Wells are nothing more than a hole in the ground with a long series of pipes. The pipe is solid, with the bottom three feet of the pipe perforated, allowing water to enter the pipe. A pump usually sits at the bottom of the pipe and pumps water up to the house.
Depending on where wells are drilled, they may have one of two main problems. The first problem is that they may be subject to contamination. There may be something in the soil or area around the well that gets into the well water causing it to become contaminated with bacteria. This situation is sometimes resolved by dumping chlorine down the well, which kills the bacteria. This, however, may only be a temporary fix, depending on the source of the contamination.
The second main problem with wells is that they may not produce enough water. The bottom of the pipe may be in an area which doesn’t have a large water supply. If a well is not producing enough water, or is permanently contaminated, a new well will need to be drilled. New wells today are often over 200 feet deep and may cost between $5,000 and $10,000.