Water Resources Research Act Program

Details for Project ID 2017SD265B

Evaluating E. coli particle attachment and the impact on transport during high flows (Year 2)

Institute: South Dakota
Year Established: 2017 Start Date: 2017-03-01 End Date: 2018-02-28
Total Federal Funds: $24,946 Total Non-Federal Funds: $49,892

Principal Investigators: Rachel McDaniel, Bruce Bleakley

Project Summary: Nearly 70% of the streams in South Dakota are impaired or threatened of becoming impaired. The most common cause of impairment is bacteria, including E. coli. Recreational waters, such as the Big Sioux River, are a concern for public health as high E. coli concentrations are indicators of fecal pollution. The goal of this study is to evaluate E. coli attachment to particles of different sizes in runoff water and stream water as well as estimate the impact of attachment on E. coli transport during storm events. This will provide additional information about how the bacteria are being transported within across landscapes and in stream environments, the load contribution of each particle size, and an initial estimate of transport distance. Three fields near Coleman, SD will be monitored for E. coli attachment in runoff and Skunk Creek will be monitored for E. coli attachment in stream water. An autosampler has been set up for each of the three field sites along with the Skunk Creek monitoring site to collect water samples. Runoff samples will be collected throughout the hydrograph and stream samples will be collected during three storm events in 30 minute intervals over a 5 hour period. E. coli concentrations will be measured and analyzed for attachment to particles of different sizes using Stoke’s Law and standard membrane filtration. High flow events have been shown to resuspend bacteria from bottom sediments; therefore, the bed shear stress will be compared with the E. coli concentrations associated with different particle sizes. This will provide insight into the force required to resuspend bacteria attached to different sized particles. The transport distance for each particle size will be estimated with information calculated by Stoke’s Law. This will provide information about how many bacteria are being transported over what distance. The ability to better predict movement of E. coli and associated pathogenic microorganisms is of continuing interest and importance to public health authorities, microbiologists, and engineers. It will help confirm the efficacy of practices to control entry of these bacteria into surface waters and help devise future methodologies to better accomplish control.