DEVELOPMENT OF COREXIT 9580— A CHEMICAL BEACH CLEANER Robert J. Fiocco, Gerard P. Canevari, John B. Wilkinson Exxon Research and Engineering Company P.O. Box 101 Florham Park, New Jersey 07932

Jan Bock and Max Robbins Exxon Research and Engineering Company Route 22 East Annandale, New Jersey 08801

Hans O. Jahns Exxon Production Research Company 3120 Buffalo Speedway Houston, Texas 77001

Ralph K. Markarian Exxon Biomedicai Sciences, Inc. Mettlers Road East Millstone, New Jersey 08873

including toxicologists, microbiologists, chemists, and engineers. By midsummer, two significant technical options for enhanced shoreline cleanup were identified. One was the development of a new shoreline cleaning formulation called Corexit 9580, which is the subject of this paper. The other technology, enhanced bioremediation, is discussed in another paper.

ABSTRACT: Chemical beach cleaners can facilitate cleanups of oiled shorelines by improving the efficiency of washing with water. The improvement is a result of reduced adhesion of the oil coating, which makes it easier to remove from shoreline surfaces, thereby reducing washing time and lowering the temperature of the wash water needed to clean a given area. The criteria established for use of chemical beach cleaners in the Exxon Valdez spill cleanup included demonstrating enhanced cleaning with low levels of toxicity to marine biota and with minimal oil dispersion. Since no commercially available products satisfactorily met these criteria for use in Alaska, a new product, Corexit 9580, was specifically developed in response to this need. This paper describes the successful development of this chemical, including both laboratory testing and field testing in Prince William Sound.

Logistics of shoreline cleanup Cleanup personnel and the task force were chasing a moving target, particularly in early summer. Crude oil weathers over time and becomes more difficult to remove from the shoreline as it interacts with the environment. There are dramatic shifts as crude weathers; in particular, the lighter components evaporate. In addition, photooxidation and biological degradation take place at the surfaces and in the sediment. Also, subsurface oil weathers differently from surface oil. Thus, the oil's chemical and physical properties were changing, to the point that methods identified early in the spill might not work as well several months later. Chemical cleaners could be easily integrated into the shoreline cleanup operation. The typical operation involved water washing the beach and flushing the oil into a boomed water zone to allow oil recovery. A chemical presoak could be applied to the beach prior to water washing, and/or chemicals could be added to the wash water to make it more effective for oil removal. The following criteria were developed for this chemically enhanced cleanup operation. The chemical beach cleaner must have low toxicity and enhance the removal of weathered oil from rocks. To obtain state and federal approval, it also had to allow recovery of the oil rather than disperse the oil into the water column. Finally, before applying it in the field, it had to be listed on the U.S. Environmental Protection Agency's (EPA) National Contingency Plan Product Schedule.

Approaches to cleaning oiled shorelines are quite varied. The appropriate choice depends on the specific situation. Influencing factors include type of shoreline, type of oil, the impacts of equipment traffic on the shoreline, and biological sensitivity. The cleanup of oiled shorelines traditionally has involved mechanical and labor-intensive methods. The use of chemical agents to help remove oil more efficiently has been limited. Historically, this approach has been suspect since the Torrey Canyon Spill in 1967, when toxic chemical detergents were used to clean the shoreline, with predictable mortality of the shoreline biota. Unfortunately, the memory of this impact has lasted, and many still believe that "chemicals" are inherently toxic, despite dramatic advances in the development of products with very low toxicity. In 1970, after the Delian Appollon spill in Tampa Bay, a low-toxicity chemical treatment was used extensively in the cleanup. The treatment was designed to remove oil from the shoreline and disperse it back to sea, where biodegradation could eliminate it from the environment. An extensive sampling of the marine life in the cleanup area during and after the chemical cleanup demonstrated that there were no toxic effects.2 Soon after the Exxon Valdez grounding in March 1989, a technology task force was established by Exxon to provide enhanced cleanup options. Its activity was directed at shoreline cleanup, and specifically to chemical, sorbent, or bioremediation techniques. It was felt that enhanced shoreline cleanup technology would be a valuable complement to the more mechanical means being considered at the time in Alaska. The task force included professionals with oil spill research and development experience and a combination of technical disciplines,

Laboratory screening studies To find chemicals that met these criteria, a chemical cleaner evaluating capability was established. One tool for evaluating chemicals was a laboratory beach washing apparatus. In brief, beaker-sized "beaches" were put together with small aquarium rocks. The rocks were oiled with artificially weathered Alaska North Slope (ANS) crude and then refrigerated to 5° C. Finally, they were treated with a fixed quantity of

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chemical cleaner and then washed using standardized procedures. The washings were collected and evaluated to determine the cleaning effectiveness and dispersion characteristics of the candidate chemical. The oil application rate used in these experiments corresponded to a shoreline oiling of 2.5 gallons per 100 square feet. The beach cleaner presoak application rate corresponded to 1.0 gallon per 100 square feet, and the seawater flush rate corresponded to 1 gallon per square foot. These rates were chosen to correspond with anticipated rates in the field. Overall, the test was aimed principally at ranking chemical agents in terms of cleaning effectiveness and degree of dispersion. Representative results from the laboratory evaluation are shown in Figure 1. The percentage dispersion of the oil after washing is plotted against the amount of oil removed. As can be seen from the points, few of the chemicals combine low dispersion and good cleaning ability (shown by positions in the lower right-hand corner of the plot). The figure notes the performance of the new Corexit 9580 beach cleaner. This cleaner is especially effective at reducing the adhesion of the oil coating and allowing water to more easily displace the oil. The beach cleaner is a balanced formulation of selected biodegradable surfactants in a low-toxicity, highly refined hydrocarbon solvent system. As shown in Figure 1, Corexit 9580 was among the highest in oil removal (26 percent) and among the lowest in oil dispersion (7 percent at 1 minute settling time). Control tests with no chemical agents gave essentially no oil removal. Some products were a bit better on the cleaning side but exhibited higher dispersion and much greater toxicity to fish. A few products showed slightly less dispersion, but were not as effective in cleaning and, more importantly, were not listed on the EPA National Contingency Plan (NCP) Product Schedule. Based on toxicity data in the NCP, Corexit 9580 was one of the least toxic products available. In all, a very large number of chemicals were evaluated, including 44 commercially available products, most of which were not Exxon products. Twelve of these chemicals were tested on artificial pilot-scale beaches (10 feet by 10 feet) in New Jersey and Texas; eight were evaluated in actual field tests in Prince William Sound.

• July 1989—Small-scale comparative field test at Eleanor Island; large-scale test of Corexit 9580 at Disk Island • August 1989—Large-scale test of Corexit 9580 at Smith Island; limited operation test at Smith Island • June 1990—First demonstration of Corexit 9580 at Knight Island • July 1990—Second demonstration of Corexit 9580 at Knight Island While initial formulations of Corexit 9580 were being developed, field testing started in Alaska with an existing low-toxicity product, Corexit 7664, which was found effective for the Delian Appollon spill cleanup. This field test was carried out in mid-May, since it was important to get out to the field quickly, to calibrate the laboratory and field test procedures. A 4-percent solution of the material in water was applied as a presoak and also educted into the wash water. The product, which is a water-based cleaner, was not effective on the weathered surface coating of oil on the Ingot Island shoreline. In early June, a screening experiment was carried out at Knight Island. Fourteen 10-foot-by-10-foot plots on a section of shoreline were set up to test a matrix of seven products that had looked promising in the screening studies. One of the products was an early version of Corexit 9580. The plots were typically treated with hydrocarbon-based clean as a presoak, then washed with water after one hour, with or without water-based cleaner added to the wash water. Follow-up field tests were carried out in late June at Knight Island and in early July at Eleanor Island, to further define the best beach cleaner formulation and application procedure. These initial field tests demonstrated that Corexit 9580, applied as a presoak 15 to 30 minutes prior to water washing, was clearly the most promising shoreline cleaner as judged by effectiveness, dispersion, and toxicity criteria. Addition of chemical cleaning agents to the wash water did not appear worthwhile. The next step was to conduct a fullscale field test with Corexit 9580 beach cleaner.

Initial 1989 field tests

A side-by-side test was performed at Disk Island to demonstrate the effectiveness and environmental safety aspects of Corexit 9580 use under field conditions. Water quality and effectiveness data were obtained from a beach site (the reference beach) washed in the standard way and from a neighboring beach site washed with the use of Corexit 9580. The reference beach was cleaned on July 17, during both incoming and receding tides. The Corexit beach was cleaned one week later, on July 24, to avoid cross-contamination and permit extensive sampling. Cleaning was done on an incoming tide.

The chronology of the shoreline cleaner development and testing can be summarized as follows: • April 1989—Laboratory and pilot-scale studies initiated • May 1989—Large-scale field test of Corexit 7664 at Ingot Island • June 1989—Multichemical field test at Knight Island; large-scale field test of BP1100X at Knight Island

Full-scale field testing of Corexit 9580

Oil Removed, % Figure 1. Laboratory screening results for oil dispersion and effectiveness of Corexit 9580 and other candidate chemical beach cleaners

DISPERSANTS Data obtained at Disk Island are shown in Table I. As part of the test at both beach sites, three water sampling stations were set up in the area just outside the booms. One, T-2, was a fixed station; R-l and R-2 were roving stations based on water current direction. At each station, samples were taken at the surface and at 1-meter and 3-meter depths. Data are shown for pretest conditions, as well as maximum and average values during washing, and one and three days after the tests. Total petroleum hydrocarbon (TPH) readings are low and comparable at the two sites. Other readings, just offshore within the primary boom, showed slightly higher values, with a maximum around 22 ppm at the Corexit beach, for a few hours at the beginning of the test. Data on the oil content in the surface and subsurface sediment from the reference and test beaches were also obtained. The samples were taken before and after the beaches were washed, at eight sampling stations in the middle and upper intertidal zones. High variability in the TPH of the pretest samples, ranging from 165 to 32,500 ppm, was noted. On average, however, the data indicated that the Corexit beach was cleaned to a greater extent, (65 percent surface oil removal compared with 61 percent for the reference, and 67 percent subsurface oil removal compared with 27 percent for the reference), even though only half as much time was used to wash this site. Bioassay studies were also carried out as part of the Disk Island test. These included "live box" tests at the sites, as well as the laboratory tests with in-situ runoff water collected just offshore, inside the primary boom, during the early stage of the Corexit test when the highest oil levels occurred. As shown in Table 2, data from the runoff water tests showed no significant toxic effects attributable to the beach cleaner. The live box fish studies were inconclusive, due to mortality attributed to stress and handling of the fish prior to the test. Acute toxicity data were also obtained on a number of organisms to confirm the low toxicity of Corexit 9580 (Table 2). The tests covered the effect of Corexit 9580 alone in seawater and combined with weathered Alaska North Slope crude oil. These 48- and 96-hour LC50 values are generally orders of magnitude higher than the oil contents measured during the field tests.

Operational testing of Corexit 9580 While awaiting some of the field test analyses, researchers began a large-scale field test on Smith Island in early August. This test provided an opportunity for operations personnel to gain field experience and

397

Table 2. Results of acute bioassay studies of Corexit 9580 Corexit 9580 in seawater Mysid shrimp, acute 96-hour LC50: 29-279 ppm! Brine shrimp, acute 48-hour LC50: 2,800 ppm King salmon, acute 48-hour LC50: 3,750 ppm Mummichog, acute 96-hour LC50: 96,500 ppm Oyster larvae, acute 48-hour LC50: 54 ppm Corexit 9580 and weathered Alaska North Slope crude in seawater Mysid shrimp, acute 96-hour LC^: 39-41 ppm (1:10 Corexit:oil) King Salmon, acute 48-hour LC50: 1,650 ppm (1:10 Corexit:oil) Oyster larvae, acute 48-hour LC50: 2,928 ppm (1:30 Corexit:oil) Runoff water from Disk Island field test of Corexit 9580 No significant effects were observed during 96-hour acute exposure to 100 percent in-situ water for mysid shrimp, microalgae, and oyster larvae. 1. Result is method-dependent develop expertise on the use of Corexit 9580 shoreline cleaner. A joint monitoring effect was established with the Shoreline R&D Committee, which included personnel of the Alaska Department of Environmental Conservation (ADEC), the National Oceanic & Atmospheric Agency (NOAA), the U.S. Coast Guard (USCG), and EPA. Efficiency was over four times better on average when Corexit 9580 was used (1,913 square feet of beach cleaned per hour, compared with 439 square feet for standard water washing). This was a key measure of performance in view of the limited time to complete the 1989 cleanup program. Exxon sought approval from the Regional Response Team (RRT) and the federal on-scene coordinate (FOSC) for wide-scale use of Corexit 9580 as early as possible, to gain maximum advantage from the increased efficiency it provided. It was anticipated that interim approval for use in Prince William Sound could be obtained by midAugust, based primarily on the available toxicity and water quality data from Disk Island. These data, as well as data from Smith Island, showed no significant added environmentalriskassociated with the use of Corexit 9580, compared with the standard water washing procedure. However, interim approval for wide-scale use of the beach cleaner was not received by mid-August. It was the review committee's view that increased operational effectiveness with the use of Corexit 9580

Table 1. Disk Island water quality outside booms Total petroleum hydrocarbons (ppm)j Sample depth and time Surface Before During (average) During (maximum) After one day After three days 1 meter Before During (average) During (maximum) After one day After three days 3 meters Before During (average) During (maximum) After one day After three days

Reference beach sampling stations

Corexit beach sampling stations

T-2

ÊΛ

R-2

T-2

R-l

R-2

0.26 0.55 2.20 0.28 0.20

0.20 0.88 2.20 0.22 0.26

3.00 0.25 0.39 0.20 0.96

0.20 0.56 2.30 0.83 0.20

0.20 0.83 3.50 0.58 0.57

0.20 0.68 2.30 0.61 NA

0.20 0.25 0.40 0.20 0.20

0.20 0.23 0.37 0.20 0.20

0.27 0.33 0.49 0.20 0.29

0.20 0.28 0.54 0.44 0.20

0.23 0.48 1.70 0.21 0.26

0.23 0.37 0.64 0.44 NA

0.20 0.31 0.52 0.32 0.20

NA 0.20 0.20 0.20 0.40

NA 0.20 0.20 0.26 0.20

0.20 0.34 0.65 0.42 0.20

0.20 0.26 0.33 NA NA

NA 0.23 0.26 NA NA

1. The minimum reporting limit for total petroleum hydrocarbon (TPH) was 0.2 ppm for these analyses. For conservatism, 0.20 is reported and used in calculating averages, even though content was below this limit.

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had not been well enough documented at that time to justify the additional environmental risk associated with its use on the shoreline. Issues included the amount of oil recovered at various sites, the adequacy of toxicity data, and the capability to transfer the technology to operational use. A majority of the committee felt that the data were sufficient to develop adequate guidelines to protect the environment if interim approval were granted for areawide use. To avoid further delays and a possible deadlock, Exxon requested approval of a limited, phased implementation of operational use of Corexit 9580. After the extended review of the data, and in response to Exxon's request, approval for a limited operational "test" on Smith Island was granted in late August. This test was limited initially to a single crew and could be expanded only with RRT approval. Poor weather and the high-energy nature of the sites hampered the test and made oil containment and recovery more difficult, but operations personnel successfully adapted the technology to overcome these difficulties. The beach cleaner was effectively used at a reduced application rate of one-half gallon per 100 square feet, and sorbent boom was used more extensively to contain and recover oil. Field testing continued until September 6, when cleaning of Smith Island was essentially complete. The beaches were then bioremediated as a final treatment step. While approval for general use of the beach cleaner was not received at this time, the FOSC did not rule out the possible use of Corexit 9580 or other beach cleaning agents in 1990.

Winter research program Laboratory studies on shoreline cleaning continued through the winter of 1989-1990. This program was aimed primarily at assessing the impact of additional crude oil weathering on the physical and chemical cleaning procedures that might be used during the 1990 summer cleanup effort. In addition, followup studies were carried out on alternative or improved beach cleaning agents, oil recovery of treated oil, and characterization of a tan suspension (plume) observed during cleaning in 1989. Figure 2 illustrates laboratory data generated on the impact of additional weathering on cleaning effectiveness. The laboratory beach washing apparatus described earlier was used in these tests. This time a laboratory apparatus (weatherometer) was also used to accelerate weathering of the oiled rocks before cleaning. The data show that additional weathering made oil removal more difficult, even with wash

water at 160° F at a flush volume of 2.5 gallons per square foot of area. On the other hand, the use of Corexit 9580 as a presoak gave significantly higher cleaning effectiveness, even with lower water temperature (110° F) and flushing volume (1 gallon per square foot). Laboratory testing of alternative chemical products continued. No chemical cleaning product tested equaled or surpassed Corexit 9580 in the combined properties of good surface cleaning, low dispersion, and low toxicity. The laboratory tests also confirmed field observations that the presence of Corexit 9580 in oil to be recovered would not adversely affect recoverability with sorbents. Laboratory studies were also carried out to characterize a tancolored suspension observed in field trials. Field samples taken directly from a plume during one of the Smith Island tests in August had indicated that this suspension contained only 3 to 6 ppm oil. Laboratory analyses showed that the suspension was composed mainly of 1 to 10-micron inorganic silt and clay particles derived from natural environmental sources.

Independent testing of beach cleaner performance During the winter, independent test data from Environment Canada that became available confirmed the performance of Corexit 9580.3 These tests showed Corexit 9580 to be clearly superior to 20 other products evaluated. The laboratory test procedure involved the washing of bunker C oil from a stainless steel trough. Corexit 9580 showed the highest effectiveness in removing oil, whether fresh water or salt water was used for a rinse. In dispersion tests, Corexit 9580 had the lowest tendency (0 percent) to disperse oil. The products were also tested for aquatic toxicity using standard rainbow trout 96-hour exposure tests. Corexit was found to be the least toxic (LC50 of over 5,600 mg/L), and in a category that could be considered practically nontoxic. Environment Canada concluded that only one agent, Corexit 9580, showed significant effectiveness and low aquatic toxicity.

1990 work plan Exxon developed plans for the 1990 cleanup program in cooperation with state and federal agencies. As part of the 1990 work plan, spot-

OIL REMOVAL, %

Figure 2. Results of laboratory tests of the effects of oil weathering on the effectiveness of Corexit 9580, compared with water washing

DISPERSANTS washing of heavily coated rock faces and large boulders was called for at about 90 sites. Hot water pressure water units are typically used for this task; these units spray jets of water heated to 160° F or higher, at a flow rate of about five gallons per minute. Alternatively, Exxon proposed to apply Corexit 9580 as a presoak and then wash with water at a significantly reduced temperature, such as 110° F. This approach, which was developed on the basis of the laboratory tests over the winter, aimed to make the spot-washing operation more effective, safer for the workers, and environmentally sound. Oil recovery during spot-washing was to be accomplished by sorbent materials such as snare boom and pads positioned around the areas being cleaned. This technique differs from that practiced during 1989, mainly in that containment booms are not required in the water because of the much smaller amounts of oil being removed. Additionally, since spot-washing would usually be done on a rising tide, any Corexit 9580-treated oil falling onto the surrounding area and not initially captured by the sorbent would tend to be released and float on the incoming tide. The oil would then be recovered by snare boom left at the site for a few tide changes. As a final step, the surrounding area was to be bioremediated to complete the cleanup and oil recovery. On June 8, 1990, in response to Exxon's proposal, the FOSC gave approval to demonstrate at up to five sites that the use of Corexit 9580 improved cleaning at lower wash water temperatures than normal spotwashing operations, without adversely affecting oil recovery. The FOSC's approval letter indicated that efficiency was to be determined visually, and no sophisticated sampling programs were required. Many of the 90 beach segments where spot-washing was called for in the 1990 work plan had already been treated at the time approval for demonstrations were received. Hot water spot-washing was generally found to give disappointing results; therefore, extensive manual scraping of heavily coated rock surfaces and boulders had been carried out at many of these segments.

First 1990 demonstration The site of the first demonstration (Knight Island segment KN136 at the Bay of Isles) was selected in cooperation with representatives from the USCG, ADEC, EPA, and NOAA. The demonstration involved spot-washing a weathered oil-coated rock face, about 14 feet long by 5 feet high. One half of the rock face served as a reference area, to be spot-washed in the normal way with hot water only. The other half was to be pretreated with Corexit 9580 and then washed with water at a significantly lower temperature. The 7-foot-by-5-foot reference area was spot-washed with very hot water (up to about 175° F at the discharge nozzle) for 10 minutes, with the operator stopping when it appeared that oily matter was no longer being removed. Corexit 9580 was then applied to the other half of the rock face, using a small motorized sprayer typically used for gardening. After allowing about 15 minutes for presoaking, the face was spotwashed for 6 minutes. The water temperature was about 40° F lower than that used for the reference area. At the conclusion of the demonstration, the sorbent pads at the base

of the Corexit 9580-treated rock face were visibly more oily than those at the base of the untreated reference face. As the surface dried, the Corexit 9580-treated rock face clearly looked cleaner, while a visible oily coating remained on much of the reference face. Observers generally agreed that the treated surface was cleaner. A bed of mussels and barnacles at the base of the rock face on the Corexit 9580 side appeared healthy after the treatment. The demonstration was monitored by a field industrial hygienist, who found no health concerns.

Second 1990 demonstration A second demonstration at Knight Island (segment KN 113 at Herring Bay) was carried out in mid-July. The area selected for the demo was a heavily tarred rock face wall about 50 feet long, with a zone of tarred angular boulders at the upper intertidal end. The wall was marked off into five areas, three areas for Corexit 9580 treatment and two reference areas for normal hot water spot-washing. The weather on the day of the demonstration was poor, with a steady rain during most of the day. The reference areas were washed with hot (160° F) water. At the Corexit areas, beach cleaner was applied at a nominal rate of 1 gallon per 100 square feet. At the end of the demo, the sorbent pads and snare boom surrounding the base of the rock wall and boulders were heavily stained with oil, indicating good recovery. Significantly cleaner surfaces were produced with Corexit 9580 treatment than with hot water washing only. Approximately 150 square feet of surface were cleaned during the second demonstration, using about l3/s gallons of beach cleaner. The wash rate averaged 5.8 square feet per minute typical hot water washing averaged about half this rate (3.2 square feet per minute). A summary of data from the two demonstrations is given in Table 3. The demonstration was again monitored by an industrial hygienist. Airborne hydrocarbon content was measured around the work area and found to be minimal and well below the recommended 300-ppm 8-hour exposure level. During the three-minute beach cleaner application time, a peak value of 12 ppm was noted. During the 100° F water wash, the peak value was 17 ppm; during the 160° F water wash, the peak was 8 ppm. The concentration went to zero at the end of the demonstration. Based on the two successful demonstrations, Exxon requested general approval for operational use of Corexit 9580 in connection with the spot-washing technique. ADEC, however, did not accede to Exxon's request. It stated that, "While solvent action did enhance oil removal efficiency, hot water alone also proved to be effective. Recovery methods used with COREXIT failed to prove to be more effective than with hot water alone."1 In Exxon's view, these arguments were inconsistent with the bases originally agreed upon for approving wide-scale use of the beach cleaner. As indirectly stated by ADEC, the bases agreed upon for approval had been demonstrated; that is, Corexit 9580 enhanced oil removal efficiency, even at lower wash water temperature, and recovery of oil was at least as effective as with hot water alone. In view of the state's position and the advanced stage of the cleanup, no further demonstrations were requested or conducted.

Table 3. Summary of 1990 Corexit 9580 demonstrations

Site

Estimated area (ft2)

Corexit 9580 spot-washing KN 136 35 KN 113 150 Total 185 Hot water spot-washing KN 136 35 KN 113 71 Total 106

399

Wash time (mins)

Corexit 9580 applied (gal)

Wash rate (ft2/min)

6 26 32

3/8 P/8 V/A

6.9 5.8 5.8

135 110

10 23 33

0 0 0

3.5 3.1 3.2

175 160

Temperature (°F)

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Conclusion

References

Exxon conducted an extensive, accelerated, and environmentally sensitive program in chemically enhanced shoreline cleanup. A new chemical beach cleaner, Corexit 9580, was developed and demonstrated by mid-summer 1989 for standard water-wash operations. The cleaner continued to perform well in field trials during 1989. In 1990, two field demonstrations showed that the beach cleaner would significantly enhance the effectiveness of spot-washing operations, without adversely affecting either recovery operations or the environment. While approval for general operational use of Corexit 9580 in Prince William Sound was not received, the technology remains a viable option for future cleanups.

1. Bayliss, Randolph, 1990. Communication from State Representatives, Alaska Regional Response Team, to Capt. D. E. Bodron, Cochair, Regional Response Team, July 18, 1990 2. Canevari, Gerard P., 1979. The restoration of oiled shorelines by the proper use of chemical dispersants. Proceedings of the 1979 Oil Spill Conference. American Petroleum Institute, Washington, D.C., pp443-446 3. Fingas, Mervin F., Gordon Stoodley, Gary Harris, and Ariane Hsia, 1989. Evaluation of chemical beach cleaners. Paper presented at Cleanup Technology Workshop, Anchorage, Alaska, November 28-30