Fee schedule not yet confirmed Statewide range shown until we confirm with the county
Knox County septic permits
Knoxville, Farragut, Powell, Corryton and the county. What the state requires, what the ground here does to the price, and what to confirm with the county before you file.
Permit costs
We haven't confirmed Knox County's current fee schedule. Rather than publish a number we can't stand behind, here's the statewide picture and the exact question to ask when you call.
Across Tennessee, a construction permit for a septic installation generally runs $150 to $500, set by system type. Counties publish their own schedules within that, and they differ — Sevier County, for instance, charges $300 for a new system and $75 for a repair, then bills an inspection letter and water sample at $100 each on top.
When you call Knox County Environmental Health, ask for four figures specifically:
- New septic construction permit
- Repair permit — usually much cheaper, and often the right filing
- Inspection letter — this is what a lender will ask for at closing
- Re-inspection fee, and how re-scheduling works if an inspection fails
Ask whether they take cards. Several East Tennessee county offices still require payment by mail, which quietly adds days to a schedule that may be tied to a closing date.
The filing that saves the most money
A repair permit costs a fraction of a new-system permit almost everywhere in the state. If the work replaces a failed component of an existing system rather than installing a new one, it should be filed as a repair. Contractors sometimes default to the new-system filing because it carries fewer questions. Ask which one went in, and why.
Approval has to come before the work
A construction permit must be issued before anything is dug. Applications filed after a system is in the ground get rejected, and correcting that can mean excavating a finished installation. If a contractor offers to start while the paperwork catches up, that is your signal to get another quote.
Check the installer's permit, not just their licence
Two separate things are at play. You pull a construction permit through the county. Your contractor must separately hold an installer permit from TDEC — $200 for conventional systems, plus $100 for each alternative system type they're approved for, such as low pressure pipe, mound, oxidation lagoon or aerobic treatment.
This matters more than usual around Knoxville. If karst ground forces a mound design and your contractor only holds the conventional installer permit, they cannot legally build it. Ask which permits they hold before signing.
What the ground here does to the price
Knox County sits in limestone karst country, and that geology shows up directly on quotes. Where bedrock is shallow or solution channels run through it, there may not be enough soil depth beneath a drain field to treat effluent — which pushes the design toward a mound or treatment unit and roughly doubles the cost of the field. Two lots on the same street can price very differently for this reason, which is why a perc test done early is worth far more than the $300 to $800 it costs.
| Scope | Cost |
|---|---|
| Tank only, 1,000 gallon concrete | $2,500–4,500 |
| Conventional gravity system | $12,000–20,000 |
| Pressure distribution system | $15,000–25,000 |
| Mound system | $20,000–35,000 |
| Perc test | $300–800 |
Nearby counties
Fee schedules and ground conditions change at the county line, sometimes sharply. If your property sits near a boundary, check the neighbouring sheet too.