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Title: PREDICTING THE MICROBIAL CONTAMINATION OF SOILS OF RIVER VALLEYS

Author
item DEVIN, BORIS - I.OF SOIL SCIENCE,RUSSIA
item SHEIN, EUGENY - MOSCOW STATE UNIVERSITY
item Pachepsky, Yakov
item Shelton, Daniel

Submitted to: International Conference on Ecology of River Basins
Publication Type: Proceedings
Publication Acceptance Date: 8/15/2005
Publication Date: 9/28/2005
Citation: Devin, B.A., Shein, E.V., Pachepsky, Y.A., Shelton, D.R. 2005. Predicting the microbial contamination of soils of river valleys. International Conference on Ecology of River Basins. September 28-30, 2005, Vladimir, Russia. pp.63-65.

Interpretive Summary: Preventing contamination of the ground water and surface waters is very important for the public health. Soil is traditionally regarded as a filter that blocks contaminants and pathogens from entering the groundwater and rivers. However soil is a heterogeneous medium; it contains macropores that can work as the pathways of the preferential transport of dissolved or suspended material. The objectives of this work were (1) to analyze transport of microorganisms in soil using the approaches and methodologies of contaminant hydrology and (2) to evaluate possible fate of microorganisms in the landscape. Bacterial transport was studied by observing breakthrough of two bacteria with infiltrating water in soil columns. After the bacteria plug infiltrated, the distilled water was allowed to infiltrate into soil. Cross-sections of the columns were analyzed using the luminescent microscopy. The breakthrough indicated that clusters of bacterial cells were formed in the water flow in soil. The faster water infiltrated the less bacteria were strained or adsorbed in soil. Bacteria transport in soil occurred preferentially through the larger pores. In case of a microbial contamination of the region of this study, a fast transport of the pathogenic microorganisms within the lower sandy horizon down to groundwater is quite probable, especially in the upper part of the slope with high location of sandy layers. The upper soil could impede the vertical bacteria transport. However in cases of the strong rain storm events that often occur in this area in the middle of summer, the lateral transport of bacteria along with soils particles is quite possible.

Technical Abstract: Preventing contamination of the alluvial soils is very important for the public health. Soil is traditionally regarded as a filter that blocks contaminants and pathogens from entering the groundwater and rivers. However soil is a heterogeneous medium; it contains macropores that can work as the pathways of the preferential transport of dissolved or suspended material. The objectives of this work were (1) to analyze transport of microorganisms in soil using the approaches and methodologies of contaminant hydrology and (2) to evaluate possible fate of microorganisms in the landscape. Bacterial transport was studied by observing breakthrough of two bacteria with infiltrating water in soil columns. After the bacteria plug infiltrated, the distilled water was allowed to infiltrate into soil. Cross-sections of the columns were analyzed using the luminescent microscopy. The breakthrough indicated that clusters of bacterial cells were formed in the water flow in soil. The faster water infiltrated the less bacteria were strained or adsorbed in soil. Bacteria transport in soil occurred preferentially through the larger pores. In case of a microbial contamination of the region of this study, a fast transport of the pathogenic microorganisms within the lower sandy horizon down to groundwater is quite probable, especially in the upper part of the slope with high location of sandy layers. The upper soil could impede the vertical bacteria transport. However in cases of the strong rainstorm events that often occur in this area in the middle of summer, the lateral transport of bacteria along with soils particles is quite possible.