Private water wells provide drinking water to over 1,000,000 Virginians. If you have your own well, then the responsibility for ensuring that your family and friends are drinking safe water rests with you. Just because your water appears clear doesn’t necessarily mean it is safe to drink. It is important to test your well at least once a year for bacteria, nitrates, pH and total dissolved solids. Testing is often the only way to detect possible contaminants in your water. Testing is not mandatory but should be done to ensure your family’s safety. First, make sure that no potential sources of pollution are located near the well, especially uphill and surface water drains away from the well. The best time to do this testing is in the late spring after the snow has melted and there has been a considerable amount of rain. Take your samples on a day after a good rain so that any infiltration problems will be detected. Testing is often the only way to detect possible contaminants in your water. Testing is not mandatory but should be done to ensure your family’s safety.
Coliform bacteria are commonly found in soil, on vegetation, and in surface water. They also live in the intestines of warm-blooded animals and humans. Some coliform bacteria strains can survive in soil and water for long periods of time. Coliform bacteria is not likely to cause illness, but coliform bacteria are most commonly associated with sewage or surface waters, the presence of coliform bacteria in drinking water indicates that other disease-causing organisms (pathogens) may be present in the water system. There are three different groups of coliform bacteria; total coliform, fecal coliform and Escherichia coli (E. coli) each has a different level of risk. Total coliform serves as a proxy for fecal coliform and E. coli bacteria in the most basic water test. Coliform bacteria do not occur naturally in most aquifers. Fractured or creviced bedrock aquifers that are close to the surface are the exception and testing for e. coli and fecal coliform and nitrogen will help differentiate the naturally occurring coliform from contamination that might impact your health.
Bacteria can be introduced into a new well during construction and can remain if the water system is not thoroughly disinfected and flushed. Well construction defects such as insufficient well casing depth, improper sealing of the space between the well casing and the borehole, corroded or cracked well casings, and poor well seals or caps can allow sewage, surface water, or insects to carry coliform bacteria into the well. Unplugged abandoned wells can also carry coliform bacteria into deeper aquifers. In an existing well system that formerly was bacteria free look for defects, deterioration in the condition of the well. These include: openings at the top of the well; old, rusty, or damaged well casing; unprotected suction line; buried wellhead; and, close proximity of a well to septic tanks, drain fields, sewers, kitchen sinks, drains, privies, barnyards, animal feedlots, abandoned wells, and surface water.
A good place to get help and information is from the Virginia Master Well Owner Network (VAMWON) which consists of Virginia Cooperative Extension (VCE) agents and screened volunteers trained in the proper design, management, and maintenance of private water supply systems (springs, wells, and cisterns). The trained VAMWON volunteers reach out to private water system owners in a variety of ways, ranging from speaking at local community groups, HOA meeting to informal discussions with friends and neighbors to inform Virginians dependent on private water systems about water testing, water treatment, and system maintenance. The training of these volunteers is made possible by a grant from USDA Cooperative State Research, Extension and Education Service (CSREES). This grant was made to revitalizing the Virginia Household Water Quality Program (VAHWQP) to help the program improve the water quality of Virginians using private water wells.