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Printable checklist

Well water test checklist

Print it or save it as a PDF, take it to the lab, and fill in your results when they arrive.

Why and how often to test

Reviewed Oct 31, 2026 · 12 sources · How we research

1 Find a certified lab

  • Use a state-certified lab; your county or state health department should have the list.1
  • The EPA lists every state's lab-certification contact.2 Some counties test wells themselves.3
  • Don't rely on a salesperson's in-home test; confirm results with an independent lab.4

2 What to ask for

Every year1, 5, 8

  • Total coliform bacteria (with E. coli follow-up)
  • Nitrate
  • pH and total dissolved solids

At least once, then every few years3, 6, 7

  • Metals panel: iron, manganese, hardness, copper, sodium, sulfate
  • Arsenic and lead (ask for arsenic speciation if it's high)

Add these if they apply near you8

  • Farming Nitrate, pesticide scan
  • Septic system Nitrate, bacteria
  • Salted roads Sodium, chloride
  • Gas station Petroleum products
  • Gas or oil drilling Chloride, barium
  • Mining Iron, manganese, sulfate, aluminum
  • Rotten-egg smell in cold water Hydrogen sulfide (ask the lab how to sample it)

3 Taking the sample

  • Use the lab's bottles and follow its instructions exactly (where to sample, how long to run the water, how fast to ship).
  • Test again after flooding, repairs to the well, or a change in taste, color or smell.1

4 Your results

Write your numbers next to the benchmark. Federal limits are written for public water systems; for a private well they are reference points.9

TestUnitEPA benchmarkYour result
Total coliform / E. coli present / absent should be absent10  
Nitrate mg/L as N 1010  
Arsenic mg/L 0.01010  
Lead mg/L 0.015 (action level)10  
Uranium µg/L 3010  
Iron mg/L 0.3 (taste, stains)11  
Manganese mg/L 0.05 (taste, stains)11  
pH 6.5–8.511  
Hardness gpg or mg/L no limit (below 7 gpg rarely scales)12  
Chloride mg/L 250 (taste)11  
Copper mg/L 1.3 (action level)10  
Hydrogen sulfide smell / mg/L odor only11  

5 Then

Enter your numbers at wellownersguide.com/selector to see which treatment stages you need and in which order. Bacteria, nitrate above 10 or arsenic above 0.010? Talk to your county or state health department first.

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Results are in? Next steps

Sources (12) · checked Oct 31, 2026
  1. CDC: CDC, Guidelines for Testing Well Water (2024-07-01; checked 2026-10-31)
  2. EPA: EPA, Certified labs contacts (2026-08-11; checked 2026-10-31)
  3. Minnesota Dept. of Health: Minnesota DOH, Well water testing (2025-05-20; checked 2026-10-31)
  4. Penn State Extension: Penn State Ext., Tips for Buying Water Treatment Equipment (2026-07-01; checked 2026-10-31)
  5. EPA: EPA, Protect Your Home's Water (2026-02-26; checked 2026-10-31)
  6. UGA Extension: UGA Ext. Bulletin 939, Water Quality and Common Treatments for Private Drinking Water Systems (2026-07-01; checked 2026-10-31)
  7. Maryland MDE: Maryland Dept. of the Environment, Arsenic Water Treatment for Individual Wells (hosted by UMD Ext.) (Feb 2008; checked 2026-10-31)
  8. Penn State Extension: Penn State Ext., Testing Your Drinking Water (2025-06-02; checked 2026-10-31)
  9. EPA: EPA, Private Drinking Water Wells (2026-08-25; checked 2026-10-31)
  10. EPA: EPA, National Primary Drinking Water Regulations (2026-08-31; checked 2026-10-31)
  11. EPA: EPA, Secondary Drinking Water Standards (2026-05-26; checked 2026-10-31)
  12. Penn State Extension: Penn State Ext., Water Softening (2025-09-08; checked 2026-10-31)