Septic System Cost Calculator
It answers one question well: what size septic system does this house need, and what will it cost. The calculators work from published state minimums and standard onsite wastewater engineering practice — two-day retention for tank volume, soil application rates for absorption area, solids accumulation for pump intervals.
State minimum tank sizes and design flow rates are compiled from state onsite wastewater codes. Soil application rates follow conventional trench loading practice. Cost ranges are built from typical component and labour costs adjusted by regional index, and are estimates rather than quotes.
It is not a system design and it does not replace a soil evaluation, a licensed designer, or your local health department. County rules sit on top of state minimums and are frequently stricter. Every figure here should be confirmed locally before money is spent.
Corrections to state data are welcome and taken seriously. If a figure on your state page is out of date, tell us and cite the code section.