Parasitologists from the College of Veterinary Medicine at Cornell University are determining the natural occurrence of Cryptosporidium and Giardia in domestic animals and wildlife, and the factors determining infection in dairy herds. Microbiologists in the College of Agriculture and Life Sciences, Cornell University, are studying the survival and transport of Cryptosporidium and Giardia in the environment. This research will provide the scientific basis for recommending management practices to reduce infection in dairy herds and reduce risks of contamination to New York City's water supply. Parasite Monitoring Recent outbreaks of Cryptosporidiosis and Giardiasis in filtered water supplies of several cities suggest that waterborne diseases are associated with sudden large infusions of pathogens in the finished water supply. It is therefore essential to determine the potential for any sudden increase of these parasitic protozoa in New York City's water supply.
Routine monitoring is conducted at more than fifty sites on a watershed basis.
Most sites are monitored monthly, with additional monitoring conducted on a daily or weekly basis. More than 1,000 liters of source water from the Kensico and New Croton Reservoirs is pumped through a filter, that is then shipped to a laboratory for analysis. Material trapped in the filter is released, concentrated, treated with antibiotics that attach to Cryptosporidium and Giardia, then treated with a stain which attaches to the antibodies. This material is examined under an epifluorescence microscope for the presence of Cryptosporidium or Giardia. In fact, New York City's source water pathogen levels are not only low, they are consistently low and extremely uniform.