Crews responding to an oil spill at the end of the trans-Alaska pipeline have recovered more than 33,000 gallons of a mix of oil and water from Port Valdez, the U.S. Coast Guard and the Department of Environmental Conservation said. But oil continues to leak into the water.
Response crews believe they’ve stopped the flow from an oil sump buried at the terminal, about a quarter-mile uphill from the Valdez Marine Terminal’s Small Boat Harbor, but beyond the sump, oil is flowing through the ground to the water.
Melissa McKenzie, a public information officer with the U.S. Coast Guard, working as part of the response, said that crews investigating the spill believe that it could have been caused by a clogged valve.
“Maintenance crews, they found debris in the check valve that prevented it from closing fully and that could have allowed oily water from the valve’s water system to backflow into the sump,” she said on Monday.
That may have caused the sump, which is 4 feet diameter and 16 feet deep, to overflow. Now that the sump is contained, crews are working to determine where the oil is flowing as it makes its way from near the sump to the ocean.
“So part of what’s making this so challenging is this is a really rocky area near the low tide line, so that indicates that the flow path is actually below ground,” McKenzie said in a phone interview on Sunday.
As part of the response, crews are excavating around the likely path the oil would take as it flows from the sump down to the water. McKenzie says crews are excavating in certain areas above the site where the oil is entering the water, but that job has been challenging as well.
“So we have snow removal crews clearing, they’re basically digging through snow, ice, dirt, and gravel while also having to be mindful of the pipes and other various lines that are below ground in the terminal,” she said.
Four birds have died in the area and crews have set up additional containment booms around a nearby hatchery and the Valdez Duck Flats which are sensitive ecological areas.
In all, 26,000 feet of boom has been used for containing the spill in the water and 230 people from around the state are working on the response.
The pipeline continues to function normally and several oil tankers have used the terminal since the spill was first reported, about a week ago.
The depth of the sump in the article has been corrected. It is 16 feet, not 30 feet.