NRC\’s Urban Stormwater Management in the United States: Implications for MS4 Permi Holders

11th Annual EPA Region 6 MS4 Operators’ Conference, Houston, TXJune 25, 2009The National Research Council’sUrban Stormwater Management in the United States:Implications for MS4 Permit HoldersPresented byMICHAEL F. BLOOM, P.E., CFMSenior AssociateTOPICS• National Research Council• Why was the Report prepared?• Who prepared the Report?• What does the Report say?• What do others think about it?• What is EPA doing in response?• What impacts are likely?• What should I do now?1NATIONAL RESEARCH COUNCIL• National Academy of Sciences created in 1863• Private, nonprofit, society of scholars• Dedicated to further use of science and technology for general welfare• NRC organized in 1916• NRC furthers knowledge and advises the federal government• Governed jointly by Institute of Medicine and NAS• See www.national-academies.orgWHY WAS REPORT PREPARED?[EPA Requested It]• Clarify the mechanisms by which pollutants in stormwater discharges affect ambient water quality criteria and define the elements of a “protocol” to link pollutants in stormwater discharges to ambient water quality criteria. • Consider how useful monitoring is for both determining the potential of a discharge to contribute to a water quality standards violation and for determining the adequacy of stormwater pollution prevention plans. What specific parameters should be monitored and when and where? What effluent limits and benchmarks are needed to ensure that the discharge does not cause or contribute to a water quality standards violation? • Assess and evaluate the relationship between different levels of stormwater pollution prevention plan implementation and in-stream water quality, considering a broad suite of stormwater control measures (SCMs). 2WHY WAS REPORT PREPARED?[EPA Requested It]• Make recommendations for how to best stipulate provisions instormwater permits to ensure that discharges will not cause or contribute to exceedances of water quality standards. This should be done in the context of general permits. As a part of this task, the committee will consider currently available information on permit and program compliance. • Assess the design of the stormwater permitting programimplemented under the Clean Water Act.AUTHORS3OVERSIGHT BOARDINPUT RECEIVED FROMSTAKEHOLDERS & REVIEWERS•City of Austin•Heal the Bay•King County, WA•California Stormwater Quality •City of SeattleAssociation•Irvine Ranch Water District•Southern California Coastal •City of PhiladelphiaWater Research Project•Vermont Department of •Southern California Monitoring Environmental ConservationCoalition•University of Texas•Natural Resources Defense •UNC Institute of Marine CouncilSciences•Geosyntec•UCLA•Clean Water Services, OR•University of Washington•Florida Gulf Coast University•California Water Board•University of Florida•City of Los Angeles•University of Georgia•Michigan State University•Minnesota Pollution Control •CH2M HillAgency•University of Maryland4REPORT TABLE OF CONTENTSREPORT TABLE OF CONTENTS5REPORT TABLE OF CONTENTSREPORT HIGHLIGHTS: Challenges• Regulatory history• Administrative and financial burdens6REPORT HIGHLIGHTS: Stormwater Impacts• Urbanization is bad for aquatic lifeREPORT HIGHLIGHTS: Literature Review• Excellent references• Important conclusions reported and summarized• Includes information about:– Hydrology– MS4 representative monitoring– Atmospheric deposition– Building materials as a source– Urbanization impacts– Land use changes– Geomorphology– Biological responses to urbanization7REPORT HIGHLIGHTS: Stormwater Impacts• Urbanization leads to habitat loss8REPORT HIGHLIGHTS: Monitoring Stormwater• MS4 runoff well characterized (see Pitt’s National Stormwater Quality Database)• Industrial monitoring should be risk-based and improved• Use continuous, flow-weighted sampling rather than grab sampling• Obtain flow and rainfall data• Use biological monitoring• Obtain statistically valid number of samplesREPORT HIGHLIGHTS: Management Approaches• BMPs renamed:Stormwater Control Measures (SCMs)• Summary of SCMs– Impervious cover reductions– Rainwater harvesting– Swales– Silt fences– Bio-infiltration9REPORT HIGHLIGHTS: Management Approaches• Use watershed-based permitting for all sources (wastewater and stormwater)• Issue integrated permits by watershed• Create lead permittee in each watershed (delegation)• Use residual designation authority to bring more urbanized areas into the permitting program• Establish biological end points for management• Improve monitoring for Phase I MS4s• Add monitoring for Phase II MS4sREPORT HIGHLIGHTS: Management Approaches• Establish numeric municipal action levels(MEP as a number)• Regulate product sale and usage • Use effluent limits (loads or concentrations)• Impose imperviousness limits• Impose turbidity limit for construction sites• Issue guidance on identifying high-risk industrialfacilities• Provide more resources and funding• Expand use of TMDLs (non-impaired waters)• Regulate flow10