How Much Does Septic Tank System Installation Cost?

Do septic tank replacement costs keep you awake at night? Do you know that nearly 17% of all new homes have a septic tank? When correctly installed and maintained, a septic system can reliably treat your home’s effluent for decades to come.

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Whether replacing an old septic system or installing a new one, this guide helps you understand the average septic tank prices for a new or replacement system.

What Is Involved in Installing a New Septic Tank System?

Designing and installing a septic system is a relatively complex task that requires specialized skills and equipment. It’s not a task that’s suited for DIY installation, and it's best to work with a plumber who specializes in septic systems. Before getting started, you need to get the system designed and obtain permits and approvals from your local authority.

Septic System Design

The first step is to design the septic system. It must be adequately sized for the size of your home. The design should show the location and size of the major components, such as the septic tank and drain field, and cover the entire septic system. Working with a local septic designer, the basic design should cost between $450 and $900 (CAD 640 and CAD 1,280). Local regulations may also require a sign-off from a civil engineer, which may cost a further $700 to $2,000 (CAD 995 to CAD 2,843), depending on topography and geological conditions on your site.

Soil Conditions

As part of the design process, you need to have the soil conditions evaluated to verify that it will support your wastewater drainage. This survey costs between $100 and $400 (CAD 142 and CAD 569). You may also need to do a percolation test to measure drainage rates.

Tank Location

The evaluation process should include finding the best place for the septic tank. This should be reasonably close to the home and below it in terms of drainage.

Drain Field

The drain field is where the waste liquid from the septic tank is discharged into the soil. It’s sometimes called a leach field. There are different types of drain fields, and the right choice is related to soil conditions, property size and effluent volumes.

Permits

Before you can start work, you need to obtain a permit from the local authority for your area. The authority may need to see the septic tank design and soil evaluation reports. Permitting costs differ depending on your state and the complexity of the project. You can expect to pay between $250 and $1,000 (CAD 355 and CAD 1,421) for the permit.

Financing

The overall cost of a new or replacement septic system is high. Financing options can include a home improvement loan from your bank or a home equity loan that uses your home as collateral. Some contractors may be able to offer their own financing. Alternatively, you might consider using a credit card, but you should check interest rates first.

What Is the Average Total Cost of a New Septic System?

When estimating home septic system costs, you need to consider all the expenses involved. Apart from the design, permitting and material costs, you should factor in excavation and labor costs and make an allowance for miscellaneous items. These include sewer pipes and other fittings and materials you need.

The following section explains the major costs involved. Based on the figures below, you can expect the total cost of a septic system to be between $8,200 and $20,300 (CAD 11,655 and CAD 28,853).

Design and Permits

Together with permitting, you can expect to pay between $800 and $2,300 (CAD 1,137 and CAD 3,269) for the system design and permits. The costs will be higher if you need a civil engineer to sign off on the design.

Septic Tank Price

Septic tank prices depend on their size and the material of construction. Common septic tank materials include concrete, polyethylene and fiberglass. The Home Shift Team says a standard 1,000-gallon septic tank usually costs between $1,000 and $1,500 (CAD 1,421 and CAD 2,132).

Drain Field

After the septic tank, the drain field is the most critical part of the septic system. The drain field comprises a series of pipes laid in gravel and stones. The pipes have holes that let the wastewater disperse into the leach field. Alternatively, the drain field may have a series of long plastic chambers laid in the soil, or it may be a pumped drip system that performs the same function. According to Today’s Homeowner, the cost of building a drain field can vary from $5,000 to $12,000 (CAD 7,107 to CAD 17,056).

Excavations

You need to dig a deep trench for the septic tank and shallow trenches for the drain field and interconnecting pipelines. Today’s Homeowner suggests you allow between $1,500 and $6,000 (CAD 2,132 and CAD 8,528) to hire the excavator.

Installation and Miscellaneous Items

The contractor needs to install risers for septic tank maintenance and connect the septic tank to the home sewer and drain field. NerdWallet suggests you allow between $1,500 and $4,000 (CAD 2,132 and CAD 5,685) for labor and installation costs.

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How Much Does Septic Installation Cost by Tank Size?

The septic tank size and price are related to the size of your home and household. The figures below are based on the amount of effluent generated, but it should be noted that some local authorities don't allow septic tanks smaller than 1,000 gallons. The approximate septic tank sizes for homes of differing sizes are:

• One-bedroom house. A 500-gallon plastic septic tank is large enough for most single-bedroom homes. An underground plastic septic tank from National Tank Outlet costs between $900 and $1,000 (CAD 1,279 and CAD 1,421).

• Two-bedroom home. A two-bedroom home needs a slightly larger 750-gallon septic tank. Prices range from $1,200 (CAD 1,706) for a plastic tank from National Tank Outlet to $2,000 for a fiberglass tank (CAD 2,843).

• Three- to four-bedroom homes. A typical family home requires a 1,000-gallon septic tank. The cost of this capacity septic tank varies between $1,000 for a concrete tank and $3,000 for a fiberglass tank (CAD 1,421 and CAD 4,264).

• Larger homes. For a home with multiple bedrooms, you should consider a 1,500- to 2,000-gallon septic tank. These cost between $1,500 and $4,000 (CAD 2,132 and CAD 5,685).

How Much Does Septic Installation Cost by System Type or Tank Material?

The cost of a septic system is influenced by two further factors: the type of septic system and the tank material.

Anaerobic Septic System

This is the standard septic tank system that relies on microorganisms that thrive in an environment that lacks oxygen. The septic tank is placed below the home, and the drain field is slightly further down the slope so that effluent is distributed by gravity. They require minimal maintenance apart from periodic inspections and pumping out the solids every few years. Using the figures provided by Today’s Homeowner, the cost of anaerobic systems including the drain field varies from $8,000 to around $13,000 (CAD 11,371 to CAD 18,478).

Mound Septic System

This is a variation of the anaerobic system used when soil conditions aren’t suitable for a conventional drain field. In place of a leach field, a layered mound is built. Effluent is pumped into pipes in trenches inside the mound. Mound systems are more expensive to build and require a pumped system. According to National Tank Outlet, the cost of a mound septic system is between $12,000 and $20,000 (CAD 17,056 and CAD 28,427).

Aerobic Septic System

An aerobic septic system uses a conventional septic tank fitted with an air pump that supplies the oxygen needed for aerobic digestion. The waste is discharged to a drain field. Aerobic systems are more expensive than anaerobic systems and typically cost between $10,000 and $20,000 (CAD 14,213 and CAD 28,427).

Pros and Cons of Different Septic Tank Materials

The most common septic tank materials are concrete, polyethylene and fiberglass.

Concrete Septic Tank Cost

Concrete septic tanks are cheap and robust. Their downside is their weight, which means you need a crane to lift them into position. They may also crack if not properly supported. A 1,000-gallon tank typically costs between $1,000 and $1,500 (CAD 1,421 and CAD 2,132).

Plastic Septic Tank Price

Plastic septic tanks are manufactured from polyethylene. They're light and easy to handle. Polyethylene is durable and resistant to cracking. Prices for a 1,000-gallon plastic tank from National Tank Outlet vary from between $1,700 and $2,311 (CAD 2,416 and CAD 3,284).

Fiberglass Septic Tank Prices

Fiberglass septic tanks are lightweight and reinforced for extra rigidity. They're better than plastic tanks for locations where the soil conditions fluctuate. According to Septic Safe Solutions, prices for a 1,000-gallon fiberglass tank are between $1,500 and $3,000 (CAD 2,132 and CAD 4,264).

All CAD conversions are based on the exchange rate on the date of publication.