Aquifer Storage & Recovery

Storing Drinking Water Underground

Aquifer storage and recovery (ASR) is a way of storing drinking water underground, then pumping it out when it is needed. During the winter and spring, Beaverton injects treated drinking water from the Joint Water Commission (JWC) Water Treatment Plant into natural underground basalt formations (aquifers), displacing native groundwater. Stored water in the aquifer is pumped out of the ASR wells during the summer when demand increases as customers drink more water and use it for outdoor activities, such as irrigation for landscaping and gardens. The City currently has two operating ASR wells (ASR Well No. 2 and Well No. 4) that have a combined groundwater pumping capacity of 5 million gallons a day (mgd).

A third ASR well (No.1), reached the end of its useful life in 2012 and is now out of service. To replace ASR No. 1, the City successfully applied for and received a $5 million loan and loan-forgiveness funds from the State of Oregon IFA (Infrastructure Finance Agency) to construct ASR Well No. 5. Preliminary planning and engineering for proposed ASR No. 5 are complete, and the new well is anticipated to yield 2 mgd and is scheduled to be operational in 2018. Separately, a new 24-inch diameter well (ASR Well No. 6) was drilled in 2015 in the Reserve at Cooper Mountain subdivision. The future ASR No. 6 pump station building will be housed in a structure that resembles a residential home, designed to blend in with the surrounding homes, and would be able to serve drinking water to all residents within the City limits. The timeline for construction of the future pump station is dependent on water demand in the South Cooper Mountain upper pressure zone area.

Why ASR is Important to Beaverton

Beaverton uses ASR for the following reasons:
  • ASR conserves surface water from primary sources (rivers and dams) during environmentally stressful summer seasons. Beaverton has reduced its diversion of limited summer river streamflow and/or water stored behind dams by substituting stored water recovered from ASR wells.
  • ASR helps delay the need to purchase water from new sources and/or build new water improvement systems (such as pipelines, reservoirs, and treatment plant expansions).
  • ASR water is used to bridge the gap when peak summer drinking water demands (up to 17 on a single MG day) exceed available supply capacity (14 mgd in the water transmission system).

Ensuring ASR Water Quality

Although the water that is injected into City ASR wells has been treated, rigorous water quality testing and data collection are performed on water from the ASR wells to ensure that water quality meets state and federal standards. Data collected on the City’s ASR program are reported each year to the Oregon Health Authority and the Oregon Water Resources Department. Learn more about Beaverton's drinking water quality.

ASR Statistics / Facts

  • In 2015, a total of 413.7 MG of stored water and native groundwater were recovered from the ASR wells to help meet summer customer drinking water consumption.
  • Drinking water from ASR wells represents up to 30 percent of daily water consumed in the summer period, and 16 percent of all water consumed in 2015 by Beaverton water customers.
  • Since 1999, the City has pumped out (recovered) over 3.71 billion gallons of potable water from ASR wells and native groundwater reserves to help meet peak summer season water demand.
Beaverton drinking water sources