As recent studies have cited saltwater intrusion into local aquifers, Suffolk County Executive Edward Romaine stresses that any new sewer project would include mechanisms to reuse treated water to help restore the aquifers.
The county is drawing up plans to expand the sewer systems because of new funding from a recently approved clean water referendum.
“All the sewers we will build will be tertiary and will be recharged,” Romaine said in an interview. “We’re not as stupid as they were years ago where all they did was take that outfall pipe and send it out to the ocean or Long Island Sound.”
Studies have shown that sewer projects with outfall pipes that carry treated water to the ocean and bays lead to saltwater intrusion into aquifers, affecting Long Island’s only source of clean water.
A 2024 federal report found that widespread pumping from aquifers beneath Long Island without corresponding recharge is increasing saltwater intrusion in parts of Nassau County.
“The aquifer system underlying western Long Island has been under stress from the pumping of public, irrigation (golf course) and industrial supply wells,” the US Geological Survey said in its report. “Salt water intrusion has occurred from surrounding dikes due to pumping.”
The result, according to the USGS: “Most of Kings and Queens counties are intruded by saline water in both the upper glacial-Jameco-Magothy and Lloyd-North Shore aquifer systems. Saline water increased during the 20th century and continues to increase to the present in the Lloyd-North Shore aquifer system in Great Neck and Manhasset Neck in northern Nassau County.”
Worse, the USGS found, “a large wedge of saltwater intrusion in the upper glacial-Jameco-Magothy aquifer in southwestern Nassau County appears to be increasing.”
The results, which in the coming months will be supplemented by a review of similar research in Suffolk County, are no surprise to Mark Romaine, a Babylon investment adviser, trout fisherman and local historian, who has been beating the drum about the importance of recharging aquifers in a decade. In public hearings, private meetings with political leaders and in a 19-page report on the subject, Mark Romaine has pointed to decades-old predictions that a recent federal government study has shown to be true. (Mark Romaine and Ed Romaine are not related.)
As Mark Romaine’s paper, “Groundwater: The Cornerstone of Environmental Equilibrium,” noted, the US Geological Survey and other studies going back decades have predicted the problem. One was published as recently as June 2018. “In Nassau and Suffolk counties … pumping water for domestic supply has lowered the water table, reduced or eliminated the base flow of streams, and has caused saline groundwater to move inland,” the USGS noted.
In an area of Nassau County’s southern coast where sewers were installed more than 60 years ago, average groundwater levels dropped consistently over a 60-year period, from a maximum of 70 feet before the 1970s to less than 60 feet since then. according to quoted data.
But it is not just the drinking water supply that is affected when overpumping and undercharging occur. The balance of creeks, streams and rivers is also affected, and their natural flow to bays and estuaries is lost. Romaine’s paper quoted one 1978 study by the US Environmental Protection Agency notes that groundwater aquifers make up 95% of the fresh water that flows into local streams and 100% of “subsurface flows into bays.”
“Individual wastewater disposal systems, such as cesspools and septic tanks, return used water to the groundwater system; sewers do not,” the EPA study noted. “Therefore, if cesspools and septic tanks are replaced by drains that direct wastewater to a treatment plant and from there to the ocean, millions of gallons per day of potential groundwater recharge will be lost to Long Island’s hydrologic system.”
Former Suffolk officials and their allies have criticized Mark Romaine’s theories ahead of the water quality referendum, which was overwhelmingly approved by Suffolk residents in November. Documents obtained by him under the Freedom of Information Law show former Suffolk officials discussing ways to attack his findings and instead focus on increased nitrogen levels in waterways.
The former officials noted that sewage only accounts for 26% of sewage treatment in Suffolk, and that much of the treated water from them “goes into surface water that flows into the Great South Bay.” But Romaine said it’s important how the water gets to the bay — and that it’s best done through inland recharge.
In a July 23, 2023 article responding to Romaines, Christopher Gobler, a professor at Stony Brook University’s School of Atmospheric Sciences, said that Romaines’ findings, while “on point for New York City” and to a lesser extent Nassau County, have “almost no relevance to Suffolk County.”
Gobler wrote that Suffolk has significantly lower population density than both the city and Nassau, and studies have shown “a huge excess of groundwater” for Suffolk and “no risk of aquifer depletion, even with full expansion of the county.”
Worse, Gobler wrote, “Increasing the supply of water to the ground can also create a threat to public health,” if the water is not treated to remove elevated levels of nitrogen, which is said to be critical to restoring local waterways.
Romaine takes exception to the widely reported findings by established scientists and biologists that nitrogen is the primary factor in declining water quality across Long Island. Calling nitrogen a “phantom threat,” he notes the natural occurrence of nitrogen, but said “unimproved changes in land and water use disrupt this cycle.”
Sending treated sewage to distant bays and oceans upsets the delicate balance of life in the waterways, Romaine said, altering the “essential freshwater budget.” He blamed this outrage for the sharp decline in the clam population in the Great South Bay, among other things, calling the clams “the canary in the coal mine”.
An avid fisherman and parent, Romaine said his main concern is the legacy his generation leaves behind for the next.
Scientific knowledge and technological innovation, he wrote, “can identify and address the problem. Only political will … can determine what this generation will bequeath to the future.”
Mark Harrington, a Newsday reporter since 1999, covers energy, wineries, Indian affairs and fisheries.
