&EPA
United Stabs
Environmental Protection
Agency
STANDARDS OF PERFORMANCE FOR NEW STATIONARY
SOURCES AND EMISSION GUIDELINES FOR EXISTING
SOURCES: SEWAGE SLUDGE INCINERATION UNITS
SUMMARY OF PUBLIC COMMENTS AND RESPONSES
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Emission Standards Division
Research Triangle Park, North Carolina 27711
February 2011
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The primary contact regarding questions or comments on this document is:
Amy Hambrick (919) 541-0964
U.S. Environmental Protection Agency
OAQPS/Sector Policies and Programs Division
Natural Resources and Commerce Group (El43-03)
Research Triangle Park, North Carolina 27711
Email: hambrick.amy@epa.gov
11
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TABLE OF CONTENTS
Section Page No.
1.0 INTRODUCTION 1-1
2.0 LIST OF COMMENTERS 2-1
3.0 APPLICABILITY OF THE STANDARDS AND EMISSION GUIDELINES 3-1
3.1 Exemptions 3-1
3.2 Definition of Modification 3-5
3.3 Applicability Dates 3-8
3.4 Definition of Solid Waste 3-9
3.5 Other 3-14
4.0 EMISSION LIMITS AND GUIDELINES 4-1
4.1 Metals 4-1
4.2 PM 4-3
4.3 CO 4-4
4.4 CDD/CDF 4-6
4.5 Opacity 4-6
4.6 Exhaust Gas Concentration 4-8
4.7 Other 4-8
5.0 FORMAT OF THE PROPOSED STANDARDS AND GUIDELINES 5-1
6.0 SELECTION OF SUBCATEGORIES 6-1
7.0 TITLE V PERMIT REQUIREMENTS 7-1
8.0 BASELINE EMISSIONS ESTIMATES 8-1
8.1 Baseline Emissions Overstated 8-1
8.2 Comments on CO baseline emissions 8-4
8.3 Uncontrolled Emissions are Incorrect 8-5
8.4 Metals Content of Sludge 8-6
8.5 EPA Missing Data 8-6
9.0 FACILITY/UNIT SPECIFIC INFORMATION AND DATA CORRECTIONS 9-1
9.1 General Facility Information 9-1
9.2 Heat Recovery and SSI Units 9-2
9.3 Incineration for Other WWTP 9-2
10.0 MACT FLOOR DETERMINATION METHODOLOGY 10-1
10.1 Feed Operational Variability has not been taken into Account 10-1
10.2 Criticism's of EPA's Select! on of Facilities for the MACT Floor 10-4
in
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10.3 Pollutant by Pollutant Approach is Unreasonable 10-7
10.4 Criticisms of the Statistical Method 10-9
10.5 Treatment of Non-Detect Data 10-13
10.6 Comments on NOX Limits 10-16
10.7 Comments on the HCI Standards 10-18
10.8 Comments on Mercury Limits 10-18
11.0 BEYOND THE FLOOR ALTERNATIVES 11-20
11.1 BTF for Mercury 11-20
11.2 Over/Understated Mercury Emissions/Costs 11-21
11.3 Alternative Mercury Control Options 11-23
11.4 Opposition to ACT 11-26
11.5 CO 100 ppmv Limit 11-32
11.6 CO Control 11-33
11.7 BTF for Other Pollutants 11-35
12.0 PERFORMANCE TESTING AND MONITORING REQUIREMENTS 12-1
12.1 Operating Ranges 12-1
12.2 Data Averaging Periods 12-6
12.3 Testing Frequency 12-9
12.4 Definition of "Process Change" 12-11
12.5 Waste Management Plan 12-13
12.6 Annual Visible Emissions Test 12-14
12.7 Daily CPMS Pressure Tap Checks 12-17
12.8 Cleaning and Calibrating 12-17
12.9 Alternative Initial Accuracy Determination Procedure 12-19
12.10 Sludge Content Monitoring as Alternative to Stack Test 12-20
12.11 Other Performance Testing and Monitoring Concerns 12-21
13.0 RECORDKEEPING AND REPORTING REQUIREMENTS 13-1
14.0 OPERATOR TRAINING AND QUALIFICATION REQUIREMENTS 14-1
15.0 STARTUP, SHUTDOWN, MALFUNCTION 15-1
15.1 Emission Limitations at All Times 15-1
15.2 Application of Sierra Club Decision to 111/129 15-8
15.3 Different/Alternate Standards for SSM 15-10
15.4 MACT Floor Analysis as it Applies to SSM 15-13
iv
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15.5 Format of Affirmative Defense 15-18
15.6 Startup and Shutdown in Affirmative Defense 15-26
15.7 Application of Affirmative Defense 15-27
15.8 Operating Modes 15-34
16.0 DELEGATION OF AUTHORITY 16-1
17.0 STATE PLANS 17-1
18.0 IMPACTS ANALYSIS (EXCLUDING SMALL BUSINESS AND LANDFILLLING
IMPACTS) 18-1
18.1 Total Cost is Incorrect 18-1
18.2 Compliance Assumptions are not Representative of Current Facilities 18-2
18.3 Cost per Pound of Pollutant is Too Low 18-3
18.4 Assumed Level of Control for Metals is Too High 18-5
18.5 Required Controls and Associated Costs are Inaccurate 18-6
18.6 Actual Costs to Upgrade are Too High 18-10
18.7 Costs of Activated Carbon Injection are Inaccurate 18-13
18.8 Additional NOX Controls 18-17
18.9 Additional Heavy Metal Controls 18-19
18.10 Additional SO2 Controls 18-20
18.11 Unfair Impacts for Existing FluidizedBed Incinerators 18-20
18.12 Regulation Forces Incinerator Closures 18-21
18.13 Space Constraints 18-24
18.14 Additional Cost Concerns 18-25
18.15 Greenhouse Gases and Fossil Fuel Use Would Increase 18-26
18.16 Environmental Benefits of Incineration 18-27
18.17 Energy Recovery Would be Reduced 18-29
18.18 Other 18-30
19.0 IMPACTS ANALYSIS-SMALL BUSINESS 19-1
20.0 IMPACTS ANALYSIS-LANDFILLING COSTS 20-1
20.1 Landfill Disposal Cost Basis 20-1
20.2 Landfill Availability Concerns 20-4
20.3 Odor Concerns 20-7
20.4 State Land Filling Regulation Concerns 20-8
20.5 Additional Expenditures and Site Constraints 20-10
20.6 Greenhouse Gas Emissions and Environmental Concerns 20-12
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20.7 Other 20-16
21.0 RELATIONSHIP TO CAA SECTIONS 112(C)(3) AND 112(K)(3)(B)(II) (AREA
SOURCES) 21-1
22.0 RELATIONSHIP TO OTHER SSI RULES FOR THE USE OR DISPOSAL OF
SEWAGE SLUDGE 22-1
23.0 STATUTORY AND EXECUTIVE ORDER REVIEWS 23-1
24.0 DURATION OF COMMENT PERIOD 24-1
25.0 ELECTRONIC DATA SUBMITTAL 25-1
26.0 STATUTORY BASIS FOR REGULATING SSIS UNDER SECTION 129 (E.G., VS.
Ill) 26-1
27.0 SOURCE REDUCTION (I.E., THE STRATEGY OF REDUCING EMISSIONS AT
THE UPSTREAM SOURCE) 27-1
VI
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1.0 INTRODUCTION
On October 14, 2010, EPA proposed New Source Performance Standards for new units
(NSPS) and Emission Guidelines for existing units (EG) for sewage sludge incineration units.
This document contains summaries of the public comments that EPA received on the proposed
standards. In this document, EPA responds to the public comments. The public comments and
EPA responses document the basis for revisions made between the proposal on October 14,
2010, and the subsequent final rules. Copies of all comments submitted are available at the EPA
docket Center Public Reading Room. Comment letters and transcripts of the public hearings are
also available electronically through http://www.regulations.gov by searching Docket ID
EPA-HO-OAR-2009-0559.
1-1
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2.0 LIST OF COMMENTERS
The EPA received 90 comment letters on the proposed Standards of Performance for
New Stationary Sources (NSPS) and Emission Guidelines for Existing Sources (EG): sewage
sludge incineration units, before the comment period closed on November 29, 2010. Comments
from a public hearing held on November 15 are also included in this document. All comments
are contained in Docket EPA-HQ-OAR-2009-0559. The commenter, affiliation, and item
number in Docket EPA-HQ-OAR-2009-0559 is listed in Table 1. A list of acronyms and units of
measure used in this document appears after the list of commenters.
Table 2-1. Public Comments Received by November 29, 2011 for Standards of Performance
for New Stationary Sources and Emission Guidelines for Existing Sources: Sewage Sludge
Incineration Units, Proposed Rule Docket EPA EPA-HQ-OAR-2009-0559
Commenter Identification Code
EPA-HQ-OAR-2009-0559-0048. 1
EPA-HQ-OAR-2009-0559-0049. 1
EPA-HQ-OAR-2009-0559-005 1 . 1
EPA-HQ-OAR-2009-0559-0052. 1
EPA-HQ-OAR-2009-0559-0053.1
EPA-HQ-OAR-2009-0559-0054. 1
EPA-HQ-OAR-2009-0559-0055
EPA-HQ-OAR-2009-0559-0056. 1
EPA-HQ-OAR-2009-0559-0057
EPA-HQ-OAR-2009-0559-0058. 1
EPA-HQ-OAR-2009-0559-0059. 1
EPA-HQ-OAR-2009-0559-0060. 1
EPA-HQ-OAR-2009-0559-0061.1
EPA-HQ-OAR-2009-0559-0062. 1
Commenter and Affiliation
Bob Bandarra, Department of Public Works, City of
Bellingham, Washington
S. Greenwood
David J. Shaw, Director, Air Resources Division, New York
State Department of Environmental Conservation (NYSDEC)
Rich Raiders, Environment and Sustainable Development
Department, Arkema Inc.
Ashok K. Jain, Southern Regional Manager, National Council
for Air and Stream Improvement, Inc. (NCASI)
John A. Cooper, Ph.D., President, Aaron C. Siemers,
Environmental Specialist, and Andrea L. Geiger,
Environmental Specialist; Cooper Environmental Services,
LLC (CES)
Robert R. Scott, Director, Air Resources Division, State of
New Hampshire Department of Environmental Services
(NHDES)
Stanley J. Chilson, Senior Project Manager, GET Engineering
Services
Darryl Sanderson, The Dow Chemical Company
Robert Androsiglio, Division Superintendent, Township of
Wayne, N.J. Mountain View Water Pollution Control Division
(WPCF)
Darryl Sanderson, EH&S Global Regulatory Affairs, The Dow
Chemical Company
John A. Cooper, President, Cooper Environmental Services
LLC (CES)
Mark Premo, General Manager, Anchorage Water and
Wastewater Utility (AWWU)
Robert Androsiglio, Division Superintendent, Water Pollution
Control Division, Township of Wayne, New Jersey
2-1
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Commenter Identification Code
EPA-HQ-OAR-2009-0559-0063.1
EPA-HQ-OAR-2009-0559-0064. 1
EPA-HQ-OAR-2009-0559-0065.1
EPA-HQ-OAR-2009-0559-0066. 1
EPA-HQ-OAR-2009-0559-0067. 1
EPA-HQ-OAR-2009-0559-0068. 1
EPA-HQ-OAR-2009-0559-0069. 1
EPA-HQ-OAR-2009-0559-0070. 1
EPA-HQ-OAR-2009-0559-0071.1
EPA-HQ-OAR-2009-0559-0072. 1
EPA-HQ-OAR-2009-0559-0073.1
EPA-HQ-OAR-2009-0559-0074. 1
EPA-HQ-OAR-2009-0559-0075.1
EPA-HQ-OAR-2009-0559-0076. 1
EPA-HQ-OAR-2009-0559-0076.2
EPA-HQ-OAR-2009-0559-0077. 1
EPA-HQ-OAR-2009-0559-0078. 1
EPA-HQ-OAR-2009-0559-0079. 1
EPA-HQ-OAR-2009-0559-0080. 1
EPA-HQ-OAR-2009-0559-008 1 . 1
EPA-HQ-OAR-2009-0559-0082. 1
Commenter and Affiliation
Jerry N. Johnson, General Manager and CEO, Washington
Suburban Sanitary Commission(WSSC)
Nancy Wittenberg, Assistant Commissioner, Climate and
Environmental Management, New Jersey Department of
Environmental Protection (NJDEP)
Louis T. Barry, President, Chavond-Barry Engineering
Corporation (CBE)
Stephen R. Gossett, Senior Environmental Associate, Eastman
Chemical Company
Brian W. Arnet, Executive Director, Mattabassett District
Water Pollution Control Facility (WPCF), Mattabassett District
Regional Sewer Authority, Connecticut
Thomas K. Walsh, Engineer Director and Treasurer, Upper
Blackstone Water Pollution Abatement District (UBWPAD)
Jim Larkin, Director, Unified Government of Wyandotte
County/Kansas City, KS, (UG)
Howard Hurwitz, Executive Director, Northwest Bergen
County Utilities Authority (NBCUA)
Mark A. Haley, Director, Hopewell Regional Wastewater
Treatment Facility (HRTWTF) Commission, Hopewell
Regional Wastewater Treatment Facility (HRTWTF), City of
Hopewell, Virginia
John D. Reece, Executive Director, Little Blue Valley Sewer
District (LBVSD)
Layne Baroldi, Regional Vice President of Project
Development, Synagro Technologies, Inc.
Robert Patten, Assistant Director, Water Pollution Control,
City of Independence, Missouri
Arthur M. Tamilia, Esq., Director of Environmental
Compliance, Allegheny County Sanitary Authority
(ALCOSAN), Pittsburgh, Pennsylvania
Margaret P. Orr for James M. Kelly, P.E., General Manager,
Central Contra Costa Sanitary District (CCCSD), Martinez,
California
Margaret P. Orr for James M. Kelly, P.E., General Manager,
Central Contra Costa Sanitary District (CCCSD), Martinez,
California
Alan B.Rubin, Ph.D., Envirostrategies, LLC
James Sizemore, Manager, Regulatory Compliance, Alexandria
Sanitation Authority (ASA)
G. Vinson Hellwig and Robert H. Colby, Co-Chairs, Air
Toxics Committee, National Association of Clean Air
Agencies (NACAA)
Kathleen A. Luvisi, Project Engineer, Alternative Resources,
Inc. on behalf of Borough of Naugatuck, Connecticut
Robert W. Bush, P.E., Senior Director, Department of
Watershed Management, City of Atlanta, Georgia
Ronald Poltak, Executive Director, New England Interstate
Water Pollution Control Commission (NEIWPCC)
2-2
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Commenter Identification Code
EPA-HQ-OAR-2009-0559-0083.1
EPA-HQ-OAR-2009-0559-0084. 1
EPA-HQ-OAR-2009-0559-0085.1
EPA-HQ-OAR-2009-0559-0086. 1
EPA-HQ-OAR-2009-0559-0086.2
EPA-HQ-OAR-2009-0559-0087. 1
EPA-HQ-OAR-2009-0559-0088. 1
EPA-HQ-OAR-2009-0559-0089. 1
EPA-HQ-OAR-2009-0559-0090. 1
EPA-HQ-OAR-2009-0559-0091.1
EPA-HQ-OAR-2009-0559-0092. 1
EPA-HQ-OAR-2009-0559-0093.1
EPA-HQ-OAR-2009-0559-0094. 1
EPA-HQ-OAR-2009-0559-0095.1
EPA-HQ-OAR-2009-0559-0095.2
EPA-HQ-OAR-2009-0559-0096. 1
EPA-HQ-OAR-2009-0559-0097. 1
EPA-HQ-OAR-2009-0559-0098. 1
EPA-HQ-OAR-2009-0559-0099. 1
EPA-HQ-OAR-2009-0559-0100.1
EPA-HQ-OAR-2009-0559-0101.1
EPA-HQ-OAR-2009-05 5 9-0 1 02 . 1
EPA-HQ-OAR-2009-0559-0103.1
EPA-HQ-OAR-2009-05 5 9-0 1 04 . 1
Commenter and Affiliation
Lisa Ochsenhirt, Attorney, AquaLaw on behalf of the
Maryland Association of Municipal Wastewater Agencies, Inc.
etal.
Earthjustice, Sierra Club, Friends of the Earth
James S. Allen, Manager, Water Quality Control Plant and Phil
Bobel, Manager, Environmental Compliance, Public Works
Department, City of Palo Alto, California
Ted Michaels, President, Energy Recovery Council (ERC)
Ted Michaels, President, Energy Recovery Council (ERC)
Tatyana Arsh, Director, Department of Public Utilities (DPU),
City of Columbus, Ohio
Gregory M. Adams, Assistant Departmental Engineer, Air
Quality Engineering, Technical Services Department, Los
Angeles County Sanitation Districts
Steven A. Hann, Hamburg, Rubin, Mullin, Maxwell & Lupin,
P.C. on behalf of Hatfield Township Municipal Authority
Dr. James J. Pletl, Technical Services Division, Hampton
Roads Sanitation District (HRSD)
Russell Frye, SSM Coalition
Alice Edwards, Acting Director, Air Quality Division, Alaska
Department of Environmental Conservation (ADEC)
Brian K. Carlson, Director of Public Works, City of
Vancouver, WA
Robert C. Fischer, Executive Director, Bayshore Regional
Sewerage Authority (BRSA)
Melvin E. Keener, Ph.D., Executive Director, Coalition for
Responsible Waste Incineration (CRWI)
Melvin E. Keener, Ph.D., Executive Director, Coalition for
Responsible Waste Incineration (CRWI)
Jeffrey Theerman, P.E., Executive Director, Metropolitan St.
Louis Sewer District (MSD), Missouri
Ken Kirk, Executive Director, National Association of Clean
Water Agencies (NACWA) Attachments C and D.
Ken Kirk, Executive Director, National Association of Clean
Water Agencies (NACWA) Attachment A
Ken Kirk, Executive Director, National Association of Clean
Water Agencies (NACWA) Attachment B
Lorraine Krupa Gershman, Director, American Chemistry
Council (ACC)
Karl E. Monninger, Vice President, Chavond-Barry
Engineering Corp. (CBE) on behalf of Thomas Lauletta, Vice
President, Wastewater Division, Atlantic County Utilities
Authority
John Kiviniemi, Director, Water Reclamation, Metropolitan
Sewerage District of Buncombe County, North Carolina
William G. Moore, General Manager, Metropolitan Council
Environmental Services (MCES)
Alice Edwards, Acting Director, Division of Air Quality,
Alaska Department of Environmental Conservation (ADEC)
2-3
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Commenter Identification Code
EPA-HQ-OAR-2009-0559-0105.1
EPA-HQ-OAR-2009-0559-0106.1
EPA-HQ-OAR-2009-0559-0107.1
EPA-HQ-OAR-2009-0559-0108.1
EPA-HQ-OAR-2009-0559-0109.1
EPA-HQ-OAR-2009-0559-0110.1
EPA-HQ-OAR-2009-0559-01 1 1 . 1
EPA-HQ-OAR-2009-0559-0 112.1
EPA-HQ-OAR-2009-0559-01 13.1
EPA-HQ-OAR-2009-0559-0 114.1
EPA-HQ-OAR-2009-0559-01 15.1
EPA-HQ-OAR-2009-0559-01 16.1
EPA-HQ-OAR-2009-0559-01 17.1
EPA-HQ-OAR-2009-0559-01 18.1
EPA-HQ-OAR-2009-0559-01 19.1
EPA-HQ-OAR-2009-0559-0 120.1
EPA-HQ-OAR-2009-0559-0 12 1.1
EPA-HQ-OAR-2009-05 5 9-0 1 22
EPA-HQ-OAR-2009-0559-0 123
EPA-HQ-OAR-2009-05 5 9-0 1 24 . 1
EPA-HQ-OAR-2009-0559-0 125
EPA-HQ-OAR-2009-0559-0 126.1
EPA-HQ-OAR-2009-0559-0 127.1
EPA-HQ-OAR-2009-0559-0 127.2
EPA-HQ-OAR-2009-0559-0 127.3
Commenter and Affiliation
Sally Keating, Manager, Environment Health and Safety, The
Metropolitan District (MDC)
James A. Parrott, Executive Director, Metorpolitan Sewer
District of Greater Cincinnati (MSDGC)
John Franz, Manager, Wastewater Treatment Plant, City of
Anacortes, Washington
Caroline Quinn, P.E., Project Manager, Delta Diablo Sanitation
Districton behalf of Bay Area Biosolids to Energy Project
David R. Sherman, Director, City of Indianapolis, Department
of Public Works
Greg Kester, Biosolids Program Manager, California
Association of Sanitation Agencies (CASA)
Steve Koho, Plant Manager, City of Edmonds, WA
Tatyana Arsh, Director, City of Columbus, Ohio, Department
of Public Utilities (DPU)
Randolph W. Bartlett, Director Stormwater and Wastewater
Management, Fairfax County Wastewater Treatment Division
(FCWTD)
Gary Zrelak, Director of Operations, Greater New Haven
Water Pollution Control Authority (GNHWPCA)
Stephen L. Hershner, Utilities Environmental Manager, Cedar
Rapids Water Pollution Control Facilities (CRWPCF)
Donald B. Howard, Water Reclamation Manager, Department
of Water Resources, City of Greensboro, North Carolina
John C. Ewell III, P.E., Treatment Plant Supervisor, Public
Works Department, City of Lynwood, Washington
Joseph L. Salvucci, Executive Director, Delaware County
Regional Water Quality Control Authority (DELCORA)
Earthjustice, Sierra Club, and Friends of the Earth
Thomas W. Sigmund, Executive Director, Green Bay
Metropolitan Sewerage District (GBMSD)
Michael J. Quinn, Deputy Commissioner, Erie County Division
of Sewerage Management (ECDSM)
Peter Dorney, Executive Director, Hatfield Township
Municipal Authority
Timothy A. Boyd, Executive Director, East Norriton Plymouth
Whitpain Joint Sewer Authority (JSA)
Douglas L. McVay, Acting Chief, Office of Air Resources,
Rhode Island Department of Environmental Management
(RIDEM)
Jim Sullivan, Principal, Biosoils
Susan M. Whittaker, Maraziti, Falcon & Healey, LLP on behalf
of John Kantorek, Executive Director, Stony Brook Regional
Sewerage Authority (SBRSA)
Chris Hornback, Senior Director, Regulatory Affairs, National
Association of Clean Water Agencies (NACWA)
Chris Hornback, Senior Director, Regulatory Affairs, National
Association of Clean Water Agencies (NACWA)
Chris Hornback, Senior Director, Regulatory Affairs, National
Association of Clean Water Agencies (NACWA)
2-4
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Commenter Identification Code
EPA-HQ-OAR-2009-0559-0128.1
EPA-HQ-OAR-2009-0559-0 129.1
EPA-HQ-OAR-2009-0559-0130.1
EPA-HQ-OAR-2009-0559-0 13 1 . 1
EPA-HQ-OAR-2009-0559-0132.1
EPA-HQ-OAR-2009-0559-0133.1
EPA-HQ-OAR-2009-0559-0134.1
EPA-HQ-OAR-2009-0559-0135.1
EPA-HQ-OAR-2009-0559-0136.1
EPA-HQ-OAR-2009-0559-0137.1
EPA-HQ-OAR-2009-0559-0137.2
EPA-HQ-OAR-2009-0559-0137.3
EPA-HQ-OAR-2009-0559-0137.4
EPA-HQ-OAR-2009-0559-0138
EPA-HQ-OAR-2009-0559-0138.3
EPA-HQ-OAR-2009-0559-0138.4
EPA-HQ-OAR-2009-0559-0138.5
EPA-HQ-OAR-2009-0559-0138.6
EPA-HQ-OAR-2009-0559-0138.7
EPA-HQ-OAR-2009-0559-0138. 8
EPA-HQ-OAR-2009-05 5 9-0 1 44
EPA-HQ-OAR-2009-0559-0 145.1
Commenter and Affiliation
John Kivinlemi, Chair, North Carolina American Water Works
Association (NCAWWA) and North Carolina Water
Environment Association (NCWEA)
Julius Ciaccia, Executive Director, Northeast Ohio Regional
Sewer District (NEORSD)
Bill Thompson, National Tribal Air Association Executive
Committee Chairperson and Tribal Vice-Chief, Penobscot
Nation, National Tribal Air Association (NTAA)
Glenn B. Harvey, Prince William County Service Authority
(PWSCA)
Larry R. Thomas, Executive Director, Ypsilanti Community
Utilities Authority (YCUA)
Dick Munson, Senior Vice President, Recycled Energy
Development (RED)
Tim Williams, Senior Managing Director, Public Policy, Water
Environment Federation (WEF)
Glenn T. Almquist, Senior Vice President, Woodard & Curran
Barry G. Parks, Assistant Director of Public Services / Water
Resources, City of Wilson, North Carolina
Melissa Hamkins, Senior Project Manager, Wright-Pierce
Melissa Hamkins, Senior Project Manager, Wright-Pierce
Melissa Hamkins, Senior Project Manager, Wright-Pierce
Melissa Hamkins, Senior Project Manager, Wright-Pierce
United States Environmental Protection Agency Public
Hearing 40 CFR Part 60 Standards of Performance for New
Stationary Sources and Emission Guidelines for Existing
Sources: Sewage Sludge Incineration Units; Proposed Rule
USEPA Public Hearing 129 Sanitary Sewer Incinerator Rule
City of Greensboro - USEPA Public Hearing
Public Hearing on Proposed Standards of Performance for New
Stationary Sources and Emission Guidelines for Existing
Sources: Sewage Sludge Incineration Units (Testimony of
Robert P. Dominak)
Standards of Performance for New Stationary Sources and
Emission Guidelines for Existing Sources: Sewage Sludge
Incineration Units (SSIs)
Public Hearing on Proposed Standards of Performance for New
Stationary Sources and Emission Guidelines for Existing
Sources: Sewage Sludge Incineration Units
John Sprague, Director of Operations, Metropolitan St. Louis
District, USEPA Public Hearing
Georgia Department of Natural Resources
Carlson Associates Technical Services INC
2-5
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List of Acronyms and Abbreviations
Acronyms
ACC American Chemistry Council
AN Acrylonitrile
ANPRM Advanced Notice of Proposed Rulemaking
ATSDR Agency for Toxic Substances and Disease Registry
CAA Clean Air Act
CMPUs SOCMI chemical manufacturing process units
EPA U. S. Environmental Protection Agency
FR Federal Register
GACT generally available control technology
HAP hazardous air pollutants
HI Hazard Index
HON hazardous organic NESHAP
HQ hazard quotient
IDLH/10 imminently dangerous to life and health
IRIS Integrated Risk Information System
LDAR detection and repair
MACT maximum achievable control technology
MON Miscellaneous organic NESHAP
NEI National Emissions Inventory
NESHAP national emission standards for hazardous air pollutants
NSR new source review
NTP National Toxicology Program
OLD Organic Liquid Distribution
ppmv parts per million by volume
RCRA Resource Conservation and Recovery Act
RFC reference concentration
SIC Standard Industrial Classification
SOCMI Synthetic Organic Chemical Manufacturing Industry
SSMP startup, shutdown, and malfunction plan
TERA Toxicology Excellence for Risk Assessment
VOC volatile organic compounds
2-6
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3.0 APPLICABILITY OF THE STANDARDS AND EMISSION
GUIDELINES
3.1 Exemptions
Comment: Several commenters (51.1, 86.1, 110.1, 129.1) were concerned that other
solid waste incineration unit designs could be considered SSI units and subject to the proposed
sewage sludge incineration standards if they combust any amount of sewage sludge. One
commenter (86.1) stated that the definition of an SSI unit in the proposed sewage sludge
incineration standards does not explicitly limit units to only FB and MH SSI unit designs, nor
does the definition require a minimum amount of sewage sludge be combusted to be considered
a SSI unit. One commenter (51.1) expressed concern about how municipally owned SSI units
combusting both sewage sludge and non-sludge commercial industrial wastes, which is typically
not treated, would be regulated. The commenter (51.1) asked whether such a facility would be
subject to both the proposed SSI requirements and the CISWI requirements. Two commenters
(86.1, 92.1, 104.1) stated that EPA should exempt co-fired combustors from the proposed
sewage sludge incineration standards. The commenters (86.1, 92.1, 104.1) mentioned that the
term "co-fired combustor" is defined, but is never used anywhere in the proposed sewage sludge
incineration standards (except in the definition sections).
Other commenters (86.1) suggested that an upper limit be placed on the amount of
sewage sludge that could be co-fired and still meet the exemption. One commenter (110.1)
suggested EPA include a de minimi s limit on the mass of sewage sludge combusted in a unit
before being covered by the proposed sewage sludge incineration standards. At least one
commenter (92.1, 104.1) specifically requested that small co-fired combustors with charge rates
under 1000 kg/day be explicitly exempted from the proposed sewage sludge incineration
standards. The commenter (92.1, 104.1) emphasized remote mining camps in Alaska could face
significant financial and logistical hardships to dispose of their waste; these camps use co-fired
incinerators to dispose of 10 percent or less sewage sludge with charging rates under 1000
kg/day, and do not have alternative sludge disposal options. The commenter (92.1, 104.1) added
these sources are exempt from 40 CFR 60 Subpart O.
Two commenters (86.1, 129.1) suggested the exemption be units firing 30% or less by
weight, which is consistent with the co-fired combustor definition contained in MWC Section
129 rules. One of these commenters (86.1) contended that because sewage sludge has a high
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moisture content and its heating value is low, a 10% limit by weight would effectively limit
firing to a much lower fraction of total heat input, providing little incentive for operators to make
any physical and permitting modifications necessary to accept sewage sludge. One commenter
(90.1) specifically responded to EPA's solicitation for comments on whether sewage sludge that
is incinerated in combustion units located at commercial and industrial facilities be subject to the
CISWI standards instead of the SSI standards. The commenter (90.1) states that there currently
are no commercial and industrial facilities that are burning sewage sludge in their incinerators.
The commenter (90.1) suggested that EPA use language similar to that of the Part 503
regulations, which state that if municipal solid waste is utilized as an auxiliary fuel in a sewage
sludge incinerator, that the waste cannot exceed 30% of the dry weight of the sewage sludge and
the auxiliary fuel together, and that if the 30% threshold is exceeded, the incinerator will be
regulated as a solid waste incinerator. The commenter (90.1) further notes that pelletized sewage
sludge is burned as an auxiliary fuel in cement kilns, and that operators for other industries have
considered sewage sludge as an auxiliary fuel. The commenter (90.1) suggests that, in these
cases, if the 30% threshold is not exceeded, then the cement kiln rule or other applicable rule
should apply.
Several commenters (52.1, 66.1, 95.1, 100.1, 57, 59) contended that EPA should exempt
incineration units subject to hazardous waste combustor regulations and/or hazardous waste
management permits issued under the Solid Waste Disposal Act from the proposed sewage
sludge incineration standards. These commenters (52.1, 66.1, 95.1, 100.1, 57, 59) emphasized
that the CAA section 129(g)(l) states that a solid waste incineration unit does not include
incinerators or other units required to have a permit under section 3005 of the SWDA. The
commenters (52.1, 66.1, 95.1, 100.1, 57, 59) requested EPA include the four statutory
exclusions, and particularly the exclusion for units which are required to have a permit under
section 3005 of the Solid Waste Disposal Act. Additionally, four of these commenters (52.1,
66.1, 95.1, 57, 59) requested EPA include an exemption for hazardous waste combustion units
that are affected sources under 40 CFR 63 Subpart EEE.
One commenter (86.1) suggested that EPA should extend the proposed Section 60.4780
and Section 60.5065 exclusions to all solid waste incineration units that meet the applicability
requirements of other Section 129 NSPS and EG rules, including MWCs regulated under
Subparts Ea, Eb, Cb, AAAA, and BBBB. The commenter (86.1) stated that this exemption
would be consistent with EPA's proposed CISWI NSPS and EG rules which explicitly exempt
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MWC units subject to these other Section 129 rules (75 FR 31974, Section 60.2020(c); 75 FR
31990, Section 60.2555(c)).
Response: Section 129 defines solid waste incineration unit to include any unit
combusting any solid waste. Section 129(g)(l) clarifies that the term 'solid waste incineration
unit,' does not include incinerators or other units required to have a permit under section 3005 of
the Solid Waste Disposal Act [42 U.S.C.A. § 6925]. The term 'solid waste incineration unit,'
does not include (A) materials recovery facilities (including primary or secondary smelters)
which combust waste for the primary purpose of recovering metals, (B) qualifying small power
production facilities, as defined in section 796(17)(C) of Title 16, or qualifying cogeneration
facilities, as defined in section 796(18)(B) of Title 16, which burn homogeneous waste (such as
units which burn tires or used oil, but not including refuse-derived fuel) for the production of
electric energy or in the case of qualifying cogeneration facilities which burn homogenous waste
for the production of electric energy and steam or forms of useful energy (such as heat) which
are used for industrial, commercial, heating or cooling purposes, or (C) air curtain incinerators
provided that such incinerators only burn wood wastes, yard wastes and clean lumber and that
such air curtain incinerators comply with opacity limitations to be established by the
Administrator by rule. Those units that are exempt from the definition of solid waste incineration
unit under the Act are not subject to the SSI standards.
EPA is not establishing de minimus levels of solid waste that can be burned in
incinerators but not subject to the SSI standards. The CAA defines solid waste incineration unit
to mean any unit combusting any solid waste, and EPA does not believe that a de minimis
exemption is appropriate where a unit is combusting some solid waste. Therefore, any amount of
sewage sludge combusted in an incinerator located at a wastewater treatment facility designed to
treat domestic sewage sludge is subject to the final SSI standards. In the proposed rules, we had
inadvertently left in a definition for co-fired combustor. However, the definition was not used in
the rule and we did not propose any requirements for co-fired combustor. This definition has
been removed from the final rules.
We have clarified that the final standards and guidelines only apply to sewage sludge that
is burned in an SSI located at a wastewater treatment facility designed to treat domestic sewage
sludge. Sewage sludge that is not burned in an SSI located at a wastewater treatment facility
designed to treat domestic sewage sludge is subject to other section 129 standards, such as the
CISWI standards (40 CFR part 60, subparts CCCC and DDDD of this part), the OSWI standards
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(40 CFR part 60, subparts EEEE and FFFF), the MWC standards (40 CFR part 60, subparts Ea,
Eb, Cb, AAAA, and BBBB of this part) or the Hazardous Waste Combustor rule (40 CFR part
63 subpartEEE).
Hazardous waste combustion units that are required to have a permit under CAA section
3005 or the Solid Waste Disposal Act are exempt from CAA section 129 standards per CAA
section 129(g)(l), therefore we do not believe an exemption is needed for this rule.
Comment: Two commenters (110.1, 92.1, 104.1) were concerned that the definition of
SSI units in §60.5250 is not specific enough. One commenter (110.1) stated that there is
confusion as to whether gasification units are covered by the proposed sewage sludge
incineration standards because there is no mention of gasification in the preamble or proposed
rule. The commenter (110.1) suggested that the proposed sewage sludge incineration standards
include a non-applicability section in which it explicitly states that no other biosolids
management options (ie, land application, landfilling, surface disposal, thermal drying, etc.) are
affected by this action. The commenter (110.1) also stated that there should be an applicability
section of the rule to state what exactly is covered by the regulation. Another commenter (92.1,
104.1) requested that EPA either more closely define SSI units under §60.5250 to explicitly
include or exclude stack evaporation, or add an exemption under §60.5065 for flash evaporation
units. The commenter (92.1, 104.1) stated that it is unclear whether the definition of SSI unit in
§60.5250 is meant to include flash evaporation units that use stack-injection in a gas turbine's
exhaust to flash evaporate sewage sludge. At least one commenter (88.1) stated that the rule
should include a definition of "combustion" as an oxidative process. The commenter (88.1) noted
that this definition is necessary to distinguish it from gasifying operations, such as the ones used
in biosolids-to-diesel fuel programs. The commenter requested that, alternatively, EPA should
clarify that gasifiers are unequivocally excluded from the regulations.
Response: We have revised the definition of sewage sludge to clarify that methods of
sewage sludge disposal other than combustion are not subject to the SSI standards. We have also
clarified that this action does not address other methods of disposal for sewage sludge (e.g. land
application, landfilling, surface disposal,fertilizer). EPA has clarified in the final rule that sewage
sludge that is not burned in an SSI unit located at a wastewater treatment facility designed to
treat domestic sewage sludge is subject to other section 129 standards, such as the CISWI
standards (40 CFR part 60, subparts CCCC and DDDD of this part), the OSWI standards (40
CFR part 60, subparts EEEE and FFFF), the MWC standards (40 CFR part 60, subparts Ea, Eb,
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Cb,AAAA, and BBBB of this part) or the Hazardous Waste Combustor rule (40 CFR part 63
subpart EEE). Facilities that are unsure if their process is a combustion process, are welcome to
submit a formal applicability determination to the Agency.
Comment: One commenter (76.1) requested that improvements to existing MH
incinerators to meet the new MH emission guidelines be specifically exempt from NSR and
Subpart LLLL: New FBI Units.
Response: EPA has revised the proposed rule to subcategorize new units into two
subcategories, as explained elsewhere in this document. Therefore, new MH units are a separate
subcategory from new FB units. Today's action does not address or affect any requirements that
may apply under NSR.
3.2 Definition of Modification
Comment: Several commenters (96.1, 109.1, 134.1) requested clarification regarding the
definition of "modification". One commenter (134.1) requested clarification regarding whether
the "modification" (which refers to an "SSI unit") applies to the multiple hearth or fluid bed
"reactor" or whether it includes the entire system including all air emission controls and auxiliary
equipment. Other commenters (109.1) noted that 40 CFR 60.14 (e)(5) specifically states that
addition of pollution control equipment to reduce emissions is not considered a "modification"
and does not trigger the new source rules. One commenter (109.1) stated that the EPA should
also address whether or not the existing NSR provisions for "Pollution Control Project"
exclusions will also be incorporated in these proposed 129 rules that allows for sources to install
new emission control equipment without triggering the "new source" designation. At least one
commenter (76.1) requested that EPA clarify that existing SSIs that make modifications to meet
the limits do not constitute a "major modification" under Title V and are not subject to NSR and
the NSPS (Section LLLL) for new SSIs.
Other commenters (109.1, 134.1) requested clarification on what is included in the 50%
cost rule determination; one commenter (109.1) stated that the inclusion of the words
"cumulative cost of the changes over the life of the unit" is not consistent with what has been
used previously with other NSPS and NSR rule language regarding the "modification" cost
determinations, which do not include the "cumulative" designation. One commenter (96.1)
requested that EPA clarify the definition of modification to mean greater than 50% of the cost of
a new or replacement SSI fluidized bed unit in today's dollars. The commenter (96.1) stated that
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even if advanced emission controls were not counted towards the 50% cost threshold, the costs
for needed improvements for a facility may easily exceed the 50% threshold amount. One
commenter (76.1) suggested that Section 60.5060 of Subpart LLLL should be revised to state
that construction started after the compliance deadline (not 6 months after the promulgation of
the final rule) could be considered a modification if the cost is more than 150% of the
replacement costs of existing SSI in current dollars. Another commenter (134.1) requested that
only modification costs required to comply with the proposed rule be included, and that routine
maintenance or "in-kind" replacement costs be excluded.
Other commenters (97.1 and 127.1) suggested that EPA ignored the "modification"
trigger for the new source standards because EPA's proposed definition of "modification" could
make existing MH SSIs subject to the new source FB based standards. The commenters (97.1
and 127.1) state that EPA would impose the new standards on units for which the "cumulative
cost of the changes over the life of the unit exceeds 50 percent of the original cost of building
and installing the SSI unit." The commenters (97.1 and 127.1) urged EPA to make clear in the
final SSI rule that the cumulative costs to be considered are only those costs incurred since the
effective date of the final SSI rule since this is the approach taken in the Municipal Waste
Combustor § 129 rule at 40 CFR § 60.5Ib. The commenter (97.1 and 127.1) is concerned that
the "life of the unit" reference in the definition of modification could be misconstrued as a
retroactive evaluation of incurred costs that pre-date the rule.
Several commenters (101.1, 102.1, 109.1) contended that the proposed new source
performance standards would severely restrict or discourage a POTWs from modifying an
existing MH incinerator, including modifications to improve combustion efficiency, boost steam
output for electricity generation, or modernize emission control equipment. The commenters
(102.1) added that the term "modifications" as utilized in the proposed standard either needs to
be clearly defined or removed because it can currently be interpreted in both wide ranging and
very narrow views depending on the end goal in mind.
Response: The definition of "modification" in the proposed and final rule is consistent
with the statutory definition of "modification" in Section 129(g) of the CAA. A unit becomes
"modified" only by a change to an existing SSI unit that occurs later than 6 months after the date
of subpart LLLL publication in the Federal Register if one of two criteria are met:
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(1) The cumulative cost of the changes over the life of the unit exceeds 50 percent of the
original cost of building and installing the SSI unit (not including the cost of land), updated to
contemporaneous year dollars; or
(2) Any physical change in the SSI unit or change in the method of operation that
increases the amount of any air pollutant emitted for which section 129 or section 111 of the
CAA has established standards.
The trigger date for when a modification occurs, 6 months after publication of the final
rule in the Federal Register., is required by section 129 of the CAA. Section specifies that the
trigger date is "...after the effective date of a standard under section (a)..." of section 129. The
effective date for new SSI units in section (a) is 6 months following rule publication, and
therefore, is the trigger date for a modified SSI unit. However, if the cumulative costs over the
life of a unit exceed the 50 percent criterion, the unit is not classified as a modified unit unless
that change occurs after the effective date (i.e., 6 months after publication of this rule).
The costs to consider for determining if the 50 percent criterion is met are the costs of the
combustion unit and all associated ancillary equipment, excluding air pollution control
equipment. The commenter is correct that the definition of the SSI unit in the proposed rule was
unclear as to what equipment constitutes the SSI unit. We have modified the definition of SSI
unit in the final rule. While not all SSI units will include all of the following components, a SSI
unit includes, but is not limited to, the sewage sludge feed system, auxiliary fuel feed system,
grate system, flue gas system, waste heat recovery equipment, if any, and bottom ash system.
The SSI unit includes all ash handling systems connected to the bottom ash handling system. The
combustion unit bottom ash system ends at the truck loading station or similar equipment that
transfers the ash to final disposal. The SSI unit does not include air pollution control equipment
or the stack.
A commenter was incorrect in stating that the cumulative costs should be only those costs
incurred after the effective date of the rule and that this rule is inconsistent with the approach
taken for the Municipal Waste Combustor (MWC) section 129 rule. Section 129 clearly specifies
that the cumulative costs are those incurred over the life of the unit. These costs, however, do not
include maintenance, repair, or replacements that the Administrator considers to be routine for
the source category, as prescribed in section 60.14(e). The definition of a modified unit in this
rule is conceptually identical to the definition of modification in the MWC rule.
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A commenter also is incorrect is stating that improvements to the unit to comply with the
rule may exceed 50 percent and therefore trigger stringent new source requirements. Section
60.5060 states that physical or operational changes made to your SSI unit primarily to comply
with the State plan prepared for subpart MMMM (Emission Guidelines and Compliance Times
for Existing Sewage Sludge Incineration Units) do not qualify as a modification under this rule.
Regarding the comments that under the proposed rule the new source requirements for
multiple hearth incinerators would discourage modifications for the purpose of improving energy
efficiency, as explained in section 6.0 of this document, the final rule contains separate emission
limits for multiple hearth combustion units improvements such that the new source requirements
are reasonable and achievable.
We are making no changes to the rule regarding applicability of SSI units to the
modification requirements under Title V or New Source Review (NSR) permitting. Both Title v
and NSR rules address how pollution control projects are handled, and it is not within the scope
of the SSINSPS and guidelines rulemaking to revise the provisions of either of these permitting
programs.
3.3 Applicability Dates
Comment: One commenter (76.1) contended that EPA should increase the compliance
time from 3 to 5 years after State Plan adoption and 5 to 7 years after Federal adoption. The
commenter (76.1) stated that compliance within 3 years after adoption of the State Plan or
5 years after Federal adoption is not enough time to follow standard engineering practices which
may include conducting pilot studies to verify design parameters, preparing and approving
environmental documents, obtaining regulatory permits, pre-design, design, value engineering,
final design, prequalification of contractors, bidding and award, and finally construction. One
commenter (115.1) stated that a 5-year deadline (January 2016) to meet proposed regulations
could be difficult to accomplish due to FEMA flood recovery timelines and approval process.
Response: The NSPS are directly enforceable federal regulations, and under CAA
section 129 (f)(l), become effective 6 months after promulgation. Under CAA section 129 (f)(2),
the EG become effective and enforceable 3 years after EPA approves a state plan implementing
the EG or 5 years after the date they are promulgated, whichever is sooner. The state plan must
be "at least as protective as" the EG and must ensure compliance with all applicable
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requirements not later than 3 years after the state plan is approved by EPA, but not later than 5
years after the relevant EG are promulgated.
The final EG requires existing SSI to demonstrate compliance with the standards as
expeditiously as practicable after approval of a state plan, but no later than three years from the
date of approval of a state plan or five years after promulgation of the EG, whichever is earlier.
Consistent with CAA section 129, EPA expects states to require compliance as expeditiously as
practicable. However, because we believe that many SSI units will find it necessary to retrofit
existing emissions control equipment and/or install additional emissions control equipment in
order to meet the final limits, EPA anticipates that states may choose to provide the 3-year
compliance period allowed by CAA section 129(f)(2). If EPA does not approve a state plan or
issue a federal plan, then the compliance date is five years from the date of the final rule.
EPA intends to develop a federal plan that will apply to existing SSI units in any state
that has not submitted an approved state plan within two years after promulgation of the EG. The
final EG allows existing SSI units subject to the federal plan up to five years after promulgation
of the EG to demonstrate compliance with the standards, as allowed by CAA section 129(b)(3).
3.4 Definition of Solid Waste
Comment: Some commenters (83.1, 71.1, 90.1) objected to EPA's issuance of the
proposed sewage sludge incineration standards because EPA has not made any determinations
regarding the definition of non-hazardous solid waste in the June 4 proposed rule titled
"Identification of Non-Hazardous Secondary Materials That Are Solid Waste (40 CFR Part
241)"; at least two commenters (73.1, 76.1) stated that EPA should delay any rule-making on
SSIs until the definition of "solid waste" is finalized. Several commenters (71.1, 90.1, 102.1,
116.1, 102.1, 116.1,83.1,97.1, 127.1, 121.1) argued that sewage sludge is not a solid waste;
some commenters (71.1, 90.1) argued that there is no legal basis to begin an administrative
procedure to adopt standards to control emissions from sewage sludge. One commenter (83.1)
recommended that EPA determine in response to the comments filed with regard to the June 4
proposed rule that sewage sludge is exempted under RCRA's DSE from Section 129 CAA
regulation. Atleast three commenters (83.1, 97.1, 127.1) pointed out that the CAA defines solid
waste by referencing the definition of solid waste under RCRA. Two of these commenters (97.1,
121.1, 127.1) argued that it is explicitly noted in the RCRA definitions that solid waste "...does
not include solid or dissolved material in domestic sewage." Several commenters (83.1, 97.1,
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121.1, 127.1) stated that this language expressly excludes the sewage sludge in domestic sewage
from the definition of "solid waste" in what is commonly referred to as the "Domestic Sewage
Exclusion" ("DSE"). The commenters (97.1, 127.1) stated that there was an early recognition
that a comprehensive solid waste program, designed primarily to address hazardous wastes, did
not apply to POTWs as long as they were effectively regulated under the CWA, which has
always been and remains the primary statutory authority for comprehensive regulation of POTW
operations. The commenters (97.1, 127.1) argued that The Solid Waste Disposal Act and RCRA
included the DSE in explicit recognition of this critical policy choice [Footnote: Solid Waste
Disposal Act, Pub. L. No. 89-272, § 203(4), 79 Stat. 992, 998 (1965) (defining the term "solid
waste" to exclude "solids or dissolved material in domestic sewage or other significant pollutants
in water resources . . . ."); accord Resource Conservation and Recovery Act, Pub. L. No. 94-580,
§ 1004, 90 Stat. 2795, 2801 (1976)].
Commenters (83.1) stated that although EPA concludes in its June 4 proposed rule that it
has "...long viewed sewages sludge generated from POTWs as a solid waste, beginning with the
1980 Identification and Listing of Hazardous Waste rulemaking," EPA's statement is
contradicted by its determination in 1990 that: "...if wastewaters generated at petroleum
refineries are discharged to a POTW and such wastewaters are mixed with domestic sewage
from nonindustrial sources, the sludges generated in the POTW are covered under the domestic
sewage exclusion..." One commenter (97.1, 127.1) argued that sewage sludge and solid waste are
different types of material because EPA's careful regulatory approach in the Part 503 regulations
distinguishes between sewage sludge and solid waste. The commenter (97.1, 127.1) used the
preamble to the Part 503 rules to show this distinction: "The standards also do not apply to
sewage sludge that is co-incinerated with large amounts of solid waste .... However, the
standards established in the rule do apply to sewage sludge that is incinerated in a sewage sludge
incinerator with incidental amounts of solid waste use as an auxiliary fuel (i.e., 30 percent or less
solid waste by weight)." [58 Fed. Reg. 9248, 9253].
Another commenter (97.1, 127.1) also pointed out that EPA had interpreted the scope of
the DSE to include sewage sludge generated by POTWs in the preamble to the Agency's 1990
Final Rule to identify and list hazardous wastes for petroleum refinery process wastewaters. The
commenter (83.1) stated that EPA's 1990 pretreatment regulation also strongly suggests that
sewage sludge is covered by the DSE. The commenter (97.1, 127.1) stated that there has been a
clear recognition for over 30 years that sewage sludge is different than solid waste for regulatory
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purposes, and that sewage sludge is primarily regulated under the CWA, not RCRA. Other
commenters (76.1) argued that sludge from a wastewater treatment plant is not a hazardous
waste and should not be regulated as one. The commenters (76.1) argued that to regulate sludge
from a WWTP as hazardous waste would be a waste of public money and resources and
requested EPA to write the regulation for the wastewater industry. Commenters (83.1) further
stated that it would be illogical for EPA to laud its CWA Part 503 sewage sludge regulations as a
method for addressing the proper treatment of DSE materials, but then refuse to define sewage
sludge as a DSE material. The commenter (83.1) requested EPA issue a final regulation finding
that sewage sludge is not a solid waste per the RCRA definition, thereby releasing POTWs from
any obligations to comply with CAA section 129. The commenter (83.1) stated that POTWs that
manage sewage sludge materials are highly regulated under EPA's Part 503 CWA regulations.
One commenter (111.1) argues that EPA's proposed rule is incorrectly based on the
determination that biosolids are a solid waste because it conflicts with two Washington State
policies: that sewage sludge and biosolids are not a solid waste, and that there are regulations in
place to restrict landfilling of sewage sludge. The commenter (111.1) encouraged EPA to
consider the classification of biosolids as solid waste in light of determinations from State and
Federal environmental agencies.
Conversely, one commenter (77.1) supported the proposed EPA position to classify
sewage sludge as a solid waste and establish emission standards for sewage sludge incinerators
under Section 129 of the Clean Air Act. The commenter (77.1) stated that Section 405(d) of the
Clean Water Act directed EPA to establish standards for all of the common sewage sludge
management options including land application, surface disposal, and incineration under the Part
503 Rule; however, the promulgation of that rule did not change the status of sewage sludge as a
solid waste with the potential for future additional regulations under CAA or RCRA authority.
Response: These comments are not relevant to EPA's establishment of emissions
standards for SSI units. Rather, they are relevant to EPA's proposed Identification of Non-
Hazardous Secondary Materials That Are Solid Waste rule, and are addressed in the EPA's final
action on that proposed rule.
Comment: One commenter (48.1) questioned whether any thought had been given to a
better define of the term "solid". The commenter (48.1) argued that sewage sludge is a non-
hazardous primary material that clearly is processed in their facility exclusively for use as fuel
and should not be considered solid waste. The commenter (48.1) stated that even the word
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"solid" belies the very nature of sludges, which are a liquid, incapable of holding a shape and
required to be contained or they run as any liquid would. The commenter (48.1) stated that
sewage sludge is appropriately subject to section 112 of the CAA; and the consideration of
human sewage sludge as solid waste is arbitrary.
Other commenters (102.1, 116.1) argued that sewage sludge is not "solid waste", but a
by-product of the wastewater process. The commenters (102.1, 116.1) stated that when sewage
enters a wastewater facility it is basically 99.5% water; the 0.5% solid material is further
separated and processed until it reaches a digestion or thickening process where it is 97-99%
water or 1-3% bio-solids. The commenters (102.1, 116.1) stated that it is further de-watered by
various process equipment to a point where it is somewhere between 15-30% bio-solids or still
70- 85% water. The commenters (102.1, 116.1) stated the de-watered solids (15-30%) are
conveyed into either a MH or FB unit for incineration and reduction of volatile solids. The
commenter (102.1, 116.1) stated that the incinerator units are almost always on the same site as
the liquid side of the wastewater processing facilities and are in fact an integral portion of the
treatment plant plan and process. The commenters (102.1, 116.1) urged EPA to properly define
and categorize "sewage sludge" because there are numerous factors which affect the chemical,
physical, and thermodynamic properties of the actual composition of sewage sludge including:
the residential, commercial and industrial users of the collection system, the processes used at the
wastewater treatment plant (WWTP), the chemicals used at the WWTP, types of sludge
produced, type of sludge dewatering systems used, the operations at the WWTP (sludge
detention times in tanks and clarifiers). The commenters (102.1, 116.1) stated that all of these
factors affect the de-watering of the sludge and the characteristics of the final sludge which is
sent to the SSI.
Response: This comment is not relevant to EPA's establishment of emissions standards
for SSI units. Rather, it is relevant to EPA's proposed Identification of Non-Hazardous
Secondary Materials That Are Solid Waste rule, and is addressed in the EPA's final action on
that proposed rule.
Comment: One commenter (86.1) expressed concern with the use of the terms "clean
biomass" and "other solid wastes" in the "co-fired combustor" definition of the proposed sewage
sludge incineration standards. The commenter (86.1) stated that depending on the outcome of the
NHSM Rule which was proposed June 4, 2010, it is possible that some biomass materials (say,
for example, urban demolition wood) would be neither "clean" nor classified as "solid waste",
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thereby excluding these materials from the co-fired combustor definition in the proposed sewage
sludge incineration standards. The commenter (86.1) added that EPA can solve this potential
problem by striking the adjective "clean" from biomass in the "co-fired combustor" definition.
The commenter (86.1) stated that since EPA's intent appears to be to include all biomass, either
as clean material or solid waste, deleting "clean" from the definition would assure its intent is
fulfilled regardless of the outcome of the NHSM Rule.
Response: This comment is not relevant to EPA's establishment of emissions standards
for SSI units. Rather, it is relevant to EPA's proposed Identification of Non-Hazardous
Secondary Materials That Are Solid Waste rule, and is addressed in the EPA's final action on
that proposed rule. EPA is not establishing de minimus levels of solid waste that can be burned
in incinerators but not subject to the SSI standards. The CAA defines solid waste incineration
unit to mean any unit combusting any solid waste, and EPA does not believe that a de minimis
exemption is appropriate where a unit is combusting some solid waste. Therefore, any amount of
sewage sludge combusted in an incinerator located at a wastewater treatment facility designed to
treat domestic sewage sludge is subject to the final SSI standards. In the proposed rules, we had
inadvertently left in a definition for co-fired combustor. However, the definition was not used in
the rule and we did not propose any requirements for co-fired combustor. This definition has
been removed from the final rules.
Comment: Two commenters (73.1, 108.1) are concerned that the proposed rule changes
will exert a negative effect on efforts across the country to use biosolids as a carbon neutral,
renewable energy source. One commenter (108.1) stated that by defining biosolids as a non-
hazardous solid waste for combustion purposes in the manner employed in the proposed rule
implies that biosolids are a material to be disposed of rather than a resource with energy value.
The commenter (108.1) stated they vehemently disagree with the rule where it explicitly states
that such energy recovery is "sham recycling". The commenter (108.1) wrote about a project
they are working on that seeks to recycle biosolids for a community energy benefit. The
commenter (108.1) urged EPA to reconsider defining biosolids as municipal solid waste stating
that biosolids are a valuable resource used as soil amendments, fertilizer, and fuel; as such, they
should not be considered a waste.
Specifically, one commenter (73.1) stated that EPA should not determine that sewage
sludge pellets are a solid waste before the Proposed Rule on Identification of Non-Hazardous
Secondary Materials That Are Solid Wastes (Docket ID No. EPA-HQ-RCRA-2008-0329) is
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finalized. The commenter (73.1) urged EPA to define sewage sludge pellets as a non-hazardous
secondary material that is a solid waste. The commenter (73.1) specifically argued that sewage
sludge pellets should not be considered a solid waste, but rather a renewable fuel. The
commenter objects to the Agency's determination, and refutes the "Legitimacy Criteria"
proposed by the Agency in 241.3(d)(l) of the proposed solid waste determination.
The commenter (73.1) stated that as the nation is striving to achieve stated policy of
producing as much green energy as possible, all such avenues should be encouraged and
facilitated. The commenter (73.1) stated that dried sewage sludge pellets which are used as
biogenic alternative fuels, or otherwise produce energy should be recognized as such and not
have regulatory roadblocks constructed to impede such uses. The commenter (73.1)
recommended that in order to support the Nation's policy to use renewable fuels, the Proposed
Rule should explicitly exempt a de minimus percentage (less than 30% of the overall fuel
consumption of the facility) of sewage sludge pellets combusted in abiomass facility, cement
kiln, or other combustion facility that beneficially uses sewage sludge pellets as a fuel before
subjecting such a facility to CAA §129 regulations. The commenter (73.1) recommended that
language be added to mirror 40 CFR part 503 whereby a combustion unit is only considered a
SSI if it combusts more than 30% by weight sewage sludge. The commenter (73.1) stated that
California heat dried sewage sludge is sometimes used in cement kilns as an alternative fuel to
coal. The commenter (73.1) is concerned that the cement kiln, having accepted dried sewage
sludge as fuel, would be regulated under both §112 and §129 of the CAA.
Response: This comment is not relevant to EPA's establishment of emissions standards
for SSI units. Rather, it is relevant to EPA's proposed Identification of Non-Hazardous
Secondary Materials That Are Solid Waste rule, and is addressed in the EPA's final action on
that proposed rule.
3.5 Other
Comment: One commenter (84.1, 119.1) contended that EPA should make the proposed
sewage sludge incineration standards expressly applicable to SSI units operated on passenger
vessels such as large cruise ships because they produce large amounts of biomass that must be
dealt with. The commenter (84.1, 119.1) referenced a study indicating between 15to 40 metric
tons of biomass are produced per day. The commenter (84.1, 119.1) included an attached 2009
study published by the Port of Seattle that provides details of cruise vessel biomass management.
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The commenter (84.1, 119.1) expressed concern that such operating plans cannot be verified, and
that biomass was being incinerated close to the U.S. shore.
Response: EPA defines the term 'stationary source' to mean generally any source of an
air pollutant except those emissions resulting directly from an internal combustion engine for
transportation purposes or from a nonroad engine or nonroad vehicle as defined in section 7550
of this title. A passenger vessel or other type of ship that is not propelled by a non-road engine
(e.g. boiler), then the passenger vessel or ship would be considered a stationary source.
Therefore, any air emissions from an incineration unit combusting non-hazardous solid waste on
the ship would be subject to Section 129. A passenger vessel or other type of ship that is
propelled by a non-road engine (e.g. diesel engine) then the passenger vessel or ship would be
considered a mobile source. Therefore, any emission point location on the source would be part
of the mobile source emissions. 'Mobiles source' is a term used to describe a wide variety of
vehicles, engines, and equipment that generate air pollution and that move, or can be moved,
from place to place.
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4.0 EMISSION LIMITS AND GUIDELINES
4.1 Metals
Comment: Several commenters (58, 105.1, 138, 135.1, 101.1, 126.1) are concerned
about the proposed mercury emission limits. One commenter (58) stated that the removal
methods EPA described to meet the proposed mercury limits are unproven and expects costs to
upgrade their incinerators to be too high. Another commenter (105.1) is concerned whether the
proposed mercury limits can be consistently met as they compared the limit to past stack test
results and found that in order to meet the mercury limit they would need an excess of 85%
control. Another commenter (135.1) mentioned that a number of SSIs have invested significant
money making improvements to their process to improve performance and reduce mercury
emissions, but the proposed standards will penalize these facilities. The commenter (135.1) is
concerned that the higher mercury concentration in the flue gas of these facilities will require
higher control efficiency than anticipated by EPA to achieve the concentration based standard.
Two other commenters (101.1, 126.1) stated that their sewage sludge incinerators will be able to
meet the proposed NSPS for existing MHIs, except for the proposed limits for mercury. The
commenter (126.1) stated that to be able to meet the mercury limit of 0.02 mg/dscm @ 7%
oxygen proposed for existing Mills, new APC equipment must be provided to remove 0.00701
tons of mercury each year from the incinerator exhaust gases (an annual average Hg control
efficiency of 79.2%).
Response: EPA proposed a beyond-the-floor mercury limit for SSI units. However, after
evaluating the revised emissions dataset (see the memorandum "Post-Proposal SSI Database
Revisions and Data Gap Filling Methodology"( EPA-HQ-OAR-2009-0559) for further details )
and re-evaluating the types of controls needed to go beyond-the-floor, EPA concluded that it
would not be cost effective to go beyond-the-floor for mercury control. Therefore, the final
mercury emission limits are 0.037 mg/dscm for FB units (as opposed to the proposed limit of
0.0033 mg/dscm) and 0.28 mg/dscm for MH units (as opposed to the proposed limit of 0.02
mg/dscm).
Comment: One commenter (67.1) stated the proposed sewage sludge incineration
standards for cadmium and lead are unrealistically low and may not be measurable or achievable
with any technology.
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Response: The MACT floor limits are based on EPA's variability analysis, which is
described in the memorandum, "Revised MACT Floor Analysis for the Sewage Sludge
Incinerator Source Category" in the SSI docket (EPA-HQ-OAR-2009-0559). For units for which
test data were available, cadmium and lead concentration averages were below the final
cadmium and lead emission limits for all but one unit (a MH unit). For this unit, and units for
which no data were available an which may require control, EPA believes the final metals limits
for existing units are achievable with the addition of either a venturi scrubber or a wet
electrostatic precipitator (see revised compliance cost and reductions memo for further details).
In the NPRM we requested additional emissions information. However, no new emissions test
information was received. Based on the data available, we are aware of a number of SSI units
that are currently able to meet the emission limits for all the pollutants.
Comment: One commenter (54.1, 60.1) stated that PM is not a surrogate for metals
control, and also disagreed with EPA's use of PM mass in its cost-benefit analysis calculations.
The commenter (54.1, 60.1) recommended EPA require multi-metal CEMS to demonstrate
compliance with HAP metal emission limits. The commenter (54.1, 60.1) argued thatPM does
not meet the court-defined criteria for HAP metal surrogacy under EPA-recognized conditions,
as stated in its current proposed rules as well as under previously proposed rules (CISWI). The
commenter (54.1, 60.1) stated that in a 2004 case Sierra Club v. EPA and others, the Court of
Appeals established a three-part test for surrogacy based on their earlier ruling in National Lime.
Sierra Club v. EPA, 353 F.3d 976 (D.C. Cir. 2004)("Copper Smelter MAGI"); and all three
criteria must be met to use PM as a surrogate for HAP metals. The commenter (54.1, 60.1)
quoted EPA from page 63268 part A of the proposed SSI rules: "EPA understands that the metal
emissions from SSI units are influenced by the metals content in the sludge burned". The
commenter (54.1, 60.1) argued that if an emission source can change the output concentration of
metals by changing the input, but it doesn't change the PM mass, then PM is not an effective
surrogate for metals.
Response: We are not using PM as a surrogate for metals. Section 129 of the Clean Air
Act requires EPA to set emission standards for 9 pollutants, including PM, Hg, Cd, and Pb. We
have done so in the proposed and final rules. The final rule is structured around periodic
performance testing that demonstrate compliance with the emission limits with contemporaneous
collection of process and control device operating conditions to use in establishing enforceable
operating limits sufficient to assure continuous compliance. We believe that the combination of
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periodic performance testing and continuous monitoring of monitoring of site-specific operating
limits tied to the performance testing will provide an adequate assurance of compliance. In
addition, for existing SSI units, the rule allows the use of Cd, CO, HC1, NOx, PM, Pb or SO2
CEMS; ISTMMS; and ISTDMS (continuous sampling with periodic sample analysis) as
approved alternatives to the parametric monitoring and annual compliance testing. For new SSI
units, CO CEMS are required for determining continuous compliance, and use of Cd, HC1, NOx,
PM, Pb or SO2 CEMS; ISTMMS; and ISTDMS (continuous sampling, with periodic sample
analysis) are approved alternatives to parametric monitoring and annual compliance testing.
Additionally, at this time, EPA does not have a promulgated performance specification
for multi-metal CEMS and cannot require it be used.
4.2 PM
Comment: Several commenters (76.1, 97.1, 127.1, 110.1, 129.1, 54.1, 60.1, 86.1, 134.1)
supported EPA's decision to not include PM2.5 standards in the sewage sludge incineration
standards. One commenter (86.1) also stated that EPA should not recognize the OTM 27/28
methods for PM performance testing because the methods measure not only PM actually present
in the flue gas but also any particulate matter formed from the interaction and condensation of
gaseous organic/inorganic flue gas constituents in the sampling train, and thereby measure and
report PM which is beyond the capability of the PM control device selected as MACT. In
addition, the commenter (86.1) stated that OTM 27/28 methods have not been validated on SSIs
as mandated by Section 129. Another commenter (97.1, 127.1) stated that it is reasonable for
EPA to control both total and fine particulate by using surrogates because the use of wet
scrubbers is not always compatible with OTM 27. The commenter (97.1, 127.1) stated that
entrained water droplets that occur when stack gas moisture levels exceed vapor capacity can
bias PM2.s particle measurements and provide inaccurate readings of filterable PM2.s. The
commenter (97.1, 127.1) also stated that the same control devices would be required to control
both total and final particulate, and cited Cf Nat'l Lime Assoc. v. EPA, 233 F.3d 625, 637 (D.C.
Cir. 2000) (citing Dithiocarbamate Task Force v. EPA, 98 F.3d 1394, 1399 (D.C. Cir. 1996)).
The same commenter (97.1, 127.1) referenced a document [Footnote: Russell R. Dickerson et al.,
PM2.5 Maryland State Implementation Plan Weight of Evidence Report 4-40 to 6-40 (Jan. 30,
2008)] that supports correlations between reductions in SO2 and NOX and reductions in nitrate
and sulfate contributions to PM2.s. Another commenter (54.1, 60.1) stated that the difficulties
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existing for measurement of PM2.5 demonstrates a clear example of why PM2.5 is not an
appropriate tool for modeling or assessing health effects of toxic PM components, such as
metals. Two commenters (76.1, 97.1, 127.1) said that limits on filterable particulate matter and
opacity provide an adequate surrogate for direct fine particulate matter contributing to PM2.5.
Response: For the final rule, EPA maintains that it is not appropriate to set limits for
PM2.5 for the reasons discussed in the NPRM.
4.3 CO
Comment: Some commenters (65.1, 125, 77.1, 145.1, 134.1) are concerned about the
proposed CO emission limits. One commenter (65.1) suggested that setting the MACT floor
limit of 56 ppmvd for CO on existing FB incinerators is somewhat over kill and states that time
does not permit calculation of the additional fuel and the resulting CO2 emissions generated to
assure this level is reached at all times. The same commenter (65.1) also stated that the MACT
floor limit of 7.4 ppmvd for CO on new SSI units is more stringent than any emission limit for
CO anywhere in the world. The commenter (65.1) speculated after reviewing the data presented
that the 7.4 ppmvd CO limit was based solely on six one-hour tests at YCUA on a brand new
incinerator being operated to demonstrate performance to the owner. The commenter (65.1)
stated that continuous CO emission compliance with a standard of 7.4 ppmvd corrected to 7% 02
is not possible, and urged EPA to see how the unit performs after four years of operation.
Another commenter (125) provided a review of BACT for CO emissions from natural gas-fired
turbines and surmised that it does not seem reasonable to require a biosolids-fired FB to meet an
emission standard that is equivalent to those of a natural gas-fired combustion device. The
commenter (125) stated that using best combustion practices the CO emissions from biosolids-
fired FBs are already low, as shown by the baseline CO concentrations of 16.3 ppmdv @ 7% 02.
The commenter (125) argued that new FB units will likely require the addition of an afterburner
or thermal oxidizer to meet the proposed CO emission standard of 7.4 ppmdv @ 7% O2, and that
the afterburner or thermal oxidizer will combust natural gas, generating its own NOX and CO
emissions. The same commenter (125) further argued that the requirement to add an afterburner
or thermal oxidizer to a FB in order to meet the CO emission standard will not decrease the
overall CO emissions and will increase NOX emissions and other pollutant emissions from the
process. Another commenter (77.1) stated that the proposed CO limit of 3900 ppm for existing
MH incinerators is a significant loosening of this standard and is unnecessary since under the
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Part 503 standards MH units are attaining significantly lower CO levels even though they are for
the most part conforming to a THC standard. The commenter (77.1) stated that 40 CFR Section
503.44 establishes a total hydrocarbon (THC) emission limit for all existing and new SSIs of 100
ppm (v/v) corrected to 7% C>2 and 0% moisture; and a subsequent amendment to 40 CFR Section
503.44 permitted the measurement of CO as an alternative to THC and the CO limit was
established at 100 ppm (v/v) corrected to 7% 02 and 0% moisture. The commenter (77.1)
purported that while all FB incinerators could meet the more stringent CO standard and,
therefore, the THC limit as well, MH units being less efficient combustors could only comply
with the less stringent THC limit (meeting the THC limit never resulted in any MH unit
producing CO emissions more than a few hundred ppm). One commenter (134.1) also
recommended using the Part 503 THC standards. One commenter (56.1) contended that most
states limit Carbon Monoxide (CO) to 100 ppmvd at 7% O2, based on the Part 503 requirements.
The commenter (56.1) contended that regulation to the current 100 ppmvd at 7% O2 is
appropriate in view of the cost-effective technology available. Another commenter (145.1) also
suggested a CO limit of 100 ppmv (and the same for NOX), stating that while it may be possible
to have CO or NOX as low as the proposed standard, the other compound would be at a much
higher concentration level. Commenters (64.1) urged EPA to adopt lower carbon monoxide
emission standards for sewage sludge incinerators.
Response: The CO limits in the final rule are based on EPA's revised UPL methodology,
which is documented in the memorandum, "Revised MACT Floor Analysis for the Sewage
Sludge Incinerator Source Category" in the SSI docket (EPA-HQ-OAR-2009-0559). The revised
final CO emission limit for new FB units is 27 ppmvd and for new MH units is 52 ppmvd. The
revised and final CO limits for existing FB units is 64 ppmvd and for existing MH units is 3,800
ppmvd. For MH units, the UPL calculation includes information from several units with CO
emissions measured at greater than 1000 ppmv. These facilities complied with the part 503
alternative THC limit but had high CO concentrations. EPA is required to set limits for CO for
units regulated under Section 129 of the Clean Air Act, and is not allowed to use surrogate
compounds, such as THC.
Please refer to the MACT floor UPL calculation and EG and NSPS emissions limits
section of the preamble for a detailed description of how these limits were chosen. The final rule
also allows 24-hour block averages for CO CEMS (which are required at new sources), and 12-
hour block averages for operating parameters. The combination of revised emission limits and
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averaging times may address the commenters concerns regarding compliance with the CO
emission limits. EPA chose not to go beyond the floor due to increases in NOX and CO, cost, and
energy inputs. States have the option to set limits more stringent than the emission guidelines and
can set lower CO limits.
4.4 CDD/CDF
Comment: One commenter (129.1) suggested that the dioxin limit only be on a TEQ
basis in lieu of the proposed TEQ and 1MB basis. Another commenter (86.1) suggested the
dioxin limit only be on a TMB basis because the same test, EPA Reference Method 23, is used to
measure both TMB and TEQ; and the only difference is a mathematical calculation using TEQ
factors to convert the measured TMB values to TEQ values. The commenter (86.1) also
indicated that TEQ factors have changed over the years from the original 1989 I-TEQ to the
presently used 2005 World Health Organization Toxic Equivalence Factors, so setting a TEQ
standard represents a potentially moving target. The commenter (86.1) stated that two standards
are not required by Section 129 which lists "dioxins and dibenzofurans" only once and without
distinction between TMB and TEQ (Section 129(a)(4).) The commenter (86.1) argued that
MACT standards are based on emissions reductions at best performing units, i.e. are technology
based as opposed to health based. Another commenter (95.1) suggested that EPA allow facilities
to meet either the TEQ or TMB proposed standard but not both. One commenter (129.1)
provided results from a study that indicated the incinerators located at their WWTPs are reducers
of dioxins. The commenter provided emission estimates from the incinerators of 2.3 ng TEQ/dry
kg of sludge incinerated and compared these to the dioxins concentrations in the sludge (92 ng
TEQ/dry kg and 42 ng TEQ/dry kg).
Response: The final standards provide facilities the option to comply with either the
TEQ of TMB limits. This provides flexibility for sources to comply.
4.5 Opacity
Comment: One commenter (95.1) stated that EPA should drop the opacity standard. The
commenter (95.1) argued that opacity is listed in Section 129(a)(4) of the Clean Air Act, but
Congress included a parenthetical "as appropriate" for this substance giving EPA the option of
not setting numerical emission limits for opacity. The commenter (95.1) said there is no reason
for having both a PM and an opacity standard, especially at the PM levels proposed. At least one
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commenter (49.1) stated that opacity from MH incinerators should be considered from the
perspective of particulate emissions; the commenter cited research that revealed that submicron
particulates are emitted from the stack with the same wavelength as visible light, thus creating an
opacity issue.
Several commenters (111.1, 117.1) stated that the proposed zero percent (0%) opacity
limits are unrealistic. Two commenters (129.1, 134.1) stated that a continuous opacity limit of
zero percent (0%) is not achievable for existing fluidized bed incinerators and all new SSI units.
Two commenters (111.1, 117.1) expressed the concern that the opacity tests were too subjective,
stating that an inspector could easily inaccurately register a measurement greater than 0%. One
commenter (129.1) urged EPA to realize that the opacity reported during the Information
Collection Request testing was visually collected; and during cold weather, fluidized bed
incinerators may have white steam plumes, which would exceed the zero percent opacity limit.
The commenter (129.1) also stated that continuous opacity monitors will always report a value of
greater than 0%. Other commenters (134.1) argued that the equipment available for continuously
monitoring opacity in SSI exhaust gases is notoriously inaccurate and unreliable; and stated that
visual measurements are somewhat arbitrary at best. The commenter (134.1) stated that this
emission parameter is of limited usefulness from a regulatory perspective and that if all other
emission parameters, particularly PM, NOX, HC1 and SO2 are controlled to the proposed levels,
opacity will not be present to an objectionable or measurable degree. The commenter (134.1)
stated that from the perspective of opacity as it relates to ash handling systems, this is more
appropriately regulated as a fugitive dust emission than under the guise of opacity. Two
commenters (117.1, 134.1) recommended that the opacity limits for existing FB units and all
new SSI units be established at 10%, which are more attainable as a regulatory limit. Another
commenter (111.1) suggested the use of Method 22 over Method 9 to reduce the subjectivity of
the opacity tests.
Response: Instead of establishing opacity limits, the final rules include rigorous
requirements for establishing site-specific operating limits derived from the results of
performance testing. The rules also include a requirement that sources update those enforceable
operating limits with each repeated performance test. Re-establishing operating limits
periodically will assure that the monitoring will continue to indicate compliance with the PM
emissions limits. The rules also provide the source the option of apply CEMS to monitor directly
the pollutant of interest in lieu of parametric monitoring. We believe that continuous compliance
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with operating limits and periodic stack testing to verify the operating limits plus the CEMS
option will ensure that sources demonstrate continuous compliance with the PM emission limits
as effectively as would periodic or continuous monitoring of a broadly applicable opacity limit.
4.6 Exhaust Gas Concentration
Comment: One commenter (126.1) stated that the correction of exhaust gas
concentrations to 7% oxygen can be problematic during periods of normal sludge incineration
since the exhaust oxygen level is a function of the total amount of sludge and fuel combusted
within the SSI. The commenter (126.1) argued that at reduced feed rates, oxygen levels are
considerably elevated compared to those resulting from incinerating sludge at or near maximum
capacity of the SSI. The commenter (126.1) provided an example that when operated at or near
the maximum capacity of 2.0 DTPH their exhaust gas is about 12,000 dscfm at 6.7 percent
oxygen; whereas at normal incineration rates of 1.1 to 1.2 DTPH the volumetric exhaust flow is
similar, but the oxygen content is 11.6 percent.
Response: Concentrations are corrected to 7% 02 in order to standardize the pollutant
emissions. As the commenter notes, operating at different feed rates but maintaining similar flow
rates yields different oxygen levels. Varying the feed rate while maintaining the same flue gas
flow rate will yield different pollutant concentrations as well. In other words, a higher feed rate
will yield a lower O2 level but a higher pollutant concentration. The uncorrected concentrations
are not analogous because of the different feed rates and 62 levels, so concentrations must be
corrected to 7% 02 so that concentrations are comparable for both cases.
4.7 Other
Comment: Commenters (84.1, 119.1) argued EPA's SSI standards are especially weak
for cadmium, lead, PM, HC1, and 862 - the pollutants for which EPA has failed either to propose
beyond-the floor standards or to propose standards that will provide coincidental reductions. The
commenter stated that all of these pollutants have extremely serious adverse health effects. The
commenter contended that EPA neglects not only its legal obligations but the health of American
communities by allowing SSI to continue emitting these pollutants without reducing them by the
maximum achievable degree.
Response: EPA disagrees with these comments. We have analyzed the beyond the floor
control options for all pollutants and determined that it was not appropriate to require additional
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control given costs and other relevant factors. Please refer to the memorandum "Revised
Analysis of Beyond the Maximum Achievable Control Technology (MACT) Floor Controls for
Existing SSI Units" (EPA-HQ-OAR-2009-0559) for further information.
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5.0 FORMAT OF THE PROPOSED STANDARDS AND GUIDELINES
Comment: Several commenters (126.1, 134.1, 101.1) were of the opinion that EPA erred
in setting the standards on an emission concentration basis with regard to the variability in the
pollutant loading in the sludge incinerated during the emission tests used by EPA to establish the
limits. One commenter (134.1) stated that the use of concentration limits, rather than control
efficiencies or total daily mass emissions, is not appropriate for certain regulated pollutants as
concentration limits do not reflect the unique feed conditions present in each SSI unit and may
unfairly penalize units with very low or very high feed concentrations of certain pollutants, such
as mercury, cadmium, or lead. The commenter (134.1) purported that units with very high feed
concentrations may not be able to comply with the proposed limits, as the requisite control
efficiency needed for compliance may be unattainable. The commenter (134.1) stated that the
EPA 503 regulations took these differences into account for many of the regulated metals and
created emission limits based on control efficiencies, coupled with feed concentration limits, to
provide adequate protection of health and the environment. The commenter (134.1)
recommended that consideration be given to establishing limits based on a similar approach and
allowing a calculation method to be available as a substitute for annual testing or CEMS
monitoring to demonstrate unit compliance.
Other commenters (126.1, 65.1, 101.1) stated that the data used to generate the MACT
standards should measure the performance of the actual air pollution control technology.
Commenters (126.1, 65.1, 101.1) noted that since the proposed rule specifies an emission
concentration limit, using the same control device on incinerators burning sludge with larger
inlet concentrations will likely result in higher than the proposed emission rates. Specifically,
some commenters (105.1, 137.1) stated that the methodology used in developing the proposed
standards did not take into account that Hg, Cd, Pb, HC1 and SO2 emissions are a function of the
sludge content and that the concentrations of these compounds in the sludge varies significantly
between facilities and over time. The commenters (105.1, 137.1) stated that basing the standards
on the lowest emitting sources is not appropriate or justifiable if the best test results were
obtained with a sludge containing very low concentrations of metals, Cl, and S. Commenters
(137.1) noted that the same metals emission rate could be unattainable by another facility, even if
it has more advanced controls and removes a higher percentage of the metal.
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One commenter (134.1) specifically suggested that the proposed limits for SC>2 be more
appropriately expressed as a control efficiency to allow for those units with high sulfur content in
the feed. The commenter (134.1) stated that the proposed limits for 862 are extremely low, given
that a typical feed contains 1-2% (but sometimes as high as 5%) sulfur; translating to an
uncontrolled SC>2 concentration on the order of 1,000 ppm or more prior to scrubbing. The
commenter (134.1) suggested that the selection of the best performing 12% of units be based on
removal efficiency and sulfur content in the feed, not just reported final emissions, as emissions
alone do not necessarily reflect good performance. The commenter (134.1) also stated that it is
not unreasonable for the proposed HC1 emissions limit on existing units be expressed in a
concentration format since chlorine content in the feed is typically low and not subject to a large
variation; however, the commenter thought an emission rate expressed in pounds per ton of feed
would be more appropriate. The commenter (134.1) suggested that the proposed limits for new
units be based either on control efficiency or a mass per unit feed processed in order to account
for potential differences in feed characteristics.
Similarly, other commenters (129.1) stated that the proposed rule's change to emission
limits in milligrams per dry standard cubic meter @7% oxygen and ppmvd @ 7% oxygen will be
a major change for the industry. The commenter (129.1) stated that POTWs are currently subject
to emission limits that are in pound (pollutant) per dry ton of sludge incinerated. Two
commenters (101.1, 126.1) specifically stated that emission standards set as pollutant
concentrations corrected to 7% oxygen may be appropriate for some air contaminants such as
CO and SO2, where CEMS are utilized for compliance monitoring (when charging sludge feed),
but a mass emission limit that accounts for the sludge incineration rate similar to the Subpart O
PM limit of 1.3 Ib/DT is preferred for most air contaminants.
Another commenter (135.1) stated that EPA must consider that concentration limits may
not be appropriate for facilities where efficiency improvements were made. In particular, the
commenter (135.1) mentioned that a number of SSI have invested significant money making
improvements to their process to improve performance and reduce mercury emissions, including
improvements that resulted in a reduction in the flue gas volume, thereby increasing flue gas
concentration of mercury without increasing the mass of mercury being emitted (for example,
flue gas recirculation in MH furnaces and increasing the sludge solids will both reduce flue gas
volume while not altering the mass of mercury being emitted). The commenter (135.1) is
concerned that the higher mercury concentration in the flue gas of these facilities will require
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higher control efficiency than anticipated by EPA to achieve the concentration based standard.
The commenter (135.1) argued that EPA is penalizing these facilities for historical actions that
reduced emissions.
Other commenters (137.1, 105.1, 80.1) argued that the standards should be established to
provide for compliance with either a concentration limit or a percent reduction, whichever is less
stringent, similar to other regulations such as the Municipal Waste Combustor (MWC)
regulations.
Response: EPA did not have sufficient data to set alternative control efficiency standards
or standards in other units at proposal. We requested additional information in the proposal.
However, sufficient data were not provided in response to our request for alternative formats to
be developed. See Section V of the preamble to the final SSI rules for additional discussion.
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6.0 SELECTION OF SUBCATEGORIES
Comment: Numerous commenters (58, 61.1, 63.1, 68.1, 69.1, 74.1, 78.1, 81.1, 87.1,
90.1, 94.1, 97.1, 127.1, 102.1, 105.1, 106.1, 107.1, 109.1, 110.1, 112.1, 114.1, 116.1, 117.1,
118.1, 126.1, 120.1, 129.1, 132.1, 134.1, 136.1, 101.1,85.1, 115.1,138) agreed with EPA's
development of separate emission guidelines for existing MH and FB SSIs. One commenter
(129.1) stated that only MH and FB incinerators are currently being utilized at POTWs to
incinerate sewage sludge. However, most of these commenters (58, 61.1, 63.1, 68.1, 69.1, 74.1,
78.1, 81.1, 87.1, 90.1, 94.1, 102.1, 105.1, 106.1, 107.1, 109.1, 112.1, 114.1, 116.1, 117.1, 118.1,
120.1, 129.1, 132.1, 136.1,97.1, 127.1, 115.1) suggested adding sub-categorization based on a
number of parameters, such as the size of the SSI, the type of sewage sludge incinerated, limited
use of the SSI, and/or the distance over which a utility would need to transport its sludge for
disposal. One commenter (115.1) recommended EPA establish some types of subcategories for
new or food-processing SSI sources. The commenter (115.1) included reference material
comparing their sewage sludge metals concentrations to results of other studies. Another
commenter (132.1) specifically requested that EPA add a subcategory that recognizes differences
between wet and dry treatment systems. The commenter (132.1) is concerned that moisture
content and other issues such as back pressure would prohibit a wet system such as theirs to
install a fabric filtration system due to technical infeasibility of the facility itself and current
equipment configuration.
Response: EPA is not subcategorizing SSI units on any basis other than the distinction
between FB and MH units because EPA does not have information demonstrating any other
distinctions among SSI units based on class, type, or size.
Comment: Numerous commenters (58, 61.1, 63.1, 68.1, 69.1, 74.1, 78.1, 81.1, 87.1,
90.1, 94.1, 102.1, 105.1, 106.1, 107.1, 109.1, 112.1, 114.1, 116.1, 117.1, 118.1, 120.1, 126.1,
129.1, 136.1, 65.1, 101.1) as well as others expressed that it is inappropriate to consider the best
performing FB SSIs as the best performing similar source for the MH SSI new source
subcategory; and many stated that as proposed, the new source performance standards would
severely restrict a POTW's ability to modify existing MH incinerators, including modifications to
improve combustion efficiency or boost steam output for electricity generation. Specifically,
commenters (95.1, 76.1) rejected EPA's proposal to establish emission limits for new MH
incinerators at the same level as for new FB incinerators. Commenters (76.1) argued that MH
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and FB SSIs are separate subcategories and therefore, new MH SSIs should not have to meet the
best performing FB SSI standard. One of these commenters (95.1) stated that to establish the
same emission limits for more than one subcategory is equivalent to expanding the data pool
outside the top performers. Another commenter (97.1 and 127.1) stated that EPA is essentially
setting a beyond-the-floor MACT limit for MH SSIs without considering any of the criteria that
the statute requires. Commenters (95.1, 76.1) contended that the Section 129 MACT
requirements do not exclude using the best performing MH unit simply because it is 20 years
old; the commenters (76.1) stated that EPA must develop a separate set of standards for the best
performing MH SSI regardless of the age because there is no statutory limit on the age of the
MH SSI that is the best performing. One commenter (122) noted that their MH incinerator was
less than 20 years old, contrary to language in the proposed rule that stated EPA is unaware of
any new MH sources constructed in the last 20 years. Several commenters (110.1, 76.1)
expressed concern that sources would need to make burdensome modifications to existing MH
units in order to meet the standards for new sources (based on the best-performing FBI).
Commenters (85.1, 97.1, 127.1, 90.1) further argued that EPA's proposed approach would
discourage incremental improvements at MH SSI because these improvements would trigger FB-
based emission limits that cannot be met. One commenter (110.1) was of the opinion that the
proposed standards would force sources to abandon the use of MH incinerators because the
standards are unachievable by MHs.
Multiple commenters (95.1, 76.1) requested that EPA establish separate limits for the
new MH and FB subcategories, using the best performing MH incinerator to set the emission
limits for new MH incinerators. These commenters (85.1, 97.1, 127.1) stated that establishing
separate emission limits for new MH and FB SSIs would also preserve incentives for innovation
and for improvements in the operation of MH SSI currently in use.
Conversely, one commenter (77.1) agreed with the EPA proposal that the best performing
FB SSI serve as the best performance similar source for the MH SSI new source subcategory.
The commenter (77.1) stated that in spite of the CAA provision that allows for sub-
categorization of combustion units, all sewage sludge units should be required to operate at the
FB level of performance. The commenter (77.1) said MH units were originally designed to be
ore roasters in metallurgical processes and not designed to be efficient solid waste combustors.
One commenter (49.1) stated that EPA should not allow new multiple hearth (MH) incinerators,
and should establish fluidized bed (FB) incinerators as the baseline for new units. The
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commenter (49.1) argued that FB incinerators have advantages such as electrostatic precipitators,
high solids centrifuges, and water sprays which were not available on MH incinerators built prior
to the mid 1980's. Another commenter (79.1) said that while sub-categorization for existing
sources for MH and FB SSIs may make sense, given the lack of newer MH SSIs, it does not
seem to make sense to create a subcategory for that technology in the new source standard.
Another commenter (80.1) asked that one set of emissions limits be set for both MH and FB SSIs
as a means of fairness, recognizing that the same emissions limits are equally protective of health
and the environment.
Response: In the final NSPS, SSI units at new sources are subcategorized into two
subcategories: MH and FB. Please see Sections IV and V of the preamble to the final SSI rules.
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7.0 TITLE V PERMIT REQUIREMENTS
Comment: Several commenters (63.1, 62.1, 80.1, 83.1, 121.1, 129.1, 135.1, 102.1,
116.1) are concerned about the proposed regulation requiring facilities to comply with Title V
requirements. Many of these commenters (63.1, 62.1, 80.1, 83.1, 121.1, 102.1, 116.1) said the
Title V requirements will impose further expense and/or paperwork. One commenter (80.1)
requested EPA specifically consider dropping the requirement for a Title V Operating Permit for
a minor source because a facility with a minor source air permit can still update that minor
source permit to include the appropriate emission limitations, as well as stack testing, monitoring
and reporting requirements. The commenter (80.1) is concerned that the facility would then be
subject to any future major source MACT regulations, adding other potential costs, even though
it is a minor source. Another commenter (121.1) argued that Title V reporting requirements are
unnecessary because the reporting is already required under 40 CFR Part 503, 40 CFR Part 60,
and other air permits. Another commenter (129.1) stated that they currently have three POTW
facilities that practice incineration including a Title V facility, a synthetic minor facility, and a
naturally minor facility. The commenter (129.1) is concerned that, under the proposed rules, two
of these facilities would become Title V facilities. The commenter (129.1) pointed out that even
though their naturally minor facility emits less than six (6) tons of priority pollutants per year,
the proposed rule would make it a Title V facility. Another commenter (135.1) stated that many
of the SSI impacted by this NSPS are minor sources of air emissions and requiring the additional
regulatory burden in states with delegation of NSPS programs seems unreasonable for minor
sources of air emissions. The commenter (135.1) pointed out that several state regulatory
programs have been rigorous, requiring the application of BACT or LAER for each pollutant that
a SSI had the potential to emit, as well as a demonstration of compliance with air toxics
programs to ensure human health was protected. Also, a commenter (102.1, 116.1) is concerned
that EPA gave no explanation for the proposed regulation requiring facilities to comply with
Title V requirements. The commenter (102.1, 116.1) expressed that there is no apparent need and
EPA gave no regard for the fact that many facilities been previously authorized under Synthetic
Minor status by their respective states and EPA.
Response: All nonmajor (minor) solid waste incinerators subject to the final sewage
sludge incinerator rule are subject to the requirement to obtain a title V permit under sections
129(e) and 502(a) of the CAA. See Section III.H. of the proposed preamble entitled "Title V
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Permit Requirements" for additional discussion relative to these requirements. The requirement
for a solid waste incinerator to obtain a title V permit does not vary based on whether the source
in question is a major or nonmajor source, although a source's major/nonmajor status does
impact when a source applies for a title V permit.
Additionally, an applicability determination under section 112 of the CAA is an
applicability determination that is separate from a section 129 applicability determination.
Comment: One commenter (92.1, 104.1) pointed out that 60.5235(c) specifies an Annual
Compliance Report requirement for SSI units subject to the proposed rule, but then adds a
statement regarding whether the unit is subject to permitting requirements under title V of the
Clean Air Act. The commenter (92.1, 104.1) stated that under 60.5240 and 60.5245 the unit is
always subject to permitting requirements under Title V; and therefore, the "if statement is
unnecessary. The commenter recommended that EPA change the note text in 60.5235(c) to say
"(You may be required to submit these reports more frequently by the Title V operating permit
required under 60.5240)."
Response: We agree with the commenter and have made this change, as well as added
that the additional reports that may be required by a title V permit may include additional
compliance information. We have also made these changes to paragraph 60.4915(d), except in
this paragraph we will reference section 60.4920 of the NSPS instead of 60.5240 of the EG.
Comment: One commenter (89.1) asked whether EPA calculated the increased economic
and resource burden to those facilities that must now be fully regulated under EPA's Title V
Operating Permit Program as a result of the Proposed Standards. The commenter (89.1) requests
that EPA provide this information.
Response: Costs associated with permitting SSI facilities are covered under information
collection requests for 40 CFR parts 70 and 71, which have been approved by the Office of
Management and Budget.
Comment: One commenter (130.1) recommended EPA consider regulations that require
basic protections of any Tribal land and resources considered culturally important to Tribes. The
commenter (130.1) suggested that having SSI units obtain Title V permits may trigger Tribal
consultation with regard to potential impacts from the SSI unit. The commenter (130.1) stated
that risks associated with air emissions must be addressed accordingly through enforceable
federal safeguards so as to protect the health and welfare of Indian Tribes across the nation.
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Response: Our consultation with Indian tribes is addressed in section VIII.F. of the
proposed preamble.
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8.0 BASELINE EMISSIONS ESTIMATES
8.1 Baseline Emissions Overstated
Comment: Numerous commenters (81.1, 58, 67.1, 75.1, 87.1, 93.1, 94.1, 96.1, 103.1,
106.1, 107.1, 109.1, 111.1, 113.1, 117.1, 121.1, 87.1, 138, 58, 67.1, 68.1, 69.1, 70.1, 71.1, 72.1,
74.1, 75.1, 76.1, 81.1, 83.1, 94.1, 96.1, 129.1, 97.1, 127.1, 101.1, 102.1, 103.1, 105.1, 106.1,
107.1, 108.1, 109.1, 110.1, 111.1, 112.1, 113.1, 114.1, 115.1, 116.1, 117.1, 120.1, 121.1, 126.1,
129.1, 131.1, 132.1, 134.1, 136.1, 102.1, 116.1, 138, 145.1,76.1, 129.1) stated EPA over
estimated baseline emissions of several pollutants for their facility. Commenters (81.1, 58, 67.1,
87.1, 138, 67.1, 72.1, 76.1, 81.1, 96.1, 97.1, 127.1, 80.1, 93.1, 101.1, 103.1, 105.1, 110.1, 111.1,
112.1, 113.1, 114.1, 115.1 117.1, 120.1, 121.1, 126.1, 129.1, 134.1, 76.2, 138, 145.1, 76.1,
129.1) provided or claimed recent stack test data and emission estimates support their argument.
Commenters provided several reasons for emissions: incorrect air flow rate parameters were
assigned to units (67.1, 121.1); incorrect collection and removal efficiencies were applied to
control technologies (75.1, 107.1, 75.1, 129.1); an incorrect number of units was used in the
baseline calculations (87.1, 109.1, 138,97.1, 127.1, 112.1); EPA used an incorrect sludge feed
rate(106.1, 111.1, 121.1,83.1,90.1, 121.1); and EPA used an incorrect annual SSI run time
(93.1, 94.1, 101.1, 97.1, 127.1, 102.1, 116.1).
Numerous commenters (68.1, 76.1, 85.1, 105.1, 110.1, 129.1, 134.1) noted that EPA used
uncorrected flue gas flow rates and flow rate factors with pollutant concentrations corrected to
7% 62, resulting in an overestimation of baseline emissions. One commenter (76.1) stated that
ERG used pollutant concentration data corrected to 7% O2 and multiplied by the actual stack gas
flow rate which was not corrected to 7% 02, severely over-estimating the annual mass emission
rate. A number of commenters (76.1, 97.1, 127.1, 102.1, 116.1, 85.1) stated EPA used incorrect
sludge feed rate factors. Two commenters suggested EPA use a factor incorporating sludge
produced per capita basis (76.1). Other commenters (129.1, 85.1) claimed thatEPA's airflow
rate factors (129.1, 85.1) were incorrect. A commenter (76.1) stated that a 75% capacity
utilization factor was not appropriate and that EPA must allow for 100% utilization of assets
citizens have paid for to meet future capacity needs. However, another commenter (97.1, 127.1)
pointed out that operating conditions for POTW and their incinerators are significantly below the
design capacity to handle the large swings in influent flow rate due to wet weather events and by
assuming a 75% capacity factor, emissions were overstated. One commenter (76.1) stated that
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EPA should use available population data to insure the default factors are appropriate for the
units in questions. Another commenter (71.1) argued that the rule has been rushed, adding there
was little data to support the proposed rule and little time for a formal information collection
request by EPA. The commenter (71.1) added to save time, EPA has used assumptions and other
factors from other rules for units that have no similarity to SSIs and that burn wastes that are not
similar to sewage sludge resulting in overestimation of emissions. Another commenter (138)
stated that EPA made a number of incorrect assumptions concerning the operations of sewage
sludge incinerators that resulted in a substantial overestimation of the quantity of sewage sludge
being incinerated in the United States, the current baseline emissions, and the potential reduction
emissions due to implementation of emission guidelines. One commenter (91.1) stated that
because of overestimation of emissions, the need for additional controls from SSIs as a whole
has been overstated. At least two commenters (97.1, 127.1, 129.1) noted that errors existed in the
dataset that are an indication of inadequate quality assurance and quality control on the data in
the database; the commenters (97.1, 127.1) requested that EPA perform a rigorous quality
assessment of the data prior to setting standards.
Response: EPA has incorporated corrections to the inventory and calculation inputs
provided by the commenters where applicable. EPA has also revised the calculation of baseline
emissions by revising the defaults assigned to SSI units where information was not available.
Defaults were necessary to be assigned because, even after new data were received in comments,
a significant number of units did not have data on sludge capacity, flue gas flow rates, etc.
Several default parameters are based on available service area population data. A detailed
description of the methodology used to fill data gaps is presented in the memorandum "Post-
Proposal SSI Database Revisions and Data Gap Filling Methodology" (EPA-HQ-OAR-2009-
0559). A detailed discussion of the methodology used to estimate baseline emissions for the final
standards is presented in the memorandum "Revised Estimation of Baseline Emissions from
Existing Sewage Sludge Incineration Units"(EPA-HQ-OAR-2009-0559). To address the issue of
capacity vs actual feed rates, an upper and lower bound for each pollutant was calculated. The
upper bound represents an estimation of potential emissions if the sludge feed rate was at the dry
sludge capacity of each unit. EPA estimated the potential emissions because the amount of
wastewater treated (and sludge produced) may vary significantly based on changes in population
or sources of wastewater. Facilities have the potential to burn up to their units permitted capacity
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although they may not be doing so currently. The lower bound represents an estimation of
emissions based on sludge feed rates, rather than sludge capacity.
Comment: Several commenters (106.1, 58, 61.1, 63.1, 67.1, 68.1, 69.1, 70.1, 71.1, 73.1,
74.1, 75.1, 78.1, 81.1, 83.1, 87.1, 90.1, 94.1, 97.1, 127.1, 101.1, 102.1, 103.1, 105.1, 106.1,
107.1, 109.1, 110.1, 111.1, 112.1, 114.1, 115.1, 116.1, 118.1, 120.1, 126.1, 132.1, 136.1, 138)
stated mercury emissions had been estimated to be three times greater than a 1997 Mercury
Study Report to Congress provided by the Agency released before several mercury point sources
implemented measures to reduce the amount of mercury disposed of in wastewater. Other
commenters (75.1, 85.1, 97.1, 127.1, 110.1, 134.1, 138) referenced a report published in 2009 by
the Water Environment Research Foundation which stated SSIs collectively emit less than 1 ton
of mercury each year. A commenter (97.1, 127.1) argued EPA may have miscalculated the
mercury content of sewage sludge because the Agency's data are not representative of typical
mercury values. One (76.1) commenter contends that the mercury emissions data for multiple
hearth incinerators are overestimated by 77%, and stated that the baseline emission calculations
significantly increase the $6,150/lb mercury cost of compliance for the beyond-the-MACT-floor
mercury limit. Commenters (76.1, 134.1) noted EPA should recalculate or review the emissions
baselines, and commenters (76.1, 134.1) added EPA should adjust the beyond-the-MACT-floor
for mercury as warranted. A commenter (85.1) argued that based on EPA's errors in estimated
baseline emissions, EPA must re-evaluate baseline emissions, the MACT floor assessment, and
the beyond the floor assessment.
Response: EPA has incorporated corrections to the inventory and calculation inputs
provided by the commenters where applicable. The corrections included using flowrates
corrected to 7% 02 for calculating baseline emissions. EPA has also revised the calculation of
baseline emissions by revising the defaults assigned to SSI units where information was not
available. Defaults were necessary to be assigned because, even after new data were received in
comments, a significant number of units did not have data on sludge capacity, flue gas flow
rates, etc. A detailed discussion of the methodology used to estimate baseline emissions for the
final standards is presented in the memorandum "Revised Estimation of Baseline Emissions from
Existing Sewage Sludge Incineration Units"(EPA-HQ-OAR-2009-0559). The revised mercury
baseline emissions estimates range from 0.9 to 1.2 tons per year. The upper bound represents an
estimation of potential emissions if the sludge feed rate was at the dry sludge capacity of each
unit. We estimated the potential emissions because the amount of wastewater treated (and sludge
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produced) may vary significantly based on changes in population or sources of wastewater.
Facilities have the potential to burn up to their units permitted capacity although they may not be
doing so currently. The MACT floor and beyond-the-floor assessments have also been revised,
as appropriate, base on this revised data. Please see the memoranda "Revised Cost and Emission
Reduction of the MACT Floor Level of Control" and "Revised Analysis of Beyond the
Maximum Achievable Control Technology (MACT) Floor Controls for Existing SSI Units"
(EPA-HQ-OAR-2009-0559) for further detail. For the final rule we have decided select the
MACT floor emission limits for all pollutants.
8.2 Comments on CO baseline emissions
Comment: At least one commenter (145.1) stated that the CO concentrations assigned to
MH incinerators with afterburners is incorrect. The commenter (145.1) noted that a reduction
efficiency was not assigned to MH incinerators with afterburners because data were not available
to determine a percent reduction value. The commenter (145.1) argues that the low CO emissions
levels achieved by MH incinerators equipped with afterburners or RTOs have not been
considered in the best performing 12% of the units. The commenter (145.1) notes that the CO
emissions assigned to the MH incinerators equipped with detached afterburners or RTOs have
the same CO emission level of the rest of the MH incinerators; hence, all the MH incinerators
can meet the best performing 12% MH incinerators without requiring any improvements. The
commenter (145.1) states that the CO emissions from the detached afterburners or RTOs should
be established and included in the determination of the 12% best performing MH incinerators for
CO emissions.
Response: The MACT floor limit for CO was based only on actual emissions data
collected. The MACT floor includes CO emissions data from the best-performing 12 percent of
sources in each subcategory. To estimate baseline emissions, EPA had to make assumptions to
fill in gaps for the units having no data. A detailed discussion of the methodology used to
estimate baseline emissions for the final standards is presented in the memorandum "Revised
Estimation of Baseline Emissions from Existing Sewage Sludge Incineration Units"(EPA-HQ-
OAR-2009-0559).
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8.3 Uncontrolled Emissions are Incorrect
Comment: A commenter (145.1) stated the Table 3-2 in the June 2010 memorandum
from ERG to EPA titled "Emission of Baseline Emissions from Existing Sewage Sludge
Incineration Units" cannot be correct. The commenter (145.1) stated that, in FB incinerators,
unless they are equipped with waste heat boilers, all the ash from burning of sludge and a small
part of bed material (usually silica) is elutriated from the incinerators. The commenter (145.1)
added that most of the FB incinerators are hot-windbox design and equipped with air preheaters
(heat exchangers). The commenter (145.1) noted that because the preheaters used for FB
incinerators are designed not to capture any bottom ash, all of the ash is exhausted into the wet
scrubbers as uncontrolled emissions. In MH incinerators, only 10% to 20% of ash is carried
away with flue gases, and the remaining 80% to 90% is discharged as bottom-ash. Therefore, the
commenter (145.1) asserted, the uncontrolled PM concentration in flue gases from the MH
incinerator would be about 20% of the concentrations found in the FB incinerators. The
commenter (145.1) stated that in Table 5 (Ref EPA-HQ-OAR-0559-2009-0145.1 "Uncontrolled
Emissions"), the emission data used in the development of the MACT standards is partially
represented. The commenter (145.1) stated that although the use of higher excess air in MH
compared to FB incinerators dilutes the metal concentrations for some amount, the ratio of the
FB-to-MH uncontrolled emission ratio should be about 100/20 or 5. The commenter compares
this to Table 3-2 in the referenced EPA document, where this ratio is 249/722 or 0.3.A similar
argument can be made for the Cd, Pb and Hg emissions. The commenter questioned why the
average uncontrolled emission for Cd from the MH incinerators is 21 times more than the
emissions from FB incinerators, and if the FB incinerators used in the database were located in
residential areas, or if MH furnaces were located in the industrial areas. The commenter asserted
that regardless of any possible explanation, the Average Uncontrolled Concentrations presented
in Table-3 cannot be correct.
Response: At proposal we estimated uncontrolled emissions simply as a means to
determine baseline emissions for units we did not have data on. We have modified our analysis
since proposal. Please refer to the memorandum "Revised Estimation of Baseline Emissions
from Existing Sewage Sludge Incineration Units"(EPA-HQ-OAR-2009-0559). For those sources
where we are still using this analysis, we maintain its appropriate to determine baseline
emissions if consistently applied while back-calculating to uncontrolled emissions, then forward
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calculating to baseline emissions. It has been used for other combustions sources and there's no
reason it should be different for SSI's.
8.4 Metals Content of Sludge
Comment: Several commenters provided sewage sludge metals content (80.1, 126.1,
105.1, 126.1, 132.1). Another commenter (97.1, 127.1) claimed EPA's mercury emissions
estimates for their facilities were nearly three times higher than the actual concentration of
mercury in their sludge in 2009. Commenters (105.1, 54.1, 60.1) indicated a decreasing trend in
the amount of mercury present in sewage sludge due to source reduction measures. Additionally,
a commenter (70.1) indicated that they have not discovered any measurable amount of mercury
within their influent, effluent or sludge and sampling continues to result in minute detectable
amounts in the parts per billion and mercury has played no major role in the emission from the
incinerator. Another commenter (132.1) stated that under their NPDES permit and Industrial
Pretreatment program from the State of Michigan, they monitored mercury in the wastewater
treatment plant effluent for 13 consecutive months and was exempted from the mercury
minimization program. In addition, the commenter (132.1) said they have been monitoring
mercury in sludge monthly in compliance with the current air permit as well as periodic stack
testing of air emissions. The commenter (132.1) provided their sludge metals data.
Response: EPA has revised our estimate of mercury emissions based on corrections
provided by commenters. A detailed discussion of the methodology used to estimate baseline
emissions for the final standards is presented in the memorandum "Revised Estimation of
Baseline Emissions from Existing Sewage Sludge Incineration Units"(EPA-HQ-OAR-2009-
0559).
8.5 EPA Missing Data
Comment: A commenter (83.1) claimed EPA recognized the need for additional data
such as utilized capacity, permitted capacity, air flow rate, and operational hours. The
commenter argued that it is unreasonable for EPA to move forward with its Proposed Rule when
it is missing this type of information. The commenter (83.1) also added that EPA has made a
number of data errors in its Proposed Rule and that EPA cannot possibly issue this rule in good
faith knowing its numbers are so skewed and any attempt to do so would violate the most basic
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principles of administrative process. [The commenter's supporting statements have been
accounted for in other comments/responses]
Response: EPA recognizes that with any rulemaking there will likely be data gaps. EPA
requested additional data to fill in data gaps and received some additional data along with some
data revisions during the comment period. We have incorporated corrections to the inventory and
calculation inputs provided by the commenters where applicable. In some cases, commenters did
not provide information sufficient for us to revise the inventory or calculation inputs for the
commenter's facility.
We have also revised the calculation of baseline emissions by revising the defaults
assigned to SSI units where information was not available. Defaults were necessary to be
assigned because, even after new data were received in comments, a significant number of units
did not have data on sludge capacity, flue gas flow rates, etc. A detailed discussion of the
methodology used to estimate baseline emissions for the final standards is presented in the
memorandum "Revised Estimation of Baseline Emissions from Existing Sewage Sludge
Incineration Units"(EPA-HQ-OAR-2009-0559).
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9.0 FACILITY/UNIT SPECIFIC INFORMATION AND DATA
CORRECTIONS
9.1 General Facility Information
Comment: Several commenters (58, 61.1, 63.1, 67.1, 68.1, 69.1, 70.1, 71.1, 74.1, 75.1,
76.1, 78.1, 81.1, 85.1, 87.1, 90.1, 93.1, 94.1, 96.1, 101.1, 103.1, 105.1, 106.1, 107.1, 109.1,
111.1, 112.1, 113.1, 114.1, 115.1, 117.1, 118.1, 120.1, 121.1, 126.1, 129.1, 132.1, 138, 72.1)
provided EPA with information regarding the population served and the amount of wastewater
received by their wastewater treatment facilities and SSIs. Many commenters noted annual tons
of sewage sludge incinerated (58, 61.1, 63.1, 67.1, 68.1, 69.1, 70.1, 74.1, 81.1, 85.1, 87.1, 93.1,
94.1, 101.1, 103.1, 105.1, 106.1, 107.1, 109.1, 111.1, 112.1, 113.1, 114.1, 115.1, 117.1, 118.1,
120.1, 121.1, 126.1, 129.1, 132.1), hourly incineration rates (61.1,62.1,67.1,69.1,71.1,74.1,
76.1,80.1,93.1,97.1, 127.1, 117.1, 121.1, 129.1, 138, 112.1), incinerator capacity (61.1, 62.1,
67.1,71.1, 117.1, 129.1, 109.1), the number and type of incinerators at their facilities (58, 61.1,
62.1, 63.1, 67.1, 68.1, 69.1, 70.1, 71.1, 73.1, 75.1, 76.1, 80.1, 81.1, 85.1, 87.1, 93.1, 94.1, 94.1,
52.15, 101.1, 103.1, 105.1, 106.1, 107.1, 109.1, 111.1, 112.1, 113.1, 114.1, 115.1, 117.1, 118.1,
120.1, 121.1, 122, 126.1, 129.1, 132.1,94.1, 138, 144), the exhaust gas parameters (61.1, 62.1,
67.1,74.1,76.1, 117.1, 121.1, 132.1, 112.1, 109.1) and associated control equipment (61.1, 73.1,
75.1, 101.1, 118.1, 121.1, 122, 126.1, 144, 129.1). Commenters also provided typical annual
operating hours (61.1, 62.1, 71.1, 74.1, 93.1, 94.1, 97.1, 127.1, 117.1, 129.1, 109.1) and ash-
handling information (61.1, 67.1, 76.1, 138). A small number of commenters provided annual
cost estimates (71.1) and fuel usage (76.1, 138) for their current sewage sludge incineration.
Numerous commenters (48.1, 61.1, 68.1, 80.1, 81.1, 85.1, 105.1, 120.1) noted recent or planned
upgrades to their wastewater treatment facilities and sewage sludge solids handling equipment.
Response: All additional data concerning operating parameters or unit or facility
characteristics were incorporated where applicable into a revised data set. A more detailed
description of the revised data and how it was used in filling the data gaps for subsequent
analyses can be found in the memorandum "Post-Proposal SSI Database Revisions and Data Gap
Filling Methodology"(EPA-HQ-OAR-2009-0559).
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9.2 Heat Recovery and SSI Units
Comment: One commenter (73.1) noted heat recovery units had been installed on their
SSI units. The commenter (73.1) noted that the heat recovery systems provide heat or electricity
in excess of the SSI units' needs and the heat or electricity can be utilized by the WWTP or
surrounding community. Two commenters (76.1, 138) also noted a heat recovery unit installed
on their SSI unit and that the captured energy was used within the wastewater treatment process.
Response: This data was not required for any of our analyses and was therefore not
extracted into the database.
9.3 Incineration for Other WWTP
Comment: Several commenters (61.1, 68.1, 73.1, 101.1, 105.1, 126.1) stated they
provide incineration for numerous other wastewater facilities in proximity to their SSI unit.
Response: EPA thanks the commenter for their input.
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10.0 MACT FLOOR DETERMINATION METHODOLOGY
10.1 Feed Operational Variability has not been taken into Account
Comment: Several commenters (97.1, 127.1, 80.1, 67.1, 108.1, 138, 137.1) claimed that
emissions variability has not been appropriately accounted for in developing the proposed
standards. Many commenters (97.1, 127.1, 108.1,73.1, 137.1, 134.1) stated that EPA has not
considered differences in feed characteristics in developing the standards for new incinerators.
Other commenters (85.1, 97.1, 127.1, 105.1, 134.1) noted that sludge variability, operational
variances, and seasonal temperatures were not factored into the criteria for developing standards.
One commenter (85.1) noted that, given these variables, the same unit may not meet the limit in
future tests.
Several commenters (84.1, 119.1,97.1, 127.1, 105.1, 129.1, 134.1) rejected EPAs
determination that variations in the waste of SSIs are not as great as the variations in waste
burned by other incinerators and is a homogenous mixture. One commenter (97.1, 127.1) stated
that unlike other types of industrial and commercial incinerators, many different entities and
individuals have unlimited access to the POTW through thousands of toilets, sinks and drains
that flow into the treatment works, resulting in highly variable and often unpredictable spikes in
concentrations in the waste stream. Additionally, the commenter (97.1, 127.1) noted that POTW
inlet concentrations vary based on the nature and type of dischargers and significant regional and
seasonal variability that is not captured by EPA's dataset. The commenter (97.1, 127.1) stated
that without the use of long-term data, this variability makes numeric technology-based limits
impractical and infeasible. Commenters (105.1, 137.1) noted that many facilities receive a range
of materials for combustion including primary sludge, waste activated sludge, digested sludge,
septage, grease trap pumpings, grease skimmed from headworks and primary system.
Furthermore, the percentage of each of these streams in the overall stream varies over the
seasons as well as throughout the day. The commenters (105.1, 137.1) noted that these materials
have very different heat contents, are present at widely varying concentrations in the overall
sludge over time, and can separate in storage, further affecting SSI feed characteristics. Other
commenters (97.1, 127.1, 134.1) stated that different treatment methodologies result in chemical
and biological differences in the composition of sewage solids that must be considered.
Some commenters (97.1, 127.1, 134.1) stated concerns regarding the variable
composition of biosolids. Several commenters (80.1, 97.1, 125, 127.1, 145.1, 67.1, 105.1) noted
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that metals (including mercury, cadmium, and lead), chloride, and sulfur concentrations may
vary based on sludge characteristics and should be taken into consideration when setting
standards. Specifically, some commenters (97.1, 127.1, 145.1) claimed that the sludges produced
at the wastewater plants located in the industrial areas have higher concentration of certain
pollutants (e.g., Cd, Pb, Cr, Ni) than the sludges generated in the plants located in the residential
areas. At least one commenter (145.1) provided publications to substantiate this claim. Another
commenter (97.1, 127.1) provided monthly average sewage sludge content of cadmium, lead,
and mercury at two of its POTW facilities to assert that the range of average metal
concentrations may vary by a factor of three or more. The commenter (97.1, 127.1) was of the
opinion that other POTWs face similar variability at this level or greater and that a similar degree
of variability applies to other constituents as well. Two commenters (105.1, 137.1) stated that the
inlet metals content can vary over time by over an order of magnitude within a single POTW as
well as among different POTWs, based on the industries discharging to the POTW. The
commenters (105.1, 137.1) provided data for metal concentrations land application system
surveys done in Maine, New York, Pennsylvania and Vermont. One commenter (134.1)
referenced a January 2009 EPA report, "Targeted National Sewage Sludge Survey Statistical
Analysis Report", specifically stating that there is a large variability in the level of mercury in
biosolids. The commenter (134.1) noted that a large number of samples are required to
characterize both the level of mercury and the potential variability in the feed stock (which
provides the design criteria for the selected air pollution control equipment). Some commenters
(105.1, 137.1) remarked that EPA did not consider the actual metals removal efficiency for the
SSIs in the proposed rule, and argued that the "best performing" SSI for metals may have been
based on a low metals inlet concentration instead of the removal of the metal by pollution control
equipment. One commenter (125) suggested EPA survey facilities for metal concentrations in the
incoming biosolids. The commenter (125) stated that metal concentrations for various waste
water treatment plants can vary for a region, as well as, for a specific facility, therefore the
emission standards for these metals requires some flexibility. The same commenter (125)
provided Southern California biosolids data showing concentrations that range from 1-20 mg/kg
for cadmium, 7-66 mg/kg for lead, and 1-6 mg/kg for mercury; and showed an example of how
facilities that encounter metal concentrations in the upper end range will face difficulty meeting
the proposed standard.
Response: Please refer to Section V.C of the preamble.
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Comment: One commenter (97.1, 127.1) stated that EPA could not use justify that
sewage sludge is homogeneous because the Part 503 regulations cap sludge concentrations. The
commenter (97.1, 127.1) stated that the Part 503 regulations do not address all of the Section 129
pollutants (PM, opacity, SC>2, HC1, NOxand dioxin/furans), and do not account for the variability
of sulfur, chlorine and nitrogen concentrations in sewage sludge, which have a direct effect on
the amount of SC>2, HC1, and NOX generated when the sludge is incinerated. The commenter
(97.1, 127.1) also noted that while Part 503 establishes risk-based limits for lead and cadmium,
these limits are different for every POTW based on feed rates, stack heights, and exhaust flow
rates and POTW performance varies significantly depending upon the sources of these
compounds in the sewage system. The commenter (97.1, 127.1) argued that the actual
performance for all POTWs is far below the health-based limits established under Part 503 and
may vary by a factor of 100 or more without approaching the Part 503 limit. Therefore, the
commenter (97.1, 127.1) asserted that EPA cannot rely on Part 503 standards as evidence of
homogeneity in waste streams.
Response: Please refer to Section V.C of the preamble..
Comment: Several commenters (97.1, 127.1, 108.1, 105.1, 137.1) stated that EPA could
not appropriately account for variability based on the limited number of performance tests in the
collected data; one commenter (105.1) asserted that while one or two performance tests may
account for the variability for a given feed composition or set of operating parameters, it cannot
account for the full range of expected feed compositions and operating parameters that a unit
may regularly encounter. At least one commenter (97.1, 127.1) suggested that EPA consider the
Part 503 metals data that POTWs submit to the Agency regularly to account for variability when
setting emission limits. The commenter (97.1, 127.1) noted that EPA has requested additional
sewage sludge metals content information, but has restricted its request to metals content
information collected during stack tests. The commenter (97.1, 127.1) noted that EPA must also
account for variability for the compounds not regulated by Part 503 prior to setting the new
source limit.
Response: Please refer to Section V.C of the preamble. A variability factor can only be
developed based on sources in the top 12 percent.
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10.2 Criticism's of EPA's Selection of Facilities for the MACT Floor
Comment: Several commenters (84.1, 119.1, 97.1, 127.1, 108.1, 107.1, 122, 123, 138,
145.1,95.1,65.1,79.1, 101.1, 109.1,76.1, 134.1) stated that EPA has not collected sufficient
data or followed the requirements of the Clean Air Act (CAA) in establishing the Maximum
Achievable Control Technology (MACT) floor for the SSI units. Multiple commenters (97.1,
127.1, 95.1, 79.1, 76.1, 110.1, 138) rejected EPA's selection method, stating the selection method
surveyed facilities in only nine municipalities. At least two commenters (97.1, 127.1, 102.1,
116.1) posed that EPA limited the ICR to nine entities because collecting information from ten or
more entities would have triggered a more rigorous OMB review; one of these commenters
(102.1, 116.1) stated that EPA actually selected 10 wastewater treatment plants (sources) for the
development of the Proposed Standard, and has therefore knowingly bypassed the OMB process.
Many commenters (84.1, 119.1, 97.1, 127.1, 79.1, 76.1, 134.1) suggested that the selection
method limited EPA to insufficient data to set the standards and that EPA incorrectly relied on
statistical techniques to utilize this data to set the MACT floor. At least two commenters (97.1,
127.1) specifically argued that by limiting the inventory to nine POTWs "expected to have the
lowest emissions based on the type of unit and the installed air pollution controls", EPA could
not reliably use a statistical analysis that presumes the data is a random sample representative of
the entire source category or subcategory. One commenter (97.1, 127.1) stated that due to the
selection method and insufficient data collection, EPA has created more stringent emission limits
that constitute "unlawful beyond-the-floor MACT standards".
Several commenters (97.1, 127.1,95.1,65.1,79.1,76.1, 102.1, 116.1, 111.1) specifically
criticized EPA's method of selection of the top 12 percent of units for each source category.
Many of these commenters (97.1, 127.1, 102.1, 116.1,95.1,79.1, 101.1, 76.1) were of the
opinion that EPA has not meet the requirements of the statute, which requires that MACT be no
"less stringent than the average emissions limitation achieved by the best performing twelve
percent of units in the category (excluding units which first met lowest achievable emissions
rates 18 months before the date such standards are proposed or 30 months before the date such
standards are promulgated, whichever is later)." Multiple commenters (84.1, 119.1, 97.1, 127.1,
102.1, 116.1,95.1,76.1, 126.1, 134.1) noted that EPA had data for less than 12 percent of the
best-performing sources in the source categories. Thus, several commenters (95.1, 109.1, 134.1)
asserted that EPA does not have the requisite data required by Section 7429(a)(2) to conduct a
legitimate MACT floor analysis. These commenters (84.1, 119.1, 95.1, 101.1, 76.1, 134.1) noted
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that several respondents did not provide emission data for all pollutants, and therefore EPA only
has actual emissions data from only five to 19 MH facilities (based on the pollutant). At least two
commenters (90.1, 138) noted that the proposed standards for new incinerators were based on a
very limited amount of air emissions test data obtained from only three POTWs utilizing
fluidized bed sewage sludge incinerators. One commenter (90.1) expressed concern that
calculating MACT floors on such a small sample size would result in future incinerators not
likely being able to meet the new standards even if operating as designed. Conversely, one
commenter (134.1) recommended that EPA use the performance from the three units in St. Paul,
MN as the floor for best unit technology; the commenter (134.1) remarked that these units have
the most data, have identical equipment, and have been tested at several times so that variations
in feed sludge may be observed. At least one commenter (76.1) requested justification that the
permit data used for 9 MH facilities to complete the inventory reflects the 12% best performing
units.
Other commenters (102.1, 116.1, 13 8, 95.1) stated that EPA has not justified that the
units selected accurately reflect the top 12 percent. One commenter (102.1, 116.1) asserted that
individual sources, not units, must be utilized; the commenter (102.1, 116.1) noted that the
composition of sludge varies greatly from source to source, therefore, utilizing multiple units at
one source skews the data for setting the MACT Standard. Another commenter (102.1, 116.1)
expressed concern that the two units utilized to set the baseline possess advanced technology and
control systems not utilized at any of the remaining top 12%.
Commenters (107.1, 79.1, 76.1) further stated that the agency's method does not
substitute for the more complete information the agency would have received from a more
thorough data-collection effort. Several commenters (85.1, 97.1, 127.1, 107.1, 65.1, 75.1, 79.1,
109.1, 76.1, 134.1) requested that the agency collect new data and recalculate the MACT floor.
At least one commenter (76.1) requested that EPA incorporate data that was submitted after the
ICR deadline into the MACT analysis process. Some commenters (129.1, 129.1) stated that they
could provide additional data for EPA. One commenter (132.1) suggested that because the
proposed standards are based on a limited data set of SSI units with advanced controls, the
standards should be considered "interim standards" and be finalized only after sufficient number
of facilities are built with advanced controls and data made available for EPA's use. Multiple
commenters (65.1, 79.1, 101.1, 76.1, 126.1) requested that EPA reanalyze the MACT floor based
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on a complete data set from each of the best-performing 12%, containing data for all nine of the
critical pollutants.
Response: Please see Section V.C of the preamble for EPA's response to these
comments.
Comment: Some commenters (84.1, 119.1, 79.1, 101.1, 76.1) claimed that EPA cannot
consider statistical analysis and control device performance to determine which sources would be
the "best-performing" units. Commenters (84.1, 119.1, 95.1) stated that the agency did not
provide a rational basis or demonstrate with substantial evidence that the selected units were the
best-performing units. Some commenters (84.1, 119.1, 95.1) argued that EPA may not set the
floors based solely on the performance of pollution control technology, citing Cement Kiln
Recycling Coalition v. EPA, 255 F.3d 855. 863 (D.C. Cir. 2001). One commenter (84.1, 119.1)
noted that several units that are not among those EPA identified as the best performers will not
have to install control technology or otherwise reduce their emissions because their emission
levels already are at or below the agency's floor levels. In addition, several commenters (84.1,
119.1, 97.1, 127.1, 95.1, 65.1) asserted that SSI emission levels are affected not only by control
technology but by other factors, including the contents of the sludge that a unit is burning, the
fuels they use, the age and design of the individual unit, the specific quality and age of the
control devices at individual units, the training and skill of the operators, and the care with which
they run individual units. One commenter (76.1) argued that EPA cannot ignore non-technology
factors that reduce HAP emissions, specifically citing that "EPA's decision to base floors
exclusively on technology even though non-technology factors affect emissions violates the Act"
(479 F. 3d at 883) and stating that EPA must consider upstream source control and waste
diversion when setting standards. Another commenter (95.1) referred to the Brick MACT case
(Sierra Club v: EPA, 479 F.3d 875, 884 (D.C. Cir 2007)), stating that although the Brick MACT
alludes to the Agency having to set MACT standards under Section 112 based on lowest
emissions, it did not require EPA to do so, and does not support developing floor standards based
on lowest emissions. At least one commenter (134.1) noted that selecting the best-performing
units on the basis of control devices that are "expected to have the lowest emissions" may not
capture the best performing units, as performance is influenced more by operating parameters
(some in the combustion system and some in the emissions control system) than on the particular
technology employed. Two commenters (124.1, 82.1) recommended that EPA determine if the
best-performing sources that provided the metals data are in communities or states that require
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use of amalgam separators. The commenters (124.1, 82.1) posed that the best performing sources
may not only be controlling mercury emissions through air pollution control devices, but may
also benefit from lower mercury content in sludge due to use of amalgam separators. One
commenter (80.1) stated that it is not clear if the difference in controlled Hg emissions from the
test data from St Paul (with carbon injection/baghouse) and Ypsilanti (with fixed bed carbon
adsorption) are due to differences in the effectiveness of the technologies or to differences in the
uncontrolled concentrations.
Response: Please see Section V.C of the preamble for EPA's response to these
comments. MACT floor limits are intended to reflect the best performing units, regardless of the
types of controls used on the units. Refer to the memorandum "Revised MACT Floor Analysis
for the Sewage Sludge Incinerator Source Category" (EPA-HQ-OAR-2009-0559) for a detailed
discussion on how the UPL was calculated.
10.3 Pollutant by Pollutant Approach is Unreasonable
Comment: Several commenters (85.1, 97.1, 127.1,67.1, 102.1, 116.1,95.1, 109.1, 105.1,
105.1, 137.1, 134.1) stated that the pollutant-by-pollutant approach to determine the MACT floor
is unreasonable. Commenters (97.1, 127.1,80.1,67.1,95.1,73.1, 109.1, 105.1, 137.1, 129.1,
134.1) stated that deriving the MACT floor for each pollutant based on the emissions levels
achieved by the best-performing single unit for each pollutant is unrealistic and creates emissions
standards that cannot be met by any single operating SSI unit.
At least one commenter (97.1, 127.1) argues that Section 129 specifies that emissions
standards must be established based on the performance of "units" in the category or subcategory
and that EPA's discretion in setting standards for such units is limited to distinguishing among
classes, types, and sizes of units. The commenter states that the standards must be based on
actual units and cannot be the product of pollutant-by-pollutant parsing; the commenter asserts
that EPA does not have the authority to "distinguish" units and sources by individual pollutant,
citing Sierra Club, 551 F.3d at 1028.
Another commenter (95.1) stated that the statutory provision for new sources states that
MACT floor standards must be based on the emission controls achieved by the "best controlled
similar unit." The commenter (95.1) infers that EPA has a duty to find the single best unit, citing
Sierra Club v. EPA, 167 F.3d. 658, 665 (D.C. Cir. 1999), noting that use of the singular in the
statutory language suggests EPA look to the single "unit with the best observed performance".
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Furthermore, the commenter (95.1) provided text of an exchange between Senator Dole and
Senator Durenberger (Senate Comm. on Environment and Public Works, 103d Cong., A
Legislative History of the Clean Air Act Amendments of 1990 at 1118) regarding how EPA must
select the best performing sources when confronted with differing technology that reduces
different pollutants to different levels. The commenter (95.1) argued that EPA must set a
standard that a requisite number of best performers can meet without installing upgraded air
pollution control equipment, noting that this "amounts to a beyond the floor standard without
consideration of the beyond the floor factors" (70 FR 59402, 59443, October 12, 2005). The
commenter (95.1) stated that because the "pollutant-by-pollutant" methodology may result in
best performing sources taking actions to meet the standards, it is unlawful. The commenter
(95.1) provided an analysis of the available data and stated that none of the units in EPA's
database simultaneously achieve all the proposed existing source or new source standards; the
commenter (95.1) concluded from this analysis that EPA has improperly circumvented the
Section 129 requirements for establishing "beyond-the-floor" standards because the "floor
standards would force industry-wide technological upgrades without consideration of the factors
(cost and energy in particular) which Congress mandated for consideration when establishing
beyond-the-floor standards" (75 FR 63275). Similarly, at least two commenters (97.1, 127.1,
134.1) stated that because the proposed limits for each Section 129 pollutant could not be met by
the best-performing sources, that the limits were technologically unachievable. At least four
commenters (80.1, 67.1, 105.1, 137.1) specifically stated that based on a review of EPA's
emissions database, 11 of 30 test data points would not comply with the Cd standard, 28 of 30
data points would not comply with the Pb standard, 22 of 30 would not comply with the HC1
standard, 6 of 6 data points would not comply with the D/F TMB or TEQ, 86 of 105 would not
comply with the CO, and 8 of 15 would not comply with the NOx standard. At least one
commenter (134.1) stated that even the units considered to have the most advanced emission
control equipment (i.e., three units in St Paul, MN and one unit in Ypsilanti, MI) would be
unable to comply with the proposed regulation.
Several commenters (85.1, 97.1, 127.1, 80.1, 95.1, 56.1, 65.1, 90.1, 105.1, 137.1, 129.1,
134.1) specifically claimed that EPA did not appropriately consider that emissions of NOx and
CO are inversely proportional due to characteristics of combustion; therefore, no one new unit
would be able to meet the new standards for both. Some commenters (97.1, 127.1) requested that
EPA set limits based on the best performers for both pollutants simultaneously.
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Response: Please see Section V.C of the preamble for EPA's response to these
comments.
10.4 Criticisms of the Statistical Method
Comment: At least one commenter (86.1) asserted that EPA's determination of a normal
distribution (using skewness and kurtosis) for the data used for the MACT floors is incorrect.
The commenter (86.1) states that this determination is inconsistent with EPA's own Guidance for
Data Quality Assessment Manual, which holds that it is more likely that environmental data are
distributed log-normally. The commenter (86.1) further asserts that EPA's approach using
skewness and kurtosis is not robust, criticizing EPA's application of the criteria to a limited
sample size. The commenter (86.1) states that EPA must assume that the emissions data are non-
normally distributed unless rigorous statistical analysis shows otherwise.
Response: EPA has reviewed the document referenced and agrees with the commenter
that the referenced document shows that environmental data are more likely to be log-normally
distributed than normally distributed. Based on this, EPA has modified the assumptions made
when results of the skewness and kurtosis tests do not clearly show whether a normal or log-
normal distribution better represents the data, or when there are not enough data to complete the
skewness and kurtosis tests. In these cases, we have chosen to use the log-normal results for the
final MACT floor calculation.
Comment: One commenter (84.1, 119.1) stated that EPA selected the best performers
based on each source's lowest test result, but measured the best sources' actual performance
based on their average test results. The commenter (84.1, 119.1) claimed that this approach,
which uses different measures of performance, is inconsistent, irrational, and unexplained; the
commenter (84.1, 119.1) stated that the same metric should apply for purposes of identifying the
best performers and identifying those sources' actual performance. Additionally, the commenter
(84.1, 119.1) asserted that by using the lowest test result to identify the best performers but the
average test result to reflect their performance, EPA artificially increased the variability of the
data on which it bases floors, without providing sufficient explanation for this approach.
Response: Please see Section V.C of the preamble for EPA's response to these concerns.
Comment: Several commenters (84.1, 119.1, 86.1, 145.1) rejected the statistical
approach used by EPA to account for variability. Multiple commenters (86.1, 134.1) were of the
opinion that EPA erred in using a UPL-based approach. At least one commenter (134.1)
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specifically stated that the statistical approach was inappropriate for the small sample size, and
reiterated the need for a more robust data set. Several commenters (86.1) offered alternative
statistical approaches to account for variability and determining the MACT floor.
One commenter (84.1, 119.1) rejected EPA's application of the UPL to all test results for
all sources in the top twelve percent. The commenter (84.1, 119.1) asserted that the CAA
requires EPA to set floors reflecting the "average" emission level achieved by the best sources,
and therefore the UPL approach is unlawful. Furthermore, the commenter (84.1, 119.1) asserted
that although EPA may consider variability in estimating an individual source's actual
performance over time, the agency may not account for differences in performance between
sources except by averaging the emission levels achieved by the sources in the top twelve
percent. The commenter (84.1, 119.1) was of the opinion that EPA erred by viewing the different
emission levels achieved by different sources as "variability".
Similarly, other commenters (86.1) stated that the approach must consider variability
from individual best performing sources independently and give equal weight to data from each
source. Commenters (86.1, 95.1) expressed concern that EPA did not consider the number of
data points for each unit when accounting for variability, but instead pooled and utilized data
from all available test runs for the best-performing sources. One commenter (95.1) specifically
noted that when calculating the standard for CO, the EPA database has one source with one test,
one source with 13 tests, one source with 10 tests, one source with 12 tests, and one source with
2 tests. The commenter (95.1) remarked that EPA's method can only work properly if all the
facilities have the same number of samples. The commenters (86.1, 95.1) asserted that EPA's
analysis biases the MACT floor results by over-weighting the results for units that have more
data available.
Another commenter (86.1) stated that using the UPL is inappropriate because the UPL
adjustment incorrectly presumes that each test run result within a given 3-run test occurs
randomly over the entire population distribution. The commenter (86.1) argued that EPA's UPL
approach underestimates variability, noting that each of the three runs can only reflect conditions
(sludge characteristics, condition of combustor, season of the year) affecting a unit's emissions at
the time of the test, and that individual run results will not vary randomly across the entire
distribution of emissions that would be observed over longer (monthly or annual) time periods.
Commenters (85.1, 95.1 75.1, 76.1, 76.1,110.1, 145.1, 134.1) also criticized EPA's
approach of applying statistical analysis to single hourly test run results, stating that the average
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from three test runs from 20 MHF units around the country should have been utilized to develop
the standard. At least one commenter (95.1) stated that a single test run cannot constitute a valid
test sufficient to accurately judge the emission level achieved by a particular unit and cannot be
an accurate measure of the performance of the unit over time. One commenter (134.1)
specifically claimed that the mercury variability data illustrate that the UPL approach is
insufficient. The commenter (134.1) remarked that while the UPL statistical method may account
for between-test variability, it cannot fully account for the variability of the mercury
concentrations in the biosolids. The commenter (134.1) states that EPA's approach, which
considers each test run to be a distinct data point, limits the geographic distribution of the data
set to a very small sample. The commenter (134.1) referenced a January 2009 EPA report,
"Targeted National Sewage Sludge Survey Statistical Analysis Report" (TNSSS report) which
indicated high mercury concentration variability from plant to plant. The commenter
recommended that EPA acquire additional emissions data or incorporate the biosolids mercury
variability from the TNSSS report into the UPL method. These commenters (95.1, 76.1, 85.1)
stated that the average of three one-hour tests is more representative of SSI steady state
operations than any individual one-hour test.
Response: Please see Section V.C of the final SSI preamble for EPA's response to these
comments. Additional rationale for the UPL is in the NPRM.
Comment: At least two commenters (97.1, 127.1, 86.1) remarked upon EPA's usage of a
95 percent UPL. One commenter (97.1, 127.1) stated that EPA should not use a 95 percent UPL,
specifically, that to do so presumes that sources in the database would be expected to be out of
compliance 5 percent of the time, which is contrary to the CAA requirement that MACT limits
must be met at all times. Another (76.1) commenter stated that the 95 percent UPL results in
even more stringent standards than listed using the 99 percent UPL. One commenter (86.1) stated
that a 99th percentile UPL is inappropriate and inadequate. The commenter (86.1) requested that
if EPA employs a statistical limit to set MACT floor emission limits, it should use the 99.9%
limit. The commenter (86.1) noted that due to the small sample size, it is highly unlikely that the
highest emissions and full variability have been observed, therefore, a 99.9% UPL is more
appropriate than a 99% UPL. The commenter (86.1) additionally asserted that EPA cannot use a
95% UPL to calculate MACT floors on the basis that certain floors were higher than test data,
stating that EPA failed to provide adequate rationale for reducing the UPL percentile to 95
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percent. The commenter (86.1) remarked that EPA should revise its overall methodology and
calculate the 99.9% UL as the MACT floors.
One commenter (84.1, 119.1) asserted that EPA failed to provide an explanation for its
assumption that sources' actual emission levels will vary to the full extent of the 99th percent
UPL. The commenter (84.1, 119.1) argues that the UPL does not consider an operator's efforts to
limit variability in emissions by maintaining and operating the source carefully to control
emissions, therefore, the UPL results in floors that do not reflect the best sources' actual
performance.
Response: Please see Section V.C of the preamble for EPA's response to these
comments. Regarding the comment that the UPL does not consider an operators efforts to limit
variability in emissions, we lack data to determine if there any effects that need to be considered.
The commenter did not provide any input on how such variability could be identified and
incorporated into the UPL.
Comment: One commenter (84.1, 119.1) stated that EPA unlawfully rounded up its
emission test results for the purpose of setting standards, even though the agency's policy is to
round them down for the purpose of determining compliance. Specifically, EPA rounds up UPL
values less than 100 to one significant figure, and rounds up UPL values between 100 and 1000
to two significant figures. The commenter states that this approach is inconsistent for setting
standards. Another commenter (90.1) specifically stated that the significant digits used in
calculating the CDD/CDF reduction exceed that supported by the uncertainty in the CDD/CDF
calculation, therefore the reduction calculation is unreliable.
Response: All values were rounded up to two significant figures following EPA's
procedures for calculation of the UPL based limits. Please refer to Section V.C of the preamble
for further detail on the development of the final limits.
Comment: One commenter (134.1) specifically requested further justification regarding
the exclusion of SO2 data from the Ypsilanti, MI facility. The commenter (134.1) remarked that
the test method used for this facility was allowed by regulation, therefore, these data points
should not have been discarded simply because they were higher.
Response: The SO2 emissions from Ypsilanti were two orders of magnitude greater than
all the other SO2 test information. A review of the source test report indicated a different test
method was used than used at all the other facilities providing SO2 data. Additionally, the
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reported emissions in the report could not be replicated using the raw data. For these reasons, the
emissions data was not appropriate to use in calculating the MACT floors.
10.5 Treatment of Non-Detect Data
Comment: Some commenters (84.1, 119.1, 134.1, 53.1) rejected EPA's approach to non-
detect data as unlawful, arbitrary, or flawed. At least one commenter (134.1) stated that the
amount of non-detect data (more than 50%) was excessive and introduced uncertainty in the
proposed MACT floor levels. Another commenter (84.1, 119.1) stated that assigning a value
three times higher than the detection limit when the test result is below the detection limit
substantially overestimates units' actual performance and does not reflect sources' emission
levels.
Specifically, one commenter (53.1) stated that EPA's approach to non-detect data for HC1
and CDD/CDF was flawed. Some commenters (90.1, 134.1) claimed that the CDD/CDF limits
were likely too high, based on the use of non-detect data. One of these commenters (90.1) argued
that given the high number of non-detects, there is no evidence to support the regulation of
CDD/CDF from SSI units. Another commenter (132.1) expressed concern over the treatment of
non-detect data from pollutants other than HC1 and D/F, which were not discussed in the
preamble to the proposed rule.
Some commenters (53.1) stated that EPA's selection of the highest detection limit
reported in the data set is based on an erroneous assumption that the detection limit is a function
of the pollutant emission rate. Furthermore, the commenter (53.1) asserted that by using the data
from the low-emitting sources and ignoring the data from sources with higher emission rates,
EPA biased its analysis. The commenter (53.1) also stated that the non-detection values used by
EPA in its proposal do not account for sources of error associated with sample collection and
handling, which should be considered in establishing the detection limit of a source test method.
The commenter (53.1) suggested alternative approaches for calculating the MACT floor for
pollutants with a high number of non-detects.
One commenter (95.1) completely rejected EPA's use and adjustment of the detection
limit (DL) in the data used to set the standards. The commenter (95.1) stated that EPA should use
the Reporting Limit (RL), or the lowest value at which a laboratory analytical instrument is
calibrated, instead of adjusting the detection DL. The commenter (95.1) argues that the RL is
superior to the DL because the RL is a quantification level includes an acceptable calibration
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point. The commenter (95.1) notes that use of the RL will eliminate the need to include
analytical variability because the data is at or near the detection limit. The commenter (95.1)
states that if the data reported is not based on an RL, the quality of the data is not adequate to set
standards and other data must be used.
At least one commenter (95.1) stated that the quality of the data EPA used to set the floor
standard for total chlorine emissions is not sufficient to set standards at this level. The
commenter (95.1) expressed that facilities would not be able to demonstrate compliance with the
standard as proposed. The commenter (95.1) expressed concern that the low values in the EPA
database may be biased or inaccurate, noting that Method 26A suffers from a negative bias at
low concentrations (< 20 ppm) , especially when used in stacks with significant moisture
contents (this problem is more pronounced at HCI concentrations in the low ppm range). The
commenter (95.1) further noted that a number of sewage sludge incinerators control chlorine
emissions with wet scrubbing systems that will introduce moisture into the stack gas and affect
sampling results. The commenter also stated that alkaline particulate matter collecting on the
filter upstream of the measurement impingers would also result in a negative bias, and noted that
wet scrubbers typically use caustic to neutralize acid gases that could entrain HCI prior to
sampling.
Another commenter (95.1) stated that the stack sampling methods utilized to determine
compliance with the chlorine standards were not reliable and therefore unusable to set the
standard. The commenter (95.1) stated that the precision and accuracy of Methods 26, 26A,
0050, and 0041 are lower at concentrations below 5 ppm. The commenter (95.1) further argued
that while Method 26A suggests a theoretical "detection limit" of 0.08 ppm for the combined
HCI and C12 based on the analytical measurement only, in practice, laboratories have found that
actual defensible analytical reporting limits are approximately 5 to 10 times higher (i.e., 0.4 to
0.8 ppm). The commenter (95.1) suggests that EPA either discard the data from sources
reporting emissions below 5 ppmv when developing a numeric standard, or find a way to
compensate for the known negative bias in the data.
Response: We agree that at very low emission levels where emissions tests result in non-
detect values, the inherent imprecision in the pollutant measurement method has a large
influence on the reliability of the data underlying the MACT floor emission limit. Because of
sample and emission matrix effects, laboratory techniques, sample size, and other factors,
method detection levels normally vary from test to test for any specific test method and pollutant
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measurement. The confidence level that a value measured at the detection level is greater than
zero is about 99 percent. The expected measurement imprecision for an emissions value
occurring at or near the method detection level is about 40 to 50 percent. Pollutant measurement
imprecision decreases to a consistent level of 10 to 15 percent for values measured at a level
about three times the method detection level. The approach EPA has used to account for
measurement variability begins by defining a method detection level that is representative of the
data used in the data pool. The first step in the approach is to identify the highest test specific
method detection level reported in a data set that is also equal to or less than the average
emission calculated for the data set. This approach has the advantage of relying on the data
collected to develop the MACT floor emission limit, while to some degree, minimizing the effect
of a test(s) with an inordinately high method detection level (e.g., the sample volume was too
small, the laboratory technique was insufficiently sensitive or the procedure for determining the
detection level was other than that specified). The second step is to determine the value equal to
three times the representative method detection level and compare it to the calculated MACT
floor emission limit. If three times the representative method detection level were less than the
calculated MACT floor emission limit, we concluded that measurement variability is adequately
addressed, and we did not adjust the calculated MACT floor emission limit. If, on the other hand,
the value equal to three times the representative method detection level was greater than the
calculated MACT floor emission limit, we concluded that the calculated MACT floor emission
limit does not account entirely for measurement variability. We therefore used the value equal to
three times the method detection level in place of the calculated MACT floor emission limit to
ensure that the MACT floor emission limit accounts for measurement variability and
imprecision.
We found that none of the alternative approaches for determining emissions limits
suggested by the commenters were as suitable, consistent, clear, or easily-applied as our
procedures; therefore, we did not incorporate their use in this rule. With regards to the reporting
limit (RL), no standard method defines the reporting limit, so differing laboratories have
developed individual reporting limits using owner-defined criteria. The arbitrary way in which
reporting limits were and are developed prevented their use in determining emissions limits. In
contrast, our procedures for determining emissions limits rely on the detection capabilities of the
laboratories' instrumentation along with an adjustment, when necessary, that accounts for errors,
including those associated with measurement uncertainty, sample collection, and handling.
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Please refer to the memorandum "Revised MACT Floor Analysis for the Sewage Sludge
Incinerator Source Category" (EPA-HQ-OAR-2009-0559), for a discussion on how non-detect
values were handled for all pollutants.
Comment: One commenter (134.1) requested that EPA validate that each facility in the
inventory properly determined the associated method detection limits, particularly for data
reported near or at the detection limit for a given test method. Another commenter (134.1)
requested that the data used to calculate the MACT floor levels be examined to verify if the
instruments were properly calibrated to verify the accuracy of the data; the commenter (134.1)
further asserted that results reported below the lowest calibration point should be not be
considered in the data set, as they are unreliable.
Response: EPA acknowledges the commenters' concerns regarding an additional
validation of data reported in the ICR or examination of instrument calibration used to determine
data reported in the ICR. Owners or operators who received ICRs were required to obtain and
report their data in a specific manner; moreover those owners or operators were required to
certify that their data were collected, determined, and reported accurately. Given these
requirements, we have no reason to believe data reported near or at the detection limit for a given
test method, or any other data, were determined improperly. We do not agree that data reported
lower than the calibration point but higher than the detection level should be excluded from the
data set; the inability of current instrumentation to be calibrated at lower levels has no impact on
the expected distribution of emissions values. Values below the calibration level, as well as
below the detection level, exist, and their elimination would bias the data set high. Our current
procedure accounts for this bias by including those data between the calibration and detection
levels, and adjusting the resulting emissions limit as necessary to account for errors such as
instrumentation insensitivity.
10.6 Comments on NOX Limits
Comment: Several commenters (75.1, 134.1, 80.1, 102.1, 116.1, 138,) are concerned that
existing units will not be able to meet the proposed NOx emission limits. At least two
commenters (102.1, 116.1, 138) stated that the NOx emissions limits do not correctly account for
the variability of sludges that will enter into incinerators. Another commenter (134.1) also
argued that NOX emissions can increase significantly with fluctuations in the sludge feed
characteristics (percent solids and percent volatile content) and with incinerator operating
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conditions (i.e. variations or interruptions in sludge feed rate). The commenter (134.1) provided
an analysis of 154 sets of SSI emission data (taken from the EPA Sewage Sludge Test Programs)
showing the average NOX emission from a MH incinerator was 283.6 ppmdv corrected to 7% O2
with a standard deviation of 165.2 ppmdv. The commenter (134.1) recommended a NOX
emission limit of 365 ppmdv corrected to 7% O2 for existing MH incinerators which is the
average value from the analysis plus half of the standard deviation (283.6 + 165.2/2). Two
commenters (102.1, 116.1, 134.1) stated that at relatively low solids concentration (20% to 24%)
it is possible to consistently meet the proposed NOX standard for FB incinerators. However, the
commenters (102.1, 116.1, 134.1) noted that at higher solids concentrations (28% to 30% or
higher) which are typically achieved with de-watering equipment, NOX emissions would be
significantly higher than the 63 ppmdv limit. The commenter (102.1, 116.1) noted that in order
to conserve fuel, many WWTPs have upgraded their dewatering equipment to produce higher
solids sludge. Another commenter (134.1) recommended a NOX emission limit of 150 ppmdv
corrected to 7% O2 for FB incinerators. The commenter (134.1) pointed out that this is about the
lowest level which a fluidized bed supplier is willing to guarantee on a new FB incinerator.
The same commenter (134.1) contended that the proposed NOX limits are not truly
representative of actual long-term system performance because they were based on a limited data
set. The commenter (134.1) stated that specific control devices or processes to control or reduce
NOX are virtually non-existent in SSI installations, despite the fact that some units have existing
permit limits related to NOX emissions. The commenter (134.1) stated that these historical limits
have been based more on what has typically been observed for each subcategory of SSI unit than
on any underlying theory or control mechanism; historical limits have often been expressed in
terms of pounds emitted per pound of feed processed or in terms of concentration limits. The
commenter (134.1) is concerned that the proposed limits for existing and new SSI units are
overly restrictive (particularly the limits for new SSI units) and would require the use of add-on
control technology that has not been proven in SSI applications. The commenter (134.1) urged
EPA to consider that the proposed limits for CO emissions have an impact on the NOX emissions
as well; and stated that they believe that NOX emissions are adequately managed under the PSD
requirements.
Response: EPA's variability analysis, based on the emissions data collected, adequately
characterizes the impact of potential differences in sludge contents on emissions of NOX as well
as other pollutants. The MACT floor limits in the final rule are described in the memorandum,
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"Revised MACT Floor Analysis for the Sewage Sludge Incinerator Source Category" in the SSI
docket (EPA-HQ-OAR-2009-0559). Based on the NOX concentration data collected, EPA
believes the majority of MH units will be able to meet the final NOX emission limit of
220 ppmvd and that the majority of FB units will be able to meet the final NOX emission limit of
150 ppmvd. For the units expected to need further NOX control, EPA believes that selective non-
catalytic reduction would be a feasible control option. We also note that NOX emissions are not
solely influenced by the solids content, but also the combustion characteristics of the incineration
unit. The additional data cited by the commenters was only a summary that did not contain test
information. Therefore, we were not able to evaluate whether he data was collected using
appropriate test methods and quality control procedures. Additionally, variability can only be
determined using the information from the best-performing 12 percent of existing sources, or the
best single source. We requested additional test information in the NPRM, but did not receive
any in the comments.
10.7 Comments on the HCI Standards
Comment: One commenter (129.1) stated that they did not know of any method to
reduce hydrogen chloride emissions from sewage sludge incinerators, which are negligible.
Response: EPA maintains that packed bed scrubbers can reduce HCI emissions
sufficiently to meet the emissions standards. Currently 6 SSI units use packed bed scrubbers.
Comments have not provided any data that refutes our determination.
10.8 Comments on Mercury Limits
Comment: Several commenters (101.1, 126.1, 134.1) stated specific concerns with the
data used to set the mercury emission limits for both types of SSIs. For example, commenters
(101.1) state that only two incineration sites (4 fluidized bed incinerators) incorporate all of the
activated carbon based mercury removal devices. Commenters (101.1, 126.1, 134.1) cited the
average mercury concentration in sludge as 5.22 mg/kg. Three commenters (65.1, 101.1, 126.1)
noted that the four FBIs which incorporated activated carbon based mercury removal devices
only had a sludge feed inlet concentration of 0.6 mg/kg mercury, or roughly an order of
magnitude less than the mercury levels present at an "average" facility. The commenters (101.1,
126.1) argue that the statistical methodology cannot accurately establish the MACT floor for all
sources and that more information must be collected.
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Response: After evaluating the revised emissions dataset (see the memorandum "Post-
Proposal SSI Database Revisions and Data Gap Filling Methodology"(EPA-HQ-OAR-2009-
0559) for further details) EPA concluded that it would not be cost effective to go beyond-the-
floor for mercury control. Therefore, the final mercury emission limits are 0.037 mg/dscm for FB
units (as opposed to the proposed limit of 0.0033 mg/dscm) and 0.28 mg/dscm for MH units (as
opposed to the proposed limit of 0.02 mg/dscm). Please see Section V, Part C of the preamble for
EPA's response to specific concerns regarding the statistical methodology for determining the
MACT floor and the memorandum, "Revised MACT Floor Analysis for the Sewage Sludge
Incinerator Source Category" in the SSI docket (EPA-HQ-OAR-2009-0559).
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11.0 BEYOND THE FLOOR ALTERNATIVES
11.1 BTF for Mercury
Comment: One commenter (76.1) argued that EPA must use the MACT floor limit for
mercury until EPA completes a full human health risk assessment and environmental impact
statement to justify decreasing the mercury limit to beyond-the-MACT-floor limit. The
commenter (76.1) added the justification for beyond-the-MACT-floor limits for mercury is a net
improvement in public health and the environment. The commenter stated that EPA did not even
quantify the level of benefit to public health and the environment, and asserted that EPA simply
stated that since Hg is a persistent bio-accumulative toxic (PBT) pollutant, the beyond-the-
MACT-floor limit was justified. Another commenter (85.1) argued that EPA failed to identify
any mercury benefits in the proposed mercury beyond-the-floor standard , but instead considered
benefits from particulate matter reduction as a surrogate for the benefits of mercury reduction.
The commenter (85.1) noted that EPA's failure to identify actual mercury benefits in the beyond
the floor standard renders its analysis deficient in this respect.
Conversely, some commenters (79.1, 84.1, 119.1) supported EPA's decision to propose a
beyond the floor limit for mercury. One commenter (84.1, 119.1) contended that mercury is
extremely toxic and can cause tragic adverse health effects even in tiny quantities. Further
because mercury is extremely persistent in the environment and bioaccumulative, mercury
emissions result in long term contamination the environment, food sources, and wildlife and pose
an on-going and increasing threat to human health. The commenter (84.1, 119.1) added that
because EPA's floors for mercury are far less protective than § 129 requires (see above), they
would allow many of the dirtiest SSI to avoid controlling their mercury emissions. The
commenter stated that setting beyond the floor standards would ensure that these units will
reduce their emissions. The commenter (84.1, 119.1) agreed with EPA that SSIs' emissions of
mercury can be substantially reduced by a control technology that is both available and
affordable, activated carbon injection. The commenter (79.1) added they strongly encourage
EPA to retain these provisions in the final rule. One commenter (138) urged EPA not to rush
these types of rules as they are significant, and they will change the disposal methods used by
many utilities. The commenter (138) stated that it is essential that EPA take more time to
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understand the implications of setting the mercury limits below or the MACT standards,
alternatives, and the time that facilities have for compliance.
Response: We have revised the beyond-the-floor analysis to incorporate changes made to
the baseline emissions, new facility specific data and inputs provided by commenters, and
revised control options. Based on the results of the beyond the floor analysis we have selected
the MACT floor level of control for the final rule. Our beyond-the-floor analyses for the final
standards are discussed in the preamble to the final SSI rules and documented in the
memorandum "Revised Analysis of Beyond the Maximum Achievable Control Technology
(MACT) Floor Controls for Existing SSI Units" (EPA-HQ-OAR-2009-0559).
11.2 Over/Understated Mercury Emissions/Costs
Comment: Several commenters urged EPA to reconsider the beyond the floor mercury
limit because emissions were overstated (97.1, 127.1,76.1,73.1, 134.1,75.1,85.1,90.1, 111.1,
118.1) and costs formercury control were underestimated (76.1, 73.1, 75.1, 85.1, 90.1, 97.1,
127.1, 109.1, 126.1, 129.1, 132.1, 134.1, 136.1, 61.1). One commenter (109.1) stated that the
EPA determination that mercury emission control for existing SSIs as cost effective is seriously
flawed to "justify" the proposal to set the mercury emission limit for existing furnaces 88%
below the MACT floor level; the commenter states that to do so arbitrarily poses a non-
achievable mercury compliance limit for most facilities. Another commenter (49.1) argued that
the total percentage of mercury being emitted from SSI's accounts for only about 1% to 2% of
total atmospheric mercury that is from other global, natural and industrial Hg sources. One
commenter (138) stated that the proposed mercury limits were "magnitudes below" the MACT
standards, citing a flawed cost/benefit ratio.
One commenter (75.1) stated they would not be able to meet the proposed mercury
standard, even with activated carbon injection. Commenters (109.1) stated that the extremely
high cost-low emission reduction benefit imbalance of the proposed mercury limit needs to be
fundamentally reconsidered by EPA. One commenter (97.1, 127.1) argued that EPA is
compelled to explore alternative, less costly ways to decrease mercury emissions before
imposing beyond the floor controls, stating that EPA's beyond the floor mercury limits are not
justified by the record and should be removed from the final rule. The commenters (109.1)
requested that EPA revise the proposed rule to have a more realistic and achievable mercury
emission limit for existing sources.
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Response: We have revised the beyond-the-floor analysis to incorporate changes made to
the baseline emissions, new facility specific data and inputs provided by commenters, and
revised control options. Based on the results of the beyond the floor analysis we have selected
the MACT floor level of control for the final rule. Our beyond-the-floor analyses for the final
standards are documented in the memorandum "Revised Analysis of Beyond the Maximum
Achievable Control Technology (MACT) Floor Controls for Existing SSI Units" (EPA-HQ-
OAR-2009-0559).
We have reviewed the commenters concerns regarding Hg control technologies and agree
that applying carbon injection to existing scrubbers has not been demonstrated to be effective at
removing Hg. For other combustion sources, carbon injection in combination with a FF has
proven to be highly effective in removing Hg. However, we also agree that for high moisture flue
gas streams, such as emitted from SSI units, the use of FFs is problematic due to
plugging/fouling. In order to use carbon injection with a FF with high moisture streams, a waste
heat boiler, RTO, or afterburner is necessary to maintain a high enough temperature to keep the
stream above the dew point prior to sending the stream to the FF. Additional equipment may also
be necessary to reduce the temperature of the flue gas to prevent damage to the fabric filter bags.
Please see Section V, Part E of the preamble for EPA's more detailed response to these
comments. A detailed discussion of the costs and emissions reductions estimates for the final
standards is provided in the memorandum "Revised Cost and Emission Reduction of the MACT
Floor Level of Control" in the SSI docket (EPA-HQ-OAR-2009-0559).
Comment: One commenter (134.1) asserted that EPA inappropriately used the HMIWI
cost model and ignored several major cost factors, claiming that the costs for both MACT
compliance and BTF MACT compliance are under-estimated. The commenter (134.1) stated that
EPA failed to identify key differences between the processes of incinerating hospital waste and
biosolids. The commenter (134.1) asserted that EPA did not realize that the two wastes (HMIW
and Sewage Sludge - SS) and the methods used to control emissions from combustion of these
wastes are fundamentally different. The commenter (134.1) stated that HMIW has a relatively
low moisture content (approximately 10% to 20%), whereas sewage sludge (SS), as fed to a
combustion unit, is 70% to 80% water. The commenter (134.1) asserted that this means that the
flue gas from a SSI has a much higher water vapor content than that form an HMIWI, and
concluded that the size, configuration, and air pollution control methods of an HMIWI are
markedly different than that for an SSI. The commenter (134.1) stated that practically all SSIs
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have some type of wet scrubbing system (or wet scrubber in combination with wet electrostatic
precipitator) to control their emissions, and noted that there are only three SSIs in the US that use
fabric filters for emission control, located at the same treatment plant.
Response: EPA is not prescribing a specific control technology or method. A source is
required to meet the final emissions limits in these standards, and has the flexibility to use the
control method or technology that is best suited for their individual facility. EPA's costs are
estimated based on technologies we believe may be appropriate for the sources to meet the
emissions limits. Cost algorithms are based on those used for HMIWI controls, but these were
modified to incorporate parameters specific to the SSI units rather than HMIWI units. For the
final standards we have also revised the types of controls costed to meet the MACT floor limits.
For SSI's that we estimate will need further control of PM, Cd, or Pb to meet the MACT floor,
we have costed out wet ESP as a more appropriate PM control for high moisture streams. We
have also costed out SNCR for SSI's that we estimate will need further control of NOx to meet
the MACT floor limits. As at proposal, we have costed out packed scrubbers for SSI's that we
estimate will need further control of HC1 or SO2. At the MACT floor level, we do not estimate
that any SSI's will need to add control for Hg, PCDD/PCDF, or CO. A detailed discussion of the
costs and emissions reductions estimates for the final standards is provided in the memorandum
"Revised Cost and Emission Reduction of the MACT Floor Level of Control" in the SSI docket
(EPA-HQ-OAR-2009-0559).
11.3 Alternative Mercury Control Options
Comment: Some commenters (80.1, 137.1) stated that EPA has not considered the
technical, economic and environmental benefits of other technologies for mercury control in
establishing the MACT floor. The commenters (80.1, 137.1) specifically requested that EPA
consider allowing fixed-bed carbon adsorption over carbon injection, stating that carbon
injection is not as effective as fixed-bed adsorption when elemental mercury makes up a
significant portion of the mercury in the flue gas. One commenter (105.1) stated that carbon
injection has not shown to be as effective as fixed-bed adsorption when elemental Hg makes up a
significant portion of the Hg in the flue gas. Another commenter (67.1) recommended the use of
fixed bed carbon canisters, stating that this technology has a longer operating history, is operator
friendly, has low operation and maintenance costs, and can meet the proposed MACT standards
when coupled with a WESP. One commenter (80.1) stated that a WESP with a packed bed
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section and fixed bed carbon adsorption may be sufficient. One commenter (49.1) recommended
that EPA perform a cost/benefit analysis for installing fabric filters on high efficiency ESP. One
commenter (105.1) stated that there are numerous modern fluidized bed incinerators already
equipped with high-efficiency wet scrubbers for PM and metals control, several of which are
equipped with fixed bed carbon adsorption forHg control. Several commenters (87.1, 115.1,
112.1) stated that a significant drawback of activated carbon injection is that the mercury-laden
carbon and ash cannot be collected separately, thereby eliminating currently-implemented
beneficial use options for the ash. At least one commenter (87.1, 112.1) suggested fixed bed
carbon adsorption (i.e., Kombisorbon Process) be utilized to allow ash and carbon to be disposed
of separately, preserving beneficial use options for the ash.
Response: EPA is not prescribing a specific control technology or method. A source is
required to meet the final emissions limits in these standards, and has the flexibility to use the
control method or technology that is best suited for their individual facility. EPA did not have
sufficient cost information to fully evaluate fixed carbon adsorption or similar controls. We have
revised the beyond-the-floor analysis to incorporate changes made to the baseline emissions, new
facility specific data and inputs provided by commenters, and revised control options. Based on
the results of the beyond the floor analysis we have selected the MACT floor level of control for
the final rule. Our beyond-the-floor analyses for the final standards are documented in the
memorandum "Revised Analysis of Beyond the Maximum Achievable Control Technology
(MACT) Floor Controls for Existing SSI Units" (EPA-HQ-OAR-2009-0559).
Comment: One commenter (49.1) provided an alternative means to reduce mercury
emissions using a chemical precipitation process on the effluent water stream from the
incinerator wet scrubber. The commenter (49.1) stated the process uses lime, polymer,
flocculation, and filtering equipment to precipitate bound mercury in the scrubber effluent
instead of recycling back to the plant influent. The commenter (49.1) added that the process
could be more cost effective than carbon adsorption, and that less operation problems occur since
the equipment is out of the incinerator flue gas system. The commenter (49.1) noted a major
advantage of the use of chemical precipitation is that heavy metals and bound mercury can be
concentrated into a slurry for landfill disposal or chemical treatment rather than being dispersed
back into the environment.
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Response: EPA thanks the commenter for their input. However, EPA did not have
sufficient data on the cost and performance of the technology to fully evaluate it as a viable
control option.
Comment: Two commenters (49.1) noted that replacing an outdated wet venturi scrubber
with a new high efficiency electrostatic precipitator or Venturi-Pak scrubber will reduce the
bound mercury emissions, but not the elemental (gaseous) mercury. Atlanta documented bound
mercury emissions reduction using the Venturi-Pak in a WEF 2002 paper. One commenter (49.1)
added that the capital cost to retro-fit an out-dated venturi scrubber is reasonable; to protect
public health, as new scrubbers can remove about 90+% of the submicron particulates, heavy
metals and bound mercury.
Response: EPA thanks the commenter for their input. However, EPA did not have
sufficient data on the cost and performance of Venturi-Pak scrubbers for Hg control to fully
evaluate it as a viable control option.
Comment: Two commenters (126.1, 101.1) supported using activated carbon polishing
instead of activated carbon injection. The commenter (101.1) stated that, in addition to a PM
control device, activated carbon injection requires instrumentation and controls to regulate the
amount of carbon used to match the exhaust gas flow and mercury content. The commenter
claimed that at their facility, activated carbon injection prior to the wet scrubber is unfeasible
because the afterburner exhaust prior the scrubber is too hot (> 1500°F). The commenter stated
that an activated carbon polish unit (an adsorber column or tower filled with treated granular or
pelletized activated carbon) is preferred because it has no moving parts (exhaust is directed
through a static bed of carbon) and does not require another PM control device. The commenter
(126.1) noted benefits of no moving parts and no additional required PM control device for
activated carbon polishing, unlike activated carbon injection, which requires controls and
instrumentation to match flue gas flow and mercury concentration and additional PM control.
The commenter (126.1) pointed out that mercury removal using iodine or sulfur-impregnated
granulated activated carbon filters is proven technology; however, no carbon filter systems exist
on MH incinerators. The commenter stated that mercury removal rates of greater than 98% have
been documented by Kombisorbon®.
Response: EPA thanks the commenter for their input. We do not have information on the
cost and performance of this technology for SSI units, and whether it has been demonstrated on
SSI units.
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Comment: A commenter (56.1) indicated the removal of mercury using carbon filters has
been demonstrated on FB installations where inlet temperature and moisture to the carbon filter
are controlled. The commenter stated that these systems elevate the flue gas temperature prior to
the carbon filter to maintain temperatures above the dew point to control moisture to the filter.
The commenter further stated that elevating the flue gas temperature to the carbon filter uses
more fuel, and produces more NOX and CO emissions. However, the commenter (56.1) added the
exit flue gases from the post scrubber configuration, (either RTO or Recuperative Heat
Exchanger / Separate Chamber Afterburner) are relatively low temperature, above the dew point,
and relatively VOC free thus ideal for lower cost mercury removal in an add-on carbon filter
following the RTO. The commenter stated that costs of a carbon filter after an RTO will be less
expensive than carbon injection with baghouse; therefore, carbon use will be less and carbon /
mercury disposal will be less.
Response: EPA is unaware of SSI units that use this technology and would need more
information regarding the technology's performance and cost in order to fully evaluate it.
Comment: One commenter (134.1) stated that the most reasonable way to add mercury
control to the existing MHs is to use a carbon adsorber downstream of the existing wet scrubbing
systems. However, the commenter stated that upon economic analysis, the resulting costs are
clearly excessive and not justifiable. The commenter stated that this is particularly true when one
considers that EPA will be proposing this year new Effluent Guidelines for dental offices, which
are expected to remove approximately half of the mercury entering WWTPs.
Response: EPA thanks the commenter for their input.
11.4 Opposition to ACI
Comment: Several commenters (80.1, 67.1, 105.1) argued against EPA's proposed
beyond the floor control option of activated carbon injection ahead of a fabric filter for mercury
and dioxin/furans control. Commenters (118.1, 90.1, 122, 123) contended that the proposed rule,
as written, forces SSIs to install unproven mercury reduction technologies (58) that could result
in the expenditure of millions of dollars in possibly a futile attempt to remove mercury and the
failure of which would result in significant non-compliance with unachievable limits. Some
commenters (67.1, 105.1) argued that carbon injection consumes significantly more carbon,
generates more solid waste, has higher capital and maintenance costs, and has significantly
higher operation costs than alternative fixed bed technologies. One commenter (48.1) expressed
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concerned that the mercury control requirement of a fabric filter with activated carbon injection
would preclude the use of a wet ESP, which are already in place.
Several commenters (56.1, 90.1, 118.1, 122, 123) noted that carbon injection mainly
removes mercuric chloride, and the removal of elemental mercury is unproven. Commenters
(85.1, 97.1, 127.1) added that adsorption will not be as effective as EPA predicted due to low
mercury concentrations in the exhaust gas. Additionally, one commenter (85.1) pointed out that
mercury concentration in SSI exhaust are variable and EPA's selection of an 88% reduction
efficiency does not account for the variability. Two commenters (109.1, 134.1) noted the high
moisture content of the exhaust gas will blind the activated carbon, blocking mercury adsorption.
Several technical issues were also pointed out by commenters. Several (85.1, 97.1, 127.1,
90.1, 118.1, 109.1, 122, 123, 129.1, 138) pointed out that flue gas exhaust temperatures from
MH incinerators are much higher than FB units and argued that mercury adsorption is a function
of temperature and it is questionable whether mercury would adsorb at higher MH temperatures.
One commenter (138) noted that at the Saint Paul Metro WWTP, the only wastewater treatment
plant in the United States that injects activated carbon into its incinerator exhaust gas system, the
carbon is injected into a carbon contact chamber followed by a fabric filter, and the incinerator
exhaust gases entering the contact chamber are around 450 degrees Fahrenheit. The commenter
(138) argued that since multiple hearth incinerators have exhaust gas temperatures in the range of
1000 to 1600 degrees Fahrenheit and minimal residence time within the exhaust gas ductwork,
mercury adsorption would be negligible. One commenter (96.1) stated that although the ERG
memo assumes mercury removal can be achieved with the addition of an activated carbon
injection system to the exhaust gas stream, there is a limited temperature range required (300 to
400 degrees F) for effective mercury removal, which means that the normal incinerator exhaust
gas exit temperature must be cooled with a waste heat boiler and heat exchanger, or with a very
tightly controlled quencher - prior to injection.
Other commenters (129.1) pointed out that current system configurations do not allow
sufficient residence time for adsorption to occur. Issues with equipment degradation, such as
corrosion and abrasion (85.1, 97.1, 127.1, 111.1, 121.1, 129.1), erosion of refractory lining
(129.1), and other adverse impacts (90.1) were pointed out by several commenters. One
commenter (129.1) added when using activated carbon injection, the potential for scouring or
plugging of the scrubber exists. A number of commenters (76.1, 85.1, 90.1, 118.1, 122, 123)
claimed that the assumption that existing PM control devices can also remove activated carbon is
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not valid. Several commenters (85.1, 97.1, 127.1, 118.1, 121.1, 129.1, 58, 63.1) claimed
equipment in addition to EPA's estimates will be required; commenters (49.1, 85.1, 79.1, 127.1,
109.1, 111.1, 134.1) also stated that adding space to install the equipment is limited if at all
available. The additional equipment mentioned included fabric filters, which commenters (49.1)
stated were not cost effective and had issues of "mudding" due to high moisture content exhaust
streams (56.1, 90.1, 118.1, 122, 123). One commenter (145.1) stated that there is practically no
experience with the use of fabric filters for SSIs. The commenter (145.1) asserted that there is no
other solid waste other than sewage sludge that has moisture as high as 75%, stating that the
moisture content of flue gases from SSIs are about 30% by weight and 50% by volume. The
commenter (145.1) stated that although fabric filters may work well for other type of
incinerators, SSIs present different set of problems. The commenter (145.1) asserted that, due to
moisture, the dew point of the flue gas is relatively high and the gases are corrosive. Other
commenters (48.1, 87.1) claimed that that the combination of the high sulfur content in sludge
combined with the high moisture content in flue gas makes the application of a baghouse
"fraught with problems" relating to dew point corrosion.
Another commenter (56.1) pointed out that high temperatures to reduce moisture under
dew point uses fuel, contributes to NOX and CO emissions, and higher temperature can prove
harmful to the bags. One commenter (134.1) states that if the carbon is injected into the hot
incinerator flue gas without an upstream waste heat boiler, the carbon will simply burn up. The
commenter (134.1) added that if the flue gas from a SSI is cooled in a waste heat boiler prior to a
fabric filter, then activated carbon injection (ACI) upstream of the fabric filter is an effective
means of mercury control.
Some commenters (68.1, 115.1) provided that injection of activated carbon is not a
technically viable option for their units. The commenters (68.1) cited several reasons for the lack
of viability of activated carbon injection control, including that the current parti culate control
system is wet, the current air pollution control system is very close coupled, and the blowdown
from the wet parti culate collection system feeds back to the headworks of the wastewater
treatment system. The commenters (68.1) provided that specialty granular activated carbon may
be the only technically viable option for limitation of mercury and dioxin. Other commenters
(87.1, 112.1) stated that for flue gases with elevated levels of sulfur trioxide (>10ppm), sulfur-
resistant activated carbon will be required for effective removal of the mercury.
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Commenters (129.1) contended that the technology does not exist to meet each of the
proposed emission guidelines or new source performance standards on a continuous basis.
Commenters (80.1, 67.1, 83.1, 105.1, 129.1, 137.1, 138) noted that the fabric filter with alkali
reagent and carbon injection is only used on one operating SSI in the U.S. One commenter
(129.1) stated that the plant immediately ran into problems with its new system upon start-up,
since the exhaust gas temperature was too low and moist, and discovered that they needed to
raise the temperature of the gas stream prior to entering the adsorber. Several commenters (97.1,
127.1, 110.1, 83.1, 129.1, 145.1) asserted that this facility has had corrosion problems associated
with this technology, and that a second wastewater plant with an activated carbon polishing
system has reportedly had similar problems. Commenters (129.1) stated that due to problems at
St. Paul Metro WWTP, the carbon injection system (with a carbon contact chamber followed by
a bag house) is not a proven air pollution control technology for sewage sludge incinerators.
Commenters (129.1) also noted that activated carbon adsorbers would require a
substantial amount of space, including the total reconfiguration of and expansion of existing air
pollution control trains, and the expansion of incineration facilities by 20-30 feet or more; one
commenter (129.1) added that a carbon storage/conveyance system would be required. One
commenter (145.1) remarked that the fabric filters are a large piece of equipment and expressed
concern regarding space constraints; the commenter requested that the costs of reconfiguring the
existing equipment, ACP train, and modifying or enlarging the building be included in the cost
estimates. Other commenters (85.1) argued that EPA did not consider additional energy
requirements for the proposed control technology to meet the limit. The commenter (85.1)
indicated that increased energy use will occur through the addition of a carbon injection system
and a fabric filter (bag house), as would be required under the beyond-the-floor standards
associated with Option 2, yet the energy use shown for the "MACT Floor Only" option is
identical to the energy use shown for the other two options. One commenter (145.1) also stated
that the SSIs at the Metro plant are equipped with wet ESPs; the commenter requested that the
cost of wet ESPs be included in the cost estimates for the installation of fabric filters.
Numerous commenters (65.1, 85.1, 97.1, 127.1, 126.1, 129.1) pointed out the fate of
captured mercury, citing issues such as cycle up from scrubber water being re-introduced into
plant influent. Three commenters (85.1, 121.1, 129.1) pointed out that spent activated carbon
collected from fabric filters would be considered a hazardous waste, requiring disposal at a
hazardous waste landfill; another commenter (121.1) added that replacing spent carbon on a
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continual basis is expensive. One commenter (138) further argued that since plants recycle
scrubber water, the spent carbon will end up in the sewage sludge, and that the buildup of
mercury that could occur within the plant could result in a NPDES permit violation. Another
commenter (81.1) stated that the application of activated carbon into the exhaust gas system
without the installation of additional auxiliary systems would not prove effective; the commenter
asserted that without auxiliary systems, the mercury containing activated carbon would enter into
the wastewater collection system to be recycled in the sewage sludge process. The commenter
(81.1) asserted that this recycling would result in an accumulation of mercury within the
wastewater treatment system and subsequently could present a toxic effect on the biological
processes utilized at the facility. Another commenter (110.1) also argued that wet scrubbers
would merely transfer mercury release from one media (air) to another (water) with no net
benefit.
In general commenters (85.1, 79.1, 127.1, 111.1, 121.1) claimed that activated carbon
injection has not been proven successful, even on FB units, adding that the systems are
complicated and expensive (49.1, 111.1), and vendors have no experience installing systems on
MH units (85.1) since no MH units currently employ activated carbon injection (111.1, 97.1,
127.1). One commenter (138) stated that POTWs that utilize activated carbon injection will have
to install carbon contact chambers in baghouses. The commenter (138) requested that EPA
include these additional costs in the cost effective analysis for going beyond the MACT floor for
mercury. Two commenters (56.1, 90.1) contended the proposed rule as written, forces SSIs to
install unproven mercury reduction technologies that could result in the expenditure of millions
of dollars in possibly a futile attempt to remove mercury and the failure of which would result in
significant non-compliance with unachievable limits. The commenter (56.1) argued that EPA's
suggestion to use carbon injection be deleted from any final version of the rule.
Commenters (137.1) stated that there are many more modern FBIs and MHIs equipped
with high-efficiency wet scrubbers for PM and metals control and several equipped with fixed
bed carbon adsorption for Hg control. The commenters (80.1, 67.1, 105.1, 137.1) stated that to
base the standards on the performance achieved by only one unique installation serves only to
exclude other technologies that have much more widespread use, have long operating history,
and offer advantages in the wastewater treatment industry. Another commenter (56.1) argued
that EPA's suggestion to use carbon injection be deleted from any final version of the rule.
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Response: EPA is not prescribing a specific control technology or method. A source is
required to meet the final emissions limits in these standards, and has the flexibility to use the
control method or technology that is best suited for their individual facility. However, after re-
evaluating beyond-the-floor control options for mercury, EPA agrees with commenters that, for
SSIs, ACT alone is not an appropriate control option for mercury. After reconsidering beyond-
the-floor control options and revising the beyond-the-floor emissions reductions and cost
analyses based on data corrections or additional data received during the comment period, EPA
is not going beyond-the-floor in setting the final mercury limits. Please see Section V, Part F of
the preamble for further discussion regarding the beyond-the-floor options for mercury control.
EPA does not expect that units will need to install additional mercury control to meet the final
standards. Our beyond-the-floor analyses for the final standards are documented in the
memorandum "Revised Analysis of Beyond the Maximum Achievable Control Technology
(MACT) Floor Controls for Existing SSI Units" (EPA-HQ-OAR-2009-0559).
We have reviewed the commenters concerns regarding Hg control technologies and agree
that applying carbon injection to existing scrubbers has not been demonstrated to be effective at
removing Hg. For other combustion sources, carbon injection in combination with a FF has
proven to be highly effective in removing Hg. However, we also agree that for high moisture flue
gas streams, such as emitted from SSI units, the use of FFs is problematic due to
plugging/fouling. In order to use carbon injection with a FF with high moisture streams, a waste
heat boiler, RTO, or afterburner is necessary to maintain a high enough temperature to keep the
stream above the dew point prior to sending the stream to the FF. Additional equipment may also
be necessary to reduce the temperature of the flue gas to prevent damage to the fabric filter bags.
Please see Section V, Part E of the preamble for EPA's more detailed response to these
comments. A detailed discussion of the costs and emissions reductions estimates for the final
standards is provided in the memorandum "Revised Cost and Emission Reduction of the MACT
Floor Level of Control" in the SSI docket (EPA-HQ-OAR-2009-0559).
Comment: One commenter (134.1) argued that the proposed regulations should not force
the use of fabric filters in lieu of a well designed wet scrubbing system. The commenter (134.1)
stated that in general, the use of fabric filters in SSI units has been limited due to the high
moisture content of the exhaust gases and potential operating problems with fabric filter
collection systems. The commenter (134.1) purported that FB units have been designed with
more comprehensive and effective PM control technologies than MH units. The commenter
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(134.1) stated that this is expected as many of the FB systems are newer and have conventional
venturi/impingement tray tower wet scrubbing systems, sometimes augmented with WESP
systems.
Response: EPA is not prescribing a specific control technology or method. A source is
required to meet the final emissions limits in these standards, and has the flexibility to use the
control method or technology that is best suited for their individual facility. EPA's costs are
estimated based on technologies we believe may be appropriate for the sources to meet the
emissions limits. For the final rule we have re-evaluated control options for MACT floor
compliance and determined that for SSIs, venturi scrubbers or wet electrostatic precipitators
would be more appropriate than fabric filters for PM and metals control.
11.5 CO 100 ppmv Limit
Comment: Three commenters (76.1, 90.1, 97.1, 127.1, 129.1) supported EPA's decision
not to go beyond the floor for CO. Four commenters (76.1, 90.1, 97.1, 127.1, 129.1) noted
increase fuel usage, and NOX emissions, and three commenters (90.1, 97.1, 127.1, 129.1)
indicated additional greenhouse gas emissions, operational and maintenance costs, and capital
costs do not warrant a beyond the floor limit for CO. One commenter (76.1) supported EPA's
statement that an FB incinerator can meet the 100 ppm CO limit, but claimed that MH
incinerators could not meet a 100 ppm CO limit. The commenter argued that USEPA Office of
Water agreed with this conclusion, and revised 40CFR503 so that MHFs can meet a 100 ppm
Total Hydrocarbons (THC) emission limit in lieu of a 100 ppm CO emission limit. The
Response: For the final rule, EPA is not going beyond the floor for CO emission limits.
Section 129 of the CAA requires EPA to set limits for nine specific pollutants, and therefore
EPA cannot use THC as a surrogate for CO. The CO limits in the final rule are based on EPA's
revised UPL methodology, which is documented in the memorandum, "Revised MACT Floor
Analysis for the Sewage Sludge Incinerator Source Category" in the SSI docket (EPA-HQ-OAR-
2009-0559). The revised final CO emission limit for new FB units is 27 ppmvd and for new MH
units is 52 ppmvd. The revised and final CO limit for existing FB units is 64 ppmvd and for
existing MH units is 3,800 ppmvd. Please refer to the MACT floor UPL calculation and EG and
NSPS emissions limits section of the preamble for a detailed description of how these limits
were chosen. The final rule also allows 24-hour block averages for CO CEMS (which are
required at new sources), which should also help alleviate the commenters' concerns.
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EPA chose not to go beyond the floor due to increases in NOX and CO, cost, and energy
inputs. The analysis is documented in the memorandum "Revised Analysis of Beyond the
Maximum Achievable Control Technology (MACT) Floor Controls for Existing SSI Units" in
the SSI docket (EPA-HQ-OAR-2009-0559). The UPL includes facilities that reported greater
than 2200 ppm CO; these facilities complied with the OW 503 alternative THC limit and had
high CO concentrations. The high CO values from these facilities resulted in a calculated UPL of
3,800 ppmvd for existing MH units. EPA is required to set limits for CO for units regulated
under Section 129 of the Clean Air Act, and is not allowed to use surrogate compounds, such as
THC. States have the option to set limits more stringent than the emission guidelines and can set
lower CO limits.
11.6 CO Control
Comment: Two commenters (56.1, 64.1) supported the use of afterburners or a post-
scrubber RTO (or recuperative) afterburner to decrease CO emissions from MH incinerators.
One commenter (56.1) claimed the RTO or recuperative afterburner will not result in excessive
NOx emissions, referring to guarantees provided by RTO venders. The commenter (56.1) added
that the cost of the add-on is cost-effective and that life cycle costs are very reasonable when
operating fuel decrease is considered. The commenter (56.1) provided two facility examples
quoting emissions, equipment types, and costs. The commenter (56.1) noted that RTO systems
often include a wet electrostatic precipitator that has the added benefits of reduction of;
particulate matter, acid gas, and metals to greater levels than conventional scrubber/afterburners
on MH incinerators and the process is ideally suited for add-on dry mercury removal. The
commenter (56.1) stated afterburners on MH installation will remain for control of CO emissions
to 100 ppmvd or less.
Other commenters (76.1) agreed with EPA that an afterburner or RTO can reduce CO,
but at the cost of increasing NOX, fossil fuel usage and greenhouse gas emissions. The
commenters concluded that use of an afterburner or RTO to reduce CO will result in an
unacceptable increase in NOX emissions. The commenters (76.1) also stated that most SSIs can
meet the MACT floor limit for CO and NOX without additional modification. One commenter
noted that there will be substantial costs to incorporate the afterburner into an existing sewage
sludge incineration system and the existing air pollution control train will have to be modified.
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Response: After revising the emissions data set and associated default parameters based
on data corrections submitted during the comment period, EPA has re-evaluated beyond-the-
floor options for all pollutants and has decided to set the MACT floor limits as the standards.
EPA determined that it was not appropriate to go beyond-the-floor to achieve greater reduction
of the pollutants considering the cost and secondary impacts incurred. A full description of the
beyond-the-floor analyses can be found in the memorandum "Revised Analysis of Beyond the
Maximum Achievable Control Technology (MACT) Floor Controls for Existing SSI
Units"(EPA-HQ-OAR-2009-0559). EPA maintains that it is incumbent upon the SSI facility to
determine whether combustion conditions can be adjusted to meet standards for both CO and
NOX and, if not, install NOX controls as necessary (e.g., SNCR systems, SCR systems, FOR, or
low NOX burners). Please see Section V, Part E of the preamble for EPA's more detailed
response to these concerns. The beyond-the-floor analysis for CO was based on application of an
afterburner. We did not include cost estimates for RTOs given space considerations and higher
capital costs when compared to afterburner retrofits. The annualized cost for RTO's was
estimated to be four to six times the annualized cost of an afterburner.
Comment: One commenter (49.1) supported the use of improved solids dewater
equipment, such as high solids centrifuges, as a means to control CO and also reduce incinerator
fuel use. The commenter (49.1) referred to the Water Environment Federation, Incineration
Manual of Practice FD-19, 1992 quoting "the most significant factor affection the operating
economics of sludge combustion is cake solids concentration of the feed furnace." The
commenter (49.1) noted several examples of reduced fuel usage and cost savings related to
improved solids dewatering equipment. The commenter (49.1) pointed out that achieving
autogenous combustion may not result in less than 100 ppmv CO, but autogenous biosolids will:
1) Increase hearth 0 temperatures, 2) reduce the fuel use to dry biosolids and 3) any afterburner
fuel use required to achieve 100 ppmv CO. A benefit cost analysis by the EPA of using standard,
high solids centrifuges to reduce CO emissions incinerator fuel use (for drying and afterburners)
is needed. The commenter (49.1) also added that EPA should evaluate if any minimum hearth
zero temperature is required to protect the public health, on MH incinerators that would have
new scrubbers to reduce submicron particulates and metals. The commenter (49.1) also stated
that fuel savings achieved by FB incinerators are mainly due to changes in the dewatering
systems.
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Response: EPA thanks the commenter for their input. However, EPA lacks the cost and
performance data needed to evaluate the suggestion.
11.7 BTF for Other Pollutants
Comment: One commenter (76.1) supported EPA's decision that adding fabric filters
(FF) to reduce PM and Cd beyond-the-MACT-floor is not cost effective. The commenter (76.1)
also agreed that adding packed bed scrubbers to reduce HC1 and SO2 beyond-the-MACT-floor is
not cost effective. The commenter (76.1) concurred with EPA that beyond-the-MACT-floor
technology to reduce CO, NOX, and CDD/CDF is also not cost effective, and EPA's
determination that there will be no beyond-the-MACT-floor limits for HCI, SO2, PM, Cd, CO,
NOX, and CDD/CDF.
Response: EPA agrees with the commenter and thanks them for their support.
Comment: Commenters (79.1, 84.1, 119.1) argued that EPA should have set additional
beyond the floor limits for dioxins. The commenter (79.1) stated that since mercury controls will
bring about additional dioxin reductions, then it seems those controls are achievable for dioxins
too and EPA is therefore compelled to require them as MACT. One commenter (84.1, 119.1)
added that EPA must ensure that its standards reduce each of the pollutants enumerated in §
129(a)(4), including dioxins, by the maximum degree achievable. The commenter stated that if a
standard more stringent than the floor is achievable for any of these pollutants, EPA must set
such a standard and that standard must reflect the maximum degree of reduction in emissions
that is achievable; furthermore, EPA cannot dispute that dioxin standards more stringent than its
floors are achievable both technically and economically. Specifically, the commenter stated that
they can be achieved through the use of ACT which is already the basis for EPA's mercury
standard. The commenter (84.1, 119.1) noted because EPA found that the cost of ACT was
achievable for mercury alone, the incremental cost of using that same technology to reduce
dioxin emissions is zero.
The commenter further stated that failure to set beyond-the-floor standards is not
inconsequential; although many SSI will need to install ACT to meet the mercury standard, some
SSI will not. The commenter noted that these SSI will continue to emit more dioxin emissions
than would be allowed under a properly set beyond-the-floor dioxin limit. Furthermore, the
commenter stated that requiring sources to meet a specific dioxin limit and report compliance or
non-compliance with that limit in their Title V permits has far greater value in protecting public
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health and the environment than merely setting standards that will lead some sources to install a
control technology known to reduce dioxin emissions. The commenter specifically stated that
this would ensure that the reductions will actually happen.
Response: After revising the emissions data set and associated default parameters based
on data corrections submitted during the comment period, EPA has re-evaluated beyond-the-
floor options for all pollutants and has decided to set the MACT floor limits as the standards.
EPA determined that it was not appropriate to go beyond-the-floor to achieve greater reduction
of the pollutants considering the cost, secondary impacts incurred, and concerns regarding the
performance of beyond-the-floor technologies evaluated for this source category. EPA has
discussed the concerns regarding high moisture content streams from SSI's in previous
responses. The same issues for Hg control apply to dioxin/furan control. For other combustion
sources, carbon injection in combination with a FF has proven to be highly effective in removing
dioxin. However, we also agree that for high moisture flue gas streams, such as emitted from SSI
units, the use of FFs is problematic due to plugging/fouling. In order to use carbon injection with
a FF with high moisture streams, a waste heat boiler, RTO, or afterburner is necessary to
maintain a high enough temperature to keep the stream above the dew point prior to sending the
stream to the FF. Additional equipment may also be necessary to reduce the temperature of the
flue gas to prevent damage to the fabric filter bags. A full description of the beyond-the-floor
analyses can be found in the memorandum "Revised Analysis of Beyond the Maximum
Achievable Control Technology (MACT) Floor Controls for Existing SSI Units"(EPA-HQ-
OAR-2009-0559). Please see Section V, Part E of the preamble for EPA's more detailed
response to these concerns.
Comment: Commenters (79.1, 84.1, 119.1) argued that EPA is obligated to consider
beyond-the-floor options and should do more than perform "preliminary" costs analyses for
cadmium, lead, particulate matter and other pollutants. One commenter (79.1) claimed that EPA
noted it performed a "preliminary cost and emission reduction analysis" (page 63275) on
beyond-the-floor options for cadmium, lead, particulate matter and other pollutants and decided
not to further analyze fabric filter and packedbed options. Another commenter (84.1, 119.1)
added EPA rejected beyond the floor limits for cadmium, lead and particulate matter because
after conduction a preliminary analysis EPA determined that costs would be high and deemed the
reductions achieved not cost-effective. The commenter (84.1, 119.1) adds the test for beyond-
the-floor standards under § 129 is not whether EPA thinks the cost of a particular control
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technology is "high," but whether cost renders the application of that technology unachievable.
The commenter states that EPA does not even claim that cost renders the application of FF
unachievable for SSI, far less provide record evidence to support such a contention. The
commenter (84.1, 119.1) stated that EPA's failure to set beyond-the-floor standards for lead,
cadmium and PM based on the application of FF is unlawful and arbitrary. The commenter (84.1,
119.1) further stated that the test for whether a degree reduction is required by § 129 is not
whether the agency regards it as "cost-effective." Rather, the commenter asserts that the test is
whether EPA's floors do or do not reflect the "maximum" achievable degree of reduction. The
commenter argued that if EPA's standards do not reflect the maximum achievable degree of
reduction - i.e., if standards that would yield a greater degree of reduction are achievable - EPA
must set beyond-the-floor standards regardless of whether it views such standards as cost-
effective. The commenter asserted that the § 129 directive that EPA consider "cost" in
determining the maximum achievable degree of reduction does not authorize EPA to base its
beyond-the-floor decisions on cost-effectiveness considerations. The commenter argues that cost
and cost-effectiveness are different concepts, especially in the context of § 129's mandate that
EPA's standards reflect the "maximum" achievable degree of reduction. Specifically, the
commenter stated that § 129 allows EPA to consider whether a particular degree of reduction is
"achievable" considering cost - i.e. whether the means for achieving that reduction are too
expensive for the industry as a whole to achieve. The commenter argues that § 129 does not
allow the agency to replace Congress' mandate for the maximum achievable degree of reduction
with a far more subjective exhortation to set standards reflecting the degree of reduction that the
agency deems "cost-effective." The commenter (84.1, 119.1) noted EPA's failure to propose
beyond-the-floor standards for HC1 and SO2 based on the application of packed-bed scrubbers is
unlawful and arbitrary for the reasons given for cadmium, lead, and particulate matter.
Response: Please refer to the memorandum "Revised Analysis of Beyond the Maximum
Achievable Control Technology (MACT) Floor Controls for Existing SSI Units" (EPA-HQ-
OAR-2009-0559). EPA evaluated multiple controls but determined not to go beyond the floor,
based on costs and secondary impacts. Additionally, there are significant concerns with beyond-
the-floor technologies for this source category, such as the high moisture content of the flue gas.
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12.0 PERFORMANCE TESTING AND MONITORING REQUIREMENTS
12.1 Operating Ranges
Comment: Several commenters (129.1, 62.1, 115.1) stated that one or all of the proposed
operating ranges (15-minute data, 4-hr rolling average, limit established at 90% of average
value) for minimum pressure drop across each wet scrubber, minimum scrubber liquor flow rate,
minimum scrubber liquor pH, and minimum combustion temperature are too narrow and not
achievable. Other commenters (101.1, 85.1) stated that the scrubber pressure drop is not
achievable for facilities with fluctuating sludge feed. Two of these commenters (129.1, 62.1)
stated that the ranges will contradict with the operating parameters in 40 CFR 60 Subpart O, 40
CFR 503, State permits, and other permits. One commenter (129.1) stated that Subpart O allows
the pressure drop to be as much are 70% of the test results. One commenter (76.1) recommended
that EPA use the highest value of the three 1-hour runs to set the operating limit, as is allowed in
their existing Title V permit. Conversely, two commenters (101.1, 85.1) stated that the proposed
ranges for scrubber liquor flow rate and the minimum combustion temperature are achievable.
Response: EPA has determined that the operating limits are more appropriately based on
the maximum or minimum values rather than the average values recorded during the
performance test runs. The final rule requires that operating limits be established on a site-
specific basis as the minimum (or maximum, as appropriate) operating parameter value
measured during the performance test. This approach has been incorporated into the final rule for
all operating parameters and will result in achievable operating ranges that will ensure that the
control devices used for compliance will be operated to achieve continuous compliance with the
emissions limits.
Comment: One commenter (97.1, 127.1) is concerned that limiting the operating
parameter range to the range established during a single performance test can force a facility to
achieve emissions well below a limit, thus enforcing a more stringent limit. The commenter
(97.1, 127.1) stated that if a stack test confirms that emissions are 50 percent of the emissions
limit, the operating parameters derived from that test would be ensuring that emissions remain
controlled to 50 percent of the emissions limit during future operations. The commenter (97.1,
127.1) said that the operating parameter range should reflect the full range of operating
conditions that correlate with emissions up to the emissions limitation. The commenter (97.1,
127.1) stated that facilities should have the flexibility to determine the averaging period on a site-
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specific basis, developing a continuous compliance plan based on the stack test data and all other
available information regarding the correlation of operating parameters to control device
performance. The commenter (97.1, 127.1) stated that this ensures that the operating parameters
actually correlate to performance at the emission limit and not at the rate captured during the
stack test.
Response: EPA has determined that the operating limits are more appropriately based on
the maximum or minimum values rather than the average values recorded during the
performance test runs. The final rule requires that operating limits be established on a site-
specific basis as the minimum (or maximum, as appropriate) operating parameter value
measured during a single 4-hour run during the performance test. The results do have to be
during the most recent performance test. However, also EPA has revised the rule to waive the
operating limits during source testing so that sources may adjust their operating limits to provide
increased operating flexibility provided the emission limits are met. The intention behind
reassessing operating limits with new performance testing is to ensure that the limits remain
appropriate for the source. By allowing the source to conduct performance tests with less
stringent operating levels than may have been initially determined, the source will be able to set
the limits at levels appropriate for their operations while ensuring emission limits are met. This
approach has been incorporated into the final rule for all operating parameters and will result in
achievable operating ranges that will ensure that the control devices used for compliance will be
operated to achieve continuous compliance with the emissions limits.
Comment: One commenter (129.1) stated that the Part 503 regulations (governing the
design of all SSIs) require facilities to establish a site-specific maximum combustion zone
temperature, which is used to minimize the metal emission. The commenter (129.1)
recommended that EPA remove the minimum combustion temperature parameter because it is
not needed.
Response: The rule requires continuous parameter monitoring of control devices used to
meet the emission limits for Hg, Cd, and Pb, such that monitoring maximum temperature is not
needed to ensure that sources are meeting these limits. Minimum combustion temperature is
needed to establish that the SSI is achieving good combustion and meeting its CO limit on a
continuous basis.
Comment: Several commenters (75.1, 56.1, 137.1, 126.1, 118.1,85.1,76.1,67.1, 111.1,
62.1, 122, 123, 115.1,97.1, 127.1, 101.1, 109.1,96.1, 117.1, 129.1) argued that the operating
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range for sludge moisture content (daily composite of 3 samples taken 6 hours apart, limit
established at 10% above and below average level, 60.4870(k)) is not achievable because
moisture content is too variable. Many of these commenters (56.1, 118.1, 122, 123) stated that
sludge moisture is a parameter extremely sensitive to the type of dewatering equipment used by
the operator, and also to seasonal variation in the treatment process of the WWTP; it is not
uncommon for changes in sludge to occur monthly, weekly, and even daily. One commenter
(101.1) stated that their customer sludge ranges from 15% to 26% solids and blended sludge
during the most recent stack tests averaged 24.8% solids. The commenter (101.1) stated that in
order to keep the blended sludge between 22.3% and 27.3% it would require dewatering most of
their outside sludge in house which would require new receiving facilities. Another commenter
(126.1) stated that they incinerate a variety of dewatered cake and liquid sludge from outside
sources in addition to its own sludge produced at the River Road, Hopewell and Pennington
WWTPs; during 2009 their incinerated sludge varied from 15.3 to 23.3 percent total solids.
Another commenter (96.1) stated that their sludge cake varies in solids content from the low 20's
to over 50% depending on the variability of the volatile solids content; and the weather plays a
dramatic role in plant influent flow, with extended dry-weather flows under 100 mgd to wet-
weather flows over 200 mgd. Another commenter (97.1, 127.1) said that during storms and other
high flow events, the POTW is working hard to keep up with the influent and the sewage sludge
feed rates and moisture content are necessarily on the higher end of the normal range; during low
flow periods, SSIs may operate significantly below maximum feed rates with sewage sludge
moisture at the low end of the normal range.
One commenter (74.1) questioned the purpose of requiring a minimum percent sludge
moisture content, which could restrict the operator's ability to minimize use of auxiliary fuel. The
commenter (74.1) said that they are unable to comply with the proposed sludge moisture content
limits in §60.5190 and do not know what additional sludge treatment unit would need to be
constructed to comply with the limits. The same commenter (74.1) said that their most recent
performance test showed sludge moisture content varied from 38.4 to 47.8 percent, and older
tests (2009) showed daily sludge moisture content ranged from 18 to 52 percent. The commenter
(74.1) said that for their operation, only the wet weight is available to the operator on a real-time
basis, but the dry weight must be determined in the laboratory by drying a sample for a specified
time. The commenter (74.1) said the incinerator operator cannot control sludge moisture content,
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but can maintain incinerator operation within design parameters by feeding auxiliary fuel as
needed to maintain temperature and percent oxygen in an allowable range.
One commenter (56.1) said it is not feasible to obtain accurate sludge moisture results in
a timely enough period in order to make any attempts at adjusting the controls of the de-watering
equipment that would prevent deviations of 10% on any particular day. Another commenter
(109.1) said that requirements for sludge moisture content would essentially mandate CEMS due
to the frequency of occurrence of these variations in feed moisture concentrations and feed rates.
Many of these commenters (76.1, 85.1, 75.1, 111.1) requested EPA to delete the sludge moisture
range requirement since it serves no practical purpose. One commenter (76.1) recommended that
the compliance averaging period for the sludge moisture parameter should be daily. Another
commenter (56.1) recommended the restriction in deviation of 10% for sludge moisture should
be revised to state a deviation of no more than 10 percentage points (in other words if a SSI is
tested at 24% TS they should report deviations of 14% or 34% TS). Other commenters (137.1,
105.1) recommended using operating temperature in incinerator and the feed rate of mass of dry
solids instead of the sludge moisture parameter.
Response: The final rule does not require that SSI units maintain sludge moisture content
within specified ranges. EPA has determined that the operating limit for temperature of the
combustion chamber (or afterburner temperature) is sufficient to ensure good combustion
practice, and that moisture content is not needed to establish that SSI units are in compliance
with their emission limits. If a SSI has a higher moisture content, the SSI will need to use more
fuel to comply with their operating limit for temperature of the combustion chamber. We are
retaining the requirement to keep daily records of moisture contents, as SSI units should already
be keeping records of these parameters, and this information will be useful in establishing
representative operating limitations for a SSI unit.
Comment: Several commenters (101.1, 129.1,85.1, 118.1,76.1,62.1,97.1, 127.1)
pointed out that the proposed requirement for establishing the operating range (where the sludge
feed rate is required to be 110% of the average feed rate during the performance test) would
establish the facility's maximum feed rate at a value lower than the permitted max rate. One
commenter (118.1(13)) stated that Pennsylvania requires that performance tests be conducted at
85% of maximum capacity. Some commenters (123, 122, 118.1) state that charging the
incinerator at 75% to 90% of its rated capacity results in a much steadier state of control and a
more efficient combustion of the sludge, and in reality a greater ease of operation by the
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operators in charge of the equipment. Many commenters (101.1, 129.1, 85.1, 118.1, 76.1, 62.1,
96.1, 109.1, 115.1,97.1, 127.1) argued that the feed rate will not stay in the proposed window of
10%, such that the maximum capacity will be exceeded, resulting in deviations. Two
commenters (109.1, 96.1) stated that EPA fails to take into account the normal variation in feed
conditions and feed rates that occur on a daily, seasonal and wet weather dependent basis at any
POTW, much less one that processes significant flows from combined sewer areas like the City
of Indianapolis. The commenter (96.1) recommended that the maximum dry sludge rate be
removed from the proposed language and stated that emission limits can be maintained under all
conditions; even when significant changes to the feed rate have occurred. One commenter (76.1)
recommended that the maximum dry sludge rate be the rated capacity of the MHF, not a
percentage of the feed rate during the compliance demonstration source test (the unused capacity
in the MHF is needed for the future planned growth in their service area). Another commenter
(137.1) suggested that a "reduced capacity" operation such that the maximum capacity and
efficiency of the incinerator is documented and approved, but that the normal deviation of an
operating parameter by more than 10% during the reduced capacity is not considered a
"deviation" by the terms of the guidelines. One commenter (97.1, 127.1) suggested that the
operating and maintenance parameters be established in site-specific operating plans that focus
on the parameters that correlate with control device efficiency.
Response: EPA has reviewed its decision at proposal to require that SSI units maintain
the sludge feed rate of the incinerated sludge within specified ranges. For the reasons stated by
the commenter, we are no longer requiring that SSI units maintain the sludge feed rate within
specified ranges. We have determined that the operating limit for temperature of the combustion
chamber (or afterburner temperature) is sufficient to ensure good combustion practice. However,
we have added a requirement that performance tests be conducted at 85 percent of the permitted
maximum capacity. This level has been selected based on the performance test operating
information provided by the commenters and previous EPA standards. Sludge feed rate
information is necessary during performance test runs to establish that SSI units are in
compliance with the new requirement that they conduct performance tests at 85 percent capacity.
We are retaining the requirement to keep daily records of sludge feed rates, as SSI units should
already be keeping records of these parameters, and this information will be useful in
establishing representative operating limitations for a SSI unit.
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12.2 Data Averaging Periods
Comment: Two commenters (134.1, 76.1) agreed with the use of a 4-hour rolling
averaging time for monitoring of operating parameters. Two commenters (101.1, 126.1)
recommended that the proposed 4-hour rolling average period for operating limits be increased
to a 24-hr block average. The commenters (101.1, 126.1) stated that record keeping requirements
and compliance demonstrations are simplified when averaging is performed on a block rather
than rolling basis. Another commenter (76.1) requested 4-hour rolling averages for CEMS and 4-
calendar day rolling average for daily limits. One commenter (85.1) recommended that EPA
retain 24-hour block averages because 24-hour block averages are more accommodating of the
significant variability in the sludge cake feed to SSIs. Additionally, the commenter (85.1)
pointed out that 40 CFR 503 requirements for SSIs require 24-hour averages and stated that
changing the averaging period to 12 hours under this rule would increase the administrative
burden on SSI operators by requiring calculation and reporting in two different formats.
A few commenters (97.1, 127.1, 101.1, 126.1, 134.1, 129.1) responded to EPA's request
for comment on the proposed averaging period for determining compliance using a CEMS or
CASS. One commenter (134.1) agreed that the proposed use of a 24-hour block average for
reporting CEMS data is appropriate. The commenters (97.1, 127.1, 101.1, 126.1, 129.1)
indicated that the 24-hour averaging period was not long enough and should be increased to a 30-
day (or longer) period. One commenter (97.1, 127.1) explained that waste water influent has
significant and unpredictable variability due to unavoidable spikes in compound concentrations.
The commenter (97.1, 127.1) specified that high concentrations of mercury can be released when
segments of the sewer are periodically cleaned downstream of a dentist office where mercury-
containing amalgams are discharged into the sewer, and during for other periodic activities and
spills upstream. The commenter (97.1, 127.1) was concerned that these spikes are not reflected in
EPA's database for setting the MACT floor. The commenter (97.1, 127.1) pointed out that
POTWs do not have the option to refuse such discharges. Another commenter (129.1)
recommended that compliance with the operating limits be set on a monthly-daily average basis,
same as is required by the Part 503 Regulations. The commenter (129.1) recommended data
collection, recordkeeping, and averaging requirements be similar to those contained within the
Part 503 Regulations.
Several commenters (134.1, 80.1, 105.1, 137.1, 67.1) argued that the proposed CO
standard would be difficult to consistently achieve with an FBI (unachievable with a MHI) on a
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4-hr rolling average basis. The commenters (134.1, 80.1, 105.1, 137.1, 67.1) stated that a 24-hr
basis may be more realistic. Some of these commenters (80.1, 105.1, 137.1) said it may still
require increasing residence time in the freeboard to achieve 7.4 ppm. Commenters (76.1) urged
EPA to clarify what averaging time would apply to any given parameter.
Response: The EPA has determined that a 24-hour block averaging period for compliance
with the CO CEMS requirement for new sources will provide a sufficient indication of
compliance and will allow more flexibility for facilities. For other parameter limits, we have
adopted a 12-hour block average. This averaging period is generally consistent with the longest
anticipated source testing periods under this rule, and thus is appropriate for determining
continuous compliance. With respect to mercury spikes, we expect that mercury spikes to dental
amalgams will be less frequent due to the Office of Water's dental amalgam rule will be
proposed in 2011 or 2012 and local programs to control these discharges.
Comment: One commenter (76.1) argued that the use of a 24 hour block of data to
demonstrate initial compliance is excessive and adds substantially to the source test cost. The
commenter (76.1) stated that California Air Resources Board and the Bay Area Air Quality
Management Board use the average value of three, one (l)-hour sampling runs to show
compliance; a 3-hour source test costs approximately $3,000. The commenter (76.1) stated that a
24-hour source test will cost more than $24,000; and recommended that EPA require the average
of three 1-hour runs. One commenter (76.1) requested EPA provide justification for increased
monitoring costs because the costs per CEM are significant.
Response: EPA would like to clarify that CEMS are not required by the final rule except
to demonstrate continuous compliance with the CO limit for new sources. CEMS are optional for
all existing sources.
Comment: One commenter (134.1) stated that daily composites of three samples taken
six hours apart is acceptable for units operating on a continuous basis; however, for units that
may only operate on an intermittent basis, the timing of the three daily samples should be spread
roughly equally throughout the operating period, which may require sampling more frequently
than 6-hour intervals.
Response: We are no longer requiring that SSI units maintain sludge moisture content,
but are still requiring records of sludge feed rate.
Comment: One commenter (76.1) recommended that compliance with the maximum
MHF feed rate cannot be a 4 clock-hour average, but should a 10-day rolling average. The
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commenter (76.1) stated that this gives enough operational flexibility to deal with diurnal
influent flow variation as well seasonal influent flow variations.
Response: We are no longer requiring that SSI units maintain sludge feed rate within
specified ranges, and feed rate monitoring has been removed from the final rule.
Comment: One commenter (76.1) requested that EPA base compliance on a clock-hour
average and not on an instantaneous value from the opacity CEMS. The commenter (76.1)
argued that Opacity is measured by an observer recording opacity to the nearest 5% at 15 second
intervals; since most of the data was collected when the incinerators were running well, the
measured opacity was low and EPA's statistical method produced an opacity limit of 10%. The
commenter (76.1) stated that it has a very low opacity on average but the Title V operating
permit limit is 20% opacity for greater than 3 minutes out of every hour.
Response: We agree that a no visible emissions (zero opacity) limit for combustion
processes is impractical for both compliance and enforcement purposes. We also believe that a
measurable opacity may or may not be indicative of compliance with a PM emissions limit when
applied to multiple sources within the category. That is, an opacity limit applied to one facility
could very readily correspond to a PM emissions level different than that same opacity limit
applied to another facility and one or both may be emitting above the PM limit. That opacity
limits do not apply very well when wet control devices are used further confounds the benefit of
such regulatory limits. We also agree that there are both CEMS and site-specific parametric
monitoring approaches applicable to various control devices that can be more closely aligned
with PM control and compliance with the PM emissions limit than would an opacity limit and
opacity monitoring. Instead of establishing opacity limits that may or may not assure compliance
with PM emissions limits, the final rules include rigorous requirements for establishing site-
specific operating limits derived from the results of performance testing. The rules also include a
requirement that sources update those enforceable operating limits with each repeated
performance test. Re-establishing operating limits periodically will assure that the monitoring
will continue to indicate compliance with the PM emissions limits. The rules also provide the
source the option of apply CEMS to monitor directly the pollutant of interest in lieu of
parametric monitoring. We believe that continuous compliance with operating limits and
periodic stack testing to verify the operating limits plus the CEMS option will ensure that
sources demonstrate continuous compliance with the PM emission limits more effectively than
would periodic or continuous monitoring of a broadly applicable opacity limit.
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12.3 Testing Frequency
Comment: Many commenters (129.1, 90.1, 95.1, 109.1, 134.1, 85.1, 97.1, 127.1, 62.1)
disagree with the need for annual compliance testing. Several of these commenters (129.1, 90.1,
95.1, 109.1, 134.1, 85.1, 97.1, 127.1, 138) recommended that EPA require testing once every
five (5) years, matching the Title V requirements. Some commenters (129.1, 85.1) argued that
POTWs that have multiple incinerators (especially identical), may choose not to operate one or
more of their incinerators during a calendar year, and it will be very costly to place a non-
operating incinerator into service simply for an air emissions test. One commenter (129.1) stated
that the proposed frequency is based on hazardous and medical waste incinerator rules, and
argued that sewage sludge is not a hazardous material, nor a hospital, medical or infectious
waste. One commenter (97.1, 127.1) argued that POTWs are already subject to comprehensive
management practices, strict health-based sludge content limits, and NESHAPs under CWA §
405 and the Part 503 regulations, such that annual stack testing is not necessary to ensure
compliance with emission limits or reduce health risks. The commenter (97.1, 127.1) stated that
EPA requires performance testing less frequently than annually in several MACT rules, e.g.,
NESHAP for Coke Ovens: Pushing, Quenching, and Battery Stacks, 40 CFR. § 63.7321 (testing
twice per permit term); NESHAP for Lime Manufacturing Plants, 40 CFR. § 63.7111 (testing
every 5 years); NESHAP for Iron and Steel Foundries, 40 CFR. § 63.7731(a) (testing every 5
years).
Another commenter (95.1) is concerned that if EPA chooses to retain the annual
performance testing requirements, requirements to re-test or for an annual inspection every 10-12
months essentially shortens the year by a month every year. The commenter (95.1) suggested
that, at a minimum, EPA modify the regulatory language in §60.4895(a) and § 60.5215 to allow
annual testing and inspections to be 11-13 months. One commenter (121.1) is concerned that the
proposed frequency of testing required will be cost prohibitive. The commenter (121.1) stated
that compliance grade stack testing costs tens of thousands of dollars per emission point each
time testing is necessary to meet the proposed standards requirements. Another commenter (97.1,
127.1) is concerned that the cost for emissions testing may be significantly higher than $61,000
per unit that EPA predicted.
The same commenter (97.1, 127.1) supported less frequent emission testing when test
results demonstrate that a source's emissions are less than 75 percent of the applicable emissions
limits. However, the commenter (97.1, 127.1) stated that as explained in Part VILA, supra, the
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initial testing frequency should not exceed one test per permit term. The commenter (97.1, 127.1)
suggested that any final rule should provide for less frequent testing when the results are
sufficiently below the emission limit.
Response: The proposed standards included provisions for less frequent testing. Please
see Section V.H of the preamble for more detail.
Comment: EPA states that the proposed rule would allow for reduced testing of PM,
cadmium, lead, mercury, sulfur dioxide, hydrochloric acid, nitrogen oxides, and carbon
monoxides at better performing facilities to only once every three years. One commenter (54.1,
60.1) disagreed with this proposed approach. The commenter (54.1, 60.1) stated that stack HAP
concentrations shift continuously, particularly as a result of SSM-type events, so measurements
every three years, or even annually, are not sufficient to gauge the true impact of these facilities'
emissions on local and national air pollutant loads. The commenter (54.1, 60.1) argued that
research shows that many of the ambient air pollutants influence acute cardiac and pulmonary
function and excess short-term mortality (Chen and Lippmann, 2009); therefore, requiring
monitoring only every 3 years does not provide either an adequate assessment of short-term
emissions or acceptable protection of human health.
Response: The proposed standards included revised provisions for testing. Please see
Section V.H of the preamble for more detail.
Comment: One commenter (97.1, 127.1) supported allowing initial compliance
demonstrations to be based on earlier performance tests conducted prior to the rule if they
represent current operating conditions and used the appropriate test method. The commenter
(97.1, 127.1) suggested EPA not impose an arbitrary two-year cut-off period for the initial
performance test; any test that meets the above criteria should be accepted, including all
emissions testing conducted for the ICR.
Response: EPA has elected not to provide for this use of prior test results. Given the
expectation that there will be recurring testing under this rule, the allowance for prior test results
seems unnecessary as a general allowance. A source may seek a waiver of testing under the
general provisions of Part 60 and should also review EPA's "Clean Air Act National Stack
Testing Guidance" (dated April 27, 2009), which contains additional discussion on stack test
waivers.
Comment: One commenter (92.1, 104.1) suggested that EPA replace the term "within"
with "less than" in 60.5205(a)(3)(iii). The commenter (92.1, 104.1) stated that under
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60.5205(a)(3)(ii), SSI units that demonstrate compliance at less than 75% of the limit or standard
may be allowed to reduce the frequency of performance testing to once each third year or 36
months; and under 60.5205(a)(3)(iii), any SSI unit where the most recent performance test
exceeds 75% of the emission limit for any pollutant must conduct annual performance tests for
that pollutant until all performance tests over the next three years for that pollutant are "within"
75% of the applicable emission limit. The commenter (92.1, 104.1) stated that the intent is to
perform testing for the pollutant of interest annually until the SSI unit has emissions "less than"
75% of the emission limit or standard.
Response: The language of 60.5205(a) has been updated to reflect the revised provisions
for testing. Please see Section V.H of the preamble for more detail.
12.4 Definition of "Process Change"
Comment: Numerous commenters (74.1, 96.1, 134.1, 112.1,87.1, 129.1, 118.1, 122)
argued that EPA should remove the language that defines a process change as "an increase in
allowable wastewater received from an industrial source to the wastewater treatment facility".
One commenter (101.1) stated that the magnitude of what constitutes a change needs to be
defined. Some commenters (101.1, 118.1, 134.1) are concerned that the proposed language
requiring a repeat of a performance test is vague and open to misinterpretation from state and
local authorities. The commenters (101.1, 118.1, 134.1) stated that EPA needs to provide more
definition, and/or clarification and examples. One commenter (121.1) asked whether it was
EPA's intention that the Proposed Standards will require a new performance test each time that
flow from an industrial discharger to an SSI changes. Some commenters (74.1, 96.1, 134.1,
112.1, 87.1) argued that the proposed requirement to retest and update the SSI monitoring plan
whenever allowable wastewater discharges from industrial users are increased would create
redundant regulation to the National Pretreatment Regulations at 40 CFR 403, which are
incorporated into the National Pollutant Discharge Elimination System (NPDES) permit issued
to their wastewater treatment facilities. The commenters (74.1, 96.1, 134.1, 112.1, 87.1) stated
that National Pretreatment Regulations require them to establish local limits on industrial
discharges to prevent interference with sludge processes, use or disposal; therefore, they would
not allow increases in industrial wastewater discharges to the wastewater treatment facility that
would cause a violation of rules governing the SSI. Two of these commenters (112.1, 87.1)
argued that given that industrial users are required to comply with local limits and that local
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limits are periodically updated to ensure that the POTWs meet all applicable limits, including air
emission limits that apply to incinerators, it is unnecessary to require retesting of SSI emissions
or modification of the air monitoring plan due to increased permitted discharges from a particular
industrial user. One commenter (74.1) argued that requiring performance tests to be repeated
because of an increase in the allowable wastewater received from an industrial source would be
very burdensome. The commenters (74.1, 129.1) stated that industrial wastewater that discharges
to their wastewater treatment facilities only constitute a small percent (<8%) of total influent
flow. The commenter (74.1) stated that these industrial sources (for example, a food processing
facility) do not discharge the pollutants that would be regulated under the proposed SSI rule;
therefore, an increase in the allowable industrial wastewater from these sources would not affect
SSI air emissions. One commenter (118.1) said that the existing 503 regulations regarding the
limits on concentrations of pollutants in the sludge feed to the SSI are sufficient to encompass
any changes in the POTW's industrial waste. Other commenters (118.1, 122) argued that most
industrial sources do not change their process quickly, and the requirement for annual
performance testing would already account for changes; and some industrial sources can make
small changes on a seasonal basis (many of these changes are temporary, such as a food
processor increasing its production of apple juice in the autumn). One commenter (62.1) stated
they would not be able to consistently comply with a new performance test if flow from an
industrial discharger changes because there is no way to anticipate industrial loads ahead of time.
Another commenter (121.1) is concerned about the frequency and costs associated with the
performance tests that would be necessary anytime a significant industrial user increases the
amount discharged to the sanitary sewer system.
Other commenters (105.1, 137.1, 109.1) argued that the proposed requirement to repeat a
performance test if there is a "change to the process employed at the wastewater treatment
facility that affects the SSI unit", or "an increase in the allowable wastewater received from an
industrial source to the wastewater treatment facility" is unreasonable for merchant facilities
which accept sludge from regional wastewater treatment plants or POTWs which also accept
outside sludge to facilitate operating their SSI closer to its design capacity (to achieve greater
efficiency and lower operating costs). The commenters (105.1, 137.1) stated that the critical item
with regard to changes to the system is whether the amount or quality of the sludge being burned
is substantially different, not whether the process from which the biosludge is generated or the
source of the wastewater treated has a larger flow or load. The commenters (105.1, 137.1) said
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that wastewater treatment plants and associated SSIs are generally designed with additional
capacity and POTW's with SSI have plans for other sludge disposal options for situations when
their systems are down or otherwise unable to handle the sludge. The commenters (105.1, 137.1)
argued that as long as the SSI is within its system capacity for sludge dry mass and the sludge is
typical for wastewater treatment plant, additional stack testing is unwarranted.
Response: EPA has reviewed the definition of "process change" and agrees with the
commenters that there are some situations where an increase in the allowable wastewater
received from an industrial source should not trigger a performance test. We have revised the
definition of "process change" to more specifically and clearly identify the type of process
change that will trigger a performance test. The revised definition identifies a "process change"
as pollutant-specific and as including only situations where the SSI has undergone a significant
permit revision. This revision will ensure that facilities retest whenever they have a significant
change in the process that could trigger higher emissions of a given pollutant.
Comment: One commenter (51.1) stated that the proposal did not require a repeat
performance test at a SSI unit that decides to process other solid wastes. The commenter (51.1)
recommended that EPA include a requirement for repeat performance testing in those instances
where significant material changes (which should be defined) in the waste feed to a SSI unit have
occurred.
Response: See the updated definition of "process change". The revised definition
identifies a "process change" as pollutant-specific and as including situations where the SSI has
undergone a significant permit revision. If there is a significant change to their NPDES permit,
they must retest.
12.5 Waste Management Plan
Comment: Several commenters (96.1, 97.1, 127.1) supports EPA's conclusion that
requiring waste management plans under §129 would be duplicative of the waste management
practices already in place under the CWA. Another commenter (134.1) argued that that the intent
of the Waste Management Plan used in previous §129 standards is not relevant to SSI units and
should not be required. Other commenters (96.1, 129.1, 137.1) stated that they do not see the
need for a waste management plan for SSI units. The commenters (134.1) stated that these plans
relate more to solid waste incineration systems, where the feed can actually be separated prior to
processing than to a POTW, where all incoming materials are co-mingled on a molecular level.
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The commenter (134.1) stated that there are many jurisdictions that have implemented
pretreatment ordinances or plans and some with active source control programs to reduce the
discharge of various metals to the POTW, most notably Hg source control programs; these
programs have been extremely effective in gradually reducing the levels of metals in the SSI
feed stream over the past decades. Two commenters (96.1, 137.1) asserted that SSI units are
required to meet EPA's OW part 503 standards for daily average concentration limits for Pb, Cd
and other metals and that POTWs are required to establish pre-treatment standards and discharge
limits for non-domestic users. The commenters (96.1, 137.1) are of the opinion that, given the
Part 503 pre-treatment standards, the requirement for a waste management plan is unnecessary
and would cause redundant reports and paperwork.
Response: EPA thanks the commenters for their input; the final rule does not require a
waste management plan. We have determined that operator training is sufficient.
12.6 Annual Visible Emissions Test
Comment: Two commenters (105.1, 137.1) recommended that if there is a wet ash
removal system as part of the incinerator system, it should be exempt from the annual visual
testing of ash handling procedures. The commenters (105.1, 137.1) argued that if an incinerator
system is using a wet ash removal system, an annual visual emissions testing provides no
operational value and adds unnecessarily to the reporting burden of the facility.
Response: The general provisions provide for waivers of stack testing under certain
conditions and EPA's national guidance on stack testing provides further information on stack
testing waivers. EPA does not believe this situation as described warrants a complete removal of
such systems from the testing requirements. Given the expected low readings from this test, this
type of operation may well qualify for reduced testing based on one test (see section V.H. of the
preamble for more detail).
Comment: One commenter (134.1) stated that annual visual testing of ash handling is
burdensome and recommended that EPA change the testing frequency to every 5 years.
Response: EPA has revised the testing requirements in the final rule (see section V.H of
the preamble for more detail). In the final standards, owners or operators are required to establish
that emissions of a given pollutant are under a specified threshold for two consecutive years,
rather than three years as proposed, to qualify for less frequent testing for that pollutant. For
fugitive emissions from ash handling, less frequent testing is allowed as long as visible emissions
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of combustion ash occur less than or equal to two percent of each Method 22 hourly observation
period (the standard is five percent of each of three hourly observation periods).
Comment: One commenter (76.1) argued that Method 22 is not appropriate for
determining opacity for ash truck loading operation because the sky is usually obstructed either
by equipment or the truck itself. The commenter (76.1) stated that they have alarm devices on
ash handling baghouses to indicate bag failure (and their bag houses are either inside a building
or do not have an unobstructed view of the sky), so Method 22 is not practical. The commenter
(76.1) recommended EPA change the wording that Method 22 visible emission test will be used
when there is a clear emission point with an unobstructed view of the sky. The commenter (76.1)
stated that if the ambient conditions are not suitable to use Method 22, best professional
judgment must be used to determine if the ash loading operation is creating a nuisance.
Response: The general provisions provide for waivers of stack testing under certain
conditions and EPA's national guidance on stack testing provides further information on stack
testing waivers. EPA does not believe this situation as described warrants a complete removal of
such systems from the testing requirements. Given the expected low readings from this test, this
type of operation may well qualify for reduced testing based on one test (see section V.H. of the
preamble for more detail).
Comment: One commenter (49.1) argued that control of fugitive ash emissions is
essential; and stated that the EPA regulations need to differentiate between ash handling and flue
gas systems that operate under 'negative pressure' and 'positive pressure'. The commenter (49.1)
stated that an ash leak, when the system is under pressure will result in a very visible plume of
ash discharge to the atmosphere. The commenter (49.1) urged EPA to model and measure how
much ash is discharged to the atmosphere, with an ash system or flue gas system is under
pressure and leaking into the air. The commenter (49.1) stated that the ash piping for a positive
pressure system needs to be visually checked more frequently than once a year; and
recommended at least once per shift (8 hours). The commenter (49.1) also recommended EPA
consider requiring a system shut down immediately, if a bad ash leak occurs. The commenter
(49.1) cited the WEF 'Wastewater Solids Incineration Systems' Manual of Practice, 2009, page
184 concerning ash pressure systems where it states "Even small leaks can result in substantial
amounts of dust." The commenter (49.1) is concerned that after a community spends millions of
dollars on new state-of-art electrostatic precipitators, bag filters, incinerators etc., a few small
pipe leaks let the particulates back into the atmosphere.
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The commenter (49.1) stated that when a system is under negative pressure, an ash leak
may or may not result in any visible discharge. The commenter (49.1) stated that they worked in
a MH facility for 8 years, where the MH incinerator, off-gas system and ash handling pipes were
under negative pressure; during the monthly shutdown, the ash pipes had to be checked by
listening for air leaks because ash would not always fall through the leaking pipe. The
commenter (49.1) suggested that the major ash problem on a MH system is ash hopper plug-ups,
at the bottom of the incinerator.
The commenter (49.1) recommended that for any new FB incinerator, the EPA needs to
require that a cyclone be installed immediately after the FB incinerator because the cyclone
should remove about 75% to 85% of particulates prior to any heat exchanger, to prevent
unneeded abrasive wear on heat exchanges and the off-gas system. The commenter (49.1) stated
that there is no need to have tons of abrasive ash discharge through expensive heat exchangers
and create holes in a positive pressure system; thus resulting in ash leakage into the building. The
commenter (49.1) cited the Water Pollution Control Federation Incinerator Manual of Practice,
OM-11, 1976 page 189: "...fluidized bed furnaces may benefit from the installation of a cyclone
at the exhaust to catch the large amount of ash (nearly 100% of the normal sludge ash content)
and that portion of the bed that is continually exhausted. Cyclones are relatively inexpensive and
removal of paniculate matter prior to further treatment in other processes will reduce the loading
to these control devices."
Response We agree that ash handling system integrity is an important component of the
dust control measures necessary for compliance with the rule. The installation and
implementation of equipment and procedures for maintaining and protecting process equipment
an important to this end but site-specific designs and operating criteria or adherence to industry
standards are not elements that the rule can or should address. These are practices that the source
owner should take into account in designing and constructing or remodeling the facility to meet
the applicable requirements. What the rule should and does require is that the source owner
verify that the measures necessary to limit the amount of fugitive dust exiting the transfer points
and exhausts from the building are such that they meet the visible emissions standard. The
visible emission limit does apply at all times even though the requirement for compliance tesitng
applies annually (unless the source qualifies for less frequent testing option - see other
comments). The revised rule also requires that the source provide a monitoring plan that should
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include frequent equipment inspections and even visible emissions checks to assure ongoing
compliance.
12.7 Daily CPMS Pressure Tap Checks
Comment: Several commenters (118.1, 97.1, 127.1, 122, 123) argued that daily CPMS
pressure tap checks are unrealistic, and in some cases, could cause the automatic safety shut
down of the incinerator. The commenters (118.1, 97.1, 127.1, 122, 123) stated that much of the
equipment associated with monitoring operational parameters have associated safety protocol
limits and values programmed into the system's operating control philosophy. The commenters
(118.1,97.1, 127.1, 122, 123) are concerned that disconnecting the equipment from the tap may
result in the equipment sensing an operational or mechanical failure, and can shut the system
down for correction. The commenters (118.1, 97.1, 127.1, 122, 123) stated that to do this every
day while burning sludge would be problematic, potentially resulting in reportable malfunctions
and/or bypasses. The commenters (118.1, 97.1, 127.1, 122, 123) stated that their experience has
indicated that these taps do not clog regularly and do not require daily disassembly. The
commenters (118.1, 97.1, 127.1, 122, 123) recommended to do these checks on a monthly basis
when calibrations are performed. Another commenter (76.1) requested EPA delete the daily
pressure tap check requirement because that they use a control system that checks pressure
measurements every second; and if the measurement goes out of normal operating range an
alarm rings and the operator responds appropriately.
Response: EPA is no longer requiring daily pressure checks. Instead, you must ensure
continuous acceptable operation of the pressure monitoring device (e.g., check for or provide
high reverse gas pressure periodically to minimize pressure tap pluggage). EPA desires to avoid
situations where facilities cannot meet a limit due to the control device failing because of the
pressure reading.
12.8 Cleaning and Calibrating
Comment: Three commenters (76.1, 122, 95.1) stated that it is unreasonable for EPA to
require pH meters to be calibrated on at least two points every 8 hours of process operation. The
commenter (76.1) requested EPA revise the pH probe process to monthly calibration checks. The
commenter (122) requested EPA require only daily calibration of a pH meter. Another
commenter (95.1) argued that the length of time between checking the calibration of a pH meter
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is site-specific and the unit should have flexibility to determine a frequency of calibration based
on the historical experience without EPA prescribing a one-size-fits-all frequency. The
commenter (95.1) stated that a set frequency for all instruments regardless of the sophistication
of the instrument and regardless of the service environment for the instrument is not appropriate.
The commenter (95.1) asserted that companies that have gone to the expense of using
sophisticated instruments such as smart transmitters and other instruments with self-diagnostics
as opposed to continuing to use older, less sophisticated systems would not benefit from
upgrading their systems. The commenter (95.1) also argued that it is improper to propose
continuous monitoring system requirements in the SSI proposal (§60.4509 of Subpart LLLL and
§60.5225 of Subpart MMMM) while continuing to work on a new CPMS proposal; the
commenter stated that EPA withdrew this rule (which was proposed on October 9, 2008 -
Performance Specification and Quality Assurance Requirements for Continuous Parameter
Monitoring Systems and Amendments to Standards of Performance for New Stationary Sources;
National Emission Standards for Hazardous Air Pollutants; and National Emission Standards for
Hazardous Air Pollutants for Source Categories or the "CPMS Rule"). The commenter (95.1)
requested that EPA remove the prescriptive requirements related to continuous monitoring
systems.
Response: EPA has revised the rule to require daily calibration. We have determined that
daily calibration should be adequate to assure compliance, although some facilities may want to
calibrate more frequently. The frequency of calibration is determined by the actual pH. Facilities
may request an alternative monitoring frequency under the Part 60 general provisions (and under
this rule) if they want to calibrate less frequently.
Comment: Two commenters (134.1, 76.1) requested EPA revise the proposed rule to
allow the use of solid state calibrators or manometers for annual pressure gauge and transducer
calibration checks.
Response: EPA does not require the use of a specific instrument used to perform gauge
and transducer calibration checks in the final rule, provided that quarterly and transducer
calibration checks are performed monthly.
Comment: One commenter (76.1) requested that EPA revise their accuracy requirements
to the standard of full scale reading. The commenter (76.1) stated that temperature sensors are
not rated on the value, but on the full scale; for example, a thermocouple could be accurate to ±
1% of full scale of 2000°F or ± 20°F for any reading.
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Response: EPA disagrees. The standard is adequate as written. Sources can get a precise
temperature measurement and ensure the thermocouple is within 1% of the temperature during
the performance test.
Comment: One commenter (76.1) requested that EPA revise the requirement to calibrate
temperature devices every 3 months to annual calibration or per manufacturer's recommendation.
Response: EPA disagrees. This is a simple measurement, especially if there redundant
devices (EPA expects this for some SSIs). If they want to request an alternative compliance
schedule, they can request this under the General Provisions 60.13.
12.9 Alternative Initial Accuracy Determination Procedure
Comment: One commenter (54.1, 60.1) provided comments on the alternate initial
accuracy determination procedure similar to one described in Section 11 of Performance
Specification 15; i.e. dynamic spiking. The commenter (54.1, 60.1) stated that it had over six
years experience using a similar procedure for multi-metal CEMS initial installation and on-
going quality assurance audits (OTM-16, 18, 21). The commenter (54.1, 60.1) recommended the
continued use of OTM-16 and a quantitative aerosol generator (QAG®) for initial certification
and on-going quality assurance audits of multi-metal CEMS; the QAG® is capable of
challenging a CEMS with a wide range of concentrations that can cover the range of short term
stack concentration variability as well as emission standards. The commenter (54.1, 60.1)
recommended the continued use of the QAG® for initial certification and on-going quality
assurance audits. The commenter (54.1, 60.1) does not recommend that EPA require use of EPA
Method 29 for initial certification or periodic audits of multi-metals CEMS because Method 29 is
less precise and less accurate than the QAG© and contemporary multi-metals GEMS; Method 29
would require emissions be in the dynamic range of both measurement's methods; Method 29
generates hazardous waste in both the sampling and analysis steps; and unlike the QAG©,
Method 29 does not allow for on-site determination of certification/acceptance (instead, Method
29 requires four to eight weeks for results). The commenter (54.1, 60.1) stated that if the CEMS
were to fail, an additional Method 29 audit would be required to repeat a relative accuracy test
audit.
Response: The alternative initial accuracy determination procedure for multimetals
CEMS are not promulgated. When they are promulgated, they will address this comment and
include these recommendations.
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Comment: One commenter (54.1, 60.1) does not recommend using draft Performance
Specification 10 (PS-10) because it is not consistent with contemporary CEMS technology and
requires relative accuracy test comparisons to a reference method (Method 29), which is
generally less precise and less accurate than contemporary CEMS and reference aerosol
generators. The commenter (54.1, 60.1) stated that the reference method (RM) is based on
concentrations present in the typical stack gas, which may be at or near the reference methods
detection limits and thus not be appropriate for comparison with a candidate method. The
commenter (54.1, 60.1) stated that PS-10 does specify the multi-metal CEMS must be capable of
measuring the total concentrations of the metals including Hg. The commenter (54.1, 60.1)
agrees with this aspect of PS-10 and encourages the EPA to require the same of all multi-metals
CEMS as well as mercury CEMS and RM.
Response: The alternative initial accuracy determination procedure for multimetals
CEMS are not promulgated. When they are promulgated, they will address this comment and
include these recommendations.
12.10 Sludge Content Monitoring as Alternative to Stack Test
Comment: Three commenters (75.1, 76.1, 97.1, 127.1) commented on using sludge
concentrations for compliance with the EG and NSPS limits. One of these commenters (75.1)
said that they feel that this option would make compliance and monitoring much less expensive
for those POTWs who operate Industrial Waste Pretreatment Programs. Two of these
commenters (76.1, 97.1, 127.1) urged EPA to adopt content monitoring of sewage sludge as an
alternative to annual testing or continuous emission monitoring for all pollutants for which a
correlation can be established between emissions and sludge content. One of these commenters
(76.1) stated that 40 CFR 503 already allows for Pb and Cd compliance based on sludge content;
the commenter requested EPA add Hg to this list through the proposed 129 regulations because
the feed sludge concentrations provide a consistent monitoring point and resulting in known
loading values to the SSI, annual source testing could be utilized to verify consistency with the
monitored Hg loading and calculated removal efficiencies for any new treatment devices
installed for the first five (5) years of operations, and if consistency is proven, annual source
testing for Hg discontinued after the five year timeframe. The commenter (76.1) stated that
monitoring Hg in the sludge over-estimates the incoming mercury to the plant by approximately
35% because of recycled Hg from scrubber water. Another commenter (97.1, 127.1) stated that
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EPA's Office of Water regulates the average daily sludge content of cadmium, lead and mercury
to ensure that SSI emissions stay below the health-based standards set under Part 503. The
commenter (97.1, 127.1) stated that Part 503 requires a stack test to set the control efficiency of
the control device for each metal; POTWs monitor the sludge feed and the moisture content and
use this data to calculate the average daily sludge feed rate in dry tons per day. The commenter
(97.1, 127.1) stated that POTWs also calculate a monthly average concentration of each pollutant
based on all the sludge samples taken in a month. The commenter (97.1, 127.1) urged EPA to
offer this approach to demonstrating compliance as an alternative to the PM surrogate limit in the
Proposed Rule. The commenter (97.1, 127.1) argued that the Part 503 sampling procedure is
something their members are familiar with and it will decrease the burden associated with
complying with this new rule. The commenter (97.1, 127.1) stated that sludge sampling is a cost-
effective way for units already regulated under Part 503 to demonstrate compliance with mercury
emission limits, and is significantly less burdensome than installing and maintaining CEMS or
performing annual stack tests. The commenter (97.1, 127.1) also supported using content
monitoring for other pollutants (SO2, NOx, HC1) for which a correlation can be established
between the content of the sewage sludge and the incinerator emissions. The commenter (97.1,
127.1) provided an example where SO2 stack testing with concurrent sulfur content monitoring
can be used to establish a correlation between sludge concentration and emission rate.
Response: Section 129 of the CAA requires EPA to set emission limits for pollutants
and demonstrate continuous compliance with the emission limits. For some pollutants,
monitoring sludge content may be a viable means of compliance. But for other pollutants, such
as CO, PCDD/PCDF, and NOX, monitoring sludge content is not indicative of the emissions.
EPA needs more data in order to allow the compliance option suggested by the commenters.
12.11 Other Performance Testing and Monitoring Concerns
Comment: One commenter (51.1) stated that they are aware of SSI units that accept and
combust sewage sludge from other WWTPs. The commenter (51.1) is concerned that this
practice is not addressed in the proposed requirements. The commenter (51.1) wanted to know
how variable feed stocks should be handled relative to performance testing. The commenter
(51.1) also asked whether the performance test represents the worst-case sludge composition, the
sludge combusted in the highest quantity, or perhaps a weighted average?
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Response: Any amount of sewage sludge combusted in an incinerator located at a
wastewater treatment facility designed to treat domestic sewage sludge is subject to the final SSI
standards. SSI units are expected to have variable sludge compositions throughout the year due
to seasonal changes and changes in the population generating wastewater. We do not believe its
necessary, or even possible, to specify that performance tests represent specific sludge
compositions.
Comment: One commenter (95.1) is concerned that EPA has proposed some emission
limitations that are beyond the ability of the referenced test methods. The commenter (95.1)
stated that Analytical Perspectives (a CRWI Associate Member and one of the laboratories that
analyze dioxin/furan samples), prefers to work at a level of quantification (LOQ) of 14.5 TEQ
pg/dscm for dioxin and furan samples. The commenter (95.1) stated that this is based on a
sample time of three hours drawing a cubic meter per hour; the proposed dioxin/furan standard
for new sources is 2.2 pg/dscm. The commenter (95.1) stated that to meet the LOQ for these
units, a new sewage sludge incinerator would have to sample approximately 20 hours (14.5 + 2.2
x 3 hours); while this is technically possible to accomplish, it runs into two practical problems.
The commenter (95.1) stated that one problem is the OSHA restrictions for working greater than
16 hours at a time (in addition, the time to complete 20 hours of sampling is actually longer than
20 hours, considering the time to reach steady state conditions). The commenter (95.1) stated
that the second problem is that it would be very difficult to keep the unit at constant conditions
for over the 60 or more hours (three test runs to make a valid test condition) required to show
that a unit would meet this standard.
Response: We disagree with the commenter about the conclusion that testing to show
compliance with a mass emissions limit for dioxin and furans for this rule would require
extraordinary sampling volumes and sample times. Although a laboratory may have a preferred
level of quantitation (or other similar laboratory-derived reporting limit), this approach is at odds
with the guidance we provided with the information collection request and with the reference test
method. EPA's guidance to respondents for reporting pollutant emissions used to support the
data collection specified the criteria for determining test-specific method detection levels, as
required in Method 23 for measuring dioxin and furan concentrations (section 9.8), not arbitrary
laboratory reporting levels. The final rule clarifies and reiterates the need to report D/F emissions
concentration as prescribed in Method 23, on a mass basis and to follow the method's procedures
for reporting values measured below the test-specific minimum detectable limit
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Comment: One commenter (134.1) stated that most SSIs have a once-through water
system, and pH is already measured and regulated under the NPDES permit so is not required in
the proposed rule.
Response: We are not requiring pH testing of the discharge effluent; rather, we are
requiring pH testing of the scrubber liquid.
Comment: One commenter (84.1, 119.1) argued that EPA must require actual emissions
monitoring and not just parameter monitoring. The commenter (84.1, 119.1) cited the Clean Air
Act and stated that §129 unambiguously requires EPA to establish actual emissions monitoring
requirements for SSI (see 42 U.S.C. § 7429(c)). The commenter (84.1, 119.1) stated that EPA's
regulations must require the owner of each unit "to monitor emissions from the unit at the point
at which such emissions are emitted into the ambient air (or within the stack, combustion
chamber or pollution control equipment as appropriate) and at such other points as necessary to
protect health and the environment." The commenter (84.1, 119.1) stated that §129 provides that
EPA's regulations must require owners to "monitor such other parameters relating to the
operation of the unit and its pollution control technology as the Administration determines are
appropriate." The commenter (84.1, 119.1) argued that despite the § 129's plain mandate for
actual emissions monitoring, EPA proposes to require only annual emissions testing and
parameter monitoring. The commenter (84.1, 119.1) argued that given that actual emissions
monitoring systems are available for SSI, the agency's failure to require actual emissions
monitoring and to require only parameter monitoring is flatly unlawful. The commenter (84.1,
119.1) stated that if Congress had intended EPA to require only parameter monitoring, it would
not have directed EPA to require actual emissions monitoring as well as any appropriate
parameter monitoring.
Response: We are requiring emissions testing for all pollutants, with the option of CEMS
or continuous sampling. In addition, we require parameter monitoring. In some cases, such as
dioxin/furan monitoring, CEMS are not available for accurate monitoring. In these cases, we use
CPMS to document continued operation of a source or control equipment in the same manner
that occurred during the last performance test to ensure continuous compliance.
Comment: One commenter (97.1, 127.1) supported flexible compliance options
allowing, but not mandating, CEMS for demonstrating compliance. The commenter (97.1, 127.1)
also supported allowing sources to propose site-specific operation and maintenance plans with
procedures for addressing missing CEMS data. The commenter (97.1, 127.1) stated that
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providing small entities with a choice of compliance options is particularly important, as it will
allow each POTW to independently assess which compliance option is most economical for that
facility.
Response: EPA has revised the final rule. We are not requiring CEMS (with the
exception of CO CEMS for new units); rather, CEMS are an optional method of compliance. We
are requiring annual compliance testing and continuous parametric monitoring, with CEMS and
continuous sampling with periodic sample analysis as approved alternatives. We have not
included provisions to address missing data for concentration limits. While these are sometimes
required for other emission limit formats (mass limit), they are not used in this rule.
Comment: One commenter (76.1) stated that EPA must acknowledge that reference
methods for HCI, PM, Pb, and Cd are wet chemical methods and are not designed for 24 hours
per day/7 days per week operation. The commenter (76.1) suggested EPA allow CEMS for NOX,
CO, and SO2 in lieu of annual source testing; however, since CEMS, Integrated Sorbent Trap
Dioxin Monitoring System (ISTDMS), or Integrated Sorbent Trap Mercury Monitoring System
(ISTMMS) are unproven for HCI, Cd, PM, and Pb, EPA should delete these as options and only
utilize annual source test requirements to quantify these parameters. Another commenter (129.1)
stated that EPA must realize that with the exception of CO, the remaining CEMS (Cd, HCI, NOX,
PM, Pb, or SO2) have never been successfully used to continuously monitor SSIs' exhaust stack
gases due to the high moisture content of the exhaust gases and other interferences. Another
commenter (121.1) argued that due to the high moisture content of SSI stack gases it is
understood that measurement of a number of the pollutants listed in the proposed standards
through a CEMS would be erroneous due to potential interferences.
Response: EPA disagrees. There are instruments available that operate with minimal
interference from moisture. Moisture is a problem with COMS, and possibly with PM CEMS but
these are not required by the rules. For existing SSI units, use of Cd, CO, HCI, NOX, PM, Pb or
SO2 CEMS; ISTMMS; and ISTDMS (continuous sampling with periodic sample analysis) are
approved alternatives to parametric monitoring and annual compliance testing. For new SSI
units, CO CEMS are required, and use of Cd, HCI, NOX, PM, Pb or SO2 CEMS; ISTMMS; and
ISTDMS (continuous sampling, with periodic sample analysis) are approved alternatives to
parametric monitoring and annual compliance testing.
Comment: One commenter (134.1) disagreed with EPA proposing that the bypass stack
be monitored because bypass stacks are only found on multiple hearth incinerators and are
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typically only used during emergency malfunctions (loss of power). The commenter (134.1)
stated that solids are not fed during startup and shutdown periods, and only burner emissions
would be measured. One commenter (122) stated they were unclear to what extent the bypass
stack must be monitored (including what parameters). The commenter (122) asked whether SSIs
are required to install expensive continuous emissions monitoring equipment on the bypass stack
for the rare occasion that a bypass occurs. The commenter (122) asked whether SSIs are required
to do performance testing on bypass stacks. The commenter (122) stated that a bypass stack is
intended to be a protective system designed for emergency situations that could otherwise
jeopardize the incinerator or the pollution control equipment. The commenter (122) asked
whether operators will be subject to violations and civil action due to bypasses that occur for
emergency reasons. The commenter (122) stated that unless an operator intentionally operates
the SSI with the bypass stack open, the emissions from the bypass stack are not significant to the
overall SSI emissions during the course of an entire year. The commenter (122) stated that in a
multiple hearth incinerator, when a bypass occurs, the sludge charge to the incinerator and the
auxiliary fuel burners can be programmed to shut off, which immediately begins to result in the
extinguishing of the combustion inside the incinerator, which will not commence again until
such time as the system is once again operational.
Response: EPA is not requiring CEMS or performance testing for a bypass stack.
However, you must install, maintain, and operate a device or method for measuring the use of
the bypass stack, including date, time, and duration. The emission limits and standards apply to
emissions from a bypass stack or vent while sewage sludge is in the combustion chamber (i.e.,
until the sewage sludge feed to the combustor has been cut off for a period of time not less than
the sewage sludge incineration residence time). Therefore, use of the bypass stack at any time
that sewage sludge is being charged to the SSI unit is an emissions standards deviation. The use
of the bypass stack during a performance test would invalidate the performance test.
Comment: One commenter (76.1) agreed with EPA proposing that the bypass stack be
monitored for date, time, and length of use. However, this commenter (76.1) as well as another
commenter (97.1, 127.1) disagreed with EPA's view that "use of the bypass stack at any time
that sewage sludge is being charged to the SSI unit is an emissions standards deviation". The
commenters (76.1, 97.1, 127.1) argued that bypass stacks are an essential part of the safety
equipment and operators should be allowed to open the bypass stack immediately as part of a
continuous series of events that includes stopping the sludge feed without triggering a deviation.
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The commenter (76.1) stated that the use of the bypass stack is not normal operations; any event
that would cause use of the bypass stack would likely require sludge feed shut-down, but not
instantaneously. The commenter (76.1) stated that the bypass stack is used if there is equipment
breakdown which would result in filling the building with smoke and/or over pressure situation
in the waste heat recovery boiler; this is an engineered safety component of SSI. The commenter
(76.1) stated that bypass use could be caused by a plugged scrubber or loss of draft because the
fan faults (variable speed drive fails or a power outage). The commenter (76.1) suggested that
EPA revise this language for use during breakdown, 30 minutes at any one time, and not more
than 120 minutes in any calendar year as this is more reasonable operationally than never
allowing use of the designed safety device. The other commenter (97.1, 127.1) stated EPA does
not have the authority to presume deviations of emission standards, particularly when the
bypassed emission controls may not be necessary to meet the emission standard. The commenter
(97.1, 127.1) stated that contemporaneous Part 503 data can show that the sludge content of
cadmium, lead or mercury are so low that it could be met without operating a control device; use
of a bypass stack must not be deemed a deviation of emission limitations for these compounds in
the face of this credible contrary evidence. The commenter (97.1, 127.1) stated that assuming
that the use of a bypass stack results in emission violations for all pollutants is arbitrary and
recommended that subsection (d) of 40 CFR § 60.4900 be removed from the final rule.
Response: The malfunction provisions in the final rule enable the source to document an
affirmative defense to deviations caused by a malfunction, including those events that require use
of the bypass stack to address a process upset. It could also be used to show that emissions were
below the standard at the time of release through the bypass stack.
Comment: One commenter (76.1) argued that the term "Continuous Monitoring
Systems" (CMS) is not a normal part of air compliance vocabulary. The commenter (76.1) stated
that in practice, there are two types of monitoring systems: the first is the traditional Continuous
Emission Monitoring System (CEMS) where there is a direct measurement of the pollutants of
concern such as NOX, 862, and CO; the second type of monitoring system is called Parametric
Monitoring (PM) and is where there is an indirect measure (temperature, flow, or pressure) for
the pollutant of concern. The commenter (76.1) requested that EPA stop the use of Continuous
Monitoring System (CMS) language and only use CEMS or PM.
Response: This term is defined in the General Provisions of parts 60 and 63.
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Comment: One commenter (76.1) requested that EPA revise the definition of "out-of-
control-period" for a CEMS or PM to be inoperative for at least 24 continuous hours. The
commenter (76.1) stated that for a continuous emissions monitor that fails a calibration check,
the "out-of-control period" begins the hour the zero or span check fail and ends the hour after
completion of corrective action; this will look like a two hour violation even if an immediate
repeat shows a good calibration. The commenter (76.1) asserted that this definition for "out-of-
control-period" for CEMS and PM will generate significant amounts of unnecessary paper work.
The commenter (76.1) stated that their current Title V permit allows CEMS and PM "out-of-
control period" for up to 24 continuous hours before any notification to the local air district. The
commenter (76.1) stated that if a CEMS or PM is inoperative, they have other monitors to show
consistent and compliant operation during the time the CEMS or PM is inoperative.
Response: If the source provides data to show that they are in compliance, this will not
be a problem. The General Provisions of Part 63 provide a definition of "out of control". The
Part 63 approach for "out of control" was used for SSIs because it is not addressed in Part 60.
This approach is consistent with EPA's most current approach on monitoring.
Comment: EPA requested comments on mandatory CO monitoring for SSIs. One
commenter (76.1) objected to the requirement of a CO CEMS for existing MHFs. The
commenter (76.1) argued that they already monitor for THC as required by 40 CFR 503 and
noted that USEPA has already allowed the use of THC as a suitable substitute for CO.
Another commenter (76.1) supported the concept that easily measured parameters can be
effective surrogates for direct measurements. The commenter (76.1) provided an example where
EPA states the CO serves as an effective surrogate of 7-PAH and PCB. The commenter (76.1)
stated that they do not support requirements for CO CEMS, but that they agree with EPA ruling
40 CFR 503 that THC is a suitable substitute for CO.
Response: We are not requiring CO monitoring for existing units. For existing SSI units,
use of Cd, CO, HC1, NOX, PM, Pb or SO2 CEMS; ISTMMS; and ISTDMS (continuous sampling
with periodic sample analysis) are approved options, to be used as an alternatives to parametric
monitoring and annual compliance testing. For new SSI units, we are only requiring CO CEMS,
and use of Cd, HC1, NOx, PM, Pb or SO2 CEMS; ISTMMS; and ISTDMS (continuous
sampling, with periodic sample analysis) are approved alternatives to parametric monitoring and
annual compliance testing. Additionally, we are not incorporating the alternative THC
compliance requirement in the final rule. Section 129 requires that limits be set for each of the 9
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regulated pollutants. Surrogates, such as THC, cannot be used in place of the regulated
pollutants. Additionally, the proposed CO emission guidelines limit of 7.4 ppm for existing
fluidized bed SSI units has changed in the final guidelines to 27 ppm, as discussed in Section IV
of the preamble to the final rule.
Comment: _One commenter (54.1, 60.1) suggested that alternate continuous
measurement methods also be required for toxic components of PM such as multi-metal CEMS.
The commenter (54.1, 60.1) provided numerous reasons why they support multi-metals CEMS
including:
EPA acknowledges that metals content in the sludge can be highly variable.
Unless the sludge metals concentrations are continuously measured, metal
emission rates cannot be controlled by restricting sludge incineration rates or
monitoring other operational parameters. However, continuous metals monitoring
of emissions with multi-metals CEMS would adequately characterize metals
emissions despite variability in the sewage feed stock.
• Court required inclusion of emissions during SSM events further emphasizes the
inadequacy of infrequent metals measurements during annual performance
testing. Deviation reports will not include readily accessible hazardous metals
emission data that could be attained with metals CEMS
Commercial, multi-metals CEMS are well-established and have been operating on
stacks for over 6 years. Multi-metals CEMS have all of the supporting
performance specifications, on-going quality assurance procedures, certification
and audit materials. Additionally the CES multi-metals CEMS was awarded EPA
Clean Air Excellence Award, listed on EPA's Other Test Methods web site, etc.
• Although there is limited information concerning metal emissions to set
standards, this situation will not improve until multi-metal CEMS are required.
Response: We recognize that an integrating multiple metals CEMS operates in a manner
fundamentally different than the instrumental metals CEMS for which draft Performance
Specification 10 was developed. Since EPA does not have a published performance specification
for metals CEMS, instrumental or integrating, the source owner must prepare a site-specific
monitoring plan in order to apply a multi-metals CEMS option. The monitoring plan need not
imitate existing CEMS performance specifications (e.g., sampling frequency) but should be
structured to address those characteristic operations of the CEMS reflecting the operating
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principle and associated QA/QC procedures. At this time, without a promulgated performance
specification for this type of CEMS, EPA has determined not to require its use in this rule.
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13.0 RECORDKEEPING AND REPORTING REQUIREMENTS
Comment: One commenter (52.1) stated that because hazardous waste combustion units
are very heavily regulated from both the CAA and RCRA programs, no separate notification
should be required for HWC MACT units. The commenter stated that a notice that a hazardous
waste combustor processes sewage sludge is redundant with existing EPA requirements, and that
no additional oversight of these units is authorized under CAA section 129.
Response: No notification is required in the final rule. The final standards and guidelines
do not apply to sewage sludge that is not burned in an SSI located at a wastewater treatment
facility designed to treat domestic sewage sludge. Sewage sludge that is not burned in an SSI
located at a wastewater treatment facility designed to treat domestic sewage sludge is subject to
other section 129 standards, such as the CISWI standards (40 CFR part 60, subparts CCCC and
DDDD of this part), the OSWI standards (40 CFR part 60, subparts EEEE and FFFF), the MWC
standards (40 CFR part 60, subparts Ea, Eb, Cb, AAAA, and BBBB of this part) or the
Hazardous Waste Combustor rule (40 CFR part 63 subpart EEE).
Comment: One commenter (76.1) stated that for annual reporting, EPA wants the highest
and lowest 3-hour averages for each pollutant and operating parameter; however, earlier in the
rule, EPA said compliance will be based on 4-hour rolling averages. The commenter (76.1)
stated that EPA should revise this requirement to be highest and lowest 4-hour rolling average.
Response: The final rule requires the highest and lowest average parameter value
recorded. This information is not for a direct check against the averaging period, but to see the
range of parameter operation during the reporting period.
Comment: One commenter (95.1) requested EPA allow 90 days to submit performance
test reports in lieu of the 60 days proposed in §§60.4915(c) and 60.5235(c). The commenter
(95.1) also requested that a provision be added for requesting additional reporting time. The
commenter (95.1) argued that it will be difficult to get certain results back and reviewed within
that time frame and close to impossible for dioxin samples without paying a premium. The
commenter (95.1) stated that EPA's current methods have the following hold times for Method
23: 21 days to extraction and 40 days from extraction to analysis; and argued that recently, many
laboratories have struggled to meet these holding times simply because of the large number of
samples to be analyzed. The commenter (95.1) stated that adding the test results from all the
units in this rule will further strain the system and may cause even longer delays.
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Response: EPA thanks the commenters for their feedback. However, EPA maintains the
time allowed for submitting performance tests is appropriate and been used in regulations for
other source categories.
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14.0 OPERATOR TRAINING AND QUALIFICATION REQUIREMENTS
Comment: One commenter (62.1) stated that they do not have an operator training
program at this time. Another commenter (129.1) stated that their incinerator operators are Third
Class State of Ohio Stationary Engineers. The commenter (129.1) stated that they feel this
certification should suffice in lieu of annual training or testing. The commenter (129.1) also
suggested that additional training and/or testing is only required if changes are made to the SSI
system or in plant operating procedures or policies.
Other commenters (76.1) stated that annual updating of training material is an
unreasonable requirement, unless there is a significant change to the SSI. The commenters (76.1)
state that the training course content is to be determined by the State, since it is not detailed in
the regulation. The commenter (76.1) claims that few states have the resources and the
knowledge to create and implement an SSI operator training program; the commenter asserts that
states should implement an SSI operator training program developed by EPA through the
existing wastewater operator certification program. The commenters (76.1) questioned the need
for a separate training and qualification program for SSIs given the rigorous operator
certification programs already in place at the State level, including current State certification
programs for wastewater treatment plants. The commenters (76.1) stated that adding an
additional separate training and qualification program outside of the regulated operator training
each state has in place is not cost effective. The same commenter (76.1) stated that California
already has a certification program for wastewater treatment plant operators, but is unlikely to
develop a separate SSI operator training program. The commenter (76.1) stated that there are
only two agencies in the state which practice incineration and the state is in an economic crisis.
The commenter (76.1) requested that the EPA model operator training program be designed for
easy integration into the existing Wastewater Operator Certification program currently in place at
each State.
Response: EPA does not agree that this is too burdensome. The final rule requires that
qualified operators or supervisors complete an annual review or refresher course, and that they
maintain plant-specific information, including training received through State/local programs,
which is updated on an annual basis. EPA is of the opinion that States/programs can incorporate
the required training into their existing training programs.
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Comment: Some commenters (87.1, 112.1) supported the flexibility in the proposed rule
that allows for the trained and qualified operator to operate the SSI or be the direct supervisor of
one or more plant personnel who may operate the unit. The commenters (87.1, 112.1) also
supported the proposed rule language that allows other knowledgeable plant personnel to operate
the SSI when the qualified operator is not accessible for more than 8 hours, but requested that the
time of allowable SSI operation be increased from 2 weeks to 4 weeks and that, so long as the
training records of the replacement personnel are complete (showing review of the required
information), that the absence of the qualified operator for a period less than or equal to four
weeks not be deemed a deviation to be reported in the annual report.
Response: EPA thanks the commenters for their feedback. However, EPA disagrees that
the time of allowable SSI operation be increased from 2 weeks to 4 weeks when the qualified
operator is not accessible.
Comment: Some commenters (87.1, 112.1) expressed concern regarding the language in
the proposed rule which provides that the training must be obtained through a State-approved
program or by completing the training requirements outlined in the rule. The commenters (87.1,
112.1) stated that the proposed rule is silent as to whether the examination required in the rule
should be conducted in writing; the commenters stated that the examination requirement of the
proposed rule could envision an oral exam or, in addition, require a thesis. The commenters
(87.1, 112.1) suggested that the proposed rule should direct the state program to develop written
examinations following USEPA guidance that assure uniformity throughout the states, ensure
objectivity, and improve efficiencies in grading and, thus, in certifications.
Response: EPA thanks the commenter for their suggestions. The required training must
be documented that it has been completed. Typically, this documentation is a result of the trainee
completing a written or electronic exam that is turned in and a certificate of proof is received.
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15.0 STARTUP, SHUTDOWN, MALFUNCTION
15.1 Emission Limitations at All Times
Comment: Numerous commenters (65.1, 76.1, 80.1, 101.1, 105.1, 109.1, 137.1, 126.1)
disagreed with EPA's proposed language requiring facilities to meet the proposed sewage sludge
incineration standards "at all times" because it would be difficult to comply with certain
proposed emission limits during startup and shutdown. Many of these commenters (65.1, 80.1,
101.1, 105.1, 137.1, 126.1) are specifically concerned about not being able to meet the proposed
CO concentration limit upon startup of a SSI because when a heat up burner system is fired into
a cold vessel, the flame tip is quenched before the combustion is completed creating a small flow
of CO. One commenter (95.1) contended that EPA is proposing a new source CO standard
without any evidence that it can be achieved during startup, shutdown, or malfunction; and
provided an example of CO data from one hazardous waste combustor that averaged 2.2 ppmv
during normal operations but averaged 48.6 ppmv during startup, 40.5 ppmv during shutdown,
and 815.5 during malfunctions. One commenter (97.1, 127.1) stated that emissions of CO and
PM can be expected to be elevated during startup when oxygen levels are higher due to lower
combustion temperatures, resulting in higher pollutant concentrations when corrected to 7
percent oxygen. The commenter (97.1, 127.1) said that absolute pollutant levels tend to increase
during startup and shutdown due to incomplete combustion that is unavoidable at lower
temperatures; and the influence of unstable combustion may be more pronounced during
shutdowns as the incinerator combusts the remaining sewage sludge for 30 minutes or more. The
commenter (97.1, 127.1) recommended that EPA should account for situations where higher
emissions occur during the time it takes to bring control equipment from startup to steady-state
operations. Many commenters (76.1, 109.1, 134.1, 129.1, 105.1) had similar concerns. One
commenter (76.1) urged EPA to change the regulation and allow 72 hour startup and shutdown
relief from the 129 emission standards because a MH furnaces can take up to 72 hours for startup
and/or shutdown because the refractory requires a gradual cool-down and startup to prevent
cracking. Two commenters (76.1, 109.1) provided examples of the amount of time it takes to
start a cold SSI. Two other commenters (134.1, 129.1) stated that for equipment and personnel
protection, the inventory of material in an SSI must be burned out of the system as effectively as
possible; however, it is unlikely that MACT standards could be met consistently by any SSI
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during an emergency or abnormal shutdown condition. The commenters (134.1, 129.1) said this
is particularly true of MH units, as these have inventories of unburned fuel on the order of 30-60
minutes, whereas FB systems typically only have a minute or two of unburned feed inventory.
Another commenter (105.1) recommended that EPA allow an eight hour
startup/shutdown/malfunction exemption from reporting and compliance requirements for CO,
NOX, and scrubber pressure drop. Another commenter (134.1) urged EPA to consider that at
some point during startup of SSI units the introduction of wastewater solids, which are also fuel,
is helpful to bring the combustion temperatures up to normal operating temperatures. The
commenter (134.1) stated that until operating temperatures are reached, it is doubtful that this
interim condition can meet all proposed MACT standards; and shutdown may be similar.
One commenter (95.1) argued that if EPA persists in applying numerical standards during
periods of startup and shutdown, EPA should allow for an alternate oxygen correction during
such events. The commenter (95.1) stated that during the first part of startup and the last part of
shutdown, the oxygen concentrations will approach ambient concentrations; when it does that,
the equation used to calculate the correction factor will approach infinity (dividing by zero). The
commenter (95.1) stated that the HWC MACT rule allows facilities to set up an alternate
correction factor for these conditions (See 40 CFR 63.1206(c)(2)(iii)).
Response: EPA is not promulgating a separate emission standard for the source category
that applies during periods of startup and shutdown because EPA does not have data to support
setting a separate standard during periods of startup and shutdown. EPA requested information in
the NPRM; however, no data were provided. EPA also sought information on emissions during
startup and shutdown as part of its section 114 request for information, but no source provided
data.
Based on the information available at this time, EPA believes that SSI units will be able
to meet the emission limits during periods of startup. The units for which emission test data were
collected, as part of the Agency's CAA 114 information collected, indicated that they use natural
gas, landfill gas, or distillate oil to start the unit and add waste once the unit has reached
combustion temperatures. As EPA noted at proposal, emissions from burning natural gas, landfill
gas or distillate fuel oil are expected to generally be lower than from burning solid wastes. When
these start-up fuels are used, we anticipate that the SSI will reach operating temperatures rapidly,
and any period where the temperature is below the operating temperature is expected to be
generally short. Emissions during periods of shutdown are also generally lower than emissions
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during normal operations because the materials in the incinerator would be almost fully
combusted before shutdown occurs. EPA received no information during the public comment
period that contradicted this conclusion.
We believe that sources will be able to demonstrate compliance with the final standards
through use of continuous parametric monitoring and annual tests. The averaging period for
operating limits is a 12-hour block average, and the average period for CO CEMS (only for
demonstrating compliance with the CO limit for new sources) is a 24-hour block average. The
averaging times should be sufficient during startup and shutdown operations as well as normal
operations. Furthermore, the approach for establishing MACT floors for SSI units ranked
individual SSI units based on actual performance for each pollutant and subcategory, with an
appropriate accounting of emissions variability. Because emissions variability was accounted for,
EPA believes any minor variability that may potentially occur during startup or shutdown has
been adequately addressed.
We believe that sources will be able to demonstrate compliance with the final standards
through use of continuous parametric monitoring and annual tests. The averaging period for
operating limits is a 12-hour block average, and the average period for CO CEMS (only for
demonstrating compliance with the CO limit for new sources) is a 24-hour block average.
Sources are expected to be able to demonstrate compliance using these averaging times during
startup and shutdown operations as well as normal operations. Again, commenters provided no
data or other information to demonstrate that this would not be the case. Furthermore, the
approach for establishing MACT floors for SSI units ranked individual SSI units based on actual
performance for each pollutant and subcategory, with an appropriate accounting of emissions
variability. Because emissions variability was accounted for, EPA believes any minor variability
that may potentially occur during startup or shutdown has been adequately addressed.
Commenters simply allege without providing any supporting information that EPA's variability
analysis does not adequately account for startup and shutdown periods. Without any specific
information, EPA has no basis to conclude that variability during these periods is actually greater
than accounted for in EPA's analysis.
With respect to malfunctions, as is explained in the preamble, EPA has determined that
CAA section 129 does not require that emissions that occur at such times be factored into
development of CAA section 129 standards. Under section 129, emissions standards for new
units must be no less stringent than the level "achieved" by the best controlled similar unit and
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for existing units generally must be no less stringent than the average emission limitation
"achieved" by the best performing 12 percent of units in the category. There is nothing in
section 129 that directs the Agency to consider malfunctions in determining the level "achieved"
by the best performing sources when setting emission standards. Moreover, while EPA
accounts for variability in setting emissions standards consistent with the section 112 and 129
caselaw, nothing in that caselaw requires the Agency to consider malfunctions as part of that
analysis.
Section 129 uses the concept of "best controlled" and "best performing" unit in defining
the level of stringency that section 129 performance standards must meet. Applying the concept
of "best controlled" or "best performing" to a unit that is malfunctioning presents significant
difficulties, as malfunctions are sudden and unexpected events. Accounting for malfunctions
would be difficult, if not impossible, given the myriad different types of malfunctions that can
occur across all sources in the category and given the difficulties associated with predicting or
accounting for the frequency, degree, and duration of various malfunctions that might occur. As
such, the performance of units that are malfunctioning is not "reasonably" foreseeable. See, e.g..
Sierra Club v EPA. 167 F. 3d 658, 662 (D.C.Cir. 1999) (EPA typically has wide latitude in
determining the extent of data-gathering necessary to solve a problem. We generally defer to an
agency's decision to proceed on the basis of imperfect scientific information, rather than to
"invest the resources to conduct the perfect study."). See also, Weyerhaeuser v Costle, 590 F.2d
1011, 1058 (D.C. Cir. 1978) (" In the nature of things, no general limit, individual permit, or
even any upset provision can anticipate all upset situations. After a certain point, the
transgression of regulatory limits caused by 'uncontrollable acts of third parties,' such as strikes,
sabotage, operator intoxication or insanity, and a variety of other eventualities, must be a matter
for the administrative exercise of case-by-case enforcement discretion, not for specification in
advance by regulation."). In addition, the goal of a best controlled unit or best performing unit is
to operate in such a way as to avoid malfunctions of the unit and accounting for malfunctions
could lead to standards that are significantly less stringent than levels that are achieved by a well-
performing non-malfunctioning unit. EPA's approach to malfunctions is consistent with section
129 and is a reasonable interpretation of the statute.
In the event that a source fails to comply with the applicable CAA section 129 standards
as a result of a malfunction event, EPA would determine an appropriate response based on,
among other things, the good faith efforts of the source to minimize emissions during
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malfunction periods, including preventative and corrective actions, as well as root cause analyses
to ascertain and rectify excess emissions. EPA would also consider whether the source's failure
to comply with the CAA section 129 standard was, in fact, "sudden, infrequent, not reasonably
preventable" and was not instead "caused in part by poor maintenance or careless operation." 40
C.F.R. § 60.2 (definition of malfunction). In addition, as discussed in more detail in the
preamble and elsewhere in this response to comment document, EPA has promulgated an
affirmative defense to civil penalties for exceedances of emission limits that are caused by
malfunctions.
With respect to calculating compliance with the 24-hour average CO emissions limit
(corrected to 7 percent 62), we agree that there is an algebraic anomaly that occurs because of
the format of the standard and we have corrected that by providing that during start-up and shut-
down, the correction to 7 percent C>2 does not apply to the CO concentrations as measured by the
CEMS, and that the CO concentrations measured during such periods will be averaged with the
CO concentrations (corrected to 7 percent ©2) measured during other operating periods to
calculate the 24-hour average.
Comment: Some commenters (65.1, 76.1, 97.1, 127.1, 101.1, 126.1) articulated that EPA
should, at the minimum, define "at all times" as "at all times while feeding sludge".
Response: We maintain that the emission limits must be complied with at all times.
Comment: Some commenters (86.1, 108.1, 95.1) noted that there is no data available for
periods of startup, shutdown, malfunction, or feed rate change. One commenter (91.1) is
concerned that they do not have sufficient information to comment on whether in fact the
emission limitations EPA has proposed for normal operations of SSI units can also be met during
startup and shutdown. Two commenters (134.1, 95.1) are concerned that insufficient testing has
been done to support EPA's assumption that startup and shutdown will meet MACT standards.
Commenters (134.1, 95.1) stated that there appears to be no data on SSI emissions under these
conditions. One commenter (91.1) stated that data from similar types of combustion units (i.e.,
boilers) clearly demonstrate that emissions during startup and shutdown are much different than
during normal operation; and it is reasonable to believe that SSI units would experience similar
conditions during startup and shutdown, since they are enclosed combustion devices like boilers.
At least one commenter (95.1) stated that the floor standards must be capable of being met under
the most adverse circumstances reasonably expected to occur (such as malfunctions) anywhere in
the country, citing National Lime Association v. EPA, 627 F.2d 416, 433 (D.C. Cir. 1980), and
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rejected EPA's determination that the standards are not required to reflect periods of
malfunction.
The commenter (91.1) also argued that EPA cannot conclude that special provisions for
emissions during startup and shutdown are not needed based on mere speculation (referenced
NRDC v. EPA, 859 F.2d 156, 210 (D.C. Cir. 1988)). The commenter (91.1) stated that EPA's
bare assumptions that emissions are expected "to be lower, generally" (asserting that emissions
from burning natural gas, landfill gas, or distillate oil before adding waste to the SSI unit are
expected to generally be lower than from burning solid wastes and that emissions during
shutdowns are also generally lower than emissions during normal operations because the
materials in the incinerator would be almost fully combusted before shutdown occurs) do not
constitute a demonstration that applying the proposed emission limitations during startup and
shutdown reflects the performance of the best-performing SSI units under CAA section 129(a)(2)
or is adequately demonstrated to be achievable through the application of the best system of
emission reduction under CAA section 11 l(a)(l).
Another commenter (134.1) stated that periods of startup, shutdown, and malfunctions
are transition operating modes that, while often pseudo-controlled, are basically unstable
conditions and elevated emissions would be expected under these conditions. The commenter
(134.1) is concerned that not all of the proposed limits can be met during these transient
operations and recommended the transition operating modes be excluded from compliance
enforcement periods. The commenter (134.1) argued that SSI processes are controlled, but not
inherently stable, particularly for MH systems; even FB systems are only somewhat stable
processes, though they are more able to accommodate sudden or rapid changes than MH
systems. The commenter (134.1) asserts that this is one of the reasons that it is necessary to
average three one to two-hour or longer test runs in order to generate a single representative
performance test measurement that can be reasonably used as evidence of system performance
capability under the particular test conditions. The commenter (134.1) stated that to extrapolate
test performance to a level that can be met continuously requires some adjustment to allow for
changing conditions beyond the envelope described by those in effect during the more ideal
steady-state performance test.
Response: EPA is not promulgating a separate emission standard for the source category
that applies during periods of startup and shutdown because EPA does not have data to support
setting a separate standard during periods of startup and shutdown. As part of EPA's information
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collection effort for this rulemaking, EPA requested information regarding startup and shutdown
emissions, but did not receive any relevant data in response, or in response to requests in the
preamble to the proposed rule. The units for which emission test data were collected from use
natural gas, landfill gas, or distillate oil to start the unit and add waste once the unit has reached
combustion temperatures. Emissions from burning natural gas, landfill gas or distillate fuel oil
are expected to generally be lower than from burning solid wastes (i.e., natural gas has lower (or
none) metals, chlorine, etc., than sewage sludge). When these start-up fuels are used, we
anticipate that the SSI will reach operating temperatures rapidly, and any period where the
temperature is below the operating temperature is expected to be generally short. Emissions
during periods of shutdown are also generally lower than emissions during normal operations
because the materials in the incinerator would be almost fully combusted before shutdown
occurs. As explained above, commenters provided no data or information to dispute this
conclusion.
For the reasons described in the above responses, EPA's approach to malfunctions is
consistent with section 129 and is a reasonable interpretation of the statute
Comment: One commenter (54.1, 60.1) argued that annual performance testing will not
characterize HAP emissions related to malfunctions of the SSI processes. The commenter (54.1,
60.1) agreed with EPA's statement that it "recognizes that event equipment that is properly
designed and maintained can fail and that such failure can sometimes cause an exceedence of the
relevant emission standard." The commenter (54.1, 60.1) argued that continuous monitoring is
the only method of characterizing and quantifying HAP emissions at the SSI during normal
operations as well as malfunction events. The commenter (54.1, 60.1) recommended that in order
to comply with the recent U.S. Court of Appeals decision (that MACT performance standards
should be applied at all times), multi-metals CEMS should be required to monitor for required
parameters Cd, Pb, and Hg. The commenter (54.1, 60.1) argued that the proposed rule does not
follow the court's ruling to include malfunction emissions in total emissions. The commenter
(54.1, 60.1) stated that in the case of hazardous metals, malfunction events can dominate total
emissions and without continuous metals emission data from a multi-metal CEMS, it will not be
possible to: (1) evaluate the substantial risks associated with metal emissions; or (2) determine
compliance with standards.
Response: Section 129 of the Clean Air Act requires EPA to set emission standards for 9
pollutants, including PM, Hg, Cd, and Pb, which we have done in this final rule. The rule
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requires periodic performance testing to demonstrate compliance with the emission limits with
contemporaneous collection of process and control device operating conditions to use in
establishing enforceable operating limits sufficient to assure continuous compliance. We believe
that the combination of periodic performance testing and continuous monitoring of site-specific
operating limits tied to the performance testing will provide assurance of compliance. In
addition, for existing SSI units, the rule allows the use of Cd, CO, HC1, NOX, PM, Pb or SO2
CEMS; ISTMMS; and ISTDMS (continuous sampling with periodic sample analysis) as
approved alternatives to the parametric monitoring and annual compliance testing. For new SSI
units, CO CEMS are required for determining continuous compliance, and use of Cd, HC1, NOX,
PM, Pb or SO2 CEMS; ISTMMS; and ISTDMS (continuous sampling, with periodic sample
analysis) are approved alternatives to parametric monitoring and annual compliance testing.
Additionally, at this time, EPA does not have a promulgated performance specification
for multi-metal CEMS and therefore it is not appropriate to use to demonstrate compliance.
15.2 Application of Sierra Club Decision to 111/129
Comment: Some commenters (97.1, 127.1, 91.1) argued that EPA incorrectly claims that
its authority to prescribe unique standards for SSM periods is constrained by Sierra Club v. EPA,
551 F.3d 1019 (D.C. Cir. 2008). These commenters (97.1, 127.1, 91.1) stated that EPA has failed
to account adequately for emissions that occur during SSM periods. One commenter (91.1)
argued that the D.C. Circuit's Sierra Club decision manifestly is not binding on EPA's
establishment of performance standards for SSI units under CAA sections 111 and 129. The
commenter (91.1) contended that the Sierra Club decision interpreted section 112, not section
129 (which incorporates by reference section 111), and pointed out that this interpretation is not
merely a technical distinction. The commenter (91.1) referred to the language that the D.C.
Circuit considered dispositive in interpreting EPA's standards-setting authority under section 112
(the statement in the definition of emission limitation and emission standard that it limits the
quantity, rate, or concentration of emissions of air pollutants on a continuous basis) as having
been in the statute since 1977. The commenter (91.1) pointed out that since 1977, EPA has
exempted emissions during SSM events from compliance with NSPS under CAA section 111
(referenced 40 CFR §60.8(c)). The commenter (91.1) argued that congress enacted the
continuous basis language in section 302(k) knowing that EPA's emissions standards under
section 111 exempted SSM periods, and pointed out that there is nothing in the legislative history
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of the 1977 amendments to the CAA that suggests congress intended to overturn that practice.
The commenter (91.1) referenced 551 F.3d at 1027, citing Kamp v. Hernandez, 752 F.2d 1444,
1452 (9th Cir.1985), and stated that it had nothing to do with limitations applied during SSM nor
with EPA's established practice of exempting excess emissions during SSM events from its
performance standards.
One commenter (91.1) argued that the Sierra Club decision does not prevent EPA from
adopting emission standards for SSM periods that are different from those required during
periods of normal operation. Commenter (91.1, 97.1, 127.1) stated that while it is true that a
blanket exemption from any standard may be inconsistent with the Sierra Club holding, the
opinion does not prohibit EPA from applying different, even non-numerical, standards during
SSM events from those standards that apply during steady-state operations. The commenters
(91.1, 97.1, 127.1) stated that the Sierra Club decision only rejected EPA's assertion that it had
discretion to decide not to impose any emission standard whatsoever during SSM periods
(referenced id. at 1027-28, 1030); and in fact, Sierra Club acknowledged that the definition of
emission standard in §302(k) indicates that any one standard need not apply at all times. The
commenters (97.1, 127.1) stated that the court noted that the Part 63 General Provisions at issue
in Sierra Club were not a design, equipment, work practice, or operational standard under §
112(h) and expressly did not decide whether EPA could promulgate a work practice or
engineering standard under CAA §112(h) (much less under the analogous §11 l(h)) instead of the
exemption EPA sought to defend (See 551 F.3d at 1028).
Response: As explained in the preamble to the proposed rule and in the preamble for
today's final rule and elsewhere in this response to comment document, EPA appropriately took
startup and shutdown periods into account in setting standards. EPA does not claim that the
Sierra Club case constrains its authority to prescribe unique standards for SSM periods or
directly addresses the legality of SSM exemptions for section 129 standards. EPA's view is that
the reasoning of the Sierra Club decision calls into question the legality of source category-
specific SSM exemptions in rules promulgated pursuant to section 129. With respect to
malfunctions, as explained in more detail elsewhere in this response to comment document,
EPA's approach to malfunctions is consistent with section 129 and is a reasonable interpretation
of the statute.
EPA disagrees with commenters' suggestion that the existence of an SSM exemption in
rules implementing section 111 in 1977 when Congress enacted the "continuous basis" language
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in the definition of "emission standard" is evidence that Congress approved of that regulatory
SSM exemption. Commenters fail to cite legislative history or any other evidence supporting
that Congress was aware or approved of that exemption.
EPA disagrees with the comment that it can establish work practice standards in lieu of
deriving limitations on the mass or concentration of pollutants emitted during startup or
shutdown under section 129. The commenter who suggested this approach cited CAA Section
112(h) and 11 l(h) as the basis of authority for establishing work practice standards, but Section
129 requires numeric emission standards for the pollutants specified in Section 129(a)(4). See
74 Fed. Reg. 51,395 (Oct. 6, 2009). In any event, EPA's approach to malfunctions is the same
irrespective of the form of the standard at issue. See above responses addressing EPA's
approach to malfunctions.
EPA also disagrees with the commenter that contends that the Sierra Club decision
addresses in any way EPA's current approach to malfunctions. Consistent with Sierra Club, we
have issued standards that apply at all times, including during malfunctions.
15.3 Different/Alternate Standards for SSM
Comment: One commenter (91.1) recommended EPA revise the proposed standards to
account better for SSM events, rather than rely on an affirmative defense to make up for its
failure to do so. One commenter (97.1, 127.1) stated that the reality of the technological
challenges, and the enormous potential cost that would be necessary to monitor SSIs during
SSM, give EPA the basis to prescribe alternative design, equipment, work practice or operational
standards for SSM. The commenter (97.1, 127.1) asked EPA to reconsider its SSM approach and
to allow for alternative work practice standards for SSM events in the form of a facility-specific
SSM plan. The commenter (97.1, 127.1) recommended EPA consider a flexible compliance
option that allows the source to elect to comply with the MACT floor emission standards for
normal operating conditions or with the requirements of the SSM plan for the SSM event.
Another commenter (95.1) argued that in the absence of data and in the absence of a credible
methodology to develop data (even if one can be developed which is not certain), EPA could use
a work practice under § 11 l(h) to address this situation where a methodology to develop a
standard of performance is not feasible due to technological constraints.
One commenter (91.1) recommended that EPA conduct stack testing during startup and
shutdown events, but also acknowledged that emissions testing during startup and shutdown will
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not be an option in all cases. The commenter (91.1) stated that if the Proposed Regulations are
adopted, EPA should be able to use continuous monitoring data to set alternative emission
standards that apply during startup and shutdown, or conclude that sources with the identified
control technology will be able to meet emission limitations established for normal operations
during startup and shutdown periods, as well. The commenter (91.1) suggested that continuous
monitoring data during some SSM events should be possible for the next review of SSI emission
standards, from those facilities that opt to use the continuous emission monitor option in the
Proposed Rule, since the Proposed Rule would require such facilities to operate and report data
from continuous monitors even during SSM events other than during monitor malfunction or
downtime. The commenter (91.1) also suggested that EPA could study facilities'operational logs
to determine an averaging time for an emission standard sufficiently long that typical startups
and shutdowns would not cause an exceedance of the standard. The commenter (91.1) further
suggested that EPA might determine, based on infeasibility of collecting representative data
during startup and shutdown events, that it is necessary and appropriate to promulgate a design,
equipment, work practice, or operational standard, pursuant to CAA section 11 l(h) and/or
section 302(k), in lieu of deriving limitations on the mass or concentration of pollutants emitted
during startup or shutdown. The commenter (91.1) also provided several options that EPA could
use for setting performance standards under CAA sections 111 and 129 that would apply during
malfunction events.
Response: We thank the commenters for their suggestion on further data gathering. As
explained above, EPA collected emissions test data from SSIs owned by nine entities for
purposes of this rulemaking. We also requested any additional emissions data in the preamble to
the proposed rule. However, we did not receive any data during startup and shutdown in
response to that request. For the reasons explained above, EPA is not promulgating a separate
emission standard for the source category that applies during periods of startup and shutdown.
With respect to commenters' suggestion concerning work practice standards, Section
129 requires numeric emissions standards for the pollutants specified in Section 129(a)(4).
Therefore, EPA does not have the authority to establish work practice standards for sources
regulated under section 129. With respect to malfunctions, as explained in more detail
elsewhere in this response to comment document, EPA's approach to malfunctions is consistent
with section 129 and is a reasonable interpretation of the statute.
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Comment: One commenter (91.1) provided examples where courts have recognized that
a technology based standard discards its fundamental premise when it ignores the limits inherent
in technology (NRDC v. EPA, 859 F.2d 156, 208 (D.C. Cir. 1988)). The commenter (91.1) stated
that the D.C. Circuit recognized, in Portland Cement Ass'n v. Ruckelshaus, 486 F.2d 375, 398
(D.C. Cir. 1973), a decision reviewing standards under CAA section 111, that startup and upset
conditions due to plant or emission device malfunction, is an inescapable aspect of industrial life
and that allowance must be made for such factors in the standards that are promulgated (Id. at
399). Similarly, the commenter (91.1) mentioned Essex Chem. Corp. v. Ruckelshaus, 486 F.2d
427, 432 (D.C. Cir. 1973), cert, denied, 416 U.S. 969 (1974), another section 111 case, the court
held that SSM provisions are necessary to preserve the reasonableness of the standards as a
whole (Id. at 433). The commenter (91.1) also mentioned National Lime Ass'n v. EPA, 627 F.2d
416 (D.C. Cir. 1980), another case reviewing emission standards promulgated under CAA
section 111, the court held CAA technology-based standards must be capable of being met under
most adverse circumstances which can reasonably be expected to recur, such as during periods of
SSM(627F.2dat431n.46).
Response: There is nothing in the plain language of the statute or in caselaw addressing
section 129 that directs the Agency to consider malfunctions in determining the level "achieved"
by the best performing sources for purposes of setting standards under section 129. As
explained in the preamble and elsewhere in this response to comment document, EPA's
approach to malfunctions is a reasonable interpretation of the requirements of section 129. The
relevance of Portland Cement and Essex Chem Corp. is questionable in light of subsequent
caselaw and the 1977 amendments to the Clean Air Act's definition of "emission standard"
requiring that such standards be continuous. Further, the NRDC case interprets provisions of the
Clean Water Act that are different in nature than provisions governing standards under section
129 of the Clean Air Act.
In any event, even if those cases are relevant, EPA's overall approach to malfunction
events in this rule, including the promulgation of an affirmative defense, is consistent with the
approach set forth in EPA's 1972 proposed rules cited favorably in Portland Cement and Essex
Chemical in that both EPA's approach today and in 1972 "impart a construction of
"reasonableness" to the standards as a whole and adopts a more flexible system of regulation
than can be had by a system devoid of "give." Portland Cement at 399. Portland Cement and
Essex criticized EPA regulations that contained no specific provisions to address malfunctions
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and EPA's assertion that malfunctions would be dealt with by the informal exercise of discretion
in the Agency's enforcement activities. Those decisions did not require exemptions or less
stringent standards for malfunction events as the commenter suggests. EPA's approach to
malfunctions goes further than reliance on the informal exercise of enforcement discretion in that
it includes regulatory provisions establishing an affirmative defense to civil penalties for
exceedances of emission limits that are caused by malfunctions.
As noted above, the NRDC v EPA. 859 F. 2d 156, 207(D.C. Cir. 1988) case cited by the
commenter is not on point and the discussion of technology-based standards is dicta.
Nevertheless, EPA's approach to malfunctions is consistent with NRDC. NRDC does not
require exemptions or less stringent standards for malfunctions either. Further, the regulatory
affirmative defense included in today's final rule is consistent with the case cited in the NRDC
decision: Marathon Oil Co. v. EPA. 564 F.2d 1253. 1272 (9th Cir. 1977). The court in
Marathon Oil held that EPA must formalize its approach to upsets under the Clean Water Act.
The affirmative defense does so. But see, Weyerhaeuser v Costle, 590 F.2d 1011, 1057-58
(D.C. Cir. 1978) (holding that an informal approach is adequate).
15.4 MACT Floor Analysis as it Applies to SSM
Comment: One commenter (97.1, 127.1) asserted that EPA's "determination" that
malfunctions are not distinct operating conditions is simply an unjustified decision to ignore the
impact that the inherent limitations of combustion and pollution control technologies have on the
ability of SSIs to achieve the proposed standards. The commenter (97.1, 127.1) stated that EPA
declines to use emissions during malfunction periods in its MACT floor analysis for normal
operating conditions and fails entirely to address its authority under §11 l(h) to set alternative
work practice and engineering standards. The commenter (97.1, 127.1) argued that EPA's only
explanation for this decision (the suggestion that applying the MACT floor concept of "best
performing" to a source experiencing a malfunction "presents significant difficulties" (see 75
Fed. Reg. at 63283)) has no basis in the CAA, which requires EPA to distinguish among types
and classes of sources in order to set achievable emission standards and which allows EPA to use
a variety of alternative work practice standards when setting an emission standard is too difficult.
Commenters (91.1, 97.1, 127.1) stated that EPA's argument leads it to ignore the fact that there
are work practices employed by the best performing SSIs that represent the best practices for
minimizing emissions during a malfunction. The commenter (97.1, 127.1) stated that these
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practices may include monitoring combustion parameters to identify a malfunction and stopping
the charging of materials to an incinerator. Commenters (91.1, 97.1, 127.1) stated that while the
measures that represent these best practices will depend on facility-specific issues, such as
incinerator design, pollution control train, and other factors, they are nonetheless the best
technological system of continuous emission reduction, adequately demonstrated. The
commenters (91.1) disputed that EPA cannot hide behind the Sierra Club decision as a
justification for ignoring the inability of even the best performers to achieve the proposed
emission standards during SSM events. The commenter (91.1) pointed out that the CAA section
129 (a)(2), which incorporates the same MACT requirements for solid waste incinerators as
CAA section 112(d) applies to sources of hazardous air pollutants, mandates that the emission
standards be achievable. The commenter (91.1) argued that an emission limitation that applies
during SSM events has not been demonstrated to be achieved by the best-performing 12% of
units in the category unless EPA can show that those best performers actually meet that emission
limitation during SSM events. Moreover, the commenter (91.1) stated that if EPA sets the
emission standards based on the best performing 12% of units in the category (the MACT floor),
those limitations must on average be achieved by the best performers. The commenter (91.1)
stated that although one goal of best performing sources is to operate in such a way as to avoid
malfunctions of their units, there is no basis for EPA's conclusion that malfunction events are not
representative of best-performing sources. The commenter (91.1) stated that many types of
sources are required by many state agencies to submit deviation reports or malfunction reports
when they experience a malfunction that causes an exceedance of an applicable limitation;
however, EPA does not appear to have made any attempt to obtain and analyze such reports, in
order to assess what type of requirement might reasonably apply to SSI units during
malfunctions. The commenter (91.1) also pointed out that the CAA section 11 l(a)(l) requires
that any emission limitation be achievable through the application of emission reduction
technology that the Administrator determines has been adequately demonstrated and therefore
EPA must demonstrate that a numerical limitation, if it is to apply even during SSM events, is in
fact achievable with available technology during such events.
Response: For the reasons explained above, EPA is not promulgating a separate emission
standard for the source category that applies during periods of startup and shutdown. With
respect to the commenter's suggestion to establish work practice standards for malfunctions,
Section 129 requires numeric emissions standards for the pollutants specified in Section
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129(a)(4). In any event, EPA's approach to malfunctions is the same irrespective of the form of
the standard at issue. As explained in the preamble to the proposed rule and elsewhere in this
response to comment document, nothing in section 129 requires that EPA anticipate and account
for the innumerable types of potential malfunction events in setting emissions standards. There is
nothing in section 129 that directs the Agency to consider malfunctions in determining the level
"achieved" by the best performing sources when setting emission standards. Moreover, while
EPA accounts for variability in setting emissions standards consistent with the section 112 and
129 caselaw, nothing in that caselaw requires the Agency to consider malfunctions as part of that
analysis.
Section 129 uses the concept of "best controlled" and "best performing" unit in defining
the level of stringency that section 129 performance standards must meet. Applying the concept
of "best controlled" or "best performing" to a unit that is malfunctioning presents significant
difficulties, as malfunctions are sudden and unexpected events. Accounting for malfunctions
would be difficult, if not impossible, given the myriad different types of malfunctions that can
occur across all sources in the category and given the difficulties associated with predicting or
accounting for the frequency, degree, and duration of various malfunctions that might occur. As
such, the performance of units that are malfunctioning is not "reasonably" foreseeable. See, e.g.,
Sierra Club v EPA. 167 F. 3d 658, 662 (D.C.Cir. 1999) (EPA typically has wide latitude in
determining the extent of data-gathering necessary to solve a problem. We generally defer to an
agency's decision to proceed on the basis of imperfect scientific information, rather than to
"invest the resources to conduct the perfect study."). See also, Weyerhaeuser v Costle, 590 F.2d
1011, 1058 (D.C. Cir. 1978) (" In the nature of things, no general limit, individual permit, or
even any upset provision can anticipate all upset situations. After a certain point, the
transgression of regulatory limits caused by 'uncontrollable acts of third parties,' such as strikes,
sabotage, operator intoxication or insanity, and a variety of other eventualities, must be a matter
for the administrative exercise of case-by-case enforcement discretion, not for specification in
advance by regulation."). In addition, the goal of a best controlled unit or best performing unit is
to operate in such a way as to avoid malfunctions of the unit and accounting for malfunctions
could lead to standards that are significantly less stringent than levels that are achieved by a well-
performing non-malfunctioning unit. EPA's approach to malfunctions is consistent with section
129 and is a reasonable interpretation of the statute.
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Indeed, commenters' observation that the "measures that represent these best practices
will depend on facility-specific issues" supports EPA's view that it would be impracticable to
establish emissions standards for an entire source category or subcategory that takes
Comment: One commenter (91.1) argued, by virtue of the variability analysis itself, the
Proposed Standards are representative of emissions achieved during normal (very stable)
operations and are not representative of emissions during SSM events (which can be highly
variable). The commenter (91.1) stated that the variability EPA used in setting the Proposed
Standard reflects at most only the normal variation in emissions experienced during normal
operations because the analysis was performed on emissions data from performance tests, when
the source is being operated at normal levels and when efforts are being made to maintain
steady-state conditions. The commenter (91.1) purported that since performance test data are not
collected during SSM events, the variability factors EPA derived to establish the Proposed
Standards could not possibly incorporate emissions variability experienced during SSM events.
One commenter (95.1) specifically noted that EPA's own National Stack Testing Guidance
precludes and possibly prohibits the development of emission-based standards that apply during
periods of startup, shutdown, or malfunction ("Operations during periods of startup, shutdown,
and malfunction do not constitute representative conditions for the purposes of a performance
test." Section VII. 5 of the September 30, 2005 Final Clean Air Act National Stack Testing
Guidance). The commenter (95.1) stated that even if a facility had such data, EPA would not
have accepted it in a test report according to this guidance, much less have incorporated it into an
emissions database based on compliance test reports.
Commenter (91.1) and another commenter (97.1, 127.1) stated that for these same
reasons, EPA's attempt to consider variability in setting emission standards does not eliminate
the need for different standards that apply during malfunctions. The commenter (95.1) argued
similar points regarding variability. The commenter (95.1) stated that if EPA decides to require
facilities to meet the same emission standards under both normal operations and during
malfunctions, EPA must use data from both normal operations and malfunctions in developing
those standards.
Response: As explained above, EPA is not promulgating a separate emission standard for
the source category that applies during periods of startup and shutdown and expects that sources
will be able to meet the emission limits during such periods. Moreover, EPA requested data
regarding emissions during startup and shutdown, and commenters failed to provide any
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additional data during the comment period. For the reasons explained above, EPA has
adequately accounted for startup and shutdown periods in the final emissions standards, based on
the available information.
Periods of startup, normal operations, and shutdown are predictable and routine aspects
of a source's operations. However, by contrast, malfunction is defined as a "sudden, infrequent,
and not reasonably preventable failure of air pollution control and monitoring equipment,
process equipment or a process to operate in a normal or usual manner * * * "(40 CFR 60.2).
EPA has determined that malfunctions should not be viewed as a distinct operating mode and,
therefore, any emissions that occur at such times do not need to be factored into development of
CAA section 129 standards, which, once promulgated, apply at all times. Nothing in CAA
section 129 or in case law requires that EPA anticipate and account for the innumerable types of
potential malfunction events in setting emission standards.
For the reasons described in the above responses, EPA's approach to malfunctions is
consistent with section 129 and is a reasonable interpretation of the statute.
Nothing in the National Stack Testing Guidelines cited by commenter addresses whether
standards can apply during periods of startup and shutdown or periods of malfunction. We have
explained elsewhere in this response to comment document the basis for our startup and
shutdown standards and the basis for our approach to malfunctions. We have also explained
elsewhere in this response to comment document how compliance can be determined during
such periods.
Comment: One commenter (91.1) asserted that EPA is going beyond the MACT floor
without making the demonstrations that the statute and case law require EPA to make in order to
impose beyond-the-floor MACT standards. The commenter (91.1) stated that this is especially
obvious when one considers the multitude of conditions EPA proposes to impose on sources
during malfunctions, in order to be excused from civil penalties: EPA makes no attempt to justify
those conditions as reasonable, taking into consideration the cost of achieving such emission
reduction, and any non-air quality health and environmental impacts and energy requirements
(referenced CAA section 129(a)(2)).
Response: EPA is not setting a beyond-the-floor standard. For the reasons described in
the above responses, EPA's approach to malfunctions is consistent with section 129 and is a
reasonable interpretation of the statute.
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15.5 Format of Affirmative Defense
Comment: The commenter (91.1) disagreed with EPA's affirmative defense option and
argued that inclusion of the affirmative defense does not cure EPA's failure to set emission
standards that are achievable during SSM events. The commenter (91.1) urged EPA to
promulgate an emission standard that eliminates the situation where SSI units sometimes will be
unable to comply with the Proposed Standards because of malfunctions, even if their equipment
is properly designed and maintained, through no fault of the source. The commenter (91.1)
recommended that SSI units be subject to differentiated requirements, achievable with the
identified best technology, during SSM events. The commenter (91.1) argued that the proposed
affirmative defense shifts the burden to the source to prove that a myriad number of criteria are
met and actions were taken by the source (which bear no direct relation to the statutory factors
for performance standards under CAA sections 111 and 129), in order to avoid civil penalties.
Response: With respect to malfunctions, as explained in the proposed and final rules and
in more detail elsewhere in this response to comment document, EPA has determined that CAA
section 129 does not require that emissions that occur at such times be factored into development
of CAA section 129 standards and that it is reasonable not to do so.
The affirmative defense does not change the burden of proof with respect to establishing
a violation. The burden of proof remains with the plaintiff in an enforcement action. See, e.g.,
40 C.F.R. 22.24. If a violation has been established and a source wishes to assert the affirmative
defense, the source does bear the burden of establishing that the elements of the affirmative
defense have been met. This burden-shifting is appropriate because the source is in a better
position to determine the facts required to establish the defense. See, e.g.., Arizona Pub. Serv. Co.
v. EPA, 562 F.3d 1116, 1120, 1129-30 (10th Cir. 2009) (rejecting industry challenge to EPA's
use of an affirmative defense to address excess emissions during malfunction events.). With
respect to EPA's justification for the affirmative defense criteria, see EPA's responses to
comment below.
Comment: One commenter (91.1) said that EPA needs to substantially revise and
streamline the proposed affirmative defense for it to be of practical value, and argued that many
aspects of the affirmative defense would make it unavailable as a practical matter for many, if
not most malfunctions. The commenter (91.1) stated that many of these limitations on the
affirmative defense also are not directly related to the question of whether an exceedance of the
emission limitations due to a malfunction should be excused. One commenter (91.1) stated that
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several of the conditions for establishing an affirmative defense use phrases that are subject to a
wide range of interpretations, and that on their face do not recognize any need for reasonableness
or cost-effectiveness. The commenter asked how will the enforcement authority, or a judge,
determine whether "proper design" or "better operation and maintenance practices" could have
prevented a malfunction (section 60.4861(a)(l)(ii)), whether a recurring malfunction is a result
of "inadequate design" (section 60.4861(a)(l)(iv)), whether repairs were made "as expeditiously
as possible" (section 60.4861(a)(2)), whether the source took "all possible steps" to minimize the
impact of the excess emissions (section 60.4861(a)(5)), and whether emissions control systems
"were kept in operation if at all possible" (section 60.4861(a)(6)). Two other commenters (97.1,
127.1, 95.1) had similar concerns. The commenter (85.1) recommended that EPA drop the
reference to "any" activity in 60.4861(a)(l)(iii). The commenter (85.1) is concerned that there
are several references to "All" that would make it difficult to ever satisfy the affirmative defense
(or rebuttable presumption). The commenters (91.1, 97.1, 127.1, 95.1) argued that at a
minimum, the vague and unqualified descriptors in the criteria for demonstrating the affirmative
defense will inevitably lead to varying conclusions as to whether a violation has occurred,
resulting in inconsistency from one jurisdiction to the next. The commenter (95.1) suggested
several modifications to the regulatory language.
Response: EPA does not agree that the affirmative defense criteria are overly vague and
will result in varying interpretations. Courts are well equipped and often do evaluate and apply
criteria that are subject to differing interpretations. Many of the conditions were modeled after
the conditions of the affirmative defense in EPA's SIP SSM policy, which several states have
adopted into their SIPs.
We do not have any indication that parties to enforcement proceedings have had any
significant difficulties applying the terms of these SIP affirmative defenses. (See, e.g.. State
Implementation Plans: Policy Regarding Excessive Emissions During Malfunctions, Startup,
and Shutdown (Sept. 20, 1999); Policy on Excess Emissions During Startup, Shutdown,
Maintenance, and Malfunctions (Feb. 15, 1983)). Other conditions are modeled after a Federal
Implementation promulgated by EPA. (40 C.F.R. 50.1312). EPA's view is that use of
consistent terms in establishing affirmative defense regulations and policies across various CAA
programs will promote consistent implementation of those rules and policies. However, EPA
agrees that some of the terms or phrases in the regulatory text establishing the affirmative can be
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revised or streamlined to some extent. Such revisions are discussed elsewhere in this response to
comment document.
Comment: One commenter (91.1) argued that the numerous items listed in the proposed
40 CFR §60.4861(a) and 40 CFR §60.5181(a) for determining whether excess emissions during
a malfunction should be considered a violation should not be listed as mandatory criteria, all of
which have to be met in order for an exceedance to be excused. For example, the commenter
(91.1) stated that the proposed section 60.4861(a)(l)(i) states that the excess emissions must
have been "caused by a sudden, short, infrequent, and unavoidable failure of air pollution control
and monitoring equipment, process equipment, or a process to operate in a normal or usual
manner"; however, there is no practical reason why a sudden, infrequent, and unavoidable
equipment failure should be exempted if it was "short" but considered a violation if it was not
"short". Similarly, the commenter (91.1) asked why a malfunction should be considered a
violation of the standards if it is not "infrequent," even though it is "not part of a recurring
pattern indicative of inadequate design, operation, or maintenance" (see proposed section
60.486 l(a)(l)(iv)).
Response: EPA is revising the affirmative defense language to delete "short" from
60.4861.(a)(l)(i), because other criteria in the affirmative defense require that the source assure
that the duration of the excess emissions "were minimized to the maximum extent practicable."
EPA disagrees with the commenter that suggests that it need not satisfy all of the requirements of
the affirmative defense. As noted above, the requirements set forth in the affirmative defense
provision are modeled after the conditions of the affirmative defense in EPA's SIP SSM policy.
Finally, EPA is not eliminating the word "infrequent" from 40 CFR §60.486l(a)(l)(i), because
that term appears in the definition of malfunction in 60.2.
Comment: Two commenters (97.1, 127.1, 95.1) are concerned with the proposed
requirement to prepare a written root cause analysis. The commenter (97.1, 127.1) stated that the
requirement to prepare a written root cause analysis "to determine, correct, and eliminate the
primary causes of the malfunction" is unreasonably stringent and would result in some categories
of malfunctions potentially never satisfying the proposed affirmative defense. The commenter
(97.1, 127.1) provided an example such that the only method a source has to "correct and
eliminate" a malfunction caused by a power failure from the grid is to install redundant power
generating facilities. The commenter (97.1, 127.1) stated that the technological and economic
impacts of "super engineering" facilities in the way envisioned by EPA are unreasonable and
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disconnected from the authority EPA has to set standards under the CAA. The commenter (95.1)
added that for most malfunctions, the cause is immediately obvious; and there is no need to go
into a detailed root cause analysis to determine the cause. The commenter (95.1) also stated that
it is impossible to eliminate the causes for certain malfunctions (e.g., lightning strikes). The
commenter (95.1) argued that the proposed language assumes that all malfunctions are equally
significant and need an identical degree of investigation. The commenter (95.1) stated that a root
cause analysis should only be-used as a last resort when other reasonable methods fail to show
what caused the malfunction or when the serious nature of an event might make such an analysis
necessary. The commenter (95.1) stated the facility needs to have some discretion in making
that determination. The commenter (95.1) is also concerned that 30 days may not be enough
time to complete a root cause analysis and recommended that EPA allow 90 days to complete the
report. The commenter also recommended that EPA allow notification by e-mail or other
electronic forms to submit the root cause analysis as faxing is an obsolete technology. The
commenter (95.1) suggested several modifications to the regulatory language.
Response: EPA is revising this requirement to clarify that the purpose of the root cause
analysis is to determine, correct, and eliminate the primary cause of the malfunction. The root
cause analysis itself does not necessarily require that the cause be determined, corrected or
eliminated. However, in most cases, EPA believes that a properly conducted root cause analysis
will have such results. EPA does not assume that all malfunctions require an identical degree of
investigation. A root cause analysis need not be more detailed than is called for given the nature
of the malfunction. In addition, as discussed below EPA is revising the 30 day requirement for a
written report to the Administrator.
When a malfunction occurs, sources must report them according to the applicable
reporting requirements of the Subpart. An affirmative defense to civil penalties for exceedances
of emission limits that are caused by malfunctions is available to a source if it can demonstrate
that certain criteria and requirements are satisfied. The criteria ensure that the affirmative
defense is available only where the event that causes an exceedance of the emission limit meets
the definition of malfunction in 40 C.F.R. 63.2 (sudden, infrequent, not reasonably preventable
and not caused by poor maintenance and or careless operation) and where the source took all
appropriate actions to minimize emissions. In addition, the source must meet certain
notification, recordkeeping and reporting requirements. For example, as discussed previously,
the source must prepare a written root cause analysis and submit a written report to the
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Administrator documenting that it has met the conditions and requirements for assertion of the
affirmative defense.
In response to this comment, EPA has provided an administrative adjustment to the ICR
for this standard that shows what the notification, recordkeeping and reporting requirements
associated with the assertion of the affirmative defense might entail. EPA's estimate for the
required notification, reports and records, including the root cause analysis, is based on the time
and effort required of a source to review relevant data, interview plant employees, and document
the events surrounding a malfunction that has caused an exceedance of an emission limit. The
estimate also includes time to produce and retain the records and reports for submission to EPA.
EPA provides this illustrative estimate of this burden because these costs are only incurred if
there has been a violation and a source chooses to take advantage of the affirmative defense.
If a source is in compliance and does not encounter malfunctions that cause a violation of
the standard, EPA does not expect this activity to be routinely performed by a source. The
decision to meet the notification, reporting and recordkeeping requirements rests with the source,
who must weigh the cost of meeting the requirements against their perceived need to prepare an
affirmative defense. These requirements are also similar in nature to the SSM reporting and
recordkeeping requirements that sources were previously subject to and require records and
reports of the type that many sources would already keep in order to demonstrate compliance
with the general duty to minimize emissions.
Comment: One commenter (91.1) stated that the language "if at all possible" in 40 CFR
60.4861(a)(6) is an extreme term that bears no relation to good air pollution control practices,
and argued that this provision, as well as proposed sections 60.4861(a)(l)(ii) and (iv), should be
qualified, as EPA has qualified similar provisions in the NESHAP General Provisions in 40 CFR
§63.6. The commenter (91.1) recommended that these conditions be qualified with caveats that
the operation must be consistent with safety and good air pollution control practices, that it does
not require the source to make further efforts to reduce emissions below what the standards
require, and that it does not require regular operation of backup or standby pollution control
equipment. The commenter (91.1) stated that EPA has long recognized, in the General
Provisions applicable to NSPS, that it is appropriate to require sources to operate the affected
facility and related air pollution control technology "to the extent practicable...consistent with
good air pollution control practice for minimizing emissions" during SSM periods, not "if at all
possible" (See 40 CFR § 60.1 l(d)). The commenter (91.1) contended that EPA cannot abandon
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those rational approaches and adopt the kind of absolute requirements implied by the Proposed
Rule, without an explanation of why it is necessary and appropriate to do so.
Response: As noted above, many of the conditions were modeled after the conditions of
the affirmative defense in EPA's SIP SSM policy, which several states have adopted into their
SIPs. We do not have any indication that parties to enforcement proceedings have had any
significant difficulties applying the terms of these SIP affirmative defenses. (See, e.g.. State
Implementation Plans: Policy Regarding Excessive Emissions During Malfunctions, Startup,
and Shutdown (Sept. 20, 1999); Policy on Excess Emissions During Startup, Shutdown,
Maintenance, and Malfunctions (Feb. 15, 1983)). Other conditions were modeled after a
Federal Implementation promulgated by EPA. ((40 C.F.R. 50.1312). EPA's view is that use of
consistent terms in establishing affirmative defense regulations and policies across various CAA
programs will promote consistent implementation of those rules and policies. However, EPA
agrees that some of the terms or phrases in the regulatory text establishing the affirmative can be
revised or streamlined. For example, as discussed above, EPA is revising the affirmative
defense language to delete "short" from 60.4861.(a)(l)(i) because other criteria in the affirmative
defense require that the duration of the excess emissions "were minimized to the maximum
extent practicable." In addition, EPA is revising 60.4861(a)(6) to add "consistent with good air
pollution control practice for minimizing emissions" as recommended by the commenter. We
are also deleting the term "severe" in the phrase "severe personal injury" in 60.4861(a)(4)
because we do not think it is appropriate to make the affirmative defense available only when
bypass was unavoidable to prevent severe personal injury. EPA disagrees that other terms and
conditions in 60.4861(a)(4) or in the other conditions of the affirmative defense are overly
subjective or extreme or need further qualification. EPA acknowledges that some of the criteria
may overlap to some extent and under some circumstances (e.g., such as 60.4861(a)(6) and (a)(2)
as pointed out by commenters), but does not believe it is necessary to change the requirements.
To the extent there is overlap, the same information can be used to meet the provisions in
question.
Comment: One commenter (91.1) is concerned that the proposed section 60.4861(a)(4)
would preclude a facility from taking advantage of the affirmative defense if the malfunction
involved bypassing control equipment or a process and the bypass was not "unavoidable to
prevent loss of life, severe personal injury, or severe property damage". The commenter (91.1)
is concerned that this language is stated in such extreme terms that it may be difficult or
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impossible to meet this criterion, even though bypassing the control equipment or the process
was an appropriate exercise of good air pollution control practices. For example, the commenter
(91.1) stated that a bypass can be the appropriate response to an upset in order to prevent excess
emissions, e.g., fouling of pollution control equipment media that in turn would result in reduced
pollution control equipment efficiency or increased pollution control equipment downtime. The
commenter (91.1) stated that there can be substantial room for disagreement about what
constitutes "severe" property damage. The commenter (91.1) asked what degree of injury to
employees must the bypass avoid in order to qualify as avoiding "severe" personal injury. The
commenter (91.1) stated that besides the unclear and subjective nature of these criteria, there is
nothing inherent to standards under CAA sections 111 and 129 that require a source to avoid
bypassing control equipment to such a degree. The commenter (91.1) said that it is not apparent
at all why the CAA would disfavor bypassing "a process" in this way.
Response: See above response.
Comment: One commenter (91.1) stated that the language "all possible steps" in
proposed section 60.4861(a)(6), is a subjective term, and presents a disconnect between the
absolute and extreme requirement of the affirmative defense and the provisions of the CAA
designed to attain ambient air quality standards and protect human health and the environment.
The commenter (91.1) said that the CAA does not require sources to take "all possible steps" to
control emissions, even to minimize the impact of hazardous air pollutant emissions on human
health under CAA section 112(f). The commenter (91.1) also stated that it is unclear how this
criterion for qualifying for the affirmative defense differs from proposed section 60.4861(a)(2),
which requires that the frequency, amount, and duration of excess emissions "were minimized to
the maximum extent practicable". The commenter (91.1) contended that unless EPA explains
what additional showing would be needed by section 60.4861(a)(6), it should be eliminated.
Response: See above response.
Comment: One commenter (91.1) is concerned about the requirement proposed in
section 60.4861(a)(8) such that the language that says a source must show that "at all times, the
facility was operated in a manner consistent with good practices for minimizing emissions",
could be read to go way beyond an analysis of why equipment may have malfunctioned and
place an insurmountable burden on the source to meet a "good practices" standard (undefined)
for the whole sewage treatment plant, industrial plant, or commercial premises. The commenter
(91.1) stated that the problem is that EPA has used "facility" in some aspects of the Proposed
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Rule to indicate something much larger than the SSI unit subject to the Proposed Standards (See
proposed 40 CFR §60.4780). The commenter (91.1) contended that this factor could allow a
regulatory enforcement official to potentially measure the entirety of operations at a site against a
multitude of arbitrary "good practices" and subjectively find the source lacking, thereby denying
the source the ability to assert an affirmative defense. The commenter (91.1) recommended that
if EPA retains this condition for the affirmative defense, of demonstrating operation consistent
with good practices for minimizing emissions, EPA must clarify that this condition applies to the
"affected facility" or "existing facility," as those terms are defined in 40 CFR §60.2.
Furthermore, the commenter (91.1) stated that if EPA really does intend for this condition to
apply to operation of the entire site, and not just the SSI unit, then EPA must justify why EPA
has the statutory authority to shift its focus from the SSI unit to the plant as a whole.
Response: We have revised section 60.4861(a)(8) and 60.5181(a)(8) to refer to the
"affected facility," which is defined in section 60.4930 and 60.5250.
Comment: One commenter (91.1) is concerned about the requirement proposed in
section 60.4861(a)(9) such that the language that reads "have prepared a written root cause
analysis to determine, correct, and eliminate the primary causes of the malfunction and the
excess emissions resulting from the malfunction event at issue" does not implement the statutory
criteria for standard-setting under sections 111 and 129. The commenter (91.1) said that if read
literally, it would mean that a source could never take advantage of the affirmative defense if the
source was unable to determine the primary cause of the malfunction or was unable to correct
that cause. The commenter (91.1) asserted that EPA has defined a malfunction as an event that
is "unavoidable" and unforeseeable (see proposed section 60.4861(a)(l)(i)-(iii)); therefore, it
should be expected that in many cases the primary cause of the malfunction will not be
ascertainable, or it will not be possible to identify a way to ensure the malfunction will not recur.
The commenter (91.1) stated that EPA has long acknowledged this reality in the General
Provisions applicable to NSPS, which requires that written reports of excess emissions include
the "nature and cause of any malfunction, if known...." (see 40 CFR §60.7(b)(2)). In addition,
the commenter (91.1) stated that requiring the facility to eliminate the primary causes of the
malfunction, without regard to "taking into consideration the cost of achieving such" elimination
and the "non-air quality health and environmental impacts and energy requirements" associated
with its elimination is unreasonable and entirely inconsistent with the criteria for standards
established under CAA sections 11 l(a)(l) and 129(a)(2).
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Response: EPA is revising this requirement to clarify that the purpose of the root cause
analysis is to determine, correct, and eliminate the primary cause of the malfunction and that the
root cause analysis itself does not necessarily require that the cause be determined, corrected or
eliminated. However, in most cases, EPA believes that a properly conducted root cause analysis
will have such results.
Comment: One commenter (91.1) said the requirement in proposed section 60.4861(b) to
notify the Administrator by telephone or fax as soon as possible, but no later than two business
days after the malfunction begins, and then to submit a written report within 30 days of the initial
occurrence of the malfunction that demonstrates, "with all necessary supporting documentation,"
that the source met all of the multitude of criteria for the affirmative defense, is unreasonable and
unnecessary. The commenter (91.1) stated that it is novel at best for a person to be determined to
have acted unlawfully unless the person has submitted his entire defense before he is even
notified of a potential enforcement action. The commenter (91.1) stated that in many cases, it
would be obvious to the enforcement authority (not "the Administrator"), based on the kind of
short malfunction or deviation report that sources already submit under many air programs, that
an exceedance of the Proposed Standards resulted from an unforeseen and unavoidable
equipment failure or process upset. The commenter (91.1) contended that it is extremely
inefficient and burdensome for both sources and regulators to require a complete justification of
the affirmative defense before the enforcement authority has indicated any need for further
investigation. Additionally, the commenter (91.1) stated that allowing only 30 days to provide
the kind of extensive documentation required by the affirmative defense as currently written,
including a completed root cause analysis, is unreasonable. The commenter (91.1)
recommended ninety days as the minimum time that should be allowed, unless EPA substantially
streamlines the criteria for the affirmative defense.
Response: The requirement to notify the Administrator of an exceedance during a
malfunction is reasonable and consistent with many other upset and malfunction notification
requirements that have been applied without significant difficulty. (See, e.g. 40 CFR
63.6(e)(3)(iv)). EPA is revising 60.4861(b) to state that a written report must be submitted
within 45 days of the initial occurrence of the malfunction. We further revised this provision to
allow the source to seek an extension of up to an additional 30 days.
15.6 Startup and Shutdown in Affirmative Defense
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Comment: One commenter (91.1) stated that EPA's rationale for excluding startup and
shutdown events from the proposed affirmative defense is unclear. The commenter (91.1) argued
that if EPA persists in its proposal not to provide separate emission limitations for startup and
shutdown of the SSI units, and if in fact excess emissions from an SSI unit cannot reasonably be
avoided during a startup or shutdown, not because of failure of a process or equipment but
because of the nature of conditions while starting up or shutting down the source, there is no
apparent reason why EPA would not provide the same kind of affirmative defense that it
proposes to provide for malfunctions.
Response: EPA is promulgating the affirmative defense for malfunctions only, not for
periods of startup and shutdown. As explained earlier in this preamble, EPA believes that
malfunction events should be treated differently than periods of startup and shutdown, which are
predictable and routine aspects of a source's operations. In contrast, EPA does not view
malfunctions as a distinct operating mode. Because startup and shutdown periods are part of a
source's normal operations, the same approach to compliance with, and enforcement of,
applicable emissions standards during those periods should apply as otherwise applies during a
source's operations. Further, as explained above, periods of startup and shutdown - but not
malfunctions - are taken into account when establishing section 129 emissions standards. For
these reasons, EPA does not believe it is appropriate to apply the affirmative defense provision to
startup and shutdown periods.
15.7 Application of Affirmative Defense
Comment: Many commenters (84.1, 119.1, 91.1) argued that EPA's affirmative defense
for violating emission standards during startup, shutdown, and malfunction events is unlawful.
The commenter (AA-8) argued that the affirmative defense that EPA proposes to allow in case of
malfunctions is impermissible and goes directly against congressional intent by attempting to
eliminate, via regulations, civil penalties in cases of malfunction where the violator demonstrates
that nine factors are obtained. The commenter (84.1, 119.1) stated that the affirmative defense
runs counter to two clearly expressed intents of Congress: (1) the burden it places on citizen
groups makes it less likely that citizens will enforce the Act, see, e.g., Delaware Valley Citizens'
Council, 478 U.S. at 560; and (2) several of the factors at issue in the affirmative defense
undercuts Congress's intent that citizen suit enforcement should avoid re-delving into
"technological or other considerations," NRDC v. Train, 510 F.2d at 700. The commenter (84.1,
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119.1) pointed out that EPA's regulation would mean that if Sierra Club sued a cement kiln for
its violation of the NESHAP for mercury, the kiln owner would be exempt from paying civil
penalties so long as the kiln owner satisfied the requirements set forth in EPA's regulations. See
Cement Kilns Rule, 75 Fed. Reg. at 55,053-54 (to be codified at 40 CFR § 63.1344). The
commenter (84.1, 119.1) stated that the affirmative defense would likely be used on a routine
basis by polluters seeking to avoid penalties, just as the malfunction exemption was; and as a
result, citizens who seek civil penalties against polluters in order to better achieve the Act's goals
will be forced to engage in fact-intensive disputes 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. Another commenter
(PC-427, 91.1) stated that the affirmative defense EPA describes in the Proposed Rule are
unreasonable and impracticable, and inappropriately shifts the burden to the source to disprove
alleged violations during malfunctions. Two commenters (91.1, 95.1) argued that the affirmative
defense places the source in the position of proving its innocence, rather than EPA or another
enforcement authority having to prove that the source violated the CAA. The commenter (95.1)
said the burden of proof should be on the Agency not the facility. The commenter (91.1) stated
that being able to assert a defense obviously is not the same as complying with emission
limitations that are properly set in accordance with sections 111 and 129. Two commenters
(91.1, 97.1, 127.1) stated that it is unclear where EPA finds the legal authority in the CAA to
shift the burden to the regulated community of proving (or disproving) essential elements of an
alleged violation. The commenters (91.1, 97.1, 127.1) declared that the statute is silent as to the
issue and the ordinary default rule [is] that plaintiffs bear the risk of failing to prove their claims
citing Shaeffer v. Weast, 546 U.S. 49 (2005), and quoting: McCormick on Evidence §337, at 412
["The burdens of pleading and proof with regard to most facts have and should be assigned to the
plaintiff who generally seeks to change the present state of affairs and who therefore naturally
should be expected to bear the risk of failure or proof or persuasion"]; C. Mueller & L.
Kirkpatrick, Evidence § 3.1, p. 104 (3d ed. 2003) ["Perhaps the broadest and most accepted idea
is that the person who seeks court action should justify the request, which means that the
plaintiffs bear the burdens on the elements in their claims"]. The commenters (91.1, 97.1, 127.1)
stated that while the Supreme Court has recognized exceptions such as affirmative defenses,
courts retain the authority to establish such rules unless Congress acts to delegate that authority;
and argued in this instance, that EPA has not provided any justification for requiring a source to
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prove its innocence; in fact, to fully demonstrate its innocence within 30 days of the event,
without even being charged. The commenter (91.1) argued that if EPA adopts an approach
along the lines of the proposed affirmative defense, it should be stated instead in terms that, once
a source has claimed that its excess emissions were related to a malfunction, it will not be
considered to be in violation of the standards unless the enforcement authority demonstrates that
the source is not entitled to claim the malfunction.
Response: EPA recognizes the competing concerns of the commenters. On the one hand,
citizen enforcers are concerned about additional complications in their enforcement actions
against alleged violators. On the other hand, industrial sources are concerned about being
penalized for violations caused by malfunctions that could not have prevented and were
otherwise appropriately handled (as reflected in the affirmative defense criteria). EPA has
utilized its Section 301(a)(l) authority to issue regulations necessary to carry out the Act in a
manner that appropriately balances these competing concerns. See, e.g., Arizona Pub. Serv. Co.
v. EPA, 562 F.3d 1116, 1120, 1129-30 (10th Cir. 2009) (rejecting industry challenge to EPA's
use of an affirmative defense to address excess emissions during malfunction events.).
EPA disagrees with the commenters who alleged that the affirmative defense provision
for malfunctions is inconsistent with the section 113(e) and sections 304 of the Act. Section 304
gives district courts jurisdiction "to apply appropriate civil penalties." Section 113(e)(l)
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 any penalty to be
assessed. If a court determines that the affirmative defense elements have been established, then
a penalty is not appropriate and penalty assessment pursuant to the section 113(e)(l) factors does
not occur.
EPA also 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.
Further, litigating whether the affirmative defense is or is not available will not burden citizen
groups 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
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to generate the type of fact-intensive disputes that the commenter complains of. In addition,
several of the affirmative defense criteria are exactly the type 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 by a preponderance
of the evidence that, among other things, the excess emissions "were caused by an unavoidable
failure of air pollution control and monitoring equipment, process equipment, 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 foreseen and avoided, or planned for."
Thus, 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 generally raise equitable arguments to argue for a
low penalty and citizens often rebut such arguments. Therefore, as a practical matter, EPA does
not expect the affirmative defense provision to materially affect the practice of Clean Air Act
enforcement.
Additionally, EPA disagrees with commenters who asserted that the affirmative defense
is not a reasonable interpretation of the statute. 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 EPA's affirmative defense. This reflects 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, EPA's view is that
it would be unfair to impose a penalty no matter the size of the business.
EPA also disagrees that the affirmative defense provision inappropriately shifts the
burden of proving or disproving the elements of a violation to the regulated source. The
affirmative defense does not change the burden of proof with respect to establishing a violation.
The burden of proof remains with the plaintiff in an enforcement action. The affirmative defense
is relevant only after a violation has been established.
With respect to the comment that the affirmative defense "should be stated instead in
terms that, once a source has claimed that its excess emissions were related to a malfunction, it
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will not be considered to be in violation of the standards unless the enforcement authority
demonstrates that the source is not entitled to claim the malfunction," EPA's does not agree that
the affirmative defense should operate as the commenter suggests. The commenter improperly
seeks to shift the burden of proof from the source to EPA. It is the source, not EPA, that has the
information relevant to assess whether a particular event qualifies as a malfunction and meets the
affirmative defense. Furthermore, commenter's suggested approach appears to be similar to the
scheme that the court vacated in the Sierra Club case, in that there would be no violation unless
the enforcing party (EPA or a citizen), established that the event in question was not a
malfunction.
Comment: One commenter (91.1) stated that it is not clear what the affirmative defense
covers. In the Proposed Rule, EPA states that the affirmative defense is "to a claim for civil
penalties for exceedances of such standards that are caused by malfunction, as defined in section
60.2." The commenter (91.1) asked whether the term "civil penalties," which is not defined in
the Proposed Rule, is intended to apply as well to a "civil administrative penalty" imposed by
EPA under CAA section 113(d) (the term "civil penalty" in other contexts means only penalties
imposed by a court). The commenter (91.1) also asked whether the affirmative defense apply to
"noncompliance penalties" under CAA section 120 (which apply, inter alia, to noncompliance
with a section 111 NSPS). The commenter (91.1) stated that to meet the purported purpose of
the affirmative defense, which is to provide relief from emission limitations that cannot be met at
times even with equipment that is properly designed and maintained (see 75 Fed. Reg. 63,283
col. 2), the affirmative defense would need to apply to civil and administrative penalties,
including noncompliance penalties.
Response: The affirmative defense applies to civil penalties, including civil
administrative penalties and penalties under section 120, but does not apply to injunctive relief.
Comment: One commenter (91.1) stated that the reference in 40 CFR 60.4861 (noting
that nearly identical language is also included in proposed Subpart MMMM) to the definition of
"malfunction" in section 60.2 is confusing, and its purpose is unclear, given that the proposed
SSI standards themselves contain a definition of "malfunction" (see proposed 40 CFR 60.4930).
The commenter (91.1) argued that the definition in itself is unclear, since it states that: "During
periods of malfunction the operator shall operate within established emissions and operating
limits and shall continue monitoring of all applicable operating parameters until all waste has
been combusted or until the malfunction ceases, whichever comes first." The commenter (91.1)
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stated that this language, indicating that an event can only be a malfunction if the source operates
within its normal emission limitations, is circular and nonsensical and must be removed.
Response: We have revised the definition of malfunction in 60.4930 to be the same as
the definition of malfunction in 60.2. We made similar changes to the Emission Guidelines.
Comment: One commenter (91.1) stated that it is unclear how the affirmative defense
would apply to enforcement actions by state and local governments, or to private citizen
enforcement actions under CAA section 304. The commenter (91.1) stated that the preamble to
the Proposed Rule, for example, speaks only in terms of application of the affirmative defense in
an EPA enforcement action (See, e.g., 75 Fed. Reg. at 63,283 co. 2). The commenter (91.1)
recommended that an affirmative defense should clearly state that it is applicable to enforcement
actions by states or citizen-suit plaintiffs, as well.
Response: The affirmative defense is available in any action to enforce the standards set
forth in this rule, whether such action is brought by EPA, a state or local authority or a citizen.
Although the preamble's reference to the "Administrator" may have caused some confusion,
there is nothing in the language of the regulatory text establishing the affirmative defense that
suggests that the affirmative defense is limited to EPA enforcement actions.
Comment: One commenter (91.1) pointed out that the preamble to the Proposed Rule
does not give any explanation for why the affirmative defense would not apply to injunctive
relief. The commenter (91.1) added that if in fact the excess emissions associated with the
equipment or process failure are not reasonably preventable, then there is no apparent reason
why injunctive relief should be available either. The commenter (91.1) stated, as a matter of law,
injunctive relief may not be available in cases where a civil penalty cannot be imposed (See
Sierra Club v. Otter Tail Power Co., 615 F.3d 1008 (8th Cir. 2010)); under concurrent remedy
doctrine, injunctive relief for a CAA violation is barred when civil penalty is barred by statute of
limitations. The commenter (91.1) argued that maintaining liability for injunctive relief renders
the affirmative defense particularly ineffective with respect to citizen suits. The commenter
(91.1) stated that if the source is even potentially subject to injunctive relief, and therefore could
be required to pay the citizen-plaintiff s attorneys fees even if the source successfully
demonstrated that it otherwise qualified for the affirmative defense, then the affirmative defense
would not accomplish EPA's stated objective of providing relief in situations where the emission
limitations cannot be met despite proper design and operation of process and control equipment.
Moreover, the commenter (91.1) contended that EPA has provided no analysis that would
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supersede its previous and long-standing determination that it is not desirable to rely on
enforcement, rather than regulatory language, to address the inability to comply with section 111
performance standards during SSM events (referenced 37 Fed. Reg. 17,214, 17,214 (Aug. 25,
1972). See also Marathon Oil Co. v. EPA, 564 F.2d at 1273). The commenter (91.1)
recommended EPA, at a minimum, state that the affirmative defense applies to civil penalties,
civil administrative penalties, noncompliance penalties, and injunctive relief. The commenter
(91.1) also recommended that EPA reword the "affirmative defense," so that it states that a
source "will not be deemed in violation of the Part LLLL or Part MMMM standards for excess
emissions unless the event, and the source's response to the event, do not meet the criteria
spelled out in the regulations (referenced Cf 40 CFR §80.613); configured in that way, this
provision for malfunction should be called something other than an "affirmative defense," such
as an "alternative standard for SSM events". The commenter (91.1) stated that if EPA refuses to
set alternative emission standards that apply during SSM periods and continues to rely instead on
the proposed affirmative defense, the affirmative defense must be substantially modified for it to
provide any significant relief. The commenter (91.1) stated that the affirmative defense needs to
state clearly that a source that qualifies for the affirmative defense shall not be deemed to have
violated the applicable standards during that time; if EPA does that, it may be unnecessary to
state also that the affirmative defense relieves the source from liability for all types of penalties
and injunctive relief (save criminal penalties), but that should be the clear effect of qualifying for
the affirmative defense.
Response: EPA agrees that in some cases, injunctive relief may not be appropriate if all
the criteria of the affirmative defense have been satisfied. In such cases, liability for attorney's
fees is not a real issue. However, some form of injunctive relief may be appropriate. The
Sierra Club v. Otter Tail Power C.o case cited by commenters is not on point and does not
undermine EPA's ability to limit the affirmative defense to penalty claims. The concurrent
remedy doctrine provides that where a party's legal remedies are time-barred a party's concurrent
equitable claims generally are barred. The affirmative defense is not a time-bar to civil penalties.
EPA does not agree with commenters that the affirmative defense should operate such
that if the criteria are met, there is no violation and thus should be re-labeled as an alternative
standard for malfunction periods. For the reasons discussed in the preamble and elsewhere is
this response to comment document, EPA is not setting alternative standards for malfunctions.
The federal register notice cited by commenters is almost four decades old and does not reflect
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subsequent amendments to the Clean Air Act and court decisions. In any event, the federal
register notice merely states EPA's preference at that time for adopting regulations in order to
formalize an approach to excess emissions caused by malfunctions. EPA explained its view that
such an approach was preferable to an informal enforcement discretion approach for the
following reasons: "First, the existence of a formal process better informs the public of the
policy and factual issues which will underlie enforcement of the standards. Second, affected
industries which are making good-faith efforts to meet the standards will on the whole welcome
a regularized means of informing the Agency in detail of the circumstances surrounding
unavoidable emission excesses. Third, the Agency expects to benefit substantially from the
information it will gain about the operation of the processes in question, for both future
enforcement and standard setting." 37 Fed. Reg. 17,214, 17,214-15 (Aug. 25, 1972).
The affirmative defense is not an informal enforcement discretion approach of the type
that EPA rejected in 1972 and provides the benefits associated with the formalized approach that
EPA identified in its 1972 proposal. The Marathon Oil decision cited by commenters interprets
provisions of the Clean Water Act that are different in nature than provisions governing
standards under section 129 of the Clean Air Act. However, Marathon Oil merely rejected an
informal enforcement discretion approach and suggested that EPA's approach be formalized.
(Marathon Oil Co. v. EPA, 564 F.2d at 1273 ). In fact, the affirmative defense comports with the
court's suggestion in Marathon Oil that EPA "place the burden on the permit holder of producing
the relevant data and proving that the upset could not have been prevented." Id
15.8 Operating Modes
Comment: One commenter (91.1) argued that EPA provides no explanation of how it
determined that malfunctions are not a distinct operating mode; and EPA offers no explanation
of how it determined that, even though it believes malfunctions are not a distinct operating mode,
emissions during malfunctions should not be used to characterize the source's operating mode.
The commenter (91.1) agreed with EPA's conclusion that the factual complexity of differing
processes and of the severity, frequency, and duration of malfunctions makes standard-setting
difficult. The commenter (91.1) stated that it is often impossible to gather emission data during
malfunctions (either for standard-setting or for compliance demonstration purposes). The
commenter (91.1) stated that malfunctions are by definition unexpected, so it is not possible to
plan to have test equipment in place to measure emissions when one occurs; and even if test or
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monitoring equipment is in place, emissions during malfunctions often are not routed to a stack
where they can be measured, and upsets during stack testing invalidate the test results under
EPA's approved test methods. Another commenter (97.1, 127.1) disagreed with EPA's newly
articulated view that malfunctions are not distinct operating conditions from steady-state
operations. The commenter (97.1, 127.1) stated that SSI operators must treat malfunctions as
very distinct events from steady-state operations, depending on the severity of the malfunction
requiring anything from shutdown of the unit to emergency fire response actions. The
commenter (97.1, 127.1) stated that depending on the nature and severity of the malfunction
event, emissions often are not capable of being captured and routed to a stack for control and/or
measurement and, when they are, test methods do not adequately account for the often short-term
and unstable characteristics of the malfunction event.
One commenter (76.1) does not agree that 129 standards should apply during a scheduled
startup, shutdown, or break down. However, the commenter (76.1) agreed with EPA that a
malfunction is not a distinct operating mode and that 129 standards should apply during a
malfunction. The commenter (76.1) stated that this is consistent with the local Bay Area Air
Quality Management District (BAAQMD) enforcement policy such that if a malfunction was
unforeseen and not caused by a negligent act, BAAQMD has a procedure in place to grant relief
from the emission limit, called "Breakdown Relief. The commenter (76.1) said that instances of
break down are rare and usually include an inspection from local regulators, thus making the
break down relief designation a verifiable non-negligent designation for a true failure. The
commenter (76.1) recommended EPA grant relief for startup, shutdown, and breakdown because
even the best run plants have unforeseen conditions and "Acts of God" that create a need for
break down relief.
Response: EPA's rationale for its treatment of malfunctions is explained in the preamble
and elsewhere in this response to comment document. For the reasons described in the above
responses, EPA's approach to malfunctions is consistent with section 129 and is a reasonable
interpretation of the statute. EPA does not disagree with commenters statements concerning how
operators react to malfunctions or the issues associated with treatment or control of emissions
associated with malfunctions. EPA has structured the affirmative defense to take into account
these issues and to provide relief from civil penalties where appropriate.
Comment: Some commenters (118.1, 122, 123) stated that the definitions in the
proposed rule for startup and shutdown seem to be somewhat confusing and potentially
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burdensome, and could result in significant undue wear and maintenance on equipment. The
commenters (118.1, 122, 123) stated that in a MH SSI system, when sludge is not being fed to
the incinerator for reasons such as preventative maintenance or simply lack of sludge, the best
procedure or condition for "coasting" the incinerator during those periods of time is to reduce the
temperatures in the incinerator to a level lower than temperatures during actual combustion, and
to cease the flow of air through the pollution control equipment (this is considered "warm stand-
by"). The commenters (118.1, 122, 123) said that continuing to keep the hearths warm, and in
particular the refractory, prevents the contraction and expansion of these components during a
cold startup and a total shutdown that would include the constant cessation and commencement
of burner firing. The commenters (118.1, 122, 123) contended that all MH manufacturers' will
confirm that the "warm stand-by" mode enhances and lengthens the life of the incinerator and
reduces costly maintenance and downtime. The commenters (118.1, 122, 123) stated that the
definition of startup infers that the burners are off, and that as soon as the burners are turned on,
all pollution control equipment must already be operational; and argued that this is contradictory
and confusing in that the definition of shutdown does not include the de-activation of the burners
(therefore, the indication is that once the sludge has been combusted, we have shutdown and
should no longer be required to monitor). The commenters (118.1, 122, 123) noted that EPA's
definition of shutdown does not suggest that it is necessary to de-activate the auxiliary fuel
burners; and stated that since the major concern of the emission guidelines is the removal of
pollutants from the exhaust gases caused by the combustion of sludge, this definition appears
sufficient and appropriate, and the monitoring and averaging of emissions and operational data
should stop once the sludge is no longer being charged to the incinerator. The commenters
(118.1, 122, 123) recommended to not include the activation of the burners in the definition of
startup, but rather to use a definition that defines startup as that period of time when sludge is
first charged to the incinerator.
Response: In the proposed and final rules we have required that emission limits apply at
all times, including startup and shutdown. Shutdown has been defined as the period of time after
all sewage sludge has been combusted in the primary chamber. Startup means the period of time
between the activation, including the firing of fuels (e.g., natural gas or distillate oil), of the
system and the first sewage sludge feed to the unit. We maintain these are appropriate, and
neither definition prevents operators from running SSI units on "warm stand-by" mode.
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16.0 DELEGATION OF AUTHORITY
Comment: In regards to proposed §60.5045 (the provision that would allow states to
request delegation of the Federal Plan), the commenter (55) stated that they generally prefer for
the state (not EPA) to be the implementing agency for federal standards. The commenter (55)
stated that they often have only one or two existing facilities that are subject to Emission
Guidelines promulgated by EPA; and provided examples of affected facilities that closed
because of certain Emission Guidelines that were adopted via a state plan (approved by EPA).
The commenter (55) stated that if proposed rule §60.5045 is promulgated, they will have the
option of requesting delegation of the federal plan eliminating the time consuming path of
adopting rules and preparing a state plan, yet still allowing states the implementing authority.
Response: The commenter is correct that EPA will develop a federal plan the states can
use.
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17.0 STATE PLANS
Comment: One commenter (57, 597) stated that they operate two multiple hearth
incinerators that have a CO concentration permit limit imposed by New Jersey Department of
Environmental Protection (NJDEP) of 100 ppm @ 7% ©2 based on a rolling one hour limit. The
commenter (57, 597) is concerned that the proposed emission limit of 3,900 ppmvd @ 7% O2is
less stringent than the existing NJDEP imposed limit and it would be considered
"antibacksliding".
Response: State and local regulatory agencies may have stricter emission limits based
on state and local needs. The final emission standards are based on emissions information
gathered from facilities located in a mix of northern, southern, eastern, and western states, and
represent the emissions achievable by the best-performing of these facilities on a national level.
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18.0 IMPACTS ANALYSIS (EXCLUDING SMALL BUSINESS AND
LANDFILLLING IMPACTS)
18.1 Total Cost is Incorrect
Comment: Several commenters (61.1, 83.1, 96.1) stated that EPA overstated the benefits
of the proposed standards or that the cost, cost-benefit, and operational impacts were flawed.
Many commenters (61.1, 83.1, 89.1, 90.1, 113.1, 132.1, 136.1) stated that EPA underestimated
the emission control costs and overestimated the baseline emissions from existing SSIs. Some
commenters (61.1, 83.1) stated that EPA understated the compliance costs; specifically,
commenters (83.1, 138) stated that the $225 million capital cost estimate provided by EPA was
too low, and one commenter (83.1) provided an estimate of $8-10 million (capital cost) for an
individual facility. The commenter (83.1) noted that due to costs, the estimated benefit makes
implementation of the new rules unreasonable. Other commenters (83.1, 102.1, 116.1) stated the
belief that EPA is basing the rule on faulty data and/or improper assumptions and stated that the
emission calculations are off by an order of magnitude; these commenters requested that EPA
reissue the cost-benefit analysis. One commenter (48.1) contended that the cost estimate for
response to the regulation could not be correct. The commenter cited the estimated cost that
would be incurred at their facility in comparison to the total estimated cost. Another commenter
(134.1) provided their own estimate of the total cost for all incineration facilities to comply. The
commenter (134.1) stated that the total capital cost provided, $2.6 billion, accounts for the
addition of caustic to existing wet scrubbers, a wet electrostatic precipitator for fine paniculate
removal, a heat recovery device to increase the flue gas temperature above the dew point, and an
increase in the size of the ID fan.
Response: EPA has re-evaluated the control options for SSI units and has incorporated
data corrections and methodology revisions into revised cost analyses. Please see the preamble to
the final SSI rule, and the memoranda "Post-Proposal SSI Database Revisions and Data Gap
Filling Methodology", "Revised Cost and Emission Reduction of the MACT Floor Level of
Control", and "Revised Analysis of Beyond the Maximum Achievable Control Technology
(MACT) Floor Controls for Existing SSI Units" (EPA-HQ-OAR-2009-0559) for further
discussion regarding the revised cost estimates and control considerations.
Comment: A commenter (48.1) stated that the cost of compliance for the 112 facilities
was stated as $105 million, but that there was no time value associated with the cost. The
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commenter added that at a minimum a cost estimate should have a clear and consistent
accounting of the number of facilities to which costs would be incurred.
Response: Both capital and annual compliance costs were estimated and the $105
million was the annual cost, in dollars per year, estimated for facilities to comply with the
proposed standards. EPA has re-evaluated the control options for SSI units and has incorporated
data corrections and methodology revisions into revised cost analyses. The annual cost for
compliance with the revised standards is approximately $17.8 million/yr. The cost estimates
account for costs expected to be incurred for each unit to comply with the proposed standards.
Please see the memorandum "Revised Cost and Emission Reduction of the MACT Floor Level
of Control" (EPA-HQ-OAR-2009-0559) for further discussion regarding the revised cost
estimates and control considerations. The tables associated with this memo list cost details for all
facilities in the known SSI inventory.
18.2 Compliance Assumptions are not Representative of Current Facilities
Comment: Some commenters (71.1, 138) stated that EPA used assumptions and other
factors from other rules for units that have no similarity to SSIs and that burn wastes that are not
similar to sewage sludge in the development of the proposed rule. Commenters asserted that this
has resulted in an underestimation of compliance costs and local financial impacts. One
commenter (48.1) specifically stated that considering sewage sludge as a solid waste mandates
that the waste be subject to the best available control technology (BACT) for solid waste; the
commenter (48.1) urged the Agency to consider the compatibility of BACT used for the solid
waste designation with the sewage sludge incineration processes, for which, the commenter
indicates, the BACT were never intended.
Response: EPA disagrees with the commenters. Cost algorithms were modified to be
applicable to SSIs. The commenter is mistaken regarding the use of BACT. Please refer to the
Section 129 requirements of the CAA.
Comment: One commenter (129.1) asserted that EPA personnel have incorrectly
indicated that all of the existing SSIs will meet all of the proposed emissions guidelines. The
commenter (129.1) stated that the data used to determined compliance with the current
regulatory emission limits is extremely old and is not reflective of the number of improvements
that have been made to SSI operating systems; the commenter (129.1) stated that this makes it
very difficult to determine how many existing SSIs will be impacted by the proposed emission
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guidelines. The commenter (129.1) provided results for testing conducted on their multiple
hearth incinerators in the mid 1990s, and remarked that the units were not in compliance with the
proposed cadmium, mercury, oxides of nitrogen, lead and sulfur dioxide limits; the commenter
stated that new testing would be required to determine compliance with the proposed limits.
Response: EPA disagrees with the commenter. Emissions data used to determine the
MACT floor limits came from tests conducted from 2000 to 2010; most of the tests were
conducted from 2009 through 2010. EPA expects that many units would be able to comply with
the proposed limits, and that those who cannot would be able to meet them after installing the
appropriate pollution control systems.
Comment: One commenter (134.1) stated that the proposed impacts are not
representative of an 8760 hour annual operating time and fail to include variations in wastewater
solids quantity and quality, normal operating variations, and variances during startup, shutdown,
and malfunction.
Response: EPA notes that the proposed costs and impacts are estimates. Based on data
received during the ICR process and the comment response period, many SSI facilities do not
run their incinerators full time (8760 hours per year). The impacts (emission reductions,
secondary impacts, and compliance costs) estimated for the standards are based on the annual
operating hours provided by surveyed facilities in addition to data received during the comment
periods. The development of the parameters used in the emissions and cost analyses are
explained in the memorandum "Post-Proposal SSI Database Revisions and Data Gap Filling
Methodology" (EPA-HQ-OAR-2009-0559). EPA does not have any data on wastewater
variability.
18.3 Cost per Pound of Pollutant is Too Low
Comment: Commenters (83.1, 76.1, 87.1) stated that because emissions were over-
estimated, the cost per pound of pollutant reduced is too low. One commenter (83.1) added that
this issue, in and of itself, is a sufficient basis to withdraw the Proposed Rule. One commenter
(138) stated that although the proposed rule estimates the incremental cost of adding activated
carbon to all multiple hearth incinerators to be six thousand dollars ($6,000) per pound removed,
their own costs estimates reflect a value of one hundred thousand dollars ($100,000) per pound
removed or higher. Another commenter (138) stated that EPA's cost data for mercury controls is
unreasonably low at $6,000 per pound of mercury removed and a total annualized cost of
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$105,000,000 for all currently operating units to comply with the proposed standards. The
commenter (138) also predicted the cost of mercury removal to be one hundred twenty-five
thousand dollars ($125,000) per pound of mercury removed. The commenter stated that using
this cost results in an annual cost of almost four million dollars ($4,000,000) to remove thirty-
one point five (31.5) pounds of mercury. The commenter also stated that the actual costs of
compliance are expected to be more than twenty (20) times those estimated by the EPA.
Other commenters (105.1, 118.1) stated that based on the initial calculations of one utility,
additional mercury reductions from current levels could cost more than $190 million per ton.
One commenter (93.1) provided a conservative estimate of a cost effectiveness of $39.6 million
per ton of mercury removed.
Another commenter (76.1) stated that EPA did not provide a cost benefit analysis for the
reduction in mercury. The commenter (76.1) estimated the cost for mercury reduction to beyond
the MACT floor as $334,797 per pound of mercury reduced with the actual total cost for
mercury reduction by all SSIs in the Unites States at $1,042,959,614. Commenters (76.1) stated
that if they were accurate, it is likely that EPA costs for social benefits would drop because those
costs were based on numbers that were estimated too high. The commenter (76.1) recalculated
the social benefit for this regulation at $181,708,953, stating that the cost to comply is 5.73 times
the estimated social benefit, making the rule unreasonable.
Additionally, one commenter (138) stated that the EPA analysis does not justify the
additional mercury removal or the installation of a carbon system. The commenter (138)
provided a capital cost for one carbon system for five facilities of $2.5 million per unit, which is
equivalent to the cost of $57.7 million per ton removed. The commenter (138) stated that the
mercury removal cost is potentially five to ten (5-10) times low. Another commenter (97.1,
127.1) stated that the average mercury removal cost for them would be more than $100,000 per
pound of mercury removed. The commenter (97.1, 127.1) stated that the City of Palo Alto
Regional Water Quality Control Plant conducted a similar cost analysis that put the national cost
of mercury removal at nearly $190,000 per pound, and over $400,000 per pound for the City
based on its actual emissions level.
Response: After revising the emissions data set and associated default parameters based
on data corrections submitted during the comment period, EPA has revised its baseline emission
estimates (see the memorandum "Revised Estimation of Baseline Emissions from Existing
Sewage Sludge Incineration Units"( EPA-HQ-OAR-2009-0559) for details). Consequently,
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emission reduction estimates and cost-effectiveness were also re-evaluated for the MACT floor
and beyond-the-floor options. Additionally, EPA has re-evaluated the applicable control options
for each pollutant. Based on these results, EPA has decided not to go beyond-the-floor for
mercury. Please see Section V, Part E of the preamble for EPA's more detailed response to these
concerns.
Comment: One commenter (138) is concerned about the proposed requirement to use a
beyond the MACT floor mercury concentration limit of 0.02 milligrams of mercury for the
existing MH furnaces, and stated that the limit is 85% below the MACT floor mercury
concentration limit. The comm enter (138) suggests the below the MACT floor mercury
concentration limit is far more costly than noted in the proposed rule, and is not justified by any
scientific documentation provided to the public as part of the rulemaking process. One
commenter (90.1) claimed that the beyond the floor limit for mercury must not be in the final
rule because the cost per ton removed is not defensible given that the risk estimated by EPA due
to mercury exposure is grossly overstated.
Response: After revising the emissions data set and associated default parameters based
on data corrections submitted during the comment period, EPA has revised its baseline emission
estimates (see the memorandum "Revised Estimation of Baseline Emissions from Existing
Sewage Sludge Incineration Units"( EPA-HQ-OAR-2009-0559) and "Post-Proposal SSI
Database Revisions and Data Gap Filling Methodology"( EPA-HQ-OAR-2009-0559)for details).
Consequently, emission reduction estimates and cost-effectiveness were also re-evaluated for the
MACT floor and beyond-the-floor options. Additionally, EPA has re-evaluated the applicable
control options for each pollutant. Based on these results, EPA has decided not to go beyond-the-
floor for mercury. Please see Section V, Part E of the preamble for EPA's more detailed response
to these concerns.
18.4 Assumed Level of Control for Metals is Too High
Comment: One commenter (145.1) stated that the 95% removal efficiency used for a
combination of venturi and impingement plate scrubbers is unrealistic. The commenter stated
that the EPA cost estimates assumed that all MH incinerators equipped with a combination of
venturi and impingement plate scrubbers have an average Cd controlled emission rate of
0.044557 mg/dscm, which is lower than the MACT standard of 0.095 mg/dscm. The commenter
noted that this was back-calculated from the assumed uncontrolled concentration of Cd with an
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assumed control efficiency of 95% for a combination of venturi and impingement plate scrubber.
The commenter is of the opinion that the 95% removal efficiency for a combination of a venturi
and impingement plate scrubbers is too optimistic for some MH incinerators, especially those
located in the industrial areas. Another commenter (145.1) questioned if technology exists for the
90% to 95% mercury removal from flue gases exiting from primary scrubbers.
Another commenter (49.1) stated that outdated venturi scrubbers were installed on
multiple hearth and fluid bed incinerators in the 1960's thru early 1980's and are not effective in
removing submicron particles, which are enriched with high concentrations of heavy metals. The
commenter (49.1) stated that new scrubbers are needed to reduce submicron particles and metal
emissions. The commenter estimated that if electrostatic precipitators or high efficiency Venturi -
Pak are installed on MH incinerators, then heavy metal emissions can be reduced by 90%.
Response: The commenter did not provide data for EPA to revise its estimates. When
data corrections were provided by commenters, we incorporated them into our analyses where
appropriate. We have revised our analysis of MACT and beyond-the-floor control options;
please see the memoranda "Revised Cost and Emission Reduction of the MACT Floor Level of
Control" and "Revised Analysis of Beyond the Maximum Achievable Control Technology
(MACT) Floor Controls for Existing SSI Units" (EPA-HQ-OAR-2009-0559) for details.
18.5 Required Controls and Associated Costs are Inaccurate
Comment: Some commenters (68.1) stated that EPA has made blanket assumptions
regarding applicability of emissions controls for all SSI installations which may not be
appropriate for specific facilities. Several commenters (87.1, 74.1, 78.1, 81.1, 68.1, 69.1, 108.1,
103.1, 102.1, 116.1, 113.1, 114.1, 105.1, 112.1, 129.1) asserted that EPA has underestimated the
cost of the emissions controls that will be necessary to meet the proposed standards. Commenters
(87.1, 74.1, 78.1, 81.1, 68.1, 70.1, 69.1, 103.1, 102.1, 116.1, 113.1, 114.1, 115.1, 83.1, 105.1,
112.1) stated that EPA has incorrectly assumed that existing multiple hearth incinerators will
only need to inject activated carbon into the exhaust system to reduce mercury and dioxin
emissions. Commenters (134.1) stated that numerous facilities have reviewed past emission test
results and have indicated that they would require additional emission control equipment. At
least two commenters (87.1, 112.1) provided actual emissions data indicating that their WWTP
incinerators would most likely not reliably meet the proposed standards for NOx, SO2, Pb, Cd
and Hg. The commenters also provided data for the anticipated additional control systems that
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would be required for control of SC>2, Pb, Cd, and Hg and the associated equipment costs.
Commenters (121.1) stated that the emission controls to decrease pollutant concentrations to the
required levels will necessitate multiple technologies, will be very costly, and still may produce
discharges that are unable to meet the proposed standards.
At least six commenters (87.1,70.1,69.1, 102.1, 116.1, 113.1, 114.1,83.1, 105.1, 112.1)
stated that their SSIs would also need a contact chamber, fabric filter, and additional ductwork,
or alternatively another emission control altogether to achieve the proposed levels of mercury
emissions. One commenter (138) asserted that they would actually need to install a powdered
activated carbon injection system, a fabric filter baghouse, a high efficiency condensing
scrubber, and a granular activated carbon packed bed in order to meet the mercury limits. One
commenter (76.1) believed that all of their MHFs would need modified afterburners, activated
carbon injection systems, fabric filters, and packed bed scrubbers to control mercury to beyond-
the-MACT-floor limit. One commenter (103.1) indicated that mercury control will also require a
mechanism to remove the carbon without recycling back to liquids treatment (baghouse or
equivalent) and some mechanism to cool the gas prior to the baghouse; the commenter provided
a cost estimate of $25 million for adding this equipment to existing incinerators. Another
commenter (105.1) provided estimates for construction costs of a carbon injection based system
including a heat recovery system (noting that this would be necessary to cool the flue gas) and
fabric filters of $21,528,000; the commenter also estimated construction costs for fixed-bed
carbon adsorption with pre-conditioning system at $4,352,000. One commenter (114.1) stated
that mercury controls for their facility are preliminarily estimated at a capital cost of $1-52
million. One commenter (116.1) provided an estimate of $4.8 million for a carbon adsorption
system, secondary heat exchanger, fans, and other applicable flue piping, with design and
installation costs of $9-10 million for one fluidized bed incinerator. One commenter (106.1)
provided that the proposed standards would require the addition of a large activated carbon bed,
an SNCR for NOX, a wet ESP to remove submicron particulates, and the addition of caustic to
the existing water scrubber to meet the mercury, NOX, Lead, Cadmium and SO2 limits; the
commenter stated that this would require an investment of over $20 million and have substantial
annual operating costs for replacement of the carbon, higher electrical consumption, and other
chemicals. Another commenter (110.1) stated that for carbon injection to function their SSI unit
would also require a fabric filter, two heat exchangers, and a boiler. One commenter (71.1) stated
that an upgraded PM control system, an acid gas control system, and possibly a NOX reduction
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system would be needed to meet the proposed standards ; the commenter (71.1) believed that the
costs of these upgraded emission controls would be substantial and in the millions of dollars.
One commenter (121.1) expressed concern that their facility would require activated carbon
injection, a baghouse, a venturi pak or ring jet scrubbers, and wet electro static precipitator
controls, or an impingement tray scrubber, a wet electro static precipitator, and an activated
carbon polishing step to meet the proposed standards. Another commenter (138) stated that they
would require advance emission controls for both mercury and new opacity limits. Commenters
(122, 123) stated that the proposed standards would require the expenditure of significant funds
to install additional pollution control equipment that is either untested, marginally effective, or
impossible to install due to the design configuration of the existing equipment.
Response: EPA has revised emission limits, as well as the associated beyond-the-floor
analysis. Please see Section V Part F of the preamble for EPA's response to the concerns of these
commenters. At proposal, and for the final standards, EPA estimated costs and emissions
reductions based on the best information available. EPA acknowledges that the inventory
database did not have complete information for all SSI units. Consequently, EPA developed
defaults for flue gas flow rate, hours of operation, sludge capacity, and other inputs for the
proposed rule. EPA has updated analyses using data provided by the commenters. However, for
a number of inputs, EPA has still assigned default values where data were not available for each
SSI. For the final rule, EPA has correlated some of the defaults to populations served by the
facilities in order to better estimate costs and emission reductions more specifically to each
facility. Sources will have the best idea of the costs of controls for their site specific conditions.
For some sources, the costs and emission reductions estimated by EPA may be higher than what
the source estimates, and for others they will be less. EPA's estimates are estimates based on the
best information available to us. We also note that the MACT floor costs and emission
reductions, and determination of the number of sources estimated to require control, estimated
for the final rule are also based on the revised MACT floor limits.
Comment: One commenter (102.1, 116.1) stated that the estimates for control costs
provided by EPA were "not on target" for costs associated with compliance or costs on the
capital construction side. The commenter (102.1, 116.1) stated that the estimate by EPA to
achieve compliance is $200,000; the commenter (102.1, 116.1) provided a cost estimate for
carbon adsorption systems and peripheral support equipment of $4.8 million, with total capital
costs in the $8-10 million range. Another commenter (138) provided equipment cost estimates of
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$5 million for an activated carbon injection system, with design and installation costs adding
another $5 million. The commenters (102.1, 116.1, 138) stated that if they are among the top
12% and facing $8-10 million in capital costs, there is a high degree of likelihood that other FBI
sites will face higher capital investments to achieve full compliance with the proposed standards.
Response: At proposal, and for the final standards, EPA estimated costs and emissions
reductions based on the best information available. EPA acknowledges that the inventory
database did not have complete information for all SSI units. Consequently, EPA developed
defaults for flue gas flow rate, hours of operation, sludge capacity, and other inputs for the
proposed rule. EPA has updated analyses using data provided by the commenters. However, for
a number of inputs, EPA has still assigned default values where data were not available for each
SSI. For the final rule, EPA has correlated some of the defaults to populations served by the
facilities in order to better estimate costs and emission reductions more specifically to each
facility. For the final standards we have also revised the types of controls costed to meet the
MACT floor limits. For SSI's that we estimate will need further control of PM, Cd, or Pb to meet
the MACT floor, we have costed out wet ESP as a more appropriate PM control for high
moisture streams. We have also costed out SNCR for SSI's that we estimate will need further
control of NOX to meet the MACT floor limits. As at proposal, we have costed out packed
scrubbers for SSI's that we estimate will need further control of HC1 or SC>2. At the MACT floor
level, we do not estimate that any SSI's will need to add control for Hg, PCDD/PCDF, or CO. A
detailed discussion of the costs and emissions reductions estimates for the final standards is
provided in the memorandum "Revised Cost and Emission Reduction of the MACT Floor Level
of Control" in the SSI docket (EPA-HQ-OAR-2009-0559).
Sources will have the best idea of the costs of controls for their site specific conditions.
For some sources, the costs and emission reductions estimated by EPA may be higher than what
the source estimates, and for others they will be less. EPA's estimates are estimates based on the
best information available to us. We also note that the MACT floor costs and emission
reductions, and determination of the number of sources estimated to require control, estimated
for the final rule are also based on the revised MACT floor limits.
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18.6 Actual Costs to Upgrade are Too High
Comment: Several commenters (58, 102.1, 116.1) claimed their costs to upgrade their
incinerators would be too high. Two commenters (102.1, 116.1) stated that several facilities will
be required to install extremely high dollar advanced control technology solutions on the exhaust
systems of currently existing incineration units in order to meet the proposed standards. The
commenters (102.1, 116.1) provided equipment supplier and engineering estimates indicating
capital improvements on the order of $28-32,000,000 to equip units with the control technology
required to meet the stringent requirements of the Proposed Standard. One commenter (72.1)
estimated that the costs for adding the advanced control equipment that was used for the St. Paul,
MN and the Ypsilanti, MI applications for fluid bed incinerators is estimated to be about $6.6
million for a single new fluid bed incinerator burning 72 dry ton/day of sewage sludge. Another
commenter (73.1) estimated in-house upgrades to cost approximately $5MM per process train,
and expressed concerns regarding the available space at the facilities to install such upgrades.
One commenter (103.1) provided annual operating costs for chemicals (carbon and ammonia),
O&M (additional air pollution control equipment and support systems) and capital costs
associated with major modifications to two multiple hearth incinerators (estimated at $25 million
capital and $200,000 per year O&M). Another commenter (138) provided a cost estimate of
$60,000,000 for advanced emissions control for ten (10) incinerators.
One commenter (102.1) expressed concerns regarding the cost of upgrades for the
Metropolitan Sewerage District of Buncombe County, NC, based on the unique nature of their
process, including the high nitrogen content in their sludge residuals as well as the use of natural
gas as a supplemental fuel source. The commenter (102.1) provided anticipated costs for the
upgrade to a carbon injection/absorption and fabric filter system to the order of $5+ million for
equipment and $10+ million for design and installation. Another commenter (115.1) remarked
that the proposed SSI regulations will add $5-10M to construction costs. The commenter (115.1)
stated that future operational and maintenance costs of the air pollution control equipment
required to meet proposed standards are expected to be significant and are a tremendous burden,
as they add to existing costs already required for flood recovery and normal operations and
maintenance.
One commenter (69.1) cited current control costs of close to one billion dollars over the
twenty to twenty five-years based on a consent order for CSO abatement and storm water. The
commenter (69.1) stated that the SSI regulation provides an additional cost burden that
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exacerbates the cost in sewer fees borne by already economically depressed communities.
Another commenter (75.1) stated that their facility already needed major upgrades, which exceed
one billion dollars, to an aging and undersized wastewater infrastructure to prevent sewer
overflows, and that EPA estimated that this proposed regulation will cost an additional 3.4
million dollars in annualized costs. The commenter noted that facilities would need to implement
rate increases to cover costs. The commenter (75.1) stated that it is imperative that EPA be sure
its SSI emission estimates and assumptions are accurate as possible to avoid costly upgrades that
provide little benefit.
One commenter (67.1) stated that their district is currently 90% complete on the design of
an $81 million water pollution control facility upgrade for nitrogen removal and related
improvements which were initiated in 2009, including a new state-of-the-art fluidized bed
incinerator to replace its aging, 24 year old fluidized bed incinerator. The commenter (67.1)
stated that the proposed new regulations would impose an additional $6.2 million in emissions
control capital improvements as well as the costs to install these improvements.
One commenter (114.1) stated if the proposed rules are implemented, the facility will
deflect to maintain existing technology rather than implementing newer technology with the
higher costs of greater removal requirements. The commenter (114.1) stated that under the
proposed standards, the 35+ year old MH incinerator is compliant with all emission limits but
mercury. The commenter (114.1) stated that removing the additional mercury will cost more to
ratepayers, and only ends up changing the media where it will occur (water vs. soil).
One commenter (126.1) provided annual operating and maintenance costs. The
commenter (126.1) stated that, for a 20 year recovery for capital funding at an interest rate of
4%, the annual operating and maintenance cost of the equipment required for continuous
compliance with the proposed NSPS for existing MHF SSIs at their facility is $1,474,678. The
commenter (126.1) further provided that the annualized cost of new APC equipment
($1,474,678) divided by the amount of mercury removed each year (0.00701 TPY) equated to an
annual present worth of $210 million per ton of mercury removed.
Response: EPA has revised the final limits, and after revising the emissions data set and
associated default parameters based on data corrections submitted during the comment period,
EPA has revised its cost estimates for MACT and beyond-the-floor control options. Please refer
to the memoranda "Revised Cost and Emission Reduction of the MACT Floor Level of Control"
and "Revised Analysis of Beyond the Maximum Achievable Control Technology (MACT) Floor
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Controls for Existing SSI Units" ( EPA-HQ-OAR-2009-0559) for details). Consequently,
emission reduction estimates and cost-effectiveness were also re-evaluated for the MACT floor
and beyond-the-floor options. Additionally, EPA has re-evaluated the applicable control options
for each pollutant. Based on these results, EPA has decided not to go beyond-the-floor for any of
the pollutants.
Comment: Commenters (131.1) stated that EPA greatly underestimated compliance costs
and local financial impacts of the proposed rule. At least one commenter (83.1) stated that if
EPA designates sewage sludge as a solid waste and requires the incinerators to comply with
CAA §129, many POTWs will lack the financial ability to upgrade their incinerators or will be
forced to shift to other options that are more costly than current requirements (for example,
landfilling or land application). The commenter (83.1) asserted that sewage sludge is already
currently highly regulated under EPA's existing Part 503 and CAA regulations. Another
commenter (83.1) provided a research brief and survey to emphasize that local city and county
governments currently suffer with tightening local budgets and reduced in the economic
downtown. The commenter (83.1) stated that to require ratepayers to bear the burden of
incinerator upgrades or other higher-cost options is unreasonable, and that the proposed rule does
an inadequate job of considering these local impacts. Another commenter (67.1) stated that
should not EPA finalize these proposed standards, they would impose an additional financial
burden upon The District and its served communities, in particular the City of New Britain,
Connecticut, a distressed community and The District's largest customer, representing 65% of
The District's budget.
Response: EPA has revised the final limits, and after revising the emissions data set and
associated default parameters based on data corrections submitted during the comment period,
EPA has revised its cost estimates for MACT and beyond-the-floor control options. Please refer
to the memoranda "Revised Cost and Emission Reduction of the MACT Floor Level of Control"
and "Revised Analysis of Beyond the Maximum Achievable Control Technology (MACT) Floor
Controls for Existing SSI Units" ( EPA-HQ-OAR-2009-0559) for details). Consequently,
emission reduction estimates and cost-effectiveness were also re-evaluated for the MACT floor
and beyond-the-floor options. Additionally, EPA has re-evaluated the applicable control options
for each pollutant. Based on these results, EPA has decided not to go beyond-the-floor for any of
the pollutants.
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18.7 Costs of Activated Carbon Injection are Inaccurate
Comment: Two commenters (97.1, 127.1) stated thatEPA's cost data assumes that
activated carbon can be injected upstream of existing particulate control devices, and does not
account for the installation of new fabric filters for each activated carbon injection system
installed. Commenters (97.1, 127.1) stated that activated carbon injection systems will require
baghouses to collect the carbon injected, and heat exchangers and/or boilers to reduce the
exhaust gas temperature below 400 degrees Fahrenheit. The commenter (97.1, 127.1) noted that
no existing MHIs are equipped with baghouses for particulate control; rather, the commenter
stated that existing MHI units employ wet scrubbers. Some commenters (134.1) expressed
concern that EPA did not include the cost of waste heat boilers, condensers, deaerators, boiler
feed water pumps, boiler feed water treatment or auxiliary equipment in those cases where a
fabric filter was added. The commenters (134.1) further remarked that unlike HMIWI, which can
cool their small flue gas volumes by bringing in ambient air or using water conditioning sprays, a
SSI must use a waste heat boiler to reliably cool its flue gas. The commenter (134.1) noted that
waste heat boilers are used on the three SSIs with fabric filters at the St. Paul Metro WWTP, but
were not included in the economic cost analysis.
One commenter (97.1, 127.1) further iterated that wet scrubbers can become clogged by
the injected carbon, and this carbon can also be released back into the POTW system through the
recycling of the scrubber water to the POTW headworks; the commenter stated that any units
equipped with ACIs will require the addition of a fan to pull the exhaust through the fabric filters
and a bag leak detection monitor. The commenter (97.1, 127.1) noted that EPA does not account
for these capital costs in its beyond-the-floor cost effectiveness analysis for mercury. The
commenter (97.1, 127.1) asserted that EPA must consider the annual operating costs of a
baghouse, the cost of replacement bags, the cost of electricity to operate fans large enough to pull
the exhaust through the fabric filters, and the mercury and other air emissions associated with the
generation of this electricity. The commenter (97.1, 127.1) estimated actual capital costs for
multiple hearth units will exceed $4 million per incinerator.
Another commenter (101.1) also noted that in EPA's cost estimate for mercury control,
particulate matter (PM) control devices for the removal of activated carbon injected into the SSI
exhaust were assumed to be already in place. The commenter (101.1) stated that wet scrubbing
with plant effluent water is the means of PM and acid gas control for most SSIs. The commenter
(101.1) further remarked that EPA failed to consider that the particulate captured is returned to
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the wastewater treatment plant's influent, therefore, mercury and other pollutants captured are
either lost to the effluent or recycled with the sludge back to the incinerator. The commenter
(101.1) stated that the cost estimate should include a fabric filter for all activated carbon injection
systems.
Commenters (97.1, 127.1) also stated that EPA failed to account for other costs
associated with mercury controls, including additional ductwork, heat exchangers and boilers,
and contact chambers. The commenter (97.1, 127.1) estimated $8-10 million for the minimum
equipment necessary: a carbon contact chamber and a baghouse for each incinerator, with total
capital costs for the 161 MH incinerators in the range of $1.3 - 1.6 billion or higher. The
commenter states that applying these mercury control costs to the actual site-specific mercury
content reveals extremely high cost effectiveness ratios. The commenter provided an average
mercury removal cost of more than $100,000 per pound of mercury removed.
One commenter (129.1) stated that EPA's estimate for the total cost to add simple
activated carbon injection for 163 multiple hearth incinerators (roughly $5 million) is unrealistic
for an entire activated carbon injection system, consisting of an activated carbon injection
system, carbon contact chamber, baghouse and heat exchangers and boilers to reduce the exhaust
gas temperature to below 350 deg-F prior to the injection point. The commenter (129.1) provided
cost information for the installation of a new fluidized bed incinerator equipped with a
proprietary activated carbon adsorbing system at the Ypsilanti, Michigan WWTP to reduce
mercury emissions; the capital cost to procure and install the system was roughly $3.5 - $4
million per incinerator (2009$). The commenter stated that the activated carbon would have to be
replaced once every three years. The commenter also provided an adjusted estimate (accounting
for increases in corrosion resistant metal costs and construction costs) for an activated carbon
injection system/baghouse of up to $8-10 million per system, based on bids at Metropolitan
WWTP in St. Paul, Minnesota. The commenter stated that these estimates do not include the cost
of additional space in a new facility, the cost to renovate or expand an existing facility, the cost
to revise the air pollution control train, or the cost to procure and install heat exchangers and/or
boilers to reduced the exhaust gas temperature prior to the activated carbon injection point below
350 deg-F. The commenter stated that the total costs for a carbon injection system, carbon
contact chamber and baghouse, or the carbon adsorber as contained in the docket for the
proposed SSI rule (Docket ID # 2009-0059-0015), do not address these additional costs.
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Another commenter (117.1) expressed concerns regarding the design and installation
costs of a mercury removal system. The commenter stated that not only will they need to hire an
engineer to design a system, but they will need to do it at the same time that other agencies in the
country are looking to the same few incinerator consultants. The commenter (117.1) asserted that
this cost will be burdensome to the facility, as it does not have the same financial resources that
other larger jurisdictions may have.
Response: We have reviewed the commenters' concerns regarding Hg control
technologies and agree that applying carbon injection to existing scrubbers has not been
demonstrated to be effective at removing Hg. Please refer to the memorandum "Revised
Analysis of Beyond the Maximum Achievable Control Technology (MACT) Floor Controls for
Existing SSI Units" (EPA-HQ-OAR-2009-0559). For other combustion sources, carbon injection
in combination with a FF has proven to be highly effective in removing Hg. However, we also
agree that for high moisture flue gas streams, such as emitted from SSI units, the use of FFs is
problematic due to plugging/fouling. In order to use carbon injection with a FF with high
moisture streams, a waste heat boiler, RTO, or afterburner is necessary to maintain a high
enough temperature to keep the stream above the dew point prior to sending the stream to the FF.
Beyond-the-floor cost analyses were revised based on data corrections received during
the comment period, and after re-evaluating the cost effectiveness and environmental impacts of
additional mercury control beyond the floor, EPA is not going beyond-the-floor for the final
mercury standards. EPA does not expect that units will need to install additional mercury control
to meet the final standards.
Comment: One commenter (97.1, 127.1) stated that carbon adsorption for mercury
control is a costly option. The commenter provided estimates for activated carbon adsorbers of
$3.5 - 4 million per incinerator, and a total capital cost in of $564 - $644 million for the 161 MH
incinerators evaluated in the beyond-the-floor analysis. The commenter (97.1, 127.1) stated that
the cost to expand existing incineration facilities, add new ductwork and controls, and
engineering related design and construction management costs could easily raise the cost of these
units. The commenter (97.1, 127.1) stated that there are no U.S. manufacturers of carbon
adsorbers and they would have to be imported from overseas. The commenter (97.1, 127.1) also
stated that carbon adsorption polishing must be placed after the particulate control device. The
commenter (97.1, 127.1) reiterates that the most common existing particulate control for MHIs
are wet scrubbers, which generate significant amounts of steam and moisture that are
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incompatible with carbon adsorption, and that the exhaust must be heated so that moisture does
not condense as it moves through the carbon adsorption system. The commenter (97.1, 127.1)
provides the capital costs for an exhaust heater and carbon adsorption system Edmonds,
Washington ($1,500,000) and an annualized cost per pound of over $100,000 per pound of
mercury removed. The commenter (97.1, 127.1) stated that due to these costs, EPA cannot
justify carbon adsorption as a beyond the floor mercury control.
Response: For the final rules, EPA has determined that is it not appropriate to go
beyond-the-floor for mercury control.
Comment: A commenter (132.1) who claimed experience using ACT noted EPA has
significantly underestimated the cost of the emissions controls that will be necessary to meet the
proposed standards. The commenter (126.1) stated that carbon in general requires low flue gas
moisture, which has been a challenge to control with a "wet" control system or with the relatively
high moisture content of sewage sludge flue gas in general. The commenter (126.1) stated that
they have replaced component parts (not the carbon itself) of the system once, with another
upcoming replacement projected in the coming months, both instances much sooner than the
vendor-stated equipment life, with an additional cost of approximately $400,000 including
contract labor. The commenter noted that the scheduled and unscheduled shutdowns have
averaged 60 days per component replacement episode, during which they landfilled biosolids.
The commenter stated that the carbon that is designed for Hg removal is also only available
through European sources and will have been replaced three times in little over 4 years for an
additional cost of $190,000. The commenter requested that these costs be considered when
projecting the future costs to regulated sources to comply with Hg standards at or beyond the
MACT floor.
Response: After evaluating the revised emissions dataset (see the memorandum "Post-
Proposal SSI Database Revisions and Data Gap Filling Methodology" (EPA-HQ-OAR-2009-
0559) for further details ) to determine a revised MACT floor mercury limit and reconsidering
the types of controls needed to go beyond-the-floor, it was determined that it would not be
appropriate to go beyond-the-floor for any of the pollutants based on cost, emission reductions,
and other non-air impacts. Please refer to the preamble to the final SSI rule for a more detailed
discussion.
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18.8 Additional NOX Controls
Comment: At least one commenter (75.1) stated that EPA's analysis incorrectly assumes
that existing units may meet the proposed NOX limits. The commenter (75.1) states that due to
local permitting stipulations and EPA's determination that add-on NOX controls are inappropriate
for SSI units, that the existing MH and FB units at the facility could not comply with the
proposed NOX limitations. Another commenter (80.1) asserted that SNCR or SCR would be
necessary to meet NOX standards; the commenter stated that add-on controls were necessary
because EPA has not accurately accounted for the inverse relationship of CO and NOX in its
MACT floor methodology. One commenter (129.1) stated that while the use of internal
afterburners may result in reduced carbon monoxide emissions, most if not all of the POTWs that
practice incineration will be required to install external afterburners to meet the potential MACT
Standards. The commenter (129.1) provided costs estimates for the procurement and installment
of an external afterburning system, along with all appurtenances, engineering services and
building space, in the range of $3 - 4 million per unit (not including the cost to renovate or
expand an existing facility). The commenter (129.1) also argued that the proposed rule requires
the burning of substantial quantities of fossil fuel, will result in a substantial increase in oxides of
nitrogen emissions and greenhouse gas emissions. At least three commenters (67.1, 105.1, 137.1)
stated that SNCR or SCR may be necessary to meet the proposed NOX standard even though
EPA has assumed that SNCR or SCR would not be necessary. The commenters (67.1, 105.1,
137.1) stated that the inverse relationship between CO and NOX has not been adequately taken
into account when setting the NOX standard.
At least two commenters (87.1, 112.1) also stated that there are no practical means for
controlling NOX emissions from their existing MHI units. The commenters (87.1, 112.1)
remarked that the NOX content of incinerator exhaust gas is influenced by nitrogen content of the
sludge being burned and the amount and type of auxiliary fuel utilized to control combustion.
The commenters calculated that approximately 80% of their current NOx is from combustion of
the sewage sludge and not from combustion of the auxiliary fuel. The commenters (87.1, 112.1)
concluded that burner modifications (low-NOx burners) for the incinerators would be unlikely to
bring the incinerator into compliance with the proposed NOX standard.
Response: Based on available emissions data, including additional data and data
corrections received during the comment period, EPA expects that the majority of SSI units will
be able to meet the final CO standards (3,800 ppmvd for MH units and 64 ppmvd for FB units)
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without having to install additional CO control. EPA acknowledges the inverse relationship of
NOX and CO emissions (in terms of the additional NOX emitted when using supplemental fuel for
the afterburner); however, EPA maintains that it is incumbent upon the SSI facility to determine
whether combustion conditions can be adjusted to meet both CO and NOx standards and, if not,
install NOX controls as necessary (e.g., SNCR systems, SCR systems, FGR, or lowNOx
burners). In the proposed rule, EPA conjectured reasons why SCR and SNCR were not used or
may not be able to be used at SSI units. While we are not aware of any SSI unit that currently
uses SNCR or SCR, we also do not know of technical reason why they could not be used. Given
the limited data available on SSI units with FGR, we could not definitely determine how
effective the technology was on SSI units. However, we also do not know of a technical reason
why they could not be used, if necessary, to meet NOX limits.
Comment: One commenter (145.1) rejected the determination in the proposed
regulations that the use of an afterburner or regenerative thermal oxidizer (RTO) could require as
much as 1,700 million cubic feet of natural gas a year to be burned and result in NOX and CO
emissions of 84 and 70 TPY, respectively. The commenter argues that although conventional
afterburners require enormous quantities of auxiliary fuel, RTO's require very little fuel. The
commenter stated that a recent upgrade for a couple of MH incinerators indicated that with the
installation of an RTO, the overall auxiliary fuel consumption for the entire incineration system
is expected to be reduced. The commenter also stated that, using CO concentration as a surrogate
for dioxin and furans, the installation of RTOs would also reduce these pollutants. In addition,
the commenter asserted that with the use of a combination of a wet ESP and RTO, flue gases will
be very low in particulate and organic matter. The commenter further stated that due to reduced
concentrations of pollutants in the flue gas from the RTO, the activated carbon system is
expected to last for a reasonable period of time. The commenter provided a total cost for the
engineering, equipment, installation, and testing of an RTO at about $4,500,000.
Response: EPA's estimate of 1,700 million cubic feet of natural gas required per year
applies to the proposed beyond-the-floor option of adding an afterburner to all MH units not
already having an afterburner or RTO. This estimate was based on the natural gas usage of
conventional afterburner retrofits, not RTO systems. We did not include cost estimates for RTOs
given space considerations and higher capital costs when compared to afterburner retrofits. The
annualized cost for RTO's was estimated to be four to six times the annualized cost of an
afterburner.
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Comment: One commenter (145.1) provided flue gas recirculation as an option for the
reduction of NOX emissions. The commenter stated that, when properly operated, flue gas
recirculation may significantly reduce NOX emissions from MH incinerators. The commenter
cited stack emission tests conducted at New Haven, CT indicating that with flue gas recirculation
installed, the NOX emission rate could be reduced to about 50 ppmvd @ 7% oxygen or about 2 Ib
NOX per ton dry sludge incinerated.
Response: EPA thanks the commenter for their feedback and agrees that flue gas
recirculation could be a viable option for the reduction of NOX emissions. Given the limited data
available on SSI units with FGR, we could not definitely determine how effective the technology
was on SSI units. However, we also do not know of a technical reason why they could not be
used, if necessary, to meet NOX limits.
Comment: One commenter (129.1) provided cost estimates for the addition of either urea
or ammonia to the exhaust gases leaving the incinerator, in order to reduce oxides of nitrogen
emissions; the cost to design, procure and install a urea injection system were estimated to be
$1.5 - $2 million per incinerator. The commenter stated that use of urea and ammonia results in
the conversion of the oxides of nitrogen to nitrous oxide (N2O), a greenhouse gas.
Response: EPA thanks the commenter for their input. We would need additional
information regarding cost and performance to fully evaluate these other technologies.
18.9 Additional Heavy Metal Controls
Comment: One commenter (129.1) stated that an advanced scrubbing system might be
required to reduce particulate matter and some of the particulate based cadmium, lead, and
mercury. The commenter provided a total cost estimate of $1.25 - $1.75 million/unit (2009$) for
the delivery, installment, instrumentation, controls, electrical modifications, and engineering
services for a Venturi Pack scrubbing system. The commenter provided projected costs for a wet
electrostatic precipitator (WESP) averaging $2.5 - $3 million per wet ESP (2009 $). The
commenter added that for their new fluidized bed incineration project, approximately 15 feet
would have to be added onto the new facility to house the wet ESPs and associated equipment.
Response: EPA has re-evaluated the control options for particulate matter and metals and
agrees with commenters that, for SSI units, venturi scrubbers and WESP systems would be more
effective control options than fabric filters. WESP costs have been incorporated into EPA's
revised cost estimates for units already having venturi scrubbers but still expected to need
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additional control. The capital costs ranged from $2.3 to $2.8 million (2008$), which is in
keeping with the commenter's estimate. Please see the memorandum "Revised Cost and
Emission Reduction of the MACT Floor Level of Control" (EPA-HQ-OAR-2009-0559) for
further details. For units requiring further control that do not already have venturi scrubbers,
costs for venturi scrubbers were estimated and incorporated into the total compliance cost.
18.10 Additional SO2 Controls
Comment: One commenter (129.1) also provided cost estimates for the reduction of
sulfur dioxide and oxides of nitrogen emissions. The commenter provided costs for the addition
of sodium hydroxide to the wet scrubbing systems; the costs to design, procure and install a
sodium hydroxide addition system were estimated to be $0.25 - $ 0.3 million per incinerator
(2009$).
Response: The cost algorithms used for EPA's analyses include the equipment and
materials necessary to operate packed bed scrubbers. EPA notes that we are not going beyond the
floor for these pollutants.
18.11 Unfair Impacts for Existing Fluidized Bed Incinerators
Comment: Some commenters (80.1, 137.1) stated that the proposed standards represent a
penalty for facilities that have replaced aging MHI with far more efficient and lower polluting
FBI. The commenter (80.1) stated that newer FBI units generally have better emissions controls
than MHI units, therefore, the emissions test data for FBIs used by EPA to establish MACT
floors were generally significantly lower than those for MHIs. The commenters (80.1, 137.1)
stated that existing MHIs will likely meet the applicable, less stringent, standards with the
exception of mercury, which can be met by retrofitting activated carbon adsorption. The
commenters (80.1, 137.1) stated that the more stringent standards for existing FBIs may require
modifications to the existing wet scrubbers and/or additional wet scrubbers (e.g., packed towers)
to meet HC1 and 862 limits, and addition of WESPs where venturi scrubbers are currently used
to meet Cd, Pb and PM limits, in addition to carbon adsorption systems to meet proposed Hg
standards.
Response: EPA acknowledges that FB units have more stringent limits to meet, but this
is because, as the commenter notes, they are generally more efficient and lower polluting. The
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MACT floor limits are intended to represent the best performing units. Please refer to Section V,
Part C of the preamble for EPA's response to MACT floor methodology concerns.
18.12 Regulation Forces Incinerator Closures
Comment: Several commenters (87.1, 74.1, 68.1, 58, 69.1, 61.1, 78.1, 63.1, 94.1, 70.1,
67.1, 107.1, 106.1, 102.1, 116.1, 114.1, 121.1, 120.1, 115.1, 138, 73.1, 89.1, 93.1, 101.1, 109.1,
105.1, 117.1, 118.1, 126.1, 136.1) stated that EPA's proposed new source performance standards
could effectively eliminate the construction of new sewage sludge incinerators (SSIs), and the
standards for existing SSIs could force many communities to abandon incineration as early as
2016. One commenter (72.1) stated that due to bond financing, their facilities would need to
abandon incineration by 2014. At least one commenter (81.1) stated that due to the cost, the
proposed standards would eliminate planned incinerator improvements and may result in the de-
commissioning of units currently in operation. These commenters (87.1, 74.1, 68.1, 58, 69.1,
61.1, 78.1, 63.1, 94.1, 70.1, 67.1, 107.1, 106.1, 120.1116.1, 114.1, 120.1, 115.1, 73.1, 93.1,
101.1, 109.1, 105.1, 117.1, 118.1, 126.1, 136.1) stated that loss of incineration as a viable
management option will have major economic consequences (72.1, 81.1, 103.1, 89.1), eliminate
a major green energy source (94.1,68.1,69.1, 107.1, 106.1, 103.1, 102.1, 116.1, 114.1, 120.1,
115.1), and result in a transfer of emissions from SSIs, which are already controlled under the
Clean Water Act Part 503 regulations, to the tens of thousands of trucks that will be needed to
haul the Nation's sludge to landfills across the country (72.1, 81.1, 94.1, 68.1, 70.1, 70.1, 67.1,
69.1, 107.1, 106.1, 103.1, 102.1, 116.1, 114.1, 120.1, 115.1). Another commenter (73.1) stated
that the trucks are notorious major sources of NOx, VOC, and green house gas emissions,
including fugitive methane.
At least one commenter (126.1) stated that the proposed standards would severely restrict
a POTW's ability to modify existing multiple hearth incinerators, including modifications to
improve combustion efficiency or provide energy recovery for electricity generation and
virtually eliminate all new MHF SSI construction. Another commenter (49.1) argued that EPA
should not force closure of the 160+ MH incinerators that were built before 1980 and currently
use outdated control equipment. The commenter (49.1) stated that, for existing MH units,
upgrading the scrubber and dewatering devices could result in better MH performance, while
being able to keep the buildings, HVAC, piping and MH infrastructure. The commenter (49.1)
asserted that it is unfair that the citizens of communities whom have invested hundreds of
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millions of dollars in capital be forced to abandon major MH incinerator infrastructure without
being given the knowledge and cost about appropriate dewatering and scrubber equipment
upgrades. One commenter (107.1) stated that the proposed regulations will force small entities to
treat sewage sludge to meet the land application requirements of 40 CFR Part 503; the
commenter noted that this will require a capital investment of several million dollars.
Several commenters (97.1, 127.1, 110.1, 118.1, 121.1, 128.1, 90.1) stated that the
promulgation of the proposed emission limits for SSIs will significantly discourage incineration
as a sludge management option. One commenter (118.1) specifically stated that due to increased
costs for incineration for upgraded scrubber equipment, new CEMS equipment, increased stack
test frequency and increased record keeping requirements, they would have to reconsider using
incineration as a sludge disposal option. Commenters (128.1, 90.1) stated that EPA must
consider that POTWs have limited options to manage their sewage sludge (i.e., incineration, land
application, composting, energy production, and landfilling) and must develop a comprehensive
view of how sewage sludge waste should be handled throughout the United States. Some
commenters (85.1, 97.1, 127.1, 110.1) noted that there are state and local restrictions that
prevent the landfilling of biosolids, which further restricts options for POTWs. Another
commenter (97.1, 127.1) stated that EPA should consider incineration as a local option for
residuals management and as an emerging renewable energy source for generating electricity and
steam.
Response: At proposal for the MH new source subcategory, we considered the best-
performing FB incinerator to be the best-performing similar source because we were not aware
of any new MH sources that have been constructed in the last 20 years, and information provided
by the industry indicates that future units that will be constructed are likely to be FB incinerators.
We have re-evaluated our decision. Although few MH units have been constructed over the last
20 years, there is no technical reason that would preclude a source from constructing a MH unit.
Therefore, we are setting separate standards for MH units at new sources in order to not limit
potential options POTW can use to dispose of waste. We still believe that new SSI units
constructed will be FB units because of the many advantageous of FB units over MH units.
The definition of "modification" is from Section 129 of the CAA. The addition of
pollution controls in order to meet limits is not considered a modification. Our responses to
modification concerns are addressed in section 3.0 of this document.
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EPA notes that the emission limits have been revised since proposal. Limits are based on
data collected, following established procedures that incorporate variability.
EPA would like to clarify that at proposal, we were not requiring facilities to landfill;
landfilling was merely considered as a potential alternative disposal option for facilities unable to
meet the limits without installing additional pollutant control. In our revised cost analyses, we re-
evaluated the landfilling option and determined that it was not appropriate or cost effective for
most facilities.
Comment: One commenter (48.1) stated that a seven year period from the start of a
Request for Proposals to being able to abandon the use of their multiple hearth incinerators
would be realistic. The commenter (48.1) is concerned about an additional 30 million dollar
solids handing system that would be required for them to be compliant with the schedule of the
current rulemaking in addition to their recent mandated treatment-plant expansion (to be
completed by 2014) to address secondary treatment requirements which is costing their
ratepayers over 40 million dollars. Similarly, another commenter (138) is concerned about the
additional costs that would be passed on to their customers should they become subject to the
proposed rule (by meeting the definition of modification) by making wet weather improvements
to their incinerators.
Response: EPA would like to clarify that at proposal, we were not requiring facilities to
landfill; landfilling was merely considered as a potential alternative disposal option for facilities
unable to meet the limits without installing additional pollutant control. In our revised cost
analyses, we re-evaluated the landfilling option and determined that it was not appropriate or
cost effective for most facilities.
At proposal for the MH new source subcategory, we considered the best-performing FB
incinerator to be the best-performing similar source because we were not aware of any new MH
sources that have been constructed in the last 20 years, and information provided by the industry
indicates that future units that will be constructed are likely to be FB incinerators.
We have re-evaluated our decision. Although few MH units have been constructed over the last
20 years, there is no technical reason that would preclude a source from constructing a MH unit.
Therefore, we are setting separate standards for MH units at new sources in order to not limit
potential options POTW can use to dispose of waste. We still believe that new SSI units
constructed will be FB units because of the many advantageous of FB units over MH units. The
definition of "modification" is from Section 129 of the CAA. The addition of pollution controls
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in order to meet limits is not considered a modification. EPA notes that the emission limits have
been revised since proposal. Limits are based on data collected, following established procedures
that incorporate variability.
18.13 Space Constraints
Comment: Several commenters (80.1, 69.1, 121.1, 73.1,96.1, 129.1, 134.1) provided
that their facility is already space constrained; reconfiguring or adding additional controls in the
limited space would either be very costly or cost prohibitive. One commenter (111.1) specifically
stated that there is no space available to install additional emission control systems, providing
that local ordinances include building height restrictions. One commenter (134.1) stated that an
afterburner would be required to burn out the unburned carbon and soot that exit a typical MH
unit. The commenter (134.1) asserted that the space required for the afterburner, waste heat
boiler, and fabric filter would be approximately three times the space of the existing MH unit,
stating that the concept of adding afterburners, waste heat boilers, and fabric filters to existing
MHs is impractical, and in most cases, physically impossible. Another commenter (69.1) stated
that site facilities are limited in grounds available for expansion due to geographical constraints -
rivers, state borders, and railroads. Specifically, one commenter (126.1) asserted that their
original incinerators were built to take up a minimal footprint; thus, the space within and around
the incinerator building are already severely constrained. The commenter (126.1) estimates that
the modifications required for additional controls would therefore incur significant cost. The
commenter (126.1) stated that a new air pollution control equipment train (including WESP,
RTO with FD fan, carbon polisher and free standing exhaust stack) must be located
approximately 350 feet away from the MHF SSIs due to existing space limitations and site
constraints, and a second active carbon polisher (for mercury removal from the exhaust gas
exiting the existing RTO) must be located approximately 50 feet away from the existing
equipment. The commenter (126.1) provided a total estimated current capital cost for the
modifications to the existing MHF SSIs of $9,600,000.
At least one commenter contended (65.1) that further modifications are estimated to
incur significant cost due to the restriction on available space. One commenter (134.1) stated that
due to the lack of adequate space, the proposed regulation could lead to the closure of several
SSI facilities.
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Response: Based on our revised analyses, we believe that many SSI's will be able to
comply with the final rules without the addition of multiple control technologies. Additionally,
the control cost algorithms used in these analyses include retrofit factors that take into account
space considerations.
18.14 Additional Cost Concerns
Comment: At least one commenter (76.1) requested justification for increased
monitoring costs. The commenter (76.1) stated that monitoring costs must consider new
parametric monitoring, monitoring carbon flow rate and carrier gas flow rate for carbon
injection, monitoring of scrubber pH and scrubber water flow rate for use of a wet scrubber to
remove HCI, and particulate monitors for ash handling. One commenter (89.1) requested that
EPA calculate the increased economic and resource burden to facilities regarding the
recordkeeping and reporting requirements under the Proposed Standards. Another commenter
(93.1) identified additional costs in permitting, testing, training and administrative efforts in
being regulated under the proposed rule at $130,000 per year.
Response: EPA has revised the final limits, and after revising the emissions data set and
associated default parameters based on data corrections submitted during the comment period,
EPA has revised its cost estimates for MACT and beyond-the-floor control options. EPA is
required to incorporate continuous compliance requirements into its MACT standards, such as
CEMS or continuous parametric monitoring. The revised costs include the incorporation of
relevant monitoring requirements for the final rule. Please refer to the memoranda "Revised Cost
and Emission Reduction of the MACT Floor Level of Control" and "Revised Analysis of
Beyond the Maximum Achievable Control Technology (MACT) Floor Controls for Existing SSI
Units" ( EPA-HQ-OAR-2009-0559) for details). Consequently, emission reduction estimates and
cost-effectiveness were also re-evaluated for the MACT floor and beyond-the-floor options.
Additionally, EPA has re-evaluated the applicable control options for each pollutant. Based on
these results, EPA has decided not to go beyond-the-floor for any of the pollutants. EPA has also
prepared a burden estimate for affected sources of the recordkeeping and reporting requirements.
The results of the burden estimate are summarized in the preamble to the final SSI rules and in
the supporting statement to EPA's OMB-83 form.
Comment: One commenter (76.1) contended that there will be significant impact on
small entities including new equipment costs, increased O&M costs, and increased labor costs.
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Furthermore, the commenter (76.1) asserted that EPA's determination that using CEMS is more
cost effective than an annual source test is not true given the full time equivalent personnel
necessary to keep CEMS calibrated and online. The commenter (76.1) stated that the decision to
use all CEMS or a combination of CEMS and annual source testing is site specific, and requested
that flexibility be built into the regulation for appropriate site specific monitoring as determined
by the POTW.
Response: EPA has revised the final limits, and after revising the emissions data set and
associated default parameters based on data corrections submitted during the comment period,
EPA has revised its cost estimates for MACT and beyond-the-floor control options. These
revisions include the incorporation of relevant monitoring requirements for the final rule. Please
refer to the memoranda "Revised Cost and Emission Reduction of the MACT Floor Level of
Control" and "Revised Analysis of Beyond the Maximum Achievable Control Technology
(MACT) Floor Controls for Existing SSI Units" ( EPA-HQ-OAR-2009-0559) for details).
Consequently, emission reduction estimates and cost-effectiveness were also re-evaluated for the
MACT floor and beyond-the-floor options. Additionally, EPA has re-evaluated the applicable
control options for each pollutant. Based on these results, EPA has decided not to go beyond-the-
floor for any of the pollutants.
EPA would also like to clarify that CEMS are optional except for CO CEMS for new
sources. Our small entity analysis is also discussed in the preamble the final SSI rules.
18.15 Greenhouse Gases and Fossil Fuel Use Would Increase
Comment: A commenter (121.1) argued that GHG emissions would increase since the
beyond-the-floor limits are cost prohibitive. The commenter stated that their facility captures
waste heat from the incineration process and uses it in the wastewater treatment process, and if
incineration is stopped that energy requirement will be supplied by the electric utility. The
commenter indicated that incineration has been shown by Metropolitan St. Louis Sewer District
as the last GHG producing method of disposal compared to landfill disposal.
One commenter (97.1, 127.1) stated that EPA is required to consider energy impacts as
part of its beyond the floor analysis. The commenter (97.1, 127.1) asserted that EPA should
consider the projects currently underway that generate electricity from the heat produced by
SSIs, noting that electricity generated by the SSI reduces the POTW demand for electricity from
the grid. The commenter stated that reduced demand for electricity from the grid means less coal
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combustion and less of the emissions that coal would have generated, including less mercury
emissions and less reliance on fossil fuels. The commenter was of the opinion that the proposed
beyond the floor controls could discourage this advanced energy option, resulting in more coal
combustion and more mercury emissions.
Response: Beyond-the-floor cost analyses were revised based on data corrections
received during the comment period. After re-evaluating the cost effectiveness and
environmental impacts of additional control beyond the floor, EPA is not going beyond-the-floor
for the final standards. Energy generated by SSI units was not incorporated into the beyond-the-
floor analysis because we did not have energy generation data available; however, estimated
energy usage required for beyond-the-floor controls was considered. Please refer to the
memorandum "Revised Analysis of Beyond the Maximum Achievable Control Technology
(MACT) Floor Controls for Existing SSI Units" (EPA-HQ-OAR-2009-0559) for further details.
18.16 Environmental Benefits of Incineration
Comment: Several commenters (72.1, 58, 62.1, 63.1, 67.1, 68.1, 69.1, 70.1, 74.1, 78.1,
81.1, 102.1, 103.1, 106.1, 107.1, 114.1, 115.1, 116.1, 120.1, 61.1, 73.1) stated thatEPAmust
develop environmentally and economically sound standards by considering energy recovery
options. Specifically, these commenters (72.1, 58, 62.1, 63.1, 67.1, 68.1, 69.1, 70.1, 74.1, 78.1,
81.1, 102.1, 103.1, 106.1, 107.1, 114.1, 115.1, 116.1, 120.1, 61.1, 111.1, 121.1, 101.1, 109.1,
105.1, 112.1, 117.1, 118.1) stated that EPA has underestimated emission control costs and
overestimated the baseline emissions from existing SSI. Many of these commenters stated that
based on these costs, the proposed standards, if implemented, would result in many wastewater
utilities sending sludge, an energy-rich secondary material, for disposal in a landfill. At least one
of these commenters (58) stated that the proposed regulation would limit municipalities sludge
management options and greatly increase sludge disposal costs. Commenters (58, 62.1, 63.1,
67.1, 68.1, 69.1, 70.1, 74.1, 78.1, 81.1, 102.1, 103.1, 106.1, 107.1, 114.1, 115.1, 116.1, 120.1,
61.1,75.1, 101.1,93.1, 105.1, 109.1, 112.1, 117.1, 118.1) were of the opinion that the proposed
standards should encourage upgrades to newer, cleaner incinerators with energy recovery that
would offset the energy needs for treating wastewater. The commenters (58, 62.1, 63.1, 67.1,
68.1, 69.1, 70.1, 74.1, 78.1, 81.1, 102.1, 103.1, 106.1, 107.1, 114.1, 115.1, 116.1, 120.1, 61.1,
74.1,72.1,90.1, 113.1,94.1,73.1,89.1, 109.1, 105.1) stated that, given that increasing economic
challenges and expanding regulation, EPA must ensure its policies are environmentally and
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economically sound, and that those policies should allow municipalities to engage in practices
that can maximize their resources and limit their carbon footprint.
One commenter (129.1) stated that greenhouse gas emissions from sewage sludge
incinerators can be substantially lower than the greenhouse gas emissions associated with other
sewage sludge management options. Other commenters (108.1, 134.1) stated that EPA should
reconsider the use of biosolids as a renewable fuel source in developing the proposed standards.
One commenter (134.1) requested that EPA clarify the impact of the rule on technologies that
focus on reuse of wastewater solids for energy production and recovery, such as gasification,
pyrolysis, boilers, and fluid bed combustors.
Response: EPA has revised the final limits, and after revising the emissions data set and
associated default parameters based on data corrections submitted during the comment period,
EPA has revised its cost estimates for MACT and beyond-the-floor control options. Please refer
to the memoranda "Revised Cost and Emission Reduction of the MACT Floor Level of Control"
and "Revised Analysis of Beyond the Maximum Achievable Control Technology (MACT) Floor
Controls for Existing SSI Units" ( EPA-HQ-OAR-2009-0559) for details). Consequently,
emission reduction estimates and cost-effectiveness were also re-evaluated for the MACT floor
and beyond-the-floor options. Additionally, EPA has re-evaluated the applicable control options
for each pollutant. Based on these results, EPA has decided not to go beyond-the-floor for any of
the pollutants. EPA would like to clarify that at proposal, we were not requiring facilities to
landfill; landfilling was merely considered as a potential alternative disposal option for facilities
unable to meet the limits without installing additional pollutant control. In our revised cost
analyses, we re-evaluated the landfilling option and determined that it was not appropriate or
cost effective for most facilities. The selection of a management option for sewage sludge is
often a local decision that is based on environmental protection concerns, community needs,
geographic constraints, and economic conditions. Given a full evaluation of these factors, for
some sources, landfilling or land treatment may be a better management option than incineration.
EPA has clarified in the final rule that sewage sludge that is not burned in an SSI unit
located at a wastewater treatment facility designed to treat domestic sewage sludge is subject to
other section 129 standards, such as the CISWI standards (40 CFR part 60, subparts CCCC and
DDDD of this part), the OSWI standards (40 CFR part 60, subparts EEEE and FFFF), the MWC
standards (40 CFR part 60, subparts Ea, Eb, Cb,AAAA, and BBBB of this part) or the Hazardous
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Waste Combustor rule (40 CFR part 63 subpart EEE). Facilities that are unsure if their process is
a combustion process, are welcome to submit a formal applicability determination to the Agency.
18.17 Energy Recovery Would be Reduced
Comment: One commenter (108.1) stated that the proposed ruling effectively bans
recovery of the energy resources inherent in biosolids and appears to promote landfilling.
Commenters (48.1) claimed that the Proposed Regulation will end their efforts towards energy
recovery from their incineration and solids handling practice. One commenter (108.1)
specifically claimed that the proposed standards will eliminate an existing biomass incinerator as
an option to generate electricity from biosolids. Another commenter (108.1) stated that in
addition to the potential elimination of energy recovery options (including using gasification to
produce a syngas that can be combusted to produce energy in a generator, steam reformation to
produce a hydrogen gas that can be used as a liquid transportation fuel, and conversion of
biosolids to a solid fuel that can be used as an alternative feedstock at a biomass to energy
facility), there is a negative perception created by the proposed rule's suggested alternative of
landfilling.
At least one commenter (75.1) argued that incineration is a necessary part of managing
sludge at their facility, especially during the winter and early spring. The commenter (75.1)
stated that their energy recovery (incineration) system offsets a significant portion of the
electricity and natural gas consumption by utilizing the steam produced from incineration to heat
the majority of all plant facilities and to satisfy domestic and process hot water needs. The
commenter noted that during winter and early spring, approximately 90% of biosolids are hauled
to the landfill or incinerated, stating that there is no storage capacity at the facility. One
commenter (97.1, 127.1) stated that incineration provides them with an option for energy
recovery, which will offset approximately 25 percent of the current demand for electricity each
year. The commenter (97.1, 127.1) concluded that this demand reduction reduces the mercury
emissions and other air contaminants associated with utility coal combustion. The commenter
(97.1, 127.1) also provided that many states, such as Ohio and California, recognize the
generation of electricity from sewage sludge as eligible for renewable energy credit, which
provides additional economic incentives to invest in the electric-generating equipment for SSIs.
Response: EPA has revised the final limits, and after revising the emissions data set and
associated default parameters based on data corrections submitted during the comment period,
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EPA has revised its cost estimates for MACT and beyond-the-floor control options. Please refer
to the memoranda "Revised Cost and Emission Reduction of the MACT Floor Level of Control"
and "Revised Analysis of Beyond the Maximum Achievable Control Technology (MACT) Floor
Controls for Existing SSI Units" (EPA-HQ-OAR-2009-0559) for details). Consequently,
emission reduction estimates and cost-effectiveness were also re-evaluated for the MACT floor
and beyond-the-floor options. Additionally, EPA has re-evaluated the applicable control options
for each pollutant. Based on these results, EPA has decided not to go beyond-the-floor for any of
the pollutants.
EPA would like to clarify that at proposal, we were not requiring or even encouraging
facilities to landfill; landfilling was merely considered as a potential alternative disposal option
for facilities unable to meet the limits without installing additional pollutant control. In our
revised cost analyses, we re-evaluated the landfilling option and determined that it was not
appropriate or cost effective for most facilities. Emission limits have been revised since proposal,
and this may alleviate some of the commenters' concerns.
18.18 Other
Comment: One commenter (48.1) questioned the number of facilities (112) presented on
the Fact Sheet compared to the earlier value of 196 facilities.
Response: Based on additional data received during the comment period, EPA has
revised its inventory of SSI facilities and units. The revised inventory comprises a total of 204
units (60 FB and 144 MH) at 110 facilities. The 196 value the commenter notes is likely an
outdated unit count, rather than a facility count. Please refer to the memorandum "Post-Proposal
SSI Database Revisions and Data Gap Filling Methodology" (EPA-HQ-OAR-2009-0559) for
further details on the unit inventory revisions.
Comment: One commenter (96.1) requested that the EPA not rush to finalize the rules;
the commenter stated that more time is needed to understand the implications of setting mercury
limits below the MACT limits, utilities alternates, the true costs for utilities and the time allowed
for compliance. The commenter (96.1) stated that failing to do so will result in higher costs and
unintended social and environmental impacts.
Response: EPA has taken the time to revise the final limits, and after revising the
emissions data set and associated default parameters based on data corrections submitted during
the comment period, EPA has revised its cost estimates for MACT and beyond-the-floor control
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options. Consequently, emission reduction estimates and cost-effectiveness were also re-
evaluated for the MACT floor and beyond-the-floor options. Additionally, EPA has re-evaluated
the applicable control options for each pollutant. Based on these results, EPA has decided not to
go beyond-the-floor for any of the pollutants. Please refer to the memoranda "Revised Cost and
Emission Reduction of the MACT Floor Level of Control" and "Revised Analysis of Beyond the
Maximum Achievable Control Technology (MACT) Floor Controls for Existing SSI Units"
(EPA-HQ-OAR-2009-0559) for details.
Comment: Several commenters (129.1, 102.1, 116.1, 138) stated that the projected
benefits would be lower than estimated. One commenter (84.1, 119.1) stated that while the
proposed rule would have significant reductions in annual mercury and dioxin emissions,
reductions in other emissions are less substantial. The commenter (84.1, 119.1) stated that
proposed rule will reduce emissions of lead, cadmium, and particulate matter by less than half
and would have virtually no effect on NOx emissions. Some commenters (129.1, 138)
specifically expressed concern that the projected health related cost savings estimated by EPA
were "substantially overestimated". Several commenters (61.1, 88.1, 90.1, 132.1, 136.1)
suggested that EPA should consider energy-recovery and/or renewable energy generation as an
option. One commenter (129.1) stated that the proposed cost-benefit analysis does not adequately
address the concerns raised during the Federalism conference call.
Response: EPA has revised the final limits, and after revising the emissions data set and
associated default parameters based on data corrections submitted during the comment period,
EPA has revised its impacts analyses for MACT and beyond-the-floor control options. We have
revised our costs and impacts of the landfill alternative based on comments received on the
proposal and corrections made to the analysis. Based on the revised impacts, it is unlikely that
many sources will find landfilling an appropriate alternative. Please refer to Section V, Part F of
the preamble for further information regarding the revised health/benefits analysis.
Comment: Two commenters (122, 123) stated that they were extremely concerned that
numerous provisions of the proposed Guidelines result in over regulation and unachievable
control of emissions. Another commenter (108.1) suggested that the proposed sewage sludge
incineration standards are the most restrictive in the world and stated that the limits will not be
achievable or supported by the equipment manufacturers. The same commenter (108.1) said that
the implications to the wastewater industry will be significant and will likely result in greater
environmental impacts and additional financial burden for the public.
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Response: EPA has revised the limits for existing and new sources and believes, given
the available emissions data, that the limits are achievable with the installation of appropriate
controls where needed.
Comment: One commenter (138) points out that the EPA press release dated October
1st, 2010 states that EPA estimated the proposed ruling would yield health benefits ranging from
130,000,000 to 320,000,000 in 2015. Commenters (76.1, 138) are concerned about the pathway
claimed in the press release (that the mercury emitted from the incinerators deposits in the water
where it changes into methyl-mercury which can then bioaccumulate in fish - and when these
fish are consumed by humans, particularly children or pregnant women, there is a risk of damage
to the developing brain). The commenters (76.1 138) want to know whether a health risk
assessment had been done to demonstrate this pathway and calculate the actual health risks; and
if so, where is this information published such that the public can review and comment on it. One
commenter (76.1) stated that the Agency should provide this published information to the
scientific and regulated community for review and use the proper costs to calculate the social
benefit.
Response: The health benefits assessment is available in the Regulatory Impact Analysis
developed for the proposed rule, which is available at http://www.epa.gov/ttn/ecas/ria.html. Due
to time limitations under the court-ordered schedule, EPA was unable to analyze the mercury
deposition, methylation, bioaccumulation in fish tissue, and human consumption of mercury-
contaminated fish that would be needed in order to estimates the human health benefits from
reducing mercury emissions. However, this analysis did estimate the monetized health benefits
from reducing fine particles and particle precursors such as NOx and SO2. Although the
monetized benefits are likely an underestimate of the total benefits, the extent of the
underestimate is unclear.
Comment: Some commenters (88.1, 129.1) stated that EPA did not adequately address
additional impacts, including the potential loss of human life and injuries associated with the
significant increases in transportation to and from the disposal of the sewage sludge at municipal
solid waste landfills or land application sites, increased air pollution and noise, additional
criteria, toxic, and greenhouse gas pollutant emissions from increased trucking.
Response: We have revised our costs and impacts of the landfill alternative based on
comments received on the proposal and corrections made to the analysis. Table 14 of the
preamble summarizes the revised costs and impacts of this alternative if small entities choose to
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landfill rather than incinerate sewage sludge. A detailed discussion of the landfilling alternative
analysis is provided in the memorandum "Revised Cost and Emission Reduction of the MACT
Floor Level of Control" in the SSI docket (EPA-HQ-OAR-2009-0559).
Based on the revised impacts, it is unlikely that many sources will find landfilling an
appropriate alternative. The selection of a management option for sewage sludge is often a local
decision that is based on environmental protection concerns, community needs, geographic
constraints, and economic conditions. Given a full evaluation of these factors, for some sources,
landfilling or land treatment may be a better management option than incineration.
Comment: One commenter (82.1) stated EPA should commit to providing guidance and
technical assistance to POTWs in implementing the proposed rule. The commenter (82.1) is
concerned for smaller facilities that are already implementing a number of requirements under
the Clean Water Act with limited staff and resources. The commenter (82.1) stated that
implementing requirements of the Clean Air Act will be unfamiliar territory and can be done
more effectively with assistance from EPA.
Response: EPA plans to provide guidance after the rule is finalized.
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19.0 IMPACTS ANALYSIS -SMALL BUSINESS
Comment: One commenter (51.14) wanted to know the basis for EPA's determination
that the Proposed Standards will not have a "significant economic impact" on a substantial
number of small entities.
Response: Small entities include small businesses, small organizations, and small
governmental jurisdictions. For purposes of assessing the impacts of this action on small entities,
a small entity is defined as follows: 1) a small business as defined by the SBA regulations at 13
CFR 121.201; 2) a small governmental jurisdiction that is a government of a city, county, town,
school district, or special district with a population of less than 50,000; or 3) a small organization
that is any not-for-profit enterprise that is independently-owned and operated and is not
dominant in its field. In the proposal, EPA certified that there would not be a significant
economic impact on a substantial number of small entities. The economic analysis conducted at
proposal identified 18 small entities, none of which had cost-revenue-ratios greater than one
percent. The cost analysis for the final standards showed a significant decrease (35 to 98 percent)
in all costs for 11 of the 18 small entities and the same decrease in annualized costs for the
remaining small entities while their estimated capital costs stayed at the same level as those
estimated at proposal. Therefore, given the decrease in costs from the proposed rule, we consider
the final rule to have no significant impact on a substantial number of small entities. Please refer
to the preamble to the final rule and the RIA for a more detailed description of the small entity
analysis.
The cost-revenue-ratios were again estimated using the costs for the final rule and the
same revenue estimates used in the proposal screening analysis. The revenue estimates were
obtained using census average per capita revenue numbers ($1,696 for entities with populations
between 10 thousand and 25 thousand and $1,677 for entities with populations between 25
thousand and 50 thousand) The resulting cost-revenue-ratios ranged between 0.04% and 0.5.
Thus all cost-revenue-ratios were well below 1%.
Comment: The commenter (97.1, 127.1) is concerned about the small entity impacts
discussed in EPA's Option 3 of the Regulatory Impacts Analysis. In particular, the commenter
(97.1, 127.1) is concerned about the beyond the floor mercury controls as EPA identified that it
will significantly affect 16 of 18 small entities at greater than 1 percent of their cost-revenue
ratios and three of those at greater than 3 percent. The commenter (97.1, 127.1) stated that these
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levels of impact would require a more thorough consideration of small entity impacts based on
EPA's Final Guidance for EPA Rulewriters: Regulatory Flexibility Act as Amended by the
Small Business and Regulatory Enforcement Fairness Act (November 2006) (disallowing a
presumption of No SISNOSE at these levels of impact). The commenter (97.1, 127.1) stated that
only by assuming the cost-effective landfill alternative for small entities could the Administrator
presume No SISNOSE under this guidance and shortcut the administrative protections that the
RFA and Small Business Regulatory Fairness Act ("SBREFA") provide for small governments.
Response: EPA has revised the final limits, and after revising the emissions data set and
associated default parameters based on data corrections submitted during the comment period,
EPA has revised its cost estimates for MACT and beyond-the-floor control options.
Consequently, emission reduction estimates and cost-effectiveness were also re-evaluated for the
MACT floor and beyond-the-floor options. Additionally, EPA has re-evaluated the applicable
control options for each pollutant. Based on these results, EPA has decided not to go beyond-the-
floor for any of the pollutants. Please refer to the memoranda "Revised Cost and Emission
Reduction of the MACT Floor Level of Control" and "Revised Analysis of Beyond the
Maximum Achievable Control Technology (MACT) Floor Controls for Existing SSI Units"
(EPA-HQ-OAR-2009-0559) for details. The economic analysis conducted at proposal identified
18 small entities, none of which had cost-revenue-ratios greater than one percent. The cost
analysis for the final standards showed a significant decrease (35 to 98 percent) in all costs for 11
of the 18 small entities and the same decrease in annualized costs for the remaining small entities
while their estimated capital costs stayed at the same level as those estimated at proposal.
Therefore, given the decrease in costs from the proposed rule, we consider the final rule to have
no significant impact on a substantial number of small entities.
The cost-revenue-ratios were again estimated using the costs for the final rule and the
same revenue estimates used in the proposal screening analysis. The revenue estimates were
obtained using census average per capita revenue numbers ($1,696 for entities with populations
between 10 thousand and 25 thousand and $1,677 for entities with populations between 25
thousand and 50 thousand) The resulting cost-revenue-ratios ranged between 0.04% and 0.5.
Thus all cost-revenue-ratios were well below 1%.
Comment: One commenter (97.1, 127.1) urged EPA to abandon the landfill alternative
presumption that it used to shortcut small government relief under RFA and UMRA. Instead, the
commenter (97.1, 127.1) recommended that EPA consider the full cost of its proposed control
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technology on small entities and engage in the appropriate RFA/UMRA processes to evaluate
ways to mitigate the burden of this rule on these small entities. The commenter (97.1, 127.1)
stated that EPA's fundamental misconception about the nature of sewage sludge affects many
aspects of the Proposed Rule. The commenter (97.1, 127.1) said that it is confident that when
EPA corrects its cost analysis for small entities, the landfill alternative will not be cost-effective
for many if not all of the small entities. As an example, the commenter (97.1, 127.1) said that the
City of Edmonds, a small government entity located in Washington State, has reported that it has
no intention of trucking its sewage sludge to a landfill, the closest of which is 270 road miles
away. The commenter (97.1, 127.1) provided the following to support their argument:
- The commenter (97.1, 127.1) stated that EPA's cost analysis for the landfill
alternative is based on dry tons of sludge, which underestimates the amount of sludge
being sent to a landfill by a factor of three to five.
The commenter (97.1, 127.1) purported that the landfill alternative requires as many
as five times more truck loads, and argued that EPA overestimated the amount of
sludge a single truck can hold. The commenter (97.1, 127.1) stated that EPA
estimated that 34 tons of sewage sludge can be hauled in each truck, when in reality
only 15-20 tons can be hauled per truck based on the 80,000 pound total truck weight
limit for roadways in Ohio. The commenter (97.1, 127.1) indicated that this alone
doubles the cost that EPA assumed to be associated with trucking sewage sludge to
landfill.
The commenter (97.1, 127.1) argued that the landfill alternative requires five times
more landfill tipping fees, and five times as much on-site storage and loading
capacity.
The commenter (97.1, 127.1) argued that EPA assumed that onsite storage capacity
would require a cement pad with a railing, instead of the more costly tankage
necessary to contain sludge that is 70-80 percent water.
- The commenter (97.1, 127.1) argued that EPA failed to consider the cost and
limitations associated with landfills rejecting wet sludge due to capacity restrictions
and moisture limitations. The commenter (97.1, 127.1) stated that POTWs will have
to transport sludge farther in search of landfill capacity willing and able to take wet
sewage sludge.
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Response: We have revised our costs and impacts of the landfill alternative based on
comments received on the proposal and corrections made to the analysis. Table 14 of the
preamble summarizes the revised costs and impacts of this alternative if small entities choose to
landfill rather than incinerate sewage sludge. A detailed discussion of the landfilling alternative
analysis is provided in the memorandum "Revised Cost and Emission Reduction of the MACT
Floor Level of Control" in the SSI docket (EPA-HQ-OAR-2009-0559).
Based on the revised impacts, it is unlikely that many sources will find landfilling an
appropriate alternative. The selection of a management option for sewage sludge is often a local
decision that is based on environmental protection concerns, community needs, geographic
constraints, and economic conditions. Given a full evaluation of these factors, for some sources,
landfilling or land treatment may be a better management option than incineration.
Comment: One commenter (107.1) said that the City of Anacortes, a small government
entity located in Washington State, would be forced by this regulation to abandon the investment
of approximately 3.5 million dollars (1992) in structures and equipment to incinerate sewage
sludge; this will necessitate an investment in another method of sewage sludge disposal. The
commenter (107.1) stated that while land filling (the disposal option identified by EPA) may be
what Anacortes would initially rely upon, it is very unlikely that land filling would be a viable
long term disposal option; especially when the other SSIs that likely will be forced to make the
same decision are taken into account.
Response: EPA has revised the final limits, and after revising the emissions data set and
associated default parameters based on data corrections submitted during the comment period,
EPA has revised its cost estimates for MACT and beyond-the-floor control options.
Consequently, emission reduction estimates and cost-effectiveness were also re-evaluated for the
MACT floor and beyond-the-floor options. Additionally, EPA has re-evaluated the applicable
control options for each pollutant. Based on these results, EPA has decided not to go beyond-the-
floor for any of the pollutants. Please refer to the memoranda "Revised Cost and Emission
Reduction of the MACT Floor Level of Control" and "Revised Analysis of Beyond the
Maximum Achievable Control Technology (MACT) Floor Controls for Existing SSI Units"
(EPA-HQ-OAR-2009-0559) for details. Additionally, in our revised cost analyses, we re-
evaluated the landfilling option and determined that it would not appropriate or cost effective for
most facilities. EPA notes that the commenter's concern may be alleviated with the revised
emission limits.
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Comment: One commenter (58) stated that their facility is a "small entity" serving a
population of only 50,000. The commenter (58) is concerned that these proposed standards will
increase the cost of sewage sludge management for their residents and local industry.
Response: In the proposal, EPA certified that there would not be a significant economic
impact on a substantial number of small entities. The economic analysis conducted at proposal
identified 18 small entities, none of which had cost-revenue-ratios greater than one percent. The
cost analysis for the final standards showed a significant decrease (35 to 98 percent) in all costs
for 11 of the 18 small entities and the same decrease in annualized costs for the remaining small
entities while their estimated capital costs stayed at the same level as those estimated at proposal.
Therefore, given the decrease in costs from the proposed rule, we consider the final rule to have
no significant impact on a substantial number of small entities. The cost-revenue-ratios were
again estimated using the costs for the final rule and the same revenue estimates used in the
proposal screening analysis. The revenue estimates were obtained using census average per
capita revenue numbers ($1,696 for entities with populations between 10 thousand and 25
thousand and $1,677 for entities with populations between 25 thousand and 50 thousand) The
resulting cost-revenue-ratios ranged between 0.04% and 0.5. Thus all cost-revenue-ratios were
well below 1%.
Comment: One commenter (54.1, 60.1) disagreed with EPA's assumption described on
page 63288, Part 5 (B.5) that "all fine particles, regardless of their chemical composition, are
equally potent in causing premature mortality because there is no clear scientific evidence that
would support the development of differential effects estimates by particle type." The
commenter (54.1, 60.1) argued that PM mass should not be used as a surrogate for toxicity and
health effects because major components have been shown to be innocuous; and trace
components such as metals have been shown to be highly toxic. The commenter (54.1, 60.1)
stated that ambient air PM is a chemically non-specific pollutant; it is a collection of compounds,
aerosols, elements, etc, with widely varying potencies and sources.
Response: EPA's Integrated Science Assessment on Paniculate Matter (U.S. EPA, 2009),
which was reviewed by EPA's Clean Air Scientific Advisory Committee, concluded, "Overall,
the results indicate that many constituents of PM can be linked with differing health effects and
the evidence is not yet sufficient to allow differentiation of those constituents or sources that are
more closely related to specific health outcomes." In addition, the Health Effects Subcommittee
(HES) of EPA's Advisory Council on Clean Air Compliance Analysis concluded in 2009, "The
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HES agrees that the scientific evidence does not currently support this sort of assessment.
Additionally, the HES finds that differential assessment, even if feasible - would not lead to
substantially different results." Therefore, EPA assumes that all fine particles are equally potent
until the scientific literature clearly supports the development of a different methodology.
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20.0 IMPACTS ANALYSIS -LANDFILLING COSTS
20.1 Landfill Disposal Cost Basis
Comment: One commenter (90.1) stated that every POTW has a different way of
determining its cost to incinerate and the data collected through EPA's information collection
request did not include enough information to accurately determine unit costs. The commenter
(90.1) recommended that EPA conduct a more accurate analysis of the actual costs to incinerate
versus the cost to landfill needs. Other commenters (58, 61.1, 63.1, 65.1, 68.1, 69.1, 70.1, 71.1,
72.1, 73.1, 74.1, 75.1, 78.1, 83.1, 87.1, 89.1, 90.1, 93.1, 94.1, 96.1, 97.1, 127.1, 101.1, 102.1,
103.1, 105.1, 106.1, 107.1, 109.1, 110.1, 111.1, 112.1, 114.1, 115.1, 116.1, 118.1, 120.1, 121.1,
126.1, 128.1, 129.1, 132.1, 136.1, 138, 117.1) stated that EPA incorrectly developed costs on a
dry ton basis, instead of a wet ton basis, so the actual landfill disposal costs would be 3 to 10
times higher than EPA estimates (the stated amount/increase varied between commenters). One
commenter (97.1, 127.1) provided that EPA incorrectly presumed that the 100 dry ton/day SSI
would feed and combust 100 tons of sewage sludge per day (EPA presumes incorrectly that the
material fed into an SSI is dry and does not contain moisture). The commenter (97.1, 127.1)
asserted that sewage sludge is typically only 20-30 percent solids and 70-80 percent moisture;
and while SSIs are rated based on the number of dry tons per day they can combust, the sewage
sludge being fed into the incinerator is not dry. The commenter (97.1, 127.1) stated that when
sewage enters the POTW headworks it is over 99 percent water; and the POTW processes
increase the solids content to about 4 percent before it is "dewatered."
Numerous commenters (69.1,70.1,72.1,87.1,93.1,97.1, 127.1, 102.1, 112.1, 116.1,
118.1, 121.1,49.1, 111.1, 129.1, 117.1) performed their own cost analysis of land filling sludge
versus incineration. One commenter (69.1) said that landfill costs would be $108 per dry ton,
while incineration costs are $37 per dry ton. Another commenter (70.1) estimated a cost of $1.4
million per year (2009 dollars) for trucking and disposal of wet sludge cake at a landfill in their
geographic area based on actual costs incurred when landfill disposal was required for a short
period of time. Another commenter (87.1) stated that their cost for landfilling sewage sludge has
increased significantly in recent years up to the present rate of over $70 per wet ton (over $330
per dry ton) including hauling and disposal fees. Another commenter (93.1) stated that the cost
for land filling its sludge would be $57.70 per wet ton based on the disposal options available
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and costs applicable within this region (2010 costs). The commenter (93.1) stated that at current
processing rates, the city's landfill costs would be $1.4 million annually if it were to abandon its
SSI versus the cost of operation of the FBF at $0.8 million annually. Another commenter (97.1,
127.1) estimated that its annual cost to landfill is $9 million more than incineration. Another
commenter (102.1, 116.1) said that based on typical transportation and disposal costs of ~$ 1,500
-$2,100 for an average truck load of 22-23 wet tons of sludge (depending on distance traveled),
they would be facing annual average operating expenses in excess of $7,500,000 for landfill
disposal (which does not include the capital investment necessary for truck loading systems).
Another commenter (118.1) stated that they would have sent 57,635 wet tons to landfill instead
of the 15,792 dry tons used in the EPA cost analysis; and their landfill disposal costs are twice
what were used in the EPA estimate (actual cost for landfill is $84.56/ton (wet ton), while the
analysis used $4I/ton). One commenter (49.1) estimated costs for landfilling based on a local
city landfill fee of $87/wet ton (~$111,500,000/yr) and the use of high solid centrifuges to get
dry biosolids of 28% TS ($142,000,000/yr); the commenter (49.1) stated that upgrading
incinerator air pollution controls may be less expensive. One commenter (96.1) stated that the
memo "Cost and Emission Reduction of the MACT Floor Level of Control" (dated June 2010)
estimates their MSB's solids production at 84,480 dry tons per year, while their actual production
is approximately 53,655 dry tons per year (5-year average). The commenter (96.1) stated that the
memo under-estimates the actual cost for landfill disposal at $3.7M when the actual landfill
disposal cost would approach $9.3M. The commenter (96.1) also noted that the MSD estimated
landfill costs are based on actual hauling and disposal rates and have not been inflated to account
for potential future cost increases associated with having to procure multiple sources of disposal.
One commenter (115.1) spoke about a June 13, 2008 flood that severely damaged the multiple
hearth incinerator and many other processes. The commenter (115.1) stated that without
incineration as a primary sludge disposal option during flood recovery, their facility experienced
additional operational expenses at a rate of $7M per year on a total budget of $30M. One
commenter (81.1) stated that during incinerator upgrades to achieve compliance with the Part
503 regulations, sludge was disposed by landfilling and the associated trucking and disposal cost
were more than twice that of incineration.
Response: We have revised our costs and impacts of the landfill alternative based on
comments received on the proposal and corrections made to the analysis. Table 14 of the
preamble to the final rule summarizes the revised costs and impacts of this alternative, if small
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entities choose to landfill rather than incinerate sewage sludge. A detailed discussion of the
landfilling alternative analysis is provided in the memorandum "Revised Cost and Emission
Reduction of the MACT Floor Level of Control" in the SSI docket (EPA-HQ-OAR-2009-0559).
Based on the revised impacts, it is unlikely that many sources will find landfilling an
appropriate alternative. However, the selection of a management option for sewage sludge is
often a local decision that is based on environmental protection concerns, community needs,
geographic constraints, and economic conditions. Given a full evaluation of these factors, EPA
recognizes that for some sources, landfilling or land treatment may be a better management
option than incineration.
Comment: Several commenters (61.1, 88.1, 132.1, 136.1) expressed the belief that due to
underestimated costs, the Proposed Standards would result in wastewater utilities bypassing
incineration and simply sending material for disposal at a landfill. Another commenter (75.1)
stated that the proposed regulations would have a "severe negative impact" on already limited
disposal options and would threaten facilities' ability to treat wastewater effectively. Some
commenters (65.1, 101.1, 126.1) argued that the cost to haul and landfill is based on competition
with the facilities that burn and disagreed with EPA that it is cheaper to landfill sludge. These
commenters (65.1, 101.1, 126.1) stated that facilities continue incineration because it is presently
cheaper than landfill or other options, noting that, historically, the usage of SSIs has fluctuated
with the cost of landfilling, which increased when available space decreased. These commenters
(65.1, 101.1, 126.1) stated that many sites are now regional facilities burning sludge from
neighboring communities, and that eliminating these regional incinerators would increase cost to
existing, non burning facilities who must haul further. Another commenter (131.1) stated that
landfill space is a limited resource; and if landfill disposal became the predominant method,
costs would undoubtedly increase further. One commenter (61.1) is concerned about the increase
in landfill tipping fees to dispose of sewage sludge.
Response: We have revised our costs and impacts of the landfill alternative based on
comments received on the proposal and corrections made to the analysis. A detailed discussion
of the landfilling alternative analysis is provided in the memorandum "Revised Cost and
Emission Reduction of the MACT Floor Level of Control" in the SSI docket (EPA-HQ-OAR-
2009-0559).
Based on the revised impacts, it is unlikely that many sources will find landfilling an
appropriate alternative. However, the selection of a management option for sewage sludge is
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often a local decision that is based on environmental protection concerns, community needs,
geographic constraints, and economic conditions. Given a full evaluation of these factors, EPA
recognizes that for some sources, landfilling or land treatment may be a better management
option than incineration.
Comment: Some commenters (129.1, 138) argued that EPA substantially underestimated
the number of trucks required to haul the sludge to municipal solid waste landfills and the truck
emissions. One commenter (129.1) stated that each truck can only hold 15-20 wet tons of
sludge due to the 80,000 pound road loading limitations. The commenter (129.1) also noted that
some states require the sludge to be lime stabilized before it can be land filled; requiring trucks
to haul in lime and increase the number of trucks required and truck emissions. The commenter
(129.1) stated that land filling all of the sewage sludge from one of their facilities starting in
2013 would require approximately 10,500 truck loads per year, making a 130-mile round trip to
the closest current landfill, and would annually cost their customers $9 million more than
incineration. One commenter (73.1) also stated that EPA should be well aware that sewage
sludge tendered by the municipalities to landfills are typically between only 20% to 25% solids,
making transportation costs significant when considering the amount of water (as contained in
the material) being hauled along with the sewage sludge.
Response: We have revised our costs and impacts of the landfill alternative based on
comments received on the proposal and corrections made to the analysis. A detailed discussion
of the landfilling alternative analysis is provided in the memorandum "Revised Cost and
Emission Reduction of the MACT Floor Level of Control" in the SSI docket (EPA-HQ-OAR-
2009-0559).
Based on the revised impacts, it is unlikely that many sources will find landfilling an
appropriate alternative. However, the selection of a management option for sewage sludge is
often a local decision that is based on environmental protection concerns, community needs,
geographic constraints, and economic conditions. Given a full evaluation of these factors, EPA
recognizes that for some sources, landfilling or land treatment may be a better management
option than incineration.
20.2 Landfill Availability Concerns
Comment: Several commenters (61.1, 68.1, 107.1, 71.1, 73.1, 76.1, 83.1, 89.1, 90.1,
93.1, 97.1, 127.1, 106.1, 109.1, 110.1, 111.1, 117.1, 105.1, 103.1, 107.1, 115.1, 120.1, 121.1,
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64.1,68.1,70.1, 129.1, 134.1, 102.1, 116.1, 138, 94.1) are concerned about the availability of a
landfill to a POTW including landfill capacity and/or the long haul distances and truck traffic
that may be required. One commenter (68.1) stated the EPA appears to have assumed that
landfills are readily available to all POTWs, and was concerned because landfills are found few
and far between in most of the north eastern Unites States. Another commenter (107.1) is
concerned about whether EPA considered the distances involved and the total number of vehicle
miles required annually to transport sewage sludge to a landfill. One commenter (71.1) stated
that their landfill is approximately 50 miles away round trip. Another commenter (90.1) stated
that sewage sludge has to be mixed with other wastes when being placed into a landfill cell, for
stability purposes, and landfills have daily limits on the total quantity of waste that they can
manage. Another commenter (97.1, 127.1) stated that they would need to dispose of an
additional 600 tons per day of sewage sludge that is 75 percent water after pressing/dewatering,
and that their closest landfill (65 miles away) will not be able to handle all of its sludge and they
have not been able to identify a landfill that will accept the necessary volume or type (wet) of
biosolids. Other commenters (67.1, 105.1) stated that there is insufficient landfill capacity in CT
for disposal of wastewater treatment plant sludge, which would necessitate trucking of sludge to
out-of-state landfills. One commenter (110.1) asserted that EPA did not take into consideration
the scarcity of landfills capable of accepting large quantities of sewage sludge. One commenter
(105.1) is concerned that if they were to abandon incineration it could result in approximately 80
to 100 trucks per week hauling sludge out of the state; and the Connecticut DEP has expressed
significant concerns with the additional truck traffic in the state since Connecticut has been
classified as non-attainment for ozone. Another commenter (106.1) stated that they would need
to send out more than one truck per hour, 24 hours a day, 7 days a week. Two commenters
(111.1, 117.1) stated that the landfill that is willing to accept their biosolids is 270 miles away.
The commenters (111.1, 117.1) asserted that a container would sit in our parking lot to be hauled
away each day by the company managing the landfill; the container would be hauled by semi
truck to downtown Seattle, where it would be put on a rail car and taken to the landfill by train.
One commenter (103.1) is concerned that landfill stabilized sludge from their facilities would
require 24,000 truck shipments per year, or 96 loads per weekday. Another commenter (120.1)
stated that there is not enough landfill capacity within a 100-mile radius to handle their average
of 188 wet tons/day of dewatered sludge. The commenter (120.1) stated that at the current cost of
$80.00 per wet ton, the cost to landfill all of their dewatered sludge would be approximately
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$5.48 million per year (this is in comparison to an estimated cost of $1.75 million per year for
the incinerating the same volume of dewatered sludge). Another commenter (121.1) said that it is
approximately 70 miles round trip for them to the nearest landfill and would result in 850 truck
loads per year and close to 60,000 miles of truck travel. Another commenter (58) stated that the
state of New Jersey would need to allow additional landfills to open to provide competition in
the market, in order to avoid price gouging by the limited existing landfills and haulers. One
commenter (64.1) performed an analysis of existing landfills that are used by current New Jersey
authorities, and reported that the closest available landfills being utilized are in Ohio and
Virginia, over 400 miles and over 300 miles away respectively. One commenter (68.1) stated
that landfills are remote and available opportunities for land application are essentially
nonexistent in southern New England. The commenter (68.1) stated that sewage sludge
combustion is the only cost-effective alternative open to southern New England, and in turn, they
are about the only option available to the nearly twenty other Massachusetts and New England
communities they provide solids management to. One commenter (70.1) stated that trucking
sludge from the northeast corner of New Jersey across the entire state to landfills in Pennsylvania
(the closest disposal location) would be prohibitively expensive and an inappropriate
environmental approach. Another commenter (73.1) stated that if the SSIs operated by Synagro
and others in Rhode Island, Massachusetts and Connecticut, were shut down, the result will be
approximately 3000 wet tons per day of sewage sludge being hauled hundreds of miles to
landfills outside of the Northeast due to the lack of local landfill capacity to manage this
material. One commenter (67.1) is concerned because their district has no other options because
there are no longer any feasible environmentally friendly, cost-effective sludge disposal options
in Connecticut. The commenter (67.1) estimated that the cost to truck its dewatered sludge to
another incinerator is estimated at $2 million per year, and to an out-of-state landfill it is
estimated at $4 million per year: seven trailer trucks per day, seven days per week. The
commenter (67.1) stated that two years of landfilling exceeds the costs of these additional
emissions control systems arguing that it is obvious that landfilling sewage sludge at an out-of-
state landfill is not a more economically advantageous option to operating their SSI. Another
commenter (81.1) stated that during recovery from a 2009 500-year flood disaster, landfill
disposal of sludge was utilized exclusively, which not only increased costs but also presented
capacity limitations on the sludge disposal quantities.
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Response: We have revised our costs and impacts of the landfill alternative based on
comments received on the proposal and corrections made to the analysis. EPA recognizes that
the selection of a management option for sewage sludge is often a local decision that is based on
environmental protection concerns, community needs, geographic constraints, and economic
conditions. EPA is not requiring landfilling and did not require it in the NPRM; it is an
alternative option evaluated. Based on the revised impacts, it is unlikely that many sources will
find landfilling an appropriate alternative. However, the selection of a management option for
sewage sludge is often a local decision that is based on environmental protection concerns,
community needs, geographic constraints, and economic conditions. Given a full evaluation of
these factors, EPA recognizes that for some sources, landfilling or land treatment may be a better
management option than incineration.
20.3 Odor Concerns
Comment: Several commenters (96.1, 106.1, 107.1, 109.1, 132.1, 97.1, 127.1, 138) are
concerned about the odor that will be created by hauling and/or land filling sewage sludge. One
commenter (96.1) stated that the memo titled "Cost and Emission Reduction of the MACT Floor
Level of Control" dated June 2010 fails to consider the negative social impact of a hauling and
landfill alternative to incineration. The commenter (96.1) stated that it currently sends
approximately 15% of its solids to a landfill and occasionally receives complaints regarding
odors emanating from tractor trailers hauling the material; the landfill owner and operations
staffs have expressed resistance at accepting even this amount of sludge due to odor issues and
other concerns. The commenter (96.1) is concerned the landfill will not accept anymore volume
and they will be forced to find multiple sources of disposal sites, some of which are located well
outside our metropolitan area, requiring longer drives. One commenter (107.1) stated that nearby
landfills are not interested in taking all of the sludge produced at their facilities due to odor
concerns and the potential for landfill instability. Another commenter (106.1) stated that there is
not one community or transportation route that is going to tolerate for very long the volume of
smelly truck traffic required get all of this sludge to a landfill. Another commenter (132.1) stated
that they have experienced bans from local landfills due to biosolids odor, forcing them to use
landfills at greater distance to the facility (adding to their disposal cost when incineration was not
available due to scheduled or unscheduled shutdowns). Conversely, one commenter (129.1)
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stated that their incinerator capacity allows for the immediate processing of all of its sewage
sludge without significant storage thus reducing odors.
Response: We have revised our costs and impacts of the landfill alternative based on
comments received on the proposal and corrections made to the analysis. EPA recognizes that
the selection of a management option for sewage sludge is often a local decision that is based on
environmental protection concerns, community needs, geographic constraints, and economic
conditions. EPA is not requiring landfilling and did not require it in the NPRM; it is an
alternative option evaluated. Based on the revised impacts, it is unlikely that many sources will
find landfilling an appropriate alternative. However, the selection of a management option for
sewage sludge is often a local decision that is based on environmental protection concerns,
community needs, geographic constraints, and economic conditions. Given a full evaluation of
these factors, EPA recognizes that for some sources, landfilling or land treatment may be a better
management option than incineration.
20.4 State Land Filling Regulation Concerns
Comment: Some commenters (75.1, 71.1, 110.1, 107.1) are concerned about the
additional costs for specific State land filling regulations that EPA did not consider. One
commenter (75.1) stated that Pennsylvania Code Chapter 273 Section 513 requires that sewage
sludge be treated with one of the processes to meet Class B pathogen requirements as well as
vector attraction reduction before being accepted by a landfill. One commenter (71.1) is
concerned that Virginia regulations require that all sewage sludge must be lime stabilized before
it can be accepted at a landfill. The commenter (71.1) estimated $2 million per year for lime
stabilization and hauling (excluding the cost of installing a lime silo, pug mill, conveyors, sludge
storage, etc.). Another commenter (121.1) also mentioned they would need to add lime or other
chemicals to the sludge as part of the process to meet stabilization requirements, which in turn
also adds to the weight of solids disposed at a landfill. Other commenters (101.1, 110.1, 67.1,
117.1) are concerned about State and local regulations that are in place to restrict land filling of
sewage sludge. One commenter (107.1) pointed out that in the State of Washington land filling
of sewage sludge is currently permitted only in emergency circumstances. Another commenter
(110.1) pointed out that in California and other states there are statutory requirements to divert
organic material like sewage sludge away from landfills. One commenter (67.1) stated that a
major factor limiting wastewater sludge management options in Connecticut are regulatory
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constraints which make land application and composting unfeasible. The commenter (67.1)
stated that there are no regional landfills left in Connecticut, Massachusetts and Rhode Island
that can accept wastewater sludge. Another commenter (117.1) stated that their State policy
considers sewage sludge not a solid waste. One commenter (68.1) stated that they invested in a
combustion system based on the set of regulations that were in place under part 503 standards
and on Massachusetts air pollution control standards. The commenter (68.1) argued that their
investment was intended to provide a long term solution for sewage sludge management in
central Massachusetts where there are very few alternative management options.
Some commenters (101.1, 126.1) stated that land filling (of sewage sludge) is illegal in
New Jersey and there is limited space available for land application. One commenter (64.1)
referred to New Jersey's Statewide Sludge Management Plan and stated that it is the
Department's Policy to prohibit the landfill disposal of sewage sludge because land filling is a
land-intensive waste disposal mode which commits land areas for the foreseeable future. The
commenter (64.1) stated that the plan does permit landfill disposal of sewage sludge only on a
short-term basis under limited overriding circumstances as determined by the Department under
the terms of an Administrative Consent Order. In addition, the commenter (64.1) pointed out that
it is the Department's Policy that sewage sludge thermal reduction facilities are an integral and
necessary part of the State's diversified sewage sludge management strategy; dedicated sewage
sludge thermal reduction facilities impart a vast volume reduction on the sewage sludge
introduced into the facilities, do not require significant land commitment for disposal, operate in
all seasons, safely manage one quarter of the State's sewage sludge production without nuisance,
and are fully regulated by the Department's Air Pollution Control Program.
Response: EPA thanks the commenters for their input. EPA is not requiring landfilling
and did not require it in the NPRM; it is an alternative option evaluated. EPA recognizes that the
selection of a management option for sewage sludge is often a local decision that is based on
environmental protection concerns, community needs, geographic constraints, and economic
conditions. We have revised our costs and impacts of the landfill alternative based on comments
received on the proposal and corrections made to the analysis. We incorporated data provided by
commenters on the availability of landfills in our assumptions on trucking distances. Based on
the revised impacts, it is unlikely that many sources will find landfilling an appropriate
alternative. However, the selection of a management option for sewage sludge is often a local
decision that is based on environmental protection concerns, community needs, geographic
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constraints, and economic conditions. Given a full evaluation of these factors, EPA recognizes
that for some sources, landfilling or land treatment may be a better management option than
incineration.
20.5 Additional Expenditures and Site Constraints
Comment: Some commenters (83.1, 90.1, 93.1, 94.1, 96.1, 97.1, 127.1, 115.1, 121.1,
129.1, 134.1, 102.1, 116.1, 138) are concerned that EPA did not consider the need for additional
capital and/or infrastructure expenditures for on-site storage, odor control, materials handling,
truck loading, etc. One commenter (83.1) is concerned about pad storage to house materials until
they can be sent to the landfill—if storage on-site is even an option given the footprint of the
facility. One commenter (102.1) noted that wastewater treatment plants operate 24/7/365, while
landfills typically operate on a more traditional 8 hours/day - 5 day/week schedule. Another
commenter (115.1) noted that the additional operational expenses (such as storage options)
would be necessary to address the fact that landfills are open only 5 or maybe 5.5 days per week
and sludge is generated 7 days per week regardless of weekends, winter, or prolonged wet
weather. Another commenter (93.1) stated that it would need to abandon its SSI and add
anaerobic digestion or similar process to produce a biosolids product resulting in capital
expenditures in the tens of millions of dollars and increased operating costs. Another commenter
(94.1) stated that their 2-story, 13,860 sq. ft., incineration building was erected in 1995 and is
valued at $12,000,000 dollars; their process includes state-of-the-art emissions controls valued
alone at over $700,000 which does not include a separate odor control tower and associated
equipment as well as a 140' by 160' poured concrete ash settling basin. Another commenter
(96.1) stated that the memo significantly under-estimates the capital cost associated with
constructing load-out and odor control facilities for a landfill disposal operation. Other
commenters (97.1, 127.1, 129.1) stated that there would be additional costs, estimated to cost
over $50 million, for a loading and storage facility that can accommodate up to 12 trucks per
hour for their facility. The commenter (97.1, 127.1) argued that these additional costs are
difficult to justify when they do not reduce emissions and they eliminate the opportunity to use
sewage sludge as a viable alternative energy source for electricity and steam generation. One
commenter (121.1) stated that their facility will need to be retrofitted for additional dewatered
sludge conveyance and storage, loading facilities, and due to the high volume of sludge to be
transported, supplementary sludge hauling equipment (trucks) would also be required. Another
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commenter (129.1) stated that in order to land apply their sewage sludge, a new alkaline
stabilization facility would have to be constructed, since their facility does not have digesters,
nor does it have the room to construct digesters. The commenter (129.1) stated that land
application of an alkaline stabilized Class A product would require 13,700 - 14,700 truck loads
per year, making a round trip of at least 150- miles to land application sites and would annually
cost customers $ 10 - 11 million more than incineration. Another commenter (134.1) was also
concerned that EPA has not taken into account the cost for stabilization and on-site storage of
dewatered solids. The commenter (134.1) stated that many landfills require stabilization that will
require the addition of digestion, thermal drying, or lime stabilization that will greatly affect the
capital and operating costs.
Response: We have revised our costs and impacts of the landfill alternative based on
comments received on the proposal and corrections made to the analysis. A detailed discussion
of the landfilling alternative analysis is provided in the memorandum "Revised Cost and
Emission Reduction of the MACT Floor Level of Control" in the SSI docket (EPA-HQ-OAR-
2009-0559). The revisions include updated costs for storage and waste management equipment.
Based on the revised impacts, it is unlikely that many sources will find landfilling an appropriate
alternative. However, the selection of a management option for sewage sludge is often a local
decision that is based on environmental protection concerns, community needs, geographic
constraints, and economic conditions. Given a full evaluation of these factors, EPA recognizes
that for some sources, landfilling or land treatment may be a better management option than
incineration.
Comment: Two commenters (111.1, 117.1) are concerned about site constraints because
there is no location within their plant to construct a sludge loading area for a container, and the
facility is hemmed in on all sides. Another commenter (129.1) said that their three WWTPs do
not have the available land space to construct facilities to store liquid and dewatered sewage
sludge. The commenters (111.1, 117.1) stated that the only location for a sludge container would
be in the parking lot with employee and visitor cars. The commenters (111.1, 117.1) stated that
even if it was determined acceptable to leave a huge container in the middle of the parking lot
every day for the life of the facility, scheduling the hauling of the container makes the idea
impractical (as the container would need to be removed daily to keep up with sludge production,
including weekends and holidays). The commenters (111.1, 117.1) pointed out that on days
when snow and ice would prevent the hauler from removing the container, the City has no means
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of moving the massive containers, and no place to move it to until the road conditions improved
for the contract hauler to pick it up. The commenters (111.1, 117.1) asserted that choosing to rely
on moving sludge containers from the only parking lot in the plant for the next 50 years causes
an unacceptable amount of liability and risk to the City.
One commenter (117.1) stated that as a small utility serving a population of 50,000, they
would significantly impacted by the proposed standards. The commenter (117.1) stated that they
would be required to add additional equipment to remove the small amount of mercury and other
listed contaminants that pass through our incinerator, as well as provide additional staffing and
training to maintain the equipment and prepare the required reports. The commenter (117.1)
stated that due to the geography of their location, access to the facility is limited by a long,
narrow, winding and steep driveway (making trucking unreliable), and that the site is completely
built out with little room to add additional processes or equipment. The commenter (117.1)
asserted that these challenges make the options of trucking sludge to a landfill or drying sludge
not viable. The commenter (117.1) also noted that the sludge produced at the facility is wet (~
24% solids), not easily transported, and not accepted at any landfill within a hundred mile radius.
Response: EPA thanks the commenter for their input. EPA recognizes that the selection
of a management option for sewage sludge is often a local decision that is based on
environmental protection concerns, community needs, geographic constraints, and economic
conditions. We have revised our costs and impacts of the landfill alternative based on comments
received on the proposal and corrections made to the analysis. We have also revised the final
emission limits and impacts analysis. Additionally, we are not selecting any beyond-the-floor
options for the final rule. Based on the revised impacts, it is unlikely that many sources will find
landfilling an appropriate alternative. However, the selection of a management option for sewage
sludge is often a local decision that is based on environmental protection concerns, community
needs, geographic constraints, and economic conditions. Given a full evaluation of these factors,
EPA recognizes that for some sources, landfilling or land treatment may be a better management
option than incineration.
20.6 Greenhouse Gas Emissions and Environmental Concerns
Comment: Several commenters (96.1, 97.1, 127.1, 129.1, 102.1, 116.1, 138) argued that
incineration actually produces much less greenhouse gas emissions than land filling. One
commenter (129.1) stated that for a number of pollutants, the environmental burden is lower with
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on-site incineration of sewage sludge than with additional processing and off site management.
One commenter (96.1) provided a table showing that greenhouse gas production for a landfill
option will be 4 times greater than for MHF incineration, and 9 times greater than for FB
incineration. The commenter (96.1) argued that greenhouse gas emissions will be significantly
greater due to the volume increase from hauling, and methane release from cake solids applied to
a landfill has 21 times the greenhouse gas forming potential of carbon dioxide. One commenter
(85.1) argued that EPA did not consider environmental impacts and consequences of land filling
sewage sludge. Another commenter (129.1) asserted that land application and land filling may
actually result in higher emissions than those produced during incineration because of the
distances sewage sludge must be transported. The commenter (129.1) provided a table containing
air emissions from three incinerators and trucks used to transport the sludge to landfill or land
application sites; the table shows that emissions of carbon monoxide, oxides of nitrogen, sulfur
dioxide and organics from three new fluidized bed incinerators being constructed at a WWTP
will be lower or equal to the emission levels from land application and land filling. One
commenter (75.1) reasoned that the potential harm to the environment would be greater than the
air quality improvements to be achieved. Another commenter (102.1, 116.1) said that the carbon
footprint is likely to be much larger for landfill disposal than the incineration process. Another
commenter (138) stated that for their multiple hearth incinerators, greenhouse gas emissions
equate to 7,300 ton equivalents, and land filling would generate 27,000 ton equivalents.
One commenter (128.1) argued that the transport of sewage sludge for land application
and land filling creates additional vehicle emissions, and the increased sewage sludge in landfills
generates added methane emissions. Commenters (97.1, 127.1) stated that air emissions
associated with trucking sewage sludge to landfill exceed the air emissions from incineration,
and asserted that additional environmental benefits accrue when incineration is used to generate
steam and/or electricity that offsets the need to burn fossil fuels. The commenters (97.1, 127.1)
stated that incineration was the "greener" option for their POTW, and provided a comparison of
estimates of criteria emissions from truck traffic and incineration. One commenter (107.1)
expressed concerns about the anaerobic decomposition of hundreds of thousands of tons of
sewage sludge because it is going to generate significant quantities of gasses, which the
commenter stated would add to the deleterious effects on the atmosphere of the fuel burned to
transport the sludge. Other commenters (107.1) argued that the effect on human health of the all
of the vehicle emissions that will be produced to transport hundreds of thousands of tons of
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sludge, hundreds of thousands of miles annually needs to be compared against the actual
reduction of pollutants emitted by the SSIs.
One commenter (128.1) stated that incineration is a more cost-effective option for many
communities; and produces environmental benefits by reducing odors from storage and loading,
destroying pathogens at high temperature, and by displacing fossil fuel otherwise needed to
generate steam and increasingly to produce electricity. One commenter (73.1) stated that high
temperature associated with incineration ensures the destruction of pathogens, odors, other
organic compounds in the sewage sludge. Another commenter (76.1) argued that EPA has not
considered the potential GHG emissions that will occur if all the sludge currently incinerated is
suddenly placed in a landfill or land applied. The commenter (76.1) stated that incineration has
been shown by Metropolitan St. Louis Sewer District as the least GHG producing method of
disposal. The commenter (76.1) stated that they recycle methane gas from a closed landfill in
combination with the plant generated sludge as energy sources in the MHF process. The
commenter (76.1) stated that heat created in this process is utilized to create enough steam
necessary to provide oxygen to the microbes in the biological treatment process at the plant,
essentially removing load from the power grid. The commenter (76.1) urged EPA to consider if
the proposed limits are reasonable from a non-air quality standpoint and if the limits are
reasonable considering energy requirements such as truck hauling and the associated GHG
emissions from surface placement of methane producing sludge to determine if landfill
placement is a viable alternative to incineration.
One commenter (125) argued that EPA should encourage the use of sewage sludge as a
renewable energy to combat climate change. The commenter (125) asserted that even the most
efficient landfill gas systems are predicted to capture only 90% of the generated landfill gas; and
older gas collection systems are predicted to capture only 75% of the created landfill gas. The
commenter (125) stated that methane emissions are 21 times more harmful than carbon dioxide
based on their global warming potential; and argued that the method of thermal processing
biosolids would have a net environmental benefit [compared to land filling]. The commenter
(125) added that if local thermal processing facilities could be used to treat sewage sludge as
opposed to land filling, there would be a reduction in truck emissions because some of the
landfills used by Southern California waste water treatment plants are located hundreds of miles
away in Arizona or Kern County. One commenter (134.1) requested that EPA include both
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fugitive and captured landfill gas emissions in its comparison emission calculations. The
commenter (134.1) stated that the effect on GHG emissions should not be ignored.
Response: At proposal, we evaluated landfilling as an alternative disposal method. We
have revised our costs and impacts of this alternative based on comments received on the
proposal and corrections made to the analysis. We have also revised the final emission limits and
impacts analysis. A detailed discussion of the landfilling alternative analysis is provided in the
memorandum "Revised Cost and Emission Reduction of the MACT Floor Level of Control" in
the SSI docket (EPA-HQ-OAR-2009-0559). Additionally, we are not selecting any beyond-the-
floor options for the final rule. Based on the revised impacts, it is unlikely that many sources will
find landfilling an appropriate alternative. However, the selection of a management option for
sewage sludge is often a local decision that is based on environmental protection concerns,
community needs, geographic constraints, and economic conditions. Given a full evaluation of
these factors, EPA recognizes that for some sources, landfilling or land treatment may be a better
management option than incineration.
Comment: One commenter (112.1) stated that land filling was identified as the least-
preferred disposal option in the Solids Treatment and Utilization Master Plan (STUMP), drafted
in 2009. The commenter (112.1) pointed out that the STUMP identified incineration as an
essential component of the future biosolids management program for the City of Columbus,
Ohio, Department of Public Utilities. The commenter (112.1) stated that the STUMP was
developed with guidance from agricultural, commercial, and utility stakeholders and utilized a
comprehensive material flow optimization framework to optimize operations to minimize cost,
energy usage, and GHG emissions. Another commenter (73.1) argued that land filling of a
valuable, recyclable material runs contrary to the mandates of many jurisdictions seeking to meet
both landfill diversion and greenhouse gas emission goals by reducing their volume of waste
being disposed of in landfills as they are faced with decreasing amount of available landfill
space.
Response: EPA is not requiring landfilling and did not require it in the NPRM; it is an
alternative option evaluated. We have revised our costs and impacts of this alternative based on
comments received on the proposal and corrections made to the analysis. A detailed discussion
of the landfilling alternative analysis is provided in the memorandum "Revised Cost and
Emission Reduction of the MACT Floor Level of Control" in the SSI docket (EPA-HQ-OAR-
2009-0559). Additionally, we are not selecting any beyond-the-floor options for the final rule.
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Based on the revised impacts, it is unlikely that many sources will find landfilling an appropriate
alternative. However, the selection of a management option for sewage sludge is often a local
decision that is based on environmental protection concerns, community needs, geographic
constraints, and economic conditions. Given a full evaluation of these factors, EPA recognizes
that for some sources, landfilling or land treatment may be a better management option than
incineration.
Comment: One commenter (129.1) is concerned that the proposed rule could have a
significant impact on energy supply, distribution or use. The commenter (129.1) stated that if
POTWs are forced to shut down their incinerators and haul their sludge to a landfill, the use of
diesel fuel will significantly increase since the trucks average four (4) miles per gallon. As a
result, the commenter would specifically use a minimum of 350,000 gallons of diesel fuel to
transport its sludge to landfill and a minimum of 600,000 gallons of diesel fuel to transport the
Class A product to land application sites. The commenter (129.1) stated that this does not include
the diesel fuel that would be used by the trucks required to haul lime from the quarries to our
plants or carbon from the processing plants to our plants.
Response: EPA is not requiring landfilling and did not require it in the NPRM; it is an
alternative option evaluated. We have revised our costs and impacts of this alternative based on
comments received on the proposal and corrections made to the analysis. A detailed discussion
of the landfilling alternative analysis is provided in the memorandum "Revised Cost and
Emission Reduction of the MACT Floor Level of Control" in the SSI docket (EPA-HQ-OAR-
2009-0559). We have revised the fuel emission limits and impacts analysis. Additionally, we are
not selecting any beyond-the-floor options for the final rule. Based on the revised impacts, it is
unlikely that many sources will find landfilling an appropriate alternative. However, the selection
of a management option for sewage sludge is often a local decision that is based on
environmental protection concerns, community needs, geographic constraints, and economic
conditions. Given a full evaluation of these factors, EPA recognizes that for some sources,
landfilling or land treatment may be a better management option than incineration.
20.7 Other
Comment: Several commenters (58, 63.1, 68.1, 69.1, 70.1, 74.1, 78.1, 81.1, 87.1, 94.1,
101.1, 103.1, 105.1, 106.1, 111.1, 113.1, 114.1, 115.1, 118.1, 120.1, 126.1, 129.1, 132.1, 138,
72.1, 76.1, 90.1 93.1, 61.1) stated that selection of a management option for sewage sludge is a
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local decision [...] based on environmental protection concerns, community needs, geographic
constraints, economic conditions and many other considerations. Other commenters (105.1,
137.1) stated that EPA should evaluate the various disposal options on a regional basis because
costs vary by location and region. These commenters (105.1) stated that in the Northeast,
landfills are generally much more expensive than other areas of the country, do not have the long
term capacity, and they are not always located close to facilities with SSIs. Commenter (101.1,
126.1) argued that incineration is the environmentally appropriate, as well as, cost effective
manner in which to dispose of sewage sludge. One commenter (71.1) stated 80 percent of the
wastewater treated at their facility originated from industrial sources, noting that because of the
high industrial mix of their wastewater, incineration was chosen as the best management option
for sludge. A number of commenters (75.1, 78.1) stated they maintain multiple options for
sewage sludge disposal such as incineration, land application, and land filling. One commenter
(138) added that they incinerate about 85 percent of their solids, but did not indicate how they
handle the balance. One commenter (134.1) requested that EPA confirm that the "haul to
landfill" option was only used as an example, and that wastewater plants need to select the solids
management practice most effective for their local conditions.
Response: EPA recognizes the selection of a management option for sewage sludge is
often a local decision. EPA is not requiring landfilling and did not require it in the NPRM; it is
an alternative option evaluated. We have revised our costs and impacts of the landfill alternative
based on comments received on the proposal and corrections made to the analysis. A detailed
discussion of the landfilling alternative analysis is provided in the memorandum "Revised Cost
and Emission Reduction of the MACT Floor Level of Control" in the SSI docket (EPA-HQ-
OAR-2009-0559). The revisions included storage, mileage, and cost data provided by
commenters.
Comment: One commenter (73.1) stated that the incineration process results in a 90 -
95% reduction in volume and the production of a non-hazardous, non-toxic, ash that is
beneficially reused throughout the U.S. Another commenter (138) provided information about
their cost benefits for ash reuse. The commenter (138) stated that with their land application
permit, they are able to save about $400,000 over a three year period as their costs for ash reuse
is $134,000 over a three year period while land filling is estimated to cost them $534,000 over a
three year period. One commenter (110.1) believes more consideration should have been given
to land application as an alternative option.
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Response: EPA thanks the commenter for their input. Our revisions to landfill impacts
include revisions to transportation and storage needs, which would be applicable to land
treatment. Table 14 of the preamble to the final rule summarizes the revised costs and impacts of
this alternative, if small entities choose to landfill rather than incinerate sewage sludge. A
detailed discussion of the landfilling alternative analysis is provided in the memorandum
"Revised Cost and Emission Reduction of the MACT Floor Level of Control" in the SSI docket
(EPA-HQ-OAR-2009-0559). Based on the revised impacts, it is unlikely that many sources will
find landfilling an appropriate alternative. However, the selection of a management option for
sewage sludge is often a local decision that is based on environmental protection concerns,
community needs, geographic constraints, and economic conditions. Given a full evaluation of
these factors, EPA recognizes that for some sources, landfilling or land treatment may be a better
management option than incineration.
Comment: One commenter (64.1) disputed USEPA's assumption that "incineration
continues to be utilized to dispose of sewage sludge, but is increasingly becoming less common."
The commenter (64.1) stated that in New Jersey, for calendar year 2009, management by sewage
sludge incineration accounted for about 24 percent of the state's sludge production (the total
amount of sludge managed via sewage sludge incineration in 2009 was over 52,000 dry metric
tons), and this was an increase over 2008 when about 21 percent of the state's sludge production
was managed via incineration, and only a slight decrease from ten years ago when about 26
percent of the state's sludge production was managed via incineration. The commenter (64.1)
stated that there are eight sewage sludge incinerators operating in the State, and there are an
additional 107 domestic treatment works that rely on these incinerators for sewage sludge
disposal. The commenter (64.1) is concerned that a potential loss of one-quarter of the state's
current sludge disposal alternatives (and a much larger percent of the state's available capacity)
could have potential negative economic impacts beyond the eight operators of sewage sludge
incinerators. The commenter (64.1) urged the EPA to carefully consider all costs and the benefits
derived, versus the potential negative consequences, prior to finalizing the proposed rule.
Response: EPA is not requiring landfilling and did not require it in the NPRM; it is an
alternative option provided. EPA has considered commenters' concerns and revised the cost and
impacts analysis accordingly. Table 14 of the preamble to the final rule summarizes the revised
costs and impacts of this alternative, if small entities choose to landfill rather than incinerate
sewage sludge. A detailed discussion of the landfilling alternative analysis is provided in the
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memorandum "Revised Cost and Emission Reduction of the MACT Floor Level of Control" in
the SSI docket (EPA-HQ-OAR-2009-0559). Based on the revised impacts (as discussed above),
it is unlikely that many sources will find landfilling an appropriate alternative. The selection of a
management option for sewage sludge is often a local decision that is based on environmental
protection concerns, community needs, geographic constraints, and economic conditions. Given
a full evaluation of these factors, for some sources, landfilling or land treatment may be a better
management option than incineration.
Comment: Some commenters (65.1, 101.1, 126.1) are concerned about the debt that
some SSI systems may have to continue pay even though the equipment would be no longer in
use (should the site be required to landfill sludge). The commenters (65.1, 126.1) provided an
example where a site with a new renovation would still have to repay the $5,000,000 debt to the
State and bondholders even if it were forced into land filling the sludge.
Response: EPA is not requiring landfilling and did not require it in the NPRM; it is an
alternative option evaluated. For some sources, landfilling or land treatment may be a better
management option than incineration.
Comment: One commenter (102.1, 116.1) asked how any insurance carrier or
municipality will predict and account for the liabilities of over the road transportation accidents
where sewage sludge will inevitably be discharged onto ground and water surfaces.
Response: EPA is not requiring landfilling and did not require it in the NPRM; it is an
alternative option evaluated. We have revised our costs and impacts of the landfill alternative
based on comments received on the proposal and corrections made to the analysis. A detailed
discussion of the landfilling alternative analysis is provided in the memorandum "Revised Cost
and Emission Reduction of the MACT Floor Level of Control" in the SSI docket (EPA-HQ-
OAR-2009-0559). The revisions included storage, mileage, and cost data provided by
commenters. Based on the revised impacts (as discussed above), it is unlikely that many sources
will find landfilling an appropriate alternative. The selection of a management option for sewage
sludge is often a local decision that is based on environmental protection concerns, community
needs, geographic constraints, and economic conditions. Given a full evaluation of these factors,
for some sources, landfilling or land treatment may be a better management option than
incineration.
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Comment: One commenter (82.1) stated that if facilities decide to switch to landfilling or
land applying sludge as a result of this rule, they would also benefit from technical assistance in
setting up a new program for sludge disposal.
Response: We have revised our costs and impacts of the landfill alternative based on
comments received on the proposal and corrections made to the analysis. A detailed discussion
of the landfilling alternative analysis is provided in the memorandum "Revised Cost and
Emission Reduction of the MACT Floor Level of Control" in the SSI docket (EPA-HQ-OAR-
2009-0559). Based on the revised impacts (as discussed above), it is unlikely that many sources
will find landfilling an appropriate alternative. The selection of a management option for sewage
sludge is often a local decision that is based on environmental protection concerns, community
needs, geographic constraints, and economic conditions. Given a full evaluation of these factors,
for some sources, landfilling or land treatment may be a better management option than
incineration.
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21.0 RELATIONSHIP TO CAA SECTIONS 112(C)(3) AND
112(K)(3)(B)(II) (AREA SOURCES)
Comment: One commenter (84.1, 119.1) agreed with EPA's conclusion that the Clean
Air Act unambiguously requires it to set §129 standards for SSI (see 75 Fed. Reg. at 63263-
63264). The commenter (84.1, 119.1) stated that the agency's previous attempts to avoid setting
such standards contravened §129's mandate to set §129 standards for all solid waste incineration
units and definition of such units to include any facility that burns any solid waste material at all
other than those types of unit that § 129(g)(l) expressly excludes. The commenter (84.1, 119.1)
stated that if EPA did not set §129 standards for SSIs, the agency would leave a major category
of polluters without necessary controls. The commenter (84.1, 119.1) argued that few, if any, SSI
are "major" sources for the purposes of §112, even though EPA's baseline emissions estimates
show that SSI are dangerous toxic polluters both as a category and individually; therefore,
attempting to regulate SSI under §112 instead of §129 would not only be flatly unlawful but
would leave these polluters operating without meaningful control, monitoring and reporting
requirements. The commenter (84.1, 119.1) stated that it is precisely because all incinerators -
including SSI - are so dangerous, that the Clean Air Act §129 requires MACT standards and
Title V permits for all incinerators. The commenter (84.1, 119.1) argued that EPA's GACT
standards (for sources that are not "major" for §112) have achieved only minimal reductions in
emissions, and exempting sources from Title V permitting would deprive neighboring
communities of the benefits Title V permits provide; citizens in those communities would be
unable to learn the identity and quantity of the toxic emissions to which they are being exposed
by a specific facility, and to determine whether that facility is in or out of compliance with its
emission standards. The commenter (84.1, 119.1) purported that industry groups are effectively
seeking to avoid any meaningful obligation to control, monitor, or report their toxic emissions -
a position that is both devoid of legal merit and deplorable. The commenter (84.1, 119.1) agreed
with EPA's rejection to the industry group's arguments regarding this issue, and incorporated by
reference the response comments on EPA's previous SSI proposal (see August 14, 2006
Comments of Earthjustice and Sierra Club).
Response: EPA thanks the commenter for their input.
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22.0 RELATIONSHIP TO OTHER SSI RULES FOR THE USE OR
DISPOSAL OF SEWAGE SLUDGE
Comment: Several commenters (64.1, 82.1, 134.1) noted that establishing the proposed
rule under 40 CFR part 60 would subject SSIs to two sets of requirements (numerical standards,
operational standards, monitoring, recordkeeping and reporting) under both the Clean Water Act
(40 CFR Part 503) and the Clean Air Act (40 CFR Part 60). One commenter (64.1) noted, as
acknowledged in the proposed rule, that the emission limits for inorganic pollutants under Part
503 are risk-based numbers, while the Clean Air Act MACT standards are technology-based, and
created an additional burden for these facilities. Several of these commenters (64.1, 82.1, 110.1)
requested that EPA coordinate and consolidate the rule processes prior to finalizing the proposed
rule, in order to reduce the burden on facilities, reduce conflict between rules, and to minimize
risk from the incineration of sewage sludge.
Response: As the commenter noted, EPA acknowledged the differences between the part
503 regulations and the proposed standards in the NPRM, and discussed the potential impacts to
current SSI facilities that may arise because they are regulated under both part 503 and the
proposed standards. Based on a revised analysis for the final rule, we still expect that the
regulation of sewage sludge under CAA section 129 would result in stricter emission standards
than under the current CWA rule. EPA plans to evaluate the requirements under the CWA to
determine what changes, if any, should be made to the part 503 regulations.
Comment: One commenter (48.1) stated that POTWs are subject to numerous
regulations with recordkeeping and reporting requirements including permits on effluent
discharge, air discharge, and site stormwater. The commenter (48.1) stated that EPA must
consider that numerous unfunded mandates continue to be developed for the industry in a time of
economic hardship. The commenter (48.1) stated that the proposed rule needs to be coordinated
in concert with funding mechanisms in order for utilities to meet the mandated activities. The
commenter (48.1) also stated that in order to abandon the use of multiple hearth incinerators, a
seven year period from the start of a Request for Proposals would be realistic.
Response: EPA thanks the commenter for their suggestions and concerns however this
rule does not contain a federal mandate that may result in expenditures of $100 million or more
for state, local, and tribal governments, in the aggregate, or the private sector in any one year.
Thus, this final rule is not subject to the requirements of sections 202 or 205 of UMRA. This
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final rule is not subject to the requirements of section 203 of UMRA because it contains no
regulatory requirements that might significantly or uniquely affect small governments. Because
this final rule's requirements apply equally to SSI units owned and/or operated by governments
or SSI units owned and/or operated by private entities, there would be no requirements that
uniquely apply to such government or impose any disproportionate impacts on them. EPA
believes that all existing SSI units will choose to comply with the final rules and the timeline for
compliance is realistic.
Comment: Some commenter (134.1) stated that the proposed rule is redundant. One
commenter (134.1) stated that all of the pollutants covered by the proposed regulation have been
adequately managed under the limits and technological requirements of the EPA 503 regulations,
coupled withNESHAPS, NSPS and parallel regulations in individual jurisdictions. The
commenter (134.1) stated that a full complement of data needs to be collected and a valid cost-
benefit analysis needs to be conducted with these regulations considered. Other commenters
(135.1, 129.1) noted that SSIs are currently regulated under 40 CFR part 503, NSPS 40 CFR part
60 subpart O, the mercury and beryllium NESHAPS, and state permit requirements, and must
comply with site specific limits for arsenic, cadmium, chromium, lead, and nickel. One
commenter (129.1) requested that EPA adhere to the Part 503 program, stating that the Part 503
regulations are risk based and therefore protective of human health and the environment.
Another commenter (135.1) stated EPA should consider consolidation or vacating redundant
rules that complicate compliance, stated that these rules would no longer provide an additional
environmental benefit for regulated facilities. One commenter (51.1) specifically requested if
facilities would be subject to the proposed rule and 40 CFR 60, Subpart O following
promulgation, or if the proposed rules would replaced Subpart O.
Response: EPA disagrees that regulation of SSI units under section 129 is unnecessary
because SSI units are already regulated under section 405 of the CWA. As explained in section
VI of the preamble, the final rule will achieve reductions of the section 129 pollutants from SSI
units. Please see Section V.A of the preamble for a more complete discussion of these issues.
Comment: One commenter (129.1) stated that there are a number of POTWs that
practice incineration that are located in areas that are not in attainment with the Clean Air Act
requirements for particulate matter, ozone, oxides of nitrogen or sulfur dioxide. The commenter
(129.1) noted that these POTWS are required to limit the emissions of the pollutants and their
precursors, and expressed concern that the proposed rule would add an additional burden as these
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units would be subject to a significant number of differing Federal, State and local emission
limits.
Response: Section 129 of the CAA requires EPA to emission standards for SSI units.
Section 129 standards do not allow EPA to differentiate between sources in non-attainment and
attainment areas. However, we have tried to reduce the burden of complying with the final
standards by allowing less frequent testing and minimizing monitoring, recordkeeping and
reporting requirements, to what we believe to be necessary to assure compliance with the final
emission limits.
Comment: One commenter (134.1) specifically stated that the 503 regulations use total
hydrocarbons (THC) or carbon monoxide (CO) as a surrogate for complete combustion, whereas
the proposed regulations require both THC and CO continuous emission monitors for existing
multiple hearth SSIs. The commenter (134.1) requested that EPA resolve this conflict prior to
promulgation, and not after, as discussed in the preamble to the proposed rule.
Response: In the final rule, we are not incorporating the alternative THC compliance
requirement. Section 129 requires that limits be set for each of the 9 regulated pollutants.
Surrogates, such as THC, cannot be used in place of the regulated pollutants.
Comment: One commenter (97.1, 127.1) stated that under the Clean Water Act, POTWs
maintain the power to choose a residual management option that best meets the needs of the local
community. The commenter (97.1, 127.1) suggests that, likewise, EPA should use the authority
Congress granted under Section 112 of the CAA to regulate the remaining HAP in a way that
preserves incineration as a viable residuals management option.
Response: EPA thanks the commenter for their input. EPA is not requiring landfilling
and did not propose to require it in the NPRM. However, EPA did analyze the costs and impacts
of landfilling as an alternative option used for sludge disposal. We have revised our costs and
impacts of the landfill alternative based on comments received on the proposal and corrections
made to the analysis. A detailed discussion of the landfilling alternative analysis is provided in
the memorandum "Revised Cost and Emission Reduction of the MACT Floor Level of Control"
in the SSI docket (EPA-HQ-OAR-2009-0559). The revisions included storage, mileage, and cost
data provided by commenters. Based on the revised impacts (as discussed above), it is unlikely
that many sources will find landfilling an appropriate alternative. The selection of a management
option for sewage sludge is often a local decision that is based on environmental protection
concerns, community needs, geographic constraints, and economic conditions. Given a full
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evaluation of these factors, for some sources, landfilling or land treatment may be a better
management option than incineration.
EPA has also revised the final limits, and after revising the emissions data set and
associated default parameters based on data corrections submitted during the comment period,
EPA has revised its cost estimates for MACT and beyond-the-floor control options. Please refer
to the memoranda "Revised Cost and Emission Reduction of the MACT Floor Level of Control"
and "Revised Analysis of Beyond the Maximum Achievable Control Technology (MACT) Floor
Controls for Existing SSI Units" (EPA-HQ-OAR-2009-0559) for details). Consequently,
emission reduction estimates and cost-effectiveness were also re-evaluated for the MACT floor
and beyond-the-floor options. Additionally, EPA has re-evaluated the applicable control options
for each pollutant. Based on these results, EPA has decided not to go beyond-the-floor for any of
the pollutants.
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23.0 STATUTORY AND EXECUTIVE ORDER REVIEWS
Comment: One commenter (89.1) urged EPA to revise its Regulatory Impact Analysis
and resubmit this document to OMB for further review under Executive Order 12866, based
upon EPA's apparent miscalculation of certain costs critical to the Proposed Standards (e.g., cost
for SSIs to meet the Proposed Standards and cost of landfilling). The commenter (89.1) also
recommended EPA withdraw the Proposed Standards to fully consider the correct cost data.
Response: We have revised our costs and impacts to incorporate corrections to the SSI
database, corrections to the calculation methodology, and revisions to the controls costed for
sources to meet the final standards. We have also revised our costs and impacts of the landfill
alternative based on comments received on the proposal and corrections made to the analysis. A
detailed discussion of the landfilling alternative analysis is provided in the memorandum
"Revised Cost and Emission Reduction of the MACT Floor Level of Control" in the SSI docket
(EPA-HQ-OAR-2009-0559). The revisions included storage, mileage, and cost data provided by
commenters. Based on the revised impacts (as discussed above), it is unlikely that many sources
will find landfilling an appropriate alternative. The selection of a management option for sewage
sludge is often a local decision that is based on environmental protection concerns, community
needs, geographic constraints, and economic conditions. Given a full evaluation of these factors,
for some sources, landfilling or land treatment may be a better management option than
incineration.
Comment: One commenter (130.1) stated that EPA failed to assess the potential impacts
of SSI units on the nation's Tribes. The commenter (130.1) argued that apart from the anticipated
impact that the SSI Rule could have on Indian Tribes, EPA failed to adequately consult with
Tribes. The commenter (130.1) stated that in making a determination as to when consultation
with such Tribes is appropriate, the guiding principles for the Agency are encapsulated in
Executive Order (EO) 13175, Consultation and Coordination with Indian Tribal Governments.
The commenter (130.1) disagreed (based on its understanding of the EO) with EPA's finding
that the SSI Rule does not have Tribal implications as none of the nation's 218 SSI units are
owned by Tribes or located in Indian Country. The commenter (130.1) purported that EPA
assumed consultation with Tribes is only required when a federal action is expected to impose
substantial direct compliance costs on one or more Tribes. The commenter (130.1) stated that
this is a false presumption on the part of the EPA because any federal action having Tribal
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implications warrants consultation between the federal government and Tribes, particularly the
regulations being put forth as part of the Rule at hand. The commenter (130.1) argued that for the
EPA to limit its consultation with only those Indian Tribes owning SSI units or having SSI units
on Tribal lands ignores the large number of Tribes with potential exposures to the toxins from
emissions of SSI units such as mercury, lead, cadmium, hydrogen chloride, particulate matter,
carbon monoxide, dioxins/furans, nitrogen oxides, and sulfur dioxide. The commenter (130.1)
stated that these toxins can be carried into the atmosphere and transported great distances onto
Tribal land; the toxins can also enter waterways on which many Tribes depend for their cultural
and subsistence practices. The commenter (130.1) stated that fish, being one of the primary
subsistence foods for a number of these Tribes, are particularly at risk to mercury, a toxin known
to cause severe health risks to pregnant women. The commenter (130.1) argued that because of
this and the likelihood that some of these fish will be consumed by Tribal members, the Agency
must obligate itself to consult with Tribes based on this unique exposure pathway for toxins (e.g.,
through cultural and subsistence practices). The commenter (130.1) asserted that EPA has failed
to follow the edicts of both the EO and Agency's Indian Policy, and has therefore failed to fully
protect and preserve federal treaty trust resources important to Tribes such as hunting and fishing
rights, with such rights considered integral to many Tribes' continued existence. The commenter
(130.1) recommended EPA conduct meaningful consultation with the nation's Tribes regarding
the SSI Rule.
Response: During proposal EPA was not aware of any SSI owned or operated by an
Indian tribe or tribal governments, thus, Executive Order 13175 did not appear to have
implications. However as specified in Executive Order 13175, (65 FR 67249, November 9,
2000), EPA has attempted to outreach and discuss possible SSI implications with tribal contacts.
EPA presented information on the SSI proposal and specifically solicited additional comment on
the proposed action from tribal contacts in the proposal period via the NTAA conference calls.
EPA participated on two NTAA conference calls to discuss the rule development process, first to
provide general information on the development of the SSI standards and second providing more
specific background information on the purpose of the rulemaking, number and locations of
units, and unit types. EPA allowed time for clarifying questions and requested information if any
NTAA members were aware of any type of incinerator burning sewage sludge in Indian Country.
Comment: One commenter (130.1) requested EPA provide a better understanding as to
the actual location of these sites so the commenter can actively engage with the federal
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government and others to mitigate any and all adverse impacts that they may face from the toxins
contained at such sites. Using a memo dated June 2010 entitled "Development of the Inventory
Database for the Sewage Sludge Incinerator Source Category", the commenter (130.1) identified
SSI units in Alaska, Michigan, New York, Washington State and Wisconsin with potential
impacts from being sited near Tribal lands. The commenter (130.1) asserted that since these
facilities are near Tribal lands, Tribal members have the potential to incur exposure to SSI unit
emissions depending on many factors like meteorological conditions. The commenter (130.1)
recommended EPA needs to give its greatest attention to these tribes (those which are impacted
by off-reservation SSI unit emissions). The commenter (130.1) is concerned about how Tribes
are to know if the federal government's trust responsibility has been met in the context of the SSI
Rule when the Agency has failed to account for the impact of off-reservation SSI units on Tribal
lands such as transport of mercury emission into fishing habitats serving as cultural subsistence
sources for Tribes. The commenter (130.1) recommended that the Agency provide a map overlay
that accounts for both SSI units and Tribal lands so Tribes can acquire a better understanding on
how they might be affected by such sites and the Rule in general.
Response: EPA has attempted to outreach and discuss possible SSI implications with
tribal contacts. EPA presented information on the SSI proposal and specifically solicited
additional comment on the proposed action from tribal contacts in the proposal period via the
NTAA conference calls. EPA participated on two NTAA conference calls to discuss the rule
development process, first to provide general information on the development of the SSI
standards and second providing more specific background information on the purpose of the
rulemaking, number and locations of units, and unit types. EPA allowed time for clarifying
questions and requested information if any NTAA members were aware of any type of
incinerator burning sewage sludge in Indian Country. EPA will provide a map overlay for the
SSI docket so that tribes can acquire a better understanding on how they might be affected by
SSI sites and the standards in general.
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24.0 DURATION OF COMMENT PERIOD
Comment: Several commenters (65.1, 109.1, 138) requested more time to review the
proposed package. One commenter (65.1) stated that forty-five calendar days (review period:
October 14 through November 29) was not enough time to perform much more than a cursory
overview of the data, and needed more time to adequately review and comment in the data
presented. Another commenter (109.1) requested EPA allow a minimum of an additional 45 days
for the comment period stating that the source emission profiles of SSIs in POTWs are quite
complicated, and significantly vary by locality, equipment configurations, operating modes, and
sludge cake quality conditions. Another commenter (138) requested that EPA extend the public
comment period for an additional thirty (30) days beyond November 29th. One commenter (138)
said that the comment period's November 29th deadline is far too short for generating the
additional data and required analysis.
Response: Given the court-ordered deadline for EPA to issue the final SSI rule, it was
not possible to extend the comment period.
Comment: Some commenters (76.1, 83.1, 129.1) urged EPA to seek an extension of the
court order to promulgate emission standards by January 16, 2011. One commenter (76.1) stated
that serious procedural mistakes by EPA staff and major calculation errors in the technical
attachments has resulted in hundreds of comments on the draft rule as well as set the stage for
definite legal action. The commenter (76.1) is concerned that some significant deficiencies may
have been missed that will impair them from continuing to provide incineration as the most cost
effective means of sludge handling for the citizens they serve. The commenter (76.1) urged EPA
to not use this deadline to justify the use of insufficient emission data, flawed emission
calculations, and incorrect economic analysis in determining the MACT floor or beyond-the-
floor emissions limits. The commenter (76.1) also requested EPA provide another comment
period to allow the regulated community the opportunity to review a document that does not
have such a massive number of errors. Another commenter (83.1) requested an explanation if
EPA is not planning to seek such an extension. One commenter (129.1) argued that EPA should
request additional time from the Court to properly review and revise the proposed rule because
of the following reasons:
- Inaccurate assumptions made by EPA and its contractors in developing the proposed
rule and the resulting incorrect determinations,
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Lack of proper consideration of the variability of the composition of sewage sludge
from POTW to POTW and within a POTW from season to season and even week to
week,
Lack of a proper variability analysis on the limited amount of SSI air emissions test
data that was collected during the Information Collection Request,
Proposed new source performance standards that no new SSI will not be able to
continuously meet,
Sewage sludge is substantially different than the hospital, medical and infection
wastes on which the proposed rules are based and it is not homogeneous,
SSIs will not be able to continuously comply with the proposed operational standards
and a number of the other proposed requirements,
Major impacts that the proposed SSI rule will have on POTWs and their customers,
and
Lack of time (45-days) that the POTWs that practice incineration had to review this
very complex proposed rule and the voluminous back-up information contained
within the docket.
Response: EPA requested and received a 30-day extension to address public comments
in the final rule. As stated above, EPA is required by court order to issue these regulations by
Feb. 21, 2011. EPA has responded to the commenters concerns in the preamble to the final rule
and in this response to comments document.
Comment: At least one commenter (97.1, 127.1) stated that EPA's request for additional
stack test data is an inappropriate burden for sources at this stage of the rulemaking. The
commenter (97.1, 127.1) stated that EPA has primary responsibility for gathering the data. The
commenter (97.1, 127.1) stated that asking sources to provide additional stack test data during
the 45-day public comment period undermines the source's ability to comment on the proposed
options for regulation. Furthermore, the commenter (97.1, 127.1) asserts that EPA offered
insufficient time to conduct the stack tests, quality assure the data and submit it for
consideration.
Response: EPA's request for additional stack data was intended to encourage sources to
submit any existing data as well as any other relevant data and information they were able to
provide for the purpose of establishing these emissions standards. Such requests are commonly
made by EPA when it proposes regulations that rely on available information, and that request
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was not a requirement that sources test their SSIs. As summarized in sections 8.0 and 9.0 of this
document, many commenters compared EPA's emission estimates to results from their most
recent tests. While some commenters summarized their test data, no commenters provided any of
the test reports on which the data were based. Without the actual test reports, which are
necessary to extract information and verify tests were properly conducted using approved EPA
test methods and without problems, EPA was unable to use any of the test data summarized in
the comments.
Comment: Some commenters (97.1, 127.1, 111.1, 121.1, 128.1, 83.1) requested that
EPA withdraw or postpone the rulemaking until additional data could be gathered. One
commenter (111.1) specifically requested that EPA delay the rulemaking until two years after
EPA's rulemaking regarding amalgam separators becomes effective.
Response: EPA is ordered by the Court to satisfy its obligation under CAA section
112(c)(3) and (k)(3)(B)(ii) by February 21, 2011 (Sierra Club v. Jackson: D.D.C. No.
1:01CV0153).
Comment: One commenter (48.1) stated that they do not understand why the
approximately 150 municipalities to which this proposed rulemaking affects were not notified by
the Agency. The commenter (48.1) said they learned of this current (and final) opportunity to
comment on this action via a salesman who markets incineration emission control devices. To
get commentary from the entities this proposed rulemaking directly affects, the commenter
(48.1) recommended that effort be made by EPA to contact the regulated community. The
commenter (48.1) stated that the regulated community makes the necessary effort to contact EPA
at least annually to submit compliance reports.
Response: EPA began data collection efforts in 2009 for the SSI rulemaking, in which
EPA sent an ICR to affected sources. The industry trade group, NACWA, has been aware of
EPA's SSI rule and its schedule, and even suggested sources to be tested. Given the court-
ordered deadline for EPA to issue the final SSI rule, it was not possible to undertake the time-
consuming process of sending an ICR to all the affected SSI units consistent with the
requirements of the PRA.
Comment: One commenter (83.1) stated that EPA's rush to issue this rule has put
enormous and unwarranted pressure on the municipal wastewater industry to form an
understanding of the impacts of this rule and respond accordingly; the fact that we are still
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discovering potentially negative and costly impacts at the eleventh hour should be cause for
concern by EPA.
Response: EPA thanks the commenter for their input. EPA has made all efforts to
address public comments and concerns. Furthermore, we conducted one public hearing to allow
the public to comment on the proposed rulemaking. In response to these comments, EPA is has
revised the standards accordingly.
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25.0 ELECTRONIC DATA SUBMITTAL
Comment: At least two commenters (62.1, 76.1) stated that requiring submission of
reports via ERT database is burdensome, and confusing. One commenter (76.1) stated that the
existing ERT is very cumbersome and difficult to use, and should be updated with special
attention to the user interface. The commenter claimed that if EPA does not revise the ERT user
interface, many agencies will elect to not use electronic reporting and submit data on hardcopy.
Response: EPA thanks the commenters for their suggestions and feedback. As with any
new tool, it may take some practice before a new user will get familiar with the ERT. Since the
initial distribution of version 3-1 of the ERT there have been 26 revisions to address interface
and other issues identified by users. Additional improvements are planned for the product to
expand the product and to streamline data entry. The ERT contains fields for entering data that is
typically contained in a test report. It does not require any additional or superfluous reporting.
The ERT will allow EPA to collect data consistently from sources across the board. Also, EPA is
working with State and local agencies to ensure that reporting needs are met.
EPA believes that industry, regulatory agencies and the public benefit from electronic
data collection in that it increases the accessibility and transparency of these data, provides the
potential for reducing regulatory review resources and not increase resources for submitting the
data. In conducting performance test data for required reviews, EPA has found it ineffective and
time consuming, not only for us, but also for regulatory agencies and source owners and
operators to locate, collect, and submit emissions test data because of varied locations for data
storage and varied data storage methods. In this final rule, EPA is taking a step to improve data
accessibility and increase the ease and efficiency of reporting for sources. EPA has also worked
with industry sectors to answer questions and provide assistance in using the ERT.
The ERT was developed with input from stack testing companies who generally collect
and compile performance test data electronically and offices within state and local agencies that
perform field test assessments. The ERT is currently available at
http://www.epa.gov/ttn/chief/ert/ert_tool.html, and access to direct data submittal to EPA's
electronic emissions database (WebFIRE) will become available by December 31, 2011. On the
ERT website, there are numerous User Help documents including training guides and webinars
available.
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We believe industry will benefit from development of improved emission factors, fewer
follow-up information requests, and better regulation development as discussed below. One
major advantage of submitting source test data through the ERT is a standardized method to
compile and store much of the documentation required to be reported by this rule that also
clearly states what testing information would be required. Another important benefit of
submitting these data to EPA at the time the source test is conducted is that it should
substantially reduce the effort involved in data collection activities in the future. When EPA has
source category performance test data in hand, there will likely be fewer or less substantial data
collection requests in conjunction with prospective required residual risk assessments or
technology reviews. This results in a reduced burden on both affected facilities (in terms of
reduced manpower to respond to data collection requests) and EPA (in terms of preparing and
distributing data collection requests and assessing the results).
State/local/tribal agencies may also benefit in that their review may be more streamlined
and accurate because they would not have to re-enter the data to assess the calculations and
verify the data entry. Finally, another benefit of submitting these data to WebFIRE electronically
is that these data will greatly improve the overall quality of the existing and new emission factors
by supplementing the pool of emissions test data upon which the emission factor is based and by
ensuring that data are more representative of current industry operational procedures. In
summary, in addition to supporting regulation development, control strategy development, and
other air pollution control activities, receiving test data already collected and using them in the
emissions factors development program will save industry, state/local/tribal agencies, and EPA
significant time, money, and effort while improving the quality of emission inventories and
related regulatory decisions.
Comment: One commenter (76.1) recommended EPA upgrade the Electronic Reporting
Tool (ERT) into a spreadsheet format to eliminate the possibility of additional errors during data
transposition. The commenter (76.1) stated that the ICR survey, which incorporated the ERT,
was formatted as a questionnaire rather than a series of spreadsheets; the information reported
had to be transposed to a spreadsheet in order to be used effectively in a database. The
commenter (76.1) purported that the use of spreadsheets would have made the ICR experience
less cumbersome and could avoid errors in the processing of data transposition into the EPA
database.
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Response: EPA thanks the commenters for their suggestions and feedback. In developing
the ERT, we evaluated the use of spreadsheet applications and determined that this was
inefficient. We recognize that many source test contractors used their own field data spreadsheets
rather than the one we provide with the ERT to record data. While we provided directions to
copy field data from their field data spreadsheet into the ERT avoiding transcription errors, we
understand that a few users continued to have difficulties. In future updates of the ERT user
manual, we will include directions for modifying company specific spreadsheets to allow for
easier and more consistent importing field data. We will also evaluate and revise if necessary the
existing directions for manual importing of field data.
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26.0 STATUTORY BASIS FOR REGULATING SSIS UNDER SECTION
129 (E.G., VS. Ill)
Comment: Numerous commenters (83.1, 58, 61.1, 63.1, 67.1, 68.1, 69.1, 70.1, 71.1,
72.1, 73.1, 74.1, 78.1, 81.1, 83.1, 87.1, 89.1, 90.1, 93.1, 94.1, 96.1, 97.1, 127.1 101.1, 102.1,
103.1, 105.1, 106.1, 107.1, 109.1, 111.1, 112.1, 113.1, 114.1, 115.1, 116.1, 117.1, 118.1, 120.1,
126.1, 131.1, 132.1, 136.1, 138, 129.1) argued that SSIs are within the scope of the Clean Water
Act definition of POTWs; therefore, according to Section 112(e)(5) of the Clean Air Act, EPA
must regulate SSIs under Section 112(d), and not Section 129. Several of these commenters (58,
63.1, 67.1, 68.1, 69.1, 71.1, 74.1, 83.1, 87.1, 90.1, 90.1, 94.1, 97.1, 127.1, 103.1, 105.1, 109.1,
111.1, 112.1, 114.1, 115.1, 118.1, 120.1, 126.1, 138) stated that they (or others) have upgraded
or constructed their SSIs using Clean Water Act Construction Grant Funding. Many of these
commenters (58, 61.1, 63.1, 67.1, 68.1, 69.1, 70.1, 71.1, 72.1, 74.1, 81.1, 87.1, 90.1, 93.1, 101.1,
102.1, 103.1, 105.1, 106.1, 107.1, 109.1, 110.1, 110.1, 111.1, 112.1, 113.1, 114.1, 115.1, 116.1,
117.1, 118.1, 120.1, 126.1, 132.1, 136.1, 129.1) emphasized that their SSIs are located within
each respective POTW and are wholly integrated into the solids handling and treatment
processes at each respective POTW. Other commenter (97.1, 127.1) argued that all SSIs are
located within the boundaries of a POTW and nearly all are owned and operated by the
municipalities that own and operate the POTW. One commenter (120.1) is specifically
concerned that if SSIs become regulated under Section 129 of the Clean Air Act, a potential long
term impact could be an interpretation that they are not eligible for funding under the Clean
Water Fund Loan program because they are not regulated under Section 112(e) of the Clean Air
Act. Another commenter (138) stated that the preamble to the MACT rule provides no legal basis
for ignoring decades of EPA actions under the construction grants program that treated SSIs as
part of the POTW.
Response: Please refer to Section V.A. of the SSI preamble for the response to these
comments.
Comment: One commenter (120.1) is specifically concerned that if SSIs become
regulated under Section 129 of the Clean Air Act, a potential long term impact could be an
interpretation that they are not eligible for funding under the Clean Water Fund Loan program
because they are not regulated under Section 112(e) of the Clean Air Act. Another commenter
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(138) stated that the preamble to the MACT rule provides no legal basis for ignoring decades of
EPA actions under the construction grants program that treated SSIs as part of the POTW.
Response: The Clean Water Fund Loan program is outside the scope of this rulemaking.
Comment: Some commenters (83.1, 97.1, 127.1) stated that EPA resisted Section
112(e)(5) of the CAA in its Proposed Rule by arguing that it did not include SSI emission
standards in its 1999 POTW emissions rule because it intended to regulate SSIs as "other solid
waste incineration units" ("OSWI") under CAA Section 129. The commenters (83.1, 97.1, 127.1)
stated that EPA's statement is belied by the fact that it subsequently excluded SSIs from
regulation as OSWI, and stated specifically that it had "decided not to regulate SSI under the
OSWI rules. We are developing regulations for SSI under CAA section 112." One commenter
(97.1, 127.1) stated that in February 2002, EPA revised its list of source categories under §112 to
delete SSIs, not because they were not covered by §112, but because there were no major sources
in that category (See 67 Fed. Reg. 6521 (Feb. 12, 2002)). The commenters (97.1, 127.1) stated
that EPA then added SSIs to the list of area source categories under §§112(c) and 112(k) of the
CAA (See 67 Fed. Reg. 43112 (Jun. 26, 2002); and 67 Fed. Reg. 70427 (Nov. 22, 2002)).
One commenter (97.1, 127.1) argued that the legislative history of CAA §129 is silent to
both POTWs and SSIs, and no public health or environmental benefit will be realized from
including SSIs under CAA §129. The commenter (97.1, 127.1) argued that EPA has already
regulated SSIs as intended under CAA §112 by identifying SSIs as an area source category under
this section. The commenter (97.1, 127.1) stated that EPA examined the issue of the CAA
regulation of SSIs in 1992, when it issued its initial list of major and area source categories under
§112 (See 57 Fed. Reg. 31576 (July 16, 1992)). The commenter (97.1, 127.1) stated that the
initial list included SSIs as a §112 source category, and in this notice EPA expressly states "the
Agency does not consider sewage sludge incineration units to be covered under §129 so it has
authority to list and set standards for these units under §112." See also 58 Fed. Reg. 9248, 9262,
9276-77 (Feb. 19, 1993) (noting that SSIs are regulated under §112 of the CAA).
Commenters (83.1) argued that EPA's determination that it is bound by the NRDC case to
regulate SSIs at POTWs under Section 129 of the CAA is based upon an overly broad reading of
that case. The commenters (83.1) stated that they do not read the NRDC case as directly on point
with regard to this issue because the case does not make any holdings about the proper definition
of solid waste or regarding the proper regulation of SSIs that are a part of POTWs. Another
commenter (97.1, 127.1) stated that the court in the NRDC case did not address §112(e)(5), nor
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did it specifically address the regulation of POTWs or SSIs, so the decision in that case has no
bearing on how SSIs are to be regulated under the CAA.
Other commenters (73.1, 121.1, 97.1, 127.1) stated that EPA has the discretion and
authority to preserve the current framework for regulating sewage sludge under §405 of the
Clean Water Act and urged this authority be exercised. One commenter (73.1) stated that this
would retain the risk based approach and maintain the effective regulatory approach under 40
CFR part 503 and §112 oftheCAA. Another commenter (97.1, 127.1) stated that emissions from
SSIs are already regulated by other Congress!onally-mandated, comprehensive regulations that
are adequately protective of human health and the environment, and provided a detailed history
of this regulation including section 405(d) of the CWA and 40 CFR Part 503 standards.
Response: Please refer to the SSI preamble for the response to these comments.
Comment: One commenter (97.1, 127.1) said that EPA does not explain how it reached
the conclusion that SSIs are not covered by the expansive CWA definition of "treatment works"
incorporated into CAA §112(e)(5), how its interpretation is possible in light of the integral role
SSIs play in the management of sewage sludge, or how SSIs could have been built and improved
using CWA Title II funds if they are not part of the CWA definition of "treatment works."
Response: Please refer to the SSI preamble for the response to these comments.
Comment: One commenter (97.1, 127.1) contended that EPA fails to recognize its own
contrary statements and actions, stating that shortly after EPA promulgated the POTW NESHAP,
EPA reversed its position and expressly stated that SSIs would be regulated under §112 instead
of §129 (See Unified Agenda 65 Fed. Reg. 23459-01 (Apr. 24, 2000)).
Response: Please refer the SSI preamble for the response to these comments.
Comment: One commenter (97.1, 127.1) stated that EPA faces legal obstacles to using
§129 to regulate SSIs because they do not fit the statutory definition of "solid waste incineration
unit." Two commenters (138, 97.1, 127.1) stated that EPA cannot ignore the language in section
129(g)(l) in that POTW sewage sludge is not from a commercial or industrial establishment or
the general public. The commenters (138, 97.1, 127.1) contended that SSIs cannot be regulated
under §129 because they are combusting a material that is generated by the POTW, which is
neither a commercial or industrial establishment nor the general public. The commenter (138)
pointed out that, based on the proposed definition of solid waste, even if they had a new point of
generation within the POTW where they are generating solid waste, the POTW sewage sludge is
from a municipal source and does not pass the broad applicability for solid waste incineration
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under section 129. The commenter (97.1, 127.1) pointed out that Section 129(a)(l)(B)-(C) also
directs EPA to set standards for "solid waste incineration units [of specified sizes] combusting
municipal waste ... ." But to qualify as a unit combusting "municipal waste" the unit must first be
a "solid waste incineration unit," which does not include SSIs.
Response: Please refer to the SSI preamble for the response to these comments.
Comment: One commenter (101.1) stated that that EPA's Proposed Standards for SSIs,
as advanced under Section 129 of the CAA, are not rationally related to the goal of
environmental protection sought to be achieved; the Proposed Standards will result in the
expenditure of significant amounts of public funds at a time when such resources are in scarce
supply, and that the Proposed Standards, if adopted, would undermine the goals of the CAA.
Commenters (83.1) opposed the designation of sewage sludge as a solid waste because
subjecting incineration to much more costly Section 129 CAA mandates would effectively close
the door on incineration as a viable management option. Two commenters (102.1, 116.1) are
concerned that they will be impacted in extreme and adverse ways if sewage sludge is regulated
as a solid waste and SSIs are required to comply with the proposed Section 129 standards.
Response: EPA disagrees. First, EPA is required by section 129 of the CAA to issue
emissions standards for SSIs. Further, as explained in section VI of the preamble, the final rules
will achieve reductions of the section 129 pollutants from SSI units. We have revised the costs
and impacts in the final rule based on comments received on the proposal and corrections made
to the analysis. A detailed discussion of the analysis is provided in the memorandum "Revised
Cost and Emission Reduction of the MACT Floor Level of Control" in the SSI docket (EPA-
HQ-OAR-2009-0559).
Comment: One commenter (51.1) is concerned that 40 CFR Part 503 and Clean Water
Act requirements are insufficient to control variations in charged wastes (75 FR 63270). The
commenter (51.1) provided as an example a SSI unit at a WWTP that makes occasional requests
for approval to combust non-sewage sludge waste materials, without pretreatment, either
directly, or by blending with sewage sludge. The commenter (51.1) stated that these waste
materials, which may include food processing wastes, waste from biofuel recyclers, oil and
grease trap residues, and paper mill sludge, are not subject to the requirements of Part 503 as
they are often not treated at the WWTP prior to incineration.
Response: Section 129 defines solid waste incineration unit to include any unit
combusting any solid waste. Therefore, EPA is not setting de minimus levels for solid waste
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burned in incinerators. Any amount of sewage sludge combusted in an incinerator located at a
wastewater treatment facility designed to treat domestic sewage sludge is subject to the final SSI
standards. Section 129 of the CAA requires EPA to set emission standards for SSIs. The final
standards for SSI's provide assurance that emissions from any wastes combusted at SSI's, such
as the wastes listed by the commenter, will be controlled and reduced.
Comment: One commenter (89.1) stated that implementation of the Proposed Standards
would subject SSIs to potentially two sets of regulatory requirements, 40 CFRPart 503 and 40
CFR Part 60, which is contrary to Congressional intent.
Response: EPA notes that section 405 of the CWA expressly provides that nothing in
that section is intended to waive more stringent requirements of any other law. Therefore,
Congress clearly did not intend for regulation of SSI units under the CWA to preclude any other
regulations. Because both part 503 and these final standards cover the same universe of facilities,
there are certain issues that arise in terms of potential impacts to current SSI facilities. EPA plans
to evaluate the requirements under the CWA to determine what changes, if any, should be made
to the part 503 regulations.
Comment: One commenter (95.1) stated that Section 111 defines NSPS as a standard of
performance based on the "best system" of emission reduction achievable, taking into account
cost and any nonair quality health and environmental impact and energy requirements, that has
been "adequately demonstrated"; the analysis is commonly referred to as "BDT," or "best
demonstrated technology." The commenter (95.1) argued that EPA has not performed a BDT
analysis for setting NSPS. The commenter (95.1) argued that failing to perform the required
BDT analysis violates §111 as there is nothing in §129 that precludes the analysis required by
§111. The commenter (95.1) stated that both statutory provisions are compatible: both sections
require EPA to set "achievable" standards as section 129 merely provides a minimum level of
stringency resulting from the BDT analysis EPA is required to use. The commenter (95.1) stated
that EPA can still perform a BDT analysis and then check to see if the resulting standard meets
the level of stringency required by §129. The commenter (95.1) noted that EPA is not required to
establish floors first, and pointed out this was a process choice the Agency made a long time ago
when it set the medical waste incinerator MACT standards under §129 (See Sierra Club v. EPA,
167 F.3d. 658, 660 (D.C. Cir. 1999)). The commenter (95.1) stated that EPA could decide to first
determine what standards are "achievable" as NSPS and then check to see if these standards are
as stringent as the floor benchmarks for new and existing sources.
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Response: EPA disagrees that it must first look to section Ill's definition of "standard
of performance" in setting MACT standards under section 129. Section 129 specifically states
that standards "promulgated under section 111 and this section [i.e., section 129]" shall reflect
the maximum degree of reduction of emissions of the nine specified pollutants. Therefore,
regardless of the language of section 111, EPA's section 129 standards must reflect MACT
levels of reductions. As explained elsewhere in the docket for this rulemaking, EPA has
reasonably estimated the emissions of the best-performing sources to establish the MACT limits,
and the commenter provides no information to indicate that the MACT analysis would result in a
different outcome if EPA first performed an analysis to identify the "best" system of emissions
reductions as described in section 111.
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27.0 SOURCE REDUCTION (I.E., THE STRATEGY OF REDUCING
EMISSIONS AT THE UPSTREAM SOURCE)
Comment: One commenter (64.1) stated that EPA needs to strongly consider
achievements that could be realized through improved sludge quality in comparison to more
costly technology-based solutions. Several commenters (63.1, 82.1, 93.1, 97.1, 127.1, 114.1,
120.1, 129.1) supported mercury source reduction measures. Commenters (76.1, 121.1) stated
that EPA should adopt upstream control technologies and eliminate beyond-the floor
requirements, citing that upstream control is more efficient and cost effective than adding new
processes to the treatment plant or modifying the MHF. One commenter (49.1) stated that EPA
must evaluate and compare other proven means to reduce Hg emissions, including Hg source
elimination/reduction, Hg treatment at source, chemical precipitation of scrubber water, and high
efficiency scrubbers. Other commenters (82.1, 93.1, 135.1) stated that EPA should consider an
overall mercury reduction strategy with a primary goal of eliminating mercury from the waste
stream over a longer period of time than would be allowed by the proposed NSPS, and
secondarily use add on controls to remove mercury from SSI flue gas.
Commenters (49.1) state that the likely sources of mercury discharges would be dental
offices and industry, and notes that chemical treatment of dental and industrial wastes to reduce
mercury discharge into the sewer should be part of the cost evaluation and would be more cost-
effective than treating the incinerator off-gases. Commenters (82.1, 93.1) recommended
installation of amalgam separators at dental facilities and implementation of best management
practices at dental and other health care facilities to reduce the amount of mercury in the waste.
Commenters (64.1, 76.1, 97.1, 124.1, 127.1, 138) provided costs and results of regional
programs implemented by dentists to remove mercury through amalgam separator programs and
claimed that the pollution prevention initiative is far more efficient and cost effective than SSI
mercury controls. One commenter (64.1) stated that industrial pretreatment programs have
successfully reduced emissions of mercury and other contaminants from sewage sludge
incinerators in New Jersey. The commenter (64.1) further stated that new dental amalgram
regulations could result in an additional 40 to 55 pound reduction in the amount of mercury
being released. The commenter (64.1) estimated the total costs to comply with the proposed rule
could exceed $30 million for New Jersey's eight SSI, and that sludge metals standards that can be
achieved with pretreatment programs may be a better basis for a beyond the floor mercury limit
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than add on control. Another commenter (76.1) provided information regarding the success of a
local Household Hazardous Waste Program, which focuses on proper mercury disposal through
acceptance of mercury containing wastes including thermometers, fluorescent bulbs, mercury
switches, and elemental mercury. The commenter (76.1) stated that the annual operating cost for
the program is approximately $2.3 million dollars or $639/lb of Hg removed, and has lowered
the influent mercury concentrations by 70% in the past six years. One commenter (138) states
that the Metropolitan Council Environmental Services of Saint Paul, Minnesota implemented a
dental amalgam separator program with a fifty percent (50%) reduction in mercury in their
biosolids. The commenter (138) also stated that the Northeast Ohio Regional Sewer District is
implementing a dental amalgam separator program that will require a ninety-nine percent (99%)
removal. Another commenter (124.1) noted that in Rhode Island, there has been a significant
reduction (53.6%) in mercury in the influent to the treatment facilities since dentists have been
required to use amalgam separators, and similar reductions from a MWRA facility in
Massachusetts when dental amalgam separator requirements were implemented. One commenter
(138) provided information regarding a household hazardous waste facility supported by Central
Contra Costa Sanitary District. The commenter (138) describes the program, which focuses on
proper mercury disposal through acceptance of mercury-containing wastes, including
thermometers, fluorescent bulbs, mercury switches and elemental mercury; additionally, dentists
were required to install amalgam separators and document proper disposal. The commenter (138)
provides mercury reduction estimates for the program, stating that the program has collected
over 1,700 pounds of elemental mercury and lowered influent mercury concentrations by 70%.
The commenter (138) also provided annual operating costs for the program (~$2.3 million or
$24,000 per pound of mercury removed). Two commenters (85.1, 110.1) stated that the City of
Palo Alto implemented dental amalgam separator programs and saw mercury concentrations in
their influent decrease by 60%. Commenters (85.1) also described the Palo Alto programs for
mercury source control, including legislation that eliminated mercury in thermometers, certain
switches, and novelty items (Chapter 656, Statutes of 2001), dental amalgam separator programs
including training programs for dental office workers, and ongoing drop-off programs for
mercury-containing equipment including thermostats, thermometers, medical devices, switches,
reagents, and medicines containing mercury. The commenter (85.1) also provided estimates of
the cost effectiveness of beyond-the-floor mercury reductions associated with the Palo Alto
dental amalgam program of approximately $18 million per ton of mercury removed.
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Response: EPA thanks the commenter for their input. However, source reduction is
outside of the scope of this rulemaking. EPA is required by Section 129 of the Clean Air Act to
issue emission standards for SSI's.
Comment: Two commenters (107.1, 138) agreed with EPA's intentions to propose a rule
which will require the installation amalgam separators in dental offices to capture a minimum of
ninety-five percent (95%) of the mercury. One commenter (107.1) stated that mercury emission
from SSIs may be significantly reduced by EPA-mandated control of mercury discharge from
dental clinics.
At least three commenters (111.1, 117.1, 131.1) stated that EPA is premature in
proposing the rule at this time, noting that EPA intends to issue a ruling that will require dentists
to install dental amalgam separators to reduce mercury emissions; the commenters (111.1, 117.1)
argued that since mercury loadings to POTWs will soon be reduced due to the new ruling, it
would be best to wait for the results of that rulemaking to be measured before determining the
quantity of mercury emissions from POTWs. One commenter (75.1) stated that sludge mercury
concentrations will likely not be an issue when EPA-mandated controls for dental clinics are
fully implemented. Another commenter (135.1) stated that it is reasonable to assume that
mercury concentration in sewage sludge will continue to decline over time as mercury becomes
less prevalent in the state, and residual deposits of mercury gradually attenuate upstream from
and within wastewater collection systems. One commenter (117.1) also stated that mercury put
in sewer pipe upstream from a treatment facility may never reach the POTW due to a variety of
conditions in the collection system, and therefore, it is best to remove the pollutant at the
beginning of the pipe.
Response: EPA thanks the commenters for their input. However, source reduction is
outside of the scope of this rulemaking. EPA is required by Section 129 of the Clean Air Act to
issue emission standards for SSI's.
Comment: One commenter (124.1) expressed concern that EPA is not requiring sewage
sludge incinerators to establish a Waste Management Plan, specifically a Mercury
Control/Reduction Plan that would, at a minimum, require that dentists use amalgam separators.
The commenter (124.1) stated that implementation of Waste Management Plans or Mercury
Reduction Plans is vital for reducing mercury in sludge. The commenter (124.1) suggested that if
a municipality or state has amalgam separator requirements that have substantially lowered the
mercury content in the sludge, the rule should allow for the ability to establish compliance
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schedules for the installation of MACT control systems beyond the proposed 12 months. The
commenter (124.1) suggested that where facilities have already achieved substantial reductions,
the rule should allow up to an additional 12 -24 months for MACT compliance.
Response: EPA thanks the commenter for their input. However, source reduction is
outside of the scope of this rulemaking. EPA is required by Section 129 of the Clean Air Act to
issue emission standards for SSI's. The waste management plan for Section 129 sources would
apply only to SSI units and not the source generating the pollutant. We have determined that SSI
units are already complying with OW's 503 standards. In order to meet the 503 standards,
facilities are already incorporating management practices and measures to reduce waste and limit
the concentration of pollutants in the sludge sent to SSI units, such as segregating contaminated
and uncontaminated wastes and establishing discharge limits or pre-treatment standards for non-
domestic users discharging wastewater to POTW.
Comment: Commenters (64.1) were of the opinion that an effective pretreatment
program would be an appropriate floor, or beyond the floor, control measure for mercury. One
commenter (85.1) stated national source control is a more desirable and cost effective to achieve
beyond-the-floor mercury reductions for SSIs. The commenter (85.1) asserted that only source
control can truly prevent environmental release of mercury, and expressed concern that the wet
scrubbing in EPA's control strategy analysis would simply transfer airborne mercury to the water
stream. The commenter (85.1) also stated that attempting to take mercury to a landfill could
result in volatilization and release. At least two commenters (85.1, 110.1) contended that EPA
should duplicate their effort of using mercury source control for hazardous waste incinerators
(EPA Docket HQ-OAR-2004-0022) in their beyond-the-floor mercury control for SSIs. One
commenter (85.1) stated that EPA should estimate the mercury level that can be achieved in
sewage sludge incinerator stack gas after implementation of full source control. The commenter
(85.1) assumed that once amalgam separators are in place at dental offices nationwide, a 60 %
reduction in baseline mercury emissions from SSIs can be expected. Another commenter
provided (134.1) additional support and statistics for amalgam separators and added "We
disagree with the mercury BTF MACT limit analysis and believe it is will overestimate the level
of mercury reductions achievable by additional air pollution control measures on SSIs by failing
to recognize certain key developments in the area of mercury reductions from dental amalgams."
At least one commenter (108.1) stated that EPA ignored upcoming dental amalgam regulations.
Another commenter (134.1) stated that while they would not recommend including these as
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mandatory elements of the proposed regulations, there should be some consideration given to
designating mercury source control as the most appropriate and effective technique for reducing
mercury emissions from SSI units and, hence MACT for mercury control.
Response: EPA thanks the commenters for their input. However, source reduction is
outside of the scope of this rulemaking.
Comment: One commenter (135.1) provided a list of Connecticut statues established
under the Mercury Reduction and Education Act (P. A. 02-90). The commenter (135.1) stated
that the initiatives and statutory requirements aided in the noticeable reduction of the total
quantity of mercury discharged into municipal wastewater streams throughout Connecticut. The
commenter (135.1) reiterated that removing mercury from the environment would be a more
favorable goal then transferring mercury from one media (air) to another (solid waste) as would
result from the addition of air quality controls system for mercury removal. The commenter
(135.1) suggested further investigation into the sources of mercury found in wastewater
treatment plant sludge nationwide, followed by an elimination effort.
Response: EPA thanks the commenter for their input. However, source reduction is
outside of the scope of this rulemaking.
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