MS4 Needs Assessment Survey Results

In 2018, the Water Environment Federation’s (WEF) Stormwater Institute (SWI) conducted a national survey of municipal separate storm sewer system (MS4) permittees. The primary objectives of this survey were to identify the needs of these permittees and to better understand the MS4 stormwater program challenges. In total, the survey received 622 responses from 48 states, including the District of Columbia. Approximately 25% and 65% of respondents represented Phase I and Phase II MS4 permittees, respectively. Non-traditional Phase II permittees and state transportation departments (DOT) accounted for 7% and 3% of the survey sample, respectively. Respondents were generally representative of the geographic distribution of MS4s across the United States