The microbial quality of two groundwater sources (well and borehole) and associated risks were quantitatively assessed. Water samples from the selected borehole and well were collected over a period of 12 weeks (n = 48). The concentrations of Escherichia coli, faecal coliforms, Salmonella, Shigella, Clostridium, Bifidobacterium and Campylobacter were determined using standard microbiological methods, which involve the use of a membrane filter technique. The water samples were filtered through a 0.45 μm membrane filter using vacuum pump pressure and plated on selective agar for the bacteria under test. The number of colonies of the bacterial growth observed after the incubation period was counted and recorded. The physicochemical properties of the water were determined using standard methods. The risk of Salmonella, Shigella, Clostridium and Campylobacter infections resulting from the ingestion of water from the borehole and well was estimated. The results showed that the levels of enteric bacteria in the borehole were higher than those in the well. The mean levels of E. coli in water from the borehole and well were 3.3 and 1.7 log₁₀ cfu/100 ml, respectively, and exhibited a negative relationship with salinity (r = −0.53). The estimated risks of infection associated with the pathogens in water from the borehole and well were greater than the acceptable risk limit of 10⁻⁴ and followed this order Clostridium<Salmonella<Campylobacter<Shigella. The findings of this study suggest recent and continuous faecal contamination of the two groundwater sources, thus exposing the residents relying on the water for drinking to potential risks of gastrointestinal infections.

对两种地下水源（井和井眼）的微生物质量和相关风险进行了定量评估。在12周内（n = 48）从选定的井眼和井中收集了水样。大肠杆菌，粪便大肠菌群，沙门氏菌，志贺氏菌，梭菌，双歧杆菌和弯曲杆菌的浓度使用标准微生物学方法测定，其中包括使用膜滤器技术。使用真空泵压力将水样品通过0.45μm的膜滤器过滤，并铺在选择性琼脂上以供待测细菌使用。计数并记录潜伏期后观察到的细菌生长的菌落数。使用标准方法确定水的理化性质。估计了由于摄入井眼和井中的水而导致沙门氏菌，志贺氏菌，梭菌和弯曲杆菌感染的风险。结果表明，井眼中的肠细菌水平高于井中的肠细菌水平。井眼和井中水中的大肠杆菌平均水平分别为3.3和1.7 log ₁₀ cfu / 100 ml，与盐度呈负相关（r = -0.53）。与井眼和井中水中的病原体相关的估计感染风险大于可接受的风险极限10 ^-4，并且遵循此顺序梭状芽孢杆菌<沙门氏菌<弯曲杆菌<志贺氏菌。 这项研究的结果表明，最近和连续的粪便污染了这两种地下水源，从而使依靠水饮用的居民面临胃肠道感染的潜在风险。