Drinking Water
“A drinking-water distribution system provides a habitat for microorganisms, which are sustained by organic and inorganic nutrients present on the pipe and in the conveyed water. A primary concern is therefore to prevent contamination from fecal material that might build up near pipes or contaminate surface or soil water.
Generally, bacteria present in the water and on surfaces are harmless, but they are at the base of a food-chain for other free-living organisms such as fungi, protozoa, worms and crustaceans. These organisms may be present in a distribution system, even in the presence of residual disinfectant, and the water can still be free of health risks.
However, excessive microbial activity can lead to deterioration in aesthetic quality (e.g. tastes, odours and discolouration) and can interfere with the methods used to monitor parameters of health significance.
Therefore, additional treatment may be needed to control the quality of the treated water in a distribution system, to prevent excessive microbial growth and any associated occurrence of larger life forms.”
- 2004 World Health Organization. Safe Piped Water: Managing Microbial Water Quality in Piped Distribution Systems. Edited by Richard Ainsworth. ISBN: 1 84339 039 6. Published by IWA Publishing, London, UK. https://apps.who.int/iris/bitstream/handle/10665/42785/924156251X.pdf;sequence=1
- 2022 World Health Organization. Guidelines for drinking-water quality: Fourth edition incorporating the first and second addenda, https://www.who.int/publications/i/item/9789240045064