The well drillers drill a hole into the ground maybe with a general idea how deep based on other wells in the area. How deep and how's the water quality is an unknown. Some drilled wells have a problem with small stone particles or bad taste or radon or arsenic.
Water treatment companies like
www.culligancentralnh.com will install a treatment facility in your basement or heated garage for your well if you are not pleased with the initial faucet water after the well is first installed.
All things considered like the expense and unknown well drilling result cause people to stick with what they got for water, and go to the store for a five gal container of trusted quality water somewhat similar to the Route 3, road side Crystal Spring in south Plymouth ..... bring your plastic container(s).
Welcome to New Hampshire ...... water, water, everywhere ..... and not a drop to drink ..... or something like that! The
www.mwra.com ..... is not in N.H. ...... live free or die ...... for your water ..... you is on your own water!