水厂中的废水流可以包括各种处理工艺产生的水，但大多数是 通常是反冲洗水。其他河流可能包括浓缩机溢流、泻湖污水、工厂排水沟、， 以及来自机械固体脱水设备的废物流。对回收利用的担忧 对于成品水质量是否受到负面影响，存在监管和公共卫生观点。 本文概述了水质标准、研究设计和全面回收的方法 学习两次全尺寸循环流评估的结果（马里兰州巴尔的摩和奥兰治水资源中心） 讨论了下水道管理局（北卡罗来纳州教堂山）。进行这些研究是为了开发一种 全面了解潜在的全面水质影响，并获得监管部门的批准 用于永久性工艺水循环系统的实施。包括2个参考文献、表格和图表。

Waste streams in water plants can include water from a variety of treatment processes, but the majority is typically backwash water. Other streams may include thickener overflows, lagoon effluents, plant drains, and waste streams from mechanical solids dewatering equipment. Concerns about recycle from both the regulatory and public health viewpoint exist over whether finished water quality is negatively impacted. This paper outlines water quality criteria, study design, and approach to full scale recycle studies. The results of two full scale recycle stream evaluations (Baltimore, Maryland, and Orange Water and Sewer Authority, Chapel Hill, North Carolina) are discussed. These studies were conducted in order to develop a thorough understanding of the potential full scale water quality impacts, and obtain regulatory approvals for implementation of permanent process water recycle systems. Includes 2 references, tables, figures.