Cryptosporidium parvum and Giardia lamblia are tiny, single celled protozoa that can cause diarrheal illness in humans as well as other species of animals. Other symptoms of human cryptosporidiosis and giardiasis include abdominal pain, nausea, vomiting, fever and flu-like symptoms. It is most threatening in children, elderly and immuno-suppressed or compromised individuals. Infection usually lasts 3 to 12 days, with complete recovery. No effective antibiotic therapy is available for the treatment of cryptosporidiosis, however, there are some antibiotic treatments available for giardiasis. Confirmation of the disease is usually determined though a stool culture.
Waterborne outbreaks of Cryptosporidium and Giardia occur when these organisms are not removed from the water during the normal treatment process. This usually happens in treatment plants that do not practice filtration, or where the filtration process has broken down. Cryptosporidium is also highly resistant to chlorine, which is used as a disinfectant.
Since 1987, Providence Water has been monitoring for Giardia lamblia. Since 1989, Providence Water has been monitoring for Cryptosporidium parvum as well. We are pleased to report that neither organism has been found in our source or finished waters.
The Environmental Protection Agency (EPA) recommends a multi-barrier approach to guard against protozoan outbreaks. This means that water utilities must use various methods to ensure that the water does not become contaminated with the organism. At Providence Water, our first approach is an extensive Watershed monitoring program to identify potential sites of contamination. Our next approach at Providence Water utilizes conventional water treatment, which includes aeration, sedimentation/coagulation, filtration and disinfection. If the source water were to become contaminated with the organisms, the treatment processes would likely remove the organisms, either through sedimentation or filtration. Because we have not found Cryptosporidium or Giardia to be present in our source water, and coupled with the fact that we practice sedimentation, filtration and chlorination, our risk for an outbreak is low.