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Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

1120 SW 5th Avenue, Room 1000, Portland, OR 97204

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Recent Combined Sewer Overflow (CSO) Events

December 5, 2015 - December 13, 2015

  • (nine-day storm), a period of record-breaking rainfall for Portland

  • 11 outfall pipes discharged combined sewage intermittently to the Willamette River on December 7, 8 and 9

  • Total time of discharge over the three days was 15 hours, 36 minutes

  • Total volume discharged was 638 million gallons, a higher than normal amount that reflects the very intense and long-lasting rainfall from this storm

See Storm Notes for more information on recent rain events in Portland.