Septic Inspection Checklist for a Home Sale

Real Estate Transaction Information, Not a Paid Referral

We do not accept payment for real estate transaction inspection referrals. For an inspector, use the DSPS credential lookup or call your county.

DSPS POWTS program

A real estate septic inspection is more thorough than a routine maintenance check, and it produces a written report a lender, attorney, or buyer will actually rely on. This checklist covers what typically gets checked and what tends to slow a closing down when it does not go well.

Before the inspector arrives

Locate the septic tank and drainfield on the property, or find the original permit if you have it.
Clear access to any risers or lids, digging adds cost and time to the visit.
Pull any maintenance records: past pumping receipts, county maintenance reports.
Confirm with your county whether the system is current on its maintenance cycle, see your county's page on this site.

What gets checked

Item	What the inspector looks for
Tank and baffles	Cracks, corrosion, missing or damaged inlet/outlet baffles
Sludge and scum level	How full the tank is, whether pumping is needed before closing
Drainfield surface	Ponding, surfacing effluent, unusually lush or dead grass over the lines
Flow or hydraulic load test	Whether the system handles typical household flow without backing up
Pump and controls, if present	Float switches and alarm on a mound, at-grade, or aerobic system
Camera scope, if recommended	Line condition between the house and tank, usually an add-on, not automatic

SPS 383.55Verified Sep 2026

A maintenance report gets filed to the county after the inspection event, generally within 30 days. Confirm your inspector files it, since a real estate inspection can also satisfy the county's ongoing maintenance obligation.

Read the code at docs.legis.wisconsin.gov

Red flags that tend to stall a closing

Surfacing or ponding effluent over the drainfield, a sign the field has failed or is failing.
A cracked tank or missing baffle, which usually means repair or replacement before closing, not just pumping.
No county record of the system at all, which can mean an undocumented or unpermitted system.
A tank the inspector cannot fully assess because access is buried or blocked.

None of these automatically kill a sale, but they change the negotiation. Get the written report before agreeing to a price adjustment or repair credit, not a verbal summary at the tank.

After the inspection

Ask for the written report in a form your lender or attorney will accept, and confirm whether the inspector filed the county maintenance report as part of the visit. If repairs are recommended, get a second opinion before agreeing to a large credit, since the fix, camera-scope confirmed, is sometimes smaller than the inspector’s worst-case language implies.

Frequently asked questions

Is this checklist the same as a routine maintenance pump-out: No, it is more thorough. See septic inspection cost in Wisconsin for how the two differ in scope and price.
Who pays for the inspection: Negotiable, but the buyer commonly pays in much of Wisconsin. Put it in the offer in writing either way.
What if the report finds a real problem: It becomes part of the negotiation: repair before closing, a price credit, or in some cases the deal falls through. A written report with photos is worth more in that negotiation than a verbal summary.