[3] Later that year, voters in the new district approved a $36 million bond measure to consolidate, construct and upgrade USA's regional public wastewater treatment facilities.

[5] A Clean Water Act amendment added regulation of storm-water runoff, and the Rock Creek Facility achieved 99% removal of ammonia nitrogen.

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.

[7][8] This program received approval from environmental regulators and was in lieu of spending $150 million to build chilling systems at the four treatment facilities.

[13] The wastewater is collected by a vast network of more than 800 miles (1,300 km) of sewer lines and 39 pump stations and routed to one of four treatment plants—Durham, Rock Creek, Hillsboro and Forest Grove.

[15] In 2007 the Durham facility began working with Ostara Nutrient Recovery Technologies to construct a $2.5 million multi-reactor plant [16] that allows the Durham facility to run part of its waste stream through special reactors that transform potentially damaging nutrients into environmentally friendly fertilizer, which Ostara sells commercially.

In cooperation with Washington County and the 12 member cities Clean Water Services maintains and enhances the public drainage system to meet public needs and to comply with strict water quality regulations set for the Tualatin River drainage area by the Oregon Department of Environmental Quality (DEQ).

[13] Clean Water Services offers a classroom educational program called River Rangers geared toward 4th-grade students.

[21] The two water supply options being considered assume aggressive conservation targets for homes and businesses, wastewater reuse, and aquifer storage and recovery.