September 16

, 2014



# National Emission Standards for Hazardous Air

Pollutant Emissions: Generic Maximum Achievable Control Technology Standards; and Manufacture of

Amino/Phenolic Resins

Summary of Public Comments and Responses on Proposed Rule (7 9 FR 1 676 , January 9, 201 4 )

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

## (This page is intentionally lef t blank)iii 

## FOREWORD

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

Emissions: Generic Maximum Achievable Control Technology Standa rds; and Manufacture of

Amino/Phenolic Resins .” The EPA Docket contains all comment letters submitted and are available for viewing at the EPA Docket Center Reading Room, or electronically through http://www.re gulations.gov by searching Docket ID No. EPA

- HQ

- OAR

- 201 2

- 0133 by docket

number.

This document provides a summary of the public comments entered into the docket regarding specific issues and topics related to the development of the proposed amendments to the subject rules and the EPA’s responses to those comments. Within each comment summary, the EPA provides in parentheses one or more Docket ID numbers for commenters who raised particular issues. However, the list of commenter ID numbers is not meant to b e 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 preamble 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.iv 

## TABLE OF CONTENTS

1.0 Background

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

2.0 Risk

- Related Assessment and Standards

................................ ................................ ............. 3

2.1 Risk As sessment Data and Methodology

................................ ................................ ...... 3

2.2 Consideration of Risks from Entire Facilities, Industrial Clusters, and Other Sources

in Risk Assessment

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

2.3 Consideration of Demographics in Risk Assessment

................................ .................. 14

2.4 Additional Standards to Address Risks

................................ ................................ ........ 16

3.0 Startup, Shutdown, and Malfunction Exemption/Affirmative Defense Provisions

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

3.1 Startup, Shutdown, and Malfunction Exemption

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

3.2 Affirmative Defense Provisions

................................ ................................ ................... 23

4.0 Electronic Reporting Requirements

................................ ................................ ................... 27

5.0 Open Ended Line Provisions

................................ ................................ ............................. 29

6.0 Pressure Relief Device Provisions

................................ ................................ ..................... 32

7.0 Source Category and Subpart

- Specific Comments

................................ ............................ 39

7.1 Source Category Specific Comments

– Acrylic and Modacrylic Fibers Production

... 39

7.2 Source Category Specific Comments

– Amino/Phenolic Resins Production

.............. 40

7.3 Source Category Specific Comments

– Polycarbonate Production

............................. 41

7.4 Subpart Specific Comments

– Subpart YY (GMACT)

................................ ............... 41

8.0 Other Comments

................................ ................................ ................................ ................ 44v 

## ACRONYMS AND ABBREVIATIONS

Acronym/

Abbreviation Definition
Act or CAA Clean Air Act

ACA American Coatings Association

ACC American Chemistry Council

AEGL Acute Exposure Guideline Level

AMF Acrylic and Modacrylic Fibe rs Production

AMOS Ample Margin of Safety

APR Amino/Phenolic Resins Production

BBDR Biologically

- Based Dose

- Response

Cal OEHHA California Office of Environmental Health Hazard Assessment

CDX Central Data Exchange

CEDRI Compliance and Emissions Data R eporting Interface

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act

CFR Code of Federal Regulations

CHIEF Clearinghouse for Emission Inventories and Emissions Factors

CIIT Chemical Industry Institute of Toxicology

CRWI Coal ition for Responsible Waste Incineration

EJ Environmental Justice

EO Executive Order

EPA U.S. Environmental Protection Agency

EPCRA Emergency Planning and Community Right

- to

- Know Act

ERPG Emergency Response Planning Guideline

ERT Electronic Reporting Tool

FR Federal Register

GMACT Generic MAC T

HAP Hazardous Air Pollutants

HON National Emission Standards for Organic Hazardous Air Pollutants From the

Synthetic Organic Chemical Manufacturing Industry HQ Hazard Quotient

ICR Information Collection Re quest

IRIS Integrated Risk Information System

LDAR Leak Detection and Repair

MACT Maximum Achievable Control Technology NAAQS National Ambient Air Quality Standards

NACAA National Association of Clean Air Agencies

NAS National Academy of Sciences

NA TA National Air Toxics Assessment

NEI National Emissions Inventory

NESHAP National Emission Standards for Hazardous Air Pollutants

NOCS Notice of Compliance Statusvi

NODA Notice of Data Availability

OECA Office of Enforcement and Compliance Assurance

P B Persistent and Bioaccumulative

PC Polycarbonate Production

POM Polycyclic Organic Matter

ppm Parts Per Million

PRA Paperwork Reduction Act

PRD Pressure Rel i e f Device

REL Reference Exposure Level

RFA Regulatory Flexibility Act

RfC Reference Concen tration

RfD Reference Dose

RO Responsible Official RQ Reportable Quantity

RTR Risk and Technology Review

SAB Science Advisory Board

SARA Superfund Amendments and Reauthorization Act SCAQMD South Coast Air Quality Management District

SOCMA Society o f Chemical Manufacturers and Affiliates

SOCMI Synthetic Organic Chemical Manufacturing Industry

SSM Startup, Shutdown, and Malfunction

TOSHI Target Organ

- Specific Hazard Index

VOC Volatile Organic Compoundvii 

## (This page is intentiona lly left blank)1



## 1.0 Background

On January 9, 201 4 (7 9 FR 1 676 ), the U.S. Environmental Protection Agency (EPA) proposed to revise two National Emission Standards for Hazardous Air Pollutants (NESHAP) applicable to three industrial source categories: Acrylic and Modacrylic Fibers Production (AMF), Polycarbonate Production (PC)

, and Amino/Phenolic Resins Production (APR) , under the authority of section 112 of the Clean Air Act (CAA). This document presents summaries of

the comments that were submitted in response to this action and our responses to those comments. The comments to which we are responding were submitted in 1 6 letters from industry representatives, governmental entities

, and environmental advocacy groups during the public comment period. A list of the commenters, their affiliations, and the EPA docket number assigned to their correspondence is presented in Table 1

- 1.2

TABLE 1

- 1. LIST OF COMMENTERS ON PRO POSED NATIONAL EMISSION

STANDARDS FOR HAZARDOUS AIR POLLU TANTS

Docket

Number ab Commenter Affiliation

29 Russell A. Wozniak The Dow Chemical Company (Dow)

30 Jackson Morrill American Chemistry Council (ACC) Formaldehyde Panel

31 Lorraine Krupa Gershman American Chemistry Council (ACC)

32 Melvin E. Keener Coa lition for Responsible Waste Incineration (CRWI)

33 Alphonse McMahon Sabic Innovative Plastics US LLC

34 David Darling and

Javaneh Nekoomaram American Coatings Association (ACA)

35 G. Vinson Hellwig and Robert H. Colby National Association of Clean Air Agencies (NACAA) Air Toxics Committee

36 Emma Cheuse and Jim

Pew Sierra Club and California Communities Against

Toxics

37 Barry H. Christensen Occidental Chemical Corporation (OxyChem)

38 Leslie Sue Ritts National Environmental Development

Associations Clean Air Project (NEDA/CAP)

39 Russell Frye SSM Coalition

40 Matthew Todd Residual Risk Coalition (R2C)

41 Michael J. Manning Cytec Industries Inc.

42 Matthew Todd American Petroleum Institute (API)

45 Dana M. Schnobrich 3M

46 Traylor Champion Georg ia Pacific, LLC (GP)

a Document ID identifies comments found in Docket No. EPA

- HQ

- OAR

- 2012

- 0133 by document number.

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

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

- HQ

- OAR

- 2012

- 0133

- XXXX, where “XXXX” represents the unique 4

- digit document docket number). The unique document docket numbers presented in this table and document represent that unique docket number without the preceding 0s. For example, docket number EPA

- HQ

- OAR

- 2012

- 0133

- 00 30 is presented as 30 in this table and

within the text of this document.

The following sections provide a summary of the comments received on the proposed

standards for the AMF, APR

, and PC source categories , as well as the EPA’s responses to these comments. For the purpose of orderly presentation, the comments have been categorized under the following topics:

Section 2: Risk

- Related Assessment and Standards

Section 3 : Startup, S hutdown, and Malfunction Exemption/Affirmative Defense

Provisions

Section 4 : Electronic Reporting Requirements

Section 5: Open

- Ended Line Provisions

Section 6 : Pressure Re lief Device Provisions

Section 7 : Source Category and Subpart

- Specific Comments

Secti on 8 : Other Comments3



## 2.0 Risk

- Related Assessment and Standards

2.1 Risk Assessment Data and Methodology

Comment 2.1.1: Commenter 35 is pleased to see the EPA placing increasing reliance on CalEPA Chronic Reference Exposure Level (REL) acute exposure thres hold values and recommends continuing the use of RELs over Acute Ex posure Guideline Level (AEGL) and Emergency Response Planning Guideline (ERPG) values, which the commenter does not feel are appropriate for assessing daily human exposure scenarios. Respon se 2.1.1: As discussed in the preamble to the proposed rule (7 9 FR 1 686

), the EPA considers various acute health effect reference values, including the California acute REL, and AEGL and ERPG values, in assessing the potential for risks from acute exposure s.

Comment 2.1.2: Commenter 30 urge s the EPA to use the Chemical Industry Institute of Toxicology (CIIT) cancer dose

- response value for formaldehyde established in 1999 rather than the 1991 Integrated Risk Information System (IRIS) dose

- response value, in keeping with the Information Quality Act and Executive Order 13563, which states that the regulatory system
must “be based on the best available science.” Response 2.1.2: In 2004, the EPA determined that the CIIT cancer dose

- response value for formaldehy de (5.5 x 10

- 9 per μg/ m 3 ) was based on better science than the IRIS cancer dose

response value (1.3 x 10

- 5 per μg/ m 3 ), and we switched from using the IRIS value to the CIIT value in risk assessments supporting regulatory actions. Subsequent research publi shed by the EPA suggested that the CIIT model was not appropriate and, in 2010, the EPA returned to using the 1991 IRIS value. The EPA has been working on revising the forma ldehyde IRIS assessment

and the National Academy of Science ( NAS ) completed its rev iew of the EPA’s dr aft assessment in April of 2011. 1 The EPA will follow the NAS Report recommendations and will present results obtained by implementing a biologically based dose

- response ( BBDR ) model for formaldehyde. The EPA will compare these estimates with those currently presented in the External Review draft of the assessment and will discuss their strengths and weaknesses. As recommended by the NAS committee, appropriate sensitivity and uncertainty analyses will be an integral component of implement ing the BBDR model. In the interim, we will present findings using the 1991 IRIS value as a primary estimate and the EPA may also consider other information as the science

evolves. We note that, except in the case of the APR source category, formaldehyde w as not a primary driver of the risks for these source categories, and risks due to formaldehyde emissions did not change our decisions about acceptability and ampl e margin of safety of the risks associated with any of these source categories, or about our technology reviews for them. Therefore, in this rulemaking the choice between using the IRIS value or the CIIT value makes no difference in the regulatory outcome.

Comment 2.1. 3 : Commenter 36 states that the EPA cannot assume that hazardous air pollutants (HAP) with no peer

- reviewed reference values for cancer or non

- cancer effects have zero risk. The commenter states that the EPA must select health protective values based on the

1 http://www.nap.edu/catalog.php?record_id=131424

information it has or, at a minimum, add an uncertainty factor to the risk es timates. The commenter also requests that the EPA clearly state which HAP emitted by these source categories have no health reference values. Response 2.1.3 : This issue was addressed by the EPA’s SAB in its May 10, 2010 (EPA

SAB

- 10

- 007) response to the E PA Administrator; http://yo semite.epa.gov/sab/sabproduct.nsf/4AB3966E263D943A8525771F00668381/$File/EPA

- SAB

- 10

- 007

- unsigned.pdf . In that response, the SAB Panel recommended that, for HAP that do

not have dose

- response values from the EPA’s hierarchy list, the EPA should consider and utilize, as appropriate, additional sources for such values that have undergone adequate and rigorous scientific peer revie w. The SAB panel further recommended that the inclusion of additional sources of dose

- response valu es into the EPA’s hierarchy should be adequately documented in a transparent manner in any residual risk assessment case study. We agree with this approach and have considered other sources of dose

- response data when conducting our

risk determinations unde r RTR. However, in some instances no sources of information beyond the EPA’s hierarchy are available.

The EPA notes that we did state which HAP currently have no reference value. In the risk assessment document, there is a table for each source category th at lists all the HAP emitted by the source category, and indicates whether there is an available cancer, chronic noncancer,

and/or acute dose

- response value. For those HAP currently with no reference value, we did not find any additional dose

- response valu es from other sources.

Comment 2.1.4 : Commenter 36 claims the EPA lags behind the best available science to

address the real

- world health risk for the individual most exposed to the current source categories and must apply this science in the rulemaking u nder CAA section 112(f )(2). In particular, the

commenter believes the EPA should follow the recommendations of the NAS and SAB on the key issues that affect the most

- exposed and most vulnerable populations, especially children and environmental justice ( EJ ) communities. The c ommenter states the EPA must consider the science and update its risk assessment in, at least, each of the following ways before finalizing

the rule:

 Account for individual

- level vulnerability in this risk assessment by better incorpora ting the vulnerability of children, early

- life exposures, and the developing

fetus into risk assessment methods:

 Account for increased susceptibility by using California Office of Environmental Health Hazard Assessment (Cal OEHHA) Cancer Guidelines (Age

- De pendent Adjustment Factors) for all carcinogens , not just known mutagens and include pre

natal susceptibility

.

 For chronic non

- cancer risk, consult and apply child

- specific reference values (such

as the Cal OEHHA values ), where available.

 If child

- specifi c reference values are unavailable, consult science on early exposure impacts, and use an additional default factor of at least 10X. Response 2.1. 4 : We disagree with the general comment that the EPA should adopt the

Cal OEHHA child

-

protective scientific ap

proach on cancer. The EPA has a hierarchy of appropriate health benchmark values and in general, this hierarchy places greater weight on the EPA derived health benchmarks than those from other agencies (see http://www.epa.g ov/ttn/atw/nata1 999/99pdfs/healtheffectsinfo.pdf ) . Notably, this hierarchy favoring EPA benchmarks (when they exist) over a ll others has been endorsed by the SAB.5

Further, the EPA is currently evaluating whether it is appropriate to use the CalEPA child

specific reference doses, and we note that because there are currently no such values for HAP

i nhalation, their current util ity would be limited to persistent and bioaccumulative (PB)

- HAP, which may be associated with non

- negligible ingestion exposures. Th at is, before using these

child

- specific reference doses (RfDs), the EPA would need to evaluate whether they have been

appro priately derived. We also disagree with the comment that the risk assessment for these source categories does not consider the groups that may be most at

- risk in its risk assessments (e.g., pregnant women). When the EPA derives exposure reference concentra tions and unit risk estimates for metal HAP, it also considers the most sensitive populations identified in the available literature, and importantly, these are the values used in our risk assessments (see US EPA. (2002). A review of the reference dose and reference concentration processes. EPA/630/P

- 02/002F. Risk Assessment Forum, Washington

, DC. Available online a t http://www.epa.gov/raf/publications/pdfs/rfd

- final.pdf ). With respect t o maternal exposure in utero specifically, we are unaware of literature that would allow for a robust characterization of

risk du ring this stage of development. We acknowledge that population subgroups, including children, may have a potential for

risk tha t is greater than the general population due to greater relative exposure and/or greater susceptibility to the toxicant. As explained in previous actions, including the final synthetic organic chemical manufacturing industry (SOCMI) hazardous organic NESHA P (HON) RTR (71

FR 76610

- 76611), the assessments we undertake to estimate risk account for this potential vulnerability. With respect to exposure, the risk assessments we perform implicitly account for this greater potential for exposure by assuming lifeti me exposure, in which populations are conservatively presumed to be exposed to airborne concentrations at their residence continuously, 24 hours per day for a full lifetime, including childhood. With regard to children‘s potentially greater susceptibility to non

- cancer toxicants, the assessments rely on EPA (or comparable) hazard identification and dose

- response values which have been developed to be protective for all subgroups of the general population, including children. For example, a review of the chr onic reference value process concluded that the EPA’s reference concentration (RfC) derivation processes adequately considered potential susceptibility of different subgroups with specific consideration of children, such that the resultant RfC values perta in to the full human population including sensitive subgroups, “a phrase which is inclusive of childhood.” With respect to cancer, the EPA uses the age

- dependent adjustment factor approach referred to by the commenter, but limits the use of those factors o nly to carcinogenic pollutants that are known to act via mutagenic mode of action, in contrast to the OEHHA approach, which uses them across the board for all carcinogens regardless of mode of

action (MOA) . In lieu of chemical

- specific data on which age or life

- stage specific risk estimates or potencies can be determined, default age dependent adjustment factors can be applied when assessing cancer risk for early

- life exposures to chemicals which cause cancer through a mutagenic MOA . At the present time, th ere have been no peer

- reviewed assessments that explicitly make a determination that any of the chemicals emitted by the source categories considered in this action cause cancer through a mutagenic mode of action. However, the

estimated risks must also be considered in the context of the full set of assumptions used for this risk assessment. For example, we used a health

- protective assumption of a 70

- year exposure duration in our risk estimates; however, using the national average residency time of 12 years would reduce the estimate of risk by roughly a factor of 6. Our unit risk estimates for HAP are6

considered a plausible upper

- bound estimate; actual potency is likely to be lower and some of which could be as low as zero. After considering these and other factors, we continue to consider the risks from emissions after application of the revisions to the Maximum Achievable Control Technology (MACT) standards for these source categories to provide an ample margin of safety (consistent with the Benzene NESHAP framework). The EPA disagrees with the commenter’s statement that the EPA should use California EPA’s child specific

- reference doses 2 in order to address the potential for early

- life susceptibility. The EPA methods for assessing hazard and dose

- response re lationships for HAPs and developing RfCs and cancer risk estimates, as noted above, specifically addr ess the potential for early

- life susceptibility. Whenever data indicate increased susceptibility of a developmental lifestage or of a population group, tho se data are factored into the analysis. When data are inadequate to understand the effects of a speci fic pollutant on sensitive subpopulations, which for some pollutants may include children, the EPA’s risk assessment methods take that into

account to ensu re that resulting assessments address the possibility that such subpopulations might be more or less sensitive. Further, in the RTR risk assessments performed using the agency’s preferred dose

- response values, exposure is characterized as occurring all day and every day over a lifetime, rather than only during specific periods of time during childhood.

Comment 2.1.5 : Commenter 35 recommends that the EPA consider risk based on potential or allowable emissions because emissions and associated impacts could i ncrease over time, and analyses based on actual emissions may underestimate residual risk. The commenter notes that the thresholds for major source status were based on maximum potential

- to

- emit, and permits are issued based on potential emissions. Further , the commenter argues that limiting the scope of risk assessments to actual emissions would be inconsistent with the applicability sections of the MACT standards. While acknowledging that the EPA used allowable emissions in parts of the rulemaking, the co mmenter encourages the EPA to use allowable emissions also

for acute health risks.
In contrast, commenter 40 states that the EPA cannot lawfully use the MACT allowable

emissions in risk assessments and residual risk determinations because the EPA has alle gedly failed to provide any reasoned explanation why risk assessments based on actual emissions are inadequate. The commenter states that the language of section 112 requires that the EPA report on the actual health effects for people living in the vicinit y of affected sources, which the commenter claims clearly signals that Congress expected the EPA to focus on actual risk and not hypothetical risk in implementing the requirements of section 112(f). In addition, because the risk methodology already reflect s numerous conservative assumptions, the commenter asserts it makes no sense to add another layer of conservatism and the EPA has not provided any data to indicate analyses based on actual emissions result in negative bias. Response 2.1 .5 : Consistent with previous risk assessments, the EPA considers both allowable and actual emissions in assessing chronic exposure and risk under section 112(f)(2). (See, e.g., National Emission Standards for Coke Oven Batteries (70 FR 19998

- 19999, April 15,

2 We note that California EPA’s use of these numerical values, which do not exist for inhalation exposures, is

limited to the context of risk as sessment at proposed or existing California school sites and does not even extend to their Air Hot Spots Risk Assessment program. Further the guidance for the California EPA school site assessment program specifies the use of California OEHHA or U.S. EPA I RIS values in the absence of the school site risk

assessment child

- specific values (Cal OEHHA, 2004

- http://www.oehha.ca.gov/public_info/public/kids/pdf/SchoolscreenFinal.pdf ).7

2005); proposed a nd final National Emission Standards for Organic Hazardous Air Pollutants from the Synthetic Organic Chemical Manufacturing Industry (71 FR 34428, June 14, 2006, and 71 FR 76603, December 21, 2006). This approach is both reasonable and consistent with the flexibility inherent in the Benzene NESHAP framework for assessing ample margin of safety. As a general matter, modeling allowable emission levels is inherently reasonable since this reflects the maximum level sources could emit and still comply with natio nal emission standards. But it is also reasonable to consider actual emissions, where such data are available, in both steps of the risk analysis. See National Emission Standards for Coke Oven Batteries, 70 FR 19992, 19998 (April 15, 2005). We disagree wit h commenter 35 ’s claim that the additional consideration of actual emissions conflicts with either the statutory major source definition that is based on potential to emit, or with applicability thresholds in MACT standards that are tied to major

source st atus. Those thresholds still have the same full effect for determining the applicability of section 112 standards that they had before we conducted our residual risk assessments. Moreover, our risk assessments necessarily included information regarding sou rces with potential

– not necessarily actual

– emissions at major source levels. We also note that our use of allowable emission levels in the risk assessments in this rulemaking did not result in revising the previously established standards due to risk c oncerns. Therefore, our consideration of allowable emissions in the risk assessments did not result in regulatory decisions that affect any facilities , and commenter 40 ’s objections to our use of allowable emissions are moot.

Comment 2.1.6 : Commenter 35 s tate s that the use of the census block centroid dilutes the effect of sources’ emissions, as the maximum point of impact can be far from the centroid and may be at or near a facility’s property line, and suggested that the risks for a source category

be ba sed on the risks to the maximally exposed individual. Response 2.1. 6 : As we have explained in previous RTRs, such as the SOCMI HON RTR (71 FR 76603, December 21, 2006), the EPA believes that, in a national

- scale assessment of lifetime inhalation exposures and health risks from facilities in a source category, it is appropriate to id entify exposure locations where it may be reasonably expected that an individual will spend a majority of his or her lifetime. Further, in determining chronic risks, the

EPA bel ieves that it is appropriate to use census block information on where people ac tually reside, rather than points on a fence

- line, to locate the estimation of exposures and risks to individuals living near such facilities. If a population did indeed live ju st outside of the fenceline of a facility, then it would result in a census block near the fenceline. Census blocks are the finest resolution available as part of the nationwide population data (as developed by the US Census Bureau); each is typically comp rised of approximately 40 people or about 10 households. In EPA risk assessments, the geographic centroid of each census block containing at least one person is used to represent the location where all the people in that

census block live. The census block centroid with the highest estimated exposure then becomes the location of maximum exposure, and the entire population of that census block experiences the maximum individual risk. In some cases, because actual residence locations may be closer to or farth er from facility emission points, this may result in an overestimate or underestimate of the actual annual concentrations (although there is no systematic bias for average levels). Given the relatively small dimensions of census blocks in densely populated areas, there is little uncertainty introduced by using the census block centroids in lieu of actual residence locations. There is the potential for more uncertainty when census blocks are larger, although there is still8

no bias on average. 3 Th e EPA conclu des that the most appropriate locations at which to estimate chronic exposures and risks are the census block centroids because: 1) census blocks are the finest resolution available in the national census data, 2) facility fencelines do not typically

repre sent locations where chronic exposures are likely because people do not typica lly live near the fenceline, and 3) there is no bias introduced into the estimate of the MIR by using census

block centroid locations.

Comment 2.1. 7 : Commenter 36 states that al l emissions data the EPA currently has are primarily estimates subject to significant error in the estimation calculations. To improve the available data, the commenter states that the EPA needs to require remote sensing and continuous monitoring to track and measure emissions, with technologies such as differential absorption light detection and ranging, solar occultation flux, CEREX UV Hound, and Accusense. The commenter also states that in addition or as an alternative, the EPA should require continuous emissions monitoring or performance tests every year, at a minimum, as it has done for other source categories. Response 2.1.7: The emissions data for the risk assessments in the proposed rules were derived from the National Emissions Inventory ( NEI ) as w ell as data provided by industry. The sources of the data are documented in the docket. As stated in the EPA’s documentation on the 2005 NEI ( http://www.epa.gov/ttn/chief/net/2005_nei_point .pdf ), “[t]he 2005 NEI is a composite of emission estimates generated by state and local regulatory agencies, tribes, industry, and EPA. Because the estimates originated from a variety of sources and estimation methods, as well as for differing purposes, they will in turn vary in quality, pollutants included, level of detail, and geographic coverage. However, this compilation of emissions estimates represents the best available information to date.” More generally, we note that the 2005 NEI for HAP is grea tly improved since the first NEI compilation using 1996 data, and that it is sufficiently accurate and complete and constitutes the best information the EPA has to use in our analysis. We have worked diligently with state and local agencies and tribes to i mprove emission inventories over the years, and we have instituted a number of quality assurance (QA) measures to improve data received from state and local agencies since 1996. Documentation for the 2005 NEI point source emissions inventory is available o n the EPA's Clearinghouse for Inventories and Emissions Factors (CHIEF) website, http://www.epa.gov/ttn/chief/net/2005inventory.html . Quality assurance and augmentation procedures used for the 2005 NEI point sources are contained in the report, EI Quality Assurance and Data Augmentation for Point Sources, posted at: http://www.epa.gov/ttn/chief/net/2002inventory.html . The 2 005 NEI data have been reviewed extensively internally and externally during a 9

- month effort as part of the development of the 2005 National Air Toxics Assessment (NATA). As part of the 2005 NATA review, more than one million records for HAP were revised. Updated test data and emission point information were received during the public comment period that addressed inaccuracies in the data. For these source categories, the EPA‘s review included an evaluation of facilities contained in the source

category, t he emissions units expected to be included for the processes in the source categories, coordinates and stack parameters, and the HAP compounds and emission levels typically seen. The NEI data were also reviewed by industry trade groups, including ACC and t he Society of Chemical Manufacturers and Affiliates (SOCMA), as well as several state air agencies, and the

3 There is no bias because a residence has an equal likelihood of being farthe r from a source, compared to the block centroid’s distance, as it does being nearer to a source.9

EPA revised the NEI data where we concluded comments from this review supported such adjustment. Section II. C of the January 9, 2014 , proposal pream ble (7 9 FR 1684 ) set forth a detailed explanation of the review that the EPA performed on the emissions data for the source categories subject to this final rule. A s part of the proposal, we also made the data sets available for review using a RTR data rev iew tool in the docket and solicited comments on the data sets. The RTR review of the proposal data sets act as another external third party review mechanism in addition to the external 2005 NATA review of the RTR data sets. Several opportunities have

been provided to review the data used in the current proposal. Through enhanced NEI QA procedures, 2005 NATA review, industry, state, and NACAA review, public comment on proposal files, source category

- specific engineering reviews, and modeling, improvements t o the data files have been made. We believe the data sets used in this rulemaking are sufficiently accurate and complete and constitute the best information the EPA has concerning the emissions and risk from these source categories for conducting RTRs.

Co mment 2.1. 8 : Commenter 36 states that the EPA should analyze risk including

emissions that may occur above the existing MACT standards, considering malfunctions and violations. The commenter states that the EPA must assess public health risk based on the

l ikelihood of such events and suggests that the EPA develop and apply a factor to the risk results

based on available malfunction and violation data. Response 2.1. 8 : We disagree with the commenter that emissions that exceed standards and are violations, whe ther or not they are caused by malfunction events, should be considered as part of the risk analysis for purposes of determining the sufficiency of pre

- existing standards, particularly when we are revising the standards to eliminate any excused periods of non

compliance during upset periods. The purpose of the risk review under section 112(f)(2)(A) is to

evaluate whether the emission limits

-- the “standards promulgated pursuant to subsection (d)

, ”

not the non

- compliance with those standards

-- should be m ade more stringent to reduce the risk posed after compliance with the underlying MACT standard. To the extent that a source is violating the underlying MACT standard, no tightening of the emission standard under the

residual risk rule will avoid or militat e against such violations. In other words, a source that is violating the emission standard promulgated under section 112(d) would not be any more likely to be able to avoid such violations and comply with a differe nt presumably more stringent standard pro mulgated under section 112(f). Such events are violations and subject to enforcement by the EPA, the states or citizens, and an action for injunctive relief is the most effective means to address violations whether or not they are caused by malfunctions if an emissions event poses a significant health or environmental risk. Furthermore, the conservative estimates built into the acute risk assessment are sufficient

to gauge worst

- case potential acute health effects. The conservative estimates built in to the

assessment include worst

- case meteorology, emissions at ten (or two) times the maximum peak emission rate from all point sources simultaneously, and the sum of the maximum impact of each emission source, regardless of receptor location. Thus, even if we w ere to consider emissions that are in violation of the standard, we do not believe that they would result in any different level of control than we are promulgating here.

Comment 2.1. 9 : Commenter 36 states that the EPA has not used a high enough

emissions factor to account for acute risks. The EPA used an emissions factor of 2 for equipment

leaks and 10 for all other emissions sou r ces and has not demonstrated that th e s e factor s are high10

enough to assess t rue acute risks , considering that a facility could e mit 100 times more than its usual emissions if it usually controls 99% of emissions . The commenter also states that equipment leaks can continue indefinitely and with no limit on emissions quantities

. Response 2.1. 9 : The acute risk assessment methodology u ses a tiered, iterative approach that begins with an assessment of an approximation of a worst

- case exposure. To this end, the assumption that peak 1

- hour emissions are equal to 10 (or 2 for equipment leaks ) times the average 1

- hour emissions rate is only one of the worst

- case assumptions that we made in our acute health risk screening analysis. Other worst

- case assumptions included:

 For facilities with multiple emission points, peak 1

- hour emissions were assumed to occur at all emission points at the same time.

 For facilities with multiple emission points, 1

- hour concentrations at each receptor were assumed to be the sum of the maximum concentrations due to each emission point, regardless of whether those maximum concentrations occurred during the same hour

.

 Worst

- case meteorology (from one year of local meteorology) was assumed to occur at the same time the peak emission rates occur. The recommended EPA local

- scale dispersion model, AERMOD, is used for simulating atmospheric dispersion.

 A person was assumed to be located downwind at the point of maximum impact during

this same 1

- hour period, but no nearer to the source than 100 meters.

 The maximum impact was compared to multiple short

- term health benchmarks for the chemical being assessed to determine if a p ossible acute health risk might exist. Based on industry

- specific information, we determined that a refined emissions mul tiplier of 2, rather than a multiplier of 10, better represents the peak hourly emission rates for equipment leaks . Refer to a separate memorandum in the docket ( Emissions Data and Acute Risk Factor Used in Residual Risk Modeling; Acrylic and Modacrylic Fibers, Amino/Phenolic Resins, and Polycarbonate Production ) for a detailed description of how the refined emissions multipliers were dev eloped for the source categories. Regarding the failure of a control device, this would constitute a violation of the emission standard. The acute risk emissions factor is designed to account for fluctuations in emissions for facilities complying with the standards, not for facilities in non

- compliance. Therefore, it would be inappropriate to use the emissions factor suggested by the commenter for purposes of determining whether the MACT standards’ current requirements are in need of revision under section 112(f)(2).

Comment 2.1.10 : Commenter 36 state s that the EPA failed to perform an adequate multipathway risk assessment. One reason the commenter states the assessment is inadequate is that it does not account for all the PB pollutants. The commenter asser ts that the EPA’s choice to restrict the multipathway screening assessment to only HAP that bioaccumulate is not supported by the 2003 Risk Assessment Guidance because it ignores other HAP that persist and accumulate

in soils . In addition, the commenter st ates that the EPA should include all metals in the multipathway risk assessment, as recommended by California’s OEHHA and also recommends that naphthalene, a polycyclic aromatic hydrocarbon (PAH), be considered a polycyclic organic matter (POM), which is l isted as a PB

- HAP. In addition, the commenter notes that the EPA did not assess all exposure routes, did not use the information from the multipathway analysis in the overall risk analysis, and did not add the multipathway risk found to the inhalation risk . The commenter asserts that the EPA may not assume that risks under the multipathway threshold are not significant enough to require a full analysis. The commenter opines that the EPA should update the incidental soil ingestion factors it uses in its mult ipathway risk assessments to fully11

account for the greater multipathway exposure and risk for children. Response 2.1.1 0 : We disagree that the multipathway assessment is inadequate due to restrictions in the pollutants included in the screening assessment. In the Air Toxics Risk Assessment Reference Library, we developed the current PB

- HAP list considering all of the available information on persistence and bioaccumulation ( see http://www2.epa.gov/fera/air

toxics

- risk

- assessment

- reference

- library

- volumes

- 1

- 3 ), specifically Volume 1 Appendix D). (The Air Toxics Risk Assessment Refer ence Library provides information on the fundamental principles of risk

- based assessment for air toxics and how to apply those principles in different settings (e.g., facility

- speci fic) as well as strategies for reducing risk at the local level.) This list considered HAP identified as PB

- HAP by other EPA Program Offices (e.g., the Great Waters Program), as well as information from the PBT profiler (see http://www.pbtprofiler.net/ ). This list was peer

- reviewed by the SAB and found to be acceptable, and therefore we consider it to be reasonable for use in the RTR program. Based on these sources and the limited available information on the persistence and bioaccumulation of other HAP, we do not believe that the potential for multipathway risk from other HAP rises to the level of the PB

- HAP currently on the

list. Regarding naphthalene, it is listed separately from POM in the Act, and it is no t included on the current list of PB

- HAP. The properties of naphthalene do not indicate that it is persistent or

bioaccumulative. Naphthalene evaporates easily. In the air, moisture and sunlight make it break down, often within a day. Naphthalene in water is destroyed by bacteria or evaporates into the air. Most naphthalene will be gone from water in rivers or lakes within two weeks. Naphthalene binds weakly to soils and sediments. In soil, some microorganisms break down naphthalene. When near the surface o

f the soil, naphthalene will evaporate into air. Microorganisms present in the soil will break down most of the naphthalene in one to three months. Naphthalene does not accumulate in the flesh of animals and fish

. 4

We did not combine the inhalation and mu ltipathway risk assessment results for each pollutant because it is inappropriate to do so. The multipathway risk assessment conducted for proposal was a screening

- level assessment (i.e., Tier 1). It used highly conservative assumptions designed to ensure that facilities with results below the screening threshold values did not have the potential for multipathway impacts of concern. The screening scenario is a hypothetical scenario. It is inappropriate to combine the results of a refined inhalation assessme nt, which produces a quantitative result, with a screening

- level multipathway assessment, which produces a “yes/no” result. In situations where we have previously summed the inhalation and multipathway assessment results (e.g., secondary lead smelters), it was for two refined assessments, and still serves as an overestimate of potential risks given that it is highly unlikely that the same receptor has the maximum results in both assessments. We further note that we generally draw no bright lines of acceptab ility regarding cancer or noncancer risks from source category HAP emissions, and that it is always important to consider the specific uncertainties of the emissions and health effects information regarding the source category in question when deciding exa ctly what level of cancer and noncancer risk should be considered acceptable. In addition, the source category

- specific decision of what constitutes an acceptable level of risk should be a holistic one; that is, it should simultaneously consider all potent ial health impacts

-- chronic and acute, cancer and noncancer, and multipathway,

-- along with their uncertainties, when determining the acceptable level of source

4 US Agency for Toxic Substances and Disease Registry. 200 5. Toxicological Profile for Naphthalene, 1

- Methylnaphthalene, and 2

- Methylnaphthalene. http://www.at sdr.cdc.gov/ToxProfiles/tp.asp?id=240&tid=43#bookmark08

.12

category risk. In other words, we look at the risk numbers within the context of uncertainty associated with emissions, health benchmark values and, in the case of cancer and noncancer risks, the health effect associated with exposure. The Benzene NESHAP decision framework of 1989 acknowledged this; in today’s world, such flexibility is even more imperative, because new information relevant to the question of risk acceptability is being developed all the time, and the accuracy and uncertainty of each piece of information must be considered in a weight

- of

evidence approach for each decision. This relevant body of information is growing fast (and it will continue to grow faster and faster), necessitating a flexible weight

- of

- evidence approach that acknowledges both complexity and uncertainty in the simplest and most transparent way possible. While t his challenge is formidable, it is nonetheless the goal of the EPA’s RTR

decision

- making, and it is the goal of the risk assessment to provide the information to support

the decision

- making process. Regarding incidental soil contamination, the EPA has esti mated risks from both direct and indirect pathways. Direct routes of exposure include direct ingestion of soil and exposure through dermal contact. However, because it has been demonstrated in past analyses that exposure levels associated with dermal conta ct are but a small fraction of exposure levels associated with ingestion and inhalation pathways, dermal exposures were not assessed for these source categories.

Comment 2.1

. 11 : Commenter 36 states that the EPA must account for the health risk

from underp erforming flares in its assessment of risk. Where the EPA does not have enough information to assess the actual performance and emissions from flares, default values should be

used. Response 2.1.11: The EPA disagrees with the commenter that it has failed t o adequately assess the risk from flares for these source categories. The commenter has failed to provide the EPA with evidence that the flares in these source categories (if any exist) are underperforming, nor do they provide data on how such a factor sho uld be developed. Lacking that information, we do not believe it is appropriate to apply a default factor to flares. The EPA has already determined, based on risk assessments conducted for the subject source categories, that

additional control to achieve a n “ample margin of safety” for the AMF, PC, and APR source categories is not needed, as the previously promulgated MACT standards already achieve the level of protection required by section 112(f)(2). See Docket ID No. EPA

- HQ

- OAR

- 2012

- 0133 for documentatio n of the risk assessments.



### 2.2 Consideration of Risks from Entire Facilities, Industrial Clusters, and

Other Sources in Risk Assessment

Comment 2.2.1: Commenter 36 states that the EPA should assess the cumulative burden of exposures to multiple pollutant s and sources via multiple pathways. To do this, the commenter suggests that the EPA aggregate inhalation and non

- inhalation

- based cancer risks ; include the interaction of multiple pollutants ; and account for exposure to multiple emissions sources

includin g other emissions sources at the facilities and from other sources of toxic air pollutants in

the area

. The commenter states that until the EPA has a specific mechanism for estimating total

exposures, use of a default factor of at least 10X should be incor porated in the risk assessments.
In contrast, commenter 40 states that the EPA does not have authority to consider risks from multiple emissions sources ( referring to facility

- wide risks) because the CAA section 112(f)(2)(A) allegedly requires residual ri sk determinations to be conducted on a category

- by

-13

category basis and risk assessments to be focused exclusively on emissions from sources in the category or subcategory. Response 2.2.1: We have combined risk assessment results to the extent that it is

ap propriate to do so. We do consider the effect of mixtures of carcinogens. We do not use a

target organ

- specific hazard index ( TOSHI ) approach for acute noncancer like we do for chronic noncancer. We also do not combine the results of our inhalation and mul tipathway

assessments. As described in the risk assessment report (available in the docket for this action), we do not sum results of the acute noncancer inhalation assessment to create a combined acute risk number that would represent the total acute risk for all pollutants that act in a similar way on the same organ system or systems (similar to the chronic TOSHI). As noted in previous responses,

the worst

- case acute screen is already a conservative scenario. That is, the acute screening

scenario assumes worst

- case meteorology, peak emissions for all emission points occurring

con currently and an individual being located at the site of maximum concentration for an hour. Thus, as noted in section 2.7.2 of the Draft Residual Risk Assessment for the Acrylic an d Modacrylic Fibers Production Source Categor y (Docket Item No. EPA

- HQ

- OAR

- 201 2

- 0 13 3

- 00 2 1), “because of the conservative nature of the acute inhalation screening and the variable nature of emissions and potential exposures, acute impacts were screened on a n individual pollutant basis, not using the TOSHI approach.” We did not combine the inhalation and multipathway risk assessment results for each pollutant because it is inappropriate to do so. The multipathway risk assessment conducted for proposal was a s creening

- level assessment (i.e., Tier 1). It used highly conservative assumptions designed to ensure that facilities with results below the screening threshold values did not have the potential for multipathway impacts of concern. The screening scenario is a hypothetical scenario, and due to the theoretical construct of the screening model, exceedances of the thresholds are not directly translatable into estimates of risk or hazard quotients for these facilities. In situations where we have previously summe d the inhalation and multipathway assessment results (e.g., secondary lead smelters), it was for two refined assessments, and still serves as a conservative overestimate of potential risks given that it is highly unlikely that the same receptor has the max imum results in both assessments. The EPA conducted an assessment of the cumulative cancer risks from emitted carcinogens and the cumulative noncancer hazard indices from all emitted non

- carcinogens affecting the same target organ system for both the sour ce category emissions and the facility

wide emissions. This assessment excludes background contributions because technical limitations in the data sets would be insufficient to conduct a meaningful analysis. While the incorporation of additional background concentrations from the environment in our risk assessments (including those from mobile sources and other industrial and area sources) could be technically challenging, they are neither mandated nor barred from our analysis. In developing the decision fr amework in the Benzene NESHAP currently used for making residual risk decisions, the EPA rejected approaches that would have mandated consideration of background levels of pollution in assessing the acceptability of risk, concluding that comparison of acce ptable risk should not be associated with levels in polluted urban air (54 FR 38044, 38061, September 14, 1989). Background levels (including natural background) are not barred from the EPA‘s ample margin of safety (AMOS) analysis, and the EPA may consider them, as appropriate and as available, along with other factors, such as cost and technical feasibility, in the second step of its section 112(f) analysis.14

We disagree with the comment that we failed to consider or account for cumulative risk.

The EPA mod eled whole

-

facility risks for both chronic cancer and non

- cancer impacts to understand the risk contribution of the sources within these MACT categories. The individual cancer risks for each source category were aggregated for all carcinogens. In assessing noncancer hazard from chronic exposures for pollutants that have similar modes of action or (where this information is absent) that affect the same target organ, we aggregated the hazard quotients (HQ). This process creates, for each target organ, a TOSHI , defined as the sum of hazard quotients for individual HAP that affect the same organ or organ system. All TOSHI calculations presented here were based exclusively on effects occurring at the “critical dose” (i.e., the lowest dose that produces adverse he alth effects). Whole facility risks were estimated utilizing the 2005 NEI, with updated facility

- wide and source category data files developed by the EPA through emission data updates from industry, states, and NACAA. We also disagree
with the commenter’s assertion that additional quantitative assessment of risks from sources outside the source category is required under the statute. The statute requires the EPA to provide the quantitative risk information necessary to inform RTR regulatory decisions, and t o this end, the EPA conducts a comprehensive assessment of the risks associated with exposure to the HAP emitted by the source category and supplements that with additional information that is available about other possible concurrent and relevant risks.



### 2.3 Consideration of Demographics in Risk Assessment

Comment 2.3.1: Commenter 35 commends the EPA for considering environmental justice ( EJ ) issues in th e proposal issues in this proposal. However, the commenter suggests the

EPA rule writers work with the EPA’s Office of Environmental Justice to dev elop specific criteria and guidance on how to interpret and apply the outcomes of EJ analyses in the rulemaking process . The commenter also specifically suggests that the EPA use a 5

- kilometer

radius rather than 3

- mile radius in its demographic analyses ; that the EPA conduct the demographic analysis for all people projected to experience risk greater than 1

- in

- 1 million for cancer or an HQ above one

, consistent with the approach used for the Hard and Decorative

C hromium Electroplating and Chromium Anodizing Tanks source category; that the analysis be conducted using maximum allowable emissions ; and that the EPA update the poverty statistics used in the analyses to include 2010 census data. Response 2.3.1: The comm enter is correct that we performed the demographic analyses for the AMF, PC, and APR source categories differently than we did for the October 2010 proposed RTR for the chrome source categories. We performed the demographic analyses for the

chrome source c ategories using two approaches as examples of how such analyses might be developed, and invited public comment on the approaches used and the interpretations made from the results. In the first approach, we focused the analysis on the total populations res iding within 5 km of each facility, regardless of their estimated risks, and examined the distributions across various demographic groups within those 5 km circles. That analysis was a “proximity” analysis in that it considered only the distance from the e mission sources to surrounding populations, and not the estimated risks to those populations In the second approach, we focused the analysis on the populations within 5 km of any facility estimated to have exposures to HAP which result in cancer risks of 1

- in

- 1 million or

greater or non

- cancer hazard indices of 1 or greater. We examined the distributions of those risks across various demographic groups. In each approach, we compared the percentages of particular demographic groups to the total number of peo ple in those demographic groups15

nationwide. We stated in the proposed rule for the chrome source categories that in future rules we planned to extend the analyses to cover the entire modeled domain for a facility (50 km radius) to capture all individuals w ith risks above 1

- in

- 1 million or greater or non

- cancer hazard indices of 1 or greater. We also stated that generally we have found that using a 5 km radius in the analysis will capture more than 90 percent of the individuals with cancer risks

above 1

- in

- 1 million. In the February 2012 supplemental proposal for the RTR for the chrome source categories, our demographic analyses included populations within 50 km of each source (including those very near the sources) with risks of 1

- in

- 1 million or greater or non

- cancer hazard indices of 1 or greater (77 FR 6628, Feb. 8, 2012). We did not include analyses using a 5 km radius in that supplemental proposal nor in the RTR proposal for the AMF, PC, and APR source categories. We believe that, where a risk assessment has been performed, it is more informative to consider the demographics of all populations (including those beyond 5 km) with elevated risks than to limit the demographics analysis to populations located within 5 km of a facility. Where risk assessment ha s been performed, these populations are identified, and the source parameters (like the low release height mentioned by the commenter) are accounted for. As discussed above, we have found that most exposure locations with the highest estimated risks

are wi thin 5 km of a facility, so extending the radius to 50 km has little impact on an analysis based on risks, but makes more sense because 50 km corresponds to the risk modeling radius and includes all populations with elevated risk estimates.

We note that we are working with the Office of Environmental Justice in an ongoing effort to develop new tools for considering environmental justice in rulemakings. While we intend to use the 2010 census data in future analyses, we do not believe that a rerun of our

anal ysis using the 2010 census data would yield results that would change our overall conclusions regarding EJ impacts. Therefore, we have decided not to rerun the EJ analy sis using

the 2010 Census data.

Comment 2.3.2: Commenter 40 states that CAA section 112 (f)(2)(A) expressly instructs

the EPA to impose additional emissions controls if needed to provide an ample margin of safety to protect public health. The commenter says that the term “public health” cannot reasonably be interpreted to include consideratio n of environmental justice in the context of section 112(f), and therefore the EPA’s proposal to consider demographic analyses in conducting risk reviews is not a proper exercise of the EPA’s authority. Although “public health” is not defined in sect ion 11 2 or in the EPA’s 40 CFR p art 63 regulations, the commenter states that the Supreme Court
observed in the context of the EPA’s National Ambient Air Quality Standards ( NAAQS ) Program that the primary definition of the term should be applied, and that is pub lic health means “the health of the public.” The commenter notes that i n the NAAQS program, the EPA interprets the term “public health” to include consideration of impacts on the population as a

whole but also considers sensitive subpopulations identified by their health

- based sensitivities, recognizing that the objective is to protect the group rather than any particular individual in the group. These sensitive subpopulations are identified independent of their demographic

classifications. The commenter sa ys that the EPA’s proposal to introduce demographic analyses to the determination of acceptable risk suggests that risk to some individuals is deemed more acceptable than risk to other individuals, and the commenter asserts that this type of political judg ment has no place in a scientific evaluation of risk to public health.16

Response 2.3.2: In this rulemaking, the EPA developed comparative analyses of the demographics of the populations within the vicinity of the facilities in these source categories as

par t of the risk assessment for each source category; the analyses did not change the results or conclusions in the assessments. As stated in the Benzene NESHAP, in determining the need for residual risk standards, we strive to limit to no higher than approxi mately 1

- in

- 10 thousand (100

- in

- 1 million) the estimated cancer risk that a person living near a plant would have if he or she were exposed to the maximum pollutant concentrations for 70 years and, in the ample margin of safety decision, to protect the gre atest number of persons possible to an individual lifetime risk level of no higher than approximately 1

- in

- 1 million. These considerations are made for all people regardless of racial or socioeconomic status. However, in determining whether to require addi tional standards under section 112(f), these levels are not considered rigid lines, and we weigh the cancer risk values with a series of other health measures and factors in both the decision regarding risk acceptability and in the ample margin of safety d etermination. We also consider cost of controls in the ample margin of safety determination. While we analyzed the demographic makeup of the populations surrounding the facilities within source categories addressed by this rule making, we ultimately conclu ded that the risks from each source category were acceptable and protected public health with an ample margin of safety. Thus, the results of our demographic analyses only served to provide information about the demographic makeup of the populations near f

acilities in each of these source categories, but did not drive regulatory

outcomes.

Comment 2.3.3: Commenter 36 states that the EPA should a ssess and account for increased vulnerability due to socioeconomic status and baseline overall health status in it s risk assessment, which could be accomplished by adding a default factor to account for socioeconomic and other community

- based stressors. Response 2.3.3: We are not able to determine the baseline health status of individuals or

communities in a national rulemaking. Individual privacy issues as they relate to health records and the costs that would be associated with such an analysis make the analysis infeasible. Through the EPA’s interim guidance on EJ and the Action Development Process, the agency is

en couraging rule writers a nd policy makers to look at the whole range of factors that impact communities and population groups when crafting rules. The EPA is continuing to discuss and pilot approaches that are consistent with the agency’s responsibilities r egarding EJ as outlined in EO 12898. In determining the need for tighter residual risk standards, the EPA strives to limit to no higher than 100

- in

- 1 million the estimated cancer risk for persons living near a plant if

expos ed to the h ighest pollutant conc entration for 70 years and to protect the greatest number of

persons to a n individual lifetime risk of no higher than 1

- in

- 1 million. Considerations are made for all people regardless of racial or socioeconomic status , and the EPA does not believe it is

n ecessary to establish a default factor to account for socioeconomic and other community

- based

stressors

.



### 2.4 Additional Standards to Address Risks

Comment 2.4.1: C ommenter 36 states that the EPA should revisit or update its presumed acceptable level of c ancer risk considering information learned about children’s and overburdened community’s vulnerability and considering new information on ways to analyze and control the impacts of pollutants on human health. The commenter believes that 100

- in

- 1

million li fetime cancer risk cannot be considered safe or “acceptable.” The commenter also states17

that the EPA should factor in uncertainties and vulnerability factors t o adjust the level of non

cancer risk considered acceptabl e for both chronic and acute exposure

. Response 2.4.1: In 1990, Congress codified in section 112(f) of the CAA the approach we use for our residual risk analyses (i.e., the Benzene NESHAP, 54 FR 38044). Under that approach, there is no single bright line (e.g., a 100

- in

- 1 million cancer risk) t hat indicates that risk is “acceptable.” Rather, multiple health metrics, including the cancer risk, are considered to determine whether the risk is acceptable. Where we conclude that the risk is not acceptable, we cannot consider costs in requiring contro ls to bring risks down to an acceptable level. However, the analysis of whether risk is acceptable is not the endpoint. Once we determine that the existing MACT standards or identify what additional controls are sufficient to ensure risk is acceptable, we again review the health metrics in conjunction with considering the costs of controls to determine whether further additional controls should be required to provide an ample margin of safety to protect public health. The commenter does not explain how scie nce has evolved in a way that would undermine the codified framework for determining acceptability.

Comment 2.4. 2 : Commenter 36 states that the EPA refused to strengthen the existing standards for storage vessels and equipment leaks based purely on its co st

- benefit analysis. The commenter states that the EPA’s approach considered only the cost per ton of HAP emission reduction, without assessing relevant factors such as: the individual HAPs emitted and the impact those HAPs can have at a level below 1 ton; how many people would be affected by the potential emission reductions; where they live and if they are in a community containing multiple HAP sources, or whether they face a longstanding environmental justice impact. The commenter

further states that the EPA also did not consider or address whether the standards would provide any “margin of safety” to protect public health, much less whether the margin is “ample.” Thus, the commenter claims the EPA ignored and violated CAA section 112(f)(2)

. Response 2.4. 2: The EPA disagrees with the commenter’s assertion that the decision to not propose more stringent standards for storage vessels and equipment leaks was based entirely

on a cost

- benefit analysis. As noted in the preamble to the proposed rule, the EPA eval uated the estimated risk reduction that would occur as a result of more stringent standards for these emission points and determined that they were not reasonable, given the level of HAP emissions reduction these options would achieve. W e also considered t hese options as part of our ample margin of safety analysis for each source category, and found that it was not necessary to propose more stringent standards to provide an ample margin of safety to protect public health

.

Comment 2.4.3: One commenter 36 st ates that the EPA is legally required to remove all unlawful exemptions from the emission standards that have previously existed for startup, shutdown, and malfunction ( SSM ) periods, and not to set any new such exemptions. The commenter claims that equipme nt leaks are a kind of equipment malfunction and that EPA may not authorize any such leaks, because to do so would be in violation of CAA section 302(k) and D.C. Circuit precedent in the Sierra Club v. EPA decision. The commenter also stated that EPA’s

pro posal to not update the leak detection and repair (LDAR) requirements is an unlawful authorization of a malfunction exemption. Response 2.4.3 : We disagree with the commenter’s claim that the types of equipment

leaks addressed in the AMF, APR, and PC MACT s tandards are “malfunctions.” Equipment leaks typically occur from equipment such as p umps, compressors, agitators, sampling collection18

systems, open

- ended valves or lines, valves, and connectors in organic HAP service . 40 CFR

63.1 103 and 63.1410 ; See also 63 FR 55185

- 5 5186 (October 14, 1998) and 63 FR 68838 (December 14, 1998) . At the time we developed the MACT standards for these source categories, we recognized that these emission points regularly emit small quantities of HAP, an d we promulgated standards regulating equipment leaks from these components at 40 CFR 63.1103 and 63.1410. These provisions require AMF, APR

, and PC production facilities to monitor for leaks and to repair any detected leaks. These requirements do not esta blish any exemption, and the commenter’s suggestion that leaks are “exempt” from regulation or that they are “authorized” is not supported. While any specific equipment leak is not predictable, the types of equipment leaks addressed by the regulations at 4 0 CFR 63.1103 and 63.1410 are fairly routine emissions from sources and are not the type of unpredictable or infrequent event for which we cannot anticipate when, where or how they may occur and that we generally consider to be malfunctions.19



## 3 .0 Startup , Shutdown, and Malfunction Exemption/Affirmative

Defense Provisions

3 .1 Startup, Shutdown, and Malfunction Exemption

Comment 3.1.1 : Commenter 31 states that the EPA has offered no basis for the statement that control devices will be operating normally in startup and shutdown periods. Th is

commenter and commenter 37 caution that thermal destruction control devices often need to achieve a certain temperature before optimal destruction occurs, and that provisions for startup for those equipment might need to be changed. Commenter 42 cautions that while different standards during startup and shutdown may not be needed for these source categories, alternative standards will be needed for some source categories, such as for ethylene manufacturing and the petrole um refinery sector.

Commenter 31 states that absorbers may need to be operated at different liquid/gas ratios during times of startup or shutdown where gas flow rates can vary and suggests that the rule allow for the use of engineering calculations to esta blish a different liquid/gas ratio during times of startup and shutdown if the calculations demonstrate that the emission reduction requirements

can be met. Similarly, c ommenter 29 recommends that the EPA revise subpart YY to allow for the use of engineeri ng calculations to establish separate operating limits or ranges for periods of startup and shutdown. The commenter states that since performance tests are required to be conducted during periods of normal operation, and not during a startup, shutdown or

m alfunction, engineering calculations are appropriate to establish ranges for periods of startup and shutdown. The commenter provides an example of a situation in which the established parameters can be exceeded while still attaining the emission limits dur ing a period of shutdown. Response 3

. 1

. 1 : The EPA disagrees with commenters ’ assertions tha t it is necessary to

establish separate standard s during periods of startup and shutdown for these source categories

. We note that the commenters did not provide suf ficient information or data to support the establishment of an alternative standard, so we continue to maintain that facilities in these source categories will be able to comply with the standards during periods of startup and

shutdown. For the ethylene ma nufacturing and petroleum refinery sectors, any potential alternative standards for periods of startup and shutdown will be addressed as part of the rulemakings for those specific source categories , and are not addressed in this final rule.

F or the scenari o described by commenter s 29 and 31 , the EPA does not believe it is necessary to amend the existing rule s to explicitly allow the use of design evaluations to

determine alternative operating parameters during periods of startup and shutdown. The

standards being promulgated for periods of startup and shutdown for the AMF, APR, and PC MACT standards are all the same as those during periods of normal operation, and compliance with these standards is required at all times. If necessary, a facility may establish separate operating limits or ranges for a control device during periods of startup or shutdown in order to

meet these standards.

Comment 3.1. 2 : Commenter 39 states that the EPA offers little support for the assertion that it is reasonable to interpret se ction 112 as not requiring the EPA to account for malfunctions in setting emission standards. The commenter states that it does not make sense for the EPA to assert that malfunctions are part of normal operations but then exclude emissions from these
parts of normal operations in the determination of the emission limits. The commenter states that due to the unplanned nature and variety of potential malfunctions, it would be difficult if not20

impossible for the EPA to gather data and set an emission standard for periods of malfunction. Due to these difficulties, the commenter suggests that under the authority of CAA section 112(h), the EPA prescribe alternative design, equipment, work practice, or operational standards where it

is not feasible to set or enforc e a numerical emission limit. The commenter adds that there are work practices that can be identified as being the best to minimize emissions during a malfunction, and the EPA must acknowledge the fact that even the best

- performing sources experience malfu nction events. Response 3.1. 2 : The EPA’s rationale for its approach to malfunctions is discussed in the preambles to the proposed rule and this final action. The EPA has determined that CAA section 112 does not require that emissions that occur during peri ods of malfunction be factored into development of CAA section 112 standards. Accounting for malfunctions would be difficult, if not impossible, given the myriad different types of malfunctions that can occur across all sources in the category and given th e difficulties associated with predicting or accounting for the frequency, degree, and duration of various malfunctions that might occur. Setting work practice

standards under CAA section 112 (h) for malfunctions

– as opposed to startup or shutdown periods

– presents the same issues as setting numerical emission limits given the varied nature of malfunctions. Please see Response 3 .1. 3 for further discussion.

Comment 3.1. 3 : Commenter s 34 and 41 state that the EPA fail ed to provide adequate justification of w hy emission standards that apply during normal periods should also apply to malfunctions when emissions during malfunctions were not considered in developing the standards. The commenter states that CAA section 112 does not give the EPA the authority to

re place MACT limits that consider the emission level achieved by the best performing sources, including periods where such sources experience malfunctions, with an a ffirmative defense to penalties. Commenter 41 adds that by establishing emission limits and s tandards without consideration of unforeseen upset conditions, the EPA is contradicting the CAA requirement that the standards by “achievable.” The commenter contends that since malfunctions were not considered in establishing the MACT floor, and given tha t standards must be “achievable,” the EPA should establish a separate work practice requirement for malfunctions.

Commenter 39 states that the affirmative defense provisions do not cure the EPA’s

failure to set emission standards that are achievable during SSM events and are not a substitute for setting achievable emission standards for these periods.

Commenters 29, 31, and 34 believe the EPA should promulgate separate standards under CAA section 112(h)(1) for periods of malfunction. Commenter 29 suggests t hat the EPA establish a work practice for malfunctions that result in only small levels of excess HAP emissions, such as 1 0 0 pounds of HAP, which requires the owner/operator to stop the emissions, stop the malfunction, and return to normal operations as so on as possible. Response 3.1. 3 : The EPA first notes that, with regard to commenter 39 , the affirmative defense provisions have been removed from the final rules. As we explained in the preamble to the proposed rule, 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 standards. Under CAA section 112, emission standards for new sources must be no less stringent than the level “achieved” by the bes t controlled similar source, and for existing sources, generally, must be no less stringent than the average emission limitation “achieved” by the best performing 12 percent of sources in the category. There is nothing in CAA section 112 that

directs the a

gency to consider malfunctions in determining the level “achieved” by the best21

performing or best controlled sources when setting emission standards. Moreover, while the EPA accounts for variability in setting emission standards consistent with the CAA sec tion 112 case law, nothing in that case law requires the EPA to consider malfunctions as part of that analysis. CAA section 112 uses the concept of “best controlled” and “best performing” unit in defining the level of stringency that CAA section 112 perfor mance standards must meet. Applying the concept of “best controlled” or “best performing” to a unit that is malfunctioning presents significant difficulties, as malfunctions are sudden and unexpected events. Accounting for malfunctions would be difficult, if not impossible, given the myriad different 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. As such, the performance of units that are malfunctioning is not “reasonably” foreseeable. See, e.g., Sierra Club v. EPA , 167 F. 3d 658, 662 (D.C. Cir. 1999) (the EPA typically has wide latitude in determining the extent of data

- gathering nece ssary to solve a problem. We generally defer to an agency’s decision to proceed on the basis of imperfect scientific information, rather than to “invest the resources to conduct the perfect study.”). See also, Weyerhaeuser v. Costle , 590 F.2d 1011, 1058 (D .C. Cir. 1978) (“In the nature of things, no general limit, individual permit, or even any upset provision can anticipate all upset situations. After a certain point, the transgression of regulatory limits caused by ‘uncontrollable acts of third parties,’ such as strikes, sabotage, operator intoxication or insanity, and a variety of other eventualities, must be a matter for the administrative exercise of case

- by

- case enforcement discretion, not for specification in advance by regulation.”). In addition, the goal of a best controlled or best performing source is to operate in such a way as to avoid malfunctions of the source, and accounting for malfunctions could lead to standards that are significantly less stringent than levels that are achieved by a well

- p erforming non

- malfunctioning source. The EPA’s approach to malfunctions is consistent with CAA section 112, and is a reasonable interpretation of the statute.

Comment 3.1. 4 : Commenter 42 notes that in 40 CFR 63.1107(c)(1) and (2), the sections

for malfunc tion recordk eeping and reporting requirements, the word “failures” is used rather

than “malfunctions.” The commenter states that since failures to meet emissions standards that are not due to malfunctions are addressed separately in 40 CFR 63.1109 and 63.1 110, the requiremen ts in these paragraphs should apply to malfunctions only, and the word “failures” should be replaced with “malfunctions.” The commenter also suggests that the requirement to
record the “number of failures” in 40 CFR 63.1107(c)(1) be dele ted because the failure to meet an applicable standard is by its nature a single occurrence, and the requirement to record the date, time and duration of each failure would already provide a count of such occurrences. The commenter also suggests that in 40 CFR 63.1107(c)(1)(ii), the requirements be reworded to clarify that the volume of only the pollutants regulated by the Generic MACT ( GMACT )

standards (i.e., total organic HAP) are required to be estimated and recorded. The commenter

also notes that simila r wording is used in the reporting requirements of 40 CFR 63.1107(c)(2) and suggests the same changes at those for the recordkeeping requirements

. Similarly,

c ommenter 33 also suggests clarifications to the malfunction recordkeeping and reporting requireme nts in 40 CFR 63.1111(c)(1) and (2) to make the format consistent and content clearer.22

Response 3.1. 4 : The EPA first notes that the malfunction recordkeeping and reporting requirements referenced by the commenter are contained in proposed 40 CFR 63.1111(c) (1) and (2), not 63.1107 (c)(1) and (2)

. With regard to the commenter’s suggestion s , we disagree that it is

necessary to replace “failure” with “malfunction” because the malfunction recordkeeping and reporting language is clear that the provisions only appl y to malfunction events, and therefore do not overlap with the requirements of 40 CFR 63.1109 and 63.1110

. Additionally, we believe that the requirement to record the number of failures is necessary, as it shows whether there are multiple malfunctions on t he same process unit. We also disagree that it is necessary to further clarify which pollutants are required to be included in the malfunction report. The final rule uses the term “regulated pollutant,” which for the GMACT is organic HAP

. We also note that we have revised the final rule to require reporting of the “quantity” of regulated pollutants rather than the “volume,” as emissions are typically reported in terms of mass or weight.

Comment 3.1. 5 : Commenter 42 requests that one year be provided for imp lementing the SSM requirements for this and future rules. The commenter claims that time is needed to develop new procedures for handling malfunctions and provide staff training after the rule is finalized. Response 3.1. 5 : The EPA disagrees with the commen ter that one year is necessary for implementation of the revised SSM requirements. T hese requirements should be immediately implementable by the facilities upon the n ext startup, shutdown, or malfunction event. T he EPA has consistently been removing the SS M exemption from rules as part of the risk and technology review process for several years, so facilities should have already begun to educate their staff on

how to handle SSM events and implemented procedures for avoiding such events

.

Comment 3. 1

. 6 : Comm enter 39 states that the EPA has not justified changing conditions that apply to performance testing. The commenter contends that where the proposed rule removed previously applicable references to the NESHAP General Provisions that required performance te sts to be conducted based on normal operating conditions of the affected source and specified that “operations during periods of startup, shutdown, and malfunction shall not constitute representative conditions for the purpose of a performance test,” the p roposal would allow the EPA to direct a source to conduct performance testing during abnormal operations, such as startups, shutdown, or malfunctions. The commenter states that the EPA cannot “amend” existing MACT standards in a way that can make the stand ards more stringent without first providing an adequate justification for departing from the EPA’s previous judgment about the appropriate conditions for performance testing. Response 3. 1

. 6 : As noted by the commenter, we eliminated the SSM exemption as it applies to performance testing under 40 CFR 63.7(e)(1) and we specify that “[p]erformance tests shall be conducted under such conditions as the Administrator specifies to the owner or operator based on representative performance of the affected source for the period being tested” (at 40 CFR 63. 1108(b)(4)(ii) and 63.1413(a)(2) ). One of the reasons for this is because the General Provisions selectively apply to part 63 standards and some part 63 standards establish alternative standards or compliance demonst ration methods during startup and shutdown periods that may require performance testing during startup and shutdown periods. Sections 63.1108(b)(4)(ii) and 63.1413(a)(2) specify the conditions that performance testing must be conducted for the AMF, PC, and APR MACT standards. The final requirements do not allow for performance tests to be conducted during periods of malfunction, and the condition s for conducting performance testing for the existing MACT standards have not changed

.23



### 3 .2 Affirmative Defense Pr ovisions

Comment 3.2.1 : Commenter 36 urges the EPA not to adopt the affirmative defense provisions. The commenter states that the affirmative defense provisions are unlawful and harmful. The commenter argues that Congress plainly intended citizens to be a ble to enforce emission standards under the CAA using the full range of civil enforcement mechanisms available to the government, and, in the HAP context, subject only to the limitation that government not be “diligently prosecuting” its own civil enforcem ent action, according to CAA section 304(b)(1)(B). The commenter further states that the EPA exceeded its authority by attempting to impose additional Agency

- created limits on civil penalties and that the proposed affirmative defense goes directly against Congressional intent that judges should determine the size of civil penalties whenever they are sought, and that the proposal will impermissibly chill citizen participation and the ability to win an effective, deterrent remedy in CAA enforcement actions.

T he commenter adds that allowing only injunctive relief for violations that occur during malfunctions removes the primary deterrent to violations, which is paying a penalty. The

commenter also states that the affirmative defense creates an unlawful after

- th e

- fact exemption, since injunctive relief is still available to try to prevent further future violations, but provides no remedy for a past violation.

The commenter also states that the EPA seeks to rely on a Fifth Circuit case that upheld
the EPA’s author ity to partially approve an affirmative defense provision in a state implementation plan, but the D.C. Circuit will have jurisdiction over these final rules, and there is binding D.C. Circuit case law to suggest it may not follow the Fifth Circuit decision

. The commenter observes that the CAA gives the EPA minimal discretion that only applies to administrative penalties which may be imposed under subsection 113(d), but no authority to compromise, modify or limit civil penalties that a court may impose under section 113(e) or section 304. The commenter states that it is improper for a court to fail to consider these factors, or to fail to make its own determination of what civil penalties are “appropriate” under CAA section 304(a).

The commenter asserts that the burden the affirmative defense places on citizens makes it less likely that they will enforce the CAA, that citizen participation in CAA enforcement will be hindered, in violation of citizens‘ rights to protect themselves from pollution and in direct conflict with congressional intent. The commenter states that the affirmative defense imposes a technical burden on citizens, and the burden renders the defense impermissible. The commenter predicts that the affirmative defense will likely be used on a rou tine basis by polluters seeking to avoid penalties, just as the malfunction exemption was, and enforcement of the CAA could

suffer. The commenter also states that if the EPA had the authority to promulgate any affirmative defense to penalties for malfuncti on, it should also promulgate strong reporting, monitoring, and other compliance measures, require a specific monetary penalty for each malfunction, and require that the affirmative defense cannot be used by a specific facility or company more than once wi thin a set period of time, such as 10 years. The commenter adds that notification of malfunctions or emissions standards exceedances submitted to the EPA by a facility should be made publicly available through the EPA’s website within 7 days. The

commenter further adds that the EPA should also require the facility to provide same

- day community notification through an appropriate public forum, such as the company website, written notice to the local municipality and local school district, or press release to the local24

newspaper, radio and TV news station. The commenter asserts that it is important for malfunction reports to be submitted electronically, be made publicly available as soon as possible, and that facilities should not be allowed to wait until the next semiannual report to report malfunctions.

Commenter 33 adds that the courts, and not the EPA determine whether any defense, affirmative or otherwise, is available for any type of claim, whether in law or in equity, and the EPA has no authority to rest rict the power of the court in an enforcement action.

C ommenters 29, 32, 33, 34, 39, and 46 state that the affirmative defense provisions are overly burdensome and are not realistically attainable due to the specific language of the required

criteria. The commenters request that the EPA clarify and redefine the criteria considering attainability. Commenter s 32 and 33 suggest several modifications to the affirmative defense provisions. One suggestion is to rely on the phrase “preponderance of evidence,” as i s used in paragraph (a) of these provisions but is later contradicted by the use of “any” and “all.” Another suggestion is to make the definition of malfunction match that of the General Provisions, where the phrase “not reasonably preventable” is used rat her than the phrase “sudden, infrequent, and

unavoidable failure.” Commenter s 29 and 33 suggest revising the affirmative defense provisions to remove the requirement for contemporaneous operating logs because their facilities use

electronic media to docume nt actions, and a printed and signed log is an outdated mode of

documentation. Commenter 39 requested that the term “infrequent,” and subjective phrases, such as “if at all possible,” be removed from the regulatory text, as these terms could be subject to different interpretations by regulatory agencies. Commenter 33 states that some provisions are too vague and without defined limits, such as “better operation and maintenance practices” and

“could not have foreseen and avoided.”

Commenter 33 also states t hat many of the requirements are irrelevant to the facts or events of the underlying malfunction, including the requirement that repairs be made as expeditiously as possible. The commenter also states that the steps taken after the violation

occurred to mi nimize the frequency, amount, duration and impact of the violation is not relevant

to whether a violation that occurred was a malfunction

. The commenter declares that whether emissions monitoring and control systems were kept in operation is also irrelevan t to establishing whether the violation is excusable. The commenter adds that the requirement that “At all times, the affected source was operated in a manner consistent with good practices for minimizing emissions,” is a requirement redundant of the gener al duty provisions and is not relevant to

whether a violation would have occurred. The commenter also asserts that the EPA may not condition the availability of an affirmative defense on whether a report regarding the violation was submitted, and the exist ence of such a report is not relevant to whether the violation was caused by a malfunction.

Commenter 29 suggests that as part of the affirmative defense, companies should only be required to report the amount of excess emissions that were the result of a malfunction and not be assessed penalties for any emissions caused by the malfunction.

Commenter 39 is 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 EPA. This commenter states that the EPA must modify the provisions substantially so that they do not require sources to prove their innocence.

Commenters 29, 32, and 33 suggest revisions or removal of the formal root cause analyses required by the affirmative defense provisions. Commenter 32 suggest s a formal root cause analysis should only be required when other reasonable methods fail to show the cause of a25

malfunction or when the serious nature of an event might make such an analysis necessary.

Commenter 29 states that formal root cause analyses are not needed because malfunction events are already routinely investigated and formal root cause analyses will detract from candid inquiries into the events. Commenter 39 states that the root cause anal ysis requirement may make the affirmative defense unavailable if the source is not able to determine the primary cause

of the malfunction. Commenter 33 adds that a defendant should be able to use any and all

evidence to demonstrate the cause of a violation and not be limited to a root cause analysis. The commenter adds that whether the evidence is adequate will be determined by an independent judge, and it is not the EPA’s role to tell a judge what evidence is necessary or sufficient.

Commenter 39 state s th at the EPA estimate of $ 2,375 to assert an affirmative defense for a malfunction is not credible, appears entirely arbitrary, and is remarkably low given the number of different demonstrations and root cause analysis that are required of a source.

Comment er 36 states that the EPA must promulgate specific public reporting and notification requirements for malfunctions and any exceedance that occurs. The commenter declares that the EPA must require telephone reporting by the facility 24 hours of a malfunctio n or exceedance and make a notice available publicly through the EPA’s website and through ECHO within 24 hours. The commenter also asserts that within 24 hours of receiving this notification, the EPA should provide this information to the appropriate EPA Regional Office and direct the Regional Office to notify the local community of the event on the Internet, direct communication, and through all available means. The commenter states that the EPA should further require the facility to provide notification to the community through an appropriate public forum, such as the company website, press release to the local newspaper, radio and TV news station, within 24 hours. The commenter further declares a written report should be required within 7 days and distri buted to the public using the same distribution method as the earlier notification and that this report should include the nature of the event, the duration of the event, and estimate of emissions released during the event, and a description and time of co rrection actions taken and planned to be taken.

Commenter 39 states that it is not clear what civil penalties the affirmative defense covers. The commenter believes the affirmative defense should apply to civil penalties, civil administrative penalties, n oncompliance penalties, enforcement actions by the EPA, states, or

citizen

- suit plaintiffs, and injunctive relief.

Commenter 39 believes the affirmative defense provisions should apply to the potential violation of emission limits during a startup or shutd own event as well as during malfunctions, if

the EPA is to use such affirmative defense.

Commenter 29 requests that the EPA confirm in the final rule that an owner or operator may assert an affirmative defense against civil penalties for a malfunction caus ing a release from PRD in organic HAP service to the atmosphere. Response 3 .2. 1 : The EPA received numerous comments on the affirmative defense to civil penalties for violations caused by malfunctions that the EPA proposed to include in the rule.

Several co mmenters supported the affirmative defense or supported the affirmative defense but made suggestions fo r revisions to its provisions. Other commenters opposed the affirmative defense or various components of the affirmative defense. Recently, the United St ates Court of Appeals for the District of Columbia Circuit vacated an affirmative defense in one of the EPA’s Section 112(d) regulations. NRDC v. EPA , No. 10

- 1371 (D.C. Cir. April 18, 2014) 2014 U.S. App. LEXIS 7281 (vacating affirmative defense provisions in Section 112(d) rule establishing emission standards for Portland cement kilns). The26

court found that the EPA lacked authority to establish an affirmative defense for private civil suits and held that under the CAA, the authority to determine civil pena lty amounts in such cases lies exclusively with the courts, not the EPA. Specifically, the Court found: “As the language of the statute makes clear, the courts determine, on a case

- by

- case basis, whether civil penalties are ‘appropriate.’” See NRDC , 2014 U .S. App. LEXIS 7281 at *21 (“[U]nder this statute, deciding whether penalties are ‘appropriate’ in a given private civil suit is a job for the courts, not EPA.”). The EPA is not including a regulatory affirmative defense provision in the final rule.

In the event that a source fails to comply with an applicable CAA section 112(d) standards as a result of a malfunction event, the EPA’s ability to exercise its case

- by

- case

- enforcement discretion to determine an appropriate response provides sufficient flexibil ity in such circumstances as is explained in more detail in the preamble to the final rule. Further, as the D.C. Circuit recognized, in an EPA or citizen enforcement action, the court has the discretion to consider any defense raised and determine whether penalties are appropriate. Cf. NRDC , 2014 U.S. App. LEXIS 7281 at *24 (arguments that violation were caused by unavoidable technology failure can be made to the courts in future civil cases when the issue arises). The same is true for the presiding officer in EPA administrative enforcement actions. In light of the EPA’s decision not to include the affirmative defense in the final rule, we are not responding to the comments opposing the affirmative defense. With respect to comments that supported the affirma tive defense or supported the affirmative defense but made suggestions for revisions to some of its provisions, the preamble to the final rule explains in detail the EPA’s reasons for not including an affirmative defense provision in the final rule.27



## 4 .0 Electronic Reporting Requirements

Comment 4 .1: Commenter 46 notes that stack test reports are commonly submitted to the ERT by stack testing companies. The commenter is concerned about the requirement for the Responsible Official (RO) to certify complian ce with the testing requirement and/or the test result when it is being submitted by a third party. The commenter states that having a single electronic or paper copy available for technical review provides the RO with better assurance and ability to revie w and verify the information. Response 4. 1 : Originally, the Compliance and Emissions Data Reporting Interface (CEDRI ) in the EPA’s Central Data Exchange (CDX) allowed testers and consultants to submit files of test reports generated through the use of the ERT on behalf of facility owners and operators. The CEDRI no longer allows testers and consultants to submit files on behalf of facility owners and operators. While testers and consultants may prepare files in CEDRI on behalf of facility owners and operat ors, only facility personnel may be registered as certifiers in CEDRI. Only a c ertifier may submit a report.

Comment 4

. 2 : Commenter 31 comments that the proposal to require the use of the Electronic Reporting Tool (ERT) is not appropriate as the costs and burdens imposed cannot yet be determined. Also, the regulated community cannot fully comment on the cost of duplicating reports using the ERT for Method 18 and other methods not currently supported by the ERT.

Commenter s 31 and 37 state that the EPA shoul d ensure the ERT includes the ability to accommodate all of the required test data, including Method 18, which can be quite voluminous. Response 4

. 2 : The rule only requires that test methods supported by the ERT be reported using the ERT. The EPA believes that the costs and burdens of using the ERT are not significant for several reasons. The electronic reporting requirement does not add any additional testing and it does not change the timing of when test reports are due: the requirement only states that

r eports be submitted electronically. The ERT is fully functional and has been used successfully by industry for several years. It was designed to capture all of the information which is submitted in a typical test report and was also designed with input fro m States and the stack testing industry.

Comment 4

. 3 : Commenters 31 and 46 note that without a formal notice that changes are being made to the ERT, facilities are at risk of noncompliance with the ERT requirements because they have no way to know which t est methods must be submitted to ERT unless they actively monitor the EPA’s web site. Response 4

. 3 : The ERT website is kept up

- to

- date with the list of methods that are supported by the ERT. If the facilities wish, the EPA recommends joining the CHIEF lis tserv, which one can do by emailing join

- chief@lists.epa.gov , to be notified of enhancements made to

the ERT. Additionally, the test method dropdown box in the ERT contains a finite list of methods

support ed by the ERT. By using the latest version of the ERT, the facility will know from the dropdown box which methods are supported.

Comment 4

. 4 : Commenters 29, 31, and 46 note that requiring electronic reporting to the

EPA does not increase the ease and effi ciency of data submittal for the regulated community because state agencies also want the reports submitted to them in their own standard format.

Commenter 46 states this additional burden is in direct contradiction to the Paperwork Reduction

Act (PRA)

. Th e commenters request that the EPA work with air agencies to provide a one

- stop28

location for submittal of air emissions testing results. Response 4

. 4 : The EPA worked with air agencies as well as stack testing companies (who typically prepare test reports) to develop the ERT. The ERT was designed to accept data and information that is typically collected during a performance test. Some air agencies have begun accepting the ERT as their reporting mechanism, and with experience, we believe acceptance by other air agencies will increase. In some instances air agencies may still want a hard copy of a test report. The ERT can generate a printed test report or export the report to a word processor for reformatting. This report can be submitted to the air agency. Th e EPA believes that electronic reporting is a more efficient way to collect test data and has set up a retrieval system such that air agencies can access files that have been submitted using the ERT.

As more air agencies adopt electronic reporting, we beli eve that the need for paper reports will

be diminished.

Comment 4 .5: Commenter 31 comments that under the proposed rule 40 CFR

63. 1110(a)(9) and 63.1417(h)(8) , all performance test reports must be submitted to the ERT within 60 days, but because the rule does not reference the general provisions 40 CFR 63.10(d)(2), there is no allowance for obtaining additional time to complete this due to unforeseen circumstances or for the difficulties involved with completing particularly complex
reports. Response 4. 5 : The commenter is correct in that 40 CFR 63.10(d)(2) is not currently applicable to either Part 63 Subpart YY or Subpart OOO. The EP A does not believe that

additional time needs to be provided for performance tests submitted using the ERT, as the ERT is ful ly functional and has been used successfully by industry for several years

. Therefore, the EPA does not think that it is necessary at this time to add 40 CFR 63.10(d)(2) as applicable. If a facility requires additional time to submit the results of their p erformance test, they may submit a request under the existing provisions in 40 CFR 63.1112 and 63.1417

.29



## 5 .0 Open Ended Line Provisions

Comment 5. 1 : Commenters 40 and 46 state that in the past, the EPA concluded that monitoring of caps

, blind flanges, pl ugs, and second valves was not required since these did not meet the definition of “equipment.” Commenter 29 adds that these components are not usually in regulated material service if there is a closed valve upstream, and therefore regulated sources

would not typically monitor these components. Response 5

. 1 : Open

- ended lines and valves are equipment which require the proper installation and use of caps, blind flanges, plugs and second valves to seal the OEL to prevent

leaks. However, t he EPA does agree wi th the commenters that monitoring of OELs is not currently required by the LDAR provisions for the AMF, PC, and APR MACT standards.

Comment 5. 2 : Commenter 42 states the EPA proposed to add a “no detect a ble emissions” limit and monitoring requirement for O ELs to part 60 subpart VV in 2006, which contains the same OEL equipment standard as in subpart UU, and provided emission and cost estimates to support the proposed limit and monitoring in a 2007 Notice of Data Availability (NODA). This commenter and comme nter 40 state that this action demonstrates that EPA believed as recently as 2007 that this change requires rulemaking. In addition, commenter 42 states that the fact that the EPA took action to propose a “no detectible emissions” limit and monitoring requ irement for OELs to subpart VV confirms that these requirements did not already include such a l imit or monitoring requirement.

Commenter 42 further states that t he proposed definition of “seal” requires that a source demonstrate that the OEL is sealed by instrumental monitoring, but does not specify any details of that monitoring. The commenter states that in order to demonstrate an OEL is sealed at all times, it would appear that it must be monitored (on some undefined frequency) to ensure compliance with the proposed standard. Commenter 31 states that while there are no proposed monitoring requirements in the rule, facilities will have to establish their own monitoring

program s and schedule s for OELs without any assurance that their individual program s or schedule s would be considered to be in compliance by an EPA inspector. Commenters 37 and 46 also request clarification about whether routine monitoring is expected for OELs, given that the proposed definition references a Method 21 reading of less than 50 0 ppm. Commenter 29 adds that if the intent is to require routine monitoring of these components, rule changes are needed to add time periods for completion of repairs. Commenters 29 and 31 contend that if the EPA does intend to require periodic monitoring , such monitoring rules must be clearly proposed in a second rulemaking with a public comment period. Commenter 46 states that if the new term is established, the EPA should, at a minimum, subject the “seal” to the visual repair requirements of subpart UU, which would then also include leak repair requirements rather than an automatic

violation of the OEL requirement. Commenter 33 adds that the essence of the LDAR work practice standards for leaking equipment is that the discovery of a leak triggers a repai r requirement, and leaks are not automatic violations of the rule.

Commenter 31 states that the EPA did not develop any cost estimates or impacts on the regulated community resulting from the proposed definition of “seal.” However, the commenter

states tha t facilities will need to develop monitoring plans and regularly monitor OEL seals to ensure they have instrument readings below 500 ppm, which will require capital costs including identifying, tagging and updating software systems for OEL seals. C ommenter 42 also states that given the large number of OELs in refineries and chemical plants, the costs and burdens for monitoring OELs, even infrequently, are substantial and are not addressed in the rulemaking30

record or the Information Collection Request ( ICR ) for the three source categories specifically addressed in this proposal. The commenter also notes that the record does include any information on the likely emission reductions associated with this change, which the 2007 NSPS VV and GGG rulemaking record s uggests would be minimal. Response 5

. 2 : The EPA is not imposing monitoring for OELs. There are no additional costs associated with the clarification that OELs be sealed. We also disagree with the commenters that the EPA is requiring facilities to regularly monitor their OELs, and thus incur capital and annual costs. The requirement that OELs be sealed is not a new standard and there is no requirement in any of the LDAR requirements for these source categories that requires facilities to monitor their OELs o n a regular basis. Furthermore, since this is a not a new requirement, there are no new emission reduction estimates associated with this clarification of the “seal” definition.

Comment 5. 3 : Commenters 33 and 40 state that the term “seal” does not denote a certain numeric precision, and within the context of LDAR requirements in MACT standards, the EPA’s decision not to include a precise definition in the existing rules, which do include numeric leak definitions for other components, is a clear signal that the term “seal” does not implicitly incorporate a numeric leak definition. The commenters also state that the requirement to cap OELs was never “zero emissions” standard, but rather a work practice in the form of an equipment standard, and the proposed de finition would transform this work practice into a

n umeric emissions limit. C ommenter 29 states that the OEL provisions are “equipment standards” and compliance is determined by whether a cap, blind flange, plug

, or second valve is physically installed, an d the term “sealed” historically has meant one of these devices is present. Response 5

. 3 : The EPA disagrees with the commenter. The EPA’s intent has always been that caps, blind flanges, plugs or second valves that are installed on OELs provide a seal, i.e

. , no detectable emissions. This is further supported by examples of compliance audits conducted by OECA and Regional enforcement personnel in which companies were cited for OELs not being

sealed. We have placed these audits in the docket for this action.

Comment 5. 4 : Commenter 42 notes that while until the mid

- 2000’s the EPA issued a multitude of OEL citations for failing to cap or plug an OEL, only since about 2005 have some
of these citations identified a failure to meet a “no detectible emissions” lim it as a parameter. The commenter notes that in most cases, the EPA continues to cite facilities for failing to have a cap or plug in place, without consideration of whether that OEL is leaking at more than 500 ppm,

but each failure would apparently now be two violations

- one for failing to meet the equipment standard and one for failing to meet the 500 ppm emission limit. Response 5

. 4 : The EPA disagrees with the commenter that the scenario in question would result in two separate violations for the facilit y. By defining “seal” to mean a reading of less than 500 ppm above background using instrument monitoring by Method 21 , we are clarifying an existing requirement that the OEL be operated with no detectable emissions. This is

consistent with how OECA has be en enforcing this requirement during their inspections, and will not increase the number of violations issued for having a reading greater than 500 ppm from an

OEL.

Comment 5. 5 : Commenters 29 and 31 state that there are cross

- referencing issues with the p roposed “seal” definition for OELs. Commenter 29 notes that for PC facilities complying31

with 40 CFR part 63 subpart H for equip ment leaks, it is ambiguous what the term “seal” means relative to the open

- ended valve or line requirements in subpart H at 40 C FR 63.167(a)(2).

Commenter 31 notes that the AMF, PC

, and APR subparts cross

- reference subpart UU and states that if the EPA revises the definition of “seal” for these subparts, then it will also need to propose changes to subpart UU at 40 CFR 63.1033 to i nclude the proposed emission limit of 500 ppm for OELs. The commenter adds that the EPA must update Method 21 to accou nt for accurate OEL monitoring. Response 5

. 5 : It was the EPA’ s intent that the term “seal” would apply to the LDAR requirements in subpart H as well, for those facilities that are complying with those provisions as part of the GMACT. As such, we have revised the definition of “seal” to clarify that subpart H is also included. With regard to commenter 31 ’s suggestion, t he EPA is not imposing an emission limit for OELs

, but rather we are clarifying the existing requirement that OELs be

sealed. As such, it is not necessary for us to include a new emission limit in subpart UU.32



## 6 .0 Pressure Relief Device Provisions

Comment 6. 1 : C ommenters 31, 3 3, 38, 39, 42, and 46 state that PRDs are safety devices, and these requirements will ask plant operators to choose between safety and committing a

violation. Commenters 31, 38, 39, and 46 claim that this position is in direct contrast to the General Duty provisions, which state that, “at all times, the owner or operator must operate and maintain any affected source, including associated air pollution control equipment and monitoring equipment, in a manner consistent with safety and good air pollution contr ol practices for minimizing emissions...” Response 6. 1 : The EPA disagrees with the commenters that we are forcing plant operators to choose between safety and committing a violation. We recognize that industry has

stated that they believe releases from PRDs sometimes occur in order to protect systems from failures that could endanger worker safety and the systems that the PRDs are designed to

protect. We have provided a balanced approach that is consistent with the General Duty provisions and is designed to minimize emissions while recognizing that these events may be

unavoidable even in a well

- designed and maintained system.

Comment 6. 2 : Commenter 31 cites the EPA’s statements that PRD releases are caused by malfunctions and that the EPA is not required to establish separate standards for malfunctions because it is not required to do so, and it is too difficult to do so. The commenter asserts that a PRD release is unique in that the “release” is an inherent function of the device, and therefore a work practi ce standard or a numerical emissions limit could be established. The commenter believes the EPA could have considered data submitted by the commenter along with data from California’s South Coast Air Quality Management District to determine whether it may be feasible to group PRDs with process vents and propose a numerical emission standard under

CAA section 112(d)(3). Alternatively, the commenter states the EPA could have established a work practice standard for PRD releases pursuant to its authority under CAA section 112(h). The commenter urges the EPA to consider either of these approaches. Response 6. 2 : We disagree with the commenter. The releases are related to process upsets or other malfunctions that require the release of pressure to avoid damage to equipment and to prevent harm to personnel at the facility. Such releases are not routine, are unpredictable in nature, and are considered to be caused by malfunctions (e.g., poor design, improper maintenance, or operational error) that do not justify bein g allowed to continue

. The commenter failed to establish that the criteria for setting a work practice had been met, and as we explained in the preamble, it is impracticable to establish work practices or other alternative standards to manage these events and CAA section 112 does not require that we do so. In addition, t he commenter has not provided information that would support MACT floor and beyond

- the

- floor analyses to set numeric limits or work practice standards, in lieu of a prohibition of these malf unction emissions. Nor has the commenter provided cost or technological information on options to control such malfunction emissions to the atmosphere, even if the EPA were to consider it appropriate to set MACT limits for them.

Comment 6. 3 : C ommenters 39 , 40, and 42 assert that the EPA provided no evidence or justification of its assertion that PRD releases to the atmosphere are caused by malfunctions, and

that

, in fact, PRDs that release to the atmosphere due to excess pressure are functioning exactly

as designed and are not malfunctioning. Commenter 42 states that while the MACT standards, including the GMACT, recognized that pressure releases can be due to malfunctions, typically in33

the definition of pressure release, this does not indicate that all pre ssure releases are due to

malfunctions. The commenter further states that the EPA has been clear in all its discussion of malfunctions and in its enforcement that for an event to be a malfunction, it must generate excess

emissions relative to the Federal r ule being considered. The commenter also notes that the event must have been due to a sudden, infrequent

, and not reasonably preventable failure and not due to poor maintenance or careless operation to meet the definition of malfunction. The commenter

stat es that most pressure releases do not meet the definition of malfunction. The commenter also

states that the treatment of malfunctions before or after Sierra Club v. EPA has no bearing on pressure releases not related to malfunctions.

Commenter 42 also sta tes that the EPA cannot interpret the term malfunction narrowly for the purposes of affirmative defense and broadly with respect to PRDs. Commenter 33 states that the proposed definition of “pressure release” could be interpreted to be limited to only

emis sion events that release to the atmosphere, and requests that the definition be revised clarify that the emission of materials from the PRD includes emissions to the atmosphere, to a closed vent system and control device , or to a process. Both commenters r equest that the definition of “pressure release” should be revised to reflect the fact that pressure releases do not only occur due to p rocess malfunctions and suggest removing the last phrase of the definition “due to a malfunction in the process” to clar ify this point

. Response 6. 3 : The EPA agrees with the commenters that not all pressure releases are caused by malfunctions and has revised the definition of “pressure release” to remove the phrase “due to a malfunction in the process.” Regarding commenter 33 ’s request for further clarification, we believe that this definition is already broad enough to include emissions to the atmosphere, control device, process, etc. A “pressure release” is defined as the release of materials from the system pressure excee ding the set pressure of the PRD, so it does not restrict where those materials are emitted to, nor what was the cause of the release. We also note that

the prohibition and monitoring requirements do not apply to PRD release emissions that are captured and routed to a control device, process, fuel gas system or drain system, since such emissions are not released to the atmosphere. As discussed in the Background Information Document (BID) for the HON, only those pressure releases that occurred as a result of a malfunction were able to use the SSM exemption (page 4

- 21). We also note that t he definition of “pressure relief device” states that a PRD is “a safety device used to prevent operating pressure from exceeding the maximum allowable working pressure of th e process equipment.” If, as the commenter asserts, most pressure releases do not meet the definition of “malfunction” (i.e., “ sudden, infrequent, and not reasonably preventable ”), then this implies that the PRD may be releasing often or at regular

interva ls and not necessarily due to process upsets. This further reinforces the EPA’s decision to prohibit HAP emissions from PRDs, as such unregulated emission points may result in a significant amount of uncontrolled HAP released to the atmosphere.

Comment 6. 4 : Commenter s 45 and 46 state that they ha ve effective program s in place to prevent pressure releases from PRDs , but that not all system components specifically have “time

and duration” monitor ing capability or flow monitoring equipment. However, the comme nters believe sufficient information is almost always available to adequately determine the approximate time and amount of a HAP release. The commenters ask that the EPA limit the required monitoring to primary reaction vessels or to locations where pressu re releases would likely occur during the normal course of processing and exclude systems or devices from the34

PRD requirements for insignificant releases of liquids, releases from small devices, and/or

releases that will result in emissions below the relev ant standard. C ommenter 45 urges the EPA to consider allowing industry to establish a “standard of care” for PRDs in lieu of requiring specific monitoring or prohibitions. Response 6. 4 : The EPA notes that the PRD monitoring provisions do not require a fac ility to equip each PRD with a specific device to monitor time, duration, or flow rate. Rather, the monitoring equipment or system must be capable of recording the time and duration of the leak, and facilities may use their best engineering judgment to cal culate the emissions released during the pressure release event. The EPA also disagrees with the commenters’ suggestion to limit the applicability of the PRD monitoring requirements to only certain PRDs

, as all emissions from PRDs in organic HAP service th at release to the atmosphere should be regulated, regardless of where they are located within the process. We also do not believe that a “standard of care” approach for these emission points is appropriate, as this would not ensure a consistent level of mo nitoring for PRDs across the source category.

Comment 6. 5 : Commenter 46 notes that pressure releases due to over

- pressurization are

evaluated on a case

- by

- case basis and reported to the respective agencies via Title V permit conditions and/or MACT reporti ng requirements. The commenter believes the proposed PRD monitoring and reporting requirements are duplicative of the existing requirements. Response 6. 5 : The EPA disagrees with the commenter that the proposed PRD monitoring and reporting requirements are duplicative of existing requirements. There were previously no requirements for these source categories that would require each facility to monitor their PRDs and report each release to the atmosphere . While certain states may have these requirements for

c ertain PRDs or releases above a certain threshold, the EPA believes it is important to require all facilities subject to the AMF, PC, and APR MACT standards to monitor and report all PRD

releases to the atmosphere , as this ensures that these releases will be reported nationally and not just in some states.

Comment 6. 6 : Commenter s 38 and 42 state that controlling large atmospheric PRD releases is very costly, cost ineffective, and raises safety and environmental concerns. The

commenters state that these PRD s are routed to the atmosphere because releases are very infrequent, routing them to flare systems can create backpressure and additional safety problems, the addition of flares increases emissions because of the additional pilot, purge and sweep gas

combu stion, flares are very expensive, space for new flares may not be available, and the community objects to the addition of flares. C ommenter 42 a lso notes that additional flaring would have a negative impact on the EPA’s efforts to reduce flaring and flare emissions.

Commenter 38 states that the EPA presumes it is technically feasible to vent all existing PRDs to existing control equipment but did not provide analyses of the feasibility or costs to support this

conclusion. Response 6. 6 : The EPA is not requi ring, nor do we claim it is necessarily feasible, for all PRDs to be routed to a flare or other control device. Rather, the EPA is not requiring that PRDs

that route to a control device , process, or drain system be prohibited and monitored , since

emissions from these PRDs will not be released uncontrolled to the atmosphere

.

Comment 6. 7 : Commenter 37 states that there are 5 PRDs at its facility, and there have been no known releases from these devices in the past 5 years, so it is difficult to identify the35

benefit from monitoring these devices. However, the commenter supports the proposed flexibility to use parametric monitoring of the affected equipment or monitoring devices on the PRDs, if such monitoring is to be required. The commenter indicates that ex isting parametric monitoring will be sufficient for its facility to meet the PRD monitoring requirements.

C ommenter 46 states that the EPA’s estimate of 5 PRDs per facility is reasonable, but it failed to consider operating and maintenance costs for PRD mo nitors, such as a written operating program, data management, spare parts and reporting requirements, which the commenter

estimates could be 10% of the installed cost. Response 6. 7

: The EPA thanks the commenter for their support of the flexible PRD

monitor ing provisions. With regard to the comment on the EPA’s cost estimate for monitoring of PRDs, we believe that our costs represent the most expensive approach to satisfy this requirement (installation of electronic indicators on each PRD in organic HAP serv ice), and that actual costs will be significantly less.

Comment 6. 8 : Commenter 46 states that the design of PRDs should be governed by good engineering practices and regulatory programs such as ASME standards, OSHA’s process safety management standard and the EPA’s risk management program exist to serve the hazards

involved. The commenter states that addition al PRD requirements in a MACT standard unnecessarily duplicates existing programs that already provide for adequate monitoring. The

commenter also sta tes that no single design monitoring standard for the several types and styles of PRDs can possibl y work. Response 6. 8 : The EPA disagrees with the commenter that we are limiting the types of PRDs that can be used at a facility. Our requirements for PRDs o nly require that they be monitored for pressure releases using a device or parameter monitoring system capable of identifying and recording the time and duration of each pressure release and of notifying

operators immediately that a pressure release is occ urring . Nowhere do we restrict what type of PRD a facility may install on their equipment, and to assert so is incorrect. As stated previously, we disagree that the PRD monitoring requirements finalized in these rules are duplicative of existing programs.

Comment 6. 9 : Commenter 29 requests that the compliance dates for the PRD requirements dates in both subparts YY and OOO should not only reference the monitoring requirements but also the associated recordkeeping and reporting requirements. Commenter 38

re quest s three years to comply with the PRD requirements rather than the one year proposed. The

c ommenter states that it would take more than one year to perform the assessment, design, engineering, procurement, and installation for PRD monitoring equipment and also more than one year, if it can be done at all, to implement a system to route PRDs to control devices. Response 6. 9 : The EPA notes that the proposed PRD monitoring requirements did provide three years with which to comply with the requirements, an d not the one year mentioned by commenter 38 . Regarding commenter 29 ’s request for clarification , it was the EPA’s intent

that the associated PRD monitoring recordkeeping and reporting requirements take effect upon promulgation of the final rule amendments . Since the prohibition of HAP emissions to the atmosphere from PRDs in organic HAP service takes effect immediately, it is important that information about these releases be included in a facility’s semi

- annual report. While installation of a PRD monitori ng system is not required until three years after promulgation of the final rule amendments

, we expect facilities to be able to provide a reasonable estimate for36

this information in the interim , especially since they are already required to report most of this information after a pressure release event as part of compliance with the LDAR provisions of subpart UU.

Comment 6. 10 : Commenter 29 states that the PRD requirements for PRDs in upstream rupture disks in subparts YY and OOO should be changed to be con sistent with the recently finalized rules for 40 CFR 63 subparts JJJ, MMM

, and PPP, which include provisions to require replacement of the rupture disk within 5 days of a pressure release. Th is commenter and

commenter 37 also request that the EPA clearly d efine when the 5

- day Method 21 clock begins following a pressure release. The commenter s suggest that a reference to the leak rep air schedule of subpart UU in 40 CFR 63.1024(a) be inserted. Commenter 33 adds that monitoring after replacement of a rupture d isk seems pointless since a rupture disk is impermeable. Commenter

45 requests that pressure checks be allowed after the installment of a replacement rupture disc after a pressure release rather than monitoring to verify that the pressure relief device is properly operating

. Commenter s 29 and 33 state that the EPA should include delay of repair provisions

for PRDs like those contained in 40 CFR 63.1030 of subpart UU. Commenter 46 requests that the EPA revise the definition of PRD to exclude those with ruptu re disks because rupture disks do not and cannot regulate the pressure within the process and are true safety devices. This commenter believes they should be treated differently than spring

- loaded devices, which can be used to regulate pressure. Alternativ ely, the commenter requests that the EPA designate PRDs with rupture disks that have burst disk indicators as a parameter monitoring system. The commenter notes that if rupture disks are not excluded from the definition, the company will

need to incur addi tional costs to install PRDs that are more suitable to the types of monitoring devices the EPA has described (i.e., acoustic sensors and pressure/differential pressure sensors). Response 6. 10 : The EPA agrees with the commenters ’ request for the addition of delay of repair provisions for leaking PRDs and has added these provisions to the final rules . The EPA also agrees with commenter 33 ’s request to remove the monitoring requirement after replacement of a rupture disk. Since we have removed this requirement , commenter 45 ’s request

is moot. With regard to commenter 46 ’s question on burst disk indicators, the EPA believes that the PRD monitoring provisions are flexible enough to allow this type of monitoring system, provided that the system is capable of ident ifying and recording the time and duration of each

pressure release and of notifying operators immediately that a pressure release is occurring

.

Comment 6. 11 : Commenter 46 states that for the APR source category, subpart UU clarifies which equipment is su bject to the provisions of the subpart, which excludes equipment in regulated material service less than 300 hours per year, equipment in vacuum service and lines and equipment not containing process fluids. The commenter states the EPA did not recognize o r document these exclusions when proposing the new PRD requirements. Response 6. 11 : The EPA notes that the existing equipment applicability requirements in subpart OOO already define which equipment are subject to the existing MACT standards in 40

CFR 63. 1400(b), which includes equipment intended to operate less than 300 hours per year as part of the affected source for the rule. Given the specificity of the rule’s applicability requirements, we believe it would be inappropriate to apply the 300 hour per y ear exclusion suggested by the commenter. We also note that equipment not containing process fluids are already exempt from the definition of an amino/phenolic resin process unit.37

Comment 6. 12 : Commenters 29, 31, 37, and 42 suggest certain types of PRDs s hould be excluded from PRD monitoring requirements because they have a low potential to emit large quantities of HAP. These commenters specifically state that PRDs in liquid service should be

excluded. C ommenter 29 adds that to be consistent with the recen tly finalized amendments to 40 CFR 63 subparts JJJ, MMM

, and PPP, PRDs in light liquid service that are routed into a drain system should be excluded. Commenter 37 further adds that tank conservation vents should be

excluded because these devices are used to reduce the amount of vapor loss from the tank . For PRDs with little potential for loss to the atmosphere, th is commenter and commenter 31 suggest
that the EPA set a de minimis reporting value equal to the reportable quantity (RQ) values in

EPCRA and/or CERCLA. Commenter 42 states that no explanation or CAA authorization, including the costs, burden or emissions reduction, was provided for amending the existing work practice requirements for PRDs in liquid service. The commenter states that the provisions of 40

CFR 63.1029 are more adequate and appropriate for this class of PRDs

Commenter s 29 and 42 suggest that , to be consistent with 40 CFR subparts UU and U,
gaseous streams from PRDs routed to fuel gas systems be excluded along with streams routed to

con trols and processes. C ommenter 42 also requests that the provision be clarified to also treat piping that routes a vent stream to a process, fuel gas system or a recovery device as a closed vent system, since the GMACT closed vent system definition only in cludes such equipment that is routed to a control device. The commenter also requests that the language be clarified to exclude PRDs that are controlled, even if there are other PRDs on the same piece of equipment that could route to the atmosphere. Respon se 6. 12 : We do not agree with the commenters’ suggestion that PRDs that emit smaller amounts of HAP to the atmosphere should be excluded from PRD monitoring and reporting requirements . The EPA agrees with commenters 29 and 42 ’s suggestion to exclude

PRDs t hat release to a drain system or fuel gas system from the PRD monitoring provisions. With regard to monitoring of tank conservation vents, we do not believe that these vents meet the definition of a PRD and therefore are not subject to PRD monitoring requi rements. We do agree

with commenter 42 ’s suggestions that we clarify the provisions governing closed vent systems

and which PRDs are subject to the monitoring requirements, and we have revised the final rule to reflect these changes.

Comment 6. 13 : Comment er 29 state s that the EPA should clarify in 40 CFR

63. 1107(e)(3) and 63.14 11(c)(1) that the trigger for reporting pressure releases are excess emissions and not malfunctions of pressure release indicators or process parameter monitoring
systems

. Commenter 42 also suggests the proposed language of 40 CFR 63.1107(e) be revised to clarify that the PRD release provisions only apply to PRDs that release to the atmosphere. Response 6. 13 : The EPA agrees with commenter 29 and has revised the final PRD monitoring r equirements to no longer state that a malfunction of the release indicator or monitoring system is itself a violation. The EPA also agrees with commenter 42 that the PRD monitoring requirements only apply to PRDs that release to the atmosphere, and believe the final requirements reflect this.

Comment 6. 14 : Commenter 33 requests that the EPA clarify that it is an option to route pressure releases through a closed vent system to a control device or to a process and comply only with 40 CFR 63.1107(e)(4) or to comply with 40 CFR 63.1107(e)(1)

- (3) if pressure releases

are not routed in this manner. The commenter also requests that the EPA clarify the provisions of38

40 CFR 63.1107(e)(4), which state that the closed vent system and control device PRDs are

routed to must comply with 40 CFR 63.1034 of subpart UU, which in turn references subpart SS. The commenter states that it is unclear whether the EPA intends for pressure releases sent to a closed vent system and control device to be treated as if they were equipme nt leaks. Response 6. 14 : The EPA agrees with the commenter that if a PRD is routed to a control device or process meeting the requirements of 40 CFR 63.1107(e)(4), then they retain the option to comply either with the requirements in 40 CFR 63.1107(e)(1)

- (3) or 63.1107(e)(4)

. Regarding
the commenter’s question on whether pressure releases are to be considered equipment leaks, w e have added language to the final rule stating that, when referencing the provisions of 40 CFR 63.1034, the term “pressure relief device” shall apply instead of “equipment leaks,” in order to clarify this issue.

Comment 6. 15 : Commenter 29 states that some facilities in the PC source category were originally subject to 40 CFR part 63

, subpart H

, rather than either 40 CFR part 63

, sub part TT or

UU

, and continue to comply through subpart H, as allowed by the rule overlap specifications of subpart YY in 40 CFR 63.1100(g)(4)(ii). The commenter requests that clarification be added to the equipment leaks portions of the PC requirements tabl es in subpart YY to include a reference to subpart H. The commenter also states that although it is clear in the tables to the rule, the EPA should clarify in 40 CFR 63.1107(e) that that owners or operators are obligated to comply with the requirements of that paragraph rather than PRD requirements in subpart UU or subpart H. Response 6. 15 : The EPA agrees with the commenter and has incorporated references to

the HON L

DAR provisions and clarified which PRD provisions apply to affected sources.

Comment 6. 16 : Commenter 33 states that the concept of “in organic HAP service,” is not defined for the new PRD provisions. The commenter requests that the EPA clarify the rule text to accomplish this in the non

- LDAR PRD context. Response 6. 16 : The EPA has added the def inition of “in organic HAP service” to the final rule, consistent with the definition used in both the HON and subpart UU.

Comment 6. 17 : Commenter 45 is concerned that the EPA may propose similar PRD requirements for 40 part 63 subpart FFFF, which the fac ility is also subject to. Some of the operations subject to subpart FFFF are very small and would have very small if any releases to the atmosphere from PRDs but would have the same costs as those associated with larger operations for installing and operat ing PRD monitoring systems. Response 6. 17

: The EPA cannot speculate as to whether or not the final requirements in this action are appropriate for the source category cited by the commenter. The EPA will consider this issue if and when it arises in a futu re rulemaking for that source category.

Comment 6. 18 : C ommenter 36 supports the EPA’s recognition of the need to remove all SSM exemptions, including the need to prohibit releases to the atmosphere from PRDs and require monitoring of such devices. Respon se 6. 18 : We agree with the commenter that pressure release emissions to the atmosphere from PRDs should not continue to be permitted to occur. HAP emissions as a result of pressure releases from PRDs do occur, are considered to be the result of malfunction s, and are prohibited.39



## 7.0 Source Category and Subpart

- Specific Comments

7.1 Source Category Specific Comments

– Acrylic and Modacrylic Fibers

Production

C omment 7.1. 1 : Commenter 41 concurs with the EPA’s conclusions that the residual

risks associated wi th the AMF source category are less than the human health and ecological risk screening thresholds, that the multiplication factor of 10 for estimating acute risks is conservative, that beyond

- the

- floor controls for existing solution polymerization spinnin g lines

are not reasonable based on cost and are not needed to support the EPA’s finding that the AMF MACT standards sufficiently protect public health, and that further control options are not needed for other emissions sources to protect human health.

R esponse 7.1. 1 : We thank the commenter for this feedback.

Comment 7.1. 2 : Commenter 41 requests that the EPA formally designate weighted manway relief devices on affected HAP storage tanks as open

‐ ended lines or valves that are exempt from the requirement to be “sealed” per 40 CFR 63.1033(c) and (d). These relief devices currently do not fit any of the equipment definition s for LDAR components (e.g., valve, OEL

, PRD). The commenter states that at i ts facility, t his device is part of the safety design of a tank storing potentially polymerizing material and is there to prevent pressure build up if a runaway polymerization reaction occurs . This device is currently conservatively categorized as a valve in vapor service and monitored with a leak definition of 10,000 ppm under 40 CFR Subpart TT. The commenter states that if it is treated as a valve under Subpart UU, significant modifications

to the current safety system and possibly tank design would be ne eded to meet the 500 ppm leak definition, and limited emissions reduction would result. The commenter believes a more appropriate designation would be to consider the weighted manway an open

‐ ended valve or line that is part of an emergency shutdown system and that if sealed would present an explosion, serious overpressure or other safety hazard . Cytec has historically not considered the weighted manway to be an “open

‐ ended line or valve” because the definition of this equipment in 40 CFR 63 Subpart TT spec i fic ally excludes “relief valves.” Alternatively, the commenter proposes to allow compliance with either 40 CFR 63 subpart UU or subpart TT for these devices, in addition

to the connectors th at already have this option. Response 7.1. 2 : The E

PA believes that the commenter may have mischaracterized the weighted manway on their storage tanks as a valve in vapor service. Based on the commenter’s description and conferring with storage tank inspectors within OECA, we believe that the manway most likely fits the d escription of a deck fitting on the storage tank, and not a valve or connector. If this is the case, the LDAR requirements and 500 ppm leak definition in subpart UU would not apply. See 57 FR 62660 (December 31, 1992) for additional information on manways and how they are addressed under LDAR provisions.

Comment 7.1. 3 : Commenter 41 points out the limits for existing solution polymerization

sources are based on total organic HAP , whereas limits for new, reconstructed or existing suspension polymerization li nes are based only on acrylonitrile. In addition, the commenter notes

that the LDAR compliance requirements are inconsistent in that some are based on organic HAPs and some have only acrylonitrile limits. The commenter requests that these requirements

be m ade consistent to reflect either organic HAP or acrylonitrile limits for all existing and new processes in the AMF source category and for all equipment services. The commenter adds that40

if the EPA decides to word the requirements in terms of organic HAP, the definition of “in organic HAP service” should be added to subpart YY, and should include “equipment that contains or contacts greater than or equal to 10 weight percent organic HAP” rather than the definition provided in subpart UU, which specifies 5 w eight percent organic HAP. Response 7.1. 3 : The EPA agrees with the commenter and has revised the final rule to consistently refer to organic HAP instead of strictly acrylonitrile

. The EPA has also added the definition of “in organic HAP service” to the fin al rule, consistent with the definition used in both the HON and subpart UU. However, to be consistent with the rest of the AMF provisions

, this definition includes the 10 weight percent threshold suggested by the commenter.

Comment 7.1. 4 : Commenter 31 ag rees with the EPA’s conclusion to set the MACT floor at the current emissions limit for the one identified source in this category. The c ommenter also agrees with the EPA’s proposal to require monitoring under subpart UU, with the exception of

connectors, provided the EPA also finalizes the proposed compliance timeline of one year for existing sources in 40 CFR 63.1102(b). Response 7.1.4: We thank the commenter for this feedback

.



### 7. 2 Source Category Specific Comments

– Amino/Phenolic Resins Production

Com ment 7.2.1: Commenter 31 agrees with the EPA’s conclusion that the costs for Option 1 for APR storage vessels are reasonabl e. Commenter 37 concurs with the EPA that the options to increase the tank control efficiency requirements in subpart OOO to 95% or 9 8% are above the floor options, that the incremental costs per tank are $2400 and $2,200,000, respectively, and that these options should not be considered in the final rule due to the high

costs and minimal incremental emissions reduction. Commenters 31 a nd 37 also agree with the EPA’s conclusion that the costs of either beyond

- the

- floor option for APR continuous process vents are not reasonable given the anticipated level of HAP emissions reductions achieved with the control options. Response 7. 2

. 1 : We t hank the commenter s for this feedback

.

Comment 7. 2 .2 : Commenter 46 requests that the EPA change the compliance date for the storage tank requirements to 3 years from the effective date of the final amendments rather

than the effective date of the final am endments to allow facilities the necessary time to evaluate the need for and type of controls required for storage vessels in the APR source category

, anticipating that , contrary to the EPA’s assumptions, some storage vessels may need to install

controls

. The commenter also suggests that facilities subject to subpart OOO voluntarily update the data in the 2005 NEI for storage vessels. Response 7. 2

. 2 : The EPA agrees with the commenter that three years some storage vessels may need to install controls and th at therefore should be provided to identify and install any new controls required to comply with the revised storage vessel requirements. We have revised the final rule to reflect this.

Comment 7.2. 3 : Commenter 46 states that in the EPA’s beyond

- the

- floor analysis for continuous process vents , it assumed that facilities have the ability to treat scrubber wastewater

on

- site . However, the commenter states that this is not the case, and most affected facilities

would need to send this waste to a wastewater tr eatment facility

. The commenter believes the EPA should include these costs in its analysis. The commenter also notes that the wastewater41

treatment costs the EPA did include were inaccurate, in that it used a price from the EPA Control Cost Manual per 100 gallons of wastewater, but attributed this cost to each 1,000 gallons. The

comment er asks that the EPA update its analysis to include the correct wastewater treatment

costs. Response 7. 2

. 3 : The EPA has revised its beyond

- the

- floor calculations to incorpor ate the new data submitted by the commenter. We note, however, that the “per 100 gallons of wastewater” that the commenter refers to is a typo on page 1

- 40 of the EPA Control Cost Manual. The example calculation on this page does not work if 100 gallons is used, and a correct reference to 1000 gallons is listed in a footnote on page 1

- 42.

Comment 7. 2. 4 : Commenter 37 states that it has a facility, which is regulated by subpart OOO, but was mistakenly not included in the EPA analyses for that source category . The commenter provided the pertinent NEI data for the facility for the year 2011 and also a summary of the capacity and vapor pressure of the storage tanks regulated by subpart OOO. Response 7. 2

. 4 : The EPA thanks the commenter for identifying themselves as being subject to the APR MACT standards and has revised the final risk modeling file to include the commenter’s facility.



### 7. 3 Source Category Specific Comments

– Polycarbonate Production

Comment 7. 3 .1: Regarding the proposed revis ion to the PC equipm ent leak standards,

c ommenter 31 concurs with the EPA’s proposal to require instrument monitoring under subpart UU, with the exception of connectors, provided the EPA also finalizes the proposed compliance timeline of one year for existing sources in 40 CF R 63.1102(b). Response 7. 3

. 1 : We thank the commenter for this feedback

.



### 7.4 Subpart Specific Comments

– Subpart YY (GMACT)

Comment 7.4.1: Commenter 29 notes that subpart YY references subpart SS for its closed vent system and control device requirement f or the AMF and PC source categories and requests that the EPA clarify whether or not the various SSM provisions, including the excused excursion provisions, of subpart SS apply to the AMF and PC source categories. The commenter suggests that a paragraph co uld be added to subpart YY to provide for any exceptions or alternatives to 40 CFR part 63, subpart SS. Response 7. 4

. 1 : The EPA agrees with the commenter that the language of subpart YY should be clarified to explicitly state that the excused excursion lan guage of subpart SS does not apply to AMF and PC source, in keeping with the SSM exemption removal for these source categories. Accordingly, we have revised 40 CFR 63.1108(b) (1) to clarify that excused excursions are not allowed for the AMF and PC source c ategories

.

Comment 7.4.2: Commenter 42 requests that the EPA clarify that while several sections of the GMACT would be modified under this proposal, comments will be requested and considered on these provisions as if they were proposed for the first time if the EPA proposes to make these provisions applicable to any other source categories. The commenter also suggests

that to make this clear in 40 CFR 63.1108(b)(4)(ii), the proposed sentences added to this paragraph that apply to the AMF and PC source cate gories be put in a separate paragraph.42

Response 7. 4

. 2 : The EPA agrees with the commenter that opportunity to comment on revisions to other source categories regulated by the GMACT will be provided. With regard to the commenter’s suggestion for 40 CFR 63.11 08(b)(4)(ii), we have revised this paragraph to clarify which provisions only apply to the AMF and PC source categories.

Comment 7.4.3: Commenter 29 states that similar to the requirements for ethylene sources in subpart YY, subpart YY should contain excl usions from the rule for certain equipment for the other source categories regulated by that subpart

. Response 7.4. 3 : The EPA disagrees that the suggested equipment should be exempted from the requirements of the AMF and PC MACT standards. The commenter f ailed to provide rationale for why this equipment should no longer be subject to the rule, and so the EPA has no basis for which to comply with the commenter’s suggestion.

Comment 7.4.3 : Commenter 29 requests that the EPA clarify in 40 CFR 63.1103 Tables

5 and 6 that halogen reduction device requirements for process vents only apply to halogenated vent streams that are combusted. The commenter also requests that the EPA correct an incorrect reference in Table 5, Item 5 to 40 CFR 63.982(e) and 63.993(c) rat her than 40 CFR 63.990(c).

The commenter notes that the requirements for a process vent or combined vent stream with a TRE greater than 2.7 but less than 4.0 should point to the monitoring requirements for absorbers, condensers, and carbon adsorbers used a s final recovery devices to maintain the TRE rather than those used to meet a weigh t

- percent emission reduction. The commenter adds that the reference

in this item to 40 CFR 63.995(c) is not needed because it was intended to apply to other control

devices needed to meet a weight

- percent emission reduction rather than to maintain a TRE value. Response 7. 4

. 3 : The EPA agrees with the commenter and has corrected the errors

.

Comment 7.4.4 : Commenter 29 requests that the EPA add overlap provisions to subpart

YY for all source categories with equipment leaks that may potentially be subject to 40 CFR part 60, subpart VVa. The commenter notes that overlap with subpart VVa is not addressed in subpart YY nor is overlap with subpart UU (which is referenced in YY) addre ss ed in subpart VVa. The commenter also requests that for equipment that is subject to 40 CFR part 60, subpart VV or VVa but is not subject to the equipment leak provisions of subpart YY, an owner or operator may choose to comply with subpart YY for all su ch equipment in the process unit so long as connector monitoring is still performed according to subpart VVa. Response 7. 4

. 4 : The EPA disagrees with the commenter that the EPA should provide overlap provisions for subpart VVa. As certain provisions of subp art VVa are currently stayed, we do not believe it is appropriate at this time to make any determinations regarding the equivalency of subpart VVa and the equipment leak provisions of subpart TT and UU (as referenced by subpart YY )

.

Comment 7.4.5 : Comment er 29 requests that the EPA change all references to “a range” or “operating range” in subpart YY to “operating limit” when in reference to subpart SS. The commenter states that the term “operating limit” is more technically correct. The commenter also

req uests that the EPA revise 40 CFR 63.1107(e)(2)(i) and (ii) to say “as described in Method 21” rather than “as detected by Method 21.” The commenter states the suggested revised language appears to be the intent of the EPA.43

Response 7. 4

. 5 : The EPA agrees w ith the commenter on Method 21 and the final rule reflects the commenter’s suggested language. With regards to “range” vs “limit,” we believe that the existing language in subpart YY is clear and does not need to be revised

.

Comment 7.4.6 : Commenter 29 re quests that the EPA correct several citation errors.

These include: in 40 CFR 63.1106(a)(1 1 ), change reference from 40 CFR 63.1 1 10(a)(3) to 40

CFR 63.1110(a)(4) for the Notification of Compliance Status requirements; in 40 CFR 63.1106(a)(12), change refere nce from 40 CFR 63.1110(a)(4) to 40 CFR 63.1110(a)(5) for the Periodic Report requirements; in 40 CFR 63.1106(a)(13), change reference from 40 CFR 63.139(e)(1)(ii) to 40 CFR 63.139(c)(1)(ii); and in 40 CFR 63.1106(c)(6), correct the apparent

incorrect refe rence to 40 CFR 63.119(e)(1) or (e)(2). Response 7.4.6 : The EPA has corrected the identified errors in the final rule.

Comment 7.4.7 : Commenter 33 requests that the EPA revise 40 CFR 63.1107(f)(1) to

also list PRDs that “ vent to a process ” and suggests a rephrasing of the requirement to be less clumsy. The commenter suggests the provision state “A list of identification numbers for pressure relief devices that vent to a closed vent system and control device or to a process, under the provisions in paragrap h (e)(4) of this section.”

The c ommenter also requests that the EPA revise 40 CFR 63.1110(a) to clarify that the reports required in paragraph 40 CFR 63.1110(a)(9) are required in addition to the other reports required under 40 CFR 63.1110(a). The c omment er also requests that the EPA clarify that there is only one Notification of Compliance Status (N O CS) required by 40 CFR 63.1110(d)(1) and not a separate one for PRDs. The commenter suggests that the N O CS for PRDs be designated a supplement to the N O CS, wh ich would alleviate potential confusion, and one N O CS would continue to be required. Response 7. 4

. 7 : The EPA agrees with the commenter and the final rule has been revised

to reflect the commenter’s suggest ions

.44



## 8.0 Other Comments

Comment 8.1: Commenter 35 supports the additional provisions added to the rule for a more stringent LDAR program for the AMF and PC source categories, more stringent control thresholds for storage vessel s at new sources in the APR source category and the establishment

of standa rds for previously unregulated emission points in the AMF and APR source categories.

Commenter 37 supports the proposed clarification in 40 CFR 63.1413(a)(2) stating that representative conditions for performance tests do not include periods of startup or shutdown. Response 8.1: We acknowledge the commenters ’ support for these additional standards and clarification of the standards

.

Comment 8.2: Commenters 31, 37, 42, and 46 state that they adopt and incorporate the comments of the SSM Coalition by refere nce. Commenters 33 and 37 state that they endorse the comments submitted by the ACC. Response 8.2: We have addressed all of the comments from ACC and the SSM Coalition.

Comment 8. 3 : Commenter 36 states that the EPA should create a community complaint

mec hanism that ensures citizen complaints concerning air pollution receive an immediate response, in which the EPA commits to initiate an investigation and provide a publicly available report of the investigation results, including whether it leads to an enfo rcement action, within 7 days. Response 8. 3 : The EPA takes citizen pollution complaints seriously and is committed to responding to complaints. We invite you to help us protect our nation's environment by identifying and reporting environmental violations. The EPA's Report an Environmental Violation website provides a way for you to report suspected environmental violations. ( http://www.epa.gov/compliance/complaints/moreinfor.html )

A ssuring compliance with our nation's environmental laws is one of EPA's primary commitments. In carrying out this responsibility, we use many different approaches. One approach is to seek help from you by asking you to provide EPA with information about

po tentially harmful environmental activities in your communities and workplaces. Reports from the public have led to state and federal enforcement cases and ultimately served environmental protection well.

Comment 8.4 : Commenter 36 asserts the EPA must proh ibit routine flaring, set a cap to limit special flaring, ensure its efficiency and monitor flaring. The c ommenter claims that since the original MACT s tandards were set, the EPA now has substantial new information on flaring and its impacts (for example, EPA’s 2012 peer

- reviewed study Parameters for Properly Designed and Operated Flares) and must apply this new information in this rulemaking. The commenter claims that the changes in flaring use and knowledge about flaring are developments that must be

cons idered under CAA section 112(d)(6) and that flares without proper limits violates National

Lime Association . The commenter further states that the EPA has provided no valid basis to distinguish between flares at facilities like refineries and chemical plan ts and the sources under review here, and the EPA must take action to apply the new data on flaring in his rulemaking. Considering the new information the EPA now has that flares are less efficient than previously understood, the EPA should consider prohib iting the use of flaring, ensure less reliance on flaring, requiring flare gas recovery systems, requiring improved flare monitoring and ensuring the proper operating parameters are set. The commenter also notes that there is evidence that45

reduced flaring saves money by capturing and rerouting hydrocarbons for reprocessing and use.

Commenter 31 notes that they are unaware of any member facilities that use flares to control

HAP emissions i n any of the source categories. Response 8. 4 : The EPA is not at this t ime making changes to the flare provisions for the source categories addressed in this action. It is likely that, rather than to take commenter 36 ’s suggestion to simply adopt new flare requirements in the final rule, we would need to undertake

another rou nd of proposed rulemaking and solicit comment on any amendments to the flare provisions for these NESHAP, in order to meet our procedural obligations under CAA section 307(d). As noted in the preamble to the proposed rule, the EPA has recently begun studyi ng the performance of flares to control HAP emissions, as governed by the EPA’s General Provisions at 40 CFR 63.11(b), in other contexts outside of this rulemaking. See 79 FR 1715. Additionally, in the preamble the EPA also requested information such as: “ Prevalence of flaring; number and types of flares used; waste gas characteristics such as flow rate, composition and heat content; assist gas characteristics such as target assist gas to waste gas ratios and minimum

assist gas flow rates; use of flare gas recovery and other flare minimization practices; and existing flare monitoring systems. ” We note that commenter 36 has not provided us with any of the information requested for these specific source categories, and the information provided by

commenter 31 indicates that none of the facilities in these source categories may use flares to control emissions subject to the AMF, PC, or APR MACT standards. Therefore, we are not at this time prepared to finalize any changes to the currently applicable regulations pertaining to the performance of flares in the AMF, PC, and APR source categories, but we may explore whether to revise flare requirements in the future, if we conclude that new requirements are warranted and would be applicable to subject source categorie s.