PADEP Drafts Proposed Fine Particulate NSR Rule

June 15, 2009
by BART CASSIDY
MGKF News Flash

As required by the Federal Clean Air Act, the Pennsylvania Department of Environmental Protection ("PADEP") has prepared draft amendments to its state-specific regulations for New Source Review in nonattainment areas ("NSR-NA"). The draft revisions are intended to extend Pennsylvania's existing NSR-NA regulations to fine particulate matter, defined as particulate matter with a diameter of less than 2.5 microns ("PM2.5").

In many significant respects, the draft NSR amendments track the federal NSR rule for PM2.5. Specifically, the draft Pennsylvania regulation would not require inclusion of condensable particulate matter in the calculation of PM2.5 until January 1, 2011, unless EPA completes rulemaking establishing an earlier date. In addition, consistent with the presumptions included in the federal standards, the draft Pennsylvania regulation would include oxides of nitrogen ("NOx") among the precursors to PM2.5 formation, while excluding volatile organic compounds ("VOCs") and ammonia.

At the same time, PADEP has proposed to incorporate into the PM2.5 NSR provisions certain unique requirements from the Pennsylvania NSR-NA program that are inconsistent with the federal rule, and which would render the NSR-NA program far more stringent in Pennsylvania. Specifically, PADEP's draft PM2.5 NSR amendments would impose the "de minimis aggregation" provision of Pennsylvania's NSR-NA rule on PM2.5 emissions. These provisions of PADEP's existing regulations require facilities to aggregate emission increases of the relevant pollutant that are less than the NSR significance threshold, over a ten year period. To the extent that this aggregation of emissions exceeds the significance threshold for major modifications, then the source operator must secure emission reduction credits to offset the aggregate emission increases. Since the significant net emission increase level for major modifications of PM2.5 is only ten tons per year, aggregation of de minimis increases over a ten year period would cause many facilities to trigger NSR-NA for PM2.5.

The de minimis aggregation provisions of Pennsylvania's rule are an artifact of the original proposed federal NSR requirements for ozone. EPA did not preserve these provisions in the final federal NSR rule, but PADEP applied this requirement in Pennsylvania. EPA has not even suggested the potential for de minimis aggregation under the PM2.5 NSR rule, but PADEP has nonetheless proposed to extend its unique approach to this pollutant as well.

PADEP has transmitted the draft PM2.5 NSR rule to the Air Quality Technical Advisory Committee for review and comment, and thereafter will transmit a proposed rule to the Environmental Quality Board for review and publication. Following approval by the EQB, the proposed rule will be published for public comment.