The policy framework within which we live today was put in place prior to the challenges of our current modern day life and its suitability for the task before us—delivering safe, clean, and adequate supplies of drinking water to people—is being questioned.

Lynn Goldman

Frederick W.Pontius, president of Pontius Water Consultants, Inc. Such decision making cannot be based on science alone. More commonly, it is a blend of science and policy. It is a mixture of different lines of reasoning, different facts, different assumptions, and different judgments made by people with different perspectives. Trac ing the Safe Drinking Water Act (SDWA) from its authorization in 1974 through its various reauthorizations, Pontius posed six questions that underlie the interface of science and policy:

1. How should contaminants be selected for regulation? In 1974, when the SDWA was passed, the U.S. Environmental Protection Agency (EPA) was given discretion—general authority—to regulate contaminants. This resulted in a few regulations, such as those for trihalomethanes, but the pace was slow. So in 1986, Congress mandated regulation of 83 contaminants, whether they needed regulation or not, Pontius noted. Given this large number of required regulations, the contaminants were divided into several phases, each in turn regulating a subset of the 83. There also was a requirement in 1986 to regulate 25 contaminants every 3 years.

Inevitably, the number of contaminants regulated increased (see Figure 1.1). In the early 1990s, policy makers realized that continuing this regulatory pace—principally because of data, but also because of sheer resources—would make it impossible to meet the goals outlined in the 1986 amendment. Thus, in 1996, the law was amended again to mandate future contaminant regulation with contaminants selected from the Drinking Water Contaminant Candidate List (DWCCL). Monitoring of unregulated contaminants was required in order to collect data to determine those that posed the greatest risk. Therefore, in the current selection process EPA considers the available data and makes a determination whether or not to regulate at least five contaminants every 5 years. Meanwhile, the standards for the 83 contaminants that were regulated as a result of the 1986 reauthorization have been retained.

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