Well Water Testing Cost: $100 to $350 (HomeGuide 2026)

National guide figures and two university lab prices. Lab and county prices vary by state.

Is it urgent? When a well water test can't wait

If a test finds E. coli or coliform, drink boiled or bottled water until the well is fixed, the Minnesota Department of Health says, but do not boil it if nitrate or arsenic was also found, because boiling concentrates them. The EPA warns that infants under six months who drink water with nitrate above the limit could become seriously ill and, if untreated, may die.

• Test now: after flooding near the well, a positive bacteria result, or a baby in the house and no recent nitrate test.
• This week: a change in taste, color or smell, or any repair or replacement of part of the well system. The CDC and EPA both list these.
• Can wait: the routine yearly test, which you can book for a set month each year.

What the CDC and EPA say about testing well water

The CDC's guidance is direct: "Test your well water at least once each year" for total coliform bacteria, nitrates, total dissolved solids, and pH, and "All well owners should test for nitrates at least once every year." It adds: "At a minimum, check your well every spring to make sure there are no mechanical problems." It also says to "Use a state-certified laboratory to test your water," and that the health department or county can give you a list.

The EPA's private well page says the same four things, testing every year for "total coliform bacteria, nitrates, total dissolved solids, and pH levels," and more often if young children, older adults, or a pregnant or nursing person lives in the home. It says to use only labs certified for drinking water, and notes your local health department may offer free private well testing. NGWA recommends testing at least annually for bacteria, nitrates, and any contaminants of local concern.

How often to test well water: what the states add

• Minnesota: coliform every year; nitrate every two or three years, or every year if it has been found, at least yearly if a past test showed 1 to 10 mg/L; and arsenic at least once in every private well.
• New Hampshire: bacteria every year, chemical testing every few years depending on the concern.
• Pennsylvania: Penn State Extension recommends a total coliform test every year.
• Massachusetts: MassDEP's private well guidelines cover building and certifying wells; ask your local board of health which tests it requires.

When to test besides the yearly check

The CDC's list of reasons to test outside the yearly check: known well problems in your area, flooding or land disturbance or waste disposal nearby, replacing or repairing any part of your well system, a change in taste, color, or smell, someone becoming pregnant, or a child coming to live with you. The Minnesota Department of Health adds a coliform test any time the well or water system is worked on, so a new pump from the well pump replacement page should be followed by a test.

Well water test cost: labs, kits and university programs

HomeGuide prices a basic lab test at $130 to $200 and well water testing in general at $100 to $350. University programs run lower: Penn State's lab charges $60 for its standard package, and Virginia's household program charges $70 per kit for 28 constituents, which it says would cost more than $300 at a private commercial lab.

Timing matters as much as price. Penn State's lab must receive bacteria samples within 30 hours of collection and returns results in about 10 to 14 business days, so collect early in the week.

Coliform in well water: what a positive result means

The EPA calls total coliforms "Not a health threat in itself" but an indicator that other harmful bacteria may be present, and says "fecal coliforms and E. coli only come from human and animal fecal waste." The Minnesota Department of Health reads a positive as a sign surface contamination may have entered the water, and Virginia's program says E. coli is the more serious result. They are common: a 2006 Penn State survey of 450 private wells found coliform in about 35 percent and E. coli in about 15 percent.

Minnesota's steps after a positive: use boiled or bottled water, disinfect the well, then retest. A well that keeps testing positive needs continuous treatment such as UV; the well water treatment page prices those systems.

Nitrate and arsenic limits for drinking water

The EPA's limit for nitrate, measured as nitrogen, is 10 mg/L. For arsenic it is 0.010 mg/L, with a health goal of zero. The CDC wants nitrate tested yearly and Minnesota wants every private well tested for arsenic at least once.

Shock chlorination of a well: when and how it is done

Penn State Extension lists three times to shock chlorinate: after a new well is built, after the well is worked on or a new submersible pump goes in, and after a positive coliform test. The Minnesota Department of Health's method calls for unopened, unscented household bleach with no additives, made within six months, at 6 or 8.25 percent sodium hypochlorite, to reach 50 to 200 ppm in the well.

• Recirculate for about 30 minutes after you first smell bleach from the garden hose, then let it stand at least two hours, preferably six hours or overnight (Minnesota).
• Do not run the chlorinated water into the septic system, landscaping or a stream. Flushing it out can take 30 minutes to 24 hours or more.
• Virginia's program recommends hiring a licensed well driller to do it.
• Set expectations: in a Penn State study, shock chlorination cleared the bacteria in only about 15 percent of wells that had it.

When to retest after shock chlorination

The two extension sources give different timing, so here are both. The Minnesota Department of Health says to retest once, between 2 and 4 weeks after disinfection. Penn State Extension says to retest about 10 to 14 days after, then again after two to three months, and that bacteria coming back means the well needs continuous disinfection.

Well inspection cost for a home purchase

HomeGuide says a well inspection covers the casing, cap and seals, the pump motor and control box, a flow test of system output and pump performance, and a written report. It takes 2 to 3 hours, lab results take 3 to 10 days, and it does not check the water table to confirm the well will last. HomeGuide says mortgage companies often require an inspection and water test before approving a loan; Virginia's program says coliform and E. coli testing is standard at a sale, and some lenders require lead and nitrate too.

Buyers usually pair it with other checks: a septic inspection for the tank and drain field, and a plumbing inspection for the pipes inside.

Well flow test and well yield test

NGWA's annual checkup includes a flow test of system output, with the water level checked before and during pumping where possible, plus the pump's amp load, grounding and voltage, the pressure tank and switch, and a coliform and nitrate test. We found no published numeric standard for how many gallons a minute a well must yield; Massachusetts requires drillers to report the flow rate and how long the pumping and recovery test ran. Ask the inspector what yield the lender or town expects.

Questions to ask before you book a well test or inspection

• Is the lab state-certified for drinking water?
• Which tests are in the price? Coliform, E. coli, nitrate, pH and TDS at minimum, plus arsenic and local concerns.
• Who collects the sample, and how fast does it reach the lab?
• Does the inspection include a flow test and a written report?
• License and insurance for anyone who opens the well. Ask the company for its well contractor or pump installer license number and proof of insurance yourself.

What to do now: get a well water test done right

1. Get the lab list from your health department or county, as the CDC suggests, and pick a certified lab.
2. Use the lab's bottles and follow its sampling sheet.
3. Ask for coliform, nitrate, TDS and pH at minimum, and add arsenic if it has never been tested.
4. Collect and deliver on the lab's clock. Penn State needs bacteria samples within 30 hours.
5. If the result is positive, switch to bottled water, plan disinfection and set the retest date.
6. Keep every result. Buyers, lenders and treatment dealers all ask for them.

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