Hilary Cairns is a writer with 12 years of professional writing experience. She has covered a diverse set of topics such as custom home building, plumbing, HVAC, energy efficiency, and others.
A graduate of SUNY New Paltz with a bachelor's degree in English and a concentration in Creative Writing, she discovered her passion for helping businesses and organizations deliver impactful content that changed lives.
Originally from New York, Hilary now calls Florida home (along with 2 cats). When not immersed in her writing work, she enjoys playing video games, reading Stephen King, and researching her (and her friends') genealogy.
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.
Updated On
April 11, 2025
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Septic tank installation typically costs $8,000, with most homeowners spending between $4,000 and $12,000 depending on the size of the system and property conditions. For complex systems or tight spaces, total costs can reach $20,000 or more.
If your home isn’t connected to a municipal sewer system, you’ll need a septic system to handle wastewater safely. These underground setups collect sewage, separate solids, and filter wastewater before releasing it back into the soil. Septic systems are most common in rural areas and new home builds off the grid.
The biggest cost factor is the type of system you choose. Traditional anaerobic systems are the most affordable, starting around $3,000, but they require lots of space. If you’re on a smaller lot, you may need an aerobic system, which costs more but works in tighter areas. Tank material, soil conditions, drain field needs, and local permit requirements also affect the final price.
Installing a septic system is not a DIY job—it involves soil testing, excavation, and local code compliance. Hiring a licensed contractor ensures everything is sized correctly and installed to code.
In this guide, I’ll walk you through average septic tank installation costs, system types, size recommendations, and how to choose the right pro for the job.
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Boiler Replacement
Generally, you can expect to pay $5,300–$9,500 to replace your home’s boiler. Price will vary for electric, gas, and wood models.
On average, the cost of septic tank installation is between $3,610 and $12,412.
It can cost as much as $20,000 or more to install a septic system, depending on the type and scope of the project.
Many states require septic tanks to be at least 1,000 gallons.
How Much Does It Cost to Install a Septic Tank?
On average, installing a septic tank costs $8,011, with most homeowners paying between $3,610 and $12,412. However, some models, such as aerobic septic systems, can cost up to $20,000.
Labor and installation make up most of the total expense—the tanks themselves only cost $500 to $2,500. If you’re simply replacing a septic tank rather than installing one for the first time, your total should be less than the national average.
Low End
National Average
High End
$3,610
$8,011
$20,000
How Do Septic Tank Costs Differ by Type?
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 Tank
Average Cost
Anaerobic
$3,000 – $8,000
Aerobic
$10,000 – $20,000
Anaerobic Septic System
The most affordable type of septic system to install at $3,000 to $8,000, conventional septic systems use anaerobic bacteria to break down your home’s solid waste.
When your kitchen, bathroom, or laundry room discharges waste, it’s sent to the anaerobic septic system. The system separates solids, fats, and grease from the wastewater while the anaerobic bacteria break down the waste. The unit then discharges the effluent (wastewater) into a large drain, or leach, field where oxygen-consuming bacteria continue the breakdown process.
However, this system isn’t the best option if you have limited space or if the surrounding soil can’t absorb the wastewater quickly.
Aerobic Septic System
Compared to anaerobic options, aerobic septic systems are much more efficient but also more expensive to install at an average of $10,000 to $20,000. Aerobic bacteria use oxygen to break down the waste. As a result, you don’t need a large drain field, which is ideal for anyone who lives on a smaller property.
Interested in learning more about how a septic system works? Check out the video below.
How Does Material Affect Septic Tank Pricing?
Concrete and plastic septic tanks tend to be the most affordable, but concrete is more durable than plastic. Fiberglass tanks are stronger than both but come with a higher price tag.
If you currently have a steel septic tank, you should replace it with a more durable material. Concrete, fiberglass, and plastic units aren’t prone to rust and corrosion.
Material
Average Cost (Septic Tank Materials Only)
Concrete
$700 – $2,000
Fiberglass
$1,200 – $2,000
Plastic and polyethylene
$500 – $2,000
Concrete
Most homeowners with septic tanks in the United States opt for concrete, thanks to its durability and affordability. You’ll often find this material priced between $700 and $2,000. Rust-proof, concrete septic tanks have a lifespan of 20 to 30 years. However, cracks can lead to expensive repairs.
Fiberglass
Fiberglass septic tanks are the most expensive at $1,200 to $2,000, but since they weigh less than concrete, they’re less expensive to install. Fiberglass is durable, low maintenance, and stronger than plastic. Plus, it doesn’t crack.
Plastic and Polyethylene
Plastic and polyethylene septic tanks are also affordable, averaging from $500 to $2,000. Corrosion-resistant, they’re lighter and less prone to cracking and water damage than concrete. However, not all states allow their use, as they can break down when exposed to pressure or in certain soil conditions and climates.
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What Other Factors Impact Septic Tank Installation Cost Estimates?
Various other factors can impact your total septic tank installation bill, including leach field installation, tank size, and more. There are also other types of septic systems to choose from that might meet your needs.
Alternative Septic Systems
Although most homeowners opt for an anaerobic septic system, there are other types available. Here’s a look at some common types along with their average costs, including labor:
Mound: One of the most expensive types of septic systems, averaging $10,000 to $20,000, mound systems use piles of sand or gravel rather than a traditional drain field. There, bacteria further treat the water before it’s dispersed into the ground.
Evapotranspiration: An open-air tank lets the wastewater evaporate naturally, and homeowners can add plants to speed up the process. These systems tend to cost between $10,000 to $15,000. Evapotranspiration tanks aren’t common, except in homes with very limited space.
Built wetland: Also known as a constructed wetland, these systems mimic natural wetlands. They use microorganisms and plants to treat wastewater before it’s released to a drain field, pond, or lagoon. They average $5,000 to $12,000.
Chambered: Costing between $5,000 and $12,000, chambered septic tanks consist of a number of chambers filled with soil. As the wastewater moves through the chamber, it’s treated by microbes. It’s ideal for areas with high water tables or where gravel is hard to come by.
Drip: Drip, or drip distribution, systems use aerobic bacteria, “dripping” the wastewater through the system for treatment until it’s dispersed into the grass. They range from $8,000 to $18,000.
Sand filter: Sand filters, which often cost between $7,000 and $18,000, work with septic tanks as a secondary treatment. Effluent flows into the sand, where it’s filtered, retreated, and then moved to the drain field.
Leach Field Installation
The leach field, also known as the drain field, is one of the most important parts of many septic systems. It’s a series of underground pipes situated next to the septic tank, where the system disposes of wastewater. Once it releases the effluent into the soil, bacteria continue to break down the waste.
Drain fields are expensive to install—ranging from $5,000 to $12,000, depending on the type—but not all septic systems need one.
Leach Field Type
Average Cost
Anaerobic
$5,000
Aerobic
$7,000
Evapotranspiration
$8,000
Mound
$12,000
Today’s Homeowner Tip
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 larger the septic system, the more it costs. A 500-gallon septic tank averages between $500 and $900, while a 1,500-gallon septic tank can cost up to $2,500. Some areas’ laws dictate the minimum size allowed. In much of the United States, you need a 1,000-gallon tank or larger. Your plumber or contractor can help you choose the right size for your home.
The table below provides size recommendations based on a home’s number of bedrooms, along with cost data for each:
Septic Tank Size (Gallons)
Number of Bedrooms
Average Cost
500
1
$500 – $900
750
2
$700 – $1,200
1,000
3 – 4
$900 – $1,500
1,200
5 – 6
$1,200 – $1,600
1,500
6 – 7
$1,500 – $2,500
Additional Costs
Project requirements can quickly add thousands of dollars to your septic tank installation bill. For example, if you need land excavation, it can increase the total price by $1,500 to $6,300.
These are some of the most common additional factors that could add to the septic tank cost:
Land survey and excavation: Before you can install a new system, you need a land survey, averaging $330 to $900. In addition, a traditional septic tank needs a 6.5-foot by 3-foot trench, which can cost between $1,500 and $6,000.
Soil and percolation test: You also need a soil and percolation test to determine the best system for your home. A professional uses a perc test, which costs between $700 and $2,000, to inspect the soil type, sediment layers, and how quickly the soil will absorb the treated wastewater.
Permits: Some areas require building permits for septic system installation, ranging from $450 to $2,300.
Riser installation: Septic tank risers make it easier to inspect the tank’s condition and perform maintenance. It’s not necessary, but a $300 to $600 up-front cost can save you in maintenance costs in the long term.
Old septic tank removal: If you’re replacing an existing tank, you’ll pay around $45 to $200 per hour for labor.
Landscaping: Land clearing prior to your septic system installation ranges from $1,200 to $4,800. Landscaping after often costs between $5 to $24 per square foot.
This table highlights how much various replacement parts for your septic tank can cost.
Replacement Parts
Average Price
Baffle
$250 – $400
Pump alarm
$500
Septic distribution box
$500 – $1,500
Sewer line or sewer pipe
$50 – $250 per linear foot
Tank lid replacement
$30 – $70
Pump replacement
$800 – $1,400
What Are the Benefits of Septic Tanks?
Septic tanks are necessary if you live in a rural area, but they also come with their own benefits.
Low maintenance: Septic tanks only need to be pumped every three to five years to remove accumulated solids. Schedule regular inspections to make sure your system is in good working condition.
Onsite water treatment: Your septic system and drain field release treated water to the groundwater so the soil isn’t contaminated.
Environmentally friendly: Sometimes, sewer lines can leak and contaminate groundwater. Septic systems connect directly only to your home, which means less strain and less deterioration over time.
Professional Vs. DIY Septic Tank Installation
I don’t recommend installing a septic tank yourself. It’s a complex system that’s connected to nearly every major plumbing component in your home. Mistakes can lead to sewer backups, groundwater contamination, and thousands of dollars in repairs. In addition, you need major equipment to excavate the hole where the tank resides. It’s best to leave this project to the professionals.
To find the right contractor or plumber for septic system maintenance or installation, follow these steps:
Research experts. Find local contractors or plumbers, compare their reviews, and investigate their experience with septic tank installation. Professionals should also have the appropriate licenses and insurance policies for your area.
Ask for recommendations. As you start to contact professionals, ask about their recommendations for septic systems based on your needs and budget. Discuss your area’s requirements, including soil tests, minimum tank sizes, and permits.
Get three quotes. Gather at least three quotes from plumbers and contractors. Compare what’s included in the price, and read over any contracts.
Schedule your installation. Installing a new septic tank usually takes only five to seven days, but the entire process—from soil testing to inspections—can take up to eight weeks.
Ready to install or replace your septic system? Use the tool below to connect with a septic tank installer near you:
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If you live in a rural area, you likely need a septic tank. In most cases, connecting to your city’s sewer lines is more expensive than installing a new septic system. You also won’t be on the hook for monthly sewage bills.
However, homeowners need to adjust their habits in order to not overload the system, and some homes might not have enough dedicated space. In addition, maintenance and repair costs can add up over time.
To determine if a septic tank is right for you, discuss your needs and budget with a professional contractor or plumber. They can provide advice on the best types to meet your unique requirements.
FAQs About Septic Tank Installation Cost
What is the cheapest septic tank to install?
The least expensive septic tank to install is a traditional anaerobic septic system. Unlike aerobic or alternative septic system types that cost up to $20,000, anaerobic systems cost an average of $3,000 to $8,000, including parts and installation.
However, certain factors can increase your total bill. For example, a fiberglass tank will likely cost more than plastic or concrete, and a larger tank size will cost more than a smaller one. You may also have to pay extra for additional requirements, such as a land survey, land excavation and clearing, percolation test, building permits, riser installation, sewer lines, and landscaping. If you’re replacing an old tank, it needs to be removed, which adds $45 to $200 per hour for the labor.
If possible, it’s usually much more cost-effective to repair a septic tank than it is to replace it. A tank lid replacement often costs $30 to $70. Even a new pump costs less than a brand-new system—between $800 and $1,400 on average.
Only put approved items down the drain. Flushing baby wipes, cigarettes, or coffee grounds can clog the system. Household chemicals, pains, and oils can kill the bacteria that treat the wastewater. Never pour fats or grease down the drain, even if you have a garbage disposal, or it could affect your drain field.
Monitor water use. Too much water at once strains the septic system. Try to avoid using too many appliances that use water at the same time. Install high-efficiency plumbing fixtures, and fix leaks right away.
Keep your drain field clear. Don’t park cars or heavy equipment on your drain field. Trees’ roots can also cause the field to fail.
Schedule inspections and pumps. Have your septic system inspected and pumped every three to five years at a minimum.
If you notice wastewater backing up into the home, a strong odor from the septic tank or drain field, or there’s bright green, spongy grass on the drain field, call a plumber right away. These signs indicate there’s something wrong with the system.
How do I determine the best septic tank replacement size for my home?
To choose the best size for your new septic tank system, you need to consider average daily water usage and the number of people, bathrooms, bedrooms, and plumbing fixtures in your home. If you’re not sure what size you should install, consult with a plumber or septic tank contractor.
In most of the United States, laws dictate that a septic tank must be at least 1,000 gallons. For a home with one to two bedrooms, a 750-gallon tank is usually sufficient, as long as it’s legally allowed. A home with six to seven bedrooms likely needs a 1,500-gallon septic tank.
The smaller the tank, the more often you’ll need to pump it (every three to five years). If you opt for a septic system that’s too small for your home, you’ll need to pump it every year or even twice a year.
Your septic tank size requirements can change over time. If you add more water-using appliances to your home, your current system may not be large enough to handle the demand. This can result in overflows, sewage backups, pipe leaks, and system failures. In these cases, homeowners should consider upgrading their septic tank system or installing another small tank next to the existing one.
Hilary Cairns is a writer with 12 years of professional writing experience. She has covered a diverse set of topics such as custom home building, plumbing, HVAC, energy efficiency, and others.
A graduate of SUNY New Paltz with a bachelor's degree in English and a concentration in Creative Writing, she discovered her passion for helping businesses and organizations deliver impactful content that changed lives.
Originally from New York, Hilary now calls Florida home (along with 2 cats). When not immersed in her writing work, she enjoys playing video games, reading Stephen King, and researching her (and her friends') genealogy.
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.
Our editorial team is committed to creating independent and objective content focused on helping our readers make informed decisions. To help support these efforts we receive compensation from companies that advertise with us.
The compensation we receive from these companies may impact how and where products appear on this site. This compensation does not influence the recommendations or advice our editorial team provides within our content. We do not include all companies, products or offers that may be available.
