NAHANT — With Memorial Day signaling summer’s unofficial start, Nahant Beach ranks among the cleanest beaches of the Boston region’s sandy stretches.
Environmental group Save the Harbor/Save the Bay (SH/SB) gave Nahant Beach a “primary beach safety score” of 100 percent based on ocean water tests for bacteria in its self-titled beach report card.
Nahant Beach received a similar score from SH/SB in 2016.
In 2017, overall water quality safety rating for Boston Harbor’s regional beaches was 94 percent, the percentage of time beaches were assessed by Save the Harbor/Save the Bay to be safe for swimming.
This was a slight decline from last year’s score of 96 percent, but unusually dry weather in the 2016 sampling season likely led to relatively high scores for that year, as rainfall and the associated polluted runoff from streets and storm drains often has an adverse effect on water quality.
The total rainfall during the 2017 sampling season was more than double the previous year, and the distribution, frequency and intensity of summer storms were somewhat atypical.
With four sampling locations tested weekly for bacteria, Nahant had no instances where bacteria samples exceeded counts in 2017, according to SH/SB.
The environmental group releases a report on beach water quality, giving credit to the state Department of Conservation and Recreation for overseeing beach operations and Metropolitan Beaches Commission Co-Chairs state Sen. Brendan Crighton of Lynn and state Rep. RoseLee Vincent of Revere.
SH/SB’s self-titled report card also ranks King’s Beach favorably, noting King’s “consistently lagged behind other area beaches in water quality since 2012,” when the beach health safety assessment began.
King’s scored 92 percent this year, compared to last year’s 83 percent.
“While this year’s results may well be an anomaly … both Lynn and Swampscott have planned improvements to their sewer and stormwater systems, which we expect will result in significant improvement in water quality on King’s Beach when they are completed,” the report stated.
Other beaches tested with results cited in the report include Constitution Beach, Malibu Beach, Tenean Beach, and Wollaston Beach.
“Changes in the intensity and frequency of summer storms may well explain the variations we saw on some of our beaches in 2017, which is why we urge the public to use the multi-year averages we have provided in comparing relative water quality among beaches,” the report stated.