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August 12, 2016 

Submitted via www.regulations.gov 

Attention Docket ID No. EPA-R09-OAR-2015-0846 

Vijay Limaye 

U.S. EPA, Region 9 

Air Division (AIR-2) 

75 Hawthorne Street 

San Francisco, CA 94105 

Re: Arizona Regional Haze – Reconsideration of Reasonable Progress Controls for the 

Rillito and Clarkdale Cement Plants 

Dear Mr. Limaye: 

 On behalf of National Parks Conservation Association (NPCA) and Sierra Club, 

Earthjustice respectfully submits the following comments on the Environmental Protection 

Agency’s (EPA) reconsideration of the reasonable progress controls for the Rillito and Clarkdale 

cement plants. 81 Fed. Reg. 42,600 (June 30, 2016). For the reasons discussed below, we urge 

EPA to reconsider its earlier rejection of Selective Catalytic Reduction (SCR) controls at the two 

cement plants. EPA previously rejected SCR because at the time of the earlier rulemaking, SCR 

had not been installed on cement plants in the United States. That is no longer the case. A 

cement plant in Illinois has recently installed and successfully operated SCR. Moreover, 

another cement plant in Texas plans to begin operating SCR controls in the fall of 2016. 

Consequently, in this rulemaking, EPA should fully analyze whether SCR at the two Arizona 

cement plants would ensure reasonable progress. 

 EPA’s regional haze Federal Implementation Plan (FIP) for Arizona requires the Rillito 

Cement Plant Kiln 4 and the Clarkdale Cement Plant Kiln 4 to install Selective Non-Catalytic 

Reduction (SNCR) controls. 79 Fed. Reg. 52,420, 52,426 (Sept. 3, 2014). EPA determined that 

SNCR controls are necessary to ensure reasonable progress toward eliminating all human-caused 

visibility impairment at national parks, wilderness areas, and other Class I areas by 2064. Id. 

When EPA examined reasonable progress controls for the two cement plants in 2013-

2014, it initially rejected SCR controls as technically infeasible. Docket No. EPA-R09-OAR2013-0588, Technical Support Document for the Proposed Phase 3 Action 92–93, 105–06 (Jan. 

27, 2013). NPCA and Sierra Club submitted comments demonstrating that SCR is technically 

feasible, as it has been installed on several cement kilns in Europe. See 79 Fed. Reg. at 52,460. 

In response to these comments, EPA clarified that SCR is technically feasible on cement kilns. 

However, EPA explained that it did not fully examine SCR on the two Arizona plants because 
2 

SCR controls had not been installed on any cement kilns in the United States at that time. 

Specifically, EPA stated: 

We agree that SCR is technically feasible. We clarify that although SCR was not 

further considered after Step 2 (Eliminate Technically Infeasible Options) of the 

RP analysis, we consider SCR a technically feasible control option. While we 

explicitly eliminated other control options in Step 2 as technically infeasible, we 

elected not to consider further SCR due to a lack of information that would allow 

us to evaluate its effectiveness and cost of controls on cement kilns. In 

particular, we note that SCR has not been commercially applied to a cement 

plant of any type in the United States, and there is little information available 

about its use on cement kilns in other countries. Thus, we lack sufficient 

information to conduct a four-factor analysis for SCR on cement kilns. 

Id. (emphasis added and parenthetical and footnote omitted); see also id. at 52,461–62 (same). 

 Since EPA issued its FIP in September 2014, at least two cement plants in the United 

States have installed SCR. In 2013, EPA entered into a consent decree with the Lafarge 

Company that required Lafarge’s Joppa, Illinois cement plant to install SCR.1

 The SCR controls 

at the Joppa cement plant have now been in operation for more than a year. According to EPA, 

“The SCR at the Joppa IL kiln is successfully operating,” and it has achieved “an emission 

reduction of about 80% which was the goal of the [consent decree].”2 Furthermore, LaFarge 

itself has reportedly claimed that “the SCR control technology performed well and no 

operational problem was encountered.”3 

 In addition, Holcim’s Midlothian cement plant in Texas has been granted a permit to 

install SCR on one of its two kilns.4 Notably, the owner and operator of this cement plant 

voluntarily chose to install SCR, and the SCR will soon begin operations in the fall of 2016.5

 

 In the current rulemaking, EPA proposes to relax the existing FIP requirements for the 

Rillito and Clarkdale cement plants because of recent information regarding SNCR performance 

on other cement kilns in the United States. 81 Fed. Reg. at 42,602–03. Specifically, EPA has 

reviewed recent SNCR performance data from the Mojave cement plant in California. EPA 

believes this recent SNCR data from California justifies replacing the existing “control 

optimization” requirements for the two Arizona plants with less stringent recordkeeping and 

reporting requirements. Id. 

                                                     

1

 See EPA, Lafarge North America, Inc. Clean Air Act Settlement, 

https://www.epa.gov/enforcement/lafarge-north-america-inc-clean-air-act-settlement (last visited 

August 12, 2016). 

2

 E-mail from Kushal Som, Envtl. Eng’r, EPA Region 5, to Jim Schermbeck (July 21, 2015, 

18:18 CST) (Ex. 1). 

3

 McIlvaine Co., NOx Control, Decision Guide Webinar, at 73, available at 

http://goo.gl/UhZhvX (Ex. 2). 

4

 See Texas Comm’n on Envtl. Quality, Notice of Application and Preliminary Decision For an 

Air Quality Permit (Oct. 17, 2014), available at http://goo.gl/5ONhVl (Ex. 3). 

5

 McIlvaine Co., NOx Control, Decision Guide Webinar, at 73 (Ex. 2). 
3 

 If EPA is going to revise the existing FIP’s requirements based on recent data from a 

cement plant in California, it should also examine the recent success of SCR controls at the 

cement plants in Illinois and Texas. Reconsidering the FIP’s requirements based on recent data 

from other plants should not be a one-way ratchet toward weakening the FIP’s requirements. 

Instead, in order to make a reasonable and fully-informed decision on reconsideration, EPA 

should also re-examine whether more stringent SCR controls are warranted.6

 Doing so is 

especially important because EPA’s earlier rationale for rejecting SCR is no longer valid, as SCR 

is now a proven control technology on cement plants in the United States. As a result, sufficient 

information now exists for SCR to be considered in a full four-factor reasonable progress 

analysis. As this recent experience with SCR in Illinois and Texas shows, SCR can successfully 

and cost-effectively remove large amounts of nitrogen oxides pollution from cement kilns. 

Moreover, industry consultants have recently noted that SCR is a proven technology that has 

been increasingly installed on cement kilns in recent years.7

 Given this recent information 

documenting the success of SCR at cement plants, EPA should reconsider whether SCR at the 

Rillito and Clarkdale plants is necessary to ensure reasonable progress. 

 In addition, if EPA continues to require the two cement plants to install SNCR, rather 

than SCR, it should not eliminate the FIP’s SNCR “control optimization” requirements. As EPA 

noted earlier, SNCR on cement plants can achieve a wide range of control efficiencies. 79 Fed. 

Reg. at 52,455 (noting SNCR control efficiencies ranging from 30-90%). Thus, EPA explained 

that “a site-specific optimization program at [the Rillito and Clarksdale plants] could identify 

operating parameters and conditions that could result in an SNCR control efficiency greater than 

50 percent.” Id. To ensure the SNCR controls on the two cement plants achieve maximum 

pollution reductions, EPA required the plants to comply with several “control optimization” 

requirements. Id. at 52,455–56. Now, EPA proposes to eliminate these requirements because 

recent data shows that SNCR on the Mojave plant in California achieved 40% control efficiency, 

“which is on the lower end of the range that was suggested by the optimization protocol.” 81 

Fed. Reg. at 42,602. However, the fact that the Mojave plant’s SNCR performance was 

underwhelming does not warrant eliminating the requirement that the two Arizona plants 

optimize their SNCRs. The entire point of the “control optimization” requirement is to ensure 

the Arizona plants identify the “operating parameters and conditions” that will result in 

maximum pollution reductions, which is a site-specific inquiry. Thus, even if the Mojave plant’s 

optimization protocol did not result in significant SNCR improvements, that does not mean the 

Arizona plants’ optimization requirements would be similarly unsuccessful. In fact, EPA 

explicitly notes how the two Arizona plants differ from the Mojave plant. See id. at 42,602–03. 

This shows that the results of the Mojave plant’s optimization protocol may not be a good 

predictor of whether the optimization requirements at the Arizona plants can improve SNCR 

                                                     

6

 While EPA granted reconsideration of the FIP’s SNCR “control optimization” requirements, 

the agency has inherent authority in a reconsideration proceeding to consider additional issues raised 

in public comments. See, e.g., 75 Fed. Reg. 17,004, 17,007 (Apr. 2, 2010) (after receiving public 

comments on significant new issues, EPA’s final action on reconsideration “reflect[ed] additional 

interpretations and EPA statements of policy on topics not discussed in the [initial] notice,” and “[i]n 

subsequent actions, EPA may address additional topics raised in public comments on this action.”) 

7

 See, e.g., John Kline Consulting, Is SCR Technology Coming (Back) to Cement? (Apr. 2013) 

(Ex. 4). 
4 

performance. Ensuring that the Rillito and Clarksdale SNCRs achieve maximum pollution 

reductions remains critically important to reducing air pollution at national parks and wilderness 

areas. As a result, the “control optimization” requirements that make sure this occurs should 

remain in place, regardless of the recent experience at the Mojave plant. 

 We appreciate EPA’s work on the Arizona regional haze plan and we thank you for 

considering these comments. 

Sincerely, 

Michael Hiatt 

Earthjustice 

633 17th Street, Suite 1600 

Denver, CO 80202 

(303) 996-9617 

mhiatt@earthjustice.org 

On behalf of National Parks Conservation Association and Sierra Club 

cc: Kevin Dahl, Stephanie Kodish, Nathan Miller – National Parks Conservation 

Association

 Sandy Bahr, Bill Corcoran, Gloria Smith – Sierra Club