Biochemist here. I made injectable-grade solutions. Tap water couldn't get anywhere near the labs because it was so contaminated with crap. Lots of filters, of several kinds were employed, then distillers. The end product is what we would use in the labs, drink, use in the coffee pots and tea kettles, even bottle up to take home, because we saw what came out of the city water.
Biochemist here. I made injectable-grade solutions. Tap water couldn't get anywhere near the labs because it was so contaminated with crap. Lots of filters, of several kinds were employed, then distillers. The end product is what we would use in the labs, drink, use in the coffee pots and tea kettles, even bottle up to take home, because we saw what came out of the city water.