The bit the water companys don't tell you is, in some parts of the UK, bore hole water is mixed six parts to one part reservoir water, to get the chemical pollutants lower than the legal maximum. I have heard that in some places, it gets so bad, that they cannot put res water into the pipes. It's all bore water, or tankered in.
This is expensive, not to mention getting solids out, from chronic soil erosion.
It's also massively destructive to the environment. This is fossil water, that hasn't been moved for millennia, in some places.
Welsh Water, a non profit company, has bashed it heads against the wall for so long, trying to get the various different agencys to screw the Farmers necks in, without success, that it has now sent a letter to farms in the Wye valley, begging Farmers to use chemicals responsibly.
It won't work.
Not only are you paying the water companys to clean the water, your paying the Farmers, to pollute the water, too..........