Verified as of September 16, 2026. We re-check these pages quarterly.
The rule
In Florida, an aerobic treatment unit must be under an active maintenance contract with an approved maintenance entity for as long as the system is in service. It is a state requirement, not a manufacturer's suggestion. Advanced treatment systems with pumps also require an operating permit, and periodic maintenance by a licensed contractor.
Permits and inspections here are issued by the Environmental Health section of the Florida Department of Health in Indian River County. The Florida Department of Environmental Protection is the governing authority for the onsite sewage program and has the authority to enforce the lagoon program.
What it costs
The county estimates $1,200 to $2,000 per year for maintenance and inspections on a nitrogen-reducing system. That is the figure county officials gave for this county in September 2026, and it is a bigger annual commitment than most owners expect — over a ten-year period it is comparable to the cost of the unit itself.
Ask what a contract includes before comparing two prices. Visit frequency, whether parts are covered, whether the pump-out is included and whether the reporting is done for you all move the number.
What the visits cover
- Blower or air pump check, and filter cleaning
- Effluent quality inspection
- Float switches, alarms and dosing controls
- Sludge level — an ATU still accumulates solids and still needs pumping. The maintenance visit is not a pump-out
- The service record filed as required
The alarm
A light or a buzzer almost always means the blower has stopped. Without air, an aerobic unit reverts to anaerobic treatment within days and stops meeting the 65 percent nitrogen standard it was installed to meet — the system keeps taking wastewater, so nothing looks wrong from inside the house.
Do not silence it and move on. Call whoever holds your contract.
If you would rather not own a machine
This is the strongest argument for looking at an in-ground nitrogen-reducing biofilter instead. An INRB does its treatment in engineered media in the ground rather than in a powered tank: no blower, nothing to hum, less to fail. It is one of the three routes the Florida Department of Environmental Protection recognizes to the ENR standard, alongside NSF 245-certified aerobic units and approved performance-based systems.
Whether an INRB suits your lot is a site question — available space and the depth to the water table decide it. But if the annual bill and the machine are what you are dreading, ask about it before you accept an aerobic unit by default. See what an ENR upgrade costs.
A worked example
A Vero Beach owner upgrades in 2027 and takes an aerobic unit at $20,000.
- Year 1: $20,000 installed, contract usually included in the first period
- Years 2–10: $1,200–$2,000 a year, so $10,800–$18,000
- A blower has a service life and will need replacing at some point in that decade
- Ten-year total: roughly $31,000–$38,000, before the blower
The same owner, told about all of that at quoting stage, may still choose the aerobic unit — but they will have chosen it rather than discovered it.
If you inherited one with the house
Find out three things before anything else: who has held the maintenance contract, whether the operating permit is current, and when the blower was last replaced. A unit with a lapsed contract is both a compliance problem and, in our experience, usually a mechanical one as well.
Verified as of September 16, 2026. We re-check these pages quarterly. Contract and permit requirements are set by Florida rule; the annual cost range is the county's estimate for this county. Confirm current requirements with the Florida Department of Health in Indian River County, Environmental Health.