Combined Sewer Overflow Taints Willamette River; Avoid Contact For 48 Hours, Officials Say

PORTLAND, OR — Residents are encouraged to avoid contact with the Willamette River from the Morrison Bridge to the Columbia River confluence for the next 48 hours due to three different combined sewer overflows Wednesday, according to Portland Bureau of Environmental Services spokeswoman Diane Dulken. Patch previously reported on one overflow that occurred early Wednesday but learned Thursday that two others occurred later Wednesday afternoon.

Around 4:15 a.m. Sept. 20, a combination of stormwater (roughly 80 percent) and sewage (about 20 percent) overflowed for four minutes at an East Portland pump station, dumping about 3,000 gallons into the Willamette River, Durken said in a statement.

The 65-year-old Alder Pump Station at Southeast Alder Street and Southeast Water Avenue, where the discharge occurred, is reportedly slated for improvements that will take about two years to complete, and will "improve reliability and increase pumping capacity, which will help prevent sewage releases into buildings and streets and combined sewage and stormwater overflows to the Willamette River," according to information on the project's website.

The same pump station overflowed again around 2:30 p.m. and again just after 3 p.m. The two afternoon overflows, Durken said, lasted roughly 30 minutes altogether.

Durken said a previous project completed in 2011, called the Big Pipe project, has reduced combined sewer overflows to the Willamette River by 94 percent, with overflows previously occurring 50 times per year on average. That number has been reduced to about five overflow incidents per year on average, with four overflows occurring each winter and one taking place every three summers.

Image: Jouregio via Pixabay.com