September 15, 2014 Winston Salem, VA Stormwater Capital Improvement Planning for Total Maximum Daily Load Compliance An Approach to Compliance with Stormwater MS4 Permits and TMDLs
Outline TMDL Requirements County Program Components BMP Evaluations and 15 year Capital Improvement Plan
Chesapeake Bay and Chesterfield County
Chesterfield County MS4
Stormwater Regulatory Requirements MS4 Permit Local Stormwater Requirements State Stormwater Regulations Stormwater Rule Chesapeake Bay and Local TMDLs Stormwater Funding Legislation
Municipal Drivers Infrastructure Needs MS4 Regulatory Requirements Partnerships Practical Solutions Aligned with local goals Watershed Needs Dedicated Funding Drainage & Flooding Needs
Stormwater and TMDL Requirements Drive Compliance Standard Requirements Stormwater MS4 Permit MS4 Program resources and method of funding MS4 Program Plan Stormwater CIP Plan MS4 Program implementation (13 specific activities) Monitoring (water quality, wet weather screening, floatables) Multiple reporting requirements Continue implementation of related ordinances TMDL Requirements Chesapeake Bay Special Condition included in the MS4 Permit: Specific pollutant load allocations and Pollutant of Concern reductions TMDL Action Plan Reporting Local TMDL Action Plans and reporting requirements
Chesapeake Bay TMDL Goals Reduction of nitrogen, phosphorus, and total suspended solids from stormwater Load allocation goals by state, basin and county level for each parameter Reduction requirements from both impervious (e.g. asphalt, roofs) and pervious (e.g. lawns) surfaces
Chesapeake Bay TMDL Goals
MS4 Permit TMDL Special Condition
Chesapeake Bay TMDL Requirements Pollutant reduction loads and targets included in the draft MS4 permit Submit Stormwater Capital Improvement Plan in first year Incremental reduction requirements (15 years) 1 st Permit Planning & 5% reduction 2 nd Permit 35% reduction 3 rd Permit 60% reduction
All TMDLs Require Action Plans Department of Environmental
Stormwater Program Components 1. Public Education & Participation 2. MS4 Maintenance Activities 3. Construction Site Runoff Control 4. Post-Construction Site Runoff Control 5. Illicit Discharge Detection & Elimination 6. Industrial & Commercial Facility Runoff Control 7. Water Quality, Watershed, & Stream Monitoring
Align Requirements and Program Activities Program Assessment & Benchmarking Organizational Analysis Cost Estimates: CIP O&M Watershed Evaluations MS4 TMDL Compliance Plan Permit Implementation
Development of CIP Tool Step 1 Stormwater General Permit Conditions Estimated Required Load Reductions Desktop Tool: 1. Calculate Loads (GIS/Permit) 2. Select (Unit) BMPs 3. Estimate Load Reduction 4. Determine Compliance (Repeat until Compliant) Step 2 Step 3 Planned BMPs Designed, Constructed, and Credited BMPs Unit BMP (Step 2) BMP Load Reduction
1. Calculate Loads Chesterfield County MS4 Permit Values
1. Calculate Loads: Land Use
Compliance 1 Calculate Challenges Loads: Nitrogen Chesterfield TMDL
1. Calculate Loads: Nitrogen
Compliance 1 Calculate Challenges Loads: Phosphorus Chesterfield TMDL
1. Calculate Loads: Phosphorus
Compliance 1 Calculate Challenges Loads: TSS Chesterfield TMDL
1. Calculate Loads: TSS
Chesterfield TMDL 1 Calculate Loads: Weighted Load
1 Calculate Loads: Required Reduction Required Pollutant Reduction [lbs/yr] Permit Cycle Total Total Total Nitrogen Phosphorus Suspended Sediment 1 5% 1,606 245 116,387 2 35% 11,240 1,712 814,707 3 60% 19,269 2,935 1,396,640 Total Reduction 32,115 4,892 2,327,734 (Pollutant reduction based on 2010 Census data)
1 Calculate Loads: Required Reduction Land [acres] Total Nitrogen [lbs/yr] Total Phosphorus [lbs/yr] Total Suspended Solids [lbs/yr]
2. Select BMPs
2. Unit BMPs
3. Estimate Load Compliance Existing BMPs + Proposed BMPs Unit BMPs
4. Determine Compliance Overall Compliance Path 100 140.0 120.0 80 100.0 % Achievement 60 40 80.0 60.0 $ Millions 40.0 20 20.0 0 2013 2018 2023 2028 0.0 Compliance Non Compliance N P S Overall Cost
4. Determine Compliance
Chesapeake Bay TMDL Cost $177 Million total cost over 15 years (Capital and Operating) Costs are not distributed evenly across permit cycles Establishing funding source now crucial
CIP Compliance Plan Drainage Projects Compliance Projects Stream Restoration Reservoir Restoration BMP Retrofits Outfall retrofits (HOA, public lands) Bioswales, green streets Non-structural BMPs
Identify BMP Retrofits and Costs
TMDL CIP Path Required Load Reduction Estimated based Size and Composition of MS4 Selected Unit BMPs Selected 12 BMP Types based on Acceptance, Cost, and Feasibility Unit Efficiency/Cost Alternative Compliance Scenarios Selected Primary, Secondary, and Tertiary BMPs used to Achieve Compliance
Summary Use of an Integrated Watershed Management approach can help meet multiple regulatory requirements in a cost-effective manner Align requirements with program activities to take credit for all stormwater related work Implementation of BMPs and retrofits is well understood, but tracking credits remains a challenge
Thank you! Tom Gallo ARCADIS 919-349-5700