NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR 

POLLUTANTS FOR POLYVINYL CHLORIDE AND 

COPOLYMERS PRODUCTION

SUMMARY OF PUBLIC COMMENTS AND RESPONSES

U.S. Environmental Protection Agency

Office of Air Quality Planning and Standards

Sector Policies and Programs Division

Research Triangle Park, North Carolina 27711

February 2012
ii

The primary contact regarding questions or comments on this document is:

Jodi Howard (919) 541-4607

U.S. Environmental Protection Agency

OAQPS/Sector Policies and Programs Division

Refining and Chemicals Group (E143-01)

Research Triangle Park, North Carolina 27711

Email: howard.jodi@epa.gov
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TABLE OF CONTENTS

Section Page No.

1.0 INTRODUCTION ........................................................................................................... 1-1

2.0 LIST OF COMMENTERS .............................................................................................. 2-1

3.0 AFFIRMATIVE DEFENSE............................................................................................ 3-1

4.0 APPLICABILITY............................................................................................................ 4-8

5.0 AREA SOURCES.......................................................................................................... 5-11

6.0 BEYOND-THE-FLOOR ANALYSIS .......................................................................... 6-12

7.0 EQUIPMENT LEAKS................................................................................................... 7-15

7.1 Compliance and Monitoring .............................................................................. 7-15

7.2 Emission Limits, Operating Limits, and Work Practice Standards ................... 7-17

8.0 HEAT EXCHANGE SYSTEMS................................................................................... 8-18

9.0 OTHER EMISSION SOURCES ................................................................................... 9-20

10.0 PROCESS VENTS ...................................................................................................... 10-22

10.1 Compliance and Monitoring ............................................................................ 10-22

10.1.1 General Support of Process Vent Floors and Compliance................... 10-22

10.1.2 General Concerns with Process Vent Floors and Compliance ............ 10-23

10.1.3 Closed Vent Systems and Control Device Bypass .............................. 10-24

10.1.4 CEMS/CPMS....................................................................................... 10-31

HCl CEMS....................................................................................................... 10-34

VCM CEMS..................................................................................................... 10-36

CPMS – Selection of Monitored Parameters................................................... 10-41

CPMS - Miscellaneous .................................................................................... 10-43

10.1.5 Stack Testing........................................................................................ 10-49

10.2 Emission Limits, Operating Limits, and Work Practice Standards ................. 10-56

10.3 MACT Floor .................................................................................................... 10-58

11.0 RESIN.......................................................................................................................... 11-59

12.0 STORAGE VESSELS ................................................................................................. 12-60

13.0 WASTEWATER.......................................................................................................... 13-68

13.1 Compliance and Monitoring ............................................................................ 13-68

13.1.1 Relaxed testing for wastewater streams............................................... 13-68

13.1.2 Point of determination (POD) / Intermittent wastewater..................... 13-71

13.1.3 Rule Clarifications Requested.............................................................. 13-71

13.1.4 Sampling/Analysis Methods................................................................ 13-73

13.1.5 General................................................................................................. 13-75

13.2 MACT Floor .................................................................................................... 13-77
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14.0 COMPLIANCE DATES.............................................................................................. 14-79

15.0 DEFINITIONS AND TERMINOLOGY..................................................................... 15-80

16.0 EMISSION LIMITS, OPERATING LIMITS, AND WORK PRACTICE STANDARDS

16-89

17.0 GENERAL SUPPORT OF OTHER COMMENTERS ............................................... 17-90

18.0 IMPACTS .................................................................................................................... 18-92

18.1 General............................................................................................................. 18-92

18.2 Air .................................................................................................................... 18-93

18.3 Cost .................................................................................................................. 18-95

18.4 Non-Air Quality Health, Environmental, and Energy ..................................... 18-96

19.0 MACT FLOOR, GENERAL ....................................................................................... 19-99

20.0 REGULATED POLLUTANTS................................................................................. 20-101

21.0 REGULATORY OVERLAP..................................................................................... 21-101

22.0 RESIN MORPHOLOGY........................................................................................... 22-103

23.0 RULE......................................................................................................................... 23-104

23.1 General........................................................................................................... 23-104

23.2 Format............................................................................................................ 23-104

24.0 STARTUP, SHUTDOWN, AND MALFUNCTIONS.............................................. 24-105

25.0 STATUTORY AUTHORITY ................................................................................... 25-112

26.0 SUBCATEGORIES................................................................................................... 26-113

27.0 VARIABILITY.......................................................................................................... 27-113

28.0 CROSS REFERENCES AND CITATIONS............................................................. 28-117

29.0 DOCKET ................................................................................................................... 29-118

30.0 INFORMATION GATHERING ............................................................................... 30-120

31.0 STATUTORY AND EXECUTIVE ORDERS.......................................................... 31-120

32.0 NOTIFICATIONS, RECORDKEEPING, AND REPORTS..................................... 32-122

33.0 MISCELLANEOUS .................................................................................................. 33-128
1-1

1.0 INTRODUCTION

On May 20, 2011, EPA proposed National Emission Standards for Hazardous Air 

Pollutants for Polyvinyl Chloride and Copolymers Production. This document contains 

summaries of the public comments that EPA received on the proposed standards. In this 

document and in the preamble to the final rule, EPA responds to the public comments. Copies of 

all comments submitted are available at the EPA docket Center Public Reading Room. Comment 

letters and transcripts of the public hearings are also available electronically through 

http://www.regulations.gov by searching Docket ID EPA-HQ-OAR-2002-0037.
2-1

2.0 LIST OF COMMENTERS

The EPA received 40 comment letters on the proposed National Emission Standards for 

Hazardous Air Pollutants for Polyvinyl Chloride and Copolymers Production after the rule 

proposal. Comments from two public hearings held on June 7, 2011 and June 9, 2011 are also 

included in this document. All comment letters and the two public hearing transcripts are 

contained in Docket EPA-HQ-OAR-2002-0037. The commenter, affiliation and item number in 

Docket EPA-HQ-OAR-2002-0037 are listed in Table 2-1. The public hearing commenter, 

affiliation, and item number are listed in Table 2-2. A list of acronyms and units of measure used 

in this document appears after the list of commenters.

Table 2-1. Public Comments Received After the Proposed Rule for National Emission 

Standards for Hazardous Air Pollutants for Polyvinyl Chloride and Copolymers 

Production, Proposed Rule Docket EPA-HQ-OAR-2002-0037

Commenter Identification Code Commenter and Affiliation

EPA-HQ-OAR-2002-0037-0118 Jean-Cyril Walker, Keller and Heckman LLP

EPA-HQ-OAR-2002-0037-0120 G. Vinson Hellwig, Co-Chair, Michigan and Robert H. Colby, 

Co-Chair, Chattanooga, Tennessee, Air Toxics Committee, 

National Association of Clean Air Agencies (NACAA)

EPA-HQ-OAR-2002-0037-0121 John S. Lyons, Director, Energy and Environment Cabinet, 

Department for Environmental Protection, Kentucky Division

for Air Quality

EPA-HQ-OAR-2002-0037-0122 Russell G. Grizzle, Chief Operating Officer, Mannington 

Mills, Inc.

EPA-HQ-OAR-2002-0037-0124 Rich Walker, President and CEO, American Architectural 

Manufacturers Association (AAMA)

EPA-HQ-OAR-2002-0037-0125 Bruce Hollands, Uni-Bell PVC Pipe Association

EPA-HQ-OAR-2002-0037-0126 Bill Gulledge, Senior Director, Chemical Products & 

Technology Division, American Chemistry Council (ACC) 

Vinyl Chloride Health Committee (VCHC)

EPA-HQ-OAR-2002-0037-0127 Michael Cudahy, Codes and Training Specialist, Plastic Pipe 

and Fittings Association (PPFA)

EPA-HQ-OAR-2002-0037-0131 Paul A. Yost, Vice President Energy and Resources Policy, 

National Association of Manufacturers (NAM)

EPA-HQ-OAR-2002-0037-0133 Hal Bozarth, Executive Director, Chemistry Council of New 

Jersey (CCN)

EPA-HQ-OAR-2002-0037-0134 Kenneth G. Akins, Director Corporate Environmental, Georgia 

Gulf Corporation (GGC)

EPA-HQ-OAR-2002-0037-0135 Marie R. Martinko, Director, Industry Affairs, Environment & 

Health, Society of the Plastics Industry, Inc. (SPI)

EPA-HQ-OAR-2002-0037-0136 Kevin D. Ott, Coordinator, Flexible Vinyl Alliance

EPA-HQ-OAR-2002-0037-0137 David Friedman, Senior Director, Regulatory Affairs, National 

Petrochemical & Refiners Association (NPRA)
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Commenter Identification Code Commenter and Affiliation

EPA-HQ-OAR-2002-0037-0138 William L. Kovacs, Senior vice President, Environment, 

Technology & Regulatory Affairs, U.S. Chamber of 

Commerce

EPA-HQ-OAR-2002-0037-0139 Mark D. Pettegrew, Global Director, Environmental Health & 

Safety (EH&S) - Product Stewardship, PolyOne Corporation

EPA-HQ-OAR-2002-0037-0140 Judith R. Morgan, Chair, Environmental Laboratory Advisory 

Board (ELAB)

EPA-HQ-OAR-2002-0037-0141 Lorraine Krupa Gershman, Director, American Chemistry 

Council (ACC)

EPA-HQ-OAR-2002-0037-0142 Bob Elam, The Dow Chemical Company

EPA-HQ-OAR-2002-0037-0143 Tokesha M. Collins, Kean Miller LLP on behalf of Louisiana 

Chemical Association (LCA)

EPA-HQ-OAR-2002-0037-0144 Jim Hodges, Site Manager, Shintech

EPA-HQ-OAR-2002-0037-0145 Christopher G. Mundschenk, Executive Director, 

Wallcoverings Association (WA)

EPA-HQ-OAR-2002-0037-0146 Peter L. de la Cruz and Jean-Cyril Walker, Keller and 

Heckman LLP on behalf of Vinyl Institute, Inc.

EPA-HQ-OAR-2002-0037-0147 Judith D. Nordgren, Managing Director, Chlorine Chemistry 

Division, American Chemistry Council (ACC)

EPA-HQ-OAR-2002-0037-0148 Stephen P. Risotto, Senior Director, Phthalate Esters Panel, 

American Chemistry Council (ACC)

EPA-HQ-OAR-2002-0037-0149 Lauren P. Alterman, Vice President, Environment, Health and 

Safety, Saint-Gobain Corporation

EPA-HQ-OAR-2002-0037-0150 James Pew, Earthjustice

EPA-HQ-OAR-2002-0037-0151 Mary P. Bachynsky, Manager, Corporate Air Program, 

Formosa Plastics Corporation, U.S.A.

EPA-HQ-OAR-2002-0037-0152 Lloyd R. Cress, Jr., Dinsmore & Shohl LLP on behalf of 

Kentucky Association of Manufacturers (KAM)

EPA-HQ-OAR-2002-0037-0153 Barry Christensen, Manager Air Quality, Occidental Chemical 

Company (OCC)

EPA-HQ-OAR-2002-0037-0154 Mark D. Pettegrew, Global Director, Environmental Health & 

Safety (EH&S) - Product Stewardship, PolyOne Corporation

EPA-HQ-OAR-2002-0037-0155 Dean Thompson, President, Resilient Floor Covering Institute

EPA-HQ-OAR-2002-0037-0156 Christina T. Wisdom, Vice President & General Counsel, 

Texas Chemical Council

EPA-HQ-OAR-2002-0037-0157 Chris Farley, Environmental Engineer, Wacker Chemical 

Corporation

EPA-HQ-OAR-2002-0037-0158 Bertram M. Lederer, Executive Vice President, Teknor Apex 

Company

EPA-HQ-OAR-2002-0037-0159 Therese M. Cirone, Vice President of Health, Environment, 

Safety and Security, The Chlorine Institute (CI)

EPA-HQ-OAR-2002-0037-0160 Kevin Bloomer, Senior Environmental Engineer, Westlake 

Chemical Corporation

EPA-HQ-OAR-2002-0037-0161 Jerry Y. Huntley, President and CEO, Vinyl Siding Institute 

(VSI)

EPA-HQ-OAR-2002-0037-0162 Randall W. Marvel, Vice President- Supply Chain/Strategic 

Initiatives, RJF International Corporation
2-3

Commenter Identification Code Commenter and Affiliation

EPA-HQ-OAR-2002-0037-0163 

(Duplicate of 0126)

Bill Gulledge, Senior Director, Chemical Products & 

Technology Division, American Chemistry Council (ACC) 

Vinyl Chloride Health Committee (VCHC)

EPA-HQ-OAR-2002-0037-0164 Mark A. Biel, Executive Director, Chemical Industry Council 

of Illinois (CICI)

Table 2-2. Public Comments Received During the June 7, 2011 and June 9, 2011 Public 

Hearings on the National Emission Standards for Hazardous Air Pollutants for Polyvinyl 

Chloride and Copolymers Production, Proposed Rule

Commenter Identification Code Commenter and Affiliation

PH-BR-0001 Otis Sistrunk, PolyOne Corporation

PH-BR-0002 Richard Krock, Vinyl Institute

PH-BR-0003 Mary Bachynsky, Formosa Plastics Corporation

PH-BR-0004 Christine Bennett, Mossville Environmental Action Now 

(MEAN)

PH-BR-0005 Delma Bennett, Mossville Environmental Action Now 

(MEAN)

PH-BR-0006 C. Dean Thompson, Resilient Floor Covering Institute

PH-BR-0007 Allen Blakey, Vinyl Institute

PH-BR-0008 Beverly S Smiley, Solutions Through Science

PH-BR-0009 Henry Graham, Jr., Louisiana Chemical Association

PH-BR-0010 Wilma Subra, Louisiana Environmental Action Network 

(LEAN) and the Lower Mississippi River Keeper

PH-BR-0011 Monique Hardin, Advocates for Environmental Human Rights 

and Mossville Environmental Action Now (MEAN)

PH-H-0001 Otis Sistrunk, PolyOne Corporation

PH-H-0002 Richard Krock, Vinyl Institute

PH-H-0003 Mary Bachynsky, Formosa Plastics Corporation

PH-H-0004 Bruce Hollands, PVC Pipe Association

Many of the public comments and the Agency‘s responses are in the preamble to the final 

standards, and are not repeated here. Table 2-3 provides cross-references to the preamble to 

identify subjects that were commented on and are responded to in the preamble rather than this 

document.

Table 2-3. Comments That Are Responded To In the Preamble to the Final PVC Rules

Topic Subtopic

Commenters who 

commented on the 

topic

See the following Preamble 

sections for responses
2-4

Topic Subtopic

Commenters who 

commented on the 

topic

See the following Preamble 

sections for responses

Affirmative 

defense 0150, 0153 V.L

Area sources 0141, 0149, 0153 V.E.2 and V.H.

Beyond-the-floor 

analysis

PH-BR-003,0144, 

0146, 0153 V.F.2, V.F.6, V.M and VI

Compliance dates 0144, 0146 IV.B, IV.F, and V.A

Definitions and 

terminology

0142, 0144, 0153, 0146 V.A, V.C, V.F.1

Emission limits, 

operating limits, 

and work practice 

standards

0150 V.C

Equipment leaks Compliance and 

monitoring

0146 V.E.2 and V.F.2

Heat exchange 

systems

0134, 0137, 0141, 

0142, 0143, 0144, 

0146, 0153, 0160

V.F.5

Impacts General 0155 VI

Cost 0134, 0142, 0144, 

0153, 0157

V.E.2, V.H, V.J, and VI

Economics 0124, 0126, 0131, 

0135, 0136, 0138, 

0139, 0142, 0144, 

0147, 0151, 0155, 

0158, 0161, PH-BR0003, PH-BR-0006

V.J and V.K

Information 

gathering

0134, 0151, 0144 V.D, V.E.2

MACT floor 0126, 0131, 0134, 

0135, 0137, 0144, 

0146, 0150, 0153, 

0157, PH-BR-011

V.D, V.E.2 and V.J

Miscellaneous PH-BR-007, PH-H0002, PH-BR-0002, 

PH-BR-0005, PH-BR0011, 0153

V.B and V.K

Process vents Compliance and 

monitoring

Closed vent 

systems and 

control device 

bypass

CEMS/CPMS

Stack testing

0134, 0139, 0141, 

0142, 0143, 0146, 0153

V.C, V.E.2, V.F.1, V.G, V.J 

and IV.J
2-5

Topic Subtopic

Commenters who 

commented on the 

topic

See the following Preamble 

sections for responses

Emission limits, 

operating limits, and 

work practice 

Standards

Dioxin/Furan 

limits

0134, 0144, 0142, 

0146, 0141

V.E.2

MACT floor 0118, 0134, 0143, 

0144, 0146, 0151, 

0153, 0157, 0160

V.D and V.E.2

Vent gas absorbers PH-BR-0001, 0139, 

0143, 0142

V.D and V.E.2

Regulatory 

overlap

0134, 0141, 0142, 

0146, 0153

V.B

Regulated 

pollutants

0137, 0146, 0150, 

0153, PH-H-0001, PHBR-0004, PH-BR0010, PH-BR-0011

V.C

Resin 0118, 0134, 0139, 

0142, 0143, 0144, 

0146, 0148, 0151, 0153

V.C , V.E.2, and V.F.2

Rule comments PH-H-0002, 0141, and 

0157

V.B and V.D

Startup, 

shutdown, and 

malfunctions

General comments, 

PRD‘s, and bypass

0134, 0141, 0142, 

0144, 0146, 0153, 0159

V.F.2 and V.J

Statutory and 

executing orders

0142 V.J and V.K

Subcategories 0134, 0137, 0139, 

0142, 0143, 0144, 

0146, 0151, 0153, 

0157, PH-H-0001

V.D

Variability PH-BR-0002, PH-BR0003, 0134, 0144, 0146V.D and V.E.2

Wastewater Compliance and 

monitoring

Relaxed testing for 

wastewater 

streams

Point of 

Determination 

(POD) / 

Intermittent 

wastewater

0134, 0141, 0142, 

0143, 0144,0146, 0153, 

0157

V.C and V.F.4

MACT floor 0134, 0143, 0144, 

0146, 0153

V.E.2
2-6

List of Acronyms and Abbreviations

Acronyms

ACC American Chemistry Council

ACI activated carbon injections

ALAPCO Administration of Local Air Pollution Control Officials

APC air pollution control 

API American Petroleum Institute

ASME American Society of Mechanical Engineers

BWON Benzene waste operations NESHAP

CAA Clean Air Act 

CCNJ Council of New Jersey

CDD/CDF chlorinated dibenzo-dioxins and furans 

CDF chlorinated dibenzofuran

CEMS continuous emission monitoring system

CERCLA Comprehensive Environmental Response, Compensation and Liability Act

CFR Code of federal Regulations

CMS continuous monitoring system

CO carbon monoxide

CPMS continuous parameter monitoring system

DQO data quality objective

dscm dry standard cubic meter

ECD electron capture detector

EDC ethylene dichloride

EO Executive Order

EPCRA Emergency Planning and Community Right to know Act

ERT Electronic Reporting Tool

FIA flame ionization analyzer

FIP Federal implementation plan

FR Federal Register

ft3cubic feet

FTIR Fourier Transform Infrared Spectroscopy

GACT Generally Available Control Technologies or management practices

GC FID Gas chromatography flame ionization detector 

HAP hazardous air pollutants

HCl hydrogen chloride 

HON Hazardous Organic NESHAP

ICR Information Collection Request

IRIS Integrated Risk Information System

LDAR leak detection and repair

l/min liters per minute
2-7

m

3

cubic meters

MACT Maximum Achievable Control Technology

MON Miscellaneous Organic Chemical Manufacturing NESHAP

MQO measurement quality objective

MS Mass Spectroscopy

NAM National Association of Manufacturers

NESHAP National Emission Standards For Hazardous Air Pollutants

NOCS Notification of Compliance Status

NPDES National Pollution Discharge Elimination System

NSPS New Source Performance Standard

OCC Occidental Chemical Corporation/OxyVinyls

OLD organic liquids distribution

OSHA Occupational Safety and Health Administration

PEG polyethylene glycol

POD point of determination

ppm parts per million

ppmv parts per million by volume 

ppmvd parts per million by volume on a dry basis

ppmw parts per million by weight 

PRD pressure relief device

PVC polyvinyl Chloride and Copolymers

PVCPU PVC Production Process Unit

QC quality control

RFCI Resilient Floor Covering Institute

ROL reactor opening loss

RQ Reportable Quantity

RTD resistive thermal device

RVCM residual vinyl chloride monomer

SAP sampling and analysis plan

SIP State Implementation Plan

SPI Society of the Plastics Industry

SSM startup, shutdown and malfunctions

STAPPA State And Territorial Air Pollution Program Administrators

THC total hydrocarbon

tpy tons per year 

TO thermal oxidizer

TOH total organic hazardous air pollutants

TOHAP total organic hazardous air pollutants

UPL Upper Prediction Limit

VC vinyl chloride

VCHC Vinyl Chloride Health Committee

VCM vinyl chloride monomer
2-8

VGA vent gas absorber

VI Vinyl Institute

VOC volatile organic compound

WW wastewater

WWW World Wide Web 
3-1

3.0 AFFIRMATIVE DEFENSE

Comment 3.1: The commenter (0153) contended that if an event associated with safety 

practices causes a violation and should happen to meet the affirmative defense criteria for 

malfunctions, the defense should be available. 

Response to comment 3.1: Both the proposed and final rule provide, as suggested by the 

commenter, that a facility may assert an affirmative defense for a bypass or other event caused 

by a malfunction that meets the affirmative defense criteria for malfunctions in §63.11895. This 

is discussed in more detail in section V.F.2 of the final rule preamble. 

Comment 3.2: One commenter (0153) requested that EPA amend the first paragraph of 

section 63.11895 to reference enforcement of the ―standards set forth in section 63.11880(a),‖ 

not ―63.11880‖. They argue that the extensive elements of the affirmative defense in subsections 

(a)(1) - (9) should not be required in order to defend against alleged violations of operating limits 

and other standards referenced in subsections 63.11880(b) and (c), as well as startup and 

shutdown events which should not be included in §63.11880(a), that do not also involve an 

exceedance of an emissions limit specified in subsection 63.11880(a). 

Response to comment 3.2: The commenter incorrectly asserts that the elements of the 

affirmative defense are ―required in order to defend against alleged violations of operating limits 

and other standards referenced in subsections 63.11880(b) and (c).‖ Section 63.11880 specifies 

the emissions limits, operating limits and standards that the owner or operator must meet. 

§63.11880(a) states that the owner or operator ―must comply with each emission limit and 

standard‖ specified in the rule. §63.11880(b) specifies that the owner or operator must ―establish 

an operating limit for each operating parameter required to be monitored in §§63.11925‖. 

§63.11880(c) specifies that the owner or operator must ―comply with the emission limits and 

standards specified in §§63.11910 through 63.11980.‖ In establishing this affirmative defense 

provision, EPA is not removing or restricting any existing ability of source owners or operators 

to defend against alleged violations of any kind. Instead, we are promulgating an affirmative 

defense to civil penalties that may be used in addition to any existing defenses that a source 

owner or operator may have, and we are setting criteria for the new affirmative defense. The 

commenter‘s request to revise section 63.11895 to be limited to ―standards set forth in section 

63.11880(a)‖ rather than ―63.11880‖ would result in a more limited availability of the 
3-2

affirmative defense and not fewer requirements for asserting an affirmative defense, as the 

commenter seems to assume. We continue to believe the affirmative defense should be available 

for all these standards. 

Comment 3.3: One commenter (0142) contends that some of the requirements in 

subsections (a)(1) - (9) are unreasonable, difficult to demonstrate, and subject to varying 

interpretation. Two commenters (0141, 0142) contended that the affirmative defense provisions 

that cover malfunctions are too burdensome

Response to comment 3.3: EPA disagrees with comments that criticize the affirmative 

defense criteria as being unreasonable, difficult to demonstrate, and subject to varying 

interpretations. EPA believes that courts are well equipped and often do evaluate and apply the 

type of criteria set forth is the affirmative defense. Many of the conditions were modeled after 

the conditions of the affirmative defense in EPA‘s SIP SSM policy, which several states have 

adopted into their SIPs. (See, e.g., State Implementation Plans: Policy Regarding Excessive 

Emissions During Malfunctions, Startup, and Shutdown (Sept. 20, 1999); Policy on Excess 

Emissions During Startup, Shutdown, Maintenance, and Malfunctions (Feb. 15, 1983)). We do 

not have any indication that parties to enforcement proceedings have had any significant 

difficulties applying the terms of these SIP affirmative defenses. In addition, EPA‘s view is that 

use of consistent terms in establishing affirmative defense regulations and policies across various 

CAA programs will promote consistent implementation of those rules and policies. 

EPA addresses the burden associated with an affirmative defense by providing the public 

with an estimate of the relative magnitude of the burden associated with an assertion of the 

affirmative defense adopted by a source (see section V.L of the preamble). EPA is also providing 

administrative adjustments to the ICR that include an estimate of the burden of the notification, 

recordkeeping, and reporting requirements associated with the assertion of the affirmative 

defense. We note that the burden estimate for affirmative defense is less than the burden estimate 

for the formerly required SSM plan. 

Comment 3.4: One commenter (0141) stated that EPA was silent on its rationale for 

excluding periods of startup and shutdown from the proposed affirmative defense and argued 

that if EPA refuses to provide separate emission limitations for periods of startup and shutdown, 

and if in fact excess emissions during these periods cannot reasonably be avoided, there is no 
3-3

reason for EPA not to provide an affirmative defense to the source for periods of startup, 

shutdown and malfunction.

Response to comment 3.4: EPA is promulgating the affirmative defense for malfunctions 

only, not for periods of startup and shutdown except that the affirmative defense would be 

available if there were a malfunction that occurs during a period of startup or shutdown . EPA 

believes that malfunction events should be treated differently than periods of startup and 

shutdown, which are predictable and routine aspects of a source‘s operations. Because startup 

and shutdown periods are part of a source‘s normal operations, the same approach to compliance 

with, and enforcement of, applicable emissions standards during those periods should apply as 

otherwise applies during a source‘s operations. Further, periods of startup and shutdown – but 

not malfunctions -- are taken into account when establishing section 112 emissions standards. 

For these reasons, EPA believes it is appropriate to apply the affirmative defense based on the 

occurrence of a malfunction and not based on startup or shutdown status. Furthermore, the 

commenter as provided no information to suggest that excess emissions during startup or 

shutdown cannot be avoided.

Comment 3.5:. One commenter (0142) argued that work practice standards that require 

the owner/operator to stop the emissions, to stop the malfunction, and to return to normal 

operations as soon as practical could be established for malfunctions that result in only small 

levels of excess HAP emissions, instead of requiring the regulated entity to establish and prove 

an affirmative defense. 

Response to comment 3.5: 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. Accounting for malfunctions would be difficult, if not impossible, given 

the myriad different types of malfunctions that can occur and given the difficulties associated 

with predicting or accounting for the frequency, degree, and duration of various malfunctions 

that might occur. EPA‘s rationale for its approach to malfunctions is not based on the criteria that 

must be met to justify a work practice standard under CAA section 112(h). Further, setting work 

practice standards under section 112 presents the same issues as setting numerical emission 

limits given the varied nature of malfunctions. 
3-4

Comment 3.6: One commenter (0142) contended that responding to malfunctions is many 

times a case-by-case situation depending on the specifics of the malfunction and equipment to be 

repaired, making the language regarding off-shift and overtime labor unnecessary and confusing. 

The use of overtime or off-shift labor is only one consideration in how to address a malfunction 

event. If EPA wants to point out that the use of overtime or off-shift labor must be used, then 

this language is best included in the preamble rather than the rule itself

Response to comment 3.6: Commenter does not explain its view that the language is 

confusing or explain how its suggested language clarifies this provision. Commenter also does 

not explain its view that the provision is not necessary. The requirement to use overtime labor or 

off-shift labor to make repairs when practicable clarifies what we expect sources to do to meet 

the condition to make repairs expeditiously.

Comment 3.7: One commenter (0142) argued that imposing a requirement to print and 

sign a record of actions in response to the excess emissions (40 CFR 63.11895(a)(7)) is outdated 

if one can document the response to actions in an electronic format, and thus requested the 

language be updated to allow for electronic documentation.

Response to comment 3.7: EPA accepts documents in electronic format, as long as the 

format is compatible with the requirements of the standards. The written reports required to 

demonstrate that the affirmative defense provisions have been met and requests for an extension 

of the deadline for these reports may be submitted electronically. Owners and operators who 

submit documentation for affirmative defense electronically should exercise due diligence to 

ensure receipt by the Administrator and the delegated permit authority.

Comment 3.8: One commenter (0142) requested that EPA not require the preparation and 

submission of a formal root cause analysis because this would have a chilling effect on internal 

communications regarding the root cause investigation and would detract from the goal of 

ensuring a candid inquiry into the event. They also argued that a regulation of this sort is 

unnecessary because the cause of even smaller malfunction events is routinely investigated 

within the industry.

Response to comment 3.8: Commenter does not explain his view that preparation of root 

cause analysis would chill internal communications, and EPA sees no reason that requiring such 

an analysis to be prepared would do so. Indeed, EPA has specified in consent decrees that root 
3-5

cause analysis be conducted and we have never had complaints from the defendants saying that 

this chills internal communications. 

Comment 3.9: One commenter (0141) contended that EPA lacks the legal authority to 

shift the burden to the source to prove by a preponderance of the evidence that it has met all of 

EPA‘s specified criteria and has taken specified actions (which bear no relation to the statutory 

factors for performance standards under section 112), in order to avoid ―civil penalties‖, and to 

do so within 30 days of the event, without even being charged. Another commenter (0142) 

stated that some aspects of the affirmative defense would make it unavailable as a practical 

matter for many, if not most, malfunctions since they do not directly relate to the question of 

whether an exceedance of the emission limitations due to a malfunction should be excused. For 

example, the requirement in proposed §63.11895(a)(8) that the source must show that ―at all 

times, the facility was operated in a manner consistent with good practices for minimizing 

emissions.‖ Or, the requirements in §63.11895(b) that the source must notify the Administrator 

as soon as possible but no later than 2 working days after the initial occurrence of the 

malfunction, and must then submit a written report to the Administrator within 45 days of the 

malfunction that demonstrates, ―with all necessary supporting documentation‖ that the source 

has met each and every factor specified in the proposed affirmative defense. It is unacceptable 

for EPA to presume that a person has violated the law unless the person has submitted his entire 

defense in writing before he is even given notice of a potential enforcement action."

Response to comment 3.9: EPA disagrees with comments that criticize the affirmative 

defense for shifting the burden of proof. The affirmative defense does not require a facility to 

prove its innocence rather than requiring an enforcement authority to prove a violation of the 

CAA or change the burden of proof with respect to establishing a violation. Further, EPA does 

not presume a violation unless the reporting requirements are met as commenter suggests. An 

affirmative defense to civil penalties for exceedances of emission limits that are caused by 

malfunctions is available to a source owner or operator, but the decision to use the affirmative 

defense and meet the reporting and recordkeeping requirements rests with the source owner or 

operator, who must weigh the cost of meeting the requirements against their perceived need to 

prepare for assertion of an affirmative defense if a violation is established. The affirmative 

defense applies to penalties; thus it is only used where a violation has been established. The 

burden of proof remains with the plaintiff in an enforcement action. See, e.g., 40 C.F.R. 22.24. If 
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a violation has been established and a source owner or operator wishes to assert the affirmative 

defense with respect to penalties, the source owner or operator bears the burden of establishing 

that the elements of the affirmative defense have been met. This burden-shifting is appropriate 

because the source owner or operator is in a better position to determine the facts required to 

establish the defense. See, e.g., Arizona Pub. Serv. Co. v. EPA, 562 F.3d 1116, 1120, 1129-30 

(10th Cir. 2009) (rejecting industry challenge to EPA‘s use of an affirmative defense to address 

excess emissions during malfunction events). Our judgment is that the affirmative defense 

criteria capture the appropriate considerations in determining whether penalties are appropriate 

when a violation occurs as the result of a malfunction. Many of the conditions were modeled 

after the conditions of the affirmative defense in EPA‘s SIP SSM policy, which several states 

have adopted into their SIPs. (See, e.g., State Implementation Plans: Policy Regarding Excessive 

Emissions During Malfunctions, Startup, and Shutdown (Sept. 20, 1999); Policy on Excess 

Emissions During Startup, Shutdown, Maintenance, and Malfunctions (Feb. 15, 1983)). We do 

not have any indication that parties to enforcement proceedings have had any significant 

difficulties applying the terms of these SIP affirmative defenses. EPA notes that the final rule 

does not include the 2-day reporting requirement that commenter criticizes. 

Comment 3.10: One commenter (0141) requests that the language of the affirmative 

defense be updated to state clearly that a source that qualifies for the affirmative defense shall 

not be deemed to have violated the applicable standards during that time.

Response to comment 3.10: EPA's approach has been very clear that sources may raise an 

affirmative defense to penalties only, not to liability. Successful assertion of an affirmative 

defense would not negate a violation and injunctive relief would be available. 

Comment 3.11: Two commenters (0142, 0153) disagreed with the requirement in 

subsection (9)(b) to notify the Administrator within two days of an emissions event and to 

submit a written report within 45 days of an event in order to seek to rely on an affirmative 

defense. They contended that these requirements are unnecessary due to emissions release 

reporting required by state agencies, CERCLA/EPCRA, the EPA Risk Management Program, 

and OSHA‘s Process Safety Management Standard. They proposed that the information could be 

included as part of the semi-annual report required by the Title V Operating Permit reporting 

program. 
3-7

Response to comment 3.11: We agree with the commenter and have revised the reporting 

requirement for asserting an affirmative in §63.11895(b) An affirmative defense to civil 

penalties for exceedances of emission limits that are caused by malfunctions is available to a

source owner or operator if he can demonstrate that certain criteria and requirements are 

satisfied. The criteria ensure that the affirmative defense is available only where the event that 

causes an exceedance of the emission limit meets the definition of malfunction in 40 C.F.R. 63.2 

(sudden, infrequent, not reasonably preventable and not caused by poor maintenance and or 

careless operation) and where the source owner or operator took all appropriate actions to 

minimize emissions. 

If a source is in compliance and does not encounter malfunctions that cause a violation of 

the standard, we do not expect this activity to be routinely performed by a source owner or 

operator. The decision to meet the reporting and recordkeeping requirements rests with the 

source owner or operator, who must weigh the cost of meeting the requirements against his 

perceived need to prepare an affirmative defense. 

However, the rule‘s affirmative defense provisions in §63.11895(b) have been revised to 

remove the 2-day notification requirement. We notification of malfunctions in the report 

specified in §63.10(e)(3) that requires the owner or operator to ―submit an excess emissions 

report‖ to the Administrator semiannually. In addition, we have revised §63.11895(b) in the final 

rule to allow an owner or operator of the affected source seeking to assert an affirmative defense 

after experiencing an exceedance of its emission limit(s) or a violation of an emission standard 

during a malfunction to submit a written report to the Administrator in the semiannual 

compliance report.

Comment 3.12: One commenter (0142) requested that EPA make the reporting 

obligations consistent with those outlined in §63.11895 of the rule if the owner/operator opts to 

establish an affirmative defense a malfunction. They argued that the 10 day reporting obligation 

is not consistent with other portions of the proposed rule and is also inconsistent with other part 

63 NESHAP. They proposed that the type of information required by §63.11985(c)(8) could also 

be reported as part of the semi-annual report required in §63.11985 for emissions events that 

result in an emission quantity that is less than the Reportable Quantity (RQ) established in 40 

CFR part 302 or 40 CFR part 355. They argued that inclusion in the semi-annual report would 

streamline the reporting obligations for both regulated entities and regulatory agencies.
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Response to comment 3.12: EPA is retaining the 10-day reporting requirement specified 

in §63.11915(c)(3). When a malfunction occurs, sources must report them according to the 

applicable reporting requirements of the subpart. An affirmative defense to civil penalties for 

exceedances of emission limits that are caused by malfunctions is available to a source if it can 

demonstrate that certain criteria and requirements are satisfied. The criteria ensure that the 

affirmative defense is available only where the event that causes an exceedance of the emission 

limit meets the definition of malfunction in 40 C.F.R. 63.2 (sudden, infrequent, not reasonably 

preventable and not caused by poor maintenance and or careless operation) and where the source 

took all appropriate actions to minimize emissions. In addition, the source must meet certain 

recordkeeping and reporting requirements. If a source is in compliance and does not encounter 

malfunctions that cause a violation of the standard, EPA does not expect this activity to be 

routinely performed by a source. The decision to meet the reporting and recordkeeping 

requirements rests with the source, who must weigh the cost of meeting the requirements against 

their perceived need to prepare an affirmative defense. These requirements are also similar in 

nature to the SSM reporting and recordkeeping requirements to which sources were previously 

subject, and they require the type of records and reports that sources would already typically

keep to demonstrate compliance with the general duty to minimize emissions. 

However, EPA agrees with the commenter that the 2-day notification is not needed 

because the 10-day report is required. §63.11915(c)(3) requires that for ―any instance that the 

release indicator indicates that a pressure relief device is open, you must . . . submit to the 

Administrator the report specified in §63.11985(c)(8) , This report is required even if you elect 

to follow the procedures specified in §63.11895(b) to establish an affirmative defense.‖ 

Therefore, EPA is revising the affirmative defense provisions in §63.11895(b) to 

remove the 2-day notification requirement. 

4.0 APPLICABILITY

Comment 4.1: Two commenters (0153, 0146) requested clarification on the applicability 

of the rule to wastewater. One commenter (0146) specifically requested that EPA verify that 

downstream wastewater treatment systems that are not being used to meet emission limits set 

forth in the PVC MACT: (1) are not part of the PVCPU; and (2) are not subject to PVC MACT 

regulations. The Commenter (0146) requested that EPA allow for exemptions from the 
4-9

wastewater requirements for safety related activities and continue to exempt segregated 

stormwater.

Response to comment 4.1: In the final rule, we have removed wastewater and process 

wastewater treatment systems from the definition of PVCPU but added them to the definition of 

affected source. Affected sources are required to meet the final vinyl chloride and total non-vinyl 

chloride organic HAP limits for process wastewater before the process wastewater streams are 

exposed to the atmosphere and before they are discharged from the affected source. In the final 

rule, we do not specify what type of treatment must be used to meet the process wastewater 

limits. If an affected source chooses to meet the limits by using a wastewater steam stripper, then 

the limits must be met at the outlet of the treatment system (i.e., the steam stripper). If the

streams treated by the steam stripper have met the required limits for process wastewater before 

being exposed to the atmosphere and before being discharged from the affected source, then 

there are no further requirements for treatment. Further, if those treated streams that have already 

met the process wastewater limits are subsequently sent to a secondary treatment process, such 

as a ―downstream‖ biological treatment system, then there are no additional requirements for 

those ―downstream‖ wastewater treatment systems. In the final rule, we have revised the 

definition of wastewater to exclude certain safety-related streams and segregated stormwater. See 

sections V.F.4 and V.I of the preamble for the final rule for additional detail on the final 

requirements for process and maintenance wastewater and for additional rationale for the 

changes to the final rule.

Comment 4.2: One commenter (0139) proposed that EPA simplify subpart HHHHHHH 

by using the NESHAP for Vinyl Chloride as a framework and adding requirements and 

definitions for the HAPs limitations. The commenter (0139) contends that this would make the 

rule easier to understand, because the regulated community is already familiar with this rule.

Response to comment 4.2: We disagree with the commenter‘s suggestion. The 

framework for developing the MACT standards is section 112(d) of the Clean Air Act, as 

amended in 1990, not the part 61 NESHAP, which was developed prior to the enactment of the 

current 112(d) requirements. We have, however, harmonized the provisions of subpart 

HHHHHHH with existing provisions of the part 61 NESHAP wherever possible.
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Comment 4.3: Two commenters (0137, 0142) supported EPA‘s proposal that once 

facilities are in compliance with the final PVCPU MACT, the requirements of the part 61 

NESHAP would no longer apply. One commenter (0137) also contended that all part 61 

referenced sampling methodologies should be moved to part 63, and any other proposed part 61 

cross-references should be directly incorporated into the final rule.

Response to comment 4.3: In the final rule, we have clarified that once PVC facilities are 

in compliance with subpart DDDDDD or subpart HHHHHHH then they no longer have to 

comply with 40 CFR part 61 subpart F. We disagree with the commenter regarding moving 

sampling methods in part 61 to part 63. The sampling methods (EPA Methods 106 and 107) are

in part 61 Appendix B of part 61 and are expressly referenced in subparts HHHHHHH and 

DDDDDD; therefore, there is no reason to move the Methods.

Comment 4.4: One commenter (0150) contended that EPA claims that a ―new‖ source is 

any source for which construction or reconstruction is commenced ―on or after May 20, 2011‖ 

76 Fed. Reg. at 29532 conflicts with the Clean Air Act. The commenter (0150) stated that the 

Clean Air Act, makes clear that a new source is one that constructed or modified after the date on 

which EPA ―first proposed‖ standards for the PVC category. The commenter (0150) stated that 

the date is not May 20, 2011 but December 8, 2000. Accordingly, the commenter (0150) 

concluded that any source constructed after December 8, 2000 is a new source and any source 

reconstructed or modified after December 8, 2000 is a new source.

Response to comment 4.4: Section 112(a)(4) of the CAA states that a new source is a 

stationary source if ―the construction or reconstruction of which is commenced after the 

Administrator first proposes regulations under this section establishing an emissions standard 

applicable to such source.‖ ―First proposes‖ could refer to the date the EPA first proposes 

standards for the source category as a whole, or could refer to the date the Agency first proposes 

standards under a particular rulemaking record, or first proposes the particular standards at issue. 

We believe that the May 20, 2011, proposal date is the proper date under CAA section 112(a)(4) 

because the intent of the new source provision is to provide sources with sufficient notice so that 

new source control requirements can be considered in the initial design.

Sources coming into existence between the December 8, 2000, proposal date and the May 

20, 2011, proposal date would have no reasonable means of ascertaining the standards‘ for this 

final rule and so lacked notice of what controls and strategies to adopt. Because this is 
5-11

antithetical to the policy underlying new source standards, the EPA is maintaining May 20, 2011, 

as the date which determines if a source is existing or new. We believe it would be unreasonable 

to require these sources to comply with the new source limits in this final rule when such limits 

were not even available for consideration at the time the units were constructed. We also note 

that the standards proposed in 2000 and promulgated in 2002 were subject to legal challenge, and 

subsequently vacated; thus, they by court order, do not exist. Moreover, that rulemaking did not 

impose new or different standards; it merely reaffirmed the existing part 61 NESHAP standards 

that already applied. Therefore, the relevant proposal date for determining new source status for 

the standards in this rulemaking is May 20, 2011. 

5.0 AREA SOURCES

Comment 5.1: One commenter (0153) disagreed that all of the technology necessary to 

meet the MACT limits is generally available.

Response to comment 5.1: We revised our approach to determining GACT in developing 

this final rule, as discussed in preamble section III.E. In determining what constitutes generally 

available control technology (GACT) for this final rule, we considered the control technologies 

and management practices that are generally available to PVC area sources by examining 

relevant data and information, including information collected from the two existing PVC area 

sources. We also considered the control options applicable to PVC major sources to determine if 

the control technologies and management practices used at PVC major sources are transferable 

and generally available to PVC area sources. See preamble Section V.H. for additional response 

to Area Sources comments.

Comment 5.2: One commenter (0153) suggested that instead of combining PVC MACT 

and GACT, EPA could easily promulgate an updated GACT standard using cross-references to 

applicable subsections of the PVC MACT and prepare revised GACT requirements (subpart 

DDDDDD) that minimize the burden on small plants.

Response to comment 5.2: In the final PVC rules, we have set separate standards for area 

sources and major sources. For area sources, which are regulated under subpart DDDDDD, we 

have updated and added new GACT requirements including the use of cross-referencing to 

sections of the PVC MACT standards as applicable. 
6-12

Comment 5.3: One commenter (0149) contended that EPA‘s proposed use of a 

refrigerated condenser by CertainTeed to achieve the proposed VC standard for process vents is 

not technically feasible, because EPA did not account for the process design of CertainTeed‘s 

bulk manufacturing process.

Response to comment 5.3: As a result of our GACT analysis for the final rule, 

CertainTeed is the only area source in the PVC-only subcategory for process vents and thereby 

its level of control represents GACT for PVC-only process vents; therefore, their current control 

technology should be adequate to meet the final rule emission limits. We have also determined 

that major source testing and monitoring requirements are appropriate and necessary to ensure 

that PVC area sources are in compliance with the process vent standards. See section V.H of the 

preamble to the final PVC rules for a discussion of the revisions to the area source GACT 

analysis.

6.0 BEYOND-THE-FLOOR ANALYSIS

Comment 6.1: One commenter (PH-BR-0011) was critical of the subjective standard that 

EPA applied to determine which controls were appropriate and beyond-the-floor.

One commenter (0137) agreed with EPA‘s conclusion that there are no technically or 

economically feasible ―beyond-the-floor‖ options. Another commenter (0150) disputed EPA

speculation that the technologies sources are already using are generally the most effective. The 

commenter (0150) noted that EPA should recognize distinct models of a given control 

technology (e.g., a fabric filter) as unique controls. This commenter (0150) argued that EPA had 

not properly demonstrated that existing controls for process vents reflect the maximum 

achievable degree and therefore not satisfied statutory requirements.

Response to comment 6.1: We disagree with the commenters‘ assertions that the 

standards used were improper for being subjective and that we did not properly demonstrate that 

existing controls reflect the maximum level of control achievable. The PVC MACT requirements 

were determined following the requirements of the CAA. We first determined the MACT floor 

level of control. We then calculated the cost and emissions reductions to identify options that 

were more stringent than the MACT floor level of control. We made our final determination of 

MACT based on our evaluation of cost and emissions reduction for options more stringent than 
6-13

the MACT floor. For some emission points such as equipment leaks, we determined it was 

appropriate to go beyond-the-floor level of control. For other emission points such as for stripped 

resins and process vents, we determined it was not appropriate. Commenters did not provide any 

data to support their assertions that we had not properly conducted the beyond-the-floor analyses

or that EPA did not properly identify or analyze maximum achievable controls. A detailed 

discussion of the beyond-the-floor analysis is contained in the memorandum, ―Revised Beyondthe-Floor Analysis for the Polyvinyl Chloride and Copolymers (PVC) Production Source 

Category,‖ which may be found in the docket. We also disagree with the commenter regarding 

setting MACT floors based on distinctive technologies. In this rule, EPA is using lowest 

emissions as the measure of best performance (except for those sources where a work practice is 

more appropriate, e.g., equipment leaks), irrespective of the types of controls that are being used. 

This approach is consistent with other MACT standards developed by EPA.

Comment 6.2: One commenter (0153) contended that using thermal oxidizers along with 

VCM absorbers is not practiced in the PVC industry, and to do so would be a beyond-the-floor 

consideration. The commenter (0153) stated that the annualized cost to do so is $190,000/T TOH 

at PolyOne‘s Henry, Illinois facility and $370,000/T TOH at PolyOne and OxyVinyls 

Pedricktown, New Jersey facility.

Response to comment 6.2: We disagree with the commenter regarding setting MACT 

floors. In this rule, EPA is using lowest emissions as the measure of best performance (except for 

where a work practice was required, e.g., equipment leaks), irrespective of the types of controls 

that are being used. As a result, all process vent streams from PVCPUs are included in the 

MACT floor analysis. This approach is consistent with other MACT standards developed by 

EPA. In the final rule, we are not requiring any particular control technologies be used by 

facilities to meet the emission limits. Facilities are free to choose whichever control technology 

or measure is appropriate for their particular operations, as long as the emission limits are met 

and the other requirements in the final rule, such as those for compliance assurance, are satisfied. 

In the final rule, the process vent emission limits and our cost and impacts analyses have been 

revised. Please see the preamble for the final rule for additional explanation and rationale for 

those revisions and the memorandum Revised Maximum Achievable Control Technology 

(MACT) Floor Analysis for the Polyvinyl Chloride and Copolymers (PVC) Production Source 

Category.
6-14

Comment 6.3: One commenter (0150) argued that because EPA claimed that activated 

carbon injection was the most effective method for reducing dioxin emissions, all sources should 

be required to reduce their dioxin emissions with activated carbon. Other commenters (0134, 

0146, 0153) contended that activated carbon injection should be considered a beyond-the-floor 

requirement. Commenters (0134, 0153) stated they were unaware of any source with 

dioxin/furan levels similar to PVC or (0153) similar equipment configurations or any similar 

source like a natural gas fired boiler that uses ACI with fabric filter control. A commenter (0153) 

stated that suppliers indicate that high moisture present in vent gas streams after absorbers may 

interfere with removal effectiveness of the carbon and filter combination in an acidic 

environment. The commenter (0153) stated several suppliers of the equipment indicated that 

development work would be needed to test such an application. Another commenter (0134) 

contended that high moisture and HCl levels are likely to be technological challenges to the use 

of ACI on TO stacks. 

Response to comment 6.3: In the preamble to the proposed rule, we did not claim that 

activated carbon injection is the most effective method for reducing dioxin emissions. We do 

recognize, however, that ACI is used in other industries as an effective means to reduce and 

control dioxin emissions from combustion sources. In the proposed rule, and in the final rules, 

the MACT floor emission levels for dioxins and furans are based on the emissions information 

collected, not on the technology being used. We note that none of the PVC facilities use ACI. 

We did not propose that PVC facilities must use ACI to meet the dioxin/furan emission limits. In 

our estimate of costs and impacts of the proposed rule (documented in the memorandum, Costs 

and Emission Reductions for Major Sources in the Polyvinyl Chloride and Copolymers (PVC) 

Production Source Category), we calculated the cost of compliance with the MACT emission 

limits assuming that ACI would be an applicable technology and could be used to reduce dioxin 

and furan emissions. For the final rule, we have revised the MACT floor emission limits for 

dioxins and furans. See section V.E of the preamble to final PVC standards. We have also 

revised our assessment of applicable technologies for reducing dioxin and furan emissions from 

PVC process vents based on the comments received. For the final standards, the control 

technologies that would be needed to achieve the MACT floor levels for process vents (i.e., 

enhanced recovery) are generally the most effective controls available for reducing VC, HCl, 

total organic HAP, and CDD/CDF. As documented in the memorandum, Revised Costs and 
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Emission Reductions for Major Sources in the Polyvinyl Chloride and Copolymers (PVC) 

Production Source Category, for facilities that needed additional emission reductions to meet the 

MACT floor limits for all pollutants in both subcategories of process vents, we estimated the cost 

for those facilities to install an additional refrigerated condenser (i.e., enhanced recovery). As a 

beyond-the-floor option for process vents, we estimated the cost for facilities to meet the final 

new source limits through the installation of a larger or replacement recovery system, but still 

using the same technology. For the reasons stated earlier and because ACI is not a demonstrated 

technology for controlling CDD/CDF in this industry, we did not assume that ACI would be used 

to meet the new source process vent limits. Additionally, based on our beyond-the-floor analysis,

we concluded it is not cost effective to go beyond-the-floor for CDD/CDF for either process vent 

subcategory.

7.0 EQUIPMENT LEAKS

7.1 Compliance and Monitoring

Comment 7.1.1: Two commenters (0146, 0160) requested that EPA provide the option of 

complying with the subpart UU MACT or 40 CFR part 61, subpart V in the equipment leaks 

provisions of the proposal. The commenters (0146, 0160) argued that the top five sources are a 

mixture of both rules, and thus EPA should provide the option to comply with either monitoring 

program for all affected sources.

Response to comment 7.1.1: After receiving data corrections concerning control 

measures applied to equipment leaks at one facility, we revised the MACT floor analysis for 

equipment leaks at existing PVC sources. This revised analysis showed that two out of the best 

performing five sources comply with 40 CFR part 63, subpart UU level 2 requirements, and the 

remaining three complied with 40 CFR part 61 subpart V. The subpart UU level 2 requirements 

are more stringent than the subpart V requirements. Therefore, for the final rule, the MACT floor 

level of control for equipment leaks at existing PVC sources, taken as the median of the bestcontrolled five sources, is compliance with 40 CFR part 61 subpart V. We conducted a beyondthe-floor analysis for equipment leaks at existing major sources and based on these results, we 

determined that going beyond the floor for equipment leaks at existing PVC major sources is 

cost-effective based on compliance with 40 CFR part 63, subpart UU level 2 requirements. The 
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MACT floor level of control for new PVC major sources also is compliance with 40 CFR part 

63, subpart UU level 2, which we identified as the most effective control of emissions from 

equipment leaks at PVC facilities. We did not identify any additional means of control for 

equipment leaks at new sources that are cost-effective. We are therefore setting the final MACT 

standards for new sources at the floor level of control and not going beyond the floor. This 

analysis is discussed in the memorandum Revised Beyond-the-Floor Analysis for the Polyvinyl 

Chloride and Copolymers (PVC) Production Source Category.

Comment 7.1.2: One commenter (0153) argued that the monitoring frequency for leak 

detection and repair programs required by the rule under subpart UU should be reduced. The 

commenter (0153) stated that area monitoring requirements were put in place by industry before 

promulgation.

Response to comment 7.1.2: We disagree with the commenter. Under the part 61 

NESHAP, PVC facilities are required to install area monitors as well as comply with the leak 

detection and repair requirements of 40 CFR part 61, subpart V. As discussed in the previous 

response, we have determined that the MACT level of control is equivalent to compliance with 

40 CFR part 63, subpart UU level 2, which has specific monitoring requirements. Regardless of 

whether area monitors are in place, the compliance requirements from subpart UU are required 

to meet the PVC MACT standards. 

Comment 7.1.3: One commenter (0121) pointed out that EPA stated in 76 FR 29533 that 

―we are also proposing that, in addition to operating with no detectable emissions, there be no 

discharge to the atmosphere from any PRD on any equipment in HAP service within the 

PVCPU.‖ The commenter (0121) proposed that upon a discharge to the atmosphere from the 

PRD that the monitoring requirements specified in 40 CFR part 63, subpart UU for pressure 

releases from PRD be followed. However, the commenter (0121) pointed out, EPA also stated 

―we are proposing that existing and new affected sources comply with the leak detection and 

repair (LDAR) program requirements of the National Emission Standards for Equipment LeaksControl Level 2 Standards, subpart UU of 40 CFR part 63, except for agitators, and rotating or 

reciprocating pumps and compressors.‖ The commenter (0121) added that for gas and light 

liquid valves, subpart UU specifies a leak definition of 500 parts per million VOC, and a 

monitoring frequency that is dependent upon the number of leaking valves (76 FR 29533). The 
7-17

commenter (0121) stated that although a leak is defined by subpart UU at 500 parts per million, 

"no detectable emissions" implies that any detectable emission greater than zero that occurs from 

a PRD would be a violation, so these conflicting statements need to be reconciled.

Response to comment 7.1.3: In preamble Sections IV.E.2. and IV.F.2., we clarify that we 

are requiring that existing and new affected sources comply with the leak detection and repair 

(LDAR) program requirements of the National Emission Standards for Equipment Leaks -

Control Level 2 Standards, subpart UU of 40 CFR part 63. We are also requiring that, in 

addition to operating with no detectable emissions, there be no direct discharge to the 

atmosphere from any pressure relief device (PRD) on any equipment in HAP service within the 

PVCPU. If a discharge from a PRD is routed through a closed vent system to a control device, 

the discharge must meet the emission limits for process vents. We are requiring that, after a 

direct discharge to the atmosphere from the PRD, sources must comply with the monitoring 

requirements specified in 40 CFR part 63, subpart UU for pressure releases from PRD.

7.2 Emission Limits, Operating Limits, and Work Practice Standards

Comment 7.2.1: One commenter (0157) contended that EPA should revise the 10 ppm 

HAP limit for double mechanical seals used in rotating compressors in section §63.11915(b)(3) 

of the proposed rule to be consistent with the total HAP limit in Table 1 to 12 ppm. The 

commenter (0157) asked how the agency derived the 10 ppm HAP limit, wondering if the limit 

were adopted from the VC NESHAP.

Response to comment 7.2.1: The commenter is correct that the 10 ppm limit in the 

proposed rule was based on the part 61 NESHAP. We have revised the process vent limits for the 

final rules. See section III for a summary of the changes to the limits. In the proposed rule, we 

required reciprocating pumps, reciprocating and rotating compressors and agitators to be 

equipped with double seals or the equivalent. In the final rule, we are also allowing affected 

sources to comply with the requirements for reciprocating pumps, reciprocating and rotating 

compressors and agitators by complying with the requirements for 40 CFR part 63, subpart UU.

Comment 7.2.2: One commenter (0120) agreed with EPA‘s proposal to require that new 

and existing facilities comply with subpart UU, which is also in line with STAPPA/ALAPCO 

recommendations.
8-18

Response to comment 7.2.2: We acknowledge the support of the commenters.

8.0 HEAT EXCHANGE SYSTEMS

Comment 8.1: One commenter (0146) requested clarification on the proposed calculation 

methodology for estimating potential VOC emissions from leaking heat exchange systems [40 

CFR 63.11920(h)(4)(ii)].

Response to comment 8.1: We have added an equation in the final rule for estimating 

emissions from leaking heat exchange systems.

Comment 8.2: Five commenters (0141, 0142, 0143, 0146, 0160) requested that EPA alter 

the final rule to account for VOC emissions from non-PVC sources. The commenters (0141, 

0142, 0143, 0146, 0160) contended that recycled water in cooling towers can originate from both 

PVC MACT and non-PVC MACT affected sources and there is a potential for low levels of 

VOC. In certain locations, sources of clean make-up water are not available. Additionally, the 

commenters (0141, 0142, 0143, 0146, 0160) stated that treatment of cooling tower water using 

biocides and other additives can also cause elevated VOC readings which could be detected by 

the proposed Modified El Paso Method. The commenters (0141, 0142, 0143, 0146, 0160) added 

that the extremely low leak action levels proposed by EPA present a problem during these 

normal operations and put the need for essential cooling water treatment in conflict with rule 

compliance. The commenters (0141, 0142, 0143, 0146, 0160) argued that EPA should consider 

alternatives to testing the water return line to the cooling tower. Several commenters (0160, 

0153, 0146) suggested that an affected source should be allowed to determine a VOC baseline 

for recycled water, and then use this value in the calculation of a leak action threshold. One 

commenter (0142) suggested that owners/operators should be allowed to sample individual heat 

exchangers at the inlet and outlet of the closed loop heat exchange system to determine the 

presence of a leak. The commenter (0142) stated that this would be similar to the proposed 

continuous compliance standards for once through cooling water systems at 40 CFR 

63.11920(a)(2)(i) and (ii). One commenter (0153) argued that certain areas of the country with 

water shortages mandate water recycling. 

Response to comment 8.2: In the final rule, we have made some clarifying revisions to 

the heat exchange system rule language. We do not have data available to us, either from 
8-19

commenters or other sources, to substantiate or evaluate commenters' assertions regarding

―baseline‖ levels of VOCs present in cooling water as a result of additives, treatment chemicals, 

or recycled water streams. In the final rule, we have revised the leak action levels and monitoring 

frequencies for heat exchange systems. We have also provided an option in the final rule for 

facilities to monitor either total strippable VOC or vinyl chloride in the cooling water. See 

section V.F.5 of the preamble for the final rule for additional explanation and rationale.

Comment 8.3: Three commenters (0143, 0146, 0142) requested that the final rule include 

additional exemptions for heat exchangers to make the proposed rule consistent with other 

MACT standards. The commenters (0143, 0146, 0142) specifically cited, the Miscellaneous 

Organic Chemical Manufacturing (MON) subpart FFFF at 40 CFR 63.2490 and the Hazardous 

Organic NESHAP (HON) at 40 CFR 63.104(a)(1) through (6) [subpart F] which exempt heat 

exchange systems from monitoring requirements if one or more of the conditions are met: 1) 

intervening cooling fluid containing less than 5 percent by weight of total HAP, 2) once through 

heat exchange system is subject to a National Pollution Discharge Elimination System (NPDES) 

permit, 3) a recirculating heat exchange system is used to cool process fluids that contain less 

than 5% by weight of total HAP, or 4) once through heat exchange system is used to cool 

process fluids that contain less than 5% by weight of total HAP. Petroleum Refinery standards 

(subpart CC) at 40 CFR parts 63.654(b)(1)(ii) and 63.654(b)(2) have similar exemptions.

Response to comment 8.3: We have clarified in the final rule that heat exchange systems 

that are not in HAP service or that have a maximum cooling water flow rate of 10 or fewer 

gallons per minute are not required to monitor for leaks. In the final rule, in HAP service means 

that a process component either contains or contacts a liquid that is at least 5 percent HAP by 

weight or a gas that is at least 5 percent by volume HAP, as determined according to the 

provisions of 40 CFR 63.180(d). These requirements are consistent with other EPA MACT 

standards for heat exchange systems. We disagree with the commenter that once through heat 

exchange systems at PVC facilities should be exempted if they are subject to an NPDES permit. 

NPDES permits specify discharge limits to water and are not related to the air emissions from the 

heat exchange system that result from leaking equipment that are in contact with the heat 

exchange system.
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9.0 OTHER EMISSION SOURCES

Comment 9.1: Two commenters (0144, 0153) requested clarification on which HAP 

containing equipment must minimize emissions by reducing the volume to the amount that 

occupies 2% or 25 gallons, whichever is larger; the commenters (0144, 0153) pointed out that 

the preamble to the proposed rule under ―5. Other Emission Sources‖ stated the requirement 

applies to vinyl chloride emissions, yet the regulatory language (§63.11955) indicates the 

requirement applies to other HAP containing equipment. One commenter (0144) specifically 

requested that EPA revise the rule language by replacing total HAP with vinyl chloride to match 

the preamble language, which they stipulated would simplify compliance as there is already a 

methodology in place for sampling and detecting vinyl chloride.

One of the commenters (0153) requested clarification on measuring methods for 

demonstrating that equipment opening TOH standard is met. Specifically, the commenter (0153) 

requested clarification that if Method 21 monitoring instruments are to be used to prove the 

standard is met, they will need to be calibrated with propane or methane rather than VCM. The 

commenter (0153) pointed out that the reactor opening standard can continue to be controlled by 

measuring vinyl chloride concentrations or using a volumetric measurement as is done under the 

existing vinyl chloride NESHAP.

One commenter (0139) requested that EPA clarify the standard for reactor opening loss 

(ROL), proposing that the agency use the specific language from the part 61 NESHAP 

regulation.

Response to comment 9.1: In the final rule, we have revised the requirement for 

equipment openings to specify that the quantity of vinyl chloride must be reduced to an amount 

that occupies 2% of the containment volume, or 25 gallons, whichever is greater. It is appropriate 

to continue to set the standards based on vinyl chloride because it will always be present at this 

emission point, and controlling it will also control all other HAP. This change was made as the 

proposed requirement was inconsistent with the similar requirement in part 61 subpart F. All 

process components and equipment are subject to the equipment opening requirements; the 

requirements are not limited to only a subset of process components or equipment. Method 21 

should not be used to demonstrate compliance with the equipment opening standard. See section 

V.F.6 of the preamble for the final rule for additional details and rationale.
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Comment 9.2: One commenter (0134) requested clarification of the rule language 

regarding emissions from the unhooking of unloading lines from railcars. The commenter (0134) 

pointed out that the existing rule recognizes that it is not feasible to reduce VCM concentrations 

in the unloading hoses to meet the current 10 ppmw, three-hour average exhaust gas provision 

and instead requires a work practice standard; however, the preamble does not make this 

exception clear. The commenter (0134) requested that EPA place new language in the ―other 

emission sources‖ section at proposed §63.11955 as follows, to reflect these standards:

(a)(4) Vinyl chloride emissions from loading and unloading lines in HAP service which are 

opened to the atmosphere after each loading or unloading operation are to be minimized as 

follows: (i) After each loading or unloading operation and before opening a loading or unloading 

line to the atmosphere, the quantity of vinyl chloride in all parts of each loading or unloading line 

that are to be opened to the atmosphere is to be reduced so that the parts combined contain no 

greater than 0.0038 m3(0.13 ft3) of vinyl chloride, at standard temperature and pressure.

(ii) Any vinyl chloride removed from a loading or unloading line in accordance with paragraph 

(a)(4)(i) of this section is to be vented to a closed vent system and control device meeting the 

requirements in §63.11925.

Response to comment 9.2: In the final rule, we have added a definition for 

―miscellaneous vents‖ which includes gaseous emissions from loading and unloading lines. 

Miscellaneous vents are process vents and must meet the requirements for process vents. See the 

preamble to the final rule for additional explanation and rationale. The requirements for 

controlling emissions from loading and unloading operations are based on the part 61 standards, 

which facilities should be in compliance with already.

Comment 9.3: Two commenters (0139, 0146) requested clarification of the rule language 

regarding resin stripping in the reactor. Specifically, they (0139, 0146) recommended language 

from the part 61 NESHAP to clarify that the standard for reactor opening loss (―ROL‖) includes 

the: ―sum of allowable reactor opening losses, and the emission limit for all downstream

equipment (e.g., the stripped resin limits).‖ They (0139, 0146) also stipulated that the vinyl 

chloride limit in the proposed section 63.11955(b) should include an exception for stripping in 

the polymerizer similar to the one in the part 61 NESHAP (§61.64(a)(2)(f)).

Response to comment 9.3: In the proposed and final rule, we have established separate 

standards for equipment openings and stripped resin. We recognize that part 61 allowed the 
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combination of allowable reactor opening losses and all downstream equipment for purposes of 

determining compliance with the reactor opening losses standard. The equipment opening 

standard in the final rule is based on the existing part 61 requirement that the quantity of vinyl 

chloride remaining in the equipment prior to opening must be reduced to 2% of the equipment 

containment volume or 25 gallons, whichever is greater. We have retained this requirement in 

the final rule, but the standard applies to all equipment and process components, not just to 

reactors. We do not agree with the commenter that there should be an exemption for 

polymerization reactors. Reactor openings have been regulated under part 61 and will continue to 

be regulated under part 63 subparts DDDDDD and HHHHHHH.

Comment 9.4: Two commenters (0139, 0146) supported the agency‘s decision to use part

61 NESHAP requirements for vinyl chloride as the pollutant of concern for the polymerizers, as 

vinyl chloride is the major HAP in the reactor and has the highest partial pressure of all the 

HAPs known or suspected to be in the polymerizer.

Response to comment 9.4: We thank the commenters for their comments.

10.0 PROCESS VENTS

10.1 Compliance and Monitoring

10.1.1 General Support of Process Vent Floors and Compliance

Comment 10.1.1.1: One commenter (153) stated they support regulation of HAP 

emissions from resin production by requiring all vents upstream of the resin strippers to be 

routed to control equipment. 

Response to comment 10.1.1.1: We thank the commenter for their comment.

Comment 10.1.1.2: Two commenters (0146, 0153) stated they support the use of the total 

organic HAP concept for this MACT rule, rather than individual HAP limits. This would allow 

individual raw materials and byproducts to change, (0153) depending on customer demand and 

product innovations, while overall emission levels will be capped.
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Response to comment 10.1.1.2: We thank the commenter for their support. The final rule 

requires affected sources to meet total organic HAP, vinyl chloride, dioxin and furan, and HCl 

limits for process vents.

Comment 10.1.1.3: One commenter (0153) generally supported the allowance in 

§63.11935(d) to supplement performance tests with engineering judgment and manufacturer‘s

information when setting operating limits for regulated strippers and process vent control 

equipment. The commenter (0153) also generally supported various options for operating 

parameter combination to use for absorbers and acid gas scrubbers. 

Response to comment 10.1.1.3: We thank the commenter for their support.

10.1.2 General Concerns with Process Vent Floors and Compliance

Comment 10.1.2.1: One commenter (PH-BR-0011) contended that a problem exists with 

the process vent floors because EPA set a limit for the threshold that would trigger a vinyl 

chloride reduction, and then noted that the threshold is above any of the capacity of the PVC 

manufacturers. The commenter (PH-BR-0011) concluded that PVC manufacturers have an 

exemption from reduction requirements. 

Response to comment 10.1.2.1: We are unable to determine what the commenter is 

referencing. We proposed a vinyl chloride limit, and other limits, that would apply to process 

vents without any threshold and not based on capacity. The final emission limits will apply to all

process vents at PVC facilities. If the commenter is referring to the calculation of the emissions 

limits incorporating variability, we disagree with the commenter. Consistent with EPA‘s 

approach on other MACT standards, we have incorporated variability when establishing MACT 

floors. See our discussion of variability in the preamble to proposed rule as well as the 

memorandum Revised Maximum Achievable Control Technology (MACT) Floor Analysis for 

the Polyvinyl Chloride and Copolymers (PVC) Production Source Category. 

Comment 10.1.2.2: One commenter (PH-BR-0011) quoted EPA stating that the control 

technology that would be needed to achieve the proposed MACT floor levels for process vents 

are generally the most effective controls available for reducing vinyl chloride, hydrogen chloride, 

total organic hazardous air pollutants, and dioxins/furans. The commenter (PH-BR-0011) 
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contended that EPA does not require these control technologies; and it does not ensure that such 

control technologies, even if they were required of the PVC manufacturers, would actually 

achieve the maximum emission reduction, which should be the goal of this proposed rule.

Response to comment 10.1.2.2: Generally, our policy in setting MACT standards is not to

prescribe a control technology that must be used. Whenever possible we set emission limits that 

must be met and the source owner or operator has flexibility on the controls that they use to meet 

the limits. This approach is consistent with the Clean Air Act and with the approaches used to set 

emission limits based on emissions data from the best performing sources. We disagree with the 

commenter that we do not require the most effective controls and do not ensure that the emission 

standards are met. The MACT floor and beyond-the-floor analyses are contained in memoranda, 

Revised Maximum Achievable Control Technology (MACT) Floor Analysis for the Polyvinyl 

Chloride and Copolymers (PVC) Production Source Category and Revised Beyond-the-Floor 

Analysis for the Polyvinyl Chloride and Copolymers (PVC) Production Source Category, and the 

final rules contain initial and continuous compliance requirements that ensure that source owners 

or operators are continuously complying with the rule requirements including all applicable 

emission limits.

10.1.3 Closed Vent Systems and Control Device Bypass

Comment 10.1.3.1: One commenter (0146) argued that the PVC industry cannot 

―immediately comply‖ with section 63.11930(a) through (g), because section 63.11930(h)(2) 

requires that a closed vent system in vacuum service cannot be returned to vacuum service if the 

vacuum is lost. The commenter (0146) requested that EPA remove this provision for closed vent 

systems in vacuum service. 

Response to comment 10.1.3.1: In 40 CFR part 63, subpart UU, equipment in vacuum 

service is exempt from all of the leak detection and repair requirements, including recordkeeping 

and reporting. However, we are requiring demonstration that equipment is in vacuum service, 

including installation of a pressure gauge and alarm system that will alert an operator 

immediately and automatically when the pressure is such that the equipment no longer meets the 

definition of in vacuum service. While we continue to agree that monitoring the equipment in 

vacuum service for leaks is not necessary, we find that it is appropriate to demonstrate 

continuously that your equipment is in vacuum service or comply with the leak detection and 
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repair provisions of 63.11930(a) through (g). With respect to the requirement to ―immediately 

comply,‖ 63.11930(h)(2) specifies that actions to return the closed vent system to vacuum 

service must be initiated, or the source must begin to comply with the leak detection and repair 

provisions that are promulgated for closed vent systems, which do not operate in vacuum service.

Comment 10.1.3.2: One commenter (0146) stated that if promulgated, the proposed PVC 

MACT would impose the strictest requirements ever for closed vent systems, [76 FR 29570-

29573 (to be codified at 40 CFR. §63.11930)] vastly expanding the regulation of closed vents 

beyond subpart SS by: (1) requiring flow indicators equipped with an electronic alarm system 

that requires immediate action and results in an automatic violation; (2) making no provision for 

maintenance activities; (3) expanding the inspection requirements, and (4) failing to provide the 

exemptions in section 63.983(a)(3) for equipment needed for safety purposes such as pressure 

relief devices, low leg drains, high point bleeds, analyzer vents, and open-ended valves or lines. 

The commenter (0146) contended that EPA has provided no rationale or explanation for this 

expansion, or why the current closed vent system requirements under subpart SS are insufficient.

The commenter (0146) added that the proposed rule does not provide an exemption for 

maintenance activities on minor ancillary equipment that may be on a closed vent system, such 

as opening a low leg drain or a high point bleed, it would be a violation to perform maintenance 

on the system as ―[a] broken seal...constitutes a violation from the emission limits...‖ [76 FR 

29571 (to be codified at 40 CFR. §63.11930(c)(2)(i)).] This is a contradiction to EPA‘s CAA 

general duty clause both within this part and part 68, Risk Management Program. Another 

commenter (0157) stated that in many cases bypass valves on process vent lines are used in order 

to provide a bleed valve to ensure a safe work environment when maintenance is being 

performed on equipment. 

Response to comment 10.1.3.2: In previous rules, equipment that is part of a closed vent 

system has been subject to annual monitoring to detect leaks. The final rule contains additional

requirements to ensure that emissions streams are properly routed to the closed vent system and 

delivered to the control device for reduction. The final rule requires you to install and maintain a 

CPMS for flow through a bypass for each closed vent system bypass line that could divert a vent 

stream to the atmosphere. The CPMS for flow must be capable of recording the volume of the 

gas that bypasses the control device and be equipped with an alarm system that will alert an 

operator immediately and automatically when flow is detected in the bypass. These provisions 
10-26

are to ensure that any flow directed through a bypass is detected and identified by the operator. 

Alternatively, you may secure the bypass line valve in the non-diverting position with a seal 

mechanism. For this option, you would be required to inspect the seal or closure mechanism at 

least once per month to confirm that the valve is in the non-diverting position, or, for a lock-andkey type lock, maintain records that the key has been checked out. If the alarm sounds or if it is 

determined during the monthly inspection that a bypass has occurred, you would be required to 

report a deviation and to include an estimate of the resulting emissions of regulated material that 

bypassed the control device. Our intent in this final rule is that control devices will not be 

bypassed; therefore, use of the bypass at any time to divert a regulated vent stream to the 

atmosphere would be a deviation from the emissions standards. Additionally, due to the 

precedent set forth in the recent court vacatur of the exemptions to emissions standards for 

startup, shutdown, and malfunction [Sierra Club v. EPA, 551 F.3d 1019 (D.C. Cir. 2008)], we 

are required to ensure that section 112 emissions limitations are continuous and apply at all 

times. Thus, we are not adopting exemptions for maintenance activities and equipment such as 

pressure relief devices, low leg drains, high point bleeds, analyzer vents, and open-ended valves 

or lines as part of this action. We recognize that equipment that is properly designed and 

maintained can sometimes fail and that such failure can sometimes cause an exceedance of the 

relevant emission standard. Thus, for such situations, we have incorporated an affirmative 

defense provision which provides for a defense to civil penalties for emissions exceedances of 

standards that are caused by malfunction. 

Comment 10.1.3.3: One commenter (0141) requested clarification on EPA‘s statement in 

§63.11915(c) that states ―any release to the atmosphere from a PRD...constitutes a violation of 

the rule,‖ and that ―any release‖ will trigger the reporting requirements. They requested that EPA 

clarify in the final rule that these provisions only apply to releases that exceed the detectable 

emission level of 500 ppm. One commenter (0142) contended that pressure relief devices are 

already regulated under the equipment leak provisions in §63.11915(a) which states that the 

section for pressure relief devices (§63.1030) of subpart UU applies. The commenter (0142) 

argued that EPA should not regulate the same equipment under multiple sections of the rule.

Response to comment 10.1.3.3: 63.11915(c) prohibits direct releases to the atmosphere 

from pressure relief devices in HAP service and any such a release is an immediate violation. 

However, this requirement is not applicable to leaks which may occur after a PRD has a release 
10-27

because the seal does not reseat properly. To ensure that the PRD is properly reseated, 40 CFR 

63, subpart UU requires LDAR monitoring within 5 days of such a release. The PRD must 

always be operated with no detectable emissions (e.g. 500 ppm above background). 

Comment 10.1.3.4: One commenter (0157) argued that the proposed regulation regarding 

the automatic notification of a pressure relief device activating provides no allowance for the 

verification that a relief valve discharge did occur. The commenter (0157) argued that the 

language infers that the deviation occurs and requires reporting even though the activation of the 

detection device may not indicate a discharge. The commenter (0157) recommended that the 

proposed rule should include that verification by process history, area monitoring indicators, or 

other means of actual discharge are incorporated.

Response to comment 10.1.3.4: We agree the rule requires a release indicator to be 

properly installed on each PRD in such a way that it will indicate when an emission release has 

occurred and to be equipped with an alert system that will notify an operator immediately and 

automatically when the pressure relief device is discharged directly to the atmosphere. We also 

agree a report is required within 10 days after any instance that a release indicator indicates that a 

pressure relief device is open. We disagree that such reporting requirement does not allow 

verification of a release or that it improperly implies that a deviation occurred. The requirements 

for automatic notification to the operator and a 10 day report to the agency are based on the PRD 

being open, as detected by the release indicator. These requirements apply independently of any 

effort by the operator to verify that a PRD discharge occurred. Further, under the rule a deviation 

includes when a PRD discharges directly to the atmosphere. If the PRD release indicator is 

functioning as required by the rule, the requirements for automatic notification and reporting will 

only apply when a PRD has discharged directly to the atmosphere. These requirements are 

designed to alert the operator and inform the agency so that appropriate action can be taken to

address the source of the PRD release. For these reasons, verification by process history, area 

monitors or other means of actual discharge is not necessary.

Comment 10.1.3.5: One commenter (0157) pointed out that the Vinyl Chloride NESHAP 

provided for an alternative to deviation from the rule for relief valve discharges by allowing 

relief valve discharges to be ducted to a flare meeting the conditions of §60.18(d) and (f). The 

commenter (0157) stated that recognizing this type of control for relief valve discharges fails to 
10-28

recognize that the flare would certainly control organic HAP to a level exceeding 98%. The 

commenter (0157) contended that looking at organic HAP fails to recognize the HAP emissions 

likely produced by the combustion of vinyl chloride in the form of hydrogen chloride (HCI). 

Thus, the commenter (0157) argued, EPA should include provisions for the treatment of HAP 

relief valve discharges to a flare and incorporated into the final rule similar to the language in 

§61.65(d)(2). 

Response to comment 10.1.3.5: We disagree with the recommendation to allow emissions 

from relief valves at PVC facilities to be ducted to a flare. Because of the chlorine that exists in 

the vent stream and potential formation of dioxin, we have prohibited the use of flares to meet 

the emission limits in the final rule. According to the data received in the PVC CAA section 114 

survey, there are no flares in operation within the PVC industry. Some facilities route their PRDs 

into a gasholder or a closed vent system that is sent to a control device. In doing so, the PRD 

releases are part of the process vent stream and are subject to the process vent emission limits in 

Table 1 or 2 of the regulation.

Comment 10.1.3.6: One commenter (0141) argued with EPA‘s reasoning for requiring 

the installation of electronic indicators on each PRD. The commenter contended that in addition 

to the operational and safety reasons for closely tracking PRDs, the Part 61 NESHAP requires 

that PVC plant owners or operators submit a report within 10 days of every PRD release that 

provides information on the date, time, and duration of the release, along with the source, nature, 

and cause of the release. The commenter pointed out that PVC plants are also required to 

estimate the approximate emissions during the discharge, report the method used for determining 

the HAP emitted, include a description of the actions taken to prevent the discharge, and describe 

measures adopted to prevent future discharges. The commenter argues that these reports have 

provided EPA with years of data to allow for a rigorous analysis of the emissions from PRD 

releases and yet, the proposed rule provides no basis for the conclusion that there are significant 

HAP releases from PRDs.

Response to comment 10.1.3.6: The responses to these comments are in Sections V.F.2 

and V.J of the preamble to the final PVC rules. We disagree with the commenter that reports of 

PRD discharges have been provided to us. We also requested this type of information in the 

Section 114 survey requests and received no indication that any such releases occurred over the 

time period requested.
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Comment 10.1.3.7: Two commenters (0143, 0146) argued that EPA should remove the 

provision subjecting PVCPUs to automatic violations of the rule due to a bypass occurrence. The 

commenters (0143, 0146) argued that the agency has never provided for automatic violations if 

flows are detected or if the manual valve is opened. The commenters (0143, 0146) added that 

under the proposed rule, for each closed vent system that contains a bypass, a PVCPU would 

automatically be in violation of the rule if any emissions are discharged to the atmosphere 

through the bypass. [76 FR 29570.] Commenters (0141, 0143, 0146) argued that this proposed 

provision, including vacuum service indicators, is overly broad and does not provide the only 

assurance that a flow directed to a bypass will be detected and addressed. The commenters 

(0141, 0143, 0146) added that under other Clean Air Act ("CAA") regulations, the agency has 

required installation of flow indicators that are capable of taking periodic readings to address 

bypass monitoring and require that visual inspections of the seal or closure mechanism are 

performed at least monthly. [See 40 CFR 63.114(d); see also 40 CFR 63.983(a)(3)]. One 

commenter (0146) contended that if a control device is bypassed, that does not automatically 

mean that a violation occurred, such as the case where the PVCPU did all it could to prevent the 

release, but the cause of the release was outside of the Unit‘s control (e.g., direct lightning hit; 

terrorist attack; catastrophic mechanical failure, etc). The commenter (0146) concluded by 

stating if no design, maintenance, or operational error is involved in a bypass, these limited 

circumstances should not be violations subject to penalties. One commenter (0157) requested the 

agency clarify that the requirement to maintain the bypass in the closed position is only required 

when the closed vent system is actually in HAP service (i.e., not applicable after the line has 

been cleared in accordance with §63.11955). 

One commenter (0146) argued that under the Part 61 NESHAP, PVCPUs currently are 

prohibited from bypassing a control device, unless specific federally enforceable exemptions 

apply (e.g., emergency manual vent valve discharges and emergency relief discharges). The 

commenter (0146) stated that as such, PVCPU have operating procedures and mechanisms in 

place to prevent bypasses. The commenter (0146) added that as seen in the HON and subpart SS, 

installation of flow indicators and visual inspections ensure that operators are aware and can 

address any issues involving flows to a bypass; automatic violations of the rule will not 

necessarily ensure that a flow directed to a bypass is detected. The commenter (0146) 
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recommended that EPA should remove the provision subjecting PVCPUs to automatic violations 

of the rule. 

Response to comment 10.1.3.7: As one commenter stated, bypass of a control device at 

PVC facilities is already prohibited under the Part 61 regulations, except for certain emergency 

discharges. The final rule specifies that bypass means to divert a process vent or closed vent 

system stream to the atmosphere such that it does not first pass through an emission control 

device. The rule provides that a vent stream within a closed vent system must not be discharged 

to the atmosphere through a bypass. Section 63.11930(c) further provides that any such release 

constitutes a violation. We agree with commenters that the installation of flow indicators and the 

inspection, leak monitoring and repair provisions of this rule ensure that operators are aware and 

can address any issues involving flows to a bypass, including initiating repairs. These steps 

should avoid or minimize the bypassing of control devices. However, for this final rule, we have 

identified no basis to exempt bypasses from otherwise applicable requirements. The continuous 

use of a control device is necessary to meet the process vent limits; therefore, bypasses diverting 

vent streams away from the control device necessary to meet the emission standards and directly 

discharging to the atmosphere are in violation of the rule. These requirements are consistent with 

the Clean Air Act‘s mandate that emission standards continuously apply. 

We believe that most bypasses from closed vent systems are caused by malfunctions or 

other occurrences (e.g., poor design, improper maintenance, or operational error) that do not 

justify an exemption from standards that, under the CAA, apply continuously. For closed vent 

systems in vacuum service, we have specified that a violation has occurred only if the vacuum 

system alarm sounds and the closed vent system is not also meeting the requirements for closed 

vent systems not in vacuum service specified in 40 CFR 63.11930 of the final rule. We have 

also specified that each closed vent system must be designed and operated both to collect any gas 

or vapor HAP from each continuous process vent, miscellaneous process vent and batch process 

vent, or process component, and to route the collected vapors to a control device, regardless of 

whether the closed vent system is ―in HAP service.‖ The rule requirements specify that each 

process stream, including gas or vapor HAP removed in accordance with §63.11955, must be 

routed to a control device; therefore, the bypass must remained closed. These requirements have 

been structured to ensure that the emission standards apply at all times. 

For this final rule, we are including an affirmative defense to civil penalties for violations 

that are caused by malfunctions, including bypasses from closed vent systems that are caused by 
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malfunctions. See 40 CFR 63.12005 (defining ―affirmative defense‖ to mean, in the context of 

an enforcement proceeding, a response or defense put forward by a defendant, regarding which 

the defendant has the burden of proof, and the merits of which are independently and objectively 

evaluated in a judicial or administrative proceeding). We also are requiring other regulatory 

provisions to specify the elements that are necessary to establish this affirmative defense; the 

source must prove by a preponderance of the evidence that it has met all of the elements set forth 

in 40 CFR 63.11895. (See 40 CFR 22.24.) The criteria ensure that the affirmative defense is 

available only where the event that causes an exceedance of the emission limit meets the narrow 

definition of malfunction in 40 CFR 63.2 (sudden, infrequent, not reasonably preventable and not 

caused by poor maintenance and or careless operation). Therefore, instances where a bypass 

from a closed vent system is beyond the unit‘s control would be addressed by the affirmative 

defense. If a bypass occurs, it will be considered a violation, but the source is provided the 

opportunity to present an affirmative defense to civil penalties. 

Comment 10.1.3.8: One commenter (0153) stated that closed vent systems 

§63.11930(e)(1) indicate that leaks can be detected by Method 21 monitoring or by visual 

inspection. The commenter (0153) argued that sometimes, audio and olfactory methods are also 

effective and the option to use these devices should be added to the rule. 

Response to comment 10.1.3.8: The final rule requires sources to comply with the 

equipment leak standards in 40 CFR part 63 subpart UU level 2. The subpart UU level 2 

standards have requirements for instrument and sensory monitoring of leaks. Sensory monitoring 

includes visual, audible, olfactory, or any other sensory detection method used to determine a 

potential leak to the atmosphere.

10.1.4 CEMS/CPMS

Comment 10.1.4.1: A commenter (0142) argued that EPA‘s requirement for new sources 

to use CEMS ignores cost and technical applicability. The commenter (0142) stated that the 

requirements may not result in environmental benefits and may lead to high costs for 

implementation of inappropriate and unreliable technology. The commenter (0142) argued that 

CEMS requirements should be revisited at the 8-year review. At that point, EPA may have some 
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information on the cost, efficacy and reliability of these systems as applied to PVC MACT 

sources.

Response to comment 10.1.4.1: While we disagree with the commenter‘s suggestions that 

CEMS are costly and unreliable, the comments are moot, as the final rule does not require CEMS 

use. Our experience is that many source owners or operators find the flexibility and certainty 

afforded by CEMS use well worth their cost, and we encourage source owners and operators to 

continue to explore the benefits of CEMS use.

Comment 10.1.4.2: A commenter (0142) agreed with existing source option for CEMS, 

periodic testing or CPMS. The commenter (0142) stated that the regulatory flexibility allows 

existing sites to select the most appropriate, cost-effective compliance method. 

Response to comment 10.1.4.2: We appreciate the commenter‘s support for the rule‘s 

monitoring flexibility.

Comment 10.1.4.3: One commenter (0142) argued that EPA should base compliance on 

daily average parameter values. The commenter (0142) stated that three-hour block averaging for 

parameters being monitored using a continuous parameter monitoring system is inconsistent with 

most other part 63 NESHAP. The commenter (0142) added that most part 63 NESHAP allow for 

use of a daily average value when demonstrating compliance with continuous monitoring system 

requirements (for example, fire box temperature for a thermal oxidizer). To be consistent with 

other part 63 NESHAP, the commenter (0142) recommended using a daily average for 

demonstrating compliance with continuous monitoring parameters. Alternatively, the commenter 

(0142) stated that at a minimum, EPA should specify that if the control device is already 

governed by another MACT standard, the averaging time specified under that MACT standard is 

controlling. The commenter (0142) stated that EPA should update the following regulatory 

sections and Table 6 of the proposed rule to allow for daily average data averaging periods for 

parameters monitored on control equipment rather than three-hour data averaging periods: 

§63.11890 What are my additional general requirements for complying with this subpart?

(d) (3) When a 3-hour block daily average from a continuous emissions monitor, as 

required by §63.11925(c), exceeds an emission limit in Table 1 or 2 to this subpart
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§ 63.11925 What are my initial and continuous compliance requirements for process 

vents?

(d)(4) For each emission limit for which you use a CEMS to demonstrate compliance, 

you must demonstrate initial compliance with the emission limits in Table 1 or 2 to this 

subpart based on 3-hour block daily averages of CEMS data collected at the minimum 

frequency specified in §§ 63.11935(b)(2) and 63.11890(c), and calculated using the data 

reduction method specified in § 63.11935(e). For a CEMS used on a batch operation, you 

may use a data averaging period based on an operating block in lieu of the 3-hour daily 

averaging period. (e)(3)(ii) You must demonstrate continuous compliance with the 

emission limits in Table 1 or 2 to this subpart based on 3-hour block daily averages of 

CEMS data, the minimum data collection frequency specified in §§ 63.11935(b)(2) and 

63.11890(c), and the data reduction method specified in § 63.11935(e). For a CEMS used 

on a batch operation, you may use a data averaging period based on an operating block in 

lieu of the 3- hour daily averaging period.

§ 63.11985 What notifications and reports must I submit and when? 

(b)(4)(i)(A) For CEMS, the 3-hour block daily average value calculated for any period 

when the value is higher than an emission limit in Table 1 or 2 to this subpart or when the 

value does not meet the data availability requirements defined in § 63.11890(c). 

(b)(5)(iv)(C) The frequency and content of monitoring, recording, and reporting if 

monitoring and recording is not continuous, or if compliance reports, as specified in 

paragraph (b)(4)(i)(A) of this section, will not contain 3-hour block daily average values 

when the monitored parameter value does not meet the established operating limit. The 

rationale for the proposed monitoring, recording, and reporting system must be included.

TABLE 6 TO SUBPART HHHHHHH OF PART 63—OPERATING PARAMETERS, 

OPERATING LIMITS, AND DATA MONITORING, RECORDING, AND 

COMPLIANCE FREQUENCIES FOR PROCESS VENTS, STRIPPED RESIN, AND 

WASTEWATER - Delete all references to ―3-hour block‖ in this table and replace with 

―daily averages.‖

Response to comment 10.1.4.3: The rule retains 3-hour block average parameter 

monitoring, remaining consistent with the 3-hour averaging period of the existing vinyl chloride 
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NESHAP. Should an owner or operator wish to rely on just one averaging period,, he or she 

could submit an alternative monitoring request to the Administrator in accordance with §63.8(f). 

Comment 10.1.4.4.: One commenter (0151) requested clarification on how to establish 

batch operation conditions for the regulated HAPs that are consistent with §63.11945(b) and (c), 

which require that performance testing must be done at the ―absolute worst-case conditions or 

hypothetical worst-case conditions‖.

Response to comment 10.1.4.4: As provided in the rule, a source owner or operator is 

required to conduct performance testing for vents using conditions that provide for the most 

challenging conditions for the control device. For a unit with batch process operations, 

§63.11945(c)(3) requires the source owner or operator is to determine the worst-case emissions 

profile for the vent to the control device. Should a source owner or operator have emissions test 

data, he or she must follow the instructions in §63.11945(c)(1)(i) or §63.11945(c)(1)(ii) to 

determine absolute worst-case conditions. In addition, a source owner or operator must follow 

the instructions in §63.11945(c)(3)(ii) or §63.11945(c)(3)(iii) to determine hypothetical worstcase conditions. The source owner or operator must then conduct performance testing under the 

conditions, whether absolute or hypothetical that provides maximum emissions.

Comment 10.1.4.5: One commenter (0153) requested that §63.11950 be deleted. As an 

alternative, the commenter requested clarification regarding how §63.11950 applies to a PVC 

plants and what equipment it was intended to control. The commenter (0153) questioned the 

extent to which the section was intended to overlap with any batch vents, such as ones that use 

controls to meet the VCM limit that also control other organic HAPs.

Response to comment 10.1.4.5: We disagree with the commenter‘s suggestion to remove 

§63.11950 from the rule, for that section contains the equations that source owners or operators 

are to use to determine emissions profiles from selected activities. Engineering assessments are 

to be used to determine emissions profiles from other activities, per §63.11950(i). As mentioned 

in §63.11925(g)(1)(ii), the procedures in §63.11950 are to be used to determine the emissions 

profile from batch process vents.

HCl CEMS
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Comment 10.1.4.6: One commenter (0146) contended that EPA should remove the HCl 

CEMS requirement from the rule and only require CPMS for continuous compliance. Another 

commenter (0153) stated that an HCl CEMS requirement is premature until the technology is 

available. 

One commenter (0153) contended that if new plants require HCl CEMS, accuracy 

limitations must be factored into emission limits as they were for the Portland Cement MACT 

due to FTIR Method 321 limitations. The commenter (0153) added that there is little point in 

installing a CEMS if all the values are below the limits of detection. 

Two commenters (0146, 0153) argued that it is unclear whether current HCl CEMS 

technology can demonstrate compliance with the proposed new plant limits. A commenter 

(0153) stated that they are not aware of any PVC facilities using HCl CEMS. The commenter 

(0153) contended that if there are other sites reliably measuring HCl in wet stacks at levels below 

80 ppb, EPA must add that information to the record. If not, EPA must set the new plant HCl 

standard at a level that a HCl CEMS can accurately measure or not require HCl CEMS for new 

plants. Commenters 0146 and 0153 stated that it is also unclear whether the required accuracy is 

available from the proposed stack test specified in Method 26A. One commenter (0146) argued 

that EPA should re-evaluate the HCl CEMS cost estimate. The commenter (0146) stated that 

EPA estimated cost for initial installation of HCl/O2 CEMS using the EPA CEMS estimator is 

$165,635. [The costs are reported in 2007 dollars.] The commenter (0146) added that EPA

annualized cost over 10 years including 7% interest, annual certifications, recordkeeping, and 

reporting, is $50,897; these costs are based on installation at an existing facility, addition of one 

new platform, and no CEMS currently being installed. The commenter (0146) added that the cost 

for THC/O2 CEMS under the same assumptions is roughly the same; for installation of both 

monitoring systems, the initial cost would be $189,909 with an annualized cost over 10 years of 

$59,686. The commenter (0146) stated that beyond 10 years, the projected annual cost for 

operation, maintenance, and reporting for the CEMS is estimated at $27,310. None of these 

values have been adjusted for inflation.

Response to comment 10.1.4.6: In the final rule, we are not requiring HCl CEMS but are 

providing for HCl CEMS as a compliance option once performance specifications specific to 

HCl are promulgated. See section V.G of the preamble to the final rule for additional explanation 

and rationale.
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Comment 10.1.4.7: One commenter (0153) stated that paragraph (b)(6)(i) refers to 

minimum accuracy and calibration requirements that do not exist. Another commenter (0146) 

stated that no performance specification is available for HCl CEMS, and it is unclear what 

periodic Relative Accuracy tests will be needed and the cost for conducting those tests. The 

commenter (0146) added that the proposed rule does not specify the instrumentation principles 

of the HCl monitoring equipment n addition, the commenter would ultimately like the HCl 

CEMS requirement removed. The commented (0146) stated that though the measurement range 

of HCl CEMS should be able to reasonably show compliance with the proposed 150 ppmvd limit 

for existing units, it is unclear whether the current technology can demonstrate compliance with 

the proposed new plant limit of 0.17 ppmvd. The commenter (0146) recommended that EPA 

remove CEMS for HCl and only require a CPMS approach for continuous compliance 

determination. Another commenter (0153) stated that they are not aware that EPA‘s Advanced 

Monitoring Systems Center has published any verification studies using this monitoring 

technology for wet gas streams. 

Response to comment 10.1.4.7: While HCl can be measured with FTIR CEMS, which 

have a promulgated Performance Specification (15), we agree with the commenter that there are 

no promulgated performance specifications for CEMS specific to HCl; for this reason, the rule 

no longer requires use of HCl CEMS and the comments are moot.

VCM CEMS

Comment 10.1.4.8: Three commenters (0134, 0143, 0146) stated that EPA should 

continue to allow continuous emissions monitoring (CEMS) for VCM. Some commenters (0141, 

0143, 0146) stated that VCM CEMS have been in use for the last 35 years. Commenters (0134 

and 0146) argued that monitors provide real time emissions data, and commenters (0134 and 

0143) added that since monitors provide real time data, CEMS should be allowed in lieu of 

CPMS for thermal oxidizers, eliminating the need for less direct parameter monitoring. 

Commenters (0134, 0141) stated that any steps taken to control VCM in the TO outlet will also 

control the other organic HAPs as well. They (0141, 0146) argued that VCM CEMS provides the 

best indication of control equipment performance. The commenter (0146) described how bond 

enthalpy analyses can be used to predict the destruction of other HAP based on the destruction of 

VCM. Commenters (0141, 0146) also added that real time emissions monitors are preferred by 

EPA and the general public. 
10-37

Several commenters (0134, 0141, 0143, 0146) contended that with VCM CEMS, stack 

testing for total HAP or total hydrocarbons should be required every five years. Some 

commenters (0141, 0143, 0146) stated that with VCM CEMS, VCM stack testing should no 

longer be required.

Three commenters (0141, 0143, 0146) contended that EPA did not provide a rationale for 

the removal of VCM CEMS in the proposed rule. A commenter (0146) stated that, at the June 

30th, 2011 EPA and Working Group Meeting, EPA indicated VCM CEMS were not incorporated 

due to the lack of a readily available performance standard. The commenter (0146) expressed 

confusion, stating that a 1985 EPA review of CEMS and CPMS monitors found that both types 

of monitors tested in the field were reasonably accurate in the 2-10 ppm range. The commenter 

(0146) noted that they understand accuracy limitations; however, local and state air agencies 

would not allow for the discontinuation of VCM CEMS. 

Several commenters (0141, 0143, 0146, 0153) argued that the final PVC MACT rule 

must allow for the continued use of existing vinyl chloride continuous emission monitoring 

system ("CEMS"), with an option to substitute a total hydrocarbon ("THC") CEMS, similar to 

the existing vinyl chloride NESHAP. The commenters stated (0143, 0146, 0153) that continuous 

vinyl chloride monitoring equipment has been used on process vents for the last 35 years and 

EPA has presented no reason for why the current CEMS requirement has been removed from the 

proposed rule. Two commenters (0143, 0153) added that even if the rule is silent on these 

monitors, it is unlikely that state agencies would allow PVC plants to discontinue their use.

Several commenters (0146, 0153) stated that emission monitors yielding real time 

emission data are typically a preferred approach by EPA and the public. A commenter (0153) 

stated emission monitors are generally accurate and economical. Commenters (0146, 0153) 

stated that EPA personnel indicated verbally that continuous vinyl chloride monitors were not 

incorporated into the proposed rule because a performance specification was not readily 

available for use; however, based on the 1985 EPA Environmental Systems Monitoring 

Laboratory (EPA/600/S4-85/037) review, these monitors were reasonably accurate in the 2–10 

ppm range. The commenter (0153) added that manufacturer‘s specifications can also be used to 

maintain and calibrate these monitors. The commenters (0146, 0153) stated where continuous 

vinyl chloride monitors are used, they provide a very good indicator of (0146, 0153) proper 

thermal oxidizer operation or (0146) absorber operation. Vinyl chloride as measured by our 

current monitors is the best existing indicator of whether (0153) our control processes and (0146) 
10-38

control equipment (oxidizers and absorbers) are functioning properly. The commenters (0143, 

0146, 0153) concluded stating that where existing real time vinyl chloride monitors are used, 

(0143, 0146) VCM stack testing is not needed or (0153) facilities should be exempt from the 

requirement to conduct VCM stack tests and, (0146, 0153) no other frequent TOH/THC stack 

testing or (0143, 0146, 0153) CPMS is needed and stack testing for TOH/THC should only be 

required once every five years.

Response to comment 10.1.4.8: We find the commenters‘ view regarding the existence of 

vinyl chloride (VC) continuous emissions monitoring systems (CEMS) mistaken. The VC 

NESHAP requires a VC monitoring system, not VC CEMS for major leak detection (see 

§61.65(b)(8)(i)) and for emission monitoring (see §61.68(a)). Source owners and operators 

subject to that rule are to propose an instrument operations program acceptable to the 

Administrator for major leak detection and to propose a daily span check with a span of 10 parts 

per million (ppm) for emissions monitoring. Since neither type of VC monitoring system 

contains the complete components associated with a performance specification, examples of 

which can be found in Appendix B of 40 CFR part 60, the VC monitoring system mentioned by 

the commenters and required by the VC NESHAP is not a VC CEMS. 

While we prefer use of CEMS when available, the rule does not include VC CEMS 

because there are no promulgated performance specifications for VCM CEMS. Moreover, we 

believe existing VC monitoring systems may have difficulty accurately measuring emissions for 

three of the four process vent emissions limits because the VC monitoring systems were 

designed for an emissions limit of 10 ppm, some 9 times larger than these rule limits. More 

specifically, the EPA document cited by the commenters bolsters our belief, as it notes ―...when 

the combustion level dropped to below 1 ppm in the sampling line, the relative accuracy became 

far worse (approximately 30%)...,‖ which is some 50% larger than the most generous relative 

accuracy allowed in performance specifications and three times as large as the reported relative 

accuracy for VC concentrations between 2 and 10 ppm. Even though commenters provided no 

data to support the present availability of monitoring systems that can provide accurate 

measurements at low levels, should such systems exist, a source owner or operator would be able 

to submit to the Administrator an alternative monitoring request to use such a system, in 

accordance with §63.8(f).

We have no control over local, state, or tribal air agencies who act according to their own 

authority for a program, so a state agency may not allow an owner or operator to discontinue 
10-39

existing vinyl chloride monitoring. We agree that ongoing, periodic emissions testing apart from 

RATAs for units subject to CEMS requirements is redundant, and, as shown in §63.11925(e)(4), 

the rule has been revised to require ongoing, periodic emissions testing only from those units not 

using CEMS to demonstrate compliance.

CPMS – Calibration frequency and feasibility

Comment 10.1.4.9: Two commenters (0142, 0153) requested that EPA allow calibrations 

of CPMS monitoring equipment based on generally accepted good engineering practices and 

manufacturer‘s recommendations. Both commenters (0142, 0153) contended that the annual 

calibration requirements in Table 8 are not reasonable given normal operating and turnaround 

practices and manufacturer‘s recommendations. One commenter (0153) stated that the proposed 

calibrations schedule is too frequent for some applications (e.g., calibrating some pH meters 

every 8 hours). One commenter (0142) indicated that annual inspection of flow rate, 

conductivity, and pressure monitors for mechanical integrity and electronic error logging is 

achievable; however, straight calibration is not. Both commenters (0142, 0153) contended that, 

for most of these instruments, calibration will require removal of the device and transfer to an 

appropriate facility. One commenter (0142) indicated that this type of activity would have to be 

performed during facility turnarounds, and that turnarounds are typically scheduled at 3 year 

intervals, not annually. The commenter (0142) expressed concern that, in order to meet the 

proposed calibration requirements, piping and instrumentation would have to be redundant in 

order to allow removal of the device while the facility is in operation. The commenter (0142) 

stated that, in many instances, calibration requires the removal of the device, which in turn 

requires a shutdown of the process, and that many sources do not routinely shut down their 

process equipment or air pollution control equipment on an annual basis. The commenter (0142) 

further explained that this is especially true when the control device is used by more than one 

source. The commenter (0142) argued that mandating an annual shutdown would require the 

clearing and cleaning of equipment in preparation for maintenance, which introduces more 

opportunities for excess emission events.

Response to comment 10.1.4.9: We disagree with the commenter‘s assertions that CPMS 

calibration is unreasonable or too difficult to perform annually, as well as more frequently for pH 

monitors. Since parameter monitoring is at least one step removed from direct emissions 
10-40

measurement, one must be certain that the values obtained from the parameter monitoring, both

initially and on an ongoing basis, remain comparable over time. Showing that the monitoring 

system continues to operate properly, in that it responds as expected, or, in other terms, it 

remains calibrated is paramount. The rule‘s frequencies for ensuring that the instrumentation 

and the system remain appropriate are the minimum we expect to be practical, as well as 

workable. Note that we seek verification that the monitoring system continues to perform well; 

such verification could come from comparisons to a redundant monitoring system (as mentioned 

by one commenter), from an established program of frequent sensor replacement, as well as via 

what the commenters refer to as a ―straight calibration.‖ Of course, should an owner or operator 

desire to use a different technique, he or she is able to submit an alternative monitoring request to 

the Administrator in accordance with §63.8(f).

Comment 10.1.4.10: One commenter (0142) argued that EPA should not specify a 

calibration frequency (or, in some instances, specify calibration at all) for temperature and flow 

rate monitors, considering modern instrument technology and generally accepted good 

engineering practices. The commenter (0142) explained that, historically, temperature devices 

such as thermocouples required periodic verification (which is not the same thing as 

―calibration‖) because of the cold junction compensators, and that it would not have been 

possible to ―calibrate‖ the thermocouples as they have no adjustment mechanism. The 

commenter (0142) explained that, rather, the appropriate practice would have been to dispose of 

thermocouples that fail verification, and replace them with new thermocouples; so, even for 

these devices, a ―calibration‖ requirement would be inappropriate. 

The commenter (0142) further contended that annual calibration of passive temperature 

devices such as platinum resistive thermal devices (RTD‘s) is inappropriate, as, not only do these 

devices lack an adjustment mechanism (so that they cannot actually be ―calibrated‖), but they 

also rarely ever fail. Consequently, the commenter explained, replacement of an RTD is a very 

infrequent (not annual) task, and replacing RTDs every year would be a waste of money. The 

commenter (0142) continued that, when an RTD does fail, it does not just drift to a slightly 

higher or lower value than the true temperature, which is the type of failure that ―calibration‖ is 

intended to address; rather, RTDs fail all at once (full scale high or low). The commenter (0142) 

argued that a more reasonable reliability strategy for RTDs, based on good engineering practice, 

is the periodic replacement of the device, but not necessarily annually. 
10-41

The commenter (0142) further explained that many other temperature or flow 

measurement devices are designed with ―smart‖ electronics which offer continuous diagnostic 

checks as a verification that the device is operating properly. The commenter (0142) argued that 

―calibration‖ may not be needed for these devices; rather, at most it might be appropriate to 

check the diagnostic routines and verify that they are functioning as intended. The commenter 

stated that this would not be a ―one size fits all‖ requirement. The commenter (0142) further 

stated that, in instances where redundant devices are installed, the ability to cross check 

measured values against one another is adequate as a validation of proper operation, and, as a 

result, it may not be necessary to ―calibrate‖ these devices on the same schedule as a ―nonredundant‖ device that operates on its own.

Response to comment 10.1.4.10: We disagree with the commenters‘ suggestions that 

temperature and flow rate minimum calibration requirements need not be provided in the rule. 

As mentioned earlier, since parameter monitoring is at least one step removed from direct 

emissions measurement, one must be certain that the values obtained from the parameter 

monitoring, both initially and on an ongoing basis, remain comparable over time. Showing that 

the monitoring system continues to operate properly, in that it responds as expected, or, in other 

terms, it remains calibrated is paramount. The rule‘s frequencies for ensuring that the 

instrumentation and the system remain appropriate are the minimum we expect to be practical, as 

well as workable. Note that we seek verification that the monitoring system continues to 

perform well; such verification could come from comparisons to a redundant monitoring system 

(as mentioned by one commenter), from an established program of frequent sensor replacement, 

as well as via what the commenters refer to as a ―straight calibration.‖ Of course, should an 

owner or operator desire to use a different technique, he or she is able to submit an alternative 

monitoring request to the Administrator in accordance with §63.8(f).

CPMS – Selection of Monitored Parameters

Comment 10.1.4.11: Two commenters (0139, 0142) discussed the requirements for 

continuous monitoring in Table 6 of the proposed rule and stated that many of these parameters 

are not normal, necessary, or meaningful in assuring the proper operating of the air pollution 

control device. Commenters (0139, 0142) provided reasoning why pH or pressure drop in a 

packed bed column should not be used for demonstrating compliance. The commenter (0142) 

added that it is difficult, if not impossible, to establish a reasonable set of conditions that would 
10-42

establish the absolute minimum and maximum range of operation during a performance test, 

given the number of required parameters. The commenter (0142) requested that parameter 

monitoring for various air pollution control devices follow regularly accepted good engineering 

practices and that Table 6 listed parameters be provided as options and not absolutes. The 

commenter (0142) presented a detailed discussion about the problems associated with pressure 

drop, regeneration stream flow, and minimum and maximum absorber bed temperature.

Another commenter (0153) contended that the rule should allow for alternative 

combinations or operating parameters that may be more appropriate for new or specific control 

equipment designs; for example, measuring pressure drop may not be an effective monitoring 

parameter for low energy scrubbers. The commenter (0153) added that EPA must clarify which 

of the Table 6 operating limits apply to any given piece of equipment. The commenter (0153) 

asked if Table 6 was a list to select from or must all the items be in place? 

Response to comment 10.1.4.11: We disagree with the commenters‘ assertions regarding 

the usefulness of monitoring parameters. While we agree with the commenters that not all 

parameters associated with use of a particular emissions control device or technique can be 

related directly to an emissions limit, we do not agree that ignoring data associated with the 

parameters ensures that the control devices or techniques continue to operate the way that they 

did during performance testing that demonstrated compliance with emissions limits. The rule‘s 

requirements for continuous operating parameter data remain (See Table 7 of subpart 

HHHHHHH). As with any monitoring requirement, should a source owner or operator choose to 

use a different parameter than is contained in the rule, he or she is able to submit an alternative 

monitoring request to the Administrator in accordance with §63.8(f).

Comment 10.1.4.12: One commenter (0139) proposed that continuous VCM emissions 

monitoring, stack testing for HAPs and work practices to limit iso-octane emissions from an 

absorber column are appropriate in lieu of continuous monitoring under the proposed MACT. 

The commenter (0139) stated that they do not believe that §63.11940(c), (d), or (e), should apply 

to the VGA. The commented (0139) added that the continuous VCM monitor should be 

sufficient for demonstrating compliance with the rule. The commenter (0139) concluded that a

work practice standard of tracking iso-octane additions to the VGA recovery device over time 

should verify usage and eventual loss.
10-43

Response to comment 10.1.4.12: We disagree with the commenter‘s suggestions. 

Infrequent emissions or associated parameter evaluations or work practices do not provide the 

same level of assurance as continuous monitoring, whether emissions or parameter. This portion 

of the rule remains unchanged. To the extent adsorbers and acid gas scrubbers or regenerative or 

non-regenerative adsorbers are not used, then the rule‘s monitoring requirements for them are not 

necessary. Finally, the commenter provided no data to support his contention of equivalency 

using a work practice standard; should he or she believe this activity is appropriate, he or she 

should prepare an alternative monitoring request to the Administrator in accordance with 

§63.8(f).

Comment 10.1.4.13: One commenter (0121) stated that the term flow indicator is used in 

various locations in the proposed rule. The commenter (0121) asserted that, Table 8 of the 

proposed rule specifies calibration and accuracy requirements for sources monitoring liquid flow 

rate or gas flow rate parameters. The commenter (0121) requested that where it is more 

appropriate, the proposed rule be revised to require flow meters. The commenter (0121) stated 

that the proposed rule at 40 CFR 63.11940(a) states, "if flow to a control device could be 

intermittent, you must install, calibrate, and operate a flow indicator at the inlet or outlet of the 

control device to identify periods of no flow." The commenter (0121) requested that the 

proposed regulation be revised to require flow meters or combinations of flow meters and flow 

indicators. The commenter (0121) explained that continuous records of flow to a control device 

may be utilized in accessing performance and compliance. The commenter (0121) contended that 

this is consistent with other federal requirements. The commenter (0121) referred to 40 CFR 

60.107(a)(e). 

Response to comment 10.1.4.13: We disagree with the commenter‘s suggestion. While a 

flow meter could serve as a flow indicator, other types of flow indicators would work equally 

well. The rule retains use of flow indicators.

CPMS - Miscellaneous

Comment 10.1.4.14: One commenter (0139) contended that the requirement to prepare 

and submit a CMS Quality Control Program and test plan should be removed. The commenter 

(0139) stated that it is overly burdensome to require the preparation and submittal of CMS plans 

to the agency for approval. The commenter (0139) added that each regional EPA office is likely 
10-44

to have different interpretations of the requirements and uniformity in enforcing requirements to 

different companies fostering a non-competitive atmosphere is important to the industry. The 

commenter (0139) concluded that delayed response by the agency leaves the company to guess 

whether the plan is adequate.

Response 10.1.4.14: We find the commenter‘s contention to be misplaced. While 

§63.11935(b)(1) of the rule requires source owners or operators who use CEMS to prepare 

quality control programs and test plans, only performance evaluation test plans are to be 

submitted to the Administrator for approval. Likewise, while §63.11935(c)(1) of the rule 

requires source owners or operators who use CPMS to prepare a site-specific monitoring plans, 

those plans are only required to be submitted to the Administrator upon specific requests by the 

Administrator. Rather than being just burdensome, we find that limiting our review and approval 

to those instances of importance is an appropriate way to exercise our discretion in managing the 

program and that plan development provides a tangible means for source owners or operators to 

discuss, understand, and implement their compliance monitoring strategies. Should source 

owners or operators experience delay or inconsistencies within the Agency, they could develop 

alternative monitoring requests to the Administrator in accordance with §63.8(f).

Comment 10.1.4.15: One commenter (0144) stated that there are no regulator provisions 

promulgated by EPA for conducting performance evaluation for CPMS. The commenter (0144) 

stated that this could potentially lead to confusion with different facilities having different 

performance evaluation schemes governing CPMS evaluations. The commenter (0144) 

suggested that EPA should base the performance of the CPMS on conformance to 

manufacturer‘s recommendations in terms of ongoing maintenance and calibration. The 

commenter (0144) added that those recommendations could be documented in the site specific 

monitoring plan, which then would be followed by the subject facilities.

Response to comment 10.1.4.15: We disagree with the commenter, finding his suggestion 

to allow use of various manufacturers‘ recommendations would lead to more, not less, 

inconsistency. The rule establishes minimum elements for ongoing quality assurance and control 

requirements, and the rule leaves specific implementation details to individual source owners or 

operators, who develop quality control programs that incorporate the minimum elements. We do 

not intend to relinquish a source owner or operator‘s flexibility to choose how to accomplish 

specific program minimums.
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Comment 10.1.4.16: One commenter (0153) expressed concern regarding the impacts 

associated with the proposed CPMS requirements for temperature, pressure, volumetric flow 

rate, mass flow rate, and conductivity, including 1) the requirement that monitoring equipment 

must be capable of measuring the parameter over a range that extends at least 20 percent beyond 

the normal expected operating range of values for the parameter; (2) the data recording system 

associated with affected CPMS that must have a resolution that is equal to or better than one-half 

of the required system accuracy; and (3) specified calibration frequencies for parametric 

monitoring systems. The commenter (0153) referred the EPA to Attachment G of their comment 

letter, which includes the commenter‘s previous February 4, 2009 comments on the prior 

proposed CPMS rulemaking which enumerates some of these concerns. The commenter (0153) 

stated they have not been able to evaluate their equipment in light of §63.11935(c)(5), referring 

to parameters to monitor, ranges, and resolution. The commenter (0153) stated that no cost 

estimates are included for upgrading equipment. 

Response to comment 10.1.4.16: We disagree with the commenter‘s concerns over 

minimum monitoring equipment characteristics and calibration frequencies. In order to ensure 

that monitoring equipment continues to provide valid data to show that emissions are not 

exceeded, that equipment needs to be able to accurately measure inputs over the range of 

expected values and at an appropriate resolution; the rule provides such minimum ranges and 

resolutions, along with calibration and inspection frequencies. With respect to Attachment G, in 

that document the commenter bases his concerns on parametric monitoring associated with 

another rule (the hazardous waste combustion MACT). Moreover, in Attachment G, the 

commenter requests annual calibration checks for parameter monitoring, which is what this rule 

provides except for pH monitors, of which the commenter reports as having 2. Notwithstanding 

the commenter‘s suggestion to the contrary, average costs for parameter monitoring were 

considered and included in cost assessments associated with the rule. Should parameter 

monitoring costs pose a problem for owners or operators, they are able to submit alternative 

monitoring requests to the Administrator in accordance with §63.8(f).

Comment 10.1.4.17: One commenter (0153) stated he was not in favor of specified 

calibration frequencies for parametric monitoring systems, instead, manufacturer‘s recommended 

frequencies as well as experience in a specific application should dictate the minimum 
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frequency. For example, the commenter (0153) stated that specifying calibration of pH meters at 

8 hours is too frequent for some applications. The commenter (0153) stated additional concerns 

about what methods will be required to do the calibrations and accuracy determinations. The 

commenter (0153) added that it may be that some flow meters can only be calibrated by removal 

and sending them to a factory or other offsite location. The commenter (0153) provided 

additional comments as an attachment which enumerates some of their concerns. 

Response to comment 10.1.4.17: While we acknowledge that some manufacturers can 

provide useful calibration information including recommended frequencies, not all 

manufacturers supply such information and not all manufacturers provide all elements of a 

program to ensure minimally acceptable continuing performance of their products. The rule 

requires these elements to be provided on a consistent basis. Should source owners or operators 

remain concerned about these minimum elements, they can submit alternative monitoring 

requests to the Administrator in accordance with §63.8(f).

Comment 10.1.4.18: Two commenters (0142, 0153) stated that the proposed calibration 

schedule for pH meters (every 8 hours of process operation check the pH or caustic strength 

meter‘s calibration on at least two points) is too frequent, unreasonable, and not consistent with 

manufacturer‘s recommendation, and that pH monitors be calibrated according to manufacturer's 

specifications or other written procedures that provide adequate assurance that the equipment 

would reasonably be expected to monitor accurately. One commenter (0142) stated that 

calibration typically involves removing the pH probe from the process and checking the 

measurement of the device at the process computer or transmitter against a known standard. The 

commenter (0142) explained that this activity involves the temporary bypass or disruption of the 

process control system and potential exposure of personnel to both process and calibration 

liquids, and requiring that personnel complete this task three times per day, every day, is 

unnecessary given the known reliability of the device and the potential personal and process 

safety risks.

Response to comment 10.1.4.18: We disagree with the commenters‘ suggestions that pH 

monitors be calibrated only according to manufacturer‘s specifications or other written 

procedures, in lieu of the simple, consistent approach contained in the rule. While the 

commenters suggested manufacturer‘s specifications or written procedures, as well as the known 

reliability of pH monitors, would provide the assurance of compliance that sources continue to 
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meet emissions limits, the commenters supplied no data to support those claims. Should an 

owner or operator be concerned about temporary bypass or disruption of the process control 

system or potential exposure to workers, he or she could submit an alternative monitoring 

request to the Administrator in accordance with §63.8(f), to allow installation and use of 

redundant pH monitors, for direct comparison of redundant monitor outputs should serve as an 

ongoing calibration check.

Comment 10.1.4.19: One commenter (0139) proposed that the backup thermal oxidizer 

(TO) at their Pedricktown and Henry sites be excluded from the CPMS and recordkeeping 

requirements. The commenter (0139) stated that the back up TO‘s are only operated for a limited 

number of hours per year for maintenance and repair of the vent gas absorbers (VGA‘s) and the 

hours allowed for operation of the TO‘s are limited by a federally enforceable Title V permit at 

each facility. Another commenter (0153) added that if a site qualifies more than the minimum 

CPMS instruments during the performance test, EPA should allow the secondary devices to be 

used in case the primary device malfunctions; these backup devices should not be subject to 

deviation reporting, unless they are being operated as primary devices and a malfunction occurs.

Response to comment 10.1.4.19: We disagree with the commenter‘s suggestion that 

backup emissions control devices be excluded from monitoring and recordkeeping requirements, 

for the backup emissions control devices are needed to ensure emissions limits are not exceeded

at any time. Should a source owner or operator wish to pursue such an exclusion based on site 

specific operation, he or she should submit an alternative monitoring request to the Administrator 

in accordance with §63.8(f). The second commenter‘s suggestion is unclear; if the commenter 

means that a source has two redundant monitors, keeps both monitors maintained and quality 

assured, but uses one as a primary and only engages the other (the secondary one) when the 

primary one malfunctions, we would agree that a properly operated and maintained redundant 

monitor used only when the primary monitor malfunctions need not be subject to deviation 

reporting when it is not used. On the other hand, if the commenter means that a source has two 

differing types of monitors (one type used as a primary monitor and the other used as a 

secondary monitor) each of which is used to assess compliance independently, then we disagree 

with the commenter‘s suggestion that data from the secondary monitor be ignored except when 

the primary monitor malfunctions. As each monitoring system could be used to assess 
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compliance independently, one system not showing compliance would be relevant for 

compliance purposes.

Comment 10.1.4.20: One commenter (0153) stated that they have not been able to 

evaluate the impact of reducing operating data to one-hour averages and CEMS data to threehour averages within the allotted comment period. Another commenter (0142) contended that 

EPA should base compliance on daily average parameter values, or as an alternative, if the 

control device is regulated by another MACT standard, the averaging time specified under that 

MACT standard. The commenter (0142) provided several examples of the proposed regulatory 

text where references to ―3-hour block‖ averages should be replaced with ―daily averages.‖ 

Response to comment 10.1.4.20: As mentioned earlier, we disagree with the commenter, 

since many, if not all, of these sources rely on batch processing that lasts a few hours, not days. 

The rule retains 3-hour block average parameter monitoring, remaining consistent with the 3-

hour averaging period of the existing vinyl chloride NESHAP. Should an owner or operator 

wish to rely on just one averaging period, he or she could submit an alternative monitoring 

request to the Administrator in accordance with §63.8(f).

Comment 10.1.4.21: Three commenters (0141, 0143, 0146, 0153) argued that EPA 

should give preference to recovery devices in lieu of destructive technology. The commenters 

(0141, 0153) described benefits of recovery devices: return material to the process, minimal 

HAP and criteria pollutant emissions, and generation of useful materials. The commenters (0141, 

0146, 0153) contended that EPA should not discourage the use of recovery devices by imposing 

CPMS requirements. The commenters (0141, 0146, 0153) stated the agency previously 

recognized the benefits of regulating recovery devices differently from control devices in several 

existing MACT standards, including the HON and the MON. The commenters (0141, 0146, 

0153) noted that in the MON preamble EPA states ―In the proposal we recognized that the 98% 

control requirement for all process vents with the affected processes would force incineration, 

and this might not be appropriate for all process vent streams. Therefore, we also allowed 95% 

reduction of process vents if ―recovery‖ control technology was employed to achieve required 

reductions.‖ [68 FR 63858 (November 10, 2003).] 

One commenter (0146) contended that compliance options for control and recovery 

equipment should include concentration, mass, or percentage removal limits, all based on the 
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five best performing facilities. The commenter (0146) stated that emission limits set exclusively 

on a concentration basis are an unfair measure of performance for some low flow recovery or 

control devices. Both types of devices can be regulated with a flexible approach to allow use of 

recovery, control, or a combination of technologies. The commenter (0146) added that this 

approach is consistent with Section 4 of Executive Order 13546, Flexible Approaches, which 

states: ―Where relevant, feasible, and consistent with regulatory objectives, and to the extent 

permitted by law, each agency shall identify and consider regulatory approaches that reduce 

burdens and maintain flexibility and freedom of choice for the public. These approaches include 

warnings, appropriate default rules, and disclosure requirements as well as provision of 

information to the public in a form that is clear and intelligible.‖ The commenter (0146) provided 

equivalent performance based limits in a table on page 57 of their comments.

Response to comment 10.1.4.21: We disagree with the commenters that EPA should 

prefer a specific control or recovery device for the PVC rules. The MACT floor emission limits 

do not specify a particular control or recovery device for achieving compliance. We note that the 

rule referenced by the commenters, the MON, used a different format for the standard, i.e., a 

percent reduction requirement, which may have allowed such differentiation. We considered 

setting alternative formats for the process vent emission limits. However, we did not have 

sufficient information provided from industry on process vent stream flow rates and 

concentrations to develop or evaluate other formats, such as mass emission rates. The emission 

limits for process vents apply at the point where the gaseous stream is released to the 

atmosphere. Since the rule does not require that affected sources use a specific control or 

recovery device to meet the process vent limits, a source can use any control or recovery device 

to meet the final standards. However, EPA must ensure that whatever control or recovery devices 

are used demonstrate continuous compliance. Therefore, we are requiring continuous parametric 

monitoring of control device parameters.

10.1.5 Stack Testing

Comment 10.1.5.1: One commenter (0142) argued that the PVC MACT should allow for 

a design evaluation to be used in lieu of a performance test to demonstrate compliance with the 

control requirements for control devices used on small control devices. The commented (0142) 

that this would be consistent with other part 63 NESHAPS. For example, the MON allows the 
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use of a design evaluation or performance test for small control devices as well as control 

devices controlling emissions from storage tanks. The commenter (0142) provided language 

from §63.2450(h). The commenter (0142) suggested adding language to allow the use of a 

design evaluation in lieu of performance testing to the PVC MACT rule by adding the 

appropriate references to the design evaluation criteria in 40 CFR part 63, subpart SS.

Response to comment 10.1.5.1: We disagree with the commenter‘s suggestion to allow 

design evaluations to be used in lieu of performance tests to demonstrate process vent 

compliance. Actual emissions performance, as opposed to theoretical performance, is needed to 

ascertain how well the process vents are being controlled. The rule‘s requirements for 

performance testing remain; however, an owner or operator may submit to the Administrator a 

request to use an alternative test method, as described in §63.7(f), or to waive performance 

testing, as described in §63.7(h), if the owner or operator believes something other than 

performance testing will provide compliance assurance.

Comment 10.1.5.2: One commenter (0153) generally supported the use of Method 26A to 

measure HCl, but requested clarification of how to demonstrate compliance at the proposed new 

source standard limit. The commenter (0153) stated the Shintech Addis value measured with an 

FTIR instrument set the new source limit at 0.085 ppmvd (0.126 ug/dscm). The commenter 

(0153) added they do not believe that level of detection can be demonstrated in a new plant using 

Method 26A, noting the ASME report referenced in this rule (footnote, page 29546) indicates 

that + or – 20% random error will result at true stack HCI concentration of 1000 ug/dscm using 

Method 26A. The commenter (0153) stated there is little chance that Method 26A will be able to 

accurately measure compliance at that level and if the agency sets any limits at levels below 

limits of detection of the specified methods, EPA must clarify exactly how compliance will be 

determined.

Response to comment 10.1.5.2: EPA disagrees that Method 26A is not capable of 

showing compliance with the new source limit. As stated in Method 26A, the typical method 

detection limit for a sample volume of 1 dscm would be approximately 0.04 ppm. The final new 

source emission limits for HCl are 0.17 ppmv for PVC-only process vents and 1.4 ppmv for PVC 

–combined process vents.
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Comment 10.1.5.3: Two commenters (0146, 0153) argued that the stack test methods 

should be expanded to allow those methods to be used to generate the CAA section 114 request 

test data. Commenters (0146, 0153) pointed out that EPA comingled the top five facility data 

from both Method 320 FTIR and Method 0031 summa canister methods, and thus (0153)

additional methods should be allowed without prior approval as long as the results are valid. 

Commenters (0146, 0153) added that Method 18 is specified for measuring compliance and 

(0153) has typically higher detection levels. A commenter (0153) added that the limit of 

detection in Method 18 for vinyl chloride is 0.2 ppm, and any emission limit should not be set 

less than 3 times the non-detect level, or 0.6 ppm vinyl chloride. Commenters (0146, 0153) noted 

that additional circumstances may warrant the use of a different approved test method, (0146) 

such as a new plant needing to achieve lower limits of detection. A commenter (0146) concluded 

that since numerous methods were used to set emission limits, a site should be able to use any 

one of the approved methods without the need to seek alternative approval. 

Response to comment 10.1.5.3: We disagree with the commenters. Some of the methods, 

such as Method 0031, allowed during the information collection period allow the testers and 

laboratories flexibility in the procedures and MQOs/DQOs. In order to use these methodologies 

for compliance, these procedures, MQOs and DQOs must be prescribed. We feel that source

owners or operators wishing to use methods other than those contained in the rule should submit 

a site specific request according to the procedures given in §63.7. 

Comment 10.1.5.4: One commenter (0142) argued that EPA should revise the proposed 

concentration-based limits for vinyl chloride from both existing and new sources because 

Method 18 cannot achieve detection limits and quantification limits low enough to match the 

proposed emission limits. Sections 63.11494(d) and (f) of EPA‘s proposed rule require that EPA 

Method 18 be used to demonstrate compliance with the vinyl chloride requirements. The 

commenter (0142) contended that this is not appropriate, because Method 18 cannot achieve 

detection limits and quantification limits low enough to match the proposed emission limits for 

vinyl chloride from existing sources. The commenter (0142) pointed out that EPA Method 18 

utilizes tubes, bags, or on-line sample collection and analysis by gas chromatography/flame 

ionization detection, and that although tube collection methodology provides the lowest detection 

limits, vinyl chloride has volatility and recovery issues when collected on a tube, limiting the 

options to either on-line or bag sample collection. The commenter (0142) stated that these 
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methods also present difficulties due to the limitations of the GC FID, so that the achievable 

detection limits and quantification limits are not low enough to match EPA‘s proposed emission 

standards for vinyl chloride. The commenter (0142) stated the emission standard for new sources 

is 100 times more stringent, but EPA has chosen the same analytical method. The commenter 

(0142) concluded by stating that EPA should revise the proposed concentration based limits for 

vinyl chloride from both existing and new source because Method 18 cannot achieve detection 

limits and quantification limits low enough to match the proposed emission limits.

Response to comment 10.1.5.4: EPA disagrees with the commenters. Method 18 is not 

limited to any specific detector technology. Other detector technologies such as mass 

spectroscopy (MS) or ECD may be paired with gas chromatography, which would allow for 

lower detection levels for vinyl chloride compared to a flame ionization detector (FID). Source

owners or operators may also request alternative methods per §63.7.

Comment 10.1.5.5: Two commenters (0142, 0143) contended that EPA should not 

require annual performance testing. Four commenters (0141, 0142, 0143, 0146) referred to the 

Boiler MACT rule that requires testing less frequently than annually. One commenter (0141) 

stated the annual stack testing requirement is unreasonable and more burdensome than stack 

testing requirements in other MACT and NSPS rules and state performance testing requirements. 

One commenter (0142) argued that requirements to test process vent emission control devices 

annually to determine compliance with the concentration limits for vinyl chloride, total organic 

HAP, and dioxins/furans in proposed §63.11925(e)(4)(i) exceeds the requirements outlined in 

other MACT rules and is far beyond what is necessary to confirm compliance. 

Two commenters (0142, 0146) argued that the proposed rule requires unreasonable and 

cost-prohibitive annual testing for CDD/CDF in order to demonstrate compliance. A commenter 

(0146) argued that for D/F, the testing requirement for PVC sources should be limited to an 

initial test demonstrating compliance with the limit, with no additional testing, provided the 

unit‘s design is not modified in a manner inconsistent with good combustion practices. One

commenter (0142) stated that EPA should rely on the proposed emission limits combined with 

work practice requirements to minimize the emissions of dioxins/furans.

One commenter (0146) argued that EPA should provide PVC sources with the same 

degree of flexibility for well-performing sources with respect to TOH/THC, considering that 

(0142) the performance of air pollution control equipment does not significantly vary from year 
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to year if it is maintained and operated properly. The commenter (0142) also noted that 

continuous parameter monitoring is required by the rule and assures emission limits are met. 

Another commenter (0146) added that many MACT standards and NSPS require one initial 

performance test (e.g., pulp and paper MACT standards under subparts S and MM), and thus 

these flexible testing strategies for well-performing sources, coupled with work practices to 

conduct annual burner tune-ups and to continuously measure oxygen to assure complete 

combustion, are reasonably appropriate and fully within EPA‘s discretionary authority. Another 

commenter (0142) concluded by stating annual emission testing, especially to the extent required 

by this rule, is costly and is not value added, and thus the frequency of stack testing should be 

reduced to once every five years.

Response to comment 10.1.5.5: We agree with the commenters that annual testing is not 

necessary to ensure compliance with process vent limits at PVC facilities if continuous 

parametric monitoring is required. The final standards provide sources the option to comply with 

continuous parametric monitoring requirements or use CEMS. In the final rule we have revised 

the frequency for conducting performance testing to every five years.

Comment 10.1.5.6: One commenter (0142) suggested the following replacement text for 

§63.11925(e)(4)(i): ―Initial performance testing of air pollution control (APC) devices should be 

required to establish operating parameter levels. You are not required to conduct a performance 

test for an emission point for which a performance test was conducted using the same test 

methods and for which either no deliberate process changes have been made since the test, or the 

owner or operator can demonstrate that the results of the performance test, with or without 

adjustments, reliably demonstrate compliance despite process changes.‖

Response 10.1.5.6: Because we are not requiring annual performance testing, the 

comments are no longer relevant.

Comment 10.1.5.7: Three commenters (0143, 0146, 0153) contended that sources should 

be able to demonstrate compliance with the TOH limit or the THC limit, similar to the approach 

used for Portland Cement. Commenters (0143, 0153) acknowledged TOH compliance would 

require additional methods; noting the methods used would be (0143, 0146) the same, or (0153) 

similar to, the ones used to gather the CAA section 114 request data. Commenters (0143, 0146, 

0153) acknowledged that there are advantages to Method 25A for THC, such as that it is 
10-54

relatively inexpensive to run, has been used in previous New Source Performance Standards, 

captures a wide variety of organics, can be measured with a CEMS device, and may be 

consistent with EPA's current Uniform Standard approach. Commenters (0143, 0146, 0153) 

noted THC also has significant limitations, including the fact that it is not always specific for 

organic HAP and can be affected by methane (natural gas) or other inlet non-HAP organics (e.g., 

ethylene). One commenter (0153) stated that if a source demonstrates compliance with the TOH 

limit, then it is not a deviation even if the THC limit is exceeded. 

Response 10.1.5.7: We reviewed the commenters‘ suggestion to allow compliance to be 

determined based on either a total organic hazardous air pollutant (TOHAP) limit or THC limit, 

and the final rule includes compliance provisions for a TOHAP emissions limit as an alternative 

to the THC emissions limit. We agree with commenters that measurements for TOHAP will 

require additional methods, and we have included use of EPA Method 320 and EPA Method 18 

in the rule. We do not share the commenter‘s concern that THC is not specific for organic HAP 

because as discussed in the Preamble section V.C it is an appropriate surrogate for TOHAP. As 

to the commenter‘s question about which standard to demonstrate compliance with, 

the final rule includes compliance alternatives, and the source must select which alternative it 

intends to meet. That alternative would presumably be documented in the source‘s title V 

permit. 

Comment 10.1.5.8: Two commenters (0143, 0146) recommended that TOH exclude 

dioxin/furan and vinyl chloride, which are considered separately. 

Response 10.1.5.8: The commenters are correct that the total organic hazardous air 

pollutants limit includes both dioxins/furans (D/F) and vinyl chloride. Although we understand 

the commenters‘ request to exclude these pollutants from TOHAP, we do not believe such a step 

is necessary. With respect to dioxins/furans, the contribution is orders of magnitude smaller than 

the other HAP that it would not affect the TOHAP limit. Indeed, dioxin./furan cannot be detected 

using the test methods available to test for organic HAP. With respect to vinyl chloride, we have 

provided a total organic HAP alternative compliance limit for the THC limit for process vents. 

Because we are unable to determine a non-vinyl chloride THC limit, it would be inappropriate to 

set a non-vinyl chloride total organic HAP limit as an alternative compliance limit for the THC 

limit. Our process vent emissions database does not include the individual FIA (flame ionization 

analyzer) response factors to vinyl chloride used for collecting the Method 25A data during the 
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PVC CAA section 114 testing request, so we would not be able to subtract the vinyl chloride 

from the THC emission limit.

Comment 10.1.5.9: Two commenters (0151, 0153) contended that batch process 

operation requirements need clarification. One commenter (0151) pointed out that, EPA requires 

that performance testing must be done at the ―absolute worst-case conditions or hypothetical 

worst-case conditions‖ [§63.11945(b) and (c)], yet EPA offers no specific example of how to 

ascertain that scenario. Another commenter (0153) noted that, as indicated in §63.11945(a), PVC 

plants operate with batch reactors and continuous strippers, so they would seem to be classified 

as a combination of batch and continuous operations. They (0153) argued that as long as the test 

is designed to incorporate the maximum load to the thermal oxidizer, other batch process 

considerations of hypothetical or actual worst case conditions should not be relevant. The 

commenter (0151) requested EPA provide specific examples to assist the regulated community 

in how the operating conditions should be established for the regulated HAPs.

Response 10.1.5.9: We believe that ―absolute worst-case conditions and hypothetical 

worst case conditions‖ are adequately explained by the requirements at 63.11945(c). Sources 

should work with their delegated authority to resolve any case by case particulars. Sources also 

have the option of testing over a range of conditions to provide operational flexibility, or can

chose to monitor the emissions using CEMs.

Comment 10.1.5.10: One commenter (0153) argued that EPA must amend §63.11945(d) 

to remove the requirement to measure organic HAP at the control device inlet, unless a percentremoval option is incorporated in the rule (a flexible and recommended approach). The 

commenter (0153) added that subsection (d) (regarding emission profile) is confusing and must 

be clarified because it addresses total organic HAP at both the control device inlet and outlet. 

According to the current proposed rule, only THC is needed at the outlet.

Response 10.1.5.10: The commenter has misinterpreted the proposed rule. The proposed 

rule citation did not require measurement of organic HAP at the control device inlet. The final 

rule also does not require measurement of organic HAP at the control device inlet. The final rule 

does require an emissions profile be established at the control device inlet; however, the 

emissions profile may be based on engineering assessment or measurements.
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10.2 Emission Limits, Operating Limits, and Work Practice Standards

Comment 10.2.1: One commenter (0157) argued that EPA should revise the process vent 

limit from all types of processes to be controlled to 12 ppm total HAP, consistent with the PVC 

MACT Table 1. They (0157) argued that the change in language from ―vinyl chloride‖ to ―HAP‖ 

in the §61.65(b)(3) requirements adopted to the proposed rule constitutes a 10 ppm HAP limit 

that lacks justification, and thus the limit should be revised to 12 ppm total HAP. 

Response to comment 10.2.1: We are not able to determine what the commenter is 

referring to in their comment. At proposal, the total organic HAP limit for existing sources was 

calculated to be 12 ppmv and the vinyl chloride limit was determined to be 0.32 ppmv. For the 

final rule we have revised the MACT floor limits and developed two subcategories for process 

vents based on additional data received after proposal. Our discussion of the revised MACT floor 

analysis and results is contained in section V.E of the preamble to the final PVC rules. If the 

commenter is referring to the other emission source category when emissions are routed through 

a closed vent system to a control device, those sources must comply with the outlet emission 

limit from the process vent control device. In the final rule, process vents include batch process 

vents, continuous process vents and miscellaneous process vents. Miscellaneous vent means 

gaseous emissions from samples, loading and unloading lines, slip gauges, process wastewater 

treatment systems and pressure relief devices that are routed through a closed vent system to a 

control device and that are not equipment leaks.

Comment 10.2.2: One commenter (0142) argued that samples themselves are not 

emission points and therefore cannot be process vents. The commenter (0142) stated that based 

on the proposed rule, EPA is requiring that ―samples‖ (as process vents) be connected to a closed 

vent system and control device. The commenter (0142) stated that this is impractical because 

samples are collected into containers. The commenter (0142) added that larger containers (i.e. 

drums, pails, or totes) are exempt from the definition of batch process vent. Since sample 

containers are typically much smaller than drums, pails, or totes, one would infer that sample 

containers should also be exempt from the definition of a process vent. The commenter (0142) 

concluded that if EPA intended that the process vent provisions apply to sample systems (rather 

than ―samples‖), these requirements are covered under 40 CFR 63.1032 of subpart UU as 
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referenced in the equipment leak provisions of the proposed rule and are also exempt from the 

definition of batch process vent. 

Response to comment 10.2.2: While we agree that samples are not process vents, the part 

61 rule required that samples be returned to the process and emissions controlled to meet 10 

ppmv of vinyl chloride. The final rule, we include samples as ―miscellaneous vents‖ and require 

that emissions from ―miscellaneous vents‖ be controlled to meet the applicable process vent 

emission limit.

Comment 10.2.3: One commenter (0153) stated that EPA must clarify whether the HCl 

limit requires measurement of HCl only, or whether it is meant to include hydrochloric acid and 

chlorine as measured separately by Method 26A. Some of the other MACT standards (e.g., 

Hazardous Waste MACT), require HCl results to be reported as total chloride equivalents. On 

the other hand, the commenter (0153) stated that the Portland MACT requires control of HCl 

only, since it is a reasonable indicator that any low levels of other acid gases are removed by the 

scrubbers.

Response to comment 10.2.3: In the final rule we have determined that HCl is an 

appropriate surrogate for chlorine. Therefore, Method 26A must be used to demonstrate 

compliance with the HCl emission limit but only the HCl emissions have to be reported. 

Comment 10.2.4: One commenter (0142) argued that EPA should require oxygen 

correction in the stack to 7% rather than to 3% as proposed. The commenter (0142) pointed out

that Table 1 Emission Limitation for Process Vents establishes a limitation for hydrogen chloride 

for new sources to be 0.17 ppmv. Additionally, note (b) indicates the measured emission limits 

are to be corrected to 3% O2. The commenter (0142) stated that the 0.17 ppmv level for a wet 

stack can be outside the capability of the required method (Method 26 or 26A). The commenter 

(0142) added that another point of concern is the requirement to correct and report the value to 

3% O2. The commenter (0142) stated that these facilities typically operate at O2 levels between 

6% and 10%. The commenter (0142) added that this O2 level is typically due to the process vent 

load; the higher O2 content provides improved operational reliability while feeding vents. The 

commenter (0142) stated that correcting to 3% O2 also does not compare with other standards 

dealing with the same compound (subpart EEE). The commenter (0142) suggested that the 

correction should be changed to 7% to allow consistent representation with subpart EEE. In 
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addition, the hydrogen chloride standard for new sources is set at 7%. The commenter (0142) 

added that the chlorine/hydrogen chloride standard under 40 CFR part 63 subpart EEE for 

hydrochloric acid furnaces for new sources has the level at 7% O2 (§63.1218 (a)(6)). The 

commenter (0142) recommended that the hydrogen chloride standard in Table 1 (29534) be 

consistent with 40 CFR §63.1218 and that the O2 correction standard be 7% O2

Response to comment 10.2.4: We disagree with the commenter‘s suggestion to change 

the oxygen correction from 3 to 7 percent in this rule. As the actual oxygen percent content from 

a specific source can vary, it is important to select, and then use, a consistent basis for 

comparison. The testing data that were used to calculate the emission limits were all based on an 

oxygen correction of 3 percent as required by the PVC CAA section 114 testing requirement. 

Emissions limits established in the rule were corrected on a consistent basis to 3 percent oxygen, 

and the rule retains that 3 percent oxygen correction. In addition, the commenter provided no 

data to support his claim that Method 26 or 26A may be unsuitable in certain circumstances for 

use by the rule. The final hydrogen chloride emissions limits for new and existing sources, are 

within detection limits for Method 26 and Method 26A.

10.3 MACT Floor

Comment 10.3.1: One commenter (0146) agreed with EPA that both thermal oxidizers 

with acid gas scrubbers and chemical absorbers are effective technologies for controlling organic 

HAPs, including VCM.

Response to comment 10.3.1: We thank the commenter for their comment.

Comment 10.3.2: Two commenters (0146, 0153) contended that EPA should set the THC 

limit and compliance demonstration based on non-methane hydrocarbons to ensure methane 

spikes will not impact compliance demonstrations. EPA set the THC limit based on total 

hydrocarbons, including methane. However, this method could result in non-compliance in the 

event of a natural gas spike, particularly during a cold start-up. PVC facilities submitted nonmethane data to EPA pursuant to the CAA 114 request and EPA should use that data to reset the 

THC limits.

Response to comment 10.3.2: We disagree with the commenters‘ suggestion to exclude 

methane from the total hydrocarbon (THC) emissions limit. As mentioned earlier with respect to 
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the TOHAP emissions limit, we do not believe the contribution or costs associated with 

obtaining extra data warrant excluding methane from the THC emissions limit. Moreover, we 

find the commenters‘ concern regarding methane spikes during start-ups to be moot, since THC 

emissions testing will not occur during startup periods. Finally, we got neither sufficient nonmethane data submitted by facilities to calculate emission limits, nor sufficient THC speciation 

data from each facility in order to determine a non-methane THC emissions limit. As a result, the 

final rule maintains a THC, not a non-methane THC, limit.

11.0 RESIN

Comment 11.1: One commenter (0139) argued that data from the Henry, Illinois source 

should be included in setting the dispersion MACT floor limit. As a part of its comments, the 

commenter (0139) removed non-detected analytes known not to be in the process, making the 

data comparable, and thus argued that these data should be considered within the dispersion floor 

limit data set. 

Response to comment 11.1: For the final rule, we have evaluated the additional and 

revised data submitted by the Vinyl Institute and PolyOne and have included the appropriate data 

from the PolyOne facilities into the respective data sets for both dispersion and suspension 

blending resins. See also section V.E.2 of the preamble for the final rule. 

Comment 11.2: One commenter (0146) argued that material substitution is not a viable 

non-technological factor for setting floors for resin stripping.

Response to comment 11.2: In the final rules, we are not requiring material substitution 

as a control technology to meet the emission limits, though sources may choose to comply 

through material substitution at their discretion. 

Comment 11.3: One commenter (0118) supported using data collected using EPA 

Method 107 to set the MACT floors rather than Method 8260B. The commenter (0118) stated 

that a benefit of using a larger data set containing individual strippers and reactors for stripper 

samples is related to startup and shutdown. The commenter (0118) stated that it is possible that 

when either starting up or shutting down a daily composite could be comprised of only a single 

sample. The commenter (0118) contended that data show a limit based solely on daily 
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composites would underestimate the true variance associated with individual samples. The 

commenter (0118) concluded that this underestimation would lead to a limit that may be 

unattainable during startup and shutdown events.

Response to comment 11.3: We have revised our MACT floor variability analysis based 

on data submitted by the industry after the rule proposal to incorporate the larger dataset using 

results from EPA Method 107 testing. See section V.E. 2 of the preamble to the final rules where 

we discuss the data sets used to develop the final stripped resin limits.

12.0 STORAGE VESSELS

Comment 12.1: One commenter (0011) addressed EPA‘s conclusion that because PVC 

manufacturers all fall below established regulations for storage vessels, this will be the standard 

for PVC manufacturers. The commenter (0011) contended that this stance essentially exempts 

PVC manufacturers from the kinds of protections for storage facilities that deal with sealing 

mechanisms, floating roofs, and routing streams to a controlled device that could reduce volatile 

organic emissions by 95 percent.

Response to comment 12.1: We disagree with the commenter. In addition to a MACT 

floor analysis for storage vessels, we evaluated a beyond the floor option of complying with 

storage vessel requirements equivalent to existing storage vessel regulations, primarily subpart 

Kb. Based on this evaluation, we determined it was appropriate to require control and 

compliance of storage vessels meeting the subpart Kb size and vapor pressure thresholds. 

However, meeting more stringent control levels was not cost-effective. Data that were collected 

for development of the PVC standards shows that this source category does not use storage 

vessels above the vapor pressure and size thresholds of the final rule. We are requiring that all 

other storage vessels meet the operating, inspection and maintenance requirements for fixed roof 

vessels or comply with either the controlled fixed roof or floating roof requirements as discussed

in the preamble to the final PVC rules.

Comment 12.2: One commenter (0142) argued that recordkeeping on degassing and 

cleaning events should not be necessary if work practices are in place. The commenter (0142)

contended that degassing and cleaning operations occur on a routine and non-routine basis, and 
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thus maintaining a record of all of these activities would present an unreasonable burden. 

Therefore, the commenter (0142) proposed that EPA delete requirements for recordkeeping and 

emissions estimations on every degassing and cleaning event, and instead control emissions 

during these events with work practice requirements.

Response to comment 12.2: We agree with the commenter regarding the proposed 

recordkeeping requirements for degassing. We have removed this requirement from the final 

rule.

Comment 12.3: Two commenters (0157, 0134) expressed concern with EPA‘s 

classification of a ―leak‖ from a pressure vessel closure device as a violation of the rule. They 

requested clarification why leaks from this source were singled out in contrast to leaks from 

other devices, and argued that instead all leaks should be subject to the same leak detection and 

repair (LDAR) requirements. One commenter (0134) contended that the Court previously held, 

regarding leaks of vinyl chloride from equipment, ―...fugitive, or unintended releases of VC will 

occur. Such episodic, pre-exhaust-phase discharges are not illegal provided that certain workpractice standards are complied with to minimize such occurrences.‖[U.S. v. Conoco, No. 83-

2518 (W.D. La. June 1, 1984)], and thus the use of area monitoring systems for vinyl chloride 

and subsequent application of LDAR procedures constitute acceptable work-practice standards. 

One commenter (0134) argued that the agency should modify §63.11910(c)(3) and (4) and 

remove the special reporting requirement understanding that minor releases are not deviations of 

the operation.

Response to comment 12.3: We disagree with the commenters regarding EPA‘s 

classification of a leak from a pressure vessel as a violation of the rule. A pressure vessel is 

defined as ―a vessel that is used to store liquids or gases and is designed not to vent to the 

atmosphere as a result of compression of the vapor headspace in the pressure vessel during 

filling of the pressure vessel to its design capacity.‖ Since pressure vessels are defined to not 

vent to the atmosphere, this inherently makes them different from other storage vessels, such as 

fixed roof storage vessels that are designed to vent with diurnal temperature changes. We believe 

that because pressure vessels are designed to not vent to the atmosphere and with no detectable 

emissions, a leak (i.e., above 500 ppm background) from one would be inconsistent with the 

definition of a pressure vessel, and hence a violation of the rule.
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Comment 12.4: Two commenters (0153, 0142) argued against the prohibition of all 

detectable emissions from pressure vessels in all circumstances. One commenter (0142) argued 

that it is unreasonable to prevent the adjustment for background concentration, and that Section 

3.4 of Method 21 includes an adjustment for ambient concentrations of VOCs. This commenter 

(0142) argued that if background concentrations are not taken into consideration when defining a 

leak, a source may be considered in violation and required to make unnecessary repairs to a 

pressure vessel in response to a ―leak‖ that does not exist. They (0142) stated that if work 

practices are to be required for pressure vessels and monitoring of ―leak interfaces‖, EPA should 

clearly define what a ―leak interface‖ means and also should clearly define a reasonable leak 

threshold that takes background concentrations of VOC/HAP into consideration. Both 

commenters (0153, 0142) requested clarification of the term ―leak interface.‖ The commenters 

(0153, 0142) state that equipment is already regulated under the equipment leak provisions of the 

rule (i.e. pumps, valves, connectors, etc.), and thus clarification is needed as to what EPA 

considers a ―leak interface‖. The commenter (0142) recommended using the previously 

established ―no detectable emission‖ level of 500 ppm above background for this leak definition. 

One commenter (0153) argued that leaks are monitored under LDAR program and are not 

deemed automatic violations, and thus such leaks should not be considered deviations unless 

specific requirements of the LDAR program have not been followed. They (0153) also argued 

that the use of the affirmative defense criteria should be an available option. One commenter 

(0153) disagreed with the proposed rule‘s inclusion of pressure vessels storing gases, liquids, or 

gases and liquids as a category of tanks to be regulated. The commenter (0153) argued that other 

MACT standards provide exemptions for ―Pressure vessels designed to operate in excess of 

204.9 kilopascals and without emissions to the atmosphere‖. The commenter (0153) contended 

that since these vessels are already regulated by other rules, the current exemption for pressure 

vessels in other MACT rules should also be used in this rule. The commenter (0153) argued that 

pressure vessels are already regulated by OSHA and EPA‘s Risk Management Mechanical 

Integrity Program and the ACC Responsible Care Management Systems requiring inspections of 

VCM storage sphere performed per API standards as well as company inspection procedures. 

The commenter requested explanation of the perceived need and required scope of the rule 

before adding what they argue is a duplicative requirement. One commenter (0146) argued that 

other MACT standards such as HON, MON, and OLD have exempted pressure vessels from the 

definition of storage vessels, and thus they contended that the agency should do likewise for this 
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proposed rule. The commenter (0146) further argued that the requirements for leak interface 

monitoring on pressure vessels are excessive and provide no definition of leak interface. Thus, 

the commenter (0146) requested that EPA delete section 63.11910(c)(4) and clarify the required 

monitoring frequencies if the agency retains section 63.11910(c)(3). The commenter (0146) 

requested EPA rely on the requirements of the proposed section 63.11915 to address equipment 

leaks from components on storage vessels. At a minimum, the commenter (0146) requested EPA 

to provide a definition of ―potential leak interfaces‖ or similar guidance as the term is not 

defined. In addition, he requested that EPA clarify the required monitoring frequencies if the 

agency retains section 63.11910(c)(3).

Response to comment 12.4: We agree with the commenters regarding adjusting for 

background concentration when identifying pressure vessels that are leaking and this allowance 

is provided in the final rule. In the final rule we have defined pressure vessels as vessels that are 

used to store liquids or gases and are designed not to vent to the atmosphere as a result of 

compression of the vapor headspace in the pressure vessel during filling of the pressure vessel to 

its design capacity. When the vessel is not being filled, it must be operated in such a manner that 

there are no detectable emissions which means the calculated value should be compared to the 

performance standard (i.e. 500 ppm above background), not a leak definition. The no detectable 

emission requirements are described in 40 CFR 63, subpart UU. Therefore, any detectable 

emissions from a pressure vessel are a deviation. The term ―leak interface‖ is not defined in this 

subpart, but is as described in Method 21 at 40 CFR part 60, appendix A-7. EPA Method 21 

requires that during a leak survey the probe inlet of monitoring instrument must be placed at the 

surface of the component interface where leakage could occur. In Section 8.3 of Method 21, the 

appropriate interface to be probed for leaks is described for each component type. A potential 

leak interface is a location where organic vapor leakage could occur. Potential leak interfaces 

that are associated with covers and closure devices include, but are not limited to, the interface of 

the cover and its foundation mounting; the periphery of any opening on the cover and its 

associated closure device; and the sealing seat interface on a spring-loaded pressure-relief valve.

We disagree with the commenter that pressure vessels should be exempted from this rule. 

While some other MACT standards exempt pressure vessels from regulation, precedent for 

regulating pressure vessels exists in 40 CFR part 63, subpart DD (National Emission Standards 

for Hazardous Air Pollutants from Off-Site Waste and Recovery Operations). The pressure 
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vessel requirements in the Off-Site Waste and Recovery Operations rule are consistent with 

those we are finalizing in the PVC rule.

We disagree with the commenter that section 63.11910(c)(3) should be deleted. We 

believe that it is appropriate and necessary to monitor leak interfaces on pressure vessels in order 

to ensure that they are in compliance with the final rule. However, we do agree with the 

commenter that section 63.11910(c)(4) should be revised, as it is unnecessary to submit a 

separate report for leaks from pressure vessels. We are instead requiring that a release from a 

pressure vessel be reported in the deviation report. 

Comment 12.5: One commenter (0157) argued that the requirement to install and 

maintain a fixed roof (including conservation vent) on any storage vessel with a capacity greater 

than 10,040 gallons without regards to the vapor pressure of the HAP stored, is excessive. 

Instead, the commenter (0157) argued that a total HAP vapor pressure upper limit should be 

established before a fixed roof with conservation vent is required; as other MACT standards have 

cut-off limits established that would account for the vapor pressure of the HAP prior to the 

installation of controls outside a fixed roof.

Response to comment 12.5: We disagree with the commenter that a HAP vapor pressure 

limit should be established before a fixed roof with conservation vent is required. Recent court 

rulings have required EPA to set standards under section 112(d) for all sources of HAP 

emissions at major source facilities. As we have set more stringent requirements for larger 

capacity storage vessels with higher HAP vapor pressures (e.g., install floating roof, route 

emissions to a control device), standards are also required for the smaller capacity storage 

vessels with lower HAP vapor pressures. We believe that most, if not all, storage vessels with a 

capacity of at least 10,040 gallons should already have a fixed roof with conservation vent 

installed; therefore, there should be very little burden associated with the requirement, and we 

believe it is appropriate in order to meet our obligation to set standards for all storage vessels.

Comment 12.6: One commenter (0153) supported the use of HON storage capacity and 

vapor pressure cutoffs proposed by the agency, which they believed will facilitate the ultimate 

integration with the co-located EDV/VCM/PVC plants and other facilities regulated by the 

HON.
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Response to comment 12.6: We thank the commenter for his support. The storage 

capacity and vapor pressure cut-offs are based on 40 CFR part 60 subpart Kb requirements.

Comment 12.7: One commenter (0153) supported the provision in section 

63.11910(a)(2)(ii)(B) allowing for conservation vents for fixed roof tanks, which they believed is 

necessary for the safe operation of tanks.

Response 12.7: We thank the commenter for their support.

Comment 12.8: One commenter (0153) supported the provision allowing operators of 

pressure vessels to vary from the annual inspection frequency for valid safety reasons, as 

specified in section 63.11910(a)(2)(B)(3).

Response to comment 12.8: We thank the commenter for their support.

Comment 12.9: Two commenters (0142, 0146) argued that vapor balancing should be an 

allowed method of control for compliance with storage tanks provisions. They (0142, 0146) 

contended that because EPA has allowed vapor balancing as a control option for storage tanks in 

other MACT rules, EPA should also allow for this technology in the proposed PVC MACT rule. 

Two commenters (0142, 0146) recommended language to be incorporated into the final 

rule to allow vapor balancing. 

Response to comment 12.9: We agree with the commenters that vapor balancing has been 

used in other MACT rules. However, we do not have data on the appropriateness of using vapor 

balancing on storage vessels in this source category. A facility can request the Administrator to 

use vapor balancing as an alternative means of emission limitation under 63.6(g) of the part 63 

General Provisions.

Comment 12.10: One commenter (0142) requested that the PVC MACT allow for design 

evaluations in lieu of performance testing for storage tank control devices and for small control 

devices. The commenter (0142) argued that language should be added to allow the use of a 

design evaluation in lieu of performance testing, as this would be consistent with other part 63 

NESHAP.

Response to comment 12.10: We agree with the commenter that design evaluations 

should be allowed for storage tank control devices and have added this option to the final rule.
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Comment 12.11: One commenter (0142) supported EPA‘s proposed 95% requirements 

for closed vent systems going to a control device, stating that it is consistent with subpart Kb 

requirements for fixed roof tanks sent to a control device.

Response to comment 12.11: We thank the commenter for their support.

Comment 12.12: One commenter (0142) argued that installation of closure devices that 

secure on fixed roof storage tanks and on pressure vessels should not be required. The 

commenter (0142) agreed that closures on storage tanks and pressure vessels should be 

maintained in the closed position when access to the vessel is not needed, but they pointed out 

that the requirements to install ―closure devices that secure‖ is unreasonable and not required by 

other part 63 NESHAP nor NSPS Kb. The commenter (0142) argued that the cost to install 

closure devices on fixed roof storage tanks and pressure vessels was not evaluated as part of the 

MACT floor, and therefore, EPA should remove this requirement from the proposed rule.

Response to comment 12.12: We believe that the commenter has misinterpreted the term 

―secure‖ to mean that the closure device must have a latch, bolt, or other device to secure it in 

the closed position; this is not the intention of the language. By using the term ―secure,‖ we 

mean that if there is a latch, bolt, or other device to secure the closure device in the closed 

position, it must be secured such that there are no visible cracks, holes, gaps, or other open 

spaces between the perimeter of the opening and the closure device. Additionally, precedent for 

using this language exists in 40 CFR part 63, subpart OO (―National Emission Standards for 

Tanks—Level 1‖), which says in §63.902(b)(3)(i): ―[Each opening in the fixed roof, and any 

manifold system associated with the fixed roof, shall be] equipped with a closure device 

designed to operate such that when the closure device is secured in the closed position there are 

no visible cracks, holes, gaps, or other open spaces in the closure device or between the 

perimeter of the opening and the closure device.‖

Comment 12.13: One commenter (0142) requested that EPA include provisions to allow 

for maintenance down time for control equipment for which storage vessels are vented. The

commenter (0142) argued that most control equipment requires periodic maintenance and during 

these times, it is not practical to empty all regulated storage vessels of material. The commenter 

(0142) pointed out that most part 63 NESHAP have provisions to allow 240 hours of 
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maintenance downtime, during which the emission limits specified in the rule would not have to 

be met. The commenter (0142) requested that EPA include similar provisions in the PVC 

MACT. 

Response to comment 12.13: We agree with the commenter that an allotment of 240 

hours should be provided for maintenance down time for control equipment to which storage 

vessel are vented because the emissions generated from a storage vessel cannot be ―shutdown‖ to 

conduct control device maintenance, unless the tank is emptied and degassed. Emptying and 

degassing the tank can create more emissions than idling the tank while making the control 

device repairs. For these reasons, we have allowed this in other NESHAP standards (e.g., 40 

CFR part 63, subpart G). We have added this provision to the final rule.

Comment 12.14: One commenter (0142) requested clarification on the storage vessel 

requirements, asking that it be clearly stated that these requirements only apply to storage vessels 

in Hazardous Air Pollutant (HAP) service and not to storage vessels containing non-HAP 

materials. The commenter (0142) argued that since the pollutants of concern for this regulation 

are the HAP constituents, EPA should clarify that the only regulated storage vessels at the 

affected source are those in HAP service.

Response to comment 12.14: We agree with the commenter and have clarified in the final 

rule that the storage vessel provisions only apply to vessels in HAP service. The PVC MACT 

standards generally are applicable to sources that emit HAP or are in HAP service.

Comment 12.15: One commenter (0142) argued that the current fixed roof tank 

inspection and repair requirements are inconsistent with other part 63 NESHAP and should be 

deleted from this proposed rule. The commenter (0142) also contended that there was no basis 

for EPA choosing the 5 day repair requirement, and that the 45 day repair requirement is based 

on floating roof tank requirements in 40 CFR 63.1063(e) of subpart WW rather than fixed roof 

requirements. The commenter (0142) argued that requirements for floating roof tanks should not 

be applied to fixed roof tanks.

Response to comment 12.15: We agree with the commenter that the 5 day repair 

requirement is not appropriate, and it has been removed from the final rule. However, we 

disagree with the commenter that the 45 day repair requirement is not appropriate. We believe 
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that both floating roof and fixed roof tanks should be placed on the same repair schedule and that 

45 days is an appropriate period of time to ensure that the leaking tanks are repaired.

13.0 WASTEWATER

13.1 Compliance and Monitoring

13.1.1 Relaxed testing for wastewater streams

Comment 13.1.1.1: One commenter (0134) proposed that language be added to 40 CFR 

63.11975(d) and (e) indicating that if three consecutive monthly samples show levels of VCM or 

total HAP below 30% of the threshold then follow-up sampling be required once every three 

years. Another commenter (0153) proposed that streams found to be stable with less than 1,000 

mg/l of HAP should not have to be re-sampled each month. Three commenters (0142, 0144, 

0146) said monthly sampling would be costly, time-consuming, and place an unnecessary burden 

on both affected sources and the regulators. One commenter (0144) argues that sampling 

frequency should be reduced because a well designed test plan can capture the variety of 

facilities product formulations and sample the worst case wastewater. One commenter (0157) 

suggested that monthly sampling be extended to quarterly. Another commenter (0146) suggested 

that vinyl chloride and total organic HAP sampling frequency should be no more than once every 

five (5) years. An initial demonstration of total organic HAP at streams that need treatment is 

justified because organic HAP is not regulated under the current vinyl chloride NESHAP.

A commenter (0134) also requested that EPA add language to 40 CFR 63.11975(e)(2) to 

allow low flow rate streams, less than 10 liters per minute, to permanently abstain from both total 

HAPs sampling and re-establishment of flow rates absent a process change. Stream flow rates 

are fixed by design and have little variation. 

Two commenters (0146, 0153) supported the link to HON wastewater requirements: 

The 1,000 ppm total HAP cutoff is already in use in plants that are regulated by the HON. 

40 CFR 63.11965(a) requires an initial determination based on the Table 9 of the HON 

(subpart G). Table 9 of the HON has many analytes (74 in all), most of which will NOT 

be present in PVC plant wastewater. 
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The proposed MACT rule uses the HAP list from the Table 9 of the HON (subpart G) 

except for formaldehyde. One commenter (0146) recommends that formaldehyde be 

added to the PVC process HAP list to be analyzed as part of total organic HAP for both 

stripped resin and wastewater, as it was detected and reported by several PVCPUs during 

the section 114 30-day testing that took place in late 2009, and early 2010. 

Commenter (0146) provided the following language suggestion for §63.11980(b), 

footnote for variable ―Ci‖: ―Concentration of each individually identified HAP, in ppmw, where 

a value of zero should be used for any HAP concentration that is below the detection limit.‖ This 

revision is necessary, because Table 9 does not include formaldehyde, and because many PVC 

process specific HAPs, included in Table 9, may not be present in wastewater.

One commenter (0134) argued wastewater stripper outlet concentration limits are not 

appropriate, but work practice standards will effectively minimize HAP emissions. The 

commenter also proposed that EPA allow for a reduced sampling frequency for low flow and/or 

low concentration wastewater streams.

Response to comment 13.1.1.1: With respect to the comments related to the HON 

requirements and the sampling frequencies, we have removed the HON-related requirements 

from the final rule and revised the limits and requirements for process wastewater. We agree 

with the commenter that an initial determination for streams that require treatment is necessary. 

We also recognize that stream flow rates are fixed by design and have little variation. Therefore, 

for streams that do not require treatment, follow-up performance testing is required at least 

annually. However, monthly sampling and analysis for streams that require treatment is 

necessary to maintain continuous compliance with the process wastewater limits. We disagree 

that low flow rate streams, less than 10 liters per minute, should permanently abstain from 

sampling. While we have removed the requirement to establish flow rate for the purposes of 

compliance, if it is demonstrated that a stream is below the limits for process wastewater, 

regardless of flow rate, then that stream does not require treatment and must be resampled 

annually.

For the final rule, we calculated MACT limits for total non-vinyl chloride organic HAP 

and vinyl chloride separately. Based on our evaluation of the total non-vinyl chloride organic 

HAP limits, we determined that the 1,000 ppmw threshold for total organic HAP, above which 

facilities would have been required to comply with the HON wastewater provisions, was not 

appropriate for the final rule as all streams must meet a limit for total non-vinyl chloride organic 
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HAP that is much lower than the proposed 1,000 ppmw threshold. See section V.E.2 of the 

preamble to the final rules for additional discussion.

We have revised Equation 1 in section 63.11980(b) to clarify that a value of zero should 

be used for any HAP concentration that is below the detection limit. We have also limited the 

specific HAP that must be analyzed in process wastewater samples to a subset of HAP listed in 

Table 10 to the final rule. The Table 10 HAP are the same for both stripped resin and process 

wastewater, and represent those HAP which data indicate are, or may be, present in process 

wastewater streams from the PVC industry. See the related discussion and rationale for stripped 

resins. Table 10 includes formaldehyde which is not included in Table 9 of the HON. 

We disagree with the commenter‘s assertions that wastewater stripper outlet 

concentration limits are not appropriate and that work practice standards will effectively 

minimize HAP emissions. No data were provided to support the claim that outlet stripper limits 

are not effective or appropriate.

Comment 13.1.1.2: Four commenters (0142, 0146, 0153, 0157) argued that wastewater 

streams can vary depending on process condition and any grab sample represents only a point in 

time. The commenters (0142, 0146, 0153, 0157) stated that there are no averaging provisions for 

concentration, which is unlike other CAA wastewater-related requirements which have annual 

average concentration determination provisions (see HON §§63.132(c) and 63.144(b), and 

BWON §61.355(c)). In addition, the commenters (0142, 0146, 0153, 0157) stated that there is no 

annual average flow rate for determining if streams must be controlled. The commenters (0142, 

0146, 0153, 0157) suggested that the PVC MACT should have the same threshold of 10 l/min as 

allowed for the HON Table 9 total organic HAP determination and allow an annual average 

concentration. 

Response to comment 13.1.1.2: We have removed the HON-related requirements for 

process wastewater in the final rule. See previous responses to comments and associated sections 

of the preamble to the final rule for more details. In the final rule, wastewater samples must be 

taken once per month to demonstrate compliance with the total non-vinyl chloride organic HAP 

wastewater emission limit.

Comment 13.1.1.3: Two commenters (0146, 0157) argued that wastewater stream 

variability presents a challenge to facilities that are required to construct new WW strippers or 
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other control devices to comply with new limits. The commenters (0146, 0157) contended that 

PVCPUs should be allowed to gather WW stripper VC data for the year prior to the initial 

demonstration of compliance so that the first month of continuous compliance can be calculated 

as a 12 month rolling average as set forth in section 63.11975(a)(3)(iii).

Response to comment 13.1.1.3: We have removed the 12-month rolling averaging 

provision from the final rule requirements for wastewater. Continuous compliance with the 

process wastewater limits must be met on a monthly basis as the revised MACT floor variability 

analysis was conducted for monthly compliance.

13.1.2 Point of determination (POD) / Intermittent wastewater

Comment 13.1.2.1: One commenter (0146) asked that EPA remove the word  ̳directly‘ in 

any wastewater language. The commenter (0146) stated that in section 63.11965(b)(1), the 

statement ―Route wastewater streams through hard piping from the point of generation directly 

to the treatment process....‖ includes the word  ̳directly,‘ which could be misinterpreted to 

exclude intermediate vessels such as a wastewater stripped feed tank. The commenter (0146) 

added that in accordance to the part 61 NESHAP, wastewater collection systems that have a 

vinyl chloride concentration greater than 10 ppm can include collection vessels such that 

wastewater may not go  ̳directly‘ to the treatment process, and such intermediate vessels are 

either pressure vessels or are vented to the closed vent system.

Response to comment 13.1.2.1: We agree with the commenter that the final rule 

requirements need to be clarified to avoid confusion and unintended application of the standards. 

The word ―directly‖ and related language have been removed from the final rule requirements 

for process wastewater.

13.1.3 Rule Clarifications Requested

Comment 13.1.3.1: Three commenters (0144, 0146, 0153) requested a provision for 

calculating total organic HAP when the concentration of an individual pollutant, using approved 

methods of analysis, is non-detect. Is it appropriate to use zero for non-detects in the summation? 
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Response to comment 13.1.3.1: In the final rule, we have clarified that for the calculation 

of total non-vinyl chloride organic HAP, any result for an individual HAP that is below the 

detection limit, or a non-detect, is to be assigned a value of zero.

Comment 13.1.3.2: One commenter (0153) requested that EPA explain why biological 

wastewater treatment equipment is being incorporated into the PVCPU because no explanation is 

currently provided in the preamble or is known to the industry.

Response to comment 13.1.3.2: The final rule contains no specific requirement for 

sources to use biological treatment.

Comment 13.1.3.3: One commenter (0134) asserted that in 40 CFR 63.11975(e)(3) ―vinyl 

chloride‖ was mistakenly used in the place of ―total HAP.‖ 

Response to comment 13.1.3.3: We agree with the commenter. Section 63.11975 has 

been revised in the final rule.

Comment 13.1.3.4: One commenter (0157) argued that the total HAP control 

requirements (testing, sampling, etc.) should be removed from the wastewater rule because in the 

preamble, Section "V. Impacts of the Proposed PVC Rule," the value of total HAP removed is 

equal to the reduction in VC, 0.4 tpy. Therefore, the commenter (0157) concluded, the total HAP 

control requirements result in no reduction in VC.

Response to comment 13.1.3.4: We disagree with the commenter regarding the proposed 

rule. At proposal, we included a total HAP limit, and because vinyl chloride is a HAP, it was 

included in determination of the total HAP limit. In the final rule we have revised the MACT 

floor limits for process wastewater to specify concentration limits for total non-vinyl chloride 

organic HAP and vinyl chloride separately. The changes are discussed in section V.E.2 of the 

preamble to the final rules.

Comment 13.1.3.5: Two commenters (0142, 0146) recommended that the language of 40 

CFR 63.11975(e)(3) be changed. The commenters (0142, 0146) added that the proposed rule 

requires that if monthly performance tests show total HAP greater than or equal to 1,000 ppm 

(by weight) and the annual average flow rate is greater than or equal to 10 liters per minute, then 

you must use a treatment process to reduce the vinyl chloride as specified in 40 CFR 63.11965(c) 
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and you must demonstrate compliance as specified in 40 CFR 63.11975(b). The commenter 

(0142, 0146) added that the beginning of section 63.11975(e)(3) addresses the concentration of 

total HAP. However, the commenters (0142, 0146) added that treatment process focuses on 

reducing the vinyl chloride concentration. The commenters (0142, 0146) proposed changing the 

language to ―then you must use a treatment process to reduce the total HAP concentration as 

specified in....‖

One commenter (0146) requested clarification of 40 CFR 63.11965(d). Under section 

63.11965(d)(1), the total annual wastewater volume of all streams within the PVCPU must be 

under 1.4 million gallons over a designated 12-month period and have a total annual HAP 

concentration under 1,000 ppmw in order to be exempt from control and treatment requirements. 

The commenter (0146) explained that if, for example, within a 12-month period, a PVCPU 

generated a 1,500 ppm HAP in-process wastewater stream that flowed at 100 l/min for 60 min, 

the stream would not be subject to control and treatment since the annual average flow rate is 

less than 1,600 gal/yr, which is less than 1.4M gal/yr. The commenter (0146) added that this 

exercise would be repeated for other wastewater streams that are generated or are anticipated to 

be generated over a year, and then totaled for the Unit. The commenter (0146) concluded that as 

long as the unit has generated less than 1.4 M gallons of low flow rate streams in a year, these 

low flow rate streams do not require control and treatment.

Response to comment 13.1.3.5: In the final rule, we determined the MACT floor level of 

control for wastewater to include concentration limits for total non-vinyl chloride organic HAP. 

In the final rule we are no longer requiring control of streams above a specified flowrate. The 

changes are discussed in section V.E.2 of the preamble to the final rules.

13.1.4 Sampling/Analysis Methods

Comment 13.1.4.1: Two commenters (0146, 0153) asked that wastewater sample holding 

times be changed. Through the operation of 40 CFR 63.11980(a)(2)(i) [and 63.11960(d)(2)(i)] 

EPA would force the adoption of a section of Method 107 that requires the analysis of samples 

for total organic HAPs within 24 hours of collection. 

One commenter (0146) argued that the 24-hour holding time in Method 107 will preclude 

PVCPUs from utilizing commercial outside laboratories for TOHAP samples, over-riding the 

normal holding times established in each analytical method, and the guidance provided by SW-
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846. The commenter (0146) stated that the 24-hour holding time will require that each PVCPU 

purchase equipment and hire skilled laboratory staff to set up Methods 8260, 8270, 8315, and 

8015. The commenter (0146) added that since these methods require purchase of gas 

chromatographs, mass spectrometer detectors, and a liquid chromatograph (for Method 8315), as 

well as substantial associated extraction equipment, the capital cost per PVCPU will be large.

Another commenter (0153) stated that he believes that holding time requirements should 

be: 1) specific to the methods to be used, 2) consistent with guidance in SW-846, or 3) the result 

of specific holding time studies that demonstrate HAP concentration stability. One commenter 

(0146) argued that each PVCPU should have the ability to determine how best to minimize the 

loss of HAP, maintain sample integrity, and determine what appropriate sample preservation and 

holding times are required. That same commenter (0146) provided the following language 

suggestion for §63.11980(a)(3): ―For measuring vinyl chloride, you must use Method 107 at 40 

CFR part 61, hereby incorporated into part 63 as an Appendix. Existing EPA approved 

modifications to Method 107, obtained for use at PVCPUs, continue to be authorized for analysis 

of vinyl chloride in stripped resin and wastewater.‖ The commenter (0146) noted that EPA will 

supersede 40 CFR part 61 with the new MACT for PVC and copolymers, therefore Method 107 

(and other relevant parts of part 61) will need to be moved into part 63.

Response to comment 13.1.4.1: The comments are moot since the final rule requires daily 

vinyl chloride sampling using EPA Method 107 and monthly total non-vinyl chloride organic 

HAP sampling using EPA Method SW-846-8260B along with the other methods specified in 

Table 10 of the final rule. We disagree with the commenter regarding moving sampling methods 

in part 61 to part 63. EPA Method 107 in part 61 is not part of the vinyl chloride NESHAP but is 

in Appendix B of part 61; therefore, there is no reason to move them if the requirements of the 

part 61 vinyl chloride NESHAP no longer apply.

Comment 13.1.4.2: Two commenters (0140, 0146) took issue with Method 305. One 

commenter (0140) recommended that Method 8015 be required for the determination of 

methanol in wastewater rather than Method 305. One commenter (0140) stated that Method 305 

uses polyethylene glycol (PEG) as an extracting solvent, which is a poor solvent for water 

soluble, highly polar organics such as methanol. The commenter (0140) added it employs 

recovery correction factors based on spiked QC sample recovery, a technique that has 

traditionally been avoided for environmental chemistry measurements. The commenter (0140) 
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argues that the current process for method selection is confusing. EPA should minimize the 

number of methods employed and present a selection table in the final that is parameter, method 

and matrix specific. 

One commenter (0146) recommended replacement of Method 305 with SW-846 Method 

8015. The commenter (0146) also recommended that, in addition to SW-846 Method 8260B, 

Method 305, Sections 6.0 and 7.0 (for methanol only) and EPA Method 107, other SW-846 

methods be added to ensure analysis of all potential PVC process-related HAPs, specifically: 1) 

Method 8260B for volatile organic compounds; 2) Method 8270C for semi-volatile compounds; 

3) Method 8315A for aldehydes, specifically acetaldehyde and formaldehyde; 4) Method 8015C 

for alcohols, specifically methanol; and 5) EPA Method 107 for VCM. All five (5) of these 

methods should be listed in 40 CFR 63.11980(a)(2).

Response to comment 13.1.4.2: We agree with the commenters, and the final rule now 

requires use of EPA Method 107 for vinyl chloride and, for total non-vinyl chloride organic

HAP, use of EPA Methods SW-846-8260B for volatile organic compounds, SW-846-8270D for 

semi volatile organic compounds, SW-846-8351A for aldehydes, and SW-846-8015C for 

alcohols.

13.1.5 General

Comment 13.1.5.1: Three commenters (0142, 0143, 0146) asked EPA to omit the sitespecific test plan review for initial testing and subsequent monthly sampling. The commenters 

(0142, 0143, 0146) contended that there is nothing ―special‖ about the sampling requirements 

that would uniquely require review and approval of a test plan. The commenters (0142, 0143, 

0146) added that other MACT standards appropriately recognize that there is no need to make 

each facility incur the cost and delay of writing up a formal test plan, and then getting an agency 

to approve the plan, before going out to do sampling. EPA could review test plans after they 

have been implemented given that the industrial category includes a small number of PVC and 

copolymers production facilities. The commenters (0142, 0143, 0146) added that the potential 

for civil penalties provides an ample incentive to make sure the data are valid. One commenter 

(0153) requested clarification that the sampling and analysis plan (SAP) cover both stripped 

resin and wastewater, be submitted once with the Notification Of Compliance Status (NOCS), 

and that the plan be available for agency inspections at the PVC site. 
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Response to comment 13.1.5.1: We disagree with the commenters‘ suggestion to do away 

with site specific evaluation test plan review. Just as in other plan development, source owners or 

operators benefit from having to put down on paper how their emissions testing will be 

performed, leading to informed staff and reduced emissions. Note that while the final rule 

requires submission of the test plan to the Administrator for approval when CEMS are used; 

however, submission of the test plan to the Administrator for approval when CPMS are used is 

required only when requested by the Administrator. We believe the requirements of 

§63.11990(a) to keep copies of the test plans as records will ensure the plans are available for 

agency inspections.

Comment 13.1.5.2: One commenter (0146) requested clarification about several sections 

of the MACT general conditions cited in 40 CFR 63.11980(a)(2): 

Section 63.7(c)(3) is entitled ―Approval of site-specific test plan‖ and only addresses 

EPA disapproval of site-specific test plans, including the provision that EPA failure to 

approve a test plan does not relieve the owner or operator from legal responsibility for 

compliance. 

Section 63.7(e)(2)(i) is cited, which subparagraph appears to only address EPA approval 

of minor changes to a test method. Sections 63.8(d) and (e) are also cited as required 

provisions for submitting the test plan for approval, but these citations are specifically for 

continuous monitoring systems (―CMS‖) and appear to be inapplicable for a site-specific 

wastewater test plan.

Response to comment 13.1.5.2: The comments are moot, as the test methods for 

wastewater in the rule no longer contain references to §63.7(c)(3) or §63.7(e)(2)(i).

Comment 13.1.5.3: One commenter (PH-BR-0011) argued EPA‘s threshold for triggering 

vinyl chloride reductions is above the capacity of any PVC manufacturer. The commenter (PHBR-0011) added that the result is that all existing manufacturers are exempt from wastewater 

stream reductions. 

Response to comment 13.1.5.3: We are not able to determine what the commenter is 

referencing. The rule has a limit that applies to wastewater regardless of capacity. The 

wastewater emission limit will require reduction of vinyl chloride and total non-vinyl chloride 

organic HAP emissions. 
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Comment 13.1.5.4: One commenter (0144) noted the proposed rule does not contain any 

requirements related to maintenance, shutdown or turnaround for wastewater. The commenter 

(0144) stated that some of the earlier promulgated process industry MACT standards such as the 

HON and the MON contain specific provisions addressing management and control of 

maintenance wastewater streams containing HAP at the point of determination. The commenter 

(0144) requested that EPA consider these maintenance, startup, and shutdown activities and 

provide appropriate provisions in the rule to address related emissions from these streams.

Response to comment 13.1.5.4: Separate requirements for maintenance wastewater have 

been added to the final rule. We are requiring that facilities comply with the HON work practices 

for maintenance wastewater. See discussion in Preamble Section V.F.4. Our discussion of startup 

and shutdown are in section 24 of this document.

13.2 MACT Floor

Comment 13.2.1: One commenter (0146) stated that EPA proposed two different 

compliance periods for total organic HAP (TOHAP); 1) the first 12 month period following 

demonstration of initial compliance, and 2) all subsequent months. The commenter (0146) also 

argued that in order to use the first alternative, facilities would need to ensure that any 

modifications necessary to reduce TOHAP are in place and operating within 2 years of the final 

MACT rule effective date (rather than the 3 years typically provided). The commenter (0146) 

added that otherwise, facilities may not be able to ensure that the first month of rolling average 

calculation is in compliance. Alternatively, the commenter (0146) stated that EPA should allow a 

monthly TOHAP limit for the first 11 months to avoid forcing facilities into non-compliance 

simply because the facilities must comply with a computed rolling 12-month average.

Response to comment 13.2.1: In the final rule we have revised the MACT floor limits for 

process wastewater, and we revised the compliance requirements by removing the 12 month 

rolling average for compliance with the total organic HAP limit. The final rule requires that a 

monthly measurement of the wastewater be taken to determine compliance with the total nonvinyl chloride organic HAP limit. See sections V.E.2 and V.F of the preamble to the final rules 

for the response to this comment. 
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Comment 13.2.2: One commenter (0146) asked that EPA treat non-detects in the same 

fashion for wastewater as it does for other emissions streams for purposes of calculating MACT 

floors.

Response to comment 13.2.2: There were a limited number of vinyl chloride 

concentration values reported as below detection limit in the data received from the Vinyl 

Institute for process wastewater. In calculating the final vinyl chloride limits for process 

wastewater, we used the UPL to account for variability and also performed a representative 

method detection level analysis. The methodology used to determine a representative method 

detection level was consistent for both stripped resins and process wastewater. Details of these 

calculations can be found in the technical memoranda that support the final rule available in the 

docket.

Comment 13.2.3: One commenter (0146) disagreed with EPA‘s assertion that 

maintenance wastewater is not currently regulated by 40 CFR part 61. The commenter (0146) 

pointed out that the definition of in-process wastewater at §61.61(j) is sufficiently broad to 

capture any water coming into contact with VCM or PVC. The commenter (0146) also stated 

that the only water exempted from this definition, and thus the requirement for treatment, is 

water used to wash out equipment ―after the equipment has already been opened to the 

atmosphere in accordance with §61.64(a)(2) or paragraph (b)(6) of this section.‖ [See 40 CFR 

61.68(b)(9)(i)]. The commenter (0146) maintained that the proposed rule contains the same 

equipment opening standards at §63.11955 as the current rule at §§61.64(a)(2) and 61.68(b)(6), 

and that because the equipment had already met the equipment opening standards requiring 

removal of HAP [40 CFR 61.64(a)(2)] from reactors and [§61.68(b)(6)] other equipment, contact 

with HAP is minimized and treatment deemed unnecessary. 

Response to comment 13.2.3: The requirements for maintenance wastewater have been 

revised for the final rules. We do recognize that it may not be feasible to collect wastewater 

resulting from maintenance activities at PVC facilities such that it could be contained and routed 

to a wastewater treatment system, PVC facilities reported a variety of different work practices 

used to control emissions from maintenance wastewater. However, the facilities did not provide 

sufficient description or information necessary to determine the effectiveness of any one work 

practice alone or relative to other work practices. In the final rule we have decided to incorporate 

the maintenance wastewater work practice requirements used in other EPA standards, such as the 
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HON. These work practice standards include preparing a description of maintenance procedures 

for management of wastewater generated from the emptying and purging of equipment in the 

process during temporary shutdowns for inspections, maintenance, and repair and during periods 

which are not shutdowns. As done in the HON, facilities can effectively implement these work 

practices to prevent or mitigate the emissions of HAP from wastewater generated during 

maintenance activities. See section V.F.4 of the preamble to the final rules.

14.0 COMPLIANCE DATES

Comment 14.1: One commenter (0153) contended that EPA should add a provision to the 

PVC MACT allowing a facility to request an extension of a year or more of the compliance 

deadline in the event of force majeure, or in order to coordinate facility upgrades until after the 

EDC/VCM MACT is finalized. The commenter (0153) stated that because some PVC facilities 

will also be subject to the pending EDC/VCM MACT, such facilities will not be able to begin 

construction of certain necessary upgrades for PVC MACT compliance until after the 

EDC/VCM MACT is finalized. The commenter (0153) added that although the provision in 

subsection (e) allows operators to assert a claim of force majeure in connection with an initial 

performance test, the commenter asserts that EPA should add language to the final rule to allow 

an operator to obtain a temporary extension if agency review and delay or an event of force 

majeure occurs while negotiations are under way over a proposed test plan.

Response to comment 14.1: Commenters have requested additions to the provisions for a 

force majeure presented in §63.11900(e). The language in §63.11900(e) is provided as a 

clarifying courtesy on where the force majeure provisions are located in case affected sources 

should need them. Our intent to make the performance testing provisions of 40 CFR 63.7(a)(4) 

applicable to subpart HHHHHHH of part 63 is evident in Table 4 of the final rule. The 

flexibilities provided in §63.7(a)(4) should address the commenter‘s concerns. We have not 

proposed revised standards for EDC/VCM facilities nor have we proposed to revise the HON 

MACT to address emissions from EDC/VCM sources. Therefore, we cannot extend the PVC 

compliance dates at this time to coincide with any future rulemakings for EDC/VCM sources.

Comment 14.2: One commenter (0146) contended that in consideration of the intent of 

the CAA ―Special Rule‖ to enable compliance with a reasonably proposed standard, EPA should 
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revise the final rule to allow for new sources to come into compliance three years after the final 

rule is promulgated.

Two commenters (0146, 0144) argued that according to CAA §112(i)(2), sources that 

commence construction or reconstruction after proposal but before promulgation are not required 

to comply with promulgated standards until the date 3 years after the date of promulgation, and 

thus the proposed PVC MACT is unjustified in requiring new sources that start construction 

between proposal and promulgation to comply with the proposed standard upon startup. One 

commenter (0144) requested that the phrase "...effective date of publication of the final rule in 

the Federal Register..." replace all references to May 20, 2011 in proposed sections 63.11870(b), 

(c), and (d), in order to allow for continued expansions of PVC production capacity.

Response to comment 14.2: While the commenters refer to the ―Special Rule‖ provisions 

of CAA Section 112(i)(2), included in the General Provisions as 40 CFR 63.7(a)(2)(ix), they 

have failed to support their request with any explanation of how the two conditions contained 

within CAA Section 112(i)(2) are satisfied for the ―Special Rule‖ provision to apply to this 

rulemaking. Considering the final rule requirements, we do not believe condition (A) of CAA 

Section 112(i)(2) ―the promulgated standard, limitation or regulation is more stringent than the 

standard, limitation or regulation proposed‖ applies. See preamble Section IV.B and IV.F for 

discussion on when sources must comply with the major and area source standards and initial 

compliance requirements. Additional clarification on what a ―new affected source‖ means is 

provided in preamble Section V.A. 

15.0 DEFINITIONS AND TERMINOLOGY

Comment 15.1: One commenter (0143) argued that EPA should revise the proposed rule 

to promote the use of recovery devices whenever possible, and to exclude recovery devices from 

the definition of "destructive control devices." The (0143) commenter provided the agency a 

proposed definition of a recovery device. 

Three commenters (0143, 0146, 0153) disagreed with the agency‘s proposal to classify 

all recovery devices as control devices, and see no rationale for why "process condensers" are the 

sole type of "recovery device" that would be excluded from being a "control device." All three 

commenters (0143, 0146, 0153) propose that EPA amend the definition of "recovery device" as 

follows: "For purposes of this subpart, recovery devices may or may not be control devices;" and 
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that "control device" be defined as: ―...with the exceptions noted in this definition, a combustion 

device, some recovery devices, some recapture devices, or any combination of these devices 

used primarily to comply with this subpart.‖

Response to comment 15.1: See preamble Section V.D. for discussion on a very similar 

comment regarding calling vent gas absorbers ―recovery devices‖ and not ―control devices.‖ In 

our response to the comment, which applies to these comments as well, we point out that the 

final rule emission limits apply at the point where the gaseous stream is released to the 

atmosphere. The rule does not require that affected sources use a specific control or recovery 

device to meet the process vent limits, and the final emission standards are not based on whether 

a vent gas absorber is classified as a recovery device or control device. In the final rule we define 

recovery devices as ―an individual process component capable of and normally used for the 

purpose of recovering chemicals for fuel value (i.e., net positive heating value), use, reuse or for 

sale for fuel value, use or reuse.‖ We also state that ―for purposes of this subpart, recovery 

devices are control devices.‖

Comment 15.2: One commenter (0134) requested that EPA add the following sentence to 

the definition of wastewater ―Water used to wash out equipment after the equipment has already 

been opened to the atmosphere in accordance with §63.11955 is not wastewater.‖ The 

commenter (0134) contended that the proposed definition of wastewater is essentially the same 

definition as in-process wastewater (40 CFR 61.61(j)), and that this addition would preserve and 

carry forward the practice of minimizing HAPs in wash waters by requiring that equipment meet 

the applicable opening standards before the introduction of water for cleaning.

Response to comment 15.2: See preamble Section V.F.3. for discussion on emission 

source requirements for wastewater, including steps taken since proposal to address maintenance 

wastewaters. In the final rule maintenance wastewater is not subject to the same requirements as 

process wastewater but instead is subject to work practice standards. Therefore, the additional 

language that the commenter suggested is not necessary for the wastewater definition. 

Comment 15.3: One commenter (0146) proposed a new definition for maintenance 

wastewater and operational standard that addressed PVCPU–specific maintenance wastewater 

generating activities. The commenter (0146) then recommended that EPA promulgate a PVC 

MACT definition that addresses PVCPU–specific maintenance wastewater generating activities 
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and requires PVC MACT affected units to follow HON‘s maintenance wastewater requirements 

at 40 CFR. §63.105, with a slight variation to remove references to a Startup, Shutdown, 

Malfunction Plan.

Response to comment 15.3: See preamble Section V.F.3. for discussion on emission 

source requirements for wastewater, including steps taken since proposal to address maintenance 

wastewaters. In the final rule maintenance wastewater is not subject to the same requirements as 

process wastewater but instead is subject to work practice standards. Furthermore, we have 

clarified that certain safety-related streams are not considered wastewater. These two revisions in 

the final rule are consistent with wastewater provisions in other MACT standards, such as the 

HON and MON.

Comment 15.4: Several commenters (0134, 0143, 0146, 0142) addressed the proposed 

definition of in-process wastewater. One commenter (0134) noted that although EPA asserted 

that maintenance wastewater is not currently regulated by 40 CFR part 61, the definition of inprocess wastewater at §61.61(j) is sufficiently broad to capture any water coming into contact 

with VCM or PVC. The commenter (0134) goes on to request that the agency add the following 

sentence to the definition of wastewater: ―Water used to wash out equipment after the equipment 

has already been opened to the atmosphere in accordance with §63.11955 is not wastewater.‖ 

The commenter (0134) believe this addition will preserve and carry forward the practice of 

minimizing HAPs in wash waters by requiring that equipment meet the applicable opening 

standards before the introduction of water for cleaning. Another commenter (0143) contends that 

maintenance wastewater streams should be regulated independently of in-process wastewater and 

warrants use of a work practice standard because the capture of maintenance wastewater 

emissions is infeasible.

Another commenter (0142) requested that the term ―point of determination‖ be used 

throughout the wastewater provisions and that the term ―point of generation‖ be deleted from the 

rule entirely to be consistent with other part 63 NESHAP and to prevent confusion.

Response to comment 15.4: We disagree with the commenter, the part 61 definition for 

in-process wastewater is not included in the final rule since the definition of wastewater and 

process wastewater have been revised. See preamble Section V.F.3 for discussion on emission 

source requirements for wastewater, including steps taken since proposal to address maintenance 

wastewaters. In the final rule maintenance wastewater is not subject to the same requirements as 
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process wastewater but instead is subject to work practice standards. We have also removed all 

terminology related to ―point of generation‖ and ―point of determination.‖ These terms created 

confusion for determining compliance with the standards. The final rule includes simplified 

language regarding where process wastewater streams must be tested to determine if treatment is 

required to meet the process wastewater limits.

Comment 15.5: Several commenters (0153, 0146, 0142) addressed the proposed 

definition of storage vessels. One commenter (0153) supported the proposed definition in section 

§63.12005.

Some commenters (0146, 0142) disagreed with the proposed definition, stating that 

storage vessels containing gases and solid materials should not be included in the definition of 

storage vessels, and that the proposed definition is unprecedented when compared to the storage 

vessel definitions of some other MACT standards (such as Organic Liquids Distribution MACT, 

HON, and others).

Response to comment 15.5: We acknowledge one commenter‘s support on our proposed 

definition of storage vessel, and disagree with commenters that would have us remove storage 

vessels containing gases and solid materials from the definition. As we discuss in preamble 

Section V.A. on affected sources, we have revised the affected source definition to be the 

collection of one or more PVCPU and associated heat exchange systems, wastewater and process 

wastewater treatment systems, surge control vessels, and storage vessels. Therefore, storage 

vessels are included as part of the PVC production affected source, and materials in solid, liquid 

and vapor phases are stored in the PVC production process. To account for this, the final rule, in 

table 3, delineates the appropriate compliance requirements for storage vessels, depending on 

capacity and material vapor pressure that apply to each storage vessel type. 

Comment 15.6: One commenter (0142) proposed that pressure vessels be excluded from 

the definitions of storage vessels and process tanks because they have no emissions to the 

atmosphere. The commenter (0142) point out that EPA has listed pressure vessels as an example 

in the definition of process tank and also in the definition of storage vessel, although the storage 

vessel definition specifically excludes process tanks from being storage vessels; thus, the 

definitions should be altered accordingly.
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Response to comment 15.6: We disagree with the commenter. Pressure vessels can be 

used as storage vessels or process tanks. Pressure vessels are used to store liquids or gases and 

are designed not to vent to the atmosphere as a result of compression of the vapor headspace in 

the pressure vessel during filling of the pressure vessel to its design capacity. 

Comment 15.7: One commenter (0143) requested clarification of the term ―in vacuum 

service‖ with respect to the requirements in the proposed rule for closed vent systems which 

differentiate between "closed vent systems" and "closed vent systems in vacuum service.‖ The 

commenter (0143) recommended the term be defined as "the process component is operating at 

an internal pressure that is at least 5 kilopascals (kPa) (0.7 pounds per square inch absolute) 

below ambient pressure."

Response to comment 15.7: The final rule provides the following definition that 

addresses this comment: ―In vacuum service means that the process component is operating at an 

internal pressure that is at least 5 kilopascals (kPa) (0.7 pounds per square inch absolute) below 

ambient pressure.‖

Comment 15.8: One commenter (0153) stated that clarification is needed for the use of 

the terms ―operating scenario‖ and ―new operating scenario‖ because the current definitions are 

unclear and have ―circular references,‖ making it difficult to determine what types of events 

constitute a new operating scenario.

Response to comment 15.8: The term ―operating scenario‖ has been defined in the 

subpart, and means any specific operation of a regulated process as described by reports 

specified in §63.11985(b)(4)(ii) and records specified in §63.11990(e)(4). Although we believe 

the language of the rule is clear on what constitutes a ―new operating scenario‖ in 

§63.11985(b)(4)(ii), we will clarify here that a ―new operating scenario‖ is an operating scenario 

that has been operated since the time period covered by the last compliance report and has not 

been submitted in the notification of compliance status report or a previous compliance report. 

Comment 15.9: One commenter (0134) requested that the term ―hard piping‖ be replaced 

with the phrase ―closed conveyance system designed and operated to prevent exposure to the 
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atmosphere‖ or other similar wording, because ―hard piping‖ is not defined in subpart 

HHHHHHH.

Response to comment 15.9: In the final rule, we have added a definition for hard piping –

―hard piping means pipes or tubing that are manufactured and properly installed using good 

engineering judgment and an appropriate standard method published by a consensus-based 

standards organization if such a method exists or you may use an industry standard practice. 

Consensus-based standards organizations include, but are not limited to, American National 

Standards Institute (ANSI, 1819 L Street, NW., 6th floor, Washington, DC 20036, (202) 293–

8020, http://www.ansi.org).‖

Comment 15.10 One commenter (0146) proposed that the definition of bypass should be 

modified to include an exemption for attachments for temporary connections used for 

maintenance activities, so that operators may safely maintain their equipment without falling out 

of compliance with the rule. The commenter (0146) also stated that EPA is proposing to define 

―bypass‖ as the following: to direct a process vent or closed vent system stream to the 

atmosphere such that it does not first pass through an emission control device [76 FR 29596 (to 

be codified at 40 CFR. 63.12005)]. The commenter (0146) argued that this definition fails to 

provide an exemption for attachments for temporary connections used for maintenance activities. 

The commenter (0146) stated that maintenance conducted on closed vent systems is always used 

with a connection to a vacuum for removing or adding materials; under the HON, maintenance 

valves are exempt from process vent monitoring requirements because they are not truly capable 

of diverting the vent stream from a control device to the atmosphere. The commenter (0146) 

concluded by stating that in the final PVC MACT rule, EPA must provide the same types of 

exclusions as in prior standards so that operators may safely maintain their equipment without 

running afoul of the rule.

Response to comment 15.10: We disagree that there is a need for exemptions and 

exclusions as suggested by the commenter to the definition of ―bypass.‖ To the extent the 

commenter is referring to wastewater from maintenance activities, we suggest reviewing 

preamble Section V.F.3. for further discussion on our understanding of maintenance activities at 

PVC facilities. There is further discussion in preamble Section V.I. about our development of the 

definition of ―maintenance wastewater‖ that would seem to address many of the commenter‘s 

concerns. Lastly, preamble Section IV.A. states that a PVCPU includes ―equipment,‖ which in 
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turn includes items such as open-ended valves or lines, sampling connection systems, and 

pressure relief devices needed for safety purposes. Therefore, equipment leak provisions do 

apply to these types of equipment.

Comment 15.11: One commenter (0146) proposed that a definition be added for the term 

―by-product,‖ as used in the proposed PVC MACT definition of storage vessel. They suggested 

using the HON definition which is as follows: ―By-product means a chemical that is produced 

coincidentally during the production of another chemical.‖ The commenter (0146) contended 

that to account for this, the final rule, in table 3, delineates the appropriate compliance 

requirements for storage vessels, depending on capacity and material vapor pressure that apply to 

each storage vessel type. The commenter (0146) did not believe the term ―by-product‖ would 

provide any additional clarity on applicability of the rule.

Response to comment 15.11: We do not agree that a definition of ―by-product‖ is needed 

for the final rule nor do we agree that the proposed HON definition for ―by-product‖ is 

appropriate for this industry since no ―by-products‖ are made..

Comment 15.12: One commenter (0146) stated that gasholders meet the proposed PVC 

MACT definition of ―surge control vessel,‖ not ―fixed roof" storage vessel, or ―floating roof‖ 

storage vessel, or ―process tank.‖ Thus, the commenter (0146) stipulates that gasholders should 

be regulated as surge control vessels.

Response to comment 15.12: We agree that a gasholder meets the definition of a ―surge 

control vessel‖ and have revised the definition to clearly include gasholders. See preamble 

Section V.F.6. for discussion of the final rule standards for gasholders.

Comment 15.13: One commenter (0144) requested that EPA provide a definition on what 

constitutes a "double outboard seal" as is required to be installed on reciprocating compressors.

Response to comment 15.13: Since promulgation, we have revised the language for 

reciprocating compressors to read that HAP emissions ―are to be minimized by either installing 

double mechanical seals or equivalent equipment, or by complying with the requirements of 40 

CFR part 63, subpart UU for reciprocating pumps, rotating compressors, reciprocating 

compressors and/or agitators.‖ In 40 CFR 63 subpart UU the term ―dual mechanical seal pumps‖ 
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is synonymous with ―double mechanical seals.‖ See §63.1026(e)(1)(ii) for options of 

requirements for the dual mechanical seal system contained in 40 CFR 63 subpart UU. 

Comment 15.14: One commenter (0142) requested clarification for what constitutes a 

―release indicator.‖ The commenter (0142) has a series of indicators and alarms currently in 

place, and clarification of this term would allow him to determine the validity of his system.

Response to comment 15.14: See the discussion on equipment leaks in preamble Section 

V.F.1 for response to similar comments regarding pressure relief devices (PRD) and associated 

monitoring requirements. As discussed in the preamble and in the final rule, PRDs are required 

to be equipped with indicators that can identify and record the time and duration of each pressure 

release.

Comment 15.15: One commenter (0142) requested that the definition of ―maximum true 

vapor pressure‖ be revised to clarify whether it relates to only the stored HAP or the stored 

material/liquid in the vessel. The commenter (0142) stated that EPA improperly uses the terms 

―stored liquid‖ or ―stored material‖ instead of ―stored HAP‖ in the preamble when referring to 

the maximum true vapor pressure (defined as ―the equilibrium partial pressure exerted by the 

total HAP...‖). The commenter (0142) pointed out that the maximum true vapor pressure of the 

liquid or material in the vessel can be different than the maximum true vapor pressure of just the 

HAP constituents. The commenter (0142) provided examples of preamble text in which EPA 

uses ―material‖ or ―liquid‖ rather than ―HAP‖ when referring to maximum true vapor pressure.

Response to comment 15.15: It is our intent that ―maximum true vapor pressure‖ apply to 

total HAP. The definition of ―maximum true vapor pressure‖ is clear in this regard, and footnote 

1 of table 3 of the final rule states that the vapor pressure criterion for the storage vessel 

requirements means the ―Maximum true vapor pressure of total HAP at storage temperature.‖ 

Comment 15.16: One commenter (0142) stated that clarification is needed for the use of 

the terms ―deviation‖ and ―violation.‖ The commenter (0142) stipulates that though these terms 

are used interchangeably throughout the proposed rule, the use of the term ―violation‖ is 

incorrect because not all deviations are necessarily violations of the regulatory requirements.

Response to comment 15.16: The term ―deviation‖ is defined in §63.11890(d) and means 

any of the seven cases identified in that paragraph. While not all deviations are necessarily 
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violations of the rule‘s emissions limits, the deviations identified in §63.11890(d)(5)(i) through 

(iv), such as a pressure relief device in HAP service that discharges directly to the atmosphere, 

are immediate violations and have been specified as such. Moreover, all deviations must be 

recorded and reported as part of the semi-annual report where a compliance evaluation of the 

source, including deviations, will be initiated.

Comment 15.17: One commenter (0142) requested that EPA include provisions for 

process condensers that cannot meet the process condenser demonstration requirements because 

the condenser is not intended to remove HAP. The commenter (0142) stated that it is possible to 

have a process condenser (by the proposed definition) whose purpose is not to condense HAP 

material, and such a condenser may be operating properly yet unable to meet the demonstration 

requirements specified by the rule. The commenter (0142) suggested including such condensers 

in the Notification of Compliance status report with an explanation of why the process condenser 

requirements cannot be met, even when the condenser is operating as designed.

Response to comment 15.17: In response to this comment, we first want to note that the 

definition of control device expressly states that ―Process condensers are not control devices.‖ 

The final rule also defines a process condenser as ―a condenser whose primary purpose is to 

recover material as an integral part of a batch process.‖ The definition of ―process condenser‖ 

goes into further detail on what may constitute a ―process condenser‖ and cases where this 

definition does not apply. Therefore, we have acknowledged that for this rulemaking, process 

condensers are not control devices, and may be followed by a condenser acting as a control 

device or another type of control device. Regarding Notification of Compliance status reports, as 

specified in §63.11950(c)(ii), the final rule does not require a demonstration that a process 

condenser is properly operated if the process condenser is followed by a condenser acting as a 

control device or if the control device is monitored using a CEMS.

Comment 15.18: One commenter (0142) requested clarification for the terms ―annually,‖ 

―once per calendar year‖ and ―every 12 months,‖ saying that a requirement to conduct 

inspections  ̳ ̳annually,‘‘ could be read to mean in every calendar year, no later than the date 1 

year after the previous inspection, or in the same month every year. The commenter (0142) 

proposes that a definition of ―annual‖ be added to the rule, saying that ―annual‖ and ―every 12 

months‖ mean once per calendar year.
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Response to comment 15.18: It is our intent that where the terms ―annually‖ and ―every 

12 months‖ have been applied, an owner or operator may perform the required task at any time 

during the specified period, provided the task is conducted at a reasonable interval after 

completion of the task during the previous period. ―Calendar year‖ is defined in the final rule.

16.0 EMISSION LIMITS, OPERATING LIMITS, AND WORK 

PRACTICE STANDARDS

Comment 16.1: One commenter (0142) stated they believe that the PVC MACT rule sets 

standards that are more restrictive than standards set for other similar MACT subparts; some of 

EPA‘s decisions seem political and not based on collected data. One commenter (0141) 

requested that the PVC MACT rule should include Flexible Approaches consistent with Section 

4 of Executive Order 13563. The commenter (0141) stated that EPA should provide industry 

with a menu of pollution control and recovery equipment to achieve reductions all based on the 

best five performers.

Response to comment 16.1: The proposed and final standards are based on the data 

available to us. The legal framework for establishing MACT standards is set forth in section 

112(d) of the CAA, as discussed in the preamble to the proposed rule, and EPA‘s 

implementation of the MACT program as directed by the CAA may result in different levels of 

stringency for different emission points and HAP in different source categories. The proposed 

and final PVC MACT standards are based on the data relevant to the PVC source category and

available to EPA, as provided by the PVC industry. Based on additional information provided 

after proposal, we have revised the MACT floor and beyond the floor analyses in several 

respects for the final rules. See section V.E of the preamble to the rule for our discussion of these

changes. Additionally, in the proposed and final rules we generally set emission limits and did 

not specify control technologies that should be used to meet the emission limits. A facility can 

use any control technology or technique to meet the limits, which provides flexibility and choice 

in complying with the final standards. 

We provide compliance and operating parameter requirements for common controls that 

might be used for different types of emission points. For the impacts analysis, we estimated the 

costs based on likely controls that would be used by facilities. However, we did not prescribe the 
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technology that facilities should use to meet the limits. We believe the final rule is not 

inconsistent with Section 4 of Executive Order 13563.

17.0 GENERAL SUPPORT OF OTHER COMMENTERS

Comment 17.1: One commenter (0134) stated that he agrees with the recalculated process 

vent MACT floors as submitted by the VI Working Group (0146). The commenter (0134) 

provided the recalculated process vent MACT floors in a table of page 14 of his comments.

Response to comment 17.1: EPA has addressed the statements of all commenters, and 

responses to specific comments are found in the appropriate section of this document and in the 

preamble to the final PVC standards.

Comment 17.2: Six commenters (0126, 0133, 0136, 0147, 0153, 0142) support the 

comments submitted by the American Chemistry Council (ACC). ACC themselves also 

expressed support for comments submitted by ACC Vinyl Chloride Health Committee and 

ACC‘s chlorine Chemistry Division. 

Response to comment 17.2: EPA has addressed the statements of all commenters, and 

responses to specific comments are found in the appropriate section of this document and in the 

preamble to the final PVC standards.

Comment 17.3: Twenty-one commenters (0126, 0131, 0133, 0134, 0136, 0137, 0139, 

0141, 0142, 0143, 0145, 0147, 0151, 0152, 0153, 0156, 0158, 0159, 0160, 0164, PH-BR-0009) 

expressed support for comments submitted by the Vinyl Institute (VI). Another commenter 

(0135) urged EPA to consider the technical comments submitted by the Vinyl Institute and other 

stakeholders. 

One commenter (0134) particularly supported the argument submitted by VI that the heat 

exchange system leak action levels for new and existing sources and monitoring frequencies for 

new sources are without precedent and the most stringent issued by EPA to date. Commenter 

(0134) also specifically expressed support for the VCM and TOHAP limits for suspension resin 

produced at new and existing sources submitted by VI. One commenter (0139) expressed support 

for the floor limits proposed based on sub-categorization within VI‘s comments. Another 

commenter (0142) supported VI‘s comments on delay of repair provisions for heat exchanger 
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leaks. The commenter (0145) agreed with the comments VI submitted regarding the impact on 

PVC resin suppliers and suggested changes based on scientific data and the final impact on our 

economy. Commenter 0158 also supported VI‘s comments regarding the impact of PVC MACT 

regulations on suppliers. Commenter (0153) specifically supported the recalculation of the 

stripped resin emission limitations, use of Method 107 data in lieu of Method 8260 for vinyl 

chloride data, and recalculation of RVCM limits at the wastewater stripper. Commenter (0160) 

supported VI‘s comments pertaining to gasholders and argues that methods enumerates within 

VI‘s comments are the only practical and effective means of controlling emissions from these 

unique sources.

Response to comment 17.3: EPA has addressed the statements of all commenters, and 

responses to specific comments are found in the appropriate section of this document and in the 

preamble to the final PVC standards.

Comment 17.4: Three commenters (0134, 0141, 0153) supported the comments 

submitted by Occidental Chemical Corporation/OxyVinyls (OCC).

Response to comment 17.4: EPA has addressed the statements of all commenters, and 

responses to specific comments are found in the appropriate section of this document and in the 

preamble to the final PVC standards.

Comment 17.5: One commenter (0154) supported comments submitted by PolyOne 

Corporation, Shintech Inc., Westlake Chemical Corporation, Formosa Plastics Corporation, 

Society of the Plastics Industry (SPI), and Resilient Floor Covering Institute (RFCI). 

Response to comment 17.5: EPA has addressed the statements of all commenters, and 

responses to specific comments are found in the appropriate section of this document and in the 

preamble to the final PVC standards.

Comment 17.6: Five commenters (0133, 0134, 0141, 0151, 0152) supported comments 

submitted by the PVC MACT Working Group.

Response to comment 17.6: EPA has addressed the statements of all commenters, and 

responses to specific comments are found in the appropriate section of this document and in the 

preamble to the final PVC standards.
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Comment 17.7: One commenter (0133) supported comments submitted by Chemistry 

Council of New Jersey (CCNJ) member companies. 

Response to comment 17.7: EPA has addressed the statements of all commenters, and 

responses to specific comments are found in the appropriate section of this document and in the 

preamble to the final PVC standards.

Comment 17.8: Two commenters (0136, 0149) supported comments submitted by the 

National Association of Manufacturers (NAM). 

Response to comment 17.8: EPA has addressed the statements of all commenters, and 

responses to specific comments are found in the appropriate section of this document and in the 

preamble to the final PVC standards.

18.0 IMPACTS

18.1 General

Comment 18.1.1: One commenter (0157) expressed concern that the restrictions to 

emissions limits and to the number of chemicals individually regulated add significant burdens to

manufacturers. The commenter (0157) added that an equally effective and pragmatic approach 

was proposed with the vacated 40 CFR part 63 subpart J, in which Vinyl Chloride was used as a 

surrogate. The commenter (0157) stated that the additional burden in the proposed rule 

associated with the recordkeeping, reporting, sampling and testing requirements does little to 

reduce the quantity of HAP that is released to the atmosphere. One commenter (0147) stated that 

industry has already reduced chlorinated chemical emissions to air and water significantly since 

1988 and the limited reductions from the proposed rule are not warranted in light of the 

substantial economic burden. 

Response to comment 18.1.1: The final rule contains several revisions that reduce the 

annualized cost of the final rule by 75 percent from proposal and the subcategories and MACT 

floor calculations have been revised resulting in revised emission limits. These changes reduce 

the burden of the rule on industry, e.g., 15 out of 16 facilities were determined to be able to meet 

the stripped resin limits without additional modifications or controls. We did not find the 

approach previously promulgated, which relied on vinyl chloride as a surrogate for other HAP, 
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and subsequently vacated by the court to be an appropriate approach for this rulemaking. The 

rationale and supporting analysis for the final standards and associated compliance provisions 

can be found in the preamble to the final rule as well as supporting memos in the docket. We 

also analyze impacts in the preamble to the final rule and provide in the docket a revised cost 

analysis memo.

18.2 Air

Comment 18.2.1: One commenter (PH-BR-0010) stated that for environmental justice 

community members living in close proximity to PVC production facilities, the reductions 

achieved by the proposed rule are not adequate. This commenter contended that reductions 

would account for only 30% of the vinyl chloride and 32% of the dioxins/furans currently 

emitted. The commenter (PH-BR-0010) noted that vinyl chloride fugitive emissions comprise 55 

to 78 percent of the total vinyl chloride air emissions and that even with the proposed standards 

the ambient air will continue to be contaminated with HAPs. 

Response to comment 18.2.1: EPA believes that the final rule reduces emissions from 

PVC facilities under the authority provided by the Clean Air Act. In a future rulemaking we will 

conduct further analyses in a risk and technology review to determine whether any remaining 

risk or developments in technology warrants revision or updating of the final MACT standards in 

this rulemaking.

Comment 18.2.2: One commenter (0144) disputed EPA‘s claim in the preamble that the 

proposed standard will result in significant reduction in dioxin/furan emissions. They stated that 

all nine of their thermal oxidizers are well below the limits and, therefore, there will not be any 

rule-related reductions on account of the proposed standard. 

Response to comment 18.2.2: While the limits may not significantly reduce the 

CDD/CDF emissions at the particular facility the commenter describes, the final emission 

standards will reduce CDD/CDF emissions overall from the PVC production source category.

Comment 18.2.3: One commenter (0157) recommended a change in the methodology for 

calculating emissions for the dispersion resin production process. The commenter (0157) cited 

the Preamble, "For stripped resins, we calculated emissions assuming that all HAP remaining in 
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the resin would eventually be emitted from processes downstream of the resin stripper." The 

commenter (0157) contended that in the dispersion production process this is not a correct 

statement since the material is sold un-dried as a liquid. The commenter (0157) added that the 

significant residual HAP is highly soluble in water and lends itself to the total HAP residual 

emission reduction from the dispersion process being something approaching zero tons per year. 

The commenter (0157) argued that EPA needs to reevaluate those assumptions and remove from 

the emissions limit those soluble HAPs in dispersion grades sold un-dried.

Response to comment 18.2.3: The commenter did not provide any data to indicate which 

of their dispersion resin grades are sold un-dried as a liquid to 1) revise our calculation of 

emissions from processes downstream of the resin stripper, and 2) remove from the emission 

limit those soluble HAPs in dispersion grades sold un-dried. We did not receive comments from 

other manufacturers stating that we should re-evaluate our estimate of emissions from dispersion 

resins by not assuming all HAP would eventually be emitted. Therefore, to remain consistent 

with our estimate of emissions from suspension, suspension blending, and copolymer resins, we 

have retained our assumption that all HAP remaining in the resin would eventually be emitted 

from processes downstream of the resin stripper for a conservative estimate of baseline 

emissions reductions. 

Comment 18.2.4: One commenter (0153) suggested further emissions need to be 

accounted for in the Secondary Impacts Memorandum. Citing EPA‘s claim that the use of 

additional steam will improve both resin and wastewater strippers, the commenter (0153) 

claimed there will be secondary boiler emissions related to this steam. The commenter (0153) 

added that additional steam will require more fuel to boilers or additional boiler capacity, 

increasing greenhouse gases and other pollutants.

Response to comment 18.2.4: In the final standards we are not estimating impacts 

assuming the use of additional steam to meet the stripped resin or wastewater limits. We have 

estimated that 15 out of 16 sources can meet the resin limits without installation of additional 

controls. Our cost and impacts estimates for the one facility that we believe will need to install 

controls are based on replacing their existing stripper with a new stripper that will allow the 

facility to meet the final stripped resin standards. We are not anticipating that additional steam 

will be necessary once the equipment is replaced. For wastewater, we estimated that minimal to 

no additional steam will be needed to comply with the wastewater standards. See the 
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memorandum Revised Costs and Emission Reductions for Major Sources in the Polyvinyl 

Chloride and Copolymers (PVC) Production Source Category.

18.3 Cost

Comment 18.3.1: One commenter (0157) is concerned that costs were not properly taken 

into account with regard to the MACT floors and the controls necessary to meet them. This 

commenter (0157) calculated a dollar per ton of HAP reduced for process vents, stripped resin, 

wastewater, equipment leaks, and heat exchange systems and noted they are very high. The 

commenter (0157) added that the Clean Air Act §112(d)(2) states that the cost of achieving such 

emission reductions must be taken into account when setting MACT standards. The commenter 

(0157) provided the following quotes from the HON Residual Risk analysis regarding cost 

effectiveness of controls: "Based on this analysis, 96 percent of the facilities had cost per ton of 

HAP removed exceeding $12,000 per ton of total HAP reduced. The average cost per ton of 

HAP removed for controlling Group 2 wastewater streams was approximately $410,000 per ton 

of HAP reduced. Considering these high costs, we concluded that it is not reasonable to require 

additional controls for Group 2 wastewater streams, in light of the minimal risk reduction 

obtained if additional controls were to be imposed." (71 FR 34434, 6/14/2006) "The cost of 

controlling emissions from transfer operations ranges from approximately $10,000 per ton of 

HAP to over $100,000 per ton of HAP if there are already existing control devices that may be 

used to reduce emissions. If a new combustion device or vapor recovery device is also needed, 

the cost increases significantly. As a result, further controls for transfer operations are not 

included in either of our two proposed options discussed below." (71 FR 34435, 6/14/2006) The 

commenter (0157) contended that with that understanding and the latitude afforded in 

§112(d)(4), the agency should exercise its discretion to take into consideration the residual risk 

associated with the HAPs emitted from the Polyvinyl Chloride process and set the standard "with 

an ample margin of safety."

Response to comment 18.3.1: The commenter‘s concern about how costs were taken into 

account in determining MACT floors is misplaced; EPA may not consider costs in setting the 

MACT floor. Cost estimates associated with meeting MACT floor levels of control, such as 

those in the memorandum Revised Costs and Emission Reductions for Major Sources in the 

Polyvinyl Chloride and Copolymers (PVC) Production Source Category, are provided for 
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informational purposes only and are not considered in determining the MACT floor. Costs and 

other factors may be considered in EPA‘s beyond-the-floor analysis, as shown in the

memorandum Revised Beyond-the-Floor Analysis for the Polyvinyl Chloride and Copolymers 

(PVC) Production Source Category

For the final rule, we revised the cost analyses based on comments and additional data 

submitted by commenters. The final rule does not incorporate the HON requirements for 

regulating total organic HAP as a beyond-the-floor option for wastewater. Instead, we have 

determined the wastewater emission limit using a UPL calculation as a MACT floor compliance 

requirement. Based on the available data, we believe the costs associated with the final rule are 

sufficiently accounted for. 

Comment 18.3.2: One commenter (0144) disagreed that no new PVCPU facilities will be 

constructed in the next five years. Economic impacts from the new source MACT should be 

examined. 

Response to comment 18.3.2: We have revised the definition of affected source and new 

source in the final standards. See section V.A for our discussion of the changes. Based on the 

revised definition and the information that we have, we do not anticipate any PVC facilities will 

be subject to the new source requirements in the next five years, in which case there would be no 

new source cost impacts. See also section V.E.2 of the preamble to the final rule.

18.4 Non-Air Quality Health, Environmental, and Energy

Comment 18.4.1: Three commenters (PH-BR-0004, PH-BR-0005, PH-BR-0010) are 

concerned about the inadequacy of emissions reductions from the rule. One commenter (PH-BR0004) contended that the proposed regulation creates too many exemptions for the PVC industry. 

The commenter further stated that the regulation is contrary to EPA Administrator, Lisa 

Jackson's, commitment to Environmental Justice, and more importantly, continues to ignore their 

human rights to a healthy environment. One commenter (PH-BR-0005) stated that in their 

community they are suffering from cancer-causing chemicals from these facilities on a daily 

basis, including dioxin. The commenters state that Mossville residents have an average blood 

dioxin level three times the national average; the three times the national average of dioxin in 

their body was researched by one of the best environmental scientists in the country, showing 
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that dioxins in the blood are the same kind of dioxins released by the industrial facilities near 

Mossville. The commenter (PH-BR-0004) concluded that they understand industry needs jobs, 

but they need their young people to live. Another commenter (PH-BR-0010) encouraged EPA to 

reduce the quantity of vinyl chloride, hydrogen chloride, dioxins and furans, and hazardous air 

pollutants emitted by further tightening up the emission limits in the proposed rule. The 

commenter (PH-BR-0010) added that dioxins and furans are released and have the potential to 

and, in fact, have contaminated and bio-accumulated in the bodies of the human population in 

the fence line communities of PVC facilities. The commenter (PH-BR-0010) stated that the 

reduction in emissions proposed by EPA will reduce the exposure of the Environmental Justice 

communities, but there will still be unacceptable levels of exposure to vinyl chloride, dioxin and 

furans, and hazardous air pollutants in the air of these communities.

Response to comment 18.4.1: In accordance with section 112(d)), of the CAA, this final 

rule sets technology-based emission standards for major sources pursuant to section 112(d)(2) 

and (d)(3) that will reduce emissions associated with the PVC source category. After the sources 

in the category comply with the final MACT standards, we will determine in a future rulemaking 

whether unacceptable health risks remain from the PVC facilities that are the subject of the 

MACT standards, see section 112(f)(2), and if so, we will take further action to eliminate any 

unacceptable risks. We also recognize that some communities may face greater risks due to 

exposures to multiple chemicals through multiple media. This rule sets emission standards for 

hazardous air pollutant emissions from the PVC production source category. Accordingly, the 

rule does not address other sources of emissions that may pose risk to a community. For that 

reason, we continue to recommend that communities work with State and local governments to 

address risks of a more cumulative nature based on the unique characteristics of those 

communities and industries located in them.

We disagree that this regulation is contrary to EPA Administrator Lisa Jackson‘s 

commitment to environmental justice. In order to determine the potential for disproportionate 

impacts on minority and low income populations that this rule could help reduce or eliminate, a 

demographic analysis was conducted. Please see the preamble to final rule and related technical 

support materials for a discussion of the demographic analysis. EPA has determined that this 

final rule will not have disproportionately high and adverse human health or environmental 

effects on minority or low-income populations because it increases the level of environmental 

protection for all affected populations without having any disproportionately high and adverse 
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human health or environmental effects on any population, including any minority or low-income 

population. 

As explained above and in the preamble to the final rule and the technical memorandum

entitled Revised Maximum Achievable Control Technology (MACT) Floor Analysis for the 

Polyvinyl Chloride and Copolymers (PVC) Production Source Category, we revised the final 

standards based on new data received in response to the proposal. In response to comments and 

after consideration of the data in the record, we also created additional subcategories for process 

vents and stripped resin. As a result of these changes, we revised the emission standards for 

process vents and stripped resins. We also made revisions to the requirements for process 

wastewater and heat exchange systems. For more information on the changes to the emission 

limits, with a particular emphasis on changes to emission limits for vinyl chloride, hydrogen 

chloride, total organic HAP and dioxin and furans, please see the final rule and associated 

technical support materials.. Further analysis to determine whether any additional reductions in 

emissions are needed will be conducted pursuant to section 112(d)(6) and (f)(2) after industries 

have complied with these new final standards. 

Comment 18.4.2: Two commenters (0126, 0147) expressed concern that the proposed 

MACT rule imposes a high economic burden for limited environmental or public health benefit. 

One commenter (0126) contended that the additional cost for complying with the proposed 

MACT standard cannot be justified.

One commenter (0126) argued that existing regulatory controls for vinyl chloride are well 

established and are considered to provide effective protection to the general population from 

potential, de-minimus vinyl chloride emissions. The commenter (0126) stated that scientific 

consensus considers angiosarcoma as the sole potential cancer outcome for both animals and 

highly exposed workers, and angiosarcomas are a very rare occurrence in the general US 

population (approximately 30 new cases per year), and the diagnosis is readily apparent to 

medical professionals. The commenter (0126) added that existing health protective regulatory 

standards are effective given the extremely low incidence of this tumor type. The commenter 

(0126) also noted that EPA‘s previous review of the health hazard associated with vinyl chloride 

(IRIS review) concluded that concern is associated only with occupational exposures at 

uncontrolled high concentrations and for one target organ. The commenter (0126) cited EPA

Toxicological Review of Vinyl Chloride available on IRIS. This commenter (0126) 
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recommended that EPA update its risk assessment for this proposed NESHAP, and submit that 

update for public review and comment. 

Response to comment 18.4.2: This rule is being adopted to meet the technology-based 

requirements of sections 112(d)(2)-(3) and 112(d)(5). Section 112(d)(2) and (3) require 

emissions to be controlled to levels achieved by the best-performing sources in the category or 

subcategory. Section 112(d)(5) authorizes the Agency to set standards for area sources that 

require the use of generally available control technologies or management practices. The 

technology-based standards we have set in this final rule will result in HAP reductions. See the 

preamble for the final PVC rules for our discussion of the MACT and GACT standards adopted. 

The information the commenter has provided is relevant to the Agency‘s residual risk review 

under section 112(f), which occurs within 8 years of the Agency setting MACT standards. See 

Sierra Club v. EPA, 353 F.3d 976, 988-89 (D.C. Cir. 2004) (rejecting consideration of risk as 

part of beyond the floor analysis).

 

19.0 MACT FLOOR, GENERAL

Comment 19.1: A commenter (0150) argued that EPA‘s floor approach is unlawful and 

arbitrary. The floors must reflect the ―average‖ emission limitation achieved by the five best 

performing sources. 42 U.S.C. § 7412(d)(3). The commenter (0150) stated that floors should not 

be set at a level that the best performers could never exceed even when they operate poorly or 

fail to maintain their control equipment. The commenter (0150 stated that using an upper 

prediction limit to set standards reflecting the statistical worst performance does not yield an 

accurate picture of performance. Instead, the commenter (0150) stated, they reflect a fictional 

number that exceeds that ―average‖ by more than 100%. Although the commenter (0150) 

recognized that EPA may consider variability in calculating the best sources‘ performance, it 

contended that EPA‘s method of considering variability, however, seeks to assure that none of 

the sources among those identified as best performers would ever exceed the floor level. The 

commenter (0150) added that approach ignores the reality that sources‘ emission levels are 

largely within their control. The commenter (0150) stated that a great deal of variability may be 

statistically conceivable if EPA chooses a high enough prediction limit (in this case the 99th 

percentile); however, that does not mean that a well run source actually would experience such 
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variability. The commenter (0150) concluded that one of the main points of having emission 

standards is to ensure that sources not only deploy the appropriate control measures but also use 

those control measures properly and consistently to minimize emissions.

Response to comment 19.1: In assessing sources‘ performance, we may consider 

variability both in identifying which performers are ―best‖ and in assessing their level of 

performance. Sierra Club v. EPA (Brick MACT), 479 F. 3d 875, 881-82 (D.C. Cir. 2007); see 

also Mossville Environmental Action Now v. EPA, 370 F.3d 1232, 1241–42 (D.C. Cir 2004) 

(EPA must exercise its judgment, based on an evaluation of the relevant factors and available 

data, to determine the level of emissions control that has been achieved by the best performing 

sources considering these sources‘ operating variability). The Brick MACT decision indicated 

that floors for existing sources must reflect the average emission limitation achieved by the bestperforming existing sources. The Brick MACT decision also reiterated that we may account for 

variability in setting floors; however, the Court found that we erred in assessing variability 

because we relied on data from the worst performers to estimate best performers‘ variability. 

The Court held that ―EPA may not use emission levels of the worst performers to estimate 

variability of the best performers without a demonstrated relationship between the two.‖ 479 F. 

3d at 882.

The MACT floor limits were developed by incorporating variability, as has been done in 

other MACT standards. In determining the MACT floor limits, we first determine the floor, 

which, for existing sources in a category or subcategory with fewer than 30 sources, is the 

emissions limitation achieved in practice by the average of the top 5 existing sources, or the level 

achieved in practice by the best controlled similar source for new sources. In setting numerical 

emission limits, EPA used the lowest emissions as the measure of best performance . We then 

assess variability of the best performers by using a statistical formula designed to estimate a 

MACT floor level based on the average of the best performing sources using the expected 

distribution of future compliance tests. As explained in the preamble to the proposed rule we 

used the UPL because for a future observation, the UPL will, with a specified degree of 

confidence, contain the next (or some other pre-specified) randomly selected observation from a 

population. In other words, the prediction interval estimates what future values will be, based on 

present or past background samples taken. For this source category, where there is a limited 

sampling of the source category, the UPL was used to determine variability. Because the UPL 

represents the value which we can expect the mean (i.e., average) of three future observations (3-
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run average) to fall below, based upon the results of the independent sample size from the same 

population, the UPL reflects average emissions. The final rule makes one exception in using the 

UPL to calculate variability. We maintain that the MACT floor analyses conducted for the final 

PVC rules are appropriate and are consistent with section 112(d) of the CAA. 

Comment 19.2: One commenter (0157) argues that the Vinyl Chloride NESHAP was 

published in the 1970‘s. At that time, the NESHAP represented a paradigm shift in the method 

by which emissions were regulated. EPA should take into account that in the past 19 years the 

production population has remained effectively unchanged, but the emission baseline (and 

residual risk) of this industry is considerably lower. 

Response to comment 19.2: For the proposed and final rule, we estimated baseline 

emissions for the industry based on information and data available to us that represent the current 

state of the industry. See the preamble for the final rule for more details on our baseline emission 

estimates for the final rule.

20.0 REGULATED POLLUTANTS

Comment 20.1: One commenter (0142) requested that EPA correct that dibenzofuran is 

not a polychlorinated dibenzofuran or a chlorinated dibenzofuran (CDF) on page 29541.

Response to comment 20.1: The preamble to the proposed rule did not claim that 

dibenzofuran was a polychlorinated dibenzofuran or a chlorinated dibenzofuran. The preamble 

merely stated that dibenzofurans are identified by name as a HAP. 

21.0 REGULATORY OVERLAP

Comment 21.1: One commenter (0157) stated that the apparent development of a 

consolidated ―Chemical Sector MACT‖ would contain significant overlap with the PVC MACT 

and raise questions of applicability, and thus the PVC MACT should be consolidated into the 

Chemical Sector MACT instead of promulgating the proposed rulemaking. One commenter 

(0157) argued that EPA should consolidate the PVC rule with the Chemical Sector MACT that 

EPA is currently developing alongside the PVC MACT because the current approach creates 

confusion, uncertainty, and unnecessary cost to the business community as a result of the time 
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and capital expense of reviewing multiple iterations of rules, especially considering that this is a 

two-step process (i.e., development of the MACT floor, followed by residual risk review).

Response to comment 21.1: The response to these comments is in Section V.B of the 

preamble to the final PVC rules. We also note that we have not proposed a chemical sector 

MACT standard. Additional delay to consider any such rules would have been inconsistent with 

the rulemaking deadline for PVC in the settlement agreement entered into by the Agency.

Comment 21.2: Commenter (0134) stated that open-ended lines of bypass streams are 

already regulated under subpart UU, §63.1033 as follows: (b) Equipment and operational 

requirements. (1) Each open-ended valve or line shall be equipped with a cap, blind flange, plug, 

or a second valve, except as provided in 63.1021(b), 63.1036, 63.1037, and paragraphs (c) and 

(d) of this section. The cap, blind flange, plug, or second valve shall seal the open end at all 

times except during operations requiring process fluid flow through the open-ended valve or line, 

or during maintenance. The operational provisions of paragraphs (b)(2) and (b)(3) of this section 

also apply. 

Response to comment 21.2: We agree with the commenter that open-ended lines are 

regulated under subpart UU, and the final standards require sources to comply with the subpart 

UU level 2 requirements for equipment leaks. We are specifically regulating bypass lines in this 

rule by requiring the installation, maintenance, and operation of flow indicators in closed vent 

system bypass lines or that bypass valves be secured in a non-diverting position with a car-seal 

or a lock-and-key type configuration. Either of these requirements must be met to prevent and 

detect bypass of the control device. 

Comment 21.3: Two commenters (0153, 0146) agreed with EPA‘s proposal to sunset the 

part 61 Vinyl Chloride NESHAP once facilities are operating in compliance with all applicable 

sections of the final PVC MACT rule. However, one commenter (0153) argued that the part 61 

Vinyl Chloride NESHAP should remain in effect for PVC facilities co-located with EDC/VCM 

facilities and for PVC facilities that are area sources, until rules for EDC/VCM facilities and the 

PVC GACT rule are finalized. The commenter (0153) requested that, under these circumstances, 

EPA clarify the overlapping and potentially conflicting requirements under the various 

regulations by preparing a side-by-side table to inventory the current part 61 requirements and 
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the corresponding new part 63 requirements, as well as to identify new requirements and any 

reduced requirements for area sources. 

One commenter (0146) pointed out that, for Title V purposes, the proposed rule should 

address additional overlap issues with the part 61 VCM NESHAP. The commenter (0146) 

suggested language that EPA should add to the final rules. The commenter (0146) pointed out 

that the rule needs to be very clear about the break with the VCM NESHAP because the VCM 

NESHAP directs certain affected sources to comply with part 61 subpart V for leak detection and 

repair. The commenter (0146) suggests that in §63.11871 (What is the relationship to 40 CFR 

part 61, subpart F?), after the applicable compliance date specified in §63.11875(a), (b), or (c), 

the rule should specify that an affected source that is also subject to the provisions of 40 CFR 

part 61, subparts A, F, and V, is required to only comply with the provisions of this subpart and 

not 40 CFR part 61, subparts A, F, and V.

Response to comment 21.3: We have addressed overlap with the part 61 standards in the 

final PVC rules. See the response in Section V.B of the preamble to the final rule regarding the 

final rule requirements when other regulations overlap with the PVC standards. Additionally, 

the final PVC rules are more stringent or equal to the existing part 61 NESHAP standards for 

PVC facilities for all emission points. Therefore, we are not aware of any issues or conflicting 

requirements between the part 61 standards and the final PVC rules.

22.0 RESIN MORPHOLOGY

Comment 22.1: Several commenters (PH-BR-0003, PH-H-0003, 0134, 0151, and 0153) 

provided information on the morphology of PVC resins. The commenters stated that each PVC 

resin grade has unique physical characteristics known as particle morphology. The commenters 

added that this uniqueness is necessary in order to make the variety of PVC products. The 

commenters stated that PVC facilities need regulatory flexibility in order to produce a full 

complement of different resins that are used for diverse final products, such as vinyl siding, PVC 

pipe, window frames, electrical wiring insulations, roofing, credit cards, and a host of other 

applications. One commenter (0151) stated that even amongst similar grades of resins, PVC resin 

morphology plays a role in a resin‘s ability to be stripped of VCM and other hazardous air 

pollutants (HAPs). One commenter (0153) stated that different grades of resin exhibit differing 

particle morphologies that have a significant impact on strippability, with different resultant 
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levels of RVCM remaining in the PVC product. Depending on the particular grades being 

manufactured at a suspension PVCPU, the RVCM will vary substantially depending on the 

weighted average production of easy-to-strip versus hard-to strip grades, on a daily, monthly and 

annual average basis, no matter what the specific design and operating parameters may be for the 

PVCPU‘s slurry steam stripper(s).

Response to comment 22.1: We thank the commenters for their input and information. 

We have considered the information on morphology when developing the subcategories in the 

final PVC rules. See section V.D of the preamble to the final PVC rules.

23.0 RULE

23.1 General

Comment 23.1.1: One commenter (PH-BR-0002) supported EPA‘s selection of emission 

points and evaluation of HAPs.

Response to comment 23.1.1: We appreciate the input and support of the commenter on 

this matter.

23.2 Format

Comment 23.2.1: One commenter (0146) supported EPA‘s selection of a stripped resin 

format to control HAP emissions from downstream processes, as well as the concentration limit 

format for demonstrating compliance using the resin stripper format. The commenter (0146) 

explained that the stripped resin format is the best means and the concentration limit is the most 

direct way of demonstrating compliance for stripped resin.

Response to comment 23.2.1: We appreciate the input and support of the commenter on 

this matter.

Comment 23.2.2: One commenter (0146) made the point that the proposed CPMS 

requirements discourage the use of recovery control devices to control emissions. The 

commenter (0146) provided an example that a process absorber that produces HCl for use, as 

distinguished from final control device scrubbers, should not be subject to low pH limits unless it 

is the final emission control device before discharging to the atmosphere.
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Response to comment 23.2.2:: The final rule requires that process vents from PVCPUs be 

controlled to the emission limits in the standards. The CPMS requirements only apply to the 

control device used to meet the emission limits. If a facility uses recovery devices as defined in 

the final rule, such as condensers or absorbers, as part of their vinyl chloride recovery system, 

the vent stream from the condenser or absorber must meet the emission limits for process vents. 

See preamble Section V.D. regarding calling vent gas absorbers ―recovery devices‖ and not 

―control devices.‖ The rule does not require that affected sources use a specific control or 

recovery device to meet the process vent emission limits, and the final emission standards are not 

based on whether a vent gas absorber is classified as a recovery device or control device.

24.0 STARTUP, SHUTDOWN, AND MALFUNCTIONS

Comment 24.1.: One commenter (0143) contended that the proposed rule indicates that 

the typical exclusion for startup and shutdown events, listed in Section 63.7(e)(1) of the general 

provisions, will be removed. The commenter (0143) stated that the implied assumption is that the 

proposed emissions limits apply during startup and shutdown, as well as during normal 

operations. 

Two commenters (0143, 0153) were concerned about THC performance testing with 

regard to startup, shutdown, and malfunction (SSM) events. The commenters (0143, 0153) 

contended that SSM events cannot be included in the scope of the proposed emissions limits if 

the expectation is to require compliance performance tests under normal operating conditions, 

without SSM events. The commenters (0143, 0153) further argued that since stack test data did 

not contain startup, shutdown, or malfunction events then the emission limits should not be 

applicable during these periods as there is no data to support this. One commenter (0143) 

indicated the instructions on page three of CAA section 114 request, Enclosure 1, instructed 

facilities not to include startup and shutdown events in the sampling period, and thus startup and 

shutdown events should be exempted. Two commenters (0143, 0153) also stated that EPA must 

provide clarification to indicate that performance testing need not be conducted during startup 

and shutdown conditions. Since the THC MACT floor data provided to EPA did not include 

SSM emissions, one commenter (0144) requested that EPA re-analyze the MACT floor data to 

revise the proposed regulatory requirements or ask the facilities for additional and more specific 

data related to SSM emissions. One commenter (0153) contended that EPA should expressly 
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state in the final rule whether sampling need or need not be conducted during startup and 

shutdown conditions. The commenter (0153) stated that proposed Table 5 indicates that the 

exemption in 40 CFR §63.7(e)(1) will no longer apply, which implies that startup and shutdown 

conditions are to be included in performance testing. The commenter (0153) pointed out that this 

is contrary to EPA‘s message at the public meeting on June 30, 2011 that stack testing of process 

vents and data gathering was to be done under ―normal‖ operations, not including startup, 

shutdown or malfunction events.

Response to comment 24.1: The comment that asserts that the limits apply at all times, 

including during startup and shutdown, is correct. Based on our review of the commenters‘ 

concerns, we do not find any need to change or supplement the rule, which specifies the 

conditions under which performance testing is to be conducted. The performance testing 

conditions for process vents are described in §63.11945(b) as either maximum representative 

operating conditions for continuous venting or within the range of the maximum or minimum 

representative operating conditions that results in the highest emissions for batch venting, and 

those conditions for process wastewater are described in §63.11980(a)(1) as worst case operating 

conditions; the rule does not require performance testing during periods of startup or shutdown. 

Our approach to determining that standards should apply at all times, including periods of startup 

and shutdown was explained in the preamble to the proposed rule. We received no additional 

information indicating that conditions during startup and shutdown warrant different emissions 

limitations. In addition, Form F of the August 21, 2009 section 114 survey requested information 

from all PVC companies regarding startup, shutdown, and malfunction events. Only one 

respondent indicated that an emission limit was exceeded during a startup or shutdown period or 

a malfunction event but did not provide emission information or quantification for the 

exceedance that could be used to set separate standards for periods of startup and shutdown. We 

believe that the variability incorporated into the process vent emission limit calculation for each 

subcategory sufficiently allows for periods of concentration spiking even if they were to occur 

during periods of startup. Finally with regard to malfunctions, as explained in the preamble to the 

proposed rule, 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. 

Comment 24.2: Two commenters (0146, 0153) were particularly concerned about the 

SSM issue and its relationship to compliance using THC CEMS. The commenters (0146, 0153) 
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stated that compliance determination while using THC CEMS should not include SSM events. 

The commenters (0146, 0153) added that with the emission limits based on stack test data which 

did not include SSM events, it is not appropriate to include these periods when demonstrating 

compliance. The commenters (0146, 0153) contended that EPA must include provisions in the 

final rule to accommodate readings from continuous THC CEMS during SSM events for 

purposes of demonstrating compliance. 

Three commenters (0144, 0146, 0153) stated that a work practice standard for THC 

emissions during SSM events is appropriate. The commenters (0144, 0146, 0153) stated that it is 

nearly impossible to evaluate short term and widely varying SSM emission spikes on a consistent 

basis and it is impractical to incorporate SSM events into testing. One commenter (0153) stated 

that facilities that have two thermal oxidizers venting to one stack may have significantly more 

THC variations due to startups, shutdowns, and load shift events; therefore, these situations need 

to be properly accounted for in the final rule. The commenters (0144, 0146, 0153) added that 

elements of a work practice standard could include requirements to manage these events by 

operating the oxidizers according to manufacturer‘s recommendations, using internal procedures 

to minimize these SSM periods, conducting annual burner tune-ups, and monitoring oxygen 

levels. Furthermore, the commenters (0144, 0146, 0153) stated that in the recently promulgated 

Boiler MACT, EPA removed the numerical emission limits from the affected sources during 

startups and shutdowns, and replaced them with work practices. The commenters (0144, 0146, 

0153) respectfully requested that EPA be consistent with other MACT standards in applying 

work practice standards for affected sources during startup and shutdown periods in lieu of 

numerical emission limits. 

Two commenters (0146, 0153) suggested using a 99.9% UPL to calculate the THC 

numerical limits to include more variability for SSM periods. This would be similar to the Boiler 

MACT treatment for highly variable CO levels.

Response to comment 24.2: We disagree with the commenters, and the rule remains 

unchanged. We note that the final rule does not require THC CEMS. PVC facilities have the 

option of demonstrating continuous compliance using CPMS or THC CEMS. As discussed in the 

preamble to the proposed rule, we 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. With regard to startups and shutdowns, no information was provided to justify 

separate emission limitations for startups or shutdowns. Further, the commenters have not 
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provided information to support that the criteria in section 112(h) for setting a work practice 

standard have been satisfied. Pursuant to section 112(h), EPA may set a work practice standard 

if it is not feasible to prescribe or enforce an emission standard. Section 112 (h) (2) provides that 

such a finding must be based on a determination that ―a hazardous air pollutant or pollutants 

cannot be emitted through a conveyance designed and constructed to emit or capture such 

pollutant, or that any requirement for, or use of, such a conveyance would be inconsistent with 

any Federal, State or local law‖ or ―the application of measurement methodology to a particular 

class of sources is not practicable due to technological and economic limitations.‖ With regard 

to startups and shutdowns, no information was provided to justify separate emission limitations 

for startups or shutdowns. We note that source owners or operators who install CEMS or other 

continuous monitoring devices are required to operate them at all times. We believe that it is 

important to collect data during all process operating periods including periods of startup and 

shutdown and malfunction events. To the extent a CEMS records an exceedance during a period 

of startup or shutdown or a malfunction, and the owner or operator believes the measurement 

was in error, the owner or operator can demonstrate using any available information that the 

source complied with the standard notwithstanding the CEMS measurement showing an 

exceedance. In any event, the commenters have not provided support for their assertions that it 

would be ―nearly impossible‖ to evaluate variable emissions concentrations during such periods 

of startup and shutdown or malfunction. While direct measurement of some factors may or may 

not take place during these periods, we are not persuaded that source owners or operators would 

be left with no means whatsoever to determine whether they remained in compliance during a 

period of startup, shutdown or malfunction. Source owner or operators may use other available 

means (including engineering judgment) or information to demonstrate that the source complied 

with the standard. 

We disagree with the commenters who suggest using a 99.9, instead of 99, percent UPL 

for THC limits. Note that a 99 percent UPL represents the value which one could expect the 

mean of a future 30-run compliance test from the best performing 5 sources to fall below with 99 

percent confidence; a 99.9 percent UPL would represent the value which one would expect the 

mean of a future 30-run compliance test from the best performing 5 sources to fall below with 

99.9 percent confidence. With regard to the commenters‘ reference to variability approach 

adopted in another MACT rule, the EPA must select the approach most appropriate considering 
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the data set available to the agency for the particular emission source within the source category 

being regulated.

Comment 24.3: One commenter (0141) asserted that since the 1970s, when EPA began 

promulgating emission standards under the CAA‘s New Source Performance Standards (NSPS) 

program, it determined that the standards did not apply during periods of startup, shutdown and 

malfunction (SSM). The commenter (0141) stated that the agency recognized that the 

technologies used to meet the NSPS often ―do not reach optimum operating efficiency for some 

time,‖ and that there is a ―statistical probability of infrequent, unavoidable mechanical failures‖ 

that can make it impossible for a source to meet the NSPS during a malfunction. [37 FR at 17214 

(proposed Aug. 25, 1972).] Instead, the commenter (0141) contended that sources are required to 

follow ―good air pollution control practice for minimizing emissions‖ during periods of SSM, a 

standard that more accurately reflects the unique and unanticipated problems presented by 

diverse pieces of equipment during these events. The commenter (0141) added that as is well 

known, EPA used the NSPS program as a model for setting section 112 MACT standards in the 

early 1990s. The commenter (0141) stated that at the time, EPA stated, with no equivocation, 

that "it is technically impossible to properly operate" some required pollution control techniques 

during "unpredicted and reasonably unavoidable failures of air pollution control systems." To 

address the simple and unavoidable fact that even MACT has limitations, the commenter (0141) 

stated that EPA exempted sources from having to meet the emission standards required to be met 

during normal operations and imposed a ―general duty‖ on sources to minimize any excess 

emissions during periods of SSM. The commenter (0141) continued that in this PVC rulemaking, 

EPA proposes that the strict emission limits it has established for normal operations apply at all 

times, including periods of malfunction. The commenter (0141) stated that EPA reasons that it 

does not have to account for malfunctions in establishing emissions standards that must be met at 

all times because ―applying the concept of ―best performing‖ to a source that is malfunctioning 

presents significant difficulties.‖ 76 Fed. Reg. at 29556. The commenter (0141) added that while 

it is true that sources want to avoid malfunctions, since they can result in lost time, lost money, 

and potential harm to human health and the environment, EPA‘s simplistic declaration ignores 

the fact that all control technologies have inherent limitations and that despite best efforts, 

sources may experience a malfunction. The commenter (0141 contended that EPA proposes to 

reverse a position the Agency has held for decades, without justification. The commenter (0141) 
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stated that if normal operation standards are to apply at all times, EPA must consider emissions 

experienced by best performing sources during a malfunction and adjust the standards 

accordingly. Alternatively, the commenter (0141) stated that EPA must promulgate a different 

standard under Section 112 to apply during a malfunction event. The commenter (0141) stated 

that EPA may promulgate a work practice standard under section 112(h). The commenter (0141) 

agreed that it would be ―impracticable‖ to take malfunctions into account in setting CAA section 

112(d) standards for PVC production. The commenter (0141) added that it is often impossible to 

gather emission data during malfunctions. The commenter (0141) stated that there are work 

practices presently being used by sources – such as regular maintenance of equipment and 

monitoring operating parameters to avoid a possible malfunction and stopping or cutting back 

the process accordingly – that represent today‘s best practices to minimize excess emissions 

during a malfunction. The commenter (0141) stated that while the specific work practices 

employed by sources will depend on facility-specific issues, such as process design, pollution 

control train, and other factors, they are nonetheless how best performing sources would 

minimize excess emissions during a malfunction.

Response to comment 24.3: EPA has provided a detailed justification for its approach to 

malfunctions in the preamble to the proposed rule, and in the preamble to this final rule. As we 

explained, we recognize that even equipment that is properly designed and maintained can fail 

and that such failure can cause an exceedance of the relevant emission standard. We are 

including an affirmative defense in the final rule as we have in other recent section 112 rules so 

as to balance the tension, inherent in many types of air regulation, to ensure adequate compliance 

while simultaneously recognizing that despite the most diligent of efforts, emission limits may be 

exceeded under circumstances beyond the control of the source. Mont. Sulphur & Chem. Co. v. 

United States EPA, 2012 U.S. App. LEXIS 1056 (Jan 19, 2012) (rejecting argument that reliance 

on the affirmative defense was not adequate). EPA must establish emission standards that ―limit 

the quantity, rate, or concentration of emissions of air pollutants on a continuous basis.‖ 42 

U.S.C. § 7602(k)(defining ―emission limitation and emission standard‖). See generally Sierra 

Club v. EPA, 551 F.3d 1019, 1021 (D.C. Cir. 2008) (emissions limitations under CAA section 

112 must both continuously apply and meet section 112‘s minimum stringency requirements, 

even during periods of startup, shutdown and malfunction). Thus, we are required to ensure that 

section 112 emissions limitations are continuous. As EPA explained in those preambles, the 

EPA has determined that CAA section 112 does not require that emissions that occur during 
24-111

periods of malfunction be factored into development of CAA section 112 standards. As the EPA 

further explained, 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. Setting work practice standards under section 112 

presents the same issues as setting numerical emission limits given the varied nature of 

malfunctions. Thus EPA does not agree with commenter‘s suggestion that EPA apply work 

practices for malfunction events. Moreover, the Federal Register notice cited by commenters is 

four decades old and does not reflect subsequent amendments to the Clean Air Act and court 

decisions such as Sierra Club v. EPA. In any event, the Federal Register notice merely stated 

EPA‘s preference at that time for adopting regulations in order to formalize an approach to 

excess emissions caused by malfunctions. EPA explained its view that such an approach was 

preferable to an informal enforcement discretion approach for the following reasons: ―First, the 

existence of a formal process better informs the public of the policy and factual issues which will 

underlie enforcement of the standards. Second, affected industries which are making good-faith 

efforts to meet the standards will on the whole welcome a regularized means of informing the 

Agency in detail of the circumstances surrounding unavoidable emission excesses. Third, the 

Agency expects to benefit substantially from the information it will gain about the operation of 

the processes in question, for both future enforcement and standard setting.‖ 37 Fed. Reg. 17214, 

17214-15 (Aug. 25, 1972). The affirmative defense is not an informal enforcement discretion 

approach of the type that EPA rejected in 1972 and provides the benefits associated with the 

formalized approach that EPA identified in its 1972 proposal. See Mont. Sulphur & Chem. Co. v. 

United States EPA, 2012 U.S. App. LEXIS 1056 (5th Cir. Jan 19, 2012)(in rejecting industry 

argument that reliance on the affirmative defense was not adequate, court stated ―[h]owever, 

here the EPA does not rely on enforcement discretion alone, but specifically promulgates an 

affirmative defense in the FIP, which clearly defines the requirements to avoid penalties.‖).

Comment 24.4: One commenter (0151) argued that EPA did not take all data into 

consideration. The commenter (0151) noted that he has incomplete data which were obtained 

while beginning to bring his greenfield plant on line. The commenter (0151) stated that the data 

is for copolymer blending PVC resin, homopolymer blending resin, and dispersion resin and was 

provided in a separate attachment. He also noted the data values are above the current proposed 
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standards. The commenter (0151) added that EPA should consider this information when 

evaluating the need for further subcategorization, revisions to the proposed stripped resin limits, 

and evaluations of emission limits that apply at all times, including periods of initial startup.

Response to comment 24.4: We note that the data submitted were incomplete. The data 

also do not represent normal operation or operation during typical startup and shutdown 

activities, as it was collected during the beginning of a greenfield facility coming on line where 

processes are being run for the first time. Consequently, the data were not used in the MACT 

floor analysis. We evaluated the commenter‘s data and compared the data to the final limits for 

stripped resins. The data provided by the commenter show that the values during startup are 

below or within a very small percentage of the final stripped resin limits for the three 

subcategories mentioned such that the limits should be achievable at all times and separate 

standards are not warranted.

25.0 STATUTORY AUTHORITY

Comment 25.1: One commenter (0157) contended that Section 112(d)(2) of the CAA 

dictates that EPA must consider cost when setting a new standard. The commenter further 

contended that the cost of the proposed rule is very high.

Response to comment 25.1: Section 112(d)(2)-(3) of the Clean Air Act allows cost to be 

considered only when analyzing options more stringent than the MACT floor level of control. 

This analysis was conducted for the proposed and final rules. The discussion of the beyond-thefloor analysis is presented in section V.I of the preamble to the final PVC rules.

Comment 25.2: One commenter (0150) contended that Section 112(d)(6) of the CAA 

does not refer to the pre-1990 rules being vacated and replaced by the proposed rule. The 

commenter referred to EPA‘s claim that their issuing new PVC rules in response to the vacatur 

of its previous unlawful ones is fulfilling EPA‘s obligation under 112(d)(6). The commenter 

(0150) explained that Section 112(d)(6), addresses the review and revision of existing §112(d) 

rules, and that because EPA‘s previous §112(d) rules were vacated, the rules EPA now proposes 

are not revisions but replacements for rules that, because of their illegality and vacatur, were 

void ab initio. The commenter (0150) added that although pre-1990 rules for PVC plants 
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remained in effect following vacatur, those were not the §112(d) rules to which §112(d)(6) 

refers.

Response to comment 25.2: The commenter has misinterpreted the discussion of our

statutory authority. Under CAA section 112(d)(6), we are required to ―review, and revise as 

necessary (taking into account developments in practices, processes, and control technologies), 

emission standards promulgated under this section no less often than every 8 years.‖ In this 

rulemaking, we are fulfilling our obligation under CAA section 112(d)(6) to review and revise, 

as necessary, the PVC production area source standards, 40 CFR part 63, subpart DDDDDD, 

which were not vacated.

 

26.0 SUBCATEGORIES

See Table 2-2 in this document for cross-references in the preamble to the final PVC 

rules that discuss subcategories

27.0 VARIABILITY

Comment 27.1: One commenter (PH-H-0002) stated that the agency‘s selection of 

emission points and evaluation of HAPs moves in the right direction. The commenter (PH-H0002) recommended that more consideration be given to the variety of emissions from a wide 

array of products that the industry manufactures. The commenter (PH-H-0002) supported the 

selection of HAPs. Each resin can have a unique HAP profile and that should be taken into 

consideration. 

Response to comment 27.1: We acknowledge the commenter‘s support of the regulated 

pollutants. Selection of regulated pollutants is discussed in detail in preamble Section V.C. 

Preamble Section V.D. also discusses revisions to subcategorization since proposal which 

addresses the commenter‘s concern on variety of emissions from a wide array of products. 

Comment 27.2: One commenter (PH-BR-0009) encouraged EPA to examine the 

processes and look at the opportunities for flexibility and variability, because there are 

sometimes differences in operations that can actually achieve an environmental benefit. There 
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are differences in operations; and by allowing some flexibility, you may actually be able to 

improve the emissions' reduction. The commenter (PH-BR-0009) supported the use of maximum 

achievable control technology. The commenter (PH-BR-0009) stated that technology-forcing 

standards will improve emissions and present them with a more competitive environment, 

especially if those standards are uniformly administered. The commenter (PH-BR-0009) stated 

that as a result of competing in a world market, their products have to conform, not only to 

standards here, but to also satisfy the requirements of our competitors.

Response to comment 27.2: See preamble Section V.F.5. for discussion on Emission 

Source Requirements applicable to resin stripping. In this preamble section, we discuss how 

additional flexibility is being provided by no longer requiring sources to comply with operating 

limits and conduct continuous parametric monitoring, and instead assuring compliance by 

requiring resin sampling. We acknowledge the commenter‘s support of our calculation of the 

MACT floor limikts, and refer to preamble Section V.E.2 for further discussion on changes in 

our database and the MACT floor emission limits since proposal.

Comment 27.3: One commenter (0146) stated that the agency has sought to incorporate 

variability in several of its rulemakings, but the only case to uphold an EPA variability analysis,

coincidentally, involved the PVC MACT rule initially promulgated in 2002, which was vacated 

and remanded on other grounds by Mossville Envt‘l Action Now v. EPA, 370 F.3d 1232 (D.C. 

Cir. 2004). The commenter (0146) contended that it is important to note that the agency argued 

to the court that: in this case, determining the best five sources was impossible. The commenter 

(0146) added that this is because of the great variability in RVCM emissions, and the fact that 

that variability is a result of the type of resin being produced, not the technology or processes 

applied to control emission. The commenter (0146) stated that according to EPA, there can even 

be great variability in RVCM emission at the same PVC plant, which would obviously employ 

the same technology and processes on a day-to-day basis, if that plant produces a variety of 

resins. The commenter (0146) added that with comparisons between plants impossible, and 

emission variations not related to technological performance, EPA claims it was unable to select 

the best five sources. Therefore, after considering other alternatives, the commenter (0146) 

claimed that EPA determined that since all twenty-eight PVC plants were subject to the part 61 

NESHAP, those standards estimated the best five performing sources. [Mossville Envt‘l Action 

Now v. EPA, 370 F.3d 1232, 1240 (D.C. Cir. 2004) (internal citations omitted)] The commenter 
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(0146) concluded that these considerations remain true today, and despite the agency‘s best 

efforts, it is simply not possible to fit PVC homopolymers and copolymers into the commodity 

chemical paradigm of a simple and uniform product recipe process. 

Response to comment 27.3: See preamble Sections V.D. and V.E.2. for discussion on the 

topics presented in this comment, including subcategorization based on resin types and 

variability. Section V.E.2. contains discussion on revisions to EPA‘s database and MACT floor 

calculations that address variability concerns. Section V.D. discusses revisions to 

subcategorization since proposal, including separate subcategories for homopolymers and 

copolymers, with additional subdivisions for homopolymer resins. 

Comment 27.4: One commenter (0146) supported the agency‘s efforts to account for 

variability in setting MACT floor limits, and in particular, use of the UPL for doing so. The 

commenter (0146) stated the agency notes in the preamble to the proposed rule ―[w]e account for 

variability of the best-controlled source in setting floors, not only because variability is an 

element of performance, but because it is reasonable to assess best performance over time.‖ [76 

FR 29544.] It is axiomatic that the Act requires facilities to comply 100% of the time with 

emissions limits that are based on the average level actually achieved by the five best performing

facilities. The commenter (0146) added that no process is without variability, however, and the 

data used to determine the MACT compliance levels is only a snapshot in time, so there must be 

some way to account for variations in the process, products, etc. 

Response to comment 27.4: We acknowledge the commenter‘s support of the MACT 

floor determination, and refer to further discussion of the MACT floor calculation in preamble 

Section V.E.2.

Comment 27.5: One commenter (0146) stated that EPA should apply a compliance 

averaging factor of 12 to properly estimate the future variability of monthly resin stripping limit 

for TOHAP. The commenter (0146) stated that both the mass and concentration databases used 

by EPA to develop stripped resin limits for HAPs were populated with daily averages from each 

facility. The commenter (0146) stated that compliance requires that a 24-hour average composite 

sample from each stripping column, or from each group of strippers processing the same resin 

type, be obtained each month. The commenter (0146) added that since compliance is based on 

24-hour composite samples (daily averages) and the database is populated with daily averages, 
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there is no opportunity for averaging and the correct factor for m is 1. However, the commenter 

(0146) stated, after the first 13 months, compliance must be demonstrated based on a 12-month 

rolling average concentration, calculated as the average of the 12 most recent 24-hour arithmetic 

average concentrations. The commenter (0146) stated that because the limit is then based on an 

average of 12 daily averages, the correct factor for m becomes 12; EPA set the number of future 

observations for the compliance average, the variable ―m,‖ at 30. The commenter (0146) stated 

that this suggests that 30 samples will be used to meet the 12-month rolling average, when in fact 

the average includes only 12 samples. The commenter (0146) concluded that the correct m factor 

for use in this case is 12.

Response to comment 27.5: See preamble Section V.E.2. for discussion of MACT floor 

revisions, noting in particular revisions to the approach for stripped resins. Note especially that in 

the final rule we removed the 12-month rolling average compliance requirement. In the final 

rule, compliance with the total non-vinyl chloride organic HAP limit for stripped resin is based 

on a 24-hour composite sample taken once per month and in the UPL calculation we used an m 

value of 1.

Comment 27.6: Several commenters (0134, 0144, 0146) argued that EPA should apply a 

UPL of 99.9% to properly estimate the future variability of daily resin stripping limits for vinyl 

chloride, rather than the proposed 99% UPL. One commenter (0146) contended that agency‘s 

UPL analysis was performed on a data set consisting of a daily average. The commenter (0146) 

stated that these readings are to be assessed against a compliance frequency that also requires a 

daily average. The commenter (0146) added that according to the agency‘s background 

documents, a 99% UPL means that ―one can be 99 percent confident that the reported level will 

fall below a MACT floor emission limit calculated using a UPL.‖ [Docket Document No. EPAHQ-OAR-2002-0037-100, at 4] The commenter (0146) concluded that it follows that a facility 

that is statistically able to meet a daily MACT floor emission limit 99 percent of the time will be 

out of compliance once per every 100 samples. The commenter (0146) added that put another 

way, each of the five best performing facilities whose data was used to establish the MACT 

floor, would be expected to be out of compliance once every 100 days, or multiple times per 

year. The commenter (0146) provided a chart on page 35 of their comments that summarizes 

vinyl chloride limits for suspension resin developed using four years of Method 107 compliance 

data; the chart shows that application of the 99% percentile does not accurately demonstrate 
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emissions levels continuously achieved by the top performers. The commenter (0146) stated that 

further analysis of the data proves that on 52 days, members of the top 5 would be unable to meet 

the limit; in other words, on average, a top-performing site would be out of compliance 2.6 days 

per year. The commenter (0146) argued that use of a 99% UPL does not comport with the D.C. 

Circuit‘s charge that the best performing facility must meet the limit ―every day and under all 

operating conditions.‖ [PVC MACT Case, 370 F.3d at 1242] The commenter (0146) contended 

that direct application of the 99.9th percentile to the four year database be used to calculate the 

daily vinyl chloride emission limit. One commenter (0144) noted that in recent proposed MACT 

standards like the Boiler MACT, EPA has used a 99.9% UPL to establish the corresponding 

MACT limit in order to duly account for the data variability. The commenter (0144) stated that 

since the PVC manufacturers of suspension resins have traditionally made a wide variety of 

recipes with varying vinyl and HAP content, EPA should expand the confidence interval to 

99.9% instead of the 99% currently used in the MACT floor UPL analysis to account for 

variability in a manner consistent with other recent MACT standards

Response to comment 27.6: See preamble Section V.E.2. for discussion of MACT floor 

revisions, noting in particular revisions to the approach for stripped resins that address this 

comment. Note especially that in the final rule we used the 99.9th percentile to determine 

variability because the 4-year vinyl chloride emission data set for stripped resin was sufficiently 

large such that a UPL calculation was not appropriate.

28.0 CROSS REFERENCES AND CITATIONS

Comment 28.1: One commenter (0146) provided a summary of citation and cross 

reference errors in Table 10 of the rule (Refer to Table 10 on page 11 of the comment letter).

Response to comment 28.1: We thank the commenters for their input. The final rule 

incorporates commenter‘s edits and changes to citations and cross-references where appropriate.

Comment 28.2: One commenter (0142) recommended revising section 63.11890(d)(6)(ii) 

for clarity. The commenter (0142) pointed out that, as written, this paragraph would seem to 

impose a reporting requirement that EPA likely did not intend. The commenter (0142) indicated 

that, taken literally, the paragraph seems to be saying that one would have a deviation from the 

PVC MACT standard any time there is a failure to comply with ―any‖ term in the facility 
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operating permit, even if the permit condition has nothing to do with PVC MACT. The 

commenter (0142) recommended that, to correct this issue, section 63.11890(d)(6)(ii) read as 

follows: ―(ii) Any term or condition relating to compliance with this subpart that is included in 

the operating permit for any affected source required to obtain such a permit.‖

Response to comment 28.2: We agree with the commenter‘s suggestion. It is not our

intent for non-compliance with permit conditions other than those associated with the final PVC 

rules to trigger violations of the PVC MACT standards. We have revised the final rule based on 

the commenter‘s suggestion.

Comment 28.3: Two commenters (0118, 0152) requested an extension to the comment 

period for the proposed rule. The commenters (0118, 0152) presented various reasons for this 

request, including, among others, the limited number of industry experts available to review the 

proposed rule and the number of supporting documents associated with the proposal. One 

commenter (0118) stated that the industry‘s review of the rule was hampered by missing 

information and late submissions to the docket. Specifically, the commenter (0118) stated that 

six technical analysis spreadsheets used for floor and beyond the floor calculations, were 

released late, depriving commenters of almost two weeks time to review the information. The 

commenters (0118) further contended that in other instances, not all of the steps or data used for 

specific MACT floor calculations were disclosed in the available background documents, 

making it difficult to respond to the appropriateness of a floor calculation. 

Response to comment 28.3: We granted an extension of the comment period for two

weeks to afford additional time for review of the additional data that were added to the docket.

29.0 DOCKET

Comment 29.1: One commenter (0118) argued that the docket contains little record of 

EPA communications with stakeholders. The commenter (0118) argued that due to the litigation 

in Mossville Environmental Action Now v. EPA, there were likely multiple communications that 

could be relevant to commenters, and thus the agency should submit all unprotected documents 

and communications to the docket. In particular, the commenter 0118) identified one email 

document not included in the docket, which highlighted some of the key issues with the use of 

Method 8260B over Method 107 to sample stripped resins that are the basis of current concerns 
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about the floor calculations. Because of these omissions, the commenter (0118) contended that 

EPA should provide commenters additional time for review once these documents are submitted.

Response to comment 29.1: We disagree with the commenter‘s assertion. 

Communications with stakeholders that have occurred on this project are included in the docket. 

The specific document referenced by the commenter is included. We granted an extension of the 

comment period for two weeks to address concerns about document availability.

Comment 29.2: Two commenters (0134, 0154) contended that the proposed rule contains 

technical issues and errors. One commenter (0134) argued that these mistakes occurred due to 

the accelerated timeline of the rulemaking process, but that through subsequent data submittals 

and clarification of existing data, EPA now has the data required to fix these errors and 

redevelop emissions limitations. Another commenter (0154) pointed out a specific data error in 

the Pedricktown plant dispersion resin concentration database. They stated an example from 

12/5/09 that has the VCM concentration from the resin stripper transposed with the dried resin 

sample, and asked that these data points be removed from any calculation to avoid further error.

One commenter (0153) stated that they would be providing corrected data, and may provide 

additional data in cases where there was insufficient time to generate the data previously (even 

after the comment period closes).

Response to comment 29.2: We have reviewed all the data corrections submitted by 

industry, and where valid, we have incorporated them into the database and used them in 

subsequent analyses. See the supporting memorandum Updated Information Collection and 

Additional Data Received for the Polyvinyl Chloride and Copolymers (PVC) Production Source 

Category for a discussion of how corrected data were evaluated. 

Comment 29.3: One commenter (0153) requested that two letters discussing the 

classification of OCC‘s Deer Park facility as an area source be reviewed by EPA and added to 

the docket [(1) Letter from Barry Christensen, Oxy Vinyls, LP, to Jodi Howard, U.S. EPA, re: 

PVC and Copolymer MACT: Requirement to Provide Information Pursuant to Section 114 of the 

Clean Air Act (42 USC. §7414) (October 8, 2009); and (2) Letter from Barry Christensen, Oxy 

Vinyls, LP, to Jodi Howard, U.S. EPA, re: PVC and Copolymer MACT: Requirement to Provide 

Information Pursuant to Section 114 of the Clean Air Act (43 USC. §7414) (November 9, 

2009)].
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Response to comment 29.3: The two letters have been included in the docket.

30.0 INFORMATION GATHERING

See Table 2-2 of this document for discussion in the preamble related to information 

gathering.

31.0 STATUTORY AND EXECUTIVE ORDERS

Comment 31.1: One commenter (PH-BR-0011) pointed out that EPA must address 

Executive Order 13107, which mandates that EPA is responsible for ensuring implementation of 

ratified human rights treaties, which are applicable to environmental protection in the case of this 

proposed rule.

Response to comment 31.1: The commenter has not explained how the referenced 

Executive Order is relevant to this rulemaking or how it would lead to any modification of the 

rule.

Comment 31.2: One commenter (0126) raised a concern regarding EPA‘s 

implementation of Executive Order 12866, intended to reduce regulatory burden on business. 

The commenter (0126) argued that the proposed rule imposes a high cost with little benefit to 

public health. The commenter (0126) pointed out that while the American Chemistry Council 

(ACC) Vinyl Chloride Health Committee (VCHC) review of the proposed NESHAP for vinyl 

chloride focused on the protection of public health, EPA has produced no recent risk assessment 

related to potential impacts or benefits to public health or the effectiveness of existing 

regulations to protect public health from vinyl chloride emissions. The commenter (0126) 

expressed concern that EPA‘s proposal was, rather, based on current emissions data and 

modeling for storage vessels, equipment leaks, heat exchange systems, process vents, residual 

vinyl chloride in stripped resins, and wastewater.

The commenter (0126) noted that while the docket for this proposal contains an 

economic impact analysis, it also notes the absence of a recent risk assessment or any 

information related to potential impacts or benefits to public health. The commenter (0126) 
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stated that EPA produced no information on the effectiveness of existing regulations in 

protecting public health from vinyl chloride emissions.

Response to comment 31.2: As required by EO 12866, we prepared an analysis of the 

potential costs and emissions impacts associated with the rule, which is available in the docket. 

We have also concluded that preparation for a risk assessment is not necessary for this rule.

Comment 31.3: Two commenters (PH-BR-0004, PH-BR-0010) contended that EPA 

needs to more effectively address the issue of environmental justice raised by Executive Order 

12898. The commenters (PH-BR-0004, PH-BR-0010) expressed concern that EPA‘s 

methodology for the proposed rule does not adequately protect public health, and that EPA

should establish maximum reductions for each HAP emitted by the PVC industry to protect 

public health. One commenter (PH-BR-0010) further argued that, to protect public health, EPA 

needs to establish ―emission limits for each of the known and probable carcinogen hazardous air 

pollutants emitted by the PVC production process.‖ The commenter PH-BR-0010) argued that, 

under the executive order, EPA needs to evaluate and control the many accidental releases of 

HAPs to protect human health.

Response to comment 31.3: This rule meets the technology-based requirements of section 

112 (d)(2) and (5) of the CAA, which base control requirements on what is achieved by the bestperforming sources. After industries have the opportunity to comply with these final rules, the 

agency will conduct a review to determine if there are unacceptable adverse health risks 

associated with the remaining emissions. At that time we will take appropriate action to address 

any unacceptable health risks. With regard to accidental releases of HAPs to protect human 

health, we have addressed this issue in part by eliminating exemptions for pollutants emitted 

during startup, shutdown and malfunction events, and sources exceeding their emission limits 

during these events must submit deviation reports and may be subject to enforcement action. In 

addition, the accidental release program under section 112 (r) of the Clean Air Act requires 

owners and operators of stationary sources to identify hazards, and prevent and minimize the 

effects of accidental releases wherever extremely hazardous substances are present at their 

facility. This program is maintained by the states.

Comment 31.4: The commenters (PH-BR-0004, PH-BR-0010) contended that EPA 

should be addressing the environmental justice issues of a state like Louisiana or a small 
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African-American city like Mossville that is disproportionately exposed to HAPs from the PVC 

industry. One commenter (PH-BR-0010) provided details about Mossville, such as the fact that it 

is surrounded by 14 facilities including the largest concentration of vinyl manufacturers in the U. 

S., as well as the fact that residents‘ blood levels of dioxin are three times higher than 

background blood levels in the United States. The commenter(PH-BR-0010) referred to a study 

that has linked the particular dioxin compounds found in residents‘ blood with those emitted by 

the vinyl manufacturers. The commenter (PH-BR-0010) argued that EPA‘s methodology of 

―aggregation‖ in justifying its proposal under Executive Order 12898 is an attempt to obscure the 

fact that individual communities like Mossville should be protected under the Executive Order. 

The commenter had never seen the proposed ―aggregation‖ approach to addressing Executive 

Order 12898.

Response to comment 31.4: This national rule is being adopted to meet the technologybased requirements of section 112(d)(2), which requires that emissions be controlled to levels 

achieved by the best-performing sources in the category. As such, we believe that significant 

health protection is being accorded by the final rule. To the extent that commenters believe that 

there are threats posed by emissions from collections of different sources in any particular 

community, we encourage communities to work directly with their local and state governmental 

agencies to address their concerns.

32.0 NOTIFICATIONS, RECORDKEEPING, AND REPORTS

Comment 32.1: Two commenters (0142, 0153) stated that the certification statement is 

more detailed than necessary. The commenters (0142 and 0153) stated that rather than having 

seven individual certification statements, one general statement is appropriate. One commenter 

(0153) suggested, ―I hereby certify that the information given in this report, based on information 

and belief formed after reasonable inquiry is true, accurate, and complete‖ and the other 

commenter (0142) suggested ―Any application form, report, or compliance certification 

submitted pursuant to these regulations shall contain certification by a responsible official of 

truth, accuracy, and completeness. The commenter (0142 stated that this certification and any 

other certification required under this part shall state that, based on information and belief 

formed after reasonable inquiry, the statements and information in the document are true, 

accurate, and complete.‖
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Response to comment 32.1: The Agency has established the elements needed for the 

compliance certification through previous experience implementing the section 112(d) 

provisions. We believe that providing the seven individual statements in a checklist type fashion 

ensure ease of review and completeness for both EPA and the regulated community that each 

element is there and has been certified. 

Comment 32.2: One commenter (0142) suggested the contents of the Notification of 

Compliance status need not include information already submitted in test plans and test reports. 

The commenter agreed that performance test results and operating parameters need to be 

included in the Notification, but to require a facility to include performance test records with the 

Notification of Compliance Status is duplicative. This information is already required to be 

submitted in the test plan, test report, or EPA‘s WebFIRE database. The commenter cited rule 

language; §63.11985(a)(5) requires the inclusion of ―...one test report for each test method used 

for each process vent.‖ The commenter requested that EPA update §63.11985 to require 

submitting a summary of test results rather than requiring the submittal of the test report again. 

One commenter (0142) stated the batch precompliance report is not necessary as the 

information is similar to that included in the Notification of compliance status. To avoid 

duplication, the commenter suggested it is only necessary to include information related to 

Engineering assessments with the Notification of compliance status as required by § 63.11985 

(a)(5)(ii)(c). The commenter (0142) requested that §63.11985 be updated by deleting paragraph 

(c)(2), the batch precompliance report, and the reference to the Batch precompliance report in 

§63.11950(i). 

Response to comment 32.2: We disagree with the commenters‘ assertion that submitting 

test reports as a part of the Notification of Compliance Status report is duplicative. The test 

reports will contain information, such as calibration records and raw data sheets for field 

sampling that would not be included with the test results and test plans but are necessary for our 

review. Furthermore, reports for test methods that are compatible must be submitted 

electronically through the Electronic Reporting Tool (ERT). 

The batch precompliance report is different from the test reports required by the 

Notification of Compliance status report because it is required prior to conducting any tests. A 

facility must develop a report that will describe test conditions and other information that is used 
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to establish operating limits for all batch operations. The batch operations must then operate in 

accordance with these established limits.

Comment 32.3: One commenter (0142) suggested that Table 5 should be updated to show 

that §63.10(e)(2) does not apply. The commenter (0142) pointed out that Table 5 indicates that 

§63.10(e)(2)(i) applies, but that §63.10(e)(2)(i) is for reporting the results of a CMS performance 

evaluation as required under §63.8(e), and the table indicates that the provisions of §63.8(e) 

pertaining to the corresponding performance evaluation do not apply. The commenter (0142) 

concluded that, since the CMS performance test does not apply, the reporting of results must not 

apply either.

Response to comment 32.3 At proposal 63.8(e) was incorrectly not included in the 

General Provisions table (table 5 in the proposed rule). For the final rule, we have added the 

citation back into the General Provisions table (now Table 4 in the final rule). Consequently, we 

are maintaining the requirement to comply with 63.10(e)(2).

Comment 32.4: One commenter (0142) contended that EPA‘s proposed requirement to 

submit copies of inspection records with the semiannual compliance reports is unreasonable. 

EPA proposed that inspection reports be included with required semiannual excess emissions and 

continuous monitoring system performance reports in §63.11985(b). The commenter (0142) 

continued that the rule also addressed reporting overlap with Title V reports in §63.11985(b)(10). 

The commenter (0142) stated that any excess emission or continuous monitoring system event 

would be reported as a deviation in a Title V report and per §63.11985(b)(10) would not need to 

be reported in duplicate in a semiannual compliance report required by §63.10(e)(3). The 

commenter (0142) noted that Title V also requires annual certification of compliance by the 

responsible corporate official making the inclusion of records as a demonstration of compliance 

unnecessary. One commenter (0142) supported the proposal that information reported in the 

Title V semiannual reports not be duplicated in compliance reports required by this rule; 

§63.11985(c)(10).

Response 32.4: We disagree that the requirement is unreasonable. Inspection reports are 

required to be submitted when a deviation has occurred to provide us with the details of the 

deviation. 
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Comment 32.5: One commenter (0142) noted the proposed rule requires reporting of the 

same information regarding process changes in two different reports. The commenter (0142) 

stated that the provisions specified in 40 CFR 63.11985 of the proposed rule require that process 

changes be included with the compliance report. The commenter (0142) added that this 

requirement includes submitting changes in information previously submitted. The commenter 

(0142) noted that the notification requirements in §63.9 (as referenced in Table 5 of the proposed 

rule) also require submitting a report of any changes to previously submitted information. The 

commenter (0142) recommended removing the requirement in §63.9(j) of the General Provisions 

by updating Table 5 of the proposed rule to indicate that these requirements do not apply. 

Response to comment 32.5: We agree with the commenter that since information 

regarding process changes is required under §63.11985(b)(4)(iii) compliance with §63.9(j) is 

duplicative and unnecessary. The final rule has been updated to reflect this change.

Comment 32.6: Two commenters (0142, 0146) opposed the requirement in section 

63.11985(c)(1) that an affected source would need to provide EPA with 30 days advance notice 

of any inspection required for equipment leaks, heat exchangers, and closed vent systems. The 

commenters (0142, 0146) pointed out that inspections occur continuously at facilities and to the 

extent that inspections are ―scheduled,‖ the schedule is generally expressed as a range of days to 

allow personnel to assure the process is running in a normal, safe and orderly manner prior to the 

start of the inspection. The commenters (0142, 0146) requested that EPA remove this 

notification requirement for the equipment leak, heat exchange system, and closed vent 

provisions in section 63.11915 by removing the references to sections 63.11915, 63.11920, and 

63.11930 because inspections are conducted on such a frequency (potentially multiple times 

during a single day) that notification is overly burdensome on EPA and on the regulated 

community. They (0142, 0146) requested that in the case EPA does not choose to eliminate these 

section references, EPA provide clarification of the specific inspection requirements in these 

three sections for which EPA needs to be notified.

Response to comment 32.6: We agree with the commenters that the 30 day advance 

notification is not appropriate for equipment leaks, heat exchangers, and closed vent systems as 

these equipment are monitored frequently as part of leak detection and repair programs. The final 

rule was revised accordingly. The final rule maintains the 30 day notice for storage vessels, 

similar to the requirement in other storage vessel standards, such as subpart WW. For storage 
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vessels, inspections are not as frequent as for the other emission sources and they can be 

scheduled allowing EPA a 30 day advance notice.

Comment 32.7: One commenter (0153) stated that a great deal of the reporting involves 

various forms of notifications of leaks and releases. The commenter (0153) stated that the PVC 

industry already has extensive reporting of any unpermitted release of vinyl chloride greater than 

1 pound which already requires reporting in less than 24 hours and duplicates the compliance 

reporting required in much of Section (b) of this proposed rule. The commenter (0153) added 

that Title V deviation reporting already requires reporting of anything that constitutes a 

deviation. The commenter (0153) added that all of the inspections required by this rule require 

some sort of notification to the regulating agency. However, the commenter (0153) stated that 

neither state or local agencies nor regulated entities have the necessary resources to respond to 

these duplicative reporting and notification requirements. The commenter (0153) contended that 

this was an ideal opportunity for the agency to compare these various reporting requirements and 

simplify them so that uniformity exists and duplication is eliminated. The commenter (0153) 

suggested a detailed comparison of the reporting that is required by the VCM NESHAPS, versus 

this proposed rule, Title V reporting requirements, the applicable parts of the HON, and the NRC 

release reporting requirements.

Response to comment 32.7: The final rule does require deviations to be reported. 

However, §63.11985(b)(10) addresses what a facility is required to do where an overlap with 

Title V reports exists. It states, ―information required by this subpart, which is submitted with a 

Title V period report, does not need to be included in a subsequent compliance report required by 

this subpart or subpart referenced in the compliance report required by this subpart.‖

The title V report must be referenced in the compliance report required by this subpart.

Comment 32.8: One commenter (0153) stated that many of the requirements that are 

cross referenced to various sections of the HON rules are not clear. The commenter (0153) noted 

that the Other Control Device reporting section references 40 CFR 63.146 and says they must 

include any applicable information required by this section of the HON rules. The commenter 

(0153) stated that this section of the HON rule refers to part 138 and 139 requirements. The 

commenter (0153) contended that it is nearly impossible to figure out and be certain of what 

sections of the HON rule apply to PVC plants. The commenter (0153) recommended that a table, 
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similar to Table 5, cross referencing the specific sections that apply in the PVC MACT rule 

should be supplied by EPA and would be a great help to the regulated facilities. The commenter 

(0153) requested that one specific question needing clarification is whether a design evaluation is 

needed for wastewater strippers; more explanation of that requirement is needed in the preamble 

and cost estimates, if it is required.

Response to comment 32.8: The requirements for wastewater to comply with the Table 9 

HAP listed in the HON have been removed from the final rule.

Comment 32.9: Two commenters (0121, PH-BR-0010) contended that additional records 

are necessary. One commenter (0121) stated that in addition to the recordkeeping requirements 

in 40 CFR part 63 subpart UU, the proposed rule be revised such that the source shall maintain 

records of the following: (a) the concentration and emission rate at the time that the leak is 

detected and (b) the stream composition of the stream where a leak has been detected. One 

commenter (PH-BR-0010) noted those requirements for the discharges in the proposed rule must 

be extended to violations associated with bypasses, pressure vessels and closed vent systems in 

vacuum service. The commenter (PH-BR-0010) stated that these records and reports are critical 

to determine emission concentrations and to determine the extent of impacts due to the emissions 

and measures that should be taken to prevent the reoccurrence of similar types of events. The 

commenter (PH-BR-0010) added that these records are also critical to providing information to 

the fence line communities.

Response to comment 32.9: The emissions resulting from leaking equipment are required 

to be reported in the annual Title V report. Each facility has to characterize their streams and 

keep records of the emission profiles as specified in the final rule. We are requiring 

recordkeeping under 40 CFR part 63, subpart UU and we believe that these requirements are 

sufficient to determine compliance with the work practices set forth under this rule. In the final 

rule, any discharges directly to the atmosphere from closed vent systems in vacuum service, 

pressure vessel closure devices, and bypasses (e.g. diverting a vent stream in HAP service away 

from the control device) are violations and must be reported as deviations in the semi-annual 

compliance report. 

Comment 32.10: One commenter (0153) stated that §63.11985 (a)(7)(ii) indicates that 

sources must provide results of initial testing including annual average concentrations of VCM 
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and annual average flow rate and concentration of total HAP listed on Table 9 of subpart G, and 

that §63.11985 (a)(7)(iii) indicates sources must provide analytical backup information for Table 

9 of subpart G. The commenter (0153) argued that both of these requests are confusing and do 

not relate to what is required by the rule section dealing with initial and continuous requirements 

for stripped resin in Section 63.11960.

Response to comment 32.10: These requirements are no longer in the final rule.

33.0 MISCELLANEOUS

Comment 33.1: One commenter (0153) stated that engineering judgment must be applied 

to interpret survey and test data. 

Response to comment 33.1: We have evaluated the available data using engineering and 

professional judgment to the best of our ability in formulating this action.

Comment 33.2: One commenter (PH-BR-0009) encouraged EPA to visit facilities to help 

determine the most reasonable rules and regulations for operation. 

Response to comment 33.2: We thank the commenters for their suggestion. We have

conducted many site visits and collected information in support of the final rules.

Comment 33.3: One commenter (0144) submitted a correction of information submitted 

for LDAR MACT Floor. The commenter (0144) stated that indication that compliance had been 

achieved with 40 CFR part 63 subpart UU program at the Freeport site was erroneous, and the 

site was instead following 40 CFR part 61 subpart V. The commenter (0144) added that based on 

the correction, the commenter (0144) requested that cost and HAP reduction aspects of the 

established MACT floor be revised, in addition to information contained in Table 6-2 of the 

docketed file EPA-HQ-OAR-2002-0037-0102.

Response to comment 33.3: The commenter‘s corrections were included in the database, 

and the MACT floor determination was revised accordingly. See the preamble for the final rules 

for a discussion of the revised MACT floor analysis and documented in the technical 

memorandum, Revised MACT Analysis for the Polyvinyl Chloride and Copolymers (PVC) 

Production Source Category, which is available in the docket.
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Comment 33.4: One commenter (0153) supported the recognition in sections 

63.11890(c)(1) and (7) that monitors must be allowed some downtime for maintenance and 

repairs, whether scheduled or not. If the monitors are well operated and maintained, quality 

assurance activities and repairs should not constitute deviations.

Response to comment 33.4: We thank the commenter for their support.

Comment 33.5: One commenter (0153) requested flexibility in the final rule for 

determining operating parameter deviations. Proposed section 63.11890(d)(1) indicates that any 

exceedance of an operating parameter constitutes a deviation. The commenter argued that, from 

a practical and environmental standpoint, treating one exceedance of an operating parameter as a 

deviation is fundamentally wrong. The commenter (0153) pointed out that control equipment 

often has several operating parameters that can indicate proper operation, and if one of the 

monitors becomes inoperative, it does not necessarily indicate that excess emissions have 

occurred. The commenter (0153) requested that EPA include in the final rule a provision that 

allows an operator to demonstrate that no excess emissions have occurred by relying on the other 

monitoring parameters of operational performance even if one parametric monitor or emission 

monitoring device is not functioning as designed. The commenter (0153) provided an example: if 

a scrubber pH monitor is under repair, a site should be able to use manual readings to verify 

proper operation without incurring reportable deviations or an automatic presumption of an 

emissions violation. The commenter (0153) added that this revision is necessary because in some 

states, any deviation results in an automatic penalty assessment.

Response to comment 33.5: While we agree with the commenter that a deviation does not 

necessarily constitute a violation, we disagree with the commenter's assertion that the rule needs 

additional flexibility regarding an operating parameter deviation. As the rule allows owners and 

operators the ability to request and, upon approval, use alternative monitoring approaches and 

alternative parameters (see section 63.11985(c)(5) and (6)), an owner or operator who is 

concerned about the ability of his equipment to provide continuous monitoring can already 

submit a request to rely on an alternative monitoring approach or parameter in the event his 

equipment failed to operate properly.