石灰岩蓄水层可能容易受到来自遥远来源的粪便污染，德克萨斯州乔治敦市爆发的病毒性胃肠炎和肝炎就证明了这一点。疫情爆发后，水质分析在该市的水井、下水道和饮用水系统中检测到人类肠道病毒和甲型肝炎病毒。描述了氯化过程中的变化。不应假设地下水的纯度，即使未检测到细菌污染，也应进行病毒污染监测。包括14个参考文献、表格和图表。

Limestone aquifers may be susceptible to fecal contamination from distant sources, as evidenced by an outbreak of viral gastroenteritis and hepatitis in Georgetown, Texas. After the outbreak, water analyses detected human enteric viruses and hepatitis A virus in the city's wells and sewer and potable water systems. Changes in the chlorination process are described. Groundwater purity should not be assumed, and monitoring for viral contamination should be undertaken even if no bacterial contamination is detected. Includes 14 references, tables, figure.