What unit is commonly used to quantify fecal coliform results?

The commonly used unit to quantify fecal coliform results is the Most Probable Number (MPN). This method estimates the concentration of fecal coliform bacteria in a water sample based on statistical likelihood, using a number of test tubes or wells to determine the presence of these bacteria. MPN is particularly valuable in microbiological testing because it provides an estimate that reflects the uncertainty inherent in detecting bacteria, particularly in diluted or varied samples.

Using MPN allows for effective monitoring and regulation of potentially harmful bacteria present in water sources, which is crucial for public health and environmental safety. Given the nature of fecal coliform, which indicates contamination by fecal matter, accurate quantification is essential for assessing water quality and ensuring compliance with health standards.