How Much Does It Cost to Replace a Drain Field?

Matt Marandola
Written by Matt Marandola
Updated October 18, 2021
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The average cost to replace a drain field is around $6,000

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Drain fields are one of the most crucial parts of a septic tank system and when one goes, your backyard can flood and become pretty stinky. The cost of replacing a drain field depends on the size of the field and what type of septic system you have. Because of these reasons, replacing a drain or leach field can range anywhere from $2,000 for a tiny backyard to as high as $20,000 if you have a high-end system and a lot of land.

How Much Does It Cost to Replace a Drain Field by Linear Foot?

If you’re replacing every pipe in the drain field, then you’re looking at paying around $10 per linear foot of piping installed. This will change depending on the material of the piping. So the commonly used PVC piping can go as low as $5 per linear foot, while high-end copper pipes will go upwards of $15 per linear foot.

How Much Does It Cost to Replace a Drain Field by Type?

Not all septic systems are a simple tank underneath the ground with a drain field attached. Technology has made it so there are different ways to hide the leach field and how the wastewater is dispersed.

Mound Septic System Drain Field Cost

Mound septic system drain fields are typically on the high end, as these drain fields are not buried in the soil. Instead, you need to use an elevated mound of sand to cover the piping. Because this often requires pumping the sand uphill and then creating a mound to put the pipes in, the average cost to replace a mound septic system drain field is around $12,000.

Evapotranspiration Septic System Drain Field Cost

For those of you living in a dry, arid climate, you may have opted for an evapotranspiration septic system. These systems allow the water to evaporate through an open-air tank rather than running into a water table. Evapotranspiration septic system drain fields cost, on average, around $8,000.

Anaerobic Septic System Drain Field Cost

Anaerobic septic systems are the most basic type of septic system on the market. It simply brings waste down to the septic tank and then into the drain field. It relies on anaerobic bacteria to break down waste before continuing down the drain field to remove the anaerobic bacteria.

While simple in nature, these systems often require the most amount of land for your drain field. These systems cost around $5,000 on average, but around $3,500 of the cost comes from the drain field system installation.

Aerobic Septic System Drain Field Cost

Aerobic septic system drain fields don’t require nearly as much land as anaerobic ones. These systems utilize an aerator and electrical circuit to continuously supply oxygen to the aerobic bacteria inside. An aerobic septic system drain field costs around $7,000 on average.

Drain Field Replacement Cost Breakdown

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Labor, permits, and testing the field are all things you’re going to need to consider when replacing a drain field. This job often requires a lot of digging and construction, so it’s not recommended to skip out on informing your local municipality.

Labor

Installing a septic system in a yard is one of the most labor-intensive projects out there. It requires a lot of digging and back-breaking work to get done. Labor will typically make up 60% of the project’s total cost, which brings the average to around $3,600.

Permits

To ensure you don’t accidentally dig off your property or into the city's power lines or city pipes, you’ll need to file a permit ahead of time. Permits for replacing a drainage field will cost anywhere from $400 to $2,000, depending on your local government regulations.

Perc Testing

Perc testing is required before you can go any further with replacing a leach field. These tests check the drain field’s ground for its ability to absorb water and then filter it. If you’ve been using your drain field for several decades, there’s a chance that your current field may no longer be suitable and you may be required to move it or upgrade your system. The average cost of perc testing is around $1,000.

How Much Does It Cost to Replace a Drain Field Yourself?

Because you’ll need to file permits and the replacement requires perc testing, this is not a job you should tackle yourself. You should instead hire a septic company to tackle replacing the drain field. This job requires large excavators, multiple people, and even sometimes a crane in the event that there’s that much piping needed.

FAQs About Drain Fields and Septic Systems

How long do drain fields last?

If you’re maintaining your septic system, a drain field should last around 20 years on average. Though the field may not last that long, it’s important to get checked annually.

How much does it cost to convert an anaerobic septic system into an aerobic system?

If you no longer have the space available for a large drain field for an anaerobic system, you can always convert it into an aerobic option. The cost of converting an anaerobic system to an aerobic one is around $7,500 on average.

How much does it cost to pump a septic tank?

Septic tanks need pumping to keep everything running smoothly. This will keep your drain field healthy in the long run. The average cost to pump a septic tank is around $410.

How much does it cost to repair a drain field?

If the drain field isn’t that old, you may only need minor repairs to get everything back up and flowing. Drain field repairs vary drastically, as it all comes down to where the problem is located and the ease of access to repair the problem. With these considerations in mind, drain field repairs can cost anywhere from $2,000 to $15,000.

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