Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: November 6, 2000
Publication Date: N/A
Technical Abstract: Cryptosporidium, sometimes associated with infected cattle, is known to cause gastroenteritis in humans. It has been found in many drinking water sources such as rivers, lakes and reservoirs, and is now recognized as an emerging pathogen. Very little is known about the movement of cryptosporidium oocysts through soil into surface waters. We present an overview of a project designed to investigate the near surface transport o cryptosporidium in the vadose zone of a small catchment used for all year round grazing. A 40x30 m site at the outlet of the catchment just above a spring was intensively instrumented to quantify hydrologic balance. Tracer experiment was conducted using bromide and non-reactive polystyrene microspheres as surrogates to cryptosporidium and break through monitored at the spring. Laboratory column studies were conducted to establish parameters for numerical simulation. Characterization of the field site has simproved the understanding of dynamic hydrologic processes. Microspheres were detected in the spring water within 20 days after injection, indicating that particles of this size can migrate quickly through unsaturated soil. We will use results to incorporate trajectory theory of particle transport into an existing model that simulates transport in variably saturated media. The results will help in amelioration efforts to reduces transport of pathogen size particles into surface waters.