How much does it cost to replace a septic tank in Windham County, CT?
Last updated July 10, 2026
Short answer
Replacing just the septic tank, without touching the drain field, typically costs $3,000 to $7,000 in Windham County, depending on tank size, material, and site access. A full system replacement including a new drain field runs $10,000 to $20,000.
Tank-only replacement is less common than full system replacement, since tank failure and drain field failure often happen around the same age. Concrete tanks generally cost less than plastic or fiberglass but weigh far more, which can raise installation cost on a difficult site. Permitting through the local health district is required for any tank replacement in Connecticut, and site conditions like ledge, high water table, or limited setback from wells and property lines can add cost. Get more than one quote, since site access and soil conditions vary block to block in a county this rural.