Human waste confirmed in Seattle's Thornton Creek

by: Chris Legeros Updated:

SEATTLE - Signs warning people to stay out of the water will soon be posted along Thornton Creek.

 A study by Seattle Public Utilities has confirmed that e. coli bacteria from humans is entering the watershed from a number of locations.  That sewage brings with it an increased risk of skin rashes and stomach problems if someone comes in contact with the water.

Ruth Williams lives along the creek and she's a member of the Thornton Creek Alliance.

“We knew that the creek was pretty polluted and the water quality has been poor for several decades. It hasn't really improved. We didn't know how bad it is,” said Williams.

The creek and its tributaries run roughly 15 miles from Shoreline to Matthews Beach in Seattle.

Thornton Creek cuts through 700 backyards.  By taking water samples, stormwater scientist Jonathan Frodge has been able to map the areas where there is the most fecal pollution. One spot is east of Northgate, and a couple of others are in Lake City.

The city will use this information to narrow its search for the sources of human waste.

“We’re going to look in an area of maybe 100 to 200 acres instead of 7,000 acres for where that potential source is coming from,” Frodge said.

 Sources could include leaking sewer pipes or homeless camps near the creek. RV owners may be dumping their waste in storm drains in the watershed. Once the city locates where sewage is coming from, it will work to control or eliminate the pollution.