Summer is almost here and for many Oregonians it’s time to get out and enjoy everything the Willamette River has to offer. On warmer days crowds are drawn to the natural beauty of the river to fish, swim, kayak, canoe or boat. Along with these great outdoor activities also comes a question—how clean is the river?
Is the water safe?
Yes, it’s safe to swim in the Willamette most of the year! Data collected over the past ten years shows that bacteria are almost always at healthy levels in Portland.
Exposure to bacteria is the greatest health concern for people swimming or enjoying other sports on the river. But bacteria levels can change quickly during heavy rains. Direct contact with high concentrations of bacteria can pose an increased risk of gastrointestinal illness as well as ear and eye infections. That’s why DEQ, the City of Portland and other groups monitor the Willamette River year-round.
What causes bacteria levels to rise?Historically, sewer overflows caused by heavy rains were a major cause of high bacteria levels in the Willamette. However, the City of Portland recently completed a major effort (the “Big Pipe project) to control this type of overflow.
Water quality improvements
Old, combined sewers used to capture rain runoff from city streets and divert this water into the sewer line. Even small amounts of rain exceeded the system’s capacity and caused raw sewage to overflow into the river. As part of its storm water program, the City of Portland has installed pipes that separate storm water from sewage and sumps. This allows runoff to percolate into the soil.
Disconnected downspouts, swales and green street projects also divert storm water from entering the sewer system. Better agricultural practices and pet waste pick-up have a helped reduce bacteria entering the river as well.
Water safety tipsIf you do swim or boat in the river here are some tips for minimizing your risk to exposure:
Avoid swimming or coming in contact with river water after a heavy rainstorm
Wash your hands and shower after swimming
Try not to swallow river water
Don’t swim in cloudy water
If you have any questions please contact DEQ Lower Willamette basin coordinator Doug Drake