In what units are coliform densities reported for the membrane filtration procedure?

Coliform densities in the membrane filtration procedure are reported in Colony Forming Units per 100 milliliters (CFU/100ml). This standard unit of measurement is widely used to present the concentration of bacteria in water samples, allowing for consistency and comparability across different water quality analyses.

Reporting coliform densities in CFU/100ml is practical as it aligns with regulatory standards and guidelines established by organizations, such as the U.S. Environmental Protection Agency (EPA). It reflects the number of bacterial colonies that can form from a given volume of sampled water, giving a clear indication of potential contamination and health risks associated with water quality. This unit also helps in monitoring the effectiveness of water treatment processes and assessing compliance with water safety standards.