R.C.Willson水处理厂是马里兰州哈格斯敦市运营的传统水处理厂。该工厂处理从波托马克河抽取的水，并直接将用过的过滤器反冲洗水回收至工厂进水。在沉淀处理之前，对过滤器进行一些回流处理。然而，最近，美国环境保护署和马里兰州环境部（MDE）都对回收过滤器反冲洗水可能产生的负面微生物影响表示担忧。本研究的主要目的是:研究过滤反冲洗废水循环对颗粒去除效率的影响；根据MDE制定的标准评估现有回收系统的充分性；确定滤池反冲洗废水回用对工厂进水水质的影响； 确定预沉淀池均衡和去除过滤器反冲洗废水中颗粒和浊度的有效性。

The R.C. Willson Water Treatment Plant is a conventional WTP operated by the City of Hagerstown, Maryland. The plant treats water withdrawn from the Potomac River and directly recycles the spent filter backwash water to the plant influent. Some treatment of the recycled filter backwash is provided by presedimentation prior to coagulation. Recently, however, both the US Environmental Protection Agency and the Maryland Department of the Environment (MDE) have expressed concern about the potential negative microbial impacts of recycling filter backwash water. The main objectives of this study were to: investigate the filter backwash wastewater recycle impacts on the efficiency of particle removal; evaluate the adequacy of the existing recycle system based on the standards established by the MDE; determine the impacts on plant influent quality from the reuse of filter backwash wastewater; and, determine the effectiveness of the presedimentation basins for equalizing and removing particles and turbidity from the filter backwash wastewater.