United States
Environmental Protection
Agency
Office of Research
and Development
Washington, DC 20460
EPA/600/8-89/073
August
1989
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ALASKAN OIL SPILL BIOREMEDIATION PROJECT
A
few minutes after midnight on March 24,
1989, the 987-foot tanker Exxon Valdez ran
aground on Bligh Reef in Prince William
Sound, Alaska. Approximately 11 million
gallons of crude oil flooded one of the na-
tion's most pristine and sensitive environments in less
than 5 hours. As part of the effort to clean up the spill,
the U.S. Environmental Protection Agency's Office of
Research and Development initiated a "bioremediation"
study to determine the feasibility of using nutrients to
enhance microorganisms to degrade oil on the shore-
lines of Prince William Sound. A major portion of this
venture was supported financially by the Exxon Com-
pany. The study demonstrates that bioremediation is a
powerful tool for reducing the detrimental effects of
crude oil and other chemical spills. As a result, this
innovative technology holds great promise for more
timely and effective cleanup of future oil spills, and
marks a significant step forward in oil spill research and
remediation.
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Energy and the Environment
Americans use about 700 million gal-
lons of oil every day. This large energy de-
mand, coupled with a limited domestic
supply, has required the United States to
import significant quantities of oil to
meet our energy needs. Alaskan oil,
which represents 25 percent of our total
domestic oil production, helps to limit
the nation's dependence on imported oil.
However, as dramatized by the Exxon Val-
dez tanker accident, spills during trans-
portation of this vital resource can result
in devastating effects on our natural en-
vironment.
The Exxon Valdez spill occurred off the
coast of Bligh Island in Prince William
Sound on March 24, 1989. Prince Wil-
liam Sound and its islands contain over
2,000 miles of shoreline. This pristine en-
vironment, which is bordered by national
forests, is home to a wide range of wild-
life, including caribou, grizzly bears,
deer, gray wolves, seals, sea lions, otters,
and whales, as well as an extensive array
of birds. Many commercial fish hatcher-
ies are also located in the protected bays
ringing the Sound. These hatcheries
produce salmon, Pacific herring, halibut,
sablefish, crab, and shrimp. The oil spill
has damaged a significant portion of the
area's diverse wildlife, and directly affect-
ed the lives of many Alaskans.
Environmental safeguards must be es-
tablished to prevent or mitigate similar
tragedies. Federal agencies have begun
studies and investigations to strengthen
both prevention and preparedness. In ad-
dition, Congress is investigating legisla-
tive remedies. The U.S. Environmental
Protection Agency (EPA) Administrator
will also coordinate long-term planning to
restore the environment of Prince Wil-
liam Sound and other affected areas. This
work is expected to yield important
knowledge concerning the long-range en-
vironmental impacts of oil spills
and ways of ameliorating them.
Prevention is the best defense, but be-
cause it may be impossible to completely
prevent spills, research is needed so that
new, more advanced cleanup techniques
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Fishermen deploy an oil boom to protect
' the region's rich herring and salmon hatch-
eries. An estimated 4,000 fishermen work
in the area now affected by the spill.
can be examined and tested. A Report to
the President prepared by the National
Response Team calls for both public and
private research to improve current
cleanup technology. The Alaskan Oil
Spill Bioremediation Study is an impor-
tant step in this direction. The knowledge
gained from this study will enhance the
cleanup efforts underway in Prince Wil-
liam Sound, and help to ensure more
timely and effective remediation of future
oil spills in marine environments across
the world.
Magnitude of the Spill
The Exxon Valdez tanker accident has
resulted in the most massive oil spill in
U.S. history, and the first big spill to foul
the cold waters off Alaska's coast. Patches
of oil or oil-and-water emulsion (globules
of oil suspended in water) have spread
over 3,000 square miles and onto an esti-
mated 1,000 miles of shoreline (including
350 miles in Prince William Sound
alone). In contrast, only 240 miles of
coastline were affected when the Amoco
Cadiz broke up on rocks in the stormy
seas off France's Brittany Coast in 1978.
In that spill, 68 million gallons of oil were
released into the ocean.
The severity of an oil spill's effects on
the environment varies greatly and de-
pends upon many conditions, including:
The type and amount of oil involved.
The degree of weathering.
The geographic location.
The time of year.
The types of plant and wildlife habi-
tats affected.
The life stage of the affected organ-
isms, and their sensitivity to contami-
nation.
By 1984, Brittany's environment had
largely recovered from the effects of the
spill and ensuing cleanup operations. It is
too early to tell if Prince William Sound
will be as resilient. However, a number of
UNITED STATES
OIL CONSUMPTION
Domestic Crude Oil
and Petroleum Products
9,818,000 Barrels/Day
Imported Crude Oil
and Petroleum Products
7,402,000 Barrels/Day
Source: U.S. Energy Information
Administration, Monthly Energy
Review, March, 1989, pp. 50, 57.
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ALASKA AND PRINCE WILLIAM SOUND
ALASKA The name comes from an Aleutian word meaning "great land." If
laid on the 48 lower States, Alaska would cover nearly one-fifth of them. The
State is great in resources as well as land mass. In 1968, enormous quantities
of oil were discovered on Alaska's North Slope in Prudhoe Bay. In 1974, con-
struction began on the Trans-Alaska Pipeline under the direction of the Alyes-
ka Pipeline Consortium Co., which was formed by the seven firms that pump
crude oil from the North Slope. The pipeline extends nearly 800 miles with its
terminus in Valdez, Alaska, where a shipping complex and other facilities are
located. Since the pipeline was built, nearly 9,000 shipments of oil have been
transported through Prince William Sound.
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MAGNITUDE OF OIL SPILLS
ACROSS THE WORLD
Amoco Cadiz
68 million gallons
(off coast of France, 1978)
Torrey Canyon
37 million gallons
(off coast of Great Britain, 1967)
Exxon Va/dez
11 million gallons
(off Valdez, Alaska, 1989)
Argo Merchant
7.5 million gallons (off
Nantucket, Massachusetts, 1976)
Sealift Pacific
1.3 million gallons
(off Cook Inlet, Alaska, 1976)
Source: U.S. Environmental Protection
Agency's Office of Research and
Development, Research Summary: Oil
Spills, February 1979, p. 2.
elements have combined to make the Ex-
xon Valdez oil spill more difficult to con-
tain and clean up than the accident in
Brittany. These include the remoteness of
the area, the extreme weather conditions,
and the lack of preparedness for such a
massive cold-water spill.
The spill occurred in a remote location,
and as the oil spread, it moved to even
more difficult and inaccessible areas. The
town closest to the spill site is Valdez,
which has a population of less than 4,000
residents. Weather also affected the pace
and effectiveness of the oil recovery. Se-
vere weather and gale force winds sus-
pended operations a number of times,
forcing vessels to tow cleanup equipment
to sheltered harbors and coves.
The habitats of the south-central
Alaskan coast also are more vulnerable to
spilled oil than those of more temperate
climates, such as Brittany's, because
subarctic temperatures and resulting
slower rates of physical weathering and
degradation allow the oil to persist. In
addition, oil stranded on some beaches
with low tide or wave action may remain
for several years. Thus, in addition to the
short-term, acute effects (such as wildlife
mortalities) caused by the oil, there is
potential for long-term, sublethal chronic
effects such as habitat and food chain dis-
ruption, as well as decreased survivabili-
ty and reproductivity of animals exposed
to the oil. These effects, while perhaps
not immediately fatal to a given individu-
al, have a direct bearing on the survival of
a species as a whole and consequently on
the balance of the ecosystem of which it is
a member.
Physical Cleanup
Oil spills, even small ones, are difficult
to clean up. The type of cleanup technolo-
gies used varies according to the location
of the spill, the nature of the oil, the
weather, and the natural resources
present. One of the primary concerns in
selecting a cleanup method is to choose
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BEHAVIOR OF OIL IN PRINCE WILLIAM SOUND
Water-jn-Oil
'ttinulsion.jMou
Ingestion and
Egestion by Animals
WHERE DOES IT GO? The recovery rates of crude oil due to massive spills
have typically been low. Winds and waves help spread and disperse the oil,
some of which then evaporates into the air. As the lighter components vapo-
rize, the rest of the oil weathers into a thick black substance that can wash up
on beaches or sink to the ocean floor. Eventually, this weathered oil degrades.
In the meantime, it may contaminate plankton and the small fish that feed on
these microscopic marine organisms. In turn, larger animals in the food chain,
including humans, may eat the contaminated fish. Marine mammals and
birds may also be exposed directly to floating oil in the water. Oil has a sticky
consistency that causes it to adhere to fur and feathers. Animals may ingest
the oil through grooming; sea otters also may freeze to death if their fur be-
comes coated with oil. Herring eggs are also vulnerable to oil. Herring spawn
in the spring months, and their eggs may be smothered by the oil spill and die
outright. If the eggs do survive, the oil may cause abnormalities in the grow-
ing embryos. Should the oil persist in spawning areas, it could have long-term
impacts on the herring population.
Source: National Response Team, The Exxon Valdez Oil Spill: A Report to the
President from Samuel K. Skinner, Secretary, Department of Transportation
and William K. Reilly, Administrator, U.S. Environmental Protection Agency,
May 1989.
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Shortly after the spill, a
bird rescue operation was
begun. Cormorants, ea-
gles, loons, and ducks
were among the birds
brought to the cleaning
and rehabilitation center
established in Valdez.
one that will not cause greater harm to the
environment than the oil itself. Exxon,
along with the State of Alaska and the var-
ious Federal agencies involved in the
cleanup, have used a number of tech-
niques to clean up the floating oil. More
than 10,000 individuals are involved in
these efforts. Specialized equipment,
barges, and several hundred vessels and
aircraft have also been deployed to aid in
the cleanup.
Most of the floating oil in Prince Wil-
liam Sound has disappeared, leaving
shorelines as the main point of contami-
nation. On many beaches, the oil has
weathered into a thick, black layer that
has settled into the fine beach gravel and
covered rock surfaces and cliffs.
High- and low-pressure spraying, steam,
manual scrubbing, and raking of con-
gealed oil have all been used to remove oil
from the surface of rocks and beaches.
These techniques, however, cannot effec-
tively remove all of the oil on the surface
of the beaches, or oil that is trapped un-
der the rocks and in the matrix of sedi-
ments. This is where bioremediation is
especially useful.
Bioremediation
Bioremediation involves the use of
microorganisms (such as bacteria) to
mitigate the effects of oil and other types
of chemicals. The process used in Alaska
relies on the ability of naturally occurring
microorganisms to degrade or break apart
toxic hydrocarbons (such as those found
in crude oil) in marine or other aquatic
environments. Because it does not in-
volve physical disruption of the site, bi-
oremediation is an especially desirable
technology for oil spill remediation.
For several years, the EPA Office of
Research and Development (ORD) has
been studying the microbial degradation
of oil as part of its long-term research pro-
gram. Until the Exxon Valdez accident,
however, no microbial treatment process-
es had been developed for use in remov-
Conventional Cleanup
Methods
Dispersants Chemical so-
lutions designed to reduce the
cohesiveness of oil slicks so
that the petroleum breaks up
into droplets and becomes
diluted in the water. In order to
break up the film, dispersants
must be able to mix into the oil
and be agitated (like detergent
in a washing machine). This
mixing energy can come from
the environment, such as
heavy seas and surf; the appli-
cation technique, such as aeri-
al spraying by airplanes and
helicopters; and the disper-
sants themselves, some of
which are self-mixing. Disper-
sants are most effective on
spilled oil that has not
weathered.
Booms Physical barriers
that contain, deflect, or absorb
oil. Booms are used to prevent
oil from reaching an environ-
mentally sensitive area.
Skimmers "Marine vacu-
ums" that suck up crude oil.
The oil is then transferred to
dredging barges. It is difficult
for skimmers to work when oil
weathers and becomes too
thick for a skimmer's pumps.
Kelp can also clog the pumps.
Burning A flammable sub-
stance applied to oil is cor-
ralled by booms and ignited.
Burning creates residual smoke
that may cause irritation to
nearby residents, and it can
only be performed in favor-
able weather.
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Booms have been used in Prince William Sound to contain the
oil and prevent it from reaching environmentally sensitive
areas. Fence booms (above] are constructed from rigid or semi-
rigid material and serve as a vertical barrier against oil floating
on water. Curtain booms jleftl have a flexible skirt that traps
the oil; the skirt is held down by ballasting weights or a
separate tension line.
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Workers used high-pressure spraying to
clean up greasy rocks. Booms corral the
sprayed oil, which is pumped to a recovery
vessel.
More than 10,000 in-
dividuals took part in the
cleanup effort lleftj; a
worker scrubs an oiled
rock (above/.
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"The Alaska oil spill
tragedy demonstrated the
primitive state of our oil
spill cleanup procedures
and technologies and
the need to develop and
encourage the use of in-
novative cleanup tech-
niques such as
bioremediation."
- William K. Reilly,
Administrator of the U.S.
Environmental Protection
Agency
EPA'S Science Advisory Board
The Science Advisory Board (SAB) was established in 1978 by Congress
under the Environmental Research, Development, and Demonstration
Authorization Act (42 U.S.C 4365). The objective of the SAB is to provide
advice to the EPA Administrator and other Agency officials on the scientific
and technical aspects of environmental problems and issues.
The SAB is composed of engineers and scientists who are recognized
experts in their respective fields. These individuals are drawn from acade-
mia, industry, and environmental communities throughout the United
States, and in some cases, other countries. The SAB conducts its business
in public view and benefits from public input during its deliberations.
Through these proceedings, Agency positions are subjected to critical
examination by leading experts in the field in order to test the currency and
technical merit of those positions.
The SAB's Executive Committee serves as the focal point for the coordi-
nation of scientific reviews by the Board's standing committees. Historical-
ly, five committees have conducted most SAB reviews: 1) the Clean Air
Scientific Advisory Committee; 2) the Environmental Effects, Transport,
and Fate Committee; 3) the Environmental Engineering Committee; 4) the
Environmental Health Committee; and 5) the Radiation Advisory Commit-
tee. In addition, two other committees were recently formed: the Indoor Air
Quality/Total Human Exposure Committee and the Research Strategies Ad-
visory Committee. These seven committees perform various functions, in-
cluding reviewing documents, guidelines, and research activities;
conducting workshops; and working with ad hoc committees.
The Environmental Effects, Transport, and Fate Committee reviewed
ORD's research plan for the Alaskan Oil Spill Bioremediation Project before
the field test began, and commended ORD for its rapid response. The Com-
mittee also pointed to the need for research regarding the ways bioremedi-
ation could be applied to spills and inadvertent discharges of chemicals into
the environment. The Committee believed that EPA's project would be a
significant contribution to future research planning and technology de-
velopment.
ing crude oil from contaminated beaches.
ORD staff suggested that bioremediation
might be useful in enhancing the natural
degradation processes in Prince William
Sound. The Acting Assistant Administra-
tor of ORD convened a panel of over 30
national and international expert scien-
tists in the field of bioremediation to de-
termine the feasibility of using this
technology in Alaska. The panel recom-
mended that ORD plan and conduct a
field demonstration test to determine if
bioremediation would be useful in clean-
ing up the oil.
Because of the importance of quick ac-
tion, ORD went forward with establish-
ing a field office in Valdez soon after the
spill. ORD staff also developed a draft
research plan that was reviewed by EPA's
Science Advisory Board. On June 2,1989,
ORD entered into a cooperative agree-
ment with Exxon to test the capability of
bioremediation in treating contaminated
beaches in Prince William Sound.
Bioremediation is expected to have
beneficial effects on the Alaskan shore-
line in both the near and long term. For
example, certain toxic components of the
oil can be quickly degraded, making
them less available to marine organisms.
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"Bioremediation is a
potentially powerful ap-
proach to reducing the
time required to decrease
the environmental effects
of oil and other chemical
spills."
- Erich Bretthauer, EPA's
Acting Assistant Adminis-
trator for the Office of
Research and
Development
Also, animals and plants that live in the
area will be exposed to fewer toxic com-
ponents of the oil than they would
without bioremediation.
EPA estimates that without bioremedia-
tion, it would take at least 5 to 10 years to
degrade oil on the Alaskan shoreline.
With bioremediation, this period may be
cut in half to as short as 3 to 5 years. It
will, however, take many more years be-
fore all the effects of this oil spill are no
longer detectable in Prince William
Sound and surrounding areas.
The Alaskan Oil Spill
Bioremediation Study
The major portion of the Alaskan Oil
Spill Bioremediation Project involves a
field test to determine if adding fertilizer
to contaminated beaches will effectively
stimulate native bacteria to break down
the oil. Scientists have determined that
hydrocarbon-degrading bacteria do live
in the waters and sediments of Prince
William Sound. However, even in the
presence of large amounts of petroleum,
their growth is limited by the availability
of nutrients (nitrogen and phosphorus),
which are essential for bacteria to utilize
the hydrocarbons as a food source. To
overcome this obstacle, scientists have
added fertilizer to selected test beaches in
Prince William Sound to enhance micro-
bial growth. The rationale behind this
approach is that the more microorgan-
isms there are available to break down the
oil, the faster the rate of degradation.
Site Selection and Preliminary
Testing
Before the test could begin, scientists
had to select a suitable test site. The Alas-
ka Department of Environmental Conser-
vation, the National Oceanographic and
Atmospheric Administration, and the
Seattle EPA Regional Office provided
recommendations for the demonstration
site. ORD surveyed oil-contaminated
Summary of Agreement with Exxon
ORD and Exxon have signed a cooperative research and development
agreement under the authority of the Federal Technology Transfer Act
(FTTA) of 1986 (Public Law 99-502, October 20, 1986, U.S.C. 3710a). The
FTTA encourages collaboration between Federal agencies. State and local
governments, universities, and private industry to improve the economic,
environmental, and social well-being of the United States.
Under the agreement, Exxon pays for all the costs of field operations
directly applicable to the bioremediation study (these include local trans-
portation by helicopter, planes, and boats; field and laboratory facilities; and
subsistence for project participants). EPA pays and is responsible for over-
sight and management of the study. This will ensure the independence of
study results. EPA has also agreed to provide supplemental resources for
other efforts that are necessary to make the technology useful in cleanup of
future spills. Exxon's contribution to the project is about $3 million; EPA's
contribution is approximately $1.6 million.
The agreement also provides for an equitable handling of any inventions
that may come out of the project. The party that patents an invention will
pay the cost of prosecuting the patent. The patenting party also grants the
other a nonexclusive, irrevocable license to use the invention both in the
United States and abroad. Since either party can license any patented in-
vention, the technology will be readily available to other groups needing it.
II
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ORD scientists used helicopters to perform beach surveys of the contaminated shorelines.
beaches on foot and by using small boats,
planes, and helicopters. After identifying
several prime locations typifying Prince
William Sound, test beaches were chosen
on the southern shore of Snug Harbor,
which is situated on the southeastern
coast of Knight Island. The major features
considered in selecting the site were:
Reasonable uniformity of beach
material (cobbles, gravels, or sands)
and oil contamination.
Adequate land size and topography to
set up the needed number of test plots.
Shoreline with a gradual slope.
Minimal influence by freshwater
(streams and snowmelt).
Sufficient shelter from storms during
the test period.
Moderate levels of contamination to
facilitate testing and measurements.
The test beaches selected on Snug Har
bor best met these six characteristics.
A variety of preliminary laboratory and
field tests were also conducted during this
time. In the field, scientists gathered in-
formation about the composition of the
spilled oil, the extent of contamination,
the configuration of the shoreline, the
presence of hydrocarbon-degrading bac-
teria, and the amount of nutrients avail-
able in the test area. Various types of
fertilizers, application methods, and sam-
pling procedures were also evaluated.
Nutrient Application
In early June, two types of fertilizer
were applied to the selected test beaches
in Snug Harbor: a water-soluble fertilizer
(a typical garden fertilizer that releases
nutrients as it slowly dissolves in water);
and an oleophilic fertilizer (designed to
adhere to oil). The water-soluble fertilizer,
which was bagged in herring nets, was
placed on the beach surface and an-
chored in the tidal zone with steel-
reinforced rods. Rain and tides helped
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LOCATION OF SNUG HARBOR
R = Reference
0 = Oleophilic Fertilizer
WS = Water-soluble Fertilizer
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After 3 weeks of bio-
remediation treatment, a
patch of cobblestone
showed significantly less
oil contamination on its
surface.
Prince William Sound is
edged with gravel and
cobblestone shorelines;
much of the oil that has
washed up on these
beaches has degraded into
a thick, gooey layer.
disperse the nutrients to the oil-
contaminated areas. The liquid oleophilic
fertilizer was sprayed over the contami-
nated test areas.
Each fertilizer was applied to two types
of beaches one composed of mixed
sand and gravel; the other made up of
cobblestone. The application strategy was
designed specifically to promote bio-
degradation of oil in both physically
cleaned and untreated beach sediments.
Two "reference" test plots, where no
nutrients were added, also were set up for
comparison against the treatment plots.
The reference plots were physically sepa-
rated from the treatment plots to ensure
that no nutrients would move into these
areas. In all, the six plots occupy approxi-
mately 2,000 square yards of beach area
in Snug Harbor.
Sampling
Several sampling and field testing
methods were used to observe changes in
the composition of the oil, to monitor the
movement of added nutrients in the test
beaches, to detect changes in the number
of bacteria present as the test proceeded,
and to assess the degradation of the oil.
The sampling permitted the scientists to
determine if oil degradation was en-
hanced with no resulting harm to the
ecology of the area.
Microcosms
Microcosms were constructed on board
a fishing vessel to provide supplemental
information to the field demonstration
project. Microcosms are designed to
simulate field operations, but on a
smaller scale. They have the advantage of
providing backup information in the
event of a major storm or some other un-
foreseen complication that could result in
lost field data. The microcosms also allow
scientists to test bioremediation concepts
under idealized conditions to better un-
derstand what may happen in the field.
Six tanks representing the six test plots
were set up on the ship. Perforated con-
tainers filled with contaminated cobble-
stone and contaminated mixed sand and
gravel were placed in the tanks. Then,
water-soluble and oleophilic fertilizers
were applied to simulate the test applica-
tions. Seawater was pumped into the
tanks every 6 hours, and then withdrawn
for 6 hours to imitate tidal cycles. The
microcosms also received equivalent rain
and sunlight as the field plots.
Ecological Monitoring
Ecological monitoring studies were
conducted concurrently with the fertiliz-
er application tests. Although dilution
and tidal mixing should minimize the
14
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An EPA scientist collects
samples for laboratory
analysis on the coast of
Snug Harbor where the bi-
oremediation field tests
were performed.
Two field test plots show
that a site where oleophil-
ic fertilizer was applied is
much cleaner than a site
where no fertilizer was
added. (Inset)
potential for adverse ecological effects,
EPA scientists have been monitoring the
test plots for enrichment or toxic effects
associated with fertilizer addition. For ex-
ample, algal blooms (excessive growth of
algae in a body of water) could occur as a
result of the sudden availability of nitro-
gen and phosphorus. In addition, some of
the byproducts of the degraded oil, as
well as the oleophilic fertilizer, could be
toxic to certain organisms living in the
shoreline zone.
EPA monitored biological activity in
the Snug Harbor waters to determine if
the nutrients were causing algae to grow
too rapidly. Also, 800 mussels collected
from an uncontaminated beach northeast
of Bligh Island were monitored for any ac-
cumulation of toxic substances in their
tissue that may have resulted from the
release or breakdown of the oil. Lastly, a
wide range of native organisms (including
mussels, Pacific herring, King salmon, al-
gae, oysters, shrimp, mysids, and stickle-
back fish) was tested to determine the
potential toxicity of oleophilic fertilizer to
these species.
The Future of Bioremediation
As part of its cooperative agreement
with Exxon, EPA agreed to provide infor-
mation that would help the company de-
cide whether to use bioremediation to
clean up oil-contaminated shorelines in
Alaska during the summer of 1989. By
mid-summer 1989, all data were not avail-
able to make a definitive recommenda-
tion on the efficacy of bioremediation.
However, given the significant potential
positive benefits, the absence of adverse
ecological effects, and the limited time re-
maining in the summer season in Alaska,
EPA informed Exxon that the Agency
would support a proposal for application
of nutrients to Alaska's oiled beaches.
EPA recommended specific procedures to
maximize the technology's effectiveness.
In the winter all cleanup activities, in-
15
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BIOREMEDIATION SCALE-UP:
EPA'S RECOMMENDATIONS TO EXXON
EPA recommended the following procedures be carried out by Exxon
when applying nutrients to oil-contaminated Alaskan shorelines.
Simultaneously apply the oleophilic and the slow-release, water-
soluble fertilizers to oiled beaches wherever possible. Preliminary in-
formation from ORD's field studies shows that the oleophilic fertilizer
enhances the removal of oil from the surfaces of cobblestone and
gravel. However, there is not enough evidence to demonstrate that the
oleophilic fertilizer enhances the degradation of oil beneath large cob-
blestones and at any significant depth in the sediment. EPA believes
that oil degradation in these beach areas would be enhanced by apply-
ing a slow-release, water-soluble fertilizer. The nutrients released from
this fertilizer will be able to penetrate the less accessible areas through
tidal flushing.
Clean up heavily and moderately oiled shorelines prior to nutrient
application. During the initial field studies, scientists observed that it
took a long time for large globs of oil to degrade. Therefore, as much oil
as possible should be removed from heavily and moderately contami-
nated shorelines before fertilizer is applied. For lightly oiled shorelines,
physical cleanup is not necessary prior to nutrient applications.
Use a specific rate of fertilizer application. To ensure the maximum
amount of fertilizer is applied with the minimum impact on the environ-
ment, EPA has recommended specific rates of fertilizer application.
Initially apply the fertilizers on those oil-contaminated shorelines
that are exposed to adequate flushing through the action of tides and
wind to control algal blooms and toxicity. The potential for algal
blooms from the nutrients and toxicity to marine organisms from the
oleophilic fertilizer are greatest in protected, poorly flushed waters. If
sufficient flushing and dilution are questionable, EPA recommends that
ecological monitoring be carried out along with the fertilizer application.
If the monitoring results demonstrate any adverse environmental ef-
fects, the fertilizer application should be terminated immediately.
eluding bioremediation efforts, will be
stymied by extreme weather conditions.
Based upon the results of ORD's
research, Exxon proposed to begin biore-
mediation on nearly 6,000 yards of shore-
line in Prince William Sound. Exxon's
proposal was approved by the Regional
Response Team, which provides expertise,
equipment, and other resources in oil
spill disasters such as the one in Alaska.
The bioremediation application began on
August 1, 1989.
A Delicate Balance
Alaska has been called upon to be both
a source of energy for the United States
and a seemingly endless frontier where
nature is preserved. Actions are being
taken to reduce the occurrence of oil
spills, but in the event of a future spill
in Alaskan waters or elsewhere it is
hoped that the information gained from
EPA's bioremediation project will be use-
ful in enhancing the environment's natur-
al ability to recover.
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