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Private Well Water

Maine CDC provides free help to private well owners who have questions about their wells, water sampling, and water treatment. A "private well" is any well that is not regulated by the Maine CDC's Drinking Water Program as a Public Water System. Private wells are not regulated; property owners are responsible for testing and treating the water from private wells.

Testing Your Well Water

Many Maine residents access their drinking water from private wells, and those wells can, occasionally, contain metals or bacteria harmful to human health. Some Maine wells have too much arsenic, uranium, radon, or other harmful chemicals. The only way to know if your water is safe to drink is to test it.  

Well owners should test their private drinking water annually for coliform bacteria, E. coli, and nitrates and nitrites.  

It is also recommended that well owners test their water every 3-5 years for 

  • arsenic
  • chloride
  • copper
  • fluoride
  • hardness
  • iron
  • lead
  • magnesium
  • manganese
  • pH
  • radon
  • sodium
  • uranium

When testing your drinking water, consider using an accredited laboratory (PDF). While there are many great laboratories serving the people of Maine, benefits of using an accredited lab include known testing methods, recognized quality control and assurance practices, and regulatory access, meaning that Maine Laboratory Accreditation Officers are able to assist customers with questions concerning their water test results. 

  • If you have never tested your well water, we recommend doing a comprehensive or standard water tests for everything listed above.
  • Other times to test your well include:
    • If you are expecting a baby
    • Your water changes in smell, taste, and color
    • Your well runs dry and comes back
    • When buying a new home
    • After installing a water treatment system or replacing parts of your treatment system
    • After any work is done on your well
  • Find a lab that is certified to test your well water (PDF).
  • Find a lab certified to test water for radon

Want to talk to a well water expert?

Please contact the Maine CDC's Toxicology Team by email ehu@maine.gov or phone (207) 287-4311 to talk about:

  • What to test for and what your results mean
  • Questions about the health effects of well water contaminants

Please contact April Bledsoe by email april.bledsoe@maine.gov, or phone (207) 215-7124 to talk about:

  • General well questions – Specialty Well applications, ideal well location, and potential threats to wells and water quality.
  • Drinking water and well drilling rules, best practices, and construction standards such as casing requirements and setbacks to septic systems.
  • Sampling -  help with sample collection, guidance for laboratories
  • Water Quality Review – contaminants and the need for treatment.
  • Treatment – exposure risk assessment and treatment types to consider.
  • Disinfection advice on proper methods and products.
  • Potential conflicts between homeowners and drillers, abutting landowners, and local officials.

There is no charge for private well technical assistance; this is a free service of the Maine CDC.

Resources

Common Well Water Contaminants