Massachusetts DEP Proposes Regulations Implementing Broad Statewide Stormwater Discharge Permitting Program

Beveridge & Diamond, P.C. - Massachusetts Environmental, Land Use & Real Estate Alert, 2008

The Massachusetts Department of Environmental Protection (“DEP”) proposed new regulations on November 17, 2008 implementing a new Stormwater Management Program that would significantly expand the scope of stormwater permitting in the state.  Under the regulations,  owners of property containing five (5) or more acres of impervious surfaces including paved areas and roofs would be required to apply for coverage under either a general or individual DEP permit.

The proposed regulations also are intended to allow DEP to assume delegation from the U.S. Environmental Protection Agency (“EPA”) to administer the National Pollution Discharge Elimination System (“NPDES”) stormwater permit program.  Currently, EPA administers the NPDES stormwater program in Massachusetts, under which certain industrial, municipal, and construction sites must apply for coverage under either an individual or general permit.

The permitting requirements proposed by DEP would impact owners of sites containing “Regulated Impervious Areas” (“RIA”), defined as five or more acres of impervious surfaces located on a single lot or two or more contiguous lots.  Lots will be aggregated for the purposes of determining RIA where, for example, stormwater runoff is directed to the same on-site stormwater management system or if there are shared paved parking areas or buildings. 

In the proposed regulations, DEP has also reserved the authority to designate for regulation areas of less than five acres of impervious surface if it determines control of discharges from such smaller sites is necessary to achieve or maintain compliance with the Massachusetts Surface Water Quality Standards.  Similarly, DEP has reserved the authority to designate additional activities as requiring coverage under either a general or individual permit in cases where stormwater discharge is contaminated, subject to certain effluent limitations, or associated with construction activities not adequately regulated by the NPDES Construction General Permit.

Owners of properties containing RIA would be required to apply for coverage under a general permit, which has not yet been published.  Applicants would be required to provide a Stormwater Management Plan, undertake “good housekeeping” practices such as regular parking lot sweeping, and implement standard operating procedures to manage potential pollutants from activities such as snow removal and deicing activities. 

In addition to the basic requirements of the general permit, the regulations provide additional performance standards applicable to development, redevelopment, and discharges to impaired waters. 

These additional performance standards incorporate certain existing DEP policies and guidelines, including elements of the Stormwater Management Handbook.  For example, development of impervious surfaces within an existing site containing RIA will be required to implement Low Impact Development techniques or Best Management Practices capable of meeting Standards 3 through 6 of the Stormwater Management Standards as described in the Massachusetts Stormwater Handbook.  Off-site mitigation will be available for redevelopment projects only.

Additional provisions in the extensive proposed regulations provide that municipalities may be authorized by DEP to administer a Qualifying Local RIA Program, detail when individual permits may be required by DEP, and address regulation of small municipal separate sewer systems or “Small MS4s”.

The proposed regulations are available at: http://www.mass.gov/dep/service/regulations/proposed/31421new.doc. Public comment on the proposal is not yet open as of the date of this alert.

For further information, contact Marc J. Goldstein at mgoldstein@bdlaw.com or Krista L. Hawley at khawley@bdlaw.com.