Coliform bacteria are a common contaminant in water wells across the country, and are classified under primary drinking water standards as established by the Environmental Protection Agency (EPA).  Coliform bacteria is a term to describe a large group of numerous types of bacteria, and is used as an indicator of potential disease causing bacteria or contamination to a water source.  According to Bryan Swistock, Senior Extension Associate; Water Resources Coordinator at Penn State University, a 2006 survey of 450 private wells found coliform bacteria in approximately 35 percent and E. coli bacteria in about 15 percent of private wells in Pennsylvania.

Testing for specific water born bacteria can be expensive.  Therefore, drinking water standards use total coliform bacteria as an indicator of contamination.  Total coliform bacteria can be easily tested by an EPA certified laboratory.  Testing results for total coliform are often displayed as absent or a colonies per 100 ml count.  Fecal coliform and Escherichia Coli (E. Coli) bacteria are other sub-groups of total coliform bacteria that typically result from the presence of human or animal waste.  Not all coliform bacteria cause harm, but the larger the test result, the more likely that serious disease/illness causing bacteria are present.  Any test result other than "absent" for a water sample warrants immediate treatment action.

If you are worried about the presence of Total Coliform Bacteria in your well, you can purchase our Easy-To-Use and affordable Enviro Test Kit.  It's an easy three step process:


Click here for more information on our Enviro Test Kits.

If a water sample tests positive for total coliform, the first course of action is to have your well inspected by a professional or licensed well driller.  The presence of total coliform bacteria in your water well is most likely due to surface contamination from runoff or agricultural operations, or a leaking underground septic system. Shock chlorination or other disinfection controls can be used to treat your well.  It is advisable to not use water for consumption until your water well has been inspected, disinfected, and retested for total coliform. We have a number of treatment options available. The more common treatment options include chlorination and UV Light for disinfection.

For more information on bacteria and total coliform concerns in your water well, check out the links below.

Maintaining Private Water Systems
Coliform Bacteria

All private well owners should have their water tested annually by an EPA Certified Laboratory. Below is a list of Accredited Laboratories in Pennsylvania.

PA DEP Accredited Laboratories