Septic System Costs in Montana (2026)

Based on BLS wage data, septic system in Montana costs an average of $8,159, ranging from $7,769 to $8,568.

Montana Average $8,159

Septic System Costs by City in Montana

Reviewed by

Alex Johnson, P.E.

Mechanical Engineer • 15+ Years Home Repair Experience • Licensed Contractor

All cost data on this page has been verified against BLS and Census Bureau records. See our methodology →