For every human action, it seems, there is an equal and opposite reaction when it comes to affecting water quality. Urban streams such as...

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For every human action, it seems, there is an equal and opposite reaction when it comes to affecting water quality.

Urban streams such as those in the Issaquah Creek Basin tell the story of the push-pull dynamic between humans and nature, ecologists say.

The 61-square-mile area is the target of an upcoming state Department of Ecology plan to improve the well-being of its waters, which contain high levels of disease-causing bacteria and other contaminants. The department’s report on how to reduce the pollutants is expected to be released by the end of May.

Everything people do — from washing cars to littering the highway, even taking birth-control pills — eventually makes its way downstream, said Dave Garland, Ecology’s water-quality watershed-unit supervisor.

“This isn’t to lay a big guilt trip on people, but to try to get them to be more conscious and be willing to alter their practices to improve water quality,” he said.

Washing a car in the driveway, for instance, reduces oxygen levels in streams over time and hurts salmon habitat. Soapy runoff empties into storm drains that flow directly into creeks — unfiltered. Water-quality officials say a better alternative is to use car washes, where the dirty water is filtered.

Public gathering

To increase awareness of water quality and fish and wildlife habitat, the Issaquah Basin Action Team — a partnership of representatives from Issaquah, King County, the state Department of Ecology, Washington State Parks, Mountains to Sound Greenway Trust and Issaquah Environmental Council — is holding a potluck event May 11 from 6-9 p.m. at the King County Library System Service Center, 960 Newport Way S.W., in Issaquah. For more information, contact Mary Maier at 206-296-1914 or

This also happens with lawn fertilizers carrying chemical pollutants, said Mary Maier, Issaquah and Bear Creek basin steward for the King County Department of Natural Resources & Parks.

“We’re making our lawns nice and green, but the bottom line is we have an issue with declining salmon, and efforts need to be made to help restore the health of the basin,” Maier said.

The Issaquah Creek Basin — which encompasses Issaquah and Tibbetts creeks and their tributaries that flow into Lake Sammamish — contains excess amounts of fecal coliform bacteria, which live in the intestinal tracts of humans and animals. The bacteria carry pathogens that can cause gastrointestinal disorders, ear infections and skin disorders, said Anne Dettelbach, an Ecology Department water-cleanup coordinator.

This contamination originates from leaking septic tanks and waste runoff from animals and landfills, according to a 2004 state report on the basin.

Another way bacteria get into streams is when highway litter attracts rodents and birds that excrete waste, adding to road runoff.

And hormones from birth-control pills wind up in human waste that can leak out of aging septic tanks.

Water-quality data of Issaquah Creek over the past 15 years show that during the summer, fecal coliform bacteria are nearly 10 times higher in some areas of the creek than the state standard, Dettelbach said.

The situation is not unique to Issaquah, she said.

“This is a problem that’s everywhere, and it’s a problem that urban areas are going to face for a long time,” she said. “It’s really going to take some action on the part of a lot of people to correct.”

Sonia Krishnan: 206-515-5546 or