**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
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The primary

contact regarding questions or comments on this document is:3

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: topham.nathan@epa.gov4 **TABLE OF CONTENTS Section**  **Page No.** 1.0 IN TRODUCTION
................................ ................................ ................................ .............. 7 2.0 LIST OF COMMENTERS
................................ ................................ ................................ . 7 3.0 SUMMARY OF PUBLIC COMMENTS
................................ ................................ ........... 3 3.1 Emissions L imits and Guidelines
................................ ................................ ............ 3 3.1.1 Statutory

Basis
................................ ................................ ............................ 3 3.1.2 Fugitive Emissions L imits
................................ ................................ ........ 13 a. General
................................ ................................ ................................ ...... 13 b. Ambient Monitoring Requirements
................................ .......................... 20 c. Rule Clarifications
................................ ................................ .................... 21 3.1.3 Stac k Emissions L imits
................................ ................................ ............. 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
................................ ................................ ......................... 91 3.3 Baseline Emissions Estimates
................................ ................................ ............... 93 3.3.1 Fugitive Emissions Estimates
................................ ................................ ... 93 3.3.2 Stack Emissions Estimates
................................ ................................ ........ 95 3.4 Compliance Timeline
................................ ................................ ............................ 96 3.5 Performance Testing
................................ ................................ ........................... 101 3.5.1 Te sting Frequency
................................ ................................ ................... 101 3.5.2 Continuous Emissions Monitoring Sy stems (CEMS)
............................. 102 3.5.3 Bag Leak Detection Sy stems (BLDS)
................................ .................... 105 3.6 Ty

pographical Corrections
................................ ................................ .................. 106 3.7 SSM and Affirmative Defense
................................ ................................ ............ 107 3.8 Request for Comment Period Extension
................................ ............................. 120 3.9 Miscellaneous
................................ ................................ ................................ ..... 1205

**List of Acronyms and Abbreviations Acronyms**  ABR Association of Battery Recyclers ATSDR Agency

for Toxic Substances and Disease Registry BLDS Bag Leak Detection Sy stem CAA Clean Air Act CEMS Continuous Emissions Monitoring System CERCLA Comprehensive Environmental Response, Compensation, and L iability 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 IR IS Integrated Risk Information Sy stem 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 poly

tetrafluoroeth yl ene RCRA Resource Conservation and Recovery Act REL Recommended Exposure L imit REL Recommended Exposure L imit6

RfC Reference Concentrations RME Reasonable Maximum Exposure RQ Reportable Quantity (CERCLA) RTR Risk and Technology Review SCAQMD South Coast Air Quality Management District SI C 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 Organization7

**1.0 INTRODUCTION**  On May 19, 2011 , EPA proposed revisions to the National Emission Standards for Hazardous Air Pollutants (NESHAP ) for Secondary L ead Smelters
. Some sign ificant 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 dock et 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

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. **2.0 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
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- 0344 . The commenter, affiliation, and item number in Docket EPA
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- 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**  **EP A**  **- HQ**  **- OAR** **- 2011**  **- 0344** 

**Docket ID Commenter ID**  **Code Commenter and Affiliation** 
EPA
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- 0069.1 69 Robert Steinwurtzel, Attorney , Baker Hostetler on behalf of the Association of Battery Recyclers EPA
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- 0070.1 70 Robert Steinwurtzel, Attorney , Baker Hostetler on behalf of the Association of Battery Recyclers EPA
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- 0071 71 Dennis Lane, Attorney , Stinson Morrison Hecker LLP on behalf of Doe Run Resources Corporation EP A
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- 0072 72 Frederick A. Ganster, Director, Environmental Health and Safety , Exide Technologies8

**Docket ID Commenter ID**  **Code Commenter and Affiliation** 
EPA
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- 0073 73 Michael Carr, Vice President, Johnson Controls Battery

Group, Inc. EPA
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- 0074.1 74 Robert Steinwurtzel, Attorney , Baker Hostetler on behalf of the Association of Battery Recyclers EPA
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- 0075 75 Michael Carr, Vice President, Johnson Controls Battery

Group, Inc. EPA
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- 0076 76 Robert Steinwurtzel, Attorney , Baker Ho stetler on behalf of the Association of Battery Recyclers EPA
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- 0078.1 78 Kerry Russell, Attorney , Russell and Rodriguez on behalf of the City of Frisco, Texas EPA
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- 0079.1 79 John Cooper, President, Cooper Environmental Services EPA
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- 0080 80 James Kavanaugh, Director, Air Pollution Control Program, Missouri Department of Natural Resources EPA
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- 0081.1 81 John Cooper, President, Cooper Environmental Services EPA
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- 0082 82 Jerry Campbell, Director, Air Management Division, Environmental Protection Commission of Hillsborough County, Tampa, FL EPA
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- 0083 83 Anony mous EPA
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- 0084 84 John Cooper, President, Cooper Environmental Services EPA
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- 0085 85 Krag Petterson, Pall Corporation EPA
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- 0086 86 G. Vinson Hellwig and Robert Colby , Co
Chairs, National Association of Clean Air Agencies Air Toxics Committee EPA
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- 0087.1 87 Timothy J. LaFond, Environmental Committee Chairman, Battery Council International EPA
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- 0088.1 88 Billy Nichols, Principal Engineer, URS Corporation on behalf of Sanders Lead Company9

**Docket ID Commenter ID**  **Code Commenter and Affiliation** 

EPA
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- 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
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- 0090.1 90 Michael Carr, Vice President, Johnson Controls Battery

Group, Inc. EPA
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- 0091.1 91 Dennis Lane, Attorney , Stinson Morrison Hecker LLP on behalf of Doe Run Resources Corporation EPA
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- 0092.1 92 J. Jared Snyder, Assistant Commissioner for Air Resources, Climate Change and Energy , New York Department of Environmental Conservation EPA
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- 0093.1 93 Richard Leib y, Vice President, Metals Operations, East Penn Manufacturing EPA
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- 0094.1 94 Dean A. Rossi, Vice President

– Global EHS, Exide Technologies EPA
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- 0095.1 95 Homer P. Hine, Vice President, RSR Corporation EPA
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- 0096.3 96 Robert Steinwurtzel and Mark DeLaquil, Attorney s, Baker Hostetler on behalf of the Association of Battery

Recyclers EPA
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- A5 N/A (Attachment) Robert Steinwurtzel and Mark DeLaquil,

Attorney s, Baker Hostetler on behalf of the Associ ation of Battery

Recyclers Attachment A EPA
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- A6 N/A (Attachment) Robert Steinwurtzel and Mark DeLaquil,

Attorney s, Baker Hostetler on behalf of the Association of Battery

Recyclers Attachment B EPA
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- A7 N/A (Attachment) Robert Steinwurtzel and Mark DeLaquil,

Attorney s, Baker Hostetler on behalf of the Association of Battery

Recyclers Attachment C10

**Docket ID Commenter ID**  **Code Commenter and Affiliation** 

EPA
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- A8 N/A (Attachment) Robert Steinwurtzel and Mark DeLaquil,

Attorney s, Baker Hostetler o n behalf of the Association of Battery

Recyclers Attachment D EPA
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- A9 N/A (Attachment) Robert Steinwurtzel and Mark DeLaquil,

Attorney s, Baker Hostetler on behalf of the Association of Battery

Recyclers Attachment E EPA
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- A10 N/A (Attachment) Robert Steinwurtzel and Mark DeLaquil,

Attorney s, Baker Hostetler on behalf of the Association of Battery

Recyclers Attachment F EPA
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- A11 N/A (Attachment) Robert Steinwurtzel and Mark DeLaquil,

Attorney s, Baker Hostetler on behalf of the Association of Battery

Recyclers Attachment G EPA
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- A12 N/A (Attachment) Robert Steinwurtzel and Mark DeLaquil,

Attorney s, Baker Hostetler on behalf of the Association of Battery

Recyclers Attachment H EPA
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- A2 97 My ra C. Reece, Chief, Bureau of Air Quality , South Carolina Department of Health and Environmental Control

EPA
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- 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
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- 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
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- A2 N/A (Attachment) Earthjustice, on behalf of California

Communities Against Toxics, Desert Citizens Against Pollution, Miss ouri Coalition for the Environment, Natural Resources Defense Council, and Sierra Club Attachment11

**Docket ID Commenter ID**  **Code Commenter and Affiliation** 

EPA
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- 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
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- A4 N/A (Attachment) Earthjustice, on behalf of California

Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalit ion for the Environment, Natural Resources Defense Council, and Sierra Club Attachment

EPA
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- A5 N/A (Attachment) Earthjustice, on behalf of California

Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition fo r the Environment, Natural Resources Defense Council, and Sierra Club Attachment

EPA
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- 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
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- 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
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- A8 N/A (Attachment) Earthjustice, on behalf of California

Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Enviro nment, Natural Resources Defense Council, and Sierra Club Attachment

EPA
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- 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 Attachment12

**Docket ID Commenter ID**  **Code Commenter and Affiliation** 

EPA
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- 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
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- 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
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- A2 N/A (Attachment) Earthjustice, on behalf of California

Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Reso urces Defense Council, and Sierra Club Attachment

EPA
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- 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
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- 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
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- A5 N/A (Attachment) Earthjustice, on behalf of California

Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defens e Council, and Sierra Club Attachment

EPA
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- A6 N/A (Attachment) Earthjustice, on behalf of California

Communities Against Toxics, Desert Citizens Against Pollution, Missouri Coalition for the Environment, Natural Resources Defense Coun cil, and Sierra Club Attachment13

**Docket ID Commenter ID**  **Code Commenter and Affiliation** 

EPA
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- 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
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- 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 Si erra Club Attachment

EPA
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- 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 C lub Attachment

EPA
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- 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
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- 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
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- 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
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- 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 Attachment14

**Docket ID Commenter ID**  **Code Commenter and Affiliation** 

EPA
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- 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
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- 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
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- 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
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- 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
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- 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
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- 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
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- 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 Attachment15

**Docket ID Commenter ID**  **Code Commenter and Affiliation** 

EPA
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- 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
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- 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
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- 0111 111 Matt Todd, Chair, The Residual Risk Coalition EPA
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- 0120 120 Krag Petterson, Pall Corporation EPA
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- 0127 127 Robert Steinwurtzel, Attorney , Baker Hostetler on behalf of the Association of Battery Recyclers EPA
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- 0130 130 Robert Steinwurtzel, Attorney , Baker Hostetler on behalf of the Association of Battery Recyclers**3.0 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 man y instances, commenters provided addition al 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. **3.1 Emissions Limits and Guidelines**  **3.1.1 Statutory Basis**  **Comment :**  Comments received from the Secondary L ead 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. The se 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 s eeking 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 pub lic health or prevent environmental effects, and so is not authorized.
 Emissions will be reduced completely independent of the NESHAP because s tates must assemble SIPs without being able to wait for NESHAP completion.
 The two standards would be effectivel y 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 ele mental 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

est ablish standards for individual and unique lead compounds when appropriate based on toxicity or other factors.4

 The proposed rule negates the SIP process for lead NAAQS attainment. The proposed MACT rule accelerates Lead NAAQS attainment without any explanation of wh y 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 objecte d 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. 201 1) 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 an y substantive response is considered to be ne cessary , the lead emitted from secondary lead smelting is lead compounds 1 , 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 effectivel y. 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 em itted 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 appl y t o lead compounds and not to eleme ntal 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 s hall establish such standards with respect

1 Harrison, R.M. and Williams, C.R. (1981). Environmental Science and Technology, Vol. 15:10, p. 1197

- 1204.; Ohmsen, G.S.(2001). Journal of the Air and Waste Management Association, Vol. 51, p. 1443

- 1451.; Uzu, G., Sobanska, S., Sarret, G., Sauvain, J.J., Pradère, P., and Dumat, C. (2011). Journal of Hazardous Materials, Vol. 186, p. 1018
- 1027.; Spear, T.M., Svee, W., Vincent, J.H., and Stanisich, N. (1998). Environmental Health Perspectives, Vol. 106:9, p. 565

- 571.; Czaplicka, M., and Buzek, Ł. (2011). Water, Air, & Soil Pollution, Vol. 218, p. 157

- 163.; Sobanska, S., Ricq, N., Laboudigue, A., Guillermo, R., Brémard, C., Laureyns, J., Merlin, J.C., Wignacourt, J.P. (1999). Environmental Science and Technology, Vol. 33, p. 1334

- 1339.; Harrison, R.M. and Williams, C.R. (1983). The Science of the Total Environment, Vol. 31, p. 129

- 140.; Batonneau, Y., Bremard, C., Gengembre, L., Laureyns, J., Maguer, A.L., Maguer, D.L., Perdrix, E., and Sobanska, S. (2004). Environmental Science and Technology, Vol. 38, p. 5281
- 5289.; Foster, R.L. and Lott, P.F. (1980). Environmental Science and Technology, Vol. 14:10, p. 1240

- 1244.5

to the health and environmental effects of the substances actually emitted by

sources and direct transformation b yproducts of such emissions...”. The EPA has done so here, evaluating risks with respect to actual em issions 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 N ational L ime 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 comm enter 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 i ndependent 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 b y 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 l ead 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 secti on 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 suc h a pollutant to the HAP list. Nor has the EPA listed “elemental lead” as a hazardous air pollutant, in vi olation of section 112 (b)(7). Regulating lead compounds is simply not the same thing as l isting 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 mu st be tailored in such a way

as not to interfere with NAAQS implementation “because the NAAQS already6

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 sec tion 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 th erefore 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

- ba sed standards under section 112 (d) where consideration of risk, and hence of the protections afforded b y 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 compo unds due to chemical reactions) , and EPA thus does not accept it. 2 The commenter s raise a number of issues regarding the relation o f 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 stat ed, 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 whereb y states develop implementation plans for attaining and maintaining the NAAQS. 3 That process will necessaril y 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 invo ked in SIPs for PM and ozone). Inthis 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 mistakenl y takes as showing that this rule was adopted to assure attai nment of the lead NAAQS, was intended only as a ‘ good government ’ ty pe of

2 We repeat that the time to raise the issue was when it was first presented in the 1997 NESHAP rulemaking. 3 One commenter went so far as to call the rule a surrogate Federal Implementation Plan, adopted impermissibly. The rule does not dictate NAAQS attainment strategies, but rather prevents unacceptable risk to airborne exposure to lead compounds, with an ample margin of safety. This is in accord, among other things, with Congress’ listi ng of lead compounds as a HAP in section 112 (b)(1) w hich sets in motion the consequences under the remainder of section 112 for listed HAP. States may, but are not required to, consider this rule as part of the NAAQS attainment process, but that does not make the rule a FIP any more than an NSPS controlling ozone precursors are FIPs for ozone or any section 112 (d) rule controlling PM as a surrogate a FIP for PM.7

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 an y other provision applicable to NAAQS implementation. Put another way , s ection 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 an ything. 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 emissi ons 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 conclud ed 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 and8

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 amb ient 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 us ed 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 b y work practice standards (as is allowed under section 112(h)(1)). Finall y, 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. How ever, 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 t yp es. Thus, EPA effectively established the MACT floor for these sources. According to the commenter, “EP A 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 onl y as necessary according to explicit statutory criteria... The CAA is not intended to allow the Agency to revisit previousl y - established MACT standards in effort t o 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 comment er, “This explanation makes it clear that EPA is invoking 112(d)(2) and (3) directly as authority

to amend Subpart X as if a9

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 rel y 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 co mmenter 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 day s of their promulgation and that facilities regulated by Subpart X have already made capital investments to meet the existing MACT standards. EPA should justify wh y the decisions reflected in the current standards are wrong and wh y 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. Accordin g to the commenter, “Clean Air Act §§112(d)(6) allows EPA to revise onl y 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 furn aces), so it may

not promulgate revised standards for these substances under that authority”. Commenter 90 stated that the proposed r ule 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:10

The RTR Proposed Rule’s basis for revising the lead emission MACT floors pursuant to CAA § 112(d)(6) is that the Agenc y "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 o f a particular control, but does not answer the antecedent question of whether or not imposing such control is necessary

t o protect public health or the environment in light of other legal requirements that the CAA applies to the secondary lead smelting ind ustry
. **Response :**  In Medical Waste In stitute v. EPA , 645 F. 3d 420, 425

- 27 (D.C. Cir. 2011), the D.C. Circuit h eld 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 L ime , 233 F. 3d at 633
- 34; s ee also Medical Waste Incinerator, 645 F. 3d at 426 (resetting MACT floor, based on post - compliance data, permissible when originally

- established floor was improperl y 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 comm enters 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 ad opting one for the first time. That is the case here for THC (from some furnace typ es) , dioxin and mercury emissions. Here, EPA adopted no MACT standard at all for these HAP, an approach soundly rejected b y 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 commenter s point out that that section 112(b)(6) of the CAA prescribes the11

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 commenter s 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 commenter s 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 section s 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 consi der the lead aspect of lead compounds for purposes of regulating elemental lead under PSD. The commenter s argue that, to conclude otherwise would mean that lead compounds are subject to duplicative regulation under both the NESHAP program and PSD, which the commenter s 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 provis ions 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 an y 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 1 997 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), and12

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 concentratio ns , the commenter claims that the EPA determined that the weight of elemental lead could be disaggregated from lead compounds , citing 67 F ed. R eg. 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 rel yi ng 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. Itis entirely reasonable for the EPA to consider the toxicity of lead compounds based on elementa l lead toxicity , and indeed, there are no suggestions on this record that there is an y 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 section s 112(b)(6) and (7) prec lude 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 lead13

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 generall y. Prevention of Significant D eterioration (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 m ore 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 Rev iew (NSR): Baseline Emissions Determination, Actual

- to - Future
- Actual Methodology , Plantwide Applicability Limitations, C lean Units, Pollution Control Projects , 67 F ed. R eg. 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 compo unds 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
. **3.1.2 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 n either 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 practice14

should be based on modeling of ambient levels achieved as a result of optimal implementation of tho se work practices. This standard may not simply

replicat e the limit of the lead NAAQS.” For the alternative of monitoring lead concentrations in air plus work practices , the commenter stated that “Simply replicating th e lead NAAQS through monitoring... is n ot a valid substitute for doing an actual 112(d)(3) and 112(d)(6) anal ys is 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 hav e 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 do es not meet the requ irements of section 112(d)(6). First, i t 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 o f 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 emission s are not directly measurable (this is why

they are t ermed ‘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 effectivel y 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 standard s 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 with out creating workplace15

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 r einforced b y som e ty pe of numeri c standard tied to fenceline monitoring. EPA is not adopting this ty pe 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 standa rds 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 Aroun d Secondary Lead Smelting Facilities , which is available in the docket (EPA

- HQ
- OAR
- 2011
- 0344)
. Mon itoring 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 vent ilation to a control device ensures that fugitive emissions will not escape buildings through doorway s or other openings. Work practice standards, such as those requiring vehicle washing prior to leaving a total enclosure ensure that lead bearing dust with in 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 an y 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 pract ice requirements for fugitive emission s that are not vented to a stack. Hence , the final standard s for fugitive lead emissions are clearly warranted under section s 112(f) and 112(d)(6).16

We note that we did evaluate the work practices already emplo yed b y 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 chall enges posed by conditions in the L os 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 prac tice 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 adequatel y 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 w as 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 emissio ns reduction o f 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 ove restimated 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 man y of the activities that the proposed work practice requirements are aimed at addressing. The commenter s further no te 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 underl yi ng 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 are17

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 collectivel y 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 coll ectively 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 th at “This rationale is incorrect because several facilities meet the lead NAAQS at all monitors near their property boundaries without applying these measures.” The commenter pro vides Gopher Resources, East Penn, RSR (NY), and RSR (IN) as examples of facilities that are currently and regularl y 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 not ed 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 rel yi ng on the SCAQMD rule, nor did it introduce that rule or an y administrative materials underl yi ng it s 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 bas is 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 request ed that EPA reassess the overall strateg y 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 fugitive18

dust control measures are effective...” The commenter requests that EPA specif icall y 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 c asing 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 req uested that the mandatory work practice requireme nts be removed from Subpart X. **Response :**  T he 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 th at 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 propo sed work practice. We have done additional modeling for the source category based on the updated fugitive emission estimates (reflecting slightl y reduced emission s from fugitive emissions) and the conclusions remain the same as at proposal . Lead emissions still remain unacceptabl y 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 estimate s 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 b y the best performing five sources in industry . However, the work practices are being adopted unde r 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 calcu lation involving the best performing five sources , but rather is based on developments in control practices, processes and technologies and may reflect19

considerations of cost (including cost effectiveness) of adopting additional controls and non

- air and en ergy

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 o f Industry

that are subject to the SCAQMD 1420.1 rule, while some of these work practices are conducted b y man y other facilities (e.g., pavement or groundcover of facility grounds , transport of dust in sealed containers or conveyor sy stems ). T he work practices are also being adopted under section 112(f)(2). The preamble to th e proposed rule clearl y described that our anal ys es indicated that the proposed work practices were necessary to achieve lead concentrations near the boundaries of the fac ilities 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 currentl y performing at that level. With regard to the facili ties described b y the commenter as meeting the lead NAAQS without implementation of the proposed work practices and therefore should not requir e further control under section 112 (f) (2) , we note that this rule implements section 112 (f)(2), not the lead p rimary

NAAQS
. S ection 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 legall y permissible . (The work practi ce 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 th e 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 , thereb y ensuring the public is protected from these emiss ions with an ample margin of safety. Each facility must also develop and submit a SOP to their local20

permitting authority for approval to ensure that the facility properl y 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 enclo sures (§63.544(d)(1)

– (d)(8)). **Response :**  We thank the commenters for drafting recommended language; however, because we have rem oved 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 suffi cient 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 strengthen ed to require continuous measurement from a sufficient number of monitors to capture both the dominant and intermittent wind patterns and regular verification and oversight b y 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 ye ars of meteorological data and approved regulatory modeling. A second compliance monitor located at or near the plant boundary is nec essary

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 on21

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 accordingl y. 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** : W e 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** : Co mmenter 90 noted that the EPA used the terminology “continuous monitoring sy stem” in the proposed ambient monitoring requirements. This monitoring sy stem is not a continuous monitoring s ys tem and the specifications for CMS in §63.8(c) would not be appropriate. **Response** : W e 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 b y 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
.22

**R esponse**  **:** We note that the general provisions in 40 C
. F
. R
. Part 63 Subpart A at §63.6(g) that appl y to a request for approval of an alternative to a standard are specificall y 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 b y background lead concentrations. The commenters requested confirmation that monitored NAAQS exceedance s 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 μg/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 wer e already “emission standards.” **Response :**  W e 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 a bove, 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 sources23

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 hav e 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
. **3.1.3 Stack Emissions Limits** 
a. Lead and Other Metal HAP **Comment :**  Commenter s 90 and 96 argue that EPA has misapplied CAA section 112(d)(6) and should not be adopting an y 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 11 2(d)(6) standards are not “necessary” here because they are unnecessary

to protect public health and the environment. **R esponse**  **:** The EPA does not agree that determining whether standards under CAA section 112(d)(6) are “necessary” 4 is determined exclusiv ely 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 s ection 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 b y risk

- based considerations. Consequently the EP A does not believe that a CAA section 112 (d)(6) standard is “necessary” onl y 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 st andards are warranted to prevent unacceptable risk. Moreover, there have been developments in control technologies (e.g. improvements in baghouse design

4 Because the meaning of “necessary” is ambiguous and “varies with context . . .[,] dueling over dictionary definitions is pointless, for it fails to produce any plain meaning of the disputed word.” Cellular Telecomms. & Internet Ass’n v. FCC, 330 F.3d 502, 509

- 10 (D.C. Cir. 2003). The Supreme Court hasdirected that “a statutory reference to ‘nec essary’ must be construed in a fashion that is consistent with the ordinary and fair meaning of the word,” and EPA’s interpretation of “necessary” is entitled to Chevron deference if it is “rationally related to the goals of the Act.” AT & T Corp. v. Iowa Utils. Bd. , 525 U.S. 366, 388 (1999).24

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 0.2 0 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 b y the RTR Proposed Rule. The regulatory changes that affect emissions included reducing the stack lead concentration to 0.20 mg/dscm and reducing th e 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 residua l risk review. The commenter first note d that there are facilities in this source category that currentl y comply with the NAAQS or are projected to comply in the near future without imposition of significantl y reduced concentration limits for baghouses. RSR’s Middletown, NY facility currentl y 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 st ack emissions to be reduced to 0.20 mg/dscm. The commenter points out that at the Exide Frisco facility , in fact, the average flow

- weighted25

concentration of lead from all modeled emission sources exceeds 0.20 mg/dscm and one source has emissions that exce ed 1 mg/dscm. The commenter also stated that sensitivity anal ys es 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 o ffsite 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 co mmenter requested that the EPA rerun the models using actual stack emissions to determine if fugitive emission reductions alone are sufficient to resul t 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 appl y to an entire source category , but do not require every facility to pose unacceptable risk to trigger the section 11 2 (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 appl y 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 currentl y comply with the NAAQS or are projected to comply with the NAAQS in the near future whether or not EPA adopts s tandards for lead which are more stringent than those of the 1997 NESHAP , specificall y citing RSR’s Middletown, NY facility and Exide’s Frisco, TX facilit y. 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 p roposed 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 in26

support of the SIP (availabl e in the docket) requires Exide to replace two existing baghouses with new baghouses fitted with poly tetrafluoroethylene (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 carc inogens, 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 clearl y can be read to apply to allowable emissions (i.e. emissions allowe d 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). T he 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 clearl y be needed to achieve acceptable risk from lead emissions . Moreover, we note that controls that result in r eductions 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, respectivel y) . 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 inherentl y27

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 anal y sis, in accordance with the Benzene NESHAP. **Comment :**  Commenter 95 stated that the proposed standard for stack emissions of metal HAP does not satisfy

th e 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 propose d standard for lead emissions to reduce maximum lifetime cancer risk due to metal HAP e missions 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 anal ys is indicated th at 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 pri mary filter. However, HEPA filters are not alway s 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 conce ntrations 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 d evice, ty

pe of baghouse used, and ty pe of proce ss 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 te mperature or high particulate loading will not interfere with the proper28

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 filte r. 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 electricit y demand, increased emissions associated with electricity generation (with attendant carbon and NO x pollution) , and additional wastewater generation . These significantl y i ncreased 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 ye ars 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 estimat ed cancer risk from actual emission s 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 emissio ns 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 accep table 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 addi tional 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 identify29

any further feasible and cost

- effective controls, and we therefore concluded that the revision s 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 in formation 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. Moreo ver, we note that the baseline MIR due to allowable emissions remains 200 in a million and will be reduced to acceptable levels after co ntrols. We performed an ample margin of safety anal ys is 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 economicall y feasible to reduce cancer risks from fugitive emissions . This anal ys is 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 requir ement 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 pro tect the public health with an ample margin of safety . **Comment :**  Commenters 95 and 98 disagreed with the EPA ’s anal ys is 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 betwe en $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 th at three facilities in th is 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 the30

practices al ready 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

- c ancer HQ that the EPA found is f ive 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 f urther 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 appear s to believe that RSR uses the WESP unit to treat fugitive emissions. **Response :**  First, whether or not section 112 (d)(6) is “technology forcing” 5 , 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. 6 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 e missions , 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). Specificall y, an emissions limit based on this technology would

5 Technology forcing provisions are predicated on performance of technologies not yet in existence but for which a compliance path can clearly be documented (see, e.g. Husqvarna AB v. EPA , 254 F. 3d 195, 201 (D.C. Cir. 2001)) whereas section 112 (d)(6) is predicated not on performance of future projected technologies, but on developments which have occurred in the intervening years following promulgation of the MACT standard. 6 See also AT &T Corp. v. Iowa Utils. Bd ., 5 25 U.S. 366, 388 (1999) (broad meaning to ‘necessary’, and an agency interpretation consistent with statutory goals and objectives is entitled to deference).31

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 roughl y 20 times greater than the control based on performance of state

- of

- the

art baghouses without the f ollowing step of a WESP
. We have determined that the limits included i n 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 abov e, 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 WESP s . 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 ty pes , 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 b y 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 fo r 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 sy stems). The EPA believes the cost estimate developed for installation of a WESP at other secondary lead s smelting facil ities is a reasonable estimate
. Furthermore, the commenter provided no facility

- specific cost e stimates 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 of32

metal HAP. The commenter argue d that SCAQMD rul e 1420.1 covers the secondary lead smelting facility

with the best control (Quem etco , 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 anal ys es...” **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 reduc e 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 panopl y of control under the SCAQMD rule is not necessary as part of further technology

- bas ed standards under section 112 (d)(6). Thus, it is neither necessary nor appropriate to uncriticall y appl y to an entire source category the standards developed by SCAQMD for two facilities in a unique geographic area with particularl y unusual meteorologi cal characteristics. The commenter cites the total facility m a ss 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 b y the need to meet the NAAQS as revised in 2008...” We acknowledge that SCAQMD’s anal ys is 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 anal ys is indicates that unacceptable risk from lead emissions can be eliminated, with an ample margin of safety, b y 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 significantl y 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 inclu ded in SCAQMD 1420.1 , and through requiring all secondary lead sources to install total enclosures maintained under negative pressure and vent ed to a control device for all lead

- bearing materials
. **Comment :**  Commenter 98 argued that an y standard set under section 112(d), including those set under section 112(d)(6), must meet the requirements of section 112(d)(2) requiring33

standards to reflect the maximum achievable degree of emission reduction. By this logic, the commenter stated that the EPA has no justif ication 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 b y the best performing 5 sources, and at th e level achieved b y 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 th at it did “not think the words ‘review, and revise as necessary ’” required EPA to recalculate the floors “from scratch” in that case. NRD C 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 squarel y 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 rel y 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 “actuall y achieved.” Commenter contend th at, 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 develop ments i n 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 interpreta tion 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 is34

considerably out of time. Moreover, the argum ent 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 reasonabl y as imposing an y 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 whe ther 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 generall y that section 1 12 (d)(2) is technology

- forcing and therefore dictates that EPA must revise MACT standards to reflect new technological developments, see response s 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 b y 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 b y 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 anal ys is.” The commenters cont end 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 A ct and of the MACT. They render the standard a mostly empty formality since almost all f acilities and stacks are already meeting the standards.” **Response :**  As noted above, we did evaluate the control s required in SCAQMD 1420
. 1. For example, we evaluated a significantl y lower lead emissions limit based on the WESP technology

implemented at th e Quemetco facility in City of Industry , California. See 76 FR35

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 t o 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 f ilters, 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. W e did not believe that the data warrant ed 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 flo w rates likel y contributed significantl y 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) stan dards and determining whether it is necessary to revise them, to e valuate developments in practices, processes, and control technologies. The data presented in the technical document describing the technology review for this source category clearl y demons trates that advances in fabric filtration have allowed sources in this industry to achieve le ad emissions far below the limits established in the 1997 NESHAP. The data collected from industry in ICR responses demonstrated that the average lead concentratio n 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 the36

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 concentr ation achievable b y well

- performing fabric filters
. Important factors that influenced the outlet concentration achieved by fabric filters were the ty

pe of baghouse used (pulse

- jet and reverse

- air baghouses achieved lower concentrations than shaker baghou ses) 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 inv estment with about $46 million dollars of total annualized cost. The cost effectiveness of this option was unacceptabl y high, given the incremental risk reductions that would be achieved based on this technology
. Adverse energy implications of use of a WES P also militate against adopting standards predicated on use of the technology
. Finally , the lead emissions standard s under section 112(f)(2) did not, and do not dictate the standard s under section 112(d)(6). The final standards satisfy the requirements of both sections, the analy ses 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 th at 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 inadequat el y supported its findings that there are no other less expensive or feasible control options. The commenter notes that the EPA identified in its own analy sis that other facilities are using HEPA filters in addition to baghouses to achieve approximately 2 0 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.37

**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 concentration s 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 ty pe of baghouse is used and the age of the baghouse , as illustrated b y 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, an d ty pe of baghouse likel y 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 properl y 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 emissi ons 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 L ead NAAQS level, with that finding adjusted downward by 90% to set the proposed limit. Shell Consulting Report at 4.
The commenter state d 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 rep resentative of those two facilities, rather than the industry as a whole. The commenter notes that, for example, the approach taken b y the EPA in setting the limit “fails to recognize that a number of facilities in the category emit from very

tall sta cks ( 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.”38

**Response :**  The EPA is adopting a flow

- weighted average lead concentration limit of 0.2 0 mg/dscm under the authority of section 112(f)(2) and separatel y under the authority of section 112(d)(6). T he limit being promulgated under section 112(f)(2) ensure s 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, respectivel y). 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 th e NESHAP requirements) is inherentl y 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) review s , the EPA is not obliged to completel y 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 wh ole. We disagree with this assessment since 74 of the 93 stacks identified in the I CR 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 currentl y 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.39

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 co ncentrations 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 b y a well

- maintained fabric filter (i.e., the WESP). However, we note that our technology

review under section 112(d)(6) includes an anal ys is 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 co st. 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 unlikel y th at facilities will simply direct additional air flow through the “cleaner” process vents in order to offset higher concentrations f rom 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 clearl y 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 facil ities 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 b y a well

- performing fabric filter, which is the main technology we identified that is40

currentl y used b y 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 concentration s because the inlet lead concentration is far lower from building sources than from process sources. Furthermore , our anal y sis indicates that building vents are the sources most amenable to th e addition of HEPA filtration. The EPA considered establishing sub

categories for the lead emission standard. H owever, there are several different ty pes of vents that would need to be c onsidered
. Furthermore, each facility combines these process vents in different way s , limiting the information available from an y individual source type. Therefore , we adopted a flow weighted average limit that takes into account all types of sources , a dding 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 commenter s ’ support
. **Comment** : Two commenter s ( 92 , 80) supported the EPA ’s facility

- wide flow weighted emissions limit for lead. **Response :**  We acknowledge the commenter s ’ support
. b. 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 res u lts for organic HAP and dioxin and furan s .41

The chromium electroplating NESHAP was given as an example regulation that tied an operating parameter to performance testing. **Response :**  We note that we have modified the proposed plastics separation requirement to apply to automotive batteries. We agree with the commenter that it can be useful to tie performance testing results to an operating parameter that can be continuously monitored. That is why we have included exhaust temperature monitoring to demonstrate continuous compliance with the standards for THC and dioxins. While plastics are a source of organic HAP in furnace exhaust, they

are not the only

source. Therefore, we feel that temperature monitoring is the appropriate measure for demonstrating continuo us compliance rather than measurement of plastics separation effectiveness. **Comment :**  Commenters 90 and 96 requested that the EPA clarify proposed 40 C.F.R. § 63.547(e)(2) b y including a specific reference to the 2005 Toxic Equivalency Factors (TEF) from the World Health Organization (WHO). **Response :**  We have made the commenters’ suggested revision to the regulatory text
. **Comment :**  Commenter 80 recommended that the EPA s et the dioxin and furan MACT floor for existing blast furnaces based on the data from the mixed sources (blast furnace off

- gas mixed with reverberatory furnace off

- gas). **Response :**  We did consider assigning all of the D/F emissions from tests at facilities where the vents from blast furnaces are mixed with the vents from reverberatory furnaces after the streams are cooled (where the reverberatory furnace is not controlling emissions from the blast furnace) to the blast furnace in ord er to calculate MACT floors for the blast furnace subcategory
. However, unlike the case of the stack emission standard for lead (where one limit exists regardless of furnace type) , we did not have information regarding the individual flow rate from each f

urnace during the emission tests (which was necessary to incorporate these data into the pool of data used to calculate the MACT floor) , and were therefore unable to assess the relative contribution of each furnace ty pe. **Comment :**  Commenter 93 stated that numeric D/F standards for this industry represent a cost burden disproportionate with an y perceived benefit. The commenter notes that Method 23, the reference method for D/F emission testing, specifies a very complex sampling train, long samp le times, and intricate sample recovery and analy

tical procedures. The commenter stated42

that a ty pical D/F test program will cost an affected facility between $15,000 and $20,000 per test program to complete and will require the emission test team to be o n - site for over three day s. The commenter contends that the EPA should reconsider the imposition of numeric D/F standards on affected Subpart X sources. **Response :**  First, EPA is legally obligat ed to promulgate section 112 (d) (2) standards for listed HAP emitted by

a major source category
. National L ime , 233 F. 3d at 634. It is not disputed that secondary

lead sources emit CDD/CDFs. Second, this standard must be numeric unless the criteria for establishing work practices und er section 112 (h) are satisfied. No commenter attempted such a justification for CDDs, and EPA is not aware of any. In addition, no commenter suggested a legitimate surrogate for CDDs which could be tested at less expense. Consequently , EPA believes th at some ty pe of numeric standard for CDD/CDF is legally required
. **Comment :**  Commenter 94 and 96 note d that the EPA has propos ed to change the definition of collocated blast furnace and reverberatory furnace by

removing from the subcategory

those blast and reverberatory furnaces whose gases are not mixed prior to cooling. The commenters note d that ABR and the EPA worked collaborativel y to identify a subset of industry

stacks across facilities for emission testing intended to inform this rulemaking. The commenters contend that the EPA did not indicate in this information collection process that the Agency was considering redefining the collocated blast and reverberatory furnace subcategory
. As a result of this change in approach unanticipated by the comment er , only

one collocated blast and reverberatory

furnace was tested, the result being that the EPA ’s proposed dioxin and furan emission limits for this subcategory of five collocated blast and reverb furnace pairs were based solely on emissions test data from a single facility
. Commenter 94 stated that establishing a dioxin and furan limit for collocated blast and reverberatory

furnaces based on a single unit is improper because it “do[es] not represent the average achieved b y the best

- performing sources in the subcategory .” . The commenter also notes that Exide advised the EPA on June 15, 2011 that it is in the process of coordinating stack testing on a collocated blast and reverberatory furnace at its Reading, Pennsylvania facility; Exide expects the data t o be available in September, 2011. The commenter contends that the EPA should ensure that it allows for adequate time to accept and consider the pending test data from Reading in determining the dioxin TEQ limit for collocated blast and reverberatory furn aces.43

**Response :**  We believe that our proposed change to the definition of collocated blast and reverberatory

furnace is appropriate. We maintain that designating a blast furnace and reverberatory

furnace as “collocated” should imply that the much hotter off

- gas of the reverberatory

furnace is providing some level of control for the organic HAP in the relatively cooler blast furnace off

- gas. In order for this to occur, the off

- gas from the reverberatory furnace should be mixed with the blast furnace off

- gas prior to cooling. Section 112 (d)(3) determinations are to reflect sources “for which the Administrator has emissions information” which in thi s case is the East Penn facility
. The data from additional testing at Exide’s Reading facility was not provided to the EPA until November 17, 2011. The data were submitted too late for the proper quality assurance anal ys es to be performed prior to be ing in corporated into the MACT floor calculation. However, we note that a preliminary anal ys is indicates that the limit would have been slightl y more stringent if th ese data were incorporated. See Summary of MACT Floor Analysis for the Secondary Lead Smelting So urce Category
. T he data from the East Penn facility remains the data on which the limit is based. The commenter did not provide an y data showing that the proposed limits were infeasible or unrepresentative of perfo rmance at the East Penn facility ; furtherm ore, the test data provided by Exide in November 2011 only reinforce that this limit is representative of performance of furnaces in this subcategory
. **Comment :**  Commenter 90 requested confirmation that reverberatory furnaces that are collocated with bla st furnaces are onl y subject to the proposed standards for collocated blast and reverberatory

furnaces even at times when the facility ’s blast furnace is not operating. **Response :**  The commenter is correct that reverberatory furnaces that are collocated with blast furnaces are subject to the standards for collocated reverberatory and blast furnaces even at times when the facility ’s blast furnace is not operating. When the blast furnace is not operating, the emissions should be less than the combined emission s from the mixed exhaust produced with both furnaces operate. The reverberatory furnace will thus operate well within the limit for collocated furnaces when the blast furnace is not operating. **Comment :**  Commenter 95 expressed support for the EPA ’s proposal to establish emission standards for organic HAP and dioxins for reverberatory and rotary

furnaces. The commenter believes that the EPA is exercising a mandatory duty in addressing these emissions. **Response :**  We acknowledge the support. **Comment :**  Commenter 98 stated that the EPA failed to give a reasoned explanation for not proposing a stronger standard for dioxins and furans, to provide an ample margin of safety44

for public health. The commenter notes that the EPA identified a control that coul d lead to greater risk reduction

– the installation of additional afterburner capacity . The commenter stated that the EPA did not calculate the cancer risk reduction that would occur if the EPA required these emissions reductions. Instead, it relied on the Benzene Rule’s 100

- in

- 1 million presumption to conclude that emissions reductions would reduce cancer risk to a level that is “clearly less than” that benchmark. The commenter contends that section 112(f)(2) requires the EPA to consider additional redu ctions to provide an “ample margin,” not just the bare minimum amount of protection for public health. The commenter further stated that the potential for increased emissions of NO x and CO 2 is not a relevant factor or valid justification for not requiring HAP reductions under § 112. **Response :**  The EPA believes it is appropriate to maintain the benzene NESHAP decision framework for determining risk acceptability
. See section 112 (f)(2) (B) adopting that decision framework into the section 112 (f) decision process. Under the Benzene NESHAP we strive to limit to no higher than approximately 1
- in

- 10 thousand (100 in a million) the estimated cancer risk that a pers on living near a plant would have if he or she were exposed to the maximum pollutant concentration for 70 ye ars 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 taking into account cost, feasibility of controls , and non

- air impacts
. Inthis regard, EPA certainl y may consider if there are collateral environmental impacts of controls, including increased emissions of other air po llutants, or energy implications and attendant emissions of CO 2 air pollution. These are, in fact, among the “other relevant factors” which EPA may

consider. See section 112 (f)(2)(A). (Indeed, the commenter’s construction would lead to the anomaly that further controls could lead to adverse health or environmental impacts which EPA would have to disregard

– this when implementing a provision whose ultimate purpose is to protect against such risks.) Results of the multipathway risk assessment supportin g the proposed rule indicate d that the cancer MIR associated with dioxin and furan emissions was 30
- in

- 1 million, within (in fact below ) the acceptability

threshold from the Benzene NESHAP. As required in the ample margin of safety anal ys is, we did evaluate a control option that would further reduce emissions of dioxins and furans , but we determined those controls to not be cost

- effective
. 76 FR at 29050/3. In addition, we note that a recent stack test submitted by Exide Frisco (i.e., the facility with the multipathway

MIR of 30

- in

- 1 million at proposal ) during the public comment period show that45

emissions of dioxins and furans from this facility are in fact approximately 70 times lower than the emissions used as inputs used in the multipathway risk asses sment. Taking this into consideration, we believe that the multipathway MIR for this facility

would be appreciabl y less than 1

- in

- 1 million. Moreover, the cost effectiveness of use of an afterburner remains quite high as it was at proposal ($105,000/gram reduction). Use of high temperature afterburners to control a modest additional increment of dioxin not only has very poor cost - effectiveness, but has adverse environmental impacts in the form of increased NO x emissions, and increased energy use with attendant CO 2 emissions. 76 FR at 29050/3. Taking all these factors into consideration, we maintain that it is not appropriate to require further control to provide an ample margin of safety. Moreover, this same analy sis supports not adopting beyond

- the

- floor standards for CDD/CDF pursuant to section 112 (d)(2) and makes it unnecessary to have further control under section 112 (d)(6). The EPA also disagrees with the commenter that such factors as energy use, and increased NO x and CO 2 emissions, are irrelevant in making determinations under section 112(d)(6). Technologies with ultimate adverse environmental implications do not have to be regarded as ‘best’ o r ‘maximum’. See Essex Chemcial Corp. v. EPA , 486 F. 2d 427, 439 (D.C. Cir. 1973); Portland Cement Assn v. Ruckelshaus , 486 F. 2d 375, 385 n. 41 (D.C. Cir. 1973). Moreover, the fact that the EPA must consider “energy requirements” in adopting standards under section 112(d)(2) makes it reasonable to review tho se requirements when conducting further anal ys is pursuant to section 112(d)(6). Adverse environmental implications of additional energy use are an aspect of that consideration. **Comment :**  Commenter 98 stated that the EPA failed to carry out a technology

re view for THC emissions from the category . The commenter notes that the EPA clearl y states that “[n]o changes are being considered in this action for the THC limits for blast and collocated last and reverberatory

furnaces established in the 1997 NESHAP.” The commenter contends that this omission fails to satisfy section 112(d)(6). **Response :**  In the technology review conducted for this source category , the EPA did consider additional controls for organic HAP emissions
. As described in the Technology Review for the Secondary L ead Smelting Source Category document at page 8 ( available in docket ID EPA
- HQ
- OAR
- 2011
- 0344) , we did not identify new control technologies that would achieve reductions in organic HAP emissions beyond the limits consid ered in the current NESHAP. However, we d o believe that facilities may be able to achieve additional reductions in organic HAP emissions by

designing and operating an afterburner with a higher temperature and46

residence time. However, because the reverberatory furnace often operates at temperatures higher than those that can be reasonabl y achieved by an afterburner, this option is only feasible for blast furnaces. The EPA considered additional afterburner capacity for blast furnaces as a beyond

- the

- floor option for organic HAP, but decided against requiring this control after a consideration of potential emission reductions, cost, and non

- air environmental impacts. The beyond

- the

- floor option would achieve roughly 300 tpy in reductions of THC. However, thi s option would impose about $2.9 million dollars total annualized cost on the industry and achieve no significant environmental benefit or reductions in public health risks. The adverse energy implications associated with operating an afterburner, with att endant carbon and NO x pollution, also makes this an undesirable option. c. Mercury **Comment :**  Commenter 98 states that Section 112(d)(6) and 112(d)(3) each require the EPA to set a numerical limit for mercury emissions. The commenter stated that it is necessary for the EPA to close inherently unlawful gaps in the original MACT by setting a standard for an uncontrolled HAP and that the EPA must set an emission standard for each HAP listed on the section 112(b)(1) list that this source category emits, including mercury . The commenter argued that the EPA ’s own test showed that , for 32% of the data set, mercury emissions were above the detect ion level; therefore , the EPA did have and did use some information on mercury emissions to perform the risk assessment. The commenter suggests that the EPA could set the MACT limit using the data it used to perform the risk assessment for those sources w ith emissions below the detection threshold. Additionally the commenter stated that the EPA has failed to demonstrate that this proposal provides an ample margin of safety for public health from mercury emissions. **Response :**  EPA did not set a standard for mercury in the original MACT rule and is rectifying that deficiency (see National L ime , 233 F. 3d at 634) here b y establishing standards pursuant to sections 112 (d)(2) and (3). The commenter further maintains that it is impermissible to establish a work practice standard because the criteria under section 112 (h) aren’t satisfied since emissions of mercury from these sources were measured in a limited number of instances. Section 112 (h)(1) and (2)(B) indicate that EPA may adopt a work practice standard rather than a numeric standard when “the application of measurement methodology to a particular class of sources is not practicable due to technological and economic limitations.” The majority

of the mercury

data collected during the I CR test program for this rulemaking was below the limit of analy tic detection. Under these circumstances, EPA does not47

believe that it is technologically and economically practicable to measure mercury emissions from this source category . “ [A] pplication of measurement metho dologies” (section 112 (h)(2)(B) ) means more than taking a measurement. It must also mean that a measurement has some reasonable relation to what the source is emitting, i.e. that the measurement yields a meaningful value. That is not the case here and E PA therefore does not believe it reasonable to establish a numerical standard for mercury in this rule. Moreover, a numerical limit established at some level greater than the detection limit (a necessity since an y numeric standard would have to be measurab le) could actuall y authorize and allow more mercury to be emitted than would otherwise be the case. Mercury control can occur as a “ cobenefit ” of conventional control technologies that have been installed for other purposes. Particulate

- bound Hg can be ef fectively removed along with other flue gas PM (including non

- Hg metal HAP) in the primary PM control device. Fabric filters (FF) have been shown to provide very high levels of control when there is adequate halogen (or other oxidant) available to convert the Hg to the oxidized form. See 76 FR at 29051 and Control of Mercury Emissions from Coal Fired Electric Utility Boilers , available at http://www.epa.gov/ttn/atw/utility /utiltoxpg.html . The stack emission standard for lead is predicated on optimized performance of a well

- maintained new baghouse. We thus believe that this standard will also result in the level of control of the exceedingl y small amounts of mercury present in secondary lead emissions achieved b y the best performing facilities in the source category
. **Comment :**  Commenter 90 and 96 support the EPA ’s reasoning and conclusion that no work practice requirements for mercury are appropriate or necessary . The commenters do not believe that the data confirm that mercury is actually

emitted by

the industry. **Response :**  The test data do indicate that a small amount of mercury is emitted from this industry , however, as described above, a numerical standard for this pollutant is not warranted
. **3.2 Risk Assessment**  **3.2.1 Risk Assessment Methodology**  **Comment :**  Two commenters ( 80, 86 ) support the use of CalEPA’s acute RELfor arsenic.**Response :**  We acknowledge the support.48

**Comment :**  Two commenters ( 86 , 92 ) commended the EPA for using allowable emissions in its risk assessment for this source category
. **Response :**  We acknowledge the support
. **Comment :**  Two commenters ( 86 , 92 ) commended the EPA for conducting multipathway

exposure and risk modeling for those HAPs known to be per sistent and bio

accumulative in the environment and for selecting facilities that represent the high end of potential risks from this source category
. **Response :**  We acknowledge the support
. **Comment :**  Commenter 92 stated that they were satisfied with many aspects of the residual risk assessment. According to the commenter, the strengths of the risk assessment were,

 The use of facility

specific emission point parameters,
 The review and use of emissions data from stack testing reports;
 The inclusion of allowable emissions when predicting risk under the proposed risk assessment,
 The inclusion of an analysis of the pre

- and post

- emission control impacts on the MIR
 The assessment of the available ambient lead monitori ng data collected in the vicinity of these facilities, and
 The effort to conservatively assess the impact of fugitive emissions in a sound technical manner that goes beyond what other residual risk assessments have achieved. The commenter also stated that they agree with the use of the lead NAAQS with which to compare the predicted maximum modeled 3

- month average lead concentration as the NAAQS was “rigorousl y derived to protect public health with an adequate margin of safety.” **Response :**  We acknowledge the support. **Comment :**  Four commenters ( 80, 86 , 92 , 98 ) disagreed with the use of the census block centroid to determine risk from the facilities’ emissions. Commenter 86 argues that using the census block centroid to estimate risk “dilutes the effect of sources’ emissions by estimating the impact at the centroid of the census block instead of at the facility fence or the prope rty line.” Commenter 86 noted that in larger census blocks, the maximum point of impact can be far from the centroid . Commenter 86 f urther pointed out that non

- developed areas near the property line can become developed over time. Commenter 98 n oted that the center of a census block is almost alway s further away from the facility

than the fenceline. Commenter 98 stated that census bl ocks vary

greatly in size but the EPA provided no evidence of reviewing census block49

sizes or configurations to consider how pollutant concentrations might vary within these blocks. Commenter 98 is concerned that the area

- weighted centers of census blocks may significantl y underestimate exposure in some cases and recommends moving receptor points closer to the facility to assess chronic exposure in those instances where local residents live nearer to a facility than the geographic centroid of the census bl ock. All four commenters note d that HEM

- 3 gives the EPA the capability to identify that maximum individual risk at any point in a census block that is within a 50

- km radius from the center of the facility. In response to the above comments, two commenters ( 90 , 96 ) note d that the EPA “estimated the MIR associated with each facility by purporting to determine the risk associated with a lifetime exposure at the highest concentration outside the property boundary...” The se commenter s further noted that the census block centroid risk estimates were used onl y to “estimate population risks and that if EPA considered only the maximum individual risk in each census block, there would be no information from which to estimate populations risks.” **Response :**  As we have noted in the development of previous residual risk regulations, such as the HON, in a national

- scale assessment of lifetime inhalation exposures and health risks from facilities in a source category , it is appropriate to identify exposure locat ions where it may be reasonabl y expected that an individual will spend a majority of his or her lifetime. Further, in determining chronic risks, it is appropriate to use census block information on where people actuall y reside, rather than points on a fenc eline, to locate the estimation of exposures and risks to individuals living near such facilities. Census blocks are the finest resolution available as part of the nationwide population data (as developed by the US Census Bureau); each is ty picall y compris ed of approximately 40 people or about 10 households. In EPA risk assessments, the geographic centroid of each census block containing at least one person is used to represent the location where all the people in that census block live. The census block ce ntroid with the highest estimated exposure then becomes the location of maximum exposure, and the entire population of that census block is assumed to experience the maximum individual risk. In some cases, because actual residence locations may be closer t o or farther from facility emission points, this may

result in an overestimate or underestimate of the actual annual concentrations (although there is no s ys tematic bias for average levels). Given the relatively small dimensions of census blocks in densely

- populated areas, there is little uncertainty introduced by

using the census block centroids. There is more uncertainty when census blocks are larger, although there is still no systematic bias. Thus, the EPA concludes that the most appropriate locations at which50

to estimate chronic exposures and risks are the census block centroids because: 1) census blocks are the finest resolution available in the national census data, 2) facility fence lines do not ty picall y represent locations where chronic exposures are likely (i.e, people do not ty

pically live at the fence line of facilities) and 3) as just described above, there is no s ys tematic bias with respect to using census block centroids as an exposure surrogate for all individuals residing in that block. Thi s has been EPA’s approach for estimating chronic maximum individual exposures and risks throughout the RTR program. In addition, in its peer review of the methodologies used to estimate risks as part of the RTR rulemaking efforts, the EPA’s Science Adviso ry Board (SAB) endorsed this approach. **Comment :**  Two commenters ( 90 , 96 ) stated that the EPA should not use the CalEPA’s acute REL for arsenic because it is “invalid and substantially overestimates acute risks from arsenic exposure.” The commenters note d that the California REL relied on the Nagy

majten yi study which did not evaluate the fetal effects on a litter basis, therefore making it impossible to determine whether the observed effects were due to arsenic exposure or other litter effects. The comment ers cite d a similar study “that was conducted in accordance with appropriate guidelines” in which researchers observed no fetal effects at As 2 O 3 concentrations of 10 mg/m 3 . The commenters also state d that the fact that the California RELis approximately 100 times lower than that for arsine gas despite the fact that arsine gas is much more toxic than As 2 O 3 is anomalous. So too, according to the commenters, is the fact that despite the greater toxicity of arsine, a study conducted by the National Toxicology Program showed “no evidence of developmental toxicity

in either rats or mice at concentrations up to 2.5 ppm...” The commenter further noted that use of the California REL is “inconsistent with and w ould constitute a departure from EPA’s practice, which has considered a fetal weight reduction of 0.1 g to be not toxicologically

signific ant.” The commenter also argued that the California RELis inconsistent with ATSDR’s guidance, which deems 0.26 mg/m 3 to be a NOAEL rather than a LOAEL. The commenter stated that the EPA should either not attempt to quantify acute arsenic risks or should correct the California REL b y increasing it b y at least an order of magnitude, citing the Morrissey

study that sugges ts that the California REL should be set at a l evel at least 100 times greater than the current standard. Commenter 92 stated that the state of New York did not adopt the California REL because “it is policy

in New York to adopt the most stringent of eith er a non - cancer chronic or51

cancer air guideline concentration.” The commenter notes that New York multiplied the EPA ’s IR IS unit risk value for Arsenic of 2.3E

- 4 μg/m 3 by 65 to obtain a REL of 0.015 μg/m 3

. **Response :**  With regard to the acute Cal EPA REL fo r arsenic, the EPA recognizes that there are limitations associated with the database used in the derivation of this value. Nevertheless, given that the acute Cal EPA REL is the only existing peer

- reviewed acute dose

response value , the EPA considers it re asonable to use this value for an acute anal ys is. It is important to note that assessments of risks from acute exposures to HAPs represent wors t - case scenarios , and that the estimated acute impacts of arsenic did not weigh heavily in the regulatory decisi on . With respect to New York benchmark value for arsenic, we note that the EPA has a hierarch y of appropriate health benchmark values. In general, this hierarchy places greater weight on EPA derived health benchmarks than those derived b y other States or agencies (http://www.epa.gov/ttn/atw/nata1999/99pdfs/healtheffectsinfo.pdf)
. Moreover, multiplying a chronic IRIS cancer value by 65 to obtain an acute RELis an arbitrary approach that to our knowledge, has not received favorable scientific support or been subject to peer review. **Comment :**  Two commenters ( 90 , 96 ) claimed that the E PA ’s risk review violated section 112(f)(2) because it considered risk from sources that are not part of the secondary lead smelting source category . The commenters note d that by including facility

- wide emissions the EPA may overestimate risks associated with the secondary lead smelting industry

and promulgate risk

based standards for risks that are not attributable to its emissions. The commenter further stated that “it would be unlawful for EPA to use information from the National Air Toxics Assessment or otherwise to include non

- source category (or subcategory) risk in setting standards pursuant to Clean Air Act § 112(f)(2). The commenter similarly noted that by

proposing emission standards based on sources emitting lead at levels that exceed the NAAQS , the EPA is improperly considering background ambient lead concentrations in its analy sis. **Response :**  T he finding of unacceptable risk from the secondary lead smelting source category was based on risk estimates and emissions from the secondary lead sourc e category
. More specificall y, we found estimated risks resulting from secondary lead smelting emissions at these facilities to be unacceptable primarily based on source category emissions of lead compounds
. See 76 FR at 29054
- 29055. The finding of unacceptable risk was not based on emissions or estimated risks associated with the facility wide anal ys is
. In addition, we disagree with the comment that the EPA is “improperl y considering background ambient lead52

concentrations in its analysis
. ” The e stimates of lead risk in the risk assessment, as well as the controls in the final rule, are based solel y on emissions from the facilities in the secondary lead smelting source cate gory . They do not take into account additional sources that may be outside the source category

contributing to ambient lead background concentrations
. **Comment :**  Four commenters (90, 91, 94, 96) argued that the EPA ’s risk review is invalid because it is predicated on risks to h ypothetical populations that may not exist. The comm enters cite d the specific example of the EPA ’s estimated multipathway risk to Laotian anglers near the Exide Technologies facility in Frisco, Texas. The commenters contend that census statistics indicate that the Laotian population in this area of Texas i s very small and that the EPA should demonstrate that there are actually Laotian anglers who consume fish from Lewisville Lake. Commenter 94 stated that, in the case of the Laotian anglers, multiple layering of conservative assumptions result in an unreali stic and overstated estimate of risk. The commenter further stated that there is no evidence that particular groups in Texas eat exceptionally high amounts of fish. Moreover, even ethnic groups that eat high amounts of fish will not continuously

eat exclusively

fish from one corner of Lewisville Lake for 70 years. The commenters also stated that the EPA ’s risk assessment erred in its estimate of fish concentrations in Silver Lake near the RSR facility in Middletown, NY. The EPA stated in its risk assessment that Silver Lake is too small to support fishing unless it is stocked regularly . The commenters note d that stocking reduces the exposure period for fish and decreases expected fish tissue concentrations relative to lakes where fish are not stocked. The commenters further note d that there is no indication in the risk assessment that the EPA has considered this factor in their risk calculations. **Response :**  We agree with the commenter that some of the risk estimates presented in the multipathway

anal ys is reflect conservative assumptions. As noted in the risk assessment document, in order to more full y characterize the potential multipathway risks associated with high end consumption of PB

- HAP contaminated food, we present results base d on reasonable maximum exposure ( RME ) and central tendency estimate ( CTE ) scenarios. The RME scenario utilizes 90th percentile ingestion rates for farmers, recreational anglers, and for three subpopulations of recreational anglers) who have higher rates of fish consumption (Hispanic, Laotian, and Vietnamese descent), while the CTE scenario utilizes mean ingestion rates for each of these groups. We provide results from both scenarios to illustrate the range of potential53

modeled exposures and risks that may exist in the high

- end of the complete distribution of potential multipathway

risks for this source category . In addition, the risk assessment document also notes the risk range for the entire distribution of recreational anglers , which have significantl y lower rates of fish consumption than the three sub populations mentioned above
. Thus, in order to estimate a distribution of potential multipathway risks, we think it is reasonable to consider fish ingestion rates across multiple groups, including the La otian population
. Moreover, we note that it is entirely possible that individuals other than Laotians may consume fish at an y of the ingestion rates described in the multipathway assessment . This again supports the use of a range of ingestion rates in order to estimate a broad range of potential multipathway risks. We further note that based on updated emissions estimates from the Frisco, TX case study facility , we now estimate that all multipathway risks from both case study facilities are less than 1
- in a million (see final risk assessment document section 3.2). With respect to the comment that Silver L ake is too small to support fishing unless it is stocked regularly , we note that the TRIM.FaTE model does not currently model fish population dy namics, including processes like birth, death, growth, and stocking, although it does account for predation. Because the model estimates long

- term concentrations in fish, it is unlikely that introducing changes to account for stocking would substantially impact th e calculated PB

- HAP concentrations in adult fish, especiall y if the fish are assumed to be stocked as fingerlings. **Comment :**  Three commenters ( 90 , 91 , 96 ) disagree d with the use of the lead NAAQS as a hazard index. The commenters argue d that the lead NAAQS was based on only risks to young children, and that the EPA has inappropriately concluded that exceedances of the lead NAAQS result in unacceptable risks to adolescents and adults. The commenters contend that hazard indices should not be presented in Tables A

- 5 through A

- 8 of the demographics anal ys is for age groups other than young children. **Response :**  If the commenter is arguing that the proposed, and now final, standards for lead provide too much protection because they protect susceptible populations

– notably young children living near lead emitting sources

– and thus provide too much protection to other exposed individuals, this argument has been sharply rejected in the section 109 (d) NAAQS context (see Coalition of Battery Recycl ers , 604 F. 3d at 617

- 18) and is just as misplaced here where EPA is charged to provide an ample of margin o f safety in setting standards. Given that lead is a non

- threshold pollutant, it is reasonable to use a metric for evaluating acceptability of risk which is based on assuring that the most susceptible sub

- population is not exposed to54

unacceptable risk and thereb y assuring that less susceptible populations are likewise not exposed to unacceptable risk. In addition, w e disagree with the commenter that th e lead NAAQS cannot be used in a quantitative manner. The review of the lead NAAQS clearl y resulted in a quantitative standard: 3
- month maximum lead concentration not to exceed a level of 0.15 μg/m 3 . This standard was set to protect public health, includin g the health of sensitive populations (i.e., children) , with an adequate margin of safety . As the commenter notes, the lead NAAQS applies in all areas of the United States regardless of the age of the individuals living in a particular area. Thus, we find it appropriate to evaluate potential multipathway risks, in a quantitative manner, using the NAAQS for lead. **Comment :**  Five commenters ( 90 , 91 , 94 , 96 , 111 ) disagreed with the use of MACT

allowable emissions to estimate risk. The commenters argue d that the purpose of reviewing emissions under section 112(f)(2) is to assess the actual risks to people living near facilities in this source category . Commenter 91 noted that “Nothing in § 112(f)(2) allows EPA to replace the statutory

directive to exami ne what health risks are present at actual emission levels with a risk assessment that asks what health risks might be present a maximum allowable emission levels.” Commenter 91 further stated that less stringent rules would have likely been required had the EPA relied onl y on actual emissions to conduct its risk assessment. Commenter 94 contends that even if allowable emissions are used for the risk assessment, the EPA should consider all applicable permit and legal limits on emissions. The commenter sp ecifically cited Exide’s Frisco, Texas and Vernon, C alifornia facilities that are subject to more stringent limitations than what is specified in the NESHAP. Based on the commenter’s calculations, the EPA has overstated the allowable emissions at the Fris co and Vernon facilities by factors of three and 100, respectively . Commenter 111 stated that the EPA ’s failure to provide a reasoned explanation as to why

using MACT

- allowable emissions to calculate risk is justified renders the proposal insupportable un der the law. The commenter stated that the EPA ’s risk assessment already reflects num erous conservative assumptions and that applying another layer of conservatism based on the hy pothetical assumption that affected sources should be expected to emit more than the data indicates is not reasonable or justified. The commenter points out that the EPA ’s own anal ys is indicates that all the facilities in this source category emit significantl y less than what is allowed under the current MACT standard.55

**Response:** 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 th e NESHAP requirements) is inherentl y reasonable since they

reflect the maximum level sources could emit and still comply with national emission standards. Quite simply , in determining whether unacceptable residual risk remains after promulgation of sectio n 112 (d) technology

- based standards, it is reasonable to consider the emissions allowed by those standards. But we also explained that it is reasonable to consider actual emissions, where such data are available, in both steps of the risk anal ys is, in ac cordance with the Benzene NESHAP. With regard to the comment that we failed to incorporate permit limits imposed on two facilities, we evaluated residual risk from allowable emissions remaining after compliance with the Secondary L ead Smelting NESHAP rathe r than permit limits that were, as the commenter say s, more stringent than the requirements of the NESHAP. **Comment :**  Commenter 80 stated that area sources should be modeled as area sources rather than “pseudo point sources.” The commenter contends that forcing area emissions into point source “distorts their impacts on ambient concentrations.” **Response :**  Table 2.2

- 1 of the risk assessment document contain ed a ty pographical error. Area sources are modeled with a length, width and any other available charac teristics at the proper location, not as point sources. This table has been corrected in the final risk assessment. **C omment**  **:** Commenter 80 stated that the use of a polar grid reduces the number of modeled receptors and makes it much less likely that the ac tual maximum concentration and location is modeled. **Response :**  We disagree with the commenter that the use of a polar grid reduces the number of modeled receptors and makes it much less likely that the actual maximum concentration and location is modeled. We note that the polar grid used in our exposure modeling utilizes a greater concentration of receptors in locations in close proximity to a given facility . Thus, we have the greatest concentration of model receptors in areas where we would expect the sit e of maximum concentration to occur. As a result, we believe that our polar receptor grid is sufficiently dense to capture the site of maximum concentration.56

**Comment :**  Commenter 80 questions the use of meteorological data from 1991. The commenter conte nds that there is ample data from more recent years and that improvements in the number and quality of meteorological instruments over the ye ars makes using data that is twenty years old inappropriate. **Response :**  When we began performing RTR risk assessment s, we chose meteorological data considering the amount of data quality assurance needed, and AERMOD run times. We restricted our meteorological data to that collected prior to the installation of the Automated Surface Observation Sy stem (ASOS). The ASOS h ad been found to omit the ceiling height for a large percentage of the observations at a number of meteorological stations. Because installation and operation of ASOS equipment began in 1992, we selected the ye ar 1991. As newer, higher quality ASOS data have become available, we have added newer data and additional data site locations to the meteorological data library we use in our risk assessments. Currently , approximately

fort y percent of our data is for years since 2000, and we will continue to proce ss and add more recent data. The commenter did not provide evidence regarding their comment questioning the quality of meteorological instruments. Although five ye ars of meteorological data is preferred for assessing chronic exposures and risks, we use a single year of meteorological data in our risk assessments because of AERMOD model run times. Because we frequently run AERMOD for entire source categories with many

individual emission points and for many receptors, using five years of meteorological dat a would increase already significant model run times by a factor of five compared to a single ye ar. In a sensitivity

analy sis of the impact of using a single ye ar of meteorological data compared to five years, we found that modeled concentrations differed by less than ten percent on average and thus, the use of one ye ar of meteorological data is not likely to appreciabl y affect the results of the risk assessment
. **Comment :**  Two commenters ( 86 , 92 ) questioned why certain factors recommended by the EPA in the EJSEAT were not considered in the risk assessment for this industry . Commenter 086 stated that the EPA should consider addressing existing disproportionate impacts on minority , low

- income or indigenous populations during rulemaking. Commenter 86 further recommended that the EPA conduct a full evaluation of how the risk assessment for this source category could reduce risks to those communities. Commenter 92 stated that the evaluation should have included an assessment of childhood blood

- levels in neighborhoods near the smelters.57

**Response :**  We note that EJSEAT is currently a draft tool in development. The EPA disagrees that a full assessment of child blood

- levels should have been included in its risk assessment. We note that the NAAQS for lead was used as a health benchmark value in our risk assessment and in developing the NAAQS for lead, child blood

- lead levels were already taken into account. See section V.A in the final rule preamble and later responses in this document. Moreover, we also note that we did a demographic anal ys is for this source category and with respect to lead risk , we found that the percentages of specific demographic groups (e.g., minority groups, those below the poverty level) living around these facilities in areas with lead concentrations above the NAAQS for lead is similar to the corresponding national percentages for these groups. In addition, w e per formed a similar anal ys is with respect to cancer risk above 1 in a million
. Inbrief, although we did find the percentage o f some demographic groups around these facilities with cance r risks above 1 in a million to be higher than their corresponding national percentages (e.g., a greater percentage of minorities and those below the poverty level live around secondary lead facil ities and have a cancer risk greater than 1

- in a million compared to the national percentages for these groups ; see Risk and Technology Review

- Anal ys is of Socio

- Economic Factors for Populations L iving Near Secondary L ead Smelting Facilities in the docke t for this rule ) , we note that post

- control cancer risks were substantially reduced for all demographic groups. For example, the pre control MIR was estimated to be about 5 0 in a million, but the post

- control MIR was reduced to 7 in a million (see Residual Risk Assessment for the Secondary

L ead Smelting Source Category available in the docket for this rule). More important, what matters is whether persons of whatever demographic exposed to emission s from secondary lead smelters would experience an unacceptable level of risk. The rule will result in lead exposures which are less than the lead NAAQS and substantially reduced cancer risks. The NAAQS is itself predicated on being protective with an adequate margin of safety to the most susceptible sub

- population: children living near these sources who are exposed at the level of the standard . The NAAQS accounts for multi

- pathway impacts of long

term emissions, as well as the differential incremental risk of Pb faced b y populations at different levels of exposure. See section V.A of the final rule preamble and later responses in this document . These standards will therefore reduce risk of exposure to an acceptable level to all groups. **Comment :**  Three commenters ( 90 , 94 , 96 ) argued that the EPA should more clearl y state the conservative nature of its risk assessment. Commenters 90 and 96 stated that the EPA58

overestimated the cancer incidence for population living around the smelters. The EPA estimates cancer incidence b y multiplying the estimated canc er risk for each census block by the number of people living within the block. Cancer risk for each census block is estimated by multiplying lifetime average exposure by a Unit Risk Exposure (URE). The commenters contend that because cancer incidences are calculated on the basis of these URE’s, the cancer incidences are upper bound estimates that may be lower than predicted and could be zero. The commenter requested that the EPA clearl y identify the cancer incidence estimates as upper

- bound estimates and explain that actual cancer incidence could be as low as zero. Commenter 94 stated that the EPA should not make and layer conservative assumptions that yield risks that are clearl y out of line with an y risk faced in the real world. The commenters cite d th e EPA ’s use of the maximum exposed individual (MEI). The commenter contends that the use of the MEI alone results in an overestimation of cancer risks b y at least a factor of thr ee. The commenter further cited the Superfund context in which the EPA “reco gnizes and places limits on the applications of conservative estimates...” The commenter stated that the EPA should make clear the conservative nature of its assumptions and should also adopt a risk assessment approach that meets the Superfund reasonable maximum exposure (RME) definition. **Response :**  The EPA disagrees with the commenter that it does not describe the nature of its risk assessments, including their limitations, uncertainties, and the possible interpretations of results. In deed, in this proposed rule and in the risk assessment documentation accompanyi ng it, as in all RTR rulemakings, there are length y sections discussing the uncertainties associated with each step of the assessment process , including justifications for health

- protective assumptio ns to cover uncertainty gaps, where appropriate . As one example , the risk assessment clearl y states cancer incidence estimates are upper bound and actual cancer incidence could be as low as zero. The risk assessment states in section 2.7: For each carcinogenic HAP included in an assessment that has a potency estimate available, individual and population cancer risks were calculated by multiplying the corresponding lifetime average exposure estimate by the appropriate URE. This calculated cancer ris k is defined as the upper

- bound probability of developing cancer over a 70
- yrperiod (i.e., the assumed human lifespan) at that exposure. Because UREs for most HAPs are upper

- bound estimates, actual risks at a given exposure level may be lower than predic ted, and could be zero. The EPA further notes that it does not currentl y use the maximum exposed individual (MEI) metric i n its chronic risk assessments , instead using the maximum individual risk (MIR)59

metric for the source category

- - which is defined as the cancer risk associated with a lifetime of exposure at the highest concentration s associated with carcinogenic HAP emissions from the source category
. The MIR is estimated at a location where people live, whereas the MEI is estimated at a location on the property boundary of a facility (see section 2.3 of the final risk assessment for a description of the MIR and section 4.1 for a description of uncertainties associated with the MIR estimate)
. See section 112 (f)(2)(A) allowing such an approach by its reference to “the individual most exposed to emissions from a source in the category” which can certainl y be read to refer to lifetime exposure where people reside. Put another way, in assessing chronic risk, it is more reasonable to assess risk b ased on where people may reside for 70 ye ars, than to assume exposure for 70 years at a location (a property fenceline) where people do not reside for a lifetime
. **Comment :**  Commenter 92 states that the EPA should have conducted the socio

economic analy sis separately for each of the 14 secondary lead smelting facilities, rather than combining the outcome for all the facilities. **Response :**  The EPA disagrees that it should have conducted the socio

- economic anal ys is separately for each of the 14 secondary lead s melting facilities, rather than combining the outcome for all the facilities. As noted in the preamble and demographics anal ys is, the purpose of the demographics analysis was to identify demographic groups that may be impacted by

the proposed rule. For this purpose, the EPA believes that a source

- category wide socio

- economic anal ys is is a reasonable approach. **Comment :**  Commenter 91 questioned several aspects of the air dispersion modeling conducted b y the EPA , including:

 Failure to account for dry depleti on.
 Failure to include building profile data in downwash calculations.
 Using one degree rather than 7.5 minute to estimate ground level and hill height elevations close to a source.
 Failure to rel y on actual boundary data.
 Mischaracterizing the stack height and diameter and exit temperature and location of two sources at the Doe Run facility
.  Modeling fugitive emissions with a release height of 10 feet rather than as being emitted from a building that is 80 feet high.
 In cluding results from two monitors loc ated within Buick Recycling’s fence line and relying on a three

- month average lead concentration level that occurred during upset condition.60

 Lack of clarity regarding whether allowable emissions incorporated enforceable emission restriction that are currently in place. **Response :**  We agree that accounting for dry depletion would result in lower estimated air concentrations. However, the impact of dry depletion on gaseous emissions is usually not significant, and for particulate emissions the impact depends on multiple factors, inc luding the distance from the source to the receptor, and particle properties. The impact of depletion on maximum estimated air concentrations and risks likely would be minimal because of the short distance between the sources and receptors. At longer dis tances, the impact would be greater, but the extent of that impact is difficult to estimate because we typicall y do not have sufficient particle property data (aerodynamic particle diameters, particle densities, and mass fractions) to model depletion. Als o, deposited emissions can be resuspended in the air, and plume depletion does not account for that. We agree that, in certain cases, building downwash can result in higher estimated air concentrations near buildings (up to five to ten building heights away) . However, the impact of downwash on maximum estimated exposures and risks is likely not significant because the receptors we use to estimate chronic exposures (populated census block centroids) are typically farther from the source. Downwash would have an even lower impact on cancer incidence and population risks because those are driven b y receptors even farther from the source. Also, the detailed building information required to model building downwash is usually not available for most sources. For RTR risk assessments, we have used 1

- degree elevation data, which has a resolution of approximately

90 meters. We used this elevation data to compute the elevation and hill height scale for each populated census block (2000 Census) in the nation, which i s approximately six million blocks. This was done over a decade ago, and at that time, EPA's modeling guidance (40 CFR 51, Appendix W) did not require the use of 30

- meter resolution data for regulatory applications. We used the 1

- degree data because of its availability and because of computational efficiencies with interpolating the data for the approximately six million census blocks. For future RTR assessments, we will use the 2010 Census data and 30

- meter resolution elevation data. Detailed facility boundary information is ty

picall y not available for most of the sources we assess for RTR, but the lack of this information does not have a significant impact on our risk assessments. For chronic exposures, we use populated census block centroids as surro gates for61

where people live, so facility boundaries are not relevant. For acute exposures, we estimate the highest concentration outside facility boundaries, and boundary information would be useful. In cases where estimated acute concentrations exceed relevant health reference values, we do need some source of information on facility boundaries, and we t ypicall y use publicly available aerial images of facilities for this purpose. Similarly , for lead we also estimate the highest concentration outside fac ility boundaries and in instances where the NAAQS for lead is exceeded, we ty

pically use publicly

available aerial images of facilities for further refinement of concentrations. Finally , we note that the mischaracterized stack dimensions and exhaust temperatures at the Doe Run facility which were mischaracterized at proposal have been corrected and are reflected in the results of the final risk assessment document (see sections 3.2 and 3.3 as well as Appendix 5 of the final risk assessment document for updated risk estimates)
. We have noted the commenter’s point that two of the monitor locations listed in the Summary of the Ambient Lead Monitoring Data near Secondary Lead Smelting Facilities were located on the facility

property , and a corrected version ha s been included in the docket for this final rule. We did not incorporate facility

- specific permit limits that differed from the requirements of the secondary

lead smelting NESHAP into the risk assessment. The assessment of allowable emissions focused on what is allowable after implementation of the NESHAP rather than facility

- specific permit limits that may have been put in place for compliance with other regulations. **Comment :**  Commenter 94 stated that the EPA’s estimate of risk to farmers near the Exide Frisco facility is unrealistic. The commenter noted that the 2001 land data that the EPA used to assign locations to the farms did not account for development that has occurred near the facility in the last decade. Given the level of development that ha s occurred, the commenter contends that it is unlikely that the level of farming needed to provide all of a person’s food would continue around the facility for 70 ye ars into the futur e. The commenter further argued that the assumption that a single indiv idual is exposed via all pathway s is unrealistic. **Response :**  To characterize the surrounding land use for the Exide Frisco facility , EPA used the 2001 National Land Cover Database (NLCD) from the U.S. Geological Survey . In late 2010 (i.e., November/December), when assigning input parameter values for the secondary lead smelter so urce category

risk assessment, EPA reviewed Google Earth satellite imagery to ensure62

that the characterization based on the 2001 data still appeared to be reasonable. Based on that review, EPA determined that the 2001 data adequately represented the surro unding land use of the Exide Frisco facility . Although Google Earth does not provide the resolution necessary to quantify the land uses surrounding the facilit y in sufficient detail to use in TRIM.FaTE, the resolution is adequate to see areas of undevelop ed land that appeared to be dedicated to agriculture (i.e., appeared to be either tilled or in pasture). Additionall y, in November 2011, Google Earth was reviewed to respond to this comment, and based on an image dated March 31, 2011, the characterization of the farmin g scenario was still possible. However, as noted above, based on updated emissions estimates from the Frisco, TX case study facility , we now estimate that all multipathway

risks from both case study facilities are less than 1

- in a million (se e final risk assessment document section 3.2). EPA acknowledges that it is unlikely that an individual would be exposed to contaminants from emissions from this facility for an entire 70

- ye ar lifetime. However, to be protective of health, EPA assumes that a child grows into an adult in the vicinity of the facility and is exposed for their lifetime (i.e., exposure duration of 70 years). This default assumption is used unless there is clear justification to vary the exposure duration. EPA acknowledges that there has been development in the vicinity of the Exide Frisco facility and this development likely will continue. However, that facility was modeled to encompass one of the likel y wors t case scenarios possible for the source category based on data for al l of the facilities in the source category . Moreover, even at the Exide Frisco facility , as noted above, there is still the potential for agricultural production and subsistence consumption patterns in the vicinity
. EPA also acknowledges that it is unl ikely that one individual would be exposed to all of the ingestion pathway s modeled in this assessment in the vicinity of the Exide Frisco facility for an entire lifetime. However, EPA believes that the possibility exists, however remote, and in the absen ce of information suggesting otherwise, makes this health protective assumption. Such conservative assumptions are consistent with Agency policy for chemical risk assessment for which all existing and potential future facilities cannot be assessed. Use of these assumptions in national

- level risk assessments has been reviewed by the National Academy

of Sciences and EPA’s Science Advisory

Board. **Comment :**  Commenter 98 noted that the EPA stated that it has p erformed no risk assessment for some HAPs due to the fact that they have no peer

- reviewed reference values for cancer or chronic non

- cancer or acute effects. The commenter stated that the EPA cannot simply63

ignore these risks and must, at minimum, add an uncertainty factor to account for the risk that the se HAP may

cause. The commenter further stated that the EPA should “prioritize those HAPs for which it needs data in this rulemaking and the next upcoming rulemakings and ensure that the development of this process and IR I S review have sufficient funding and resources to get the job done.” The commenter contend s that the EPA must set a regulatory deadline to review the current risk anal ys is and perform another residual risk rulemaking once additional data on reference values becomes available. The comment er also stated that the fact that the EPA did not state which HAPs currentl y have no reference value denies commenters the opportunity to provide comments or information to the EPA that could improve its risk assessment and is a violation of the Clean Air Act’s public notice and comment provision. **Response :**  This issue was addressed b y the EPA’s Science Advisory Board (SAB) in their May 10, 2010, (EPA

- SAB
- 10
- 007) response to the EPA Administrator; http://yosemite.epa.gov/sab/sabproduct.nsf/4AB3966E263D943A8 525771F00668381/$File/EPA

- SAB
- 10
- 007
- unsigned.pdf. In that response, the SAB Panel recommended that, for HAPs that do not have dose

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

- response values into the EPA’s hierarchy should be adequately

documented in a transparent manner in any residual risk assessment case study . We agree with this approach and have considered other sources of dose

- response data when conducting our risk determinations under RTR. However, in some instances no sources of information in addition to the EPA’s hierarch y are available. The EPA agrees that we should ultimately develop toxicity

values for all Hazardous Air Pollutants (HAPs) utilizing all credible and relevant toxicity information. The need to update assessments with newl y available data as well as the need to complete toxicological assessments for all HAPs lacking dose

- response assessments further increases the importance of Agency activities to streamline and fully utilize the EPA’s already overloaded IRI S program. To that end, the EPA has alway s pri oritized for future IRIS assessments those HAP without dose

response values but with the greatest potential for public exposure. As a result of this prioritization, while not all HAPs may have scientifically

accepted dose

- response values that can be used in residual risk assessments, it is clear that the vast majority of HAPs which might carry64

the potential to significantly impact the results of residual risk assessments do, in fact, have credible dose

- response values. Thus, while we are not yet at the po int where all HAPs have dose

- response values, we are generally capable of deriving reasonable risk estimates for those HAP which dominate the risks from an y one source category . In the course of each residual risk assessment, should we encounter HAP witho ut dose

- response values which carry the potential to create significant risks, we shall clearly point those out as uncertainties and target them for future IR IS assessments. Moreover, as additional dose

- response values become available, the EPA will incor porate these dose

- response values into future risk assessments. The EPA disagrees that with the commenter that we did not state which HAPs currentl y have no reference value. In the risk assessment document, Table 3.1

- 1 lists all the HAP emitted by the source category , as well as whether there is an available cancer, chronic noncancer, and/or acute dose

- response value. **Comment :**  Commenter 98 stated that the EPA underestimated risk to the most vulnerable populations by failing to account for the incr eased susceptibility of children and the developing fetus to HAP exposure. The commenter stated that accounting for the increased susceptibility

of infants and children to pesticides is required for risk assessments conducted under the Food Quality

Protec tion Act and that the EPA should use this statute as a model to incorporate into its residual risk assessment. The commenter contends that the EPA should “assume that the maximum exposed individual is a child or pregnant woman, conduct an evaluation of he alth risks that incorporates impacts from earl y life exposure, and set child

protective standards.” The commenter further maintains that the primary lead NAAQS is an inappropriate measure of acceptability

of risk “because it ignores the cumulative, long

- te rm impacts to individuals in the local affected communities from prior lead emissions”. The commenter maintains that “the CAA requirements for the level of a NAAQS are different from the standard for residual risk. What is acceptable at the population leve l is not necessarily

acceptable at the community level.” More specificall y, the commenter assert s that “EPA must set a standard for those people living near facilities subject to the MACT who were left with insufficient protection... It is these specific communities near the facilities and the children living in these communities, and not a broad U.S. sub

- population, that must be protected... The fact is that the lead NAAQS does not sufficiently protect people living near secondary lead smelters.”65

The comment er further states that “i n addition, replicating the lead NAAQS as an ambient standard is especially

problematic because it ignores the cumulative, long

- term impacts to individuals in the local affected communities from prior lead emissions that have occur red here and thus does not account for the full risk to communities near secondary lead smelters. EPA may not set a residual risk standard that primaril y addresses ambient air. Past lead releases likel y have created reservoirs of lead in the soils, vegetat ion, and dust in the area. ” Based on this, the commenter argues that “i f a community has a high level of lead in these other reservoirs, including the soil, there may well already

be too much existing risk, such that no additional new lead emissions shoul d be allowed to increase this risk .” With regard to lead emissions, the commenter stated that the EPA may not simply rel y on the lead NAAQS to protect children. The commenter stated that the EPA must incorporate the best available information, including the CHPAC recommendation and California’s current health benchmark for children’s blood

- lead level change. With regards to emissions of all HAP, the commenter stated that the EPA should examine d evelopments in the methodology of California’s Office of Environmental Health Hazard Assessment (OEHHA)’s that could affect the development of RfC and URE values. The commenter also stated that the EPA should consider and apply

its 2008 handbook on child

- specific exposure factors. The commenter expressed support for the EPA ’s implementation of the 2005 Supplemental Guidance for Assessing Susceptibility from Early

- Life Exposure to Carcinogens in the assessment of cancer risk from POM emissions, but contends that the EPA should follow the lead of OEHHA on the issue of age

- dependent adjustment factors for c arcinogens. The commenter noted that the 2005 Supplemental Guidance was generated in 2006 and must be updated to incorporate more recent evaluations of carcinogenic modes of acti on. The commenter further noted that the 2005 Supplemental Guidance does not account for increased cancer risk resulting from prenatal exposure. The commenter stated that the EPA ’s lack of analy sis regarding increased earl y life susceptibility

to HAP emissions “sy stematicall y underestimates risk” from the following pollutants:
 Hexavalent Chromium
 Dioxins
 Arsenic66

 Cadmium
 POM The commenter stated that failing to account for early life vulnerability

and increased risks to children ad ds additional uncertainty to the risks from this source category . The commenter noted that the Food Quality Protection Act uses an uncertainty factor of ten to account for this ty

pe of increased uncertainty and recommended that the EPA , at a minimum, do the same.
**RESPONSE:** The commenter is mistaken both that the EPA applied the lead primary NAAQS unthinkingl y as a measure of acceptable risk, and further mistaken in its argument that the primary

lead NAAQS is an inappropriate measure of risk acceptability (for lead) here because (according to the commenter) it is not designed to, and does not protect sensitive populations living near secondary lead smelters. First, the lead NAAQS primary standard targets protection to the most susceptible group in the hum an population

– children

– and is designed to protect against adverse effects to children’s most sensitive organ s ys tem

– the developing neurological s ys tem. See 73 FR at 66975, 66976. 7 Second, the primary NAAQS for lead is specificall y targeted at those c hildren living near major sources of lead, such as secondary smelters. See 73 FR at 67002/3 (“in applying the evidence

- based framework, we are focused on a subpopulation of U.S. children, those living near air sources and more likely to be exposed at the l evel of the standard”); to the same effect see 73 FR 67000/3

-- (“The framework in effect focuses on the sensitive subpopulation that is the group of children living near sources and more likely to be exposed at the level of the standard. The evidence

- based framework estimates a mean air

- related IQ loss for this subpopulation of children; it does not estimate a mean for all U.S. children”;). 73 FR 67005/1

-- (“the air

- related IQ loss framework provides estimates for the mean air

- related IQ loss of a subset of the population of U.S. children, and there are uncertainties associated with those estimates. It provides estimates for that subset of children likely to be exposed to the level of the

7 “While adults are susceptible to Pb effects at lower blood Pb levels than previously understood... , the greater influence of past exposures on their current blood Pb levels... leads us to give greater prominence to children as the sensitive subpopulation in this review . Children are at increased risk of Pb

- related health effects due to various factors th at enhance their exposures (e.g., via the hand

- to - mo uth activity that is prevalent in very young children...) and susceptibility.” 73 FR at 66975. With regard to neurological effects, the EPA stated “[a]mong the wide variety of health endpoints associated wi th Pb exposures, there is general consensus that the developing nervous system in children is among the, if not the, most sensitive.” 73 FR at 66976.67

standard, which is generally expected to be the subpopulation of childre n living near sources who are likel y to be most highl y exposed.”) 8 Inaddition, in reviewing and sustaining the lead primary NAAQS, we note that the D.C. Circuit specificall y noted that the rule was targeted to protect children living near lead sources: “EPA explained that the scientific evidence showing the impact of lead exposure in young children in the United States led it ‘to give greater prominence to children as the sensitive subpopulation in this review’ and to focus its revision of the lead NAA QS on the ‘sensitive subpopulation that is the group of children living near [lead emission] sources and more likely to be exposed at the level of the standard.’ Given the scientific evidence on which it relied, EPA’s decision to base the revised lead NAA QS on protecting the subset of children likel y to be exposed to airborne lead at the level of the standard was not arbitrary or capricious.” Coalition of Battery Recyclers , 604 F. 3d at 618. The commenter further maintains that the primary lead NAAQS i s an inappropriate measure of acceptability

of risk “because it ignores the cumulative, long

- term impacts to individuals in the local affected communities from prior lead emissions”. EPA has not ignored such exposures. First, as part of the Risk and Exposure Assessment supporting the lead primary NAAQS, the EPA assessed the IQ loss associated with the cumulative environmental impact of long

- term emissions in communities living near stationary sources of lead emissions, specifically lead smelters. See Lead Human Exposure and Health Risk Assessments for Selected Case Studies; Volume IHuman Exposure and Health Risk Assessments 00 Full Scale; and Volume II: Appendices ((USEPA, 2007) (Office of Air Quality Planning and Standards, Research Triangle Park, NC EPA
- 432/R

- 07
- 014a and EPA

- 452/R

- 07
- 014b; see also 73 FR 66979

- 66983. The Risk and Exposure Assessment assessed exposure to lead from the inhalation route as well as the multiple ingestion pathway s. Although the EPA relied primaril y upon the evidence

- base d 8 EPA further found that “ The current evidence... with regard to the quantitative relationship between neurocognitive decrement, such as IQ, and blood Pb levels indicates that the slope for Pb effects on IQ is non

- linear and is steeper at lower blood Pb levels, such that each [mu]g/dL increase in blood Pb may have a greater effect on IQ at lower blood Pb level s... than at higher levels.” 73 FR at 66976

- 77; to the same effect, see 73 FR at 67002, 67004. Consequently, as EPA stated in responses to comment in the lead NAAQS rulemaking, i n the case of the child who experiences significant exposure to lead due to non

- air sources in addition to ambient air

- related lead exposure (producing a relatively larger total lead exposure), the IQ loss for each increment of air

- related lead exposure will likely be less than it is for a child with lower total lead exposure. (See E PA
- HQ
- OAR
- 2006
- 0735
- 5894 at page 13).68

framework (i.e. epidemiological studies and related information) in developing the lead primary NAAQS, the EPA nonetheless found the air

- related lead risk estimates from the Risk and Exposure Assessment to be generally supportive of that scientific evide nce - based framework
. (See 73 FR at 67003

- 04.) The evidence

- based framework used in developing the lead NAAQS is focused on children with total lead exposure closer to the current U.S. average (than the more highly lead exposed upper percentiles of the po pulation), since these children will have greater response to each increment of air

- related lead exposure than would children with higher overall blood lead levels. 73 FR at 66976
- 77. Other populations, including children with higher blood lead levels due to past exposures, will necessaril y be accorded protection from air

- related lead as well. 9 (See EPA
- HQ
- OAR
- 2006
- 0735
- 5894 at page 13). The commenter nonetheless noted that in setting the NAAQS, the EPA recognized that there would be greater impacts to the more exposed individuals. The commenter contends that children living near secondary lead smelters are not only a population with increased susceptibility , but they

also face elevated levels of exposure because they live near secondary lead smelters. The commenter states that EPA’s staff paper for the lead NAAQS shows that children living near the lead smelting facilities would still be subject to an IQ loss as high as 3.9 (at the median) to 7.3 (at the 95 th percentile), even if the EPA had set the NAAQS at 0.02 instead of 0.15 μg/m 3 . The commenter stated that this shows that an ambient air concentration of 0.02 μg/m 3 would not achieve an acceptable level of risk for children living near a secondary lead smelter, let alone provide an ample margin of safety. The commenter stated that the EPA must set a residual risk standard that prevents the local ambient lead concentration from exceeding the CHPAC
- recommended limit of 0.02 μg/m 3 as a monthly average. The commenter contends that in choosing the lead NAAQS, the EPA “chose to allow an IQ point loss for the children...living near lead smelting facilities, above the 1 to 2 points that is considered to be “highly

significant from a public health perspective,” and above the 2 points that is considered to allow an “adequate margin of safety” for the national population level of exposed children.” Therefore, the commenter contends, “ replicating the NAAQS ” in this rulemaking fails the section 112(f)(2) test to provide an ample margin of safety to communities near secondary

lead smelters.

9 I n responding to these comments, EPA is not reconsidering, reopening, or otherwise reassessing any aspect of the lead NAAQS (either primary or secondary).6 9

The EPA disagrees. In establishing the 2008 Pb NAAQS, EPA recognized that more highl y exposed individuals were at risk of greater adverse effects from lead, and EPA promulgated a revised Pb NAAQS that would provide the requisite degree of protection, with an adequate margin of safety , for the health of these individuals, speci fically targeting protection at children living near sources of lead emissions exposed at the level of the standard , as demonstrated above
. EPA did not find that this standard would result in still greater IQ loss for children living near lead sources. As shown above, these are precisel y the susceptible subpopulation at which the standard is targeted. EPA’s determination that this susceptible subpopulation would be exposed to an air

- related IQ loss of no more than 2 points was supported by the evidence

- based framework (i.e. epidemiological studies and related materials) that was the primary basis for EPA’s de cision. See 73 FR at 6700 6, where the Agency explained The Administrator notes that the evidence

- based framework indicates that for standard levels above 0.15 ųg/m3, the estimated mean air

- related IQ loss in the subpopulation of children exposed at the l evel of the standard would range in almost all cases from above 2 points to 5 points or more with the range of air

- to blood ratios considered. He concludes, in light of his consideration of all of the evidence, including the framework discussed above, that the protection from air

related Pb effects at the higher blood Pb levels that would be allowed b y standards above 0.15 ųg/m3 would not be suffic ient to protect public health with an adequate margin of safety
. In addition, the Administrator notes that for standard levels below 0.15 ųg/m3, the estimated mean IQ loss from air

- related Pb in the subpopulation of children exposed at the level of the st andard would generally be somewhat to well below 2 IQ points regardless of which air

- to - blood ratio within the range of ratios considered was used. The Administrator concludes in light of all of the evidence, including the evidence

- based framework, that the degree of public health protection that standards below 0.15 ųg/m3 would likely afford would be greater than what is necessary to protect public health with an adequate margin of safety
. T he commenter appears to basing its assertions on portions of E PA’s quantitative assessment report prepared for the primary Pb NAAQS prepared as part of the NAAQS review process. EPA

–452/R

– 07

– 014a and EPA

–452/R

– 07

– 014b
. 10 The commenter goes too far. Although the results of the risk assessment were generall y supporti ve of the evidence

- based air

related IQ estimates, EPA did not rely on those estimates in establishing the level of the standard.
10 The commenter refers to the EPA Staff Paper for its stat ement. However, EPA has not been able to find or duplicate the quantified numbers appearing in their comment. The Staff Paper and notice of final rulemaking (p. 66982) indicates a median air

- related IQ loss estimated to be less than 3.7 (using the higher confidence loglinear C

R function, and less than (1.2

- 5.1) via the other 2 functions) for children living within 1.5 km of primary smelter s under simulated conditions associated with a NAAQS level of 0.2 ug/m3, a level slightly highe r than the current NAAQS of 0.15 ug/m3
.70

See 73 FR at 67006. T he lead NAAQS was based primarily on the scientific evidence and to a lesser extent the results of th e risk and exposure assessment

-- that is, on the epidemiologic information rather than on the exposure and risk assessment due to that assessment’s associated limitations and uncertainties (see 73 FR from 6 6 979 to 66982). 11 Thus, EPA disagrees that the curre nt or previous risk assessment report s or Staff Papers provides a basis for concluding that the current NAAQS is inadequate to protect the health of children living near sources of lead emissions
. Furthermore, we disagree with the general comment that EPA does not consider the groups that may

be most at

- risk in its risk assessments (e.g, pregnant woman). By providing protection to the most susceptible parts of the population

– here, children living near lead sources exposed at the level of the standard

– the standard necessarily provides protection to less susceptible populations. 73 FR at 67005/1. Thus, the lead NAAQS was based on the prevention of adverse health effects of children based on prev enting effects to the developing nervous sy stem in children living near lead sources and exposed at the level of the standard . Similarly , when EPA derives exposure reference concentrations and unit risk estimates for non

- lead HAP, it also considers the mos t sensitive populations identified in the available literature, and importantly , these are the values used in our risk assessments (see US EPA. (2002) , . A R eview of the R eference D ose and R eference C oncentration P rocesses. EPA/630/P

- 02/002F. Risk Assess ment Forum, Washington DC. Available online at http://www.epa.gov/raf/publications/pdfs/rfd

- final.pdf )
. Finall y, with respect to maternal exposure in utero specifically , we are unaware of literature that would allow for a robust characterization of ris k during this stage of development
. We further note that i n developing the NAAQS for lead, because of the multi

- pathway , multi

- media impacts of lead, the risk assessment supporting the NAAQS considered direct inhalation exposures and indirect air

- related multi

- pathway exposures from industrial sources like primary

and secondary

lead smelting operations. More specifically , EPA assessed the IQ loss associated with the cumulative environmental impact of long

- term emissions in communities living near stationary sources of Pb emissions, specifically Pb smelters. (USEP A, 2007; 73 FR 66979
- 66983 , also see the L ead NAAQS Human Exposure and Health Risk Assessment available at http://epa.gov/ttn/naaqs/standards/pb/s_pb_cr_td.html )
. As noted, these
11 Courts have repeatedly upheld EPA’s decisions to base the NAAQS on evidence

- based, rather than risk

- based information given the uncertainties involved in risk and exposure assessments. See American Trucking Ass’n v. EPA , 283 F. 3d at 371; American Farm Bureau v. EPA , 559 F. 3d at 527.71

risk estimates were judged to be generally supportive of the scientific evidence that was the primary basis for revising the lead NAAQS (73 FR at 67004). Taken together, the EPA believes that the lead primary NAAQS is a reasonable benchmark to use i n evaluating the potential for multipathway

health effects from lead compounds
. Furthermore , as noted in the risk assessment document for today ’s rule , there is no RfD or other comparable chronic health benchmark value for lead compounds. That is, in 198 8, the EPA’s IRI S program reviewed the health effects data regarding lead and its inorganic compounds and determined that it would be inappropriate to develop an RfD for these compounds, saying, “A great deal of information on the health effects of lead ha s been obtained through decades of medical observation and scientific research. This information has been assessed in the development of air and water quality criteria b y the agency's Office of Health and Environmental Assessment (OHEA) in support of regul atory decision

- making by

the Office of Air Quality

Planning and Standards (OAQPS) and by the Office of Drinking Water (ODW). By comparison to most other environmental toxicants, the degree of uncertainty about the health effects of lead is quite low. It ap pears that some of these effects, particularly changes in the levels of certain blood enzy mes and in aspects of children's neurobehavioral development, may occur at blood lead levels so low as to be essentially without a threshold. The agency's RfD Work Group discussed inorganic lead (and lead compounds) at two meetings (07/08/1985 and 07/22/1985) and considered it inappropriate to develop an RfD for inorganic lead.” The EPA’s IR IS assessment for Lead and compounds (inorganic) (CASRN 7439

- 92
- 1), http://www.epa.gov/iris/subst/0277.htm
. In short, this rule does not “replicat[e] the lead NAAQS as an ambient standard” as the commenter would have it. EPA is using the lead primary NAAQS as a measure of deter mining whether risks posed b y emissions of lead from this source category , after implementation of the section 112 (d) MACT standard, are acceptable. That is the first step of the process of determining what standards are protective of public health with an ample margin of safety under the methodology

set forth in the Benzene NESHAP and its codification in section 112 (f)(2)(B). In arriving at the standards adopted in this rule, we have necessarily conducted the second step of the process, the ample marg in of safety anal ys is, considering such issues as technical feasibility and cost as well as the range of risk information relevant in the determination. We have evaluated risks posed b y the emissions from this source category , found the risks to be unacc eptable, and required further controls as a result. We view these controls as reducing risk72

to an acceptable level to all groups with an ample margin of safety , considering not onl y risk but technical feasibility , cost, and cost effectiveness, as well as other factors relevant under the benzene NESHAP decision framework. Our determination considers risk on a total facility basis. We have explained that further controls on stack emissions are not justified based especiall y on considerations of cost and co st - effectiveness. This conclusion is the same no matter how much cumulative exposure from previous emissions is considered
. . ( In this regard, we note that the commenter’s assertions regarding past multi

- media contamination, and potential for lead exposu

re from these sources other than ambient air, are unquantified and somewhat speculative.). To the extent the commenter is arguing that this rule should be used to remediate past soil deposits **(“** EPA may

not set a residual risk standard that primaril y addresses ambient air ”), the comment goes too far. Such remediation activities are conducted under other authorities, notably RCRA and CERCLA. With respect to the comment concerning HAP emissions other than lead , the EPA disagrees with the commenter’s as sertion that the chronic noncancer health benchmarks used for the assessment are not protective of children. The EPA uses RfC values and chronic REL values that are expressl y derived with the intention of protecting sensitive subpopulations , including chi ldren (see U. S
. EPA. (2002). A review of the reference dose and reference concentration processes. EPA/630/P

- 02/002F. Risk Assessment Forum, Washington DC. Available online at http://www.epa.gov/raf/publications/pdfs/rfd

- final.pdf. With respect to cancer, the EPA uses the age - dependent adjustment factor approach referred to by the commenter, but limits the use of those factors onl y to carcinogenic pollutants that are known to act via mutagenic mode of action, in contrast to the OEH HA approach which uses them across the board for all carcinogens regardless of mode of action. The EPA believes the OEHHA approach is unwarranted and overly conservative, and provides its lengthy rationale for this approach in the 2005 Supplemental Guidan ce , as referred to by the commenter. With respect to the commenter ’ s recommendation for EPA to use the California benchmark s developed explicitly for protecting children, we note that the EPA is currentl y evaluating whether or not it is appropriate to use the CalEPA child

- specific reference doses , and further n otes that there are currently no such values for HAP inhalation, so their current utility would be limited to PB

- HAP which may be associated with non

- negligible ingestion exposures . That is, before using these child

- specific reference73

doses, the EPA wants to evaluate whether they have been appropriately

derived 12 . In addition, the EPA has a hierarch y of appropriate health benchmark values and in general, this hierarch y places greater weight on the EPA derived health benchmarks than those from other agencies (see http://www.epa.gov/ttn/atw/nata1999/99pdfs/healtheffectsinfo.pdf ). Notably , this hierarchy favoring EPA benchmar

ks (when they

exist) over all others has been endorsed by the SAB. The commenter also makes the legal argument that the primary NAAQS provides an “adequate” margin of safety , but that section 112 (f)(2) requires that a residual risk standard provide an “ample” margin of safety, reasoning from this that a NAAQS cannot just be substituted as the measure for evaluating acceptability of risk and that some greater level of protection is required. We do not accept the commenter’s argument
. EPA is considering th e primary NAAQS for lead

-- which incorporates an adequate margin of safety

-- in determining which lead risks from air

- borne lead from secondary lead smelters are acceptable or unacceptable. Thus, to the extent the commenter’s argument rests on the difference between ‘adequate’ and ‘ample’ margin of safety , the argument is misplaced 13 Margin

- of

- safety determinations for this rule are conducted separately , in accord with the two

- step framework set forth in the Benzene NESHAP and the en banc opinion in Vinyl Chloride. See not only Vinyl Chloride , 824 F. 2d at 1165, 1166 but NRDC v. EPA , 902 F. 2d 962, 973

- 74 (D.C. Cir. 199 0 ) (distinguishing the NAAQS process, whereb y the margin of safety anal y sis is incorporated as part of the standard without a two

- step anal ys is, from residual risk determinations)
. 14

. Using that framework, with its consideration of costs, cost

- effectiveness, technological feasibility , and other factors set out in the Benzen e NESHAP, we did not identify an y additional controls beyond those that would need to be implemented to ensure an acceptable level of risk with an ample margin of safety
. EPA thus disagrees with the commenter that section 112 (f)(2) standards must be more stringent than a primary NAAQS as a matter of law
. **Comment :**  Commenter 98 stated that the list of contaminants identified in the 2003 Risk Assessment Guidance as being b oth persistent and bio

- accumulative (‘PB’) in the environment is inaccurate and ignores HAPs which present a mu ltipathway risk. The commenter note d , for example, that arsenic is a metal and is persistent in the environment. Therefore, assessing 12 The California acute value for arsenic, which has been considered by EPA and is discussed above at page 67 is not child

- specific. 13 Indeed, EPA’s utilization of a standard which al so incorporates an adequate margin of safety to evaluate acceptability of risk is an added conservative (i.e. protective) element in its approach here. 14 The court was referring to the predecessor provision to the current section 112 (f), but its analysi s is equally applicable to the revised provision.74

arsenic risk solel y from inhalation underestimates risks associated with ingestion of arsenic

contaminated soil and fish. The commenter also stated that excluding lead from the multipathway

risk assessment is not justifiable as lead is persistent in the environment and also bio

- accumulates in biota
. The commenter further noted that restricting the multipathway risk assessment to only contaminants that bioaccumulate is not supported by the 2003 guidance. The commenter contends that the 2003 Guidance does not dire ct that the multipathway risk assessment be limited to PB
- HAPs. The commenter further stated that excluding contaminants that persist in soils underestimates risks from HAPs emitted from secondary lead smelters and it is therefore insufficient to rel y on the lead NAAQS standard as a benchmark for multipathway risk due to lead . The commenter stated that “Onl y a forward calculation of the estimated cumulative and multipathway

risk from the lead and other HAP emissions satisfies the requirements for the res idual risk assessment.” The EPA may not simply

assume that the lead NAAQS satisfies section 112(f)(2), but must actually perform the residual risk analy sis required to set standards under section 112(f)(2), avoid unacceptable risk, and provide an ample margin of safety for public health. The commenter note d that the lead NAAQS separated lead exposure into “recent” and “past” air and “did not include both categories equally in setting of the standard.” **Response** : In the Air Toxics Assessment L ibrary (see http://www.epa.gov/ttn/fera/risk_atra_main.html ), we developed the current persistent and bioaccumulative HAP (PB

- HAP) list considering all of the available inform ation on persistence and bioaccumulation. This list was peer

- reviewed by the SAB, and it is reasonable to use it in the RTR program. B ased on the limited available information on the persistence and bioaccumulation of arsenic, we do not believe that the potential for multipathway risk rises to the level of the PB

- HAP currently on the list
. We disagree with the commenter that a separate multipathway risk assessment should have been performed for lead. As noted in previous responses, the NAAQS for lead was used as a health based standard in this r eview but was not simply adopted mechanically , but rather is justified under the independent decision framework in section 112 (f)(2). We note that the NAAQS for lead was set to protect, with an adequate margin of safety, the health of the most susceptibl e children and other potentially at - risk populations against an array of adverse health effects, most notably

including neurological effects, particularl y neurobehavioral and75

neurocognitive effects (which are the most effects to which children are most sen sitive) (73 FR at 67007). We further note that in developing the NAAQS for lead, air

- related multipathway effects were already taken into account . That is, as noted at 73 FR at 6 6971:

“ As was true in the setting of the current standard, multimedia distrib ution of and multipathway

exposure to Pb that has been emitted into the ambient air play a key role in the Agency ’s consideration of the Pb NAAQS. ” In addition, the commenter is correct that a distinction was made between “recent” and “past” air in the exposure and risk assessment to support the lead NAAQS review (73 FR 66980). Howe ver, as explained in earlier responses of this document , EPA based the lead primary NAAQS primarily on the scientific evidence and to a lesser extent the results of the risk assessment
. Thus, the distinction between “recent” and “past” air in the risk and exposure assessments had little effect on the final decisions reached in the lead NAAQS. **Comment :**  Commenter 98 stated that the EPA failed to include an exposure scenario that assesses cumulative risk from HAPs in the urban environment and therefore potentially significantl y underestimates risks from this sourc e category . The commenter noted that soil contaminants are of particular concern to children due to particular beha viors that increase their exposures via incidental ingestion. The commenter contends that the EPA ’s failure to assess an urban child scenario as part of the cumulative risk assessment “ignores the exposure that may pose the most significant risk from this source category .” The commenter further noted that the EPA’s multipathway risk assessment relies on incidental soil ingestion exposures taken from the EPA ’s 1997 Exposure Factors Handbook. The commenter stated that these values are outdated and that the EPA should use more recent studies and estimates found in the 2009 update to th e handbook. The commenter noted that the EPA also has a 2008 child

- specific exposure factor handbook that it failed to consider. The commenter also stated that risks from expo sure to soil contaminants should evaluate both direct and indirect exposure. **Response :**  The criteria for selecting the facilities in the multipathway case study anal ys es are des cribed in sections 2.4 and 2.5 of the Human Health Multipathway Residual Risk Assessment for the Secondary L ead Smelting Source Category (available in the docket for this rulemaking). As noted in that draft document, the EPA believes that these locations are in the upper end of the pot ential for multipathway risks from this source category (see page 1 of the multipathway

assessment available in the docket for this rule ) . Thus, even though neither of76

these scenarios are in an urban environment, we believe that they were reasonable locations to conduct a multipathway assessment, especially considering that proximity to farm land and/or fishable lakes is a major co nsideration for a multipathway risk assessment . With respect to our inhalation risk assessment, this assessment was conducted to evaluate exposures occurring within 50 km of each facility in the source category. See 76 FR at 29039. Thus, any facilities located in urban areas would have been included in the inhalation risk assessment. The commenter’s assertion that EPA should h ave used estimates for children’s soil ingestion from the updated (2009) Exposure Factors Handbook, instead of the 1997 Exposure Factors Handbook (‘EFH’) , is not well taken. At the time of the multipathway assessment, the 2009 revision was a draft that ha d been released for public comment
. Thus, it was premature to adopt conclusions from this ty pe of draft document. We now note that this document has recentl y been finalized, but that its use would not have yi elded any change in the soil ingestion rates th at were used in the anal ys is to support the proposed rule (as detailed below). For adults, the recommended central tendency (i.e., mean) soil ingestion rate is 50 mg/day for both the 1997 EFH and the 2009 draft EFH; and this rate was used in the anal ys is underlying this rule . The 1997 EFH did not provide an upper percentile soil ingestion rate for adults ; therefore, as noted in Table C

- 3 of Appendix C of the background document (Human Health Multipathway

Residual Risk Assessment for the Secondary L ead Smel ting Source Category), the EPA used an upper percentile value from Stanek et al. 1997 . The draft 2009 EFH only provides an upper percentile ingestion rate for adults that is reflective of geophagy (i.e. dirt

eating) behavior, which we believe would result in overly conservative risk results and, as such, is not appropriate for this ty pe of risk assessment. As provided in Table C

- 3 of Appendix C of the background document Human Health Multipathway

Residual Risk Assessment for the Secondary L ead Smelting Source Category , the Child

- Specific EFH (CSEFH) was used by the EPA , where applicable, for child soil ingestion rates. The CSEFH

- recommended central

- tendency ingestion rate of 50 mg/day was used in the anal ys is (note that this value is one

- half the mean 100 m g/day ingestion rate recommended for children in the 1997 EFH). However, for the upper percentile ingestion rate, the 1997 EFH recommended ingestion rate of 400 mg/day was used for young children (those less than 6 years old) because the 2008 CSEFH onl y provides upper percentile ingestion rates that are reflective of pica and geophagy

behaviors, which, as noted above, we believe would result in overly77

conservative risk estimates. For older children (6 years of age and older) we assume the same soil ingestio n rate as for that of the adult. With regards to incidental soil contamination, the EPA has estimated risks from both direct and indirect pathway s. Direct routes of exposure include direct ingestion of soil and exposure through dermal contact. However, bec ause it has been demonstrated in past anal ys es that exposure levels associated with dermal contact are but a small fraction of exposure levels associated with ingestion and inhalation pathway s, dermal exposures were not assessed for secondary lead smelters . Indirect soil

- exposure pathway s are assessed through anal ys is of the consumption of produce and animal products that are grown or raised in contaminated soils. **Comment :**  Commenter 98 stated that the EPA ’s overall risk assessment is incomplete because it fails to add the inhalation and multipathway risk assessments in order to come up with a total risk that the EPA and the public can anal yz e. The commenter contends that the EPA should use this total risk to determine whether or not the risks from secondary lead smelters are acceptable and what standards would be needed to provide an ample margin of safety. **Response :**  The EPA disagrees with the commenter. Even though it is highly unlikel y that the same per son would have the highest inhalation and multipathway risk (the premise behind adding the two types of risk) , the EPA did include in its risk assessment document , a combined inhalation and multipathway MIR for the Exide Frisco facility (see section 3.2 of the draft risk assessment document, available in the docket for this rulemaking). We note that of the two multipathway

case studies, this facility was estimated to have the highest multipathway cancer risk, and the EPA therefore used it as the multipathw ay MIR facility

fo r the source category . However, we ( a s noted in several responses above), based on updated emissions information (i.e., emissions information received during the public comment period for the proposed rule which showed that emissions wer e lower than the EPA estimated at proposal ), multipathway risk associated with the Exide Frisco facility are estimated to be well below 1

- in a million. See section IV.A of the final rule preamble , section 3.2 of the final risk assessment document, and othe r comment responses for discussion of the updated Exide Frisco dioxin data. **Comment :**  Commenter 98 stated that the EPA underestimated the total risk that maximum exposed people are likel y to face and also fail ed to account for the increased risk caused b y a person’s exposure to multiple HAPs by not performing a full cumulative ris k anal ys is. The commenter noted that the EPA’s stated reasons for not addressing cumulative risk are “uncertainties.” The commenter stated that, where public health is concerned, uncertainty is78

not “a rational explanation”. The commenter contends that the EPA should follow SAB recommendations that the EPA conduct a sensitivity anal ys is to identify

major uncertainties in the risk assessments, explain these risks clearly in the risk characterization section, and take steps to reduce them. The commenter further stated that if the EPA chooses not to calculate cumulative risk, then it should, “at minimum, use the fact that it knows there is a greater risk than it has calculated as a reason to find a lower cancer, chronic non

- cancer, and acute threshold to be ac ceptable.” The commenter argued that the EPA has failed to gather the information needed to determine whether stronger standards are needed for this source category
. **Response :**  We disagree with the commenter’s statement that our risk assessments do not consider cumulative risk. We note that our a ssessment of cancer risks is, in fact, cumulative, summing the risks associated with all carcinogens emitted by a facility (see risk assessment document, section 3.2) . Similarly , the use of the target organ specific hazard index (TOSHI) for chronic non

- can cer effects evaluates the cumulative effects of HAP on a given target organ. Further, our assessment is cumulative in that it considers all emission points within the fence line (since they

are all covered by

the MACT). Moreover, the lead NAAQS is a cumulative standard in that it considered all air

- related exposures in its derivation as explained in comment response at pages 68
- 74. Moreover, to provide the quantitative risk information necessary to inform RTR regulatory

decisions, the EPA conducts a compre hensive assessment of the risks associated with exposure to the HAPs emitted by the source category

(i.e., those emissions that can actually be affected b y the specific rulemaking) and supplements that with additional available information about other poss ibl e concurrent and relevant risks . In some cases, we have additional information about HAP emissions that are outside the scope of the particular rulemaking but within the boundaries of the subject facilities. In other cases, we may have ambient HAP monit oring data that can be considered as part of the regulatory decision

- making. In still other cases, we may have very little additional risk information that can be considered. In all cases, however, when we consider additional information about risks, we al so consider its attendant uncertainties, and information which carries significant uncertainties generall y carries much less weight in the overall regulatory

decision. All of the quantitative risk assessment information about HAP emissions from the source category under consideration is also considered in the manner prescribed by the decision79

framework set forth b y the CAA for residual risk decision

- making (i.e., the Benzene NESHAP decision framework), and this means that the general guidelines of risk acceptability have been developed in a way

that they already take into account the impossibility of accuratel y quantifying the health risks posed b y outside forces on every individual in the population. This acknowledgment allows the EPA to make risk

- based dec isions by focusing on the risks associated with the emissions that are themselves the subject of regulation being considered. **Comment :**  Commenter 98 stated that, with regards to lead emissions, the EPA violated section 112(f)(2) b y stopping once it determined the level of emissions reductions needed to avoid exceedances of the lead NAAQS. The commenter contends that the EPA did not perform an anal ys is to decide whether reducing emissions to a level that would comply with the NAAQS would also reduce risk to an accept able level. The commenter noted that “what is acceptable at the population level is not necessaril y acceptable at the community level.” The commenter stated that rather than setting a standard that would reduce emissions enough to compl y with the NAAQS, the EPA must set a standard to reduce risks to an acceptable level. The commenter also noted that the EPA may not consider cost in determining the reduction in emissions needed to reduce risk to an acceptable level. **Response :**  The EPA disagrees with the commenter

– the NAAQS for lead did consider lead risks for children living around these types of facilities

– i.e. considerations of risk at the community

level . As explained in the preambl e for the lead NAAQS at 73 FR 67002/3: “More specificall y, in applying the evidence

- based framework, we are focused on a subpopulation of U.S. children, those living near air sources and more likely to be exposed at the level of the standard. While the ai r related Pb in the blood of this subpopulation is expected to be greater than that for the general population given their greater air

- related Pb exposure, we do not have information on the mean total blood Pb level (or, more specificall y, the nonair compo nent) for this subpopulation. However, even if we were to assume, as an extreme h ypothetical example, that the mean for the general population of U.S. children included zero contribution from air

- related sources, and added that to our estimate of airrelate d Pb for this subpopulation, the result would still be below the lowest mean blood Pb level among the set of quantitative C

–R analy ses See also comment response at pages 68
- 74 above, for further discussion of this issue. Moreover, a s noted in the preamble to the proposed rule, the lead NAAQS, a health based standard set to protect public health with an adequate margin of safety (including the health of80

sensitive populations), was chosen as a health benchmark to ensure that risks associated with lead exp osure were acceptable. See 76 FR at 29041
- 29042
. In using this benchmark to determine the highest level of emissions that could be associated with an acceptable level of air

borne risks to lead

- bearing emissions from secondary lead smelters, EPA chose to ensure that the worst - case impact created by an y source in the category was acceptable to the most sensitive individual in the entire population (which is, in this case, children living near the smelter and exposed to the level of the lead primary NAAQS ), regardless of whether or not the most sensitive individual in the population (i.e., a child) was deemed to reside at that point of worst

case impact. By

protecting against the most susceptible subpopulation, other exposed but less susceptible populations will necessaril y also receive protection, and not be exposed to unacceptable levels of lead. The EPA then considered in its ample margin of safety discussion whether additional cost effective , technicall y feasible controls were available to reduce risk further. However, the EPA did not find any additional controls that were justified under the second step of the residual risk anal ys is
. **Comment :**  Commenter 98 generall y commented that the EPA needs to up date it s framework for determining “acceptability” o f risks under the RTRs to reflect more current science and societal mores as to what risks are considered to be acceptable. The commenter notes that the science has evolved significantl y since the late 1980’s and they question wh y “100 in

- a - million” cance r risk level is still appropriate in light of current science and evolving community

standards (this later point based on language in the en banc Vinyl Chloride opinion)
. The commenter stated that for non

- lead emissions; the EPA presumes that the lifetime cancer risk here is “acceptable” because it is lower than 100

- in

- 1 million. The EPA does not address or explain why

an y risk below that level remains acceptable today. It is arbitrary and capricious for the EPA to continue to rely on that presumption as a basis for its decision for several reasons: 1. The Clean Air Act requires an up

- to - date, contemporary assessment and relying on an out - dated presumption conflicts with the very purpose of the residual risk analy sis. 2. There is significant new information on the factors the EPA discussed in its old rulemaking that should influence its analy sis today of what level of risk is currentl y “acceptable”. 3. Scientific research has evolved dramaticall y since the EPA set that presumption. There has been a vast increas e in understanding of the relationship between the environment and public health, in particular, appreciation for the importance of assessing environmental hazards and exposures with respect to community health and as they

are experienced b y individuals wh o live in communities. Commenter cites risk assessment studies and guidance, studies on children’s exposure to toxics, and CDC reports as81

providing evidence of the EPA and other federal funded research and developments in health effects of chemicals. 4. Th e EPA’s commitment to environmental justice must inform its consideration of what level of risk is “acceptable” as required b y the 1994 Environmental Justice Executive Order and 2010 guidance to direct all federal agencies to take environmental justice int o consideration. The consideration of environmental justice should factor into the question of what level of risk is “acceptable” today
. 5. American values and policies have evolved to tolerate less health risk from industrial pollution. As pollution

- control technology and industrial practices have evolved to be able to better protect human health, their evolution has also changed the “world in which we live” and with it, the public’s views on what level of risk may be acceptable (or not). The c ommenter contends that a lifetime cancer risk below the level of 100

- in

- 1 million can no longer be presumed “safe” or “acceptable” in “the world in which we live” due to the dramatic evolution of science, technology , and social values that have occurred in recent deca des. Due to these changed circumstances, the EPA must reassess whether a level below 100
- in 1 million and closer to the “aspirational goal” of 1

- in

- 1 million should be adopted as a more stringent, presumptive upper limit for what is considered “acceptable .” This is a question that the EPA cannot evade by assuming every

thing it did in the Benzene Rule will remain per se lawful for all time, all persons and communities, and all source categories. Ignoring the substantial new information and changed circumstances since the EPA last considere d that question is arbitrary

and capricious. Commenter 98 stated that the EPA fails to give a reasoned explanation for not proposing a stronger standard for arsenic and cadmium to provide an ample margin of safety. The commenter noted that the risk assess ment number the EPA found is five times the level associated with public health concerns and that the fact that cost are “high” for the WESP technology

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 emission reductions based on this technology . Commenter 95 also stated that emissions of arsenic and cadmium contribute to the risks posed by

secondary lead smelters, yet the EPA ’s proposal will not address these risks in a manner consistent with the CAA. According to the commenter, “When considering the risks associated with MACT

- allowable emissions, the MIR could be up to 200 in 1 million. EPA nevertheless has not proposed sufficientl y protective residual risk standards.” **Response** : As an initial matter, we note that in 1990 Congress codified in section 112(f) (2)(B) of the CAA the approach we use for our residual risk anal ys es. Under that approa ch, the82

100 in a million cancer risk is not a bright line indicating that risk is “acceptable
. ” Rather, we consider this health metric in conjunction with a variety of health factors to determine whether the risk is acceptable. Where we conclude that the risk is not acceptable, we cannot and do not consider costs in requiring controls to bring risks down to an acceptable level. However, the anal ys is of whether risk is acceptable is not the endpoint. Once we determine that controls are sufficient to ensure that risk is acceptable, we again review the health metrics in conjuncti on with the costs of controls , technical feasibility , and other relevant factors, to determine whether additional controls should be required to provide an ample margin of safety
. EPA also does not accept that the language in the en banc Vinyl Chloride o pinion regarding risks “acceptable in the world in which we live”, 824 F. 2d at 1165, dictates any particular quantitative result based on societal preference

– especiall y when the court, in using this language , was indicating that risk

- based standards for hazardous air pollutants did not need to be risk

- free. Moreover, the commenter does not support its contention that people are now unwilling to accept a level of risk that was acceptable at the time the CAA was amended in 1990. Nor does the commenter sup port how science has evolved in a way that would undermine the statutorily codified framework for determining risk acceptability . We note that for purposes of the proposed and final rule, we performed a demographic analy sis for the purpose of informing the public of what demographic groups could potentially be impacted b y a given rulemaking , and that anal ys is is in the docket. We also note that since risks from exposure to lead compounds are acceptable to the most susceptible subpopulation after controls under EPA’s approach here, other less susceptible populations likewise will be protected from unacceptable levels of risk from lead exposure as well. **Comment :**  Commenter 98 stated that the EPA must reduce risk to a TOSHI of 0.2 or below. According to the commenter: EPA has determined that this source category ’s HAP emissions result in a TOSHI or hazard quotient as high as 3 based on allowable emissions (or 0.6 based on “actual” emissions). In its discussion of whether the risk is “acceptable” and what reductions may

be required to reach such a level, EPA did not discuss the high TOSHIat all. EPA must address chronic non

- cancer health effects in its analy sis before finalizing this rule. In finding that a non

- cancer TOSHI of 1.0 or less is not a human health concern, EPA has ignored its staff’s scientific assessment and reversed its hazard index policy to align it with industry

wishes. In an internal memo from 2002, Residual Risk Program: Selection of Hazard Index L imits, EPA stated that the default HI83

limit for chronic non

- cancer risks should be well under 1.0 for individual sources
— specificall y, it should be 0.2. The rationale for a maximum non

- cancer HIof 0.2 expressed in the 2002 EPA memo states that a limit of 0.2 would allow an individual source to account for 20 percent of the contribution to total exposure in its vicinity . An HI limit of 0.2 attempts to provide a de minimis fraction below which contributions are considered insignificant to total exposure while not allowing a single source to d ominate the total exposures to similar noncarcinogens in its vicinity
. EPA has not evaluated other nearb y sources of HAPs, it has not considered the multipathway

exposure from certain pollutants, and it has failed to consider the interaction of multiple h ealth risks found for affected communities. Therefore, EPA’s anal ys is provides only one piece of the chronic non

- cancer health risk. Failing to ensure that chronic non

- cancer health risks do not exceed a TOSHI of 0.2 from this source category does not su fficiently

protect local communities’ health f rom cumulative exposure. EPA must address and account for cumulative impacts and multiple contributors to risk. It may not permit a single source covered b y this rulemaking to consume the entire non

- cancer ri sk safet y factor. **Response** : The EPA disagrees with the commenter’s notion that any TOSHI value greater than 0.2 should be considered unacceptable. We note that pollutant

- specific reference concentrations (RfCs) are not absolute thresholds, but estimates o f chronic inhalation exposures at or below which health effects would not be expected to occur, including in sensitive subgroups. We further note that these RfCs are developed using a health

- protective approach (see uncertainty discussion in risk assessment document section 4.2) , that TOSHIvalues of 1 or less are (like RfC levels) generall y considered to carry no appreciable risk of adverse health effects and that there is generall y no need to compound this protection by suggesting that an y source category maximum TOSHIvalue would need to be at or below 0.2 before we would consider it to be acceptable. We further note that we generall y draw no bright lines of acceptability regarding cancer or noncancer risks from source category HAP emissions, and that it is always important to consider the specific uncertainties of the emissions and health effects information regarding the source category

in question when deciding exactly what level of cancer and noncancer risk should be considered acceptable. In addition, the source category

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

-- chronic and acute, cancer and noncancer , and multipathway , -- along with their uncertainties, when determining the acceptable level of source category risk. Experience with source category rulemakings in the past tells us that this means84

that drawing bright lines for such decision

- making is impossible. The Benzene NESHAP d ecision framework of 1989 acknowledged this; in today ’s world, such flexibility is even more imperative, because new information relevant to the question of risk acceptability is being developed all the time, and the accuracy and uncertainty

of each piece of information must be considered in a weight

- of

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

- of

- evidence approach that acknowledges both complexity and uncertaint y in the simplest and most transparent way possible. While this challenge is formidable , it is nonetheless the goal of the EPA’s RTR decision

- making, and it is the goal of the risk assessment to provide the information to sup port the decision

- making process. In this case, the pollutant primarily driving the unacceptable risk is lead compounds , and control of lead compounds to meet the primary lead NAAQS reduces lead risk of air

- borne lead emissions from this source category t o an acceptable level. See Section IV .A of the preamble
. With regard to lead as well as to other HAP, as part of the second step ample margin of safety anal ys is , we did look for additional controls and process improvements that might further reduce risks in a cost

- effective , technicall y feasible manner. In this case, we didn't find any additional cost - effective controls and ultimately concluded that the level of control that brought risks to an acceptable level was also the level of control that resulted in public health being protected with an ample margin of safety
. See 76 FR at 29057
- 59 . Moreover, control of lead will effectively co - control all other metal HAP, see Secondary Lead Smelting

-- Background Information for Promulgated Standards (EPA

- 453/R

- 95

- 008b) at page 2
- 19 , a conclusion unchallenged in the record for this rulemaking. Finally , we note that the commenter’s source for its statement that default limits HI should or must be established at 0.2 rest on an internal EPA staff memo (from 2002) wh ich was never adopted as agency

policy (and never reviewed by the public or by

any peer review body) and consequently

carries no precedential weight. **Comment :**  Commenter 98 stated that the EPA did not appropriatel y address issues of socioeconomic dispari ty

in health risks from this source category . While supporting the EPA ’s effort to gather demographic data and to incorporate environmental justice into their consideration of what level of public health risk is “acceptable” or not under section 112(f)(2 ) the commenter stated that the EPA should use these data to protect families from unacceptable85

risk. A level of risk that might otherwise be “acceptable” becomes unacceptable when, as here, lower income individuals are disproportionately affected. **Respon se**  **:** As explained in response at pages 64 above, there is higher incremental IQ loss at low blood lead levels and a standard that would protect against incremental IQ loss at low blood levels would also protect populations with higher blood lead levels
. Moreover, the lead primary NAAQS targets protection at the most susceptible subpopulation for the most sensitive effect: children living near a lead source with low blood lead levels who are exposed to air

- borne lead at the level of the NAAQS. By assuring that risks to this most susceptible subpopulation are reduced to acceptable levels, subpopulations who are less susceptible are also necessarily protected from unacceptable risk. As EPA explained in the lead NAAQS proceeding, “EPA agrees with commenter s that on average in the U.S., minority and low

income children have higher blood Pb levels than the general population, as shown by the NHANES information referenced in section II.A.2.b of the preamble and described in section II.B.1.a of the proposal (e. g., http://www.epa.gov/envirohealth/children/body_burdens/b1

- table.htm ). EPA also agrees that these higher average blood Pb levels are indicative of these subpopulations being sensitive with regard to total Pb exposures. However, EPA notes that this eviden ce does not provide information regarding a potential for increased sensitivity

to air

- related Pb exposure. Due to the nonlinear dose

response relationship between IQ loss and blood Pb, EPA concludes that the population with lower blood Pb levels from both air and nonair sources would be expected to have a greater incremental sensitivity to Pb impacts on I Q (i.e., greater risk of IQ loss per incremental unit of blood Pb). Thus, a standard that is selected to provide protection from the incremental amount of blood Pb a ssociated with air

- related Pb to populations with lower total blood Pb levels will also necessarily provide protection from the air

- related Pb associated with exposures at the level of the standard to populations with higher total blood Pb level s. As explained in section II.C.3.b of the preamble, the air

- related IQ loss framework focuses on children exposed at the level of the standard, children living near air sources of Pb who are likel y to be most highly exposed. In concentrating on this highl y exposed group of children, EPA has focused on providing sufficient protection for the appropriate subpopulation for this review.” Pb NAAQS, Response to Comment Document p. 7 , available at http://epa.gov/ttn/naaqs/standards/pb/s_pb_cr_rc.html
. To reiterate , since the revisions to this standard will protect the most sensitive subpopulations, it will also protect all other population subgroups and demographic groups.86

**Comment :**  Commenter 98 stated that the EPA has failed to justify not requiring the reduction of acute health risk below 1. According to the commenter: EPA recognizes that the worst

- case acute hazard quotient is 30. Nine existing facilities have a worst

- case hazard quotient above 1. EPA has recognized that a hazard quotient of 1 or above indicates the potential for acute risk. EPA”s proposal states that the controls it is proposing for arsenic emissions will reduce the acute HQ values to 5 or below. However, thi s is five times the hazard quotient that may be associated with acute health effects. EPA fails to address or explain why it is not requiring additional emissions reductions of arsenic to ensure that the acute risk is reduced to a level below 1. **Response :**  The commenter is correct that post

- control, there would be one facility with an estimated acute risk of 5 in the risk assessment supporting the proposed rule
. See Appendix 5 to the risk assessment for the proposed rule at page 4, docket ID EPA

- HQ
- OAR
- 2 011
- 0344
- 0036. This does not mean that the risk is unacceptable. We first note that th ere would be onl y two facilit ies in the source category with an estimated worst - case acute risk greater than 1 post control . In addition, the EPA notes that acute risk of 5 post

- control is based on a reference exposure level ( REL ) value, which is not a concentration at which health effects are expected to be observed. That is, the RELis defined as “ the concentration level at or below which no adverse health effects are anticipated for a specified exposure duration” (see section 2.6.2 of the draft risk assessment document in the docket for this rulemaking). Moreover, we note that the acute risk assessment is a worst case assessment. For example, the acute assessment a ssumes worst - case meteorology , peak emissions and an individual being located at the site of maximum concentration for an hour. Taken together, the EPA do es not believe that in all RTR reviews, HQ values must be less than or equal to 1. Rather, the EPA finds that acute risks must be judged on a case b y case basis in the context of all the available health evidence and risk anal ys es. Here, for the reasons just given, EPA considers the risk from acute exposure to be acceptable given the generall y low HI v alues ( that are based on worst case assumptions )
. **Comment :**  Commenter 98 stated that the EPA ’s proposal fails to provide an ample margin of safety

to protect public health from lead emissions. The commenter stated that the EPA ’s proposal has not met the l egal standard of section 112(f)(2) as it merely replicates the lead NAAQS. The commenter contends that the Clean Air Act sets different tests for the NAAQS and NESHAP rules and that the EPA cannot substitute one for the other.87

The commenter noted that the plain text of section 112(f)(2) uses the term “ample margin of safety”, while the lead NAAQS is a standard that allows an “adequate margin of safety.” Citing the definitions of the words “ample” and “adequate”, the commenter contends that using the term “ample” demonstrates that the EPA is required to do more than just set an “adequate” or bare minimum level of protection. The commenter further noted that the lead NAAQS “merel y aims to prevent a loss above 2 IQ points at the mean population level of expos ure, even though in EPA’s staff’s view, a loss below that, of 1

- 2 IQ points, could be considered ‘ highl y significant from a public health perspective. ’ ” The commenter also stated that section 112(f)(2) requires a different focus than section 109. More spe cifically , the NAAQS’s focus is protecting the national population as a group, whereas under section 112(f)(2), the EPA is required to protect the people living near the sources in the category
. The commenter noted that in setting the NAAQS, the EPA recognized that there would be greater impacts to the more exposed individuals. The commenter contends that children living near secondary

lead smelters are not onl y a population with increased susceptibility , but they also face elevated levels of exposure bec ause they live near secondary

lead smelters. The EPA’s staff paper for the lead NAAQS shows that children living near the lead smelting facilities would still be subject to an IQ loss as high as 3.9 (at the median) to 7.3 (at the 95 th percentile), even if the EPA had set the NAAQS at 0.02 instead of 0.15 μg/m 3 . The commenter stated that this shows that an ambient air concentration of 0.02 μg/m 3 would not achieve an acceptable level of risk for children living near a secondary lead smelter, let alone provid e an ample margin of safety. The commenter stated that the EPA must set a residual risk standard that prevents the local ambient lead concentration from exceeding the CHPAC

- recommended limit of 0.02 μg/m 3 as a monthly

average. The commenter contends that in choosing the lead NAAQS, the EPA “chose to allow an IQ point loss for the children...living near lead smelting facilities, above the 1 to 2 points that is considered to be “highly

significant from a public health perspective,” and above the 2 points that is considered to allow an “adequate margin of safety” for the national population level of exposed children.” Therefore, replicating the NAAQS in this rulemaking fails the section 112(f)(2) test to provide an ample margin of sa fety to communities near secondary lead smelters. The commenter further stated that replicating the lead NAAQS as a standard is also problematic because it ignores cumulative, long

- term impact to individuals from prior lead88

emissions. Ambient lead concentrations are not the only relevant thing because it does not account for reservoirs of lead in soil and elsewhere. The commenter contends that children can face higher levels of exposure from dust and soil than from inhaling air. The commenter claimed that “EPA say s the standard provides an ample margin of safety because EPA has not identified any further feasible and cost

- effective controls beyond the wet electrostatic precipitator which it deems too expensive.” The commenter stated that the EPA provides no explanation as to how the fact that it was unable to identify less expensive control options means the ample margin of safety requirement is met. The commenter further noted that the EPA , in its own analysis, identified other facilities that are using HEPA filters in addition to baghouses to achieve lower concentrations of lead. The commenter noted that the ample margin of safety determination is “a decision about whether to set the standard lower than the acceptable risk, taking feasibility into account.” The commenter further noted that most facilities achieve emission levels well below those proposed by the EPA and that the data demonstrates that the risks can be reduced further beyond the EPA ’s proposed standard, taking feasibility and cost into acc ount. **Response :**  Most of this comment is addressed at page 64 above. We add that i n order to assess multipathway

risks associated with emissions of lead, the EPA compared modeled rolling three month average lead concentrations estimated from emissions to th e NAAQS for lead. As noted above, we believe that this is a reasonable approach given that the NAAQS is a health based standard set to protect the public health, including the health of sensitive sub

- populations with an adequate margin of safety. Moreover, the NAAQS for lead specifically is targeted to provide requisite protection with an adequate margin of safety to prevent neurologic effects to children with low blood lead levels living near a lead source and exposed at the level of the NAAQS. While we c onclude that the NAAQS presents an acceptable level of risk from lead in ambient air, and are requiring controls to ensure that the NAAQS is not exceeded, as part of our “ample margin of safety” anal ys is, we examined whether there were additional cost effe ctive controls available to further protect public health including monitoring at a level below 0.15 μg/m 3 . For the reasons explained elsewhere in this notice and other supporting documents available in the docket, we have determined that there are no addi tional cost effective , technicall y feasible controls that would provide further risk reductions. In addition, the commenter states: “ EPA’s staff paper for the lead NAAQS shows that children living near the lead smelting facilities would still be subject to an IQ loss as high as 3.989

(at the median) to 7.3 (at the 95th percentile), even if the EPA had set the NAAQS at 0.02 instead of 0.15 μg/m3.” As noted above, this comment may be in error. The Staff Paper and notice of final rulemaking ( 73 FR at 66982) indicates a median air

- related IQ loss estimated to be less than 3.7 (using the higher confidence loglinear C

- R function, and less than (1.2

- 5.1) via the other 2 functions) for children living within 1.5 km of primary smelter s . Moreover, as noted in the earlier comment response, EPA did not rely on the risk assessment as the primary basis for its revisions to the primary

lead NAAQS
. With respect to the California benchmark for protecting children, the EPA has a hierarchy of app ropriate health benchmark values. In general, this hierarch y places greater weight on EPA derived health benchmarks than those from other agencies (http://www.epa.gov/ttn/atw/nata1999/99pdfs/healtheffectsinfo.pdf). For the reasons provided above, we belie ve that the lead NAAQS establishes an appropriate benchmark for addressing acceptability of risk and we therefore disagree with the commenter that we should instead use an ambient concentration of 0.02 μg/m 3 based on a one month average. **Comment :**  Commente r 98 cited the following from the preamble to the proposed rule regarding environmental risk from this source category for HAPs other than lead: With respect to potential for adverse environmental effects from non PB

- HAP, we note that there is a lack of information about specific adverse environmental effects occurring at a given concentration of HAP for this source category
. However, given that all chronic non

- cancer HQ values considering actual emissions are less than 1 using human health reference values, we believe that it is unlikely

that adverse environmental effects would occur at the actual HAP concentrations estimated in our human health risk assessment. The commenter noted that the EPA provides no explanation as to why its conclusion regarding environmental risk from non

- PB HAPs is true. The commenter further noted that the EPA has recognized the need to look at emissions above the actual level for human health. The commenter stated that the EPA must perform an ecological risk assessment and m ay not simply rely on the human health assessment without a reasoned explanation for doing so. The commenter noted that chemicals that are persistent in the environment or bioaccumulate in living tissue will remain or increase over time. Therefore, addi tional exposure would be added to a background that is likely already unsafe for wildlife and other environmental resources. L ack of human health risks from inhalation does not mean that the EPA can conclude that there would be no effects to wildlife or o ther natural resources either90

form inhalation or air deposition of HAP emissions, exacerbated b y persistence and bioaccumulation. **Response :**  First, the secondary NAAQS for lead, which is requisite to protect public welfare from known or anticipated adverse effects, is identical to the primary lead NAAQS. Thus, in meeting the controls for lead (which also result in co - control of all other non

- m ercury HAP metals) emissions will be controlled to levels less than allowed by the secondary

lead NAAQS. Second, EPA is to adopt more stringent standards directed to adverse env ironmental effects only

upon taking into consideration “costs, energy , safet y, and other relevant factors”. As discussed as part of the ample margin of safety analy sis, EPA has determined that these factors militate against adopting any further controls (and reached a similar conclusion based on similar factors in its section 112 ( d)(6) anal ys is) and this same reasoning applies with respect to adopting further controls to prevent adverse environmental effects. Moreover, without specific information about how, and at what concentration a given HAP affects a given ecological receptor , the EPA is unaware of how it could have performed a separate ecological risk assessment. As noted b y the commenter and in the risk assessment document, we generall y conclude that for non PB

- HAP, if all chronic non

- cancer HQ valu es are less than 1 using human health reference values, than we believe that it is unlikely that adverse environmental effects would occur. However, we disagree with the commenter that we do not provide a rationale for this judgment. The risk assessment states in section 2.5: Human health dose

- response reference values are generall y derived from studies conducted on laboratory

animals (such as rodents) and d eveloped with the inclusions of uncertainty factors that could be as high as 3000. As a result, these human reference value s are often significantly lower than the level expected to cause an advers e effect in an exposed rodent. It should be noted that there is a scarcity of data on the direct atmospheric impact of these HAP on other receptors, such as plants, birds, and wildli fe. Thus, if the maximum inhalation hazard in an ecos ys tem is below the level of concern for humans (i.e., is b elow the human health reference value which is itself a lower reference value than would be expected for an ecologic ef fect), we have generally concluded that mammalian receptors should be at no risk of adverse effects due to inhalation exposures from non PB
- HAP, and have assurance that other ecological receptors are also not at any significant risk from direct atmospheric impact. With respect to the potential for ecological risk associated with PB

- HAP, we note that our multipathway

anal ys is indicated that all chronic non

- cancer HQ values were less than 1 using human health reference values. Thus, we believe that it is unlikely that adverse env ironmental effects would occur considering actual emissions . W e further believe this is a reasonable91

interpretation of the multipathway anal ys is given a lack of information on the effects of PB
- HAP on specific ecological receptors. Finally , we agree with the commenter that the potential for ecological effects should be noted when considering MACT

- allowable emissions. Thus, when HQ values are greater than 1 considering MACT allowable emissions, we note that there is at least some potential for ecological effects. **3.2.2 Emissions Used**  **Comment :**  Two commenters ( 90 , 96 ) stated that the EPA ’s risk review is invalid because it fails to consider the reduction in dioxin and arsenic risks that would occur with the use of the proposed additional controls. The commenters compared the dioxin concentrations and risks to background dioxin concentrat ions and risks for the entire US populations and concluded that dioxin emissions from secondary lead smelters produce a contribution to the environment that is “not distinguishable from background concentrations.” The commenters contend that additional co ntrols on dioxin emissions from this source category will result in less than a 1% reduction in an exposed individual’s risk. With respect to arsenic, the commenters stated that the average background levels of arsenic in urban air (20 to 30 ng/m 3 ) result in inhalation risks between 35 and 50

- in

- 1 million, similar to the MIR risk that the EPA yi elded for the secondary lead smelters. The commenter contends that the EPA should demonstrate how arsenic emissions from the secondary lead smelting industry

would affect the extant risk from arsenic. **Response :**  The EPA disagrees with the commenters that it did not conside r reductions in risk after the proposed controls. Section 3.3 of the draft risk assessment document is titled: “Post
- control risk characterization” and it describes the estimated risks after potential controls are in place. Moreover, we note that the risk estimates calculated by the EPA are those associated with emissions from the source category. Similarly , risk reductions estimated after considering the proposed controls are based on estimated reductions in emissions from the source category . Thus, the estimated risk reductions de scribed in the draft risk assessment and preamble are independent of the background levels for a given HAP. **Comment :**  Commenter 98 stated that the EPA ’s failure to recalculate the risk assessment after changing its fugitive dust estimates is problematic gi ven that the EPA ’s modeling shows that fugitive emissions are the largest contributor to risks from this source92

category . The commenter further stated that because the EPA failed to “test or provide a reliable accounting for its measure of fugitive dust e missions...”, it has underestimated risk and should compensate b y setting a stronger standard. **Response :**  We have updated the fugitive emissions based on corrections received in public comments. However, we disagree that the methodology used for calculating f

ugitive emissions are underestimating emissions or risk and require a stronger standard. The estimates provided b y some facilities were unrealistically low and we developed the methodology to better account for fugitive emission levels as described in the proposal. See 76 FR at 28038. However, the estimates of fugitive emissions which EPA developed were overstated due to an error in the emission estimate for Exide Frisco, which was used to calculate estimates for the other facilities. The recalculated (and reduced) fugitive emission estimates led to a slight decrease in the risks due to fugitive emissions ; however, we disagree that the methodology was fundamentall y flawed in a way that would yield an underestimate of risk. **Comment :**  Commenter 98 stated that failing to include MACT

- allowable emissions in the multipathway

risk assessment is a “glaring inconsistency in the EPA ’s anal ys is that is arbitrary and capricious. The commenter contends that relying on actual emissions does not sufficiently protect populations living near the smelters, which have a range of emissions and may exceed levels allowed by the MACT standard. **R esponse**  **:** W e did not have detailed enough information to perform a multipathway risk assessment considering MACT allowable emi ssions. In fact, for dioxins and furans as well as for mercury there wa s no MACT standard in the 1997 NESHAP and thus, we would be unable to calculate MACT allowable emissions for th ese pollutant s . Ho wever , as noted in the proposal preamble , the proposed limit for dioxins and furans and mercury would lower multipathway risk somewhat and would also ensure that multipathway risks associated with dioxins and furans and mercury did not increase. See 76 FR at 29064. **Comment :**  Three commenters ( 80 , 90 , 91 ) noted that the docket did not contain the data inputs to the AERMOD and Human Exposure Model (HEM

- 3) and that they were thus unable to properl y comment on the methods or results of air dispersion and risk modeling. Commenter 90 supplied a list of techni cal documents not available that included stack test reports, survey responses, and underl yi ng data sets. **Response :**  The EPA disagrees with the commenters. The docket contains model input information that could be used to replicate the HEM

- 3 results. T his include s emissi ons and93

emissions location information
. Disks with the technical documents mentioned by the commenters were sent to the Docket Center; however, CD availability was not posted because some of the test reports included in the disks contain ed confidential business information
. **3.3 Baseline Emissions Estimates**  **3.3.1 Fugitive Emissions Estimates**  **Comment :**  Commenters 90 , 91 , and 96 stated that the EPA ’s factoring approach for estimating fugitive emissions is methodologically unsound. The EPA classified each facility as Level 1, Level 2, or Level 3 based on the degree of fugitive emissions control implemented at each facility . The commenters claim ed that the EPA failed to take into account the fact that Exide Frisco itself is a Level 2 fa cility , meaning that the EPA effectivel y used the “wrong common denominator” for each facility . This resulted in overstating emissions from Level 3 facilities and understating emissions from Level 1 and Level 2 facilities. Commenter 80 stated that there is no description of the method the EPA used to determine scaling factors, nor how the calculation was verified. **Response :**  Although the Exide Frisco facility was classified as a level 2 facility , the enclosures at the Frisco facility were limited to the m aterial handling area. For this reason, the facility had many

similarities to the facilities classified as level 1
. In an attempt not to overstate or understate emissions from any facilities by

a large amount, a decision was made to perform the calculati ons as described in the Development of the RTR Emissions Dataset for the Secondary

L ead Smelting Source Category document available in the docket. We also note that the scaling factors were partly based on confidential business i nformation that was not ap propriate to publish
. **Comment :**  Commenters 80 and 94 stated that the fugitive emissions estimate for the Exide Forest City

facility is over an order of magnitude higher than the NEI estimate of 0.06 tons per year and that such an overestimation calls into question the reliability of the EPA ’s estimates. **Response :**  Because of their nature, fugitive emissions are not readily measurable
. The National Emission Inventory (NEI ) estimates for this source category were inconsistent and unreliable for man y facilities. The estimates used for the Exide Forest City facility were developed using the same methodology that was used for the other facilities in this source category . We no te that although ambient lead data is not available near the Exide Forest City facility , a comparison of modeled and actual ambient lead concentrations for those facilities that94

did have ambient monitors located nearb y indicated that our estimates of fugit ive emissions were reasonable. See Residual Risk Assessment for the Secondary Lead Smelting Source Category and Summary of the Ambient Lead Monitoring Data near Secondary Lead Smelting Facilities , available in docket ID EPA
- HQ
- OAR
- 2011
- 0344. **Comment :**  Comm enter 93 stated that the use of both ambient air data and TRI emissions data to estimate fugitive emissions at the East Penn Manufacturing facility is inappropriate since East Penn operates six lead

- acid battery manufacturing facilities in addition to its secondary lead smelting sources. The commenter stated that considering that East Penn has managed a reduction in emissions of HAP to levels at or below the numerical limits of all applicable standards while operating several lead

- acid battery manufacturin g sources in addition to its secondary lead smelting sources, the EPA ’s assertion that fugitive dust emissions are the largest contributor to the risk due to lead emissions is overstated. **Response :**  The absolute amount of emissions from fugitive sources i s not directly measurable and therefore can onl y be estimated. We acknowledge that the fugitive emission s from the secondary

lead manufacturing process at East Penn may be lower than the estimates used for the development of this rule; this has been taken into acc ount in our revised estimates. We note that the East Penn facility is a well controlled facility that utilizes total enclosur e to control fugitive emissions from the majority of the manufacturing process
. Itis a facility that has demonstrated the level of control we believe is necessary to reduce fugitive lead emissions from this source category to an acceptable level. We performed dispersion modeling based on emissions from the East Penn facility . Our modeling did not include emissions from nearb y facilities that are not within the same contiguous property boundary . The dispersion modeling showed that emissions from East Penn’s secondary lead smelting operations yield ambient concentrations well below the NAAQS. See Table 1 in the preamble for the final rule, showing that East Penn’s emissions are about 1/10 th the NAAQS. **Comment :**  Commenter 98 stated that it is inappropriate to call the EPA ’s fugitive emissions estimates “actual”. The commenter claims that the EPA should measure fugitive dust e missions, such as through ambient monitoring. If estimates are used, the commenter stated that the EPA should use actual ambient monitoring data and conservative factors to make up for uncertainty created b y the failure to measure directly
. **Response :**  The nature of future emissions makes them impossible to directly measure. Based on a comparison of modeled ambient lead concentrations with actual ambient monitoring95

data near the secondary

lead smelting facilities, we believe that our estimates of fugitive emissions for this source category are reasonab le . Therefore, we disagree that it is not appropriate to regard the se estimates as “actual” emissions . (In an y case, this comment is somewhat semantic. Whether referred to as actual or estimated actual emissions, EPA has explained above, and in detail at 76 FR 29038, why its estimates for fugitive emissions are reasonable.) **3.3.2 Stack Emissions Estimates**  **Comment :**  Commenter 98 stated that the EPA should not refer to its emissions estimates as “actual” emissio ns for the following reasons: (1) the EPA failed to collect emission test data for all stack emissions or all pollutants; and (2) the EPA failed to account for potential malfunctions and exceedances of the standard. **Response :**  We disagree that the emission estimates should not be referred to as “actual” emissions. The emissions estimates were calculated based on the best available stack test data in all instances where stack test data was available. If stack tests for a certain source were not available, we assigned emissions to the source based on the closest match for a similar source for which test data was available. We disagree with the commenter that emissions that exceed standards and are violations, whether or not caused b y malfunction events, should be considered as part of the risk anal ys is. The purpose of the risk review is to evaluate whether the emission limits

-- the “standards p romulgated pursuant to subsection (d)” not the non

- compliance with those standards (section 112 (f)(2)(A)

-- should be made more stringent to reduce the risk posed after compliance with the underlying MACT standard. To the extent that a source is violating the underlying MACT standard, no tightening of the emission standard under the residual risk rule will avoid or mitigate against such violations 15 . In other words, a source that is violating the MACT emissions standard promulgated under section 112(d) woul d not be any more likel y t o be able to avoid such violations and comply

with a different presumabl y more stringent standard promulgated under section 112(f). Such events are violations and subject to enforcement b y the EPA, the States or citizens and an ac tion for injunctive relief is the most effective means to address violations whether or not they

are caused by

malfunctions if an emissions event poses a significant health or environmental risk.
15 In this regard, note that the affirmative defense for malfunctions is a defense to civil penalties only, not to liability. The malfunction event remains a violation.96

Although we disagree that emissions that result in a violati on should be considered as part of the risk review, we note that we believe malfunction events in this source category do not contribute significantly

to cancer or chronic noncancer risks for the source category in this rulemaking because malfunction event s in this source category are inherently short

- term and infrequent relative to annual operations and emissions. The commenter did not supply an y data to the contrary
. Furthermore, the conservative estimates built into the acute risk assessment are sufficient to gauge worst - case potential acute health effects. The conservative estimates built in to the assessment include worst

- case meteorology , emissions at ten times the maximum peak emission rate from all point sources simultaneously , and the sum of the max imum impact of each emission source, regardless of receptor location. Thus, even if we were to consider emissions that are in violation of the standard, we do not believe that they would result in any

different level of control than we are promulgating her e. **3.4 Compliance Timeline**  **Comment :**  Commenters 90 and 96 stated that s ection 112(i)(3)(A) establishes 3 years for compliance for “an y” section 112 standards, including those established under Section 112(f). The commenter cites the following excerpt from CAA §112 (i): After the effective date of any emissions standard, limitation or regulation promulgated under this section and applicable to a source, no person may operate such source in violation of such standard, limitation or regulation except, in the case of an existing source, the Administrator shall establish a compliance date or dates for each category

or subcategory

of existing sources, which shall provide for compliance as expeditiously as practicable, but in no event later than 3 ye ars after the effective date of such standard, except as provided in subparagraph (B) and paragraphs (4) through (8). The commenters contend that the EPA did not address CAA § 112(i)’s applicability

to the proposed rule. Instead, the EPA relied on 40 C.F.R. §63.6( f )(4 )(ii), which states that “the owner or operatory of an existing source unable to comply with a relevant standard established ... pursuant to section 112(f) ... may request that the Administrator grant an extension allowing the source up to 2 ye ars after the st andard’s effective date to compl y with the standard.” The commenters stated that CAA § 112(i)’s application is mandatory . The commenters noted that Congress used the word “any” in defining CAA § 112(i)(3)(A)’s97

applicability . According to the commenter, “ A broad construction of CAA § 112(i)(3)(A) mandates that this section, and the Administrator’s discretion for extension, apply to all regulations under CAA §112, including standards promulgated under subsections (d) or (f). The commenters further noted that 40 C.F.R. § 63.6(i)(4)(ii) applies only to standards set pursuant to section 112(f) and that while the EPA’ s proposed revised emission standard for lead is a section 112(f) standard, the design and work practice standards for fugitive emissions are also section 112(d)(6) standards, and dioxins and furans would be wholly

new standards set pursuant to section 112(d)(3). **Response :**  Section 112(i)(3) establishes the compliance timeframe for any standard issued under section 112 for existing sources and provide s that the compliance date shall be as expeditious as practicable but no later than 3 ye ars following the effective date of the standard. Section 112(f)(4), however, expressly provides more specific requirements for standards issued under section 112(f) an d thus for section 112(f) standards those more specific requirements (i.e. a specific requirement for section 112 (f) standards) govern in place of the more general compliance date requirements in section 112(i)(3). Specificall y, section 112(f)(4) provide s that a source cannot emit an air pollutant in violation of a standard issued under subsection (f) except that the standard will not apply until 90 day s after its effective date. It also provides that the Administrator may

grant a waiver for a period of up to 2 years from the effective date if necessary for the installation of controls and if measures will be taken in the interim to ensure public health is protected from imminent endangerment. As stated in the technical documents supporting the proposed rule, we do not believe that additional controls will be required for facilities to meet the new dioxin and furan standards. However, the two ye ar compliance date is appropriate to allow facilities the time needed to perform testing to determine whether they will need to modify existing control devices and complete such modifications, if necessary , to comply with the standard for dioxins and THC
. See also 76 FR at 29064/1 explaining why it is possible for EPA to find at this time that sources need two ye ars to comply with the risk

- based standards for metal HAP
. **Comment :**  Commenters 90 and 96 stated that a two year compliance schedule is insufficient and unrealistic based on the required controls set forth in the proposed RTR, particularl y the total enclosures. The commenters stated that for facilities that do not currentl y contain total encl osures, designs must consider efficient movement of materials between98

processing steps and the indoor work environment. The construction must also be carefully staged around the process equipment and it is likely that the large enclosures could only be co nstructed during scheduled periodic maintenance downtimes which are scheduled at least six months apart. **Response :**  As just stated, CAA section 112(f)(4) expressly provides specific requirements for compliance dates for standards issued under section 112(f) . Specificall y, section 112(f)(4) provides that a source cannot emit an air pollutant in violation of a standard issued under subsection (f) except that the standard will not apply until 90 day s after its effective date. It also provides that the Administrator may grant a waiver for a period of up to 2 years from the effective date if necessary for the installation of controls and if measures will be taken in the interim to ensure public health is protected from imminent endangerment. Two years has been pro vided for compliance with the rule given that the two year period is necessary to install controls. **Comment :**  Commenters 90 and 96 stated that the facilities are facing obligations to attain the 2008 lead NAAQS and require time to determine the degree to which these obligations overlap with the NESHAP implementation in order to develop appropriate design and construction plans. **Response :**  CAA section 112(f)(4) expressly provides specific requirements for standards issued under section 112(f). Specifically , s ection 112(f)(4) provides that a source cannot emit an air pollutant in violation of a standard issued under subsection (f) except that the standard will not apply until 90 day s after its effective date. Italso provides that the Administrator may grant a waiver for a period of up to 2 years from the effective date if necessary for the installation of controls and if measures will be taken in the interim to ensure public health is protected from imminent endangerment. Two years has been provided for compliance with the rule given that the two year period is necessary to install controls. **Comment :**  Commenters 90 and 96 stated that the EPA is engaging in numerous actions that affect other industry

sources (e.g., Boiler M ACT, Utility MACT, other RTR actions) that will increase the cost of compliance b y increasing the demand for construction services. **Response :**  We believe that it is unlikely that any of the mentioned actions will impact the availability

of the necessary

se rvices to the secondary lead smelting facili ties. The commenter provides no evidence to the contrary
. Nor does the comment provide details as to99

how these other actions impact the compliance dates set forth in the CAA for section 112(f) standards. **Comment :**  Commenters 90 and 96 stated that it is possible that the EPA could take the position that for an area to be designated as attaining the lead NAAQS, the monitored ambient lead levels for the three years before November 2015 must be below 0.15 μg/m 3 on a three

month rolling average. If ambient lead levels must be below the NAAQS by November 201 2 , then a final rule promulgated in earl y 2012 would not allow time for NESHAP control measures implemented by

March 2014, to provide for timely NAAQS attainment. The commenter further stated that “an EPA position that states must demonstrate attainment of the NAAQS based on the three

- month average over a three year period before the NAAQS attainment deadline would be contrary to the Clean Air Act.” The commenter a sked that the EPA clarify

its position with respect to the NAAQS

-NESHAP compliance timeline and state that the NAAQS measures do not need to be implemented to reach the ambient standard until the attainment year . **Response :**  The CAA clearly presents the comp liance dates for standards promulgated under section 112(f). We also note as a point of information that the CAA requires areas to attain the various NAAQS as expeditiously as practicable, but no later than specified dates. For the 2008 lead NAAQS, areas are required to attain the standard as expeditiously as practicable, but no later than December 31, 2015. The Act not only contemplates but requires, if practicable, for areas to attain the 2008 lead NAAQS earlier than December 31, 2015. Furthermore, no a ction EPA is taking in this rulemaking changes, modifies, or otherwise bears upon legal obligations to attain the lead NAAQS. **Comment :**  Commenter 98 stated that the two year compliance schedule for the proposed RTR is unlawful. The commenter stated that th e two year compliance date violates the plain text of Sections 112(f)(3)

- (4) which requires immediate compliance for new sources and a 90

- day compliance date for existing sources. The commenter stated that under section 112(f), individual facilities may

f ile an application for a 2

- ye ar extension of compliance. The EPA must then evaluate each request on a case

- by

- case basis. The commenter stated that the EPA is not authorized to grant a Section 112(f)(4) “waiver” to a category of facilities without going through the case

- by

- case process
– application, submission of specific information, participation by affected communities

-- set out in EPA’s implementing regulation . The commenter stated that the EPA ’s proposal also violates section 112(f)(4) because the EPA ’s record included no100

evidence that statutory

factors are met. The commenter stated that the document entitled “Estimated Time Needed to Achieve Compliance” was not available in the publically viewable docket when checked by

the commenter on July

12 and July

25, 2011. The commenter stated that the record does not state how many sources need two ye ars to compl y, or whether faster compliance may

be possible for sources like Quemetco, Inc. in City of Industry , CA that have already reduced their emissions to low levels. The commenter further stated that even if the document provided information that any facility may need additional time, the second statutory factor bars the compliance delay proposed by the EPA because there is “no evidence in the record that the necessary

“steps” will be taken during the additional two years “to assure that the health of persons will be protected from imminent endangerment.” The commenter stated that even if the compliance delay were justifiable for existing sources, exte nding the delay for new sources violates the plain text of the statute. The commenter further stated that the EPA has already delayed satisfying its legal duties by failing to begin this rulemaking until 2011, and that the EPA has no lawful justification to delay the compliance date any

longer. **Response :**  EPA is of course aware of the requirements of section 112 (f)(3) and (4). See 76 FR at 29064/1. EPA is not ignoring the requirements of this provision. Rather, as documented in the memorandum Estimated Time Needed to Achieve Compliance with the Proposed Revision to the MACT standard for Secondary Lead Smelters , EPA has made case

- by

case findings for each existing source as to the amount of time required to comply with the risk based stack and f

ugitive emission standards for metal HAP. 16 EPA does not interpret section 63.6 (i)(4)(ii) of its regulations to mandate individual applications when all of the necessary information is already before EPA and EPA applies that information in an individualiz ed, case

by

- case manner, as done here. Moreover, section 112 (f)(4)(B) is a direct grant of authority which can be implemented not just by regulation but by

other EPA action, as done here. As documented in the memorandum cited above, the existing sources discussed in the memorandum will need to undertake such improvements as construction of enclosures, and replacement of baghouses (with such attendant interim steps as obtaining capital, purchase and delivery of equipment, installation of equipment, and sh akedown operation). These activities simply cannot be accomplished in 90 days, and two ye ars is a reasonable amount of time to carry them out. 17

16 EPA does not understand the commenter’s inability to locate this memorandum. It was posted to the docket on May 19, 2011. 17 The commenter points out that the Quemetco facility was given a 9 month compliance period to meet stringent standards adopted by the South Coast Air Quality Manage ment District. This is accurate on its face, but EPA’s101

The statute likewise contains the requirement that EPA must find that “steps will be taken during the period of the waiver to assure that the health of persons will be protec ted from imminent endangerment” in order to extend the compliance date. We note first that EPA does not believe that an y unacceptable risk under section 112 (f) automatically equates to an “imminent endangerment”, given that Congress authorized extensions of the compliance date. We note further that existing secondary lead sources are already

controlled to some degree, and will necessaril y make further reductions of their emissions as they imp lement steps toward full compliance. For example, fugitive emissions will be reduced as total enclosures are constructed; fugitive emissions will also be reduced as work practices are phased in. Emissions will also be reduced during the pre

- compliance pe riod as sources upgrade baghouses and develop means of better maintaining them. Under these circumstances, the EPA believes that steps will indeed be taken in the period before full compliance to reduce emissions and prevent an imminent endangerment. Fi nally , the commenter correctl y points out that no extension of time for new sources is permissible under the statute. The compliance date for new sources to meet the section 112 (f)(2) standards is consequently are immediatel y s ubject to the standard. **3.5 P**  **erformance Testing 3.5.1**  **Testing Frequency Comment**  **:** Commenters 80 and 86 stated that language in § 63.543(4) implies that testing must be done on a monthly basis while § 63.543(5)(f) makes it clear that testing must be done on an annual basis; the commenter as ks for clarification. Commenters 90 and 96 state d that their understanding is that testing is required on an annual basis while the average emissions are calculated monthl y based on the most recent annual stack tests; the commenters ask that the EPA confirm that this is the intent of the proposed rule. **Response :**  The commenters are correct in their understanding that testing is required on an annual basis while the average emissions are calculated monthly based on the most recent annual stack tests.

information is that the facility had commenced the needed improvements well before the 9 month period started to run, so that 9 months is not a fair measure of the time actually needed for the compliance upgrades. In fact, in comments on the proposed SCAQMD rule 1420.1, this facility requested a tighter point source emission limit for lead than SCAQMD proposed.102

**3.5.2 Continuous Emissions Monitoring Systems (CEMS)**  **Comment :**  Commenter 84 recommended that the EPA require enhanced monitoring sy stems for lead on both existing and new secondary lead smelting facilities. The commenter noted that congress mandated the EPA in the CAA to use enhanced monitoring s ys tems when available. The commenter further contend s that direct measurement of lead and other HAP metals is essential for the EPA to comply with the intent of the CAA and to evaluate residual risk and improvements in control. The commenter noted that new prove n , commercial monitoring technology

for continuous measurement of lead and other HAP metals including mercury is available. Commenter 81 stated that the most significant and relevant observation impacting this p roposed rule is that there appears to be no threshold for lead exposure below which no health effects are observed. The commenter contends that timely feedback regarding emissions is therefore particularl y important because of the potential of fumigation from relatively low stacks and the potential for secondary lead smelting facilities to produce significant dose exposures over short tim e periods. The commenter stated that significant advances in continuous metals monitoring technology

have been made sin ce the last NESHAP and provides evidence that near

real

- time monitoring of lead and other metal HAP is commerciall y available. Commenter 81 stated that installation of a multi

- metal CEMS would eliminate the EPA concerns over the effectiveness of baghouses in capturing mercury and would eliminate the need for a BLDS as well as the need to measure mercury content in scrap metals. The commenter further stated that installation of a multi

- metal CEMS would alleviate concerns over possible arsenic emissions. Th e commenter also suggested that if the EPA does not require CEMS for stacks, they

should require at least two ambient near

- real

- time lead monitors. In response to the EPA ’s stated concerns about the costs associated with lead CEMS, commenter 81 stated that “there are costs associated with no action” and that “the real problem is not that a number of stacks might require CEMS, but that there are too many low level stacks contributing to fumigation event s in the local neighborhoods.” The commente r suggest ed that one potential strategy

would be to direct these low level stacks to a common stack that could then be monitored with a single CEMS. The commenter contends that “most secondary lead smelters are relativel y s mall...”, so that the cost to duct emissions to a common stack “should not be too high, particularly in comparison to the cost of monitoring all stacks individually .”103

Commenter 81 stated that the lack of a performance specification for a lead CEMS is not a justifiable reason for not requ iring them. The commenter noted that the lack of a published performance specification did not prevent the EPA from requiring mercury CEMS or HCl CEMS for coal fired power plants . The commenter further noted that the performance specification and QA proced

ure for multi

- metal CEMS are currently available on the EPA ’s website. The commenter stated that modifying these performance specifications specifically for a lead CEMS could be easil y completed. Commenter 81 noted emissions during start

- up, shutdown, and /or malfunctions can represent a significant fraction of a plant’s emissions. The commenter contends that it is critical to be able to monitor emissions during SSM periods and that it is impossible to do so unless a CEMS is in place. Commenter 85 provided data regarding an X

- ray fluorescence based multi

- metals continuous emissions monitor. The commenter also provided proposed performance specifications and on

- going QA procedures for lead CEMS. Commenter 85 also later submitted comments requesting that th e EPA comment on all aspects of its original comments, citing specificall y the adequacy of the presented data in demonstrating the feasibility of using the Xact as a Pb CEMS, the feasibility of the performance specifications, on

- going quality assurance pro cedures, and the submitted traceability protocol, and an y changes the agency feel may be necessary to assure the data quality of Pb CEMS. The commenter also states that the Xact instrument cost is $141,665 with an annual operating cost of $10,693. **Respons e**  **:** Itis not appropriate to require lead CEMS for new or existing sources absent a promulgated performance specification for this technology . There is not a numerical standard for HAP metals other than lead; therefore, the effectiveness of a CEMS at measuring these metals is not relevant to compliance with subpart X. We also note that measuring mercury content in scrap metals is not required b y this rule, so it is unclear how the presence of a CEMS capable of measuring mercury would affect a facility

with r espect to measuring mercury content in scrap. With respect to facilities reconfiguring their stacks to make their facility more amenable to CEMS and prevent emissions from shorter stacks, we note that the risk assessment considered risks from all stacks, regardless of height and the results were considered in our decision making regarding the lead emission limit. The process of developing a performance specification for a monitoring method involves a period of notice and comment. Since a performance specifi cation104

was not included in the proposed rule, the public was not provided with an opportunity to comment on the performance specification provided by the commenters after the proposal. The performance specifications provided by the commenters have been pro vided to the appropriate EPA staff. However, we do not find it appropriate to approve the performance specifications in the context of this final rule without first providing the public an opportunity to comment. With regard to the commenter’s request that the EPA respond to the specific issues raised in their late comments, we reiterate that a lead CEMS performance specification must be proposed and finalized as a rulemaking action and the issues raised by the commenter are best addressed through that rule making. When such a performance specification is proposed by the EPA, the public will have the opportunity to comment on the ty

pes of issues raised in the commenter’s letter, such as ongoing quality assurance procedures and traceability protocols. These is sues are best addressed through that rulemaking. The technical basis of the performance specification will be evaluated b y EPA staff when developing the proposed performance specification for this technology
. Subsequently , the application of a lead CEMS to demonstrate compliance in this rulemaking must be evaluated with respect to whether the current form of the emission standard (based on manual test data) is appropriate. **Comment :**  Commenter s 90 and 96 commented on data and comments submitted by Cooper Environmental Services and Pall Corporation regarding a commercially available lead CEM. The commenters note that Cooper Environmental Services informed the ABR that the CEM cost approximately $400,000 p er stack to install, a cost that the commenters claims is extreme ly high and would be multiplied many times over as facilities in this industry t ypicall y have 7

- 8 stacks. The commenters note further concern that the price of a lead CEM could rise if the E PA requires it as the technology is onl y offered by one compan y. The commenters stated that there is no discussion in the record justifying the need for advances in monitoring and surveillance on stack sources in this industry , nor is there an y indication that the BLDS technology that is currently

required is inadequate. The commenters claim that Cooper Environmental Service’s comments are “rife with irrelevant and incorrect information”. The commenters further noted that Cooper Environmental Service’s co mments regarding multi

- metal CEMS are irrelevant as the EPA neither proposed multi

- metal CEMS nor requested comment on their applicability
. **Response :**  We agree that measurement of HAP metals other than lead is not necessary for compliance with subpart X and therefore not relevant to this rulemaking. We have considered105

the cost estimates provided by all commenters and maintain that it is appropriate to include the requirement for lead CEMS for new sources. However, this requirement will not be effective until a lead CEMS performance specification has been promulgated. **Comment :**  Four commenters ( 90 , 93 , 95 , and 96 ) stated that the EPA should abandon its proposal to require CEMS for new and modified sources. The commenters stated that because the EPA has not s et forth a performance specification for a lead CEM, stakeholders are unable to assess the s ys tems and their applicability to this industry . The commenters also argued that the EPA must assess cost - effectiveness under Section 112(f)(2)(A). The commenters stated further stated that the EPA ’s analy sis of technological feasibility for CEM is inadequate. The commenters also express concern over using a different method to show compliance than the one used to set the standard. The commenters further stated that lead CEMS should not be included in Subpart X until performance specifications and procedures are promulgated and feasibility and effectiveness on secondary lead smelters has been demonstrated. **Response :**  A performance specification for lead CEMS will be promulgated prior to the requirement becoming effective in this subpart. The process for promulgating a lead CEMS method includes proposing such a method and providing the opportunity for public comment
. In addition, EPA would consider as part of the r ulemaking proceeding, whether it is appropriate to adjust the level of an y standard measured b y a CEM considering the more frequent measurement and hence dampening of variability over time of multiple measurements.
**3.5.3 Bag Leak Detection Systems (BLDS)**  **Commen t**  **:** Commenter 90 stated that the current language in § 63.543(f), (g), and (h) require annual compliance testing for lead, THC, and D/F for all process vents. The commenter contends that the term process vent in the proposed rule includes sources that are either not suitable for testing given their configuration or do not have emissions limits in the proposed rule. The commenter stated that D/F and THC testing should be limited only to those sources that have emission limitations on D/F and THC. The commenter further stated that the Johnson Controls facility will utilize filtered roof exhausts that do not have stacks that allow measurement of velocity or meet isokinetic sampling requirements under EPA Method 29. The commenter stated that the followin g sources should be excluded from the definition of process vent: roof exhausts equipped with HEPA filters, vents106

from buildings that are not partial or total enclosures, and building vents from non

- lead bearing process areas. **Response :**  We have revised th e proposed regulatory text to clarify

that compliance tests need onl y be conducted for those sources that have emissions limitations for the applicable pollutant. We agree that building vents from non

- lead bearing process areas should be excluded from the definition of process vent and have reflected such in the regulatory text. However, we disagree that all roof exhausts equipped with HEPA filters should be excluded from the definition of process vent. **Comment :**  Commenter 93 stated that the requirement f or monthly

calculation of flow

weighted average emissions is unnecessary and represents an additional burden without be nefit. The commenter argued that sources will ty picall y schedule the annual compliance tests for all process vents at a facility in the same week, and therefore, the results produced by the monthly calculation will not change over a period of nearly a ye ar. Therefore, requiring the facilities to perform complicated summation calculations for multiple process vent stacks each month when th e results each month will be the same provides no additional benefit or assurance of compliance with the standard. **Response :**  We disagree that performing a calculation of flow

- weighted average emissions is complex or represents an unnecessary additional burden. We understand that it is possible that facilities may test different process vents at different times throughout the ye ar. Calculating the flow

- weighted average emissions on a monthly basis will ensure that the value consistently

includes the most up - to - date stack test data available. **3.6 Typographical Corrections**  **Comment :**  Commenter 92 requested clarification on a footnote of Table 2 that references January 2010 NEI data as being the basis for which emissions from this source category were estimated. T he commenter stated their understanding that the NEI is developed on a 3

- ye ar cycle and that 2010 is not one of the development ye ar s . The commenter further stated that since the 2005 NEI data was used in the risk assessment, an explanation as to why an a lternative ye ar was utilized in the socio

- economic anal ys is should be provided. **Response :**  The commenter is correct that 2010 is not a development ye ar. The 2005 NEI data was used for the socio

- economic anal ys is
.107

**3.7 SSM and Affirmative Defense**  **Comment :**  Comme nter 98 agreed with the EPA in the removal of the unlawful malfunction exemption under the existing rules, but noted that the EPA failed to assess cancer and non

- cancer chronic health risk from malfunction or other violations of the MACT standard. Specificall y; EPA must consider the full potential for risk from all emissions that are likely to occur, even though the standard is in place, not just the risk based on the “allowable” number of emissions. EPA acknowledges that malfunctions inevitably occur. EPA has information available or can collect information on major sources’ malfunction and violation history . Research b y the Environmental Integrity Project (“EIP”) from 2004 found that significant emission exceedances occur routinely , across a range of different industries. Moreover, EIP found that “releases from upsets actually dwarf a facility ’s routine emissions. EPA must l ook at data, like the EIP report, and ensure that its risk analy sis and resulting standard prepare for the likelihood that malfunctions will occur and that the public will need protection from the high emissions they

cause. EPA cannot ignore the additiona l emissions from malfunctions or other violations in calculating risk. It may not assume that malfunction or other violation

- based emissions are zero when it knows that they are not and when its own proposal is likely to perpetuate the problem of malfuncti ons in overburdened communities. For the purpose of assessing health risk, EPA cannot presume that a facility will be in full compliance with the standard at all times, as this runs counter to past history
. By failing to account for the heightened risk from exceedances of the MACT in its calculation, EPA fails to consider the full risk to public health and the environment from this source, especiall y for the maximum exposed individual and most

- affected communities. This violates section 112(f)(2). The Act specificall y requires EPA to base its risk anal ys is on the highest possible level of108

risk “to the individual most exposed to emissions from a source in the category or subcategory .” 42 U.S.C. § 7412(f)(2)(A); § 7412(f)(1)(C). To do this, it is necessary fo r EPA to determine the highest level of potential emissions from the worst - performing source, and then use that information to establish the maximum individual risk. That requires consideration of risk from malfunction

- and other violation

- based emissions. Heightened emissions that occur during a malfunction and other types of violations pose increased acute health risks, as EPA has recognized. 76 Fed. Reg. at 29,040. Chronic cancer and non

- cancer health risks may also be more severe than those calculated b y EPA because of malfunction/violation emissions. For example, EPA’s MIR (maximum individual risk of cancer) is based on the assumption that exposure is constant for a lifetime (unless EPA uses age dependent adjustment factors). Failing to look at the true potential for spikes will significantl y underestimate the amount of emissions considered for this anal ysis. EPA has accounted for some risk beyond the “MACT allowable” emission level in its acute health risk assessment, demonstrating that it is necessary and appropriate to do so for all parts of the risk assessment. To calculate acute health risk, EPA is using a “worst

- case” scenario approach that appears to include some accounting for additional health risk due to upsets, malfunctions or other exceedances of the standard. For acute health risk, EPA is using a peak hourly emissions number that is “10 times the average annual hourly emissions rate for that source.” 76 Fed. Reg. at 29,040. EPA’s use of a factor that accounts for risk beyond the “MACT allowabl e” emissions number for acute risk in some manner in the proposed rule demonstrates that EPA has found a method to account for risk from higher than allowable emissions that occur from malfunctions and violations. It must apply

a similar method to assess the maximum lifetime cancer risk and chronic non

- cancer health risk for the maximum exposed individual. The failure to do so violates § 112(f)(2) and is arbitrary and capricious. The fact that EPA has done this for acute health risk shows that it is possibl e to do and should also be done for the other health risks that EPA must address in this rulemaking. Commenters also urge EPA to improve its acute health risk anal ys is by using a similar worst

- case factor for fugitive dust emissions as well as stack emiss ions.109

EPA cannot justify

ignoring the potential for increased fugitive dust emissions to occur as a result of a malfunction or violation, whether or not the malfunction is combined with low

- wind atmospheric conditions, as it attempts to do. 76 Fed. Reg. at 29,040. Further, accurately evaluating fugitive dust emissions is crucial because these emissions are the largest contributor to lead emission risks. See id. at 29,038. **Response** : We disagree with the commenter that emissions that exceed standards and are violations, whether or not caused b y malfunction events, should be considered as part of the risk anal ys is. The purpose of the risk review is to evaluate whether the emission limits should be made more stringent to reduce the risk posed after compliance w ith the underlying MACT standard. To the extent that a source is violating the underl yi ng MACT standard, no tightening of the emission standard under the residual risk rule will avoid or mitigate against such violations. In other words, a source that is vi olating the MACT emissions standard promulgated under section 112(d) would not be an y more likel y to be able to avoid such violations and comply with a different presumabl y m ore stringent standard promulgated under section 112(f). Such events are violation s and subject to enforcement by the EPA, the States or citizens and an action for injunctive relief is the most effective means to address violations whether or not they are caused by malfunctions if an emissions event poses a significant health or environmental risk. Although we disagree that emissions that result in a violation should be considered as part of the risk review, we note that we believe malfunction events do not contribute significantl y to cancer or chronic non

- cancer risks for the source cat egory in this rulemaking because malfunction events are inherentl y short

- term and infrequent relative to annual operations and emissions. The commenter did not supply an y data to the contrary
. Furthermore, the conservative estimates built into the acute ri sk assessment are sufficient to gauge worst - case potential acute health effects. The conservative estimates built in to the assessment include worst

- case meteorology , emissions at ten times the maximum peak emission rate from all point sources simultaneous ly , and the summation of the maximum impact of each emission source, regardless of receptor location. Thus, even if we were to consider emissions that are in violation of the standard, we do not believe that they would result in any

different level of control than we are promulgating here.110

**Comment :**  Commenter 98 noted that the affirmative defense is unlawful and unjust, would create a new unlawful loophole, would have harmful consequences for communities, undermines citizen’s rights, and will greatly reduce the deterrent impact of the standards: Commenters support EPA’s proposed removal of the start

- up, shut

- down, and malfunction exemption... However, EPA’s proposal to promulgate an “affirmative defense” to penalties due to a malfunction would create a new unlawful loophole. It also would have harmful consequences for local communities affected b y secondary lead smelters, and will greatl y reduce the deterrent impact of the proposed standards. The statute makes clear how the courts are to assess civil penalties, whether a case is brought b y EPA or a citizen. 42 U.S.C. § 7413(e). Congress plainly intended citizens to be able to enforce emission standards under the CAA using the full range of civil enforcement mechanisms available to the government, and, in the HAP context, subject only to the limitation that go vernment not be “diligently prosecuting” its own civil enforcement action, CAA § 304(b)(1)(B), 42 U.S.C. § 7604(b)(1)(B). EPA’s rule proposal, b y shifting this careful balance and contravening these mandates, violates the CAA. The affirmative defense that the EPA proposes to allow in case of malfunctions goes directly against congressional intent in two way s. First, Congress expressed a clear intent as to how judges should determine the size of civil penalties whenever they are sought and thus, under Chevron, U.S.A., Inc. v. Natural Res. Def. Council, Inc ., 467 U.S. 837, 842
- 43 (1984), flatl y barred the EPA from limiting when civil penalties can be assessed. In this proposal, the EPA acts outside of its delegated authority to limit civil penalties available in citizen suits or its own enforcement actions. Second, the proposal will impermissibly chill citizen participation, and the ability to win an effective, deterrent remedy , in CAA enforcement actions. The affirmative defense is fatally flawed because the EPA does not have the authority to decide when civil penalties will not be allowed. The CAA itself spells out the only limits that Congress intended to impose on citizens’ ability to seek and recover penalties in enforcement suits under CAA § 304, 42 U.S. C. § 7604. See 42 U.S.C. § 7413(e). By attempting to impose additional agency

- created limits, the EPA ex ceeds its authority . The commenter goes on to say : Congressional intent on civil penalties is clear

—they are a remedy

available to citizen plaintiffs, and judges have a list of factors to consider in assessing them. As such, EPA cannot interpret the statute to contravene that intent. By attempting to eliminate, via regulations, civil penalties in cases of malfunction where the violator demonstrates that certain factors [exist], EPA has done just that.111

The CAA grants EPA minimal discretion that only applies to administrative penalties, allowing EPA to “compromise, modify , or remit, with or without conditions, any

administrative penalty which may be imposed under [subsection 113(d)].” 42 U.S.C. § 7413(d)(2)(B). However, there is no similar grant of authority to EPA to compromise, modify or limit civil penalties that a court may impose under section 113(e) or section 304. Section 304(a), 42 U.S.C. § 7604(a), grants courts the sole authority “to appl y appropriate civil penalties” in citizen suits. The explicit reference to EPA’s ability to modify

penalties in one subsection and its absence in the other subsection of the same provision can only be understood as an intentional decision by Congress that EPA cannot contravene by rule. If a local community

group sued a covered facility for a violation of the emission standards, the owner might argue that it is exempt from paying civil penalties so long as the owner satisfied the requirements set forth in the EPA ’s proposed affirmative defense regulations. See 76 Fed. Reg. at 29,061

- 62 (proposing 40 C.F.R. § 63.552). The owner must not be able to evade civil penalties that apply when the congressionally mandated fact ors in the statute are met. 210 See 42 U.S.C. § 7413(e) (listing factors). It is improper for a court to fail to consider these factors, or to fail to make its own determination of what civil penalties are “appropriate” under CAA § 304(a), and the EPA shou ld not ask a court to ignore its legal duty. A fortiori it is impermissible for the EPA to attempt to displace those factors or in an y way alter their significance by

creating a bar to penalties if certain agency

- defined considerations are met instead.Ci tizen participation in CAA enforcement also will be hindered, in violation of citizens’ rights to protect themselves from pollution and in direct conflict with congressional intent. The affirmative defense would likely be used on a routine basis by pollute rs seeking to avoid penalties, just as the malfunction exemption was. As a result, citizens who seek the assessment of civil penalties against polluters in order to protect themselves and achieve the Act’s goals may be forced to engage in fact

- intensive di sputes over the cause of emission violations and adequacy of responsive measures

– an outcome Congress intended to prevent with the simple straightforward enforcement and penalty provisions in the Clean Air Act. As a result, enforcement of the Act could su ffer, for civil penalties provide a powerful deterrent to violators as Congress intended. As the Supreme Court explained: “To the extent that they [civil penalties] encourage defendants to discontinue current violations and deter them from committing future ones, they afford redress to citizen plaintiffs who are injured or threatened with injury as a consequence of ongoing unlawful conduct.” Friends of the Earth, Inc. v. Laidlaw Envtl. Servs. , 528 U.S. 167, 186 (2000).112

Thus, the affirmative defense al so runs counter to two clearl y expressed intentions of Congress: (1) the burden it places on citizens makes it less likely that they will enforce the Act, see, e.g. , Pennsylvania v. Del. Valley Citizens’ Council for Clean Air , 478 U.S. 546, 560 (1986); and (2) several of the factors at issue in the affirmative defense undercut Congress’s intent that citizen suit enforcement should avoid re

- delving into “technological or other considerations.” NRDC v. Train , 510 F.2d 692, 724 (D.C. Cir. 1974). Both result from the technical burden the EPA imposes on citizens with the affirmative defense, and both render the defense impermissible. In addition to these problems, there is simply no need for an affirmative defense to penalties to be written into the regulations a nd cause the harm that will result. EPA has discretion to decide what cases to prosecute, to consider settlements, and to request civil penalties in a case

by

- case manner, as long as it acts consistent with the Clean Air Act to protect clean air as its top priority , see 42 U.S.C. § 7401. Promulgating this affirmative defense is equivalent to giving polluters “get out of jail free” cards for serious emission exceedances and MACT violations. Polluters are likely

to claim that any

violation of the standard is due to a malfunction in order to evade the requirements. Allowing polluters to evade financial penalties

– which are the real teeth of the standards

– through this ty pe of measure is likely

to lead to polluters simply ignoring or factoring potential standard violations into their cost of doing business, rather than actually trying to prevent malfunctions and violations of the standards as a way to avoid financial losses from the application of penalties. Assuming arguendo that the EPA had authority to promulgate an y type of affirmative defense to penalties for malfunctions, the EPA should also promulgate the following provisions: 1. A specific amount of compensatory penalties should apply

to each reported malfunction (consistent with the Act). These funds should be dedicated to enforcement, inspections, and monitoring in the local community around the specific facility , to create greater assurance that malfunctions will not happen again. 2. The EPA should modify the regulations so that the affirmative defense cannot be used b y a specific facility or company

more than once within a set period of time, such as 10 years. The affirmative defense should become automatically unavailable to a facility

that has previousl y had a malfunction within the last 10 ye ars, to ensure that this defense does not swallow the value of the standards. 3. The EPA should promulgate specific public reporting and notification requirements for malfunctions, or any emission exceedance that occurs of which an operator is aware. Specificall y, the EPA should require that when a facility provides the EPA with a notification of a malfunction or emission standard113

exceedance under the regulations, this notice will be made publicl y available on the EPA ’s website withi n 14 day s. In addition, the EPA should promulgate the requirement that when such notification is made, the facility must also provide for community

notification of the malfunction or emission standard exceedance within 2 business day s, through an appropriate public forum that is designed to reach residents who live near the facility , including but not limited to a notice on the facility ’s own website (if it has one), a written notice to the local municipality and local school district, a press release to th e local newspaper, radio, and TV news station that contains information community members may need to protect themselves and their families from the additional air pollution. Commenters urge the EPA not to adopt an affirmative defense that undermines citi zen right and remedies under the Clean Air Act. People living near secondary lead smelters are expose d to unacceptabl y high levels of hazardous air pollution that no one should have to face simply because of where they live. Attempting to take away a right granted to citizens by Congres s through an agency regulation sets a dangerous precedent. The EPA should work to expand an d protect the ability of people harmed by

air pollution to seek all appropriate and available form s of relief in court. The EPA should not retract or weaken citizen rights and remedies, as this proposal does, by making it more difficult for people to win meaningful relief from facilities that have released toxic air pollution into their communities for years. **Response :**  As the EPA explain ed in the preamble to the proposed rule and in the response to comment document, the EPA recognizes that even equipment that is properl y designed and maintained can fail and that such failure can cause an exceedance of the relevant emission standard. The E PA included an affirmative defense in the final rule in an attempt to balance a tension, inherent in many t ypes of air regulation, to ensure adequate compliance while simultaneously

recognizing that despite the most diligent of efforts, emission limits may be exceeded under circumstances beyond the control of the source. The EPA must establish emission standards that “limit the quantity , rate, or concentration of emissions of air pollutants on a continuous basis.” 42 U.S.C. § 7602(k)(defining “emission limi tation and emission standard”). See generall y Sierra Club v. EPA , 551 F.3d 1019, 1021 (D.C. Cir. 2008) ( emissions limitations under CAA section 112 must both continuously apply and meet section 112’s minimum stringency

requirements, even during periods of startup, shutdown and malfunction). Thus, the EPA is required to ensure that section 112 emissions limitations are continuous. The affirmative defense for malfunction events meets this requirement b y ensuring that even where there is a malfunction, the em ission limitation is still enforceable through injunctive relief. While “continuous” limitations, on the one hand, are required, there is also caselaw indicating that in114

many situations it is appropriate for the EPA to account for the practical realities of technology
. For example, in Essex Chemical v. Ruckelshaus , 486 F.2d 427, 433 (D.C. Cir. 1973), the D.C. Circuit acknowledged that in setting standards under CAA section 111 “variant provisions” such as provisions allowing for upsets during startup, shutdown and equipment malfunction “appear necessary to preserve the reasonableness of the standards as a whole and that the record does not support the ‘never to be exceeded’ standard currently in force.” See also, Port land Cement Association v. Ruckelshaus , 486 F.2d 375 (D.C.Cir. 1973) . Though intervening caselaw such as Sierra Club v. EPA and the CAA 1977 amendments undermine the relevance of these cases today , they

support the EPA’s view that a s ys tem that incorporate s some level of flexibility is reasonable. The affirmative defense simply provides for a defense to civil penalties for excess emissions that are proven to be beyond the control of the source. By incorporating an affirmative defense, the EPA has formalized its approach to upset events. In a Clean Water Act setting, the Ninth Circuit required this ty pe of formalized approach when regulating “upsets beyond the control of the permit holder.” Marathon Oil Co. v. EPA , 564 F.2d 1253, 1272

- 73 (9 th Cir. 1977). But see, Weyerhaeuser Co. v. Costle , 590 F.2d 1011, 1057

- 58 (D.C. Cir. 1978) (holding that an informal approach is adequate). The affirmative defense provisions give the EPA the flexibility to both ensure that its emission limitations are “continuous” as required b y 42 U.S.C. § 7602(k), and account for unplanned upsets and thus support the reasonableness of the standard as a whole. Further, the EPA’s view is that the affirmative defense is not inconsistent with CAA section 113(e) or 304. Section 304 gives district court’s jurisdiction “to apply appropriate civil penalties.” Section 113(e)(1) identifies the factors that the Administrator or a court shall take into consideration in determining the amount of a penalty to be assessed, once it has been determined that a penalty is appropriate. The affirmative defense regulatory provision is not relevant to the amount of an y penalty to be assessed. If a court determines that the affirmative defense elements have been established, then a penalty is not appropriate and p enalty assessment pursuant to the section 113(e)(1) factors does not occur. In exercising its authority under section 112 to establish emission standards (at a level that meets the stringency

requirements of section 112), the EPA necessaril y defines co nduct that constitutes a violation. The EPA view is that the affirmative defense is part of the emission standard and defines two categories of violation. If there is a violation of the emission standard and the source demonstrates that all the elements of the affirmative defense are met, onl y injunctive relief is available. All other violations of the emission standard are subject to115

injunctive relief and penalties. The CAA does not require that all violations be treated equall y. Further, a citizen suit cl aim under section 304 allows citizens to commence a civil action against any person alleged to be in violation of “an emission standard or limitation under this chapter.” The CAA, however, allows the EPA to establish such “enforceable emission limitations. ” Thus, the citizen suit provision clearl y contemplates enforcement of the standards that are defined b y the EPA . As a result, where the EPA defines its emissions limitations and enforcement measures to allow a source the opportunity to prove its entitleme nt to a lesser degree of violation (not subject to penalties) in narrow, specified circumstances, as the EPA did here, penalties are not “appropriate” under section 304. The EPA’s view is that an affirmative defense to civil penalties for exceedances of applicable emission standards during periods of malfunction appropriately balances competing concerns. On the one hand, citizen enforcers are concerned about additional complications in their enforcement actions. On the other hand, industrial sources are c oncerned about being penalized for violations caused b y malfunctions that could not have prevented and were otherwise appropriatel y handled (as reflected in the affirmative defense criteria). The EPA has utilized its Section 301(a)(1) authority to issue re gulations necessary to carry out the Act in a manner that appropriately balances these competing concerns. The EPA disagrees that the affirmative defense provision will hamper citizen enforcement. First, injunctive relief is still available and the threat of penalties would not deter violations in cases where all of the conditions of the affirmative defense have been satisfied because the affirmative defense criteria ensure that all reasonable steps were taken to prevent a malfunction that causes excess emi ssions. Further, litigating whether a source has met the affirmative defense will not burden citizen group any more or less than would litigating the appropriate penalty amount in the penalty assessment stage of a citizen suit enforcement action, because the 113(e) penalty assessment criteria and the affirmative defense criteria are similar and in fact overlap. For example, the requirement that the Administrator or the court consider “good faith efforts to comply” is bound to generate the ty pe of fact

- inten sive disputes that the commenter complains of. In addition, several of the affirmative defense criteria are exactl y the ty pe of criteria the Administrator or Court might consider in determining whether a source made “good faith efforts to comply .” For example, to take advantage of the affirmative defense, the source must prove b y a preponderance of the evidence that, among other things, the excess emissions “were caused by an unavoidable failure of air pollution control and monitoring116

equipment, process equ ipment, or a process to operate in a normal or usual manner” and “could not have been prevented through careful planning, proper design or better operation and maintenance practices” and “did not stem from any activity or event that could have been foresee n and avoided, or planned for.” Thus, the EPA does not expect the affirmative defense provision to significantly alter the burden of bringing a citizen enforcement action. For those cases that do proceed to trial, even in the absence of this affirmative defense, sources generall y raise equitable arguments to argue for a low penalty

and citizens often rebut such arguments. Therefore, as a practical matter, the EPA does not expect the affirmative defense provision to materially affect the practice of CAA enforcement. Additionally , the affirmative de fense is reasonable. The EPA’s judgment is that the affirmative defense criteria capture the appropriate considerations in determining whether penalties are appropriate when a violation occurs as the result of a malfunction. As noted above, the affirmative defense criteria overlap to some extent with the penalty assessment criteria set forth in section 113(e), but are not identical. For example, size of business is one of the factors listed in section 113(e), but is not reflected in the EPA ’s affirmative de fense. This reflects the EPA ’s view that when a violation is caused by a malfunction, the size of the business is not relevant to whether penalties should be excused. If the violation was unavoidable and could not have been prevented, the EPA’s view is that it would be unfair to impose a penalty no matter the size of the business. The EPA is not adopting commenters’ suggestion with respect to compensatory damages or limits on the frequency of use of the affirmative defense. It is not clear that the EPA ha s authority to require the automatic imposition of compensatory damages and even if such authority exists, the EPA does not think automatic imposition of damages is appropriate. Ensuring that malfunctions do not recur can be handled through imposition of a ppropriate injunctive relief. In addition, the EPA’s view is that it would not be appropriate to limit a source’s ability

to take advantage of the affirmative defense to one time over a specified period of time such as ten ye ars given that the affirmative defense is onl y available when the source could not have prevented the excess emissions. With respect to commenters’ suggested reporting requirements, the reporting requirements in the rules promulgated today already require malfunction reporting and the a ffirmative defense provisions require that parties choosing to117

assert the affirmative defense meet additional malfunction reporting requirements. Any such reports submitted to the EPA are publicl y available pursuant to CAA section 114. **Comment :**  Commenter 111 stated that the affirmative defense provisions do not cure the EPA ’s failure to set emission standards that are achievable during SSM events and are not a substitute for setting emissions standards for these periods. The commenter further state that th e proposed standards with the affirmative defense do not represent emission limitations achieved by the best

- performing existing sources, nor do they meet the criteria for establishing beyond

the

- floor emission standards and that the affirmative defense is not a permissible substitute for setting standards for periods of malfunction and is insufficient to meet the EPA ’s obligations under CAA §112. Commenter 87 requests the EPA set aside the proposed affirmative defense for periods of malfunction and establ ish a work practice standard for these periods. **Response :**  The affirmative defense applies to malfunction events and not to periods of startup and shutdown. The affirmative defense is not intended as a substitute for standards under section 112

– the applic able standard applies during malfunctions, but a source may assert an affirmative defense in an enforcement action for penalties for emissions in excess of the standard. Elsewhere in this document , we address the commenter’s concern regarding whether the E PA has met its obligation under section 112 in addressing emissions during startup and shutdown. **Comment :**  Commenter 96 and 90 advised that the EPA should promulgate work practice standards for emissions during startups, shutdowns and malfunctions, rather than requiring compliance with the proposed emissions standards during these events. The EPA has not demonstrated that the best

- performing units can achieve the proposed MACT emission standards during SSM events. The commenter stated that “the unpredicta bility and variability of emissions during SSM events makes measuring their emissions infeasible using current measurement methods...” Commenter 90 suggested that the standards should require the development and implementation of an emissions minimization p lan that would be a dynamic document maintained at the facility
. **Response :**  Work practice standards have been included in the final rule for startup and shutdown periods where a facility will not be able to demonstrate compliance with the D/F and THC limit s based performance testing during these periods
. See section III.A.3 of the final rule preamble for a discussion of the se work practice standards and the impracticality of performance118

testing for THC and D/F during periods of startup and shutdown. No exemption for startup periods was requested or determined to be necessary for the lead emission standard
. **Comment :**  Commenter 90 provided additional support for incorporating work practic e standards for periods of SSM. According to the commenter: EPA claims that its approach to SSM is required by Sierra Club v. EPA , 551 F.3d 1019 (D.C. Cir. 2008), cert. denied, 2010 U.S. LEXI S 2265 (2010). In this decision, the D.C. Circuit vacated the exemption in 40 C.F.R. § 63.6(f)(1) and (h)(1) for SSM periods, and in light of this decision, EPA proposed emissions standards in the RTR Proposed Rule that apply at all times, including periods of SSM. 76 Fed. Reg. at 29,072. When setting standards in the earl y 1990’s under CAA § 112(d), EPA used its New Source Perform ance Standards (NSPS) program as a model. The § 112 standards were acknowledged b y EPA to be "essentially equivalent to [§ 111] performance standards" and that "unpredicted and reasonabl y unavoidable failures of air pollution control systems" would occur. 58 Fed. Reg. at 42,762, 42,777 (Aug. 11, 1993). To address this situation, EPA adopted an exemption similar to the one in the NSPS Program for SSM events and imposed a "general duty " to minimize emissions. Thus, EPA acknowledged, as earl y as 1993, that SSM events are not appropriate for inclusion in a MACT standard and that an alternative approach should be used to address these situations. While the D.C. Circuit in the Sierra Club vs. EPA case ruled that sources cannot be exempt from complying with MACT st andards, the court noted that Congress recognized in some instances that it may

not be feasible to prescribe or enforce an emission standard under § 112, and so § 112(h) "work practices" or "operational" standards are available in certain situations. See S ierra Club v. EPA , 551 F.3d at 1028. The D.C. Circuit also has recognized that standards based on what sources achieve must account for the limitations inherent in the technology used to reduce emissions. For example, in a case reviewing NSPS under § 111 of the CAA, Portland Cement Ass’n v. Ruckelshaus , 486 F.2d 375, 398 (D.C. Cir. 1973), the court acknowledged that " 'start

- up' and 'upset' conditions due to plant or emission device malfunction, is an inescapable aspect of industrial life and that allowanc e must be made for such factors in the standards that are promulgated." Id. Furthermore, in National Lime Ass’n v. EPA , 627 F.2d 416 (D.C. Cir. 1980), the court noted that "a uniform standard must be capable of being met under most adverse conditions which can reasonabl y be expected to recur." Id . at 431 n.46. The D.C. Circuit acknowledged this same principle almost 20 years later when reviewing emission standards for new sources in the medical waste incinerator rule under § 129 in Sierra Club v. EPA , 167 F .3d 658 (D.C. Cir. 1999). In that case, while the court did not find the record sufficient to support EPA’s approach for new sources, the D.C. Circuit did not object to a standard

- setting approach which would account for the performance of technology under the "worst reasonabl y foreseeable circumstances." See id. at 665. Furthermore, the D.C. Circuit reiterated the principle in National L ime that "where a statute requires that119

a standard be 'achievable,' it must be achievable 'under the most adverse circums tances which can reasonabl y be expected to recur.' " Id. at 665 (citing National L ime Ass’n v. EPA , 627 F.2d 416, 431 n.46 (D.C. Cir. 1980)). EPA has determined that CAA section 112 does not require that emissions that occur during periods of malfunction b e factored into development of CAA section 112 standards." 76 Fed. Reg. at 29,061. Considering that EPA’s proposed MACT standards are supposed to apply at all times, the implication is that periods of malfunction also are covered b y the MACT standards that appl y during normal operations. This approach directly conflicts with the statutory requirement that the MACT standard be "achievable." EPA has failed to recognize what Congress acknowledged in enacting §112: that it is likely that even best performers wi ll experience malfunctions. It is possible for pollution control equipment to fail in various way s. Power failures do occur, fabric filters fail, scrubber pumps fail even at best performers and despite the best efforts of companies to prevent and minimize such events. Industry can and does work to minimize such periods, but they do occur. Further, manufacturers of such equipment routinely make emission guarantees for normal operations and although they sometimes oversize equipment to account for some of the variability described above, it is very doubtful that vendors would provide sufficient numerical guarantees for equipment under such situations. Given that the MACT floor data does not consider malfunctions and that the statute requires that the MACT stan dard be "achievable," EPA should, if it is determined that it is appropriate to amend the MACT at all, set work practice requirements to address periods of malfunctions as well. **Response** : We have included work practice standards for periods of startup and shutdown for THC and D/F. With respect to standards for lead , EPA believes that the standards that otherwise appl y are also appropriate for startup and shutdown because the bag leak detection sy stems used to determine compliance with the emission standard for lead operates properl y during these periods. With respect to malfunctions, we do not find it appropriate to make a blanket determination that work practices should be applied for periods of malfunctions (which do not alway s cause situations that wi ll satisfy the criteria of section 112(h) regarding technical and economic practicality of measuring emissions ) . We have included an affirmative defense to civil penalties for malfunctions in the final rule that addresses situations that are beyond the control of the owner or operator , reflecting the caselaw in this area, as stated in response at pages 117
- 121 of this document
. **Comment** : Commenter 90 stated that the EPA ’s basis of cost for implementation of the affirmative defense is not supported, and in their estimate is significantly less than what would be expected. The EPA’s estimate of the number of occurrences per ye ar of 2

- 3 seems low as well.120

**Response :**  We beli eve that the cost estimate for implementation of the affirmative defense is reasonable. The commenter provided no specific data to support their claims. **3.8 Request for Comment Period Extension**  **Comment :**  Several commenters requested more time to review the p roposed package. Three commenters (70.1, 72, 73) requested a 60 day extension, one commenter ( 80 ) requested a 58 day extension, and one commenter ( 71) requested a 45 day extension
. Commente rs 70 , 71 , and 73 stated that the period for comments is insuffici ent to allow them to fully

review the proposed rule and docket materials, and develop meaningful comments to assist the Agen cy

in finali zing its proposal. Commenter 72 stated that the proposal raises a host of complicated issues that warrant careful consi deration in order to comment meaningfull y. Commenter 73 stated that an extension is warranted because not all documents on which the EPA relied in drafting the proposed rule were located in the docket on May 19. The commenter further noted that the comme nt period included Memorial Day and Independence Day , effectivel y shortening the time available to conduct the necessary anal ys es. Commenter 74 notes that the comment period for the EPA ’s proposed rule and that for the EPA ’s First External Review Draft Integrated Science Assessment for Lead share a common deadline. The commenter contends that it is not reasonable to review both of these lengthy documents on the same time frame. **Response :**  The EPA granted a 2 1 day extension of the comment period. The 21 day extension was the longest that the EPA could grant while still providing enough time to meet the court - ordered deadline for signature of this final rule. See also response at pages 127
- 127 below, explaining in more detail why further extensions were i nappropriate and unnecessary
. **3.9 Miscellaneous**  **Comment :**  Commenter 80 provided comment on the Draft Summary of Ambient L ead Monitoring Data near Secondary L ead Smelting Facilities document (EPA

- HQ
- 2011
- 0344
- 0041). The commenter stated that two of the monitoring sites listed for the Buick Resource Recycling Facility

are not ambient, but are located within the facility fenceline and should not appear in the table. The commenter also notes that the listed maximum 3

- month concentration of 2.46 μg/m 3 at site 2909 3016 in 2008 resulted from an upset condition at the facility, not typical operation.121

**Response :**  We have added footnotes to the applicable tables of the technical document clarifying the commenter’s points. **Comment :**  Commenter 78 and 83 stated that they support the proposed rule as published. **Response :**  We acknowledge the commenters’ support. **Comment :**  Industry

respondents ( 90 , 95 , 96 ) commented on the EPA ’s statement in the preamble to the proposed rule that “No new secondary lead smelte rs have been built in the last 20 years, and we anticipate no new secondary lead smelting facilities in the foreseeable future, although there is one facility currently in the process of expanding operations.” The commenter s note a secondary

lead smelting facility

that is currently

operating in Puerto Rico. Additionally , JCIis currentl y constructing a battery recycling facility in Florence, S.C. , and Exide Technologies holds an active Title V permit f or a facility

in Columbus, GA. The commenters contend that the EPA ’s failure to accuratel y and completely describe the industry

is grounds for withdrawal and re

- proposal of the rule. **Response :**  The commenters are correct in their statements regarding these facilities. However, we note that the JCIfacility in Florence, SC and the Exide facility in Columbus, GA are not operational. Therefore, ‘ emissions ’ (non

- existent) from these two facilities could not have affected an y revised emissions limits in the proposed rulemaking. With regards to the Puerto Rico facility , the EPA contacted The Battery Recycling Company requesting information in an effort to determine the potential impacts of the proposed rule on this facility
. The stack test data obtained by the EPA revealed that stack emissions of lead from this facility

are below the limit proposed by the EPA and therefore would not have affected the EPA’s stance that its proposed emissions limit for lead for this source category is technologicall y feasible and represents a level that is achieved in practice b y a well

- perform ing fabric filter . The data received can be found in docket ID: EPA
- HQ
- OAR
- 2011
- 0344
- 0124 and EPA
- HQ
- OAR
- 2011
- 0344
- 0125. With regards to total hydrocarbons and dioxins and furans from rotary

furnaces , EPA is not setting section 112 (d) standards in this ru le because of an absence of data to represent p erformance of rotary furnaces and is now preparing to send out section 114 information requests to obtain additional data. We have conducted anal ys es to evaluate the cost impacts of the proposed rule on the aforementioned facilities and have revised the technical document describing the cost impacts accordingl y. None of the data or information collected from these facilities alters the decisions made b y the EPA in this rulemaking. As such, we do not believe that this issue merits delay of this rulemaking.122

**Comment :**  Commenter 75 requested that the EPA issue a supplemental notice of rulemaking for the secondary lead smelting NESHAP. The commenter claims that there are “significant problems with the proposed rule that undermine EPA’s proposed MACT floors and its Ris k and Technology Review (RTR). ” First, the commenter notes that the proposed rule fails to consider emissions from The Battery Recycling Company ’s secondary lead smelter in Puerto Rico. The commenter notes that, with regards to risk, the EPA is required to consider emission from all members in the source category . The commenter further notes that the MACT floors proposed by the EPA for THC and D/F must be based on the best

- performing 5 sources and that the EPA ’s failure to consider emissions from the Puerto Rico facility prejudices these standards. Second, the commenter states that the p roposed rule is flawed because its risk review is based on a overestimation of dioxin emissions at the Exide Frisco facility . The commenter notes that Exide conducted a stack test in October 2010 demonstrating emissions 69 times lower than the estimate us ed b y the EPA in its risk assessment. Third, the commenter states that a supplemental notice of proposed rulemaking would allow the EPA to take into account additional stack testing data submitted by the industry
. **Response:** We do not believe that it is ap propriate to issue a supplemental notice of rulemaking for this source category
. We received data from the overwhelming majority of the industry in the ICR developed for the proposal. However, we did obtain data from the Battery Recycling Company

after th e proposal and the data did not change any of the substantive conclusions of the rulemaking. As noted in the final rule preamble, we have deferred standards for organic HAP and dioxin for rotary furnaces. We will collect data from the Battery Recycling Company and the JCIfacility currently under construction in South Carolina (if it is operational) and use those data to develop appropriate emission standards for those pollutants. The test data for dioxins and furans from the Exide Frisco facility mentioned by the commenter were not made available to the EPA until June of 2011, despite the testing being conducted in October 2010. The EPA requested these data from Exide repeatedly before the proposal and did not receive them. As noted by

the commenter, the data showed that the multipathway risks from dioxins and furans are below 1 in a million. However, the overestimated risk used in the proposal did not lead to an y emission standards for dioxins and furans being proposed under section 112(f). These data thus did not substantively change any

decisions made for this rulemaking making it unnecessary

to reopen the comment period . There were two additional stack tests mentioned by123

the commenter. First, the commenter mentioned that RSR’s Middletown, NY facility was performing additional testing on their rotary furnace for THC or dioxins and furans. However, the facility

provided additional test data for lead and confirmed that they did not perform additional testing for THC or dioxins and furans. The additional lead test data showed that the tested furnace was meeting the lead emission standard promulgated in this final rule. The second test cited by

the commenter occurred at the Exide Reading facility but was not provided to the EPA until late November 2011, too late to be incorporated into the MACT floor calculations (although, as noted, inclusion of those data might have made the standard slightly more stringent)
. The concerns presented by the commenter have been addres sed elsewhere in this document. **Comment :**  Comme nter s 86 , 92 , and 98 recommended that the EPA adopt a consolidated emissions reporting rule for HAPs. According to the commenters, “The lack of a federal requirement to collect the basic information on how many HAPs are released from stationary sources into the surrounding community is a serious imp ediment to any attempt to evaluate total HAP exposure and risk in a sound technical manner.” **Response :**  We agree and the EPA is currentl y considering how to collect such data. **Comment :**  Commenter 98 stated that the EPA should commit to review and update it s residual risk determination in this final rule at the same time as it is next required to review its § 112(d) technology

- based standard ( i.e., 8 years from promulgation of the final rule). **Response :**  This comment is beyond the scope of this rule. **Comment :**  Commenter 130 stated that the EPA finalized far less prescriptive design standards and work practices for the primary lead processing source category than it proposed for the secondary

lead smelting category . The commenter believes that the less prescriptive work practices and design standards should be applied to the secondary lead smelting rule. Specific proposed work practices that were proposed for secondary lead include the water application rate in pavement cleaning, the requirement to was h building roofs, and the requirement to conduct all maintenance activities within enclosures. The primary lead rule does not require these work practices. **Response :**  We have revised the list of required work practices to remove redundancy or potential w orkplace hazards based on a number of comments received on the proposed rule for the secondary

lead smelting source category . The specific water application rate for pavement cleaning, and the requirement to wash building roofs which EPA proposed are not i ncluded as124

requirement in the final rule . The proposed requirement to perform all maintenance activities within enclosures has been modified to ensure that maintenance activities that could generate lead dust are conducted in a manner that minimizes emiss ions of fugitive dust. However, the final list of work practice standards will ensure that fugitive dust is not generated outside of total enclosures, thereb y ensuring the public is protected with an ample margin of safety. **Comment :**  Commenter 130 discuss ed the requirement for total enclosures to be maintained at a negative pressure of at least 0.02 mm of Hg with an in

- draft velocity of 300 feet per minute with continuous multiple negative pressure monitoring units fitted with backup power supplies. The c ommenter compared the final primary lead standard to the proposed secondary lead standard. The primary lead standard is less prescriptive than the proposed secondary lead standard, and the commenter stated that there is no reason that the design standards for enclosures need to be more prescriptive. **Response :**  We believe that monitoring of building differential pressure is the most accurate means b y which to ensure that the enclosure building is under negative pressure at all times. This method provides direct measurements that the building is indeed maintained at negative pressure and thus not emitting contained material . Some commenters stated that specifying doorway

velocities could require substantial additional in

- draft, which could cause strain to b uilding structures, wind chill problems for workers, and pilot lights being extinguished. We agree with these comments and have therefore removed the proposed requirement to measure in

- draft velocity at the openings of the total enclosures , but have retain ed the continuous differential pressure monitoring requirement. However, we have altered the differential pressure requirement from 0.02 mm of mercury to 0.013 mm of mercury to be consistent with the EPA Method 204’s criteria for verification of a permanent or temporary total enclosure. Because fugitive lead emissions are the predominant contributor to overall risk for the secondary lead source category , EPA concluded that total enclosures with continuous monitoring of negative pressure were appropriate for this category
. **Comment :**  Commenter 130 compared the bag leak detection s ys tem requirement in the proposed secondary

lead rule to the requirement in the final primary lead rule. The EPA proposed to remove the 1997 NESHAP exemption in the secondary lead rule for bag leak detection sy stem on baghouses fitted with secondary HEPA filtration. In the final primary lead rule, EPA included this exemption.125

**Response** : We agree with the commenters that baghouses equipped with HEPA filters do not need bag leak detection sy stems as well. Measurement of pressure drop across a HEPA filter provides the needed information to determine that the filter is performing effectivel y so a bag leak detection sy stem would be redundant
. **Comment** : Commenter 130 noted that a comme nt by the ABR was included in the primary lead rule docket opposing the proposed requirement that new primary lead processing facilities install and operate continuous emission monitoring sy stems for lead. The comment also explained why

the EPA should not include a similar requirement in the secondary lead smelting rule. The ABR comment to the primary lead proposed rule stated that without setting a performance specification at the time of proposal, there is no way for the commenter to meaningfully

assess the sy stem and the potential applicability . There is no assurance that the CEM technology

will be sufficiently

sensitive and robust to provide reliable data on emissions for secondary

lead smelter stacks. Additionall y the requirement to install a CEMS w ould impose a cost burden that would be greater than any incremental environmental benefit. **Response** : We have considered the cost estimates provided b y all commenters and maintain that it is appropriate to include the requirement for lead CEMS for new sources. However, a performance specification for lead CEMS will be promulgated prior to the requirement b ecoming effective in this subpart. The process for promulgating a lead CEMS method includes proposing such a method and providing the opportunity for public comment. In addition, EPA would consider as part of the rulemaking proceeding, whether it is appropriate to adjust the level of an y standard measured b y a CEM considering the more frequent measurement and hence dampening of variability over time of multiple measurements. **Comment** : Commenter 127 submitted late comments in response to late

- filed additiona l comments from the Pall Corporation. The commenter is concerned that EPA is not providing a complete record of supporting materials in the docket, in that minutes of a meeting between EPA and Pall in September 2011 are not docketed. The commenter noted that the comments provided by Pall do not include any

explanation as to why

the information was not submitted before the end of the comment period. The commenter does not believe there is sufficient information in the EPA’s proposal and supporting documentation regarding the feasibility , performance specifications or quality

assurance procedures of a Pb CEMS. The cost noted by the Pall Corporation in the late

- filed comments is incomplete and misleading in that it does not include all installation costs.126

**Response** : While the commenter is correct that the additional comments submitted by the Pall Corporation were received after the close of the public comment period, that does not bar the EPA from considering those comments, just as it did not bar the EPA from considering the multiple comments submitted by ABR after the close of the public comment period. The additional comments submitted by the Pall Corporation essentially emphasized their request that the agency

respond to their original comments rather th an raising new issues (with the exception of new cost information). The updated cost information provided by the Pall Corporation did include caveats that certain costs were excluded, as mentioned by the commenter. The EPA has considered both the cost esti mate provided b y the commenter and b y Pall Corporation. The costs submitted by

the commenter ($400,000 per device) were the values that the EPA used to determine whether it was appropriate to require these devices for new sources. We deemed that it was app ropriate. Whether the costs remain at $400,000 or are indeed lower, we maintain that it is an appropriate requirement. With regard to comments on the feasibility of a Pb CEMS, the EPA has included the requirement for new sources to install a CEMS only afte r the performance specifications for a lead CEMS method have been promulgated. The EPA will conduct an investigation into the feasibility and cost effectiveness of a Pb CEMS before as a part of the rulemaking process for the performance specification. That rulemaking will involve a public comment period during which the commenter may inform the EPA of any

potential problems with the performance specification that is proposed. The total cost of installing and operating a CEMS will be considered in the evaluation. Notes from the September 2011 between the EPA and Pall Corporation were posted in the docket well before the signature date of the final rule, see EPA
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