Biological Corrosion in Freshwater Environments

Microbial films will affect the general corrosion only when the film is continuous. This is not the case in general and microorganisms form in discrete deposits or colonies and the resulting corrosion is localized. 

A uniform slime film formation on the piping of potable water systems and on the heat-transfer surfaces of low-temperature heat exchangers is inconsequential unless it obstructs the flow leading to a health hazard by growth of the organisms or localized corrosion (41). 

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