Microbial and chemical contamination of groundwater around livestock mortality burial sites in Korea - a review

This review defines and discusses type and fate of microbial contaminants expected to be found in the groundwater around livestock mortality burial pits. Reported results from simulated and actual mortality burial pits indicate that decomposition process of animal carcass requires at least 2 years for completion, generating the leachate with very high concentrations of chemical pollutants. These chemical constituents are likely to provide substrate for bacterial growth and affect microbial population dynamics in the subsurface. Anticipated microbial pollutants are classified into 3 categories. (1) enteric microorganisms including disease causing viruses, (2) bacteria participating in carcass decomposition, such as proteolytic and lipolytic bacteria, and (3) endogenous soil microorganisms. Experimental and field data indicate that pathogenic enteric viruses and bacteria may be able to survive in the animal body and natural environments for extended periods of time when ambient conditions are suitable for their survival. Proteolytic bacteria may affect pathogenicity of avian influenza viruses by controlling their cellular attachment and infiltration. Pathogenic soil bacteria can experience shift in population dynamics, with the introduction of leachate chemicals, from attached bacterial community with limited size to exponentially growing suspended biomass accustomed to the conditions in the groundwater. The possibility of extended survival of various sources of microbial contamination indicates the need to set up a method to properly monitor groundwater contamination to identify the presence of microbial contaminants and their interaction with chemical constituents.