Although wells aren't a very common feature on private properties nowadays, people who do have them have a very important responsibility when it comes to their wells and water testing. This is because there are many different contaminants that can affect the water which will result in consequences for the people drinking from the well and the local community.
Some of the possible contaminants that can affect well water are improperly used fertilisers, animal manures, herbicides, insecticides and pesticides, leaking septic systems, leaking underground storage tanks and pipes, storm drains that send chemicals into groundwater, chemical spills, bacteria and many more things. With a list of possible contaminants almost endless, it is without a doubt that water testing is very important when you have a well.
An example of how important water testing is that sometimes animals die in reservoirs that feed public water systems. Filtration systems and chlorine keep the water clean, and water systems are tested on a regular basis to make sure that customers are getting clean and safe water. Well owners don't have this luxury so they must do their own water testing to ensure that their supplies aren't affected. You can get many portable water testing kits now so that you can do the testing yourself which makes testing so much easier.
If a well is sealed properly, there's no reason why it can't be an excellent water source. As long as anything that could contaminate a well is outside of a 100 - foot radius of the well head, people shouldn't have a problem. Most deep well water sources produce good quality water. Therefore, as long as you are doing regular water testing to ensure that the water is not contaminated, wells can be a perfectly good source of water.
Most problems with well water are not water problems - they are well problems. One of these problems can be because a well is too shallow. They tend to produce low quality water and the quality can change quickly. This means that contaminants can enter quickly as conditions change. For this reason if you have a shallow well it is extremely important to conduct regular water testing.
Other than water testing there is a lot you can do to ensure that your well water is of a good and safe quality. The first step is to identify any possible contamination sources around the well such as underground tanks and bacteria. There are also experts who can tell you how to protect a well and make sure it's safe.