Many millions of households in the United States use wells as their main source of water. Wells extract water from aquifers, which are underground layers of earth, gravel, or porous stone where ground water accumulates.
In its simplest form, a well is simply a hole drilled down into an aquifer. A pipe and pump inserted into the hole are used to draw water out of the ground, and a screen filters out unwanted particles and other material that might clog the pipe. Wells can be a variety of different shapes and sizes, depending upon the type of earth they're cut into and the amount of water that they're designed to pump out.
There are three basic types of wells:
– Bored (also called shallow) wells are generally bored into unconfined water sources, typically found at depths of 100 feet or less.
– Consolidated wells (rock wells) are drilled into subterranean formations of porous rock that contain no soil and do not collapse. Their average depth is normally around 250 feet.
– Unconsolidated (or sand) wells are drilled into below ground formations consisting of soil, sand, gravel or clay material that collapses upon itself.
The proper installation of a functional well is based on establishing its most suitable location, sizing the system correctly and choosing the appropriate construction techniques. Because of these factors, it's advisable that only professional water well contractors should undertake the installation of wells. They're familiar with the hydrology (which is water's properties, distribution and effects above, on and below the earth's surface) of their area as well as the local codes and regulations that must be adhered to – and there are a number of them. When selecting a contractor, look for certification and membership in the National Ground Water Association, a nonprofit trade and professional society that establishes standards for contractor competency. They can provide a listing of all local member contractors.