Aquifer Recharge, Storage, and Recovery - Southwest Hydrology ...

ASR from a Legal PerspectiveDenise D. Fort – University of New Mexico School of LawDrought, population growth,groundwater mining, and ahost of other challenges areaccelerating the search for new approachesto water supplies. One promising approachalready utilized throughout the UnitedStates is using groundwater aquifers forstorage and retrieval of waters. I servedas a participant on the National ResearchCouncil’s panel on managed undergroundstorage (here termed aquifer storageand recovery, or ASR) and found thetopic to be a rich one for considerationby institutional researchers, because thepractice raises an array of legal questions.The regulatory structure for ASR iscomplicated because the legal arrangementfor managing water historically hasseparated water quality and water quantity,as well as groundwater and surface water.Several water quality schemes may applyto ASR projects. In certain circumstancesauthority is divided between the federaland state governments, and states varyin how stringently they regulate theseprojects. The water quality questions maypale in comparison to the water quantityissues. Water allocation is primarily amatter of state control, but states varyin how they view the right to store andwithdraw water. Ownership and control ofaquifer storage raise yet other legal issues.Water QualityThe regulatory system for protectionof water quality depends on how ASRprojects are undertaken. In general,protection of the groundwater aquifer isregulated by states, and therefore standardsvary. Protection of wellheads of drinkingwater systems is a matter of federal law,administered by the states. States may infact provide a higher degree of protectionfor aquifers than required by federal law.The greatest sources of regulatoryconflict seem to be over the degreeof protection required for aquifers. Ifa state prohibits any degradation ofan aquifer, this puts a costly burdenon an ASR project developer. From apragmatic perspective, the question iswhether it is preferable to require a highdegree of treatment before injection/infiltration, or after water is withdrawn.Have most states sufficiently weighedthe water resource and pollution risksand benefits of ASR projects againstthe long-term protection of aquifers?Probably not, since such projects still arerelatively novel. In fact, nondegradation ofaquifers may be a standard that preventsprojects from going forward that offergreater benefits than risks, and causescostlier treatment than is necessary.Federal involvement in ASR projects isrelatively limited. Insofar as projects areconducted through injection wells, federalUIC (Underground Injection Control)regulations apply, either through theU.S. Environmental Protection Agencyor state-delegated programs. Rechargethrough infiltration is not regulatedby the EPA, although permits may berequired for the discharge to surface water(National Pollutant Discharge EliminationSystem permit) and for alterations tostreambeds (Section 404 of the CleanWater Act). The distinction appears to bean accidental consequence of the federalregulatory structure, and not a statementabout which type of project presentsgreater risks to aquifers. The federalUIC program is a narrow groundwaterprotection program directed at a particularsource of groundwater pollution, theinjection of wastes into groundwater.Another policy question is whetherthe federal government should bemore involved in regulation of theseprojects, or less. The current federalrole seems to be as a backstop forinadequate state regulation, but onlyfor certain types of projects.In general, one could argue for anexpanded federal role in groundwaterAquifer testing of the City of Phoenix’s newest ASR well.22 • May/June 2008 • Southwest Hydrology