Protecting Long Island’s Most Vital Resource: Clean Water Symposium Focuses on Long Island’s Future

Long Island is surrounded by water, yet protecting clean water has become one of the region's defining challenges.

Hard clam populations that once supported one of New York's most productive fisheries have declined by nearly 99 percent. Harmful algal blooms now close beaches and discolor ponds. More recently, PFAS "forever chemicals" have emerged in groundwater supplies across the region.

"I've watched in my lifetime the demise of the Peconic Bay scallop fishery, harmful algal blooms increase, and now in the second legislative district we have not one but two situations with emerging contaminants, PFAS, among others, both affecting our surface waters and our groundwaters," said Suffolk County Legislator Ann Welker.

Those challenges and others brought scientists, policymakers, water suppliers, environmental professionals and community members to Stony Brook University's Charles B. Wang Center on June 12 for a day-long 2026 Clean Water Symposium, hosted by the New York State Center for Clean Water Technology (CCWT). The event featured Yale University engineering professor Jaehong Kim, who delivered the keynote address on translating water treatment innovations from the laboratory to real-world applications.

Speakers discussed water quality issues facing Long Island and New York State, from nitrogen pollution linked to septic systems and phosphorus-driven harmful algal blooms to the growing challenge of removing PFAS from drinking water.

"The critically important work of the New York State Center for Clean Water Technology is cutting edge, vital to our region and to our world," Welker said. "Research today is more important than ever."

That research is the focus of CCWT, which brings together scientists from across Stony Brook University to address some of the state's most urgent water challenges.

CCWT Director Christopher Gobler, SUNY Distinguished Professor in the School of Marine and Atmospheric Sciences (SoMAS), welcomed the crowd that filled the Charles B. Wang Center auditorium and overflowed into two nearby lecture halls where the event was livestreamed.

He described the center's mission as bringing together researchers across disciplines to develop solutions for some of New York's water quality issues. "Our mission is to harness science to engineer clean water solutions for the protection of public health and the environment, while promoting economic development in New York and beyond," Gobler said.

That mission has become increasingly important as Long Island continues to struggle with the environmental consequences of decades of growth. As Suffolk County transformed from a rural county into a suburban one, nitrogen concentrations in groundwater steadily increased. The impacts can now be seen throughout the region, from declining fisheries and shrinking salt marshes to harmful algal blooms and low-oxygen zones that threaten aquatic ecosystems.

"99 percent. Sometimes numbers are used as hyperbole, but that is how much the landings of hard clams had declined," said Gobler. "There was a time where people got more bay scallops out of the Peconic Estuary than any other estuarine system in the country, and that's down 99 percent."

Researchers now have a clearer understanding of where much of that pollution originates. "The studies are in, the studies have been done, and we know that with 70 percent of the county unsewered, the biggest source of nitrogen from land to sea is onsite septic systems," Gobler said. "We're ultra-focused on how we deal with these old antiquated systems that are literally discharging right into our drinking water source."

Understanding the sources of pollution is only part of the challenge; developing technologies that can effectively remove contaminants and deploying them at a scale large enough to protect public water supplies is often the more difficult task.

That challenge was the focus of keynote speaker Jaehong Kim, the Henry P. Becton Sr. Professor of Engineering at Yale University, who discussed the complexities of translating promising water treatment technologies from the laboratory into real-world applications.

"As we're thinking about translation to real-world application, what becomes more important is how long it lasts and at what cost," Kim said. He highlighted catalytic water treatment technologies designed to destroy contaminants rather than simply capture them. "Advanced oxidation is somewhat unique in that it is relying on producing reactive oxygen species, the radicals, to destroy these pollutants to the benign end-product," Kim said.

Researchers also presented advances in nitrogen-removing biofilters, phosphorus-removal technologies and new approaches to addressing PFAS contamination.

Residents are becoming increasingly invested in those solutions. State Senator Monica Martinez pointed to the Suffolk County Water Restoration Act, approved by voters in 2024, as evidence that residents recognize what is at stake. "What that shows you is that Long Islanders care about their water quality," Martinez said. "They care about it enough to go to the polls and vote for it."

Martinez noted that Long Island's dependence on a sole-source aquifer makes protecting water resources especially important. "Having the sole aquifer here on Long Island for our drinking water is something that we need to really pay attention to and take care of. Take care of it for right now, but also take care of it for our children who are coming right behind us," she said.

While nitrogen pollution has long dominated conversations about Long Island water quality, researchers are increasingly focused on another growing threat: phosphorus. In freshwater lakes and ponds, excess phosphorus can fuel harmful cyanobacterial blooms that turn waterways bright green, threaten wildlife and in some cases produce toxins that pose risks to human and animal health.

Xinwei Mao, a research scientist at CCWT, described the research being conducted at CCWT to develop ways to prevent phosphorus from reaching waterways.

"Our work is organized around these three complementary areas, which include field monitoring, commercial products validation, and novel technology development," Mao said. "So basically, take all these activities that allow us to move from understanding the phosphorus problem to really implementing the solutions."

If nitrogen and phosphorus represent longstanding environmental challenges, PFAS contamination presents a newer and rapidly evolving concern.

Often referred to as "forever chemicals," PFAS are used in a wide range of consumer and industrial products and can persist in the environment for decades. Their widespread presence in groundwater and drinking water supplies has made them a growing focus for researchers, regulators and water suppliers alike.

"When we first started at the center, the first compound we worked on was something called 1,4-dioxane," Gobler said. "But another issue that we've been working on more recently is these forever chemicals. They're very, very serious PFAS chemicals."

Research scientist Lokesh Padhye, associate professor in the Department of Civil Engineering at Stony Brook, explained why PFAS has become such a difficult challenge. "The stable carbon fluorine bond in PFAS presents a challenge, so it's very difficult to get rid of this contamination," Padhye said. "Many of these technologies to treat PFAS are expensive, they are not sustainable and certainly not green."

CCWT researcher Kevin Shaffer discussed PFAS exposure outside of water. "There are a lot of ways that we can be exposed to PFAS," Shaffer said. "That's why monitoring is so important."

While researchers work to better understand and remove PFAS contamination, water suppliers are already investing heavily in treatment technologies to meet increasingly stringent drinking water standards. "We moved right away to try to meet the new proposed standard," said Tim Kilcommons of the Suffolk County Water Authority. "We have operational restraints that already have us in full compliance years ahead of the EPA suggested deadline."

Assemblyman Steve Englebright, a longtime advocate for environmental protection, said the symposium reflects the type of collaboration needed to confront complex water challenges.

"Water is the first limiting factor for our ability to live on Long Island at all, so these partnerships really matter," Englebright said.

- Beth Squire