The great majority of families in the rural United States, and many other families, besides, depend on water coming directly from the ground for their everyday living needs. The groundwater also furnishes an emergency supply of clean water all over the country, in the event of contamination of the public water supply by, for example, a catastrophic accident or terrorist attack. So all of us should care about keeping the groundwater clean and safe for human use.
Perhaps the greatest threat to the purity of our groundwater is industrial pollution–for example, factories that dump degreasing chemicals, solvents, plasticizers or volatile organic compounds; gas stations whose underground tanks leak petroleum; landfills whose unlined bottoms provide no barrier against the migration of toxic chemicals directly into the groundwater; and farming operations that saturate the ground with pesticides and herbicides that gradually sink into the groundwater.
The US Geological Survey (USGS) has compiled a list of the chemicals most frequently found to be contaminating the groundwater; the typical sources of those chemicals; and the threats to human health that they present. If your family depends upon the groundwater, please take a good look at this list. https://water.usgs.gov/edu/groundwater-contaminants.html
Note that many of these harmful chemicals are colorless and odorless; they can be in your family’s groundwater supply without your realizing it.
If you have any concern that your groundwater may be contaminated, please contact your local health agency, or your state’s environmental protection agency, to find out the best and most reliable ways to test your water, to see if your concerns are justified.