Page 45 - CBT 2018

Microbiology of water mains
Treated water can spend hours to weeks in water mains and associated infrastructure, during which time significant changes can occur to
the quality of the drinking water. To combat the risk of pathogens, public water supplies in the US typically maintain a nominal concentration of residual chlorine (free or combined)
as a disinfectant. The use of residual chlorine, however, comes with a price in the form of unpleasant taste and
the formation of potentially harmful byproducts. CEGE researchers learned that systems with a high residual monochloramine concentration harbor biofilm communities that are dominated by Mycobacteria spp., bacteria known for their resistance to disinfectants. In contrast, without residual disinfectant bacterial quantities tend to be significantly higher in both the water main biofilms and tap water and the communities are more diverse. This work has important implications for protecting public health and preserving water supply infrastructure. [81]
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