Heavy rains and power bump cause sewage overflow and local flooding problems in Washington County

Sewage overflow caused by power bump in Tigard

Heavy rains and a series of “power bumps” at Clean Water Services’ Durham Advanced Wastewater Treatment Facility in Tigard have disabled a large sewage pump, causing the overflow of approximately 4000-5000 gallons per minute of raw sewage into the Tualatin River. Area residents and pets are advised to avoid contact with flood water in lower Fanno Creek and the Tualatin River downstream of Tigard’s Cook Park.

The Durham Facility’s influent pump station experienced a series of power bumps Monday afternoon damaging one of the station’s large pumps. Four smaller pumps in the station are operating at capacity, but cannot keep up with increased flows. The influent pump station lifts sewage from the collection systems into the wastewater treatment facility.

The Durham Facility is providing full treatment for 60 million gallons a day of the rain-swollen flows, but estimates 4000-5000 gallons a minute of raw sewage has been overflowing into the Tualatin River from a diversion structure near the plant since Tuesday morning. There have also been reports of sewage overflowing from manholes near Fanno Creek near the Durham Facility but investigation by District staff reports no on-going overflow at that location.

Clean Water Services has posted warning signs in the areas and is taking water samples upstream and downstream of the overflow. Signs will be removed when water samples show no evidence of sewage.

Raw sewage that is overflowing is highly diluted by rainwater which helps reduce the public health risks, but bacteria are still present.

Clean Water Services’ Rock Creek, Hillsboro and Forest Grove wastewater treatment facilities are providing full treatment of the rain-swollen flows. Crews are also monitoring 41 sewage pump stations, sewer pipes and manholes to watch for overflows, but no other spills have been reported from the collection system.
The public is advised to call Clean Water Services or their city to report dislodged manhole lids or sewage bubbling from manholes. The public should not try to replace the lids.

Surface Water Flooding

Clean Water Services have been responding to local flooding problems in low lying areas of urban Washington County since late Sunday night. Crews have been working to clear leaf-clogged stormwater grates, inspect and clear culverts and monitor known problem areas to ensure the public drainage system is operating properly.
The public can help relieve localized flooding problems by keeping stormwater grates clear of leaves and debris and keeping yard debris and leaf piles away from drainage ditches and streams so that rising water does not carry the material downstream and block a culvert.
Self-serve sandbagging stations are located below. Please call ahead to confirm hours of operation. The sand is for flooding prevention use only. Bring your own shovel and bags.

• City of Beaverton 9600 SW Allen Boulevard (503) 526-2220
• City of Cornelius 1300 South Kodiak Circle (503) 357-3011
• City of Tigard, 8777 SW Burnham Rd. across from Tigard Water District office (503) 639-4171
• Clean Water Services Field Operations 2025 SW Merlo Court, Beaverton (503) 547-8100
• City of Hillsboro NE 28th at Sports Complex (503) 615-6509
• City of Tualatin 10699 SW Herman (503) 692-2000
• City of Forest Grove Fire & Rescue 1919 Ash St. (503) 992-3240
• Tualatin Valley Fire & Rescue 3608 SW 209th Ave, Aloha (503) 649-8577

Clean Water Services is the sanitary sewer and surface water management utility for nearly 500,000 customers in urban Washington County and small portions of Multnomah County, Clackamas County, Lake Oswego, and Portland. Clean Water Services operates four wastewater treatment plants, constructs and maintains flood management and water quality projects and manages flow in the Tualatin River to improve water quality and protect fish habitat. Although Clean Water Services maintains a close working relationship with Washington County government, it is a separately managed and financed public utility.

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