using wqs variances to implement an adaptive management
TRANSCRIPT
GregCurreyClairMeehan
TetraTech,Inc.
NEWEAConference
January22,2018
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UsingWQSVariancestoImplementanAdaptiveManagementApproachtoNutrientSourceControl
• Forassessedwatersnationwide,nutrientsare:• 3rdleadingcauseofimpairmentinriverandstreammiles
• 2ndleadingcauseofimpairmentinlakes,reservoirs,andpondacres
• Stateshaveidentifiedover11,000nutrient-relatedimpairments
NutrientPollution
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NutrientCriteriainWQS
• Somestateshavenumericcriteriatotalnitrogenandtotalphosphorus(statewideorsite-specific)
• Moststateshavenarrativecriteriafornutrients—interpretedthroughnumerictargets
• NewEnglandstates• Allhavenarrativecriteria• Severalhavesite-specificnumericcriteria
• Maineisdevelopingcombinedcausalandresponsevariablecriteria
• Increasingnumbersofpermitswithnutrientmonitoringandlimits
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• Conventionalactivatedsludgesystem• NPDESrequiresTNandTPmonitoring
• AverageeffluentTNconcentration=16mg/L
• AverageeffluentTPconcentration=3.7mg/L
• Effluentflow• Maximumweeklyaverage=2.4MGD
• Design=3.8MGD
• Anticipatingnew,seasonaleffluentlimitationsforTNandTPbasedonachievingaverageconcentrationsof:• 3.5mg/LTN
• 0.25mg/LTP
Example:AnytownWWTF
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Option TargetEffluentConcentration(TEC)
TreatmentTechnologyOptions
A 13mg/LTN Optimizeexistingprocess(e.g.,aerationcontrol)
B 8.0mg/LTN
Configurationmodifications(e.g.,createanoxiczone),installnewmixersandblowers,upgradecontrolsystem
C 3.0mg/LTN Upgradetobiologicalnitrogenremoval(BNR)(e.g.,nitrification/denitrificationviaanoxic/oxiczoneorcycleretrofits;denitrificationfilter)
D <1.0mg/LTN Reverseosmosis(RO)
EvaluateOptionsforAttainingWQS—TN
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MeetingWQSCouldRequireSignificantImprovementinEffluentQuality…
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2
4
6
8
10
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14
16
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Current OptionA OptionB OptionC OptionD
TotalNitrogen(TN)EffluentConcentrationsAchievedbyTreatmentOptions(mg/L)
AttainingWQSrequiresaverageeffluentqualityof
3.5mg/L
ImplementOptionCtoattainWQS
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…butAchievingtheRequiredEffluentQualityMightnotbeFeasible
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0.5
1
1.5
2
2.5
3
Current OptionA(0%increase)
OptionB(44%increase)
OptionC(133%increase)
OptionD(200%increase)
AnnualPollutionControlCostsperHouseholdas%ofMedianHouseholdIncome(MHI)
0.9% 0.9%1.3%
2.1%
2.7%Q:Aretheretoolsavailablethatkeeptheultimatewaterqualitygoalinplacewhileallowingforachievable,incrementalimprovementsovertime?
A:Yes—Waterqualitystandardsvariancespairedwithpermitcomplianceschedules
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WaterQualityStandardsVariances—40CFR131.14
Awaterqualitystandardsvarianceforadischarger(s).
• Time-limiteddesignateduseandcriterionforaspecificpollutant(s)orwaterqualityparameter(s)
• Canbeaneffectivetoolforadaptivemanagement• TemporarychangetoWQS(requiresEPAapproval)
• Specifieshighestattainablecondition(HAC)thatappliesfordurationofvariance
• DurationisthetimejustifiedasneededtoachieveHAC
• Uponexpiration,thedischargermustmeetrequirementsbasedontheunderlyingWQSorapplyforanewvariance
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UsingVariancestoAchieveIncrementalProgress
UnderlyingW
QS
HighestAttainableCondition(HAC)
• Fortheregulatoryauthority:• Avoidspuntingonanimportantwaterqualityconcern
• AllowsprogresswhenabilitytoattainWQSisnotcertain• WhereunderlyingWQSarenotattainable,providestimeto
determinewhatisattainable
• Forthedischarger:• Focusesresourcesonworkingwiththeregulatoryauthority
tomakeimprovementvs.fightingnewrequirements
• Providestimetoputnutrientcontrolinthecontextofanoverallgameplanforfacilityimprovementsandupgrades
• Costeffectiveinvestment—smallexpenditureofresourcesnowforbetterdecision-makinginthefuture
WhyVariances?
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• Justificationbasedononeofsevenfactorsoutlinedinfederalregulationsat40CFR131.10(g)(asrequiredby40CFR131.14(2)(i))
• Mostcommonjustificationisthat“Controlsmorestringentthanthoserequiredbysections301(b)and306oftheActwouldresultinsubstantialandwidespreadeconomicandsocialimpact”
HowDoYouGetaVariance?—Justification
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DeterminewhetherupgradingtoattainWQSisfeasiblenoworthroughenforceablesequenceofevents
• Estimatecostofthetechnology
• PlanninglevelanalysisusingliteraturevaluestocalculatecapitalandO&Mcosts
• Annualizedcosts(Interestrate=i%;Term=nyears)
• Justifyvariancebasedonshowingthatimpactonthecommunitywillbesubstantialandwidespread[“factor6”in40CFR131.10(g)]
Step1:EvaluateOption(s)forAttainingWQS
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SubstantialEconomicandSocialImpactAnalysis:afterestimatingannualizedtreatmentcoststoachieveWQS,assessmagnitudeofcostburdenwithrespecttothecommunity’sincomeandotherrelevantindicatorsoffinancialcapability
• MunicipalPreliminaryScreener
• SecondaryTest
SubstantialEconomicandSocialImpactAnalysis
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AnytownWWTP—EvaluateCostofAttainingWQS
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0.5
1
1.5
2
2.5
3
Current OptionA(0%increase)
OptionB(44%increase)
OptionC(133%increase)
OptionD(200%increase)
AnnualPollutionControlCostsperHouseholdas%ofMedianHouseholdIncome(MHI)
0.9% 0.9%1.3%
2.1%
2.7%
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• MunicipalPreliminaryScreener—costsperhousehold• Anytowncurrentpollutioncontrolcosts=0.9%ofMHI
• PollutioncontrolcoststomeetWQS=2.1%ofMHI• <1.0%MHI=littleimpact—likelynotsubstantial
• 1.0%-2.0%MHI=mid-rangeimpact—maybesubstantial• >2.0%MHI=largeimpact—maybesubstantial
• UpgradingtomeetWQSmayresultinsubstantialimpact
• MovetoSecondaryTest
AnytownWWTPStep1:EvaluateOption(s)forAttainingWQS
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• SecondaryTest—financialandsocioeconomicconditions• Scorefinancialindicators(bondrating;debtindicators)• Scoresocioeconomicindicators(unemployment;MHIvs.statemedian;propertytaxrevenue;propertytaxcollectionrate)
• Scoringforeachindicator:1=weak;2=mid-range;3=strong
• AnytownTotalSecondaryScore=2.0
AnytownWWTP—SecondaryTest
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• Conclusion:municipalpreliminaryscreener(MPS)combinedwithinformationfromthesecondarytestshowsthatimpactislikelytobesubstantial…movetoWidespreadAnalysis
AnytownWWTPSubstantialImpactAnalysis—Conclusion
Assessment of Substantial Impacts Matrix (Table 5-2 from EPA Guidance)
MPS: 2.1%
Secondary Test Score: 2.0
Secondary Test Score MPS
Less than 1.0 Percent Between 1.0 and 2.0 Percent Greater than 2.0 Percent
Less than 1.5 ? X X
Between 1.5 and 2.5 ü ? X
Greater than 2.5 ü ü ?
Key: ü Impact is not likely to be substantial X Impact is likely to be substantial ? Impact is unclear
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• WidespreadImpactsAnalysis:assessthelikelihoodthatsubstantialeconomicandsocialimpactsonthecommunitywillbewidespread
• Consider:• HouseholdIncome• Unemploymentrate• Povertyrate• VulnerableIndustries• Propertyvalue
AnytownWWTP—WidespreadImpactsAnalysis
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• Highersewerratescouldmakecommunitylessattractive(residentsandbusinesses)inthelong-term
• Additionalburdenfeltmoststronglybypoverty-levelhouseholds
• Substantialimpactscommunity-widecouldresultinnegativechangestobroadindicatorsofcommunityfinancialhealth
• Conclusion:substantialimpactslikelytobewidespreadacrossthecommunity
AnytownWWTPWidespreadImpactsAnalysis—Conclusions
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• Step1Conclusions:• CostofupgradingtomeetunderlyingWQSwouldleadtosubstantialandwidespreadeconomicandsocialimpact[40CFR131.14and131.10(g)]
• AnytownWWTFiseligibleforaWQSvariance
• NextStep:Evaluateoptionsforincrementalimprovements—determinehighestattainablecondition(HAC)
AnytownWWTPStep1—Conclusions
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0
0.2
0.4
0.6
0.8
1
1.2
1.4
Current16mg/L
OptionA13mg/L
OptionB8.0mg/L
AnnualPollutionControlCostsperHouseholdas%ofMedianHouseholdIncome(MHI)
0.9% 0.9%
1.3%
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AnytownWWTPStep2:EvaluateOptionsforIncremental
Improvements—HAC
• Accountingforpollutioncontrolcostsas%ofMHI,rateincrease,andothersocioeconomicfactors:• OptionA:noimpact
• OptionB:lowerendof“mid-rangeimpact”
• Previouswidespreadanalysisshowedthatsubstantialimpactslikelytobewidespread
AnytownWWTPStep2:EvaluateOptionsforIncremental
Improvements—HAC
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EstablishingHACtoAchieveIncrementalProgress
UnderlyingW
QS
HighestAttainableCondition(HAC)
• Step2Conclusions:• ProposeHAC=averageTNof8.0mg/LbasedonOptionB
• betterperformancethanOptionA
• meetsobjectiveofincrementalimprovement
• affordablebasedoneconomicandsocialimpactanalysis
• Needadditionaltimetoimplementimprovements
• NextStep:Implementation
AnytownWWTPStep2—Conclusions
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• Varianceadoptionandapproval• Requestsubmittedtoregulatoryauthorityforreviewandadoption
• EPAreviewrequired—applicableunderCWAonlyifapproved
• NPDESpermit• HACinapprovedvariancebecomestheWQSforpurposesof
NPDESpermitting
• PermitcomplianceschedulemaybeauthorizediftimeneededtoattainHAC
• HACmustbereevaluatediftermofvarianceis>5years• AfterHACisachieved
• meetunderlyingWQSor
• newvarianceadoptedandapproved
AnytownWWTPStep3:Implementation
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