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The City of Portland, Oregon

Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

MAILING ADDRESS: 1120 SW 5th Ave, Room 1000, Portland, OR 97204

More Contact Info

Check the Rec: Willamette River Recreation Index

The 2019 summer weekly testing season begins in time for Memorial Day weekend.  The summer season's first water samples will be taken on Wednesday, May 22 and results posted Friday, May 24.

Overview: Thanks to ratepayers’ investment in the $1.4 billion Big Pipe project – the largest public works project in Portland history that was completed in 2011 – almost all combined sewer overflows (CSOs)to the Willamette River have been eliminated. With that drop in sewage exposure comes a drop in E. coli bacteria – an indicator of fecal matter and the single biggest health concern for swimming and other direct-contact recreation, according to the state Department of Environmental Quality.

Other E. coli sources include poop from wildlife and pets (thank you for picking up after your dog). Because of the public’s interest in recreation on the Willamette River, Environmental Services tests for bacteria weekly during the summer – it’s one way you can be assured of bacteria levels and see and experience the results of your investment in the Big Pipe project. Find out test results by clicking on the map or the list of sites below. (Results will begin to be posted May 24, 2019).

Sellwood Riverfront Park Dock Sellwood Riverfront Park Dock Willamette Park Boat Launch Willamette Park Boat Launch Portland Boathouse Dock Portland Boathouse Dock Riverplace Marina Boat Dock Riverplace Marina Boat Dock Cathedral Park Boat Launch Cathedral Park Boat Launch

Summer weekly testing

River sampling occurs from late May to late September. Samples are taken at five popular locations on Wednesdays, and results are posted on Fridays.

Year-round monthly testing

In addition to summer testing, Environmental Services collects water samples monthly at three locations to track long-term water quality trends.

Stay safe!

Keep in mind many factors affect your safety on the river, including temperature, currents, and debris in the river as well as your skills and ability in the water. Remember, cold water is healthy for fish, but it can be uncomfortable and even unsafe for people. Know the water, know your abilities, and stay safe while enjoying the river.

Sewage advisories

Be advised, combined sewer overflows (CSOs) are rare, thanks to the Big Pipe Project, but may still occur during periods of exceptionally heavy rain. In the unlikely event of an overflow, Environmental Services will issue a CSO advisory to the news media, place signs along the river, and post the advisory information at the top of this page and on the home page. During CSOs, the public is advised to avoid contact with the river for 48 hours due to increased bacteria.


Diane Dulken at or 503-823-5328.

Learn More About Willamette River Health

Reducing sewage overflows is one way Environmental Services is working for a healthier river. Environmental Services also is restoring habitat, preventing pollution through a variety of programs, and collaborating with other parties to clean up the Portland Harbor Superfund site. Here you can find additional resources and answers to frequently asked questions.

2017 Test Results

Environmental Services 2017 results of weekly bacteria level sampling in the Willamette River