抗氯病原体隐孢子虫的出现意味着，不使用物理或物理化学屏障的简单处理过程已不足以保证保护公众免受水传播疾病的影响。1993年在坎布里亚西部爆发了与供水有关的隐孢子虫病后，西北水务公司（NWW）开始建造一座工厂，为隐孢子虫提供强大而可靠的屏障。历史上，英格兰西北部这一地区的水源被归类为高质量，即低浊度和低颜色。因此，仅要求进行粗微污染，然后用氯消毒，并用石灰提高pH值，以符合EC饮用水指令。 本文介绍了该项目的方法，包括:现场试验；膜系统的选择标准；自1999年底以来该系统的运行经验；并将该系统的性能与试点结果进行了比较。包括11个参考文献、表格、图表。

The emergence of the chlorine resistant pathogen Cryptosporidium has meant thatsimple treatment processes that do not employ either a physical or physiochemicalbarrier are no longer adequate to guarantee protection of the public fromwaterborne disease. Following an outbreak of cryptosporidiosis in West Cumbria in1993 associated with the water supply, North West Water (NWW) embarked on a planto provide a robust and reliable barrier to Cryptosporidium. Historically, thewater sources in this part of the North West of England have been classed as highquality, i.e., low turbidity and color. Consequently, only coarse microstrainingfollowed by disinfection with chlorine and pH elevation with lime has beenrequired to comply with the EC drinking water directive. The paper describes theapproach to the project including the: site pilot trials; selection criteria forthe membrane system; operating experience of the system since late 1999; and,performance of the system compared to the pilot trial results. Includes 11 references, tables, figures.