Clean Water Services ’ Durham Advanced Wastewater
Treatment Facility Wins EPA Award

Washington, D.C. — October 31, 2005 — Clean Water Services’ has won top honors from the U. S. Environmental Protection Agency (EPA) for the Durham Advanced Wastewater Treatment Facility located in Tigard, Oregon. The award is the 2005 National Clean Water Act Recognition Award in the Operations and Maintenance category for large facilities with advanced treatment. The Metro Wastewater Reclamation District in Denver, Colorado tied for the award which will be presented on Monday, October 31 in Washington, D. C.

The Durham Advanced Wastewater Treatment Facility on SW 85th Avenue near Tigard High School cleans more than 20 million gallons of wastewater every day from eastern Washington County residents and businesses in Durham, King City, Sherwood, Tigard, Tualatin and parts of Beaverton and Lake Oswego. Some of the cleaned water is recycled on local golf courses, parks and athletic fields, but most is returned to the Tualatin River, providing vital clean water that improves river flow, habitat and water quality.

The Durham Facility provides advanced wastewater treatment, also known as tertiary treatment, exceeding the treatment level of 98 percent of wastewater facilities in the United States. Nutrients are removed with biological and chemical processes, followed by disinfection, filtration, and dechlorination before the cleaned water is discharged to the Tualatin River.

In addition to providing some of the most advanced wastewater treatment in the nation, the facility staff developed a phosphorus removal process so innovative and unique that it was patented in 2002. Named UFAT for Unified Fermentation and Thickening, the process is available to other municipalities for a token licensing fee to encourage biological phosphorus removal throughout the wastewater industry. By using less chemicals and reducing the volume of solids, the process saves about $110,000 per year.

The facility’s dedicated staff has made many recent changes that are saving District ratepayers hundreds of thousands of dollars. For example, new software enables staff to modify processes and reduce the use of lime for a savings of $100,000, and new centrifuges for dewatering biosolids will save about $100,000 per year.

The Durham Facility must meet federal standards before releasing water to the Tualatin River or to be recycled. By meeting nearly 1,000 strict water quality limits every year, the facility has repeatedly won the prestigious Gold Award for perfect compliance presented by the National Association of Clean Water Agencies.

Clean Water Services’ leadership and employees have worked diligently for years to cut staffing and costs, use less energy and chemicals, and devise and implement innovative technologies. They deliver the cleanest water to be recycled and returned to the Tualatin River, despite the pressures of a growing community, inflation and increasingly stringent water quality standards.

Facts about the Durham Advanced Wastewater Treatment Facility

Size of service area: 48.3 square miles

Number of people served: 140,165

Industrial users: 47 discharging more than 25,000 gallons per day (plus 108 smaller ones)

Treatment volumes in million gallons per day (mgd)

Average flow is 24.99 mgd
Peak flow is 85.25 mgd
Designed for average dry weather flow of 22.6 mgd
Designed for average wet weather flow of 29.6 mgd

Construction history:

1976 Facility began operation

1989 Upgraded two raw sewage Pumps; added bar screens and 2nd Force Main

1991 Added 3rd primary clarifier and odor control

1993 Added 3rd secondary process, 3rd tertiary process, nine effluent gravity filters and dechlorination, 4th primary clarifier; chemical feed facility and three anaerobic digesters

2001 Added 4th secondary process and primary effluent pump station; upgraded dewatering centrifuges

2002 Added 4th anaerobic digester

2005 Construction of new influent pump station

Next Chemical mist air scrubbers and biofilters for odor control

Clean Water Services is a water resource management utility for more than 480,000 people in urban Washington County and small portions of Multnomah County, Clackamas County, Lake Oswego, and Portland. Clean Water Services operates four wastewater treatment facilities, constructs and maintains flood management and water quality projects, and manages flow in the Tualatin River to improve water quality and protect fish habitat. Although Clean Water Services maintains a close working relationship with Washington County government, it is a separately managed and financed public utility.

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