The Alaska Department of Environmental Conservation (DEC) at first said an unknown amount of Cook Inlet crude oil was released into the environment on April 1, then revised that figure to under 10 gallons. The crude oil came from an 8-inch oil pipeline located in the Upper Cook Inlet near Granite Point.
On April 3, DEC issued an update, to say Hilcorp successfully and safely evacuated all crude oil from the suspected leaking pipeline by displacing it with filtered seawater. That pipeline is an oil gathering line connecting two of Hilcorp’s platforms in the area. The exact cause of the oil release is unknown and remains under investigation.
While Hilcorp activated its response contractor upon discovery of the spill, six oil sheens were observed, the largest being 10 feet by 12 feet, while two of the sheens were three to four feet by 20 to 25 feet in size, DEC said.
DEC also said that marine mammals likely to be present at the time of the spill include endangered Cook Inlet beluga whales, seal lions, harbor seals, other whales and porpoises.
Also present in the area at the time were likely to be Dolly Varden, rainbow trout, Pacific eulachon, Pacific halibut, Pacific herring, Bering cisco, humpback whitefish, American shad, Walleye pollock, sablefish, Pacific and saffron cod, yellowfin sole and smelt, DEC said.
The discharge occurred within designated critical habitat for Cook Inlet beluga whales. The area is also essential fish habitat for all five species of Pacific salmon.
“It has been less than a week since Hilcorp agreed to temporarily shut down oil and gas production as part of its response to a leaking gas supply line, said Alaska Gov. Bill Walker. “Now Hilcorp has reported a separate leaking oil line, which is significantly more harmful than natural gas.”
The governor said he is deeply concerned about the potential impact to the environment, and that the state’s spill prevention and response team has responded.
Hilcorp Alaska agreed on March 25 to a temporary shutdown of its oil and gas production to reduce environmental impact and safety risks in the wake of the company’s gas line leak in Cook Inlet.
That decision came after discussions between company executives and Walker, who said “Alaskans want peace of mind that our waters are protected.”