AWWA PATH50785

The Milwaukee River Watershed is potentially influenced by agricultural, residential, and industrial pollution. The rivers of the Milwaukee River Watershed may influence the water supply for the Milwaukee area, and are also used for several recreational purposes. Watershed and Jones Island WasteWater Treatment Plant sites were tested at least monthly from February to December, as well as after a predetermined level of rainfall, for Cryptosporidium and Giardia. Certain adjunct data was collected to help characterize the condition of the watershed and to analyze the occurrence and distribution of Cryptosporidium and Giardia in the watershed, which included: wastewater treatment plant samples, effluent from storm and combined sewers, other watershed samples, and raw and finished water from the water purification plants. Cryptosporidium and Giardia were collected on spun polypropylene yarn cartridges, or where noted, in 1-Liter grab samples. Bacterial and viral analysis was performed on 100-ml and 1-Liter samples, respectively. The baseline range of Cryptosporidium levels was <0.1 to 7.7 oocysts/L in watershed samples and <0.2 to 8.3 oocysts/L in wastewater effluent. Giardia was detected at concentrations of <1.0 to 179.2 cysts/L in watershed samples and <1.0 to 179.2 cysts/L in wastewater effluent samples. The collection and detection methods used in 1994-1998 allowed an estimated recovery of between 6.1 to 42.8% of Cryptosporidium present and 24.7 to 51.6 percent of Giardia present. Method 1622, used in 1999, has been shown to be more sensitive for Cryptosporidium. Analysis of land use resulted in the documentation of several potential sources and mechanisms of pollution to the watershed. Includes 19 references, tables.