AWWA ACE93145

Distribution system water quality must be monitored to comply with regulations (Total Coliform Rule, Surface Water Treatment Rule) and water quality problems (taste and odor, disinfection byproducts, corrosivity, etc.) This paper describes the monitoring scheme for the Metropolitan Water District of Southern California. Number of sampling locations, parameters tested, and schedule of testing are stated. Also measured are: Assimilable organic carbon, an indicator of biological regrowth; pathogens such as Cryptosporidium and Legionella. Metropolitan plans to install a system of online remote monitoring stations throughout its distribution system. These stations will transmit real-time data on water quality to one or two central locations. Because of the range of new regulations, distribution system water quality monitoring is increasing in both frequency and complexity. This trend can be expected to continue in the future, increasing the cost of water and of staff training requirements. Also important is an increasing emphasis on customer service and satisfaction with drinking water quality.