We should correctly define ...
Published by Tom Eckhoff, Principal at Arrigetch Environmental Consulting LLC
We should correctly define the problem. Scale does not "cause the formation of Legionella bacteria." Legionella bacteria are common in natural water courses and widespread in the environment they may contaminate and grow in other water systems such as cooling towers and hot and cold water services. Scale will provide a surface where biofilms can develop and make it difficult for chemical oxidizing products to penetrate the biofilm for effective microbiological control. The EU, and finally the US, have addressed this concern through legislation requiring effective water management programs to minimze the risk of Legionella outbreaks. Here are some good references for a total water management assessment: