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 three operating ASR wells (ASR well numbers one, two, and four) that have a combined groundwater pumping capacity of 6 million gallons a day (mgd).

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 Department of Human Services Drinking Water Program. Learn more about Beaverton's drinking water quality.

ASR Statistics / Facts

• From June 2008 to October 2008, 328 MG of stored water were recovered from the ASR wells and pumped into City water mains to help meet summer customer demand.
• Stored water pumped out of the City’s three ASR wells made up nearly 12% of the City’s total annual drinking water distributed to customers in 2008.
• The City owns a fourth ASR Well (ASR number 3), which is already drilled and is expected to be operational in 2011.
• Using ASR, the City stored approximately 450 MG of drinking water in underground aquifers during the winter and spring of Fiscal Year (FY) 2007-08, with a total of 428 MG available for recovery after the state-mandated 5% reduction of the storage account.