Nassau County SEPTIC Program Logo

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 us at  or  (516) 364-5861


OR visit our page on the Nassau County website at

Why Nitrogen Reducing Systems?


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 fish kills. A conventional onsite septic system was never designed to remove nitrogen. The average residential septic system discharges approximately 40 pounds of nitrogen into the ground per year.

How do they work? 

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.

Nassau County Insignia
Additional Resources

Check for Sewer Service - Review your tax assesment to determine if you are in a proposed sewer district


Application Roadmap - Outlines step by step instructions for applicants to follow to apply for the program.  


I/A Septic Systems Accepted for the Program - Browse the Innovative and Alternative Septic Systems available for applicants of the SEPITC Replacement Program, here you will find links to the manufacturer webpage and contact information. 


Frequently Asked Questions - Questions Regarding S.E.P.T.I.C. Grant Program, Clean Water (nitrogen-reducing) Septic Systems and the S.E.P.T.I.C Grant Program Application process.


Industry Resources - For Installers or Designers interested in Participating in the program. Here you will find guidance memos and resources that outline the program rules and guidelines. 

Applicants Currently Enrolled

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Applicants Currently Enrolled in the SEPTIC Program
Applicants Currently Enrolled in the SEPTIC Program North Shore

NCSWCD goes to Washington! 

The Nassau County Soil & Water Conservation District, along with various environmental organizations, travelled to Washington DC to meet with state representatives and discuss many topics important to quality of life on Long Island, including continued clean up of the Long Island Sound, the classification of Plum Island Preserve, and the tax status of Nassau County S.E.P.T.I.C. Replacement Program grant awards.

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.

NCSWCD Staff at Clean Water Vendor Day

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. 

Nassau SWCD - Septic Smart Week

Photos from Septic System Installations

Nassau SEPTIC Program Installation 2
Nassau SEPTIC Program Installation 3
Nassau SWCD Attending first septic installation with the SEPTIC Program

NCSWCD attending the first clean water septic instillation 

Nassau SEPTIC Program Installation

Site tours of successfully installed nitrogen-reducing systems!

Nassau SWCD - Septic Installer touring system
Nassau SWCD - Septic Installer touring system

Maintaining 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's and Don'ts for your I/A Septic System
Do's and Don'ts for your I/A Septic System - Flushable Wipes

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.

Chemical additives marked to unclog drains, break up oil and greese may also contain acids, solvents, hydrogen peroxide or strong caustic agents. Overtime, excessive use of antibacterial products like wipes can kill off the beneficial bacteria that helps the system operate. 


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