How to Test Well Water: A Step-by-Step Guide
Nobody tests a private well for you. Here's how to do it properly: what to test for, where to send it, and how to take a sample the lab will trust.
Wondering whether you need to test at all? Read is well water safe to drink?
Step 1: Decide what to test for
| Test | When | Why |
|---|---|---|
| Total coliform (and E. coli if positive) | Every year | Shows whether germs can get into the well |
| Nitrate | Every year | Health risk, especially for babies under 6 months |
| pH | Every year | Low pH corrodes pipes and can release copper and lead |
| Total dissolved solids | Every year | A general mineral-content check |
| Iron, manganese, hardness | Before buying treatment | Decides which filter or softener you need |
| Arsenic, uranium, fluoride, radon | At least once, if common locally | Natural contaminants with health limits. Ask your health department what's common. |
| Lead and copper | If you have older plumbing or corrosive water | They come from pipes, not the well |
Not sure? Our testing schedule guide covers what to test and when.
Step 2: Choose where to test
- County or state health department. Often the cheapest, and some programs are free or subsidized.
- University extension programs. Many states run homeowner well-testing clinics.
- A state-certified commercial lab. Use EPA's list of state lab certification programs to find one.
- Mail-in lab kits sold online. Convenient, but check the lab is certified for drinking water in your state. See how to choose a test kit.
Home test strips are fine for quick screening, but they don't replace a lab test. See home kit vs lab test.
Step 3: Take the sample correctly
Bad sampling is the most common reason for a wrong result. Always follow your lab's instructions first. Typical steps:
- Use only the sterile bottle the lab provides. Don't rinse it, and don't touch the inside of the bottle or cap.
- Pick a cold-water tap that doesn't swivel, such as a bathroom sink. Remove the aerator or screen.
- Sample before any filter, softener or UV unit to test the well, or after it to test the treatment.
- Run cold water for several minutes (the lab will say how long), then fill to the line without overflowing.
- Keep it cool and get it to the lab fast. Bacteria samples usually have to arrive within about a day, so check before sampling on a Friday.
- For lead, labs often want a "first-draw" sample of water that sat in the pipes overnight. Ask.
Step 4: Read the results
Labs report numbers in mg/L (the same as ppm) or µg/L (ppb), sometimes with a pass/fail column based on public-water standards. Our guide to reading well test results explains every common line, with the EPA limit for each.
Frequently asked questions
Where can I get my well water tested for free?
Start with your county or state health department and your university extension office. Many run free or subsidized private-well testing, especially after floods or for nitrate and bacteria. Availability varies by state.
How can I test my well water myself?
You can screen it at home with test strips, but for bacteria, nitrate, arsenic and lead you collect a sample yourself in a sterile lab bottle and send it to a state-certified lab.
Who tests private well water?
You do. Private wells are not regulated under the federal Safe Drinking Water Act, and the EPA does not test homeowners’ water. You can use a state-certified laboratory, and many county health departments and extension offices run low-cost testing programs.
What should I test my well water for?
At minimum, the CDC recommends testing every year for total coliform bacteria, nitrates, total dissolved solids and pH. Add tests for what is common where you live (for example arsenic, uranium, radon or manganese) and for any symptom you notice, like stains or smells.
How much does well water testing cost?
A bacteria-only test at a public lab can cost under $50. Broader panels covering bacteria, nitrate, metals and minerals commonly cost a few hundred dollars. Prices vary by state and lab, so check your health department first.
Can I take the sample from my kitchen faucet?
Usually yes for a general test. Follow the lab’s instructions: remove the aerator, run cold water, don’t touch the inside of the bottle or cap, and sample before any filter or softener unless you are testing the treated water.
Sources
- Guidelines for Testing Well Water, U.S. Centers for Disease Control and Prevention
- Contact Information for Certification Programs and Certified Laboratories for Drinking Water, U.S. EPA
- Private Drinking Water Wells, U.S. EPA
- Should I Have My Water Tested?, Pennsylvania Department of Environmental Protection
- Public Environmental and Water Testing Prices, Wisconsin State Laboratory of Hygiene
- Secondary Drinking Water Standards: Guidance for Nuisance Chemicals, U.S. EPA
- National Primary Drinking Water Regulations, U.S. EPA
Sources checked October 24, 2026. Found an error? Tell us and we will fix it.