5 New Counties, 8 Municipalities Tapped For Phase II MS4 Stormwater Permits

MACo has learned that the new Phase II Municipal Separate Storm Sewer System (MS4) permit requirements will be published in the December 23rd edition of the Maryland Register. In addition to the permitting requirements, 5 new counties and 8 new municipalities will be proposed for Phase II status.

The National Pollutant Discharge Elimination System (NPDES) MS4 permit system was created by the United States Environmental Protection Agency (EPA) in 1990.  The permits are required for certain local governments (counties and municipalities) and the Maryland State Highway Administration (SHA) and dictate the water quality standards the permitted entity must comply in treating and preventing stormwater runoff.  The stormwater runoff requirements are based on water quality standards set under the federal Clean Water Act (CWA) and the permits have a 5-year term.  In Maryland, Maryland Department of the Environment (MDE) sets the individual permit requirements and issues the permits, subject to EPA sign-off.

MS4 permits are divided into Phase I and Phase II categories.  Phase I permits are individualized and apply to “large” local governments (those with a with a population greater than 250,000), “medium” local governments (those with a population between 100,000 and 250,000), and SHA. The permit requires them to treat or prevent pollution in stormwater runoff to the maximum extent practicable (MEP) in order meet federal water quality standards under the Clean Water Act (CWA). The EPA created Phase II stormwater requirements in 1999.  The permits apply to certain local governments that have a population of at least 1,000.  A Phase II permit holder must implement six measures:  (1) public education and outreach; (2) public participation and involvement; (3) illicit discharge detection and elimination; (4) construction site runoff control; (5) post-construction runoff control; and (6) pollution prevention/good housekeeping.

Currently, 12 counties are subject to MS4 permits. There are 10 counties with Phase I permits: Anne Arundel, Baltimore, Baltimore City, Carroll, Charles, Frederick, Harford, Howard, Montgomery, and Prince George’s. There are 2 counties with Phase II permits: Cecil and Washington.

The permits have spawned significant litigation over the past several years and it is possible a new round of litigation will emerge over the proposed Phase II requirements and designations.

[UPDATE: Subsequent to the publication of this article, MDE clarified its initial numbers to say that 8 municipalities, rather than the 34-36 initially reported, will be proposed for Phase II status. This article has been updated to reflect that new municipality number. The proposed 5 counties number has not changed.]

Useful Links

Prior Conduit Street Coverage of MS4 Permits

MDE MS4 Permit Webpage