Proposed Stormwater Management Regulations: 314 CMR 21.00
Proposed Stormwater Management Regulations: 314 CMR 21.00 Stormwater General Permit Requirements Engineering Perspective Craig C. Lizotte, P.E. Manager of Land Development [email protected]
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Stormwater General Permit What and When Intended to help improve water quality by treating and infiltrating stormwater Target sites with •
•
> 5 Acres Regulated Impervious Area (RIA) State Wide
Source: Riverways Website
> 2 Acres RIA in TMDL Areas
Details for compliance to be in: RIA General Stormwater Permit Workbook Out for public comment, summer 2009 Promulgation late 2009 early 2010
Source: Charles River Watershed Website
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Stormwater General Permit Requirements All existing sites: baseline performance standards • No retrofits required for non TMDL sites
New development of RIA • Install LID techniques and stormwater BMPs to meet Standards 3-6 of MA Stormwater Management Standards
Redevelopment of RIA • Install LID BMPs that maintain existing peak rate, recharge and treatment • Include infiltration of at least 40% of the “redevelopment volume”
TMDL areas: stormwater discharges from RIA • Infiltration BMPs for pollutant reduction required by TMDL
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Baseline Performance Standards: All Sites All sites: baseline performance standards (Threshold: 5 acres or 2 acres impervious inTMDL area) • Stormwater Management Plan & Team • Operation and Maintenance Plan • Snow & deicing practices management plan • Pavement sweeping 2X per year
Self Certification – forms and fees -180 days
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Stormwater General Permit Requirements Redevelopment of > 5 acres Redevelopment of RIA • Redevelopment includes some level roof and pavement repair • Install LID BMPs that maintain or enhance existing: • Peak discharge rate, recharge volume, water quality treatment
• Include infiltration of at least 40% of the redevelopment volume • Redevelopment volume = recharge volume or the WQV (whichever is greater) • Details/clarification on implementation and calculation needed
• If infiltration not possible, enhanced treatment or reduction of impervious area required • Off-site mitigation allowed • Variance if cant comply Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Stormwater General Permit Requirements New Development >5 acres New development of RIAs > 5 acres • Development definition is for pavement and/or roof • Install LID techniques and stormwater BMPs that can meet Standards 3-6 of the Massachusetts Stormwater Management Standards • Standard 3: Recharge. Post development recharge to approximate existing recharge (issue: permeable pavement considered impermeable) • Standard 4: TSS Removal. Post development annual removal of 80% TSS loads • Standard 5: Land Uses with Higher Potential Pollutant Loads (LUHPPLs) • Standard 6: Water Quality Discharge to Critical Areas, ORWS, Drinking Water Supplies, Etc.
• Requirements generally same as WPA stormwater management standards, but... • Will include some upland sites not under WPA • Site development is not the trigger but it is the size of roof and/or pavement being developed • Off-site mitigation not allowed Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
TMDL Areas: Additional Requirements Existing Sites Existing sites: TMDL areas Stormwater discharge from RIA > 2 acres • Retrofits for infiltration BMPs for pollutant reduction required by TMDL • Pollutant reduction based on TMDL (65% phosphorous in Charles River) • 4.5 years for retrofit design • 10 years for construction completion • Off-site mitigation allowed
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
TMDL Areas: Additional Performance Standards for Redevelopment/Development Sites Redevelopment/Development of RIAs in TMDL areas > 2 acres In addition to the 65% phosphorous reduction these sites must meet the performance standards for >5 acres sites previously identified.
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
Ssource: Stormwater BMP Manual EPA/Tetratech
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Pollutant Reduction Calculators Use EPA's "BMP Performance Curve" model to estimate pollution reduction from BMPs 8 BMPs identified: infiltration basin, infiltration trench, gravel wetland, porous pavement, wet pond, dry pond, bioretention, grass swale Removal based on soil type, land use, BMP type and runoff volume directed to BMP BMPs must be designed in accordance with the Stormwater Management Handbook Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
What Does This Mean to You? Regulations still in draft form Non-TMDL areas: more formalized requirements for O&M, new annual compliance efforts New development or redevelopment (Non TMDL): Increased applicability of stormwater management standards. TMDL Areas: retrofits required, must comply with TMDL treatment requirements.
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Existing Conditions
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Stormwater Retrofit, Suitable Soils
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Stormwater Retrofit, Unsuitable Soils
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Stormwater General Permit What and When Intended to help improve water quality by treating and infiltrating stormwater Target sites with •
•
> 5 Acres Regulated Impervious Area (RIA) State Wide
Source: Riverways Website
> 2 Acres RIA in TMDL Areas
Details for compliance to be in: RIA General Stormwater Permit Workbook Out for public comment, summer 2009 Promulgation late 2009 early 2010
Source: Charles River Watershed Website
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Stormwater General Permit Requirements All existing sites: baseline performance standards • No retrofits required for non TMDL sites
New development of RIA • Install LID techniques and stormwater BMPs to meet Standards 3-6 of MA Stormwater Management Standards
Redevelopment of RIA • Install LID BMPs that maintain existing peak rate, recharge and treatment • Include infiltration of at least 40% of the “redevelopment volume”
TMDL areas: stormwater discharges from RIA • Infiltration BMPs for pollutant reduction required by TMDL
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Baseline Performance Standards: All Sites All sites: baseline performance standards (Threshold: 5 acres or 2 acres impervious inTMDL area) • Stormwater Management Plan & Team • Operation and Maintenance Plan • Snow & deicing practices management plan • Pavement sweeping 2X per year
Self Certification – forms and fees -180 days
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Stormwater General Permit Requirements Redevelopment of > 5 acres Redevelopment of RIA • Redevelopment includes some level roof and pavement repair • Install LID BMPs that maintain or enhance existing: • Peak discharge rate, recharge volume, water quality treatment
• Include infiltration of at least 40% of the redevelopment volume • Redevelopment volume = recharge volume or the WQV (whichever is greater) • Details/clarification on implementation and calculation needed
• If infiltration not possible, enhanced treatment or reduction of impervious area required • Off-site mitigation allowed • Variance if cant comply Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Stormwater General Permit Requirements New Development >5 acres New development of RIAs > 5 acres • Development definition is for pavement and/or roof • Install LID techniques and stormwater BMPs that can meet Standards 3-6 of the Massachusetts Stormwater Management Standards • Standard 3: Recharge. Post development recharge to approximate existing recharge (issue: permeable pavement considered impermeable) • Standard 4: TSS Removal. Post development annual removal of 80% TSS loads • Standard 5: Land Uses with Higher Potential Pollutant Loads (LUHPPLs) • Standard 6: Water Quality Discharge to Critical Areas, ORWS, Drinking Water Supplies, Etc.
• Requirements generally same as WPA stormwater management standards, but... • Will include some upland sites not under WPA • Site development is not the trigger but it is the size of roof and/or pavement being developed • Off-site mitigation not allowed Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
TMDL Areas: Additional Requirements Existing Sites Existing sites: TMDL areas Stormwater discharge from RIA > 2 acres • Retrofits for infiltration BMPs for pollutant reduction required by TMDL • Pollutant reduction based on TMDL (65% phosphorous in Charles River) • 4.5 years for retrofit design • 10 years for construction completion • Off-site mitigation allowed
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
TMDL Areas: Additional Performance Standards for Redevelopment/Development Sites Redevelopment/Development of RIAs in TMDL areas > 2 acres In addition to the 65% phosphorous reduction these sites must meet the performance standards for >5 acres sites previously identified.
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
Ssource: Stormwater BMP Manual EPA/Tetratech
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Pollutant Reduction Calculators Use EPA's "BMP Performance Curve" model to estimate pollution reduction from BMPs 8 BMPs identified: infiltration basin, infiltration trench, gravel wetland, porous pavement, wet pond, dry pond, bioretention, grass swale Removal based on soil type, land use, BMP type and runoff volume directed to BMP BMPs must be designed in accordance with the Stormwater Management Handbook Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
What Does This Mean to You? Regulations still in draft form Non-TMDL areas: more formalized requirements for O&M, new annual compliance efforts New development or redevelopment (Non TMDL): Increased applicability of stormwater management standards. TMDL Areas: retrofits required, must comply with TMDL treatment requirements.
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Existing Conditions
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Stormwater Retrofit, Suitable Soils
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
TRANSPORTATION . LAND DEVELOPMENT . ENVIRONMENTAL SERVICES
Stormwater Retrofit, Unsuitable Soils
Copyright 2009, VHB/Vanasse Hangen Brustlin, Inc.
