September 30, 2013
For more information contact Linc Mann, 503-823-5328
City recommends caution for Willamette River use
Weekend rainstorms caused Portland’s combined sewer system to overflow to the Willamette River. There were weekend combined sewer overflows (CSOs) from the following nine outfall pipes:
Willamette River West Side
- SW Carolina (outfall 3 just north of Willamette Park)
- SW Sheridan (outfall 7 under the Marquam Bridge)
- SW Ankeny (outfall 9 under the Burnside Bridge)
- NW Nicolai (outfall 15 at Terminal 1 north of the Fremont Bridge)
Willamette River East Side
- SE Taggart (outfall 30 just north of the Ross Island Bridge)
- SE Alder (outfall 36 just north of the Morrison Bridge)
- N River (outfall 41 near Memorial Coliseum)
- N Beech (outfall 46 near Ash Grove Cement)
- Swan Island (outfall 47 on Swan Island)
The public should avoid contact with the river downstream of the Ross Island Bridge through Wednesday night, 48 hours after the end of the CSO event. It is especially important to avoid recreational activities, such as jet skiing or swimming, during which water could be swallowed. CSOs are contaminated with bacteria from untreated sewage. Environmental Services recommends these precautions to protect public health. People who fish during or soon after a CSO event should wash their hands following contact with river water. Those who choose to eat fish caught in the Willamette River during or soon after a CSO event should cook the fish thoroughly to kill bacteria.
Portland’s combined sewer system carries sewage and stormwater runoff in the same pipes. During very heavy rainstorms, the increased stormwater runoff can cause combined sewers to overflow into the Willamette River.
In December 2011, Portland completed a 20-year program that improved the sewer system and reduced Willamette River CSO volume by 94%. The program reduced CSO events from an average of 50 per year to no more thant four CSO events per winter and one every third summer.
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.