3.3. Safe Drinking Water Act
Under the Safe Drinking Water Act18 EPA must establish national primary drinking water regulations for each contaminant which “may have an adverse effect on the health of persons…” Primary drinking water regulations for each contaminant are to be based on a maximum contaminant level goal (MCLG), set “at a level at which…no known or anticipated adverse effects on the health of persons occur and which allows an adequate margin of safety.” Section 300g-1 National Drinking Water Regulations The MCLG is based upon these health effects. Primary drinking water regulations are to specify a maximum contaminant level (MCL), set as close to the MCLG as is feasible. The term “feasible” is defined in the Act as meaning “feasible with the use of the best technology, treatment techniques, and other means, which…are available (taking cost into consideration).” When establishing MCLs, EPA considers health benefits, particularly residual risk at alternative MCL levels as well as costs and technical feasibility.
When proposing a national drinking water regulation that includes a maximum contaminant level, the EPA shall consider the (1) quantifiable and nonquantifiable health risk reduction benefits that are likely to occur; (2) the quantifiable and nonquantifiable health risk reduction benefits that are likely to occur from reductions in co-occuring contaminants; (3) the quantifiable and nonquantifiable costs that are likely to occur, including monitoring, treatment and other costs; (4) the incremental costs and benefits associated with each alternative MCL; and the effects of the contaminant on the general population and on groups within the population such as infants, pregnant women and individuals with a history of serious illness. At the time the Administrator proposes a national drinking water regulation the Administrator also shall publish a determination of whether the benefits of the proposed MCL justify the costs.