What is a potential consequence of not properly sealing abandoned wells?

The potential consequence of not properly sealing abandoned wells is that they can become entry points for contaminants into the groundwater. When a well is abandoned and left improperly sealed, it provides a direct pathway for surface water, pollutants, and other contaminants to infiltrate the aquifer system that supplies drinking water and other uses. This can significantly degrade the quality of groundwater, potentially harming ecosystems, impacting agricultural practices, and posing health risks to humans relying on that water source.

The other choices do not accurately reflect the implications of unsealed abandoned wells. For instance, abandoned wells would not inherently increase groundwater levels; instead, they can contribute to contaminated water sources. Similarly, they do not enhance water quality; rather, they pose a risk to it. Lastly, while inefficient or improperly maintained wells could lead to changes in water usage, the key concern with unsealed abandoned wells is their potential to facilitate contamination.