Some Nantucket houses draw town water and many draw private wells. What that difference means for a buyer, and the test the town requires before a sale.
Buyers ask me about the roof. They ask about the septic, because someone has already warned them about Title 5. They ask what the house did last winter and whether the basement takes water in a northeaster.
Almost nobody asks where the water comes from.
It is the one utility on Nantucket that changes completely depending on which side of an invisible line the house sits on, and it is the one that shows up late in a deal, usually as a lab report nobody was expecting to read.
The line ends sooner than you think
In and around Town, houses are on municipal water from the Wannacomet Water Company. You turn the tap, the water arrives, someone else is responsible for the pumps and the testing and the main under the street. It works the way water works in most of the country.
Across much of the rest of the island, it does not. Out past where the mains stop, houses draw from private wells into the same sole-source aquifer that sits under all of us. That includes a great many of the properties people fall in love with: the ones down a sand road, the ones with the long view, the ones where the nearest neighbor is a hedge away rather than a fence away. The further you get from Town, the more likely it is that the house you are looking at makes its own water.
Neither arrangement is better. They are simply different things to own, and the difference belongs in the conversation well before the inspection.
What a private well actually asks of you
A well is a piece of equipment. It has a pump, a pressure tank, a casing, and a working life. Like anything mechanical on this island, salt air and time are hard on it, and like anything mechanical on this island, replacing it is a scheduling problem as much as a money problem.
What the well gives you in exchange is independence. No water bill, no main to be shut off while the street is dug up, no rationing conversation in a dry August. Owners who have had one for years tend to be fond of it.
What it asks of you is attention. Water quality is not a fixed property of a house. It is a reading taken on a day, from a depth, under conditions, and it can move. That is the part buyers coming from a municipal system tend not to expect, because it has never once been their problem.
The test that happens before you close
Since the start of 2024, the Town has required that the water in every private drinking water well be tested before a property is sold, conveyed or transferred. It sits in Chapter 386, the Town’s wells regulation, under the water quality testing requirements.
In practice that is two separate kits, both from Health and Human Services on Pleasant Street, both analyzed by the Barnstable County lab.
The real estate kit runs the ordinary suite: total coliform, sodium, iron, copper, manganese, pH, conductance, nitrates and volatile organic compounds. The PFAS kit is its own test, ordered separately, for the per- and polyfluoroalkyl compounds that have been the island’s water story for several years now.
Then come the two numbers that decide whether this is routine or a crisis.
Samples can only be dropped off on Tuesday mornings, between 7:30 and 9:00. Not any weekday. Tuesday. Miss the window and the whole thing waits a week.
And the real estate kit takes up to fourteen business days to come back, while PFAS can take up to six weeks.
Read those together. A seller who orders the PFAS kit the week the offer is accepted may still be waiting when the closing date arrives, and a single missed Tuesday pushes everything another seven days. This is the most avoidable delay in a Nantucket transaction and I see it catch people every season. On a well property I want that kit ordered early, not at the point in the process where the septic and the inspection normally get handled.
The other thing worth saying: a result you do not like is not the end of a deal. It is a piece of information, and there is usually an engineering answer to it, filtration or treatment or in some cases a new well. What determines whether it wrecks a closing is whether anyone anticipated it. A buyer who knew this test was coming reads the report as a project. A buyer who has never heard of it reads it as a reason to walk.
I have watched both happen on the same kind of report.
What I tell buyers to ask
Before you are emotionally committed to a house, ask four things.
Is it on town water or a well? If it is a well, how old is the well and the pump, and is there paperwork? Have the pre-sale kits been ordered yet, and on which Tuesday? And if there is treatment equipment in the basement, what was it installed to treat?
That last one is the most useful question on the list. Filtration in a Nantucket basement is not a red flag. It is an answer to something, and knowing what it was answering tells you more about the property than the listing sheet will.
None of this should scare anyone off a well. Some of the best houses on this island are on one, and their owners would not trade the arrangement. It is simply a system you are taking on, the same as the heat or the septic, and it deserves the same five minutes of attention.
Water is the least glamorous thing about a Nantucket house and the one you will use every single day you are here.
If you are weighing a property and want to know what you are actually taking on, call me at 508-228-4578.