By Alban Murtishi
Masslive.com
The Charles River only met the EPA’s standard of safe swimming water quality 55 percent of the time in 2016, prompting a downgrade of the river’s overall quality from a B+ to a B.
For the past 22 years, the EPA has published the Charles River Report Card to measure the level of bacterial water quality for swimming and boating in the river.
Every month, employees of the Charles River Watershed Association collect water samples at 10 locations in the lower Charles River and analyze them for bacterial contamination. They also track the levels of phosphorous, algae and general pollutants in the water.
“We have made significant progress targeting bacterial sources of pollution in The River. But, there continue to be problems with excessive amounts of nutrients entering the river, especially phosphorus,” a post by the EPA reads.
When the report card was first published in 1995, the Charles River received its lowest grade ever: a D.
In those days, EPA scientists determined, the Charles River was safe to swim in about 19 percent of the time, and was safe to boat in around 39 percent of the time.
In addition to the quality of samples, grades are also determined in comparison to the previous year, and the Charles River has been on an upward trend.
By the year 2000, the grade had steadily gone up from a D- to a B. It dipped again in 2003 to a B-, but then went up again in 2004 to a B+.
The river received its highest mark in 2013, when it received an A-. That year, the Charles River water quality was safe for boating 96 percent of the time and safe for swimming 70 percent of the time.
The 2016 grade marks the first downgrading for the river in two years. It also marks the lowest percent for swimming water quality since 2011.
According to the EPA report, the slightly lower grade for 2016 might have been caused by the fact that seven out of 10 samples were collected during or after a rain event.
Additionally, 2016 saw the Charles River busier than ever, with many swimming and boating events taking place on the river.
The Charles River Initiative, a consortium of nonprofits and private institutions dedicated to keeping the river safe, said the improved quality of the river has been driven by increased public awareness.
“Citizens have been the driving force behind the Charles River Initiative and they can continue to help improve water quality in the River while monitoring progress themselves,” a release by the group reads.