AWWA CSC91085

Westpac Utilities, Reno, Nevada, recently upgraded controls on eight filters. This paper describes the new control system and process of implementation in detail. Westpac had a very limited budget and had to keep the plant in operation during construction. For these reasons, Westpac acted as purchaser and prime contractor on the job. The author provides background on existing filter flow controls, backwash controls, and performance monitoring. The design approach and constraints are detailed. Also discussed in some detail are the filter backwash process, including initiation and sequencing. Low-lift pump controls, new sensors, the computer system, training, and construction are briefly discussed. Several start-up problems occurred, resulting from confusion between design directives and desires of the operating staff, lack of training, lack of participation by technicians in the start-up phase, geographic distance between various people working on the project, and commercial software that contained bugs.