Heavy rains have produced flooding in many areas recently putting private water supplies at risk. Testing the water for the presence of bacterial indicators is a key step in ensuring safe water going forward. What more can well owners do to protect themselves?
During heavy rainfall events and the subsequent flooding, a critical concern is the safety of the water supply. This is particularly important if a home is served by a private well. Flood waters carry bacteria, chemicals, and other contaminants that can be introduced into the well as water rises over the level of the wellhead. That’s why it is vitally important that the well water be tested before consuming it. It is not uncommon to see local environmental or public health agencies offer free testing in communities impacted by flooding to help ensure that as many wells as possible are tested.
What should happen next is dependent on the test results. What could happen next is independent of the results. Here’s why. If the well water tests positive for coliforms or E. coli, common practice (the should) is to disinfect the well and the household plumbing, replace any water filters in use (including the one in the refrigerator), and then to re-test (and if necessary repeat this process) until a favorable result is achieved. This is necessary to be sure. It’s easy to see how this process could stretch over a week or more, and in the meantime, it’s necessary to boil the water before drinking it or to purchase bottled water for all cooking and drinking needs. And that is typically where any treatment stops. What then of ongoing protection or disinfection of the water? In cities and towns around the world, disinfection of drinking water happens day in and day out because continuous disinfection protects public health. Why would a private well owner choose any other standard of protection for their drinking water? Certainly a major flood is an exceptional circumstance, but a changing climate means more intense and more frequent rainfall events and increased risk of surface waters infiltrating and contaminating well waters. Choosing continuous disinfection, like an ultraviolet water system, irrespective of the test result, means being protected at all times (the could).
Data gathered on disease outbreaks from drinking water systems in the USA from 1971-2008 indicate that the majority (67%) are associated with groundwater. Of these, about 20% are due to flooding. An ultraviolet disinfection system provides 24/7 insurance that your drinking water is pathogen-free.