Thirty-seven years ago the Exxon Valdez tanker grounded in Prince William Sound and spilled 11 million gallons of crude oil in what was for decades the nation’s worst oil spill. Now, state environmental officials are proposing to remove some of the spill sites from a list of polluted waters.
Of the more than 1,300 miles of coastline fouled by the spill, there are now 11 sites where lingering oil is too degraded, too deeply embedded and too immobile to pose any more water quality problems, according to analysis performed for the Alaska Department of Environmental Conservation.
The department is proposing to remove “impaired” designations from 11 spill-affected sites in its 2026 Integrated Water Quality Monitoring and Assessment Report, a tally required under the federal Clean Water Act.
Among the sites that may be reclassified are some that became famous for the thick coating of spilled oil they received in the immediate aftermath of the tanker’s grounding. They include Sleepy Bay on Latouche Island and Bay of Isles and Herring Bay on Knight Island.
Impaired water body lists, which identify sites that fail to meet water quality standards, are required by federal law of all states every two years.
For Alaska, the assessment of whether specific locations affected by the Exxon Valdez oil spill should still be on the list depends on whether they met state and federal water quality standards, according to the DEC.
“Just as water near a permitted sewage outfall may have pollutants present but remain in ‘attainment’ because it meets strict safety and environmental thresholds, some EVOS beaches may still contain traces of lingering oil while now meeting the legal standards for water quality,” a department statement said.
The draft proposes moving the 11 sites from Category 4b, used for sites that are impaired but have recovery plans in place, to Category 2, used for sites where water quality standards have been attained for at least one designated use.
The state agency’s draft 2026 list also contains another change: a consolidation of sites with lingering oil.
Two years ago, the state’s impaired water body list identified 36 such sites. As of now, the department has merged some of those, leaving a total of 16 sites.
Five of those sites are still considered impaired at the Category 4 level, under the draft list. Those sites are on Smith Island, Knight Island, Eleanor Island and Green Island, and altogether they account for a little under 16 miles of coastline, according to the DEC.
The lingering oil is a reminder of the environmental damage wreaked by the Exxon Valdez disaster and the difficulties encountered in the response to it.
Despite a massive cleanup effort, only about 10% of the spilled oil that fouled waters and beaches was ever recovered, according to the DEC.
Lingering oil posed environmental problems for several years after that, according to the Exxon Valdez Oil Spill Trustee Council, the federal and state organization that administers the funds paid by Exxon to settle government damage claims. Lingering oil leaching out from beach sites slowed the recovery of some species for more than two decades, including sea otters, and some research indicates that long-term impacts from lingering oil were as bad or worse than the initial acute impacts of the spill, according to the trustee council.
As of 2007, after years of weathering and degradation, an estimated 23,000 gallons of spilled oil remained on the beaches. That is about 0.2% of the original spill volume, according to the trustee council. A follow-up survey in 2015 revealed no significant change in that amount, according to the council.
Alaska’s draft 2026 impaired water body list is subject to public review, with comments accepted through April 6. After comments are analyzed, a final list will be produced and sent to the Environmental Protection Agency, DEC said.
The Exxon Valdez sites make up just part of the state’s draft impaired water body list, which includes numerous recommendations for category changes. Impaired water bodies have been identified in places stretching from Interior Alaska to the Aleutians and the southern tip of Southeast Alaska.
Some of those sites have been designated as Category 5, used for water bodies with the worst pollution problems. There were 20 such sites on DEC’s 2024 list, with fecal coliform affecting 13 of them.
The draft 2026 list proposes moving two of those sites, the Katlian River near Sitka and the Little Susitna River in the Matanuska-Susitna Borough, to Category 2 after there were improvements in their turbidity measurements. The draft also proposes moving a different site, Ketchikan Creek, to Category 5 because of fecal coliform problems.