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: davis.gregory@epa.gov