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New and Revised Emissions Factors for Flares and Other Refinery Process Units and Determination for No Changes to VOC Emissions Factors for Tanks and Wastewater Treatment Systems

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Environmental Protection Agency (EPA).


Notice of final action.


On April 20, 2015, the Environmental Protection Agency (EPA) issued new and revised emission factors for flares and other refinery process units and issued its final determination that revisions to existing emissions factors for tanks and wastewater treatment systems are not necessary. The EPA finalized these actions in compliance with a consent decree entered into with Air Alliance Houston, Community In-Power and Development Association, Inc., Louisiana Bucket Brigade and Texas Environmental Justice Advocacy Services (“Plaintiffs”).


You may review copies of the final actions taken and the supporting information electronically at:​ttn/​chief/​consentdecree/​index_​consent_​decree.html.

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Ms. Gerri Garwood, Measurement Policy Group (MPG), Sector Policies and Programs Division (D243-05), Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, telephone number: (919) 541-2406; fax number: (919) 541-1039; and email address:

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As described above, the EPA finalized these actions to fulfill its obligations under the consent decree, which resolves litigation in which Plaintiffs alleged that the EPA failed to perform nondiscretionary duties pursuant to Clean Air Act (CAA) section 130 to review, and, if necessary, revise the emissions factors for volatile organic compounds (VOC) for flares, liquid storage tanks (“tanks”), and wastewater collection, treatment and storage systems (“wastewater treatment systems”) at least once every 3 years. See Air Alliance Houston, et al. v. McCarthy, No. 1:13-cv-00621-KBJ (D.D.C.).

The EPA evaluated all of the data collected during the 2011 Refinery Information Collection Request (2011 Refinery ICR), the data referenced in the Complaint, other test data available to the agency for flares, tanks and wastewater treatment systems, and data submitted during the public comment period. Based on this evaluation, we finalized a new VOC emissions factor for flares. We also issued final emissions factors (or emissions estimation methodologies) for certain refinery operations and pollutants that are not covered by the consent decree. The other emissions factors include carbon monoxide (CO) for flares; oxides of nitrogen (NOX), total hydrocarbons (THC), and CO for sulfur recovery units; THC for catalytic reforming units; NOX for hydrogen plants; and hydrogen cyanide for fluid catalytic cracking units. We updated Sections 5.1, 8.13, and 13.5 of AP-42, Compilation of Air Pollutant Emission Factors, to incorporate the new and revised emissions factors. AP-42 is the primary compilation of EPA's emission factor information.

We previously developed a refinery emissions estimation protocol in response to a Data Quality Act petition which was used in the 2011 Refinery ICR. The refinery emissions estimation protocol lists and ranks available methods for calculating emissions from refineries. We finalized revisions to the Refinery Protocol, with some changes to address specific comments. Specifically, we updated Sections 1, 5, and 6 of the refinery emissions estimation protocol with these new emission factors. However, we are not requiring the use of the Refinery Protocol, just as we do not require the use of AP-42. It is simply another tool for use in estimating emissions when site-specific test data do not exist or are not available. We consider the Refinery Protocol to provide site-specific emissions inventory guidance that will result in more accurate and complete emissions inventories.

Based on our review of the available emissions data for tanks and wastewater treatment systems, we found that the data reviewed generally showed similar results between measured data and the existing emissions estimation methods. Therefore, we issued a final determination that revisions of the VOC emissions factors for tanks and wastewater treatment systems are not necessary.

Additionally, while we proposed a revised NOX emissions factor for flares, based on our review of available data and additional information received after proposal, we determined that the data was not adequate to support revising the NOX emissions factor for flares. Based on comments received, the EPA determined that the NOX data used for the proposal contained certain flaws that rendered the data quality suspect.

Per the requirements of the consent decree, these final actions were issued on April 20, 2015. To support these findings, we developed two reports: “EPA Review of Available Documents and Rationale in Support of Final Emissions Factors and Negative Determinations for Flares, Tanks, and Wastewater Treatment Systems,” and “Review of Emissions Test Reports for Emissions Factors Development for Flares and Certain Refinery Operations.” We also prepared the following report to respond to the comments received during the public comment period: “Background Information for Final Emissions Factors Development for Flares and Certain Refinery Operations and Final Determination for No Changes to VOC Emissions Factors for Tanks and Wastewater Treatment Systems, Summary of Public Comments and Responses.” These reports, along with links to the updated chapters in AP-42 and the Refinery Protocol, were posted Start Printed Page 26926on the Web site listed in the ADDRESSES section of this document on April 20, 2015.

These actions constitute final agency action of national applicability for purposes of section 307(b)(1) of the CAA. Pursuant to CAA section 307(b)(1), judicial review of these final agency actions may be sought only in the United States Court of Appeals for the District of Columbia Circuit. Petitions for review must be filed by July 10, 2015. Judicial review of these final agency actions may not be obtained in subsequent proceedings, pursuant to CAA section 307(b)(2). These actions are not a rulemaking and are not subject to the various statutory and other provisions applicable to a rulemaking.

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Dated: May 1, 2015.

Stephen D. Page,


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[FR Doc. 2015-11344 Filed 5-8-15; 8:45 am]