Survival of Coliform Microorganisms in Sediments from a Treated Water Reservoir

Yoon, Heesong; Devinny, Joseph S.; ,

Survival of Coliform Microorganisms in Sediments from a Treated Water Reservoir

by Heesong Yoon,
Joseph S. Devinny,

Document Type: Proceeding Paper

Part of: North American Water and Environment Congress & Destructive Water

Abstract:

Experiments were performed seeking the source of coliform contamination in a treated drinking water reservoir operated by the Los Angeles Department of Water and Power. In recent years coliform counts above drinking water standards were encountered. The possibility of sediment serving as a favorable environment for the growth of coliform organisms was strongly suspected. Sediment had not been removed from the reservoir for over 40 years, and appeared to provide an environment rich in organic matter in contact with the water column. A long term incubation of isolated sediment samples was performed to determine whether the sediments were an effective growth medium for coliforms. Coliforms were sometimes found in the sediments, but in samples isolated in the laboratory, the population died off over a period of about one month. In contrast to appearances, respiration rates and organic matter contents in the sediments were low. The results suggest that the sediments are not a significant source of coliforms in the reservoir.

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