Date of Award

7-2008

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Environmental Engineering and Science

Advisor

Elzerman, Alan W

Committee Member

Coates , John T

Committee Member

Lee , Cindy M

Abstract

Fecal sterols and fluorinated whitening agents (FWA) were used as chemical tracers for fecal coliform source tracking in Cane and Little Cane creeks in Walhalla, SC. Fecal sterols were quantifiable in both stream sediments and suspended particulates using an extraction, clean-up, and analytical method modified from Isobe et al. (2002) with a N,O-Bis(trimethylsilyl)trifluoroacetamide (BSTFA) derivatization scheme. Only human sterol source identification ratios were able to be calculated using the chosen sterol suite. Human fecal signatures were seen in both the sediment and the water column at various points along both creeks, indicating human fecal pollution is contributing to the fecal coliform pollution. Because there was little deposition of sediment at sampling sites along the creeks and the sterol loading on suspended particulates was about the same or greater than that in the sediment, it is recommended that future studies on this system concentrate on quantifying fecal sterol loadings in the water column. Further, water column samples will provide an instantaneous picture of fecal loadings. Sediment samples are easier to process and may be useful for specific investigations. Results were compared to microbial source tracking (MST) methods by a collaborating researcher and showed consistencies for only some of the sample sites, which may have been due to false negatives or differences in sampling dates and matrices. FWA was never above presumptive sewage detection levels in the creeks even when sediment samples indicated some historical human fecal pollution at sites. Due to its specificity for human input and the apparent requirement of significant levels to give a positive signal, it is suggested that FWA analysis be discontinued unless a significant human fecal input is suspected. An expanded study is recommended to compare fecal sterols in the water column during base and storm flow using the method developed here and an expanded sterol suite to correlate fecal loadings with different sources in the watershed. Using this information, BMPs could be implemented with a focus on addressing actual fecal loadings. The method could also be used to help quantify surface water quality improvements after BMP implementation.

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