Nassau County S.E.P.T.I.C. Replacement Program

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.

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

Nassau County has initiated a septic system replacement program for residents and small businesses - 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 of 50% of the costs, up to $10,000, 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 website at


Orenco Advantex AX20-RT


Orenco’s AdvanTex AX-RT is a completely pre-packaged, “plug & play” AX20 wastewater treatment system. All interior components are assembled and adjusted at the factory, so customers save on installation costs. There are fewer working parts, so customers save on equipment costs. And the RT can be shallowly buried, so customers save on excavation costs.



Norweco Singulair TNT 2.0


Manufactured on Long Island by Roman Stone Systems and achieves treatment by  gravity flow through a single,  three compartment tank.  Incoming wastewater enters the pretreatment chamber for removal of easily separated solids and begins the breakdown of the solids and organic particles.  Ammonification also occurs in this primary septic compartment. Wastewater then flows by gravity into the aeration chamber via a submerged transfer port. Air is introduced into the tank by an air pump and provides oxygen for the aerobic bacteria, mixes the wastewater, and extends the retention period.  Nitrification occurs in this chamber.  The wastewater then passes from the aeration chamber into the settling chamber.  A recirculation pump located in the settling chamber transfers nitrified liquid and settled activated sludge from the bottom of the settling chamber to the pretreatment chamber. The nitrates from the settling chamber and nutrients from the influent are mixed, and the denitrification process occurs under this anoxic condition, treated wastewater then flows by gravity through a filter to the soil treatment and dispersal area. 


SeptiTech STAAR


​The SeptiTech STARR™ biological trickling filter systems are designed to treat wastewater with minimal operator oversight while delivering consistently high quality treatment even during peak flows, low flows or intermittent flows.



Norweco Hydrokinetic


The Hydro-Kinetic system uses the extended aeration and attached growth processes to treat wastewater, and features innovative nitrification-denitrification technology. Achieved unmatched effluent results of 2.0 mg/L CBOD (Carbonaceous Biochemical Oxygen Demand), 2.0 mg/L TSS (Total Suspended Solids) and 7.9 mg/L TN (Total Nitrogen).


Hydro-Action AN Series


​The Hydro-Action system outperforms traditional septic tanks in prolonging drain field life, meeting environmental requirements, and handling issues like poor soil or high groundwater. Before wastewater enters the ATU, it runs through the pretreatment or septic tank. Pretreating reduces the amount of solids and other materials that can get into the system. The system’s flexibility allows the ATU to be added to an existing septic tank or used with the Hydro-Action system alone.


Fuji Clean CEN Series


​The CEN5 is Fuji Clean USA's most compact system, which can comfortably treat up to 4 bedrooms of straight wastewater. No preceding septic tank is necessary and not required (unless dictated by state or local regulations). A very small footprint (7'1" x 3'8") and weight of just under 400 pounds makes this system highly maneuverable and adaptable to the very tightest and most difficult-to-access sites. Designed to accommodate variable flows and shock loadings, this low power draw (54w) low maintenance compact system is a natural choice for a single family home.



I/A Septic System Installation

Long Island Clean-Water 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.


Follow us keep up with the S.E.P.T.I.C Replacement Program!