EPA, Massachusetts Seek to Reduce Algal Blooms in Charles River


EPA and the Massachusetts Department of Environmental Protection (DEP) announced that they will work together to reduce stormwater pollution in the Charles River.

The federal agency will seek to reduce phosphorus discharges to the lower Charles River by 54 percent. Phosphorus, a nutrient, is responsible for the psychedelic blue-green algal blooms that plagued the Charles for the last two summers.

Due to a concerted decade-plus effort by EPA, DEP, local governments and groups such as the Charles River Watershed Association, progress has been made in the last decade in making the river safe for recreation, officials said. For example, within the past few years, the Massachusetts Water Resources Authority has committed to eliminating 99.5 percent of all combined sewer overflows to the Charles and Boston coastal areas.

"We've made tremendous progress in the Charles River, but solving the issue of algal blooms will require us to focus on smaller contamination sources, such as stormwater," said DEP Commissioner Laurie Burt. "Reducing phosphorus levels is the next step toward restoring the river to its natural beauty."

EPA is seeking to reduce algae in the river by approving a total maximum daily load (TMDL) for discharges of phosphorus into the lower Charles River. A TMDL determines how much of a pollutant can be put into a body of water before it has harmful effects. EPA and DEP have developed and approved the new limits on phosphorus to the lower Charles using extensive data collected in the river over the last several years.

The TMDL forms the scientific basis for taking specific actions to reduce the release of phosphorus into the river. Phosphorus enters the river by a number of routes, some of which are already controlled by permits issued by EPA and DEP. These include combined sewer overflows, illicit connections through which sanitary sewage seeps into storm drains, and outflows from wastewater treatment plants. While all of these sources have come under stricter discharge limits in recent years, a major uncontrolled source of phosphorus is stormwater runoff, rainwater and snowmelt that carry contamination into the river.

EPA and DEP will work with municipalities and other dischargers to reduce their contribution of phosphorus to the Charles. Techniques to reduce phosphorus in stormwater include the construction of infiltration chambers, the installation of permeable pavement that enhances the return of water to the soil, the use of high efficiency street sweepers, and other low-impact development methods.

Explosive algae growth has turned the river a day-glow green during the warm spells of the last two summers. That vivid color indicates the presence of "blue green" algae, actually a form of bacteria known as Cyanobacteria, whose cells may release a toxin when they die. Exposure to the toxin can cause skin rashes and irritate the nose, eyes or throat, and if ingested can lead to serious liver and nervous system damage. Other harmful affects of the algae include reduced water clarity, nuisance scum, and reduced oxygen in the water. Oxygen is necessary for a healthy fish habitat.

More information on EPA's Clean Charles Initiative can be found at http://www.epa.gov/region1/charles.

comments powered by Disqus