EPA’s Stormwater Rulemaking: How Potential Changes in the NPDES Stormwater Regulations Could Impact the Design of Stormwater Controls Rachel Herbert USEPA/OW/OWM/WPD for AASHTO Subcommittee on Design Meeting

Purpose of Today’s Discussion Construction & Development Effluent Limitation Guidelines New Stormwater Regulations

Overview of Construction & Development Effluent Limitation Guideline (C&D ELG) General Overview of Requirements Erosion & Sedimentation Requirements Sampling Requirements Other Requirements

General C&D ELG Requirements EPA promulgated new regulations for construction and development (C&D) sites on December 1, New rule requires all construction sites subject to permits to implement erosion and sediment controls and pollution prevention measures Phase-in requirement for sites to sample stormwater discharges and comply with a numeric effluent limitation (NEL) of 280 nephelometric turbidity units (NTU). Beginning August 1, 2011 sites disturbing 20+ acres at once Beginning February 2, 2014 sites disturbing 10 acres at once Requirements must be incorporated into state permits (general or individual) whenever permits are re-issued EPA intends to issue a new CGP in June 2011

Erosion and Sedimentation Requirements Control stormwater volume and velocity within the site to minimize soil erosion; Control stormwater discharges to minimize erosion at outlets and downstream channel and streambank erosion; Minimize the amount of soil exposed during construction activity; Minimize the disturbance of steep slopes; Design, install and maintain erosion and sediment controls considering factors such as precipitation and soil characteristics; Provide and maintain natural buffers around surface waters, direct stormwater to vegetated areas to increase sediment removal and maximize stormwater infiltration, unless infeasible; and Minimize soil compaction and, unless infeasible, preserve topsoil.

Sampling Requirements 280 NTU Limitation does not apply on days with precipitation exceeds the local 2-year, 24-hour storm event Monitoring frequency is up to the permitting authority, but EPA recommends at least 3 grab samples per day at each discharge point EPA has not specified any analytical methods, but envisions that use of a properly calibrated field turbidity meter is adequate For linear projects, permitting authority can consider representative sampling instead of sampling at each discharge point Even if permitting authority allows representative sampling, all discharge points are still subject to compliance with effluent limitation Permitting authority will specify data reporting requirements

Other Requirements Soil Stabilization & Dewatering Requirements Initiate stabilization of disturbed areas immediately whenever any clearing, grading, excavating or other earth disturbing activities have permanently ceased, when earth disturbing activities have temporarily ceased and will not resume for a period exceeding 14 calendar days. Where vegetative stabilization is infeasible, alternative stabilization measures must be employed. Pollution Prevention Requirements Prohibited Discharges

Overview of New Rulemaking Background on the Federal Stormwater Program Stormwater Challenges The National Research Council (NRC) Report EPA has initiated a rulemaking to improve its stormwater program. Stormwater Rulemaking Schedule Preliminary Considerations for Rulemaking

Federal Stormwater Regulations Phase IPhase II Year Finalized Regulated Entities Medium & large MS4sSmall MS4s in an “urbanized area” (UA) 10 categories of industrial operations Additional designated MS4s outside of UAs Active construction sites of 5 acres or more Active construction sites disturbing between 1 and 5 acres

Federal Stormwater Regulations (cont’d) Phase IPhase II MS4 Stormwater Management Program (SWMP) Requirements MS4 must develop and implement a SWMP to: find and eliminate illicit discharges control discharges from its system by addressing discharges from active construction sites, new development and redevelopment, and industrial activities MS4 must develop and implement a SWMP that includes 6 minimum measures: Public education & outreach Public participation/ involvement Illicit discharge detection & elimination Construction site runoff control Post-Construction site runoff control Pollution prevention/ good housekeeping

Federal Stormwater Regulations (cont’d) Phase IPhase II Stormwater Pollution Prevention Plan (SWPPP) Requirements Construction & industrial stormwater dischargers must develop and implement a SWPPP N/A

Stormwater Challenges Urban stormwater is the primary source of water quality impairment:  13% of all rivers and streams  18% of all lakes  32% of all estuaries Much progress has been made; however, significant challenges remain to protect waterbodies from impact of stormwater discharges

The National Research Council (NRC) Report In 2006 EPA commissioned the National Research Council (NRC) to study EPA’s stormwater program In October 2008 NRC released Urban Stormwater Management in the United States, available at: Key Findings Current approach is unlikely to produce an accurate picture of the problem and unlikely to adequately control stormwater’s contribution to waterbody impairment Requirements leave a great deal of discretion to dischargers to set their own standards and ensure compliance, which results in inconsistency across the nation Poor accountability and uncertain effectiveness

Key Recommendations in the NRC Report “A straightforward way to regulate stormwater contributions to waterbody impairment would be to use flow or a surrogate, like impervious cover, as a measure of stormwater loading ….” “Efforts to reduce stormwater flow will automatically achieve reductions in pollutant loading. Moreover, flow is itself responsible for additional erosion and sedimentation that adversely impacts surface water quality.” “Stormwater control measures that harvest, infiltrate, and evapotranspirate stormwater are critical to reducing the volume and pollutant loading of small storms.” US Department of Transportation Headquarters Washington, DC Turkeyville, MI Rest Area 722

Stormwater Rulemaking Schedule Primary impetus: to protect waterbodies from the stormwater impact of urbanization Completed Activities: October 30, 2009: Federal Register (FR) Notice announcing EPA’s intent to distribute questionnaires (Information Collection Request (ICR) seeking data to inform the rulemaking from three groups: Owners, operators, developers, and contractors of developed sites Owners of Municipal Separate Storm Sewer Systems (MS4s) States and territories January – March 2010: Listening Sessions input on preliminary rulemaking considerations (FR Notice published Dec. 28, 2009) May 2010: EPA published a final FR ICR Notice

Stormwater Rulemaking Schedule (Cont’d) Upcoming Activities: Summer 2010: EPA expects to distribute the questionnaires Late 2011: EPA expects to propose a rule to be published in the FR for public comment Late 2012: EPA expects to take final action

Preliminary Considerations for Rulemaking 1. Expand the universe of regulated discharges beyond urbanized area 2. Establish substantive post-construction requirements for new and redevelopment 3. Develop a single set of consistent requirements for all MS4s, in place of existing “Phase I” and “Phase II” rules 4. Address stormwater discharges from existing development through retrofitting 5. Consider additional requirements to further reduce stormwater impacts in the Chesapeake Bay NOTE: No decisions have been made on any of the items discussed from this slide forward.

1. Expand the universe of regulated discharges beyond urbanized area: Depiction of Current MS4 Roadway Regulation Area B (not a regulated MS4) Area C (regulated MS4) Area A (regulated MS4) Regulated MS4 area Key NOTE: Disturbances of ≥ 1 acre are required to comply with NPDES construction requirements, even If outside the urbanized area.

1. Expand the universe of regulated discharges beyond urbanized area What is the best way to expand the universe of regulated discharges beyond Urbanized Area? Is there an appropriate boundary for permit coverage if not based on the current definition of Urbanized Area? What criteria could be used to identify areas? Should States decide the areas to include?

2. Establish substantive post-construction requirements for new and redevelopment Develop a standard that promotes sustainable practices that mimic natural processes to infiltrate and recharge, evapotranspire, and/or harvest and reuse precipitation. Should there be a national requirement for on-site stormwater controls such that post development hydrology must mimic pre-development hydrology on a site-specific basis? Options for meeting the requirement could be: on-site retention of specific sized storm, limits on amount of effective impervious area, use of site-specific calculators to determine predevelopment hydrology, and/or use of regional standards to reflect local circumstances. Options if standard could not be met: off-site mitigation, payment in lieu, others? Should the standards be different for new development vs. redevelopment?

3. Develop a single set of consistent requirements for all regulated MS4s Many Phase I & II MS4s address issues that are similar, but the regulatory requirements are different. Should DOTs have different requirements than traditional MS4s? What requirements should EPA apply to DOTs? Should EPA apply all of the 6 minimum measures to DOTs? Are there other measures that would achieve better water quality, like more emphasis on source control? Phase I MS4s are required to implement a program to control discharges from industrial facilities. Should this requirement be extended to all MS4s?

4. Addressing stormwater discharges from existing development Stormwater discharges from developed areas are significant contributors to water quality impairments; some MS4 permits require retrofit practices that infiltrate or retain stormwater. Should EPA consider retrofit requirements, such as: Development of a retrofit plan? Implementation of a retrofit plan? Should any requirements apply only to large MS4s? Should any requirements apply only to water quality impaired waters?

5. Consider additional requirements to further reduce stormwater impacts in the Chesapeake Bay What additional requirements should EPA consider to protect the Chesapeake Bay? Buffer requirements? Additional requirements on active construction? Further extending area of coverage? Should these provisions be applied to other sensitive areas?

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