Summary of Argument:
An agency must provide a reasoned explanation when promulgating or amending a rule. An agency’s implausible explanation or its failure to consider relevant and significant aspects of a problem renders a rulemaking arbitrary and capricious. Because the EPA and Corps refused to consider the scientific basis of the Clean Water Rule, including the most current scientific understanding of how streams and wetlands contribute to the chemical, physical, and biological integrity of downstream waters, the Suspension Rule is arbitrary and capricious. More broadly, all major EPA policy decisions since the agency’s inception have required the use of science. Science is critically important to furthering the goals of the CWA, and this Court should hold the EPA and Corps accountable for failing to consider science in their decisions. The agencies cannot so blithely disregard science related to the chemical, physical, and biological integrity of the Nation’s aquatic resources. Continue reading.