On May 10, 2018, the U.S. Environmental Protection Agency (“EPA”) announced that it was issuing two new Municipal Stormwater Sewer System (“MS4”) general permits for small MS4s in New Hampshire and Massachusetts, respectively.  In each state, EPA is the Clean Water Act permitting authority. 

These permits replace the MS4 permits for both states that were issued in 2003 and have been administratively continued since 2008.  EPA previously sought to issue updated permits, but that effort stalled due to litigation over the terms of the permits as well as extended comment periods on both permits.  Litigation regarding the Massachusetts permit was resolved in 2017, but permit issuance was postponed for one year at the request of the petitioners, with the result that both the Massachusetts and the New Hampshire updated general permits will go in effect on the same date – July 1, 2018.  MS4s must file Notices of Intent for coverage under the permits within 90 days thereafter (October 1, 2018). 

There are approximately 260 small MS4 municipalities in Massachusetts and 39 in New Hampshire.  A number of so-called “non-traditional” MS4s (owned and operated by the state, county or federal government, including transportation agencies) are also covered under the permits.

The new permits include the same six “minimum control measures” as the 2003 permit:

• Public Education and Outreach
• Public Participation
• Illicit Discharge Detection and Elimination
• Management of Construction Site Runoff
• Management of Post-Construction Site Runoff
• Good Housekeeping in Municipal Operation.

In general, the new permits are substantially more robust, detailed, and prescriptive than the 2003 permit.  For example, permittees will be required to demonstrate the effectiveness of their public education and outreach efforts and promptly modify their methods as needed.  More extensive measures must be taken by MS4s that discharge to impaired waters, both those with an EPA-approved Total Maximum Daily Load (“TMDL”) and those without an approved TMDL.  In addition, the new permits require inspection and sampling under both dry and wet weather conditions, including monitoring and sampling of stormwater outfalls.

Other New England states have been delegated stormwater permitting authority by EPA.  Connecticut reissued its MS4 permit with an effective date of July 1, 2017; however, a proposed draft permit for the Connecticut Department of Transportation has not yet been issued.  The 2013 Maine MS4 permit is in the process of being updated, but likely will be administratively continued past its July 1, 2018 expiration date.  The Rhode Island MS4 permit expired in 2008 and since has been administratively continued.  In February 2018, Vermont proposed a new draft MS4 permit to replace a 2012 permit that has been administratively continued past its 2017 expiration date.