Why Two Houses on the Same Exeter Street Can Be on Completely Different Water Systems Right Now

Drive down Tilton Avenue or Scammon Lane in Exeter and, as recently as this past winter, you would have passed orange cones and an open trench that closed and reopened for months. The town spent the first part of 2026 threading a new water main through a pocket of Westside Drive that had relied on private wells for decades. By the time that phase of work wraps, some of those houses will be drinking from the Exeter River and the town's groundwater plant on Lary Lane. Their next-door neighbors, on a lot the main doesn't reach, will still be on the same well they've had all along.

That is the detail buyers miss when they think about water in Exeter. It is not a fixed fact you can look up once and file away. It is closer to a status that can change mid-transaction, block by block, on a schedule the town controls and the seller may not think to mention.

The line you can't see from the curb

Exeter's municipal system covers most of the town, but "most" is doing real work in that sentence. The public water comes from a mix of surface and groundwater: the Exeter River is the primary source, backed by the Exeter Reservoir fed from Dearborn Brook, plus four named groundwater sources, Skinner Springs, the Stadium Well, the Gilman Well, and the Lary Lane well, all tied into three storage tanks and roughly 55 miles of distribution pipe, according to the Town of Exeter's own description of its water system.

Everyone outside that distribution footprint is on their own well, drawing straight from the granite bedrock that runs under most of the New Hampshire Seacoast. A buyer touring homes in Exeter's outer neighborhoods, the ones priced below the in-town Federal-style stock, is often touring a mix of the two without realizing it. The listing sheet rarely spells it out. The street name doesn't tell you either.

What's actually moving in 2026

The Westside Drive Drainage, Water and Roadway Improvements project is the clearest evidence that this line isn't static. The town held an informational meeting on the broader project on October 30, 2025, with construction starting on or around November 3, and water main installation itself beginning on Tilton Avenue and Blanche Lane the first week of January 2026. Crews moved on to Silvio Drive and Scammon Lane by mid-to-late January, then continued back on Tilton and Blanche into February. The town followed up with a March 4, 2026 meeting focused specifically on a cost-sharing program for extending drainage service onto private property, part of the same corridor already getting new water main. The work is being carried out by the town's engineering consultant, Underwood Engineers, and its contractor, N. Granese and Sons.

For a buyer, this means the well-versus-town-water status of a specific address in that corridor is a moving target, not a settled fact you can infer from the general reputation of the area. A house that was well-served when it last sold might be connected to the main by the time your inspection period closes, or it might sit on a lot the current phase doesn't touch. The only way to know is to ask the town directly about that parcel, not to assume based on what the street looked like a year ago or what a neighbor's house has.

Exeter's supply side has its own pressure worth knowing about. The town moved to Level 4 water use restrictions in September 2025 during a drought, easing only to Level 3 in July 2026 as conditions improved. Municipal water in Exeter is not a bottomless utility connection. It is a managed resource with real seasonal limits, which is part of why the town extends its mains gradually rather than everywhere at once.

The law doesn't require anyone to know

Here is the part that surprises most buyers moving from a municipal-water market. New Hampshire does not require a seller to test a private well before selling the house. State law requires two things, and neither one is a test result.

Under RSA 477:4-a, a seller has to hand the buyer a signed notification that radon and arsenic can occur in New Hampshire groundwater and that testing is recommended. It's a warning, not a report. A separate statute, RSA 477:4-d, requires the seller to disclose the well's type, its location, and the date of the most recent test, along with any known problems, if a test was ever done. If it wasn't, there's nothing on file to disclose.

Put those two rules together and you get a quiet incentive structure worth naming out loud. A seller who never tested the well is fully compliant with New Hampshire law. A seller who tested and got a bad result now has something to disclose. The path of least paperwork runs directly through not knowing, which means the absence of a water test on a listing tells you nothing about water quality and everything about what the seller chose not to find out.

What the regional numbers actually say

The odds here are not small enough to wave away. New Hampshire's Department of Environmental Services estimates that about 30 percent of the state's bedrock wells contain arsenic above the 5 parts-per-billion limit that public water systems are held to, and that roughly half of bedrock wells statewide carry radon at levels of concern. Both minerals occur naturally in the granite the wells are drilled into. Neither has a taste, smell, or color that would tip you off during a showing.

Exeter's own experience backs this up. It was one of twelve Seacoast towns in a pilot program run by the state's Seacoast Commission on Long-Term Goals and Requirements for Drinking Water, which sent NHDES staff door to door offering free well testing. Across those twelve communities, 37 percent of sampled households turned up detectable arsenic, and 28 percent exceeded the health standard for radon. Those aren't fringe results. They're closer to a coin flip on arsenic and worse than one-in-four on radon, in the exact geology a buyer touring Exeter's outskirts is standing on.

What testing actually costs against what's on the line

A water test is cheap relative to almost anything else in a home purchase. Endyne Labs, one of the accredited labs serving New Hampshire, prices a bare FHA or VA lending package at $85, covering lead, nitrate, and coliform bacteria. Their fuller home-buyer package, which adds arsenic, radon, uranium, and a broader mineral panel, runs $315. Set either number against a New Hampshire median single-family sale price near $575,000 in mid-2026, and the cost of finding out is close to a rounding error.

The reason this matters is what happens after a bad result, not before it. Arsenic and uranium respond to point-of-entry treatment systems. Radon is stripped with an aeration unit. Bacteria is usually resolved by shocking the well and retesting. None of that requires walking away from the house. It requires knowing the number early enough in your inspection period to ask the seller for a credit, a price adjustment, or an installed treatment system before you close, rather than discovering it after the moving truck leaves.

What to actually do before you write the offer

• Ask the listing agent directly whether the specific parcel is on Exeter's municipal system or a private well. Don't infer it from the neighborhood or the asking price.
• If the property sits anywhere near the Westside Drive corridor, ask the town's public works department whether that lot is scheduled for a water main connection and on what timeline.
• Request any existing well test results and their date. If none exist, treat that as missing information, not as evidence of clean water.
• Build a water test into your inspection period rather than treating it as optional. Ask for arsenic, radon, and uranium at minimum, and add a PFAS panel if the home is anywhere in southern New Hampshire, where those compounds show up more often.
• If a result comes back elevated, get a written treatment quote before you negotiate. A specific number is easier to work with than a general concern.

Frequently asked questions

Does New Hampshire require sellers to test their well before selling?

No. State law requires a signed notification that radon and arsenic can occur in New Hampshire groundwater, and it requires disclosure of any test the seller already has on file. It does not require the seller to order a new test.

If my street is part of a current or recent water main project, do I still need to test the well?

Yes, until the connection is complete and the house is actually drawing from the municipal system. Even then, ask the town for a firm connection date for your specific parcel rather than assuming a project deadline applies to every lot on the block.

Is a positive arsenic or radon result a reason to walk away from the house?

Rarely. Both are common in this bedrock and both are treatable, typically for a few hundred dollars for a basic filter up to a few thousand for a whole-house system. Most buyers use the result as a negotiating point rather than a dealbreaker.

Does any of this apply if the house is already on Exeter's municipal water?

The water quality risk doesn't, since municipal water is treated and monitored. It's still worth knowing that Exeter's public supply operates under seasonal use restrictions during dry years, most recently stepping down from Level 4 to Level 3 in July 2026, which is a fair question to ask about long-term irrigation or pool-filling plans on a larger lot.

Water status is one of the quieter details that can complicate an Exeter closing, and it's exactly the kind of thing worth catching before an offer goes in rather than during the inspection period. If you're weighing a property in Exeter or anywhere else across the North Shore or Seacoast, Jamie Frontiero can help you ask the right questions early and negotiate from a position of actual information. Let's Connect.