Improving the EPA Multi-Sector General Permit for Industrial Stormwater Discharges

Industrial stormwater is derived from precipitation and/or runoff that comes in contact with industrial manufacturing, processing, storage, or material overburden and then runs offsite and enters drainage systems or receiving waters. In 1987, Congress significantly expanded the National Pollutant Discharge Elimination System (NPDES) program through amendments to the Clean Water Act to include industrial stormwater runoff conveyed through outfalls directly to receiving waters or indirectly through municipal separate storm sewer systems. The added regulation of stormwater in the NPDES program has been challenging. Stormwater is produced throughout a developed landscape, and its production and delivery are episodic. In 2009, the National Research Council released a comprehensive report on the Environmental Protection Agency's Stormwater Program that covered all sectors of the program. This study builds on that report, with a focus on industrial stormwater monitoring and management. Table of ContentsFront MatterSummary1 Introduction2 Pollutant Monitoring Requirements and Benchmark Thresholds3 Stormwater Sampling and Data Collection4 Consideration of Retention Standards in the Multi-Sector General PermitReferencesAppendixesAppendix A: State Industrial Stormwater Permit Benchmark Monitoring ComparisonAppendix B: Lists of Pollutants from Which Industries Self-Identified the Need for Monitoring in the 1992 Group Applications, Adapted from EPA Form 2F, 1992Appendix C: Monitoring Parameters Required in Environmental Protection Agency 2015 Multi-Sector General PermitAppendix D: 2015 Multi-Sector General Permit (MSGP) Data AnalysisAppendix E: Additional Data on Technical Achievability of Treatment Stormwater Control MeasuresAppendix F: Biographical Sketches of Committee Members and StaffAppendix G: Disclosure of Conflict of Interest