有效的常规慢速砂滤器的使用通常仅限于优质原水 颜色、浊度和藻类含量低的来源。常规慢砂滤池 工厂通常也采用定制工程，并采用现浇混凝土建造 这会使这种处理方案在小型系统中的资本成本相对较高 （<0.5 MGD容量）。本文介绍了最近的预处理增强 这在现场已被证明对延长慢砂过滤过程有效 对于边际供水水源，以及一个前- 编造 臭氧/粗滤器/慢速砂滤器安装在缅因州北黑文。包括7个参考文献、表格和图表。

Effective conventional slow sand filter use is typically limited to good quality raw water sources that are low in color, turbidity, and algal content. Conventional slow sand filter plants are also typically custom-engineered and constructed with cast-in-place concrete that can make this treatment option relatively high in capital cost for small systems (<0.5 MGD capacity). This paper presents recent pretreatment enhancements that have been proven effective in the field for extending the slow sand filtration process for marginal water supply sources, along with a case study of a pre-fabricated ozone/roughing filter/slow sand filter installation in North Haven, Maine. Includes 7 references, tables, figure.