The U.S. Environmental Protection Agency (EPA) encourages the use of green infrastructure to manage stormwater discharges. While local codes, stormwater utilities, and other innovative financing mechanisms often create standards and incentives for green infrastructure, regulatory drivers such as permits can also provide an effective foundation for consistent implementation of green infrastructure at the local, state, or cross-jurisdictional level. This compendium presents a variety of existing permitting approaches that encourage or require green infrastructure in municipal separate storm sewer systems (MS4s); it also provides excerpts from current state and EPA MS4 permits and examples of how MS4 permittees implement green infrastructure permit requirements. These excerpts and examples can serve as a road map for permitting authorities and permittees that are interested in incorporating green infrastructure into permitting programs or identifying successful strategies to maintain compliance. To develop this compendium, EPA reviewed final individual and general National Pollutant Discharge Elimination System (NPDES) MS4 permits issued through August 2021.
This compendium is part of a series of compendia of MS4 permit excerpts and is intended to serve as a snapshot of permit provisions. As permits are reissued or revised, EPA may update this compendium to include more recent examples and new information. EPA also welcomes input on this compendium and expects to update it as appropriate based on the comments received. EPA notes that the inclusion of any particular permit example should not be read as an endorsement of the entire approach taken in that permit, nor should it be read as EPA’s independent determination that the permit terms meet the Phase I and/or Phase II MS4 requirements.
In addition, this document does not impose any legally binding requirements on EPA, states, or the regulated community and does not confer legal rights or impose legal obligations upon any member of the public. EPA made every attempt to ensure the accuracy of the examples included in this document. In the event of a conflict or inconsistency between this compendium and any statute, regulation, or permit, it is the statute, regulation, or permit that governs, not this compendium. For more information about the NDPES Stormwater Program, visit www.epa.gov/npdes/stormwater.