The answer to 'how much does septic tank cost in Illinois' is that the cost of a septic tank system can vary widely depending on several factors. In general, the typical range for a new septic tank installation in Illinois is between $5,000 to $20,000, with most homeowners spending around $10,000 to $15,000.
The cost is influenced by the size of the septic tank, the type of system (conventional or alternative), the soil conditions, the accessibility of the installation site, and any necessary permits or inspections required by local authorities. Homeowners should also factor in the cost of regular septic tank pumping and maintenance, which can add several hundred dollars per year to the overall expenses.