Subsurface fate and transport of cryptosporidium in soils of Wisconsin’s carbonate aquifer region

Cryptosporidium parvum is a waterborne pathogen that has been demonstrated to have a significant reservoir in cattle manure. As agriculture in Wisconsin is famous for its dairy industry, there are approximately 1.3 million dairy cows in Wisconsin in addition to about 250,000 beef cattle. Due to storage and land spreading of animal manure, the risk exists for transport of pathogenic Cryptosporidium spp. to groundwater. Transport of waterborne pathogens to subsurface aquifers has been discounted in the past based on the assumption that physical straining would occur. However, disease outbreak statistics support the proposition that waterborne pathogens can be transported to groundwaters used for drinking water. Therefore, research is needed to understand the potential fate and transport pathways for pathogens such as Cryptosporidium oocysts to drinking water wells. This study has three main objectives: 1) determine whether irradiated C. parvum are effective surrogate soil surface-to-groundwater tracers for future field studies of C. parvum transport; 2) determine the C. parvum fate and transport potential for several Wisconsin soils which have developed overlying northeastern (NE) Wisconsin’s vulnerable carbonate aquifer; and 3) relate the soil C. parvum transport capacity to soil texture, hydraulic conductivity, bulk density, porosity, and hydrophobicity.