A comprehensive study to develop a management plan to restore Fort Pond is warranted, those participating in a Nov. 12 webinar hosted by Concerned Citizens of Montauk were told.
Christopher Gobler, who spoke in the webinar and answered questions, leads an effort to monitor for the presence of harmful algal blooms at Fort Pond and Big Reed Pond, also in Montauk. C.C.O.M. joined with the Gobler Lab at Stony Brook Southampton's School of Marine and Atmospheric Sciences two years ago, after toxic cyanobacteria, or blue-green algae, appeared in Fort Pond, as it has in a number of water bodies on the South Fork and in every state in the nation.
In 2015, dogs were sickened and nearly died after swimming in Fort Pond, and the swimming portion of the MightyMan Montauk triathlon was canceled in 2016 and 2017 owing to dense blooms of cyanobacteria. The blue-green algae has been detected in the pond in subsequent summers.
The comprehensive study Dr. Gobler proposes would identify the exact sources of nutrients and bacteria in the pond and expand the ongoing program of water quality monitoring and analysis, Laura Tooman, C.C.O.M.'s president, said on Monday. The group is prioritizing elements of the proposed study and will seek funding to accomplish it, she said.
All of Long Island is a watershed, Dr. Gobler said. "We live on an island, and nowhere is this term more important than an island where the only source of drinking water is the groundwater. Therefore, the connections between land and groundwater and surface waters and drinking water are all critical." Activity on land influences the quality of groundwater, and "our groundwater is our drinking water. Whatever we do not extract for drinking water discharges into surface waters."
Suffolk County's expanding population, which has approximately doubled since 1960, has brought a dramatic rise in the nitrogen concentration in groundwater, according to Dr. Gobler's presentation, with multiple studies concluding that wastewater, mostly emanating from septic systems and cesspools, is the biggest source. An abundance of nutrients, along with high water temperatures, promote harmful algal blooms.
Fort Pond's ecological health, and the response to its degradation, could track that of Georgica Pond in East Hampton and Wainscott, Dr. Gobler suggested. A dog died after swimming in that water body in 2012, leading to the formation of the Friends of Georgica Pond Foundation, a group of pondfront property owners who engaged Dr. Gobler to sample the water and develop mitigation strategies, and encourage the replacement of septic systems on properties within its watershed. Incidents and measurements of cyanobacteria have fallen sharply since 2016.
But there are critical knowledge gaps with respect to Fort Pond, Dr. Gobler said. These include the relative nitrogen and phosphorus concentrations, a potentially important data point; dissolved oxygen conditions; environmental factors that may trigger cyanobacteria blooms; the sources of nutrients and pathogenic bacteria in the pond, and the levels of nutrient reductions and remedial approaches required to mitigate blue-green algal blooms.
Ms. Tooman noted other remediation efforts underway that are expected to improve conditions in Fort Pond. Among these are the town's "very active land preservation program" through the purchase of parcels in the watershed with community preservation fund money and incentives and encouragement to upgrade septic systems, she said.
The New York State Department of Environmental Conservation recently approved C.C.O.M.'s planned floating wetlands project in the pond, which will see vegetation affixed to floating mats drawing nitrogen and phosphorus out of the water. The mats are then removed, the vegetation is sent for composting, and the process is repeated.
When the town board awarded C.C.O.M. $25,211 to fund the pilot program last year, an official in the Natural Resources Department estimated nutrient reduction in one year of almost 28 pounds of nitrogen and around 15 pounds of phosphorus. That would not make "a large-scale improvement," Ms. Tooman said during the webinar, "but is more a testing program to see how much nutrient uptake can happen."
She also spoke of the long-planned wastewater management district for downtown Montauk, which the town board advanced last Thursday by voting to hire a consulting and engineering firm to create a map and plan.