Plan for the installed system, electricity, and ongoing maintenance. Tennessee requires service from the start, includes a four-year manufacturer contract in the installed ATS price, and requires continued coverage after that.
Plan $15,000 to $30,000 or more for a complete aerobic septic installation, including its permitted dispersal field. HomeGuide lists a national installed range of $20,000 to $40,000+. Tennessee includes the initial four-year ATS maintenance contract in the purchase price. Budget separately for electricity and service renewals after year four.
Have a bid already? Compare your 20-year ownership costs.
We use $15,000 to $30,000+ for early budgeting while local installed-price data are limited. National guides cover different scopes: Fixr prices materials, and HomeGuide includes installation. Compare itemized bids for the same treatment unit, field, electrical work, and restoration.
| Cost item | Figure | What it covers |
|---|---|---|
| Aerobic unit and parts, before installation | $10,000 to $20,000 | Fixr's materials-only figure; labor, the field, and site work are extra |
| Installed aerobic system, national | $20,000 to $40,000+ | HomeGuide's range for an ATU as part of an engineered system |
| Installed with permitted dispersal, planning budget | $15,000 to $30,000+ | Includes treatment and the field; confirm mapping, electrical work, and restoration in the bid |
| TDEC permit and inspection, new system | $500 + $200 | State fee for a new alternative system up to 1,000 gallons per day |
| Service, years 1 to 4 | Included contract | Included in the installed ATS price; the rule has an abuse and third-party damage exception |
| Service, year 5 onward | Modeled at $500 a year | A private price set by the provider; Tennessee doesn't regulate it |
Sources: Fixr septic installation cost guide · HomeGuide engineered septic cost · EPA aerobic treatment fact sheet · Tennessee Rule 0400-48-01-.10
The tank that does the aerating is only half the job. Cleaner water still has to go into the ground somewhere, and in Tennessee that usually means a drip or other pressure field with its own pump, filter, and controls. Add the detailed soil map an alternative permit needs and a long wire run from the house, and a $10,000 box becomes a $20,000-plus project.
Tennessee requires a four-year manufacturer operation and maintenance contract in the installed ATS price. Read its scope and the rule's exception for homeowner abuse or third-party damage. A bid may itemize that included contract; ask whether the line is part of the total or an additional charge.
Electricity is the bill you'll feel monthly. EPA's 2000 aerobic treatment fact sheet puts fixed-film units at 1 to 4 kWh a day and suspended-growth units at 2.5 to 10 kWh a day. At 12 cents per kWh that works out to roughly $44 to $175 a year for fixed-film and $110 to $440 for suspended-growth. For a current estimate, ask for the proposed equipment's expected energy use and apply your own power rate.
Budget for contract renewal after the included first four years. A TDEC-approved provider visits every three months unless the state approves a different schedule, and the price is whatever the provider charges. This page models $500 a year; call two providers who service your brand before you sign anything, and ask whether the yearly price covers remote monitoring and any state tracking fee they pass along, so you can compare the full recurring cost.
Parts are the lumpy cost. EPA's homeowner guidance says many septic pumps and controls need replacement every 10 to 20 years, and blower life varies by model. If your unit uses chlorine tablets or a UV lamp, those are a small recurring buy too. Pumping happens when the provider's sludge measurement calls for it, and necessary pumping falls within the initial contract's scope, subject to the rule's damage exception.
In most cases, by a wide margin. The model below is plain arithmetic, so you can swap in your own bids, power rate, and contract price.
| 20-year cost | Conventional gravity | Aerobic with drip | How it's figured |
|---|---|---|---|
| Installed system | $11,500 | $22,500 | Midpoints of this site's $8,000 to $15,000 and $15,000 to $30,000 planning ranges |
| Service contract | $0 | $8,000 | $500 a year for years 5 to 20 (16 paid years); years 1 to 4 come with the install |
| Electricity | $0 | $3,000 | $150 a year for 20 years, about 3.4 kWh a day at 12 cents per kWh |
| Parts reserve | $1,500 | $5,000 | Aerobic: pumps, blower, and controls. Conventional: a baffle, effluent filter, distribution box, or line repair over 20 years |
| Pumping and other care | $5,000 | $5,000 | Kept equal on purpose. Pumping covered by the contract in years 1 to 4 would trim the aerobic side a little, so it errs high |
| 20-year modeled total | $18,000 | $43,500 | Today's dollars; no inflation, financing, or major failure |
The modeled gap is $25,500 in today's dollars. Every $100 of yearly contract price adds $1,600 to the aerobic total, because you pay it for 16 years. Every $50 of yearly power adds $1,000 over 20 years. The install bid moves the total dollar for dollar.
Two quick reruns: a $400 contract instead of $500 brings the aerobic total to $41,900. An install bid of $28,000 instead of $22,500 pushes it to $49,000. Use your installation bid and renewal price to run the same comparison.
The model doesn't predict field life, inflation, or which repairs your contract covers after year four. It exists to put the recurring bills next to the install price so you're comparing the whole cost of ownership.
Start with the example above, then replace the amounts with your bids and service prices. Compare only systems your property can be permitted to use. These example amounts are planning assumptions.
20-year planning totals
Aerobic totals $25,500.00 more over 20 years with these inputs.
Aerobic service: 16 paid years, totaling $8,000.00. Electricity: $3,000.00 over 20 years.
Total = installation + yearly service × (20 − included service years) + yearly power × 20 + parts reserve + pumping and other care.
Parts and other-care amounts cover the whole 20-year period. Use today's dollars throughout. The calculation leaves out inflation, financing, and major system failure. Check contract coverage so the same work is counted once. All calculations stay in your browser.
| Line item | Typical figure | What the bid should spell out |
|---|---|---|
| Soil and site work | Get a quote for the required mapping scope | Alternative systems need an extra-high-intensity soil map; survey, clearing, or extra pits add cost |
| Design | $1,000 to $3,000 nationally (HomeGuide) | Calculations, site plan, equipment schedule, and how many revisions are included |
| Treatment unit and tanks | $10,000 to $20,000 in materials (Fixr) | Model, rated flow, trash tank, aeration, filters, and disinfection where the permit calls for it |
| Drip field | $4,000 to $10,000 in materials (Fixr) | Tubing, filters, zone valves, controller, and the duplicate area the permit reserves |
| Electrical, controls, and alarm | $1,000 to $3,000 (our allowance) | Distance from the house panel, trenching, disconnect, and a licensed electrician |
| Excavation and restoration | $150 to $200 an hour for contractor time (Fixr) | Ask how rock is billed, and whether grading, seed, and straw are in the total |
| Deed notice | Register of Deeds recording fee | Tennessee requires a recorded deed restriction before TDEC issues the permit |
Ask every bidder for equipment model numbers, what the total leaves out, and the payment schedule, in writing. If one bid is thousands under the others, check whether it skipped the field or the electrician.
An ATU usually shows up when the soil can't take a conventional field and TDEC will accept advanced treatment paired with drip or another pressure field. In Maury County the usual trigger is too little soil above limestone for a gravity trench.
Cleaner effluent still needs a spot to go. An ATU can't create more land or shrink a setback, and some tracts have no approvable field area at all. The permit should name the site limitation and the full treatment-and-dispersal design you're pricing.
The engineered system cost guide compares ATU-plus-drip against LPP and mound prices, and the failed soil test guide explains when a new study area or a smaller design is worth trying first. For how the unit works inside, see how an aerobic treatment unit works.
The contract becomes yours at closing, and so does any lapse. Price the renewal before you make an offer, since a $700 contract and a $400 one differ by $4,800 over 16 years. Also ask whether the contract covers parts or only visits; a blower replacement outside coverage lands on you.
Pull the TDEC septic record and compare it with what's in the yard. An older unit with every visit report on file is easier to budget for than a newer one with a dead alarm and no paperwork. The buying a home with septic guide covers the rest of the inspection.
About our sources. Maury Septic uses the sources listed below, including Tennessee's aerobic contract rule, EPA power and pump-life data, and national cost guides. Follow the links for the underlying rules, fees, and guidance.
Tennessee Department of Environment and Conservation
Official rule index for permits, design, maintenance, soil consultants, installers, and fees.
Tennessee Secretary of State
Official current chapter text governing Tennessee subsurface sewage disposal systems.
Tennessee Department of Environment and Conservation
Conventional, repair, and alternative-system applications, plus soil-map requirements.
Tennessee Department of Environment and Conservation
Who needs a permit, application requirements, review timing, current state fees, and inspection duties.
Tennessee Department of Environment and Conservation
Official state viewer for locating septic-system permits, site sketches, and related records.
Tennessee Department of Environment and Conservation
State mapping standards for soil depth, restrictive layers, drainage, absorption rates, slope, site features, and SSDS interpretations.
U.S. Environmental Protection Agency
Failure signs, maintenance, pumping, water use, and drainfield protection.
Tennessee Geological Survey
State-published geologic, unstable-materials, flood-prone-area, mineral-resource, and sinkhole maps for Maury County.
Aerated wastewater treatment system is a brochure name for the same equipment installers call an aerobic unit or ATU; Tennessee's rule calls it an ATS. Price it the same way. Fixr lists $10,000 to $20,000 for the unit and parts alone, before anyone digs, so the field, wiring, and soil work make up the rest of an installed bid.
Power for the blower or aerator is the monthly piece. Using historical figures from EPA's 2000 fact sheet and an illustrative 12 cents per kWh, a fixed-film unit runs about $4 to $14 a month and a suspended-growth unit about $9 to $36. Actual power use depends on the model and aeration schedule. Budget separately for service renewals after the included four-year contract.
The manufacturer's four-year contract is included in the installed ATS price. It covers required inspections, component service, related disposal-field repairs, and sludge pumping when needed, with an exception for damage or failure caused by homeowner abuse or a third party outside the manufacturer's or technician's control. An approved provider must service the system from installation onward, normally every three months unless TDEC adjusts the interval. Keep coverage active when the initial contract ends.
Tennessee says no. The maintenance duty runs with the land, letting the contract lapse is a Class C misdemeanor under the rule, and if an owner cancels, the provider has to tell TDEC within 30 days. Homeowners can still do the cheap stuff that helps: keep the blower vents clear and call the provider the day the alarm light comes on.
Cost depends on which components can be reused, the approved repair, and access for equipment. TDEC lists no repair permit fee and a $100 inspection fee, but that saving does not establish the price of the work. Ask for a bid that separates retained equipment from new tanks, treatment, field, and electrical work.
Send us the job details, plus the permit, unit model, and disposal method if you have them. We'll look for a licensed installer who handles aerobic systems near you and pass your request along if we find one. Routine contract visits still have to come from a TDEC-approved maintenance provider.
Related: septic system cost · engineered system cost · aerobic septic service · aerobic versus conventional · drip systems · septic replacement · septic financing
Keep your permit, system sketch, and service records together. They help the next professional understand your property.