INGAA Petition for Reconsideration – National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines

       Pursuant to Clean Air Act (“CAA”) section 307(d)(7)(B), 42 U.S.C. § 7607(d)(7)(B), and for the reasons set forth below, the Interstate Natural Gas Association of America (“INGAA”)  petitions the Administrator of the United States Environmental Protection Agency (“EPA”) to reconsider specific provisions of its Final Rule in “National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines,” 75 Fed. Reg. 51570 (August 20, 2010).   INGAA is filing this petition to voice objections that could not have been raised during the public comment period because they concern Final Rule provisions that were not properly noticed in the proposed rule, 71 Fed. Reg. 9698 (March 5, 2009) (the “Proposed Rule”). The issues detailed below are of central relevance to the outcome of this rulemaking, and reconsideration should be granted to address them. Because we anticipate these issues will require further discussion of a technical in nature, we would welcome the opportunity to meet with EPA to discuss our concerns further.  In particular, the following issues warrant reconsideration:

            1.  Continuous Parameter Monitoring System (“CPMS”) Specifications:  Unlike the Proposed Rule, the Final Rule requires continuous parameter monitoring (“CPM”) for some classes of engines:

Owners and operators of existing 4SLB and 4SRB non-emergency stationary SI RICE that are greater than 500 HP, located at an area source of HAP, and operated more than 24 hours per calendar year must continuously monitor and record the inlet temperature of the oxidation catalyst or NSCR and also take monthly measurements of the pressure drop across the oxidation catalyst or NSCR. If an oxidation catalyst or NSCR is not being used on the engine, the owner or operator must continuously monitor and record the operating parameters (if any) approved by the Administrator.

Final Rule, 75 Fed. Reg. at 51574. Absent from this requirement are the technical specifications for operating and maintaining the required CPM systems. The Final Rule notes that these specifications are under development, id., yet without these specifications there is no meaningful way to assess and comment upon the feasibility or appropriateness of the Final Rule’s CPM requirements.

            Reconsideration is necessary to receive public comment and develop an administrative record on the technical specifications for the CPM systems contemplated in this docket. The topics to be addressed include data handling, validation and averaging requirements, and quality assurance /quality control standards (e.g., calibration requirements); as well as the requirement for a site-specific CPMS Monitoring Plan. Reconsideration is also necessary to determine whether the contemplated CPMS, as specified, are feasible and appropriate for the purposes identified in the Final Rule.

            Moreover, the need for reconsideration is urgent. The Final Rule includes new emission standards for existing engines, and those newly affected units have three years to comply. The new CPMS specifications, however, also apply to engines that require temperature monitoring and that are already subject to Subpart ZZZZ (i.e., engines subject to the original June 2004 rule or July 2008 amendments). Absent reconsideration, the new CPMS specifications for these engines would apply immediately, with no opportunity to comment.

            2.  Emission Standard for Four Stroke Lean Burn (“4SLB”) Engines: The Final Rule emission standard for 4SLB engines is based on new data that was not included in the Proposed Rule (although it was available from an earlier engine rulemaking) and EPA changed its process and analytical approach for determining the “floor” emission standard for Maximum Achievable Control Technology (“MACT”).

            The following changes occurred from the Proposed Rule:

·         EPA assessed “the best performing 12%” based on engines in its “population database” for the proposed rule and based on engines in its emissions database for the Final Rule (EPA uses engines larger than the size subcategory to define the floor);

·         EPA added a 2002 Test Report from “Thunder Creek Gas Services” that was in the original RICE NESHAP rulemaking into its emissions database for this rule (EPA also added some other engines and tests into its database). The Thunder Creek report includes seven 4SLB engines with an oxidation catalyst, including five identical Caterpillar engines with a rating of 586 hp. Four of these five engines serve as the sole basis for the emission standard because they are considered the “best performing 12%” of the 33 engines in the updated database. EPA acknowledged that these data were not included in the Proposed Rule.

·         EPA did not have data for 4SLB engines 500 hp or smaller. For the major source 4SLB subcategory from 100 to 500 hp, EPA believes that emissions data and the MACT floor determination based on engines from 500 hp to 1000 hp is appropriate for the 100 to 500 hp 4SLB subcategory.

·         To assess variability, EPA applied a statistical analysis based on the four Thunder Creek engine tests (a total of four data points). The analysis is analogous to that used for the 2009 Hospital Waste Incinerator/Medical Incinerator standard where the “upper prediction limit” based on the “student t-test” was used (i.e., EPA essentially had an Excel calculation available from that recent rule and used it for this rule).  This approach was not included or discussed in the Proposed Rule.

            In the preamble to the Final Rule, EPA acknowledged that data were inadvertently omitted from the MACT floor analysis for the Proposed Rule, but were nevertheless incorporated into the analysis for the Final Rule. See 75 Fed. Reg. at 51579. INGAA appreciates that after EPA published the Proposed Rule, it invited the public to supplement the emission database with additional test data. That said, an invitation to provide supplemental data is not a substitute for the public’s right to comment on the methodology EPA applied to the expanded database to derive the MACT floor and other emission standards for 4SLB engines.

            Referring to the 4SLB database, the Final Rule observes that “Stakeholders who believe that further review of this information is in order or necessary can petition for reconsideration of this final rule.” 75 Fed. Reg. at 51579. INGAA believes that further review of this information is in order and accordingly seeks reconsideration.