Checked against EPA SepticSmart pages and state statutes and regulations on 2026-10-07. Laws and local rules change; the current law and your local health department win.
A handful of states require a septic inspection or disclosure at sale (see the state table). Everywhere else, it's usually up to you, your lender and local rules. Either way, ask these early, while your inspection window is still open.
Ask the seller
What type of system is it: conventional tank and drainfield, an alternative system (EPA lists types such as aerobic treatment units and mound systems), or a cesspool?
Where are the tank, the lids and the drainfield? Is there a drawing on file with the county or town?
When was it last pumped and inspected? Can I see the receipts and the report?
Any backups, odors, wet spots or repairs? Were permits pulled?
For an alternative system: is there a service contract? EPA says "A service contract is important since alternative systems have mechanized parts."
Ask the inspector
Are you licensed or certified for septic inspections here (where the state requires it)?
Will you open the tank, check the drainfield, and record the sludge and scum levels?
Does your report form meet any state or local requirement for a sale?
What an inspection can't do
MassDEP's guidance for Massachusetts buyers: "The inspection does not guarantee that the system will continue to function adequately, or that the system will not fail at a later date." Records of pumping and service help fill in the history.
Well too?
If the home also has a private well, ask how far the well is from the tank and drainfield. See our well buyer checklist.
All the questions, plus forms
The checklist has the full seller, inspector and health-department question lists, an inspection-day checklist and the state rules, in one PDF.
EPA's SepticSmart pages are free (epa.gov/septic), and your state or county health department is free to call. This checklist is a paid planning guide; you don't need it to buy, sell or care for a home with a septic system.