United States Office of Research EPA/600/8-89/073
Environmental Protection and Development Revised
Agency Washington, DC 20460 July 1990
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The Alaskan Oil Spill
Bioremediation Study
1990 Update
It has been over a year since the Exxon Valdez spilled
approximately 11 million gallons of crude oil into the
pristine waters off Alaska's Prince William Sound. The
spill, the worst in U.S. history, prompted a monumental
clean-up effort and launched significant scientific
research efforts. In the summer after the spill, the U.S.
Environmental Protection Agency's (EPA's) Office of
Research and Development initiated a bioremediation
field demonstration to determine the feasibility of using
nutrients to enhance the microbial degradation of oil
on the Alaskan shorelines. The study, which is the
largest of its kind ever conducted, has already provided
a wealth of datathatwill have far-reaching implications
for mitigating the effects of future oil spills worldwide.
But there are still questions that remain, questions that
EPA hopes to answer through an intensive research
program of field and laboratory studies this summer.
These studies, some of which are already underway,
complement the clean-up efforts planned for the
summer of 1990, which include bioremediation by
nutrient application to hundreds of widely scattered
segments of shoreline in Prince William Sound. This
brochuredescribesthe Alaskan Oil Spill Bioremediation
Study of 1989, the research initiated during the winter
following the spill, and the field and laboratory activities
planned for the summer of 1990.
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Prince William Sound, Alaska
Back Cover:
From the air, a bioremediated test plot resembled a clean rectangle
etched upon the surface of the beach. The cobblestone plot, which
was located in Snug Harbor, was treated with oleophilic fertilizer
during the summer of 1989.
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Alaska and Prince William Sound
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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, construction began on the Trans-Alaska
Pipeline under the direction of the Alyeska 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 itsterminus in Valdez, Alaska, where a shipping complex and other
facilities are located. Since the pipeline was built, approximately 9,000 shipments of oil
have been transported through Prince William Sound.
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The Aftermath of the Spill
In March of 1989, the supertanker
Exxon Valdez ran aground on Bligh Reef
in Prince William Sound, Alaska,
flooding one of the nation's most pris-
tine and sensitive environments in less
than 5 hours with approximately 11
million gallons of crude oil. The spilled
oil affected up to an estimated 900
miles of shoreline in the Sound. These
islands and their waters are home to a
wide range of wildlife, including deer,
black and brown bears, seals, otters,
and whales, as well as an extensive
array of birds and fish. Commercial
salmon fish hatcheries are also located
in the protected bays ringing the Sound.
In the short term, the oil spill has
taken a toll on the area's diverse wild-
life, and directly touched the lives of
many Alaskans. While the long-term
effects of the spill are still being evalu-
ated, there is the potential for habitat
and food chain disruption, as well as
decreased survivability and repro-
ductivity of animals exposed to the oil.
These effects, while perhaps not im-
mediately fatal to a given individual,
have a direct bearing on the survival of
the speciesasa whole and consequently
of the ecosystem of which it is a
member.
In the immediate aftermath of the
accident, attempts to clean up the
spilled oil were hampered by bad
weather and the remoteness of the lo-
cation. Ultimately, a massive cleanup
was organized that involved more than
10,000 individuals, several hundred
vessels and aircraft, and highly special-
ized equipment. Many conventional
clean-up techniques (such as booms,
high- and low-pressure spraying, skim-
mers, and manual scrubbing) were
employed to remove oil from the sur-
face of the rocks and beaches. These
techniques, however, were unable to
remove all of the oil from the beaches,
or oil trapped under rocks and in the
matrix of beach sediments.
Glaciers have left their mark on the
coastline of Prince William Sound. Coastal
topography is often steep, and ranges from
vertical cliffs to sand, pebble, and boulder
beaches. In some areas, streams and snow
melt also introduce large amounts of fresh
water to the near-shore waters of the
Sound.
Workers used several
techniques, including
high-pressure spraying, to
clean up the spilled oil in
1989.
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The Effects of Oil on the Food Chain
A CHAIN OF EVENTS - Spilled crude oil has the potential to affect every level of the
marine food chain. Floating oil may contaminate plankton, which includes algae, fish
eggs, and the larvae of various invertebrates (such as oysters and shrimp). In turn, the
small fish that feed on these organisms can become contaminated. Larger animals in
the food chain (including bigger fish, bears, and humans) may then eat these
contaminated fish. In addition, marine animals and birds may be exposed directly to
oil in the water column, which they can ingest or get on their fur or feathers. Spilled
oil may also preventthe germination and growth of marine plants and the reproduction
of invertebrates, either by smothering or by toxic effects.
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Enhancing the Cleanup with
Bioremediation
To enhance the clean-up efforts,
the U.S. Environmental Protection
Agency's (EPA's) Office of Research
and Development (ORD) suggested that
hioremediation might be useful. A
panel of national and international ex-
pert scientists in the field of
bioremediation was convened, which
recommended that ORD conduct a field
demonstration project to evaluate the
feasibility of using bioremediation to
assist in clean-up operations.
Bioremediation involves the use
of microorganisms (such as bacteria) to
enhance the "degradation" of oil and
other types of chemicals. Scientists
have observed that biodegradation oc-
curs naturally in the environment af-
ter a spill of crude oil due to the presence
of indigenous microorganisms. These
microorganisms degrade the hydrocar-
bons found in the crude oil (which they
use as a food source) into a harmless
substance consisting primarily of car-
bon dioxide, water, and fatty acids.
A few days after the Alaskan spill,
microorganisms began to multiply
naturally in response to the presence of
oil. With such a bounty of hydrocar-
bons, however, the ability of these mi-
croorganisms to degrade the oil was
limited by the availability of nutrients
(nitrogen and phosphorus). Without
these nutrients, the microorganisms
were unable to fully utilize the hydro-
carbons as a food source.
Therefore, the panel of expert sci-
entists that was convened recom-
mended that ORD apply fertilizers to
designated test beaches in Prince Wil-
liam Sound. These fertilizers would
help the microorganisms to degrade
the oil. The rationale behind this ap-
proach is that the greater the number
of microorganisms or the greater the
microbial activity, the greater the abil-
ity of the organisms to break down the
oil and the faster the rate of degrada-
tion. Bioremediation has the potential
to clean up the oil trapped beneath
rocks and in the beach sediments, and
has the added advantage of being less
disruptive to the environment than
conventional clean-up techniques such
as pressure spraying.
A Cooperative Agreement
Because of the need for rapid re-
sponse, ORD quickly drafted a research
plan for the bioremediation field test
and submitted it to EPA's Science Ad-
visory Board (SAB). The SAB, which
Congress established in the late 1970s
to provide advice to EPA regarding the
scientific and technical aspects of en-
vironmental problems and issues, ap-
proved the research plan with minor
modifications. The SAB also stated that
the project would be a significant con-
tribution to future environmental re-
search planning and technology.
ORD then approached Exxon and
proposed a cooperative effort to con-
duct the bioremediation study under
the Federal Technology Transfer Act
of 1986. The Act encourages collabora-
tion between the private and public
sectors for the economic, environmen-
tal, and social benefit of the United
States.
In early June of 1989, ORD en-
tered into a formal cooperative agree-
ment with Exxon to test the capability
of bioremediation in treating contami-
nated beaches in Prince William Sound.
To ensure the independence of study
results, EPA provided the technical
expertise to carry out the bio-
remediation project, and was respon-
sible for oversight and management of
the study. EPA also agreed to provide
supplemental resources for any other
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Scientists used
backpack sprayers to
apply the liquid
oleophilic fertilizer to
a test beach in Snug
Harbor.
efforts that would be necessary to make
the technology useful in the cleanup of
future spills. Exxon paid for the logisti-
cal support directly applicable to the
study (such as lodging for the scientists
and transportation from Valdez, Alaska,
to the test sites) and for laboratory and
field support. In 1989, EPA's contribu-
tion to the Alaskan Oil Spill
Bioremediation Project was approxi-
mately $1.6 million and Exxon's share
was about $3 million.
Snug Harbor
After planning and mobilizing
staff and facilities, scientists surveyed
beaches to find a suitable test area for
the project. Snug Harbor,
which is located on the
southeastern side of Knight
Island, was selected as the
test site. The area is sur-
rounded by mountains with
steep vertical ascents and
peaks of up to 2,000 feet.
The shoreline, which was
moderately oiled, had a rea-
sonable uniformity of beach
material (cobblestone,
gravel, or sand). The test
area was also sheltered from
storms and subject to mini-
mal freshwater runoff
(streams and snow melt),
which could interfere with
the field tests. The degree
of contamination at Snug
Harbor simulated those
conditions considered typical of a beach
following physical washing (the pri-
mary clean-up procedure used by
Exxon).
Slow-release, water-soluble fertilizer
briquettes were bagged in herring nets and
anchored in the tidal zone on a test beach
in Snug Harbor.
Nutrient application began on
June 8, 1989. Two types of nutrient-
rich fertilizers were applied to the test
beaches:
A slow-release, water-soluble fertil-
izer, in which nutrients were slowly
released and distributed to the oil-
contaminated beach surfaces by rain
and tidal action. Fertilizer "bri-
quettes" (similar in size and weight
to charcoal) were bagged in herring
nets, placed on the beach surface,
and anchored in the tidal zone with
steel-reinforced rods.
• A liquid oleophilic fertilizer, in which
the nutrients adhered to the oil cov-
ering the rock and gravel surfaces,
thereby making nitrogen and phos-
phorus available at the site of micro-
bial activity. This fertilizer was
sprayed over the contaminated test
areas.
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Beach Name
Seal
Seal
Seal
Otter
Otter
Eagle
1 SnugHarbons
Snug Harbor Test Plots
I William Sound,
Beach Type Nutrient Application | Alaska. A small
Cobble
Cobble
Cobble
Mixed sand and gravel
Mixed sand and gravel
Mixed sand and gravel
None (reference)
Oleophilic
Water-soluble
Water-soluble
Oleophilic
None (reference)
promontory divides
Seal Beach from Otter
Beach, while a more
conspicuous
promontory divides
Eagle Beach from
OtterBeach.
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A test plot in Snug
Harbor where the
oleophilic fertilizer
was applied looked
dramatically cleaner
than an adjacent
untreated plot.
Each fertilizer was applied to two
types of beaches—one comprised of
mixed sand and gravel; the other made
up of cobblestone. Two "reference"
test plots, where no nutrients were
added, also were set up for comparison
against the treatment plots.
Approximately 2 weeks after the
oleophilic fertilizer was applied to the
cobblestone beach plot, scientists ob-
served visible reductions in the amount
of oil on rock surfaces. This was par-
ticularly evident from the air, where
the contrast with oiled areas surround-
ing the plot was dramatic. To the sci-
entists who surveyed the test plot by
helicopter, it looked as if a clean rec-
tangle had been etched on the beach's
surface. Close examination of this
treated cobblestone plot verified that
much of the oil on the rocks' surfaces
was gone, although oil remained in the
mixed gravel below the rocks.
EPA scientists also observed re-
duced amounts of oil in the mixed sand
and gravel beach plot treated with
oleophilic fertilizer within 2 weeks,
though the difference between the
treated area and its reference plot was
not as striking as that observed on the
cobblestone beach. This is because tides
mixed up the sand and gravel, whereas
the cobblestone remained relatively
stationary. Therefore, the visual disap-
pearance of the oil was less apparent in
the sand and gravel plot. The oil below
the beach surface was disappearing as
well. All other plots (including those
treated with only the fertilizer bri-
quettes) appeared as oiled as they had
been at the beginning of the field study.
Over the next 2 to 3 weeks, the
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cleaned rectangle on the cobblestone
beach remained clearly visible. The oil
in the sand and gravel below the
cobblestone persisted, but became less
apparent over the course of the sum-
mer. The oleophilic-treated mixed sand
and gravel plot also appeared increas-
ingly cleaner than its untreated refer-
ence plot. Beaches treated with the
fertilizer briquettes were relatively
unchanged.
Toward the end of the summer
season, the entire test area became
steadily cleaner. Most of the areas sur-
rounding the test plots were also
cleaner,- scientists attributed this to
several storms and frequent rainfall,
which helped replenish nutrients in
this area and enhance the natural bio-
degradation processes. However, a
heavily oiled area south of Snug Harbor
that was never treated remained con-
siderably contaminated, suggesting
that nature alone could not account for
the dramatic reduction of oil observed
in the test area.
Passage Cove
Based on the promising results of
the initial field test at Snug Harbor and
the absence of any adverse effects on
the area's ecosystems, EPA recom-
mended to Exxon in July that the
bioremediation efforts be scaled up
during the remainder of the summer.
Passage Cove served as the main refer-
ence beach for a large-scale application
of nutrients by Exxon clean-up crews,
which commenced on August 1,1989.
Passage Cove, which is located on
the northwestern side of Knight Island,
had been heavily oiled by the spill.
Even though the site had been physi-
cally washed by Exxon clean-up crews,
considerable oil remained on the
shoreline and in the beach sediments.
In fact, contamination was discovered
as far as 2 feet below the surface. Scien-
tists did find, however, that the physi-
cal washing had spread the oil into a
very thin layer over a large surface area
of rock and gravel, which made it easier
for the microorganisms to gain access
to and break down the oil.
Scientists set up three beach plots
for research at Passage Cove. All of the
plots were comprised of cobblestone
overlaying sand and gravel. The
oleophilic fertilizer and a granular form
of a slow-release, water-soluble fertil-
izer were applied in tandem to one test
plot. These fertilizers were applied to-
gether because subsurface oil contami-
nation was a concern at Passage Cove
and there were some questions about
how deep the oleophilic fertilizer could
penetrate the beach's subsurface. Un-
like the water-soluble fertilizer, the
oleophilic fertilizer has a syrup-like
consistency which could hinder its
ability to permeate the subsurface.
A third type of fertilizer, a fertil-
izer solution containing inorganic ni-
trogen and phosphorus dissolved in
seawater, was sprayed across the sec-
ond test plot by fixed sprinkler systems
(similar to lawn sprinklers). An
untreated reference plot was also set
up for comparison purposes.
Within 2 weeks following the ap-
plication of the oleophilic and water-
soluble fertilizers, the treated beaches
were considerably cleaner than the ref-
erence plot. Not only did the rock sur-
faces look cleaner, but the oil beneath
the cobblestone was also disappearing.
The beach plot treated with the fertil-
izer solution from the sprinkler system
behaved in a similar manner, and be-
came steadily cleaner. The reference
plot showed no sign of oil loss. By the
end of August, the treated plots looked
equally clean. In contrast, the refer-
ence plot appeared very much as it did
in the beginning of the field study. Oil
in the subsurface still remained in all
the test plots.
9
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Passage Cove
Passage Cove is
located on Knight
Island in Prince
William Sound,
Alaska. The test plot
in Tern Beach was
divided by a
promontory.
Passage Cove Test Plots
Beach Name Beach Type
Raven
Tern
Cobble over mixed sand
and gravel
Cobble over mixed sand
and gravel
Kittiwake Cobble over mixed sand
and gravel
Nutrient Application
None (reference)
Oleophilic and water-
soluble
Nutrient solution
sprinkler system
10
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Hydrocarbon Analyses
To confirm that biodegradation
was indeed taking place, scientists per-
formed a variety of chemical analyses
in the laboratory. These analyses indi-
cated that over the summer, smaller
and smaller concentrations of hydro-
carbons were present in the oil samples
taken at the test sites, thereby con-
firming that biodegradation was oc-
curring (see page 12). Scientists
measure hydrocarbon concentrations
through the use of gas chromatogra-
phy. Oil is really a mixture of many
different hydrocarbons, each with a
specific boiling point. A boiling point
is the temperature at which a com-
pound will "volatilize" or turn to vapor.
Gas chromatography capitalizes on the
differences in boiling points among
different hydrocarbons to separate,
identify, and indicate the relative con-
centration of each of these components
in crude oil.
Ecological Monitoring
Ecological monitoring studies
were conducted concurrently with the
fertilizer application tests at both Snug
Harbor and Passage Cove. Although
dilution and tidal mixing should mini-
mize the potential for adverse ecologi-
cal effects, scientists were concerned
that certain components of the
oleophilic fertilizer could be toxic to
some marine species. In addition, algal
blooms (excessive growth of algae in a
body of water) could occur as a result of
the sudden availability of nitrogen and
phosphorus. Too many nutrients in a
water body reduce the amount of oxy-
gen present, thereby favoring plant life
over animal life.
To determine the potential toxic-
ity of oleophilic fertilizer to native or-
ganisms, a wide range of species
(including stickleback fish, Pacific
herring, silver salmon, mussels, oys-
ters, shrimp, and mysids) was tested.
EPA scientists collected samples of
seawater directly over the beaches that
had just been treated with a combina-
tion of the oleophilic and water-soluble
fertilizer (a "worst-case" scenario).
Laboratory studies with these
samples showed that certain compo-
nents of oleophilic fertilizer are mildly
toxic to the most sensitive marine spe-
cies (oyster larvae) where there is no
dilution by tidal action. Oyster larvae
are two orders of magnitude more sen-
sitive than salmon. The potential tox-
icity of the fertilizer to salmon is a key
concern since these fish spawn in Prince
William Sound. The circumstances of
fertilizer application, however, are such
that the potential to adversely affect
marine and terrestrial life is very un-
likely. Scientists also found that add-
ing nutrients to oiled shorelines did
not cause any increases in algae, or any
measurable nutrient accumulation in
adjacent embayments.
EPA scientists also placed mus-
sels in cages just offshore from the
fertilizer-treated beaches and moni-
tored them to determine if any toxic
substances were accumulating in their
tissues due to the release or breakdown
of the oil. No oil was detected in the
mussel tissues, and no oil was observed
in the water offshore from the test
areas.
Microcosms
Microcosms were constructed on
board a fishing vessel to provide
supplemental information to the field
demonstration project. Microcosms are
designed to simulate naturally occur-
ring processes on a smaller scale. They
ha ve the advantage of providing backup
information in the event some unfore-
11
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a 2
Snug Harbor-Mixed Sand and Gravel-Untreated Beach
Jl
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Sampling Date: 6/8/89
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Sampling Date: 7/29/89
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Hydrocarbons
Snug Harbor-Cobble-Water Soluble Fertilizer
Sampling Date: 6/8/89
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Sampling Date: 7/29/89
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Snug Harbor-Mixed Sand and Gravel-Oleophilic Fertilizer
Sampling Date: 6/8/89
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Sampling Date: 7/29/89
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Hydrocarbons
HYDROCARBON ANALYSES - These figures illustrate how the composition of oil
extracted from Snug Harbor test plots changed from early June to late July of 1989.
Crude oil is a complex mixture of many compounds, including numerous hydrocarbons.
Hydrocarbons, as the name implies, are made up of chains of carbon and hydrogen
atoms. The numbers along the bottom of the graphs refer to the number of carbons in
each hydrocarbon chain in the samples of crude oil. The height of the bar indicates the
relative concentration of each hydrocarbon in the sample.
While all of the July chromatographs show reduced amounts of hydrocarbons
compared to the June graphs (indicating that degradation was taking place), the treated
plots show more pronounced reductions relative to the untreated reference plot,
indicating that degradation was enhanced in the treated plots.
12
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seen complication results in the field
data. The microcosms also allow sci-
entists to test bioremediation concepts
under idealized conditions to better
understand what is happening in the
field.
Tanks representing the test plots
were set up on the fishing vessel.
Perforated containers filled with con-
taminated cobblestone and contami-
nated mixed sand and gravel were
placed in the tanks. Fertilizers were
then applied to simulate the actual
test applications. The initial micro-
cosm results indicated that if suffi-
cient nutrients were supplied to the
microorganisms, enhanced biodegra-
dation of the oil would occur. Because
microcosms represent the test systems
that best reflect field conditions, a
similar response could be expected in
the field.
The Culmination of the
Project
By the end of September 1989,
Exxon had treated 74 miles of shore-
line in the largest bioremediation
project ever conducted. Pontoon boats
and other small craft were used to
access the shoreline, and crews used
airless spray pumps to apply fertilizer
to the oiled beaches. This large-scale
application of fertilizer was the culmi-
nation of the knowledge and experi-
ence gained during the previous
months.
Winter Research
Overall, the initial findings from
last summer's field and laboratory tests
indicate that using nutrients to en-
hance biodegradation is effective and
environmentally safe. To further
strengthen the success of this
bioremediation approach, a variety of
questions still must be addressed about
the fertilizers, the application meth-
ods, the potential for adverse effects,
and other details. Answering these
questions is critical to both the present
and future application of bio-
remediation techniques to oil-con-
taminated beaches. Thus, EPA and
Researchers set up
microcosms on board a
fishing vessel to simulate
test plots in the field and
provide backup data.
During the large-scale
application of fertilizers
in 1989, Exxon crew
members usedpontoons
and other small craft to
apply the fertilizer to
contaminated beaches.
13
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Exxon initiated additional research in
the winter following the spill to ad-
dress questions remaining in the fol-
lowing key areas:
1. The mechanism by which the
oleophilic fertilizer works.
While the summer study demon-
strated that the oleophilic fertilizer ef-
fectively cleaned oiled beaches, the
precise mechanism by which this fer-
tilizer works needed further clarifica-
tion. Because of the dramatic effect of
this fertilizer in the field, there were
concerns that it was possibly washing
the oil from the surface of rocks. Labo-
ratory studies during the winter, how-
ever, confirmed that the oleophilic
fertilizer enhanced the extent and rate
of oil degradation through the addition
of inorganic nutrients. The fertilizer
may also have enhanced biodegrada-
tion by indirectly increasing the num-
ber of oil-degrading microorganisms
present in the beach sediments.
2. The optimization of fertilizer
application.
The oleophilic and water-soluble
fertilizers were applied in combination
at Passage Cove in 1989 to provide
maximal distribution of nutrients to
oil-contaminated areas. Yet, there are
still some questions regarding the opti-
mal use of this combined treatment.
For instance, could any reactions occur
that might reduce the effectiveness of
one or the other fertilizer? What appli-
cation sequence should be considered
for these two fertilizers? Such ques-
tions must be answered to ensure the
optimal application of nutrients in the
field.
3. The potential for adverse
ecological effects.
During the summer field study,
questions were raised concerning the
potential for enhanced biodegradation
to produce by-products that may be
harmful to the environment. Acute
and chronic tests with crustacean and
fish species were conducted during the
winter program that indicated no rea-
son for concerns in this area.
4. The relationship between
nutrient application and algal
blooms.
Scientists are conducting math-
ematical studies to determine the rela-
tionship between nutrient application
and enhanced algae growth. Through
these studies, scientists will be able to
predict what will happen to nutrients
in the environment, including how the
nutrients are likely to be transported
and mixed, and how they will be uti-
lized by the microorganisms. The
studies will help scientists determine
the effects that may be expected from
any new experiments involving nutri-
ents (and other chemicals).
5. The analytical procedure for
measuring oil degradation.
Oil degradation is commonly
measured by extracting oil from beach
material and then analyzing its com-
position in the laboratory to determine
the number and type of hydrocarbons
present. Oil degradation has been ex-
tensively studied over the last 20 years,
and scientists know that certain hy-
drocarbons in crude oil degrade quickly,
while others are slow to
degrade. Scientists frequently use some
of the slower degrading hydrocarbons
as "internal markers," against which
the degradation rate of more quickly
degrading hydrocarbons can be mea-
sured. In Alaska, however, scientists
discovered that the common internal
marker hydrocarbons were also rapidly
degraded in some cases. This made the
established procedure for measuring
oil degradation of limited use, and so
new analytical procedures are needed.
14
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If scientists can develop a new internal
marker technique, it will improve their
ability to assess oil degradation in the
field.
6. The statistical verification of
field data and the modification, if
necessary, of sampling
procedures.
EPA is developing statistical pro-
cedures and computer programs that
will allow scientists to further analyze
the collected data, examine important
trends, and modify sampling proce-
dures, if necessary. Scientists are also
reevaluating selected chemical and
biological measurements used to study
oil degradation to focus^on more sensi-
tive, less variable approaches.
Although these six studies were
begun in the winter, many of them will
continue throughout the summer of
1990 in conjunction with field research
activities.
Activitiesforthe
Summer of 1990
A Bioremediation Monitoring
Program will be conducted early in the
summer of 1990. The program will
supplement many of the studies from
the winter research and enhance
bioremediation application activities
planned for the remainder of the sum-
mer. The program is designed to moni-
tor Exxon's large-scale application of
nutrients. It will be a joint undertaking
by EPA, Exxon, the National Oceanic
and Atmospheric Administration
(NOAA), and the Alaskan Department
This clump of sand and
gravel shows the
consistency of oil in the
summer of 1989. By the
summer of 1990, much of
this oil had weathered
into a thicker, more glue-
like consistency.
The Character of
Crude in 1990
The character of crude oil found on the shorelines
of Prince William Sound in 1990 will differ from the oil
that was present in 1989. After an oil spill occurs in a
marine environment, winds and waves help spread
and disperse the oil. Some of this oil will evaporate. Oil that mixes with the seawater
produces an oil-in-water emulsion (globules of oil suspended in water), commonly
referred to as "mousse." Although mousse was prevalent in 1989, cleaning activities
and weathering have significantly reduced its occurrence in 1990.
As time goes by, oil that has washed ashore becomes more glue-like in character
and may eventually form into a hard layer of weathered oil or weathered oil mixed with
fine sediments. This covering, which has the look and consistency of asphalt, is called
a tarmat. Tarmats are found on some shorelines in Prince William Sound. Some of
these sites will be considered for bioremediation after the tarmats are removed.
Oil may also penetrate a beach surface by seeping into the matrix of sediments or
by being buried by clean sediments that have washed over the area. On some
shorelines, pockets of subsurface oil may persist. Bioremediation holds great promise
for cleaning up these areas in the summer of 1990.
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This sheltered "low-
energy" beachis
exposed to minimal
wave action and
consists of poorly
sortedgravel and
cobble.
of Environmental Conservation
(ADEC). The monitoring program will
focus on assessing three key effects of
bioremediation:
The amount of enhanced microbial
degradation of surface and subsurface
oil that can be achieved by nutrient
addition.
The potential toxicity associated
with nutrient addition.
• The amount of nutrients present in
the water off treated beaches.
In the spring of 1990, shoreline
conditions were surveyed to determine
the extent of contamination in Prince
William Sound. Heavy winter storms,
along with the natural processes of
weathering, had decreased the amount
of oil present on the shorelines. Never-
theless, oil remained on many shore-
lines and in the subsurfaces of some
beaches. Tarmats, thick asphalt-like
coverings of oil, were also scattered at
sites throughout the Sound.
Based on these surveys, three types
of beaches were chosen to serve as sites
for the monitoring program: 1) a low-
energy beach with surface and subsur-
face contamination,- 2) a moderate/
high-energy beach with surface and
subsurface contamination; 3) a moder-
ate/high-energy beach with subsurface
contamination. Terms such as "high-
energy" and "low-energy" refer to the
degree of wave energy to which a beach
is exposed. Over 80 percent of the
coastline in Prince William Sound ex-
periences high or moderate wave en-
ergy levels.
The selected beaches are uni-
formly oiled and large enough to be
divided into two areas: one will be
treated by fertilizer, and the other will
remain untreated to serve as a refer-
ence plot. Water and sediment samples
will be taken on specific days after
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Clean-up Techniques for the Summer of 1990
In addition to bioremediation of approximately 400 sites, five other techniques will be
used to clean up the oil that persists in Prince William Sound and the Gulf of Alaska. These
techniques, which were chosen because they are the least disruptive to the environment.
Sorbent Booms. Sorbent booms are physical barriersthat intercept
and absorb oil. They will be used in areas where oil sheens persist.
The booms will be anchored near shore and replaced as necessary.
Manual Pickup. Small beach crews will use hand tools to pick up and
bag oily materials. Manual pickup will help improve the aesthetic
appearance of the beaches and remove potential sources of oily
debris that could foul fishing gear.
Tarmat Breakup/Removal. Tarmats, thick asphalt-like coverings of
oil which are slow to degrade, will be broken up with hand tools and
either scattered (to facilitate natural degradation or bioremediation)
or removed.
Tilling/Raking. In some areas, sediments will be raked or tilled in
order to expose subsurface oil to natural degradation or
bioremediation.
Spot Washing. Crews will use hand-held washing devices to remove
small accumulations of oil. The water and removed oil will then be
collected on the shoreline with sorbents (such as booms or "pom-
poms" that are designed to absorb oil).
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nutrient application and analyzed for
microbial activity and the amount of
nutrients and oil present. Scientists
will also use time-lapse photography
to characterize the visual changes in
the extent of surface oil.
The Research Component
In addition to the Bioremediation
Monitoring Program, EPA, Exxon,
ADEC, and the University of Alaska,
Fairbanks, will conduct research dur-
ing the summer of 1990. Scientists
from all four organizations will par-
ticipate in designing and performing
experiments, and in collecting and in-
terpreting the data.
The research planned for the
summer of 1990 is designed to address
certain questions about the effective-
ness and environmental safety of
bioremediation that remain only partly
answered. The research program will
also address questions that will be
important for future applications of
bioremediation to oil-contaminated
beaches.
EPA will conduct experiments to
answer the following key questions:
• How much total oil removal at a
given site can be expected from
bioremediation?
Scientists will conduct an
experiment to determine the rate and
extent of degradation that can be
anticipated when different
concentrations of fertilizer are applied
to contaminated beaches. Samples
will be taken and analyzed in the
laboratory. From these analyses, the
scientists will determine what
nutrient concentrations must be
maintained on the beaches to remove
a given amount of oil.
What is the best fertilizer application
method for the bioremediation of
subsurface oil?
Scientists believe that oil
degradation occurs at the top and/or
the bottom of a subsurface oil layer
(as opposed to throughout the layer).
Therefore, nutrients must be
consistently applied to these areas
in order to enhance microbial
degradation of oil. Fertilizer
application will be tested on short
stretches of beaches with a distinct
layer of subsurface oil contamination..
The sprinkler application system
used in the summer of 1989 at Passage
Cove will be tested on one beach
plot. Bathing techniques will be
tested on another plot. These
techniques will work by saturating a
test area with a fertilizer solution so
that nutrients can seep through beach
sediments into the oiled subsurface.
An untreated plot will serve as a
reference plot for comparison
purposes.
Can the fertilizer application strategy
for the combined use of oleophilic
and granular water-soluble fertilizer
be further optimized to assure
maximal degradation?
This summer, bioremediation will
be tested on beaches with
considerably heavier concentrations
of oil than those tested last year. To
optimize the effects of these
fertilizers, it is important to remove
as much oil as possible in the shortest
timeframe. Therefore, scientists will
explore applying the oleophilic and
water-soluble fertilizers in different
combinations using laboratory
microcosms with fresh oiled beach
material. Microcosms will permit
scientists to determine the optimum
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application strategy without
involving costly field operations.
• Can additional information on
biodegradation activity be obtained
using new experimental measure-
ments and analyses?
To gain the most benefit from the
monitoring program, as much evidence
for enhanced hiodegradation must be
derived as possible. This means taking
advantage of new analytical techniques
that are not quite ready for routine use,
but that can betestedon samples taken
as part of the monitoring program. Sev-
eral state-of-the-art techniques for
measuring oil degradation will be
tested.
The research data gathered during
the summer of 1990 will be used to
supplement findings from the moni-
toring program to provide comprehen-
sive assessments on the effectiveness
of bioremediation.
Testing New Products
ORD is also evaluating the ability
of several commercial products to en-
hance bioremediation in Alaska. In
February of 1990, ORD announced in
the Commerce Business Daily that it
was seeking organizations or compa-
nies that could offer commercial
methods capable of enhancing the bio-
degradation of crude oil residues in
Alaska. The Agency requested that
these proposals be submitted to the
National Environmental Technology
Applications Corporation (NETAC).
NET AC is an organization established
through a cooperative venture between
EPA and the University of Pittsburgh.
As requested by EPA, NET AC as-
sembled a Bioremediation Products
Evaluation Panel that met in March of
ORD/NETAC: Bringing Innovative
Technologies to the Market
EPA and the University of Pittsburgh Trust have
entered intoarnulti-yearcooperativeagreement
to establish the National Environmental
Technology Applications Corporation (NETAC).
NETAC's purpose is to facilitate the
commercialization of technologies being
developed by the government and the private
sector that will positively affect the nation's
most pressing environmental problems.
NETAC's efforts encompass encouraging new
technologies with promising commercialization
potential, as well as innovations aimed solely at
modifying and improving existing technologies
or processes.
1990 to evaluate each of the 39 propos-
als submitted. The panel used detailed
screening criteria to evaluate the pro-
posals. Eleven proposals (two nutri-
ents, one dispersant, and eight
microbial cultures) were recommended
for further testing, along with a proto-
col for performing this testing.
Ten vendors supplied products for
further testing. To evaluate these prod-
ucts, EPA scientists placed cleanbeach
material, weathered crude oil, seawa-
ter, and the commercial product in
glass flasks. The scientists performed
three different tests on these products.
The tests measured the degradation of
the oil, the change in the numbers of
oil-degrading microorganisms, and the
amount of oxygen used by microorgan-
isms while degrading oil. (Increased
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oxygen consumption is often an indi-
cator of increased microbial activity.)
The Bioremediation Products
Evaluation Panel will evaluate the re-
sults of these tests. It appears likely
that products having successful test
results will be approved for field tests
during the summer of 1990.
The Wave of the Future
Bioremediation is a technology
that holds enormous promise for the
future. The successful field and labora-
tory tests already completed indicate
that bioremediation by nutrient addi-
tion offers a safe and effective way to
ameliorate surface and
subsurface oil. The activi-
ties planned for the summer
of 1990 are expected to
verify these conclusions,
and further expand our
knowledge.
While prevention is
the best defense, it is im-
portant that technologies
also be developed to com-
bat those oil spills that do
occur. For this reason,
research efforts like the
Alaskan Oil Spill Bioreme-
diation Project are crucial.
By understanding the sci-
ence of those processes that
can mitigate the potentially
devastating effects of oil
spills, we can help ensure
the preservation of our rich
and diverse natural envi-
ronment.
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