The site of a sewer project in Patchogue in 2023. Suffolk County...

The site of a sewer project in Patchogue in 2023. Suffolk County Executive Edward Romaine is stressing that all new sewer projects would include mechanisms to reuse treated water to help restore the aquifers. Credit: John Roca

As recent studies have cited saltwater intrusion in local aquifers, Suffolk County Executive Edward Romaine is stressing that all new sewer projects would include mechanisms to reuse treated water to help restore the aquifers.

The county is formulating plans to expand sewer systems because of new funding from a recently approved clean-water referendum. 

"All the sewers we will build will be tertiary in nature and will recharge," Romaine said in an interview. "We’re not as stupid as they were years ago where all they did is 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 direct treated water to the ocean and bays is leading to salt-water intrusion in the aquifers, impacting Long Island’s only source of clean water.

A 2024 federal report found that widespread pumping from aquifers under Long Island without equivalent recharging is increasing salt-water intrusion in parts of Nassau County. 

"The aquifer system underlying western Long Island has been under stress from pumping of public, irrigation (golf course), and industrial supply wells," the U.S. Geological Survey said in its report. "Saltwater intrusion has occurred from surrounding embankments due to pumping."

The result, according to USGS: "Most of Kings and Queens Counties are intruded with saltwater in both the upper glacial-Jameco-Magothy and Lloyd-North Shore aquifers systems. Saltwater 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 major wedge of saltwater intrusion in the upper glacial-Jameco-Magothy aquifer in southwestern Nassau County appears to be increasing."

A spokesman for Nassau County didn’t immediately respond to a request for comment.

The findings, which in 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 pounding the drum about the importance of recharging the aquifer for a decade. In public hearings, private meetings with political leaders and in 19-page report on the topic, Mark Romaine has pointed to decades-old predictions that a recent study by the federal government has proven true. (Mark Romaine and Ed Romaine are not related.) 

As Mark Romaine’s paper, "Groundwater: The Cornerstone of Environmental Equilibrium," noted, U.S. 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 found.

In one area of Nassau County’s South Shore where sewers were installed more than 60 years ago, average groundwater levels consistently declined over a 60-year period, from a maximum of 70 feet prior to the 1970s to less than 60 feet since then, according to cited data.

But it’s not just drinking water supplies that are impacted when overpumping and under-recharging occurs. The equilibrium of streams, creeks and rivers are also affected, and their natural flow into bays and estuaries is thrown off balance. Romaine's paper cited a 1978 study by the U.S. Environmental Protection Agency noting that groundwater aquifers make up 95% of the fresh water that flows into local streams, and 100% of "subsurface flow 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 sewers that carry wastewater to a treatment plant and thence to the ocean, millions of gallons a day of potential groundwater recharge will be lost to Long Island's hydrologic system."

Previous Suffolk officials and their allies have criticized Mark Romaine's theories in the lead-up to the referendum on water quality, which was overwhelmingly passed by Suffolk residents in November. Documents he obtained under the Freedom of Information Law show top former Suffolk officials discussing ways to attack his findings and to instead focus on increased nitrogen levels in waterways.

The former officials noted that sewering accounts for only 26% of wastewater treatment in Suffolk, and that much of the treated water from them "goes to surface waters that discharge into the Great South Bay." But Romaine said it’s important how the water gets to the bay — and that it's best to do it through inland recharge. 

In a July 23, 2023 paper in response to Romaine's, Christopher Gobler, a professor at Stony Brook University's School of Atmospheric Sciences, said Romaine's findings, while "on point for New York City" and to a lesser degree Nassau County, have "almost no relevance for Suffolk County." 

Gobler wrote that Suffolk has considerably lower population density's than both the city and Nassau, and studies have shown "an enormous excess of groundwater" for Suffolk" and "no risk of aquifer depletion, even at full buildout of the county." 

Worse, Gobler wrote, "Increasing the delivery of water to ground may also create a public health threat," if the water isn't treated to remove elevated levels of nitrogen, which is said is crucial to restoring local waterways. 

Romaine takes exception to the widely reported findings by established scientists and biologists that nitrogen is the primary factor in the reduction of water quality across Long Island. Calling nitrogen a "phantom menace," he notes the natural occurrence of nitrogen, but said "unmitigated changes in land and water use disturb this cycle."

Sending treated sewer water to distant bays and oceans upsets the delicate balance of life in the waterways, Romaine said, altering the "essential freshwater budget." He blamed this upset for the sharp decline of the clam population in the Great South Bay, among other things, calling the bivalves the "canary in the coal mine." 

An avid fisherman and parent, Romaine said his main concern is the legacy his generation leaves 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."

Suffolk Police Officer David Mascarella is back on the job after causing a 2020 crash that severely injured Riordan Cavooris, then 2. NewsdayTV's Andrew Ehinger and Newsday investigative reporter Paul LaRocco have the story. Credit: Newsday/Kendall Rodriguez; Jeffrey Basinger, Ed Quinn, Barry Sloan; File Footage; Photo Credit: Joseph C. Sperber; Patrick McMullan via Getty Image; SCPD; Stony Brook University Hospital

'It's disappointing and it's unfortunate' Suffolk Police Officer David Mascarella is back on the job after causing a 2020 crash that severely injured Riordan Cavooris, then 2. NewsdayTV's Andrew Ehinger and Newsday investigative reporter Paul LaRocco have the story.

Suffolk Police Officer David Mascarella is back on the job after causing a 2020 crash that severely injured Riordan Cavooris, then 2. NewsdayTV's Andrew Ehinger and Newsday investigative reporter Paul LaRocco have the story. Credit: Newsday/Kendall Rodriguez; Jeffrey Basinger, Ed Quinn, Barry Sloan; File Footage; Photo Credit: Joseph C. Sperber; Patrick McMullan via Getty Image; SCPD; Stony Brook University Hospital

'It's disappointing and it's unfortunate' Suffolk Police Officer David Mascarella is back on the job after causing a 2020 crash that severely injured Riordan Cavooris, then 2. NewsdayTV's Andrew Ehinger and Newsday investigative reporter Paul LaRocco have the story.