匹兹堡供水和污水管理局（Pittsburgh water and Sewer Authority）面临着覆盖1.25亿加仑（0.4 x 10（6）-m3）容量的水库的州授权，以及公众反对使用浮式覆盖物的情况，探索了水库后处理方案的可能性。监管机构表示，任何可接受的后处理必须确保病毒减少4对数，贾第虫减少3对数，隐孢子虫减少2对数。当局研究了臭氧氧化和膜过滤的应用。臭氧灭活试验导致隐孢子虫卵囊在实验室规模上灭活1.0-1.2对数，在中试规模上灭活0.2-0.5对数。膜过滤挑战性研究表明，贾第虫囊肿的去除率为5对数，隐孢子虫卵囊的去除率为6对数。根据试点测试结果和其他考虑因素，管理局正在构建一个20- mgd（0.07 x 10（6）-m3/d）微滤装置，用于处理从成品水池流出的水。包括17个参考文献、表格、图表。

Faced with a state mandate to cover a 125-mil-gal- (0.4 x 10 (6)-m3-) capacityfinished water reservoir and with public opposition to using a floating cover, the Pittsburgh Water and Sewer Authority explored the possibility of postreservoir treatment options. The regulatory agency indicated that any acceptable posttreatment must ensure 4-log reduction of viruses, 3-log reduction of Giardia, and 2-log reduction of Cryptosporidium. The authority studied ozonation and membrane filtration for this application. Ozone inactivation trials resulted in a 1.0- to 1.2-log inactivation of Cryptosporidium oocysts at bench scale and 0.2- to 0.5-log inactivation at pilot scale. Membrane filter challenge studies demonstrated a 5-log removal of Giardia cysts and 6-log removal of Cryptosporidium oocysts. Based on the results of pilot testing and additional considerations, the authority is constructing a 20-mgd (0.07 x 10(6)-m3/d) microfiltration plant to treat water leaving the finished water reservoir. Includes 17 references, tables, figures.