Winthrop Beach water quality rating improves to 89%, Save the Harbor reports

For the first time in its testing history, Save the Harbor/Save the Bay has reported that every metropolitan beach from Nahant to Nantasket scored above 80% in its annual Water Quality Report Card. This is a historic achievement that reflects Save the Harbor’s 40 years of persistent advocacy, public investment in water infrastructure, and rigorous testing.

The Water Quality Report Card uses data collected by the Department of Conservation and Recreation (DCR) to assess water quality at public beaches from Nahant to Nantasket, including Lynn, Nahant, Revere, Winthrop, East Boston, South Boston, Dorchester, Quincy, and Hull (see table below). Water samples are tested for the number of colony forming units of enterococci bacteria; this is the standard unit used to determine safe swimming conditions, according to the US Environmental Protection Agency (EPA).

Save the Harbor/Save the Bay releases an annual Water Quality Report Card that uses data collected by the Department of Conservation and Recreation (DCR) to assess water quality at public beaches from Nahant to Nantasket, including Lynn, Nahant, Revere, Winthrop, East Boston, South Boston, Dorchester, Quincy, and Hull.

 South Boston’s beaches continue to lead the way. City Point maintained a perfect 100% water quality rating for another consecutive year. M Street Beach and Carson Beach posted a 94% and 95% rating respectively, continuing the region’s tradition of excellence. In addition, Nantasket Beach also scored very well last year, up from 92% in 2024 to 100% in 2025.

“It is gratifying to once again see so many of our spectacular urban beaches consistently testing at safe bacteria levels,” said Save the Harbor/Save the Bay’s Executive Director, Chris Mancini. “The region-wide scores above 80% are a testament to what sustained investment and scientific rigor can achieve. As we mark our 40th anniversary this year, we are as committed as ever to ensuring anyone can confidently get into or out on the water without worrying about bacteria and other pollution.”

Several beaches’ water quality ratings made remarkable comebacks. Nahant Beach rebounded to a 95% rating after four years of hovering around 80%. Meanwhile, Savin Hill Beach, Dorchester jumped to 100% after its dramatic drop to 68% last year.

“We’re proud that Massachusetts continues to have some of the cleanest urban beaches in the country,” said DCR Commissioner Nicole LaChapelle. “These results reflect decades of collaboration and stewardship focused on protecting and improving our public waterfronts, and we’re grateful for our partnership with Save the Harbor/Save the Bay in helping make that possible. It makes a real difference in how people experience our beaches and waterfronts. Clean water is essential, and access to it for recreation is a matter of equity. We remain committed to ensuring these coastal spaces stay resilient, accessible, and welcoming for generations to come.”

Meanwhile, Kings Beach in Lynn had the largest jump in its rating, receiving a 90% water quality rating. This is a significant jump over the six-year average of 69% and 2023’s record low of 55%. The pilot UV treatment program is one factor that contributed to the beach’s water quality improvement. Other factors include the dry summer weather and the improvement to the sewage pipes over the years.

“It is exciting to see America’s First Public Beach achieve a 95% water quality rating,” said MBC Commissioner Representative Jessica Ann Giannino (D-Revere). “Visitors can swim at Revere Beach with confidence while also enjoying the diverse, free programming Save the Harbor provides through its Better Beaches Grant Program, including weekly beach yoga, kayaking and paddleboard.

You can see the full chart and breakdown online here.