Long Island’s communities may differ in size, landscape, and character, but they all share something essential in common: a connection to the surface and groundwater resources of the island.   

Nitrogen pollution is one of the most significant threats to the health of Long Island’s waters. Residential wastewater from outdated septic systems, excess fertilizer use, and stormwater runoff all contribute nitrogen to groundwater and surface waters. Because Long Island’s sandy, porous soils drain quickly, excess nitrogen can move quickly through the ground, contaminating the groundwater that supplies the region’s drinking water. When excess nitrogen reaches the bays and harbors it can fuel harmful algal blooms and oxygen-depleted “dead zones” leading to fish kills. 

From Understanding to Action 

Addressing this challenge requires action at every level and it starts in our communities. The Nitrogen Smart Communities (NSC) program is encouraging municipalities across Long Island to take a closer look at where nitrogen comes from in their communities and more importantly, what they can do about it. Participating municipalities engage local stakeholders, identify priority sources of nitrogen, and develop actions designed to reduce, prevent, or eliminate nitrogen pollution. Through a five-step process, communities move from community outreach and education to putting effective reduction strategies into practice, earning tiered levels of certification as they progress.  

The program provides each community with tools, information, and hands-on technical support to identify the actions that make the most sense where they live, contributing to improved water quality both locally and across Long Island.  

The Pilot Nitrogen Smart Communities 

With funding provided by the EPA Long Island Sound Partnership, the program began with two pilot communities: the Town of Smithtown in Suffolk County and the Town of North Hempstead in Nassau County. Both municipalities have since advanced through step 3 of the framework by completing extensive nitrogen source inventories. This milestone reflects their commitment to identifying local sources of excess nitrogen and lays the groundwork for meaningful reduction strategies. As the program's pioneers, Smithtown and North Hempstead have successfully established a path for other Long Island communities to follow. 

North Hempstead Supervisor, Jennifer DeSena states that “Protecting our environment isn’t something we can leave to someone else or to another generation. It must start right here at home, and it has to be now. North Hempstead is proud to participate in the Nitrogen Smart Communities program and help protect our waterways, preserve our drinking water, and keep our community healthy.”  

Smithtown Supervisor Edward R. Wehrheim emphasizes that “Reaching Silver Status in the Nitrogen Smart Communities program is an important milestone for Smithtown and reflects the thoughtful work our team has put into understanding where nitrogen pollution originates within our community and how we can address it effectively. Protecting our groundwater, harbors and waterways requires more than a one-size-fits-all solution. It means identifying our specific sources, engaging the community, and using that information to guide practical, locally driven strategies. We are proud to have served as one of the pilot municipalities for this program.” 

Building on the pilot program, the initiative expanded in early 2026 to welcome four additional communities: City of Glen Cove, Town of East Hampton, Village of Poquott, and Village of Quogue. 

From coastal neighborhoods with aging septic systems to urban areas navigating heavy stormwater runoff, these communities capture the broad array of Long Island's water-quality concerns. The nitrogen reduction actions selected by each community will depend on its nitrogen sources and local needs. Potential strategies include educating residents about septic system replacement programs, reducing fertilizer use on municipal properties, improving wastewater infrastructure, installing green infrastructure to manage stormwater, labeling storm drains, protecting open space, and expanding marine pumpout services. Communities may combine public education and outreach, on the ground projects, and policy changes to create an approach suited to their priorities. 

A Shared Responsibility 

As more municipalities become Nitrogen Smart, individual local efforts can add up to meaningful regional progress. Each nitrogen source identified, community member involved, and reduction strategy implemented represents another step toward cleaner groundwater, healthier waterways, and more resilient coastal ecosystems. 

The Nitrogen Smart Communities program is built on the idea that protecting Long Island’s waters is a responsibility shared across the island, and progress happens one community at a time. 

For more information on the program please visit Nitrogen Smart Communities.