The new Brightwater Wastewater Treatment Plant in Seattle, Wash., goes on-line in 2010, but King County residents already enjoy its surrounding property.
The latest of three wastewater plants to serve about 1.4 million people in the Puget Sound area, Brightwater will also process wastewater from parts of Snohomish and Pierce counties. The plant will open with a capacity of 36 mgd. By 2040, that will increase to 54 mgd.
The entire 70-acre site is relatively flat. Treatment and support facilities cover 43 acres, and the rest is allocated for stormwater treatment, open space, wildlife habitat and wetlands. The design integrates landscape, architecture, wildlife habitat, engineering, art and education. Hargreaves & Associates of San Francisco was the designer.
Reducing pollution
The Brightwater plant and its landscape design solve many problems, including persistent stormwater runoff through nearby auto salvage yards. For years, the polluted surface runoff poured into a local stream, destroying native salmon habitat.
Hargreaves designed surface systems that stopped flooding across Route 9 from the plant. During construction, that water is being pumped to a 40-acre section that is being restored to semi-wilderness conditions and will be managed as natural habitat.
The water is pumped through temporary sprayers in the forested area to help irrigate. After construction, it will flow by gravity to detention ponds between plant buildings and the roadway.
Soil excavated or moved during plant construction was pushed to the front of the buildings and shaped into natural-looking landforms, which then were landscaped to create a buffer between the plant and the road.
Intentional involvement
Nearly two dozen agencies, including the U.S. Army Corps of Engineers, the state Department of Environmental Protection, the state Department of Fisheries and Wildlife, and eight local jurisdictions were involved in reviewing or permitting of the project, says Michael Popiwny, architectural design and mitigation manager for the project.
“Regulations haven’t been out of the ordinary, but our response has been,” he says. “We went out of our way to create this facility as a community amenity. We’ve certainly exceeded minimum requirements.
“It was more about meeting our commitment to the community. We decided right away that we would rather spend the money to do proper environmental mitigation than spend it trying to fight the public on less responsible tactics. We reserved 10 percent of our budget for mitigation development.”
The North 40
The highly mitigated and restored area on the north end of the grounds is a showcase for the plant. The natural stream there had been reduced over the years to little more than a ditch running through canary grass. The channel was relocated and widened to make it a full stream again. Engineers employed weirs and daylighted part of the waterway that had run through a pipe beneath a parking lot.
They then created natural habitat by placing tree root wads alongside the stream bank, some reaching into the water. These will provide snags ideal for breeding areas. Two large ponds were added, the stream system was lengthened, and the stream bank reforested into a buffer zone.
All this provides a natural habitat for northwest salmon. To enable easier spawning migration, the project includes a series of pools and weirs that allow grade change, in effect creating a natural fish ladder. An amphibian shelf and ladder encourages breeding of the Pacific salamander and native toads.
Associated species come along with healthy salmon habitat. Red-tailed hawks, bald eagles, bobcat, deer and coyote are all expected to appear as the area settles into natural rhythms. A great horned owl, normally a fairly secretive bird, raised a family in a tree near the stream this year.
The Field House, a small, arched building with a series of roll-up glass doors on the front, provides about 1,200 square feet of covered outdoor work and discussion area for classes and tour groups. Solar panels on its sloped roof generate electricity. A cistern catches roof rain runoff to water the facility’s test gardens.
Environmental education
An elevated boardwalk winds through the forested wetland of the North 40, allowing visitors to look down into the ponds. It is part of a managed trail system marked with interpretive signage.
The boardwalk leads back to the Environmental Education Center in front of the facility’s administration building near the treatment plant. The center is staffed by people drawn from existing county staff, such as educators for tours at the district’s West Point treatment plant and school outreach workers.
County landscape staff, projected to be two full-timers, plus two or three summer helpers, will maintain the open space surrounding the whole facility. The North 40 will be allowed to evolve naturally. Grounds crews will clean up trash and control invasive species. They will remove fallen trees only if they block trails.
Buildings are decorated with local artists’ works acquired through the county’s One Percent for Art Program, which sets aside 1 percent of funding for most county capital improvement projects for public art.
Good relations
King County already sees public relations benefits from the project. Officials are discussing with the University of Washington how the school might use the habitat area and environmental center for research, outreach and student education.
“Just by having what will become a multi-use environmental education and community meeting facility, we believe Brightwater will become a hub of our interaction with the community,” says Popiwny.
Popiwny believes public goodwill helped the project proceed more quickly and saved money by avoiding delays. He also believes the process offers a blueprint for other treatment plants seeking to expand.
“All utilities provide a framework for economic growth, so work with your local and regional communities,” he says. “Involve them in your decision-making process. Try to be visionary: You really want to look at the big picture.
“Seek the best long-term regional solution and work to implement that, as opposed to a limited, narrow, meet-today’s-need response. You’ll end up with a positive result that will be a building block for your community.”
