SOURCE:
https://www.massapequapost.com/articles/long-islands-fragile-drinking-water-system/
February 5, 2026 By JORDAN VALLONE, WILL SHEELINE & ABIGAIL GRIECO
Experts explain what lies beneath the surface, and detail the threats to our crucial aquifers
Long Island’s drinking water supply is solely dependent on aquifers. Sarah Meyland, a retired professor at the New York Institute of Technology, spoke about the impacts of chronic water depletion on the region’s water supply.
On Long Island, we’re not talking enough about water.
From the drops coming out of our taps to the waves breaking along both shores, myriad water-related issues have the potential to impact Long Islanders’ day-to-day lives.
The water system is not a single pipeline or policy, but a web of underground aquifers, aging infrastructure, coastal ecosystems — and policymakers — that together determine who has access to clean, affordable water — and who faces the greatest risk when that system begins to fail.
This series will break down how Long Island’s water system works, from aquifers to coastal bays, and clarify how policy, infrastructure and governance shape access to clean, affordable water. It will also examine the environmental pressures facing that system, from contamination and climate change to the health of bays, fisheries and drinking water supplies.
Through global reports that demonstrate the rapid growth of freshwater use over the past century, and interviews with environmental experts and regional advocates who connect these issues locally, this first installment examines what lies beneath the surface: the water we drink, and how contamination and access may disproportionately affect certain communities.
The sole source beneath Long Island
In order to understand Long Island’s relationship with drinking water, it’s essential to understand where the water comes from. The island relies on aquifers, underground layers of sand, gravel and clay that store billions of gallons of water accumulated over tens of millions of years. More specifically, Long Island relies on three: the Upper Glacial, the Magothy and the Lloyd (as well as a fourth, significantly smaller one, the Jameco).
These aquifers together are designated a single-source aquifer system by the Environmental Protection Agency, which means that “your groundwater supply is provided by an aquifer that serves at least 50 percent of your water needs,” according to Sarah Meyland, a former professor at New York Institute of Technology.
Meyland explained that both Nassau and Suffolk counties rely on this single aquifer system for 100 percent of our freshwater, whether it comes from a tap, shower or sprinkler. While this has meant that Long Islanders have had access to clean, easily accessed drinking water for decades, the aquifers, particularly in Nassau County, have one major downside.
“This aquifer needs to be particularly well protected, because if you damage it, or if you ruin it, you don’t have any other source of water,” Meyland said. “And that’s exactly the situation Long Island is in. We don’t have a secondary backup source of water.”
Since the federal government began measuring water usage in Long Island’s aquifers in 1900, roughly 5 percent of drinkable water has been consumed or lost due to salinization, the process by which freshwater is turned into saltwater. It occurs in aquifers due to overpumping, as water is taken out faster than it is replaced, causing saltwater from the Long Island Sound and the ocean to fill in the missing volume.
The vast majority of the used water is consumed by private sprinklers and irrigation systems, many of which are automated to water yards and home gardens. According to Meyland, Long Island has the highest per-capita water use of any community from New York to North Carolina, and the vast majority of that use occurs from spring through fall, when sprinklers turn on and swimming pools fill up.
While a 5 percent loss may seem inconsequential, the real problem is there’s no way to efficiently and cheaply replenish that loss. And the damage is not evenly distributed: The vast majority of the loss takes place in Brooklyn, Queens and Nassau, which have not effectively stewarded their portions of the aquifers.
Suffolk, which has the lowest population density of the four counties, has proactively monitored and managed its water intake and outflow for years, leaving its portion of the aquifers “a system in balance,” as Meyland described it.
She pointed out that Brooklyn’s portion of the aquifer system is already nonfunctional, Queens is barely better, and both now get their water from the New York City water system, which pumps freshwater in from upstate. Nassau is well on its way to following them; the difference is there is no municipal entity to bail Nassau out.
There is no known way to create new water, or to speed up the natural replenishment process. Desalination plants, which remove salt from water, are becoming more common globally, but they are expensive projects, according to Meyland.
“It’s like a bank account,” Meyland said. “The water, the money coming in, needs to be at least equal to the money going out.”
Water bankruptcy
The issues impacting drinking water supply are not unique to Long Island. According to a report released by the United Nations University last month, the world is entering an “era of global water bankruptcy” — a new, formal definition of a reality for billions of people. The report called for a “fundamental reset” of the global water agenda, as irreversible damage pushes sources of fresh drinking water beyond recovery.
“This report tells an uncomfortable truth: Many regions are living beyond their hydrological means, and many critical water systems are already bankrupt,” said the report’s lead author, Kaveh Madani, the director of the UN University’s Institute for Water, Environment and Health.
Numbers published by Our World In Data, a nonprofit publication that uses data to explain global issues like poverty, disease and climate change, showed that as of 2021, the United States withdraws the third-highest amount of freshwater from underground globally, roughly 444.4 billion cubic meters per year.
A key conclusion from the university’s report put the crisis in simple terms: “The world is already in the state of ‘water bankruptcy.’” In many basins and aquifers, long-term overuse and degradation, the report says, means that “hydrological and ecological baselines cannot realistically be restored.”
What areas are more affected?
If Long Island continues on the same path of aquifer depletion without any intervention from state authorities, such as the Department of Environmental Conservation, Meyland said, Nassau County will suffer more than Suffolk within the next 50 years.
“It’s about a third of the size of Suffolk with roughly the same number of people,” she said. “The Town of Brookhaven
is the same size as the county of Nassau. So Nassau County will continue to experience saltwater intrusions. That’s going to put pressure on virtually all of the water suppliers along the north and south shore.”
Meyland singled out Long Beach as an area that would likely lose its entire local water supply because of saltwater intrusion to the Lloyd Aquifer, the only aquifer the city draws from.
“They will have already been forced to look for other sources of water, whether they make arrangements from New York City, or they make arrangements and buy water from some of their neighboring water suppliers,” Meyland explained. “I’m sure there will be a lot of pressure to desalinate water, but that will be very expensive.”
On the North Shore of Nassau County, she said, areas of the Great Neck and Manhasset peninsula, including Sands Point, are at risk of losing their supplies of water, also due to salinity. And their options are limited, she added, because some of these communities are already piping water from other parts of Long Island.
Water suppliers are aware of the risk the future holds, Meyland said, but it is unfair to put the burden on them to fix the situation. “They are not at fault for what is happening to the water supply for coastal communities,” she said.
And water supplies are not only depleting on Long Island, but they are also contaminated.
The Environmental Working Group affiliated with Citizens Campaign for the Environment, a leading nonprofit organization dedicated to advocating for stronger environmental policies in New York and Connecticut, released a report in 2025 showing that a least 189 New York water systems — primarily serving residents of Long Island — detected high levels of toxic so-called “forever chemicals,” or PFAS, in tap water.
The report showed that 702,000 residents in Nassau County and 122,200 residents of Suffolk have elevated levels of PFAS in their water supplies. Some particularly vulnerable communities include those serviced by the Lynbrook-based Liberty Utilities, the Water Authority of Western Nassau and the Hempstead Town Water District.
What can be done?
According to Adrienne Esposito, executive director of Citizens Campaign for the Environment, geography and land use play a major role in why some Long Island communities experience more severe water quality issues than others.
“The biggest driver for water quality in the marine environment is land activity,” Esposito said, noting that polluted stormwater runoff, fertilizer use and marine debris all flow from developed areas into surrounding bays and waterways.
Highly populated and heavily developed regions — particularly along the South Shore — generate greater amounts of runoff, which carries excess nitrogen from lawn fertilizers, bacteria and debris into nearby bays. That nitrogen fuels algae growth, which depletes oxygen levels and can lead to fish kills and damage to shellfish populations.
Aging infrastructure in some coastal communities continues to pose challenges. Esposito pointed to the Long Beach’s sewage treatment plant, which discharges roughly 5 million gallons of wastewater per day into Nassau County’s Western Bays. While the wastewater is treated, Esposito said the facility is old and in need of major repairs.
The Western Bays have been among the most degraded areas, in part due to decades of treated sewage discharges and runoff from surrounding communities. Marine debris, including plastic bottles, cigarette butts and food packaging, often originates farther inland, and makes its way through tributaries before washing into coastal waters, Esposito said.
On the North Shore, in areas that still rely on septic systems, groundwater contamination presents another challenge, as pollutants can leach directly into aquifers and nearby waterways.
Esposito pointed to several major policy changes that have reshaped how New York addresses water contamination, particularly by emerging chemicals like PFAS and 1,4-dioxane.
She noted that the state now has some of the nation’s strongest drinking water standards for these chemicals — standards that are fully implemented across Long Island’s public water systems, the result of years of advocacy and scientific review.
In addition to regulating water systems themselves, Esposito highlighted a first-of-its-kind state law, passed in 2019, that limited the amount of 1,4-dioxane allowed in common household and personal care products. The law was phased in over several years and was fully implemented in 2023, reducing the amount of chemicals entering wastewater systems in the first place.
Esposito also emphasized the importance of preventing pollution at its source, rather than relying on expensive treatment systems after contamination occurs. Citizens Campaign has spent several years advocating for legislation aimed at reducing packaging waste, a significant contributor to marine debris found in Long Island’s bays and waterways.
One of the most significant steps underway is the long-awaited redirection of treated sewage from the South Shore Water Reclamation Facility, in Bay Park, away from the Western Bays and into the Cedar Creek ocean outfall pipe — a nearly $600 million project more than a decade in the making. The change is expected to dramatically improve water quality in the Western Bays once the Bay Park Conveyance Project is completed.
At the local and state level, municipalities are also tapping into grant programs designed to reduce stormwater pollution. These initiatives fund upgrades to stormwater systems, filtration devices that remove nitrogen and bacteria before runoff reaches waterways. Environmental organizations, including Citizens Campaign, Operation SPLASH and the Nature Conservancy have played a key role in advocating for these measures through long-term collaboration and public pressure.
Looking ahead, Citizens Campaign plans to launch a new marine debris prevention campaign this spring, focused on public education and outreach, emphasizing that litter discarded anywhere on Long Island can ultimately end up in coastal waters. The organization is also continuing its push in Albany for legislation aimed at reducing packaging waste and monitoring contaminants entering waterways through wastewater systems.
Residents can make a difference, Esposito said, by limiting fertilizer use, properly disposing of trash and supporting redevelopment over construction on green spaces.
“We encourage people to get up, show up and speak up,” she said. “If you want to protect our waters and public health, sometimes you have to speak out.”
