If you have a well, then you probably already know that your water needs to be tested regularly. What you may not know is that the government keeps track of the results of each well test. There are some very specific reasons for this, some which may surprise you.
The government, specifically state and county governments, like to keep track of the number of "healthy wells" in the area. These wells produce the safe, potable water that you drink and use in your home. Your governments want to know this in case there is a water shortage and fresh potable water from wells has to be tapped for various purposes. They also want to be sure that the wells everyone uses are not contaminated by other activities in the area.
Contaminated Wells and Tracing/Tracking the Source of Contamination
Well water testing and the results also helps the EPA, CPA (Consumer Protection Agency), and a few other government agencies find contaminated wells. From there, these agencies trace the contaminants back to the sources, and track how the ground water in the wells is being contaminated. These are public records, so you can request test results any time you think that your well has been contaminated or suspect that industrial or manufacturing activities has something to do with it. The government agencies then bring legal action against companies that are involved with the contamination in order to right what is wrong.
Locating Wells That Are No Longer in Use
When wells go dry, or are bypassed for city sewer systems, they are often sealed off and forgotten. The government tracks these forgotten wells so that if someone disappears, the first place search and rescue teams can look is in these wells. It is very easy for children and smaller adults to vanish down a forgotten well, so having a useful record of these wells is important. It is also useful if you want to know if there is a well on your land that you need to be concerned about and should probably mark or seal off for others' protection.
Shifts in the earth and ground water flow changes over time. The pathways of underground water can be vastly different than they were twenty years ago. That said, it is possible to "reactivate" a well after some time if there are no other fresh well options. It does require some digging and maneuvering of the underground pathways from the largest and nearest body of water to the old well, and then the water has to be tested thoroughly to ensure that this reactivated well is a healthy well.