Comparison of Technical and Regulatory Issues of ASR Programs in the Arid Southwest

Tuesday, April 13, 2010: 11:45 a.m.
Lawrence A/B (Westin Tabor Center, Denver)
Yemia T. Hashimoto , AMEC Geomatrix, Inc., Oakland, CA
William Greg Hamer, PG, CHG, CEG , AMEC Geomatrix, Corona, CA
In the arid Southwestern United States increasing population and water demand have resulted in the mining of groundwater in many areas.  By using wells for injection of water into an aquifer (instead of recharge ponds) an aquifer storage and recovery (ASR) program can supplement groundwater supply and reduce groundwater overuse without occupying large areas of increasingly scarce open land.

 

The success of an ASR program is dependent upon both technical and regulatory considerations, both of which vary on a case by case basis.  Technical aspects are dependent upon the goal of the ASR and require a multi-disciplinary approach that includes engineering, hydrology, and economic contributions.  Regardless of the technical aspects, the success of an ASR program may be ultimately determined by the federal and state regulations guiding the operation of the ASR program. 

 Policy considerations depend upon continued and active education and communication with regulators and present many challenges.  Because an ASR program circumvents the natural process of percolation of this characteristic, the ASR system is potentially affected by several federal rulings including the underground injection control program, as well as the Environmental Protection Agency (EPA) disinfection byproducts rule and groundwater rule for recovery of treated drinking water.  However, groundwater management and development is conducted at a state level.  A state would determine ownership of the stored water, issue permits for storage and recovery, and enforce laws against degradation of groundwater quality by injection or land-use practices.  There are many ASR programs in operation in the arid southwestern United States and each one has faced various technical and regulatory challenges. As water demands continue to increase, additional ASR programs will be needed. The success of these programs will depend in large part on the technical and regulatory lessons learned from the programs already in place.