Installing a septic tank and drain field costs an average of $6,000, but you could pay between $5,000 and $12,000 depending on the size and type of the septic system.
The cost to replace a septic tank and drain field depends on the size of the field and type of septic system, but on average, prices range between $5,000 and $12,000. If you’re due for a new septic tank or drain field, here’s what you can expect to pay.
It may not be the most glamorous topic, but it’s an essential one. Learn septic tank and drain field replacement prices below so you can budget for potential costs. Contact a local septic tank installation company for a more accurate quote based on your specific needs.
Larger drain fields cost more to replace than smaller ones. That's because large areas require more time and labor to cover. Large areas also require large septic tanks, which are heavier and more difficult to install and maneuver than small tanks, further driving up costs.
Different septic systems require different drain field types to function. The type of drain field you have can affect costs.
| Type | Average Cost |
|---|---|
| Anaerobic drain field | $5,000 |
| Aerobic drain field | $7,000 |
| Evapotranspiration drain field | $8,000 |
| Mound drain field | $12,000 |
So, how do these systems differ?
Anaerobic drain fields are the most basic type that uses anaerobic bacteria to break down waste. The waste then continues down the field, where the bacteria is eventually removed.
Aerobic drain fields require a lot less land than anaerobic ones, and they use an aerator and electrical circuit to continuously supply oxygen to the aerobic bacteria inside.
Evapotranspiration drain fields allow the water to evaporate through an open-air tank rather than running into a water table.
Mound drain fields are not buried in soil but underneath a mound of sand.
If your septic system and drain field are in a tough-to-reach location, you can expect to pay more to replace it. Locations that aren't easy to access will require more time, labor, and potentially equipment, to get the job done, which increases costs.
Perc testing is required before replacing a leach field. These tests check the drain field’s ground for its ability to absorb water and 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 might need to move it or upgrade your system. The average cost of perc testing is around $1,300.
Installing a septic system in a yard is one of the most labor-intensive projects out there. It requires a lot of digging and other labor to get done. Labor will make up 60% of the project’s total cost, bringing the average to around $3,600.
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 $450 to $2,000, depending on your local government regulations.
If your septic tank fails but your drain field still works (or vice versa), you might only need a partial septic system replacement rather than a full one. On average, the price to install a new septic tank is between $3,000 and $10,000, while replacing a drain field costs around $7,000.
Similarly, if there’s only minor damage to your septic tank or drain field, you may be able to fix the specific issue instead of completely replacing your tank and drain field. As you might expect, the cost of repairing a septic tank or drain field is often just a fraction of what you’d pay for a full replacement.
For example, let’s say your septic system needs new baffles (the pipes that push wastewater into and out of the tank). Replacing these parts would cost between $300 and $900, but installing an entirely new tank would cost thousands. Or, if your drain field is clogged, it might only need a rejuvenation treatment, which is less expensive than a complete replacement.
There’s more than just installation, materials, and labor to consider when budgeting for the cost to replace a septic tank and drain field. Explore additional costs below.
| Added Cost | Average Price |
|---|---|
| Engineering fee | $125–$200 |
| Inspection | $200–$900 |
| Excavation | $1–$5* |
| Tree/root removal | $200–$2,000 |
| Sod installation | $0.35–$0.85* |
| New septic line | $100–$240** |
| Septic aerator | $300–$900 |
| Yard regrading | $1,000–$3,000 |
| Abandonment permits | $100–$250 |
*per square foot
**per linear foot
In some cases, you might want to consult with an engineer to optimize your septic system, especially in the case of mound systems. Engineering consultant hourly rates range from $125 to $200 per hour.
New septic systems require at least two professional septic inspections during construction to ensure the system meets safety standards. Septic system inspections cost between $200 and $900, depending on your system and municipality.
Many septic systems and drain fields require some land excavation to install. Excavation costs range from $1 to $5 per square foot.
If there are some trees and/or roots in the way, you'll likely need to pay a pro to remove them before replacing your septic tank and drain field. Tree removal costs range from $200 to $2,000 depending on the tree's size, location, and type.
If you want to lay sod on top of your new drain field, you should factor sod installation costs into the total budget. Sod costs $0.35 to $0.85 per square foot for the materials alone. If you hire a pro to lay it for you, you can expect to pay $1 to $2 per square foot total for sod installation.
Often you'll need a new septic line to connect your new septic tank to your new drain field. New septic lines range from $100 to $240 per linear foot to install.
Septic aerators help to break down waste materials in a septic tank, which reduces the workload on your drain field. Septic aerators cost $200 to $600 alone. Paying a pro to install one will drive those costs up to $300 to $900.
Sometimes, replacing your septic tank and drain field can make your yard less level, in which case you might want to regrade it. Yard regrading costs between $1,000 and $3,300, on average.
You need a permit to abandon a defunct leach field. Leach field abandonment regulations vary by city, but permits cost between $100 and $250.
This is not a DIY job. Septic tank and drain field replacement require specialized permits, licensing, and special equipment (including safety gear). Instead, hire a septic company to tackle this job for you. You can also hire a septic tank cleaner in your area to keep your system maintained properly throughout each year. This will decrease your chances of premature system failure and keep your tank and drain field in good condition for longer.
Installing a septic tank and drain field can get pricey, but you might be able to reduce your septic system replacement costs with these tips.
Taking proper care of your septic system will help extend its life span and make it less likely to need repairs or replacement. Here are some septic maintenance tips to keep your system running efficiently:
Pump the septic tank every three to five years.
Don’t flush anything that might clog the system, including paper towels, solid food, grease, and diapers.
Avoid using bleach and other strong chemicals when cleaning drains, sinks, and toilets.
Don’t park cars or add deep-rooted plants over your drain field.
Reduce your water usage.
Before you commit to a full septic system replacement, ask a pro if you have any other options. Depending on the state of your septic tank and drain field, you might only need a partial system replacement or a drain field rejuvenation. Partial replacement and rejuvenation would both cost less than installing an entirely new system.
Call a pro with any questions you have about your system, even if they're general questions. The more informed you are about your system, the better it will work and the better that pros can help you with it.
Before you can install a new septic tank or drain field, you’ll need to prepare your yard, which may include clearing trees and installing sod. If you’re hoping to save money, you could tackle some of this work yourself. However, make sure to check with your septic pro ahead of time. If you don’t prepare the site properly, it could cause septic system problems in the future.
The cost to replace a septic system may vary from company to company, so it’s a good idea to shop around and get estimates from multiple businesses. Aim to get at least three quotes so that you can compare them and make sure you’re getting the best deal.
Kelly Weimert contributed to this piece.
If you’re maintaining your septic system, your drain field should last around 20 years. However, it’s important to get it inspected every two to five years to help your system last as long as possible and make sure it’s in safe, working order. Contact a septic maintenance company in your area for a quote.
The average cost to pump a septic tank is $550, but it often ranges between $250 and $1,250, depending on the size of your tank and how full it is. Pros recommend pumping the septic tank every three to five years to keep your septic system working efficiently (and prevent a smelly mess in your backyard).
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.
There are a few things that can make your drain field fail. These include driving or parking vehicles or heavy machinery on the field, excess sodium in the soil, or having a high water table. You can prevent failure by ensuring your installer checks that your chosen location is suitable for a drain field and properly maintaining your system with the help of a professional.
There are a few signs that indicate a failing drain field. For instance, if your septic tank starts requiring more pumping than normal, your drain field might be failing. Other signs to watch for include poor drainage after rain, standing water or sewage over the septic system, a strong septic smell outside, new and healthy grass growing over the drain field, and plumbing backups in your sinks, bathtubs, or toilets.
No, you cannot have a traditional septic tank without a leach field. Without a field, there would be nowhere for the wastewater to go after it leaves your septic tank. If you don’t have enough room for a full-size leach field, you could consider another type of septic system that doesn’t take up as much space, such as a mound or sand filter system.
