How often should a Maine well be tested?

Maine CDC recommends a coliform bacteria and nitrate test every year, and tests for arsenic, uranium, radon, and fluoride every three to five years. Those four come from bedrock, carry no taste or smell, and change slowly, while bacteria can appear in any season. Test sooner after well repairs, flooding, or any change in taste, color, or odor.

What does a well water test cost in Maine?

The state lab's comprehensive private well kit has recently been listed at about $147, with single tests like arsenic near $32 and radon in water near $42. Certified private labs set their own prices, often in a similar band for comparable panels. Prices change, so check the current listing before you order.

Are hardware store test strips good enough?

Strips can flag gross problems like very hard water, but they cannot see arsenic at 10 ug/L and cannot measure radon at all. No buyer, lender, or treatment installer will act on a strip. Health decisions and equipment sizing both need a certified lab report with real numbers on it.

Do I have to test my well when selling a Maine home?

Maine law does not force a test, but sellers must disclose the water system, known malfunctions, the date of the most recent water test, and any unsatisfactory result on the property disclosure statement. Buyers and loan programs then often require a fresh test anyway, so most transactions end up getting one.

What should I do with a result over a guideline?

Confirm it first: a single bacteria hit is handled differently from a confirmed one, and treatment gets sized from verified numbers, not from one surprising line. Then match the fix to the analyte: reverse osmosis or whole-house media for arsenic, aeration for radon, UV for bacteria. Our results guide walks through each line.

The entry point for every well problem

Well water testing in Maine

Nobody inspects a private well in Maine. No agency schedules its tests, flags its arsenic, or mails a reminder. About half of Maine households drink from a well, per the Maine Geological Survey, and each of those wells gets tested only when its owner decides to test it.

This page covers what the Maine CDC says to test and when, where the state and private labs are, what a kit costs, what happens during a home sale, and what to do with the report when it comes back.

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The Maine CDC cadence

Recommended schedule for private wells, per the state lab.

Test	How often
Coliform bacteria	Every year
Nitrates	Every year
Arsenic	Every 3 to 5 years
Uranium	Every 3 to 5 years
Radon in water	Every 3 to 5 years
Fluoride	Every 3 to 5 years

The full checklist, with the reasons behind it, is in the testing recommendations guide.

What to test, and when the schedule moves up

The cadence above splits into two groups for a reason. Bacteria and nitrates reflect what is happening at the surface: a cracked cap, a shifting casing seal, runoff finding a path. They can change in a single wet spring, so they get a yearly check. Arsenic, uranium, radon, and fluoride come out of the bedrock itself. They move slowly, but they are invisible, tasteless, and common enough in Maine that the Maine CDC puts them on every well owner's list every three to five years.

Move the schedule up when something changes: work done on the well or pump, a flood or long power outage, a new baby or pregnancy in the house, a neighbor's bad result, or any shift in taste, color, or smell. And if your area sits near a licensed sludge or septage land-application site, the state runs a separate free program for PFAS, covered on the PFAS page.

The state lab: HETL in Augusta

Maine runs its own public lab, the Health and Environmental Testing Laboratory (HETL), at 221 State Street in Augusta, reachable at (207) 287-2727. The process is built for homeowners: order a kit from the state's online test kit shop, and bottles arrive by mail with instructions and a request form. You fill them at an inside tap, ship or drive them back, and the report follows.

HETL's comprehensive private well kit, the panel Maine CDC points first-time testers toward, has recently been listed at about $147. Single-analyte tests run less: arsenic around $32, radon in water around $42. Prices change, so treat those as a scale, not a quote, and check the shop listing when you order. Against the cost of any treatment system the results might justify, the panel is the cheap step.

Certified private labs

A statewide list of certified labs is published by Maine CDC. Several private labs handle most of the residential work, often with faster turnaround and local drop-off:

Lab	Location
A and L Laboratory	Auburn
Northeast Laboratory Services	Winslow
Nelson Analytical	Kennebunk
Maine Environmental Laboratory	Yarmouth

Call ahead for panels, prices, bottle pickup, and sample deadlines. Bacteria samples in particular have short hold times.

Testing when a house changes hands

Maine's property disclosure law, Title 33, section 173, requires sellers of homes with a private water supply to disclose the system's type and location, any known malfunctions, the date of the most recent water test, and whether any test came back unsatisfactory. Sellers must also give buyers state information about arsenic in private water supplies. None of that forces a new test, but it puts the water on the table, and buyers' agents and loan programs usually take it from there with a test as a condition of sale.

For buyers, the test is leverage and protection at the same time: a confirmed arsenic or radon number can become a price adjustment or a treatment credit before closing rather than a surprise after. Maine CDC publishes real estate guidance for radon in water around its 4,000 pCi/L guideline. The full playbook, including which panel to order and when in the process to order it, is in the buying a home with a well guide.

How results come back, and what to do with them

A certified lab report lists each analyte with your measured number, its unit, and the standard or guideline it is judged against: 10 ug/L for arsenic, 4,000 pCi/L for radon in water, 0.3 mg/L for manganese, and so on, per the Maine Tracking Network's guideline table. Reports arrive by mail or email depending on the lab. Bacteria results are usually reported fastest, since a positive needs prompt action.

A line over a guideline is a treatment conversation, not an emergency. Our results explainer walks the report line by line in plain language. From there, each problem has its own page: arsenic, radon in water, bacteria and UV, and iron and manganese.

Want the sampling handled for you?

Plenty of owners order the kit and do it themselves. Others want a professional to pull the samples, especially for a real estate deadline where chain of custody and hold times matter. Tell us your town and situation and we connect you, free, with an independent local professional who samples and tests wells for a living.

If the report is already in hand, say so in the form: a treatment quote built from your actual numbers is one conversation away. How the free matching works is on the how we make money page.

Questions Maine well owners ask

How often should a Maine well be tested?: Maine CDC recommends a coliform bacteria and nitrate test every year, and tests for arsenic, uranium, radon, and fluoride every three to five years. Those four come from bedrock, carry no taste or smell, and change slowly, while bacteria can appear in any season. Test sooner after well repairs, flooding, or any change in taste, color, or odor.
What does a well water test cost in Maine?: The state lab's comprehensive private well kit has recently been listed at about $147, with single tests like arsenic near $32 and radon in water near $42. Certified private labs set their own prices, often in a similar band for comparable panels. Prices change, so check the current listing before you order.
Are hardware store test strips good enough?: Strips can flag gross problems like very hard water, but they cannot see arsenic at 10 ug/L and cannot measure radon at all. No buyer, lender, or treatment installer will act on a strip. Health decisions and equipment sizing both need a certified lab report with real numbers on it.
Do I have to test my well when selling a Maine home?: Maine law does not force a test, but sellers must disclose the water system, known malfunctions, the date of the most recent water test, and any unsatisfactory result on the property disclosure statement. Buyers and loan programs then often require a fresh test anyway, so most transactions end up getting one.
What should I do with a result over a guideline?: Confirm it first: a single bacteria hit is handled differently from a confirmed one, and treatment gets sized from verified numbers, not from one surprising line. Then match the fix to the analyte: reverse osmosis or whole-house media for arsenic, aeration for radon, UV for bacteria. Our results guide walks through each line.