In 1969, Oregon's Department of Environmental Quality placed a temporary halt to new construction in Washington County. On February 3, 1970, ten cities and sixteen sanitary districts combined to form the Unified Sewerage Agency (USA). Two years later six more treatment plants were replaced with the opening of the Rock Creek Wastewater Treatment Facility. As population continued to grow in the service area of USA, the water quality of the Tualatin River worsened. In 1986, the Northwest Environmental Defense Center filed a lawsuit against the
United States Environmental Protection Agency, prompting
Total maximum daily loads for the Tualatin River. A
Clean Water Act amendment added regulation of storm-water runoff, and the Rock Creek Facility achieved 99% removal of ammonia nitrogen. In 1988, the Tualatin Valley Water Quality Endowment Fund was established by the Northwest Environmental Defense Center lawsuit. USA worked to maintain the quality of the Tualatin River by establishing Surface Water Management (SWM) utility for water quality and drainage in 1990, and began a $200 million facility expansion and upgrade program to meet compliance deadlines. That same year, the agency established the River Rangers program. USA began consumption-based rates and combined billing with water providers in 1994. In July 2001, the Unified Sewerage Agency renamed itself as Clean Water Services at a cost of $60,000. Clean Water Services' Operations Building opened in 2003, which is used as a showcase of low impact development. The same year, the Administrative Building Complex opened. It was the first LEED Gold certified public building in Washington County. In 2004, the agency began a program to add shade along the watershed's streams and river by planting trees and shrubs to lower temperatures of the waterways. This program received approval from environmental regulators and was in lieu of spending $150 million to build chilling systems at the four treatment facilities. and in 2008 the Durham facility's Influent Pump Station was the first to earn LEED Silver certification. The following year the Durham plant became the United States' first wastewater treatment plant to produce commercial fertilizer. In 2010, the Clean Water Institute was established by the agency. ==Services==