NATIONAL EMISSIONS STANDARDS FOR HAZARDOUS AIR POLLUTANTS:  SECONDARY LEAD SMELTERS

                   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

                              DRAFT  -  11-4-2011

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

Nathan Topham
U.S. Environmental Protection Agency
OAQPS/Sector Policies and Programs Division
Metals and Inorganic Chemicals Group (D243-02)
Research Triangle Park, North Carolina 27711

Email<EMAIL_ADDRESS>                               TABLE OF CONTENTS

Section	Page No.

1.0	INTRODUCTION	7
2.0	LIST OF COMMENTERS	7
3.0	SUMMARY OF PUBLIC COMMENTS	3
3.1	Emissions Limits and Guidelines	3
3.1.1	Statutory Basis	3
3.1.2	Fugitive Emissions Limits	13
a.	General	13
b.	Ambient Monitoring Requirements	20
c.	Rule Clarifications	21
3.1.3	Stack Emissions Limits	23
a.	Lead and Other Metal HAP	23
b.	Total Hydrocarbons (THC) and Dioxins and Furans (D/F)	40
c.	Mercury	46
3.2	Risk Assessment	47
3.2.1	Risk Assessment Methodology	47
3.2.2	Emissions Used	89
3.3	Baseline Emissions Estimates	91
3.3.1	Fugitive Emissions Estimates	91
3.3.2	Stack Emissions Estimates	93
3.4	Compliance Timeline	94
3.5	Performance Testing	99
3.5.1	Testing Frequency	99
3.5.2	Continuous Emissions Monitoring Systems (CEMS)	99
3.5.3	Bag Leak Detection Systems (BLDS)	103
3.6	Typographical Corrections	104
3.7	SSM and Affirmative Defense	104
3.8	Request for Comment Period Extension	118
3.9	Miscellaneous	118

List of Acronyms and Abbreviations

Acronyms
ABR
Association of Battery Recyclers
ATSDR
Agency for Toxic Substances and Disease Registry
BLDS
Bag Leak Detection System
CAA
Clean Air Act
CEMS
Continuous Emissions Monitoring System
CERCLA
Comprehensive Environmental Response, Compensation, and Liability Act of 1980
CL
Confidence Limit
CSEFH
Child-Specific Exposure Factors Handbook
CTE
Central Tendency Exposure
D/F
Dioxins and Furans
EFH
Exposure Factors Handbook
EPA
U. S. Environmental Protection Agency
FR
Federal Register
GACT
Generally Available Control Technology
HAP
Hazardous Air Pollutant
HEM
Human Exposure Model
HEPA
High Efficiency Particulate Air Filter
HI
Hazard Index
HON
Hazardous Organic NESHAP
HQ
Hazard Quotient
IRIS
Integrated Risk Information System
LOAEL
Lowest Observable Adverse Effect Level
MACT
Maximum Achievable Control Technology
MEI
Maximum Exposed Individual
MIR
Maximum Individual Risk
NAAQS
National Ambient Air Quality Standards
NEI
National Emissions Inventory
NESHAP
National Emission Standards for Hazardous Air Pollutants
NOAEL
No Observable Adverse Effect Level
OAQPS
Office of Air Quality Planning and Standards
ODW
Office of Drinking Water
OHEA
Office of Health and Environmental Assessment
PB-HAP
Persistent Bioaccumulative Hazardous Air Pollutant
PSD
Prevention of Significant Deterioration
PTFE
polytetrafluoroethylene
RCRA
Resource Conservation and Recovery Act
REL
Recommended Exposure Limit
REL
Recommended Exposure Limit
RfC
Reference Concentrations
RME
Reasonable Maximum Exposure
RQ
Reportable Quantity (CERCLA)
RTR
Risk and Technology Review
SCAQMD
South Coast Air Quality Management District
SIC
Standard Industrial Classification
SIP
State Implementation Plan
SOP
Standard Operating Procedure
SSM
Startup, Shutdown, and Malfunction
TEF
Toxic Equivalency Factor
THC
Total Hydrocarbon
TOSHI
Target Organ specific Hazard Index
TRI
Toxic Release Inventory
UPL
Upper Predictive Limit
URE
Unit Risk Exposure
WESP
Wet Electrostatic Precipitator
WHO
World Health Organization

INTRODUCTION
      On May 19, 2011, EPA proposed revisions to the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Secondary Lead Smelters. Some significant comments and responses appear in the preamble to the final rule. This document contains summaries of the public comments that the EPA received on the proposed standards that are not summarized and addressed in the preamble to the final rule. 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-2011-0344.
LIST OF COMMENTERS
      The EPA received 30 comment letters on the proposed NESHAP for secondary lead smelters before the comment period closed on July 25, 2011. All comments are contained in Docket EPA-HQ-OAR-2011-0344. The commenter, affiliation, and item number in Docket EPA-HQ-OAR-2011-0344 is listed in Table 2-1.

Table 2-1. Public Comments Received by July 25, 2011 for National Emissions Standards for Hazardous Air Pollutants (NESHAP): Secondary Lead Smelters, Proposed Rule Docket EPA EPA-HQ-OAR-2011-0344

                                   Docket ID

                                 Commenter ID
                                     Code

Commenter and Affiliation
                          EPA-HQ-OAR-2011-0344-0069.1
                                      69
Robert Steinwurtzel, Attorney, Baker Hostetler on behalf of the Association of Battery Recyclers
                          EPA-HQ-OAR-2011-0344-0070.1
                                      70
Robert Steinwurtzel, Attorney, Baker Hostetler on behalf of the Association of Battery Recyclers
                           EPA-HQ-OAR-2011-0344-0071
                                      71
Dennis Lane,  Attorney, Stinson Morrison Hecker LLP on behalf of Doe Run Resources Corporation
                           EPA-HQ-OAR-2011-0344-0072
                                      72
Frederick A. Ganster, Director, Environmental Health and Safety, Exide Technologies
                           EPA-HQ-OAR-2011-0344-0073
                                      73
Michael Carr, Vice President, Johnson Controls Battery Group, Inc.
                          EPA-HQ-OAR-2011-0344-0074.1
                                      74
Robert Steinwurtzel, Attorney, Baker Hostetler on behalf of the Association of Battery Recyclers
                           EPA-HQ-OAR-2011-0344-0075
                                      75
Michael Carr, Vice President, Johnson Controls Battery Group, Inc.
                           EPA-HQ-OAR-2011-0344-0076
                                      76
Robert Steinwurtzel, Attorney, Baker Hostetler on behalf of the Association of Battery Recyclers
                          EPA-HQ-OAR-2011-0344-0078.1
                                      78
Kerry Russell, Attorney, Russell and Rodriguez on behalf of the City of Frisco, Texas
                          EPA-HQ-OAR-2011-0344-0079.1
                                      79
John Cooper, President, Cooper Environmental Services
                           EPA-HQ-OAR-2011-0344-0080
                                      80
James Kavanaugh, Director, Air Pollution Control Program, Missouri Department of Natural Resources
                          EPA-HQ-OAR-2011-0344-0081.1
                                      81
John Cooper, President, Cooper Environmental Services
                           EPA-HQ-OAR-2011-0344-0082
                                      82
Jerry Campbell, Director, Air Management Division, Environmental Protection Commission of Hillsborough County, Tampa, FL
                           EPA-HQ-OAR-2011-0344-0083
                                      83
Anonymous
                           EPA-HQ-OAR-2011-0344-0084
                                      84
John Cooper, President, Cooper Environmental Services
                           EPA-HQ-OAR-2011-0344-0085
                                      85
Krag Petterson, Pall Corporation
                           EPA-HQ-OAR-2011-0344-0086
                                      86
G. Vinson Hellwig and Robert Colby, Co-Chairs, National Association of Clean Air Agencies Air Toxics Committee
                          EPA-HQ-OAR-2011-0344-0087.1
                                      87
Timothy J. LaFond, Environmental Committee Chairman, Battery Council International
                          EPA-HQ-OAR-2011-0344-0088.1
                                      88
Billy Nichols, Principal Engineer, URS Corporation on behalf of Sanders Lead Company
                          EPA-HQ-OAR-2011-0344-0089.1
                                      89
Michael Carr, Vice President, Johnson Controls Battery Group, Inc.;  John Tapper, Chief Operating Officer, Gopher Resources, EnviroFocus Technologies; Dean A. Rossi, Vice President  -  Global EHS, Exide Technologies; Richard Leiby, Vice President, Metals Operations, East Penn Manufacturing; N. Kenneth Campbell, Executive Vice President, Sanders Lead Company
                          EPA-HQ-OAR-2011-0344-0090.1
                                      90
Michael Carr, Vice President, Johnson Controls Battery Group, Inc.
                          EPA-HQ-OAR-2011-0344-0091.1
                                      91
Dennis Lane,  Attorney, Stinson Morrison Hecker LLP on behalf of Doe Run Resources Corporation
                          EPA-HQ-OAR-2011-0344-0092.1
                                      92
J. Jared Snyder, Assistant Commissioner for Air Resources, Climate Change and Energy, New York Department of Environmental Conservation
                          EPA-HQ-OAR-2011-0344-0093.1
                                      93
Richard Leiby, Vice President, Metals Operations, East Penn Manufacturing
                          EPA-HQ-OAR-2011-0344-0094.1
                                      94
Dean A. Rossi, Vice President  -  Global EHS, Exide Technologies
                          EPA-HQ-OAR-2011-0344-0095.1
                                      95
Homer P. Hine, Vice President, RSR Corporation
                          EPA-HQ-OAR-2011-0344-0096.3
                                      96
Robert Steinwurtzel and Mark DeLaquil, Attorneys, Baker Hostetler on behalf of the Association of Battery Recyclers
                         EPA-HQ-OAR-2011-0344-0096-A5
                               N/A (Attachment)
Robert Steinwurtzel and Mark DeLaquil, Attorneys, Baker Hostetler on behalf of the Association of Battery Recyclers Attachment A
                         EPA-HQ-OAR-2011-0344-0096-A6
                               N/A (Attachment)
Robert Steinwurtzel and Mark DeLaquil, Attorneys, Baker Hostetler on behalf of the Association of Battery Recyclers Attachment B
                         EPA-HQ-OAR-2011-0344-0096-A7
                               N/A (Attachment)
Robert Steinwurtzel and Mark DeLaquil, Attorneys, Baker Hostetler on behalf of the Association of Battery Recyclers Attachment C
                         EPA-HQ-OAR-2011-0344-0096-A8
                               N/A (Attachment)
Robert Steinwurtzel and Mark DeLaquil, Attorneys, Baker Hostetler on behalf of the Association of Battery Recyclers Attachment D
                         EPA-HQ-OAR-2011-0344-0096-A9
                               N/A (Attachment)
Robert Steinwurtzel and Mark DeLaquil, Attorneys, Baker Hostetler on behalf of the Association of Battery Recyclers Attachment E
                         EPA-HQ-OAR-2011-0344-0096-A10
                               N/A (Attachment)
Robert Steinwurtzel and Mark DeLaquil, Attorneys, Baker Hostetler on behalf of the Association of Battery Recyclers Attachment F
                         EPA-HQ-OAR-2011-0344-0096-A11
                               N/A (Attachment)
Robert Steinwurtzel and Mark DeLaquil, Attorneys, Baker Hostetler on behalf of the Association of Battery Recyclers Attachment G
                         EPA-HQ-OAR-2011-0344-0096-A12
                               N/A (Attachment)
Robert Steinwurtzel and Mark DeLaquil, Attorneys, Baker Hostetler on behalf of the Association of Battery Recyclers Attachment H
                         EPA-HQ-OAR-2011-0344-0097-A2
                                      97
Myra C. Reece, Chief, Bureau of Air Quality, South Carolina Department of Health and Environmental Control
                           EPA-HQ-OAR-2011-0344-0098
                                      98
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club
                         EPA-HQ-OAR-2011-0344-0099-A1
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0099-A2
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0099-A3
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0099-A4
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0099-A5
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0099-A6
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0099-A7
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0099-A8
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0099-A9
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0099-A10
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0100-A1
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0100-A2
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0100-A3
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0100-A4
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0100-A5
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0100-A6
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0100-A7
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0100-A8
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0100-A9
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0101-A1
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0101-A2
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0101-A3
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0101-A4
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0101-A5
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0102-A1
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0102-A2
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0102-A3
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0102-A4
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0102-A5
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0102-A6
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0103-A1
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                         EPA-HQ-OAR-2011-0344-0103-A2
                               N/A (Attachment)
Earthjustice, on behalf of California Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment
                           EPA-HQ-OAR-2011-0344-0111
                                      111
Matt Todd, Chair, The Residual Risk Coalition
                           EPA-HQ-OAR-2011-0344-0120
                                      120
Krag Petterson, Pall Corporation
                           EPA-HQ-OAR-2011-0344-0127
                                      127
Robert Steinwurtzel, Attorney, Baker Hostetler on behalf of the Association of Battery Recyclers
                           EPA-HQ-OAR-2011-0344-0130
                                      130
Robert Steinwurtzel, Attorney, Baker Hostetler on behalf of the Association of Battery Recyclers

SUMMARY OF PUBLIC COMMENTS
      Comments received on the proposed amendments to the secondary lead smelting rule that were not presented in the preamble to the final rule are summarized in the following sections along with EPA's responses.  In many instances, commenters provided additional documents as background information or otherwise in support of their comments. Those documents are contained in the docket to this rulemaking but are not summarized here.
Emissions Limits and Guidelines
      Statutory Basis
      Comment:  Comments received from the Secondary Lead Smelting industry (Commenters 90, 91, 94, 96) challenged what they characterize as the dual regulation under both the National Ambient Air Quality Standards (NAAQS) and the NESHAP programs.  These commenters made the following claims:
      The provisions of CAA §§ 112(b)(2) and 112 (b)(7) preclude EPA from setting emission standards or work practices under CAA § 112 for lead and other criteria pollutants.  EPA has listed both lead and its compounds as a criteria pollutant under CAA § 108(a), for which NAAQS have been promulgated at all relevant times.  EPA has already embarked on a path to reduce the health risks of exceeding the lead NAAQS through CAA §109 regulation and the statute precludes EPA from seeking to reduce the same risk via a CAA § 112 route.
      Further risk reduction through revision of the NESHAP is not required taking into account the emissions controls required to achieve the NAAQS, therefore a NESHAP revision is not required to protect public health or prevent environmental effects, and so is not authorized.
      Emissions will be reduced completely independent of the NESHAP because states must assemble SIPs without being able to wait for NESHAP completion.
      The two standards would be effectively duplicative, and revising the NESHAP to address risk is not required if EPA considers emissions controls required through implementation of the NAAQS.  The NAAQS already ensures that risks are addressed with an adequate margin of safety.
      Congress gave elemental lead special treatment in the Clean Air Act, providing a separate and unique prohibition against EPA listing elemental lead as a hazardous air pollutant under this subsection.  EPA is effectively regulating under 112 (f)(2) based on the toxicity of elemental lead, and this violates section 112 (b)(7) of the Act which prohibits listing of elemental lead as a HAP.  EPA is not permitted to count lead atoms from lead compounds and create a NESHAP that governs total lead in all chemical forms, but may establish standards for individual and unique lead compounds when appropriate based on toxicity or other factors.
      The proposed rule negates the SIP process for lead NAAQS attainment.  The proposed MACT rule accelerates Lead NAAQS attainment without any explanation of why acceleration is appropriate.

      Response: With respect to the comment that the EPA may not address lead compounds in section 112 (d) rules, the EPA notes that the EPA issued MACT rules regulating lead compounds in 1997 and no commenter objected to the approach.  EPA did not reopen the issue in this rule, or otherwise reconsider its long-established approach.  Consequently, EPA believes this issue to have been resolved long since. See Medical Waste inst. v. EPA, 645 F. 3d 420, 427 (D.C. Cir. 2011) and Portland Cement Ass'n v. EPA, No. 10-1358 (D.C. Cir. 2011) (slip op. at 17) (both holding that issues not raised when NESHAP is first promulgated may not be raised when those standards are revised).
      If any substantive response is considered to be necessary, the lead emitted from secondary lead smelting is lead compounds, a HAP listed by Congress in section 112 (b)(1)  The commenter did not provide data to refute this.   Nor has the EPA listed elemental lead as a HAP either explicitly or effectively. The EPA does not accept the commenter's argument that the EPA is implicitly regulating elemental lead under section 112 (f) standards by evaluating risk from exposure to lead compounds emitted by secondary lead facilities. The EPA's obligation under section 112 (f) is to evaluate whether unacceptable risk to human health or the environment from a source category's emissions remains after the EPA has promulgated section 112 (d) MACT standards for the source category and to amend those standards if unacceptable risk remains.  The standards thus build off of the section 112 (d) standards, and as just noted, it has long been resolved that those standards apply to lead compounds and not to elemental lead.  The commenter also invokes section 112 (f)(6) which states that "[i]n establishing standards for the control of unique chemical substances under this subsection without CAS numbers [of which "lead compounds" are an example], the Administrator shall establish such standards with respect to the health and environmental effects of the substances actually emitted by sources and direct transformation byproducts of such emissions...".  The EPA has done so here, evaluating risks with respect to actual emissions of lead compounds from secondary lead sources.  See 76 FR at 29035.
      In addition, the rule regulates other HAP metals for which lead serves as a surrogate.  See National Lime Ass'n  v. EPA, 233 F. 3d 625, 637-39 (D.C. Cir. 2000) (permissible for EPA to use a criteria pollutant as a surrogate for HAP). The commenter does not question the use of lead as a surrogate for other metal HAP, and did not question use of that approach in the 1997 NESHAP. Consequently, the standards for lead also rest on this independent justification.
      Other commenters noted that the lead NAAQS applies to "lead and its compounds", referring to section 50.12 (a) of the EPA's regulations. The commenter further notes that under the NAAQS, the EPA measures and hence regulates lead by summing the elemental lead present in lead and its compounds, and placing a limit on the ambient level of total lead in any form separate from other elements to which it may be chemically bound. The commenter argues that in light of this, regulation of lead compounds in this rule is necessarily in tension with implementation of the NAAQS. Noting the prohibition on listing "elemental lead" as a hazardous air pollutant in section 112 (b)(7), the commenter argues that the section 112 (b)(7) prevents the EPA from regulating lead identically under section 112 as under the NAAQS, and thus that "the EPA may not regulate lead compounds in an identical manner as the NAAQS program - by placing limits on lead in all of its chemical forms, whether bound to other atoms or not."  The commenter views Congressional intent as assuring that section 112 rules do not interfere with implementation of the lead NAAQS.	The EPA does not view section 112 (b)(1), (b)(2), and (b)(7) as unambiguously mandating the result the commenter seeks. Congress listed lead compounds as a HAP in section 112 (b)(1), meaning that the EPA is compelled to issue section 112 standards for that HAP. Section 112 (b)(2) forbids the EPA from adding to the list of HAP any pollutant listed under section 108 (a) (i.e. a criteria pollutant), but the EPA has not added such a pollutant to the HAP list. Nor has the EPA listed "elemental lead" as a hazardous air pollutant, in violation of section 112 (b)(7). Regulating lead compounds is simply not the same thing as listing elemental lead (and even the commenter notes that the term "elemental lead" is ambiguous in this context.)  Finally, the EPA does not accept that the commenter's ultimate point  that Congress intended that section 112 standards for lead compounds must be tailored in such a way as not to interfere with NAAQS implementation "because the NAAQS already ensures that risks are addressed with an adequate margin of safety". First, as noted in other comment responses in section 3.2 of this document and in section V.A of the preamble to the final rule, the legal standard under section 112 (f) is not the same as under sections  109 (b) and (d), so a NAAQS cannot be presumed to provide an acceptable level of risk with an ample margin of safety (and the EPA has therefore provided an independent justification here for use of the lead primary NAAQS as a measure of risk acceptability, and conducted an independent ample margin of safety analysis). Moreover, the commenter's argument makes little sense in the context of the technology-based standards under section 112(d) where consideration of risk, and hence of the protections afforded by the lead NAAQS, are irrelevant. Ultimately, the commenter's approach would deprive the section 112 (b)(1) listing of lead compounds of meaning (given that virtually all emitted lead from industrial processes is expected to be lead compounds due to chemical reactions), and EPA thus does not accept it.
      The commenters raise a number of issues regarding the relation of this rule to the lead NAAQS. First, the fact that control of emissions from secondary lead sources has positive implications for attaining the lead NAAQS does not mean that EPA is impermissibly controlling emissions of a criteria pollutant.  As just stated, section 112 (b) makes clear that regulating lead compounds under section 112 standards is not only permissible but mandated.  The fact that such controls aid in attaining a NAAQS is a collateral benefit of the rule, not a prohibition on adopting it.  (Similarly, this rule may aid in attaining the PM NAAQS but this doesn't mean that the rule impermissibly regulates emissions of PM.)  Nor does the rule negate the section 110 SIP process whereby states develop implementation plans for attaining and maintaining the NAAQS.    That process will necessarily go forward and states may look to the emission reductions from this rule as part of the SIP process (just as emission reductions from EPA mobile source controls or controls on stationary sources can be invoked in SIPs for PM and ozone).  In this regard, EPA's discussion in the preamble of the relationship of this rule to implementation of the lead NAAQS (76 FR at 29603), which a commenter mistakenly takes as showing that this rule was adopted to assure attainment of the lead NAAQS, was intended only as a `good government' type of discussion to show that the timing of this rule could fit in with the NAAQS implementation process.  We repeat that this rule rests on the exclusive authority of sections 112 (d) and (f), and not on sections 107, 110 or any other provision applicable to NAAQS implementation.  Put another way, section 112 of the CAA explicitly requires the EPA to perform the reviews that form the basis of these rule amendments and to act in accord with the results of those reviews. The requirements of the final rule are necessary to achieve acceptable risk with an ample margin of safety and to prevent adverse environmental effects (and are also "necessary" within the meaning of section 112 (d)(6) of the Act). The measures that facilities are required to implement to achieve those requirements should also have positive effects on areas attaining and maintaining the lead NAAQS, but the standards are required and justified under section 112 (f) and (d)(6) whether or not that were the case. Ironically, the EPA could well interfere with the SIP process if it accepted the commenter's (incorrect) argument that EPA must take into account "NAAQS-mandated emissions reductions" (See EPA-HQ-OAR-2011-0344-0096, p. 31). The lead NAAQS itself does not mandate anything.  It is an air quality standard only.  States determine how to implement it.  The suggestion that EPA attribute emission reductions to the SIP process which lies within states' authority, and which has not yet occurred, therefore would be unwarranted speculation at best and impermissible interference at worst.
      In the proposed rule, the lead NAAQS, a health based standard, was used by EPA to determine whether or not there was unacceptable risk from lead compounds emitted by secondary lead smelting sources.   It is permissible for EPA to look to the lead NAAQS as a measure of acceptable risk (see responses at page 64 of this document and section V.A of the final rule preamble), and doing so does not mean that EPA is using this rule to implement the lead NAAQS.  Rather, EPA must, and has, independently justified the use of the lead primary NAAQS as a reasonable measure for ascertaining acceptability or unacceptability of emissions of lead from this source category, within the meaning of section 112 (f)(2) of the Act.  Given that modeled ambient lead concentrations resulting from emissions from the facilities in the source category were greater than the lead NAAQS, it was concluded at proposal, and for the final rule, that risk was unacceptable, and that it would continue to be unacceptable until the NAAQS was met. See 76 FR at 29054.  Once we determined a level of emissions that result in risks being acceptable, under the two-step residual risk decision process, the EPA then considered additional controls that might further reduce risk to achieve an ample margin of safety considering cost and feasibility, and determined that there were none.  We repeat that this process implements section 112 (f) of the Act, and is not part of NAAQS implementation.
      Comment: Commenter 91 stated that the use of lead concentration in air does not fit within the meaning of "emission standard" as used in CAA 112(d), (f), or (h).  The NAAQS addresses ambient air quality, not source emissions, and as such, does not limit the quantity rate or concentration of emissions from a particular source.  Ambient monitoring measures something other than emissions at and from a source, and cannot be equated with or used to determine compliance with an emission standard.
      Response: The commenters mistake the purpose of the fenceline monitoring compliance alternative in the proposed rule. The proposed rule provided that fugitive emissions would need to be addressed by work practice standards (as is allowed under section 112(h)(1)). Finally, it proposed to establish the option for a fenceline monitoring requirement to ensure that the work practice standards adequately address fugitive emissions consistent with the requirements of section 112(f) as an alternative to totally enclosing fugitive generating processes. However, the EPA is not adopting this proposed compliance option so the comment is essentially moot.
      Comment: Commenter 90 challenged the decision to establish MACT floors for reverberatory, rotary and electric furnaces not collocated with blast furnaces. In the final rule published on June 13, 1997, EPA determined that no THC limits (and thus no other organic HAP limits) would apply to theses furnace types.  Thus, EPA effectively established the MACT floor for these sources.  According to the commenter, "EPA has already established the MACT floor for D/F and THC as addressed in CAA §§112(d)(2) and (3) as it applies for reverberatory, rotary and electric arc furnaces, and no additional "setting of the floor" is possible under these sections at this time.  Commenter 96 further stated that MACT standards pursuant to section 112(d)(3) "have never been intended as having the "inexorable downward ratcheting effect.""
      Commenter 90 also stated that EPA cited an improper legal basis for setting new emission limits for THC and Dioxins and Furans. The commenter stated that "EPA may revise a prior determination only as necessary according to explicit statutory criteria... The CAA is not intended to allow the Agency to revisit previously-established MACT standards in effort to fill in the gaps."  EPA stated in the preamble to the proposed rule that "because the 1997 NESHAP did not include emissions limits, we are proposing emissions standards for dioxins and furans pursuant to CAA section 112(d)(3)."  According to the commenter,  "This explanation makes it clear that EPA is invoking 112(d)(2) and (3) directly as authority to amend Subpart X as if a MACT standard for these sources does not already exist...EPA lacks authority for setting any new standards under CAA §§112(d)(2) and(d)(3)."
      The commenter further stated that "The RTR Proposed Rule does not attempt to predicate its decision to set controls for THC and D/F (for sources other than blast furnaces), on the Court's decision in Sierra Club v EPA, 479 F.3d 875(D.C. Cir. 2007) (Brick MACT).  Having made the determination not only to rely on Sierra Club in support of the proposed rule, EPA may not change course without issuing a supplemental proposal and allowing an opportunity for public comment....EPA would have to justify why the decisions reflected in the current standards are wrong and why the new standards meet the required criteria that EPA must satisfy in issuing MACT standards under CAA 112(d)(2) and (3).  EPA has not made either showing in the RTR Proposed rule."  The commenter noted that EPA cited National Lime v. EPA, 233 F. 3d 625, 624 (DC Cir. 2000), in support of its decision to set emission standards for THC and dioxins and furans from subcategories other than blast furnaces.  The commenter points out, however, that as set forth in Sierra Club, EPA has not interpreted National Lime as requiring the Agency to set such standards.  Furthermore, National Lime does not control because the decision did not address EPA's authority to set standards pursuant to section 112(d)(6) and 112(f).  Instead, National Lime addressed what emission standards the agency should propose in a MACT rulemaking pursuant to deadlines set forth in section 112(e).
      Commenter 90 also raised the issue that challenges to the MACT standards are to be raised within 60 days of their promulgation and that facilities regulated by Subpart X have already made capital investments to meet the existing MACT standards.  EPA should justify why the decisions reflected in the current standards are wrong and why the new standards meet the criteria under CAA §§ 112(d)(2) and (3).
      Commenter 96 made a similar argument that the proposed rule lacks a sufficient legal basis to support its proposed promulgation of emission standards for dioxins and furans and THC.  According to the commenter, "Clean Air Act §§112(d)(6) allows EPA to revise only emission standards promulgated under this section" 42 U.S.C. §7412(d)(6).  EPA has not promulgated emission standards for dioxins and furans or THC (for furnaces other than blast furnaces), so it may not promulgate revised standards for these substances under that authority".
      Commenter 90 stated that the proposed rule improperly reset MACT floors pursuant to the CAA 112 (d)(6) process and that the CAA does not require EPA to recalculate MACT floors.  According to the commenter:

      The RTR Proposed Rule's basis for revising the lead emission MACT floors pursuant to CAA § 112(d)(6) is that the Agency "believe[s] that these proposed revisions, identical to those proposed under CAA section 112(f)(2), are cost effective revisions that reflect the level of control achievable in practice by a well-performing fabric filter." 76 Fed. Reg. at 29,059-60. Whether a control is cost-effective and achievable is relevant to the availability of a particular control, but does not answer the antecedent question of whether or not imposing such control is necessary to protect public health or the environment in light of other legal requirements that the CAA applies to the secondary lead smelting industry.

      Response:  In Medical Waste Institute v. EPA, 645 F. 3d 420, 425-27 (D.C. Cir. 2011), the D.C. Circuit held that EPA may permissibly amend improper MACT determinations, including amendments to  improperly promulgated floor determinations, using its authority under section 112 (d) (2) and (3).  (The lack of a remand on these issues here is a distinction without a difference.  The absence of standards for these HAP is not proper.  National Lime, 233 F. 3d at 633-34; see also Medical Waste Incinerator, 645 F. 3d at  426 (resetting MACT floor, based on post-compliance data, permissible when originally-established floor was improperly established, and permissibility of EPA's action does not turn on whether the prior standard was remanded or vacated).  The D.C. Circuit's December 9, 2011in Portland Cement Ass'n v. EPA (D.C. Cir. No. 10-1358) confirms that EPA is not constrained by section 112 (d)(6) and it may reassess its standards more often, including revising existing floors if need be. Slip op. p. 17. The commenters are thus incorrect that section 112 (d)(6) provides the exclusive authority to address THC, dioxin and mercury emissions here.  Put another way, if EPA did not adopt a proper MACT standard initially, it is not amending a MACT standard but adopting one for the first time.  That is the case here for THC (from some furnace types), dioxin and mercury emissions.  Here, EPA adopted no MACT standard at all for these HAP, an approach soundly rejected by the D.C. Circuit in National Lime, 233 F. 3d at 633-34.   Consequently, EPA is not barred from making MACT floor determinations and issuing MACT standards pursuant to section 112 (d)(2) and (3) here.
      Comment: Commenters 90 and 96 claim that the EPA's proposed regulation of lead compounds under the NESHAP program conflicts with its regulation of lead under the PSD program.  The commenters point out that that section 112(b)(6) of the CAA prescribes the regulation of pollutants listed under section 112, including lead compounds, under PSD, and that section 112(b)(7) precludes listing elemental lead under section 112.
      The commenters allege that the EPA has previously suggested in a PSD rulemaking that it counts the lead portion of lead compounds towards PSD significance levels for lead.  See 67 Fed. Reg. 80,186, 80,239 (Dec. 31, 2002).  Thus, the commenters allege that, because the EPA can disaggregate the "elemental lead" portion of lead compounds for purposes of PSD, it can also disaggregate the toxic effects of lead from lead compounds, and the commenters allege that this is required for the EPA to avoid regulating elemental lead under section 112 (f) and (d)(6) standards.  Thus, the commenters claim that there is a conflict between the proscriptions of sections 112(b)(7), and the regulation of lead compounds on the basis of their lead toxicity pursuant to sections 112.
The commenters claim that, in the alternative, if the EPA concludes that it may regulate lead compounds on the basis of their lead toxicity pursuant to section 112, then the EPA cannot consider the lead aspect of lead compounds for purposes of regulating elemental lead under PSD.  The commenters argue that, to conclude otherwise would mean that lead compounds are subject to duplicative regulation under both the NESHAP program and PSD, which the commenters claim is unlawful.
      Response: The commenters are correct in stating that section 112 (b)(7) forbids the EPA from listing elemental lead as a hazardous air pollutant and that by extension this precludes the EPA from regulating elemental lead as a HAP under section 112 (d) and (f) standards. The commenters are further correct in stating that section 112 (b)(6) prohibits the agency from subjecting hazardous air pollutants that are listed under section 112(b)(1) and (2) of the Act to PSD regulation.  However, the EPA disagrees that these provisions prevent the EPA from regulating lead compounds under section 112 (d) and (f), and disagrees that any actions taken under the PSD program are inconsistent with regulation of lead compounds in this rule.  Furthermore, to the extent that any response is deemed necessary, the EPA disagrees that any actions taken under the PSD rules with respect to elemental lead and lead compounds is inconsistent with section 112 (b)(6).
      First, as explained in the first response in this section 3.1.1, this rule (like the 1997 NESHAP) regulates lead compounds, not elemental lead.  Lead compounds are listed HAP which the EPA must regulate under section 112 (see section 112 (b)(1) item 106423), and objections to the EPA doing so are untimely by at least 14 years (the date of the initial NESHAP for this source category).
      The commenter's comparison with actions under the PSD program are misplaced. In the PSD rule, for purposes of assessing whether sources were emitting at the statutory rate thresholds or volumetric concentrations, the commenter claims that the EPA determined that the weight of elemental lead could be disaggregated from lead compounds, citing 67 Fed. Reg. at 80,329.  While the EPA did not use the term "disaggregation" in the cited rule preamble, the EPA did communicate that it counts the lead component of lead compounds in determining the mass of lead emitted from a source. Nevertheless, in relying on this EPA statement here, the commenter is comparing apples to oranges. The present rulemaking deals with issues of toxicity and risk, not weight. What is involved is not a straight-forward counting exercise but a determination of risk posed by exposure to lead compounds. It is entirely reasonable for the EPA to consider the toxicity of lead compounds based on elemental lead toxicity, and indeed, there are no suggestions on this record that there is any technical error in doing so.
      The commenter's suggestion that the EPA amend its PSD rules is well beyond the scope of this proceeding, and the EPA is not reconsidering, reexamining, reassessing, or otherwise reopening its PSD rules in any way. To the extent that any response to the comments relating to PSD is considered to be necessary, the EPA disagrees with the commenter's assertion that sections 112(b)(6) and (7) preclude the EPA from both regulating lead compounds on account of their elemental lead toxicity and considering the lead component of lead compounds when calculating levels of lead emissions for purposes of PSD.  Although section 112(b)(6) prevents the agency from subjecting hazardous air pollutants that are listed under section 112(b)(1) and (2) of the Act to PSD regulation, the EPA has interpreted  section 112(b)(6) to permit the regulation of a HAP listed in section 112 to the extent it is a constituent or precursor of a more general pollutant that is subject to PSD regulation. This interpretation was outlined in the 1991 New Source Review (NSR) Transitional Guidance, John S. Seitz (March 11, 1991), which was issued to address changes made to the new source review program in the Clean Air Act Amendments of 1990.  In that memo, the EPA explained that "[a]ny hazardous air pollutants listed in section 112(b)(1) which are regulated as constituents of a more general pollutant listed under section 108 of the Act are still subject to PSD as part of the more general pollutant."  Id. at 2.  The EPA further explained that lead compounds are subject to the exception described "[l]ead compounds are exempt from Federal PSD by Title III, but the elemental lead portion of lead compounds (as tested for in 40 CFR Part 60, Appendix A, Method 12) is still considered a criteria pollutant subject to the lead NAAQS and still regulated under PSD."  Id. at 3.
      The EPA relied on the reasoning contained in the 1991 guidance memo when it proposed to retain its interpretation of section 112 that permits the lead component of lead compounds to be subject to PSD regulation as a part of the regulation of lead generally. Prevention of Significant Deterioration (PSD) and Nonattainment New Source Review (NSR), 61 Fed. Reg. 38250, 38310 (July 23, 1996).  In the PSD rule to which the commenter cites, the EPA finalized this position:  "When any pollutant listed under section 112 of the Act is also a constituent or precursor of a more general pollutant that is regulated under section 108 of the Act, that listed pollutant may be regulated under NSR but only as part of regulation of the general pollutant."  Prevention of Significant Deterioration (PSD) and Nonattainment New Source Review (NSR): Baseline Emissions Determination, Actual-to-Future-Actual Methodology, Plantwide Applicability Limitations, Clean Units, Pollution Control Projects, 67 Fed. Reg. at 80,240 (Dec. 31, 2002).  The EPA reiterated in that final rule that it would continue to consider the lead component of lead compounds to be a constituent or precursor of lead in the atmosphere, as consistent with the 1991 guidance memo.  Thus, the EPA has consistently determined that there is no conflict between regulating lead compounds under section 112 and considering the lead component of lead compounds for purposes of PSD with respect to the lead NAAQS, so long as the lead compounds themselves are not subject to PSD regulation.
      Fugitive Emissions Limits
   a. General
      Comment: Commenter 98 stated that EPA's proposed standard for fugitive lead emissions does not meet the requirements of section 112(d)(6).  According to the commenter, "EPA must set a stronger standard for fugitive dust emissions of lead, which make up a significant amount of the lead emissions for this source category".  The commenter contends that neither proposed alternative complies with section 112(d)(6).  The alternative of total enclosures "imposes a numerical limit only on the emissions vented to a stack from the total enclosure and not for the other work practices.  This will not ensure the necessary reduction of fugitive emissions at these facilities... EPA must set a numerical limit that applies to emissions resulting from the work practice standards in addition to setting a numerical limit for emissions from total enclosure (vented to a stack).  The fugitive emissions standard for the additional work practice should be based on modeling of ambient levels achieved as a result of optimal implementation of those work practices.  This standard may not simply replicate the limit of the lead NAAQS."
      For the alternative of monitoring lead concentrations in air plus work practices, the commenter stated that "Simply replicating the lead NAAQS through monitoring... is not a valid substitute for doing an actual 112(d)(3) and 112(d)(6) analysis based on achievable emission reductions.... EPA should set a numerical limit for emissions resulting from the additional work practice standards."
      Response:  In the final rule, we have removed the proposed option for facilities to implement lead monitoring in lieu of installing total enclosures. Therefore, the final rule requires secondary lead facilities to construct total enclosures for fugitive emission sources and to conduct a list of prescribed fugitive emission control work practices. The commenter's objections to the alternative monitoring approach are thus moot.
      We disagree that the final fugitive emission standard does not meet the requirements of section 112(d)(6).  First, it is clearly permissible for EPA to set work practice standards to control fugitive emissions.   According to section 112(h) of the CAA, "...if it is not feasible in the judgment of the Administrator to prescribe or enforce an emission standard for control of a hazardous air pollutant or pollutants, the Administrator may, in lieu thereof, promulgate a design, equipment, work practice, or operational standard, or combination thereof, which in the Administrator's judgment is consistent with the provisions of subsection (d) or (f) of this section."  It is not feasible to enforce a numerical emissions standard for fugitive emissions from secondary lead smelters that are not vented to a stack since these emissions are not directly measurable (this is why they are termed `fugitive emissions').  However, we note that fugitive emissions which are enclosed, captured, and vented to a control device are subject to the numerical standard for individual stacks and are count against the facility-wide stack emission limit for lead, and thus are effectively subject to a numerical limitation.
      The commenter suggests that the standards  -  which require total enclosure of lead bearing materials  -  could be made stricter still.  We are not aware of a more effective means to control fugitive emissions than total enclosure of process areas that generate fugitive emissions and requiring that those enclosures be vented to a control device. We are also requiring work practice standards along with those enclosures that will ensure that there are no opportunities for any fugitive dust generated inside those enclosures to be carried outside. The final rule includes every work practice possible that would limit fugitive lead emissions without creating workplace safety hazards.   (After the public comment process, EPA's statement at proposal  -  "[w]e acknowledge that there may be other control measures and alternative approaches that we have not identified that are effective in reducing fugitive emissions at other facilities (76 FR at 29056/3) -- no longer holds.  After considering the public comments, we are not aware of any such measures.)
      The commenter also indicates that any work practice standards should be reinforced by some type of numeric standard tied to fenceline monitoring.  EPA is not adopting this type of provision.  The EPA evaluated available preexisting ambient monitoring data and compared the ambient concentrations with the degree of enclosure and presence of work practice standards similar to those included in this final rule. This comparison demonstrated that the measures required in this final rule will achieve reductions in ambient lead concentrations to levels below the NAAQS. See Summary of Ambient Lead Monitoring Data Around Secondary Lead Smelting Facilities, which is available in the docket (EPA-HQ-OAR-2011-0344). Monitoring in perpetuity for the NESHAP to observe this already demonstrated fact will impose burden without any further environmental benefit. The requirements in the NESHAP include measures for determining continuous compliance that are sufficient to ensure that emissions, and ambient concentrations, will remain low. The requirement to totally enclose buildings and maintain them under negative pressure with ventilation to a control device ensures that fugitive emissions will not escape buildings through doorways or other openings. Work practice standards, such as those requiring vehicle washing prior to leaving a total enclosure ensure that lead bearing dust within buildings is not inadvertently transported outside of the structure and re-entrained later. The requirements in the final rule that prevent fugitive emissions from escaping buildings in the first place make it unnecessary to include ambient monitoring.
      Section 112(h) of the CAA further states that "In the event the Administrator promulgates a design or equipment standard under this subsection, the Administrator shall include as part of such standard such requirements as will assure the proper operation and maintenance of any such element of design or equipment."  We believe that the monitoring and recordkeeping required for the work practices and the measurement of building differential pressure ensure "proper operation and maintenance" of the work practice requirements for fugitive emissions that are not vented to a stack.  Hence, the final standards for fugitive lead emissions are clearly warranted under sections 112(f) and 112(d)(6).
      We note that we did evaluate the work practices already employed by some facilities as well as South Coast Air Quality Management District (SCAQMD) rule 1420.1 and while some of the work practices adopted in this final rule are similar to some requirements of SCAQMD, that rule included a number of measures that are geared towards specific challenges posed by conditions in the Los Angeles area. For example, roof washing is required in the SCAQMD rule, and while this measure may be appropriate for the warm, dry climate in Los Angeles, it is inappropriate for areas with higher levels of precipitation (e.g. Puerto Rico) or for areas with cold climates (e.g. New York, Minnesota) where falling ice could present safety hazards for workers. The final rule includes all of the enclosure and work practice requirements for fugitive emissions that were deemed necessary to provide the public with an ample margin of safety while ensuring that those requirements do not create redundant requirements or workplace hazards.
      Comment: Several commenters (90, 96, 91, 93) suggested that EPA had not adequately explained the emissions benefits of the proposed work practice requirements, and that EPA lacks any legitimate basis for its estimate of emissions reductions that would result.  Commenter 96 stated that there was no documentation in the record explaining how EPA derived an estimate of 4.2 tons per year attributed specifically to the work practices.  The commenter notes their assumption that the underlying basis of the anticipated total aggregate fugitive emissions reduction of 9.5 tons per year is based on the emissions estimates in the RTR emissions dataset, an assumption that the commenter asserts is incorrect for two reasons.  First, EPA's methodology to calculate the 9.5 tons per year is wrong because EPA overestimated fugitive emissions for Exide Frisco whose estimates form the basis for estimated emissions from the remaining secondary lead sources.  Second, the Exide Frisco emissions estimates do not contain estimates of emissions for many of the activities that the proposed work practice requirements are aimed at addressing.
      The commenters further note that the agency does not identify which facilities undertake all the design standards and work practices.  According to the commenters, "EPA's failure to include this information in the record contravenes Clean Air Act § 307(d)."  The commenter further stated that "EPA"s failure to include this information underlying the Proposed Rule's design standards and work practices is prejudicial to the ABR because the Association cannot meaningfully comment on whether EPA has correctly described and transformed into proposed legal requirements the practices on which these proposed work practice standards are predicated."  Commenters 90 and 96 offered that "In order for the design standards and work practices to be consistent with Clean Air Act §112(d)(2), they collectively must be undertaken by, or at least consistent with, the best performing five sources in the industry."  The commenter further stated that "EPA cannot predicate a risk-based CAA 112(f) emission standard for metal HAPs on compliance with the NAAQS absent a specific factual determination by the Administrator that the designs and work practice standards collectively are necessary to meet ...public health criteria."
      EPA stated in its preamble to the proposed standards that "these controls are necessary to ensure that three-month rolling average lead concentration near the boundaries at all facilities in this source category do not exceed the lead NAAQS."  Commenters 90 and 96 commented that "This rationale is incorrect because several facilities meet the lead NAAQS at all monitors near their property boundaries without applying these measures."  The commenter provides Gopher Resources, East Penn, RSR (NY), and RSR (IN) as examples of facilities that are currently and regularly meeting the NAAQS at monitors near their boundaries without applying all the proposed work practices.  The commenter state that the facilities do NOT conduct the following proposed work practices: cleaning of pavement with a water application rate of at least 0.48 gallons/square yard, rooftop washing, and inspection of battery storage areas more frequently than once per week.
      Commenter 96 noted that although the SCAQMD issued a rule that requires sources to undertake some of the work practices proposed by EPA, "EPA did not state that it was relying on the SCAQMD rule, nor did it introduce that rule or any administrative materials underlying its consideration into the record. "  The commenter argues that introducing the record of the SCAQMD rule "would have shown that it was potentially justified only in light of the unique local concerns in that area..."  The commenter stated that "EPA has no basis for concluding that the work practices that the SCAQMD required would be effective at all outside the specific conditions in that region..."
      Commenter 90 agrees with EPA's proposed use of an SOP manual for fugitive emissions control procedures but requested that EPA reassess the overall strategy related to fugitive emissions.  The commenter "recommends that the RTR proposed rule require that each facility's SOP manual require consideration of the various work practices and total enclosure requirements...but not require implementation of specific requirements without consideration of site-specific factors...  Ambient monitoring at each facility will be the test to verify that fugitive dust control measures are effective..."   The commenter requests that EPA specifically exclude the following areas from requirements to address in an SOP manual: intact battery storage, lead ingot product handling where fugitive lead dust is not generated, handling of storm water and wastewater treatment residuals, and clean battery casing plastic handling.
      Commenter 93 stated that the work practice requirements represent a cost burden disproportionate with any perceived benefit, and are unnecessary for facilities to operate in compliance with the current lead NAAQS.  The commenter requested that the mandatory work practice requirements be removed from Subpart X.
      Response:  The technical document describing the technology review for this source category clearly described the methodology used to calculate the emissions benefits in the proposed work practice requirements. See Summary of the Technology Review for the Secondary Lead Smelting Source Category, which is available in docket ID EPA-HQ-OAR-2011-0344. We used the same methodology to calculate the emissions reductions as was used to calculate the baseline fugitive emissions for each facility.  The commenter is correct that there was a miscalculation at proposal in the baseline fugitive emissions estimates. See section V.E of the final rule preamble. We have corrected the baseline fugitive emission estimates and the subsequent emissions reductions associated with the proposed work practice. We have done additional modeling for the source category based on the updated fugitive emission estimates (reflecting slightly reduced emissions from fugitive emissions) and the conclusions remain the same as at proposal. Lead emissions still remain unacceptably high and revisions to the standard are necessary to provide acceptable risk with an ample margin of safety. See Residual Risk Assessment for the Secondary Lead Smelting Source Category, available in docket ID EPA-HQ-OAR-2011-0344. The EPA has also adjusted the emission reduction estimates resulting from the revisions to the standard. While the cost effectiveness of the metal HAP emission reductions has decreased slightly from the estimate at proposal, we believe that the revisions to the standard to address fugitive emissions are still cost effective and necessary  under section 112(d)(6).
      The commenters note that in order for the design and work practice standards to be consistent with section 112(d)(2), they must be undertaken by the best performing five sources in industry.  However, the work practices are being adopted under section 112(d)(6) (and under section 112 (f)(2), as noted in the next paragraph), not 112(d)(2). Section 112(d)(6) does not require a MACT floor-like calculation involving the best performing five sources, but rather is based on developments in control practices, processes and technologies and may reflect considerations of cost (including cost effectiveness) of adopting additional controls and non-air and energy impacts associated with additional controls.  All of the work practices included in the final rule that were not in the original NESHAP are performed at least by the well-controlled Exide Technologies facility in Vernon and Quemetco facility in City of Industry that are subject to the SCAQMD 1420.1 rule, while some of these work practices are conducted by many other facilities (e.g., pavement or groundcover of facility grounds, transport of dust in sealed containers or conveyor systems).
      The work practices are also being adopted under section 112(f)(2).  The preamble to the proposed rule clearly described that our analyses indicated that the proposed work practices were necessary to achieve lead concentrations near the boundaries of the facilities that are at, or below the lead NAAQS, a benchmark of risk acceptability in this rule. 76 FR at 29056/3. Section 112(f)(2) of the CAA also does not require a MACT floor calculation based on the performance of the top 12% of sources (or top 5 sources for a category with less than 30 facilities). In fact, if section 112 (f)(2) standards are required, the standards must result in acceptable risk  whether or not any sources in the category are currently performing at that level.
      With regard to the facilities described by the commenter as meeting the lead NAAQS without implementation of the proposed work practices and therefore should not require further control under section 112 (f) (2), we note that this rule implements section 112 (f)(2), not the lead primary NAAQS. Section 112 (f)(2) standards apply on a source category-wide basis, so the commenter's suggestion that EPA adopt facility-by-facility standards predicated on the individual area's attainment status is not legally permissible. (The work practice standards are also `necessary' under section 112 (d)(6) given these affordable and cost effective industry practices and developments.) Nevertheless, as a result of these and other comments received on the proposed rulemaking, we have removed some of the proposed specific work practices mentioned by the commenter that present safety hazards or are redundant as noted in section V.C of the final rule preamble.
      We agree that the SCAQMD rule may contain some work practices that are most effective at the two facilities in southern California. However, the final list of work practice standards will ensure that fugitive dust is not generated outside of total enclosures which are vented to control devices, thereby ensuring the public is protected from these emissions with an ample margin of safety. Each facility must also develop and submit a SOP to their local permitting authority for approval to ensure that the facility properly implements the enclosure requirements and work practice standards.
      Comment: Commenters 90 and 96 proposed regulatory language to address the specific issues identified for the alternative to total enclosures (§63.544(d)(1)  -  (d)(8)).
      Response: We thank the commenters for drafting recommended language; however, because we have removed the alternative to total enclosures, these issues are no longer relevant.
   b. Ambient Monitoring Requirements
      Comment:  The EPA requested comments on the proposed alternative requirement of ambient monitoring, including whether two monitors would be sufficient or if more monitors may be necessary.
      Commenter 98 stated that installing two monitors, with at least one located where highest air concentrations are expected, is not sufficient.  According to the commenter, the requirement "... should be strengthened to require continuous measurement from a sufficient number of monitors to capture both the dominant and intermittent wind patterns and regular verification and oversight by the permitting agency."  The commenter also suggested that a 30-day rolling average be adopted because a greater lag time exists before exceedances are identified and rectified using a three month rolling average.
      Commenter 82 stated that two monitors would be sufficient, and offered the following support and suggestions: "Our historical air monitoring record and experience in the Pb emissions from these sources illustrates the significant influence of wind speed and direction on ambient air concentrations in the surrounding community.  Therefore, we believe the placement of at least one compliance monitor at the location of expected maximum concentration impact should be based on the most recent five years of meteorological data and approved regulatory modeling.  A second compliance monitor located at or near the plant boundary is necessary to observe impacts due to seasonal changes in meteorology.  This level of monitoring would be adequate for compliance demonstration provided the monitors were located according to the Probe and Monitoring Path Siting Criteria for Ambient Air Quality Appendix E to 40 CFR Part 58."
      Commenters 90, 96, and 91 recommended that the EPA follow the NAAQS siting requirements for ambient monitors in 40 CFR Part 58.  Commenter 91 noted that, when promulgating the Lead NAAQS siting criteria, the EPA rejected selecting sites solely based on the location of maximum estimated concentration.  Instead, the EPA considered the potential for population exposure and logistical considerations as factors to consider in siting decisions and changed paragraph 4.5 of 50 C.F.R. Part 58 accordingly.  The commenter further noted that the siting criteria in the proposed rule is not consistent with the NAAQS as it does not require the placement of monitors in "ambient air" locations, but requires siting "at or near the facility boundary..."
      Response:  We have removed the lead concentration in air monitoring alternative from this rule.  Therefore, the commenter's concerns related to the fenceline monitoring requirements need not be addressed in this rulemaking.
      Comment:  Commenter 90 noted that the EPA used the terminology "continuous monitoring system" in the proposed ambient monitoring requirements.  This monitoring system is not a continuous monitoring system and the specifications for CMS in §63.8(c) would not be appropriate.
      Response:  We have removed the lead concentration in air monitoring alternative from this rule.  Therefore, the commenter's concerns related to the fenceline monitoring requirements need not be addressed in this rulemaking.
   c. Rule Clarifications
      Comment:  Two commenters (90, 96) requested a clarification that sources may switch between the two means of compliance.
      Response:  We have removed the option for facilities to monitor lead concentrations at the fenceline in lieu of totally enclosing fugitive generating processes. Therefore, this comment is no longer relevant.
      Comment:  Two commenters (90, 96) requested that the EPA clarify that its proposed alternative design standards do not preclude a regulated entity from offering alternative design standards.  According to the commenter, "EPA should include a provision... reaffirming regulated facilities' statutory right to seek approval of alternative measures that are equivalent to design standards and alternative design standards proposed by EPA."  The commenters also requested that the EPA clarify its alternative work practice equivalency requirements to provide clarity for sources that wish to exercise their statutory right under CAA 112(h)(3) to engage in equivalent alternative work practices.
      Response:  We note that the general provisions in 40 C.F.R. Part 63 Subpart A at §63.6(g) that apply to a request for approval of an alternative to a standard are specifically included in this rule as referenced in Table 1 to Subpart X. Facilities have the option to develop and submit an alternative set of fugitive emission control work practices to the Administrator for approval.  However, we note that it is the facilities' responsibility under these provisions to demonstrate to the Administrator that their proposed work practices are equivalent to those required in the final rule, and this would include being equivalent in terms of mass emission reductions.
      Comment:  Three commenters (90, 96, 94) stated that it would be inappropriate to consider the lead NAAQS as an emission standard because lead NAAQS values are affected by other sources and by background lead concentrations.  The commenters requested confirmation that monitored NAAQS exceedances would not constitute a violation of the CAA that could lead to civil or criminal liability under CAA §113.  Commenter 94 stated that it would not be appropriate to impose penalties for exceedances over 0.15 ug/m[3] since the monitored level is not isolated to emissions from the secondary lead smelter (and the ambient level is not an emissions standard)."  Commenter 96 noted that section 112(h) only allows for the EPA to promulgate a work practice, design, or equipment standard where "it is not feasible ... to prescribe or enforce an emission standard."  The commenter notes that "This provision would make no sense if design, equipment, or work practice standards were already "emission standards."
      Response:  We have removed the lead concentration in air monitoring alternative from this rule. We are requiring total enclosures rather than providing the alternative for ambient monitoring. Since we are requiring total enclosures, differential pressure monitoring to demonstrate continuous compliance with the enclosure requirement, and work practice standards to prevent fugitive emissions, ambient monitoring at the fenceline is not necessary. Ambient monitoring data is already available from NAAQS monitors near secondary lead smelters. As noted in response at page 15 above, those data show that facilities with total enclosures and work practices like the ones being promulgated in this rule achieve ambient lead concentrations well below facilities that do not have such enclosures and well below the primary NAAQS for lead (a measure of unacceptable risk here).
      Comment:  Several commenters (82, 90, 96) requested that the EPA clarify what actions facilities must undertake in the case of an exceedance of the lead NAAQS.   Commenter 82 encourages the EPA to include a requirement to fully enclose process fugitive emission sources as corrective actions or, at a minimum, require the facility to submit a corrective action plan as part of a standard operating and maintenance procedure manual under the alternative compliance option.  Other commenters suggested that the EPA require sources to report the exceedances to the relevant permitting authority so that the permitting authority can determine what additional steps may be necessary.
      Response: We have removed the lead concentration in air monitoring alternative from the final rule.  Therefore, these concerns related to the fenceline monitoring requirements need not be addressed in this rulemaking.
Stack Emissions Limits
   a. Lead and Other Metal HAP
      Comment:  Commenters 90 and 96 argue that EPA has misapplied CAA section 112(d)(6) and should not be adopting any standards pursuant to that provision.  The argument is based on the term "necessary" in CAA section 112 (d)(6).  The argument goes that CAA section 112(d)(6) standards are not "necessary" here because they are unnecessary  to protect public health and the environment.
      Response:  The EPA does not agree that determining whether standards under CAA section 112(d)(6) are "necessary" is determined exclusively by considerations of risk.    The "core requirement" of CAA section 112(d)(6) is the existence or non-existence of developments  in practices, processes, and control technologies, not a public health-based determination .  NRDC v. EPA, 529 F. 3d 1077, 1084 (D.C. Cir. 2008).  CAA section 112(d)(6)is also a continuation of the technology-based section 112 (d) standard-setting process, again indicating that the determination is not controlled exclusively by risk-based considerations.    Consequently the EPA does not believe that a CAA section 112 (d)(6) standard is "necessary" only if justifiable based on public health/risk considerations.
      The EPA further notes that this is an argument without practical consequence here, because the EPA has found that standards are warranted to prevent unacceptable risk.  Moreover, there have been developments in control technologies (e.g. improvements in baghouse design and enclosure practices) which are available at reasonable cost and cost effectiveness.  .For example, all of the lead emissions data received after proposal reinforced our conclusion that the emissions limit proposed for lead stack emissions was warranted based on demonstrated levels of performance achieved in the industry. See Development of the RTR Emissions Dataset for the Secondary Lead Smelting Source Category for a description of the updated emissions estimates and see Cost Impacts for the Secondary Lead Smelting Source Category for a description of the cost and cost effectiveness of the revisions to the rule.   Consequently, EPA does not accept the commenter's argument that standards under section 112 (d)(6) are unnecessary and further does not believe that the argument has practical significance in this rulemaking given that the section 112 (d) (2) standards for this source category do not reduce public health risk to an acceptable level with an ample margin of safety.
      Comment:  Commenter 90 stated that the EPA has provided no basis for proposing a lead stack concentration limit of 0.20 mg/dscm for all emission sources.  According to the commenter:

      EPA modeled stack and fugitive emissions of lead from facilities and compared the predicted results with the lead NAAQS.  EPA's conclusion was that lead concentrations exceeded the NAAQS and determined the risk was unacceptable.  EPA then remodeled facilities considering the reductions required by the RTR Proposed Rule.  The regulatory changes that affect emissions included reducing the stack lead concentration to 0.20 mg/dscm and reducing the fugitive emissions to account for work practices in the RTR proposed rule.  The results indicate that the facilities' predicted concentrations after implementing these changes were below the NAAQS; therefore, these changes are necessary under the residual risk review.

      The commenter first noted that there are facilities in this source category that currently comply with the NAAQS or are projected to comply in the near future without imposition of significantly reduced concentration limits for baghouses.  RSR's Middletown, NY facility currently complies with the NAAQS.  The Exide Technologies facility in Frisco, TX and the Texas Commission on Environmental Quality (TCEQ) developed an attainment demonstration for Collin County, Texas that does not require stack emissions to be reduced to 0.20 mg/dscm.  The commenter points out that at the Exide Frisco facility, in fact, the average flow-weighted concentration of lead from all modeled emission sources exceeds 0.20 mg/dscm and one source has emissions that exceed 1 mg/dscm.
      The commenter also stated that sensitivity analyses have not been conducted to determine the individual impacts of stack reductions and fugitive reductions, and that the reduction in fugitive emissions is likely sufficient to show predicted offsite lead concentrations below the NAAQS. The commenter stated that "although the impact of stack reductions on offsite sources is likely to be small relative to the contribution of fugitives, EPA artificially inflated the impact of stack emissions by running a modeling scenario at the allowable emission levels instead of the actual emission levels." The commenter requested that the EPA rerun the models using actual stack emissions to determine if fugitive emission reductions alone are sufficient to result in modeled lead concentrations below the NAAQS. The commenter also stated that in the cases that stack emissions are still determined to be relevant, the EPA should consider not only achievable reductions in emissions but also other methods that improve dispersion such as ensuring stacks are designed to minimize building downwash.
      Response:  As noted above, section 112 (f)(2) standards apply to an entire source category, but do not require every facility to pose unacceptable risk to trigger the section 112 (f)(2) standard requirement.  Just the opposite: the final sentence of section 112 (f)(2)(A) makes clear that  section 112 (f)(2) standards are triggered (for cancer risks) based on risks "to the individual most exposed to emissions from a source in the category" (emphasis added).  The standards then apply to all sources in the category or subcategory.  Moreover, the stack emission standards are performance based and do not require adoption of any particular control measure.  Thus, sources that already are emitting less than the specified level will not require further stack control.  The commenter initially notes that several facilities currently comply with the NAAQS or are projected to comply with the NAAQS in the near future whether or not EPA adopts standards for lead which are more stringent than those of the 1997 NESHAP, specifically citing RSR's Middletown, NY facility and Exide's Frisco, TX facility.  The commenter is correct that RSR's Middletown, NY facility currently reports ambient lead concentrations near the facility that are below the lead NAAQS.  However, as supported by the ICR responses available in the docket, RSR's stack emissions of lead are far below the facility-wide flow-weighted concentration limit of 0.20 mg/dscm presented in the proposed rule so this rule should not result in that source adopting further stack control for its lead compound emissions.  With regard to Exide's Frisco, TX facility, we note that the agreed order between Exide and the TCEQ in support of the SIP (available in the docket) requires Exide to replace two existing baghouses with new baghouses fitted with polytetrafluoroethylene (PTFE) membrane media and improved seating design, retrofit five other baghouses with new PTFE membrane media, and replace all the baghouse tube sheets with an improved seating design. The order also requires installation of secondary HEPA filtration on all baghouses that receive lead emissions with the exception of the furnace baghouses which are required to either install secondary HEPA filters or PTFE secondary filtration devices.
      The commenter questions evaluating potential for risk based on allowable emissions.   EPA did provide risk estimates considering MACT allowable emissions from stacks, and it is permissible and reasonable to do so.  For carcinogens, in fact, EPA is require to assess whether "standards promulgated pursuant to subsection (d)"  pose a designated measure of risk to a most exposed individual, language which clearly can be read to apply to allowable emissions (i.e. emissions allowed by the standards  -  the subject of the review).  The statutory language for non-carcinogens is less specific but still readily amenable to consideration of allowable emissions (especially given no indication that Congress intended a different approach for carcinogens and non-carcinogens).  The EPA also assessed risk considering actual emissions from stacks.   Further, the EPA disagrees with the comment that reductions in fugitive emissions are likely sufficient to show predicted offsite lead concentrations below the lead primary NAAQS. Although this may be the case for most facilities in the source category, it is not the case for all.  As noted in the preamble, there was a facility that was estimated to have lead concentrations about three times the NAAQS for lead based on actual stack emissions only. See 76 FR 29052. Thus, for this facility, reductions beyond those in fugitive emissions would clearly be needed to achieve acceptable risk from lead emissions.  Moreover, we note that controls that result in reductions in lead emissions would also decrease the emissions of other HAP metals. As a result, at some facilities we would anticipate that these controls would also result in reduced cancer and acute risk from metals.
      We have discussed the use of both allowable and actual emissions in previous actions, including the final Coke Oven Batteries residual risk rule (70 FR 19998-19999, April 15, 2005) and in the proposed and final Hazardous Organic NESHAP (HON) residual risk rules (71 FR 34428, June 14, 2006, and 71 FR 76603, December 21, 2006, respectively). In those previous actions, we noted that modeling the allowable levels of emissions (i.e., the highest emission levels that could be emitted while still complying with the NESHAP requirements) is inherently reasonable since they reflect the maximum level sources could emit and still comply with national emission standards. But we also explained that it is reasonable to consider actual emissions, where such data are available, in both steps of the risk analysis, in accordance with the Benzene NESHAP.
      Comment:  Commenter 95 stated that the proposed standard for stack emissions of metal HAP does not satisfy the CAA's risk and technology review provisions.  The commenter stated that the EPA relied on practices and technologies that are out of date.  The commenter stated that "CAA Section 112(f)(2)(A)... states that if, upon completion of the eight year review, the existing MACT standards for a carcinogenic pollutant do not reduce lifetime cancer risks to less than 1-in-1 million, then EPA must promulgate standards under section 112(f) for sources emitting that pollutant".  The commenter argues that the EPA must revise the proposed standard for lead emissions to reduce maximum lifetime cancer risk due to metal HAP emissions to below 1-in-1 million.
      Response:  As an initial matter, we disagree that the technology review relied on practices and technologies that are out of date.  Section 112(d)(6) requires the EPA to evaluate developments in practices, processes, and control technologies.  Issues of cost and technical feasibility are legitimate consideration as part of determining whether standards are "necessary" under section 112 (d)(6). Our analysis indicated that there have been developments in fabric filtration that warrant a lower lead emission standard for this source category.  The stack emissions limit for lead adopted in this final rule will achieve an estimated 8.2 tons per year of metal HAP reductions at an annualized cost of $2.7 million dollars ($0.33 million dollars per ton of HAP reduced). This limit is based on the performance of a well-operated baghouse.  Baghouses meeting this limit sometimes employ HEPA filters as a polishing measure after the primary filter. However, HEPA filters are not always feasible or necessary. These polishing filters are amenable to control of particulate from building ventilation sources that do not have extremely high temperatures or particle loading. While the lead concentrations from stacks equipped with HEPA filters were on average about 20% lower than those without, the existence of the HEPA filter was not the lone variable influencing the difference in concentration.  Other factors such as age of the primary control device, type of baghouse used, and type of process vented to the emission point likely contributed significantly to the distribution of lead concentrations from the stacks. Additionally, HEPA filters are only applicable to some sources where high exhaust temperature or high particulate loading will not interfere with the proper operation of the filter. Because of these reasons, we did not believe the dataset warranted establishing an emissions standard lower than 0.20 mg/dscm based on the use of a HEPA filter. See Summary of the Technology Review for the Secondary Lead Smelting Source Category, available in the docket.
      To achieve significant reductions beyond those possible using a well operated baghouse, we evaluated an additional polishing control device, a wet electrostatic precipitator. This technology could achieve metal HAP reductions of about 19.2 tons per year (i.e. an additional 11 tons of metal HAP), however the cost (annualized cost of $46 million dollars, $2.4 million dollars per ton of HAP reduced) would be over 15 times higher than the costs of using a well-operated baghouse. The use of a wet electrostatic precipitator would also increase electricity demand, increased emissions associated with electricity generation (with attendant carbon and NOx pollution), and additional wastewater generation.  These significantly increased costs, poor cost effectiveness, and collateral adverse energy and environmental impacts  support EPA's decision not to require further reductions under section 112 (d)(6).
       The commenter is mistaken that section 112 (f)(2) requires EPA  to reduce maximum lifetime cancer risk to below 1-in-1 million, and the D.C. Circuit has in fact rejected the commenter's argument.  Moreover, as stated in the Benzene NESHAP, in determining the need for residual risk standards, we strive to limit to no higher than approximately 1-in-10 thousand (100 in a million) the estimated cancer risk that a person living near a plant would have if he or she were exposed to the maximum pollutant concentration for 70 years and, in the ample margin  of safety decision, to protect the greatest number of persons possible to an individual lifetime risk level of no higher than approximately 1-in-1 million.  As noted in the proposal preamble, even the highest estimated cancer risk from actual emissions from this source category of 50-in-1 million is below the 100-in-1 million threshold identified in the benzene NESHAP.  See 76 FR at 29052, Table 3. We therefore determined that the inhalation risk due to actual emissions from this source category was acceptable.  See 76 FR at 29055/1.  We determined that the overall risk due to allowable emissions was, however, unacceptable, and we proposed a revised standard that would reduce the MIR due to allowable emissions to acceptable levels.  The proposed standard also reduced the MIR due to actual emissions from 50-in-1 million to 10-in-1 million.  Since the MIR estimated after the proposed controls for metal HAP emissions was above 1-in-1 million, we evaluated the need for additional controls to provide an ample margin of safety for public health taking into account cost and feasibility. See 76 FR at 29057. However, we did not identify any further feasible and cost-effective controls, and we therefore concluded that the revisions proposed under section 112(f)(2) will provide an ample margin of safety with regard to lead emissions from this source category. We remodeled the source category after the proposal to incorporate public comments regarding emissions, boundary and other information relevant to performing a risk assessment. The results estimate the same baseline inhalation cancer risks based on actual emissions (50 in a million) although the MIR facility has changed. Post-control we now estimate that MIR to be 7 in a million (i.e. slightly less than estimated risk at proposal). See EPA-HQ-OAR-2011-0344-0036 at page 36, stating the post-control cancer MIR was 10 in based on the proposal risk assessment and see Residual Risk Assessment for the Secondary Lead Smelting Source Category, which is available in EPA-HQ-OAR-2011-0344 at page 35 for the post-control risk results for the final rule. Moreover, we note that the baseline MIR due to allowable emissions remains 200 in a million and will be reduced to acceptable levels after controls. We performed an ample margin of safety analysis to determine whether additional controls are warranted considering cost and technical feasibility. We have determined that the controls required in this final rule include all of the controls that are technically and economically feasible to reduce cancer risks from fugitive emissions. This analysis resulted in some specific work practices which we proposed not being required in the final rule (e.g. roof washing). However, total enclosures are a requirement in the final rule rather than an option. This requirement, coupled with the work practices prescribed in the final rule, will prevent fugitive emissions from being generated outside of total enclosures or entrained inside enclosures and carried out. These requirements will protect the public health with an ample margin of safety.
      Comment:  Commenters 95 and 98 disagreed with the EPA's analysis regarding the WESP.  Commenter 95 stated that the EPA overstated the cost of the WESP and that the EPA should revisit the MACT floor for this industry to account for this new technology that has resulted in the RSR Corporation far out-performing every other company and facility.  Commenter 95 stated that RSR submitted cost data showing that costs are between $18 and $20 million, or a total cost to the industry of $234 to $260 million. Commenter 95 stated that the WESP cost (per ton of lead) represents 0.4 percent of the value of one ton of lead.  Commenter 98 stated that the fact that three facilities in this source category are able to install the technology shows that reductions from the technology are achievable, taking into account cost.  Commenter 98 noted that the Clean Air Act is a technology-forcing statute, not one meant to enshrine the practices already achieved by all or the vast majority of the industry.  Commenter 98 further stated that the EPA fails to provide a rational justification for not requiring emissions reductions based on the WESP technology.  The commenter notes that the non-cancer HQ that the EPA found is five times the level associated with public health concerns and that the fact that costs are "high" is not sufficient reason for the EPA not to consider how much acute or cancer risk reduction would occur if the EPA were to require further emissions reductions based on the WESP.
      Commenter 95 also stated that the WESP is a polishing unit and the EPA appears to have compared the WESP with industries where WESPs are used as primary controls.  The commenter stated that the EPA also appears to believe that RSR uses the WESP unit to treat fugitive emissions.
      Response:  First, whether or not section 112 (d)(6) is "technology forcing", the EPA retains very significant discretion in balancing relevant factors in determining whether it is "necessary" to revise the existing technology-based MACT standards.  Sierra Club v. EPA, 325 F. 3d 374, 378 (D.C. Cir. 2003). In reviewing section 112 (d) (2) standards, and determining whether to revise them is "necessary" under section 112 (d)(6), the EPA may take into consideration cost and feasibility when evaluating developments in practices, processes, and control technologies.  Indeed, it is reasonable that any such "review" consider the same factors which EPA is required to consider under section 112 (d)(2)  -  cost, non-air environmental impacts, potential impacts on energy usage among them.  The EPA determined that requiring installation of the WESP at all facilities would result in a total capital cost to the industry of approximately $400 million.  See Cost Impacts for the Secondary Lead Smelting Source Category, at page 5, available in the docket (Docket ID: EPA-HQ-OAR-2011-0344-0040). Given the amount of emissions reductions that would occur with installation of the WESP, and given that the impact of stack emissions on risk is low relative to fugitive emissions and that the emission limits in the final rule will obtain substantial reductions in HAP emissions, the EPA determined that the WESP is not a cost-effective control option and is not warranted under section 112(d)(6) or 112(f)(2). Specifically, an emissions limit based on this technology would result in annualized cost to the industry of about $46 million dollars per year with a cost effectiveness of about $2.4 million dollars per ton of HAP reduced. As noted in a previous response, this is roughly 20 times greater than the control based on performance of state-of-the-art baghouses without the following step of a WESP. We have determined that the limits included in the final rule will provide an ample margin of safety, and the additional cost to meet a limit based on WESP technology is not warranted under either statutory provision. As noted above, the energy use associated with operation of a WESP also has negative environmental implications and is another factor in EPA's decision not to adopt standards predicated on use of this technology.
      Commenter 95 asserted that RSR submitted cost data showing that total cost to the industry of installing WESPs is between $234 and $260 million rather than  $400 million as estimated by EPA at proposal. The EPA did consider the data submitted by RSR in estimating the potential cost to the industry of installing WESPs.  However, it would not be appropriate to simply assign the $18 to $20 million cost incurred by the RSR facility to each of the additional facilities, as the facilities differ significantly in several aspects (e.g., number of emission points, furnace types, furnace stack flow rates, process fugitive enclosure hood flow rates, etc).  Instead, the EPA scaled the costs submitted by RSR for each individual facility based on the reported flow-rates of each emissions point. For example, the costs incurred would be influenced by the size of a facility and the distance between existing control devices. The Quemetco CA facility covers a much smaller area than many of the facilities and the costs for ducting existing control devices into a polishing WESP could be substantially higher for larger facilities. We further note that the EPA assumed that, at each facility, the WESP would treat both process and process fugitive emissions (those emissions that are controlled via baghouses rather than those controlled via cartridge collectors), consistent with information submitted by RSR.  Commenter 95 is therefore incorrect in their statement that the EPA believes that RSR uses the WESP unit to treat fugitive emissions (i.e., building ventilation systems). The EPA believes the cost estimate developed for installation of a WESP at other secondary leads smelting facilities is a reasonable estimate.  Furthermore, the commenter provided no facility-specific cost estimates to demonstrate that the EPA's estimates are not reasonable. See response at page 90 for discussion of the proposal post-control acute hazard index of 5.
      Comment:  Commenter 95 stated that the EPA should have relied on SCAQMD rule 1420.1 as a basis for adopting alternative standards and requirements for stack emissions of metal HAP.  The commenter argued that SCAQMD rule 1420.1 covers the secondary lead smelting facility with the best control (Quemetco, CA) as well as one identified by EPA as most likely to flirt with non-compliance (Exide Technologies, CA).  The commenter stated that the SCAQMD rule is based on an "up-to-date and robust technical basis reflecting SCAQMD staff analyses..."
      Response:  We are familiar with SCAQMD 1420.1, and did in fact take many aspects of that rule into consideration when developing the revised NESHAP for this source category.  However, we believe first that all of the SCAQMD 1420.1 standards are not necessary to reduce risk to an acceptable level under section 112 (f)(2) and that further controls are not needed to provide an ample margin of safety, and also believe that the full panoply of control under the SCAQMD rule is not necessary as part of further technology-based standards under section 112 (d)(6).  Thus, it is neither necessary nor appropriate to uncritically apply to an entire source category the standards developed by SCAQMD for two facilities in a unique geographic area with particularly unusual  meteorological characteristics.  The commenter cites the total facility mass lead emission rate of 0.045 pounds per hour and the maximum lead emission rate of 0.01 pounds per hour specified in SCAQMD 1420.1.  The commenters claim that "SCAQMD's decision to adopt the new Rule 1420.1 and the more rigorous standards it contains was driven by the need to meet the NAAQS as revised in 2008..."  We acknowledge that SCAQMD's analysis may have determined that the aforementioned emissions limits may be necessary in order for the Exide Technologies and Quemetco, Inc. facilities located in southern California to meet the revised lead NAAQS.  However, our analysis indicates that unacceptable risk from lead emissions can be eliminated, with an ample margin of safety, by adopting the controls in this final rule. See The Residual Risk Assessment for the Secondary Lead Smelting Source Category, available in the docket. The lowered stack emission limit will ensure that unacceptable risk from stacks is eliminated and we have finalized requirements to significantly reduce fugitive emissions (the dominant contributor to risk from this source category) from secondary lead smelters through the implementation of fugitive emission work practices, many of which are included in SCAQMD 1420.1, and through requiring all secondary lead sources to install total enclosures maintained under negative pressure and vented to a control device for all lead-bearing materials.
      Comment:  Commenter 98 argued that any standard set under section 112(d), including those set under section 112(d)(6), must meet the requirements of section 112(d)(2) requiring standards to reflect the maximum achievable degree of emission reduction.  By this logic, the commenter stated that the EPA has no justification for failing to recalculate the MACT floor for lead based on new technologies.  The commenter stated that the EPA therefore must set the standard for existing sources at the average emission level achieved by the best performing 5 sources, and at the level achieved by the best controlled similar source for new sources.
      The commenter stated that the EPA cannot rely on the HON case to evade its duty to satisfy section 112(d)(6).  According to the commenter,

      EPA is right that the HON decision stated that it did "not think the words `review, and revise as necessary'" required EPA to recalculate the floors "from scratch" in that case.  NRDC v. EPA, 529 F.3d at 1084.  The court explained that there was no need to address whether EPA had satisfied section 112(d)(6), and that "we do not have to decide this questions because in its final rule, EPA squarely found that there were no significant developments in practices, processes and control technologies, and petitioners do not challenge this conclusion."

      As noted, there are such "developments" for this source category.  Therefore, EPA cannot rely on the HON case to evade its duty to satisfy section 112(d)(6).  Even under NRDC  -  assuming arguendo that its section 112(d)(6) holding is in any way relevant here  -  section 112(d)(6) requires EPA to recalculate the MACT floor when there have been advances in technology, practices, and processes, and when there is information showing that greater emission reductions have been "actually achieved."  Commenter contend that, based on the information EPA has, it is therefore "necessary" for EPA to strengthen the existing MACT floor to ensure it now complies with section 112(d)(2)-(3).

      The commenter further argues that since the EPA must set new MACT floors based on developments in technologies, practices, and processes, it may not consider cost in setting the new MACT standard for lead.
      Response:  First, EPA determined long ago that section 112 (d)(6) does not require MACT floors to be recalculated, and why EPA's interpretation that no further floor analysis is required was reasonable.  See 70 FR at 20008 (April 15, 2005). EPA is not reopening that issue here, or otherwise reconsidering its interpretation.  Thus, this comment is considerably out of time.  Moreover, the argument was rejected by the D.C. Circuit in the HON opinion.  See 529 F. 3d at 1084 ("It is argued that EPA was obliged to completely recalculate the maximum achievable control technology-in other words, to start from scratch. We do not think the words "review, and revise as necessary" can be construed reasonably as imposing any such obligation.").  We thus disagree with the assertion that the HON Court's ruling that CAA section 112(d)(6) does not require re-calculation of MACT floors was limited to instances in which there have not been developments in practices, processes, or control technologies. In fact, the Court was quite clear on this point, and declined to rule only on whether it was appropriate for the EPA to consider costs and risks in conducting CAA section 112(d)(6) reviews, as the issue was rendered moot by the litigants' failure to preserve it.
      To the extent that the commenter is arguing more generally that section 112 (d)(2) is technology-forcing and therefore dictates that EPA must revise MACT standards to reflect new technological developments, see responses on pages 30 above.
      Comment:  Commenter 98 stated that the proposed standard for lead and other metal HAPs pursuant to the technology review is arbitrary and capricious for three reasons.  First, the EPA fails to discuss controls required by the South Coast Air Quality Management District (SCAQMD) and compare them to its proposed rule.  The commenter argues that such an omission violates the EPA's requirements under section 112(d)(6).  Second, the EPA provides no explanation for not considering reductions achievable by the use of HEPA filters downstream of baghouses.  The commenter stated that the DHEQ permit for Johnson Controls mandates use of HEPA filters which demonstrates their feasibility.  Third, the commenter argues that the EPA does not provide a rationale for proposing a standard at a level where almost all facilities have achieved it, rather than set at a lower level of pollution that is "achievable".  The commenter stated that "Implicitly, EPA suggests that it chose the proposed standard because it happened to match the proposed standard it developed under the residual risk analysis."
      The commenters contend that "EPA's proffered justifications show that the proposed standard is arbitrary and capricious.  They fail to comport with the technology-forcing aspect of the Act and of the MACT.  They render the standard a mostly empty formality since almost all facilities and stacks are already meeting the standards."
      Response:  As noted above, we did evaluate the controls required in SCAQMD 1420.1.  For example, we evaluated a significantly lower lead emissions limit based on the WESP technology implemented at the Quemetco facility in City of Industry, California. See 76 FR 29058 and pages 29-31 above. We also evaluated and ultimately proposed to require total enclosures for the same process and process fugitive emissions sources listed in SCAQMD 1420.1. See 76 FR at 29072. Furthermore, several of our proposed fugitive emission work practices, though not identical to, are very similar in nature to those listed in SCAQMD 1420.1.  We have explained at pages 29-31 above why further stack controls on lead emissions are not necessary under section 112 (d)(6), and why further controls on fugitive emissions (beyond those based on total enclosure of all lead-based materials) is also not necessary.  With regard to HEPA filters, the EPA did consider whether significant reductions in emissions were demonstrated by use of this technology and determined that the most significant factors influencing reduced lead emissions in this industry were not the use of HEPA filters.  See Summary of the Technology Review for the Secondary Lead Smelting Source Category, at page 5.   We did not believe that the data warranted an emissions standard based on the technology.  While the lead concentrations from stacks equipped with HEPA filters were about 20% lower than those without, the existence of the HEPA filter was not the lone variable influencing the difference in concentration.  Other factors such as age of the primary control device, type of process vented to the emission point, and flow rates likely contributed significantly to the distribution of lead concentrations from the stacks. Additionally, HEPA filters are only applicable to some sources where high exhaust temperature or high particulate loading will not interfere with the proper operation of the filter. Because of these reasons, we did not believe the dataset warranted establishing an emissions standard lower than 0.20 mg/dscm based on the use of a HEPA filter. See Summary of the Technology Review for the Secondary Lead Smelting Source Category, available in the docket.
      We disagree with the commenter that the EPA failed to provide a rationale for the lead emissions standard proposed under section 112(d)(6).  Section 112(d)(6) requires the EPA, in reviewing section 112 (d)(2) standards and determining whether it is necessary to revise them, to evaluate developments in practices, processes, and control technologies.  The data presented in the technical document describing the technology review for this source category clearly demonstrates that advances in fabric filtration have allowed sources in this industry to achieve lead emissions far below the limits established in the 1997 NESHAP. The data collected from industry in ICR responses demonstrated that the average lead concentration in stacks was 0.16 mg/dscm, far below the 2.0 mg/dscm level prescribed in the 1997 NESHAP. See Summary of the Technology Review for the Secondary Lead Smelting Source Category, at page 7, available in the docket. To that end, we have proposed to revise the lead emission standard for this source category to reflect those developments.  The proposed lead emissions standard was not chosen because "most stacks are meeting the standards already", but rather because we determined it to represent a lead concentration achievable by well-performing fabric filters.   Important factors that influenced the outlet concentration achieved by fabric filters were the type of baghouse used (pulse-jet and reverse-air baghouses achieved lower concentrations than shaker baghouses) and the age of the baghouse. Older baghouses had substantially higher outlet concentrations. Possible reasons for the improved performance in newer baghouses include improvements in bag design, improved seating to ensure proper sealing between bags, and more efficient bag cleaning mechanisms.  We further note that we did evaluate an emissions limit based on the WESP used following a fabric filter, another development in practices, processes, and control technologies identified in our review.  However, we determined that the WESP was not a cost-effective control option for this source category The estimated costs that would be incurred to install this technology at all of the facilities in the industry would be roughly $400 million dollars in capital investment with about $46 million dollars of total annualized cost. The cost effectiveness of this option was unacceptably high, given the incremental risk reductions that would be achieved based on this technology. Adverse energy implications of use of a WESP also militate against adopting standards predicated on use of the technology.  Finally, the lead emissions standards under section 112(f)(2) did not, and do not dictate the standards under section 112(d)(6).  The final standards satisfy the requirements of both sections, the analyses under these respective sections are independent of each other.  We further note that the ample margin of safety analysis under section 112 (f)(2) is internally consistent with our determinations under section 112 (d)(6) in that we did not find that further controls were justified based on considerations of cost, cost effectiveness, technical feasibility, and energy use implications.
      Comment:  Commenter 98 stated that in setting the emission standard for lead, the EPA inadequately supported its findings that there are no other less expensive or feasible control options.  The commenter notes that the EPA identified in its own analysis that other facilities are using HEPA filters in addition to baghouses to achieve approximately 20 percent lower outlet lead concentrations than baghouses alone.  The commenter also notes that the DHEQ permit for Johnson Controls mandates construction of HEPA filters with baghouses, demonstrating the viability of their use.
      Response:  While the lead concentrations from stacks equipped with HEPA filters were on average lower than those without HEPA filters, the dataset did not show a large difference in lead concentrations between the emission points.  Outlet concentrations for stacks equipped with fabric filters averaged about 0.14 mg/dscm while stacks equipped with a HEPA filter following a fabric filter averaged about 0.11 mg/dscm. Fabric filters used in pulse-jet baghouses averaged well below 0.10 mg/dscm. See Summary of the Technology Review for the Secondary Lead Smelting Source Category, which is available in docket ID EPA-HQ-OAR-2011-0344 at page 5. The key indicator of performance does not appear to be whether a HEPA filter is used, rather it is what type of baghouse is used and the age of the baghouse, as illustrated by the performance of stacks equipped with pulse-jet baghouses. Furthermore, other factors such as age of the primary control device, type of process vented to the emission point, and type of baghouse likely contributed significantly to the distribution of lead concentrations from the stacks. Additionally, the use of HEPA filters can be difficult for stacks with high particle loading and exhaust gas temperature.  Since the use of a properly designed, well operated baghouse can achieve outlet concentrations that provide an ample margin of safety and do not present the potential technical challenges that can hamper performance of HEPA filters, we do not believe the establishing an emissions standard based on the use of a HEPA filter is warranted.
      Comment:  According to commenter 91:
EPA proposes "a facility-wide, flow-weighted average lead concentration limit of 0.20 mg/dscm to cover all stacks in this source category." 76 FR at 29055-56.  This limit is based on a finding that the allowable emission rate at two facilities was approximately 10 times the Lead NAAQS level, with that finding adjusted downward by 90% to set the proposed limit.  Shell Consulting Report at 4.

      The commenter stated that the EPA used fewer than 5 facilities and allowable, not actual emissions to set the limit.  According to the commenter, this raises questions as to whether the limit complies with statutory directions and also whether it reflects conditions that are representative of those two facilities, rather than the industry as a whole.  The commenter notes that, for example, the approach taken by the EPA in setting the limit "fails to recognize that a number of facilities in the category emit from very tall stacks (e.g., Buick's 200 foot stack) that disperse the plume over a much larger area, and thus have relatively low ground level concentration at the unit."
      Response:  The EPA is adopting a flow-weighted average lead concentration limit of 0.20 mg/dscm under the authority of section 112(f)(2) and separately under the authority of section 112(d)(6).
      The limit being promulgated under section 112(f)(2) ensures that the risk due to allowable stack emissions from this source category is acceptable.  We have discussed the use of both allowable and actual emissions in previous actions, including the final Coke Oven Batteries residual risk rule (70 FR 19998-19999, April 15, 2005) and in the proposed and final Hazardous Organic NESHAP (HON) residual risk rules (71 FR 34428, June 14, 2006, and 71 FR 76603, December 21, 2006, respectively). In those previous actions, we noted that modeling the allowable levels of emissions (i.e., the highest emission levels that could be emitted while still complying with the NESHAP requirements) is inherently reasonable since they reflect the maximum level sources could emit and still comply with national emission standards.  We further note that standards set under section 112(f)(2) are not MACT floors and are therefore are not developed using  the MACT floor setting procedures (i.e., consideration of the five best performing facilities) of section 112(d)(2) and (3).
      The limit being promulgated under section 112(d)(6) was a result of the technology review conducted for this source category.  As described in the preamble, we determined that the main development in practices, processes, and control technologies for this source category was for fabric filtration.  We also identified an additional control technology (i.e., a WESP), but determined that it was not cost effective, 76 FR at 29059-60, and has negative energy implications.  We also noted that in conducting the section 112(d)(6) reviews, the EPA is not obliged to completely recalculate the prior MACT determination, and, in particular, is not obligated to recalculate the MACT floors. NRDC v. EPA, 529 F.3d 1077, 1084 (D. C. Cir., 2008).  The commenter expressed concern that the proposed limit may reflect the conditions of the two facilities, rather than the industry as a whole.  We disagree with this assessment since 74 of the 93 stacks identified in the ICR that are controlled using a baghouse reported average lead concentrations of less than 0.20 mg/dscm.
      Comment:  Commenter 95 recommended that the EPA revise the proposed rule to include emission standards for lead and other HAP that reflect the best control technologies currently utilized by the industry, and limit emissions to nine pounds of lead per year from process stacks.  The commenter also recommends a facility-wide stack emissions limit of 25 pounds per year of lead.
      The commenter stated that the proposed flow-weighted standard for lead will not result in mass reductions of lead and other HAPs.  The commenter contends that instead of installing additional air pollution controls or procedures to achieve compliance, facilities will simply direct air flow through "cleaner" process vents that would offset higher concentrations from "dirtier" process vents.
      Response:  The emission standard for lead in the final rule reflects our assessment of the developments in practices, processes, and control technologies for this industry.  Based on our review, advances in fabric filtration have made it feasible for sources in this industry to achieve stack lead concentrations less than 0.20 mg/dscm.  We did identify one add-on control technology with the ability to reduce lead concentrations substantially beyond the levels achieved by a well-maintained fabric filter (i.e., the WESP).  However, we note that our technology review under section 112(d)(6) includes an analysis of the technical feasibility of applying the identified developments in practices, processes, and control technologies, as well as the estimated impacts of applying these developments, including cost.  Based on these considerations, we determine whether it is necessary to amend the regulation to require any of the identified developments.  As discussed in Summary of the Technology Review for the Secondary Lead Smelting Source Category, we determined that the WESP is not a cost-effective control technology, and has negative energy implications, and that it would therefore not be appropriate to revise the lead emission standard based on use of this technology.
      We believe that it is highly unlikely that facilities will simply direct additional air flow through the "cleaner" process vents in order to offset higher concentrations from the "dirtier" process vents because rerouting these processes and modifying the control devices could require significant investments. Additionally, facilities would be required to modify their Title V permits, it is unlikely that their permitting agencies would allow for such modifications when the intention would clearly be to flout the intention of an emission standard.
      Comment:  Commenter 98 noted that the vast majority of stacks are already meeting the proposed emission standard for lead.  The commenter also notes that even the average lead emissions from all sources, which distorts the representation of what most facilities are achieving, stands below the proposed emission standard.  The commenter contends that the data demonstrate that the emission standard can be lowered, taking feasibility and cost into account.
      Response:  The emission standard for lead represents a level that we determined is achievable by a well-performing fabric filter, which is the main technology we identified that is currently used by this industry (although, as noted, not all fabric filters perform equally; the revised standard is predicated on use of the best fabric filters coupled with a rigorous maintenance schedule). We evaluated proposing a lower emission standard based on the WESP technology, but determined that it was not appropriate when considering cost.  Therefore, a flow-weighted average lead concentration limit of 0.20 mg/dscm is appropriate for this source category since it represents a level achievable by the best-performing version of the control technology implemented by this industry (i.e., a new, well operated and maintained baghouse).
      Comment:  Commenter 98 stated that the data support a lower standard for lead for fugitive emissions that are vented to a stack from the required total enclosure.

      Response:  We agree that the average lead concentration in stacks that only contain vents from buildings is lower than the process vent stacks.  These vents are expected to have lower lead concentrations because the inlet lead concentration is far lower from building sources than from process sources.  Furthermore, our analysis indicates that building vents are the sources most amenable to the addition of HEPA filtration.  The EPA considered establishing sub-categories for the lead emission standard.  However, there are several different types of vents that would need to be considered.  Furthermore, each facility combines these process vents in different ways, limiting the information available from any individual source type.   Therefore, we adopted a flow weighted average limit that takes into account all types of sources, adding compliance flexibility for the same emission reductions, and making it unnecessary to adopt a separate emission standard for each type of vent.

      Comment:  Two commenters (90, 93) agreed with the EPA's conclusions with respect to the evaluation of the WESP technology.
      Response:  We acknowledge the commenters' support.
      Comment:  Two commenters (92, 80) supported the EPA's facility-wide flow weighted emissions limit for lead.
      Response:  We acknowledge the commenters' support.
   a. Total Hydrocarbons (THC) and Dioxins and Furans (D/F)
      Comment:  Commenter 92 fully supports the work practice requirement to separate plastics entering the furnace.  The commenter suggested including a procedure to correlate the approximate plastic separation with the stack test results for organic HAP and dioxin and furans.  The chromium electroplating NESHAP was given as an example regulation that tied an operating parameter to performance testing.