Alanna Maham

(CN) — The U.S. Environmental Protection Agency reported emerging wildlife mortalities on Wednesday evening, stemming from a 25,000-gallon gasoline leak from the Olympic Pipeline in Conway, Washington state, earlier this week.

The spill that began Sunday is now the largest in Washington state in 24 years. According to the most recent update from the EPA and Washington Department of Ecology, the spill began when a small tube leading from the Olympic Pipeline to a pressure gauge failed, causing a leak. According to the agencies, nearly 25,000 gallons of gasoline spilled onto Highway 534 and the surrounding environment, causing the death of three animals in a nearby creek.

"Members of the public are asked not to touch or relocate affected wildlife and to call the wildlife hotline (1-800-22BIRDS)," the agencies wrote. "As reported yesterday, teams have recovered one American beaver, one pine siskin bird and one mallard duck deceased as a result of the spill."

The agencies said responders stopped the leak on Sunday and that multiple government entities have stepped in to help with monitoring and cleanup, including the EPA, the state Department of Ecology, Skagit County Department of Emergency Management, Lummi Nation and the Swinomish Indian Tribal Community.

Pipeline operator BP Pipelines (North America) Inc. — owned by the British Petroleum Company Limited — is also involved in response efforts. BP began shutting down the main pipeline after discovering the pressure loss on Sunday, though residual pressure caused continued leakage for several hours.

The EPA states that of the 25,326 gallons leaked on Sunday, approximately 5,292 gallons remained in the vault and 6,993 gallons have been recovered. Responders have since deployed 2,400 feet of containment and absorbent boom and began skimming fuel from Hill Ditch and Bulson Creek while collecting remaining gasoline from the surface of the field adjacent to the pipeline vault.

Sunday’s spill also closed a portion of the highway and a local elementary school until Tuesday morning. As of Wednesday evening, the state route remained open to one-way traffic while cleanup efforts continued. The EPA reported on Tuesday that the Department of Ecology and BP will continue air monitoring efforts that have thus far indicated no public health risk from gasoline fumes.

Washington state’s last significant spill also occurred on the Olympic Pipeline, a 400-mile interstate pipeline system that runs between Blaine, Washington, and Portland, Oregon. On June 10, 1999, the pipeline ruptured in Bellingham, Washington, spilling over 230,000 gallons of gasoline into Whatcom Creek.

The 1999 incident killed two 10-year-old boys and an 18-year-old after the creek ignited, spurring the establishment of the Pipeline Safety Trust. On Tuesday, a spokesperson for the local oversight group, Kenneth Clarkson, told The Associated Press that seeing another major spill from the same pipeline is “extremely disheartening.”

“This time, we are fortunate that nobody was injured or killed; any spill, and especially one of this size, that happens near our schools and into our treasured waterways and salmon habitat is completely unacceptable,” Clarkson said.

So far, responding government agencies have not observed visible gasoline sheen on the Skagit River and this week's reported animal deaths are the first indications of the spill's effect on wildlife. Whether the gasoline has affected other animal species, including salmon, is yet to be determined.