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THE EXXON VALDEZ
What happened on 24 March 1989
The Oil Spill
Shortly after midnight on 24 March 1999, the T/V
Exxon Valdez ran aground on Bligh Reef in Prince William sound,
Alaska, spilling almost eleven million gallons (about 18 000 000 litres)
of North Slope Crude oil. It was the largest tanker spill in United
States history. That spring the oil moved along the coastline of Alaska,
contaminating portions of the shoreline of Prince William Sound, the
Kenai Peninsula, lower Cook Inlet, the Kodiak Archipelago, and the Alaska
Peninsula. Oiled areas included a National Forest, four National Wildlife
Refuges, three National Parks, five State Parks, four State Critical
Habitat Areas, and a State Game Sanctuary. Oil eventually reached shorelines
nearly 600 miles (960 km) southwest from Bligh Reef where the spill
occurred.
Response
During 1989, efforts focused on containing and cleaning up
the spill, and rescuing oiled wildlife. Skimmers worked to remove oil
from the water. Booms were positioned to keep oil from reaching salmon
hatcheries in Prince William Sound and Kodiak. A fleet of private fishing
vessels known as the Mosquito Fleet played an important role in protecting
these hatcheries, assisting the skimmers, and capturing oiled wildlife
and transporting them to rehabilitation centres. Exxon began to clean
up the beaches under the direction of the US Coast Guard with advice
from federal and state agencies and local communities. Several thousand
workers cleaned shorelines, using techniques ranging from cleaning rocks
by hand to high-pressure hot-water washing. Fertilisers were applied
to some oiled shorelines to increase the activity of oil-metabolising
microbes, an activity known as `bioremediation'.
The 1989 shoreline assessment, completed after the summer cleanup ended,
showed that a large amount of oil remained on the shorelines. In the
spring of 1900, the shoreline was again surveyed in a joint effort by
Exxon and federal and state governments. The survey showed that much
work remained to be done. The principal clean-up method used in 1990
was to manually remove the remaining oil, but bioremediation and relocation
of oiled beach material to the active surf zone were also used in some
areas.
Shoreline surveys and limited clean-up work occurred in 1991, 1992,
1993 and 1994. In 1992, crews from Exxon and the state and federal governments
visited 81 sites in Prince William Sound and the Kenai Peninsula. They
reported that an estimated seven miles (approx. 11 km) of the 21.4 miles
(approx. 32 km) of shoreline surveyed still showed some surface oiling.
This number does not include oiling that may have remained on shorelines
set aside for monitoring natural recovery. The surveys also indicated
that subsurface oil remained at many sites that were heavily oiled in
1989. No sites were surveyed on Kodiak Island or the Alaska Peninsula
in 1992. Earlier surveys suggested that most of the light oil (scattered
tar balls and mousse) which remained on Kodiak Island and the Alaska
Peninsula would degrade by 1992. While there may be a few exceptions,
the surveys determined that the cost and potential environmental impact
of further clean-up was greater than the problems caused by leaving
the oil in place. The 1992 clean-up and the 1993 shoreline assessment
were concentrated in those areas where oil remained to a greater degree
- Prince William Sound and the Kenai Peninsula.
In 1994, restoration workers performed manual treatment to accelerate
degradation of surface oil on approximately a dozen important subsistence
and recreational beaches in western Prince William Sound. They also
performed manual treatment to accelerate degradation of subsurface oil
beneath approximately a dozen oiled mussel beds in protected areas of
Prince William Sound.
Natural Resource Damage Assessment
During the first summer after the spill, one state and three
federal government agencies directed the Natural resource Damage Assessment
field studies to determine the nature and extent of the injuries as
needed for litigation purposes. The federal agencies were the US Department
of the Interior, the US Department of Agriculture and the National Oceanic
and Atmospheric Administration. The state agency was the Alaska Department
of Fish and Game. Expert peer reviewers provided independent scientific
review of ongoing and planned studies and assisted with the synthesis
of results. Most damage assessment field studies were completed during
1991.
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