Private well guide

Well Water in New Hampshire: Testing, Rules, Labs and Licensed Contractors

198,872 households in New Hampshire get their water from a private well. Here is what the state requires, where to get it tested, and who is licensed to work on it.

Find a certified labLicensed contractorsPick my county
172Licensed contractorschecked against state records
10Certified labsfrom the state certified list
10Counties covered
198,872Households on wells37% of households (est.)

About 199,000 New Hampshire households, 37% of the state, drink from a private well, and in Rockingham, Cheshire and Carroll counties it is close to half. Nearly all of those wells are drilled into granite and metamorphic bedrock, which is why arsenic, radon and uranium are the tests that matter here, why the state set its own arsenic limit at 5 parts per billion, and why the state lab sells a single kit that covers all of it.

Who is in charge of a New Hampshire well

The Water Well Board, run out of the NHDES Drinking Water and Groundwater Bureau, licenses water well contractors, pump installers and technical drillers, writes the construction rules and takes complaints. There is no state permit for a household well and no state inspection; the contractor sends a well completion report to NHDES within 90 days, and the Water Well Inventory now holds records for more than 100,000 wells, searchable on the state’s well map. Water quality belongs to the owner, with NHDES’s private well program and the NH Public Health Laboratories in Concord providing the Standard Analysis kit and the interpretation.

What is required, and what is left to you

A licensed contractor, construction to the Board’s rules, the setbacks in the septic and subdivision rules, and the completion report. New Hampshire does not require a water test on a new well or when a house is sold, though many towns want a bacteria test before occupancy and the seller’s disclosure must state when the well was last tested and what it found. NHDES’s advice is the Standard Analysis before a new well is used and every three to five years after, bacteria and nitrate every year, and a test after any well work.

At a glance

Water test for a new wellNot required statewide

No statewide water test and no state permit for a household well. The well must be constructed by a New Hampshire licensed water well contractor to the Water Well Board's rules (steel casing seated into bedrock or at least 20 ft, a watertight cap 12 inches above grade, and the setbacks in the subdivision and septic rules, 75 ft from a leach field for most lots), and the contractor files a well completion report with NHDES within 90 days, which puts the well in the state Water Well Inventory. Most towns require a bacteria test, and some a full Standard Analysis, before a certificate of occupancy; NHDES recommends the Standard Analysis on every new well before it is used.

Water test when a home is soldNot required statewide

No statewide requirement. RSA 477:4-c requires the seller to disclose the well's location, type, malfunctions and the date and results of the most recent water test, so buyers routinely test as a contingency, and FHA, VA and USDA loans require a bacteria, nitrate and lead sample from an accredited lab. Radon and arsenic are the results that most often hold up a New Hampshire closing.

What the state recommends

NHDES recommends the Standard Analysis every three to five years and bacteria and nitrate every year, plus a test after any well or plumbing work, flooding or a change in taste, color or smell. The Standard Analysis from the state lab covers bacteria, nitrate, nitrite, arsenic, uranium, fluoride, chloride, copper, iron, lead, manganese, sodium, hardness, pH and radon. New Hampshire uses its own arsenic standard of 5 ppb, half the federal limit, and NHDES also suggests a one-time PFAS test for wells in the southern tier and near known contamination.

Free or low-cost testingAvailable

No statewide free program. The NH Public Health Laboratories in Concord sell the Standard Analysis kit for a modest fee (the radon vial is a separate sample), picked up at the lab or mailed, and NHDES interprets the results through its Be Well Informed web tool. Towns and regional planning commissions periodically run subsidized arsenic and radon screening, and the state has paid for PFAS sampling of wells near known sources.

What the water is like

New Hampshire’s bedrock wells draw from fractures in granite, schist and gneiss, usually 300 to 500 feet down, and the rock is the story. Arsenic is the headline: across the state about one well in eight is over New Hampshire’s 5 ppb standard, and in the southeast, from Nashua and Manchester out to the Seacoast, it is closer to one in five, with no taste or color to warn you. Radon dissolved in water runs high across the granitic Monadnock region and the southeast, and uranium follows the same rock. Manganese, iron and fluoride are common enough that the state kit tests for them. Dug and shallow wells are the ones that fail bacteria and nitrate; along the interstates and in the southern tier, road salt pushes sodium and chloride up. Southern Hillsborough County adds PFAS from the Saint-Gobain plume, and the state has drawn a consent decree boundary around it with free hookups and treatment for the wells inside.

Accredited labs and the state test kit

NHDES accredits drinking water laboratories through NHELAP, and the in-state list that takes homeowner samples is short: eight commercial labs from Lebanon to Portsmouth, one of them radon only, plus the NH Public Health Laboratories. For most owners the route is the state lab’s Standard Analysis kit, ordered by phone or picked up in Concord, mailed back with the radon vial as a separate sample, and interpreted through NHDES’s Be Well Informed tool. Every lab below comes from the NHELAP accredited laboratory search of September 2026.

10 certified labs

See all 10 certified labs in New Hampshire

Licensed water well contractors and pump installers

New Hampshire licenses the business, by method: a water well contractor license names the construction methods the company may use (rotary drilling, cable tool, dug wells, driven points), and a pump installer license covers domestic or commercial pump work. Every profile below is built from the Water Well Board’s Find a Contractor registry as of September 2026, showing which licenses the business holds and for which methods, whether it also holds a technical (monitoring well) driller license, and whether the Board has a complaint on file. About a fifth of the licensed businesses are based over the line in Massachusetts, Vermont and Maine and work into New Hampshire.

172 licensed contractors

See all 172 licensed contractors in New Hampshire

By county

Well use runs from 28% of homes in Strafford and Hillsborough counties, where the cities are on public water, to 44% in Carroll and 47% in Rockingham and Cheshire. Each county page carries its well population, the typical depth of domestic wells in the state inventory, the nearest accredited labs and the licensed contractors based there.

New Hampshire well water questions

Do I need a permit to drill a well in New Hampshire?

Not from the state. The contractor must be licensed by the Water Well Board, the well must meet the Board’s construction rules and the setbacks from your septic system and lot lines, and the contractor files the completion report with NHDES within 90 days. Some towns require a permit or a water test before occupancy.

Is a water test required when I sell my house?

No. New Hampshire has no statewide requirement, but RSA 477:4-c makes the seller disclose the date and results of the last water test, and government-backed mortgages require a bacteria, nitrate and lead test before closing. Most buyers order the Standard Analysis plus radon as an inspection contingency.

How do I find the record for my well?

Search the NHDES well map (OneStop Water Well Inventory) by address or map. Records for wells drilled since 1984 show the contractor, depth, casing length, yield and the depth of the water-bearing fractures; older wells were often never reported.

Where do I get the state test kit?

From the NH Public Health Laboratories at 29 Hazen Drive in Concord, by calling (603) 271-3445 to have one mailed, or through many town health officers. Fill the bottles as instructed, keep the bacteria sample cold and mail or drop it back within the holding time; enter the results in NHDES’s Be Well Informed tool for an interpretation and treatment advice.

My well has arsenic or radon. Can it be fixed?

Yes. For arsenic most New Hampshire owners install a point-of-use reverse osmosis or adsorption unit under the kitchen sink, or a whole-house adsorption system if the level is high. Radon in water is removed by an aeration unit or, at moderate levels, a large carbon tank. Both need a yearly test to confirm they are working, and NHDES’s private well program can walk you through the choice.