AWWA JAW34243

Cryptosporidium is rather new to the waterborne disease game. First recognized as a human pathogen in 1976, it has been responsible for a number of outbreaks of waterborne disease, most notably the recent Milwaukee, Wisc., outbreak. Cryptosporidium appears to be widespread in the environment and is difficult to detect. While it is known to cause gastrointestinal distress, the infective dose is not known. Complicating matters is the fact that some outbreaks of waterborne disease attributed to cryptosporidium may in fact be cause by multiple factors, including hard-to-detect viruses. A review of recent outbreaks reveals that often, multiple causes are to blame. Cryptosporidium is difficult to kill; chlorine and chloramines are ineffective. Ozone is the most effective disinfectant, but filtration and watershed protection are the only conventional control practices available for fighting the microorganism. Although the Surface Water Treatment Rule (SWTR) does not regulate Cryptosporidium at present, the pathogen is on the USEPA's Drinking Water Priority List for possible regulation, and then Enhanced SWTR will set a maximum contaminant level goal of zero for Cryptosporidium. This article presents a good overview of information about Cryptosporidium. Includes 27 references, table.