The U.S. Environmental Protection Agency (EPA) announced a targeted effort to apply more stringent controls on stormwater pollution in the Charles River watershed in Eastern Massachusetts, where stormwater containing high levels of phosphorus is a chief culprit in dramatic algae blooms—including toxic cyanobacteria—that have plagued the river in recent years. The EPA action will require certain industrial, commercial, and residential facilities in the towns of Milford, Franklin, and Bellingham, Mass., with two or more acres of impervious area (parking lots, roofs, roadways, et cetera) to operate under a Clean Water Act permit. EPA is accepting public comments on this action.

In a separate but closely related action, the Commonwealth of Massachusetts is enacting a statewide requirement for facilities with five or more acres of impervious area to reduce stormwater runoff. Under both the federal and state actions, new requirements will be phased in to reduce polluted stormwater runoff at sites with large paved areas, including shopping malls and industrial areas. While the statewide standard will be five acres, the state is proposing to match EPA’s two-acre requirement in the Charles River watershed, where a higher level of control is needed to address chronic water quality problems.

"Until now, managing stormwater has largely been the responsibility of the cities and towns," said Laurie Burt, commissioner of the Massachusetts Dept. of Environmental Protection. "It is critical now for other property owners to step up to the plate and do their part. This new program creates a level playing field by requiring that the responsibility for managing stormwater be shared by municipalities and private property owners."

The new EPA requirements are being piloted in the three communities—Milford, Franklin, and Bellingham—at the upstream end of the Charles River for commercial, industrial, and high-density residential facilities with two or more acres of impervious area. EPA will require these facilities to apply for a Clean Water Act permit for stormwater discharges that eventually reach the Charles River. The permits will require that these facilities reduce phosphorus discharges by 65 percent through a variety of stormwater management practices. Ultimately, these requirements will likely apply to the entire Charles River watershed.

High levels of nutrients, especially phosphorus, in the past several years have caused the Charles River and other waterbodies to turn a bright shade of blue-green during summertime algae blooms. The color is caused by blooms of cyanobacteria, which can be harmful to both people and pets.

"EPA’s extension of the Clean Water Act to include polluted stormwater runoff from commercial and industrial parking lots is both bold, and necessary," said Bob Zimmerman, executive director of the Charles River Watershed Association. "We will never clean up urban rivers without cleaning up existing runoff from pavement. This bold move will aid cities and towns meet their requirements, and help restore a more natural balance to the way water works in metropolitan regions, not just in the Charles River, but ultimately across the United States."

"It is time for existing commercial and industrial developments to do their fair share to clean up the stormwater pollution that is threatening public health and recreation in New England’s waters," said Christopher Kilian, director of the Conservation Law Foundation’s Clean Water and Healthy Forests Program. "The EPA took this precedent-setting action because the Clean Water Act’s mandates don’t allow this pollution to go unaddressed."