AWWA ACE58177

The San Francisco Public Utilities Commission (SFPUC) serves 2.3 million wholesale and retailcustomers in the San Francisco Bay area. The SFPUC's primary source of supply (about 85% ofthe annual supply) is the Hetch Hetchy Reservoir located in Yosemite National Park. The HetchHetchy watershed is of such pristine quality that the SFPUC was granted and maintains filtrationavoidance for this supply. Currently the Hetch Hetchy supply is treated with lime for pHadjustment and disinfected with sodium hypochlorite as it travels 130 miles to the Bay Area.SFPUC is interested in alternative disinfectants for compliance with the Long Term 2 EnhancedSurface Water Treatment Rule (LT2ESWTR) and is currently considering ultraviolet (UV) disinfection at itsHetch Hetchy supply. Thus, knowing how transmittance varies with raw water quality will beessential in the evaluation of UV as an alternative disinfectant. Transmittance data are alsocritical to the selection, design, and operation of UV disinfection equipment, and will continue tobe used in the day-to-day operation and control of the UV disinfection system. The findings ofthis analysis will form the basis for selecting a transmittance monitoring sampling program andfor determining how to incorporate on-line measurements with grab samples. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

06/15/2003

Number of Pages:

13

File Size:

1 file , 940 KB