2012 S.C. Water Resources Conference - Exploring Opportunities for Collaborative Water Research, Policy and Managemen

Curtis, Kyle

Trapp, J Michael

English

Clemson University: TigerPrints

printed by www.postersession.com An Investigation into the prevalence, quantification, and survival of Escherichia coli in stormwater basin sediment of Withers Swash, Myrtle Beach, SC  Kyle Curtis, J. Michael Trapp Coastal Carolina University While the presence of fecal indicator bacteria such as Escherichia coli in urban stormwater has been well documented, their occurrence and propagation in sediments are not well understood. Traditionally, fecal bacteria such as E. coli are thought to have short lifetimes in the environment.  Recent research suggests that E. coli can accumulate in the soils, sands, and sediments and can act as a fecal bacterial reservoir within a watershed.  In this study, we investigate the presence, concentration, and survival of E. coli in a variety of sediment types within the Withers Swash tidal creek stormwater catchment area as part of a microbial source tracking project.  By examining the effects of physical and climactic conditions as well as biological inputs we hope to better understand the factors influencing bacterial success in drainage basin sediments.   The Relationship between Sediment Grain Size and Percent Organic Content of Sediment to E. coli Prevalence                                                   Bacterial Reservoir and Flushing Effect                                       Sampling Methodology               Physical Characteristics of Sediment •  Laser diffraction grain size analysis performed on sediment samples from all sites •  Loss on ignition analysis to determine percent organic content             Benchtop Investigations                Boehm, A.B. et al. (2009) Faecal indicator bacteria enumeration in beach sand: a comparison study of extraction methods in medium to coarse sands. Journal of Applied Microbiology 107,1740-1750. Chandran, Abhirosh, et al. (2011) An assessment of potential public health risk associated with the extended survival of indicator and pathogenic bacteria in freshwater lake sediments. International Journal of Hygiene and Environmental Health 214, 258-264. Jamieson, R.C., et al. (2003) Persistence of enteric bacteria in alluvial streams. Environmental Engineering Science 3, 203-212. Jamieson, R.C. et al. (2005) Transport and deposition of sediment-associated Escherichia coli in natural streams.  Water Research 39, 2665-2675.  Jeng H., et al. (2005) Indicator organisms associated with stormwater suspended particles and estuarine sediment. J Environ Sci Health A Tox Hazard Subst Environ Eng. 40, 779-791. Solo-Gabriele, H.M. et al. (2000) Sources of Eschericia coli in Coastal Subtropical Environments. Applied and Environmental Microbiology 66, 230-237.  The purpose of this investigation is based on the need to better understand the factors contributing to bacterial contamination of ambient surface water and stormwater.  Locally, we will examine the impacts of stormwater as it enters Withers Swash, a 303(d) listed tidal creek for fecal indicator bacteria (FIB) that drains an urbanized section of Myrtle Beach, South Carolina.  This research will focus on the contribution of drainage basin sediments, and their potential to act as a bacterial reservoir, to the quality of overlying stormwater entering Withers Swash.  HYPOTHESES •  E. coli will be ubiquitously present in drainage basin sediment during dry weather sampling •  Drainage basin sediments comprised of smaller particles and more organic material will sustain and transport greater concentrations of E. coli between rainfall events •  Rainfall will suspend and transport E. coli adsorbed to sediment particles, resulting in decreased bacterial counts immediately after rain •  Mobilized bacteria from sediment will contribute to overall bacterial counts in stormwater BACKGROUND PURPOSE AND HYPOTHESES MATERIALS AND METHODS PRELIMINARY RESULTS BIBLIOGRAPHY 0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 14 ρ   =  0.6084  Sediment Percent Organic Material –  E. coli Concentration  •  Spearman rank order test used to identify relationships between non-normally distributed data •  ρ values approaching -1 or 1 are indicative of a strong relationship between parameters STUDY AREA Myrtle Beach, SC with Withers Swash highlighted in blue  •  Sediment samples collected before, during, and after rainfall event •  Rainfall event- 72 hours dry conditions prior to rain and at least 0.25” accumulation •  Stormwater samples collected during multiple dry and wet weather events •  3 sub-samples collected from the top 2-5cm at each sampling location, composited into 1 container for transport and analysis •  Sediment and overlying water samples analyzed for presence and quantity of E. coli and total coliform bacteria  Parallel laboratory study investigating environmental factors affecting bacterial success in a microcosm setting  •  bacterial reservoir/flushing phenomena examined  •  the influence of grain size and percent organic material on bacterial recruitment/diffusion •  spiking experiments examining species specific die off curves 0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 14 ρ = 0.5524   Sediment Grain Size- E. coli Concentration 0 1000 2000 3000 4000 5000 6000 Site 3 Site 7 Site 12 E.coli (MPN/g) E. coli (MPN/g) Rain Event Profile Pre Rain Event During Rain Event Post Rain Event Using the data collected thus far we have observed sites that suggest a bacterial reservoir effect may be occurring.  If such an effect were present one would expect an accumulation of high bacterial concentration within the streambed sediment environment relative to the overlying water during dry conditions.   It has been suggested that the sediment-adsorbed bacteria may then be agitated and resuspended during the increased flow associated with a rain event. .   Thus streambed sediments, if capable of harboring bacteria in high concentrations, may act as an additional microbial input to a stormwater system.   Initial result suggest there could be a relationship between both streambed sediment particle grain size, percent organic content, and the prevalence of E. coli bacteria in our study area. 

An Investigation into the Prevalence, Quantification, and Survival of Escherichia coli in Stormwater Basin Sediment of Withers Swash, Myrtle Beach, SC

https://tigerprints.clemson.edu/cgi/viewcontent.cgi?article=1335&amp;context=scwrc

An Investigation into the Prevalence, Quantification, and Survival of Escherichia coli in Stormwater Basin Sediment of Withers Swash, Myrtle Beach, SC

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