Upper Mystic Lake Receives 'A+' Grade in EPA Water Quality Report Card

• Photo Credit: Google Maps Screenshot

ARLINGTON, MA—The U.S. Environmental Protection Agency(EPA), along with the Mystic River Watershed Association(MyRWA) reported grades between A and F for swimming and boating water quality. 

According to a Tuesday announcement by the EPA, Upper Mystic Lake received a grade of A+, meaning that the lake meets Massachusetts water quality standards for both boating and swimming approximately 95.9 percent of the time. However, Alewife Brook received a grade of D, meeting water quality standards just 49.5 percent of the time. 

"The grade demonstrates the recreational value of the Mystic River and Lakes. These are great places for canoeing and kayaking and we can safely enjoy swimming in the Upper Mystic Lake," said EkOngKar Singh Khalsa, Executive Director of the Mystic River Watershed Association in a statement. "The grade also underlines where there is room for improvement."

Grades were calculated by using a three-year rolling average for each segment, which involves calculating the year's current average in with the prior two years to produce a rolling average, according to the EPA. The Mystic Lakes showed high water quality for the second straight year, but many of the watershed's urban tributary streams water quality do not meet standards. 

The EPA attributed the poor water quality to bacterial contamination in tributary stream, with investigations indicating that the cause of the contamination is likely due to illicit sewer discharges to storm drain systems, as well as uncontrolled urban stormwater runoff containing pet and animal waste. 

"We have a lot of ongoing work to improve water quality in the Mystic and its tributaries, and this report card serves as motivation to continue that work. EPA and our partners are committed to improving water quality for residents of the Mystic Watershed, and while we have seen improvements, we still have a lot of work to do," said Curt Spalding, regional administrator of EPA's New England office in a statement. 

Grades are based on bacterial contamination found in samples collected by MyRWA volunteers over the past year at fifteen monitoring sites, as well as data collected by the Massachusetts Water Resources Authority. 

Here are the grades for the entire watershed, according to the EPA.