In a recent case involving environmental policies, the U.S. Court of Appeals for the D.C. Circuit continued on its course of remanding administrative agency actions while neither reversing nor vacating them, in order to allow bureaucrats to explain decisions that otherwise cannot be sustained. This practice is unfortunate. It contravenes due process requirements that agency choices be evaluated on the actual record generated below instead of post-hoc litigation rationalizations and is based on a dubious extrapolation of precedent.

The D.C. Circuit, which is responsible for most of the judicial review of federal regulations, used the remand-only route in a March 1999 decision, Sierra Club v. EPA.¹ The Sierra Club case arose from the 1990 Amendments to the Clean Air Act (CAA).² The 1990 Amendments had directed the U.S. Environmental Protection Agency (EPA) to set emissions limitations for medical waste incinerators (MWIs).³ EPA was to have balanced the benefits of maximum reduction of air pollutant emissions with the costs of achieving the reduction, along with other health, environmental, and energy factors.⁴ The statute set minimum stringency (or maximum emissions) levels, but authorized EPA to exceed such levels if they were "achievable."⁵ The Sierra Club and the Natural Resources Defense Council challenged the ensuing EPA rulemaking.⁶