December 6, 2012



# National Emission Standards for Hazardous Air Pollutant Emissions for Chemical Manufacturing

Area Sources

- Reconsideration

Summary of Public Comments and Responses on Proposed Rule (77 FR 5422, January 30, 2012)

U.S. Environmental Protection Agency Office of Air Quality Planning and Standards Sector Policies and Programs Division Research Triangle Park, NC 27711December 6, 2012

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## Foreword

This document provides responses to public comments on the U.S. Environmental Protection Agency’s (EPA’s) proposed revisions to the “ National Emission Standards for

Ha zardous Air Pollutants for Chemical Manufacturing Area Sources. ” The EPA Docket contains all comment letters submitted and are available for viewing at the EPA Docket Center Reading Room, or electronically through h ttp://www.regulations.gov by searching Docket ID EPA

- HQ

OAR

- 2008

- 0334 by docket number. This document provides a summary of the significant public comments entered into the docket regarding specific issues and topics related to the development of the propo sed amendments to the subject rules and the EPA’s responses to those comments. Within each comment summary, the EPA provides in parenthesis one or more Docket ID numbers for commenters who raised particular issues. However, the list of commenter ID numbers is not meant to be exhaustive. The EPA does not individually identify each and every commenter who made a certain point in all instances, particularly in cases where multiple commenters express essentially identical arguments. Although portions of the pre amble to the final rule are paraphrased in this document, to the extent any ambiguity is introduced by paraphrasing, the preamble itself remains the definitive statement of the rationale for the final rule.December 6, 2012

iii 

## Table of Contents

1.0 Background

................................ ................................ ................................ .......................... 1

2.0 Title V Permitting Requirements

................................ ................................ ......................... 4

3.0 Requirements When Other Rules Overlap With the Final Rule

................................ .......... 7

4.0 Requirement to Conduct Direct and Proximal Leak Inspections

................................ ......... 8

5.0 Requirement for Covers or Lids on Process Vessels

................................ ........................... 8

6.0 Requirement to Conduct Leak Inspections When Equipment Is in HAP Service

............... 9

7.0 Applicability of the Family of Materials Concept

................................ ............................. 10

8.0 Startup, Shutdown, and Malfunction

................................ ................................ ................. 11

9.0 Affirmative Defense

................................ ................................ ................................ ........... 12

10.0 Metal HAP Process Vents

................................ ................................ ................................ .. 18

11.0 Applicability

................................ ................................ ................................ ...................... 19

12.0 Complianc e Date

................................ ................................ ................................ ................ 21

13.0 Definitions

................................ ................................ ................................ .......................... 21

14.0 Other/Technical Corrections

................................ ................................ .............................. 22December 6, 2012

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1 

## 1.0 Background

On January 30, 2012 (77 FR 4522), the U.S. Environmental Protection Agency (EPA or agency) proposed to revise the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Chemical Manufacturing Area Sources (CMAS) in p art in response to a petition for reconsideration from the American Chemistry Council (ACC) and the Society of Chemical Manufacturers & Affiliates (SOCMA) (collectively, “the petitioners”). The EPA has summarized and responded to several comments in the pr eamble to the EPA’s final action. This document presents summaries of the additional comments that were submitted and the EPA’s responses to those comments. The comments to which the EPA is responding to were submitted in 19 letters from industry represent atives, governmental entities, and private citizens during the public comment period. In addition, the EPA received six comments and sets of materials from industry representatives following the close of the comment period. Although the EPA is not required to respond to these comments, to the extent practicable the EPA has responded to the late comments and our responses to such comments are also presented in this document. A list of the commenters, their affiliations, and the EPA docket number assigned to their correspondence is presented in Table 1.

TABLE 1. LIST OF COMMENTERS ON PROPOSED NATIONAL EMISSIONS

STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR CHEMICAL

MANUFACTURING AREA SOURCES

Docket Number a,b Commenter and Affiliation

116 Karen Thorne, Louisvi lle Metro Air Pollution Control District

117 Alex Berger, Hospira Boulder

118 Sheila Holman, North Carolina Department of Environment and Natural

Resources

119 Catharine Fitzsimmons, Iowa Department of Natural Resources

120 Paul Aud, Louisville Metro Air Pollution Control District

121 Shelley Schneider, Nebraska Department of Environmental Quality

122 Desi Chari, The Dow Chemical Company

123 Timothy Lafond, Battery Council International

124 David Darling and Tim Serie, American Coatings Association

125 Jeffrey Lang, Rhodia

126 Melvin Keener, Coalition for Responsible Waste IncinerationDecember 6, 2012

2 Docket Number a,b Commenter and Affiliation

127, 134 Carroll Wade McGuffey III, Tronox

128 Lorraine Gershman, American Chemistry Council

129 Barry Christensen, Occidental Chemical Corporation

130 Monte Shaw, Iowa Renewable Fuels Association

131 Russell Frye, SSM Coalition

132 Ron Walton, Clariant Corporation

133 Daniel Moss, Society of Chemical Manufacturers & Affiliates

135 Jade Fisher, Private Citizen

136

(Late Comment) Lorraine Gershman, American Chemistry Council

137

(Late Comment) Desi Chari, The Dow Chemical Company

138

(Late Comment) Leslie Hulse, American Chemistry Council

139

(Late Comment) Lorraine Gershman, American Chemistry Council

140

(Late Comment) Lorraine Gershman, American Chemistry Council

141

(Late Comment) Lorraine Gershman, American Chemistry Council

a Document ID identifies comments found in Docket No. EPA

- HQ

- OAR

- 2008

- 0334 by document number.

b Individual comments from the public (and attachments submitted with comments) submitted to the docket are assigned a unique 4

- digit docket number that follows the base docket number (i.e., EPA

- HQ

- OAR

- 2011

- 0334

- XXXX, where “XXXX” represents the unique 4

- di git document docket number). The unique document docket numbers presented in this table and document represent that unique docket number without the preceding “0”. For example,

docket number EPA

- HQ

- OAR

- 2008

- 0334

- 0116 is presented as 116 in this table and w ithin the text of this document.December 6, 2012

3 A total of 19 written comments were received during the public comment period on the proposed revisions to the CMAS rule as part of the EPA’s reconsideration. The following sections provide a summary of these comments, as well as the EPA’s responses to these comments. We also provide summaries of the 6 late comments and materials submitted after the close of the comment period, and any responses thereto. For the purpose of orderly presentation, the comments have been categ orized under the following topics:

Section 2: Title V Permitting Requirements Section 3: Requirements When Other Rules Overlap With the Final Rule Section 4: Requirement to Conduct Direct and Proximal Leak Inspections Section 5: Requirement for Covers or Lids on Process Vessels Section 6: Requirement to Conduct Leak Inspections When Equipment Is in HAP Service Section 7: Applicability of the Family of Materials Concept Section 8: Startup, Shutdown, and Malfunction

Section 9: Affirmative Defense

Section 10: Metal HAP Process Vents Section 11: Applicability Section 12: Compliance Date

Section 13: Definitions

Section 14: Other/Technical CorrectionsDecember 6, 2012

4 

## 2.0 Title V Permitting Requirements

Comment 2.1: One commenter (132) stated that the distinction between synthetic area sources that have taken operational limits to maintain area source status and those that have installed controls for the purposes of requiring a title V permit is baseless, and that th ere is no substantive difference in the impact of the emissions on the environment. Response 2.1: The EPA continues to believe that it is appropriate to make the distinction between synthetic area sources that installed controls and those that took operati onal limits. In the preamble to the 2009 final rule, the EPA noted that the CMAS categories are different from other area source categories we have exempted from title V because the CMAS categories include a large number of synthetic area sources that inst alled controls to significantly reduce their hazardous air pollutant (HAP) emissions and the sources in the other categories generally have considerably lower emissions of HAP before control. We then stated that at least 10 percent of the estimated 75 faci lities that are synthetic area sources for HAP by virtue of installing controls have uncontrolled HAP emissions over 100 tons per year (tpy). We also indicated that our information showed that many of the sources are located in cities, and often in close

p roximity to residential and commercial centers where large numbers of people live and work. We further stated that these synthetic area sources have significantly higher emissions potential when uncontrolled than the other sources in the CMAS categories, a nd that they are much more like the major sources of HAP subject to the Hazardous Organic Chemical Manufacturing NESHAP (HON) and the Miscellaneous Organic Chemical Manufacturing NESHAP (MON). Commenters have not provided data or other information to rebut our assessment of the CMAS categories or shown that the sources that took operational limits have potential emissions that approach the potential emissions of the synthetic area sources that installed controls.

Comment 2.2: One commenter (138) noted that there are a similar number of synthetic area sources in the boiler area source category and that they are not being subjected to title V. The commenter does not believe that the number of sources affected by the title V requirement suggests that reliance on the Federally Enforceable State Operating Permit (FESOP) program is inadequate, but rather is a sign of the effectiveness and efficiency of the program. Response 2.2: The EPA disagrees with the commenter that the decision not to require title V for the boiler area source category has any implications on the decision to require title V in this rule. The decision to require title V for certain CMAS facilities was based on the specific facts associated with the CMAS categories as set forth in the rulemakin g record, including the preamble to the 2009 final rule (74 FR 56013

- 56014). The commenter has not demonstrated that the facts associated with the boiler area sources are similar to the CMAS area sources, including whether the synthetic area sources in boi lers that installed controls have similar potential emissions to the potential emissions we identified for CMAS synthetic area sources that installed

controls. Further, the commenter appears to assume that all FESOP programs are equivalent and

that the EPA has concluded that FESOP programs are inadequate. We do not agree with the commenter and note that the decision to require title V was not based on a conclusion that FESOP programs are generally “inadequate,” as stated by the commenter. Instead, for the

r easons stated in the record, the EPA determined that title V permitting was appropriate for a certain subset of CMAS facilities.December 6, 2012

5 Comment 2.3: One commenter (138) questions what was meant by the EPA’s assumption that “at least” 10 percent of the estimated 75 synthetic area CMAS facilities “have uncontrolled HAP emissions over 100 tpy.” Response 2.3: The EPA’s estimate that at least 10 percent of the synthetic area source facilities have uncontrolled emissions greater than 100 tpy means that, but for the in stallation of air pollution control devices, emissions from these facilities would be in excess of 100 tpy.

Comment 2.4: One commenter (122) stated that the title V permit requirement should only apply to facilities that installed a federally

- enforceable control device after the proposal date of an otherwise applicable maximum achievable control technology (MACT) standard in order to become a synthetic area source. Response 2.4: The EPA disagrees that the title V requirement should only apply to

sources th at installed a control device after an applicable MACT standard was proposed, as we do not believe that the installation date of the control device is relevant for this requirement. Regardless of when the controls were installed, these facilities would be major sources of HAP emissions but for the use of the control device(s). We believe these sources are generally larger than area sources that took operational limits and natural area sources and that title V is appropriate for such sources.

Comment 2.5: O ne commenter (122) stated that if the EPA finalizes the title V permit requirement, it should clarify that a facility that installed a federally

- enforceable control device

for non

- Table 1 HAP and the facility is only subject to the CMAS rule due to the pre sence of Table 1 metal HAP, or vice

- versa, is not subject to the title V permit requirement. The commenter believed that this is consistent with previous responses to comments by the EPA. Response 2.5: The EPA believes that the revised title V requirement accomplishes what the commenter suggests and provides a straightforward approach for determining applicability of title V. As finalized, the title V requirement applies only to facilities that installed a federally

enforceable control device on an affected chemical manufacturing process unit (CMPU). Thus, if a facility installed a federally

- enforceable control device on the CMPU containing only non

Table 1 HAP (and is therefore not subject to the CMAS rule), and did not install a federally

enforceable contr ol device on the CMPU that contains Table 1 metal HAP (and is therefore subject to the CMAS rule), the facility would not be subject to the title V requirement.

Comment 2.6: One commenter (124) stated that the EPA should clarify how the title V requiremen t applies, particularly an “affected CMPU” and the “first substantive compliance

date” of a rule. Response 2.6: The EPA is unsure exactly what the commenter is asking. However, we note that an affected CMPU in the final CMAS rule is one that contains Table 1 HAP above the 0.1 percent/1.0 threshold at an area source. A source that did not obtain a federally enforceable limit on HAP emissions in advance of the first substantive compliance date of an otherwise applicable major source NESHAP would be subject to the major source NESHAP, not the CMAS

rule. The first substantive compliance date is generally considered the date on which a source must comply with substantive NESHAP requirements (e.g., emissions standards), and it does not include requirements such as initial notifications. If the commenter is unsure of applicability of a major source NESHAP, or whether the compliance date for a specific requirement constitutesDecember 6, 2012

6 the first substantive compliance date, it should contact the delegated state authority or th e appropriate EPA regional office.

Comment 2.7: One commenter (129) stated that there are numerous situations in which they were unsure as to whether or not the title V requirement would apply. Specifically:

1. The 2009 final rule limited the Title V requirement to sources that “installed a control device on a CMPU after November 15, 1990.” However, the reconsideration proposal referred to sources that “installed a federally

- enforceable control device on an affected CMPU by the first substantive compli ance date of an otherwise applicable
MACT standard.” How far back in time must be considered?

2. A synthetic area source originally installed a control device in 1951 to limit personnel exposure to a pollutant and for equipment protection purposes. The contro l device was not installed to reduce HAP emissions below major source levels. Does the purpose for installing the control device matter?

3. The reconsideration proposal used the phrase “installed a federally

- enforceable
control device.” Does the control devic e have to currently be federally

- enforceable or federally

- enforceable at the time it was installed?

4. A facility relies on both production limits and control devices to maintain synthetic area source status. Can the facility restructure their synthetic area source permit to rely solely on production limits or control devices on non

- affected CMPUs?

5. A facility currently has a control device for emissions from non

- affected CMPUs. Would the installation of a duct from a vent in a newly regulated CMPU to the

exist ing control device trigger the title V permit requirement?

6. A natural area source subject to the CMAS rule is required to install a control device on an affected CMPU as a result of compliance with the CMAS rule. Would the

installation of this control devic e trigger the title V permit requirement?

7. A natural area source subject to the CMAS rule installs a control device in the future because of a production increase that would trigger a MACT standard. Would the installation of this control device trigger the title V permit requirement?

8. A natural area source is not currently subject to the CMAS rule and will only be subject to the CMAS rule because a Table 1 HAP will be used as part of a production increase in the future. The facility installs a control device because the production increase would trigger a MACT standard. Would trigger the title V permit requirement? Response 2.7: As stated previously in this document and in the preamble to the final rule, the EPA has clarified the applicability of the title V p ermit requirement and believes that this revised language will answer many of the commenter’s questions. Specific answers to the commenter’s questions are below. The EPA notes, however, that these responses are based on the limited information provided by the commenter, and that sources should not consider these responses to be official applicability determinations or otherwise constitute final decisions by the EPA on the applicability of the title V requirement.

1. The installation date of the control device s is not a determining factor as to whether a title V permit is required. The installation of any federally enforceable control device on an affected CMPU in order to maintain synthetic area source status, regardless of age, would trigger the title V requi rement.
2. The purpose of the control device does not matter for the title V requirement.December 6, 2012

7 3. The control device must currently be federally

- enforceable and be necessary to maintain synthetic area source status. If a control device is necessary to maintain

area source status, and the requirement to use the control device is not federally

enforceable, the source may be a major source subject to a major source NESHAP (e.g., the HON or the MON).

4. If a facility restructures its permit in order to rely solely on produc tion limits or

control devices on non

- affected CMPUs, the facility would no longer be subject to the title V requirement after that point.

5. If the installation of the new duct from the affected CMPU is to an existing control device that is federally

- enforce able, and the control of the affected CMPU is necessary in order to maintain synthetic area source status, then it would trigger title V applicability. If controls are in place only on non

- affected CMPU, title V would not apply.

6. A natural area source is no t subject to the title V permit requirement, so long as it

continues to be a natural area source.

7. If the production increase would cause a natural area source to become a major source absent installation of a federally

- enforceable control device on the aff ected CMPU, then the installation of the control devise would trigger title V applicability. If controls are installed only on non

- affected CMPU, title V would not apply.

8. If a natural area source not subject to the CMAS rule begins using a Table 1 HAP in

c onjunction with a production increase, the CMPU would be an affected CMPU subject to the CMAS rule. The source could maintain area source status through the installation of federally

- enforceable controls, and, if the controls must be installed on the affec ted CMPU to maintain area source status, then the source would be subject to title V. However, the source could avoid title V permitting if it instead controlled emissions from a CMPU that is not subject to the CMAS rule.

Comment 2.8: One commenter (129) stated that if the EPA should choose to finalize the title V permit requirement, it must clarify whether the title V permit application must be submitted upon start

- up or within 12 months after plant startup. Response 2.8: The EPA intended in the proposed rule to propose to provide both new and existing sources with 12 months to submit their title V permit application after the CMAS rule amendments were finalized; however, the EPA agrees that the proposed rule revisions were ambiguous in regard to new CMAS sources (i.e., CMAS sources that began construction or reconstruction after the October 6, 2008, proposed rule was published in the Federal Register). The EPA has clarified in the final rule that all sources subject to the title V requirement, both

new and existing, will be provided 12 months to submit their title V permit application.



## 3.0 Requirements When Other Rules Overlap With the Final Rule

Comment 3.1: One commenter (133) recommended that the EPA eliminate the overlapping standards provision, as it may be difficult to determine which provisions are more stringent, which may lead to a disagreement between the source and the EPA or delegated authority. Response 3.1: It is not clear to the EPA how eliminating the overlapping provisions language would resol ve the issue, as a source would then be required to comply with eachDecember 6, 2012

8 overlapping rule independently. This provision is provided as an alternative to relieve compliance burden, and the EPA believes that it provides flexibility for a source in choosing how

t o comply with the standard. The alternative was intended as a means of reducing the compliance burden without diminishing the level of environmental protection provided by each rule. There is no obligation for the source to adopt this alternative approach, and as such, the EPA does not agree that there is any unreasonable burden associated with it. If sources subject to multiple NESHAP prefer to comply with each standard independently, the sources are not required to avail themselves of the overlapping requ irement provisions.



## 4.0 Requirement to Conduct Direct and Proximal Leak Inspections

Comment 4.1: One commenter (129) requested that other instrument based leak monitoring programs that have been demonstrated to be equivalent or better than the sensory detection methods should be allowed as well, as consistent with 40 CFR part 63, subpart R. The

comme nter was concerned that some equipment may not be adequately inspected without the use of an aerial lift, scaffold, or ladder, and notes that this type of monitoring is only required on an annual basis for the HON leak detection program. The commenter also suggested that the EPA add a provision that sensory inspections be conducted at distances as close as practical to equipment, but at distances that meet an individual site safety plan. Response 4.1: The EPA disagrees with the commenter that providing this alternative language is necessary, as an alternative means of compliance using Method 21 for leak detection inspections is already provided in the final rule. As noted in the reconsideration proposal, the EPA did not exempt difficult or unsafe to monitor equipment because “[s]ensory monitoring does not require intimate contact with each piece of equipment to be effective at identifying leaks.” See §63.11495(a)(3) of the revised final rule. Similarly, the EPA does not believe that it is necessary to add pro visions in the final rule to explicitly state that inspections be conducted as close as practical.

Comment 4.2: One commenter (128) requested that the EPA permit the use of pressure testing as a permissible alternative for leak detection, as this is a com monly used practice in batch operations. Response 4.2: The EPA disagrees with the commenter that pressure testing should be permitted as an alternative leak detection method. The EPA believes that a successful pressure test is not necessarily an indicator that all leaks were found in a CMPU, leaving open the possibility that leaks will be missed causing excess fugitive emissions that a facility would not be aware of until possibly an unsuccessful pressure test would identify that leak.



## 5.0 Requirement for Cove rs or Lids on Process Vessels

Comment 5.1: Four commenters (124, 128, 129, 133) supported the proposed revisions to the requirement for covers or lids on process vessels. Response 5.1: The EPA has finalized the proposed revisions to the requirement for

co vers or lids on process vessels.December 6, 2012

9 Comment 5.2: One commenter (128) who supported the revisions to the cover/lid requirement also requested additional changes to allow for operations in which repeated access to the process vessel is necessary. The commenter provided an example of a facility that has processes that require repeated access and had installed retractable tank covers on some of their process vessels. The commenter noted that the facility found the covers to be prone to breakdowns and failures, an d that they posed a significant safety concern (due to heavy moving equipment) and reduced the number of batches that could be produced (due to the constantly moving covers). The commenter recommended that mechanisms that capture or control operations simi lar to covers or lids be permitted, such as a push

- pull air circulation system. Response 5.2: The EPA disagrees with the commenter that providing for alternative methods of capture or control of emissions from process vessels is necessary in the final rule

. The EPA believes that situations in which it is impractical to install a cover or lid, as described by the commenter, are fairly rare. For those situations where it is difficult to use a cover or lid, the EPA believes that it is more appropriate to addre ss these situations in individual facility requests for alternative means of compliance, as described in §63.6(g), rather than in a generally applicable nationwide rulemaking.

Comment 5.3: One commenter (121) requested that process vessels should only be allowed to vent through a safety device when conditions require it to avoid unsafe conditions and that a definition of “safety device” would be appropriate, as consistent with the approach taken in the MON. The commenter believed that by including this pro vision, facilities would be precluded from avoiding regulations by routinely venting uncontrolled emissions, as the definition of safety device would prescribe under what conditions emissions could be emitted. Response 5.3: The EPA disagrees with the comme nter that a provision for venting through a safety device is appropriate in this rule. As finalized, process vessels are required to be equipped with a cover or lid at all times except when manual access is necessary, and facilities are generally not other wise permitted to vent uncontrolled emissions under the final rule. The EPA notes, however, that facilities are able to avail themselves of an affirmative defense for uncontrolled releases that are not permitted and occur as a result of a malfunction.

Com ment 5.4: One commenter (139) requested that the EPA exempt process vessels operating above 2000 °F from the requirement to install a cover or lid on process vessels in metal HAP service. The commenter (141) cited the high costs and potential safety concer ns of installing a cover on such a vessel. Response 5.4: The EPA disagrees with the commenter that it is necessary to exempt process vessels operating in excess of 2000 °F from the requirement to install a cover or lid for process vessels in metal HAP serv ice. We believe situations in which the process vessel would be operating at these high temperatures are fairly rare and unique, and we also believe that there a potential for increased emissions at higher temperatures. To the extent a source determines it is unsafe to use a cover or a lid, the EPA believes that it is more appropriate to address these situations in individual facility requests for alternative means of compliance, as described in §63.6(g), rather than through a broad nationwide exemption.



## 6.0 R equirement to Conduct Leak Inspections When Equipment Is

in HAP ServiceDecember 6, 2012

10 Comment 6.1: One commenter (129) suggests that sources should be allowed to postpone leak inspections until the next opportunity to do so when the unit is in organic HAP or

metal HAP service. Response 6.1: The EPA disagrees with the commenter that leak inspections should be allowed to be delayed until the next opportunity to conduct an inspection while the equipment is in organic HAP or metal HAP service. This would provide an indefini te period of time that equipment would be permitted to operate without having conducted a leak inspection. The EPA believes that it is more reasonable to allow sources to conduct inspections while the equipment is in VOC service, as discussed in the preamb le to the final rule, as this will provide them with more opportunities in which to conduct leak inspections, likely negating the need to delay an inspection.



## 7.0 Applicability of the Family of Materials Concept

All comments related to the Family of Materials concept are addressed in the preamble to

the final rule.December 6, 2012

11 

## 8.0 Startup, Shutdown, and Malfunction

Comment 8.1: Two commenters (128, 131) stated that the proposal to eliminate the startup, shutdown, and malfunction (SSM) provisions in the proposed s ubpart revisions is not based on an accurate reading of the decision of the D.C. Circuit in Sierra Club v. EPA . The commenters state that the EPA’s proposal for the standards to apply at all times is not consistent

with Sierra Club v. EPA , as the court did not hold that the EPA is prohibited from setting separate standards for periods of SSM that are different than the emission limits during normal operations but held that the standards for those periods must be developed according to the Clean Air Act (CAA ) section 112(d) generally achievable control technologies (GACT) process and must be proven to be achievable under CAA section 112(d). The commenters add that there is ample precedent for the EPA applying a different standard during SSM events, and such a standard could include a design, equipment, work practice, or operational standard under CAA section 112(h). Response 8.1: The EPA does not claim that the Sierra Club case constrains its authority to prescribe unique standards for periods of startup, shut down, or malfunction. The EPA‘s view is that the reasoning of the Sierra Club decision calls into question the legality of source

category

- specific startup and shutdown exemptions in rules promulgated pursuant to CAA section 112(d). The EPA also disagrees with the commenters contention that the Sierra Club decision addresses in any way the EPA‘s current approach to malfunctions. As explained in the preamble to the proposed and final rule, the EPA has determined that CAA section 112 does not require that emi ssions that occur during periods of malfunction be factored into development of

CAA section 112 standards. Consistent with Sierra Club , we have issued standards that apply at all times, including during malfunctions. The EPA’s rationale for this view is ex plained in detail in the preamble as well.

Comment 8.2: Three commenters (122, 124, 131) recommended that the EPA use its CAA 112(d)(5) authority to establish management practices as standards during period of

malfunction. One commenter (124) stated that the EPA did not consider malfunctions when established GACT for this source category, and as such is obligated to set a standard during periods of malfunction. The commenter believed that the EPA has the authority to establish work practice or operational standards during malfunctions under CAA section 112(h)(1), or separate management practices during malfunctions under CAA section 112(d)(5). The commenter stated that these approaches should be used in lieu of the affirmative defense. One commenter (131) s tated that the EPA offers little support for the assertion that it is reasonable to interpret section 112 as not requiring the EPA to account for malfunctions in setting emissions standards. The commenter stated that the EPA cannot exclude emissions from

m alfunctions, and then set emissions limits that even the best

- performing sources can only achieve part of the time. The commenter stated that due to the unplanned nature and variety of potential malfunctions, it would be difficult if not impossible for the EPA to gather data and set an emissions standard for periods of malfunction. Due to these difficulties, the commenters suggest that the EPA either prescribe operational requirements under the authority of CAA section 302(k), or promulgate a design, equipm ent, work practice or operational standard, or combination thereof under the authority of CAA section 112(h), where it is not feasible to set or

enforce an emission limit.December 6, 2012

12 Response 8.2: The EPA’s rationale for its approach to malfunctions is discussed in t he preambles to the proposed rule and this final action. As explained in those preambles, the EPA has determined that CAA section 112 does not require that emissions that occur during periods of malfunction be factored into development of CAA section 112 s tandards. There is nothing in CAA section 112 that directs the agency to consider malfunctions in determining the level “achieved” by sources when setting emission standards. Moreover, while the EPA accounts for variability in setting emissions standards c onsistent with the CAA section 112 case law, nothing in that case law requires the agency to consider malfunctions as part of that analysis. As the EPA further explained, accounting for malfunctions would be difficult, if not impossible, given the myriad d ifferent types of malfunctions that can occur across all sources in the category and given the difficulties associated with predicting or accounting for the frequency, degree, and duration of various malfunctions that might occur. The same concerns exist w hether the Agency is establishing numerical or work practice standards.

Comment 8.3: One commenter (128) recommended that, if appropriate, the EPA should include the same startup and shutdown standard for metal HAP emissions that exists for continuous pro cess vents. Response 8.3: As no additional data to support the commenter’s recommendation was received, the EPA has declined to establish a separate standard for metal HAP process vents during periods of startup and shutdown.

Comment 8.4: One commenter (1 28) recommended that the EPA add language to clarify that a malfunction in an air pollution control or monitoring equipment must be recorded only “if it caused or may have caused an applicable emission limitation to be exceeded.” Response 8.4: The EPA agre es with the commenter that records for malfunctions only need to be kept if they caused a failure to meet a standard. The EPA has clarified this recordkeeping requirement in the final rule.



## 9.0 Affirmative Defense

Comment 9.1: Two commenters (128, 131) state d that the affirmative defense provisions do not cure the EPA’s failure to set emission standards that are achievable during malfunction events and are not a substitute for setting achievable emissions standards for these periods. The

commenters stated tha t it is not clear what civil penalties the affirmative defense covers, and believed the affirmative defense should apply to civil penalties, civil administrative penalties, noncompliance penalties, enforcement actions by the EPA, states, or citizen

- suit pl aintiffs, and injunctive relief. The commenters, citing Sierra Club v. Otter Tail Power Co. , stated that, as a matter of law, injunctive relief may not be available in cases where a civil penalty cannot be imposed. The commenters also stated that sources s ubject to injunctive relief could be required to pay the citizen

- plaintiff’s attorneys fees even if the source is able to successfully assert the affirmative defense, which would not accomplish the EPA’s objective of providing relief for

violations that me et the conditions of the affirmative defense. Response 9.1: The affirmative defense applies to civil penalties, including civil administrative penalties and penalties under CAA section 120, but does not apply to injunctive relief or criminal penalties. The affirmative defense is available in any civil action to enforce the standards set forth in this rule, whether such action is brought by the EPA, a state or localDecember 6, 2012

13 authority or a citizen. The EPA agrees that in some cases, injunctive relief may not be

appro priate if all the criteria of the affirmative defense have been satisfied. In such cases, liability for attorney’s fees is not a real issue. However, some form of injunctive relief may be appropriate. The Sierra Club v. Otter Tail Power Co. case cited by c ommenters is not on point and does not undermine the EPA’s ability to limit the affirmative defense to penalty claims. The concurrent remedy doctrine provides that where a party's legal remedies are time

- barred a party's concurrent equitable claims general ly are barred. The affirmative defense is not a time

bar to civil penalties.

Comment 9.2: Two commenters (128, 131) stated that the EPA should reword the
“affirmative defense” so that it states that a source would not be deemed in violation of the

emissio ns standards for excess emissions or other deviations from the standards, associated with a malfunction event, unless the event, and the source’s response to the event, do not meet the criteria spelled out in the regulation. When worded this way, it would be more appropriate to call the “affirmative defense” something else, such as “alternative standard for SSM events.” The commenters also stated that if the EPA retains the affirmative defense, the agency must modify it substantially so that it does not require the source to prove its innocence. The commenters are concerned that the affirmative defense provisions imply the facility is guilty until proven innocent and put the burden of proof on the facility rather than the agency. Another commenter (126) b elieved that the EPA should establish a rebuttable presumption, rather than an affirmative defense, which would presume that any violation occurring during a malfunction not be the facility’s fault unless the EPA can prove otherwise. Response 9.2: The EPA does not agree with the commenters’ suggested that the term “affirmative defense” be revised. We maintain the term accurately reflects the provision. The

EPA also disagrees with comments that criticize the affirmative defense for shifting the burden of

pro of. The affirmative defense does not require a facility to prove its innocence rather than requiring an enforcement authority to prove a violation of the CAA, or otherwise change the burden of proof with respect to establishing a violation. The affirmative defense applies to penalties and thus is only utilized where a violation has been established. The burden of proof remains with the plaintiff in an enforcement action. See, e.g., 40 CFR 22.24. If a violation has

been established and a source wishes to ass ert the affirmative defense with respect to penalties, the source does bear the burden of establishing that the elements of the affirmative defense have

been met. This burden

- shifting is appropriate because the source is in a better position to

determine t he facts required to establish the defense. See , e.g., Arizona Pub. Serv. Co. v. EPA

, 562 F.3d 1116, 1120, 1129

- 30 (10 th Cir. 2009) (rejecting industry challenge to the EPA’s use of an affirmative defense to address excess emissions during malfunction even ts). The EPA does not agree that the affirmative defense should operate as the commenter suggests. It is the source, not the EPA (or other party taking enforcement action) that has the information relevant to assess whether a particular event qualifies as a malfunction that meets the affirmative defense. Furthermore, commenters’ suggested approach appears to be similar to the scheme that the court

vacated in the Sierra Club case, in that there would be no violation unless the enforcing party (the

EPA or a c itizen), established that the event in question was not a malfunction.

Comment 9.3: Four commenters (122, 126,128, 131) stated that the root cause analysis requirement may make the affirmative defense unavailable if the source is not able to determine

the primary cause of the malfunction. The commenters stated that it should be expected that inDecember 6, 2012

14 many causes the primary cause will not be ascertainable or that it will not be possible to identify a way to ensure the malfunction will not recur. Two commenters ( 122, 126) also stated that the requirement to keep properly signed operating logs is outdated since most records are now kept electronically. Response 9.3: The root cause analysis requirements specify that the purpose of the root cause analysis is “to dete rmine, correct, and eliminate the primary cause of the malfunction.” The root cause analysis itself does not necessarily require that the cause be determined, corrected or eliminated. However, in most cases, the EPA believes that a properly conducted root cause analysis

will have such results . The EPA does not assume that all malfunctions require an identical degree of investigation. The EPA expects that the effort required to do a root cause analysis will vary depending on the nature of the malfunction.

Wi th respect to the comment concerning operating logs, the EPA believes that log entries should be made contemporaneously, which does not mean, at the exact time that the engineers are taking actions to address the malfunction, but rather immediately thereaf ter. That way, more accurate records of the malfunction can be expected, as opposed to records reconstructed long after the malfunction. “Properly signed” means that the records should be signed by an engineer or other employee with knowledge of the situat ion, in a legible manner so that enforcement officials can tell who made the record and what their responsibilities were. The EPA generally accepts documents in electronic format, as long as the format is compatible with the requirements of the standards. For the affirmative defense provisions, the owner or operator of a facility experiencing an exceedance of its emission limit(s) during a malfunction must notify the Administrator by telephone or fax transmission of the exceedance. However, the written repo rts are required to demonstrate that the affirmative defense provisions have been met. In the case of signed logs, the EPA accepts electronically signed operating logs, where the format and method of submission meets the regulatory criteria and are compati ble with the EPA’s and the delegated authorities’ electronic submission systems. Any source submitting records electronically should exercise due diligence to assure receipt by the EPA and the delegated authority.

Comment 9.4: Two commenters (128, 131) st ated that some of the affirmative defense requirements are unreasonable, difficult to prove, and subject to varying interpretation and that the affirmative defense requirements need to be revised and streamlined to be of practical value. The commenters req uested that the term “infrequent,” and subjective phrases, such as “if at all possible,” “severe property damage,” and “all possible steps,” be removed from the regulatory text, as these terms could be subject to different interpretations by regulatory age ncies. Another commenter (124) stated that the affirmative defense criteria are overly burdensome, such as the requirement that a facility make repairs as “expeditiously as possible when the applicable emission limitations were being exceeded,” and/or unat tainable, such as the requirements that “[a]ll possible steps were taken to minimize the impact of the excess emissions on ambient air quality, the environment and human health” and that a facility minimize the frequency, amount, and duration of excess emi ssions “to the maximum extent practicable during periods of such emissions.” The commenter believed that many of the criteria use exaggerated or ambiguous language, making it unlikely that sources that experience malfunction events would

choose to avail th emselves of the affirmative defense. Another commenter (126) stated that if the EPA should choose to keep the affirmative defense, several revisions should be made. Specifically, the commenter recommended:

1. Replacing all references to “all” and “any” with “ preponderance of evidence.”December 6, 2012

15 2. Revising the definition of malfunction to be consistent with that of the General

Provisions.

3. Allowing the use of the affirmative defense in an action for injunctive relief. Response 9.4: The EPA believes the affirmative defense criteria are well

- defined and will assist the EPA and the courts in making reasoned determinations as to the establishment of affirmative defenses. The EPA does not believe the terms and conditions of the affirmative defense are overly subjective or extre me or need further qualification. The EPA and the courts have expertise and experience in evaluating and applying criteria such as those for the affirmative defense. Many of the conditions in the affirmative defense are modeled after the affirmative defens e in the EPA‘s state implementation plan (SIP) SSM policy, See, e.g., State Implementation Plans: Policy Regarding Excessive Emissions During Malfunctions, Startup, and Shutdown (September 20, 1999). Other conditions are modeled after a Federal Implementat ion Plan promulgated by the EPA. (40 CFR 50.1312) and recently affirmed by the U.S. Court of Appeals for the 9 th Circuit (Montana Sulphur & Chemical Co. v EPA, _666 F.3d 1174 (9 th Cir. 2012). The EPA‘s view is that use of consistent terms in establishing a ffirmative defense regulations and policies across various CAA programs will promote consistent implementation of those rules and policies. Several states have adopted the EPA‘s SIP SSM policy into their SIPs. We do not have any indication that parties to enforcement proceedings have had any significant difficulties applying the terms of these SIP affirmative defenses. As explained above, the EPA has determined that including affirmative defense provisions in NESHAP is appropriate

and reasonable.

Comment 9 .5: Two commenters (128, 131) believe the affirmative defense provisions should apply to the potential violation of emission limits during a startup or shutdown event as well as during malfunctions, if the EPA is to use such affirmative defense. Response 9.5: The EPA is promulgating the affirmative defense for malfunctions only, not for periods of startup and shutdown. As explained in the preamble, the EPA believes that malfunction events should be treated differently than periods of startup and shutdown, which are predictable and routine aspects of a source’s operations. In contrast, the EPA has determined that CAA section 112 does not require that emissions that occur during malfunctions be factored into development of CAA section 112 standards. Because s tartup and shutdown periods are part of a source’s normal operations, the same approach to compliance with, and enforcement of, applicable emissions standards during those periods should apply as otherwise applies during a source’s operations. Further, as explained above, periods of startup and shutdown

- but not malfunctions

- are taken into account when establishing section 112 emissions standards. For these reasons, the EPA does not believe it is appropriate to apply the affirmative defense provision to startup and shutdown periods. This does not, however, preclude a facility from asserting an affirmative defense for a malfunction event that occurs during a period of startup or

shutdown.

Comment 9.6: Four commenters (122, 126, 128, 131) requested that ma lfunction reporting be required on a semi

- annual basis to avoid problems with being able to submit a report within 45 days and potential issues with requesting and receiving an extension of the reporting deadline in a timely manner. Another commenter (129) supported allowing sources up to 45 days to submit an affirmative defense report, as well as the option to request a 30

- day extension.December 6, 2012

16 Response 9.6: The EPA agrees with the commenters and has revised the reporting requirement for asserting an affirmative defense in subpart VVVVVV to allow an owner or operator of the affected source seeking to assert an affirmative defense after experiencing a violation of its emission limit(s) or a violation of an emission standard during a malfunction to

submit a written report to the Administrator in the first periodic compliance, in a deviation report, or in an excess emission report otherwise required after the initial occurrence of the violation of the relevant standard, unless such report is due less than 45 days afte r the violation, in which case the affirmative defense report could be included in the next such required report.

Comment 9.7: Two commenters (128, 131) stated that the EPA estimate of $2,958 to

assert an affirmative defense for a malfunction is not credi ble, appears entirely arbitrary, and is remarkably low given the number of different demonstrations and root cause analysis that are required of a source.

The commenters stated it is demonstrated that the EPA believes the affirmative defense

will effectiv ely be unavailable to facilities, despite their proper design and operation because the EPA estimates only 1 or 2 instances of claims of an affirmative defense over a three

- year period for all the sources subject to the CMAS rule. Response 9.7: As part of an affirmative defense, we are requiring that an owner or operator conduct a root cause analysis and submit it with their semiannual compliance report to the Administrator, as documentation of having met the conditions and requirements for asserting an aff irmative defense. The EPA believes it has provided clear criteria within the affirmative defense provisions to support the development of an affirmative defense report. The EPA believes that these provisions will result in a minor administrative burden, bu t will result in sources analyzing their violation emissions to reduce or avoid those emissions in the future, which is an environmental benefit. The purpose of the analysis is to identify, correct, and eliminate or reduce the probability of the primary ca use of the malfunction in order to prevent another from occurring. A root cause analysis is not mandatory and is only required if a source seeks to assert an affirmative defense. However, such an analysis is beneficial in resolving or preventing

violations and excess emissions whether the source seeks to assert the affirmative defense or not. A root cause analysis is one example of what constitutes good air pollution control practices to

minimize emissions. Owners or operators will often employ such analyses as part of their normal operations, because any regulatory noncompliance event may impact the safety of workers, the environment, and/or the continued operation of the plant. Therefore, these events typically are, or should be, investigated and re solved by industry, whether or not their ultimate intention is to assert affirmative defense. While there may be a cost associated with conducting a root cause analysis, an owner or operator may eventually recoup the cost of the analysis by eliminating or reducing the likelihood of another similar failure. Avoiding such failures may increase the reliability of production, and avoid the cost of lost production time, material and equipment losses, and further compliance and safety violations. We (and the comm enters) acknowledge that the complexity of a malfunction event can vary. Our cost estimate is based on the assumption that the data gathering, recordkeeping and reporting that is already required by the applicable subparts will supply a portion of the info rmation required for the analysis to support an assertion of affirmative defense. As such we consider our estimate to be a reasonable estimate for the purpose of estimating the regulatory burden on affected sources for these rules.December 6, 2012

17 Comment 9.8: One commen ter (131) stated that the EPA has not justified changing conditions that apply to performance testing. The commenter contended that, where the 2009 final rule referenced the NESHAP General Provisions that required performance tests to be

conducted based on normal operating conditions of the affected source, the proposed rule specified that “operations during periods of startup, shutdown, and malfunction shall not constitute representative conditions for the purpose of a performance test,” which would allow the EPA to direct a source to conduct performance testing during abnormal operations, such as startups, shutdowns, or malfunctions. The commenter stated that the EPA cannot “amend” existing GACT standards in a way that can make the standards more stringent without first providing an adequate justification for departing from the EPA’s previous judgment about the appropriate conditions for performance testing. Response 9.8: The EPA notes that the revisions to the performance test requirements

does not directl

y require performance testing during SSM periods. However, as noted above, the EPA believes that it is important to collect data during all periods including SSM periods, as the rule requires when conducting any continuous monitoring. Sources who install c ontinuous emissions monitoring systems (CEMS) or other continuous monitoring devices are required to operate the monitoring equipment and collect data at all times the process unit is operating and at the intervals specified in the rule, except for periods of monitoring system malfunctions, repairs associated with monitoring system malfunctions, required monitoring system quality assurance or quality control activities and any scheduled maintenance as defined in the unit’s

site

- specific monitoring plan. Sou rces who conduct continuous monitoring will have HAP and other emissions data during SSM periods. Sources that opt to conduct periodic testing will not have data collected during SSM periods. A source that experiences a malfunction event may use any availa ble information to demonstrate that the source complied with the standard notwithstanding the malfunction.

Comment 9.9: Two commenters (128, 131) stated that the EPA has not justified why the addition of the new “general duty” language to the standards is necessary, and that the EPA should delete the new provisions. One commenter (131) also stated that the EPA lacks the authority to replace the previous reference to the General Provisions with somewhat different language in the individual subparts because these changes are not being proposed under 112(d)(6). One commenter (128) was also concerned about the use of the terms “at all times” and “minimizing emissions.” The commenter questioned how “at all times” would apply to a CMPU that was not operational an d whether “minimizing emissions” would require a facility to reduce emissions below the level required by the CMAS rule. The commenter also suggested that the EPA include the phrase “to the extent practicable” to clarify the extent of the actions required. Response 9.9: The EPA proposed to revise the CMAS rule in response to petitions for reconsideration, and the agency’s authority to propose changes is not limited to changes made pursuant to CAA section 112(d)(6) as the commenter states. The EPA, therefore , disagrees with the commenter that it lacks the authority to make the changes proposed and that it has not justified adding new General Duty language to the standards. The EPA explained in the proposal that we were eliminating the reference to 63.6(e)(1)( i) and replacing it with a new paragraph in 40 CFR 63.11495(d) that specifies the general duty to minimize emissions applies at all times (77 FR 4532). The EPA replaced the reference to 40 CFR 63.6(e)(1)(i) with newDecember 6, 2012

18 language to eliminate language that char acterizes what that duty entails during periods of SSM. With the elimination of the malfunction exemption, there is no need to differentiate between normal operations and malfunction events in describing the general duty. The EPA believes that

it is also u nnecessary to differentiate between normal operations and startup and shutdown events in describing the general duty. The general duty requirement language in 40 CFR 63.11495(d) also differs from 63.6(e)(1)(i) in that it does not include references to star tup, shutdown, and malfunction plans because such plans are not required. Regarding the use of the phrase “at all times,” the EPA notes that if a CMPU were not operational, then there would be no emissions emitted and so the commenter’s concerns are

unwarr anted. Regarding the use of the phrase “minimizing emissions,” this language does not require that a facility reduce its emissions below that required by the CMAS rule. Also, the EPA does not believe that the addition of the phrase “to the extent practicab le” to the General Duty is

necessary.

Comment 9.10: One commenter (128) stated that because the term "affected source" is not defined in the CMAS rule, the term "CMPU" should be substituted in the general duty and

affirmative defense. Response 9.10: The E

PA agrees with the commenter and has revised the final rule to reflect the use of “CMPU” instead of “affected source.”

Comment 9.11: One commenter (135) stated that the EPA should not add an affirmative defense to the rule on the basis that exposure to fo rmaldehyde can be dangerous and a potential risk to human health. The commenter does not believe that allowing a source to avail itself of an

affirmative defense is a beneficial revision of the rule. Response 9.11: The EPA initially notes that this rule do es not directly regulate the use of formaldehyde. The EPA also believes the commenter misunderstands the affirmative defense. The affirmative defense can only be employed to relieve a source of penalties. Injunctive relief, which would more directly affect future emissions, may still be sought if the EPA or another party can demonstrate that such relief is warranted to prevent future exceedances of the applicable standards.

. 

## 10.0 Metal HAP Process Vents

Comment 10.1: One commenter (128) supported the proposed clarification that a CMPU using only Table 1 metal HAP is not subject to any requirements for wastewater systems or heat exchange systems. Response 10.1: The EPA has finalized the proposed clarification.

Comment 10.2: One commenter (140) requested clarif ication on the monitoring requirements of metal HAP emissions from existing sources. Response 10.2: The EPA is clarifying that a CMPU required to achieve the emissions limits specified in Table 4 of the final rule must also conduct monitoring appropriate t o demonstrate continuous compliance, as required by §63.11496(f)(3)(i). Examples of monitoring sufficient to demonstrate continuous compliance may include a continuous monitoring system or periodic monitoring of parameters consistent with operating instruc tions of the control deviceDecember 6, 2012

19 supplier (whose parameters must be listed in the monitoring plan, pursuant to §63.11496(f)(3)(i)(D)).



## 11.0 Applicability

Comment 11.1: Four commenters (119, 121, 130, 133) supported the proposed

clarification as to whether an emission stream that contains a gaseous byproduct is a “process fluid” by creating a distinction between liquid streams and process vent streams. Response 11.1: The EPA has finalized the proposed clarification for liquid stream and process vent stream appl icability. The EPA notes, however, that it has replaced the term “process vent stream” with “continuous process vent or batch process vent” in order to further clarify its intent of what a “process vent stream” is.

Comment 11.2: Three commenters (119, 121 , 130) requested that the EPA add a definition of “process vent stream” in order to help clarify applicability determinations. Specifically, the commenters requested a definition that would clarify: (1) whether the 50 parts per million by volume (ppmv) thr eshold applies to controlled or uncontrolled emissions, and (2) where within the process the 50 ppmv threshold applies if emissions are routed through a device used for both controlling emissions and product recovery. Two commenters (119, 121) believed

tha t based on other language used in the CMAS rule, the 50 ppmv threshold would apply to emissions prior to entering a control device. One commenter (130) believed that the 50 ppmv threshold should apply to emissions upon exiting a recovery device. Response 1 1.2: The EPA notes that it has revised the thresholds for process vent streams to 0.1 percent by weight, in lieu of the proposed 50 ppmv threshold. In determining applicability for process vents, it was the EPA’s intent that the concentration of Table 1 HA P in the stream be evaluated at the point of discharge to the atmosphere, or prior to the point of entry into a control device if a control device is used. This approach is consistent with the EPA’s definition of “uncontrolled emissions,” which bases appli cability on emissions after the last recovery device but prior to any control device. It is also consistent with the definition of process vent in the HON, which is referenced by the CMAS rule in the definition of continuous process vent, as well

as the de finition of metal HAP process vent. In order to make this distinction clearer, the EPA has replaced the term “process vent stream” with “continuous process vent or batch process vent” in the applicability requirements for the final rule.

Comment 11.3: One commenter (130) questioned whether the EPA expects a facility to comply with provisions for liquid streams when the facility is subject to the CMAS rule due to process vent streams. The commenter believed that if a facility exceeds the applicability

thres hold for only process vents or only liquid streams, then it should only be subject to the applicable requirements for that respective emission point. Response 11.3: The EPA disagrees with the commenter that facilities subject to the CMAS rule due to proces s vent streams should be exempt from the requirements for liquid streams, and vice

- versa. The EPA believes that the management practices for liquid streams will not cause an unreasonable burden for facilities subject to the CMAS rule if a facility is only subject to the CMAS rule due to the presence of Table 1 HAP in a process vent, and vice

- versa. To the extent that there are facility

- specific issues that require clarification, sources should contact the applicable delegated state authority or the EPA.December 6, 2012

20 Co mment 11.4: One commenter (122) recommended that the applicability thresholds for chromium compounds should be subcategorized based on respective carcinogenicity. The commenter believed that this approach would be consistent with the EPA’s Toxic Release

In ventory, where hexavalent chromium compounds are subject to a 0.1 percent de minimis threshold and trivalent chromium compounds are subject to a 1.0 percent de minimis threshold. Response 11.4: The EPA agrees with the commenter that the applicability thres holds for chromium compounds should be different for trivalent and hexavalent chromium. In the original final rule, applicability for the 0.1/1.0 percent thresholds was based off of whether a compound was listed as a carcinogen by the Occupational Safety a nd Health Administration (OSHA). As specified in 29 CFR part 1910, subpart Z in OSHA’s Toxic and Hazardous Substances list, only hexavalent chromium is listed as a carcinogen. As such, the EPA has revised the final rule such that the 1.0 percent threshold applies to trivalent chromium and the 0.1 percent threshold applies to hexavalent chromium.

Comment 11.5: One commenter (122) requested that a mass

- based applicability threshold be established. The commenter recommended that a de minimis level of 1,000 lb /yr of Table 1 HAP should be adopted, as this would make applicability determinations more straightforward and would reduce burden without reducing environmental protection. Response 11.5: The EPA notes that a de minimis threshold was not an issue that was open for comment. As such, the EPA is declining to adopt a de minimis threshold for the final rule or otherwise respond to specific comments on a de minimis thresholds. See the preamble to the October 2009 final rule at 74 FR 56016

- 56018 and section 3.2 ( pp. 3

- 2

– 3

- 5) of the October 2009 response to comment document for additional rationale on the EPA’s decision not to adopt

a de minimis threshold.

Comment 11.6: One commenter (122) recommended that a concentration exclusion should be provided for equipme nt and vessels that contain organic HAP at concentrations of less than 5 percent by weight, which the commenter says would keep the CMAS rule (a GACT rule) no more stringent than a MACT standard. Response 11.6: The EPA notes that a concentration threshold was not an issue that was open for comment. In any case, the EPA disagrees with the commenter that equipment containing organic HAP at concentrations less than 5 percent by weight should be excluded, as

the EPA believes that the 0.1/1.0 percent applicability thresholds for liquid streams already in place are an appropriate applicability threshold, as those thresholds are the ones used by the EPA when determining which area sources of the Urban HAP should be list ed for regulation.

Comment 11.7: One commenter (122) requested that fugitive emissions applicability should be narrowed so that it is more consistent with other MACT and NSPS rules. Specifically, the commenter stated that the EPA should exempt equipment i n vacuum service, equipment in service less the 300 hours per calendar year, and equipment that is not in organic HAP service (defined to mean equipment that is in contact with or contains fluid that is at least 5 percent by weight organic HAP) from the le ak detection and repair (LDAR) program requirements. Response 11.7: The EPA notes that applicability of the LDAR program was not an issue that was open for comment. In any case, the EPA disagrees with the commenter that the above

described equipment should be exempt from equipment leak requirements. The EPA is requiringDecember 6, 2012

21 that sight, sound, or smell leak inspections be conducted, as opposed to a more stringent equipment

- based monitoring program (e.g., Method 21). For this reason, the EPA does not

believe that it is appropriate to exempt certain process equipment from the leak inspection requirements. In addition, the EPA believes that it would be more burdensome for sources to determine which equipment is in service while conducting sensory monitoring, as it w ould be difficult, if not impossible, to exclude such equipment from sensory inspections due to their presence near other affected equipment.

Comment 11.8: One commenter (129) supported the proposed revision to clarify which Table 1 HAP are carcinogens an d which are not. Response 11.8: The EPA has finalized the proposed clarification.

Comment 11.9: One commenter (123) supported the proposed revision to exempt lead oxide production at lead

- acid battery manufacturing facilities that are subject to 40 CFR su bpart

PPPPPP. Response 11.9: The EPA has finalized the proposed exemption for lead oxide production

at lead

- acid battery manufacturing facilities.



## 12.0 Compliance Date

Comment 12.1: One commenter (122) requested that, due to the ongoing reconsideration process, the required notification of compliance status (NOCS) report should not be required until 180 days after the compliance date of the rule (October 29, 2012), as consistent with 40 CFR 63.9(h), so that facilities have appropriate time to implement the applicable compliance requirements. Response 12.1: The EPA disagrees with the commenter that the deadline for the NOCS report should be extended for affected sources. As the EPA has extended the deadline for existing sources to comply with the CMAS rule by 90 days, we do not believe that any additional time beyond that is needed for facilities to submit their NOCS reports.



## 13.0 Definitions

Comment 13.1: Three commenters (128, 129, 133) supported the proposed revisions to the definition of “in organic HAP service.” Response 13.1: The EPA has finalized the proposed revisions to this definition.

Comment 13.2: Four commenters (127, 128, 129, 133) supported similar revisions as those propose d to “in organic HAP service” be made to the definition of “in metal HAP service.” Response 13.2: The EPA agrees with the commenters that similar revisions to the definition of “in metal HAP service” should be made such that it is similar to the definition of “in organic HAP service.” Similar to equipment in organic HAP service, equipment in metal HAP service should also be considered to no longer be in service after it has been emptied and cleaned to the extent practicable. As such, the EPA has made this r evision in the final rule

amendments.December 6, 2012

22 Comment 13.3: One commenter (133) supported the proposed revisions to the definition of “chemical manufacturing process.” Response 13.3: The EPA has finalized the proposed revisions to this definition.

Comment 13.4: One commenter (128) requested that the EPA clarify that filter presses and other similar equipment (i.e., conveyors and extruders) are not process vessels, as described in the preamble to the proposed rule revisions, and that the EPA refer to process vesse ls in such a manner consistent with the definition of “process vessel” in the final rule. Response 13.4: The EPA agrees with the commenter that equipment such as filter presses, conveyors, and extruders are not process vessels.

Comment 13.5: Two commenter s (118, 132) requested that the difference between a recovery device and a control device be clarified by adding a definition for each. Response 13.5: The EPA notes that a definition for “recovery device” already exists in
the CMAS rule. However, in order to help clarify the distinction between recovery and control devices, the EPA has incorporated by reference the definition of control device from the HON, which states that recovery devices are not considered control devices.

Comment 13.6: One commenter ( 122) requested that a definition be added for the following terms: dense gas system, intermediate change to test method, major change to test method, minor change to test method, point of determination, uncontrolled organic HAP emissions. The commenter sug gests definitions for each, and notes that while not all of the terms are used in the CMAS rule, definitions are needed when referencing other subparts from the

CMAS rule. Response 13.6: The EPA disagrees with the commenter that a definition is needed for dense gas system, as the definition contained in subpart GGG (which is referenced by the CMAS rule) would apply since there is no definition in the CMAS rule to override it. The EPA disagrees with the commenter that definitions are needed for intermediate change to test method, major change to test method, and minor change to test method, as all of these terms are already referenced in §63.11503 to their respective definitions in §63.90. The EPA agrees with the commenter that a definition of point of determ ination is needed due to specific references needed for the definition to be applicable to the final rule, and has added this definition in the final revised rule. The EPA disagrees with the commenter that a separate definition for uncontrolled organic HAP emissions is necessary, as the EPA had proposed a definition for uncontrolled emissions. However, the EPA has revised this definition in the final rule to be more explicit as to how it relates to organic HAP and metal HAP emissions.



## 14.0 Other/Technical Corre ctions

Comment 14.1: One commenter (131) stated that the EPA does not have the authority to reconsider previously issued GACT standards. The commenter stated that the EPA cannot reconsider aspects of previously issued GACT standards unrelated to “development in practices,

pro cesses, and control technologies,” under CAA section 112(d)(6), including the proposed SSM provisions. The commenter also stated that the EPA cannot change its mind about what standards are required to comply with CAA section 112(d)(5) nor revisit and redo previously issued NESHAP. The commenter stated that even if the EPA had the authority to revise existing GACTDecember 6, 2012

23 standards, it would need to justify the new standards in terms of the criteria for standards under CAA section 112(d), which is has not done in t he proposed rule. The commenter added that even if the EPA had the authority to change the existing GACT standards, it could not reasonably make the revised standards effective immediately, noting that CAA section 112(i) allows for a compliance deadline of up to three years. Response 14.1: The EPA disagrees with the commenter that it does not have the authority to revisit previously issued NESHAP. In Medical Waste Institute v. EPA, 645 F. 3d
420, 425

- 27 (D.C. Cir. 2011), the D.C. Circuit held that the EPA m ay permissibly amend improper MACT determinations, including amendments to improperly promulgated floor determinations, using its authority under section 112 (d) (2) and (3). We maintain that similar authority exists for standards issued pursuant to sectio n 112(d)(5). The D.C. Circuit’s decision in Portland Cement Ass’n v. EPA, 665 F.3d 177, 189 (D.C. Cir. 2011), confirmed that the EPA is not constrained by section 112 (d)(6) and it may reassess its standards more often, including revising existing floors i

f need be. Slip op. p. 17. The commenters are thus incorrect that section 112 (d)(6) provides the exclusive authority to revise existing NESHAP. The EPA also maintains that it has authority to reconsider rules and the commenter has not demonstrated that su ch authority does not exist. Consequently, the EPA maintains that it is not barred from reconsidering GACT standards.

Comment 14.2: One commenter (122) identified several incorrect or missing references in the final rule that should be corrected or added, including: the addition of references to §63.996(c)(2)(ii) and §63.998(c)(1)(ii)(E) in §63.11496(g)(5); replacing the reference to §63.982(c)(2) with 63.982(c) in Item 1.a of Table 3; removing the reference to §63.11495 in Item 1.b of Table 5; revising It em 1.d of Table 5 to reference the correct citations in subpart VVVVVV for requirements for offsite cleaning or reloading facilities; and adding a missing applicability entry in Table 9 for §63.9(i). Response 14.2: The EPA has corrected the identified erro rs in the final rule.

Comment 14.3: One commenter (122) suggested several revisions to improve clarity of the final rule, including: adding an example of how to correct emission contributions for calculation of the TRE value of combined streams; adding a new Item 3 of Table 3 to clarify the requirements for continuous process vents with a TRE > 1.0 but ≤ 4.0; adding a paragraph in §63.11496(e) to clarify that the requirements of §63.2450(j) for CEMS do not apply; clarifying that the halogenated vent strea m requirements also apply to affected storage vessels in §63.11497; clarifying that a facility may designate a stream as being halogenated rather than calculating the mass emission rate of halogen atoms; clarifying the applicability of §63.8(c)(4) and §63. 8(g)(5) in Table 9; clarifying in §63.11496(g)(2) that a design evaluation may be used to determine initial compliance for sources complying with an outlet concentration emission limit; and revising Item 1.a.i of Table 8 to clarify that §63.104(b)(1) does not apply. Response 14.3: The EPA has made these revisions in the final rule.

Comment 14.4: One commenter (122) suggested that the EPA clarify that the initial process condenser initial demonstration requirements of subpart GGG only apply in certain

circu mstances. Response 14.4: The EPA disagrees with the commenter’s suggested revisions to the process condenser initial demonstration requirement. The requirements of §63.1257(b)(8) (asDecember 6, 2012

24 referenced by §63.11496(g)(8) via §63.2460(c)) provide the circumstances under which a performance test must be performed for process condensers and further clarification is not required.

Comment 14.5: One commenter (122) suggested that the EPA allow facilities to measure the caustic strength of the scrubber effluent from halo gen scrubbers in lieu of the pH. Response 14.5: The EPA agrees with the commenter’s suggested alternative and has revised the final rule language to allow for measurement of the caustic strength in lieu of the pH. The EPA notes, however, that this option i s only being made for the measurement of the caustic strength of the scrubber effluent, and not for the intake or recirculation tank. This alternative is also only being permitted due to the CMAS rule requiring a daily measurement of the pH, as opposed to other rules that may require continuous monitoring of the scrubber, in which case measurement of the caustic strength may not be appropriate.

Comment 14.6: One commenter (128) stated that the EPA should remove a reference in §63.11498(a)(2) to Item 2.c in Table 6, as this item does not appear in the final rule nor the proposed rule. Response 14.6: The EPA has corrected this error in the final rule.

Comment 14.7: One commenter (121) requested that the definition of “batch process

vent” be amended to includ e vents from batch operations, not just intermittent flows from continuous operations. Response 14.7: The EPA notes that while the definition of “batch process vent” does not preclude streams from batch operations from being considered a batch process vent, the definition could be clearer. As such, the EPA agrees with the commenter and has revised the def inition to specify that it also includes flows from batch operations.

Comment 14.8: One commenter (121) requested that definitions of “batch operation” and “continuous operation” be added. Response 14.8: The EPA agrees with the commenter that definitions of batch operation and continuous operation are necessary, as these terms are used in several locations in the final rule. As such, the EPA has revised the final rule to incorporate the definition of “batch operation” and “continuous operation” from the M ON.

Comment 14.9: One commenter (129) believed that the definition of “continuous process vent” is confusing since it substitutes words and citations from the HON, and recommended that the entire definition be incorporated into the CMAS rule. Response 14. 9: The EPA disagrees with the commenter that the entire definition of “continuous process vent” should be incorporated into the CMAS rule. The EPA believes that the references and substitutions to the definition of “process vent” in the HON are straightfor

ward and generally understood by the regulated community, as this approach is also

used in the MON.

Comment 14.10: One commenter (128) requested that the EPA allow for hard piping of wastewater streams to a point of transfer to onsite hazardous waste treatment, not just to offsite

hazardous waste treatment.December 6, 2012

25 Response 14.10: The EPA agrees with the commenter that it is appropriate to allow for facilities to hard pipe wastewater streams to a point of transfer to onsite hazardous waste treatment, and has made this revision in the final rule amendments.

Comment 14.11: One commenter (128) requested that the definition of ha zardous waste treatment be revised to clarify that incinerators, process heaters, and boilers that comply with 40 CFR 63, subpart EEE qualify as hazardous waste treatment units. The commenter also requested that this change also be made for 40 CFR part 63, subpart SS, which includes a similar reference

as the CMAS rule. Response 14.11: The EPA agrees with the commenter that incinerators, process heats, and boilers that comply with subpart EEE qualify as hazardous waste treatment units, and has

the revised t he final rule to reflect this. Regarding the request for a revision to subpart SS, the EPA notes that this rulemaking only encompasses subpart VVVVVV, and so a revision to subpart SS would be inappropriate at this time.

Comment 14.12: One commenter (133) requested an interpretation regarding the exemption for research and development facilities. Response 14.12: The EPA notes that this was not an issue that was open for comment and was addressed in section 3.5.3 (pp. 3

- 11) of the October 2009 response to co mment document. The EPA further addressed this issue in the preamble to this final action.