Sewer utility crews accelerate cleanup efforts in Ravenna Creek

An extraordinary level of environmental cleanup in Ravenna Creek and the Union Bay Slough is getting under way following a serious sewage spill discovered on May 23.

On Saturday, sewer utility crews will use six vacuum trucks to remove contaminated sediments and improve water quality to allow reopening of public recreation areas that have been closed for the past two weeks.

King County’s Wastewater Treatment Division implemented more aggressive cleanup measures after daily water quality monitoring continued to show elevated bacteria levels at two of the county’s seven sampling sites south of Northeast 45^th Street.

To enable cleanup, sewer utility crews temporarily diverted Ravenna Creek into the King County wastewater treatment system and used pumping equipment and dams to contain and remove contaminated water from the University Slough Drainage Canal.

“It was encouraging to see water quality quickly returning to normal following our initial cleanup efforts after we stopped the spill,” said Wastewater Treatment Division Director Christie True.

“The problem was the slough between Northeast 45^th and Clark Road because it’s narrow and moves slowly. We were concerned that the high bacteria levels would affect public health because the downstream area gets a lot of public use,” said True.

“We decided we needed to do more. Swimmers and boaters want the waterway opened as quickly as possible, and we do, too,” she added.

An estimated 8 million gallons of sewage overflowed from a stormwater pipe into the creek over a 10-day period ending May 23. The overflow occurred after county employees mistakenly diverted wastewater into the stormwater pipe during a county project to repair a wastewater regulator gate in the Lake City Tunnel.

The county Wastewater Treatment Division is working in coordination with the City of Seattle, Washington Department of Ecology, Public Health – Seattle & King County, University of Washington Health and Safety, Washington Department of Fish and Wildlife, Muckleshoot Indian Tribe, and King County Water and Land Resources Division.

King County will continue monitoring and provide sample data to Public Health, the Department of Ecology and the University of Washington. The area will be reopened when there is consensus that remediation efforts are complete and the area is safe for public access.

Public Health reports that the risk for human illness associated with this event is low and that no sicknesses have been reported as a result of the spill.

Learn more about the wastewater spill and the county’s response online at
http://dnr.metrokc.gov/wtd/community/sewer-spill-response/0805-RavennaCreek.htm.

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Note to editors and reporters: Visit the WTD Newsroom, a portal to information for the news media about the Wastewater Treatment Division, King County Department of Natural Resources and Parks: http://dnr.metrokc.gov/wtd/newsroom/.

Related Information

Ravenna Creek Wastewater Spill

King County Wastewater Treatment Division