The United States Environmental Protection Agency (USEPA) has issued a first-of-its-kind stormwater permit covering three major watersheds in the Greater Boston Area. The proposed regulations would impose major requirements to all covered facilities with over an acre of impervious surface, such as asphalt or concrete, across the Charles, Mystic, and Neponset River watersheds. The permit, issued in draft format by USEPA on October 31, would require all commercial, industrial, and institutional facilities operating within these three watersheds to drastically reduce the concentrations of phosphorous in their stormwater runoff.
Impervious surfaces significantly contribute to stormwater runoff, carrying pollutants like phosphorus into nearby waterways. Phosphorus, a nutrient pollutant common in urban stormwater runoff, can lead to degradation of water quality, eutrophication, and harmful algal blooms. The three rivers targeted by this draft permit all have long histories of phosphorous impairment.
New Permit Requirements
Facilities covered by this draft permit will need to develop a Stormwater Pollution Control Plan to remove phosphorous by 60-65 percent and implement structural and/or non-structural stormwater control measures (SCMs) to reduce phosphorous loading.
- Structural SCMs include green infrastructure practices, such as stormwater wetlands, rain gardens, or vegetated swales to filter and slow down runoff.
- Non-structural SCMs include engineering and maintenance controls, such as street sweeping, catch basin cleanout, and collecting leaf litter to prevent pollutants from entering the water system.
Compliance timelines will vary based on total acreage of impervious cover.
Further Information
The regulations are currently open for public comment until January 29, 2025. More information can be found here.
Questions? We’re here to help
Navigating compliance requirements can be complex, but EHS Support is here to help. With expertise in hydrogeology, chemistry, ecology, biology, and engineering, our team delivers practical solutions tailored to your needs. Whether you’re navigating compliance challenges or crafting custom stormwater solutions, we’re with you every step of the way. To discuss any questions or concerns regarding the new draft permit requirements, please contact craig.drennan@ehs-support.com.
