AWWA ACE93116

Reliability models containing computerized equipment databases and spreadsheets have been developed for five filtration plants operated by the Metropolitan Water District of Southern California (Metropolitan). Model development was based on water quality criteria from the Surface Water Treatment Rule (SWTR) and Metropolitan treatment goals, mechanical equipment data, several operating assumptions and classical reliability equations. After development of equipment configuration and plant block diagrams, equipment, unit process and overall plant mechanical reliabilities were calculated. This paper presents the development of the reliability model, including the data collected, assumptions made, criteria used and calculations performed. The results of the model at each plant and the subsequent evaluation of equipment performance, redundancy and spares is also presented. The use of "what-if" calculations to determine the effects of equipment changes or spare levels is explained through the use of model results at the Metropolitan plants. Finally, the benefits of a reliability model are presented, both for the Metropolitan and for water treatment plants in general.