Daily Rules, Proposed Rules, and Notices of the Federal Government
The information in this Supplementary Information section of this preamble is organized as follows:
Entities affected by this rule include sources in all industry groups. The majority of sources potentially affected are expected to be in the following groups that emit PM:
Entities affected by this rule also include state, local and tribal reviewing authorities responsible for implementing Clean Air Act (CAA or Act) stationary source permitting programs.
In addition to being available in the docket, an electronic copy of this final rule will also be available on the World Wide Web. Following signature by the EPA Administrator, a copy of this final rule will be posted in the regulations and standards section of our NSR home page located at
The purpose of this rulemaking is to revise the definition of “regulated NSR pollutant” to correct an inadvertent error contained in the regulations for PSD at 40 CFR 51.166 and 52.21, and in the EPA's Emission Offset Interpretative Ruling at 40 CFR part 51 Appendix S. This error was introduced in the revised definition of “regulated NSR pollutant” in the 2008 rule titled, “Implementation of the New Source Review (NSR) Program for Particulate Matter Less Than 2.5 Micrometers (PM
This final action ensures that our originally-intended approach for regulating the three indicators for emissions of particulate matter under the PSD program is codified. Thus, “PM
Sections 108 and 109 of the CAA govern the establishment and revision of the NAAQS. Section 108 directs the Administrator to identify and list each air pollutant that “in his judgment, cause[s] or contribute[s] to air pollution which may reasonably be anticipated to endanger public health and welfare” and “the presence of which in the ambient air results from numerous or diverse mobile or stationary sources” and to issue air quality criteria for those pollutants that are listed. CAA section 108(a)(1)(A), (B). Section 109 directs the Administrator to propose and promulgate primary and secondary NAAQS for pollutants listed under section 108 to protect public health and welfare, respectively. Section 109 also requires review of the NAAQS at 5-year intervals.
“Particulate matter” is a term used to define an air pollutant that consists of a mixture of solid particles and liquid droplets found in the ambient air. Particulate matter occurs in many sizes and shapes and can be made up of hundreds of different chemicals. As explained further in the discussion that follows, the EPA has regulated several size ranges of particles under the CAA, referred to as indicators of particles, which has required that test methods be developed to measure the appropriate size particles that occur in the ambient air or that are being emitted directly from a source. In some cases, the EPA regulates certain species of particles as separate “air pollutants.” For example, lead, beryllium, fluorides and sulfuric acid mist are constituents of particulate matter that are also regulated separately under New Source Performance Standards (40 CFR part 60) and/or National Emissions Standards for Hazardous Air Pollutants (40 CFR parts 61, 63 or 65).
Particles as measured in the ambient air consist of both primary and secondary particles. Primary particles are emitted directly from sources, and may include gaseous emissions, which, when emitted from the stack of a source, condense under ambient conditions to form particles. Primary particles directly emitted by a source as a solid or liquid at the stack and captured on the filter of a test train are referred to as the “filterable” PM fraction. The gaseous emissions that form particles upon condensing under ambient conditions soon after release from the stack are referred to as “condensable PM.” Other types of particles, known as secondary particles, are formed from precursors, such as SO
Initially, the EPA established NAAQS for PM on April 30, 1971, under sections 108 and 109 of the Act.
On July 18, 1997, the EPA made significant revisions to the PM NAAQS in several respects. While the EPA determined that the PM NAAQS should continue to focus on particles less than or equal to 10 µm in diameter, the EPA also determined that the fine and coarse fractions of PM
In the next periodic review, the EPA concluded, on October 17, 2006, that it was necessary to revise the primary and secondary NAAQS for PM to provide increased protection of public health and welfare.
Section 110 of the Act requires that state and local air pollution control agencies develop and submit plans, known as state implementation plans or SIPs (that provide for the attainment, maintenance and enforcement of the NAAQS), for approval by the EPA. An essential component of each SIP is the emissions reduction strategy, including emissions limitations and other control measures (as set forth in SIPs and in individual source permits) designed to control the emissions of pollutants that contribute to the air quality against which the NAAQS are measured. For many years, most control measures for PM were generally focused on primary PM—specifically, the filterable PM fraction. Accordingly, the early EPA test methods for quantifying amounts of PM emitted by sources generally were based on the collection of the filterable PM fraction.
In support of state obligations to develop emissions reduction strategies, section 111 of the Act requires the EPA to adopt standards of performance that focus on sources that cause or contribute significantly to “air pollution which may reasonably be anticipated to endanger public health and welfare.” Such standards, referred to as NSPS, are emissions standards that are intended to reflect the degree of air pollution emission limitation attainable through the application of the best system of emission reduction (taking into account the cost of achieving such reduction and any non-air quality health and energy requirements) that the Administrator determines has been adequately demonstrated. Accordingly, the EPA historically has developed NSPS (and corresponding compliance test methods) under 40 CFR part 60 to provide standards of performance that address, among other pollutants, the control of PM.
When the EPA promulgated the first set of NSPS for PM in 1971, only the filterable PM fraction was regulated. The EPA simultaneously promulgated a test method, known as Method 5, as the NSPS compliance test method to measure the filterable fraction of PM. Once available, Method 5 was often also used for permitting purposes to quantify the in-stack emissions of PM that represented the particles in the atmosphere expressed in terms of the ambient indicator, TSP—the original indicator for the PM NAAQS. Thus, the filterable PM collected by Method 5 or other similar source test methods was sometimes referred to as “TSP emissions,” even though it was recognized that Method 5 actually collected particles that exceeded the TSP size range (25-45 µm), and did not include the condensable PM fraction. Today, Method 5 continues to serve as the performance testing procedure for most NSPS for PM.
As a result of the promulgation of the PM
Even before the EPA introduced the PM
In 2002, the EPA issued a rule known as the Consolidated Emissions Reporting Rule (CERR), which, among other things, established requirements for the reporting to the EPA of PM
In November 2005, the EPA proposed requirements that states must fulfill in developing their implementation plans for the attainment of PM
On March 25, 2009, the EPA proposed to modify existing Method 201A to allow for measurement of filterable PM
The NSR program is a statutorily-based preconstruction permitting program that applies when a stationary source of air pollution proposes to construct or undergo modification. The NSR program consists of three different preconstruction permit programs: PSD, nonattainment NSR and minor NSR. We often refer to the PSD and nonattainment NSR programs together as the major NSR program because those permit programs regulate the construction of new major stationary sources and major modifications to existing major stationary sources.
The nonattainment NSR program applies in advance of construction to new major stationary sources and major modifications of sources of a pollutant that locate in an area that is designated “nonattainment” for that pollutant. As such, the nonattainment NSR program applies only with respect to pollutants for which the EPA has promulgated NAAQS (commonly described as “criteria pollutants”). On the other hand, the PSD program is a statutorily-based preconstruction review and permitting program that applies to new or modified major stationary sources proposing to locate in an area meeting any NAAQS (“attainment” areas) and areas for which there is insufficient information to classify them as either attainment or nonattainment (“unclassifiable” areas) for at least one pollutant. Like the nonattainment NSR program, the applicability of the PSD program to a major stationary source or major modification must be determined in advance of construction and is on a pollutant-specific basis. However, unlike the nonattainment NSR program, the PSD requirements may apply to any “air pollutant” that is “subject to regulation” under the Act.
Consistent with the original NAAQS and PSD increments for PM, the PSD program established pollutant applicability requirements for PM on the basis of the TSP indicator. Accordingly, the PSD regulations defined a “significant” increase in emissions of PM as 25 tons per year (tpy). When the EPA revised the PM NAAQS in 1987, establishing a new PM
In 1993, as authorized by the CAA Amendments of 1990, the EPA adopted increments for PM that were expressed in terms of ambient concentrations of PM
In October 1997, following the promulgation of revised NAAQS for PM, which included the addition of NAAQS defined by the PM
In 2008, the EPA issued a final rule setting forth certain new requirements for PM
Hence, PM is currently being regulated under the PSD program as three separate regulated pollutants. Those include PM
The 2008 rule also added a provision to the definition of “regulated NSR pollutant” in the PSD regulations and the Emission Offset Interpretative Ruling that required the inclusion of the condensable PM fraction for all three emissions-based indicators of PM. Accordingly, the determination of the potential emissions (for permit applicability determinations), and the setting of emissions limitations and in-stack pollutant measurements (for source compliance purposes) would involve the inclusion of the condensable fraction of PM for each of the three PM indicators. However, the EPA also announced in the 2008 rule that it would not require states to implement the requirement to account for condensable PM in establishing enforceable emissions limits for either PM
This final rule corrects an inadvertent error that established a general requirement under the definition of “regulated NSR pollutant” to account for the condensable PM fraction in applicability determinations and in establishing emissions limitations with regard to “particulate matter emissions.” The change that has been made affects three sets of NSR regulations, including the PSD regulations at 40 CFR 51.166 and 52.21, and the Emission Offset Interpretative Ruling at 40 CFR part 51 Appendix S.
It is important to note that the change being finalized under this action does not mean that we are totally exempting the inclusion of the condensable PM fraction as part of “particulate matter emissions.” As we described in the proposal, it may be necessary for PSD sources to count the condensable PM fraction with regard to “particulate matter emissions” in certain cases. The first case is for a source that is subject to an NSPS for which the condensable PM fraction must be included in the determination of compliance with the standard of performance for PM.
In this final rule, based on public comments and additional considerations we have since identified, we are not adopting the proposed clarifying text in 40 CFR 51.166(b)(49)(ii) and 52.21(b)(50)(ii). In the proposal, the EPA explained that the revisions to these subsections were intended to assure that the condensable PM fraction of “particulate matter emissions” was counted in those cases where either the applicable NSPS requires that the condensable PM fraction be included in the determination of compliance with the standard of performance for PM or the applicable SIP already requires the inclusion of the condensable PM fraction. The EPA does not believe that the proposed revisions to subparagraph (ii) are necessary to include the condensable fraction of “particulate matter emissions” where it would be consistent with the applicable NSPS. Federal regulations at 40 CFR 51.100(pp) already define “particulate matter emissions” to be measured according to “the applicable reference methods, or an equivalent or alternative method, specified in this chapter, or by a test method specified in an approved State implementation plan.” We believe that definition is appropriately applied under both part 51 and part 52 of our regulations, even though part 52 does not presently contain such any definition of the term “particulate matter emissions,” and thus is not directly applicable. Thus, the condensable fraction of particulate matter emissions should be counted where appropriate, consistent with the part 51 definition.
In addition, public comments discussed later in this preamble raised questions about the proposed regulatory language that provided the option, when an NSPS was not applicable to a source, for a reviewing authority to determine on a case-by-case basis whether to include condensables in “particular matter emissions.” Comments have persuaded the EPA that this case-by-case approach is not needed and that if a source is not covered by an NSPS, the condensable PM fraction need not be included in “particulate matter emission” unless the state elects to implement such a requirement through its SIP.
Furthermore, we have recognized that the regulatory text that we proposed (which is not specific to “particulate matter emissions”) may have a broader effect on the definition and measurement of other regulated NSR pollutants that extends beyond the intentions outlined in the proposal. Accordingly, in order to allow for further evaluation of the possible implications of the proposed regulatory text, the EPA is not finalizing the proposed revisions to subparagraph (ii) at this point.
For these reasons, we are retaining the existing regulatory language in these subparts of the PSD regulations without change. However, we will continue to evaluate the need for the proposed changes to 40 CFR 51.166(b)(49)(ii) and 52.21(b)(50)(ii).
The proposed revisions to these paragraphs of the regulations were a secondary component of the proposed rule. The primary objective of our decision to revise the definition of “regulated NSR pollutant” is to correct an inadvertent error, and thus ensuring that we do not impose a new requirement on state/local agencies and the regulated community that has little if any effect on preventing significant air quality deterioration or on efforts to attain the primary and secondary PM NAAQS. That is, the PSD regulations will not require the inclusion of condensable PM in measurements of “particulate matter emissions,” except where either the applicable NSPS compliance test includes the condensable PM fraction or the applicable implementation plan requires the condensable PM fraction to be counted. Proposed new or modified stationary sources of PM typically will be subjected to the PSD requirements on the basis of their potential to emit significant amounts of PM
The EPA provided a 60-day review and comment period on this rulemaking, which closed on May 15, 2012. A total of seven comment letters (six industry comment letters and one state agency comment letter) were received on the proposed amendment to correct the definition of “regulated NSR pollutant” by removing the unilateral requirement that condensable PM be
To address “particulate matter emissions,” we generally agree with the commenter's understanding that one of the primary concerns under the PSD program is to ensure that a new major stationary source that emits significant amounts of “particulate matter emissions” or a major modification that results in a significant net emissions increase of “particulate matter emissions” must undergo a control technology review for that emissions indicator of PM. However, there is a source impact assessment component in the PSD requirements that cannot simply be relegated to a minor NSR review requirement with regard to “particulate matter emissions.” While there are no air quality standards (NAAQS or increments) associated with “particulate matter emissions,” section 165(e)(3)(B) of the CAA requires an analysis of the ambient air quality, climate, meteorology, terrain, soils and vegetation, and visibility “for each pollutant regulated under this Act” that will be emitted by the proposed PSD project. This requirement, referred to as the “Additional Impact Analysis” at 40 CFR 51.166(o) and 40 CFR 52.21(o), could potentially require certain analyses with regard to “particulate matter emissions” as part of the PSD preconstruction review process.
On the other hand, SIPs, including the NSR permitting requirements, approved under section 110 of the Act, must provide for the attainment and maintenance of NAAQS designed to protect public health and welfare. If the enforceable limits in a PSD permit for PM
Thus, the final rule retains the general requirement to include the condensable fraction of PM
In the preamble to the notice of proposed rulemaking (NPRM), we indicated that when a proposed source or modification emits a pollutant that is regulated under section 111 of the CAA, but the source itself is not subject to an NSPS for that pollutant, the reviewing authority will determine the applicable test method to be used to determine the source's compliance,