M63, Aquifer Storage and Recovery provides a general understanding of the principles of aquifer storage and recovery (ASR). The manual discusses the concept, regulations as they are applied nationally and by state, basic design and development criteria, and presents results of an inventory of ASR well sites nationally. Both successful projects and ones that faced challenges are profiled. M63 provides management, operations, and engineering staff with an understanding of ASR to help them make decisions on investigations and installations when problems or the need to expand supplies arise, as...