A drilling team drills deep into the earth to reach fresh aquifers. Drilled wells typically are used in areas of geologically poor soil conditions. Drilled wells are commonly drilled by one of two methods: The first is known as “cable tool” or “percussion” method. It involves a machine that alternately lifts and drops a long chisel -shaped bit within the bore hole . The hole is deepened as the bit cuts and breaks the rock. A bailer is used to extract the cuttings as necessary. The second is called the “rotary well drilling” method. A rotating bit is fixed to the end or the drill pipe. The rotary action of this bit chews into the rock or other earth materials. Air or water is used to transport the cuttings to the surface. Water seeps into the bore hole through cracks or seams in the rock, and is extracted from the bore hole by means of a submersible pump typically installed to a depth greater than that of the water bearing seam.
