Replacing and maintaining a septic tank is an important part of home ownership.
Read this guide to learn everything you need to know about the costs of replacing a septic tank, how to maintain a septic tank, and more.
How Much Does It Cost To Replace A Septic Tank?
Replacing a septic tank costs between $3,000 and $10,000. On the low end, expect to pay about $2,500, whereas a high-end septic tank can cost $15,000 or more.
On average, expect to pay about $4,000 for a new septic tank, including professional installation.
Septic Tank Cost by Tank Size
The larger the tank, the more the septic system will cost you. Larger tanks are, of course, more pricey than small tanks.
A 500 gallon tank costs between $500 and $1,000, a 1000 tank costs between $1,000 and $1,500, and a 2,000 tank costs between $3,000 and $4,000.
It is unlikely that you will need a tank that large for a residential home. Generally, home septic tanks range between 500 and 1,500 gallons.
| Septic Tank Size | Average Cost |
|---|---|
| 500 gallons | $500 – $1,000 |
| 750 gallons | $700 – $1,300 |
| 1,000 gallons | $1,000 – $1,500 |
| 1,200 gallons | $1,300 – $1,650 |
| 1,500 gallons | $1,500 – $2,200 |
| 2,000 gallons | $3,000 – $4,000 |
| 3,000 gallons | $4,500 – $6,500 |
| 5,000+ gallons | $8,000 – $15,000+ |
Septic Tank Cost by House Size
Like tank size, home size is another easy way to estimate how much a septic tank will cost. Larger homes require larger septic tanks. Rather than calculate the exact home size, an easy way to figure out how large your septic tank needs to be is by the number of bedrooms.
For example, a one bedroom house requires a septic tank that is 500 gallons, and costs between $500 and $1,000.
A home with three to four bedrooms will require a 1,000 gallon tank, and will cost between $1,000 and $1,500.
For larger homes or duplexes, the gallons required can range between $1,500 and over $5,000, depending on the size. The price will vary accordingly.
| House Size | Septic Tank Cost |
|---|---|
| 1 Bedroom Home | $500 – $1,000 |
| 2 Bedroom Home | $700 – $1,300 |
| 3-4 Bedroom Home | $1,000 – $1,500 |
| 5-6 Bedroom Home | $1,300 – $1,650 |
| 6-7 Bedroom Home or Small Duplex | $1,500 – $2,200 |
| Duplex or Small Apartment Building (under fourteen occupants) | $3,000 – $4,000 |
| Small to Medium Size Apartment Building | $4,500 – $6,500 |
| Large Apartment Building or Shared Community Tank | $8,000 – $15,000+ |
Septic Tank Cost by Tank Type
There are several different types of septic tanks, each with their one features and price points.
Price-wise, all options cost roughly equivalent amounts, although fiberglass is slightly more expensive than other options such as concrete.
| Septic Tank Material | Average Cost |
|---|---|
| Concrete Tank | $700 – $2,000 |
| Plastic or Polyurethane Tank | $800 – $2,2000 |
| Fiberglass Tank | $1,000 – $2,300 |
| Steel Tank | $600 -$2,500 |
Concrete Septic Tank
Concrete is the most common septic tank material, and costs between $700 and $2,000 on average. Concrete septic tanks will last for a few decades, and are relatively durable.
However, concrete tanks can be susceptible to cracking or separation issues. Concrete septic tanks must be inspected every one to three years to look for cracks or other damage.
This will prolong the lifespan of a concrete septic tank significantly.
Plastic or Polyurethane Septic Tank
Plastic and polyurethane septic tanks have several advantages. For one, they rarely will crack like concrete septic tanks, which reduces the need for regular inspections.
Another advantage of plastic and polyurethane tanks is that they are comparatively lightweight, making them easier to install.
However, because they are so lightweight they can be susceptible to damage during the installation process. Also, plastic can crack or break under pressure or if soil conditions change.
Plastic and polyurethane tanks are not approved for use in every state, so be sure to check with your contractor to find out whether plastic or polyurethane tanks are an option.
Expect to pay between $800 and $2,2000 on average for a plastic or polyurethane tank.
Fiberglass Septic Tank
Fiberglass septic tanks are advantageous because they do not crack or rust. However, like plastic and polyurethane tanks, fiberglass tanks can become more easily damaged during the installation process.
Because fiberglass is a light material, installation can cost as much as 30% less than installing a concrete tank. Unfortunately, fiberglass septic tanks are also more likely to shift in the soil, because of how lightweight they are.
Fiberglass septic tanks cost between $1,000 and $2,300, not including installation.
Steel Septic Tank
Steel is a very uncommon septic tank material because of its susceptibility to rust and corrosion. Steel is frequently prohibited by local building codes, so they are used less and less.
It is likely not a good idea to install a new steel septic tank; they are usually only found in existing installations from decades ago.
A steel septic tank varies widely in price between $600 and $2,500.
Installation Cost of a Septic Tank
Labor costs make up between 50% and 70% of the total cost of installing a septic tank. Generally speaking, the labor cost of installing a septic tank will be more expensive than the price of the septic tank itself.
The labor cost will vary slightly by region. Areas that have higher costs of living will have higher labor costs than other regions, so installing a septic tank in the Northeast or West Coast will be more pricey than other regions.
Some septic tank materials are cheaper to install than others because they are lightweight.
Fiberglass, plastic, and polyurethane are all cheaper to install than a concrete septic tank, which makes them cheaper overall despite the fact that the tank itself costs slightly more.
Cost to Replace An Old Septic Tank
There are several factors that come into play when considering the costs of replacing a septic tank, such as replacing the tank lid, the tank filter, the tank pump, and more.
The most expensive aspect of a septic tank replacement is a drain field replacement, which costs between $3,500 and $10,000.
Other aspects are very cheap in comparison, some of them even costing under $50.
| Item | Replacement Cost |
|---|---|
| Tank Removal | $5,500 |
| Drain Field Replacement | $3,500 – $10,000 |
| Tank Filter Replacement | $250 – $275 |
| Tank Pump Replacement | $500 – $1,200 |
| Tank Lid Replacement | $30 – $70 |
| Tank Baffle Replacement | $25 – $50 |
Septic Tank Removal
Removing a tank is one of the primary parts of septic tank replacement. The cost includes pumping the tank first and then removing it.
The exact cost will vary depending on local labor costs, distance from the dumping ground, local dumping ground fees, what type of tank you have (lighter materials like fiberglass and plastic will be easier to remove), and tank size.
Cost of Drain Field Replacement
Septic drain or leach fields are the most expensive parts of the septic system to replace. If the drain field is overwhelmed with too much liquid it may flood and block up toilets and sinks.
The best way to calculate how much it will cost to replace the drain field is by figuring out its linear footage.
Digging up the drain field costs $30 per linear foot, and installing the new filtration or leach system will cost between $10 and $20 per linear foot.
Tank Filter Replacement Cost
Filter replacement is the most common type of repair required for septic tanks. Luckily, it is affordable, costing between $250 and $275 only.
Cost To Replace A Septic Tank Pump
The pump is an important part of the septic tank system because it allows you to pump your septic tank and remove waste, which is necessary every two to five years.
If your pump breaks, replacement will be a little pricey, costing between $500 and $1,200.
Cost of a Septic Tank Lid
You may have to replace your tank lid if you notice signs of damage. Concrete lids can be susceptible to cracking, whereas steel lids may rust over time.
Septic tank lids are affordable, costing only $30 to $70 to replace.
Tank Baffle Replacement Cost
The baffle directs the waste within the septic tank so it does not disturb the natural scum layer inside the tank. Replacing the baffle is also affordable, and costs just $25 to $50.
Cost to Install a Septic Tank Riser
A septic tank riser is a piped shaft connecting the septic tank to the ground level, which gives you enhanced access to the tank.
A septic tank riser costs between $300 and $400. Many consider it advantageous despite the price because it gives the maintenance crew easy access to the septic tank for any repairs that are required as well as for maintenance checks.
Newer septic tanks tend to be built with a riser, but if you have an older tank you can still decide to attach one.
There are two main materials used to make septic tank risers: concrete and plastic. A concrete septic tank riser is heavier than a plastic one, making it more difficult to install.
Concrete risers come in square, round, or rectangular holes and walls with varying lengths. Walls of a concrete riser tend to be between 3 and 4 inches thick.
The price varies significantly based on a range of factors, so the best way to get an estimate is to seek a quote from several contractors.
Plastic septic tank risers are much more lightweight than concrete risers, although they are less durable.
Because of their lightweight nature they are easier to install and remove than concrete, reducing the labor costs required. Expect to pay between $100 and $350 for a plastic septic tank riser, not including labor.
| Item | Average Cost |
|---|---|
| Septic Tank Riser Installation | $200 – $250 |
| Concrete Riser (materials only) | Price varies |
| Plastic Riser (materials only) | $100 – $350 |
Septic Tank Installation Process
Installing a septic tank is a long and difficult process, with many complex steps involved. From beginning to end, expect the project to take three to five weeks.
Although it may take longer depending on the complexity of the septic system you are installing and how long it takes to process your permits.
Step One: Soil Testing
First and foremost, the soil must be tested in order to reveal many factors about the soil itself, including what type of soil is present, what layers of soil exist and where those layers are, and more broadly how well suited the area is to filter and drain from the septic system.
If the test yields positive results, you will then be able to get approval for the leach field (also known as drain field).
Soil testing costs between $1,000 and $2,000.
Step Two: System Design
The second step in the process is to design the septic system, which can take between two and three weeks.
On average, a septic system design will cost $600 to complete.
Step Three: Land Clearing
If you need to clear the land where the septic tank will be installed, expect to pay about $1,000 per every quarter acre.
This price estimate is for light clearing of an area without rocks; for more extensive jobs, the price will be higher.
Step Four: Install Pumps and Tank
This is the most important step of the process. The tank and pipes must be installed properly to avoid damage down the line.
Pipes will cost between $25 and $35 per linear foot and the tank will cost between $1,000 and $1,500.
Step Five: Leach Field
A leach field provides critical draining to the septic system. Expect to pay between $3,500 and $10,000.
Step Six: Inspection and Testing
Next the septic system must be inspected and tested to ensure it functions properly and is up to code.
Building permits will cost between $250 and $500. Check with your local Health Board to determine which permits are required.
Step Seven: Pump Alarm
Adding a pump alarm will cost you about $750.
Step Eight: Landscaping
Be sure to factor in the cost of any landscaping you want to complete once the septic tank is installed and the dirt has been backfilled on top. The price will vary significantly based on what type of landscaping you are looking for.
How Long Does a Septic Tank Last?
A septic tank lasts an average of twenty five years. This number can vary significantly between fifteen and fifty years. The lifespan of a septic tank will depend on several factors.
The material you choose will impact the lifespan of your septic tank. Well made concrete septic tanks can last forty years or longer, whereas plastic septic tanks can last thirty years or more. Stainless steel septic tanks only last between twenty and thirty years.
How well you maintain your septic tank will also impact the price. A septic tank should be inspected every one to three years and should be pumped every three to five years. Not properly maintaining your septic tank is sure to decrease its lifespan.
Another factor that influences the lifespan of the septic tank is the type of soil. There are many different soil types out there, and some will cause a septic tank to become damaged more quickly than in other soil types. This factor cannot be controlled, unfortunately.
Finally, if there is vehicle traffic over the septic tank that is a sure way to reduce its lifespan.
Driving over the septic tank leach field may compress it and cause damage, so do not drive over the septic tank.
Can I Install a Septic System DIY?
Because the labor costs of installing a septic tank are so significant, you may be tempted to install a septic tank DIY.
However, installing a septic tank is a complicated and difficult process and any mistakes can lead to expensive repairs, water pollution, or damage to the home.
Also, if you install a septic tank without a permit, it will be difficult to sell your home and get insurance.
For these reasons it is highly recommended to leave installing a septic tank to the professionals.
How to Maintain a Septic Tank
Septic tanks are relatively easy to maintain. They must be inspected by a professional every one to three years, and they must be pumped every three to five years.
One way to maintain a septic tank is to be sure nothing improper ends up inside it. As a rule of thumb, only every flush human waste and toilet paper.
Anything else, including pharmaceuticals, chemicals, wet wipes, menstrual products, paper towels, tissues, etc., should be disposed of elsewhere and not flushed down into the septic tank.
By following this rule you will prevent damage and significantly lengthen the lifespan of your septic tank.
Why Is My Septic System Failing?
Its important to realize that very often we assume that the septic issues we are having in the house is because the septic tank is failing, however that’s not always the case.
Two common reason why your septic system is failing may be:
1. Problems with sewage lines: the line may be cracked, damaged or clogged. A loose or sagging pipe can also cause issues with the line.
2. Problem with the leach field: the field may have reached the end of its service life. If this is not the case, there may be issues with clogging, drainage and distribution box.
Septic Tank Replacement ROI
If you are planning to sell your house and considering replacing your old but functional septic tank system to increase the value of your house you are actually better off investing into a different home improvement project!
It turns out that septic tank replacement has one of the worst ROI of all remodeling projects, only around 10-20% at best.
On the other hand, in most states, like Massachusetts, you cannot sell a house without passing Title V, which means you cannot have a failed septic tank when you are selling your home.
So, don’t bother replacing an old septic tank unless you absolutely have to, either for yourself or in order to put your house up for sale.
WOW! Very detailed. Thank you!