Identifying Watershed Sources of Waterborne Parasites (Cryptosporidium spp. and Giardia spp.)

Abstract

Recent studies in Alberta have shown that agriculture can impact surface water quality with elevated levels of nutrients and bacteria. However, there is limited information available to determine if agriculture in cold climates is a significant source of waterborne pathogens to surface waters. High levels of Cryptosporidium spp. and Giardia spp. in the raw drinking water supply at Edmonton, Alberta in 1997 led to the development of a three-year research project to identify sources of these parasites in a large northern river basin. Sources targeted for investigation include municipal sewage effluent, agriculture and wildlife. The collaborative research project, initiated in 1998, includes water monitoring and parasite prevalence surveys. Water quality monitoring in the North Saskatchewan River Basin is being conducted on the major tributaries between Rocky Mountain House and the City of Edmonton; on sewage effluent and source drinking water supplies in rural communities and on the river in the City of Edmonton. The prevalence of parasites in agricultural operations and wildlife in the basin is also being surveyed. Cryptosporidium spp. and Giardia spp. levels found in the major tributaries in the NSR basin are highly variable and tend to be influenced by the type of watershed (forested versus agricultural), the time of year of runoff and the patterns of runoff. Municipal sewage effluent is a source of Cryptosporidium spp. and Giardia to the NSR with effluent from sewage treatment lagoons having the highest concentrations of both parasites. This unique research initiative brings together various departments of provincial and federal governments, academic institutions, industry and the agricultural community to determine the sources of waterborne parasites in a large river basin. The project will conclude March 3, 2001.

The City of Edmonton River Water Quality Task Force

“…The data was obtained to provide complementary information for a three year project, undertaken by Alberta Agriculture and other partners, investigating sources of Giardia and Cryptosporidium in the NSR basin upstream of Edmonton (S. Cooke et al, 2000). Parasite samples in both projects were enumerated by EPCOR Water Services laboratory.…”