Verified as of September 16, 2026. We re-check these pages quarterly.
The approved routes
The state recognizes three: in-ground nitrogen-reducing biofilters, Florida-approved nitrogen-reducing aerobic treatment units certified to NSF 245, and approved nitrogen-reducing performance-based treatment systems. In practice, for a house, the real choice is the first two.
The aerobic treatment unit
A tank with air pumped through it. The blower keeps the bacteria aerobic, which is what strips the nitrogen. It works, it is well understood, and it is what most contractors will propose first.
What comes with it: a blower that runs continuously and uses power, an alarm that eventually goes off, a maintenance contract that Florida requires for the life of the system, and a periodic inspection at $350–$600 rather than the $175–$550 a conventional system costs to inspect. It still needs pumping like any other tank — the maintenance visit is not a pump-out.
The in-ground nitrogen-reducing biofilter
A layered media bed the effluent passes through. No blower, no power, no alarm, and no machine to fail at eleven at night. It takes more room in the ground than a tank does, and not every lot has that room or the soil profile for it.
Grant ceilings differ, and by a lot
Inside the DeLeon Springs priority focus area, the county's program pays up to $14,000 toward an aerobic unit and up to $8,000 toward a biofilter. That $6,000 gap is deliberate and it will pull you toward the aerobic unit. Whether it should depends on whether you would rather carry a lower installed cost or a lower running cost.
A worked example
Inside the DeLeon Springs grant area, an aerobic unit is quoted at $17,000. The grant takes $14,000 off and the balance is $3,000 plus permit fees. The unit then carries a maintenance contract and an operating permit for as long as the house stands, and an aerobic inspection at $350–$600 whenever one is required.
The biofilter on the same property attracts up to $8,000, so unless the biofilter quote comes in at least $6,000 below the aerobic quote, the aerobic unit leaves less on the table on day one. Over fifteen years of contracts, permits and a blower or two, that ordering can reverse. Ask both contractors to quote both, and ask the aerobic quote to include what the contract costs annually — not as a range, as a number, from the provider who would hold it.
Outside the grant area, there is no $6,000 thumb on the scale and the comparison is simply installed cost against running cost.
Questions worth asking before you sign
- Is this unit on the state's approved nitrogen-reducing list, and can you show me the entry?
- Who holds the maintenance contract, what does it cost a year, and what happens if they stop trading?
- Does my lot have the room and the soil for a biofilter, and if not, why not?
- If I am inside the grant area, are you a registered Volusia County vendor? If not, the grant cannot pay you.
A contractor who proposes an aerobic unit before anyone has established whether your address is even inside a priority focus area is selling equipment, not solving a problem. Ask why.
Verified as of September 16, 2026. We re-check these pages quarterly. The approved technology list is the state's and changes as products are certified and withdrawn; the grant ceilings are the county's and are funding-dependent. Confirm current availability before counting on a number.
All work is performed by local licensed, permitted Florida-registered septic tank contractors.