本幻灯片介绍了一个案例研究，该案例研究了草坪护理公司的一名员工将花园软管插入一个200加仑的罐中进行填充时发生的回流污染情况，该罐刚刚添加了9夸脱除草剂2-4-D。当Lousiville Water Company的工作人员为进行定期维护工作而关闭总水管时，2-4-D被虹吸回配水管。详细介绍了自来水公司如何处理这种情况，其中包括:确定造成污染的化学物质类型；确定污染物的来源；确定污染程度；通知受影响地区的企业； 联系卫生部门；冲洗水系统；并概述了这项工作所涉及的成本。

This slide presentation describes a case study of a backflow contamination situation that occurred when a lawn care company employee inserted a garden hose into a 200 gallon tank to fill it, having just added 9 quarts of the herbicide 2-4-D to the tank. When the Lousiville Water Company crew turned off the water main for scheduled maintenance work, the 2-4-D was back-siphoned into the distribution water main. Details are given of how the water company handled the situation, which included: determining the type of chemical that caused the contamination; locating the source of the contaminate; determining the extent of the contamination; notifying businesses in the impacted area; contacting the Health Department; flushing the water system; and, outlining the costs involved in the effort.