EPA Appears to Take Different Approach Toward Setting MACT Standards

March 18, 2009
MGKF News Flash

EPA appears to have adopted a more stringent posture for establishing hazardous air pollutant ("HAP") emission standards under a recent proposed rule. In particular, EPA has used very conservative methods in determining maximum achievable control technology ("MACT") standards within the proposed revision to the New Source Performance Standards ("NSPS") and emission guidelines for medical waste incinerators, 40 C.F.R. Part 60, Subparts Ce and Ec (the "MWI MACT").

EPA had originally promulgated the MWI MACT in 1997. Certain environmental interests appealed the MWI MACT on multiple grounds, generally contending that EPA had inappropriately established MACT standards that did not reflect an adequate degree of stringency. The Court rejected many of the environmentalists' challenges, but nonetheless remanded (without vacatur) the MWI MACT to EPA for additional rulemaking, on narrow grounds. In 2007, EPA proposed to promulgate a revised version of the MWI MACT. That proposed rule did not substantially affect the substantive emission and operating standards under the regulation. However, on December 1, 2008, EPA published a revised version of the proposed rule, dramatically decreasing the proposed emission standards for the MWI category.

The preamble to the December, 2008 proposed rule reflects EPA's determination to adopt a very conservative approach toward evaluating MACT, largely in response to several determinations by the D.C. Circuit Court of Appeals in response to challenges to other MACT standards. Most notably, the Court sharply rebuked EPA in vacating MACT standards for industrial and commercial boilers, formerly promulgated at 40 C.F.R. Part 63, Subpart DDDDD (the "Boiler MACT") and manufacturers of bricks and structured clay products, formerly promulgated at 40 C.F.R. Part 63, Subpart JJJJJ (the "Brick MACT"). The Court's decisions regarding the Boiler MACT and Brick MACT criticized EPA for allowing operational and economic considerations to influence EPA's determination of MACT standards. In addition, the Court held that EPA may not allow certain otherwise affected sources to avoid MACT standards, nor establish HAP emission controls based upon "best practices" rather than specific emissions standards.

In response to the Court's rejections of EPA's attempts to establish MACT requirements that reflect practical considerations, EPA appears to have reverted within the proposed MWI MACT to a very conservative, and potentially impractical, methodology for determining MACT. Not only would promulgation of this approach severely burden the medical waste incinerator industry, it may also reflect a much more stringent EPA approach toward MACT regulation in general.