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 or (516) 364-5861.

OR visit our page on the Nassau County website at

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 five of the Provisionally Accepted 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 Accepted for the Program

Applicants Currently Enrolled

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How to Maintain your Septic System


Making sure your I/A system is properly maintained will save you time and money while also allowing the system to sufficiently reduce the harmful nitrogen from your wastewater.


Most of these tips and tricks found in our Do's and Dont's for your I/A Septic System flyer apply to conventional systems as well, so caring from this system is not too different from what you're used to.


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Do Not Flush "Flushable" Wipes


Maintaining your septic system starts with not flushing products that hurt your system. "Flushable" wipes and baby wipes can cause blockage inside your pipes or system.

Overtime, excessive use of antibacterial wipes can kill off the beneficial bacteria that helps the system operate.


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Septic Smart Week


The Nassau Count Soil & Water Conservation District hosted several events to celebrate the EPA's 10th Annual Septic Smart Week!


Vendor Exhibit at the Locust Valley Library showcasing the five manufacturers of approved nitrogen-reducing septic systems followed by a presentation covering the program and its goals. 

Site tours of successfully installed nitrogen reducing systems!

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 accepted 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.