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OperationsWater Quality

‘Tis the Season: Enjoy the Natural Beauty of Our Beaches and Waterways

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Whether you have just arrived, or you’ve lived here so long you remember a time before traffic jams, you cherish our region’s natural environment, and especially our waters. We sail, SCUBA dive, fish, paddleboard, kayak, go tidepooling, walk the beaches, or just contemplate the waves.

The good news is the beaches around Seattle’s Discovery Park remain open for recreation while we continue to restore West Point Treatment Plant. Since Feb.16, plant operators have successfully managed wastewater flows even in large storms, avoiding another emergency bypass that would result in public health warnings about contact with waters in the area.


After emergency bypasses of stormwater and sewage at West Point, people contacted us with questions about beach recreation. How will I know if a beach is closed? What is a CSO, and should I care if I’m a SCUBA diver? What do those warning signs mean? Here are some answers and resources to help you make informed choices about water recreation.

Beach closure information is posted on several online locations. Swimming beach closures appear on the Department of Ecology’s website. During the summer, King County monitors freshwater beaches and posts alerts. Washington State Department of Health posts recreational and shellfish closures.

Combined sewer overflows (CSOs) are releases of stormwater mixed with about 10 percent sewage that occur during heavy rains in older parts of Seattle. CSO’s were designed decades ago to help prevent backups into homes and businesses, but they contain enough sewage to put public health at risk.

King County and City of Seattle are aggressively working to control these overflows. Both King County and the City of Seattle are making major investments in CSO control to reduce these untreated discharges of stormwater and wastewater. You can read about King County’s Protecting Our Waters Program to learn more about our plans and projects, and find annual reports.

People can check a real-time notification page that shows when a CSO is occurring, or has happened within the last 48 hours. CSORealTime

In addition, permitted CSO locations have signage posted year-round.


CSO warning signs, like this one at North Beach, are permanent.


Sanitary sewer overflows are uncommon, unplanned and unpermitted discharges of raw sewage typically caused by equipment failures, infrastructure damage, heavy rain, , or power outages. King County routinely inspects, monitors and maintains its facilities to ensure they function properly. But occasionally, unexpected problems cause sewage overflows into local waterways.

We are committed to protecting the public when a sewage overflow happens, and have trained responders across the agency on call 24/7 to deal with sewer emergencies.


These signs indicate a sewer overflow, and are temporary

When an overflow occurs, operations staff and plant managers immediately notify health and regulatory agencies and local jurisdictions. If the overflow involves a publicly accessible area, we issue press releases, broadcast the event on social media, and post on WTD’s Incident Response web page. WTD’s Community Services go to the site to post signage and barriers to keep people away from the overflow, and may place door hangers at nearby homes and businesses. Construction managers work quickly on any necessary emergency repairs.


If the overflow gets into a waterway, the County’s  Environmental Lab takes water quality samples to test for fecal bacteria. Tests take one to two days, and results are conveyed to Public Health-Seattle & King County Water quality monitoring continues daily until Public Health approves sign removal, usually after two days of results showing bacteria at a baseline level for the waterbody.

posting-signsIf you see a warning sign near the water, it means that raw sewage has overflowed into the waterway, and you are advised to stay out of the water in the area until signs are removed. You may think that dogs can romp in the water even when people can’t, but dogs can get sick, too, and may pass an illness to humans.

As we bring West Point back online, we have also stepped up our weekly water quality monitoring. The treatment plant is currently screening garbage out of incoming wastewater, settling some solids, and disinfecting before discharging through an outfall deep in Puget Sound.  By April 30, we expect West Point to be treating most flows at a secondary treatment level.


While West Point is being restored, King County is conducting additional marine and environmental monitoring, and sharing data and findings with agencies, elected officials, groups and organizations, and the public.

Stormwater is an invisible but powerful threat to water quality. There isn’t a notification system to let people know that stormwater has caused a problem in our waterways. But heavy rains can wash chemicals from roadways and yards and bacteria from pet and wildlife waste, livestock, and leaking home sewers into waterways.

Many of us get out after being housebound and enjoy the clear air and views that often follow big storms. People here like to stroll beaches to watch storms, and some wind and wave surfers seek them.  Dog owners walk their pets day in and day out, no matter how rainy it is.  During and after heavy rains, you might want to check all your resources, including the Public Health site, before heading out to play in the water.

Enjoy our waters

People from across the nation and around the world come to King County to live, work and play. We are fortunate to have an inland sea so close to our homes, schools, and businesses. But urban areas so close to the water means that we can affect water quality, especially in large storms. We can all keep an eye on the weather and check resources to make informed choices about enjoying those waterways – and stay healthy while we do.


Paddleboarding our waters, photo courtesy of Rob Casey