City -vs- Well Water
A simple way to know if you are on city water is if you are paying a water bill.
City water issues: Uses chlorine and chloramine to kill bacteria. Many times fluoride is added to to the water. Also, there tend to be higher levels of pharmaceuticals, heavy metals and VOCs.
Well water issues: It can vary but usually has one or all of the following: bacteria and viruses, dissolved solids and sediment, acidic water, fluoride, hydrogen sulfide, iron and manganese.