University of California Water Resources Center

In this report, we compile empirical evidence regarding federal and state trends in the use of Supplemental Environmental Projects (SEPs). Our primary interest is in SEPs associated with enforcement of the federal Clean Water Act (CWA). We move from briefly examining the broadest trends—federal and state use of SEPs—to more particular emphasis on the experience of California’s State Water Resources Control Board (SWRCB) and Regional Water Quality Control Boards (RWQCB) with SEPs. Drawing on state and regional enforcement databases as well as extensive interviews with agency enforcement personnel, we evaluate the use of SEPs by the regional boards in California and offer recommendations for improving the use of this important policy tool.