Effect of Intra‐Population Variability on the Long‐Distance Transport of Bacteria

Recent experimental work has suggested that within a single bacterial strain there may exist two distinet subpopulations, each with its own sticking efficiency. We performed a sensitivity analysis using an advection‐dispersion model to elucidate the effects of an influent suspension of bacteria composed of two subpopulations, each with distinet sticking efficiencies (dual‐alpha population), on the removal and transport of bacteria over distances of tens of meters. In the simulations, we assumed idealized conditions (i.e., one‐dimensional transport through physically and geochemically homogeneous porous media). Results demonstrate that in cases where a small fraction of the influent bacteria have surface characteristics favorable for transport, the prediction of field‐scale transport based on laboratory‐derived parameters from short column experiments will tend to overestimate substantially the amount of bacterial removal. Results demonstrate the importance of a priori knowledge of the presence of intra‐population variability when predicting the field‐scale transport of bacteria.