The environmental watchdog group Save the Sound on Thursday released its 2021 Beach Report, giving most area public beaches high scores for water quality — with the exception of Rocky Neck State Park in Niantic and Greens Harbor Beach in New London.

Six of the beaches identified by the group as the state's 10 best beaches were located in New London County.

The analysis evaluated weekly fecal bacteria levels and assessed rainfall data to show how wet or dry conditions influenced water quality at the beaches.

Tracy Brown, regional director of water protection for Save the Sound, said one of the big takeaways from the report is how variable conditions can be from one beach to the next in the same general area.

"These pollution sources are so local, you can have beaches with bad grades just down the road from beaches with A+ grades," she said over the phone Thursday. "So it really points to the need for local action."

One example of that phenomenon can be seen at New London's Ocean Beach Park, which earned an A+, and Greens Harbor Beach, which got a D.

Data showed Ocean Beach passed all 30 of its water quality tests last year, while Greens Harbor Beach failed 25% of the 16 water quality tests performed there.

The disparity in relatively close beaches also was evident at Rocky Neck State Park in Niantic, which received a C-, and Sound View Beach in Old Lyme, which got an A-.

Brown said the Greens Harbor Beach and Rocky Neck situations were interesting because both of them had poor results in both wet and dry weather. That means it's not just rain causing stormwater runoff that delivers pollutants into local streams, rivers and eventually the coastal waters.

She said the most likely factors in cases like those involve geese or sanitation systems.

She noted that Greens Harbor Beach had a particularly "significant failure" the week of Aug. 24 last year. Data on the organization's website shows fecal bacteria levels that week of 2,000 colony forming units per 100 milliliters, when 104 or more is the threshold for beach closure. Historical data on the site shows similarly high numbers during parts of July and August off and on since the mid-2000s.

When asked what can be done to alleviate water quality problems related to waterfowl and sanitation concerns, she pointed to Orchard Beach in the Bronx, where she had announced the report results with Save the Sound that morning.

"That is an urban beach with tens of thousands of visitors on the hottest days of the summer, really close to NYC, and they have 'A' water quality," she said.

Attendants comb the beach for goose poop in the mornings and patrol to keep the waterfowl from getting on the beach and all the toilets at the beach are in good repair, according to Brown.

Mayor Michael Passero said the city is "not sure" what's causing the water quality problems at Greens Harbor Beach. He said he was hopeful the large-scale drainage and park improvement project will improve the water quality over time.

The project, initially intended to correct historic flooding in the roadway and reconstruct the drainage system that spills stormwater into Greens Harbor Beach, was expanded to account for water draining into the park and roadway from a 60-acre watershed area.

Water traditionally has flooded Pequot Avenue, kept portions of the park wet and carried sediment and contamination into the harbor, leading to swimming bans at the beach.

"However, we think there's other factors now including waterfowl and the marinas that are surrounding that beach, sort of locking it in," Passero said.

The mayor said he was not aware of ways to keep geese out of the area. He also said he was not aware of the significantly high levels of fecal bacteria noted in the data from August of last year.

"It's on our radar," he said of the overall water quality issue. "We've pretty much eliminated stormwater runoff as the source because we've contained that. It's on to figure out what the other source of the contamination is."

Department of Energy and Environmental Protection environmental analyst Tracy Lizotte said Thursday she believes bird poop is responsible for a large part of Rocky Neck State Park's water woes. She cited a large bird population in one large and environmentally significant wetland area that Bride Brook feeds into, describing it as "pretty fertile ground."

"We actually have the east end of the beach sort of what we consider permanently closed because of the high bacteria levels," she said.

Lizotte said there's not much that can be done about wildlife in the protected wetlands. The area is part of the Bride Brook system that features one of the Long Island Sound's largest herring runs, according to Lizotte.

"You really can't go in and destroy wetlands that is a wildlife habitat," she said. "It's a very important functioning wetland."

As far as septic systems go, she said numerous sanitary surveys, samples collected upstream of the Route 156 bridge, and a dye study performed by the federal Environmental Protection Agency to "see how things were flowing" have not turned up any results indicating a problem.

Lizotte said the agency is "90% sure" that birds in the wetlands are the primary cause of the water quality problems at the beach.

Brown encouraged municipalities or agencies with poorly rated beaches to contact Save the Sound to talk about ways to improve water quality and make sure the beaches stay open for all.

e.regan@theday.com

2021 Beach Report

The grades for the region are as follows:

Dubois Beach, Stonington, A+

Noank Dock, Groton, A+

Esker Point Beach, Groton, A+

Eastern Point Beach, Groton, A+

Greens Harbor Beach, New London, D

Ocean Beach Park, New London, A+

Waterford Town Beach, Waterford, A+

Pleasure Beach, Waterford, B

Hole in the Wall Beach, A+

McCook Point Beach, Niantic, A+

Rocky Neck State Park, Niantic, C-

Sound View Beach, Old Lyme, A-

White Sands Beach, Old Lyme, A+