New Rules for Small Municipal Separate Storm Sewer Systems

Nov 9, 2016

EPA’s new MS4 rules will affect construction sites throughout the country.

The Environmental Protection Agency (EPA), pursuant to the Clean Water Act (CWA), in 1999 issued rules for the regulation of water runoff on sites of less than one acre that are not connected to municipal sewage systems.

Permits are required for “small municipal separate storm sewer systems” or MS4s. Among the most common MS4s are those created to control water run-off on construction sites.

These rules have been viewed by environmentalists as too lenient. This triggered lawsuits and a review of the EPA’s Phase II Rule requirements that regulate MS4s.

An article by Arlene Haas in Burnham Nationwide discusses the legal history that has led to the implementation of the new Phase II directives and the impact they will have on contractors.

“In 1999, EPA promulgated the Phase II permit requirements that apply to small MS4s…To be eligible for the general permit, an MS4 only needed to file a Notice of Intent (NOI) stating how it planned to meet EPA requirements for best management practices (BMP).”

As with other EPA regulations, states are given the ability to enforce Phase II requirements by creating their own MS4 permit regulations. The state regulations are required to be at least as strict as the federal rules.

As Ms. Haas notes, in 2003 the Ninth Circuit Court of Appeals “required EPA to revise some parts of the Phase II regulations” Environmental Defense Center Inc. v. United States Environmental Protection Agency, 344 F3d 832 (9th Cir. 2003).

The EPA finally “published a [revised] rule in the Federal Register on January 6, 2016.” The required period for public hearings has expired and the new permitting rules will go into effect this month.

The construction industry is concerned, according to Ms. Haas, that the new rules will make it more difficult, time consuming and expensive to obtain building permits. This is probably an accurate assessment.



Construction Sites and EPA’s Changing Small MS4 General Permit Rule, Arlene Haas, Burnham Nationwide, Oct. 27, 2016.