| System | Typical installed cost | Ongoing |
|---|---|---|
| Aerobic treatment unit (ATU) | $10,000–$20,000 | maintenance contract + air pump every 5–10 yrs |
| Mound / raised fill | $12,000–$25,000 | same as conventional |
| Drip irrigation dispersal | $12,000–$25,000 | filter and pump service |
| Low-pressure dosing | $10,000–$18,000 | pump service |
| Performance-based (engineered) | $15,000–$30,000+ | per design |
Indian River County specifics. A nitrogen-reducing retrofit runs $15,000–$25,000 to retrofit an existing system (county estimate), and on new construction $12,500–$20,000 for a nitrogen-reducing system on new construction (county estimate) — both county figures given in September 2026. Annual maintenance and inspections are estimated at $1,200 to $2,000. There is no county grant offsetting any of it today: the county has applied for about $50 million in state grants, but that money is aimed at extending sewer and helping some private connections, not at buying on-site systems. Roughly 27,000 properties here are on this path. The honest state of funding
When you're required to go advanced: the county site evaluation says so. It is not a contractor upsell — the sanitarian's finding controls what can be permitted. If a contractor proposes an advanced system before the county has evaluated the site, ask why.