The average septic system costs between $3,615 and $12,408. Your septic pro will consider the system type, size, and location for a personalized quote.
The cost of a septic system is between $3,615 and $12,408 for most homeowners, with the national average falling at $8,011. The total cost depends on three main factors: the materials, the labor required to install the system, and the cost to dig a leach field on your property.
Simply put, waste is a part of life. Handling it isn’t pretty, but septic tanks get that job done for you. Here’s how you can budget for the installation.
The septic tank size you need will depend on the number of bedrooms your home has. For a three- or four-bedroom home, you’d need a 1,000-gallon septic tank, which costs $900 to $1,500 for the tank alone.
Larger houses tend to have more sinks, toilets, bathtubs, and other wastewater sources that flow into the septic tank. As tank size increases, so do costs.
| House Size | Tank Size (Gallons) | Average Cost |
|---|---|---|
| 1 bedroom | 500 | $500–$900 |
| 2 bedroom | 750 | $700–$1,200 |
| 3–4 bedrooms | 1,000 | $900–$1,500 |
| 5–6 bedrooms | 1,200 | $1,200–$1,600 |
| 6–7 bedrooms | 1,500 | $1,500–$2,500 |
Septic tanks are commonly made of plastic, concrete, or fiberglass, with fiberglass tending to be the most expensive. Here’s how much a tank costs based on each material.
| Material | Average Cost |
|---|---|
| Plastic | $500–$2,000 |
| Concrete | $700–$2,000 |
| Fiberglass | $1,200–$2,000 |
Labor costs can differ by region and will depend on the size and materials of the new septic tank system. Labor costs typically account for 50% to 70% of the total septic tank system cost. You’ll likely pay more for installation than you will for the tank alone, but installing a septic system is a complex undertaking that requires special skills, making it worth every penny to hire a local septic tank installer.
Make sure you discuss details with your septic tank contractor. If they don’t cover excavation costs, expect to pay another $1,500 to $6,300.
Each septic system type comes with its own set of pros and cons. While anaerobic systems are relatively low-maintenance, they aren’t great for small properties. Similarly, anaerobic systems can do well in small spaces but require extra work.
| Anaerobic | Aerobic |
|---|---|
| Anaerobic bacteria break down waste | Aerobic bacteria break down waste |
| More affordable | More expensive |
| Uses fewer chemicals | More efficient |
| Needs a larger leach field | Good for smaller properties |
Septic tanks can be either anaerobic (not needing oxygen) or aerobic. Anaerobic systems are more common and cost between $3,000 and $8,000 on average. They’re typically cheaper to install than aerobic systems but are less efficient and call for a larger leach field.
In an anaerobic septic system, a pipe runs from the house to the septic tank, where another pipe runs from there into the leach field. Anaerobic bacteria break down solid waste before the system distributes the wastewater into the soil. These systems don’t require extra power or chemicals, making them a popular choice among homeowners.
Aerobic septic systems utilize oxygen pumped into the tank to activate bacteria that feed on the solid waste. These systems are more expensive than anaerobic systems at $10,000 to $20,000, but they’re more efficient and can work well for smaller properties. Unlike anaerobic systems, they do need additional power to run. To ensure everything works properly in the case of a power outage, hook it up to a power generator. Otherwise, aerobic systems can plug into your property’s main power source.
You’ll need to get a land survey before you can install a septic system. This makes sure that your plans fall within property lines (and saves you a legal headache). Expect to spend $330 to $900 for a licensed land surveyor.
Before you can install a septic system, you need to have a perc test performed by a local perc test pro. This test will measure the soil type and height of each sediment layer on your property to determine the best type of septic system for you. The cost to test soil is $700 to $2,000.
Septic tank systems consist of a septic tank and a kind of trench, commonly referred to as a leach field or drain field. This section of your septic system transports the wastewater back to the soil. Drain field installation costs $5,000 to $12,000.
Your soil has to have the proper conditions to be a good candidate for a leach field. If your soil isn’t in good condition—say you failed a perc test, your yard is too small, or you have a shallow water table—you’ll need to consider an alternative option. Consult a local septic system professional if you need an alternative way of draining wastewater.
Depending on the laws where you live, you may need to obtain one or more building permits or licenses to install a new septic system. Permits cost anywhere from $450 to $2,300, though some jurisdictions have lower fees. Check on the rules in your local area before breaking ground to avoid surprise fees later on.
In addition to the core costs of the septic system, there are some extra maintenance expenses that can quickly add up, depending on the condition of your property. Here are some common services you may need to factor in:
Old septic tank removal costs $45 to $200 per hour.
Land clearing costs $1,200 to $4,800.
Landscaping costs $5 to $24 per square foot.
A septic tank riser costs $300 to $600.
A pump alarm costs $500 on average.
Septic tank pumping costs $300 to $600.
Septic distribution box replacement costs $500 to $1,500.
Pump replacement costs $800 to $1,400.
Baffle replacement costs $300 to $500.
Filter replacement costs $230 to $280.
Tank lid replacement costs $30 to $70.
Drain field replacement costs $7,000.
Sometimes, a property isn’t suitable for a traditional septic system—whether you have a high water table, high bedrock, poor soil quality, or a smaller-sized property without room for a regular drain field. In this case, you may want to look into alternative types of septic systems.
| Alternative System | Average Cost |
|---|---|
| Mound | $10,000–$20,000 |
| Sand filter | $7,000–$18,000 |
| Chamber | $5,000–$12,000 |
| Drip | $8,000–$18,000 |
| Evapotranspiration | $10,000–$15,000 |
| Build wetland | $5,000–$12,000 |
Expect to spend more on a mound septic system—they cost $10,000 to $20,000 to install. They pump wastewater from the tank into a sand mound, which is built over top of the septic system area. The sand filters the water before it goes into the soil and groundwater. These systems are expensive, but they’re necessary in areas with a high water table.
Sand filter septic systems use a pump to push the wastewater through a sand filter at a low pressure before it enters the soil or groundwater, effectively treating and removing nutrients. Nutrients like phosphorus and nitrogen naturally occur in waste, but they can reduce water quality and damage aquatic ecosystems when they accumulate in surface water.
They cost between $7,000 and $18,000 and can be built either above or below ground. Sand filters protect the underlying water table from not-so-clean septic wastewater (great news for the environment), and they can last decades. These systems are best for areas with high water tables or that are near bodies of water.
Chamber septic systems are similar to conventional systems, but they use plastic chambers in the leach field rather than gravel. They cost $5,000 to $12,000 to install. Chamber septic systems are great choices for places where input volumes vary, like vacation homes.
If you do opt for this style, avoid placing it near your driveway or parking area, as driving over it could cause serious (and smelly) damage.
Drip septic systems use drip tubing and a dosing system to periodically release smaller, timed doses of waste. They work well in areas with a shallow soil depth. Drip septic systems require more components than a conventional septic system, including a dosing tank and pump, and can cost anywhere from $8,000 to $18,000, depending on their size.
Evapotranspiration septic systems cost $10,000 to $15,000 and are useful in arid climates and in areas with shallow soil. They have unique leach fields that allow effluent to evaporate from the top of an open-air tank. If you live somewhere where there’s a chance of snow or rain, just say no to an evapotranspiration septic system. The moisture could ultimately cause them to fail, and the repair process for a septic tank isn’t glamorous.
As you may have already guessed, built wetland septic systems mimic the natural water treatment process seen in wetlands. Microbes, plants, and bacteria treat effluent in a wetland tank before releasing the wastewater into the soil. In turn, the waste helps the plants and microbes thrive. These sustainable systems run from $5,000 to $12,000.
While DIY septic system installation is off the table in most cases, there are still some tasks you can easily do yourself to save money. Once you’ve selected an installation company, work with them to identify which of the following you may be able to handle on your own:
Compare multiple quotes. Request quotes from multiple contractors as you would for any other home improvement project. You might discover that one is more cost-effective than the rest, but be sure to consider the company’s reputation and experience.
Coordinate your own soil tests. You might be able to save some money by gathering soil samples yourself to send to a lab rather than have an on-site technician collect them.
Confirm compliance with local code. Code violations cost time and money. Check with your septic tank pro to see if you can save both by requesting the necessary permits yourself.
Plan for work during the off-season. If you plan ahead, you might be able to take advantage of discounts and easier availability when you hire a septic tank professional in the slower season.
Prepare the landscape. While tree removal is a job for the pros, you can save money by doing other landscape prep work, including backfilling, where possible. You will need to follow the plans laid out by your professional installer, but you could significantly cut down on labor costs by doing some of the digging on your own.
Purchase materials. As with all home improvement projects, you might be able to save money and buy materials separately so that you’re just paying for labor costs.
Follow a rigid maintenance schedule. By committing to regular maintenance and pumping by a septic system professional, you can ward off any potential—and expensive—problems.
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A septic tank lasts 15 to 20 years on average. This life span will vary depending on the type of septic system and the materials used. Clogging caused by plant roots or flooding from groundwater can decrease that life span. To avoid these issues, have a pro inspect your tank regularly and perform routine maintenance, such as pumping out the tank.
A septic tank needs to be pumped once every three years on average. However, every septic tank has different needs, and the proper service interval for your system may be every five years, or as frequent as an annual pump-out. Consult with your installer about the proper interval and what to expect regarding the cost of septic tank pumping.
When septic systems begin to fail, your waste will start to seep into the groundwater. You may notice a foul odor (it’ll smell like sewage) or a squishy, moist lawn. The grass right over your tank or drain field might grow super lush and green because your waste actually fertilizes it. Other signs include standing water in your drain field, slow-draining sinks and tubs, and gurgling noises in the plumbing.
