For many of us, the thought of a water well brings back memories of learning about settlers of centuries past. While this old fashioned method for a family to have to fetch their own water from a hole in the ground has long been replaced by water treatment plants and modern plumbing, they are still used around the world as a source for clean drinking water. Presently there is a lot more technology involved in digging, monitoring and the maintenance of different wells. Wells are generally deep holes in the ground that are used to gather water. Whether or not it is for consumption, irrigation or for scientific samples, wells are used all over the world. These samples can be used to ensure that there aren’t any contaminants in the soil or in the groundwater that would affect the wells and those using them.
Types of Wells
There are three main types of wells that are still used around the world. The traditionally dug well is used more in third world countries because it is the most economical method out there. Historically, they have been the type of well we think of when the word comes to mind. Usually about 10 to 20 feet deep, they feed from shallow groundwater and normally produce water that is safe to drink. These dug wells are generally becoming obsolete because of the amount of labor required to dig and maintain the wells. As well, these wells can be quite dangerous and unstable. In more industrial settings drilled wells are used to go deeper into the ground to reach aquifers and underground water sources. Driven wells are simply hammered into the ground until the workers encounter groundwater. When this happens, the well is washed of any and all sediment and a pump is installed to retrieve the water.
Classifications of Different Wells
There are four different types of wells that can be dug. Shallow and confined are wells that are typically dug and do not go very deep into the ground. Inversely, deep or confined wells are dug much deeper and typically draw water from aquifers, these are mechanically drilled wells. Production wells are wells that are drilled deep down whose sole purpose is for water extraction. Finally, monitoring wells are used to monitor the chemical make-up of water at various depths in the ground. It can be easy to confuse the different types of wells as a lot of the characteristics of them overlap.
Contamination of Wells
While well water is normally safe to drink it can become contaminated by various things, both manmade and natural. The most common contaminant is that of bacteria, viruses, parasites and fungi. These types of contaminants can attribute to things like E. coli poisoning, hepatitis A and E, and rotavirus (among others). Probably the most common and preventable contaminations occur from pesticide use in farming and agriculture. The chemicals leach down into the groundwater supply and make their way to well water, sometimes without the knowledge of the people using the water.