Every piece of well water advice ends with "get it tested". Very little of it explains who should do the testing, and the gap matters — because the most heavily marketed water test in America is not a test at all.
The four things called a water test
1. A state-certified laboratory. Accredited for specific methods and contaminants, with documented procedures and quality control. This is what "get it tested" means. A certified result is the one a lender, a health department, a buyer or a court will accept.
2. A mail-in kit from a certified lab. The same thing with better packaging. You collect, you ship, the lab runs it. Convenient and perfectly legitimate — as long as the lab behind the kit is certified, which is worth checking rather than assuming.
3. Home test strips. Useful, limited. Good for hardness, pH and chlorine; some give a rough nitrate indication. Cheap enough to use often, which makes them genuinely valuable for watching a trend between real tests. They do not reliably detect bacteria, arsenic or lead at health-relevant levels, and no decision should rest on one.
4. The free in-home analysis. This is a sales appointment. Someone who sells treatment equipment measures hardness, pH and total dissolved solids with a handheld meter, often with a demonstration involving a colour change or a precipitate.
That last one is not a scam exactly — the hardness number is probably roughly right. But it tests none of the things that can hurt you, it is performed by someone whose income depends on the conclusion, and the resulting "report" is not a result anyone will accept. Treat it as marketing, because that is what it is.
Finding a certified lab
Three routes:
- Your state environmental or health agency publishes a list of laboratories certified for drinking water analysis. This is the authoritative source.
- Your county health department will point you at that list, and often has local knowledge about which labs are good to deal with.
- The EPA Safe Drinking Water Hotline — 800-426-4791 — can direct you to your state certification officer.
Many county health departments also run subsidised testing for private wells, particularly for bacteria and nitrate. Worth asking before paying commercial rates.
What to ask before you pay
- "Are you certified for drinking water in this state, for the contaminants I am asking for?" Certification is method-specific. A lab can be certified for bacteria and not for arsenic.
- "What is your reporting limit for each contaminant?" This one matters more than people realise — see below.
- "What containers and preservatives do you supply, and what is the holding time?"
- "How long until results, and in what format?"
- "Do you interpret the results, or just report numbers?" Some labs include plain-English interpretation; some give you a grid and nothing else.
The reporting limit question
This is the detail that quietly ruins results.
"Non-detect" does not mean zero. It means the contaminant was not found above the laboratory's reporting limit — the lowest concentration that method can reliably measure.
If the reporting limit is higher than the health standard, a non-detect tells you nothing useful. A lead result of "<0.020 mg/L" is technically a non-detect, but the action level is 0.015 mg/L, so the water could exceed the limit and still report as not detected.
Check the reporting limit against the standard before you relax. If it is too high, ask the lab for a lower-level method — most have one, at a higher price.
What to test, and how often
Every year, always: total coliform bacteria and nitrate. Cheap, they change with the seasons, and they are the two that can hurt someone this month.
Every three to five years: a comprehensive panel — metals, minerals, pH, hardness, plus whatever your region is known for.
Once, or when circumstances change: arsenic, uranium, radon, fluoride, and the regional specialities. These come from geology and are generally stable.
When something specific prompts it: PFAS if you are near a known source, VOCs if there is fuel or solvent history nearby, pesticides if you are near cropland.
Our testing schedule guide has the full calendar, including the events that mean test now rather than next year.
Collecting a sample that means something
The best lab in the country cannot fix a bad sample.
- Use the containers the lab sent. Do not rinse them — several contain preservative.
- Follow the flush instructions exactly, and know which you need. Lead and copper want a first-draw sample from a tap that has sat overnight. Most other parameters want a flushed sample. Get this backwards and your result answers a different question.
- Remove aerator screens where the lab says to, and sanitise the tap for bacteria sampling.
- Do not sample from a treated tap unless you are deliberately testing the treatment — a softener or filter upstream changes what you are measuring.
- Keep it cold and get it there fast. Bacteria samples have short holding times, often around 24 to 30 hours. A sample collected Friday afternoon that sits in a truck over the weekend is not a result.
- Record the date, the tap, and whether it was first-draw or flushed. A result without that context is much harder to interpret later.
Keep every report
One report is a snapshot. Several are a record — the thing that tells you whether nitrate is creeping upward as the farm upstream expands, whether the filter you installed is still working, and whether the water was always like this or changed after the drought.
That archive is also what a buyer, a lender or a health inspector will ask you for, and it is worth more than any single number inside it.
Frequently Asked Questions
Does my water testing lab need to be certified? For anything you will act on, yes. State-certified laboratories are accredited for specific methods and contaminants, and a certified result is the one a lender, health department or buyer will accept. Uncertified results can be fine for curiosity but carry no weight.
How do I find a certified water testing lab? Start with your state environmental or health agency, which publishes a list of laboratories certified for drinking water in your state. Your county health department can point you to the right list, and the EPA Safe Drinking Water Hotline on 800-426-4791 can direct you to your state certification officer.
Are free water tests from treatment companies reliable? They are sales tools rather than tests. A free in-home analysis typically measures hardness, pH and total dissolved solids with handheld equipment, by someone who sells treatment equipment. It tells you nothing about bacteria, nitrate, arsenic or lead, and it is not a result anyone will accept.
Are home test strips worth using? For trends and reassurance between real tests, yes. For decisions, no. Strips are useful for hardness, pH and chlorine, and some give a rough nitrate reading, but accuracy is limited and no strip reliably detects bacteria, arsenic or lead at health-relevant levels.
How much does a water test cost? A basic bacteria and nitrate test is typically modest, while a comprehensive panel covering metals, minerals and regional contaminants costs considerably more. Specialist analyses such as PFAS, VOCs or pesticides are priced separately and are usually the most expensive items on the menu.