Although the wall of the wells can separate the water found in the ground, there are groundwater contaminants that cannot be removed simply and requires additional filtration to make the water safe for drinking. Some of the common groundwater contaminants are: Arsenic Coliform bacteria Fluoride Lead Microbial Contaminants Nitrate Radion Radionuclides Synthetic Organic Contaminants Volatile Organic Compounds (i.e., chloroform, perchloroethylene (PCE), and methyl tert-butyl ether (MTBE)) Fortunately, now you can test your water contamination. This way, you can ensure your well water will not make your family sick.