Things You'll Need
Pick a location in your yard for the well. The well must sit a minimum of 50 feet from any cesspools or septic fields. The location should also sit flat or slightly above the surrounding ground, to reduce the chances of the well flooding.
Dig two pits near the location of the well, making each pit at least 2 feet in diameter and at least 3 feet deep. Fill the holes with water and let sit. Set up the rotary drill over the well location and connect the mud pump to the mud pits.
Turn the drill on and it should move through the first five feet of soil without any problems. Once the drill stops moving, thread another drill rod onto the drill and drill another five feet. Keep drilling until the drill seizes or stops, indicating that it hit rock.
Pull the drill from the well and unscrew the blade bit at the end. Set the roller cone drill bit onto the end and tighten it onto the drill. The bit has textured pieces at the end that provide enough resistance to chew through the rock.
Carefully slide the drill back into the well hole. Turn the drill back on and let it dig through the rock. If the rock covers more than five feet, you must add another drill rod to the end of the drill. Once the drill passes through the rock, remove and replace the bit. When the drill starts moving faster, you have reached a softer soil area.