The basic concept of an underground well used to involve digging a hole straight down and drawing up shovels full of loosened dirt using a bucket and a rope. When the digger finally reached the underground aquifer, and the base of the well was filled, buckets of water could be drawn from the surface with only a little patience and effort. Another common type of well was one that was dug in such a way that people could descend down the hole via a spiraling stair into a chamber where the water could be accessed.
The Evolution of Wells
Modern wells have evolved quite significantly since those early days. Now, sophisticated drill rigs are used to bore holes straight down into the earth, often through solid rock or other obstructions, and water pumps are used to draw water from the underground aquifers and into a house or water supply tank. Equally sophisticated installation methods help to prevent any kind of contamination from spoiling the natural water supply below.
How Well Drilling Rigs Operate
A typical water well drilling rig is brought to the desired site by large trucks or tractor trailers from which the rig assembly itself is set in place for drilling. Some drilling rigs use long cable bits to bore into the earth, while others use interlocking steel bits for the job. In both cases, the drill bit is simply turned in a clockwise direction, and the loosened soil and rock is transported to the surface as the bit turns.
Some drilling rigs also install steel or PVC piping around the bore as the hole is drilled in order to reinforce the hole and to help prevent unwanted contaminants from seeping into the water supply below. Another option is to install the piping separately, once the drilling process is completed.
As the drill bit turns in the earth, it often becomes heated and requires the use of water or mud for cooling and lubrication. In some cases, a premixed mud solution can be used of which the consistency can be purposefully altered throughout the process in order to provide the most useful consistency for the types of soil and rock being drilled through.
Water Filtering and Pressurization
Once a well has been installed with a drilling rig, filters are typically installed in the base of the well in order to prevent larger particles from being drawn into the water pump and also to ensure the water is loosely filtered. This is done through the use of screens and gravel that are placed in the well bottom before the water pump is installed.
In order to reduce the amount of electricity needed to pump water from the well, many well owners also install secondary water tanks, attaching smaller pumps to them, for specific use in houses and outbuildings. In this way, enough water is drawn to fill the tank, and then the smaller pump, sometimes with the assistance of gravity, provides the water pressure needed to pressurize plumbing systems.