What is the MCL and MCLG for fecal coliform (FC) / E.coli (EC)?

The Maximum Contaminant Level Goal (MCLG) for fecal coliform and E. coli is set at zero because these organisms are indicators of fecal contamination and potential pathogens in drinking water. Their presence indicates that there is a risk of harmful microorganisms being present, which can pose significant health risks, particularly to vulnerable populations such as young children, the elderly, and individuals with weakened immune systems.

The reasoning behind setting the MCLG for fecal coliform/E. coli at zero is rooted in public health standards; any level of these bacteria in drinking water is deemed unacceptable. This reflects the intent of water quality regulations to ensure that drinking water is safe and that public health is protected from waterborne diseases. The characterization of fecal coliform and E. coli as indicators of contamination drives this zero tolerance approach, emphasizing the importance of maintaining high-quality water standards.

By maintaining an MCLG of zero, regulatory agencies enforce strict monitoring and control measures for water systems to ensure that contamination is prevented, thereby protecting public health from potentially serious risks.