Beaverton ASR Program

The City of Beaverton was GSI's first client. We have been helping the City manage and expand its ASR program since 2000.

The City of Beaverton brought its first ASR well online in 1998, converting an unused municipal well into an ASR well at the Sorrento wellfield to help offset peak demands and accommodate the anticipated population growth in the area. Following the success of this ASR well, GSI designed two additional deep ASR wells that have a combined storage of 450 million gallons and a recovery capacity of 6 million gallons per day. The system provides roughly 30 percent of daily water consumed during the summer.

As hydrogeologist of record, GSI is helping the City to plan and develop additional ASR wells. ASR No. 6 and ASR No. 7 will be developed near the top of Cooper Mountain, and GSI also is helping the City replace its original ASR well (ASR No. 1) with a new higher-capacity ASR well (ASR No. 5). Overall, the City is planning to develop nearly 1 billion gallons of storage and possibly up to 10 MG of recovery capacity during the next 10 or more years in the Cooper Mountain area. Additionally, GSI personnel continue to provide the City with ASR operational support, including technical support related to permitting, annual reporting, and water quality and ASR system monitoring to track the dynamic response of the basalt aquifer to ASR activity.

The City's ASR wells provide a critical source of backup supply. Drilled in the deep basalt, the City's ASR wells are designed to be seismically resilient with strong casings and backup generators for use in an emergency situation. The Sorrento wellfield is capable of storing a combined 450 million gallons of water, which can serve as an in-town source of emergency water should the City's transmission line from the Joint Water Commission's facility in Forest Grove become compromised.

GSI’s work has involved:

  • Conducting feasibility studies and designing ASR wells to optimize production in the Columbia River Basalt Group aquifer.
  • Providing operational support, including licensing, water level monitoring, water quality monitoring and control, monitoring of groundwater seeps, long-term monitoring and data management, and yearly reporting.
  • Completing numerical groundwater modeling to determine if the City's ASR wellfield could accommodate another ASR well. As a result, ASR No. 5 will be completed in the basalt, much deeper than the other wells in the wellfield. This will support greater storage capacity and minimize interference between wells.


Beaverton, Oregon


  • ASR development and operations
  • ASR feasibility studies
  • ASR operations and maintenance
  • Annual reporting and regulatory support
  • Groundwater modeling
  • Resiliency planning

GSI has supported the City's ASR program since our founding in 2000.

Photo Gallery

This well house blends into the surrounding development. From the street, it looks like an ordinary home.

A GSI employee visits ASR No. 2