Septic inspections when buying or selling a house

A standard home inspection usually stops at the plumbing inside the walls. The septic tank and drain field are out in the yard, often unseen for decades, and they can be the most expensive thing on the property to replace. If you're buying a house on septic around Chattanooga, a dedicated septic inspection is cheap insurance. If you're selling, having one done first means no surprises once you're under contract.

Start with the paperwork

Before anyone digs, find out what's on file:

• Hamilton County: the county Groundwater Protection office keeps septic permit records, and the county's online permit portal has a document retrieval search for existing septic and building permits. An old permit usually shows the tank size, the bedroom count it was approved for, and a sketch of where the field lines run.
• Bradley County and the rest of Tennessee outside the contract counties: TDEC has a records search for existing septic permits.
• From the seller: pumping receipts and any repair invoices.

Compare the permit's bedroom count with the listing. If the house has grown from three bedrooms to five since the system was approved, the system may be undersized. Hamilton County's own form notes that adding a bedroom can require modifying the system to meet field-line footage.

What a real septic inspection includes

1. Locating and uncovering the tank. An inspection that never opens the tank isn't much of an inspection.
2. Pumping it. You can't see cracks, root intrusion, or the condition of the baffles in a full tank. Pumping during the inspection also shows whether water flows back from the field.
3. Checking tank condition. Cracks, a missing or broken baffle, a missing outlet filter, a deteriorating lid.
4. Running water through the house. Watching it arrive at the tank and checking for slow flow or leaks.
5. Walking and probing the drain field. Wet spots, odors, unusually green strips, signs of vehicles or construction over it.
6. A written report with what was found and what's recommended.

Ask the inspector up front which of these are included. Prices vary by contractor and by how much digging is involved.

County inspection letters and short-term rentals

Hamilton County's Groundwater Protection office offers its own services that sometimes come up in a sale. Its current fee list (read October 2026) includes an inspection letter ($105), a septic tank recertification letter ($180), an existing-system approval ($205), and a short-term vacation rental (STVR) septic inspection ($205). An existing-system approval is what the county uses when someone replaces a mobile home or adds a garage, pool or living space to a house already on septic. If you plan to rent the house out as a short-term vacation rental in the county's jurisdiction, the STVR permit includes a one-time septic inspection. Elsewhere in Tennessee, TDEC's fee rule lists an inspection of an existing system at $200.

Red flags for buyers

• No permit on file and no one knows where the tank is.
• A fresh pump-out right before listing with no record of anything before it. Ask why.
• New sod or fill over the field area.
• A driveway, patio, shed or pool built over or right next to the field. The EPA says not to build on or pave over a drain field.
• A well on the property that looks close to the tank or field. Tennessee's rule calls for 50 feet between a water supply and both the tank and the field.

If the inspection turns up problems, the repair page explains the usual fixes, and the permits page covers what the county will need.

Good questions

Does Tennessee require a septic inspection to sell a house?

We could not find a statewide point-of-sale septic inspection requirement for Tennessee. Lenders, buyers, and local programs such as Hamilton County's short-term rental permit may ask for one, so check with your agent and lender.

Should the tank be pumped as part of the inspection?

Yes, ideally. Pumping lets the inspector see the tank walls and baffles and watch for water flowing back from the field. Agree in advance who pays for the pumping.

How far does the well need to be from the septic system?

Tennessee's rule sets 50 feet between a water supply and both the septic tank and the disposal field as a minimum, and notes local conditions may call for more.