Estimated costs to install a septic system
If you're anxious about the cost of a septic system, you're not alone. It's the first question many homeowners ask.
Every project is different. Total costs for a new installation usually fall between $10,000 and $50,000, depending on where you live and the type of system you need.
This guide helps you understand expenses at each stage of your project — with figures for Illinois, Iowa, New Jersey, and Pennsylvania.
Remember, you don't have to plan your installation alone. Ecoflo is here to help, and the first conversation is always free.
Professional fees before installation
Before any installation work begins, there are professional services to factor into your budget. These cover the foundations of your project — understanding your site, testing your soil, and designing the right septic system for your property.
Costs at this stage vary, and it's worth understanding what each involves before committing to anything.
Site evaluation
A site evaluation is the starting point for any new septic installation.
A specialist visits your site to assess the conditions that will shape your project. They evaluate the layout of the land, setbacks from buildings and water, and any other features that could influence the type of system your property can support.
In many states, contractors bundle this service with soil testing rather than bill it separately. If charged on its own, you can expect to pay in the range of $100 to $400.
Soil testing
Before your septic system can be designed, a qualified specialist tests the ground beneath your property. In most cases, they carry out two separate tests:
- Deep probe test
A technician digs test pits to measure how deep your soil goes before hitting bedrock, groundwater, or a layer that would block proper wastewater treatment. - Percolation test (perc test)
Small holes are dug and filled with water. The technician measures the rate at which the water level drops. This figure influences the size and type of drain field your system will need.
Soil testing costs vary by state and often by county, depending on who carries out the tests and what your site requires.
Average industry cost:
- Illinois: $700 to $2,000
- Iowa: $500 to $1,500
- New Jersey: $900 to $2,000
- Pennsylvania: $1,500 to $4,500
- National average: $700 to $2,000
System design
Once your site evaluation and soil tests are complete, a septic system designer produces a full plan for your property.
The design specifies the type and size of system you need, where it will go, and how it will be configured. It forms the basis of your permit application.
Costs depend on where you live, the complexity of your site, and whether your local authority requires a licensed engineer to prepare the plans.
Average industry cost:
- Illinois: $500 to $3,000
- Iowa: $500 to $3,000
- New Jersey: $2,000 to $4,000
- Pennsylvania: $600 to $4,000
- National average: $500 to $3,000
Septic system and installation costs
The septic system itself — along with the excavation and physical installation work — is the largest single expense in most projects.
What you pay depends on two things: where you live, and what type of system your property needs. Your system type is determined by your soil conditions, lot size, and local regulations.
In the United States, most rural homeowners have land that supports a conventional septic system. For homeowners with more challenging sites, an advanced treatment system is typically required.
For conventional septic systems
A conventional system includes a septic tank and a drain field — sometimes called a leach field.
This type of system is recommended for properties with adequate space and soil that drains at an acceptable rate.
The costs below cover components for a conventional system, plus excavation, groundworks, equipment, and labor.
Average industry cost:
- Illinois: $10,000 to $18,000
- Iowa: $8,000 to $15,000
- New Jersey: $15,000 to $30,000
- Pennsylvania: $10,000 to $20,000
- National average: $8,000 to $20,000
For advanced treatment systems
An advanced system treats wastewater to a higher standard than a conventional system. It involves more components, more materials, and more installation work.
This type of system is recommended for properties with poor soil, high groundwater, shallow bedrock, or when the lot is too small for a standard drain field.
The costs below cover components for an advanced system, plus excavation, groundworks, equipment, and labor.
Average industry cost:
- Illinois: $18,000 to $35,000
- Iowa: $15,000 to $25,000
- New Jersey: $25,000 to $50,000
- Pennsylvania: $18,000 to $35,000
- National average: $15,000 to $35,000
Ongoing costs
Installing a septic system is a one-time project, but owning one comes with ongoing costs.
Regular pumping, routine maintenance, and occasional repairs are all part of life with a septic system. If yours includes a pump or aerator, electricity costs are an additional factor to build into your budget.
Most homeowners plan around $300 to $800 per year for routine costs, though this varies depending on your system type and how heavily it is used.
Not sure what to budget for your installation project?
Estimates can only tell part of the story. If you'd like a clearer picture of what your septic installation might cost, we're here to help.
