MAILING ADDRESS: 1120 SW 5th Ave, Room 1000, Portland, OR 97204
Today the Willamette River through Portland is cleaner than it's been in decades, thanks in large part to ratepayers’ investment in the Big Pipe project that dramatically reduced combined sewer overflows.
How can you be sure? We test the water. View results below or by clicking on map locations.
CSO Advisories: Be advised, even with improvements, combined sewer overflows (CSOs) may occur during periods of heavy rain. These overflows of stormwater mixed with sewage are rare. But when they occur, CSO Advisories are posted on the home page. During CSOs, the public is advised to avoid contact with the river for 48 hours due to increased bacteria.
Summer weekly testing: Environmental Services collects weekly samples from late May to October to measure for E. coli bacteria and temperature at five popular public entry points. Water samples are collected on Wednesdays and results posted by Friday morning – just in time for the weekend.
Year-round monthly testing: Environmental Services collects water samples monthly at three locations on the Willamette River to track long-term water quality trends.
The five test sites on the map are informal but popular access points.
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.
More information about Willamette River water quality in Portland