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Implementing Post-Construction
Stormwater Controls
Greg Davis, EPA Region 8
Source: National Water Quality Inventory – 2000 Report (EPA)
Source: National Water Quality Inventory – 2000 Report (EPA)
Source: National Water Quality Inventory – 2000 Report (EPA)
Rain/snow is a source of pollution?Rain/snow is a source of pollution?
Storm water is a vector for pollutants
Storm water is a pollutant itself
Stormwater is a vectorStormwater is a vector
Common pollutants in storm water runoff include heavy metals, oil, grease, nutrients, toxic substances, sediment, bacteria, and temperature
Stormwater is a pollutant
Increased flow from impervious surfaces causes impacts to rivers and lakes
Increased imperviousness =
Increased runoff from storm events Increased exposure to pollutants Impacts to stream banks
Natural runoff Natural runoff conditionsconditions
Impervious conditionImpervious condition
Stream degradation with imperviousnessimperviousness
Watershed with lessthan 5% impervioussurface
Stream degradation with Stream degradation with imperviousnessimperviousness
10% impervious
- Stream width doubled - Bank erosion - Pool and riffle structure lost
Stream degradation with imperviousnessimperviousness
20% impervious
- Eroded stream banks - Intermittent flow - Noticeable debris
RUNOFF
TIME
Post-construction BMPs: landscape detention
Post-construction BMPs: Post-construction BMPs: retention pondretention pond
Post-construction BMPs: Post-construction BMPs: sand filter detention basinsand filter detention basin
Post-construction BMPs: Post-construction BMPs: grassy area with curb cutsgrassy area with curb cuts
Post-construction BMPs: Post-construction BMPs: level spreaderlevel spreader
Post-construction BMPs: Post-construction BMPs: porous concreteporous concrete
Post-construction BMPs: Post-construction BMPs: green roofgreen roof
Create an ordinance
Use/ borrow what other people have done
Demonstrate cost-effectiveness to legislators
Demonstrate environmental effects
http://www.epa.gov/owow/nps/ordinance/postcons.htm
Components of a stormwater ordinance
Provide training
Use/modify this presentation or any other non-copyrighted material
http://cfpub.epa.gov/npdes/outreach.cfm?program_id=0&otype=1
Provide training to legislators, contractors, contracting office technical representatives, developers, and facility maintenance staff
Utilize a stormwater fee
Stormwater fees should be based on effective impervious surface
Credits should be provided for retrofits and water quality features
Demonstrate financial impacts
The 9.8 million visitors to Montana represent 10 times Montana’s resident population and result in 43,300 jobs for an economic impact of $2.75 billion.
Source: Montana Fish, Wildlife, and Parks - Fish & Wildlife Recreation and Tourism
by: Cindy S. Swanson, Director, Watershed, Wildlife, Fisheries & Rare Plants, USDA Forest Service, Northern Region, Missoula (2004)
Use existing resources and speakers
Montana Fish, Wildlife, and Parks Research Reports - http://fwp.mt.gov/tmc/reports/default.html
Universe of Montana Institute for Tourism, Recreation, and Research - http://www.itrr.umt.edu/wilton.htm
Montana Trout Unlimited - http://www.montanatu.org/
Demonstrate financial impacts
In 17 Case studies EPA comparing conventional stormwater to green infrastructure practices, costs for green infrastructure were generally 15-80% cheaper
Reducing Costs through LID Strategies and Practices – http://www.epa.gov/nps/lid
Try calculating expenses yourself: Green Values Stormwater Toolbox -
http://greenvalues.cnt.org/
Demonstrate financial impacts
Evaluate public works contracts
Require post-construction controls in public works contracts
Public works areas can receive grant funding for green infrastructure
Ensure that contracts have a line item for budgeting post-construction BMP costs
Track BMP maintenance and specifications
Requires submission of final plans/ ownership/ and maintenance specs.
Use an NOT form or performance bond
Provide a 1-year warranty in bonds
Track BMP maintenance and specifications
Use existing systems and speak the same language as implementing staff
Georeference using GIS/ CAD system employed for storm sewer system mapping
Inspect using current inspector systems (e.g., Maximo)
Evaluate local land use planning
Imperviousness can be driven by:
Zoning Subdivision Codes Street and Road Standards Parking and Setback Requirements
Designate new MS4s
40 CFR 122.26(f)(4) Any person may petition the Director for the designation of a large, medium, or small municipal separate storm sewer system
Probable new MS4s include resort cities, high growth areas, and dischargers to pristine waters
Communicate, communicate,
communicate, communicate, communicate, communicate, communicate,…
Using other people’s terms (financial, engineering, environmental)
Contact: [email protected]
