1. Enteric virus infection risk from intrusion of sewage into a drinking water distribution network.
- Author
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Teunis PF, Xu M, Fleming KK, Yang J, Moe CL, and Lechevallier MW
- Subjects
- Drainage, Sanitary, Drinking, Environmental Exposure statistics & numerical data, Humans, Monte Carlo Method, Pressure, Risk Assessment, Risk Factors, Soil Microbiology, Fresh Water virology, Sewage virology, Virus Diseases epidemiology, Water Pollutants analysis, Water Supply analysis
- Abstract
Contaminants from the soil surrounding drinking water distribution systems are thought to not enter the drinking water when sufficient internal pressure is maintained. Pressure transients may cause short intervals of negative pressure, and the soil near drinking water pipes often contains fecal material due to the proximity of sewage lines, so that a pressure event may cause intrusion of pathogens. This paper presents a risk model for predicting intrusion and dilution of viruses and their transport to consumers. Random entry and dilution of virus was simulated by embedding the hydraulic model into a Monte Carlo simulation. Special attention was given to adjusting for the coincidence of virus presence and use of tap water, as independently occurring short-term events within the longer interval that the virus is predicted to travel in any branch of the distribution system. The probability that a consumer drinks water contaminated with virus is small, but when this happens the virus concentration tends to be high and the risk of infection may be considerable. The spatial distribution of infection risk is highly heterogeneous. The presence of a chlorine residual reduces the infection risk.
- Published
- 2010
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