Combined Sewer Overflows

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Increased population on the north Portland Peninsula added to environmental pressures on the Columbia Slough, increasing sewer flows. By the 1970s, combined industrial contaminants, storm water, and human sewage sometimes backed up into residential areas on the slough. A letter to Governor Tom McCall from a city resident reveals the frustration felt by some north Portlanders:

Since last June there have been three times when filthy and stinking SEWER WATER has backed up into basements of residents. . . In September we suffered 6 inches of foul stinking filthy sewer water covering our entire basement floor. Petitions were signed by more than 600 people urging the City to DO something — they did nothing!! Then Jan 22nd, just last month, we this time had 12 inches of the same filth in our basement. . . . NOW, WE DEMAND THAT SOMETHING BE DONE ABOUT IT!! Loren C. Mabee, north Portland resident, 1970

The Portland sewage system handled storm waters and sanitary waste. In 1985, the Willamette/Slough system contained 56 pipes and concrete bunkers discharging raw sewage, industrial wastes, and toxic pollutants from city streets, into the urban waterways. Despite complaints from citizens, in 1990 the Combined Sewer Overflows (CSOs) still poured billions of gallons of rainwater runoff and sewage annually into the Willamette River and the Columbia Slough.

Excessive bacteria endangered wildlife and humans, prompting environmentalists to place warning signs on the slough. In 1991 Northwest Environmental Advocates (NWEA) sued the city of Portland to end the discharge of raw sewage in the Willamette River and the Columbia Slough. The NWEA lawsuit resulted in an agreement between the city and the Department of Environmental Quality to clean up CSOs, and more importantly, set a precedent for citizen action in enforcing standards set by the Clean Water Act.

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