New Stormwater Management Regulations to Impact Private LandownersPrint PDF
After years of regulating stormwater only through the wetlands process, the Massachusetts Department of Environmental Protection (DEP) is proposing a radical change that will impact nearly all owners of existing developments, as well as new projects. The program is expected to have significant financial and operational implications for owners and managers of commercial, multi-family residential, industrial, and institutional properties. The proposed new stormwater management regulations will require owners of five or more contiguous acres of impervious surfaces (such as roadways, paved parking lots and roofs) to invest substantial time and money to closely monitor stormwater discharge, with additional requirements imposed on existing properties in the Charles River watershed and other waterways identified as “stormwater-impaired.” The DEP’s authority to enact these regulations comes from the Massachusetts Clean Water Act, M.G.L. c. 21, §26 et seq. and the Federal Clean Water Act, 33 U.S.C. §1251 et seq.
Who will these regulations affect?
The new regulations will impose stormwater management requirements on:
- All existing developments within the Commonwealth consisting of lots with five acres or more of impervious surfaces, or contiguous lots of five acres or more if there is a common stormwater management system or shared arrangements for the operation, maintenance or use of the impervious surface on those lots;
- All new developments involving at least five acres of impervious surfaces within the Commonwealth;
- Any repair or reconstruction of more than 5,000 square feet or 5 percent of a paved surface with an area of at least five acres (which is classified as a redevelopment);
- Any substantial improvement of a building or structure that includes repair of a roof, where the total cost of the project exceeds 50 percent of the fair market value of the building or structure before the start of construction, on property with at least five acres of impervious surfaces (which is also considered a redevelopment under the regulations); and
- All existing developments consisting of just two or more acres of impervious surfaces in the Charles River watershed.
Requirements under the regulations
All affected property owners must submit an Initial Certification to the DEP requesting coverage under the “Regulated Impervious Area General Stormwater Permit,” a draft of which has been released by the DEP, which sets forth requirements for monitoring stormwater runoff to comply with the regulations. If the DEP determines that a particular site requires additional mitigation, it may require and issue an individual permit with more specific stormwater management requirements. Annual Compliance Certifications must be submitted for each site covered under the general permit to evidence the site’s compliance with the permit specifications.
For those existing developments containing five or more acres of impervious surfaces, the general permit requires regular monitoring of stormwater management at the site and the development and implementation of a stormwater management plan contemplating “good housekeeping practices,” such as proper sweeping of debris and removal of ice and snow from impervious surfaces without allowing pollutants into stormwater runoff, as well as erosion control and hazardous waste management procedures. There are additional requirements imposed for the use and maintenance of equipment, goods and raw materials on non-residential sites. Non-residential uses that trigger these heightened requirements include commercial and industrial uses, hotels, nursing facilities, hospitals and campsites. Such sites are subject to additional measures, including, ensuring that all raw materials and/or equipment stored outside are maintained in a way that minimizes the risk that residue from those materials or equipment will contaminate stormwater discharge. The required good housekeeping measures for existing developments entail continuous self-monitoring, as well as the possibility of regular inspections and monitoring by the DEP.
All new developments, redevelopments, and impervious sites in the Charles River area will be subject to additional performance standards, such as required compliance with certain Massachusetts Stormwater Management Standards and implementation of low-impact development (LID) techniques and/or stormwater and infiltration best management practices (BMPs). For example, performance requirements imposed on a redevelopment may include the retrofitting of a parking lot by installing infiltration basins or chambers that will infiltrate at least 40 percent of the approximation of existing recharge volume based on soil type. However, it is worthwhile to note that there are off-site mitigation possibilities for both redevelopment and Charles River area projects, and certain redevelopment projects may be eligible for a variance from the additional performance requirements.
Timelines for compliance
All affected properties must submit an Initial Certification requesting coverage under the general permit within six months after the permit is issued. For those properties in the Charles River area, a design for structural stormwater controls must be submitted within four and a half years after coverage under the general permit is granted. Such properties have 10 years from the time the general permit is issued to implement the design.
For new developments or redevelopments, the LID techniques and structural stormwater BMPs required to comply with the regulations shall be designed and constructed on or before the date the development or redevelopment of the impervious surface is complete.
The regulations and general permit are not yet final, and may be changed in response to the public comment process, which includes public hearings held throughout the month of January and the DEP’s acceptance of verbal and written comments through March 11th.
As noted above, the DEP’s proposed regulations, if adopted, will place expensive responsibilities on all currently existing or proposed privately-owned sites with substantial impervious surfaces. For this reason, it is important for all potential owners or developers of such sites to review and understand the proposed regulations and their potential implications.
This update is for information purposes only and should not be construed as legal advice on any specific facts or circumstances. Under the rules of the Supreme Judicial Court of Massachusetts, this material may be considered as advertising.