AWWA WQTC58929

The increased demand for water in the front range of Colorado, coupled with variations in source water quality, has prompted the City of Thornton, Colorado, to expand the existing Columbine Water Treatment Plant from a 28- MGD conventional treatment plant to a 45-MGD microfiltration (MF) and reverse osmosis. To determine which microfiltration membrane system is best suited to treat this source water, several membrane manufacturers were solicited to participate in a pilot study. Characterization of the filtrate water was performed from a turbidity and particle counting perspective and the integrity of each of the pilot systems was tested with direct and indirect test methods. The purpose of this study was to determine the detection limit for a membrane integrity failure on each pilot membrane system using both direct and indirect integrity test methods. In addition, the different issues associated with proper sampling and interference removal for each system were addressed. This provided the opportunity to apply both existing and new indirect monitoring technologies including particle counting, laser turbidity, and multiplexed light scattering. Includes 8 references, tables, figures.