Water Quality

Water quality within the Priest Rapids Project area supports domestic, industrial and agricultural water supply, stock watering, wildlife habitat, fish spawning, migration and rearing.  The reservoir shorelines are largely undeveloped and undisturbed.  There are few commercial and industrial water users.

The Priest Rapids Hatchery uses groundwater and river withdrawals from the Columbia River to support that hatchery’s functions.  Other important uses include fish and wildlife habitat, primary contact recreation and cultural and aesthetic resources.

Any use of surface water is subject to the Clean Water Act, which gives the Environmental Protection Agency (EPA) authority to set and/or approve water quality standards throughout the nation. The Washington State Department of Ecology sets water quality standards for Washington State, subject to EPA review and approval.

Grant PUD currently operates and maintains four, fixed-site water quality stations within the Priest Rapids Project Area. These sites are located in the forebays (Wanapum head and Priest head) and tailraces (Wanapum tail and Priest tail) of Wanapum and Priest Rapids dams. A multi-probe water quality measuring device located at each station collects water temperature (Temp - Celsius - ° C), barometric pressure (mm/hg) and total dissolved gas (TDG - percent saturation) data on an hourly basis. Bi-weekly grab samples of Turbidity, Dissolved Oxygen and pH are also collected from these sites.

Data collected from the four, fixed-site water quality stations is used to document the status of key water quality variables within the Priest Rapids Project area and to comply with Grant PUD’s 401 water quality certification.

To learn more about the Clean Water Act, visit www.epa.gov/region5/water/cwa.htm#Intro

For more about Washington state water quality standards, visit
http://www.ecy.wa.gov/programs/wq/links/standards.html