AN OVERVIEW OF AQUIFER STORAGE AND RECOVERY PROJECTS IN UTAH

Aquifer storage and recovery (ASR) projects can be valuable tools for the conjunctive management of surface- and ground-water resources in the U.S., especially the arid West. ASR projects involve storage of water in an aquifer via managed aquifer recharge when water is available, and recovery of the stored water from the aquifer during times when water is needed. ASR project methods have varied depending on local goals and site conditions. ASR can be used to enhance ground-water quality, reduce pumping lifts, store water, or salvage storm-water runoff. ASR can be accomplished by surface spreading/ponding of water in areas where surficial deposits are highly permeable, or by injecting surface water into an aquifer using specifically designed ASR wells. Both methods have inherent advantages and disadvantages.

ASR has been used in Utah at varying scales since 1936 to both augment ground-water availability during dry seasons and years, and to improve ground-water quality. Four early ASR experiments in Utah between 1936 and 1955 used surface-water spreading or ponding of surface water as the recharge method to augment ground-water resources. Two experiments resulted in increased water levels in wells near the recharge sites, one experiment yielded inconclusive results due to a poor monitoring well network, and another was unsuccessful because confining beds separated the target aquifer from the recharge water. One current ASR project in Utah, using injection wells, is designed to both augment ground-water resources and improve ground-water quality. Several other ASR projects in Utah exist, using either surface-water spreading/ponding, well injection, or combinations of both. Each past or current project encountered challenges. To maximize benefits and to avoid pitfalls, regardless of method used, it is important to have a good understanding of geologic and hydrologic conditions at the ASR site, and the requirements that will be imposed by regulatory agencies.