How Much Does a Septic System or Tank Cost?

Labor Cost to Install a Septic System

Labor usually makes up about 50% to 70% of your septic system installation cost. In fact, installing the tank often costs more than the tank itself. For example, while a tank for a three- to four-bedroom home might cost $900 to $1,500, you can expect installation to run between $1,500 and $4,000. Hiring a professional ensures the job is done right, giving you peace of mind and a system that lasts.

Besides the tank and leach field, you'll have a few other fees you'll need to consider in your budget. You may have some of these included in your overall project price, so ask for line-item costs on your estimate.

• Land excavation costs ($1,500–$5,600): This covers digging the area where your septic system will be installed.

• Building permits ($450–$2,300): You'll need permits to ensure your installation meets local regulations.

• Perc soil test ($700–$2,000): A percolation test checks if your soil absorbs water properly for a septic system.

• Septic tank riser ($300–$600): This makes accessing your tank easier for maintenance and pumping.

• Septic distribution box ($500–$1,500): This component evenly distributes wastewater from the tank to the leach field.

Septic Tank Cost by Size

How much you'll pay for a septic tank depends on the size. Larger homes require a larger tank that can meet the demands of a bigger household.

Anaerobic vs. Aerobic Septic Tanks

Anaerobic septic systems are the traditional choice and use bacteria that don't require oxygen to break down waste. The wastewater then flows to a large leach field where it further decomposes and filters through the soil. These systems are less expensive but need a larger leach field.

Aerobic systems are more complex and often include a composting toilet and a continuous flow system. This septic system is more expensive than the traditional anaerobic type but is more efficient. Because the effluent (or the sewage or wastewater) is of higher quality, these systems require a smaller leach field. Read more about the two system types below.

Anaerobic Septic System

The classic anaerobic system costs $3,000 to $8,000 to install on average. Anaerobic systems are typically more inexpensive to install than the more complex aerobic system, but they're not as efficient at cleaning the tank, so you'll need a larger leach field to pick up the extra workload.

An anaerobic septic system is a relatively simple system consisting of a pipe leading from the house to the tank and a branched pipe leading from there to the drain field. These systems rely on anaerobic bacteria (bacteria that don't use oxygen) to break down waste in the tank before further bacterial processing in the soil.

Aerobic Septic System

Aerobic septic systems are more efficient at breaking down waste because they use oxygen-loving bacteria. They cost between $10,000 and $20,000. While they're more expensive upfront, they often require a smaller drain field, making them a smart choice for smaller properties. If you're considering an upgrade from an anaerobic system, converting usually costs between $5,000 and $10,000.

An aerobic system is a wastewater system that relies upon aerobic bacteria (oxygen-loving bacteria) to break down waste in the tank. You'll need an aerator and an electrical circuit running to the system, and with small, mounded, or specialty fields, you may also need a dose or pump tank to push the effluent uphill or out in doses.

Alternative Septic System Costs

You’ll want an alternative septic system when you have a small property, high water table, high bedrock, bad soil, or simply want to use less space.

Chambered System

Chambered systems cost $5,000 to $12,000 to install. They use plastic perforated chambers around pipes often set in sand, eliminating the need for gravel. They're quick and easy to install but more susceptible to crushing forces, like vehicles.

Built Wetland

Built wetland systems cost $5,000 to $12,000 to install or more if you use an aerobic tank. They mimic the natural cleansing process found in wetlands and are treated by microbes, plants, and bacteria in a wetland tank before passing to the soil. The waste also supports the wetland plants and microbe population.

Sand Filter

Sand filter septic systems cost $7,000 to $18,000 to install. They're constructed either above- or below-ground and use a pump chamber to push the wastewater through a sand filter prior to dispersal in the ground. The filter box typically has a PVC lining, and the pump pushes the effluent through the sand and back to the pump tank, where it's then dispersed through the ground.

Evapotranspiration System

Evapotranspiration systems cost $10,000 to $15,000 to install. They use a unique drain field setup that allows the liquid to evaporate from the top of an open-air tank and are only useful in dry, arid climates that see little rain or snow.

Drip Septic System

Drip systems cost $8,000 to $18,000 to install. They work like other systems, except they use extensive drip tubing and a dosing system. They release smaller timed doses, which work well in shallow soil depths. But a drip system costs more than a traditional system since it requires a dose tank, pump, and electricity.

Mound Septic System

A mound septic system costs $10,000 to $20,000 to install. It’s the most expensive system but often necessary in areas with high water tables, shallow soil depth, or shallow bedrock. It relies upon an elevated sand mound for the drain field rather than excavating into the soil. Its increased expense comes from both the added machinery needed to pump effluent uphill into the mound and the materials and creation of the mound itself.

Septic Tank Costs by Material

The material you choose for your septic tank affects its cost and longevity. Most residential tanks cost under $3,000. Let's explore the common materials—concrete, plastic, and fiberglass—and see which is the right fit for your home.

Concrete

Concrete tanks cost $700 to $2,000, and total installation costs run $2,300 to $6,500. They’re one of the most common types installed and usually durable for a couple of decades because they’re susceptible to cracking or separation. It's important to have it manually inspected regularly against cracks and runoff. Inspections and regular cleanings help prolong its life span. Your pro can tell you how often to have it inspected, but it’s usually anywhere from one to three years.

Plastic

Plastic septic tanks cost $500 to $2,000 on average, not including installation. Plastic is a durable, lightweight, and relatively inexpensive material, and it rarely cracks like concrete and doesn't rust. However, plastic can be vulnerable to damage during installation because it’s so lightweight.

Fiberglass

Fiberglass septic tanks cost $1,200 to $2,000 on average, not including installation. Fiberglass doesn't crack easily or rust, but it's susceptible to damage during installation, like plastic. Also, the lower weight makes it more susceptible to structural damage, and the tanks themselves can shift in the soil.

Leach Field Installation Costs

A leach or drain field is the section of the septic system that transports the wastewater back to the soil and costs anywhere from $5,000 to $12,000 to install. The first sign of a problem with the drain field is often a swampy area in the yard or sewage odor on the property. A drain field replacement can cost anywhere from $10,000 to $50,000, depending on how much remediation you need for clogged or flooded fields.

Septic Tank Replacement Cost

At around $3,000 to $10,000, replacing the tank is considerably less costly than installing a completely new system because there are no excavation costs. If you need to replace the whole tank, there are some costs you need to be aware of. For example, you'll need to have the tank pumped and cleaned first to eliminate any remaining waste. Septic tank pumping costs $300 to $600, depending on the tank size.

When the system begins to fail, it may crack or corrode, causing the waste to leach into the groundwater. When this happens, the well water may become contaminated, the yard may turn swampy, and the septic system may stop functioning. Here's a rundown of specific septic tank parts and their average prices:

• Septic tank pump replacement: $800–$1,400

• Baffle replacement: $300–$500

• Filter replacement: $230–$280

• Tank lid replacement costs: $30– $70

• Drain field replacement: $7,000

When replacing your system, consult with your service pro about the pros, cons, and costs of upgrading to a more efficient aerobic system.

DIY vs. Hiring a Septic System Pro

Installing a septic system is complex and best handled by a local septic tank professional. A properly installed system protects your home and the environment, preventing costly issues down the line. Plus, having the right permits keeps your home market-ready and insurable. It's a good idea to interview at least three septic tank pros to find the right fit for your project. A trusted local septic tank installer will ensure the job is done right, giving you peace of mind.

How HomeAdvisor Gets Its Cost Data

No place is more important than your home, which is why HomeAdvisor connects homeowners with local pros to transform their houses into homes they love. To help homeowners prepare for their next project, HomeAdvisor provides readers with accurate cost data and follows strict editorial guidelines. We surveyed thousands of real customers about their project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.