By Megan J. Spencer

On October 25, 2012 the Environmental Protection Agency (EPA) published its corrected definition of “regulated NSR pollutant.” The Louisiana Department of Environmental Quality (LDEQ) adopted EPA’s revised definition of “regulated new source review (NSR) pollutant” at LAC 33:III.509.B in a May 20, 2013 Louisiana Register Notice. 39 La. Reg. 1280 (May 20, 2013). LDEQ’s definition of “regulated NSR pollutant” is now consistent with the corrected federal definition found at 40 C.F.R. § 51.166(b)(49). The revision to the federal and state rule “removes a general requirement in the definition of ‘regulated NSR pollutant’ to include condensable PM when measuring one of the emissions-related indicators for particulate matter (PM) known as ‘particulate matter emissions’ in the context of the PSD and NSR regulations.” 77 Fed. Reg. 65107 (Oct. 25, 2012). The revised definition of “regulated NSR pollutant” states:

PM2.5 emissions and PM10 emissions shall include gaseous emissions from a source or activity which condense to form particulate matter at ambient temperatures. On or after January 1, 2011, such condensable particulate matter shall be accounted for in applicability determinations and in establishing emissions limitations for PM2.5 and PM10 in PSD permits. Compliance with emissions limitations for PM2.5 and PM10 issued prior to this date shall not be based on condensable particulate matter. Applicability determinations made prior to this date without accounting for condensable particulate matter shall not be considered in violation of this Section.

LAC 33:III.509.B. Thus, the rule removes the unintended new requirement on state and local agencies and the regulated community to include condensable PM fractions in the measurement of “particulate matter emissions.”

The rule, however, preserves the requirement to include condensable PM measurements for “particulate matter emissions” where required by other regulations. EPA provided three cases where it may be necessary for sources to count condensable PM fraction for “particulate matter emissions:”

  1. Sources subject to New Source Performance Standard (NSPS) for which condensable PM fraction must be included in the determination of compliance with the standard of performance for PM (see, e.g. 40 C.F.R. § 60.50Da);
  2. Sources where the applicable State Implementation Plan (SIP) already requires the condensable fraction to be included in the measurement of “particulate matter emission;” and
  3. Sources required by the reviewing authority to include condensable PM fractions in the measurement of “particulate matter emission.”

Additionally, measurement of condensable PM continues to be required in all cases for emissions of PM10 and PM2.5. Thus, PM is currently regulated under the Prevention of Significant Deterioration (PSD) program as three separate regulated pollutants: (1) PM10; (2) PM2.5; and (3) particulate matter emissions. Proposed new and modified sources must treat each indicator of PM as a separate regulated pollutant and must consider when measurements of condensable PM are required.

Perhaps the greatest benefit of this rule change will be to permittees whose emission limits were written prior to widespread consideration and measurement of condensable PM. Many facilities found themselves in the position of having to count condensable PM against a limit that had been set only for filterable PM, but this change will provide relief from what may have otherwise been permit violations. The rule should serve as a reminder to those same permittees and permit applicants that condensable PM must be considered in setting emission limits in future permits or renewals.