Implementing Post-Construction Stormwater Controls Greg Davis, EPA Region 8

Source: National Water Quality Inventory – 2000 Report (EPA)

Rain/snow is a source of pollution? Storm water is a vector for pollutants Storm water is a pollutant itself

Stormwater 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 conditions

Impervious condition

imperviousness Stream degradation with imperviousness Watershed with less than 5% impervious surface

Stream degradation with imperviousness 10% impervious - Stream width doubled - Bank erosion - Pool and riffle structure lost

imperviousness Stream degradation with imperviousness 20% impervious - Eroded stream banks - Intermittent flow - Noticeable debris

RUNOFF TIME

Post-construction BMPs: landscape detention

Post-construction BMPs: retention pond

Post-construction BMPs: sand filter detention basin

Post-construction BMPs: grassy area with curb cuts

Post-construction BMPs: level spreader

Post-construction BMPs: porous concrete

Post-construction BMPs: green roof

Create an ordinance Use/ borrow what other people have done Demonstrate cost-effectiveness to legislators Demonstrate environmental effects

Components of a stormwater ordinance

Provide training Use/modify this presentation or any other non-copyrighted material 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 Universe of Montana Institute for Tourism, Recreation, and Research - Montana Trout Unlimited - 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 – Try calculating expenses yourself: Green Values Stormwater Toolbox - 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 (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)

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