A study of two U.S. Army installation drinking water sources and treatment systems for the removal of Giardia and Cryptosporidium

This paper provides the results of a study of two U.S. Army installation drinking water sources and treatment systems for the removal of Giardia and Cryptosporidium. Sampling was conducted monthly for one year commencing in late March 1994 and concluding at the end of February 1995. Results of this detailed study include examination of turbidity, particle counts, and total and fecal coliforms as well as the enumeration of Giardia cysts and Cryptosporidium oocysts. Our goal, in addition to determining the levels of these pathogens in both raw and product waters, was to determine if typical operating parameters would be helpful in identifying either elevated raw water protozoa or breakthrough of either pathogen in the product water from the treatment facilities. A data summary for the results of the protozoa enumeration is a Table 1. Our results indicate frequent contamination of the raw waters at both sites by either or both pathogens. Further, we observed sporadic breakthrough of low levels of Cryptosporidium in the filtered waters of both sites. The method employed to concentrate, purify and enumerate the pathogenic protozoa is also discussed and comparisons are made to the proposed Information Collection Rule (ICR) method for detection of these microorganisms.