Can the avian influenza contaminate water sources?
Category: Food, Water, & Air Safety Questions
Answer:
While there are no documented human cases of avian influenza caused by exposure to highly pathogenic H5N1 avian influenza-contaminated water, it is important to be aware of the potential for such exposure. However, recent joint research conducted by the U.S. Department of Agriculture and the Environmental Protection Agency has demonstrated that free chlorine levels typically used in drinking water treatment are adequate to inactivate highly pathogenic H5N1 avian influenza viruses even at low temperatures such as 5 Centigrade.
Most public water systems using surface water additionally use filtration which is also effective in removing viruses from drinking water making it safe to drink. Some water utilities across the country disinfect but do not filter. These systems are monitored daily for effective levels of disinfectants within the treatment plant and throughout the distribution lines carrying water to homes and businesses. In general, if any surface water source becomes contaminated with an avian influenza virus, it is expected that adequately treated and maintained public water systems will remove and/or kill an avian influenza virus such that the drinking water delivered to customers will be safe to drink.
Water utilities also utilize groundwater that has not been disinfected as a source for drinking water. While some states require that all ground water-based public systems use disinfection as a treatment, this is not always the case. In addition, the vast majority of private wells which many rely on for their source of drinking water do not use disinfection. Some experts think it would be very hard for an avian influenza virus to contaminate most groundwater sources that have not been disinfected. Virus particles become diluted due to the large volume of groundwater they mix with, become inactivated with time, and are removed from groundwater flow during passage through subsurface groundwater systems.
In those cases where there is concern that any public or private well may have become contaminated, water suppliers and the public should contact their local and state drinking water and health experts to determine if precautions should be taken before the well water is used for drinking water.
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Last Updated: 05/22/2007
