City of St. Paul Park 

on the Mississippi

Unused Wells

What is an unused well--and why is it a problem?

A well that is not in use--sometimes referred to as an "abandoned" well--can be a potential threat to health, safety, and the environment.  Wells that are no longer used may be buried or forgotten.  Often they have not been sealed properly.  Sealing is the process of clearing an unused well of debris and filling the well with special material called grout.  The sealing must be done by a licensed well contractor.

Unused wells that have not been properly sealed can be a source of groundwater contamination, potentially affecting nearby drinking water wells.  They may threaten the quality of the water in city water wells, your neighbor's well, or even your own well. 

Ground water is the main source of drinking water for three out of every four Minnesotans.  Protecting groundwater is everybody's business.

As a well ages, the casing may rust, joints may leak, the pump may become stuck in the well, or the well may fill with debris.  If the well is covered with boards or concrete, the cover will eventually decay and break open.  Surface water runoff, debris, and other contaminants can then enter the well. 

A well may be taken out of service for a variety of reasons.  It may no longer provide enough water.  It may not have been repaired when it needed to be.  It may have become contaminated.  A well may be "lost" or abandoned when property changes hands. 

Old, unused wells are easily forgotten.

How do unused wells threaten the groundwater?

Groundwater is found in underground geologic formations called aquifers.  The layers of rock and soil that lie between an aquifer and the surface, or between aquifers, typically act as natural barriers against the spread of contamination.  However, an unused, unsealed well can provide an open channel between the surface and an aquifer--or between a shallow aquifer and a deeper aquifer.  An unused well an act as a drain--allowing surface water runoff, contaminated water, or improperly disposed waste to reach an uncontaminated aquifer. 

Learn more about well disclosures 

City of St. Paul Park, 600 Portland Avenue, St. Paul Park MN 55071