Evaluation of a filtration/dispersion method for enumeration of particle-associated Escherichia coli.

The transport processes of microorganisms in storm-generated flows have not been clearly elucidated, limiting the ability of computational models to effectively design and evaluate watershed remediation plans. Although several studies have identified association with particulates as a critical factor in predicting microbial transport and fate, no generally accepted method exists for the identification of the planktonic and particle-associated fractions of microorganisms in water samples. In this study, a filtration/dispersion method proposed for quantification of these fractions was verified using laboratory-composed samples of bovine Escherichia coli and sterile topsoil.

Development of bacteria and benthic total maximum daily loads: a case study, Linville Creek, Virginia.

Two total maximum daily load (TMDL) studies were performed for Linville Creek in Rockingham County, Virginia, to address bacterial and benthic impairments. The TMDL program is an integrated watershed management approach required by the Clean Water Act. This paper describes the procedures used by the Center for TMDL and Watershed Studies at Virginia Tech to develop the Linville Creek TMDLs and discusses the key lessons learned from and the ramifications of the procedures used in these and other similar TMDL studies.