凤凰城目前拥有并运营五座地表水处理厂（WTP），总处理能力为每天6.1亿加仑（mgd）。这些水处理厂的位置及其各自的原水来源如图1所示。五个设施中的三个，瓦尔维斯塔（140 mgd）、鹿谷（150 mgd）和斯阔峰（140 mgd）水处理厂位于盐河项目（SRP）运河系统沿线。除了将SRP运河用作原水来源外，这三个水处理厂还将其残余固体返回运河。由于美国环境保护局（EPA）已将SRP运河确定为“美国水域”，这些排放物须符合国家污染物排放消除系统（NPDES）的许可要求。由于环境保护局目前没有制定水处理厂排放限制的指南，每次排放都将根据具体情况进行评估- 根据具体情况。排放限值的确定可以在成本效益的基础上，使用EPA制定的最佳常规污染物控制技术（BCT）程序来确定。该市沿SRP运河系统运行的水处理厂采用常规处理工艺，如除砂、预沉淀、化学添加、快速混合、絮凝、最终沉淀和过滤。在最初施工时，将废物流排放到SRP运河是一种可接受的做法，因此最初没有建造固体处理设施（SHF）来处理残余废物流。

The City of Phoenix currently owns and operates five surface water treatment plants (WTPs) with a total treatment capacity of 610 million gallons per day (mgd). The locations of these WTPs and their respective raw water sources are illustrated in Figure 1. Three of the five facilities, the Val Vista (140 mgd), Deer Valley (150 mgd), and Squaw Peak (140 mgd) WTPs are located along the Salt River Project (SRP) canal system. In addition to using the SRP canals as a raw water source, these three WTPs also return their residual solids to the canals. Because the US Environmental Protection Agency (EPA) has identified the SRP canals as "Waters of the United States," these discharges are subject to the National Pollutant Discharge Elimination System (NPDES) permitting requirements. Since EPA has no current guidelines for establishing discharge limitations from WTPs, each discharge will be evaluated on a case-by-case basis. The establishment of discharge limits may be determined on a cost effectiveness basis using the Best Conventional Pollutant Control Technology (BCT) procedure as established by EPA. The City's WTPs which operate along the SRP canal system employ conventional treatment processes such as grit removal, presedimentation, chemical addition, rapid mixing, flocculation, final sedimentation, and filtration. At the time of original construction, discharge of waste flow streams to the SRP canals was an acceptable practice, hence no solids handling facilities (SHFs) were initially constructed to process residual waste streams.