1995年，德文郡托尔贝地区爆发了大规模隐孢子虫病 在那里饮用水受到了强烈的牵连。不适宜供水的情况 针对该水务公司提起的人类消费诉讼于上周五被法院驳回 流行病学证据不可接受的理由。政府 因此决定制定新的规章制度，以确保饮用水 处理后充分去除隐孢子虫卵囊。这些规定出台了 1999年6月生效。他们设定的治疗标准平均不到一个月 处理厂供应的10升水中的卵囊，并指定连续 每天至少每小时抽取40升净化水。 英格兰和威尔士的水务公司被要求进行风险评估 他们的每个水处理厂。评估考虑了水源， 提供的集水区和处理方法，并确定是否存在 存在违反标准的重大风险。重大风险分类 这并不意味着违反了标准，而是意味着存在潜在的风险 治疗组有时会出现大量隐孢子虫卵囊 水对于确定存在重大风险的工程，水公司必须处理水 确保符合标准。他们还必须通过以下方式证明合规: 持续监测离开工程的水，并报告施工结果 每日分析。作为连续监测的替代方案，可以安装供水设施 能够连续去除或保留大于 一微米直径。按照目前起草的规定，这些规定要求实际删除 而不考虑卵囊是否具有传染性。

In 1995 there was a large outbreak of cryptosporidiosis in the Torbay area of Devon where drinking water was strongly implicated. The case of supplying water unfit for human consumption brought against the water company was rejected by the Court on the grounds that epidemiological evidence was not admissible. The government therefore decided that new gegulations should be made to ensure that drinking water was treated to adequately remove Cryptosporidium oocysts. These regulations came into force in June 1999. They set a treatment standard of an average of less than one oocyst in 10 litres of water supplied from a treatment works and specify continuous sampling of at least 40 litres per hour of treated water going into supply on each day. Water companies in England and Wales were required to carry out a risk assessment for each of their water treatment works. The assessment considered the source water, the catchment and the treatment provided and established whether there was a significant risk of contravening the standard. The significant risk classification does not imply a contravention of the standard but rather that there is potential for a significant number of Cryptosporidium oocysts to be present at times in the treated water. For works identified as at significant risk, water companies must treat the water to ensure that the standard is met. They must also demonstrate compliance by continuously monitoring the water leaving the works and reporting the results of the daily analysis. As an alternative to continuous monitoring, a water utility may install treatment plants capable of continuously removing or retaining particles greater than one-micron diameter. As currently drafted, the regulations require physical removal of oocysts and do not take into account whether or not oocysts are infectious.