Treat the septic system like a second foundation. Get the public file, get the lids opened, and compare the house that exists today with the house the permit described. That is how buyers avoid a failed field and how sellers avoid a surprise in the inspection period.
Sellers: put a file together before the listing
- SIPH permit, as-built, and any repair permits — see how to request records
- Pump receipts with dates, tank size, and baffle notes
- Service records if the home has a treatment unit or pump
- A sketch with measurements from two house corners to each lid
If you cannot find a permit, say so. A 1968 tank does not become “new in 2005” because the listing says it. Order a pre-listing inspection and, if levels are high, a pump-out while you still control the schedule.
Buyers: do not skip the dirty work
Request the SIPH file early. Idaho gives the agency three working days to grant or deny a records request, which is not the same as having the as-built in hand before your inspection window closes. Then hire someone who will open the tank. Confirm:
- Bedroom count, plus any shop or basement plumbing, against the permitted design
- Whether the replacement area is still empty, or now sits under a garage pad
- Whether the property is close enough to a sewer main that a future repair has to connect instead of replacing the field
- Well setbacks as they were built, not as they were hoped
What we look at on a paid visit is listed on the inspection page. A letter that says “visual only, lids not pulled” is not that visit.
A pump-out at closing is not a drainfield test
Pumping at closing is useful when we document baffles and levels. It does not prove the laterals will take tomorrow’s laundry. A tank can be empty and the field still saturated. If we find surfacing effluent, you are not negotiating a landscaping credit. You are looking at a repair or replacement that needs a permit — the same checklist whether the house is in Blackfoot or on a rural lot near Aberdeen.
Tribal land and sewer districts
Fort Hall Reservation parcels follow tribal permitting — see our Fort Hall tribal permits guide. Groveland and other sewer districts sit west and around Blackfoot; some streets look rural and still have a main. Read sewer or septic before you budget a new field the city or district will not allow.