Han Heijnen, Namrata Pathak, M. Feroze Ahmed
The World Health Organization has published the 3rd edition of the Guidelines for Drinking Water Quality in late 2004. In May 2007 WHO has reviewed an addendum to the Guidelines on rainwater for human consumption. A stand-alone document on collection and storage of rain water for human consumption is also under preparation. While several countries have national guidelines or standards for water quality of collected rain water used as drinking water source, the growing utilization of rainwater as a potential source of water for human consumption makes it imperative that WHO recognizes rainwater and includes appropriate guidance in the Guidelines for its use.