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

T h e R e s o u r c e f o r S e m i - A r i d H y d r o l o g yVolume 7/Number 3 May/June 2008Aquifer Recharge,Storage, and RecoverySouthwest HydrologyUniversity of Arizona - SAHRAP.O. Box 210158-BTucson, AZ85721-0158Address Service RequestedA publication of SAHRA, an NSF Science and Technology Center

A few thoughts about a good team:Joining founding partners(from left) Doug Bartlett andMarvin Glotfelty as Principalsof Clear Creek Associatesin Phoenix are:Thomas R. Suriano, R.G., joinedClear Creek in 2006, bringingtwenty-two years of experiencemanaging environmental andwater resources projects.Donald P. Hanson, R.G., joinedClear Creek in 2000 and hastwenty-two years of experiencemanaging environmental andwater resources projects.Announcing Some New PrincipalsBack in 1999, we assembled our new company on one guiding principle:that the value of our services would equal the sum of our staff.Over the years, our success in growing our small company has been areflection of this principle—such that the scope and range of what weprovide is the result of the integrity of our collective professional capabilities.So it is with complete confidence that we are promoting Mike Alter,Don Hanson, and Tom Suriano to positions as principal hydrogeologistsat Clear Creek Associates, responsible for technical, contractual, andbusiness matters.So, three new principals; one long-standing principle; and a single priority:to provide quality-focused, very responsive, integrated hydrologic services.And in Tucson:Michael L. Alter, R.G., joinedClear Creek Associates at itsinception in 1999 as head of theTucson office and brings thirteenyears of experience consultingon environmental and waterresources projects.in Phoenix:6155 E. Indian School Rd., Suite 100, Scottsdale, Arizona 85251(480) 659-7131, (480) 659-7134 faxin Tucson:221 N. Court Ave., Suite 101, Tucson, Arizona 85701(520) 622-3222, (520) 622-4040 faxwww.clearcreekassociates.com

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T h e R e s o u r c e f o r S e m i - A r i d H y d r o l o g ySouthwest HydrologyPublisherBetsy WoodhouseTechnical EditorHoward GrahnEditorMary BlackA bimonthly trade magazine for hydrologists, water managers, and other professionals working with water issues.Graphic DesignerMike BuffingtonSAHRA Knowledge TransferGary WoodardDoes your region have extra water now that you want to save for later, when there mightbe a drought? You could keep it in a reservoir if you have access to one, but you’ll losesome of the water to evaporation. Or you could let it seep into the ground or inject itdown a well to an aquifer, and plan to pump it back out when you need it. Your biggestproblem may be figuring out what to call this process: in preparing this issue, wediscovered strong and diverse opinions on terminology, especially among experts. Not allwill agree with our decision (see page 16 sidebar), but we believe “aquifer storage andrecovery” most clearly describes what we’re talking about.Did you pay someone for your Southwest Hydrology subscription, or receive it as a“gift”? Say it ain’t so! We recently learned that some unscrupulous entities are offeringSouthwest Hydrology subscriptions for around $10/year and pocketing the money.Southwest Hydrology is FREE! We are taking steps to stop this activity; if you paid,please let us know.Thanks to all of you who responded to our online survey, which was sent to the roughly4,300 subscribers for which we have valid email addresses. We received some excellentsuggestions, many of which we hope to implement in future issues, and learned a lotabout our readers. We will provide more on the results in the next issue. Bottom line: mostrespondents are quite satisfied with Southwest Hydrology and are also happy in theirjobs. And more than half usually or always read this letter—not just my mother!We thank our newest sponsor of Southwest Hydrology: Salt River Project. They, alongwith existing sponsors (see page 9) and our advertisers, help make continued freepublication possible. We also thank all contributors to this issue.Betsy Woodhouse, PublisherFrom thePublisherThe Vidler Recharge Facility, about 90miles west of Phoenix, recharges CentralArizona Project water through some460 acres of infiltration basins. Thewater will be recovered in the futureby Vidler or its buyer, for currentlyundetermined use(s).Cortney C. BrandGreg BushnerMark CrossDenise D. FortPeter FoxGerald E. GallowayKenneth GlotzbachContributorsAdvisory BoardDavid Bolin, R.G.Charles Graf, R.G.Jim Holway, Ph.D.Jeff JohnsonDavid Jordan, P.E.Karl Kohlhoff, P.E., B.C.E.E.Stan LeakeAri Michelsen, Ph.DMark Murphy, Ph.D.Peggy RoeferMartin Steinpress, R.G., C.HG.Printed in the USA by CityPressMario R. LluriaSharon B. MegdalAri M. MichelsenChristian E. PetersenTaylor ShipmanCat ShrierSouthwest Hydrology is published six times per year by theNSF Center for Sustainability of semi-Arid Hydrology andRiparian Areas (SAHRA), College of Engineering, The Universityof Arizona. Copyright 2008 by the Arizona Board of Regents.All rights reserved. Limited copies may be made for internaluse only. Credit must be given to the publisher. Otherwise,no part of this publication may be reproduced without priorwritten permission of the publisher.ISSN 1552-8383SubscriptionsSubscriptions to Southwest Hydrology are free. To receive themagazine, contact us as shown below.AdvertisingAdvertising rates, sizes, and contracts are available atwww.swhydro.arizona.edu. Please direct ad inquiries to usas shown below. Space must be reserved 50 days prior topublication date.Free Job AnnouncementsSouthwest Hydrology will publish job announcements in theEmployment Opportunities section. The first 70 words foreach announcement is free; after that, the charge is $70 peradditional 70 words. To place an ad, contact us as shownbelow. All announcements, of any length, may be posted onour website for no charge (www.swhydro.arizona.edu).Editorial ContributionSouthwest Hydrology welcomes letters and contributionsof news, project summaries, product announcements, anditems for The Calendar. Send submissions by mail or email asshown below. Visit www.swhydro.arizona.edu for additionalguidelines for submissions.Web SitesSouthwest Hydrology - www.swhydro.arizona.eduSAHRA - www.sahra.arizona.eduCONTACT USSouthwest Hydrology, The University of Arizona, SAHRAPO Box 210158-B, Tucson, AZ 85721-0158.Phone 520-626-1805. Email mail@swhydro.arizona.edu. • May/June 2008 • Southwest Hydrology

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Inside This IssueDepartments8 On the Ground• WRDA 2007 water policy provisions,by Gerald E. Galloway andAri M. Michelsen• Arizona’s groundwater savingsprogram, by Sharon B. Megdal andTaylor Shipman12 Government• Water scarcity and growthin Southern California• New Mexico mulls regulationof deep aquifers• New Mexico and Texasresolve 29-year dispute• Rio Grande pits Mexico versusTexas; disagreement heads to Canada• Oil shale projects could impactColorado water• EPA wastewater infrastructureneeds $202 billion• Bromate spike in Los Angelesreservoirs12 HydroFacts34 R&D• Dire predictions for ColoradoRiver reservoirs• Mussel menace update: theyseem to be thriving• Water quality impacts toshallow groundwater• Human activities linked tochanges in water resources• Coachella Valley is sinking atincreasing rates• Extreme precipitation eventslinked to global warming• Integrated energy/water modelin the works41 In PrintDamming Grand Canyon: The 1923USGS Colorado River Expedition,reviewed by Betsy Woodhouse42 CalendarAquifer Recharge, Storage, and RecoveryIn this issue we define the deliberate recharge and temporary storage of “excess”(unneeded) water in an aquifer, with the intent of recovering that water for future use,as aquifer storage and recovery (ASR). The technique is increasingly being used asa water management tool. The implementation of ASR projects varies widely in thetype of water used, method of recharge, aquifer type, and engineering of the project,as described in these feature articles. Furthermore, water quality changes resultingfrom mixing two different waters must be considered, as well as regulatory andpolicy constraints. And do you really get that water back? Read all about it…16 An ASR PrimerCortney C. BrandWhat is aquifer storage and recovery?What are its benefits and limitations?How does it work? Who is doingit? Comparing a number of ASRprojects in the Southwest illustratesthe range of objectives, watersources, aquifer types, and rechargeand recovery methods utilized.18 Hydrogeology and ASR DesignGreg BushnerSite hydrology is critical to the successof an ASR project. What factors shouldbe considered in evaluating land andwater? Which data are needed todetermine site and soil suitability andensure nondegradation of water quality?20 ASR and the “Big Picture”Cat ShrierA recent National Research Councilreport and forum identified institutionalissues that have prevented ASR frombeing more widely accepted. Althoughthe details of any project are local,some actions taken at the federaland regional levels could facilitatemore widespread use of aquifersas potential storage zones and forconjunctive water management.22 ASR from a Legal PerspectiveDenise D. FortThe regulatory structure for ASR iscomplex because the legal systemhas historically addressed waterquality issues independently of waterquantity, as it has groundwater andsurface waters. Authority over aproject may also be divided betweenfederal and state governments.Publishing Southwest Hydrology furthers SAHRA’smission of promoting sustainable managementof water resources in semi-arid regions.24 Water Quality Changes DuringSubsurface StoragePeter FoxMixing of existing groundwater andintroduced water in an ASR systemcan impact water quality as well as thehydraulic capacity of injection wells.What are the potential problems andmethods of treatment that can be usedto prevent or mitigate these challenges?26 What About the “R” in ASR?Betsy WoodhouseAfter injecting water undergroundvia wells or letting it seep throughshallow basins, is it possible toget all that water back again whenyou need it? What is storage? Howdoes recovery actually work?28 Water Spreading in the DesertMario R. LluriaFollowing completion of the CAPaqueduct, the Salt River Projectand Phoenix-area municipalitiesinvestigated in-channel rechargeas a way to preserve Arizona’sunused allocation of ColoradoRiver water. Today two rechargefacilities store almost one millionacre-feet of water annually.30 ASR in Roseville: Navigating WaterQuality IssuesChristian E. Petersen andKenneth GlotzbachAn ASR demonstration project inRoseville, California, is improvingunderstanding of the water qualityimplications of underground injectionand recovery. Results show a five-footrise in groundwater levels, significantreductions in TDS levels, andattenuation of disinfection byproducts.This publication is supported by SAHRA (Sustainability of semi-Arid Hydrology and Riparian Areas) under the STC Program of the National Science Foundation, AgreementNo. EAR-9876800. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect theviews of SAHRA or of the National Science Foundation. • May/June 2008 • Southwest Hydrology

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ON THE GROUNDNew Directions in Water Policy:WRDA 2007Gerald E. Galloway – Dept. of Civil andEnvironmental Engineering, Univ. of Marylandand Ari M. Michelsen – Texas AgriLifeResearch Center, Texas A&M Univ.Since 1976, the U.S. Congress hasauthorized the construction of waterresource projects by the Army Corpsof Engineers through the periodicpassage of water resource developmentacts, which also promulgate waterresource policies and programs.Last October, Congress sent the WaterResource Development Act of 2007(WRDA 2007) to President Bush. Itauthorized more than 900 projects, studies,and programs. Citing the large numberof projects and total cost of near $23billion, the President vetoed it. Congressoverrode the veto and WRDA 2007 wasenacted. It was hailed as a move to addresssignificant infrastructure problems acrossthe country and to reform some of thepolicies and procedures under whichthe Corps carries out its activities.Objectives ExpandedFor 25 years, the defined water resourcedevelopment objective of the Corpsand other water-related agencies hadbeen national economic development(USWRC, 1983), with little recognition ofenvironmental and social costs and benefitsor regional economic development.WRDA 2007, in contrast, states that “allwater resource projects should reflectnational priorities, encourage economicdevelopment and protect the environment,”with attention to minimizing adverseimpacts and vulnerabilities in floodplainsor flood-prone areas; and protecting andrestoring the functions of natural systems.Policy ChangesPrinciples and guidelines: WRDA 2007requires the Secretary of the Army, withintwo years, to revise the principles andguidelines used to formulate, evaluate,and implement water resources projectsby specifically considering: best availableeconomic principles and analyticaltechniques; public safety; environmentaljustice issues and nonstructural approachesto water resources development andmanagement; potential interactionsof a project with other projects andprograms within a region or watershed;and evaluation methods that ensure theprojects are justified by public benefits.Flood vulnerability: WRDA 2007 requiresthe President to submit a report toCongress describing the vulnerability ofthe United States to damage from flooding,including the risk to human life andproperty. The report must also comparerisks faced by different regions of thecountry, assess how well existing programsaddress priorities for reducing flood riskand the extent that they might encouragedevelopment and economic activity inflood-prone areas, and recommend waysto reduce and respond to flood risks.Economic and risk evaluations: TheSecretary of the Army now must assessall project feasibility reports for costeffectivenessand compliance with federal,state, and local laws. The Secretary isfurther directed to adopt a risk analysisapproach to project estimates. For flooddamage reduction projects, the residualrisk of flooding and the loss of human lifeand safety must be calculated, as well asupstream and downstream impacts of theproject. WRDA 2007 also requires benefitsand costs of structural and nonstructuralalternatives to be evaluated equitably, anidea long promoted by the environmentaland floodplain management communities.Independent review: For projects deemedcontroversial or with a total estimatedcost greater than $45 million, or whenrequested by the governor of an affectedstate, WRDA 2007 requires reviewby an independent panel of experts toassess the adequacy and accountabilityof the economic, engineering, andenvironmental methods, models, andanalyses used by the Chief of Engineers.A Step ForwardOver the last seven years there has beenconsiderable debate in Washington abouthow to improve the way water resourceprojects are developed and implemented.WRDA 2007 addresses many of theseissues and requires numerous actionsby the President, Secretary of the Army,and the Corps’ Chief of Engineers tomeet the intentions of the legislation.Unfortunately, in many cases, theseefforts require funding, and littlefunding has been appropriated so far.While far from a perfect solution to acomplex problem, WRDA 2007 representsa major step forward. The response bythe federal government over the next12 to 18 months will indicate how wellthese congressional policy changesand activities are brought into play.Contact Gerry Galloway at gegallo@umd.edu.Contact Ari Michelsen at a-michelsen@tamu.edu. • May/June 2008 • Southwest HydrologyReferenceU.S. Water Resources Council (USWRC), 1983.Economic and Environmental Principlesand Guidelines for Water and Related LandResources Implementation Studies, GPO,Washington, D.C.

May/June 2008 • Southwest Hydrology •

ON THE GROUND (continued)Arizona’s GroundwaterSavings ProgramSharon B. Megdal – Water Resources ResearchCenter and Taylor Shipman – Agriculture andResource Economics, University of ArizonaOne of the more interesting andsometimes debated elements of Arizona’sGroundwater Storage and RecoveryProgram is the Groundwater SavingsProgram (GSP). The program wasdeveloped when Arizona was struggling toutilize its Central Arizona Project (CAP)water. Agricultural water users rejectedthe use of CAP water due to its high costrelative to groundwater. Yet, the higherthe ratio of agricultural to municipal use,the lower were Arizona’s CAP repaymentobligations to the federal government,according to the formula used at the time.By the early 1990s, it was clear that boththe municipal and agricultural sectorswould benefit from a program designed toincrease agricultural use of CAP water.Partnerships Are KeySometimes called indirect rechargeor in-lieu recharge, the GSP allowsstoring entities to accrue groundwaterstorage credits when surface water oreffluent is used for agriculture in placeTonopah IDArizona's GroundwaterSavings Facilities:Cumulative Storagethrough 2006 (acre-feet)0 - 10,00010,001 - 100,000100,001 - 260,000260,001 - 410,000410,001 - 510,000LPSCOMWDRoosevelt IDCentral Arizona Project AqueductActive Management Areas (AMA)30 milesof groundwater. Since 1992, agriculturaldistricts have partnered with entities suchas municipalities, other water providers,SRPMaricopa Stanfield IDDPinal AMAPhoenix AMACAIDDRWCDQueen Creek IDNew Magma IDDHohokam IDDBKW FarmsBKW MilewideTucson AMACMIDthe Central Arizona Water ConservationDistrict (CAWCD, the body responsiblefor delivering CAP water), and the ArizonaWater Banking Authority (AWBA,the independent government authorityauthorized to store CAP water for timesof drought). They are able to provideCAP water to farmers at a cheaper ratethan what farmers would pay directly,and they gain storage credits when thatwater is used for agriculture. Throughsuch arrangements, approximately3.5 million acre feet of CAP water havebeen used instead of groundwater ingroundwater savings facilities (GSFs)in the three central Arizona ActiveManagement Areas (see figure above.)Three different types of permits—facility,storage, and recovery—are involved inimplementing this program, which isadministered by the Arizona Departmentof Water Resources. The agriculturalentity holds the facility permit. Thestoring entity holds the storage permit10 • May/June 2008 • Southwest Hydrology

and accrues the credits that entitlethe credit holder to recover the storedwater. More than one entity can be astorage partner. Finally, recovery of thewater must be accomplished througha well permitted for that purpose.Benefits and ConcernsStorage at GSFs has the advantage oflower costs. The storing entity usually paysonly a portion of the CAP water costs,with the agricultural user picking up therest. In most cases, there is no facilitycharge associated with storing groundwaterat the site. Contrast this with storageof CAP water at underground storagefacilities (USFs), at which the storingentity pays the entire cost of the water tobe stored in addition to a charge paid foruse of the USF. Recovery considerationscan be advantageous at GSFs as well.For an agricultural district, a GSF’s areaof hydrologic impact, where recoverywell permits can be administrativelyeasier to obtain, is the entire district.Concerns about GSFs have mainly centeredon the perpetual groundwater use rightsof agricultural water users in the ActiveManagement Areas. Should affordableCAP water no longer be available, theagricultural entity has the right to returnto groundwater use and benefit fromthe higher water levels resulting fromnot having pumped the groundwaterwhile using CAP water. There are alsoquestions about the water managementimplications of recovery outside the areaof hydrologic impact, potentially resultingin recovery at significant distance fromthe storage. (This concern is not unique tothe GSP.) The chart (above right) showsthat much of the GSF storage has beenon behalf of CAWCD and the AWBA,with planned recovery occurring in thefuture and perhaps outside the area ofhydrologic impact. Because recoveryplans have not yet been developed, thepotential hydrological disconnect betweenstorage and recovery is a concern.What is unarguable about the GSP isthat this voluntary water exchangemillion acre feet groundwater stored4.03.53.02.52.01.51.00.50MunicipalArizona Water Banking AuthorityCentral Arizona Water Conservation Districtmechanism benefits the participatingentities while furthering Arizona’s watermanagement objectives. Over 3.5 millionacre-feet of CAP water has been usedin lieu of pumping an equivalentamount of groundwater using this lowcostmechanism. The program enablesmunicipal water providers to utilize CAPwater indirectly and inexpensively tocomply with regulatory requirements foruse of renewable supplies. It is a lowcostalternative for the AWBA. Farmersbenefit from water costs below whatthey otherwise would incur, courtesyof their groundwater savings partners.The popularity of the groundwatersavings program is based on the simpleeconomic principle that voluntarytransactions yield mutual gains.For more information, see Artificial Recharge, AMulti-Purpose Water Management Tool, Arroyo,Winter 2007 at ag.arizona.edu/azwater/arroyo/.Contact Sharon B. Megdal at smegdal@cals.arizona.edu.1992 1994 1996 1998 2000 2002 2004 2006Cumulative storage in Arizona’s groundwater savings facilities, by type of storer.Innovative Solutions in Hydrology2015 N. Forbes Ave. Suite 105Tucson, Arizona 85745Phone: 520.628.9330 • Fax: 520.628.1122www.geosystemsanalysis.comGroundwaterRecharge StudiesMine Closure andReclamation StudiesWater ResourcesHeap Leach OptimizationVadose Zone MonitoringFlow and Transport ModelingHydrologic Testing LaboratoryMay/June 2008 • Southwest Hydrology • 11

GOVERNMENTSouthern California WaterScarcity Affecting Growth?In February, Metropolitan Water Board(MWB) in Southern California adopteda region-wide plan for sharing waterduring shortages that will guide theequitable distribution of water amongits 26 member public agencies. The planconsiders member agencies’ dependencyon MWD water and alternative sourcesof supply, and assesses “penalty rates”that increase as agencies exceedtheir allocations. Previously, MWBhad determined allocation solely on“preferential rights” which were basedon an agency’s financial contribution.Recent court-ordered reductions ofwater deliveries from the SacramentoDelta and ongoing drought wereimportant factors in MWB cuttingHydroFactsTerm most widely used internationally for recharging, storing,and recovering water from an aquifer:supplies to its local water districts byup to 30 percent in early January, saidthe Riverside Press-Enterprise.In response to the new plan, one ofthe affected member agencies, EasternMunicipal Water District (EMWD),placed new retail and communitydevelopments in western Riverside Countyon hold in January, saying it could notyet guarantee water for a warehouseproposed for Moreno Valley and a$300 million hotel and retail complexin Murrieta, according to the Press-Enterprise. Seven other developmentswere already on hold because theirwater supply could not be assured.A 2001 bill passed by the Californialegislature requires major developmentsto get “will-serve” letters from theirwater providers before they canproceed with construction, assuring aManaged Aquifer Recharge (MAR)Number of wells in Chennai, India (formerly Madras, pop. 7.5 million)used to recharge rainfall from mandatory rooftop harvesting systems: 400,000Density of wells in Chennai:15/hectare, or 6/acreSource: Steve Gorelich, Stanford UniversityEstimated capacity of recharge facilities, by recharge methodology, in cubic meters:vadose zone wells (per well) 1,000 - 3,000recharge & recovery wells (per well) 2,000 - 6,000recharge basins (per hectare per day) 1,000 - 20,000Estimated life cycle for recharge facilities, by recharge methodology, in years:vadose zone wells 5-20recharge & recovery wells 25-50recharge basins > 100Source: Prospects for Managed Underground Storage of Recoverable Water, NRC 2008We Find Water!Aquifer, Science & Technologyspecializes in geophysical surveysfor water resource investigations.We work with Water Agencies,municipalities, industries andtheir hydrogeologic consultantsto provide practical and focusedsurface and bore hole surveys.We find water! Let us findsome water for you too!Aquifer Science & TechnologyYour Ground Water Resourcesupply for 20 years. The delays of newdevelopments are considered the firsttime the law has had such an effect.“It’s a new paradigm,” said EMWDBoard Member Randy Record. “It’snot water saying ‘we’re here for you,’but ‘You have to do this for us,’”reported the Press-Enterprise.Visit www.pe.com and www.mwdh2o.com.New Mexico Senate ConsidersRegulation of Deep AquifersJust as developers are realizing thepotential of using deep, brackishgroundwater—currently unregulated—tosupport growth in New Mexico (seeSouthwest Hydrology, March/April2008), legislators began thinking thatregulation of that resource is warranted.Senator Carlos Cisneros of Questaintroduced SB 262 to the New Mexicolegislature earlier this year, calling forregulation of aquifers having “reasonablyascertainable boundaries” with uppersurface 2,500 feet or more below theground and dissolved solids concentrationsgreater than 1,000 parts per million.Deep groundwater produced during oil andgas exploration or geothermal projects isalready regulated through the New MexicoEnergy, Minerals, and Natural ResourcesDepartment (EMNRD), although SB 262proposed additional restrictions.The bill did not pass, having facedopposition by EMNRD and the StateLand Office, according to the Santa FeNew Mexican. However Cisneros toldthe newspaper that he plans to evaluatethe opposing arguments and returnwith a new version of the bill in 2009.Supporters said that significant amounts ofgroundwater pumping at any depth shouldbe monitored by the state engineer. Fornow, the developers are getting busy…Visit www.nmsenate.com andwww.santafenewmexican.com.A division of Ruekert|Mielke,Inc.262.542.5733 • www.aquiferscience.com12 • May/June 2008 • Southwest Hydrology

New Mexico and Texas Burythe HatchetIrrigation districts in Doña Ana County,New Mexico, and El Paso, Texas,have reached what Elephant ButteIrrigation District (EBID) ManagerGary Esslinger calls “a monumentalagreement” on the apportionment ofwater from the Elephant Butte Reservoir,according to an Associated Pressreport in the Las Cruces Sun-News.In February, the districts, which togethercomprise the Rio Grande Project, agreedto drop their separate lawsuits over waterrights, following a 29-year dispute,said the AP report. El Paso CountyImprovement District No. 1 had claimedthat unregulated groundwater pumpingby New Mexico farmers was cutting intotheir share of reservoir water. Under theagreement, EBID will guarantee deliveryof the El Paso districts’ water to the stateborder, and the New Mexico farmers cancontinue to pump groundwater as long asthe El Paso delivery requirements are met.Visit www.lcsun-news.com.Division Over Rio Grande WatersA 1944 treaty that equally apportionsRio Grande waters to Mexico and theUnited States is proving inadequate toresolve disputes on both sides of theborder. Under the treaty’s terms, waterallocations to Texas farmers were severelycurtailed from 1992 to 2002 becauseof low waters in the shared Amistadand Falcon reservoirs, with Mexicoaccumulating a deficit of 1.5 million acrefeetby the end of that period. The debthas been gradually repaid through watertransfers from the dams every five years.Farmers in northeastern Mexico arehurting and unhappy from the latesttransfers, reported Reuters, and lawmakersin Tamaulipas have asked the MexicanSupreme Court to rule on whether themost recent transfer, in 2007, was lawful.The farmers claim their harvests are ruinedand farms must be abandoned every timea transfer is made. They argue that waterfrom six western Mexican tributaries tothe Rio Grande should be used instead toreduce the deficit, according to Reuters.Meanwhile, the state of Texas has joinedfarmers, ranchers, and irrigation districtsin continuing to seek redress from Mexicofor uncompensated damages racked upfrom 1992 to 2002. Because individualscannot sue Mexico or the United Statesunder the 1944 treaty, the farmers suedMexico for $500 million through atribunal of the North American Free TradeAgreement in 2004. The case was thrownout because NAFTA ruled it did not havecontinued on next pageMay/June 2008 • Southwest Hydrology • 13

GOVERNMENT (continued)jurisdiction. The farmers are particularlyfrustrated by the U.S. State Department’slast-minute decision to side with Mexico,according to the Associated Press.AP reported that the farmers plannedto take their case to a Canadian judgeto decide whether they received a fairhearing. They are seeking a decision froma Canadian judge because both sides hadagreed to arbitration at a neutral locationif the issue could not be resolved.Visit www.ap.org and www.reuters.com.Oil Shale Development a Threatto Colorado’s Water?International oil companies havesubstantial and growing water rights onthe Western Slope of the Rocky Mountainsand could be planning to use the rightsfor oil-shale development, according to anarticle in the Durango Herald. Evaluatingpotential impacts of industry developmenton the Colorado River is difficult becauseof a lack of studies on oil shale productionand water needs. Most studies arevague, 20 years old, and do not reflectnew in-situ development techniques.But three major oil companies—Shell,Chevron, and EGL—recently obtainedleases to demonstrate their in-situ methodson 160-acre parcels in Colorado. Thetechnique requires water to process theshale oil, control dust, and wash leftoveroil from underground formations.According to the Herald, while Chevronhas the biggest water rights in Colorado,Shell has done the most aggressivepurchasing in the last five years, includinga ranch in northwest Colorado withthree large reservoirs, a land swap forPiceance State Wildlife Area, and anarea west of Grand Junction adjacentto a coal mine. Shell is not divulgingwhether the purchases are for its oil-shaleresearch project, the newspaper said.The prospect of substantial oil-shaledevelopment has some legislators andenvironmentalists worried, said theHerald. Potential water use estimatesrange up to 500,000 acre-feet per year.Colorado currently uses around 2.1 millionacre-fee per year from the ColoradoRiver Basin. The state’s entire allocationof Colorado River water is 3.8 millionacre-feet—a figure most water expertsconsider will never be available becauseof climate fluctuations and change.A Shell spokesperson, Jill Davis, believesconcerns are exaggerated. She estimatesproduction of oil from shale would taketwo to three barrels of water per barrelof oil produced and believes that workforce, air quality, the oil market, and watersupplies will all be factors limiting theindustry’s size, according to the article.Visit www.durango.herald.EPA Calculates $202 Billion Billfor InfrastructureA recent report from the U.S.Environmental Protection Agencyestimates $202.5 billion in capitalinvestment is needed nationwide tocontrol wastewater pollution for upto a 20-year period. EPA conducts theClean Watersheds Needs Survey everyfour years; the new report is based ona 2004 survey. The estimate includes$134.4 billion for wastewater treatmentand collection systems, $54.8 billion forcombined sewer overflow corrections, and$9 billion for stormwater management.The report provides information aboutpollution control needed to meet theenvironmental and human healthobjectives of the Clean Water Act. Thefigures represent documented wastewaterinvestment needs, but do not accountfor expected investment and revenues.Wastewater treatment utilities pay forinfrastructure using revenue from ratescharged to customers and may financelarge projects using loans or bonds.State and federal funding programs, suchas EPA’s Clean Water State RevolvingFund program, are also available tohelp communities meet their wastewaterpollution control needs. The needs inthis survey represent a $16.1 billion (8.6percent) increase over the 2000 surveyreport. The increase is due to populationgrowth, more protective water qualitystandards, and aging infrastructure.Visit www.epa.gov/cwns/.Los Angeles ReservoirsExperience Bromate SpikeLate last year, Los Angeles Departmentof Water and Power (LADWP) officialsdiscovered unusually high concentrationsof bromate in two reservoirs within itswater distribution system. The reservoirs,which collectively held 600 milliongallons of water, were immediatelyisolated from the rest of the system.According to the Los Angeles Times,bromate concentrations measured inOctober were 68 parts per billion (ppb)and 106 ppb in the two reservoirs. TheU.S. EPA drinking water standard forbromate is 10 ppb calculated as an annualaverage of monthly measurements.Because the problem was addressedsoon enough, no violations occurred.Bromate is a suspected carcinogen thatmay cause adverse health effects afterlong-term exposure. It is known to formas a disinfection byproduct in public watersystems when water containing naturallyoccurring bromide is purified using ozone.The LADWP reservoirs were being filledwith local groundwater, and accordingto the agency’s report, bromate formedunexpectedly when the reservoir waterwas treated with chlorine and exposedto sunlight. This was the first time suchan occurrence had been observed.After using some of the reservoirwater for nonpotable uses, LADWPplanned to drain and thoroughly cleanthe reservoirs. They are slated to beback in service by this summer.Visit www.ladwpnews.com and latimes.com.14 • May/June 2008 • Southwest Hydrology

An ASR PrimerCortney C. Brand – R.W. Beck Inc.streambedvadosezone wellrecharge basinsvadose zonerecharge/recoverywellThat Which We Call ASR...…others may not. In preparing this issue,Southwest Hydrology polled numerousexperts for the best term to describethe process of recharging aquifers (by avariety of means using a variety of sourcewaters), storing water (for short to longperiods), and then recovering water (fromthe same or other wells). We receivedmany opinions and no clear consensus.The top candidates, none of which include“recharge,” “storage,” and “recovery,” are:Aquifer Storage and Recovery (ASR):To some, this means strictly rechargeand recovery from the same well. Othersbelieve it is the most widely recognizedterm—at least in the Southwest—to referbroadly to all forms of aquifer recharge,storage, and recovery.Managed Aquifer Recharge (MAR):Has the greatest international use; lesscommon in this country. The originaldefinition referred to intentional bankingand treatment of water in aquifers.Managed Underground Storage ofRecoverable Water (MUS): Introduced in2008 by NRC’s Committee on SustainableUnderground Storage of RecoverableWater to define “purposeful recharge ofwater into an aquifer system for intendedrecovery and use as an element of longtermwater resource management.”Southwest Hydrology is using the broaddefinition of ASR.Most water resourcesprofessionals have heardof ASR, or aquifer storageand recovery, but it can mean differentthings to different people. ASR can meanartificial recharge, groundwater recharge,managed aquifer recharge, undergroundwater storage, conjunctive use, or acombination thereof. For purposes ofthis and accompanying articles, ASRis a water management technique thatencompasses the purposeful rechargeand temporary storage of water in anaquifer with the intent to recover all ora portion of the water from the sameaquifer in the future. Without the intentto, or act of, recovering recharged waterit is simply groundwater recharge.ASR is thought to have originated severalhundred years ago in the Kara Kum Plainof Turkmenistan and in Western India(Pyne, 1995), but is now conducted insome form on every continent exceptAntarctica. The motivators and potentialbenefits of ASR vary based on geography,hydrology, water chemistry, and waterpolicies/laws. A majority of the Southwestis arid or semi-arid, susceptible todrought, and characterized by declininggroundwater levels, unreliable surfacewater supplies, and overappropriatedrivers. As a result, the capture and storageof water when it is available is criticalto sustainable water management. Thetraditional approach has been to store wateraboveground by constructing dams andreservoirs. The benefits of abovegroundstorage include rapid fill and release,large storage capacities, straightforwardmeasurement and management, andopportunities for recreation. However,escalating costs and environmentalpermitting requirements associated withsurface reservoirs, as well as decliningavailability of land and suitable sites, havedriven water professionals to explore ASRas an alternative.Implementing ASRWhere feasible, storing water undergroundcan save money, increase yields, mitigatethe impacts of drought, firm up surfacewater supplies, improve water quality,and avoid evaporative losses. Thenecessary ingredients are 1) an aquiferof suitable character, 2) source water ofsuitable quality, 3) the means to transmitthe source water into the aquifer, and4) the means to recover it. ASR can beaccomplished in bedrock, alluvial, orlimestone aquifers as long as the formation16 • May/June 2008 • Southwest Hydrology

can receive, store, and transmit waterwithout adversely impacting nativegroundwater or source water quality.There are myriad configurations andmethods of implementing ASR, and theinherent variability of natural systemsnecessitates site-specific solutions.Suitable source waters can include surfacewater diverted from streams, stormwaterrunoff, remediated groundwater,reclaimed water, and industrial-processwater. Water can be transmitted intoan aquifer using nonstructural meanssuch as natural drainages or structuralmeans such as impoundments, basins,trenches, injection wells, vadose zonewells, or combinations thereof. SomeASR systems, because of the nature ofthe water source, require abovegroundstorage to capture and hold water beforeit can be transmitted underground. Waterrecovery is typically accomplished throughwells; however, some ASR systems utilizenatural discharge of groundwater to astream as a virtual means of recovery.ASR is practiced by governmentalentities and water utilities throughoutthe Southwest. Some familiar examplesinclude Scottsdale, Tucson, Orange County,Las Vegas, El Paso, Salt River Project,Central Arizona Project, and MetropolitanWater District of Southern California(MWD). Most of these entities utilize thevast storage capacity available in alluvialfillbasins. In contrast, entities situatedalong Colorado’s Front Range, includingHighlands Ranch and Colorado Springs,utilize deep bedrock aquifers of the DenverBasin. The City of San Antonio utilizes theEdwards Aquifer, a cavernous limestoneformation. Other examples of ASR includewater conservation districts in the San LuisValley and the lower South Platte Riverin Colorado, the Wintergarden region ofsouth Texas, and the Jordan Valley WaterConservancy District in central Utah.As illustrated in the table below, theseprojects vary in their objectives, watersources, aquifer characteristics, and meansof recharging and recovering water.Challenges to OvercomeAlthough the potential benefits of ASRare numerous, ASR also poses significantchallenges. These primarily revolvearound issues of water quality; waterrecovery; the management, monitoring,and accounting of recharged water; waterrights; and source water availability.These challenges are geographicallydependent due to interstate and intrastatevariations in water administration, localhydrology, and aquifer characteristics.ASR is typically accomplished usingwater derived from a source other than thereceiving aquifer. Waters from differentsources can have different chemistries,pH, temperatures, and redox conditions.Mixing dissimilar waters undergroundand exposing aquifer materials to nonnativewater can drive geochemicalreactions that alter water chemistry. Somepotential impacts include dissolution ofarsenic compounds and precipitation ofclays. Water quality changes can alsooccur as water percolates through thevadose zone and encounters evaporitedeposits or leaching zones underlyingagricultural areas. Recharged water canacquire salts and nitrogen compounds asit percolates to groundwater, degradingsource water and groundwater quality.The increased use of reclaimed waterfor ASR has created an emerging waterquality issue posed by pharmaceuticals andendocrine disrupting compounds. Thesecontaminants occur in wastewater at verylow concentrations and are not effectivelysee ASR Primer, page 32Entity / Project Objective Water Source Aquifer Type Recharge Method Recovery MethodArizonaCity of Scottsdalestore excess surface water and stormwater treated CAP water, reclaimed water alluvial basin direct injection wells, production and dual-use wellsrunoffvadose zone wellsSalt River Project store excess surface water CAP water, surface water (Salt and Salt River basinsto be determinedVerde rivers), reclaimed water alluviumCentral Arizona Project (CAP) store excess surface water CAP water alluvial basin basins to be determinedTucson Watertreat and store surface water and reclaimed CAP water, reclaimed water alluvial basin basins production wellswaterVidler Recharge Facility store surface water CAP water alluvial basin basins, vadose zone wells to be determinedCaliforniaOrange County Water District long-term storage, groundwater surface water (from MWD), alluvial basin direct injection wells, inlieu,production wellsreplenishmentstormwater runoff, reclaimed waterbasinsCoachella Valleylong-term storage, groundwater surface water (from MWD), All- alluvial basin in-lieu, basins production wells, water transferreplenishmentAmerican CanalTexasCity of El Paso recharge aquifer and store water reclaimed water alluvial basin direct injection wells, basins production wellsCity of San Antoniostore seasonally available Edwards Aquifer groundwater alluvial basin direct injection wells production wellswaterWintergarden Groundwater enhance recharge to the Carrizo aquifer stormwater runoff sandstone impoundments, passive production wellsConservation DistrictwellsColoradoCentennial Water & Sanitation store excess surface water surface water (S. Platte River) sandstone direct injection wells production and dual-use wellsDistrictColorado Springs Utilities store excess surface water surface water (Colorado River) sandstone direct injection wells dual-use wellsLower South Platte Water streamflow augmentation, wildlife recovery surface water (S. Platte River) and S. Platte River basins and ditches accretion to riverConservancy Districtalluvial wellsalluviumNevadaLas Vegas Valley Water District store excess surface water surface water (Colorado River) alluvial basin direct injection wells production and dual-use wellsExamples of ASR projects in the Southwest. Note: CAP water is untreated Colorado River.May/June 2008 • Southwest Hydrology • 17

Hydrogeology and ASR DesignGreg Bushner – Vidler Water CompanyToday there are many choicesfor the design and operation ofan aquifer storage and recovery(ASR) facility, since such facilitiescan serve a variety of needs. An ASRfacility has the capability to recharge,store, and recover all or a portion of thesource water recharged regardless ofthe recharge method. It might consistof shallow or deep infiltration basins,vadose zone wells, direct injection wells,wells that can both inject and recoverwater, or a combination thereof.Evaluating Land and WaterThe selection of a facility initially isdriven by the available source water,available or needed land, and theplanned end use of the water. What isthe source water? It may be wastewatereffluent, seasonal surface water, vested orcertificated water rights, or another watersource. Once identified, its chemistrymust be evaluated to determine if itwill need pretreatment or if the qualityis adequate for the project method.Next, how much land is needed and ofwhat type? A vadose zone, injection,or dual-use (recharge/recovery) wellin an urban setting has a significantlysmaller footprint than an infiltrationbasin; however, the unit land costmay be much higher. How will thefacility design be incorporated into theavailable land or vice versa? Is the landundeveloped or has it been disturbed?Finally, what is the end use of thestored water—what type of recharge/recovery cycle will be needed?How long will the water be storedbefore it is recovered, and howwill it be accounted for untilit is recovered? Answeringthese questions will guidethe project design andbudget through thenext phases of projectplanning. A life-cycle cost analysis isalso useful to determine the appropriaterecharge method and its application toa specific project and water source.Now the HydrogeologyNo matter what type of recharge methodis decided upon, all ASR projects requirecharacterization of the hydrogeologicconditions in the vicinity of the projectsite. This begins with identifying theland use and land owners, and anyexisting wells and their use, proximityto the project site, water source,conveyance options, and water quality.Baseline hydrologic data are critical topredict future impacts from the project.These data should include a water-levelelevationcontour map showing directionof groundwater flow and hydraulicgradient, and determination of storagecapacity or transit capacity of the vadosezone. Are water levels at surrounding wellsincreasing, decreasing, or both? Areasof subsidence should be mapped relativeto the project location. Baselinegroundwater chemistry data should becollected if they are not already available,and constructing one or more projectmonitoring wells may be warranted.Data NeedsDepending on the type of recharge methodto be used, additional hydrogeologicdata may be needed. Infiltration basinfacilities require a detailed investigationof the surficial soils and vadose zone.Soil samples should be analyzed forlithologic characteristics such as grainsize, distribution, intrinsic permeability,residual moisture content, and pore-waterchemistry. A similar investigation shouldbe conducted in the vadose zone throughuse of soil borings strategically locatedto represent site conditions for the projectarea. The goal of this investigation is toidentify positive attributes of the soils andvadose zone, such as high porosity andpermeability that would be conducive fora particular recharge method, as well asnegative attributes such as the presenceof subsurface impermeable layers orAerial view of the Vidler Recharge Facility, aprivately-owned project in western Arizona thatcontains over 460 acres of surface infiltration basins.Photo: Kenney Aerial18 • May/June 2008 • Southwest Hydrology

contaminants. Site-specific tests usinginfiltrometers should be conducted, aswell as field-scale infiltration tests todetermine initial and long-term infiltrationrates for use as facility-design parameters.Borehole percolation tests may alsobe used to develop a vertical hydraulicconductivity profile of the vadose zone.Initial infiltration rates for rechargethrough basins in Arizona have been foundto range from about one foot per day tomore than 12 feet per day, dependingon site conditions. However, theserates may decrease by one-half to twothirdsduring actual facility operations.Initial testing and site characterizationare important for determining projectfeasibility, but only long-term projectoperations provide true infiltration ratesthat determine the project’s viability.Sampling and chemical analysis of porewater and soils can identify potentialconstituents that, once the facility isin operation, could migrate due towater infiltration. For example, nitratesare known to occur in pore water ofundeveloped arid soils. Operationof an ASR facility might mobilizethem, resulting in a concentration ofnitrates at the groundwater interface.Knowing the potential for migrationof a constituent prior to facilityconstruction is beneficial so that otheralternatives, such as use of a differentrecharge method, can be considered.Test to TargetSimilar data should be collected to identifytarget injection zones for vadose zonewells, if that recharge method is chosen.For direct injection and dual-use wells,standard hydrogeologic characterizationof the aquifer system is needed. Thisincludes a lithologic description ofthe drill cuttings and a full suiteof geophysical logs. In addition,aquifer testing and determinationof hydraulic properties, includingtransmissivity, storagecoefficients, and hydraulicconductivity should beconducted once the well isconstructed and the aquiferwater chemistry analyzed.Monitor wells should be installed aspart of this effort, initially to determineThe development ofbaseline hydrologicdata is critical topredict future impactsfrom the project.the viability of the aquifer system,subsequently for use during the testingof the injection/dual-use well, and finallyduring facility operations to monitorwater level and chemistry, and as aregulatory point of compliance if needed.Regardless of the recharge method used,the receiving aquifer system needs to beunderstood so that the potential effects ofrecharge to the system can be discerned.Plan on MaintenanceMaintenance and operational issuesfor ASR facilities include mechanicalplugging such as air entrainment,conveyance system dry-ups ormaintenance, and other issues includingbiofouling. Biofouling is an allencompassingterm that pertains to allorganisms that can cause a reduction ofinfiltration or injection rates. Correctidentification of biofouling agentsis imperative in order to devise aneffective treatment plan. Biofouling canalso occur in the form of algal mats orclogging layers in basins. Maintenanceof affected facilities would include dryoutsand scarification of the basins toremove clogging materials, and welldevelopment or redevelopment for vadosezone, injection, and dual-use wells.Careful thought and planning arenecessary to develop a successful ASRproject. Source water characteristicsand amount and type of available landguide the initial design and type ofrecharge facility to be constructed.But hydrogeologic characterizationultimately determines the feasibilityof the project, the design criteria, andthe project’s long-term viability.Contact Greg Bushner at GBushner@vidlerwater.com.May/June 2008 • Southwest Hydrology • 19

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

Corps Central Everglades RestorationPlan. Individual water entities such asSouth Metro (Colorado) Water Authorityand the cities of Phoenix and Beaverton,Oregon, have developed methods forcomparing benefits and costs of storageoptions, supporting more integratedplanning approaches. When agenciessuch as Corps and Reclamation aredeveloping basinwide and regional waterplans to meet national priorities, suchas ensuring water is left in streams topreserve habitat, will all opportunities forstorage (surface and underground) andconsiderations of conjunctive water usebe incorporated as critical componentsfor optimal water management?Other federal agencies, such as thosethat own land with potential rechargesites or are involved with waterintensiveactivities, also are interestedin underground storage. In Colorado,the National Resources ConservationService and U.S. Fish and WildlifeService have funded and supportedprojects on state wildlife areas andprivate lands where recharge ponds forstream augmentation provide habitatbenefits. The U.S. Department of Energyis currently exploring increased useof treated effluent and water producedduring energy extraction. In Wyoming,water providers have completed pilotstudies on produced-water ASR. Willfederal agencies consider and incorporateunderground and surface storage optionsand conjunctive management for federalactivities involving water storage?Building a National NetworkThe NRC forum was the first nationalmeeting on ASR institutional issues. Waterproviders and state agencies from acrossthe country want this dialogue to continuewith the benefit of widely accessiblestatistics, metrics, policy and facilityprofiles, and case studies. A nationalnetwork of ASR water providers, agencypersonnel, and other stakeholders is beingconsidered, which would work withexisting water education organizations andassociations that consider ASR an issueof interest to their members. The networkcould improve communication betweenASR systems and regulatory programs,make reliable information more widelyavailable, develop statistics on nationalASR use, and further national dialogueon policy, permitting, and planning.Contact Cat Shrier at cat@watercatconsulting.com.Read or purchase NRC’s “Prospects for ManagedUnderground Storage of Recoverable Water”(National Academies Press, 2008) at books.nap.edu/openbook.php?record_id=12057&page=R1.VIEW THE WEBCAST of NRC’s March19, 2008 Forum on Policy, Regulatory,and Economic Issues Associated withManaged Underground Storage ofRecoverable Water for no charge untilJune 30. Link through these partnerorganizations:• National Ground Water Association(www.ngwa.org)• Groundwater Resources Association ofCalifornia (www.grac.org)• Ground Water Protection Council(www.gwpc.org)An intensive two-day short courseImproving Your Personal and Project Management SkillsLocation:University of California,BerkeleyDate:September 24 & 25, 2008Instructors:Bill TrubyTruby Achievement CenterJoann TrubyTruby Achievement CenterDan KelleherEarth Tech, Inc.midwestGEOSCIENCESwww.midwestgeo.com groupfor Environmental and Engineering Projects"promoting geological sciences through continuing education"Managingory, and computer analysis placesunique demands on project managers for environmental and engineering projects . Despite meetingschedule and budget, you might often have felt pressure to get more from yourself and your team,and that you could have been more successful in developing client relationships to achieve bettermanagers that will enable you to learn - and practice - new project management skills designed toYou'll gain a clear understanding of why the art ofdelegation is so important for projectproviding a context of the work in the overall project strategy, providing the necessary material so thatthe delegee can complete the task, and guidance as to what is expected and how it is to be presentedfor your subcontractors, clients and your supervisor.“The communication tools apply to all fields and makeproject tasks easer”-Rachael Berthiame, V3 Consultants16 Contact Hours1.6 CEUsAnd you'll discover how your individualEverything I learned in this class will be beneficial to me personally,my co-workers, my company, my clients and my projects.I highly recommend this course to any project manager.- Karen Kajenke, Environmental Assessment & Remediation, Inc.Register Now at:www.midwestgeo.comMay/June 2008 • Southwest Hydrology • 21

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

Photo: Gary Ginprotection because so many sources ofgroundwater pollution are inadequatelyregulated by either federal or stategovernments. Pollution from mining,energy production, and agriculture, forexample, can be politically difficult forstates to regulate when they are competingto attract such industries. States do notcompete for ASR projects, however, andI am aware of no evidence that the statesare failing to adequately regulate them.Furthermore, groundwater pollutionrisks posed by ASR projects appearminimal compared to many other projects,thus they would seem to offer a goodopportunity to allow states to functionas the “laboratories of democracy.”Water QuantityState control over the use of water iswell-established. Federal issues doarise, as for example, when federalfunds are used for an ASR project, orwhere federally owned water rights areproposed as the source water. However,each state’s water regime varies, andsome states do not clearly address thewater rights issues raised by projects.ASR projects must own or have a rightto control the water that is used forrecharge. Effluent, one possible sourcewater, is not necessarily owned by theentity that wishes to recharge the aquifer.Critical questions about control of theaquifer are whether the project can useaquifer space for storage and whether therecharger has control of the water that ithas put into the aquifer. Generally, a stategovernment would expect to be able touse an aquifer for storage without a clearlegal basis to do so, but the use of aquiferstorage space becomes a thorny legalproblem when there are multiple entitiespumping groundwater in the aquifer. Thelegal questions would be most pointedif a commercial entity proposed such anoperation in an aquifer. In any event, theright to use the capacity of an aquiferfor storage will have to be resolved bystatute or under the common law.Another set of legal concerns arisesfrom how to protect the investmentin the water that has been rechargedwithout harming other entities that maybe extracting water from the aquifer.Where multiple entities utilize an aquifer,The greatest conflictsseem to be overthe degree of waterquality protectionrequired for aquifers.explicit legal guidance or contractsamong the groundwater users would benecessary. Finally, there are potentialliability concerns should a project causeimpairment of another’s water rights.This list of legal concerns mightseem daunting and a testiment to thedesirability of statutory and regulatoryschemes that respond to the particularissues raised by ASR projects. Despitethe complicated nature of these projects,the NRC report contains discussions ofhow institutional challenges have beenovercome in different jurisdictions.Future Looks FavorableWater projects always are complicated,requiring knowledge of both written andunwritten rules and the capacity to easethe way through innumerable barriers.ASR projects are viewed as extraordinarilycomplex by some, but the successfulimplementation of these projects suggeststhat these barriers can be overcome. Thereare no comprehensive studies of howmany technically worthwhile projectsfailed due to institutional barriers.A number of factors favor the future ofASR projects. Organized opposition tothem by citizen organizations seems to belacking, except when treated wastewateris proposed for drinking water reuse.Among the choices for water storage,ASR appears to be one of the most benign,since storage underground does not affectriver function and it decreases evaporationlosses. ASR may even provide ancillaryenvironmental benefits. Environmentalrisks exist, but perhaps have been betteraddressed than many others associatedwith water, such as unregulatedpesticide runoff, the effects of oil andgas operations, and even leaking septicsystems. A well-thought-out regulatorysystem, providing appropriate informationabout risk, opportunities for publicparticipation, and appropriate regulationshould allow this technology to be utilized.State governments should consideradopting regulatory regimes thatspecifically address the issues raisedby ASR. Doing so lessens transactioncosts and provides a more tailoredreview of issues that arise with respectto these projects. I suggest that it isappropriate for the federal governmentto assist by providing researchfunding and for state governments tocooperate in devising templates forregulation, within the constraints ofeach state’s unique water code.Contact Denise Fort at fortde@law.unm.edu. Reador purchase “Prospects for Managed UndergroundStorage of Recoverable Water” (National AcademiesPress, 2008) at books.nap.edu/openbook.php?record_id=12057&page=R1.May/June 2008 • Southwest Hydrology • 23

Water Quality Changes During Subsurface StoragePeter Fox – Arizona State UniversityWhile underground storage ofwater offers many benefits,transformations in waterquality resulting from the recharge ofone type of water into an aquifer ofdifferent composition warrant attention.The primary constituents of concern thatmay be introduced into or form in storagesystems include organics and pathogens;nutrients and inorganics can also causeproblems. These constituents may bebroken down, mitigated, or otherwisechanged through chemical, biological,adsorption, dilution, or filtration processesthat take place in the storage zone. Theextent to which these processes occurdepends on the compositions of the twowater types and the subsurface conditions.Time, Surface Area Are FactorsSome water quality transformations occurrapidly, such as those that result fromchanges in oxidation-reduction (redox)conditions or chemical interactionsbetween the injected water and the aquifer.These reactions may not only changethe water quality but also impact thehydraulic capacity of injection wells.Other transformations, such as thebiodegradation of trace organiccompounds, often occur slowly; sufficienttime is required to achieve the full benefitsof aquifer storage. For7.0example, with enoughtime, natural attenuation6.0processes can improve5.0the quality of storedwater to that approaching 4.0native groundwater.DOC (mg/L)Alluvial aquifers, comprisedmostly of sand and gravel,contain abundant surfacearea, which permits plentyof contact with the watertraveling through it. Thissurface area mediates manybiogeochemical reactions thatcan improve water quality. Suchwater quality transformationsare less likely in fractured and3.02.01.00.024 • May/June 2008 • Southwest Hydrologykarst aquifers where preferential flowthrough cracks and fissures limits contactbetween the water and aquifer material.A select group ofSOCs has beenfound to persist inthe subsurface, andthe list is growing.Flowpaths also affect transformationsduring subsurface storage. Flowpathssurrounding dual-purpose wells—usedfor both injection and recovery—havehighly variable travel times and themost unpredictable effects on waterquality. Subsurface storage systemswith different recharge and recoverypoints can have defined flowpaths andassociated travel times. Such systemshave more consistent and predictablewater quality transformations.Oxygen Matters AlsoMany organics, nutrients, and pathogens ofconcern can be removed in the subsurfacethrough biological mechanisms. Keyfactors that affect biological removalduring subsurface storage include thebiodegradable organic carbon content of0 2000 4000 6000 8000 10000 12000 14000 16000Distance downgradient (feet)Dissolved organic carbon (DOC) concentration is shown as afunction of distance for the Mesa (Arizona) Northwest WaterReclamation Plant groundwater recharge basins. Each 1,000 feetof travel equals around six months of travel time. After severalyears of travel, DOC concentrations are less than 1 milligram perliter, approaching background conditions of the aquifer.the recharge water and redox conditionsof the aquifer. Therefore reverse-osmosistreatedwater, lacking organic carbon,does not support significant biologicalremoval. In fact, trace constituents suchas N-nitrosodimethylamine (NDMA)have been shown not to attenuate duringthe injection of reverse-osmosis-treatedwater, unlike in other recharge systems.Most biological transformations will occurwhether or not oxygen is present, however,some organic compounds require a specificelectron acceptor to degrade. Manychlorinated organic compounds, such astrihalomethanes, degrade faster underconditions where oxygen is low or absent.Finally, recharging waters high in oxygendemand will create anoxic conditions andincrease the potential for the dissolutionof mineral iron and manganese.The Organic PlayersThree types of residual organic materialsundergo transformation: natural organicmatter (NOM), which is present inmost water supplies; soluble microbialproducts (SMPs) formed during thewastewater treatment process from thedecomposition of organic compounds,and synthetic organic compounds (SOCs)added by consumers and also generatedas disinfection byproducts (DBPs) duringwater and wastewater treatment(Barker and Stuckey, 1999).Most waters contain NOM; reclaimedwaters contain a mixture of NOMand SMPs. NOM and SMPsmeasured together as dissolvedorganic carbon have concentrationstypically measured in the milligramsper liter range. The primary concernover NOM and SMPs is theirpotential to form DBPs and stimulatebiological growth in distributionsystems. Concerns over bothhuman and aquatic health effectsare generally associated with SOCsand DBPs, which are measuredindividually at concentrations ofmicrograms or nanograms per liter.

Subsurface Removal of OrganicsOrganic compounds are removed duringsubsurface storage by a combination ofbiodegradation, filtration, sorption, andoxidation/reduction. Biodegradation isthe most sustainable removal mechanismfor organic compounds during subsurfacetransport. Concentrations of NOM andSMPs are reduced during subsurfacetransport as high molecular weightcompounds are hydrolyzed into lowermolecular weight compounds, whichserve as substrate for microorganisms.As NOM and SMP concentrationsdecrease, their potential for formingDBPs also decreases. Given sufficientsurface area and contact time, the storedwater may approach the quality of nativegroundwater with respect to organiccarbon content (see figure, below left).However, a select group of SOCs hasbeen found to persist in the subsurface,and the list is growing as newanalytical techniques are developed.In the Netherlands where Rhine Riverwater has been recharged for over acentury, recharged groundwater canbe dated by the presence of persistentpharmaceutical compounds during thelast five decades. The persistence ofcarbamezapine (an anticonvulsant andmood-stabilizing drug) is so widespreadthat researchers have suggested its useas a universal indicator of anthropogeniccontamination. These compounds areall polar and resist biodegradation,making them both mobile in the aquiferand persistent. In contrast, the steroidhormones and alkylphenols suspectedof causing estrogenicity are nonpolarand biodegradable, and have beenobserved far less frequently in aquifers.The Fate of PathogensAlluvial recharge systems effectivelyfilter bacteria and protozoa, leavingviruses as the major concern for pathogentransport during subsurface flow. Infact, the survival of viruses has beenused as travel-time criteria for systemsdesigned for potable water production.In California, the minimum travel timerequirement is six months, while 50 and70 days are required in Germany and theNetherlands, respectively. Higher levels ofmicrobial activity in an aquifer decreasethe survival of pathogenic viruses sincethe viruses are subject to predation. Thisis one reason for the discrepancy betweencriteria in different parts of the world.NutrientsRecharge systems have limited potentialfor the removal of nutrients. Biologicalprocesses may sustain the removal ofnitrogen species under specific conditions.The addition of ammonia in secondaryeffluent to surface recharge basins canresult in significant nitrogen removal sincecyclic aerobic/anoxic conditions will resultfrom the use of wetting/drying cycles. Theadsorption of ammonia is dependent onthe cation exchange capacity of the soils.Some adsorbed ammonia is convertedto nitrate under aerobic conditions andthe nitrate can be reduced to nitrogengas under anoxic conditions. Adsorbedammonia may also serve as the electrondonor to reduce nitrate by anaerobicammonia oxidation. Removal rates of70 percent have been observed at theTucson Sweetwater Underground Storageand Recovery system. Direct injectionsystems may remove some nitrate if theaquifer is anoxic and the potential forammonia oxidation is low since thereis insufficient oxidation. Phosphorouscan be removed by precipitation oncalcerous soils for time periods thathave been estimated to be centuries,but the removal is not sustainable.InorganicsSimilar to phosphorous, inorganics maybe removed by precipitation or as aconsequence of changes in their redoxstate. Most waters, including reclaimedwaters, that are used for recharge donot contain inorganics at concentrationsthat cause concern. As long as thewaters applied do not contain elevatedconcentrations, they should equilibratewith the local geochemical conditionsand not pose a problem. However, rapidlychanging redox conditions that can occurin dual-purpose wells can create bothdissolution and precipitation of naturallyoccurring iron, manganese, and arsenic.Such conditions can result in wellplugging and contamination of recoveredwater. It is necessary to inject a sufficientquantity of water to create a storage zonethat eliminates the recovery of water thatis subject to varying redox conditions.Contact Peter Fox at Peter.Fox@asu.edu.ReferenceBarker, D.J., and D.C. Stuckey, 1999. A reviewof soluble microbial products (SMP) inwastewater treatment systems, Water Resour.Res, 33: 3063-3082.SustainabilityIt’s a Southwest necessity.Together we can attain it.• Groundwater resource evaluation and basin inventory analysis• Modeling of groundwater and surface water flow systems• Wellhead and aquifer source protection• Assured water supply planning and development• Litigation support for water rights and resource damage• Water quality evaluation and treatment (including arsenic)For more information, contact Brad Cross at 480.905.9311or via e-mail at brad.cross@lfr.com.LFR Inc. is an environmental management & consulting engineering firm with 29 offices nationwide. For moreinformation, call 800.320.1028 or visit us at www.lfr.com.May/June 2008 • Southwest Hydrology • 25

What About the “R” in ASR?Betsy Woodhouse – Southwest Hydrology, University of ArizonaSouthern Nevada Water Authority ASR wellGetting water into the ground isfairly straightforward: water drainsdown from a basin or goes downa well. But then what happens to it? Willthe water really be there when it’s needed?Does it matter if the exact same water isthere to recover? Was water actually stored?The answers depend on the goals of theproject and the local regulatory framework.When fresh water is stored in saline orbrackish aquifers, common in the Southeast,mixing of the waters is undesirable: thegoal is to recover essentially the same waterthat was recharged. When fresh water isstored in fresh-water aquifers, as is typicalin the Southwest, recovering the same wateris less critical. The goal of such projectsmay be to reverse water level declinesin the aquifer or to store water long-termfor future drought or development.What Storage MeansFrom a physical standpoint, water mustremain in a location that is definable andaccessible for recovery in order to beconsidered “stored.” Rising water levelsin wells demonstrate that the volume ofwater stored in an aquifer is increasing.The Vidler Water Company has beenrecharging about 30,000 acre-feet peryear of Central Arizona Project waterSometimes recoveryof an equivalentmass matters morethan getting the samemolecules back.in its spreading basin facility in westernArizona since 2000; nearly a 200-foot risein water levels has been observed. TheSouthern Nevada Water Authority storeswater in a highly transmissive confinedaquifer that also is used by other entities. Itoperates on a seasonal cycle, storing waterduring the wet months when demand islow (and natural recharge also replenishesthe aquifer) and pumping it during drymonths. Water levels fluctuate 35 to 40 feetbetween the two seasons, of which 13 to18 feet are attributed to artificial recharge.Permeability tests, tracer experiments(primarily using chloride), and flowand transport models have been used tostudy the behavior of recharged water inan aquifer. In general, recharged waterusually stays in a somewhat coherentmass in the subsurface for a period oftime after some initial mixing at theentry zone. How much and how quicklythe recharged water mixes with nativegroundwater depends on parameters suchas regional groundwater flow velocityand the dispersivity, transmissivity,and heterogeneities of the aquifer.If water is stored only briefly or theaquifer is not highly transmissive, therecharged water mass will likely maintainits integrity, permitting recovery of mostof the stored water. If the water is storedlonger, its mass may eventually dissipatethroughout the aquifer, but if the aquiferis well-constrained, storage will still beevident through elevated water levels.If the aquifer is very large or highlytransmissive, however, physical storagemay be measurable only briefly if at all.Another Kind of StorageFrom a regulatory perspective, storagecan simply mean credit for recharging acertain quantity of water which providesthe storing entity a right to withdraw waterin the future. The water need not stay inany particular location, although ideallyit should stay within the groundwaterbasin. In some states or regions, a storingentity receives an equal amount of creditsfor withdrawal as was recharged. Inother cases, a “tax” may be levied. TheArizona Water Banking Authority takesa five percent “cut to the aquifer” forrecharge of Central Arizona Project waterin recognition that some amount of wateris lost in the aquifer. However, that fivepercent does not have a scientific basis.Robert Maliva of SchlumbergerWater Services points out that so-26 • May/June 2008 • Southwest Hydrology

called “regulatory storage” can causeproblems. Where groundwater use of anaquifer is being limited because of localhydrogeologic concerns such as waterlevels in wetlands or spring flows duringdry periods, the additional pumpingduring recovery from an ASR systemcould actually make matters worse. Ifthe aquifer is not sufficiently constrainedand recharged, water spreads over a verylarge area and no long-term local rise inaquifer water level or pressure occurs tocompensate for subsequent withdrawals.Getting It BackWhen fresh water is recharged into brackishor saline aquifers, an initial “investment”of unrecoverable water is often necessaryto, in effect, clean out space in the aquifer.Recovery ceases when water qualitydeteriorates. When fresh water is rechargedinto a fresh-water aquifer, recovery of anequivalent mass matters more than gettingthe same molecules back—and storagemay only be of the regulatory kind.Recovery can take place on a regular cycle,such as during the annual dry season, or itmay simply be part of the long-term plan,such as for future development or droughtprotection. Many long-term projects in theSouthwest have no specific recovery plansyet. In an ASR project under development,the City of Phoenix plans to recharge andrecover on an annual cycle, but will onlyrecover slightly more than 50 percentof the 1,900 acre-feet per year that willbe recharged, with the remainder usedto maintain the aquifer for future needs.For the privately-owned Vidler RechargeFacility, recovery will be initiated at anundetermined time in the future dictated byeither sale of some or all of the water creditsor Vidler’s decision to build a developmentitself. Project goals also influenceplacement of the recovery system relativeto the recharge facilities (see sidebar).On Recovery EfficiencyRecovery efficiency is strictly definedas the amount of useable water that isrecovered compared to the volume thatwas recharged, for a single recharge/recovery cycle in a dual-purpose well.This calculation is typically used whereIs Downgradient Recovery Better Than Upgradient Recovery?Mark Cross – Errol L. Montgomery & Associates Inc.Placement of recovery wells relative to recharge facilities varies widely in practice due to differencesin recharge and recovery objectives, legal and regulatory constraints, hydrogeologic conditions, andother factors. If the intent is to recover the same water that was used for recharge, recovery wellsshould be located at or down-hydraulic-gradient from the recharge site. However, if the objective ofrecharge is simply to increase the amount of water in storage, recovering the same water may notbe important and recovery wells need not be located at or downgradient from the recharge site.The physical benefits of recharge include increased water storage and water-level rise, or at leastreduced water-level decline. A common misconception is that these benefits are greater downgradientfrom a recharge site than upgradient. However, both theory and practice indicate that the benefits ofincreased storage radiate outward in all directions from a recharge site, depending only on aquiferhydraulic properties (transmissivity, storage coefficient). The magnitude of the water-level rise (or reducedwater-level decline) diminishes dramatically with distance from the recharge site. The magnitude ofwater-level rise does not depend on the rate or direction of groundwater movement, only on aquiferhydraulic properties and distance from the recharge site. Thus, if recovering the same water is notimportant, no advantage is gained by locating recovery wells downgradient from the recharge facility.Contact Mark Cross at mcross@elmontgomery.com.fresh water is stored in a brackish-wateraquifer for seasonal use; water is recovereduntil concentrations exceed a drinkingwater standard, such as for chloride ortotal dissolved solids. For fresh-watersystems having a well-defined aquifer, aquantity-based recovery efficiency can beestimated using a mass-balance approachand changes in water level elevations.According to Maliva, too much emphasisis placed on achieving high recoveryefficiency, with the implication that a projectis wasting water otherwise. But if water isbeing stored that would have been lost, thatin itself is a benefit. As an example, thetownship of Clayton, Australia, is storingfresh water in a saline aquifer. The recoveryefficiency of the project is less than 10percent, but the system is providing muchneededfresh water at lower cost than otheroptions and is viewed as a success. Thesystem stores excess lake water during wetperiods that would otherwise not be put tobeneficial use. The water that is recoveredcomprises a critical component of thetown’s water supply during dry periods.Water Is LostNo large-scale water storage system isloss-proof. Just as reservoirs lose someamount of water to evaporation, artificiallyrecharged water is undoubtedly not entirelyrecoverable, although one could argue thatat least it remains in its liquid form and goessomewhere. Loss to fresh-water aquifersgenerally is not monitored or calculated.It may not be a problem now when morerecharge than recovery is occurring, butwhen storing entities start cashing in theircredits, the importance of knowing wherethat water went will likely increase.Hydrogeologists NeededWater Management Consultants is aninternational company providing specializedservices in groundwater, surface water,geochemistry and engineering.The company is expanding rapidly and has aninteresting and challenging portfolio of projectsin the US. Excellent experience and careerdevelopment is offered to motivated individuals,together with competitive salary and benefits.Suitable candidates are sought for the followingvacancies, based in our Tucson, Reno, andDenver Offices:Senior HydrogeologistA minimum of 7 year experience with a MastersDegree in Hydrology or closely relateddiscipline. Skills in numerical groundwater flowmodeling would be a strong advantage.Staff and Project HydrogeologistsGraduate through 4 years experience, with aMasters Degree in Hydrology or closely relateddiscipline. Strong ability in numerical andanalytical hydrogeology and a willingness toparticipate in field programs.For further information or to arrange aninterview please contact Piccola Dowling:Telephone: 520 319-0725Email: pdowling@watermc.com3845 N Business Center Drive, Suite 107Tucson, Arizona, 85705.May/June 2008 • Southwest Hydrology • 27

Water Spreading in the DesertMario R. Lluria – HydroSystems Inc.In the late 1980s, the portion ofthe Central Arizona Project (CAP)aqueduct that conveys water fromthe Colorado River to Phoenix wascompleted. At the time, the Salt RiverValley lacked sufficient surface storagecapacity for Arizona’s unused portionof CAP water, and storage in the distantreservoirs of the Salt and Verde rivers wasprohibitively expensive. Consequently,the Salt River Project (SRP) and severalmunicipalities agreed to develop a largeunderground water storage facility. A studyfunded by the Arizona Municipal WaterUser Association (AMWUA) identifiedfavorable sites in the Salt and Agua Friarivers for in-channel groundwater recharge,a method successfully used for manyyears in the Los Angeles Basin to storewater in the underlying alluvial aquifer.The First Facility: GRUSPIn 1986, the City of Mesa and SRPinitiated work on a large water-spreadingrecharge facility in the East Salt RiverValley. Based on the AMWUA study,SRP evaluated a 7-mile-long reachof the lower Salt River immediatelydownstream of Granite Reef Dam, andfound favorable hydrogeologic conditionswith no environmental constraints.Four potential sites were selected, allnear the SRP water delivery system andits large-capacity wells, providing thenecessary supporting infrastructure. In1987, Phoenix-area municipalities joinedwith SRP to select a site, acquire the land,and design, permit, construct, and operatethe regional Granite Reef UndergroundStorage Project (GRUSP). More than 90percent of the site would be within the SaltRiver Pima-Maricopa Indian Reservation.Negotiations with the tribal governmentconcluded in 1992 with the leasing of a350-acre parcel for a period of twentyyears. Every five years the land is reappraisedand the rent adjusted accordingto current value. The main determinant isthe value of the land’s sand and gravel,which is in high demand. Thus, a steady,substantial rent increase has affectedthe unit cost of recharge at GRUSP.The permit process for GRUSPcommenced in 1987 and was completedin 1992. Two federal permits wererequired under the Clean Water Act,one each from the U.S. EnvironmentalProtection Agency and the Army Corpsof Engineers. State permits were issuedby the Arizona Department of WaterResources (for underground storage) andthe Arizona Department of EnvironmentalQuality (for aquifer protection).Construction and OperationIn 1994, four recharge basins with a totalarea of 174 acres were completed. Twomore added in 1999 increased the areato 225 acres. Originally, CAP water andwater from the Salt and Verde rivers wereused for recharge; in 2007 reclaimedwater was added. The waters are mixedbefore entering the recharge basins.One of the most important factors inGRUSP’s successful operation is the site’sfavorable hydrogeologic characteristics.On the periphery of the large Salt RiverValley tectonic basin, the site’s coarsegrainedunconsolidated sands and gravelshave high permeability and water storagecapacity, producing recharge rates of 2 to7 feet per day. The storage capacity of thearea of hydrologic impact exceeds onemillion acre-feet. Over 920,000 acre-feetof water have been stored in GRUSP,both short-term and long-term, over its13 years of operation (Lluria, 1998).View of the Granite Reef Underground Storage facility in 1995, showingcanals transporting CAP water to the facility in the Salt River Valley.28 • May/June 2008 • Southwest Hydrology

The cost of construction of the GRUSPfacility was $1.2 million, with a totalproject cost at the start in May 1994 of$2.2 million. Ownership of GRUSP isheld by SRP and the cities of Chandler,Gilbert, Mesa, Phoenix, Scottsdale, andTempe. The recharge capacity for eachcity is based on entitlement, with rechargerights based on percent ownership. Otherentities have also used GRUSP; of these,the Arizona Water Banking Authority hasaccumulated the most water storage credits.Challenges and SolutionsGRUSP has faced some challenges.All delivery and recharge facilities areconstructed of river bed material and aresubject to damage during stormwaterreleases from Granite Reef Dam. Damagecaused by such releases are of primaryconcern because of reconstruction costs,but only three flood events, in the wintersof 1995, 2005, and 2008, have occurred sofar. Successful mitigation measures haveincluded breaching some of the structuresto route flows and minimize erosion.In 1994, a sanitary landfill was completedone mile north of the GRUSP site.Groundwater mounding under thelandfill is controlled by regulating inflow,rotating the operating recharge basins,and increasing the hydraulic gradientaway from the landfill by pumping.Evapotranspiration losses are minimizedby controlling the vegetation in thedelivery and recharge units of the facility.Benefits AccruingThe principal benefit of GRUSP has beenreplenishment of the aquifer beneath theEast Salt River Valley. The equivalentof 40 percent of the total water storagecapacity of SRP’s reservoir system forthe Salt and Verde rivers has been addedto the aquifer for future recovery. As thefirst ASR project in the Phoenix area,GRUSP was able to store a large volumeof CAP water which otherwise wouldhave gone to California. The rechargeoperation has also improved the qualityof groundwater near the site by reducingarsenic and nitrate concentrations. Finally,GRUSP has improved SRP’s operationalflexibility and the water managementpractices of several municipalities.On the West Side: NAUSPTo provide aquifer storage services to thewestern Phoenix metropolitan area, SRPconstructed the New River Agua FriaGRUSP was able tostore a large volumeof CAP water whichotherwise would havegone to California.Underground Storage Project (NAUSP)with four partnering municipalities.Agricultural land was purchased on theeastern bank of the Agua Fria River in itsancestral fluvial system, where favorablehydrogeologic characteristics existedfor direct surface groundwater recharge(Paski and Lluria, 2005). The site is on theperiphery of a large cone of depression,where considerable land subsidencehas occurred and aquifer replenishmentis urgently needed (Lluria, 1995).NAUSP was completed in March 2007 andstored 21,000 acre-feet of water last year,achieving recharge rates of 1 to 3 feet perday. The facility consists of six off-channelbasins with a 126-acre infiltration area. Aseventh in-channel basin of 65 acres will beadded in 2008. The facility receives waterfrom CAP and the Salt and Verde rivers,plus a small volume of reclaimed water. Thewaters are blended before recharging. TheNAUSP facility is permitted for a maximumvolume of 75,000 acre-feet per year, 40percent of the permit capacity of GRUSP.During facility development, a fewdifficulties had to be resolved. Theoriginal site in the Agua Fria Riverchannel was abandoned because ofits proximity to future gravel miningoperations. Topsoil from the agriculturalfields had to be removed for constructionof the off-channel basins to ensureadequate infiltration rates and eliminatepotential agriculture contaminants. Thecost of land was high because of itsproximity to the recently completedCity of Glendale sports center.NAUSP will provide a much-neededunderground storage facility for the area,particularly for the temporary storageof reclaimed water. It will capture flowsin the tail end of the SRP system thatmight otherwise go unused. The rechargeactivity will improve groundwaterquality near the site by diluting the highnitrate concentrations caused by decadesof agriculture. Having two rechargefacilities, one located near the head ofthe water delivery system, the othernear its terminus, considerably increasesthe operational flexibility of SRP’swater resources management system.Contact Mario Lluria at mario@hydrosystems-inc.com.ReferencesLluria, M.R., 1995. Site selection for aquifer storageprojects in the Lower Agua Fria Basin, in Proc.7th Biennial Symp. on Artificial GroundwaterRecharge, Santiago, Chile.Lluria, M.R., 1998. Successful operation of a largeaquifer storage facility for a desert community,in Artificial Recharge of Groundwater, ed. J.H.Peters, Rotterdam, A.A. Balkema.Paski, M.P., and M.R. Lluria, 2005. Hydrogeologicand geologic considerations for site selection ofa large water spreading facility in the West SaltRiver Valley., in Proc. 12th Biennial Symp. onGroundwater Recharge, Tucson, AZ.Total Water Management19,000 professionals serving your needs in: Solutions Without Boundariesch2mhill.com Tel: 505.884.1682 x205 Tel: 480.966.8577 x6239WB052007020MKT© 2007 CH2M HILLMay/June 2008 • Southwest Hydrology • 29

ASR in Roseville:Navigating Water Quality IssuesChristian E. Petersen – MWH Americas Inc. and Kenneth Glotzbach – City of RosevilleThe City of Roseville, in theCentral Valley of Californianear Sacramento, is studyingthe feasibility of aquifer storage andrecovery (ASR) to maintain water supplyreliability during dry periods. An ASRpilot and demonstration project hasbeen underway since 2004 to improveunderstanding of the hydrogeologicfactors affecting well flow and waterquality, identify and address regulatoryconcerns, and evaluate operationalconsiderations associated with augmentingRoseville’s water supply with ASR.Water SupplyThe city’s current annual surface watersupply of 66,000 acre-feet is AmericanRiver water diverted from Folsom Lake.The city maintains a contract entitlementwith the U.S. Bureau of Reclamationfor 32,000 acre-feet per year for CentralValley Project supplies and contracts withlocal agencies for the remaining 34,000acre-feet per year, some of which isavailable only in normal and wet years.Roseville may also purchase Section 215water, released by Reclamation fromFolsom Lake in excess of the entitlementsLonger-term testingwas needed tounderstand the fateand transport of DBPsin the subsurface.and rights of downstream users when it isavailable, but has not done so yet. FolsomLake water treated to potable standards atRoseville’s water treatment plant is beingused for the ASR testing and will alsobe the supply for the long-term project.A county policy prevents Rosevillefrom relying on groundwater as asource of supply. Roseville intends tooperate its ASR program as a seasonalstorage program, but would alsolike to retain some water in longertermstorage as protection againstdroughts. ASR is allowed by the countybecause it does not result in a net takefrom the basin: the volume of waterextracted will not exceed the volumeinjected and stored in the aquifer.Testing ASR FeasibilityASR testing at Roseville is beingcompleted in two phases. First, a shorttermpilot test was conducted in 2004using the Diamond Creek well, whichwas installed as a dual-purpose injectionrecoverywell. It is screened from 310to 450 feet below ground surface in aconfined zone of the target aquifer, theMehrten Formation (see figure, top right),a coarse-grained sand, gravel, and cobbleof volcanic origin deposited in a fluvialenvironment. Three existing wells wereused to monitor water level and waterquality in the aquifer during the test.Results from the short-term test indicatedthat ASR is feasible in Roseville, butthat longer-term testing was neededto understand the fate and transportof disinfection byproducts (DBPs) inthe subsurface. Therefore, Phase IIdemonstration testing began in November2005 and was to be completed in May2008. Water quality and water levelsare again being monitored in the fourwells. No problems have yet beenencountered regarding well pluggingassociated with solids accumulation orgeochemical precipitation in the well.Enter the Regulatory EnvironmentAlthough drinking-quality water mightappear to be ideal to store underground,California’s water quality regulators sawit differently. The State Water ResourcesControl Board oversees nine regional30 • May/June 2008 • Southwest Hydrology

water quality control boards (RWQCBs)that develop and enforce water qualityobjectives and implement plans to protectthe state’s waters, recognizing differencesin climate, topography, geology, andhydrology. This means that regulation ofASR has evolved inconsistently amongregional boards throughout the state.The Roseville ASR project lies withinthe purview of the Central ValleyRWQCB. CVRWQCB determined thatthe ASR test project would be regulatedunder a conditional waiver of wastedischarge requirements, even thoughthe project is using drinking water thatmeets all standards. The problem is thedrinking water contains DBPs at levelsgreater than the groundwater basinwater quality objectives. The waiverallows the test project to proceed aslong as DBP concentrations remainbelow EPA’s maximum contaminantlevels for a short-term, controlledproject. The waiver requires:• estimation of the aquifer volume to beimpacted by injected drinking water;• establishment of a monitoringprogram to confirm that storeddrinking water is contained within thatportion of the aquifer defined above;• reporting of project status and testingresults to CVRWQCB every 60 days;• submission and implementation ofcontingency plans to clean up or abateunintended impacts on groundwaterquality, should the demonstration projectresult in a violation of water qualityobjectives beyond the predicted injectionfront or after the stored water has beenextracted; and• the extraction phase of testing tocontinue until DBP concentrations arebelow basin objectives (1.1 microgramsper liter [µg/l] for chloroform).Results to DateResults (see MWH, 2008) indicate thatASR in Roseville has two significantwater resource benefits including:• a rise in regional groundwater levelsof approximately five feet during thefive-month injection period, andcontinued on next pageTotal Haloacetic Acids (ug/L) Chloroform (ug/L)807060504030201006050403020100West-SouthwestStatic Water LevelFair Oaks Formation10Mehrten FormationView Toward NorthDiamond Creek Well100'175'250'350'Pre-MehrtenSediments8 6Miles4Tuff-BrecciaGranitic Rocks2East-NortheastRegional geologic cross-section through Diamond Creek well site. Modified from DWR, 1974.Base InjectionStorage Extraction Post-TestDCMW-1DCMW-2DCMW-3DCWWTPMCL11/112/11/11/313/34/25/36/27/38/29/210/211/212/21/22/13/44/35/46/37/48/39/310/311/312/31/32/23/44/35/42005 2006 20072008400300200100SeaLevelChanges in concentrations of chloroform (top) and total haloacetic acids (bottom) duringdemonstration testing in the Diamond Creek well (DCW), three monitor wells (DCMW-1, 91 feetcrossgradient of injection; DCMW-2, 193 feet upgradient; and DCMW-3, 402 feet downgradient),and the water treatment plant (WTP), compared to EPA’s maximum contaminant level (MCL).Units are micrograms per liter (μg/l). The chloroform plot is nearly identical to that of totaltrihalomethanes (THM), as chloroform accounts for 90 to 95 percent of THM.-100-200-300-400-500Elevation in FeetMay/June 2008 • Southwest Hydrology • 31

continued from previous page• a reduction in total dissolved solids(TDS) concentrations in the aquifer froman average of 457 milligrams per liter(mg/l) to 59 mg/l at the beginning of thestorage phase, measured at the DiamondCreek Well. The TDS of the water beinginjected ranged between 47 and 62 mg/l.The charts on the previous page showthe changes in DBP concentrationsduring each period of the demonstrationtest. By comparing DBP to conservativeconstituents such as chloride and fluoride,it appears that haloacetic acids werenaturally attenuated in the aquifer duringthe storage phase of testing: they werenot detected after five months of storage.Trihalomethane (THM) concentrations(as represented by chloroform) werereduced during the storage period, but notcompletely eliminated. The mechanism ofTHM reduction is not fully understood,but appears to be caused by dilution,again based on correlation with chlorideconcentrations over the same time period.Long-Term PlansRoseville expects to complete thedemonstrate test by May 2008 and tohave extracted 300 percent of the injectedvolume in an effort to remove DBPs belowbasin objectives (chiefly chloroform below1.1 µg/l). Clearly 100 percent injectionfollowed by 300 percent extraction is notsustainable for long-term operation, butwas necessary to comply with the waiverfor the testing phase of implementation.Roseville and CVRWQCB now have abetter understanding of the water qualityimplications of a long-term ASR operation.What’s next? Roseville has begundiscussions with CVRWQCB managementand staff regarding long-term operationof ASR in Roseville and expansion ofthe program to eventually include upto 12 operating ASR wells over thenext three to five years. In strikinga balance between the water supplybenefit of ASR and the need to protectgroundwater quality, it is anticipated thata long-term operational permit will:• allow a designated portion of theaquifer to be impacted above basinobjectives during the operationallife of the ASR program;• establish institutional controls to preventother beneficial users from accessing theportion of aquifer designated for ASR;• allow a point of compliance within theaquifer downgradient of the project;• require a reasonable monitoringprogram, agreed upon by Roseville andCVRWQCB; and• likely require that water qualityobjectives be restored to either pre-projectconditions or reasonably achievableconditions at the end of the project.Contact Chris Petersen at Chris.E.Petersen@us.mwhglobal.com or Kenneth Glotzbach atkglotzbach@roseville.ca.us.ReferencesCalifornia Department of Water Resources(DWR), 1974, reprinted 1980. Evaluation ofGroundwater Resources: Sacramento County.Sacramento Bulletin 118-3.MWH, 2008. Diamond Creek Well Phase IIDemonstration ASR Project: Monitoring Report13, Jan. 22.ASR Primer, continued from page 17removed by traditional wastewatertreatment processes. Much research isbeing conducted on the potential healthrisks associated with introducing reclaimedwater to potable aquifers. Lastly, pathogenremoval by chlorination can causeformation of disinfection byproducts,such as trihalomethanes, that can persistin some ASR systems (NRC, 2008).Getting It BackRecovery is a critical component ofany ASR system because the objectiveis to recover the recharged water, or anearly equivalent amount, in the future.However, full capture and recoveryis not always feasible due to aquifercharacteristics and the practical placementof wells. As a result, the potential existsfor losing a portion of recharged water.However, water recovery issues canalso be political or legal in origin, aswhen a governing entity intervenesand imposes limitations on the rate orvolume of water that can be recovered.32 • May/June 2008 • Southwest HydrologyThe management, monitoring, andaccounting of recharged water areinherently obscure as groundwater is notvisible. Therefore, computer models,monitoring wells, and sophisticatedaccounting systems are employed toaccomplish these tasks. Even withthese tools it can be challenging toadequately demonstrate control andcapture of recharged water. Manywestern states utilize some form of priorappropriation to allocate scarce waterresources. Some states such as Coloradoadminister groundwater and surface waterconjunctively, and others administerthese resources discretely. The protectionof senior water rights can representa significant barrier to ASR projects,particularly with respect to accountingand recovery. It must be demonstrated thatASR operations will not cause an out-ofprioritydiversion of stream flows or nativegroundwater that is not otherwise replaced.Source water availability can be thelimiting factor for some entities, evenwhen a suitable aquifer and recoverysystem are available. However, thesesituations can engender creative solutionssuch as “borrowing” source water froma surface water provider in exchangefor delivering groundwater to the sameprovider during periods of drought.ASR is expanding in scope and complexityas more projects are initiated, long-termdata become available, monitoring andanalytical technologies advance, and thedemand for water increases with respectto supply. Not every situation or set ofconditions is favorable for implementingASR, and ASR will not displace theneed for surface storage. However, itis a viable alternative and a beneficialwater management technique where andwhen the necessary ingredients exist.Contact Cortney Brand at CBrand@RWBeck.com.ReferencesNational Research Council (NRC), 2008. Prospectsfor managed underground storage of recoverablewater, National Academies Press, www.nap.edu.Pyne, R.D.G., 1995. Groundater Recharge and Wells:A Guide to Aquifer Storage Recovery, CRCPress Inc.

The Arizona Hydrological Society extends our sincere thanks to the 2007 Symposium PlanningCommittee, Southwest Hydrology magazine, and SAHRA for their contributions to the 2007Annual Symposium. Without their efforts, the symposium would not have been such a success.We invite everyone to the 2008 Symposium:Changing Waterscapes andWater Ethics for the 21st CenturyMeeting Highlights• Technical sessions addressing critical water issues• Professional sessions dealing with regulatory and educational concerns• Technical tours• Social events• 7-day geological raft excursion through Grand Canyon12 Field Trips, including:• Grand Canyon• San Francisco Volcanic Field• Fossil Creek• Sunset Crater/WupatkiNational Monument• Jerome Mining District/Sedona• Meteor Crater• Flagstaff Area Water Supply6 Workshops• Intro to ArcGIS• Intro to Arc Hydro• Writing for the Reader• Water Education/Project WET• Students Entering the Profession• Important Areas of Waterand Environmental LawWho Will AttendThis convention will appeal to professionals in technical, educational,regulatory, and legal disciplines. Professionals attending from the U.S.,Canada, Mexico, and Europe will provide an international perspectiveto the proceedings.High CountryConference Center &The Radisson Hotel,Flagstaff, AZSeptember 20-24, 20083rd International Professional GeologicConference: Global Geoscience Practice,Standards, Ethics and AccountabilityHosted by American Institute of Professional Geologistsand Arizona Hydrological SocietyGo to www.aipg.org/2008/AIPG-AHS-3IPGC.htm informationabout sponsorship, exhibit booth, and advertising opportunities—act soon!

R & DDire Predictions for ColoradoRiver ReservoirsThere is a 50 percent chance live storage(water that can be evacuated by gravity)in lakes Mead and Powell will be gone by2021 if climate changes occur as expectedand no changes in water managementstrategies are made, according to TimBarnett and David Pierce at ScrippsInstitution of Oceanography at theUniversity of California, San Diego.Furthermore, the reservoirs have a 50percent chance of dropping too low toallow hydroelectric power generationby 2017. The researchers performedtheir analysis using a simple waterbudget model and reported their findingsin a paper accepted for publicationin Water Resources Research.The release of the report generatedheadlines across the country, and somecontroversy. Among the scientificcommunity, disagreement with the study’s34 • May/June 2008 • Southwest Hydrologyapproach appears to center on whetherthe climate prediction models used bythe Scripps researchers are sensitiveenough at the regional scale to makeaccurate predictions. The U.S. Bureauof Reclamation recently completed anextensive analysis of Colorado Riverbasin flows, but its researchers based theiranalyses on tree-ring data to considerthe range of historic flows over the last1,200 years, rather than climate models,which they deemed not scalable to localeffects. Disagreement—often colorful—also came from water managers whosaid the findings are overly alarming:managers would take steps to preventthe dire predictions from coming true.According to a Scripps news release,the researchers were conservative. Theybased their findings on the premise thatclimate change effects started in 2007,even though most scientists considerhuman-caused changes in climate to havestarted decades earlier. They based theirColorado River flow on the 100-yearaverage, although actually it has fallen inrecent decades and the 500-year averageis even lower. Even if water agenciesfollow their current drought contingencyplans, they found, it might not be enoughto counter natural forces, especially ifthe region enters a period of sustaineddrought or human-induced climatechanges occur as currently predicted.Check back in 15 years…Visit scrippsnews.ucsd.edu/Releases/?releaseID=876or www.agu.org (members only).Mussel UpdateYou wouldn’t think mussels that moveat a snail’s pace would be able to crossthe country like birds and reproducelike rabbits, but it appears that is what’shappening. It was only in January 2007that the first quagga mussels west of theMississippi River were confirmed in LakeMead (see Southwest Hydrology, Jul/Aug2007 and Nov/Dec 2007). But in the lastseveral months, news of the invasionhas become worse: the prolific quaggasthat clog pipelines and machinery andupset ecosystems appear to be thrivingin the Colorado River Basin, and theircousins, the zebra mussels (both genusDreissena), has also invaded the West.In February, the Las Vegas Review Journalreported that the quaggas in Lake Havasuand other reservoirs are reproducingthree times faster than those in the GreatLakes area, at a rate of six times per yearrather than two, according to Bureauof Reclamation quagga coordinatorLeonard Willett. He estimated the costto manage the mussel population andmaintain operations in Hoover Damalone could reach $1 million per year.Without control, quaggas can clog coolingpipes, causing turbines to overheat, saidthe newspaper. Control options underconsideration are a soil bacterium thattargets quaggas (still in development),filters, chemicals such as chlorine, andultraviolet light. However, most of

those approaches require that dischargepermits be obtained, noted the article.The warmer temperatures of ColoradoRiver reservoirs, combined withplentiful food, calcium, and dissolvedoxygen appear to be helping the musselsthrive, Willett told the Review Journal.He also noted that quaggas seem toprefer flat, stainless-steel structuresin relatively slow-moving water tocolonize; they dislike copper and brass.Meanwhile, in January, the CaliforniaDepartment of Fish and Game confirmedthat zebra mussels had been identifiedin the San Justo Reservoir south ofthe San Francisco Bay area. Resourcemanagers have been dreading the arrivalof zebra mussels in the West; Reclamationscientists estimated those that werefound were around one to three yearsold, reported the Hollister Freelance.According to the 100th Meridian Initiative,the Lake Mead quagga population is inan explosive growth stage now. Of note,this is the first North American instance ofquaggas invading a large water body thatwas not already invaded by zebra mussels.Quaggas may grow slightly larger andlive in deeper waters than zebra mussels.Visit www.lvrj.com, www.hollisterfreelance.com, and100thmeridian.org.Ag, Urban Activities ImpactShallow Groundwater QualityA new U.S. Geological Survey reportlinks the quality of shallow groundwaterin alluvial basins of California, Arizona,Nevada, Utah, and New Mexico topresent and past land use and chemicalsused in agricultural and urban areas.Chemicals most heavily applied includefertilizers, herbicides, and insecticides.Volatile organic compounds (VOCs) areused in large volumes and associatedwith products such as plastics, adhesives,paints, gasoline, fumigants, refrigerants,and dry-cleaning fluids. Although shallowcontinued on next pagecontinued on next page • Water Resource Policy & Economics• Water Resource Engineering• Automated Vadose Zone MonitoringErrol L. Montgomery & AssociatesWater Resource Consultantswww.elmontgomery.comToll Free 8 8 6 . 7 4 4 . 1 6 3 3May/June 2008 • Southwest Hydrology • 35

R & D (continued)groundwater is not typically used as adrinking-water supply in these basins,in some areas it could be hydrologicallylinked to deeper basin-fill aquifersystems that are used for water supply.The study showed that nitrateconcentrations were highest beneathagricultural lands, and exceeded the U.S.Environmental Protection Agency drinkingwater standard of 10 milligrams per literin 74 of 272 wells (27 percent) in thoseareas. Nitrate concentrations generallywere lower in urban areas, exceedingthe standard in 13 of 179 urban wells(7 percent). Shallow groundwater samples(median well depth of 35 feet) werecollected mostly from monitoring wells,but some domestic wells were sampled.Through geostatistical modelingtechniques, the study estimated theprobability of exceeding the nitratestandard in shallow groundwaterunderlying agricultural areas throughoutthe region. The information can help waterquality managers anticipate conditions inunmonitored areas and implement nitrogenreduction strategies in priority areas.The study also found that concentrationsof organic compounds rarely exceededdrinking-water standards, and generallywere detected at concentrations less than1 microgram per liter. The most frequentlydetected pesticides in shallow groundwaterbeneath agricultural areas were simazine(28 percent of the wells), atrazine (17percent), and diuron (13 percent). In urbanareas, atrazine (24 percent of the wells),prometon (25 percent), and simazine (17percent) were most commonly detected.VOCs were typically detectedunderlying urban areas. Those mostfrequently detected were chloroform(in 29 percent of the wells) and PCE(10 percent); they were often foundin well-oxygenated groundwater.Because the quality of shallowgroundwater can change relativelyquickly, it can be an indicator ofland-use stresses that may eventuallyaffect deeper aquifer systems.The 70-page report, “Effects of Agriculture andUrbanization on Quality of Shallow Groundwater inthe Arid to Semiarid Western United States, 1993–2004,” is available at pubs.usgs.gov/sir/2007/5179.Also visit water.usgs.gov/nawqa/studies/praq/swpa.Humans Affect WesternWater FlowThe Rocky Mountains have warmedby 2ºF in the last 50 years. Snowpackin the Sierras fell 20 percent and thetemperatures there have increased by 1.7ºF.Why? Humans, according to scientistsfrom Lawrence Livermore NationalLaboratory’s (LLNL) Program for ClimateModel Diagnosis and Intercomparison,and Scripps Institution of Oceanography.Their research appeared in the Jan. 31online edition of Science Express.Fast SafeSecurewww.envirotechonline.comFind Productsby byCategory BrandorDetailed Product Information36 • May/June 2008 • Southwest Hydrology

“We looked at whether there is a humancausedclimate change where we live, andin aspects of our climate that we reallycare about,” said Benjamin Santer ofLLNL and co-author of the paper. “Nomatter what we did, we couldn’t shakethis robust conclusion that human-causedwarming is affecting water resourceshere in the Western United States.”By looking at air temperatures, river flow,and snowpack over the last 50 years, thescientists determined that a human-inducedincrease in greenhouse gases has seriouslyaffected the water supply in the West. Theresearchers scaled global climate modelsdown to the regional scale and comparedthe results to observations over the last 50years. The results were consistent, givingconfidence that the same models couldbe used to predict the future effects ofthe global scale increase in greenhousegases on the western United States.The projected consequences are bleak.By 2040, most of the snowpack in theSierras and Colorado Rockies would meltby April 1 each year because of rising airtemperatures. Earlier snowmelt would leadto a shift in river flows, potentially leadingto flooding in California’s Central Valley.Santer said the increase in predictedriver flow should be a wake-up callto officials that the water supplyinfrastructure needs to be updated now,as opposed to waiting until the situationis urgent. As for the warming, existinggreenhouse gases in the atmospherewill cause the Earth to continue towarm for the next 80 to 100 years.Visit www.llnl.gov and www.sciencemag.org/sciencexpress/recent.dtl.Coachella Valley is SinkingA new study by the U.S. GeologicalSurvey and Coachella Valley WaterDistrict (CVWD) confirms that landsubsidence is occurring in areas ofsubstantial groundwater use throughoutCoachella Valley, located in the Palmcontinued on next page© 2007, GACRoscoe Moss CompanyNo single screen type is appropriate for all wells. Roscoe Moss Company is the only manufacturerin the world producing shutter screen, continuous slot screen, bridge slot screen, and slotted pipe.This ensures that Roscoe Moss Company’s customers receive unbiased technical assistancedirected toward solving their specific problems.4360 Worth Street, Los Angeles, CA 90063 • Phone (323) 263-4111 • Fax (323) 263-4497www.roscoemoss.com • info@roscoemoss.com© 2006 Roscoe Moss Company. All Rights Reserved.We make water workworldwide.How do you manageone of Earth’s mostprecious resources?Ask Golder.We focus on sustainable water resource solutions.The world’s most precious resource is becoming more precious by the minute. That’s why responsiblemanagement is critical to ensuring water for industry and agriculture, for household needs…and for thefuture. Golder has been providing cost-effective solutions to satisfied clients for over 45 years, findingbetter ways to discover, produce, transport, manage and treat water.A World of Capabilities Delivered Locally.Local offices: Tucson (520) 888-8818 / Phoenix (480) 966-0153Albuquerque (505) 821-3043 / Silver City (505) 388-0118solutions@golder.comwww.golder.com/water445_USA_JBush_v3PRESS.indd 1May/June 2008 • Southwest 11/16/07 Hydrology 1:39:04 • PM 37

Well Problem IdentificationInvestigative Water Consulting and Diagnostic Laboratory• Biological and Mineral Fouling• Production Loss• Taste & Odor Issues• Water Quality• Corrosion• ASR SystemsWater Systems Engineering, Inc.phone: 785.242.6166 and 785.242.5853URL: http://www.h2osystems.comR & D (continued)Springs area of Riverside County,California. The two agencies initiated thestudy in 1996 when it was first believedsubsidence was occurring there. USGSscientists used Global Positioning System(GPS) surveying and a satellite mappingprocess known as interferometric syntheticaperture radar (InSAR) to document dropsin elevation between 1996 and 2005.At all of the GPS benchmarks, somesubsidence occurred between 1996 and2005. At three benchmarks, the drop wasless than an inch, while at three otherssubsidence was about one foot. At onebenchmark, a one-foot drop in landsurfaceelevation happened from 2000to 2005.“The subsidence rates in many areas havemore than doubled since 2000,” saidMichelle Sneed, USGS scientist and leadauthor of the study. “All the subsidingareas are near sites where groundwaterlevels declined between 1996 and 2005,and some water levels in 2005 were at thelowest levels in their recorded histories.”The research, which has cost about$790,000 since 1995, has been fundedprimarily by USGS and CVWD, with theCity of Palm Desert contributing $17,000.Since the 1920s, groundwater has been amajor source of agricultural, municipal,and domestic supply in the CoachellaValley, resulting in significant groundwaterpumping that has contributed to waterleveldeclines of as much as 100 feet. Theheavy groundwater use, in turn, has ledto subsidence.The Conservation Currentis now exclusively online.Regional water conservation news provided quarterlyby the New Mexico Water Conservation AllianceDon’t miss an issue – sign up online. It’s quick and easy...Just visit http://wrri.nmsu.edu/wrdis/nmwca/alliance.htmland click “conservation current”In 2001, CVWD adopted a comprehensiveWater Management Plan (WMP) toaddress the groundwater overdraftproblem. The plan takes a three-tieredapproach to groundwater management:increasing the imported water supply,promoting and assisting conservationefforts, and providing existing groundwaterusers an alternative source of water.CVWD planned and prioritized nearly50 programs and projects for the38 • May/June 2008 • Southwest Hydrology

WMP. Current efforts aimed at keepinggroundwater levels stable includeconstruction of the $70 million Mid-Valley Pipeline to enable as manyas 50 golf courses to use a blend ofrecycled water and Colorado Riverwater in lieu of groundwater, and a $40million groundwater recharge facility.The 41-page report, “Detection and Measurement ofLand Subsidence Using Global Positioning SystemSurveying and Interferometric Synthetic ApertureRadar, Coachella Valley, California, 1996-2005,” isavailable at pubs.usgs.gov/sir/2007/5251/pdf/sir_2007-5251.pdf.increase in extreme precipitationfrequency, at 61 percent. “Extreme”precipitation was defined relative to thelocal climate at each weather station asany storm with a 24-hour precipitationtotal equal or larger than the least of the59 largest one-day precipitation totalsover the 59-year period of analysis.In the Southwest, where total annualprecipitation is projected to decline,extreme downpours may punctuate longerperiods of relative dryness, increasingthe risk of drought. The increase since1948 in frequency of storms withextreme precipitation ranges from 26to 32 percent for Arizona, California,continued on next pageGlobal Warming Linked toExtreme PrecipitationA recent report published by EnvironmentAmerica found that global warmingis likely to cause an increase in theintensity of precipitation eventsregardless of whether the total annualrainfall increases or decreases.Researchers evaluated trends in thefrequency of storms with extreme levels ofrainfall or snowfall across the contiguousUnited States over the last 60 years. Theyanalyzed daily precipitation records from1948 through 2006 at more than 3,000weather stations, and examined patterns inthe timing of heavy precipitation relativeto the local climate at each. They foundthat storms with extreme amounts of rainor snowfall are happening more often.According to the report, global warmingincreases the intensity of precipitationin two key ways. First, by increasingthe temperature of the land and theoceans, global warming causes water toevaporate faster. Second, by increasingair temperature, global warming enablesthe atmosphere to hold more water vapor.These factors combine to make cloudsricher with moisture, making heavydownpours or snowstorms more likely.The researchers found that storms withextreme precipitation have increasedin frequency by 24 percent across thecontinental United States since 1948.New England experienced the largestMay/June 2008 • Southwest Hydrology • 39

R & D (continued)Colorado, Nevada, Texas, and Utah,up to 44 percent for New Mexico.The researchers note that their findingsare consistent with previous studiesof extreme precipitation patterns. In1999, studies at the Illinois State WaterSurvey and the National Climatic DataCenter (NCDC) found that stormswith extreme precipitation becamemore frequent by about 3 percentper decade from 1931 to 1996. In2004, scientists at NCDC concludedthat most of the observed increasein storms with heavy and very heavyprecipitation levels since the early1900s had occurred in the last threedecades. In other words, the change isrelatively recent. Furthermore, NCDCfound that extremely heavy stormsare increasing in frequency morerapidly than very heavy storms—whichin turn are increasing in frequencymore rapidly than heavy storms.Environment America is a federation of state-based,citizen-funded environmental advocacy organizationswith staff in 23 states and Washington, D.C. The 48-page report is available at environmentamerica.org.Sandia Developing IntegratedEnergy-Water ModelResearchers at Sandia NationalLaboratories are developing an interactivecomputer model that integrates waterand energy demands for planning andmanagement purposes. The objectiveof the model is to “allow energy andwater producers, resource managers,regulators, and decision makers tolook at the different tradeoffs of wateruse and energy production caused byuncertainties in population, energydemand, climate, and the economy,” saidVince Tidwell, principal investigator.Concurrent with the energy-watermodeling, the research team will puttogether a set of optimization toolsthat could be used to assist in thesiting of power plants, balancing theenergy portfolio (including fossil,nuclear, and renewable fuels) to keeppace with growing power demands,and in making decisions about whento build the next power plant. Cost,availability of water and fuels, access totransmission lines, and greenhouse gasemissions all need to be considered.The research is in its second year ofthree-year funding. The team is nowcompiling data to go into the program.The model will allow users to tailortheir investigations to meet specificneeds. For example, they can get resultson energy and water scenarios at thenational, state, or local levels and willbe able to look at specific watersheds.This would be particularly helpful indetermining water-energy trends instates like New Mexico where most ofthe power is generated at in-state plantsbut used by people outside the state.“Energy data is provided by DOE,and water information is coming fromdifferent agencies,” says Peter Kobos,who is also doing energy modeling atSandia. “The challenge will be to haveenough data to tell a story. We thinkwe do. If not, we’ll identify gaps andaddress them as the project progresses.”Visit www.sandia.gov.Business Directory326 South Wilmot RoadTucson, AZ 85711Tel.: 520.326.1898info@HaleyAldrich.comHaleyAldrich.com21 offices nationwide• EnvironmentalRemediation Solutions• Water ResourceInvestigations• Environmental, Health,Safety Compliance• Environmental &Regulatory Strategiesjohn j ward, rggroundwater consultant- water supply - water rights- peer review - litigation support- expert witness - due diligenceTucson AZphone: (520) 296-8627cell: (520) 490-2435email: ward_groundwater@cox.netweb: www.wardgroundwater.com40 • May/June 2008 • Southwest Hydrology

In PrintDamming Grand Canyon: The1923 USGS Colorado RiverExpeditionby Diane E. Boyer and Robert H. Webb,Utah State University Press, 2007, $35Reviewed by Betsy Woodhouse – SouthwestHydrology, University of ArizonaIn 1922, the Colorado River Compactallocated the river’s water among theseven basin states. However, no meansto control that water existed. The U.S.Geological Survey and the much youngerU.S. Reclamation Service were strugglingto figure out their respective roles, andboth wanted a say in control of theColorado. The notes and maps of JohnWesley Powell’s earlier Grand Canyonexplorations were not reliable enough fortheir engineering needs: a detailed mapwas needed.For nearly three months in the summer andfall of 1923, 12 men in four aged, woodenboats traveled through and mapped 29potential dam sites in Grand Canyon.Damming Grand Canyon: The 1923 USGSColorado River Expedition sets the stagefor this wild adventure and then providesa day-by-day account as recorded in theparticipants’ journals.Prelude to the ExpeditionThe book begins with the history ofdevelopment of the Colorado River,including early attempts to control it. Itdelves into politics as well, discussing theformation and early leadership of USGSand Reclamation and their disagreementsover where dams should be built and howthe decision should be made. Finally, itdescribes how the 1923 expedition wasorganized and the dynamics of the group.Journal EntriesThe expedition included engineers,geologists, topographers, boatmen, andcooks. Eight of the men kept journals;their entries, supplemented with narrative,make up the middle part of the book.The journal entries are daily; oftenseveral men’s accounts of the same dayare included. Personal notes, such aswhat they ate or heard on the radio in theevening, add interest. The entries alsooffer insight about the pre-dam GrandCanyon. They wrote of abundant flyinginsects and the scarcity of sandbarsin Upper Granite Gorge, conditionstypically—and incorrectly—attributedtoday to the presence of dams, accordingto the authors.Virtually no mention was made ofenvironmental or aesthetic impacts shoulda dam be built in the canyon, exceptin one brief entry where the trip leadernoted that a proposed damsite might haveengineering drawbacks, but “at least itwouldn’t inundate Bright Angel Creek andPhantom Ranch.”AftermathThe book ends with a description of thesubsequent careers of the expeditionmembers, the outcome of their work, andthe paths the agencies followed.For readers lacking familiarity with theagencies’ histories and the individualsinvolved, it can take some time to keep itall straight. The book is heavily footnoted,which is variously distracting, helpful, andinteresting. Some footnotes explain thesignificance of a particular entry, describehow the reports conflict, or elaborate ona relationship. Without the footnotes, thejournal entries alone would not convey thesame level of conflict among the group.Damming Grand Canyon also containsabundant photos from the expedition thatprovide interesting insight on the men,their equipment, and how the canyonlooked at that time.This book has appeal for a diverseaudience ranging from those interestedin USGS/Reclamation history to thosefamiliar with the canyon and its geology,river rafters, environmentalists interestedin fate the canyon escaped, and those whodream of big dams.Ground-water occurrence and movement, 2006, and water-level changes in the Detrital,Hualapai, and Sacramento Valley Basins, Mohave County, Arizona, by D.W. Anning, M. Truini,M.E. Flynn, and W.H. Remickhttp://pubs.usgs.gov/sir/2007/5182/Dissolved solids in basin-fill aquifers and streams in the southwestern United States, byD.W. Anning, N.J. Bauch, S.J. Gerner, M.E. Flynn, S.N. Hamlin, S.J. Moore, D.H. Schaefer, S.K.Anderholm, and L.E. Spangler http://pubs.usgs.gov/sir/2006/5315An online interactive map service for displaying ground-water conditions in Arizona, byF.D. Tillman, S.A. Leake, M.E. Flynn, J.T. Cordova, and K.T. Schonauerhttp://pubs.usgs.gov/of/2007/1436Land subsidence and aquifer-system compaction in the Tucson Active Management Area,south-central Arizona, 1987-2005, by R.L. Carruth, D.R. Pool, and C.E. Anderson.http://pubs.usgs.gov/sir/2007/5190Water-level and land-subsidence studies in the Mojave River and Morongo Ground-waterBasins, by C.L. Stamos, K.R. McPherson, M. Sneed, and J.T. Brandthttp://pubs.usgs.gov/sir/2007/5097/Urban-related environmental variables and their relation with patterns in biological communitystructure in the Fountain Creek Basin, Colorado, 2003-2005, by R.E. Zuellig, J.F. Bruce, E.E.Evans, and R.W. Stognerhttp://pubs.usgs.gov/sir/2007/5225/May/June 2008 • Southwest Hydrology • 41

T H E C A L E N D A RMAY 2008May 6- 8May 6- 9May 12-16May 14-16May 15May 18-23May 19-21May 28-31Midwest Geosciences Group. Assessing Ground Water Movement and Contaminant Migration Through Aquitards: From FieldInvestigation to Hydrogeologic Analysis. Naperville, IL. www.midwestgeo.com/fermi2008.htmAssociation of California Water Agencies. ACWA Spring Conference and Exhibition. Monterey, CA. www.acwa.com/events/SC08/Environmental and Water Resources Institute of ASCE. World Environmental and Water Resources Congress: Sustainability from theMountains to the Sea. Honolulu, HI. content.asce.org/conferences/ewri2008/33rd Colorado Foundation for Water Education. Colorado Water Workshop: Mining, Energy, and Water in the West. Gunnison, CO.www.western.edu/water/Arizona Hydrological Society. Surface Water Seminar. Phoenix, AZ. www.azhydrosoc.orgAssociation of State Floodplain Managers. 2008 Conference: A Living River Approach to Floodplain Management. Reno, NV.www.floods.org/Conferences%2C%20Calendar/Reno-Sparks.aspInternational Ground-Water Modeling Center. MODFLOW and More: Ground Water and Public Policy. Golden, CO.www.mines.edu/igwmc/events/modflow2008/U.S. Society for Irrigation and Drainage Professionals. Urbanization of Irrigated Land and Water Transers. Scottsdale, AZ.www.uscid.org/08conf.htmlJUNE 2008June 3- 6June 4- 6June 8-12June 9-10June 9-11June 9-12June 24National Ground Water Association. The New MODFLOW Course. Las Vegas, NV. www.ngwa.org/development/shortcourses.aspxWater Education Foundation. Bay-Delta Tour. Sacramento-San Joaquin Bay, CA. www.water-ed.org/tours.asp#tourdatesAmerican Water Works Association. ACE08: Annual Conference and Exposition. Atlanta, GA. www.awwa.org/ace08/National Ground Water Association. Environmental Forensics: Methods and Applications (short course). Greenwood Village, CO.www.ngwa.org/development/calendar.aspxGroundwater Resources Association of California. Vadose Zone Hydrology, Contamination, and Modeling Short Course. Los Angeles,CA. www.grac.org/Utton Transboundary Resources Center, University of New Mexico School of Law. The Winters Centennial: Will Its Commitment toJustice Endure? Santa Ana Pueblo (near Albuquerque), NM. uttoncenter.unm.edu/winters_conference.htmlArizona Water Resources Research Center. The Importance of the Colorado River for Arizona’s Future. Phoenix, AZ.ag.arizona.edu/azwater/programs/conf2008/JULY 2008July 6-10July 14-18July 26-30Numerous agencies and organizations. Computational Methods in Water Resources: XVII International Conference. San Francisco,CA. www-esd.lbl.gov/CMWR08/HCI Publications. HydroVision 2008 (conference on hydropower). Sacramento, CA. www.hcipub.com/hydrovision/Soil and Water Conservation Society. 2008 Annual Conference. Tucson, AZ. www.swcs.org/en/conferences/2008_annual_conference/AUGUST 2008August 12-13Groundwater Resources Association of California. Climate Change: Implications for California Groundwater Management.Sacramento, CA. www.grac.org/climate.aspSEPTEMBER 2008September 7-10September 15-18September 20-24September 24-26WateReuse Association. 23rd Annual WateReuse Symposium: Water Reuse and Desalination. Dallas, TX.www.watereuse.org/2008Symposium/Index.htmlNational Ground Water Association. Fundamentals (Sept. 15-16) and Applications (Sept. 17-18) of Ground Water Geochemistry(short course). Denver, CO. www.ngwa.org/development/shortcourses/FundamentalsGroundWaterGeochemistry235.aspxArizona Hydrological Society and American Institute of Professional Geologists. 2008 Annual Symposium: Changing Waterscapes andWater Ethics for the 21st Century. Flagstaff, AZ. www.azhydrosoc.orgGroundwater Resources Association of California. 17th GRA Annual Meeting and Conference - Groundwater: Challenges to MeetingOur Future Needs. Costa Mesa, CA. www.grac.org/am08.asp42 • May/June 2008 • Southwest Hydrology

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