Environmental Quality. National Oil and Hazardous Substances
Pollution Contingency Plan: Final Revision. 40 CFR Part 1510 (Federal
Register. Vol. 45, No. 55, March 19, 1980).
A-l
-------
earthmoving equipment, and other
mechanical devices.
2002.8 Sorbents are essentially inert and
insoluble materials which are used to remove
oil and hazardous substances from water
through a variety of sorption mechanisms.
Examples include: straw, expanded perlite,
polyurethane foams, reclaimed paper fibers,
peat moss.
2000 Dispersing Agent Program for Spills of
Oil and Applicable Hazardous Substances
2003.1 Authorization for Use of Dispersing
Agents
2003.1-1 Major and medium discharges.
Dispersing agents may be used in any place,
at any time, and in quantities designated by
the OSC when their use will:
2003.1-1.1 In the judgment of the OSC,
prevent or substantially reduce hazard to
human life.
2003.1-1.2 In the judgment of the EPA
RRT member on a case-by-case basis, in
consultation with appropriate State or
Federal agencies, prevent or reduce
substantial hazard to a major segment of the
population(s) of vulnerable species of
waterfowl; or,
2003.1-1.3 In the judgment of the EPA
RRT member on a case-by-case basis, in
consultation with appropriate State and
Federal agencies, result in the least overall
environmental damage, or interference with
designated water uses.
2003.1-2 Minor discharge. The provisions
of section 2003.1-1 shall apply.
2003.2 Special Restrictions on Dispersing
Agent Use:
2003.3.2-1 Chemical agents shall not be
considered for use as dispersing agents
unless technical product data have been
provided and accepted in accordance with
2003.3 except when the judgment of the OSC
the hazards discussed in 2003.1-1.1 are so
imminent that the time delay for obtaining a
dispersant agent that is in compliance with
2003.3 would be excessive.
2003.2-2 Federal officials responsible for
oil and hazardous substance spill response
activities at all levels shall develop effective
programs to insure that dispersants that are
available for use in appropriate spill response
actions are dispersants with adequate
technical data on file with EPA. This effort
will help preclude the avoidance of the EPA
technical data program by manufacturers or
suppliers who might wish to take advantage
of the emergency conditions provision of
2003.2-1.
2003.2-3 For all situations where
dispersants are used, accurate records shall
be kept on dispersant types, brands,
application rates and methods, effectiveness,
environmental impacts, plus any other
pertinent observations.
2003.3 Technical Product Data For
Dispersing Agents
2003.3-1 Technical product data as
outlined in 2003.3-4 on the physical, chemical
and toxicity characteristics of a dispersing
agent shall be submitted to the Oil and
Special Materials Control Division [WH-548),
Environmental Protection Agency,
Washington. D.C. 20460, at least 60 days prior
to the use of the agent. Within 60 days of
receipt of the data, EPA will inform, in
writing, the submitter on the adequacy of the
data provided. If additional information is
requested or EPA desires to perform tests, the
dispersing agent may not be considered for
use until the additional needs have been
satisfied and the submitter so notified.
2003.3-2 Information furnished in
accordance with 2003.3-4 shall be maintained
on file by the Environmental Protection
Agency, Oil and Special Materials Control
Division, (WH-548) Washington, D.C. 20460,
to provide technical guidance to OSCs on the
acceptable circumstances of use and dosage
rates for dispersing agents. Any changes in
the composition or formulation of the
dispersing agent that will affect any of the
data being requested in 2003.3-4 shall be
immediately brought to the attention of EPA
and testing of the agent will be repeated prior
to the use of the revised dispersing agent.
2003.3-3 The acceptance and
maintenance of product data by EPA does
not constitute approval of the dispersing
agent nor does it imply compliance with any
EPA criteria! or minimum standards for such
agents. The OSC will determine which
dispersing agent may be used for a spill event
on a case-by-case basis using all available
information hi making such a decision To
avoid possible misinterpretation and
misrepresentation of the EPA's role in this
technical product data program, the
manufacturer's representatives may use only
the EPA letter advising compliance with
2003.3-4 in any advertisements or technical
literature on the dispersing agent. The EPA
letter must be used in its entirety. Failure to
comply with these restrictions or any other
improper reference to EPA in attempting to
demonstrate EPA approval of the dispersing
agent for use on spills of oil or hazardous
substances shall constitute grounds for
removing the technical product data from
EPA files, which would preclude use of the
dispersing agent except as noted in 2003.2-3
for imminent hazards.
2003.3-4 Required Technical Product Data
2003.3-4.1 Name, brand, or trademark, if
any, under which the chemical agent is sold.
2003.3-4.2 Name, address and telephone
number of the manufacturer, importer or
vendor.
2003.3-4.3 Name, address and telephone
number of primary distributers or sales
outlets.
2003.3-4.4 Special handling and worker
precautions for storage and field application.
Maximum and minimum storage
temperatures to include optimum ranges as
well as temperatures that will cause phase
separations, chemical changes or otherwise
damage effectiveness of the chemical agent.
2003.3-4.5 Shelf Life.
2003.3-4.6 Recommended application
procedure(s), concentration(s) and conditions
for use depending upon water salinity, water
temperature and types and ages of the
pollutants.
A-2
-------
2003.3-4.7 Dispersant Toxicity—Use
standard toxicity test methods described in
EPA Report "Standard Dispersant
Effectiveness and Toxicity Test" (EPA R2-73-
201, May 1973) pages 22-34. This report may
be obtained from the Oil and Special
Materials Control Division (WH-548), EPA,
Washington, D.C. 20460.
2003.3-4.8 Dispersant Effectiveness—Use
standard effectiveness test methods in EPA
R2-73-201, May 1973, pages 11-21.
2003.3-4.9 Flash Point—Select appropriate
method from the following: ASTM—D 56-70;
ASTM—D 92-72; ASTM—D 93-72; ASTM—D
1310-67.
2003.3-4.10 Pour Point—Use ASTM D 97-
66
2003.3-4.11 Viscosity—Use ASTM D 445-
72
2003.3~4.12 Specific Gravity—Use ASTM
01298-67
2003.3-4.13 pH—Use ASTM D1293-65
2003.3-4.14 Ionic Activity—Use
Weatherburn Test as described below:
Ionic activity tests (Weatherburn Test)
Reagents: 1. Dye solution: 0.03 grams
methylene blue, 12 grams concentrated
sulfuric acid, 50 grams anhydrous sodium
sulfate dissolved in water to make a total of
one liter solution.
2. Anionic surfactant solution—0.5%
Aerosol OT (Sodium dioctyl sulfo succinate).
3. Chloroform.
Procedure: 1. Into a 25 ml. test tube, place 8
ml. of dye solution and 5 ml. chloroform. Add
anionic surfactants solution drop by drop,
shaking vigorously between drops and
allowing phases to separate. Continue adding
dropwise until the two layers are equal in
color and intensity viewed in reflected light.
Usually 10 to 12 drops of anionic solution are
required.
2. Now add 2 ml. of 0.1% solution of the
unknown and shake vigorously.
Results: 1. Chloroform phase (lower) is
deeper in color and aqueous phase is mostly
colorless—anionic-is positive.
2. Water phase (upper) is deeper in color
than the chloroform phase—cationic is
positive.
3. Both phases are more or less the same
color—probably a nonionic.
4. If the aqueous phase has become milky
and hence slightly lighter in color, it may still
be nonionic. Soaps do not react in this
procedure. If both anionics and nonionics are
present, the reaction of this test will be
anionic positive.
2003.3-4.15 Miscibility—Use the test
described below which is a modification of
military specification MIL-€-22230 (ships):
One part of the dispersing agent is mixed
with 100 parts of synthetic sea water. The
solution is agitated for one hour and any
visible separation of the dispersing agent
should be noted after this period of agitation.
The test is to be performed with water
temperatures at both 20°C and 0°C. The
synthetic sea water shall be formulated as
follows:
Sodium Chloride (grams) 150.0
Magnesium Chloride, hexahydrate (grams) 86.0
Calcium Chloride dihydrate (grams) _ 9.6
Sodium Sulfate anhydrous (grams) 24.0
Distilled water to make a total of (liters) 6.0
2003.3-4.16 Dispersing Agent Components
Itemize by chemical name and percentage
by weight of each component of the total
formulation. The percentages will include
maximum, minimum and average weights in
order to reflect quality control variation in
manufacture or formulations. At least the
following major components shall be
identified in complying with 2003.3-4.16.
(a) Surface active agents.
(b) Solvents.
(c) Additives.
If requested by the submitter, information
from 2003.3-4.16 will be handled as trade
secrets under provisions of P.L. 90-23, the
Administrative Procedures Act.
2003.3-4.17 Heavy Metal and Chlorinated
Hydrocarbons
Using reliable analytical chemistry
techniques, state the concentrations or upper
limits of the following materials:
Arsenic, cadmium, chromium, copper, lead,
mercury, nickel, zinc, plus any other metals
that may be reasonably expected to be in the
sample. Atomic absorption methods should
be used and the detailed analytical methods
and sample preparation shall be fully
described;
Cyanide using standard colorimetric
procedures;
Chlorinated hydrocarbons. Gas
chromatography should be used and the
detailed analytical methods and sample
preparation shall be fully described,
2003.3-5 Analytical Laboratory
Requirements for Technical Product Data:
2003.3-5.1 The required tests shall be
performed by a qualified laboratory.
2003.3-5.2 The technical product data
submission shall include the identity of the
laboratory, the qualifications of the
laboratory staff including professional
biographical information for individuals
responsible for any tests, and laboratory
experience with similar tests. Laboratories
performing bioassay tests for dispersant or
surface collecting agent toxicity must
demonstrate previous bioassay experience in
order for their results to be accepted. EPA
will not approve the selection of laboratories
by intended submitters of technical product
data prior to submission of the data. It is the
responsibility of the submitter to select
competent analytical laboratories based on
the guidelines contained herein.
2003.3-5.3 EPA reserves the right to refuse
to accept a submission of technical product
data because of lack of qualifications of
analytical laboratory, significant variance
between submitted data and any laboratory
confirmation performed by EPA, or other
circumstances that will result in inadequate
or inaccurate environmental information on
the dispersing agent
A-3
-------
2004 Surface Collecting Agent fTu^.i.;: •-.
Spills of Oil and Applicable Hazardous
Substances
2004.1 Authorization for Use of Surface
Collecting Agents: Major, Medium and Minor
Discharges.
2004.1-1 The OSC may authorize use of
surface collecting agents on a case-by-case
basis when their use will:.
2004.1-1.1 Result in the least overe.U
environmental damage or interference with
designated water uses, and
2004.1-1.2 Provide a key element in the
most effective system for removing uii 01
hazardous substances discharge from the
water environment.
2004.1-2 Mechanism for authorizing ut~,
The OSC may authorize the use of a surfs-e
collecting agent verbally when on scene or by
telephone prior to arriving on scene. In all
cases, the OSC is obligated to comply with
the provisions of 2004.2 prior to making such
authorization. A review of the capabilities
and expertise of the owner or operator or
cleanup contractor prior to the occurence of
the spill incident would be most beneficial in
situations where telephone authorization is
desired or contemplated.
2004.2 Restrictions on Surface Collecting
Agent Use.
2004.2-1 The OSC may authorize the use
of surface collecting agents only after being
informed of the environmental conditions at
the point of intended use. These
environmental conditions include air and
water temperatures, wind conditions, wave
and current conditions, presence and relative
density of debris and other floating matter on
the water, type and condition of the oil or
hazardous substance spilled, special
biological factors such as waterfowl
sanctuaries, wildlife refuges, spawning or
nursery grounds, shellfish beds, swamp
areas, etc., and the availability of removal
equipment that could be employed to remove
the collected material from the water.
Information on environmental conditions
should be evaluated by the OSC from the
standpoint that conditions such as strong
winds, choppy waters, low temperatureg,
debris, and aquatic vegetation can adversely
affect the performance of collecting agents or
complicate further removal operations. The
performance can also vary with types of oils,
or hazardous substances. The agents can be
effective with thin films of light oils but have
little value with thick layers of heavy, \ iscous
oils. The agents should not be used unless
adequate removal equipment is available to
remove the collected oil.
2004.2-2 A chemical agent shall not be
used as a surface collecting agent urle,.*. Ji=
provisions of 2004.3 are complied with and
EPA has informed the manufacturer';,
representative that the product is acceptable
for use as a surface collecting agent.
2004.3 Technical Product Data foi Su,face
Collecting Agents.
2004.3-1 Technical product data as
specified in 2004.3-4 shall be provided to the
Oil and Special Materials Control Division
(WH-548), EPA, Washington, D.C. 20460, at
least 60 days prior to the use of the agent.
The use of existing surface collecting agents
may be authorized by the OSC without
complying with 2004.3 for 120 days from the
effective date of this Annex. Within 60 days
of receipt of the data, EPA will inform, in
writing, the submitter on the adequacy of the
data submitted. If additional data are
requested or EPA desires to perform
additional tests, the surface collecting agent
may not be used until these additional needs
have been satisfied and the submitter so
notified.
2004.3-2 Information furnished in
accordance with 2004.3-4 shall be maintained
on file by the EPA, Oil and Special Materials
Control Division (WH-548), Washington, D.C.
20460, to provide technical guidance to OSCs
on the acceptable circumstances of use,
dosage rates and special problems in the use
of surface collecting agent. Any changes in
the composition or formula I ion of the surface
collecting agent that will affect any of the
data requested in 2004.3 shall be immediately
brought to the attention of EPA and testing of
the agent will be repeated prior to the use of
the revised formulation of the surface
collecting agent.
2004.3-3 EPA will review technical
product data for surface collecting agents and
will issue approvals for agents meeting
certain criteria. At present, the only minimum
criterion established is for solubility which is
described in 2004.13. This criterion classifies
the substance as a surface collecting agent
but is not an indication of the effectiveness or
toxicity of the material. Other product data
such as toxicity, chemical components, and
physical characteristics will be reviewed and,
if the combined effects of these data end
other factors will result in excessive hazard
to the aquatic life, work safety, or other
elements of the environment in the judgment
of EPA, the Agency may refuse to approve
the use of the agent.
EPA may, from time to time, establish
minimum criteria for the data being requested
and may also require additional data to assist
in arriving at a judgment on the
environmental acceptability of collecting
agent usage.
To avoid possible misinterpretation and
misrepresentation of the EPA's role in the
surface collecting agent technical product
data program, the manufacturer's
representatives may use only the EPA letter
advising compliance with 2004.3-4 in any
advertisements or technical literature on the
collecting agent. The EPA letter must be used
in its entirety. Failure to comply with these
restrictions or any other improper reference
to EPA in attempting to demonstrate EPA
approval of the surface collecting agent
beyond that stated in the letter for use on
spills of oil or hazardous substances shall
constitute grounds for removing the technical
product data from EPA files which would
preclude use of the surface collecting agent.
2004.3-4 Required Technical Product Data
2004.3-4.1 Name, brand, or trademark, if
any, under which the surface collecting agent
A-4
-------
is sold.
2004.3-4.2 Name, address and telephone
number of the manufacturer, importer or
vendor.
2004.3-4.3 Name, address and telephone
number of primary distributors or sales
outlets.
2004.3-4.4 Special handling and worker
precautions for storage and field application.
Maximum and minimum storage temperature
to include optimum ranges as well as
temperatures that will cause phase
separation, chemcial changes, or otherwise
damage effectiveness of the surface collecting
agent.
2004.3-4.5 Shelf Life.
2004.3-4.6 Recommended application
procedure(s), concentration(s) and conditions
for us depending upon water salinity, water
temperature and types and ages of the
pollutants.
2004.3-4.7 Surface Collecting Agent
Toxicity—Use standard toxicity test methods
described in EPA Report "Standard
Dispersant Effectiveness and Toxicity Test"
(EPA R2-73-201, May 1973) pages 22-34. This
report may be obtained from the Oil and
Special Materials Control Division (WH-548),
EPA, Washington, D.C. 20460.
2004.3-4.8 Flash Point—Select appropriate
method from the following: ASTM—D 56-70;
ASTM—D 92-72; ASTM—D 93-72; ASTM—D
1310-67.
2004.3-4.9 Pour Point—Use ASTM D 97-
66
2004.3-4.10 Viscosity—Use ASTM D 445-
72
2004.3-4.11 Specific Gravity—Use ASTM
D 1298—67
2004.3-4.12 pH—Use ASTM D 1293-65
2004.3-4.13 Interim Test to Distinguish
Between Surface Collecting Agents and Other
Spill Cleanup Chemicals.
In order to distinguish between surface
collecting agents and other chemical
materials, this interim test procedure was
developed. This test procedure is not an
efficiency test. It is to be used only to
distinguish between surface collecting agents
and dispersants.
Scope
1. Procedure to be used to determine the
solubility in water under standard conditions
of oil spill control chemicals.
Method Summary
2. Five (5) milliliters of the chemical under
test are intimately mixed with ninety-five (95)
milliliters of distilled water, allowed to stand
undisturbed for one hour, and then the
volume of the upper phase is determined to
the nearest 1 milliliter.
Apparatus
3. (a) Mixing cylinder, 100 milliliter
subdivisions and fitted with glass stoppers.
(b) Pipettes: Volumetric pipette, 5.0
millileter.
(c) Timers
Procedure
4. Add 95 milliliters of distilled water
22° C + / - 3° C to a 100 milliliter mixing
cylinder. To the surface of the water in the
mixing cylinder, add 5.0 milliliters of the
chemical under test. Insert the stopper and
invert the cylinder 5 times in 10 seconds. Set
upright for one (1) hour at 22°C+/ —3"C and
then measure the chemical layer at the
surface of the water. The major portions of
the chemical added (75%) should be at the
water surface as a separate and easily
distinguished layer.
2004.3-4.14 Surface Collecting Agent
Components
Itemize by chemical name and percentage
by weight each component of the total
formulation. The percentages will include
maximum, minimum and average weights in
order to reflect quality control variations in
manufacture or formulations. At least the
following major components shall be
identified.
(a) Surface active agents
(b) Solvents
(c) Additives
If requested by the submitter, information
for 2004.3-4.14 will be handled as trade
secrets under provisions of Pub. L 90-23, the
Administrative Procedures Act.
2004.3-4.15 Heavy Metals and
Chlorinated Hydrocarbons
Using reliable analytical chemistry
techniques, state the concentrations or upper
limits of the following materials:
Arsenic, cadmium, chromium, copper, lead,
mercury, nickel, zinc, plus any other metals
that may bs iis the sample. Atomic absorption
methods should be used and the detailed
analytical methods and sample preparation
shall be fully described;
C\ anide using standard colorimetric
prcsed"rc8;
Ch-'n-ip'-Ued hydrocarbons. Gas
chrematography should be used and the
detailed analytical methods and sample
prepare lions shall be fully described.
2004.3-5 Analytical Laboratory
Requirements for Technical Product Data:
Follow stipulations in 2003.3-5
ZOOS Rio logical Additive Program for Spills of
On' and Applicable Hazardous Substances
2005,1 Authorization for use of biological
additives.
2005.1-1 All discharges, the OSC may
authorize the use of biological additives on
water or shorelines only after obtaining the
approval of the EPA representative to RRT.
The manufacturer or supplier of
microbiological cultures or enzymes must
obtain approval from State and local public
health and pollution control officials and
furnish evidence of such approval to the EPA
RRT representative.
2005.2 Special Restrictions on Biological
Additive Use
2005.2-1 Microbiological cultures and
enzyme mixtures shall not be considered for
use as biological additives unless technical
product data have been provided and
accepted in accordance with 2005.3.
2005.2-2 The OSC must be supplied with
the chemical composition and ratios of
A-5
-------
primary nutrients or nutrient additives prior
to seeking approval for their use.
2005.3 Technical Product Data for
Biological Additives
2005.5-1 Technical product data as
outlined in 2005.3-4 on the constituents of a
biological additive shall be submitted to the
Oil and Special Materials Control Division
(WH-548), Environmental Protection Agency,
Washington, D.C. 20460, at least 60 days prior
to the use of the additive. Within 60 days of
receipt of the data, EPA will inform in writing
the submitter on the adequacy of the data
provided.
If additional information is requested or
EPA desires to perform tests, the biological
additive may not be used until the additional
needs have been satisfied and the submitter
so notified.
2005.3-2 Information furnished in
accordance with 2003.3-4 shall be maintained
on file by EPA to provide technical guidance
to OSCs on the acceptable circumstances of
use and application rates for biological
additives. Any changes in the composition of
the biological additive that will affect any of
the data being requested in 2005.3-4 shall be
immediately brought to the attention of EPA,
and testing of the additive will be repeated
prior to the use of the revised biological
additive.
2005.3-3 The acceptance and
maintenance of product data by EPA does
not constitute approval of the biological
additive nor does it imply compliance with
any EPA criteria or minimum standards for
such additives. The OSC will determine
which biological additive may be used for a
spill event on a case-by-case basis using all
available information in making such a
decision. To avoid possible misinterpretation
and misrepresentation of EPA's role in this
technical product data program, the
manufacturer's representatives may use only
the EPA letter advising compliance with
2005.3-4 in any advertisements or technical
literature on the biological additive. The EPA
letter must be used in its entirety. Failure to
comply with these restrictions or any other
improper reference to EPA in attempting to
demonstrate EPA approval of the biological
additive for use on spills of oil or hazardous
substances shall constitute grounds for
removing the technical product data from
EPA files which would preclude use of the
biological additive.
2005.3-4 Required Technical Product Data
2005.3-4.1 Name, brand, or trademark, if
any, under which the biological additive is
sold.
2005.3-4.2 Name, address and telephone
number of the manufacturer, importer or
vendor.
2005.3-4.3 Name, address and telephone
number of primary distributors or sales
outlets.
2005.3-4.4 Special handling and worker
precautions for storage and field application.
Maximum and minimum storage
temperatures.
2005.3-4.5 Shelf Life.
2005.3-4.0 Recommended application
procedure(s), concentration(s) and conditions
for use depending upon water salinity, water
temperature and types and ages of the
pollutants.
2005.3-4.7 Statements on the expected
effectiveness of the additive including
degradation rates and the test conditions and
data on effectiveness.
2005.3-4.8 For microbiological cultures
furnish the following information:
Listing of all microorganisms to species,'
Percentage of each species in the
composition of the additive,l
Optimum pH and temperature range for use
of the additive,
Special nutrient requirements, if any.
Separate listing of the following a'nd test
methods for such determinations: Salmonella,
fecal coliform, Shigella, Staphylococcus
Coagulase positive, and Eleta Hemolytic
Streptococci.
2005.3-4.9 For enzyme additives furnish
the following information:
Enyzyme name(s),
International Union of Biochemistry (I.U B.)
iiumber(s),
Source of the enzyme,
Units,
Specific Activity,
Optimum pH and temperature range for the
use of the additive.
2005.3-5 Laboratory Requirements for
Technical Product Data: Follow stipulations
in 2003.3-5.
2006 Burning Agent Program for Spills of
Oil and Applicable Hazardous Substances
2006.1 Authorization for Use of Burning
Agents
2006.1-1 All discharges. The OSC may
authorize the use of burning agents only
when they will:
2106 1-1.1 Prevent or substantially reduce
imminent threats to human life, limb, or
property;
2006.1-1.2 Result in the least
environmental harm when compared to other
removal or disposal methods.
2006.1-2 Prior to authorizing use under
2006.1-1.2, the OSC must obtain approval of
the EPA RRT representative and all
applicable State and local public health
pollution control officials.
2006.2 Special Restrictions on Burning
Agent Use
2006.2-1 The OSC will evaluate the
suitability of burning agents on a case-by-
case basis. Burning agents should be inert
materials that will not, in themselves, be a
water pollutant. The addition of oils (such as
gasoline or solvents) as an igniter shall be
avoided unless it is necessary under 2006.1-1.
2006.2-2 A technical data program for
burning agents will not be established at this
time.
'If requested by the submitter, these items will b«
handled as trade secrets under the provisions of the
Administrative Procedures Act (Pub. L. 90-23).
A-6
-------
2007 Sinking Agent Program for Spills of Oil
and Applicable Hazardous Substances
2007.1 Authorization for Use of Sinking
Agents
2007.1-1 All Discharges
Sinking agents shall not be applied to
discharges of oil or hazardous substances on
the navigable water of the United States or
the contiguous zone.
2008 Mechanical Methods and Sorben ts
Program for Spills of Oil and Hazardous
Substances
2008.1 Authorization for Use of
Mechanical Methods and Sorbents
2008.1-1 All Discharges
2008.1-1.1 As stated in 2001.3, it is the
policy of this Schedule to favor the use of
mechanical methods and sorbents for
removal of oil and hazardous substances
spills. The OSC has the authority to use or
prohibit specific mechanical methods and
sorbents on a case-by-case basis. The OSC
will select methods and materials that, in his
judgment, will be most effective in
expeditiously removing the spilled material
and mitigating the related damages, and will
minimize secondary pollution from the
removal or mitigation operation. Prior to
authorizing the use of sorbents, the OSC shall
take into consideration hydrographic and
meteorological conditions as well as the
characteristics of the sorbent and the
availability of adequate containment and
removal equipment.
2008.1-1.2 A technical data program for
mechanical methods and sorbents will not be
established at this time.
(FR Doc. 60-821) Filed 3-18-80: 8 45 am]
A-7
-------
APPENDIX B
TECHNIQUES FOR DISPERSION AT SEA
GENERAL
This appendix provides a general description of the major types of
application systems suitable for oil spill treatment at sea. The informa-
tion presented is not meant for use in equipment construction but rather to
describe operation principles and methods for calibration and dosage control.
Detailed information regarding design specifications can be found in the
American Petroleum Institute's Dispersant Application Manual or directly
from equipment manufacturers.
Vessel and aircraft application systems are discussed in this section.
Hand spray equipment has been used for some applications at sea, but is con-
sidered limited in capacity and application rate. Hand spray systems are
described in Appendix D.
VESSEL APPLICATION SYSTEMS
Vessel application systems may be divided into three general categories:
low-pressure spray booms, high-pressure spray booms, and single-jet or fire
systems. The basic types and specifications of vessel systems are listed in
Table B-l.
Vessels suitable for dispersant application must be seaworthy under the
spill conditions, relatively fast, and capable of carrying a reasonable
amount of chemical, either as deck cargo or integral tankage. Ocean-going
tugs, work boats, and some larger fishing vessels generally meet these
requirements. Smaller craft can be used for close-to-shore application and
when surface conditions permit.
Low Pressure Spray Boom-Systems
Low pressure systems (such as the Warren Spring Laboratory [WSL]-type)
are intended for installation on vessels of opportunity, and consist of pump-
ing systems which deliver dispersant solutions through spray nozzles that are
attached to outrigger booms. The nozzles produce flat sprays and are spaced
to overlap slightly at the water surface. Designed to deliver undiluted dis-
persant, these systems operate at low pressures and volumes (<20 psi and <20
gal/min respectively).
Several variations of the WSL-type system have been developed, including
one for offshore use and a light-duty unit for inshore use. Both are
designed to apply hydrocarbon base dispersants (full-strength) or water base
B-l
-------
TABLE B-l. BASIC VESSEL APPLICATION SYSTEMS
System Type
Sprav
Boom
Low-Pressure
Spray Boom
High-Pressure
Single Jet
Spray
Representative
System
WSL-offshore
WSL-inshore
Injection type
(Halliburton)
Eduction type
(Exxon)
Onboard fire
systems
Portable pump
system
Dispersant
Type Application
Hydrocarbon Full strength
Base
Concentrate, 10:1
Water-base
Hydrocarbon- Full strength
base
Concentrate,
Water-base
Concentrate Variable
and Water- dilution
base
Concentrates Variable
and dilution
Water-base
Concentrates Variable
and dilution
Water-base
Concentrates Variable
and dilution
Pump
Parameters
91 1/mln (20 gpm)
Seawater: 20 gpm
Injector: 2 gpm
32 1/mln (7 gpm)
Seawater:
90-100 psi;
300 gpo disper-
sant injector:
variable to 25
psi; 25 gpm
80-100 pel;
100-150 gpm
Variable
Variable
Method of
Dosage Control
Vessel speed;
dosage can be
doubled by
shutting off
one boom
Vessel speed;
dosage can be
doubled by
shutting off
one boom
Vessel speed;
dosage can be
doubled by
shutting off
one boom
Vessel speed;
eductor setting
Vessel speed;
eductor
setting
Vessel speed;
eductor rate;
spray angle
Vessel speed;
eductor rate;
rate angle
External
Mixing
Yes
Yes
Yes
May be
required
May be
required
May be
required
May be
required
B-2
-------
or concentrate dispersants using adaptor kits. The primary components of the
offshore system for full strength application are shown in the schematic
diagram in Figure B-l. The basic system uses a pump which draws undiluted
dispersant directly from a tank or drums, and supplies it to the booms. To
apply water-diluted dispersants, the main pump draws water from the sea while
a second pump injects the dispersant into the seawater stream at a fixed rate
as shown in Figure B-2. (Due to the low flow rate, eductors cannot be used
on this sytem). The booms are mounted to each side of the vessel and sup-
ported by two masts and a series of guy wires. To facilitate mixing, breaker
boards can be towed behind the spray booms to provide mixing energy.
The smaller WSL-type inshore system is essentially a scaled down version
of the offshore system. It is designed for use on small boats having a fully
loaded freeboard of 2 to 2-1/2 feet. The system consists of a single spray
boom extending out both sides of the vessel, pump, breaker boards (optional),
and rigging. The dispersants are applied through two nozzles at a total rate
of 5 to 7 gal/min and pressure of 12 psi. As with the offshore system, water
diluted dispersants can be applied by modification with an adapter kit.
High Pressure Spray Boom Systems
This system is similar in appearance to the low pressure offshore
system; however, the dispersants are applied in an aqueous solution at pres-
sures of 90 to 100 psi and volumes ranging from 80 to 300 gpm. The increase
in application pressure permits use of eductors to introduce the dispersant
and provides greater initial mixing energy. In addition, the spray booms are
typically mounted forward, ahead of the bow wake to insure dispersant-oil
contact without bow wave disturbance. This position also takes advantage of
the mixing energy supplied by the bow wave.
The primary components of these systems include spray booms, a seawater
pump, an eductor or metering pump, a dispersant supply, a mast or other means
of boom support, rigging, and hoses. If a metering pump is used, it must be
coupled to the seawater pump motor or have its own power source. Eductors
require no additional source of power. A schematic of a system using educ-
tors is given in Figure B-3. Systems using metering pumps are similiar to
that shown in Figure B-2.
High Pressure Jet Spray Systems
The single jet spray system is used only with water-base or concentrate
dispersants. The system is similar to the spray boom system except that
single nozzles are used instead of booms with multiple nozzles, and a slight-
ly larger capacity pump may be required. A schematic of a typical single jet
spray system is given in Figure B-4.
Adjustable fire nozzles which can produce sprays from a course stream to
a fine wide cone are generally used. They can be hand-held or attached to
monitors which are operated manually or automatically. A nozzle can be
located at either side of the vessel, preferably ahead of the bow wave, to
increase coverage.
Fire fighting systems are found on many vessels of opportunity and may
be used in place of the portable components of the high pressure jet spray
B-3
-------
Spray
booms
Spray
pump
Flow
meter
Dispersant
tank
Figure B-1. Schematic of low pressure vessel spraying
system — full-strength application.
B-4
-------
Injection or
Metering pump
INJECTION/METERING
PUMP SYSTEM
Spray
booms
Seawater
Figure B-2. Schematic for vessel spraying
system — diluted applications.
B-5
-------
Spray
booms
Spray
pump
Alternate
. connection
EDUCTOR
SYSTEM
Seawater
Figure B-3. Schematic for high pressure vessel spraying system
using eductors to introduce dispersant.
B-6
-------
Injection or
Metering pump
Sea Water
Spray Nozzle
Eductors
Spray Nozzle
Figure B-4. Schematic — high pressure jet spray system.
B-7
-------
system. Simple installation of an eductor in the main line to the nozzle(s)
usually provides all the necessary modification. Figure B-5 shows installa-
tion as used on a small U.S. Coast Guard fire fighting system.
Calibration
To accurately regulate dosage rates, the system must first be calibrated
so the actual output or application rate of dispersant is known. Once cali-
brated, actual dosage can be regulated by controlling vessel speed.
Spray Boom Systems. The first step is to determine the total output of the
system. (Pump output ratings may not reflect actual system output.) The pump
is started and all valves and equipment are set in normal operating position.
The output volume is determined by holding a graduated container under one of
the spray nozzles for one minute or another convenient period. The amount of
liquid collected is multiplied by the number of nozzles to yield the system
output gallons per minute (gpm). This procedure should be repeated for a few
different nozzles and the results averaged. Pressure caa be checked by
installing a pressure gauge on or between the discharge port of the pump and
the spray boom.
In some cases the discharge and/or pressure can be altered to fall
within the desired output specifications. The pump speed may be increased or
decreased until the desired performance is obtained. The speed should not be
altered too much as this will decrease efficiency and may result in pump and
motor damage.
Other methods for adjusting output include: installing gate or pressure
compensating flow control valves, enlarging or decreasing nozzle size, or a
combination of both. It is generally very difficult to change volume without
affecting pressure and vice versa. If pressure is altered significantly, the
spray angle of the nozzles and droplet size should be checked.
The spray angles can be checked by observing the spray overlap when
operating the system at normal volume and pressure. A 10 to 20 percent spray
overlap at the water surface is desired. If there is no overlap, or it is
too great, nozzles may be replaced with ones which have the required spray
angle. The .nozzles should produce coarse (raindrop) size droplets, and never
a mist or fog.
If metering or injection pumps are used to introduce the dispersant into
solution, the pump setting determines the chemical output of the system. If
a standard, low-volume pump is used, it can again be checked and calibrated
by installing a flow meter in the line or by holding a graduated container
under the discharge port of hose for a known period.
Eductors have adjustments which control the approximate percentage of
dispersant in solution. The amount of dispersant introduced into solution is
directly related to the quantity of seawater flow. Figure B-6 allows compu-
tation of the gallons per minute of dispersant in solution at various educ-
tion rates and discharge volumes. Using this figure the eductor can be set
at the percentage that produces the desired amount of dispersant in solution.
B-i
-------
Foam Eductor System
Modified Eductor System
Turrent
Nozzje
Metering
Valve
Check
Valve
Hand
Nozzle
Seachest
Valve
Turrent
Nozzle
Check
Valve
Metering
Valve
Hand
Nozzle
114"
Checkl
Ball Valve \
Valve
Tygon
Tubing
1/2 In
Pump
Seachest Valve
Dispersant
Pump
Figure B-5. U.S. Coast Guard - foam eductor system.
B-9
-------
I
i—>
O
14-
12-
g
3 ion
8-
OC
LU
O.
u. 6
O
Q.
4-
2-
T
25
4% Eduction Rate
3% Eduction Rate
2% Eduction Rate
1% Eduction Rate
50 75 100 125 150 175
TOTAL DISCHARGE VOLUME IN GPM
200 225
Figure B-6. GPM of dispersant in solution at various eduction
rates and discharge volumes.
-------
For absolute accuracy, a flow meter should be installed between the eductor
and the dispersant supply.
Single Jet Spray System. Typically, the output volume of this system can-
not be calibrated directly by physical measurement. A flow meter inserted
inline between the hose and nozzle can monitor total output; if placed
between the eductor and the dispersant supply it will monitor dispersant
flow. Pressure can be determined by installing a gauge inline between the
pump and nozzle.
If the volume is excessive, a bleed line may be installed between the
discharge port of the main pump and the eductor or metering pump. A bleed
line consists of a "T" fitting placed between two sections of hose with a
gate valve coupled at the tail of the fitting. A discharge hose is fitted to
the valve and dropped over the side of the vessel. With the pump operating,
the gate valve is opened permitting water to flow through the hose and back
into the sea. The valve is adjusted slowly until the desired volume and
pressure is attained at the spray nozzle.
Procedures for calibrating metering pumps and eductors are similar to
those described for spray boom systems.
The swath width for these systems can be visually estimated in the fol-
lowing manner: when all system components operating normally and nozzles set
at an arc or manipulated back and forth, the distance the spray reaches on
either side of the vessel should be estimated. The sum of these distances
and the beam of the vessel will give the approximate swath width.
Dosage Control
Dosage is a function of the output volume or application rate of dis-
persant, the swath width, and vessel speed. The recommended dosage for a
given situation can be determined from Section 405.
Figure B-7 provides a means for determining the vessel speed required to
produce a desired dosage. If the dispersant is applied undiluted the pro-
cedure is as follows:
1) Plot the calibrated system output volume on the horizontal axis of
the large graph.
2) Draw a vertical line to the point of intersection with the desired
diagonal dosage line.
3) From that point draw a horizontal line extending through the vessel
speed/swath width graph.
4) The intersection of this line with the vessel swath width indicates
the relative speed necessary to achieve the desired dosage.
For those systems applying diluting dispersants and using an injection or
metering pump, the above procedure is followed with the metering pump output
substituted for the total system output.
B-ll
-------
SWATH WIDTH (ft)
80 . 60 40 20 0
UJ
85
100
1000
E
§>
a.
H
O
•f
0
20
40
eo
80
100
120
140
16°
180
200
220
240
260
280
300
-1%-
•3%
\ V1
Equivalent Dispersant Output or.
Full Strength Application Output or,
Dispersant Injection Rate (U.S. gpm)
EDUCTION RATE
(percent or eductor setting)
Figure B-7. Vessel speed-dosage rate graph.
-------
If an eductor is used to dilute the dispersant, the following procedure
is used:
1) Plot the total system output on the vertical axis of the small,
lower graph.
2) Draw a horizontal line to the point of intersection with the proper
eduction rate curve.
3) From that point draw a vertical line to the point where it inter-
sects the desired dosage line in the large graph. (The point where
the line crosses the horizontal axis of the large graph gives the
equivalent dispersant output of the system).
4) Follow steps 3 and 4 described above for undiluted dispersants.
If suitable vessel speeds cannot be achieved, system output must be
varied.
Example: It is desired to know the vessel speed required for applica-
tion of a dispersant at a dosage of five gallons per acre.
The system uses an eductor set at two percent and has an
output of 100 gpm and a swath width of 40 feet. Using Figure
B-7 an approximate vessel speed of five mph is determined as
required.
AIRCRAFT APPLICATION SYSTEMS
Aircraft application is normally discussed in terms of helicopter
systems, light and medium agricultural systems, and large or heavy air-
craft systems. Aircraft should be used only to apply undiluted dispersants.
Table B-2 lists typical operating ranges of a few aircraft in each category.
General descriptions of each basic application system, calibration proce-
dures, and dosage control are discussed in this section.
Helicopter Spray Systems
Helicopters prefitted to use agricultural spraying equipment are gener-
ally available in most parts of the country. However, agricultural spraying
systems usually produce fine mists or fogs and as such are not directly
suited to dispersant application. Tests have shown that most can be quickly
modifed to produce coarse sprays sufficient for dispersant use by changing
nozzles. Two basic types of helicopter systems exist, the on-board (or
integral) system and the bucket-type system, which is slung below the air-
craft. The systems differ mainly in the method of attachment to the aircraft
and in the type of pump power supply.
On-Board Spray Systems. An on-board system consists of a spray pump
which supplies chemicals from storage tanks to spray booms fixed below the
aircraft. Figure B-8 illustrates a typical system. Depending on the type
of helicopter, the spray pump is powered in one of three ways:
B-13
-------
TABLE B-2. REPRESENTATIVE AIRCRAFT SPECIFICATIONS
(a)
Cruise Cruise Cruise Useful
Speed Range Endurance Pay load
(knots) (naut. miles) (hours) (pounds)
HELICOPTERS
Light
Hughes 300 C
Continental MKV-A
Medium
Bell 206 B
Hughes 500 D
Heavy
Bell 205 A-l
Sikorsky S-GIN
FIXED-WING
Light
Piper Pawnee D-235
Cessna AC wagon
Medium
Grumman G-164B
Emair MA- IB
Heavy
DC-6B
Sup. Constellation
65
65
122
130
106
120
75(0
105(c)
91
105
225
174 (c)
195
81
290
240
270
438
203(c)
256(c)
N/A
N/A
1,375
N/A
3 938
1.5(c) 991
2.3 1,560
2 1,582
2.4 4,387
3.4 6,464
2.l(cl 1389
2.6(c) 1772
3.5 2,980
2.3 3,648
5.5 30,000
5.5 N/A
Liquid(b)
Pay load
Equivalent
(gallons)
111
118
186
188
522
770
165
211
355
434
3,571
3,500
'a^Maximum sling load for helicopters
( 'Assuming specific gravity of 1.0 and does not include spray system weight
'c Figures are for working, not cruise
B-14
-------
of
i—•
U1
LEGEND
(T) Mam boom assemblies
(?) Tank assemblies
(3) Rear boom
(4) Pump and spray valve
(5) Clutch
(6) Spray boom extensions
Figure B-8. On-board helicopter spray system.
-------
• directly by power takeoff from the helicopter engine
• hydraulically by an engine-driven pump
• electrically using the aircraft's electrical system. In some
systems pump output and pressure can be regulated from the cockpit
Helicopter spray systems are generally installed on light and medium air-
craft. Chemical capacity of these systems usually ranges from 50 to 250
gallons. Agricultural spray booms are generally around 40 feet in length
and equipped with downward misting or atomizing nozzles. These nozzles must
be replaced with hollow-cone spray nozzles which produce rain-size drops.
Bucket-Type Spray Systems. Bucket-type systems are modular and
designed to be slung under the helicopter. They consist of a chemical
holding tank, gasoline-powered spray pump, and spray booms which are sche-
matically shown in Figure B-9. The pump is operated at a preset speed and
constant pressure is maintained with a pressure regulator. On and off cock-
pit controls are provided. The entire system is slung beneath the helicopter
using a quick-release hook and an antiyaw device to maintain correct boom
orientation. Chemical capacity of most bucket systems ranges up to 200
gallons, with systems of up to 600 gallons available for large helicopters.
Similar to on-board systems, bucket-type spray systems are generally supplied
with agricultural type nozzles which must be replaced as before.
Fixed-Wing Spray Systems
Fixed-wing aircraft are routinely used for agricultural spraying and can
treat terrestrial areas ranging from a few acres to tens of thousands of
acres in relatively short periods of time. As in helicopter systems, modi-
fications are generally restricted to nozzle changes. The most common type
of equipment are specially modified light agricultural spraying aircraft and
converted multi-engine piston-powered military and commercial aircraft.
Fixed-wing aircraft generally require the use of spotter aircraft to direct
spraying.
Light to Medium Agricultural Aircraft Spraying Systems. These air-
craft have the following ranges of operational capabilities:
working speed: less than 110 knots
working range: less than 500 nautical miles
working endurance: 2-4 hours
useful payload: 1000-2000 pounds
tank capacity: 100-500 gallons
The dispersant solution is carried in an integral tank, usually forward
of the cockpit or in external wing tanks. A pump located below the tank
delivers solution to the distribution or boom system attached either below
the fuselage or directly to the wings. Spray pumps are generally mechani-
cally driven by an air-driven propellor (which provides a pump rate propor-
tional to air speed) (Figure B-10) or by a hydraulic system operated off the
aircraft engine (Figure B-ll). For dispersant modification, the aircraft
B-16
-------
I
I—1
-^1
To boom -
Boom pressure
adjustment
Discharge pipe
Control cable to cockpit
Lifting yoke
Bucket tank
Gasoline engine
Spray pump
Electrically controlled
spray valve
- To boom
Figure B-9. Bucket-type helicopter spray system.
-------
w
I—•
00
LEGEND
(T) Chemical tank
@ Spray pump
(3) Spray control valve
(J) Strainer
(5) Discharge tube
(f) Spray boom
Figure B-10. Light agricultural spray system wind driven pump.
-------
w
I
LEGEND
(T) Hydraulic pump
(5) Spray pump
(D Oil filter
(§) Heat exchanger
^5, Relief valve
(6" Master valve
7 Reservoir
Figure B-11. Light agricultural spray system: hydraulic pump.
-------
must be equipped with spray booms which have replaceable nozzles, and pre-
ferably a boom width approaching the aircraft's wingspan.
Heavy Aircraft Spraying Systems. A variety of heavy commercial and
military aircraft have been converted for large-scale aerial spraying appli-
cations. These aircraft are typically multi-engine piston-powered machines.
Aircraft characteristics include:
• working speed: 100-250 miles per hour
• working range: 500+ miles
• useful payload: 18,000 - 30,000 pounds
• equivalent dispersant capacity: 2,500 - 4,000 gallons
High capacity pumps are necessary for the outputs required by these
large, high-volume spray systems. These pumps are generally driven by one
or more of the aircraft's engines. Dispersant solution is pumped from tanks
within the craft to spray booms attached to the bottom or top of the wings.
System components are interconnected by piping which is valved for turn-
ing the system on and off and recirculating the solutions. The valves are
usually operated from the cockpit and electrically activated. As with many
types of aerial spraying systems, most existing equipment will require modi-
fication.
Calibration
Calibration of aircraft application systems includes consideration of
droplet size and the output volume or application rate.
Droplet Size. Droplet size is critical in aerial application. Very
small droplets may evaporate before reaching the sea surface. Small droplets
are also highly subject to wind drift, complicating control of coverage and
dosage. Excessively large droplets may result in inefficient surface distri-
bution of the dispersant and may penetrate through the slick. Test programs
suggest aerial application is effective when droplets are in the 250 to 1000
micron size range, with the larger end of the range probably being most
effective. Manufacturers' recommendations should be followed when available.
Droplet size can be estimated by performing a test run over land at the
desired speed and altitude, and with the system at normal operation. Non-
absorbent 4 to 5 inch square cards are randomly placed perpendicular to the
flight path. The cards are collected after a single pass and the droplet
splats measured. An average size or range of sizes can then be determined.
It should be noted, however, that the diameter of the splat on the card will
be larger than the diameter of the droplet itself due to the flattening
effect of the droplet striking the card.
The dosage can be field calibrated as mentioned above. The drops on the
cards are not only measured but counted, and the results averaged. Dosage
can be estimated using the formula, D = Nr (4.5 x 10 ), where D = gal-
lons per acre, N = number of drops per square centimeter, and r = droplet
radius in microns.
B-20
-------
Nozzle Selection. Most agricultural spraying systems available for
application of dispersants are supplied with atomizing or misting nozzles.
These nozzles must be replaced with nozzles which produce a coarse spray and
usually a larger output. Test experience indicates that hollow cone nozzles
fitted with cores which impart rotation to the existing flow, produce accept-
able sprays. If the pumping system is adjustable, the pump rate may be
modified until acceptable drop sizes are obtained. To increase drop size,
alternate nozzles may be blocked off, permitting use of fewer, larger bore
nozzles.
Tests also suggest that orienting nozzles directly aft increases both
droplet size and swath width.
At speeds above 120 mph, i.e., heavy aircraft, nozzles may not be
required. Wind shear is sufficient to create uniform spray formation and
satisfactory droplet size. Tests using pipe nipples (facing aft) instead of
nozzles produced acceptable (although less regular) spray patterns of satis-
factory drop diameter (toward the large end of the desired range).
Output Volume. Ground calibration of the output volume is done the
same way as for vessels. The pumping system is operated at working speed
(with water) with a graduated container held under a nozzle for a given time
to collect the discharge. The quantity collected is multiplied by the number
of nozzles to give the output in gallons per minute (gpm). This procedure
should be repeated at several nozzles along the boom and the results
averaged.
Systems using wind-driven pumps, however, cannot be physically cali-
brated on the ground. These pumps must be calibrated by calculation at a
given airspeed, using the pump performance curves supplied by the manufac-
turer or by test application. A pump output at a midrange airspeed should
be used for calculation.
Figure B-12 can be used to estimate required pump capacities at various
air speeds and swath widths. To estimate pump requirements compare the
anticipated range of operating speeds and estimated effective swath widths
(ground width) with the desired dosage. The right hand column can then be
used to estimate pump requirements.
To use this nomogram, draw a line from the calculated ground speed
through the effective swath width to find a coverage rate. From that point
draw a line through the desired dosage rate to the system output column. The
point of intersection gives the required output.
Dosage
Dosage is a function of pump capacity and pressure, effective swath
width, and ground speed. It is recommended that system output be held con-
stant and calibrated as described above. Application should also be held
constant (altitudes of 25 to 50 feet have been shown to be effective).
Dosage can then be controlled by varying airspeed. In cases where it is
not practical to design or modify a system to deliver a determined dosage,
multiple applications may be necessary to achieve the desired effect.
B-21
-------
Requ
Pump (
(9P
Coverage Rate —
(ac/min)
Ground Speed
(mph)
(air speed ± wind factors)
- 300
- 260
- ** Effective
Swath Width
Itr l
- 150
- 100
- 90
- 80
- 70
- 60
- 56
• 50
• 45
- 40
- 35
- 30
• 25
- 20
- 15
11
• 10
• lb
- 20
- 30
- 40
• 50
- 60
- 100
- 150
- 200
• 250
- 300
- 400
B
- 10
A
;
Dosage
(gal/ac)
i- 3 _^
- 4
1- 5
- 6
- 8
- 10
• 12
- 16
- 20
- 30
- 40
- 50
- 60
- 80
- 20
- 15
>- 12.5
- 10
• 8
- 6
. 4
- J
- 2.5
- 2
- 1
- .5
ired
Output
m)
- 2000
- 1600
- 1200
- 10OO
- 800
- 600
- 500
400
- 300
- 250
200
- 150
- 120
- 100
• 80
- 60
- 50
• 40
- 30
- 26
- 20
- 15
E
- .25
Figure B-12. Pump output calculation nomogram.
B-22
-------
The application or air speed required to give a specific dosage can be
determined using Figure B-12 if system output and effective swath width are
known. (The effective swath width is greater than the boom width, typically
by 1.5 to 2 times. Determination of its actual width requires field measure-
ment ) .
Example: A spray system has been calibrated as delivering 40 gpm; the
desired application rate is 10 gallons per acre. The effec-
tive swath width has been determined to be 60 feet. A line is
drawn connecting these points and intersecting column A, where
a ground speed of 35 mph is obtained. Weather reports indi-
cate a headwind of 5 mph in the desired direction. As such,
the required application airspeed is 40 mph.
Field calculation of dosage can be made using the procedure for calibra-
tion of droplet size.
B-23
-------
APPENDIX C
SHORELINE APPLICATION DISPERSANT SYSTEMS
DISPERSANT EQUIPMENT AND PROCEDURES
The type of equipment used to apply dispersants to shorelines varies
with the type of dispersant, the type and amount of oil contamination, and
the application technique selected. The following discussion identifies
equipment suitable for application of dispersant types specified in Section
504.
Hydrocarbon Base Dispersants
Areas with limited contamination can usually be treated with a backpack
or hand-held garden sprayer. Hand-held sprayer lances are generally fitted
with a single, wide-angle nozzle which produces a coarse spray. Larger areas
require a stationary or mobile high-volume pump with dispersant tank and
capable of serving one or more spray lances with long hoses.
Hydrocarbon base dispersants are generally required to treat viscous or
weathered oil. They dissolve or soften coatings which permits their removal
by flushing, high-pressure blasting, or steaming. In some cases, natural
wave action may be sufficient. Only light applications of dispersant should
be made, together with a suitable reaction period before flushing or addi-
tional dosage is attempted. The amount of time should be determined on a
case-by-case experimentation. For thick or heavily weathered deposits,
repeated application may be required.
Water Base Dispersants
Water base dispersants can be applied by several different methods. The
extent of contamination, the type of substrate, the availability of equip-
ment, and the desired effect determine the proper method. Water base disper-
sants can be used to (1) directly assist in removal of oil, or (2) prevent
the reformation of slicks from loosened material. Table C-l lists different
application methods for three types of oil contamination.
Generally, small contaminated areas can usually be treated with a back-
pack or hand-held garden sprayer containing a premixed solution of dispersant
and seawater. After a suitable reaction period, the treated area may require
supplementary flushing. Larger areas are more efficiently treated with spray
lances or fire hoses. If the oil coating is viscous, water base dispersant
can be injected into a high pressure water washing stream (hydroblaster).
Mobile agricultural spraying equipment can be used for extensively con-
taminated flat-lying areas, if eductors or injection pumps are incorporated
C-l
-------
TABLE C-l. WATER BASE DISPERSANT APPLICATION METHODS
Extent and Location of
Oil Contamination
Application
Method
Mixing
Method
small area (vertical or
horizontal
vertical area
large horizontal area
backpack sprayers premixed
hand-held lances premixed
and pumps
injection into induction
hydroblaster
fire hose, fire eduction
pump and eductor
mobile agricultural premixed
spraying system
aerial undiluted
fire hose, fire pump, educted
eductor on vehicle
with salt water tank
C-2
-------
into the system and an adequate seawater storage tank is fitted on board or
towed behind the spraying equipment. Fire pumps, fire hoses and eductors can
also be placed on a vehicle with a salt water storage tank to apply disper-
sants over a large area. Effectiveness may be increased by discing the con-
taminated area prior to treatment or pushing treated material into the surf
thereby facilitating natural cleaning. Shoreline trafficability or lack of
access may preclude use of vehicles on a beach.
DOSAGE CONTROL
Control of the application rate on shorelines can be extremely difficult
and is important when dispersant and removed oil cannot be recovered. Al-
though most individual application systems can be calibrated and regulated,
their operators cannot. The tendency to overtreat areas of higher contami-
nation may be difficult to avoid.
The potential for overdosage is greatest with hydrocarbon base disper-
sants. With water base dispersants, dosage can be controlled to some degree
by limiting the initial concentration. When very low concentrations are used
to prevent removed oil droplets from reforming, overdosage should not be a
major problem. Field instruction and supervision of application personnel
will reduce the potential for overdosage.
Unless oily runoff is collected, shoreline treatment should be limited
to periods just prior to high tide, when rapid dilution of treating agent and
removed material will be greatest.
C-3
-------
APPENDIX D
APPLICATION OF SURFACE COLLECTING AGENTS
APPLICATION PROCEDURES
Manual Application
Manual application of surface collecting agents (SCA) can be done using
commercial backpack sprayers or hand-held garden sprayers with hand operated
pumps and the nozzle of the spraying wand set to deliver a stream or coarse
spray. If spray equipment is unavailable, squirt bottles or other containers
can be used, provided the application of excessive quantities of SCA is
avoided. In any case, SCA should be applied as close to the water surface as
possible to avoid wind losses. SCA should only be applied between the oil
and the area to be protected, or around the perimeter of the oil.
Vessel Application. For moderate to large spills occurring in open water,
application of SCA from vessels of opportunity can be done by modifying low
output vessel dispersant spray equipment. A single dispersant spray boom
should be mounted in a position toward the rear of the vessel so that the SCA
are sprayed on the area least affected by the bow wake and propeller wash.
The inboard nozzles on the spray boom should be shut off or plugged, leaving
only the outboard nozzle open for application. The outboard nozzle will
probably have to be modified to make a stream or coarse narrow spray pattern.
The pumping system may also require modification or a valve placed in the
line to provide a lower flow rate. Vessel speed must be slow enough to pre-
vent turbulent mixing of the SCA by the vessel wake.
Aerial Application. Both helicopters and fixed wing aircraft can be used
to apply SCA. Aerial agricultural spraying systems which are modified for
dispersant spraying can also be adapted for collecting agent application.
Modification of the spraying systems primarily involves changing or plugging
the nozzles to make a single stream or coarse narrow spray. The outboard
nozzles on the aerial spray booms should be shut off or plugged, leaving one
or two inboard nozzles in operation. If a coarse spray is required, the noz-
zles can simply be replaced with those producing the desired spray configura-
tion. For applications requiring a fine stream, the nozzles again can be
interchanged. If the proper nozzles are not available, several other modi-
fications can be made. In some cases the disc or core of the nozzles can be
removed, producing a single stream discharge. If not, a short length of
rubber hose can be fitted around the nozzle, resulting in the spray hitting
the inside of the hose and subsequently running out the end as either a
single stream or a stream of large drops. As a last resort, the nozzles can
be removed altogether, allowing the agent to be pumped directly out the re-
sulting holes.
D-l
-------
For helicopters using the bucket-type application system, there is a
bucket available that does not use spray booms, but rather a single discharge
nozzle located directly under the storage container or bucket. The nozzle
can be modified as described earlier to produce a coarse spray or fine
stream. Bucket-type systems are usually best suited for applying SCA to
moderate size spills as they can be fitted to most helicopters with a minimum
(if any) number of modifications and do not require FAA approval.
When SCA are applied from the air, the aircraft should be as low as pos-
sible and move as slowly as is safe to avoid excessive wind shear and disper-
sion of the agent over a large area. Helicopters are best suited for this
method of application.
Other Application. In cases of oil seepage, persistent leaks, or small
continous spills in an area having unidirectional currents, a drip pot may be
used to apply SCA to the water surface in metered amounts over a long period
of time. A drip pot is a drum or container of the agent fitted with a drip-
type metering device. It'is usually placed on the deck of a stationary ship,
or structure downstream from the source of contamination. The flow should be
adjusted to the stream or current velocity and in quantities that will con-
form to approved application rates.
DOSAGE CONTROL
Dosage control of SCA is simple, provided the output of the system is
known. Output can be determined by operating the equipment at the normal
speed or setting, and holding a graduated container under the discharge
outlet or nozzle for one minute. The amount collected is the system output
given in volume per minute. If multiple outlets are used the amount is
multiplied by the number of outlets.
Once the outlet is known, the dosage can be accurately controlled by
varying the speed at which it is applied. The graph in Figure D-l can be
used to determine the required application speed given the system output
and desired dosage.
D-2
-------
DOSAGE RATES
Q.
.§
Q
111
UJ
8,
<
o
Q.
a.
0.5
1 5 10
SYSTEM OUTPUT (gal/min)
100
Figure D-1. Surface collecting agent application speed guide.
------- |