Mystic River Watershed Water Quality Grades and Compliance Rates - Calendar Year 2019 WAKEFIELD BURLINGTON WOBURN STONEHAM WINCHESTER LEXINGTON MALDEN MEDFORD ARLINGTON SOMERVILLE BELMONT CAMBRIDGE Grade Water Segment Average Compliance Rate WILMINGTON A Upper Mystic Lake 92.9% A Chelsea River 90.4% A- Mystic River (Fresh Water) 85.5% B+ Belle Isle Inlet 83.8% B+ Mystic River (Salt Water) 83.8% B Island End River 76.3% B- Meetinghouse Brook 72.6% C Maiden River 63.9% C- Aberjona River- 55.7% D+ Little River 50.7% D+ Mill Brook 50.5% D Alewife Brook 45.6% D- Mill Creek 41.3% F Winns Brook 36.3% REVERE WATERTOWN Average Compliance Rates for Swimming and Boating Standards ¦¦ [ B 1 c 70-56 Monitoring Points Q Mystic River Watershed Association /\ Massachusetts Water Resources Authority Mystic River Watershed ~ Town Boundary 2019 Mystic River Watershed Report Card (based on 2017-2019 bacterial data) ------- |