An important environmental regulatory case has been winding its way through the New York court system for several years. Now, after a January 2012 decision by the Supreme Court, Westchester County,¹ an initial ruling on appeal in November 2013 by the Appellate Division, Second Department,² and a second decision by the Second Department, issued in September 2014, in which it recalled and vacated its November 2013 ruling,³ the dispute finally reached the New York Court of Appeals. Oral argument was set to be held March 24, 2015, before the Court of Appeals.

The issue before the court is of great practical concern to small municipalities throughout New York. The court will decide whether the federal Clean Water Act (CWA)⁴ was violated when a general permit governing discharges from municipal separate storm sewer systems (known as MS4s) was approved by the New York State Department of Environmental Conservation (DEC) under the New York State Environmental Conservation Law (NYECL).

The Westchester Supreme Court ruled, in essence, that the general permit failed to ensure that small municipalities reduced their pollutant discharges to the “maximum extent practicable,” as required by the CWA. The Appellate Division reversed, finding that the DEC's general permit for MS4s did not violate the CWA.