How Much Does a Septic Tank Installation Cost?

Septic tanks and septic systems are essential to properly remove waste from your home’s bathroom, kitchen, and shower. Although many existing homes are connected to municipal sewer lines, you’ll need to install a new system for a new home. Some homeowners may need to update their septic system after experiencing septic issues. The national average for septic tank installation ranges from $3,472–$11,102 but can reach above $21,000 on the high end.* 

*Cost data sourced from Angi and Home Advisor

Fortunately, septic systems are common. Jim Fuson, owner of 21st Century Home Inspections, says 25% of homes in the United States have septic systems. Unfortunately, installing or replacing them can be costly.  This article covers the types of septic systems available to homeowners, their costs, and the best ways to prepare for an installation.

The average price for a septic tank installation falls around $7,052. Final costs vary greatly based on home size and other key factors outlined below. 

• Tank type: More complicated systems cost more money than simple options. Some types of septic systems require a large amount of operating space which increases your installation costs. 
• Tank material: Investing in more durable materials increases your project costs but results in a longer-lasting system. 
• Tank size: Your septic tank’s size must match your home’s size. Bigger homes require larger tanks to provide adequate drainage.
• Labor: Complex septic tank systems require additional installation fees and labor costs.

Your chosen type of septic tank will depend on your available space, climate, house size, and soil types. Below is an overview of each septic tank system and their estimated costs.  

Septic Tank Costs by Type

Conventional Septic System

A conventional septic system uses gravity to move household sewage into the septic tank. Sewage is separated into layers, with solid waste settling at the bottom and liquid sewage rising to the top.

When liquid sewage rises to the level of the outflow pipe, the liquid waste flows into the drain field where it decomposes further. The drain (or leach) field is the permeable soil surrounding the tank that absorbs and naturally treats liquid residue. This prevents the contamination of contaminate runoff water or leaks into the water table.

Conventional septic systems are usually the most affordable, costing around $2,000–$7,000.

Anaerobic Septic System

The anaerobic septic system uses anaerobic bacteria to break down waste in the septic tank. These systems don’t require additional chemicals or power and are an affordable option for homeowners.

However, anaerobic systems don’t clean the tank and require a larger drain field to work correctly. If you have the space to accommodate a large drain field, an anaerobic system could be a viable option for your property. Additional costs for installing the installation or a drain field will also add to the final price of this installation. These systems will cost $3,000–$8,000 on average. The added size increases the average cost to $3,000 to $8,000.

Alternative Septic System

An alternative septic system collects sewage the same way as a conventional system, but it breaks down the tank’s sewage using oxygen instead of naturally occurring bacteria. Homeowners with limited yard space or looking for more compact options should consider alternative septic systems. These systems are also used with a high water table, poor soil, or high bedrock. 

Drain fields for alternative systems generally need less land and release cleaner wastewater. This benefit comes at an increased cost, with systems usually priced around $4,000–$15,000.

The following types of alternative septic systems are available for homeowners:

• Chambered septic system: Replacing the need for a gravel/stone system, chambered systems use gravelless drain fields with leaching chambers for filtration. They are ideal in areas with high groundwater tables or limited gravel. The gravelless chamber septic system typically costs $4,000–$10,000.
• Constructed wetland septic system: Similar to the natural process in real wetlands, this system cleanses wastewater using bacteria, microbes, and plants. The waste then helps those plants to thrive. This design is the most eco-friendly septic system available. You should budget between $7,500 and $15,000 for this septic system type.
• Drip distribution septic system: Drip systems are made to “irrigate” septic water over a larger area using long tubing throughout the leach field. Homeowners will need ample space and power for this type of system. These systems range between $4,000 and $10,000 on average. 
• Evapotranspiration septic system: These systems use a large open-air tank to allow the effluent, or liquid waste, to evaporate naturally. This type of system works best in climates that receive abundant sunlight and heat. Evapotranspiration septic systems cost $10,000–$15,000. 
• Pressurized distribution septic system: This system uses pressure to distribute effluent evenly. It can be paired with other septic systems that focus on water treatment. The pressurized septic system, which works well with a high water table, costs about $6,500–$9,000.

Engineered Septic System

Engineered septic systems are the most complex. They are generally needed due to poor soil or because the home resides on an uphill slope. Similar to alternative and conventional septic systems, engineered systems collect and separate waste in a tank. Instead of relying on gravity to drain, the liquid waste needs to be pumped into the leach field to distribute throughout the land evenly. 

These systems have the highest price tag because they require more moving parts and specialty equipment. These systems generally cost $7,000–$20,000.

Below are some examples of engineered septic systems:

• Mound septic system: Mound systems use mounds of sand to clean wastewater instead of a typical leaching field. These systems require the installation of sand and a pump tank, which increases the installation cost from $10,000–$20,000. 
• Aerobic system: By pumping oxygen into the treatment tank, these systems generate naturally occurring bacteria to process the waste. If you prefer an aerobic septic system, you can expect to pay around $11,000–$19,000.
• Recirculating sand filter system: This septic system uses sand to filter effluent out after leaving the pump tank. The treated water then flows to the drain field. Sand filter septic systems work best in areas near bodies of water or with a high water table. You should budget $6,000–$10,000 for your project.

Material costs impact the final price of your septic tank. More durable materials have a longer life span but a higher price tag. If you live in an older home, you may have a steel septic tank. If so, you should consider replacing it with a more resilient material. 

Below are the most common material types available for your home: 

• Concrete: Concrete septic tanks are durable and rust-proof but are hard to repair if damaged. Depending on the size, concrete tanks may cost around $700–$2,000. 
• Fiberglass: Fiberglass septic tanks are stronger than their plastic counterparts but can be shifted or displaced if the water table rises too high. These tanks are priced between $1,200–$2,000.
• Plastic: Plastic septic tanks are cost-effective but prone to damage. They cost around $500–$2,500.

Some homeowners may have steel septic tanks installed in their homes. Although steel is considered a durable material, steel tanks are not used in newer installations since they are prone to rust over time. These tanks are usually found in older installations and should be replaced with a newer option when they deteriorate.

Septic Tank Cost by Material

Your septic tank size ties directly to the number of bedrooms in your home. The more bedrooms your home has, the larger your septic tank must be. For example, a 1,000-gallon tank would cover a three-bedroom house home and cost about $1,500 on average. However, a one-bedroom house home could use only a 500-gallon tank, reducing the tank cost to around $800.

Recommended Tank Size by House Size

Labor costs must be factored into your project. Some septic system types require a large amount of space or a complex installation. Typically, you hire a plumber or other specialist to replace or install a septic tank. Depending on the project’s complexity, labor costs could fall between $1,500 and $4,000.

Additional cost factors, such as permits, soil testing, and ongoing maintenance, impact your investment in a new septic system. We’ll cover these added costs below. 

Maintenance

Your septic tank will require regular maintenance to keep it running smoothly. According to the U.S. Environmental Protection Agency (EPA), homeowners should have their septic system checked and pumped every three to five years by a professional. Cleaning costs range between $400–$1,000 on average. 

Percolation Tests

Depending on the size of the land and soil conditions, a percolation test can cost anywhere from $250–$1,000. This soil testing is required, and you must plan for these costs. Typically, professionals only dig a few holes in the proposed leach field area, but your test’s cost can increase if a land survey is needed to determine where to excavate.

Permits

To build a septic tank on your land, you’ll need to obtain a permit. Permit pricing varies from state to state, but they usually cost $200–$2,000 and are typically renewed every few years.

Although the average lifespan of a septic tank is about 20 to 30 years, your system will have normal wear and tear of its components over time. Most septic tank systems have parts that are independent of each other, making replacements a simple process.

Below are some common septic tank components that may need to be replaced or repaired over time:

• Access risers: For septic tanks buried far into the ground, access risers help the lid rise to the surface. For these replacements, expect to pay about $350–$800.
• Baffle: The baffle is essential in directing the wastewater through the septic tank for proper removal. It can be replaced for $250–$400.
• Leach field: These are one of the most expensive replacements in a septic tank system. Homeowners can expect to pay $4,000–$15,000.
• Tank lid: Lids may naturally crack over time with continued tank use. Although the replacement part costs between $50 and $120, opting for a professional installation will increase the total from $100–$300.
• Tank pump: Not all systems will require a tank pump. However, if you do need a replacement, you can expect to pay $600–$1,500.

Homeowners should also consider a septic tank warranty to cover their system when it’s time for repairs. Individual component replacements will cost much less than replacing your entire system.

Septic tank installation is not recommended for do-it-yourself homeowners due to its complexity. You’d need extensive knowledge of sewer systems and plumbing to properly install a tank. Homeowners would also need professional machinery to perform the tank excavation and drain field installation. Improper installations could lead to sewer backups and groundwater contamination. 

We recommend hiring a licensed septic tank installer or plumber to complete the installation.

To ensure septic tank installation goes smoothly, here are a few tips to keep in mind.

Receive Multiple Estimates

Before any excavation or signed paperwork, receive estimates from licensed septic tank installers and read reviews about each company using trusted, third-party consumer reviews. Ensure the contractor you select holds the proper insurance and licensing and includes necessary preparations like excavation and drain field testing in their estimate.

Test the Soil and Obtain a Permit

Before installing a septic tank, you’re legally obligated to obtain a percolation or “perc” test. This test confirms the soil meets requirements set by the city and local health department. Usually, the soil is required to have adequate amounts of permeable contents like sand or gravel. Once the land passes the percolation test, you can obtain a permit and start the installation process.

Note: If you want to put a septic tank on a piece of land, it must pass the percolation test. We recommend ordering a test before purchasing the land you want to use for residential purposes.

Plan for Excavation

Heavy equipment is needed to excavate the large amount of land necessary for a septic tank. Make sure to budget landscaping costs to fix any damage incurred during excavation.

If you’re building a new home, schedule the excavation at a time when it’ll have minimal impact on the construction process. Typically, this is before paving the driveways and sidewalks, but after the home’s main frame is built.

Whether planning a new installation or replacing your current tank, it’s crucial to select a system that will work with your household size, climate, and local environment. Although DIY septic tank installations are possible, we do not recommend them unless you have professional experience. Instead, you should consult a professional installer to complete your job. Research at least three installers in your area and compare the quotes, available equipment, labor costs, and warranty options.

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