ARS | Publication request: Including the resuspension of the streambed E. coli in the Soil and Water Assessment Tool (SWAT)

Submitted to: Computers in Agriculture
Publication Type: Abstract Only
Publication Acceptance Date: February 5, 2009
Publication Date: N/A

Technical Abstract: Streambed sediments have been shown to serve as environmental reservoirs for bacteria, including pathogenic strains. The purpose of this work was to expand the in-stream bacteria fate and transport module of the Soil and Water Assessment Tool (SWAT) by including the transport of bacteria caused by the bottom sediment resuspension, and to evaluate the potential significance of bacteria resuspension for the SWAT bacteria quality simulations. In the newly developed module, bacteria from the bed sediment entered the stream water via resuspension, and a fraction of sediment associated bacteria settled with depositing sediment. Monitoring data from the Little Cove Creek watershed, Pennsylvania, were used to evaluate the module. The seasonal trends of bacteria concentrations in sediment and stream water were similar. The simulated E. coli input into the stream water from the bed sediment was comparable with or larger than the simulated E. coli input from the pasture runoff. The contribution of sediment resuspension could explain the E. coli persistence in stream water during cold periods. Results of this work indicate the need in gathering experimental information on fate of pathogen and indicator bacteria in streambed sediments to improve predictions of bacterial water quality.