The variability of fecal microorganisms and wastewater micropollutants (WWMPs) loads in relation to influent flow rates was evaluated for a water resource recovery facility (WRRF) in support of a vulnerability assessment of a drinking water source. Incomplete treatment and bypass discharges often occur following intense precipitation events that represent conditions that deviate from normal operation. Parasites, fecal indicator bacteria, and WWMPs concentrations and flow rate were measured at the WRRF influent and effluent during dry and wet weather periods. Influent concentrations were measured to characterize potential bypass concentrations that occur during wet weather. Maximum influent Giardia and C. perfringens loads and maximum effluent Escherichia coli and C. perfringens loads were observed during wet weather. Influent median loads of Cryptosporidium and Giardia were 6.8 log oocysts/day and 7.9 log cysts/day per 1,000 people. Effluent median loads were 3.9 log oocysts/day and 6.3 log cysts/day per 1,000 people. High loads of microbial contaminants can occur during WRRF bypasses following wet weather and increase with increasing flow rates; thus, short-term infrequent events such as bypasses should be considered in vulnerability assessments of drinking water sources in addition to the increased effluent loads during normal operation following wet weather.

中文翻译：

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降水对水资源回收设施进水和出水中的寄生虫，指示菌和废水中微污染物负荷的影响。

为支持饮用水源的脆弱性评估，对水资源回收设施（WRRF）评估了粪便微生物和废水微污染物（WWMPs）负荷相对于进水流量的变化。在强烈的降水事件（代表偏离正常操作的状况）之后，经常会发生处理不彻底和旁路排放的情况。在干旱和潮湿天气期间，在WRRF进水和出水处测量了寄生虫，粪便指示细菌和WWMP的浓度和流速。测量进水浓度以表征在潮湿天气期间可能发生的旁路浓度。在潮湿天气期间，观察到最大的贾第鞭毛虫和产气荚膜梭菌载量以及最大的大肠杆菌和产气荚膜梭菌载量。每1,000人的进水隐孢子虫和贾第鞭毛虫的中位载量为6.8 log卵囊/天和7.9 log卵囊/天。每1000人的出水中位数负荷为3.9 log卵囊/天和6.3 log卵囊/天。潮湿天气后，WRRF旁路期间可能会发生大量微生物污染物，并且随着流速的增加而增加；因此，在饮用水源的脆弱性评估中​​，除了在潮湿天气后正常运行期间污水负荷增加以外，还应考虑短期不经常发生的事件，例如旁路。