Enclosure

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Nitric Acid New Source Performance Standards – EPA’s Responses to the

Petition for Reconsideration

Background 

The initial Nitric Acid Plants New Source Performance Standards (NSPS) were published in the 

Federal Register (FR) on December 23, 1971 (36 FR 24881) and codified at 40 CFR part 60, subpart 

G, pursuant to section 111 of the Clean Air Act (CAA). Pursuant to section 111(b)(1)(B) of the CAA, 

we have reviewed the NSPS three times. The first review was completed on June 19, 1979 (44 FR 

35265). The second review was completed on April 5, 1984 (49 FR 13654). No changes were made to 

the NSPS as a result of these two reviews. However, based on the results of the third review, which 

we completed in August 2012, we determined it was appropriate to revise the NSPS. The revisions to 

the NSPS based on the third review were published on August 14, 2012 (77 FR 48433). The revisions 

included a change in the nitrogen oxides (NOx) emission limit, from 3.0 pounds of NOx per ton of 

nitric acid production (3.0 lb/T) on a 3-hr basis to 0.5 lb/T on a 30-day average basis, and additional 

testing and monitoring requirements.

Throughout the rulemaking process for this third review, we received comments, data and information

that supported these revisions. This information is contained in the docket which is available at 

http://www.regulations.gov. The revisions were proposed on October 14, 2011 (76 FR 63878). We 

received additional data and comments during the comment period. These data and comments were 

considered and analyzed and, where appropriate, revisions to the NSPS were made. The revised NSPS 

(40 CFR part 60, subpart Ga) were finalized on August 14, 2012 (77 FR 48433). The NSPS apply to 

new, modified or reconstructed nitric acid production units (NAPUs) that commence construction, 

modification or reconstruction after October 14, 2011.

Section 307(d)(7)(B) Requirements

Section 307(d)(7)(B) of the CAA states that “[o]nly an objection to a rule or procedure which was 

raised with reasonable specificity during the period for public comment (including any public hearing) 

may be raised during judicial review. If the person raising an objection can demonstrate to the 

Administrator that it was impractical to raise such objection within such time or if the grounds for 

such objection arose after the period for public comment (but within the time specified for judicial 

review) and if such objection is of central relevance to the outcome of the rule, the Administrator shall 

convene a proceeding for reconsideration of the rule and provide the same procedural rights as would 

have been afforded had the information been available at the time the rule was proposed.”

As to the first procedural criterion for reconsideration, a petitioner must show why the issue could not 

have been presented during the comment period, either because it was impractical to raise the issue 

during that time or because the grounds for the issue arose after the period for public comment (but 

within 60 days of publication of the final action). In the EPA’s view, an objection is of central 

relevance to the outcome of the rule only if it provides substantial support for the argument that the 

promulgated regulation should be revised. See, e.g., the EPA’s “Denial of the Petitions to Reconsider 

the Endangerment and Cause or Contribute Findings for Greenhouse Gases under Section 202 of the 

Clean Air Act,” 75 FR 49556, 49561 (August 13, 2010). See also, 75 FR 49556, 49560 – 49563
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(August 13, 2010) and 76 FR 4780, 4786 – 4788 (January 26, 2011) for additional discussion of the 

standard for reconsideration under CAA section 307(d)(7)(B).

On October 10, 2012, Dyno Nobel Inc. (DNI) submitted a Petition for Reconsideration and judicial 

review of the final rule for Nitric Acid Plants (77 FR 48433). The EPA has carefully reviewed the 

points raised in the Petition and is denying the Petition for the reasons described below. 

A. Subcategory for Modified or Reconstructed Plants that Use NSCR to Control NOx

Claim: The petitioner states that “as EPA long ago recognized,” nonselective catalytic reduction 

(NSCR) is not an end of pipe control technology, as some would describe selective catalytic reduction 

(SCR). The petitioner claims that there are significant and fundamental differences between NAPUs 

using SCR and NSCR. NSCR is designed differently from an SCR because an NSCR is built into, and 

is an integral part of the operation of a NAPU, particularly in terms of heat balance and energy 

generation for other parts of the NAPU. NAPUs with an NSCR must keep temperatures elevated in 

order to create the reductive environment within the unit that eliminates NOx. To ensure temperatures 

and pressures are adequate for this reductive environment, the NSCR is placed upstream of the tail gas 

expander. Because of these differences, the petitioner believes the EPA should have established a 

subcategory for NAPUs with NSCR with regard to emissions limits for modified or reconstruction of 

existing sources.

EPA’s Response: Section 111(b)(2) of the CAA states that “The Administrator may distinguish

among classes, types, and sizes within categories of new sources for the purpose of establishing such 

standards.” Pursuant to this discretionary authority, the general EPA policy is that if one or more 

segments of an industry have significant differences in class, type or size of production processes or 

designs, which result in significant differences in the potential emissions, then we consider developing 

a subcategory or subcategories for these different segments. However, we believe it is inappropriate to 

establish subcategories based on differences in control technologies, and decline to exercise our 

discretion to do so here. 

As we explained in the preambles to the proposed and final rules, the EPA clearly considers NSCR, as 

well as SCR, to be emissions control technologies. Therefore, for this reason alone, it would not be 

appropriate to establish a subcategory for units with NSCR. We are unaware of the basis of DNI’s 

claim that the EPA “recognized” NSCR as not being an emissions control technology. This is 

incorrect. None of the 14 NAPUs in the U.S. using NSCR has additional NOx control after NSCR.

NSCR is the emissions control technology for these 14 NAPUs. There are about 50 NAPUs in the 

U.S. The petitioner owns and operates seven of the 14 NSCR units.

A possible justification for developing a subcategory (or a different emissions limit) for existing 

NAPUs that become subject to this NSPS through modification or reconstruction would be a 

determination that it is technically impossible or cost prohibitive for a number of existing NAPUs 

with NSCR to achieve the NSPS emission limit if these units are modified or reconstructed. As 

described below in section C, there are examples where some existing NAPUs with NSCR already 

achieve the NSPS emission limit and, therefore, would have no additional control costs if they were 

modified or reconstructed. Furthermore, the costs for most other existing NSCR units to comply with 
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the NSPS, if such units were modified or reconstructed, are not expected to be excessive (as described 

further in section D below). If it were the case that the costs to comply with the NSPS for one specific 

NAPU with NSCR were excessive, that would not by itself justify developing a subcategory for one,

or for a very limited number, of the NSPS affected facilities. Thus, there is no basis for

subcategorizing units using NSCR from units using SCR. 

B. Petitioner Believes EPA had Insufficient Data

Claim: The petitioner claims that the EPA cannot meet the legal requirement that data relied on for 

setting an NSPS must be sufficiently “representative of potential industry–wide performance” because 

none of the plants that were tested for the NSPS review (i.e., test plants) use NSCR. Also, the test 

plants in the EPA’s analysis do not face the conditions, limitations in the ability to modify plant 

operations, or the resulting impacts on NOx emissions that NAPUs with NSCR face. The petitioner 

claims the EPA cannot meet the mandates of National Lime Association v. EPA (DC Circuit 1981) 

and Sierra Club v. Costle (DC Circuit 1981) that data used in setting an NSPS must be sufficiently

“representative of potential industry-wide performance.”

EPA’s Response: As required under section 111(a) of the CAA, 1990 Amendments, NSPS emission 

limits are based on the emission levels achieved by the best systems of emission reduction (BSER) 

while considering the costs and any nonair quality health, environmental impact and energy

requirements of these systems. As noted in the preamble to the final rule (77 FR 48436), we 

concluded that SCR is BSER for NAPUs. As discussed in detail in the preambles to the proposed and 

final rule as well as the Response to Comment document, we determined we had ample emission test 

data to support SCR as BSER and that we had sufficient data to determine the appropriate revised 

emissions limit for NOx. However, we also explained that the NSPS does not require the use and 

installation of a specific control device as long as the affected facility complies with the NSPS. For 

example, as described in more detail in section C below, available data indicate that some NAPUs 

with NSCR can meet the revised limit without the need for any additional controls.

C. Achievability of Complying with Standard for Existing Plants Using NSCR 

Claim: The petitioner claims that there are insufficient data showing that existing plants using NSCR 

can meet the emission limit. The petitioner notes that there was no notice in the proposed rule that the 

EPA would use continuous emissions monitoring system (CEMS) data from DNI’s Oregon plant as 

the primary basis for supporting the rule for NSCR. The petitioner believes that this plant is not 

representative of NAPU using NSCR in the U.S. for at least three reasons. First, the plant is very

small, only 70 tons per day (TPD) of nitric acid is produced. DNI’s largest NAPU produces 520 TPD. 

Second, the plant is not a typical NAPU as it was built for the sole function of scrubbing emissions 

from an on-site urea plant. This plant functions without maximizing acid purity or production rate as 

do other NAPUs. Thus, the relative vessel sizes and flow rates that are found in an NSCR used at a 

commercial NAPU are much different than DNI’s Oregon plant. Third, the fuel used for the plant’s 

NSCR (purge gas from an on-site ammonia plant – 65-percent hydrogen) is unusual. Four of DNI’s 

seven NAPUs with NSCR use methane which, according to the petitioner, is the common fuel for 

NSCRs at NAPUs. The petitioner also claims that the use of hydrogen in fuel results in significantly 

lower NOx emissions at the Oregon plant. Furthermore, the petitioner states that the only other data
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cited by the EPA to support that the NSPS emissions limit is achievable for NAPUs with NSCR are 

monthly averages from the JR Simplot plant, which, according to the EPA, indicate a “strong 

probability” that this NAPU with NSCR would comply with this NSPS.

EPA’s Response: As noted in the preambles to the proposed and final rules, the EPA has determined 

that SCR is BSER, so there is no requirement that the EPA conclude that NAPUs with NSCR can 

meet the revised limit without additional controls. Nevertheless, we still evaluated the potential for 

NAPUs with NSCR to achieve the revised limit. As explained further below, we disagree that there 

are insufficient data showing that some existing plants with NSCR can achieve the revised limit. 

As noted in the preamble to the proposed rule, we had long term CEMS data from two NAPUs with 

NSCR which indicated difficulty in meeting the NSPS emission limit. However, we also noted we had 

monthly block averages (often 30-day periods, which are the same time period of the NSPS emission 

limit) from two other facilities using NSCR, including DNI’s Oregon plant (also known as the Deer 

Island plant or St. Helens plant) and the JR Simplot-Helm plant, that indicated these plants are 

achieving the NSPS limit. We noted that the monthly averages for both plants ranged from 0.15 to

0.36 lb NOx/T of 100-percent acid; well below the emission standard of 0.50 lb/T. We also noted that 

since these data were not rolling 30-day averages like the NSPS emission limit, but rather monthly

averages, it was not exactly a direct comparison with CEMS data. However, we stated that these 

monthly averages indicate that at least some NAPUs with NSCR would be able to achieve the 

emission limit without additional controls (76 FR 63882).

In the preamble to the final rule (77 FR 48437), we provided additional information and analyses that 

indicate the same two NAPUs with NSCR described in the proposal (i.e., DNI’s Oregon Plant and JR 

Simplot-Helm plant) can meet the NSPS emission limit. Regarding the DNI Oregon plant, we 

received CEMS data for this plant after proposal that allowed us to calculate 30-day rolling averages. 

Based on these data, we determined that the maximum rolling 30-day emission rate was 0.21 lb/T acid

for the DNI Oregon plant, which is well below the NSPS limit of 0.50 lb/T. Regarding the JR 

Simplot-Helm plant, we explained again that, based on available data, this plant had monthly averages 

that ranged from 0.15 to 0.36 lb/T, which indicates this unit can also achieve the limit of 0.50 lb/T. 

Therefore, similar to the proposal, we concluded again in the preamble to the final rule that the NOx

emission limit was achievable for some NAPUs with NSCR. 

Since the final rule, we have re-analyzed the JR Simplot data, which includes CEMS data. This reanalysis of JR Simplot CEMS data showed that it is possible to determine 30-day rolling averages for 

this unit. For the period, January 1, 2011, thru August 1, 2011, the 30-day rolling averages range from 

0.063 to 0.19 lb/T. The average 30-day average was 0.11 lb/T. Thus, this unit, which is controlled 

with NSCR, easily meets the NSPS emission limit. 

With this re-analysis of the JR Simplot data, we have CEMS data from two NAPUs with NSCR that 

clearly achieve the NSPS limit. Parameters for the JR Simplot plant refute DNI’s contention that the 

DNI plant in Oregon is only able to meet the emission limit because it is non-representative of NAPUs

with NSCR for the three points that DNI mentions. The JR Simplot plant is larger (230 TPD) than 

DNI’s Oregon plant (41 TPD). The sole plant function at JR Simplot is to produce nitric acid. It also 
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uses a fuel for NSCR (butane) that is similar to methane used in four of the seven NSCR controls at 

DNI plants.

While reviewing DNI’s reconsideration petition, we requested CEMS data for DNI’s other plants with 

NSCR. DNI submitted data for two of their other units with NSCR, including the only unit with 

NSCR that DNI identified as being considered for modification (i.e., Unit 3 at DNI’s Cheyenne, 

Wyoming plant). These data indicate that for many 30-day periods, Unit 3 had emissions below the 

NSPS limit. We acknowledge that this existing NAPU has not achieved emissions below the NSPS 

limit for all periods in the past. However, that does not mean that they would not be able to comply

with the NSPS emission limit in the future if they decide to modify this unit, especially if they take 

reasonable measures to improve process operations and/or add emissions controls during the 

modification or reconstruction process.

It is uncertain what equipment and/or controls DNI would have to install in order to be in continuous 

compliance with the NSPS if they decided to modify or reconstruct this unit. Nevertheless, we expect 

that by adding a pre-heater, they could significantly reduce their NOx emissions during startups and

shutdowns. Furthermore, by changing the catalyst more frequently, they could decrease their NOx

emissions. We believe by applying these two relatively inexpensive measures, it is likely that this DNI

unit could be in continuous compliance with the revised NSPS limit. Otherwise, the other option 

would be to install an SCR control which would be more expensive, but still reasonable. Costs for 

retrofitting an SCR are described below in section D.

D. Costs of Complying for Modified or Reconstructed NAPUs Currently Using NSCR 

Claim: The petitioner claims that it would not be possible to meet the NOx standard without costprohibitive retrofits for existing NAPUs with NSCR. The petitioner stated that it is considering 

modifying a plant that currently uses NSCR and claims that retrofit costs required for an NSCR plant 

to install SCR and meet the NSPS were not considered in the rulemaking.

The petitioner also claims the EPA stated in its proposed rule that it was “uncertain” whether NAPUs 

with NSCR could meet the NOx emission limit as the EPA had not reviewed any CEMS data for these 

units that met this limit. The petitioner states that the EPA did not evaluate the additional steps that are 

required for these units to meet the emission limit. Also, according to the petitioner, the EPA did not 

evaluate the impacts these steps would have on operations and the costs for these steps. 

In December 2012, after DNI submitted its petition, in response to questions from the EPA, DNI

supplied information on estimated costs for its Donora, PA plant to retrofit SCR to an existing NAPU 

with NSCR. With these estimates, DNI asserts that the total annual cost to retrofit the Donora unit to 

install an SCR would be an estimated $1,565,000, and that the cost effectiveness of this control would 

be $11,000 per ton of NOx removed.

EPA’s Response: As noted in the preamble to the final rule (77 FR 48439), we evaluated the costs of 

controls for an actual NAPU plant that was modified. The plant installed SCR at a capital cost of 

$2,700,000. The cost effectiveness was $1,360/T of NOx removed. We concluded that these costs and 

cost effectiveness were reasonable.
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The EPA concludes that retrofitting a NAPU with an NSCR to add SCR (or add other control 

measures) to meet the NSPS would not, in the vast majority of circumstances, incur substantially more 

costs than retrofitting any other NAPU. With regards to the Donora unit, it has a unique design, is the 

only remaining NAPU of its kind and is equipped with a 1960s era NSCR device that is considerably 

less effective than more modern NSCR devices. For this reason, the Donora NAPU emits 

considerably more NOx than most NSCR controlled NAPUs, and retrofitting it with an SCR may

present engineering challenges and potential additional costs that would not be present for retrofitting 

the vast majority of other NAPUs. Therefore, the EPA believes these estimated costs provided by DNI

are not representative of a typical existing NAPU with NSCR that may need to retrofit controls to 

meet the NSPS.

Most existing NAPUs use SCR, the control technology that we determined is the BSER. There are no 

expected additional control costs for most (or all) of these units if they are modified or reconstructed 

and become subject to the NSPS, as we expect most (or all) of existing NAPUs with SCR to be in 

compliance with the emission limit. For a few cases, minimal changes may be needed for NAPUs

with SCR and, if so, costs are expected to be low. 

For the 14 NAPUs with NSCR, some already are complying with the NSPS (e.g., the DNI Oregon and 

JR Simplot plants), so little or no control costs would be incurred if these existing NAPUs with NSCR 

become subject to this NSPS through modification or reconstruction. Control costs may well be 

minimal or zero for several other of the 14 NSCR units. Some NAPUs with NSCR could incur larger 

costs if they become subject to the NSPS, but the costs are generally not expected to be more than 

$1,360/T. Finally, even if there are one or a few NAPUs with NSCR that would not be able to 

meet this NSPS in a cost-effective manner, courts have recognized that an NSPS may be considered 

"adequately demonstrated" even if not all existing sources would be able to meet it. Portland Cement 

Assn. v. Ruckelhaus, 486 F.2d 375, 391 (D.C. Cir. 1973) ("We begin by rejecting the suggestion of the 

cement manufacturers that the Act's requirement that emission limitations be ‘adequately 

demonstrated' necessarily implies that any cement plant now in existence be able to meet the proposed 

standards.").

It should be noted that rather than the Donora unit, the NAPU that DNI is considering modifying is 

Cheyenne Unit 3. The additional air pollution control/practices and associated costs needed for 

Cheyenne Unit 3 are uncertain. However, as shown in section C above, CEMS data for this unit show

many periods of compliance. Furthermore, there are a number of possible options under which this 

unit could meet the revised NSPS for a reasonable cost. First, an SCR might not have to be installed. 

For example, we believe Unit 3 could potentially comply by fine tuning the NSCR, adding additional 

catalyst to the NSCR, adding a preheater to lower NOx emissions during startups and replacing the 

catalyst more frequently. If these measures did not achieve the NSPS emission limit, Cheyenne’s Unit 

3 could possibly comply with the NSPS by installing a “mini” SCR with much less catalyst and using

much less ammonia than a full-size SCR. In any event, making retrofits or other improvements 

necessary to meet the NSPS at Cheyenne Unit 3 would be considerably less expensive than what DNI

claims would be necessary for the Donora unit. Since DNI’s cost estimates are entirely based on the 

cost of retrofits to the Donora unit, the cost of retrofitting Cheyenne Unit 3 would be much lower than 

estimated by DNI, and are likely consistent with the EPA’s estimated cost-effectiveness value of 

$1,360/T for a modified or reconstructed NAPU (77 FR 48442). Nevertheless, as stated above in 
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section A, if the costs for most plants would be reasonable, but costs for an individual NAPU are

considerably higher, that itself would not justify developing a subcategory for one or for a very

limited number of NAPUs.

Finally, an in-depth look at DNI’s Donora plant estimates suggests that these costs could be 

overestimated. We note that the estimated annual cost provided by DNI associated with retrofitting the 

Donora unit is mostly energy costs ($916,000 per year or 59 percent of the total annual cost)

calculated based on steam losses associated with the removal of an economizer that DNI asserts is 

necessary to accommodate the installation of an SCR. We believe more cost-effective options likely 

exist for replacing this lost steam, such as installing a replacement economizer, that were not 

evaluated in DNI’s analysis.

E. DNI Did Not Have a Chance to Comment on Analysis Presented in Final Rule 

Claim: The petitioner states that section 307(d)(7)(B) of the CAA requires the EPA to grant 

reconsideration when the petitioner:

“[C]an demonstrate to the Administrator that is was impracticable to raise [an] objection [during 

the period for public comment] or if the grounds for such objection arose after the period for public 

comment...and if such objection is of central relevance to the outcome of the rule.”

The petitioner further states the standards for reconsideration are clearly met. First, no interested 

party, including DNI, had any notice in the proposed NSPS that the EPA would utilize CEMS data 

from DNI’s Oregon plant as the primary basis for supporting the rule’s application to NAPUs with 

NSCR and rejecting the petitioner’s request for a separate emission limit for these units. This is 

clearly stated in the preamble to the final rule as the EPA admits that these data were evaluated “after 

proposal.” If the EPA had included this evaluation in the proposed rule, the petitioner states that they

would have commented that DNI’s Oregon plant is not representative of overall industry performance 

of NAPUs with NSCR. 

Also, the petitioner stated that, as noted in their subsequent comments regarding the DNI Oregon 

plant, their objection is most certainly “of central relevance to the outcome.” The petitioner states that 

DNI’s Oregon plant is the only hourly CEMS data showing compliance with the NSPS emission limit. 

Thus, the petitioner believes that the Nitric Acid NSPS is arbitrary and capricious as it relates to 

NAPU with NSCR.

EPA’s Response: First, it should be noted that data for DNI’s Oregon plant were described in the 

preamble to the proposed rule. At proposal, we stated we had monthly block averages for this NAPU,

as well as for the JR Simplot plant (76 FR 63882). These averages were well below the NSPS 

emission limit. These averages were not 30-day rolling averages, however, these data still indicated

these two NSCRs could likely meet the NSPS emission limit of 0.50 lb/T on a 30-day rolling average.

The data that the EPA further evaluated after proposal and prior to promulgation were hourly CEMS

data for DNI’s Oregon plant that we requested in the preamble to the proposed rule. These data were 

requested to assist in evaluating whether NSCR can achieve the NSPS emission limit. The rolling 30-
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day averages for this NAPU with NSCR meet the NSPS emission limit. We also had data from 

another NAPU controlled by NSCR, JR Simplot, as described above (in section C). In the proposal, 

we noted that monthly averages from the JR Simplot plant were below the revised limit. After the 

final rule was promulgated, we re-analyzed data from the JR Simplot plant based on evaluation of 

hourly CEMS data. The re-evaluation of the JR Simplot hourly data also show that JR Simplot’s 

emissions are well below the NSPS emission limit and could easily comply with the NSPS. The 

CEMS data for these two NAPUs with NSCR show that the NSPS emission limit can be achieved by 

some NAPUs with NSCR.

F. Conclusion

In response to the reconsideration petition, we have reviewed the data/analysis supplied by the 

petitioner. Also, we have reviewed and analyzed previously available data to evaluate the claims made 

in the reconsideration petition. Our responses to all issues raised by the petitioner are explained in 

detail above in sections A through E, and summarized below.

Regarding the petitioner’s request for a subcategory for modified or reconstructed nitric acid plants 

that use NSCR, the main points are as follows:

 First, in section A, we explained that we believe it is inappropriate to establish subcategories 

based on differences in control technologies, so it is inappropriate to establish a subcategory

for plants using NSCR. Also, we believe it is technically possible for existing NAPUs with 

NSCR to achieve the NSPS emission limit if they were to be modified or reconstructed. 

 Second, as described in sections C – E above, we believe it is feasible for some units with 

NSCR to comply with this NSPS without the need for any additional controls as some existing 

units with NSCR are already achieving the NSPS emission limit. 

 Third, as described in section D above, we believe other units with NSCR that are modified or 

reconstructed, could comply with the NSPS limit by improving their controls at reasonable 

costs. 

Finally, regarding the petitioner’s argument that the EPA did not meet the legal requirement of having 

representative emission data to set an emission limit, as explained in section B above, we had ample 

test data to support SCR as BSER and to establish a revised emission limit.

Therefore, based on our review and evaluation of all issues raised by the petitioner and relevant 

available data and information, we have concluded that reconsideration is not warranted.