EPAResponsesto“ExternalPeerReviewofEPA’s‘ProposedMethodsandApproachesforDevelopingNumericNutrientCriteriaforFlorida’sInlandWaters’”HealthandEcologicalCriteriaDivision(4304T)OfficeofScienceandTechnologyU.S.EnvironmentalProtectionAgency1200PennsylvaniaAvenue,NWWashington,DC204602|PageThisdocumentsummarizesEPAresponsestothepeerreviewcommentsontheproposedmethodsandapproachesfordevelopmentofnumericnutrientcriteriaforFlorida’sinlandwaters.TheproposedmethodsdocumentoutlinedtheapproachesbeingconsideredbyEPAindevelopinginlandwaterscriteriaandthefeedbackfromreviewerswasincorporatedintotheapproachesusedforderivingthedraftnutrientcriteria.Thisdocumentbeginswithabriefoverviewofthereviewers’comments,asummaryofEPAresponses,andisfollowedbyamatrixofthespecificreviewercommentsandEPAresponses.SummaryofGeneralCommentsThedocumentthereviewerswereaskedtoreviewcoveredavarietyofwaterbodytypesandavarietyofanalyticaltopics.ThereviewswereallconstructiveandgenerallysupportiveofthetechnicalproposalsofferedbyEPA,withtworeviewerscommentingonthebreadthanddetailandapplaudingthefoundationbeingusedfordevelopingcriteria.Whilesomesuggestedanalyseswererecommended,forthemostparttheywererefinementsratherthanwholesaleanalysesthatEPAhadoverlooked.Tothisextent,EPAwascontentthatthemajorityoftechnicalapproacheswereadequatelyconsidered.Thereviewersfocusedonanumberofveryspecifictechnicaldetails,therefore,ageneralsummarywasdifficulttogenerate.Asaresult,eachspecificcommentwasaddressedinturninthematrixbelow.However,afewgeneralconcernswerepresented.Somereviewerswereconcernedabouttheclassificationapproachesused,specificallythatfinescalegeological/ecologicaldifferencesamongstlakeregionswerenotincorporated.Moreoveritwasfeltthatsomeconsistencyamonglakeandstreamclassificationscouldhavebeenconducted.Otherreviewerswerenotasconcernedwiththeextentofoverlaporwithhowrefinedclasseswere.Onereviewerinparticularwasconcernedabouttheapplicabilityto/protectivenessoffisheriesconditionsinmanylakeswiththecriteriaapproachesproposed.Asecondreviewersimplyquestionedtheextenttowhichavarietyofuseswereconsidered.Themajorityofreviewers,however,didnotcommentontheissueofapplicabilityofthecriteriatospecificuses.Anothergeneralconcernraisedbytworeviewerswastheeffectofvariabilityontheanalysesandtheirconcernthatitwasnotadequatelyaddressedintheanalysesselected,butmostreviewersseemedtoappreciatethefactthatvariabilityinmonitoringdataisarealityroutinelyfacedbyagenciesresponsibleformanagingwaterresources.Anothergeneralconcernraisedbyonereviewerwastheconceptofsitespecificityandtheissueofwhethertheapproachesusedwouldbeadequateforeverywaterbodyorwhethersitespecificapproacheswouldnotbemoreadequate.Again,thiswasanissueraisedspecifictoonereviewer.Themostconsistentconcernamongreviewerswastheorganizationandflowoftheoveralldocument,mostfeltthatitcouldusetighterorganizationandconsistencyamongstthechapter.3|PageEPAResponsetoGeneralCommentsEPAwasveryappreciativeofthetimeandthoroughnessofthereviewsandtheirconstructiveandsupportivetone.EPAprovidesresponsestothespecificcommentsinthematrixbelow,whichreallyrepresentthebulkofthecomments.Withregardstothegeneralcomments,EPAprovidesthefollowingresponse:•ClassificationIssue:Withregardstoclassification,regionalcriteriaderivationcannotaccountforeverynaturalfactorconstructinglakesasthereisatrade‐offbetweenadequatelyaccountingfordifferencesamongnaturaldriverstoreducenaturalvariabilityanddevelopingaclassificationstructurethatcanbeimplementedinamannerthatisfeasiblewithintheresourceconstraintsofwaterqualityagencies.Tothatend,EPAguidancerecommendsbroad‐scaleregionalclassificationstructures(e.g.,ecoregions).TheapproachusedforcriteriaderivationfornutrientsinFloridaisconsistentwiththeseconstraintsandguidancerecommendations.Totheextentpossible,EPAdidrefinetheclassificationsandtheirdiscussion,takingintoaccountthereviewerconcerns.•Protectivenessofcriteriaforfisheries:Theconcernvoicedoverthepotentiallyoverorunder‐protectivenatureofcriteriaforfisheriesmustbeweighedagainsttheresponsibilityofcriteriatoaddressaquaticlifeingeneralandnotspecificspecies.Toacertainextentthismustbeaddressedinusedesignation.Alsoofnoteistheissuethatcriteriamustprotectthemostsensitiveuseandnotonlyspecificuses.Forthiseffort,themajorfocuswasonaquaticlife,butaquaticlifeinitstotalityandnotspecificallygamefish.•Variability:Datavariabilityisarealityfacedbywaterresourceagencies.Totheextenttowhichitcanbereducedthroughsamplingandclassification,itisdone.Evenso,somevariabilitycannotbecompletelyremovedandthisvariabilityinfluencescriteriaselectiontotheextenttowhichthecriteriamustprotectuses.Mostreviewerswerecognizantofthisissueandunderstandtheconstraintspresentedbymonitoringdataanditsassociatedvariabilityincriteriaderivation.•Sitespecificity:Regionalnutrientcriteriaarenotequitablewithsite‐specificcriteria;however,thelatterisalwaysanoptionforagencieswhereconditionswarrantasite‐specificcriterion.Forregionalcriteriaderivation,however,theresourceconstraintsondevelopingsite‐specificcriteriaareconsiderable.Mostreviewersrecognizedthislimitationandtherewasonlyonereviewerwhoraisedtheconcernforinlandwaters,althoughasecondraisedtheconcernforestuaries.•Organizationandflow:EPAsharesthereviewersconcernsonorganizationandflowandthedrafttechnicalsupportdocument(TSD)havefocusedgreateffortonimprovingtheorganization,consistency,andflow.4|PageSpecificCommentsandEPAResponsesThefollowingtextcontainsresponsestothecommentsmadebypeerreviewersoftheoriginalUSEPA2009document:ProposedMethodsandApproachesforDevelopingNumericNutrientCriteriaforFlorida’sInlandWaters.ThepeerreviewcommentsaresummarizedintheAugust11,2009documententitled,“ExternalPeerReviewofEPA’s‘ProposedMethodsandApproachesforDevelopingNumericNutrientCriteriaforFlorida’sInlandWaters’.PeerReviewComments.DraftFinal”.CommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse1Reviewer11General3Lownutrientstandardsdonotfavor“fishable”Ofimportanceistherelationof“fishable”to“swimmable”intheso‐called“interim”goalsoftheCWA,andalsotheirrelationtotheotherstatedgoal,“restorationofchemical,physicalandbiologicalintegrity.”Thereseemstobeabeliefthatfishableequatesto“maximumyield.”Inasense,fishablemeansthatitisnotunhealthytofish(contactisnotharmful),fisharepresent(notdeadfromfishkills),andthatthefisharesafetoeat(uncontaminated).Fishabledoesnotimplyaguaranteethateveryonewillcatchafishnorthattrophy‐sizefisharepresent.2Reviewer11General3FloridaFishandWildlifeConservationCommissionhadnopartincreationofdocumentSeeresponsetocomment15|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse3Reviewer11General3Asstandardscurrentlyset,excellentfishingandwildlifelakeswillbeclassifiedasimpairedAgeologicaldiscussionwasaddedtotheclassificationsection.Classificationmustneedbeparsimoniousforstandardsapplication,thereforewhatmaybeahyper‐refinedecologicalclassificationmaynotbepracticalfromanimplementationstandpoint.4Reviewer11General4Geologyisnotwellconsideredinlakes.Lakemorphologyandhydrologyignored,expanduseofVollendweiderModel(Section14.2.1).Seecomment35Reviewer11General4Manyapproachesusedindocumenttodefinenutrientstandardsdonothavelong‐termdatatodefinetruebackgroundvarianceTheapproachesreflectthebestavailabledataandanalysis.6Reviewer11General4Someformoflong‐termvariabilityneedstobepartofnutrientstandardforlakesOnewaytoinvestigatenutrientresponseistomodelnaturalfactorsaswell.ModelingpH,colorandconductivityfirstandlookingatresidualsvs.nutrientsisanotherapproach.ThisapproachcanalsobeusedwithstreamsusingsimilarnaturalpredictorsandSCIoralgalmetrics.Thisapproachwasconsidered,butwasnotusedduetodatalimitationsandconstraints.6|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse7Reviewer11General440PTUthresholdforclearandcoloredsystemsnotidealgivennaturalFloridalakecolorvariabilityAmoregeographicfactormightbebetterthanusingcolor–butintheabsence,alongtermcoloraverageispracticable.SeealsoanalysisbyFDEPrelatedtocoloraveraging.8Reviewer11General4Approachestosettingstandardsusedindocumentshouldnotbeindependentofeachotherandapplicationtodifferentwaterbody‐typesshouldbethesameReviewerconcernsabouttheorganizationandcontextofdifferentwaterbodytypeswasimprovedintheTSDforEPA’sproposedrule.9Reviewer11General4UseGriffithetal.1997methodologytodevelopcomprehensiveEcoregionsbasedonlong‐termwaterchemistrydatainordertodefinenormalbackgroundvarianceFishabilityisunderprotected,swimmingisadequatelyprotected.Ageologicaldiscussionwasaddedtotheclassificationsection.Classificationmustneedsbeparsimoniousforstandardsapplication,thereforewhatmaybeahyper‐refinedecologicalclassificationmaynotbepracticalfromanimplementationstandpoint.10Reviewer31General6SmallsamplessizesusedinSCIandLVIstatisticalanalysisofmacroinvertebrateandvegetation(usedtoexplainvariationwithinmetricscores)limitsreadabilityofnutrientnoise.Seeresponsetocomment57|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse11Reviewer31General6ReportvagueastowhichSCIdatausedinanalysesandifdatawassubjecttofilteringThishasbeenclarifiedintheTSDforEPA’sproposedrule.12Reviewer31General6ChangepointanalysiswouldserveasanadditionallineofevidencesupportingobservedrelationshipsbetweennutrientandbiologicalmetricsThiscommentwasconsidered,theanalysiswaspursued,andisaddressedintheTSDforEPA’sproposedrule.13Reviewer31General7ForChapter7,referencerangeapproachshouldbesupplantedwithan“all”sitesapproach(asinChapter11)Thiscommentwasconsidered,theanalysiswaspursued,andisaddressedintheTSDforEPA’sproposedrule.14Reviewer31General7LongitudinalstudyofSteinhatcheeandWaccasassabasinsandestuarieswouldbemorecompellingifanitrogenenrichedsystemwasofferedforcomparisonThiswasanFDEPeffortandwasnotfurtherconsideredbyEPA.15Reviewer31General7Chapter9basisforchlorophyllathresholdsforlakes:reportandappendicesvagueastowhichdatausedandthestrengthandformoftherelationshipsformingTSISeeresponsetoconcernsforchapter9.8|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse16Reviewer31General7Relationshipbetweencyanobacteriaandchlorophyllaequivocal,realquestioniswhetherincreasingnutrientconcentrationaltersalgalcommunitycompositioninawaythatincreasesprobabilityofalgalbloomsCompositiondataunavailable.17Reviewer31General7DatausedforChapter10nutrient‐LVIstressor‐responserelationshipdemonstrationshouldbeusedinchangepointanalysisasadditionallineofevidencetosupportderivedcriteriaThiscommentwasconsidered,theanalysiswaspursued,andisaddressedintheTSDforEPA’sproposedrule.18Reviewer31General8TheallsiteschemistrydatashouldbepairedwithbiologicaldataandreexaminedwithinrangesofthebiologicaldataThiscommentwasconsidered,theanalysiswaspursued,andisaddressedintheTSDforEPA’sproposedrule.19Reviewer31General8Chapter12,theapplicabilityofextrapolationofbackgroundnutrientconcentrationsforstreamsquestionableThisanalysiswasconsidered,butwasnotusedforsimilarlimitationstothoseexpressed.ThisisdetailedintheTSDforEPA’sproposedrule.20Reviewer31General8MultipleregressionmodelsinChapter13offermorerefinedwaytoderivecriteriathenconventionallinearmodelsinChapters9and10Noresponsenecessary.9|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse21Reviewer31General8Chapter14,providebriefsummaryofTMDLswithdetailsofmodelsasappendices.DerivedstreamreachconcentrationsinTable10shouldbecomparedtoreferenceranges.Expressionofuncertaintyaroundestimatesshouldbeprovided.Thiscommentwasnotrelevantforinlandwaters,butarebeingincorporatedintotheestuarinecriteriadevelopmenteffort.22Reviewer41General8NosynthesiscomponentthatconsidershowvariousapproachesfittogetherSeveralreviewersexpressedadesiretoseeasynthesisandintegrationofalltheinformation.TheTSDforEPA’sproposedruleprovidethissynthesisandintegration.23Reviewer41General8ShouldreconciledifferencesamongnumbersproducedbeeachmethodSeveralreviewersexpressedadesiretoseeasynthesisandintegrationofalltheinformation.TheTSDforEPA’sproposedruleprovidethissynthesisandintegration.24Reviewer41General9LevelofeffortnotuniformacrossapproachesNoresponsenecessary.25Reviewer41General9ProvidemorediscussionontheinterfacebetweenscienceandpolicySeveralreviewersexpressedadesiretoseeasynthesisandintegrationofalltheinformation.TheTSDforEPA’sproposedruleprovidethissynthesisandintegration.10|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse26Reviewer51General9TheproposaldoesnotexplicitlyincludeasecondresponseparametertochlorophyllaforconsiderationandfocusCommentconsideredandfinalanalysesaddressthiscommentandarepresentedintheTSDforEPA’sproposedrule.However,chlorophyllaisprincipalrecommendedresponsevariable.27Reviewer51General9DocumentdoesnotconsiderstressorsotherthanTNandTPOtherstressorsareconsideredtotheextentprovidedbythedataandlimitationsofanalysis.Primaryfocuswasonnutrientsforpurposesofnutrientcriteriaderivation.28Reviewer51General9Provisionfordifferentialapplicationofcriteria,dependingonconditionsandgeographyApplicationdoesnotvarybylocation,butcriteriado.Thecomplexityofecologicalconditionshastobeweighedagainsttheparsimonywhichbenefitsimplementation.Thisisweighedintheanalysisandruledevelopment.29Reviewer51General10SouthFloridaestuariesareabsentfromdiscussionandanalysisThiscommentisbeingincorporatedintoEPA’sestuarinecriteriadevelopmenteffort,southFloridaestuariesarebeingaddressed.30Reviewer51General10ModelsfordownstreamloadingcalculationsinsufficienttoassesswhethercriteriaprotectiveofdownstreamwatersthatdonotreceivecoherentmassflowThiscommentisbeingincorporatedintoEPA’sestuarinecriteriadevelopmenteffort,downstreammodelsarebeingrevisedtotheextentpracticable.11|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse31Reviewer51General10DocumentlacksoutlineofthekindsofdatarequiredtoimplementanutrientstrategyThisisclarifiedintheTSDforEPA’sproposedrule.32Reviewer51General10IncludegeneralcaveataboutthehysteresiseffectThishasbeenaddressedtotheextentpracticablegivendatalimitations.33Reviewer12Ch.311IBIcannotaccountforvariabilityinanthropogenicimpacts,andthusSCI,LVI,andSDIwrongapproachforsettingnutrientstandardsTheSCI,componentmetrics,andothermetricsshowedvariablebutsignificantresponsetonutrients.Stressor‐responserelationshipswerenotusedintheprimarycriteriaderivationforstreams.ThiscommentwasconsideredinfurtherapplyingtheseanalysesanduseoftheSCI.SeeTSDAppendixB‐1.34Reviewer12Ch.311AnybiologicalindexthatvarywithnaturallyoccurringgradientwillbeoflittleuseindeterminingtheextentofanthropogenicimpactsSeecomment3335Reviewer12Ch.311ShortcomingofLVIisthereisnometricinitaccountingforthetotalabundanceofaquaticplantsinalakesystemThiscommentwasconsideredinsubsequentanalysisanduseoftheLVI.SeetheTSDforEPA’sproposedrule.12|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse36Reviewer22Ch.312SCI’suseindetectingnutrientpollutiononlypartiallysuccessful,beingviableonlywhenawaterbodysuffersfromchronicnutrientpollution.Acuteimpactswillbemissed.Seecomment3337Reviewer22Ch.312InvasivenuisancespeciesdonotrequireexcessivenutrientstoproliferateandtheLVIwillnotreflectnutrientloadingThiscommentwasconsideredinsubsequentanalysisanduseoftheLVI.SeetheTSDforEPA’sproposedrule.38Reviewer22Ch.312SDIisnotusefulfornutrientloadingassessmentgivenFlorida’snaturallyacidicwatersThiscommentwasconsideredinsubsequentanalysisanduseoftheSDI.SeetheTSDforEPA’sproposedrule.39Reviewer32Ch.313PeriphytonSDIstillindevelopmentalstageforFloridawatersSeecomment3840Reviewer42Ch.313Distinctionbetweenreferenceandimpairednotclear.ExpertsconductingsitequalitativeevaluationscouldnotagreeonsitesdeterminedtobeinthemiddleoftheBCG.Seecomment3813|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse41Reviewer42Ch.313Analysisusedtosupportpositionthat“notreference”equalsimpairedprejudgesapolicydecisionregardingattainment,whichisnotsynonymouswithreferenceSeecomment3842Reviewer42Ch.314AgreeswithreportthattheSDIis“anunreliabletoolforassessingadversehumaneffectsonstreamsystems”Seecomment3843Reviewer42Ch.314ThesensitivityofdiatomstopHisastrongconfoundingfactorSeecomment3844Reviewer52Ch.314UtilityofSDInotclearatthispoint,applicationtoFloridauntestedandrequiresfurtherdevelopmentSeecomment3845Reviewer13Ch.415Approachusedtosetnitrate‐nitritecriteriaforstreamsonlyusesconcentrationwhiletotalloadofnitrogenisnotaccountedforindifferentsystemsIncorporationofcommentisnotpracticalgivenconstraintsofavailabledata.However,loadsareconsideredinestablishingdownstreamprotectivevalues(seeDPVapproachesintheTSDforEPA’sproposedrule,Chapter2).46Reviewer23Ch.415Reviewandcitepeer‐reviewedliteraturetoaddfurtherscientificvalidityandcomplimentexisting"greyliterature"citationsThisismoredevelopedintheTSDforEPA’sproposedrule.14|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse47Reviewer23Ch.415Includedataonammoniainsprings‐iflowthenproposedstandardvalid,ifhighadjustmentsmaybeneededIncorporationofcommentisnotpracticalgivenconstraintsofavailabledata.However,loadsareconsideredinestablishingdownstreamprotectivevalues(seeDPVapproachesintheTSDforEPA’sproposedrule,Chapter2).48Reviewer43Ch.416ThebasisfortheproposedlagtimebetweenhumanpopulationgrowthandincreasingnitrogenconcentrationsshouldbestrengthenedIncorporationofcommentisnotpracticalgivenconstraintsofavailabledata.However,loadsareconsideredinestablishingdownstreamprotectivevalues(seeDPVapproachesintheTSDforEPA’sproposedrule,Chapter2).49Reviewer43Ch.416Providedocumentationtosupportclaim"nitrate‐nitritehasbeenlinkedtomanyoftheobserveddetrimentalimpactsinspringsystems."ThishasbeenclarifiedintheTSDforEPA’sproposedrule.15|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse50Reviewer43Ch.416TheappropriatenessofderivingcriteriabasedonstudiesofnuisancespeciesLyngbyainadisturbedecosystemnotdiscussed.Concludingthatspringswithnitrateconcentrationsbelowalabdeterminedthresholdwillsupportnativeplantcommunityisunsupported.Fieldsurveyscontainnoinformationaboutnitrateconcentrationsinspringsthatsupporthealthynativeplantcommunities.Seesupportingpapersforspringscriteriainthefederaldocketfortheproposedrule.51Reviewer53Ch.417ExpandingthisanalysisandprotocolforcriteriadevelopmenttoallstreamsystemsmaypresentdifficultywithtransportabilitygiventhedifferencesbetweenspringandstreamsystemsEPAagreeswiththiscomment,theeffectwasconsidered,andnitratecriteriaarenotconsideredforstreamsintheprincipalcriteriaapproach.52Reviewer53Ch.417Ninputstostreamsmaybemoredetectableandcontrollable,whicharguesforadifferentsetofanalyticaltoolsEPAisunsureoftheveracityofthecommentwithregardstodetectingnutrients.However,nitratecriteriaarenotconsideredforstreamsintheprincipalcriteriaapproach.16|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse53Reviewer53Ch.417Basedondatapresented,boththenuisancemacroalgaeand"excessive"algalgrowthcriteriasuggestaTNthresholdcloserto0.23mg/LtomoreeffectivelyprovideamarginofsafetyWhenweighingthedifferentfactorsEPAdecidedonthemoreconvincingconcentrationspresentedintheTSDforEPA’sproposedrule,especiallygiventheadditionalanalysesconsidered.54Reviewer53Ch.417p.49:Conservativetargetconcentrationshouldbe401insteadof420ugN/LSeeresponsetocomment5355Reviewer53Ch.417p.49:Inconsistentuseofunitsdistracting,concentrationsshouldallbeexpressedinmicrograms.ThisisclarifiedintheTSDforEPA’sproposedrule.56Reviewer53Ch.417p.51:why0.23isunnecessarilyprotectiveisnotmadeclearSeeresponsetocomment5357Reviewer53Ch.417Figure4‐12:Whyistheincreaseevidentabove0.24mg/Ldisregarded?ThelowerthresholdisbeingsetatoohighaconcentrationSeeresponsetocomment5358Reviewer14Ch.518Strongestsectionofdocument,broadenthisapproachtoothersectionsNotechnicalresponsenecessary.59Reviewer14Ch.518CombiningallavailabledataandrefiningGriffithetal.(1997)lakeregionsbestapproachSeecomment317|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse60Reviewer24Ch.518Includeinformationon"nutrientreferencestreams/sites"criteriainCh.5ThisconcernisclarifiedintheTSDforEPA’sproposedrule.61Reviewer24Ch.518NotexplainedwhyEvergladesregionnotaddressedTheEvergladeshaveexistingcriteria,andhavebeenaddressedinthefinalcriteriadocument.62Reviewer24Ch.518TheTNstreamnutrientregionsneedtobemappedThisconcernisclarifiedintheTSDforEPA’sproposedrule.63Reviewer54Ch.519NotclearlyexplainedhowecoregionapproachandbiologicaltaxonomyapproachwereusedinsupportofnutrientapproachEcoregionandBioregionreallydon’tcontributetothenutrientregions.CommentconsideredandhasbeenclarifiedintheTSDforEPA’sproposedrule.64Reviewer54Ch.519AdisproportionateamountofthedocumentdedicatedtothemeansbywhichthewesternpeninsulaissplitintotwoecoregionsNotechnicalresponsenecessary.65Reviewer54Ch.519ThediscussionofregionalizationbasedonTNisbarelymentioned.ThisconcernisclarifiedintheTSDforEPA’sproposedrule.66Reviewer54Ch.519NodiscussiononhowthesouthernportionofFloridawouldbesubdividedSouthernFloridahadcriteriadevelopedintheTSDforEPA’sproposedrule.67Reviewer54Ch.519Furtherdetailonstate‐wideregionalizationrequiredThisconcernisclarifiedintheTSDforEPA’sproposedrule.18|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse68Reviewer54Ch.519p.61:ThestatementthatbioregionswerenotsufficientlyhomogenouswithregardtonutrientconcentrationhasnobackupThisconcernisclarifiedintheTSDforEPA’sproposedrule.69Reviewer54Ch.519Whatwerethecriteriaforhomogeneityandwhy?Seeresponsetocomment68.70Reviewer54Ch.519ThealternativesbasedonaslewofvariablesarenotwelldefinednorisajustificationprovidedfortheiruseThisconcernisclarifiedintheTSDforEPA’sproposedrule.71Reviewer54Ch.519HowwillthedisparateregionalizationsbetweenNandPdrivenbereconciledtoeachotherandtothebiogeography?ThisconcernisclarifiedintheTSDforEPA’sproposedrule.72Reviewer54Ch.519Itwouldbeusefultounderstandhowtheregionalizationwillbeincorporatedintotheoverallprocessofcriteriadevelopmenthereaspartofthechapterdescribingtheclassificationframeworkitself.ThisconcernisclarifiedintheTSDforEPA’sproposedrule.19|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse73Reviewer15Ch.620Bestapproachtoevaluatebiologicalstressor‐responseistomakesuretoseparatestreamsintoecoregionsbasedongeology,hydrologyandphysiographythendevelopthebestmodelsrelatingbiologicalmeasurestophysicalfactorsofthestreamandcomparetheresidualsofthesemodelstonutrientconcentrationswithinecoregionsEPAconsideredthesefactors.Seecomments3,6,and34.74Reviewer25Ch.620UsingbenthictaxatoassessnutrientimpactscanatbestprovidepartialguidanceSeecomment3375Reviewer25Ch.620TheauthorsneedtoaddtoFigure6‐1ther2andpvalues,sothereadercanseetheindividualstatisticsassociatedwiththerelationshipsValidcomment.Thestressor‐responseapproachesforstreamswerenotusedintheruledevelopment.Butthisconcernhasbeenconsideredinfiguresandtables.76Reviewer25Ch.620Firstparagraphonpage73–whywould%verytoleranttaxashowanadverseresponsetoincreasingN?Validcomment.Thestressor‐responseapproachesforstreamswerenotusedintheruledevelopmentbecauseofhighlyvariableresponse.Andseecomment33.20|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse77Reviewer25Ch.620Inadditiontosearchingfornutrientcriteria,itisusefultodeterminenuisancelevelsofperiphytonbiomassthatcanafflictstreamsFinalcriteriawerenotbasedonstressor‐response,giventhelimitationsofdataandvariabilityinrelationships.ThisisdetailedintheTSDforEPA’sproposedrule.78Reviewer25Ch.620‐21Additionalapproaches:Doddsetal.1998andDoddsetal.2002;Mallinetal.2001,2002,and2004(nutrientadditionbioassaysconductedonstreamwaterforvariousecoregions)Finalcriteriawerenotbasedonstressor‐response,giventhelimitationsofdataandvariabilityinrelationships.ThisisdetailedintheTSDforEPA’sproposedrule.79Reviewer25Ch.621ThereareheterotrophicresponsestonutrientloadingthatarenotusuallymeasuredorevenconsideredDataonheterotrophicresponseswasnotavailable.80Reviewer35Ch.622TheregressionsinvolvingtheSCIandSDI(and/ortheircomponentmetrics)appearconfoundedbymulticollinearitySeecomment33.81Reviewer35Ch.622Forthepurposesofexaminingeffects‐basedrelationships,NOxandammonianitrogenshouldnotbecombinedintoasinglevariable,asthetwoaremeasuringdifferentaspectsofthepollutiongradientTherewasinsufficientdatatoseparatetheNstressorsandEPAguidancefocusesontotalspecies.21|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse82Reviewer35Ch.622NOxshouldbeincludedintheregressionsinlieuofotherexpressionsofcross‐correlatednitrogengiventheworkpresentedinChapter4TherewasinsufficientdatatoseparatetheNstressorsandEPAguidancefocusesontotalspecies.83Reviewer35Ch.622ChangepointanalysisalongaNOxgradientshouldbedoneusingtheresidualvariationinbiologicalmetricsfollowingregressiononconductivity,colorandammonianitrogenProposedcriteriaarenotbasedonstressor‐response,giventhelimitationsofdataandvariabilityinrelationships,buttheseanalyseswereconducted.ThisisdetailedintheTSDforEPA’sproposedrule.84Reviewer35Ch.622Wideconfidenceintervalsresultingfrombootstrappingduringchangepointanalysisshouldnotbeconstruedasalimitation,butratherthemedianchangepointsfoundforeachmetricshouldbeconsideredinaggregateProposedcriteriaarenotbasedonstressor‐response,giventhelimitationsofdataandvariabilityinrelationships,buttheseanalyseswereconducted.ThisisdetailedintheTSDforEPA’sproposedrule.Wideconfidenceintervalsarealsoindicatorsoflackofsignificantchangepoints(SeeQianetal.citations).22|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse85Reviewer35Ch.623Quantileregressionappliedtowedge‐shapeddatasetsshouldbeusedtoidentifyasubsetofdatathatisrespondingtoagradientofinterest.Thetwodatasetscanthenbecomparedtohelpunderstandthesecondarygradients,andtoperformdirectgradientanalysisonthedatathatarerelativelylessinfluencedbythesecondarygradient(s).Proposedcriteriaarenotbasedonstressor‐response,giventhelimitationsofdataandvariabilityinrelationships,buttheseanalyseswereconducted.ThisisdetailedintheTSDforEPA’sproposedrule.86Reviewer35Ch.623ThereportisvaguewithrespecttowhichdataareusedfortheSCIregressionsProposedcriteriaarenotbasedonstressor‐response,giventhelimitationsofdataandvariabilityinrelationships,buttheseanalyseswereconducted.ThisisdetailedintheTSDforEPA’sproposedrule.87Reviewer35Ch.623Thesamplesizeof~75appearsrathersmallAnalysescouldonlybeconductedtotheextentpracticablegivendatalimitations.88Reviewer35Ch.623Werethesedatacollectedprospectivelyalonganutrientgradient,randomlyselected,ortheresultofadataculltoremovespurioussitesfromexistingdataAcombinationofdatawereused.23|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse89Reviewer55Ch.624Theanalysisofdose‐responsecharacteristicsofnutrientenrichmentonmacroinvertebrates,periphytonabundanceandchlorophyllaconcentrationsyieldedambiguousresults.Thehighdegreeofvariabilityintherelationshipsrenderedtheestablishmentofwell‐constrainedquantitativerelationshipsuntenable.Seecomment3390Reviewer55Ch.624Itislikelythattheutilityofapplyinganalysisofmacro‐invertebratesinrelationtonutrientstodeterminedose‐responsecurvesthatcanbeusedtoestablishquantitativecriteriaisofdubiousvalueSeecomment3391Reviewer55Ch.624LookingathighertrophiclevelsasafirstcutandasameanstodeterminenutrientcriteriaisnotlikelytobeeffectivebeyonditsutilityasascreeningtoolSeecomment3324|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse92Reviewer16Ch.724Hasaproblemwithsettingupreferencebenchmarkswithinregionsduetothelargeamountofvarianceassociatedwithanybiologicaland/orwaterchemistrymeasurementsBenchmarkdistributionsnotusedforEPA’sproposedcriteria.Inaddition,varianceconcernscontributedtotheselectedpercentiles.ThisisoutlinedintheTSDforEPA’sproposedrule.93Reviewer16Ch.725TheselectionprocesslistedinChapter7couldcausetheeliminationoflakesfromthedatabasethataretrulynotimpactedanditcouldalsocausetheselectionofriversthatareuniqueandnotreallyrepresentativeoftheindividualEcoregionBenchmarkdistributionsnotusedforEPA’sproposedcriteria.Theapproach,isoutlinedintheTSDforEPA’sproposedrule.25|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse94Reviewer16Ch.725RecommendanapproachofmodelingwhatfactorsaccountforthemostvarianceinbiologicalmeasuresandnutrientsconcentrationswithinindividualEcoregionsandtheplottheresidualagainstmeasurementsofpotentialofanthropogenicimpacts(LDI).Anyrelationsorbreakpointsbetweentheresidualsandmeasuresofpotentialanthropogenicimpactsmayhelppointtoanutrientstandard.Developingmodelstopredict(diatom)bioandnaturalchemicalandnutrientconditionswasdiscussedattheFDEPSDIdevelopment.Whileattractive,themodelswouldrequireastheirbaseamodelthatpredictsnatural,referenceconditionalkalinityandpHofthestream(andlakeifextendedtolakes).Consensuswasthatappropriatedatacurrentlydonotexisttodevelopsuchmodels.95Reviewer26Ch.725DefineWBIDupfrontinthischapterThiswasdonefortheTSDforEPA’sproposedrule.96Reviewer26Ch.725Astonaturalvariabilityinabenchmarkstream,oneaspectthatmaynothavebeenconsideredistidalactioninfreshwaterstreamsBenchmarkdistributionsnotusedforEPA’sproposedcriteria.Inaddition,varianceconcernscontributedtotheselectedpercentiles.ThisisoutlinedintheTSDforEPA’sproposedrule.26|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse97Reviewer26Ch.725StreamsinFloridacanhavenaturallylowpHandDOconditionsandthusthesewatersshouldnotbeexcludedasreferencesitesBenchmarkdistributionsnotusedforEPA’sproposedcriteria.Inaddition,varianceconcernscontributedtotheselectedpercentiles.ThisisoutlinedintheTSDforEPA’sproposedrule.98Reviewer36Ch.726Acarefulexaminationofthesiteswheregoodbiologyandhighnutrientlevelsintersectshouldbedonewithaneyetowardidentifyingmitigatingfactorslikecanopycover,localstreamgradient(i.e.,slope),substratecomposition,theformofnutrientresultinginthehighconcentration(e.g.,wetland‐derivednitrogenvs.nitratefromgroundwater),etc.Seeresponsetocomment92.99Reviewer36Ch.726NeedtoexaminethedistributionsofnutrientconcentrationswithincategoricalrangesoftheSCI(orsomeotherbiologicalmeasure/metric)forbenchmarksitesandforallsitesbyregionSeeresponsetocomment97.Inaddition,EPAisunsureofthevalueoftheproposedanalysis.100Reviewer46Ch.726Settingthethresholdat0.35mg/LpresumesadoptionoftheproposedcriterionNotechnicalresponsenecessary.27|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse101Reviewer46Ch.726TheexclusionofsiteswithSCI<40reflectstheassumption,alreadymentionedabove,thatimpairedequals“notreference.”Anin‐depthanalysisoferrorsassociatedwithdifferentSCIthresholdsisincludedintheTSDforEPA’sproposedrule.102Reviewer46Ch.726Reservationsaboutequating“representativeness”withaminimizationofvariabilityinthebenchmarksetNotechnicalresponsenecessary.103Reviewer46Ch.726ExclusionofnutrientoutliersistroublingastheyimprovetherepresentativenessoftheremainingsitesOutlieranalysiswascarefullydocumentedandjustifiedintheTSDforEPA’sproposedrule.104Reviewer56Ch.727Weaknessesinclude:Lackofmechanisticunderstandingofprocessesunderlyingthepatterns,lackofpredictability,lackofinclusionoffarfieldeffectsdownstreamNotechnicalresponsenecessary.28|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse105Reviewer56Ch.727Continuedassessmentoftheeffectivenessofthesecriteriathroughstandardizedperformancemeasuresiscriticalindeterminingvalidity.Performancemeasuresarenotconsideredinthisdocumentanditisarecommendationthatarigorousprotocolofevaluationbeimplemented.Nocommentnecessary.Unrelatedtotechnicalderivation.106Reviewer17Ch.827ThisnutrientlongitudinalstudyfocusesononlynutrientconcentrationsandnotnutrientloadsAnalysisfromthischapternotconsideredinthefinalcriteriaderivation.107Reviewer17Ch.828AddingthedatathathasalreadybeencollectedtodischargevaluesandusingtheVollenweiderapproachdescribedinSection14wouldallowthepredictionofthechangeinthenutrientconcentrationoftheriverneededtocauseasignificantchangeinthebaysAnalysisfromthischapternotconsideredinthefinalcriteriaderivation.29|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse108Reviewer37Ch.828ItwouldbereallyhelpfultomeldtheresultsofChapter8withthoseofChapter14,includingdoingamodelofnitrogenloadingfortheWaccasassaandSteinhatcheeestuariesforcomparison(andvalidation)totheotherspresentedinChapter14Analysisfromthischapternotconsideredinderivingtheproposedcriteria.Inaddition,EPA’sestuarinecriteriaeffortisincorporatingmodelrevisionandalternativemodelsintotheestuarinecriteriaeffort,whichcanimpactDPV.109Reviewer37Ch.829AdescriptionoftheconditionofseagrassbedsintheestuarieslistedinTable10inChapter14shouldbecomparedtothosefortheWaccasassaandSteinhatcheeforcontextSeeresponsetocomment108.110Reviewer47Ch.829Althoughthelongitudinalstudiesshowedthatthetworiversandtworeceivingestuariesareminimallydisturbed,IwouldhesitatetoconcludethattheyconstituteproofofconceptSeeresponsetocomment108.111Reviewer47Ch.829ItdoesnotseempracticalonastatewidebasistoderivestreamcriteriathatareuniformlyprotectiveofusesineveryestuarySeeresponsetocomment108.Alsoestuarineprotectivecriteriaaregenerallyestuaryspecific,totheextentallowedbyavailabledata.30|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse112Reviewer47Ch.829Criteriashouldbesetseparatelyforstreamsandestuaries(orlakes)tobeprotectiveofusesineachsystemSeeresponsetocomment108.Separatecriteriaforestuariesarebeingdeveloped.PerCWAregulations,upstreamcriteriamustalso,however,ensuretheprotectionofdownstreamwaterqualitystandards.113Reviewer57Ch.829Thewindowonthesubjectissomewhatlimitedhereasthetwoestuariesselectedareinthesamegeographicarea,thesamebioregion,thesamenutrientregion,etc.Notechnicalresponsenecessary.114Reviewer57Ch.829Theanalysisisminimalintheextreme.Thesupportingevidenceofanunimpactedfishery,itsdescriptionoritshistoryisnon‐existent.Thereisnoexpositionofthetypeofseagrassinthedownstreamreceivingwaters,theSAVdensity,condition,itsantecedenthistory,ordocumentationofanychangeovertime.Seeresponsetocomment108.115Reviewer57Ch.830SuchassessmentsmightbeconsideredmoreascreeningtoolNotechnicalresponsenecessary.31|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse116Reviewer57Ch.830Therearemanyfactors,assumptionsandquestionsthatremainuntestedbythispilotstudyNotechnicalresponsenecessary.117Reviewer57Ch.830Generalunderstandingofestuarinecirculationandcoastalwatermasstransport,ifnotoutrightcirculationmodeling,willberequiredinmanycasesfortrueassessmentofnutrientfateandtransportanddownstreameffectsSeeresponsetocomment108118Reviewer57Ch.830Non‐linearresponseofdownstreamsystemstoupstreaminputsmayresultinrapidcrossingofthresholdsortippingpointsearlierinthenutrientloadingtrajectorythanexpectedSeeresponsetocomment108.Thiscommentisbeingincorporatedintoongoingestuarinecriteriaendpointdevelopmentbyconsideringalternativeendpointmodels.119Reviewer57Ch.830Eachdistinctivewaterbody(stream,lake,estuary,spring,river)shouldbeassessedinitsowncontextforresponsetonutrientcriteriaSeeresponsetocomment112.Separatecriteriaaredevelopedforeachwaterbodytype,butcriteriaaddressdownstreamwaterbodyuses.120Reviewer18Ch.930TrophicstatescaleasoriginallydefinedisagradientwithoutarealbreakpointsoIhavealwayshaddifficultywithoneindividualchlorophyllnumberasastandardNotechnicalresponsenecessary.32|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse121Reviewer18Ch.930Colorcanbecomeaproblemwiththisproposedchlorophyllstandardsbecausewithonerainfallcolorcanchangefromlowtohighwithonerainfallshiftingthechlorophyllstandardfrom10to20μg/lwhichisahugedifferenceSeeresponsetocomment7122Reviewer18Ch.930UsingspecificconductancetogetatdifferencesbasedongeologyisconceptuallyagoodideabuttherearemanylakesinFloridanearthecoastthathavehighspecificconductancebecauseofsaltwaterinterferencesSeerespondtocomment3.123Reviewer18Ch.931ProposedchlorophyllstandardsalsodonottakeintoaccounttheabundanceofaquaticplantswithinindividuallakesAquaticplantswereconsideredvisavistheLVIindex,whichwasfoundtobeapoorresponder.Revisionstothechlorophylltargetsweremadebasedonthesecomments.TherevisionsaredetailedintheTSDforEPA’sproposedrule.33|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse124Reviewer18Ch.931AlmostallofFlorida’sexceptionalfishinglakeswouldhavechlorophyllconcentrationsexceeding20μg/Lmakingthemimpairedonpaper.ThisisonereasonwhyImentionedinmygeneralcommentsthatFloridaFishandWildlifeConservationCommissionneedstobeinvolvedwithsettingnutrientstandardsSeeresponsetocomment1125Reviewer18Ch.931TheapproachthereviewerlikedthemostthatwasreviewedinthedocumentistheonetakenbyAlabamaofmaintainingtheexistingcondition.Takingtheabundantlong‐termdatathatisnowavailableanddefiningnormalbackgroundvariancewouldbeagoodwaytosettingachlorophyllstandard.Long‐termdataisavailableforonlyafewlakesinFlorida,relativetothelargerregionaldatasetsandthislimitsapplicabilityofthisapproach.Revisionstothechlorophylltargetsweremadebasedonthesecomments.TherevisionsaredetailedintheTSDforEPA’sproposedrule.126Reviewer28Ch.931Astotheuseofpaleolimnologicalstudies–reviewerdoesnotsupporttheirusetosetnumericcriteriaThesestudiedsupportandinformthecriteriabutwerenotusedtodevelopit.TherevisionsaredetailedintheTSDforEPA’sproposedrule.34|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse127Reviewer28Ch.932Astobiologicalresponses,DEPshouldconsiderwhatwouldbetheimpactofchlorophyllaonbiochemicaloxygendemand,potentiallydevelopingregressionequationsforBODasresponsevariabletochlorophyllaDatalimitationsprecludethedevelopmentofthemodelsdescribed.128Reviewer38Ch.932Apresentationofhowtheequationslistedonpage126werederived(scatterplots,statisticaloutput,etc.)wouldhavebeenhelpfulTherevisionsbasedonthiscommentaredetailedintheTSDforEPA’sproposedrule.129Reviewer38Ch.932Thesectionrelatingcyanobacteriaabundancetochlorophyllalevelsofferedlittletowardsunderstandingeffectsofnutrientenrichment.Abetterapproachwouldbe,wheredataareavailable,tolookattrendsincyanobacteriaabundanceovertimeforselectedlakeswherenutrientconcentrationshaveincreased.Datalimitationsprecludethedevelopmentofthemodelsdescribed.130Reviewer38Ch.932TheresultsfromChapter9shouldbemeldedwiththosefromChapter10ThiscommentwasconsideredandtheTSDforEPA’sproposedrulereflectthesuggestion.35|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse131Reviewer48Ch.933Itisnotclearwhatroleexpertopinion(i.e.,whatotherstateshavedone)shouldplayinviewoftheotheroptionsavailable,unlessitisamatterofseekingreassuranceinsimilarconclusionsNocommentnecessary.132Reviewer48Ch.933InformationattributedtoColoradoismistakenbecausenoproposalshavebeenmadeyetfornutrientcriteriaThiscommentwasconsideredandtheTSDforEPA’sproposedrulereflectthesuggestion.133Reviewer48Ch.933CriteriadevelopedforfisherysupportmaynotbeuniformlycompatiblewithallusesinotherstatesNotechnicalresponsenecessary.134Reviewer48Ch.933WhatapproachwouldFloridataketobalancefisheryandaestheticconsiderationsifthesewerefoundtobeinconflict?Seeresponsetocomment1.135Reviewer48Ch.933Maintenanceofexistingconditions:applicabletosite‐specificcriteriadevelopment,difficulttoseehowitwouldaddressuseprotectiononthestatewidelevelNotechnicalresponsenecessary.36|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse136Reviewer48Ch.933The[lake]referenceapproachismentionedonlybrieflyinthechapter.Supportingmaterialsshowthatmucheffortwasinvestedinthisapproach,whichalsoproducedrecommendationsfornutrientsandtransparency.However,asmentionedabove,developmentofcriteriawiththisapproachwouldhavetobereconciledwiththepaleolimnologicalinformation.”Thiscommentwasconsidered,thelakecriteriadescriptionwaseditedtoclarifyandtheTSDforEPA’sproposedrulereflectthesuggestion.137Reviewer58Ch.934The90thpercentileofreferenceconditionsfornutrientcriteriaisareasonablealternativebuttheevidenceforitsuseisnotpresentedinthischapterBenchmarkpercentileapproachforlakeswasnotusedinthefinalcriteriaderivation.138Reviewer58Ch.934p.124:Notemisleadingsentencestructure:Floridalakesdonothavecool‐waterfisheries(true)butdohaveoxygenatedhypolimnia(contrarytotheimplication)Editsmadetoclarify.37|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse139Reviewer19Ch.1034Concernedandnotsurewehavetheabilitytoeasilyclassifylakesintothecolorand/orconductivitygroupsthatarebeingrecommendedSeeresponsetocomment7140Reviewer19Ch.1034UsingOkeechobeecolordataasanykindofamodelforotherlakesinthestateisnotappropriatebecausetherearenootherlakesinthestatelikeOkeechobeeFinalanalysisdoesnotrelyonanyonelakeforcriteriaderivation.141Reviewer19Ch.1034Using40PCUasthecutoffforcoloredandclearlakescanbeadifficultboundarytoreallydefineSeeresponsetocomment7142Reviewer19Ch.1034Muchmoreworkneedstobedonewithlong‐termdatatobetterdefinethelakegroupsbasedoncolorandconductivitySeeresponsestocomments3and7.143Reviewer29Ch.1036p.135,line5;itstatesthatlakevegetationexhibitedasignificantadverseresponsetonutrients.Actuallyitwasapositiveresponse(thoughweak).LakevegetationandtheLVIwerenotusedinderivingthefinalcriteria,basedinpartontheissueidentifiedinthiscomment.38|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse144Reviewer29Ch.1037The9μg/Lresponsecriterionfortheclear,lowconductivitylakesistoohigh.Wouldfavorachlorophyllaresponsecriteriaof5μg/Lforclear,lowconductivityFloridalakes.Notechnicalresponsenecessary.145Reviewer39Ch.1037UsingtheresidualsoftheLVIfollowingregressiononcolorandconductivityinchangepointanalysisoveragradientofTNorTPshouldbetriedSeeresponsetocomment143.146Reviewer39Ch.1038Evaluatetheproposedclassificationandsub‐classificationapproachforlakes:aseparateslopesregressionmodelwouldhelphereSeeresponsetocomment3147Reviewer49Ch.1038Itisnotclearwhatactionwouldbetakenifchlorophylliswithinbounds,butoneorbothnutrientsexceedtheupperthreshold(lowerpredictioninterval)Thecommentisaddressedintheimplementationofthecriteriaintheproposedrulelanguage.148Reviewer49Ch.1038Clearandcoloredcategories:itisnotapparentifalllakescaneasilybesegregatedintothosetwogroups,orifthereisanunbrokencontinuumoflakesSeeresponsetocomments3and739|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse149Reviewer49Ch.1038LessinformationispresentedregardingthemeritsofconductanceasanadditionalclassificationvariableThiscommentwasconsideredandthelanguageregardingtheutilityofconductivitywasimprovedtomatchtheconcern.However,conductivitywasnotusedindevelopingtherule.150Reviewer49Ch.1038ItmightbeinterestingtolearnmoreabouttheTAC’sreasoningregardingthe100umho/cmdividingline,butreviewerdoesn'thaveanyparticularreservationsaboutacceptingtheirconclusionNotechnicalresponsenecessary.151Reviewer49Ch.1038Fortheindependentapproachesfordevelopmentofcriteriabasedonchlorophyllorlakevegetation,arethetwoapproachesdrawingonthesamesetoflakes?Wheredatawerecoincident,lakeswillhaveprovidedbothsetsofdata.152Reviewer49Ch.1038Aplotofchlorophyllvs.LVIhelpfulSeeresponsetocomment143.153Reviewer59Ch.1039Whendatashowthatnutrientsarewithinincomplianceofestablishedcriteria,yetchlorophyllacriteriaareexceeded,thenonewouldexpectthatnutrientreductionswouldhavetobeundertakenSeeresponsetocomment147.40|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse154Reviewer59Ch.1039RecommendationforinvestmentinadditionalresearchintoecologicalrelationshipsandevaluationofsystemsorclassesofsystemsandtheirdrivingprocessesNotechnicalresponsenecessary.155Reviewer110Ch.1140EcoregionconcepttoformthebaseforanalysesisagoodstartthatneedstobeusedthroughoutthedocumentSeeresponsetocomment3.Regionalizationbeganwithecoregionsandthenwereexpandedorrefinedappropriately.Allstreamsanalysiswasnotusedasthebasisfortheproposedcriteria.156Reviewer110Ch.1140Physicalfactorsdominatemostaspectsofstreambiologyandovershadowimpactsofnutrients.ForthisreasonthereviewerhadahardtimewiththisapproachtosettingstandardsSeeresponsetocomment6157Reviewer110Ch.1140Nomatterwhatpercentageofthedatadistributionyouuseforastandard,somestreamsthataremeetinguseandfunctioningfinewillbeconsideredimpairedAnalysisandtextonbalancingerrorsassociatedwiththeconcernpresentedwereaddedtotheTSDforEPA’sproposedrule.Allstreamsanalysiswasnotusedasthebasisfortheproposedcriteria.158Reviewer210Ch.1140TheoutlierremovalprocesscoulduseabitoftweakingSeeresponsetocomment103.Allstreamsanalysiswasnotusedasthebasisfortheproposedcriteria.41|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse159Reviewer210Ch.1140ConcernedaboutusingTNof100mg/LandTPof15mg/Lasscreeningthresholds,thesethresholdsaretohighScreeningthresholdsweretweakedappropriately,butseealsoresponsetocomment103.Allstreamsanalysiswasnotusedasthebasisfortheproposedcriteria.160Reviewer210Ch.1140DEPkickedoutdatawhentherewere4orlessobservationswithinayear.However,alotofvariabilitycanoccurwithonly5or6samplesaswell,bothseasonalandevent‐driven.Reviewersuggesteddrawingthelineat8observationsorlessasyearasacutoffpointfordatasets.Droplossof8sampleswasconsideredandanalysisconducted.However,finalruleswerebasedonoriginalcriteria.Allstreamsanalysiswasnotusedasthebasisfortheproposedcriteria.42|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse161Reviewer310Ch.1140Descriptivestatisticsarenecessaryforabroadunderstandingofsystemsatthepopulationlevel.However,thereferenceapproach,intheabsenceofbiologicaldata,providestheweakestlineofevidenceforcriteriadevelopment.Theallsiteschemistrydatashould,emphatically,bepairedwithbiologicaldata(i.e.,theSCI,SDI,orasensitivecomponentmetric)andreexaminedwithinrangesofthebiologicaldata.Therevisedapproachisbasedonbiologicallyhealthystreams.Allstreamsanalysiswasnotusedasthebasisfortheproposedcriteria.162Reviewer410Ch.1141Becausereference(orminimallydisturbed)sitesseemreadilyavailableinFlorida,thereislittlemotivationtousetheallstreamsapproach.Itisnotreassuringtoknowthat“the25thpercentilefromtheAllStreamsdatawaslessthanthe75thpercentile...fromtheBenchmarkdataset.”Somereferencesitesstillwillbeclassifiedasimpaired.Therevisedapproachisbasedonbiologicallyhealthystreams.Allstreamsanalysiswasnotusedasthebasisfortheproposedcriteria.43|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse163Reviewer510Ch.1141Thisisasparechapterthatpresentsdatawithoutsignificantanalysis.Theinformationpresentedhereislackingrecommendationorinterpretation.Theallstreamsanalysiswasusedinexploratoryanalysisbutwasnotusedasthebasisfortheproposedcriteria.164Reviewer510Ch.1141Itwouldhavebeenanimprovementtopresentactualshapesofnutrientconcentrationfrequencydistributionsgraphically,andspecificallywiththetwoalternativeapproachesoverlainforeachnutrientforeachnutrientregionThisanalysiswasconductedandusedinderivingfinalcriteria.Theallstreamsanalysiswasusedinexploratoryanalysisbutwasnotusedasthebasisfortheproposedcriteria.165Reviewer510Ch.1141Thenextstepthatwouldhavebeenanticipatedwasnottakenhere‐thatisrelatingthenutrientthresholdsascalculatedusingAllStreamstovariousestimatesofstreamconditionaswasdonefortheotheralternatives,dose‐responseandnutrientbenchmarkdistributionalapproachThisanalysiswasconductedandusedinderivingfinalcriteria.Theallstreamsanalysiswasusedinexploratoryanalysisbutwasnotusedasthebasisfortheproposedcriteria.44|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse166Reviewer211Ch.1241‐42Chapter12citationsoftablesandfiguresdidnotmatchtheonessupplied.ItwasassumedTable1isactuallyTable12‐5,Figure1isFigure12‐3,Figure2is12‐2,andFigure4is12‐4.Notechnicalresponsenecessary.167Reviewer211Ch.1242Regardingthe9%increasebetween1995to2004,itcanbesafelyassumeditisduetoincreasedlandscapedevelopmentNotechnicalresponsenecessary.168Reviewer411Ch.1242ItseemsunfairtosaythattheDoddsandOakesmethoddidn’twork(“candidatenutrientcriteriacouldnotbereliablyderivedusingtheDoddsandOakes(2004)methodsasappliedherewiththeavailabledata”);itwasnotgivenanadequatetestbecause,asstatedinthereport,therequireddatawerenotavailableInpart,theweaknessoftheapproachisbasedonlackofavailabledata.Thisanalysiswasnotusedinthefinalcriteriaderivation.169Reviewer411Ch.1242TheefforttoderivebackgroundconditionsbasedontheLDIrelationshipseemedperfunctoryinviewoftheverypromisingresultspresentedpreviouslyinthereportSeeresponsetocomment168.45|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse170Reviewer112Ch.1343Reviewernotcomfortablewithsettingstandardsbasedonapercentageofadistributionofdata.Therearetoomanylakesthatarefunctioningwellandmeetingusesthatwillbeconsideredimpaired.Finallakecriteriaarebasedonstressor‐responseanalysesanddownplaydistributionanalysis.171Reviewer112Ch.1343Withoutmoreworkonlong‐termcolordatainlakes,reviewerisuncomfortablewiththeseparationoflakesintocoloredandclearlakesbasedonameasuredcolorof40PCUSeeresponsetocomment7.172Reviewer212Ch.1343Editingremark–page175,middle,Figure2shouldreadFigure13‐3Notechnicalresponsenecessary.173Reviewer212Ch.1343p.182–therearesomeissueswiththeOutliersandInvalidData.Nitrateiskickedoutifitisabove75mg/L,yetTNiskickedoutifitisabove20mg/L–adisconnecthere.DEPneedstobringthisexpulsioncriterionforTNdownto20or25mg/L.Theseconcernedwereincorporatedintosubsequentanalysis.46|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse174Reviewer212Ch.1343Astochlorophylla,thehighestlevelseenbythereviewerinabloomis400μg/L,whileDEPisusing1,000μg/Lasacriterion.Suggestcuttingthatwaydowntoatleast<400μg/L.Themultiplelinearregressionapproachwasnotusedinderivingtheproposedcriteriaforlakes.175Reviewer212Ch.1343AstoSecchidepth,notawareofFloridalakesthatare50mdeep,sowhyuseaSecchiof50mtokickoutanoutlier?Howabout10m?Themultiplelinearregressionapproachwasnotusedinderivingtheproposedcriteriaforlakes.176Reviewer212Ch.1343Suggestusingalowerlimitof8samplesinayeartocreateamean,withsamplestakenseasonallytocollectlower‐impactperiodsaswell.Seeresponsetocomment160.177Reviewer412Ch.1344Placementofthediagonalline(nowsettothe“averageratiobetweenln(TN)andln(TP)”)deservesmoreattentionbecauseitmakesanimportantstatementaboutthenutrientregime..Theratiousedinthegraph(0.588/0.013=45:1)isveryhighandindicativeofaphosphorus‐limitedsituation.Placementofthediagonallinemightbeadjustedaccordingtoexpectationsforaparticularregion.ThisconcernwasconsideredbyEPAinthefinalanalysisandalternativeanalysisusedtoaddressit.Themultiplelinearregressionapproachwasnotusedinderivingtheproposedcriteriaforlakes.47|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse178Reviewer412Ch.1344Whyarethedistributionalstatisticsforlakesdeterminedonastatewidebasiswhenthereareidentifiablegeographicpatternsforphosphorusandnitrogeninstreams?Distributionalstatisticswerenotusedinderivingtheproposedlakecriteria.179Reviewer512Ch.1344Itiscuriousthattheentirepooleddatasetinfigure13‐4showsindividuallakeswithinthepoolseemtotrendtoalowerslopethantheslopeofallpooledobservations.Thisisnotdiscussedinthetext.SlopecomparisonsweremadeinsubsequentanalysesandaredetailedintheTSDforEPA’sproposedrule.180Reviewer113Ch.1445ModelingeffortsaccomplishedinSection14shouldbedoneusingphosphorusinsteadofnitrogen.Pwasanalyzedaswell.Responsesofbothnutrientsaresimilar.SeetheTSDforEPA’sproposedrule.181Reviewer213Ch.1446p.188:“intheabsenceofmorespecificinformationitmaybeappropriatetoreducetheanthropogeniccontributionoftheTNloadtoestuariesbyaconstantfraction.”Thisisnotappropriate.Thereisno“onesizefitsall”solutionforecologicalproblemssuchasthis.Intheabsenceofsitespecificnutrientuptakeparameters,appropriateestimateshavetobelevied.Estuarinemodelsarebeingreviewedtoupdateasmuchofthemodelcharacteristicsaspossible.48|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse182Reviewer213Ch.144614.1.18‐AnotherconcernIhaveisthatofthecontributionofsepticsystemstothenutrientloadinestuarinewaters.WhileDEPcertainlyaccountsfordirectpointsourcecontributionsofnutrientstoestuariesintheirmodels,itisknownfromresearchintheCarolinasthatnutrientsfromsepticsystemsdirectlyenterestuarinewatersaswell(Cahoonetal.2006).Thiscommentwasconsideredinsubsequentanalysis.SeetheTSDforEPA’sproposedrule.Thiscommentwillalsobeincorporatedintosubsequentestuarinecriteriaefforttotheextentpracticable.183Reviewer213Ch.1447Thetideisanimportantconsiderationinobtainingaccuratemeasuresofnutrientloadingtodownstreamwaters.Thiscommentwasconsideredinsubsequentanalysis.SeetheTSDforEPA’sproposedrule.Thiscommentwillalsobeincorporatedintosubsequentestuarinecriteriaefforttotheextentpracticable.184Reviewer313Ch.1447Theapproachwouldbemorecompellingiftheexamplesforintactsystems(aspreviouslynoted)wereincludedforcomparisonsNotechnicalresponsenecessary.185Reviewer313Ch.1447ItwouldhavebeennicetoseetheVollenweiderexampleworkedoutforafewlakes.TheexampleprovidedisactuallyforaveragelakeconditionsandrepresentstheconditionforthemajorityofFloridalakes.49|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse186Reviewer413Ch.1448Whilethereisnoconceptualreasonwhythemodelcouldnotbeappliedtolakesaswellasestuaries,theremaybeapracticallimitationtothelowerboundongeographicscaleNotechnicalresponsenecessary.187Reviewer413Ch.1448Thereisafundamentalquestionaboutlinkingattainmentinestuarieswithattainmentintributarystreams.Notechnicalresponsenecessary.188Reviewer413Ch.1448ForSPARROW,itisnotclearifthelinkageincludescontributionsofnitrogengeneratedbythemarshgrasseswithintheestuary.Thiscommentwasconsideredinsubsequentanalysisandtext.SeetheTSDforEPA’sproposedruleforclarificationonthedetailsoftheSPARROWmodel.Thiscommentwillalsobeincorporatedintosubsequentestuarinecriteriaefforttotheextentpracticable.189Reviewer413Ch.1448ThesectiononlakemodelingissobriefthatitishardtoevaluateTheTSDforEPA’sproposedrulehasamoreexpandedlakemodelingsection.190Reviewer413Ch.1448‐49Justlikeestuaries,thereisafundamentalissueaboutthelinkagebetweenconcentration‐basedstandardsinlakesandinthetributarystreamsNotechnicalresponsenecessary.50|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse191Reviewer513Ch.1449WhilethemodelshowspromiseasatoolforestimatingNloadstomanyFloridaestuaries,itisimportanttonotethatseveralFloridaestuarieswouldbeinappropriateastargetsforSPARROWmodeling.Largeinteractionofsurfaceflowswithgroundwaterflows,thelackofmassfloworwell‐constrainedpoint‐sourceinput,andmultipleungaugedinputswouldrendersuchmodelingineffective.Thiscommentwasconsideredinsubsequentanalysisandtext.SeetheTSDforEPA’sproposedruleforclarificationonthedetailsoftheSPARROWmodel.Thiscommentwillalsobeincorporatedintosubsequentestuarinecriteriaefforttotheextentpracticable,andavarietyofmodelsarebeingconsideredinadditiontoSPARROW.192Reviewer513Ch.1449Thereisaneedalsotoevaluatethespatialheterogeneityofreceivingwaters,particularlyinestuariesThiscommentwasconsideredinsubsequentanalysis.SeetheTSDforEPA’sproposedrule.Thiscommentwillalsobeincorporatedintosubsequentestuarinecriteriaefforttotheextentpracticable.193Reviewer513Ch.1449AdaptationofSPARROWanalysistothesub‐estuaryscaleiswarrantedTherearelimitationstothespatialapplicabilityofmodels.SeetheTSDforEPA’sproposedruleforclarificationonthedetailsoftheSPARROWmodelapplication.Thiscommentwillalsobeincorporatedintosubsequentestuarinecriteriaefforttotheextentpracticable.51|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse194Reviewer513Ch.1449ThereisminimaldiscussionofimplementationofVollenweidermodelpresentedSeeresponsestocomment185.ThissectionhasbeenexpandedfortheTSDforEPA’sproposedrule.195Reviewer513Ch.1449Someaspectsofwatershedmanagementarenotadequatelyaddressed.Thetotalloadingratecanbecalculated,butthelakewouldbereceivingloadingfrommultiplesources,bothpointandnon‐point.Anyactiontakenwouldbedependentonthesource(s)ofthenutrientandabalancingofthesourcereductionsnecessarytoachievecompliance.Howthatwouldbeapportionedorevendeterminedamongthesourcesisleftforlaterexposition.Notechnicalresponsenecessary.196Reviewer513Ch.1450Simplemodelswillworkwellasaprimaryscreeningtoolasappliedtoindividuallakeswithwell‐constraineddatasetsandboundaryconditionsbutthereisalargeuncertaintyassociatedwithdemandingtoomuchpredictivecapabilityfromthem,especiallywhenusedto“batchprocess”theinformationforgroupsoflakesNutrientcriteriaarebeingdevelopedonaregionalbasisbecauseresourcerequirementsprecludelakebylakecriteriadevelopment.Thesamelimitationsapplytomostregionalcriteriaderivationefforts.52|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse197Reviewer1AdditionalComments51GivingreviewersmuchmoretimeandevenchancestoquestiontheoriginalauthorswouldleadtoamuchstrongerfinaldocumentNotechnicalresponsenecessary.198Reviewer5AdditionalComments51Overall,thedocumentisamixedresultduetoseveralmethodologiesintheprocessofbeingdeveloped;lackofstatewideapplicabilityandthemosteffectivecurrentmethodologyforstreamstheSCIasagoodfunctionalbaselinefromwhichtostartNotechnicalresponsenecessary.199Reviewer5AdditionalComments51Dose‐Responseanalysesprovedunsatisfactoryyetshould,withadditionalresearchandinformationdevelopment,holdpromiseNotechnicalresponsenecessary.200Reviewer5AdditionalComments51MethodstodeterminewhethertheupstreamcriteriaareprotectiveofdownstreamwatersareinsufficientlyevaluatedinthisdocumentThedownstreamprotectionanalysishasbeenimprovedandthesectionexpandedfortheTSDforEPA’sproposedrule.53|PageCommentNumberReviewerQuestionDocumentChapterPeerReviewDocumentPageSummarizedComment/EditEPAResponse201Reviewer5AdditionalComments52TheSPARROWmodelshouldbeappliedcautiouslyandonlytoappropriatesystemsinassessingdownstreameffects,namelythosewithwell‐definedchannelflows,andwell‐especiallytoreceivingreachesandcoastalwatersThiscommentwasconsideredinsubsequentanalysisandtext.SeetheTSDforEPA’sproposedruleforclarificationonthedetailsoftheSPARROWmodel.ThiscommentwillalsobeincorporatedintosubsequentapplicationofSPARROWtotheestuarinecriteriaefforttotheextentpracticable.202Reviewer5AdditionalComments52Documentmostlylacksisanoverallorientationandstrategy,asetofclearrecommendations,andanimplementationplanforbringingthesevariousapproachestobearTheorientationandstrategyisclarifiedintheTSDforEPA’sproposedrule.203Reviewer5AdditionalComments52Determinationoftheboundariesofanalysis,ofwhatprotocoltakesprecedence,wheneachwouldbeapplied,whereeachisapplicable,howdataandresultsaretobesynthesizedtoarriveatcriteriaiswantingCommentsareaddressedintheTSDforEPA’sproposedrule.