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Home My WebLink AboutMadaket Harbor and Long Pond Draft TMDL November 17, 2011 Presentation_2014012309163761992Restoring and Preserving Restoring and Preserving Water Quality inWater Quality inthetheMadaket Harbor and Long Pond Madaket Harbor and Long Pond Estuarine SystemEstuarine SystemGuided byGuided byNitrogen Control StrategiesNitrogen Control StrategiesMassDEPNovember 17, 2011 3Information Sources and Information Sources and ParticipantsParticipants•• Town of NantucketTown of Nantucket•• UMASS Dartmouth School of Marine UMASS Dartmouth School of Marine Science & Technology (SMAST)Science & Technology (SMAST)•• Applied Coastal Research and Applied Coastal Research and Engineering, Inc.Engineering, Inc.•• Cape Cod CommissionCape Cod Commission•• USGSUSGS•• US EPAUS EPA•• MA Division of Marine FisheriesMA Division of Marine Fisheries•• MassDEPMassDEP 4The ProcessLinked Model & Report:Nitrogen LoadingHydrodynamic ModelWater Quality ModelThresholds AnalysisWatershed DelineationLand Use DataData CollectionTMDL DevelopmentCWMP & more model runsImplementation! 5The Problem:The Problem:Declining coastal habitat quality due to increased nitrogen loading resulting from changes in watershed land usesDeclining coastal habitat quality Declining coastal habitat quality due to due to increased nitrogen loadingincreased nitrogen loading resulting from resulting from changes in watershed land useschanges in watershed land uses 6 7Figure developed by: Three Bays Preservation, Inc, Stearns & Wheler Engineers, and Horsley & Witten Group 8Effects of Excess NitrogenAlgae BloomsLoss of EelgrassIncreased Macro-AlgaeLow Dissolved OxygenOrganic Enrichment of SedimentsLack of Plant & Animal DiversityFish KillsEffects of Excess NitrogenEffects of Excess NitrogenAlgae BloomsAlgae BloomsLoss of EelgrassLoss of EelgrassIncreased MacroIncreased Macro--AlgaeAlgaeLow Dissolved OxygenLow Dissolved OxygenOrganic Enrichment of SedimentsOrganic Enrichment of SedimentsLack of Plant & Animal DiversityLack of Plant & Animal DiversityFish KillsFish Kills 9EPA requires states toEPA requires states to set limits* on pollutantsset limits* on pollutants* Total Maximum Daily Load (TMDL) 10Total Maximum Daily Load:Total Maximum Daily Load:Maximum amount of a pollutant Maximum amount of a pollutant that can enter a water body that can enter a water body and still meet water quality and still meet water quality standards standards 11 12MEP GoalsMEP GoalsDetermine:Determine:Nitrogen Loading Limits Nitrogen Loading Limits –– specific specific to individual estuarine systems in to individual estuarine systems in Southeastern MassachusettsSoutheastern MassachusettsRecommend:Recommend:Nitrogen Management StrategiesNitrogen Management Strategies 13SMASTSMAST’’ss Linked Models Linked Models Approach Establishes:Approach Establishes:Nitrogen Criteria for Each EstuaryNitrogen Criteria for Each EstuaryNitrogen Watershed Loading LimitsNitrogen Watershed Loading Limits 14Determining Present ConditionsDetermining Present ConditionsNitrogen Loading to GroundwaterNitrogen Loading to GroundwaterGroundwater Flow to EstuariesGroundwater Flow to EstuariesEstuary Circulation, Tides & CurrentsEstuary Circulation, Tides & CurrentsNitrogen Concentrations in EstuariesNitrogen Concentrations in Estuaries 15Target Threshold Concentrations & LoadsTarget Threshold Concentrations & LoadsN Concentration Targets are Linked to:N Concentration Targets are Linked to:Reduced Algal Blooms Reduced Algal Blooms (as measured by Chlorophyll(as measured by Chlorophyll--aa))Improved Dissolved Oxygen ConcentrationImproved Dissolved Oxygen ConcentrationHealthy Benthic Animal AssemblagesHealthy Benthic Animal AssemblagesEelgrass RestorationEelgrass Restoration 16Predicting Target Threshold Predicting Target Threshold Concentrations & LoadsConcentrations & Loads““TargetTarget”” nitrogen concentration applied to nitrogen concentration applied to estuaryestuaryGroundwater nitrogen flows to estuariesGroundwater nitrogen flows to estuariesEstuary circulation, tides, & currentsEstuary circulation, tides, & currentsNitrogen load (TMDL) to estuary is calculated Nitrogen load (TMDL) to estuary is calculated from the linked modelfrom the linked model 17Modeling the Options for Modeling the Options for Achieving the Target Threshold Achieving the Target Threshold Conventional Approaches:SeweringStormwater controlsFertilizer use reduction bylawsNon-traditional Approaches:Improved flushingEnhance natural attenuation 18Comprehensive Wastewater Comprehensive Wastewater Management Planning (CWMP)Management Planning (CWMP)Based on acceptable nitrogen loadingBased on acceptable nitrogen loadingIdentifies wastewater management optionsIdentifies wastewater management optionsSchedules implementationSchedules implementationWatershedWatershed--wide approachwide approach 19 20 21Sediment NitrogenSediment NitrogenIndirectly controlled by watershed Indirectly controlled by watershed nitrogen loadnitrogen loadA A ““pass throughpass through”” from other sourcesfrom other sourcesWill return if other sources are not Will return if other sources are not controlledcontrolled 22 23Observed Existing Nitrogen Concentrations and Target Threshold Concentrations for Madaket Harbor and Long Pond Observed Existing Nitrogen Concentrations and Target Threshold Concentrations for Madaket Harbor and Long Pond1 Average Total N concentrations from present loading based on an average of annual N means from 2002 – 20042 Target threshold N concentration at Hither Creek Sentinel Station M113 Secondary target threshold N concentration for Long Pond (average of stations LOP01, 02, 03, 04)Sub-embaymentRange of Observed Nitrogen Concentration 1(mg/L)Target Threshold Nitrogen Concentration(mg/L)Madaket Harbor0.336-0.422Hither Creek0.581-0.7800.452Long Pond0.894-1.0580.803 24M1M2M6M10M3M4M11M5LOP02LOP01LOP03LOP04LOP05Water Quality Sampling Stations in the Madaket Harbor Water Quality Sampling Stations in the Madaket Harbor and Long Pond Estuarine Systemand Long Pond Estuarine System 25Total Watershed Nitrogen Load, Target Load, and Percent Reduction Needed to Meet the Target Load Total Watershed Nitrogen Load, Target Load, Total Watershed Nitrogen Load, Target Load, and Percent Reduction Needed to Meet the and Percent Reduction Needed to Meet the Target LoadTarget LoadSub-embaymentPresent Total WatershedLoad 1(kg/day)TargetThresholdWatershedLoad2(kg/day)Percent Watershed Load Reductions Needed to Achieve TargetMadaket Harbor0.6630.6630%Hither Creek4.0411.13471.9%Madaket Ditch2.4332.4330%North Head Long Pond0.2380.2380%Long Pond3.2301.10165.9%Total for Madaket Harbor/ Long Pond Estuarine System10.6055.57047.5%1 Composed of septic, fertilizer, landfill and runoff loadings2 Target threshold watershed load is the N load from the watershed needed to meet the target threshold N concentration 26Comparison of sub-embayment watershed septic loads used for modeling of present and threshold loading scenarios in the Madaket Harbor System. Sub-embaymentPresentseptic load(kg/day)Thresholdseptic load(kg/day)Thresholdseptic load %changeMadaket Harbor0.3840.3840.0%Hither Creek2.9070.000-100.0%Madaket Ditch1.5101.5100.0%North Head Long Pond0.0710.0710.0%Long Pond0.3420.3420.0%System Total5.2142.307-55.8% 27Total Maximum Daily LoadTotal Maximum Daily LoadSub-embaymentTargetThresholdWatershed Load(kg N/day)Atmospheric Deposition(kg N/day)Nitrogen Load from Sediments(kg N/day)TMDL1(kg N/day)Madaket Harbor0.6638.60317.95227.218Hither Creek1.1340.53401.668Madaket Ditch2.433-0.0612.494North Head Long Pond0.2380.6930.995 1.926Long Pond1.1010.9752.2734.349Total for System5.57010.80521.28137.6561 Sum of target threshold watershed load, sediment load and atmospheric deposition load 28ImplementationWatershed-Wide FocusPrioritize Efforts“Technical” Approaches“Institutional” Approaches 29Technical ApproachesEnhanced Wastewater TreatmentStorm Water Runoff Control & TreatmentFlushing EnhancementsEnhanced Nitrogen Attenuation 30Institutional ApproachesLocal Zoning (guided development)BylawsCreative Financing- State Revolving Fund (SRF) can cover planning & construction- USDA Rural Development grantsSRF Points for a Wastewater Management District 31Implementation GuidanceDEP has Developed an Implementation Guidance ManualCompanion to technical reportsProvides an overview of tools that can be usedLooks at technical and institutional optionshttp://www.mass.gov/dep/water/resources/coastalr.htm#general 32Where Do We Go From Here?DEP: Revise TMDL Document (based on public input)Submit TMDL to EPAComprehensive Wastewater Management Planning (CWMP) 33For More Information:For More Information:EPAhttp://www.epa.gov/owow/tmdlMassDEPhttp://www.mass.gov/dep/water/resources/tmdls.htmMA List of Impaired Waters(303d is now the Integrated List)Draft and Final TMDLshttp://www.mass.gov/dep/water/priosres.htmEstuaries ProjectWatershed Assessment ReportsEPAhttp://www.epa.gov/owow/tmdlMassDEPhttp://www.mass.gov/dep/water/resources/tmdls.htmMA List of Impaired Waters(303d is now the Integrated List)Draft and Final TMDLshttp://www.mass.gov/dep/water/priosres.htmEstuaries ProjectWatershed Assessment Reports 34Questions/Comments on TMDLQuestions/Comments on TMDLBy Friday, December 16 at 5:00 pmBy Friday, December 16 at 5:00 pmchristine.duerring@state.ma.uschristine.duerring@state.ma.usMassDEPMassDEPDivision of Watershed ManagementDivision of Watershed Management627 Main Street, 2627 Main Street, 2ndnd FloorFloorWorcester, MA 01608Worcester, MA 01608Attention: Christine Attention: Christine DuerringDuerring