Nassau County SEPTIC Program Logo
Septic Replacement 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

S.E.P.T.I.C. Program Overview


Nitrogen pollution from cesspools and septic systems has been identified as a leading cause of degraded surface water quality on Long Island, contributing to restrictions on shellfishing, toxic algae blooms, and massive fish kills. Approximately 40,000 residential properties on the North Shore of Nassau County are currently served by cesspools and septic systems. Reversing the degradation of water quality depends on the replacement of existing systems with new nitrogen-reducing technologies.


This need is addressed in Nassau County’s Nine Key Element Watershed Plan for Nitrogen, which advances efforts to restore and protect the water quality of the groundwater and embayments around Nassau County by recommending a variety of best management practices and actions, including the replacement of failing septic systems and cesspools with innovative alternative on-site treatment systems. Combined with the Long Island Nitrogen Action Plan (LINAP), the Nine Element Plan is part of the larger regional effort to coordinate nitrogen reduction efforts on the island.


In an effort to incentivize the use of these technologies and protect public and environmental health, Nassau County and New York State have created a septic system replacement program for eligible properties. The Septic Environmental Program to Improve Cleanliness (S.E.P.T.I.C.) provides grant funding of up to $20,000.00 to eligible homeowners, not-for-profits, and small businesses to replace conventional septic systems and cesspools with nitrogen-reducing innovative and alternative onsite wastewater treatment systems (IA OWTS).


Launched in May of 2021, the S.E.P.T.I.C. Program is administered by the Nassau County Soil and Water Conservation District (District) on behalf of Nassau County. The Program has been awarded over $8 million to fund approximately 400 upgrades to nitrogen-reducing technologies, of which 118 have been installed as of January 3, 2024.


Nassau’s S.E.P.T.I.C. Program – Qualifying Properties

  • Single and two-family homes, not-for-profit organizations, small businesses, and municipalities. 
  • Organizations with a sanitary design flow less than 1,000 gallons per day (GPD)
  • Replacement of an existing septic system or cesspool with a new nitrogen-reducing IA OWTS

  • Both design and construction of any replacement must have been approved by the local permitting authority. 
  • Must have no tax liens or active foreclosure actions.
  • Must have a valid certificate of occupancy (CO) or equivalent issued by the pertinent
  • city, town or village.
  • Must be served by an existing septic system or cesspool and not be connected to a public or private sewer or located within an existing or proposed sewer district.
  • If the property is located in an existing sewer district but is unable to connect due to site constraints documented by the Sewer District in question, the property may be eligible, provided the applicant meets all other eligibility requirements



Nassau County S.E.P.T.I.C. Program Funds are not considered taxable income as they provide a community health benefit. 

Nassau County Insignia

Additional Resources

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


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.


Homeowner Resources - For Homeowners and property owners signed up for the S.E.P.T.I.C. Program. 


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

Applicants Currently Enrolled in the SEPTIC Program North Shore

Photos from Septic System Installations