@Brad E.
I have sold a property like this before. Similar situation where it was a large property split into 3 after the well was established. My buyers had similar concerns to yours. We looked up connecting to city water but would have had to pay for a mainline extension as the water main didn’t reach this particular part of the neighborhood.
When you get your title report, you should be able to look back in the original documents from when it was split up and find where they deeded the right to water from that well to each property. If you can’t find that, think about getting a new written agreement from whoever is on title with the actual well.
This isn’t as uncommon as you’d think but I understand your concern. The other issue to understand is who is responsible for maintenance and when was it last done. Typically each of the properties pays annually for the power and maintenance to the well. Be sure to find out what those fees are and who controls that.