Disinfection resistance of waterborne pathogens on the United States Environmental Protection Agency's Contaminant Candidate List (CCL)

In 1999, the United States Environmental Protection Agency developed a list of emerging waterborne microbial pathogens that may pose a risk in drinking water. This review deals with the disinfection resistance of microorganisms on the Contaminate Candidate List or CCL. Current disinfection practices in the United States appear to be capable of dealing with most of the microorganisms on the CCL, with the exception of Mycobacterium avium and adenoviruses. Mycobacterium avium is more resistant to most disinfectants than other waterborne bacteria and adenoviruses are the most resistant waterborne microorganisms to inactivation by ultraviolet disinfection. The microsporidium, Encephalitozoon intestinalis, shows significant resistance to inactivation by chemical disinfectants and further research on additional species of microsporidia appears to be warranted.