Reclaimed water adds life to Chinook Bend wetland

A new treatment plant built to protect water quality and support city of Carnation’s planned economic development is helping to preserve fish and wildlife habitat at the Chinook Bend Natural Area.

Last week, county employees turned the valve that directed the first flows of Class A reclaimed water produced at the Carnation Treatment Plant into a 59-acre wetland about a mile from the facility. The wetland will serve as the primary discharge point for the state-of-the-art treatment plant that began operating in May to replace failing septic systems deemed hazardous to human and environmental health.

“This project is a textbook example of how modern wastewater treatment facilities can be an asset to communities,” said King County Executive Ron Sims. “Sustainable design, advanced technology and progressive water resource management that incorporates innovative uses for reclaimed water will help ensure the economic and environmental future of the Carnation community.”

The wetland enhancement includes an additional four acres of habitat, new water control structures, a daylighted creek, and the removal of an old, environmentally damaging culvert and drainage system. Volunteers have planted more than 15,000 trees and native shrubs.

In 2000, Nestlé USA donated the Chinook Bend land to the county to develop as a habitat preservation area. While planning was under way to build a new treatment plant, King County partnered with the nonprofit group Ducks Unlimited on the wetland project design, which took advantage of their expertise in habitat conservation and helped reduce overall costs while keeping the project on schedule. The Snoqualmie Tribe, community members, elected officials and Carnation staff were also important stakeholders during project design.

“We’ve shown how a small city can come up with solutions to the problem of inadequate infrastructure,” said City Manager Candice Bock. “The new treatment system is a welcome amenity, protecting public health as well as our beloved Snoqualmie River and other natural resources at the same time.”

“The wetland enhancement at Chinook Bend was a great collaborative effort,” said Daniel Golner, manager of conservation programs for Ducks Unlimited. “We are able to use reclaimed water as an additional source of water for moist soil management of the site, which allows for control of invasive reed canary grass and provides wetland habitat for fish, waterfowl and a host of other wetland dependent species.”

The Carnation Treatment Plant recently earned the WateReuse Association’s Small Project of the Year Award in recognition of its innovative use of reclaimed water to enhance wetlands and preserve local habitat.

The plant uses an advanced technology called a membrane bioreactor (MBR) system instead of the large round settling tanks used in conventional plants, treating wastewater to such high levels that it can be safely used for almost any use except drinking.

Before the valve-turning, the plant had been temporarily discharging water to an outfall in the Snoqualmie River to ensure water quality met permit standards. Regular monitoring conducted as part of the plant’s normal operation will ensure the reclaimed water it produces is safe for the wetland’s plants, fish and animals. The river outfall will continue to serve as an emergency discharge option.

The new treatment plant currently serves about 2,000 people in Carnation’s urban growth area. At design capacity, the plant is expected to treat about 480,000 gallons of wastewater a day.

The $23 million wastewater treatment system project took less than two years to complete. Federal, state and county and state grant funding covered some of the project construction costs.

More information is available at http://www.kingcounty.gov/environment/wtd/About/System/Carnation.aspx.

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Note to editors and reporters: Visit the WTD Newsroom, a portal to information for the news media about the Wastewater Treatment Division, King County Department of Natural Resources and Parks: http://www.kingcounty.gov/environment/wtd/Newsroom.aspx

Related Information

Carnation Wastewater Treatment Plant

King County Wastewater Treatment Division