ATTACHMENT 1. SECTION 4 CENTRAL VALLEY SALT & NITRATE MANAGEMENT STRATEGY
Final SNMP for Central Valley Water Board Consideration: December 2016
Section 4
Central Valley Salt and Nitrate Management
Strategy
ElevatednitrateconcentrationsandsaltaccumulationintheCentralValleyposesignificantwaterqualitymanagementchallenges,inparticularinthegroundwaterunderlyingtheCentralValleyfloor.Theseconditionshavebeenevidentsincethe1970sandcontinuetoworsen(Johnsonetal.2012).Toreversethistrend,theCentralValleySNMPrecommendsasaltandnitratemanagementstrategythatincludesregulatoryrequirementsfortheCentralValleyRegion.BasedonthefindingsinSection3andthosedescribedbelow,thissectiondescribesanapproachtheCentralValleyWaterBoardcouldusetomanagesaltandnitrateintheCentralValleytomeetthisSNMP’smanagementgoals,wherereasonableandfeasible.
4.1 Salt & Nitrate Management Plan Framework ThefoundationforimplementationoftheCentralValleySNMPistheCentralValleyBasinPlanswhichestablishtheBoard’sexistingregulatoryauthoritytomanagesaltandnitrateintheregion.However,theexistingregulatoryframeworkintheseBasinPlanscurrentlylimitstheCentralValleyWaterBoard’sabilitytoconsiderinnovativesaltornitratemanagementstrategies,includingstrategiesconsistentwiththeintentandpurposeoftheRecycledWaterPolicyandgoalsofCV‐SALTS. Toaddresstheseregulatorylimitations,CV‐SALTSdevelopedrecommendationsformodificationsorclarificationstotheBasinPlanstofacilitateimplementationofinnovativesaltandnitratemanagementstrategiestoimprovewaterquality.Section4.2.2belowsummarizestheserecommendations.AttachmentAincorporatespolicy,strategy,andguidancedocumentsthatprovidetheregulatoryandtechnicalbasisforeachoftheserecommendations.TheCentralValleyWaterBoardmayproposeamendmentstotheBasinPlanstoincorporatetheserecommendationsintotheBasinPlans.Combined,theSNMPandtherecommendedpolicieswillestablisharevisedregulatoryframeworkthatwillprovidetheflexibilitynecessarytomakesaltandnitratemanagementdecisionsattheappropriatetemporal,geographicand/ormanagementzonescales.1
TheremainderofthissectiondescribestheoverallSNMPframeworkincludingthemanagementgoalsandprioritiesforthisSNMPandanoverviewofthegeneralapproachproposedtomanagesaltandnitratethroughouttheCentralValley.ThisSNMPframeworkisbasedonthefindingsoftechnicalstudiesthathavecharacterizedtheextentofsaltandnitrateconcernsintheCentralValleyandthetechnicalfeasibilitytomanagesaltandnitrateinamannerthatmeetstheSNMP’smanagementgoals.Ultimately,implementationofthisSNMPwillbeaniterativeandadaptiveprocessthatwillinvolveperiodicreviewandreassessmentsothatwhathasbeenlearnedby
1CV‐SALTSStrategyandFramework.http://www.cvsalinity.org/index.php/docs/committee‐document/executive‐committee‐docs/1411‐cv‐salts‐program‐work‐plan‐v‐8‐approved‐3912pdf/file.htmll
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Section 4 Central Valley Salt and Nitrate Management Strategy doingcanbeincorporatedintofuturerevisedSNMPs.WhereanysuchchangestotheSNMPrequireadditionalBasinPlanamendments,thesewillbeaddressedinatimelymanner.
4.1.1 Management Goals and Priorities InordertoachievedesiredoutcomesforthemanagementofsaltandnitratewithintheCentralValley,thisSNMPmustnotonlyaddresstherequirementsoftheRecycledWaterPolicy,butalsoaddresslegacyandongoingsaltandnitrateaccumulationissuesinamannerthatleadstoenvironmentalandeconomicsustainability.Todoso,implementationoftheCentralValleySNMPisbuiltonthefollowingthreemanagementgoals:
Goal 1: Ensure a Safe Drinking Water Supply
ThemostimportantmanagementgoalfortheCentralValleyRegionistoensurethatasafe,reliabledrinkingwatersupplyisavailabletoallresidentsoftheregion.ThisgoaladdressesthefindingsofthestatelegislatureapprovedAssemblyBill685,whichamendedtheCaliforniaWaterCodetodeclarethat,“…everyhumanbeinghastherighttosafe,clean,affordableandaccessiblewateradequateforhumanconsumption,cookingandsanitarypurposes.”2AccesstosafedrinkingwaterisespeciallycriticalinpartsoftheCentralValleywhereseveralindependentstudieshavereportedthatnitrateconcentrationsexceedtheestablishedmaximumcontaminantlevel(MCL)atnumerouswelllocationsthroughouttheCentralValley(seee.g.,Harteretal.2012;StateWaterBoard2013).Moreover,theStateWaterBoardreportedthat90publicwatersupplysystemsreportedviolationsoftheMCLfornitratein2012(seeTable4.13,StateWaterBoard2015).Theneedtoensureasafe,reliabledrinkingwatersupplyisthehighestpriorityforthemanagementofnitrateunderthisSNMPandshallbeimplementedasquicklyaspossibleinallareasintheCentralValleyRegion.
Goal 2: Achieve Balanced Salt and Nitrate Loadings
Goal2seekstoestablishabalanceofthemassofsaltandnitrateingroundwaterunderlyingeachpermittedormanagedarea,wherereasonableandfeasible.Withregardstosalt,balanceisdefinedasachievingastatewhereinputsofsalt(saltfluxin)intoamanagedareaareequaltooutputs(saltfluxout)fromthesamearea.Similarly,nitratebalancemeansabalanceofnitratefluxinandnitratefluxoutofthepermittedmanagedarea.Thenitratemassbalancewillneedtoaccountfornitratetakenupbycropsandlossesofnitratefromthenitrogencycleinsoil,includingdenitrificationintherootzonebysoilmicrobialactivityandvolatilizationtotheatmosphere.
Goal 3: Implement Managed Aquifer Restoration Program
Thisgoalseeks,wherereasonableandfeasible,torestoresaltandnitratelevelswithingroundwaterbasinsandsubbasinsorlocallymanagedareastoconcentrationsthatcomplywiththeapplicablewaterqualityobjectivesestablishedforeachconstituent.AsdemonstratedinthetechnicalworkusedtosupportthisSNMP(seeSection4.2.5),thechallengeassociatedwithsimplyachievingapplicablesaltandnitrateobjectivesinalreadyimpactedwatersissignificant.Accordingly,SNMPimplementationnotonlyfocusesonrestoringthebeneficialusewhere
2AssemblyBillNo.685added§106.3totheCaliforniaWaterCode.SignedbyGov.BrownonSeptember25,2012.
Commented [A1]: We agree and appreciate this important goal of the SNMP. However, important aspects of a safe, reliable drinking water supply include water that is aesthetically pleasing and at a reasonable cost. We are concerned that the proposed revisions to the secondary MCLs in Table 64449‐A will degrade source water quality and result in either reduced aesthetics of the treated water supply or increased water treatment and residual management costs. The implications of the SMCL guidance need to be included in the evaluation of this goal.
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Section 4 Central Valley Salt and Nitrate Management Strategy reasonableandfeasible,butalsoseekstominimizeorpreventfurtherdegradationofgroundwatersthatarecurrentlymeetingwaterqualityobjectivestoavoidfutureimpairment.
4.1.2 SNMP Overview ThisSNMPestablishestheminimumordefaultrequirementsforthemanagementofsaltandnitrateintheCentralValleyRegion.TheserequirementsaredescribedinSections4.3.2(nitrate)and4.3.3(salt)below,andwillbeimplementedthroughWDRs(individualorunderaGeneralOrder),ConditionalWaivers,orNationalPollutantDischargeEliminationSystem(NPDES)permits,asapplicable.SNMPimplementationwillbephasedacrosstheCentralValleyRegiontoallowresourcestobeallocatedtothemostsignificantwaterqualityprioritiesfirst.
Forgroundwater,thisSNMPsetsdefaultrequirementsforcomplianceapplicabletoalldischarges,basedonexistingambientwaterqualityconditionsandestimatedavailableassimilativecapacity(seeSection3.3),butallowsdischargerstodevelopdataindependentlyfortheareaundertheinfluenceoftheirdischarge(seeSection4.3.4).DevelopmentofalternativedatamaybeappropriatewhereadischargerorgroupofdischargersfindsthatthedefaultrequirementsofthisSNMParenotapplicabletothelocalareainfluencedbytheirdischargeanddataneedtobetailoredtothelocalareatobemorerepresentativeofexistingconditionswherethedischarge(s)occurandhaveinfluence.
Section4.3.2belowdescribesthenitratemanagementrequirementsunderthisSNMP.WhereagroupofdischargersdesiretoworkcollaborativelywithinadelineatedareatocomplywiththisSNMP'snitratemanagementrequirements,thesedischargersareencouragedtoestablishamanagementzoneinaccordancewiththeGroundwaterManagementZonePolicy(SeeSection4.2.2.1andAttachmentA‐1).Whereamanagementzoneisestablished,multipleWDRsorConditionalWaiversmayexistandbeaffectedbythenitratemanagementrequirementsestablishedforthemanagementzone.EachindividualdischargerwithinthemanagementzonestillmustcomplywiththerelevantWDRorConditionalWaiverthatauthorizestheirrespectivedischarge,buttheirrespectivepermitwillincludetherelevantnitratemanagementrequirementsestablishedforthemanagementzone.ForanindividualdischargerorathirdpartygroupsubjecttoaGeneralOrderthatchoosestonotparticipateinamanagementzone,orwhereamanagementzonedoesnotexist,amoretraditionalpermittingapproach(withsomemodifications)willberequiredtomeetthisSNMP’snitratemanagementrequirements.
Section4.3.3belowdescribesthesaltmanagementrequirementsunderthisSNMP.DischargerswillbestronglyencouragedtoparticipateinthisSNMP’sphasedSalinityManagementStrategy(seeAttachmentA‐3),unlessthedischarger(s)optoutandtheirdischarge(s)meetspecificoptoutrequirements.ImplementationofSalinityManagementStrategywillprovidethebasisfortheestablishmentoffuturesaltmanagementrequirementstobeimplementedthroughWDRs/ConditionalWaiversandNPDESpermits.
4.2 SNMP Development Process DevelopmentofthisSNMPhasbeenamulti‐yearprocessinvolvingfrequentstakeholdermeetings,developmentofrecommendedmodificationstotheBasinPlans,andcompletionoftechnicalstudiestoprovidethefoundationfortheSNMP’srecommendations(seeAttachmentD‐
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Section 4 Central Valley Salt and Nitrate Management Strategy 2).Belowisasummaryofthekeyactivities,documents,andstudiesthatprovidethebasisforthisSNMP.
4.2.1 CV‐SALTS ThisSNMPistheproductoftheeffortsofCV‐SALTS,abroadcoalitionofrepresentativesfromagriculture,cities,industry,stateandfederalregulatoryagencies,andthepublic(includingEnvironmentalJusticeadvocatesonbehalfofdisadvantagedcommunitiesandpopulations).Initiatedin2006,CV‐SALTSdevelopedthisenvironmentallyandeconomicallysustainableplanforthemanagementofsaltandnitrateconsistentwiththeState’sRecycledWaterPolicyandaddressinglong‐termsaltandnitrateconcernsintheCentralValleyRegion.CV‐SALTSincludessupportfromtheCentralValleySalinityCoalition(CVSC),anon‐profitorganizationandformedinJuly2008toorganize,facilitateandfundeffortsneededfortheefficientmanagementofsalinityandnitratesintheCentralValley.
ThedevelopmentofthisSNMPoccurredoveranumberofyearsprimarilythroughtheoversightoftheCV‐SALTSExecutiveCommitteeandtechnicalsupportfromaTAC.TheExecutiveCommitteeismadeupof30members:6committeechairs,6representingnon‐governmentalorganizations,federalandstateagenciesand18membersoftheCVSC.TheExecutiveCommitteeprovidesoversightofallothercommitteesinCV‐SALTSandapprovesallfinaldecisionsandactions,includingthecontentofthisSNMP.Formanyyears,thecommitteemettwicemonthly:(a)face‐to‐facepublicpolicymeetingsinSacramento,Californiawherethesaltandnitratepolicyandmanagement‐relatedelementsofthisSNMPweredevelopedcollaboratively3;and(b)publicadministrativemeetingteleconferencestodiscussprocess‐relateditemsincludingmanagementofcontracts,progressofongoingsupportingtechnicalwork,andcommitteeprocedures.AllExecutiveCommitteemeetingshavebeenheldincompliancewiththeBagley‐KeeneOpenMeetingAct;meetingagendas,notesandsupportingmaterialsareavailableatwww.cvsalinity.org.
TheCV‐SALTSTACisanall‐volunteercommitteecomprisedofstakeholderswithvaryinginterestsandexpertiseinthetechnicalissuesassociatedwithsaltandnitratemanagementintheCentralValley.TheTACmeetsperiodicallyviateleconferenceorface‐to‐facemeetingsintheSacramentoareatoprovideoversightandinputonspecificCV‐SALTStechnicalissues.AllTACmeetingsareheldincompliancewiththeBagley‐KeeneOpenMeetingAct;meetingagendas,notesandsupportingmaterialsareavailableatwww.cvsalinity.org.
4.2.2 Recommended Clarifications, Policies and New Regulatory Tools DevelopmentofthisSNMPincludedanevaluationofexistingpoliciesandrequirementsintheregion’sBasinPlansandledtothedevelopmentofrecommendedclarifications,policiesandnewregulatorytools(orstrategies)tofacilitateSNMPimplementation.TheserecommendationsaredesignedtofacilitateimplementationofthisSNMPandeffortstoachievethesaltandnitratemanagementgoals.Forthemostpart,theserecommendationsarenotself‐implementingandwillrequireadoptionofBasinPlanamendments.ThesectionsbelowprovideasummaryofCV‐SALTS
3Notably,whilethepoliciesweredevelopedwithsignificantdiscussionandcollaborationbyallinvolved,thereisnotunanimousconsensuswithrespecttosupportforallofthepoliciesbyallCV‐SALTSExecutiveCommitteeparticipants.AttachmentD‐3providesadditionalinformation.
Commented [A2]: Please see specific mark‐up comments below.
Commented [A3]: The inclusion of the SMCLs in Table 64449‐A does not affect implementation of salt or nitrate policies.
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Section 4 Central Valley Salt and Nitrate Management Strategy recommendations.4Theinformationbelowissupportedbytheciteddetailedpolicy,strategy,orguidancedocumentsprovidedinAttachmentA.
4.2.2.1 Groundwater Management Areas
Default Groundwater Management Areas
TheintentofRecycledWaterPolicySection6.b.(1)(a)isforeverygroundwaterbasin/subbasinintheCentralValleytohaveaconsistentsaltandnitratemanagementplan.DWRBulletin118defines,delineates,anddescribesthegroundwaterbasinsandsubbasinsintheCentralValleyRegion(DWR2003).5Thesebasins/subbasinswillserveasdefaultmanagementareasunlessagroupofdischargerselectstoestablishamanagementzone,whichmayestablishanalternativeareaforthemanagementofnitrateingroundwater(seediscussionbelowandSection4.3.2).HighresolutionmappingwasdevelopedfortheCentralValleyRegion,whichmaybeusedtosupportthedevelopmentofappropriatemanagementarea.
TheBasinPlansfortheCentralValleyincluderequirementsfortheprotectionofgroundwaterqualitythroughtheestablishmentofwaterqualityobjectivesandprogramsofimplementationtoachievethewaterqualityobjectives.Currently,theTLBBasinPlanidentifiesgroundwaterbasinsandsubbasinsinTableII‐2that,forthemostpart,matchthoseshowninBulletin118.6However,whenDWRBulletin118waslastupdated(DWR2003),DWRdeletedseveralofthesubbasins.TLBBasinPlanTableII‐2hasnotbeensimilarlyrevisedtoreflectDWR'schanges.7TheSRSJBBasinPlandoesnotcurrentlyidentifyorenumeratespecificgroundwaterbasinsorsubbasins,asidentifiedbyDWR’sBulletin118.
DWRperiodicallyrevisestheboundariesofgroundwaterbasins/subbasins.Therefore,eveniftheBasinPlansareupdatedtoincorporatetheexisting,publisheddelineation,thisinformationcouldbecomeoutdatedrequiringadditionalBasinPlanamendments.Giventhatchangestogroundwaterbasin/subbasindelineationswilloccurinthefuture,itmaynotbeappropriatetodirectlyincorporateDWR’sgroundwaterbasin/subbasindesignationsintotheBasinPlans.Instead,aspartoftheplannedupdatetotheBasinPlanstoincorporatetheSNMP,theCentralValleyWaterBoardwillconsiderthebestapproachforreferencingDWR‐delineatedgroundwaterbasins/subbasinsintheBasinPlanstoallowforfuturechanges.
Groundwater Management Zone Policy (Attachment A‐1)
TheSNMPrecommendsestablishmentofaprogrammaticapproachtonitratemanagementintheCentralValleyRegion.Aspartoftheprogrammaticapproach,theSNMPrecommendsthattheBasinPlansbeamendedtoallowandencouragemanagementofnitratethroughthe
4ThisSNMPwasdevelopedthroughaprocessthatprovidedseveralopportunitiesforcommentstobesubmittedbyExecutivePolicyCommitteemembers.Attemptsweremadetoaddressallcommentsreceived,butdisagreementsremainwithrespecttosomekeyaspectsoftheSNMPrecommendedpolicies.AttachmentD‐3summarizeskeyalternativeproposalsubmitted.
5TheTLBBasinPlanfurtherdividesoneofthesegroundwaterbasinsintothreehydrographicunits,seeTLBBasinPlanFigureIII‐1.6TLBBasinPlan,pagesII‐5&II‐6.7Thefollowing“SatelliteBasins”listedintheTLBBasinPlanwereremovedasgroundwatersubbasinsintheDWR2013update:SquawValley,CedarGroveArea,ThreeRiversArea,SpringvilleArea,TempletonMountainArea,MonacheMeadowsArea,SecatorCanyonValley,RockhouseMeadowValley,InnsValley(LinnsValleyinTLBBasinPlan),BearValley
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Section 4 Central Valley Salt and Nitrate Management Strategy establishmentofmanagementzones.Ingeneral,amanagementzonewouldconsistofmultipledischargersworkingcollectivelytoensurefirstsafedrinkingwater,thentomanagenitratestocreateabalancewithinthedefinedmanagementarea(wherereasonableandfeasible),andultimatelytodevelopandimplementalong‐termplanforrestorationofgroundwater(wherereasonableandfeasible)tomeetapplicablewaterqualityobjectives.
AlthoughtheBasinPlansdonotcurrentlypreventthemanagementofnitratesthroughthecreationofmanagementzones,theSNMPrecommendstheinclusionofaGroundwaterManagementZonePolicywithintheBasinPlanssothatwhatconstitutesapropermanagementzoneisclearlydefinedandtoensurethatcriteriaforapprovalofamanagementzonebytheCentralValleyWaterBoardareproperlyestablishedinregulation.ThejustificationforauthorizingtheestablishmentofmanagementzonesisexpressedinvariousstatewideandCentralValleyWaterBoardpolicies(seediscussioninAttachmentA‐1).Withrespecttosalinity,managementzonesmaybeappropriateinthefuturebutarenotpracticalatthistime.Rather,salinityisbeingaddressedindependentlyfromnitratesintheSalinityManagementStrategy(seeSection4.3.3belowandAttachmentA‐3).
4.2.2.2 Permitting and Management Strategies Nitrate Permitting Strategy (Attachment A‐2)
TheSNMPprovidesthebasisforthemanagementofnitrateintheCentralValley.FordischargersregulatedbytheCentralValleyWaterBoard,thesemanagementeffortsmustultimatelybeimplementedindischargepermitsissuedtodischargers.WDRsandConditionalWaiversmustensurethatthereceivingwaterwillmeetthewaterqualityobjective,andthatdischargesdonotcauseorcontributetoanexceedanceofthewaterqualityobjective.InsomeareasoftheCentralValley,andforsometypesofdischargers,thetraditionalpermittingapproachfornitratesmaynotbefeasible,reasonableorpracticable.Accordingly,CV‐SALTSdevelopedanSNMPNitratePermittingStrategythatsetsforthrecommendationswithrespecttopermittingnitratedischargesinWDRsandConditionalWaiversunderthetraditionalpermittingapproachaswellasprovidingforalternativepermittingapproaches.AttachmentA‐2providesadetaileddiscussionoftheNitratePermittingStrategythatissummarizedinSection4.3.2below.
Salinity Management Strategy (Attachment A‐3)
TheSNMPanditsassociatedtechnicaldocumentsproposelong‐termsolutionsforaddressingsalinity.Forexample,theStrategicSaltAccumulationLandandTransportationStudy(SSALTS)identifiedandevaluatedpotentialsaltmanagementstrategies(CDMSmith2013,2014,and2016b).Thestudy’sfindingsshowedthatcurrentsalinitymanagementactivitiesmayonlyaddressabout15%oftheannualsaltload;long‐termsolutions,includingdevelopmentofregionalde‐salters,aregulatedbrineline,orotherprojectsthatwouldallowcontainmentorremovalofsalt,areneededtoaddresstheother85%.Theselong‐termmanagementstrategieswillrequiresignificantstateandfederalfundingtoimplement.Inthemeantime,theCentralValleyWaterBoardmustimplementtheBasinPlansthroughtheadoptionofWDRs/ConditionalWaiversthatconsiderthebeneficialusestobeprotectedandthewaterqualityobjectivesassociatedwiththosebeneficialuses.
Becausethesolutionsforaddressingsalinityarelong‐terminnature,theCentralValleyWaterBoardneedsbeabletoconsiderinnovativesaltmanagementstrategiesforboththeshortterm
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Section 4 Central Valley Salt and Nitrate Management Strategy andthelongtermthatmovetheregiontowardsaltbalanceandrestorationofimpactedareas,wherereasonableandfeasible.ThisincludesneedingadditionalregulatoryflexibilitywithrespecttotheissuanceofWDRs/ConditionalWaiverswithsalinity‐relatedrequirements.SomeofthisflexibilitycanbeobtainedthroughtheimplementationofrecommendedCV‐SALTSpoliciesandguidanceasdescribedbelowinSection4.2.2.3.Inaddition,tosupplementthesepoliciesorguidance,CV‐SALTShasestablishedaSalinityManagementStrategythatrecommendsaprocessformovingforwardwithaphasedlong‐termsalinitymanagementprogram.Thisprogramincludes(1)arecommendationforremovalofexistingsalinity‐relatedlimitationsintheTLBBasinPlanImplementationChapter;and(2)adoptionofaproposedInterimSalinityPermittingApproachforsalinitydischargesduringimplementationofthefirstphaseoftheSalinityManagementStrategy.AttachmentA‐3providesadetaileddiscussionoftheSalinityManagementStrategythatissummarizedinSection4.3.3below.
4.2.2.3 Policies and Guidance
Exceptions Policy (Attachment A‐4)
AttachmentA‐4providesthebasisforrecommendationtoamendtheBasinPlanstorevisetheexistingCentralValleySalinityExceptionsProgram.Thisprogramwaspreviouslyestablishedforthefollowingreasons:Whereadischargeisnotbetterthantheapplicablewaterqualityobjectiveandnoassimilativecapacityisavailable,theBasinPlansrequiredtheCentralValleyWaterBoardtoprohibitthedischarge,adoptatimescheduleintheorderthatallowsthedischargertocomeintocompliancewithneededWDRprovisions,orrevisetheapplicablewaterqualitystandard.Becausethesetraditionalremedieswerenotalwaysappropriateforsalt,theBoardadoptedanExceptionsPolicyintheBasinPlansthatincludesaSalinityExceptionProgramtobeineffectduringtheCV‐SALTSprocess.
TheexistingExceptionsPolicyprohibitstheCentralValleyWaterBoardfromauthorizingnewexceptionsorreauthorizingpreviouslyapprovedexceptionsrelatedtosalinityafterJune30,2019.Inaddition,theSalinityExceptionProgramappliesonlytoTDS/EC,chloride,sulfateandsodiumanddoesnotidentifyguidelinesforanexceptiontobeauthorizedfornitratewaterqualityobjectives.ThisSNMPrecommendsrevisingtheexistingExceptionsPolicybyamendingtheBasinPlansinthefollowingmanner:
AddnitratetothelistofchemicalconstituentsforwhichtheCentralValleyWaterBoardmayauthorizeanexception;
Expand/reviseconditionsorauthorizationofanexceptiontoreflectthegoalsoftheSNMP;
Removetheexistingsunsetprovisionthatprohibitsthegrantingofsalinityexceptions
beyondJune30,2019;and Deletethecurrentprovisionlimitingthetermofanexceptiontonomorethan10yearsand
addanewprovisionstatingthatwhenauthorizinganexception,theCentralValleyWaterBoardshalladoptatermfortheexception.Termsforexceptionsshallgenerallynotexceed10years,however,theCentralValleyWaterBoardshallhavethediscretiontoadoptanexceptionforlongerthan10yearsiftheapplicant(s)candemonstratethatitisnecessarytofurtherthemanagementgoalsoftheSNMP.RetaintheCentralValleyWaterBoard’s
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Section 4 Central Valley Salt and Nitrate Management Strategy
authoritytoreauthorize(renew)anexceptionforoneormoreadditionalterms,thelengthofwhichshallbedeterminedbytheCentralValleyWaterBoard.
Salinity Management to Provide Reasonable Protection of AGR Beneficial Uses in Groundwater (AGR Policy) (Attachment A‐5)
SignificantchallengesexistinestablishingpermitlimitstoprotecttheAGRbeneficialuse.AttachmentA‐5providesadetaileddiscussionoftheissues;followingisasummary.TheAGRbeneficialusewasdesignedtoprotectbothcropirrigationandlivestockwateringandhasbeendesignatedinthemajorityofsurfacewatersandgroundwaterthroughouttheCentralValley.AlthoughthewaterqualityobjectivestoprotecttheAGRbeneficialusearenarrative,currentlynoguidanceexistsonhowtointerpretthenarrativeobjectiveinamannerthataccountsforlocalandregionaldifferences.Asadefault,aconservativeapproachensuresprotectionofthemostsensitivecropinalllocationsatalltimes(e.g.,EC<700µS/cm)hasbeenutilized,eventhoughindividualcropandlivestocksensitivitytosalinityvarieswidelyandpotentialimpactscanbemitigatedthroughmanagementactivities.8
TheapplicationofthisconservativeapproachtoprotectingtheAGRbeneficialusecreatesanumberofissuesforresolution:
Impactsontheabilityofdischargerstomanage/maximizereuseofdrainagewateron
progressivelymoresalttolerantcrops. Manysubbasinsandlocalizedareashaveelevatedbackgroundsaltconcentrationsthatare
higherthan700µS/cm. Duetoconsumptiveuse,veryhighqualityirrigationwaterwouldbeneededtoensure700
µS/cmindrainagebelowtherootzoneundercommonpractices. Giventheabovefindings,clarificationisneededregardinghowsalinitywillbemanagedwithineachgroundwaterbasin/subbasintoprovidetheappropriatelevelofprotectionoftheAGRbeneficialuseandestablishprocedurestominimizedegradationandwhereneededreducesaltloadingtoachievebalanceandensurelong‐termprotectionoftheAGRuse.Accordingly,theAGRPolicyascurrentlyformulatedrecommendstheBasinPlansbeamendedtoassignAGRClassestogroundwaterbasins/subbasinsbasedoncurrentambientsaltconcentrationsintheproductionzoneofeachbasin/subbasin.Specifically,
AGRClass1:TDS<600mg/L(EC<1,000µS/cm).Groundwaterqualityintheproductionzonethatmaybeusedasanagriculturalwatersupplyisgenerallysuitableforirrigatingallcropsandallstockwatering.
AGRClass2:600mg/L<TDS<2,000mg/L(1,000µS/cm<EC<3,000µS/cm).Groundwaterqualityintheproductionzonethatmaybeusedasanagriculturalwatersupplyisgenerallyacceptableforstockwateringandforirrigatingmostsalt‐tolerantcrops;
8InStateWaterBoardOrderWQO2004‐0010,theStateWaterBoardrecognizedthatuseofthemostconservativevaluefortheprotectionofthemostsaltsensitivecropmaynotbeappropriateandthattheRegionalBoardmustconsidersite‐specificconditionsandallowsomerelaxationasdeterminedappropriate.
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Section 4 Central Valley Salt and Nitrate Management Strategy
itisnotgenerallysuitableforirrigatingmanysalt‐sensitivecrops,exceptasatemporary,short‐termalternativewhenhigherqualitywatersuppliesarenotreadilyavailable.
AGRClass3:2,000mg/L<TDS<5,000mg/L(3,000µS/cm<EC<7,500µS/cm).
Groundwaterqualityintheproductionzonethatmaybeusedasanagriculturalwatersupplyisgenerallyacceptableforstockwateringbutisnotgenerallysuitableforirrigatingallbutthemostsalt‐tolerantcrops,exceptasatemporary,short‐termalternativewhenhigherwaterqualitywatersuppliesarenotreadilyavailable.
AGRClass4:TDS>5,000mg/L(EC>7,500µS/cm).GroundwaterqualityintheproductionzonethatisnotsuitableforeitherstockwateringorcropirrigationAGRusesunlessblendedwithlowersalinitywater.AreaswithinthisclassificationshouldbeconsideredforAGRde‐designation.
TheAGRclassesasdescribedabovearenotproposedforincorporationintotheBasinPlansatthistime.Instead,theassignmentofthesepotentialclassesandtheirassociatedTDS/ECranges,basedonambientTDS/ECconcentrationintheproductionzoneofgroundwaterbasins/subbasins,willbeevaluatedovertimeaspartoftheimplementationoftheSalinityManagementsectionofthisSNMP.AftercompletionofthePhaseI–PrioritizationandOptimizationStudy(seeSection4.3.3),theseAGRclassesandtheirrangesorotherapproacheswillbere‐evaluatedforpotentialinclusionintheBasinPlansthroughafutureamendmentprocess.
Salinity Variance Policy (Attachment A‐6)
OnJune6,2014,theCentralValleyWaterBoardadoptedamendmentstotheBasinPlansthatincludedaVarianceProgramforSalinity(SalinityVarianceProgram)9.OnMarch17,2015,theStateWaterBoardadoptedResolutionNo.2015‐0010approvingBasinPlanamendmentstoincludetheSalinityVarianceProgram.BecausetheSalinityVarianceProgramappliestosurfacewaters,andisconsideredawaterqualitystandardsactionundertheCleanWaterAct,theSalinityVarianceProgramwassubjecttoapprovalbytheUnitedStatesEnvironmentalProtectionAgency(USEPA).USEPAapprovedtheSalinityVarianceProgramonJuly8,2016.Withitsapproval,U.S.EPAspecificallylimitedapplicationoftheSalinityVarianceProgramtoeffluentlimitationsbeingadoptedtoprotecttheAGRbeneficialuse.Further,theSalinityVarianceProgramappliesonlytomunicipalpublicallyownedtreatmentworks(POTWs)thathaveasituationsimilartoorcomparabletothecasestudycitiesincludedintheCentralValleyWaterBoard’ssupportingdocuments.
WhenitadoptedtheSalinityVarianceProgram,theCentralValleyWaterBoardrecognizedthatmanagementofsalinityinsurfaceandgroundwatersisamajorchallengefordischargers.TheCentralValleyWaterBoardfurtherdeterminedthatduringthedevelopmentandinitialimplementationoftheSNMP,inpreparationbyCV‐SALTS,itwasappropriatetoallowmunicipalanddomesticwastewaterdischargersthatqualifiedtoapplyforavariancefromsalinitywater
9CentralValleyWaterBoardResolutionNo.R5‐2014‐0074.
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Section 4 Central Valley Salt and Nitrate Management Strategy qualitystandardsiftheyhave,orwillhave,waterqualitybasedeffluentlimitationsforsalinitythattheyareunabletomeet.10
TheSalinityVarianceProgramappliestosalinitywaterqualitystandardsthataredefinedtoincludewaterqualitystandardsforonlythefollowingconstituents:electricalconductivity,totaldissolvedsolids,chloride,sulfateandsodium.ThecurrentSalinityVarianceProgramprohibitstheCentralValleyWaterBoardfromapprovinganysalinityvarianceafterJune30,2019.ThesunsetdatewasincludedbecausetheCentralValleyWaterBoardintendedthatanyextension,orpermanent,long‐termSalinityVarianceProgramshouldbedevelopedthroughtheCV‐SALTSprocessandthatstakeholdersneededtomakeappropriaterecommendationsforsuchapolicyintheSNMP.InaccordancewiththeCentralValleyWaterBoard’sdirectionindevelopingthecurrentSalinityVarianceProgram,thisSNMPrecommendsthattheSalinityVarianceProgrambeextendedforanadditional15years.SeeAttachmentA‐6foradditionalinformation.
Offsets Policy (Attachment A‐7)
AnoffsetisanalternativemeansofachievingcompliancewithaWDR,eitheraloneorincombinationwithotheractions,foragivenpollutantorpollutants.Anoffsetallowsforthemanagementofothersourcesandloads(notdirectlyassociatedwiththeregulateddischarge)sothatthecombinedneteffectonreceivingwaterqualityfromthedischargeandtheoffsetisfunctionally‐equivalentto(andpotentiallybetter)thanthatwhichwouldhaveoccurredbyrequiringthedischargertocomplywithitsWDRatthepoint‐of‐discharge.Inthisregard,anoffsetprojectmustbelocatedwithinthesamegroundwaterbasin/subbasinormanagementzoneastheregulateddischarge.
TheSNMPincludesanOffsetsPolicy(seeAttachmentA‐7),whichrecommendsthattheBasinPlansbeamendedtoprovideauthorityfortheCentralValleyWaterBoardtoallowtheuseofoffsetprojectstocomplywithWDRs,butonlyforgroundwater.InadditiontoanoffsetprojectbeingusedtosupportcompliancewithaWDR,offsetsmaybeproposedtosupportarequestforeitheranallocationofavailableassimilativecapacityoranexception(seeNitratePermittingStrategy[AttachmentA‐2]andExceptionsPolicy[AttachmentA‐4],respectively).Ultimately,thedecisiontopursueanoffsetisvoluntary.Offsetsmustbe(1)proposedbydischarger(individualorgroupofdischargers)asanAlternativeComplianceProject(ACP,seeAttachmentA‐10andsummarybelow);(2)approvedbytheCentralValleyWaterBoard;and(3)enforceablethroughaWDRorotherordersissuedbytheBoard.
Asnotedabove,thisSNMPrecommendsthattheOffsetsPolicybeapplicableonlytogroundwateratthistime.However,duringimplementationofthePhaseI–PrioritizationandOptimizationStudy(seeSNMPAttachmentA‐3andSection4.3.3,SaltManagement,below),anOffsetPolicyforsurfacewatermaybeconsideredforpotentialinclusionintheBasinPlansthroughafutureBasinPlanamendmentprocess.
10AmendmentstotheWaterQualityControlPlanfortheSacramentoRiverandSanJoaquinRiverBasinsandtheWaterQualityControlPlanfortheTulareLakeBasintoaddPoliciesforVariancesfromSurfaceWaterQualityStandardsforPointSourceDischargers,VarianceProgramforSalinity,andExceptionfromImplementationofWaterQualityObjectivesforSalinity,FinalStaffReport,June2014(FinalStaffReport),atp.45.
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Section 4 Central Valley Salt and Nitrate Management Strategy Finally,tosupportimplementationofthispolicy,itmaybeappropriatetoestablishamitigationfunddesignedtodevelopandimplementwaterqualityimprovementprojectswithinthesamereceivingwaterbasin,subbasinormanagementzonewherethedischargeoccurs.Thismaybeparticularlyusefulforpoolingtheresourcesofmanyrelativelysmalldischargersintoacriticalmassoffundingtosupportwaterqualityprojectsthatwouldnormallybebeyondthemeansofindividualdischargerstofund.EstablishmentofamitigationfundwilllikelyrequireCalifornialegislation.Accordingly,whilethisSNMPsupportstheuseofamitigationfundtosupportimplementationofthispolicy,noneareproposedtobeestablishedatthistime.
Drought and Water Conservation Policy (Attachment A‐8)
Theeffectsofdroughtandtheimplementationofencouragedormandatedwaterconservationpracticescansignificantlyimpacteffluentqualityindischargestosurfacewaterorgroundwater.AttachmentA‐8providesadetaileddiscussionoftheseissues.ThetextbelowprovidesanoverviewandsummaryofrecommendationstosupportimplementationofthisSNMP.
Historically,WDRs/ConditionalWaiversrarelyhaveincludedanyspecialprovisionorconsiderationforvariationsineffluentquality,directlyorindirectlyrelatedtorecurrentdroughtconditionsthatarebeyondthecontrolofthedischargerorforongoing,expandingandsometimesmandatedconservationpractices.However,extendedperiodsofbelownormalprecipitation(i.e.,“droughts”)aswellasextensiveconservationpracticescancreatecomplianceissuesforsomedischargersbecauseofincreasedTDS/ECandothersalinity‐relatedconstituentsininfluentandeffluent.Thisproblemiscausedbythefollowingconditionsassociatedwithperiodsofdrought:
Whenlesshighquality(lowTDS/EC)surfacewaterisavailable,wateragenciesmayincreaserelianceonlowerquality(higherTDS/EC)groundorlowerqualitysurfacewatertoaugmentsupplies.MosttreatmentsystemsarenotdesignedtoremoveTDS/EC;thushighersalinityinthewatersupplycanresultinhighersalinityineffluent.
Mandatoryconservationmeasuresduringprolongeddroughtmaysignificantlyalterthebehaviorofwaterusers.Thecumulativeeffectisreducedwateruse,whichpreviouslyhelpeddiluteaverageTDS/ECconcentrationinrawsewageandtreatedwastewater.
Drought‐relatedchangesinwaterqualitymaytemporarilyaggravatethemorepermanentlong‐termtrendtowardsincreasedTDS/ECininfluentcausedbyadoptionofhighefficiency,low‐flowfixturesandappliances,andgreateruseofin‐homewatersofteners.
Evenwherewastewaterfacilitiesareabletohandlealong‐termtrendofrisingTDS/ECintheinfluent,drought‐relatedconditionsmaytemporarilyeliminatethesmallbutcriticalbufferneededtoassureconsistentcompliancewithsalinity‐basedpermitdischargerequirements.
Droughtconditionscreatesimilarconcernsforagriculturaloperatorsandindustrialusers.Reducedavailabilityofhighquality(lowTDS/EC)surfacewaterforcesincreasedrelianceonlowerquality(highTDS/EC)sources(e.g.,groundwaterand/orreuseofirrigationreturnflows),resultingintemporarilyhigherTDS/ECconcentrationsrechargingtogroundwaterbelowtherootzone.Theinabilitytoassureconsistentpermitcomplianceforsalinitydiscouragestheuseofrecycledwaterforlandscapeorcropirrigationandmay
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Section 4 Central Valley Salt and Nitrate Management Strategy
createdisincentivestogreaterimplementationofmoreefficient(drip‐style)irrigationsystems.
Oncewaterconservationpracticesareimplemented,theyarelikelytocontinue,especially
iftheynecessitatedcapitalinvestment(i.e.redirectionforlandscapeirrigation,lowflushtoilets,dripirrigation,etc.).
Finally,permiteffluentrequirementsforTDS/ECaretypicallyevaluatedusingrelativelyshort‐termaveragingperiods(e.g.,daily,weekly,monthlyaveragesormeans).Sincedroughtstypicallypersistforseveralyears,evenpermitlimitsexpressedasanannualaveragemaybeimpracticaltomeet.
Giventheaboveconcerns,theSNMPproposesamendmentstotheBasinPlanthatspecificallyaddresssalinity‐relatedconcernsassociatedwiththeimpactsofdroughtorincreasedimplementationofwaterconservationpractices.Specifically,
Fordischargestogroundwater,calculatecompliancewiththeapplicablenarrativeornumericsalinityobjectivesusingalong‐term(10+year)flow‐weightedaveragewhilealsotakingintoconsiderationtheexpectedrechargeandpotentialdilutionfromnaturalprecipitationandstreambedpercolationtothesamebasinorsubbasin.
AuthorizetheuseofoffsetprojectsconsistentwiththisSNMP’sOffsetsPolicy(seeAttachmentA‐7),particularlyincreasedstormwatercaptureandrecharge,todemonstratecompliancewithWDRsgoverningsalinitydischarges.AllowoffsetcreditstobecreatedandbankedbyconstructingandoperatingsuchprojectsorbydischargingwellbelowtheWDRthresholdinnon‐droughtyears.Recognizethatthecreditsneededtoachievecomplianceduringperiodsofdroughtnormallymustbegeneratedattimesofabovenormalprecipitation(especiallyElNiñowinters)and,assuch,mustremainvalidoverasufficientlylongplanninghorizon,i.e.,atleast20yearsinordertobeuseful.
ConsideramendingtheBasinPlanstoestablishatemporaryvariance/exceptionfromsalinity‐relatedstandardsduringcertaindroughtconditions.Thevariance/exceptionwouldbeautomaticallyactivatedwhenoneofthefollowingtriggersoccurs:(a)adroughtemergencyisdeclaredbyanauthorizedfederalorstateauthority;11(b)duringanextendeddryperiodinReach83oftheLowerSanJoaquinRiver(MercedtoVernalis)asdefinedbytheSRSJRBasinPlans;12or(c)declarationofalocalemergencyconsistentwiththeCaliforniaEmergencyServicesAct.13Atsuchtimes,moreappropriateinterimWDRsoreffluentlimits,suchastheshorttermMCLof2,200µmhos/cmEC,wouldapply.
ConsideramendingtheBasinPlanstoestablishatemporaryvariance/exceptionfromsalinity‐relatedstandardswheretheTDS/ECconcentrationinthepermitteddischargeis
11CaliforniaGovernmentCodeSectionTitle2,Division1,Chapter7,CaliforniaEmergencyServicesAct;alsoseehttp://www.water.ca.gov/waterconditions/declaration.cfm12SeeproposedBasinPlanamendment:EstablishmentofSalinityWaterQualityObjectivesintheLowerSanJoaquinRiver,fromtheMouthoftheMercedRivertoVernalis.http://www.waterboards.ca.gov/centralvalley/water_issues/salinity/upstream_salt_boron/index.shtml13CaliforniaGovernmentCodeSectionTitle2,Division1,Chapter7,CaliforniaEmergencyServicesAct.
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Section 4 Central Valley Salt and Nitrate Management Strategy
better(lower)thantheTDS/ECconcentrationinthereceivingwaterandwillimprovereceivingwaterquality(evenwhenthereceivingwaterqualityishigherthantheSMCL)bypromotingmaximumuse/reuseofavailablewatersupplies.Potentialimpactstodownstream/downgradientwaterqualitymustalsobeevaluatedaspartofthisdemonstration.
Inlieuofauthorizingatemporaryvariance/exception,considerpre‐authorizinganautomaticallocationofassimilativecapacity(whereitexists,orcanbeprovidedbythedischarger,e.g.,viaanoffsetproject)toaccommodatehigherTDSconcentrationsinthedischarge/rechargeduringdroughtconditions.
Guidance to Implement Secondary Maximum Contaminant Levels (Attachment A‐9)
TheSNMPincludesrecommendationsfortheincorporationofguidanceintotheBasinPlanstosupportandclarifyimplementationofSecondaryMaximumContaminantLevels(SMCL)inpermitsfordischargetosurfacewaterandgroundwater(seeAttachmentA‐9).SMCLsaresecondarydrinkingwaterstandards,definedbytheCaliforniaHealthandSafetyCodeas:
“…standardsthatspecifymaximumcontaminantlevelsthat,inthejudgmentofthedepartment,arenecessarytoprotectthepublicwelfare.Secondarydrinkingwaterstandardsmayapplytoanycontaminantindrinkingwaterthatmayadverselyaffecttheodororappearanceofthewaterandmaycauseasubstantialnumberofpersonsservedbythepublicwatersystemtodiscontinueitsuse,orthatmayotherwiseadverselyaffectthepublicwelfare.Regulationsestablishingsecondarydrinkingwaterstandardsmayvaryaccordingtogeographicandothercircumstancesandmayapplytoanycontaminantindrinkingwaterthatadverselyaffectsthetaste,odor,orappearanceofthewaterwhenthestandardsarenecessarytoensureasupplyofpure,wholesome,andpotablewater.”14
FollowingaretheareaswhereclarificationorguidanceisrecommendedtosupporttheimplementationofSMCLsindischargepermits: SMCLsestablishedby22CCR(thedrinkingwaterregulations)areincorporatedby
referenceintheChemicalConstituentsectionsintheWaterQualityObjectivesChapteroftheBasinPlans.Theonlyportionsof22CCRrelatedtoSMCLsandincorporatedintotheBasinPlansareTables64449‐Aand64449‐B(Tables4‐1and4‐2,respectively).Table64449‐Bincludes“Recommended”,“Upper”,and“ShortTerm”concentrationsforTDSorSpecificConductanceorEC,chlorideandsulfate.WhiletheSMCLswereincludedintheBasinPlansforthepurposeofprotectingthedrinkingwateruse,neitherthetextprovidingcontextforthetablesnorguidanceforutilizingtheapplicable“Recommended”,“Upper”,or“ShortTerm”concentrationswasincludedwhenthe22CCRtableswereadoptedaswaterqualityobjectives.ThelackofguidanceonthetierednumericvaluesinTable64449‐BhasledtoinconsistentapplicationinWDRs.
14CaliforniaHealthandSafetyCode,Division104EnvironmentalHealth,Part12DrinkingWater,Chapter4CaliforniaSafeDrinkingWaterAct,Article1,Section116275(d)
Section 4 Central Valley Salt and Nitrate Management Strategy
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Table 4‐1. Table 64449‐A: Secondary Maximum Contaminant Levels; “Consumer Acceptance Contaminant Levels” (22 CCR §64449)
Constituents Maximum Contaminant Levels/Units
Aluminum 0.2 mg/L
Color 15 Units
Copper 1.0 mg/L
Foaming Agents (MBAS) 0.5 mg/L
Iron 0.3 mg/L
Manganese 0.05 mg/L
Methyl‐tert‐butyl ether (MTBE) 0.005 mg/L
Odor – Threshold 3 Units
Silver 0.1 mg/L
Thiobencarb 0.001 mg/L
Turbidity 5 Units
Zinc 5.0 mg/L
Table 4‐2. Table 64449‐B: Secondary Maximum Contaminant Levels; “Consumer Acceptance Contaminant Level Ranges” (22 CCR §64449)
Constituents, Units Recommended Upper Short Term
Total Dissolved Solids (TDS), mg/L, or
Specific Conductance, µS/cm15
500 1,000 1,500
900 1,600 2,200
Chloride, mg/L 250 500 600
Sulfate, mg/L 250 500 600
InCalifornia,thesecondarydrinkingwaterstandardsareenforceableandcommunitywatersystemsarerequiredtoassesscompliancewithSMCLsbymonitoringtheirsurfacewaterorgroundwatersourcesormonitoringtheirdistributionsystementrypointsfollowingsourcetreatment.16Groundwaterundergoessomenaturalfiltrationasthatwatermovesthroughthevadosezone.USEPA'sdrinkingwaterregulationsrequirenearlyallsurfacewatersourcestobefiltered.17Therefore,inmostcases,thewaterusedtodemonstratecompliancewiththeSMCLshasbeenfilteredbeforetherepresentativesamplesarecollected.Thereisnoneedforthecommunitywatersystemstoapplyanyadditionalfiltrationtothesamplebeforeitisanalyzed.
Fordischargestogroundwater,wastewatersamplescollectedatthepoint‐of‐dischargehavenothadanopportunitytoundergotheprocessofnaturalfiltrationthatoccursassuchdischargespercolatethroughthevadosezonebeforereachingtheaquifer.Filteringsuch
15 For the purposes of this policy, Specific Conductance is expressed as Electrical Conductivity. 16 22 CCR §64449(b) 17 US EPA. National Primary Drinking Water Regulations: Long Term 2 Enhanced Surface Water Treatment Rule. 71 FR 654. January 5, 2006. Exceptions are sometimes granted for community water systems that rely that rely protected watersheds (ex. Hetch‐Hetchy reservoir).
Commented [A4]: Many surface waters are low in secondary MCL contaminants and source treatment is not required, therefore water utilities monitor the source water for compliance. Drinking water filtration applied is not equivalent to the dissolved analysis filtration at 0.45 um.
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Section 4 Central Valley Salt and Nitrate Management Strategy
samples,priortoacidifyingandanalyzingthesample,isintendedtomimicthenaturalfiltrationprocessthatisexpectedtooccurbeforethesedischargestogroundwatermightbepumpedfromadowngradientwellbyacommunitywatersystem.Fordischargestosurfacewater,wastewatersamplesshouldbesubjectedtothesamefiltrationrequirementsthatcommunitywatersystemsarerequiredtomeetbeforesuchsamplesareacidifiedandanalyzedtodeterminecompliancewiththeSMCLsfortracemetals.Requiringdischargerstouseanunfilteredsampleimproperlyassumesthatthewastewaterwillbeusedasadrinkingwatersupplywithnoadditionalnaturalorman‐madetreatmentbetweenthepoint‐of‐dischargeandtheentrypointtothemunicipalwaterdistributionsystem.Asbothapracticalandlegalmatter,thatisneverthecase.
TheBasinPlansdonotcurrentlyprovideguidanceontheassessmentperiodthatshouldbeusedtodeterminecompliancewithSMCLs.Per22CCR§64449,compliancewiththeSMCLsinTable64449‐AandTable64449‐Bfordrinkingwatersystemsvariesdependingonthesource,withgroundwatersourcesbasedonasingletriennialsampleandsurfacewatersourcesbasedonasingleannualsample.ItisrecommendedthattheBasinPlansbeamendedtoincorporatetextthatdefinestheassessmentperiodfordeterminingcompliancewithSMCLs.Specifically,languageshouldbeaddedtotheimplementationsectionoftheBasinPlanstostatethatanevaluationofcompliancewithSMCLsinTables64449‐Aand64449‐Bshallbeataminimumbasedonanannualaverageofcollectedsamplesfromallanalyticalresultscollectedfromwherecomplianceisdetermined.Thisapproachissimilarto22CCR§64449(c)(1)asitappliestoTable64449‐A.22CCR§64449doesnotprovideacompliancedeterminationapproachforTable64449‐Bconstituents;regardless,thesamecomplianceassessmentapproachisrecommendedfortheconstituentsinbothTable64449‐Aand64449‐B.
Guidance for Developing Alternative Compliance Projects for Nitrate Discharges (Attachment A‐10)
Whenanindividual(orthirdpartygroupsubjecttoaGeneralOrder)orgroupofdischargersisunabletodemonstratethattheirdischargeisnotindividuallyorcollectivelycausingorcontributingtonitratedegradationabovethetriggersidentifiedintheCentralValleySNMP(seeSection4.3.2andAttachmentA‐2),theyhaveanopportunitytorequesteitherallocationofavailableassimilativecapacityoranexception.Inmostcases,therequestforthegrantingofassimilativecapacity18oranexceptioninthesecircumstancesrequiressubmittalofaproposedACP.Thisrequestmaybemadeasanindividualdischarger(whichincludesathirdpartygroupsubjecttoaGeneralOrder)ordischargersworkingcollaborativelyaspartofagroundwatermanagementzone.WhiletheCentralValleyWaterBoardhasthediscretiontodenysucharequest,anyproposedACP(s)submittedforconsiderationmustcontainspecificcomponents.AttachmentA‐10providesguidanceoftheminimumcomponentsrequiredforsubmittalofanACPforapproval.Examplesofthekeyminimumcomponentsinclude:
18Conditionswithrespecttograntingofassimilativecapacitywillvary,dependingonhowthereceivingwaterisdefinedforthedischarge(s)inquestion.Insomecases,thereceivingwaterwillbeconsideredtobeshallowgroundwater,whileinothers,itmaybetheupperzoneorproductionzoneasdefinedatSection3.
Commented [A5]: The SRSWPP disagrees with the plan to use 0.45 micron filtered water results for compliance with various SMCLs. See attached supporting information, previously provided to CV‐Salts. DDW confirmed in comments provided on 8/1/16 that filtered metals results are not used for drinking water compliance monitoring. We request that the issue of fate and transport of metals be further reviewed to ensure that the policy provides appropriate long‐term protection of source water quality.
Commented [A6]: Please include information on mechanisms available to dischargers for relief, including how dilution credits and mixing zones are used.
Section 4 Central Valley Salt and Nitrate Management Strategy
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ConsistencywiththemanagementgoalsoftheCentralValleySNMP,includingaddressingshort‐termandlong‐termdrinkingwaterneedsaffectedbynitrates,planforachievingbalancednitrateloadingswithintheproposedboundariesoftheproject,wherefeasibleandreasonable,andaplanforestablishingamanagedaquiferrestorationprogramtorestorenitratelevelstoconcentrationsatorbelowthewaterqualityobjectivestoextentreasonableandfeasible.
Assurethatdrinkingwaterthatmeetsdrinkingwaterstandardsisavailabletodrinkingwateruserswithinthezoneofinfluenceofadischargewheretherearesignificantnitrateconcernsingroundwater.ThiscomponentmaybemetthroughthedevelopmentandimplementationofanEarlyActionPlan(EAP)(e.g.,seeSection4.3.2.1belowortheNitratePermittingStrategy[AttachmentA‐2]).
Outreachthatwilloccurtoinsurethatstakeholdersoraffectedcommunitieswithinthezoneofinfluenceofadischarge,includingcommunitieswithdrinkingwaterqualityconcerns,areinformedof,andgivenopportunitytoparticipatein,thedevelopmentofanyACPproposalaswellasongoingactivitiesdesignedtoresolvetheirdrinkingwaterconcerns.
Identificationofshort(≤20years)andlong‐term(>20years)projectsand/orplanningactivitiesthatwillbeimplementedaspartoftheACPtomakeprogresstowardsattainingeachofthewaterquality‐relatedmanagementgoalsestablishedbytheCentralValleySNMPwithinthezoneofinfluence.Formanagementzones,projects/planningactivitiesmaybeprioritizedtobetterallocateresources.Overtimeaswaterqualityimprovesinprioritizedareas,updatestotheACPmayshiftthepriorities.
Shortandlong‐termschedulesforimplementationofnitratemanagementactivitieswithinterimmilestonesandperformancemeasurestoassessprogress,andidentificationoftriggersfortheimplementationofalternativeproceduresormeasurestobeimplementediftheinterimmilestonesarenotmet.
SurveillanceandmonitoringprogramthatisadequatetoassurethattheACPwhenimplementedisachievingtheexpectedprogresstowardsattainmentofwaterquality‐relatedmanagementgoals.
Identificationoftheresponsibilitiesofeachregulateddischarger,orgroupsofregulateddischargersifparticipatinginamanagementzone,tomanagenitrate.
Factors to Support a Maximum Benefit Finding (Attachment A‐11)
TheStateAntidegradationPolicy(No.68‐16)setsforththespecificconditionsthatmustbemetanddemonstrationsthatmustbemadebeforetheCentralValleyWaterBoardcanallowadischarge(ordischarges)tolowerwaterqualityinanexistinghighqualitywater:
(1) “Whenevertheexistingqualityofwaterisbetterthanthequalityestablishedinpoliciesasofthedateonwhichsuchpoliciesbecomeeffective,suchexistinghighqualitywillbemaintaineduntilithasbeendemonstratedtotheStatethatanychangewillbeconsistentwithmaximumbenefittothepeopleoftheState,willnotunreasonablyaffectpresent
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Section 4 Central Valley Salt and Nitrate Management Strategy
andanticipatedbeneficialuseofsuchwaterandwillnotresultinwaterqualitylessthanthatprescribedinthepolicies.
(2) Anyactivitywhichproducesormayproduceawasteorincreasedvolumeorconcentration
ofwasteandwhichdischargesorproposestodischargetoexistinghighqualitywaterswillberequiredtomeetwastedischargerequirementswhichwillresultinthebestpracticabletreatmentorcontrolofthedischargenecessarytoassurethat(a)apollutionornuisancewillnotoccurand(b)thehighestwaterqualityconsistentwithmaximumbenefittothepeopleoftheStatewillbemaintained”(emphasisadded).19
TosupportimplementationofthisSNMP,itsproposedmanagementstrategiesandpolicies,AttachmentA‐11providesguidanceformakingafindingthataproposedprojectmeetsthetestthatitsapprovalandimplementationwouldbe“consistentwiththemaximumbenefittothepeopleofthestate”test,asstatedintheStateAntidegradationPolicy.
4.2.3 Related Basin Plan Amendments InparallelwiththedevelopmentofthisSNMPandrecommendationsforBasinPlanamendmentstosupportitsimplementation,CV‐SALTShasbeendevelopingotherBasinPlanamendmentsthatsupportsalinity‐relatedmanagementrequirementsonawaterbodyorwatershed‐specificbasis.TheserelatedBasinPlanamendmentsandpotentiallinkagestothisSNMParesummarizedbelow.
4.2.3.1 MUN Beneficial Use Project – Agriculturally Dominated Water Bodies Evaluation PertheState’sSourcesofDrinkingWaterPolicy(StateWaterBoardResolutionNo.88‐63)theBasinPlansdesignateMUNasabeneficialuseonallwaterbodiesunlesstheyarespecificallylistedaswaterbodiesthatarenotdesignatedwithMUN.TheBasinPlansstatethatwatersdesignatedforMUNmustnotexceedMaximumContaminantLevels(MCLs,primaryorsecondary)forchemicalconstituents,pesticides,andradionuclides,andvariousnarrativestandardsthatapplytoMUN(aswellasotherbeneficialuses).WhileResolution88‐63doescontainexceptionsfortheMUNdesignationsuchaswaterbodiesconstructedormodifiedfortheprimarypurposetoconveyorholdagriculturaldrainage,toutilizetheexceptiontheBasinPlansrequireaformalBasinPlanamendment.
DuringNPDESpermitadoptionstherehavebeenchallengestotheneedtoprotecttheMUNbeneficialusedesignationinagriculturaldrainsduetotheexceptionsidentifiedinStatePolicy88‐63.Concurrently,CV‐SALTSidentifiedtheneedtoevaluatetheprotectionofMUNbeneficialusesinagriculturallydominatedwaterbodies.CV‐SALTS,incoordinationwithCentralValleyWaterBoardstaff,conducteditsMUNevaluationofthesetypesofwaterbodiesintwophases:
AgriculturalDrainsReceivingTreatedWastewater‐CV‐SALTSidentifiedreceivingwatersoffourPOTWs(CitiesofWillows,Colusa,BiggsandLiveOak)aspotentialcasestudiesforevaluatingtheappropriatenessoftheMUNdesignation.ThecostforwastewaterfacilitiestocomplywithprotectingtheMUNbeneficialusehadbeenestimatedat$3‐$7million
19StateWaterBoard.StatementofPolicywithRespecttoMaintainingHighQualityofWatersinCalifornia.ResolutionNo.68‐16(October28,1968).
Commented [A7]: Please see mark‐up comments below.
Commented [A8]: Since there are two separate Basin Plan Amendments that could significantly impact the protection of the MUN beneficial use (SMCL Policy and MUN De/Re‐Designation), should there be a cumulative impact analysis of these two programs? Removing significant amounts of designated waterbodies and also reducing protections of SMCLs could cumulatively degrade downstream water quality and impact the MUN use.
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Section 4 Central Valley Salt and Nitrate Management Strategy
(e.g.,CityofWillows)andthesesamePOTWschallengedtheMUNdesignationduringrenewaloftheirNPDESpermits.FollowingthecompletionofrequiredanalysesandconsistentwithStatePolicy88‐63toproposeremovalofMUNfromthereceivingwater,CentralValleyWaterBoardstaffpreparedthedocumentationtosupportaBasinPlanamendmenttoremoveMUNfrom12waterbodiesagriculturaldrainagesdownstreamofthesefourPOTWs.Allofthesewatersbodiesmetexceptioncriterion2bintheSourcesofDrinkingWaterResolution88‐63.ThisBasinPlanamendmentwasapprovedbytheCentralValleyWaterBoardandStateWaterBoardonApril15andAugust18,2015,respectively)20andapprovedbytheEnvironmentalProtectionAgencyonApril21,2016.Inpart,theamendmentdevelopedastandardizedmethodforevaluatingandcategorizingagriculturallydominatedwaterbodiesintoconstructed,modifiedornatural.
Region‐wideMUNEvaluationProcessandAdoptionofaLimitedMUNBeneficialUse–TheCentralValleyWaterBoardiscurrentlyworkingonasecondBasinPlanamendmenttoestablishaCentralValleyregion‐wideprocessforevaluatingtheMUNbeneficialuseinagriculturallydominatedsurfacewaterbodiesbasedontheprocessutilizedinPhase1andadoptaLimitedMUN(LMUN)use.Ifadopted,theBasinPlanswouldareproposedtobeamendedto:
EstablishanewwaterbodycategorizationframeworkthattheBoardcouldutilizetodeterminetheappropriateapplicationof,andlevelofprotectionfor,theMUNbeneficialuseindifferenttypesofagriculturallydominatedsurfacewaterbodiesacrosstheCentralValley.TheproposedBasinPlanamendmentdistinguishesamongagriculturally‐dominatedwaterbodiesthathavebeenconstructedormodifiedfortheprimarypurposetoconveyorholdagriculturaldrainage,waterbodiesthathavebeenconstructedormodifiedtoconveyagriculturalsupplywater,naturalwaterbodiesdominatedbyagriculturaloperations,andwaterbodiesencompassedinapermanentorseasonalclosedrecirculatingbasin.Theamendmentproposestoutilize,whereappropriate,SourcesofDrinkingWaterPolicy88‐63Exception2btode‐designatetheMUNbeneficialuse.
EstablishanewLMUNbeneficialuse,proposedtobedefinedas:“Usesofwaterformunicipalanddomesticsupplyinagriculturallydominatedsurfacewaterbodieswheretheuseislimitedbywaterbodycharacteristicssuchasintermittentflow,managementtomaintainintendedagriculturaluseand/orconstituentconcentrationsinthewaterbody.”TointerpretthenarrativeobjectiveandtoevaluatecompliancewiththeproposedobjectiveforLMUN,existingmonitoringprogramsmayusenumerictriggersforchemicalconstituents,pesticides,andradionuclidesconcentrationintheirprocessofissuingpermitsorwastedischargerequirements.Exceedancesofthetriggerswouldnotbeviolationsoftheproposednarrativeobjectivenorarethetriggerstobeusedfornumericeffluentlimits.Triggerswillbeusedtoevaluateimpactstodownstreambeneficialusesandensureappropriatemanagementandbestpracticaltreatmentactionsaretakentoprotectthosedownstreamuses.
DischargerscanfinditextremelydifficulttomaintainagriculturaloperationsandincreasewaterrecyclingeffortswhilealsocomplyingwithMCLs(especiallyforsalinity‐relatedconstituents)in
Commented [A9]: We recommend this sentence be deleted or revised substantially. The BPA did not include a method for evaluating and categorizing ag dominated waterbodies in it. All of these de‐designations were predicated on application of SDWP Exception 2b to ag drainages and all supporting materials were related to that exception. No method for other ag dominated waterbody evaluations was presented or approved in the Amendment.
Commented [A10]: We recommend this deletion as it could be misinterpreted that the POTW BPA (Phase 1) created and utilized a method to be used in Phase 2, which is not the case. All the de‐designations in the POTW BPA (Phase 1) met the SDWP Exception 2b and did not require application of a new evaluation method. The new method to evaluate ag dominated water bodies will need to be approved by the Regional Board as part of this regionwide BPA.
Commented [A11]: Suggested edits from the SRSWPP, as the LMUN definition and water quality objective have not yet been approved by the Regional Board. We continue to have comments and concerns on these items.
Commented [A12]: It remains to be considered if there is sufficient long‐term monitoring planned to ensure long‐term protection of the LMUN water bodies for future water use as well as protection of downstream MUN use. It appears to be premature to include “existing” in the SNMP ahead of completion of the BPA public process for the MUN project.
Commented [A13]: There are other narrative WQO that apply to MUN that will not have triggers and they should also be considered when evaluating impacts to downstream MUN.
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20CentralValleyWaterBoardResolutionNo.R5‐2015‐0022;StateWaterBoardResolutionNo.2015‐0055
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Section 4 Central Valley Salt and Nitrate Management Strategy agriculturaldrainsthatwerenotconstructedfortheprimarypurposetosupplydrinkingwater.Consequently,establishmentofaregion‐wideprocesstoevaluatetheapplicabilityoftheMUNbeneficialuseonagriculturaldrainsprovidesanimportanttooltosupportimplementationofthisSNMP.TheBasinPlanamendmentisexpectedtobeproposedforadoptionin2017.21
4.2.3.2 Evaluation of MUN and AGR Beneficial Uses in a Portion of Historical Tulare Lakebed Groundwater TheCentralValleyWaterBoard,inconjunctionwithCV‐SALTS,isproposingtoamendtheTLBBasinPlantode‐designateMUNandAGRbeneficialusedesignationsfromaportionofthegroundwaterinthehistoricTulareLakebed.22TheProjectStudyAreaislocatedinthesouthernpartoftheCentralValleyofCaliforniaintheTulareLakeBasin.TheTulareLakeBasinessentiallyfunctionsasaclosedbasinexceptduringextremefloodyears,whensomeKingsRiverwatermovesnorththroughFresnoSloughintotheSanJoaquinRiver.BecausetheTulareLakeBasinisaclosedbasin,saltshavebeennaturallydepositedandaccumulatedsinceitsformationandbeforeanyinfluencefromhumans.Thediversionofwaterintothebasinfromotherwatershedstosupport3millionacresofagriculture,(Sholes2006)includingthreeofthefivemostagriculturallyproductivecountiesintheUnitedStates,23hasexacerbatedtheaccumulationofsalts.TheapplicationofMUNandAGRinthecenterofthehistoricLakeBedhasimpededeffortstoconsolidateandmanagesaltinevaporationbasins. Inadditiontothepotentialde‐designationofMUNandAGRbeneficialusesfromaportionofthegroundwaterundertheTulareLakebed,anotherimportantoutcomeofthiseffortistheestablishmentofaframeworkforevaluatingtheapplicabilityoftheMUNandAGRbeneficialusesandassociatedwaterqualityobjectives,includingimplementationprovisionsapplicableinspecificgroundwaterbasins.ThisframeworkwhichmaybeincorporatedintotheBasinPlans,canprovideanadditionaltoolfortosupportSNMPimplementation.Specifically,theframeworkmaybeappropriateundercertaincircumstancestoevaluatetheapplicabilityofMUNand/orAGRbeneficialusesingroundwatertoencouragereuseandrecycling.Establishingtoolstodeterminetheapplicabilityoftheseusesmayalsoprovideregulatedentitieswithmoreflexibilityinmanaginglimitedwatersupplies,andtheabilitytoidentifypotentialsaltmanagementareasthatwouldhelpmovesaltoutofsensitiveareas.ThisBasinPlanamendmentisexpectedtobeproposedforadoptionin2017.
4.2.3.3 Lower San Joaquin River Salinity Water Quality Objectives
TheCentralValleyWaterBoardisproposingamendmentstotheSRSJRBasinPlanthatwouldestablishsalinitywaterqualityobjectivesinReach83oftheLowerSanJoaquinRiver(LSJR),whichisdefinedastheLSJRfromthemouthoftheMercedRivertoVernalis.Ifadopted,theproposedamendmentwould:
DefinesalinitywaterqualityobjectivesthatareprotectiveofbeneficialusesintheLSJR.Specifically,theamendmentwouldestablishawaterqualityobjectivethatwouldrequire
21http://www.waterboards.ca.gov/centralvalley/water_issues/salinity/mun_beneficial_use/index.shtml22http://www.waterboards.ca.gov/centralvalley/water_issues/salinity/tulare_lakebed_mun_evaluation/index.shtml23http://agcomm.co.tulare.ca.us/default/assets/File/2012CensusCA_1.pdf
Commented [A14]: Please clarify if the issues are only for agricultural drains, or if there are issues with agricultural dominated water bodies.
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Section 4 Central Valley Salt and Nitrate Management Strategy
thatEC(at25degreesCelsius)notexceed1,550(µS/cm)asa30‐dayrunningaverage,exceptduringExtendedDryPeriods,24whenthewaterqualityobjectivewouldrequirethatECnotexceed2,470µS/cmasa30‐dayrunningaverageand2,200µS/cmastheaverageofthepreviousfourconsecutivequarterlysamplesataminimum.
IncorporateintotheSRSJRBasinPlananimplementationprogramtoachieveproposedsalinitywaterqualityobjectives.
Setaperformancegoalof1,350µS/cmduringcertainmonthsandwateryeartypes,based
onmodelingresultsofexpectedwaterquality. Requiretheimplementationofamonitoringandsurveillanceprogramtoevaluatethe
effectivenessoftheimplementationprogram. TheseproposedamendmentswouldsetobjectivesthatwouldbeprotectiveofthetwobeneficialusesintheLSJRthataremostsensitivetosalinityimpacts:AGRandMUN.MUNandtheirrigationsupplycomponentofAGRweredeterminedtobethemostsaltsensitiveusedaftercompletionofseparatestudiesonsalinityimpactstoaquaticlife(Buchwalter2014)andstockwatering(Kennedy/JenksConsulting2013).Inaddition,settinganECperformancegoalwillpromoteachievementofthebestpossiblewaterqualityundervariableconditions,consistentwiththeSNMPDroughtandWaterConservationPolicy(seeAttachmentA‐8).TheproposedamendmentsdonotchangeorreplacetheECwaterqualityobjectivesfortheSanJoaquinRiverattheAirportWayBridgenearVernalisestablishedforwaterenteringthesouthernDelta.25.
TodeterminesalinitylevelsprotectiveofirrigatedagricultureutilizingtheLSJRforsupply,theproposedamendmentusedtheHoffmanModelwithspecificinputsasfollows:
Selectingthemostsaltsensitivecropfromcropscomprising95%ofthecommercial
acreage(i.e.,almonds); Utilizinga15%leachingfraction;
Protectingto95%yield;and
Protectingin95%ofthedriestyears.
Inputswereadjustedtoprotect70%yieldduringextendeddryperiods.
Theproposedwaterqualityobjectivesaretheresultofastakeholder‐driveneffortledbytheLSJRCommittee,whichisasubcommitteeofCV‐SALTS.TheoutcomeofthisSRSJRBasinPlanamendmenteffortwillguidesaltmanagementintheSanJoaquinRiverwatershed,consistentwiththegoalsoftheSNMPanditsproposedSalinityManagementStrategy.Inaddition,theproposedamendmentprovidesguidanceon:interpretingnarrativeobjectivestoprotectAGR;
24Seefootnote2in:http://www.waterboards.ca.gov/centralvalley/board_decisions/tentative_orders/1608/mun_wkshp/1608_lsjr_wkshp_mtrl.pdf25WaterQualityControlPlanfortheSanFranciscoBay/Sacramento‐SanJoaquinDeltaEstuary,StateWaterResourcesControlBoard,December13,2006.
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Section 4 Central Valley Salt and Nitrate Management Strategy adjustingregulationtoaccountforextendeddryperiods;andmanagingsaltatabasin‐widescale.TheBasinPlanamendmentisexpectedtobeproposedforadoptionin2017.26
4.2.4 Regulatory Evaluations CV‐SALTSconductedseveralregulatoryandliteraturereviewstoevaluatethetechnicalbasisforprotectionofselectedbeneficialuses.Morespecifically,thesestudiesevaluatedwhatconstitutesreasonableprotectionofexistingandprobablefutureusesforprotectionofMUN,AGRandaquaticlife,asrelatedtonitrateand/orsalt.ThespecificevaluationscompletedaresummarizedinthesubsectionsbelowandthecompletefindingsareaccessiblethroughtheTechnicalProjectsIndexlocatedattheCV‐SALTSwebsite;27theyarealsoaccessibleinAttachmentB.1ofthisSNMP.
4.2.4.1 Salinity Effects on MUN‐related Uses of Water
CV‐SALTScompletedresearchtodefinewhatconstitutesreasonableprotectionofexistingandprobablefutureMUNuses.Thiseffortfocusedonanevaluationofthecurrentstateofknowledgeregardingtheeffectsofelevatedsalinityconcentrationsondrinkingwatersupply,includinghumanhealthconcerns,andotherdomesticusesofwatersuchasimpactsofsalinityonresidential,commercialandindustrialwater‐usingdevices.ThisstudyalsoreviewedwaterqualityobjectivesestablishedinotherCaliforniaregions,federalrecommendationsfortheprotectionofwaterusedasadrinkingwatersupplydevelopedbytheUSEPA,MUN‐relatedwaterqualitystandardsadoptedbyotherstates,andguidelinesestablishedbyselectedinternationalentities.Theoutcomewasasummaryofkeyfindingsalongwithsupportingdataandreferences(CDMSmith2016d).
4.2.4.2 Salinity Effects on Agricultural Irrigation Uses
ComparabletoitsevaluationoftheMUNuse,CV‐SALTSevaluatedwhatconstitutesreasonableprotectionofexistingandprobablefutureuseofwaterforagriculturalirrigation.Thisresearchincludedanevaluationofthecurrentstateofknowledgeregardingtheeffectsofelevatedsalinityconcentrationsoncropyields,wetlandplantsandvegetationcommonlyusedforlandscaping.Inaddition,thestudyreviewedwaterqualityobjectivesestablishedinotherCaliforniaregions,federalrecommendationsdevelopedbytheUSEPA,waterqualitystandardsadoptedbyotherstatestoprotectwaterusedforirrigation,andguidelinesestablishedbyselectedinternationalentities.Theoutcomewasasummaryofthekeyfindingsalongwithsupportingdataandreferences(CDMSmith2016c).
4.2.4.3 Stock Watering Protection
TheCentralValleyRegionprotectsstockwateringsuppliesthroughapplicationoftheAGRbeneficialuse.CV‐SALTSconductedresearchtoidentifywaterqualitycriteriathatmaybeusedtoestablishsalinityandnitrate‐relatedwaterqualityobjectivestoprotectstockwateringsuppliesintheCentralValley.Thisstudyconsideredthefollowinginformationsources:(a)waterqualityobjectivesestablishedinotherregionsofCaliforniaorinotherselectedstates;(b)reviewofUSEPArecommendations;(c)universityextensionpublicationsandspecialists;(d)publishedpeer‐reviewedliterature;and(e)selectedinternationalagencies.ThefinalreportprovidedCV‐SALTS
26http://www.waterboards.ca.gov/centralvalley/water_issues/salinity/upstream_salt_boron/index.shtml
27http://www.cvsalinity.org/index.php/committees/technical‐advisory/technical‐projects‐index.html
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Section 4 Central Valley Salt and Nitrate Management Strategy withrecommendationsforprotectionofstockwateringsources(Kennedy/JenksConsultants2013).
4.2.4.4 Aquatic Life Protection
CV‐SALTSimplementedastudytoidentifypotentialwaterqualitycriteriathatcouldbeusedtoestablishsalinity‐relatedwaterqualityobjectivestoprotectaquaticlifeinCentralValleysurfacewaters.Thisstudyresearchedthefollowinginformationsources:(a)recentliteraturereviewsconductedbyselectedstatestoestablishwaterqualitycriteriaforsalinity‐relatedconstituents;(b)peer‐reviewedpublishedliterature;(c)dataandmethodologiesdevelopedbyfederalagencies,includingUSEPAandtheUnitedStatesDepartmentofInterior;(d)recommendationsdevelopedbyselectedinternationalagencies;and(e)anyinformationdevelopedbyotherCaliforniaagencies.ThefinalreportprovidedtechnicalrecommendationsforCV‐SALTSconsideration(Buchwalter2014).
4.2.5 Development of the Technical Foundation CV‐SALTScommissionedanumberoftechnicalstudiesovermanyyearstodevelopbaselineinformationtosupportthisSNMP.ThespecificstudiescompletedineachofthesecategoriesaswellasspecificfindingsareaccessiblethroughtheTechnicalProjectsIndexlocatedattheCV‐SALTSwebsite;28theyarealsoaccessibleinAttachmentBofthisSNMP.Inthesubsectionsbelow,summariesareprovidedforthekeystudiesthathavebeenusedto(a)supportdevelopmentofthepolicies,strategiesandregulatorytoolsdescribedinSection4.2.2aboveandinSections4.3.2(nitratemanagement)and4.3.3(saltmanagement)below;and(b)fulfillthesaltandnitratecharacterizationrequirementsdescribedintheRecycledWaterPolicy,inparticularSection6.b(3)(d),anddiscussedinSection3.
4.2.5.1 Nitrate Management
TosupportthedevelopmentofthisSNMP,CV‐SALTScompletedstudiestoprovidethetechnicalbasisfortheestablishmentofanitratemanagementprogramtoachievetheCentralValley’sshortandlong‐termmanagementgoals.ThefindingsfromthesestudieshavebeencoupledwithexistingregulatoryprogramstomanagewaterqualityandthepolicyrecommendationsofthisSNMPtoprovideafoundationforthedevelopmentoftheNitratePermittingStrategytobeimplementedthroughWDRs/ConditionalWaivers.
ExistingnitratemonitoringandmanagementprogramsincludetheIrrigatedLandsRegulatoryProgram(ILRP),theDairyGeneralOrder,andrelatedRepresentativeMonitoringProgram,andexistingWDRs,someofwhichmayalreadyincluderequirementsforthemanagementofnitrate.TheseprogramsprovidethefoundationuponwhichthenitrateimplementationmeasuresidentifiedthroughCV‐SALTSstudiescanbuildtoachievethegoalsofnitratemanagementfortheCentralValley.Forexample,throughtheILRPtheCentralValleyWaterBoardhasadoptedregulatoryrequirementsfordischargesfromirrigatedlandsthroughissuanceofGeneralWDROrders.Underthisprogram,growersmayjointhird‐partygroups(i.e.,coalitionsofgrowers),whichmaybegeographicorcommodity‐based.WDRsissuedtogrowersthataremembersofathird‐partyalreadyincluderequirementstoimplementbestmanagementpracticeswithrespect
28http://www.cvsalinity.org/index.php/committees/technical‐advisory/technical‐projects‐index.html
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Section 4 Central Valley Salt and Nitrate Management Strategy tonitrogenapplicationsinordertomanagenitrogeninthepermittedarea.Asanotherexample,theCentralValleyWaterBoardalreadyregulatesover1300dairiesthroughaGeneralOrderthat“servesasgeneralwastedischargerequirementsfordischargesofwastefromexistingmilkcowdairiesofallsize.”TheseGeneralOrdersprovidethefoundationuponwhichimplementationoftheSNMPwilloccur.
Nitrate Implementation Measures Study (NIMS)
CV‐SALTSconductedtheNIMStoprovideinputtopolicymakersregardingimplementationmeasurestoreducecurrentambientnitrateconcentrationsingroundwatertoprotectandrestorebeneficialuses,consistentwiththisSNMP’smanagementgoals(CDMSmith2016a).Findingsfromthisstudythatreviewedliteraturesourcesanddevelopedindependentestimatesshowedthatthemanagementofnitratetoachievenitratebalanceandtorestorethebeneficialusewherenitratecurrentlyexceedsthewaterqualityobjectiverepresentsasignificantchallengethatwillrequirebothshort‐termandlong‐termimplementationmeasures. TheNIMSevaluatedrequirementstoachievenitratebalanceusingCV‐SALTSdatadevelopedaspartoftheICMproject(LarryWalkerAssociatesetal.2013).Theanalysisshowedthatthenitrateloadingtotheshallowgroundwaterzonevalley‐widerangesfrom97,500to311,000tonsannually.Between78and86percentofthetotalnitrateloadingoccursintheSouthernCentralValley.Thesefindingsillustratetheamountofnitrateloadingthatwillneedtobecontrolledtoachievenitratebalance.Moreover,thelargelegacynitrateloadinthevadosezone,whichwasnotconsideredinthesefindings,willexacerbatefurthernitratewaterqualityconcerns.
Withregardstomanagedrestoration,Kingetal.(2012)estimatedthattherangeofannualizedremediationcoststopumpandtreatthevolumeofgroundwaterthatexceeds10mg/LintheTulareLakeBasinalonetobe$12to$27.6billion.Thisestimatedidnotincludethepipelineorpumpingcostsfortransportofwaterfromremotelocationstoacentralizedtreatmentfacility.NIMSperformedthesameanalysisforthegroundwaterunderlyingtheCentralValleyfloor–SacramentoRiverValley,SanJoaquinRiverValley,andtheTulareLakeBasin.Again,withoutincludingthecostsforextractionwells,rawandtreatedwaterpipelines(andothernecessaryinfrastructure)andusingthesameunittreatmentcostsandassumptionsasKingetal.(2012),thecostfortreatinggroundwaterthatexceeds10mg/LintheCentralValleywouldrangefrom$36to$81billion.Thecostsformanagedrestorationwouldcertainlybeloweratasmallerscale,e.g.,withinadefinedmanagementzone,butwouldstillbeintherangeoftensofmillionsofdollarsforcapitalcostsandmillionsforannualoperationandmaintenancecosts(CDMSmith2016a,seeTable5‐6).
Inadditiontothefindingsofpotentialsignificantcostsassociatedwithachievingrestoration,NIMSdevelopedanestimateofthetimerequiredtoachievevariouslevelsofrestoration(nitrateconcentrationsatorbelowthe10mg/LMCL)withinaspecificstudyarea,i.e.,theAltaIrrigationDistrict(AID)inKingsCounty.Forexample,underapump,treat,andreinjectscenarioataspecifiedextractionrate,itwasestimatedthatitwouldtakemorethan70yearstoachieve10mg/Lnitrateinthegroundwater;doublingtherateofextractionwouldlowerthistimeframeto37years.Otherscenarioswereevaluated,e.g.,pump,treatandserve,butthetimetorestorationorachievingthe10mg/LMCLfornitratewasstillsignificant(CDMSmith2016a).
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Section 4 Central Valley Salt and Nitrate Management Strategy NIMSestablishedamenuofnitrateimplementationmeasuresornitrateremediationtechnologiesforconsiderationbydischargers.Thesetechnologiesfellintooneoftwocategories:(a)exsitu–groundwaterextractionandtreatmentfollowedbyreinjection,dischargeorpotablereuse;and(b)insitutreatment‐NIMSprovidesacomparisonofthetechnologiesbasedondifferentfactors(e.g.,costs,easeofpermitting,orsecondaryimpacts)andapplicabilityofthetechnologiesunderdifferentconditions(e.g.,existingnitrateconcentrations,systemsizeorcontaminantdepth)(CDMSmith2016a).ThisinformationcanbeusedtosupporteffortstomeetrequirementstoachievenitratebalanceormanagerestorationwherefeasibleintheCentralValleyRegion,consistentwiththisSNMPsnitratemanagementrequirements.
Aggressive Restoration Modeling Scenario
TheNIMSstudysummarizedaboveidentifiedanumberofpotentialnitratemanagementcontrols(e.g.,pump,treat,andserve,orpump,treat,andre‐inject)thatcouldbedeployedintheCentralValleytoimprovewaterquality.TheAIDManagementZoneArchetypeStudy,discussedbelowinSection4.2.5.3,evaluatedanumberofmanagementscenariosandthepotentialbenefitstowaterqualitywithintheAIDarea.TobetterunderstandthetypesofnitratecontrolmeasuresthatwouldbenecessarytomeetSNMPmanagementgoal#3(ImplementManagedAquiferRestorationProgram),amodelingstudy,i.e.,AggressiveRestorationModelingScenario,wascompletedthatlinkedmanagementScenario#3fromtheAIDManagementZoneArchetypeStudy(withspecifiedtargetsforirrigationefficiency,reducednitrogenloading,andartificialrechargechanges)withselectednitratemanagementcontrolsidentifiedbytheNIMSandon‐farmwinterrecharge.ThestudyevaluatedtwoselectedareaswithintheAIDboundary(DinubaandCutler/Orosi)withvaryingnitrateconditions.Wellfieldsweredesignedforeachofthestudyareasandthenmodeledtoobservethedegreetowhichnitratedecreasesinambientgroundwaterwithin10to20years(andaslongas100years)usingdifferentsimulations.Keyfindingsincluded(Luhdorff&ScalmaniniConsultingEngineersandLarryWalkerAssociates2016b):
Atargetedapproachforrestorationworksbetterinsmallergeographicsettingswhere
thereismorecontrolandknowledgeaboutthelocaltransportofwaterandnitratemass. Applyingpump,treat,andreinjectdesignstolargeregionalareasisnotpracticablebecause
therearetoomanyothercomplicationssuchasnon‐pointsources,localrural/urban/domesticpumpingstresses,andlateralinfluxesthatinterferewiththemovementandrestorationofthewaterthatisattemptedwiththepump,treat,andreinjectsystemdesign.
Withregardstouseofon‐farmrechargeasamanagementcontrol:(a)Itisadvantageousforflushingtherootzonewithcleanwater,buttheeffectsoftheincreasedrechargearenotalwaysdiscernibleinthepreciseareaoftherechargeactivityandrechargeeffectsmaybeseendowngradientandmaybeaffectedbynearbypumpingstresses;(b)itaidsintheverticalmovementofcleanwater,butcanalsoresultindisplacementofexistingpoorshallowwaterqualitycausingthiswatertomovedownwardintolowerpartsoftheaquifersystem,sometimesincludingtheproductionzone;and(c)on‐farmrechargeandanyattemptsatenhancednaturalrechargeorartificialrechargearegreatlydependentontheabilityoftheaquifermaterialsandwatertableelevationtoacceptadditionalwater.
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Section 4 Central Valley Salt and Nitrate Management Strategy
Pump,treat,andserveeffortsratherthanpump,treat,andreinjectareanexcellentwaytoprovidecleandrinkingwatertocommunities,butthisapproachdoesnotserveasaparticularlybeneficialtoolforrestoration.Theamountofnitratemassremovedfrommunicipalpumpingisminorcomparedtotheamountofmassenteringthesystemthroughsurfacemassloadingandlateralfluxesonaregionalscale.Mostofthepump,treat,andservewaterisconsumed;therefore,littletreatedwaterreturnstotheaquifersystem,offeringlittleornoreplenishmenttotheaquifer.
RestorationisnotlikelyfeasibleonthescaleoftheCentralValley.Itappearstobeunrealisticevenonthescaleofthearchetypestudyarea,AID,asitwouldlikelytakeontheorderofthousandsofnewwellstopump,treat,andreinjectcleanwaterbackintothesystemwhileinterceptingsurfacemassloadingsbeforetheymigratedownintotheproductionzone.Localizedeffortsinareasthatareofhighpriority(basedonproximitytocommunitiesandexistingambientconditions)maybepotentiallyidealforrestorationactivitiesthatmayincludeon‐farmrecharge,otherartificialrechargeefforts,andpump/treat/reinjectefforts.Evenso,restorationactivitiesmaytakedecadestoresultinsatisfactorydeclinesinimpairedgroundwaterquality,andeventuallytheareasmayreachequilibriumwherethenitratemassenteringthesystemequalsthemassexiting.Therefore,targetedreductionsinnitrateconcentrationsmaystillbedifficulttoachieve.
4.2.5.2 Salt Management
TosupportthedevelopmentofthisCentralValleySNMP,CV‐SALTScompletedaphasedstudytoprovidethetechnicalbasisfortheestablishmentofasaltmanagementprogramtoachievetheCentralValley’smanagementgoals.ThefindingsfromthisworkcoupledwiththepolicyrecommendationsofthisSNMPprovidedafoundationforthedevelopmentoftheSalinityManagementStrategy,aphasedsalinitymanagementprogramtobeimplementedintheCentralValley(seeAttachmentA‐3).
SSALTSdescribedexamplesofongoingeffortstomanagesaltintheCentralValley,whichmaybeusedasarchetypesforhowsaltcouldbemanagedbyotherdischargers(CDMSmith2013).Inaddition,SSALTSidentifiedtherangeofavailableCentralValleyalternativesforsaltmanagement,storageordisposalconsideringin‐valley,out‐of‐valley,orcombinationsofinandout‐of‐valleysolutions(CDMSmith2014).Evaluatedin‐valleysaltmanagement,storage,ordisposalalternativesincludedsourcecontrolBMPs,landmanagement,applicationoftreatmenttechnologies,deepwellinjection,andsupplyforhydraulicfracturing.Out‐of‐valleyalternativesfocusedontwostrategies:(a)oceandisposal,thatprovidesanalternativethatmaybeappliedwhereneededacrosstheCentralValleyRegion;and(b)implementationoftheSanJoaquinRiverReal‐TimeManagementProgramwithintheSanJoaquinRiverwatershed.
SSALTSdemonstratedthatimplementationofin‐valleyalternativescanprovideshort‐termorlocalsolutionstothemanagementortreatmentofsalttoensurelocaldrinkingwatersuppliesarenotimpactedandlocaldegradationisminimizedordoesnotoccur(CDMSmith2014).TheseoutcomesareappropriateinareasoftheCentralValleyRegionwheresalinityingroundwaterisnotasignificantconcern.However,wheresaltaccumulationisasignificantconcern,i.e.,salinityisalreadyelevated,istrendingupwardandhasthepotentialtoimpactthebeneficialuse,orthebeneficialuseisalreadyimpacted.Currentsalinitymanagementactivitiesmayonlyaddress
Section 4 Central Valley Salt and Nitrate Management Strategy
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about15%oftheannualsaltload.Long‐termsolutionsareneededtoaddresstheother85%.Accordingly,implementationof,orparticipationin,along‐termsalinitymanagementprogrambydischargersandotheraffectedentitieswillbenecessary.Wherealong‐termmanagementprogramisnecessary,SSALTSrecommendedthedevelopmentofaCentralValleyregulatedbrinelinetotransportsalttotheoceanfordisposal.Thisfindingisconsistentwithpreviousfindingsintheregionthatidentifiedtheneedfora“valleywidedrain”totransportsaltsoutoftheTulareandSanJoaquinRiverBasins.29
Similartonitrate,thetimeandcosttoachievesaltbalance(sonoadditionaldegradationoccursinareasofconcern),ormanagedrestorationissignificant,especiallywithinareasofthesouthernpartoftheCentralValley.Forexample,thecapitalcosttodesignandconstructaCentralValleyregulatedbrinelinetodischargebrinetoSanFranciscoBaywouldbemorethan$7billionplusanadditional$0.7‐$0.8billion(in2014dollars)tooperateandmaintainthesystem(CDMSmith2014).Thesecostsdonotincludethepipelinesrequiredtocollecteffluentsfortreatment.Oncetreatmentandbrinedisposalsystemsareoperational,treatedwatercouldbesoldtooffsetannualimplementationcosts.Thesecostsweredevelopedbasedonaconceptualapproachtothedevelopmentofabrineline.Costswouldvarydependingonactualoutfalllocation,systemconfigurationandenvironmentalpermittingwhichwillbechallenging.
SSALTSprovidedaconceptuallevelviewofthechallengesthatwillbefacedintheCentralValleytoachievesaltbalanceandultimatelyrestoration,bothwhereitisdeemedreasonableandfeasible.Notonlyaretheresignificantengineeringandpermittingchallengestoidentifiedsolutions,buttherearesignificantfundingandgovernanceissuestobeaddressed(CDMSmith2016b).Withtheseuncertaintiesinmind,CV‐SALTSdevelopedaSalinityManagementStrategythatestablishedaphasedapproachtosaltmanagementwherethefirstphase,expectedtorequireapproximately10‐15yearstocomplete,wouldfocusonaddressingthekeygovernanceandfundingissuesassociatedwithlong‐termsaltmanagement,andconductingtheadditionaltechnicalstudiesneededtofurtherdevelopshort/long‐termsolutionsforsaltmanagementatregionalandsubregionalscales(seeAttachmentA‐3andSection4.3.3below).Thesecondandthirdphaseswouldseekfundingforandimplementthesaltmanagementprogram.
4.2.5.3 Alta Irrigation District Management Zone Archetype
TheSNMPincludesaproposedGroundwaterManagementZonePolicy(AttachmentA‐1)toencouragetheestablishmentofmanagementzonesasarecommendedapproachforregionalmanagementofnitratewithingroundwaterbasins/subbasins.Tofacilitatethedevelopmentofthispolicy,CV‐SALTScommissionedtheManagementZoneArchetypeAnalysis:AltaIrrigationDistrictstudy(LarryWalkerAssociatesetal.2016)toevaluateanumberofissuesthatmightaffectthedevelopmentandimplementationofamanagementzone.
TheconceptualmanagementzoneforthestudywastheAIDwithintheKingsgroundwatersubbasinThestudy,whichwasdevelopedandimplementedinacollaborativesettingwithlocalstakeholders,includingregulatoryandpartneragencies,servedasanexampleand“proofofconcept”tohelptest,onaspatiallyrefinedbasis,theapplicationofselectedpolicies,dataanalysismethods,andsaltandnitratemanagementapproachesunderconsiderationbyCV‐SALTS.Local
29TLBBasinPlan,Pg.IV‐5‐6;SRSJRBasinPlan,Pg.IV‐15.00
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Section 4 Central Valley Salt and Nitrate Management Strategy saltandnitratemanagementgoalsfortheAIDmanagementzonearchetypeweredevelopedbytheAIDstakeholdersearlyintheprojectandwerefocusedonthehighestpriorityissueswithinthearea,includingsupportingsustainablemanagementofsurfacewaterandgroundwatersuppliesandprotectingsurfacewaterandgroundwaterqualityandbeneficialuses.
Thelocalgoalsassistedthestakeholdersinprovidingacontextwithinwhichtotestthevarioussaltandnitratemanagementoptionsand/orpoliciesthatcouldbeestablishedfortheconceptualmanagementzone.AnanalysisoffourmanagementscenarioswasperformedusingtheAIDmanagementzonemodeltoevaluatetheeffectsofvariousstrategiesformanagingsaltandnitrateintheAIDmanagementzone.Threeofthesemanagementscenariosvariedfactorssuchasirrigationefficiency,rechargeandnitrogenloading.Thefindingsfromthesevariousscenariosshowedthatsaltandnitrateconcentrationsdidnotimprovesignificantlyoverdifferenttimeperiods(5,10,20,30,40,5075and100years).Infact,waterqualitydeclinedinsomecasesalegacysaltandnitrateloadsmovedthroughthegroundwater.Afourthmanagementscenariowasevaluatedthatwasmuchmoreaggressiveinitsimplementation.Calledthe“extremescenario”thisscenarioremovedallagricultural‐relatedmassloadingofnitrogenintheAID.Basedonthemodelingresultsfromimplementationofthisscenario,improvementofsimulatednitrateconcentrationsoccurredinallgroundwaterzonesovertime,butatthesametimedegradationofsimulatedTDSconcentrationsoccurred(LarryWalkerAssociatesetal.2016,seeAppendixE).
TheworkperformedundertheAIDstudyprovidedvaluableinformationtoinformthisSNMP.Importantly,thestudydemonstratedthatattainmentofwaterqualityobjectives,i.e.,achievingrestoration,inambientgroundwatermaynotalwaysbepossible,assimilativecapacitymaynotbeavailable,andmanagementphilosophiesmayvaryamongstakeholders.WhilethefindingsfromthestudymaynotnecessarilytranslatetoallareasoftheCentralValley,giventhediversityofgroundwaterconditions,thebasicmethodologyforcharacterizingconditions,performingdataanalysis,developingandusingpredictivemanagementmodels,andthedevelopmentofappropriatemanagementstrategiessuitedtolocalrealitiesmaybecrossapplied.ThesefindingswillprovidesupporttotheimplementationoftheGroundwaterManagementZonePolicyrecommendedunderthisSNMP(seeAttachmentA‐1).
4.2.5.4 Salt and Nitrate Conditions
Section6b(3)(d)oftheRecycledWaterPolicyidentifiesthetechnicalcomponentsrequiredforinclusionintheSNMP:“Saltandnutrientsourceidentification,basin/subbasinassimilativecapacityandloadingestimates,togetherwithfateandtransportofsaltsandnutrients.”CV‐SALTScompletedanumberofstudiestodevelopthisinformationintheCentralValleyandthefindingsfromthesestudiesprovidethefoundationforthenitrateandsaltmanagementsectionsofthisSNMP(Sections4.3.2and4.3.3,respectively).Table4‐3summarizesthestudiesthatprovideinformationoneachRecycledWaterPolicyrequiredcomponentandwherethatinformationissummarizedwithinthisSNMP.AttachmentBofthisSNMPprovideslinkstoadditionalinformationregardingstudiescompletedtofulfilltherequirementsoftheRecycledWaterPolicy.
Section 4 Central Valley Salt and Nitrate Management Strategy
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Table 4‐3. CV‐SALTS Technical Studies Completed to Satisfy Recycled Water Policy SNMP Requirements for the Evaluation of Salt and Nitrate
Required Recycled Water Relevant CV‐SALTS Studies1
Policy Component Salt and nutrient (nitrate)
source identification
Larry Walker Associates et al. 2013. Initial Conceptual Model Final Report:
Task 7 and 8 ‐ Salt and Nitrate Analysis for the Central Valley Floor and a
Focused Analysis of Modesto and Kings Subregions. December 2013.
Larry Walker Associates et al. 2016. Management Zone Archetype
Analysis Report: Alta Irrigation District. July 2016.
CDM Smith. 2016a. Nitrate Implementation Measures Study. March 2016.
CDM Smith 2013 and 2014. SSALTS Final Phase 1 Report: Identification
and Characterization of Existing Salt Accumulation Areas; and Final Phase
2 Report: Development of Potential Salt Management Strategies.
December 2013 and October 2014, respectively.
Basin/subbasin assimilative
capacity
Larry Walker Associates et al. 2013. Initial Conceptual Model Final Report:
Task 7 and 8 ‐ Salt and Nitrate Analysis for the Central Valley Floor and a
Focused Analysis of Modesto and Kings Subregions. December 2013.
Luhdorff & Scalmanini Consulting Engineers and Larry Walker Associates.
2016a. Region 5: Updated Groundwater Quality Analysis and High
Resolution Mapping for Central Valley Salt and Nitrate Management Plan;
July 2016.
Basin/subbasin loading
estimates
Larry Walker Associates et al. 2013. Initial Conceptual Model Final Report:
Task 7 and 8 ‐ Salt and Nitrate Analysis for the Central Valley Floor and a
Focused Analysis of Modesto and Kings Subregions. December 2013.
Fate and transport of salts
and nutrients (nitrate)
Larry Walker Associates et al. 2013. Initial Conceptual Model Final Report:
Task 7 and 8 ‐ Salt and Nitrate Analysis for the Central Valley Floor and a
Focused Analysis of Modesto and Kings Subregions. December 2013.
Implementation measures to
manage salt and nutrient
loading in the basin on a
sustainable basis
CDM Smith. 2016b. SSALTS Final Phase 3 Report: Evaluate Potential Salt
Disposal Alternatives to Identify Acceptable Alternatives for
Implementation. October 2016.
CDM Smith. 2016a. Nitrate Implementation Measures Study. March 2016.
CDM Smith. 2014. SSALTS Final Phase 2 Report: Development of Potential
Salt Management Strategies. October 2014.
CDM Smith 2013. SSALTS Final Phase 1 Report: Identification and
Characterization of Existing Salt Accumulation Areas. December 2013.
Luhdorff & Scalmanini Consulting Engineers and Larry Walker Associates.
2016b. Alta Irrigation District Management Zone: Aggressive Restoration
Alternative Modeling Scenario Results. Technical memorandum prepared
for CV‐SALTS. September 2016.
Larry Walker Associates et al. 2016. Management Zone Archetype
Analysis Report: Alta Irrigation District. July 2016. 1 See Section 7 for complete references; referenced CV‐SALTS studies may be accessed through Attachment B or at: http://www.cvsalinity.org/index.php/committees/technical‐advisory/technical‐projects‐index.html
4‐29
Section 4 Central Valley Salt and Nitrate Management Strategy
4.3 Salt and Nitrate Management Strategy ThissectionrepresentstheCentralValleySNMPstrategytomanagesaltandnitrate.AlldischargerswithanexistingWDR/ConditionalWaiverorthoseseekinganewWDR/ConditionalWaivershallcomplywiththerequirementsestablishedbelowforthemanagementofnitrateandsaltfordischargestogroundwater.
4.3.1 Management Plan Framework ForplanningpurposestosupportdevelopmentofthisSNMPthegroundwaterbasins/subbasins,ascurrentlyestablishedbyDWRfortheCentralValley(DWR2003),serveasthebasicordefaultunitsfortheevaluationofsaltandnitrateintheCentralValleyRegion.SNMPSections3.2and3.3abovesummarizedtheexistingTDSandnitratewaterqualityconditionswithineachofthesebasinsandsubbasins.Section3.3.2.3(seeTable3‐17)providesthedefaultassimilativecapacityforupperorproductionzonesforTDSandnitratetoprotectbeneficialuses.Thesedefaultassimilativecapacityfindingsarebasedonthefollowingthresholds:Nitrate(asN)‐10mg/L;TDS–1,000mg/L(EC1,600µg/L).Absentanyotherinformation,theCentralValleyWaterBoardwillrelyonthewaterqualityfindingspresentedinSection3asthebasisfordevelopingsaltandnitratemanagementrequirementsinWDRs/ConditionalWaivers. Itisrecognizedthatthedefaultvaluesforexistingwaterqualityconditionsorassimilativecapacityappliedtoanentiregroundwaterbasinorsubbasindoesnotconsidervariabilityinsaltandnitrateconcentrationsatthelocal/subregionallevel(e.g.,seegroundwaterbasins/subbasinfiguresinLuhdorff&ScalmaniniConsultingEngineersandLarryWalkerAssociates2016a).Accordingly,thisCentralValleySNMPprovidestheopportunityforanindividualdischarger,dischargerspermittedunderaGeneralOrder,ordischargersthathaveformedamanagementzonetoprovidesupplementalinformationthatsupersedesorreplacesthedefaultrequirementsestablishedbythisSNMP.Therequirementsfordevelopingthedata/informationtosupplementorsupersedethedefaultrequirementsofthisSNMParediscussedbelowinSection4.3.4.
4.3.2 Nitrate Management Nitratemanagementwillbeimplementedasdescribedinthesectionsbelow.AttachmentsA‐1(GroundwaterManagementZonePolicy),A‐2(NitratePermittingStrategy),andA‐4(ExceptionsPolicy)provideadditionalsupportinginformation.
EffortstomanagenitratetomeetthegoalsofthisSNMPwillbeimplementedinWDRsorotherappropriateBoardordersthatmustimplementrelevantprovisionsoftheBasinPlans,orConditionalWaivers,whichmustbeconsistentwiththeBasinPlans.30Withrespecttonitrate(ascurrentlyimplementedundertheBasinPlans),WDRs/ConditionalWaiversmustensurethatthatthereceivingwaterwillmeetthewaterqualityobjective,orthatthedischargewillnotcauseorcontributetoanexceedanceofanapplicablewaterqualityobjective.Inaddition,theissuanceofWDRs/ConditionalWaiversmustalsobeconsistentwithrelevantstateandregionalpolicies.InsomeareasoftheCentralValley,andforsometypesofdischargers,thetraditionalpermittingapproachfornitratesmaynotbefeasible,reasonableorpracticable.ThisSNMPsetsforththe
30WaterCode§13263&13269
Section 4 Central Valley Salt and Nitrate Management Strategy
4‐30
nitratemanagementapproachmovingforward,consistentwiththerecommendationscontainedwithinthepoliciesandguidanceprovidedinAttachmentA.
4.3.2.1 Overview of the Nitrate Permitting Strategy
Permitting Pathways
TheSNMPimplementationapproachforpermittingnitratedischargestogroundwaterisseparatedintotwopaths:
PathAdescribestheproposedapproachwhenanindividualdischarger(orthirdparty
groupsubjecttoaGeneralOrderwishingtoproceedunderPathA)decidestocomplywiththenitratecomponentsoftheSNMPasanIndividual/ThirdParty,orwherethereisnomanagementzone.ThispathwayfollowsmorecloselywiththeCentralValleyWaterBoard’straditionalpermittingapproach,withsomeadditionalflexibility.
PathBdescribestheproposedapproachwhenanindividualintendstoparticipateinamanagementzoneinordertocomplywiththenitratecomponentsoftheSNMP.TheSNMPencouragesdischargerstoparticipateinmanagementzonesasthepreferredmethodforcomplyingwiththenitratecomponentsoftheSNMP.However,participationinamanagementzonemaynotbeappropriateforeverydischarger,orgroupsofdischargers,dependingonlocalwaterqualityandvariousdischargerrelatedcircumstances.
Notably,forthosedischargersintendingtocomplyviaPathA,assimilativecapacitymaybegrantedbytheCentralValleyWaterBoardsubjecttorequiredfindings,butassimilativecapacitymustbeavailableinshallowgroundwater31(seeSection4.3.2.3belowfordiscussionregardingassimilativecapacity),withsomelimitedexceptions.Incontrast,fordischargersintendingtocomplybyparticipatinginamanagementzone(i.e.,PathB),assimilativecapacitymaybegrantedbytheCentralValleyWaterBoard(againsubjecttorequiredfindings).InthiscaseitisrecommendedthattheCentralValleyWaterBoardevaluatetheavailabilityofassimilativecapacityusingavolume‐weightedaverageintheupperzone.
Early Action Plans (EAP)
RegardlessofwhetheradischargerchoosesPathAorB,alldischargersmustassessnitratelevelsingroundwaterusedforMUNthatmaybeimpactedbynitrateintheirdischarge(s)toensureitisasafe,reliablesourceofdrinkingwaterwithrespecttonitrates.Ifimpacted,andwherethedischargeriscausingorcontributingtoanexceedanceofnitrateinthegroundwater,thenthedischargershallsubmitanEAPthatincludesspecificactionsandascheduleofimplementationtoaddresstheimmediateneedsofthosedrinkinggroundwaterfrompublicwatersupplyordomesticwellsthatexceedthedrinkingwaterstandardfornitrate.ThetimingofthesubmittaloftheEAPdependsonwhetheradischargercomplieswiththisSNMPasanindividualdischarger(PathA)oraspartofamanagementzone(PathB).
31Theshallowestportionwithintheupperzone(e.g.,uppermost10%oftheupperzone)andwheregroundwaterwouldbeconsideredtoconstituteanaquifer(whichisdefinedasa“bodyofrockorsedimentthatissufficientlyporousandpermeabletostore,transmit,andyieldsignificantoreconomicquantitiesofgroundwatertowellsandsprings”[DWR,2003]).Inallcases,relevantgroundwaterdoesnotincludeperchedwater.
Section 4 Central Valley Salt and Nitrate Management Strategy
4‐31
Prioritization of Implementation
ConsideringthesizeoftheCentralValleyRegion,andthevaryingdegreeofnitrateconcentrationsfoundingroundwaterbasins/subbasinsthroughouttheregion,itisimpracticalandunreasonabletoexpectthatthenitratemanagementrequirementswillbeimplementedbyeveryone,everywhere,atthesametime.Rather,itisappropriateforthisSNMPtorecommendaninitialpriorityrankingofgroundwatersubbasinsandtimescheduleforimplementationofthenitratemanagementrequirements.TherecommendedprocessalsoprovidestheCentralValleyWaterBoardthediscretiontoconsiderwaterquality‐basedfactors,andotherrelevantinformation,toadjustitsdeterminationofareasthatshouldbeprioritizedfirstforimplementationofthenitraterequirementsand/oridentifyareasthatwouldbeconsideredlowerpriority.Ingeneral,theprocessisdescribedasfollows:
Step1–Thisstepidentifiedspatiallyhigherpriorityareasatbothonesquaremilegridandaggregatelevel(groundwaterbasin/subbasin)scales.Theidentificationofhigherpriorityareasreliedontheuseofambientnitratewaterqualitydatafortheupperzoneingroundwaterbasins/subbasins.Notably,theidentificationofpriorityareasbasedonavailablewaterqualitydataandatthislargeofascalemaynotaccuratelyportraywhichareasinabasin/subbasinaretrulyatriskfornitratecontaminationindrinkingwater.Therefore,itisappropriatefortheCentralValleyWaterBoardtohavediscretiontoadjusttheinitialfindingsbasedonadditionalfactors/criteriaandinformation.
Step2–Torevisetheinitialwaterquality‐basedprioritizationinStep1forthegroundwaterbasin/subbasins,theCentralValleyWaterBoardhasthediscretiontoconsideradditionalinformationandfactorswhenidentifyingpriorityareasforimplementationofnitraterequirements.Thisdiscretionincludesidentifyingpriorityareasthataresmallerportionsofalargergroundwaterbasin/subbasinidentifiedinStep1,or re‐prioritizingallorpartsofalargerbasin/subbasin.Theadditionalfactorsinclude,butarenotlimitedto:(a)considerationofthewaterqualitydatathatwasreliedonandthattriggeredthepriorityrankingintheSNMP;(b)ifmorerecentdataand/orinformationareavailableorhasbeenprovidedthatbetterindicatesifthearea(orasubarea)inquestionisatriskfornitratecontaminationindrinkingwatersupplies;(c)ifgroundwateristhepredominatesourceofdrinkingwaterorifsurfacewatersuppliesarethemajorsourceofdrinkingwater;and(d)thedirectimpactonconsumers.
TheSNMPrecommendsthatimplementationbeginonthefirsttierofprioritygroundwaterbasins/subbasinswithinoneyearoftheeffectivedateoftheBasinPlanamendmentsadoptedtoimplementthisSNMPandwithintwotofouryearsoftheeffectivedateforthesecondtierprioritygroundwaterbasins/subbasins.AreasnotprioritizedwithinthefirsttwotierswillstillneedtocomplywiththeSNMPnitraterequirementsinthefuture,butimplementationofsuchrequirementsshallbephasedinbytheCentralValleyWaterBoardasresourcesallow.
Basedonthisgeneralprioritizationframeworkdescribedabove,followingisadditionalinformationregardinghowtheSNMPhasinitiallyidentifiedhigherpriorityareasforSNMPimplementation(Step1),andthefactorsandtimingforsubmittalofadditionalinformationthatmaybeconsideredunderStep2toadjusttheprioritizedlistandscheduleofareastargetedforimplementation.
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Section 4 Central Valley Salt and Nitrate Management Strategy
Step1‐InitialPrioritizationUsingWaterQualityDataTocompletetheinitialprioritizationofgroundwaterbasins/subbasins,theSNMPreliedontheuseof2000‐2016nitrateconcentrationdatafromwellscompletedintheupperzone(Luhdorff&ScalmaniniConsultingEngineersandLarryWalkerAssociates2016a)(SeeSection3.3).Wherenowelldatawereavailable,nitrateconcentrationswereinterpolatedfromnearbyareas.Estimatednitrateconcentrationvaluesintheupperzonewereassessedatonesquaremilegridandgroundwaterbasin/subbasinscalesusingthemethodologydescribedinSNMPAttachmentD‐4.Table4‐4belowliststheresultingInitialPrioritizationScoresfortheCentralValleyfloorgroundwaterbasins/subbasins.Basedonthesescores,CV‐SALTSdevelopedarecommendationforwhichbasins/subbasinsshouldbeprioritizedasPriority1and2–thefirsttwotiersrecommendedforimplementation(Table4‐4).
Step2–AdditionalAnalysisTheCentralValleySNMPrecommendsthattheCentralValleyWaterBoardhavethediscretiontoconsideradditionalfactorsandinformationtoadjusttheprioritizedbasins/subbasins,orpartsofthereof,andscheduleforimplementingthenitraterequirementsinthoseprioritizedareas.Inexercisingthisdiscretion,theCentralValleyWaterBoardmayconductthisadditionalanalysisunderitsowninitiative,oruponreceivinginformationrelativetothefactorsidentifiedbelowbyanyinterestedpersons.Further,theCV‐SALTSExecutiveCommitteemaycontinuetoevaluateadditionaldataandinformationbasedonthefactorsidentifiedbelow,andmayprovidetheCentralValleyWaterBoardwithanupdatedrecommendationforprioritizationinthefuture.Anysuchrecommendationorrequestforre‐prioritizationfromtheCV‐SALTSExecutiveCommitteeoranyinterestedpersons,needstobeprovidedtotheCentralValleyWaterBoardpriortothecloseofanypubliccommentperiodrelatedtheCentralValleyWaterBoard’sadoptionofBasinPlanamendmentstoimplementtheSNMP.Theadditionalfactorsincludebutarenotlimitedto:
(a)Degreetowhichareas(orsubareas)withknowndrinkingwatersupplycontaminationingroundwaterintheupperzoneingroundwaterbasins/subbasinswillbeaddressedinatimelymannerthroughthecurrentorderofprioritybasedonwaterqualityfactorsalone(Table4‐4).
(b)Additionaldata/informationprovidedbydischarger(s)and/orotherstakeholderswithinabasin/subbasin(orsubarea)thatdemonstratesthatthenitrateconcernsasidentifiedinTables4‐4havebeenaddressedorwillbeaddressedviaanotherprogramoractivity.
(c)Additionaldata/informationprovidedbydischarger(s)and/orotherstakeholderswithinabasin/subbasin(orsubarea)thatdemonstratesthattherankinginTable4‐4isnotrepresentativeofgroundwaterdrinkingwaterconditionsandthatthebasin/subbasin(orsubarea)doesnotneedtobeprioritizedbecausetherearenotconcernsorrisksfornitratecontaminationtobefoundingroundwaterreliedonfordrinkingwaterpurposes.
(d)Degreetowhichtheareaidentifiedasahigherprioritybywaterqualityfactorsactuallyhasimpacteddrinkingwaterusers(i.e.,drinkingwaterispredominatelyasurfacewatersupply,ordrinkingwatersuppliesareprimarilygroundwater).
(e)Changesingroundwaterbasin/subbasinboundariesbyDWR,whichmayaffectthespatial
orderaspresentedinTable4‐4.
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Section 4 Central Valley Salt and Nitrate Management Strategy
Table 4‐4. Ranking and Priority for Groundwater Basins/Subbasins Based on Step 1 of Prioritization Process Using Ambient Nitrate Concentrations in the Upper Zone (see text)1
2 Groundwater Basin/Subbasin (DWR Bulletin 118) Initial Prioritization
Priority Number Name 3
Score
Priority 1
5‐22.11 Kaweah 5.35
5‐22.03 Turlock 4.27
5‐22.05 Chowchilla 3.78
5‐22.13 Tule 3.48
5‐22.02 Modesto 3.09
5‐22.08 Kings 3.02
Priority 2
5‐21.67 Yolo 2.89 5‐22.04 Merced 2.76
5‐22.14 Kern County (Westside South) 2.70
5‐22.12 Tulare Lake 2.44
5‐22.14 Kern County (Poso) 2.37
5‐22.07 Delta‐Mendota 2.13
5‐22.01 Eastern San Joaquin 1.98
5‐22.06 Madera 1.93
Not Prioritized by
SNMP4
2‐4 Pittsburg Plain 1.70 5‐21.66 Solano 1.37
5‐22.15 Tracy 1.35
2‐3 Suisun‐Fairfield Valley 1.34
5‐21.52 Colusa 1.26
5‐22.14 Kern County (Kern River) 1.21
5‐21.61 South Yuba 1.03
5‐21.64 North American 0.93
5‐21.57 Vina 0.92
5‐22.16 Cosumnes 0.87
5‐21.58 West Butte 0.83
5‐21.68 Capay Valley 0.80
5‐21.62 Sutter 0.71
5‐21.56 Los Molinos 0.70
5‐22.10 Pleasant Valley 0.64
5‐21.60 North Yuba 0.63
5‐21.65 South American 0.53
5‐21.54 Antelope 0.49
5‐21.59 East Butte 0.48
5‐21.51 Corning 0.45
5‐21.50 Red Bluff 0.27
5‐21.55 Dye Creek 0.25
5‐22.09 Westside 0.18
5‐21.53 Bend 0.18
5‐6.04 Enterprise 0.10
5‐6.03 Anderson 0.08
5‐6.01 Bowman 0.04
5‐6.06 South Battle Creek 0.00
5‐6.05 Millville 0.00
5‐6.02 Rosewood 0.00 1 Water quality data source: Luhdorff and Scalmanini Consulting Engineers and Larry Walker Associates (2016a) 2 The Kern County subbasin is split into three parts to be consistent with the Tulare Lake Basin Plan 3 See SNMP Attachment D‐4 for additional information regarding use of water quality data to develop Initial Prioritization Scores 4 Areas not prioritized in Priority 1 or 2 will still need to comply with the SNMP nitrate requirements in the future, but
implementation of such requirements shall be phased in by the Central Valley Water Board as resources allow
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Section 4 Central Valley Salt and Nitrate Management Strategy
(f) Maximizingefficientuseofresources,whichmayaffectthenumberofbasins/subbasins(orsubareas)thatmaybeincludedontheCentralValleyWaterBoard’slistofprioritizedareas,anditsscheduleofimplementation.
TheCV‐SALTSdatabaseisthesourceofthedatausedtoestablishtheinitialprioritizationscore(Luhdorff&ScalmaniniConsultingEngineersandLarryWalkerAssociates2014).ThisdatabaseincludesdatafromallwelltypesintheCentralValleyRegion,includingthoseusedforremediationmonitoring.Assuch,acloserexaminationofthedatausedtoestimateambientnitrateconcentrationsintheupperzonemay,insomecases,bewarrantedunderStep2,butwithintheschedulerequiredformakingrecommendedchangestotheinitialprioritization(seediscussionabove).Thispotentialneedforconsiderationofadditionaldata/informationisaddressedbyfactors(b)and(c)aboveandillustratedbyanexampleinSNMPAttachmentD‐4.
RegardlessofthepriorityforimplementationandscheduleestablishedbytheCentralValleyWaterBoard,nothingpreventsadischargerorgroupofdischargersfromimplementingthenitratemanagementrequirementsintheSNMPpriortoreceivinganoticetocomply,orpreventstheCentralValleyWaterBoardfromre‐prioritizingareasinthefuturebasedonnewdataandinformation.
Management Zones
TheCentralValleySNMPrecommendsandencouragestheestablishmentofmanagementzonesfornitrateasanoptionforgroundwaterqualitymanagementatthelocalorsubregionallevel,especiallywithintheCentralValleyfloor.Figure4‐1summarizesthecharacteristicsofamanagementzone.Theestablishmentofamanagementzone,asadiscreteregulatorycomplianceunitfornitrateforthepurposesofcomplyingwiththeCentralValleyRegion’sSNMP,ismostappropriateinareaswheretheinteractionsamonglanduse,waterqualityandwaterusersarecomplexandsignificantconcernsexistwithmeetingthenitratewaterqualityobjectivesestablishedtoprotecttheMUNbeneficialusesingroundwater.Inareaswherethesecomplexitiesorwaterqualityconcernsdonotexist,establishmentofamanagementzonemaynotbethebestapproachformanagingdischargestogroundwater.Thismaybeparticularlytruefordischargerslocatedinareaswhereexistingnitratewaterqualityisgood,individualsandcommunitywatersystemsarenotimpacted,andlong‐termwaterqualitytrendsarenotaconcern.Similarly,establishmentofamanagementzonemaynotbeappropriateoutsideoftheCentralValleyfloorinthesurroundingfoothillsandvalleys.Inanyofthesesituations,compliancewiththenitratemanagementrequirementsofthisSNMPmaybebestaccomplishedthroughexistingwaterqualitymanagementprogramsimplementedthroughindividualWDRs/ConditionalWaiversor,insomecases,throughcoordinationwithlocalagenciestoenforcesourcewaterprotectionrequirements.
Section 4 Central Valley Salt and Nitrate Management Strategy
4‐35
Figure 4‐1. Characteristics of a Management Zone
A defined area which incorporates a portion of a larger groundwater basin(s)/subbasin(s) that serves
as a discrete regulatory compliance unit for compliance with the nitrate components of the Central
Valley SNMP;
Intended to include all of the groundwater and all of the regulated dischargers that discharge nitrate
and that choose to participate in the management zone within the land area encompassed by the
management zone boundary.
Intended, where nitrates in groundwater are impacting groundwater being used as a drinking water
supply, to facilitate the assurance of safe drinking water for all residents in an area adversely affected
by dischargers participating in the management zone, encourage stakeholder coordination and
cooperation, promote better water resource management through appropriate allocation of
resources, and provide greater regulatory flexibility where needed to prioritize nitrate management
activities and allow time to achieve compliance with the Central Valley SNMP’s nitrate management
goals.
The basis for the establishment of local management plans to manage nitrate within the
management zone’s boundary in accordance with the Central Valley Region’s overall nitrate
management goals established in the Central Valley SNMP.
Voluntarily proposed by those regulated dischargers located within the proposed management zone
boundary that have decided to work collectively and collaboratively to comply with the nitrate
management requirements of the Central Valley SNMP.
1 Dischargers within a management zone boundary that choose not to participate in the management zone, they must be able to provide assurance to the Central Valley Water Board that they are addressing any adverse effects directly or indirectly associated with their discharge.
4.3.2.2 Permitting Pathways
Figure4‐2illustratestheinitialactivitiesthatoccuruponimplementationofthenitratemanagementrequirementsofthisSNMPwithinaprioritizedarea(seeTable4‐4).WhenthedischargerswithinaprioritizedareaarenotifiedthattheymustcomplywiththisSNMP(i.e.,asdeterminedbytheprioritizationprovidedinTable4‐4),thedischargerswithinthepriorityareawillneedtodeterminewithinasetperiodoftimewhethertheyplantocomplyasanindividualdischarger(PathA)oraspartofamanagementzone(PathB).32Duringthisformulationperiod,dischargersinterestedinformingamanagementzone(oraleadentityonbehalfofdischargers)shouldworkcollectivelytodevelopaPreliminaryManagementZoneProposalthatincludestheelementssummarizedinFigure4‐3.Thetimelineforpreparationofthisproposalisasfollows:
32Forpurposesofthisnotification,individualdischargersthataresubjecttoGeneralOrdersthatcoveraspecifiedgeographicareaorarecommoditybased,andthatareadministeredbyaThirdParty(e.g.,ThirdPartyOrdersforIrrigatedAgriculture),theThirdPartymayprovidenoticeasrequiredinthissteponbehalfofitsmembers.ForindividualdischargersthataresubjecttoaGeneralOrderthatisnotadministeredbyaThirdParty(e.g.,DairyGeneralOrder),theindividualmustprovidethenecessarynoticeasindicatedinthisstep.
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Section 4 Central Valley Salt and Nitrate Management Strategy
FordischargerswithinPriorityArea1(seeTable4‐4),aPreliminaryManagementZoneProposalshallbesubmittedwithin270daysofthereceivinganotificationtocomplywiththenitratemanagementrequirementsofthisSNMP.Tosupportthisdeadline,CentralValleyWaterBoardshallprovidenoticetoPriority1dischargersinadvanceoftheBasinPlanamendmentsbecomingeffective.
FordischargersinPriority2,aPreliminaryManagementZoneProposalshallbeduewithinone(1)yearfromthenotificationprovidedbytheCentralValleyWaterBoard.
AreasnotprioritizedwithinPriorityAreas1or2willstillneedtocomplywiththeSNMPnitraterequirementsinthefuture,butimplementationofsuchrequirementsshallbephasedinbytheCentralValleyWaterBoardasresourcesallow.
Regardlessofthepriority,theExecutiveOfficeroftheCentralValleyWaterBoardshallretaindiscretiontoextendthetimelinesforsubmittalofaPreliminaryManagementZoneProposalifproperjustificationisprovidedtotheExecutiveOfficeratleast30dayspriortothedeadlineforsubmittingtheproposal.Similarly,theCentralValleyWaterBoardmayadjustthepriorityofanareabasedonupdatedinformation.
Figure 4‐2. Initial SNMP Nitrate Management
Actions
ThepurposeforpreparingaPreliminaryManagementZoneProposalistoprovidealldischargerswithinthespecifiedpriorityareaforadevelopingmanagementzonewithenoughinformationtomakeanelectionforcomplyingwiththenitratecomponentsoftheSNMPviaPathA(asanindividualdischarger/thirdpartygroup)orviaPathB(participantinamanagementzone).Afterconductingtheirowninitialassessmentoftheirdischarge,andafterevaluatinganyapplicablePreliminaryManagementZoneProposals,dischargerswillthenneedtonotifytheCentralValleyWaterBoardoftheirelectionofPathAorPathB.TheSNMPrecommendsthatthenotificationbemadeintheformofaNoticeofIntent(NOI).ThefollowingsectionsbelowdescribethenextstepsthatshallbeimplementedbasedontheselectionofPathAorB.
Path A ‐ Individual Dischargers or Third Party Group Subject to General Order
Figure4‐4illustratesthestepstocomplywithPathAbeginningwiththeNOIsubmittalrequirements.DevelopingpermitrequirementsunderPathAdependsontheimpactoftheindividualdischargertotheunderlyinggroundwater–measuredinshallowgroundwater.Thelevelofeffortandtheconditions/requirementsimposedbytheCentralValleyWaterBoardinpermittingnitratedischargeswillvarydependingontheimpacttowaterquality.
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Section 4 Central Valley Salt and Nitrate Management Strategy TheSNMPrecognizesthatsomedischargesofnitratestogroundwaterwouldbeconsideredlow‐threat,andarethereforerelativelysimplefortheCentralValleyWaterBoardtoauthorizeinexistingWDRs,orrenewed/revisedWDRs.Specifically,
Dischargesthatarebetterthanreceivingwaterqualityandthereceivingwaterisbetterthanthewaterqualityobjectiveof10mg/Lareconsideredtonotlowerwaterquality.Insuchcircumstances,thedischargeisnotsubjecttothestate’santidegradationpoliciesandtheCentralValleyWaterBoardisnotrequiredtomakethefindingsasspecifiedinResolution68‐16toauthorizethedischarge.
Figure 4‐3. Elements of Preliminary Management Zone Proposal
Proposed preliminary boundary areas;
Identification of initial participants/dischargers;
Identification of other dischargers and stakeholders in the management zone area that the initiating group
is in contact with regarding participation in the management zone;
Identification of process for coordinating with other non‐dischargers to address nitrate‐related drinking
water issues, which must include consideration of coordinating with affected communities, domestic well
users and their representatives, the State Water Board’s Division of Drinking Water, Local County Health
Officials, Sustainable Groundwater Management Agencies and others as appropriate;
Initial identification of public supply wells, and/or domestic wells that exceed the drinking water standard
for nitrate;
An EAP that includes specific actions and a schedule of implementation to address immediate drinking
water needs of those initially identified within the management zone boundary whose drinking
groundwater exceeds nitrate standards;
Initial assessment of groundwater conditions based on existing data and information for each basin or
subbasin covered by the management zone;
Identified constituents of concern the group intends to address with the management zone besides
nitrates (the group has the option to consider other constituents of concern, but is not required to do so);
Proposed timeline for:
o Identifying additional participants;
o Further defining boundary areas;
o Developing proposed governance and funding structure;
o Additional evaluation of groundwater conditions across the management zone boundary area, if
necessary;
o Identification of regulatory compliance pathway for participating dischargers (i.e., intend to request
approval of use of assimilative capacity that may be available on a volume‐weighted basis in the upper
zone, or need for obtaining an approved exception from meeting the nitrate water quality objective
for protection of the MUN beneficial use); and
o Preparing and submitting a Final Management Zone Proposal and a Management Zone
Implementation Plan.
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Section 4 Central Valley Salt and Nitrate Management Strategy
Somedischargersmaybeabletodemonstratethattheirdischarge,orcollectivedischarges,arelowthreatinnaturebecausetheyhavedataandinformationthatdemonstratesthatthedischargeshavenotdegradedgroundwateroveraspecifiedtime‐period,andthatthenatureofthedischargehasremainedconstant.Forexample,insomeareasoftheCentralValleywheregroundwaterisbetterthanthenitratewaterqualityobjective,andcroppingandculturalpracticeshaveremainedconstant,dataandinformationmaybeusedtodemonstratethelowthreatnatureofthedischarge.
Incontrast,theremaybedischargesofnitratesthatareabovethedrinkingwaterstandardandthereisnoavailableassimilativecapacity.Inthesecircumstances,itmaybeappropriatefortheCentralValleyWaterBoardtograntanexceptiontomeetingthewaterqualityobjectiveratherthanprohibitingthedischarge(seeSection4.3.2.4belowandtheExceptionsPolicyinAttachmentA‐4).Alternatively,afindingmaybemadethatthedischargewilldegradewaterqualityandanallocationofassimilativecapacityisrequired.Becauseofthevariouslevelsofimpactsthatmayresultfrom thedischarge,33this SNMPestablishesfive categoriesfordischargerschoosingtocomplywiththeSNMPviaPathA.Table4‐5defineseachofthesecategories.
Asnotedabove,Figure4‐4providesasummaryofthePathAstepstodemonstratecompliancewiththenitratemanagementrequirementsofthisSNMP.Step1intheprocessissubmittaloftheNOIwhichshallinclude:
Figure 4‐4. Path A Steps to Compliance with SNMP
Aninitialassessmentofreceivingwaterand/ordischargeconditions.
Fortraditionalpointsources,aninitialassessmenttodetermineifthedischargeisimpactinganynearbypublicwatersupplywellsordomesticwellsfornitratesbasedonallreadilyavailabledataandinformation;fornon‐pointsources,identificationofareaswherethereare“hotspots”withrespecttonitrateconcentrationsingroundwaterbasedonallreadilyavailabledataandinformation.
Asapplicable,anEAPthatincludesspecificactionsandascheduleofimplementationtoaddressimmediateneedsofthosedrinkinggroundwaterthatexceedsthedrinkingwaterstandardiftherearepublicwatersupplyordomesticwellsimpactedbynitratesfrom
33Dischargeasusedhereisintendedtomeanthequalityofthedischargeasitentersfirstencounteredgroundwater.Thus,thequalityofthedischargeitselfmayexceedthestandardbutduetotransformationandothervariables,itmeetsorisbetterthantheobjectiveasitentersfirstencounteredgroundwater.
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Section 4 Central Valley Salt and Nitrate Management Strategy
dischargescoveredbytheNOI.ItisanticipatedthatdischargesinCategories1through3willnotneedanEAPbecausesuchdischargesarearguablynotcausingorcontributingtoanexceedanceofthenitratedrinkingwaterstandard.Dischargesincategories4and5mayneedtoprepareanEAP,whichmaybepartofaproposedACP.AnEAPisjustthat,anidentificationofearlyactions.TheEAPmaynotbecomprehensive,andmayneedtoberevisedandsupplementedwithadditionalinformationaspartoftheACPthatisincorporateddirectlyintotheWDRs.
IdentificationofCategoryoftheDischarge(seeTable4‐5).
Informationnecessarytosupportallocationofassimilativecapacity,asapplicable(see4.3.2.3below).
ApplicationforExceptionpursuanttotheExceptionsPolicy,asapplicable(seeSection4.3.2.4belowandAttachmentA‐4).
Ifthedischarger(s)isinanareathatiscoveredbyaPreliminaryManagementZoneProposal,andthedischarger(s)isseekinganallocationofassimilativecapacityunderPathA,thedischarger(s)mustshowhowallocationofassimilativecapacitytotheindividualdischargerwillimpact(ornot)availableassimilativecapacityforthoseparticipatinginthemanagementzone.
UnderStep2(Figure4‐4),iftheNOIincludesanEAPtoaddressimmediatedrinkingwaterneeds,theCentralValleyWaterBoardwillnotifythedischargerwithin30daysifthedischargermayproceedwithimplementingtheEAP.IfnoEAPwassubmittedaspartoftheNOI,thisPathAstepisnotapplicabletothedischarger. BasedontheinformationintheNOIsubmittedinStep1,underStep3(Figure4‐4)theCentralValleyWaterBoardshalldetermineifthedischargercancomplywiththeSNMPwithnofurtheraction,orifthedischargerwillberequiredtosubmitadditionalinformationand/orifadditionalWDRconditionsarenecessaryforthedischargertocomplywiththeSNMPfornitrates.Ingeneral,perTable4‐5:
Categories1and2–ThesedischargeswillbedeterminedtocomplywiththeSNMPfornitrateswithouttheneedforfurtherconditionsorrequirements.
Category3‐TheCentralValleyWaterBoardmustmakefindingsthatareconsistentwiththe
State’sAntidegradationPolicy(ResolutionNo.68‐16).Dependingonthelevelofdegradation,theCentralValleyWaterBoardmayrequireadditionalconditionsinWDRstoimplementtheSNMP,andtoallocateassimilativecapacity,whichinthecaseofCategory3,mayconsistofadditionalmonitoringandtrendevaluations.
Categories4and5‐ToreceiveCentralValleyWaterBoardapprovalfortheallocationofassimilativecapacityorapprovalofanexceptionpursuanttotheExceptionsPolicy(seeSection4.3.2.4belowandAttachmentA‐4),thedischargerwillneedtoproposeanACPforCategories4and5aspartoftheNOI,oraccordingtoadateotherwiseagreedtobytheExecutiveOfficer.
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Section 4 Central Valley Salt and Nitrate Management Strategy
TomakefindingsofcompliancewiththenitratecomponentsoftheSNMP,theCentralValleyWaterBoardmustmakethefindingsand/orimposetheconditionsapplicabletoeachindividualcategory,assummarizedinTable4‐6.Thefindingsand/orconditionsshallbeincludedinanew/revisedWDR.
Table 4‐5. Discharge Categories Applicable to Path A.
Discharge Category Central Valley Water Board Findings/Conditions
Category 1 ‐ No Degradation Category
Discharge1 is equal to or less than the water quality objective of 10 mg/L, and the discharge is better than baseline receiving water quality.
Category 2 ‐ De minimus
Category
Baseline receiving water has available assimilative capacity (i.e., is better than the water quality objective). For this category, the discharge(s) may be above the water quality objective as it enters the receiving water, but the discharge(s) will use less than 10% of the available assimilative capacity over a 20‐year period and will not cause the receiving water to exceed a trigger of 7.5 mg/L in that time period. This would be considered a de minimus discharge.
Category 3 ‐ Degradation Below 75% of the Water Quality Objective Category
Discharges will be considered as part of this category if the discharge occurs in a basin where concentrations in the volume‐weighted upper zone do not exceed an acceptable annual increase2 and the discharger(s) anticipate using available assimilative capacity in baseline receiving water that is considered to be more than de minimus but will not cause the receiving water to exceed a trigger of 75% of the water quality objective for nitrate over a 20‐year planning horizon. To allow use of assimilative capacity in this circumstance, the Central Valley Water Board may find it necessary to include additional monitoring and trend evaluations as part of the WDRs in order to make appropriate findings consistent with Resolution 68‐16 and the SNMP.
Category 4 ‐ Degradation Above 75% of the Water Quality Objective Category, or Receiving Water Quality is at 50% of the water quality objective and the Discharge(s) Occur in a Basin where Concentrations in the Volume‐ weighted Average of the Upper Zone Exceeds the Acceptable Annual Increase.2
Discharges will be considered as part of this category if they anticipate using available assimilative capacity in the receiving water, and use of assimilative capacity will cause the receiving water to exceed the trigger of 75% of the water quality objective for nitrate over a 20‐year planning horizon, or the receiving water is already at 50% of the water quality objective and the discharge(s) occur in a basin where the volume‐ weighted average of the upper zone exceeds an acceptable annual increase in concentration.2 To allow use of assimilative capacity in this circumstance, the discharger must submit a proposed ACP to the Central Valley Water Board to be included as an additional condition in the WDRs in order to make appropriate findings consistent with Resolution 68‐16 and the SNMP3
Category 5 ‐ Discharge Above Objective and No Available Assimilative Capacity
Discharges that exceed the water quality objective for nitrate, and where the receiving water has no available assimilative capacity, will be considered to be part of this category. Discharges in this category will need to seek an exception pursuant to the Exceptions Policy under the SNMP. or the discharge may be prohibited
1 Discharge as used here is intended to mean the quality of the discharge as it enters first encountered groundwater. Thus, the quality of the discharge itself may exceed the standard but due to transformation and other variables, it meets or is better than the objective as it enters first encountered groundwater. 2 Acceptable annual increase: Upper zone concentrations do not increase more than 0.1 mg/L NO3‐N per year using cumulative average annual increase over a five‐year period. The cumulative average refers to an Olympic average, meaning that the highest and lowest sample results are removed; average is calculated from the remaining results. This helps address statistical outliers that otherwise may skew the results. 3 It is expected that an ACP will be required by the Central Valley Water Board if they agree to authorize use of assimilative capacity for dischargers that fall within Category 4 as an ACP will be an essential element of their ability to make the necessary findings pursuant to Resolution 68‐16. However, the Central Valley Water Board maintains the discretion to make an exception in limited and unique circumstances to authorize assimilative capacity to discharges that fall within Category 4 without an ACP but the Central Valley Water Board will still need to make all necessary findings pursuant to Resolution 68‐16.
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Section 4 Central Valley Salt and Nitrate Management Strategy
Table 4‐6. Summary of the Findings/Conditions Required to Demonstrate Compliance with the Nitrate Management Requirements Applicable to Path A
Discharge Central Valley Water Board Findings/Conditions
Category
Category 1
Discharge is equal to or better than the nitrate water quality objective of 10 mg/L‐N (i.e., less than 10 mg/L‐N); and, discharge is better than baseline receiving water quality.
Discharge is deemed to be in compliance with SNMP.
Category 2
Baseline receiving water quality has assimilative capacity.
Discharge(s) will not use more than 10% of available assimilative capacity over a 20‐year planning horizon and will not cause the receiving water to exceed a trigger level of 7.5 mg/L‐N over that planning horizon.
Discharge is not in a basin where the volume‐weighted upper zone concentration is increasing more than 0.1 mg/L NO3‐N per year using cumulative average annual increase over a 5‐year period.2
To determine amount of assimilative capacity consumed by the discharge, the Central Valley Water Board will consider the quality of the discharge as it enters the receiving water, accounting for reductions in nitrate mass or concentration as the discharge percolates to groundwater through the soil.1
Discharge will not unreasonably affect present and anticipated beneficial uses.
WDRs will ensure that BPTC at a level that is necessary to assure that pollution and nuisance will not occur, and that the highest water quality consistent with the maximum benefit to the people of the state will be maintained.
When the discharge is in an area that is covered by a Preliminary Management Zone Proposal, the Central Valley Water Board must consider the impact that granting available assimilative capacity to the individual under Path A will have on assimilative capacity for those that are part of the management zone.
Category 3
Baseline receiving water quality has assimilative capacity.
Discharge(s) will use more than 10% of available assimilative capacity over a 20‐year planning horizon.
Discharge will not cause the receiving water to exceed 7.5 mg/L for nitrate as N over a 20‐year planning horizon.
Discharge is in a basin where the volume‐weighted average of the upper zone is increasing more than 0.1 mg/L NO3‐N per year using cumulative average annual increase over a 5‐year period.2
To determine amount of assimilative capacity consumed by the discharge, the Central Valley Water Board will consider the quality of the discharge as it enters the receiving water, accounting for reductions in nitrate mass or concentration as the discharge percolates to groundwater through the soil.
Discharge will not unreasonably affect present and anticipated beneficial uses.
WDRs will result in BPTC at a level that is necessary to assure that pollution and nuisance will not occur, and that the highest water quality consistent with the maximum benefit to the people of the state will be maintained.
When the discharge is in an area that is covered by a Preliminary Management Zone Proposal, the Central Valley Water Board must consider the impact that granting available assimilative capacity to the individual under Path A will have on assimilative capacity for those that are part of the management zone.
Additional monitoring and periodic trend evaluation conditions are imposed to ensure compliance with SNMP.
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Section 4 Central Valley Salt and Nitrate Management Strategy
Table 4‐6. Summary of the Findings/Conditions Required to Demonstrate Compliance with the Nitrate Management Requirements Applicable to Path A
Discharge Central Valley Water Board Findings/Conditions
Category
Category 4
Receiving water quality has assimilative capacity.
Discharge(s) will use more than 10% of available assimilative capacity over a 20‐year planning horizon.
Discharge will cause the receiving water to exceed 75% of the water quality objective for nitrate (i.e., 7.5 mg/L‐N) but will not cause receiving water to exceed the water quality objective for nitrate over a 20‐year planning horizon; or the receiving water is at or above 50% of the water quality objective and the volume‐weighted average in the upper zone is exceeding an acceptable annual increase in concentration.2
To determine amount of assimilative capacity consumed by the discharge, the Central Valley Water Board will consider the quality of the discharge as it enters the receiving water, accounting for reductions in nitrate mass or concentration as the discharge percolates to groundwater through the soil.
Discharge will not unreasonably affect present and anticipated beneficial uses.
WDRs will result in BPTC at a level that is necessary to assure that pollution and nuisance will not occur, and that the highest water quality consistent with the maximum benefit to the people of the state will be maintained.
When the discharge is in an area that is covered by a Preliminary Management Zone Proposal, the Central Valley Water Board must consider the impact that granting available assimilative capacity to the individual under Path A will have on assimilative capacity for those that are part of the management zone.
Discharger are required to develop and implement an ACP for the nitrate components of the SNMP, which shall include the following:
- Identification of nitrate related drinking water supply issues in the area impacted by the discharge(s);
- Time schedule with milestones for addressing newly‐identified nitrate related drinking water supply issues in the area impacted by the discharge(s);
- Preliminary identification of the steps that will be taken to evaluate actions necessary to implement Management Goals 2 and 3, where reasonable and feasible, which may be phased in over time and will likely require further evaluation and assessment to identify proposed long‐term actions.
Category 5
Receiving water has no assimilative capacity for nitrates in First Encountered Groundwater.
Discharge exceeds the water quality objective for nitrate.
No reasonable, feasible or practicable means are available for discharger to comply with WDRs that would otherwise limit the discharge of nitrate to groundwater concentrations to less than 10 mg/L‐N.
It is infeasible, impracticable or unreasonable to prohibit the discharge.
Discharger required to develop and implement an ACP for the nitrate components of the SNMP, which shall include the following:
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Section 4 Central Valley Salt and Nitrate Management Strategy
Table 4‐6. Summary of the Findings/Conditions Required to Demonstrate Compliance with the Nitrate Management Requirements Applicable to Path A
Discharge
Category Central Valley Water Board Findings/Conditions
Category 5
(continued)
- Identification of nitrate related drinking water supply issues in the area impacted the discharge(s);
- Time schedule with milestones for addressing newly‐identified nitrate related drinking water supply issues in the area impacted by the discharge(s);
- Preliminary identification of the steps that will be taken to evaluate actions necessary to implement Management Goals 2 and 3 where reasonable and feasible, which may be phased in over time and will likely require further evaluation and assessment to identify proposed long‐term actions.
Discharger required to seek and obtain an exception in accordance with the Exceptions Policy.
1 In making this determination, the Central Valley Water Board shall consider information provided by the discharger that demonstrates that the level of nitrogen entering the receiving water is different than the level of nitrates in the discharge due to naturally occurring groundwater recharge, nitrogen transformation and losses, and nitrogen up take by plants. 2 Acceptable annual increase: upper zone concentrations do not increase more than 0.1 mg/L NO3‐N per year using cumulative average annual increase over a five‐year period. The cumulative average refers to an Olympic average, meaning that the highest and lowest sample results are removed; average is calculated from the remaining results. This helps address statistical outliers that otherwise may skew the results.
Path B – Participants in a Management Zone
PathBisforthosedischargersthatdesiretoworkcollectivelytocomplywiththeSNMPbyparticipationinamanagementzone.AfteranareaisactivatedforSNMPimplementationbasedonpriority,dischargersareencouragedtoworktogethertodevelopthePreliminaryManagementZoneProposaldescribedinFigure4‐3.Followingsubmittalofthisproposal(seeabovefortimeallowedtosubmit),dischargersthathaveselectedPathBwillcontinuetoimplementthisSNMPperthestepsillustratedinFigure4‐5,beginningwithafilingofanNOI.
Step1‐SubmittalofNoticeofIntent–Within60daysofavailabilityofaPreliminaryManagementZoneProposalforaspecifiedarea,dischargerswithinthatareathatintendtocomplywithPathB,shallsubmitanNOItotheCentralValleyWaterBoardthatincludes:(a)identificationofthemanagementzoneinwhichthedischargerintendstoparticipate,and(b)acknowledgementthattheyhavereviewedandunderstandthecommitmentsassociatedwithparticipationinthemanagementzonebasedonthePreliminaryManagementZoneProposalthatappliestotheirareaofdischarge.Ifanydischargerswithintheareaproposedforamanagementzonedecidenottoparticipateinthemanagementzone,theymustcomplywiththerequirementsspecifiedforPathA.
Step2–ImplementationofEAPandFinalManagementZoneProposal‐Aspartofparticipatinginamanagementzone,dischargerswillneedtocollectivelyberesponsibleforimplementingtheEAPthatwassubmittedaspartofthePreliminaryManagementZoneProposal.ThetimeforbeginningtoimplementtheEAPshallbebasedonCentralValleyWaterBoardacceptanceoftheEAP,whichshallbeindicatedthroughanoticetoproceedfromtheCentralValleyWaterBoardtotheleadentityresponsibleforthemanagementzoneWithin60daysaftersubmittalofthePreliminaryManagementZoneProposaltothe
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Section 4 Central Valley Salt and Nitrate Management Strategy
CentralValleyWaterBoardandifnoobjectionstotheEAPareprovidedinwritingbytheCentralValleyWaterBoard,themanagementzonemustbeginimplementingtheEAP.Further,althoughWDRsfordischargersparticipatinginamanagementzonewillnotyetberevisedatthisstepintheprocess,theSNMPrecommendsthattheCentralValleyWaterBoardfindparticipatingdischargersincompliancewithnitratecomponentsoftheSNMPaslongastheparticipantistimely,andingoodfaith,participatinginthemanagementzone.ParticipatinginthemanagementzoneincludesassistingintheimplementationoftheEAP,andassistingindevelopingtheFinalManagementZoneProposal.FordischargersthataresubjecttoaGeneralOrderasamemberofaThirdPartyGroup,ThirdPartyGroupparticipationonbehalfofitsmembersshallconstitutedischargerparticipation.ThirdPartyGroupsshallmakeallreasonableeffortstoinformitsmembersofparticipationinanyGroundwaterManagementZone.
Withina180daysaftersubmittalofaPreliminaryProposal,themanagementzonemustsubmitaFinalManagementZoneProposal.Figure4‐6summarizestherequirementsforaFinalManagementZoneProposal(seealsoGroundwaterManagementZonePolicyinAttachmentA‐1).
Figure 4‐5. Path B Steps to Compliance with SNMP
Figure 4‐6. Minimum Requirements for Final Management Zone Proposal
Timeline for development of a Management Zone Implementation Plan.
Updated list of participants.
Governance structure that, at a minimum, establishes the following: (a) roles and responsibilities of all
participants; (b) funding or cost‐share agreements to implement short term nitrate management
projects/activities;1 and (c) a mechanism to resolve disputes among participating dischargers.
Additional evaluation of groundwater conditions across management zone area for each basin/subbasin
covered, if necessary.
Identification of proposed approach for regulatory compliance (i.e., use of assimilative capacity and/or
seeking approval of an exception for meeting nitrate water quality objectives).
Explanation of how the management zone intends to interact and/or coordinate with other similar efforts
such as those underway pursuant to the SGMA.
1 If future legislative efforts result in the development of funds available for addressing short term and/or long term nitrate drinking water issues, the Final Management Zone proposal may include and/or indicate how use of such funds are coordinated to address nitrate drinking water related issues that would otherwise be the responsibility of the management zone participants.
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Section 4 Central Valley Salt and Nitrate Management Strategy
TheFinalManagementZoneProposalshallincludeatimelineforpreparationofadetailedManagementZoneImplementationPlanandindicateifthemanagementzoneisseekingcompliancethroughtheallocationofassimilativecapacityasallowedintheGroundwaterManagementZonePolicy,orthroughanexceptiontomeetingthewaterqualityobjectivefornitrateassetforthintheExceptionsPolicy(AttachmentA‐4).Figure4‐7summarizestheminimumrequirementsfortheManagementZoneImplementationPlan.
Step3‐RevisionofWDRs/CompliancewithSNMP–TheCentralValleyWaterBoardwillreviseWDRs/ConditionalWaiversforthosedischargersparticipatinginthemanagementzoneafterreceivingtheFinalManagementZoneProposal.RevisionstorelevantWDRs/ConditionalWaiversmayoccurindividually,orthrougharesolutionthatamendsallapplicableWDRs/ConditionalWaivers.UpontimelysubmittaloftheFinalManagementZoneProposal,dischargersidentifiedasbeingparticipantsofthemanagementzoneshallbedeemedtobeincompliancewithnitraterequirementsinindividualWDRs/ConditionalWaiversaslongasthedischarger(a)continuestobeanactiveparticipantinthemanagementzone;and(b)themanagementzoneismeetingidentifiedtimelinesandmilestonesinatimelymanner,includingimplementationoftheEAP.
BeforetheCentralValleyWaterBoardmaymodifyanyWDRstoincorporatetheuseofassimilativecapacityonamanagementzonebasisortoadoptanexceptiontomeetingawaterqualityobjectiveinaWDRforadischargerparticipatinginthemanagementzone,theCentralValleyWaterBoard’sExecutiveOfficermustapprovetheestablishmentofthemanagementzoneanditsimplementationplanafterprovidingpublicnoticeandopportunitytocomment.PriortoapprovalofamanagementzoneandaManagementZoneImplementationPlan,theCentralValleyWaterBoardmayadoptand/ormodifyWDRstoincludetimeschedulesthatallowdischargersparticipatinginamanagementzoneanappropriateamountoftimebeforebeingrequiredtocomplyimmediatelywithlimitationsrelateddirectlytonitratewaterqualityobjectives.ExecutiveOfficerapprovalofthemanagementzoneinnowaychangestherequirementthatanymodificationstoWDRsmustbeapprovedbytheCentralValleyWaterBoardafterpublicnoticeandhearing.
4.3.2.3 Allocation of Assimilative Capacity
Overall,theSNMPrecommendsthattheCentralValleyWaterBoardbepredisposedtoallocateassimilativecapacity,andallowlowerwaterquality,wheredoingsoassuresasignificantlybetteroutcomeforthepeopleofCaliforniathanwouldrequiringstrictcompliancewithdefaultwastedischargerequirements.Further,theSNMPrecommendsthattheCentralValleyWaterBoardprioritizeallocationsofassimilativecapacitywhenandwhereitwouldprovideademonstrablymoreeffectivemeansofassuringsafedrinkingwaterthanotheravailablepermittingalternatives.However,theSNMPalsorecognizestheimportanceofprotectinghighqualitywatersandforthisreason,theSNMPrecommendstriggerstomaintainanappropriatesafetyfactortoensurethathighqualityreceivingwatersdonotexceedthewaterqualityobjectivefornitrate.
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Section 4 Central Valley Salt and Nitrate Management Strategy
Figure 4‐7. Minimum Requirements for Management Zone Implementation Plan
It must be consistent with the management goals of the Central Valley SNMP, including, addressing short‐term and long‐
term drinking water needs affected by nitrates, plan for achieving balanced nitrate loadings within the management zone
(to the extend feasible and reasonable), and plan for establishing a managed aquifer restoration program to restore
nitrate levels to concentrations at or below the water quality objectives to the extent it is feasible and reasonable to do
so.
The highest water quality priority within any management zone where groundwater is impaired by nitrate contamination
is the assurance that a drinking water supply that meets drinking water standards is available to all drinking water users
within the management zone boundary.
It must document collaboration with residents that are the intended beneficiaries of short and long‐term efforts to
provide safe drinking water.
Funding or cost‐share agreements, or a process for developing such funding or cost‐share agreements, to implement
intermediate and long‐term nitrate management projects/activities.1
Implementation of nitrate management activities within a management zone may be prioritized based on factors
identified in the Central Valley SNMP and the results of the characterization of nitrate conditions. Prioritization provides
the basis for allocating resources with resources directed to the highest water quality priorities first.
It shall include a water quality characterization for each basin or subbasin covered by the management zone and nitrate
management measures consistent with the requirements established in the Central Valley SNMP, including:
o Characterization of nitrate conditions within the proposed management zone which will be used as the basis for
demonstrating how nitrate will be managed within the management zone over short and long‐term periods to meet
the management goals established in the Central Valley Region SNMP.
o Short (≤ 20 years) and long‐term (> 20 years) projects and/or planning activities that will be implemented within the
management zone, and in particular within prioritized areas (if such areas are identified in the Implementation Plan)
to make progress towards attaining each of the management goals established by the Central Valley SNMP. Over
time as water quality is managed in prioritized areas, updates to the plan may shift the priorities in the management
zone.
o Milestones related to achievement of the overall Central Valley SNMP’s long‐term goal of achieving balanced nitrate loadings and managed aquifer restoration.
o A short and long‐term schedule for implementation of nitrate management activities with interim milestones.
o Identification of triggers for the implementation of alternative procedures or measures to be implemented if the interim milestones are not met.
o A water quality surveillance and monitoring program that is adequate to assure that the plan when implemented is achieving the expected progress towards attainment of management goals.
o Consideration of areas outside of the management zone that may be impacted by discharges that occur within the
management zone boundary areas.
The plan may be modified periodically to incorporate changes based on new data or information, and should generally
be changes that will benefit water quality in the management zone. Any modifications to the plan that impact or
change timelines, milestones or deliverables identified in the Implementation Plan must be approved by the Central
Valley Water Board’s Executive Officer.
Identify the responsibilities of each regulated discharger, or groups of regulated dischargers participating in the
management zone to manage nitrate within the Zone.
Include a proposed monitoring program, or in the alternative, participate in a valley‐wide and/or regional groundwater
monitoring, if appropriate.
1 Should future legislative efforts result in the development of funds specific to addressing drinking water issues, such
funding should be considered as an appropriate funding source for providing short and/or long‐term drinking water, subject
to the terms, conditions and restrictions for the funding.
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Section 4 Central Valley Salt and Nitrate Management Strategy Ingeneral,todeterminethattheallocationofassimilativecapacity“willnotresultinwaterqualitylessthanthatprescribedinthepolicies,”theSNMPrecommendsthattheCentralValleyWaterBoardrequiredischargerstodemonstratethatthepermitteddischarge(s)willnotcausetheaveragenitrateconcentrationintherelevantgroundwatertoexceed10mg/L.TheSNMPrecommendsthatrelevantgroundwaterbetheareareferredtoasshallowgroundwater(seefootnote29),orbeavolume‐weightedaveragefortheupperzones.
Withrespecttodeterminingifassimilativecapacityisavailable,thelevelofdemonstrationneededwouldvarybasedonanumberofdifferentfactors.Forexample,fordischargesfromasinglefacility(oftenreferredtoasapointsourcedischarger),thedemonstrationmayberelativelysimpleifthedischargerisseekingtoshowavailableassimilativecapacityfromlookingatshallowgroundwaterandthedischargerhasthenecessarydataandinformationtoshowthatthedischargewillnotcauseshallowgroundwatertoexceedtheestablishedtriggerlevelsovera20‐yearplanninghorizon.Attheotherendofthescale,multipledischargersseekingtoshowassimilativecapacityavailableintheupperzoneoveradefinedmanagementzoneareawilllikelyneedmoreextensivedataandinformation,and/ormodeling,tomakethedemonstrationthatestablishedtriggerlevelswillnotbeexceededwithinadefinedtimeframe.Ingeneral,theCentralValleyWaterBoardshouldnotallocateuseofassimilativecapacitybasedonavolumeweightedaverageintheupperzonethatwouldresultingroundwaterexceedingatriggerlevelof75%ofthenitratewaterqualityobjectiveovera20‐yeartimeframe,unlesstheCentralValleyWaterBoardcanproperlyfindthatuseofassimilativecapacityabovethistriggerlevelwillnotresultinpollutionornuisanceoverthelongerterm.
TheallocationsofassimilativecapacitybytheCentralValleyWaterBoardshallbedeterminedbasedonthepermittingstrategypathwaythatindividualdischargers(PathA)orgroupsofdischargers(PathB)chooserelativetonitratepermitting.Section4.3.2.2abovedescribesindetailthetwopathways,andtheallocationofassimilativecapacitythatisapplicablebasedonthepathwaythatisselected.GrantingassimilativecapacitybasedontheupperzonewouldtypicallyneedtobeaccompaniedwithaproposedACPwhilegrantingassimilativecapacityinshallowgroundwatermaynot.Notably,however,theremaybeuniquecircumstanceswheretheCentralValleyWaterBoardfindsitappropriatetoconsidertheallocationofassimilativecapacitybasedontheupperzonebutdeterminesthatanACPisnotnecessary.Forexample,insomeareasoftheCentralValley,groundwaterqualityisexcellentwithrespecttonitratesandhistoricalandpresentdataindicatesthattherearelimitedthreatstodegradationofgroundwaterqualitybasedonpastandcurrentpractices.Insuchcases,theCentralValleyWaterBoardretainsitsdiscretiontodeterminetheavailabilityofassimilativecapacityusingaveragesintheupperzonewithouttriggeringtheneedforanACP.However,inallcases,iftherearelocalized“hotspots,”dischargers’causingorcontributingtonitratelevelsinthelocalizedareamayberequiredtoproposeanACPforthatspecificarea.
WhereanACPisrequired,theproposedACPshouldbedesignedtomitigatethesignificantadverseeffect(s)ofthepermitteddischarge(s)asitrelatestonitrateforwhichanexceptionisgranted.Moreover,aspartofanACPfornitrate,discharger(s)willneedtoshowthatgroundwaterusersdown‐gradientofthedischarge(s)havedrinkingwaterthatmeetsapplicablestateandfederalstandards.ACPsmayincludebothinterimactions(e.g.,bottledwater)intheshort‐term,permanentsolutions(suchaswell‐headtreatmentoralternativedrinkingwater
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Section 4 Central Valley Salt and Nitrate Management Strategy supplies)intheintermediateterm,andeffortstore‐attainthewaterqualityobjective(wherefeasibleandpracticable)overthelong‐term.Anyshortand/orlong‐termdrinkingwatersolutionsmustbedevelopedwithparticipationandconcurrenceofthosebenefitingfromtheproject(s).GuidelinesspecifictodevelopingACPsaresetforthinAttachmentA‐10oftheSNMP.
Topermittheuseofassimilativecapacity,theCentralValleyWaterBoardisrequiredtofindthatthedischarger,ordischargers,areimplementing“bestpracticabletreatmentorcontrolnecessarytoassurethatapollutionornuisancewillnotoccur.”Incaseswhereassimilativecapacityisbeinggrantedbasedonavailabilityofassimilativecapacityintheupperzone,theSNMPrecommendsthattheCentralValleyWaterBoardnextconsiderwhethermitigationstrategiesappliedatanyotherpointbetweenthedischargeandallaffecteddown‐gradientwaterusers(e.g.,wellheadtreatmentoralternativewatersupply,etc.)canbetterassuresafedrinkingwatertothoseusers.
Overall,itisanticipatedthatthelevelofanalysisnecessarytosupportanallocationofassimilativecapacity,andrequiredfindingsrelativetoevaluatingBPTCandcompliancewiththestate’sAntidegradationPolicy,willvarybasedontherelevantgroundwaterbeingusedtodetermineifassimilativecapacityisavailable(i.e.,shallowversusupperzones).Forexample,toevaluateifBPTCisbeingimplementedgrantinguseofassimilativecapacitybasedontheupperzone,theSNMPrecommendsthatacompleteantidegradationanalysisbepreparedbythedischarger(s),andthatsuchanalysisincludeanevaluationofalternatives,whichconsiderssocioeconomicimpactsofdifferentcontrol/treatmentmeasures,andifdifferentcontrol/treatmentmeasuresarereasonable,practicable,and/orfeasible.
InconjunctionwithevaluatingBPTC,theCentralValleyWaterBoardmustdeterminewhetherallocatingassimilativecapacitytoauthorizeadischargethatisexpectedtolowerwaterqualityis“consistentwithmaximumbenefittothepeopleofthestate.”Tomakethisfindingfornitratedischarges,theSNMPrecommendsthattheCentralValleyWaterBoardconsiderthefollowingfactors(seealsoSNMPAttachmentA‐11):
1)Economicandsocialcosts,tangibleandintangible,directandindirect,oftheproposed
dischargecomparedtothebenefitsforboththedischargerandallothersthatmaybeaffectedbythedischarge.Thisincludesanevaluationofthedischarger'scapacitytobearthecostofcompliance(e.g.,“affordability”)andanypotentialadverseimpactstothesurroundingcommunity.ThisisnotintendedtobeaformalCost‐BenefitAnalysis.
2)Environmentaleffectsofallowingorprohibitingtheproposeddischarge(especiallytheneteffectonwaterqualityintheregionandtheCentralValleyWaterBoard'slong‐termrestorationplans).Insomecases,wheretheneteffectonreceivingwaterqualityisshowntobespatiallyand/ortemporally‐limited,theCentralValleyWaterBoardmayconcludethatthedischargedoesnotresultinsignificantdegradation.
Ingeneral,theCentralValleyWaterBoardislesslikelytoallocateassimilativecapacitytodischargeswherethereisareasonable,feasible,andpracticablemeansforachievingcompliancewithtraditionalwastedischargerequirements.TheCentralValleyWaterBoardisalsounlikelytoprohibitdischargeswherenosuchmeansexistandconsidersthisoptiononlyasalastresort.
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Section 4 Central Valley Salt and Nitrate Management Strategy Notably,iftheCentralValleyWaterBoardconcludesthat,evenafterimplementingBPTC,adischargewillunreasonablyaffectpresentoranticipatedbeneficialusesofwater,orresultinwaterqualitylessthanthatprescribedintheBasinPlan,orcauseanunmitigatedpollutionornuisancetooccur,orisinconsistentwithmaximumbenefittothepeopleofthestate,thenlowerwaterqualitycannotbeauthorizedbyallocatingaportionoftheavailableassimilativecapacity.However,thedischarge(s)maystillbepermittediftheCentralValleyWaterBoarddeterminesthatitisappropriatetograntanexceptiontomeetingthewaterqualitystandardfornitrate.ThegrantingofsuchexceptionsfornitratesisdiscussedimmediatelybelowinSection4.3.2.4.
4.3.2.4 Granting an Exception to Meeting the Water Quality Objective for Nitrate TheSNMPrecommendsthatwhereexistinggroundwaterqualityalreadyexceedstheMCLfornitrate(i.e.,>10mg/L),orwheretheCentralValleyWaterBoardisunabletoallocateavailableassimilativecapacity,thattheCentralValleyWaterBoard'sforemostgoalshouldbetoencouragerapidimplementationofsafedrinkingwateralternatives.Toachievethisgoal,theCentralValleyWaterBoardneedsadditionalpermittingoptions.Specifically,theSNMPrecommendsthattheBasinPlansbeamendedtoextendandexpandtheCentralValleyWaterBoard'scurrentauthoritytoauthorizeexceptions34undercertaincircumstances.Thissectiondescribeshowsuchexceptionsauthorityshouldbeappliedwithrespecttopermittingnitratedischargestogroundwater.AmoredetaileddescriptionofthespecificbasinplanrevisionsrequiredtoenactabroaderexceptionspolicyandtherationaleforsuchchangesisprovidedinAttachmentA‐4(ExceptionsPolicy).
An“exception”allowstheCentralValleyWaterBoardtoauthorizeadischargetooccurevenwheredoingsomayviolateapplicablewaterqualitystandardsinthereceivinggroundwaterbasin.35Exceptionsaremostcommonlyemployedwhenthereisnofeasible,practicableorreasonablemeansforadischargetomeetwithwaterqualityobjectivesanditisnotfeasible,practicableorreasonabletoprohibitthedischarge.
Exceptionsareanappropriateoptionwhenstateauthoritiesdeterminethatprohibitingadischargewoulddomoreharmthangoodandallowingittocontinueisinthebestinterestsofthepeopleofthestate.Exceptionsmayalsobeanappropriatetooltoauthorizethetimerequiredtoimplementotherregulatorysolutions(e.g.,developingsite‐specificobjectivesorreevaluatingtheapplicablebeneficialuse)ortosupportaprogramofphasedimplementationandreasonableresourceallocationincludingtheplanningandpermittingactivitiesrequiredinsuchprograms.However,exceptionsarenotintendedtobeapermanentwaiverfromcomplianceobligations.Theyaresubjecttospecifiedconditionsandreviewableperiodically.
Ingrantinganexception,theCentralValleyWaterBoardmustconsiderthethreemanagementgoals,asdiscussedinSNMPSection4.1.1.Inaddition,thisSNMPrecommendstwooverarchingconditionswhenauthorizinganexceptionfornitrate:
34CentralValleyWaterBoardResolutionNo.R5‐2014‐0074(June6,2014);subsequentlyapprovedbytheSWRCBinRes.No.2015‐0010(March17,2015).
35Exceptionsfromcompliancewithwaterqualitystandardsinagroundwaterbasinissimilartotheconceptofa“variance”forsurfacewaters.Thekeydistinctionisthatexceptionsaregovernedexclusivelybystatelawandvariancesaresubjecttobothstateandfederalauthority.See,forexample,Resolution.No.R5‐2014‐0074.AlsoseeSNMPAttachmentA‐6.
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Section 4 Central Valley Salt and Nitrate Management Strategy
DischargersarestillexpectedtomakereasonablebesteffortsintendedtocomplywithapplicableWDRswhenthereexistsafeasibleandpracticablemeansfordoingso.
Inlieuofmeetingtheapplicablewaterqualityobjectivefornitrate,dischargerswillbe
expectedtoproposeanACPdesignedtomitigatethesignificantadverseeffect(s)oftheirpermitteddischargeasitrelatestonitrateforwhichanexceptionisgranted(seeAttachmentA‐10forrequiredelementsforanACP).Moreover,anACPfornitratewillneedtoassurethatgroundwaterusersdown‐gradientwhosegroundwaterisimpactedbythedischargehavedrinkingwaterthatmeetsapplicablestateandfederalstandards.ACPsmayincludeinterimactions(e.g.,bottledwater)intheshort‐term,permanentsolutions(suchaswell‐headtreatmentoralternativedrinkingwatersupplies)intheintermediateterm,andeffortstore‐attainthewaterqualityobjective(wherefeasibleandpracticable)overthelong‐term.
TheSNMPrecommendsthatexceptionsbereviewablefortworeasons:
Althoughthemeanstoassurecompliancemaynotcurrentlyexist,newsourcecontroland
treatmenttechnologiesmaybedevelopedinthefuture.Therefore,exceptionsneedtobeperiodicallyreassessed.
Permanentexceptionswouldbetantamounttonullifyingthedesignateduse.Therefore,wherecompliancecannotbeassured(evenoverthelong‐term),theStateWaterBoardhasstatedthattheRegionalBoardsshouldconsiderwhetherthewaterqualitystandarditselfisappropriate.36Exceptionsareintendedtocomplement,notreplace,thewaterqualitystandardsreviewprocess.
IntheBasinPlans,guidanceunderthecurrentexceptionspolicyisrestrictedtoalimitednumberofsalinityconstituents(electricalconductivity,TDS,chloride,sulfateandsodium).37AsdiscussedinSection4.2.2.3andAttachmentA‐4,thispolicyshouldberevisedinordertoprovidetheCentralValleyWaterBoardadditionalguidanceforallowingexceptionsfornitrateinWDRs.Specifically,pertherecommendationsofthisSNMP,tograntanexceptionfordischargesofnitrate,Figure4‐8summarizesthefactorsthattheSNMPtheCentralValleyWaterBoardshouldconsider.
Finally,toapproveanexceptionfornitrate,theSNMPrecommendsthattheCentralValleyWaterBoardconsiderwhethertheACPwillresultinahigherlevelofpublichealthprotection(e.g.,greaterorfasterriskreduction)thanislikelytootherwiseoccurifthedischargewereprohibitedorisakeypartofalong‐termrestorationstrategy.Inotherwords,willtheACPdoabetterjobofachievingthereal‐worldoutcomesoriginallysoughtbyrequiringstrictcompliancewithWDRstomeetwaterqualitystandards.
36StateWaterBoardOrderNo.WQ‐81‐5:IntheMatterofthePetitionoftheCityofLompocforReviewofOrderNo.80‐03(NPDESPermitNo.CA0048127),CaliforniaRegionalWaterQualityControlBoard,CentralCoastRegion.(March19,1981).
37CentralValleyWaterBoardResolutionNo.R5‐2014‐0074.
Section 4 Central Valley Salt and Nitrate Management Strategy
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Figure 4‐8. Factors to Consider When Authorizing an Exception for Nitrate in a WDR
Nitrate concentrations in the groundwater basin and whether they exceed or threaten to exceed the MCL.
If there is no feasible, practicable or reasonable means for the discharger to assure compliance with the
relevant WDRs governing nitrate under traditional permitting approaches, or if a proposed ACP can
further the goals of the SNMP more effectively than the traditional permitting approach.
With respect to determining if it is infeasible, impracticable or unreasonable to prohibit the discharge,
the Central Valley Water Board shall consider guidelines for making such an assessment if such
guidelines are developed in the future. The Central Valley Water Board’s obligation to follow any future
developed guidelines will depend on the process used for acceptance of the guidelines by the Central
Valley Water Board.
If authorizing the discharge is in the best interests of the people of the state.
The discharger, or group of dischargers, proposes to implement an ACP in lieu of meeting the relevant
WDRs for nitrate.
The ACP provides appropriate wellhead treatment or an alternative drinking water supply to down‐
gradient groundwater users impacted by the discharge(s) and where nitrate levels exceed or threaten to
exceed the MCL.1
The discharger continues to make reasonable best efforts, where feasible and practicable, to further
reduce nitrate concentrations in the discharge.
The discharger is participating in efforts towards implementation of the long‐term nitrate compliance
plan, as described in the permitting pathways options.
1 The discharger may propose to participate in a regional project or make one or more payments to a regional nitrate mitigation fund approved as an ACP subject to Regional Water Board review and approval.
4.3.3 Salt Management SaltmanagementunderthisSNMPwillbeguidedbytheSalinityManagementStrategy(seeAttachmentA‐3).Belowisasummaryofthekeyelementsofthisstrategy.
4.3.3.1 Overview
AsnotedinSection4.2.4.2,currentsalinitymanagementactivitiesmayonlyaddressabout15%oftheannualsaltload;accordingly,long‐termsolutions,includingdevelopmentofregionalde‐saltersandaCentralValleyregulatedbrinelineareneededtoaddresstheother85%.Theselong‐termmanagementstrategieswillrequiresignificantstateandfederalfundingtoimplement.
Inthemeantime,theCentralValleyWaterBoardmustimplementtheBasinPlansthroughtheadoptionofWDRs/ConditionalWaiversthatconsiderthebeneficialusestobeprotectedandthewaterqualityobjectivesassociatedwiththosebeneficialuses.
Becausethesolutionsforaddressingsalinityarelong‐terminnature,theCentralValleyWaterBoardneedstobeabletoconsiderinnovativesaltmanagementstrategiesforboththeshort‐termandthelong‐termthatmovetheregiontowardsaltbalanceandrestorationofimpactedareaswherereasonableandfeasible.ThisincludesneedingadditionalregulatoryflexibilitywithrespecttotheissuanceofWDRs/ConditionalWaiverswithsalinityrelatedrequirements.Somesalinity‐relatedpoliciesbeingproposedwiththisSNMPinclude:
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Section 4 Central Valley Salt and Nitrate Management Strategy
RevisionsoftheExceptionsPolicyforWasteDischargestoGroundwater(ExceptionsPolicy–seeSNMPAttachmentA‐4);
SalinityManagementtoProvideReasonableProtectionofAGRBeneficialUsesin
Groundwater(AGRPolicy–seeSNMPAttachmentA‐6);
RevisionsoftheSalinityVarianceProgram(SalinityVariancePolicy–seeSNMPAttachmentA‐5);
OffsetPolicy(seeSNMPAttachmentA‐7); DroughtandWaterConservationPolicy(seeSNMPAttachmentA‐8);and
GuidancetoImplementSecondaryMaximumContaminantLevels(SecondaryMCLPolicy,
seeSNMPAttachmentA‐9) TheapplicabilityofthesevariouspolicieswillvarydependingonimplementationoftheSalinityManagementStrategydescribedbelow.
4.3.3.2 Salinity Management Strategy
Overall,theSalinityManagementStrategyprovidestheCentralValleyWaterBoardwithaprocessformovingforwardwithlong‐termsalinitymanagementwhileidentifyinganinterimpermittingapproachforsalinitydischarges.Thisstrategyisintendedto:
Controltherateofdegradation(“manageddegradation”); Achievelong‐termsustainability(saltbalance),wherefeasible,practicableandreasonable;
and Protectsbeneficialusesbymeetingapplicablewaterqualityobjectivesandapplying
appropriateantidegradationconcerns. Becauseofthelong‐termnatureofsalinitymanagement,thisSalinityManagementStrategyisphasedovertime(Table4‐7).ThefirstphaseconsistsofdevelopingaPrioritizationandOptimizationStudyforsalinitymanagementfortheentiretyoftheCentralValleyRegion.TheoverallgoalofthisstudyistofurtherdefinetheconceptualdesignofSSALTS(CDMSmith2014,2016b)intoafeasibilitystudythatidentifiesappropriateregionalandsubregionalprojects,includinglocation,routingandimplementation/operationofspecificsaltmanagementprojects(seeTable4‐7).SubsequentphasesoftheSalinityManagementStrategywillemphasizeenvironmentalpermitting,engineeringdesignandacquiringfunding(PhaseII)andconstructionofsaltmitigationprojects(PhaseIII).
Figure4‐9providesanillustrationofanticipatedkeymilestonestobecompletedduringthePhaseIPrioritizationandOptimizationStudy.Whileitisanticipatedthatcompletionofthesemilestoneswilltakeapproximately10‐years,CV‐SALTSrecommendsthattheExecutiveOfficeroftheCentralValleyWaterBoardbegiventhedirectauthoritytoextendthistimeframeifcompellingreasonsoradequatejustificationisprovidedforanextension.
Section 4 Central Valley Salt and Nitrate Management Strategy
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OncethePrioritizationandOptimizationStudyiscompletedandtheBasinPlansareamendedbasedonrecommendationsfromtheStudy,PhaseIIoftheSalinityManagementPlanwillbeimplemented.ImplementationofPhaseII,inwholeorpart,willoccurasdirectedbythefindingsofthePrioritizationandOptimizationStudy,andafterapprovalofanynecessaryBasinPlanamendments.ThedurationofPhaseIIisanticipatedtobeapproximately10years.Aswith PhaseI,theExecutiveOfficeroftheCentralValleyWaterBoardshouldbegiventheauthoritytoextendtheanticipatedtimeframeforcompellingreasons,whichmayincludeavailabilityofadequatefundingtomoveforwardwithimplementationofPhaseII.ActualconstructionofphysicalprojectswouldoccurinPhaseIII,subjecttoavailablefunding,completionandapprovalofenvironmentalimpactstudies,andothernecessaryapprovals.
Table 4‐7. Salinity Management Strategy Phases
Strategy Phase Key Activities
Phase I
Prioritization and Optimization Study:
Evaluate the impact of all state policies that impact management of salinity in
the Central Valley region (e.g., Bay Delta Plan) to both surface and ground
waters;
Identify physical projects and proposed locations for long‐term management of
salinity (e.g., regulated brine line, salt‐sinks, regional/subregional de‐salters,
recharge areas, deep well injection, etc.);
Identify non‐physical projects that help with managing salinity;
Develop governance structures for implementation of the physical projects;
Identify funding sources necessary for implementation of large‐scale capital
physical projects (state and federal capital expenditures);
Identify the various environmental permits (and time‐line for obtaining the
permits) needed to implement the preferred physical projects;
Identify and propose any necessary Basin Plan changes that may be necessary
to implement the next Phase or Phases of the Salinity Management Strategy
(e.g., Offset Policy in surface waters);
Develop the conceptual design for applicable projects; and,
Other related activities.
Implement Interim Salinity Permitting Approach
Phase II
Environmental Permitting
Engineering Design
Obtain Funding
Revises Interim Salinity Permitting Approach (as needed)
Phase III
Salinity mitigation project construction including Central Valley regulated brine line
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Section 4 Central Valley Salt and Nitrate Management Strategy
Figure 4‐9. Milestones for Implementation of Phase I of the Salinity Management Strategy
Category
Year of Implementation
1 2 3 4 5 6 7 8 9 10
Stakeholder
Coordination
Stakeholder Coordination Meetings (as needed frequency)
SGMA GSA Coordination Meetings (as needed frequency)
Strategic Planning
Regulatory and Policy Evaluations
Phase II Planning
Governance
Governance Plan – Formation and Structure
Implementation and Refinement of Governance Plan
Funding
Funding Plan and Financing Strategy
Implementation of the Funding Plan and Financing Strategy
Prioritization &
Salinity Management
Analyses
Prioritization/Salt Management Analyses to Support
Identification of Salt Management Projects
Interim
Report
Conceptual Design of
Salt Management
Project
Concept Design for Subregional Salt Management Projects
and Regional CVBL Project
Special Studies
Groundwater Quality Trace
Constituent Stud
Emerging
Tech Update
No. 1
Emerging
Tech Update
No. 2
Emerging
Tech Update
No. 3
Recycled Water Imports
Study
Stormwater Recharge Master
Plan Study
Section 4 Central Valley Salt and Nitrate Management Strategy
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4.3.3.3 Interim Salinity Permitting Approach
WhilethePrioritizationandOptimizationStudyisbeingimplemented,thisSNMPrecommendsthattheBasinPlansbeamendedtoincludeanInterimSalinityPermittingApproachfordischargesofsalinity.ThisapproachwouldallowtheCentralValleyWaterBoardtomanagedegradationwhilethelong‐termsalinitymanagementeffortsarebeingimplemented.Becausethisapproachisintendedtobeinteriminnature,thisapproachwouldlikelyincludeasunsetprovisionintheBasinPlans,whichcouldbereneweddependingontheeffortsassociatedwithimplementingthevariousapplicablephasesoftheSalinityManagementStrategy.Attheoutset,CV‐SALTSrecommendsthattheInterimSalinityPermittingApproachbesetinplacefor15yearstoallowforimplementationofPhaseIoftheSalinityManagementStrategy.AttheendofPhaseI,theInterimSalinityPermittingApproachmayneedtobeextendedtoallowforimplementationofPhaseII,ortoadjusttheapproachasdeemedappropriatetoimplementPhaseII.AnysuchchangemayrequireaBasinPlanamendment.
Basis for Interim Salinity Permitting Approach
Theproposedinterimpermittingapproachforsalinityisbasedonthefollowingfindingsandgoverningprinciples: Thisapproachappliestopermittingsalinitydischargestosurfaceandgroundwaterinthe
definedinterimperiod. Theproposedapproachforpermittingsalinitydischargestosurfaceandgroundwatermust
beimplementedinamannerconsistentwithstateandfederalAntidegradationPolicies(i.e.,StateWaterBoardResolutionNo.68‐16andfederal40CFR131.12,respectively),asapplicable.
NoprovenmeansexistatpresentthatwillallowongoinghumanactivityintheCentralValleyRegionandmaintainsalinitylevelsthroughouteverygroundwaterbasin.38Waterconservationandincreasedrecycledwaterusealsoincreasesalinitylevelsingroundwater.Therefore,theInterimSalinityPermittingApproachfocusesonmanagingdegradationwhilethelong‐termcomponentsoftheSalinityManagementStrategyarebeingimplemented.
Itisreasonabletoemployalong‐terminterimpermittingapproach.Forexample,thesaltloadcurrentlyexistinginthevadosezoneistypicallyunknown,butthisloadcanimpactthequalityoftheunderlyinggroundwaterovermanyyears.Inaddition,thetimerequiredforrechargewatertotransitthevadosezoneandreturntouseasgroundwateratanirrigationsupplywellcanbesignificant.
Becauseofthelong‐termnatureandanticipatedhighcostsforimplementationoftheSalinityManagementStrategy,itisreasonabletoexpectthatdischargerswillnotbeabletoimplementsuchstrategiesindividually,butwillneedtoparticipateinalargerregion‐widecollectiveeffort.ThelargercollectiveeffortwouldbeginwithimplementationofthePrioritizationandOptimizationStudy(PhaseI),followedbyPhasesIIandIII.Duetothe
38TLBBasinPlan,Pg.III‐8.
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Section 4 Central Valley Salt and Nitrate Management Strategy
anticipatedcostsoftheseefforts,itisappropriatethatdischargesnotbesubjecttoextensiveand/orexpensivesalinitypermitrequirementsduringthisinterimperiod.Inparticular,individualdischargeeffortswouldhavelittleimpactonCentralValleysalinitymanagementasawhole,andassuchtheyarenotreasonable,feasibleorpracticable.
Itisreasonabletoexpectthatpermitrequirements(e.g.,WDRs/ConditionalWaivers,NPDESPermits)withrespecttoimplementingthelong‐termSalinityManagementStrategytoallowtimetoaddressdrinkingwaterissuesfornitratesfirst.TheSNMPidentifiesnitratedrinkingwaterissuesasitsfirstnear‐termpriority(seeSection4.1.1).Salinityisalsoapriority,butduetothecomplexitiesassociatedwithsalinity,itwillneedtobeaddressedoverthelong‐term.
Toallowforthephasedapproach,andtheinterimpermittingapproachdescribedherein,themanageddegradationobjectivesandspecifiedsalinitylimitationsintheTLBBasinPlanneedtobedeletedfromtheBasinPlan.
TheCentralValleyWaterBoardretainsauthoritytoidentifyhighprioritysalinedischargesand/orareaswheremorestringentcontrolprogramsmustbeimplemented.
Permitting Approach
Giventhediscussionabove,CV‐SALTSrecommendsaninterimpermittingapproachforsalinity‐relateddischargestosurfaceandgroundwater.ToimplementthisapproachinWDRs/ConditionalWaivers,theCentralValleyWaterBoardwillneedtorenew/reviseexistingWDRs/ConditionalWaiversandNPDESPermits.Further,duringthisinterimperiod,therewillbenewdischargers,orexistingdischargersseekingfacilitymodifications,thatwillhavesalinitydischarges.TheSNMPrecommendsaprioritizationapproachforaddressingnitratedrinkingwaterissuesbasedontheseverityofwaterqualitycontaminationandimmediateimpacttousers(seeSection4.2.3).ItisnottheintentoftheSalinityManagementStrategytouselimitedavailableresourcestoreviseindividualWDRs/ConditionalWaiversandNPDESPermitsforsalinity,especiallywheretherearesignificantnitratewaterqualityissues.However,thereisaneedtoensurethateffortsaremovingforwardwithrespecttothePhaseIPrioritizationandOptimizationStudy.
Tobalancethesetwoneeds,thisSNMPrecommendsthattheCentralValleyWaterBoard,incooperationwithstakeholders,implementaprocesswherebyaseriesofresolutions/ordersthatamendapplicableWDRs/ConditionalWaiversareconsideredforadoptionbytheCentralValleyWaterBoardtoimplementtheInterimPermittingApproach(seeSection4.3.3.5below).ThisapproachwouldprovidefordischargercompliancewithsalinitywaterqualityobjectivesduringPhaseIoftheimplementationoftheSalinityManagementStrategyaslongasthedischargerisincompliancewithInterimPermitProvisionsapplicabletotheirdischarge(asdescribedbelow),ratherthanthroughstringentwaterreceivinglimitsand/oreffluentlimits.
Interim Permit Provisions
InterimPermitProvisionswouldrequiredischargerstocontinuecurrentreasonable,feasibleandpracticableeffortstocontrollevelsofsalinityintheirdischargeswhileparticipatingineffortstoconductthePhaseIPrioritizationandOptimizationStudy.InterimPermitProvisionsmayincludethefollowingrequirementsasapplicableandappropriate:
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Section 4 Central Valley Salt and Nitrate Management Strategy
Implementsalinitymanagementpracticesand/orsourcecontrolefforts; Implementpollutionpreventionplans,watershedplans,and/orsaltreductionplans;
Monitorforsalinityinsurfaceandgroundwateraspartofexistingmonitoringprograms,or
throughregionalmonitoringprogramsasappropriate,whichshouldbecoordinatedwiththesurveillanceandmonitoringprogramestablishedtosupportimplementationofadoptedBasinPlanamendmentstofacilitateSNMPimplementation(seeSNMPSection5);39
Maintaincurrentdischargelevelsofsalinitytotheextentfeasible,reasonable,andpracticable,whileaccountingforconservation,salinitylevelsinthewatersupplysource,andsomeappropriateincrementofgrowth;and/or
Complywithinterimpermitlimits,totheextentthattheCentralValleyWaterBoardfindsitappropriateandnecessarytoadoptsuchlimits.
Alldischargerswouldberequired,andallinterimpermitswouldneedtoinclude,thefollowingrequirement: ParticipateineffortsrelatedtoconductingthePhaseIPrioritizationandOptimization
Study,andsubsequentPhasesIIandIIIasapplicable.Thelevelofparticipationwouldvarybasedonsalinityinthedischargeaswellaslocalconditionsandtheneededlevelofparticipationestablishedbytheleadentity(i.e.,CVSC)thatisoverseeingthePrioritizationandOptimizationStudy.
Itisrecommendedthattheresolutions/ordersestablishthetime‐frameforapplicationoftheInterimPermittingApproachandassociatedprovisions,whichcouldnotexceed15yearsinlength.ForNPDESdischargers,whicharesubjecttofederalregulatoryrequirements,CV‐SALTSrecommendsthatasNPDESpermitsarerenewedontheirnormalfive‐yearcycle,thattheCentralValleyWaterBoardconsiderapprovalofasalinityvariancepertheSalinityVariancePolicy(seeAttachmentA‐6),whichwouldincludearequirementtoparticipateinthePrioritizationandOptimizationStudyinordertoreceivethevariancefrommeetingapplicablesurfacewaterqualityobjectivesforsalinity.Or,inthealternative,theCentralValleyWaterBoardcouldconsideranNPDESwatershed‐basedpermitforsalinityasitdeemsappropriate,whichtoowouldrequirethosecoveredbythewatershed‐basedpermitforsalinitytoparticipateinthePrioritizationandOptimizationStudyefforts.
4.3.3.4 Opting Out of Participation in the Phase I Prioritization and Optimization Study ItisanticipatedthattheCentralValleyWaterBoardwillencourageandthatmostdischargerswillchoosetoparticipateineffortsrelatedtoconductingthePhaseIPrioritizationandOptimizationStudy.However,theCentralValleyWaterBoarddoesnothavetheauthoritytoforcedischargersintotheInterimPermittingApproach,andtoparticipateinthePrioritizationandOptimization
39TheCentralValleyWaterBoardwouldretainitsauthoritytoidentifyhighprioritysalinedischargeswheremorestringentcontrolprogramsmustbeimplemented.
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Section 4 Central Valley Salt and Nitrate Management Strategy Study.Further,somedischargershavealreadymadesignificantchangestotheiroperationinordertomeetrestrictivesalinitylimitationsandmaydecidethattheInterimPermittingApproachdoesnotprovidethemwithanappropriateincentivetoparticipate.Accordingly,theSalinityManagementStrategyincludesanoptionfordischargerstooptoutofparticipatingineffortsrelatedtothePrioritizationandOptimizationStudy.Forthosedischargersthatchoosetooptout,CV‐SALTSrecommendsthattheCentralValleyWaterBoardpermitsuchdischargersbyimplementingthefollowingprinciples:
1.InterpretingNarrativeWaterQualityObjectives–Whenitinterpretsnarrativewaterqualityobjectivesfordischargersoptingout,theCentralValleyWaterBoardshouldselectapplicablesalinitywaterqualityobjectivesinaconservativemanner.FortheAGRbeneficialuse,theCentralValleyWaterBoardshouldapplyaconservativelyprotectiveagriculturalgoal(e.g.,700µS/cmforelectricalconductivity).However,indeterminingtheagriculturalgoalthatshouldbeusedtointerpretthenarrativeobjective,theCentralValleyWaterBoardshouldconsiderwhetherasitespecificagriculturalgoalhasbeendevelopedand/orpreviouslyadoptedforthedischargerinquestion.Ifasitespecificgoalhasbeendevelopedand/orpreviouslyadopted,CV‐SALTSrecommendsthattheCentralValleyWaterBoardcontinuetoapplythatvalueifstillappropriate.FortheMUNbeneficialuse,theCentralValleyWaterBoardshouldinterpretwaterqualityobjectivesinamannerconsistentwiththeSNMPguidanceforImplementationofSecondaryMaximumContaminantLevels(seeAttachmentA‐9).40
2.AllocationofAssimilativeCapacity–Fordischargersoptingout,nonewallocationofassimilativecapacity,orexpansionofanallocationofassimilativecapacityshouldbegrantedbytheCentralValleyWaterBoard.However,ifadischargerhaspreviouslyreceivedanallocationofassimilativecapacity,andsuchallocationwasgrantedwiththesupportofanantidegradationstudy/analysis,thentheCentralValleyWaterBoardshouldcontinuetoallocatethepreviouslyapprovedassimilativecapacity,ifstillappropriate.Forgroundwaterdischargerswishingtooptout,thiswouldessentiallymeanthattheywouldneedtoshowthattheydonotcauseorcontributetoexceedancesofgroundwaterlimitationsforsalinityconstituentsinshallowgroundwaterunlesstheyhadpreviouslybeenpermittedtheuseofassimilativecapacityinthegroundwater,andsuchpreviouslyauthorizeduseofassimilativecapacitywasreauthorizedbytheCentralValleyWaterBoard.
3.IssuanceofTimeSchedules‐CV‐SALTSrecommendsthattheCentralValleyWaterBoarduseitsdiscretiontoissuetimeschedulesformeetingsalinitylimitationsforthoseoptingoutsparingly,andforminimaltimeperiods.Inotherwords,adischargeroptingoutshouldgenerallybeallowednomorethanfiveyearsformeetingarestrictivesalinitylimitation.However,theCentralValleyWaterBoardmaintainsthediscretiontodetermineifatimescheduleisappropriate,andthelength,fordischargersseekingtooptout.
40IftherearesitespecificwaterqualityobjectivesforsalinityconstituentsintheapplicableBasinPlan,suchobjectiveswouldapply.
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Section 4 Central Valley Salt and Nitrate Management Strategy
4.NPDESPermittees–ForsurfacewaterdischargerssubjecttoanNPDESpermitthatwishtooptout,theCentralValleyWaterBoardneedstodeterminereasonablepotentialinamannerthatisconsistentwith40CFR§122.44(d),andshoulddetermineifacompliancescheduleisappropriatebasedoncurrentapplicablelawsandpolicies,includingconsiderationofmeetingtheSNMPgoals.Wheninterpretinganarrativewaterqualityobjectivetoconductareasonablepotentialanalysis,theCentralValleyWaterBoardmustemployPrinciple1above.Further,NPDESpermitteesshouldnotbeallowedtooptoutiftheyareseekinganewallocationofassimilativecapacity(i.e.,mixingzone/dilutioncredit)inasurfacewaterformeetingthesalinitylimitation.However,theCentralValleyWaterBoardshouldconsidermaintaininganypreviouslyapprovedmixingzone/dilutioncredits.SalinityvarianceswouldnotbeanavailableoptionforthoseseekingtooptoutofthePrioritizationandOptimizationStudy.Insummary,NPDESdischargerswishingtooptoutwouldessentiallyneedtoshowthat:
Thedischargedoesnothavereasonablepotentialtoexceedtheapplicablecriteria;
Thedischargeisabletocomplywithawaterquality‐basedeffluentlimit,ifthereisreasonablepotential;or
Thedischargewillbeabletocomplywithawaterquality‐basedeffluentlimitation
subjecttothetermsofacompliancescheduleapprovedbytheCentralValleyWaterBoard.
4.3.3.5 Process for Development and Adoption of Resolutions/Orders to Implement Interim Permitting Approach Topreparetheappropriateresolutions/ordersthatamendthesalinityprovisionsinexistingpermitsandthatestablishsuchprovisionsforfuturepermits,CV‐SALTSrecommendsthattheCentralValleyWaterBoardandrelevantstakeholdersbegintheprocessfordevelopingsuchresolutions/ordersassoonaspossible.ItisrecommendedthatsuchresolutionsbepreparedandreadyforCentralValleyWaterBoardconsiderationwithinone(1)yearoftheBasinPlanamendmentsadoptedtofacilitateimplementationofthisSNMPbecomingeffective.Inthemeantime,whilesuchresolutionsarebeingdeveloped,CV‐SALTSrecommendsthattheCentralValleyWaterBoardpermitsalinitydischargesinareasonablemannerthatlooksforwardtowardsimplementingtheSalinityManagementStrategyassetforthintheSNMP.
4.3.3.6 Potential Future Permitting Approach
AtthecloseofPhaseI,orpotentiallyattheendofPhaseII,theCentralValleyWaterBoardmaydeterminethatitisnecessarytorevisetheInterimSalinityPermittingApproach.ThismayincludetheneedtoprovidefurtherguidancewithrespecttointerpretationandapplicationofsalinitystandardsforprotectionoftheAGRandMUNbeneficialuses.ThroughtheCV‐SALTSprocess,policydocumentshavebeenpreparedthataddressapplicationofsalinitystandardsforprotectionofAGR(AttachmentA‐5),aswellasapplicationofthesecondaryMCLsforsalinity(AttachmentA‐9).ThedocumentsarepartofthisSNMP,andmayresultinBasinPlanamendmentsin2017asdeterminedappropriate.However,fortheAGRPolicyinparticular(AttachmentA‐5),itmaybemoreappropriatetonotamendtheBasinPlansin2017to
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Section 4 Central Valley Salt and Nitrate Management Strategy incorporatethosepolicyrecommendations,butratherwaituntilaftercompletionofPhaseIoftheSalinityManagementStrategy.
4.3.4 Development of Alternative Data Section3.3ofthisSNMPprovidesasummaryoftheambientwaterqualityconditionsandavailableassimilativecapacityforeachofthegroundwaterbasinsandsubbasinsintheCentralValley.Dischargersmayusethesedataasthebasisfordeterminingiftheirsaltornitratedischargewillcausedegradationofthereceivingwater.Becausethesevaluesrepresentvolume‐weightedaveragesoftheavailablewaterqualitydataforthearea(horizontallyandvertically),potentialvariabilityfromonepartofagroundwaterbasin/subbasiniscapturedbythevaluesassignedtothegroundwaterbasins/subbasins.However,asillustratedinSection3,thisvariabilitycanbesignificant.
WhencharacterizingwaterqualityforthepurposesofcomplyingwiththeNOIrequirementsforcompliancewiththenitratepermittingrequirementsofthisSNMP(seeSection4.3.2.2),adischargermayrelyonthedatacontainedorreferencedhereinorprovidealternativedatathatisdeemedmorerepresentativeoftheareaundertheinfluenceofthedischarge.Fordischargesthatoccuroveralargearea(e.g.,agriculturaldischarges),thedefaultvaluesinthisSNMPmorelikelycharacterizetypicalwaterqualityconditions,althoughadischargemayprovideadditionalinformationandrefinethemodelsusedtocharacterizeexistingwaterqualityconditions.Incontrast,dischargersthatimpactarelativelysmallareamyfinditisappropriatetoevaluatetheexistingwaterqualityconditionsandtrendswithintheirareaofinfluence.
Ifadischargeroptstoprovideanalternativedatasetforthepurposesofassessingexistingwaterqualityconditionsandwaterqualitytrendsandprovidethebasisforanalternativeevaluationofassimilativecapacity,thedischargershallprovidethecompletesetofdatausedtodevelopalternativecompliancevaluesfortheareaundertheinfluenceofthedischarge.Ataminimum,thedatasetshouldinclude:
Welllocationsandwellconstructiondata,totheextentavailable,
Waterqualitydataforeachwellfortheshallowzone,upperzone,lowerzone,andthe
productionzone,totheextentdataareavailable. Evaluationofthequalityandrepresentativenessofthedatausedinthedataanalysis.
Methodstocalculateexistingambientwaterqualityandassimilativecapacityand
determinetrends. Ifthedataanalysisisbasedonwaterqualitymodeling,thedischargershallprovidesufficientinformationtoallowBoardstafftoevaluatethemodel.