Document Type
Thesis - University Access Only
Award Date
2007
Degree Name
Master of Science (MS)
Department / School
Civil and Environmental Engineering
Abstract
The microbiological deterioration of drinking water during distribution is a concern for all potable water suppliers. Although not a regulatory enumeration method, bulk water heterotrophic plate counts (HPC) can give insight into the bacterial quality of distributed drinking water. In addition, elevated levels of heterotrophic plate counts are often associated with aesthetic deterioration, nitrification episodes, haloacetic acid biodegradation, and corrosion. In response to a limited availability of HPC data in South Dakota, a survey was conducted to identify the prevalence of heterotrophic bacteria in South Dakota water distribution systems. Further research was employed to correlate heterotrophic plate counts with system characteristics including source water, temperature, disinfectant residual, disinfectant type, turbidity, pH, TOC, and pipe material. As a final objective, the day-to-day variability of bacterial activity was assessed. The project revealed that planktonic heterotrophic bacteria were indeed present in South Dakota water distribution systems and were quite prevalent in some locations. In addition, the research demonstrated that disinfectant residual was the main factor controlling bacterial levels, especially with systems utilizing chlorarnine disinfectant. Temperature was found to be an influential bacteriological parameter, but only when residual levels were depleted. Pipe composition also tended to be an influential system characteristic. Further research proved that heterotrophic bacteria populations fluctuate on a day-to-day basis.
Library of Congress Subject Headings
Water quality management -- South Dakota
Water -- South Dakota -- Distribution
Water -- Microbiology -- Technique
Plate counts (Microbiology)
Drinking water
Bacteria, Heterotrophic
Format
application/pdf
Number of Pages
195
Publisher
South Dakota State University
Recommended Citation
Engel, Weston M., "The Presence of Heterotrophic Plate Counts in South Dakota Water Distribution Systems and Their Correlation with System Characteristics" (2007). Electronic Theses and Dissertations. 1375.
https://openprairie.sdstate.edu/etd2/1375