Tom O'Connor

Water treatment plant performance evaluations and operations.

Preface. Chapter 1. Microscopic Particle Analysis. Chapter 2. Plant Process Evaluations. Chapter 3. Lime Softening. Chapter 4. Acidification Protocol. Chapter 5. Filter Operations. Chapter 6. Grit Removal. Chapter 7. Lime Softener Performance Enhancements. Chapter 8. Lime Softener Operational Enhancements. Chapter 9. Granular Activated Carbon. Chapter 10. Plant Operations Manual. Chapter 11. Taste-and-Odor Control. Chapter 12. GAC Adsorption and Microbial Degradation. Appendix A. Procedures for Total Bacterial Cell Count by Epifluorescence Microscopy. Appendix B. Potential Studies Involving Microscopic Particle Analysis: Particle Identification, Enumeration, and Sizing. Appendix C. Development of Operator Guidelines Index.

Water Quality Deterioration in Distribution Systems

Studies were conducted at water utilities in Willmar, MN; Washington, IL and Normal, IL to determine the effectiveness of alternative treatment methods for controlling microbially-mediated water quality deterioration during distribution. Following each study, treatment modifications were made to increase the removal of microbial nutrients which lead to chlorine and oxygen depletion during distribution. A study of copper corrosion in household plumbing at Willmar, MN revealed that the depletion of disinfectant residual was stiochiometrically related to the amount of copper found in solution. Remedial efforts focussed on lowering and maintaining a more stable chloramine residual. Long-term distribution system monitoring to assess chloramine and oxygen persistence was initiated following treatment modifications. Operational changes were made at Washington, IL to accomplish the removal of ammonium ion using cation exchange. During routine softening by cation exchange, ammonium ion is initially removed and, then, released in a large pulse which fosters nitrification and anoxia in the distribution system. To moderate the accumulation of microbial growth in distribution system mains, studies of alternative aeration practices directed at the complete removal of methane were conducted at Normal, IL. Improved aeration has resulted in more persistent disinfectant residuals.