Using Water-Distribution System Modeling to Assist Epidemiologic Investigations

Abstract

An epidemiologic study of childhood leukemia and central nervous system cancers that occurred in the period 1979 through 1996 in Dover Township, N.J., is being conducted. Because groundwater contamination has been documented historically in public- and private-supply wells, there is the possibility of exposure through this pathway. The Dover Township area has been primarily served by a public water supply that relies solely on groundwater; therefore, a protocol has been developed for using a water-distribution model such as EPANET as a tool to assist the exposure assessment component of epidemiologic investigation. The model is being used to investigate the question of human exposure to groundwater contaminants. Because of the unavailability of historical data, the model was calibrated to the present-day (1998) water-distribution system characteristics. Pressure data were gathered simultaneously at 25 hydrants throughout the distribution system using continuous recording pressure data loggers during 48 h tests in March and August 1998. Data for storage tank water levels, system demand, and pump and well status (on/off) were also obtained. Field data gathering procedures, calibration results, and water-quality simulation using a naturally occurring element (barium), as well as an analysis indicating the percent of water originating from points of entry to the water-distribution system for 1998 conditions, are presented.