It seems to me that most people who rely on onsite wells for drinking water are not testing the water on a regular basis. And that is a big mistake that I do not want you to make. True, testing costs money. But, getting sick because you did not test is crazy. And even if you do not care about your own health, how about your kids?
Wells get their water from underground streams, which are called aquifers. The streams begin at one place and flow underneath your property, and many other properties. While they are flowing, they can pick up contamination from a variety of sources.
They can pick up naturally existing contamination. For example, radon comes from naturally existing rock formations. As the streams pass by or near these formations, they pick up and carry the radon.
Heavy metals, such as lead and mercury, may naturally exist and be absorbed into the aquifer.
Aquifers also pick up contamination from man made sources. A frequently encountered example of this is gasoline from the leaking underground tanks of nearby gas stations. I am sure that many of you have seen closed gas stations with lots of soil in their parking lots. Often, this means that once-leaking tanks are being removed. People with wells that are down hill from these tanks may have consumed the gasoline in their drinking water. Even some uphill residents can be affected.
Factories and industry also add to drinking water contamination. Years can pass from the time such contamination begins until when it is detected. So a lot of dirty water may be consumed before anyone knows there is a problem.
Also, there are landfills scattered throughout the U.S. that have not been properly closed. When it rains, the water can run through these landfills and transmit contaminants from within the landfill into the drinking water.. This process is called "leaching." The mix of water and contaminants is called "leachate."
You might think that you would smell or taste bad stuff in your drinking water before it could hurt you. That is not always correct. Many toxic substances cannot be detected by smell or taste until they reach concentrations much higher than believed to be safe.
Which means: you must test. Test at least once a year, but the more the better. If you cannot afford to test often, you and your neighbors should share the responsibility, so that each year one of you tests. If you all live nearby, with similarly constructed wells, the chance are if something is in one well, it is affecting all of your wells, This is not a perfect solution, but it is better than nothing.
A certified lab should test the samples. Not every lab is certified. Check your state regulators.
What will you test for? Ask both your local and state health officals. The lab may be able to help, but remember, the more the lab tests for, the more money the lab makes.
Yes, you can save money by not testing. But doing so is a bad idea.