Well water test failed for bacteria: what to do

What does it mean if your well water test failed for bacteria?

It means coliform bacteria got into the well, and harmful germs may have come with them. Don't drink it unboiled until a follow-up test comes back clean. Ask the seller to have a licensed well contractor find the cause, fix it and disinfect the well. Then ask for a clean result from a certified lab before closing.

Key takeaways

• Your local health department may test private wells for free, so ask before you pay a lab.
• Results can run higher after several weeks of rain, so a clean retest now is not a lifetime pass.
• If disinfection keeps failing, a well contractor can run a camera down the well to find cracks.

How serious is a failed well water test?

Serious enough to stop drinking it. Vermont's health department says that if these bacteria are in your drinking water, "it is not safe to drink." When total coliform is high, the Centers for Disease Control and Prevention (CDC) says "it is likely that harmful germs" are in the water too, including certain viruses, bacteria and parasites. If the report flags fecal coliform or E. coli, CDC is blunter. That result "likely means that poop (feces), and the harmful germs in poop, have gotten into your well water."

Coliform itself is common. Vermont calls it one of the most common contamination problems in private wells. It also says a well that is properly built and maintained should be free of coliform bacteria. A positive test can point to a way in: surface water leaking into the well, or insects and animals getting inside.

Vermont's health department gives these steps for the meantime:

• Boil water for one minute before drinking, cooking, brushing teeth, or making ice or baby formula.
• Vermont says bathing is OK, but keep children from sucking on washcloths or sponges.
• Or drink bottled water, as CDC advises, or water from another safe source.

What does it cost to fix a failed well water test?

The fix is a short list: find and repair how the germs got in, shock-chlorinate the well, then retest. Vermont's order is confirm the result, inspect and repair, disinfect, then retest.

Here is the math with one local price. One $40 bacteria test to confirm the first result, plus shock chlorination at $200 to $500 from the San Diego-area contractor, comes to $240 to $540. The national guide's $150 to $1,000 shows how far that can move. A broken cap or cracked casing adds to that, and only a well contractor's written quote can size it. Other water-system lines are covered in plumbing findings on an inspection report.

The well contractor's quote is the line you can't price yet. Kept prices every line of an inspection report for $79, usually under 4 hours, and marks the ones that need a professional's quote.

Who do you call, and can you get a clean retest before your deadline?

Call a licensed well contractor for the inspection and the chlorination. Use a state-certified laboratory for the retest, as both CDC and the Environmental Protection Agency (EPA) advise. EPA adds that your local health department may test private wells for free.

Timing is the tight part. The San Diego-area contractor above leaves chlorine in the system for 12 to 24 hours, then flushes it. Vermont says to retest two to three days after the chlorine smell is gone. CostHelper says most labs mail results back within a week or two. At the long end, 24 hours plus 3 days plus two weeks is 18 days, before counting how long the smell takes to clear.

Ask the contractor and the lab for their dates before you book. If the clean result can't land before your deadline, ask your agent about extending the window in writing. For lining up quotes fast, see how to get repair estimates during the inspection period.

Could the water be making you sick?

Yes, bacteria in well water can make you sick. Fecal coliform such as E. coli "can cause stomachaches, diarrhea and other gastrointestinal diseases," Vermont says. It adds that people who drink the water for years can become immune, so visitors may get sick while the family living there does not. EPA lists recurring gastrointestinal illness as a reason to test for coliform. If you or your family feel sick, call your doctor.

How often should well water be tested?

CDC says at least once every year, for total coliform bacteria, nitrates, total dissolved solids and pH. Vermont adds that bacteria levels can rise after weeks of rain.

Are home well water test kits accurate enough?

Don't rely on a store kit for this decision. The certified lab's written result is the document to put in front of the seller, so use a lab for both the confirming test and the retest. The septic and well inspection guide covers what else a well inspection should include.

What should you ask the seller for?

Ask for the whole scope, not just the chlorine. A strong request covers four things:

• A licensed well contractor inspects the well and repairs whatever is letting bacteria in.
• The contractor shock-chlorinates the well and flushes the system.
• A state-certified lab retests for total coliform and E. coli.
• You get the clean result in writing before closing.

If you'd rather handle it yourself, ask for a credit sized from the contractor's written quote plus the lab fees. See what to ask for after a home inspection for how this fits your full list, and the buyer repair request letter template for wording.

What if disinfection doesn't work, or the seller says no?

If the seller says no, you have two options: ask for a credit sized from the contractor's written quote plus the lab fees, or use your contract's inspection terms to extend the window or step back. Your contract sets this, so confirm with your agent or attorney.

If the retest still shows bacteria, have the contractor keep looking for the way in. EPA's list of well problems to inspect for includes:

• "Cracked, corroded or damaged well casing"
• "Broken or missing well cap"
• "Settling and cracking of surface seals"

If problems continue, Vermont suggests a well contractor run a camera down the well to find cracks. It suggests permanent treatment, such as ultraviolet (UV) light, if several rounds of disinfection and an inspection do not find the cause.

EPA also warns that you "may need a new source of water or to drill a new well," depending on the contaminant, its level and the well's condition. The San Diego-area contractor above lists $12,000 to $25,000 for a complete 200 to 400 foot residential well. A number that size, or no fix you can confirm before your deadline, is a fair reason to reconsider. When to walk away after a home inspection walks through that call.

If the well is one line on a long report, upload your inspection report to Kept and put a dollar figure on the rest before your window closes.

Sources

• CDC, Guidelines for Testing Well Water
• CDC, Guidelines for Treating Well Water
• EPA, Protect Your Home's Water
• Vermont Department of Health, Coliform Bacteria in Drinking Water
• CostHelper, Cost of Water Testing and Treatment
• Well Built Florida, Chlorinating a Well: Cost Guide and Estimates
• Southern California Well Service, Well Chlorination Cost