AWWA JAW30403

This article describes the efforts of water utility personnel to determine whether the level of endemic giardiasis observed in their service area could be attributed to the surface water supply, which is chloraminated but not filtered. Comparison of epidemiological data for the county in which the utility is located with data from another county that used conventionally treated water showed similar incidence rates, partitioning into risk categories, and age distributions for giardiasis. There was no correlation between the location of a giardiasis case and disinfection contact time within the unfiltered water's distribution system. Includes 18 references, tables, figures.