Save the Sound’s 10th season of conducting fecal bacteria monitoring in the western Long Island Sound was our biggest yet, with 777 water samples collected. The results from the 2023 monitoring season show that 64 percent of the samples collected across 65 sites from Greenwich, CT, through Westchester County, and into Queens and Nassau County, failed to meet safe swimming criteria. That overall failure rate, measured against criteria used in Connecticut and New York to monitor and manage beaches, is up 8 percent from 2022, and up 15 percent from 2016, when we first posted overall pass-fail rates following our monitoring seasons. Each of these failures represents a falling-short of the promise of the Clean Water Act, which guarantees swimmable and fishable waters.
The failure rate for samples taken in wet weather conditions (73 percent), when a half-inch of rainfall or more occurred in the 72 hours prior to collection, decreased by 1 percent. As in all past years, fecal contamination levels were higher after rainfall at most locations. Dry weather samples failed 44 percent of the time, up 3 percent from 2022.
“Some of the increase can be attributed to the addition of three new stations this season, all in Westchester County: two on Blind Brook and one on a tributary to Beaver Swamp Brook,” said Save the Sound director of water quality Peter Linderoth, who noted that 32 of the 36 samples (88.9 percent) from those sites failed. “Our staff will be conducting field investigations around these stations with a focus on identifying and correcting any sources of pollution we find, ensuring that water quality meets the swimmable, fishable objectives outlined in the Clean Water Act.”
Samples are collected by community scientists, trained by Save the Sound staff, once a week over the course of the 12-week monitoring season. Those samples are delivered to the John and Daria Barry Foundation Water Quality Lab in our Larchmont office, where they were analyzed by our full-time and seasonal staff for the presence of fecal indicator bacteria: Enterococcus in marine water, E.coli in freshwater. The level of FIB in a sample is used to determine whether waters are safe for swimming.
“I want to thank our summer interns and the 28 volunteers who conducted sampling for us this season. We were able to consistently and successfully test 65 sites, thanks to the hard work and dedication of our volunteers” said environmental analyst Ameera Khan, who oversees sample collection for the bacteria monitoring program.
In the 2023 season, rivers remained the most polluted sites, failing 79 percent of the time.
“This is particularly problematic because many of these rivers run through communities and carry unacceptable levels of fecal contamination, posing a risk to human health,” said Linderoth. “People deserve to be able to wade in their local waters without worrying about getting sick.”
Embayments (47 percent) and shoreline sites (29 percent) still passed more than half the time, though both failure rates were up from 2022.
Greenwich Cove in Greenwich, CT, was the only location without a failing sample in 2023.
Nine New York locations failed 100 percent of the time: four in the Village of Mamaroneck (Mamaroneck Harbor East Basin, Beaver Swamp Brook at Boston Post Road, Beaver Swamp Brook at Rye Neck High School, Mamaroneck River at Station Park Road), three in Mount Vernon (Glover Field, an outfall at Farrell and Beechwood, upstream of Farrell and Beechwood), and one each in Rye (Blind Brook at Rye Nature Center) and Saddle Rock (Udalls Mill Pond).
For a closer look at the process of collecting and analyzing water samples for our Bacteria Monitoring Program, please see our recent blog post, “Journey of a Water Sample.”