2020 Septic Tank System Installation Costs & Replacement ...
Septic Tank System Cost. A new septic tank system costs $3,918 to install on average, with prices ranging from $1,500 to upward of $5,000.Most homeowners spend between $3,280 and $5,040 for a 1,250-gallon system that supports 3 or 4 bedrooms. Septic system installation with two alternating pumps costs $9,571 on average and can go up to $15,000.