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Central Massachusetts Regional Stormwater Coalition Part 4 Stormwater BMP Toolbox September 26, 2013 Community Innovation Challenge Grant 2013

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Central Massachusetts Regional Stormwater Coalition Objective of the Task Encourage small property owners and developers to use on-site treatment and management of stormwater. Format existing materials to be understood by the general public. Create Mini-Spec sheets for property owner to hand to developer or contractor. Encourage good construction and pollution prevention practices. Not reinvent the wheel

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Central Massachusetts Regional Stormwater Coalition Small-Site Stormwater Management Improve Water Quality a.Increase groundwater/aquifer recharge b.Improve surface water quality c.Reuse stormwater for watering d.Protect private property e.Reduce adverse impacts to stream channels f.Show the importance of BMP maintenance g.Reduce erosion and sedimentation during construction Hiwassee River Watershed Coalition, Inc.

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Central Massachusetts Regional Stormwater Coalition Site Characteristics 1.Identify Site Characteristics a.Building Locations b.Impervious and Pervious Areas c.Types of Impervious Area d.Slopes and Contours e.Wetlands or Drinking Water Sources

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Central Massachusetts Regional Stormwater Coalition Pervious and Impervious Area 1.Determine Pervious and Impervious Areas a.Design treatment and infiltration based on the surface area of all existing or proposed impervious area. 2.Minimize Impervious Area a.Pervious areas are more cost effective to maintain and construct.

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Central Massachusetts Regional Stormwater Coalition Soil Permeability Soil Permeability: ability of soil to allow water to pass through it. For Infiltration BMPs a.Soils with high permeability are desirable. b.Design requires calculating the correct area and volume of water to be stored and/or infiltrated to prevent BMP surcharging. c.Maintenance is important to maintain soil permeability and overall effectiveness.

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Central Massachusetts Regional Stormwater Coalition Total Suspended Solids (TSS) Removal Rates 1.BMPs minimize volume of TSS entering surface waters and/or aquifers 2.MassDEP Stormwater Handbook is not required for single family homes or small development, but guides effective BMP design. 1.Requires 80% TSS removal. 2.Requires 44% TSS removal prior to infiltration, if BMP is located within a critical area.

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Central Massachusetts Regional Stormwater Coalition Site Limitations and Setbacks Massachusetts Stormwater Handbook Natural site limitations include: steep slopes, wetlands, surface waters, and seasonal high groundwater.

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Central Massachusetts Regional Stormwater Coalition Minimize BMP Space Requirements 1.Minimize stormwater runoff by maximizing onsite treatment, storage, and infiltration. 2.Retain stormwater at small sites with the following design principles: a.Reduce building footprints; b.Cluster buildings; c.Slope impervious surfaces toward stormwater BMPs; d.Install vegetated filter strips or rain gardens at the end of driveways and parking lots; e.Utilize rain barrels or cisterns.

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Central Massachusetts Regional Stormwater Coalition Mini-Specs

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Central Massachusetts Regional Stormwater Coalition For Each BMP Description Benefits Applicability Limitations Level of Treatment Provided Costs Common Applications Maintenance Schedule Resources

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Central Massachusetts Regional Stormwater Coalition BMPs Included in the Toolbox Pretreatment BMPs 1.Street Sweeping 2.Deep Sump Catch Basins Treatment BMPs 1.Bioretention Areas (Rain gardens) 2.Subsurface infiltration systems (Cultech, Stormtech) 3.Tree box filters Lance Landscape

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Central Massachusetts Regional Stormwater Coalition BMPs Included in the Toolbox (cont) Infiltration BMPs 1.Porous pavement 2.Dry wells 3.Infiltration Trenches Conveyance BMPs 1.Drainage Channels 2.Water quality swales/grassed channels

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Central Massachusetts Regional Stormwater Coalition BMP Accessories 1.Level Spreaders 2.Catch Basin Inserts 3.Rip rap 4.Rain barrels 5.Cisterns 6.Erosion control measures Mulching Hay bales Silt fencing Biodegradable mesh Photo: University of Southern Alabama Photo: BMP Supplies

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Central Massachusetts Regional Stormwater Coalition Erosion Prevention BMPs: Mulching Increase stormwater infiltration, reduce runoff velocity, and provide more suitable habitat for seedling germination. MaterialApprox. CostRemarks Wood Chips $22/Cu. Yd. Resistant to wind blowing. Decomposes slowly. Can absorb nutrients from soil. Bark Mulch $35/Cu. Yd. Resistant to wind blowing. Decomposes slowly. Compost$20/Cu. Yd. Most prone to erosion out of natural stabilization materials. Not recommended for steep slopes. Excellent moisture conserver. Resistant to wind blowing. Hay/Straw$4/bale Use straw where mulch is maintained for more than three months. Subject to wind blowing unless anchored. Best material for germinating seeds. Peat Moss $50/Cu. Yd. Subject to wind blowing unless kept wet.

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Central Massachusetts Regional Stormwater Coalition Construction Management Practices Construction activities can contribute sediment to surface water bodies, provide the opportunity for spills from equipment to occur and for nuisance dust to be generated. Best management practices can reduce the potential for these issues to occur. NPDES Construction General Permit vs. Local Construction Requirements

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Central Massachusetts Regional Stormwater Coalition Construction Management Practices Small Site SWPPP Preventing sediment transport is the primary goal of a SWPPP. Development: * Owner, Designer Contractor Considerations: * Existing Site Conditions * Limit and Stabilize Site Disturbances * Keep Runoff Velocities Low * Protect Disturbed Areas * Retain Sediment Onsite * Include an Operation, Inspection and Maintenance Plan. Complete a site walk with all parties prior to construction. GatorGuard Environmental Products

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Central Massachusetts Regional Stormwater Coalition Site Staging 1.Minimize Disturbance 2.Avoid Steep Slopes and Excessive Grading 3.Stockpile Stabilization 4.Using Vegetation for Stabilization 5.Dust Prevention

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Central Massachusetts Regional Stormwater Coalition Equipment and Waste Management 1.Cleaning Vehicles Leaving the Site 2.Fueling Operations 3.Construction Waste Management Photo: Hong Kong EPD

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Central Massachusetts Regional Stormwater Coalition Roles of Professionals in a Residential Project

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Central Massachusetts Regional Stormwater Coalition Integrating LID into Site Design