Just some food for thought:
As the clerk of my town, I worked with our water operator within my local municipality. For starters water quality is GROSSLY all over the map wherever you go. We have extremely heavy manganese in our water supply, it's naturally in our water source and pumps out as we pump. Our average PPM's in our tap water from the faucet's about 800+. That's INSANELY HIGH for drinking water. There are times the concentration is so thick, it looks like literal CO
EE coming out of the faucet. We purposely have to flush fire hydrants all through the town just to try to drain the lines of the buildup, because the town is too broke to afford proper filtration before it hits our distribution lines. Drive about 10 minutes over to the next town, no manganese. Instead, they have heavy concentrations of uranium in their water (this is Colorado folks, those "tap the Rockies" commercials are BULLSHIT lol!)
The ONLY thing we treat our water with before it goes to the tap is chlorine, and it's 100% dependent on the person checking it every single day to make sure the levels are correct both at the pump house (in our case, 2 miles of pipe between us and the pump house,) making sure the injector is working properly, making sure the concentration is correct at the tank itself (chlorine dies very rapidly as it travels!) not to mention taking samples throughout the month from various residence and businesses to check concentration at the actual tap.
In 6 months, I've seen the town's water supply get distributed with NO CHLORINE in it period. Unfiltered, untreated water being sent to the tap to feed to babies, animals, elderly, and anything in between.
In that same 6 months, I've seen the town's water supply get distributed with DOUBLE THE LEGAL LIMIT of chlorine concentration, and the solution was "well, it'll die off anyway eventually."
I've found out it's RIDICULOUSLY easy to cook the books on reports too; the operator was telling me "yeah I can pretty much put down any passing number that I want and as long as it's not too far fetched, no one EVER checks." Pretty terrifying, the accountability with water supplies seems to only factor in AFTER someone gets sick.
So your water quality is quite likely going to bounce around a bit. This is a small town and a small water system; but the quality doesn't necessarily go up just because you scale up in size either.