Disclaimer

The calculators, charts and guides on this site provide planning estimates only. They are not a septic system design, an engineering opinion, or a code determination.

Always required

A soil evaluation or percolation test on the actual site, a design meeting local rules, a permit from your county or district health department, and inspection before backfill. Nothing on this site substitutes for any of those.

Local rules control

State figures shown here are minimums. Counties, health districts, watershed authorities and homeowner associations can and do require more. Where they differ from anything on this site, they control.

Health and safety

Septic tanks contain gases that can be fatal within seconds. Never enter a tank, and never leave a lid unsecured. Surfacing sewage is a health hazard — contact your health department.