How Much Does Drain Field Replacement Cost in Tennessee?

National cost guides put drain field replacement at $3,000 to $15,000. One guide puts replacing the field alone at around $7,000. Another lists an average of $6,000. Size, slope, soil type, location and access decide where a job lands in that range.

These are market numbers, not our price list. The price ranges are national figures. The Tennessee part of the bill is the permit, and the state publishes those fees.

This post covers replacing a failed drain field on an existing home. A drain field is also called a leach field or a septic field. For the work itself, see our drain field repair and replacement service. If the tank has to go too, read what a new septic system costs in Tennessee.

What does it cost to replace a drain field?

Three national cost guides publish ranges for this work. The table puts their figures side by side. Where two guides price the same job differently, both ranges are shown.

The whole job row is the broad range for a replacement, and the design rows price the field by type. The spread is wide because these are very different jobs. Replacing a single broken line is a much smaller job than building a new field. A mound, or a move to new ground, sits at the top of the table.

What makes one drain field cost more than another?

One national guide names size, slope, soil type, location and access as the price drivers. Soil decides which design a site can take.

The EPA calls the gravel or stone drain field a design that has existed for decades. Water leaving the tank is piped to a shallow underground trench of stone or gravel. The EPA adds that these systems have a large footprint and may not suit every site.

The EPA lists mound systems as an option where soil is shallow or groundwater is high. Shallow bedrock is on that list too. Mounds also require a substantial amount of space and periodic maintenance, the EPA notes. In the table, a mound drain field runs $10,000 to $20,000.

Where the new field goes matters as well. If the old area cannot be used again, the field moves to new ground. One guide prices that move at $5,500 to $21,500 with the new field included.

Removal and cover add their own costs. Digging out the old field runs $1 to $5 per square foot in one guide. Sod over the new trenches adds $1 to $2 per square foot. Slope and access show up in the bill too, since the excavator has to reach the field.

Should you repair the lines or replace the whole drain field?

Start with what failed. A tank problem and a field problem can look alike from the yard. A dead pump or a stuck float can back up a system while the field is fine. Those are septic repair jobs on the tank side.

A septic inspection sorts out which side failed before anyone prices a new field. If you are not sure the field is the trouble, start with the signs of a failing drain field.

When one line is crushed or broken, a repair can replace that length and keep the rest. One guide prices individual leach line replacement at $20 to $45 per linear foot. Another puts drain field repair or rejuvenation at $1,000 to $5,000.

When the soil under the trenches has stopped taking water, repairs will not bring the field back. That field needs replacing. Age plays into the call as well. One national guide says a drain field lasts 20 to 25 years if properly built and maintained.

Does Tennessee require a permit to replace a drain field?

Yes. The state requires a permit to build a new septic system, or to repair or modify an existing one. Its construction permit covers repair to an existing faulty system. Replacing a failed drain field falls under that.

The permit costs little next to the dig. Here is what the state’s published fee schedule lists.

A failed site sometimes needs a different design, such as a mound.

The state’s permit page says a permit generally takes 10 days to process. Its septic FAQ says processing can take up to 45 days from receipt of a complete application. Our Tennessee septic permit guide covers who issues the permit and the steps in order.

How do you protect a new drain field?

A new field is a big spend, so care starts on day one. The EPA’s guidance for homeowners is short.

Do not park or drive on your drain field, the EPA says. Weight packs the soil down over the trenches. The EPA also says to plant trees the appropriate distance from the field, to keep roots out of the system.

Keep roof drains, sump pumps and other rainwater drainage away from the field. The EPA says excess water slows down or stops the wastewater treatment process.

Keep the tank on schedule. The EPA says household septic tanks are typically pumped every three to five years. It says systems should be inspected at least every three years. Regular septic tank pumping keeps solids in the tank and out of the new trenches.

Who replaces drain fields north of Nashville?

Wiley Rooter and Septic Pros is based in Greenbrier, in Robertson County. We handle failed leach field replacement across Robertson, Sumner, Cheatham, Davidson and Montgomery counties, plus Hartsville. Our crew does its own excavation with a compact track loader and a small excavator. It digs the new trenches and sets them with gravel and fabric.

The company brings 20 years of septic and sewer experience and is licensed, insured and bonded. Estimates are free. Call or text (629) 285-6381.