This year there have been many high-profile flooding events in North America, Europe and South Asia. Alongside the terrible loss of human life and property, it is essential that the clean-up begins soon after the event to prevent further loss of life due to water-borne disease.
According to a recent article by the Water Quality and Health Council (WQ&HC), it should be assumed that all flood waters are contaminated with such diseases. As such, once the flood waters have been removed and the affected areas are dry and clear of surface dirt/ debris, a disinfecting solution of water and chlorine bleach should be used. Wearing gloves and protective equipment should also help protect people from flood water splashes and subsequent disease whilst cleaning.
The WQ&HC recommend that the bleach solutions should contain 3/4 cup (~150 ml) regular strength chlorine bleach or 1/2 (~120ml) cup concentrated bleach to one US gallon (around 3.8 l of water) to disinfect walls, floors and other surfaces. Leaving such surfaces wet for at least 10 minutes will help correct disinfection. Also replacing the bleach solution as it becomes cloudy will help reduce the chance of microbial contamination.