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Water Quality

Wastewater Overflows

City of Lake Oswego containing overflow

If you suspect a wastewater overflow call:

City of Lake Oswego Operations Division at 503-635-0280 during working hours Monday-Friday, or after hours LOCOM at 503-635-0238.
 

City of Lake Oswego Sewer Overflows

During recent winter storms, the City of Lake Oswego experienced limited instances of sanitary sewer overflows.  Unusually heavy sustained rains led to infiltration of groundwater into sanitary sewer lines exceeding their available capacity.

The Oregon Department of Environmental Quality advises that residents who plan to use the lake for in-water recreation this winter should take the same precautions that they would normally take.  While the diluted flows may have carried some bacteria, it is reasonable to assume that it has since dissipated through further dilution and cooler temperatures.  It is generally good advice to avoid ingesting the water and shower/clean thoroughly after being in the lake.

Unusually heavy rainfall will certainly challenge the system each winter, and there are continuous maintenance efforts underway to address capacity and durability of our infrastructure through a combination of temporary measures, ongoing maintenance, and long-term improvements.
 

Overflow Response Plan

To reduce the frequency, duration and amount of sewer overflows the City developed an Overflow Response Plan (ORP) to protect public health.  

What you can expect to happen during heavy rains:

  • Operations Division staff will be activated to immediately deploy to the location of the first point of overflow in the system.
  • Nearby points of inflow to the stormwater system will be blocked and a containment area set up to vacuum wastewater overflow before it reaches the lake or storm system.
  • Access to any potential areas of overflow will be restricted to ensure public safety.
  • Operations will notify property owners, business owners and residents of the overflow condition with either flyers or the City’s CodeRed emergency calling system.
  • In the event of a large spill that can not be contained, wastewater may flow into the lake at different locations.  Please do not come into contact with any canal or lake waters until you are notified that it is safe to do so.  Please prevent your pets from swimming in or drinking from these water bodies.

The city’s goal is to prevent spills whenever possible. If you see discolored water coming from a manhole, please call the Operations Division (503) 635-0280 during business hours or LOCOM (503) 635-0238 for after hours response.