Septic tank installation is essential to ensure your home has proper wastewater management. But how do you know where to begin when installing a septic tank?

Whether you need to replace an existing septic system or are planning to install a septic tank in a new house project, this post will go through the basics you need to know to install a septic system.

This post is for informational purposes only. Always check with your permitted authority or regulatory body before installing a septic system.

What is a septic tank?

Before we start talking about the steps of installing a septic system, we should first answer the questions, “What is a septic tank?” and “How do septic systems work?”

A septic system helps you manage household waste when your home isn’t connected to a sewer system. This is especially common in more rural areas where houses are far apart and there isn’t a public sewer system. According to the United States Environmental Protection Agency (EPA), one in five US households relies on a septic system for wastewater management.

In these houses, the waste and water from toilets, sinks, and any other drains still need to go somewhere. So, this waste material and water go into a septic tank. 

How do septic systems work?

The septic tank isn’t just a giant tank where all this material sits. If it were, it would fill up way too quickly. Instead, septic tanks contain a filtration system that reduces the amount of waste in the tank and releases filtered water into the soil. This way, the tank can handle all of a household’s waste for an extended period of time.

Septic systems also contain a drainage field. This is where filtered water from the septic tank gets released back into the ground.

Septic tanks require regular maintenance after installation. They need to be emptied every three to five years. Plus, you should always be on the lookout for any signs of failure because these can lead to problems. 

How to install a septic tank

Septic tank installation is a multi-step process. Here are the main steps to plan for when installing a septic system.

Septic system plans are an essential part of installing a septic tank

The first step of installing a septic tank is to take care of any legal requirements. Many states require specific permits and a license to construct and install a septic tank. Some places will also require soil testing before work can begin.

Once you’ve determined that you can install a septic tank, you need to decide where it will go. This is critical because a septic system needs to be strategically placed on your property. Here are some quick tips for picking a spot for your septic tank:

  • Choose an area with level ground

  • Avoid tree roots that could damage your tank

  • Avoid areas that are prone to flooding

  • Ensure you have enough space for the drainage field

The drainage field needs to be in an area where the soil has good drainage — without good drainage, the septic system won’t work properly. Soil testing results can help you determine the best placement. And if you’re working with contractors to install your septic tank, they can also make some recommendations. 

The septic system also needs enough room to hold the septic tank and the drainage field. You’ll need to dedicate enough space on your property to install your septic system and ensure any digging doesn’t interfere with underground systems that may already be in place, such as electrical, gas, or other utilities. When in doubt, you should always call 811 before you dig to ensure you stay safe.

You can even draft a site plan for your property. This will allow you to look at the entire property from above and see what is already there. Then, you can use this information to determine where the parts of your septic system will go. 

Planning your septic system

Next, it’s time to pick the type of septic system you’ll install. Septic systems are not universal. There are many different types out there, and the one you choose will depend on your situation.

A conventional septic system is the most common type. These have a tank with excess water leading to a drainage field. This drainage field has trenches with gravel and sand that help filter the water out further. This is similar to a chamber system, which uses chambers instead of gravel and sand.

A drip distribution system is great for yards that cannot accommodate a large drain field. Drip systems require less than a foot of depth in the soil. However, these systems will require additional room near the tank itself to regulate the dripping.

A yard where you can’t dig too deep into the ground may require a mound system. In these systems, a mound is built above the ground to accommodate the septic system.

On top of these, there are several other types of systems out there. These include sand filter systems, evapotranspiration systems, community systems, and more. However, these are less common — most homeowners will end up installing a conventional septic system. 

Installing the septic system

Digging is one of the steps required for septic tank installation

Now it’s time to actually install your system. Because of the safety concerns and complex nature of septic systems, it’s best to work with a professional for the installation. They will be able to guide you and give you advice.

Once you have a location picked out, you’ll need to start digging. Because the entire system is located underground, digging is a critical step in installing a septic tank. Remember, always check it’s safe to dig before you start.

You’ll need to dig several trenches for the drainage pipes. These will need to be lined with gravel and sand, which will help disperse water into the soil. Meanwhile, the tank will need to be placed several feet into the ground. Most septic tanks are buried between 4 inches to 4 feet below the ground’s surface. How deep you bury your tank will depend on the specifics of your septic system and installation site. Digging this type of trench requires excavation equipment, which your professional installer can supply.

Finally, the entire system needs to be installed. During this step, the entire system is put into place, connected, and then buried back into the earth. At the end of this step, the system is installed and is ready to function!

Once the system is in place, it is important not to disturb it. Remember where it is when you start your next landscaping project. The last thing you want is to dig into your septic system’s drainage field. 

Install a septic system the right way

Work with a professional to help you install a septic system

That’s the simple guide to septic tank installation. You need to create a plan and examine the site, determine what type of septic system you need, and install it on your property. Once you complete these steps, your new system will be ready to go!

The septic system installation process isn’t always straightforward, so we hope this guide will help you get started. If you need help visualizing where your septic system should be installed, get in touch with our team at My Site Plan. We can create a site plan to help you get permits, plan your installation, and more.

Septic tank installation FAQs

How much does it cost to install a septic tank?

According to data from Angi, septic tank installation costs can range from $3,491 to $11,744. The average cost to install a septic system is $7,611.

Can I install my own septic tank?

While you can technically install your own septic tank, it’s always a good idea to enlist professional help. In many states, you need a license and permit to install a septic tank. These safeguards are put in place because if a septic tank is installed incorrectly, waste can leak into groundwater and nearby waterways, creating health risks to your local area and community.

The same goes for performing maintenance on your septic system — professional help is always the way to go. Septic tanks contain bacteria that can be dangerous, so consulting a septic system specialist is the safest option. 

Does a septic tank need a concrete base?

Septic tanks need a solid base to sit on. This ensures that the weight of the septic tank and its contents are evenly distributed. Creating a concrete base for your septic tank is one of the best ways to ensure the tank isn’t put under too much stress. 

What is the best place to put a septic tank?

Septic tanks should always be installed somewhere with level ground. It’s also a good idea to put your septic tank in an area that isn’t likely to flood and is clear of any tree roots that could damage the tank.

What are some signs of septic tank failure?

After installing a septic system, you’ll need to perform regular maintenance to ensure it keeps working properly. Here are a few signs that your septic system might be failing.

  • Slow drains - Slow-draining sinks, toilets, and showers could be a sign your septic tank is full or backed up.

  • Bad smell in the yard - If you notice a bad smell (like sewage) when outside your home, it could be a sign that the septic tank is full.

  • Pooling water in the yard —If your septic tank is filling up and you continue using your plumbing inside, septic run-off could pool up in your yard.

  • More insect activity - An increase in bug activity, like flies and mosquitoes, could mean something is wrong with your septic tank.

  • Gurgling pipes - If your septic tank gets clogged, air will get trapped in your pipes, which can cause a gurgling or “burping” sound when you use your plumbing.

  • Waste backups in the house - The worst-case sign of septic tank failure are clogs and waste backups in your home's toilets, sinks, showers, and drains.

If you notice any of these signs, you should call a specialist to inspect your septic system. Though you can install a septic system by yourself, the bacteria within an active septic system can be hazardous. A septic specialist will know the best way to handle any issues.


Question Answer
What are the legal consequences of installing a septic tank without a permit? Installing a septic tank without the necessary permits can result in fines, legal penalties, and the requirement to remove or modify the installation at the owner's expense. Always check with local authorities for specific regulations in your area.
How often should soil testing be conducted for a property with a septic system? Soil testing should be conducted initially to determine the suitability for a septic system installation. It's also wise to perform periodic testing if conditions change or if the system exhibits any problems, though specific frequencies depend on local regulations and expert recommendations.
Can landscaping affect an existing septic system? Yes, landscaping can affect a septic system. Deep-rooted plants and trees can damage the septic tank or pipes. Additionally, heavy equipment used in landscaping can compact the soil or damage components of the septic system buried underground.
What are the typical dimensions of a septic tank? The size of a septic tank varies based on the number of bedrooms in a home and the average wastewater generated. Typically, tanks range from 750 to 1,250 gallons for residential installations.
Are there eco-friendly alternatives to traditional septic systems? Yes, there are eco-friendly alternatives such as constructed wetlands, sand filter systems, and aerobic treatment systems. These systems often use natural processes or enhanced aeration to treat wastewater more effectively and reduce environmental impact.



This post was originally published on 2023-05-08, by Ryan Crownholm. It was updated on 2024-04-30 to reflect the most recent data.