“EPA admits that it has established an RMCL for fluoride at a level which will not protect sensitive subgroups against crippIing skeletal fluorosis and other health effects. This clear violation of the Safe Drinking Water Act (“SDWA” or “the Act”) should be remanded to the Agency for determination of an RMCL consistent with the Agency’s duty to protect susceptible sbbgroups of the population.

EPA claims that only a small number of persons are likely to be harmed by exposure to fluoride at the RMCL. The record shows, however, that fluoride concentrations at and below 4 mg/L could cause crippling skeletal fluorosis and other clinical skeletal effects in a substantial number of people. EPA made no effort to determine the number of people who will be harmed. Instead of evaluating all pertinent information (as it says it did), the Agency ignored documentation of severe skeletal effects in kidney patients, failed to address dangers to other groups such as diabetics, and entirely overlooked potential dangers to children.

The Agency’s own drinking water intake data show significant risk of crippling skeletal fluorosis in populations exposed to fluoride concentrations of 4 mg/l, even when the data are used cautiously. EPA did not mention or show any awareness of the implications of these data. EPA should have set an RMCL to provide a margin of safety for the highest consumers of water; instead, it provided a small margin of safety only for persons who drink 2 liters of water or less per day.

Finally, the two epidemiological studies of skeletal effects of fluoride heavily relied upon by EPA fall far short of demonstrating that fluoride concentrations up to 4 mg/L will not harm a substantial portion of the population. EPA made no effort to ascertain the reliability of the studies; and the Agency’s brief erroneously assumes that the studies “necessarily account for” sensitive subgroups.

EPA’s response to NRDC’s challenge is to ask this Court to defer to the Agency’s judgment and thereby create a judicial exception to the mandate of the SDWA that an RMCL must provide protection to all persons against known and anticipated health effects of drinking water contaminants. The RMCL should be set aside and remanded to EPA for failure to protect sensitive sub-groups, as Congress intended.

EPA’s determination that dental fluorosis is not an adverse health effect of fluoride in drinking water for purposes of the RMCL represents a reversal of Agency policy established in 1975 and reaffirmed in 1981 and 1983. Not only did EPA fail to provide a reasoned analysis of why its prior policy of considering dental fluorosis to be an adverse health effect was no longer well-founded, but the Agency also failed to address the single most important piece of evidence in the record indicating that dental fluorosis is an adverse health effect of fluoride. Ignoring the conclusions of an objective panel of medical experts convened to consider the medical effects of exposure to fluoride in drinking water, the Agency instead relied exclusively upon the advice and opinions of parties who have been major activists on the promotion side of the national controversy over fluoridation of water supplies, despite obvious evidence of bias in their judgments. This Court should not uphold the Agency’s unexplained and unjustifiable reversal of policy as a reasonable exercise of discretion consistent with the preventive intent of the SDWA.

Finally, EPA’s imposition of a functional impairment test to define an adverse health effect of fluoride is not within the range of reasonable interpretations of the SDWA. The Agency made no claim in the rulemaking that it was changing its interpretation of the SDWA so as to require functional impairment as the definition of an adverse health effect of a contaminant — with the exception of fluoride. This interpretation is not only contrary to the clear preventive intent of Congress, but it is also inconsistent with every other statement EPA has ever made of its duties under the Act. These include the particular duty to err on the side of safety when there are conflicting opinions about the medical significance of an effect. The creation of a special definition of an adverse health effect just for fluoride is not entitled to deference by this Court.

The Agency’s treatment of evidence of other possible adverse health effects of fluoride was also tainted by the application of an erroneous evidentiary standard. Applying the unduly stringent functional impairment test and requiring a higher degree of proof than Congress intended, EPA failed to provide protection in the RMCL against a number of potential adverse health effects. Claiming erroneously that the SDWA doesn’t protect against “possible” adverse health effects, EPA also pointed to an allegedly large negative human data base to rebut all evidence of other potential adverse health effects. The Agency’s response ignores other record evidence that the human data base is not extensive, and that critical information is lacking, especially with respect to adverse skeletal and cardiovascular effects in children.

The Agency’s creation of a stringent and unprotective definition of the adverse health effects of fluoride, and its failure to rebut or demonstrate the invalidity of studies indicative of other potential adverse health effects of fluoride, violated the SDWA. The RMCL should be vacated and remanded to EPA for re-evaluation of the evidence consistent with the preventive intent of the Act.”