In North America, state or provincial regulations work to ensure that wells are properly drilled and do not pose a threat to valued groundwater aquifers. An important aspect of completing a well is to grout the annular space between the drilled borehole and the casing.
Drillers get a bad rap. Sure, there are bad practices in any industry. But the vast majority of people working in drilling trades know just what the impact is of every aspect of their job.