I would like to learn more. Why is a well cleaner or higher quality than a big city municipal water supply? Is it because city water requires harsher treatment because it comes from a huge pool of waste while a well comes from a clean watershed?

Untreated borehole water is often unsafe to for humans to drink, at least that's usually the case here in Australia.

As for cities, it depends entirely on the specific city.

The city I grew up in was supplied by a river that was unsafe to even swim in due to agricultural runoff and high levels of heavy metals from volcanic activity. Our drinking water was so heavily chlorinated that you practically needed a water filter to make it drinkable.

The city I went to university was supplied by an aquifer and modern, high quality piping. The water was such high quality, it required no treatment at all.

It’s not. There are a ton of variables that determine the quality of your water. In many cases, well water will be significantly worse (my childhood home being a great example).

I'm sure there are different geographical and utility costs, but every well I've ever priced was between 25-100 years to break-even .

How long to break even after building your own search engine?