AWWA DSS69198

This powerpoint presentation begins by providing a brief overview of the Golden State Water Company, located in Gardena, California, and its corrosion control program. The goals of the program are presented, along with the system's flushing program and the results of the main sampling parameters that include the following: total chlorine residual; heterotrophic plate count; customer complaints; time spent flushing; and, water loss through flushing. Presentation conclusions indicate the following: implementation of corrosion control in Area 5, 6 and 7; immediate effect on disinfectant residual - increase; as expected, initially elevated HPC levels and customer complaints that decreased with time; short-term episodes of low disinfectant residuals, high HPCs and more customer complaints; should be expected shortly after implementation of polyphosphate blend addition; aggressive flushing after implementation of corrosion control was necessary for a couple of months to control and restore water quality to desirable water quality goals; the addition of the polyphosphate blend will soften and remove existing biofilm layers and corrosion products - this is initially a fast but then a very slow process; in comparison to last year, we were able to decrease flushing time in areas under corrosion control; system-wide we were able to reduce water loss through flushing; when implementing corrosion control, reduce and adjust flushing carefully; establish background water quality data and monitor trends closely to avoid water quality degradation during implementation of corrosion control; and, last but not least, communication between departments is absolutely necessary for a successful corrosion control program. Includes tables, figures.