Well water is water drawn up from the ground.
Wells are dug, driven or drilled into the ground to tap into an aquifer.
Water drawn up from the ground provides about 20% of the fresh water used in the United States. There are over 15 million private wells in America, supplying water for around 40 million people (2005 figures.)
Wells used to be dug out, with shovels. The inside walls might be lined with brick or stone or concrete. Water would accumulate at the bottom, and be brought up as needed with a hand pump. Dug wells will be quite wide compared to other forms of wells.
Driven wells are made with a pipe with a well point at the end driven into the ground. They generally can go down to about 50 feet (15 metres.)
Drilled wells have a hole 4 to 8 inches (10 to 20 cm) wide drilled straight down into the ground. Drilling is a superior technique for wells that have to go far down to hit water. Drilled wells can go down to about 1000 feet (300 metres.) The upper part of the hole that is drilled is lined with a steel casing to help protect the water from surface contamination.
When making a well, you never know for sure how far down you will have to go to get water, and in particular, safe water, especially if they are near areas where livestock is kept, or if flooding has recently occurred in the area, or if there has been construction nearby.
In America, municipal wells serving large populations are usually tested twice a day. As the owner of a private well, it’s up to you to protect and check the quality of the water. Health authorities are now emphasising testing wells frequently. Some states, such as Minnesota, have enacted regulations governing almost every aspect of well construction.
When you contact a lab to get the water from your private well tested, they’ll send you bottles to take water samples in, and instructions, then you send the filled sample bottles back to them, and they’ll send you the results back. They’ll usually give you some guidance on how to interpret the results, but if you want, you can still contact your health department for further interpretation help. Labs will test for things such as Coliform, E. coli, Nitrate, pH, chemical contamination, arsenic, etc. If there’s a problem with the water, you can contact professionals to help you solve it.
Well water can even be contaminated by dead and decaying insects such as earwigs.
Unused wells should be sealed up, to help prevent contamination from entering the ground-water through them.