Sanitary Sewage Release Advisory: (this is not a combined sewer overflow [CSO] advisory)

(February 16, 2017) - Sewer maintenance crews responded this afternoon to two reports of sewage overflowing from two manholes in Southwest Portland and towards Fanno Creek.

Crews stopped a release of unknown quantity at SW 25th Avenue and Beaverton-Hillsdale Highway, and a release estimated to be about 900 gallons from a manhole at SW Sunset Boulevard and SW 26th Avenue.

Both were weather-related and stopped within an hour. During heavy rains, rainwater can seep into sewer systems, causing pipes to exceed their capacity. The mix of stormwater and sewage then releases via a manhole.

Environmental Services crews posted warning signs in the area. In addition, as a precaution, the public is advised to avoid contact with Fanno Creek for at least 48 hours because of the possibility of increased bacteria in the water.

Sewage overflows commonly are caused by blockages such as grease, tree roots or debris. In Southwest Portland, heavy rains can cause stormwater to seep into the sewer system and overwhelm the capacity of pipes. Over one-third of Portland’s more than 2,500 miles of sewer pipes are over 80 years old.

The Bureau of Environmental Services provides city residents with programs to protect water quality and public health, including wastewater collection and treatment, sewer construction and maintenance, stormwater management, and stream and watershed restoration.