The grandparents water stinks like rotten eggs but tastes great and it seems to be some component of how that side of the family lives past 100 consistently. They’re on the border of W.VA. up in Rockingham Co. Up the mountain at the cabin it’s been spring water forever, and that water is so good I used to bring it home to northern VA to drink and make coffee because our well water there tasted like sucking rusty nails.
Rotten egg smell is from sulfur deposits in the bedrock.
I have lived in three different houses with drilled wells here in NH. They have all had hard water to some extent. Typically calcium and iron. My previous house’s water would turn the toilets/shower heads reddish brown until we installed an inline whole house sediment filter. I would change the filter every 3 months. It would be dark reddish brown like an old rusted car.
The current house has a radon problem. We installed a bubbler. It is about the size of a washing machine. All the water goes through it. I typically only drink the water that goes through the fridge filter.