News Release

For release: March 1, 2004

Lyle Christensen, DEQ Northwest Region Water Quality, 503-229-5295
Marcia Danab, DEQ Communications and Outreach, 503-229-6488
Charles Logue, Clean Water Services Technical Services Director, 503-681-3604
Mark Jockers, Clean Water Services Public Affairs Manager, 503-681-4450

DEQ Issues First in the Nation Watershed-based Permit to Clean Water Services

The Oregon Department of Environmental Quality (DEQ) has issued the first of its kind in the nation Clean Water Act integrated, municipal, watershed-based permit to Clean Water Services, a wastewater and stormwater management utility in Washington County. The permit covers four municipal advanced wastewater treatment facilities, urban storm water runoff, and allows for water quality credit trading.

The new permit combines the requirements of four previous National Pollutant Discharge Elimination System (NPDES) wastewater treatment facility permits and a major municipal storm water discharge permit into one permit with the goal of addressing water quality in a significant portion of the Tualatin River Watershed.

DEQ developed this Tualatin River Watershed-based Permit in accordance with a new U.S. Environmental Protection Agency policy that encourages regulators to issue Clean Water Act permits based on goals for an entire watershed, rather than focusing on the limits for individual facilities.

The permit:

  • includes requirements for increased stakeholder involvement in decision making and goal setting for the watershed
  • includes requirements for development of improved watershed assessment and performance measures
  • provides an opportunity to develop water quality trading and other watershed management tools
Clean Water Services is a special service district providing wastewater and surface water management services to 473,000 residents of urban Washington County. Clean Water Services operates four wastewater treatment plants that discharge into the Tualatin River and, along with Washington County, is also responsible for urban runoff associated with the municipal separate storm sewer system in the county urban areas.

While water quality in the Tualatin River has shown dramatic improvements over the last 15 years, the Tualatin River and its tributaries sometimes fail to meet state water quality standards for dissolved oxygen, bacteria, and temperature. DEQ has established Total Maximum Daily Loads (TMDLs) for the Tualatin River basin. A TMDL is a water quality plan that defines limits for the various pollutants and lists the steps needed to meet water quality standards and protect watershed health. This watershed-based permit includes requirements set out in the TMDLs.

As part of this new watershed-based permit, DEQ expects Clean Water Services to take the following actions to help lower river temperatures:

  • Augment the river's flow in the summer months with cold water from Hagg Lake
  • Plant trees along the river and its tributaries
  • Pursue opportunities for reuse of cleaned wastewater, such as irrigation of golf courses
The water quality trading provision of the new permit enables two of Clean Water Services treatment facilities that discharge to the Tualatin in the summer months to trade discharges of pollutants among each other, as long as the river exceeds water quality standards for dissolved oxygen. These facilities will work as one integrated unit rather than as two separate units. Decreased dissolved oxygen levels, which make it difficult for a stream to support aquatic life, result largely from excess nutrient loadings, including ammonia, and biological oxygen demand compounds.

For more information contact Lyle Christensen, NW Region Water Quality Program, 503-229-5295 or For more information on water quality trading contact Sonja Biorn-Hansen, DEQ Water Quality Program, 503-229-5257 or

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