M. W. LeChevallier – författare

The primary objective of the project was to characterize raw water, treatment plant, distribution, and household tap water quality with respect to microbes, water quality indictors, and physicochemical parameters in Davenport, Iowa. The goal was to provide a context for interpreting the public health data generated by the epidemiology study. In response to the 1996 amendments to the Safe Drinking Water Act requirements, the U.S. Centers for Disease Control and Prevention (CDC) and the U.S. Environmental Protection Agency (USEPA) formulated a series of epidemiology studies to determine the occurrence of waterborne disease in the United States. The Iowa-American Water Company, Davenport district, was selected because it best satisfied all of the study criteria.? Detailed analyses were conducted on raw, treated plant effluent, distribution system, and household tap and treatment device water samples. The findings of the separately funded epidemiology study will have a tremendous impact on the perception and regulation of drinking water. This study demonstrated that the water supply studied met or surpassed all measures of water quality. The outcome of the epidemiology study (whether waterborne disease is observed or not) will either support current standards of drinking water quality, or radically change the approach to ensuring potable water. Originally published by AwwaRF for its subscribers in 2003.

Sudden valve closures can create rapid changes in water velocity that result in transient pressure conditions. Pressure transients can travel throughout a distribution system and cause low or negative pressures. Contamination may occur if a leak or air-vacuum valve is submerged and a low pressure wave passes through the pipeline. Pressure transients may be initiated by regular water distribution system operations. Therefore, pressure transients may occur frequently in certain water distribution systems. The objectives of this project were to verify that low and negative pressure transients actually occur in real distribution systems (not just within large transmission mains) and that they can cause contaminants external to the pipe to be intruded into a drinking water main through a leak or orifice. The research strategy for this project was divided into five primary tasks: (1) an expert panel workshop; (2) design and construction of a pilot-scale test rig and associated testing to measure intrusion volumes under various operating conditions; (3) field studies including pressure monitoring in seven full-scale distribution systems plus comparison of mechanical pen and chart recorders, data collected by SCADA systems, and high-speed data loggers; (4) evaluation of the capabilities of full-scale hydraulic surge modeling; and (5) development of a surge control program and control strategy guidelines.

Water quality management has many dimensions including operations support, laboratory management, project planning, data management, research, technological applications, staff development, customer satisfaction, budget management, technological advancements and regulatory compliance. Water utilities have developed pragmatic organizational and strategic methods to manage these responsibilities, and their water quality managers have acquired substantial related expertise. This experience can be used by other water utilities seeking to improve their water quality management performance. Originally published by AwwaRF for its subscribers in 2004.