在澳大利亚南部和东部的条件下，浓度 在六个系统中评估了流域病原体的负载，这些系统跨越了广泛的条件，包括充分保护， 从开阔的放牧区到半农村、密集型（奶制品）区，再到受现场化粪池影响的区域。相比 根据基流病原体浓度，历史上较小的降雨径流事件（1个月） 将微生物参数的浓度提高到四个数量级 量级（即10000倍）和负载通量（污染物单位秒^-1。单位^-1 流域面积）增加7个数量级。观察到的最大值 受影响最大的流域的污染物浓度约为1000 隐孢子虫卵囊。10升100英里每分钟。100毫升弯曲杆菌属。；50,000 mpn。100毫升，大肠杆菌/肠球菌；5000纳克。L^-1，总计。相比之下，从两个 受到充分保护的流域即使在活动期间也几乎没有检测到病原体 在一些主要支流，只有大肠杆菌/肠球菌增加 （与病原体发生无关），强调流域保护的价值。粪便 甾醇/甾烷醇生物标记物提供了事件过程线期间污水影响的证据 在其他情况下，以食草动物为主的粪便污染，这在研究中并不明显 上述微生物检测结果，以及潜在人类病毒的周期 影响这些生物标志物可以估算出从污水中排放的等效废水 城市溪流的化粪池（每天约500000升）。总体风险评估 该矩阵将流域开发、起飞位置和发电水平联系起来 第二轮赛事影响。在径流期间评估流域病原体影响的必要性 无论怎样强调事件都不为过，但很少有人在进行水文取样时报告水文状态 微生物学，事实上，通常会根据这些周期来选择样本。包括16个参考文献、表格和图表。

Under southern and eastern Australian conditions, concentrations and loads of watershed pathogens were evaluated in six systems that spanned a wide range of conditions consisting of fully-protected, open grazing country to semi-rural, intensive (dairy), to on-site septic-impacted. Compared to baseflow pathogen concentrations, historically small rainfall run-off events (1 per mo to 1 in 4 y) increased the concentration of microbial parameters up to four orders of magnitude (i.e. by a factor of 10,000), and the load flux (units of contaminant.sec^-1.unit^-1 area of watershed) by up to seven orders of magnitude. Maximum observed concentrations of contaminants from the most impacted watersheds were ca 1000 Cryptosporidium oocysts.10 L^-1; >100 mpn.100 mL^-1, Campylobacter spp.; 50,000 mpn.100 mL^-1, E. coli/enterococci; and 5000 ng.L^-1, total â-stanols. In contrast, from two fully-protected watersheds almost no pathogens were detected even during event conditions and only E. coli/enterococci increased in some of the major tributaries (unrelated to pathogen occurrence), highlighting the value of watershed protection. Fecal sterol/stanol biomarkers provided evidence of sewage impact during event hydrographs in otherwise herbivore-dominated fecal contamination, which was not evident from the above mentioned microorganism assays, and suggested periods of potential human virus impact. The biomarkers enabled estimates of the equivalent wastewater released from septic tanks to urban streams (ca 500,000 L per day-event). An overall risk assessment matrix was produced that linked watershed development, off-take location and level of run-off event impact. The need to assess watershed pathogen impacts during run-off events can not be overstated, yet few report the hydrological state when sampling for microbiology, and indeed, typically select against such periods to sample. Includes 16 references, tables, figures.