2 ASR wells operated by Walla Walla are capable of injecting 400-500 million gallons of water per year into the Columbia Basalts. The City would like to use these wells to supplement peak demand and emergency storage; however, recover of water has not yet been approved (as of 2012).
- In 1999, the city converted a deep well into an ASR well. In 2003, a second well was converted to an injection/recovery well.
- From 2000-2003 a total of 13,846 million gallons of surface water was captured for ASR injection
- 1st ASR well: Drilled in 1941. Depth 810 feet, 15-inch casing to 138 feet. Upgraded to ASR in 1999.
- 2nd ASR well: Drilled in 1961. Depth 1,330 feet, 24-inch casing to 285 feet. Upgraded to ASR in 2003.
Aquifer levels have risen 20-30 feet per year in injected area. An average of 286 million gallons injected every year, expecting up to 500 million gallons (as of 2006)Information obtained from:
HDR Engineering. 2006. Comprehensive Water System Plan Update-Final Report. Prepared for the city of Walla Walla. 250 p.