March 16, 2021

Michael S. Regan, Administrator
Office of the Administrator (1101A)
United States Environmental Protection Agency
William Jefferson Clinton Building
1200 Pennsylvania Avenue, N.W.
Washington, DC 20460

Re: Regional Haze Guidance Petition for Reconsideration: Priority Issues

Dear Administrator Regan:

National Parks Conservation Association, Sierra Club, the Coalition to Protect America’s National Parks, Appalachian Mountain Club, and Earthjustice hereby  follow up on our pending Petition for Reconsideration of Guidance on Regional Haze State Implementation Plans for the Second Implementation Period, filed with EPA on May 8, 2020. The Petition for Reconsideration asks the Administrator of the United States Environmental Protection Agency (“EPA”) to reconsider the “Guidance on Regional Haze State Implementation Plans for the Second Implementation Period” dated August 20, 2019 (“Final Guidance”) and replace it with guidance that comports with the Clean Air Act (“Act”) and the Regional Haze Rule to help states in making progress towards natural visibility conditions at all Class I areas142 U.S.C. §§ 7491, 7492.. Because the Final Guidance was a significant departure from the Draft Guidance2Draft Guidance on Progress Tracking Metrics, Long-term strategies, Reasonable Progress Goals and Other Requirements for Regional Haze State Implementation Plans for the Second Implementation Period (“Draft Guidance”), 81 Fed. Reg. 44,608 (July 8, 2016). issued in 2016 for the second planning period and contains provisions at odds with the Act and Regional Haze Rule, we requested that EPA revise the Final Guidance to comply with applicable statutes and regulations.

Our Petition for Reconsideration described in detail the basis for this requested action, and provided a summary of issues and applicable statutes and regulations (at 2-4). While we continue to urge EPA to act on all issues identified in the Petition for Reconsideration, we write to highlight several issues requiring EPA’s immediate attention and action as many states are in the midst of developing their second planning period haze plans to be submitted to EPA by July 2021.

Under Executive Order 12,998, Federal agencies must make achieving environmental justice part of their mission; under Executive Order 13,990, agencies must advance and prioritize environmental justice. The Act’s regional haze provisions regarding reasonable progress and best available retrofit technology require EPA to consider nonair quality environmental impacts. 42 U.S.C. § 7491(g)(1)-(2). Thus, EPA’s actions on regional haze must address environmental justice concerns, both for sources located in disproportionately impacted communities, and regarding impacts further downwind. Implementing the regional haze program consistent with the principles described in this letter will reduce pollution and offer public health benefits to environmental justice areas.

We commend to EPA’s attention the work of the Oregon Department of Environmental Quality (“ODEQ”) to consider pollution burden and population characteristics to develop environmental justice criteria, and to understand the potential co-benefits of reasonable progress measures in the state’s haze planning process. Consistent with President Biden’s Executive Order, EPA should encourage states to explicitly consider the environmental justice impacts and potential co-benefits of pollution controls in their state regional haze plans for the second planning period.

1. The Uniform Rate of Progress is not an off-ramp for reasonable progress requirements.

Under the Regional Haze Rule, state haze plans must determine the uniform rate of
visibility improvement needed to attain natural visibility conditions by 2064.340 C.F.R. § 51.308(f)(1)(vi)(A). However, meeting or exceeding this uniform rate of progress, also known as the “glidepath,” does not obviate the need for states to consider sources for reductions in visibility impairing emissions as part of their reasonable progress obligations under the Act.442 U.S.C. § 7491(b)(2). Any state attempts to minimize reasonable progress obligations are contrary to programmatic requirements and EPA’s statement that states must “determine what emission limitations, compliance schedules and other measures are necessary to make reasonable progress by considering the four factors” and must not reject “control measures . . . determined to be reasonable” based on the degree of progress.582 Fed. Reg. 3078, 3093 (Jan. 10, 2017). See Petition for Reconsideration at 10-11.

2. Screening thresholds must bring in most sources of visibility-impairing pollution.

States must identify sources for the four-factor analysis; any screening threshold a state applies must ensure that the threshold is low enough to bring in most sources harming a Class I area and must not simply eliminate evaluations of all or most sources for measures to reduce visibility impairing pollution. However, EPA’s Final Guidance (at 19) allows states complete discretion in setting a threshold. This discretion allows sources to be excluded from the analysis and application of emission reduction meansures needed to protect Class I areas.

Instead, EPA should instruct states to ensure that their source selection represents a significant percentage of the state’s visibility impairing emissions. Any threshold established must be set low enough to bring in most sources that emit haze causing pollution. Where a state relies on modeling to set any screening thresholds or select sources to evaluate for reasonable progress, the state must ensure that the sources’ potential emissions were modeled, all visibility impairing pollutants were modeled for each source, all units were modeled for all sources, and sources were modeled for impacts on the twenty percent worst days. For any sources that exceed thresholds but are not subject to emission reduction requirements, states should provide a thorough four-factor analysis of controls or provide justification as to why a four-factor analysis would not likely lead to a determination that additional measures are needed to make reasonable progress.

3.  States must not use visibility as a “fifth factor” when evaluating reasonable progress.

The Act provides that: in determining reasonable progress there shall be taken into consideration the costs of compliance, the time necessary for compliance, and the energy and nonair quality environmental impacts of compliance, and the remaining useful life of any existing source subject to such requirements.

42 U.S.C. § 7491(g)(1). While visibility is the goal of the regional haze program, id. at 7491(a)(1), the four-factor reasonable progress evaluation does not itself incorporate visibility. EPA must affirm this fundamental principle, as instead incorporating a visibility criteria metric into the four-factor test misconstrues the statutory approach. That is, states may consider visibility, but it is not a fifth factor and cannot be used as a basis for rejecting a control.

As EPA made clear in its Draft Guidance, states should follow one of two approaches to the consideration of visibility in any reasonable progress analysis. First, states could simply consider the available control measures for all sources. For each source or source category, states would adopt those measures that are deemed reasonable after considering the four statutory factors, and would not use visibility as screening metric. This approach is clearly permissible under the plain language of the Act quoted above. Under this first approach, for each source, group of sources, or source category, a state should include in its reasonable progress plan the most effective measures that are reasonable to require in light of the four factors alone. A state following this recommended approach may reject a control measure only when one of the four statutory factors, or some combination of the four factors (e.g., cost-effectiveness) is not satisfied. That is, the state should select the most effective emission reduction measure for each source that satisfies the four factor considerations.

Alternatively, states may consider visibility at the screening level to identify the sources or source categories that will be subject to a four-factor analysis.6If a state uses the emissions/distance (Q/d) metric or related tool for initial source selection for four-factor analysis, it should require a lower Q/d threshold in the second planning period than in the first period to address more sources, including sources that are lower emitting and sources that are further in distance than the sources addressed in the first implementation period. After that screening step, states may consider only the four statutory factors to determine whether emission reduction measures are necessary to achieve reasonable progress. More specifically, states may not assess visibility impacts or benefits and weigh them against the four statutory factors to select an appropriate reasonable progress measures. Had Congress wished for states to consider visibility in determining reasonable progress requirements, it would have built the provision into the statute as it did with best available retrofit technology (“BART”). Regional haze is “visibility impairment that is caused by the emission of air pollutants from numerous anthropogenic sources located over a wide geographic area.” 40 C.F.R. § 51.301. At any given Class I area, hundreds or even thousands of individual sources may contribute to regional haze. Thus, it is not appropriate to reject a control measure for a single emission unit, a single source, or even a group of sources on the basis of the associated visibility benefits.

5. States cannot circumvent a four-factor analysis for sources that intend to retire.

EPA has long required that any consideration of plant retirement in the four-factor analysis must be supported by enforceable retirement commitments, consistent with the “remaining useful life” criterion of the Act and the Regional Haze Rule.742 U.S.C. § 7491(g)(1); 40 C.F.R. § 51.308(d)(1)(i)(A). EPA defines a source’s “remaining useful life” as the difference between the date that controls would be installed and “the date the facility permanently stops operations.”840 C.F.R. pt. 51, App. Y § (IV)(D)(4)(k)(2)(2). If the remaining useful life affects the selection of controls, “this date should be assured by a federally- or State-enforceable restriction preventing further operation.”9Id. If a potential retirement is not federally enforceable, it cannot be relied upon to shorten the remaining useful life of a source. Instead, the Final Guidance (at 20) hedges this requirement, allowing for retirements delayed even beyond 2028 to provide an off-ramp for source selection. This is a departure from EPA’s long-standing requirement in the regional haze program and is in conflict with basic requirements of the Regional Haze Rule. A source that retires by December 31, 2028 (or later) has at least eight years of potential emission reductions. Even considering this shortened remaining useful life, cost-effective controls, which sources can often install in months, can frequently be justified. For instance, a source could switch to a lower sulfur content coal or fuel oil, which would require little to no installation time and may be quite cost-effective. EPA should affirm its longstanding policy regarding concrete, enforceable commitments if a state is to consider a planned retirement in its four-factor reasonable progress analysis. Further, EPA should consider interim cost-effective controls for sources that commit to retire.

6. Prior control decisions, or separate regulatory requirements, do not excuse consideration of more stringent controls.

The application of prior air pollution controls on a source is not an excuse to avoid additional or better-operated controls to achieve reasonable progress. The Final Guidance (Section II.B.3.f.) suggests that sources with recently-installed controls or controls added to comply with other clean air programs might not need to consider further improvements.

In fact, EPA’s own data shows that some plants install controls that are not operated continuously, controls that were never designed to operate at peak efficiency (e.g., undersized systems), and partially bypassed controls. Moreover, EPA has also demonstrated that scrubber upgrades to a number of coal-fired power plants utilizing outdated and inefficient scrubber systems would be highly cost-effective and approach the emission reduction performance of new scrubbers.

Thus, EPA must specify that sources with existing pollution control technology evaluate options that could further reduce emissions through more effective use of that control technology. This could include requiring year-round operation of controls, reducing capacity, imposing more effective percent reduction requirements, requiring sources to meet more stringent emission limits, or requiring that emission limits apply on shorter averaging times to ensure continuous levels of emission reduction. 10See 81 Fed. Reg. at 305. EPA should make clear that states may need to reevaluate reasonable emission control measures for sources that were subject to BART determinations in the first planning period, regardless of any prior control determinations. While many BART-eligible sources installed a level of emission controls (or no controls at all) in round one, many other sources will need to be reassessed.

EPA must clarify that decisions regarding which controls to require as part of long-term strategy cannot rest solely on prior control decisions. For example, costs or technologies that were previously considered unreasonable or infeasible may later become more common and may be necessary in the second or future planning periods to make reasonable progress. Likewise, making reasonable progress in the current and future planning periods will require the implementation of controls that individually account for smaller visibility impacts than those contemplated in the first planning period and in other past emission-reducing rules and permits.

Finally, the requirement to install controls to meet reasonable progress requirements to address regional haze is independent of other regulatory requirements. The Act does not allow states to delay rules meeting these haze requirements on the promise of future controls under another air quality program.

7. States must include both “dominant” and “non-dominant” pollutants in their analyses of controls.

In the Final Guidance, EPA advises states that they may “focus on the [particulate matter] species that dominate visibility impairment at the Class I areas affected by emissions from the state” and skip analyses of controls for sources with “non-dominant” pollutants (Section II.B.3.a.). However, this approach conflicts with the Regional Haze Rule and its preamble, which required “cost-effective controls at sources with significant visibility impacts . . . .” 82 Fed. Reg. at 3088.

EPA’s approach would allow states to improperly determine that because one pollutant has a greater impact on visibility at a Class I area(s), the state may simply ignore other visibility impacting pollutants for one or all sources in the state emitting the non-dominant pollutants, despite the availability of cost-effective controls under reasonable progress criteria. EPA’s approach regarding “dominant” pollutants has potentially far-reaching negative impacts on the Regional Haze Rule’s requirements that states make reasonable progress, as many large sources emit multiple types of visibility impacting pollutants. Further, states might not be able to determine if some pollutants or sources contribute to visibility impairment in Class I area in another state or determine the availability of additional emission reduction measures. 40 C.F.R. § 51.308(f)(3)(ii)(B).

EPA must instruct states to consider and assess all pollutants in their haze plans.

8. States must ensure that Federal Land Manager concerns are considered by the state, and addressed in state plans.

Under the Act, the Federal Land Managers (“FLMs”) play a central role in the haze program and in developing state haze plans.1142 U.S.C. § 7491(a)(2), (d). While EPA affirms states are required to consult with FLMs in the Final Guidance (Section II.B.8.a.), EPA must direct states to not only work collaboratively with FLMs to develop regional haze plans but also to take FLM input as guiding the development of haze plans to ensure public resource protections.


We urge EPA to review and consider our full Petition for Reconsideration, which is attached, and especially to prioritize the issues outlined in this letter in order to provide timely direction to states now preparing their second round haze plans.

Stephanie Kodish
National Parks Conservation Association
777 6th Street NW, Suite 700
Washington, DC 20001-3723

Joshua Smith
Sierra Club
2101 Webster Street, Suite 1300
Oakland, CA 94612

Philip A. Francis, Jr., Chair
Coalition to Protect America’s National Parks
2 Massachusetts Ave NE, Unit 77436
Washington, DC 20013

Georgia Murray
Appalachian Mountain Club
361 Route 16
Gorham, NH 03581

Charles McPhedran
Mychal Ozaeta
1617 JFK Boulevard, Suite 1130
Philadelphia, PA 19103


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