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.