(March 23, 2026) – On Sunday morning, March 22, around 8:00 a.m., staff responded to a sanitary sewer overflow at the OLWS wastewater treatment plant (13750 Southeast Renton Avenue).

One of the plant’s digesters (equipment that breaks down sewage for reuse as biosolids) overflowed, causing a spill. Most of the sewage was contained on plant grounds, but some reached an adjacent area beneath the wooden railroad trestle near the Lake Oswego Railroad Bridge. It is estimated that fewer than 1,000 gallons were spilled, and none is believed to have reached the Willamette River.

Oak Lodge staff cleaned up the spill using a vactor truck and applied lime to the affected area.

Because the spill occurred on private property with no public access, there isn't direct risk to the public. The area has been taped off as an added precaution.

The Oregon Department of Environmental Quality (DEQ) and partner agencies connected to the Willamette River have been notified.

Questions? Please contact us at info@olws.org or call (503) 654-7765.