Transport of Manure-derived Escherichia coli within Naturally-Fractured Dolomite

Background/Need: The shallow fractured dolomite aquifer represents a major source of domestic water supply in NE Wisconsin. High percentages of domestic wells, however, were found to be contaminated by bacteria and manure was identified as the most likely source. A thorough understanding of the transport behavior of manure-derived bacteria within this aquifer is critical to the assessment of groundwater microbial contamination risks and design and implementation of appropriate mitigation options. However, there is a lack of information on the mechanisms and processes that govern the movement of bacteria within fractured dolomite materials under various water chemistry and flow conditions. This proposed research aims at filling this knowledge gap. Findings from this research will improve our capability of modeling the transport of manure-derived bacteria within fractured dolomite aquifers, and can be used to design new regulation guidelines (e.g., the location and timing of manure application) and to identify wells that are most susceptible to microbial contamination due to manure application.