Drilling a new residential well is fairly simple and straight forward.
There are a few state requirements for a new residential well:
1) 50 Feet from property line, unless grouted/cemented from the top of the water production screen to ground level.
2) 100 Feet from any Septic, including drain fields or sprinkler systems.
Public wells require quite a bit of paperwork and planning from the state of texas.
They also require a 3rd party engineer to monitor drilling activity to ensure it is done to state rules.
Irrigation wells also require quite a bit of paperwork, and depending on county and even times of year limit the amount of water you can produce.