The listing says Dexter. The photos show a two-story colonial on two wooded acres, a wraparound porch, maybe a barn out back. Nothing on the listing page tells you whether that address sits inside the city limits or a quarter mile past them, out in Scio Township or Dexter Township. That distance decides whether your closing runs on schedule or stalls while a well-and-septic evaluation gets scheduled, filed, and cleared with the county.
Most buyers assume the name on the listing tells them what they're getting. In Dexter, it doesn't. The City of Dexter is a small incorporated city with its own municipal water and sewer utility. Dexter Township, the unincorporated area that surrounds it and shares its name, is mostly private well and septic. So is neighboring Scio Township. A buyer moving from a state with a statewide plumbing code has no reason to expect this. A buyer who's lived in Ann Arbor city limits their whole life has no reason to expect it either. Michigan has no statewide sanitary code at all. Septic and well regulation is written county by county, and roughly 30 to 35 of the state's 83 counties have adopted their own point-of-sale requirement. Washtenaw County is one of them, and its version is considered one of the stricter ones in the state.
Two Water Systems Under One Name
The City of Dexter runs its own water and sewer department, drawing from two well fields the city itself owns and maintains. One sits in Dexter Community Park, behind LaFontaine Chevrolet, with four wells ranging from 200 to 225 feet deep feeding a filtration plant on Central Street. The other is a single 70-foot well behind Dexter High School, off Parker Road, treated on-site before it joins the same water tower supply. The city's wastewater treatment plant discharges to the Huron River under a permit the city monitors daily.
None of that infrastructure belongs to individual homeowners. If a property sits inside the city's service area, the buyer isn't inheriting a private well or a septic tank. There's no county evaluation to schedule because there's no on-site system to evaluate.
Step outside that boundary and the picture changes. Northern Washtenaw County, including Dexter Township, Webster Township, and the unincorporated stretches around Scio Township, has sandier soils with generally good drainage, but the Huron River and its tributaries push water tables high in spots close to the river corridor. That combination is why on-site systems remain the norm out there rather than an exception waiting to be phased out. A regional guide to septic contractors serving the Ann Arbor area describes this exact pattern: municipal sewer inside the city, and thousands of homes on private wells and septic the moment you cross into the surrounding townships.
There's a wrinkle even within the townships. A joint authority called the Multi Lakes Water and Sewer Authority furnishes water and sewer service to a defined special assessment district inside Dexter and Lyndon Townships, an area first established in 1994. So a handful of township parcels are tied into shared infrastructure despite sitting outside the city limits, while most of their neighbors are on wells and tanks. The only way to know which category a specific address falls into is to ask, not to guess from the mailing address.
What Inside the City Limits Actually Means at Closing
| Inside City of Dexter | Outside city limits (townships) | |
|---|---|---|
| Water source | Municipal, two city-owned well fields | Private well on the parcel, in most cases |
| Wastewater | Municipal sewer, treated at the city plant | Private septic system, in most cases |
| Washtenaw County Time of Sale trigger | Not applicable, no on-site system | Applies before the deed can transfer |
| What the buyer inherits | A connection to an existing utility account | A physical system the buyer will maintain |
The right side of that table is where the friction lives, and it's worth understanding in detail before an offer goes in.
What Washtenaw County's Time of Sale Program Actually Requires
Washtenaw County's Time of Sale program requires an inspection of on-site well and septic systems before a home with either can be sold. In practice, that means a certified evaluator checks both systems, pumps and inspects the septic tank, draws a site plan showing where the well and septic sit relative to the house, and collects a water sample from the well for lab testing. If the property has a reverse osmosis system, an additional water sample gets pulled for that too. The completed evaluation is filed with the county, and it's valid for 12 months from the date of inspection, not indefinitely.
If there's no septic permit or site plan already on file with the county, the seller doesn't get to skip straight to a light inspection. The county requires the tank to be pumped and inspected in addition to the standard evaluation, which adds time and cost to a transaction that a seller with older records on file wouldn't face.
This isn't a box any agent can check off casually. It's a filed public record that becomes part of the transaction history for that parcel, and it's a real gate between an accepted offer and a closed deed.
The Cost and the Clock
A standard Point of Sale septic evaluation in Michigan runs roughly $200 to $450 on its own, with tank pumping (required for most Time of Sale inspections) adding another $250 to $450. A full evaluation with pumping typically lands between $450 and $900. When dye testing or hydraulic load testing is part of the scope, a complete Time of Transfer evaluation can run $300 to $700 depending on the county and what the inspector finds along the way.
In Washtenaw County transactions where the ordinance applies, the seller typically covers this cost, though like most closing costs it can be negotiated between the parties. The bigger issue for buyers and sellers alike is timing. The evaluation has to happen, get filed, and clear before the deed transfers. If it's scheduled late in a tight timeline, it can push a closing date. If the seller already has a valid evaluation on file from within the past 12 months, that step may already be satisfied, which is worth asking about the moment a Dexter-area property outside the city goes under contract.
If the evaluation turns up a failing system, the county's ordinance generally requires repair or replacement before the transfer completes, or an escrow arrangement to fund the repair after closing. FHA and VA lenders add their own layer on top of the county rule, requiring proof the system functions properly before they'll finance the purchase regardless of what the local ordinance says. A buyer using one of those loan programs on a township property should expect both requirements to apply, not just one.
A Few Questions Worth Asking Before You Write an Offer
Does the Time of Sale rule apply if the home already has city water and sewer? No. The county's on-site evaluation requirement is triggered by having a private well and septic system. A property fully connected to the City of Dexter's water and sewer utility, or to the Multi Lakes Water and Sewer Authority where that service exists, doesn't have an on-site system for the county to evaluate.
If there's already a septic permit and site plan on file, does the evaluation still happen? Yes, the Time of Sale evaluation is still required at every transfer of a property with a well or septic system. Having a permit and site plan on file with the county mainly means the seller avoids the additional step of a required tank pump-and-inspect that applies when no such records exist.
Who typically pays for the evaluation, buyer or seller? The seller typically pays when Washtenaw County's ordinance applies, though the cost can be negotiated as part of the purchase agreement like any other closing cost.
Whether a Dexter-area home comes with a private well and septic system or a straightforward connection to the city's utility isn't something a listing photo will tell you, and it changes the math on cost, timeline, and what you're agreeing to maintain after closing. If you're weighing a property near Dexter and want to know which side of that line it falls on before you write an offer, Charles by Reinhart can help you find out.
