How Much Does a Septic System Cost?

How Much Does a Septic System Cost?



Several factors go into the pricing of a new or replacement septic system. But to give you a quick snapshot of the average cost, we used a three bedroom home, the standard size in the United States. For a home of this size, the typical tank is 1,250 gallons.

The Short Answer

  • Aerobic: $10,000 – $20,000
  • Anaerobic: $3,000 – $8,000
  • Mound: $10,000 – $20,000
  • Other Alternative Systems: $5,000 – $18,000

The average cost, including installation labor and the tank itself, varies between $2,000 and $10,000, though it can be as high as $15,000. If you live in a modest size home, expect to spend close to the national average of $6,000.

FAQ About Septic Tanks

1. Can you install your own septic tank?

Short answer: No. While it is technically possible for you to install your own septic tank, the odds are very high that you’ll make a mistake that will cause you much more grief (and cost you much more money) than working with a professional in the first place.Installing a septic tank requires specialized technical knowledge you can’t gain from a DIY YouTube video. Messing up this project could cause water pollution, drive up your home insurance premiums, and make your home much harder to sell. In some places, it may even be illegal for someone without the proper license to install a septic system.

2. How do septic tanks work?

Different types of septic systems work in different specific ways, as we’ve already covered. But these are the basics. Waste from your home (anything that goes down the drain of toilets, sinks, showers, etc.) flows into the septic tank. In the tank, waste separates into three layers: the scum layer on top, liquid waste in the middle, and solid waste sinking to the bottom. Either aerobic or anaerobic bacteria break down the solid waste, which stays in the tank. Liquid waste goes through the filter before moving on to the leach field, which distributes the water into the ground in most systems. 

3. How can you tell when you need a new septic system? There are a few signs to look for that will tell you it’s time for a new septic system, or at least a repair. Signs include: — Standing water in the yard — Sewage smells — Showers, sinks, etc., in the home draining slowly  — Water and/or sewage backing up in toilets, showers, sinks, etc.

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Septic System Replacement Cost

It’s normal for pieces of a septic system to age and wear over time. System maintenance is usually cheaper than installing a new system because design and excavation are already done. Additionally, most systems have fairly independent pieces that are easy to replace, such as tank lids or filters.

Signs that your tank needs to be replaced include noticeable cracks or damage, unusually strong smells of sewage, standing water, slow sink/shower draining and toilet flushing, patchy grass, or contamination in nearby water sources. Remember, the average lifespan of this system is 20 to 30 years. If yours is several decades old, it may need to be replaced. If you have increased your house size substantially and added new bathrooms, you may need a bigger tank. The average tank removal cost is $5,000 to $6,000.

You can replace the tank baffle ($300 to $900), tank lid ($150 to $500), and tank filter ($200 to $300). If the tank pump fails, it costs typically between $200 and $500. Replacing the leach field is more expensive, costing between $2,000 and $20,000. Hiring a specialist for the replacement is usually between $125 and $175 per hour. The hourly rate may vary based on area, but it should be fairly consistent for any type of septic installation or repair.

Types of Septic Tank Systems

The total cost of installing or replacing your septic tank is largely dependent on the type of system you choose. Here are some of the most common kinds of tanks:

Anaerobic Septic System

Anaerobic systems are a common choice for many homeowners because they don’t require additional power or chemicals. An anaerobic system contains bacteria that do not need oxygen to survive. The bacteria break down solid waste and the remaining liquid waste is piped out and distributed under the soil. The waste is naturally recycled as the water passes into the soil.

These systems cost about $2,000 to $5,000 to install.

Aerobic Septic System

Unlike anaerobic systems, aerobic systems use bacteria that do require oxygen to survive. Oxygen is pumped into the tank to activate the bacteria, which then feed on solid waste. Aerobic systems work well where the soil isn’t favorable for other systems and the groundwater table is high. It’s a good option for homes located near a body of water.

Aerobic systems are more expensive to install. Expect to pay between $10,000 and $20,000.

Gravity Septic System

A gravity septic system uses gravity for filtration and water flow. They need to be installed on a gentle slope to enable water flow without a pump.

Installation costs $1,500 to $4,000.

Conventional Septic System

The conventional septic system consists of a septic tank and a trench that acts as a drain field. The trench is constructed on stone or gravel and allows water to pass through. To prevent sand or dirt from contaminating the clean soil, geofabric is installed on top of the trench. A conventional septic system needs a large space to operate.

These systems cost between $2,000 and $5,000 to install.

Mound Septic System

If your groundwater is close to the surface, a mound septic system is the best choice. A sand mound is constructed on the septic system area to pump wastewater from the tank into the mound in small quantities. The sand then filters the water before it gets into the soil and groundwater. This design requires a lot of space.

They’re also expensive to install because a sand mound has to be constructed. Total cost ranges from $10,000 to $20,000.

Chamber Septic System

Chamber septic systems have recently become a popular choice. They’re similar to conventional systems, except plastic chambers are used in the drain field instead of gravel. These are easier to construct and have a smaller carbon footprint.

They cost $1,500 to $5,000 to install.

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?

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.

Septic vs Sewer Cost

A septic system costs $3,100 to $9,600 to install while connecting to a main sewer line can be slightly more affordable, around $1,500 to $8,000. Think of this system as your own personal sewage system. A septic system treats wastewater on site, with an underground tank and pipe system on your property. If your home plumbing system is not hooked up to a septic system, it is connected to the main city sewer line. Sewage connections carry the wastewater from your home and route it underground to a city or county treatment plant.

SystemCost (Installed)Sewer$1,500 - $8,000Septic$3

SystemCost (Installed)
Sewer$1,500 – $8,000
Septic$3,100 – $9,600

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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Extra Services

Now you should have a detailed estimate of how much you would pay for a new septic tank or whole new septic system for your home. But don’t stop there. If you want to know how much you’ll really spend on this project, there are some related services you’ll need to take into account. 

For one, you may need to prepare your property in some way before it’s ready for the installation of your septic tank. For another, you’ll definitely spend more money over the years maintaining your septic tank with regular pumping and cleaning and the occasional part replacement. 

Part replacements

If you have a problem with your septic system somewhere down the line, don’t panic. Most of the time, replacing a single part will solve your issue quickly and easily. You likely won’t have to replace the whole system or the tank itself for a few decades. 

Keep in mind, even though replacing a small part might seem easy, it’s still a good idea to hire a professional. As with installation, even a minor error can cause major problems that could be expensive to reverse. 

Tank lid$45 – $112
Baffle(s)$23 – $500
Filter$230 – $280
Riser$300 – $600
Pump$620 – $1,300
Leach field$3,375 – $12,000

Regular maintenance

Photo Credit: SuSanA Secretariat / Flickr / CC BY
Photo Credit: SuSanA Secretariat / Flickr / CC BY 2.0

For your septic system to perform to the best of its abilities for as long as possible, the tank will need regular pumping and cleaning. Experts recommend hiring a plumber (or other specialist) about every three to five years to pump your septic tank. On national average, you can expect to pay a pro $294 to $563 for pumping and cleaning. This preventative expense is much less than you would spend repairing a malfunctioning septic system. 

Percolation test cost

Before you install your septic system, you’ll need to get a percolation test from a qualified engineer to figure out the type of soil your installer will be dealing with and the height of the layers in the ground (water table, bedrock, etc). The results of the perc test will determine which type of system would be best for your property. 

Your septic tank installer might be able to conduct the perc test for you, or you may need to hire a separate professional. Either way, expect to pay between $670 and $1,430 for the test.

Land clearing cost

Photo Credit: / Flickr / CC BY-
Photo Credit: / Flickr / CC BY-ND 2.0

Especially on a new construction site, you may need to remove obstacles such as trees and bushes before the installers can break ground on your septic tank project. This job involves excavation and requires a lot of open space, so you may need quite a few obstructions removed. 

More often than not, you’ll need to hire a separate land clearing company to prep the area for your septic tank installation. Clearing a large space usually costs between $1,210 and $4,820.

Landscaping costs

It’s safe to assume that you won’t be happy with the appearance of your yard once your septic system is complete (unless you’re a fan of barren dirt lots). So, after installation, you may want to hire a professional landscaper to cover the site with more aesthetically appealing scenery. 

Landscaping costs are highly subjective because the umbrella term “landscaping” covers so many different services. For example, installing a new flagstone walkway will cost a lot more than planting a few bushes. In general, you can expect to spend $5 to $24 per square foot for professional landscaping, depending on the complexity of the landscape design.

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Septic Tank Cost: Replacement Parts

As with any mechanical system, issues are bound to arise. Septic tanks that are properly cleaned and maintained can last an average of 20 to 40 years. While some of the problems with septic tank systems are easy to solve, others will require significant assistance from a professional. From baffles to tank lids, these are the most common parts of a septic tank that may need to be replaced or repaired.

Baffle Replacement

Baffles are designed to help prevent scum from clogging inlets and pipes. Baffles that fail or get clogged are a common issue, and replacing them is usually much cheaper than replacing the entire tank. Replacement costs range between $300 and $500 including labor.

Septic Tank Pump Replacement

For septic tanks that require a pump to push the effluent from the tank to the drain field, it’s possible that the pump may fail to do the job properly. The average cost to replace a failed pump ranges between $800 and $1,400 including labor.


Tank Lid Replacement

A broken or rusted lid is a minor repair that costs between $30 and $70 before labor. Metal lids are the easiest to replace if they have rusted over, while a concrete lid may require some special equipment to remove and install the new lid.

Septic Tank Filter Replacement

Replacing a septic tank filter is the most common issue for most homeowners. The cost to have a replacement filter installed on a septic tank averages between $230 and $280.

Septic Drain Field Replacement

If a septic tank leach field or drain field becomes oversaturated, sewage can back up into the house. The average cost to dig out the existing drain field and install a new one runs $7,000.

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 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.

What are the maintenance costs that add up for the septic system cost?

The septic system cost when you replace it is costly, but you can prevent future issues and catch problems early on with regular maintenance.

One of the biggest maintenance tasks related to septic systems is pumping. Over time, sediment and other materials build up in the bottom of your system. This material, called sludge, can’t travel through the pipes and created a thick coat in your tank. The more sludge in your tank, the less wastewater it can hold and the sludge will eventually block the pipes. By pumping your septic tank frequently, you can remove this sludge and keep everything moving. 

Septic tanks need to be pumped every three to five years. This costs about $400 on average. Pumping large tanks can cost $1,000 or more. If you have a small septic tank or a large family (that requires more wastewater) then you will likely need to pump your septic tank more frequently.  

Along with pumping every five years, you should schedule an inspection every one to three years. The inspector will check the sludge levels and check for issues with the system to see if repairs are needed.  

Before you balk at the cost of having a septic tank pumped, think about what could happen if you don’t maintain it. Not only will it cost thousands of dollars to replace it, but you could end up with sewage in undesirable places. You could experience backups in your toilets and sinks or have to contend with foul odors around your home and yard. 

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Ground Preparation

While the drain field can be expensive, it is an important part of the system. Another important element is ground preparation. You will need to clear the land, dig up the earth, and move or remove it. This costs an average of about $1,000 for a standard property and an average septic system.

Cost Factors To Put In A Septic System

The average cost to put in a new septic system is $3,280 to $9,550. A basic septic system for a 3-bedroom home will cost $3,918 on average with most homeowners spending between $3,280 and $5,040. When you install a system with two alternating pumps, expect to spend $9,500 to $15,000.

Cost To Put In A Septic System
Installation Items Head Average Cost
Basic Quality – Including fiberglass basin, pump, installation from the septic tank or sewer line, 40′ pipe run, and automatic float switch (no electric work or pipe included) To 15’ head $3,280
To 25’ head $3,880
To 30’ head $5,040
Higher Quality – With two alternating pumps, 700- to 800-gallon concrete or fiberglass basin, automatic float switch, indoor control panel, high water or pump failure alarm, explosion proof electrical system but no electric work or pipe Per pump system $9,950

Cost Factors To Install

Cost Factors To Install

Installing a septic system is expensive because of the amount of labor involved in doing it correctly. From start to finish, the entire project could take up to three weeks or longer, depending on the permit processing and the complexity of the system you need for your property.

  • Soil testing – A deep hole percolation test by a qualified engineer costs at least $1,000 but ranges between $1,000 to $2,000. Testing will reveal the type of soil in the area and what depths the different layers are at; how deep each layer is; and with the combination of layers, how well suited the area is to filter and drain from the system. Positive results from the survey and test will also allow you to get approval for the drain field (also called leach fields or leach drains).
  • System design – The design of the septic system will generally take between 2–3 weeks to design and cost an average of $600, depending on your location and the complexity of the system. Use the same engineer to do both the percolation test and the system design, as he/she might not accept the test results from the percolation test if done by someone else.
  • Clear the landLand clearing costs around $950 on a quarter-acre for light clearing on flat ground without rocks.
  • Install and connect pipes and tank – To take wastewater from the house to the septic tank costs $25 to $33 per linear foot for excavation, installation, and backfill; and an average of $1,000 to $1,500 for the tank.
  • Leach Field – A drain or leach field costs $3,000 to $15,000. Lay the filtration materials or leach field – $9–$12 per linear foot. Add $25–$33 per linear foot of vitrified clay pipe from the house to the septic tank.
  • Inspection and testing – Pass all checks and final inspection and testing – Building permits cost about $250 to $450, and your local health department will determine which permits are required.
  • Pump Alarm – Add $720 for a high-water or pump failure alarm. Other add-ons and septic tank repairs cost $600 to $3,000 on average.
  • Landscaping costs – Include the costs of any landscaping needed once the tank is installed and dirt has been backfilled over it.

Cost to Install a Septic System Leach Field

The average cost to install a septic system drain or leach field is $3,000 to $15,000. Septic sewer drain fields or leach lines are built with unsaturated paper, piping, and gravel. The fields are excavated, and 4 PVC pipe is laid in 3′ deep by 1′ wide trenches, after which it’s backfilled, and excess soil is disposed of properly.

  • With 12″ gravel base – $30/LF
  • With 24″ gravel base – $11/LF
  • With 36″ gravel base – $30/LF
  • Add for pipe laid 6′ deep – $20/LF

Septic System Permit Cost

Septic System Permit Cost

You’ll need your permit from local authorities allowing construction of your new septic system. Expect to pay about $250–$450. It’s usually required to need a site plan: a scale diagram of your land which details the location of the house, outdoor elements (like a detached garage, any walkways, any swimming pools), and the location of the septic system. You can apply for the permit yourself, or your local contractor can include this in the quote. On average the permit will take about 1–2 weeks to secure, and costs include the inspection during construction and after this work is complete.

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