An Analysis of Jordan Lake Water Quality and its Impact on the Cary/Apex Water Treatment Facility
Public Deposited- Last Modified
- February 28, 2019
- Creator
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Kelly, Eric J.
- Affiliation: Gillings School of Global Public Health, Department of Environmental Sciences and Engineering
- Abstract
- Understanding the variability in raw water quality at water treatment plant intakes is important because the variations will affect the water treatment plant's processes, chemical usage, and chemical costs. The variation in raw water quality of Jordan Lake was analyzed to evaluate its influence on the Cary/Apex water treatment facility. This process included assessing seasonal fluctuations in coliform bacteria, examining correlations between coliform bacteria and other source water quality parameters such as turbidity and temperature, and exploring relationships between source water quality parameters and chemical usage and corresponding chemical costs using linear regression analysis. The results obtained for Jordan Lake and the Cary/Apex water treatment facility were compared to those for Falls Lake and the Raleigh water treatment facility. A strong correlation was observed between coliform bacteria counts and water temperature for both of the source waters. Surprisingly, a weak correlation was observed between coliform bacteria counts and turbidity, despite the fact that turbidity is used as a surrogate for microbial contamination. The extent of microbial inactivation, in terms of residual disinfectant concentrations times contact time(CT), ranged between 3 and 38 times and between 3 and 24 times the required CT for the Cary/Apex and Raleigh water treatment plants, respectively. A greater excess in activation potential was exhibited during the warmer summer months, the period of the year when consumer water demand and coliform bacteria counts are at their highest levels. A multiple linear regression analysis relating chemical cost with various source water quality parameters at the Gary/Apex facility proved to be insignificant at best, with an R^2 value of 0.30. Alum dosages were relatively constant throughout the year, despite seasonal fluctuations in source water quality.
- Date of publication
- December 2007
- DOI
- Resource type
- Rights statement
- In Copyright
- Advisor
- Singer, Philip
- Characklis, Gregory
- DiGiano, Francis A.
- Degree
- Master of Science in Environmental Engineering
- Academic concentration
- Environmental Engineering
- Degree granting institution
- University of North Carolina at Chapel Hill
- Graduation year
- 2007
- Language
- Deposit record
- e00f1df6-6c31-41ba-867b-150d86a8c8cb
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