It is possible to fill a pool with well water, and in some cases it is the most affordable option. Filling up an average-sized pool with a water hose usually costs about $80-$160 dollars, depending upon the geographical location.
The biggest concerns about filling up with a well is that the well may run dry or the water pump may burn out. Experts recommend starting to fill the pool with a hose and checking back in two hours to see if the water flow has slowed down. If it has, a water truck delivery may be necessary to avoid burning out the well pump.