AWWA DSS71295

This paper describes how several utilities used models to find ways of reducing water age in their distribution systems. One utility significantly reduced the water age in its elevated tanks by changing the method of controlling variable speed pumps at a water plant. The model helped optimize the pump controls to have the greatest impact on water age. Modeling for the same utility showed how control valves could be used to reduce water age in a ground storage tank. The valves enabled the utility to direct flows when pumping and filling to reduce water age dramatically. Modeling for another utility showed that water age could be reduced by maintaining lower water levels in a large elevated tank, reducing the volume of storage in a small service area.