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

ASR and the “Big Picture”Cat Shrier – Watercat Consulting LLCHundreds of water providersthroughout the United Statesare already using some formof well or surface recharge for managedunderground storage (MUS, calledaquifer storage and recovery [ASR] inthis publication) as an integral part oftheir water supply management. TheCongressional Water Caucus recentlyidentified “groundwater banking” asa priority for U.S. water policy.Yet as a 2008 National Research Council(NRC) report reveals, little quantifiable,reliable information is available regardingtotal amounts of water stored underground,subsurface storage locations, or availablestorage. Nor are there widely acceptedmetrics for assessing storage suitability,economic and financial costs and benefitsof ASR, or ways to compare and combinesurface and subsurface storage alternativesfor conjunctive (joint groundwater andsurface-water) management. This lackof information, along with inconsistentregulatory guidance, creates challengesfor individual providers consideringASR, but is also a problem for plannersconsidering the bigger picture: How can weapply and integrate ASR into conjunctivewater management to address regionaland national or federal priorities?On March 19, 2008, NRC hosted aforum in Washington, D.C., to discussinstitutional issues of managed undergroundstorage such as science- and risk-basedASR policy and regulations for watersupply and protection of health and theenvironment; and monitoring, management,and planning. Held in partnership withthe Ground Water Protection Council,National Ground Water Association, andGroundwater Resources Association ofCalifornia, the forum attracted speakersand participants from more than 25 statesand three federal agencies. Some pointsand questions raised at the forum follow.Public and Policy Maker EducationEducation was widely recognized as acritical component for ASR to be perceived20 • May/June 2008 • Southwest Hydrologyand accepted as a mainstream tool forwater management. The Southwest hasgenerally higher water knowledge thanother regions, and most western stateshave ASR-specific permitting regulations.However, nationally and federally,the concepts, challenges, and benefitsassociated with ASR have been poorlycommunicated to policy makers and thepublic, making it hard to gain public trust.Efforts to address policy and managementaspects often become bogged downover technical details and debatesover terminology—such as whetherto use “ASR” or “MUS”—or derailedby characterizations of ASR as anexperimental and untested technology inspite of its widespread use. Many watermanagers discount ASR, saying “Weuse surface water, not groundwater.”Groundwater organizations have takenthe lead on organizing ASR symposiaand developing educational materials—but since most ASR system suppliesare surface water, is ASR really just agroundwater issue? Policy makers andthe public usually understand water onlyin surface-water terms. What metrics andeducational tools could help translateASR benefits and constraints into termsthat fit a surface-water paradigm?UIC and Groundwater ProtectionThe biggest direct federal involvement inASR comes from the U.S. EnvironmentalProtection Agency’s UndergroundInjection Control (UIC) program. ASRwells are “Class V” wells, a catch-allcategory mainly for permitting wastedisposal. UIC is implemented by statesif EPA grants them primary enforcementresponsibility, or by regional EPA offices.EPA headquarters is completing an internalreview on how ASR works, but has notprovided states or regional agencies withguidance on UIC interpretation, resultingin inconsistent permitting approaches.UIC-related questions raised in the NRCreport and forum include: 1) Do residencetimerequirements reflect site-specificconditions for different constituents? 2) Arestate interpretations of “antidegredation”preventing ASR development in caseswhere the risk is remote of impactingother groundwater users pumping froman underground source of drinking waterand where the benefits to the watersupply—and even water quality—are high?3) Do primary drinking water standardsneed to be met at the wellhead or at theedge of a limited zone of conditioning?State agencies, regional EPA staff, andwater providers at the forum saw no needfor new regulations, and stressed thatpermit requirements must be specific tosite conditions, operations, and risk ofadverse interactions between the storedwater and water in the aquifer. However,they requested federal guidance formore consistent interpretation of UICand funding to develop approachesfor ASR permit application review.Federal SupportWhile water supply issues are handledat the state level, federal agencies havelong been involved in ASR, from theU.S. Geological Survey’s post-WorldWar II groundwater recharge studiesto the U.S. Bureau of Reclamation’sGround Water Recharge DemonstrationProjects of the 1980s, a major catalyst forwestern ASR development. The proposedSECURE Water Act would increase theactivities of USGS and Reclamationrelated to water resources data and wateravailability, including groundwater. Willthese studies consider use of aquifers notjust as groundwater reserves but also aspotential underground storage zones?The U.S. Army Corps of Engineers’(Corps) Water Resources Principles& Guidelines (P&G), which providestandards for evaluating water resourcesmanagement alternatives and planning,are being reviewed and updated (see page8). Colorado, Utah, and Oregon havedeveloped metrics for evaluating potentialunderground storage areas, as has the