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Part 4

Stormwater BMP Toolbox

September 26, 2013Community Innovation Challenge Grant2013Central Massachusetts Regional Stormwater CoalitionObjective of the TaskEncourage 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 wheelCentral Massachusetts Regional Stormwater CoalitionOriginally intended to be most useful to the communities that were least compliant and that may not even have understood that these tasks were required. 2Small-Site Stormwater ManagementImprove Water Quality Increase groundwater/aquifer rechargeImprove surface water qualityReuse stormwater for wateringProtect private propertyReduce adverse impacts to stream channelsShow the importance of BMP maintenanceReduce erosion and sedimentation during construction

Hiwassee River Watershed Coalition, Inc. Central Massachusetts Regional Stormwater CoalitionReduce pollutant discharges to surface water bodiesProvide green areas to pool and infiltrate Provide aesthetic value Provide opportunity for stormwater reuse

3Site Characteristics Identify Site CharacteristicsBuilding LocationsImpervious and Pervious AreasTypes of Impervious AreaSlopes and ContoursWetlands or Drinking Water Sources Central Massachusetts Regional Stormwater CoalitionUtilize, dont fight, natural features. Minimize impervious in the first place. 4Pervious and Impervious Area Determine Pervious and Impervious AreasDesign treatment and infiltration based on the surface area of all existing or proposed impervious area.Minimize Impervious Area Pervious areas are more cost effective to maintain and construct. Central Massachusetts Regional Stormwater CoalitionSoil Permeability Soil Permeability: ability of soil to allow water to pass through it. For Infiltration BMPsSoils with high permeability are desirable. Design requires calculating the correct area and volume of water to be stored and/or infiltrated to prevent BMP surcharging. Maintenance is important to maintain soil permeability and overall effectiveness.

Central Massachusetts Regional Stormwater CoalitionUSDA NRCS Web Soil Survey and Field survey methods are described

6Total Suspended Solids (TSS) Removal RatesBMPs minimize volume of TSS entering surface waters and/or aquifersMassDEP Stormwater Handbook is not required for single family homes or small development, but guides effective BMP design. Requires 80% TSS removal.Requires 44% TSS removal prior to infiltration, if BMP is located within a critical area.

Central Massachusetts Regional Stormwater CoalitionSite Limitations and Setbacks

Massachusetts Stormwater HandbookNatural site limitations include: steep slopes, wetlands, surface waters, and seasonal high groundwater.Central Massachusetts Regional Stormwater CoalitionMinimize BMP Space Requirements Minimize stormwater runoff by maximizing onsite treatment, storage, and infiltration. Retain stormwater at small sites with the following design principles:Reduce building footprints;Cluster buildings;Slope impervious surfaces toward stormwater BMPs;Install vegetated filter strips or rain gardens at the end of driveways and parking lots;Utilize rain barrels or cisterns. Central Massachusetts Regional Stormwater Coalition

Mini-SpecsCentral Massachusetts Regional Stormwater CoalitionFor Each BMPDescriptionBenefitsApplicabilityLimitationsLevel of Treatment ProvidedCostsCommon ApplicationsMaintenance ScheduleResources

Central Massachusetts Regional Stormwater CoalitionBMPs Included in the ToolboxPretreatment BMPsStreet SweepingDeep Sump Catch BasinsTreatment BMPsBioretention Areas (Rain gardens)Subsurface infiltration systems (Cultech, Stormtech)Tree box filters

Lance LandscapeCentral Massachusetts Regional Stormwater CoalitionBMPs Included in the Toolbox (cont)Infiltration BMPsPorous pavementDry wellsInfiltration TrenchesConveyance BMPsDrainage ChannelsWater quality swales/grassed channels

Central Massachusetts Regional Stormwater CoalitionBMP AccessoriesLevel SpreadersCatch Basin InsertsRip rapRain barrelsCisternsErosion control measuresMulchingHay balesSilt fencingBiodegradable mesh

Photo: University of Southern AlabamaPhoto: BMP Supplies

Central Massachusetts Regional Stormwater CoalitionErosion Prevention BMPs: MulchingIncrease stormwater infiltration, reduce runoff velocity, and provide more suitable habitat for seedling germination.

MaterialApprox. CostRemarksWood 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/baleUse 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.Central Massachusetts Regional Stormwater CoalitionConstruction 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 Central Massachusetts Regional Stormwater CoalitionConstruction Management Practices Small Site SWPPP Preventing sediment transport is the primary goal of a SWPPP. Development: * Owner, Designer ContractorConsiderations: * 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 ProductsCentral Massachusetts Regional Stormwater CoalitionSite StagingMinimize Disturbance Avoid Steep Slopes and Excessive GradingStockpile Stabilization Using Vegetation for Stabilization Dust Prevention Central Massachusetts Regional Stormwater CoalitionEquipment and Waste ManagementCleaning Vehicles Leaving the SiteFueling OperationsConstruction Waste Management

Photo: Hong Kong EPDCentral Massachusetts Regional Stormwater Coalition

Roles of Professionals in a Residential ProjectCentral Massachusetts Regional Stormwater CoalitionIntegrating LID into Site Design

Central Massachusetts Regional Stormwater Coalition