Nassau County has initiated a septic system replacement program for residents, small businesses and non profits - Septic Environmental Program to Improve Cleanliness (SEPTIC). The SEPTIC program will provide grant funding to eligible recipients to replace a conventional or failing septic system with an innovative and alternative onsite wastewater treatment system. Nassau County is offering grants up to $20,000, for homeowners or small businesses to install state-of-the-art nitrogen reducing septic systems.  

For more information, please contact SepticReplace@nassaucountyny.gov or (516) 364-5861.


OR visit our page on the Nassau County website at www.nassaucountyny.gov/septicreplace

How do they work?

Nitrogen pollution from cesspools and septic systems has been identified as the largest single cause of degraded water quality contributing to beach closures, restrictions on shellfishing, toxic algae blooms, and massive fish kills. A conventional onsite septic system was never designed to remove nitrogen. The average residential septic system discharges approximately 40 pounds of nitrogen per year.


All six of the Provisionally Approved Technologies in Nassau County rely on biological processes to treat wastewater and remove nitrogen. These systems use various methods to provide aerobic bacteria to convert organic nitrogen to nitrite and nitrate and then use an anaerobic (without oxygen) environment to denitrify by stripping the oxygen molecule off of the nitrate nitrogen, resulting in the release of gaseous nitrogen into our atmosphere. The nitrogen cycle is one of Earth’s most important biological process, second to only photosynthesis.

I/A Systems Approved for the Program

I/A Septic System Installation

Nassau S.E.P.T.I.C. Grant Program - Clean Water Septic Vendor Day

The Nassau County Soil and Water Conservation District participated in the Long Island Clean-Water Vendor Day! This event brought awareness to the community about outdated, failing, conventional septic systems. These outdated septic systems are the number one cause of nitrogen pollution in Long Island, leading to harmful algal blooms, thick mats of seaweed, fish kills and the overall decline of the shellfish industry. Switching to new innovative and alternative septic systems can remove more than 70% of the nitrogen pollution from our wastewater!

Vendor Day displayed Nassau County approved innovative and alternative septic system designs. Attendees had the opportunity to ask questions to expert distributors and representatives from the Nassau S.E.P.T.I.C. program.