Conventional methods for monitoring heterotrophic plate count (HPC) requireseveral days of incubation. The time to result does not allow for timely information to take corrective actions on substandard quality water. This paper describes thedevelopment work on a system which provides rapid assessments of HPC levels exceeding quality standards as a tool for plant operations. The Colifast Analyser (CA) combines an automated laboratory instrument and a growth medium containing substrates which are cleaved into fluorogenic products by specific enzyme reactions. The media was tested and evaluated by the City of Trondheim VIVA in Trondheim, Norway and the City of Denver, Denver, Colorado. Includes 9 references, tables, figures.