Association of microorganisms with surfaces in distribution systems

A readily-assimilable source of carbon was added to samples of water collected from a water distribution system characterized by heavy corrosion and loose deposits. Both the indigenous population of bacteria attached to the particles in the water and also added coliform bacteria, accumulated in association with the particles, but this increase was not reflected in plate counts of the water. The implications for bacteriological examination of water supplies are considered. There re 30 references.