In response to a Congressional request, the U.S. Environmental Protection Agency needed to identify the risks and opportunities associated with the use of stormwater in enhanced aquifer recharge systems. U.S. interest in EAR has increased in the past decade, particularly in the western and southern United States, and stormwater EAR has potential to address many water resource problems: ensuring sustainability of public water supplies, restoration of degraded ecosystems, flood protection, and enhancement of water quality. However, stormwater EAR in the United States is still in its infancy and more widespread adoption carries significant risk, including the potential for aquifer contamination.
ERG reviewed and synthesized the scientific and technical literature and developed the “Enhanced Aquifer Recharge of Stormwater in the United States: State of the Science Review” report, which describes current knowledge, best practices, and knowledge gaps for stormwater EAR. In addition to responding to the Congressional request, this report provides a benchmark and go-to resource for EAR practitioners interested in best practices for effective and safe stormwater EAR in diverse land use and hydrogeologic settings. The knowledge gaps identified provide a basis for informing future recommendations for effective and safe stormwater EAR.