Birds, fish killed after hundreds of gallons of oil discovered in King County river

A few hundred gallons of oil have appeared near King County’s Black River pump station in Renton, killing both birds and fish.

In late August, employees at the pump station alerted the Department of Ecology of a sheen on the water. Initially thought to be a small spill, the team that investigated found roughly 400 gallons of used cooking oil.

"At this point, we really have no idea where the heck the oil came from," said Agustina Cartagena-Mclean, a lead responder for the Department of Ecology.

Booms have been deployed since early September while crews have worked to recover the oil. However, the oil has forced the nearby fish ladder to be shutdown. It’s especially concerning, given both adult and juvenile salmon have died due to oxygen levels in the water.

Investigators were able to test the oil, and determined that the oil was a majority of saffron oil followed by peanut and olive oil. That led the team to a number of Asian cuisine restaurants, but drains near those restaurants didn’t appear to have the same oil.

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Cartagena-Mclean noted that given the size of the spill, which was initially thought to be half the size, it’s more likely that someone that collects used cooking oils was more likely to be involved. Still, they haven’t found any areas nearby the spill site that indicate a truck that would be needed to carry that much oil has dumped the oil, leaving it an open question—where did the oil come from?

It may take a tip from the public to solve the case. According to Cartagena-Mclean, every rain event makes it harder for them to track down a source. An afternoon rain was the third rain event since the initial discovery of the spill, and previous attempts to trace the local drains provided no new details of where the oil came from.

There is hope that someone knows of a group, or has witnessed a business, that doesn’t follow environmental guidelines in the area. Tips can be sent by calling 360-790-6899.

A number of people walking trails that cut through the Black River Riparian Forest and showcase river views expressed concern over illegal dumping in the area.

"It’s not beautiful," said Aryana Bates, a woman who stopped by the nearby Black River Riparian Forest to walk the trails on Tuesday morning. "I wouldn’t want to be in that water."