Update on Stormwater RegulationLeague of Cities March 2011

Connie BosmaChief, Municipal BranchOffice of Wastewater ManagementU.S. Environmental Protection Agency

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402(p) of Clean Water Act• Section 402(p) established phased approach to permitting

certain stormwater discharges

• Section 402(p)(4) required EPA to establish permit application requirements for industrial and large municipal discharges (greater than 100,000 population)

• Section 402(p)(5) required EPA to conduct a study to identify other dischargers, assess their pollutant loadings and establish methods to control the pollutants and submit the results in a report to Congress

• Section 402(p)(6) provides authority for EPA to regulate other stormwater sources, as presented in the study, “to protect water quality”

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Phase I Stormwater Regulations

• Finalized in 1990

• Regulates stormwater discharges from:▫ 10 categories of industrial operations▫ Construction activity disturbing 5 acres or more is one

industrial category▫ Medium and large municipal separate storm sewer systems

(MS4s) in areas that serve 100,000 or more people

• Established:▫ Permit application requirements and deadlines▫ Requirements for a municipal stormwater management plan ▫ Permit exclusion for industrial activities that are not exposed

to stormwater

• 1,000 Phase I MS4s

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Phase II Stormwater Regulations• Finalized in 1999• Regulates stormwater discharges from:

▫ Small MS4s, defined as: An MS4 not already covered by an MS4 permit and Located in an “urbanized area” as defined by the Bureau of

Census, or Designated by the NPDES permitting authority on a case-by-case

basis if situated outside of urbanized areas.▫ Construction activities disturbing between one and five acres▫ Requires NPDES permits for these discharges

• Established six minimum control measures for small MS4 permits:1. Public Education & Outreach2. Public Participation/Involvement3. Illicit Discharge Detection & Elimination4. Construction Site Runoff Control5. Post-Construction Runoff Control6. Pollution Prevention/Good Housekeeping

• Basis for regulation: 1995 Report to Congress and 402(p)(6) authority

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Urbanized areas in the U.S.

• About 6,000 Phase II MS4s

• Urbanized areas cover 2% of total U.S. land area

Environmental Problem

• Stormwater contains pollutants including: nutrients, heavy metals, bacteria, sediments, trash, salinity, PAHs, temperature and pesticides Beach closures, prohibition or restrictions of

shellfish harvesting, wetland degradation• The velocity of stormwater discharges can cause

downstream flooding, infrastructure damage, stream bank erosion and habitat destruction

• Low levels of imperviousness directly impact biological condition in receiving waters. There is also loss in base flow in streams and groundwater recharge.

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Impacts of urbanization on stormwater runoff

Stormwater Impacts Will Worsen

• Nationwide, the amount of land area identified as urban increased nearly 6% between 1990 - 2000, (U.S. Census)

• Between 1970 – 2000, there was a 9.4% net increase in urban lands on the East Coast alone (USGS)

• Projected Growth Impervious surfaces covered 97,200 km2 of the conterminous

US in 2000. By 2030, impervious surface from housing development alone

will grow 36%.

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Program Challenges

• Significant development has occurred outside of regulated areas

• Since requirements vary across a state, there is no level playing field, providing an incentive to develop outside of regulated areas

• It is more cost-effective to incorporate proper stormwater control measures in the design of a site rather than retrofit controls at a later date

• Discharges within regulated areas not adequately controlled▫ Requirements too vague and unenforceable▫ Inconsistencies across the nation

Big Box

Planned Big Box

Big Box

Planned Big Box

Big Box

Big Box

Options for Performance Standards

• Discharges from New Development▫Mimic predevelopment hydrology▫Exceptions/alternative compliance options▫Credits▫State flexibility

• Discharges from Redevelopment▫Additional exceptions/alternative compliance

options▫State flexibility

• Exploring alternative compliance options for roads

Discharges from Individual Sites

•Benefits▫Protects water bodies from stormwater

dischargers▫Provides level playing field

•Assess options for regulating discharges from individual sites▫Size thresholds▫Location (discharges to the MS4; dischargers

directly to waters of the U.S.)•How to regulate (permit and/or direct rule)

Regulated MS4 ExpansionOptions

• No change – 2010 Urbanized Area defined by Census

• Extend coverage to jurisdiction boundaries of the MS4 rather than urbanized area boundary

• Extend coverage to urbanized clusters (Census)▫ Possible population cutoff

• Extend coverage to watershed boundaries (using

HUC defined watershed)▫ Possible population cutoff

Existing Discharge Management Plan (Retrofits)•Possible requirements imposed on some

MS4s▫Develop plan▫Implement plan over long period of time

•Options for Applicability▫Phase I MS4s▫Phase I and II MS4s▫MS4s that discharge to waters impaired by

stormwater

Chesapeake Bay

Potential specific provisions•Regulate additional MS4s•Apply performance standard to smaller

site sizes•Require retrofits of individual sites to

better address stormwater discharges•Restrict fertilizers

Shift in Paradigm

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Traditional approach – convey stormwater quickly from site to waterbody or detention pond

New approach – view stormwater as a resource manage on-site using green infrastructure

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Green Infrastructure

• Green Infrastructure refers to practices that use or mimic natural processes to infiltrate, evapotranspirate, or harvest stormwater near the site where it was generated.

• It differs from traditional approaches to stormwater management which focus primarily on flood control by piping stormwater to central outfalls and discharging to receiving streams or large detention basins

• Retaining stormwater discharge volumes on site reduces pollutant loads and stream erosion

• Green infrastructure has many other benefits▫ Recharge groundwater, provide greenspace, improve air

quality, reduce heat island effect▫ Cost-effective▫ Community liveability

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Green Infrastructure Approaches

Green roof

Rain garden

Open swaleParking lot infiltration island

Rain garden

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Green Infrastructure Approaches

Porous pavers, Philadelphia

Open swale, Portland, OR

Porous pavement sidewalk Large cistern,

Chicago

Terraced open swale

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Green Infrastructure Implementation• States are integrating green infrastructure principles into their

permits▫ Washington, DC - Massachusetts - New York▫ North Carolina - Montana - Maryland▫ New Jersey - Oregon - Wisconsin▫ Ohio - Connecticut - Kansas▫ West Virginia - Maine - Colorado▫ California - Vermont - Washington

• Communities are adopting green infrastructure approaches▫ Philadelphia, PA▫ Milwaukee, WI ▫ Chicago, IL ▫ Portland, OR ▫ Seattle, WA▫ Kansas City, MO ▫ Louisville, KY ▫ Richmond, VA

Schedule

•September 2011 – Proposal•November 2012 – Final Action