When the soil test rules out a gravity field, the price of the replacement depends mostly on which engineered design your soil allows. These are the ranges for each one, and where the money goes.
In Maury County, plan on $12,000 to $22,000 for a low-pressure pipe (LPP) system and $15,000 to $30,000 or more for a mound or drip system. HomeGuide's national range for engineered systems is $15,000 to $50,000+, against $3,500 to $8,500 for conventional. Pumps, controls, design, and extra soil work make up the difference.
Two national guides sit side by side here because they measure different things. Fixr's figures are materials only; HomeGuide's are installed. The Maury column is our planning figure for a complete, permitted job, so treat it as a budget line and get written bids before you commit.
| System | National published range | Maury planning range | What you're paying for |
|---|---|---|---|
| Low-pressure pipe (LPP) | $5,000 to $7,000, materials only (Fixr) | $12,000 to $22,000 | Dosing tank, pump, floats, control panel, alarm, electrical circuit, small-diameter laterals, and pressure testing |
| Mound | $25,000 to $50,000+ installed (HomeGuide); $10,000 to $20,000 materials (Fixr) | $15,000 to $30,000+ | Truckloads of specified sand, a raised distribution bed, pump and controls, shaping, and erosion control |
| Subsurface drip | $6,500 to $15,000 (HomeGuide); $4,000 to $10,000 materials (Fixr) | $15,000 to $30,000+ | Secondary treatment, which an approved aerobic unit can provide, plus filters, zone valves, and a controller |
| Aerobic treatment unit (ATU) | $20,000 to $40,000+ installed (HomeGuide); $10,000 to $20,000 materials (Fixr) | $15,000 to $30,000+ | Aeration, clarifier, alarms, and a dispersal field; full breakdown on the aerobic cost page |
| Recirculating sand filter | $15,000 to $25,000+ (HomeGuide) | $20,000 to $30,000+ | A lined sand or gravel filter box and recirculation pump, always designed by a licensed engineer |
| Conventional gravity (for comparison) | $3,500 to $8,500 (HomeGuide) | $8,000 to $15,000 | No pump or panel when the field sits downhill of the tank |
Sources: HomeGuide engineered septic cost · HomeGuide septic system cost · Fixr septic installation cost. For drip, confirm that the bid includes the secondary treatment Tennessee requires, as well as the dispersal field.
The soil consultant checks depth, texture, wetness, and other site conditions. Tennessee's rules then set the limits for each design. If more than one option qualifies, compare the full installation price, service requirements, and use of the yard.
| System | Minimum soil depth | Other site rules |
|---|---|---|
| LPP | 30 inches over rock or a restrictive layer (a modified LPP can use up to 6 inches of fill) | Soil absorbs at 10 to 75 minutes per inch (76 to 120 with acceptable perc tests and no water problems); no slopes over 30%; room for a full-size duplicate field |
| Mound | 24 inches over a restrictive layer (20 inches on a modified mound with 4 inches of extra sand) | Sand bed sized at 1.2 gallons per square foot per day, so a 3-bedroom house at 450 gallons a day needs a 375 sq ft bed |
| Subsurface drip | Drip line 8 to 12 inches deep, with 12 inches of undisturbed soil under it before rock | Water has to be treated to secondary standards first; a maintenance contract for the life of the system |
Depth can rule an option out early. Rock at 22 inches is too shallow for a modified LPP (24 inches of natural soil plus up to 6 inches of fill) or a standard mound (24 inches). A modified mound can be evaluated with 20 inches, provided the soil, slope, area, and other requirements also qualify. Sinkholes add separate setbacks: at least 15 feet for a tank and 25 feet for a field.
Start with the soil and site evaluation, and if nothing conventional fits, read the failed soil test options before you pay anyone to draw a design.
A conventional system is a tank, a pipe, and gravel trenches downhill. Everything an engineered system adds is there to spread the water more evenly, clean it harder, or build usable soil on top of the old.
Labor is still the biggest single share. HomeGuide puts it at 50% to 70% of a septic job's total.
| Line item | National figure | In a Maury County bid |
|---|---|---|
| Soil work | $200 to $1,500+ for a perc test (HomeGuide) | Get a quote for the required extra-high-intensity soil map from a TDEC-approved consultant; a perc-test price covers different work |
| Design | $1,000 to $3,000 (HomeGuide); $600 to $800 for a contractor-drawn design (Fixr) | Ask whether revisions, product submittals, and install-day questions are included |
| TDEC permit and inspection | $500 to $2,000 (HomeGuide) | $500 permit plus $200 inspection for a new alternative system up to 1,000 gallons per day |
| Pump | $200 to $500 to replace (Fixr) | Get the model number and duty point on the bid so a future replacement matches |
| Alarm | $100 to $500 (Fixr) | Should be in the panel price on any pumped system; confirm it's wired and tested at startup |
| Electrical | Electrical permit often required (HomeGuide) | $1,000 to $3,000 is our allowance; the run from your panel to the pump tank moves it most |
| Labor | 50% to 70% of the total; $50 to $200 an hour for specialized crews (HomeGuide) | Rock and wet clay slow a crew down, and some bids price rock separately |
| Site prep | Excavation $2.50 to $15 per cubic yard; regrading $500 to $5,000; trees $400 to $1,200 each (HomeGuide) | Clearing a wooded tract for both the field and its reserve area adds up fast |
“Engineered” is what people search for, but TDEC calls these alternative systems, and a licensed engineer isn't always required. Under Rule 0400-48-01-.15, LPP and mound systems need one only above 750 gallons per day. Tennessee figures 150 gallons per bedroom per day for alternative systems, so a five-bedroom house (750) stays under the line and a six-bedroom house (900) crosses it.
Drip is stricter. TDEC considers a drip permit only when a licensed engineer designed it or the department already approved it as a packaged system. Sand filters and recirculating gravel filters always need an engineer under Rule 0400-48-01-.10. Fees track who draws it: Fixr lists $600 to $800 for a contractor-prepared design, and HomeGuide puts engineering at $1,000 to $3,000.
Whoever draws it, the fee should buy elevations, dose volume and pump sizing, the zone layout, material quantities, and the attachments TDEC wants with the application. Ask how many revisions are included and whether the designer will take the installer's calls during the build.
EPA's homeowner guidance says many septic pumps and controls need replacement every 10 to 20 years. Fixr puts a failed tank pump at $200 to $500 and an alarm at $100 to $500, before the service call. Treat year 10 as a checkpoint: pull the model numbers, make sure parts are still made, and get a replacement price while nothing is broken.
The control panel is the brain. EPA's control-panel fact sheet describes it starting and stopping the pump, timing doses, reading the floats, and sounding the alarm. An alarm that keeps coming back is a symptom, so have a technician find the cause before you replace parts.
Pump-outs cost about the same as on a conventional tank (see septic pumping cost), though a pumped system adds a dosing tank to check. Drip and ATU owners need an active maintenance contract from installation onward. An ATS includes a four-year manufacturer contract in its installed price; confirm whether it also covers the drip equipment. Budget for continued coverage; the aerobic system cost page prices that out.
About our sources. Maury Septic uses the sources listed below, including Tennessee's alternative-system rules and national engineered-system price data. Follow the links for the underlying rules, fees, and guidance.
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 rule index for permits, design, maintenance, soil consultants, installers, and fees.
Tennessee Department of Environment and Conservation
Current state policy for digital permit sketches, attachments, reproducible field references, setbacks, and FileNet record quality.
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.
U.S. Environmental Protection Agency
Functions, components, advantages, costs, and maintenance context for pumps and control panels used with LPP, ATU, and drip systems.
U.S. Environmental Protection Agency
Design, shallow pressure dosing, components, site limits, distribution performance, maintenance, alarms, and operating-cost categories for LPP systems.
U.S. Environmental Protection Agency
Mound components, elevated sand treatment, site limitations, pressure dosing, construction risks, landscaping, failure signs, and maintenance practices.
Tennessee Geological Survey
State-published geologic, unstable-materials, flood-prone-area, mineral-resource, and sinkhole maps for Maury County.
Plan on $12,000 to $30,000 or more in Maury County, with LPP at the low end and mound or drip at the high end. On top of that come the state fees: $500 for the permit and $200 for inspection on a new alternative system up to 1,000 gallons per day, against $500 total for a conventional one. Repairing an existing home's system carries no permit fee, only the $100 inspection.
Plan on $12,000 to $22,000 for a complete Maury County LPP job. Fixr's $5,000 to $7,000 for pressure distribution is materials only, before installation. The finished job adds the septic tank, a dosing tank, the pump, floats, an alarm panel, an electrician, and a pressure test of the laterals before they're covered.
HomeGuide lists $25,000 to $50,000 or more installed, and Fixr lists $10,000 to $20,000 for materials. We use $15,000 to $30,000 or more for early budgeting while local installed-price data are limited. Haul distance for the specified sand, the size of the bed, and how easily a loaded truck can reach the spot decide where your bid lands.
Budget $15,000 to $30,000 or more for treatment and drip dispersal. Fixr lists $4,000 to $10,000 for drip materials, and HomeGuide lists $6,500 to $15,000 for drip distribution. Check each bid for the treatment equipment, tanks, controls, electrical work, and field. Tennessee requires secondary treatment and a lifetime maintenance contract. Our aerobic cost guide shows an example 20-year budget.
HomeGuide says 1 to 3 weeks on average, longer on complicated sites. Getting to the permit often takes longer than the build. An alternative application needs an extra-high-intensity soil map first, then design and TDEC review, and a wet spell can stall the dig for days.
Send the soil map or permit and a few details about the lot, and we'll try to put your request in front of a licensed alternative-system installer near you. Bids only line up when everyone prices the same approved design.
Related: septic system cost · septic system types · low-pressure pipe systems · mound systems · drip distribution systems · aerobic system cost · gravity vs pump systems · septic permit guide
Keep your permit, system sketch, and service records together. They help the next professional understand your property.