Abstract
When an intestinal infectious disease is outbroken in a city, the water environment receiving the effluent from the wastewater treatment plant in the city will be polluted by the pathogen without the appropriate treatment. In such cases, there is possibility that the outbreak of waterborne infectious disease occurs in other cities using the water environment as the source of drinking water. In this paper, the propagation model on outbreak of waterborne infectious diseases between two cities in the watershed was developed taking some factors (pathogen removal efficiencies by water and wastewater treatments, the river flow rate, the pathogen concentration in the river, and so on) into account. The outbreak propagation coefficient (OPC) was very available for the watershed management from the viewpoint of public health.
