"An estimated 34 million Americans get their water from private ground water wells, which are not subject to EPA regulations. Private ground water wells can provide safe, clean water. However, contamination that can cause sickness also can occur in well water.
If you have a well, you should take steps to protect it and have the water tested annually to make sure your water is safe." - Centers for Disease Control (CDC)
Click on Well Water Test Kit link on the left for more information.