Introduction to Drinking Water Risk Assessment

The need for a clean and safe drinking water supply for centers of population has been recognized for over 2000 years. The early Romans recognized that human activities and effluent were a major source of water pollution, and that providing water from relatively unpopulated areas was a solution to the problem. In 312 b.c. the Romans under Appius Claudius began development of an aqueduct system to deliver water taken from the Tiber River upstream of the city, thus improving the quality and quantity of their water supply (Okun, 2003). It has been said that the availability of a good water supply through their extensive aqueduct system enabled the rise of Rome as a center of civilization—and it has also been speculated that the use of lead for water pipes helped lead to its downfall, through slow poisoning of the population. This has been disputed, with evidence that terra-cotta was a preferred piping material, resulting in better-tasting drinking water. Thus, the maintenance of drinking water quality has been a major quest throughout the development of modern civilization. However, it was not until the efforts of John Snow in 1854, analyzing a cholera epidemic in London, that specific diseases were shown to be associated with drinking waters that looked and tasted clean. For those who may not have heard the story, John Snow, a London doctor, noticed that many of the people who died of cholera in that summer’s epidemic had a common factor; they all obtained their drinking water through the Broad Street well. He had the pump handle removed and the epidemic faded away. For this analysis and his subsequent publications,