How much does it cost to install a septic tank?

Factors for cost

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Septic tank replacement price is guided by construction material, the extent of the work required to dig out and then refit a new unit, and some other elements.

Septic tank fabrication

HomeGuide reports that the material used to build the tank plays a major role in the total cost. A 1,250-gallon concrete tank, for instance, will cost roughly $2,510, while a fiberglass tank of the same volume will come in a little cheaper at about $2,350.

Concrete is a great option for septic tank installation because it will last an exceedingly long time. Bob Vila reports that concrete tanks can last upwards of 40 years if maintained to a high standard, whereas other models will require replacement much sooner.

It’s also important to consider the function of your tank. An aerobic septic system will cost more than an anaerobic one because of the oxygen requirement and specialized features that support the inflow. HomeServe notes that anaerobic systems can cost between $10,000 and $20,000 to install and are often found in geographic areas where the water table is much higher.

Extent of wear and the potential for additional work requirements

An older septic system may require replacement as a result of leaks or other signs of deterioration. The more damage that a tank has sustained, the more likely it will be that you’ll need additional cleanup or site preparation to fit the new tank into your existing system.

Septic tanks foster a complex biological environment, and the wastewater that is filtered through the system must be handled with care. Cleaning a spill from the septic system is wholly unpleasant for any homeowner who uses this wastewater disposal setup. You can expect to pay a premium for removal and replacement if the tank has started to seep waste into the surrounding soil.

Labor costs

Septic tanks made of concrete are often too large and heavy for a homeowner to install on their own. These systems require special lifting equipment and often a team of experienced professionals to secure the tank in the correct position and then hook it into your existing wastewater infrastructure. HomeServe reports that installation costs typically range from $1,500 to $4,000 for a new septic tank.

For a fiberglass or polyethylene tank, it may be possible to install the new feature yourself, saving you on the installation. However, you’ll need to check with the guidelines laid out by your local authority before starting the process. Some communities require the hookup to be done by a licensed professional to avoid any leakages caused by improper installation (via Bob Vila).

Even if you are obligated to hire a professional to conduct the installation, you can still save on the total cost by digging the hole and preparing other aspects of the installation space rather than leaving the entire job to a contractor.


Cost to Install A Septic System for an RV

If you’re building a more permanent septic system for your RV, then prices are the same as installing one for a house at $3,300 and $5,000. An RV these days is generally understood to be a mobile vehicle. The septic system in an RV consists of a black water or wastewater tank, the contents of which are dumped into a sewer connection or dump station. It will need to be flushed, cleaned, and sanitized regularly to stay in good working order.

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Questions to Ask About Septic Tank Cost

A septic tank might not be a product that is familiar to a homeowner. Having a basic understanding of what owning a septic tank will entail is an important step to successful home maintenance. Whether you’re buying a home with an existing septic tank, or you’re building a home that will need a septic tank system, here are some helpful questions to ask.

  • What is the difference between a septic tank and a sewage system?
  • Will I smell raw sewage all the time if I install a septic tank in my backyard?
  • Why do I need to get a percolation test?
  • How much space do I need to reserve for a septic tank?
  • What’s the best size septic tank for my house?
  • How much will it cost?
  • Can I install one on my own?
  • Do I have to maintain it myself?
  • Can it be repaired?
  • How often do septic tanks need to be replaced?
  • Are there any best practices I should implement with my water usage in my home to prevent problems with my septic tank?
  • How often do I need to have my septic tank pumped?
  • What is the septic tank pumping cost near me?
  • Why does my septic tank seem to have problems when it rains?
  • Can septic tanks freeze?
  • Can I plant trees near my septic tank?
  • If I lose power, will my septic tank still work properly?


Depending on where you live and the complexity of your project, you may need a building permit. A permit may add several hundred — or even several thousand — dollars to the cost of your overall project, but it and its accompanying inspections will help ensure your tank is installed according to code.

Pros and Cons of a Septic Tank

The advantages of a septic tank outweigh the disadvantages for most homeowners. This project is a sizable investment, costing from $720 to $10,000, but it’s money well spent when you can dispose of waste in a safe, sanitary way. Septic systems also give homeowners independence and peace of mind knowing they can use their sinks, showers, tubs, and toilets without worrying about clogs and backups in a community sewage system.

Septic systems protect the environment by removing pollutants from surface water and replenishing groundwater. They protect your family’s health and the wider health of the community by reducing the risk of pollutant and pathogen transmission. On the downside, these systems may encounter problems, especially as they age. Damage to the tanks and other sections of the systems may require repairs. If the drain field overflows, you will also need to get that fixed. Even so, the maintenance requirements of a modern system are minimal, especially if it was properly installed by a professional.

Sewer Pipe Cost

Sewer pipes in septic systems are slightly different from the typical sewer pipe. They are a different size and usually are a minimum of 4 inches in diameter. These pipes have protection around them, such as baffles or sanitary tees typically constructed of concrete, fiberglass, or plastic, and need to be acid-resistant. The most common materials for sewer pipes for these systems are PVC and cast iron. The cost depends on the pipe length and location. The material cost of the pipe is between $100 and $240 per linear foot of material to replace or install a sewer pipe. The cost for a plumber to do the installation or repair is typically between $45 and $200 per hour.

Permits and Red Tape

Various tests will need to be undertaken before you can even consider having a septic tank installed. A deep hole percolation test, costing $1,500, determines the type of soil you have. A positive test means that you can have a standard leach field. A negative test means that you will have to have an above-ground or mound septic system, which will cost two or three times as much as a normal septic system.

Once the tank and system are fully installed, you will have to have them inspected. Permits cost approximately $300, with costs being determined by the area you live.

It’s also worth taking into account additional costs that might be incurred once the job is done. Expect to budget between $50 and $200 a year for maintenance, with pumping required every three to five years.

Finally, you may have to pay for landscaping and other work to make the area look good once the tank is installed and operational.

Image Credit: AuntSpray, Shutterstock
Image Credit: AuntSpray, Shutterstock

How much does it cost to replace a septic tank?

Expect to spend between $3,000 and $10,000 to replace the septic tank for a single-family home. However, this overall cost really depends on two other numbers: the price of your septic tank and the cost of installation.

Septic tank prices vary based on the type and size of the tank in question. The tank size you need is usually determined by the size of your household, so there’s not much choice there unless you want to go bigger to accommodate future growth.

On the other hand, you have more options when it comes to the type of tank you want:

  • Concrete tanks: A concrete tank can cost $700 to $2,000 before installation.
  • Fiberglass tanks: A fiberglass tank typically costs $1,200 to $2,000 before installation.
  • Polyethylene (plastic) tanks: A plastic tank is, on average, the most variable option at $500 to $2,500 before installation.

Steel tanks are also an option, but they’re less common and prone to rusting.

How to Prepare for Your Septic Tank 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

Septic systems rely on permeable soil surrounding the tank to absorb and naturally treat liquid residue so that it doesn’t contaminate runoff water or leak into the water table. This area is known as the drain or leach field.

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’ll be able to 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. If you currently reside on the land, 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 main frame of the home is built.

How does a septic tank system work?

Generally speaking, septic tanks function by separating floatable matter (like oil) and solids from your home’s wastewater before sending the remaining treated water out into either the soil, sand, organic matter, wetlands or other media. However, the specifics of how a given type of system works will differ.

In a conventional septic system, the grey water and blackwater from your home flow into the tank. Over time, the solids sink to the bottom of the tank, and fats, oils and grease float to the surface as scum. The scum and sludge are separated from the wastewater, and the treated water is sent to the drainfield for further filtration.

The drainfield removes harmful coliform bacteria and viruses as the wastewater gets sent through a filtration process involving sand, soil or other means. The wastewater is then continuously filtered as it passes through the earth before entering the water table.

What is a Septic System, and How Does it Work?

A septic system is an underground wastewater treatment structure most often used when a municipal sewer system is not available. They are commonly found in rural areas rather than cities.

A typical septic system consists of a septic tank, a distribution box, and a leach field. A leach field is also called a drain field or soil absorption field. A septic tank will help digest organic matter and separates floatable matter such as grease, oils, and solids from the wastewater.

The system discharges the liquid from the septic tanks into perforated pipes buried in a leech field, designed to release the effluent into the soil slowly.

Although the first septic tanks have been in use since the late 1800s, they did not become popular until the 1960s. Up until that time, a cesspool was common in most homes.

How Much Does It Cost to Install a Septic Tank?

On average, the cost of installing a new septic tank system is $3,900. The price ranges from $1,500 to $5,000 for a typical 1,250-gallon tank, which is an ideal size for a three- or four-bedroom home.

This cost is inclusive of the tank itself, which costs $600 to $2,100 or more, depending on the type. Labor costs are also included in the installation price, and usually range from $1,500 to $4,000.

Cost Factors to Install a Septic System

Cost considerations, in addition to the size and type of system you choose, also include:

  • Engineering — Septic systems require the input of an engineer at an average of $500–$650. Factors they consider when designing your system include:
  • Slope — conventional septic systems can’t be installed where land slopes more than 30 degrees.
  • Fill — native soil is required. The use of engineered fill may be prohibited or require a special permit.
  • Wetlands — drain fields can’t be designed to discharge into wetlands or waterways.
  • Drainage — how well your soil absorbs water — determined by soil testing — as well as external forces that could flood your system.

Plans for new systems cost the most and take up to three weeks to complete. You’ll pay a little less when replacing an existing system.

Soil Testing

To determine which type of septic system you need, engineers first do percolation, or perc, tests that show how well your soil absorbs liquid. New home sites may fail if it isn’t permeable enough to absorb discharge or if it’s so porous that water runs right through it before it’s adequately filtered.

Typical perc testing requires drilling two holes that simulate conditions for a septic system. It takes up to a day to do at an average price of $300–$1200. Costs depend on the complexity of the procedure based on local regulations.

So-called “deep hole” soil tests look at soil down to a depth of 10 feet to ensure there are no barriers to drainage such as rock or a high water table. Prices range from $900–$2000.

Permits and Inspections

Permits for septic tanks range from $50–$200. Most towns also require a post-installation inspection at the cost of $100–$200.

Land Clearing

An open area is required for both tank and drain field installation. For areas of a quarter-acre or less, expect to pay $800–$100 for light cleaning, including small tree and stump removal. Restoring your landscape to its original condition after installation adds $300–$600.

Septic System Upgrades

Upgrades to your septic system like these can make it more user- friendly:

  • Septic Tank Riser

Cleaning an underground septic tank requires digging a hole in your lawn unless it’s equipped with a riser. Risers are plastic or concrete extensions that sit atop the tank and offer easy access to the pumping port.

Not everyone wants a riser on their lawn — they’re not pretty — but they come highly recommended if you live in a harsh climate or hate the work of restoring sod after your tank is cleaned. Costs range from $70–$350 installed.

  • Tank Alarms

Select types of septic systems can be equipped with tank alarms. They work like floats in a toilet tank and can tell you if water has reached an unsafe level because of a blockage, allow you to alter your usage until the situation is corrected. Prices range from $85–$230 installed.

  • Lift Stations

If a septic tank is installed below the level of the drain field, a lift station can keep effluent flowing when gravity fails. Lift stations are pumps that kick in when water in the tank reaches a preset level. Installed, they add $2500–$5000 to the price of a system.

Building a Drain Field

The drain field is an integral part of the septic system. Also referred to as leach fields or leach drains, a drain field is a network of pipework where the separated waste is passed. The effluent trickles out of the pipes, through aggregate that is used to prevent flooding, and into the soil below. Here, the soil disposes of bacteria before the cleaned water is passed back into the water table. Expect to pay anywhere between $2,000 and $8,000 to have an effective drain field built as part of your system.

Image Credit: Slave SPB, Shutterstock
Image Credit: Slave SPB, Shutterstock

Additional Costs and Considerations

With the installation of any septic tank system, there are several up-front costs and considerations to take into account. Permits must be obtained, soil must be tested, land needs to be prepared, and more. On occasion, a septic tank may require removal, which would be an additional cost to consider. While these tasks may seem daunting, they are easily completed with the help of qualified professionals.

Landscape Preparation

Once the best location is found, homeowners can clear the landscaping in preparation for the installation themselves or utilize the help of the septic tank installation company. On average, landscape preparation cost can range between $1,200 and $4,500, but this is often built into the cost of installation at a lower rate.

Soil Testing

Homeowners must obtain a percolation test prior to installing a septic tank to make sure that the ground can accommodate the system and meet local health department requirements. Engineers drill a hole to test soil permeability and the layers of sediment. This costs approximately $1,000 to $2,000 to complete.

Permits and Inspections

Local permits can be obtained once the soil has been tested and the appropriate system has been chosen. The cost of permits is set by local city and health departments who check and inspect the soil and designs. For more significant construction, a building permit may be required and can cost between $400 and $2,500. (Some regions may have lower fees for septic tank permits.)


Leach Field

The septic system leach field is a critical element that must be built properly to avoid problems down the road. This often includes laying the pipework from the house as well. The cost of installing the leach field varies due to the size, soil content, and whether a special drainage system will have to be installed. The average cost is $2,000 to $10,000.


On average, the labor costs to use a professional company to install a septic tank system range between $1,500 and $4,000. This includes the labor, materials, and insurance the company carries. An average rate would be $160 per hour.

Septic Tank Removal

In the event that a septic tank needs to be completely removed or replaced, additional time and labor are required to complete the job safely. The tank must be emptied, dug out, removed, and properly and safely disposed of. The average cost to pump out a septic tank is $250 to $600, and the additional cost to remove and dump a septic tank is approximately $5,500.


DIY considerations

  • Quite plainly, septic tank installs are never going to be DIY. They require too many experts and formal approvals, and the best thing to do is seek bids and ensure you choose the right provider.

Septic Tank Costs for Installation

Once you pick out a type of septic system, material, size, and prepare the site, it’s time to figure out how installation will impact your septic tank cost. Depending on the system type, the installation costs can be high. Since you have to make every connection perfectly to reduce the chances of leaks and the grade of depth has to be exact, it’s a good idea to hire a professional. There are multiple steps to cover to ensure your system works and doesn’t fail on you. 

Hiring a professional can increase your septic tank cost by $1,500 to $4,000. This includes designing your system, filing your permits, excavating the site, and installation. For a professional to draw up a design, you’ll pay between $600 and $800. Your location will determine your contractor prices per hour, and they range between $150 and $200. A typical installation process without any major setbacks should take between two to give days and 16 to 40 hours from start to finish. 

You’ll also have to add soil testing to your septic tank cost, and your permits are another thing to think about. The permit cost will vary by area and municipality, but they usually fall below $1,000. A site inspection may also be necessary, but they’re usually free. 

There are several phases to the septic system installation. An inspection is the first step in the proces. This inspector will determine which design will work best for your space and if they need soil testing. The contractor will then design the system. Next, they’ll apply for all of the necessary permits. Once everything is good to go, they’ll start the installation process by starting to excavate the area. The entire installation process can take between two and five days from start to finish. When they get the system installed, an inspector will have to double-check it before they backfill the soil. Finally, they backfill it and finish the process. 

Labor will make up a decent portion of your septic system installation cost. The prices per hour will be area-specific, and this is why it’s important to get multiple estimates. Septic System Installation by David / CC BY-NC-ND 2.0

Labor Costs & Hiring a Septic Company

The average labor fees for professional septic system installation ranges from $1,500 to $3,000 depending on the size, and the materials (weight) of the tank. On an hourly basis for materials, insurance, and equipment rental and you’re looking at about $160/hour.

To work toward making a final selection on your contractor, create a list that contains the 3 to 5 home improvement contractors who match most of the requirements on your checklist. Try to find as many as possible who match the following criteria:

  • Have technicians with years of on-the-job experience
  • Offer a guarantee or warranty
  • Are A+ rated with the Better Business Bureau
  • Are bonded and insured
  • Have multiple great reviews online
  • Follow all local municipality laws and building codes and acquire the right permits before work begins.

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