Slow drains, unpleasant odors, or pooling water are all stressful signs that your septic system may be failing. When it's time for a replacement, the project can feel overwhelming. A new septic tank installation is your opportunity to get your home's wastewater management right for the long term. But where do you start? It involves more than just installing a new tank; you have to consider the old system and plan the new one carefully. We’ll guide you through the process, helping you understand the unique steps involved and plan for a smooth transition.
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.
Table of content
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.
Understanding Septic System Installation Costs
Okay, let's talk numbers. The cost of installing a septic system can vary quite a bit based on your location, soil type, and the system you choose. While the total price tag might seem high, breaking it down helps you see where your money is going. The average cost for a new septic system installation typically falls between $3,000 and $10,000, with most homeowners spending around $6,000. Understanding the individual expenses, from permits to the tank itself, will help you budget effectively and avoid any surprises along the way. Let's look at the main components that make up the total cost of the project.
Breaking Down the Expenses
The total installation cost is a sum of several key parts. You'll need to budget for the initial paperwork, the physical labor, and the tank itself. Understanding these individual costs will give you a much clearer picture of the overall investment.
Permits and Soil Testing
Before work begins, you must get permits from your local health department, which typically cost around $400. This crucial step ensures your project meets all local codes. The process requires a soil test to confirm the ground is suitable and a detailed site plan showing the proposed system's location on your property. This plan is a key part of your permit application.
Labor and Excavation
The physical work is a major expense. Installation labor costs about $160 per hour, and the excavation for the tank and drain field can add another $1,500 to $6,300 to your bill. This cost varies based on the size of the system and soil conditions, making it one of the biggest variables in the project's budget.
Septic Tank Costs by Material
The tank itself is a significant cost factor, with prices depending on the material. A lightweight plastic tank can cost as little as $800, offering a budget-friendly choice. For a more durable option, a heavy-duty concrete tank can go up to $6,700. Your choice will depend on your budget and long-term needs, balancing upfront cost with the tank's expected lifespan.
Costs for Different System Types
Not all septic systems are created equal, and the type you need will heavily influence the final cost. A conventional system, which uses gravity to move wastewater from the tank to the drain field, is the most common and generally the most affordable, with total installation costs often landing in the $3,000 to $10,000 range. However, if your property has challenging soil, a high water table, or limited space, you might need an alternative system. These can include mound systems or aerobic treatment units (ATUs). These more complex setups require additional components and specialized installation, which can push the total cost significantly higher.
How to Save Money on Installation
While a septic system is a major investment, there are ways to manage the expense. The most effective strategy is to get multiple quotes from different licensed contractors. Don't just go with the first price you receive; comparing at least three detailed bids will give you a clear sense of the fair market rate in your area. You can also find savings in the planning phase. For instance, using an online service like My Site Plan for your permit drawings is often faster and more affordable than traditional methods. It allows you to get a high-quality plan for your application without the time and expense of scheduling on-site visits, helping you get your project started on the right foot.
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.
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.
General Contractor vs. Subcontractor: What's The Difference?
When Do You Need a Permit to Work on Your House
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.
Creating a Site Plan for Permits
Before you can break ground, your local building department will almost certainly require a site plan for your permit application. Drafting a site plan for your property allows you to look at the entire property from above and see what is already there. This information is crucial for determining where the parts of your septic system will go, including the tank and drain field, while showing compliance with local codes. Our team at My Site Plan specializes in creating permit-ready site plans using GIS data and satellite imagery, delivering them in under 24 hours so you can keep your project moving without delays.
Choosing the Right Tank Size
Septic tanks come in various sizes, and choosing the right one is critical for a functioning system. The size you need isn't based on how many people live in your house, but rather on the number of bedrooms. This is the standard used by most health departments to estimate potential water usage. For example, a three-bedroom home typically requires a 1,000-gallon tank, while a five-bedroom home might need a 1,500-gallon tank. Always confirm the required tank size with your local health or building department, as their regulations are the final word on what’s acceptable for your property.
Placement Rules and Setbacks
Where you install the septic system is governed by strict rules. You’ll need to choose an area with level ground and avoid spots with large tree roots that could damage the tank or pipes. It’s also vital to stay away from areas prone to flooding. Beyond these practical considerations, you must adhere to "setbacks," which are minimum required distances. For instance, a septic tank usually needs to be at least 10 feet from your house, 50 feet from any well, and 10 feet from property lines. These distances can vary by municipality, so check your local codes to ensure your planned location is compliant.
Technical Design Considerations
The drain field, or leach field, is just as important as the tank itself. The drain field needs to be in an area where the soil has good drainage—without it, the septic system won’t work properly. To determine this, most jurisdictions require a percolation test, or "perc test," which measures how quickly water absorbs into the soil. The results of this test will dictate the size and design of your drain field. Soil that drains slowly will require a larger drain field to handle the same amount of wastewater, which is a critical factor to include in your site plan and overall project design.
Installing the septic system
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.
The Installation Timeline
Installing a septic system is a significant project that involves several key stages, from initial property checks to the final inspection. The entire process requires careful planning and the expertise of professionals to ensure everything is done correctly. It's not a weekend DIY job. Having a clear visual from the beginning, like a detailed site plan, can help you and your contractor map out the location of the tank, drain field, and connecting pipes, making sure the layout complies with local regulations before any ground is broken. This initial step sets the foundation for a smooth installation.
Required Inspections
Don't assume you can start using your new septic system as soon as it's in the ground. Most local authorities require at least one inspection before giving you the green light. An inspector will visit your property to verify that the installation meets all local health and building codes. They'll check that the system is functioning correctly, with no leaks or other issues that could cause problems down the road. This step is non-negotiable and is in place to protect both your property and the environment. Passing this inspection is the final hurdle before your system is officially operational.
Replacing an Old System
If you're replacing an old or failing septic system, the process has a few extra steps. Before the new system can be installed, the old tank must be professionally pumped out, cleaned, and then either removed or filled in, depending on local rules. Be prepared for some temporary disruptions; your household water may need to be shut off for a day or two during the switch. This is a good time to reassess the placement on your property. An updated site plan can help you find the optimal location for the new system, potentially avoiding issues that affected the old one.
Septic System Maintenance and Lifespan
Once your septic system is installed, your job isn't quite done. Proper maintenance is the key to ensuring your system functions efficiently for decades to come. A little proactive care goes a long way in preventing costly repairs and extending the life of your investment. Think of it like regular check-ups for your car; ignoring small issues can lead to major breakdowns. By understanding how long your system should last and adopting some simple habits, you can protect your property and your wallet. Let's look at what that involves.
How Long Do Septic Systems Last?
A well-maintained septic system is a long-term investment in your property. On average, you can expect a septic system to last anywhere from 15 to 40 years. The wide range in lifespan often comes down to a few key factors: the type of system, the material of the tank, soil conditions, and, most importantly, how well you take care of it. With consistent, proper maintenance, it's possible to push your system's lifespan toward the higher end of that range, or even beyond. Neglect, on the other hand, can lead to premature failure and a costly replacement much sooner than you'd expect.
Daily Habits to Protect Your System
Protecting your septic system starts with your daily habits. Be mindful of what goes down your drains—avoid flushing anything other than human waste and toilet paper. Things like wipes, feminine hygiene products, and paper towels don't break down and can cause clogs. Also, limit the use of harsh chemical cleaners and garbage disposals, as they can disrupt the natural bacteria that break down waste. Beyond daily mindfulness, schedule a professional inspection and have your tank pumped every three to five years. This routine service is crucial for removing solids and preventing backups, saving you from much more expensive emergency repairs later on.
Landscaping Rules for Your Drain Field
The area above your drain field isn't just another part of your yard; it's a crucial component of your septic system. The best thing to plant over it is grass, as its shallow roots help with water absorption without posing a threat. Avoid planting trees or large shrubs nearby, as their deep roots can grow into the pipes and cause serious damage. If you have existing trees, consider installing root barriers. It's also important to keep heavy objects, like cars or equipment, off the drain field to prevent soil compaction and pipe damage. Using your property's site plan as a guide for landscaping projects will help you remember exactly where the drain field is located.
Install a septic system the right way
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.
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.
About the author
Ryan Crownholm
Ryan is a construction technology founder and former contractor with 15 years of hands on experience in residential and commercial construction. He has been creating site plans for more than 25 years, supporting tens of thousands of homeowners and contractors across the United States. As the founder of MySitePlan.com, his work is grounded in real world permitting requirements, plan review feedback, and practical compliance standards used by local building departments.
Key Takeaways
- Start with a Solid Plan: Before any digging begins, you need to handle the paperwork. Getting the right permits is a non-negotiable first step, and this almost always requires a detailed site plan to show your proposed system's location and prove it meets local regulations.
- Leave Installation to the Pros: Installing a septic system is not a weekend DIY project; it requires specialized equipment, knowledge of strict placement rules, and passing official inspections. Hiring a licensed professional ensures the job is done safely and correctly from the start.
- Protect Your System for Decades: A septic system's longevity, often 15 to 40 years, relies on proper care. Simple habits like only flushing appropriate waste, combined with routine professional pumping every three to five years, will prevent costly failures and extend the life of your investment.
