2002年，莫德斯托（加利福尼亚州）灌溉区（区）启动了一项计划，以扩大其灌溉面积 现有的污水处理厂。这一过程设计于20世纪90年代初，当时是美国的最新情况 当时的art，包括预臭氧氧化、絮凝/沉淀和深床 单介质无烟煤过滤。该流程自年启动以来一直行之有效 1994年底，处理了相对高质量的地表水。 在2003年的预设计研究中，运行和维护人员建议 莫德斯托二期扩建中膜过滤的考虑 区域水处理厂，从每天3600万加仑到7200万加仑（mgd）。运行可靠性 而缺乏化学预处理是扩张的两个原因 该设备采用膜过滤技术。 本文讨论了处理工艺的选择，融入现有工艺 流程，以及公司扩建工厂的建议人员要求 夏季产能为72mgd，顺流能力超过85%- mgd。包括表格，如图所示。

In 2002, the Modesto (California) Irrigation District (District) set out on a program to expand their existing treatment works. The process, designed in the early 1990s, was state of the art at the time, consisting of pre-ozonation, flocculation/sedimentation, and deep-bed monomedia anthracite filtration. The process has worked effectively since start-up in late 1994 and treats a relatively high quality surface water. During pre-design studies in 2003, Operations and Maintenance staff suggested consideration of membrane filtration for the Phase II expansion of the Modesto Regional WTP, from 36 to 72 million gallons per day (mgd). Operational reliability and the lack of chemical pretreatment were two of the reasons cited for expanding the facility with membrane filtration technology. This paper discusses the treatment process selection, integration into the existing process, and recommended staffing requirements for the expanded plant with a firm summertime production capacity of 72-mgd with forward flow capability of over 85- mgd. Includes tables, figure.