Contamination accidents in China's drinking water distribution networks: status and countermeasures

In recent years, frequent urban drinking water contamination accidents have caused significant impacts on society in China. However, emergency measures are primarily realized as management policies lack systematic technologies especially for those within-network contamination accidents. The aim of this paper is to perform analysis on cases of contaminant accidents that occurred in water distribution networks and to propose a framework of emergency response technologies. The causes, impacts, and characteristic trends of urban water supply contamination accidents are analysed according to the data of eighteen typical contamination cases that have been publicly reported in China since 2003. The results show that the main problems for rapid response to those accidents are: (1) limited monitoring means; (2) lag in response, especially the lag in providing an explanation to the public; and (3) lag in recovery from the accident. To solve those problems, a framework of technological strategy for rapid response to contamination accidents including monitoring, identifying, evaluation, isolation and flushing is then proposed. Since drinking water contamination accidents are not a unique problem that only happens in China, the response policy and related technologies proposed in this paper are also applicable to other countries and regions that face the same problems.