Typically, groundwater is naturally clean and safe for consumption. Because the overlying soil acts as a filter, groundwater is usually free of disease-causing microorganisms. However, contamination may occur following improper installation of well casings or caps, after a break in the casing or as a result of contaminated surface water entering the well. Contamination can also occur if wells are drilled in fractured bedrock without an adequate layer of protective soil and with less than the recommended minimum casing length.
In order to prevent illness, wells should be properly maintained and the water regularly tested for the presence of microbial contaminants. Well water should also be tested occasionally for possible inorganic and organic chemical contaminants.
Well Maintenance - Testing Well Water for Microbiological Contamination
Interpreting the Results of Testing
Corrective Action for Water that Does Not Meet the Recommended Guidelines
Water Treatment Devices for Home Use
Back to Main Page - Coliform Bacteria