Fear not — Boston’s beaches are safe for swimming

First, don’t be fooled by appearances. Algae, foam, and silt do not necessarily equal bacteria. Sometimes the ocean can be gross to look at but still safe to swim in.

Second, combined sewer overflows are not the primary cause of contamination on most coastal beaches. More often, significant rainfall causes waste from streets, lawns, and pipes to flow into the ocean. Waiting at least 24 hours after a heavy rain lets bacteria break down naturally, and the tides flush out the area.

Let’s keep legislating and funding infrastructure projects to eliminate combined sewer outflows, contaminated stormwater, and runoff. However, leading with fear erodes people’s trust in these reliable urban natural resources.

Massachusetts has the third-safest beaches in the country, and South Boston is proudly home to some of the cleanest urban beaches nationwide — safe to swim in practically every day of the year.

Chris Mancini

Executive director

slash the Harbor/slash the Bay

Boston

Your article about bacterial levels forcing closures at the state’s beaches implies that combined sewer overflows containing sewage and stormwater are causing beaches to close in Boston. But state water quality testing shows that at least in Boston Harbor, that is not the case.

Boston beaches are actually among the cleanest urban beaches in the country. This is thanks in part to the Massachusetts Water Resources Authority having built a massive underground tank in Dorchester that stores stormwater runoff for later treatment at MWRA’s Deer Island plant.

While combined sewage systems still exist in the MWRA system, the fecal bacteria counts downstream of active combined sewage outfalls are actually lower than upstream — and often low enough for safe swimming.

The Wastewater Advisory Committee to the MWRA supports reducing the amount of pollution entering all our water bodies, but the evidence shows that stormwater appears to be the source of most of the problem. Addressing the cleanliness of stormwater, or allowing it to seep into the ground where it falls, would make a greater impact on the number of beach closures.

Kannan Vembu

Chair

Wastewater Advisory Committee to the MWRA

Natick