County program status
Whether the county has a time-of-sale requirement at all, and what it requires. This determines the timeline for the whole transaction.
Michigan site work planning
Septic Inspections and Property Sales
Construction inspection and a time-of-sale evaluation are different events, with different people and different consequences.
Time-of-sale rules are county programs. Check the county before the closing date is set.
(734) 476-1098Plan the next conversation
Use the guide below to organise questions, then confirm the details for the actual parcel and scope.
Explore excavation servicesA septic inspection can mean two very different things in Michigan. During construction, the county inspects a new or replacement system before it is covered. At a property transfer, some counties operate a time-of-sale evaluation program with its own rules about who evaluates and what has to be corrected.
Confusing the two causes real problems in transactions, because the timelines and the responsible parties are different, and a failed evaluation can put a correction obligation into a closing.
This septic inspection guide separates the two, shows how to find the evaluator list for a county, and explains what typically follows a failed result. Septic inspections and property sales guide.
Construction inspection versus time-of-sale evaluation
A construction inspection is part of the permit. The county checks the installed system against the approved design before backfill, and the permit is closed when the required documentation is in. That inspection says the system was built as approved; it does not certify future performance.
A time-of-sale evaluation is a county program tied to property transfer, and it does not exist everywhere. Where a county operates one, it will specify who may perform the evaluation, what is examined, what is reported, when the evaluation must occur relative to transfer, and what happens when a system fails. Washtenaw County, for example, publishes its time-of-sale program requirements directly, and Wayne County publishes information about registered evaluators.
Neither event is a warranty. A system that passes an evaluation can still fail later, and an evaluation performed in a dry season may not reveal a field that surfaces in spring. Buyers get more value from the county's file on the parcel, the system's age, and pumping records than from the single visit alone.
What to establish early in a transaction
Who may evaluate
The county's list of registered or recognised evaluators. An inspection by someone outside that list may not satisfy the program.
System records
The county file for the parcel: original permit, as-built, system type and age, and any recorded repairs.
Maintenance history
Pumping records and any service on pumps, filters, or alarms. Gaps in history are worth asking about before closing.
Water use context
Occupancy, any additions since installation, and whether the household's flow may exceed the system's design.
Failed-result process
What the county requires when a system fails: who applies, what has to be corrected, and within what period.
A workable order for a sale
1. Check the county program first
Do this before the purchase agreement fixes a closing date, since evaluation and any correction have to fit inside it.
2. Pull the county file
Request the parcel's septic records to see what was permitted and when, and whether the system on the ground matches it.
3. Schedule with a recognised evaluator
Use the county's list, and confirm what the evaluation includes so there are no surprises about scope or access.
4. Read the report carefully
Distinguish observations from deficiencies, and ask the evaluator what would change their conclusion.
5. Plan corrections with the county
Where a repair or replacement is required, the county's permit process applies, and a credentialed installer performs the work.
Limits of this guide
Time-of-sale programs, evaluator requirements, and correction timelines are county-specific and change. Confirm the current rules with the county health department for the parcel, and do it early enough that a required correction can be scheduled.
West Branch Builders is not a septic evaluator and does not perform time-of-sale evaluations or certify system condition. Where an evaluation is required, use an evaluator the county recognises.
A passing evaluation is not a guarantee of future performance, and a system near the end of its service life can pass and then fail. Age, design, and maintenance history all belong in a buyer's assessment.
Official sources — confirm current requirements with the office named for the parcel.
- Washtenaw County time-of-sale program — Property-transfer evaluation requirements
- Wayne County septic and onsite sewage program — County application, evaluation and inspection process
- Washtenaw County certified sewage installation and repair contractors — County list of certified installers
- Oakland County onsite sewage disposal systems — County application, evaluation and inspection process
Turning this into a project conversation
If an evaluation has identified a failed field or a system that needs replacing, the next step is the county's permit process and a credentialed installer, not an immediate excavation.
Send the county, the address, the evaluation report, and the timeline you are working to. The sequence of evaluation, permit, and construction is usually what decides whether a closing date is realistic.
Related pages: Contact Us.
Questions to carry into the review
Does every Michigan county require a septic inspection when a house sells?
No. Time-of-sale evaluation is a county-level program and does not exist everywhere. Check with the county health department for the parcel early, because where a program exists it usually controls the transaction timeline.
Who is allowed to perform a time-of-sale evaluation?
Counties that run these programs generally publish a list of registered or recognised evaluators, and an evaluation by someone outside that list may not be accepted. Use the county's current list rather than a general directory.
What happens if the system fails the evaluation?
The county's process applies: typically a permit for repair or replacement, a design where the field is involved, and construction by a credentialed installer. Who is responsible, buyer or seller, is a matter for the purchase agreement, but the county controls what has to happen.
Is a passing inspection a guarantee the system is fine?
No. It records the condition observed at that visit. A system near the end of its life, or one evaluated in a dry period, can pass and then surface later. Age, design, and maintenance history are part of the picture alongside the report.