How Much Does Septic Tank Installation Cost?

Average National Cost
? All cost data throughout this article are collected using the RS Means construction materials database.
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$3,500 – $11,100

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Updated On

February 17, 2024

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If you live in a rural area or plan to build a new home in the country, you’ll need a septic tank to handle the waste you produce in your home. These systems are responsible for waste removal and filtration so that wastewater can be released into the soil. 

We use real-world data from RSMeans, a building materials database used by contractors across the United States, to provide you with real septic tank installation data. Along with this data tool, we gather real quotes so you know what to expect when you install a new septic tank.

Ready to install or replace the septic tank in your home? Use the tool below to connect with a professional plumber.

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Highlights
  • On average, the cost of septic tank installation is between $3,500 and $11,000.
  • It can cost as much as $20,000 or more to install a septic tank, depending on the type and scope of the project.
  • Most homeowners only need a maximum-1,000-gallon septic tank.

How Much Does It Cost to Install a Septic Tank?

On average, installing a septic tank costs between $3,500 and $11,000, but installation can cost anywhere from $3,000 to more than $20,000. Septic tanks only cost $500 to $2,500, so most of the cost can be attributed to labor and installation. This is good news for homeowners who already have a septic tank since you’ll just have to replace the tank, but it means that initial installation is quite a costly project.

Low EndNational AverageHigh End
$3,000$3,500 – $11,100$20,000

Cost data include the material costs and labor, if applicable. All cost data in this article were gathered from RSMeans construction materials and labor database and bids from top contractors.


How Do Septic Tank Costs Differ by Aerobic vs. Anaerobic?

Anaerobic septic systems are the conventional type and the most affordable to install. However, they’re not as efficient as aerobic septic systems, which are more than double the cost. 

Type of Septic TankAverage Cost
Anaerobic$3,000 – $8,000
Aerobic$10,000 – $20,000

Cost data include the material costs and labor, if applicable. 

Anaerobic Septic System

As the most affordable type of septic system to install at $3,000 to $8,000, conventional septic systems use anaerobic bacteria that don’t consume oxygen to break down your home’s solid waste. Anaerobic systems have a simple design that consists of a pipe that leads from your house to the tank and then to the drain field.

When your kitchen, bathroom or laundry room discharges waste, it is sent to your anaerobic septic system, where solids (and fats/grease) are separated from the wastewater and anaerobic bacteria start to break down the waste. The septic system discharges the effluent (wastewater) into a large leach field where oxygen-consuming bacteria continue the breakdown process.

Aerobic Septic System

Aerobic septic systems are much more efficient but also more expensive to install at an average of $10,00 to $20,000. These systems break down waste much better than traditional septic systems, so you don’t need a large drain field, which is perfect for anyone who lives on a smaller property. 

This type of septic system relies on aerobic bacteria that need oxygen to break down waste. Because aerobic bacteria are used, aerobic septic tanks produce higher-quality effluent that can be directly transferred to soil.

Interested in learning more about how a septic system works? Check out the video below.


How Does Material Affect Septic Tank Pricing?

The material your septic tank is constructed from can impact the total cost. Concrete and plastic septic tanks tend to be the most affordable but are more prone to damage and cost more to repair when they are damaged. Fiberglass tanks have a higher price tag but are built from a stronger material.

If you currently have a steel septic tank, you should replace it with a tank made from more durable material. Unlike steel tanks, concrete, fiberglass, and plastic tanks are not prone to rust and corrosion.

MaterialAverage Cost (Septic Tank Materials Only)
Concrete$700 – $2,000
Fiberglass$1,200 – $3,000
Plastic and polyethylene$800 – $2,900

Cost data include the material costs. 

Steel septic tank

Concrete

Concrete septic tanks are the most common type installed in the United States because they are durable and affordable. At $700 to $2,000 for the septic tank, concrete tanks have an average lifespan of 20 to 30 years, so they can be a good investment. Concrete septic tanks are rust-proof but can crack, leading to expensive septic tank repairs.

New concrete septic tank

Fiberglass

Fiberglass septic tanks are the most expensive at $1,200 to $3,000 for the tank, but because they weigh less than concrete, they are less expensive to install. Fiberglass doesn’t crack and is stronger than plastic, so it’s a good choice for homeowners looking for a durable and low-maintenance septic system.

New fiberglass septic tank

Plastic and Polyethylene

Plastic and polyethylene septic tanks are also affordable at $800 to $2,900 for the tank but are not approved for use in every state because they can break when exposed to pressure or certain soil conditions and climates. 

New plastic septic tank
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Which Factors Impact Septic Tank Installation Cost Estimates?

The material and type of septic tank are only two factors that play into your total cost, and many other cost factors impact your bill. In the following sections, we’ll cover leach field installation, tank size, alternative system types, and additional costs to look for.

How a septic system work

Leach Field Installation Costs

The leach field, also known as the drain field, is one of the most important parts of many septic systems. Your drain field is a series of underground pipes situated next to your septic tank, where the septic system disposes of wastewater. Once the wastewater is released into the soil, soil bacteria continue to break down the waste. Not all septic systems need drain fields, but when they do, they’re expensive to install at $10,240 to $14,370 on average.

Leach Field SizeSeptic Tank SizeAverage Cost
600 square feet1,000 gallons$10,240
750 square feet1,500 gallons$12,430
1,000 square feet1,500 gallons$14,370

Cost data include the material costs and labor, if applicable. 

Today’s Homeowner Tips
If you live on a smaller property, you may not have room for a large leach field. In this case, you’ll need an aerobic septic system installed.

Septic System Size

The size of your septic system also plays a major role in up-front costs. As can be expected, the larger your septic system, the more it will cost. For example, a 500-gallon septic tank might cost between $500 and $900, but a 1,500-gallon septic tank will cost up to $2,500. Most homeowners need a 1,000-gallon tank or smaller, but your plumber or contractor can help you choose the right size septic tank system for your home.

Check out the table below for the cost ranges of septic tanks by size and number of bedrooms in your home.

Septic Tank Gallon SizeNumber of BedroomsAverage Cost
500 gallons1 bedroom$500 – $900
750 gallons2 bedrooms$700 – $1,200
1,000 gallons3 to 4 bedrooms$900 – $1,500
1,200 gallons4 to 5 bedrooms$1,200 – $1,600
1,500 gallons5 to 6 bedrooms$1,500 – $2,500

Cost data include the material costs. 

Alternative Septic System Types

Although most homeowners will opt for an anaerobic septic system, other septic system designs are available. For example, a mound septic system uses piles of sand instead of a drain field, and an evapotranspiration septic system uses an open-air tank to let the wastewater evaporate naturally. These are not commonly used in homes unless you have very limited space for your septic system, but they are still an option.

Below you’ll find the average septic system cost by type, and you’ll notice that these alternative types tend to be more expensive than traditional septic models.

Septic TypeAverage Price Range
Built wetland$8,000 – $15,000
Chambered$5,000 – $12,000
Drip$8,000 – $18,000
Evapotranspiration$10,000 – $15,000
Mound$10,000 – $20,000
Sand filter$7,000 – $18,000

Cost data include the material costs and labor, if applicable. 

Septic Tank Installation Additional Costs

The septic tank and labor costs will likely make up the bulk of your total cost, but other smaller costs can quickly add thousands of dollars to your bill. Land excavation is the most expensive additional cost because you’ll need a 6.5-foot by 3-foot trench, which can cost anywhere from $1,500 to $6,000.

Another expensive add-on cost is a soil percolation test. These tests inform the drain field design by determining how long a certain soil type will take to absorb a certain amount of water. You’ll pay between $250 and $2,000 if you need a perc test.

You can find other common additional cost factors in the table below (some are replacement part costs).

Additional Installation CostAverage Price Range
Baffle$250 – $400
Land excavation$1,500 – $6,000
Building permits$250 – $2,300
Pump alarm$600 – $3,000
Riser installation$300 – $750
Septic distribution box$50 – $700
Sewer line or sewer pipe$100 – $250 per linear foot
Soil test and percolation test$250 – $2,000
Tank lid replacement$100 – $300
Septic tank pump replacement$600 – $1,500

Cost data include the material costs and labor, if applicable. 

Septic tank excavation

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What Are the Benefits of Septic Tank Installation?

Septic tanks are necessary if you live in a rural area, but they also come with their own benefits. Septic tanks are low maintenance, offer onsite water treatment, and are even environmentally friendly.

Low Maintenance

Septic tanks only need to be pumped every three to five years to remove accumulated solids, so there’s not much you have to do in between to maintain it. However, it’s always a good idea to get annual maintenance to make sure your system is in good working condition.

Onsite Water Treatment

With a septic system, you have your own water treatment system. Your septic system and drain field are specifically designed to release treated water to the groundwater so the latter doesn’t become contaminated. 

Environmentally Friendly

Sewer lines can sometimes leak and contaminate groundwater, but septic systems are much less likely to be problematic. Because your septic system is likely connected only to your home, there’s also less strain on it, making it much less likely to deteriorate quickly.

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Professional vs. DIY Septic Tank Installation

We don’t recommend DIY septic tank installation because it’s a complex system connected to nearly every major plumbing component in your home. Further, you need large equipment to excavate a hole for the tank to live in. Instead, it’s best to leave this home project to the professionals.

Doing Septic Tank Installation Yourself

You shouldn’t install a septic tank yourself. To complete this project, you need specialized permits from your local jurisdiction, heavy-duty equipment to excavate, and professional expertise to design your drainage system. If your septic tank is installed incorrectly, it could lead to sewer backups, groundwater contamination, and thousands of dollars in repairs. 

Hiring a Professional for Septic Tank Installation

Because septic system installation is complex, we recommend working with a professional installer to get the job done correctly. Your local contractor or plumber will work with you to choose the best septic system for your home. Plus, if you have a connection with a local plumber, you’ll have someone who can perform regular maintenance on your septic system.

Use the steps below to get started with your septic tank installation:

  1. Find local experts near you: Provide your information below, and a professional septic tank installer will be in contact to discuss your project.
  2. Get a quote from a few options: If you can, we recommend you get at least two quotes to compare costs and choose the best septic system for your needs.
  3. Consult them about their recommendations: If you are unsure about the type and size of your septic system, talk to the plumber or contractor to see what they recommend.
  4. Choose your quote: Once you’ve gathered a few quotes, choose one that best fits your needs and budget.

Ready to install or replace your septic system? Use the tool below to get connected with a septic tank installer near you:

Get Free Estimates From Professional Plumbers
Match with a plumbing expert to help you with installation or repair.

So, Is Septic Tank Installation Worth It?

You don’t need a septic system if you’re in a suburban or urban area connected to a municipal system. But if you live in a rural area and want indoor plumbing, you’ll need a septic tank. These systems take the solid waste from your home and use bacteria to break it down so that it can be released into the soil. Septic tanks cost an average of $3,500 to $11,000, but alternative types can cost up to $20,000 to install. 


FAQs About Septic Tank Installation Cost

What is the cheapest septic tank to install?

The cheapest new septic system to install is a traditional anaerobic septic system. Unlike aerobic or alternative septic system types that cost up to $20,000 to install, anaerobic systems cost an average of $3,000 to $8,000.


How long do septic tanks last?

Most septic systems have a lifespan of 20 to 40 years. With regular maintenance, your septic tank should last at least 25 to 30 years, so it’s worth the annual investment.


What do I need to know about septic tanks?

You only need a septic tank if you’re not on a municipal sewer system. If you live in the country or a rural area, you’ll need a septic tank and system if you plan to have indoor plumbing. When solid waste leaves your home, it goes to the septic tank to be turned into effluent (wastewater) and remaining solids that need to be removed every few years. Septic tanks are made from fiberglass, concrete, or plastic and sit underground.


How do I estimate my septic tank replacement size?

To determine the size of your new septic tank system, you need to determine how many people will use the system on a regular basis, count the number of bathrooms you have, and assess how many plumbing fixtures are in your home. For example, if you have a one-bedroom home, you can get away with a 500-gallon tank. But if you have a three-bedroom and four people, you’ll need a larger tank. Ask your contractor if you are unsure what size tank you need.


Editorial Contributors
avatar for Alora Bopray

Alora Bopray

Staff Writer

Alora Bopray is a digital content producer for the home warranty, HVAC, and plumbing categories at Today's Homeowner. She earned her bachelor's degree in psychology from the University of St. Scholastica and her master's degree from the University of Denver. Before becoming a writer for Today's Homeowner, Alora wrote as a freelance writer for dozens of home improvement clients and informed homeowners about the solar industry as a writer for EcoWatch. When she's not writing, Alora can be found planning her next DIY home improvement project or plotting her next novel.

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photo of Roxanne Downer

Roxanne Downer

Editor

Roxanne Downer is a commerce editor at Today’s Homeowner, where she tackles everything from foundation repair to solar panel installation. She brings more than 15 years of writing and editing experience to bear in her meticulous approach to ensuring accurate, up-to-date, and engaging content. She’s previously edited for outlets including MSN, Architectural Digest, and Better Homes & Gardens. An alumna of the University of Pennsylvania, Roxanne is now an Oklahoma homeowner, DIY enthusiast, and the proud parent of a playful pug.

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