The most significant sources of waterborne disease outbreaks in the U.S. are now distribution and plumbing deficiencies, with legionellosis, caused by Legionella, being the greatest number of reported outbreaks and having the potential to cause fatality in those infected.

Although public water systems have made major enhancements in installations and operations of treatment technologies and water quality monitoring, causing significant reduction of traditional waterborne diseases, types of illnesses have changed to water distribution related causes; these sources can’t be entirely eliminated at the central municipal water treatment plant, calling for a different approach in order to protect public health.

Numerous pathogenic regrowth microorganisms, like Legionella, are known to inhabit water distribution and plumbing systems and there is no “go to” method for treating these disease-inflicting pathogens.

“The problem of controlling microorganisms colonizing plumbing and distribution systems is not trivial because many of them are associated with biofilms or protozoa such as amoebas,” wrote Water Technology’s Technical Editor Dr. Joseph Cotruvo. “Thus, even though they may be susceptible to disinfection in suspension, the disinfectants may not have ready access to them in biofilms so that they can be killed.”

Disinfectants, which include chlorine, chloramine, ozone, UV light, copper/silver ionization and shock heat or disinfectant treatments, have their own benefits and weaknesses, sometimes being combined and supported by system monitoring, for success. 

In the May 2014 issue of Water Technology our Technical Editor Dr. Joseph Cotruvo wrote about waterborne diseases in our magazine’s popular section “Professor POU/POE.” You can read more from that article here.