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It’s the North End creek that’s been paved over, concreted over, made to flow through buried pipe and literally moved and straightened to make room for development.

There have been improvements to Thornton Creek such as daylighting portions, but now comes the study that says parts of the stream, and the creeks that feed into it, are so full of human fecal bacteria that the public is being warned to stay out.

In some instances, the levels of E. coli have been nearly 50 times above the state and federal criteria, says Jonathan Frodge, the Seattle Public Utilities stormwater scientist who led a two-year study of the watershed. “If you do touch the water in the creek, wash with soap and water,” he says.

The Centers for Disease Control and Prevention says some kinds of E. coli can cause diarrhea, and serious illnesses.

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To Ruth Williams, president of the Thornton Creek Alliance — composed of 115 neighbors who work on projects such as pulling out invasive weeds — this is just the latest indignity that this stream has faced.

“It’s been abused,” she says, simply.

As its wends its way 15 miles from Shoreline to Lake City and finally empties into Lake Washington at Matthews Beach Park, the creek goes through over 700 backyards and past what in 2000, the utility estimated were homes to 70,000 to 80,000 people.

Frodge says the public is being asked to help out with the smell test.

“If you’re out there walking, your nose is as trained as anyone’s,” he says.

Sewer smell is sewer smell.

Frodge says people can email him at

The utility now has to figure out where that human waste is coming from, he says.

It could be any number of things: leaky sewers, or sewer pipes a contractor accidentally connected to a storm drain instead of a sanitary drain, or RV owners illegally dumping their sewage, or the homeless who camp out along the creek.

Inspectors now will try and find the source by using everything from TV cameras snaked into sewer lines, to using dye or smoke in the pipes to see where they drift to, he says.

Besides using the smell test, the public can contact SPU if they notice well, toilet paper, along the creek. Or soil that no longer is brown but has turned orange-ish as the feces oxidizes.

Frodge says new testing procedures of selected water samples — the study didn’t have enough funds to test every sample — showed the feces was positive for humans.

At Matthews Beach, the creek empties about the equivalent of a block south of the swimming area, and its contents drift away.

The county does regular monitoring of all its beaches, and right now, Matthews Beach is at “low concern — safe for swimming.”

Signs are being printed to be placed along the creek, to join other signs already there warning about “Bacteria!”

Basically, the utility says, people should stay out of all urban creeks.

On Thursday, in areas along the creek made narrow to accommodate a parking lot, things looked very different from the memories that the late Dorothea Nordstrand wrote about Thornton Creek in the 1930s.

The full essay is found at

“It was a lovely, wooded area, the first such just a few blocks north of our Green Lake community. A pathway ran beside it. There was a canopy of trees, and mounds of tender undergrowth, which ran down to the mossy banks. There were fish, and lots of wildlife. Many wild birds, the darting kingfishers, and an occasional Great Blue Heron to wade in the clear shallows. Squirrels, muskrats, raccoons, and mink lived there,” she wrote.

“Thornton Creek was a lovely, green place. Many neighborhood folks fished there, and had picnics on its banks. It’s pleasant to remember.”

Erik Lacitis: 206-464-2237 or

Seattle Times news researcher Gene Balk contributed to this report.

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