Groundwater:

MinnesotaDepartment of Natural Resources

Waters

October 2009

Plan to Develop a Groundwater Level Monitoring Network for the 11-County Metropolitan Area

DNR Information Center:

Web Address: mndnr.gov/waters

DNR Waters500 Lafayette RoadSt. Paul, MN 55155-4032(651) 259-5700

Twin Cities: (651) 296-6157Minnesota Toll Free: 1-888-646-6367 (or 888-MINNDNR)Telecommunication Device for the Deaf: (TDD): (651) 296-5484TDD Toll Free: 1-800-657-3929

This information is available in an alternate format on request.Equal opportunity to participate in and benefit from programs of the Minnesota Department of Natural Resources is available regardless of race, color, national origin, sex, sexual orientation, marital status, status with regard to public assistance, age, or disability. Discrimination inquiries should be sent to Minnesota DNR, 500 Lafayette Road, St. Paul, MN 55155-4049; or the Equal Opportunity Office, Department of the Interior, Washington, DC 20240.

This information is available in an alternative format upon request© 2009 State of Minnesota, Department of Natural Resources

Kelton Barr BraunIntertec,MinneapolisMark CollinsHDREngineering,Inc.,MinneapolisTimothy CowderyU.S.GeologicalSurvey,MinnesotaWaterScienceCenter,MoundsViewChristopher ElvrumMetropolitanCouncil,St.PaulJay FrischmanMinnesotaDepartmentofNaturalResources,St.PaulDon HansenU.S.GeologicalSurvey,MinnesotaWaterScienceCenter,MoundsViewPrincesa VanBuren HansenMinnesotaDepartmentofAdministration,EnvironmentalQualityBoard,St.PaulSharon KroeningMinnesotaPollutionControlAgency,St.PaulJeanette LeeteMinnesotaDepartmentofNaturalResources,St.PaulDave Leuthe (Chair)MinnesotaDepartmentofNaturalResources,St.PaulShannon LotthammerMinnesotaPollutionControlAgency,St.Paul

ACKNOWLEDGEMENTS to the GROUNDWATER TECHNICAL WORKGROUPThefollowingcommittee,listedwiththeircurrentaffiliations,collaboratedto

producethetechnicalbackgroundofthismonitoringplan.

Joy LoughryMinnesotaDepartmentofNaturalResources,St.PaulMike MacDonaldMinnesotaDepartmentofNaturalResources,St.PaulBill OlsenDakotaCountyWaterResourcesDepartment,AppleValleyHans Olaf PfannkuchUniversityofMinnesota,Dept.ofGeologyandGeophysics,MinneapolisSteve RobertsonMinnesotaDepartmentofHealth,St.PaulLanya RossMetropolitanCouncil,St.PaulJim StarkU.S.GeologicalSurvey,MinnesotaWaterScienceCenter,MoundsViewBrian StenquistMinnesotaDepartmentofNaturalResources,St.PaulDan StoddardMinnesotaDepartmentofAgriculture,St.PaulAndrew StreitzMinnesotaPollutionControlAgency,DuluthBob TippingMinnesotaGeologicalSurvey,St.PaulRay Wuolo

BarrEngineeringCompany,MinneapolisThe cost of producing this report is $23,560.00.

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EXECUTIVE SUMMARY

ThisreportisproducedinresponsetoMinnesotaSessionLaws2009Chapter37Section4Subd.3.,whichreadsinpart:

By October 1, 2009, the commissioner shall develop a plan for the development of an adequate groundwater level monitor-ing network of wells in the 11-county metropolitan area. The commissioner, working with the Metropolitan Council, the Department of Homeland Security, and the commissioner of the Pollution Control Agency, shall design the network so that the wells can be used to identify threats to groundwater quality and institute practices to protect the groundwater from degradation. The network must be sufficient to ensure that water use in the metropolitan area does not harm eco-systems, degrade water quality, or compromise the ability of future generations to meet their own needs. The plan should include recommendations on the necessary payment rates for users of the system expressed in cents per gallon for well drill-ing, operation, and maintenance.

BackgroundMinnesota’swatersupplyhaslongbeentakenforgranted.Thislegislationrecognizestheurgencyforsustainablewatermanagementandtheneedforanintegratedmonitoringnetworktohelpachievethatgoal.

Theaquifersunderlyingthe11-countymetropolitanareahaveprovidedarobustsupplyofwaterforanever-growingpopulationsincestatehood.Today,manycommunitiesinthemetropolitanareaare100%dependentongroundwaterfordrinkingwater(Figure1)anditisthesourceofdrinkingwaterforatleast75%ofallMinnesotans.Demandforgroundwaterforalluses,especiallypublicwatersupply,willcontinuetoincrease(Figure2).

Consideringtheknownrisksthreateningthesecriticalaquifers,moredecision-makersagreethatitisimperativetoincreaseeffortstolearnmoreaboutflowpathways,rateofwatermovementandothercharacteristicsofhowtheyfunction.Thecurrentmonitoringnetwork,basedlargelyonmonthlyindividualhandmeasurements,isinadequateforthelevelofunderstandingneeded.Automatedsystemscapableofmorefrequentmeasurementsareessential.Wecannotmanagewhatwedonotmeasure.

AdditionalinvestmentsareneededtounderstandandprotectgroundwatersystemssothatfuturegenerationswillalsohaveanabundantsourceofcleanwaterthatissointegraltoMinnesota’senviablequalityoflife.

Languageinthislawcoversmajorworkresponsibilitiesforseveralagencies,includingtheDepartmentofNaturalResources,the

PollutionControlAgency,theDepartmentofAgriculture,theDepartmentofHealthandtheMetropolitanCouncil.Priortopassageofthislaw,theseagenciesalongwithnumerousotherpartnerswerealreadyworkingtogethertoaddressmorecoordinatedapproachestosustainablewatermanagement.Thisreportwascollaborativelyproducedbytheseagencies.

Therearenumerousinitiativescurrentlyunderwaythat

Figure1:Dependencyongroundwaterfordrinkingwatersupplybymunicipalityasapercentoftotalwaterused.

Figure2:Groundwateruseinthe11-CountyMetropolitanAreainbillionsofgallons.

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willcontinuetomovethestateforwardinaddressingtheveryissuesidentifiedinthislaw.Nevertheless,weappreciatethelegislativesupportanddirectionthislawbringstohelpkeepfocusontheimportanceofachievingsustainablewateruseinthegreatermetropolitanarea,aswellasstatewide.

Beginning with the first part of the legislative requirement:By October 1, 2009, the commissioner shall develop a plan for the development of an adequate groundwater level monitoring network of wells in the 11-county metropolitan area.

TheattachedreportentitledPlantoDevelopaGroundwaterLevelMonitoringNetworkforthe11-CountyMetropolitanAreaconstitutesthemajorbodyofworkrelatedtothisreport.Thisreportidentifiesalong-termplanforthedataandmonitoringsystemsneededtomorefullyunderstandtheseaquifersandflowpathways.Thatinformationwillultimatelyenableustobetterprotectlong-termsupplies,preventwaterqualitydegradation,andensurethatwaterusedoesnotharmecosystems.

Theplan,basedontheNationalFrameworkforGroundwaterMonitoringintheUnitedStates,istailoredtomeetMinnesota’sneeds.TheGroundwaterTechnicalWorkGroup,comprisedlargelyoftechnicalgroundwaterprofessionalsfromtheU.S.GeologicalSurvey,MinnesotaGeologicalSurvey,UniversityofMinnesota,MetCouncil,thedepartmentsofNaturalResources,PollutionControl,Health,andAgriculture,EnvironmentalQualityBoard,DakotaCountyandtheprofessionalconsultingfirmsofBarrEngineering,BraunIntertec,andHDR,provideddirection,input,contentreviewandguidanceinthedevelopmentofthisplan.

Additionally,weusedguidanceandrecommendationsfromGroundwaterWorkshopssponsoredbytheFreshwaterSocietyandtheUniversityofMinnesotaWaterResourcesCenter,theAmericanWaterResourcesAssociation,theEQB,andothernationallyrecognizedtechnicalreportsandpapersonthetopicofsustainablegroundwatermanagementinproducingthisplan.

Developinganintegratedmonitoringnetworkanddatamanagementsystemcalledforinthisplanwillrequirebothpublicandprivateinvolvementandinvestmentinordertoachievethedesiredgoals.Itisessentialtorecognizethattheseinvestmentswillbemuchsmallerthanthecostofmanagingsupplyconflicts,remediationofthreatstowaterqualityandecosystemhealth,andfuturetreatmentofimpairedgroundwatersuppliesifourcurrentamplesuppliesofrelativelycleanwaterarepermanentlyharmed.

Sinceanetworkmustbeviableforalongperiodoftime,dedicatedorendowedfundingisrecommendeddueto:

theextensiveamountofknowledgeneededtobecol-lectedaboutthesystemsthroughresearch,samplingandmonitoringpoints;

theresearchrequiredtogainagreaterunderstandingofthegeologicprocessesthatformedthemultipleaquiferlayersthatareburiedbeneathus;and

thedataandinformationsystemsthatmustbebuilttoenableeasyaccessto,andsharingof,historicinfor-mationinconjunctionwithnewdatastreamsthatwillbeaddedonanon-goingbasis.

The second part of the legislative requirement states:The commissioner, working with the Metropolitan Council, the Department of Homeland Security, and the commissioner of the Pollution Control Agency, shall design the network so that the wells can be used to identify threats to groundwater quality and institute practices to protect the groundwater from degradation.

Thegroundwaterlevelmonitoringnetworkplanidentifiedinthefirstpartwillnotreplacetheneedfortheexistingandseparateauthoritiesandprogramsthatareinplaceanddesignedtoidentifythethreatsandprotectgroundwaterfromdegradation.Multi-agencycoordinationisattheheartoftheGroundWaterProtectionActandishowagencieswilloperatetoamuchgreaterdegreegoingforward.Werecognizethatwemust“Dotogetherwhatwecan’tdoalone.”

LedbytheDepartmentofAgriculture,thePollutionControlAgencyandtheDepartmentofHealth,incollaborationwiththeDepartmentofNaturalResourcesandtheMetropolitanCouncil,aninteragencygroundwatermonitoringstrategyandgroundwaterprotectionstrategyareunderdevelopmentthatwillenhanceandsupportthisplanfromawaterqualitymanagementaspect.Allmonitoringwellsinstalledunderthisplanwillbesampledforabasicsetofwaterqualityparameters.

TheMPCAandMDAhaveplanstomeettheirstatutoryresponsibilitiestoimprovemonitoringtohelptrackbothknownandemergingthreatsinordertoprotectgroundwaterfromdegradation.Thoseplansshouldbeutilizedtoprovidethebasisforcontinuedsupportandfundingforwaterqualitymanagementbeyondneedsdescribedinthisplan.

Beyondagencyefforts,localgovernmentlandusemanagementdecisionsmustavoidand,wherepossible,reversetrendsthatthreatenouraquifers.Unsustainableusagedemandsandtheintroductionofpollutantswillultimatelyresultinlimitsonavailabilityandsignificantlyhigherlong-termtreatmentcostsforpresentsupplies.Successwillnotcomeuntilalldecision-makersunderstandtheimpactsoftheirdecisionsongroundwaterresources.

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The third part of the legislative requirement states:The network must be sufficient to ensure that water use in the metropolitan area does not harm ecosystems, degrade water quality, or compromise the ability of future generations to meet their own needs.

Theultimatepurposeofthemonitoringnetworkanddatamanagementsystemistoprovidetheinformationthatwillenabledecision-makerstounderstandthethreatstoecosystemhealth,waterqualityandsustainablesuppliesforfuturegenerations.Welldatawillenableustobetterunderstandtheflowpathwaysandrateofwatermovementofwaterthroughsubsurfacelayers.Usingimprovedmodelsandactualmeasurementstounderstandtheamountandrateofwatermovementinto,throughandoutofthedifferentaquiferswillenableustobettermanagesupplyanddemand.Ecosystemmanagersandbothwaterqualityandwatersupplymanagersneedthisinformationtomakemoresustainabledecisions.Allwateruserswillbenefitfromasystematicprogramforlong-termcollectionofwaterlevelandchemicaldata.

Ecosystemimpactsaredifficulttomeasurefortwoprimaryreasons.First,thereisalackofknowledgeabouthowmuchgroundwaterflowsfromaquiferstosurfacewatersystems,exceptwhereintensivemonitoringhasbeenundertakentoaddressknownimpactsfrompumping.Second,wedonothavesufficientunderstandingofallthelifecyclewaterneedsofalltheplantsandanimalsthatmakeupanecosystemandhowchangesinvolumeofgroundwaterflowmightaffecttheirindividualorcollectivehealth.

Wewillcontinuetoimproveourunderstandingofsitespecificmanagementneeds,expandmonitoring,andrequirespecificstudieswheremodelinganddatasuggestecosystemharmmightoccurfromoveruseofanaquifer.Whereknownsensitiveresourcessuchascalcareousfens,troutstreams,lakes,wetlandsandstreamsareatpotentialriskbasedonouranalyses,DNRcurrentlyusesanadaptivemanagementapproach.Adaptivemanagementisastructured,iterativeprocessofdecisionmaking,withagoalofreducinguncertaintyviasystemmonitoring.Monitoringaccruesinformationneededtoimprovefuturemanagement.Adaptivemanagementcanbecharacterizedas“learningbydoing.”

TheDNRwillworktodevelopamonitoringplanoverthenextfewyearsthatwillbetteraddressecosystemhealth.Theestablishmentofthemonitoringnetwork,outlinedinourresponsetothefinallegislativerequirementbelow,willbeanimportantsteptoimproveourunderstandingofwatermovementinouraquifersasapredictivetoolforprotectingecosystemhealth.

The fourth and final part of the legislative requirement states:The plan should include recommendations on the necessary payment rates for users of the system expressed in cents per gallon for well drilling, operation, and maintenance.

Whilethefirstthreepartsofthelegislativerequirementaddressbroadconceptsonsustainablemanagementofourgroundwatersysteminthe11-countymetropolitanarea,thisfinalpartwillbelimitedtoworknecessarytounderstandandsustainablymanagethewatersupply.

Toaddressmonitoringneeds,a“backbonenetwork”forlong-termgroundwaterlevelmonitoringmustfirstbeestablishedforthe11-countymetropolitanareaandultimatelyexpandedstatewide.Thedesignofthisnetworkwillincludealong-termplanforthecollectionofdata,developmentofsystematicmonitoringsystems,andcreationofareal-timewaterlevelinformationdatamanagementsystemthatwillhelplocalandstatewatermanagersprotectlong-termsupplies.Developmentofthemonitoringsystemwilloccursequentiallyasdatafromeachsuccessiveyearinformandguideplacementofadditionalwellsinsubsequentyears.

Monitoringisasharedresponsibilityofallusers.Coordinationofmonitoringattheaquiferlevelratherthanjurisdictionallevelismoreappropriatesinceimpactsofgroundwaterusecanoccurfarfromthepointoftaking.Also,nojurisdictionalboundaries,notevenwatersheddistrictboundaries,arenecessarilyaccurateforpurposesofgroundwatermanagement.Whilethebackbonenetworkwillprovideessentialdataonhowwatermovesthroughtheaquifers,toplanforsustainablesupplieswewillalsoneedwateruserstoaccuratelyreportwaterlevelinformationfromtheirproductionwellsandlocalgroundwaterlevelmonitoringwellsforinclusioninthedatamanagementsystem.

Ourinitialestimationforanadequate“backbone”waterlevelmonitoringnetworkforthe11countymetropolitanareawillconsistofalluseableexistingmonitoringlocations,whichisestimatedat200sites.Itwillalsorequireestablishmentof60well“nests”consistingofaseriesofcloselylocatedwellsineachofthemonitoredsubsurfaceformationsataselectedlocation.Allwellswillneedtobeinstrumentedwithautomateddatasystemsandeachofthewellnestswillneedtobeinstrumentedwithreal-timeaccesstotheautomateddatasystems.

Costsincludewelldrillingandconstruction,monitoringequipmentandinstallation,ongoingoperationsandmaintenance,datastoragesystemcosts,landrightscostsforthewellnestlocations,andcostsforinterpretationandanalysisofthedata.Itisestimatedthiswillcost$8,861,150overafouryearperiod.Theannualon-goingcostforoperationandmaintenanceofthewaterlevelmonitoring

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networkisestimatedtobe$825,000.Thefollowingtabledescribescostcomponentsforthefirstfouryearsofnetworkbuild-outandforsubsequentyears.

Anestimated140billiongallonsofgroundwaterperyearareusedinthe11-countymetropolitanarea.Duringthefouryearsofnetworkbuildout,thecostswillbe:

$8,861,750.00 /4 years = $2,215,437.50 per year

$2,215,437.50 per year / 140 billion gallons per year= $0.00001582 per gallon =

0.001582 cents per gallon, or

$15.82 per million gallons.

Table1:CostsfortheCreation,Maintenance,andOperationofaGroundwaterLevelMonitoringNetworkforthe11-CountyMetropolitanArea.

$825,000.00 per year

$825,000 per year / 140 billion gallons per year= $0.00000589 per gallon =

0.000589 cents per gallon, or

$5.89 per million gallons.

Oncethebackbonenetworkisestablished,costsforongoingoperationandmaintenancewillbe:

Year 1 Year 2 Year 3 Year 4Total

DevelopmentSubsequent

Years

Total Wells in Backbone Network 80 175 270 380 380 380

Backbone Network Establishment: Well Drilling, Easements, Instrumentation, Operation and Maintenance 1,083,400$ 1,310,750$ 1,440,600$ 1,627,000$ 5,461,750$ 627,000$

Technical Support / Quality Control / Groundwater Analysis 350,000$ 350,000$ 350,000$ 350,000$ 1,400,000$ 105,000$

Data Management and Access through Web Portal 500,000$ 500,000$ 500,000$ 500,000$ 2,000,000$ 93,000$

$ 1,933,400 $ 2,160,750 $ 2,290,600 $ 2,477,000 $ 8,861,750 $ 825,000

Dollars per Million Gallons 13.81$ 15.43$ 16.36$ 17.69$ 15.82$ 5.89$

Cents per Gallon 0.001381 0.001543 0.001636 0.001769 0.001582 0.000589

Notes: All values 2009 dollarsNotes: All values 2009 dollars

By the end of the fourth year of network build-out, the backbone network will consist of 60 nests for which data are transmitted real time (approx. 3 wells per nest) and 200 monitoring wells with dataloggers

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INTRODUCTION

TheAmericanWaterResourcesAssociation(2009)identifiedthirteenwaterresourcechallengesfacingwaterprofessionalsinthenextdecade;sevenofwhicharelistedhere:

Developingmoderate,flexiblepoliciesaimedatrea-sonableuseofwaterresourcesinordertosustainwaterquality,andtosustaingroundwaterandsurfacewatersupplies.

Acquisitionofcrediblelong-termdataandassess-ments,andthedevelopmentofreliablepredictivemodels.

Integratingwatershed-levelthinkingintowaterre-sourcesmanagementdecisiondevelopment.

Developingstrategiestorespondtotheeffectsofcli-matechangeonwaterandtheenvironment.

Maintaining/upgradingthenation’sphysicalwaterin-frastructure.

Protecting/restoringthenaturalinfrastructure(water-sheds,springs,streams,floodplains,andwetlands).

Maintaining/enhancingin-streamwaterqualityforecosystemsupport.

EachofthesechallengesappliestoMinnesota.Allsevenchallengesmustbefacedinordertoaccomplishthegoalofcleanandplentifulwatersuppliesforfuturegenerations.Minnesota’sdependenceongroundwaterisgreat,eveninthe11-countyMetropolitanArea(metropolitanarea)wherebothMinneapolisandSt.Paulmakeuseofsurfacewater.Wateruseisrisingandthetrendisexpectedtocontinueduetopopulationgrowthdespiteconservationefforts.

Sustainabilityofwaterresourcesingeneralandgroundwaterinspecificisanurgentconcernandfederalandstateactivitiesareongoing.ThemonitoringframeworkpresentedinthisdocumentinlargepartisanadaptationoftheNationalFrameworkforGroundwaterMonitoringintheUnitedStates(AdvisoryCommitteeonWaterInformation,SubcommitteeonGroundwater,2009)andoftheWaterQualityMonitoringFramework(Figure3;NationalWaterQualityMonitoringCouncil,2003)toMinnesota’sneeds.Thecurrentstatusofcoordinated,long-termmanagementeffortsaredocumented.TheseeffortsareinneedofimprovementifMinnesotaistomeethumanandecosystemneedsforwater.

Aprocessforimprovementofmonitoringnetworksinsupportofsustainablewaterresourcesmanagementisoutlinedherein.Thisreportisproducedinresponseto

MinnesotaSessionLaws2009Chapter37Section4Subd.3.,whichreadsinpart:

By October 1, 2009, the commissioner shall develop a plan for the development of an adequate groundwater level monitor-ing network of wells in the 11-county metropolitan area. The commissioner, working with the Metropolitan Council, the Department of Homeland Security, and the commissioner of the Pollution Control Agency, shall design the network so that the wells can be used to identify threats to groundwater quality and institute practices to protect the groundwater from degradation. The network must be sufficient to ensure that water use in the metropolitan area does not harm eco-systems, degrade water quality, or compromise the ability of future generations to meet their own needs. The plan should include recommendations on the necessary payment rates for users of the system expressed in cents per gallon for well drill-ing, operation, and maintenance.

InFebruary2008,DNRprovidedtheEnvironmentalandNaturalResourceDivisionoftheMinnesotaHouseFinanceCommitteewithageneralizedinitialestimateoftheneedtoaddapproximately6,000additionalgroundwaterlevelmonitoringwellsstatewidetothe750wellsthatarecurrentlymonitored.Anestimateddrillingbudgetof$120millionin2008dollarswouldbeneededtomeetthisneed.Aplantodevelopthemetropolitanareaportionofthegroundwaterlevelmonitoringnetworkispresentedinthisdocument.

Figure3:NWQMCproposedframeworkforwaterqualitymonitoringprograms(NWQMC,2003).

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NETWORK DESIGN AND STANDARDS

Groundwatercannotbemanagedinisolation.Climateandsurfacewatermonitoringnetworksmustalsobeimprovedandsustained;worktodosohasbeenenhancedbyfundingprovidedundertheCleanWaterLegacyAct.Geologicandhydrogeologicmappingareindispensableandmoreofthismappingworkremainstobedonewithinthemetropolitanarea.Themajorityoftheareaisunderlainbyathicksequenceofproductiveaquifers(Figure4).MostofwhatisknownabouttheseaquifershasbeenlearnedaswellshavebeendrilledandpumpedandasinformationhasbeencompiledandanalyzedinCountyGeologicAtlases.Figure5showsareaslackingadequateinformationaboutaquifersfortheMetropolitanCouncil’sregionalgroundwatermodelingpurposes.Figure6showsprogresstowardcompletecoverageofthemetropolitanareawithCountyGeologicAtlases,whichwillprovideagreatportionofthenecessaryinformationforimprovingtheunderstandingofaquiferpropertiesandrelationshipsbetweenaquifersandsurfacewaterresources.

Thereistruthinthestatement“youcan’tmanagewhatyoudon’tmonitor”.Continuedmonitoringoverextendedtimecreatesthelongtermrecordsneededforresourcemanagement.“Typically,collectionofwater-leveldataoveroneormoredecadesisrequiredtocompileahydrologicrecordthatencompassesthepotentialrangeofwater-levelfluctuationsinanobservationwellandtotracktrendswithtime”(Figure7;TaylorandAlley,2001).Accuratewaterusedatamustalsobeavailable.

Climatenormsareestablishedover30-yeartimeintervals.Chemistryofgroundwatercanchangeoversimilartimescales.Similarly,observationwellrecordsincreaseinvalueasmorewellshavealengthofrecordofthirtyyearsormore.Agroundwaterlevelmonitoringnetworkthatismaintainedindefinitelythroughfundingcycleswillbeastablebackbonenetworkprovidinginformationneededforsustainablewatermanagement.

Network goalsDatacollectioneffortsthathavedefinedandacceptedknowledgegoals,documentednetworkdesign,andplansfordesignrevision,dataanalysisandusearepreferred.Minnesota’snetworkwillofnecessitybecomprisedofanetworkofnetworks.Wewillsharedataamongthesenetworksandusethemergednetworkstoformtheactivewaterlevelmonitoringsystem.

Knowledge goals

Fundamentalquestionsthatnetworkdesignmustberesponsivetoinclude:

Howdoesthisaquifersystemworkandhowmightweusethenetworktotestconceptualmodelsofthehydrogeologicsetting?

Whatistheunstressedconditionofthemonitoredaquifer?

Howcanweusethenetworktodefinethedirectionandgradientofgroundwaterflow?

Howisgroundwaterchemistrychangingovertime?

Whatarethesources/causesofthesechanges?

Howmightweusethenetworktoestablishback-groundlevelsofwaterqualityindicators?

Whatarethegroundwaterleveltrends?

Whatarethelong-termandannualchangesingroundwaterstorageduetoeffectsofclimateandofwithdrawals?

Howmuchgroundwatermovesthroughthesystem?

Howmuchgroundwatercontributionisneededbycriticalecosystemstomaintainminimum(non-lethal)andmaximum(successfulreproductionofsustainablepopulations)suitableconditions?

Whatistherelationshipbetweenclimate,groundwa-terstorage,groundwaterappropriations,andground-watercontributiontocriticalecosystems?

Whataretheeffectsofperiodsofdroughtandaboveaveragerainfall?

Whatarethelong-termeffectsofclimatechange?

Whataretheeffectsofgroundwaterwithdrawals?

Howdogroundwatermanagementeffortsimpactchemistry,recharge,discharge,ecosystems,etc.?

Design Criteria

Networkdesigndeterminesthesamplinglocations,frequencyofmonitoring,variablestomeasure,andthestandardsforday-to-dayoperationoftheentiresystem.Designcriteriashould:

Answertheknowledgegoalsdefinedabove.

Describeatransparentnetworkstructure.Itshouldbeclearhowthepartsfittogethertocreateawholesystemmoreusefulthantheindividualparts.

Clearlydefinebenefitsresultingfrominvolvementofmultipleagenciesandlocalunitsofgovernment.

Identifytheaquifersandaquifersystemstobemonitored.

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Figure4:Extentofmajorbedrockaquifersinthemetropolitanarea.

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Figure5:Areaslackingadequateaquiferinformationforgroundwatermodelingpurposes.

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Figure6:StatusofCountyGeologicAtlases.

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Figure7:Typicallengthofwater-level-datacollectionasafunctionoftheintendeduseofthedata(TaylorandAlley,2001).

Identifyadditionalnaturalfeaturestobemonitoredsuchassprings,stream,andlakes.

Incorporatemeasurementofthevolumesofwatermovingthroughthesystem(fluxmonitoring)intheformofstreamflows,springdischarge,rainfall,infil-tration,evapotranspirationandrelatedaspectsofthehydrologiccycle.

Incorporateinitialchemistrymonitoringtoimproveexistinggroundwaterqualitymonitoringnetworks.

Useastandardprocessbasedonaconceptualunderstandingoftheaquifersystemtoselectmoni-toringlocationsinthreedimensions.Wellscompletedatdifferentdepthsatacommonlocationarecalledwellnests.Wellnestsarethemostefficientmethodofmonitoringinthreedimensions.

Useaniterativeprocessthatincorporatestheresultsofhistoriclongtermmonitoring,synopticmeasure-mentsandregionalgroundwatermodelingtoguidenetworkdevelopmentandmonitoring.

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Useastandardprocesstodeterminemonitoringfre-quenciesbasedonlocationandhydrogeologiccondi-tionsaswellasanyadditionalintendedusesofthewaterleveldata.

Establishaminimumgroundwaterlevelsamplingfre-quencyforthebackbonenetwork.Specialprojectsmayincreasesamplingfrequency.

Identifyrelevantdesignelementssuchaswellcon-structionthatimpactnetworkeffectiveness.

Establishstandardfieldandlabprotocolstoensurecomparabilityovertime.

Establishstandarddataexchangeprocesseswherebyallcooperatorsprovidestandardizeddatasubmis-sions.

Ensurethatmonitoringlocationsmeetthegoalsofmultiplenetworkpartners.

Establishstandardsforwellconstructionandmain-tenance,includinghydraulictestingandsurveyingofwaterlevelmeasurementpointsrelativetoperma-nentsurveyreferencepoints.

Createanaccessibledatamanagementsystemwithredundantback-upsthatwillallowcooperatorstouploadandverifyindi-vidualmeasurementsandelectronicfilesoftime-seriesdatacollectedbyautomateddataloggers.

Providedataimmediatelyforman-agementdecisionsandnetworkmain-tenancethroughweb-baseddataac-cessinmultipleformats(e.g.tabular,hydrograph,etc.)summarystatisticscalculatedoverselectableintervals,andallowdownloadingofthequality-controlleddata.

Analysis and Use of Monitoring Data

Dataanalysisandqualitycontrolprotocolswillbedevelopedforthebackbonenetworkandeachsubnetworkusingthebestavailableinformation.Suchprotocolswillbeincludedinthedesignandsubsequentredesignsoftheoverallnetwork.Provisionsmustbemadetoevaluatetheseprotocolsperiodically.

Reportingprotocolsshouldfollowasimilarmodelandincludepublicwebaccessreportingstandardswhichmustbeautomated.Userswillquerythedatasetandcreatesummariesandother

derivativenetworkproducts.Individualusersofwaterateveryscaleareaprimaryaudience;understandingandprotectingMinnesota’sgroundwaterresourcesforcurrentandfutureuseswilldependontheinvolvementofallusers.

Ascheduleforreviewandrefinementofnetworkdesignandprotocolsshouldbeestablishedattheonset.

Types of Networks and Monitoring CategoriesSeveralsetsofdefinitionsexistfordifferenttypesofmonitoring.Forexample,thetermsbaselinemonitoring,ambientmonitoring,andbackgroundmonitoringaresimilar.Monitoringcanbelongtermorshortterm,continuousintimeorcontinuousinspace,sampleselectioncouldberandomorpredetermined.Wedefinefourtypesofmonitoring:BaselineMonitoring,SurveillanceMonitoring,TrendMonitoringandSpecialStudyMonitoring.ThesetermsfollowtheusageintheNationalFrameworkforGround-WaterMonitoringintheUnitedStates(NationalFramework)(AdvisoryCommitteeonWaterInformation,SubcommitteeonGroundWater,2009;Figure8)anddefinepurposesformonitoring.Agivenwell’srecordofwaterlevelmeasurementsmaybeusedformultiplepurposesovertimeorsimultaneously.

Figure8:Networktypesandrelationshipsamongnetworks(NationalFrameworkforGround-WaterMonitoringintheUnitedStates,AdvisoryCommitteeonWaterInformationSubcommitteeonGroundWater,2009).

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Werefertothemonitoringnetworkforthemetropolitanareaasa‘backbone’networkinparttoavoidtheinherentassumptionsandlimitationsincludedinusinganyoftheestablishedlabels.

Thisdiscussionfocusesonanetworkcreatedtomonitorwaterlevels,butthegoalisalsotoensurethatthenetworkwillbeusefulforwaterqualitymonitoringasneeded.

Baseline Monitoring

Baselinemonitoringmayalsobecalledbackgroundmonitoring,conditionmonitoring,orambientmonitoring.Itistypicallylongtermandcontinuousintime.Baselinemonitoringmaybeusedtoestablishwaterlevelsatalocationwithinanaquiferpriortotheinterventionofastressorimpact,i.e.priortoaquiferdevelopment.Baselinemonitoringtakesplaceatallmonitoringlocationsduringthefirstseveralyearsasthewaterlevelsaremeasuredandabaselinepatternisestablished.Inanothersense,somewellsmaybeselectedforbaselinemonitoringbecausetheyarenotexpectedtorespondtoananticipatedstressorimpact.Forwellsinstalledafterastressonthesystemhasbegun(inanexistingwellfield,forexample),‘baselinemonitoring’mayrevealanongoingtrendinwaterlevels.

Monitoring for Special Studies

RobertC.Ward,amonitoringnetworkexpertwhohaslongstruggledwiththeseissues,states:“Itisdifficultforonemonitoringsystemtoanswerthe“what”and“why”questionsatthesametime”(Ward,1989).Baseline,surveillance,andtrendmonitoringtypicallydealwiththe“what”question.Once,forexample,the“whatisthequalityofthewater”questionisansweredandrevealsaproblem,thenspecialstudymonitoringcancomeintoplaytoaddressthe“why”or“howfarhavewecomeinfixingthisproblem”questions.Thistypeofmonitoringisalsotermedtargetedmonitoring,compliancemonitoringoreffectivenessmonitoringandthenatureofthemonitoringisentirelydependentonthestudyparameters.

LimitationsTheultimatepurposeofmonitoringistoinformpolicydecisionsandmanagementactions.Groundwaterquantityandqualityinformationcannotpreventorsolveproblemsonitsown.Nosinglenetworkcanaddressallgroundwaterconcerns,butaregionalbackbonenetworkisextremelyimportantbecauseitcanprovideinformationontrends,dataformodeling,andassistinproblemidentification.Effortstoaddressspecificconcernswillusuallyrequirethatmoredetailedinformationbeaddedtothatwhichcanbeobtainedfromthebackbonenetwork.

Formanagementtobeeffective,anumberoffactorsoutsidethecontrolofgroundwaterspecialistsmustbeaddressed:

Ingeneral,thepublic’sunderstandingoftheground-waterresourceispoor.Groundwatersystemsarehid-denfromdirectmeasurementandobservation;theyaremoredifficulttoperceiveandunderstand.

Short-termsocialandeconomicissuesmustnotvetogroundwatermanagementdecisions.

Riskstohumanandecosystemhealthmustbeevalu-atedand,wherethereisuncertainty,humanandeco-systemhealthmusttrumpotherneeds.

Costsofchangesinwaterusethatmustoccurtoen-suresustainability,includingcoststhataccruewhenpumpingisrestricted,mustbeapportionedoverthosebenefittingfromwateruse.Minnesotawaterlaw,forexample,allowsforreductionsinpermittedwaterusevolumesinawateruseconflictareatopro-tecttheresourceandhighestpriorityuses.

Aregulatoryframeworkisinplacethatallowsman-agerstosuspend(foraseasonalimpact)orterminate(forapermanentimpact)waterwithdrawalsthatwillpotentiallyimpairecosystemservices.Ifadequatemonitoringofbothsurfaceandgroundwaterresourc-esisinplace,regulatorswillbeabletomanagetopre-ventunintendedimpacts.

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Minnesotaemploysamulti-agencyapproachtogroundwatermonitoringandprotection.Ittakestheconcertedeffortofallagencies,alongwithlocalandfederalpartners,tobuildacomprehensivepictureofthestatusofthestate’sgroundwaterresources.Thesegroundwaterqualityandquantitydataareneededforwatersupplyplanning,permittingandotherregulatoryactions,bestmanagementpracticeimplementationandbetterunderstandingofsurfacewaterandgroundwaterinteractionsthathavethepotentialtoaffectwaterqualityandavailability.

A2004MemorandumofAgreement(MOA)betweentheMinnesotaPollutionControlAgency(MPCA),theMinnesotaDepartmentofAgriculture(MDA),andtheMinnesotaDepartmentofHealth(MDH)clarifiedtheagencies’respectiveroles(asspecifiedbystatestatute)inambientgroundwaterqualitymonitoring,andtheseagenciesoperateastatewideintegratedgroundwater-qualitymonitoringsystem.Figure9isagraphicaldepiction

ofagencyroles,includingthewaterquantitymanagementresponsibilityoftheMinnesotaDepartmentofNaturalResources(DNR).

OpportunitiestobetterconnecttheinformationcollectedbytheDNRforgroundwatermanagementwiththeMinnesotaPollutionControlAgency’s(MPCA’s)groundwaterqualitydatabase,theMinnesotaDepartmentofHealth’s(MDH’s)drinkingwaterwelldata,anddatacollectedbypublicandprivatewatersupplierstoenhancedataaccessibilityforgroundwatermanagementshouldbefurtherexplored.Amergeddatasetwillgivevaluetomanydifferentprograms.Therehasnotbeenadequatefundingtocompilecurrentandhistoricgroundwaterdatafromtheprogramsthatcollectit.Suchaneffortisapriorityforallstateagencies.Workhasbeguntorefinetheoptionsandcostsinvolvedincreatingacomprehensivegroundwaterdatamanagementsystemthatretrieves,validates,andbuildsonhistoricdatacollectionactivities.

SUMMARY OF MINNESOTA’S CURRENT NETWORKS

Figure9.Groundwatermonitoringrolesofthestateagencies.

DNR:Water supply/availabilityRecharge/infiltration

confining layer

confining layer

buried aquifer

bedrock aquifer

water tableaquifer

water table

water quality monitoring wells

water level monitoring wells

MPCA:Chemical releases Industrial pollutants

Agriculture:PesticidesFertilizer

MDH: Public water supply

Quality Quantity

Ground Water Monitoring Roles

water supply well water quality monitoring wells

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DNR – baseline, trend and surveillance monitoringDNR’sprimaryfocusisonwaterquantity.DNRmanagesacooperativewater-levelmonitoringnetworkcreatedinthe1930s(Figure10).Inthemetropolitanareathisnetworkconsistsof177wells.Itwasbuilt,withUSGSassistance,byincorporatingwellsusedforDNRandUSGSstudiesandwithsupplywellsthatarenolongerused.TheDNRandUSGSstudieswerenotdesignedtobepartofaregionalwater-levelmonitoringeffort.Manywellsarenotonlandunderpubliccontrolandcannotbeconsideredtobepermanentmonitoringlocations.SoilandWaterConservationDistrictsserveasdatacollectionagentsforthecurrentnetwork.

DNRhasagroundwatermonitoringworkgroupthatisinvolvedinplanningandguidanceforthecurrentnetwork.Oneimmediateconcernisthatthereiscurrentlynocomprehensiverepositoryforgroundwaterlevelmonitoringdata.TheDNRgroundwaterlevelmonitoringnetwork’sdatabaseisbeingreworkedtoprovideenhancedwebaccess,butdevelopmentofdatamanagement,processingandstoragetoolsfortimeseriesdataawaitsadequatefunding.

DNR’svisionforthefutureincludestheenhancementofthecurrentnetworkintoastate-of-the-art‘backbone’networkforgroundwaterlevelsandadatasystemorportalthatmeetstheneedsofthestate’swateragencies,othercooperatorsandthepublic.Thenetworkalsowillinformandprovidesupportforsubnetworks,includingsubnetworksbuiltprimarilyforwaterchemistryorqualitymonitoringgoals.

Tosupplementthecooperativenetwork,theDNRandpartnersconductedsynopticwaterlevelmeasurementsintheMetropolitanareaduringMarchandAugust2008(Figure11).Theresultsaresnapshotsofwaterlevelsandcanbecomparedseasonallyandwithothersynopticmeasurementstogainanunderstandingofmajorchangesingroundwaterstorageandflowovertime.Theseimagesfrom2008showthatgroundwaterwithdrawalshadcreatedaconeofdepressioninMt.Simonwaterlevelsandthatthisimpactwasmorepronouncedduringsummerwhenmorewaterwasbeingpumped.Synopticmeasurementsshouldberepeatedatfive-yearintervals.

OtherwaterlevelinformationcollectedbyandforDNRincludesaquifertestdataandpermit-requiredmonitoringdata:

DNR’saquifertestsareconductedtounderstandhowgroundwaterwithdrawalswillimpactthegroundwa-terresourcefromwhichthewaterisbeingpumped.Impactsonotherusersandothernaturalresourcesareevaluatedusingaquifertestinformation.ThesedataareprovidedtoMDHforsourcewaterprotec-tionplanning.

Permittedgroundwaterusers(Figure12)areoftenrequiredintheirpermittomeasureandreportwa-terlevelsinspecificwellswhenitisdeterminedthatmonitoringwillassisttheDNRinwatermanagement.Permit-requiredmonitoringdataareusedtoevalu-atewateravailabilityandpredictlong-termimpactsofgroundwaterwithdrawalsontheecosystemandonotherusers.

OngoingDNRgroundwaterlevelmonitoringnetworkprogramactivities:

ManywellsmeasuredaspartoftheDNRcooperativenetworkareinpoorconditionduetoage.Anongoinginventoryofwellsandwellconditionallowstheex-tentofdeferredmaintenancetobequantified(Table2).Somewellsneedtobereplacedandtheoldwellssealed;somewellsareinlocationsorarecon-structedtodepthswhichservedtheoriginalstudyneedsbutarenotneededforongoingmonitoringandshouldbesealed;somewellsneedpreventivemainte-nance.Allwellsshouldreceiveroutinemaintenance.

Wellplacementisbeingevaluated,bothtodeterminewhichofthewellsmentionedabovemayberedun-dantandtoproposelocationsfornewwells.Wheregapsareidentified,newwellsmustbedrilledorper-missiontomonitorappropriateexistingwellsmustbeobtained.MostrecentprogresshasfocusedontheMt.Simonaquifer;newwellshavebeensitedandmanyhavebeendrilled.

DNRstaffhavedevelopeddraftguidancedocumentsfortheimprovedDNRnetwork.Anynewwellsthatwillbedrilledandanyexistingwellsthatwillbepartofthe‘backbonenetwork’mustmeetthestandardsestablishedintheguidancedocumentsandbesuit-ableforlong-termmonitoringofatleasttwentyyears.Thesewellsmustalsobeconstructedtoal-lowforwaterqualitysampling.Abasicsuiteofwaterqualityparameters(pH,conductivity,temperature,cations,anions,tracemetals[includinglow-levelar-senic],tritium,andstableisotopesofhydrogenandoxygen),willberoutinelyanalyzedforeachwellwhenitiscompletedorwhenitisaddedtothenetwork.Repeatedsamplingandselectionofadditionalpa-rametersforanalysiswoulddependonthelocationandpossiblesubnetworktowhichawellmaybelong.MDHmonitoringwellfeesmustbepaidforallwells.

Waterlevelmonitoringtechnologyisimproving.Au-tomateddatacollectiontechnologywillallowbetterqualitydata(waterlevel,temperatureandconductiv-ity,forexample)tobecollectedatmorefrequentin-tervals.Thenominalone-monthsamplingintervalforwaterleveldataisnotadequateforsomeofthepur-posesforwhichthedatawillbeneeded,e.g.assess-mentofrecharge(DelinandFalteisek,2007).Timeandmoneymayultimatelybesavedbecausefewerroutinesitevisitswillberequired.

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Figure10:CurrentDNRobservationwellnetworkinthe11-CountyMetropolitanArea.

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Figure11:SynopticmeasurementresultsoftheMt.Simon-HinckleyAquiferfromMarchandAugustof2008.

Synoptic Water-Level Measurements Reveal Seasonal Changes

August,2008

March,2008

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Figure12:Permittedgroundwaterusersbyaquifer.

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Informationroutinelycollectedduringaquifertestsandthroughpermit-requiredmonitoringcannotcur-rentlybestoredinthedatabasethatholds‘tradition-al’DNRgroundwaterlevelmonitoringdata.Thedata-basestructuremustbechangedtoaccommodatethelargeramountsofinformationcollectedbydatalog-gers.Thenetworkupgradealsomustaddresscalibrationofdataloggerdata.

Thefollowingsectionsbrieflysummarizemonitoringeffortsbyotheragencies.Wewillcontinuetocloselycoordinatewiththeseeffortstocreateanintegratedwaterqualityandwaterquantitynetworkforthemetropolitanarea.

Table2:AllactivewaterlevelmonitoringwellsinthecurrentDNRCooperativenetworkwereevaluated.Seventy-sevenofthewellsneedmaintenanceorhaveaproblemthatmustberesolvedbeforethewellshouldbeconsideredforinclusioninthebackbonenetwork.Wellmaintenanceissuesarebeingaddressedasfundsallow.

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MPCA – trend monitoring and special studiesUndertheMOAwithMDHandMDA,theMPCAengagesinwaterqualitymonitoringtoassessthestatusandtrendsofMinnesota’sgroundwatersystemfornon-agriculturalchemicals.Thedatainformdrinkingwaterprotectionandsupplyefforts,identifiesthreatstogroundwaterquality,andprovidesinformationforTotalMaximumDailyLoadstudies,andguidesdevelopmentofbestmanagementpracticestoavoidfuturegroundwaterimpacts.

Ambient(i.e.baseline)groundwaterqualitymonitoringhasbeenconductedbytheMPCAsince1978todocumentthequalityofthegroundwaterresourcesstatewideandidentifytrends.Site-specificinvestigations(i.e.specialstudies)alsoareconductedbytheagencytodeterminetheextentofnon-agriculturalpoint-sourcecontaminationtothegroundwater,suchasfrompetroleumspillsorlandfills.

TheMPCA’scurrentambientgroundwaterquality

monitoringnetworkfocusesonaquifersthataremostsusceptibletopollutionfromhumanactivities,namelythesurficialsandandgravelandPrairieduChien-Jordanaquifers.Byfocusingonvulnerableaquifers,thenetworkprovidesanearlywarningofcontaminationintroducedintothegroundwatersystemandallowsforearlierdetectionoftrendsingroundwaterquality.

TheMPCAisintheprocessofenhancingtheambientnetworktodiscerntheeffectsofurbanlandusesongroundwaterqualityconditions.Atotalof150additionalmonitoringwellsareneededtoallowassessmentofwater-qualityconditionsandtrendsbyland-usesetting.Figure13detailstheMPCA’sambientnetworkandplannedadditionsinthemetropolitanarea.TheMPCAisworkingcloselywithstateagenciesandlocalgovernmentstositeandinstallnewwellstomeetwaterqualitymonitoringandothermonitoringneeds.FundshavebeenappropriatedfromtheCleanWaterfundtoinstallatleast60oftheneededmonitoringwellsduringfiscalyears2010-2011.

Figure13:MPCAambientwelllocations(43wells)andproposedexpansion(89wells).

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MDA – trend monitoring and special studiesThefocusofMDAmonitoringactivitiesisonwaterqualityimpactsfrompesticideuse.Specialstudymonitoringisprimarilyinresponsetosite-specificincidents.Baselinemonitoringforpesticidesisconductedthroughspeciallydesignedmonitoringwellinstalledadjacenttofarmfields.Dataareusedtoevaluatewaterqualityimpacts,theneedforalternativeapplicationmethodsandasameasureoftheoverallsuccessofchangesinpesticide

managementpractices.InthemetropolitanareatheMDAmonitorsgroundwaterimpactsfromagriculturalchemicalapplicationsintheruralfringesurroundingthesuburbanareaaswellasurbanpesticideuseimpactsincooperationwithMPCA.MDAalsoconductsorassistswithspecialstudiesofpesticidesindrinkingwaterwells.Figure14depictswellsthatarebeingsampledbyMDAinthemetropolitanarea.

Figure14:MDA2008groundwatersamplingsites.

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MDH – baseline and trend monitoringMDHengagesinstatewidemonitoringtoevaluategroundwaterchemistryconditions,toaidinvestigationofspecificproblems,andtodemonstrateeffectivenessrelativetoestablishedstandards.ThismonitoringandrelatedactivitiesconductedbytheMPCAandtheMDAaredefinedbyaMemorandumofAgreement.MostofMDH’smonitoringisgearedtowardssafeguardinghumanhealth,especiallywithregardtodrinkingwaterprotection.Figure15showsthedistributionofpublicwatersuppliersinthemetropolitanarea.MDHhaswaterchemistrymonitoringresponsibilityforallpublicwatersupplies.

Specificexamplesofsomeofthesemonitoringactivitiesarelistedbelow:

Condition monitoring

Occurrenceanddistributionofnaturallyoccurringcontaminantssuchasarsenicandradium.

Characterizationofgeneralaquiferchemistrybysam-plingselectedpublicwatersupplywellsstatewide(2010).

Effectiveness (compliance) monitoring

SafeDrinkingWaterActcompliancesamplingofallpublicwatersupplysystemsinthestate.Frequencyofsamplingandcontaminantsofconcernvarydepend-ingonmanyparametersincludingvulnerabilitytocontaminationandsystemtype,e.g.community,non-community.

Figure15:MDHPublicWaterSupplyWells.

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Arsenicandnitratesamplingofallnewwells.

Problem investigation monitoring

Perfluorinatedcompoundconcentrationanddistribu-tionintheeasternTwinCitiesmetropolitanarea;

Specialprojects,e.g.wellheadprotectionandhealthassessmentsofcontaminationsites.

WhilemostMDHgroundwatermonitoringactivitiesarefocusedonwaterquality,waterlevelinformationiscollectedaspartofaquifertestingprojectsforpublicwatersuppliers.Itisrecordedaspartofregulatoryprogramsassociatedwithwateruseandconstructionpermittingofnewwellsandthesealingofoldwells.

USGS - Aquifer monitoring and surveillance monitoringTheUnitedStatesGeologicalSurvey(USGS)monitorsthequantityandqualityofwaterinthenation’sriversand

aquifers,developstoolstoimprovetheapplicationofhydrologicalinformationandensuresthatitsinformationandtoolsareavailabletoallpotentialusers.MuchofitsmissionhasbeencarriedoutthroughtheCooperativeWaterProgram(CWP),acost-sharingpartnershipbetweentheUSGSandwater-resourceagenciesatthestateandlocallevel.Inthepast,especiallyinthe1960sand1970s,theUSGSconductedmanyCWPstudiesforwhichmonitoringwellsweredrilled.InmanycasesthewellsarenowbeingmeasuredaspartoftheDNRgroundwaterlevelmonitoringnetwork.TheUSGScurrentlymonitorslocationsinMinnesotaforgroundwaterlevelsandqualityinresponsetospecificrequestsforassistance,aspartofareal-timedatacollectionnetwork,andforspecialgroundwaterstudies.

OngoingUSGSspecialprojectmonitoringinthemetropolitanareainvolvesthenetworkofshallowwellsshowninFigure16.Thesewellsarebeingusedtoevaluatetheimpactsoflanduseongroundwaterquality.

During2008,theUSGSservedasleadagencyforthesynopticmeasurementofwellsintheTwinCitiesMetropolitanArea.

AsenvisionedintheNationalFramework,theUSGSshouldplayamajorroleincoordinationofthenationalgroundwatermonitoringnetworkfortheprincipalaquifersoftheUnitedStates.Anewfundingmodelisbeingdeveloped(NationalFrameworkforGround-WaterMonitoringintheUnitedStates,AdvisoryCommitteeonWaterInformation,SubcommitteeonGroundWater,2009),which,ifsuccessful,willallowUSGStomanagetheday-to-dayoperationsofthenationalnetworkandtofundlong-termmonitoringintheprincipalaquifersoftheUnitedStates.

Figure16:USGSmonitoringwellssampledtodetectimpactsoflanduseonwaterquality.

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Local Governments - trend monitoring and spe-cial studiesMonitoringisongoingatmanylevelsofgovernment.Severalcountiesareactivelyinvolvedinassessmentandmonitoringofgroundwaterresourcesasarewatersheddistricts,conservationdistrictsandothers.WashingtonCounty’sgroundwatermonitoringnetworkisshowninFigure17.ThenetworkconsistsofDNRandcountywells.

Themanagementgoalsofthestate’sgroundwaterlevelmonitoringnetworkwillbeattainableonlyifthebackbonenetworkisaugmentedbyhigh-qualitydatacollectedlocallyandsubmittedtothegroundwaterleveldatabase.Mostsuchdatawillbesuppliedbyusersunderconditionsoftheirpermits,therestwillcomefromsubnetworkssuchasWashingtonCounty’s.

Example of County Observation Well Network

Figure17:NorthernWashingtonCountygroundwatermonitoringnetwork(IntegratingGroundwaterandSurfaceWaterManagement-NorthernWashingtonCounty,EmmonsandOlivierResources,Inc.,2004).

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NETWORK DESIGN FEATURES AND SPECIFICATIONS

Agroupoftechnicalexperts,theGroundwaterTechnicalWorkgroup,convenedtodiscussthesustainabilityofgroundwaterinMinnesotawasqueriedaboutMinnesota’sgroundwatermonitoringneedstoprovideforbettermanagement.Thediscussioncenteredonwaterquantitydataneeds,althoughallweremindfulthatwherepossible,needsformonitoringofotherwaterparametersshouldalsobemet.Theresponsesfellintothreemainthemes,asfollows:

More instrumentation on wells and collection of data on more parameters —

Useofautomaticlevelrecordersanddataloggersforcontinuousgroundwaterlevelmonitoring.Increaseduseoftelemetrywouldallownearreal-timeresponsetoproblemsincludingequipmentmaintenanceissues.

Requiringwateruserstocollectandreporthigh-qualityinformationaboutwaterlevelsandwateruse.Whereappropriate,continuouswaterleveldatashouldberecorded.

Routinecollectionoftemperatureandconductivityinformationconcurrentwithwaterlevelmeasure-mentswhereappropriate.

Additional well installations, preferably nests (which are multiple wells finished in different aqui-fers at a given location) —

Nearsurfacewatergagingstations,springs,andnearlakesandwetlandstoallowassessmentofground-water-surfacewaterinteraction.

Nearusersoflargequantitiesofwater,alongwithcontinuousrecordsofpumping.

Toassessverticalgradientsbetweenaquifersandinareaswherebedrocksubcropsbeneaththicklayersofunconfinedmaterial.

Includewellsinconfiningunitsbetweenaquifers.

Installedatapproximategroundwatersheddividesandregionaldischargeareasalongmajorriverstoenhanceunderstandingofbaseflowcontributingareas.

Existingdeepwellsingoodconditionwhichareproposedtobesealedshouldbeevaluatedforpossiblesuitabilityasobservationwellsunderthecriteriaestablishedforthenetwork.

New tools for working with data —

Softwareforworkingwithdata,especiallylongdurationtimeseriesdata.

Qualitycontroldataprocessingroutines.

Databaseanalysisroutinesthatscreenforanomalousdataentriesandassesstrendsinthedatabeingsub-mitted.

Asthegroundwaterlevelmonitoringnetworkisenhanced,allpartnerswillalsoworktoidentifyopportunitiesandneedsforexistingwaterqualitynetworksmanagedbyMPCA,MDAandMDH.

Monitoring Element GoalsQuantity (Levels, Flows, Rates of Use and Discharges)

Weatherandclimatedatausedtoestimatearealrainfallandevapotranspirationamountsareneededathighspatialresolutiontocomplementgroundwaterandsurfacewaterdata.Usersofgroundwaterannuallyreportmonthlywateruse.Surfacewaterelevationsarealsoneededathighresolutiontocomputechangesinstoragewhichisespeciallyimportantforcomputationsofbaseflowtostreamsandrivers.Thereisaneedtomonitorstreamflowsthroughthewinterforassessmentofthecontributiontobaseflowfromgroundwater.

Quality (Constituents of the Water)

Physical,chemical,andisotopicsamplingforage-datingandsourceassessmentshouldbeconductedonallwellsinthebackbonenetwork.Thissamplingshouldoccurwhenawellisconstructedor‘adopted’intothenetwork.Thisbaselinewaterqualitydatacanthenbeevaluatedbythegroundwatermonitoringworkgrouptodeterminethefrequencyandlistofconstituentsforanyadditionalqualitymonitoringneededtomeetspecificsubnetworkgoalsincludingspecialstudies.

Inadditionto“routine”monitoringofgroundwaterconditions,datashouldperiodicallybecollectedonthepresenceandtrendsofcontaminantsthatarejustbeginningtobeinvestigatedandarenotwellunderstood(suchasendocrinedisruptingcompounds).Thismonitoringshouldstartwherethedatawillbemostusefultoinformhealthriskassessmentsandpolicydevelopment.

Resources MonitoredTheprimarymanagementgoalistomonitorwaterlevelsinthemajoraquifersystemsinuseinthemetropolitanarea.Managementofaquifersystemsnecessarilyreliesonathoroughunderstandingofinputsandoutputs.Thuswemustalsohaveaccesstohighqualityinformationaboutstreamflowsinthemajorriversandstreamsinthemetropolitanarea.UndertheCleanWaterLegacyAct,theMPCAandDNRarecooperating(alongwithUSGS,theMetropolitanCouncilandlocalpartners)toenhancethecollectionandanalysisofstreamflowmonitoringdata.The

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MetropolitanCouncilisproposingtousenewmethodsforstreamgagingthatmayallowgroundwatercontributionstostreamflowinmajorriverstobecalculated.Additionalstreamgagingsitesonmajorriversandtributarystreamsandtroutstreamsmayneedtobeestablishedtomeetthegroundwaterlevelmonitoringnetworkgoalofunderstandingwaterflowthroughtheaquifersystemsofthemetropolitanarea.

Waterlevelsinwetlandsandlakesinmanycasesreflectthewaterlevelofthesurficialaquifer.Lakelevelandwetlandlevelmonitoringsitesmayneedtobeenhancedtogatherdataaboutthesurficialaquifer.Figure18showsexistingsurfacewatermonitoringlocationsthatprovideimportantinformationforgroundwatermanagement.Systematicimprovementsinthedistributionandqualityof

thesemonitoringpointsareadvisable.

Springdischargecomesdirectlyfromaquifers.Theinventoryofspringsinthemetropolitanareaneedstobecompletedandspringdischargemonitoringatkeylocationsbegun.

Groundwater and Ecosystem FunctionGroundwaterbothinfluences,andisinfluencedby,ecosystemfunction.Groundwaterqualityandquantityinfluenceecosystemprocessesandservices,suchasplantproductivity,aswellasnativeplantandanimalcommunitycompositionandassociatedrarespecies.Functionalecosystems,in-turn,influencegroundwaterquality,suchasthroughbio-filteringprocessesandsedimentremovalthroughinfiltration,andinfluencegroundwaterquantity

Figure18:ActiveDNRsurfacewatermonitoringlocations.

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byfacilitatinggroundwaterrechargeandminimizingvariabilityingroundwaterrechargerates.

Ecosystem influences on groundwater

Afunctionalecosystemiscriticalformaintaininggroundwaterqualityandquantity.Wetlandsandothernaturalplantcommunitiesinterceptprecipitationandoverlandflowingwater.Thesenaturalsystemsactasfilteringagents,removingpollutantsandsedimentfromwaterasitinfiltratestothegroundwater.Nativevegetationandintactcommunitiesattenuateoverlandflowofwatertoriversandstreamsandfacilitategroundwaterrecharge.Rechargeinfunctionalecosystemscanalsooccuratasteadierpace,minimizingvariabilityin

groundwateravailability.

Groundwater influences on ecosystem processes and services

Ecosystemservicesarebenefitsprovidedbyecosystemstohumans.AccordingtotheUnitedNations2004MilenniumEcosystemAssessment,ecosystemservicescanbegroupedintofourmajorcategories:“provisioning,suchasproductionoffoodandwater;regulating,suchascontrolofclimateanddisease;supporting,suchasnutrientcyclesandpollination;andcultural,suchasspiritualandrecreationalbenefits”.

GroundwaterisitselfanecosystemservicethatisdependeduponbymostmunicipalitiesintheTwinCities

Figure19:Mt.Simonboundarystudymonitoringwelllocations.

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metroareaandthroughoutMinnesota.Thequantityandqualityofgroundwaterasadirectecosystemserviceisdiscussedinothersectionsofthisdocument.

Groundwater,inturn,affectsotherecosystemfunctionsandservices,suchasplantandanimalproductivity,andnutrientcyclingandtransport.Theinfluenceofgroundwaterontheseandotherecosystemcomponentsdependonahostofinterconnectedfactorsincludingtopography,soiltype,connectionsbetweenshallowwateranddeepwater,plantcommunitytype,watershedpositioninthelandscape,andpositionwithinawatershed.Thecombinationofthesefactorsmakecertainfeaturesofanecosystemmoredependentupongroundwaterfeatures.Monitoringmustaddressthesecomplexrelationships,andthefirststeptowardbetterunderstandingisinclusionofappropriatemonitoringsitesinthebackbonenetwork.

Monitoring Site Distribution GoalsThemonitoringnetworkmustcoverthearealextentofthemajoraquifersinthemetropolitanarea.Developmentofaconceptualmodelofthegroundwaterflowsystemineachmajoraquifermustunderliethenetworkdesign.Tothisend,wellsinthemajoraquifersthatextendoutsidethemetropolitanareamustalsobeincludedinthebackbonenetwork.Thesewellswillestablishboundaryconditionsformoredetailedassessmentsofwaterlevelchangeswithinthemetropolitanarea.Theongoingwell-drillingprogramtoexpandmonitoringoftheMountSimon-Hinckleyaquiferisanexampleofhowtheedgeof

amajoraquifercouldbemonitored(Figure19).AsimilareffortwillberequiredfortheedgeoftheFranconia-Ironton-Galesvilleaquifer(TunnelCity-Wonewocaquifer).Completionoftheremainingcountygeologicatlasesforthemetropolitanareaandupdatesforolderatlaseswillassistwiththiseffort.

Groundwatermonitoringlocationsmustbeadequateforregionalplanningandenoughdetailmustbeprovidedtoallowadaptivemanagementinresponsetoobservedchangesinwaterlevels.Groundwatermonitoringlocationsmustalsobeadequateforwatershed-levelassessmentofgroundwater–surfacewaterinteraction.

Monitoring Frequency GoalsTheDNRgroundwaterlevelmonitoringnetworkasitcurrentlyexistscollectsdatanominallyonamonthlybasis.Thenetwork’sdatabaseinfrastructureisnotoptimizedforstorageormanipulationoflargeamountsofdata.Ascurrentlystructured,itisdesignedtostoreonetoseveralmonthlywaterlevelmeasurementsperwell.Itisnowunderstoodthatmonthlymeasurementsarenotwhollyadequateforwaterlevelmonitoringinareaswheregroundwaterisextensivelyused.

Morefrequentmeasurementsofgroundwaterlevelsareappropriatewhereclimaticconditionsarevariable,wheretheaquiferssupplylargequantitiesofwater,whereshallowaquifersarepartofthemonitoringprogram,andwhererechargeratesarehigh(Figure20).

Figure21showsthedatarecordfromaDNRobservation

Figure20:Commonenvironmentalfactorsthatinfluencethechoiceoffrequencyofwater-levelmeasurementsinobservationwells(TaylorandAlley,2001).

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wellinanareaofagriculturalirrigationwherewaterlevelsfluctuatedramaticallyoverthesummerirrigationperiod.Thisdatarecordisshownasrecordedbyadataloggerathighorcontinuousfrequency,andasitwasrecordedthroughmonthlyhandreadingsasisthecurrentstandard

forDNRobservationwells.Hydrographsmadefromcontinuousdataallowthebestestimatesofmaximumandminimumwaterlevelsintheaquifersandcanrevealtheimmediateimpactofgroundwaterwithdrawals.

Figure21:Observationwellwaterlevelspresentedascontinuoustransducerdatarecordedbyadataloggerandasperiodic(monthly)handreadings.ThisisasurficialaquiferwellinPopeCounty.

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DATA STANDARDS AND DATA MANAGEMENT

Datastandardsanddatamanagementroutineshavebeendeterminedbyexpertpanelsinmorethanoneforum.ThisinformationisavailabletoMinnesota’sgroundwaterprofessionalsandwillbeadaptedtoMinnesota’sneedswithoutneedtorepeatthewholeeffort.AnexamplefromtheAdvisoryCommitteeonWaterInformation,SubcommitteeonGroundWater(2009)isintheAppendix.DocumentsthatwillbeadaptedforMinnesotaincludeguidancefor:

Standardpracticestoensurecomparability

Accessanddataexchange

Dataentryandqualitycontroltools,and

Analysistools

Software for Large Volume Data Management Continuous,i.e.highfrequency,monitoringisneededinthemetropolitanareatounderstandsystemresponse

tochange.Assessmentofgroundwaterrechargeisonlypossiblewherehigh-frequencymeasurementsofgroundwaterlevelsareavailable(LorenzandDelin,2007).Staffresourceswillquicklybeovermatchedunlessadequatesoftwareandnetworkinfrastructureareinplacetomanagethedata.

High Frequency Data CollectionThesoftwareandnetworkinfrastructureshouldbedesignedtobescalabletoaverylargenumberofmonitoringsitesthatcomprisestressedsubnetworks.Thequalityassuranceandqualitycontrolprocessesforindividualsiteswillbenefitfromusingdatafromadjacentsitestakenatequivalentfrequency,meaningthatideallyallsiteswouldbesampledatsimilarfrequencies.Thedataarchivingmethodswillstoredataatlowerorvariablefrequenciesifappropriate,andthedatadownloadmethodswillpermituserstorequestdataatanydesiredfrequency.Figure22isthedatamanagementanduseschematicasenvisionedintheNationalFramework.

Figure22:Awaterlevelmonitoringnetworkcansupportwaterqualitysubnetworksaspartofthemanagementsystem(AdvisoryCommitteeonWaterInformation,SubcommitteeonGroundwater,2009).

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RECOMMENDATIONS FOR IMPLEMENTATION

CooperativeimplementationoftheNationalFrameworkforGroundwaterMonitoringintheUnitedStateswillresultinanimprovedDNRgroundwaterlevelmonitoringnetworkthatwillformthebackboneoftheregionalgroundwaterlevelmonitoringnetworkforthemetropolitanarea.Thisbackbonenetworkwillalsoprovideopportunitiesforexpandedmonitoringofwaterchemistry.Minnesotawillcontinuetofocusonnetworkenhancementswhileapplyingtobeapilotsiteforthefirststagesofnationalnetworkdevelopment.

Newmonitoringlocationswillberecommendedbyamulti-agencycoordinationworkgroupandanynetworkimprovementswillfocusonmeetingbothwaterqualityandquantitymonitoringneeds.Existingandnewsubnetworks,towhichothercooperatorsalsocontribute,willmeetspecialmonitoringstudyneedsandwillprovidesomeoftheexistingwellsthatwillbeselectedforregionalmonitoring.Theanticipatedworkgroupworkplantaskscorrespondwithactionsrequiredofpartnersinthenationalmonitoringnetwork:

Task 1:EvaluatepotentialmonitoringpointsinthecurrentDNRgroundwaterlevelmonitoringnetworkforinclusioninthebackbonenetwork.TheMetropolitanCouncil’sregionalgroundwatermodeland/oraconceptualmodelofgroundwaterflowwillprovidecontextfortheseevaluations.

Task 2:JointeffortsofDNR,MDH,MDA,andMPCAwillensurewheneverpossiblethatlocationswillbeusefulforassessingwaterquality.

Task 3:Evaluatethechosenpointstoseeifnetworkcoveragemeetsmonitoringgoalsbothforareaswherepumpingstressesareanticipatedandinareasthatareunstressed.Selectwellsofeachtypefortrendmonitoringinastressedsubnetworkandforbackgroundmonitoringinanunstressedsubnetwork.

Task 4:Evaluatethegapsinboththestressedandunstressedsubnetworksandsearchforwellownersorwateruserswhomayhavetheabilitytomonitorwaterlevelsandprovidewaterleveldatameetingthestandardsofthebackbonenetwork.Provideappropriatetechnicalassistancetomakecooperationamutuallyvaluableundertaking.

Task 5:Prioritizeinstrumentationandmaintenanceneedsandbeginaprogramtoaddressproblemsandcarryoutenhancements.

Task 6:Workwithpartnerstostructureadataportaltoincludeanalysis,storage,andretrievalofqualitycontrolledandrevieweddata.Thisessentialtaskwillrequireongoingdedicationofsignificantresources.

Task 7:Calculatecosttomaintainthenetworkindefinitely.

Metropolitan Area Groundwater Resource IssuesAgroundwatermodelofthemajoraquifersintheseven-countyTwinCitiesareawasdevelopedfortheMetropolitanCouncil’swatersupplyplanningefforts.Themodelisbeingusedtopredictthepossibilityofcertainwatersupply-relatedproblemsinthefuture.Becausetheinitialmodelcalibrationareaincludedareassurroundingthesevencountymetropolitanareaandbecausethegeologicsettingisquitesimilar,theMetropolitanCouncil’sresultscanbeextended,inageneralsense,totheexpanded(elevencounty)metropolitanareaandusedtodefinethescopeofnewmonitoring.Figures23and24showareaswhereaquiferlevelsmaydeclinesignificantlyovertimeandareaswheresurfacewaterresourcesmaybeimpactedbygroundwaterwithdrawals.

Otherknowngroundwatermanagement-relatedissuesarealsobeingevaluated.InFigure25,forexample,locationsofgroundwaterdependentresourcesareshown.Inmanycasesastressonthegroundwatersystemcanresultinanadverseimpacttotherelatedsurfacewaterresource.Thebackbonenetworkwillassistmanagerswithdecisionsaimedtowardprotectionofvaluedecosystems.Figure26showsthecurrentunderstandingofseveralcategoriesofvulnerabilitytocontamination.

Current DNR Network CoverageThestatewideinventoryandstatusassessmentofwellsintheexistingDNRgroundwaterlevelmonitoringnetworkwasacceleratedsothattheresultsshownpreviouslyinTable1forthemetropolitanareawouldbeavailableforthisreport.Thecurrentnetworkincludes177activelymonitoredwells.Waterlevelmeasurementsaremademonthlyforatleast8monthsperyear.ThedistributionofactivewellsbyaquiferisshowninFigures27through30.

Assessing the Gaps in CoverageManywellsintheexistingDNRgroundwaterlevelmonitoringnetworkare‘Baseline’monitoringwells,intentionallylocatedwheretheywere(atleastinitially)notaffectedbyshort-termstresses.Monitoringoftheconditionofthemajoraquifersisapublicresponsibility,whilemonitoringofwellsintendedtotrackimpactsofpumpingisaresponsibilitytobesharedmoredirectlybytheusers.Onceabaselinemonitoringwellbeginstoshowpumpingsignaturesfromincreasedwateruse,anew,moredistantwellmustthenbeinstalledtomeetthebaselinemonitoringneed.

Tomeettheneedforaccuratelypredictingtheresponsetocurrentandfuturestresses,additionstothenetwork

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Figure23:AreaswheremunicipalpumpingmaycausesignificantaquiferdeclineaspredictedbytheMetroModel2(DataprovidedbytheMetropolitanCouncilMarch2009TwinCitiesMetropolitanAreaMasterWaterSupplyPlan,whichhasbeenprovisionallyapprovedbytheMetropolitanAreaWaterSupplyAdvisoryCommittee.Modelextentlimitedto7-CountyMetropolitanArea).

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Figure24:AreaswheremunicipalpumpingmayadverselyaffectsurfacewateraspredictedbytheMetroModel2(DataprovidedbytheMetropolitanCouncilMarch2009TwinCitiesMetropolitanAreaMasterWaterSupplyPlan,whichhasbeenprovisionallyapprovedbytheMetropolitanAreaWaterSupplyAdvisoryCommittee.Modelextentlimitedto7-CountyMetropolitanArea).

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Figure25:Areaswheremunicipalpumpingmayadverselyaffectgroundwaterdependentsurfacewaterfeatures.

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Figure26:Areaswhereaquifersmaybevulnerabletocontamination(Source:MDH.ArsenicandRadiumDatabasedon2008MDHAnnualPWSComplianceReport.Nitrate-NitrogenresultsrestrictedtoSherburne,WashingtonandWrightCountiesbasedonavailabledata).

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Figure27:Activesurficialaquiferobservationwelllocations.

36

Figure28:ActivePrairieduChien-Jordanobservationwelllocations.

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Figure29:ActiveFranconia-Ironton-Galesvilleobservationwelllocations.

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Figure30:ActiveMt.Simonobservationwelllocations.

39Figure31:SchematicofdataflowfromrawSCADAdatatoendusableproduct.

shouldalsobedesignedtomonitorstressesontheaquifersystemandmonitoringwellsshouldbelocatedinthefollowingtypesofhydrogeologicsettings:

Alongrivers(includingriverlevels).

Atperchedlakes(lakelevelandgroundwaterlevelbelow).

Nearhighcapacityproductionwells

Atthewatertableinrecharge/infiltrationareas.

Inornearsensitiveecosystems.

Acrossandwithinconfiningunits.

Attheedgesofconfiningunits(inburiedbedrockval-leys).

Along,oracross,orwithin,faultsorfaultzones.

Coordinationwithgoalsofallpartnersneededtoensurethenetworkgetsthemostpossibleinformationfromthefewestwells.Springandstreamflowmonitoringforassessmentofaquiferdischargefluxmustbeincludedinthisanalysis.Thedistributionofpermittedusersindicatesareasofongoingaquiferstress;populationgrowthforecastscanpredictfutureareasofaquiferstress.

Gaining Support and Acceptance of Monitoring PartnersAmonggroundwaterusersthereisarangeofmanagementapproachesandexpertise.Itwillbeimportanttoreachouttomajorwaterusers.Localgovernments,inparticular,canbeinvaluablepartnersinthecollectionofwaterlevelmonitoringdataandareinauniquepositiontobeabletoplanforsustainabilityoftheirowndrinkingwatersupplyonceadequatedataareavailable.Informationaboutaquifersystems,groundwaterlevelmonitoringandgroundwater-surfacewaterinteractionmustbereadilyavailabletolocaldecisionmakers.

Manywatersupplysystemsalreadymeasurewaterlevelinformationaspartofday-to-daywell-fieldmanagement,butdonotstoreoranalyzeit.Inthefuture,cooperatorsinthemetropolitanarea’sgroundwaterlevelmonitoringprogramwoulduploadittothedataportal(Figure30)soitcanbeaccessedandusedbyothergroundwatermanagers.Afterqualitycontrolandanalysis,theinformationwouldbeavailabletothecooperatoratanytime.Thegroundwaterlevelmonitoringprogrammustbepreparedtoprovidetechnicalassistancewithdevelopmentoflocalmonitoringplansincoordinationwithappropriationpermitrequirements.

WEB

SERVE DATA

waterlev

el DATA STORAGE

DATA PROCESSING

FINAL DATA

RAW DATA

WELL 6

WATER UTILITY OFFICE

RAW DATA

WATER

VALUE-ADDED PRODUCTS

40

FUNDING NEEDS

Publicinvestmentisrequiredatalllevelsofgovernment.Privateinvestmentisrequiredofusersoflargequantitiesofwater,wherethedefinitionof‘large’mayvarybasedonthehydrogeologicsetting,totaldemand,andotherresourcesorecosystemservicesatrisk.Monitoringnetworksgainvalueaslengthofrecordgrows.Dedicated,predictablefundinglevelswillallowthenetworktofunctionasintendedandprovidevaluecommensuratewiththeinvestment.

Network infrastructure needsWellconstruction,maintenanceandsealingwillbeongoingactivities.Newwellinstallationsforthebackbonenetworkmustmeetconstructionstandardsintendedtomaximizeusefullife.Locationsmustbechosenwiththeintentiontomaintainthewellnestindefinitely,meaningthatpermanenteasementsorpurchaseofsmallparcelswillbenecessary.

CurrentmaintenanceneedsforexistingDNRgroundwaterlevelmonitoringwellsincludesealingwellsthatdonotmeetcurrentstandards,areredundantorthatneedreplacementduetoage.

Technology needsTechnologythatallowsdatafromgroupingsofwells(nests)totransmitdataasonestationtogethercanaddefficiency.AWi-Fibasednetwork,forexample,isacosteffectivemeansofcollectingdata.OnehasbeenbuiltbytheSaintAnthonyFallsHydraulicLaboratoryfortheMinnehahaWatershedDistrict.Cellphonedatatransmissionispracticalinthemetropolitanarea.

Sophisticatedandveryefficientdatainputproceduresmustbeattheforefrontofdatabasedevelopmentforthedatacominginfrombackbonenetworkwells,fortime-seriesdatasubmittedbysubnetworks,andfordatasubmittedbywaterappropriationpermitholders.Qualityassuranceandqualitycontrolproceduresfordatacomingfromstressmonitoringwillrequiresignificantlymorerobustproceduresthanarecurrentlyinplace.

Anaccessibleinternetportalmustbedeveloped.Thebestcurrentmodelforthistypeofportalexistsforstreamgagingdata.Automatedproductsderivedfromnetworkdatacanbelinkedtolocalwebpagessothatmembersofthepubliccanviewanduseinformationfromspecificsubnetworksormonitoringlocationsasneeded.Thisinformationcanalsobelinkedtoavailablewaterqualityandwellinformation,furtherenhancingdataavailability.

Funding modelThisreportisrequiredtodevelopacost-basisfornetworkestablishment,operationandmaintenanceforan

indefinitenetworkexistenceandtoestimatethiscostincentspergallonofgroundwaterusedinthemetropolitanarea.

Water Use Estimate

Theaveragenumberofgallonsofwaterusedannuallyinthemetropolitanareaoverthepastfouryears(Figure2)hasgrowntoapproximately140billiongallons.

Network Cost Estimates

BestestimatesencompassingallnetworkexpensesareshowninTable1,repeatedonthefacingpage.Theassumptionsmadeindevelopingthecostsestimatesaregivenbelow.

Theexpectationisthatthemetropolitanarea’sreal-timebackbonemonitoringneedswouldlikelybemetbyabout60sites,someofwhichwillbelocatedinthemajoraquifersoutsidethemetropolitanarea.Atotalofapproximately180wellswillbemonitoredinthiswayandthedatawillbeavailablealmostimmediatelyfromthewebportal.

Allotherwellsinthebackbonewaterlevelmonitoringnetworkwithinthemetropolitanareashouldbemonitoredwithautomatedwaterlevelmeasuringdevices.Theconversionshouldcommenceimmediatelyandbecompletedin4years.

Thisassessmentisbasedontheexistenceofasubnetworkofadditional,permit-mandated,monitoringlocations.Theburdenofpermit-requiredmonitoringwillbesignificantlylighterwhendatainput,analysisandreportingareaccomplishedthroughthestate’snewcomprehensivegroundwaterlevelmonitoringdatabase.

Deferredwellmaintenancewillbecarriedoutduringthefirstfouryears.WellsinthecurrentDNRgroundwaterlevelmonitoringnetworkthatprovetobeunsuitableforthebackbonenetworkwillbesealedorturnedovertocooperators.Somewellswillhavetobereplacedifmaintenancedoesnotrestorefunction.Routinemaintenancewillbepartofnormaloperationsofthebackbonenetwork.

Toimproveunderstandingofstratigraphyandaquiferandaquitardcharacteristics,allnewlyconstructedwellswillbeloggedwithboreholegeophysicalmethods(gamma,caliper,temperature,fluidresistivityandflowmeterlogs).Whereinterpretationofaquifercharacteristicswouldbeaided,asubsetofexistingwellsshouldbelogged.

Waterchemistrysamplingofabasicsetofanalytesmustbecarriedoutatwellinstallationandrepeatedatsetintervalsasinformedbynetworkgoalsandananalysisoftheinitialwaterqualitydataset.

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Futurewellinstallationswillincludelandacquisitionorpermanenteasements.Thebackbonenetworkmustnotsufferfromabandonmentsforcedbylandownerdecisions.

Undercurrentfeestructures,monitoringwellfeesmustbepaidtoMDHorthelocalauthoritysothatnetworkwellsmaybesampled.

Databasedevelopmentandcreationofaninternetportaltootherdatasourceswhethertheinterfacefortechnicalusersisonacommercialplatformoronastate-developedplatform,shouldbeaccelerated,withcompletionwithinfouryears.Databasedevelopmentandcreationincludesdataentryviawebinterface,email,orupload;automaticdataprocessingandQA/QCroutines;dataanalysistools;web-baseddisplayandretrievalofdata;andtheabilitytoservethedatatocooperator’swebsitesinthecooperator’sdesiredformats.Ongoingsystemmaintenancewillberequired.

Advanceddataanalysisroutinestoincludederivationofaquifercharacteristicsfromtimeseriesdatawillbecreatedandaddedtothesuiteofavailabletools.

Cost in Cents per Gallon

Totalestimatedcostsforbuild-outofthenetworkoverfouryearstotal$8,861,150milliondollars.

$8,861,750.00 /4 years = $2,215,437.50 per year

$2,215,437.50 per year / 140 billion gallons per year= $0.00001582 per gallon =

0.0000001582 cents per gallon, or

$15.82 per million gallons.

Disclaimer:Therecommendationsinthisplanwillneedtobeadjustedinthefuturebecauseof

Constantlyevolvingmanagementneeds

Constantlyevolvingtechnology

Constantlyevolvinghuman-builtenvironment

Constantlyevolvingunderstandingoftheaquifersystem

Establishmentandmaintenanceofabackbonegroundwaterlevelmonitoringnetworkisthebestinsurancethatgroundwatermanagerswillhave,inlargepart,thedataneededtofacethedecisionsofthefuture,whatevertheymayturnouttobe.

Table1:CostsfortheCreation,Maintenance,andOperationofaGroundwaterLevelMonitoringNetworkforthe11-CountyMetropolitanArea.

Year 1 Year 2 Year 3 Year 4Total

DevelopmentSubsequent

Years

Total Wells in Backbone Network 80 175 270 380 380 380

Backbone Network Establishment: Well Drilling, Easements, Instrumentation, Operation and Maintenance 1,083,400$ 1,310,750$ 1,440,600$ 1,627,000$ 5,461,750$ 627,000$

Technical Support / Quality Control / Groundwater Analysis 350,000$ 350,000$ 350,000$ 350,000$ 1,400,000$ 105,000$

Data Management and Access through Web Portal 500,000$ 500,000$ 500,000$ 500,000$ 2,000,000$ 93,000$

$ 1,933,400 $ 2,160,750 $ 2,290,600 $ 2,477,000 $ 8,861,750 $ 825,000

Dollars per Million Gallons 13.81$ 15.43$ 16.36$ 17.69$ 15.82$ 5.89$

Cents per Gallon 0.001381 0.001543 0.001636 0.001769 0.001582 0.000589

Notes: All values 2009 dollarsNotes: All values 2009 dollars

By the end of the fourth year of network build-out, the backbone network will consist of 60 nests for which data are transmitted real time (approx. 3 wells per nest) and 200 monitoring wells with dataloggers

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BIBLIOGRAPHY

AdvisoryCommitteeonWaterInformation,SubcommitteeonGroundWater,2009,NationalFrameworkforGroundwaterMonitoringintheUnitedStateshttp://acwi.gov/sogw/pubs/tr/sogw_tr1_Framework_june_2009_Final.pdf

AmericanWaterResourcesAssociatione-newsletter,August2009,WhatWaterResourcesChallengesDoWeFaceintheNextDecade?

Delin,G.N.,andFalteisek,J.D.2007,GroundWaterRechargeinMinnesota.USGSFactSheet2007-3002.http://pubs.usgs.gov/fs/2007/3002/pdf/FS2007-3002_web.pdf

FreshwaterSociety,2009,WaterforLife–SustainabilityofGroundWater,http://www.freshwater.org/images/stories/PDFs/publications/Sustainability-of-Ground-Water.pdf

Lorenz,D.L.,andDelin,G.N.,2007,Aregressionmodeltoestimateregionalground-waterrechargeinMinnesota:GroundWater,v.45,no.2.

MinnesotaPollutionControlAgency,2009,MPCA’sambientgroundwatermonitoringstrategyproposalfortheCleanWaterLandandLegacyAmendment.http://www.pca.state.mn.us/publications/leg-09sy1-11.pdf

NationalWaterQualityMonitoringCouncil,2003,SeekingaCommonFrameworkforWaterQualityMonitoring.SpecialIssueofWaterResourcesImpactVol.5No5,http://acwi.gov/monitoring/pubs/0309impact.pdf

CouncilofCanadianAcademies,2009,TheSustainableManagementofGroundwaterinCanada.http://www.scienceadvice.ca/documents/(2009-05-11)GWReport.pdf

Taylor,CharlesJ.andWilliamM.Alley,2001,Ground-Water-LevelMonitoringandtheImportanceofLong-TermWater-LevelData,USGSCircular1217.http://pubs.usgs.gov/circ/circ1217/pdf/circ1217_final.pdf

Ward,RobertC.,1989,WaterQualityMonitoring–ASystemsApproachtoDesign.PresentationattheInternationalSymposiumontheDesignofWaterQualityInformationSystems,USEnvironmentalProtectionAgencyandColoradoStateUniversity.

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APPENDIX

TheGroundWaterLevelMonitoringWorkGroupwithinDNRWatershasbeguntheprocessofdraftingguidancedocumentsforthegroundwaterlevelmonitoringnetwork.Completeddraftsaddressthefollowingtopics:

NetworkGoalsandObjectives

PolicyandCriteriaforAcceptingExistingWellsintotheNetwork

PolicyandCriteriaforInstallingNewWellstoaddtotheNetwork

PolicyandCriteriaforRemovingWellsfromtheNetwork

PolicyandCriteriaforInstallationandUseofElectronicDataLoggingandTelemetryintheNetwork

PolicyandCriteriaforVibratingWireTransducerUseandInstallationinWellsoftheNetwork

FieldPracticesforGroundWaterDataCollection

Thedraftsweredevelopedtoservethemostimmediateoperationalneedsofthecurrentnetwork.Theintentionisthatallwillbecomecomponentsofafullydevelopedguidancedocument.

PresentedasexamplesbelowPolicy and Criteria for Accepting Existing Wells into the NetworkandField Practices for Ground Water Data Collection.

Policy and criteria for accepting existing wells into the NetworkThispolicyappliesto:

AcceptingexistingwellsfromotherentitiesintotheMinnesotaGroundWaterLevelMonitoring(GWLM)Network.OwnershipofthewellmayormaynotbetransferredtotheStateofMinnesota,DepartmentofNaturalResources,DivisionofWaters,dependingoncircumstances.

Background

Fromtimetotimeexistingwellsmaybecomeavailableforuseasmonitoringwells.Inmostcases,thewellisnolongerbeingusedbytheowner.Thereasonsthatawellisnolongerusedinclude:thecompletionofastudy,reuseofasite,orachangeoflandownership,amongothers.Ratherthansealthewell,andpossiblyincurconsiderableexpense,theowneroftheexistingwellmayapproachDNRWatersandproposethatthewellbecomepartoftheGWLMNetwork.TheactualownershipofthewellmayormaynotbetransferredtoDNRWaters.Potentialwellsforinclusioninthenetworkmayalsobeidentifiedin

otherways,suchassurveysofunusedorabandonedwellsbylocalgovernments.Historically,mostofthewellsinthecurrentnetworkwereaddedtothenetworkthroughformalorinformalaccessobtainedfromotherentities.InsomecasesDNRacceptedformalownershipofthewellfromanotherentity.

AddinganexistingwelltotheNetworkmaybeverybeneficialintermsofaddingvaluabledatatothenetworkwithouttheexpenseofactualinstallation.ExistingwellsthatareaddedtotheNetworkbyaccessagreementhaveownershipandfutureresponsibilityretainedbyanotherentity.However,iftheownershipofthewellistransferredtoDNR,thetransferbringswithitacommitmentbyDNRWaterstomaintainthesiteand,whennolongerneeded,tosealthewell.Potentialcoststosealawellcanbeconsiderable.

General Policy:

TheDivisionofWaterswilladdexistingwellstotheGWLMNetworktoimprovethequalityandquantityofgroundwaterdataandtoreducethecostofinstallingnewwells.

General Criteria:

AnexistingwellproposedtobeaddedtotheNetwork:

Mustfulfillamonitoringneed;

Shouldmonitoraknownaquiferorsystem;

Mustbeinconnectionwiththeaquifer;

Mustbeintendedforlong-termmeasurement;

MustmeetrequirementsoftheMinnesotaWellCode.

Technical Criteria

Theexistingnetworkshouldbereviewedtoidentifyaspecificneed.Forexample,thewellfillsagapthatex-istsinthenetworkorthewellcanreplaceanexistingnetworkwellthatisnolongerfunctioningproperlyandneedstobereplaced.

Theexistingwellshouldconnectwithanaquiferofsufficientextentandthicknesstohaveaneconomicorresourcevalueforasignificantarea.

Othergroundwaterlevelmonitoringnetworksshouldbereviewedsotheproposedwellisnotaduplicateofanexistingoperationalwell.Theproposedwellshouldalsosupportcomplementaryhydrologiccyclenetworkssuchasclimateandsurfacewater.

Wellsthatareproposedforownershiptransferto

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DNRWatersshouldbelessthan25yearsoldandlessthan6inchesindiameter.ProposedwellsmustmeettherequirementsoftheMinnesotaWellCodeatthetimeoftransfer.

ProposedwellsforinclusionintheNetworkshouldbeatleast2inchesindiametertoaccommodatemea-surementdevices.

GWLMNetworkwellsshouldnotbeusedforpump-ing.Iftheproposedwellisusedforpumping,theef-fectsofthepumpingshallbeconsideredpriortoac-ceptingthewellintotheNetwork.

Thewellmusthaveproperdocumentationincludingawelllogand/orotherconstructiondatathatad-equatelydescribesthephysicalsettingandconstruc-tionofthewell.

Geophysicalandvideologsshouldbeconductedonallproposedwellstoverifytheconditionofthewellandconfirmthegeologyoftheareainwhichthewellisinstalled.

Pumpingand/orslugtestsshouldbeconductedtodemonstratefunctionalityofthewell.

Theconditionandsafetyoftheproposedwellmustbefield-verified.Thefieldverificationstepshouldalsochecklocation,use,pumps,orotherequipmentinthewell.

AnywellthatisopentomultipleaquiferscannotbeacceptedintotheNetworkunlessprovisionshavebeenmadetoproperlyrefitthewellforsingleaquiferuse.

Administrative Criteria

Therecordofownershipofeachwellproposedforin-clusionintheNetworkshouldbeconfirmed.WhetherthewellisaddedtotheNetworkbyaccessagreementortransfer,anaccessagreementortransferagree-ment,respectively,willneedtobeconcludedwiththewellowner.

Iftheproposedwellfortransferisnotanactivelyusedwell,anypumpsorstructuresinthewellshouldberemovedpriortoacceptingthewellfortransferintotheGWLMNetwork.Thisworkshouldbecon-ductedbytheprevious/existingownerofthewellpriortotheDNRWatersusingthewellaspartoftheNetwork.

ForwellsthatareaddedtotheNetworkbyaccessagreement,anaccessarrangementshallbeapprovedbetweenthepropertyownerandtheDNRWaterstoallowlong-termaccesstothewelllocationformoni-toringandmaintenance(asdefinedintheAccessAgreement).

Existingwellsthatareproposedforadditiontothe

DNRWatersGWLMNetworkshallhaveidentifica-tiontagsandimpactprotectioninstalledasneededtomeetMinnesotaWellCodeRequirementspriortoac-ceptingthewellintotheNetwork.

IfawellisunsuitableforaddingtoGWLMNetwork,theinformationaboutthewellshouldbestoredforpossiblefuturereviewandreconsideration.

EachproposedadditiontotheNetworkshouldbecarefullyreviewedandareviewmemoandrecom-mendationprepared.Thereviewshouldbeconduct-edbytheGroundwaterMonitoringWellCoordinatorandshouldaddressthecriteria(asoutlinedabove)usedtodetermineifawellshouldbeacceptedintotheGWLMNetworkasanobservationwell.Therec-ommendationwillbesubmittedtotheGroundWaterandHydrogeologySupervisorforreviewandcon-currance.ThedocumentationshouldbekeptintheGWLMNetworkwellfileandintheremarkssectionoftheGWLMNetworkdatabase.

Field Practices for Ground Water Data CollectionThese draft field practices are based on ‘Field Practices for Ground-Water Data Collection’, June 2009, Advisory Committee on Water Information, Subcommittee on Ground Water and on standard practices established for DNR and MPCA hydrologists.

Qualitydatadependonhighqualityconsistentfielddatacollectionprocedures.Importantelementstoensuredataqualityinclude:

Trainingofallstaffwhoareinvolvedindatacollection

Pre-visitfieldsitereviewandpreparationprocedure

Standardlistingofdataelementsthatmustbere-corded

Standardproceduretoprepareforwaterlevelmea-surementsatthefieldsite

Water-levelcollectionanddatarecordingprocedures

Field-samplingproceduresmusttaketheseelementsintoaccountinordertoensurethat:

Waterlevelsarebeingtakenatthecorrectlocation,fromthecorrectwellatthatlocation,andatthepropertime

Water-leveldataarerecordedandtransmittedaccu-rately

Informationrecordedduringmeasurementscontainsalloftheinformationneededtonormalizeandcom-pareanalysisresults

Measuresaretakentoensuretheaccuracyofthere-sult

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Thisdocumentsetsmostoftheminimumstandardsforsuccessfulfieldworkforthebackbonenetwork.Elementsofthewater-levelmeasurementaspectsofsubnetworkdataacquisitionprogramsshouldalsobedefinedinawrittensetofproceduresspecifictothesubnetworkdatacollectiongoals.

Training

Trainingofstaffisnecessarypriortofieldcollectionofground-waterlevelstoensureconsistentdataquality.Thisdocumentandothergroundwaterlevelnetworkguidancedocumentscanserveasthefundamentalbasisforthattraining.Appropriatetrainingincludesformaltrainingclassesthroughuniversities,professionalassociations,orvendorsandhands-onfieldexperiencethroughmentoring,on-site(onthejob),andfollow-uptrainingtoensurethatdataarebeingcollectedconsistentlyandcorrectly.Exampletraininggoalsinclude:

FieldSafety

Howtoestablishwherethepropermeasuringpointis.

Howtomeasurewater-levelswithdifferenttypesofnetwork-standardequipment,includingelectricandsteeltapes.

Howtomeasurewaterlevelswithpressuretransduc-ersandhowtoensurethatthepressuretransducerreadingsareverifiedwithdirectmeasurements.

Howtomaintaindataloggerequipmentandtoensurethataccuratemeasurementsarerecordedatthecor-rectintervals.

Howtostoreanddecontaminatefieldequipment.

Howtorecordfielddataandtakeappropriatenotesaboutsiteconditions.

Howtotransferfielddataandnotestopermanentda-tabaseandfilearchive.

Pre-visit Field Site Review and Preparation Procedure

Preparationforwater-levelmeasurementsincludesthegatheringofequipmentandsupplies.Achecklistoftheequipmentandsuppliesneededforeachmeasurementtripwillhelpthemeasureravoiddelaysandpreventthecollectionofinvalidmeasurements.

Equipmentthatwillbeusedtocollectcontinuouswaterlevelsshouldbecalibratedandtestedbeforedeploymenttoensureaccuracy.

Decontaminationandcalibrationofsteelandelectrictapesshouldbeconductedasnearintimeaspracticaltofieldmeasurement.Arecordofdecontaminationand

calibrationshouldbemaintainedforallequipment.

Standarddatasheetsforrecordingwater-levelmeasurementswillincludeallappropriatedatafields(suchas:welluniquenumber,sitename,date,time,waterlevelbelowmeasurementpoint,landsurfacecorrection,elevationofmeasurementpoint,etc.

Arecommendedlistofequipmentandmaterialsformiscellaneouswater-levelmeasurementsfollows:asuitablemap(optionally,anaerialphotographandatownplat/lotnumbermap),compassorhandheldglobalpositioningsystem(GPS),siteformforrecordingsiteinformation,water-levelmeasurementform,steeltape(graduatedinfeet,tenths,andhundredthsoffeet)optionallywithanattachedweightmadeofbrass,steeloriron,asolidcakeofbluecarpenterschalk,cleanrags,anelectricwater-levelmeasurementtape,penandpencil,adjustablewrenches,allenwrenches,pipewrenches,hammer,socketset,orothertoolsneededforwellaccess,abottleofsodium-hypochloritefordisinfection,andlatex-freevinylgloves.

Copiesofdatasheetsfrompriorsitevisitsareveryusefulwhendeterminingtheapproximatedepthtowatertodeterminelengthofsteeltapetobechalked.

Minimum Data Elements

Eachwater-levelmeasurementsitehasinherentdataelementsthatneedtobeverifiedandrecorded,preferablypriortowater-levelmeasurements.Thepersonmakingthewater-levelmeasurementshouldchecktoensureminimumdataelementsareavailablepriortoconductingmeasurementstoensurethatitisaccurateanduptodatewheninthefield.Correctionsandupdatestotheinformationshouldbemadepriortomeasurement.

TheASTMhasarecommendedlistofminimumdataelementsforinclusioninaground-waterlevelnetworkasdoestheUSGS,USEPA,andotherregionalandStateagencies.

Onsite Preparation

Thefollowingactivitiesarecarriedoutinpreparationforawaterlevelmeasurement:

Siteverification.Thiscanbeaccomplishedinseveralwaysincludinghavingmadeapreviousvisittothesite,comparingthesitetoaknowngridreferenceus-ingGPSequipment,comparingphotographsofthelistedsitetotheactualsite,oridentifyingthesitebyaphysicallabelonthewellheadoridentifyingsign.

Equipmentdecontamination.Equipmentmustbede-contaminatedbetweenwater-levelcollectionstopre-ventcrosscontaminationbetweenwells.

Siteconditionnotations.Theseincludethedateandtimeofday,weatherconditions(rain,snow,etc.),measurement-pointcondition,damage,deterioration

46

andanyotherfactorsthatcouldaffecttheresultsofthecurrentwater-levelmeasurementorfuturemea-surements.

Siteaccess.Thismayincludeaccesstotheproperty(gateopening,etc.)andopeningthecaporshelterthatenclosesthewell.

Usesitereferencematerialstoverifythemeasuringpointforeachmeasurement.

Water-LevelMeasurements

Numeroustechnicalprocedureshavebeenwrittentodescribetheprocedurestousewhenmeasuringwaterlevels,eithermanuallyorwithrecordersdesignedtoautomaticallymeasurewaterlevelsonacontinuousbasis.ProceduresfromUSEPA,USGS,andASTM,amongothers,exist.Becausethesetechnicalproceduresdonotappreciablyvaryintermsofthequalityofdatathatwouldresult,thefollowingsectionsrefertothetechnicalproceduresalreadydocumentedbytheseorganizations.

Allmeasurementsshouldberecordedeitheronafieldcomputingdeviceoronnetworkstandardpaperforms.Ifelectronicrecordingofmeasurementsischosen,allinformationrequiredonthepaperformalsoshouldbeenterableelectronically.Electronicfilesshouldbedownloadedwhenreturningfromthefieldandarchivedasamethodforretainingoriginalfieldmeasurements.Fieldmeasurementsrecordedonpapershouldbeelectronicallyenteredintoavailabledatabasesshortlyafterreturningfromthefield.Paperformsshouldbescannedandarchivedappropriately.Nooriginaldocumentsaretobereturnedtothefield.

ManualWater-LevelMeasurements

Allmanualwater-levelmeasurementsshouldbedesignedtohaverepeatableandaccuratemethodsofdeterminingtheelevationofthewater-levelsurface.Manualwater-levelmeasurementscanbemadebyuseofseveralmethods;themostcommonarethegraduatedsteelorwettedtapemethodandtheelectric-tapemethod.

Themethodchosenatagivensitewilldependonsiteconditionsandwellconstruction.

AutomatedWater-LevelMeasurements

Automatedwater-levelmeasurementsaremadesothatacontinuous(ornear-continuous)recordofwaterlevelscanbemadewithminimalhumanintervention.Automated(continuousornear-continuous)water-levelmeasurementscanbemadewithpressuretransducersandothertechnologies.Regardlessofthemethodofmeasurement,careshouldbetakentoensurethattheentireexpectedrangeofwaterlevelscanbemeasuredwiththedeviceattheexpectedaccuracy.

Afterthewater-levelrecorderisplacedinawell,theresultingmeasurementsarecomparedtomanualwater-

levelmeasurementstocreateacalibratedrecordofwaterlevels.Documentationshouldbemaintainedtoensureaccuratemeasurements,includingdate/timeofcalibration;thetype,serialnumber,andrangeofmeasurementdevice;andwhatunitsarebeingmeasured.Afieldcopyofthenecessarycalibrationandequipmentinformationshouldbetakentothefieldeachvisit.

Minimum Data Standards

Thefollowingsectionoutlinesvariousstandardstowhichwater-levelmeasurementsshouldadhere,toensureconsistentdataquality.Varioustypesofwater-levelmeasurementscanbemadeandthestandardsvarywiththetypeofequipmentusedtomakethemeasurements.

ManualWater-LevelMeasurements

Severalmanualwater-levelmeasurementsshouldbemadeinshortsuccessiontoensurethemeasurementisaccuratetowithinatleast0.02ftbetweenconsecutivemeasurements.Forelectric-tapemeasurements,theUSGSrecommendsthatatleastthreemeasurementsbemade,withtwoconsecutivemeasurementswithin0.02ft.Somemethodsofmanualmeasurement(atflowingwells,forexample)willnothavethatlevelofrepeatability.Regardlessofthemethodofmeasurement,allmeasurementsshouldberecorded.Theaccuracyofthewater-levelmeasurements(basedontherepeatabilityofthemeasurements)shouldbedocumented.

AutomatedWater-LevelMeasurements

Theaccuracyofautomated(continuous)water-levelmeasurementsshouldbeatleast0.02ft.Instrumentdriftandfaultyinstrumentationcanaffecttheaccuracyofthedatacollected.

Thefrequencyatwhichthewater-levelrecordershouldbevisitedshouldbebasedonthestabilityofthetransducer,thestoragelimitationsoftherecordingdevice,andknowledgeoftheexpectedhydrographoftheaquifer.Fieldvisitsatintervalsof6-8weeksshouldbesufficientuntiltherequirementsoftheindividualsitearedetermined.Regardlessofthemeasurementdevice,measurementsshouldbemadeoftenenoughthattherecordingdevicesonsitewillnotrunoutofroominmemorytostoredataandsothattheaccuracyofthemeasurementsisnotcompromisedthroughexcessivedriftorrangeofwaterlevel.Alargeannualdrawdown/rechargecyclewouldnecessitateadditionalvisitstoallowresettingthetransducerfordifferentseasonsorduringclimaticextremes.Real-time(ornear-real-time)telemetrycanalsobeaddedtothewell;astablewelldisplayingreal-timedatamaybevisitedmuchlessfrequentlythanotherwells.

Instrumentdriftcorrections,calibrationcorrections,anddatumcorrectionsallcanaffecttheaccuracyofmeasurementsandshouldbeappliedafterdownloadingthedata.

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Data Handling and Management

Extremeimportancemustbeplacedondocumentationoffieldandofficeprocedurestoensurethatthequalityofthedataismaintained.Thissectioncoverssomespecificdatahandlingandmanagementprocedures.

ElectronicEntryofData

Thefirststepinprocessingwater-leveldataisentryofthemeasureddata(measuredorcomputedvaluesassociatedwithaspecificinstantaneousdateandtime),fielddata,andrelatedinformationintoanelectronicdatabaseand/orprocessingsystem.

VerificationandEditingofData

Datamustbecheckedcarefullyandverifiedagainstfieldnotesorrecordsbeforebeingusedinfurtheranalysis.Suspiciousvaluesmayrequireinvestigation.Individualvaluesthatmightbeincorrectarecomparedtofieldmeasurementsortoknownextremesofrecord.Priortoediting,originalunitvaluesshouldbearchived;acopyoftheoriginaldatafileshouldbeedited,andthiscopyshouldalsobearchiveduponcompletionofediting.Variousissuescanariseinwaterleveldatasets,includingerrorswithtimesanddatesandinstrumentdriftordatumerrors.CurrentproceduresinplaceforentryofdataintothejointMPCA/DNRHydstradatasystemwillbedrawnuponforguidance.

Field-measurementdataincludesdiscretewater-levelmeasurements,well-constructiondata,andmiscellaneousfieldnotes.Field-measurementandrelateddatausuallyareenteredintotheelectronicsystemintheoffice,althoughsomedatacanbeenteredonportablefieldcomputers.Variouscomputationsandcomparisonsshouldbemadetoensureaccuracyofthedataandconsistencyoftheinformation

Arithmeticerrors,transcriptionerrors,andlogicerrors(suchasdepthofwelllessthandepthtowater),shouldallbecheckedandcorrectedbeforefinalentryintothedatabase.Alldatashouldbeenteredintothedatabasewiththesamesignificantdigitsasrecordedinthefield.Calculatedvaluesshouldberoundedtothesignificantdigitsrecordedinthefieldnotes.Measuringpointelevationsshouldbeapermanentdatummaintainedasaccuratelyaspossiblethroughoutthelifetimeoftheobservationwell.Surveyingorlevelingshouldbeperformedperiodicallytoensurethatcorrectionscanbemadetoadjustformovementofthedatum.

Originalpaperrecordsshouldnotbemodified,deletedorerased,orreturnedtothefieldbecausethisincreasesthechancetheywillgetdamagedorlost.Scanningandarchivingofnotesrecordedonpapernotesshouldbedonesothatalleditingoferrors,instrumentortimedriftcorrections,andsuchcanberecreatedifnecessary.

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