600284067B
FINAL REPORT
RESPONSE OF CRUDE OIL SLICKS TO DISPERSANT TREATMENT AT SEA
1979 TESTS
by
JBF Scientific Corporation
Wilmington, Massachusetts 01887
Grant No. R806056
Project Officer
Leo T. McCarthy, Jr.
Oil and Hazardous Materials Spill Branch
Municipal Environmental Research Laboratory
Cincinnati, Ohio 45268
This study was conducted
in cooperation with
American Petroleum Institute
Task Force on Dispersed Oil
Washington, D.C. 20037
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
The information in this document has been funded wholly or in part by the
United States Environmental Protection Agency under Grant No. R806056 to
JBF Scientific Corporation. It has been subject to the Agency's peer and
administrative review, and it has been approved for publication as an EPA "
document. Mention of trade names or commercial products does not constitute ,,
an endorsement or recommendation for use.
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ABSTRACT
Four small research oil spills (3.54 m3 each) were made to compare the
physical and chemical behavior of crude oils on the sea with and without
dispersant treatment. Work was performed 90 km southeast of New York Harbor
under a research ocean dumping permit from the U.S. Environmental Protection
Agency (EPA). Each spill was made from a research vessel and was tracked by
vessel and aircraft for several hr. Two crude oils were used; one spill of
each was treated with dispersant after 30 min, and one was allowed to weath-
er naturally as an experimental control. A self-mix dispersant was sprayed
on the two treated slicks from a helicopter that had been fitted with a
spray system delivering droplets whose mean diameter was approximately 1
mm. More than 650 samples of background water, water under the slicks, and
surface water were taken for chemical an-alysis. Sampling continued for 6 to
7 hr after each spill. Aerial photographs were taken, and representative
photographs are presented in this report. Currents and winds were measured,
leading to interpretation of physical transport of the oils. This report
complements earlier work performed in 1975 and 1978.
Chemical analyses and visual observations showed that the dispersant-
treated oil entered the water to a much greater extent than the untreated
oil. Differences between the two crude oils in their response to dispersant
treatment were not apparent, based on amounts of oil found in the water. In
the plumes of dispersed oil, zones of high concentration were consistently
found beneath the upwind and downwind portions of the visible surface oil,
with lower concentrations in the middle.
This report was submitted in fulfillment of EPA Grant No. R806056 by JBF
Scientific Corporation and the American Petroleum Institute under the spon-
sorship of the U.S. Environmental Protection Agency. This report covers the
period January 1, 1979 to December 19, 1980, and work was completed as of
December 19, 1980.
IV
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FOREWORD
The U.S. Environmental Protection Agency was created because of increas-
ing 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 solu-
tion; it involves defining the problem, measuring its impact, and searching
for solutions. The Municipal Environmental Research Laboratory develops new
and improved technology and systems to prevent, treat, and manage wastewater
and solid and hazardous waste pollutant discharges from municipal and com-
munity sources, to preserve and treat public drinking water supplies, and to
minimize the adverse economic, social, health, and aesthetic effects of
pollution. This publication is one of the products of that research and
provides a most vital communications link between the researcher and the
user community.
This report describes field tests in which a chemical dispersant was
applied to controlled oil spills. The findings provide information about
the fate of spilled oil in the treated and untreated conditions.
Francis T. Mayo, Director
Municipal Environmental Research
Laboratory
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CONTENTS
Foreword iii
ADSufdCu « o *> « » IV
Figures vi
Tables" . . . . . . viii
Acknowledgments ix
1. Introduction 1
Purpose 1
ocop^ »* c.
2. Conclusions 3
3. Recommendations 4
4. Experimental Methods .... 5
Participating Organizations 5
Research Permit (EPA Region II) 5
Remote Sensing (NASA) ... 5
Communications 6
Spill Locations and General Conditions 6
General Operations . . . 9
Navigation 9
Current Measurement 9
Air Control and Photography 9
Spilling Oil ..... 10
Spraying Dispersant 10
Sampling and Sample Handling 11
Chemical Analysis .... 13
5. Results and Discussion 15
Physical Behavior 15
Visual and Photographic Observations .... 15
Slick Spreading 23
Slick Drift 23
Chemical Analyses 30
Total Extractable Organics ....... 30
Low-Molecular-Weight Hydrocarbons 41
References 45
Appendices
A. Listing of Data from Exxon Research & Engineering Company
That are not Presented in the Body of this Report .... 46
B. Data From Chevron Oil Field Research Co 51
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FIGURES
Number Page
1 Relationships among participating organizations .... 6
2 Chart showing test area 7
3 Sketch of four-vane drogue 9
4 Schematic of Sampling Stations 12
5 Murban spill that was treated, immediately before treatment
(28 min after oil was spilled) 16
6 Murban spill that was treated, 49 min after treatment
(79 min after oil was spilled) 17
7 Untreated Murban spill, 4 hr 54 min after oil was spilled . . 18
8 Treated Murban spill, 3 hr 7"min after treatment (3 hr
37 min after oil was spilled) 19
9 Untreated Murban spill, 3 hr 7 min after oil was spilled . . 20
10 Untreated La Rosa spill, 15 min after oil was spilled ... 21
11 Treated La Rosa spill, 2 hr 9 min after oil was spilled
(1 hr 39 min after treatment) . 22
12 Treated La Rosa spill, 5 hr 8 min after oil was spilled
(4 hr 38 min after treatment) 24
13 Untreated La Rosa spill, 6 hr 12 min after the oil was
spilled ..... 25
14 Slick Area Growth with Time, Murban 26
15 Slick Area Growth with Time, La Rosa Spills 27
16 Effect of wind and current on slick position: Murban spills . 28
17 Effect of wind and current on slick position: La Rosa spills . 29
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FIGURES
Number Page
18 Total extractable organic matter (mg/1) in water samples
collected during first sample run through treated Murban
crude oil spill 32
19 Total extractable organic matter (mg/1) in water samples
collected during second sample run through treated Murban
crude oil spill 33
20 Total extractable organic matter (mg/1) in water samples
collected during first sample run through untreated Murban
i crude oil spill 35
21 Total extractable organic matter (mg/1) in water samples
collected during first sample run through treated La Rosa
crude oil spill .36
22 Total extractable organic matter (mg/1) in water samples
collected during second sample run through treated La Rosa
crude oil spill 38
23 Total extractable organic matter (mg/1) in water samples
collected during first sample run through untreated La Rosa
crude oil spill . . . . .39
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TABLES
Number
1
2
3
4
5
6
7
8
General Experimental Conditions .......
Dispersant Application Specifications
Sampling Methods Summary ...
Summary of Starting Times of Sampling Runs ....
Background Water Analyses for Total Extractable Organics
Approximate Percent of Spilled Oil Accounted for in Water
Samples
Summary of Carbon Tetrachloride Extractable Organic
Matter in Water from under four Research Oil Spills (mg/1)
Summary of Low-Molecular-Weight Hydrocarbon Concentrations
Page
. 8
. 11
. 13
. 14
. 30
40
. 42
. 43
vm
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ACKNOWLEDGMENTS
Many extraordinary efforts were made by API Task Force members and EPA
staff to assist in the successful execution of this study. Clayton
McAuliffe of Chevron Oil Field Research Company worked with JBF on many
aspects of test design and provided the subsurface sampling system that was
used. In addition, he<' took primary responsibility for guiding sampling
vessels from the command' aircraft, thus freeing the JBF Project Manager for
guiding photographic efforts and for careful logging of events.
Within JBF, acknowledgment must be made of Stephen Greene's persistence
and problem-solving in accomplishing the work aboard ship. Jaret Johnson
was Project Manager.
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SECTION 1
INTRODUCTION
This is the third report on a series of East Coast open ocean oil spill
experiments to determine the physical and chemical behavior of crude oils
spilled at sea. Tests performed in 1975 were sponsored by the American
Petroleum Institute (API). The U.S. Environmental Protection Agency (EPA)
became a partial sponsor, with API, for tests performed in 1978 and 1979.
This report discusses the 1979 tests. During 1978 and 1979, ocean tests
with some similarity to these East Coast tests were performed off the
California coast. Information on all of these test programs is summarized
below:
Four research spills were studied in the Gulf of Maine in 1975,
each including aerial photography, navigational tracking, and
sampling of water and surface oil. These studies were described in
API Publication 4290U) and in papers by McAuliffe(2), and
Johnson, McAuliffe, and Brown(3).
Several research spills were studied off Southern California in
1978. Some of these were'tracked scientifically, as above, and
others were subjected to a variety of attempts at skimming or
dispersant application^).
Four research spills were studied in the outer New York Bight in
1978, each of which was treated with a dispersant. The final
report is complete^), and a paper has been published
recently(6).
Several research spills were studied off Southern California in
1979. These are described in a paper that v^HHtre presented at the
1981 Oil Spill Conference^7). ^A5
Four research spills were studied in the outer New York Bight in
1979. These are the subject of this report.
PURPOSE
The 1979 East Coast tests were made to augment earlier data on the
physical and chemical behavior of two crude oils spilled at sea, as affected
by the application of a dispersant. Independent variables in this experi-
ment were oil type and whether dispersant was applied. So that comparisons
could be made with the 1975 and 1978 tests, the same crude oils were used.
Differences from earlier tests included the time of dispersant application,
1
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the dispersant-to-oil dose rate, and the volume of oil spilled. In addi-
tion, biological tests were performed inside and outside the spill areas by
the University of Southern California (USC).
SCOPE
This report describes the methods, observations, results, and conclu-
sions of the four research oil spill experiments conducted by JBF Scientific
Corporation in the outer New York Bight in 1979. Although JBF closely
coordinated its efforts with those of USC, the biological results and their
reporting are outside the scope of this report. All data and interpreta-
tions relating to physical and chemical fate are provided here.
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SECTION 2
CONCLUSIONS
Average total extractable organics concentrations under the dispersed
slicks at 1, 3, 6, and 9 m were, respectively: La Rosa - 1.9, 1.5, 0.9, and
0.2 mg/H; Murban - 16.3, 0.7, 0.1, and 0.1 mg/£. Because the dispersantroil
volume ratio was about 1:9.4, the above concentrations are probably 10 to
11% dispersant (i.e., when extractable organics are 1 rngA, the dispersant
should be 0.1 mg/Z and the oil 0.9 mg/5,).
Extractable organics concentrations under the untreated slicks were
lower than those under treated slicks, and approximate computations indi-
cated that less than 5% of the untreated oil had entered the water. For the
treated slicks, 50 to 90% of the oil was found in the water column.
The primary differences between the slicks dispersed at 30 min (1979)
and those dispersed in less than 10 min (1978) were that the 1979 dispersant
effects were visually less pronounced, and that the plume shape was more
complex in 1979. Sample analyses consistently showed that the plumes in
1979 had lower oil concentrations in the center than at the upwind and
downwind areas. The 1978 plumes had only one zone of high concentration.
This difference is probably caused by the movement of surface oil away from
the point of discharge in the 1979 tests before the dispersant was applied.
In general, extractable organics concentrations and depth of penetration
into the water were similar to those observed in the immediately dispersed
spills of 1978. In 1979, however, the double areas of high concentration in
each plume resulted in a finding of more oil in the water. Thus, the larger
amount of oil spilled in 1979 resulted in a larger volume of water with a
given oil concentration rather than in higher concentrations.
Low-molecular-weight (Ci to CIQ) hydrocarbon concentrations in the
samples analyzed were above background in only 21% of the samples analyzed.
Several of the samples with elevated concentrations of these volatile com-
pounds were taken beneath untreated slicks where the water's total oil
content was relatively low.
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SECTION 3
RECOMMENDATIONS
Data from this report should be compared with data from laboratory
effectiveness tests. If the laboratory tests are valid and if reliable
scaling relationships can be derived, other oils and other dispersants
should be tested. Thus a data base could be developed to guide dispersant
selection and fate predictions for accidental spills.
Sampling of water beneath oil spills should include stations well out-
side the perimeter of the visible oil so that the edges of the plume can be
defined unambiguously.
The cause for double zones of high concentration in the dispersed oil
plumes should be investigated. This work could probably be done "in a tank
or pool, and should aid future efforts at modeling and predicting the
effects of dispersant application.
Findings of this report and that on the 1978 tests should be coordinated
wih the biological studies for both test series in a unified summary
document.
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SECTION 4
EXPERIMENTAL METHODS
PARTICIPATING ORGANIZATIONS
After JBF and the API had contracted for this project, the U.S. Environ-
mental Protection Agency's Office of Research and Development (EPA/ORD)
became sufficiently interested to participate in funding the project by
means of a grant to the API for part of the cost. In addition to the
research interest by EPA/ORD, EPA's Region II was involved in the regulatory
function of reviewing JBF's application for a research permit under PL92-
532, the Marine Protection, Research, and Sanctuaries Act of 1972.
These and other relationships among the administrative and technical
participating organizations are outlined in Figure 1. Some of the groups
shown in Figure 1 will be discussed later in this section with regard to
test methods; other groups' activities are described here.
Research Permit (EPA Region II)
An application for a research permit was submitted to the Surveillance
and Analysis Division, Marine Protection Program, of EPA Region II on July
19, 1977. A request for clarification and expansion on 18 issues was sent
to JBF by Region II on October 27, 1977. JBF's response, amending the
original application, was sent to Region II on December 19, 1977. Permit
No. II-MA-143-Research was granted by Region II, after public notice and
comment, on June 30, 1978. The permit's effective period was October 1,
1978 through March 31, 1980. JBF's work in both 1978 and 1979 was under
this permit.
Remote Sensing (NASA)
The National Aeronautics and Space Administration (NASA) is developing
technology to monitor various environmental phenomena, including oil spills,
from satellites. Development and testing of the equipment is being per-
formed from aircraft. JBF learned of NASA's desire to monitor planned oil
spills, and contacted the NASA Langley Research Center in August 1978 to
discuss possible cooperation. Subsequent discussions led to extensive
efforts at remote sensing on the 1978 test spills, involving up to four
aircraft under NASA's guidance. A more limited remote sensing effort was
made for the 1979 tests, with one NASA aircraft.
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1
Chemical Analyses
Chevron Oil Field
Research Co.
La Habra, CA
and
Exxon Research &
Engineering Co.
Linden, NJ
Primary Sponsor
American Petroleum Institute
Washington, D.C.
Permitting Authority
U.S. EPA/Region II
Edison, NJ
Biological Work
University of Southern
California
Contributing Sponsor
U.S. EPA/ORD
Edison, NJ
Prime Contractor
JBF Scientific Corp.
Wilmington, MA
Subcontractors
Ship (R/V Albert)
Oceans Unlimited, Inc.
Cambridge, IS)
Command /Photographic
Aircraft
Aero-Marine Surveys, Inc.
New London, CT
Administrative Authority
Reporting Channels
Field Command (Primarily for Safety)
Remote Sensing
National Aeronautics
& Space Administration
Hampton, VA
Dlspersant Application
Island Helicopters, Inc.
Garden City, NY
Figure 1. Relationships among participating organizations.
Communications
Three independent modes of communication were used: aircraft VHF-AM and
two UHF systems. One UHF system (provided for these tests by Texaco) con-
nected the command aircraft with the two ships and with the helicopter for
overall coordination. The other UHF system (provided by Chevron) was used
primarily for the detailed vectoring of the ships to the sampling stations.
SPILL LOCATIONS AND GENERAL CONDITIONS
The area permitted for the tests, and the actual locations of the four
test spills in 1979, are shown in Figure 2. These sites were selected
because their distance from shore and prevailing currents made it unlikely
that any oil would approach shore. They are farther offshore than the 1978
test sites because interference with NASA's remote sensors was present
during 1979 at the 1978 test sites. Finally, no spills were made when wind
was blowing toward shore.
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FOUR TESTS CONDUCTED HERE
Figure 2. Chart showing test area.
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Table 1 shows the general experimental and environmental conditions for
the tests. These conditions appear sufficiently similar that weather is not
considered a variable affecting test results.
TABLE 1. GENERAL EXPERIMENTAL CONDITIONS
Wind
Speed Seas
Date (m/sec) (m)
Water Air
Temp. Temp.
Oil and
Treatment
Spill
Time
(EOT)
Dispersant
Spraying
Time
(EOT)
Oct. 22 0-5 0.3-1.6 16 18-21 Murban, 0848-0852
Not Treated
Murban, 1019-1024 1048-1100
Dispersed
Oct. 23 5-7.5 0.6-1.6 16
16-21 La Rosa, 0845-0852
Not Treated
La Rosa, 1127-1134
Dispersed
1205-1223
On both test days, discharge of the second spill (the one to be treated)
was timed so that the spray helicopter would arrive about 25 minutes later.
The helicopter and the control aircraft thus had some time to view the slick
and coordinate the approach to treatment before the scheduled beginning of
spraying at 30 minutes.
On October 22, 1979 (Murban spills), weather and sea conditions were
ideal, allowing the entire operation to proceed on schedule. On the next
day (La Rosa spills) after the control spill was made, the ceiling and
visibility rapidly diminished on Long Island. A delay in releasing the
second spill resulted because the dispersant-spraying helicopter was unable
to fly to the shoreline (test site weather remained good). The Long Island
weather improved late in the morning, and the second La Rosa spill occurred
2.7 hours after the first spill, rather than the planned 1.3 hours. Site
conditions did not change during the test period, so there should be no
scientific effect of this delay on the test results.
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GENERAL OPERATIONS
Navigation
Both the Albert and the control aircraft used Loran-C for navigation.
Positions were recorded for all sampling stations, for all aerial photo-
graphs, and for any other events of significance. The precision of the
Loran-C readings is approximately + 100 ft in the test area.
Current Measurement
Currents were measured by tracking drogues from the ship and from the
air. Loran-C positions and times were plotted in the .office to derive
current vectors. These drogues were of the customary four-vane configur-
ation, presenting a square drag area to the water (1.2 m oil a side), with a
small staff and flag above the waterline for ease in sighting (Figure 3).
The drogues' buoyancy was such that they followed currents approximately 1
to 2 m below the surface.
Figure 3. Sketch of four-vane drogue.
Air Control and Photography
The aircraft for operational control and photography was provided by
Aero-Marine Surveys, Inc., of New London, CT. A Cessna Model 337G Skymaster
was used, carrying the Aero-Marine Surveys pilot and photographer, and the
JBF Project Director. An API representative guided the research vessels to
sampling stations, and the JBF Project Director guided the dispersant-
spraying helicopter from this aircraft.
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Vertical color photographs were made with a belly-mounted Hasselblad
MK-70 mm camera. Color negative exposures were made on Kodak 8 Color Safety
Film. A second camera recorded readings on a data panel for Loran-C
position, time, altitude, and heading. Both cameras were activated simul-
taneously for each exposure. Altitudes for photography varied from 160 to
1300 m.
Spilling Oil
Each spill was 3.55 m3 (935 gal) of one of the crude oils (Murban from
Abu Dhabi and La Rosa from Venezuela). These were the same crudes used in
the 1975 and 1978 test series.
Each spill was discharged from a 3.8 m3 tank mounted on the stern of
the research vessel through two 7.6 cm diameter hoses. Each hose was 7 m
long, extending over the side to the water surface. The ends of the hoses
were on floats, causing the oil to discharge horizontally on the water
surface. This minimized both evaporation losses due to discharge above the
water, and vertical descent of the oil into the water. The less viscous
Murban (0.83 specific gravity, 39° API) discharged in approximately 5 min;
the La Rosa (0.91 specific gravity, 23.9° API), in 7 min. All "time after
spill" data in this report are based on the beginning of the spill. The
research vessel was moved by its propeller during the spills, approximately
50 m crosswind so that the wind would not cause very narrow slicks. Thus,
immediately after each spill, the crosswind dimension was approximately
twice the dimension parallel to the wind.
Spraying Dispersant
A self-mix dispersant, suitable for application without added mixing
energy (e.g., prop wash or breaker board agitation), was used for all tests.
When dispersant is applied from the air, care is required to produce
droplets that are large enough not to drift from the target, but not so
large that they plunge through the oil film or do not achieve even coverage
of the area. Extensive discussions between JBF and Island Helicopters, Inc.
led to a series of dry-land field tests during 1978 in which various spray
nozzles, aircraft altitudes, and flight speeds were checked. Several mem-
bers of the API Task Force on dispersed oil participated in these field
tests. The result was the set of dispersant application specifications
listed in Table 2. These specifications apply to both the 1978 and 1979
test series.
The treated slicks were allowed to weather for 30 min before treatment.
At T+30 (30 min after beginning the spill), slick areas were approximately 2
ha (4.9 acres). The helicopter carried 379 a (100 gal) of dispersant.
Therefore, dose rates were 1:9.4 (volumetric) or 190 i/ha (20 gal/acre)
(areal).
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TABLE 2. DISPERSANT APPLICATION SPECIFICATIONS
Aircraft:
Spray System:
Nozzles: Type
: Number
Mean Droplet
Diameter:
Bell 206 B Jet Ranger
Belly-mounted Simplex unit with
10-meter boom mounted above skids
Spraying Systems Co. No. D1256
Cone-type teejets
15
Approximately 1 mm
For both tests, dispersant was discharged while the helicopter flew
crosswind, with the wind from the port side of the helicopter. Close obser-
vation by the command aircraft and constant radio contact were used to guide
the helicopter. As in the 1978 tests, the helicopter pilot was unable to
discern the boundary between treated and untreated areas. However, the
command aircraft with its higher alt-itude and observers with experience in
similar operations was able to guide the spray helicopter. Even with this
careful direction, there was some spraying outside the slick perimeters.
This small amount of off-target spraying, along with some wind drift of
dispersant, slightly reduced the amounts of dispersant applied to the oil
slicks reported above.
SAMPLING AND SAMPLE HANDLING
Subsurface water column samples were taken at each station by an array
of small submersible pumps, discharging through polypropylene tubing. The
pumps' internals were of glass-filled polypropylene (Teel Model 1P681).
Pumps were attached approximately 0.5 m below a floating 115 a (30 gal)
steel drum towed 3 m lateral to the bow the the research vessel. In this
position, the ship's bow wave did not cause water mixing at the sample
,3, 6, and 9 m below the water surface, along a taut
kg weight from the bottom of the float. The sample
removed from the water outside the slicks to avoid
surface oil contamination. Surface samples were taken with a small bucket
at all stations except those in untreated slicks.
inlets. These were 1
line suspending a 23
gear was lowered and
Two types of samples were collected: one 1.5 a sample in 1.9 a (0.5
gal) flint glass jug, and completely filled 300 ml (10 oz) "soft drink"
bottles with crown caps. Immediately after collection, 50 ml of distilled-
in-glass carbon tetrachloride (CC14) was added to each 1.9 a jug from an
all-glass dispensing pipet. The jugs were sealed with teflon-lined metal
11
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screw caps, and hand-shaken for about 10 sec to initiate the solvent extrac-
tion of organic matter including the dispersed oil. The CC14 also pre-
vented bacterial degradation of the hydrocarbons. In the laboratory, the
samples were shaken 2 min to complete the extraction.
Prior to sample collection, about 30 mg of mercuric chloride (HgCl2)
was added to each 300 ml bottle to prevent biodegradation prior to analysis.
Each bottle was then flushed with reactor-grade helium and sealed with a
crown cap (polyvinyl chloride seal). At time of sample collection, each
bottle was uncapped, filled to within 3 mm of the top with simultaneous
flushing by reactor-grade helium, and resealed with a crown cap. The small
headspace minimized loss of volatile hydrocarbons to this gas space.
it
The sampling program was designed to obtain water samples at approxi-
mately equally spaced1 stations on transects through the surface slicks and
emulsion plumes. Figure 4 is a schematic diagram of a typical sample run.
A sampling run took about 45 min. The LORAN-C coordinates wre recorded at
every sampling station. Sampling details are summarized in Table 3.
WIND
O SAMPLING STATIONS
Figure 4. Schematic of Sampling Stations
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TABLE 3. SAMPLING METHODS SUMMARY
Type of
Sample
Locations
Preservative/
Extracting Solvent
300 ml: low-molecular
weight hydrocarbons
Surface and subsurface:
"Suffix-A: stations
(see Fig. 4) and
background
1.5 £: Extractable organics Subsurface: all stations 50 ml
Surface: background and 50 ml
in dispersed oil
30 mg HgCl2
For the dispersed slicks, the first sampling run was started a few
minutes after dispersion, and the second after about 1.3 hr. For the un-
treated slicks, the first run started after about 30 min, but the second run
was delayed 4 to 6 hr to allow intensive sampling of the treated slicks.
Times of all sampling runs are summarized in Table 4.
Samples of each crude oil were taken from the spill tank in glass
bottles with teflon-lined screw caps'. In the laboratory these oil samples
were equilibrated with sea water collected outside the spill area, to pro-
vide equilibrium dissolved volatile hydrocarbon concentrations in sea water.
These equilibrium concentrations were a basis for comparison with the test
samples.
Chemical Analysis
Total extractable organic matter was measured on the single 50-ml por-
tion of CC14, with an IR instrument, as absorbancy at 2930 cm-1. This
method measures other CC14 soluble compounds such as organic acids,
esters, and alcohols in addition to the crude oil. These analyses were
performed by Exxon Research and Engineering Co., Linden, N.J.
Volatile hydrocarbons (Ci to CIQ fraction) in the water samples were
analyzed by a gas equilibrium method(8) at Chevron Oil Field Research Co.,
La Habra, CA. Forty ml of Murban and La Rosa oil samples were equilibrated
with 140 ml of sea water collected before the oil spills.^ The oil and water
were hand shaken gently and periodically for 24 hr or more. Mercuric chlor-
ide added at the time of water collection prevented possible biodegradation
of dissolved hydrocarbons during equilibration and prior to analysis. This
water was filtered (from one 50-ml glass syringe into a second) to remove
any separate-phase oil that may have been dispersed during oil-water mixing.
Twenty-five ml of this water was gas equilibrated five times.
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TABLE 4. SUMMARY OF STARTING TIMES OF SAMPLING RUNS
Untreated
Treated
on
Time from
Beginning
of Spill
Time from
End of
Spraying
Time from
Beginning
of Spill
Murban, 30 min
Complete
Transects 4.2 hr
Single Last
Station 6.5 hr
(center of slick)
Single Last
Station
(center of slick)
8.6 hr
< 15 min
1.1 hr
3.2 hr
5.0 hr
5.4 hr
< 60 min
1.8 hr
3.9 hr
5.7 hr
*
La Rosa,
Complete
Transects
28 min
6.6 hr
44 min*
1.5 hr
3.5 hr
1.7 hr
2.5 hr
4.5 hr
6.4 hr
*Command aircraft could not guide ship sooner
accompanying helicopter part way back to shore.
because air safety required
These successive analyses were used to measure the equilibrium concen-
trations of individual C^ to CIQ hydrocarbons for the two crude oils,
and to calculate individual hydrocarbon distribution coefficients.
The water samples collected at the various stations and depths were then
analyzed with a single equilibration using the measured distribution coeffi-
cients to calculate concentrations. This gives sufficient accuracy and
saves time and cost of multiple equilibrations. For those samples that
contained significant separate phase oil, the duplicate sample was filtered
and analyzed. Separate-phase oil contributes hydrocarbons to the gas phase
in concentrations higher than if the hydrocarbons were only in solution.
Method details are given in References 8 and 9.
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SECTION 5
RESULTS AND DISCUSSION
PHYSICAL BEHAVIOR
\
it .
Visual and Photographic Observations
General observations of the spills' physical behavior are discussed here
in preparation for the more detailed data presentations and analyses.
Murban Spills--
These two spills appeared similar within 30 min of the beginning of oil
discharge. The red-brown water-in-oil emulsion ("chocolate mousse") formed
in a patch near the downwind edge of each slick, as typified by Figure 5.
After dispersant was sprayed on one slick, a very faint plume of dis-
persed oil was seen in the water. This plume was less visible than that
from the immediately dispersed Murban spill of 1978, chiefly because the
1979 spill had spread over a much larger area, resulting in a more dilute
dispersed plume. Another difference from that 1978 spill was that in 1978,
surface oil was temporarily absent after spraying; in 1979, some surface oil
was always visible.
In 1979, the treated spill and the control spill developed distinct
differences in appearance after dispersant was applied to the test spill.
For example, at 49 min after the beginning of the spill, the treated slick
showed little or no mousse (Figure 6), but the untreated slick retained
large mousse patches for the entire day (Figure 7). Another visible dif-
ference was the length of the two slicks at similar times after spills. The
treated spill extended to 1550 m length after 3.6 hr, and a surface sheen
could always be seen near a drogue set out at the time and place of spill
(Figure 8). The untreated slick's length at a similar time after being
spilled (3.2 hr) was 900 m (Figure 9), and the visible oil was several
hundred m downwind from the drogue set out at the time and place of the
spill.
La Rosa Spills--
These spills, in their first 30 minutes after discharge, both showed the
usual (for La Rosa) blue-black patches of thick oil near the downwind edge
(Figure 10). After dispersant application, the treated slick gradually
formed into an elongated, uniform area with slightly darker regions at the
upwind and downwind edges. This appearance, at 2 hr 9 min after the spill,
is shown in Figure 11.
15
-------
Figure 6. Murban spill that was treated, 49 min. after
after oil was spilled). Ship is at downwind
Meg. No. 032
Scale 1 cm = 40 m
treatment (79 min.
edge of surface oil
17
-------
Figure 7. Untreated Murban spill, 4 hr. 54 min. after
Mousse is seen as faint light streaks ahead
Neg. No. 048
Scale 1 cm = 49 m
oil was spilled,
of ship.
18
-------
c
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T3
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to
to
s_
0)
cvi
o
r O
Q.
fO Z
-------
Figure 10. Untreated
La Rosa spill,
Neg. No. 087
Scale 1 cm
15 min. after oil was spilled.
= 34 m
21
-------
o
0)
Q.
CO
t. C r-
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-------
Differences between the treated spill and the control spill were similar
to those observed the previous day with Murban. The treated spill was
longer at any given time after spill. For example, scaling the lengths of
the slicks shown in Figures 12 and 13 shows that after 5 to 6 hr, the
treated La Rosa slick was about 1700 m long; the untreated slick, about
800m. The drogue for the treated spill remained with the oil, while the
control slick moved several hundred m downwind from its drogue within a few
hr.
Slick Spreading
Areas of all four slicks were measured by planimeter techniques on
photographs taken at various times." Results for the two Murban spills are
shown in Figure 14, with 1975 and, 1978 Murban data shown for comparison.
Figure 15 shows similar data from...th'e La Rosa spills of 1975, 1978, and 1979.
Several observations can be made, based on these plots and on a review of
the aerial photographs. These observations emphasize the new (1979) data,
because 1975/1978 interpretations have appeared in previous reports(i>^).
o After approximately 1 hr of weathering, Murban spills' rates of
growth begin to differ according to time of treatment. Spills
treated after 30 min or less show rapid growth in area, while
spills that were not treated or were treated after 2 hr show a
slower growth rate.
o La Rosa spills show trends similar to the above observations for
Murban, but the groups are 'not so clearly defined. For La Rosa
spills, the fastest growth rate was for immediate treatment (1978),
followed by the treatment after 30 min (1979) and the spills that
were either not treated or treated after 2 hr.
o For the duration of monitoring these spills (2 1/2 to 6 hr), the
spreading rates appear independent of the amount of oil spilled
(1979 volumes were more than twice those of 1978 and 1975 spills).
Logic would suggest that longer monitoring durations would have
revealed larger areas for spills of greater volume.
Slick Drift
Winds and currents affect the transport of oil slicks across the sea
surface. The 1975 work confirmed several literature findings in that those
spills moved as the vector sum of current and approximately 1% to 3% of the
wind vector, and the 1979 work further substantiated these findings.
Figures 16 and 17 show the transport of surface oil, as well as wind and
current vectors, for the four 1979 spills. During the time of observation
for each spill, winds were fairly consistent. Currents' were also fairly
consistent, probably because the greater distance from shore in 1979 reduced
the tidal component that caused variations in current during the 1978 tests.
In reviewing Figure 17, be aware that the time for which the treated slick
was observed was less than the observation time for the untreated slick.
This fact, not different behavior, accounts for the appearance of a shorter
travel distance for the treated slick.
23
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-------
1
TRUE NORTH
1416
TREATED
1208
^1020
(LOCAL TIME)
1310^
CONTROt
/
/
^0939
/
^0913
SCALE: .
LEGEND:
WIND VECTOR
1853M
(1 NAUTICAL MILE)
1 SEGMENT 2.6 M/SEC (5 KNOTS)
CURRENT VECTOR
». 1 SEGMENT 0.13 M/SEC (0.25 KNOTS)
SLICK POSITION (LEADING EDGE)
JBF 2097
Figure 16. Effect of wind and current on slick position: Murban spills
28
-------
I
TRUE NORTH
1503
CONTROL*'/
f 1355
*
t
TREATED-*-/
1200
1307
' /
/ O
(LOCAL TIME)
SCALE:
LEGEND:
WIND VECTOR
1853M
(1 NAUTICAL MILE)
1 SEGMENT = 2.6 M/SEC (5 KNOTS)
CURRENT VECTOR
V1 '*
>' ^- 1 SEGMENT = 0.13 M/SEC (0.25 KNOTS)
SLICK POSITION (LEADING EDGE)
JBF 2148
Figure 17. Effect of wind and current on slick position: La Rosa spills.
29
-------
Analysis of the velocity vectors for oil, current, and wind showed
results similar to those from the. 1975 and 1978 tests: the effect 'of the
wind on all surface slicks was a vector whose magnitude was approximately 3%
of the wind vector. All four 1979 wind effect vectors were from 10° to
30° to the left of the wind vector. These effects on surface oil movement
were independent of oil type or whether the oil had been treated with dis-
persant. The direction of movement of subsurface oil is discussed later,
where the subsurface plume's fate is inferred through chemical analyses for
known sample positions.
CHEMICAL ANALYSES
Analyses of the water samples provided information that complements the
physical observations for overall indications of fate of the oil and some of
its specific fractions.
Total Extractable Organics
Analyses of the CC14 extracts by infrared spectroscopy were performed by
Exxon Research and Engineering Co. (ER & E). As the discussion will show,
highest oil concentrations and most interesting patterns were found in the
water samples from the two spills that were treated.
As a basis for comparison, analyses of background water samples taken
before each spill are shown in Table 5. These data show the levels of
extractable organics in the absence of a spill. Biogenic materials are the
likely source of these background levels. ER & E noted that the spectra of
samples containing less than about 0.09 mg/a extractable organics were
different from the spectra of the crude oils tested.
TABLE 5. BACKGROUND WATER ANALYSES FOR TOTAL EXTRACTABLE ORGANICS (TEO)
Date Depth (m) Analyses of Duplicate Samples
TEO)
Oct. 22, 1979 (Murban) 0 0.046, 0.039
1 0.077, 0.054
3 0.040, 0.039
6 0.035, 0.047
9 0.034, 0.035
Oct. 23, 1979 (La Rosa) 0 0.071, 0.084
1 0.034, 0.038
3 0.046, 0.037
6 0.065, 0.046
9 0.042, 0.057
Average 0.048
Standard Deviation 0.015
30
-------
The crossed transects of a sampling run permit a three-dimensional
analysis of plumes of dispersed oil (i.e., in crossed vertical planes). In
the 1978 tests, plume definition had been hindered by the small number of
samples collected at 6 and 9 m depths. The 1979 program overcame this
problem and, in a further attempt at better plume definition, changed the
locations of the perimeter stations (1, 6, 7, and 10 in Figure 4) from well
outside the visible oil to the actual edge of the oil.
Murban Spills--
Figure 18 shows the total extractable organic matter concentrations with
depth along the two transects of the first sampling run following the dis-
persant treatment of Murban crude oil. The vertical scale exaggeration is
about 45 X. The contour for 0.25 mg/£ was at approximately 5 m at its
deepest point; for the 1.0 mgA contour, approximately 4 m.
The second set of transects through this spill, with each station occu-
pied about 1 hr after the corresponding station from the first set of tran-
sects, is represented by Figure 19. Dilution with time between these sample
sets had reduced concentrations; all subsurface samples were less than 1
The highest oil concentrations from both of these sample sets were at two
locations: the upwind and downwind limits of the visible oil. The immedi-
ately treated spills in 1978 did not show such multiple zones of high oil
concentrations. Several hypothetical mechanisms in the 1979 tests could
produce this effect, singly or in combination:
o The helicopter spray may have been uneven.
o The upwind plume may have been dispersed naturally before treat-
ment, while the downwind plume was caused by the spray on the heavy
oil that was moved downwind before treatment.
o The upwind slick area, although it contained less oil than the
downwind area, may have contained fractions that were more respon-
sive to the dispersant.
o The upwind plume contained oil that was dispersed at the time of
spraying, while the downwind plume was caused by delayed action of
the dispersant. That is, the surface oil at the downwind end of
the slick was continuing to disperse because of the presence of the
dispersant.
The first of these hypotheses is unlikely, because (as the discussion of
the La Rosa spills will show) similar behavior was found for the dispersed
La Rosa spill. In addition, tests off the California coast during 1978 and
1979 using fixed-wing spray planes and dispersant application by boat found
similar patterns, where the upwind and downwind areas showed higher oil
concentrations than the center of the slick
31
-------
WIND
421 2.04 4.132.22 1.48 .03 1.3O
w»
X
t-
o.
ui
Q
9
.07
08
.08
.08
.08 .08
.08
STATION
TIME AFTER SPILL (MIN)
0 .34
1
53
2
i
60
I
.37 .02
3
65
4
69
1.03
.02
2
**>
X
H
0.
Ul
Q
|*-100M|
JBF 2150
02 -
- .00
.04 -
.08
I
I
.10 .00
.08
.03
7
84
8
86
I
I
9
93
10
96
{INTERSECT)
.10
.08
.06
.06
5
72
6
75
Figure 13. Total extractable organic matter (mg/1) in water samples
collected during first sample run through treated Murban
crude oil spill. Vertical exaggeration about 45 X.
32
-------
1.28 .80
ui
a
.06
.06
STATION 1
TIME AFTER SPILL (MIN) 108
.08
.28
2
112
v
X
a.
ui
a
f«-100M-*|
JBF 2151
.88 8.87 1.18 2.22
08 .04
.03 .08
.08 .08
3
116
.80
4 5
120 123
.99 .88 .72 .44
.28
.04-
.10
.04 .06 .03 .02-
.06
.03 .03 .02 .02
7
136
8
137
I
(INTERSECT)
9
141
10
143
WIND
.43
28 -
38 H
.07
6
126
Figure 19. Total extractable organic matter (mg/x,) in water samples
collected during second sample run through treated Murban
crude oil spill. Vertical exaggeration about 45 X.
33
-------
Rigorously separating the possible contributions of the other three
hypothetical mechanisms is not possible with the data available. One piece
of evidence supporting the second listed hypothesis (some natural dispersion
before treatment) is available, however. At station 9 in the control spill
at 61 minutes after the spill, the following concentrations were found at 1,
3, 6, and 9 m depth: 2.8, 1.96, 4.6, and 0.65 mg/i. Figure 20 shows con-
centration contours for this sample set. Although the high concentration
area is small, the two transects are consistent in their indication of oil
concentrations well above background in the vicinity of stations 4, 5, and
9, near the upwind edge of the slick. The concentrations and depths are
similar to those shown for the upwind plume area in Figure 18, suggesting
that the upwind plume in the treated spill may be at least partly caused by
natural dispersion before dispersant application. One complicating factor
here, in the first spill, is that the Cape Henlopen was having difficulty
maintaining station; the high values may have been caused by excessive
propeller action.
Quality control (QC) samples were taken under the dispersed Murban
spills on each transect after stations 3 and 8. These were not rigorous
duplicates because they differed in time (1-2 min) and space (30-60 m) from
the station 3 or 8 samples. The analyses for these QC samples are shown on
Figures 18 and 19, as the values between Stations 3 and 4, and Stations 8
and 9. They confirm the validity of the data upon which the concentration
contours are based.
The movement of perimeter stations to the edge of the visible oil often
caused poor resolution of plume boundaries. Figures 16 and 17 show that all
stations were inside the plume (well above background). The 1978 work,
however, showed that the plumes did not extend beyond the visible oil perim-
eter more than about 20-40 m. Therefore, it is probably valid to assume
that the perimeter stations in 1979 were within this distance of the edges
of the dispersed oil plume.
La Rosa Spills--
Figure 21 shows the extractable organic matter concentrations for the
treated La Rosa spill for the first sampling run, in a similar manner to the
plot of Figure 18 for Murban. The maximum penetrations for concentrations
of 0.25 through 2 mg/& were all between 6 and 9 m depth. The 4 mg/a contour
was between 3 and 6 m deep. The penetrations of the concentrations contours
are somewhat deeper than those for Murban at the upwind end, but not so deep
at the downwind end of the spill area. The finding of highest oil concen-
trations at the upwind and downwind ends of this slick concurs with the
visual observations discussed earlier. A few samples shown in Figure 21
have spuriously low values. These are primarily the quality control samples
taken between stations 8 and 9. At this time, aerial photographs show the
Albert and the Cape Henlopen to have been quite close to each other. These
samples may therefore represent some clean water pumped into the plume by
the Cape Henlopen's propellers. All other sets of QC samples for this spill
lend credence to the results. The very low value for the 1-m sample at
station 7 represents a 1.5-2, bottle that was found to contain only CC14,
unlike all other samples that were brought to shore containing both CC14
and water phases. The reason for this anomaly is unknown, but the value
should be disregarded.
34
-------
WIND
o.
ui
o
STATION
TIME AFTER SPILL (MIN)
(*-100M|
JBF 2152
.09
.04
.06
.04
.12
.10
.04
.08
.08
.08
.03
.06
1
27
2
29
3
32
4
35
2
^
X
K
o.
UJ
o
.06
.06
.18
.06
.09
1.86 .08
.06
.06
5
39
.06
.06
.04
.66 .06
7
54
8
56
9
61
(INTERSECT)
10
62
12
.02
6
43
Figure 20. Total extractable organic matter (mg/z) in water samples
collected during first sample run through untreated Murban
crude oil spill. Vertical exaggeration about 45 X.
35
-------
WIND
549 .90 3.6S 2.9 2.50 7.94 3.14
2
x
0.
Ul
a
.06
.12
.05 .06
.04 .06 .10
.05 .06
STATION 12 3 456
TIME AFTER SPILL (WIN) 102 105 109 114 117119
2.46
.93.23 .16
2
X
a.
ui
a
-HJIOOM)* 9
JBF 2153
.01
1.79
.47
.07
.06.06 .06
7 8 ,9 10
128 133 136 138
(INTERSECT)
Figure 21. Total extractable organic matter (mg/a ) in water samples
collected during first sample run through treated La Rosa
crude oil spill. Vertical exaggeration about 45 X.
36
-------
Results of the second sampling run for this spill are depicted in
Figure 22. The areas of relatively high oil concentrations upwind and
downwind are evident, as is the fact that the crosswind transect passed
between these two areas.
Of the samples from under the untreated La Rosa spill, only two con-
tained extractable organics in excess of 0.3 mg/i. A value of 2.1 mg/a was
found at the 1-m sample, station 2, first transect. Concentrations between
0.1 and 0.2 mg/£ were found in 16 of the 40 samples taken on this set of
transects (Figure 23).
Sampling runs performed more than 4 hr after each spill revealed much
lower concentrations than the sampling runs discussed here. Data from the
later runs are presented in Appendix A.
Comparisons Among Tests--
For each crude oil tested, the difference in oil concentrations between
treated and untreated spills is dramatic. To quantitate these differences,
mass balance computations were performed. The results of these computations
allow comparison between crudes as well as between treated and untreated
behavior of each crude.
Because of the irregular shapes of the concentration contours, simple
geometric shapes could not be assumed as they were in analyzing the 1978
data. (The analysis of 1978 data assumed pyramid shapes for contours.) In
addition, the poor definition of the edges of plumes in the 1979 data re-
quired assumptions and estimates about the shape of contour lines returning
to the sea surface at the plume edges. Specifically, it was assumed that
all concentration contours met the sea surface 50 m outside the edge of the
visible oil.
Amounts of oil in the water were computed, using the following procedure.
For Figures 18 through 23, the area bounded by the concentration
contours, or isopleths, in the longer transect was measured with a
planimeter. Because the crosswind transects often missed the areas
of highest oil concentration, it was assumed that the crosswind
plume shape at all points was an inverted triangle whose nadir was
the isopleth in the logitudinal direction. The volume bounded by
each isopleth was therefore computed by multiplying the measured
logitudinal plane area by one-half the average width of the visible
oil.
The amount of extractable organic matter within each volume was
determined by multiplying the volume by the concentration, with
appropriate dimensional conversions.
Double accounting was avoided by using the incremental volumes and
concentrations between isopleths, and summing the results.
37
-------
3.06 .88
X
o.
Ill
Q
9
.08 .07
.08 .14
STATION 1 2
TIME AFTER SPILL (MIN) 151 158
.10 .13
.36
WIND
1.8 2.2
.07 .07
.08 .08
.08 .04
.00
.08 .04
.00
.00 .07
3
163
172
5 6
177 181
.18
.08.14.08 .08
2
^*
X
H
0.
UJ
O
J100MJ*
JBF 2154
.12
.11
.12
7
188
.07.08.03.08 -
.08 .08 .08 .06
.06 .06 .08 .08
.08.06 .07 .08
8 9 10
190 193 197
(INTERSECT)
Figure 22. Total extractable organic matter (mg/2,) in water samples
collected during second sample run through treated La Rosa
crude oil spill. Vertical exaggeration about 45 X.
38-
-------
WIND
2
z
Q.
IU
Q
9
.Oe
.08
.08.06 .tO.3010 .07
.08 .06
.06 .10 .09 .10
STATION 1 2 3
TIME AFTER SPILL (MIN) 28 30 33
0.
Ul
Q
100MH
JBF 2155
- .07
- .08
.10
.07
.06
.10
.08
.06
7
51
4 5
35 38
6
41
.10 .09 -
.10 .10 -
.08 .09 -
.08 .06
8
52
(INTERSECT)
9 10
55 57
Figure 23. Total extractable organic matter (mg/£ ) in water samples
collected during first sample run through untreated La Rosa
crude oil spill. Vertical exaggeration about 45 X.
39
-------
The results should be used with great-caution as to absolute quantities
of oil in the water but the relative amounts for different oils and treat-
ments should be useful for comparisons because all computations used the
same assumptions. The reasons for the approximate nature of the absolute
oil quantities include:
The isopleths represent changes in time as well as position. Only
the vertical samples at a given station were simultaneous. Sta-
tions were occupied sequentially.
The approach to computing volumes within each isopleth was very
approximate, especially for the assumption of a triangular cross-
wind plume shape. Another critical assumption was jthat the iso-
pleth described by the logitudinal transect represents the most
concentrated part of the plume.
Results are shown in Table 6.
TABLE 6. APPROXIMATE PERCENT OF SPILLED OIL
ACCOUNTED FOR IN WATER SAMPLES
Crude Oil Type Condition
Treated Control
1st Transect 2nd Transect
Murban 50-90** 6*** < 5*
La Rosa 60*** 2**** <1*
*25 to 60 min after spill.
**50 to 100 min after spill.
***100 to 150 min after spill.
****151 to 197 min after spill.
Table 6 yields several interesting observations and comments:
The first sampling run through treated Murban crude gives a range
of reasonable results based on the average concentration used for
the volume within the 2 mg/& isopleth (Figure 18). An average
concentration of 18.3 mg/2, would account for all the oil; an aver-
age of 14.2 mg/£ would account for 50%. of the oil.
Even though the first transect through treated La Rosa was about 50
min later than the first transect through treated Murban, approxi-
mately the same amount of oil was found.
40
-------
Comparing the first transect through treated La Rosa with the
second transect through treated Murban (samples at similar times),
much more oil was found in the La Rosa plume. This observation may
be caused by more evaporation from the Murban plume, less accurate
sampling locations for the Murban plume, or more lateral dispersion
of the Murban plume. This last factor would result from the fact
that any second run through a plume, regardless of plume age,
attempts to define a plume that has been subjected to much propel-
ler action from the two ships. This propeller wash could have
swept dispersed oil away from the main visible mass of oil being
sampled. The most likely cause for finding less oil on the second
transect is this difficulty in sampling enough stations over a
large enough area.
In addition, it should be noted that the percentage dispersion found in
the first transects compares roughly with that found after immediate treat-
ment of these oils in 1978. Therefore, weathering within the first 30 min
appears not to affect these oils' capability to be dispersed.
Summary--A summary of the total extractable organic matter in water
under the four research spills is shown in Table 7. It includes only values
exceeding 0.10 mg/ji (approximately two times background). Untreated oil
dispersed naturally in the water to a lesser extent than chemically treated
oil, as preceding discussons have shown.
Comparing the data in Table 7 for the two dispersed spills shows a trend
for La Rosa to have higher oil concentrations at the 3, 6, and 9 m depths,
while Murban in the first sampling run showed higher concentrations at 1 m
than La Rosa. This apparent difference may be caused by the greater buoy-
ancy of Murban crude.
Low-Molecular-Weight Hydrocarbons
One hundred and four samples for GC analysis were collected at "suffix
A" stations (Figure 4). Of these, 58 were selected for analysis based on a
likelihood of finding hydrocarbons, as suggested by the previous IR analysis
for total oil. Of these 58 samples, 23 were found to have concentrations
above background. These data, as well as those from the biology ship's
samples, are listed in Appendix B.
The small number of samples with concentrations above background results
partly from the weathering of these spills before treatment; low-molecular-
weight hydrocarbons that might have been dispersed were allowed to evaporate
for 30 min before dispersant treatment.
In an attempt to interpret these limited data, Table 8 has been pre-
pared. The table classifies the GC samples according to the amounts of
total oil found by IR in samples taken nearby in time and space. As the
table shows, the three samples with the highest TEO values also showed
elevated concentrations of C^ - C^Q hydrocarbons. In waters containing
less than 1 mg/jt TEO, no trends were apparent.
41
-------
TABLE 7. SUMMARY OF CARBON TETRACHLORIDE EXTRACTABLE ORGANIC
MATTER IN WATER FROM UNDER FOUR RESEARCH OIL SPILLS
(mg/a)
Oil Sample Sample
Condition Depth (m) Run No.
Not Dispersed 1 1
2
3 1
2
6 1
2
9 1
2
Dispersed 1 1
at 30 min 2
3
3 1
2
3
6 1
2
3
9 1
2
3
N**
6
2
3
0
6
1
1
0
12
8
8
12
7
5
4
4
1
1
1
0
Murban
Maximum
2.8
0.16
2.0
-
4.6
0.10
0.65
-
186
0.80
0.35
2.2
0.39
0.28
0.19
0.53
0.10
0.10
0.25
Mean
0.61
0.14
0.75
-
0.94
0.10
0.65
-
16.3
0.31
0.16
0.67
0.24
0.17
0.14
0.22
0.10
0.10
0.25
N**
6
3
5
3
4
0
2
0
10
6
7
11
6
6
9
2
3
3
2
1
La Rosa
Maximum
2.1
0.12
0.13
. 0.15
0.30
-
* 0.10
-
7.35
2.49
1.05
6.50
2.23
0.46
3.38
1.02
0.36
0.47
0.14
0.11
Mean
0.47
0.11
0.12
0.13
0.15
-
0.10
-
1.88
1.17
0.47
1.47
0.72
0.25
0.86
0.57
0.23
0.23
0.13
0.11
*Average background concentrations (mg/£): 1 m, 0.050; 3 m, 0.041; 6 m,
0.048; 9 m, 0.042. Four background samples at each depth.
**Number of samples > 0.10 mg/£.
42
-------
TABLE 8. SUMMARY OF LOW-MOLECULAR-WEIGHT
HYDROCARBON CONCENTRATIONS
Approximate
Total Extractable
Organics (mg/£)
(Based on isopleths,
Figs. 16 through 21)
>1.0
0.7-0.9
0.2-0.5
<0.2
Number of
Samples
Analyzed
by GC
3 (All Treated)
4 (All Treated)
6 (Treated)
1 (Untreated)
15 (Treated)
9 (Untreated)
Total Ci -
Hydrocarbons
Range
1.89-5.73
b*-1.75
b-2.57
1.64
b
b-3.85
C10
Mean
3.4
1.2
1.5
1.6
b
1.6
*b = background (approximately 1 ug/fc).
43
-------
It should be noted, however, that samples from under control slicks,
while generally low in TEO, showed relatively high levels of GI - CIQ
hydrocarbons. Implications of this observation are uncertain, because these
samples were closer to the time of spill than the samples from treated
spills shown in Table 8 (by about 30 min). If the time factor is not impor-
tant, the data may suggest that oil in the water under untreated spills
contains a higher percentage of volatiles than the oil in water samples from
dispersed spills. In other words, dispersants may enhance evaporation of
low-molecular-weight hydrocarbons from crude oil slicks.
44
-------
REFERENCES
1. JBF Scientific Corporation. Physical and Chemical Behavior of Crude Oil
Slicks on the Ocean. Publication 4290, American Petroleum Institute,
Washington, D.C., April 1976. 98 pp.
2. McAuliffe, C.D. Evaporation and Solution of C2 to CIQ Hydrocarbons
from Crude Oils on the Sea Surface. In: Fate and Effects of Petroleum
Hydrocarbons in Marine Ecosystems and Organisms, D.A. Wolfe, ed., Per-
gamon Press, New York, 1977. pp. 363-372.
3. Johnson, J.C., C.D. McAuliffe, and R.A. Brown. Physical and Chemical
Behavior of Small Crude Oil Slicks on the Ocean. In: Chemical Disper-
sants for the Control of Oil Spills, ASTM STP 659, L.T. McCarthy, Jr.,
G.P. Lindblom, and H.F. Walter, eds., American Society for Testing and
Materials, 1978. pp. 141-158.
4. Smith, D.D., and G.H. Hoiliday. API/SC-PCO Southern California 1978 Oil
Spill Test Program. In: Proceedings of the 1979 Oil Spill Conference,
Publication 4308, American Petroleum Institute, Washington, D. C.
pp. 475-482.
5. JBF Scientific Corporation. Response of Crude Oil Slicks to Dispersant
Treatment at Sea: 1978 Tests. American Petroleum Institute, Washing-
ton, D.C., December 1980, 78 pp.
6. McAuliffe, C.D., J.C. Johnson, S.H. Greene, G.P. Canevari, and T.D.
Sear!. Dispersion and Weathering of Chemically Treated Crude Oils on
the Ocean. Environmental Science and Technology, 14:1509-1518, 1980.
7. McAuliffe, C.D., et al. The 1979 Southern California Dispersant Treated
Research Oil Spills. In: Proceedings of the 1981 Oil Spill Conference,
American Petroleum Institute, Washington, D.C., pp. 269-282, in press.
8. McAuliffe, C.D. GC Determination of Solutes by Multiple Phase Equili-
bration. Chemical Technology, 1: 46-51, 1971.
9. McAuliffe, C.D., et al. The Chevron Main Pass Block 41 Oil Spill:
Chemical and Biological Investigations. In: Proceedings of the 1975
Conference on Prevention and Control of Oil Pollution, American Petro-
leum Institute, Washington, pp. 555-566
45
-------
APPENDIX A
Listing of data from Exxon Research & Engineering Company
that are not presented in the body of this Report. -
Crude Condition Sample Station
Extractable Organics
Time After in Water (mg/1)
Spill Om 1m 3m 6m 9m
Murban Not Treated 171
172
173
174
175
176
177
178
179
180
181
182
183
184<
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
260
261
262
263
Murban Treated 205
206
207
208
209
1
1
1
2
2
2
3
3
3
4
4
4
5
5
5
6
6
6
7
7 "
7
7
8
8
8
8
9
9
9
9
10
10
10
10
Center
11
11
"
1
1
1
1
1
4:25
11
n
4:27
11
11
4:31
11
11
4:36
11
11
4:40
"
"
4:41
"
11
4:54
11
n
n
4:55
11
"
11
4:58
11
"
11
5:00
n
n
ii
6:42
n
n
11
3:56
n
n
n
n
0.16
0.05
0.07
0.05
0.06
0.05
0.05
0.06
0.07
0.06
0.09
0.09
0.12
0.09
0.06
0.05
0.06
0.05
0.06
0.05
0.10
0.09
31.2
0.11
0.05
0.04
0.05
0.05
0.10
0.05
0.06
0.06
0.04
0.04
0.04
0.07
0.09
0.04
0.03
0.07
0.05
0.06
0.05
46
-------
Crude Condition Sample Station
Extractable Organics
Time After in Water (mg/1)
Spill Om 1m 3m 6m 9m
Murban Treated 210
211
212
;. 213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
2 4:00
2
2
2
2
3 4:09
3
3
3
3
4 4:16
4 »
4
4 "
4
5 4:25
5
5
5
5
6 4:29
6
6
6
6
7 4:35
7
7
7 "
7
8 4:37
8
8
8
8
O II
Q II
8
8
8
9 4:40
9
9
0.97
0.07
0.07
0.06
0.04
0.30
0.06
0.06
0.06
0.05
0.23
0.10
0.05
0.05
0.05
0.59
0.23
0.18
0.06
0.06
0.51
0.35
0.28
0.07
0.06
0.21
0.15
0.11
0.10
0.07
0.25
0.15
0.12
0.06
0.07
0.15
0.08
0.07
0.05
0.07
0.25
0.10
0.15
47
-------
Crude Condition Sample
Murban Treated 253
254
255
256
257
258
259
264
265
266
267
268
La Rosa Not Treated 439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
Station
9
9
10
10
10
10
10
Center
ti
ii
H
ii
1
1
1
1
2
2 "
2
2
3
3
3
3
4
4
4
4
5
5
5
5
6
6
6
6
7
7
7
7
8
8
Time After
Spill
4:40
ii
4:45
.I H
n
i'
ii
n
5:42
n
n
n
n
6:21
M
ii
n
6:24
n
n
n
6:29
n
n
n
6:31
n
n
n
6:33
n
n
n
6:36
n
n
n
6:49
n
n
n
6:52
n
Extractable Organics
in Water (mg/1)
Om 1m 3m 6m
0.05
0
0.17
0.10
0.07
0.07
0
0.20
0.14
0.08
0.22 '
.0
0.08
0.12
0.07
0
0.12
0.07
0.08
0
0.09
0.09
0.06
0
0.06
0.08
0.07
0
0.11
0.12
0.06
0
0.06
0.15
0.06
0
0.11
0.07
0.04
0
0.07
0.07
9m
.06
.05
.06
.08
.05
.07
.05
.05
.05
.05
48
-------
Crude Condition Sample
La Rosa Not Treated 469
470
471
472
473
474
475
476
477
478
530
531
532
533
La Rosa Treated 479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
Station
8
8
9
9
9
9
10
10
10
10
Center
"
11
"
1*
1
1
1
1
2*
2
2
2
2
3*
3
3
3
3
4*
4
4
4
4
5*
5
5
5
5
6*
6
6
Extractable Organics
Time After in Water (mg/1)
Spill Om 1m 3m 6m
6:52 0.07
11
6:55 0.07
0.07
0.07
11
6:58 0.05
0.06
0.05
n
8:35 0.09
0.10
0.08
11
4:33 4.15
0.17
0.08
0.07
11
4:43 1.8
1.1
0.22
0.09
11
4:50 0.31
0.27
0.16
0.07
11
4:59 0.24
0.06
0.10
0.06
11
5:07 0.26
0.07
0.06
0.05
»
5:10 0.21
0.39
0.07
9m
0.05
0.06
0.03
0.06
0.07
0.06
0.08
0.07
0.05
49
-------
Crude Condition Sample Station
Extractable Organics
Time After in Water (mg/1)
Spill Om 1m 3m 6m 9m
La Rosa Treated 507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
525
526
527
528
529
538
534
535
536
537
6 5:10
6
7* 5:13
7
7
7
7
8* 5:15
8
8
8
8
9* 5:18
9
9
9
9
10* 5:20
10 "
10
10
10
Center 6:23
ii n
n it
ti n
n ii
0.06
0.06
0.14
0.05
0.09
0.06
0.05
0.55
0.46
0.34
0.14
0.11
0.09
0.47
0.46
0.36
0.08
0.53
0.48
0.18
0.19
0.05
0.21
0.12
0.06
0.06
0.05
*A11 10 stations in this series were on a single transect through the long
dimension of the slick (parallel to the wind).
50
-------
APPENDIX B
DATA FROM CHEVRON OIL FIELD RESEARCH CO.
ClMvron
Chevron Oil Field Research Company
A Stmtard Oil Compny of CMom* Subedtary
P.O. Box 446, La Habra, CA 90631, U.S.A.
November 3, 1980
Mr. Jaret C. Johnson
JBF Scientific Corporation
2 Jewel Drive
Wilmington, MA 01887
Dear Jay:
Enclosed are four tables that summarize the Ci to C10 volatile
hydrocarbons measured in samples collected during the 1979
East Coast research oil spills.
Table 1 shows the background concentrations (pg/L, ppb)
measured in samples prior to the oil discharges. These very
low concentrations of aromatic hydrocarbons may be in seawater,
or from the pumping system (polypropylene tubing) , seals on
bottles or laboratory contamination. In any event, they are
quite low. Only 12 of the samples analyzed (Tables 1 and 3)
show concentrations of Ci to C10 hydrocarbons that are
higher than background (background has not been subtracted).
None of these samples contained very high concentrations of
dispersed oil as shown by the values at the bottom of Table 1.
It is unfortunate that samples were not collected during the
first sample run following dispersant treatment when dispersed
oil ranged up to 7 mg/L (ppm) .
Table 2 presents the concentrations in Mg/L (ppb) for three
water samples (of 44 analyzed, Tables 2 and 4) that contained
Ct to CIQ hydrocarbons that exceeded background concentrations.
These samples were collected from the research vessel Cape
Henlopen used for the biology program. A copy of these
results are being sent to the Biological Contractor at the
University of Southern California.
Sincerely,
Attach: Tables 1-4
Clayton D. McAuliffe
cc w/attach:
M. Oguri, University of Southern California
6. P. Canevari, Exxon Research & Engineering
J. R. Gould, American Petroleum Institute
51
-------
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52
-------
TABLE B-2; LOW-MOLECULAR-WEIGHT HYDROCARBONS FOUND IN WATER SAMPLES
COLLECTED FROM BIOLOGY SHIP FROM UNDER MURBAN CRUDE
OIL SLICKS, OCTOBER 22, 1979
Oil M-UT3 M-UT M-UT
Sample station B2.5 BB2.5-3 BB2.5-3
Sample number B5 B7 B8
Depth, m ;, 3, 1 1
Time 0^35 0950 0950
Hydrocarbons, |Jg/L
(ppb)
Methane .65 .084 .091
Ethane
Propane .035 .004
Isobutane .015
n-Butane .029
Isopentane .019
n-Pentane .027
Cyclopentane .Oil
3-Methylpentane . 00_4
n-Hexane
Methylcyclopentane
Benzene .062 .045 .050
Cyclohexane .006 .005
n-Heptane
Methylcyclohexane
Toluene .31 .31 .46
Ethylbenzene .110 .117 .13
m, p-Xylene .35 .38 .42
o-Xylene .18 .20 .26
926 Trimethylbenzene .038 .025
1027 Trimethylbenzene .121 .076 .106
1077 Trimethylbenzene .031 .021 .046
1,2,4-Trimethylbenzene .118 .084 .14
1197 Trimethylbenzene .050 .050
Total 2.17 1.32 1.78
aM-UT, Untreated Murban crude oil
53
-------
TABLE B-3. LIST OF SAMPLES ANALYZED FOR LOW-MOLECULAR-WEIGHT
HYDROCARBONS THAT CONTAINED ONLY BACKGROUND CONCENTRATIONS
(See Table B-l for Background Concentrations)
Sample Sample Sample Collection Crude Oil Sample
Number Station Depth,m Time Slick Run Number
1017 8% 1 0946
1019 " 3 " Untreated Murban 1st
1020 " 6
1021 " 9
1023 12% 1 1123 Treated Murban 1st
1024 "3 " " " "
1030 14% : 3 1130 " " ,,
1039 22% 0 1212 Treated Murban 2nd
1041 " 1
1043 " 3
1047 24% 3 1220
1048 " 6
1049 " 9 "
1051 28% 1 1239
1053 " 3 " " "
1056 32% 1 1316 Untreated Murban 2nd
1059 34% 1 1325 "
1066 42% 1 1420 Treated Murban 3rd
1067 " 3
1070 44% 1 1438 " "
1071 " 3 "- "
1074 48% 1 1458
1075 " 3 1458
1085 2% 1 0916 Untreated La Rosa 1st
1086 " 3 " " "
1095 12% 3 1313 Treated La Rosa " 1st
1096 " 6 "
1097 " 9 " " "
1101 22% 3 1404 Treated La Rosa 2nd
1102 " 6
1103 " 9 " " "
1104 28% 1 1439 " "
1105 " 3
1106 " 6
1107 " 9 " " "
1108 32% 1 1511 Untreated La Rosa 2nd
1109 " 3 " " "
1110 " 6
1111 " 9
1112 38% 1 1538
1113 " 3 n - ..
1114 42% 0 1610 Treated La Rosa 3rd
1115 " 1
1117 " 3 " " "
1118 " 6
1119 » 9
54
-------
TABLE B-4. LIST OF SAMPLES ANALYZED FOR LOW-MOLECULAR-WEIGHT
HYDROCARBONS THAT CONTAINED ONLY BACKGROUND CONCENTRATIONS
(See Table B-l for Background Concentrations)
Sample
Number
B4
B7
B9
Bll
B17
B18
B19
B20
B22
B24
B25
B26
B27
B29
B30
B31
B36
B37
B38
B39
B40
B41
B43
B46
B50
B51
B53
B54
B55
B56
B57
B58
B59
B60
B65
B63
B64
B66
B67
B68
B69
Sampler
Niskin
Pump
ii
Niskin
Niskin
it
it
Pump
Niskin
Niskin
Niskin
Niskin
Niskin
tt
Pump
Niskin
Niskin
Niskin
Pump
Pump
Niskin
Niskin
Niskin
Niskin
Station
Number
BB4V3
BB4^-li
86=5
Sample
Depth,m
1
1
3
1
1
3
6
1
3
1
3
6
1
1
3
6
1
3
1
3
6.
1
3
1
1
3
1
3
6
1
1
3
3
1
3
6
1
1
3
6
1
Collection
Time
0935
0950
0950
1042
1129
1136
1305
1416
1412
0807
it
0924
it
0935
it
1018
1042
it
1412
it
1344
it
1344
ff
1500
ti
1515
1611
it
1646
Crude Oil
Slick
Untreated Murban
Open water (control)
Treated Murban
Treated Murban
it
Treated Murban
Open water (control)
Treated Murban
Open water (control)
Untreated La Rosa
n
it
Untreated La Rosa
it
Open water (control)
Untreated La Rosa
It --:l
Treated La Rosa
it
Treated La Rosa
Treated La Rosa
Treated La Rosa
ti
H
Open water (control)
Treated La Rosa
Untreated La Rosa
55
-------
TECHNICAL REPORT DATA
ff lease' read Instructions on the reverse before completing!
1. REPORT NO.
TITLE AND SUBTITLE
RESPONSE OF CRUDE OIL SLICKS TO
DISPERSANT TREATMENT AT SEA
6, PERFORMING ORGANIZATION CODE
3. RECIPIENT'S ACCESSI ON> NO.
5. REPORT DATE
7. AUTHOR(S)
JBF Scientific Corporation
8. PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
JBF Scientific Corporation
Wilmington, MA 01887
10. PROGRAM ELEMENT NO.
CBR1DA
11. CONTRACT/GRANT NO.
R-806056
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research LaboratoryGin., OH
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
13.
VERED
14. SPONSORING AGENCY CODE
EPA/600/14
15. SUPPLEMENTARY NOTES
Project Officer: Leo T.
Me Carthy (201) 321-6630
16. ABSTRACT
>*j i n/^Vji i - O
Four small research oil spills (3.54 m-3 each) were made to compare the physical and
chemical behavior of crude oils on the sea with and without dispersant treatment. Work
was performed 90 km southeast of New York Harbor under a research ocean dumping permit
from the U.S. Environmental Protection Agency (EPA). Each spill was made from a
research vessel and was tracked by vessel and aircraft for several hr. Two crude oils
were used; one spill of each was treated with dispersant after 30 min, and one was
allowed to weather naturally as an experimental control. A self-mix dispersant was
sprayed on the two treated slicks from a helicopter that had been fitted with a spray
system delivering droplets whose mean diameter was approximately 2 mm. More than 750
samples of background water, water under the slicks, and surface water were taken for
chemical analysis. Sampling continued for 6 to 7 hr after each spill. Aerial
photographs were taken, and representative photographs are presented in this report.
Currents and winds were measured, leading to interpretation of physical transport of
the oils. This report complements earlier work performed in 1975 and 1978.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport)
UNCLASSIFIED
21. NO. OF PAGES
20. SECURITY CLASS (This page)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
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