OPTIMIZING PERFORMANCE OF A 105 MGD MEDIUM PRESSURE UV DISINFECTION SYSTEM BY USE OF A COMPUTERIZED OPERATIONS MANUAL

The Clark County Sanitation District (CCSD) installed a medium pressure ultraviolet (UV) disinfection system to treat up to 105 million gallons per day (mgd) of filtered secondary effluent prior to its discharge to the Las Vegas Wash, a subsidiary of the Lake Mead reach of the Colorado River. The project also included construction of a sodium hypochlorite system for in-plant chlorine requirements, such as filter prechlorination and plant water disinfection. The hypochlorite feed facility was used for interim disinfection during construction and will serve as emergency backup to the UV disinfection equipment on a long-term basis. A small sodium bisulfite dechlorination system was also installed for backup use. The project allowed the CCSD to decommission bulk chlorine and sulfur dioxide storage tanks prior to the Environmental Protection Agency's deadline for preparation of a risk management plan for the plant. The UV disinfection and chemical feed system was designed by Kennedy/Jenks Consultants and Brown and Caldwell.A computerized operations and maintenance (O&M) manual was prepared prior to startup of the UV disinfection and chemical feed systems. The computerized manual is browser-based and allows plant operators immediate access to routine and emergency operating instructions and links to manufacturer's information, design drawings, equipment submittals and specifications. The preparation and use of the computerized manual is discussed in this paper.