Operating water quality programs

In 1972, the U.S. Congress passes sweeping amendments to the federal Water Pollution Control Act that greatly affected Metro's water quality program. The bill, know as Public Law 92-600 required all municipal sewage treatment agencies to achieve secondary wastewater treatment by 1977.

In 1974, Gov. Dan Evans chose Metro as the agency responsible for areawide water quality planning for the Green and Cedar River basins. Metro spent most of that year evaluating the agency's policy on treatment levels. In the fall, the Metro Council endorsed a six-point Puget Sound water-quality program that included a decision to provide secondary treatment.

Secondary treatment

In 1977, President Jimmy Carter signed into law a measure allowing municipal discharges to apply for a waiver of the secondary wastewater-treatment requirement if they could prove that discharge of primary effluent was not harmful. In 1978, Metro applied for waivers to continue primary treatment at its four Puget Sound plants. The U.S. Environmental Protection Agency (EPA) tentatively approved the waiver for the West Point plant in 1981. The state Department of Ecology later agreed with EPA's decision.

Clean Water Act -- Environmental Protection Agency (external link)

By 1984, however, much public attention focused on Puget Sound water quality and pollution issues, particular toxicant contamination. Scientists conducted studies of Puget Sound to determine if secondary treatment would be beneficial. The research found increasing levels of toxic materials in the waste stream and in marine life. The studies concluded that secondary treatment, with pretreatment of industrial waste before discharge to sewers, would reduce the levels of toxins in Puget Sound.

EPA and the Ecology Department, after reconsidering the treatment level issue, announced that all treatment plants discharging directly into Puget Sound must provide secondary treatment.

The Ecology Department issued a compliance order that required planning for secondary treatment be completed and design work begun by July 31, 1986. The compliance order required Metro to have secondary facilities operating by early 1991.

In July 1986, the Metro Council adopted a plan to upgrade its Puget Sound plants to secondary treatment. Under the plan, Metro would upgrade its West Point plant to secondary and convert its Alki and Carkeek plants to treat stormwater flows only. The Renton plant has provided secondary treatment since in opened in 1965. The council also approved a plan to demolish the Richmond Beach plant and exchange sewage flows with the City of Edmonds.

In addition, Metro adopted a program to control combined sewer overflows further and achieve a 75 percent reduction in overflows during a 20-year-period to fulfill new state Ecology Department requirements.

West Point Treatment Plant, Seattle, Washington (Photo taken in 2002)

In converting West Point from primary to secondary treatment, finished in 1996 (external link) , Metro reduced the plant size and limited shoreline facilities while improving public access to water and screening the plant from shoreline view.

Toxicant pretreatment

In 1984, Metro finished a five-year study of toxic chemicals in Puget Sound and other regional waters. The Toxicant Pretreatment Planning Study also identified toxicants in Metro's wastewater collection and treatment system. Metro has carrying out several study recommendations, including:

• new industrial pretreatment standards
• increased industrial waste monitoring
• a program of recovering costs from industry for monitoring and regulating industrial wastes.
• continued support for programs that control toxicant discharge at its source, such as industrial pretreatment, water supply corrosion control, and proper household hazardous waste disposal.

In 1987, Metro issued Priorities for Water Quality , an update of the area plan for the Seattle-King County metropolitan region. The update concluded that surface water management and toxicant control deserve further attention.

Biosolids recycling

Biosolids Recycling Program

Biosolids, a nutrient-rich semisolid byproduct of wastewater treatment, became a point of interest for the Metro Council in 1983, when it approved a long-range plan for managing biosolids.

The plan identified three land-application uses--silviculture, soil improvement and reclamation, and composting-for Metro biosolids through the year 2000. Since 1972, Metro had been committed to recycling biosolids, instead of burning it or taking it to a landfill--as done by some other sewer agencies.

The agency sold some biosolids to private companies for creating a compost soil amendment, and it used some in special parks projects to enrich infertile soil. Metro also contracted with the University of Washington to test use of the biosolids on trees at the university's Pack Forest site.

Expanding on the successful silviculture idea, Metro in 1987 began biosolids application on land owned by the Weyerhaeuser Co. and other forest-products companies.

In recognition of the agency's successful biosolids-recycling operation, in October 1988 the U.S. EPA gave Metro an award for operating the nation's best beneficial biosolids-use program. EPA found that Metro biosolids met federal standards for soil enrichment.

And thanks to the agency's industrial-pretreatment and hazardous-waste education programs, the amount of metals and pathogens in biosolids was reduced so significantly that the federal government approved its use for agricultural crops.

Metro also worked with the Northwest Biosolids Management Association (external link) and the national Water Environment Federation (external link) to provide information to the public about biosolids recycling.

Because of those efforts, Metro biosolids had achieved public acceptance by 1995. Biosolids continues to be used for gardening compost and on Western Washington forests. A major market is in Eastern Washington, where knowledgeable dryland wheat farmers and hops ranchers will take all the biosolids available.

Another aspect of biosolids production also contributes to Metro's recycling efforts. Methane gas produced during the solids digestion process at Metro's West Point plant is used to power the plant's equipment and generate electricity for the City of Seattle power grid. Most methane produced at the South plant in Renton is scrubbed and sold as natural gas to Puget Sound Energy.