Charles River Water Quality Sinks To 'B'

BOSTON — After a dramatic upturn in 2013, the water quality of the Charles River took a bit of a dip, according to the U.S. Environmental Protection Agency. The EPA awarded Charles River a grade of "B" for bacterial water quality for 2018. Much of that lower grade had to do with wetter weather sending toxins from roads into the drains and out to the Charles.

During dry weather, 66 percent of the samples met the state's criteria for swimming and 94 percent of the Charles River samples met the state's bacterial water quality standards for boating, the EPA announced. In wet weather, the percentage dropped significantly for swimming, to 47 percent, and only slightly for boating at 91 percent. it is primarily the low wet-weather swimming percentage that drove the grade down in 2018.

"The B grade is a reminder that while the Charles is much cleaner than it was when the first grade was given — a D in 1995 — our work is far from over," said Charles River Watershed Association Executive Director Emily Norton. "Today the biggest challenges facing the river are stormwater runoff and extreme weather from climate change."

The grade for 2018 was measured by taking samples during both wet and dry conditions. During wet weather conditions, higher bacterial concentrations and poorer water quality due to sewer overflows and polluted stormwater runoff are more likely.

Norton said the watershed association was working with the municipal leaders to implement nature-based solutions that reduce stormwater pollution, while also building climate resilience as the region experiences more storms, more rains, more frequent drought and more extreme heat.

While the grade dipped this year, the EPA has seen significant improvement in the river's overall water quality since the first report card in 1995, when the river scored a "D." Back then it met boating standards 39 percent of the time and swimming standards 19 percent of the time.

"The Charles River has been in the 'B' or better range for bacterial sampling for the last 18 years," said Acting Regional Administrator Deb Szaro in a statement, chalking up the improvements to a local partnership working hard to clean up the river.

The Charles River grade of an A means water testing almost always met standards for boating and swimming. A grade of B- met standards for almost all boating and some swimming. Just like in school, it's possible to get a C, D or F, too.

The improvements are also because of significant reductions in the amount of sewer overflow discharges to the river over the past 24 years, enforcement of standards and removal of cracked and leaking sewer pipes or improper sewer connections to the storm drain system.

But there are other challenges.

While bacteria levels in the Charles have declined over time, algae blooms have become a major problem in the river. These blooms — some of which include toxic cyanobacteria — are driven by excessive phosphorus in stormwater runoff.

In response, there are plans in the works to update stormwater management efforts across the state, according to the EPA.

This year, as it has done for the past five years, the EPA launched a water quality monitoring buoy in front of the Museum of Science in the Charles River Lower Basin. This buoy measures water quality in near real time. The data is streamed-live on EPA's Charles River website, as well as to a Charles River exhibit in the Museum of Science.

Related:

• Charles River Gets 'A-' For Water Quality, Report Shows
• Oil Spill In Charles River Contained, Investigation Underway

Patch reporter Jenna Fisher can be reached at Jenna.Fisher@patch.com or by calling 617-942-0474. Follow her on Twitter and Instagram (@ReporterJenna).