DRAFT Great Bay Total Nitrogen General Permit • Importance • Structure • Compliance • Costs • Opportunities • Risks • Next Steps March 2, 2020 DRAFT Great Bay Total Nitrogen General Permit 1
National Pollutant Discharge Elimination System (NPDES) Permits Total Nitrogen General Total Nitrogen General Permit Permit Optional Stormwater/Non-Point WWTF Limits Source Reduction Municipal Peirce Island Separate Pease WWTF WWTF NPDES Storm Sewer NPDES Permit Permit System Permit (MS4) Wastewater Stormwater Point and March 2, 2020 2 Non-Point Sources
Importance • New Regulatory Framework With Potential Advantages • Areas Of Concern – Growth Limiting Aspects – Potential Impacts on Private Property – Costs for Compliance Are Unknown But Significant • Action Tonight – Peer Review Request to Evaluate Basis Of Permit March 2, 2020 DRAFT Great Bay Total Nitrogen General Permit 3
Structure • Estuary Wide Load Target – Annual Load From All Sources • Wastewater Effluent Limits – Annual Load Instead of Growing Season Concentration • Water Quality Monitoring Program • Optional Stormwater and Non-Point Source (NPS) Nitrogen Reduction Pathway – 20+ Year Implementation March 2, 2020 DRAFT Great Bay Total Nitrogen General Permit 4
GBES Watershed 12 Regulated NH Comm. 30 Other NH Comm. Structure Watershed 10 ME Comm. Limits 52 Total ME WWTFs MS4 NPDES • Total Annual Nitrogen Load Target Not Included Limits (Approx) – 100 Kilograms/Hectare-Year NH WWTFs • From All Sources Of TN: in Permit – Wastewater Treatment Facilities NH Communities • End Of Pipe in Permit – Stormwater/NPS • Septic System (Human Waste) • Fertilizers • Atmospheric Deposition • Animal Waste March 2, 2020 DRAFT Great Bay Total Nitrogen General Permit 5
Structure • Annual Water Quality Testing Paid By Communities – City Responsible For ~30% Of Costs – No Ability To Adjust Scope And No End • Robust Program – Head Of Tide (River Inputs) – Continuous Data Sondes Estuary Wide – Benthic Organisms And Sediment Surveys – Eelgrass Mapping – Program Management And Reporting • Costs Estimated >$1M Annually – Portsmouth $300k To $500k annually March 2, 2020 DRAFT Great Bay Total Nitrogen General Permit 6
Compliance • Short Term (0 to ~ 10 Years) – Reduce Nitrogen Loads At Peirce Island WWTF • Cannot Achieve Stormwater/NPS Reduction Target Using BMPs – Need To Closely Track Land Use Change(s) To Keep Stormwater/NPS Nitrogen Discharge In Check – Upgrade Pease WWTF For Maximum Nitrogen Removal • Long Term (~10+ Years) – Continue To Optimize Nitrogen Removal At WWTFs – Likely Need to Address Stormwater/NPS Nitrogen Discharge • Structural And Non-Structural Stormwater/NPS Nitrogen Controls • Land Use Restrictions And/or Private Property Improvements March 2, 2020 DRAFT Great Bay Total Nitrogen General Permit 7
Costs • WWTF Capital and Operations – Peirce Island WWTF Nitrogen Removal – Pease WWTF Upgrade for Nitrogen Removal Planned Controlled – Effluent Water Quality Sampling for Nitrogen Costs • Land Use Tracking for Stormwater/NPS TN • Water Quality Monitoring – Current Costs Unknown and No End Unknown – Costs +/- Depending on Number of Communities Uncontrolled Costs • Stormwater/NPS Nitrogen Reduction Projects March 2, 2020 DRAFT Great Bay Total Nitrogen General Permit 8
Opportunities • Flexibility To Manage Nitrogen Removal At Both WWTFs (“bubble”) • Ability To Offset Stormwater/NPS Nitrogen Reduction Target Using WWTFs • Provides Structure for Credits For Non-WWTF Projects That Reduce Nitrogen – Requires Clarity In Permit March 2, 2020 DRAFT Great Bay Total Nitrogen General Permit 9
Risks • Significant Costs for Long Term Water Quality Monitoring Plan • Accepting Permit Structure and Scientific Basis “Locks In” Nitrogen Impairment – Will Result In Further Stormwater MS4 NPDES Permit Requirements • Technology May Not Be Adequate to Keep Stormwater/NPS Nitrogen Discharges In Check – Likely Result In Limits On Growth And Private Property Nitrogen Controls – Growth Shift From Communities With WWTFs To Communities Without • Future Reductions In TN Limits Likely – Reopener Clauses – Other Communities Are Not Included March 2, 2020 DRAFT Great Bay Total Nitrogen General Permit 10
Risks Not Regulated Storm/NPS From DES Model Regulated Storm/NPS 100 kilograms/hectare-year Not Regulated ME WWTFs Storm/NPS Regulated Storm/NPS NH WWTFs Measured New TN ME WWTFs Wastewater Effluent Limits NH WWTFs Baseline GBTN GP March 2, 2020 11
Next Steps • Decision On Peer Review Support – Concern That 100 kg/ha-yr Threshold Not Applicable – 9 Out of 12 Communities To Date Have Requested • Develop and Submit Comments on DRAFT Permit April 8, 2020 March 2, 2020 DRAFT Great Bay Total Nitrogen General Permit 12
Questions and Answers March 2, 2020 DRAFT Great Bay Total Nitrogen General Permit 13
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