Water-Distribution System Modeling as a Tool to Enhance Epidemiologic Case-Control Investigations: A Case Study–The Dover Township (Toms River) Childhood Cancer Investigation

The Agency for Toxic Substances and Disease Registry is conducting an exposure assessment for use in an epidemiologic study of childhood leukemia and central nervous system cancers that occurred in the period 1979 through 1996 in Dover Township, New Jersey. Groundwater contamination has been documented historically in public- and private-supply wells. Therefore, there is the possibility of exposure through this pathway. Because the Dover Township area has been primarily served by public water supply that relies solely on groundwater, the EPANET water-distribution model, integrated with spatial analysis technologies, is being used to reconstruct historical water-distribution system characteristics and investigate the question of exposure. To assist in calibrating the model to the current system, pressure data were gathered simultaneously at 25 hydrants using continuous pressure recording data loggers during 56- and 82-hour tests in March and August 1998, respectively. Data for storage tank water-levels, system demand, and pump and well status (on/off) were also obtained. Historical information on the water-distribution system configuration will be used to relate the case and control addresses to the areas historically served by the water-distribution system. Based on system operation data, model simulations will be used to estimate the percent of water delivered to a specific location from each of eight points of entry to the water-distribution system.