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Communities | Environment

State-of-the-Art Wastewater Plant to Open In Washington

WOODINVILLE, Wash. — Workers at the new Brightwater treatment plant want everyone to know that toilets aren’t magic — they don’t make waste disappear.

“Everything you flush ends up here,” says Annie Kolb-Nelson, spokeswoman for the King County Wastewater Treatment Division.

Or will end up here starting in next month.

Here is the new wastewater treatment facility built on 114 acres just north of Woodinville.

After five years of construction, the treatment plant will start operating in August and will be able to treat an average of 36 million gallons of wastewater per day. It can expand to treat 131 million gallons a day during peak periods.

Once online, the plant will serve 14 cities and sewer districts in south Snohomish and north King counties. The facility was built because the Seattle metropolitan area grew so quickly in the 1990s that the state’s two largest treatment plants, West Point Treatment Plant in Seattle’s Magnolia neighborhood and the South Wastewater Treatment Plant in Renton, were running out of room. Construction of Brightwater started in 2006 and once the $1.8 billion facility is complete, it will ease the pressure on the region’s other plants.

Brightwater will be the largest wastewater treatment plant in North America to use membrane bioreactor technology, the latest in state-of-the-art wastewater treatment method.

Here’s how it works, according to plant officials:

  • Water passes through a series of vats that are filled with millions of long straws. These straws look like long strands of spaghetti, except they’re plastic and hollow.

  • Clean water particles are sucked through tiny pores in the walls of the strands. Since the pores are only 0.04 microns in size, they allow water molecules to pass through, leaving bacteria, viruses and pollutants on the other side.

  • What’s sucked through is practically drinking water.

“The membrane straws really are the workhorses of the treatment process. This technology produces very very clean wastewater, which we discharge into Puget Sound,” said Gunars Sreibers, project manager for the Brightwater construction project.

About 11 million gallons a day of the treated water will be reclaimed for use in industrial processes and for irrigation of crops, gardens and landscaping.

Tour Brightwater

The public is invited to the grand opening of the Brightwater plant in Woodinville on Saturday, Sept. 24. Click here for details.

But the plant isn’t equipped to treat everything.

“These plants haven’t been designed to remove pharmaceuticals. People shouldn’t be flushing pharmaceuticals down the toilet,” Sreibers said. “They should be taking them back to pharmacies to deal with.”

The other unique aspect of this plant is the fact that It is guaranteed to be odorless — none of the sewage smells are allowed to leave the site.

“We have a three-stage odor control system — biological, chemical and carbon absorption,” Sreibers said. Any portion of the process where odors are generated is covered in order to contain odors. The buildings were also fitted with vacuums, so that the air is being sucked into the building rather than being allowed to escape into the atmosphere.

In short, neighbors shouldn’t even be able to get a whiff of Brightwater, Kolb-Nelson said.

They may also have a difficult time seeing the plant because it’s surrounded by park-like green space with wetlands and hiking trails. The plant covers about 43 acres, while the other 71 acres are dedicated to stormwater treatment, wildlife habitat and wetlands.

To see King County’s photos of the construction, click here.

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