Private well guide

Well Water in Maine: Testing, Rules, Labs and Licensed Contractors

264,198 households in Maine 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
135Licensed contractorschecked against state records
12Certified labsfrom the state certified list
16Counties covered
264,198Households on wells50% of households (est.)

Half of Maine’s households, about 264,000 of them, drink from a private well, the highest share of any state in the country, and in Waldo, Lincoln, Oxford and Hancock counties it is two thirds or more. Nearly all of those wells are drilled into granite and schist, which is why arsenic, radon and uranium are the tests that matter here, and why the state sells a cheap kit that covers all three.

Who is in charge of a Maine well

The Maine Water Well Commission, run out of the Maine CDC Drinking Water Program, licenses the drilling companies and the individual drillers, pump installers and geothermal installers, writes the construction rules and takes complaints. There is no state permit for a household well and no state inspection; the driller sends a well completion report to the Maine Geological Survey, whose well database now holds nearly 100,000 records searchable by town and map. Water quality belongs to the owner, with Maine CDC’s Health and Environmental Testing Laboratory in Augusta providing the standard test kit and the interpretation.

What is required, and what is left to you

A licensed company and driller, construction to the Commission’s rules, and the setbacks in the plumbing and wastewater codes. Maine does not require a water test on a new well or when a house is sold, though the seller’s disclosure asks when the well was last tested. Maine CDC’s advice is bacteria and nitrate every year and arsenic, uranium, radon, fluoride and manganese every three to five years, and after any well work or hydrofracturing.

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 drilled by a Maine licensed well drilling company using a licensed driller, to the Commission's construction rules (steel casing at least 20 ft and seated into bedrock, a sanitary cap, and a well cap above grade), and sited under the subsurface wastewater rules (100 ft from a septic disposal field, 50 ft from a septic tank). The driller files a well completion report with the Maine Geological Survey. A few towns require a bacteria test before a certificate of occupancy, and lenders usually do.

Water test when a home is soldNot required statewide

No statewide requirement. Maine's residential property disclosure form asks whether the water supply is a private well, when it was last tested and whether any test found a problem, so a recent test is expected in practice, and FHA, VA and USDA loans normally require a bacteria, nitrate and lead sample from an accredited lab before closing.

What the state recommends

Maine CDC recommends testing a private well every year for coliform bacteria and nitrate, and every three to five years for arsenic, uranium, radon, fluoride and manganese, the five contaminants Maine's bedrock wells carry most often (about one in ten wells is over the arsenic standard, and radon in water is higher in Maine than almost anywhere in the country). The standard Maine well water kit covers all of these plus lead, iron, hardness and pH. Test again after flooding, well work, hydrofracturing or a change in taste, color or smell.

Free or low-cost testingAvailable

No statewide free program, but a cheap and simple one: the state Health and Environmental Testing Laboratory in Augusta sells the standard well water kit through town offices, plumbing supply stores and by mail, with the bacteria, nitrate, arsenic, uranium, fluoride and metals panel for well under $100 and radon as an add-on, and Maine CDC explains the results. Several counties and tribal health programs run periodic free arsenic screening.

What the water is like

Maine’s bedrock wells draw from fractures in granite, schist and gneiss, usually 200 to 400 feet down, and the rock leaves its mark. Arsenic is the headline: roughly one well in ten is over the federal standard, concentrated in a belt from Augusta and the midcoast up to Bangor and in parts of southern Maine, with no taste or color to warn you. Radon dissolved in water is higher in Maine than almost anywhere in the country, especially in the granitic southwest, and uranium follows the same rock. Manganese, iron and fluoride are common enough that the state kit tests for them, and hardness varies by fracture. Dug and shallow wells are the ones that fail bacteria and nitrate; along the coast and near highways, chloride from seawater and road salt creeps in. Central Maine adds PFAS from decades of sludge spreading on farmland, and the state is still mapping it.

Accredited labs and the state test kit

Maine accredits drinking water laboratories test by test, and the in-state commercial list is short: a dozen labs from Kennebunk to Presque Isle, three of them PFAS-only and two bacteria-only. For most owners the route is the state Health and Environmental Testing Laboratory kit, sold through town offices and plumbing suppliers and mailed back to Augusta, which covers the whole Maine panel in one box. Every lab below comes from the Maine CDC list updated May 2026.

12 certified labs

See all 12 certified labs in Maine

Licensed well drilling companies, drillers and pump installers

Maine licenses both the company and the individual. Every profile below is built from the Water Well Commission’s lists dated July 2026: the licensed well drilling companies, with the master and journeyman drillers and pump installers who work for them named and their grades shown (apprentices are counted), plus licensed masters and journeymen who work on their own. Where the Maine Geological Survey database has reports under the company’s name, the profile shows how many wells it has filed since 2016, the counties it works in and the typical depth and yield of its wells.

135 licensed contractors

A-Z Water Systems Inc

Verified license

New Gloucester, ME · Cumberland County

License WDC0279, WD00279, WD02213, WD02326, WD02428, WD02428 Active

  • Geothermal
  • Pump Installation
  • Pump Repair
  • Well Abandonment
  • Well Drilling
  • Well Repair

Affordable Well Drilling Inc

Verified license

Sabattus, ME · Androscoggin County

License WDC0010, WD00429, WD00014, WD00419, WD00382, WD02212, WD00388, WD02371, WD00412, WD02249, WD00429, WD02212, WD02371, WD02249 Active

  • Geothermal
  • Pump Installation
  • Pump Repair
  • Well Abandonment
  • Well Drilling
  • Well Repair

See all 135 licensed contractors in Maine

By county

Well use runs from a third of homes in York County and 40% in Knox and Cumberland to two thirds in Washington, Hancock, Oxford and Lincoln and 76% in Waldo. Each county page carries its well population, the typical depth of domestic wells in the state database, the nearest accredited labs and the licensed contractors based there.

Maine well water questions

Do I need a permit to drill a well in Maine?

Not from the state. The company and the driller must be licensed by the Maine Water Well Commission, the well must meet the Commission’s construction rules and the setbacks from your septic system, and the driller files the completion report. Some towns require a permit or a bacteria test before occupancy.

Is a water test required when I sell my house?

No. Maine has no statewide requirement, but the property disclosure form asks when the well was last tested and what it found, and government-backed mortgages require a bacteria, nitrate and lead test before closing.

How do I find the record for my well?

Search the Maine Geological Survey well database by town, address or map. Records go back to the 1970s and show the driller, depth, casing length, yield and the depth of the water-bearing fractures.

Where do I get the state test kit?

From your town office, many plumbing and hardware stores, or by calling the Health and Environmental Testing Laboratory at (207) 287-2727 to have one mailed. Fill the bottles as instructed and mail or drop them back to Augusta; results come with Maine CDC’s interpretation.

My well has arsenic. Can it be fixed?

Yes. Most Maine owners install a point-of-use reverse osmosis unit under the kitchen sink for drinking and cooking water, or a whole-house adsorption system if the level is high; both need a yearly test to confirm they are working. Maine CDC’s private well program can walk you through the choice.