2000年2月，美国上诉法院确认了下级法院的一项裁决，即美国联邦调查局 填海工程必须为圣路易斯单元的灌溉人员提供排水服务，该单元 占地面积超过70万英亩。填海工程最近完成了一年 努力评估各种替代品，用于处理和处置约 15万英亩英尺/年的排水量，如果分散的话，即每天1.34亿加仑 整年都是均匀的。最终首选方案包括以下内容: 组件: 排水收集和再利用； 生物处理； 海水淡化和 处理到蒸发池。 该项目的下一阶段是可行性研究，包括实地调查 以及详细设计和成本估算的准备。将使用可行性研究 获得国会授权和资金，以实施排水服务和 遵守法庭命令。 水质分析和对未来水质的预测表明 淡化排水系统的巨大挑战。总溶解固体 整个山谷的浓度预计在5000到20000毫克/升之间 在50年的规划期内。回收率将受到硬度的限制，超过 在某些地方，碳酸钙含量为2000 mg/L。排水管中含有硼（>20 mg/L） pH值低于10的反渗透膜不会很好地排斥这种物质。 产品 水将被重新用于商业农业作物的灌溉，其中许多作物 受硼浓度低至5 mg/L的不利影响。山谷土壤 硒被膜很好地排斥到排水中。反过来 因此，渗透浓缩物很难处理，因为它含有 硒含量升高已被证明对现有区域内的野生动物有毒 集中排水的蓄水。 海水淡化的现场调查包括反渗透和渗透的初步试验 在山谷中的两个或多个位置安装纳滤膜。填海是 与加州水资源部、当地农民、水资源部合作 地区和膜制造商进行中试。一个试点系统已经启动 已部署，目前正在评估预处理要求。接下来的六个月 将提供应对挑战所需的信息，确定 成功运行，并进行全面的详细设计和成本估算 海水淡化厂。这部分研究将评估反渗透预处理要求， 性能，以及浓缩物中硒的化学沉淀或吸收。包括3个参考文献、表格和图表。

In February 2000, the U.S. Court of Appeals affirmed a lower court ruling that the US Bureau of Reclamation must provide drainage service to the irrigators in the San Luis Unit which comprises an area of more than 700,000 acres. Reclamation recently completed a yearlong effort to evaluate various alternatives for the treatment and disposal of about 150,000 acre-ft/year of drainwater, that is 134 million gallons per day if spread out evenly throughout the year. The final preferred alternative consists of the following components: drainwater collection and reuse; biological treatment; desalination; and, disposal to evaporation ponds. The next phase of the project is a feasibility study which consists of field investigations and preparation of detailed designs and cost estimates. The feasibility study will be used to obtain congressional authorization and funding to implement drainage service and comply with the court order. Water quality analyses and projections of future water quality indicate there will be substantial challenges for desalting the drainwater. The total dissolved solids concentration is expected to range between 5,000 and 20,000 mg/L across the Valley over the 50-year planning period. Recovery will be limited by hardness which exceeds 2,000 mg/L as CaCO3 at some locations. The drainwater contains boron (>20 mg/L) which is not well rejected by reverse osmosis membranes below pH 10. The product water would be reused for irrigation of commercial agricultural crops, many of which are adversely impacted by boron concentrations as low as 5 mg/L. Valley soils contribute selenium to the drainwater which is well rejected by the membranes. The reverse osmosis concentrate, therefore, will be difficult to dispose of because it will contain elevated levels of selenium that already have proven toxic to wildlife within existing impoundments of concentrated drainwater. The field investigation for desalination involves pilot testing of reverse osmosis and nanofiltration membranes at two or more locations in the Valley. Reclamation is partnering with the California Department of Water Resources, local farmers, water districts, and membrane manufacturers for the pilot tests. A pilot system has been deployed and is currently evaluating pretreatment requirements. The next six months will provide information needed to address the challenges, determine the constraints for successful operation, and perform a detailed design and cost estimate for a full-scale desalination plant. This portion of the study will evaluate RO pretreatment requirements, performance, and chemical precipitation or absorption of selenium from the concentrate. Includes 3 references, tables, figures.