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Abandoned Wells: Why They Must Be Properly Decommissioned

Old, unused wells are a direct route for contaminants into your aquifer. Here is why proper decommissioning matters.

By Know Your Well Water Editorial TeamReviewed October 29, 20262 min read

Quick Answer

An abandoned well is a direct pathway for surface contaminants to reach groundwater and a physical safety hazard. Unused wells must be properly decommissioned by a licensed professional, who seals the well with approved materials. Do not simply cap or fill an old well yourself.

Why abandoned wells are dangerous

A well that is no longer used but was never sealed remains an open channel from the surface straight down to the aquifer. Spills, surface runoff, and bacteria can bypass the natural soil filtration and contaminate the same groundwater that active wells, including your own, draw from. Open or weakly covered wells are also a fall hazard.

  • Provides a direct contamination route to the aquifer
  • Can affect your drinking water and neighboring wells
  • Poses a physical fall hazard for people and animals
  • May be required by law to be decommissioned when taken out of service

Decommissioning is a professional job

Proper decommissioning means sealing the well with approved grout or other materials in a specific way. This must be done by a licensed well professional, often with a permit. Simply filling it with soil or debris does not protect the aquifer.

If you find an unused well

  1. 1Keep it securely covered so no one can fall in.
  2. 2Do not dump anything into it.
  3. 3Contact your state or local well program to learn the requirements.
  4. 4Hire a licensed well professional to decommission it properly.
  5. 5Keep the decommissioning records with your property documents.

If you are buying rural property, ask whether any old wells exist on the land and whether they were ever decommissioned. An undocumented abandoned well can quietly threaten the water quality of every active well nearby.

Frequently asked questions

Can I fill in an old well myself?
No. Abandoned wells must be decommissioned by a licensed professional using approved sealing materials so the well does not become a contamination pathway. Filling it with soil or debris is not adequate.

Sources & references

This guide is documentary research and general information, not a laboratory analysis or professional assessment of your specific well. See our disclaimer.