The preliminary results of a DNA study of possible sources of the contamination that has kept Crescent Beach closed to swimmers for almost 10 years may not have been as conclusive as was previously reported, according to one of the scientists who conducted the study. Jim Ferretti, an expert on bacterial contaminants, said that wet-weather samples, taken after significant rains, would likely offer more bacterial clues than the existing samples, which were taken in dry weather.
Ferretti, who keeps a stuffed excrement emoji named Smelldon in the Environmental Protection Agency lab that conducted the tests, was careful to note that “these bacteria change from hour to hour,” and added that a little rain could have a big impact. That’s why he was expecting to be back in Glen Cove in the coming weeks to take additional wet-weather samples.
It’s not impossible, he said, for a wet-weather sample to indicate human sources, even though the dry sample did not.
After another round of testing, Ferretti said, it would be helpful to determine the source animal. “If it’s geese,” he said, the question is, “how do you keep the geese away?” Different species require different interventions.
The single sample that showed extremely high levels of fecal coliform — a bacterium found in the excrement of warm-blooded animals — was taken from a storm drain off Jackson Lane, just west of the North Shore Day Camp tennis courts. According to Ferretti, who led the team at the EPA lab that undertook the study and who was on hand when the samples were collected, the Jackson Lane sample “was just trickling out of there . . . There wasn’t even enough flow to dip the [sample] bottle in it.”
Mayor Tim Tenke said that the day camp used to have several horses, which some locals had speculated were the source of the problem. But Tenke added that as of at least a few years ago, none of the properties in that area still had any horses.
All other samples besides the one from Jackson Lane were taken from a stream just west of Valley Road. They all showed far lower levels of the fecal contaminant. High levels of other coliforms, like E. coli and enterococcus, were detected in some samples, but, Ferretti said, general coliform levels are more important to regulate in drinking water than in bathing water, where fecal coliform plays a central role.
Last week, the Herald Gazette reported that the fecal coliform did not contain either of two human markers, meaning that the culprit was most likely a bird or other mammal. Ferretti said, however, that additional samples, taken after rainy weather, were needed to confirm that conclusion. He added that the lab planned to take more samples in the coming weeks.
Properties in the area had been the subject of previous tests and studies. They included a dye test to check for leaky plumbing — it found none — and fiber-optic camera tests to determine the source of outflow from pipes in the area that officials found suspect. Those tests were inconclusive, suggesting that the plumbing infrastructure of nearby homes wasn’t to blame.
The City of Glen Cove and the Nassau County Department of Public Works are working together to determine whether filters could temporarily solve the contamination problem at Crescent Beach. The county agreed in late July to spend $200,000 to explore the possibility of installing filters. But, Tenke said, “These filters can only treat so much water per hour. We’re at the stage right now where we’re trying to determine flow rates” to ensure that filters are installed in the optimal locations. To that end, the city will issue a request for proposals for firms to study the issue.