Charles River Nutrient Pollution Rises as Bacteria Levels Decrease

BOSTON, Massachusetts, April 19, 2006 (ENS) - Despite the unusually high amount runoff due to rainfall in Massachusetts during the spring of 2006, the Lower Charles River has attained its highest-ever grade from the U.S. EPA, a B+. The grade reflects the number of days the river meets boating and swimming standards during the previous calendar year and is based on measurements of bacteria levels in the water.

But even as bacteria levels are declining, another potentially serious problem has gotten worse - elevated levels of nutrients are entering the Charles River in stormwater runoff.

"We've made tremendous progress eliminating sewage from the river," said Bob Zimmerman, executive director of the Charles River Watershed Association. "That's just not good enough, however."

The Longfellow Bridge spans the Charles River, connecting Boston and Cambridge. (Photo by Ian Britton courtesy FreeFoto)
Last summer, toxic algae bloomed with great frequency and intensity. The proliferation of algae is caused in part by nutrients such as phosphorus entering the river and providing food for them.

"We have to fix the toxic algae blooms, and begin to figure out how to fix the sediments," said Zimmerman. He says the partnership between nongovernmental organizations, state and federal agencies will find ways to keep excess nutrients from fouling the river.

The EPA says the B+ grade shows that efforts over the past decade by government and local groups to restore the Charles to ecological health by reducing bacteria in the river are on track.

A generation ago the Charles was abandoned to polluted runoff, and in 1995 it received a water quality grade of D from the EPA. The turnaround is dramatic.

"The hard work that has gone into cleaning the Charles River is no magic trick," said Robert Varney, regional administrator for EPA’s New England office. "The improved water quality is the direct result of work and investment by state, federal and municipal governments, as well as environmental groups and a host of individuals committed to providing new life to this urban river."

For 2006, the Charles met boating standards 90 percent of the time, and swimming standards 62 percent of the time according to data collected by the Charles River Watershed Association between Watertown Dam and Boston Harbor.

Under a settlement between the EPA and the Massachusetts Water Resources Authority last year, sewage discharges to the river declined in 2006, and are expected to continue declining for the next eight years.

By the time this effort is completed in 2013, the Massachusetts Water Resources Authority will have reduced flows from sewer relief pipes by 99.5 percent, an effort Varney calls "impressive."

The section of the Charles River between the Watertown Dam and the New Charles River Dam at the Museum of Science is called the Lower Charles River. The Lower Charles is 8.6 miles long and is currently impaired by excess nutrients, mainly phosphorus.


Toxic blue-green algae infests a section of the Lower Charles River near the Museum of Science. (Photo by Dave Kaplan courtesy Charles River Wateshed Association)
"This year marks a real turning point for the Massachusetts Water Resources Authority's CSO [combined sewage overflow] program," said Massachusetts Water Resources Authority Executive Director Fred Laskey. "We've completed a number of important projects around the Harbor in the last few months.

The municipalities of the lower Charles continued to chip away at sewage flows from stormwater pipes, eliminating 7,500 gallons per day during 2006.

This is in addition to the more than one million gallons of sewage per day eliminated from storm drain systems since the EPA began the Charles cleanup effort in 1997.

Completion of the Stony Brook Sewer Separation project has reduced CSO discharges by an additional 44 million gallons a year.

Through this $45 million project, managed by the Boston Water and Sewer Commission, nearly 14 miles of new storm drain was installed to reduce sewer overflows to the Charles and remove stormwater from the sewer system, Laskey explained.

All these efforts have resulted in a more swimmable Charles River and Boston swimmers are beginning to return to the river with a one mile race scheduled for July 21.

Swimmers take a dip in the Charles River, now clean enough to enjoy after years of bacterial pollution. (Photo courtesy Charles River Swimming Club)
"Our upcoming Charles River one mile swimming race celebrates not only the tremendous work done thus far but the promise of the return of public river swimming," said Frans Lawaetz, president of the newly formed Charles River Swimming Club.

"Swimming in the Charles River is an important step to making the Charles River Parklands more active and accessible to the greater Boston community. The water is getting cleaner, and it is time that the public was able to benefit from it. This initiative will make the Charles River the first swimmable urban river in the United States," said Renata von Tscharner, president of the Charles River Conservancy, which is dedicated to restoring the Charles River.

While EPA’s ongoing work directed at bacterial sources will also help reduce nutrients and algae blooms, the agency has directed fresh energy toward controlling the amount and quality of stormwater, which carries nutrients into the river.

The EPA has issued stormwater permits to municipalities that require them to operate and maintain their storm drain systems, regulate construction sites, educate citizens about stormwater, and conduct other activities to minimize stormwater’s harmful effects.

To reduce nutrients and other pollutants, the agency will be reissuing and tightening these permits next year. In addition, the EPA will be examining other major sources of nutrients to the Charles and requiring them to take the necessary steps to reduce nutrient loading of the waterway.

Recently, the EPA and the state of Massachusetts proposed a total maximum daily load - a cleanup plan resulting from an assessment examining the impact of nutrients on the Lower Charles. This assessment determines what reduction in nutrients will be necessary to meet water quality standards on the River.


Sailboats on Boston's Charles River (Photo courtesy Massachusetts Water Resources Authority)
The results of the assessment indicate that nutrient loads from stormwater must be reduced by 50 or 60 percent to meet water quality standards.

"This won’t be an easy problem to solve," said EPA regional administrator Varney, "but we will be looking to all sources of elevated nutrients in storm water runoff to see that the necessary reductions will occur."

Some blue-green algal species known to be toxic have been consistently observed in the Lower Charles River during all summers when algal sampling has been conducted.

During the summer of 2006, a severe toxic blue-green algal bloom occurred in the Lower Charles, causing state agencies to post warnings for the public and their pets to avoid contact with that section of the river.

The major source categories of phosphorus to the Lower Charles River include stormwater from both overland runoff and piped drainage systems, illicit sanitary sewage discharges, combined sewer overflows, and discharges into the upper watershed above the Watertown Dam from similar sources, as well as discharges from several wastewater treatment plants.

Pollutants, such as phosphorus, that have accumulated on watershed surfaces are readily transported to the Lower Charles River by way of the stormwater drainage systems or overland flow during rain events.

Given the level of urbanization and the extent of impervious land cover, such as streets and parking lots, the Lower Charles River's watershed has lost much of its natural capacity to absorb rainfall and remove pollutants by filtering the runoff.

"The Charles River Watershed is a significant and important recreational resource to many residents and businesses in the Boston area," said MassDEP Acting Commissioner Arleen O'Donnell. "This cleanup plan charts a path for enhancing recreational opportunities and restoring ecological health to the river so all may continue to enjoy it."