旧金山公用事业委员会（SFPUC）服务230万批发零售 旧金山湾地区的客户。SFPUC的主要供应来源（约85% 年供水量）是位于约塞米蒂国家公园的Hetch Hetchy水库。海奇 Hetchy流域具有如此原始的质量，因此SFPUC被授予并保持过滤 避免这种供应。目前，Hetch-Hetchy供应用石灰处理pH值 调整并用次氯酸钠消毒，因为它将行驶130英里到湾区。 SFPUC对替代消毒剂感兴趣，以符合长期2增强型 地表水处理规则（LT2ESWTR），目前正在考虑紫外线（UV）消毒 Hetch Hetchy供应。因此，了解透射率随原水质量的变化将是非常重要的 在评估紫外线作为替代消毒剂时至关重要。透射率数据也很重要 对紫外线消毒设备的选择、设计和操作至关重要，并将继续 用于紫外线消毒系统的日常操作和控制。 调查结果 该分析将构成选择透射率监测采样程序的基础，以及 用于确定如何将在线测量与抓取样本结合起来。包括表格、数字。

The San Francisco Public Utilities Commission (SFPUC) serves 2.3 million wholesale and retail customers in the San Francisco Bay area. The SFPUC's primary source of supply (about 85% of the annual supply) is the Hetch Hetchy Reservoir located in Yosemite National Park. The Hetch Hetchy watershed is of such pristine quality that the SFPUC was granted and maintains filtration avoidance for this supply. Currently the Hetch Hetchy supply is treated with lime for pH adjustment 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 Enhanced Surface Water Treatment Rule (LT2ESWTR) and is currently considering ultraviolet (UV) disinfection at its Hetch Hetchy supply. Thus, knowing how transmittance varies with raw water quality will be essential in the evaluation of UV as an alternative disinfectant. Transmittance data are also critical to the selection, design, and operation of UV disinfection equipment, and will continue to be used in the day-to-day operation and control of the UV disinfection system. The findings of this analysis will form the basis for selecting a transmittance monitoring sampling program and for determining how to incorporate on-line measurements with grab samples. Includes tables, figures.