You should do a septic inspection once every one to three years to ensure you don’t have any issues. Learn about septic inspection costs before scheduling.
Cost to Install a Septic System in Indianapolis [2025 Data]
Normal Range: $11,666 - $12,500
Septic system installation costs between $11,666 and $12,500 in Indianapolis, Indiana, with an average of $12,000. Your septic pro will consider the system type, size, and location for a personalized quote.
How we get this data
Photo: Petegar / Getty Images
Photo: Petegar / Getty Images
Highlights
Most septic system installations in Indianapolis use a conventional system with a precast concrete tank.
The high water table in the area can impact the design and increase the price.
Septic tank size requirements are determined by the number of bedrooms in a home.
The STEP program is phasing out septic systems in certain areas of Indianapolis.
In the state of Indiana, a whopping 800,000 homes use septic systems. While the cost to install a septic system in Indianapolis is slightly elevated compared to areas outside of the city, most homeowners spend $11,666 to $12,500—or an average of $12,000. If you’re looking to replace your old system or install one in new construction, these cost factors will help you price out your project.
Septic System Installation Cost Factors
Most of Indianapolis, Indiana, has good soil conditions for septic systems, but there is a high water table. This primarily impacts low-lying areas, but it can cause drainage problems that you might need to design your system around. The design will impact everything from tank size and materials to the type of system and drain field construction. Here are some factors to consider and how they influence the costs.
Tank Size
The septic tank size you need will depend on the number of bedrooms your home has. For a three-bedroom home, you’d need a 1,000-gallon septic tank, which costs $900 to $2,500 for the tank alone.
A small septic tanks cost less and will save you up-front cash, but Indianapolis has local requirements based on the size of your home. Larger houses have more sinks, toilets, bathtubs, and other wastewater sources that flow into the septic tank.
| Tank Size (Gallons) | Number of Bedrooms | Average Cost Range |
|---|---|---|
| 750 | 1–2 | $700–$1,200 |
| 1,000 | 3 | $900–$2,500 |
| 1,250 | 4 | $2,000–$3,800 |
| 1,500 | 5 | $2,500–$4,100 |
| 2,000 | 6 | $4,000–$5,000 |
Materials
Indianapolis allows for the use of septic tanks made of concrete, fiberglass, or plastic (polyethylene or polypropylene). Fiberglass is the most expensive, but precast concrete is the most common. Here’s how much a tank costs based on each material.
| Septic Tank Material | Average Cost (Tank Only) | Pros | Cons |
|---|---|---|---|
| Concrete | $700–$2,400 | Highly durable | Prone to cracks during the freeze-thaw cycle |
| Plastic | $500–$2,000 | Easy to install and budget-friendly | Lowest durability |
| Fiberglass | $1,200–$3,000 | Easy to install and resists cracking and algae | The most expensive tank |
Type of Septic System
There are two main types of septic systems, each with its own 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 |
Anaerobic: Anaerobic systems are more common and cost $3,000–$12,000. They’re less costly than aerobic systems and don’t need extra power or chemicals, but they’re less efficient and require a larger leach field. A pipe runs from the house to the septic tank, where another pipe runs into the leach field. Anaerobic bacteria break down solid waste before the system distributes the wastewater into the soil.
Aerobic: Aerobic septic systems utilize oxygen pumped into the tank to activate bacteria that feed on the solid waste. They’re more expensive at $10,000–$20,000 but are more efficient and work well on smaller properties. They require additional power to run, so hook yours up to a power generator in case of a power outage. Otherwise, these systems can plug into your property’s main power source.
Conventional systems are the most common in Indiana, but aren’t suitable for every property. Indianapolis has a high water table, which can require a pretreatment unit or an alternative septic system, like a mound septic system. Depending on the solution, these can cost $10,000 to $20,000.
Site Prep
You’ll need to survey your land and test the soil to make sure it has proper drainage before installing your septic system. This ensures that your design meets the environmental guidelines set by the Indiana Department of Health. Luckily, Indianapolis primarily has loam soil, one of the best soils for conventional septic systems.
Land Survey: You’ll need to get a land survey before installing a septic system to ensure your plans fall within property lines. Expect to spend $260–$1,000 to hire a licensed land surveyor.
Percolation Test: Before the installation, you need a local perc test pro to perform a percolation test. The test measures water drainage in the soil, soil type, and the height of each sediment layer on your property to determine the best type of septic system for you. The cost to test your soil is $260–$500.
Leach Field Installation: Septic tank systems consist of a septic tank and a trench referred to as a leach field or drain field. This section of the system transports the wastewater back to the soil. Drain field installation costs $5,000–$12,000.
Septic System Installation Pro Costs
In Indiana, regulations for septic systems—including who to hire for septic problems and installations—depends on the county. Some counties in Indiana allow you to get a test and install your own system if you have a passing score. Marion County isn’t one of them, so professional labor ends up being a significant part of the total cost.
Labor
Labor makes up 50% to 70% of the total cost of septic system installation. Septic system installers in Indianapolis, Indiana, are licensed by the Onsite Wastewater Professional Association (IOWPA). These licenses are accepted in several counties across Indiana.
Permits
Every year, the Indiana Department of Health issues about 15,000 permits for new septic systems and another 6,000 for septic system repairs. Depending on the scope of the job, you could spend anywhere from around $100 to more than $500.
Does a Septic System Increase Home Value?
A working and well-maintained septic system won’t increase your home value, but it won’t hurt it either. The only exception is if you live in an area that’s part of the Citizen Energy Group’s Septic Tank Elimination Program (STEP). If you still have a septic system once public sewer access is expanded and the deadline has passed, you will need to connect to the public sewer.
Your home value can be impacted negatively if your septic system is damaged, leaking, or nearing the end of its lifespan. Hire a local septic system company to keep up with maintenance and repairs, especially if you plan to sell your home.
How Angi Gets Its Cost Data
Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We survey real Angi 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.
Want to help us improve our cost data? Send us a recent project quote to [email protected]. Quotes and personal information will not be shared publicly.
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