[Federal Register Volume 70, Number 196 (Wednesday, October 12, 2005)]
[Rules and Regulations]
[Pages 59402-59579]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-18824]



[[Page 59401]]

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Part II





Environmental Protection Agency





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40 CFR Parts 9, 63, 260 et al.



National Emission Standards for Hazardous Air Pollutants: Final 
Standards for Hazardous Air Pollutants for Hazardous Waste Combustors 
(Phase I Final Replacement Standards and Phase II); Final Rule

Federal Register / Vol. 70, No. 196 / Wednesday, October 12, 2005 / 
Rules and Regulations

[[Page 59402]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 9, 63, 260, 264, 265, 266, 270 and 271

[FRL-7971-8]
RIN 2050-AE01


National Emission Standards for Hazardous Air Pollutants: Final 
Standards for Hazardous Air Pollutants for Hazardous Waste Combustors 
(Phase I Final Replacement Standards and Phase II)

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This action finalizes national emission standards (NESHAP) for 
hazardous air pollutants for hazardous waste combustors (HWCs): 
hazardous waste burning incinerators, cement kilns, lightweight 
aggregate kilns, industrial/commercial/institutional boilers and 
process heaters, and hydrochloric acid production furnaces. EPA has 
identified HWCs as major sources of hazardous air pollutant (HAP) 
emissions. These standards implement section 112(d) of the Clean Air 
Act (CAA) by requiring hazardous waste combustors to meet HAP emission 
standards reflecting the performance of the maximum achievable control 
technology (MACT).
    The HAP emitted by HWCs include arsenic, beryllium, cadmium, 
chromium, dioxins and furans, hydrogen chloride and chlorine gas, lead, 
manganese, and mercury. Exposure to these substances has been 
demonstrated to cause adverse health effects such as irritation to the 
lung, skin, and mucus membranes, effects on the central nervous system, 
kidney damage, and cancer. The adverse health effects associated with 
exposure to these specific HAP are further described in the preamble. 
For many HAP, these findings have only been shown with concentrations 
higher than those typically in the ambient air.
    This action also presents our decision regarding the February 28, 
2002 petition for rulemaking submitted by the Cement Kiln Recycling 
Coalition, relating to EPA's implementation of the so-called omnibus 
permitting authority under section 3005(c) of the Resource Conservation 
and Recovery Act (RCRA). That section requires that each permit issued 
under RCRA contain such terms and conditions as permit writers 
determine to be necessary to protect human health and the environment. 
In that petition, the Cement Kiln Recycling Coalition requested that we 
repeal the existing site-specific risk assessment policy and technical 
guidance for hazardous waste combustors and that we promulgate the 
policy and guidance as rules in accordance with the Administrative 
Procedure Act if we continue to believe that site-specific risk 
assessments may be necessary.

DATES: The final rule is effective December 12, 2005. The incorporation 
by reference of Method 0023A into Sec.  63.14 is approved by the 
Director of the Federal Register as of December 12, 2005.

ADDRESSES: The official public docket is the collection of materials 
that is available for public viewing at the Office of Air and Radiation 
Docket and Information Center (Air Docket) in the EPA Docket Center, 
Room B-102, 1301 Constitution Ave., NW., Washington, DC.

FOR FURTHER INFORMATION CONTACT: For more information concerning 
applicability and rule determinations, contact your State or local 
representative or appropriate EPA Regional Office representative. For 
information concerning rule development, contact Michael Galbraith, 
Waste Treatment Branch, Hazardous Waste Minimization and Management 
Division, (5302W), U.S. EPA, 1200 Pennsylvania Avenue, NW., Washington 
DC 20460, telephone number (703) 605-0567, fax number (703) 308-8433, 
electronic mail address <a href="/cdn-cgi/l/email-protection#bddadcd1dfcfdcd4c9d593d0d4ded5dcd8d1fdd8cddc93dad2cb"><span class="__cf_email__" data-cfemail="c9aea8a5abbba8a0bda1e7a4a0aaa1a8aca589acb9a8e7aea6bf">[email protected]</span></a>.

SUPPLEMENTARY INFORMATION: 

Regulated Entities

    The promulgation of the final rule would affect the following North 
American Industrial Classification System (NAICS) and Standard 
Industrial Classification (SIC) codes:

----------------------------------------------------------------------------------------------------------------
                                                                                      Examples of potentially
               Category                           NAICS code             SIC code        regulated entities
----------------------------------------------------------------------------------------------------------------
Any industry that combusts hazardous
 waste as defined in the final rule.
                                       562211                                4953  Incinerator, hazardous waste
                                       327310                                3241  Cement manufacturing, clinker
                                                                                    production
                                       327992                                3295  Ground or treated mineral and
                                                                                    earth manufacturing
                                       325                                     28  Chemical Manufacturers
                                       324                                     29  Petroleum Refiners
                                       331                                     33  Primary Aluminum
                                       333                                     38  Photographic equipment and
                                                                                    supplies
                                       488, 561, 562                           49  Sanitary Services, N.E.C.
                                       421                                     50  Scrap and waste materials
                                       422                                     51  Chemical and Allied Products,
                                                                                    N.E.C
                                       512, 541, 561, 812                      73  Business Services, N.E.C.
                                       512, 514, 541, 711                      89  Services, N.E.C.
                                       924                                     95  Air, Water and Solid Waste
                                                                                    Management
----------------------------------------------------------------------------------------------------------------

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be regulated by this 
action. This table lists examples of the types of entities EPA is now 
aware could potentially be regulated by this action. Other types of 
entities not listed could also be affected. To determine whether your 
facility, company, business, organization, etc., is regulated by this 
action, you should examine the applicability criteria in Part II of 
this preamble. If you have any questions regarding the applicability of 
this action to a particular entity, consult the person listed in the 
preceding FOR FURTHER INFORMATION CONTACT section.

Abbreviations and Acronyms Used in This Document

acfm actual cubic feet per minute
Btu British thermal units
CAA Clean Air Act
CFR Code of Federal Regulations
DRE destruction and removal efficiency
dscf dry standard cubic foot
dscm dry standard cubic meter

[[Page 59403]]

EPA Environmental Protection Agency
FR Federal Register
gr/dscf grains per dry standard cubic foot
HAP hazardous air pollutant(s)
ICR Information Collection Request
kg/hr kilograms per hour
kW-hour kilo Watt hour
MACT Maximum Achievable Control Technology
mg/dscm milligrams per dry standard cubic meter
MMBtu million British thermal unit
ng/dscm nanograms per dry standard cubic meter
NESHAP national emission standards for HAP
ng nanograms
POHC principal organic hazardous constituent
ppmv parts per million by volume
ppmw parts per million by weight
Pub. L. Public Law
RCRA Resource Conservation and Recovery Act
SRE system removal efficiency
TEQ toxicity equivalence
[mu]g/dscm micrograms per dry standard cubic meter
U.S.C. United States Code

Table of Contents

Part One: Background and Summary
I. What Is the Statutory Authority for this Standard?
II. What Is the Regulatory Development Background of the Source 
Categories in the Final Rule?
    A. Phase I Source Categories
    B. Phase II Source Categories
III. How Was the Final Rule Developed?
IV. What Is the Relationship Between the Final Rule and Other MACT 
Combustion Rules?
V. What Are the Health Effects Associated with Pollutants Emitted by 
Hazardous Waste Combustors?
Part Two: Summary of the Final Rule
I. What Source Categories and Subcategories Are Affected by the 
Final Rule?
II. What Are the Affected Sources and Emission Points?
III. What Pollutants Are Emitted and Controlled?
IV. Does the Final Rule Apply to Me?
V. What Are the Emission Limitations?
VI. What Are the Testing and Initial Compliance Requirements?
    A. Compliance Dates
    B. Testing Requirements
    C. Initial Compliance Requirements
VII. What Are the Continuous Compliance Requirements?
VIII. What Are the Notification, Recordkeeping, and Reporting 
Requirements?
IX. What Is the Health-Based Compliance Alternative for Total 
Chlorine, and How Do I Demonstrate Eligibility?
    A. Overview
    B. HCl-Equivalent Emission Rates
    C. Eligibility Demonstration
    D. Assurance that the 1-Hour HCl-Equivalent Emission Rate Will 
Not Be Exceeded
    E. Review and Approval of Eligibility Demonstrations
    F. Testing Requirements
    G. Monitoring Requirements
    H. Relationship Among Emission Rates, Emission Rate Limits, and 
Feedrate Limits
    I. Changes
X. Overview on Floor Methodologies
Part Three: What Are the Major Changes Since Proposal?
I. Database
    A. Hazardous Burning Incinerators
    B. Hazardous Waste Cement Kilns
    C. Hazardous Waste Lightweight Aggregate Kilns
    D. Liquid Fuel Boilers
    E. HCl Production Furnaces
    F. Total Chlorine Emissions Data Below 20 ppmv
II. Emission Limits
    A. Incinerators
    B. Hazardous Waste Burning Cement Kilns
    C. Hazardous Waste Burning Lightweight Aggregate Kilns
    D. Solid Fuel Boilers
    E. Liquid Fuel Boilers
    F. Hydrochloric Acid Production Furnaces
    G. Dioxin/Furan Testing for Sources Not Subject to a Numerical 
Standard
III. Statistics and Variability
    A. Using Statistical Imputation to Address Variability of 
Nondetect Values
    B. Degrees of Freedom when Imputing a Standard Deviation Using 
the Universal Variability Factor for Particulate Matter Controlled 
by a Fabric Filter
IV. Compliance Assurance for Fabric Filters, Electrostatic 
Precipitators, and Ionizing Wet Scrubbers
V. Health-Based Compliance Alternative for Total Chlorine
Part Four: What Are the Responses to Major Comments?
I. Database
    A. Revisions to the EPA's Hazardous Waste Combustor Data Base
    B. Use of Data from Recently Upgraded Sources
    C. Correction of Total Chlorine Data to Address Potential Bias 
in Stack Measurement Method
    D. Mercury Data for Cement Kilns
    E. Mercury Data for Lightweight Aggregate Kilns
    F. Incinerator Database
II. Affected Sources
    A. Area Source Boilers and Hydrochloric Acid Production Furnaces
    B. Boilers Eligible for the RCRA Low Risk Waste Exemption
    C. Mobile Incinerators
III. Floor Approaches
    A. Variability
    B. SRE/Feed Methdology
    C. Air Pollution Control Technology Methodologies for the 
Particulate Matter Standard and for the Total Chlorine Standard for 
Hydrochloric Acid Production Furnaces
    D. Format of Standards
    E. Standards Can Be No Less Stringent Than the Interim Standards
    F. How Can EPA's Approach to Assessing Variability and its 
Ranking Methodologies be Reasonable when they Result in Standards 
Higher than the Interim Standards?
IV. Use of Surrogates
    A. Particulate Matter as Surrogate for Metal HAP
    B. Carbon Monoxide/Hydrocarbons and DRE as Surrogates for 
Dioxin/Furan
    C. Use of Carbon Monoxide and Total Hydrocarbons as Surrogate 
for Non-Dioxin Organic HAP
V. Additional Issues Relating to Variability and Statistics
    A. Data Sets Containing Nondetects
    B. Using Statistical Imputation to Address Variability of 
Nondetect Values
    C. Analysis of Variance Procedures to Assess Subcategorization
VI. Emission Standards
    A. Incinerators
    B. Cement Kilns
    C. Lightweight Aggregate Kilns
    D. Liquid Fuel Boilers
    E. General
VII. Health-Based Compliance Alternative for Total Chlorine
    A. Authority for Health-Based Compliance Alternatives
    B. Implementation of the Health-Based Standards
    C. National Health-Based Standards for Cement Kilns.
VIII. Implementation and Compliance
    A. Compliance Assurance Issues for both Fabric Filters and 
Electrostatic Precipitators (and Ionizing Wet Scrubbers)
    B. Compliance Assurance Issues for Fabric Filters
    C. Compliance Issues for Electrostatic Precipitators and 
Ionizing Wet Scrubbers
    D. Fugitive Emissions
    E. Notification of Intent to Comply and Compliance Progress 
Report
    F. Startup, Shutdown, and Malfunction Plan
    G. Public Notice of Test Plans
    H. Using Method 23 Instead of Method 0023A
    I. Extrapolating Feedrate Limits for Compliance with the Liquid 
Fuel Boiler Mercury and Semivolatile Metal Standards
    J. Temporary Compliance with Alternative, Otherwise Applicable 
MACT Standards
    K. Periodic DRE Testing and Limits on Minimum Combustion Chamber 
Temperature for Cement Kilns
    L. One Time Dioxin and Furan Test for Sources Not Subject to a 
Numerical Limit for Dioxin and Furan
    M. Miscellaneous Compliance Issues
IX. Site-Specific Risk Assessment under RCRA
    A. What Is the Site-Specific Risk Assessment Policy?
    B. Why Might SSRAs Continue To Be Necessary for Sources 
Complying With Phase 1 Replacement Standards and Phase 2 Standards?
    C. What Changes Are EPA Finalizing With Respect To the Site-
Specific Risk Assessment Policy?
    D. How Will the New SSRA Regulatory Provisions Work?
    E. What Were Commenters' Reactions to EPA's Proposed Decision 
Not to Provide National Criteria for Determining When an SSRA Is or 
Is Not Necessary?

[[Page 59404]]

    F. What Are EPA's Responses to the Cement Kiln Recycling 
Coalition's Comments on the Proposal and What is EPA's Final 
Decision on CKRC's Petition?
X. Permitting
    A. What is the Statutory Authority for the RCRA Requirements 
Discussed in this Section?
    B. Did Commenters Express any Concerns Regarding the Current 
Permitting Requirements?
    C. Are There Any Changes to the Proposed Class 1 Permit 
Modification Procedure?
    D. What Permitting Approach Is EPA Finalizing for New Units?
    E. What Other Permitting Requirements Were Discussed In the 
Proposal?
Part Five: What Are the CAA Delegation Clarifications and RCRA State 
Authorization Requirements?
I. Authority for this Rule.
II. CAA Delegation Authority.
III. Clarifications to CAA Delegation Provisions for Subpart EEE.
    A. Alternatives to Requirements.
    B. Alternatives to Test Methods.
    C. Alternatives to Monitoring.
    D. Alternatives to Recordkeeping and Reporting.
    E. Other Delegation Provisions
IV. RCRA State Authorization and Amendments To the RCRA Regulations.
Part Six: Impacts of the Final Rule
I. What Are the Air Impacts?
II. What Are the Water and Solid Waste Impacts?
III. What Are the Energy Impacts?
IV. What Are the Control Costs?
V. What Are the Economic Impacts?
    A. Market Exit Estimates
    B. Waste Reallocations
VI. What Are the Social Costs and Benefits of the Final Rule?
    A. Combustion Market Overview
    B. Baseline Specification
    C. Analytical Methodology and Findings--Social Cost Analysis
    D. Analytical Methodology and Findings--Benefits Assessment
Part Seven: How Does the Final Rule Meet the RCRA Protectiveness 
Mandate?
I. Background
II. Evaluation of Protectiveness
Part Eight: Statutory and Executive Order Reviews
I. Executive Order 12866: Regulatory Planning and Review
II. Paperwork Reduction Act
III. Regulatory Flexibility Act
IV. Unfunded Mandates Reform Act of 1995
V. Executive Order 13132: Federalism
VI. Executive Order 13175: Consultation and Coordination with Indian 
Tribal Governments
VII. Executive Order 13045: Protection of Children from 
Environmental Health Risks and Safety Risks
VIII. Executive Order 13211: Actions Concerning Regulations that 
Significantly Affect Energy Supply, Distribution, or Use
IX. National Technology Transfer and Advancement Act
X. Executive Order 12898: Federal Actions to Address Environmental 
Justice in Minority Populations and Low-Income Populations
XI. Congressional Review

Part One: Background and Summary

I. What Is the Statutory Authority for This Standard?

    Section 112 of the Clean Air Act requires that the EPA promulgate 
regulations requiring the control of HAP emissions from major and 
certain area sources. The control of HAP is achieved through 
promulgation of emission standards under sections 112(d) and (in a 
second round of standard setting) (f).
    EPA's initial list of categories of major and area sources of HAP 
selected for regulation in accordance with section 112(c) of the Act 
was published in the Federal Register on July 16, 1992 (57 FR 31576). 
Hazardous waste incinerators, Portland cement plants, clay products 
manufacturing (including lightweight aggregate kilns), industrial/
commercial/institutional boilers and process heaters, and hydrochloric 
acid production furnaces are among the listed 174 categories of 
sources. The listing was based on the Administrator's determination 
that these sources may reasonably be anticipated to emit one or more of 
the 186 listed HAP in quantities sufficient to designate them as major 
sources.

II. What Is the Regulatory Development Background of the Source 
Categories in the Final Rule?

    Today's notice finalizes standards for controlling emissions of HAP 
from hazardous waste combustors: incinerators, cement kilns, 
lightweight aggregate kilns, boilers, process heaters \1\, and 
hydrochloric acid production furnaces that burn hazardous waste. We 
call incinerators, cement kilns, and lightweight aggregate kilns Phase 
I sources because we have already promulgated standards for those 
source categories. We call boilers and hydrochloric acid production 
furnaces Phase II sources because we intended to promulgate MACT 
standards for those source categories after promulgating MACT standards 
for Phase I sources. The regulatory background of Phase I and Phase II 
source categories is discussed below.
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    \1\ A process heater meets the RCRA definition of a boiler. 
Therefore, process heaters that burn hazardous wastes are covered 
under subpart EEE as boilers, and are discussed as such in 
subsequent parts of the preamble.
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A. Phase I Source Categories

    Phase I combustor sources are regulated under the Resource 
Conservation and Recovery Act (RCRA), which establishes a ``cradle-to-
grave'' regulatory structure overseeing the safe treatment, storage, 
and disposal of hazardous waste. We issued RCRA rules to control air 
emissions from hazardous waste burning incinerators in 1981, 40 CFR 
Parts 264 and 265, Subpart O, and from cement kilns and lightweight 
aggregate kilns that burn hazardous waste in 1991, 40 CFR Part 266, 
Subpart H. These rules rely generally on risk-based standards to assure 
control necessary to protect human health and the environment, the 
applicable RCRA standard. See RCRA section 3004 (a) and (q).
    The Phase I source categories also are subject to standards under 
the Clean Air Act. We promulgated standards for Phase I sources on 
September 30, 1999 (64 FR 52828). This final rule is referred to in 
this preamble as the Phase I rule or 1999 final rule. These emission 
standards created a technology-based national cap for hazardous air 
pollutant emissions from the combustion of hazardous waste in these 
devices. The rule regulates emissions of numerous hazardous air 
pollutants: dioxin/furans, other toxic organics (through surrogates), 
mercury, other toxic metals (both directly and through a surrogate), 
and hydrogen chloride and chlorine gas. Where necessary, Section 
3005(c)(3) of RCRA provides the authority to impose additional 
conditions on a source-by-source basis in a RCRA permit if necessary to 
protect human health and the environment.
    A number of parties, representing interests of both industrial 
sources and of the environmental community, sought judicial review of 
the Phase I rule. On July 24, 2001, the United States Court of Appeals 
for the District of Columbia Circuit granted portions of the Sierra 
Club's petition for review and vacated the challenged portions of the 
standards. Cement Kiln Recycling Coalition v. EPA, 255 F. 3d 855 (D.C. 
Cir. 2001). The court held that EPA had not demonstrated that its 
calculation of MACT floors met the statutory requirement of being no 
less stringent than (1) the average emission limitation achieved by the 
best performing 12 percent of existing sources and, for new sources, 
(2) the emission control achieved in practice by the best controlled 
similar source for new sources. 255 F.3d at 861, 865-66. As a remedy, 
the court, after declining to rule on most of the issues presented in 
the industry petitions for review, vacated the ``challenged 
regulations,'' stating that: ``[W]e have chosen not to reach the bulk 
of industry petitioners' claims, and leaving the regulations in place 
during remand would ignore petitioners' potentially meritorious 
challenges.'' Id.

[[Page 59405]]

at 872. Examples of the specific challenges the Court indicated might 
have merit were provisions relating to compliance during start up/shut 
down and malfunction events, including emergency safety vent openings, 
the dioxin/furan standard for lightweight aggregate kilns, and the 
semivolatile metal standard for cement kilns. Id. However, the Court 
stated, ``[b]ecause this decision leaves EPA without standards 
regulating [hazardous waste combustor] emissions, EPA (or any of the 
parties to this proceeding) may file a motion to delay issuance of the 
mandate to request either that the current standards remain in place or 
that EPA be allowed reasonable time to develop interim standards.'' Id.
    Acting on this invitation, all parties moved the Court jointly to 
stay the issuance of its mandate for four months to allow EPA time to 
develop interim standards, which would replace the vacated standards 
temporarily, until final standards consistent with the Court's mandate 
are promulgated. The interim standards were published on February 13, 
2002 (67 FR 6792). EPA did not justify or characterize these standards 
as conforming to MACT, but rather as an interim measure to prevent 
adverse consequences that would result from the regulatory gap 
resulting from no standards being in place. Id. at 6793, 6795-96; see 
also 69 FR at 21217 (April 20, 2004). EPA also entered into a 
settlement agreement, enforceable by the Court of Appeals, to issue 
final standard conforming to the Court's mandate by June 14, 2005. That 
date has since been extended to September 14, 2005.

B. Phase II Source Categories

    Phase II combustors--boilers and hydrochloric acid production 
furnaces--are also regulated under the Resource Conservation and 
Recovery Act (RCRA) pursuant to 40 CFR Part 266, Subpart H, and (for 
reasons discussed below) are also subject to the MACT standard setting 
process in section 112(d) of the CAA. We delayed promulgating MACT 
standards for these source categories pending reevaluation of the MACT 
standard-setting methodology following the Court's decision to vacate 
the standards for the Phase I source categories. We also have entered 
into a judicially enforceable consent decree with Sierra Club that 
requires EPA to promulgate MACT standards for the Phase II sources by 
June 14, 2005, since extended to September 14, 2005--the same date that 
(for independent reasons) is required for the replacement standards for 
Phase I sources.

III. How Was the Final Rule Developed?

    We proposed standards for HWCs on April 20, 2004 (69 FR 21197). The 
public comment period closed on July 6, 2004. In addition, on February 
4, 2005, we requested certain key commenters to comment by email on a 
limited number of issues arising from public comments on the proposed 
rule. The comment period for those issues closed on March 7, 2005.
    We received approximately 100 public comment letters on the 
proposed rule and the subsequent direct request for comments. Comments 
were submitted by owner/operators of HWCs, trade associations, state 
regulatory agencies and their representatives, and environmental 
groups. Today's final rule reflects our consideration of all of the 
comments and additional information we received. Major public comments 
on the proposed rule along with our responses, are summarized in this 
preamble.

IV. What Is the Relationship Between the Final Rule and Other MACT 
Combustion Rules?

    The amendments to the Subpart EEE, Part 63, standards for hazardous 
waste combustors apply to the source categories that are currently 
subject to that subpart--incinerators, cement kilns, and lightweight 
aggregate kilns that burn hazardous waste. Today's final rule, however, 
also amends Subpart EEE to establish MACT standards for the Phase II 
source categories--those boilers and hydrochloric acid production 
furnaces that burn hazardous waste.
    Generally speaking, you are an affected source pursuant to Subpart 
EEE if you combust, or have previously combusted, hazardous waste in an 
incinerator, cement kiln, lightweight aggregate kiln, boiler, or 
hydrochloric acid production furnace. You continue to be an affected 
source until you cease burning hazardous waste and initiate closure 
requirements pursuant to RCRA. Affected sources do not include: (1) 
Sources exempt from regulation under 40 CFR part 266, subpart H, 
because the only hazardous waste they burn is listed under 40 CFR 
266.100(c); (2) research, development, and demonstration sources exempt 
under Sec.  63.1200(b); and (3) boilers exempt from regulation under 40 
CFR part 266, subpart H, because they meet the definition of small 
quantity burner under 40 CFR 266.108. See Sec.  63.1200(b).
    If you never previously combusted hazardous waste, or have ceased 
burning hazardous waste and initiated RCRA closure requirements, you 
are not subject to Subpart EEE. Rather, EPA has promulgated separate 
MACT standards for sources that do not burn hazardous waste within the 
following source categories: commercial and industrial solid waste 
incinerators (40 CFR Part 60, Subparts CCCC and DDDD); Portland cement 
manufacturing facilities (40 CFR Part 63, Subpart LLL); industrial/
commercial/institutional boilers and process heaters (40 CFR Part 63, 
Subpart DDDDD); and hydrochloric acid production facilities (40 CFR 
Part 63, Subpart NNNNN). In addition, EPA considered whether to 
establish MACT standards for lightweight aggregate manufacturing 
facilities that do not burn hazardous waste, and determined that they 
are not major sources of HAP emissions. Thus, EPA has not established 
MACT standards for lightweight aggregate manufacturing facilities that 
do not burn hazardous waste.
    Note that non-stack emissions points are not regulated under 
Subpart EEE.\2\ Emissions attributable to storage and handling of 
hazardous waste prior to combustion (i.e., emissions from tanks, 
containers, equipment, and process vents) would continue to be 
regulated pursuant to either RCRA Subpart AA, BB, and CC and/or an 
applicable MACT that applies to the before-mentioned material handling 
devices. Emissions unrelated to the hazardous waste operations may be 
regulated pursuant to other MACT rulemakings. For example, Portland 
cement manufacturing facilities that combust hazardous waste are 
subject to both Subpart EEE and Subpart LLL, and hydrochloric acid 
production facilities that combust hazardous waste may be subject to 
both Subpart EEE and Subpart NNNNN.\3\ In these instances Subpart EEE 
controls HAP emissions from the cement kiln and hydrochloric acid 
production furnace stack, while Subparts LLL and NNNNN would control 
HAP emissions from other operations that are not directly related to 
the combustion of hazardous waste (e.g., clinker cooler emissions for 
cement production facilities, and hydrochloric acid product 
transportation and storage for hydrochloric acid production 
facilities).
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    \2\ Note, however, that fugitive emissions attributable to the 
combustion of hazardous waste from the combustion device are 
regulated pursuant to Subpart EEE.
    \3\ Hydrochloric acid production furnaces that combust hazardous 
waste are also affected sources subject to Subpart NNNNN if they 
produce a liquid acid product that contains greater than 30% 
hydrochloric acid.
---------------------------------------------------------------------------

    Note that if you temporarily cease burning hazardous waste for any 
reason, you remain an affected source and are still subject to the 
applicable Subpart

[[Page 59406]]

EEE requirements. However, even as an affected source, the emission 
standards or operating limits do not apply if: (1) Hazardous waste is 
not in the combustion chamber and you elect to comply with other MACT 
(or CAA section 129) standards that otherwise would be applicable if 
you were not burning hazardous waste, e.g., the nonhazardous waste 
burning Portland Cement Kiln MACT (Subpart LLL); or (2) you are in a 
startup, shutdown, or malfunction mode of operation.

V. What Are the Health Effects Associated With Pollutants Emitted by 
Hazardous Waste Combustors?

    Today's final rule protects air quality and promotes the public 
health by reducing the emissions of some of the HAP listed in Section 
112(b)(1) of the CAA. Emissions data collected in the development of 
this final rule show that metals, hydrogen chloride and chlorine gas, 
dioxins and furans, and other organic compounds are emitted from 
hazardous waste combustors. The HAP that would be controlled with this 
rule are associated with a variety of adverse health affects. These 
adverse health effects include chronic health disorders (e.g., 
irritation of the lung, skin, and mucus membranes and effects on the 
blood, digestive tract, kidneys, and central nervous system), and acute 
health disorders (e.g., lung irritation and congestion, alimentary 
effects such as nausea and vomiting, and effects on the central nervous 
system). Provided below are brief descriptions of risks associated with 
HAP that are emitted from hazardous waste combustors.

Antimony

    Antimony occurs at very low levels in the environment, both in the 
soils and foods. Higher concentrations, however, are found at antimony 
processing sites, and in their hazardous wastes. The most common 
industrial use of antimony is as a fire retardant in the form of 
antimony trioxide. Chronic occupational exposure to antimony (generally 
antimony trioxide) is most commonly associated with ``antimony 
pneumoconiosis,'' a condition involving fibrosis and scarring of the 
lung tissues. Studies have shown that antimony accumulates in the lung 
and is retained for long periods of time. Effects are not limited to 
the lungs, however, and myocardial effects (effects on the heart 
muscle) and related effects (e.g., increased blood pressure, altered 
EKG readings) are among the best-characterized human health effects 
associated with antimony exposure. Reproductive effects (increased 
incidence of spontaneous abortions and higher rates of premature 
deliveries) have been observed in female workers exposed in an antimony 
processing facilities. Similar effects on the heart, lungs, and 
reproductive system have been observed in laboratory animals.
    EPA assessed the carcinogenicity of antimony and found the evidence 
for carcinogenicity to be weak, with conflicting evidence from 
inhalation studies with laboratory animals, equivocal data from the 
occupational studies, negative results from studies of oral exposures 
in laboratory animals, and little evidence of mutagenicity or 
genotoxicity.\4\ As a consequence, EPA concluded that insufficient data 
are available to adequately characterize the carcinogenicity of 
antimony and, accordingly, the carcinogenicity of antimony cannot be 
determined based on available information. However, the International 
Agency for Research on Cancer in an earlier evaluation, concluded that 
antimony trioxide is ``possibly carcinogenic to humans'' (Group 2B).
---------------------------------------------------------------------------

    \4\ See ``Evaluating THe Carcinogenicity of Antimony,'' Rish 
Assessment Issue Paper (98-030/07-26-99), Superfund Technical 
Support Center, National Center for Environmental Assessment, July 
26, 1999.
---------------------------------------------------------------------------

Arsenic

    Chronic (long-term) inhalation exposure to inorganic arsenic in 
humans is associated with irritation of the skin and mucous membranes. 
Human data suggest a relationship between inhalation exposure of women 
working at or living near metal smelters and an increased risk of 
reproductive effects, such as spontaneous abortions. Inorganic arsenic 
exposure in humans by the inhalation route has been shown to be 
strongly associated with lung cancer, while ingestion or inorganic 
arsenic in humans has been linked to a form of skin cancer and also to 
bladder, liver, and lung cancer. EPA has classified inorganic arsenic 
as a Group A, human carcinogen.

Beryllium

    Chronic inhalation exposure of humans to high levels of beryllium 
has been reported to cause chronic beryllium disease (berylliosis), in 
which granulomatous (noncancerous) lesions develop in the lung. 
Inhalation exposure to high levels of beryllium has been demonstrated 
to cause lung cancer in rats and monkeys. Human studies are limited, 
but suggest a causal relationship between beryllium exposure and an 
increased risk of lung cancer. We have classified beryllium as a Group 
B1, probable human carcinogen, when inhaled; data are inadequate to 
determine whether beryllium is carcinogenic when ingested.

Cadmium

    Chronic inhalation or oral exposure to cadmium leads to a build-up 
of cadmium in the kidneys that can cause kidney disease. Cadmium has 
been shown to be a developmental toxicant in animals, resulting in 
fetal malformations and other effects, but no conclusive evidence 
exists in humans. An association between cadmium exposure and an 
increased risk of lung cancer has been reported from human studies, but 
these studies are inconclusive due to confounding factors. Animal 
studies have demonstrated an increase in lung cancer from long-term 
inhalation exposure to cadmium. EPA has classified cadmium as a Group 
B1, probable carcinogen.

Chlorine gas

    Chlorine is an irritant to the eyes, the upper respiratory tract, 
and lungs. Chronic exposure to chlorine gas in workers has resulted in 
respiratory effects including eye and throat irritation and airflow 
obstruction. No information is available on the carcinogenic effects of 
chlorine in humans from inhalation exposure. A National Toxicology 
Program (NTP) study showed no evidence of carcinogenic activity in male 
rats or male and female mice, and equivocal evidence in female rats, 
from ingestion of chlorinated water. The EPA has not classified 
chlorine for potential carcinogenicity. In the absence of specific 
scientific evidence to the contrary, it is the Agency's policy to 
classify noncarcinogenic effects as threshold effects. RfC development 
is the default approach for threshold (or nonlinear) effects.

Chromium

    Chromium may be emitted in two forms, trivalent chromium (chromium 
III) or hexavalent chromium (chromium VI). The respiratory tract is the 
major target organ for chromium VI toxicity for inhalation exposures. 
Bronchitis, decreases pulmonary function, pneumonia, and other 
respiratory effects have been noted from chronic high does exposure in 
occupational settings due to chromium VI. Limited human studies suggest 
that chromium VI inhalation exposure may be associated with 
complications during pregnancy and childbirth, while animal studies 
have not reported reproductive effects from inhalation exposure to 
chromium VI. Human and animal studies have clearly established that 
inhaled chromium VI is

[[Page 59407]]

a carcinogen, resulting in an increased risk of lung cancer. EPA has 
classified chromium VI as a Group A, human carcinogen.
    Chromium III is less toxic than chromium VI. The respiratory tract 
is also the major target organ for chromium III toxicity, similar to 
chromium VI. Chromium III is an essential element in humans, with a 
daily intake of 50 to 200 micrograms per day recommended for an adult. 
The body can detoxify some amount of chromium VI to chromium III. EPA 
has not classified chromium III with respect to carcinogenicity.

Cobalt

    Cobalt is a relatively rare metal that is produced primarily as a 
by-product during refining of other metals, especially copper. Cobalt 
has been widely reported to cause respiratory effects in humans exposed 
by inhalation, including respiratory irritation, wheezing, asthma, and 
pneumonia. Cardiomyopathy (damage to the heart muscle) has also been 
reported, although this effect is better known from oral exposure. 
Other effects of oral exposure in humans are polycythemia (an 
abnormally high number of red blood cells) and the blocking of uptake 
of iodine by the thyroid. In addition, cobalt is a sensitizer in humans 
by any route of exposure. Sensitized individuals may react to 
inhalation of cobalt by developing asthma or to ingestion or dermal 
contact with cobalt by developing dermatitis. Cobalt is as a vital 
component of vitamin B<INF>12</INF>, though there is no evidence that 
intake of cobalt is ever limiting in the human diet.
    A number of epidemiological studies have found that exposures to 
cobalt are associated with an increased incidence of lung cancer in 
occupational settings. The International Agency for Research on Cancer 
(part of the World Health Organization) classifies cobalt and cobalt 
compounds as ``possibly carcinogenic to humans'' (Group 2B). The 
American Conference of Governmental Industrial Hygienists has 
classified cobalt as a confirmed animal carcinogen with unknown 
relevance to humans (category A3). An EPA assessment concludes that 
under EPA's cancer guidelines, cobalt would be considered likely to be 
carcinogenic to humans.\5\
---------------------------------------------------------------------------

    \5\ See ``Derivation of a Provisional Carcinogenicity Assessment 
for Cobalt and Compounds,'' Risk Assessment Issue Paper (00-122/1-
15-02), Superfund Technical Support Center, National Center for 
Environmental Assessment, January 15, 2002. This is a provisional 
EPA assessment that has been externally peer reviewed but has not 
yet been incorporated in IRIS.
---------------------------------------------------------------------------

Dioxins and Furans

    Exposures to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) and 
related compounds at levels 10 times or less above those modeled to 
approximate average background exposure have resulted in adverse non-
cancer health effects in animals. This statement is based on 
assumptions about the toxic equivalent for these compounds, for which 
there is acknowledged uncertainty. These effects include changes in 
hormone systems, alterations in fetal development, reduced reproductive 
capacity, and immunosuppression. Effects that may be linked to dioxin 
and furan exposures at low dose in humans include changes in markers of 
early development and hormone levels. Dioxin and furan exposures are 
associated with altered liver function and lipid metabolism changes in 
activity of various liver enzymes, depression of the immune system, and 
endocrine and nervous system effects. EPA in its 1985 dioxin assessment 
classified 2,3,7,8-TCDD as a probable human carcinogen. The 
International Agency for Research on Cancer (IARC) concluded in 1997 
that the overall weight of the evidence was sufficient to characterize 
2,3,7,8-TCDD as a known human carcinogen.\6\ In 2001 the U.S. 
Department of Health and Human Services National Toxicology Program in 
their 9th Report on Carcinogens classified 2,3,7,8-TCDD as a known 
human carcinogen.\7\
---------------------------------------------------------------------------

    \6\ IARC (International Agency for Research on Cancer). (1997) 
IARC monographs on the evaluation of carcinogenic risks to humans. 
Vol. 69. Polychlorinated dibenzo-para-dioxins and polychlorinated 
dibenzofurans. Lyon, France.
    \7\ The U.S. Department of Health and Human Services, National 
Toxicology Program 9th Report on Carcinogens, Revised January 2001.
---------------------------------------------------------------------------

    The chemical and environmental stability of dioxins and their 
tendency to accumulate in fat have resulted in their detection within 
many ecosystems. In the United States and elsewhere, accidental 
contamination of the environment by 2,3,7,8-TCDD has resulted in deaths 
in many species of wildlife and domestic animals.\8\ High residues of 
this compound in fish have resulted in closing rivers to fishing. 
Laboratory studies with birds, mammals, aquatic organisms, and other 
species have demonstrated that exposure to 2,3,7,8-TCDD can result in 
acute and delayed mortality as well as carcinogenic, teratogenic, 
mutagenic, histopathologic, immunotoxic, and reproductive effects, 
depending on dose received, which varied widely in the experiments.\9\
---------------------------------------------------------------------------

    \8\ This does not necessarily apply in regard to laboratory 
testing, which tend to use 2,3,7,8 TCDD as the test compound.
    \9\ Eisler, R. 1986. Dioxin hazards to fish, wildlife, and 
invertebrates: a synoptic review. U.S. Fish and Wildlife Service 
Biological Report. 85(1.8).
---------------------------------------------------------------------------

Hydrogen chloride/hydrochloric acid

    Hydrogen chloride, also called hydrochloric acid, is corrosive to 
the eyes, skin, and mucous membranes. Chronic (long-term) occupational 
exposure to hydrochloric acid has been reported to cause gastritis, 
bronchitis, and dermatitis in workers. Prolonged exposure to low 
concentrations may also cause dental discoloration and erosion. No 
information is available on the reproductive or developmental effects 
of hydrochloric acid in humans. In rats exposed to hydrochloric acid by 
inhalation, altered estrus cycles have been reported in females and 
increased fetal mortality and decreased fetal weight have been reported 
in offspring. EPA has not classified hydrochloric acid for 
carcinogenicity. In the absence of specific scientific evidence to the 
contrary, it is the Agency's policy to classify noncarcinogenic effects 
as threshold effects. RfC development is the default approach for 
threshold (or nonlinear) effects.

Lead

    Lead can cause a variety of effects at low dose levels. Chronic 
exposure to high levels of lead in humans results in effects on the 
blood, central nervous system, blood pressure, and kidneys. Children 
are particularly sensitive to the chronic effects of lead, with slowed 
cognitive development, reduced growth and other effects reported. 
Reproductive effects, such as decreased sperm count in men and 
spontaneous abortions in women, have been associated with lead 
exposure. The developing fetus is at particular risk from maternal lead 
exposure, with low birth weight and slowed postnatal neurobehavioral 
development noted. Human studies are inconclusive regarding lead 
exposure and cancer, while animal studies have reported an increase in 
kidney cancer from lead exposure by the oral route. EPA has classified 
lead as a Group B2, probable human carcinogen.

Manganese

    Health effects in humans have been associated with both 
deficiencies and excess intakes of manganese. Chronic exposure to low 
levels of manganese in the diet is considered to be nutritionally 
essential in humans, with a recommended daily allowance of 2 to 5 
milligrams per day (mg/d). Chronic

[[Page 59408]]

exposure to high levels of manganese by inhalation in humans results 
primarily in central nervous system effects. Visual reaction time, hand 
steadiness, and eye-hand coordination were affected in chronically-
exposed workers. Impotence and loss of libido have been noted in male 
workers afflicted with manganism attributed to inhalation exposures. 
EPA has classified manganese in Group D, not classifiable as to 
carcinogenicity in humans.

Mercury

    Mercury exists in three forms: elemental mercury, inorganic mercury 
compounds (primarily mercuric chloride), and organic mercury compounds 
(primarily methyl mercury). Each form exhibits different health 
effects. Various sources may release elemental or inorganic mercury; 
environmental methyl mercury is typically formed by biological 
processes after mercury has precipitated from the air.
    Chronic exposure to elemental mercury in humans also affects the 
central nervous system, with effects such as increased excitability, 
irritability, excessive shyness, and tremors. The EPA has not 
classified elemental mercury with respect to cancer.
    The major effect from chronic exposure to inorganic mercury is 
kidney damage. Reproductive and developmental animal studies have 
reported effects such as alterations in testicular tissue, increased 
embryo resorption rates, and abnormalities of development. Mercuric 
chloride (an inorganic mercury compound) exposure has been shown to 
result in forestomach, thyroid, and renal tumors in experimental 
animals. EPA has classified mercuric chloride as a Group C, possible 
human carcinogen.

Nickel

    Nickel is an essential element in some animal species, and it has 
been suggested it may be essential for human nutrition. Nickel 
dermatitis, consisting of itching of the fingers, hand and forearms, is 
the most common effect in humans from chronic exposure to nickel. 
Respiratory effects have also been reported in humans from inhalation 
exposure to nickel. No information is available regarding the 
reproductive of developmental effects of nickel in humans, but animal 
studies have reported such effects, although a consistent dose-response 
relationship has not been seen. Nickel forms released from industrial 
boilers include soluble nickel compounds, nickel subsulfide, and nickel 
carbonyl. Human and animal studies have reported an increased risk of 
lung and nasal cancers from exposure to nickel refinery dusts and 
nickel subsulfide. Animal studies of soluble nickel compounds i.e., 
nickel carbonyl) have reported lung tumors. The EPA has classified 
nickel refinery subsulfide as a Group A, human carcinogen and nickel 
carbonyl as a Group B2, probable human carcinogen.

Organic HAP

    Organic HAPs include halogenated and nonhalogenated organic classes 
of compounds such as polycyclic aromatic hydrocarbons (PAHs) and 
polychlorinated biphenyls (PCBs). Both PAHs and PCBs are classified as 
potential human carcinogens, and are considered toxic, persistent and 
bioaccumulative. Organic HAP also include compounds such as benzene, 
methane, propane, chlorinated alkanes and alkenes, phenols and 
chlorinated aromatics. Adverse health effects of HAPs include damage to 
the immune system, as well as neurological, reproductive, 
developmental, respiratory and other health problems.

Particulate Matter

    Atmospheric particulate matter (PM) is composed of sulfate, 
nitrate, ammonium, and other ions, elemental carbon, particle-bound 
water, a wide variety of organic compounds, and a large number of 
elements contained in various compounds, some of which originate from 
crustal materials and others from combustion sources. Combustion 
sources are the primary origin of trace metals found in fine particles 
in the atmosphere. Ambient PM can be of primary or secondary origin.
    Exposure to particles can lead to a variety of serious health 
effects. The largest particles do not get very far into the lungs, so 
they tend to cause fewer harmful health effects. Fine particles pose 
the greatest problems because they can get deep into the lungs. 
Scientific studies show links between these small particles and 
numerous adverse health effects. Epidemiological studies have shown a 
significant correlation between elevated PM levels and premature 
mortality. Other important effects associated with PM exposure include 
aggravation of respiratory and cardiovascular disease (as indicated by 
increased hospital admissions, emergency room visits, absences from 
school or work, and restricted activity days), lung disease, decreased 
lung function, asthma attacks, and certain cardiovascular problems. 
Individuals particularly sensitive to PM exposure include older adults 
and people with heart and lung disease.
    This is only a partial summary of adverse health and environmental 
effects associated with exposure to PM. Further information is found in 
the 2004 Criteria Document for PM (``Air Quality Criteria for 
Particulate Matter,'' EPA/600/P-99/002bF) and the 2005 Staff Paper for 
PM (EPA, ``Review of the National Ambient Air Quality Standards for 
Particulate Matter, Policy Assessment of Scientific and Technical 
Information: OAQPS Staff Paper,'' (June 2005)).

Selenium

    Selenium is a naturally occurring substance that is toxic at high 
concentrations but is also a nutritionally essential element. Studies 
of humans chronically exposed to high levels of selenium in food and 
water have reported discoloration of the skin, pathological deformation 
and loss of nails, loss of hair, excessive tooth decay and 
discoloration, lack of mental alertness, and listlessness. The 
consumption of high levels of selenium by pigs, sheep, and cattle has 
been shown to interfere with normal fetal development and to produce 
birth defects. Results of human and animal studies suggest that 
supplementation with some forms of selenium may result in a reduced 
incidence of several tumor types. One selenium compound, selenium 
sulfide, is carcinogenic in animals exposed orally. We have classified 
elemental selenium as a Group D, not classifiable as to human 
carcinogenicity, and selenium sulfide as a Group B2, probable human 
carcinogen.

Part Two: Summary of the Final Rule

I. What Source Categories and Subcategories Are Affected by the Final 
Rule?

    Today's rule promulgates standards for controlling emissions of HAP 
from hazardous waste combustors: incinerators, cement kilns, 
lightweight aggregate kilns, boilers, and hydrochloric acid production 
furnaces that burn hazardous waste. A description of each source 
category can be found in the proposed rule (see 69 FR at 21207-08).
    Hazardous waste burning incinerators, cement kilns, and lightweight 
aggregate kilns are currently subject to 40 CFR part 63, subpart EEE, 
National Emission Standards for Hazardous Air Pollutants (NESHAP). 
Today's rule revises the emissions limits and certain compliance and 
monitoring provisions of subpart EEE for these

[[Page 59409]]

source categories. The definitions of hazardous waste incinerator, 
hazardous waste cement kiln, and hazardous waste lightweight aggregate 
kiln appear at 40 CFR 63.1201(a).
    Boilers that burn hazardous waste are also affected sources under 
today's rule. The rule uses the RCRA definition of a boiler under 40 
CFR 260.10 and includes industrial, commercial, and institutional 
boilers as well as thermal units known as process heaters. Hazardous 
waste burning boilers will continue to comply with the emission 
standards found under 40 CFR part 266, subpart H (i.e., the existing 
RCRA rules) until they demonstrate compliance with the requirements of 
40 CFR part 63, subpart EEE, and, for permitted sources, subsequently 
remove these requirements from their RCRA permit.
    Finally, hydrochloric acid production furnaces that burn hazardous 
waste are affected sources under today's rule. These furnaces are a 
type of halogen acid furnace included in the definition of ``industrial 
furnace'' defined at Sec.  260.10. Hydrochloric acid production 
furnaces that burn hazardous waste will continue to comply with the 
emission standards found under 40 CFR part 266, subpart H, until they 
demonstrate compliance with 40 CFR part 63, subpart EEE, and, for 
permitted sources, subsequently remove these requirements from their 
RCRA permit.

II. What Are the Affected Sources and Emission Points?

    Today's rule apply to each major and area source incinerator, 
cement kiln, lightweight aggregate kiln, boiler, and hydrochloric acid 
production furnace that burns hazardous waste.\10\ We note that only 
major source boilers and hydrochloric acid production furnaces are 
subject to the full suite of subpart EEE emission standards.\11\ The 
emissions limits apply to each emission point (e.g., stack) where gases 
from the combustion of hazardous waste are discharged or otherwise 
emitted into the atmosphere. For facilities that have multiple 
combustion gas discharge points, the emission limits generally apply to 
each emission point. A cement kiln, for example, could be configured to 
have dual stacks where the majority of combustion gases are discharged 
though the main stack and other combustion gases emitted through a 
separate stack, such as an alkali bypass stack. In that case, the 
emission standards would apply separately to each of these stacks.\12\
---------------------------------------------------------------------------

    \10\ A major source emits or has the potential to emit 10 tons 
per year of any single hazardous air pollutant or 25 tons per year 
or greater of hazardous air pollutants in the aggregate. An area 
source is a source that is not a major source.
    \11\ See Part Four, Section II.A for a discussion of the 
standards that are applicable to area source boilers and 
hydrochloric acid production furnaces.
    \12\ We note that there is a provision that allows cement kilns 
with dual stacks to average emissions on a flow-weighted basis to 
demonstrate compliance with the metal and chlorine emission 
standards. See Sec. Sec.  63.1204(e) and 63.1220(3).
---------------------------------------------------------------------------

III. What Pollutants Are Emitted and Controlled?

    Hazardous waste combustors emit dioxin/furans, sometimes at high 
levels depending on the design and operation of the emission control 
equipment, and, for incinerators, depending on whether a waste heat 
recovery boiler is used. All hazardous waste combustors can also emit 
high levels of other organic HAP if they are not designed, operated, 
and maintained to operate under good combustion conditions.
    Hazardous waste combustors can also emit high levels of metal HAP, 
depending on the level of metals in the waste feed and the design and 
operation of air emissions control equipment. Hazardous waste burning 
hydrochloric acid production furnaces, however, generally feed and emit 
low levels of metal HAP.
    All of these HAP metals (except for the volatile metal mercury) are 
emitted as a portion of the particulate matter emitted by these 
sources. Hazardous waste combustors can also emit high levels of 
particulate matter, except that hydrochloric acid production furnaces 
generally feed hazardous wastes with low ash content and consequently 
emit low levels of particulate matter. A majority of particulate matter 
emissions from hazardous waste combustors are in the form of fine 
particulate. Particulate emissions from incinerators and liquid fuel-
fired boilers depend on the ash content of the hazardous waste feed and 
the design and operation of air emission control equipment. Particulate 
emissions from cement kilns and lightweight aggregate kilns are not 
significantly affected by the ash content of the hazardous waste fuel 
because uncontrolled particulate emissions are attributable primarily 
to fine raw material entrained in the combustion gas. Thus, particulate 
emissions from kilns depends on operating conditions that effect 
entrainment of raw material, and the design and operation of the 
emission control equipment.

IV. Does the Final Rule Apply to Me?

    The final rule applies to you if you own or operate a hazardous 
waste combustor--an incinerator, cement kiln, lightweight aggregate 
kiln, boiler, or hydrochloric acid production facility that burns 
hazardous waste. The final rule does not apply to a source that meets 
the applicability requirements of Sec.  63.1200(b) for reasons 
explained at 69 FR at 21212-13.

V. What Are the Emission Limitations?

    You must meet the emission limits in Tables 1 and 2 of this 
preamble for your applicable source category and subcategory. Standards 
are corrected to 7 percent oxygen. As noted at proposal, we previously 
promulgated requirements for carbon monoxide, total hydrocarbon, and 
destruction and removal efficiency standards under subpart EEE for 
incinerators, cement kilns, and lightweight aggregate kilns. We view 
these standards as unaffected by the Court's vacature of the challenged 
regulations in its decision of July 24, 2001. We are therefore not re-
promulgating and reopening consideration of these standards in today's 
final rule, but are summarizing these standards in Tables 1 and 2 for 
reader's convenience.\13\ See 69 FR at 21221, 21248, 21261 and 21274.
---------------------------------------------------------------------------

    \13\ We are also republishing these standards, for reader's 
convenience only, in the new replacement standard section for these 
source categories. See Sec.  63.1219, Sec.  63.1220 and Sec.  
673.1219.
---------------------------------------------------------------------------

    Liquid fuel boilers equipped with dry air pollution control devices 
are subject to different dioxin/furan emission standards than liquid 
fuel boilers that are not equipped with dry air pollution control 
devices.\14\ Liquid fuel boilers processing hazardous waste with a 
heating value less than 10,000 BTU/lb must comply with the emission 
concentration-based standards (expressed as mass of total HAP emissions 
per volume of stack gas emitted) for mercury, semivolatile metals, low 
volatile metals, and total chlorine. Liquid fuel boilers processing 
hazardous waste with heating values greater than 10,000 BTU/lb must 
comply with thermal emissions-based standards (expressed as mass of HAP 
emissions attributable to the hazardous waste per million BTU input 
from the hazardous waste) for those same pollutants. Low volatile metal 
standards for liquid fuel boilers apply only to emissions of chromium, 
whereas the low volatile metal standard for the other source categories 
applies to the combined emissions of chromium, arsenic, and beryllium. 
Semivolatile metal standards apply to the combined emissions of lead 
and cadmium.
---------------------------------------------------------------------------

    \14\ Liquid fuel boilers equipped with a wet air pollution 
control device followed by a dry air pollution control device do not 
meet the definition of a dry air pollution device.
---------------------------------------------------------------------------

    For any of the source categories except hydrochloric acid 
production

[[Page 59410]]

furnaces, you may elect to comply with an alternative to the total 
chlorine standard under which you would establish site-specific, 
health-based emission limits for hydrogen chloride and chlorine based 
on national exposure standards. This alternative chlorine standard is 
discussed in part two, section IX and part four, section VII.
    Incinerators and liquid and solid fuel boilers may elect to comply 
with an alternative to the particulate matter standard that would limit 
emissions of all the semivolatile metal HAPs and low volatile metal 
HAPs. Under this alternative, the numerical emission limits for 
semivolatile metal and low volatile metal emission HAP are identical to 
the limitations included in Tables 1 and 2. However, for semivolatile 
metals, the alternative standard applies to the combined emissions of 
lead, cadmium, and selenium; for low volatile metals, the standard 
applies to the combined emissions of chromium, arsenic, beryllium, 
antimony, cobalt, manganese, and nickel. See Sec.  63.1219(e).

                                                Table 1.--Summary of Emission Limits for Existing Sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                       Hydrochloric acid
                                     Incinerators        Cement kilns         Lightweight      Solid fuel-fired    Liquid fuel-fired      production
                                                                            aggregate kilns       boilers \1\         boilers \1\        furnaces \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dioxin/Furans (ng TEQ/dscm).....  0.20 or 0.40 and    0.20 or 0.40 and    0.20 or rapid       CO or HC and DRE    0.40 for dry APCD   CO or HC and DRE
                                   temperature         temperature         quench below        standard as a       sources; CO or HC   standard as
                                   control <           control <           400[deg]F at kiln   surrogate.          and DRE standard    surrogate.
                                   400[deg]F at APCD   400[deg]F at APCD   exit.                                   as surrogate for
                                   inlet \6\.          inlet.                                                      others.
Mercury.........................  130 [mu]g/dscm....  Hazardous waste     120 hazardous       11 [mu]g/dscm.....  4.2E-5lb/MMBtu      Total chlorine
                                                       feed restriction    waste MTEC \11\                         \2\, \5\ or 19      standard as
                                                       of 3.0 ppmw and     feed restriction                        [mu]g/dscm \2\;     surrogate.
                                                       120 [mu]g/dscm      or 120 [mu]g/dscm                       depending on BTU
                                                       MTEC \11\; or 120   total emissions.                        content of
                                                       [mu]g/dscm total                                            hazardous waste
                                                       emissions.                                                  \13\.
Particulate Matter..............  0.013 gr/dscf \8\.  0.028 gr/dscf and   0.025 gr/dscf.....  0.030 gr/dscf \8\.  0.035 gr/dscf \8\.  Total chlorine
                                                       20% opacity \12\.                                                               standard as
                                                                                                                                       surrogate.
Semivolatile Metals (lead +       230 [mu]g/dscm....  7.6 E-4 lbs/MMBtu   3.0E-4 lb/MMBtu     180 [mu]g/dscm....  8.2 E-5 lb/MMBtu    Total chlorine
 cadmium).                                             \5\ and 330 [mu]g/  \5\ and 250 [mu]g/                      \2\, \5\ or 150     standard as
                                                       dscm \3\.           dscm \3\.                               [mu]g/dscm \2\;     surrogate.
                                                                                                                   depending on BTU
                                                                                                                   content of
                                                                                                                   hazardous waste
                                                                                                                   \13\.
Low Volatile Metals (arsenic +    92 [mu]g/dscm.....  2.1 E-5 lbs/MMBtu   9.5E-5 lb/MMBtu     380 [mu]g/dscm....  1.26E-4 lbMMBtu     Total chlorine
 beryllium + chromium).                                \5\ and 56 [mu]g/   \5\ and 110 [mu]g/                      \4\, \5\ or 370     standard as
                                                       dscm \3\.           dscm \3\.                               [mu]g/dscm \4\;     surrogate.
                                                                                                                   depending on BTU
                                                                                                                   content of
                                                                                                                   hazardous waste
                                                                                                                   \13\.
Total Chlorine (hydrogen          32 ppmv \7\.......  120 ppmv \7\......  600 ppmv \7\......  440 ppmv \7\......  5.08E-2 lb/MMBtu    150 ppmv or
 chloride + chlorine gas).                                                                                         \5\, \7\ or 31      99.923% system
                                                                                                                   ppmv \7\;           removal
                                                                                                                   depending on BTU    efficiency.
                                                                                                                   content of
                                                                                                                   hazardous waste
                                                                                                                   \13\.
Carbon Monoxide (CO) or           100 ppmv CO \9\ or  See Note <greek-i>  100 ppmv CO \9\ or               (2) 100 ppmv CO \9\ or 10 ppmv HC
 Hydrocarbons (HC).                10 ppmv HC.         10 below.           20 ppmv HC.
Destruction and Removal             99.99% for each principal organic hazardous pollutant. For sources burning hazardous wastes F020, F021, F022, F023,
 Efficiency.                                         F026, or F027, however, 99.9999% for each principal organic hazardous pollutant.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\1\ Particulate matter, semivolatile metal, low volatile metal, and total chlorine standards for solid and liquid fuel boilers apply only to major
  sources. Particulate matter, semivolatile and low volatile metal standards for hydrochloric acid production furnaces apply only to major sources,
  although area sources must still comply with the surrogate total chlorine standard to control mercury emissions.
\2\ Standard is based on normal emissions data, and is therefore expressed as an annual average emission limitation.
\3\ Sources must comply with both the thermal emissions and emission concentration standards.
\4\ Low volatile metal standard for liquid fuel-fired boilers is for chromium only.
\5\ Standards expressed as mass of pollutant contributed by hazardous waste per million BTU contributed by the hazardous waste.
\6\ APCD means ``air pollution control device''.
\7\ Sources may elect to comply with site-specific risk-based emission limits for hydrogen chloride and chlorine gas
\8\ Sources may elect to comply with an alternative to the particulate matter standard.
\9\ Sources that elect to comply with the CO standard must demonstrate compliance with the HC standard during the comprehensive performance test that
  demonstrates compliance with the destruction and removal efficiency requirement.
\10\ Kilns without a bypass: 20 ppmv HC or 100 ppmv CO \9\. Kilns with a bypass/mid-kiln sampling system: 10 ppmv HC or 100 ppmv CO9 in the bypass duct,
  mid-kiln sampling system or bypass stack.
\11\ MTEC means ``maximum theoretical emission concentration'', and is equivalent to the feed rate divided by gas flow rate
\12\ The opacity standard does not apply to a source equipped with a bag leak detection system under 63.1206(c)(8) or a particulate matter detection
  system under 63.1206(c)(9).
\13\ Emission concentration-based standards apply to sources processing hazardous waste with energy content less than 10,000 BTU/lb; thermal emission
  standards apply to sources processing hazardous waste with energy content greater than 10,000 btu/lb.


[[Page 59411]]


                                          Table 2.--Summary of Emission Limits for New or Reconstructed Sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                       Hydrochloric acid
                                     Incinerators        Cement kilns         Lightweight     Solid fuel boilers      Liquid fuel         production
                                                                            aggregate kilns           \1\             boilers \1\        furnaces \1\
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Dioxin/Furans (ng TEQ/dscm).....  0.11 for dry APCD   0.20 or 0.40 and    0.20 or rapid       CO or HC and DRE    0.40 for sources    CO or THC and DRE
                                   and/or WHB \5\      temperature         quench <400         standard as a       with dry APCD; CO   standard as a
                                   sources; 0.20 for   control <400        [deg]F at kiln      surrogate.          or HC and DRE       surrogate.
                                   other sources.      [deg]F at APCD      exit.                                   standard as a
                                                       inlet.                                                      surrogate for
                                                                                                                   other sources.
Mercury.........................  8.1 [mu]g/dscm....  Hazardous waste     120 hazardous       11 [mu]g/dscm.....  1.2E-6 lb/MMBtu 2   TCl as surrogate.
                                                       feed restriction    waste MTEC \10\                         4 or 6.8 [mu]g/
                                                       of 1.9 ppmw and     feed restriction                        dscm \2\;
                                                       120 [mu]g/dscm      or 120 [mu]g/dscm                       depending on BTU
                                                       MTEC \10\; or 120   total emissions.                        content of
                                                       [mu]g/dscm total                                            hazardous waste
                                                       emissions.                                                  \12\.
Particulate matter (gr/dscf)....  0.0015 \7\........  0.0023 and 20%      0.0098............  0.015 \7\.........  0.0087 \7\........  TCl as surrogate.
                                                       opacity \11\.
Semivolatile Metals (lead +       10 [mu]g/dscm.....  6.2E-5 lb/MMBtu     3.7 E-5 lb/MMBtu    180 [mu]g/dscm....  6.2 E-6 lb/MMBtu 2  TCl as surrogate.
 cadmium).                                             \4\ and 180 [mu]g/  \4\ and 43 [mu]g/                       4 or 78 [mu]g/
                                                       dscm.               dscm.                                   dscm \2\;
                                                                                                                   depending on BTU
                                                                                                                   content of
                                                                                                                   hazardous waste
                                                                                                                   \12\.
Low Volatile Metals (arsenic +    23 [mu]g/dscm.....  1.5E-5 lb/MMBtu     3..3E-5 lb/MMBtu    190 [mu]g/dscm....  1.41E-5lb/MMBtu 3   TCl as surrogate.
 beryllium + chromium).                                \4\ and 54 [mu]g/   \4\ and 110 [mu]g/                      4 or 12 [mu]g/
                                                       dscm.               dscm.                                   dscm \3\;
                                                                                                                   depending on BTU
                                                                                                                   content of
                                                                                                                   hazardous waste
                                                                                                                   \12\.
Total Chlorine (Hydrogen          21 ppmv \6\.......  86 ppmv \6\.......  600 ppmv \6\......  73 ppmv \6\.......  5.08E-2 lb/MMBtu 4  25 ppmv or 99.987%
 chloride + chlorine gas).                                                                                         6 or 31 ppmv \6\;   SRE.
                                                                                                                   depending on BTU
                                                                                                                   content of
                                                                                                                   hazardous waste
                                                                                                                   \12\.
Carbon monoxide (CO) or           100 ppmv CO \8\ or  See note <greek-    100 ppmv CO \8\ or                 100 ppmv CO \8\ or 10 ppmv HC
 Hydrocarbons (HC).                10 ppmv HC.         i>9 below.          20 ppmv HC.
Destruction and Removal             99.99% for each principal organic hazardous pollutant. For sources burning hazardous wastes F020, F021, F022, F023,
 Efficiency.                                         F026, or F027, however, 99.9999% for each principal organic hazardous pollutant.
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Notes:
\1\ Particulate matter, semivolatile metal, low volatile metal, and total chlorine standards for solid and liquid fuel boilers apply only to major
  sources. Particulate matter, semivolatile and low volatile metal standards for hydrochloric acid production furnaces apply only to major sources,
  although area sources must still comply with the surrogate total chlorine standard to control mercury emissions.
\2\ Standard is based on normal emissions data, and is therefore expressed as an annual average emission limitation.
\3\ Low volatile metal standard for liquid fuel-fired boilers is for chromium only. Arsenic and beryllium are not included in the low volatile metal
  total for liquid fuel-fired boilers.
\4\ Standards expressed as mass of pollutant contributed by hazardous waste per million BTU contributed by the hazardous waste.
\5\ APCD means ``air pollution control device'', WHB means ``waste heat boiler''.
\6\ Sources may elect to comply with risk-based emission limits for hydrogen chloride and chlorine gas.
\7\ Sources may elect to comply with an alternative to the particulate matter standard.
\8\ Sources that elect to comply with the CO standard must demonstrate compliance with the THC standard during the comprehensive performance test that
  demonstrates compliance with the destruction and removal efficiency requirement.
\9\ Greenfield kilns without a bypass: 20 ppmv HC or 100 ppmv CO \8\ and 50 ppmv HC. Greenfield kilns with a bypass/mid kiln sampling system: Main stack
  standard of 50 ppmv HC and 10 ppmv HC or 100 ppmv CO \8\ in the bypass duct, mid-kiln sampling system or bypass stack. Greenfield kilns with a bypass/
  mid-kiln sampling system: 10 ppmv HC or 100 ppmv CO \8\ in the bypass duct, mid-kiln sampling system or bypass stack; Non-greenfield kilns without a
  bypass: 20 ppmv HC or 100 ppmv CO \8\. A greenfield kiln is a kiln whose construction commenced after April 19, 1996 at a plant site where a cement
  kiln (whether burning hazardous waste or not) did not previously exist.
\10\ MTEC means ``maximum theoretical emission concentration'', and is equivalent to the feed rate divided by gas flow rate.
\11\ The opacity standard does not apply to a source equipped with a bag leak detection system under 63.1206(c)(8) or a particulate matter detection
  system under 63.1206(c)(9).
\12\ Emission concentration-based standards apply to sources processing hazardous waste with energy content less than 10,000 BTU/lb; thermal emission
  standards apply to sources processing hazardous waste with energy content greater than 10,000 btu/lb.

VI. What Are the Testing and Initial Compliance Requirements?

    The testing and initial compliance requirements we promulgate today 
for solid fuel boilers, liquid fuel boilers, and hydrochloric acid 
production furnaces are identical to those that are applicable to 
incinerators, cement kilns, and lightweight aggregate kilns at 
Sec. Sec.  63.1206, 63.1207, and 63.1208. We note, however, that 
today's final rule revises some of these requirements as they apply to 
all or specific HWCs (e.g., one-time dioxin/furan test for sources not 
subject to a numerical dioxin/furan standard; dioxin/furan stack test 
method; hydrogen chloride and chlorine stack test methods)
    We also discuss compliance and testing dates for incinerators, 
cement kilns, and lightweight aggregate kilns as well. Even though we 
are not repromulgating the compliance and testing requirements for 
those source categories, those sources must demonstrate compliance with 
the replacement emission standards promulgated today.

[[Page 59412]]

A. Compliance Dates

    The time-line for testing and initial compliance requirements is as 
follows:
    1. The compliance date is October 14, 2008; \15\
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    \15\ See 69 FR at 21313 for rationale. We received no adverse 
comments at proposal.
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    2. You must submit a comprehensive performance test plan to the 
permitting authority for review and approval 12 months prior to 
commencing the test.
    3.You must submit an eligibility demonstration for the health-based 
compliance alternative to the total chlorine emission standard 12 
months before the compliance date if you elect to comply with Sec.  
63.1215;
    4. You must place in the operating record a Documentation of 
Compliance by the compliance date identifying the operating parameter 
limits that, using available information, you have determined will 
ensure compliance with the emission standards;
    5. For boilers and hydrochloric acid production furnaces, you must 
commence the initial comprehensive performance test within 6 months 
after the compliance date;
    6. For incinerators, cement kilns, and lightweight aggregate kilns, 
you must commence the initial comprehensive performance test within 12 
months after the compliance date;
    7. You must complete the initial comprehensive performance test 
within 60 days of commencing the test; and
    8. You must submit a Notification of Compliance within 90 days of 
completing the test documenting compliance with emission standards and 
continuous monitoring system requirements.

B. Testing Requirements

    All hazardous waste combustors must commence the initial 
comprehensive performance test under the time lines discussed above. 
The purpose of the comprehensive performance test is to document 
compliance with the emission standards of the final rule and establish 
operating parameter limits to maintain compliance with those standards. 
You must also conduct periodic comprehensive performance testing every 
five years.
    If your source is subject to a numerical dioxin/furan emission 
standard (i.e., incinerators, cement kilns, lightweight aggregate kilns 
that comply with the 0.2 ng TEQ/dscm standard, and liquid fuel boilers 
equipped with a dry air pollution control device), you must conduct a 
dioxin/furan confirmatory performance test no later than 2.5 years 
after each comprehensive performance test (i.e., midway between 
comprehensive performance tests). If your source is not subject to a 
numerical dioxin/furan emission standard (e.g., solid fuel boilers, 
lightweight aggregate kilns that comply with the 400 [deg]F temperature 
limit at the kiln exit, liquid fuel boilers equipped with wet or no air 
pollution control system, and hydrochloric acid production furnaces), 
you must conduct a one-time dioxin/furan test to enable the Agency to 
evaluate the effectiveness of the carbon monoxide/hydrocarbon standard 
and the destruction and removal efficiency standard in controlling 
dioxin/furan emissions for those sources. Previous dioxin/furan 
emission tests may be used to meet this requirement if the combustor 
operated under the conditions required by the rule and if design and 
operation of the combustor has not changed since the test in a manner 
that could increase dioxin/furan emissions. The Agency will use those 
emissions data when reevaluating the MACT standards under CAA section 
112(d)(6), when determining whether to develop residual risk standards 
for these sources pursuant to section 112(f)(2), and when determining 
whether the source's RCRA Permit is protective of human health and the 
environment.
    You must use the following stack test methods to document 
compliance with the emission standards: (1) Method 29 for mercury, 
semivolatile metals, and low volatile metals; and (2) Method 26/26A, 
Methods 320 or 321, or ASTM D 6735-01 for hydrogen chloride and 
chlorine; \16\ (3) either Method 0023A or Method 23 for dioxin/furans; 
and (4) either Method 5 or 5i for particulate matter.
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    \16\ Note that you may be required to use other test methods to 
document emissions of hydrogen chloride and chlorine if you elect to 
comply with the alternative, health-based emission limits for total 
chlorine under Sec.  63.1215. See Sec.  63.1208(b)(5).
---------------------------------------------------------------------------

C. Initial Compliance Requirements

    The initial compliance requirements for solid fuel boilers, liquid 
fuel boilers, and hydrochloric acid production furnaces include: \17\
---------------------------------------------------------------------------

    \17\ These same requirements currently apply to incinerators, 
cement kilns, and lightweight aggregate kilns.
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    1. You must place in the operating record a Documentation of 
Compliance by the compliance date identifying the operating parameter 
limits that, using available information, you have determined will 
ensure compliance with the emission standards;
    2. You must develop and comply with a startup, shutdown, and 
malfunction plan;
    3. You must install an automatic waste feed cutoff system that 
links the operating parameter limits to the waste feed cutoff system;
    4. You must control combustion system leaks;
    5. You must establish and comply with an operator training and 
certification program;
    6. You must establish and comply with an operation and maintenance 
plan;
    7. If your source is equipped with a baghouse, you must install 
either a bag leak detection system or a particulate matter detection 
system; \18\ and
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    \18\ A major difference between a bag leak detection system and 
a particulate matter detection system is the way the alarm level is 
established. The alarm level for a bag leak detection system is 
established using concepts in the Agency's bag leak detection system 
guidance document while the alarm level for a particulate matter 
detection system is established based on the detector response 
during the comprehensive performance test. The ash feedrate limit 
for incinerators and boilers is waived if you use a particulate 
matter detection system but not if you use a bag leak detection 
system because the bag leak detection system alarm level may not 
provide reasonable assurance of continuous compliance with the 
particulate matter emission standard.
---------------------------------------------------------------------------

    8. If your source is equipped with an electrostatic precipitator or 
ionizing wet scrubber, you must either establish site-specific control 
device operating parameter limits which limits are linked to the 
automatic waste feed cutoff system, or install a particulate matter 
detection system and take corrective measures when the alarm level is 
exceeded.

VII. What Are the Continuous Compliance Requirements?

    The continuous compliance requirements for solid fuel boilers, 
liquid fuel boilers, and hydrochloric acid production furnaces are 
identical to those applicable to incinerators, cement kilns, and 
lightweight aggregate kilns. See Sec.  63.1209. We note, however, that 
today's final rule revises some of these requirements as they apply to 
all or specific HWCs (e.g., bag leak detection system requirements; 
optional particulate matter detection system requirements; compliance 
assurance for thermal emissions-based standards).
    You must use carbon monoxide or hydrocarbon continuous emissions 
monitors (as well as an oxygen continuous emissions monitor to correct 
the carbon monoxide or hydrocarbon values to 7% oxygen) to ensure 
compliance with the carbon monoxide or hydrocarbon emission standards.
    You must also establish limits (as applicable) on the feedrate of 
metals, chlorine, and ash, key combustor operating parameters, and key 
operating

[[Page 59413]]

parameters of the air pollution control device based on operations 
during the comprehensive performance test. You must continuously 
monitor these parameters with a continuous monitoring system.

VIII. What Are the Notification, Recordkeeping, and Reporting 
Requirements?

    The notification, recordkeeping, and reporting requirements that we 
promulgate today for solid fuel boilers, liquid fuel boilers, and 
hydrochloric acid production furnaces are identical to those that are 
applicable to incinerators, cement kilns, and lightweight aggregate 
kilns. See Sec. Sec.  63.1210 and 63.1211. We note, however, that 
today's final rule revises some of these requirements as they apply to 
all or specific HWCs.
    You must submit notifications including the following to the 
permitting authority in addition to those required by the NESHAP 
General Provisions, subpart A of 40 CFR part 63:
    1. Notification of changes in design, operation, or maintenance 
(Sec.  63.1206(b)(5)(i));
    2. Notification of performance test and continuous monitoring 
system evaluation, including the performance test plan and continuous 
monitoring system performance evaluation plan (Sec.  63.1207(e));
    3. Notification of compliance, including results of performance 
tests and continuous monitoring system evaluations (Sec. Sec.  
63.1210(b), 63.1207(j); 63.1207(k), and 63.1207(l)); and
    4. Various notifications if you request or elect to comply with 
alternative requirements at Sec.  63.1210(a)(2).
    You must submit the following reports to the permitting authority 
in addition to those required by the NESHAP General Provisions, subpart 
A of 40 CFR part 63:
    1. Startup, shutdown, and malfunction plan, if you elect to comply 
with Sec.  63.1206(c)(2)(ii)(B));
    2. Excessive exceedances report (Sec.  63.1206(c)(3)(vi)); and
    3. Emergency safety vent opening reports (Sec.  63.1206(c)(4)(iv)).
    Finally, you must keep records documenting compliance with the 
requirements of Subpart EEE. Recordkeeping requirements are prescribed 
in Sec.  63.1211(b), and include requirements under the NESHAP General 
Provisions, subpart A of 40 CFR

IX. What Is the Health-Based Compliance Alternative for Total Chlorine, 
and How Do I Demonstrate Eligibility?

A. Overview

    The rule allows you to establish and comply with health-based 
compliance alternatives for total chlorine for hazardous waste 
combustors other than hydrochloric acid production furnaces in lieu of 
the MACT technology-based emission standards established under 
Sec. Sec.  63.1216, 63.1217, 63.1219, 63.1220, and 63.1221. See Sec.  
63.1215. To identify and comply with the limits, you must:
    (1) Identify a total chlorine emission rate for each on-site 
hazardous waste combustor. You may select total chlorine emission rates 
as you choose to demonstrate eligibility for the health-based limits, 
except the total chlorine emission rate limits for incinerators, cement 
kilns, and lightweight aggregate kilns cannot result in total chlorine 
emission concentrations exceeding the Interim Standards provided by 
Sec. Sec.  63.1203, 63.1204, and 63.1205;\19\
---------------------------------------------------------------------------

    \19\ Note that the final rule sunsets the Interim Standards on 
the compliance date of today's rule but codifies the Interim 
Standards for total chlorine under Sec.  63.1215(b)(7).
---------------------------------------------------------------------------

    (2) Calculate the HCl-equivalent emission rate for the total 
chlorine emission rates you select, considering long-term exposure and 
using Reference Concentrations (RfCs) as the health threshold metric. 
This emission rate is called the annual average HCl-equivalent emission 
rate;
    (3) Perform an eligibility demonstration to determine if your 
annual average HCl-equivalent emission rate meets the national exposure 
standard (i.e., Hazard Index not exceeding 1.0 considering the maximum 
annual average ambient concentration of hydrogen chloride and chlorine 
at an off-site receptor location which concentrations are attributable 
to all on-site hazardous waste combustors) and thus is below the annual 
average HCl-equivalent emission rate limit;
    (4) Calculate the HCl-equivalent emission rate for the total 
chlorine emission rates you select, considering short-term exposure and 
using acute Reference Exposure Levels (aRELs) as the health threshold 
metric. This emission rate is called the 1-hour average HCl-equivalent 
emission rate.
    (5) Determine whether your 1-hour HCl-equivalent emission rate may 
exceed the national exposure standard (i.e., Hazard Index not exceeding 
1.0 considering the maximum 1-hour average ambient concentration of 
hydrogen chloride and chlorine at an off-site receptor location which 
concentrations are attributable to all on-site hazardous waste 
combustors) and thus may exceed the 1-hour average HCl-equivalent 
emission rate limit when complying with the annual average HCl-
equivalent emission rate limit, absent an hourly rolling average limit 
on the feedrate of total chlorine and chloride.
    (6) Submit your eligibility demonstration, including your 
determination of whether the 1-hour average HCl-equivalent emission 
rate limit may be exceeded absent an hourly rolling average limit on 
the feedrate of total chlorine and chloride, for review and approval;
    (7) Document during the comprehensive performance test the total 
chlorine system removal efficiency for each combustor and use this 
system removal efficiency to calculate chlorine feedrate limits. Also, 
document that total chlorine emissions during the test do not exceed 
the 1-hour average HCl-equivalent emission rate limit during any run of 
the test. In addition, establish operating limits on the emission 
control device based on operations during the comprehensive performance 
test; and
    (8) Comply with the requirements for changes in the design, 
operation, or maintenance of the facility which could affect the HCl-
equivalent emission rate limits or system removal efficiency for total 
chlorine, and changes in the vicinity of your facility over which you 
do not have control (e.g., new receptors locating proximate to the 
facility).

B. HCl-Equivalent Emission Rates

    You must express total chlorine emission rates (lb/hr) from each 
on-site hazardous waste combustor, including hydrochloric acid 
production furnaces \20\, as an annual average HCl-equivalent emission 
rate and a 1-hour average HCl-equivalent emission rate. See Sec.  
63.1215(b). The annual average HCl-equivalent emission rate equates 
chlorine emission rates to hydrogen chloride (HCl) emission rates using 
Reference Concentrations (RfCs) as the health risk metric for long-term 
exposure. The 1-hour average HCl-equivalent emission rate equates 
chlorine emission rates to HCl emission rates using 1-hour Reference 
Exposure

[[Page 59414]]

Levels (aRELs) as the health risk metric for acute exposure.
---------------------------------------------------------------------------

    \20\ Although hydrochloric acid production furnaces are not 
eligible for the health-based total chlorine emission limits 
(because control of total chlorine is a surrogate for control of 
metal HAP), you must consider total chlorine emissions from 
hydrochloric acid production furnaces when demonstrating that total 
chlorine emissions from all on-site hazardous waste combustors will 
not exceed the Hazard Index limit of 1.0 at an off-site receptor 
location.
---------------------------------------------------------------------------

    To calculate HCl-equivalent emission rates, you must apportion 
total chlorine emissions (ppmv) between chlorine and HCl using the 
volumetric ratio of chlorine to hydrogen chloride (Cl<INF>2</INF>/HCl).
    <bullet> To calculate the annual average HCl-equivalent emission 
rate (lb/hr) and the emission rate limit, you must use the historical 
average Cl<INF>2</INF>/HCl volumetric ratio from all regulatory 
compliance tests and the gas flowrate (and other relevant parameters) 
from the most recent RCRA compliance test or MACT performance test.
    <bullet> To calculate the 1-hour average HCl-equivalent emission 
rate (lb/hr) and emission rate limit, you must use the highest 
Cl<INF>2</INF>/HCl volumetric ratio from all regulatory compliance 
tests and the gas flowrate from the most recent RCRA compliance test or 
MACT performance test.
    <bullet> If you believe that the Cl<INF>2</INF>/HCl volumetric 
ratio for one or more historical compliance tests is not representative 
of the current ratio, you may request that the permitting authority 
allow you to screen those ratios from the analysis of historical 
ratios.
    <bullet> If the permitting authority believes that too few 
historical Cl<INF>2</INF>/HCl ratios are available to establish a 
representative average ratio and a representative maximum ratio, the 
permitting authority may require you to conduct periodic testing to 
establish representative ratios.
    <bullet> You must include the Cl<INF>2</INF>/HCl volumetric ratio 
demonstrated during each performance test in your data base of 
historical Cl<INF>2</INF>/HCl ratios to update the ratios for 
subsequent calculations of the annual average and 1-hour average HCl-
equivalent emission rates (and emission rate limits).

C. Eligibility Demonstration

    You must perform an eligibility demonstration to determine whether 
the total chlorine emission rates you select for each on-site hazardous 
waste combustor meet the national exposure standard (i.e., the Hazard 
Index of 1.0 cannot be exceeded at an off-site receptor location 
considering maximum annual average ambient concentrations attributable 
to all on-site hazardous waste combustors and the RfCs for HCl and 
chlorine) using either a look-up table analysis or a site-specific 
compliance demonstration.\21\ Eligibility for the health-based total 
chlorine standard is determined by comparing the annual average HCl-
equivalent emission rate for the total chlorine emission rate you 
select for each combustor to the annual average HCl-equivalent emission 
rate limit.
---------------------------------------------------------------------------

    \21\ The total chlorine emission rates (lb/hr) for incinerators, 
cement kilns, and lightweight aggregate kilns cannot result in total 
chlorine emission concentrations (ppmv) exceeding the Interim 
Standards provided by Sec. Sec.  63.1203, 63.1204, and 63.1205. The 
final rule sunsets the Interim Standards on the compliance date of 
today's rule but codifies the Interim Standards for total chlorine 
under Sec.  63.1215(b)(7).
---------------------------------------------------------------------------

    The annual average HCl-equivalent emission rate limit is the HCl-
equivalent emission rate, determined by equating the toxicity of 
chlorine to HCl using RfCs as the health risk metric for long-term 
exposure, which ensures that maximum annual average ambient 
concentrations of HCl equivalents do not exceed a Hazard Index of 1.0, 
rounded to the nearest tenths decimal place (0.1) and considering all 
on-site hazardous waste combustors. See Sec.  63.1215(b)(2).
    Your facility is eligible for the health-based compliance 
alternatives for total chlorine if either: (1) The annual average HCl-
equivalent emission rate for each on-site hazardous waste combustor is 
below the HCl-equivalent emission rate limit determined from the 
appropriate value for the emission rate limit in the applicable look-up 
table and the proration procedure for multiple combustors discussed 
below; or (2) the annual average HCl-equivalent emission rate for each 
on-site hazardous waste combustor is below the annual average HCl-
equivalent emission rate limit you calculate based on a site-specific 
compliance demonstration.
1. Look-Up Table Analysis
    Look-up tables for the eligibility demonstration are provided as 
Tables 1 and 2 to Sec.  63.1215. Table 1 presents annual average HCl-
equivalent emission rate limits for sources located in flat terrain. 
For purposes of this analysis, flat terrain is terrain that rises to a 
level not exceeding one half the stack height within a distance of 50 
stack heights.
    Table 2 presents annual average HCl-equivalent emission rate limits 
for sources located in simple elevated terrain. For purposes of this 
analysis, simple elevated terrain is terrain that rises to a level 
exceeding one half the stack height, but that does not exceed the stack 
height within a distance of 50 stack heights.
    If your facility is not located in either flat or simple elevated 
terrain, you must conduct a site-specific compliance demonstration.
    To determine the annual average HCl-equivalent emission rate limit 
for a source from the look-up table, you must use the stack height and 
stack diameter for your hazardous waste combustors and the distance 
between the stack and the property boundary. If any of these values for 
stack height, stack diameter, and distance to nearest property boundary 
do not match the exact values in the look-up table, you must use the 
next lowest table value. If you have more than one hazardous waste 
combustor on site, you must adjust the emission rate limits provided by 
the tables such that the sum of the ratios for all combustors of the 
adjusted emission rate limit to the emission rate limit provided by the 
table cannot exceed 1.0. See Sec.  63.1215 (c)(3)(v).
2. Site-Specific Compliance Demonstration
    You may use any scientifically-accepted peer-reviewed risk 
assessment methodology for your site-specific compliance demonstration 
to calculate an annual average HCl-equivalent emission rate limit for 
each on-site hazardous waste combustor. An example of one approach for 
performing the demonstration for air toxics can be found in the EPA's 
``Air Toxics Risk Assessment Reference Library, Volume 2, Site-Specific 
Risk Assessment Technical Resource Document,'' which may be obtained 
through the EPA's Air Toxics Web site at http://www.epa.gov/ttn/atw.
    To determine the annual average HCl-equivalent emission rate limit 
for each on-site hazardous waste combustor, your site-specific 
compliance demonstration must, at a minimum: (1) estimate long-term 
inhalation exposures through the estimation of annual or multi-year 
average ambient concentrations; (2) estimate the inhalation exposure 
for the actual individual most exposed to the facility's emissions from 
hazardous waste combustors, considering locations where people reside 
and where people congregate for work, school, or recreation; (3) use 
site-specific, quality-assured data wherever possible; (4) use health-
protective default assumptions wherever site-specific data are not 
available, and: (5) contain adequate documentation of the data and 
methods used for the assessment so that it is transparent and can be 
reproduced by an experienced risk assessor and emissions measurement 
expert.
    To establish the annual average HCl-equivalent emission rate limit 
for each combustor, you may apportion as you elect among the combustors 
the annual average HCl-equivalent emission rate limit for the facility, 
which limit ensures that the RfC-based Hazard Index of 1.0 is not 
exceeded.

[[Page 59415]]

D. Assurance That the 1-Hour HCl-Equivalent Emission Rate Will Not Be 
Exceeded

    The long-term, RfC-based Hazard Index will always be higher than 
the short-term, aREL-based Hazard Index for a constant HCl-equivalent 
emission rate because the health threshold levels for short-term 
exposure are orders of magnitude higher than the health threshold 
levels for long-term exposure.\22\ Even though maximum 1-hour average 
ambient concentrations are substantially higher than maximum annual 
average concentrations, the higher short-term ambient concentrations do 
not offset the much higher health threshold levels for short-term 
exposures. Thus, the long-term, RfC-based Hazard Index will always 
govern regarding whether a source can make an eligibility 
demonstration. Accordingly, eligibility for the health-based emission 
limits is based solely on whether a source can comply with the annual 
average HCl-equivalent emission rate limit.
---------------------------------------------------------------------------

    \22\ USEPA, ``Technical Support Document for HWC MACT Standards, 
Volume III: Selection of MACT Standards,'' September 2005, Section 
24.2.
---------------------------------------------------------------------------

    Nonetheless, some sources may have highly variably chlorine 
feedrates (and corresponding highly variable HCl-equivalent emission 
rates) such that they may feed chlorine at very high levels for short 
periods of time and still remain in compliance with the chlorine 
feedrate limit established to ensure compliance with the annual average 
HCl-equivalent emission rate limit.\23\ To ensure that the 1-hour HCl-
equivalent emission rate limit will not be exceeded during these 
periods of peak emissions, you must establish a 1-hour average HCl-
equivalent emission rate and 1-hour average HCl-equivalent emission 
rate limit for each combustor and consider site-specific factors 
including prescribed criteria to determine if the 1-hour average HCl-
equivalent emission rate limit may be exceeded absent an hourly rolling 
average limit on chlorine feedrate. If the 1-hour average HCl-
equivalent emission rate limit may be exceeded, you must establish an 
hourly rolling average feedrate limit on chlorine.
---------------------------------------------------------------------------

    \23\ See discussion below in Section F regarding the requirement 
to establish chlorine feedrate limits.
---------------------------------------------------------------------------

    You must calculate the 1-hour average HCl-equivalent emission rate 
from the total chlorine emission rate you select for each source.
    You must establish the 1-hour average HCl-equivalent emission rate 
limit for each affected source using either a look-up table analysis or 
site-specific analysis. Look-up tables are provided for 1-hour average 
HCl-equivalent emission rate limits as Table 3 and Table 4 to this 
section. Table 3 provides limits for facilities located in flat 
terrain. Table 4 provides limits for facilities located in simple 
elevated terrain. You must use the Tables to establish emission rate 
limits in the same manner as you use Tables 1 and 2 to establish annual 
average HCl-equivalent emission rate limits.
    If you conduct a site-specific analysis to establish a 1-hour 
average HCl-equivalent emission rate limit, you must follow the risk 
assessment procedures you used to establish an annual average HCl-
equivalent emission rate limit. The 1-hour HCl-equivalent emission rate 
limit, however, is the emission rate than ensures that the Hazard Index 
associated with maximum 1-hour average exposures is not greater than 
1.0.
    You must consider criteria including the following to determine if 
a source may exceed the 1-hour HCl-equivalent emission rate limit 
absent an hourly rolling average chlorine feedrate limit: (1) The ratio 
of the 1-hour average HCl-equivalent emission rate based on the total 
chlorine emission rate you select for each hazardous waste combustor to 
the 1-hour average HCl-equivalent emission rate limit for the 
combustor; and (2) the potential for the source to vary total chlorine 
and chloride feedrates substantially over the averaging period for the 
feedrate limit you establish to ensure compliance with the annual 
average HCl-equivalent emission rate limit.
    If you determine that a source may exceed the 1-hour average HCl-
equivalent emission rate limit, you must establish an hourly rolling 
average chlorine feedrate limit as discussed below in Section G.
    You must include the following information in your eligibility 
demonstration to document your determination whether an hourly rolling 
average feedrate limit is needed to maintain compliance with the 1-hour 
HCl-equivalent emission rate limit: (1) Determination of the Cl2/HCl 
volumetric ratio established for 1-hour average HCl-equivalent emission 
rate determinations as provided by Sec.  63.1215(b)(6)(ii); (2) 
determination of the 1-hour average HCl-equivalent emission rate 
calculated from the total chlorine emission rate you select for the 
combustor; (3) determination of the 1-hour average HCl-equivalent 
emission rate limit; (4) determination of the ratio of the 1-hour 
average HCl-equivalent emission rate to the 1-hour HCl-equivalent 
emission rate limit for the combustor; and (5) determination of the 
potential for the source to vary chlorine feedrates substantially over 
the averaging period for the long-term feedrate limit (i.e., 12-hours, 
or up to annually) established to maintain compliance with the annual 
average HCl-equivalent emission rate limit.

E. Review and Approval of Eligibility Demonstrations

    The permitting authority will review and approve your eligibility 
demonstration. Your eligibility demonstration must contain, at a 
minimum, the information listed in Sec.  63.1215(d)(1).
1. Review and Approval for Existing Sources
    If you operate an existing source, you must submit the eligibility 
demonstration to your permitting authority for review and approval not 
later than 12 months prior to the compliance date. You must also submit 
a separate copy of the eligibility demonstration to: U.S. EPA, Risk and 
Exposure Assessment Group, Emission Standards Division (C404-01), Attn: 
Group Leader, Research Triangle Park, North Carolina 27711, electronic 
mail address <a href="/cdn-cgi/l/email-protection#590b1c181e193c2938773e362f"><span class="__cf_email__" data-cfemail="6331262224230613024d040c15">[email protected]</span></a>.
    Your permitting authority should notify you of approval or intent 
to disapprove your eligibility demonstration within 6 months after 
receipt of the original demonstration, and within 3 months after 
receipt of any supplemental information that you submit. A notice of 
intent to disapprove your eligibility demonstration will identify 
incomplete or inaccurate information or noncompliance with prescribed 
procedures and specify how much time you will have to submit additional 
information or to comply with the MACT total chlorine standards. If 
your eligibility demonstration is disapproved, the permitting authority 
may extend the compliance date of the total chlorine standard to allow 
you to make changes to the design or operation of the combustor or 
related systems as quickly as practicable to enable you to achieve 
compliance with the MACT standard for total chlorine.
    If your permitting authority has not approved your eligibility 
demonstration by the compliance date, and has not issued a notice of 
intent to disapprove your demonstration, you may nonetheless begin 
complying, on the compliance date, with the annual average HCl-
equivalent emission rate limits you present in your eligibility 
demonstration.
    If your permitting authority issues a notice of intent to 
disapprove your eligibility demonstration after the

[[Page 59416]]

compliance date, the authority will identify the basis for that notice 
and specify how much time you will have to submit additional 
information or to comply with the MACT total chlorine standards. The 
permitting authority may extend the compliance date of the total 
chlorine standard to allow you to make changes to the design or 
operation of the combustor or related systems as quickly as practicable 
to enable you to achieve compliance with the MACT standard for total 
chlorine.
2. Review and Approval for New and Reconstructed Sources
    The procedures for review and approval of eligibility 
demonstrations applicable to existing sources discussed above also 
apply to new or reconstructed sources, except that the date you must 
submit the eligibility demonstration is as discussed below.
    If you operate a new or reconstructed source that starts up by 
April 12, 2007, or a solid fuel-fired boiler or liquid fuel-fired 
boiler that is an area source that increases its emissions or its 
potential to emit such that it becomes a major source of HAP before 
April 12, 2007, you must either: (1) Submit an eligibility 
demonstration for review and approval by April 12, 2006 and comply with 
the HCl-equivalent emission rate limits and operating requirements you 
establish in the eligibility demonstration; or (2) comply with the 
final total chlorine emission standards under Sec. Sec.  63.1216, 
63.1217, 63.1219, 63.1220, and 63.1221, by October 12, 2005, or upon 
startup, whichever is later, except for a standard that is more 
stringent than the standard proposed on April 20, 2004 for your source. 
If a final standard is more stringent than the proposed standard, you 
may comply with the proposed standard until October 14, 2008, after 
which you must comply with the final standard.
    If you operate a new or reconstructed source that starts up on or 
after April 12, 2007, or a solid fuel-fired boiler or liquid fuel-fired 
boiler that is an area source that increases its emissions or its 
potential to emit such that it becomes a major source of HAP on or 
after April 12, 2007, you must comply with either of the following. You 
may submit an eligibility demonstration for review and approval 12 
months prior to startup. Alternatively, you may comply with the final 
total chlorine emission standards under Sec. Sec.  63.1216, 63.1217, 
63.1219, 63.1220, and 63.1221 upon startup. If the final standard is 
more stringent than the standard proposed for your source on April 20, 
2004, however, and if you start operations before October 14, 2008, you 
may comply with the proposed standard until October 14, 2008, after 
which you must comply with the final standard.

F. Testing Requirements

    You must comply with the requirements for comprehensive performance 
testing under Sec.  63.1207.
1. Test Methods for Stack Gas Containing Alkaline Particulate
    If you operate a cement kiln or a combustor equipped with a dry 
acid gas scrubber, you must use EPA Method 320/321 or ASTM D 6735-01, 
or an equivalent method, to measure hydrogen chloride, and the back-
half (caustic impingers) of Method 26/26A, or an equivalent method, to 
measure chlorine.
2. Test Methods for Stack Gas Containing High Levels of Bromine or 
Sulfur
    If you operate an incinerator, boiler, or lightweight aggregate 
kiln and your feedstreams contain bromine or sulfur during the 
comprehensive performance test at the levels indicated below, you must 
use EPA Method 320/321 or ASTM D 6735'01, or an equivalent method, to 
measure hydrogen chloride, and Method 26/26A, or an equivalent method, 
to measure chlorine and hydrogen chloride combined. You must determine 
your chlorine emissions to be the higher of: (1) The value measured by 
Method 26/26A, or an equivalent method; or (2) the value calculated by 
the difference between the combined hydrogen chloride and chlorine 
levels measured by Method 26/26a, or an equivalent method, and the 
hydrogen chloride measurement from EPA Method 320/321 or ASTM D 6735-
01, or an equivalent method.
    These procedures apply if you feed during the comprehensive 
performance test bromine at a bromine/chlorine ratio in feedstreams 
greater than 5 percent by mass, or sulfur at a sulfur/chlorine ratio in 
feedstreams greater than 50 percent by mass.\24\
---------------------------------------------------------------------------

    \24\ USEPA, ``Technical Support Document for HWC MACT Standards, 
Volume IV: Compliance with the HWC MACT Standards,'' September 2005, 
Chapter 15.1.2.
---------------------------------------------------------------------------

    Finally, you should precondition the M26/26A filter for one hour 
prior to beginning the performance test to minimize the potential for a 
low bias caused by adsorption/absorption of hydrogen chloride on the 
filter.

G. Monitoring Requirements

    You must establish and comply with limits on the same operating 
parameters that apply to sources complying with the MACT standard for 
total chlorine under Sec.  63.1209(o), except that feedrate limits on 
total chlorine and chloride must be established as described below.
1. Feedrate Limit to Ensure Compliance with the Annual Average HCl-
Equivalent Emission Rate Limit
    For sources subject to the feedrate limit for total chlorine and 
chloride under Sec.  63.1209(n)(4) to ensure compliance with the 
semivolatile metals standard, the feedrate limit (and averaging period) 
for total chlorine and chloride to ensure compliance with the annual 
average HCl-equivalent emission rate limit is the same as required by 
that paragraph. Thus, the chlorine feedrate limit is the average of the 
run averages during the comprehensive performance test, and is 
established as a 12-hour rolling average.
    That chlorine feedrate limit cannot exceed the numerical value 
(i.e., not considering the averaging period) of the feedrate limit that 
ensures compliance with the annual average HCl-equivalent emission rate 
limit, however. Therefore, the numerical value of the total chlorine 
and chloride feedrate limit must not exceed the value you calculate as 
the annual average HCl-equivalent emission rate limit (lb/hr) divided 
by [1 - system removal efficiency]. You must calculate a total chlorine 
system removal efficiency for each test run of the comprehensive 
performance test as [1 - total chlorine emission rate (g/s)/chlorine 
feedrate (g/s)], and calculate the average system removal efficiency of 
the test run averages. If your source does not control total chlorine, 
you must assume zero system removal efficiency. If emissions during the 
comprehensive performance test exceed the annual average HCl-equivalent 
emission rate limit, eligibility for the health-based emission limits 
is not affected. This is because the emission rate limit is an annual 
average limit. Compliance is based on a 12-hour rolling average 
chlorine feedrate limit (rather than an (up to) an annual averaging 
period) for sources subject to the 12-hour rolling average feedrate 
limit for total chlorine and chloride under Sec.  63.1209(n)(4) to 
ensure compliance with the semivolatile metals standard given that the 
more stringent feedrate limit (i.e., the feedrate limit with the 
shorter averaging period) would apply.
    For sources exempt from the feedrate limit for total chlorine and 
chloride under Sec.  63.1209(n)(4) because they comply with Sec.  
63.1207(m)(2) (which allows compliance with the semivolatile metals 
emission standard absent emissions testing by assuming all metals fed 
are emitted), the feedrate limit for total chlorine and chloride to 
ensure

[[Page 59417]]

compliance with the annual average HCl-equivalent emission rate must be 
established as follows:
    <bullet> You must establish an average period for the feedrate 
limit that does not exceed an annual rolling average;
    <bullet> You must calculate a total chlorine system removal 
efficiency for each test run of the comprehensive performance test as 
[1 - total chlorine emission rate (g/s)/chlorine feedrate (g/s)], and 
calculate the average system removal efficiency of the test run 
averages. If your source is not equipped with a control system that 
consistently and reproducibly controls total emissions (e.g., wet or 
dry scrubber), you must assume zero system removal efficiency. If 
emissions during the comprehensive performance test exceed the annual 
average HCl-equivalent emission rate limit, eligibility for emission 
limits under this section is not affected. The emission rate limit is 
an annual average limit and compliance is based on an annual average 
feedrate limit on total chlorine and chloride (or a shorter averaging 
period if you so elect under paragraph (g)(2)(ii)(A) of this section); 
and
    <bullet> You must calculate the feedrate limit for total chlorine 
and chloride as the annual average HCl-equivalent emission rate limit 
(lb/hr) divided by [1 - system removal efficiency] and comply with the 
feedrate limit on the averaging period you establish.
2. Feedrate Limit To Ensure Compliance With the 1-Hour Average HCl-
Equivalent Emission Rate Limit
    You must establish an hourly rolling average feedrate limit on 
total chlorine and chloride to ensure compliance with the 1-hour 
average HCl-equivalent emission rate limit unless you determine that 
the hourly rolling average feedrate limit is waived as discussed under 
Section D above. If required, you must calculate the hourly rolling 
average feedrate limit for total chlorine and chloride as the 1-hour 
average HCl-equivalent emission rate limit (lb/hr) divided by [1 - 
system removal efficiency] using the system removal efficiency 
demonstrated during the comprehensive performance test.

H. Relationship Among Emission Rates, Emission Rate Limits, and 
Feedrate Limits

    We summarize here the relationship among: (1) the total chlorine 
emission rate you select in your eligibility demonstration; (2) the 
annual average and 1-hour average HCl-equivalent emission rates you 
present in your eligibility demonstration; (3) the annual average and 
1-hour average emission rate limits you present in your eligibility 
demonstration; (4) performance test emission rates for total chlorine 
and HCl-equivalent emissions; and (5) long-term and hourly rolling 
average chlorine feedrate limits.
1. Total Chlorine Emission Rate, Annual Average HCl-Equivalent Emission 
Rate, and Annual Average HCl-Equivalent Emission Rate Limit
    For the eligibility demonstration, you must select a total chlorine 
emission concentration (ppmv) for each combustor, determine the 
Cl<INF>2</INF>/HCl volumetric ratio, calculate the annual average HCl-
equivalent emission rate (lb/hr), and document that the emission rate 
does not exceed the annual average HCl-equivalent emission rate limit.
    You select a total chlorine (i.e., HCl and chlorine combined) 
emission concentration (ppmv) for each hazardous waste combustor 
expressed as chloride (Cl<SUP>(-)</SUP>) equivalent. For incinerators, 
cement kilns, and lightweight aggregate kilns, this emission 
concentration cannot exceed the Interim Standards for total chlorine. 
You then determine the average Cl<INF>2</INF>/HCl volumetric ratio 
considering all historical regulatory emissions tests and apportion 
total chlorine emissions between Cl<INF>2</INF> and HCl accordingly. 
You use these apportioned volumetric emissions to calculate the 
Cl<INF>2</INF> and HCl emission rates (lb/hr) using the average gas 
flowrate (and other relevant parameters) for the most recent RCRA 
compliance test or MACT performance test for total chlorine. Finally, 
you use these Cl<INF>2</INF> and HCl emission rates to calculate an 
annual average HCl-equivalent emission rate, which cannot exceed the 
annual average HCl-equivalent emission rate limit that you establish as 
discussed below.
    To establish the annual average HCl-equivalent emission rate limit, 
you may either use Tables 1 or 2 in Sec.  63.1215 to look-up the limit, 
or conduct a site-specific risk analysis. Under the site-specific risk 
analysis option, the annual average HCl-equivalent emission rate limit 
would be the highest emission rate that the risk assessment estimates 
would result in a Hazard Index not exceeding 1.0 for the actual 
individual most exposed to the facility's emissions considering off-
site locations where people reside and where people congregate for 
work, school, or recreation.
    If you have more than one on-site hazardous waste combustor, and if 
you use the look-up tables to establish the annual average HCl-
equivalent emission rate limits, the sum of the ratios for all 
combustors of the annual average HCl-equivalent emission rate to the 
annual average HCl-equivalent emission rate limit cannot not exceed 
1.0. This will ensure that the RfC-based Hazard Index of 1.0 is not 
exceeded, a principle criterion of the eligibility demonstration.
    If you use site-specific risk analysis to demonstrate that a Hazard 
Index of 1.0 is not exceeded, you would generally identify for each 
combustor the maximum annual average HCl-equivalent emission rate that 
the risk assessment estimates would result in an RfC-based Hazard Index 
of 1.0 at any off-site receptor location (i.e., considering locations 
where people reside and where people congregate for work, school, or 
recreation.\25\ This emission rate would be the annual average HCl-
equivalent emission rate limit for each combustor.
---------------------------------------------------------------------------

    \25\ Note again, however, that the total chlorine emission 
concentration (ppmv) is capped by the Interim Standards for 
incinerators, cement kilns, and lightweight aggregate kilns.
---------------------------------------------------------------------------

2. 1-Hour Average HCl-Equivalent Emission Rate and Emission Rate Limit
    As discussed in Section D above, you must determine in your 
eligibility demonstration whether the 1-hour HCl-equivalent emission 
rate limit may be exceeded absent an hourly rolling average chlorine 
feedrate limit. To make this determination, you must establish a 1-hour 
average HCl-equivalent emission rate and a 1-hour average HCl-
equivalent emission rate limit.
    You calculate the 1-hour average HCl-equivalent emission rate from 
the total chlorine emission rate, established as discussed above, using 
the equation in Sec.  63.1215(b)(3).
    You establish the 1-hour average HCl-equivalent emission rate limit 
by either using Tables 3 or 4 in Sec.  63.1215 to look-up the limit, or 
conducting a site-specific risk analysis. Under the site-specific risk 
analysis option, the 1-hour average HCl-equivalent emission rate limit 
would be the highest emission rate that the risk assessment estimates 
would result in an aREL-based Hazard Index not exceeding 1.0 at any 
off-site receptor location (i.e., considering locations where people 
reside and where people congregate for work, school, or recreation).
3. Performance Test Emissions
    During the comprehensive performance test, you must demonstrate a 
system removal efficiency for total chlorine as [1 - TCl emitted (lb/
hr)/chlorine fed (lb/hr)]. During the test, however, the total chlorine 
emission rate you select for each combustor and the annual average HCl-
equivalent

[[Page 59418]]

emission rate limit can exceed the levels you present in the 
eligibility demonstration. This is because those emission rates are 
annual average rates and need not be complied with over the duration of 
three runs of the performance test, which may be nominally only 3 
hours.
    The 1-hour average HCl-equivalent emission rate limit cannot be 
exceeded during any run of the comprehensive performance test, however. 
This limit is based on an aREL Hazard Index of 1.0; an exceedance of 
the limit over a test run with a nominal 1-hour duration would result 
in a Hazard Index of greater than 1.0.
4. Chlorine Feedrate Limits
    To maintain compliance with the annual average HCl-equivalent 
emission rate limit, you must establish a long-term average chlorine 
feedrate limit. In addition, if you determine under Sec.  63.1205(d)(3) 
that the 1-hour average HCl-equivalent emission rate may be exceeded 
(i.e., because your chlorine feedrate may vary substantially over the 
averaging period for the long-term chlorine feedrate limit), you must 
establish an hourly rolling average chlorine feedrate limit.
    Long-Term Chlorine Feedrate Limit. The chlorine feedrate limit to 
maintain compliance with the annual average HCl-equivalent emission 
rate is either: (1) The chlorine feedrate during the comprehensive 
performance test if you demonstrate compliance with the semivolatile 
metals emission standard during the test (see Sec.  63.1209(o)); or (2) 
if you comply with the semivolatile metals emission standard under 
Sec.  63.1207(m)(2) by assuming all metals in the feed to the combustor 
are emitted, the HCl-equivalent emission rate limit divided by [1 - 
system removal efficiency] where you demonstrate the system removal 
efficiency during the comprehensive performance test.
    If you establish the chlorine feedrate limit based on the feedrate 
during the performance test to demonstrate compliance with the 
semivolatile metals emission standard, the averaging period for the 
feedrate limit is a 12-hour rolling average. If you establish the 
chlorine feedrate limit based on the system removal efficiency during 
the performance test, the averaging period is up to an annual rolling 
average. See discussion in Part Four, Section VII.B of this preamble.
    If you comply with the semivolatile metals emission standard under 
Sec.  63.1207(m)(2), however, the long-term chlorine feedrate limit is 
based on the system removal efficiency during the comprehensive 
performance test rather than the feedrate during the performance test. 
This is because the averaging period for this chlorine feedrate limit 
(that ensures compliance with the annual average HCl-equivalent 
emission rate limit) is up to an annual rolling average. See Sec.  
63.1215(g)(2). Thus, the chlorine feedrate, and total chlorine 
emissions, can be higher than the limit during the relatively short 
duration of the comprehensive performance tests.
    Hourly Rolling Average Chlorine Feedrate Limit. If you determine 
under Sec.  63.1205(d)(3) that the 1-hour average HCl-equivalent 
emission rate limit may be exceeded, you must establish an hourly 
rolling average chlorine feedrate limit. That feedrate limit is 
established as the 1-hour HCl-equivalent emission rate limit divided by 
[1 - system removal efficiency]. The hourly rolling average chlorine 
feedrate limit is not established based on feedrates during the 
performance test because performance test feedrates may be 
substantially lower than the feedrate needed to ensure compliance with 
the 1-hour average HCl-equivalent emission rate. Note, however, that 
the hourly rolling average feedrate limit cannot be exceeded during any 
run of the comprehensive performance test. This chlorine feedrate limit 
is based on the 1-hour average HCl-equivalent emission rate limit, 
which is based on an aREL Hazard Index of 1.0. Thus, an exceedance of 
the hourly rolling average feedrate limit (and the 1-hour lHCl-
equivalent emission rate limit) over a test run with a nominal 1-hour 
duration would result in a Hazard Index of greater than 1.0.

I. Changes

    Your requirements will change in response to changes that affect 
the HCl-equivalent emission rate or HCl-equivalent emission rate limit 
for a source.
1. Changes Over Which You Have Control
    Changes That Affect HCl-Equivalent Emission Rate Limits. If you 
plan to change the design, operation, or maintenance of the facility in 
a manner that would decrease the annual average or 1-hour average HCl-
equivalent emission rate limit (e.g., reduce the distance to the 
property line; reduce stack gas temperature; reduce stack height), 
prior to the change you must submit to the permitting authority a 
revised eligibility demonstration documenting the lower emission rate 
limits and calculations of reduced total chlorine and chloride feedrate 
limits.
    If you plan to change the design, operation, or maintenance of the 
facility in a manner than would increase the annual average or 1-hour 
average HCl-equivalent emission rate limit, and you elect to increase 
your total chlorine and chloride feedrate limits, prior to the change 
you must submit to the permitting authority a revised eligibility 
demonstration documenting the increased emission rate limits and 
calculations of the increased feedrate limits prior to the change.
    Changes That Affect System Removal Efficiency. If you plan to 
change the design, operation, or maintenance of the combustor in a 
manner than could decrease the system removal efficiency, you are 
subject to the requirements of Sec.  63.1206(b)(5) for conducting a 
performance test to reestablish the combustor's system removal 
efficiency. You also must submit a revised eligibility demonstration 
documenting the lower system removal efficiency and the reduced 
feedrate limits on total chlorine and chloride.
    If you plan to change the design, operation, or maintenance of the 
combustor in a manner than could increase the system removal 
efficiency, and you elect to document the increased system removal 
efficiency to establish higher feedrate limits on total chlorine and 
chloride, you are subject to the requirements of Sec.  63.1206(b)(5) 
for conducting a performance test to reestablish the combustor's system 
removal efficiency. You must also submit a revised eligibility 
demonstration documenting the higher system removal efficiency and the 
increased feedrate limits on total chlorine and chloride.
2. Changes Over Which You Do Not Have Control
    If you use site-specific risk assessment in lieu of the look-up 
tables to establish the HCl-equivalent emission rate limit, you must 
review the documentation you use in your eligibility demonstration 
every five years from the date of the comprehensive performance test 
and submit for review and approval with the comprehensive performance 
test plan either a certification that the information used in your 
eligibility demonstration has not changed in a manner that would 
decrease the annual average HCl-equivalent emission rate limit, or a 
revised eligibility demonstration. Examples of changes beyond your 
control that may decrease the annual average HCl-equivalent emission 
rate limit (or 1-hour average HCl-equivalent emission rate limit) are 
construction of residences at a location exposed to higher ambient

[[Page 59419]]

concentrations than evaluated during your previous risk analysis, or a 
reduction in the RfCs or aRELs.
    If, in the interim between the dates of your comprehensive 
performance tests, you have reason to know of changes that would 
decrease the annual average HCl-equivalent emission rate limit, you 
must submit a revised eligibility demonstration as soon as practicable 
but not more frequently than annually.
    If you determine that you cannot demonstrate compliance with a 
lower annual average HCl-equivalent emission rate limit (dictated by a 
change over which you do not have control) during the comprehensive 
performance test because you need additional time to complete changes 
to the design or operation of the source or related systems, you may 
request that the permitting authority grant you additional time to make 
those changes as quickly as practicable.

X. Overview on Floor Methodologies

    The most contentious issue in the rulemaking involved methodologies 
for determining MACT floors, namely, which sources are best performing, 
and what is their level of performance. Superficially, these questions 
have a ready answer: the best performers are the lowest emitters as 
measured by compliance tests, and those tests fix their level of 
performance. But compliance tests are snapshots which do not fully 
capture sources' total operating variability. Since the standards must 
be met at all times, picking lowest compliance test data to set the 
standard results in standards best performing sources themselves would 
be unable to meet at all times.
    To avoid this impermissible result, EPA selected approaches that 
reasonably estimate best performing sources' total variability. Certain 
types of variability can be quantified statistically, and EPA did so 
here (using standard statistical approaches) in all of the floor 
methodologies used in the rule. There are other components of 
variability, however, which cannot be fully quantified, but nonetheless 
must be accounted for in reasonably estimating best performing sources' 
performance over time. EPA selected ranking methodologies which best 
account for this total variability.
    Where control of the feed of HAP is feasible and technically 
assessable (the case for HAP metals and for total chlorine), EPA used a 
methodology that ranked sources by their ability to best control both 
HAP feed and HAP emissions. This methodology thus assesses the 
efficiency of control of both the HAP inputs to a hazardous waste 
combustion unit, and the efficiency of control of the unit's outputs. 
This methodology reasonably selects the best performing (and for new 
sources, best controlled) sources, and reasonably assesses their level 
of performance. When HAP feed control is not feasible, notably where 
HAP is contributed by raw material and fossil fuel inputs, EPA 
determined best performers and their level of performance using a 
methodology that selects the lowest emitters using the best air 
pollution control technology. This methodology reasonably estimates the 
best performing sources' level of performance, and better accounts for 
total variability in emissions levels of the best performing sources.
    EPA carefully examined approaches selecting lowest emitters as best 
performers. Examination of other test conditions from the same best 
performing sources shows, however, that this approach results in 
standards not achievable even by the best performers. Indeed, in order 
to meet such standards, even ``best performing'' sources (lowest 
emitting in individual tests) would have to add additional air 
pollution control technology. EPA views this result as an end run 
around the section 112(d)(2) beyond-the-floor process, because floor 
standards would force industry-wide technological changes without 
consideration of the factors (cost and energy in particular) which 
Congress mandated for consideration when establishing beyond-the-floor 
standards.

Part Three: What Are the Major Changes Since Proposal?

I. Database

A. Hazardous Burning Incinerators

    Five incinerators have been removed from the database because they 
have initiated or completed RCRA closure.\26\ Two incinerators have 
been added to the list of sources used to calculate the floor 
levels.\27\ Emissions data from source 3015 has been excluded for 
purposes of calculating the particulate matter floor because the source 
was processing an atypical waste stream from a particulate matter 
compliance perspective. See part four, section I.F. We have excluded 
the most recent mercury and dioxin/furan emissions data from source 
327, and have instead used data from an older test condition to 
represent this source's emissions because the source encountered 
problems with its carbon injection system during the most recent test. 
See part four, section I.F. Emissions data from source 3006 has been 
excluded for purposes of calculating the semivolatile metal standard 
because this source did not measure cadmium emissions during its 
emissions test. See part four, section I.F. We have added mercury 
emissions data from source 901 (DSSI) to the incinerator mercury 
database because this source (which is otherwise subject to standards 
for liquid fuel boilers) is burning a waste which is unlike that burned 
by any other liquid fuel boiler with respect to mercury concentration 
and waste provenance, but typical of waste burned by incinerators with 
respect to those factors. See part four, section VI.D.1. This change 
correspondingly affects the liquid fuel boiler standard by removing 
that data from the liquid fuel boiler database.
---------------------------------------------------------------------------

    \26\ See ``Final Technical Support Document for HWC MACT 
Standards, Volume II: HWC Database'' for a list of the sources that 
have initiated or completed RCRA closure.
    \27\ We noticed the data from these sources but did not include 
them in the MACT standard calculations at proposal. Note that 
inclusion of these sources did not affect any of the calculated MACT 
standards. See ``Final Technical Support Document for HWC MACT 
Standards, Volume II: HWC Database'' for more discussion.
---------------------------------------------------------------------------

B. Hazardous Waste Cement Kilns

1. Use of Emissions Data From Ash Grove Cement Company
    The emissions data from Ash Grove Cement Company, which operates a 
recently constructed preheater/precalciner kiln located in Chanute, 
Kansas, are considered when calculating MACT floors for new hazardous 
waste burning cement kilns. In the proposal, we did not consider their 
emissions data in the floor analyses for existing sources because Ash 
Grove Cement used the data to demonstrate compliance with the new 
source interim standards, and did not address the data for purposes of 
new source standards. See 69 FR at 21217 n. 35. Consistent with our 
position on use of post-1999 emissions data, we are including Ash Grove 
Cement's emissions data in the floor analyses for new sources. See also 
Part Four, Section I.B of the preamble.
2. Removal of Holcim's Emissions Data From EPA's HWC Data Base
    Following cessation of hazardous waste operations in 2003, we are 
removing all emissions data from both wet process cement kilns at 
Holcim's Holly Hill, South Carolina, plant from our hazardous waste 
combustor data base. This is consistent with our approach in both this 
rule and the 1999 rule to base the standards only on performance of 
sources that actually are operating (i.e., burning hazardous waste). 
See also Part Four, Section I.A and 64 FR at 52844.

[[Page 59420]]

3. Use of Mercury Data
    As discussed below, we are using a commenter-submitted dataset as 
the basis of the mercury standards for existing and new cement kilns. 
This comprehensive dataset documents the day-to-day levels of mercury 
in hazardous waste fired to all cement kilns for a three year period 
covering 1999 to 2001. We have determined that the commenter-submitted 
data are more representative than data used at proposal. See Part Four, 
Section I.D of the preamble for our rationale.

C. Hazardous Waste Lightweight Aggregate Kilns

    We are incorporating mercury data submitted by a commenter into the 
MACT floor analysis for existing and new lightweight aggregate kilns. 
These data document the day-to-day levels of mercury in hazardous waste 
fired to lightweight aggregate kilns located at Solite Corporation's 
Arvonia plant between October 2003 and June 2004. We have determined 
that the commenter-submitted data are more representative than the data 
used at proposal. See Part Four, Section I.E of the preamble for our 
rationale.

D. Liquid Fuel Boilers

    In the proposed rule, we classified liquid fuel boilers as one 
category. The final rule classifies them into two for purposes of the 
mercury, semivolatile metals, chromium, and total chlorine standards: 
one for liquid fuel boilers burning lower heating value hazardous waste 
(hazardous waste with a heating value less than 10,000 Btu/lb), and 
another for liquid fuel boilers burning higher heating value hazardous 
waste (hazardous waste with a heating value of 10,000 Btu/lb or 
greater).
    We also made other, minor changes to the data base because some 
sources have initiated closure, were misclassified as other sources in 
the proposed rule, or were inadvertently not considered in the floor 
calculations although the sources' test reports were in the docket at 
proposal.

E. HCl Production Furnaces

    Six of the 17 hydrochloric acid production furnaces have ceased 
burning hazardous waste since proposal. Consequently, we do not use 
emissions data from these sources to establish the final standards. All 
six of these sources were equipped with waste heat recovery boilers and 
had relatively high dioxin/furan emissions. In addition, we 
reclassified source <greek-i>2020 as a boiler based on comments 
received at proposal.

F. Total Chlorine Emissions Data Below 20 ppmv

    We corrected all the total chlorine measurements in the data base 
that were below 20 ppmv to account for potential systemic negative 
biases in the Method 0050 data in response to comments on the proposed 
rule. See the discussion in Part Four, Section I.C.1 below.
    To account for the bias, we corrected all total chlorine emissions 
data that were below 20 ppmv to 20 ppmv. We accounted for within-test 
condition emissions variability for the corrected data by imputing a 
standard deviation that is based on a regression analysis of run-to-run 
standard deviation versus emission concentration for all data above 20 
ppmv. This approach of using a regression analysis to impute a standard 
deviation is similar to the approach we used to account for total 
variability (i.e., test-to-test and within test variability) of PM 
emissions for sources that use fabric filters.

II. Emission Limits

A. Incinerators

    The changes in the incinerator standards for existing sources since 
proposal are:

------------------------------------------------------------------------
          Standard               Proposed limit          Final limit
------------------------------------------------------------------------
Dioxin/Furans (ng TEQ/dscm).  Sources with dry air  For all sources,
                               pollution control     0.20 or 0.40 and
                               systems or waste      temperature control
                               heat boilers: 0.28;   < 400 [deg]F at the
                               For others: 0.2 or    air pollution
                               0.4 and temperature   control device
                               control at inlet of   inlet.
                               air pollution
                               control device <
                               400 [deg]F.
Particulate Matter (gr/dscf)  0.015...............  0.013.
Semivolatile Metals ([mu]g/   59..................  230.
 dscm).
Low Volatile Metals ([mu]g/   84..................  92.
 dscm).
Total Chlorine (ppmv).......  1.5.................  32.
Alternative to the            59..................  230.
 particulate matter
 standard: Combined
 emissions of lead, cadmium
 and selenium ([mu]g/dscm).
Alternative to the            84..................  92.
 particulate matter
 standard: Combined
 emissions of arsenic,
 berrylium, chrome,
 antimony, cobalt,
 manganese, and nickel
 ([mu]g/dscm).
------------------------------------------------------------------------

    The changes in the incinerator standards for new sources since 
proposal are:

------------------------------------------------------------------------
                                                   Proposed      Final
                    Standard                         limit       limit
------------------------------------------------------------------------
Particulate Matter (gr/dscf)....................      0.0007      0.0015
Mercury ([mu]g/dscm)............................      8.0         8.1
Semivolatile Metals ([mu]g/dscm)................      6.5        10
Low Volatile Metals ([mu]g/dscm)................      8.9        23
Total Chlorine (ppmv)...........................      0.18       21
Alternative to the particulate matter standard:       6.5        10
 Combined emissions of lead, cadmium and
 selenium ([mu]g/dscm)..........................
Alternative to the particulate matter standard:       8.9        23
 Combined emissions of arsenic, berrylium,
 chrome, antimony, cobalt, manganese, and nickel
 ([mu]g/dscm)...................................
------------------------------------------------------------------------


[[Page 59421]]

Hazardous Waste Burning Cement Kilns

    The changes in the standards for existing cement kiln since 
proposal are:

------------------------------------------------------------------------
          Standard               Proposed limit          Final limit
------------------------------------------------------------------------
Mercury ([mu]g/dscm)........  64 1................  Both 3.0 ppmw 2 and
                                                     either 120 [mu]g/
                                                     dscm (stack
                                                     emissions) or 120
                                                     [mu]g/dscm
                                                     (expressed as a
                                                     hazardous waste
                                                     MTEC) 3.
Particulate matter..........  0.028 gr/dscf.......  0.028 gr/dscf and
                                                     20% opacity 4.
Semivolatile metals.........  4.0E-04 lb/MMBtu 5..  7.6E-04 lb/MMBtu 5
                                                     and 330 [mu]g/dscm.
Low volatile metals.........  1.4E-05 lb/MMBtu 5..  2.1E-05 lb/MMBtu 5
                                                     and 56 [mu]g/dscm.
Total chlorine (ppmv) 6.....  110.................  120.
------------------------------------------------------------------------
1 The proposed mercury standard was an annual limit.
2 Feed concentration of mercury in hazardous waste as-fired.
3 HW MTEC means maximum theoretical emissions concentration of the
  hazardous waste and MTEC is defined at Sec.   63.1201(a).
4 The opacity standard does not apply to a source equipped with a bag
  leak detection system under Sec.   63.1206(c)(8) or a particulate
  matter detection system under Sec.   63.1206(c)(9).
5 Standard is expressed as mass of pollutant stack emissions
  attributable to the hazardous waste per million British thermal unit
  heat input of the hazardous waste.
6 Combined standard, reported as a chloride (Cl(-)) equivalent.

    The changes in the standards for new cement kilns since proposal 
are:

------------------------------------------------------------------------
          Standard               Proposed limit          Final limit
------------------------------------------------------------------------
Mercury ([mu]g/dscm)........  35 \1\..............  Both 1.9 ppmw 2 and
                                                     either 120 [mu]g/
                                                     dscm (stack
                                                     emissions) or 120
                                                     [mu]g/dscm
                                                     (expressed as a
                                                     hazardous waste
                                                     MTEC) 3.
Particulate matter..........  0.0058 gr/dscf......  0.0023 gr/dscf and
                                                     20% opacity 4.
Semivolatile metals.........  6.2E-05 lb/MMBtu 5..  6.2E-05 lb/MMBtu 5
                                                     and 180 [mu]g/dscm.
Low volatile metals.........  1.4E-05 lb/MMBtu 5..  1.5E-05 lb/MMBtu 5
                                                     and 54 [mu]g/dscm.
Total chlorine (ppmv) 6.....  78..................  86.
------------------------------------------------------------------------
1 The proposed mercury standard was an annual limit.
2 Feed concentration of mercury in hazardous waste as-fired.
3 HW MTEC means maximum theoretical emissions concentration of the
  hazardous waste and MTEC is defined at Sec.   63.1201(a).
4 The opacity standard does not apply to a source equipped with a bag
  leak detection system under Sec.   63.1206(c)(8) or a particulate
  matter detection system under Sec.   63.1206(c)(9).
5 Standard is expressed as mass of pollutant stack emissions
  attributable to the hazardous waste per million British thermal unit
  heat input of the hazardous waste.
6 Combined standard, reported as a chloride (Cl(-)) equivalent.

C. Hazardous Waste Burning Lightweight Aggregate Kilns

    The changes in the standards for existing lightweight aggregate 
kilns since proposal are:

------------------------------------------------------------------------
          Standard               Proposed limit          Final limit
------------------------------------------------------------------------
Dioxins and furans (ng TEQ/   0.40................  0.20 or rapid quench
 dscm).                                              of the flue gas at
                                                     the exit of the
                                                     kiln to less than
                                                     400 [deg]F.
Mercury ([mu]g/dscm)........  67 1................  120 [mu]g/dscm
                                                     (stack emissions)
                                                     or 120 [mu]g/dscm
                                                     (expressed as a
                                                     hazardous waste
                                                     MTEC) 2.
Semivolatile metals.........  3.1E-04 lb/MMBtu 3    3.0E-04 lb/MMBtu 3
                               and 250 [mu]g/dscm.   and 250 [mu]g/dscm.
 
------------------------------------------------------------------------
1 The proposed mercury standard was an annual limit.
2 HW MTEC means maximum theoretical emissions concentration of the
  hazardous waste and MTEC is defined at Sec.   63.1201(a).
3 Standard is expressed as mass of pollutant stack emissions
  attributable to the hazardous waste per million British thermal unit
  heat input of the hazardous waste.

    The changes in the standards for new lightweight aggregate kilns 
since proposal are:

------------------------------------------------------------------------
          Standard               Proposed limit          Final limit
------------------------------------------------------------------------
Dioxins and furans (ng TEQ/   0.40................  0.20 or rapid quench
 dscm).                                              of the flue gas at
                                                     the exit of the
                                                     kiln to less than
                                                     400 [deg]F.

[[Page 59422]]

 
Particulate matter..........  0.0099 gr/dscf......  0.0098 gr/dscf.
Mercury ([mu]g/dscm)........  67 1................  120 [mu]g/dscm
                                                     (stack emissions)
                                                     or 120 [mu]g/dscm
                                                     (expressed as a
                                                     hazardous waste
                                                     MTEC) 2.
Semivolatile metals.........  2.4E-05 lb/MMBtu 3    3.7E-05 lb/MMBtu 3
                               and 43 [mu]g/dscm.    and 43 [mu]g/dscm.
------------------------------------------------------------------------
1 The proposed mercury standard was an annual limit.
2 HW MTEC means maximum theoretical emissions concentration of the
  hazardous waste and MTEC is defined at Sec.   63.1201(a).
3 Standard is expressed as mass of pollutant stack emissions
  attributable to the hazardous waste per million British thermal unit
  heat input of the hazardous waste.

D. Solid Fuel Boilers

    The changes in the solid fuel boiler standards for existing sources 
since proposal are:

------------------------------------------------------------------------
                                                     Proposed    Final
                     Standard                         limit      limit
------------------------------------------------------------------------
Mercury ([mu]g/dscm)..............................         10         11
Semivolatile Metals ([mu]g/dscm)..................        170        180
Low Volatile metals ([mu]g/dscm)..................        210        380
Alternative to the particulate matter standard:           170        180
 Combined emissions of lead, cadmium and selenium
 ([mu]g/dscm).....................................
Alternative to the particulate matter standard:           210        380
 Combined emissions of arsenic, beryllium,
 chromium, antimony, cobalt, manganese, and nickel
 ([mu]g/dscm).....................................
------------------------------------------------------------------------

    The changes in the solid fuel boiler standards for new sources 
since proposal are:

------------------------------------------------------------------------
                                                     Proposed    Final
                     Standard                         limit      limit
------------------------------------------------------------------------
Mercury ([mu]g/dscm)..............................         10         11
Semivolatile Metals ([mu]g/dscm)..................        170        180
Low Volatile metals ([mu]g/dscm)..................        210        380
Alternative to the particulate matter standard:           170        180
 Combined emissions of lead, cadmium and selenium
 ([mu]g/dscm).....................................
------------------------------------------------------------------------

E. Liquid Fuel Boilers

    We redefined the liquid fuel boiler subcategory into two separate 
boiler subcategories based on the heating value of the hazardous waste 
they burn: Those that burn waste below 10,000 Btu/lb, those that burn 
hazardous waste with a heating value of 10,000 Btu/lb or greater. See 
Part Four, Section VI.D.2 of today's preamble for a complete 
discussion.
    The additional changes to the liquid fuel boiler standards for 
existing sources since proposal are:

----------------------------------------------------------------------------------------------------------------
                                                                                   Final limit
                                                               -------------------------------------------------
              Standard                     Proposed  limit                                HW Fuel >= 10,000 Btu/
                                                                HW Fuel < 10,000 Btu/lb             lb
----------------------------------------------------------------------------------------------------------------
Mercury (lb/MM Btu).................  3.7E-6..................  19 [mu]g/dscm..........  4.2E-5
Particulate matter (gr/dscf)........  0.032...................                        0.035
Semivolatile metals (lb/MM Btu).....  1.1E-5..................  150 [mu]g/dscm.........  8.2E-5
Chromium (lb/MM Btu)................  1.1E-4..................  370 [mu]g/dscm.........  1.3E-4
Total chlorine (Lb/MM Btu)..........  2.5E-2..................  31 ppmv................  5.1E-2
Alternative to the particulate        1.1E-5..................  150 [mu]g/dscm.........  8.2E-5
 matter standard: Combined emissions
 of lead, cadmium and selenium (lb/
 MM Btu).
Alternative to the particulate        1.1E-4..................  370 [mu]g/dscm.........  1.3E-4
 matter standard: Combined emissions
 of arsenic, beryllium, chromium,
 antimony, cobalt, manganese, and
 nickel (lb/MM Btu).
----------------------------------------------------------------------------------------------------------------

    The changes in the liquid fuel boiler standards for new sources 
since proposal are:

[[Page 59423]]



----------------------------------------------------------------------------------------------------------------
                                                                                  Final limit
              Standard                     Proposed limit     --------------------------------------------------
                                                                HW fuel < 10,000 Btu/lb  HW fuel > 10,000 Btu/lb
----------------------------------------------------------------------------------------------------------------
Dioxin and Furan, dry APCD (ng TEQ/   0.015 or temp control                           0.40
 dscm).                                <400F for dry APCD.
Mercury (lb/MM Btu).................  3.8E-7.................  6.8 [mu]g/dscm..........  1.2E-6
Particulate matter (gr/dscf)........  0.0076.................                        0.0087
Semivolatile metals (lb/MM Btu).....  4.3E-6.................  78 [mu]g/dscm...........  6.2E-6
Chromium (lb/MM Btu)................  3.6E-5.................  12 [mu]g/dscm...........  1.4E-5
Total chlorine (lb/MM Btu)..........  7.2E-4.................  31 [mu]g/dscm...........  5.1E-2
Alternative to the particulate        4.3E-6.................  78 [mu]g/dscm \1\.......  6.2E-6 \1\
 matter standard: Combined emissions
 of lead, cadmium and selenium (lb/
 MM Btu).
Alternative to the particulate        3.6E-5.................  12 [mu]g/dscm \2\.......  1.4E-5 \2\
 matter standard: Combined emissions
 of arsenic, beryllium, chromium,
 antimony, cobalt, manganese, and
 nickel (lb/MM Btu).
----------------------------------------------------------------------------------------------------------------
\1\ New or reconstructed liquid fuel boilers that process residual oil or liquid feedstreams that are neither
  fossil fuel nor hazardous waste and that operate pursuant to the alternative to the particulate matter
  standard must comply with the alternative emission concentration standard of 4.7 [mu]g/dscm, which is
  applicable to lead, cadmium and selenium emissions attributable to all feedstreams (hazardous and
  nonhazardous).
\2\ New or reconstructed liquid fuel boilers that process residual oil or liquid feedstreams that are neither
  fossil fuel nor hazardous waste that operate pursuant to the alternative to the particulate matter standard
  must comply with the alternative emission concentration standard of 12 [mu]g/dscm, which is applicable to
  arsenic, beryllium, chrome, antimony, cobalt, manganese, and nickel emissions attributable to all feedstreams
  (hazardous and nonhazardous).

F. Hydrochloric Acid Production Furnaces

    The changes in the hydrochloric acid production furnace standards 
for existing sources since proposal are:

------------------------------------------------------------------------
          Standard               Proposed limit          Final limit
------------------------------------------------------------------------
Dioxin and Furans...........  0.4 ng TEQ/dscm.....  Carbon Monoxide/
                                                     Total Hydrocarbons
                                                     and DRE standards
                                                     as surrogates.
Total chlorine..............  14 ppmv or 99.9927%   150 ppmv or 99.923%
                               system removal        system removal
                               efficiency.           efficiency.
------------------------------------------------------------------------

    The changes in the hydrochloric acid production furnace standards 
for new sources since proposal are:

------------------------------------------------------------------------
          Standard               Proposed limit          Final limit
------------------------------------------------------------------------
Dioxin and Furans...........  0.4 ng TEQ/dscm.....  Carbon Monoxide/
                                                     Total Hydrocarbons
                                                     and DRE standards
                                                     as surrogates
Total chlorine..............  1.2 ppmv or 99.9994%  25 ppmv or 99.987%
                               system removal        system removal
                               efficiency.           efficiency
------------------------------------------------------------------------

G. Dioxin/Furan Testing for Sources Not Subject to a Numerical Standard

    Today's final rule requires that all sources not subject to a 
numerical dioxin and furan standard perform a one time test to 
determine their dioxin and furan emissions. See the discussion in Part 
Four, Section VII.L.
    In the proposed rule, this requirement was limited to solid fuel 
boilers and those liquid fuel boilers with a wet or no air pollution 
control system. The final rule expands this requirement to include 
hydrochloric acid production furnaces and those lightweight aggregate 
kilns that elect to comply with the temperature limit at the kiln exit 
in lieu of the 0.20 ng TEQ/dscm dioxin/furan standard. Those sources 
are not subject to a numerical dioxin/furan standard under the final 
rule for reasons explained in Volume III of the Technical Support 
Document, Sections 12 and 15. We note that sources not subject to a 
numerical dioxin/furan emission standard are subject to the carbon 
monoxide or hydrocarbon standards and the DRE standard as surrogates.
    We are making no changes to the implementation of this requirement. 
See the proposed rule at 69 FR at 21307 for more information.

III. Statistics and Variability

A. Using Statistical Imputation To Address Variability of Nondetect 
Values

    In the final rule, we use a statistical approach to impute the 
value of nondetect emissions and feedrate measurements to avoid 
dampening of the variability of data sets when nondetect measurements 
are assumed to be present at the detection limit.
    At proposal, we assumed that nondetects (i.e., HAP levels in stack 
emissions below the level of detection of the applicable analytic 
method) are invariably present at the detection limit. Commenters on 
the proposed rule stated, however, that assuming nondetects are present 
at the detection limit dampens emissions variability--a consideration 
necessary to reasonably ascertain sources' performance over time. This 
could have significant practical consequence for those data sets (such 
as the data base for liquid fuel boilers) dominated by nondetected 
values. We agree with these commenters, and instead of making the 
arbitrary assumption that all nondetected values are identical (which

[[Page 59424]]

in fact is highly unlikely), we are using a statistical methodology to 
impute the value of nondetect measurements.
    The imputation approach assigns a value for each nondetect 
measurement in a data set within the possible range of values that 
results in maximizing the 99th percentile upper prediction limit for 
the data set. For example, the possible range of values for a 
measurement that is 100% nondetect is between zero and the detection 
limit.
    On February 4, 2005 we distributed a direct request for comments on 
the imputation approach to major stakeholders. We respond to the 
comments we received in Part Four, Section IV.D of today's notice.

B. Degrees of Freedom When Imputing a Standard Deviation Using the 
Universal Variability Factor for Particulate Matter Controlled by a 
Fabric Filter

    The use of the universal variability factor to impute a standard 
deviation for particulate emissions from sources controlled with a 
fabric filter takes advantage of the empirical observation that the 
standard deviation of particulate emissions from sources is positively 
correlated to the average particulate emissions of sources. Based on 
this observation, we use regression analysis to determine the best 
fitting curve to explain the relationship of average value to standard 
deviation.
    In the final rule, we use the actual sample size, rather than an 
assumed sample size of nine used at proposal, to determine the degrees 
of freedom for the t-statistic to calculate the floor using the 
standard deviation imputed from the universal variability factor for 
particulate matter controlled by a fabric filter.
    At proposal, we used eight degrees of freedom to identify the t-
statistic to account for within-test condition variability (i.e., run-
to-run variability) for standard deviations imputed from the universal 
variability factor regression.\28\ This is because, on average, about 
three test conditions with nine individual test runs are associated 
with each source used to develop the regression curve.
---------------------------------------------------------------------------

    \28\ USEPA, ``Draft Technical Support Document for HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' March 2004, p. 
5-4.
---------------------------------------------------------------------------

    A commenter states, however, that this approach can dramatically 
understate variability when imputing a standard deviation for a source 
with only three runs because the t-statistic is substantially higher 
for 2 degrees of freedom than 8 degrees of freedom.
    We agree with the commenter. Moreover, using the actual number of 
runs to identify the t-statistic rather than assuming nine runs is 
appropriate given that the true test condition average is less certain 
for sources with only three runs, and thus there is less certainty in 
the imputed standard deviation. The higher t-statistic associated with 
a three-run data set reflects this uncertainty.
    In addition, we include emissions data classified as ``normal'' in 
the regression analysis for the final rule. At proposal, we used only 
data classified as CT (i.e., highest compliance test condition in a 
test campaign) or IB (i.e., a compliance test condition that achieved 
lower emissions than another compliance test condition in the test 
campaign). We conclude that normal data (i.e., emissions data that were 
not used to establish operating limits and thus do not reflect 
variability in controllable operating parameters) should also be 
considered in the regression analysis because particulate matter 
emissions are relatively insensitive to baghouse inlet loading and 
operating conditions.\29\ Including normal emissions in the analysis 
provides additional data to better quantify these devices' performance 
variability.
---------------------------------------------------------------------------

    \29\ USEPA, ``Technical Support Document for HWC MACT Standards, 
Volume III: Selection of MACT Standards,'' September 2005, Section 
5.3. See also Part Four, Section III.C of this preamble.
---------------------------------------------------------------------------

IV. Compliance Assurance for Fabric Filters, Electrostatic 
Precipitators, and Ionizing Wet Scrubbers

    The final rule provides additional requirements to clarify how you 
determine the duration of periods of operation when the alarm set point 
has been exceeded for a bag leak detection system or a particulate 
matter detection system:
    1. You must keep records of the date, time, and duration of each 
alarm, the time corrective action was initiated and completed, and a 
brief description of the cause of the alarm and the corrective action 
taken.
    2. You must record the percent of the operating time during each 6-
month period that the alarm sounds.
    3. In calculating the operating time percentage, if inspection of 
the fabric filter, electrostatic precipitator, or ionizing wet scrubber 
demonstrates that no corrective action is required, no alarm time is 
counted.
    4. If corrective action is required, each alarm shall be counted as 
a minimum of 1 hour.
    The final rule also establishes revised procedures for establishing 
the alarm set point if you elect to use a particulate matter detector 
system in lieu of site-specific operating parameter limits for 
compliance assurance for sources equipped with electrostatic 
precipitators and ionizing wet scrubbers. The rule explicitly allows 
you to maximize controllable operating parameters during the 
comprehensive performance test to account for variability by, for 
example, detuning the APCD or spiking ash. To establish the alarm set-
point, you may either establish the set-point as the average of the 
test condition run average detector responses during the comprehensive 
performance test or extrapolate the detector response after 
approximating the correlation between the detector response and 
particulate matter emission concentrations. You may extrapolate the 
detector response up to a response value that corresponds to 50% of the 
particulate matter emission standard or 125% of the highest particulate 
matter concentration used to develop the correlation, whichever is 
greater. To establish an approximate correlation of the detector 
response to particulate matter emission concentrations you should use 
as guidance Performance Specification-11 for PM CEMS (40 CFR Part 60, 
Appendix B), except that you need conduct only 5 runs to establish the 
initial correlation rather than a minimum of 15 runs required by PS-11.
    The final rule also notes that an exceedance of a detector response 
that corresponds to the particulate matter emission standard is not 
evidence that the standard has been exceeded because the correlation is 
an approximate correlation used for the purpose of compliance assurance 
to determine when corrective measures must be taken. The correlation, 
however, does not meet the requirements of PS-11 for compliance 
monitoring.
    In addition, if you elect to use a particulate matter detection 
system in lieu of site-specific control device operating parameter 
limits on the electronic control device, the ash feedrate limit for 
incinerators and boilers under Sec.  63.1209(m)(3) is waived. The ash 
feedrate limit is waived because the particulate matter detection 
system continuously monitors relative particulate matter emissions and 
the alarm set point provides reasonable assurance that emissions will 
not exceed the standard.\30\
---------------------------------------------------------------------------

    \30\ Note that if your incinerator or boiler is equipped with a 
fabric filter and you elect under Sec.  63.1206(c)(8)(i) to use a 
particulate matter detection system in lieu of a bag leak detection 
system for compliance assurance, the ash feedrate limit is waived. 
The ash feedrate limit is not waived if you use a bag leak detection 
system, however, because the alarm level may not ensure compliance 
with the emission standard when you follow the concepts in the 
Agency's guidance document on bag leak detection systems to 
establish the alarm level.

---------------------------------------------------------------------------

[[Page 59425]]

    Finally, you must submit an excessive exceedance notification 
within 30 days of the date that the alarm set-point is exceeded more 
than 5 percent of the time during any 6-month block period of time, or 
within 30 days after the end of the 6-month block period, whichever is 
earlier. The proposed rule would have required you to submit that 
notification within 5 days of the end of the 6-month block period.

V. Health-Based Compliance Alternative for Total Chlorine

    The final rule includes the following major changes to the proposed 
health-based compliance alternative for total chlorine:
    (1) You must use 1-hour Reference Exposure Levels (aRELs) rather 
than 1-hour acute exposure guideline levels (AEGL-1) as the acute 
health risk threshold metric when calculating 1-hour HCl-equivalent 
emission rates;
    (2) You must establish a long-term average chlorine feedrate limit 
(i.e., 12 hour rolling average or an (up to) annual rolling average) as 
the annual average HCl-equivalent emission rate limit divided by [1 - 
system removal efficiency]. You establish the total chlorine system 
removal efficiency during the comprehensive performance test. The 
proposed rule would have required you to establish the long-term 
average chlorine feedrate limit as the average of the test run averages 
of the comprehensive performance test.\31\
---------------------------------------------------------------------------

    \31\ Note that, as a practical matter, most sources must 
establish the chlorine feedrate limit as the average of the test run 
average feedrate limit during the comprehensive performance test to 
demonstrate compliance with the semivolatile emission standard. This 
is because chlorine feedrate is a compliance assurance parameter for 
the semivolatile metal emission standard. That feedrate limit is 
based on a 12-hour rolling average. To ensure compliance with the 
annual average HCl-equivalent emission rate limit, however, that 
feedrate limit cannot exceed the value calculated as the annual 
average HCl-equivalent emission rate limit divided by [1 - system 
removal efficiency], where you demonstrate the total chlorine system 
removal efficiency during the performance test.
---------------------------------------------------------------------------

    (3) At proposal, we requested comment on whether and how to 
establish a short-term chlorine feedrate limit to ensure that the acute 
exposure Hazard Index of 1.0 is not exceeded. See 69 FR at 21304. We 
conclude for the final rule that a 1-hour rolling average feedrate 
limit may be needed for some situations (i.e., if chlorine feedrates 
can vary substantially during the averaging period for the long-term 
feedrate limit and potentially result in an exceedance of the 1-hour 
average HCl-equivalent emission rate limit). Accordingly, although your 
eligibility for the health-based compliance alternatives is based on 
annual average HCl-equivalent emissions, you must determine considering 
prescribed criteria whether your 1-hour HCl-equivalent emission rate 
may exceed the national exposure standard (i.e., Hazard Index not 
exceeding 1.0 considering the maximum 1-hour average ambient 
concentration of hydrogen chloride and chlorine at an off-site receptor 
location\32\) and thus may exceed the 1-hour average HCl-equivalent 
emission rate limit absent an hourly rolling average limit on the 
feedrate of chlorine. If the acute exposure standard may be exceeded, 
you must establish an hourly rolling average chlorine feedrate limit as 
the 1-hour HCl-equivalent emission rate limit divided by [1 - system 
removal efficiency]. You establish the system removal efficiency during 
the comprehensive performance test.
---------------------------------------------------------------------------

    \32\ Under the site-specific risk assessment approach to 
demonstrate eligibility, you must consider locations where people 
reside and where people congregate for work, school, or recreation.
---------------------------------------------------------------------------

    (4) When calculating HCl-equivalent emission rates, rather than 
partitioning total chlorine emissions between chlorine and HCl (i.e., 
the Cl<INF>2</INF>/HCl volumetric ratio) based on the comprehensive 
performance test as proposed, you must establish the Cl<INF>2</INF>/HCl 
volumetric ratio used to calculate the annual average HCl-equivalent 
emission rate based on the historical average ratio from all regulatory 
compliance tests. You must establish the Cl<INF>2</INF>/HCl volumetric 
used to calculate the 1-hour average HCl-equivalent emission rate as 
the highest of the historical ratios from all regulatory compliance 
tests. The rule allows you to exclude ratios from historical compliance 
tests where the emission data may not be representative of the current 
Cl<INF>2</INF>/HCl ratio for reasons such as changes to the design or 
operation of the combustor or biases in measurement methods. The rule 
also explicitly allows the permitting authority to require periodic 
emissions testing to obtain a representative average and maximum ratio;
    (5) The look-up table analysis has been refined by presenting 
annual average and 1-hour HCl-equivalent emission rate limits as a 
function of stack height, stack diameter, and distance to property 
line. In addition, separate look-up tables are presented for flat 
terrain and simple elevated terrain;
    (6) The proposed rule required approval of the eligibility 
demonstration before you could comply with the alternative health-based 
emission limits for total chlorine. Under the final rule, if your 
permitting authority has not approved your eligibility demonstration by 
the compliance date, and has not issued a notice of intent to 
disapprove your demonstration, you may nonetheless begin complying, on 
the compliance date, with the annual average HCl-equivalent emission 
rate limits you present in your eligibility demonstration. In addition, 
if your permitting authority issues a notice of intent to disapprove 
your eligibility demonstration, the authority will identify the basis 
for that notice and specify how much time you will have to submit 
additional information or to comply with the MACT total chlorine 
standards. The permitting authority may extend the compliance date of 
the total chlorine standards to allow you to make changes to the design 
or operation of the combustor or related systems as quickly as 
practicable to enable you to achieve compliance with the MACT total 
chlorine standards;
    (7) We have revised the approach for determining chlorine emissions 
if you feed bromine or sulfur during the comprehensive performance test 
at levels higher than those specified in Sec.  63.1215(e)(3)(ii)(B). 
Under the final rule, you must use EPA Method 320/321 or ASTM D 
6735'01, or an equivalent method, to measure hydrogen chloride, and 
Method 26/26A, or an equivalent method, to measure chlorine and 
hydrogen chloride. You must determine your chlorine emissions to be the 
higher of: (1) The value measured by Method 26/26A, or an equivalent 
method; or (2) the value calculated by difference between the combined 
hydrogen chloride and chlorine levels measured by Method 26/26a, or an 
equivalent method, and the hydrogen chloride measurement from EPA 
Method 320/321 or ASTM D 6735-01, or an equivalent method; and
    (8) The proposed rule would have required you to conduct a new 
comprehensive performance test if you planned to make changes to the 
facility that would lower the annual average HCl-equivalent emission 
rate limit. Under the final rule, you would be required to conduct a 
performance test as a result of a planned change only for a change to 
the design, operation, or maintenance of the combustor that could 
affect the system removal efficiency for total chlorine if the change 
could reduce the system removal efficiency, or if the change would 
increase the system removal efficiency and you elect to increase the 
feedrate limits on total chlorine and chloride.

[[Page 59426]]

Part Four: What Are the Responses to Major Comments?

I. Database

A. Revisions to the EPA's Hazardous Waste Combustor Data Base

    Comment: Several commenters identify sources which have ceased 
operations as a hazardous waste combustor and should be removed from 
EPA's data base.
    Response: We agree with commenters that data and information from 
sources no longer burning hazardous waste should not be included in our 
hazardous waste combustor data base and should not be used to calculate 
the MACT standards. We consider any source that has initiated RCRA 
closure procedures and activities as a source that is no longer burning 
hazardous waste. This data handling decision is consistent with the 
approach we used in the 1999 final rule. See 64 FR at 52844. As we 
stated in that rule, ample emissions data remain to support calculating 
the MACT standards without using data from sources that no longer burn 
hazardous waste.
    As a result, we removed the following former hazardous waste 
combustors from the data base: the Safety-Kleen incinerator in 
Clarence, New York, the Dow Chemical Company incinerators in Midland, 
Michigan, and LaPorte, Texas, the two Holcim wet process cement kilns 
in Holly Hill, South Carolina, the Dow Chemical Company liquid fuel-
fired boiler in Freeport, Texas, the Union Carbide liquid fuel-fired 
boilers in Hahnville, Louisiana, and Texas City, Texas, and six Dow 
Chemical Company hydrochloric production furnaces in Freeport, Texas.
    We are retaining, however, Solite Corporation's lightweight 
aggregate facility in Cascade, Virginia, in the data base. Even though 
the facility recently initiated RCRA closure procedures, this data 
handling decision differs from those listed in the preceding paragraph 
because Solite Corporation provided this new information in February 
2005 while information on the other closures was reported or available 
to us in 2004. Because we cannot continually adjust our data base and 
still finalize this rulemaking by the court-ordered deadline, we 
stopped making revisions to the data base in late 2004. Additional 
facility changes after that date, like Solite Corporation's Cascade 
facility closure, simply could not be incorporated.
    Comment: One commenter identifies a source in EPA's data base that 
should be classified as a boiler instead of a hydrochloric acid 
production furnace.
    Response: We agree with the commenter. In today's rule, Dow 
Chemical Company's boiler F-2820, located in Freeport, Texas, is 
reclassified in our data base as a boiler. This source is identified as 
unit number 2020 in our data base.

B. Use of Data From Recently Upgraded Sources

    Comment: Many commenters recommend that EPA remove from the data 
base (or not consider for standards-setting purposes) emissions data 
from sources that upgraded their emissions controls to comply with the 
promulgated emission standards of either the 1999 rule or the 2002 
interim standards. Several commenters also state that any emissions 
data that were obtained or used to demonstrate compliance with the 
promulgated standards of 1999 or 2002 should not be used for standard-
setting purposes by the Agency. That is, EPA must evaluate the source 
category as it existed at the beginning of the rule development process 
and not after emissions controls are later added to comply with the 
1999 or 2002 standards. Several commenters also state that EPA is only 
partly correct in claiming that the interim standards are not MACT 
standards because the interim standards were established and considered 
to be MACT until the Court issued its opinion in July 2001. Until that 
time, sources proceeded to upgrade their facilities to achieve the 
standards promulgated in 1999. The rationale for these recommendations 
is threefold: (1) Use of the data unfairly ignores the MACT-driven 
reductions already achieved by some sources; (2) it is contrary to 
sound public policy to use data from upgraded facilities to ``ratchet 
down'' the MACT floors to a level more stringent because these sources 
would not have increased their level of performance but for the legal 
obligation to comply with the standards; and (3) EPA's reliance on 
National Lime Ass'n v. EPA, 233 F.3d 625, 640 (D.C. Cir. 2000), for the 
proposition that the motivation for a source's performance is legally 
irrelevant in developing MACT floor levels is misplaced because that 
case involved the initial MACT standard setting process, and not a 
subsequent rule.
    One commenter agrees with EPA's proposed position and states that 
use of data from sources that have upgraded is not only appropriate, 
but also required by the Clean Air Act. This commenter states that the 
actual performance of sources that have upgraded their emissions 
equipment--to meet the 1999 standards or for any reason--is reflected 
only by the most recently generated emissions data for the source. 
Thus, the Clean Air Act requires EPA to use the most recently generated 
data available to it and precludes the Agency from using older, out-of-
date performance data.
    EPA also received several comments stating that the language of 
section 112(d)(3)(A) of the Clean Air Act informs how the Agency should 
consider emissions data from sources that conducted testing after that 
1999 rule was promulgated. One commenter states that the only data 
which should not be used in calculating the MACT floors are from 
sources that are subject to lowest achievable emission rates (LAER). 
Thus, the commenter states, Congress considered the possibility of 
significant and recent upgrades, and concluded that EPA should use up-
to-date data to reflect source's performance, but must exclude certain 
sources from the floor calculation if their upgrades were of a specific 
degree and were accomplished within a specific period of time. Another 
commenter states that Congress did not intend to pile technology upon 
technology as confirmed by section 112(d)(3)(A) that specifically 
excludes sources that implemented LAER from consideration when 
establishing section 112(d) standards. Thus, the commenter states, 
considering data from sources that have upgraded violates both the 
language and intent of the Clean Air Act. Another commenter states 
that, while Congress no doubt contemplated that EPA should use all 
available emissions information in setting initial MACT standards, 
neither the statute nor the legislative history suggest that follow-up 
MACT rulemakings require the use of data reflecting compliance efforts 
with previous MACT standards or interim standards.
    Response: As proposed, EPA maintains its position on use of post-
1999 emissions data. The statute indicates that EPA is to base MACT 
floors on performance of sources ``for which the Administrator has 
emissions information.'' Section 112(d)(3)(A); CKRC, 255 F. 3d at 867. 
There can be no dispute that post-1999 performance data in EPA's 
possession fits this description. We also reiterate that the motivation 
for the control reflected in data available to us is irrelevant. See 69 
FR at 21217-218. We further agree with those commenters who pointed out 
that Congress was explicit when it wanted certain emissions information 
(i.e., sources operating pursuant to a LAER standard) excluded from 
consideration in establishing floors. There is, of course, no such 
enumerated exception

[[Page 59427]]

for sources that have upgraded their performance for other reasons.
    We also do not agree with those commenters arguing (with respect to 
the standards for the Phase 1 sources (incinerators, cement kilns, and 
lightweight aggregate kilns)) in effect that the present rulemaking 
involves revision of an existing MACT standard. If this were indeed a 
revision of a MACT standard under section 112(d)(6), then EPA would not 
redetermine floor levels. See 70 FR at 20008 (April 15, 2005). However, 
EPA has not to date promulgated valid MACT floors or valid MACT 
standards for these sources. The 1999 standards do not reflect MACT, as 
held by the CKRC court. The interim standards likewise do not reflect 
MACT, but were designed to prevent a regulatory gap and were described 
as such from their inception. 67 FR at 7693 (Feb. 13, 2002); see also 
Joint Motion of all Parties for Stay of Issuance of Mandate in case no. 
99-1457 (October 19, 2001), pp. 11-12 (``The Parties emphasize that the 
contemplated interim rule is in the nature of a remedy. It would not 
respond to the Court's mandate regarding the need to demonstrate that 
EPA's methodology reasonably predicts the performance of the average of 
the best performing twelve percent of sources (or best-performing 
source). EPA intends to address those issues in a subsequent rule, 
which will necessarily require a longer time to develop, propose, and 
finalize.'') EPA consequently believes that it is adopting in this rule 
the initial section 112(d) MACT standards for hazardous waste burning 
incinerators, cement kilns, and lightweight aggregate kilns, and that 
the floor levels for existing sources are based, as provided in section 
112(d)(3), on performance of those sources for which EPA has 
``emissions information.''
    However, we disagree with the comment that we must make exclusive 
use of the most recent information from hazardous waste combustion 
sources. There is no such restriction in section 112(d)(3). EPA has 
exhaustively examined all of the data in its possession for all source 
categories covered by this rule, and determined (and documented) which 
data are suitable for evaluating sources' performance.

C. Correction of Total Chlorine Data to Address Potential Bias in Stack 
Measurement Method

    Comment: Several commenters state that EPA's proposed total 
chlorine standards of 1.5 ppm for existing incinerators and 0.18 ppm 
for new incinerators are based on biased data of indeterminate quality 
and are unachievable. Commenters assert that Method 26A and its RCRA 
equivalent, SW 846 Method 0050, have a negative bias at concentrations 
below 20 ppmv when used on stacks controlled with wet scrubbers. 
Commenters cite two recurring situations when this bias is likely to 
occur: (1) hydrogen chloride dissolving in condensed moisture in the 
sampling train; and (2) hydrogen chloride reacting with alkaline 
compounds from the scrubber water that are collected on the filter 
ahead of the impingers.
    Commenters are particularly concerned about the negative bias 
associated with stack gas containing substantial water vapor. 
Commenters note that EPA found in a controlled laboratory study by 
Steger \33\ that the bias is between 17 and 29 percent at stack gas 
moisture content of 7 to 9 percent. This stack gas moisture is much 
less than the nominal 50% moisture contained in some hazardous waste 
combustor stacks according to the commenters. Commenters believe this 
is why EPA's Method 0050, which was used to gather most of the data in 
the HWC MACT data base, states in Section 1.2 that ``this method is not 
acceptable for demonstrating compliance with HCl emission standards 
less than 20 ppm.''
---------------------------------------------------------------------------

    \33\ Steger, J.L., et al, ``Laboratory Evaluation of Method 0050 
for Hydrogen Chloride'', Proc of 13th Annual Incineration 
Conference, Houston, TX, May 1994.
---------------------------------------------------------------------------

    Moreover, commenters state that the procedures in Method 0050 to 
address the negative bias caused by condensed moisture were not 
followed for many RCRA compliance tests. The method uses an optional 
cyclone to collect moisture droplets, and requires a 45 minute purge of 
the cyclone and sampling train to recover hydrogen chloride from water 
collected by the cyclone and any condensed moisture in the train. The 
cyclone is not necessary if the stack gas does not contain water 
droplets. According to commenters, the cyclone and subsequent purge 
were often not used in the presence of water droplets because a 
potential low bias below 20 ppmv was irrelevant when demonstrating 
compliance with emission standards on the order of 100 ppmv. There was 
no need for the extra complexity and expense of using a cyclone and 
train purge given the purpose of the test. Although the data were 
acceptable for their intended purpose, commenters conclude that the 
data are not useful for establishing standards below 20 ppmv.
    For these reasons, commenters suggest that EPA not consider total 
chlorine measurements below 20 ppmv when establishing the standards.
    Response: For the reasons discussed below, we corrected all total 
chlorine measurements in our data base for all source categories that 
were below 20 ppmv to 20 ppmv to establish the total chlorine floors. 
Moreover, to address run-to-run variability given that all runs for 
several data sets are now corrected to 20 ppmv, we impute a run 
standard deviation based on a regression analysis of run standard 
deviation versus total chlorine concentration for sources with total 
chlorine measurements greater than 20 ppmv. This is the same approach 
we used to impute variability from sources using fabric filters when 
determining the particulate matter MACT floors.
    Effect of Moisture Vapor. Commenters imply that stack gas with high 
levels of gas phase water vapor will inherently be problematic, 
particularly at emissions less than 20 ppmv. There is no basis for 
claiming that water vapor, per se, causes a bias in SW-846 Method 0050 
or its equivalent, Method 26A. Condensed moisture (i.e., water 
droplets), however, can cause a bias because it can dissolve hydrogen 
chloride in the sampling train and prevent it from being captured in 
the impingers if the sampling train is not properly purged. Water 
droplets can potentially be present due to entrainment from the wet 
scrubber, condensation in cooler regions of the stack along the stack 
walls, and entrainment from condensed moisture dripping down the stack 
wall across the inlet duct opening.
    Although Method 0050 addresses the water droplet issue by use of a 
cyclone and 45 minute purge, the Steger paper (Ibid.) concludes that a 
45 minute purge is not adequate to evaporate all water collected by the 
cyclone in stacks with a total moisture content (vapor and condensed 
moisture) of 7 to 9%. At those moisture levels, Steger documented the 
negative bias that commenters reference. Steger's recommendation was to 
increase the heat input to the sample train by increasing the train and 
filter temperature from 120C (248F) to 200C (392F). We agree that 
increasing the probe and filter temperature will provide a better 
opportunity to evaporate any condensed moisture, but another solution 
to the problem is to require that the post-test purge be run long 
enough to evaporate all condensed moisture. That is the approach used 
by Method 26A, which EPA promulgated after Method 0050, and which 
sources must use to demonstrate compliance with the final standards. 
Method 26A uses an extended purge time rather than

[[Page 59428]]

elevating the train temperature to address condensed moisture because 
that approach can be implemented by the stack tester at the site 
without using nonstandard equipment.
    We attempted to quantify the level of condensed moisture in the 
Steger study and to compare it to the levels of condensed moisture that 
may be present in hazardous waste combustor stack gas. This would 
provide an indication if the bias that Steger quantified with a 45 
minute purge might also be applicable to some hazardous waste 
combustors. We conclude that this comparison would be problematic, 
however, because: (1) given the limited information available in the 
Steger paper, it is difficult to quantify the level of condensed 
moisture in his gas samples; and (2) we cannot estimate the levels of 
condensed moisture in hazardous waste combustor stack gas because, even 
though condensed moisture may have been present during a test, method 
protocol is to report the saturation moisture level only (i.e., the 
amount of water vapor present), and not the total moisture content 
(i.e., both condensed and vapor phase moisture).
    We can conclude, however, that, if hazardous waste combustor stack 
gas were to contain the levels of condensed moisture present in the gas 
that Steger tested, the 45 minute purge required by Method 0050 would 
not be sufficient to avoid a negative bias. We also conclude that this 
is potentially a practical issue and not merely a theoretical concern 
because, as commenters note, hazardous waste combustors that use wet 
scrubbers are often saturated with water vapor that will condense if 
the flue gas cools.
    Data from Wet Stacks When a Cyclone Was Not Used. Commenters state 
that Method 0050 procedures for addressing water droplets (adequate or 
not, as discussed above) were not followed in many cases because a low 
bias below 20 ppmv was not relevant to demonstrating compliance with 
standards on the order of 100 ppmv. We do not know which data sets may 
be problematic because, as previously stated, the moisture 
concentration reported was often the saturation (vapor phase only) 
moisture level and not the total (vapor and liquid) moisture in the 
flue gas. We also have no documentation that a cyclone was used--even 
in situations where the moisture content was documented to be above the 
dew point. We therefore conclude that all data below 20 ppmv from 
sources controlled with a wet scrubber are suspect and should be 
corrected.
    Potential Bias Due to Filter Affinity for Hydrogen Chloride. 
Studies by the American Society of Testing and Materials indicate that 
the filter used in the Method 0050 train (and the M26/26A trains) may 
adsorb/absorb hydrogen chloride and cause a negative bias at low 
emission levels. (See ASTM D6735-01, section 11.1.3 and ``note 2'' of 
section 14.2.3) This inherent affinity for hydrogen chloride can be 
satisfied by preconditioning the sampling train for one hour. None of 
the tests in our database were preconditioned in such a manner.
    We are normally not concerned about this type of bias because we 
would expect the bias to apply to all sources equally (e.g., wet or dry 
gas) and for all subsequent compliance tests. In other words, we are 
ordinarily less concerned if a standard is based on biased data, as 
long as the means by which the standard was developed and the means of 
compliance would experience identical bias.
    However, we did correct the wet gas measurements below 20 ppmv to 
address the potential low bias caused by condensed moisture. This 
correction would also correct for any potential bias caused by the 
filter's inherent affinity for hydrogen chloride. This results in a 
data set that is partially corrected for this issue--sources with wet 
stacks would be corrected for this potential bias while sources with 
dry stacks would not be corrected. To address this unacceptable mix of 
potentially biased and unbiased data (i.e., dry gas data biased due to 
affinity of filter for hydrogen chloride and wet gas data corrected for 
condensed moisture and affinity of filter for hydrogen chloride), we 
also correct total chlorine measurements from dry gas stacks (i.e., 
sources that do not use wet scrubbers).
    Deposition of Alkaline Particulate on the Filter. Commenters are 
also concerned that hydrogen chloride may react with alkaline compounds 
from the scrubber water droplets that are collected on the filter ahead 
of the impingers. Commenters suggest this potential cause for a low 
bias at total chlorine levels below 20 ppmv is another reason not to 
use measurements below 20 ppmv to establish the standards.
    Although alkaline particulate deposition on the method filter 
causing a negative bias is a much greater concern for sources that have 
stack gas containing high levels of alkaline particulate (e.g., cement 
kilns, sources equipped with dry scrubbers), we agree with commenters 
that this may be of concern for all sources equipped with wet 
scrubbers. Our approach to correct all data below 20 ppmv addresses 
this concern.
    Decision Unique to Hazardous Waste Combustors. We note that the 
rationale for our decision to correct total chlorine data below 20 ppmv 
to account for the biases discussed above is unique to the hazardous 
waste combustor MACT rule. Some sources apparently did not follow 
Method 0050 procedures to minimize the low bias caused by condensed 
moisture for understandable reasons. Even if sources had followed 
Method 0050 procedures to minimize the bias (i.e., cyclone and 45 
minute purge) there still may have been a substantial bias because of 
insufficient purge time, as Steger's work may indicate. We note that 
the total chlorine stack test method used by sources other than 
hazardous waste combustors--Method 26A--requires that the cyclone and 
sampling train be purged until all condensed moisture is evaporated. We 
believe it is necessary to correct our data below 20 ppmv data because 
of issues associated exclusively with Method 0050 and how it was used 
to demonstrate compliance with these sources.
    Determining Variability for Data at 20 ppmv. Correcting those total 
chlorine data below 20 ppmv to 20 ppmv brings about a situation 
identical to the one we confronted with nondetect data. See Part Four, 
Section V.B. below. The MACT pool of best performing source(s) for some 
data sets is now comprised of largely the same values. This has the 
effect of understating the variability associated with these data.
    To address this concern, we took an approach similar to the one we 
used to determine variability of PM emissions for sources equipped with 
a fabric filter. In that case, we performed a linear regression on the 
data, charting variability against emissions, and used the variability 
that resulted from the linear regression analysis as the variability 
for the sources average emissions. In this case, most or all of the 
incinerator and liquid fuel boiler sources in the MACT pool have 
average emissions at or near 20 ppmv. We therefore performed a linear 
regression on the total chlorine data charting average test condition 
results above 20 ppmv against the variability associated with that test 
condition. The variability associated with 20 ppmv was the variability 
we used for incinerator and liquid fuel boiler data sets affected by 
the 20 ppmv correction.
    We also considered using the statistical imputation approach we 
used for nondetect values. See discussion in Section IV.B below. The 
statistical imputation approach for correcting data below 20 ppmv 
without dampening variability would involve imputing a value between 
the reported value and 20

[[Page 59429]]

ppmv because the ``true'' value of the biased data would lie in this 
interval. This approach would be problematic, however, given that many 
of the reported values were much lower than 20 ppmv; our statistical 
imputation approach would tend to overestimate the run to run 
variability. Consequently, we conclude that a regression analysis 
approach is more appropriate. A regression analysis is particularly 
pertinent in this situation because: (1) We consider data above 20 ppmv 
used to develop the regression to be unbiased; and (2) all the 
corrected data averages for which we are imputing a standard deviation 
from the regression curve are at or near 20 ppmv. Thus, any potential 
concern about downward extrapolation from the regression would be 
minimized.
    We note that, although a regression analysis is appropriate to 
estimate run-to-run variability for the corrected total chlorine data, 
we could not use a linear regression analysis to address variability of 
nondetect values. To estimate a standard deviation from a regression 
analysis, we would need to know the test condition average emissions. 
This would not be feasible, however, because some or all of the run 
measurements for a test condition are nondetect. In addition, we are 
concerned that a regression analysis would not accurately estimate the 
standard deviation at low emission levels because we would have to 
extrapolate the regression downward to levels where we have few 
measured data (i.e., data other than nondetect). Moreover, the 
statistical imputation approach is more suitable for handling 
nondetects because the approach calculates the run-to-run variability 
by taking into account the percent nondetect for the emissions for each 
run.\34\ A regression approach would be difficult to apply particularly 
in the case of test conditions containing partial nondetects or a mix 
of detect and nondetect values. Given these concerns with using a 
regression analysis to estimate the standard deviation of test 
conditions with runs that have one or more nondetect (or partial 
nondetect) measurements, we conclude that the statistical imputation 
approach best assures that the calculated floor levels account for run-
to-run emissions variability.
---------------------------------------------------------------------------

    \34\ For multi-constituent HAP (e.g. SVM) the emissions for a 
run could be comprised of fully detected values for some HAP and 
detection limits for other HAP that were nondetect.
---------------------------------------------------------------------------

    Compliance with the Standards. The final standards are based on 
data that were corrected to address specific issues concerning these 
data. See the above discussion regarding stack gas moisture, filter 
affinity for hydrogen chloride, and alkaline compound reactions with 
hydrogen chloride in the sampling train.
    Sources must demonstrate compliance using a stack test method that 
also addresses these issues. Sources with wet stacks must use Method 
26A and follow those procedures regarding the use of a cyclone and the 
purging of the system whenever condensed moisture may be present in the 
sampling system.
    Finally, all sources--those with either wet or dry gas--should 
precondition the sampling train for one hour prior to beginning the 
test to satisfy the filter's affinity for hydrogen chloride. The 
permitting authority will ensure that sources precondition the sample 
train (under authority of Sec.  63.1209(g)(2)) when they review and 
approve the performance test plan.

D. Mercury Data for Cement Kilns

    Comment: Several commenters state that EPA's data base of mercury 
emissions data (and associated feed concentrations of mercury in the 
hazardous waste) are unrepresentative and unsuitable for use in 
determining MACT standards for cement kilns. These comments are 
supported by an extensive amount of data submitted by the cement 
manufacturing industry including three years of data documenting day-
to-day levels of mercury in hazardous waste fuels fired to all 14 
hazardous waste burning cement kilns.\35\ The commenters recommend that 
EPA use the commenter-submitted data as the basis for assessing cement 
kilns' performance for control of mercury because it is the most 
complete and representative data available to EPA.
---------------------------------------------------------------------------

    \35\ See docket item OAR-2004-0022-0049.
---------------------------------------------------------------------------

    Response: We agree that the commenter-submitted mercury data are 
more representative than those we used at proposal. First, these data 
represent a significantly larger and more comprehensive dataset 
compared to the one used to support the proposed mercury standard. The 
commenter-submitted data document the day-to-day levels of mercury in 
hazardous waste fired to all cement kilns for a three year period 
covering 1999 to 2001. In total, approximately 20,000 measurements of 
the concentration of mercury in hazardous waste are included in the 
dataset. When considered in whole, these data describe the performance 
(and variability thereof) of all cement kilns for the three year period 
because each measurement represents the mercury concentration in the 
burn tank used to fire the kiln over the course of a day's operation 
(or longer period).\36\ In comparison, the data used to support the 
proposed floor level consisted of a much smaller dataset of 
approximately 50 test conditions representing a snapshot of performance 
somewhere in the range of normal operations, with each test condition 
representing a relatively short period of time (e.g., several 
hours).\37\ As discussed at proposal, we were concerned regarding the 
representativeness of this smaller dataset. See 69 FR at 21251. In 
addition, the commenter-submitted dataset allows us to better evaluate 
the only mercury control technique used by existing hazardous waste 
burning cement kilns--controlling the feed concentration of mercury in 
the hazardous waste. The commenters have demonstrated convincingly that 
the mercury dataset used at proposal does not properly show the range 
of performance and variability in performance these cement kilns 
actually experience, while the significantly more robust dataset 
submitted by commenters does illustrate this variability. Thus, we 
conclude the larger commenter-submitted dataset is superior to EPA's 
smaller testing dataset.
---------------------------------------------------------------------------

    \36\ Mercury is a volatile compound at the typical operating 
temperatures of the air pollution control devices used by cement 
kilns (i.e., baghouses and electrostatic precipitators). Most of the 
mercury exits the cement kiln system as volatile stack emissions, 
with a smaller fraction partitioning to the clinker product or 
cement kiln dust. Thus, in general, there is a proportional 
relationship between the mercury concentration in the hazardous 
waste and stack emissions of mercury (i.e., as the mercury 
concentration in hazardous waste increases (assuming mercury 
concentrations in other inputs such as raw materials and fossil 
fuels (coal) and other factors remain constant), emissions of 
mercury will correspondingly increase).
    \37\ EPA's dataset for mercury for cement kilns is not like the 
RCRA compliance test emission data for other HAPs where each source 
designs the compliance test such that the operating limits it 
establishes account for the variability it expects to encounter 
during its normal operations (e.g., semi- and low volatile metals). 
This is not necessarily true for mercury for cement kilns as shown 
in our analysis of our mercury dataset at proposal. See 69 FR at 
21251.
---------------------------------------------------------------------------

    We note that our MACT floor analysis of the commenter-submitted 
dataset to determine which sources are the best performers and to 
identify a mercury standard for cement kilns is discussed in the 
background document.\38\ Additional discussion of issues related to the 
mercury standard for cement kilns is found in Part Four, Section VI.B 
of the preamble.
---------------------------------------------------------------------------

    \38\ USEPA, ``Technical Support Document for HWC MACT Standards, 
Volume III: Selection of MACT Standards,'' Sections 7.5.3 and 11.0, 
September 2005.

---------------------------------------------------------------------------

[[Page 59430]]

E. Mercury Data for Lightweight Aggregate Kilns

    Comment: One commenter, an owner and operator of seven of the nine 
operating lightweight aggregate kilns, states that the mercury dataset 
used by EPA at proposal is a limited and unrepresentative snapshot of 
performance of their seven kilns. To support their position that the 
snapshot emissions data are unrepresentative, the commenter submitted 
eight months of data documenting levels of mercury in hazardous waste 
fuels fired to their lightweight aggregate kilns.\39\
---------------------------------------------------------------------------

    \39\ See docket items OAR-2004-0022-0270 and OAR-2004-0022-0333.
---------------------------------------------------------------------------

    Response: We agree with the commenter that their mercury data 
submission is more representative than those used at proposal. As 
discussed in a notice for public comment sent directly to certain 
commenters,\40\ the commenter-submitted dataset documents the day-to-
day levels of mercury in hazardous waste fuels fired to Solite 
Corporation's Arvonia kilns between October 2003 and June 2004. The 
dataset consists of over 310 measurements of the concentration in 
mercury in hazardous waste. Each measurement represents the mercury 
concentration of the burn tank used to fire the kiln over the course of 
a day's operation (or longer period). In comparison, the data used to 
support the proposed floor level consisted of a smaller dataset of 15 
test conditions.
---------------------------------------------------------------------------

    \40\ See docket item OAR-2004-0022-0370.
---------------------------------------------------------------------------

    The nature of the mercury data submitted by the commenter is the 
same as we received for the cement kiln category discussed in the 
preceding section. For similar reasons, we accept the more 
comprehensive commenter-submitted dataset as one that better shows the 
range of performance and variability in performance for these 
lightweight aggregate kilns. One notable difference, however, is that 
the commenter submitted mercury data only for its company (representing 
seven of nine lightweight aggregate kilns). Thus, we received no data 
documenting day-to-day levels of the concentration of mercury in 
hazardous waste fuels for the other two lightweight aggregate kilns 
owned by a different company. For these two lightweight aggregate 
kilns, we continue to use available data available in our database.\41\
---------------------------------------------------------------------------

    \41\ Unlike that is available for the commenter's kilns, we note 
that we have compliance test emissions data, which is designed to 
maximize operating parameters (e.g., HAP feedrates) that affect 
emissions, for the other two kilns. For additional discussion on how 
these data were analyzed in conjunction with the commenter-submitted 
data, see the document ``Technical Support Document for HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' Section 7.5.3 
and 12.0, September 2005.
---------------------------------------------------------------------------

    Comment: One commenter opposes the use of the commenter-submitted 
mercury data because EPA would be uncritically accepting a limited and 
select data set from a commenter with a direct interest in the outcome 
of its use. Instead, the commenter suggests EPA use its section 114 
authority to obtain all data that are available, not just the data 
selected by that commenter.
    Response: We disagree that we uncritically accepted the commenter-
submitted mercury data. The reason the commenter submitted data 
collected between October 2003 and June 2004 is that the facility was, 
prior to October 2003, in the process of upgrading its on-site analysis 
equipment. One outcome of this laboratory upgrade was its capability to 
detect mercury in hazardous waste at lower concentrations. Prior to the 
upgrade, the facility's on-site laboratory was capable of detecting 
mercury in the hazardous waste at a concentration of approximately 2 
ppmw, which is a level such that the vast majority of measurements 
would neither be detected nor useful for identifying best performers 
and their level of performance.\42\ The June 4, 2004 cutoff date 
represents a practicable date that measurements could still be 
incorporated into the commenter's public comments to the proposed rule, 
which were submitted on July 6, 2004. Finally, the commenter provided 
all waste fuel measurements during this period and states reliably that 
no measurements made during this period were selectively excluded.\43\
---------------------------------------------------------------------------

    \42\ A mercury concentration of 2 ppmw in the hazardous waste 
corresponds to a stack concentration of approximately 200 [mu]g/
dscm, which is well above the interim standard of 120 [mu]g/dscm for 
mercury.
    \43\ See also docket items OAR-2004-0022-0233 and OAR-2004-0022-
0367.
---------------------------------------------------------------------------

    We also reject the commenter's suggestion that we use our authority 
under section 114 of the Clean Air Act to obtain additional hazardous 
waste mercury concentration data from the facility. There is no 
obligation for us to gather more performance data, given that the 
statute indicates that we are to base floor levels on performance of 
sources ``for which the Administrator has emissions information.'' 
Section 112(d)(3)(A); CKRC, 255 F. 3d at 867. In addition, given our 
concerns about the usefulness of measurements with high detection 
limits discussed above, the collection of additional data prior to the 
laboratory upgrade would not be productive. When balanced against the 
expenditure of significant resources, both in time and level of effort, 
to collect several more months of data, we conclude that obtaining 
additional mercury measurements is unnecessary because the available 
eight months of data--including over 310 individual measurements--
represent a significant amount of data that we judge to be adequately 
reflective of the source's performance and variability in performance.

F. Incinerator Database

    Comment: Commenters state that many of the top performers (e.g., 
3011, 3015, 3022, 349) dilute emission concentrations in the stack by 
burning natural gas to initiate reactive waste (e.g., explosives, 
inorganic hydrides) or to decontaminate inert material. Commenters do 
not believe these units should be considered ``representative'' of the 
overall incinerator source category and should not be used to establish 
standards for incinerators combusting primarily organic wastes.
    Response: Source 3022 has closed and has been removed from the 
database. Emission data from source <greek-i>3015 (ICI explosives) has 
been excluded for purposes of calculating the particulate matter floor 
because the test report indicates this source was primarily feeding 
scrap metal, which we conclude to be an atypical waste stream from a 
particulate matter compliance perspective.\44\
---------------------------------------------------------------------------

    \44\ We did not have ash feed data for source 3015. We 
acknowledge that ash feed control levels do not significantly affect 
particulate matter emissions from sources equipped with baghouses. 
However, in this instance, the particulate matter emissions from 
this source may not be representative because this source may not 
have been feeding any appreciable levels of ash given that scrap 
metal feeds generally would not contribute to the ash loading into 
the baghouse.
---------------------------------------------------------------------------

    The sources identified by the commenter are among the best 
performing sources in two instances. Source 3011 is the second ranked 
best performer for the particulate matter standard. This source is 
among the best performers for particulate matter because it uses a 
state-of-the art baghouse that is equipped with Teflon coated bags. 
There is no evidence to suggest that this source was diluting its 
particulate matter emissions. We acknowledge that we do not have ash 
feed data for the test conditions that were used in the particulate 
matter standard analysis. However, this source had the third and fourth 
highest metal feed control levels among all the sources used in the 
MACT analysis for the semivolatile and low volatile metal

[[Page 59431]]

standards.\45\ We therefore conclude that it is appropriate to include 
this source in the MACT analysis that determines the relevant best 
performers for particulate matter.
---------------------------------------------------------------------------

    \45\ We note that feed control levels are normalized based on 
each source's gas flowrate. The feed control levels used to assess 
performance are therefore appropriate indicators that directly 
address whether emissions of these pollutants are in fact being 
diluted by the combustion of natural gas.
---------------------------------------------------------------------------

    Source 349 is the eighth ranked (out of 11) best performer for the 
particulate matter standard. We acknowledge that the ash feed level for 
this source is lower than most incinerators equipped with baghouses. 
However, particulate matter emissions from sources equipped with 
baghouses are not significantly affected by the ash inlet loading to 
the baghouse.\46\ This is further supported by the fact that this 
source is ranked eighth among the best performers. We conclude source 
349 is a best performer not because of its relatively low ash feed 
level, but rather because it is equipped with a well designed and 
operated baghouse. It is therefore appropriate to include this source 
in the MACT analysis.
---------------------------------------------------------------------------

    \46\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Vol I: Description of Source Categories,'' September 
2005, Section 3.2.2, for further discussion.
---------------------------------------------------------------------------

    Comment: Commenters state that source 341 should not be considered 
in the MACT analysis because it is a small laboratory waste burner that 
processes only 900 lbs/hr of waste. Commenters claim that more than 80 
percent of the waste profile is non-hazardous waste.
    Response: We approached this comment by asking if it would be 
appropriate to create a separate subcategory for source 341. We 
conclude it is not necessary to subcategorize hazardous waste 
incinerators based on the size of combustion units. This is because the 
ranking factors used to identify the relevant best performing sources 
are normalized in order to remove the influence that combustion unit 
size would otherwise have when identifying best performing sources. See 
part 4 section III.D below. Air pollution control system types (a 
ranking factor for particulate matter) are generally sized to match the 
corresponding volumetric gas flow rate in order to achieve a given 
control efficiency. The size of the combustor therefore does not 
influence a source's ability to achieve a given control efficiency. 
System removal efficiency and hazardous waste feed control MTECs 
(ranking factors used by the SRE/Feed methodology as described in part 
4 section III.B below) are also not influenced by the size of the 
combustor.\47\
---------------------------------------------------------------------------

    \47\ System removal efficiency is a measure of the amount of the 
pollutant that is removed from the flue combustion gas prior to 
being emitted and likewise is not influenced by the size of the 
combustor because back-end control systems are sized to achieve a 
given performance level. Hazardous waste feed control levels are 
normalized to remove the influence of combustor size by dividing 
each source's mass feed rate by its volumetric gas flowrate.
---------------------------------------------------------------------------

    Emission limitations are similarly normalized to remove the 
influence of combustion unit size by expressing the standards as 
emission concentration limits rather than as mass emission rate limits. 
See section III.D. This is illustrated in the following example. Assume 
there are two cement kilns side by side with similar designs, the only 
difference being one is twice the size of the other, producing twice as 
much clinker. They both have identical types of air pollution control 
systems (the larger source is equipped with a larger control device 
that is appropriately sized to accommodate the larger volumetric gas 
flow rates and achieves the same control efficiency as the smaller 
control device). If we were to assess performance based on HAP mass 
emission rates (e.g., pounds per hour), the smaller source would be the 
better performer because its mass emission rates would be half of the 
mass emission rate of the larger source, even though they both are 
achieving the same back-end control efficiency. Emission 
concentrations, on the other hand, are calculated by dividing the HAP 
mass emission rate (e.g., pounds per hour) by the volumetric gas 
flowrate (e.g., cubic feet per hour). In the above example, both 
sources would have identical HAP emission concentrations (the larger 
source has twice the mass emission rate, but twice the volumetric gas 
flow rate), accurately reflecting their identical control efficiency. 
Emission concentrations normalize the size of each source by accounting 
for volumetric gas flowate, which is directly tied to the amount of raw 
material each source processes (and subsequently the amount of product 
that is produced). This is a reason we point out that normalization 
eliminates the need to create subcategories based on unit size. See 
part four section III.D.
    Further, it would be difficult to determine an appropriate minimum 
size cutoff in which to base such a subcategorization determination. 
Such a subcategorization scheme could also yield nonsensical floor 
results, as was the case when we assessed subcategorizing commercial 
incinerators and on-site incinerators.\48\
---------------------------------------------------------------------------

    \48\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards'', September 
2005, Section 4.3.2 for further discussion.
---------------------------------------------------------------------------

    We have identified source 341 as the best performing source for 
particulate matter and low volatile metals. It is the single best 
performing source for these standards because it is equipped with a 
state-of-the-art baghouse.\49\ This source, which simultaneously feeds 
hazardous and nonhazardous wastes, conducted several emission tests 
that reflected different modes of operation. The amount of nonhazardous 
waste that was processed in the combustion unit varied across test 
conditions. We could not ascertain the exact amount of hazardous waste 
processed in the test condition that was used in the MACT analysis for 
low volatile metals because the test report stated the wastes that were 
processed were a mixture of hazardous and nonhazardous wastes, although 
we estimate that at least 26% of the waste processed was 
nonhazardous.\50\ We note that we are aware of several other 
incinerators that processed nonhazardous waste at levels greater than 
26 percent during their emission tests. We therefore do not believe 
this to be atypical operation that warrants subcategoriztion.
---------------------------------------------------------------------------

    \49\ See USEPA, ``Final Technical Support Document for the HWC 
MACT Standards, Volume I: Description of Source Categories'', 
September 2005, Section 3.2.1, for further discussion.
    \50\ See USEPA, ``Final Technical Support Document for the HWC 
MACT Standards, Volume I: Description of Source Categories'', 
September 2005, Section 2.1 for further discussion.
---------------------------------------------------------------------------

    Moreover, the fact that this source was feeding nonhazardous wastes 
does not result in atypically low hazardous waste low volatile metal 
feed control levels, as evidenced by the relative feed control ranking 
for this source of thirteenth among the 26 sources assessed in the MACT 
analysis. It also has the highest normalized hazardous waste feed 
control level among the best performing sources, and has the fifth best 
low volatile metal system removal efficiency among those same 26 
sources. We repeat that this source is being identified as the best 
performing source primarily because it is equipped with a highly 
efficient baghouse, not because it is feeding low levels of HAP metals 
attributable to its hazardous waste.
    Furthermore, this source is not the lowest emitting source in the 
database. There are two sources with similar, but slightly lower low 
volatile metal compliance test emissions (one commercial incinerator 
and one onsite, non-commercial incinerator). This provides further 
evidence that the

[[Page 59432]]

emissions from this source appropriately represent emissions of a 
relevant best performing source.
    Regarding the particulate matter standard, source 341 does not have 
atypically low ash feed rates as compared to other sources equipped 
with baghouses. Out of the nine best performing particulate matter 
sources for which we have ash feed information, this source ranks 
fourth (a ranking of one is indicative of the lowest ash feed rate). 
Nonetheless, as previously discussed, particulate matter emissions from 
sources equipped with baghouses are not significantly affected by the 
ash inlet loading to the baghouse. We note that particulate matter 
emissions from the second and third best performing source are not 
significantly different from this source, providing further evidence 
that this source is representative of the range of emissions exhibited 
by other well designed and operating incinerators equipped with 
baghouses.\51\
---------------------------------------------------------------------------

    \51\ Source 341 particulate matter emissions, after accounting 
for variability, equated to 0.0015 gr/dscf. The second and third 
ranked particulate matter sources emissions, considering 
variability, equated to 0.0018 and 0.0023 gr/dscf, respectively.
---------------------------------------------------------------------------

    Comment: Commenters state that sources 3018 and 3019 are identified 
as best performers for mercury emissions for incinerators. After 
evaluating the trial burn plans for these sources, the commenter 
believes the data should not be used to calculate the MACT floor 
because the spiking rate for mercury was extremely low for a compliance 
test. The ranking for feedrate is therefore unrepresentative. The 
commenter suggests that these test results should be characterized as 
``normal''.
    Response: We have verified that the emission tests performed for 
sources 3018 and 3019 reflect the upper range of mercury emissions that 
are not to be exceeded by these sources, and that their spiked mercury 
feed rates were back-calculated from a risk assessment. We therefore 
conclude that we properly characterized these emissions as compliance 
test emissions data because they reflect the emissions resulting from 
the upper bound of hazardous waste mercury feedrates from these 
sources.\52\ Consequently, these data are properly included with the 
other data used to calculate floor standards for mercury for 
incinerators.
---------------------------------------------------------------------------

    \52\ See February 11, 2005 memo to docket titled ``October 20 
Conference Call with Squibb Manufacturing regarding Source <greek-i> 
3018 and 3019''.
---------------------------------------------------------------------------

    Comment: Commenters state the trial burn plan for sources 3018 and 
3019 describes these units to be of similar design. Thus the difference 
in results between these two similar sources is indicative of 
additional variability above and beyond the run-to-run variability and 
should be assessed if the data are deemed usable at all.
    Response: We conclude both of these sources are in fact unique 
sources that should be assessed as individual sources for purposes of 
the MACT analysis. Although these sources are of similar design, we do 
not believe they are identical, in part because: (1) The facility 
itself conducted separate emission tests for the two units (rather than 
trying to avail itself of the `data in lieu' option, which could save 
it the expense of a second compliance test, the obvious inference being 
that the source or regulatory official regards the two units as 
different); and (2) discussions with facility representatives indicated 
these units are similar, but not identical.\53\ As a result, it would 
be inappropriate to assess emissions variability by combining the 
emissions of these two sources into one test condition given they are 
not identical units.
---------------------------------------------------------------------------

    \53\ Also see February 11, 2005 memo to docket titled ``October 
20 Conference Call with Squibb Manufacturing regarding Source 
<greek-i> 3018 and 3019''.
---------------------------------------------------------------------------

    Comment: Commenters state that emissions data from source 327 
should not be used to calculate dioxin/furan and mercury floors because 
they claim the carbon injection system did not appear to function 
properly during the test.
    Response: We agree with the commenters. We have determined that 
this source encountered problems with its carbon injection system 
during the emissions test from which the data were obtained and 
subsequently used in EPA's proposed MACT analysis. We have also 
verified that this source did not establish operating parameter limits 
for the carbon injection system as a result of this test.\54\ We 
therefore have excluded this mercury and dioxin data from the MACT 
analysis, and have instead used emissions data from an older test 
condition to represent this source's emissions.
---------------------------------------------------------------------------

    \54\ See July 15, 2005 memo to docket titled ``Telephone 
Conversation with Utah DEQ Regarding 2001 Clean Harbor Emission 
Test.''
---------------------------------------------------------------------------

    Comment: Commenters state that the emissions data from source 3006 
were based on a miniburn to determine how close the unit was to 
achieving the interim MACT standards. The commenter questions whether 
these data should be used for purposes of calculating MACT standards.
    Response: The fact that a source conducts a voluntary emissions 
test (e.g., a miniburn) to determine how close it is operating to 
upcoming emission standards does not necessarily lead us to conclude 
that the emission data are inappropriate for purposes of calculating 
MACT standards. However, since proposal, we have determined that this 
source did not measure cadmium emissions during this emissions test. As 
a result, we conclude the semivolatile metal emissions data from this 
source should not be used in the MACT standard calculation for 
semivolatile metals because the data do not represent the source's 
combined emissions of lead and cadmium.

II. Affected Sources

A. Area Source Boilers and Hydrochloric Acid Production Furnaces

    Comment: Five commenters state that the area sources subject to the 
proposed rule are negligible contributors to 112(c)(6) HAP emissions 
and should not be subject to major source standards for 112(c)(6) HAP. 
Commenters note that requiring compliance with MACT for 112(c)(6) HAP 
and RCRA for other toxic pollutants is more complicated and burdensome 
for sources than complying only with RCRA. Although an area source can 
choose to become regulated as a major source in order to reduce some 
RCRA requirements, they would become subject to more onerous emissions 
limits under Subpart EEE and the other MACT requirements.
    One of these commenters states that subjecting an area source to 
major source standards under 112(c)(6) sends a negative message to 
industry that EPA does not value emissions reduction and/or chemical 
substitution, or other methods used by area sources to achieve that 
status. EPA is no longer providing any incentive for sources to take 
such difficult yet environmentally beneficial steps to become an area 
source. Imposing Title V permitting requirements on an entire facility 
that operates as an area source of hazardous air pollutants (HAPs) will 
impose an unfair and undue burden on the facility.
    Another of these commenters states that section 112(c)(6) requires 
in pertinent part that EPA list categories and subcategories of sources 
assuring that sources accounting for not less than 90% of the aggregate 
emissions of each pollutant (specified in 112(c)(6)) are subject to 
standards under Section 112(d)(2) or (d)(4). In 1998, EPA published a 
notice identifying the list of source categories accounting for the 
section 112(c)(6) HAP emissions and to be regulated under section 
112(d) to meet the 90% requirement. (63 FR 17838) At the time, EPA 
acknowledged that MACT standards for a number of the source categories 
had not yet been promulgated, and stated that when the

[[Page 59433]]

regulations for each of those categories are developed, EPA will 
analyze the data specific to those sources and determine, under Section 
112(d), in what manner requirements will be established. EPA also 
stated that:

    ``Some area categories may be negligible contributors to the 90% 
goal, and as such pose unwarranted burdens for subjecting to 
standards. These trivial source categories will be removed from the 
listing as they are evaluated since they will not contribute 
significantly to the 90% goal.'' (63 FR 17841)

    The commenter believes the ``two or fewer'' area source boilers 
identified by EPA in the present rulemaking are ``negligible 
contributors'' to the 90% goal and therefore, should not be required to 
adopt the same MACT emission limitations and requirements as major 
sources of the 112(c)(6) pollutants. The commenter believes EPA's 
decision to subject area source boilers and hydrochloric acid 
production furnaces is incorrect, unsupported by the administrative 
record, and therefore arbitrary and capricious.
    One commenter states that, if EPA regulates area sources, it should 
significantly reduce the administrative burden for area sources by: 
exempting them from Title V provisions for Subpart EEE requirements; 
exempting them from compliance with the General Provisions of 63 
Subpart A; limiting them to a one-time comprehensive performance test; 
or limiting other applicable requirements.
    Response: We continue to believe that boiler and hydrochloric acid 
furnace area sources warrant regulation under the major source MACT 
standards for mercury, dioxin/furan, carbon monoxide/hydrocarbons, and 
destruction and removal efficiency pursuant to section 112(c)(6).
    As discussed at proposal (69 FR at 21212), section 112(c)(6) of the 
CAA requires EPA to list and promulgate section 112(d)(2) or (d)(4) 
standards (i.e., standards reflecting MACT) for categories and 
subcategories of sources emitting seven specific pollutants. Five of 
those listed pollutants are emitted by boilers and hydrochloric acid 
production furnaces: mercury, 2,3,7,8-tetrachlorodibenzofuran, 2,3,7,8-
tetrachlorodibenzo-p-dioxin, polycyclic organic matter, and 
polychlorinated biphenyls.
    As discussed below, EPA must assure that source categories 
accounting for not less than 90 percent of the aggregated emissions of 
each enumerated pollutant are subject to MACT standards (and of course 
is not prohibited from requiring more than 90 percent of aggregated 
emissions to be controlled by MACT standards). Congress singled out the 
pollutants in section 112(c)(6) as being of ``'specific concern''' not 
just because of their toxicity but because of their propensity to cause 
substantial harm to human health and the environment via indirect 
exposure pathways (i.e., from the air through other media, such as 
water, soil, food uptake, etc.). Furthermore, these pollutants have 
exhibited special potential to bioaccumulate, causing pervasive 
environmental harm in biota and, ultimately, human health risks.
    Section 112(c)(6) of the CAA requires EPA to list categories and 
subcategories of sources of seven specified pollutants to assure that 
sources accounting for not less than 90 percent of the aggregate 
emissions of each such pollutant are subject to standards under CAA 
section 112(d)(2) or 112(d)(4). In 1998, EPA issued the list of source 
categories pursuant to section 112(c)(6), and that list is published at 
63 Fed. Reg. 17838, 17849, Table 2 (April 10, 1998).
    In the 1998 listing, EPA identified the following three 
subcategories of the HWC source category that emit one or more of the 
seven section 112(c)(6) pollutants: (1) Hazardous waste incinerators--
(emit mercury, dioxin, furans, polycyclic organic matter (POM) and 
polychlorinated biphenyls (PCBs)); (2) Portland cement manufacture: 
hazardous waste kilns--(emit mercury, dioxin, furans, and POM); and (3) 
lightweight aggregate kilns: hazardous waste kilns--(emit dioxin, 
furans, and mercury). These three subcategories are all subject to 
today's rule, which is issued pursuant to CAA section 112(d)(2). As 
explained below, the HWC NESHAP effectively controls emissions of the 
identified section 112(c)(6) pollutants from the identified 
subcategories. Accordingly, EPA considers the sources in these three 
subcategories as being ``subject to standards'' for purposes of section 
112(c)(6).
    Specifically, with regard to hazardous waste-burning incinerators, 
cement kilns, and lightweight aggregate kilns, EPA is adopting in this 
final rule MACT standards for mercury and dioxins/furans. EPA has 
already adopted MACT standards for control of POM and PCBs emitted by 
these sources in the 1999 rule, which standards were not reopened or 
reconsidered in this rulemaking. These standards are the CO/HC 
standards, which in combination with the Destruction Removal Efficiency 
(DRE) requirement, assure that these sources operate continuously under 
good combustion conditions which inhibit formation of POM and PCBs as 
combustion by-products, or destroy these HAP if they are present in the 
wastes being combusted.\55\ See discussion in Part Four, Sections V.A 
and V.B of this preamble.
---------------------------------------------------------------------------

    \55\ Courts have repeatedly upheld EPA's authority under CAA 
section 112(d) to use a surrogate to regulate hazardous pollutants 
if it is reasonable to do so. See, e.g., National Lime, 233 F. 3d at 
637 (holding that EPA properly used particulate matter as a 
surrogate for HAP metals).
---------------------------------------------------------------------------

    The HWC NESHAP also applies to hazardous waste-burning boilers and 
hydrochloric acid production furnaces. In particular, for these boilers 
and furnaces, this rule addresses emissions of dioxin/furan, mercury, 
POM and PCBs either through specific numeric standards for the 
identified HAP, or through standards for surrogate pollutants which 
control emissions of the identified HAP.
    We estimate that approximately 620 pounds of mercury are emitted 
annually in aggregate from hazardous waste burning boilers in the 
United States.\56\ Also, we estimate that hazardous waste burning 
boilers and hydrochloric acid production furnaces emit in aggregate 
approximately 2.3 and 0.2 grams TEQ per year of dioxin/furan, 
respectively. Controlling emissions of these HAP from area sources 
consequently reduces emissions of these HAP through application of MACT 
standards. We note that only major source boilers and hydrochloric acid 
furnaces are subject to the full suite of subpart EEE emission 
standards.\57\ Section 112(c)(3) of the CAA requires us to subject area 
sources to the full suite of standards applicable to major sources if 
we find ``a threat of adverse effects to human health or the 
environment'' that warrants such action. We cannot make this finding 
for area source boilers and halogen acid production furnaces. 69 FR at 
21212. Consequently, as proposed, area sources in these categories 
would be subject only to the MACT standards for mercury, dioxin/furan, 
and polycyclic

[[Page 59434]]

organic matter and polychlorinated biphenyls (through the surrogate 
standards for carbon monoxide/hydrocarbons and destruction and removal 
efficiency) to control the HAP enumerated in section 112(c)(6). RCRA 
standards under Part 266, Subpart H for particulate matter, metals 
other than mercury, and hydrogen chloride and chlorine gas would 
continue to apply to these area sources unless an area source elects to 
comply with the major source standards in lieu of the RCRA standards. 
See Sec.  266.100(b)(3) and the revisions to Sec. Sec.  270.22 and 
270.66.
---------------------------------------------------------------------------

    \56\ See USEPA ``Technical Support Document for HWC MACT 
Standards, Volume V: Emission Estimates and Engineering Costs,'' 
September, 2005, Section 3.
    \57\ We note that as a practical matter, however, the same MACT 
standards apply to both major and area source HCl production 
furnaces. This is because major sources are subject to the following 
standards: CO/HC, DRE, and total chlorine. Because the CO/HC and DRE 
standards are surrogates to control dioxin/furan, and the total 
chlorine standard is a surrogate to control metal HAP, area sources 
are subject to the same standards that address dioxin/furan, 
polycyclic organic matter, polychlorinated biphenyls, and mercury. 
There is an enforcement difference between the requirements, 
however. For area sources, an exceedance of the total chlorine 
standard (or failure to ensure that compliance is maintained) 
relates to control of mercury only while for a major source, the 
same failure relates to control of mercury, other metal HAP, and HCl 
and chlorine.
---------------------------------------------------------------------------

    Commenters refer to the ``two or fewer'' potential area source 
boilers we identified at proposal as ``negligible contributors'' and, 
therefore, conclude that these area sources should not be subject to 
major source standards for emission of these HAPs. Commenters did not 
quantify the amount of emissions from area sources, and did not even 
identify how many area sources are at issue. We do not know how many 
boilers and hydrochloric acid furnaces are area sources. We apparently 
underestimated the number given that four companies commented on the 
proposed rule saying that area sources should not be subject to major 
source standards for mercury, dioxin/furan, PCBs, and polycyclic 
organic matter, and one of those companies indicates it operates 
multiple area sources. Consequently, we continue to believe that area 
sources in these categories may have the potential to emit more than 
negligible levels of these HAP.
    We also note that the major source standards are tailored to 
minimize the compliance burden for sources that emit low levels of HAP. 
Commenters raise concerns about applying the major source standards for 
HAP enumerated in section 112(c)(6) to liquid fuel boiler area sources. 
The emission standard compliance burden for liquid fuel boilers that 
have the potential to emit only low levels of mercury, dioxin/furan, 
and polycyclic organic matter is minimal. For example, sources that 
emit low levels of mercury because their feedstreams have low levels of 
mercury can elect to comply with the mercury emission standard by 
documenting that the mercury in feedstreams will not exceed the 
standard assuming zero removal by emission control equipment. We note 
that 75% of the liquid fuel boilers in our data base, and the two 
boilers cited by commenters, do not have emission control devices.
    The compliance burden for the major source standards for dioxin/
furan and for the surrogates to control other polycyclic organic 
matter--carbon monoxide/hydrocarbons and destruction and removal 
efficiency (DRE)--should also be minimal for area source liquid fuel 
boilers. The dioxin/furan standard applicable to the 90% of liquid fuel 
boilers with wet or no air pollution control equipment is compliance 
with the carbon monoxide/hydrocarbon standard and the DRE standard. 
Liquid fuel boilers already comply with these same standards under 
RCRA. The surrogate standards to control other polycyclic organic 
matter are also the carbon monoxide/hydrocarbon and DRE standards. 
Finally, we note that the DRE requirement under Subpart EEE is less 
burdensome than the DRE requirement under RCRA. Under Subpart EEE, a 
source needs to conduct a one-time only DRE test, provided that design 
and operation does not change in a manner than could adversely affect 
DRE. Under RCRA, the DRE test must be conducted each time the RCRA 
permit is renewed.
    The incremental compliance burden associated with the other Subpart 
EEE major source requirements, such as the operations and maintenance 
plan, the startup, shutdown, and malfunction plan, operator training, 
and the automatic waste feed cutoff system should also be minimal for 
liquid fuel boilers without an emission control device. In addition, 
most of the requirements are either identical to or very similar to 
requirements under RCRA with which these area sources are already 
complying.\58\
---------------------------------------------------------------------------

    \58\ RCRA, 40 CFR Part 264 requirements that are similar to MACT 
requirements include: the general inspection requirements and 
personnel training requirements of Subpart B; the preparedness and 
prevention requirements of Subpart C, including design and operation 
of facility, testing and maintenance of equipment, and access to 
communications or alarm system; the contingency plan and emergency 
procedures requirements of Subpart D; and the operating requirements 
and monitoring and inspection requirements of Subpart O.
---------------------------------------------------------------------------

B. Boilers Eligible for the RCRA Low Risk Waste Exemption

    Comment: Several commenters state that EPA should exempt those 
boilers that qualify as Low Risk Waste Exemption (LRWE) burners under 
the RCRA Boiler and Industrial Furnace Rule at Sec.  266.109 from the 
MACT particulate matter and destruction and removal efficiency (DRE) 
standards because EPA has not: (1) Made a demonstration that the data 
used to provide the exemption to low risk burners under RCRA is no 
longer valid; or (2) established in the affirmative that regulating 
these units will provide any benefit to human, health and the 
environment. Commenters believe that regulating LRWE units under 
Subpart EEE is unnecessary and inconsistent with RCRA subtitle C and 
more importantly, appears to be controlling LRWE units for control's 
sake.
    Commenters also state that EPA has not properly addressed the 
requirements of CAA section 112(n)(7) regarding the inconsistency 
between the requirements for Low Risk Waste Exempt (LRWE) units under 
RCRA and those of Subpart EEE. The purported purpose of section 
112(n)(7) is to allow EPA to avoid imposing additional emission 
limitations on a source category subcategory when such limitations 
would be unnecessary and duplicative.
    In addition, commenters state that the costs associated with this 
MACT are much more than improved feed control or better back-end 
control. This proposed rule also requires substantial dollar investment 
in improved data acquisition, computer controls and recordkeeping 
systems, performance testing, training, development of plans, and other 
regulatory requirements.
    Response: Boilers and hydrochloric acid production furnaces that 
currently qualify for the RCRA Sec.  266.109 low risk waste exemption 
are not exempt from Subpart EEE under the final rule.
    The Administrator does not have the authority under CAA section 
112(d) to exempt sources that comply with RCRA Sec.  266.109. Indeed, 
there is no necessary connection between the two provisions, since one 
is technology-based and the other is risk-based. CAA section 112(d)(2) 
requires the Administrator to establish technology-based emission 
standards, standards that require the maximum degree of reduction in 
emissions that is deemed achievable. Although section 112(d)(4) gives 
the Administrator the authority to establish health-based emission 
standards in lieu of the MACT standards for pollutants for which a 
health threshold has been established, we cannot use that authority to 
develop health-based standards for sources that comply with RCRA Sec.  
266.109 because those sources emit HAP for which a health threshold has 
not been established.
    The final rule complies fully with CAA section 112(n)(7) by 
coordinating applicability of the RCRA and CAA requirements and 
precluding dual requirements. For example, RCRA requirements that are 
duplicative of MACT requirements will be removed from the RCRA 
operating permit when the permitting authority issues a certification 
of compliance after the source submits a Notification of Compliance.
    We also note that the MACT standards are tailored to impose

[[Page 59435]]

minimal burden on sources that have low emissions of HAP. The 
particulate matter emission standard and associated testing can be 
waived (similar to the Sec.  266.109 exemption) for boilers that elect 
to document that emissions of total metal HAP do not exceed the limits 
provided by Sec.  63.1206(b)(14). Hydrochloric acid production furnaces 
are not subject to a particulate matter emission standard.
    The compliance burden with the destruction and removal efficiency 
(DRE) standard is also minimal given that it is a one-time test, 
provided that the source does not change its design or operation in a 
manner that would adversely affect DRE. In addition, the compliance 
burden for sources with low levels of metals in their feedstreams is 
minimal. Sources can document compliance with the metals emission 
standards by assuming all metals in the feed are emitted (i.e., by 
assuming zero system removal efficiency). Under this procedure, boilers 
burning relatively clean wastes are not required to conduct a 
performance test to document compliance with the metals emission 
standards.
    Further, we note that the MACT standard to control organic HAP 
emissions other than dioxin/furan is the same as the RCRA standard--
demonstrating good combustion conditions by complying with a carbon 
monoxide standard of 100 ppmv.
    Finally, we note that the ancillary requirements under MACT (e.g., 
personnel training; operating and maintenance plan; startup, shutdown, 
and malfunction plan) should not pose substantially higher costs than 
similar requirements under RCRA. See response to comment in Section A 
above. To the extent that compliance costs increase, we have accounted 
for those costs in our estimates of the cost of the final rule.\59\
---------------------------------------------------------------------------

    \59\ USEPA ``Technical Support Document for HWC MACT Standards, 
Volume V: Emission Estimates and Engineering Costs,'' September, 
2005.
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C. Mobile Incinerators

    Comment: A mobile incinerator used as a directly-fired thermal 
desorption unit at a Superfund remediation site should not be an 
affected source under this rule.
    Response: EPA is not determining or changing the applicability of 
any hazardous waste burning unit under today's rule. A combustion unit 
that treats hazardous waste and meets the definition of incinerator at 
40 CFR 260.10 is an affected source under this rule. 40 CFR part 63 
also defines a source as any building, structure, facility, or 
installation which emits or may emit any air pollutant. A mobile 
incinerator at a remediation site meets this definition.
    Comment: One commenter states that a subcategory with different 
standards must be created for mobile incinerators, or the standards for 
incinerators must be calculated using actual emissions data from mobile 
units.
    Response: EPA did not have any emissions data from mobile 
incinerators in the database for the proposed rule. That data base was 
developed over many years with ample opportunity for public comment. We 
developed a data base for incinerators to support the 1996 proposed 
rule (61 FR 17358) and noticed that data base for public comment on 
January 7, 1997 (64 FR 52828). We updated that data base in July 2002, 
and noticed the revised data base for public comment (67 FR 44452). We 
used that revised data base to support the proposed rule. We did not 
receive comments providing data for mobile incinerators as a result of 
either public notice.
    One commenter on the proposed rule provided a summary of emissions 
data from one test at a mobile incinerator. The commenter suggested 
that the data support its view that its mobile incinerator is unique 
and that EPA should consider subcategorizing incinerators according to 
mobile incinerators versus other incinerators. We analyzed these data 
and conclude that the final standards are readily achievable by this 
source. Moreover, as explained elsewhere, EPA's approach to assess the 
need for subcategorization is to apply a statistical test to determine 
whether the emissions data are statistically different from the 
remaining group. Given that owners and operators of mobile incinerators 
have not provided emissions data prior to proposal, and that the 
commenter provides summarized data for only one mobile incinerator 
(which also indicate that the source can achieve the emission standards 
in the final rule); we are not compelled to gather additional 
information, particularly given our time constraints to promulgate the 
final rule under a court-ordered deadline.
    Comment: In support of subcategorizing mobile incinerators, 
commenters state that mobile thermal treatment systems are 
substantially different from hazardous waste incinerators. They are 
much smaller in size, firing capacity rate, refractory lining, and 
operating temperatures. Most of them treat contaminated soil, so have 
very high particulate feedrate loading with high ash content, rapid 
kiln rotation rate, and counter-current flow design like cement kilns. 
This results in high particulate matter emissions. They operate only 
for a short duration at a site (usually less than 6 months), and have 
no flexibility with regard to their waste feed.
    Response: We recognize that there is variability between various 
sources' with regard to size, capacity, operating temperatures etc., 
and so we applied a statistical test to assess the need of 
subcategorization, as has been discussed above. The emissions data 
provided by the commenter also indicate the source can achieve the 
final standards. The soil entrained in desorber off-gases of mobile 
incinerators has a relatively large particle size, and is very easy to 
capture with conventional particulate control systems (such as a fabric 
filter) used by the incinerators.
    Comment: Since mobile incinerators are relocated from site to site, 
the new source standard should not apply based on the erection date of 
the mobile unit.
    Response: We are not changing the applicability of a new or 
reconstructed source designation in this rulemaking. The relocation 
issue is addressed in the definition of ``construction'' in 40 CFR 
Section 63.2, which states: ``Construction does not include the removal 
of all equipment comprising an affected source from an existing 
location and the reinstallation of such equipment at a new location * * 
*'' (emphasis added). Therefore, the relocation of an existing Subpart 
EEE affected source, such as a mobile incinerator, would not result in 
that mobile incinerator becoming a ``new'' source. Keep in mind also 
that the relocation exemption only applies to affected sources. If a 
mobile incinerator is relocated from an R&D facility (where the unit is 
not an affected source per Table 1 to Section 63.1200) to a location 
where the mobile incinerator would become an affected source, the 
relocation exemption within the definition of ``construction'' would 
not apply and the mobile incinerator would be a ``new'' source. Also, 
with regard to leased sources, the owner/operator of the facility is 
responsible for all affected sources operating at his/her facility 
regardless of whether the sources are owned or leased. The owner or 
operator should obtain from the leasing company all relevant 
information pertaining to the affected source in order to be able to 
demonstrate that the affected source is operating in compliance with 
the appropriate standards.

III. Floor Approaches

    In this section we discuss comments addressing methodologies used 
in this rule for determining MACT floors. We address comments relating 
both to

[[Page 59436]]

general, overarching issues and to the specific methodologies used in 
the rule. Our most important point is that the methodologies EPA 
selected reasonably estimate the performance of the best performing 
sources by best accounting for these sources' total variability.

A. Variability

1. Authority To Consider Emissions Variability
    Comment: Many commenters concur with our approach to account for 
emissions variability while several commenters believe that our 
approach does not adequately account for emissions variability. See 
discussions on separate topics below. One commenter, however, states 
that use of variability factors (however derived) is inherently 
unlawful and arbitrary and capricious. The commenter notes that, 
because floors for existing sources must reflect the ``average'' 
emission level achieved by the relevant best performing sources, they 
cannot reflect any worse levels of performance from the best 
performers. Indeed, the argument is that the Clean Air Act already 
accounts for variability by requiring EPA to base existing source 
floors on the average emission level achieved by the best performing 
sources.
    The commenter continues by stating that EPA has added variability 
factors both to each individual source's performance and to the 
collective performance of the alleged best performers, in each case 
purporting to find an emission level that the individual or group would 
meet ninety-nine times out of 100 future emission tests. Thus, EPA 
ignores sources' measured performance in favor of the theoretical worst 
performance that might ever be expected from them. By looking to the 
best performers' worst performance rather than their average 
performance, EPA would set weaker floors than the Clean Air Act allows.
    In addition, the commenter notes that EPA's approach to account for 
emissions variability is arbitrary and capricious because EPA never 
explains why it chose the 99th percentile for its variability 
adjustments rather than some other percentile.
    Finally, the commenter notes that EPA appears to indicate that its 
variability analysis would either be applied to variation between 
sources or would affect EPA's statistical analysis of the variation 
between sources. The commenter states that any attempt by EPA to add a 
variability factor to adjust for intersource variability is unlawful 
and arbitrary and capricious.
    Response: Our response explains our approach to estimating best 
performing sources' variability and addresses the following issues: (1) 
Considering the variability in each source's performance is necessary 
to identify the best performing sources and their level of performance; 
(2) EPA reasonably considered variability in ranking sources to 
identify the best performers and in considering the range of best 
performing sources' performance over time to identify an emission level 
that the average of those sources can achieve; (3) considering 
variability at the 99th percentile level is reasonable; (4) considering 
intersource variability by pooling run-to-run variability is 
appropriate; and (5) compliance test conditions do not fully reflect 
all of best performing sources' performance variability.
    a. Variability Must Be Considered. Variability in each source's 
performance must be considered at the outset in identifying the best 
performing sources. This is simply another way of saying that best 
performers are those that perform best over time (i.e. day-in, day-
out), a reasonable approach. This approach not only reasonably reflects 
the statutory language, but also furthers the ultimate objective of 
section 112 which is to reduce risk from exposure to HAP. Since most of 
the risk from exposure to emissions from this source category is 
associated with chronic exposure to HAP (see Part 1 section VI above), 
assessing a source's performance over time by accounting for 
variability is reasonable and appropriate.
    For similar reasons, variability must be considered in ascertaining 
these sources' level of performance. Floors for existing sources must 
reflect ``the average emission limitation achieved by the best 
performing 12 percent'' of sources, and for new sources, must reflect 
``the emission control that is achieved in practice by the best 
controlled source.'' Section 112 (d) (3). EPA construes these 
requirements as meaning achievable over time, since sources are 
required to achieve the standards at all times. This interpretation has 
strong support in the case law. See Sierra Club v. EPA, 167 F. 3d 658, 
665 (D.C. Cir. 1999), stating that ``EPA would be justified in setting 
the floors at a level that is a reasonable estimate of the performance 
of the `best controlled similar unit' under the worst reasonably 
foreseeable circumstances. It is reasonable to suppose that if an 
emissions standard is as stringent as `the emissions control that is 
achieved in practice' by a particular unit, then that particular unit 
will not violate the standard. This only results if `achieved in 
practice' is interpreted to mean `achieved under the worst foreseeable 
circumstances'; see also National Lime Ass'n v. EPA, 627 F. 2d 416, 431 
n. 46 (D.C. Cir. 1980) (where a statute requires that a standard be 
`achievable,' it must be achievable under ``the most adverse 
circumstances which can reasonably be expected to recur'');
    The court has further indicated that EPA is to account for 
variability in assessing sources' performance for purposes of 
establishing floors, and stated that this assessment may require EPA to 
make reasonable estimates of performance of best performing sources. 
CKRC, 255 F. 3d at 865-66; Mossville Environmental Action Now v. EPA, 
370 F. 3d 1232, 1242 (D.C. Cir. 2004)(maximum daily variability must be 
accounted for when establishing MACT floors).\60\ Indeed, EPA's error 
in CKRC was not in estimating best performing sources' variability, but 
in using an unreasonable means of doing so. CKRC, 255 F. 3d at 866; 
Mossville, 370 F. 3d at 1241.
---------------------------------------------------------------------------

    \60\ See also Chemical Manufacturers Ass'n v. EPA, 870 F. 2d 
177, 228 (5th Cir. 1989) (``The same plant using the same treatment 
method to remove the same toxic does not always achieve the same 
result. Tests conducted one day may show a different concentration 
of the same toxic than are shown by the same test the next day. This 
variability may be due to the inherent inaccuracy of analytical 
testing, (i.e. `analytical variability,' or to routine fluctuations 
in a plant's treatment performance.'')
---------------------------------------------------------------------------

    Since the emission standards in today's rule must be met at all 
times, the standards need to account for performance variability that 
could occur on any single day of these sources' operation (assuming 
proper design and operation). See Mossville, 370 F. 3d at 1242 
(upholding MACT floor because it was established at a level that took 
into account sources' long term performance, not just performance on 
individual days). Moreover, since EPA's database consists of single 
data points (because there are no continuous emission monitors for HAPs 
in stack emissions), EPA must of necessity estimate long-term 
performance, including daily maximum performance, from this limited set 
of short term data.
    b. EPA Reasonably Considered Variability in Ranking Sources to 
Identify the Best Performers and in Considering the Range of Best 
Performing Sources' Performance Over Time to Identify an Emission Level 
that the Average of Those Sources Can Achieve. (1) Selecting Best 
Performing Sources. Each of the floor methodologies used in the rule 
considers various factors in ranking which sources are the best 
performing. For each methodology, we therefore consider the 
quantifiable variability of

[[Page 59437]]

the ranking factors in determining which are the best performing 
sources. 69 FR at 21230-31. Specifically, we assess run-to-run 
variability (normally the only type of variability which we can 
quantify) of the factors used under each methodology to rank best 
performers. Where SRE/Feed is the ranking methodology, we thus assess 
run-to-run variability of hazardous waste HAP feedrate and of system 
removal efficiency. Where ranking is based on sources' emissions (the 
straight emissions methodology), we assess the run-to-run variability 
of emission levels. Where we use the air pollution control device 
methodology for ranking, we assess the run-to-run variability of 
emissions of the lowest-emitting sources (as we do for straight 
emissions) using the best air pollution control devices. For 
hydrochloric acid production furnaces, we assess the run-to-run 
variability of total chlorine system removal efficiency. Id.\61\
---------------------------------------------------------------------------

    \61\ These ranking methodologies are discussed later in this 
section of the preamble, and in USEPA, ``Technical Support Document 
for HWC MACT Standards, Volume III: Selection of MACT Standards,'' 
September 2005, Section 7.
---------------------------------------------------------------------------

    To account for run-to-run variability in these ranking factors, we 
rank sources by the 99th percentile upper prediction limit (UPL99). The 
UPL99 is an estimate of the value that the source would achieve in 99 
of 100 future tests if it could replicate the operating conditions of 
the compliance test. Id. at 21231.
    (2). Assessing the Best Performers' Level of Performance Over Time. 
Once we identify the best performing sources, we need to consider their 
emissions variability to establish a floor level that the average of 
the best performing sources can achieve day-in, day-out. There are two 
components of emissions variability that must be considered: run-to-run 
variability and test-to-test variability. Run-to-run emissions 
variability encompasses variability in individual runs comprising the 
compliance tests, and includes uncertainties in correlation of 
monitoring parameters and emissions, and imprecision of stack test 
methods and laboratory analyses. See 69 FR at 21232.\62\ Test-to-test 
emissions variability is the variability that exists between multiple 
compliance tests conducted at different times and includes the 
variability in control device collection efficiency caused by testing 
at different points in the maintenance cycle of the emission control 
device \63\, and the variability caused by other uncontrollable factors 
such as using a different stack testing crew or different analytical 
laboratory, and by different weather conditions (e.g., ambient moisture 
and temperature) that may affect measurements.
---------------------------------------------------------------------------

    \62\ Analytic variability exists, and normally must be accounted 
for in establishing technology-based standards based on performance 
of the best-performing plants. Chemical Manufacturers Ass'n v. EPA, 
870 F. 2d at 230.
    \63\ There are myriad factors that affect performance of an 
emissions control device. These factors change over time, including 
during the maintenance cycle of the device, such that it is 
virtually impossible to conduct future compliance tests under 
conditions that replicate the performance of the control device. See 
USEPA, ``Technical Support Document for HWC MACT Standards, Volume 
III: Selection of MACT Standards,'' September 2005, Section 5.3.
---------------------------------------------------------------------------

    We are able to quantify run-to-run variability. We do so by 
applying a 99th percentile modified upper prediction limit to the 
averaged emissions of the best performing sources. Id. at 21233 and 
Technical Support Document Volume III section 7.2. The modified upper 
prediction limit accounts for run-to-run variability of the best 
performers by pooling their run variance (i.e., within-test condition 
variability).\64\ See Chemical Manufacturer's Ass'n v EPA, 870 F. 2d 
177, 228 (5th Cir. 1989) (upholding use of a variability factor 
derived, as here, by pooling the performance variability of the best 
performing plants). Using this approach, we ensure that the average of 
the best performing sources will be able to achieve the floor in 99 of 
100 future performance tests, assuming these best performing sources 
could replicate their performance when attempting to operate under 
identical conditions to those used for the compliance test establishing 
the source as best performing. As just noted, we call this value the 
modified UPL 99.
---------------------------------------------------------------------------

    \64\ We note that the Agency used a statistical approach when 
proposing the NESHAP for Electric Utility Steam Generating Units. 
See memo from William Maxwell, EPA, to Utility MACT Project Files, 
entitled, ``Analysis of variability in determining MACT floor for 
coal-fired electric utility steam generating units,'' dated Nov. 26, 
2003, Docket A-92-55.
---------------------------------------------------------------------------

    The only instance in which we are able to quantify test-to-test 
variability (as noted above, the other significant component of total 
operating variability) is for fabric filters (baghouses) when used to 
control emissions of particulate matter. The modified UPL 99 in these 
instances reflects not only run-to-run variability, but test-to-test 
variability as well. That total variability is expressed by the 
Universal Variability Factor which is derived from analyzing long-term 
variability in particulate matter emissions for best performing sources 
across all of the source categories sources that are equipped with 
fabric filters. 69 FR at 21233. See also the discussion below in 
Section III.A.2.
    Test-to-test variability must be accounted for in other instances 
as well, however. It follows that if the performance of most efficient 
fabric filters varies over time relative to particulate matter 
emissions, then so does their performance relative to the non-mercury 
metal HAP emissions. We also believe that particulate matter emissions 
variability from sources equipped with back-end controls other than 
fabric filters also exists, and is furthermore likely to be higher than 
what was calculated for fabric filters because there are more 
uncertainties associated with the correlations between operating 
parameter limits and control efficiency for these devices.\65\ Again, 
it clearly follows that if the performance of these other control 
devices varies relative to particulate matter emissions (perhaps even 
more than what has already been quantified for fabric filters), then so 
does their performance relative to the non-mercury metal HAP emissions.
---------------------------------------------------------------------------

    \65\ For example, sources equipped with electrostatic 
precipitators generally establish multiple operating limits to best 
assure compliance with the emission standard (feed control limits, 
power input limits, etc.). There is not an exact correlation between 
emission levels and operating levels because there are several 
factors that can affect the control efficiency of these air 
pollution control systems, such as variations in inlet loads, power 
inputs, spark rates, humidity, as well as particle resistivity. See 
USEPA, ``Technical Support Document for the HWC MACT Standards, 
Volume III: Selection of MACT Standards,'' September 2005, Sections 
16 and 17.
---------------------------------------------------------------------------

    Although we cannot quantify this test-to-test variability, we can 
document its existence and its significance. We conducted two parallel 
analyses examining all situations where we had multiple test conditions 
for the sources ranked as best performing performing (examining 
separate pools for best performing sources under both the straight 
emissions and SRE/feed ranking methodologies). These analyses showed 
that these sources' emissions do in fact vary over time, sometimes 
significantly. In many instances sources had poorer system removal 
efficiencies and higher emission levels than those in the compliance 
test used to identify the source as best performing. We further 
projected that in many instances these best performing sources would 
not achieve their own UPL 99, the statistically determined prediction 
limit which captures 99 out of 100 future three-run test averages for 
the source, if they were to operate at the poorer system removal 
efficiency of its earlier test and used the federate of its later 
(best-performing) compliance test. This is significant because the UPL 
99 reflects all of a source's run-to-run

[[Page 59438]]

variability. Failure to meet the UPL 99 thus shows both that further 
variability exists, namely test-to-test variability, and that it is a 
significant component of total variability. We obtained similar results 
when we projected best performing sources' performance based on each of 
these sources' overall system removal efficiency obtained by pooling 
the removal efficiencies of all of its tests. In many instances, 
moreover, these projected levels exceeded floor levels calculated by 
using the straight emissions approach, which ranks best performers as 
those with the lowest emission levels. This point is discussed further 
in Section III.B below. EPA's analysis is set out in detail in chapters 
16 and 17 of Volume III of the Technical Support Document.\66\
---------------------------------------------------------------------------

    \66\ We explain in those sections that these projections assume 
that system removal efficiencies are constant across differing HAP 
federates and that the sources' historical (poorer) system removal 
efficiencies were not the primary result of operating at poorer 
``controllable'' conditions relative to the most recent test 
condition. These are reasonable assumptions, as explained in section 
17. 3 of Volume III of the Technical Support Document, although 
these assumptions also create a measure of uncertainty regarding the 
emissions projections.
---------------------------------------------------------------------------

    EPA's conclusion is that total variability includes both run-to-run 
and test-to-test variability, and that both must be accounted for in 
determining which are the best performing sources and what are their 
levels of performance over time. As explained in the following Sections 
B and C, EPA has accordingly adopted floor methodologies which account 
for this total variability either quantitatively or qualitatively. The 
approach advocated by the commenter simply ignores that variability 
exists. Since this approach is contrary to both fact and law, EPA is 
not adopting it.
    c. Quantifying Run-to-Run Variability at the 99th Percentile Level 
Is Reasonable. We selected the 99% prediction limit to ensure a 
reasonable level `` namely the 99th percentile--of achievability for 
sources designed and operated to achieve emission levels equal to or 
better than the average of the best performing sources.\67\ Because of 
the randomness of the emission values, there is an associated 
probability of the average of the best performing sources, and 
similarly designed and operated sources, not passing the performance 
test conducted under the same conditions.\68\ At a 99% confidence 
level, the average of the best performing sources could expect to 
achieve the floor in 99 of 100 future performance tests conducted under 
the same conditions as its performance test.. The commenter thus 
sharply mischaracterizes a 99% confidence level as the worst 
performance of a best performing source.: the level in fact assumes 
identical operating conditions as those of the performance test.
---------------------------------------------------------------------------

    \67\ Note, again, that the variability we quantify by these 
analyses is within-test condition variability only. We cannot 
quantify test-to-test variability and thus cannot quantify sources' 
total variability.
    \68\ See Volume III of the Technical Support Document, Section 
7.2 .
---------------------------------------------------------------------------

    EPA routinely establishes not-to-exceed standards (daily maximum 
values which cannot be exceeded in any compliance test) using the 99% 
confidence level. National Wildlife Federation v. EPA, 286 F. 3d 554, 
572 (D.C. Cir. 2002).\69\ At a confidence level of only 97% for 
example, the average of the best performing sources could expect to 
achieve the floor in only 97 of 100 future performance tests.
---------------------------------------------------------------------------

    \69\ The opinion notes further that percentiles for standards 
expressed as long-term average typically use a lower confidence 
level (usually 95 %c) due to the opportunity to lower the overall 
distribution with multiple measurements. 286 F. 3d at 573. The 
standards in this rule are necessarily daily maximum standards 
because continuous emissions monitors for HAP do not exist or have 
not been demonstrated on all types of Subpart EEE sources.
---------------------------------------------------------------------------

    We note that the choice of a confidence level is not a choice 
regarding the stringency of the emission standard. Although the 
numerical value of the floor increases with the confidence level 
selected it only appears to become less stringent. If EPA selected a 
lower confidence interval, we would necessarily adjust the standard 
downward due to the expectation that a source would not be expected to 
achieve the standard for uncontrollable reasons a larger per cent of 
the time. We would then have to account in some manner for this 
inability to achieve the standard. See Weyerhaeuser v. Costle, 590 F. 
2d 1011, 1056-57 (D.C. Cir. 1978) (also upholding standards established 
at 99 % confidence level). The governing issue is what level of 
confidence should the average of the best performing sources, and 
similarly designed and operated sources, have of passing the 
performance test demonstrating compliance with the standard. We believe 
that the 99% confidence level is a confidence level within the range of 
values we could have reasonably selected.\70\
---------------------------------------------------------------------------

    \70\ See also Chemical Mfrs. Ass'n v. EPA, 870 F. 2d at 229 
(99th percentile daily variability factor is reasonable); 227 (``the 
choice of statistical methods is committed to the sound discretion 
of the Administrator'').
---------------------------------------------------------------------------

    d. Considering Intersource Variability by Pooling Run-to-Run 
Variability is Appropriate. The commenter believes that any attempt by 
EPA to add a variability factor to adjust for intersource variability 
is unlawful and arbitrary and capricious. We see no statutory 
prohibition in considering intersource run-to-run variability of the 
best performing sources (which is all our floor calculation does, by 
considering the pooled run-to-run variability of the best performing 
sources). Section 112(d)(3) states that MACT floors are to reflect the 
``average emission limitation achieved'' but does not specify any 
single method of ascertaining an average. Considering the average run-
to-run variability among the group of best performing sources is well 
within the language of the provision (and was upheld in CMA, as noted 
above; see 870 F. 2d at 228). The commenter's further argument that 
`average' can only mean average of emission levels achieved in 
performance tests is inconsistent with the holding in Mossville, 370 F. 
3d at 1242, that EPA must account for variability in developing MACT 
floors and that individual performance tests do not by themselves 
account for such variability.
    We believe that it is reasonable and necessary to account for 
intersource variability of the best performing sources by taking the 
pooled average of the best performing sources' run-to-run variability. 
This is an aspect of identifying the average performance of those 
sources. Emissions data for each best performing source are random in 
nature, and this random nature is characterized by a stochastic 
distribution. The stochastic distribution is defined by its central 
tendency (average value) and the amount of dispersion from the point of 
central tendency (variance or standard deviation). Consequently, to 
define the performance of the average of the best performing sources, 
we must consider the average of the average emissions for the best 
performing sources as well as the pooled variance for those sources. 
Hence, we must consider intersource variability to identify the floor--
the average performance of the best performing sources.
    The commenter further states that EPA's attempt to adjust for 
intersource variability is unlawful, arbitrary, and capricious. EPA set 
floors at the 99th percentile worst emission level that it believed any 
source within the group of best performers could achieve, according to 
the commenter. The 99th percentile worst performance that could be 
expected from a source within the best performers is, simply put, not 
the average performance of the sources in that group, according to the 
commenter.
    The commenter misunderstands our approach to calculate the floor--
the floor is not the 99th percentile highest emission level that any 
best performing source could achieve. The floor for

[[Page 59439]]

existing sources is calculated as the 99th percentile modified upper 
prediction limit of the average of the best performing sources. It 
represents the average of the best performing sources' emissions levels 
plus the pooled within-test condition variance of the best performing 
sources. The floor for existing sources is not the highest 99th 
percentile upper prediction limit for any best performing source as the 
commenter states.
    e. Why isn't Total Variability Already Accounted for by Compliance 
Test Conditions?
    Comment: One commenter states that EPA's use of variability factors 
along with worst-case data is unlawful and arbitrary and capricious. 
EPA has stated that its use of worst case ``compliance'' data accounts 
for variability. EPA admits that compliance data reflect special worst 
case conditions created artificially for the purpose of obtaining 
lenient permit limits, according to the commenter. EPA provides no 
reason whatsoever to believe that a source would continue to operate 
under such conditions even one percent of the time. Thus, the commenter 
concludes, by applying a 99 percent variability factor to compliance 
test data, EPA ensures that the adjusted data do not accurately reflect 
the performance of any source. Accordingly, EPA's use of a variability 
factor is unlawful.
    The commenter also states that, to increase compliance data with 
the reality that sources will not be operating under the worst case 
conditions except during permit setting tests, the Agency's use of a 
variability factor with compliance data is arbitrary and capricious.
    Response: All but two standards in the final rule are based on 
compliance test data--when sources maximized operating parameters that 
affect emissions to reflect variability of those parameters and to 
achieve emissions at the upper end of the range of normal operations. 
Use of these data is appropriate both because they are data in EPA's 
possession for purposes of section 112(d)(3) and because these data 
help account for best performing sources' operating variability. CKRC, 
255 F. 3d at 867.
    The main thrust of the comment is that total variability is 
accounted for by the conditions of the performance test, so that making 
further adjustments to allow for additional variability is improper. 
The commenter believes that the floor should be calculated simply as 
the average emissions of the best performing sources and that this 
floor would encompass the range of operations of the average of the 
best performing sources. We disagree.
    The compliance test is designed to mirror the outer end of the 
controllable variability occurring in normal operations. These 
controllable factors include the amount of HAP fed to a source in 
hazardous waste, and controllable operating parameters on pollution 
control equipment (such as power input to ESPs, or pressure drop across 
wet scrubbers, factors which are reflected in the parametric operating 
limits written into the source's permit and which are based on the 
results of the compliance testing). However, this is plainly not all of 
the variability a source experiences. Other components of run-to-run 
variability, including variability relating to measuring (both stack 
measurements and measurements at analytic laboratories) are not 
reflected, for example. Nor is test-to-test variability reflected, 
notably the point in the maintenance cycle that testing is conducted 
and the variability associated with those inherently differing test 
conditions even though the source attempts to replicate the test 
conditions (e.g., measurement variability attributable to use of a 
different test crew and analytical laboratory and different weather 
conditions such as ambient temperature and moisture). Other changes 
that occur over time are due to a wide variety of factors related to 
process operation, fossil fuels, raw materials, air pollution control 
equipment operation and design, and weather. Sampling and analysis 
variations can also occur from test to test (above and beyond those 
accounted for when assessing within-test variability) due to 
differences in emissions testing equipment, sampling crews, weather, 
and analytical laboratories or laboratory technicians.
    Thus, there is some need for a standard to account for this 
additional variability, and not simply expect for a single performance 
test to account for it. The analyses in Sections 16 and 17 of Volume 
III of the Technical Support Document confirm these points.
    Moreover, the best performing sources (and the average of the best 
performers) must be able to replicate the compliance test if they are 
to be able to continue operating under their full range of normal 
operations. It is thus no answer to say that the best performing 
sources could operate under a more restricted set of conditions in 
subsequent performance tests and still demonstrate compliance, so that 
there is no need to assure that results of initial performance tests 
can be replicated. To do so would no longer allow the best performing 
sources (and thus the average of the best performing sources) to 
operate under their full range of normal operations, and thus 
impermissibly would fail to account for their total variability.
    As discussed throughout this preamble, emissions variability--run-
to-run and test-to-test variability--is real and must be accounted for 
if a best performing source is to be able to replicate the emissions 
achieved during the initial compliance test. We consequently conclude 
that we must account for variability in establishing floor levels, and 
that merely considering the average of compliance test data fails to do 
so. We have therefore quantified run-to-run variability using standard 
statistical methodologies, and accounted for test-to-test variability 
either by quantifying it (in the case of fabric filter particulate 
matter removal performance) or accounting for it qualitatively (in the 
case of the SRE/feed ranking methodology).
    Comment: The commenter notes that if EPA believes that single 
performance test results do not accurately capture source's 
variability, the solution is to gather more data, not to avoid using a 
straight emissions methodology. EPA cannot use this as an excuse for 
basing floor levels on a chosen technology rather than the performance 
of the best performing sources.
    Response: There is no obligation for EPA to gather more performance 
data, since the statute indicates that EPA is to base floor levels on 
performance of sources ``for which the Administrator has emissions 
information.'' Section 112(d)(3)(A); CKRC, 255 F. 3d at 867 (upholding 
EPA's decision to use the compliance test data in its possession in 
establishing MACT standards). Indeed, the already-tight statutory 
deadlines for issuing MACT standards would be even less feasible if EPA 
took further time in data gathering. EPA notes further that because 
particulate matter continuous emission monitors are not widely used, 
even further data gathering would be limited to snapshot, single 
performance test results, still leaving the problem of estimating 
variability from a limited data set.\71\ See also Sierra Club v. EPA, 
167 F. 3d at 662 (``EPA typically has wide latitude in determining the 
extent of data-gathering necessary to solve a problem'').
---------------------------------------------------------------------------

    \71\ Performance tests take an average of 5-8 days to conduct, 
and cost approximately from $200,000--$500,000 per test. The 
commenter's off-hand suggestion appears to have ignored these 
realities.
---------------------------------------------------------------------------

    Thus, EPA has no choice but to assess best performers and their 
level of performance on the basis of limited amounts of data per 
source. As explained in the previous response to

[[Page 59440]]

comments, EPA has selected a methodology that reasonably do so.
    EPA notes further that it has carefully examined those instances 
where there are multiple test conditions (usually compliance tests 
conducted at different times) for sources ranked as best performing. 
This analysis confirms EPA's engineering judgment that total 
variability is not fully encompassed in the single test condition 
results used to identify these sources as best performing, and that 
without taking this additional variability into account, best 
performing sources would be unable to achieve the floor standard 
reflecting their own performance in those single test conditions.\72\
---------------------------------------------------------------------------

    \72\ USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards,'', September 
2005, Sections 16 and 17.
---------------------------------------------------------------------------

2. Universal Variability Factor for Particulate Emissions Controlled 
with a Fabric Filter
    Comment: One commenter states that, in calculating the universal 
variability factor (UVF) to account for total variability--test-to-test 
variability and within-test variability--for sources controlling 
particulate matter with a fabric filter, it appears that EPA considered 
the variability of sources that are not best performing sources. If so, 
EPA has contravened the law.
    The commenter also states that EPA's attempt to use a variability 
factor derived from an analysis of variability of multiple sources is 
unlawful. If EPA considers variability at all, it must consider the 
relevant source's variability.
    Response: We developed the particulate matter UVF for sources 
equipped with a fabric filter using data from best performing sources 
only.\73\
---------------------------------------------------------------------------

    \73\ USEPA, ``Draft Technical Support Document for HWC MACT 
Standards, Volume III: Selection of MACT Standards,'', March 2004, 
p. 5-4.
---------------------------------------------------------------------------

    It is reasonable to aggregate particulate matter emissions data 
across source categories for all best performing sources equipped with 
a fabric filter because the relationship between standard deviation and 
emissions of particulate matter is not expected to be impacted by the 
source category type.\74\ Rather, particulate emissions from fabric 
filters are a function of seepage (i.e., migration of particles through 
the filter cake) and leakage (i.e., particles leaking through pores, 
channels, or pinholes formed as the filter cake builds up). The effect 
of seepage and leakage on emissions variability should not vary across 
source categories.\75\ Put another way, fabric filter particulate 
matter reduction is relatively independent of inlet loadings to the 
fabric filter. 69 FR 21233. This is confirmed by the fact that there 
are no operating parameters that can be readily changed to increase 
emissions from fabric filters, id., so control efficiencies reflected 
in test conditions from different source types will still accurately 
reflect fabric filter control efficiency.
---------------------------------------------------------------------------

    \74\ In addition, emissions are not generally affected by 
particulate inlet loading.
    \75\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' September 
2005, Section 5.3.
---------------------------------------------------------------------------

3. Test-to-Test Variability
    Comment: Several commenters state that EPA seems to have ignored 
test-to-test variability resulting from changes that occur over time 
such as: normal and natural changes in a wide variety of factors 
related to process operation, fuels, raw materials, air pollution 
control equipment operation and design, and differences in emissions 
testing equipment, sampling crews, weather, analytical laboratories or 
laboratory technicians. All these sources of variation are expected in 
that they are typical and are not aberrations. In addition, there are 
unexpected sources of variability that occur in real-world operations, 
which also must be accommodated according to commenters.
    Commenters state that using compliance test data and assessing 
within-test condition variability (i.e., run variance) do not fully 
account for test-to-test variability and thus understates total 
variability. Consequently, the average of the best performing sources 
may not be able to achieve the same emission level under a MACT 
performance test when attempting to operate under the same conditions 
as it did during the compliance test EPA used to establish the floor. 
Even though sources generally operated at the extreme high end of the 
range of normal operations during the compliance tests EPA uses to 
establish the standards, the average of the best performing sources 
would need to operate under those same compliance test conditions to 
establish the same operating envelope--the operating envelope needed to 
ensure the source can operate under the full range of normal emissions.
    Response: We agree with commenters that we have not quantified 
test-to-test variability when establishing the floors for standards 
other than particulate matter where a best performing source uses a 
fabric filter. We are able to quantify only within-test variability 
(i.e., run-to-run variability) for the other floors, which is only one 
component of total variability. This is one reason we use the SRE/Feed 
approach wherever possible rather than a straight emissions approach to 
rank the best performing sources to calculate the floor--the SRE/Feed 
ranking approach derives floors that better estimate the levels of best 
performing sources' performance. See also discussion in Part Four, 
Section III.A, and the discussion below documenting that test-to-test 
variability can be substantial.
    Comment: One commenter states that EPA should use the universal 
variability factor (UVF) that accounts for total variability for 
particulate matter controlled with a fabric filter to derive a 
correction factor to account for the missing test-to-test variability 
component of variability for semivolatile metals and low volatile 
metals. The commenter then suggests that the within-test variability 
for semivolatile and low volatile metals be adjusted upward by the 
correction factor to correct for the missing test-to-test variability 
component.
    The commenter focused on cement kilns and compared the total 
variability imputed from the UVF for the three cement kiln facilities 
used to establish the UVF to the within-test variability (i.e., run 
variance) for each facility. The commenter determined that, on average 
for the three facilities, total variability was a factor of 4.2 higher 
than within-test variability. Because semivolatile and low volatile 
metals are also controlled with a fabric filter, the commenter 
suggested that the total variability of particulate matter could be 
used as an estimate of the total variability for semivolatile and low 
volatile metals. Thus, the commenter suggested that the within-test 
condition variability for semivolatile and low volatile metals be 
increased by a factor of 4.2 to account for total variability when 
calculating floors.
    Response: As stated throughout this preamble, we believe that there 
is variability in addition to within-test condition (i.e., run-to-run) 
variability that we cannot quantify--that we refer to as test-to-test 
variability. We also do not believe this test-to-test variability is 
captured by compliance test operating conditions as discussed above, 
and thus establishing the floor using emissions data representing the 
extreme high end of the range of normal emissions does not account for 
test-to-test variability. We disagree, however, with the commenter's 
attempts to quantify the remaining test-to-test variability for floors 
other than particulate matter

[[Page 59441]]

where all best performing sources are equipped with fabric filters.
    We generally agree with the commenter's approach for extracting the 
test-to-test component of variability using the UVF curve for 
particulate matter controlled with a fabric filter.\76\ The commenter 
has documented that for cement kilns, test-to-test variability of 
particulate emissions controlled with a fabric filter is on average a 
factor of 4.2 higher than within-test variability.
---------------------------------------------------------------------------

    \76\ We note, however, that an argument could be made for using 
a source or condition-specific correction factor rather than 
averaging the correction factors for all sources within a source 
category.
---------------------------------------------------------------------------

    We believe the commenter's suggestion to adopt this correction 
factor to semivolatile and low volatile metals is technically flawed 
and for several reasons would present statistical difficulties. First, 
total variability for semivolatile metals and low volatile metals 
controlled with a fabric filter can be different from the total 
variability of particulate matter controlled with a fabric filter 
because: (1) The test methods are different (i.e., Method 5 for 
particulate matter and Method 29 for metals) and thus sample extraction 
and analysis methods differ; (2) the factors that affect partitioning 
of particulate matter to combustion gas (i.e., entrainment) are 
different from the factors that affect semivolatile metal partitioning 
to the combustion gas (i.e., metal volatility); and (3) the volatility 
of semivolatile metals is affected by chlorine feedrates.
    Second, adopting a variability factor applicable to fabric filters 
for use on electrostatic precipitators \77\ is problematic because both 
test-to-test and within-test variability of these emission control 
devices can be vastly different. Factors that affect emissions 
variability for sources equipped with a fabric filter include: (1) Bag 
wear and tear due to thermal degradation and chemical attack; and (2) 
variability in flue gas flowrate. Factors that affect emissions 
variability for sources equipped with an electrostatic precipitator are 
different (see discussion in Section III.B above) and include: 
variations in particle loading and particle size distribution, erosion 
of collection plates, and variation in fly ash resistivity due to 
changes atmospheric moisture and in sulfur feedrate (e.g. different 
type of coal).
---------------------------------------------------------------------------

    \77\ We infer that the commenter suggests that we use this 
correction factor for semivolatile and low volatile metals 
controlled by both electrostatic precipitators and fabric filters 
since the majority of cement kilns are equipped with electrostatic 
precipitators.
---------------------------------------------------------------------------

    Finally, the approach raises several difficult statistical 
questions including: (1) What is the appropriate number of runs to use 
to identify the degrees of freedom and the t-statistic in the floor 
calculations (e.g., should we use the number of runs available for 
metals emissions for the source or the number of runs available for 
particulate matter emissions from which the correction factor is 
derived); and (2) should we use a generic correction factor for all 
source categories or calculate source category-specific or source-
specific correction factors.
    For these reasons, we believe the approach we use for quantifying 
baghouse particulate matter collection variability is not readily 
transferable to other types of control devices and other HAP. We 
therefore are not applying a quantified correction factor in the final 
rule but rather are using a MACT ranking methodology that qualitatively 
accounts for total emission variability, notably test-to-test 
variability.

B. SRE/Feed Methdology

1. Description of the Methodology
    As proposed, we are using the System Removal Efficiency (SRE)/Feed 
approach to determine the pool of best performing sources for those HAP 
whose emissions can be controlled in part by controlling the hazardous 
waste feed of the HAP--that is, controlling the amount of HAP in the 
hazardous waste fed to the source. These are HAP metals and chlorine. 
Our basic approach is to determine the sources in our database with the 
lowest hazardous waste feedrate of the HAP in question (semi-volatile 
metals, low volatile metals, mercury, or chlorine), and the sources 
with the best system removal efficiency for the same HAP. The system 
removal efficiency is a measure of the percentage of HAP that is 
removed prior to being emitted relative to the amount fed to the unit 
from all inputs (hazardous waste, fossil fuels, raw materials, and any 
other input). The pool of best performing sources are those with the 
best combination of hazardous waste feedrate and system removal 
efficiency as determined by our ranking procedure, separate best 
performer pools being determined for each HAP in question (SVM, LVM, 
mercury, and chlorine), reflecting the variability inherent in each of 
these ranking factors (see A.2.a.(1) above). We then use the emission 
levels from these sources to calculate the emission level achieved by 
the average of the best performing sources, as also explained in the 
previous section. This is the MACT floor for the HAP from the source 
type. For new sources, we use the same methodology but select the 
emission level (adjusted statistically to account for quantifiable 
variability) of the source with the best combined ranking. A more 
detailed description of the methodology is found in Volume III of the 
Technical Support Document, section 7.3.
    This methodology provides a reasonable estimate of the best 
performing sources and their level of performance for HAP susceptible 
to hazardous waste feed control. As required by section 112(d)(2), EPA 
has considered measures that reduce the volume of emissions through 
process changes, or that prevent pollutant release through capture at 
the stack, and assessed how these control measures are used in 
combination. Section 112(d)(2)(A), (C) and (E). Hazardous waste feed 
control is clearly a process change that reduces HAP emissions; air 
pollution control systems collect pollutants at the stack. These are 
the best systems and measures for controlling HAP emissions from 
hazardous waste combustors. 69 FR at 21226. In considering these 
factors, EPA has necessarily considered such factors as design of 
different air pollution control devices, waste composition, pollution 
control operator training and behavior, and use of pollution control 
devices and methodologies in combination. CKRC, 255 F. 3d at 864-65 
(noting these as factors, in addition to a particular type of air 
pollution control device, that can influence pollution control 
performance); 69 FR at 21223 n. 47 (system removal efficiency measures 
all internal control mechanisms as well as back-end emission control 
device performance).
    EPA also believes that this methodology reasonably estimates the 
best performing sources' level of performance by accounting for these 
sources' total variability, including their performance over time. The 
methodology quantifies run-to-run variability. See 69 FR at 21232-33. 
It does not quantify test-to-test variability because we are unable to 
do so for these pollutants. (See sections A. 2.a.(2) and 3 above.) 
Although all variability must be accounted for when calculating floors, 
the only definitive way to accurately quantify this test-to-test 
emissions variability is through evaluation of long-term continuous 
emissions monitoring data, which do not presently exist. We believe, 
however, that SRE/Feed methodology provides some margin for estimating 
this additional, non-quantifiable variability. This is illustrated in 
the technical support document (volume III section 17), which clearly 
shows that the straight emissions approach underestimates (indeed, 
fails to account

[[Page 59442]]

for) lower emitting sources' long-term emissions variability. These 
lower emitting sources that would otherwise not meet the floor levels 
on individual days under the straight emission approach would be able 
(or otherwise are more capable) to do so under the SRE/feed approach.
    EPA further believes that the SRE/Feed methodology appropriately 
accounts for design variability that exists across sources for 
categories, like those here, which consist of a diverse and 
heterogeneous mixture of sources. This is especially true of 
incinerators and boilers, for which there are smaller on-site units 
that are located at widely varying industrial sectors that essentially 
combust single, or multiple wastestreams that are specific to their 
industrial process, and off-site commercial units dealing with many 
different wastes of different origins and HAP metal and chlorine 
composition. EPA believes that these variations are best encompassed in 
the SRE/Feed approach, rather than with a subcategorization scheme that 
could result in anomalous floor levels because there are fewer sources 
in each source subcategory from which to assess relative 
performance.\78\ See Mossville, 370 F. 3d at 1240 (upholding floor 
methodology involving reasonable estimation, rather than use of 
emissions data, when sources in the category have heterogeneous 
emission characteristics due to highly variable HAP concentrations in 
feedstocks).
---------------------------------------------------------------------------

    \78\ At proposal, we conducted a technical analysis to determine 
potential subcategorization options. We then conducted an analysis 
to determine if these different types of sources exhibited 
statistically different emissions. Although EPA in the end 
determined that these source categories should not be subcategorized 
further, this decision was based in part because the SRE/Feed 
methodology better accounts for the range of emissions from the best 
performing sources for these diverse combustion types. See USEPA, 
``Technical Support Document for the HWC MACT Standards, Volume III: 
Selection of MACT Standards,'' September 2005, Section 4, for an 
explanation of the subcategorization assessment, which includes 
examples of anomalous floor results for certain subcategorization 
approaches.
---------------------------------------------------------------------------

    Use of the SRE/Feed approach also avoids basing the floor standards 
on a combination of the lowest emitting low feeding sources and the 
lowest emitting high feeding sources. For example, the five lowest 
emitting incinerators for semivolatile metals that would comprise the 
MACT pool using a straight emissions methodology include three sources 
that are the first, second, and fourth lowest feeding sources among all 
the incinerators.\79\ The other two best performing incinerators have 
the first and second best system removal efficiencies (and the highest 
two metal feedrates). It is noteworthy that the highest feed control 
level among these best performing sources is over three orders of 
magnitude higher than the feed control level of the lowest feeding best 
performing source.\80\ Establishing limits dominated by both superior 
feed control sources and back-end controlled sources would result in 
floor levels that are not reflective of the range of emissions 
exhibited by either low feeding sources or high feeding sources and 
would more resemble new source standards for both of these different 
types of combustors. Such floors could lead to situations, for example, 
where commercial sources could find it impracticable to achieve the 
standards without reducing the overall scope of their operations (since 
the standard could operate as a direct constraint on the amount of 
hazardous waste that could be fed to the device, in effect depriving a 
combustion source of its raw material). Similarly, low feeding sources 
that cannot achieve this floor level may be required to add expensive 
back-end control equipment that would result in minimal emission 
reductions, likely forcing the smaller on-site source to cease 
hazardous waste treatment operations and to instead send the waste to a 
commercial treatment unit.
---------------------------------------------------------------------------

    \79\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' September 
2005, Appendix C, Table ``E--INC--SVMCT'' and, to determine relative 
feed control and SRE rankings for these sources, Appendix E Table 
``SF--INC--SVMCT''.
    \80\ Source 340 had a semivolatile metal feed control MTEC of 
892 [mu]g/dscm, whereas source 327 had a semivolatile metal feed 
control MTEC of 3,080,571 [mu]g/dscm.
---------------------------------------------------------------------------

    The inappropriateness of a straight emissions-based approach for 
feed controlled pollutants for commercial hazardous waste combustors is 
further highlighted by the fact that several commercial hazardous waste 
combustors that are achieving the design level of the particulate 
matter standard are not achieving the semivolatile and/or low volatile 
metals straight emissions based design level, and, in some instances, 
floor level.\81\ This provides further evidence that low feeding 
sources are in fact biasing some of the straight emissions-based floors 
to the extent that even the sources with the most efficient back-end 
control devices would be incapable of achieving the emission standards 
calculated on a straight emission basis.
---------------------------------------------------------------------------

    \81\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' September 
2005, Section 17.4
---------------------------------------------------------------------------

    These results are inconsistent with the intent of the section 112 
(d) (see 2 Legislative History at 3352 (House Report) stating that MACT 
is not intended to drive sources out of business). Standards that could 
force commercial sources to reduce the overall scope of their 
operations are also inconsistent with requirements and objectives of 
the Resource Conservation and Recovery Act to require treatment of 
hazardous wastes before the wastes can be land disposed, and to 
encourage hazardous waste treatment. RCRA sections 3004 (d), (e), (g) 
and 1003 (a) (6); see also section 112 (n) (7) of the CAA, stating that 
section 112 (d) MACT standards are to be consistent with RCRA subtitle 
C emission standards for the same sources to the maximum extent 
practicable (consistent with the requirements of section 112 (d)); 
moreover, EPA doubts that a standard which precludes effective 
treatment mandated by a sister environmental statute must be viewed as 
a type of best performance under section 112 (d). The SRE/Feed 
methodology avoids this result by always considering hazardous waste 
feed control in combination with system removal efficiency and 
according equal weight to both means of control in the ranking process.
    It is also important to emphasize what the SRE/Feed methodology 
does not evaluate: Feed control of HAP in fossil fuel or raw material 
inputs to these devices. Emission reduction of these HAP are 
controllable by back-end pollution control devices which remove a given 
percentage of pollutants irrespective of their origin and is assured by 
the system removal efficiency portion of the methodology, as well as 
through the particulate matter standard (see section IV.A below). Feed 
control of these inputs is not a feasible means of control, however. 
HAP content in raw materials and fossil fuel can be highly variable, 
and so cannot even be replicated by a single source. Raw material and 
fossil fuel sources are also normally proprietary, so other sources 
would not have access to raw material and fossil fuel available (in its 
performance test) to a source with low HAP fossil fuel and raw material 
inputs. Such sources would thus be unable to duplicate these results. 
Moreover, there are no commercial-scale pretreatment processes 
available for removing or reducing HAP content in raw materials or 
fossil fuels to these units. See technical support document volume III 
section 17.5 and 25; see also 69 FR at 21224 and n. 48.
2. Why Aren't the Lowest Emitters the Best Performers?
    Some commenters nonetheless argue that best performing sources can 
only mean sources with the lowest HAP

[[Page 59443]]

emissions, and that the SRE/Feed methodology is therefore flawed 
because it does not invariably select lowest emitters as best 
performers.\82\ The statute does not compel this result. There is no 
language stating that lowest emitting sources are by definition the 
best performers. The floor for existing sources is to be based on the 
average emission limitation achieved by the ``best performing'' 12 per 
cent of sources. Section 112(d)(3)(A). This language does not specify 
how ``best performing'' is to be determined: by means of emission 
level, emission control efficiency, measured over what period of time, 
etc. See Sierra Club v. EPA, 167 F. 3d at 661 (language of floor 
requirement for existing sources ``on its own says nothing about how 
the performance of the best units is to be calculated''). Put another 
way, this language does not answer the question of which source is the 
better performing: one that emits 100 units of HAP but also feeds 100 
units of that HAP, or one that emits 101 units of the HAP but feeds 
10,000 units. See 69 FR at 21223. Moreover, new source floors are to be 
based on the performance of the ``best controlled'' similar source 
achieved in practice. Section 112(d)(3). ``Best controlled'' can 
naturally be read to refer to some means of control such as system 
removal efficiency as well as to emission level.
---------------------------------------------------------------------------

    \82\ In fact, many of the sources identified as best performing 
under the SRE/Feed methodology are also the lowest emitting, 
although this is not invariably the case.
---------------------------------------------------------------------------

    Use of a straight emissions approach to identify floor levels can 
lead to arbitrary results. Most important, as explained above, it leads 
to standards which cannot be achieved consistently even by the best 
performing sources because operating variability is not accounted for. 
This is shown in section 17 of volume III of the technical support 
document. These analyses show that (a) emissions from these sources do 
in fact vary from test-to-test, and that no two snapshot emission test 
results are identical; (b) our statistical approach that quantifies 
within test, run-to-run variability underestimates the best performing 
sources' long term, test-to-test variability; \83\ (c) best performing 
sources under the straight emissions approach advocated by the 
commenter (i.e. the lowest emitting sources) had other test conditions 
that did not achieve straight emission floor levels; (d) best 
performing sources under the straight emissions approach are projected, 
based on two separate analyses using reasonable assumptions, not to 
achieve the straight emissions floor standard based on these sources' 
demonstrated variations in system removal efficiencies over time (i.e., 
from test-to-test); and (e) SRE/feed methodology yields floor levels 
(i.e. the floor standards in the rule) that better estimate the 
emission levels reflecting the performance over time of the best 
performing sources. See Mossville, 370 F. 3d at 1242 (floor standard is 
reasonable because it accommodated best performing source's highest 
level of performance (i.e. its total variability), even though the 
level of the standard was higher than any individual measurement from 
that source).
---------------------------------------------------------------------------

    \83\ Best performing sources pursuant to the straight emissions 
methodology are projected to be unable to achieve the levl of their 
of their performance test emissions even after they are adjusted 
upward to account for run-to-run variability.
---------------------------------------------------------------------------

    As noted earlier, the straight emissions methodology can also limit 
operation of commercial units because the standard reflects a level of 
hazardous waste feed control which could force commercial units to burn 
less hazardous waste because such standards more resemble new source 
standards. The straight emissions methodology also arbitrarily reflects 
HAP levels in raw materials and fossil fuels, an infeasible means of 
control for any source.
    Another arbitrary, and indeed impermissible, result of the straight 
emissions methodology is that in some instances (noted in responses 
below) the methodology results in standards which would force sources 
identified as best performing to install upgraded air pollution control 
equipment. This result undermines section 112 (d) (2) of the statute, 
by imposing what amounts to a beyond the floor standard without 
consideration of the beyond the floor factors: the cost of achieving 
those reductions, as well as energy and nonair environmental impacts.
    Comment: The commenter states that because MACT floors must reflect 
the ``actual performance'' of the relevant best performing hazardous 
waste combusters, this means that the lowest emitters must be the best 
performers. The commenter cites CKRC v. EPA, 255 F. 3d at 862 and other 
cases in support.
    Response: As explained in the introduction above, the statute does 
not specify that lowest emitters are invariably best performers. Nor 
does the caselaw cited by the commenter support this position. The D.C. 
Circuit has held repeatedly that EPA may determine which sources are 
best performing and may ``reasonably estimate'' the performance of the 
top 12 percent of these sources by means other than use of actual data. 
Mossville, 370 F. 3d at 1240-41 (collecting cases). In Mossville, 
sources had varying levels of vinyl chloride emissions due to varying 
concentrations of vinyl chloride in their feedstock. Individual 
measurements consequently did not adequately represent these sources' 
performance over time. Not-to-exceed permit limits thus reasonably 
estimated sources' performance, corroboration being that individual 
sources with the lowest long-term average performance occasionally came 
close to exceeding those permit limits. Id. at 1241-42. The facts are 
similar here, since our examination of best performing sources with 
multiple test conditions likewise shows instances where these sources 
would be unable to meet floors established based solely on lowest 
emissions (including their own). As here, EPA was not compelled to base 
the floor levels on the lowest measured emission levels.
    Comment: The same commenter maintains that it is clear from the 
caselaw that MACT floors must reflect the relevant best performing 
sources' ``actual performance'', and that this must refer to the 
emissions level it achieves.
    Response: As just stated, the D.C. Circuit has repeatedly stated 
that EPA may make reasonable estimates of sources' performance in 
assessing both which sources are best performing and the level of their 
performance. The court has further indicated that EPA is to account for 
variability in assessing sources' performance for purposes of 
establishing floors, and this assessment may require that EPA make 
reasonable estimates of performance of best performing sources. CKRC, 
255 F. 3d at 865-66; Mossville, 370 F. 3d at 1241-42. See discussion in 
A.1.a above.
    Comment: The commenter generally maintains that EPA's floor 
approaches consider only the performance of back-end pollution control 
technology and so fail to capture other means of HAP emission control 
that otherwise would be captured if EPA were to assess performance 
based on the emission levels each source achieved.
    Response: EPA agrees that factors other than end-of-stack pollution 
control can affect metal HAP and chlorine emissions. This is why EPA 
assesses performance for these HAP by considering combinations of 
system removal efficiency (which measures every element in a control 
system resulting in HAP reduction, not limited to efficiency of a 
control device), and hazardous waste HAP feed control. Standards for 
dioxins and other organic HAP (which have no hazardous waste feed 
control component) likewise assess every element of control.

[[Page 59444]]

    EPA also accounts for the variability of HAP levels in the 
(essential) use of raw materials and fossil fuels by assessing 
performance of back-end control but not evaluating fuel/raw material 
substitution, which, as discussed later in the response to comments 
section, are infeasible means of control. Mossville, 370 F. 3d at 1241-
42, is instructive on this point. The court held that the constant 
change in raw materials justified EPA's use of a regulatory limit to 
estimate a floor level. The reasonableness of this level was confirmed 
by showing that the highest individual data point of a best performing 
source was nearly at the level of the regulatory limit. Under the 
commenter's approach, the court would have had no choice but to hold 
that the level the source achieved in a single test result using 
`clean' raw materials--i.e. the `level achieved' in the commenter's 
language--dictated the floor level.
    See part four, section III.C for EPA's response to this comment as 
it relates to the methodologies for the particulate matter standard and 
total chlorine standard for hydrochloric acid production furnaces.
    Comment: The commenter notes that the SRE/Feed methodology does not 
account for all HAP emissions, failing to account for metal and 
chlorine feedrates in raw materials and fossil fuels.
    Response: The methodology does not assess the effect of feed 
``control'' of HAP levels in raw materials or fossil fuels which may be 
inputs to the combustion units. This is because such control may not be 
replicable by an individual source, or duplicable by any other source. 
See 69 FR at 21224 and n. 48; Sierra Club v. EPA, 353 F. 3d 976, 988 
(``substitution of cleaner ore stocks was not * * * a feasible basis on 
which to set emission standards. Metallic impurity levels are variable 
and unpredictable both from mine to mine and within specific ore 
deposits, thereby precluding ore-switching as a predictable and 
consistent control strategy'').\84\ EPA's methodology does account for 
HAP control of all inputs by assessing system removal efficiency, which 
measures reductions of HAPs in all inputs (including fossil fuel and 
raw materials) to a hazardous waste combustion unit. Further, 
nonmercury metal HAP emissions attributable to raw materials and fossil 
fuels are effectively controlled with the particulate matter standard, 
a standard that is based on the sources with best back-end control 
devices. The only element which is not controlled is what cannot be: 
HAP levels in feeds for which fuel or raw material switching is simply 
not an available option.
---------------------------------------------------------------------------

    \84\ Although this language arose in the context of a potential 
beyond-the-floor standard, EPA believes that the principle stated is 
generally applicable. MACT standards, after all, are technology-
based, and if there is no technology (i.e. no avaialble means) to 
achieve a standard--i.e. for a soruce to achieve a standard whenever 
it is tested (as the rules require)--then the standard is not an 
achieveable one.
---------------------------------------------------------------------------

    Comment: The commenter further maintains, however, that the means 
by which sources may be achieving levels of performance are legally 
irrelevant (citing National Lime Ass'n v. EPA, 233 F. 3d 625 , 634 and 
640 (D.C. Cir. 2000)). The fact that sources with ``cleaner'' raw 
material and fossil fuel inputs may not intend to have resulting lower 
HAP emissions is therefore without legal bearing.
    Response: The issue here is not one of intent. The Court, in 
National Lime, rejected the argument that sources' lack of intent to 
control a HAP did not preclude EPA from establishing a section 112(d) 
standard for that HAP. See 233 F. 3d at 640, rejecting the argument 
that HAP metal control achieved by use of back-end control devices 
(baghouses) could not be assessed by EPA because the sources used the 
back-end control devices to control emissions of particulate matter. 
The case did not consider the facts present here, where the issue is 
not a source's intent, but rather a means of control which involves 
happenstance (composition of HAP in raw materials and fossil fuel used 
the day the test was conducted) and so is neither replicable nor 
duplicable.
    National Lime also held that EPA must establish a section 112(d) 
emission standard for every HAP emitted by a major source. 233 F. 3d at 
634. EPA is establishing emission standards for all HAP emitted by 
these sources. In establishing these standards, EPA is not evaluating 
emission reductions attributable to the type of fossil fuel and raw 
material used in the performance tests, because this is not a 
``feasible basis on which to set emission standards.'' Sierra Club, 353 
F. 3d at 988.
    EPA thus does not agree with this comment because the issue is not 
a source's intent but rather whether or not to assess emission 
reductions from individual test results which reflect an infeasible 
means of control.
    Comment: The commenter maintains, however, that even if individual 
sources (including those in the pool of best performing sources) cannot 
reduce HAP concentrations in raw materials and fossil fuels, they may 
achieve the same reductions by adding back-end pollution control. 
Nothing in section 112(d)(3) says that sources have to use the means of 
achieving a level of performance that other best performing sources 
used.
    Response: The thrust of this comment is essentially to 
impermissibly bypass the beyond-the-floor factors set out in section 
112(d)(2) under the guise of adopting a floor standard. Suppose that 
EPA were to adopt a floor standard dominated by emission levels 
reflecting HAP concentrations present in a few sources' raw materials 
and fossil fuels during their test conditions. Suppose further that 
some sources have to upgrade their back-end control equipment to 
operate at efficiencies better than the average level demonstrated by 
the best performing sources, because test results based on fossil fuel 
and raw material levels are neither replicable nor duplicable. In this 
situation, EPA believes that it would have improperly adopted a beyond-
the-floor standard because EPA would have failed to consider the 
beyond-the-floor factors (cost, energy, and nonair environmental 
impacts) set out in section 112(d)(2).\85\
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    \85\ Analysis of the levels of HAP in raw matrial and 
nonhazardous waste fuels suggests that this is a realistic outcome. 
Our analysis shows that emissions attributable to raw material and 
fossil fuel can be significant relative to the level of the straight 
emissions-based floor design level and floor (the methodology 
advocated by the commenter), and therefore could inappropriately 
impact a sournce's ability to comply with such a floor standard. See 
USEPA, ``Technical Support Document for the HWC MACT Standards, 
Volume III: Selection of MACT Standards,'' September 2005, Section 
17.6.
---------------------------------------------------------------------------

    Comment: EPA has not substantiated its claim that sources cannot 
switch fossil fuels or raw materials.
    Response: At proposal we evaluated fuel switching and raw material 
substitution as beyond-the-floor technologies for cement kilns and 
lightweight aggregate kilns and stated these technologies would not be 
cost effective.\86\ We also discussed why fuel switching is not an 
appropriate floor control technology for solid fuel-fired boilers. 69 
FR at 21273. Upon further evaluation, we again conclude that fuel 
switching and raw material substitution are not floor control 
technologies and are not cost effective beyond-the-floor technologies 
for cement kilns, lightweight aggregate kilns, and solid fuel-fired 
boilers.\87\
---------------------------------------------------------------------------

    \86\ See, for example, 69 FR at 21252, where we discuss the use 
of fuel-switching or raw material substitution as a possible beyond-
the-floor control for mercury at cement kilns.
    \87\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards, September 2005, 
Sections 11 and 25, for further discussion.
---------------------------------------------------------------------------

    Comment: EPA has failed to document the basis for its SRE ranking.

[[Page 59445]]

Specifically, EPA has not stated how it measured sources' SREs, or how 
it knows those rankings are accurate.
    Response: System removal efficiency is a parameter that is included 
in our database that is calculated by the following formula:
[GRAPHIC] [TIFF OMITTED] TR12OC05.000

    The HAP feedrate and emission data are components of the database 
that were extracted from emission test reports for each source. We use 
system removal efficiency for each relevant pollutant or pollutant 
group (e.g., semivolatile metals, low volatile metals, mercury, total 
chlorine) whenever the data allows us to calculate a reliable system 
removal efficiency. For example, we generally do not use system removal 
efficiencies that are based on normal emissions data because of the 
concern that normal feed data are too sensitive to sampling and 
measurement error. See 69 FR at 21224.\88\
---------------------------------------------------------------------------

    \88\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume II: Database,'' September 2005, Section 2, for 
further discussion on system removal efficiencies, which includes 
sample calculations and references to the database that contain the 
calculated system removal efficiencies for each source and each HAP 
or HAP group.
---------------------------------------------------------------------------

    The system removal efficiencies used in our ranking process are 
reliable and accurate because the feed and emissions data originate 
from compliance tests that demonstrate compliance with existing 
emission standards (primarily RCRA requirements). As such, the data are 
considered to have excellent accuracy and quality. RCRA trial burn and 
certification of compliance reports are typically reviewed in detail by 
the permitting authority. The compliance tests and test reports 
generally contain the use of various quality assurance procedures, 
including laboratory, method, and field blanks, spikes, and surrogate 
samples, all of which are designed to minimize sampling and analytical 
inaccuracies. EPA also noticed the data base for this rule for multiple 
rounds of comment and has made numerous changes in response to comment 
to assure accuracy of the underlying data. Thus, EPA concludes the 
calculated system removal efficiencies used in the ranking process are 
both reliable and accurate.
    Comment: EPA's approach with regard to use of stack data is 
internally contradictory. EPA uses stack data in establishing floors, 
but does not use stack data to determine which performers are best. EPA 
has failed to explain this contradiction.
    Response: Emission levels are used to calculate system removal 
efficiencies in order to assess each source's relative back-end control 
efficiency. Also, as explained in the introduction to this comment 
response section, the SRE/Feed methodology uses the stack emission 
levels of the sources using the best combinations of hazardous waste 
feed control and system-wide air pollution control (expressed as HAP 
percent removal over the entire system) to calculate the floors. The 
data are adjusted statistically to account for quantifiable forms of 
variability (run-to-run variability). This methodology reasonably 
selects best performing sources (for HAP amenable to these means of 
control), and reasonably estimates these sources' performance over 
time. As further stated in section B.2 above, using a straight 
emissions approach to identify best performers and their level of 
performance can lead to standards for these HAP that do not fully 
account for variability (including variability resulting from varying 
and/or uncontrollable amounts of HAP in raw materials and fossil fuels) 
and could force installation of de facto beyond-the-floor controls 
without consideration of the section 112(d)(2) beyond-the-floor 
factors.
    EPA thus does not see the contradiction expressed by the commenter. 
Use of the straight emissions approach as advocated by the commenter 
would lead to standards that do not reasonably estimate sources' 
performance and which could not be achieved even by the best performers 
with individual test conditions below the average of the 12 percent of 
best performing sources. These problems would be compounded many-fold 
if the data were not normalized and adjusted to at least account for 
quantifiable variability, steps the commenter also opposes. EPA's use 
of emissions data (suitably adjusted) after identifying best performers 
through the ranking methodology avoids these problems and reasonably 
estimates best performers' level of performance.
    Comment: The commenter rejects EPA's finding (69 FR at 21226) that 
individual test results in the data base do not fully express the best 
performing sources' performance. The commenter gives a number of 
reasons for its criticisms, which we answer in the following sequence 
of comments listed a though f.
    a. Comment: The commenter states that EPA claims emission levels do 
not fully reflect variability in part because they are sometimes based 
on tests where the source was feeding low levels of HAP during the 
test. The commenter claims this is inconsistent with the fact that EPA 
preferentially uses worst-case emissions obtained from tests where the 
sources spiked their feedstreams with metals, and that the mere 
possibility that these emissions do not reflect test data from 
conditions where variability was not maximized does not mean those data 
fail to represent a source's actual performance. The commenter also 
states that ``EPA's apparent suggestion that the best performing 
sources could not replicate the average performance of the sources with 
the lowest emissions is unsubstantiated and unexplained. Assuming that 
EPA accurately assesses a source's actual performance, the source can 
replicate that performance.''
    Response: HAPs in raw materials and fossil fuels contribute to a 
source's emissions. EPA has concerns that a straight emissions approach 
to setting floors may not be replicable by the best performing sources 
nor duplicable by other non-best performing sources because of varying 
concentration levels of HAP in raw material and nonhazardous waste 
fuels. The best performing sources operated under compliance test 
conditions as the commenter suggests. However, raw material and 
nonhazardous fuel HAP concentrations for the best performing sources 
will change over time, perhaps due to a different source of fuel or raw 
material quarry location, which could affect their ability to achieve 
the floor level that was based on emissions obtained while processing 
different fossil fuel or raw materials. EPA takes sharp issue with the 
commenter's statement that a single performance test result is 
automatically replicable so long as it is measured properly in the 
first instance. This statement is incorrect even disregarding HAP 
contributions in raw materials and fossil fuels since, as noted 
previously in section A.2.e, there are many other sources of 
variability

[[Page 59446]]

which will influence sources' performance over time (i.e., in 
subsequent performance tests).
    A straight emissions approach for establishing semivolatile and low 
volatile metal floors may result in instances where the best performing 
sources would not be capable of achieving the standards if their raw 
material and nonhazardous waste fuel HAP levels change over time. For 
each cement kiln and lightweight aggregate kiln, we estimated the 
emissions attributable to these raw materials and fossil fuels assuming 
each source was operating with hazardous waste HAP feed and back-end 
control levels equivalent to the average of the best performing sources 
(the difference in emissions across sources only being the result of 
the differing HAP levels in the nonhazardous waste feeds). The analysis 
shows that emissions attributable to these nonhazarous waste 
feedstreams (raw materials and fossil fuels) varies across sources, and 
can be significant relative to the level of the straight emissions-
based floor design level and floor, and therefore could inappropriately 
impact a source's ability to comply with the floor standard.\89\
---------------------------------------------------------------------------

    \89\ See USEPA, ``Final Technical Support Document for the HWC 
MACT Standards, Volume III: Selection of MACT Standards,'' September 
2005, Section 17.6. .
---------------------------------------------------------------------------

    b. Comment: The commenter states that EPA must consider 
contributions to emissions from raw materials and fossil fuels, that it 
is irrelevant if sources from outside the pool of best performing 
sources can duplicate emission levels reflecting ``cleaner'' raw 
materials and fossil fuels used by the best performing sources, and 
that sources unable to obtain such ``cleaner'' inputs may always 
upgrade other parts of their systems to achieve that level of 
performance.
    Response: As previously discussed, EPA's methodology does account 
for HAP control of all inputs by assessing system removal efficiency, 
which measures reductions of HAPs from all inputs. Further, nonmercury 
metal HAP emissions attributable to raw materials and fossil fuels are 
effectively controlled with the particulate matter standard, a standard 
that is based on the sources with lowest emissions from best back-end 
control devices. We are not basing any standards on performance of 
sources not ranked as among the best performing.
    c. Comment: The commenter disputes EPA's conclusions that failure 
of sources to meet all of the standards based on a straight emissions 
methodology at once shows that the methodology is flawed. The standards 
are not mutually dependent, so the fact that they are not achieved 
simultaneously is irrelevant. There is no reason a best performer for 
one HAP should be a best performer for other HAP.
    Response: EPA agrees with this comment. On reflection, EPA believes 
that because all our standards are not technically interdependent 
(i.e., implementation of one emission control technology does not 
prevent the source from implementing another control technology), the 
fact that sources are not achieving all the standards simultaneously 
does not indicate a flaw in a straight emissions approach. See Chemical 
Manufacturers Ass'n, 870 F. 2d at 239 (best performing sources can be 
determined on a pollutant-by-pollutant basis so that different plants 
can be best performers for different pollutants).
    d. Comment: Several commenters took the opposite position that EPA 
must assure that all existing source standards must be achievable by at 
least 6 percent of the sources, and that all new source standards must 
be achievable by at least one existing source.
    Response: As discussed above, we are not obligated to establish a 
suite of floors that are simultaneously achievable by at least six 
percent of the sources because the standards are not technically 
interdependent. Nonetheless, the SRE/Feed methodology does result in 
existing floor levels (when combined with the other floor levels for 
sources in the source category) that are simultaneously achievable by 
at least six percent of the sources (or, for source categories that 
have fewer than 30 sources, by at least two or three sources).\90\ 
However, for the new source standards, three of the source categories 
do not include any sources that are simultaneously achieving all the 
standards (incinerators, cement kilns, and lightweight aggregate 
kilns). Again, similar to existing sources, EPA is not obligated to 
establish a suite of new source floors that are simultaneously 
achievable by at least one existing source because these standards are 
not technically interdependent. We conclude that a new source can be 
designed (from a back-end control perspective) to achieve all the new 
source standards.\91\
---------------------------------------------------------------------------

    \90\ These achievability analyses did not account for the 
additional test-to-test variability that we cannot quantify.
    \91\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume V: Emission Estimates and Engineering Costs,'' 
September 2005, Section 4.2.3 for a discussion that explains how 
such a new source could be designed to achieve the new source 
standards.
---------------------------------------------------------------------------

    e. Comment: The commenter criticizes EPA's discussion at 69 FR 
21227-228 indicating that both hazardous waste feed control and back-
end pollution control are superior means of HAP emission control and 
treatment standards should be structured to allow either method to be 
the dominant control mechanism.
    Response: EPA is not relying on this part of the proposed preamble 
discussion as justification for the final rule, with the one exception 
noted in the response to the following comment.
    f. Comment: Considerations of proper waste disposal policy are not 
relevant to MACT floor determinations. In any case, the possibility 
that some commercial waste combustors may upgrade their back-end 
pollution control systems to meet standards reflecting low hazardous 
waste HAP feedrates, or divert wastes to better-controlled units, is 
positive, not negative.
    Response: As discussed in section B.1 above, there are instances 
where standards derived by using a straight emissions approach are 
based on a combination of lowest emitting low feeding sources and 
lowest emitting higher feeding sources. Resulting floor standards would 
thus reflect these low hazardous waste feedrates and could put some 
well-controlled commercial incinerators in the untenable situation of 
having to reduce the amount of hazardous waste that is treated at their 
source. Our database verifies that such an outcome is in fact 
realistic.\92\
---------------------------------------------------------------------------

    \92\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards'', September 
2005, Section 17.4.
---------------------------------------------------------------------------

    This type of standard would operate as a direct constraint on the 
amount of hazardous waste that could be fed to the device, in effect 
depriving a combustion source of its raw material. In this instance, 
hazardous wastes could not be readily diverted to other units because 
the low feeding hazardous waste sources tend not to be commercial 
units. In these circumstances, there would be a significant adverse 
nonair environmental impact. Hazardous waste is required to be treated 
by Best Demonstrated Available Technology (BDAT) before it can be land 
disposed. RCRA sections 3004 (d), (e), (g), and (m); Hazardous Waste 
Treatment Council v. EPA, 866 F. 2d 355, 361 (D.C.Cir. 1990) (upholding 
Best Demonstrated Available Technology treatment requirement). Most 
treatment standards for organic pollutants in hazardous waste can only 
be achieved by combustion. Leaving some hazardous wastes without a

[[Page 59447]]

treatment option is in derogation of these statutory requirements and 
goals, and calls into question whether a treatment standard that has 
significant adverse nonair environmental impacts must be viewed as best 
performing. See Portland Cement Ass'n v. Ruckelshaus, 486 F. 2d 375 , 
386 (D.C. Cir. 1973); Essex Chemical Co. v. EPAEPA, 486 F. 2d 427, 439 
(D.C. Cir. 1973). The commenter's statement that waste disposal policy 
is not relevant to the MACT standard-setting process is not completely 
correct, since section 112 (n) (7) of the Clean Air Act directs some 
accommodation between MACT and RCRA standards for sources combusting 
hazardous waste. Part of this accommodation is using a methodology to 
evaluate best performing sources that evaluates as best performers 
those using the best combination of hazardous waste feed control (among 
other things, an existing control measure under RCRA rules) and system-
wide removal.
    We assessed whether we could address this issue by subcategorizing 
commercial incinerators and on-site incinerators. Applying the straight 
emission approach to such a subcategorization scheme, however, yields 
anomalous results due to the scarcity of available and complete 
compliance test data from commercial incinerators. Calculated floor 
levels for semivolatile metals and low volatile metals for the 
commercial incinerator subcategory equate to 2,023 and 111 [mu]g/dscm, 
respectively (both higher than the current interim standards).\93\ We 
conclude that the SRE/Feed methodology better addresses this issue 
because it yields floor levels that better represent the performance of 
the best performing commercial incinerators and onsite incinerators 
alike by applying equal weights to hazardous waste feed control and 
back-end control in the ranking process.
---------------------------------------------------------------------------

    \93\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards'', September 
2005, Section 4. and Appendix C, Table ``E-INC-SVM-CT-COM'' and 
Table ``E-INC-LVM-CT-COM''
---------------------------------------------------------------------------

    EPA notes, however, that its choice of the SRE/Feed methodology is 
justified independent of considerations of adverse impact on hazardous 
waste treatment and disposal.
    Comment: The commenter reiterates its comments with respect to 
floor levels for new sources.
    Response: EPA's previous responses to comments apply to both new 
and existing source standards.
    Comment: Two commenters recommend that EPA define the single best 
performing source as that source with the lowest aggregated SRE/Feed 
aggregated score (as proposed), as opposed to the source with the 
lowest emissions among the best performing existing sources (an 
approach on which we requested comment).
    Response: We agree with the commenters because this is consistent 
with our methodology for defining best performers for existing sources 
and assessing their level of performance. We note, however, that with 
respect to the new source standards, we encountered two instances where 
the SRE/Feed methodology identified multiple sources with identical 
single best aggregated scores, resulting in a tie for the best 
performing source. This occurred for the mercury and low volatile metal 
new source standards for incinerators. In these instances, EPA applied 
a tie breaking procedure that resulted in selecting as the single best 
performing source as that source (of the tied sources) with the lowest 
emissions. We believe this is a reasonable interpretation of 
section112(d)(3), which states the new source standard shall not be 
less stringent than the emission control that is achieved in practice 
by the best controlled similar source (``source'' being singular, not 
plural). Moreover, we believe use of the emission level as the tie-
breaking criteria is reasonable, not only because it is a measure of 
control, but because we have already fully accounted for hazardous 
waste feedrate control and system removal efficiency in the ranking 
methodology. To choose either of these factors to break the tie would 
give that factor disproportionate weight.

C. Air Pollution Control Technology Methodologies for the Particulate 
Matter Standard and for the Total Chlorine Standard for Hydrochloric 
Acid Production Furnaces

    At proposal, EPA used what we termed ``air pollution control 
technology'' methodologies to estimate floor levels for particulate 
matter from all source categories as a surrogate for non-mercury HAP 
metals, and for total chlorine from hydrochloric acid furnace 
production furnaces. 69 FR at 21225-226. Under this approach, we do not 
estimate emission reductions attributable to feed control, but instead 
assess the performance of back-end control technologies.\94\ We are 
adopting the same methodologies for these HAP in the final rule. 
Because the details of the approaches differ for particulate matter and 
for total chlorine, we discuss the approaches separately below.
---------------------------------------------------------------------------

    \94\ See generally USEPA, ``Technical Support Document for the 
HWC MACT Standards, Volume III: Selection of MACT Standards'', 
September 2005, Section 7.4 and 7.5.
---------------------------------------------------------------------------

1. Air Pollution Control Device Methodology for Particulate Matter
    Our approach to establishing floor standards for particulate matter 
raises three major issues.
    The first issue is whether particulate matter is an appropriate 
surrogate for non-enumerated HAP metals from all inputs, and for all 
non-mercury HAP metals in raw material and fossil fuel inputs. This 
issue is discussed at section IV.A of this part, where we conclude that 
particulate matter is indeed a reasonable surrogate for these metal 
HAP.
    The second issue is why EPA is not evaluating some type of feed 
control for the particulate matter floor. There are two potential types 
of feed control at issue: hazardous waste feed control of nonenumerated 
metals, and feed control of non-mercury HAP metals in raw material and 
fossil fuel inputs. With respect to feed control of non-enumerated 
metals in hazardous waste, as discussed in more detail in section IV.A 
of this part, we lack sufficient reliable data on non-enumerated metals 
to assess their feedrates in hazardous waste. In addition, there are 
significant questions about whether feedrates of the non-enumerated 
metals can be optimized along with SVM and LVM feedrates. We also have 
explained elsewhere why control of hazardous waste ash feedrate would 
be technically inappropriate, since it would not properly assess feed 
control of nonenumerated metals in hazardous waste. See also 69 FR at 
21225.
    We have also explained why we are not evaluating control of 
feedrates of HAP metals in raw materials and fossil fuels to hazardous 
waste combusters: it is an infeasible means of control. See section B 
of this part. We consequently are not evaluating raw material and 
fossil fuel ash feed control in determining the level of the various 
floors for particulate matter.
    a. The methodology. The final issue is the means by which EPA is 
evaluating back-end control. Essentially, after determining (as just 
explained) that back-end control is the means of controlling non-
mercury metal HAP and that particulate matter is a proper surrogate for 
these metals, EPA is using its engineering judgment to determine what 
the best type of air pollution control device (i.e., back-end control) 
is to control particulate matter (and, of course, the contained HAP 
metals). We then ascertain the level of performance by taking the 
average of the requisite number of sources (either 12 % or five,

[[Page 59448]]

depending on the size of the source category) equipped with the best 
back-end control with the lowest emissions.\95\ These floor standards 
are therefore essentially established using a straight emissions 
methodology. We have determined that baghouses (also termed fabric 
filters) are generally the best air pollution control technology for 
control of particulate matter, and that electrostatic precipitators are 
the next best.
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    \95\ As explained in the responses below, the approach varies 
slightly if the requisite number of sources do not all use the best 
back-end pollution control technology. In that case, EPA includes in 
its pool of best performers the lowest emission levels from sources 
using the next best pollution control technology.
---------------------------------------------------------------------------

    b. Why not select the lowest emitters? Although sources with 
baghouses tended to have the lowest emission levels for particulate 
matter, this was not invariably the case. There are certain instances 
when sources controlled with electrostatic precipitators (or, in one 
instance, a venturi scrubber) had lower emissions in individual test 
conditions than sources we identified as best performing which were 
equipped with baghouses.\96\ Under the commenter's approach, we must 
always use these lowest emitting sources as the best performers.
---------------------------------------------------------------------------

    \96\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' September 
2005, Section 22.
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    We again disagree. We do not know if these sources equipped with 
control devices other than baghouses with lower emissions in single 
test conditions would actually have lower emissions over time than 
sources equipped with baghouses because we cannot assess their 
uncontrollable emissions variability over time. Our data suggests that 
they likely are not better performing sources. We further conclude that 
our statistical procedures that account for these sources' within test, 
run-to-run emissions variability underestimates these sources long-term 
emissions variability. This is not the case for sources equipped with 
baghouses, where we have completely assessed, quantified, and accounted 
for long-term, test-to-test emissions variability through application 
of the universal variability factor.\97\ The sources equipped with 
control devices other than baghouses with lower snapshot emissions data 
could therefore have low emissions in part because they were operating 
at the low end of the ``uncontrollable'' emissions variability profile 
for that particular snapshot in time. The basis for these conclusions, 
all of which are supported by our data, are found in section 16 of 
volume III of the technical support document.
---------------------------------------------------------------------------

    \97\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' September 
2005, Section 5.3.
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    We therefore conclude sources equipped with baghouses are the best 
performers for particulate matter control not only based on engineering 
judgment, but because we are able to reliably quantify their likely 
performance over time. The straight emissions methodology ignores the 
presence of long-term emissions variability from sources not equipped 
with baghouses, and assumes without basis that these sources are always 
better performing sources in instances where they achieved lower 
snapshot emissions relative to the emissions from baghouses, emissions 
that have notably already been adjusted to account for long-term 
emissions variability.
    A straight emissions approach also results in inappropriate floor 
levels for particulate matter because it improperly reflects/includes 
low ash feed when identifying best performing sources for particulate 
matter. 69 FR at 21228. For example, the MACT pool of best performing 
liquid fuel boilers for particulate matter under the straight emissions 
approach includes eight sources, only one of which is equipped with a 
back-end control device. These sources have low particulate matter 
emissions solely because they feed low levels of ash. The average ash 
inlet loadings for these sources are well over two orders of magnitude 
lower than the average ash inlet loading for the best performing 
sources that we identify with the Air Pollution Control Technology 
approach. (Of course, since ash loadings are not a proper surrogate for 
HAP metals, these sources' emissions are lowest for particulate matter 
but not necessarily for HAP metals.) The straight emissions approach 
would yield a particulate matter floor level of 0.0025 gr/dscf (with a 
corresponding design level of 0.0015 gr/dscf). There is not one liquid 
fuel boiler that is equipped with a back-end control that achieved this 
floor level, much less the design level. The best performing source 
under the air pollution control technology approach, which is equipped 
with both a fabric filter and HEPA filter, did not even make the pool 
of best performing sources for the straight emissions approach. Yet 
this unit has an excellent ash removal efficiency of 99.8% and the 
lower emitting devices' removal efficiencies are, for the most part, 0% 
because they do not have any back-end controls. EPA believes that it is 
arbitrary to say that these essentially uncontrolled devices must be 
regarded as ``best performing'' for purposes of section 112(d)(3). We 
therefore conclude that a straight emissions floor would not be 
achievable for any source feeding appreciable levels of ash, even if 
they all were to upgrade with baghouses, or baghouses in combination 
with HEPA filters, and that a rote selection of lowest emitters as best 
performers can lead to the nonsensical result of uncontrolled units 
being classified as best performers.
    Comment: Commenter claims end-of-stack control technology is not 
the only factor affecting emissions of particulate matter, stating that 
EPA admits that particulate matter emission levels are affected by the 
feedrate of ash. Accordingly, the performance of a source's end-of-
stack control technology is not a reasonable estimate of that source's 
total performance.
    Response: The particulate matter standard serves as a surrogate 
control for the non-enumerated metals in the hazardous waste streams 
(for all source categories), and all nonmercury metal HAP in the 
nonhazardous waste process streams (essentially, raw materials and 
fossil fuels) for cement kilns, lightweight aggregate kilns, and liquid 
fuel boilers. The commenter suggests that the APCD approach 
inappropriately ignores HAP feed control in the assessment of best 
performing sources. We conclude that it would not be appropriate to use 
a methodology that directly assesses feed control, such as the SRE/Feed 
methodology, to determine particulate matter floors. First, direct 
assessment of total ash feed control would inappropriately assess and 
seek to control (even though variability of raw material and fossil 
fuel inputs are uncontrollable) raw material and fossil fuel HAP input, 
as well as raw material and fossil fuel input. Controlling raw material 
and fossil fuel HAP input is infeasible, as previously discussed. It 
also inappropriately limits theses sources' feedstocks that are 
necessary for their associated production process.
    Second, we do not believe that developing a floor standard based on 
hazardous waste feed control of nonenumerated metals (as opposed to 
feed control of these metals in raw material and fossil fuels) is 
appropriate or feasible. In part four, section IV.A, we explain that we 
lack the data to reliably assess direct feedrate of these metals in 
hazardous waste. In addition, we also discuss that it is unclear (the 
lack of certainty resulting from the sparse available data) that 
hazardous waste feed control of the nonenumerated metals is feasible. 
The majority of these metals are not directly regulated under existing 
RCRA requirements, so sources have optimized control of the other HAP

[[Page 59449]]

metals, raising issues of whether simultaneous optimization of feed 
control of the remaining metals is feasible. Moreover, even if one were 
to conclude that hazardous waste feed control is feasible for the 
nonenumerated metal HAPs, hazardous waste ash feedrates are not 
reliable indicators of nonmercury metal HAP feed control levels and are 
therefore inappropriate parameters to assess in the MACT evaluation 
process. For example, a source could reduce its ash feed input by 
reducing the amount of silica in its feedstreams. This would not result 
in feed control or emission reductions of metal HAP.\98\
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    \98\ For the same reason, even if feed control of total inputs 
(i.e. raw material and fossil fuel as well as hazardous waste fuel) 
were feasible, it would be technically inappropriate to use ash 
feedrates as a surrogate: ash feed control allows sources to 
selectively reduce the ash feeds without reducing the metal HAP 
portion of that feed. Back-end control, in contrast, unselectively 
removes a percentage of everything that is fed to the combustor.
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    Finally, hazardous waste ash feed control levels do not 
significantly affect particulate matter emissions from cement kilns, 
lightweight aggregate kilns, and solid fuel-fired boilers because the 
majority of particulate matter that is emitted originates from the raw 
material and nonhazardous fuel. Hazardous waste ash feed control levels 
also do not significantly affect particulate matter emissions from 
sources equipped with baghouses because these control devices are not 
sensitive to particulate matter inlet loadings.\99\
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    \99\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of Mact Standards,'' September 
2005, Section 3.1.
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    Thus, even if one were to conclude that the nonenumerated metal 
HAPs are amenable to hazardous waste feed control, explicit use of ash 
feed control in a MACT methodology would not assure that each source's 
ability to control either nonmercury metal HAP or surrogate particulate 
matter emissions is assessed. The Air Pollution Control Device 
methodology identifies and assesses (with the surrogate particulate 
matter standard) the known technology that always assures metal HAP 
emissions are being controlled to MACT levels--that technology being 
back-end control.
    Comment: Commenter claims the Air Pollution Control Device approach 
to calculate particulate matter floors is flawed because the 
performance of back-end control technology alone does not reflect the 
performance of the relevant best sources that otherwise would be 
reflected if EPA were to assess performance based on the emission 
levels each source achieved because, as EPA admits, it fails to account 
for the effect of ash feed rate.
    Response: We explain above why the Air Pollution Control Technology 
approach properly identifies the relevant best performing sources for 
purposes of controlling non-mercury metal HAP (measured as particulate 
matter), irrespective of ash feed rates. Typically, this results in 
selecting the sources with the lowest particulate matter emission 
rates, the result the commenter advocates. This is because we evaluate 
sources with the best-performing (e.g. lowest emitting) baghouses, and 
particulate matter emissions from baghouses are not significantly 
affected by inlet particulate matter loadings. Where the pool of best 
performing sources includes sources operating some other type of back-
end control device (because insufficient numbers of sources are 
equipped with baghouses to comprise 12% of sources, or five sources 
(depending on the size of the source category)), we again use the 
lowest particulate matter emission level from the sources equipped with 
second best technology. Although these data do not reflect test-to-test 
variability, they are the best remaining data in EPA's possession to 
estimate performance and EPA is therefore, as required by section 112 
(d) (3) (A) and (B), using the data to fill out the requisite 
percentage of sources for calculating floors.
    Comment: Commenter states that EPA has failed to demonstrate how it 
reasonably estimated the actual performance of each source's end-of-
stack control technology because: (1) It failed to acknowledge that 
there can be substantial differences between the performance of 
different models of the same type of technology; and (2) it did not 
explain or support its rankings of pollution control devices.
    Response: As discussed in sections 7.4 and 16.2 of volume III of 
the technical support document and C.1 of this comment response 
section, we rank associated back-end air pollution control device 
classes (e.g., baghouses, electrostatic precipitators, etc.), after 
assessing particulate matter control efficiencies from hazardous waste 
combustors that are equipped with the associated back-end control 
class. The data used to make this assessment are included in our 
database. We also evaluated particulate matter control efficiencies 
from other similar source categories that also use these types of 
control systems, such as municipal waste combustors, medical waste 
incinerators, sewage sludge combustors, coal-fired boilers, oil fired 
boilers, non-hazardous industrial waste combustors, and non-hazardous 
waste Portland cement kilns.\100\
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    \100\ See USEPA, ``Technical Support Document for th HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' September 
2005, Section 5.3 and 16.2, for further discussion.
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    After we assign a ranking score to each back-end control class, we 
determine the number of sources that are using each of these control 
technology classes. We then identify the MACT control technology or 
technologies to be those best ranked back-end controls that are being 
used by 12 percent of the sources (or used by five sources in instances 
where there are fewer than 30 sources). We then look only at those 
sources using MACT back-end control and rank order all these sources 
first by back-end control type, and second by emissions. For example, 
in instances where there is more than one MACT back-end control, we 
array the emissions from the sources equipped with the top ranked back-
end controls from best to worst (i.e., lowest to highest), followed by 
the emissions from sources equipped with the second ranked back-end 
controls from best to worst, and so on. We then determine the 
appropriate number of sources to represent 12 percent of the source 
category (5 in instances where there are fewer than 30 sources). If 10 
sources represented 12% of the sources in the source category, we would 
then select the emissions from best ranked 10 sources in accordance 
with this ranking procedure to calculate the MACT floor. This 
methodology results in selection of lowest emitters using best back-end 
air pollution control as pool of the best performing sources.
    The commenter is correct that there can be differences between the 
performance of different models of the same type of technology. We are 
not capable of thoroughly assessing differences in designs of each air 
pollution control device in a manner that could be used in the MACT 
evaluation process, so that we would only select, for example, 
baghouses of a certain type. Each baghouse, for example, will be 
designed differently and thus will have different combinations of 
design aspects that may or may not make that baghouse better than other 
baghouses (e.g., bag types, air to cloth ratios, control mechanisms to 
collect accumulated filter cake and maintain optimum pressure drops). 
We also do not have detailed design information for each source's air 
pollution control system; such an assessment would therefore not be

[[Page 59450]]

possible even if the information could be used to assess relative 
performance.
    We instead account for this difference by selecting sources with 
the lowest emissions that are using the defined MACT back-end controls 
to differentiate the performance among those sources that are using 
that technology (the best performer being the source with the lowest 
emissions, as just explained). For example, in situations where more 
than 12% of the sources are using the single best control technology 
(e.g., more than 12% of incinerators use baghouses to control 
particulate matter), we use the emissions from the lowest emitting 
sources equipped with baghouses to calculate the MACT floor. In 
instances where there are two defined MACT technologies (i.e., 12% of 
sources do not use the single best control technology), we use all the 
emissions data from sources equipped with the best ranked control 
class, and then subsequently use only the lowest emissions from the 
sources equipped with the second ranked back-end controls.
    Comment: EPA did not say how it picked the best performers if more 
than twelve percent used the chosen technologies. If EPA used emissions 
data to differentiate performance, the Agency is necessarily 
acknowledging that emissions data are a valid measure of sources' 
performance--in which case the Agency's claims to the contrary are 
arbitrary and capricious.
    Response: We did use emissions data to select the pool of best 
performers where over 12% use the best type of emissions control 
technology, as explained in the previous response. Emissions data is 
obviously one means of measuring performance. EPA's position is that it 
need not be the exclusive means, in part because doing so leads to 
arbitrary results in certain situations. Our use of emission levels to 
rank sources that use the best particulate matter control (i.e., 
baghouses) does not lead to arbitrary results, however. First, we are 
assessing emission levels here as a means of differentiating sources 
using a known type of pollution control technology. More importantly, 
the adjusted emission levels from sources equipped with baghouses are 
the most accurate measures of performance because these emissions have 
been statistically adjusted to accurately account for long-term 
variability through application of the universal variability factor.
    Comment: Commenter states that EPA, in its support for its Air 
Pollution Control Technology Approach used to calculate particulate 
matter floors, claims that an emissions-based approach would result in 
floor levels that ``could not necessarily be achieved by sources using 
the chosen end-of-stack technology,'' citing 69 FR at 21228. Commenter 
claims that it is settled law that standards do not have to be 
achievable through the use of any given control technology, and that it 
is also erroneous to establish floors at levels thought to be 
achievable rather than levels sources actually achieve.
    Response: EPA is not establishing floor levels based on assuring 
the standards are achievable by a particular type of end-of-stack 
technology (or, for that matter, any end-of-stack technology). The 
floor levels in today's final rule reasonably estimate average 
performance of the requisite percent of best performing sources without 
regard for whether the levels themselves can be achieved by a 
particular means. Floor standards for particulate matter are based on 
the performance of those sources with the lowest emissions using the 
best back-end control technology (most often baghouses, and sometimes 
electrostatic precipitators). EPA uses this approach not to assure that 
the floors are achievable by sources using these control devices, but 
to best estimate performance of the best performing sources, including 
these sources' variability.
2. Total Chlorine Standard for Hydrochloric Acid Production Furnaces
    We are adopting the methodology we proposed to estimate floor 
levels for total chlorine from hydrochloric acid production furnaces. 
69 FR at 21225-226. As stated there, we are defining best performers as 
those sources with the best total chlorine system removal efficiency. 
We are not assessing a level of control attributable to control of 
chlorine in feedstocks because this would simply prevent these furnaces 
from producing their ultimate product. Further details are presented in 
responses below.
    Comment: Basing the standard for hydrochloric acid production 
furnaces on the basis of system removal efficiency rather than chlorine 
emission reduction is impermissible. Even though these devices' purpose 
is to produce chlorinated product, the furnaces can use less 
chlorinated inputs. EPA's proposed approach is surreptitious, an 
impermissible attempt to assure that the standards are achievable by 
all sources using EPA's chosen technology, the approach already 
rejected in CKRC.
    Response: EPA disagrees. There is nothing in the text of the 
statute that compels an approach that forces sources to produce less 
product to achieve a MACT floor standard. Yet this is the consequence 
of the comment. If standards were based on levels of chlorine in 
feedstock to these units, less product would be produced since there 
would be less chlorine to recover. EPA has instead reasonably chosen to 
evaluate best performing/best controlled sources for this source 
category by measuring the efficiency of the entire chlorine emission 
reduction system. Indeed, the situation here is similar to that in 
Mossville, where polyvinyl chloride production units fed raw materials 
containing varying amounts of vinyl chloride depending on the product 
being produced. This led to variable levels of vinyl chloride in plant 
emissions. Rather than holding that EPA must base a floor standard 
reflecting the lowest amount of vinyl chloride being fed to these 
units, the court upheld a standard estimating the amount of pollution 
control achievable with back-end control. 370 F. 3d at 1240, 1243. In 
the present case, as in Mossville, the standard is based on actual 
performance of back-end pollution control (although here EPA is 
assessing actual performance of the control technology rather than 
estimating performance by use of a regulatory limit, making the 
situation here a fortiorari from that in Mossville), and does not 
reflect ``emission variations not related to technological 
performance''. 370 F. 3d at 1240.
    It also should be evident that EPA is not establishing a standard 
to assure its achievability by a type of pollution control technology, 
as the commenter mistakenly asserts. The standard for total chlorine is 
based on the average of the best five sources `` best meaning those 
sources with greatest (most efficient) system removal efficiencies. EPA 
did not, as in CKRC, establish the standard using the highest emission 
limit achieved by a source operating a particular type of control.
    Comment: The commenter generally maintains that EPA's methodology 
to determine total chlorine floors for hydrochloric acid production 
furnaces fails to capture other means of HAP emission control that 
otherwise would be captured if EPA were assess performance based on the 
emission levels each source achieved.
    Response: As discussed above, the standard for total chlorine is 
based on the sources with the best system removal efficiencies. System 
removal efficiency encompasses all means of MACT floor control when 
assessing relative performance because: (1) Chlorine feed control is 
not a MACT floor technology for these sources; and (2) the measure of 
system removal efficiency accounts for every other controllable factor 
that can affect

[[Page 59451]]

emissions (e.g., operating practices, worker training, proper 
maintenance, pollution control device type, etc).

D. Format of Standards

1. Thermal Emissions
    EPA proposed, and is finalizing standards for HAP metals and 
chlorine (the HAPs amenable to hazardous waste feed control) emitted by 
energy recovery units (cement kilns, lightweight aggregate kilns, and 
liquid fuel boilers) expressed in terms of pounds of HAP attributable 
to the hazardous waste fuel per million british thermal units (BTUs) of 
hazardous waste fired. 69 FR at 21219-20. EPA received many comments on 
this issue to which we respond below and in the Response to Comment 
Document. Some initial discussion of the issue is appropriate, however.
    a. Expressing Standards in Terms of a Normalizing Parameter is 
Reasonable. First, using a thermal emissions form of a standard is an 
example of expressing standards in terms of a normalizing parameter. 
EPA routinely normalizes emission standards either by expressing them 
as stack HAP concentrations or by expressing the standards in units of 
allowable mass emissions per amount of production or raw material 
processed. Emission concentration-based standards normalize the size of 
each source by accounting for volumetric gas flowrate, which is 
directly tied to the amount of raw material each source processes (and 
subsequently the amount of product that is produced). Metal and 
particulate matter emission standards for commercial and industrial 
solid waste incinerators are expressed in emission concentration 
format. See Sec.  60.2105. The particulate matter standard for Portland 
cement kilns is expressed as mass of allowable emissions per mass of 
raw material processed. See Sec.  63.1342. The particulate matter, 
mercury, and hydrogen chloride standards for nonhazardous waste 
industrial boilers are expressed as pounds of allowable emissions per 
million British thermal units (BTUs). See Sec.  63.7500.
    Technology-based standards typically normalize emissions because 
such a format assures equal levels of control across sources per amount 
of raw material that is processed, and allows EPA to equally assess 
source categories that comprise units that differ in size. By 
normalizing the emissions standard we better ensure the same percentage 
of emission reduction per unit of raw material processed by each 
source.\101\ See Weyerhaeuser v. Costle, 590 F. 2d 1011, 1059 (D.C. 
Cir. 1978) (technology-based standards are typically expressed in terms 
of volume of pollutants emitted per volume of some type of unit of 
production).
---------------------------------------------------------------------------

    \101\ A more familiar example of normalization is the Earned Run 
Average (ERA), which normalizes a baseball pitchers' earned runs on 
the basis of nine innings pitched in order to make comparisons among 
pitchers possible.
---------------------------------------------------------------------------

    There is no legal bar to this approach since the statute does not 
directly address the question of whether a source emitting 100 units of 
HAP per unit of production but 100 units of HAP overall is a better 
performer (or, for new sources, better controlled) than a source 
emitting 10 units of HAP per unit of production but emitting 101 units 
overall.\102\ One commenter appeared to suggest that we should assess 
performance on mass feedrates and mass emission rates, without 
normalizing. Such an approach would yield nonsensical results because 
the best performing sources would more likely be the smallest sources 
in the source category (smaller sources generally have lower mass 
emission rates because they process less hazardous waste). This would 
likely yield emission standards that would not be achievable by the 
larger sources that more likely are better controlled sources based on 
a HAP removal efficiency basis.\103\ Normalization by unit of 
production is another way of expressing unit size, so that normalizing 
on this basis is a reasonable alternative to subcategorization on a 
plant size-by-plant size basis. See section 112(d)(1) (size is an 
enumerated basis for subcategorizing).
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    \102\ Or, put another way, the statute does not directly address 
the question of whether a small source that emits 10 units of HAP is 
better than a much larger source with better back-end control (but 
feeding the same raw material at a higher mass feedrates) that emits 
100 units of HAP.
    \103\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' September 
2005, Section 6.0.
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    b. Using Hazardous Waste Thermal Input as the Normalizing Parameter 
is Permissible and Reasonable. Normalization of standards based on 
thermal input is analogous. For energy recovery units (in this rule, 
kilns and most liquid fuel boilers), normalizing on the basis of 
thermal input uses a key feed input as the normalizing parameter, 
allowing comparison of units with different inputs rather than 
separately evaluating these units by size and type (see section 
112(d)(1)). Again, this approach is legally permissible. The statute 
does not answer the question of which source is better performing, the 
source emitting 100 pounds of HAP per million BTUs hazardous waste but 
100 pounds of HAP overall or the source emitting 10 pounds of HAP per 
million BTUs hazardous waste but emitting 101 pounds overall.
    The approach also is reasonable. First, as with other standards 
expressed in normalized terms, by normalizing the emissions standard we 
ensure the same percentage of emission reduction per unit of raw 
material processed by each source, thus allowing meaningful comparison 
among sources. For example, emission concentration-based standards 
normalize the size of each source by accounting for volumetric gas 
flowrate, which is directly tied to the amount of raw material each 
source processes (and subsequently to the amount of product that is 
produced), and assures equal levels of control per amount of product. 
Normalization on the basis of HAP amount in hazardous waste per BTU 
level in the hazardous waste similarly assures equal levels of control 
across sources per amount of raw material that is processed. Here, the 
raw material is the hazardous waste fuel, expressed as units of energy. 
It is reasonable to regard a hazardous waste fuel as a raw material to 
an energy recovery device. Indeed, fuels are the only input to boilers, 
so fuels are necessarily such units' sole raw 
material.<SUP>104 105</SUP> Hazardous waste burning cement kilns and 
lightweight aggregate kilns produce a product in addition to recovered 
energy and so process other raw materials. However, the reason these 
units use hazardous waste as inputs is typically to recover usable 
energy from the wastes. Hence, the hazardous waste fuel is reasonably 
viewed as a raw material to these devices.
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    \104\ EPA thus has expressed the MACT standards for particulate 
matter, mercury, and hydrogen chloride standards for nonhazardous 
waste industrial boilers as pounds of allowable emissions per 
million BTUs. Sec.  See 63.7500. This normalization considers the 
total heat input into the combustion device. Normalizing by total 
heat input would not be appropriate for hazardous waste combustors 
for metals and chlorine because this would implicitly account for, 
and in turn require the use of, feed control of HAP in non hazardous 
waste fuels. This is inappropriate for the reasons discussed in 
Section III.B of this Part.
    \105\We distinguish (i.e., subcategorize) liquid fuel boilers 
that process hazardous waste with heating values less than 10,000 
BTU/lb from those processing hazardous wastes with heating content 
greater than 10,000 BTU/lb. Although boilers that process hazardous 
waste with heating values less than 10,000 BTU/lb are still 
considered to be energy recovery units, we conclude a thermal 
emissions normalization approach for these sources is not 
appropriate. See Part Four, Section VI.D.
---------------------------------------------------------------------------

    In this regard, we note that our choice of normalizing parameter 
essentially says that best performers with respect to hazardous waste 
fuel burned in energy recovery units are those using the lowest HAP 
feedrate (for metals and chlorine) per amount of energy

[[Page 59452]]

recovered.\106\ This approach accords well with the requirement in 
section 112(d)(2) that EPA take energy considerations into account in 
developing MACT, and also that the Agency consider front-end means of 
control such as input substitution (section 112(d)(2)(A)). In addition, 
our choice furthers the RCRA goal of encouraging properly conducted 
recycling and reuse (RCRA section 1003(b)(6)), which is of relevance 
here in that Congress directed EPA to consider the RCRA emission 
controls for hazardous waste combustion units in developing MACT 
standards for these units, and to ensure ``to the maximum extent 
possible, and consistent with [section 112 ]'' that section 112 
standards are ``consistent'' with the RCRA scheme. CAA section 
112(n)(7).\107\ Conversely, emission concentration-based standards, the 
methodology that otherwise would be used to calculate emission 
concentration-based standards, may result in standards that are biased 
against sources that recover more energy from hazardous waste. This may 
discourage sources from recovering energy from hazardous waste because 
such standards do not normalize each source's allowable emissions based 
on the amount of hazardous waste it processes for energy recovery 
purposes. See 69 FR at 21219 and responses below.
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    \106\ As explained earlier, the ultimate ranking of best 
performers then further evaluates system removal efficiency, best 
performers then being defined in terms of the combination of 
hazardous waste thermal feed and system removal efficiency. See 
USEPA, ``Technical Support Document for the HWC MACT Standards, 
Volume III: Selection of MACT Standards'', September 2005, Section 
7.3.
    \107\ EPA would adopt the thermal format for the standards, 
however, whether or not the approach furthered RCRA objectives.
---------------------------------------------------------------------------

    Second, use of this normalizing parameter makes it much more likely 
that hazardous waste feed controls will be utilized by these devices as 
an aspect of emissions control. See section 112(d)(2)(A) (use of 
measures reducing the volume of pollutants emitted through 
``substitution of materials''); CKRC, 255 F. 3d at 865 (EPA to consider 
means of control in addition to back-end pollution control technology 
when establishing MACT floors). As explained in our discussion of the 
SRE/Feed methodology, the MACT floor level for metals and chlorine 
reflects the best combination of hazardous waste feedrate, and total 
HAP removal efficiency. See section III.B. However, if standards for 
energy recovery units are expressed in terms of mass of HAP per volume 
of stack gas, then it would be relatively easy for these energy 
recovery devices to achieve a standard, without decreasing 
concentrations of HAP in their hazardous waste fuels, by diluting the 
HAP contribution of hazardous waste with emissions from fossil fuel. A 
thermal emissions format prevents this type of dilution from happening 
because it ignores additions of stack gases attributable to burning 
fossil fuels. Weyerhaeuser, 590 F. 2d at 1059 (use of production of a 
unit as a normalizing parameter serves ``the commendable purpose'' of 
preventing plants from achieving emission limitations via dilution).
    For example, assume there are two identical energy recovery units 
with identical back-end control devices (that reflect the performance 
of the average of the best performing sources). Source A fulfills 25% 
of its energy demand from the combustion of hazardous waste; source B 
fulfills 50% of its energy demand from the combustion of hazardous 
waste. Also assume that the hazardous waste for these two sources have 
equivalent energy contents. If these sources were required to comply 
with an emission concentration based-standard (e.g., [mu]g/dscm), 
source A would be allowed to feed hazardous waste containing twice the 
metal content (on a mass concentration basis, e.g., ppm), and would be 
allowed to emit metal HAP at the same mass emission rate relative to 
source B. This is because this source is effectively diluting its 
emissions with the emissions that are being generated by the fossil 
fuels.\108\ A thermal emissions standard format does not allow sources 
to dilute their emissions with the emissions from fossil fuel inputs 
because it directly regulates the emissions and feeds associated with 
the hazardous waste fuel. Under a thermal emissions format both sources 
would be required to feed hazardous waste with the same thermal feed 
concentrations (on a lb HAP per million BTU hazardous waste basis), and 
source A would be required to process hazardous waste with an 
equivalent concentration of metal HAP (on a mass basis) and also be 
required to emit half as much metal HAP (on a mass emission rate basis) 
relative to source B, because source A is processing half as much 
hazardous waste fuel, thus vindicating the hazardous waste feed control 
aspect of the standard (see also note below regarding the likelihood of 
sources using hazardous waste feed control). Further, the thermal feed 
concentration with which these sources must comply reflects the feed 
control of the average performance of the best performing sources (on a 
mass of HAP per million BTU basis). Such a requirement assures that 
these sources are processing the cleanest hazardous waste fuels to 
recover energy and are reducing HAP emissions to MACT levels.
---------------------------------------------------------------------------

    \108\ This example assumes there are no HAP emissions 
attributable to the fossil fuels.
---------------------------------------------------------------------------

    We note that it would not be appropriate to express the emission 
standards for incinerators, hydrochloric acid production furnaces, and 
solid fuel boilers in terms of thermal emissions. As just explained, 
the choice of a normalizing parameter is fitted to the nature of the 
device to which it is applied in order to allow the most meaningful 
comparisons between devices of like type. We therefore conclude that a 
thermal emissions format (i.e., normalizing parameter) for incinerators 
is not appropriate because the primary function of incinerators is to 
thermally treat hazardous waste (as opposed to recovering energy from 
the hazardous waste). See 67 FR at 17362 (April 19, 1996). Our database 
indicates that most incinerators processed hazardous waste during their 
emissions tests that had, on average, heating values below 10,000 BTU/
lb.\109\ We have emission test hazardous waste heating value 
information for 62 incinerators in our database. Of these 62 sources, 
40 sources processed hazardous waste with an average heating value of 
less than 10,000 BTU/lb. The other 22 sources processed hazardous waste 
with heating values greater than 10,000 BTU/lb in at least one test 
condition, although we note that 14 of these 22 sources also processed 
hazardous waste in different test conditions with heating values lower 
than 10,000 BTU/lb.\110\
---------------------------------------------------------------------------

    \109\ As discussed later, the heating values of hazardous wastes 
processed at cement kiln and lightweight aggregate kilns are 
primarily 10,000 BTU/lb or greater.
    \110\ These data are based on a compilation of heating contents 
for every incinerator test condition in the database where the 
source reported such heating content, and include both the most 
recent test conditions as well as older test conditions. Incinerator 
test condition heating values range from a low of 790 to a high of 
19,800 BTU/lb, with a median value of 7800 BTU/lb.
---------------------------------------------------------------------------

    We assessed whether we should subcategorize incinerators, similar 
to how we subcategorize liquid fuel boilers, based on the BTU content 
of the hazardous waste. Incinerators do recover energy from processing 
high BTU wastes. Some incinerators are equipped with waste heat 
boilers, and high BTU hazardous waste can displace fossil fuels that 
otherwise would have to be burned to thermally treat low BTU 
wastestreams. However, such energy recovery is considered to be a 
secondary product because their primary function is to thermally treat 
hazardous waste. A

[[Page 59453]]

thermal emissions normalization approach for incinerators that combust 
hazardous wastes with heating values greater than 10,000 BTU/lb would 
therefore not be appropriate because the normalized parameter would not 
be tied to the primary production output that results from the 
processing of hazardous waste (i.e., treated hazardous waste). In 
confirmation, no commenters suggested that we apply a thermal emissions 
format to incinerators.
    We also conclude that a thermal emission format is inappropriate 
for hydrochloric acid production furnaces. These devices recover 
chlorine, an essential raw material in the process, from hazardous 
waste. The classic normalizing parameter of amount of product (HCl) 
produced is therefore the obvious normalizing parameter for these 
sources. It is true that some hydrochloric acid production furnaces 
recover energy from high BTU hazardous wastes. See 56 FR at 7141/1 and 
7141-42 (Feb. 21, 1991). Some sources are equipped with waste heat 
boilers, and high BTU wastes help sustain the combustion process, which 
is necessary to liberate the chlorine from the wastestreams prior to 
recovering the chlorine in the scrubbing systems. Again, energy 
recovery is not the primary function of these types of sources.\111\ 
Hydrochloric acid production furnace hazardous waste heating values 
range from 1,100 to 11,000 BTU/lb (the median energy content for these 
sources is slightly above 6,000 BTU/lb). The range of hazardous waste 
heating contents from these sources is much lower than the ranges for 
cement kilns, lightweight aggregate kilns, and liquid fuel boilers, 
supporting the premise that energy recovery is of secondary importance. 
In addition, and critically, the hazardous waste that is processed in 
these units contains high concentrations of chlorine, confirming that 
the wastes serve as feedstock for hydrochloric acid production, even if 
the wastes also have energy value.\112\ No commenters suggested that we 
apply a thermal emissions format to hydrochloric acid production 
furnaces.
---------------------------------------------------------------------------

    \111\ EPA notes that when first adopting RCRA air emission 
standards for hydrochloric acid recovery furnaces (then called 
`halogen acid furnaces'), EPA indicated that those furnaces designed 
as boilers would be subject to the emission standards for boilers. 
56 FR at 7040. This determination did not have regulatory 
consequence, since all hydrochloric acid production furnaces were 
subject to the same emission standards whether they were classified 
as boilers or as industrial furnaces. Thus, EPA was not concluding 
that some hydrochloric acid furnaces existed for the primary purpose 
of recovering energy in the 1991 rulemaking. 56 FR at 7139 
(``[Hydrochloric acid recovery furnaces] are typically modified 
firetube boilers that process secondary waste streams containing 20 
to 70 per cent chlorine or bromine to produce a halogen acid product 
by scrubbing acid from the combustion gases'').
    \112\ Hazardous waste chlorine feedrates that are included in 
our database (expressed as MTECs) range from a low of 46,000,000 
[mu]g/dscm to a high of 294,000,000 [mu]g/dscm. On a mass chlorine 
percentage basis, these wastes range from 17% to 82%, noting that 
these percentages did not include the chlorine that was also spiked 
during the emissions tests). See USEPA, ``Technical Support Document 
for the HWC MACT Standards, Volume III: Selection of MACT 
Standards'', September 2005, Section 15.
---------------------------------------------------------------------------

    We consider the processing of hazardous waste in solid fuel boilers 
to be more reflective of energy recovery (relative to incinerators and 
hydrochloric acid production furnaces) because these sources directly 
recover the heat that is released from the combustion of the waste 
streams. However, as stated at proposal, not all these sources are 
processing hazardous wastes for energy recovery. 69 FR at 21220. These 
boilers are generally not commercial units, and so tend to burn 
whatever hazardous wastes are generated at the facility where they are 
located. Heating values for this source category range from 1,300 to 
10,500 BTU/lb, with a median value of 8,000 BTU/lb. We therefore 
conclude that thermal emission standards for these sources are not 
appropriate because most of these sources are processing hazardous 
waste with energy content lower than 10,000 BTU/lb. As discussed in 
section VI.D, we conclude that 10,000 BTU/lb is an appropriate level 
that distinguishes whether thermal emission standards or mass emission 
concentration-based standards are appropriate. We also note that no 
commenters suggested that we apply a thermal emissions format to solid 
fuel boilers.
    Comment: Commenters state that thermal emission standards are 
inappropriate because sources burning hazardous waste with a higher 
energy content or higher percent hazardous waste firing rate (i.e., one 
that fulfills a greater percentage of its total energy demand from the 
hazardous waste) would be allowed to emit more HAP.
    Response: Part of this comment would apply regardless of what 
normalizing parameter is used. Technology-based standards (including 
MACT standards) are almost always expressed in terms of some type of 
normalizing parameter, i.e., ``X'' amount of HAP may be emitted per 
unit of normalizing parameter. This allows a meaningful comparison 
between units of different size and production capacity. A consequence 
is that the overall mass of HAP emissions varies, but the rate of 
control remains constant per the normalizing unit. As explained in the 
introduction to this section, this approach is both routine and 
permissible.
    Cement kilns, lightweight aggregate kilns, and liquid fuel boilers 
combust hazardous waste to recover valuable energy. Recovering energy 
is an integral part of their production process. As discussed at 
proposal, emission concentration-based standards (and the methodology 
that otherwise would be used to calculate emission concentration-based 
standards) may result in standards that are biased against sources that 
recover more energy from hazardous waste. 69 FR at 21219. This may 
discourage sources from recovering energy from hazardous waste because 
such standards do not normalize each source's allowable emissions based 
on the amount of hazardous waste it processes for energy recovery 
purposes. A source that fulfills 100 percent of its energy demand from 
hazardous waste would be required to limit its mass HAP emissions to 
the same levels as an identical source that satisfies, for example, 
only 10 percent of its energy demand from hazardous waste and 90% from 
coal. This would inappropriately discourage the safe recovery of energy 
from hazardous waste, and could in turn result in greater consumption 
of valuable fossil fuels that otherwise would be consumed.
    Sources which fulfill a greater percentage of their energy demand 
from hazardous waste (either by processing hazardous wastes that are 
higher in energy content, or by simply processing more hazardous waste) 
will be allowed to emit more HAP (on a mass emission rate basis) than 
an identical source that satisfies less of its total energy demand from 
hazardous waste. This is appropriate because: (1) The source fulfilling 
a greater percentage of its energy demand from hazardous waste is 
processing more raw material than the other source (the raw material 
being the energy content of the waste); and (2) The source fulfilling a 
lower percentage of its energy demand requirements from hazardous waste 
would not be allowed to dilute its emissions with nonhazardous waste 
fuels, and we would thus assure that all sources implement hazardous 
waste feed control to levels consistent with MACT.\113\ This

[[Page 59454]]

was illustrated in the example provided in the introduction to this 
comment response section.
---------------------------------------------------------------------------

    \113\ Although the rule does not require use of feed control (or 
any particular means of control to achieve a standard), the rule 
assures that all sources' emissions will reflect the emissions of 
the sources with the best hazardous waste federates expressed in 
terms of amount of HAP per BTU of hazardous waste. Because this 
format eliminates consideration of stack gas attributable to fossil 
fuel emissions, and thus eliminates the dilutive effect of these 
emissions, the likelihood that sources will in fact use hazardous 
waste feed control as part of their control strategy is great.
---------------------------------------------------------------------------

    Similarly, two sources that combust hazardous waste with the same 
energy content and the same metal concentrations (on both a thermal 
concentration and mass-based concentration basis), but at different 
hazardous waste firing rates, would be required to achieve identical 
back-end control device operating efficiencies to comply with a thermal 
emissions-based standard. Holding these factors constant, thermal 
emission standards require sources to achieve identical percent 
reductions of the HAP that is processed within the combustor via 
removal with an air pollution control device. A thermal emission 
standard format is thus equally stringent for these sources on a 
percent HAP removal basis, irrespective of the amount of hazardous 
waste it processes for energy recovery, and better assures that sources 
burning smaller amounts of hazardous waste (from an energy recovery 
perspective) are also controlling emissions as well as the average of 
the best performing sources.
    Sources processing higher energy content hazardous wastes would be 
allowed to feed hazardous wastes with higher metal and chlorine mass-
based concentrations relative to other sources combusting lower energy 
content wastes. To illustrate this, assume there are two sources (named 
C and D) with identical back-end control systems and identical mass 
feedrates of hazardous waste. Also assume the hazardous waste of source 
C has twice the energy content as compared to the hazardous waste 
processed by source D. A thermal emission standard will allow Source C 
to feed a hazardous waste that has twice the metals concentration (as 
measured on a mass basis) as compared to source D, even though both 
sources would be required to comply with equivalent thermal feed rates 
limitations. Notably, however: (1) Source C is displacing (i.e., not 
using) twice as much valuable fossil fuel as the source with the lower 
energy content hazardous waste, and is feeding twice as much raw 
material--the raw material being energy content contained in the 
hazardous waste; (2) source C cannot exceed the feed control levels 
(expressed on a lbs of HAP per million BTU basis) that was achieved by 
the average of the best performing sources (assuming its back-end 
control efficiency is equivalent to the average performance 
demonstrated by the best performing sources); and (3) source D is 
required to have lower mass concentrations of metals in its hazardous 
waste because it is firing poorer quality hazardous waste fuel (from an 
energy recovery perspective) and because it is feeding less of the same 
raw material (measured by energy content). Thus, the thermal emissions 
format appropriately encourages and promotes the processing of clean, 
high energy content hazardous waste fuels (consistent with evaluating 
hazardous waste feed control as an aspect of MACT, and not just relying 
on control solely through use of back end technology), and does so 
equally for all sources because it normalizes the allowable emissions 
based on the amount of energy each source recovers from the hazardous 
waste. Put another way, source C in the above example is controlling 
HAP emissions to the same extent as the average of the best performing 
sources per every BTU of hazardous waste fuel it processes (as is 
source D).
    We note that this is a hypothetical example. In practice the 
average energy content of hazardous waste processed at cement kilns 
does not vary significantly across sources. Cement kilns burn hazardous 
wastes with relatively consistent energy contents because that is what 
their production process necessitates. This is supported by our 
database and by comments received from the Cement Kiln Recycling 
Coalition.\114\ Heating values of hazardous wastes processed at cement 
kilns during compliance tests (information which is included in our 
database) range from 10,300 to 17,600 BTU/lb, with a median value of 
12,400 BTU/lb. We note that these are snapshot representations of 
hazardous waste heating content from these sources that originate from 
compliance tests. We also have long term average hazardous waste 
heating measurements from cement kilns indicating that the heating 
content of the hazardous wastes on average range from 9,900 to 12,200 
BTU/lb, with a median value of 11, 500 BTU/lb. We thus conclude that 
the commenter's concern regarding sources being allowed to emit more 
HAP if they process hazardous waste with higher energy content is 
overstated for these sources.
---------------------------------------------------------------------------

    \114\ See comment submitted by the Cement Kiln Recycling 
Coalition, USEPA, ``Comment Response Document to the Proposed HWC 
MACT Standards, Volume 1: MACT Standards,'' September 2005, Section 
3.3. Also see USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' September 
2005, Section 23.
---------------------------------------------------------------------------

    Energy content of hazardous wastes processed in liquid fuel boilers 
and lightweight aggregate kilns varies more than energy content of 
hazardous wastes processed by cement kilns, and sources with higher 
energy content wastes would be allowed to emit more metals than 
identical sources burning identical volumes of lower energy content 
wastes (although the degree of control is identical per BTU of 
hazardous waste fuel processed).\115\ Again, these are hypothetical 
examples. Each energy recovery unit will have an upper bound on the 
amount of energy it can process from the hazardous waste. Sources that 
process higher energy content hazardous wastes would not necessarily 
feed the same volume of hazardous waste as compared to sources 
processing lower energy content hazardous wastes because they cannot 
exceed the thermal capacity of their combustion unit. Under a thermal 
emission standard format, the mass emission rates that would be allowed 
for identical sources that fulfill 100 percent of their energy demand 
from hazardous waste and that have differing hazardous waste energy 
contents would be identical. Although the source with the higher energy 
content hazardous waste would have a higher allowable mass-based 
hazardous waste feed concentration, this source would have to process 
less hazardous waste (on a mass basis) to remain within its thermal 
capacity. This helps to ensure that its mass HAP emission rate is 
similar to other sources that process lower energy content hazardous 
waste.
---------------------------------------------------------------------------

    \115\ The hazardous waste heating values of liquid fuel boilers 
range from 2,200 to 21,000 BTU/lb, with a median value of 14,800. 
Heating values of lightweight aggregate kilns range from 4,900 to 
16,900 BTU/lb, with a median value of 14,800. We note that the low 
end heating value for lightweight aggregate kilns reflects one 
source and is not typical of heating values used by the other 
commercial lightweight aggregate kiln facilities, and are similar to 
the heating values of cement kilns.
---------------------------------------------------------------------------

    One commenter's apparent concern with thermal emissions seems to 
center on an assertion that sources will intentionally blend 
nonhazardous, high heating value wastes or fuels with low energy, high 
metal bearing hazardous wastes in order to increase the energy content 
of these metal bearing wastes so that they will be subject to higher 
allowable emissions via thermal emission standards. We specifically 
address that comment later as it relates to commercial energy recovery 
units (lightweight aggregate kilns and cement kilns). We note here, 
however, that we do not consider that comment to be of practical 
concern for liquid fuel boilers

[[Page 59455]]

because they do not engage in commercial fuel blending practices.
    Comment: A commenter states that EPA's assessment of thermal 
emissions to identify the relevant best sources is inappropriate 
because thermal emissions are not emission levels, but rather a ratio 
of emissions to the heat content in a source's hazardous waste.
    Response: This comment challenges the basic idea of normalization, 
since the comment would be the same regardless of the normalizing 
parameter being used. Thermal emissions are emission levels that are 
normalized to account for the amount of energy (i.e., raw material) 
these sources recover by processing hazardous waste. Similarly, a mass 
emission concentration (i.e., [mu]g/dscm) is a ratio of the emissions 
to the volume of combustion gas that is generated, which normalize 
emissions to account for differences in the size of the combustion 
units (as well as differences in production capacity). This rulemaking 
assesses performance and expresses emission standards in both of these 
formats; both formats normalize the emissions so that we may better 
assess emission control efficiencies equally across sources based on 
the percent of HAP in the feed (whether thermal feed or feed normalized 
based on combustor size) \116\ that is controlled or removed from the 
stack gas prior to being emitted into the atmosphere. As discussed 
above, technology-based standards have historically assessed 
performance after normalizing emissions based on the amount of raw 
material processed by the given industry sector. Thermal emissions 
normalize each source's emissions based on the amount of raw material 
(hazardous waste fuel) it processes, and are therefore appropriate to 
assess and identify the relevant best performers. Finally, as 
previously explained, this approach is consistent with both the 
language of section 112 (d) (2) and (3), and the purpose of these 
provisions.
---------------------------------------------------------------------------

    \116\ For emission concentration-based standards we normalize 
hazardous waste feed control levels by calculating what we call 
maximum theoretical emission concentrations, which are equivalent to 
the HAP mass feed rate divided by gas flow rate.
---------------------------------------------------------------------------

    Comment: A commenter states that EPA's assessment of thermal 
emissions to identify the relevant best sources is inappropriate 
because it ignores HAP emissions attributable to the nonhazardous fuel 
and raw material.
    Response: Thermal emission standards do not directly control HAP 
emissions attributable to the fossil fuels and raw material, in the 
sense that we did not assess feed control of fossil fuels or raw 
materials. However, this issue is not related to our choice to use 
thermal content of hazardous waste as a normalizing parameter. Rather, 
the issue is whether feed control of fossil fuels and raw materials is 
a feasible means of control at all. We have determined that it is not, 
and that only back-end control (expressed as system removal efficiency) 
is feasible. Moreover, today's rule controls emissions from HAP in raw 
material and fossil fuels. All non-mercury metal HAP emissions 
attributable to fossil fuels or raw material are effectively and 
efficiently controlled to the level of the average of the best 
performing sources with the surrogate particulate matter standard, as 
well as the system removal efficiency component of the SRE/Feed 
methodology.
    Comment: EPA has failed to document sources' actual feedrates. 
Feedrates are presented either as MTECs (where hazardous waste HAP 
feedrates are divided by gas flow rates) or as thermal feedrates, 
(where feedrate is expressed as the mass of HAP per million BTUs of 
hazardous waste fired). This is impermissible, since it does not 
measure actual feed levels.
    Response: This comment essentially takes the position that it is 
legally impermissible to normalize standards, i.e., express standards 
on a common basis. EPA rejects this comment for the reasons stated in 
the introduction to this section.
    Comment: A commenter states that an increasing number of fuel 
blenders are producing fuels with a minimum heating content and maximum 
metals content in order to maximize revenues because high metal bearing 
wastes command a higher revenue on the commercial waste market. The 
commenter states that thermal emission standards are not appropriate 
because they are based on the implicit assumption that energy recovery 
entails metals feed.
    Response: Contrary to what the commenter suggests, the thermal 
emissions format will more likely discourage the alleged practice of 
fuel blenders producing fuels with a minimum heat content and maximum 
metals content because the standard limits the allowable metal 
emissions based on the amount of energy contained in the hazardous 
waste. Thus, a source with a lower energy waste would have to ensure 
that the mass concentration of metals is also lower to comply with the 
thermal emission formatted standard. The source would consequently emit 
less metals (on a mass basis) because of the lower metal mass 
concentration in the waste fuel. Thermal emission standards reflect the 
reality that the hazardous waste fuels that are currently processed 
safely and efficiently in energy recovery units to displace valuable 
fossil fuel do in fact contain metal HAP. From a feed control 
perspective, the thermal emissions format appropriately requires 
sources to process high energy content hazardous waste fuels that 
reflect the thermal feed control levels achieved by the average of the 
best performing sources, and does so equally for all sources because it 
normalizes the allowable emissions based on the amount of energy each 
source recovers from the hazardous waste.
    Comment: A commenter states that EPA should be concerned that fuel 
blenders and kilns will use the thermal emission standard format to 
increase the allowable metals feedrates for their units. The commenter 
claims that sources could inappropriately convert non-hazardous waste 
fuel to hazardous waste fuel by simply putting coal in a bunker in 
which hazardous waste was once stored, or mixing nonhazardous waste 
fuel oil with hazardous waste. The commenter states that a facility 
with a low hazardous waste firing rate, and relatively low allowable 
emissions can become a facility with a high hazardous waste percent 
firing rate, with higher allowable emissions, simply by `creative' use 
of the hazardous waste mixture rule. The commenter suggests that EPA 
clearly state that the hazardous waste thermal emission standards apply 
only to the hazardous waste portion of the fuel blend mixture. The 
commenter further suggests that EPA require fuel blenders to report the 
amount of nonhazardous waste fuel that is contained in the fuel blend, 
and that cement kilns use this to determine allowable metal feed rates 
based on the original hazardous waste energy content.
    Response: We do not believe hazardous waste combustors will engage 
in the practice of redesignating their fossil fuels, i.e., coal, as 
hazardous wastes with creative use of the mixture rule in order to 
increase their allowable metal HAP emission rate. That would require 
large quantities of coal to be newly classified as hazardous waste. The 
coal, and the unit where the coal is stored, would subsequently become 
subject to all applicable subtitle C requirements, which include 
storage and closure/post closure requirements. We believe this 
disincentive will discourage this hypothetical practice.
    Moreover, as previously discussed, today's rule does not allow 
cement kiln or lightweight aggregate kiln emissions to exceed the 
interim standards. The fact that we are issuing emission

[[Page 59456]]

standards for some pollutants in the thermal emissions standard format 
will not encourage fuel blenders to send more metals to these 
commercial energy recovery sources because their allowable emission 
concentrations are, by definition, either equivalent to or more 
stringent than the current limitations with which they are complying. 
Thus, even if the fuel blenders and energy recovery units engaged in 
this practice, they could not emit more metals than they are currently 
allowed to emit. We therefore conclude that it is not necessary to 
promulgate complicated regulatory provisions that would increase the 
reporting and recordkeeping requirements of fuel blenders and energy 
recovery units in order to address a hypothetical scenario that likely 
would never occur.
    Finally, we note that combustion of certain high HAP metal content 
wastes is already prohibited under RCRA rules. See 40 CFR 268.3. Such 
wastes remain prohibited from combustion even if they are mixed with 
fossil fuel so that the mixture has a higher energy content. U.S. v. 
Marine Shale Processors, 81 F. 3d 1361, 1366 (5th Cir. 1996) (an 
unrecyclable hazardous waste is not recycled when it is mixed with a 
usable non-waste and the mixture is processed). Thus, the dilution 
prohibition in Sec.  268.3 serves as a further guard against the 
commenter's concern.
    Comment: A commenter states that the thermal emissions format may 
be problematic because it is based on a flawed assumption that metal 
HAP from the cement kiln raw material and hazardous waste partition in 
equal proportions to the total stack gas emissions. The commenter 
believes that metal retention in the raw materials is higher than the 
hazardous waste, suggesting that thermal emission standards allow an 
arbitrary increase in allowable hazardous waste metals emissions. The 
commenter suggests that EPA require that compliance demonstrations be 
conducted only under conditions where the metals content in the 
hazardous waste is significantly higher than the metal content in the 
raw material to minimize this bias.
    Response: The commenter has not provided any emissions data to 
support this claim, nor does the EPA know of data available that 
reaches this conclusion. We do not believe there is a significant 
difference in the partitioning rates of these metals in a cement 
kiln.\117\ Even if there is a difference, this would not result in an 
arbitrary increase of allowable hazardous waste metals emissions. The 
thermal emission standards were calculated using thermal emissions data 
that are based on each source's compliance test. These tests were 
conducted at hazardous waste feed control levels that represented the 
upper bound of feed control levels these sources see on a day-to-day 
basis. To accomplish this, sources spiked metals into the hazardous 
waste prior to combusting the wastes. The amount of metals that were 
contained in the hazardous waste streams, after accounting for these 
spiked metals, far exceeded the metal levels that were contained in the 
raw material. Thus the differences in partitioning, if any, would 
likely be overshadowed by the fact that the majority of the metals were 
contained in the hazardous waste.
---------------------------------------------------------------------------

    \117\ We reference comments submitted by the cement kiln 
recycling coalition that address this very point. See USEPA, 
``Comment Response Document to the Proposed HWC MACT Standards, 
Volume 1: MACT Standards,'' September 2005, Section 3.3. We have 
evaluated these comments and find them persuasive on this issue.
---------------------------------------------------------------------------

    Notably, any partitioning bias that that may be present would also 
have been present during these compliance tests. As a result, this 
potential bias would be built into the emission standard and thus would 
not result in an arbitrary increase in allowable hazardous waste metals 
emissions because these sources will again demonstrate compliance under 
testing conditions similar to those used to generate the data used to 
calculate the MACT floors. We conclude that it is not necessary to 
provide additional prescriptive regulatory language that would require 
sources to demonstrate system removal efficiencies under testing 
conditions that exhibit a high ratio of hazardous waste metal content 
to raw material metal content because the regulations implicitly 
require sources to demonstrate hazardous waste metal feed control 
levels that represent the upper range of their allowable feed control 
levels.\118\
---------------------------------------------------------------------------

    \118\ Although today's final rule allows sources to extrapolate 
their allowable hazardous waste feed control levels to levels that 
are higher than the level demonstrated in the comprehensive 
performance test, sources must still spike metals into the hazardous 
waste during the test in order to assure that the system removal 
efficiency used for the extrapolation procedure is reliable and 
accurate.
---------------------------------------------------------------------------

    Comment: A commenter states that compliance with standards 
expressed in a thermal emissions format is problematic because the 
measurement of energy content of hazardous waste fuel blends is subject 
to significant variability due to the nature of the test. The commenter 
also claims that heating value measurements of waste streams that are 
mixtures of solids and liquids tend be biased high, which would 
inappropriately give these sources higher allowable metal emission 
limitation.
    Response: There are standard ASTM procedures that reliably measure 
the energy content of the hazardous waste. Any parameter that is 
measured for compliance purposes is subject to method imprecision and 
variability. We do not believe that hazardous waste energy content 
measurements result in imprecision and variability above and beyond the 
measurement methods that are currently used to assure compliance with 
emission concentration-based standards.
    The commenter did not provide evidence that supports the claim that 
energy content measurement and/or sampling methods consistently result 
in a positive bias. If a bias were consistently present for these types 
of wastes, then one would expect it to be also reflected in the 
measured data for which we based the emission standards, which would 
fully address the commenter's concern. Nonetheless, we note that all 
hazardous waste sampling and analysis procedures must be prescribed in 
each source's feedstream analysis plan, which can be reviewed by the 
permitting authority upon request. These feedstream analysis plans must 
ensure that sampling and analysis procedures are unbiased, precise, and 
that the results are representative of the feedstream. See Sec.  
63.1208(b)(8). More information on obtaining a representative samples 
can be found in EPA's SW-846 publication.\119\ These procedures involve 
acquiring several sub-samples that provide integration over the 
breadth, depth and surface area of the waste container and obtaining 
replicate samples (see Ch. 13.3.1 of SW-846).
---------------------------------------------------------------------------

    \119\ SW-846, ``Test Methods for Evaluating Solid Waste, 
Physical/Chemical Methods.''
---------------------------------------------------------------------------

    Comment: A commenter states that BTU measurements can be reported 
as either a higher heating value or a lower heating value, and suggests 
that EPA require sources to use the lower heating value calculation 
when determining allowable hazardous waste feed control levels. The 
commenter seems to imply that use of higher heating values will 
inappropriately result in higher allowable metal feed rates for fuel 
blends that contain aqueous waste.
    Response: The BTU data in our database that we use to calculate the 
emission standards reflect higher heating values. It is standard 
practice in the incineration/combustion industry to report the gross 
heat of combustion (or

[[Page 59457]]

higher heating value). We conclude that sources should use the higher 
heating value rather than the lower heating value for all compliance 
determinations because these are method-based emission standards. Fuel 
blends that contain aqueous wastes will not be inappropriately rewarded 
with higher allowable feed rates because any fuel mixture that contain 
aqueous mixtures will have lower reported heating values, irrespective 
of whether they are reported as higher heating values or lower heating 
values.\120\
---------------------------------------------------------------------------

    \120\ The difference between the higher heating value and lower 
heating value of an aqueous waste is insignificant relative to the 
difference in heating value between an aqueous waste and an organic 
liquid waste fuel.
---------------------------------------------------------------------------

E. Standards Can Be No Less Stringent Than the Interim Standards

    Comment: Several commenters oppose EPA's position in the proposed 
rule that the replacement standards can be promulgated at a level no 
less stringent than the interim standards for incinerators, cement 
kilns, and lightweight aggregate kilns. In instances where the 
calculated replacement standard is less stringent than the interim 
standard, the commenters oppose EPA's position of ``capping'' the 
replacement standard at the level of the interim standard to prevent 
backsliding from those levels. Instead, commenters recommend that EPA 
calculate and finalize the existing and new source floor levels without 
regard to the interim standards. One commenter also notes that the 
interim standards are simply a placeholder without the necessary 
statutory basis to qualify as emission limitations for purposes of 
establishing MACT floors. Another commenter, however, supports EPA's 
position to prevent backsliding to levels less stringent than the 
interim standards.
    Response: We maintain that the replacement standards can be no less 
stringent than existing standards, including the interim standards 
under Sec. Sec.  63.1203-1205, for incinerators, cement kilns, and 
lightweight aggregate kilns. These standards were promulgated on 
February 13, 2002, and sources were required to comply with them no 
later than September 30, 2003, unless granted a one-year extension (see 
Sec.  63.1206(a)). Thus, all hazardous waste combustors are currently 
complying with the interim standards. The comment that the standards 
lack some type of requisite statutory pedigree misses the central point 
of our interpretation of the statute: motivation for achieving a 
standard (be it regulatory compulsion, statutory requirement, or some 
other reason) is irrelevant in determining levels of MACT floors. 
National Lime v. EPA, 233 F. 3d at 640. What matters is the level of 
performance, not what motivated that level.
    As a result, the replacement standards promulgated today ensure 
that sources will emit HAP at levels no higher than levels achieved 
under current regulations. We do this in this rule, when necessary, by 
either capping a calculated floor level by the interim standard (when 
both the calculated floor level and interim standard are expressed in 
the same format of the standard) or by adopting dual standards in cases 
where formats of the standard vary (so that comparison of stringency 
cannot be uniformly determined (as for cement kilns and lightweight 
aggregate kilns, as explained in the preceding section above and in the 
following response). In this case, the sources are subject to both the 
replacement and interim standards.
    Comment: One commenter states that some proposed standards 
expressed in a thermal emissions format would allow some sources to 
emit semivolatile metals at levels higher than the interim standard. 
The commenter states that EPA reached incorrect conclusions when making 
relative stringency comparisons between standards expressed in a 
thermal emissions and mass concentrations format because, in part, EPA 
assumed an average F-factor (e.g., semivolatile metals for cement 
kilns).\121\ In addition, the commenter notes that the actual 
relationship between standards expressed in terms of thermal emissions 
and mass concentrations is complex and depends on a number of factors. 
As a result, the commenter urges EPA to adopt dual standards (i.e., 
promulgate the MACT standard as both the standard expressed in a 
thermal emissions format and also the interim standard expressed in a 
mass concentration format) to prevent backsliding.
---------------------------------------------------------------------------

    \121\ An F-factor is an estimate of the amount of combustion gas 
volume that is generated per fuel heat input for a given type of 
fuel, expressed in units, for example, cubic feet of combustion gas 
per million British thermal units (BTU) of fuel burned. In the 
proposal, EPA used F-factors to convert the emission standards 
expressed on a thermal basis to mass concentrations in order to make 
a judgment as to the relative stringency of the proposed MACT 
standards relative to the interim standards.
---------------------------------------------------------------------------

    Response: Even though a source may operate in compliance with a 
standard expressed in a thermal emission format, a source may or may 
not also be in compliance with the corresponding mass concentration 
interim standard (e.g., the semi- and low volatile metal emission 
standards for cement and lightweight aggregate kilns of Sec. Sec.  
63.1204 and 63.1205, respectively). As reflected in the comment, making 
a judgment as to whether a replacement standard is more stringent than 
the interim standard for the HAP is not always a straight-forward 
calculation. As we discussed in the proposed rule \122\ and echoed by 
the commenter, comparing standards in the thermal emissions format to 
those in a mass concentration format involves assumptions that vary on 
a site-specific basis and can vary over time, including the hazardous 
waste fuel replacement rate, contributions to emissions from 
nonhazardous waste inputs such as raw materials and nonhazardous waste 
fuels such as coal, how close to the standard a source elects to 
comply, the system removal efficiency demonstrated during testing, and 
the type and composition, including heating value, of fuels burned.
---------------------------------------------------------------------------

    \122\ For example, see 69 FR at 21255-258, 267-271.
---------------------------------------------------------------------------

    To ensure that sources operating under standards expressed in a 
thermal emissions format will not emit HAP metals at levels higher than 
currently achieved under the interim standards, we adopt a dual 
standard to prevent emissions increasing to levels higher than the 
interim standards. The dual standard structure includes both the 
standard expressed in a thermal emissions format and the interim 
standard, which is expressed in a mass concentration format. We apply 
this concept to several standards including semivolatile metals, low 
volatile metals, and mercury \123\ for cement kilns and semivolatile 
metals and low volatile metals for lightweight aggregate kilns. This 
approach ensures that sources are not emitting HAP metals above the 
levels of the interim standards because we cannot reliably determine 
that emissions under a standard expressed in a thermal emissions format 
would not exceed the interim standard for all sources in the category. 
See Sec. Sec.  63.1220(a)(2)-(a)(4), and (b)(2)-(b)(4) and 
63.1221(a)(3)-(a)(4) and (b)(3)-(b)(4).
---------------------------------------------------------------------------

    \123\ Although the mercury standard promulgated for cement kilns 
is not expressed using a thermal emission format basis, the same 
concept applies because the mercury standard is a hazardous waste 
feed concentration standard, which is a different format than the 
interim standard.
---------------------------------------------------------------------------

    We evaluated the relative stringency of the standards expressed in 
the thermal emissions format compared to the interim standards for the 
entire source category in order to determine if the dual standard 
scheme could be avoided. We determined that we could not. For some HAP 
groups we found that many sources in the category would have the 
potential to exceed the interim

[[Page 59458]]

standards for that HAP.\124\ In this case, we considered simply 
``capping'' the standard expressed in the thermal emission format by 
the interim standard (i.e., the promulgated standard would only be 
expressed in a mass concentration format). However, we conclude that 
this approach would not be appropriate because the standard expressed 
in a thermal emission format would likely be more stringent than the 
mass concentration for some sources, and the statute requires that MACT 
floors reflect this superior level of performance.
---------------------------------------------------------------------------

    \124\ An example for each category is semivolatile metals 
thermal emissions standard for existing cement and lightweight 
aggregate kilns. See USEPA, ``Final Technical Support Document for 
the HWC MACT Standards, Volume III: Selection of MACT Standards,'' 
Section 23.1, September 2005.
---------------------------------------------------------------------------

    In other cases we found that the standards expressed in the thermal 
emissions format would not likely exceed the interim standards by the 
majority of sources operating under typical conditions.\125\ While our 
analysis (based on information in our data base) shows in these cases 
that the emission standard expressed in a thermal emission format would 
not likely result in an exceedance of the interim standard, this 
conclusion may not be true because the assumptions may not be valid for 
a particular source or site-specific factors may change in future 
operations. For example, HAP metal emissions could increase over time 
due to increases in HAP contributions from raw materials or alternative 
raw materials. Given this potential, we adopt dual standards for the 
HAP metal standards in order to ensure that standards expressed in a 
thermal emissions format will not exceed emission levels achieved under 
the interim standards.\126\
---------------------------------------------------------------------------

    \125\ An example is the emission standards for low volatile 
metals for existing and new cement kilns and new lightweight 
aggregate kilns. See USEPA, ``Final Technical Support Document for 
the HWC MACT Standards, Volume III: Selection of MACT Standards,'' 
Section 23.1, September 2005.
    \126\ In response to a comment regarding the implementation of 
dual standards, we note the promulgation of a new provision allowing 
sources to petition the Administrator to waive the HAP metal 
feedrate operating parameter limits for either the emissions 
standards expressed in a thermal emissions format (or the mercury 
feed concentration standard for cement kilns) or the interim 
standards based on documentation that the feedrate operating 
parameter limit is not needed to ensure compliance with the relevant 
standard on a continuous basis. See new Sec.  63.1209(g)(1)(iv) and 
Comment Response Document, Volume I, Section 3.5.
---------------------------------------------------------------------------

    Comment: Several commenters state that the interim standards do not 
reflect the average performance of the best sources, and so cannot be 
the basis for floor levels.
    Response: In those few situations where we have established floor 
levels at the level of the interim standards, we have done so as the 
best means of estimating performance of the best performing sources. 
Based on the available data to us, the average of the best performing 
sources exceeds the level of the interim standards in a few instances. 
Under these circumstances, the binding regulatory limit becomes the 
best means available to us to estimate performance. See Mossville, 370 
F. 3d at 1241-42 (accepting regulatory level as a floor standard where 
sources' measured performance is not a valid means of determining floor 
levels, and where such data contains results as high as those 
regulatory levels).

F. How Can EPA's Approach to Assessing Variability and its Ranking 
Methodologies Be Reasonable When They Result in Standards Higher Than 
the Interim Standards?

    A commenter argued that EPA's floor methodologies, in particular 
its consideration of variability beyond that demonstrated in single 
test conditions, the SRE/feed and Air Pollution Control Device 
methodologies, must be arbitrary because in a few instances projected 
standards using these approaches were higher than the current interim 
standards, a level every source (not just the best performers) are 
achieving. Commenters also noted that one of the new source standards 
calculated under these approaches was higher than an existing source 
standard, another arbitrary result.
    EPA believes that these seeming anomalies (which are infrequent) 
result from the database used to calculate performance and standards, 
rather than from the approaches to assessing variability or the two 
questioned floor methodologies. The data base is from test results 
which preceded EPA's adoption of the interim standards. Thus, the level 
of performance required by the later rule is not necessarily reflected 
in pre-rule test data. In confirmation, some of the standards computed 
using straight emission approaches also are higher than the interim 
standards. Other anomalies arise simply due to scarcity of data (floor 
levels for certain HAP emitted by lightweight aggregate kilns 
especially, where there are only nine sources total). In these 
situations there is a greater likelihood that one or more of the best 
performing sources will have relatively high emissions because we are 
required to use data from five sources to comprise the MACT pool 
whenever we have data from fewer than 30 sources, and a small amount of 
data can skew the result. See Sec.  112(d)(3)(B).\127\
---------------------------------------------------------------------------

    \127\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' September 
2005, Section 19, for further discussion.
---------------------------------------------------------------------------

    For example, many of the calculated new source chlorine floors were 
slightly higher than the calculated existing source standards because 
we assumed all sources with measured emissions below 20 ppmv were in 
fact emitting at 20 ppmv (see part four, section I.C). We generally are 
unable to differentiate a single best performing source among these 
best performers because many/all of the best performing sources 
emissions are adjusted to the same emission level. The calculated new 
source floor can be slightly higher than the existing source floor 
because the variability factor that is applied to the single best 
performing source is based on only one test condition (with three 
emission test runs). This results in a higher level of uncertainty 
relative to the existing source standard, which is based on a 
compilation of emissions data from several sources that have 
essentially the same projected emissions as a result of the method bias 
correction factor. The variability factor that is applied to the 
emissions of the single best performing source is therefore higher than 
the variability factor for the existing source floor because there are 
fewer degrees of freedom in the statistical analysis.\128\ Likewise, 
many of the calculated solid fuel boiler new source standards were 
slightly higher than the calculated existing source standards because, 
as discussed above, there are fewer degrees of freedom when assessing 
the variability from a single best performing source. The solid fuel 
boiler ``anomalies'' also occur using a straight emissions methodology. 
See USEPA, ``Technical Support Document for the HWC MACT Standards, 
Volume III: Selection of MACT Standards,'' September, 2005, Section 19, 
for further discussion that summarizes and explains these so-called 
anomalies.
---------------------------------------------------------------------------

    \128\ For a single test condition the t factor used in 
variability factor calculation has n-1 degrees of freedom where n is 
the number of runs for that condition. For the MACT floor 
calculation the t factor has X-N degrees of freedom where X is the 
total number of runs from all sources in the MACT pool and N is the 
number of sources in the pool. See USEPA, ``Technical Support 
Document for the HWC MACT Standards, Volume III: Selection of MACT 
Standards,'' September, 2005, Section 7.1 for more information on 
the floor calculation procedure.

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[[Page 59459]]

IV. Use of Surrogates

A. Particulate Matter as Surrogate for Metal HAP

    Comment: A commenter states that EPA's use of particulate matter as 
a surrogate for nonenumerated metals is unlawful and arbitrary and 
capricious because although particulate matter emissions may provide 
some indication of how good a source's end-of stack control of such 
metals is, it does not indicate what its actual metal emission levels 
are.\129\ The commenter states that emissions of these metals can vary 
based on metal feed rate without having any appreciable effect on 
particulate matter emission levels. Thus a particulate matter standard 
does not necessarily ensure that metal emissions are reduced to the 
metal emission levels achieved by the relevant best performing sources. 
To support this assertion, the commenter states that EPA is on record 
saying ``low particulate matter emissions do not necessarily guarantee 
low metal HAP emissions, especially in instances where the hazardous 
waste feeds are highly concentrated with metal HAP.'' 69 FR at 21221.
---------------------------------------------------------------------------

    \129\ ``Enumerated'' metals are those HAP metals directly 
controlled with an emission limit, i.e., lead, cadmium, chromium, 
arsenic and beryllium. The remaining nonmercury metal HAP (i.e., 
antimony, cobalt, manganese, nickel, and selenium) are called 
``nonenumerated'' metal HAP (note that arsenic and berrylium are 
nonenumerated metals for liquid fuel boilers because the low 
volatile metal emission standard applies only to chrome).
---------------------------------------------------------------------------

    Response: The final rule uses a particulate matter standard as a 
surrogate to control: (1) Emissions of nonenumerated metals that are 
attributable to all feedstreams (both hazardous waste and remaining 
inputs); and (2) all nonmercury metal HAP emissions (both enumerated 
and nonenumerated metal HAP) from the nonhazardous waste process feeds 
at cement kilns, lightweight aggregate kilns, and liquid fuel boilers 
(e.g., emissions attributable to coal and raw material at a cement 
kiln, and emissions attributable to fuel oil for liquid fuel boilers). 
Incinerators, liquid and solid fuel boilers may elect to comply with an 
alternative to the particulate matter standard that would limit 
emissions of all the semivolatile metal HAPs and low volatile metal 
HAPs. See Sec.  63.1219(e).
    The particulate matter standard is a necessary, effective, and 
appropriate surrogate to control nonmercury metal HAPs. The record 
demonstrates overwhelmingly that when a hazardous waste combustor emits 
particulate matter, it also emits nonmercury HAP metals as part of that 
particulate matter, and that when particulate matter is removed from 
emissions the nonmercury HAP metals are removed with it.\130\ 
Nonmercury metal HAP emissions are therefore reduced whenever 
particulate matter emissions are reduced. The particulate matter 
standard thus is an effective and appropriate surrogate that assures 
sources are controlling these metal HAP with an appropriate back-end 
control technology. National Lime v. EPA, 233 F. 3d at 639. The 
nonenumerated metal HAP are no different than other semivolatile or low 
volatile metals in that they also will be effectively controlled with a 
back-end particulate matter air pollution control device.
---------------------------------------------------------------------------

    \130\ This statement is equally true for any emitting source, 
not just hazardous waste combustors. It is well established that 
semivolatile and low volatile metals exist in solid particulate form 
at typical air pollution control device operating temperatures. This 
is supported by (1) known operating temperature ranges of air 
pollution control devices used by hazardous waste combustors; (2) 
known metal volatility equilibrium relationships; and (3) extensive 
technical literature. See USEPA, ``Technical Support Document for 
the HWC MACT Standards, Volume III: Selection of MACT Standards,'' 
September 2005, Section 3.1.
---------------------------------------------------------------------------

    We also considered the possibility of developing a standard for 
nonenumerated HAP metals instead of a PM standard (i.e., regulating 
these metals directly, rather than through use of a surrogate). We 
conclude for several reasons, however, that issuing emission standards 
for these nonenumerated metals in lieu of a particulate matter standard 
would not adequately control nonmercury metal HAPs to levels achieved 
by the relevant best performing sources.
    We generally lack sufficient compliance test emissions data for the 
noneneumerated metals to assess the relevant best performing sources, 
because, as discussed below, most of these metals were not directly 
regulated pursuant to RCRA air emission standards.\131\ Although we 
have more emissions data for these metals that are based on (so called) 
normal operations, we still lack sufficient emissions data to establish 
nonenumerated metal standards for all the source categories. Use of 
normal data may also be problematic because of the concern raised by 
the cement kiln and lightweight aggregate kiln stakeholders that our 
normal metals emissions data obtained from compliance tests are not 
representative of the range of actual emissions at their sources. 
Cement kiln and lightweight aggregate kiln stakeholders submitted long-
term hazardous waste mercury feed control data that support their 
assertion. Although these stakeholders did not submit long-term normal 
hazardous waste feed control data for the nonenumerated metals, we can 
still see that use of the normal nonenumerated metal snapshot emissions 
in our database to determine MACT floors could raise similar concerns 
with respect to whether the normal data in fact represents average 
emissions at these sources, and their level of performance.
---------------------------------------------------------------------------

    \131\ At best, we may have enough compliance test data for 
antimony and selenium to adequately assess relevant best performers 
for only incinerators and lightweight aggregate kilns.
---------------------------------------------------------------------------

    Use of particulate matter emissions data to assess the relevant 
best performers for nonenumerated metal HAP is therefore more 
appropriate for two reasons. Compliance test data better account for 
emissions variability and avoid the normal emissions bias discussed 
above. We also have much more particulate matter emissions data from 
more sources, which better allows us to evaluate the true range of 
emissions from all the sources within the source category and to assess 
and identify the relevant top performing 12 percent of the sources.
    It would be inappropriate to assess total stack gas emissions of 
nonenumerated metals for cement kiln and lightweight aggregate kilns 
when determining the relevant best performers because these emissions 
would, in part, reflect the metal feed levels in these sources' 
nonhazardous waste process feedstreams. This is not appropriate because 
nonhazardous process feedstream control is not a feasible means of 
control. See part four, section III.B.1. A potential solution to this 
problem would be to identify the relevant best performers by assessing 
each source's hazardous waste thermal emissions for these nonenumerated 
metals (given that hazardous waste thermal emissions exclude by 
definition emissions attributable to inputs other than hazardous waste, 
i.e. raw materials and fossil fuels). This, however, would be 
problematic because, aside from the data limitation issues, the 
majority of the nonenumerated metals data reflect normal emissions 
which often do not contain the highest feed rates used by the source. 
As a result, we cannot assess performance on a thermal emissions basis 
because of the uncertainty associated with system removal efficiencies 
at such low metal feedrates. Furthermore, even if we could issue 
hazardous waste thermal emissions standards for these metals, a 
particulate matter emission standard would still be necessary to 
control nonmercury metal HAP emissions from the nonhazardous waste 
process feedstreams.

[[Page 59460]]

    Emission standards for these nonenumerated metals could require 
sources to implement hazardous waste feed control (for these metals) to 
comply with the standard.\132\ We are less assured that these sources 
were implementing hazardous waste feed control for these nonenumerated 
metals at the time they conducted the emissions tests (which serve as 
the basis for floor calculations) because most of these metals were 
never directly regulated pursuant to the RCRA emission standards.\133\ 
This means that sources tended to optimize (or at least concentrate 
their efforts on) control of the metals that are regulated. Although 
these metals were being controlled with each source's back-end control 
device, sources may not have been controlling these metal feedrates 
because they probably were not subject to specific feedrate limitations 
(feed control of the enumerated metal HAP does not ensure feed control 
of these nonenumerated metal HAP). Furthermore, simultaneous feed 
control of all these metals, when combined with enumerated semivolatile 
and low volatile metals, may not be possible because the best 
performing sources for all these metals may collectively represent a 
hazardous waste feedstream that does not exist in practice (from a 
combined metal concentration perspective) because there likely would be 
different best performers for each of the metal HAP or metal HAP 
groups.\134\ We thus conclude that back-end control as measured and 
assessed by each source's particulate matter emissions is the 
appropriate floor technology to assess when identifying the relevant 
best performers for nonenumerated HAP metals and estimating these 
sources' level of performance.
---------------------------------------------------------------------------

    \132\ Sources that otherwise would be equipped with what is 
considered to be a MACT back-end control devices (i.e., a control 
device achieving the final rule particulate matter standard) may not 
be able to achieve these metal emissions standards due to varying 
metal feed levels (both within sources and across sources). Such an 
outcome may require a source to limit the amount of metal that is 
fed into the combustion unit to achieve the standard.
    \133\ Antimony is the only nonenumerated metal that is directly 
regulated pursuant to the boilers and industrial furnace 
regulations. See Sec.  266.106.
    \134\ We generally cannot combine these nonenumerated metals 
into the associated semivoltile or low volatile metal volatility 
groupings promulgated in this final rule for purposes of 
establishing ``grouped'' emission standards because we cannot mix 
compliance test data with normal emissions data when calculating 
floors (the majority of the standards included in this final rule 
are based on compliance test data, and the majority of the data we 
have for nonenumerated metals being normal). Furthermore, if we were 
to separately group the normal nonenumerated metal emission data 
into their associated semivolatile or low volatile metal group, we 
may encounter data limitation issues because each source would need 
to have measured each of the nonenumerated metals in that associated 
metal volatility group in order for us to conclude that the emission 
data adequately represents the sources combined emissions of 
semivolatile or low volatile metals.
---------------------------------------------------------------------------

    Comment: A commenter states that EPA's rationale for use of 
particulate matter as a surrogate for nonenumerated metals is flawed 
because EPA has provided no data in the proposal to justify its 
hypothesis that particulate matter is an appropriate surrogate for non-
enumerated metal HAP. The commenter also states that the proposed 
emission standards for particulate matter for existing sources 
discriminate against boilers and process heaters that burn clean (i.e., 
little or very low concentrations of HAP metals) hazardous waste fuels. 
The commenter suggests that if there are sufficient data, EPA should 
consider developing an alternative emission standard for total HAP 
metals for new and existing liquid fuel boilers, as was done for the 
Subpart DDDDD National Emission Standards for Hazardous Air Pollutants 
for Industrial/Commercial/Institutional Boilers and Process Heaters.
    Response: As previously discussed in this section, particulate 
matter reflects emissions of nonmercury metal HAPs because these 
compounds comprise a percentage of the particulate matter (provided 
these metals are fed into the combustion unit). The technologies that 
have been developed and implemented to control particulate matter also 
control nonmercury metal HAP. Since non-mercury metal HAP is a 
component of particulate matter, we can use particulate matter as a 
surrogate for these metals. Further justification for the use of 
particulate matter as a surrogate to control metal HAP is included in 
the technical support document.\135\
---------------------------------------------------------------------------

    \135\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' September 
2005, Section 3.1.
---------------------------------------------------------------------------

    We conclude that we do not have enough nonenumerated metal 
emissions data to calculate alternative total metal emission floors for 
liquid fuel boilers. The most problematic of these metals are manganese 
and cobalt, where we have emission data from only three sources. We 
have much more compliance test particulate matter emissions data from 
liquid fuel boilers, and thus conclude that the particulate matter 
standard best reflects the emission levels achieved by the relevant 
best performers.
    Similar to the above discussion, calculating an alternative total 
metal emissions floor raises questions regarding the method used to 
calculate such floors. Hazardous waste combustor metal emissions have 
traditionally been regulated in volatility groupings because the 
volatility of the metal affects the efficiency of back-end control 
(i.e., semivolatile metals are more difficult to control than low 
volatile metals because they volatilize in the combustor and then 
condense as small particulates prior to or in the emission control 
device). When identifying the best performing sources, we previously 
have, in general, only evaluated sources that have metal emissions 
information for every metal in the volatility grouping. This approach 
could prove to be problematic since it is not likely many sources will 
have emissions data for all the metals.
    Although we could not calculate alternative total metal emission 
floor standards based on the available emissions data we have, we agree 
with the commenters' view that sources that burn hazardous waste fuels 
with low levels of nonenumerated metals should be allowed to comply 
with a metals standard rather than the particulate matter standard. We 
proposed an alternative to the particulate matter standard (see 69 FR 
at 21331) for incinerators, liquid, and solid fuel boilers that was a 
simplified version of the alternative particulate matter standard that 
is currently in effect for incinerators pursuant to the interim 
standards (see Sec.  63.1206(b)(14)). We received no adverse comment 
and are promulgating this alternative as proposed. The alternative 
metal standards apply to both enumerated and nonenumerated metal HAP, 
excluding mercury. For purposes of these alternative requirements, each 
nonenumerated metal is classified as either a semivolatile or a low 
volatile metal and subsequently grouped with the associated 
semivolatile and low volatile enumerated metals. The semivolatile and 
low volatile metals standards under this alternative are the same as 
those that apply to other liquid fuel boilers, but the standard would 
apply to all metal HAP, not just those enumerated in the generic low 
volatile metal and semivolatile metal standards. See Sec. Sec.  Sec.  
63.1216(e), 63.1217(e) and 63.1219(e).

B. Carbon Monoxide/Hydrocarbons and DRE as Surrogates for Dioxin/Furan

    Comment: One commenter states that the dioxin/furan floors for new 
and existing solid fuel boilers is unlawful and arbitrary and 
capricious. EPA established the floor for dioxin/furan for these 
sources as compliance with the carbon monoxide or hydrocarbon standard 
and the destruction and removal efficiency (DRE) standard. The

[[Page 59461]]

commenter states that EPA has not shown that carbon monoxide or 
hydrocarbon emissions correlate to dioxin/furan emissions, and, 
accordingly, has not shown that the carbon monoxide or hydrocarbon 
standard, together with the DRE standard, are valid surrogates.
    This commenter also states that it is inappropriate for EPA to use 
carbon monoxide or hydrocarbons and DRE as surrogates to establish 
dioxin/furan floors for liquid fuel boilers with wet or no air 
pollution control devices and for hydrochloric acid production 
furnaces. The commenter believes EPA inappropriately justifies these 
surrogates by claiming that a numerical dioxin/furan floor would not be 
replicable by the best sources or duplicable by the others. The 
commenter states that EPA has no discretion to avoid setting floors for 
a HAP just because it believes that HAP is not controlled with a 
technology. Rather, EPA must set floors reflecting the relevant best 
sources' actual performance. Such floors necessarily will be duplicable 
by the relevant best sources themselves. That they cannot be replicated 
by other sources is irrelevant according to the commenter.
    In addition, the commenter states that EPA does not claim or 
demonstrate that the carbon monoxide and hydrocarbon floors for solid 
fuel boilers reflect the average emission levels achieved by the 
relevant best sources.
    Finally, the commenter also notes that EPA appears to argue that 
its carbon monoxide or hydrocarbon standard and DRE standard could be 
viewed as work practice standards under section 112(h) which allows EPA 
to establish work practice standards in lieu of emission standards only 
if it is not be feasible to set the former. Because EPA has made no 
such demonstration, setting work practice standards to control dioxin/
furan emissions from boilers would be unlawful according to the 
commenter.
    Response: The commenter raises four issues: (1) Are the carbon 
monoxide/hydrocarbon standard and the DRE standard adequate surrogate 
floors to control dioxin/furan; (2) floors for existing sources must be 
established as the average emission limitation achieved by the best 
performing sources irrespective of whether the limitation is duplicable 
by the best performing sources or replicable by other sources; (3) EPA 
has not explained how the carbon monoxide and hydrocarbon floors 
reflect the average emission limitation achieved by the relevant best 
sources; and (4) EPA cannot establish work practice standards for 
dioxin/furan under section 112(h) because it has not demonstrated that 
setting an emission standard is infeasible under section 112(h)(1).
    Carbon Monoxide and Hydrocarbons Are Adequate Surrogates to Control 
Dioxin/Furan when Other Controls Are Not Effective or Achievable. 
Carbon monoxide and hydrocarbons (coupled with the DRE standard) are 
the best available surrogates to control dioxin/furan emissions when a 
numerical floor would not be achievable and when other indirect 
controls, such as control of the gas temperature at the inlet of a dry 
particulate matter control device to 400F, are not applicable or 
effective.\136\
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    \136\ As discussed in Part Two, Section V, we view the carbon 
monoxide, hydrocarbon, and destruction removal efficiency standards 
as unaffected by the Court's vacature of the September 1999 
challenged regulations for incinerators, cement kilns, and 
lightweight aggregate kilns. We are therefore not re-promulgating 
and reopening consideration of these standards in today's final rule 
for these source categories.
---------------------------------------------------------------------------

    As we explained at proposal, operating under good combustion 
conditions to minimize emissions of organic compounds such as 
polychlorinated biphenyls, benzene, and phenol that can be precursors 
to dioxin/furan formation is an important requisite to control dioxin/
furan emissions.\137\ See 69 FR at 21274. Minimizing dioxin/furan 
precursors by operating under good combustion practices plays a part in 
controlling dioxin/furan emissions, and that role is substantially 
enhanced when there are no other dominant factors that relate to 
dioxin/furan formation and emission (e.g., operating a dry particulate 
matter control device at temperatures above 400F).
---------------------------------------------------------------------------

    \137\ Operating under good combustion conditions also helps 
minimize soot formation on boiler tubes. Research has shown that 
operating under conditions that can form soot followed by operating 
under good combustion conditions can lead to dioxin/furan formation. 
See Section 2.4 of Volume III of the Technical Support Document.
---------------------------------------------------------------------------

    Carbon monoxide and hydrocarbons are widely accepted indicators of 
combustion conditions. The current RCRA regulations for boilers and 
hydrochloric acid production furnaces use emissions limits on carbon 
monoxide and hydrocarbons to control emissions of toxic organic 
compounds. See 56 FR 7150 (February 21, 1991) documenting the 
relationship between carbon monoxide, combustion efficiency, and 
emissions of organic compounds. In addition, carbon monoxide and 
hydrocarbons are used by many CAA standards for combustion sources to 
control emissions of organic HAP, including: MACT standards for 
hazardous waste burning incinerators, hazardous waste burning cement 
kilns, hazardous waste burning lightweight aggregate kilns, Portland 
cement plants, and industrial boilers; and section 129 standards for 
commercial and industrial waste incinerators, municipal waste 
combustors, and medical waste incinerators. Finally, hydrocarbon 
emissions are an indicator of organic hazardous air pollutants because 
hydrocarbons are a direct measure of organic compounds.
    Commenters on our proposed MACT standards for hazardous waste 
incinerators, cement kilns, and lightweight aggregate kilns stated that 
EPA's own surrogate evaluation \138\ did not demonstrate a relationship 
between carbon monoxide or hydrocarbons and organic HAP at the carbon 
monoxide and hydrocarbon levels evaluated. See 64 FR at 52847 
(September 30, 1999). Several commenters on that proposed rule noted 
that this should not have been a surprise given that the carbon 
monoxide and hydrocarbon emissions data evaluated were generally from 
hazardous waste combustors operating under good combustion conditions 
(and thus, relatively low carbon monoxide and hydrocarbon levels). 
Under these conditions, emissions of HAP were generally low, which made 
the demonstration of a relationship more difficult. These commenters 
noted that there may be a correlation between carbon monoxide and 
hydrocarbons and organic HAP, but it would be evident primarily when 
actual carbon monoxide and hydrocarbon levels are higher than the 
regulatory levels. We agreed with those commenters, and concluded that 
carbon monoxide and hydrocarbon levels higher than those we established 
as emission standards for hazardous waste burning incinerators, cement 
kilns, and lightweight aggregate kilns are indicative of poor 
combustion conditions and the potential for increased emissions organic 
HAP. We continue to believe that carbon monoxide and hydrocarbons are 
adequate surrogates for organic HAP which may be precursors for dioxin/
furan formation and note that the commenter did not explain why our 
technical analysis is problematic.
---------------------------------------------------------------------------

    \138\ See Energy and Environmental Research Corporation, 
``'Surrogate Evaluation of Thermal Treatment Systems,''' Draft 
Report, October 17, 1994.
---------------------------------------------------------------------------

    Emissions that Are Not Replicable or Duplicable Are Not Being 
``Achieved''. The commenter believes that floors must be established as 
the average emission limitation of the best performing sources 
irrespective of whether they are replicable by the best performing 
sources or duplicable by other sources. To the contrary, emission

[[Page 59462]]

levels that are not replicable by the best performing sources are not 
being ``achieved'' by those sources and cannot be used to establish the 
floor.
    For solid fuel boilers, we explained at proposal why dioxin/furan 
emissions are not replicable by the best performing sources (or 
duplicable by other sources): there is no dominant, controllable means 
that sources are using that can control dioxin/furan emissions to a 
particular level. See 69 FR at 21274-75. We explained that data and 
information lead us to conclude that rapid quench of post-combustion 
gas temperatures to below 400 [deg]F--the control technique that is the 
basis for the MACT standards for dioxin/furan for hazardous waste 
burning incinerators, and cement and lightweight aggregate kilns--is 
not the dominant dioxin/furan control mechanism for coal-fired boilers. 
We believe that sulfur contributed by the coal fuel is a dominant 
control mechanism by inhibiting formation of dioxin/furan. Nonetheless, 
we do not know what minimum level of sulfur provides significant 
control. Moreover, sulfur in coal causes emissions of sulfur oxides, a 
criteria pollutant, and particulate sulfates. For this reason, as well 
as reasons stated at 69 FR 21275, we are not specifying a level of 
sulfur in coal for these sources as a means of dioxin/furan control.
    The same rationale applies to liquid fuel boilers with no air 
pollution controls or wet air pollution control systems and to 
hydrochloric acid production furnaces--there is no dominant, 
controllable means that sources are using that can control dioxin/furan 
emissions to a particular emission level.\139\ Thus, best performer 
dioxin/furan emissions are not replicable by the best performing 
sources (or duplicable by other sources). For these sources, the 
predominant dioxin/furan formation mechanism for other source 
categories--operating a fabric filter or electrostatic precipitator 
above 400F--is not a factor.
---------------------------------------------------------------------------

    \139\ We note that the same rationale also applies to 
incinerators with wet or no air pollution control equipment and that 
are not equipped with a waste heat boiler.
---------------------------------------------------------------------------

    Given that these sources are not using controllable means to 
control dioxin/furan to a particular emission level, there is no 
assurance that the best performers can achieve in the future the 
emission level reported in the compliance test in our data base. Put 
another way, the test data do not reflect these sources' variability, 
and the variability is largely unquantifiable given the uncertainties 
regarding control mechanisms plus the environmental counter-
productiveness of encouraging use of higher sulfur coal. Hence, that 
reported emission level is not being ``achieved'' for the purpose of 
establishing a floor.
    Finally, we note that beyond-the-floor controls such as activated 
carbon can control dioxin/furan to a particular emission level. If a 
source were to install activated carbon, it could achieve the level 
demonstrated in a compliance test, after adjusting the level to account 
for emissions variability to ensure the measurement was replicable. The 
commenter argues that such a result is mandatory under the straight 
emissions approach (the only way the commenter believes best performers 
can be determined). Doing so, however, would amount to a surreptitious 
beyond-the-floor standard (forcing adoption of a control technology not 
used by any existing source), without considering the beyond-the-floor 
factors set out in section 112(d)(2). In fact, we considered beyond-
the-floor standards based on use of activated carbon for these 
sources--solid fuel boilers, liquid fuel boilers with wet or no 
emission control device, and hydrochloric acid production furnaces--but 
rejected them for reasons of cost. The cost-effectiveness ranged from 
$2.5 million to $4.9 million per gram TEQ of dioxin/furan removed. In 
contrast, the cost-effectiveness of the beyond-the-floor standard we 
promulgate for liquid fuel boilers equipped with dry emission control 
devices is $0.63 million per gram TEQ of dioxin/furan removed.\140\
---------------------------------------------------------------------------

    \140\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' September 
2005, Sections 12, 13, and 15.
---------------------------------------------------------------------------

    Consequently, we are not promulgating a beyond-the-floor standard 
for dioxin/furan for these sources, and do not believe we should adopt 
such a standard under the guise of determining floor levels.
    The Carbon Monoxide and Hydrocarbon Floors Are Appropriate MACT 
Floors. We explained at proposal why the carbon monoxide standard of 
100 ppmv and the hydrocarbon standard of 10 ppmv are appropriate 
floors. See 69 FR at 21282. The floor level for carbon monoxide of 100 
ppmv is a currently enforceable Federal standard. Although some sources 
are achieving carbon monoxide levels below 100 ppmv, it is not 
appropriate to establish a lower floor level because carbon monoxide is 
a conservative surrogate for organic HAP. Organic HAP emissions may or 
may not be substantial at carbon monoxide levels greater than 100 ppmv, 
and are extremely low when sources operate under the good combustion 
conditions required to achieve carbon monoxide levels in the range of 
zero to 100 ppmv.\141\ (See also the discussion below regarding the 
progression of hydrocarbon oxidation to carbon dioxide and water). As 
such, lowering the carbon monoxide floor below 100 ppmv may not provide 
significant reductions in organic HAP emissions. Moreover, it would be 
inappropriate to establish the floor blindly using a mathematical 
approach--the average emissions for the best performing sources--
because the best performing sources may not be able to replicate their 
emission levels (and other sources may not be able to duplicate those 
emission levels) using the exact types of good combustion practices 
they used during the compliance test documented in our data base. This 
is because there are myriad factors that affect combustion efficiency 
and, subsequently, carbon monoxide emissions. Extremely low carbon 
monoxide emissions cannot be assured by controlling only one or two 
operating parameters.
---------------------------------------------------------------------------

    \141\ We note, however, that this general principle may not 
always apply. There are data that indicate that even though carbon 
monoxide levels are below 100 ppmv, hydrocarbon levels may not 
always be below 10 ppmv. See 64 FR at 52851 and Part Four, Section 
IV B. and C. of this preamble. An example of how this might occur, 
although not a likely practical scenario, is if combustion is 
quenched before substantial carbon monoxide can be generated, 
leaving unburned hydrocarbons in the stack gas. Because of this 
potential (although unlikely) concern, the rule requires sources 
that elect to monitor carbon monoxide rather than hydrocarbons to 
conduct a one-time test to document that hydrocarbons are below 10 
ppmv and to establish operating limits on parameters that affect 
combustion conditions (i.e., the same operating parameters that we 
use for compliance assurance with the DRE standard). See Sec.  
63.1206(b)(6).
---------------------------------------------------------------------------

    We proposed a floor level for hydrocarbons of 10 ppmv even though 
the currently enforceable standard for boilers and hydrochloric acid 
production furnaces is 20 ppmv because: (1) Although very few sources 
elect to comply with the RCRA standard for hydrocarbons rather than the 
standard for carbon monoxide, those that comply with the hydrocarbon 
standard have hydrocarbon levels well below 10 ppmv; and (2) reducing 
hydrocarbon emissions within the range of 20 ppmv to 10 ppmv may reduce 
emissions of organic HAP.
    Although all sources are likely to be achieving hydrocarbon levels 
below 10 ppmv, it is not appropriate to establish a lower floor level 
because hydrocarbons are a surrogate for organic HAP. Although total 
hydrocarbons would be reduced at a floor level below 10 ppmv, we do not 
know whether

[[Page 59463]]

organic HAP would be reduced substantially. As combustion conditions 
improve and hydrocarbon levels decrease, the larger and easier to 
combust compounds are oxidized to form smaller compounds that are, in 
turn, oxidized to form carbon monoxide and water. As combustion 
continues, carbon monoxide is then oxidized to form carbon dioxide and 
water. Because carbon monoxide is a difficult-to-destroy refractory 
compound (i.e., oxidation of carbon monoxide to carbon dioxide is the 
slowest and last step in the oxidation of hydrocarbons), it is a 
conservative surrogate for destruction of hydrocarbons, including 
organic HAP, as discussed above. As oxidation progresses and 
hydrocarbon levels decrease, the larger, heavier compounds are 
destroyed to form smaller, lighter compounds until ideally all 
hydrocarbons are oxidized to carbon monoxide (and then carbon dioxide) 
and water. Consequently, the relationship between total hydrocarbons 
and organic HAP becomes weaker as total hydrocarbon levels decrease to 
form compounds that are not organic HAP, such as methane and 
acetylene.\142\
---------------------------------------------------------------------------

    \142\ USEPA, Technical Support Document for HWC MACT Standards, 
Volume III: Selection of MACT Standards and Technologies, July 1999, 
Section 12.1.2.
---------------------------------------------------------------------------

    Moreover, as discussed above for carbon monoxide, it would be 
inappropriate to establish the floor blindly using a mathematical 
approach--the average emissions for the best performing sources--
because the best performing sources may not be able to replicate their 
emission levels (and other sources may not be able to duplicate those 
emission levels) using the exact types of good combustion practices 
they used during the compliance test documented in our data base. This 
is because there are myriad factors that affect combustion efficiency 
and, subsequently, hydrocarbon (and carbon monoxide) emissions. 
Extremely low hydrocarbon emissions cannot be assured by controlling 
only one or two operating parameters.
    The Standards for CO and HC Are Not Work Practice Standards. The 
floor standards for CO or HC for boilers and hydrochloric acid 
production furnaces are quantified emission limits. The standards 
consequently are not work practice standards (even though they 
represent levels showing good combustion control). CAA section 302(k). 
EPA's reference to section 112(h)(1) at proposal (69 FR at 21275) was 
consequently erroneous.

C. Use of Carbon Monoxide and Total Hydrocarbons as Surrogate for Non-
Dioxin Organic HAP <SUP>143</SUP>

    Comment: A commenter states that neither the total hydrocarbon nor 
carbon monoxide standard alone provides adequate surrogate control for 
organic HAP. Accordingly, EPA must include standards for both. 
Hazardous waste combustors could have total hydrocarbon levels below 
the standard during the carbon monoxide compliance tests, but higher 
total hydrocarbon levels at other times during normal operation because 
there are many variables that can affect total hydrocarbon emissions, 
and these will not all be represented during the carbon monoxide 
compliance test. The commenter states that EPA is on record stating 
that carbon monoxide limits alone may not by itself minimize organic 
emissions because products of incomplete combustion can result from 
small pockets within the combustion zone where adequate time, 
temperature, turbulence and oxygen have not been provided to completely 
oxidize these organics. The commenter also states that EPA is on record 
stating that total hydrocarbon levels can exceed good combustion 
condition levels when carbon monoxide levels are below 100 ppmv.
---------------------------------------------------------------------------

    \143\ As discussed in part two, section V, we view carbon 
monoxide, hydrocarbon, and destruction removal efficiency standards 
as unaffected by the Court's vacature of the September 1999 
challenged regulations for incinerators, cement kilns, and 
lightweight aggregate kilns. We are therefore not re-promulgating 
and did not reconsider these standards in today's final rule for 
these source categories.
---------------------------------------------------------------------------

    Response: The final rule requires compliance with destruction and 
removal efficiency and carbon monoxide or hydrocarbon standards as 
surrogates to control non-dioxin organic HAP emissions \144\ from 
liquid fuel boilers, solid fuel boilers, and hydrochloric acid 
production furnaces. These are effective and reliable surrogates to 
control organic HAP. We conclude that simultaneous measurement of both 
total hydrocarbons and carbon monoxide with continuous emission 
monitors is not necessary because each serves as a reliable surrogate 
to control organic HAP emissions. The commenter has cited EPA preamble 
language that was included in the April 19, 1996 proposed rule for 
hazardous waste incinerators, cement kilns, and lightweight aggregate 
kilns. In that rule we proposed to require compliance with both the 
total hydrocarbon standard and the carbon monoxide standard. We 
requested comment on whether these requirements were redundant, and we 
later requested comment on whether we should allow sources to comply 
with either the carbon monoxide standard or the total hydrocarbon 
standard. We clarified, however, that allowing sources to comply with 
the carbon monoxide standard would be contingent on the source 
demonstrating compliance with the hydrocarbon standard during the 
compliance test. We believed this was necessary because we had limited 
data that showed a source could have total hydrocarbon levels exceeding 
10 ppmv even though their carbon monoxide emission levels were below 
100 ppmv. EPA subsequently promulgated this approach in the September 
1999 Final Rule. 62 FR 52829.
---------------------------------------------------------------------------

    \144\ As discussed in the previous section, these standards are 
also used as surrogates to control dioxin/furans for hydrochloric 
acid production furnaces, solid fuel-fired boilers, and liquid fuel-
fired boilers that are not equipped with dry air pollution control 
devices.
---------------------------------------------------------------------------

    Today's rule adopts the same approach for liquid and solid fuel 
boilers and hydrochloric acid production furnaces. We again conclude 
that it is not necessary to require sources to verify compliance with 
both of these standards on a continuous basis with two separate 
continuous emission monitors, given the redundancy of these measurement 
techniques. Total hydrocarbon emission measurements are a more direct 
indicator of organic HAP emissions than carbon monoxide. Hence, 
continuous compliance with this standard always assures that organic 
HAP are well controlled. Carbon monoxide is a conservative indicator of 
combustion efficiency because it is a product of incomplete combustion 
and because it is a refractory compound that is more thermally stable 
than hydrocarbons. The hydrocarbon products of incomplete combustion 
that are simultaneously formed during incomplete, or inefficient, 
combustion conditions can be subsequently oxidized later in the 
combustion process. In such instances carbon monoxide will likely still 
be prevalent in the exhaust gas even though the products of incomplete 
combustion were later oxidized. The conservative nature of carbon 
monoxide as an indicator of good combustion practices is supported by 
our data. At carbon monoxide levels less than 100 ppmv, our data 
indicates that there is no apparent relationship between carbon 
monoxide and hydrocarbons (other than that hydrocarbon levels are 
generally below 10 ppm when carbon monoxide levels are below 100 ppm). 
For example, a source with a carbon monoxide level of 1 ppm is no more 
likely to have lower

[[Page 59464]]

measured hydrocarbons than a source achieving a carbon monoxide 
emission level of 100 ppm. \145\
---------------------------------------------------------------------------

    \145\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' September 
2005, Section 3.2 and USEPA, ``Final Technical Support Document for 
the HWC MACT Standards, Volume III: Selection of MACT Standards and 
Technologies,'' July 1999, Section 5.1.
---------------------------------------------------------------------------

    We consider the few instances where the data showed total 
hydrocarbon levels above 10 ppmv while carbon monoxide levels are below 
100 ppmv to be anomalies. Even so, we have accounted for this by 
requiring compliance with the hydrocarbon standard during the 
compliance test if a source elects to comply with the carbon monoxide 
standard. See Sec. Sec.  Sec.  63.1216(a)(5)(i), 1217(a)(5)(i), and 
1218(a)(5)(i).
    We disagree with the commenter's assertion that the total 
hydrocarbon compliance demonstration during the compliance test is 
insufficient. Sources are required to establish numerous operating 
requirements based on operating levels that were demonstrated during 
the test, including minimum operating temperature, maximum feed rates, 
minimum combustion zone residence time, and operating requirements on 
the hazardous waste firing system that control liquid waste atomization 
efficiency. Sources must comply with these operating requirements on a 
continuous basis. Compliance with these requirements, in addition to 
the requirements to comply with the carbon monoxide and destruction and 
removal standards, adequately assure sources are controlling organic 
HAP emissions to MACT levels.
    Comment: A commenter states that EPA's proposed use of surrogates 
for organic HAP do not ensure that each of the organic HAP (e.g., 
polychlorinated biphenyls and polyaromatic hydrocarbons) are reduced to 
the level of the HAP emitted by the relevant best performing sources. 
EPA has not shown the necessary correlation between either the total 
hydrocarbon or carbon monoxide standards and organic HAP, and neither 
is a reasonable surrogate according to the commenter.
    Response: Carbon monoxide and total hydrocarbon monitoring are 
widely used and accepted indicators of combustion efficiency, and hence 
control organic HAP, which are destroyed by combustion.\146\ Sources 
that are achieving carbon monoxide of emission levels of 100 ppm or a 
hydrocarbon emission levels of 10 ppm are known to be operating 
pursuant to good combustion practices. This is supported by an 
extensive data analysis we used to support identical standards for 
incinerators, cement kilns, and lightweight kilns which were 
promulgated in the September 1999 Final Rule. We are applying the same 
rationale to support these standards for boilers and hydrochloric acid 
production furnaces.
---------------------------------------------------------------------------

    \146\ This is why almost all of the RCRA Land Disposal 
Restiction treatment standards for organic waste, which standards 
are for the most part established at an analytic detection level for 
the organic HAP in question plus a variability factor, are based on 
the performance of combustion technology. See 40 CFR Part 268.40-43.
---------------------------------------------------------------------------

    Today's rule requires continuous compliance with either a carbon 
monoxide and hydrocarbon standard, in combination with a destruction 
and removal efficiency standard, as surrogates to control organic HAP. 
We conclude that sources which comply with these standards are 
operating under efficient combustion conditions, assuring non-dioxin 
organic HAP are being oxidized, thus limiting emissions to levels 
reflecting MACT. Efficient combustion of hazardous waste minimizes 
emissions of organic HAP that are fed to the combustion chamber as well 
as emissions attributable to products of incomplete combustion that may 
form within the combustion chamber or post combustion. We are not 
capable of issuing emission standards for each organic HAP because of 
data limitations and because such emission standards may not be 
replicable by individual sources or duplicable by the other best 
performing sources because of the complex nature of combustion and post 
combustion formation of products of incomplete combustion.

V. Additional Issues Relating to Variability and Statistics

    Many commenters raised issues relating to emissions variability and 
statistics other than those discussed above in Section III.A: (1) 
Variability dampening for data sets containing nondetects; (2) 
imputation of variability to address variability dampening for data 
sets containing nondetects; and (3) our analysis of variance procedures 
to identify subcategories. We present comments and responses on the 
remaining topics below.

A. Data Sets Containing Nondetects

    Comment: One commenter states that EPA's approach of assuming 
measurements that are below detection limits are present at the 
detection limit dampens the variability of the data set. Thus, the 
variability of ranking parameters is understated when ranking sources 
to identify the best performers and emissions variability is 
understated when calculating the floor.
    Response: We agree with the commenter. For the final rule, we use 
an approach to address nondetects whereby a value is assigned to each 
nondetect within its possible range such that the 99th percentile upper 
prediction limit for the data set (i.e., test condition runs for each 
source) is maximized. Although this approach maximizes the deviation 
among runs containing nondetect measurements, the test condition 
average is lower because we no longer assume the nondetect analyte is 
present at the level of detection. See response to comments discussion 
below for more information on this statistical approach to address 
variability of nondetects.
    We use this measurement imputation approach to address variability 
of feedrate data sets containing nondetects for source ranking purposes 
and to address variability of emissions data sets containing nondetects 
when calculating floors. We do not apply the measurement implementation 
approach to system removal efficiency (SRE) data sets where feedrates 
or emissions contain nondetects, however. Statistical imputation of 
nondetect SREs is complicated given that SRE is derived from feedrate 
and emissions data, both of which could contain nondetect 
measurements.\147\ Our inability to apply the imputation approach to 
SREs is not a major concern, however, because system removal efficiency 
is used as a source ranking criterion only (i.e., it is not used as the 
standard, except for hydrochloric acid production furnaces where there 
are no nondetect feedrate or emissions measurements), and there are few 
instances where system removal efficiencies are derived from nondetect 
feedrate or emissions data.
---------------------------------------------------------------------------

    \147\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' September 2005 
Section 7.3.
---------------------------------------------------------------------------

B. Using Statistical Imputation To Address Variability of Nondetect 
Values

    On February 4, 2005, EPA distributed by email to major commenters 
on the proposed rule a direct request for comments on a limited number 
of issues that were raised by the public comments on the proposed rule. 
The nondetect measurement imputation approach discussed above was one 
of the issues for which we requested comment. We discuss below the 
major comments on the approach.
    Comment: Most commenters state that they agree with either the 
concept or the approach in principle but cannot

[[Page 59465]]

provide substantive comments. These commenters indicate they cannot 
provide substantive comments because they cannot determine the 
implications of using the approach given that we did not provide the 
resulting floor calculations. One commenter suggests that, before 
blindly applying this arbitrary estimate of a nondetect value, a 
reality check should be done to validate that this is reasonable by 
consulting what is published on the method variability, as well as by 
checking variability factors derived for other data in the database 
that are above the detection limit.
    Another commenter voiced significant concerns with the approach. 
The commenter states that EPA contradicts its assumption at proposal 
that all data that are reported as nondetect are present at the 
detection limits by now admitting that the true value is between zero 
and the level of detection. The commenter concludes that EPA now 
proposes to retreat from its assumption that undetected pollutants are 
always present at the detection limits not because that assumption is 
false but because it does not generate sufficiently lenient floors. The 
commenter believes that this underscores that EPA's statistical 
analysis approach cannot possibly give an accurate picture of any 
source's actual emission levels. Accordingly, it cannot possibly 
satisfy EPA's obligation to ensure that its floors reflect the average 
emission levels achieved by the relevant best performing sources.
    The commenter also states that EPA's imputation approach is 
independently flawed because it assumes--again inaccurately--that the 
value for a nondetect is always either the highest value or lowest 
value in the allowable range. In reality the undetected values will 
necessarily fall in a range between the highest and lowest, and thus 
yield less variability than EPA would assume.
    Response: We agree in theory with the commenter who suggests that 
the results of the imputation approach should be checked to see if it 
overstates variability for nondetect data by comparing the results of 
the imputation approach with the actual variability for detected 
measurements in the data set. We considered comparing the relative 
standard deviation derived from the imputation approach for data sets 
with nondetects, to the relative standard deviation for the data set 
using a regression analysis. Under the regression analysis approach, we 
considered relating the relative standard deviation of detected data 
sets to the average measurement. We would determine this relationship 
for each standard for which we have nondetect data, and use the 
relationship to impute the standard deviation for a data set containing 
nondetects.\148\
---------------------------------------------------------------------------

    \148\ Note that, under this approach, we would continue to 
assume that the nondetect analyte is present at the detection limit.
---------------------------------------------------------------------------

    We could not perform this analysis, however, because: (1) We have 
very few detected measurements for the data sets for several standards 
and could not establish the relationship between relative standard 
deviation and emission concentration for those data sets; and (2) 
moreover, for many data sets where detected measurements would have 
been adequate to establish the relationship, it would have been 
problematic statistically to extrapolate the relationship to the very 
low values assigned to the nondetect measurements (e.g., 100% of the 
detection limit; the value assigned by our statistical imputation 
approach).\149\
---------------------------------------------------------------------------

    \149\ Note that this was not the case where we use a regression 
analysis of relative standard deviation versus total chlorine 
measurements to impute a standard deviation for values below 20 ppmv 
that we corrected to 20 ppmv to address the low bias of Method 0050. 
In that situation, we have several total chlorine measurements very 
close to 20 ppmv.
---------------------------------------------------------------------------

    This commenter also suggests that we check the resultant standard 
deviation after imputation by consulting what is published on the 
method variability. The commenter did not explain, however, how method 
variability relates to the variability of nondetect data.
    Moreover, we believe that the imputation approach is one approach 
we could have reasonably used to estimate variability of nondetect 
data. We first attempted to apply standard statistical techniques to 
address the nondetect issue. We investigated standard interval 
censoring techniques to calculate maximum likelihood estimates (MLE) of 
the average and standard deviation that provide the best fit for a 
normal distribution for the data containing nondetect values, taking 
into account that each nondetect data point can be anywhere within its 
allowable interval. These techniques are not applicable, however, to 
data sets where all data are nondetects, as is the case for many of our 
data sets. In that situation, we approximated the mean as the average 
of the midpoints of the nondetect intervals, and the standard deviation 
as one half of the possible range of the data.
    After working with this MLE/Approximation approach for some time 
and iteratively developing complicated algorithms to address problems 
as they arose, we concluded that we needed a simpler approach that 
could be applied to all data sets. Accordingly, we developed the 
statistical imputation approach discussed in Section IV.A above.
    For 22 separate floors, we compared the results of the approaches 
we considered for nondetects: (1) Nondetects present at the detection 
limit (i.e., full detection limit approach); (2) MLE; (3) MLE combined 
with an approximation approach (i.e., MLE/Approximation approach; and 
(4) statistical imputation.\150\ The MLE approach was only applicable 
to 2 of the 22 floor data sets, and the numerical algorithm failed to 
converge on an answer for one of those. The MLE/Approximation approach 
sometimes results in floors that are unrealistically high (i.e., it 
calculated 5 of 22 floors that were higher than the statistical 
imputation approach, which always produces floors that are equal to or 
higher than assuming nondetects are present at the full detection 
limit), and sometimes fails to converge on an answer. Because of these 
limitations, we do not use either the MLE or MLE/Approximation 
approach.
---------------------------------------------------------------------------

    \150\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' September 
2005, Section 5.4.
---------------------------------------------------------------------------

    We believe the statistical imputation approach is preferable to the 
full detection limit approach because it: (1) Accounts for variability 
of data sets containing nondetects; (2) can be applied to all data sets 
containing nondetects; and (3) results in reasonable floor levels. In 
most cases, floors calculated using statistical imputation are close to 
those calculated by the full detection limit approach. The statistical 
imputation approach can produce substantially higher floors than the 
full detection limit approach, however, when a relatively high 
nondetect is reported because of a high detection limit. Nonetheless, 
the statistical imputation approach calculated floors that were 30% 
higher than the full detection limit approach for only 2 of the 22 
floors.
    We reject the comment that our approach to handling nondetect data 
is a mere manipulation to raise the floor. The commenter observes that 
EPA appears to determine that its initial approach of assuming the 
worst-case for nondetect data--that the data are present at the 
detection limit--did not produce floors that were high enough, and 
consequently applies another manipulation--statistical imputation of 
nondetect measurements--that assumes the nondetect data are present at 
lower levels but nonetheless generates floors that are even higher than 
before. Although the commenter is correct

[[Page 59466]]

about the outcome of our handling of nondetect data'the floors are 
generally higher after statistically imputing nondetect measurements 
than if nondetects are simply assumed to be present at the detection 
limit--our rationale for handling nondetects is sound. At proposal, we 
assumed that nondetects are present at the detection limit. We do not 
know (nor does anyone else) whether a nondetect value is actually 
present at 1% or 99% of the detection limit. We thought that assuming 
that all values were at the limit of detection would reasonably 
estimate the range of performance a source could experience for these 
nondetect measurements. This approach inherently maximizes the average 
emissions but minimizes emissions variability.
    Commenters on the proposed rule state that assuming nondetects are 
present at the detection limit dampens emissions variability--a 
consideration necessary to ensure that a source's performance over time 
is estimated reasonably. Mossville, 370 F. 3d at 1242 (daily maximum 
variability must be accounted for in MACT standards [including floors] 
which must be achieved continuously). See also CMA, 870 F. 2d at 232 
(EPA not even obligated to use data from plants that consistently 
reported nondetected values in calculating variability factors for best 
performing plants). We agree with these commenters, and are using the 
statistical imputation approach to address the concern. Relative to our 
proposed approach of assuming nondetect measurements are present at the 
detection limit, the statistical imputation approach reduces the 
average of the data set for a source while maximizing the deviation of 
the data set. These are competing and somewhat offsetting factors when 
calculating the floor for existing sources given that we use a modified 
99th percentile upper prediction limit to calculate the floor--the 
floor is the average of the test condition averages for the best 
performers plus the pooled variance of their runs. See CMA, 870 F. 2d 
at 232 (upholding approach to variability for datasets with nondetect 
values where various conservative assumptions in methodology offset 
less conservative assumptions).
    We further disagree with this commenter's view that the statistical 
imputation approach is independently flawed because it assumes that the 
value for a nondetect is always either the highest value or lowest 
value in the allowable range. The commenter states that, in reality, 
the undetected values will necessarily fall in a range between the 
highest and lowest, and thus yield less variability than EPA would 
assume. Although the commenter is correct that the true value of a 
nondetect measurement is likely to be in the range between the highest 
or lowest value possible rather than at either extreme, we do not know 
where the true value is within that range. To ensure that variability 
is adequately considered in establishing a floor, the statistical 
imputation approach, by design, maximizes the deviation by assuming the 
nondetect value is at one end of the range or the other, whichever 
results in a higher average for the data set.

C. Analysis of Variance Procedures To Assess Subcategorization

    We use analysis of variance (ANOVA) to determine whether 
subcategories of sources have significantly different emissions. For 
two subsets of emissions, the variance of the data between the two 
subsets is compared to the variance within the subsets. The ratio of 
these two variances is called the F-statistic. The larger the F-
statistic the more likely the underlying data distributions are 
different. To make a decision regarding the difference between the two 
subsets, we compare this calculated F-statistic to an F-value 
associated with a particular confidence level.
    One commenter has raised several concerns with our use of the ANOVA 
procedure in the selection of incinerator subcategories.
    Comment: The ANOVA procedure is based upon the assumption that the 
underlying distribution of both data sets has a normal shape. For 
incinerator emissions data this assumption is not valid. A log-
probability plot shows that particulate emission data is better 
described by a lognormal distribution. Prior to conducting the ANOVA 
procedure, the data should be log-transformed.
    Response: We use probability plots, Skewness Coefficients, and 
Correlation Coefficient/Shapiro-Wilks testing to evaluate whether it is 
more appropriate to analyze emissions data for ANOVA and floor 
calculations assuming the data represent a normal or lognormal 
distribution. We believe it is reasonable to assume the data represent 
a normal distribution for several reasons.
    The purpose of the ANOVA subcategorization analysis is to determine 
if there is a significant difference in emission levels between 
potential subcategories to warrant establishing separate floors for the 
subcategories. Although in some cases it may appear that a data set in 
its entirety may be better represented by a lognormal distribution, the 
high emissions data causing the right-hand skew will be truncated when 
we identify the best performing sources--those with the lowest 
emissions--to calculate floors. This moves the appearance of a skewed 
distribution toward one that is more symmetric and thus, more 
representative of a normal distribution.
    In addition, our analyses showed: (1) The probability plots do not 
suggest that either assumed distribution is significantly or 
consistently better; (2) the data set arithmetic averages tend to be in 
the neighborhood of the medians, indicating the data sets are not 
significantly skewed and more closely normal than lognormal; and (3) in 
some cases, neither assumed distribution could be statistically 
rejected.\151\
---------------------------------------------------------------------------

    \151\ USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' September 
2005, Section 8.2.
---------------------------------------------------------------------------

    Comment: Some of the data sets used for comparison have very few 
members. This means that the within-group variance for a small data set 
would have to be very low for the two groups to be judged as separate.
    Response: We agree, but note that as the sample sizes change, the 
critical values are also changing depending on the degrees of freedom.
    Comment: Only emissions data were considered in the ANOVA tests. 
Feed rate and removal efficiency should have been considered as well.
    Response: Differences between subcategories in feedrates or system 
removal efficiency are irrelevant if there is no significant difference 
in emissions between the subcategories. The purpose of considering 
subcategorization is to determine if there are design, operation, or 
maintenance differences between subcategories that could affect the 
type or concentration of HAP emissions and thus sources' ability to 
achieve the floor absent subcategorization. Consequently, it is 
appropriate to consider emissions only when evaluating 
subcategorization.
    Comment: The confidence level used by EPA for the F-statistic in 
all cases was 95 percent. If the calculated F-statistic were equal to 
this 95 percent confidence value, it would mean that there is only a 5 
percent chance that data for the two subsets were drawn from the same 
parent distribution. A less stringent (lower) confidence level would be 
more appropriate for this analysis.
    The commenter evaluated particulate emissions for specialty 
incinerators (i.e., munitions, chemical weapons and mixed waste 
incinerators) and non-specialty incinerators (all others). The 
commenter log-transformed the data and

[[Page 59467]]

determined that there was only a 30 percent chance that the two data 
sets could come from the same parent distribution. This result, 
together with the vastly different operating characteristics for the 
two types of incinerators, argues for their being treated as separate 
categories, according to the commenter.
    Response: A confidence level of 95% assigns a probability of 0.95 
of accepting the hypothesis when there is no difference between 
subcategories and hence a probability of 0.05 of rejecting a true 
hypothesis. This reduces the probability to 5% of rejecting a true 
hypothesis. A less stringent confidence level would increase the 
chances of rejecting a true hypothesis. The farther apart the averages 
of the two potential subcategories are, the more likely they are to be 
statistically different and the more likely you are to be wrong if you 
hypothesize that they are not different.
    A 95% confidence level is most often used for ANOVA because it is 
generally believed that being wrong one time out of 20 is an acceptable 
risk for purposes of ANOVA. In addition, statisticians are comfortable 
with a 95% confidence level because, in a normal distribution, 95% of 
the data fall within 2 (actually 1.96) standard deviations of the mean.
    Other confidence levels could be used for ANOVA--99% or 90%--if 
there is a good reason to deviate from the general default of 95%. A 
99% confidence level is the second most commonly used confidence level 
and is generally used when it is very important that you be sure that 
you are right (i.e., where you can only accept the risk of being wrong 
1 time out of 100) before you classify the populations (in this case 
subcategories) as different. Occasionally, but much less frequently, 
confidence levels of 90% or less are used. But, we note that these 
situations are so infrequent that some statistics books provide tables 
for the ANOVA F-statistic only at the 95% and 99% confidence levels.
    For these reasons, we believe that the 95% confidence level is an 
appropriate level among those we could have reasonably selected.

VI. Emission Standards

A. Incinerators

    Comment: A commenter states that EPA's subcategorization (and 
assignment of differing dioxin/furan standards as a result) between 
incinerators with wet or no air pollution control device and 
incinerators equipped with dry air pollution control devices or waste 
heat boilers is unlawful because incinerators equipped with a given 
type of pollution control equipment are not different ``classes,'' 
``types,'' or ``sizes'' of source. The commenter implies that EPA 
justifies this subcategorization by stating that these sources have 
different emission characteristics, which is no less unlawful and 
arbitrary than subcategorizing based on the pollution control devices 
they use.
    Response: We agree that it would not be appropriate to 
subcategorize source categories based on a given air pollution control 
technique. See 69 FR at 403 (Jan. 4, 2004). As stated at proposal, we 
do not subcategorize incinerators with respect to dioxin/furans based 
on the type of air pollution control device used. 69 FR at 21214. For 
example, with respect to dioxin/furans, it would not be appropriate 
subcategorize based on whether a source is using: (1) Good combustion 
practices; (2) a carbon bed; (3) an activated carbon injection system; 
or (4) temperature control at the inlet to its dry air pollution 
control device. These devices and practices are what control dioxin/
furan emissions. Today's final rule does not subcategorize based on 
these control devices and practices. Instead, our subcategorization 
approach recognizes the potential of some emission control equipment to 
create pollutant emissions that subsequently must be addressed.\152\
---------------------------------------------------------------------------

    \152\ Although we subcategorize between incinerators with wet or 
no air pollution control device and incinerators equipped with dry 
air pollution control devices or waste heat boilers for the floor 
analysis, the calculated dioxin furan floors for both subcategories 
for existing sources were determined to be less stringent than the 
current interim standard. Subsequently, the final rule emission 
limitations for both subcategories are, for the most part, 
identical, and equivalent to the interim standard. See USEPA, 
``Technical Support Document for the HWC MACT Standards, Volume III: 
Selection of MACT Standards,'' September 2005, Section 10.1, for 
further discussion.
---------------------------------------------------------------------------

    Dioxin/furans are unique in that these pollutants are not typically 
present in the process inputs, but rather are formed in the combustor 
or in post combustion equipment. The primary cause of dioxin/furan 
emissions from incinerators not equipped with waste heat boilers is 
post combustion formation by surface-catalyzed reactions that occur 
within the dry air pollution system.\153\ This is evidenced by the 
statistically significant higher dioxin furan emissions for 
incinerators with dry air pollution control systems compared to those 
without dry systems.
---------------------------------------------------------------------------

    \153\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume IV: Selection of MACT Standards,'' September 2005, 
Section 3, for further discussion.
---------------------------------------------------------------------------

    Incinerators with dry air pollution systems are designed to 
effectively control metal and particulate matter emissions through use 
of baghouses, electrostatic precipitators, etc. Incinerators that are 
designed in this manner have the potential for elevated dioxin/furan 
emissions because dry air pollution control systems provide locations 
where surface-catalyzed reactions can occur (e.g., on particles on 
fabric filter bags or electrostatic precipitator plates). Thus, for 
purposes of dioxin/furan formation and control, incinerators equipped 
with dry air pollution systems are in fact different ``types'' of 
incinerators because of their unique pollutant generation 
characteristics.
    On the other hand, incinerators with wet air pollution control 
systems are generally designed to effectively reduce total chlorine 
emissions (with the use of wet scrubbers) and metals and particulate 
matter emissions. There generally is a tradeoff, however, in that these 
types of incinerators may not be as efficient in reducing particulate 
matter and metal emissions compared to incinerators that are equipped 
with baghouses and dry electrostatic precipitators. These types of 
incinerators generally do not have the potential to have elevated 
dioxin/furan emissions because they do not provide locations where 
surface catalyzed reactions can occur. For purposes of dioxin/furan 
emission formation and control, sources with wet air pollution control 
systems are thus likewise different types of incinerators.\154\
---------------------------------------------------------------------------

    \154\ A similar analogy applies to incinerators that are not 
equipped with air pollution systems. These incinerators are not 
designed to control emissions of metals, chlorine, and particulate 
matter (perhaps because emission levels are low due to low HAP feed 
levels). Similar to incinerator types with wet systems, this design 
does not provide the locations for surface catalyzed reactions to 
occur, which leads us to conclude that these are different types of 
incinerator with respect to dioxin/furan control.
---------------------------------------------------------------------------

    Subcategorizing dry air pollution systems and wet air pollution 
control systems for purposes of establishing a dioxin/furan standard is 
no different than subcategorizing incinerators equipped with waste heat 
boilers. The waste heat boiler is the origin of the dioxin/furan that 
is generated. These incinerators are designed to efficiently recover 
heat from the flue gas to produce useful energy. A result of this type 
of incinerator design, however, is that it also provides a location 
where surface catalyzed reactions can occur (i.e., the boiler tubes), 
potentially resulting in elevated dioxin/furan formation (and emissions 
if not properly controlled).
    An alternative approach that does not subcategorize these sources, 
but rather identifies best performing sources as those sources with the 
lowest emissions irrespective of whether they have a wet

[[Page 59468]]

or dry air pollution control device, would yield floors that would not 
be achievable unless all the sources, including the best performers, 
adopted beyond-the-floor technology. The calculated dioxin/furan floor 
for existing incinerators and liquid fuel boilers using such an 
approach would be 0.008 and 0.009 ng TEQ/dscm, respectively.\155\ All 
of the best performing sources for these calculated floors had either 
wet air pollution systems or no air pollution control systems. The 
floor technology used by these sources is good combustion practices. As 
a result, these floor levels would not be replicable by these best 
performing sources nor duplicable by other sources through use of the 
same good combustion practices because of the uncertainties associated 
with dioxin/furan generation mechanisms and rates that can vary both 
within sources and across sources, potentially leading to significant 
variability in emission levels.\156\ Sources equipped with wet or no 
air pollution systems would thus likely be required to install carbon 
systems to comply with these standards, a technology used by only four 
incinerators (none of which were best performers in the above discussed 
floor analysis). Such an outcome should be viewed as a beyond-the-floor 
technology and therefore assessed pursuant to the factors enumerated in 
section 112(d)(2). Furthermore, it is unclear, and perhaps doubtful, 
that these floors would be achievable by these sources even if they 
were to install beyond-the-floor controls such as activated carbon 
systems because no sources using activated carbon are currently 
achieving those floor levels. We therefore conclude that it is 
appropriate, and necessary, to subcategorize these types of 
incinerators for purposes of calculating dioxin/furan floor standards.
---------------------------------------------------------------------------

    \155\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' September 
2005, Section 20 and Appendix C, tables labeled ``E-INC-all-DF'' and 
``E-LFB-all-DF''.
    \156\ Dioxin/furan formation mechanisms are complex. Sources 
equipped with wet or no air pollution control systems cannot rely on 
good combustion practices alone to achieve these floor levels 
because they cannot ``dial in'' to a specific emission level, as is 
the case with typical back-end control systems that control 
particulate matter and metals, for example. See Part Four, Section 
IV.B.
---------------------------------------------------------------------------

B. Cement Kilns

1. Hg Standard
    Comment: Several commenters recommend that EPA use a commenter-
submitted dataset, which includes three years of data documenting day-
to-day levels of mercury in hazardous waste fuels fired to all 
hazardous waste burning cement kilns, to identify a MACT floor for 
existing and new cement kilns. Several commenters state that existing 
cement kilns should have the option to comply with either of the 
following mercury standards: (1) A hazardous waste feed concentration 
limit, expressed in ppmw, based on an evaluation of the five best 
performing sources within the commenter-submitted dataset (documenting 
day-to-day levels of mercury in the hazardous waste over a three year 
period); or (2) a hazardous waste maximum theoretical emissions 
concentration (MTEC), expressed in units of [mu]g/dscm, developed by 
projecting emissions of the best performing sources assuming mercury 
concentrations in the hazardous waste were at the source's 99th 
percentile level in the commenter-submitted dataset. To identify the 
best performing sources, the commenter suggests selecting the five 
sources with the lowest median mercury concentrations in the dataset. 
For existing sources, the commenters' evaluation yields a hazardous 
waste feed concentration limit of 3.3 ppmw and a stack concentration 
emission limit of 150 [mu]g/dscm (rounded to two significant figures 
and considering mercury contributions only from the hazardous waste). 
For new cement kilns, the commenters recommend a mercury standard in 
the format of a hazardous waste feed concentration limit only, 
expressed in ppmw, based on the single source with the lowest 99th 
percentile level of mercury in hazardous waste. The commenters 
recommend a mercury standard of 1.9 ppmw for new sources.
    Response: We agree with commenters that the commenter-submitted 
dataset documenting the day-to-day levels of mercury in hazardous waste 
fuels fired to all hazardous waste burning cement kilns is the best 
available data to identify floor levels for existing and new cement 
kilns. See discussion in Part Four, Section I.D. However, we disagree 
with the commenters' suggested format of the mercury standard for 
existing sources. Establishing the mercury standard as the commenters' 
suggest (i.e., 3.3 ppmw in the hazardous waste feed or 150 [mu]g/dscm 
as a hazardous waste MTEC) fails to consider the interim mercury 
standards. As discussed in Part Four, Section III.E, there can be no 
backsliding from the levels of performance established in the interim 
standards. While not every source feeding hazardous waste with a 
maximum mercury concentration of 3.3 ppmw would exceed the interim 
standard, most sources using more than 50 percent hazardous waste as 
fuel (i.e., replacing at least half its fossil fuel with hazardous 
waste) would exceed the interim standard, emitting mercury higher than 
the levels allowed under Sec. Sec.  63.1204(a)(2) and 63.1206(b)(15) of 
the interim standards.\157\ The hazardous waste MTEC of 150 [mu]g/dscm 
calculated by the commenters is also higher than the level currently 
allowed under Sec.  63.1206(b)(15) of the interim standards. Since 
sources cannot backslide from the levels of the interim standards, if 
we were to accept the commenters' floor analysis results as presented 
(which we are not), then we would ``cap'' each calculated standard 
(i.e., 3.3 ppmw hazardous waste feed concentration and 150 [mu]g/dscm 
in stack emissions) at the interim standard level. This would result in 
a mercury standard for existing sources of 3.3 ppmw hazardous waste 
feed and a hazardous waste feed MTEC of 120 [mu]g/dscm or 120 [mu]g/
dscm as a stack gas concentration limit. We note this is similar to the 
mercury standard adopted today: a hazardous waste feed concentration 
limit of 3.0 ppmw and a hazardous waste feed MTEC of 120 [mu]g/dscm or 
120 [mu]g/dscm as a stack gas concentration limit. For an explanation 
of why we derived a level of 3.0 ppmw from the data, see Section 7.5.3 
of Volume III of the Technical Support Document.
---------------------------------------------------------------------------

    \157\ USEPA, ``Technical Support Document for HWC MACT 
Standards, Volume III: Selection of MACT Standards,'' Section 23.4, 
September 2005.
---------------------------------------------------------------------------

    The commenters' suggested new source mercury standard of 1.9 ppmw 
in the hazardous waste has the same deficiency. New sources with a 
hazardous waste fuel replacement rate of approximately 75% could emit 
mercury at levels higher than currently allowed under the interim 
standards. After capping the calculated standard at the interim 
standard level, we would identify the mercury standard for new sources 
as a hazardous waste concentration limit of 1.9 ppmw in the hazardous 
waste and a hazardous waste feed MTEC of 120 [mu]g/dscm or 120 [mu]g/
dscm as a stack gas concentration limit. For reasons discussed in 
Section 7.5.3 of Volume III of the Technical Support Document, this is 
indeed the mercury standard we are promulgating for new cement kilns.
    The commenters also suggest that the best performing sources should 
be identified as those with the lowest three-year median concentration 
of mercury in hazardous waste. Although this approach would be 
permissible, we conclude that it is more appropriate to identify the 
best performers (or single best performer for new sources) by

[[Page 59469]]

selecting those with the lowest 99th percentile upper level mercury 
concentrations. (This is not a statistically determined upper 
prediction limit; there is sufficient data for an arithmetically 
calculated 99th percentile to reliably reflect sources' performance.) 
We believe that this approach best accounts for the variability 
experienced by best performing sources over time.
    A detailed discussion of the MACT floor analysis for existing and 
new cement kilns is presented in Section 7.5.3 of Volume III of the 
Technical Support Document. In summary, the mercury standard for 
existing cement kilns is 3.0 ppmw in the hazardous waste feed and 120 
[mu]g/dscm as a hazardous waste maximum theoretical emission 
concentration feed limit or 120 [mu]g/dscm as a stack gas concentration 
limit. For new sources the mercury standard is 1.9 ppmw in the 
hazardous waste feed and 120 [mu]g/dscm as a hazardous waste maximum 
theoretical emission concentration feed limit or 120 [mu]g/dscm as a 
stack gas concentration limit.\158\
---------------------------------------------------------------------------

    \158\ Please note that we do not regard this standard as a work 
practice standard under section 112(h)(1) of the Act, because part 
of the standard includes an emission limit which is measured at the 
stack. EPA believes the special requirements of section 112(h)(1) 
apply when a work practice is the exclusive standard.
---------------------------------------------------------------------------

    Comment: Two commenters oppose EPA's proposed approach to base 
compliance with the mercury standard on averaged annual emissions. The 
commenters state an annual average would allow mercury emissions to 
exceed the interim standard because a source could burn high 
concentrations of mercury waste over a short period and still comply 
with an annual limit by burning low concentration wastes at other 
times. These commenters support the concept of a 12-hour rolling 
average feedrate limit (i.e., the current requirement under the interim 
standards) in conjunction with an emission standard no less stringent 
than the interim standard.
    Response: We agree with these comments. Cement kilns must establish 
a 12-hour rolling average feedrate limit of mercury to comply with 
these standards. The mercury standards for cement kilns are ``capped'' 
at the interim standard level to prevent backsliding from the current 
level of performance. This is accomplished by expressing the standard 
as a limit on the mercury concentration in the hazardous waste (with 
the rolling average) and either an emission concentration limit or 
hazardous waste maximum theoretical emission concentration feed limit. 
See Sec.  63.1209(l)(1)(iii).
2. Total Chlorine
    Comment: One commenter states that the proposed MACT floor approach 
is inconsistent with the statutory definition of MACT because EPA's 
selection of a routinely achievable system removal efficiency (SRE) was 
arbitrary and not representative of the best performing sources. 
Instead, the commenter suggests EPA identify a MACT SRE based on the 
five sources with the best SREs and apply that SRE to the MACT chlorine 
feed level. Later, in supplemental comments, the same commenter 
suggests two alternative approaches to identify a floor level. One 
approach applies a ranking methodology based on emissions and chlorine 
feed, and the second suggested approach applies a triple ranking method 
based on emissions, feed, and chlorine SRE. Other commenters, however, 
supported EPA's proposed approach.
    Response: We are adopting the same approach we proposed at 69 FR at 
21259. As we explained, this is a variant of the SRE/Feed approach, the 
variant involving the degree of system removal efficiency achieved by 
the best performing sources. In summary, to determine the floor level 
we first identify the best performing sources according to their 
hazardous waste chlorine feedrate. The best performing sources are 
those that have the lowest maximum theoretical emissions concentration 
(MTEC), considering variability. We then apply an SRE of 90 percent 
(the specific point in contention) to the best performing sources' 
total MTEC (i.e., thus evaluating removal of total chlorine across the 
entire system, including chlorine contributions to emissions from all 
feedstreams such as raw materials and fossil fuels) to identify the 
MACT floor, which is expressed as a stack gas emissions concentration 
in parts per million by volume. This approach defines the MACT floor as 
an emission level that the best performing sources could achieve if the 
source limits the feedrate of chlorine in the hazardous waste to the 
MACT level (i.e., the level achieved by the average of the best 
performing five sources) while also achieving an SRE that accounts for 
the inherent variability in raw material alkalinity and (to a lesser 
degree) cement kiln dust recycle rates, and production requirements. 69 
FR at 21259.
    Under this approach, we are evaluating hazardous waste feed control 
as we do for other sources. One commenter objects to our determination 
that an SRE of 90 percent is representative of the best performing 
sources because we have not established a MACT SRE--the average SRE 
achieved by the best performing sources.
    There is no doubt that the cement manufacturing process is capable 
of capturing significant quantities of chlorine when favorable 
conditions exist within the kiln system. Our usual approach of 
establishing an SRE by ranking the most efficient SREs taken from 
individual compliance tests, however, would result in a standard that 
would not be achievable because it may not be duplicable by the best 
performers or certainly would not be replicable by others, given that 
it is a function of various highly variable parameters, especially 
levels of alkali metals (e.g., sodium and potassium) and volatile 
compounds (e.g., chlorine and sulfur) in the raw materials. Alkalis and 
volatiles vary at a given best performer facility (in fact, at all 
facilities) as different strata are mined in the quarry, and across 
facilities due to different sources of raw materials. Raw material 
substitution is infeasible and counter to the objective of producing 
quality product (i.e., a product with low alkali content).
    Cement kilns thus are not able to design or operate to achieve a 
specific SRE at the high (most efficient) end of the range of test 
conditions. This is demonstrated by our calculations of system removal 
efficiency data, which is essentially a collection of performance 
``snapshots.'' See SRE data summarized in Table 1 at the end of this 
response; see also Mossville, 370 F. 3d at 1242 (maximum emission 
variability associated with raw material variability needs to be 
accounted for in MACT floor determination since the standard must be 
met at all times under all operating conditions). The performance data 
of the ``apparent'' best performers--upwards of 99 percent--identified 
by the commenter are simply a snapshot in the possible range of 
performance and are not replicable in the future due to factors which 
are uncontrollable by the source, as just explained. In confirmation, 
cement kilns achieving this level of removal in one test proved 
incapable of replicating their own result in other tests even though 
individual sources each have their own proprietary source of raw 
materials. See results in table for Giant (SC), Essroc (IN), Holcim 
(MO), Giant (PA), and LaFarge (KS) all

[[Page 59470]]

of whom would violate a 99 + percent standard based on their own 
operating results.

             Table 1.--Summary of System Removal Efficiency Data for Wet Process Cement Kilns \159\
----------------------------------------------------------------------------------------------------------------
                                                  Number Runs in    Low SRE Run    High SRE Run   Average SRE of
                    Facility                         Data Base          (%)             (%)        All Runs (%)
----------------------------------------------------------------------------------------------------------------
LaFarge (OH)....................................               3            99.1            99.4            99.3
Giant (SC)......................................              24            95.5            99.8            99.0
Essroc (IN).....................................              13            97.3            99.9            98.7
Holcim (MO).....................................               6            96.4            99.9            98.4
LaFarge (KS)....................................              12            95.7            99.3            98.1
Giant (PA)......................................              17            87.7            99.4            97.1
Continental (MO)................................               3            95.7            97.0            96.5
Ash Grove (AR)..................................              37            85.1            98.8            95.1
Texas Industries (TX)...........................               6            88.8            97.0            93.6
Holcim (MS).....................................               9            76.5            99.2            90.0
----------------------------------------------------------------------------------------------------------------
\159\ See Section 3.6 of Volume II (Specific MACT Standards) of Comment Response Document, September 2005.

    However, the data indicate that SRE is reasonably quantifiable to a 
point. Based on our data base of system removal efficiency information 
from 130 test conditions where total chlorine was evaluated, we 
conclude that a system removal efficiency of 90 percent is a reasonable 
estimate of MACT SRE.\160\
---------------------------------------------------------------------------

    \160\ As discussed a number of times earlier, we are not basing 
any standards on feed control of HAP in raw material and fossil fuel 
input. We instead are controlling HAP attributable to those inputs 
by means of end-of-stack emission standards which reflect removal of 
HAP by some type of control device. This approach is consistent with 
the discussion above, since we are not basing the cement kiln 
chlorine standard on control of any raw material input, but rather 
on some type of back-end removal efficiency.
---------------------------------------------------------------------------

    We also reject the commenter's three suggested alternative 
approaches to identify a MACT SRE to apply to the MACT feed level. The 
commenter's methods all suffer a common flaw: They fail to recognize 
and take into account the limitations of the total chlorine SRE data. 
For example, as just demonstrated, available data show that considering 
the SRE data associated with the most recent compliance test as a 
ranking factor will result in unachievable standards due to the varying 
effectiveness of chlorine capture (which impacts emissions) depending 
on the raw material mix characteristics. Considering only the most 
recent compliance test data as suggested yields results that are 
unachievable because the best performer's SRE data are likely biased 
high (e.g., sources that happen to test under favorable conditions are 
likely to be identified as best performers), which would not be 
replicable by even that source on a day-to-day basis.
3. Semivolatile and Low Volatile Metals
    Comment: Commenters oppose EPA's proposed approach to treat each 
kiln as a separate and unique source in the SRE/Feed MACT floor 
analysis for cement kilns.\161\ Commenters state that the approach is 
an improper way to perform a statistical analysis and reduces the 
variability in emissions that otherwise would be observed in a MACT 
pool of five unique sources. Variability is reduced because co-located 
kilns at the same plant share many of the factors that comprise front-
end and back-end controls. As a result, the calculated MACT floors for 
SVMs and LVMs for cement kilns are too stringent. The commenters' 
recommended solution (in instances where co-located kilns are among the 
top five performers) is to use only the data from the best performing 
co-located kiln, exclude any lesser performing kilns at the plant site, 
and then include the next-best performing non-co-located kiln in the 
MACT pool. Implementing their recommendation, the commenters state that 
the MACT floor for SVMs increases from 4.0 x 10<SUP>-4</SUP> to 7.4 x 
10<SUP>-4</SUP> lbs/MMBtu and the floor for LVMs increases from 1.4 x 
10<SUP>-5</SUP> to 1.8 x 10<SUP>-5</SUP> lbs/MMBtu. Another commenter 
generally supports EPA's approach noting that the variability factor 
applied to the emissions data already accounts for variability.
---------------------------------------------------------------------------

    \161\ It is common for cement manufacturing plants to operate 
multiple cement kilns at the same plant.
---------------------------------------------------------------------------

    Response: We consider sources that are not identical as unique 
sources and emissions data and information from unique sources are 
considered separate sources in the floor analyses. An example of an 
``identical'' source in our data base is compliance test data from a 
similar on-site combustion unit used in place of a compliance test for 
another unit (i.e., emissions testing of an identical unit was not 
conducted). These sources and their associated data are called ``data 
in lieu of'' sources in our data based on the RCRA provisions under 
Sec.  266.103(c)(3)(i). We acknowledge that co-located sources may in 
fact share certain similar operation features (e.g., use of raw 
material from the same quarry, use of the same coal and hazardous waste 
burn tank to fire the kilns); however, given that the co-located 
sources (except those designated as data in lieu of) are not designed 
identically, and given their hazardous waste feed control levels were 
not identical during testing, we conclude we must consider each source 
as a unique source in the floor analyses.\162\
---------------------------------------------------------------------------

    \162\ Nonetheless, we analyzed the SVM and LVM floors for cement 
kilns as suggested by the commenter. Results of the analysis are 
presented in ``Technical Support Document for HWC MACT Standards, 
Volume III: Selection of MACT Standards,'' Section 8.8, September 
2005.
---------------------------------------------------------------------------

    Comment: Commenter states that EPA's proposed standards for new 
cement kilns are unachievable due to problems with its accounting for 
variability, in part because EPA did not consider geographic 
differences when assessing feed control levels. The concentrations of 
hazardous constituents in the waste in a particular region are likely 
to be different than in the waste from another geographical region due 
to types of industrial sectors located within each region. Sources 
cannot reasonably arrange for transportation of lower HAP wastes 
generated across the country and cannot treat the hazardous waste to 
remove or reduce HAP concentrations. The commenter cites several court 
decisions that support their assertions. Commenter believes that while 
this represents a problem for developing both the new and existing 
source floors, it is a greater predicament for the new

[[Page 59471]]

source floor because this floor level is based on test data for only 
one source.
    Response: We are not obligated to account for varying hazardous 
waste feed control levels occurring because of differing HAP generation 
rates in different locations (for commercial sources), or because 
different production process types generate higher or lower levels HAP 
concentration wastes. Hazardous waste feed control is a legitimate 
control technology. The commenter seems to suggest that we should 
subcategorize low feeding sources and high feeding sources based on 
their hazardous waste feed control level. This would inappropriately 
subcategorize sources based on differing levels of controls, which we 
do not do. See 69 FR at 403 (January 5, 2004). Nonetheless, as 
previously discussed, the SRE/Feed methodology lessens the impact of 
feed control variations across commercial units because it results in 
fewer situations where best performing back-end controlled sources 
(from a particulate matter emissions perspective) cannot achieve the 
semivolatile and low volatile metal design levels and floors.
    For new source standards, the single best performing cement kiln 
sources for semivolatile metals and low volatile metals were not the 
lowest hazardous waste feed controlled source (both floors were based 
on sources with the fourth best, (i.e., lowest, hazardous waste feed 
control level). We therefore do not believe these sources are 
atypically low hazardous waste feeders relative to the other best 
performing sources in the existing source MACT pools.

C. Lightweight Aggregate Kilns

1. Mercury Standard
    Comment: One commenter, an operator of lightweight aggregate kilns 
subject to this rule, recommends that EPA establish the mercury 
standard for lightweight aggregate kilns at a hazardous waste feed 
concentration limit of 3.3 ppmw for existing sources and 1.9 ppmw for 
new sources, which is the same standard suggested in public comments by 
a trade organization representing hazardous waste burning cement kilns. 
The commenter notes that these mercury limits are appropriate for 
lightweight aggregate kilns because the commenter's two lightweight 
aggregate manufacturing facilities participate in the same hazardous 
waste fuel market as the majority of cement kilns. Moreover, the 
commenter maintains that its parent company also owns and operates two 
cement kilns and that its lightweight aggregate kilns receive hazardous 
waste from many of the same generators that provide hazardous waste 
fuel to the cement kilns. Consequently, the commenter states that the 
cement industry's data set of actual mercury feed concentrations in the 
hazardous waste best represents the full range of hazardous waste fuel 
concentrations that exist in the waste fuel market (see also Part Four, 
Sections I.D and E).
    Response: We disagree with the commenter. Although the cement 
industry's set of mercury feed concentration data in the hazardous 
waste may represent the full range of concentrations for the cement 
kiln source category, we cannot conclude the same for lightweight 
aggregate kilns because the commenter states that the mercury dataset 
are only applicable to its kilns.\163\ Further, the commenter provides 
no specific information or data to support the conclusion that its 
suggested approach is justified for the other lightweight aggregate 
kiln facility.
---------------------------------------------------------------------------

    \163\ We note that the commenter-submitted dataset is not 
amenable for use in establishing standards expressed in a thermal 
emission format because sufficient information on the 
characteristics of the hazardous waste (e.g., heating value of 
hazardous waste) were not provided.
---------------------------------------------------------------------------

    We also disagree with the commenter as to the appropriateness of 
establishing the mercury standard in the format of a hazardous waste 
feed concentration (i.e., 3.3 ppmw for existing sources and 1.9 ppmw 
for new sources) for lightweight aggregate kilns. A hazardous waste 
feed concentration standard is improper for this source category 
because one lightweight aggregate kiln facility's sources (although not 
the commenter's) controls mercury emissions using wet scrubbing. Thus, 
a hazardous waste feed concentration standard would inappropriately 
limit the mercury concentration in hazardous waste for sources that use 
control equipment capable of capturing mercury. A source with control 
equipment should not be restricted to a hazardous waste feed 
concentration standard that is based on sources that can only control 
mercury emissions through limiting the amount of mercury in the 
hazardous waste.
    In any case, as explained earlier in our discussion of cement kiln 
mercury standard, we believe that it is preferable to establish an 
emission standard to assure that the actual amount of mercury emitted 
by these sources is controlled by means of a numerical standard for 
stack emissions.
    Comment: One commenter agrees that a source may not be able to 
achieve the mercury standard due to raw material contributions that 
might cause an exceedance of the emission standard in spite of a source 
using properly designed and operated MACT floor control technologies, 
including controlling the levels of metals in the hazardous waste. The 
commenter opposes the proposed alternative standard of 42 [mu]g/dscm, 
which is expressed as a hazardous waste maximum theoretical emissions 
concentration. Instead, the commenter suggests that EPA maintain the 
alternative standard options of Sec. Sec.  63.1206(b)(15) or 
63.1206(b)(9).
    Response: We agree with the commenter that the mercury standard 
should address the concern of raw material contributions causing an 
exceedance of the emission standard. We also agree that the proposed 
alternative standard of a hazardous waste maximum theoretical emissions 
concentration of 42 [mu]g/dscm is an improper standard because the 
underlying data are unrepresentative. See discussion in Part Four, 
Section I.E. We note that the mercury standard promulgated today is 120 
[mu]g/dscm as a stack gas concentration limit or 120 [mu]g/dscm as a 
hazardous waste maximum theoretical emission concentration feed limit. 
The alternative mercury standard sought by the commenter under Sec.  
63.1206(b)(15) is a limit of 120 [mu]g/dscm as a hazardous waste 
maximum theoretical emission concentration, which is included in the 
mercury standard promulgated today. This should address the commenter's 
concern.
    Comment: One commenter supports a mercury standard with short-term 
compliance limits (e.g., 12-hour rolling average feedrate limits) as 
opposed to the annual limit proposed.
    Response: For reasons discussed in Part Four, Section I.E, we are 
using a different mercury dataset than at proposal. We solicited 
comment on a floor approach using these data in a notice \164\ sent 
directly to certain commenters. We are adopting that approach today. 
The monitoring requirements of the mercury standard for lightweight 
aggregate kilns includes short-term averaging periods (i.e., not to 
exceed a 12-hour rolling average), as recommended by the commenter.
---------------------------------------------------------------------------

    \164\ See docket item OAR-2004-0022-0370.
---------------------------------------------------------------------------

2. Total Chlorine Standard
    Comment: One commenter supports excluding from the floor analysis 
all lightweight aggregate kiln sources that lack air pollution control 
devices for chlorine, such as scrubbing technology. The floor analysis 
should simply exclude sources without back-end controls according to 
the commenter.

[[Page 59472]]

    Response: We disagree. For the final rule, we are using the SRE/
Feed MACT floor approach which defines best performers as those sources 
with the best combined front-end hazardous waste feed control and back-
end air pollution control efficiency. The commenter's suggestion would 
exclude emissions data from two of the three facilities in this source 
category even though valid emissions data from these sources are 
available (and therefore ordinarily to be used, see CKRC, 255 F. 3d at 
867), and these sources achieved the best front-end hazardous waste 
feed control in the category. We note that the best feedrate controlled 
sources have hazardous waste thermal feed levels that are approximately 
one-fifth the level of the source's with back-end controls. These data 
describe the level of performance of sources in the category and must 
be evaluated in the MACT floor analysis. We also note that even if we 
were to implement the commenter's suggestion, the MACT floor results 
would not change for existing and new lightweight aggregate kilns 
because the total chlorine emissions data of the source with back-end 
air pollution controls (after considering variability) are higher than 
the standards promulgated today. Thus, the commenter's suggestion also 
would result in a standard that would be capped by the interim 
standard.
3. Beyond-the-Floor Standards
    Comment: One commenter opposes EPA's proposed decision to 
promulgate a beyond-the-floor standard for dioxin/furans for existing 
and new lightweight aggregate kilns based on performance of activated 
carbon injection.
    Response: For the final rule, we conclude that a beyond-the-floor 
standard for lightweight aggregate kilns is not warranted. The Clean 
Air Act requires us to consider costs and non-air quality impacts and 
energy requirements when considering more stringent requirements than 
the MACT floor. In the proposed rule, we estimated that the incremental 
annualized compliance costs for lightweight aggregate kilns to achieve 
the beyond-the-floor standard would be approximately $1.8 million and 
would provide an incremental reduction in dioxin/furan emissions of 1.9 
grams TEQ per year (see 69 FR at 21262). At proposal we judged costs of 
approximately $950,000 per additional gram of dioxin/furan TEQ removed 
as justified, and, therefore, we proposed a beyond-the-floor standard. 
Since proposal, we made several changes to the dioxin/furan data base 
as the result of public comments. One implication of these changes is a 
lower national emissions estimate for dioxin/furans for lightweight 
aggregate kilns. We now estimate an incremental reduction in dioxin/
furan emissions of 1.06 grams TEQ per year with costs ranging between 
$1.6 and $2.2 million per additional gram of dioxin/furan TEQ removed. 
Based on these costs and consideration of the non-air quality impacts 
and energy requirements (including more waste generated in the form of 
spent activated carbon, and more energy consumed), we conclude that a 
beyond-the-floor standard for existing and new lightweight aggregate 
kilns is no longer justified. For an explanation of the beyond-the-
floor analysis, see Section 12.1.2 of Volume III of the Technical 
Support Document. We note that EPA also retains its authority under 
RCRA section 3005(c) (the so-called omnibus permitting authority) by 
which permit writers can adopt more stringent emission standards in 
RCRA permits if they determine that today's standards are not 
protective of human health and the environment.

D. Liquid Fuel Boilers

1. Mercury Standard Not Achievable When Burning Legacy Mixed Waste
    Comment: One commenter states that the proposed liquid fuel boiler 
mercury standard is not achievable by a commercial boiler, DSSI 
(Diversified Scientific Services, Inc.) that burns mercury-bearing low 
level radioactive waste that is also a hazardous waste (so-called 
`mixed waste') that was generated years ago (so-called, legacy waste). 
The waste is an organic liquid containing high concentrations of 
mercury. The boiler is equipped with a wet scrubber which provides good 
mercury control--93%, system removal efficiency according to the 
commenter.
    The commenter states that the proposed liquid fuel boiler mercury 
standard is not achievable using feedrate control and/or additional 
back-end control. Waste minimization is not an option because the waste 
has already been generated. Further, available national treatment 
capacity for mercury-bearing, low-level radioactive organic hazardous 
waste is very limited. The only other hazardous waste combustion 
facility authorized to treat such waste is the Department of Energy 
incinerator at Oak Ridge, Tennessee. Waste treatment volumes at that 
facility are restricted by the mercury feed rate limitation for the 
incinerator. In addition, the feedrate of the waste cannot be 
practicably reduced because of the large back-log of waste that must be 
treated.
    The commenter suggests that their boiler be subject to the 
incinerator mercury standard because the mixed waste has far higher 
concentrations of mercury than wastes burned by other boilers and, as a 
consequence, the boiler is more incinerator-like with respect to the 
feedrate of mercury.
    Response. We agree with the commenter's suggestion. The final rule 
subjects this commercial liquid fuel boiler to the mercury standard for 
incinerators. We are classifying this source as a separate type of 
source for purposes of the mercury standard, because the type of 
mercury-containing waste it processes is dramatically different from 
that processed by other liquid fuel boilers, effectively making this a 
different type of source for purposes of a mercury standard \165\. The 
source thus feeds mercury at concentrations exceeding that of any 
boiler but at concentrations within the range processed by hazardous 
waste incinerators. The maximum test condition average MTEC \166\ for 
mercury for the remaining liquid fuel boilers is 20 [mu]g/dscm. All the 
liquid fuel boiler mercury data represent ``normal'' data, i.e., data 
that were not spiked. (The lack of spiked data in the liquid fuel 
boiler data base, in and of itself, indicates that these sources do not 
process mercury-bearing waste and do not need the operational 
flexibility gained by spiking to account for occasional higher 
concentration mercury wastes.) DSSI's 2002 mercury test condition 
average MTEC was spiked to 3500 [mu]g/dscm. In other words, DSSI needs 
the operational flexibility to feed 175 times more mercury than any 
other liquid fuel boiler. Incinerators, on the other hand, had mercury 
MTECs that ranged to 110,000 [mu]g/dscm in 2002. In fact, DSSI's 
mercury feed rate is the eighth highest of the 40 incinerators, 
including DSSI, for which we have 2002 mercury feed rate data. DSSI's 
process feed is thus within the upper range of mercury feed found at 
incinerators.
---------------------------------------------------------------------------

    \165\ See CAA section 112 (d) (1)), authorizing EPA to 
distinguish among different ``types * * * of sources within a 
category or subcategory'' in developing MACT standards.
    \166\ Maximum theoretical emission concentration is the feedrate 
normalized by gas flowrate assuming zero system removal efficiency.
---------------------------------------------------------------------------

    We believe it is well within the broad discretion accorded us in 
section 112(d)(1) to subcategorize among ``types'' and ``classes'' of 
sources within a category. See also Weyerhaeuser v. Costle, 590 F. 2d 
at 254, n. 70 (D.C. Cir. 1978) (similar raw waste characteristics 
justify common classification) and Chemical Manufacturers Ass'n v. EPA, 
870 F. 2d 177, 253-54 and n. 340 (5th

[[Page 59473]]

Cir. 1989) (same). We note that this boiler will be subject to the 
liquid fuel boiler standards for all HAP other than mercury (the only 
HAP where the issue of appropriate classification arises).
    Not surprisingly, given the disparity in waste concentration 
levels, the DSSI boiler, even though equipped with back end control 
comparable to best performing commercial incinerators, achieves mercury 
emission levels less than an order of magnitude higher than the other 
hazardous waste-burning liquid fuel boilers, few of which use back end 
control that is effective for mercury.\167\ This emission disparity 
likewise indicates that DSSI is treating a different type of waste than 
other liquid fuel boilers.
---------------------------------------------------------------------------

    \167\ USEPA, ``Technical Support Document for HWC MACT 
Standards, Volume I: Description of Source Categories,'' September 
2004, Section 2.4.4.
---------------------------------------------------------------------------

    The nature of the mercury-bearing waste further confirms that it is 
of a different type than that processed by other hazardous waste 
burning liquid fuel boilers. The waste is a remediation waste, a type 
of waste burned routinely by commercial hazardous waste incinerators 
but almost never by a liquid fuel boiler.
    Moreover, the waste is a legacy, mixed waste generated decades ago 
in support of the United States' strategic nuclear arsenal. It is not 
amenable to the types of control all other liquid fuel boilers use to 
reduce mercury emissions--some type of feed control or other 
minimization technique. We investigated whether any waste minimization 
options are feasible for this waste, and find that they are not. 
Normally, waste minimization is accomplished by one of three means: 
eliminating the use of mercury in the process to prevent it from being 
in the waste; pretreating the waste before burning to remove the 
mercury; or sending it to another facility better suited to handle the 
waste. Changing the production process to eliminate or reduce the 
mercury content of the waste is not an option because this waste has 
already been generated. Pretreatment is already practiced to the 
maximum extent feasible by settling out and separating the heavier 
mercury from the liquid components after thermal desorbtion. The 
remaining organic liquid that is burned by the mixed waste boiler 
contains concentrations of mercury (in organo-mercury and other organic 
soluble forms) that are orders of magnitude higher than burned by other 
liquid fuel boilers. Much of the waste cannot be feasibly pretreated to 
remove mercury because this legacy, mixed waste comes from many highly 
diverse sources. It is not practical or feasible to investigate how to 
remove the mercury from wastes of such varied and unique origins.
    Only one other facility could potentially treat this mixed waste, 
DOE's incinerator at Oak Ridge, Tennessee, whose permit allows the 
incinerator to manage mixed waste. However, waste treatment volumes for 
mercury-bearing wastes at that facility are restricted by the mercury 
feed rate limitation in the incinerator's permit. The DOE incinerator 
alone cannot assure national capacity for mercury-bearing, low-level 
radioactive organic hazardous waste. In addition, the back-end emission 
controls of the mixed waste boiler are superior to those used by most 
incinerators, including the Oak Ridge incinerator. This boiler uses a 
highly effective wet scrubbing system--the principal MACT floor back-
end control for mercury used by incinerators--that achieves over 93% 
system removal efficiency. This is superior control compared to most 
incinerators, including the one at Oak Ridge which achieves 75 to 85% 
removal.\168\
---------------------------------------------------------------------------

    \168\ For more explanation concerning mixed waste sources, 
limitations on the concentrations of mercury fed to these sources, 
and the system removal efficiency achieved, see USEPA, ``Technical 
Support Document for HWC MACT Standards, Volume III: Selection of 
Standards,'' September 2005, Section 8.7.
---------------------------------------------------------------------------

    Thus, this mixed waste boiler is reasonably classified a different 
type of source with respect to mercury waste than other hazardous 
waste-burning liquid fuel boilers, based on the nature of the waste 
burned and confirmed by the source's mercury emissions. We note that, 
although the final rule subjects only the DSSI mixed waste boiler to 
the incinerator mercury standard, we would conclude that any other 
liquid fuel boiler with the same fact pattern (i.e., that met the same 
criteria as the DSSI boiler as discussed above) should also be subject 
to the incinerator mercury standard rather than the liquid fuel boiler 
mercury standard.
    Comment. One commenter states that EPA's standards for all sources 
must reflect the actual emission levels achieved by the relevant best 
sources. If EPA wishes to subject the boiler source and incinerators to 
the same emission standards, however, it is entirely within the 
Agency's power to do so.
    Response. We agree. There is no functional difference between this 
boiler and incinerators with respect to mercury feed rate and the type 
of waste processed (incinerators often treat remediation wastes). 
Therefore, the most relevant sources for the purposes of clarification 
in this case are incinerators, not liquid fuel boilers.
    Accordingly, we have classified DSSI as an incinerator for purposes 
of a mercury standard (i.e., made it subject to the mercury standard 
for incinerators), and have included the DSSI mercury data with the 
incinerator data when assessing mercury standards for incinerators.
    Comment. In something of a contradiction, the same commenter argues 
that the mixed waste boiler source (DSSI) does not claim that it cannot 
meet the relevant mercury standard for liquid fuel boilers, but only 
that it cannot do so ``using either feedrate control or MACT floor back 
end emission control.'' Floors must reflect the emission levels that 
the relevant best sources actually achieve, not what is achievable 
through the use of a chosen emission control technology. It is flatly 
unlawful--and essentially contemptuous of court--for EPA even to 
entertain the source's argument that the source should be subject to a 
less stringent emission standard based on the levels they believe would 
be achievable through the use of one chosen control technology.
    The commenter also states that the source acknowledges that it 
could achieve a better emission level, and apparently meet the relevant 
standards, by using activated carbon. Their argument that doing so 
would generate large quantities of spent radioactive carbon does not 
support its attempt to avoid Clean Air Act requirements; the 
alternative to the source accumulating large quantities of radioactive 
carbon is releasing large quantities of radioactive and toxic pollution 
into the environment.
    Response. DSSI cannot meet the liquid boiler mercury standard 
because it burns a unique waste that resembles wastes processed by 
hazardous waste incinerators (in terms of mercury concentration and 
provenance) and is unlike any mercury-containing waste burned by the 
remaining liquid fuel boilers. See the earlier discussion showing that 
DSSI needs the operational flexibility to feed 175 times more mercury 
than any other liquid fuel boiler, but that DSSI's process feed is 
within the upper range of mercury feed found at incinerators.
    We agree that DSSI is processing different types of mercury-bearing 
wastes than those combusted by all other liquid fuel boilers. We 
believe that establishing a different mercury standard for DSSI is 
warranted, as it would for any source with demonstrably unique, 
unalterable feedstock which is

[[Page 59474]]

more difficult to treat than that processed by other sources otherwise 
in the same category.
    How DSSI chooses to comply with the incinerator mercury standard 
(for example, whether it must use some other type of emissions control 
technology) is not germane to this decision. We note that today's 
mercury standard for incinerators will force this source to lower its 
mercury emissions, since it is unlikely that it can meet today's 120 
[mu]g/dscm standard at all times without some changes in operations.
    Comment. The source argues that waste minimization is not feasible 
for legacy mixed waste that has already been generated. It is not 
possible to travel back in time and unmake mixed legacy waste that 
already has been created. That obvious fact, however, lends no support 
to their argument that it should be allowed to burn mixed legacy waste 
with less stringent emission standards, according to one commenter.
    Response. As discussed above, the mercury standard for liquid fuel 
boilers is not achievable for this source because it is a different 
type and class of boiler, based on the type of mercury-containing 
hazardous waste it processes. Because this boiler has mercury feed 
rates that resemble those of incinerators--not liquid fuel boilers--and 
waste minimization is not possible, subjecting the boiler to the 
mercury incinerator standard is a reasonable means of sub-
categorization pursuant to the discretionary authority provided us by 
section 112(d)(1) of the Clean Air Act.
    Comment. The commenter states that it is entirely possible to 
dispose of mixed legacy waste without burning it. Specifically, 
currently available technologies such as chemical oxidation and 
precipitation can be used to treat mixed legacy waste without burning 
it--and without releasing mercury into the air. Therefore, mixed legacy 
waste should not be burned at all; it should be disposed of safely 
through the application of one of these more advanced technologies.
    Response. First, these wastes must be treated before they can be 
land disposed. RCRA sections 3004(d), (g)(5), and (m). They also must 
meet a standard of 0.025 mg/l measured by the Toxicity Characteristic 
Leaching Procedure before land disposal is permissible. 40 CFR 268.40 
(standard for ``all other nonwastewaters that exhibit the 
characteristic of toxicity for mercury'').\169\ EPA's technical 
judgment is that it would be very difficult to meet this standard by 
any means other than combustion. Moreover, as an organic liquid, the 
waste is readily amenable to treatment by combustion. In addition, 
combustion is a legal form of treatment for the waste. EPA did not 
propose to change or otherwise reconsider these treatment standards in 
this rulemaking, and is not doing so here. We note, however, that 40 
CFR 268.42 and 268.44 provide means by which generators and treatment 
facilities can petition the Agency to seek different treatment 
standards from those specified by rule, and set out requirements for 
evaluating such petitions.
---------------------------------------------------------------------------

    \169\ Although the legacy waste that DSSI is burning is 
nominally classified as a nonwastewater due to its high organic 
content, it is in fact a liquid matrix, meaning that the treatment 
standard of 0.025 [mu]g/l is effectively a total standard.
---------------------------------------------------------------------------

    We note further that, because this waste is radioactive, 
exceptional precautions need to be taken in its handling. The 
nonthermal treatment alternatives mentioned by the commenter ignore the 
potential for radiation exposure if nonthermal treatment is used. 
Concerns (some of which are mentioned in DSSI's comment) include: 
Nonthermal treatment would (or could) increase worker exposure; desire 
to reduce handling of radioactive materials in general; need to avoid 
contaminating equipment that subsequently requires decontamination or 
handling as radioactive material; minimizing the generation of 
additional radioactive waste residues; reducing the amount of analysis 
of radioactive materials, which causes potential exposure, generation 
of radioactive wastes and equipment; wastes are varied and often of 
small volumes, which makes it difficult to develop routine procedures. 
Nonthermal treatment alternatives are also not currently available to 
DOE to manage the diversity and volume of DOE mixed waste. It is thus 
our belief that the commenter has not fully explored the implications 
of its position, especially with regard to radiation exposure.
    If the commenter wishes to pursue this issue, EPA believes the 
appropriate context is through the Land Disposal Restriction mechanisms 
described above.
    Comment. The commenter states that the source argues that feedrate 
control is not ``practical.'' There appears to be no record evidence 
indicating what would make feedrate control impractical and why any 
such obstacle could not be overcome.
    Response. Feedrate control to the extent necessary to achieve the 
liquid fuel boiler standards is not practical for reasons just 
discussed. This source is one of two available sources that is 
authorized to treat mixed waste, and the other source is not likely to 
have the ability to burn mercury-bearing organic waste in the future 
due to permit limitations and size constraints.
    Comment. The commenter states that mixed legacy waste should not be 
burned at all. If there are truly no other facilities that are 
currently permitted to dispose of mixed legacy waste, such waste should 
be stored until a facility that can treat such waste safely--e.g., 
through chemical oxidation--can be permitted.
    Response. The commenter's suggestion is beyond the scope of today's 
rulemaking. The suggestion is also illegal, since RCRA prohibits the 
storage of hazardous waste for extended periods. See RCRA section 
3004(j); and Edison Electric Inst. v. EPA, 996 F. 2d 326, 335-37 (DC 
Cir. 1993) (illegal under RCRA section 3004(j) to store hazardous waste 
pending development of a treatment technology). EPA also notes that it 
retains authority under RCRA section 3005(c) (the so-called omnibus 
permitting authority) by which permit writers can adopt more stringent 
emission standards in RCRA permits if they determine that today's 
standards are not protective of human health and the environment.
2. Different Mercury, Semivolatile Metals, Chromium, and Total Chlorine 
Standards for Liquid Fuel Boilers Depending on the Heating Value of the 
Hazardous Waste Burned
    Comment. Several commenters state that liquid fuel boilers should 
have an alternative concentration-based standard in addition to the 
thermal emission-based standard. Liquid fuel boilers are typically 
``captive'' units that burn waste fuels generated from on-site or 
nearby manufacturing operations, rather than accepting wastes from a 
wide variety of other sources. Because they have captive fuel sources, 
operators generally do not have fuel blending capabilities. Liquid fuel 
boilers ``burn what they have,'' and as such have very limited 
operational flexibility. EPA should not penalize boilers that have the 
same mass concentrations of metals or chlorine in their waste compared 
to other boilers, but which wastes have a lower heating value than 
wastes burned by other boilers. (The ``penalty'' is that emissions 
limits that are normalized by the heating value of the hazardous waste 
require that less volume of lower heating value waste can be burned 
compared to higher heating value fuel.) This problem is made worse by 
the limited data base for liquid fuel boilers,

[[Page 59475]]

the lack of historical data to verify that these standards are 
achievable over time, and having most or all of the measured emissions 
below detection limits. In addition, most of the mercury and 
semivolatile metal data EPA has in the data base were obtained during 
normal operations and while the source demonstrated compliance with 
RCRA's chromium standard--the other metals data were available only 
because stack method Method 29 reports data for all RCRA metals, even 
ones that are not at issue for the compliance test. (Sources generally 
elected to comply with the BIF Tier I metals emissions levels, but Tier 
III for chromium. Thus, the Method 29 test for chromium will give 
emissions results for all the metals--even those not subjected to stack 
testing--not just chromium.)
    Response. As explained earlier in Part Four, Section V.A., EPA has 
selected normalizing parameters that best fit the input to the 
combustion device. A thermal normalizing parameter (i.e., expressing 
the standards in terms of amount of HAP contributed by hazardous waste 
per thermal content of hazardous waste) is appropriate where hazardous 
waste is being used in energy-recovery devices as a fuel, since the 
waste serves as a type of fuel. Using a thermal normalizing parameter 
in such instances avoids the necessity of subcategorizing based on unit 
size.
    The commenters raise the other side of the same issue. As the 
commenters point out, some liquid fuel boilers burn lower Btu hazardous 
waste because that is the waste available to them, and those with waste 
that has a low heating value are, in their words, ``penalized,'' 
compared to those with a high(-er) heating value. Also, since these are 
not commercial combustion units, they normally lack the opportunity to 
blend wastes of different heating values to result in as-fired high 
heating value fuels. If boiler standards are normalized by hazardous 
waste heating value, sources with lower heating value waste must either 
reduce the mass concentration of HAP or increase the waste fuel heating 
value (or increase the system removal efficiency) compared to sources 
with wastes having the same mass concentration of HAP but higher 
heating value.
    Moreover, the thermal normalizing parameter is not well suited for 
a hazardous waste that is not burned entirely for its fuel value. In 
cases where the lower heating value waste is burned, the boiler is 
serving--at least in part--as a treatment device for the lower heating 
value hazardous waste. When this occurs, the better normalizing 
parameter is the unit's gas flow (a different means of accounting for 
sources of different size), where the standard is expressed as amount 
of HAP per volume of gas flow (the same normalizing parameter used for 
most of the other standards promulgated in today's final rule.)
    The commenters requested that liquid fuel boilers be able to select 
the applicable standard (i.e., to choose between normalizing 
parameters) and further requested that we assess the performance of 
these units (for the purpose of establishing concentration-based MACT 
floor levels) by using the same MACT pool of best performing sources 
expressed on a thermal emissions basis.
    Neither of these suggestions is appropriate. Choice of normalizing 
parameter is not a matter of election, but rather reflects an objective 
determination of what parameter is reasonably related to the activity 
conducted by the source. Moreover, the commenter's suggestion to use 
thermal emissions to measure best performance for a concentration-based 
standard does not make sense. It arbitrarily assumes that the best 
performers with respect to low and high heating value wastes are 
identical.
    Instead, we have established two subcategories among the liquid 
fuel boilers: those burning high and those burning low heating value 
hazardous waste. The normalizing parameter for sources burning lower 
energy hazardous waste is that used for the other hazardous waste 
treatment devices, gas flow rate, so that the standard is expressed as 
concentration of HAP per volume of gas flow (a concentration-based form 
of the standard.) The normalizing parameter for sources burning higher 
energy content hazardous waste is the thermal parameter used for energy 
recovery devices, such as cement kilns and lightweight aggregate kilns. 
For the purposes of calculating MACT floors, the best performers are 
then drawn from those liquid fuel boilers burning lower energy 
hazardous waste for the lower heating value subcategory, and from those 
liquid fuel boilers burning higher energy hazardous waste for the 
higher heating value subcategory \170\. (See Section 23.2 of Volume III 
of the Technical Support Document for more information.)
---------------------------------------------------------------------------

    \170\ We also agree that liquid fuel boilers present several 
unique circumstances, namely: they are often unable to blend fuel 
and have limited operational flexibility as a result; our data base 
on these sources' performance is relatively small; much of our 
mercury and semivolatile metals data is at or near detection limits; 
and much of the mercury and semivolatile metals data was obtained 
for other purposes, namely from risk burns or as a result of Method 
29 testing to demonstrate compliance with a RCRA chromium standard. 
While not immediately important to the topic at hand--namely that 
not all liquid fuel boilers burn for energy recovery--they are 
secondary issues that we need to closely consider to make sure we do 
not estimate what the best performing 12% of sources are achieving 
in an unreasonable manner.
---------------------------------------------------------------------------

    Moreover, liquid fuel boilers are not irrevocably placed in one or 
the other of these subcategories. Rather, the source is subject to the 
standard for one or the other of these subcategories based on the as-
fired heating value of the hazardous waste it burns at a given time. 
Thus, when the source is burning for energy recovery, then the thermal 
emissions-based standard would apply. When the source is burning at 
least in part for thermal destruction, then the concentration based 
standard would apply. This approach is similar to how we have addressed 
the issue of normalization in other rules where single sources switch 
back and forth among inputs which are sufficiently different to warrant 
separate classification. \171\
---------------------------------------------------------------------------

    \171\ See NESHAP for Stationary Combustion Turbines, 40 CFR 
section 63.6175 (definitions of ``diffusion flame gas-fired 
stationary combustion turbine'', ``diffusion flame oil-fired 
stationary combustion turbine'', ``lean pre-mix gas-fired stationary 
combustion turbine'' and ``lean premix oil-fired stationary 
combustion turbine'').
---------------------------------------------------------------------------

    We next considered what an appropriate as-fired heating value would 
be for each liquid fuel boiler subcategory. Although we have used 5000 
Btu/lb (the heating value of lowest grade fuels such as scrap wood) in 
past RCRA actions as a presumptive measure of when hazardous waste is 
burned for destruction (see, e.g. 48 FR 11159 (March 16, 1983)), we do 
not think that measure is appropriate here. We used the 5,000 Btu/lb 
level to delineate burning for destruction from burning for energy 
recovery at a time when that determination meant the difference between 
regulation and nonregulation. See 50 FR 49166-167 (Nov. 29, 1985). This 
is a different issue from choosing the most reasonable normalizing 
parameter for regulated units (i.e., units which will be subject to a 
standard in either case).
    Instead, we are adopting a value of 10,000 Btu/lb as the threshold 
for subcategorization. This is approximately the heating value of 
commercial liquid fossil fuels. 63 FR 33782, 33788 (June 19, 1998) It 
is also typical of current hazardous waste burned for energy recovery. 
Id. Moreover, EPA has used this value in its comparable fuel 
specification as a means of differentiating fuels from waste. See id. 
and Table 1 to 40 CFR section 261.38, showing that EPA normalizes all

[[Page 59476]]

constituent concentrations to a 10,000 Btu/lb level in its 
specification for differentiating fuels from wastes.
    We next examined the waste fuel being burned at cement kilns and 
lightweight aggregate kilns, which burn hazardous waste fuels to drive 
the process chemistry to produce products\172\, to cross-check whether 
10,000 Btu/lb is a reasonable demarcation value for subcategorizing. 
10,000 Btu/lb is the minimum heating value found in burn tank and test 
report data we have for cement kilns and lightweight aggregate kilns 
\173\. We believe the cement kiln and light weight aggregate kiln data 
confirm that this is an appropriate cutpoint, since these sources are 
energy recovery devices that blend hazardous wastes into a consistent, 
high heating value fuel for energy recovery in their manufacturing 
process.
---------------------------------------------------------------------------

    \172\ The Norlite light-weight aggregate kiln was not included 
in this analysis because they claim they are not burning for energy 
recovery. The waste Norlite burns is 4,860 Btu/lb or lower. This is 
indicative of a source burning solely for thermal treatment of the 
waste and not, at least in part, for energy recovery. See 40 CFR 
266.100(d)(2)(ii).
    \173\ The cement kiln burn tank data and test report data shows 
the minimum heating values of 9,900 and 10,000 Btu/lb, respectively, 
for the hazardous waste. The minimum lightweight aggregate kiln 
heating values for hazardous waste was 10,000 Btu/lb, excluding the 
Norlite source.
---------------------------------------------------------------------------

    We then separated the liquid fuel boiler emissions data we had into 
two groups, sources burning hazardous waste fuel with less than 10,000 
Btu/lb and all other liquid fuel boilers, and performed separate MACT 
floor analyses. (See Sections 13.4, 13.6, 13.7, 13.8, and 22 of Volume 
III of the Technical Support Document.) We calculated concentration-
based MACT standards for these sources from their respective mercury, 
semivolatile metals, chromium, and total chlorine data.
    Liquid fuel boilers will need to determine which of the two 
subcategories the source belongs in at any point in time. Thus, you 
must determine the as-fired heating value of each batch of hazardous 
waste fired so that you know the heating value of the hazardous waste 
fired at all times.\174\ If the as-fired heating value of hazardous 
wastes varies above and below the cutpoint (i.e., 10,000 Btu/lb) at 
times, you are subject to the thermal emissions standards when the 
heating value is not less than 10,000 Btu/lb and the mass concentration 
standards when the heating value is less than 10,000 Btu/lb. To avoid 
the administrative burden of frequently switching applicable operating 
requirements between the subcategories, you may elect to comply with 
the more stringent operating requirements that ensure compliance with 
the standards for both subcategories.
---------------------------------------------------------------------------

    \174\ If you burn hazardous waste in more than one firing 
nozzle, you must determine the mass-weighted average heating value 
of the as-fired hazardous waste across all firing nozzles.
---------------------------------------------------------------------------

    Comment: EPA's attempt to give actual performance two different 
meanings within a single floor approach is unlawful, unexplained, 
internally inconsistent, and arbitrary. If EPA believes that mass-based 
emissions constitute sources' actual performance, the best performing 
sources must be those with the best mass based emissions--not thermal 
emissions.
    Response: As just explained, we agree with this comment, and have 
developed MACT floors independently for the two subcategories of liquid 
fuel boilers. Thus, we have defined two separate MACT pools based on 
the thermal input of the waste fuel and derived two separate and 
consistent MACT standards for sources when they burn solely for energy 
recovery, and when they do not.
    We also note that a source cannot ``pick and choose'' the less 
stringent of the two standards and comply with those. The source must 
be in compliance with the set of standards that apply.
3. Alternative Particulate Matter Standard for Liquid Fuel Boilers
    Comment: A commenter requested that EPA establish standards that 
allow boilers the option to comply with either a concentration-based 
particulate matter standard or thermal emissions-based particulate 
matter standard.
    Response: We determined that it is appropriate to express the 
particulate matter emission standard as a concentration-based standard 
consistently across source categories and not to give boilers the 
option to comply with a thermal emissions-based particulate matter 
standard. As discussed in Part Four, Section III.D as well as the 
preceding section, metal and chlorine concentration-based emission 
standards can be biased against sources that process more hazardous 
waste (from an energy demand perspective), in part because the SRE/Feed 
methodology assesses feed control of each source when identifying the 
best performing sources; the ranking procedure thus favors sources with 
lower percentage hazardous waste firing rates (keeping all other 
assessment factors equal). The thermal emission standard format 
eliminates this firing rate bias, which amounts to a limitation on the 
amount of raw material (hazardous waste fuel to an energy recovery 
device) that may be processed, when identifying best performing 
sources.
    The methodology we use to identify best performing sources for 
particulate matter emissions is not affected by the firing rate bias in 
the manner that metal and chlorine emissions are. This is primarily 
because we define best performing sources as those with the best back-
end air pollution control technology; feed control is not assessed 
(specifically ash feed control) for raw materials, fossil fuel, or 
unenumerated HAP metal in the hazardous waste. The hazardous waste 
firing rate bias is therefore not present when we identify the best 
performing particulate matter sources because a source's hazardous 
waste firing rate is not a direct factor in the ranking procedure.
    We also note that four of the nine best performing liquid fuel 
boilers for particulate matter are equipped with fabric filters. 
Particulate matter emissions from sources equipped with fabric filters 
are not significantly affected by ash inlet loading. This is not true 
for metals and chlorine, given metal and chlorine emissions from fabric 
filters tend to increase at increased feed rates. See Volume III of the 
Technical Support Document, Sections 5.3 and 7.4. We conclude that the 
hazardous waste firing rate issue is not a concern for these sources 
given their particulate matter emissions would not be significantly 
affected by increased hazardous waste firing rates.
4. Long-term, Annual Averaging Is Impermissible
    Comment: Standards expressed as long-term limits are legally 
impermissible because those levels, by definition, would sometimes be 
greater than the average emission levels achieved by the best 
performing sources. Compliance also must be measured on a continuous 
basis, under section 302(k) of the Act. Thus, floor levels (and 
standards) for mercury expressed as long-term limits are illegal.
    Response: The commenter maintains that the statutory command in 
section 112(d)(3)(A) to base floor standards for existing sources on 
``the average emission limitation achieved by the best performing 12 
percent of * * * existing sources'' precludes establishing standards 
expressed as long term averages because certain daily values could be 
higher. We do not accept this position. The statute does not state what 
type of ``average'' performance EPA must assess. Long term, i.e., 
annual, averaging of performance is quite evidently a type of average, 
and so is permissible under the statutory text. Moreover, it is 
reasonable to establish

[[Page 59477]]

standards on this basis (the standards being the average of the best 
performing sources, expressed as a long-term average), where sufficient 
data exist. Indeed, since the principal health concern posed by the 
emitted HAP is from chronic exposure (i.e. cumulative exposure over 
time), long-term standards (which reduce the long-term distribution of 
emitted HAP) arguably would be preferable in addressing the chief risks 
posed by these sources' emissions.
    We establish standards with long-term averaging limits whenever we 
use normal data to estimate long-term performance. We do this in the 
few instances where there are insufficient data (whether normal data or 
compliance test data) to estimate each source's short term emission 
levels (e.g., mercury and semivolatile metal standards for liquid fuel 
boilers).\175\ One or two snapshot data based on normal operations are 
not likely to reflect a source's short-term operating levels in part 
because feed control levels can vary over time.\176\ See Mossville, 370 
F. 3d at 1242 (varying feed rates lead to different emission levels, 
and this variability must be encompassed within the floor standard 
because the standard must be met at all times). As a result, snapshot 
normal emissions, when averaged together, better reflect a source's 
long term average emissions. An emission standard based on normal data 
that is averaged together, but expressed as a short-term limit, would 
not be achievable by the best performing sources because it would not 
adequately account for their emissions variability. See National 
Wildlife Federation v. EPA, 286 F. 3d at 572-73 (``[c]ontinuous 
operation at or near the daily maximum would in fact result in 
discharges that exceed the long-term average. Likewise, setting monthly 
limitations at the 99th percentile would not insure that the long-term 
average is met''). Long-term limits better account for this variability 
because such limits allow sources to average their varying feed control 
levels over time while still assuring average emissions over this 
period are below the levels demonstrated by the best performing 
sources.
---------------------------------------------------------------------------

    \175\ Two emission standards in this rulemaking are based on 
normal data but are expressed as short term limits (the mercury 
standards for lightweight aggregate and cement kilns). However, in 
these instances we had enough normal data to reasonably estimate 
each source's maximum emissions, thus allowing us to express the 
standard as a short term limit. See USEPA, ``Technical Support 
Document for HWC MACT Standards, Volume III: Selection of MACT 
Standards,'' September 2005, Sections 11.2 and 12.2.
    \176\ This is not the case for floors that are based on 
compliance tests because sources spiked their hazardous wastes to 
account for variability in hazardous waste feedrate. See Part Four, 
Section III.C above. Normal data, however, are a snapshot of what 
occurred on that day and are not likely to be representative over 
the long term, especially for mercury and semivolatile metals for 
liquid fuel boilers, where these limited data were almost entirely 
below the analytic detection limit.
---------------------------------------------------------------------------

    Indeed, under the commenter's approach where no averaging of intra-
source data would be allowed, sources would not be in compliance with 
the standards during the performance tests themselves. The tests 
consist of the average of three data runs, so half of the emissions-
weighted data points would be impermissibly higher than the average 
during the test used to derive today's emission standards.
    EPA also does not see that section 302(f) of the Act, cited by the 
commenter, supports its position. That provision indicates that the 
emission standards EPA establishes must limit the quantity, rate, or 
concentration of air pollutants on a continuous basis. A standard 
expressed as a long-term average does so by constraining the overall 
distribution of emissions to meet a long-term average. Also, long term 
limits result in emission standards that are lower than those that 
otherwise would be implemented on a short-term basis. The short-term 
limit would have to reflect the best performing sources' short term 
emissions variability (i.e., the maximum amount of variability a source 
could experience during a single test period). National Wildlife 
Federation, 286 F. 3d at 571-73.
    Comment: Other commenters argued the opposite point, that ERA has 
no data to show that an annual average is achievable, and EPA should 
establish a longer averaging period.
    Response: We believe that all sources can achieve the mercury and 
semivolatile metals standards for liquid fuel boilers on an annual 
basis using some combination of MACT controls, i.e., feed control, back 
end control, or some combination of both. We agree that we have a small 
data set for these standards, but also believe that it is intuitive 
that a liquid fuel boiler can meet these standards on an annual basis, 
because one year is sufficiently more than any seasonal (i.e., several 
month long) production of certain items that may not be represented by 
the tests we have.
    This informs us that an average of less than a year may not be 
achievable. It does not inform us that averaging of more than a year is 
required, since variations that occur with a year are averaged 
together. An annual average is sufficient for a source to determine 
whether an individual waste stream impacts negatively on the compliance 
of the liquid fuel boiler and take measures to address the issue.
5. Gas Fuel Boilers
    Comment: How can a boiler burning only gaseous waste also be 
burning hazardous waste? Uncontained gases are not considered hazardous 
waste under RCRA. Why are boilers that burn only gasses part of the 
liquid fuel boiler subcategory?
    Response: We agree with the commenter that boilers that burn gasses 
are unlikely to burn hazardous wastes. However, gas fuel hazardous 
waste boilers have existed in the past,\177\ and we believe we need to 
define a MACT standard for them. Therefore, we included gas fuel 
boilers in the liquid fuel boiler subcategory for reasons cited in the 
proposed rule. See 69 FR at 21216.
---------------------------------------------------------------------------

    \177\ For example, sources 2014 and 2015 owned by Environmental 
Purification Industries in Toledo, Ohio, were considered hazardous 
waste boilers at the time the Phase II data base was noticed in the 
June 27, 2000, despite the fact that these boilers burned only 
gasses. These boilers have since stopped burning hazardous waste.
---------------------------------------------------------------------------

E. General

1. Alternative to the Particulate Matter Standards
    Comment: Commenters state that some incinerators are currently 
complying with the alternative to the particulate matter standard 
provision pursuant to the interim standards. See Sec.  63.1206(b)(14). 
The eligibility and operating requirements for the alternative to the 
particulate matter standard in the Interim Standards are different than 
the proposed alternative to the particulate matter standard in the 
replacement rule. Specifically, the proposed alternative to the 
particulate matter standard would no longer require sources to 
demonstrate a 90% system removal efficiency or a minimum hazardous 
waste metal feed control level to be eligible for the alternative. 
Commenters request that EPA clarify in the final rule that the proposed 
alternative to the particulate matter standard supersedes the 
requirements in the Interim Standards.
    Response: We are finalizing the alternative to the particulate 
matter standard for incinerators as proposed, with the exception that 
the alternative metal emission limitations have been revised as a 
result of database changes since proposal. See Sec.  1219(e) and part 
three, section II.A. We considered superseding the interim standard 
alternative to the particulate matter standard requirements 
(63.1206(b)(14)) immediately (upon promulgation) by replacing it with 
the revised alternative

[[Page 59478]]

standard provisions finalized in today's rule. Although the eligibility 
requirements for the alternative to the particulate matter standard 
finalized today are less stringent than the interim standard 
requirements, the metal emission limitations that are also required by 
the alternative finalized today are by definition equivalent to or more 
stringent than the metal limitations in the interim standard 
alternative. We therefore cannot completely supersede the interim 
standard provisions immediately (upon promulgation) because sources 
have three years to comply with more stringent standards. We are 
instead revising the interim standard provisions of Sec.  
63.1206(b)(14) to only reflect the revised alternative standard 
eligibility criteria (specifically, we have removed the requirements to 
achieve a given system removal efficiency and hazardous waste metal HAP 
feed control level).\178\ These eligibility criteria revisions become 
effective immediately with respect to the interim standards because 
they are less stringent than the current requirements. Sources should 
modify existing Notifications of Compliance and permit requirements as 
necessary prior to implementing these revised procedures.
---------------------------------------------------------------------------

    \178\ Sources can only use Sec.  63.1206(b)(14) for purposes of 
complying with the interim standards. After the compliance date for 
today's rule, incinerators electing to comply with the alternative 
to the particulate matter standard must comply with the provisions 
found in Sec.  63.1219(e).
---------------------------------------------------------------------------

    Comment: One commenter is opposed to the alternative to the 
particulate matter standard because it ignores the health effects/
benefits that are attributable to particulate matter.
    Response: Particulate matter is not defined as a hazardous air 
pollutant pursuant the NESHAP program. See CAA 112(b)(1). We control 
particulate matter as a surrogate for metal HAP. See part four, section 
IV.A. As a result, a particulate matter standard is not necessary in 
instances where metal HAP emission standards can alternatively and 
effectively control the nonmercury metal HAP that is intended be 
controlled with the surrogate particulate matter standard. The 
alternative to the particulate matter standard in the final rule 
accomplishes this. We acknowledge that particulate matter emission 
reductions result in health benefits. That in itself does not give EPA 
the authority under Sec.  112(d)(2) to directly regulate particulate 
matter, however.
2. Assessing Risk as Part of Consideration of Nonair Environmental 
Impacts
    Comment: Commenter states that EPA has inappropriately failed to 
consider emissions of persistent bioaccumulative pollutants in its 
beyond-the-floor analysis despite EPA's acknowledgment that these HAPs 
have non-air quality health and environmental impacts.
    Response: EPA has taken the consistent position that considerations 
of risk from air emissions have no place when setting MACT standards, 
but rather are to be considered as part of the residual risk 
determination and standard-setting process made under section 112 (f) 
of the statute. EPA thus interprets the requirement in section 112 (d) 
(2) that we consider ``non-air quality health and environmental 
impacts'' as applying to the by-product outputs from utilization of the 
pollution control technology, such as additional amount of waste 
generated, and water discharged.\179\ EPA's interpretation was upheld 
as reasonable in Sierra Club v. EPA, 353 F. 3d 976, 990 (D.C. Cir. 
2004) (Roberts, J.).
---------------------------------------------------------------------------

    \179\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume V: Emission Estimates and Engineering Costs,'' 
September 2005, Section 6, for a discussion of the non-air impact 
that were assessed for this final rule.
---------------------------------------------------------------------------

VII. Health-Based Compliance Alternative for Total Chlorine

A. Authority for Health-Based Compliance Alternatives

    Comment: One commenter states there is no established health 
threshold for either HCl or chlorine.
    Response: Although EPA has not developed a formal evaluation of the 
potential for HCl or chlorine carcinogenicity (e.g., for IRIS), the 
evaluation by the International Agency for Research on Cancer stated 
that there was inadequate evidence for carcinogenicity in humans or 
experimental animals and thus concluded that HCl and chlorine are not 
classifiable as to their carcinogenicity to humans (Group 3 in their 
categorization method). Therefore, for the purposes of this rule, we 
have evaluated HCl and chlorine only with regard to non-cancer effects. 
In the absence of specific scientific evidence to the contrary, it has 
been our policy to classify non-carcinogenic effects as threshold 
effects. RfC development is the default approach for threshold (or 
nonlinear) effects.
    Comment: One commenter states that the proposal is an inappropriate 
forum for bringing forward such a significant change in the way that 
MACT standards are established under Section 112(d) of the Clean Air 
Act. A precedent-setting change of the magnitude that EPA has raised 
should be discussed openly and carefully with all affected parties, 
rather than being buried in several individual proposed standards.
    Response: Including health-based compliance alternatives for 
hazardous waste combustors does not mean that EPA will automatically 
provide such alternatives for other source categories. Rather, as has 
been the case throughout the MACT rule development process, EPA will 
undertake in each individual rule to determine whether it is 
appropriate to exercise its discretion to use its authority under CAA 
section 112(d)(4) in developing applicable emission standards. 
Stakeholders for those affected rules will have ample opportunity to 
comment on the Agency's proposals.
    Comment: One commenter states that the proposed approach is 
contrary to the intent of the CAA which explicitly calls for a general 
reduction in HAP emissions from all major sources nationwide through 
the establishment of MACT standards based on technology, rather than 
risk, as a first step.
    Response: For pollutants for which a health threshold has been 
established, CAA section 112(d)(4) allows the Administrator to consider 
such threshold level, with an ample margin of safety, to establish 
emission standards.
    Comment: One commenter states that the proposed approach would take 
the national air toxics program back to the time-consuming NESHAP 
process that existed prior to the Clean Air Act Amendments of 1990.
    Response: We disagree that allowing a health-based compliance 
alternative in the final rule will alter the MACT program or affect the 
schedule for promulgation of the remaining MACT standards. Today's rule 
is the last MACT rule to be promulgated, and the health-based 
compliance alternative did not delay promulgation of the rule.
    Comment: A commenter is concerned that the proposal would remove 
the benefit of the ``level-playing field'' that would result from the 
proper implementation of technology-based MACT standards.
    Response: Providing health-based compliance alternatives in the 
final rule for sources that can meet them will assure the application 
of a uniform set of requirements across the nation. The final rule and 
its criteria for demonstrating eligibility for the health-based 
compliance alternatives apply uniformly to all hazardous waste 
combustors except hydrochloric acid

[[Page 59479]]

production furnaces. The final rule establishes two baseline levels of 
emission reduction for total chlorine, one based on a traditional MACT 
analysis and the other based on EPA's evaluation of the health threat 
posed by emissions of HCl and chlorine. All hazardous waste combustor 
facilities must meet one of these baseline levels, and all facilities 
have the same opportunity to demonstrate that they can meet the 
alternative health-based emission standards. We also note that 
additional uniformity is provided by limiting the health-based 
compliance alternatives for incinerators, cement kilns, and lightweight 
aggregate kilns to the emission levels allowed by the Interim 
Standards.
    Comment: Several commenters state that site-specific emission 
limits are inappropriate under section 112(d)(4) because they are not 
emission standards. One commenter asserts that the Agency's position 
that the limits are based on uniform procedures is flawed because the 
process allows ``any scientifically-accepted, peer-reviewed risk 
assessment methodology for your site-specific compliance 
demonstration.'' This is not a ``uniform'' procedure, according to the 
commenter. There are a host of variables that influence the results of 
an accepted methodology. The commenter reasons that, without some 
standardization of those variables, there is no uniform or standard 
analysis. Each permitting authority could establish its view of 
appropriate variables; there would be no national consistency.
    Several other commenters assert that EPA has the authority to 
establish an exposure-based emission limit for total chlorine. One 
commenter notes that one issue that often arises when considering risk-
based standards is whether EPA has authority under section 112 to 
establish an exposure-based emission limit. The commenter states that 
the concern seems to be that some stakeholders construe the Act's 
statutory provisions as requiring uniform emission limitations at all 
facilities, rather than emissions that are measured at places away from 
the source and that vary from facility to facility. The commenter does 
not see any legal impediment to establishing exposure-based limits.
    The commenter notes that, first, under section 112, EPA has 
authority to establish ``emission standards.'' Emission standards are 
defined to be a requirement established by the State or the 
Administrator which limits the quantity, rate or concentration of 
emissions of air pollutants on a continuous basis * * * to assure 
continuous emission reduction, and any design, equipment, work practice 
or operational standard promulgated under this chapter. EPA's alternate 
risk-based emission standard will limit the quantity, rate or 
concentration of the emissions. The commenter states that there is no 
requirement in the definition that specifies where the emission 
standard is to be measured, nor is there such a requirement anywhere in 
the statute.
    Second, the commenter notes that EPA's proposed exposure-based 
limit will result in facilities establishing operating parameter 
limitations, or OPLs. These OPLs qualify as emission limitations 
because they are ``operational standards'' being promulgated under 
section 112, according to the commenter. They will be measured at the 
facility, not at the point of exposure. Finally, the commenter reasons 
that the limitations EPA is establishing are uniform. They uniformly 
protect the individual most exposed to emission levels no higher than a 
hazard index of 1.0. Consequently, the commenter believes that there is 
nothing in the statute that prevents the Agency from promulgating 
exposure-based emission standards.
    Response: We agree with the commenters who believe the Agency has 
the authority to establish health-based compliance alternatives under a 
national exposure standard. In particular, we agree with the commenter 
that the health-based compliance alternatives are national standards 
since they provide a uniform and national measure of risk control, and 
also that the health-based compliance alternatives are ``emission 
standards'' because they limit the quantity, rate or concentration of 
total chlorine emissions.
    Section 112(d)(4) authorizes EPA to bypass the mandate in section 
112(d)(3) in appropriate circumstances. Those circumstances are present 
for hazardous waste combustors other than hydrochloric acid production 
furnaces. Section 112(d)(4) provides EPA with authority, at its 
discretion, to develop health-based compliance alternatives for HAP 
``for which a health threshold has been established,'' provided that 
the standard reflects the health threshold ``with an ample margin of 
safety.''
    Both the plain language of section 112(d)(4) and the legislative 
history indicate that EPA has the discretion under section 112(d)(4) to 
develop health-based compliance alternatives for some source categories 
emitting threshold pollutants, and that those standards may be less 
stringent than the corresponding MACT standard (including floor 
standards) would be.\180\ EPA's use of such standards is not limited to 
situations where every source in the category or subcategory can comply 
with them. As with technology-based standards, a particular source's 
ability to comply with a health-based standard will depend on its 
individual circumstances, as will what it must do to achieve 
compliance.
---------------------------------------------------------------------------

    \180\ See also Legislative History at 876 (section 112(d)(4) 
standard may be less stringent than MACT).
---------------------------------------------------------------------------

    In developing health-based compliance alternatives under section 
112(d)(4), EPA seeks to ensure that the concentration of the particular 
HAP to which an individual exposed at the upper end of the exposure 
distribution is exposed does not exceed the health threshold. The upper 
end of the exposure distribution is calculated using the ``high end 
exposure estimate,'' defined as ``a plausible estimate of individual 
exposure for those persons at the upper end of the exposure 
distribution, conceptually above the 90th percentile, but not higher 
than the individual in the population who has the highest exposure'' 
(EPA Exposure Assessment Guidelines, 57 FR 22888, May 29, 1992). 
Assuring protection to persons at the upper end of the exposure 
distribution is consistent with the ``ample margin of safety'' 
requirement in section 112(d)(4).
    We agree with the view of several commenters that section 112(d)(4) 
is appropriate for establishing health-based compliance alternatives 
for total chlorine for hazardous waste combustors other than 
hydrochloric acid production furnaces. Therefore, we have established 
such compliance alternatives for affected sources in those categories. 
Affected sources which believe that they can demonstrate compliance 
with the health-based compliance alternatives may choose to comply with 
those compliance alternatives in lieu of the otherwise applicable MACT-
based standard.
    Comment: One commenter states that the risk assessments would not 
provide an ample margin of safety because background exposures are not 
taken into account. There is no accounting for other chlorine compounds 
from other sources at the facility, or from other neighboring 
facilities. The commenter believes that there is no evidence in the 
section 112(f) residual risk assessments produced thus far that 
emissions from collocated sources will actually be pursued by EPA. The 
commenter also notes that the Urban Air Toxics program cannot be relied 
upon to address ambient background. This program,

[[Page 59480]]

required under section 112(k), was to be completed by 1999. However, 
the strategy has not been finalized and the small amount of activity in 
this area is focused on voluntary emission reductions rather than 
federal requirements. Finally, the commenter notes that control of 
criteria pollutants via State Implementation Plans to achieve 
compliance with the NAAQS is problematic. For particulate matter (PM) 
and ozone, new NAAQS were set in 1997 and seven years later the 
nonattainment designations are still being determined. The designation 
process will be followed by a 3 year period to prepare State 
Implementation Plans and several more years to carry out those plans. 
In the meantime, there will be high levels of PM and ozone in the air 
near many hazardous waste combustors in New Jersey which will 
exacerbate exposures to chlorine and hydrogen chloride.
    Response: Total chlorine missions from collocated hazardous waste 
combustors must be considered in establishing health-based compliance 
alternatives under Sec.  63.1215. Ambient levels of HCl or chlorine 
attributable to other on-site sources, as well as off-site sources, are 
not considered, however. As we indicated in the Residual Risk Report to 
Congress and in the recent residual risk rule for Coke Ovens, the 
Agency intends to consider facility-wide HAP emissions as part of the 
ample margin of safety determination for CAA section 112(f) residual 
risk actions. 70 FR at 19996-998 (April 15, 2005); see also, 54 FR at 
38059 (Sept. 14, 1989) (benzene NESHAP).
    Comment: Several commenters state that acute exposure guideline 
levels (AEGLs) are once-in-a-lifetime exposure levels. They assert 
that, because short term exposures at a Hazard Index greater than 1.0 
may occur more than once in a lifetime, using AEGLs for the purpose of 
setting risk-based short-term limits for HCl and chlorine does not 
provide an ``ample margin of safety.''
    Response: To assess acute exposure, we proposed to use acute 
exposure guideline levels for 1-hour exposures (AEGL-1) as health 
thresholds. We have investigated commenters' concerns, however, and 
conclude that AEGLs are not likely to be protective of human health 
because individuals may be subject to multiple acute exposures at a 
Hazard Index greater than 1.0 from hazardous waste combustors. 
Consequently, we use acute Reference Exposure Levels (aRELs) rather 
than acute exposure guideline levels (AEGLs) as acute exposure 
thresholds for the final rule. See also Part Two, Section IX.D above. 
Acute RELs are health thresholds below which there would be no adverse 
health effects while AEGL-1 values are health thresholds below which 
there may be mild adverse effects.
    Acute exposures are relevant (in addition to chronic exposures) and 
the acute exposure hazard index of 1.0 could be exceeded multiple times 
over an individual's lifetime. Although we concluded at proposal that 
the chronic exposure Hazard Index would always be higher than the acute 
exposure Hazard Index, and thus would be the basis for the total 
chlorine emission rate limit, this conclusion relates to acute versus 
chronic exposure to a constant, maximum average emission rate of total 
chlorine from a hazardous waste combustor. See 69 FR at 21300. We 
explained that acute exposure must nonetheless be considered when 
establishing operating requirements to ensure that short-term emissions 
do not result in an acute exposure Hazard Index of greater than 1.0. 
This is because total chlorine and chloride feedrates to a hazardous 
waste combustor (e.g., commercial incinerator) can vary substantially 
over time. Although a source may remain in compliance with a feedrate 
limit with a long-term averaging period (e.g., 12-hour, monthly, or 
annual) based on the chronic Hazard Index, the source could feed 
chlorine during short periods of time that substantially exceed the 
long-term feedrate limit. This could result potentially in emissions 
that exceed the one-hour (i.e., acute exposure) Hazard Index. 
Consequently, we discussed at proposal the need to establish both 
short-term and long-term total chlorine and chloride feedrate limits to 
ensure that neither the chronic exposure nor the acute exposure Hazard 
Index exceeds 1.0.\181\
---------------------------------------------------------------------------

    \181\ Note that we conclude for the final rule that most sources 
are not likely to exceed the acute Hazard Index because they will 
establish a 12-hour rolling average chlorine feedrate limit and 
their chlorine feedrates are not likely to vary substantially over 
that averaging period. Thus, we believe that most sources will not 
be required to establish an hourly rolling average chlorine feedrate 
limit. The owner/operator must determine whether the hourly rolling 
average chloride feedrate limit can be waived under Sec.  
63.1215(d).
---------------------------------------------------------------------------

    We conclude that 1-hour Reference Exposure Levels (aRELs) are a 
more appropriate health threshold metric than AEGL-1 values for 
hazardous waste combustors given that the acute Hazard Index limit of 
1.0 may be exceeded multiple times over an individual's lifetime, 
albeit resulting from uncontrollable factors. The California Office of 
Health Hazard Assessment has developed acute health threshold levels 
that are intended to be protective for greater than once in a lifetime 
exposures. The acute exposure levels are called acute Reference 
Exposure Levels and are available at  http://www.oehha.ca.gov/air/acute_rels/acuterel.html.
    The 1-hour REL values for hydrogen chloride and chlorine are 2.1 
mg/m<SUP>3</SUP> and 0.21 mg/m<SUP>3</SUP>, respectively. The AEGL-1 
values for hydrogen chloride and chlorine are 2.7 mg/m<SUP>3</SUP> and 
1.4 mg/m<SUP>3</SUP>, respectively. Although there is little difference 
between the 1-hour REL and AEGL-1 values for hydrogen chloride, the 1-
hour REL for chlorine is substantially lower than the AEGL-1 value.
    In summary, we believe that aRELs are a more appropriate health 
threshold metric than AEGL-1 values for establishing health-based 
compliance alternatives for hazardous waste combustors because aRELs 
are ``no adverse effect'' threshold levels that are intended to be 
protective for multiple exposures.
    Comment: One commenter states that the health-based compliance 
alternative is unlawful because the proposal does not address 
ecological risks that may result from uncontrolled HAP emissions, 
including risks posed to those areas where few people currently live, 
but sensitive habitats exist.
    Response: An ecological assessment is normally required under CAA 
section 112(d)(4) to assess the presence or absence of ``adverse 
environmental effects'' as that term is defined in CAA section 
112(a)(7). To identify potential multimedia and/or environmental 
concerns, EPA has identified HAP with significant potential to persist 
in the environment and to bioaccumulate. This list does not include 
hydrogen chloride or chlorine.
    We also note that health-based total chlorine emission limits for 
incinerators, cement kilns, and lightweight aggregate kilns cannot be 
higher than the current Interim Standards. See Sec.  63.1215(b)(7). 
Thus, the ecological risk from total chlorine emissions from these 
sources will not be increased under the health-based limits.
    In addition, we note that only 2 of 12 solid fuel boilers have 
total chlorine emissions higher than 180 ppmv, and only 1 liquid fuel 
boiler has emissions higher than 170 ppmv. Thus, boilers generally have 
low total chlorine emissions which would minimize ecological risk.
    Consequently, we do not believe that emissions of hydrogen chloride 
or chlorine from hazardous waste boilers will pose a significant risk 
to the environment, and facilities attempting to comply with the 
health-based

[[Page 59481]]

alternatives for these HAP are not required to perform an ecological 
assessment.

B. Implementation of the Health-Based Standards

    Comment: Several commenters are concerned that the health-based 
compliance alternative will place an intensive resource demand on state 
and local agencies to review and approve facilities' eligibility 
demonstrations, and State and local agencies may not have adequate 
expertise to review and approve the demonstrations. One commenter 
states that permitting authorities do not have the expertise to review 
eligibility demonstrations that are based on procedures other than 
those included in EPA's Reference Library, as would be allowed. The 
commenter also states that, if the health-based compliance alternative 
is promulgated, EPA should establish one standard method for the 
analyses so there is consistency nationwide. If EPA offers more than 
one method, EPA should do all of the risk assessment reviews, instead 
of passing the responsibility, without clear direction, to the 
permitting authorities, according to the commenter.
    Response: The health-based compliance alternatives for total 
chlorine that EPA has adopted in the final rule should not impose 
significant resource burdens on states. The required compliance 
demonstration methodology is structured in such a way as to avoid the 
need for states to have significant expertise in risk assessment 
methodology. We have considered the commenters' concerns in developing 
the criteria defining eligibility for these compliance alternatives, 
and the approach that is included in the final rule provides clear, 
flexible requirements and enforceable compliance parameters. The final 
rule provides two ways that a facility may demonstrate eligibility for 
complying with the health-based compliance alternatives. First, look-up 
tables allow facilities to determine, using a limited number of site-
specific input parameters, whether emissions from their sources might 
cause the Hazard Index limit to be exceeded. Second, if a facility 
cannot demonstrate eligibility using a look-up table, a modeling 
approach can be followed. The final rule presents the criteria for 
performing this modeling.
    Only a portion of hazardous waste combustors will submit 
eligibility demonstrations for the health-based compliance 
alternatives. Of these sources, several should be able to demonstrate 
eligibility based on simple analyses--using the look-up tables. 
However, some facilities will require more detailed modeling. The 
criteria for demonstrating eligibility for the compliance alternatives 
are clearly defined in the final rule. Moreover, under authority of 
RCRA section 3005(c)(3), multi-pathway risk assessments will typically 
have already been completed for many hazardous waste combustors to 
document that emissions of toxic compounds, including total chlorine, 
do not pose a hazard to human health and the environment. Thus, state 
permitting officials have already reviewed and approved detailed 
modeling studies for many hazardous waste combustors. The results of 
these studies could be applied to the eligibility demonstration 
required by this final rule.
    Because these requirements are clearly defined, and because any 
standards or requirements created under CAA section 112 are considered 
applicable requirements under 40 CFR part 70, the compliance 
alternatives would be incorporated into title V programs, and states 
would not have to overhaul existing permitting programs.
    Finally, with respect to the burden associated with ongoing 
assurance that facilities that opt to do so continue to comply with the 
health-based compliance alternatives, the burden to states will be 
minimal. In accordance with the provisions of title V of the CAA and 
part 70 of 40 CFR (collectively ``title V''), the owner or operator of 
any affected source opting to comply with the health-based compliance 
alternatives is required to certify compliance with those standards 
every five years on the anniversary of the comprehensive performance 
test. In addition, if the facility has reason to know of changes over 
which the facility does not have control, and these changes could 
decrease the allowable HCl-equivalent emission rate limit, the facility 
must submit a revised eligibility demonstration. Further, before 
changing key parameters that may impact an affected source's ability to 
continue to meet the health-based emission standards, the source is 
required to evaluate its ability to continue to comply with the health-
based compliance alternatives and submit documentation to the 
permitting authority supporting continued eligibility for the 
compliance alternative. Thus, compliance requirements are largely self-
implementing and the burden on states will be minimal.
    Comment: One commenter suggests that the look-up tables would have 
more utility if EPA developed tables for each source category to ensure 
the HCl-equivalent emission rate limits reflected stack parameters 
representative of each source category. Similarly, another commenter 
notes that a look-up table designed to be applicable to all hazardous 
waste combustors is very conservative and will have limited utility. 
This commenter does not suggest that EPA develop look-up tables for 
each class of hazardous waste combustors, however. Rather, the 
commenter suggests that since look-up tables have already been 
developed for industrial boilers that do not burn hazardous waste \182\ 
hazardous waste combustors should be allowed to use those look-up 
tables instead of the look-up tables proposed for hazardous waste 
combustors.
---------------------------------------------------------------------------

    \182\ See Table 2 of Appendix A to Subpart DDDDD, Part 63.
---------------------------------------------------------------------------

    Response: We noted at proposal that the emission rates provided in 
the look-up table for hazardous waste combustors are more stringent 
than those promulgated for solid fuel industrial boilers that do not 
burn hazardous waste. This is because the key parameters used by the 
SCREEN3 atmospheric dispersion model (i.e., stack diameter, stack exit 
gas velocity, and stack exit gas temperature) to predict the normalized 
air concentrations that EPA used to establish HCl-equivalent emission 
rates for solid fuel industrial boilers that do not burn hazardous 
waste are substantially different for hazardous waste combustors. Thus, 
the maximum HCl-equivalent emission rates for hazardous waste 
combustors would generally be lower than those EPA established for 
solid fuel industrial boilers that do not burn hazardous waste.
    Nonetheless, we agree with the commenter's concerns that the look-
up tables would have more utility if they better reflected the range of 
stack properties representative of hazardous waste combustors. 
Accordingly, we examined the stack parameters for all hazardous waste-
burning sources in our data base (except for hydrochloric acid 
production furnaces that are not eligible for the health-based emission 
standards). After analyzing the relationships among the various stack 
parameters (i.e., stack height, stack diameter, stack gas exhaust 
volume, and exit temperature), we concluded that the look-up table 
should be modified to treat both stack diameter and stack height as 
independent variables rather than relying on stack height alone.
    We developed separate tables for short-term (i.e., 1-hour) HCl-
equivalent

[[Page 59482]]

emissions limits to protect against acute health effects and long-term 
(i.e., annual) emission limits to protect against chronic effects from 
exposures to chlorine and hydrogen chloride. As discussed above, we 
used the acute Reference Exposure Level (aREL) developed by Cal-EPA as 
the benchmark for acute health effects. We used EPA's Reference 
Concentrations (RfC) as the benchmark for chronic health effects from 
exposures occurring over a lifetime.
    Emission limits in the look-up table are expressed in terms of HCl-
toxicity equivalent emission rates (lbs/hr). To convert your total 
chlorine emission rate (lb/hr) to an HCl-equivalent emission rate, you 
must adjust your chlorine emission rate by a multiplicative factor 
representing the ratio of the HCl health risk benchmark to the chlorine 
health risk benchmark. For 1-hour average HCl-equivalent emission 
rates, the ratio is the ratio of the aREL for HCl (2100 micrograms per 
cubic meter) to the aREL for chlorine (210 micrograms per cubic meter), 
or a factor of 10.\183\ For annual average emissions, the ratio is the 
ratio of the RfC for HCl (20 micrograms per cubic meter) to the RfC of 
chlorine (0.2 micrograms per cubic meter), or a factor of 100. See 
Sec.  63.1215(b).
---------------------------------------------------------------------------

    \183\ We note that this factor of 10 ratio of the aRELs of HCl 
to chlorine is based on current aREL values and is subject to 
change. You must use current aREL (and RfC) values when you conduct 
your eligibility demonstration. See Sec.  63.1215(b)(4 and 5).
---------------------------------------------------------------------------

    We used the SCREEN3 air dispersion model to develop the emission 
limits in the look-up tables. SCREEN3 is a screening model that 
estimates air concentrations under a wide variety of meteorological 
conditions in order to identify the meteorological conditions under 
which the highest ambient air concentrations are likely to occur and 
what the magnitude of the ambient air concentrations are likely to be. 
The SCREEN3 model implements the procedures in EPA's ``Screening 
Procedures for Estimating the Air Quality Impact of Stationary Sources, 
Revised'' (EPA-454/R-92-019, U.S. Environmental Protection Agency, 
Office of Air Quality Planning and Standards, Research Triangle Park, 
NC, October 1992). Included are options for estimating ambient air 
concentrations in simple elevated terrain and complex terrain. Simple 
elevated terrain refers to terrain elevations below stack top. We did 
not use the complex terrain option in the development of the look-up 
tables because of the site-specific nature of plume impacts in areas of 
complex terrain. Therefore, the look-up tables cannot be used in areas 
of complex terrain (which we define generally as terrain that rises 
above stack top). Sources located in complex terrain (i.e., as a 
practical matter, sources other than those that are located in flat or 
simple elevated terrain as discussed below and thus cannot use the 
look-up tables) must use site-specific modeling procedures to establish 
HCl-equivalent emission rates.
    We looked at two generic terrain scenarios for purposes of the 
look-up table. In one we assumed the terrain rises at a rate of 5 
meters for every 100 meter run (i.e., a slope of 5 percent) and that 
terrain is ``chopped off'' above stack top (following the convention 
for such analyses in simple elevated terrain). In the other we assumed 
flat terrain. As can be seen from the tables in Sec.  63.1215, the 
emission limits with flat terrain are significantly higher than those 
with simple elevated terrain. To reasonably ensure that the emission 
limits are not substantially over-stated (e.g., by a factor of 2), the 
simple elevated terrain table must be used whenever terrain rises to an 
elevation of one half (\1/2\) the stack height within a distance of 50 
stack heights.
    For both the simple elevated terrain and flat terrain scenarios, we 
performed model runs for urban and rural dispersion conditions, with 
and without building downwash. We selected the highest (ambient air 
concentration) values at each distance from among the four runs for 
each of the terrain scenarios.
    As can be seen from the tables in Sec.  63.1215, the HCl-equivalent 
emission rate limits range from 0.13 pounds per hour on an annual 
average (for a 0.3 meter diameter stack that is 5 meters tall that lies 
within 30 meters of the property boundary) to 340 pounds per hour (for 
a 4.0 meter diameter stack that is 100 meters tall that lies 5000 
meters from the property boundary) when located in simple elevated 
terrain. In flat terrain, the range is from 0.37 to 1100 pounds per 
hour on an annual average. This contrasts with the look-up table at 
proposal, where the comparable range was from 0.0612 pounds per hour 
(for a 5 meter stack height at a distance of 30 meters) to a maximum of 
18 pounds per hour (for stack heights of 50 meters or greater, at 
distances of 500 meters or greater).
    If you have more than one hazardous waste combustor on site, the 
sum of the ratios for all combustors of the HCl-equivalent emission 
rate to the HCl-equivalent emission rate limit cannot exceed 1.0. See 
Sec.  63.1215 (c)(3)(v). This will ensure that the Hazard Index of 1.0 
is not exceeded considering emissions from all on-site combustors.
    Comment: Several commenters state that facilities should be allowed 
to establish an averaging period for the total chlorine and chloride 
feedrate limit that is shorter than an annual rolling average. 
Commenters are referring to the feedrate limit to ensure compliance 
with the annual average HCl-equivalent emission rate limit. Commenters 
are concerned with the data handling issues that could arise from 
calculating, recording, and reporting an annual rolling average 
feedrate level that is updated hourly, and note that a shorter 
averaging period would make the limit more stringent.
    Response: We agree with commenters, and conclude, moreover, that a 
12-hour averaging period rather than an annual averaging period will be 
imposed on the vast majority of sources as a practical matter. This is 
because sources must establish a limit on the feedrate of total 
chlorine and chloride to ensure compliance with the semivolatile metals 
emission standards. See Sec.  63.1209(n). The feedrate limit for total 
chlorine and chloride is established under Sec.  63.1209(n) as the 
average of the hourly rolling averages for each test run, and the 
averaging period is 12 hours. Thus, the averaging period for the 
feedrate limit for semivolatile metals--12-hour rolling average updated 
hourly--trumps the annual rolling average averaging period that would 
otherwise apply here.\184\
---------------------------------------------------------------------------

    \184\ To also ensure compliance with the annual average HCl-
equivalent emission rate limit, however, the numerical value of the 
feedrate limit established during the semivolatile metals 
performance test cannot exceed the value calculated as the annual 
average HCl-equivalent emission rate limit divided by [1 - system 
removal efficiency], where you demonstrate the total chlorine system 
removal efficiency during the comprehensive performance test.
---------------------------------------------------------------------------

    Sources may also demonstrate compliance with the semivolatile 
metals standard by assuming all semivolatile metals in feedstreams are 
emitted. See Sec.  63.1207(m)(2). Sources that do not have emission 
control equipment, such as most liquid fuel boilers, are particularly 
likely to use this approach. Under this approach, there is no concern 
regarding increased volatility of metals as chlorine feedrates 
increase, and such sources are not subject to a feedrate limit for 
chlorine for compliance assurance with the semivolatile metal standard. 
These sources may establish an averaging period for the feedrate of 
total chlorine and chloride for compliance with the health-based 
compliance alternative for total chlorine of not to exceed one 
year.\185\
---------------------------------------------------------------------------

    \185\ We note that we have also applied this ``not-to-exceed'' 
approach to establishing the duration of averaging periods for the 
limits on all operating parameters established under Sec.  63.1209. 
See new Sec.  63.1209(r) and USEPA, ``Final Technical Support 
Document for HWC MACT Standards, Volume IV: Compliance with HWC MACT 
Standards, September 2005, Section 2.4.6.

---------------------------------------------------------------------------

[[Page 59483]]

    Comment: Several commenters offered suggestions on whether a short-
term feedrate limit was needed for total chlorine and chloride (i.e., 
chlorine) as EPA suggested, and if EPA continues to consider it 
necessary, how the limit should be established.
    One commenter states that it is not necessary to set short-term 
limits for chlorine feedrates. If EPA concludes that short-term limits 
are necessary, however, the commenter recommended these options: (1) 
Cap the feedrate at a level that is extrapolated up to the feedrate 
associated with Interim Standard for incinerators; (2) if the facility 
uses the site-specific option to set emission limits, the dispersion 
models can easily be used to set a 1-hour (or longer) limit; and (3) if 
the facility uses the look up table (which at proposal provided only 
annual average HCl-equivalent emission rate limits), a short-term limit 
can be set based on a multiplier of the annual limit'10 times the 
annual limit as recommended by documents in EPA's Air Toxics Risk 
Assessment Reference Library.
    Another commenter states that, if EPA were to promulgate a short-
term feedrate limit, the EPA-endorsed factor of 0.08 employed to 
translate maximum hourly concentrations to annual concentrations could 
be used to identify the maximum hourly feedrate limit.
    Finally, another commenter states that extrapolation of the 
chlorine feedrate (from the level during the comprehensive performance 
test when the source documents compliance with the annual average HCl-
equivalent emission rate limit) should be allowed to 100% of the 1-hour 
average HCl-equivalent emission rate limit because numerous safety 
factors have already been included in the health risk threshold values, 
look-up tables, and modeling demonstration.
    Response: At proposal, we explained that sources would establish an 
annual average feedrate limit on chlorine as the feedrate level during 
the comprehensive performance test demonstrating compliance with the 
annual average HCl-equivalent emission rate limit. \186\ Only long-term 
exposures--maximum annual average exposures--need be considered when 
confirming that the chlorine feedrate during the comprehensive 
performance test (i.e., average of the hourly rolling averages for each 
run) is acceptable because the annual exposure Hazard Index limit 
(i.e., not to exceed 1.0) would always be exceeded before the 1-hour 
Hazard Index limit (i.e., not to exceed 1.0). Thus, the feedrate limit 
associated with annual exposures would always be more stringent than 
the feedrate limit associated with 1-hour exposures. See 69 FR at 
21299.
---------------------------------------------------------------------------

    \186\ We discussed at proposal that the feedrate limit to ensure 
compliance with the long-term Hazard Index limit of not to exceed 
1.0 would be the average of the hourly rolling averages for each 
test run, with compliance based on an annual average. Note that, 
under the final rule however, the long-term chlorine feedrate limit 
is established as the annual average HCl-equivalent emission rate 
limit divided by [1 - system removal efficiency]. See Sec.  
63.1215(g)(2).
---------------------------------------------------------------------------

    We further explained at proposal, however, the need to establish a 
short-term feedrate limit for chlorine to ensure that the 1-hour HCl-
equivalent emission rate did not exceed the 1-hour average HCl-
equivalent emission rate limit due to variability in the chlorine 
feedrate during the annual averaging period for the feedrate limit. We 
requested comment on approaches to establish this 1-hour chlorine 
feedrate limit, including extrapolating feedrates to 100% of the 1-hour 
average HCl-equivalent emission rate limit. See 69 FR at 21304.
    In the final rule we have corrected and refined these procedures. 
The final rule requires you to establish a long-term chlorine feedrate 
limit to maintain compliance with the annual average HCl-equivalent 
emission rate limit as either: (1) The chlorine feedrate during the 
comprehensive performance test if you demonstrate compliance with the 
semivolatile metals emission standard during the test (see Sec.  
63.1209(o)); or (2) if you comply with the semivolatile metals emission 
standard under Sec.  63.1207(m)(2) by assuming all metals in the feed 
to the combustor are emitted, the annual average HCl-equivalent 
emission rate limit divided by [1 - system removal efficiency] where 
you demonstrate the system removal efficiency during the comprehensive 
performance test. See discussion in Part Two, Section IX.H, of this 
preamble. If you establish the chlorine feedrate limit based on the 
feedrate during the performance test to demonstrate compliance with the 
semivolatile metals emission standard, the averaging period for the 
feedrate limit is a 12-hour rolling average. If you establish the 
chlorine feedrate limit based on the system removal efficiency during 
the performance test, the averaging period is up to an annual rolling 
average.
    The final rule also requires you to establish an hourly rolling 
average chlorine feedrate limit if you determine under Sec.  
63.1215(d)(3) that the 1-hour average HCl-equivalent emission rate 
limit may be exceeded. That feedrate limit is established as the 1-hour 
HCl-equivalent emission rate limit divided by [1 - system removal 
efficiency].
    Under Sec.  63.1215(d)(3), you must establish an hourly rolling 
average chlorine feedrate limit unless you determine considering 
specified criteria that your chlorine feedrates will not increase over 
the averaging period for the long-term chlorine feedrate limit (i.e., 
12-hour rolling average or (up to) annual rolling average) to a level 
that may result in an exceedance of the 1-hour average HCl-equivalent 
emission rate limit. The criteria that you must consider are: (1) The 
ratio of the 1-hour average HCl-equivalent emission rate based on the 
total chlorine emission rate you select for each combustor to the 1-
hour average HCl-equivalent emission rate limit for the combustor; and 
(2) the potential for the source to vary chlorine feedrates 
substantially over the averaging period for the long-term chlorine 
feedrate limit.
    For example, if a source's primary chlorine-bearing feedstreams 
have a relatively constant chlorine concentration over the averaging 
period for the chlorine feedrate limit to ensure compliance with the 
annual average HCl-equivalent emission rate limit (e.g., generally 12-
hours), as may be the case for commercial sources feeding from large 
burn tanks or on-site sources where chlorine levels in wastes are 
fairly constant, you may conclude that there is little probability that 
1-hour feedrates would vary substantially over the averaging period. 
Thus, a 1-hour rolling average chlorine feedrate limit may not be 
warranted. Even if chlorine feedrates could vary substantially over the 
long-term feedrate averaging period, however, an hourly rolling average 
feedrate limit still may not be warranted if the source's 1-hour 
average HCl-equivalent emission rate is well below the 1-hour HCl-
equivalent emission rate limit. See Part Two, Section IX.H, of this 
preamble for a discussion of the relationship between emission rates, 
emission rate limits, and feedrate limits.
    We disagree with the commenter who states that short-term chlorine 
feedrate limits are not necessary. The 1-hour average HCl-equivalent 
emission rate limit could potentially be exceeded for sources with 
highly variable chlorine feedrates and where the 1-hour HCl-equivalent 
emission rate is relatively high compared to the 1-hour HCl-equivalent 
emission rate limit. The 1-hour average HCl-equivalent emission rate 
limit could be exceeded even though the source remains in compliance 
with the annual average HCl-equivalent emission rate limit (and,

[[Page 59484]]

moreover, the 12-hour rolling average or (up to) annual rolling average 
chlorine feedrate limit).
    We agree with commenters that suggest that the hourly rolling 
average chlorine feedrate limit should be extrapolated from performance 
test feedrates up to 100% of the 1-hour average HCl-equivalent emission 
rate limit. The final rule requires you to establish the hourly rolling 
average feedrate limit (if a limit is required under Sec.  
63.1215(d)(3)) as the 1-hour HCl-equivalent emission rate limit divided 
by [1 - system removal efficiency]. Establishing the hourly rolling 
average feedrate in this manner ensures that the 1-hour HCl-equivalent 
emission rate limit is not exceeded, and thus that the aREL-based 
Hazard Index of 1.0 is not exceeded.
    We also agree in principle with commenters that suggest that the 
hourly rolling average feedrate limit be based on the 1-hour average 
HCl-equivalent emission rate limit which is based on emissions 
modeling. These commenters suggested that we use a multiplier of 10 or 
12.5 (i.e., 1/0.08) to project 1-hour average HCl-equivalent emission 
rate limits from the annual average HCl-equivalent emission rate 
limits. Rather than use these approaches to project 1-hour average 
emissions from annual average emissions, however, we use emissions 
modeling to develop look-up tables for both 1-hour average HCl-
equivalent emission rate limits and annual average HCl-equivalent 
emission rate limits. For sources that use site-specific risk 
assessment to demonstrate eligibility, they will use the same models to 
estimate 1-hour average maximum ambient concentrations. Thus, the final 
rule uses modeling to establish directly 1-hour average HCl-equivalent 
emission rate limits rather than approximating those limits from annual 
average HCl-equivalent emission rate limits as commenters suggest. In 
summary, the final rule requires you to establish the 1-hour average 
HCl-equivalent emission rate limit by either using Tables 3 or 4 in 
Sec.  63.1215 to look-up the limit, or conducting a site-specific risk 
analysis. Under the site-specific risk analysis option, the 1-hour 
average HCl-equivalent emission rate limit would be the highest 
emission rate that the risk assessment estimates would result in an 
aREL-based Hazard Index not exceeding 1.0 at any off-site receptor 
location.
    We do not agree that the short-term feedrate limit should be capped 
at the level corresponding to the Interim Standards for incinerators, 
cement kilns, and lightweight aggregate kilns. The final rule caps the 
total chlorine emission rate and the annual average HCl-equivalent 
emission rate limit at the level equivalent to the Interim Standard for 
total chlorine. Thus, the long-term chlorine feedrate limit (12-hour 
rolling average or (up to) an annual rolling average) is capped at the 
level corresponding to the Interim Standards for incinerators, cement 
kilns, and lightweight aggregate kilns. The hourly rolling average 
feedrate limit to maintain compliance with the 1-hour average HCl-
equivalent emission rate limit, however, can exceed the numerical value 
of the long-term chlorine feedrate limit because the 1-hour average 
HCl-equivalent emission rate limit is substantially higher than the 
annual average HCl-equivalent emission rate limit. Thus, capping at the 
interim standard level is inappropriate unless the interim standard 
were somehow re-expressed as a 1-hour limit.
    Comment: Many commenters state that requiring prior approval of the 
eligibility demonstration would be unworkable. Commenters are concerned 
that the permitting authority may not approve the demonstration prior 
to the compliance date even though the source has submitted complete 
and accurate information and has responded to any requests for 
additional information in good faith. Commenters are also concerned 
that the permitting authority may disapprove the demonstration too late 
for the source to take other measures to comply with the total chlorine 
MACT standard. Once commenter recommends the following alternative 
approach: (1) If the regulatory agency does not act on a risk 
demonstration within the 6-month period, it is conditionally deemed 
approved; and (2) if a risk demonstration is disapproved, the source 
would have to comply with the MACT emission standards no later than 
three years after notice of disapproval and, in the interim, sources 
would comply with current emission limits for total chlorine.
    Another commenter suggests that, if the permitting authority has 
neither approved nor disapproved the eligibility demonstration by the 
compliance date, the source may begin complying on the compliance date 
with the alternative health-based limits specified in the eligibility 
demonstration.
    Finally, another commenter states that facilities should be granted 
a three-year extension of the compliance date if the Agency denies a 
good-faith eligibility demonstration. The commenter is concerned that 
sources will not have time to install additional controls or take other 
measures after a denial is issued but prior to the compliance date.
    Response: We agree with commenters that requiring prior approval of 
the eligibility demonstration may be unworkable for the reasons 
commenters suggest. We also agree with commenters that sources who make 
a good-faith eligibility demonstration but whose demonstration is 
denied by the permitting authority may need additional time to install 
controls or take other measures to comply with the MACT emission 
standards.
    Accordingly, the final rule does not require prior approval of the 
eligibility demonstration for existing sources. If your permitting 
authority has not approved your eligibility demonstration by the 
compliance date, and has not issued a notice of intent to disapprove 
your demonstration, you may nonetheless begin complying, on the 
compliance date, with the HCl-equivalent emission rate limits and 
associated chlorine feedrate limits you present in your eligibility 
demonstration.
    In addition, the final rule states that the permitting authority 
should notify you of approval or intent to disapprove your eligibility 
demonstration within 6 months after receipt of the original 
demonstration, and within 3 months after receipt of any supplemental 
information that you submit. A notice of intent to disapprove your 
eligibility demonstration, whether before or after the compliance date, 
will identify incomplete or inaccurate information or noncompliance 
with prescribed procedures and specify how much time you will have to 
submit additional information or comply with the total chlorine MACT 
standards. The permitting authority may extend the compliance date of 
the total chlorine MACT standards to allow you to make changes to the 
design or operation of the combustor or related systems as quickly as 
practicable to enable you to achieve compliance with the total chlorine 
MACT standards.
    Comment: One commenter states that proposed Sec.  63.1215(f)(1)(A) 
should have required sources to conduct a new comprehensive performance 
test only if there are changes that would decrease the HCl-equivalent 
emission rate limit below the HCl-equivalent emission rate demonstrated 
during the comprehensive performance test. Similarly, the commenter 
suggests that a retest should not be required if a change increases the 
HCl-equivalent emission rate limit but the source elects to maintain 
the current feedrate limit.
    Another commenter states that the Agency should clarify that if 
there are any changes that are not controlled by the facility owner/
operator, and the

[[Page 59485]]

facility is required to change its design or operation to lower 
chlorine emissions to address the changes, the facility may request up 
to three years to make such changes.
    Response: We generally agree with the commenters and have revised 
the rule as follows: (1) A new comprehensive performance test is 
required to reestablish the system removal efficiency for total 
chlorine only if you change the design, operation, or maintenance of 
the source in a manner that may decrease the system removal efficiency 
(e.g., the emission control system is modified in a manner than may 
decrease total chlorine removal efficiency); and (2) if you use the 
site-specific risk analysis option for your eligibility demonstration 
and changes beyond your control (e.g., off-site receptors newly 
residing or congregating at locations exposed to higher ambient levels 
than originally estimated) dictate a lower HCl-equivalent emission rate 
limit and you must make changes to the design, operation, or 
maintenance of the combustor or related systems to comply with the 
lower limit, you may request that the permitting authority grant you 
additional time to make those changes as quickly as practicable.
    Comment: Several commenters state that the proposed approach for 
calculating chlorine emissions to address the potential bias using 
Method 26/26A attributable to high bromine or sulfur levels in 
feedstreams is not statistically valid. They indicate that the approach 
could lead to collection of total chlorine, hydrogen chloride and 
chlorine data that are contradictory and difficult to apply in a 
compliance situation. One commenter suggests that using Method 26/26A 
results for sources with bromine and sulfur dioxide, while recognizing 
that there is bias in the sampling method, will result in a valid 
compliance approach.
    Response: We agree with commenters that the proposed approach to 
avoid the bias when feedstreams contain high levels of bromine or 
sulfur (bromine/chlorine ratio in feedstreams of greater than 5 
percent, or sulfur/chlorine ratio in feedstreams of greater than 50 
percent) during the comprehensive performance test may be problematic. 
The proposed approach would have required you to use Method 320/321 or 
ASTM D 6735-01 for hydrogen chloride measurements, to use Method 26/26A 
for total chlorine (i.e., hydrogen chloride and chlorine combined) 
measurements, and to calculate chlorine levels by difference. The 
potential problem is that chlorine emission levels are generally a very 
small portion of total chlorine measurements, and variability in the 
hydrogen chloride or total chlorine measurements due to method 
imprecision or other factors could result in inaccurate estimations of 
chlorine emission levels.
    We do not agree, however, that using Method 26/26A for chlorine 
measurements for combustors feeding high levels of bromine or sulfur is 
acceptable-the chlorine measurement may be biased low. Chlorine 
emission levels must be determined as accurately as possible given that 
the long-term health threshold for chlorine is 100 times the threshold 
for HCl, and the short-term health threshold for chlorine is 10 times 
the threshold for HCl (i.e., using current RfCs and aRELs). To ensure 
that a conservative estimate of the chlorine emission rate is used to 
establish the alternative health-based emission limits and to address 
commenters' concerns, the final rule requires that you determine 
chlorine emissions to be the higher of: (1) The chlorine value measured 
by Method 26/26A, or an equivalent method; or (2) the chlorine value 
calculated by difference between the combined hydrogen chloride and 
chlorine levels measured by Method 26/26A, or an equivalent method, and 
the hydrogen chloride measurement from EPA Method 320/321 or ASTM D 
6735-01, or an equivalent method.
    Comment: Several commenters state the procedures for calculating 
HCl-equivalent emission rates cannot merely reference an outside 
source, such as a Web site, unless that reference specifies that the 
contents of the source are as of a date certain. To specify use of 
health threshold values that can change over time provides inadequate 
opportunity for notice and comment on the regulation.
    Response: We believe that the best available sources of health 
effects information should be used for risk or hazard determinations. 
To assist us in identifying the most scientifically appropriate 
toxicity values for our analyses and decisions, the Web site to be used 
for RfCs identifies pertinent toxicity values using a default hierarchy 
of sources, with EPA's Integrated Risk Information System (IRIS) being 
the preferred source. The IRIS process contains internal and external 
peer review steps and IRIS toxicity values represent EPA consensus 
values. When adequate toxicity information is not available in IRIS, 
however, we consult other sources in a default hierarchy that 
recognizes the desirability of these qualities in ensuring that we have 
consistent and scientifically sound assessments. Furthermore, where the 
IRIS assessment substantially lags the current scientific knowledge, we 
have committed to consider alternative credible and readily available 
assessments (e.g., the acute Relative Exposure Levels established by 
the California Office of Health Hazard Assessment). For our use, these 
alternatives need to be grounded in publicly available, peer-reviewed 
information. We agree with the commenter that the issue of changing 
toxicity values is a general challenge in setting health-based 
regulations. However, we are committed to establishing such regulations 
that reflect current scientific understanding, to the extent feasible.

C. National Health-Based Standards for Cement Kilns

    Comment: One commenter states that our suggestion at proposal that 
it would be appropriate to establish a single national emission rate 
type standard applicable to all cement kilns based on the worst-case 
scenario cement kiln is unduly burdensome as it discounts the benefits 
of improved dispersion realized by facilities that have invested in 
taller stacks that minimize downwash effects. The commenter recommends 
a dual limit for cement kilns such that the HCl equivalent emission 
rate is limited to both: (1) A 130 ppmv total chlorine emission 
standard (the Interim Standard) coupled with a chlorine feedrate limit 
based on a 12-hour rolling average; and (2) a Hazard Index of 1.0.
    Response: We have decided not to include a separate national 
standard for cement kilns in the final rule for several reasons: (1) We 
have no assurance that the Cl<INF>2</INF>/HCl volumetric ratio 
exhibited during the most recent compliance test, and that was the 
basis for the commenter documenting in a study \187\ that the Hazard 
Index of 1.0\188\ was not exceeded, is representative of ratios in the 
past or future; (2) the commenter's recommended emission standard for 
cement kilns--130 ppmv total chlorine emission limit and a Hazard Index 
of 1.0--is equivalent to the requirements under Sec.  63.1215 
applicable to other hazardous waste combustors to establish site-
specific emission limits; (3) the MACT standard for total chlorine for 
cement kilns is 120 ppmv such that the health-based standard that the 
commenter recommends--130 ppmv,

[[Page 59486]]

the Interim Standard--would provide little compliance relief; and (4) 
even though the final rule does not provide a separate national health-
based standard for cement kilns, cement kilns may apply for the health-
based compliance alternatives applicable to other hazardous waste 
combustors.
---------------------------------------------------------------------------

    \187\ See Trinity Consultants, ``Analysis of HCl/Cl2 Emissions 
from Cement Kilns for 112(d)(4) Consideration in the HWC MACT 
Replacement Standards,'' September 17, 2003.
    \188\ The HCl/Cl<INF>2</INF> ratio for the total chlorine 
measurement is important because the current RfC for chlorine is 0.2 
[mu]g/m\3\ while the current RfC for HCl is 20 [mu]g/m\3\. Thus, 
when calculating HCl-equivalent emission rate limits, chlorine 
emissions are currently multiplied by a factor of 100.
---------------------------------------------------------------------------

    Prior to publication of the proposed rule, the commenter submitted 
results of site-specific risk assessments for all cement kiln 
facilities showing that both the long-term and short term Hazard Index 
of 1.0 would not be exceeded at any facility assuming: (1) Sources emit 
total chlorine at the Interim Standard level of 130 ppmv; and (2) total 
chlorine emissions are apportioned between HCl and chlorine according 
to the apportionment exhibited during the most recent compliance test.
    At proposal, we requested comment on how to ensure that the 130 
ppmv concentration-based standard would ensure that total chlorine 
emission rates (lb/hr) would not increase to levels that may exceed the 
Hazard Index limit of 1.0 given that: (1) The partitioning ratio 
between HCl and chlorine could change over time such that a larger 
fraction of total chlorine could be emitted as chlorine, which has a 
much lower health risk threshold; and (2) the mass emission rate of 
total chlorine could increase. See 69 FR at 21306.
    The commenter has addressed the concern about the mass emission 
rate of total chlorine potentially increasing by suggesting that the 
health-based standard include a limit on the feedrate of total chlorine 
and chloride at the level used in their risk assessment supporting a 
separate national standard for cement kilns. The commenter has also 
addressed the concern about the HCl and chlorine apportionment ratio 
changing over time by suggesting that the standard also include a 
requirement that the Hazard Index of 1.0 not be exceeded. We agree that 
sources need to account for variability in the chlorine to HCl ratio 
(see Sec.  63.1215(b)(6)) and that periodic checks to ensure that the 
Hazard Index of 1.0 is not exceeded are needed. We believe the best way 
to ensure that the health-based compliance alternatives for total 
chlorine for cement kilns are protective with an ample margin of safety 
is through the procedures of Sec.  63.1215 where site-specific emission 
rate limits are established rather than under a separate national 
standard for cement kilns.

VIII. Implementation and Compliance

A. Compliance Assurance Issues for both Fabric Filters and 
Electrostatic Precipitators (and Ionizing Wet Scrubbers)

1. Implementation Issues
    Comment: Several commenters state that design and performance 
specifications and explicit detailed test procedures to determine 
conformance with the specifications are needed so that manufacturers 
can certify that their bag leak detection systems and particulate 
matter detection systems meet applicable criteria. Absent design and 
performance specifications and test procedures, commenters assert that 
the ``manufacturer's certification'' cannot ensure the performance 
capabilities of the devices.
    Response: In general, we believe adherence to manufacturer's 
written specifications and recommendations is an appropriate approach 
to reasonably ensure performance of a bag leak detection system or 
particulate matter detection system, and we have retained that 
provision in the final rule. We agree, however, that there may be cases 
where other procedures are more appropriate than the manufacturer's 
recommendations to ensure performance of a bag leak detection system or 
particulate matter detection system. Consequently, the rule allows you 
to request approval for alternative monitoring procedures under Sec.  
63.1209(g)(1).\189\ We note that you may use references other than 
EPA's Guidance Document, ``Fabric Filter Bag Leak Detection Guidance,'' 
September 1997 to identify appropriate performance specifications for 
the bag leak detection system or particulate matter detection system, 
including: PS-11 for PM CEMS; PS-1 for opacity monitors; and CPS-001 
for opacity monitoring below 10% opacity. You may use these references 
to support your request for additions to, or deviations from, 
manufacturer's specifications.
---------------------------------------------------------------------------

    \189\ See discussion in Part Five, Section III.C, for an 
explanation of how the alternative monitoring provisions of Sec.  
63.1209(g)(1) relate to those of Sec.  63.8(f).
---------------------------------------------------------------------------

    Comment: One commenter states that bag leak detection systems and 
particulate matter detection systems should have a detection limit of 
1.0 mg/acm to ensure peak performance is maintained rather than 
explicitly allowing sources to request approval for a detection limit 
on a site-specific basis as the rule currently allows. Several other 
commenters state that the bag leak detection system or particulate 
matter detection system need not have a detection limit as low as 1.0 
mg/acm to detect increases in normal emissions. One commenter believes 
that bag leak detection systems installed on cement kilns should be 
allowed to have a detection limit of 10 mg/acm because: (1) A detection 
limit requirement of 10 mg/acm is more than sufficient to protect the 
particulate matter emission limit and to detect increases in 
particulate matter concentration given that the current particulate 
matter emission limit for existing kilns is 63 mg/dscm; (2) a detection 
limit requirement of 10 mg/acm is consistent with the requirement for 
bag leak detection systems in Subpart LLL, Part 63, for cement plants 
that choose to install bag leak detection systems on finish mills and 
raw mills, for bag leak detection systems and particulate matter 
detection systems installed on lime kilns under Subpart AAAAAA, and for 
industrial boilers under Subpart DDDDD; (3) a 10 mg/acm detection limit 
is achievable using state-of-the-art transmissometers (the actual 
instrument used in a continuous opacity monitoring system (COMS) at 
cement plants having kiln stack diameters of 2-3 meters, or greater; 
and (4) it is unclear if any bag leak detection system device can 
actually be demonstrated to achieve a 1.0 mg/acm detection limit except 
by extrapolation from tests conducted at higher dust loadings and 
theoretical arguments based on signal-to-noise ratios or other 
parameters. This commenter also recommends that EPA establish a 10 mg/
am\3\ detection limit for all cement kilns rather than provide for 
site-specific determinations because allowing site-specific 
determinations is likely to create confusion in the selection of 
monitoring devices and further complicate the manufacturer's 
certification of performance requirements.
    Response: The current requirement for the bag leak detection system 
sensitivity/detection limit applicable to incinerators and lightweight 
aggregate kilns is 1.0 mg/acm unless you demonstrate under Sec.  
63.1209(g)(1) that a lower sensitivity (i.e., higher detection limit) 
would detect bag leaks. We proposed to apply the bag leak detection 
system requirements to all hazardous waste combustors equipped with 
fabric filters and promulgate that requirement today. Although we also 
requested comment whether detection limits higher than 1.0 mg/acm 
should be allowed, none of the comments has convinced us to alter our 
view that the rule should allow higher detection limits on a site-
specific basis. Similarly,

[[Page 59487]]

we believe that the same detection limit requirement should apply to 
particulate matter detection systems that you may elect to use for 
compliance monitoring for your electrostatic precipitator or ionizing 
wet scrubber in lieu of site-specific operating parameter limits.
    Both bag leak detection systems and particulate matter detection 
systems must be able to detect particulate emission in the range of 
normal concentrations. For example, to establish the alarm level for 
the bag leak detection system, you must first adjust detector gain/
sensitivity and response time based on normal operations. Although the 
alarm level for particulate matter detection systems will be 
established based on operations during the comprehensive performance 
test or higher (see discussion below), the detector must be responsive 
within the range of normal operations for you to effectively minimize 
exceedances of the alarm level.
    The range of normal emission concentrations will generally be well 
below both the particulate matter standard and emissions during the 
comprehensive performance test. Consequently, we disagree with 
commenters that believe the detection limit need only be within the 
range of emissions at the particulate matter emission standard. On the 
other hand, normal emissions may be well above 1.0 mg/acm such that a 
higher detection limit (e.g., 10 mg/acm) may be appropriate on a site-
specific basis.
    We also disagree with the comment that bag leak detection systems 
(or particulate matter detection systems) may not be able actually to 
achieve a 1.0 mg/acm detection limit. EPA is aware of bag leak 
detection system instruments certified to meet levels of 0.2 mg/m\3\ 
and particulate matter detection systems can readily achieve detection 
limits well below 1.0 mg/acm.\190\
---------------------------------------------------------------------------

    \190\ USEPA, ``Technical Support Document for HWC MACT 
Standards, Volume IV: Compliance with the HWC MACT Standards,'' 
September 2005, Appendix C, Section 4.0.
---------------------------------------------------------------------------

    Comment: One commenter states that a continuous opacity monitoring 
system (COMS) that can achieve a detection level of 10 mg/acm or less 
can be used to monitor electrostatic precipitator performance. The 
commenter believes that allowing a COMS for compliance under Subpart 
EEE is also appropriate because cement kilns will be operating under 
the requirements of Subpart LLL (for cement kilns that do not burn 
hazardous waste) at times, which requires compliance with an opacity 
standard using a COMS.
    Response: You may use a COMS (i.e., transmissometer) that meets the 
detection limit requirement as discussed above (i.e., 1.0 mg/acm or a 
higher detection limit that you document under an alternative 
monitoring petition under Sec.  63.1209(g)(1) would routinely detect 
particulate matter loadings during normal operations) as the detector 
for your bag leak detection system or particulate matter detection 
system.
2. Compliance Issues
    Comment: One commenter states that, if the bag leak detection 
system or particulate matter detection system exceeds the alarm level 
or an operating parameter limit (OPL) is exceeded, the automatic waste 
feed cutoff (AWFCO) system must be initiated. Allowing a source to 
exceed the alarm level for 5% of the time in a 6-month period does not 
ensure continuous compliance.
    Response: Although the AWFCO system must be initiated if an OPL is 
exceeded, we believe that allowing exceedances of the bag leak 
detection system or particulate matter detection system alarm level up 
to 5% of the time in a 6-month period is reasonable. Requiring 
initiation of the AWFCO for an exceedance of an OPL is reasonable 
because sources generally can control directly the parameter that is 
limited. Examples are the feedrate of metals or chlorine, or pressure 
drop across a wet scrubber. Bag leak detection systems and particulate 
matter detection systems, however, measure mass emissions of 
particulate matter, a parameter that is affected by many interrelated 
factors and that is not directly controllable. We believe that the 5 
percent alarm rate is a reasonable allowance for sources due to 
difficult-to-control variations in particulate matter emissions. More 
important, although the bag leak detection system and particulate 
matter detection system measure mass emissions of particulate matter, 
the detector response is not correlated to particulate matter emission 
concentrations to the extent necessary for compliance monitoring.\191\ 
Thus, triggering the alarm level is not evidence that the particulate 
matter emission standard has been exceeded.
---------------------------------------------------------------------------

    \191\ Actually, the BLDS is not correlated at all to PM 
concentrations, and the alarm level for a PMDS may or may not be 
approximately correlated to PM concentrations. See Sec.  
63.1206(c)(9).
---------------------------------------------------------------------------

    The purpose of a BLDS or PMDS is to alert the operator that the PM 
control device is not functioning properly and that corrective measures 
must be undertaken. We believe that using a BLDS or PMDS for compliance 
assurance better minimizes emissions of PM (and metal HAP) than use of 
operating parameter limits (which are linked to the automatic waste 
feed cutoff system). APCD operating parameters often have an uncertain 
relationship to PM emissions while the BLDS and PMDS provide real-time 
information on actual PM mass emission levels.\192\
---------------------------------------------------------------------------

    \192\ Moreover, for FFs, we are not aware of any APCD operating 
parameters that correlate well with PM emissions. Thus, sources must 
use a BLDS or PMDS for compliance assurance. For ESPs and IWSs, we 
are not aware of generic APCD parameters that correlate well with PM 
emissions. See discussion below in Section VIII.C of the text. 
Consequently, although the rule allows sources with ESPs and IWSs to 
establish site-specific operating parameter limits, sources are 
encouraged to use a PMDS.
---------------------------------------------------------------------------

    Comment: One commenter states that requiring a notification if the 
bag leak detection system or particulate matter detection system set 
point is exceeded more than 5% of the time in a 6-month period is not 
cost-effective. Sources using bag leak detection systems have not 
linked exceedances to the data logging system and would incur an 
expense to do so.
    Response: We continue to believe that limiting the aggregate 
duration of exceedances in a 6-month period is a reasonable approach to 
gage the effectiveness of the operation and maintenance procedures for 
the combustor. We note that recent MACT standards for several other 
source categories use this approach, including standards for industrial 
boilers and process heaters and standards for lime kilns.
    Comment: One commenter states that EPA did not present a rationale 
for requiring a notification within 5 working days if the bag leak 
detection system or particulate matter detection system set point is 
exceeded more than 5% of the time during a 6-month period. The 
commenter notes that this notice is not required under the Subpart 
DDDDD boiler and process heater MACT. The commenter also notes that the 
source is required to take corrective measures under both the operation 
and maintenance plan and bag leak detection systems and particulate 
matter detection systems requirements. The commenter believes that 
requiring a report to the permitting authority is duplicative, 
unnecessary, and increases the burden on regulated facilities without 
providing additional protection to human health or the environment.
    Response: If a source exceeds the alarm set point more than 5% of 
the time in a 6-month period, it is an indication that the operation 
and maintenance plan may need to be revised. Requiring the source to 
report the excess exceedances to the permitting

[[Page 59488]]

authority serves as a notification that the authority may need to 
review the operation and maintenance plan with the source to determine 
if changes are warranted.
    We agree with the commenter, however, that it is not necessary to 
require that the report be submitted within five working days of the 
end of the 6-month block period. Consequently, the final rule requires 
you to submit the report within 30 days of the end of the 6-month block 
period. Allowing 30 days to submit the report rather than 5 days as 
proposed is reasonable. We are concerned that 5 days may not be enough 
time to complete the report given that several exceedances toward the 
end of the 6-month block period may cause you to exceed the 5% time 
limit and that there may be many individual exceedances that need to be 
included in the report. We acknowledge that it may take some time to 
prepare the report given that you must describe the causes of each 
exceedance and the revisions to the operation and maintenance plan you 
have made to mitigate the exceedances.
    Comment: One commenter notes that there is no guidance on how to 
calculate when the set-point has been exceeded more than 5 percent of 
the operating time within a 6 month period. The commenter notes that 
the MACT for industrial boilers and process heaters provides minimal 
instruction on how this is to be done, but it is not specific enough to 
enable facilities to ensure that they are in compliance with this 
requirement.
    Response: For the final rule, we have adopted the procedures 
specified in the industrial boiler and process heater MACT for 
calculating the duration of exceedances of the set point. Those 
procedures are as follows:
    1. You must keep records of the date, time, and duration of each 
alarm, the time corrective action was initiated and completed, and a 
brief description of the cause of the alarm and the corrective action 
taken.
    2. You must record the percent of the operating time during each 6-
month period that the alarm sounds.
    3. In calculating the operating time percentage, if inspection of 
the fabric filter, electrostatic precipitator, or ionizing wet scrubber 
demonstrates that no corrective action is required, no alarm time is 
counted.
    4. If corrective action is required, each alarm shall be counted as 
a minimum of 1 hour.
    Although the commenter indicates that these procedures are not 
specific enough to ensure that sources are in compliance with the 
requirements, the commenter did not indicate the deficiencies or 
suggest additional requirements. If you need additional guidance on 
compliance with this provision, you should contact the permitting 
authority.
    Comment: One commenter supports the approach of listing the 
shutting down of the combustor as a potential--but not mandatory--
corrective measure in response to exceeding an alarm set point. Several 
commenters suggest, however, that EPA should specify that corrective 
measures could include shutting off the hazardous waste feed rather 
than shutting down the combustor. Other commenters state that it is 
inappropriate to imply that shutting down the combustor must be part of 
a corrective measures program for responding to exceedance of a set 
point. These commenters believe that the requirement to take corrective 
action upon the alarm is sufficiently protective. The facility should 
determine if shutting down the combustor is a necessary response to 
avoid noncompliance with a standard.
    Response: You must operate and maintain the fabric filter, 
electrostatic precipitator, or ionizing wet scrubber to ensure 
continuous compliance with the particulate matter, semivolatile metals, 
and low volatile metals emission standards. Your response to exceeding 
the alarm set point should depend on whether you may be close to 
exceeding an operating parameter limit (e.g., ash feedrate limit for an 
incinerator or liquid fuel boiler equipped with an electrostatic 
precipitator) or an emission standard. If so, corrective measures 
should include, as commenters suggest, cutting off the hazardous waste 
feed. Corrective measures could also include, however, shutting down 
the combustor as the ultimate immediate corrective measure if an 
emission standard may otherwise be exceeded. Consequently, the final 
rule continues to require you to alleviate the cause of the alarm by 
taking the necessary corrective measure(s) which may include shutting 
down the combustor. This provision does not imply that shutting down 
the combustor is the default corrective measure. Rather, it implies 
that the ultimate immediate response, absent other effective corrective 
measures, would be to shut down the combustor.
    Comment: One commenter states that periods of time when the 
combustor is operating but the bag leak detection system or particulate 
matter detection system is malfunctioning should not be considered 
exceedances of the set-point.
    Response: If the bag leak detection system or particulate matter 
detection system is malfunctioning, the source cannot determine whether 
it is operating within the alarm set point. Accordingly, it is 
reasonable to consider periods when the bag leak detection system or 
particulate matter detection system is malfunctioning as exceedances of 
the set point.

B. Compliance Assurance Issues for Fabric Filters

    Comment: One commenter states that establishing the set point for 
the bag leak detection system at twice the detector response achieved 
during bag cleaning as recommended by EPA guidance would not be 
sensitive enough to detect gradual degradation of the fabric filter, 
nor would it be low enough to require the operator of the source to 
take corrective measures that would ensure effective operation of the 
baghouse over time.
    Response: The commenter expresses the same concern that EPA raised 
at proposal. See 69 FR at 21347. We have concluded, however, that it 
may be problematic to establish an alarm set point for fabric filters 
based on operations during the comprehensive performance test. This is 
because, as noted in earlier responses and at 69 FR at 21233, it is 
much more difficult to ``detune'' a fabric filter than an electrostatic 
precipitator to maximize emissions during the performance test.\193\ 
Consequently, emissions from fabric filters that have not been detuned 
during the performance test may not be representative of the range of 
normal emissions caused by factors such as bag aging. Baghouse 
performance degrades over time as bags age. In addition, establishing 
the alarm set point based on operations during the performance test for 
baghouses that have not been detuned would establish more stringent 
compliance requirements on sources that perform the best--the lower the 
emissions, the lower the alarm set point. This would unfairly penalize 
the best performing sources.
---------------------------------------------------------------------------

    \193\ One approach to detune a fabric filter to simulate the 
extreme high range of normal operations would be to install a 
butterfly valve that allows a portion of the combustion gas to by-
pass a section of the baghouse.
---------------------------------------------------------------------------

    For these reasons, the final rule requires you to establish the 
alarm set-point for bag house detection systems using principles 
provided in USEPA, ``Fabric Filter Bag Leak Detection Guidance,'' (EPA-
454/R-98-015, September 1997).
    Comment: One commenter states that the bag leak detection system 
requirement should not apply to the coal mill baghouse for cement kilns 
with indirect-fired coal mill systems where a fraction of kiln gas is 
taken

[[Page 59489]]

from the preheater and routed to the coal mill and subsequently to a 
baghouse before entering the stack. The commenter notes that the PM in 
this gas is nearly exclusively coal dust, and the baghouse is 
substantially smaller than the baghouse for the kiln.
    Response: We believe that a bag leak detection system is a 
reasonable approach to monitor emissions for the coal mill baghouse to 
ensure compliance with the particulate matter (and semivolatile and low 
volatile metals) emission standards. These systems are inexpensive to 
install and operate. Annualized costs are approximately $24,000.\194\ 
Although the commenter did not suggest an alternative monitoring 
approach, and we are not aware of a less expensive and effective 
approach, we note that sources may petition the permitting authority 
under Sec.  63.1209(g)(1) to request an alternative monitoring 
approach.
---------------------------------------------------------------------------

    \194\ USEPA, ``Technical Support Document for HWC MACT 
Standards, Volume IV: Compliance with the HWC MACT Standards,'' 
September 2005, Appendix C.
---------------------------------------------------------------------------

C. Compliance Issues for Electrostatic Precipitators and Ionizing Wet 
Scrubbers

    Comment: Several commenters believe that a particulate matter 
detection system may not be necessary for monitoring of electrostatic 
precipitators and ionizing wet scrubbers. Commenters state that site-
specific operating parameter limits linked to the automatic waste feed 
cutoff system can effectively monitor and ensure the performance of 
electrostatic precipitators and ionizing wet scrubbers. Particulate 
matter detection systems on cement kilns would have to operate in a 
high moisture stack environment (all kilns burning hazardous waste that 
are equipped with electrostatic precipitators are wet process kilns), 
with the potential for condensation and/or water droplet interference. 
Commenters state that when water droplets are present, many of these 
devices are not applicable.
    Response: The final rule provides sources equipped with 
electrostatic precipitators or ionizing wet scrubbers the alternative 
of using a particulate matter detection system or establishing site-
specific operating parameter limits for compliance assurance. If a 
particulate matter detection system is used, corrective measures must 
be taken if the alarm set point is exceeded. If the source elects to 
establish site-specific operating parameter limits, the limits must be 
linked to the automatic waste feed cutoff system.
    In response to commenters' concern that high moisture stack gas may 
be problematic for particulate matter detection systems, we note that 
extractive light-scattering detectors and beta gauge detectors can 
effectively operate in high moisture environments. We acknowledge, 
however, that the cost of these extractive detector systems is 
substantially higher than transmissometers or in situ light-scattering 
detectors.
    Comment: One commenter states that EPA must set minimum total power 
requirements for both ionizing wet scrubbers and electrostatic 
precipitators because allowing permit officials to establish compliance 
operating parameters on a site-specific basis frustrates the intention 
of the CAA by obviating the requirements for federal standards. The 
commenter asserts that a minimum total power requirement is 
monitorable, recordable, and reportable, three requirements that are 
necessary for these facilities to come into, and remain in compliance 
with, their Title V operating permits.
    Other commenters state that electrostatic devices are not easily 
characterized by operating parameters in a ``one-size-fits-all'' 
fashion. The significant operating parameters for electrostatic devices 
are secondary voltage, secondary current, and secondary power (the 
product of the first two items). The relationship between these 
parameters and performance of the unit differ between applications and 
unit types. For example, inlet field power can increase as unit 
performance appears to decrease. In this case, an operating parameter 
other than secondary power by field would be more appropriate. The 
commenter notes that, in its various proposals over the years, EPA has 
discussed a number of approaches to establish operating parameter 
limits for electrostatic devices, including: Minimum total secondary 
power; minimum secondary power by field; pattern of increasing power 
from inlet to outlet field; and minimum secondary power of the last \1/
3\ of fields (or the last field). Commenters have also proposed: 
minimum specific power (secondary power divided by flue gas flow rate); 
minimum secondary voltage and/or secondary current; and total secondary 
voltage and/or secondary current. The commenter concludes that it is 
not surprising that there is so little agreement on the right approach, 
because different units and applications respond differently. EPA's 
proposal to let facilities and local regulators determine the best 
approach is far wiser than regulating from a distance.
    Response: We agree with the commenters that state that it is not 
practicable to establish operating parameter limits that would 
effectively ensure performance of all electrostatic devices. 
Accordingly, the final rule continues to allow sources to establish 
site-specific operating parameter limits for these devices.
    We disagree with the commenter's assertion that site-specific 
operating parameter limits obviate the requirements for federal 
standards. The site-specific operating parameter limits merely reflect 
the truism that no two sources are identical and so what each needs to 
do to comply with the uniform standards may differ. The final rule 
provides consistent, federally-enforceable emission standards. 
Necessary flexibility in compliance assurance for those emission 
standards does not undermine the uniformity of those standards. In 
addition, we disagree with the commenter's concern that without a 
minimum power limit, there will be no monitorable, recordable, and 
reportable Title V permit limits for electrostatic devices. To the 
contrary, site-specific operating parameter limits can and will be 
monitored, recorded, reported, and linked to the automatic waste feed 
cut-off system. And, if a source elects to use a particulate matter 
detection system in lieu of establishing site-specific operating 
parameter limits, the detector response will be monitored, recorded, 
reported, and linked to requirements to take corrective measures if the 
alarm set point is exceeded.
    Comment: One commenter asserts that the use of electrostatic 
precipitator total power input data (sum of the product of kilovolts 
times milliamps for each electrostatic precipitator field) is one 
acceptable approach as a site-specific parameter to monitor 
electrostatic precipitator performance. Limits on power input for each 
field (or particular fields) are not warranted.
    Response: A limit on total power input to a multifield 
electrostatic device is generally not an acceptable operating parameter 
for compliance assurance. We have documented that when total power 
input was held constant for a four-field electrostatic precipitator 
while the power input to the fourth field was decreased, emissions of 
particulate matter doubled from 0.06 gr/dscf to 0.12 gr/dscf. See 66 FR 
at 35143 (July 3, 2001). Thus, if the total power input during the 
comprehensive performance test were used as the operating parameter 
limit, particulate matter emissions could exceed the emission

[[Page 59490]]

standard because of changes in other parameters that were not limited 
even though total power input did not exceed the parametric limit.
    Notwithstanding our concern that a limit on total power input to a 
multifield electrostatic device is generally not an effective operating 
parameter for compliance assurance, this does not preclude you from 
documenting to the permitting authority that total power input is an 
effective compliance assurance parameter for your source. See Sec.  
63.1209(m)(1)(iv).
    Comment: Several commenters suggest that the rule should offer 
various approaches to establish an achievable particulate matter 
detection system alarm level on a site-specific basis in lieu of the 
approach we proposed (i.e., average detector response during the 
comprehensive performance test): (1) Use the 2 times the maximum peak 
height or 3 times the baseline concepts developed in EPA's bag leak 
detection guidance documents; (2) allow spiking to set the alarm set 
point given that PS 11 allows for spiking as a way to calibrate PM 
CEMs; (3) establish the limit as the 99th percentile upper prediction 
limit of the average response during each performance test run instead 
of the average of the test run averages; (4) allow upward extrapolation 
from the average of the test run averages to some percentage of the 
particulate matter emissions standard (fraction could be variable 
depending upon how close to the standard the facility is during the 
compliance test); or (5) set the alarm point at the maximum test run.
    Response: We agree with several of the commenters' suggestions: 
explicitly allowing spiking (and emission control device detuning) 
during the comprehensive performance test to maximize controllable 
operating parameters to simulate the full range of normal operations; 
and upward extrapolation of the detector response. See discussion 
below.
    The final rule is consistent with commenters' suggestion to 
establish the alarm level for particulate matter detection systems on 
fabric filters based on the concepts in the Agency's guidance document 
on bag leak detection systems. Commenters made this suggestion in 
response to our request for comments on requiring particulate matter 
detection systems on fabric filters and establishing the alarm level 
based on the detector response during the comprehensive performance 
test. See 69 FR at 21347. The final rule requires bag leak detection 
systems on all fabric filters and suggests that you establish the alarm 
level using concepts in the bag leak detection system guidance. \195\
---------------------------------------------------------------------------

    \195\ Note that a bag leak detection system is a type of 
particulate matter detection system for purposes of this discussion. 
A triboelectric detector is normally used for a bag leak detector 
system because it is very inexpensive and has a low detection limit. 
A triboelectric detector meets the criterion for a particulate 
matter detector in a particulate matter detection system in that it 
detects relative mass emissions of particulate matter within the 
range of normal emission concentrations. (Note further, however, 
that a triboelectric detector cannot be correlated to particulate 
matter concentrations and thus cannot be used as a particulate 
matter CEMS. Note also that a triboelectric detector cannot be used 
on sources equipped with electronic control devices.) The alarm 
level for a bag leak detection system would be established using the 
concepts discussed in the Agency's guidance document on bag leak 
detection systems. The alarm level for a particulate matter 
detection system used on a fabric filter, however, (preferable with 
a detector other than a tribolectric device that could be correlated 
to PM concentrations) would be established based on the detector 
response during the comprehensive performance test.
---------------------------------------------------------------------------

    Neither the suggestion to establish the alarm level at the 99th 
percentile upper prediction limit (UPL99) based on the average response 
during the comprehensive performance test runs nor the suggestion to 
establish the alarm level at the maximum test run response would 
control PM emissions at the level achieved during the performance test 
or provide some assurance that the PM standard was not being exceeded, 
unless the detector response is correlated to PM concentrations. For 
example, if the detector response does not relate linearly to PM 
concentration (or if the response changes w/changes in particulate 
characteristics), the UPL99 detector response could relate to a much 
higher (e.g., 99.9th percentile) PM concentration. In addition, even if 
the detector response were correlated to PM concentration, there is no 
assurance that the correlation would be consistent over the range of 
the average detector response during the performance test to the UPL99 
detector response. Note that under PS-11 for PM CEMS, even after 
complying with rigorous procedures to correlate the detector response 
to PM concentrations, the detector response may be extrapolated only to 
125% of the highest PM concentration used for the correlation. Thus, 
the final rule does not use these approaches to establish the alarm 
level.
    If you elect to use a particulate matter detection system in lieu 
of site-specific operating parameters for your electrostatic 
precipitator or ionizing wet scrubber, you must establish the alarm 
level using either of two approaches. See Appendix C of USEPA, 
``Technical Support Document for HWC MACT Standards, Volume IV: 
Compliance with the HWV MACT Standards,'' September 2005. Under either 
approach, you may maximize controllable operating parameters during the 
comprehensive performance test to simulate the full range of normal 
operations (e.g., by spiking the ash feedrate and/or detuning the 
electrostatic device).\196\
---------------------------------------------------------------------------

    \196\ Note, however, that bypassing or detuning an emission 
control system could cause PM stratification and could make it 
difficult to pass the PS-11 performance criteria you use as 
guidelines for a PMDS.)
---------------------------------------------------------------------------

    You may establish the alarm set-point as the average detector 
response of the test condition averages during the comprehensive 
performance test.
    Alternatively, you may establish the alarm set point by 
extrapolating the detector response. Under the extrapolation approach, 
you must approximate the correlation between the detector response and 
particulate matter emission concentrations during an initial 
correlation test. You may extrapolate the detector response achieved 
during the comprehensive performance test (i.e., average of the test 
condition averages) to the higher of: (1) A response that corresponds 
to 50% of the particulate matter emission standard; or (2) a response 
that correlates to 125% of the highest particulate matter concentration 
used to develop the correlation.
    To establish an approximate correlation of the detector response to 
particulate matter emission concentrations, you should use as guidance 
Performance Specification-11 for PM CEMS (40 CFR Part 60, Appendix B), 
except that you need only conduct only 5 runs to establish the initial 
correlation rather than a minimum of 15 runs required by PS-11. In 
addition, the final rule requires you to conduct an annual Relative 
Response Audit (RRA) for quality assurance as required by Procedure 2--
Quality Assurance Requirements for Particulate Matter Continuous 
Emission Monitoring Systems at Stationary Sources, Appendix F, Part 
60.\197\ The RRA is required on only a 3-year interval, however, after 
you pass two sequential annual RRAs.
---------------------------------------------------------------------------

    \197\ You perform an RRA by collecting three simultaneous 
reference method PM concentration measurements and PM CEMS 
measurements at the as-found source operating conditions and PM 
concentration.
---------------------------------------------------------------------------

    The rule requires only minimal correlation testing because the 
particulate matter detection system is used for compliance assurance 
only--as an indicator for reasonable assurance that an emission 
standard is not exceeded. The particulate matter detection system is 
not used for compliance monitoring--as an indicator of continuous 
compliance with an

[[Page 59491]]

emission standard. Because particulate matter detection system 
correlation testing and quality assurance is much less rigorous than 
the requirements of PS-11 for a PM CEMS, the particulate matter 
detection system response cannot be used as credible evidence of 
exceedance of the emission standard.

D. Fugitive Emissions

    Comment: A commenter does not support EPA's proposed approach to 
allow alternative techniques that can be demonstrated to prevent 
fugitive emissions without the use of instantaneous pressure limits 
given that the CAA requires continuous compliance with the standards 
and given positive pressure events can result in fugitive emissions, 
irrespective of facility design.
    Response: Rotary kilns can be designed to prevent fugitive 
emissions during positive pressure events. As stated in the February 
14, 2002 final rule, and subsequently in the April 20, 2004 proposed 
rule, there are state-of-the-art rotary kiln seal designs (such as 
those with shrouded and pressurized seals) which are capable of 
handling positive pressures without fugitive releases. See 67 FR at 
6973 and 69 FR at 21340. We have included documentation of such kiln 
designs in the docket.\198\ Instantaneous combustion zone pressure 
limits thus may not be necessary to assure continuous compliance with 
these fugitive emission control requirements. Our approach to allow 
alternative techniques that have been demonstrated to prevent fugitive 
emissions is therefore reasonable and appropriate. We note that these 
alternative techniques must be reviewed and approved by the appropriate 
delegated regulatory official.\199\
---------------------------------------------------------------------------

    \198\ See USEPA, ``Technical Support Document for the HWC MACT 
Standards, Volume IV: Compliance With the HWC MACT Standards,'' 
September 2005, Section 10.
    \199\ See Sec.  63.1206(c)(5)(i)(C) and (D).
---------------------------------------------------------------------------

    Comment: A commenter disagrees with EPA's clarification that 
fugitive emission control requirements apply only to fugitives 
attributable to the hazardous waste, given that the CAA does not 
distinguish between HAP emissions that come from hazardous waste 
streams and other HAP emissions.
    Response: The fugitive emission control requirements in today's 
final rule originated from the RCRA hazardous waste combustion fugitive 
emission control requirements for incinerators and boilers and 
industrial furnaces.\200\ The primary focus of these RCRA requirements 
is to ensure hazardous waste treatment operations are conducted in a 
manner protective of human health and the environment.\201\ It is 
therefore appropriate to clarify that the intent of this requirement is 
to control fugitive emission releases from the combustion of hazardous 
waste.
---------------------------------------------------------------------------

    \200\ See Sec.  266.102(e)(7) and Sec.  264.345(d).
    \201\ Section 3004(a) of RCRA requires the Agency to promulgate 
standards for hazardous waste treatment, storage, and disposal 
facilities as necessary to protect human health and the environment. 
The standards for hazardous waste incinerators generally rest on 
this authority. Sec.  3004(q) of RCRA requires the Agency to 
promulgate standards for emissions from facilities that burn 
hazardous waste fuels (e.g., cement and lightweight aggregate kilns, 
boilers, and hydrochloric acid production furnaces) as necessary to 
protect human health and the environment.
---------------------------------------------------------------------------

    Furthermore, MACT requirements for source categories that do not 
combust hazardous waste (e.g., industrial boilers, Portland cement 
kilns, and commercial and industrial solid waste incinerators) do not 
have combustion chamber fugitive emission control requirements for the 
non-hazardous waste inputs or outputs (e.g., clinker product for cement 
kilns or coal and natural gas fuels for industrial boilers). We have 
previously taken the position that emissions not affected by the 
combustion of hazardous waste (e.g., clinker coolers, raw material 
handling operations, etc.) are regulated pursuant to the applicable 
nonazardous waste MACT rules.\202\, \203\ We conclude the clarification 
that the fugitive emission control requirements applies only to 
fugitive emissions that result from the combustion of hazardous waste 
is appropriate because it regulates emissions attributable to 
nonhazardous waste streams to the same level of stringency that 
otherwise would apply if the source did not combust hazardous 
waste.\204\
---------------------------------------------------------------------------

    \202\ See 69 FR at 21203 and 64 FR at 52871, and Sec.  
63.1206(b)(1)(ii).
    \203\ Portland cement manufacturing facilities that combust 
hazardous waste are subject to both Subpart EEE and Subpart LLL, and 
hydrochloric acid production facilities that combust hazardous waste 
may be subject to both Subpart EEE and Subpart NNNNN. In these 
instances Subpart EEE controls HAP emissions from the cement kiln 
and hydrochloric acid production furnace stack (and also fugitive 
emissions from the combustion chamber), while Subparts LLL and NNNNN 
would control HAP emissions from other operations that are not 
directly related to the combustion of hazardous waste (e.g., clinker 
cooler emissions for cement production facilities, and hydrochloric 
acid product transportation and storage for hydrochloric acid 
production facilities).
    \204\ This issue has little relevance given that the measures 
taken to control the fugitive emissions from the combustion of 
hazardous waste will also control the fugitive emission associated 
with other feedstreams.
---------------------------------------------------------------------------

    Comment: A commenter states that the instantaneous monitoring 
requirements are inappropriate because (1) EPA has not demonstrated 
that the average of the top 12% of boilers are capable of operating 
with no instantaneous deviations from the negative pressure 
requirements; and (2) these requirements, though not standards 
themselves, effectively increase the stringency of the standard itself 
beyond what even the best available technology can achieve.
    Response: As previously discussed, the fugitive emission control 
requirements included in today's rule originated from the RCRA 
hazardous waste combustion chamber fugitive emission control 
requirements. These provisions allow sources to control fugitive 
emissions by ``maintaining the combustion zone pressure lower than 
atmospheric pressure, or an alternative means of control equivalent to 
maintenance of combustion zone pressure lower than atmospheric 
pressure.'' All sources that must comply with the provisions of this 
rule are, or were, required to control fugitive emissions from the 
combustion unit pursuant to RCRA.
    The monitoring requirements in today's rule do not increase the 
stringency of the standard beyond what the best available technology 
can achieve. Although we do not have data that confirm negative 
pressure is being maintained on an instantaneous basis (as we define 
it)\205\ for at least 12 percent of the boilers, we believe this is 
current practice and readily achievable by most sources.\206\ These 
requirements have been in force for many years, and there is no basis 
for stating that they are unachievable (EPA is not aware of 
industrywide noncompliance with these provisions, the necessary premise 
of the comment). First, maintaining negative pressure is the option 
that most boilers elect to implement to demonstrate compliance with the 
RCRA fugitive emission control requirements. Second, negative pressure 
is readily achieved on an instantaneous basis in boilers through use of 
induced draft fans. Third, the requirements we are finalizing today for 
boilers are identical to the fugitive emission control requirements 
that hazardous waste incinerators, cement kilns, and lightweight 
aggregate kilns are currently complying with pursuant to the EEE 
interim standard regulations. See Sec.  63.1206(c)(5). Most of these 
sources maintain negative combustion chamber pressure through use of 
induced draft fans, providing further evidence that continuously 
maintaining combustion

[[Page 59492]]

zone pressure lower than ambient pressure is readily achievable by well 
designed and operated boilers.\207\
---------------------------------------------------------------------------

    \205\ The February 14, 2002 Final Amendments Rule clarifies that 
that a reasonable pressure monitoring frequency that could meet the 
intent of ``instantaneous'' would be once every second. See 67 FR at 
6974.
    \206\ Commenters did not provide data to the contrary.
    \207\ The commenter did not provide information that would lead 
us to conclude that these requirements are harder to implement for 
boilers than for incinerators, cement kilns, and lightweight 
aggregate kilns.
---------------------------------------------------------------------------

    We note that use of instantaneous pressure monitoring is not a 
requirement. A source can elect to implement any of the four compliance 
options to control combustion system leaks as well as request to use 
alternative monitoring approaches. See Sec. Sec.  63.1206(c)(5) and 
63.1209(g). The instantaneous pressure monitoring option offers sources 
a method that satisfies the intent of the rule that can be applied at 
numerous sources. The inclusion of this requirement in today's rule is 
thus an attempt to simplify the review process for both regulators and 
affected sources; the absence of prescriptive compliance options in 
this case may likely result in time-consuming site-specific 
negotiations that would prolong the review and approval of 
comprehensive performance test workplans.
    Comment: A commenter believes that requiring an instantaneous 
waste-feed cutoff when these pressure excursions occur is short-sighted 
and will result in greater HAP emissions. The commenter recommends EPA 
instead allow the use of reasonable pressure averaging periods in lieu 
of instantaneous pressure requirements.
    Response: As discussed in the February 14, 2002 Final Amendments 
Rule, automatic waste feed cutoffs are appropriate non-compliance 
deterrents, and are necessary whenever an operating limit is exceeded. 
See 67 FR at 6973. Pressure excursions that result in combustion system 
leaks (and subsequently lead to automatic waste feed cutoffs) should be 
prevented by maintaining negative pressure in the combustion zone. We 
agree that needless triggering of automatic waste feed cutoffs due to 
short term pressure fluctuations that do not result in combustion 
system leaks would provide less environmental protection, not more. 
Today's rule offers three alternative options that do not require the 
use of instantaneous pressure monitoring to control combustion system 
leaks. See Sec.  63.1206(c)(5). The use of averaging periods in these 
alternatives is not prohibited. Sources that elect to use an 
alternative compliance option must demonstrate that the alternative 
method is equivalent to maintaining combustion zone pressure lower than 
ambient pressure or, that the alternative approach prevents fugitive 
emissions.

E. Notification of Intent To Comply and Compliance Progress Report

1. Notice of Intent To Comply
    In the NPRM, we proposed to re-institute the Notification of Intent 
to Comply (NIC) because we felt that it offered many benefits in the 
early stages of MACT compliance. As discussed in the 1998 ``fast 
track'' rule (63 FR 33782) and in the proposal, the NIC serves several 
purposes: as a planning and communication tool in the early 
implementation stages, to compensate for lost public participation 
opportunities when using the RCRA streamlined permit modification 
procedure to make upgrades for MACT compliance, and as a means to share 
information and provide public participation opportunities that would 
be lost when new units are not required to comply with certain RCRA 
permit requirements and performance standards. Please refer to the 
proposal at 69 FR 21313-21316 for additional discussion of the 
regulatory history, purpose, and implementation of the NIC provisions.
    Overall, most commenters supported our decision to finalize NIC 
provisions. However, they also feel that the NIC should only be 
required for sources that have not completed a NIC previously (i.e., 
Phase 2 sources or Phase 1 sources that did not meet the previous NIC 
deadline) and for sources that need to make upgrades to comply with the 
final standards (i.e., either Phase 1 or Phase 2). They suggest that if 
sources do not need to make upgrades, then they should not be required 
to complete the NIC process, if they had done so previously. To require 
a second NIC would only add to the administrative burden and is not in 
line with Agency efforts to reduce reporting burdens. We agree that if 
Phase 1 sources do not need to make upgrades to comply with the 
Replacement Standards and if they completed the NIC process before, 
then it is not necessary to do so again.
    In addition to the comment discussed above, a few commenters 
proposed that for sources who must still comply with the NIC because 
they wish to make upgrades, that the NIC public notice be combined with 
the Title V re-opening or renewal public notice. They point out that 
sources with existing Title V permits will have their permits re-opened 
or renewed to incorporate the new applicable requirements (i.e., Phase 
1 Replacement or even Phase 2 Standards) shortly after the NIC public 
notice and meeting are to occur. Title V permit re-openings and 
renewals require: public notice, a minimum of 30 days for comment, and 
an opportunity to request a hearing.
    While we do agree that the Title V re-opening and renewal 
requirements provide adequate information to the public and an 
opportunity for the public to comment and request a hearing, we are 
concerned that the timing requirements for the NIC may not correspond 
with the timing requirements for title V permit reopenings, revisions, 
and renewals. The public review of the draft NIC and subsequent public 
meeting are scheduled to occur 9 and 10 months, respectively, after the 
rule's effective date. On the other hand, Title V permits for major 
sources that have a remaining permit term of greater than 3 years from 
the rule's promulgation date will need to be re-opened, but this re-
opening may not occur until 18 months beyond the promulgation date of 
the rule. Also, Title V permits that have a remaining permit term of 
less than 3 years from the rule's promulgation date will need to be 
renewed, but the timing of the renewal is contingent upon the 
individual permit term, not the timing requirements for public review 
of the draft NIC and public meeting. Thus, we do not believe there is 
ample opportunity to combine the requirements of the NIC and Title V 
process for the vast majority of sources.\208\ Also, those sources that 
need to make upgrades to comply with the final standards and that need 
to modify any applicable conditions in their RCRA permit will not be 
able to request the streamlined modification procedure (see 40 CFR 
270.42(j)) until they meet the NIC requirements. So the earlier they 
comply with the NIC requirements, the earlier they can begin upgrading 
their combustion units.
---------------------------------------------------------------------------

    \208\ We recognize that there may be instances when states can 
coordinate the Title V permit re-opening, revision, and renewal 
process with the NIC timeframe requirements. Where this is possible, 
we encourage states (or other permitting authorities) to coordinate 
the two processes. By coordinating the two, duplication with respect 
to material content and public participation would be eliminated for 
both sources and states.
---------------------------------------------------------------------------

    Another commenter suggested a change to the regulations at Sec.  
63.1210(c)(1) to account for sources that will cease burning hazardous 
waste prior to or on the compliance date. The regulations, as proposed, 
require sources to hold an informal public meeting to discuss 
anticipated activities described in the draft NIC even if they plan to 
cease burning hazardous waste. The commenter also suggested a similar 
change to Sec.  63.1210(b)(2) that requires the draft NIC be made 
available for public review no later than 30 days

[[Page 59493]]

prior to the public meeting. We agree with the commenter that it does 
not make sense to require sources that intend to cease burning 
hazardous waste to submit a NIC that discusses anticipated activities 
that will allow them to achieve compliance with the standards. We also 
agree that it is not necessary for those sources to hold an informal 
public meeting, since there are no MACT compliance activities to 
discuss. However, we believe that the public should be provided notice 
of the draft NIC so that they are aware of the source's intentions to 
cease burning and the steps (and key dates) the source will undertake 
to stop hazardous waste combustion activities.
    With regard to Phase 2 sources, we had proposed that all Phase 2 
sources comply with the same NIC requirements as the Phase 1 sources. 
Commenters did not express opinions in favor or against the NIC for 
Phase 2 sources. We believe that the NIC is beneficial in several 
respects. As mentioned previously, it serves as a planning and 
communication tool in the early implementation stages, it compensates 
for lost public participation opportunities when using the RCRA 
streamlined permit modification procedure to make upgrades for MACT 
compliance, and it is a tool to share information and provide public 
participation opportunities that would be lost when new units are not 
required to comply with certain RCRA permit requirements and 
performance standards. Ultimately, it creates more public confidence in 
the permitting process and so promotes a more stable regulatory 
environment.
    For today's rule, we are finalizing our decision to re-institute 
the NIC provisions for Phase 1 and Phase 2 sources. We are including a 
few minor changes and clarifications to improve the proposed regulatory 
language based on commenters' suggestions. Section 63.1210(b) is 
revised so that Phase 1 sources that previously complied with the NIC 
requirements, and that do not need to make upgrades to comply with the 
Replacement Standards, are not required to comply with the NIC again. 
Sections 63.1210(b)(1)(iv) and (b)(2) have been revised and (c)(5) has 
been added so that sources that intend to cease burning hazardous waste 
prior to or on the compliance date are only required to prepare a 
(draft) NIC, make a draft of the NIC available for public review no 
later than 9 months after the effective date of the rule, and submit a 
final NIC to the Administrator no later than one year following the 
effective date of the rule. Last, we have revised language in Sec.  
63.1210(b) based upon a commenter's concerns that the term you ``will'' 
implies that sources are required meet their ``estimated'' dates for 
achieving key activities. We have removed ``will'' and replaced it with 
``anticipate'' to more accurately represent the objective of the NIC, 
which is for sources to communicate their plans for complying with the 
standards in two years.
2. Compliance Progress Report
    In the proposal, we explained why we thought a compliance progress 
report would be beneficial. In short, we believed it would help 
regulatory agencies determine whether Phase 1 and Phase 2 sources were 
making sufficient headway in their efforts to meet the compliance date. 
The progress report would be due to the regulatory agency at the midway 
point of the 3 year compliance period and would serve to update the 
information the source provided in its NIC. However, because we do not 
have any experience to draw upon regarding the value of the progress 
report, we requested comment on whether or not it should be required.
    In response to our request for comment, all commenters were opposed 
to the progress report. They cited several reasons, with the most 
consistent one being that the progress report serves no useful purpose 
and imposes unnecessary additional burdens on sources. As we discussed 
above, sources and regulatory agencies will be focusing on the NIC as 
well as initial Title V applications, re-openings, revisions, and 
renewals during this three year compliance period. We agree with the 
commenter who noted that there is already significant interaction 
between sources and regulatory authorities during this period. 
Furthermore, we learned through implementation of the Interim Standards 
that some regulatory agencies found it difficult to manage the notices, 
applications, requests, and test plans that were due prior to the 
compliance date. Therefore, we have decided not to finalize any 
compliance progress report requirements for today's rule.

F. Startup, Shutdown, and Malfunction Plan

    Comment: One commenter states that an exceedance of a standard or 
operating requirement during a malfunction should be a violation not 
only because source owners and operators need an incentive to minimize 
exceedances caused by malfunctions, but also because an exemption for 
malfunction periods would violate the plain language of the CAA. The 
commenter notes that an emission standard is defined by 42 U.S.C. Sec.  
7602(k) as a standard that ``limits the quantity, rate, or 
concentration of emissions of air pollutants on a continuous basis, 
including any requirement relating to the operation of maintenance of a 
source to assure continuous emission reduction, and any design, 
equipment, work practice or operational standard * * *.'' The commenter 
concludes that a standard that contains a malfunction exemption does 
not apply ``on a continuous basis'' as required by the statute. 
Likewise, the commenter concludes that an exemption for startup and 
shutdown periods would also violate this unambiguous statutory 
language.
    The commenter also notes that, although some courts have held that 
a technology-based standard must provide some kind of an exemption for 
unavoidable technology failures, the rationale for such an exemption is 
that the underlying standard is based on the performance of a 
particular control technology that cannot be expected to function 
properly all of the time. The commenter believes that neither the 
rationale nor the exemption apply to section 112(d) standards, which 
are not based on the performance of any particular technology but 
instead must reflect the ``maximum degree of reduction'' that can be 
achieved, irrespective of the measures used by a source to achieve that 
reduction. CAA Sec.  112(d)(2).
    The commenter states that, even assuming for the sake of argument 
that EPA has authority to depart from the statutory language and carve 
out a startup, shutdown, and malfunction exemption, any such exemption 
must be narrowly drafted to apply only where a source demonstrates that 
a violation was unavoidable. See, e.g., Marathon Oil, 564 F.2d at 1272-
73. As EPA recognizes, emission exceedances that occur during SSM 
events are frequently avoidable. See 69 FR at 21339/3 (noting that 
``proper operation and maintenance of equipment'' helps avoid 
exceedances during startup, shutdown, and malfunction events), 69 FR at 
21339/2 (describing the industry view that ``some'' exceedances that 
occur due to malfunctions are unavoidable). Thus, the commenter 
concludes that, even if a Marathon Oil-type exemption applies to a 
Sec.  112(d) standard, it would be unlawful and arbitrary for EPA to 
exempt sources from liability for all emission exceedances occurring 
during startup, shutdown, and malfunction events. Rather, such an 
exemption could only apply where a source demonstrates that a given 
exceedance was unavoidable.

[[Page 59494]]

    Many other commenters state that it would be illegal to require 
compliance with the emission standards and operating requirements 
during startup, shutdown, and malfunction events. The commenters note 
that EPA and the courts have long recognized that technology fails at 
times, despite a source's best efforts to maintain compliance. For this 
reason, the courts have recognized that technology-based standards such 
as EPA's Sec.  112(d)(2) MACT standards must account for such 
unavoidable technology failures if the standards are to be truly 
``achievable.'' Thus, the standards must excuse noncompliance with the 
actual emission standards during startup, shutdown, and malfunction 
events.
    These commenters also note that EPA took the position in the 
September 1999 final MACT rule for hazardous waste combustors that 
exceedance of an operating requirement during startup, shutdown, or 
malfunction events was a violation if hazardous waste remained in the 
combustion chamber. The commenters note that industry groups challenged 
the rule, and while the D.C. Circuit did not reach this issue because 
it vacated the emission standards, it pointed out that ``industry 
petitioners may be correct that EPA should have exempted HWCs from 
regulatory limits during periods of startup, shutdown, and malfunction, 
permitting sources to return to compliance by following the steps of a 
startup, shutdown, and malfunction plan filed with the Agency.'' CKRC 
v. EPA, 255 F.3d 855, 872 (2001). Commenters conclude that, after 
reading this language, EPA officials wisely decided that hazardous 
waste combustors should not be required to meet the MACT emission 
standards and operating limits during startup, shutdown, and 
malfunction events.
    Response: We agree with commenters who state that sources must be 
exempt from technology-based emission standards and operating limits 
during startup, shutdown, and malfunction events. Technology is 
imperfect and can malfunction for reasons that are not reasonably 
preventable. The regulations must provide relief for such situations. 
We believe that existing case law supports this position. See, e.g., 
Chemical Mfr's Ass'n v. EPA, 870 F. 2d at 228-230 (daily maximum 
limitations established at 99th percentile reasonable because rules 
also provide for upset defense for unavoidable exceedances); Marathon 
Oil v. EPA, 541 F. 2d at 1272-73 (acknowledged by commenter). As 
commenters noted, the D.C. Circuit also intimated in CKRC that some 
type of exception from compliance with standards during startup, 
shutdown and malfunction periods was required.
    We do not agree with the commenter who contends that the Sec.  
112(d) MACT standards are not technology-based standards because they 
are not based on the performance of any particular technology but 
instead must reflect the ``maximum degree of reduction'' that can be 
achieved, irrespective of the measures used by a source to achieve that 
reduction. On the contrary, the standards must reflect the average 
performance of the best performing sources, which performance is 
achieved using technical controls--air pollution control devices, and 
for some pollutants, hazardous waste feedrate control. Those controls 
can fail for reasons that are not reasonably preventable. We note 
further that the situation was the same in the Clean Water Act cases 
which the commenter seeks to distinguish. Like section 112(d) 
standards, Clean Water Act standards are technology-based (reflecting 
Best Practicable Technology or Best Available Technology, see CWA 
sections 304 (b) and 301 (b)) and do not require use of any particular 
type of technology. See also Mossville, 370 F. 3d at 1242 (EPA must 
account for foreseeable variability in establishing MACT floor 
standards).
    We agree with the commenter who states that any exemption from the 
emission standards and operating requirements during malfunctions must 
apply only where a source demonstrates that a violation was 
unavoidable. We note that the term malfunction is defined in Sec.  63.2 
as ``any 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 which causes, or has the 
potential to cause, the emission limitations in an applicable standard 
to be exceeded. Failures that are caused in part by poor maintenance or 
careless operation are not malfunctions.'' We believe this definition 
largely addresses the commenter's concern.
    We acknowledge, however, that emissions can increase during 
malfunctions and potentially exceed the standards and agree that 
exceedances must be minimized. Accordingly, the final rule (and the 
current rule for incinerators, cement kilns, and lightweight aggregate 
kilns) requires that sources maintain compliance with the automatic 
hazardous waste feed cutoff system during malfunctions and notify the 
permitting authority if they have 10 or more exceedances of an emission 
standard or operating limit during a 6-month block period when 
hazardous waste is in the combustion chamber. See Sec.  
63.1206(c)(2)(v). This will alert the permitting authority that the 
source's operation and maintenance plan may not be adequate to maintain 
compliance with the emission standards and that the authority may need 
to direct the source to revise the plan under Sec.  63.6(e)(3)(vi). 
Finally, we note that sources must report all excess emissions 
semiannually under Sec.  63.10(e)(3) if an emission standard or 
operating limit is exceeded, including during malfunctions.
    Comment: One commenter states that any exemption for emission 
exceedances during startup, shutdown, or malfunction events would 
violate the RCRA mandate for standards necessary ``to protect human 
health and the environment.'' 42 U.S.C. 6924(a). The commenter reasons 
that, because EPA's RCRA standards are health-based rather than 
technology-based, no unavoidability defense is available. Given that 
EPA concludes that the hazardous waste combustor MACT rule satisfies 
both its CAA and RCRA mandates, the emission standards and operating 
requirements cannot be waived during startup, shutdown, and malfunction 
events.
    Response: We agree that the RCRA mandate to ensure protection of 
human health and the environment applies at all times, including during 
startup, shutdown, and malfunction events. Accordingly, the existing 
MACT requirements for incinerators, cement kilns, and lightweight 
aggregate kilns give sources the option of continuing to comply with 
RCRA permit requirements to control emission during these events, or to 
comply with special MACT requirements that are designed to be proactive 
and reactive and intended to be equivalent to the incentive to minimize 
emissions during these events provided by the RCRA requirements. See 
existing Sec.  63.1206(c)(2)(ii). The special MACT requirements require 
sources to include proactive measures in the startup, shutdown, and 
malfunction plan to minimize the frequency and severity of malfunctions 
and to submit the startup, shutdown, and malfunction plan to the 
permitting authority for review and approval. We proposed to require 
boilers and hydrochloric acid production furnaces to comply with those 
same provisions providing for equivalence between the two sets of 
requirements, and promulgate those provisions today.
    Comment: One commenter states that the rule should clarify the 
definitions of startup, shutdown, and malfunctions to preclude sources 
from improperly

[[Page 59495]]

classifying as unavoidable exceedances those exceedances that could 
have been avoided had the source implemented an appropriate operation 
and maintenance plan. Many other commenters state that the current 
definitions in Sec.  63.2 clearly define these terms.
    Response: We believe the definitions of startup, shutdown, and 
malfunction are clearly defined in Sec.  63.2, and combined with the 
startup, shutdown, and malfunction plan requirements, will preclude 
sources from improperly classifying as malfunctions events that could 
have been reasonably prevented by following appropriate procedures in 
the operation and maintenance plan. As discussed above, the definition 
of malfunction clearly states that failures that are caused in part by 
poor maintenance or careless operation are not malfunctions.
    Comment: One commenter states that all stack bypasses, automatic 
waste feed cutoffs, and excursions from the operating parameter limits 
should be considered malfunctions.
    Response: All failures resulting in stack bypasses, automatic waste 
feed cutoff, and excursions from the operating parameter limits are not 
malfunctions. As discussed above, failures caused in part by poor 
maintenance or careless operation are not malfunctions.
    Comment: One commenter states that the rule should require sources 
to expand the startup, shutdown, and malfunction plan to address 
specific proactive measures that the source has considered and is 
taking to minimize the frequency and severity of malfunctions. Many 
other commenters believe that it is not necessary to expand the scope 
of the startup, shutdown, and malfunction plan beyond that required 
under Sec.  63.6(e)(3) for other MACT source categories.
    Response: We do not believe that it is necessary to expand the 
scope of the startup, shutdown, and malfunction plan generically for 
all hazardous waste combustors to address specific proactive measures 
that the source has considered and is taking to minimize the frequency 
and severity of malfunctions. Imposing additional requirements in 
particular situations is appropriate, however. For example, as 
discussed above, this expanded plan is required for sources that elect 
to meet the RCRA mandate using provisions of the startup, shutdown, and 
malfunction plan. See Sec.  63.1206(c)(2)(ii). In addition, the plan 
with expanded scope may be appropriate for sources that have 
demonstrated an inability to minimize malfunctions. Consequently, the 
permitting authority should consider expanding the scope of the 
startup, shutdown, and malfunction plan on a site-specific basis under 
authority of Sec.  63.6(e)(3)(vii) if the source has excessive 
exceedances during malfunctions. See Sec.  63.1206(c)(2)(v)(A)(3) 
defining excessive exceedances during malfunctions and requiring 
reporting of the exceedances in the excess emissions report required 
under Sec.  63.10(e)(3).
    Comment: Two commenters state that all startup, shutdown, and 
malfunction plans should be submitted for review and approval by the 
delegated authority and made available for a 60-day public review 
period. Review and approval of the plans is needed in light of EPA's 
acknowledgment that most excess emissions would occur during startup, 
shutdown, and malfunctions. One of these commenters also believes that 
the regulations should provide for the public review period to be 
extended as necessary to accommodate a thorough public review. The 
reviewing authority should be required to provide a written response to 
public comments explaining any decision to reject a public comment 
suggesting ways for a facility to limit emissions during startup, 
shutdown, and malfunction events.
    Many other commenters have concerns with requiring review and 
approval of startup, shutdown, and malfunction plans, except as 
required under Sec.  63.1206(c)(2)(ii) for sources that elect to meet 
the RCRA mandate using provisions of the startup, shutdown, and 
malfunction plan as discussed above.
    Response: Commenters express the same views here that they 
expressed under the rulemaking the Agency recently completed to revise 
the startup, shutdown, and malfunction plan requirements of the General 
Provisions applicable to all MACT source categories. See 68 FR at 
32589-93 (May 30, 2003).
    EPA concluded in that final rule that the Administrator may at any 
time request in writing that the owner or operator submit a copy of any 
startup, shutdown, and malfunction plan (or a portion thereof). Upon 
receipt of such a request, the owner or operator must promptly submit a 
copy of the requested plan (or a portion thereof) to the Administrator. 
In addition, the Administrator must request that the owner or operator 
submit a particular startup, shutdown, or malfunction plan (or a 
portion thereof) whenever a member of the public submits a specific and 
reasonable request to examine or to receive a copy of that plan or 
portion of a plan.
    These provisions to provide the Administrator and the public with 
access to startup, shutdown, and malfunction plans, coupled with the 
provisions of Sec.  63.6(e)(3)(vii) under which the Administrator must 
require the source to make changes to a deficient plan, should ensure 
that startup, shutdown, and malfunction plans are complete and 
accurate. We note that under Sec.  63.6(e)(3)(vii) the Administrator 
must require the source to revise the plan if the plan: (1) does not 
address a startup, shutdown, or malfunction event that has occurred; 
(2) fails to operate the source (including associated air pollution 
control and monitoring equipment) during a startup, shutdown, or 
malfunction event in a manner consistent with the general duty to 
minimize emissions; (3) does not provide adequate procedures for 
correcting malfunctioning process and/or air pollution control and 
monitoring equipment as quickly as practicable; or (4) includes an 
event that does not meet the definition of startup, shutdown, or 
malfunction listed in Sec.  63.2.
    The commenter advocating that all hazardous waste combustors should 
be required to submit their startup, shutdown, and malfunction plans 
for review and approval did not explain why the concerns the Agency 
expressed in the General Provisions rulemaking (see 68 FR at 32589-93) 
are not valid for hazardous waste combustors. Accordingly, we do not 
believe it is appropriate to deviate from the General Provisions to 
require that all hazardous waste combustors submit their startup, 
shutdown, and malfunction plans for review.

G. Public Notice of Test Plans

1. What Are the Revised Public Notice Requirements for Test Plans?
    Prior to the proposal, it was brought to our attention that the 
Agency did not provide any direction in the 1999 final rule regarding 
how and when sources should notify the public, what the notification 
should include, or where and for how long performance test plans should 
be made available. Consequently, we proposed to add clarifying language 
to the Sec.  63.1207(e)(2) public notification requirement for approved 
performance test and CMS performance evaluation test plans because we 
believe that providing opportunities for timely and adequate public 
notice is necessary to fully inform nearby communities of a source's 
plans to initiate important waste management activities. The proposed 
clarifications are based upon the RCRA Expanded Public Participation 
Rule (60 FR 63417, December 11, 1995) requirements for

[[Page 59496]]

public notification of an impending trial burn test. As a result, we 
did not feel that the clarifications imposed any new or additional 
requirements upon sources that will conduct a MACT comprehensive 
performance test or confirmatory performance test.
    Commenters generally supported the clarifications to the public 
notice.\209\ However, they suggested a change to the proposed 
requirement to provide notice of test plan approval no later than 60 
days prior to conducting the test. The basis for suggesting a change is 
that many sources had not received approval of their test plans 60 days 
prior to the deadline for initiating their test under the Interim 
Standards. Moreover, several sources did not receive approval until 
well after the deadline for initiating the test. The problem created 
for these sources is that the required 60 day notification of the 
approved test plan effectively determines when the source will be able 
to begin its test. In other words, its test would need to be postponed 
until the approved test plan had been noticed for 60 days. Thus, 
commenters provided several possible alternatives.
---------------------------------------------------------------------------

    \209\ See 69 FR 21347-21349.
---------------------------------------------------------------------------

    One alternative that would avoid causing delays to testing is to 
require the public notice when the source submits its test plan. 
Although this fulfills the notification requirement, this alternative 
has a shortfall: The notice would occur at least one year (barring any 
extensions) in advance of the test and given this long period of time, 
the test plan is likely to be modified prior to approval. A second 
alternative is to provide notice of the test plan 60 days before the 
test as before, but regardless of approval status. This alternative is 
improved over the first, but still faces the same problem of 
potentially not offering the public an opportunity to view a final 
approved plan. A third alternative is to issue notice of the test plan 
as soon as it is approved. With this alternative, the public will have 
the most up-to-date information; however, it may not be until a few 
days prior to commencement of the test. Ideally, the second and third 
alternatives could be combined to provide the best possible chance of 
providing the public with an approved test plan in a reasonable period 
of time prior to the test. On the other hand, that would potentially 
require the facility to issue two notices if the test plan is not 
approved 60 days prior to the test. We do not believe this would be 
reasonable given that sources will be focused on activities associated 
with the impending test.
    In consideration of practicality, we believe that the second 
alternative provides an adequate solution. As we mentioned, the 
drawback is that the public may not have the opportunity to view an 
approved test plan. However, we believe it is more important that the 
public be aware of a source's plans (i.e., how and when) for conducting 
the performance test.\210\ This way, if they have questions, there will 
be 60 days in which they may contact the regulatory authority or the 
source before the test is scheduled to begin. This alternative will 
also eliminate the conflict associated with the confirmatory 
performance test. The regulations at Sec.  63.1207(e)(1)(ii) specify 
that a source must submit to the regulatory authority its notice of 
intent to conduct a confirmatory performance test and the applicable 
test plans at least 60 calendar days prior to the date the test is to 
begin. Since we are no longer requiring that the test plans be approved 
before issuing public notice, sources would then provide notice of 
their confirmatory performance test plan to the public at the same time 
they submit their notice of intent and test plans to the regulatory 
authority. Therefore, we are requiring that sources issue the public 
notice of test plans 60 days in advance of commencing the performance 
test, whether their test plans have been approved or not. The 
regulations at Sec.  63.1207(e)(2) have been revised accordingly.
---------------------------------------------------------------------------

    \210\ We expect that some source's test plans may be modified 
after notice is issued and prior to approval or commencement of 
their test. However, even under the previous regulations, test plans 
could be modified after they had been approved and public noticed. 
It is often a necessary consequence as sources continue to prepare 
the combustion unit for the test.
---------------------------------------------------------------------------

    One last concern related to the public notice of approved test 
plans involves sources that choose to conduct a performance test 
without an approved test plan (e.g., both time extensions provided by 
Sec. Sec.  63.7(h) and 63.1207(e)(3) have expired or due to other 
circumstances, the source has elected to begin the test without 
approval). Because we did not believe any sources would choose or need 
to do so, we did not propose any guidance or regulations specific to 
issuing notice to the public of their test plans. Nevertheless, a few 
commenters raised this possibility indirectly in their discussion of 
the problematic 60 day notice of approved test plan requirement. The 
revised proposal addresses this concern by no longer requiring that 
test plans be approved before issuing public notice. Thus, sources that 
choose to begin their test without an approved plan will have complied 
with the requirement to issue public notice. Irrespective of the public 
notice requirements for noticing test plans, we expect that sources 
will notify their regulatory authority of their decision to proceed 
with their test in the absence of plan approval.
2. What Are the Revised Public Notice Requirements for the Petition To 
Waive a Performance Test?
    In the Final Amendments Rule (67 FR 6968, February 14, 2002), the 
Agency did not provide direction regarding how, when, where, and what 
should be included in the public notice for a petition for time 
extension if the Administrator fails to approve or deny test 
plans.\211\ In the proposal, we believed it important to provide 
clarification regarding when the notice must be issued and what it 
should contain. Thus, we proposed to revise paragraph Sec.  
63.1207(e)(3)(iv).
---------------------------------------------------------------------------

    \211\ Sections 63.1207(e)(2) and (e)(3) each require public 
notice, but neither had provided any direction on how, when, where, 
and what should be included in their respective notices until 
today's final rule.
---------------------------------------------------------------------------

    We received only one comment in response to the proposed 
requirements. The commenter did not express any concern over the 
requirements themselves, but rather suggested a change to terminology 
used. The commenter feels that the terms ``to waive a performance 
test'' or ``waiver'' as used in Sec.  63.1207(e)(3)(iv) could be 
confusing to readers when we are actually referring to a time extension 
for commencing the test. Although we agree the terminology could be 
confusing, 40 CFR 63.1207(e)(3) clearly uses the term ``waiver'' in the 
context of an extension of time to conduct the performance test at a 
later date, implying that the deadline can be waived in this specific 
situation. The use of the term waiver is derived from the General 
Provisions requirements for requesting a waiver of performance tests 
(Sec.  63.7(h)). Thus, Sec.  63.7(h)(3) provides the basis by which 
sources may petition, in the form of a waiver, for a time extension 
under Sec.  63.1207(e)(3). In consideration of the above and that the 
existing regulations of Sec.  63.1207(e)(3)(i)-(iii) consistently use 
the term waiver, we do not feel that a change to Sec.  
63.1207(e)(3)(iv) is warranted.

H. Using Method 23 Instead of Method 0023A

    Comment. Most commenters support our proposal to allow the use of 
Method 23 instead of Method 0023A if a source includes this request in 
the comprehensive test plan to the permitting authority. Some 
commenters believe that Method 23 should be

[[Page 59497]]

allowed in all cases without prior approval or on a source category 
basis.
    Response. We proposed to allow sources to use Method 23 for dioxin 
and furan testing instead of SW-846 Method 0023A in situations where 
the enhanced procedures found in Method 0023A would not increase 
measurement accuracy. We proposed this change in the July 3, 2001, 
proposed rule, and again in the April 20, 2004, proposal. See 66 FR at 
35137 and 69 FR at 21342.
    The final rule promulgates this change as proposed. See Sec.  
63.1208(b)(1)(i). You may use Method 23 in lieu of Method 0023A after 
justifying use of Method 23 as part of your performance test plan that 
must be reviewed and approved the delegated permitting authority. You 
may be approved to use Method 23 considering factors including whether 
previous Method 0023A analyses document that dioxin/furan are not 
detected, are detected at low levels in the front half of Method 0023A, 
or are detected at levels well below the emission standard, and the 
design and operation of the combustor has not changed in a manner that 
could increase dioxin/furan emissions. We note that coal-fired boilers 
and combustors equipped with activated carbon injection systems may not 
be able to support use of Method 23, however, because these sources' 
stack gas is likely to contain carbonaceous particulate. Thus, these 
sources are likely to benefit the most from using Method 0023A.
    The final rule does not automatically allow use of Method 23 for 
particular source categories because we cannot assess whether all 
sources in a category meet the conditions for use of Method 23--
generally that quality assurance may not be improved--such as those 
listed above. These determinations can only be made on a site specific 
basis by the permitting authority most familiar with the particular 
source.
    Comment: Commenters do not believe that an additional petition 
process (i.e., under Sec.  63.1209(g)(1)) is necessary before allowing 
use of Method 23. Instead, EPA should require that the use of Method 23 
should be submitted with the test plan to the regulatory agency for 
approval.
    Response: We agree that a separate petition is unnecessary. Sources 
should include a justification to use Method 23 in the performance test 
plan that is submitted for review and approval. This will allow the 
permitting authority to determine whether use of Method 23 is 
appropriate for the source.
    Comment: Two commenters state that ``the justification of the use 
of Method 23 will not be by the existing system of a petition to EPA, 
but will be included as a part of the performance test plan that is 
submitted to the delegated regulatory authority for review and 
approval. This means that the expertise, training, and decision-making 
will not be consistent across the country. This is especially a problem 
because of the severe resource, training and staff reductions among the 
delegated regulatory authorities across the country and from region to 
region. The decision to allow or disallow use of Method 23 should come 
specifically, for each case, from EPA consideration of the submitted 
justification, based on the knowledge and expertise of trained and 
experienced EPA staff. This is important for uniformly applying the 
testing requirements all across the country.''
    Response: We disagree, and we believe the responses to comments in 
today's rule make clear when Method 23 is an acceptable substitute for 
Method 0023A. If the source has carbon in the flue gas, as is the case 
with coal-fired boilers, boilers with carbon injection, and other 
sources likely to have a substantial amount of carbonaceous particulate 
matter in the flue gas, Method 0023A will generally be preferable 
because it includes procedures to account for dioxin and furan bound to 
carbonaceous particulate matter found in the probe and filter. In other 
situations, Method 23 will generally give the same results at a lower 
cost.

I. Extrapolating Feedrate Limits for Compliance With the Liquid Fuel 
Boiler Mercury and Semivolatile Metal Standards

    Comment: One commenter questions whether allowing sources to 
extrapolate metal feedrates downward from the levels achieved during 
the comprehensive performance test to establish a metal feedrate limit 
will ensure compliance with the emission standards.
    Response: The mercury and semivolatile metals standards for liquid 
fuel boilers are annual average emission limits where compliance is 
established by a rolling average mercury feedrate limit with an 
averaging period not to exceed an annual rolling average (updated 
hourly).\212\ We use this approach because the emissions data used to 
establish the standards are more representative of normal emissions 
than compliance test emissions.\213\
---------------------------------------------------------------------------

    \212\ If you select an averaging period for the feedrate limit 
that is greater than a 12-hour rolling average, you must calculate 
the initial rolling average as though you had selected a 12-hour 
rolling average, as provided by Sec.  63.1209 (b)(5)(i). This is 
reasonable because allowing a longer period of time before 
calculating the initial rolling average would not effectively ensure 
compliance with the feedrate limit. You must calculate rolling 
averages thereafter as the average of the available one-minute 
values until enough one-minute values are available to calculate the 
rolling average period you select. We note that this is an approach 
allowed for calculating rolling averages under different modes of 
operation at Sec.  63.1209(q)(2)(ii). At that time and thereafter, 
you update the rolling average feedrate each hour with a 60-minute 
average feedrate.
    \213\ See USEPA, ``Technical Support Document for HWC MACT 
Standards, Volume III: Selection of HWC MACT Standards,'' September 
2005, Section 13.
---------------------------------------------------------------------------

    As we explained at proposal, to ensure compliance with the mercury 
and semivolatile metal emission standards for liquid fuel boilers, you 
must document during the comprehensive performance test a system 
removal efficiency for the metals and back-calculate from the emission 
standard a maximum metal feedrate limit that must not be exceeded on an 
(not to exceed) annual rolling average. See 69 FR at 21311-12. If your 
source is not equipped with an emission control system (such as 
activated carbon to control mercury) for the metals in question, 
however, you must assume zero system removal efficiency. This is 
because, although a source that is not equipped with an emission 
control system may be able to document a positive system removal 
efficiency in a single test, that removal efficiency is not likely to 
be reproducible. Rather, it is likely to be an artifact of the 
calculation of emissions and feeds rather than a removal efficiency 
that can reliably be repeated.
    To ensure that you can calculate a valid, reproducible system 
removal efficiency for sources equipped with a control system that 
effectively controls the metal in question, you may need to spike 
metals in the feed during the comprehensive performance test at levels 
that may result in emissions that are higher than the standard. This is 
appropriate because compliance with an emission standard derived from 
normal emissions data is based on compliance with an (not to exceed) 
annual average feedrate limit calculated as prescribed here, rather 
than compliance with the emission standard during the comprehensive 
performance test.\214\
---------------------------------------------------------------------------

    \214\ The emission standard accounts for long-term variability 
by incorporating an (not to exceed) annual averaging period that is 
implemented by an (not to exceed) annual average chlorine feedrate 
limit. Thus, because the emission level achieved during the 
performance test relates to daily (or hourly) variability, an 
exceedance of the emission standard during the test is not a 
violation.
---------------------------------------------------------------------------

    The commenter is concerned that downward extrapolation from the 
levels achieved during the comprehensive performance test to establish 
a metal feedrate limit may not ensure

[[Page 59498]]

compliance with the standard because system removal efficiency may be 
lower at lower feedrates.
    This is a valid concern, and we have investigated it since 
proposal. We conclude that downward extrapolation of feedrates for the 
purpose of complying with the mercury and semivolatile metals emission 
standards for liquid fuel boilers will ensure compliance with the 
emission standards under the conditions discussed below.
    We investigated the theoretical relationship between stack gas 
emissions and feedrate considering vapor phase metal equilibrium, the 
chlorine, mercury, and semivolatile metal feedrates for liquid fuel 
boilers in our data base, and the mercury and semivolatile emission 
standards for liquid fuel boilers.\215\ We considered sources equipped 
with dry particulate matter controls and sources equipped with wet 
particulate matter controls.
---------------------------------------------------------------------------

    \215\ USEPA, ``Technical Support Document for HWC MACT 
Standards, Volume IV: Compliance with the HWC MACT Standards,'' 
September 2005, Section 2.5 and Appendix B.
---------------------------------------------------------------------------

    Sources Equipped with Dry Controls. For sources equipped with dry 
controls other than activated carbon, mercury is not controlled. Thus, 
you must assume zero system removal efficiency. Consequently, if you 
are in the low Btu subcategory and comply with the mercury standard 
expressed as a mass concentration ([mu]g/dscm), the mercury feedrate 
limit expressed as an MTEC (maximum theoretical emission concentration, 
[mu]g/dscm) is equivalent to the emission standard.\216\ If you are in 
the high Btu subcategory and comply with the mercury standard expressed 
as a hazardous waste thermal emission concentration (lb/MM Btu), the 
mercury feedrate limit expressed as a hazardous waste thermal feed 
concentration (lb/MM Btu) is also equivalent to the emission standard.
---------------------------------------------------------------------------

    \216\ Note, however, that you convert the MTEC ([mu]g/dscm) to a 
mass feedrate (lb/hr) by considering the average gas flowrate of the 
test run averages during the comprehensive performance test to 
simply implementation and compliance.
---------------------------------------------------------------------------

    For semivolatile metals, the theoretical relationship between 
emissions and feedrate indicates that downward extrapolation introduces 
only a trivial error'0.17% at an emission rate 100 times the standard 
irrespective of the level of chlorine present. Id. Nonetheless, to 
ensure the error is minimal and to be practicable, you should limit 
semivolatile emissions during the comprehensive performance test to 
five times the emission standard.
    Sources Equipped with Wet Scrubbers. For sources equipped with wet 
scrubbers, we conclude that the approach we use for semivolatile metals 
for dry scrubbers will also be appropriate to extrapolate a 
semivolatile metal feedrate limit for wet scrubbers. To ensure that 
downward extrapolation of the feedrate limit is conservative and to be 
practicable, you should limit semivolatile metal emissions during the 
comprehensive performance test to five times the emission standard.
    For mercury, ensuring control with wet systems is more complicated 
because the level of chlorine present affects the formation of mercuric 
chloride which is soluble in water and easily controlled by wet 
scrubbers. Elemental mercury has very low solubility in scrubber water 
and is not controlled. The worst-case situation for conversion of 
elemental mercury to soluble mercuric chloride would be when the 
chlorine MTEC is lowest and the mercury MTEC is highest. We conclude 
that downward extrapolation of mercury feedrates is conservative for 
feedstreams that contain virtually no chlorine, e.g., below an MTEC of 
100 [mu]g/dscm. In addition, we conclude that downward extrapolation is 
appropriate \217\ for boilers feeding chlorinated feedstreams provided 
that during the performance test: (1) Scrubber blowdown has been 
minimized and the scrubber water has reached steady-state levels of 
mercury prior to the test (e.g., by spiking the scrubber water); (2) 
scrubber water pH is minimized (i.e., you establish a minimum pH 
operating limit based on the performance test as though you were 
establishing a compliance parameter for the total chlorine emission 
standard); and (3) temperature of the scrubber water is maximized 
(i.e., you establish a maximum scrubber water temperature limit).
---------------------------------------------------------------------------

    \217\ Mercury SRE is constant as the mercury feedrate decreases.
---------------------------------------------------------------------------

J. Temporary Compliance With Alternative, Otherwise Applicable MACT 
Standards

    Comment: One commenter requests clarification on the requirements 
applicable to a source that switches to an alternative mode of 
operation when hazardous waste is no longer in the combustion chamber 
under the provisions of Sec.  63.1206(b)(1)(ii). The commenter suggests 
that Sec.  63.1206(b)(1)(ii) can imply that the complete compliance 
strategy needs to be switched over to the alternative section 112 or 
129 requirements, even though compliance with the Subpart EEE 
requirements for monitoring, notification, reporting, and recordkeeping 
remains environmentally protective under Subpart EEE. For example, the 
commenter notes that Sec.  63.1206(b)(1)(ii) could be incorrectly 
interpreted to require a source to comply with illogical requirements 
when the source temporarily switches to alternative, otherwise 
applicable standards, including standards testing and opacity 
monitoring under the alternative section 112 or 129 requirements. The 
commenter states that this interpretation makes little sense because a 
source that temporarily changes its mode of operation will continue to 
do testing under Subpart EEE, Part 63, or, in the case of opacity, the 
alternative section 112 requirements for cement kilns would necessarily 
require duplicate systems and compliance with redundant limits because 
a source may already be using a bag leak detection system or a 
particulate matter detection system. The commenter suggests only 
requiring sources to comply with the otherwise applicable emission 
standards under the alternative section 112 or 129 requirements while 
still operating under the various associated compliance requirements of 
Subpart EEE, part 63.
    Response: The commenter requests clarification of Sec.  
63.1206(b)(1)(ii), which states that if a source is not feeding 
hazardous waste to the combustor and the hazardous waste residence time 
has expired (i.e., the hazardous waste feed to the combustor has been 
cut off for a period of time not less than the hazardous waste 
residence time), then the source may elect to comply temporarily with 
alternative, otherwise applicable standards promulgated under the 
authority of sections 112 and 129 of the Clean Air Act.\218\ As we have 
explained in previous notices,\219\ sources that elect to invoke Sec.  
63.1206(b)(1)(ii) to become temporarily exempt from the emission 
standards and operating requirements of Subpart EEE, Part 63, remain an 
affected source under Subpart EEE (and only Subpart EEE) until the 
source is no longer an affected source by meeting the requirements 
specified in Table 1 of Sec.  63.1200. Of course, a source can elect 
not to use the alternative requirements for compliance during periods 
when

[[Page 59499]]

they are not feeding hazardous waste, but, if so, the source must 
comply with all of the operating and monitoring requirements and 
emission standards of Subpart EEE at all times.\220\ To implement Sec.  
63.1206(b)(1)(ii) a source defines the period of compliance with the 
otherwise applicable sections 112 and 129 requirements as an 
alternative mode of operation under Sec.  63.1209(q). In order to be 
exempt from the emission standards and operating requirements of 
Subpart EEE, a source documents in the operating record that they are 
complying with the otherwise applicable Section 112 and 129 
requirements specified under Sec.  63.1209(q).
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    \218\ Examples include 40 CFR part 60, subparts CCCC and DDDD 
for commercial and industrial solid waste incinerators, 40 CFR part 
63, subpart LLL for Portland cement manufacturing facilities, 40 CFR 
part 63, subpart DDDDD for industrial/commercial/institutional 
boilers and process heaters, and 40 CFR part 63, subpart NNNNN for 
hydrochloric acid production facilities.
    \219\ This provision has been discussed in several Federal 
Register notices including 64 FR at 52904 (September 30, 1999), 66 
FR at 35090, 35145 (July 3, 2001), 67 FR at 6979 (February 14, 
2002), and 69 FR at 21203 (April 20, 2004).
    \220\ However, the operating requirements do not apply during 
startup, shutdown, or malfunction provided that hazardous waste is 
not in the combustion chamber. See Sec.  63.1206(b)(1)(i).
---------------------------------------------------------------------------

    The commenter recommends that the complete compliance strategy need 
not be switched over to the alternative section 112 and 129 
requirements when temporarily switching to the alternative standards. 
In general, we disagree. The intent of Sec.  63.1206(b)(1)(ii) is to 
ensure that a source is complying with all requirements of sections 112 
and 129 as an alternative mode of operation in lieu of the requirements 
under Subpart EEE. In the 1999 final rule we stated that the source 
must comply with all otherwise applicable standards under the authority 
of sections 112 and 129. Specifically, the source must comply with all 
of the applicable notification requirements of the alternative 
regulation, comply with all of the monitoring, recordkeeping, and 
testing requirements of the alternative regulation, modify the Notice 
of Compliance (or Documentation of Compliance) to include the 
alternative mode(s) of operation, and note in the operating record the 
beginning and end of each period when complying with the alternative 
regulation. See 64 FR at 52904. A source that elects to comply with 
otherwise applicable standards under Sec.  63.1206(b)(1)(ii) must 
specify all requirements of those standards, not only the emission 
standards applicable under the sections 112 and 129 standards, but also 
the associated monitoring and compliance requirements and notification, 
reporting, and recordkeeping requirements in the operating record under 
Sec.  63.1209(q).
    The commenter suggests that a source should be able to comply with 
the otherwise applicable emission standards, while continuing to 
operate under the associated compliance requirements for the HAP under 
Subpart EEE. An example would be a cement kiln source complying with 
the dioxin and furan monitoring requirements under Sec.  63.1209(k) of 
Subpart EEE for the dioxin and furan standards under Sec.  63.1343(d) 
under Subpart LLL. We did not determine, when promulgating the 
provisions of Sec. Sec.  63.1206(b)(1)(ii) and 63.1209(q)(1), that the 
monitoring provisions under Subpart EEE are equivalent to the 
associated monitoring requirements under the otherwise applicable 112 
and 129 standards, or indeed, whether they are even well-matched. Such 
a determination would require notice and opportunity for comment, which 
we have not provided. However, this should not be interpreted to mean 
that a similar determination could not be made on a site-specific basis 
given that the MACT general provisions allow a source to request 
alternative monitoring procedures under Sec.  63.8(f)(4). Certainly, a 
source can apply under this provision that the compliance requirements 
under Subpart EEE satisfy the associated monitoring requirements under 
the otherwise applicable 112 and 129 standards.
    We also disagree with the commenter that emissions testing under 
the alternative standards of sections 112 and 129 is an example of an 
illogical requirement under Sec.  63.1206(b)(1)(ii). Performance 
testing generally is required to demonstrate compliance with the 
emission standards and to establish limits on specified operating 
parameters to ensure compliance is maintained. In order to take 
advantage of the alternative under Sec.  63.1206(b)(1)(ii), a source 
needs to show that compliance with and establish operating parameter 
limits for the otherwise applicable standards of sections 112 and 129. 
Thus, testing in order to establish operating parameter limits will be 
necessary. However, this does not mean that a separate performance test 
with the alternative sections 112 or 129 standards is necessarily 
required. We note that a source can make use of the performance test 
waiver provision under Sec.  63.7(h) of the general provisions to 
request that the performance test under the alternative sections 112 
and 129 standards be waived because the source is meeting the relevant 
standard(s) on a continuous basis by continuing to comply with Subpart 
EEE for the relevant HAP. This approach may be practicable for sources 
that can demonstrate that their level of performance during testing 
under Subpart EEE, including the associated operating and monitoring 
limits, will undoubtedly ensure continuous compliance with the 
emissions standards and the associated operating limits of alternative 
sections 112 and 129 standards.
    Finally, the commenter notes that Subpart LLL (the alternative 
section 112 standards for cement kilns) includes opacity monitoring 
while Subpart EEE may not. The commenter states that this unnecessarily 
would require duplicate systems and compliance with redundant limits 
because of the bag leak detection and particulate matter detection 
system requirements under Subpart EEE. We respond that Subpart LLL 
specifies opacity as a standard (see Sec.  63.1343(b)(2)), and, 
therefore, cement kilns subject to Subpart EEE must comply with the 
opacity standard when electing to comply temporarily with the 
requirements of Subpart LLL. We note that the opacity standard under 
Subpart EEE does not apply to cement kilns that are equipped with a bag 
leak detection system under Sec.  63.1206(c)(8) and to sources using a 
particulate matter detection system under Sec.  63.1206(c)(9). However, 
a cement kiln may use an opacity monitor that meets the detection limit 
requirements as the detector for a bag leak detection system or 
particulate matter detection system. See Part Four, Section VIII.A-C of 
the preamble.

K. Periodic DRE Testing and Limits on Minimum Combustion Chamber 
Temperature for Cement Kilns

    Comment: Several commenters oppose the need for cement kilns that 
burn at locations other than the normal flame zone to demonstrate 
compliance with the destruction and removal efficiency (DRE) standard 
during each comprehensive performance test. These commenters recommend 
that EPA remove the requirement of Sec.  63.1206(b)(7)(ii) for cement 
kilns citing that existing rule provisions (i.e., the requirements 
under Sec.  63.1206(b)(5) pertaining to changes that may adversely 
affect compliance) are sufficient to require additional DRE testing 
after changes are made that may adversely affect combustion efficiency. 
Commenters question EPA's position that cement kilns that burn 
hazardous waste at locations other than the normal flame zone 
demonstrate a variability in DRE sufficient to justify the expense of 
re-testing for DRE with each performance test. Commenters point to 
EPA's data base that includes DRE results from over 30 tests with 
nearly 250 runs showing consistent DRE results, including sources 
burning hazardous waste at locations other than the normal flame zone, 
being achieved by cement kilns. The commenters note several burdens 
associated with DRE

[[Page 59500]]

testing that do not result in improved environmental benefit including 
the purchase of expensive exotic virgin chemicals for performance 
testing, the risks to workers and contractors associated with the 
handling of these chemicals, and increasing the length of operation at 
stressful kiln operating conditions necessary to conduct DRE testing at 
minimum combustion chamber temperatures. Alternatively, commenters 
recommend that EPA revise the DRE requirements such that periodic 
testing is no longer required for cement kilns (that burn at locations 
other than the normal flame zone) after they have successfully achieved 
the DRE standard over multiple testing cycles (e.g., two or three) 
under similar testing regimes. That is, the source should only be 
required to demonstrate compliance with the DRE standard a maximum of 
two or three times until the source (that burns at locations other than 
the normal flame zone) modifies the system in a manner that could 
affect the ability of it to achieve the DRE standard.
    Response: We are revising the requirements of Sec.  
63.1206(b)(7)(ii) such that cement kilns that feed hazardous waste at 
locations other than the normal flame zone need only demonstrate 
compliance with the DRE standard during three consecutive comprehensive 
performance tests provided that the source has successfully 
demonstrated compliance with the DRE standard in each test and that the 
design, operation, and maintenance features of each of the three tests 
are similar. These revisions do not affect sources that burn hazardous 
waste only in the normal flame zone.\221\
---------------------------------------------------------------------------

    \221\ The DRE demonstration for these sources need be made only 
once during the operational life of a source, either before or 
during the initial comprehensive performance test, provided that the 
design, operation, or maintenance features do not change in a manner 
that could reasonably be expected to affect the ability to meet the 
DRE standard. See Sec. Sec.  63.1206(b)(7) and 63.1207(c)(2)(ii). 
The source would ensure continued compliance by operating under the 
operating parameter limits established during this DRE test.
---------------------------------------------------------------------------

    Prior to today's change, we required sources that feed hazardous 
waste in locations other than the flame zone to perform periodic DRE 
testing every 5 years to ensure that the DRE standard continues to be 
achieved over the life of the unit. See Sec.  63.1206(b)(7)(ii). We 
justified this requirement because of concerns that sources that feed 
hazardous waste at locations other than the flame zone have a greater 
potential of varying DRE performance due to their hazardous waste 
firing practices. As we stated in the 1999 rule, we were concerned that 
the DRE may vary over time due to the design and operation of the 
hazardous waste firing system, and that those variations may not be 
identical or limited through operating limits set during a single DRE 
test (similar to what we concluded for sources that burn hazardous 
waste only in the normal flame zone). See 64 FR at 52850.
    Commenters now question the need for subsequent DRE testing at 
cement kilns that feed hazardous waste at locations other than the 
normal flame zone once a cement kiln demonstrates compliance with the 
MACT DRE standard. The regulatory requirement for the destruction and 
removal efficiency standard has proved to be an effective method to 
determine appropriate process controls necessary for the combustion of 
hazardous waste. We are not convinced that only one DRE test is 
sufficient to ensure that a cement kiln that burns hazardous waste at 
locations other than the normal flame zone will continue to meet the 
DRE standard because temperatures are lower and gas residence times are 
shorter at the other firing locations. This is especially true given 
the industry trend to convert to the more thermally efficient 
preheater/precalciner kiln manufacturing process.\222\ Precalciner 
kilns use a secondary firing system (i.e., flash furnace) at the base 
of the preheater tower to calcine the raw material feed outside the 
rotary kiln. This results in two separate combustion processes that 
must be controlled `` one in the kiln and the other in the flash 
furnace. The gas temperature necessary for calcining the limestone raw 
material in the flash furnace is lower than the temperature required 
making the clinker product. We conclude, therefore, that it is 
necessary, in spite of the concerns raised by commenters, to retain 
periodic DRE testing to ensure continued compliance with the DRE 
standard necessary for the control of nondioxin/furan organic HAP.
---------------------------------------------------------------------------

    \222\ For example, Ash Grove Cement in Chanute, KS replaced 
their two wet process cement kilns with one preheater/precalciner 
kiln in 2001. Holcim Inc in Holly Hill, SC has also recently 
constructed a new preheater/precalciner kiln to replace two wet 
process cement kilns. Keystone Cement Company in Bath, PA is 
considering replacing their two wet process cement kilns with a new 
preheater/precalciner kiln. See docket item OAR-2004-0022-0384.
---------------------------------------------------------------------------

    We also acknowledge, however, the concerns raised by the 
commenters. Our DRE data base of operating cement kilns includes 
results from approximately 25 DRE tests and nearly 200 runs.\223\ All 
data show compliance with the DRE standard. Of these, approximately 
one-quarter of the data are from cement kilns that burned hazardous 
waste at locations other than the normal flame zone (e.g., injecting 
waste at midkiln in a wet process kiln), but we do not have DRE results 
from every operating cement kiln. Considering available DRE data and 
the concerns of the commenters, we believe that DRE testing during 
three consecutive comprehensive performance tests is sufficient to 
provide needed certainty about DRE performance while reducing the 
overall costs and toxic chemical handling concerns to the regulated 
source. Thus, we are revising the requirements of Sec.  
63.1206(b)(7)(ii) such that cement kilns that feed hazardous waste at 
locations other than the normal flame zone need only demonstrate 
compliance with the DRE standard during three consecutive comprehensive 
performance tests provided that the source has successfully 
demonstrated compliance with the DRE standard in each test and that the 
design, operation, and maintenance features of each of the three tests 
are similar. If a facility wishes to operate under new operating 
parameter limits that could be expected to affect the ability to meet 
the DRE standard, then the source would need to conduct another DRE 
test. Once the facility has conducted another three DRE tests under the 
new operating limits, then subsequent DRE testing would not be 
required. Accordingly, we are revising the requirements of Sec.  
63.1206(b)(7)(ii).
---------------------------------------------------------------------------

    \223\ U.S. EPA, ``Final Technical Support Document for HWC MACT 
Standards, Volume III: Selection of MACT Standards and 
Technologies,'' Section 23.4, September 2005.
---------------------------------------------------------------------------

    Comment: Several commenters support EPA's proposal to delete the 
requirement to establish an operating limit on the minimum combustion 
chamber temperature for dioxin/furans under Sec.  63.1209(k)(1) for 
cement kilns. These commenters point to the high temperatures of 
approximately 2500[deg]F required to make the clinker product. These 
high temperatures are fixed by the reaction kinetics and thermodynamics 
occurring in the burning zone and cannot be reduced below minimum 
values at the whim of the operator and still make a marketable product. 
In addition to deleting the minimum combustion chamber temperature 
limit for dioxin/furans, commenters also recommend, for similar 
reasons, that EPA delete the minimum combustion chamber temperature 
requirement under Sec.  63.1209(j)(1) associated with the destruction 
and removal efficiency standand. Commenters note that demonstrating the 
minimum temperature requires operating under stressful operating 
conditions that can

[[Page 59501]]

lead to upset conditions and potentially damage the integrity of the 
manufacturing equipment. Other commenters oppose, however, deletion of 
the minimum combustion chamber temperature limit for cement kilns. 
These commenters state that all combustion sources, including cement 
kilns, must meet a minimum combustion chamber temperature limit to 
control dioxin/furans and organic HAP emissions given that some cement 
kilns feed hazardous waste at locations other than the high temperature 
clinker-forming zone of the kiln.
    Response: We are deleting as proposed the requirement to establish 
a minimum combustion chamber temperature limit for dioxin/furan under 
Sec.  63.1209(k)(2) for cement kilns. See 69 FR at 21343. However, we 
retain the requirement for cement kilns to establish and comply with a 
minimum combustion chamber temperature limit for the destruction and 
removal efficiency standard under Sec.  63.1209(j)(1).\224\
---------------------------------------------------------------------------

    \224\ Under the interim standards, cement kilns must establish 
and continuously monitor limits on minimum gas temperature in the 
combustion zone for both the dioxin/furan and DRE standards. As 
discussed in the preceding paragraph, a source may not need to 
conduct DRE testing during each comprehensive performance test. If 
DRE testing is required, then the source will need to establish a 
minimum combustion zone temperature limit as required under the DRE 
standard. However, if DRE testing is not required, then (according 
to the changes made today) the cement kiln will not be required to 
establish the minimum combustion chamber temperature limit under the 
dioxin/furan standard during a subsequent comprehensive performance 
test. The minimum combustion chamber temperature operating limit 
established during previous testing remains in effect, however.
---------------------------------------------------------------------------

    As discussed in the 1999 rule, nondioxin/furan organic hazardous 
air pollutants are controlled by the DRE standard and the carbon 
monoxide and hydrocarbon standards. See 64 FR at 52848-52852. This 
standard was not reopened in the present rulemaking. We note, however, 
that the DRE standard determines appropriate process controls necessary 
for the combustion of hazardous waste. Establishing and monitoring a 
minimum temperature of the combustion chamber is a principal factor in 
ensuring combustion efficiency and destruction of toxic organic 
compounds. As discussed in the previous response, we believe this is 
especially true given the industry trend to convert to the more 
thermally efficient preheater/precalciner kiln manufacturing process, 
which use two separate combustion processes. We conclude that it is 
necessary, in spite of the concerns raised by commenters, to retain the 
minimum combustion chamber temperature limit as related to the DRE 
standard to ensure that combustion efficiency within the entire kiln 
system is maintained for the control of nondioxin/furan organic HAP.
    However, we acknowledge the difficulties that cement kiln operators 
face in establishing a minimum combustion chamber temperature limit, 
including the stressful operating conditions necessary to establish the 
limit. As we stated at proposal, our data indicate that limiting the 
gas temperature at the inlet to the particulate matter control device 
is a critical parameter in controlling dioxin/furan emissions in cement 
kilns. See 69 FR at 21344. Therefore, we believe that an operating 
limit on the minimum combustion chamber temperature is less important 
to ensure compliance with the dioxin/furan standard than to ensure 
compliance with the DRE standard. Thus, we remove the requirement to 
establish a minimum combustion chamber temperature limit for dioxin/
furan under Sec.  63.1209(k)(2) for cement kilns. This change does not 
affect the other operating parameter limits under Sec.  63.1209(k) that 
must be established for dioxin/furans, including a limit on the gas 
temperature at the inlet to the particulate matter control device.
    Comment: One commenter supports the use of previous minimum 
combustion zone temperature data, regardless of the test age, in lieu 
of conducting new, stressful DRE testing. That is, if a cement kiln is 
required to conduct future DRE tests, then the source should not have 
to re-establish a minimum combustion chamber temperature limit during 
the new test. Rather, the source should have the option to submit 
minimum combustion chamber temperature results in lieu of re-
establishing the limit.
    Response: We reject the commenter's suggestion for reasons 
discussed above. We believe that it is necessary to retain the link 
between the minimum combustion chamber temperature limit and the DRE 
test itself, which will ensure that the combustion efficiency of the 
entire system will be maintained for the control of nondioxin/furan 
organic HAP.
    Comment: One commenter supports deletion of the minimum combustion 
chamber temperature requirement for dioxin/furan under Sec.  
63.1209(k)(2) for lightweight aggregate kilns.
    Response: We reject the commenter's suggestion. Our data base of 
dioxin/furan emissions data shows substantial variability in test 
results at each source.\225\ This may indicate that factors other than 
limiting kiln exit gas temperatures may be influencing significantly 
dioxin/furan formation in lightweight aggregate kilns. As such, we 
conclude that removing the minimum combustion chamber temperature limit 
would not be appropriate at this time due to the uncertain nature of 
dioxin/furan formation in lightweight aggregate kilns. Thus, we are 
retaining the requirement to establish a minimum combustion chamber 
temperature limit for dioxin/furans under Sec.  63.1209(k)(2) and Sec.  
63.1209(j)(1) for lightweight aggregate kilns.
---------------------------------------------------------------------------

    \225\ For example, dioxin/furan emissions from source number 307 
range from a low of 0.024 to a high of 57.9 ng TEQ/dscm. See 
``Source Category Summary Sheets'' available in the docket or USEPA, 
``Final Technical Support Document for HWC MACT Standards, Volume 
II: HWC Data Base,'' September 2005.
---------------------------------------------------------------------------

L. One Time Dioxin and Furan Test for Sources Not Subject to a 
Numerical Limit for Dioxin and Furan

    Comment. Commenters support the one-time dioxin/furan test for 
sources not subject to a numerical dioxin and furan standard. 
Commenters agree that previous testing should be allowed to document 
the one time test.
    Response. The final rule requires sources that are not subject to a 
standard with numerical dioxin and furan levels \226\ to conduct a one-
time dioxin and furan test as part of their initial comprehensive 
performance testing: lightweight aggregate kilns that elect to control 
the gas temperature at the kiln exit rather than comply with a dioxin/
furan standard of 0.20 ng TEQ/dscm, solid fuel boilers, liquid fuel 
boilers with wet or no air pollution control systems, and HCl 
production furnaces. We will use these data as part of the process of 
addressing residual risk under CAA section 112(f) and evaluating future 
MACT standards under section 112(d)(6). The results may also be used as 
part of the RCRA omnibus permitting process.
---------------------------------------------------------------------------

    \226\ These sources do, however, need to comply with the carbon 
monoxide or hydrocarbon standards, as well as the DRE standard as 
surrogates to comply with today's dioxin and furan emissions control 
requirements.
---------------------------------------------------------------------------

    Comment. EPA proposed that source not subject to a numerical dioxin 
and furan limit conduct a dioxin and furan test under worst-case 
conditions. Commenters state that operating under worst-case conditions 
is inconsistent with the CAA Section 112(f) process, which is to 
consider actual (i.e., normal) emissions. Commenters suggest that we 
require the tests be conducted under normal to above normal conditions.
    Response. Section 112 (f) standards evaluate allowable emission 
levels, although actual emissions levels may also be considered. See 70 
FR at 19998-

[[Page 59502]]

19999 (April 15, 2005). Although we agree with the commenter that, in 
general, emissions in the range of normal to maximum are considered for 
section 112(f) determinations, we believe that dioxin/furan testing to 
provide information of use in section 112(f) residual risk 
determinations should be conducted under conditions where controllable 
operating conditions are maximized to reflect the full range of 
expected variability of those parameters which can be controlled. This 
is because dioxin/furan emissions may relate exponentially with the 
operating conditions that affect formation. We believe that dioxin/
furan emissions relate exponentially with gas temperature at the inlet 
to an ESP or fabric filter,\227\ and are concerned that emissions may 
also relate exponentially with the operating parameters (discussed 
below) that affect emissions from sources subject to the one-time 
dioxin/furan emissions test. Emissions testing under operating 
conditions that are in the range of ``normal to above normal'' may be 
exponentially lower than emissions under operating conditions 
reflecting maximum daily variability of the source. Since testing under 
normal operating conditions makes no effort to assess operating 
variability, emissions during such testing would fail to reflect 
expected daily maximum operating variability and so would not represent 
time-weighted average emissions and would under-represent health risk 
from chronic exposure.
---------------------------------------------------------------------------

    \227\ See USEPA, ``Technical Support Document for HWC MACT 
Standards, Volume IV: Compliance,'' July 1999, Chapter 3.
---------------------------------------------------------------------------

    Although we acknowledge that sources will not exhibit maximum 
operating variability each day of operation, we believe that it is 
important to assess the upper range of emissions that these sources may 
emit to properly evaluate under section 112(f) whether the MACT 
standards for dioxin/furan for these sources (i.e., absent a numerical 
emission standard) protect public health with an ample margin of 
safety.\228\
---------------------------------------------------------------------------

    \228\ Dioxin/furan are some of the most toxic compounds known 
due to their bioaccumulation potential and wide range of health 
effects, including carcinogenesis, at exceedingly low doses. 
Exposure via indirect pathways is a chief reason that Congress 
singled out dioxin/furan for priority MACT control in CAA section 
112(c)(6). See S. Rep. No. 128, 101st Cong. 1st Sess. at 154-155.
---------------------------------------------------------------------------

    In addition, we note that emissions reflecting daily maximum 
variability would be most useful for section 112(d)(6) determinations 
in the future because they would represent the full range of emissions 
variability that results from controllable operating conditions.
    For these reasons, the final rule requires sources to test under 
feed and operating conditions that are most likely to reflect maximized 
expected daily variability of dioxin/furan emissions, as proposed. Such 
testing is similar to a comprehensive performance test to demonstrate 
compliance with a numerical dioxin/furan emission standard where 
operating limits would be established based on operations during the 
test. As a practical matter, however, we note that many of the 
operating parameters discussed below, although controllable to some 
extent, cannot be quantified and cannot be controlled to replicate the 
condition in a future test. In addition, some operating parameters we 
identify may not have as strong a relationship to dioxin/furan 
emissions as others. Consequently, the operating conditions are 
generally described subjectively.
    Based on currently available research, you should consider the 
following factors to ensure that you conduct the test under operating 
conditions that seek to fully reflect maximum daily variability of 
dioxin/furan emissions: (1) Dioxin/furan testing should be conducted at 
the point in the maintenance cycle for a boiler when the boiler tubes 
are more fouled and soot-laden, and not after maintenance involving 
soot or ash removal from the tubes; (2) dioxin/furan testing should be 
performed following (or during) a period of feeding normal or greater 
quantities of metals; (3) dioxin/furan testing should be performed 
while feeding normal or greater quantities of chlorine; (4) the flue 
gas temperature in some portion of the heat recovery section of a 
boiler should be within the dioxin formation temperature window of 750 
to 400[deg]F during the testing; (5) the testing should not be 
conducted under optimal combustion conditions (e.g., combustion chamber 
temperature should be in the range of normal to the operating limit; 
hazardous waste feedrate and combustor through put should be in the 
range of normal to maximum); (6) for units equipped with wet air 
pollution control systems, the testing should be conducted after a high 
solids loading has developed in the scrubber system (consistent with 
normal operating cycles); and (7) for solid fuel boilers, the sulfur 
content of the coal should be equivalent to or lower than normal coal 
sulfur levels (within the range of sulfur levels that the source 
utilizes), and the gas temperature at the inlet to the electrostatic 
precipitator or fabric filter should be close to the operating limit. 
In addition, unless sulfur compounds are routinely fed to the boler, 
dioxin/furan testing should not be performed after a period of firing 
high sulfur fuel or injection of sulfur additives. See 69 FR at 21308 
for more information.
    Comment: Commenters state that we should delete the one-time 
testing requirement for dioxin and furans. The Clean Air Act at Section 
114(a)(1)(D) allows EPA to request ``any person'' to sample emissions. 
Applying the Section 114 authority to an entire subcategory of sources 
is overly broad, particularly in the context of having already 
established appropriate surrogates for dioxin and furan in a MACT rule. 
Commenters are not aware of EPA taking this approach in previous 
efforts. (Section 114 requests have focused on collecting existing 
information from sources facing future MACT standards). Commenters 
oppose this approach because it established a precedent they do not 
favor, and will bring about significant costs and difficulties to 
provide the data. They suggest that we delete the proposed requirements 
for a one-time dioxin and furan test.
    Response: We believe that section 114(a)(1)(D) of the Clean Air Act 
provides us the authority to require sources to conduct a one time test 
to generate data which can be used in making later section 112 (f) 
determinations for the source category. The results of the testing may 
also inform the section 112(d)(6) review and the RCRA omnibus 
permitting processes. The fact that section 114 specifically indicates 
that a purpose of gathering information under section 114 is to assist 
in developing national rules indicates that the provision can have wide 
sweep extending to all sources in a category. See 69 FR at 21307-308 
for a full explanation.
    We believe a dioxin and furan test costs approximately $10,000 when 
conducted along with other testing. We do not believe this cost is 
significant, and sources must only perform this test once, not more 
frequently as would be the case to ensure compliance with a standard. 
We also allow sources to use prior testing to meet this requirement, 
and allow sources to use ``data in lieu'' so they can test one source 
if they have more than one of the same identical sources.
    We do not believe that obtaining these data will be difficult, and 
note that the permitting authority can assist sources in planning their 
tests.

M. Miscellaneous Compliance Issues

    Comment: Several commenters state that Sec.  63.1206(c)(3)(iv) 
requiring an automatic waste feed cutoff (AWFCO) if

[[Page 59503]]

a parameter linked to the AWFCO is exceeded should be revised to 
reflect Sec.  63.1206(c)(2)(v)(A)(1). Section 63.1206(c)(2)(v)(A)(1) 
states that, if the AWFCO is affected by a malfunction such that the 
malfunction itself prevents immediate and automatic cutoff of the 
hazardous waste feed, you must cease feeding hazardous waste as quickly 
as possible.
    Response: We agree with commenters in principle, but note that the 
automatic waste feed cutoff system may fail for reasons other than a 
malfunction. That is, equipment or other failures are malfunctions only 
if they meet the definition of malfunction at Sec.  63.2. Failures that 
result from improper maintenance or operation are not malfunctions. 
Consequently, the final rule revises Sec.  63.1206(c)(3)(iv) to state 
that if the AWFCO is affected by a failure such that the failure itself 
prevents immediate and automatic cutoff of the hazardous waste feed, 
you must cease feeding hazardous waste as quickly as possible. Revised 
Sec.  63.1206(c)(3)(iv) does not refer to malfunctions, however, 
because the AWFCO system may fail for reasons other than a malfunction. 
The reference in Sec.  63.1206(c)(2)(v)(A)(1) to malfunctions is 
appropriate because that paragraph addresses requirements during 
malfunctions.
    Comment: Several commenters note that the proposed rule did not 
include a sunset provision for the Interim Standards applicable to 
incinerators, cement kilns, and lightweight aggregate kilns after the 
compliance date of the standards we promulgate today (i.e., the 
``permanent replacement standards''). Commenters are concerned that, 
although the Agency intends for the replacement standards to be more 
stringent than the Interim Standards, that may not be the case in all 
situations because of the different format used for some of the 
replacement standards. For example, several of the replacement 
standards for cement kilns and lightweight aggregate kilns are 
expressed as hazardous waste thermal emissions.
    Response: Although we are promulgating the replacement standards in 
a format that ensures they are not less stringent than the Interim 
Standards, we agree with commenters that not sunsetting the Interim 
Standards may lead to confusion as to which standards apply. 
Consequently, we include a sunset provision in today's rule for the 
Interim Standards. The Interim Standards will be superseded by the 
final rule promulgated today on the compliance date.
    We note, however, that the Interim Standards for total chlorine 
continue to apply to sources that establish health-based limits for 
total chlorine under Sec.  63.1215. Consequently, we have incorporated 
the total chlorine Interim Standards in Sec.  63.1215 as they apply as 
a cap to the health-based emission limits.
    Comment: Several commenters state that the rule should allow 
extrapolation of ash and chlorine feedrates to establish feedrate 
limits corresponding to the particulate matter and total chlorine 
standards. Commenters believe the rationale we use to allow 
extrapolation of metals feedrates is also applicable to ash and 
chlorine.
    Response: The final rule does not allow you to extrapolate ash and 
chlorine feedrates achieved during the comprehensive performance test 
to establish feedrate limits comparable to the particulate matter and 
total chlorine emission standards.
    We do not allow extrapolation of ash to the particulate matter 
emission standard because particulate matter (i.e., soot) may form in 
the combustor, particularly at times of unstable combustion conditions. 
Consequently, extrapolating from ash feedrates may underestimate 
particulate matter emissions and may not ensure compliance with the 
particulate matter emission standard.
    We do not allow extrapolation of chlorine feedrates to the total 
chlorine emission standard because chlorine feedrate is an operating 
parameter limit to ensure compliance with the semivolatile metal 
emission standard. Because an increase in chlorine feedrate can 
increase the volatility of semivolatile metals and we do not know the 
precise relationship among chlorine feedrate, metal volatility, and 
metals emissions, extrapolating the chlorine feedrate achieved during 
the comprehensive performance test to a feedrate comparable to the 
total chlorine emission standard may not ensure compliance with the 
semivolatile metal emission standard. If a source complies with the 
semivolatile metals emission standard under Sec.  63.1207(m)(2) where 
the performance test is waived, however, by assuming zero system 
removal efficiency and limiting the semivolatile feedrate (expressed as 
a maximum theoretical emission concentration) to the level of the 
emission standard, the source may request under Sec.  63.1209(g)(1) to 
extrapolate chlorine feedrates during the comprehensive performance 
test up to the total chlorine emission standard.
    Comment: Several commenters state that the proposed regulatory 
language under Sec. Sec.  63.1206(b)(9)(i) and 63.1206(b)(10)(i) is 
inconsistent with the proposed preamble, which states that sources 
should be allowed to petition for alternative standards provided they 
submit information showing that HAP contributions to emissions from the 
raw materials are preventing the source from achieving the emissions 
standard though the source is using MACT control.\229\ The commenters 
state that the proposed regulatory language, despite the intent 
signaled in the proposed preamble, inappropriately excludes the 
provisions of Sec. Sec.  63.1206(b)(9)(i) and 63.1206(b)(10)(i) as an 
alternative option when complying with the replacement emission 
standards under Sec. Sec.  63.1220 and 63.1221.
---------------------------------------------------------------------------

    \229\ For example, see 69 FR at 21268.
---------------------------------------------------------------------------

    Response: We agree with the commenters. The proposed regulatory 
text inadvertently excluded the alternative standard provisions from 
use by cement and lightweight aggregate kilns under the replacement 
standards. Accordingly, we are revising the introductory text of 
Sec. Sec.  63.1206(b)(9)(i) and 63.1206(b)(10)(i) by making the 
alternative standards available under the replacement standards.
    Comment: One commenter states that the availability of the 
alternative standard for mercury under Sec.  63.1206(b)(10)(i) should 
not be conditioned upon mercury being present only at levels below the 
detection limit in raw materials, as specified under Sec.  
63.1206(b)(10)(i)(B). The commenter suggests that the approach for 
mercury should be the same as for other HAP such as semi- and low 
volatile metals under Sec.  63.1206(b)(10)(i)(A).
    Response: The commenter misreads the alternative standard 
provisions under Sec.  63.1206(b)(10)(i). We note that Sec.  
63.1206(b)(10) includes two separate provisions for cement kilns. The 
first provision allows sources to petition for an alternative standard 
when a source cannot achieve a standard because of HAP metal or 
chlorine concentrations in their raw material feedstocks cause an 
exceedance of a standard despite the source's use of MACT control. See 
Sec.  63.1206(b)(10)(i)(A). The term ``regulated metals'' specified in 
Sec.  63.1206(b)(10)(i)(A) includes mercury, semivolatile metals, and 
low volatile metals. The second provision allows a source to petition 
for an alternative mercury standard when mercury is not present at 
detectable levels in the source's raw materials. Sec.  
63.1206(b)(10)(i)(B). These two provisions are indeed separate as

[[Page 59504]]

discussed in the 1999 rule. See 64 FR at 52962-967. Also note that the 
conjunction separating paragraphs (b)(10)(i)(A) and (b)(10)(i)(B) is 
``or,'' not ``and.''
    Given the potential confusion of the term ``regulated metals,'' we 
are clarifying the regulatory text by specifying the three metal HAP 
volatility groups that comprise the term ``regulated metals.'' See 
revised Sec.  63.1206(b)(10)(i)(A). Finally, given that the alternative 
standard provisions are similar for lightweight aggregate kilns, we are 
also clarifying Sec. Sec.  63.1206(b)(9)(i)(A) and (b)(9)(iv).

IX. Site-Specific Risk Assessment Under RCRA

A. What Is the Site-Specific Risk Assessment Policy?

    The Site-Specific Risk Assessment (SSRA) Policy has undergone 
several revisions since its inception in the 1993 draft Combustion 
Strategy. Currently, it is the same policy as we expressed in the 1999 
final rule preamble. In the 1999 rule, we recommended that for 
hazardous waste combustors subject to the Phase 1 MACT standards, 
permitting authorities should evaluate the need for an SSRA on a case-
by-case basis. Further, while SSRAs are not anticipated to be necessary 
for every facility, they should be conducted where there is some reason 
to believe that operation in accordance with the MACT standards alone 
may not be protective of human health and the environment. For 
hazardous waste combustors not subject to the Phase 1 standards, we 
continued to recommend that SSRAs be conducted as part of the RCRA 
permitting process. See 64 FR 52841. Since 1999, we have provided 
additional clarification of the appropriate use of the SSRA policy and 
technical guidance in an April 10, 2003 memorandum from OSWER's 
Assistant Administrator to the EPA Regional Administrators entitled, 
``Use of the Site-Specific Risk Assessment Policy and Guidance for 
Hazardous Waste Combustion Facilities'' (see Docket <greek-i> OAR-2004-
0022-0083). Most importantly, in this memorandum we reiterated that 
where a permitting authority concludes that a risk assessment is 
necessary for a particular combustor, the basis for this decision must 
be substantiated in each case. The factual and technical basis for any 
decisions to conduct a risk assessment must be included in the 
administrative record for the facility per 40 CFR 124.7, 124.8, 124.9, 
and 124.18. In addition, if the facility, or any other party, files 
comments on a draft permit decision objecting to the permitting 
authority's conclusions regarding the need for a risk assessment, the 
permitting authority must respond fully to the comments. Any permit 
conditions determined to be necessary based either on the SSRA, or 
because the facility declined to conduct an SSRA, also must be 
documented and supported in the administrative record.
    Today, we are codifying additional regulatory language providing 
authority for SSRAs while maintaining the same basic SSRA policy. It is 
important to note that all of the requirements of Part 124 referred to 
above will continue to apply to actions taken in accordance with the 
additional regulatory language we are codifying. The SSRA regulatory 
provisions, which establish that the need for an SSRA should be 
determined on a case-by-case basis, apply equally to both Phase 1 and 
Phase 2 sources.

B. Why Might SSRAs Continue To Be Necessary for Sources Complying With 
Phase 1 Replacement Standards and Phase 2 Standards?

    EPA conducted a national evaluation of human health and ecological 
risk for the MACT standards as proposed in the 1996 NPRM and then 
revised the evaluation to include more facilities for the 1999 final 
rulemaking. Based on the results of the final national risk evaluation 
for hazardous air pollutants (excluding non-dioxin products of 
incomplete combustion), we concluded that sources complying with the 
MACT standards generally would not pose an unacceptable risk to human 
health or the environment. For today's final rule, we did not conduct 
another national risk assessment as we did for the 1999 rule. Rather, 
for both the April 20, 2004 NPRM and today's final rule we conducted a 
comparative risk analysis, comparing the Phase 1 Replacement and Phase 
2 Standards to the 1999-promulgated Phase 1 Standards, to determine if 
there were any significant differences that might influence or impact 
the potential risk. Similar to the proposal, the comparative analysis 
conducted for today's final rule focused on several key 
characteristics: emission rates, stack height, stack gas buoyancy, 
meteorological conditions (which include a number of variables), 
population parameters including density and radial distribution, and 
correlations among the characteristics themselves. The results of the 
comparative analysis suggest that the MACT standards for both Phase 1 
and Phase 2 sources are generally protective. Therefore, separate 
national emissions standards under RCRA are unnecessary. See Part 
Seven: How Does the Final Rule Meet the RCRA Protectiveness Mandate? 
Although we have concluded that the Phase 1 Replacement and Phase 2 
standards are generally protective, as we discussed in the 2004 
proposal (69 FR 21325), there may be instances where we cannot assure 
that emissions from each source will be protective of human health and 
the environment, and therefore an SSRA may be necessary. Furthermore, 
it should be noted that, just as for the risk assessment for the 1999 
rule, the comparative analysis does not account for cumulative 
emissions at a source or background exposures from other sources.
    Before discussing factors that may lead permit authorities to 
consider whether or not to conduct an SSRA, it should be noted that the 
Agency generally does not expect that facilities that have conducted 
risk assessments will have to repeat them. As we explained in the 1999 
final rule preamble, changes to comply with the MACT standards should 
not cause an increase in risk for the vast majority of facilities given 
that the changes will likely be the addition of pollution control 
equipment or a reduction in the hazardous waste being burned (see 64 FR 
52842). Instances where a facility may need to repeat a risk assessment 
would be related to changes in conditions that would likely lead to 
increased risk. For example, if the only changes at a facility relate 
to the exposed population (a new housing development is constructed 
within a few square miles of the source), what was once determined to 
be protective under a previous risk assessment may now be beyond 
acceptable levels. Another example would be where a hazardous waste 
burning cement kiln that previously monitored hydrocarbons in the main 
stack elects to install a mid-kiln sampling port for carbon monoxide or 
hydrocarbon monitoring to avoid restrictions on hydrocarbon levels in 
the main stack. Thus, the stack hydrocarbon emissions may increase (64 
FR 52843, footnote 29). In such situations, we would anticipate that 
the risk assessment would not have to be entirely redone. It may be as 
limited as collecting relevant new data for comparison purposes, 
leading to a decision not to repeat any portion of a risk assessment. 
Or, it may be more inclusive such that modifications would be made to 
specific inputs to or aspects of the risk assessment using data from a 
previous risk assessment, risk burn or comprehensive performance test. 
In recognition of this, we have added an additional factor to the list 
of factors at Sec.  270.10(l)(1) to indicate that a previously 
conducted risk assessment

[[Page 59505]]

would be relevant in evaluating changes in conditions that may lead to 
increased risk. The factor reads as follows: ``Adequacy of any 
previously conducted risk assessment, given any subsequent changes in 
conditions likely to affect risk.'' The following discussion is 
intended mainly to address facilities that have not yet conducted an 
SSRA (i.e., where it has been determined that one is needed).
    In the proposal we discussed our conclusion that almost all of the 
proposed standards for Phase 1 sources were equivalent to or more 
stringent than the 1999 final standards, with the exception of the 
mercury standard for new and existing LWAKs and the total chlorine 
standard for new LWAKs. However, there are additional standards for 
Phase 1 sources finalized in today's rulemaking that are less stringent 
than the 1999 final standards. In addition to those discussed in the 
proposal, the following standards are less stringent than the 1999 
final standards: mercury for new cement kilns and semi-volatile metals 
for existing cement kilns; dioxin/furan for existing and new LWAKs, 
mercury for existing and new LWAKs, and total chlorine for existing and 
new LWAKs. Because these standards exceed the levels which were 
evaluated in the 1999 national risk assessment, especially with respect 
to mercury and dioxin/furan standards for which the national risk 
assessment showed high end risks at or near levels of concern, permit 
authorities may decide on a case-by-case basis that an SSRA is 
appropriate to determine whether the less stringent Replacement 
standards are protective. In addition, the comparative analysis results 
suggest concern regarding the dioxin/furan standard for LWAKs and thus, 
permit authorities may consider site-specific factors in determining 
whether the standard is sufficiently protective.
    Specific to Phase 2 sources, we mentioned earlier that we conducted 
the same comparative risk analysis for Phase 2 sources as we did for 
Phase 1 sources (i.e., by comparing the Phase 2 standards to the 1999 
final standards for Phase 1 sources). Although several MACT standards 
for Phase 2 sources are more stringent than the BIF standards under 
RCRA, there are a few MACT standards that may be cause for concern on a 
case-by-case basis, as they are either less stringent than some of the 
1999 final standards or the comparative risk analysis suggests concern. 
They are: The particulate matter standard (and certain metals such as 
antimony and thallium), mercury standard, and total chlorine standard 
for solid fuel-fired boilers (SFBs); the dioxin/furan standard (carbon 
monoxide or total hydrocarbon as surrogate controls, versus a numerical 
standard) for HCl production furnaces; and the dioxin/furan standard 
for liquid fuel-fired boilers (LFBs) with dry APCDs. In addition, 
dioxin/furan emissions data for LFBs with wet or no APCDs indicate an 
observed level (1.4 ng TEQ/dscm) of more than three times the highest 
dioxin/furan standard evaluated in the 1999 national risk assessment 
(69 FR 21285).\230\ Thus, these standards may warrant site-specific 
risk consideration, especially with respect to the dioxin/furan 
standards. That is, due to the complexity of the dioxin/furan formation 
mechanism and given the toxicity of dioxin/furans,\231\ an SSRA may be 
needed based on the specific emission levels of each source not subject 
to a numerical standard. For additional discussion on the 
protectiveness of standards, please refer to Part Seven: How Does the 
Final Rule Meet the RCRA Protectiveness Mandate?
---------------------------------------------------------------------------

    \230\ The comparative analysis did not specifically suggest 
concern as it has for other source categories, but per the reference 
to the proposal, we have some concern regarding the protectiveness 
of the standard.
    \231\ There is ongoing uncertainty in cancer and other health 
effects levels for chlorinated dioxins and furans.
---------------------------------------------------------------------------

    There are also site-specific factors beyond the standards that can 
be important to the SSRA decision making process. As discussed in the 
proposal, examples include a source's proximity to a water body or 
endangered species habitat, repeated occurrences of contaminant 
advisories for nearby water bodies, the number of hazardous air 
pollutant emission sources within a facility and the surrounding 
community, whether or not the waste feed to the combustor is made up of 
persistent, bioaccumulative or toxic contaminants, and sensitive 
receptors with potentially significantly different exposure pathways, 
such as Native Americans (69 FR 21326). Also, there are several 
uncertainties inherent in the 1999 national risk assessment.\232\ Thus, 
the same uncertainties related to the fate and transport of mercury in 
the environment and the biological significance of mercury exposures in 
fish (i.e., once mercury has been transformed into methylmercury, it 
can be ingested by the lower trophic level organisms where it can 
bioaccumulate in fish tissue), as well as the risk posed by non-dioxin 
products of incomplete combustion, remain today and may influence a 
permitting authority's decision. Last, we are finalizing the option for 
Phase 2 area sources to comply with specific MACT standards as provided 
by CAA Sec.  112(c)(6) specific pollutants authority. These area 
sources may need to conduct an SSRA for the remaining RCRA standards 
that they choose to comply with (i.e., since they do not address the 
potential risk from indirect exposures to long-term deposition of 
metals onto soils and surface waters).\233\
---------------------------------------------------------------------------

    \232\ Uncertainties stem from a lack of information regarding 
the behavior of mercury in the environment and a lack of sufficient 
emissions data and parameter values (e.g., bioaccumulation values) 
for nondioxin products of incomplete combustion. See 64 FR 52840-
52841.
    \233\ Currently, there are only five area sources that this may 
apply to; they are interim status units in the process of conducting 
an SSRA as part of their final permits.
---------------------------------------------------------------------------

    In addition to the examples provided in the previous paragraph, we 
also expressed that an SSRA may be necessary with respect to the 
proposed thermal emission standards. With respect to Phase 1 sources, 
we had noted in the proposal that the thermal emission standards for 
semi-volatile and low volatile metals for cement kilns and LWAKs may be 
of concern because they directly address emissions attributable to 
hazardous waste versus a source's total HAP metal emissions. See 69 FR 
21326. However, we are requiring sources to comply with both the 
thermal emission standards and the Interim Standards in today's final 
rulemaking, since compliance with the thermal emission standards may 
not always assure compliance with the Interim Standards. As a result, 
the thermal emission standards for cement kilns and LWAKs no longer 
pose the uncertainties that they had in the proposal.\234\ In regard to 
Phase 2 sources, the concern at the time of proposal was with respect 
to the thermal emission standards for liquid fuel-fired boilers. 
However, the comparative analysis for today's final rulemaking for 
liquid fuel-fired boilers, which is based on total stack emissions from 
these sources while assuming compliance with the thermal standards, 
does not suggest that risks for LFBs are cause for concern (except as 
otherwise noted, e.g., dioxins).
---------------------------------------------------------------------------

    \234\ An exception would be the semivolatile metal Interim 
standard for existing cement kilns, which is less stringent than the 
1999 final standard. As we noted, permit authorities may consider 
the need for an SSRA as a result.
---------------------------------------------------------------------------

C. What Changes Are EPA Finalizing With Respect to the Site-Specific 
Risk Assessment Policy?

    In the 1999 final rule preamble, we included a revised site-
specific risk assessment (SSRA) policy recommendation to account for 
promulgation of the new technology-based CAA MACT standards for Phase

[[Page 59506]]

1 sources. We recommended that permitting authorities evaluate the need 
for an SSRA on a case-by-case basis for hazardous waste combustors 
subject to the Phase 1 MACT standards. For hazardous waste combustors 
not subject to the Phase 1 standards, we continued to recommend that 
SSRAs be conducted as part of the RCRA permitting process if necessary 
to protect human health and the environment. We indicated that the RCRA 
omnibus provision authorized permit authorities to require applicants 
to submit SSRA results where an SSRA was determined to be necessary. 
For the reasons described in the previous subsection, we believe that 
additional controls may be necessary on a site-specific basis to ensure 
that adequate protection is achieved in accordance with RCRA.
    Consequently, because SSRAs are likely to continue to be necessary 
at some facilities (mainly those that have not previously conducted an 
SSRA), we concluded that it is more appropriate to include a regulatory 
provision that explicitly provides for the permit authority to require 
SSRAs on a case-by-case basis and add conditions to RCRA permits based 
on SSRA results. Therefore, instead of relying on RCRA Sec.  3005(c)(3) 
and its associated regulations at Sec.  270.10(k) when permitting 
authorities conduct or require a risk assessment on a site-specific 
basis (i.e., as applicable to those newly entering the RCRA permit 
process), we had proposed to codify the authorities provided by 
sections 3004(a) and (q) and 3005(b). See proposed regulations at 69 FR 
21383-21384, Sec. Sec.  270.10(l) and 270.32(b)(3). In proposing to 
codify these authorities, we stated that we were not requiring that 
SSRAs automatically be conducted for hazardous waste combustion units, 
but that the decision of whether or not a risk assessment is necessary 
must be made based upon relevant factors associated with an individual 
combustion unit and that there are combustion units for which an SSRA 
will not be necessary. Further, we explained that the proposed language 
would provide notice to the regulated community that an SSRA may be 
necessary to support a source's permit, while reminding the permit 
agency of the need to evaluate whether an SSRA would be necessary on a 
site-specific basis.
    Despite our efforts to explain that by codifying these provisions, 
we are only modifying the statutory authority under which we implement 
the SSRA policy while maintaining the same SSRA policy from a 
substantive standpoint, commenters generally opposed EPA's proposed 
codification. The comment most frequently presented was that the 
proposed regulatory language is not helpful to anyone (i.e., regulated 
community, the public or permitting agencies), is redundant with the 
omnibus authority, and sets an extremely low hurdle for regulators to 
require SSRAs.
    We disagree that the new regulatory language is not helpful and 
that it sets an extremely low hurdle for regulators to require SSRAs. 
We believe that the new provisions are beneficial in two ways: (1) They 
provide notice to the regulated community and public that an SSRA may 
be necessary to support a source's permit; and (2) they remind the 
permitting agencies of the importance of evaluating whether an SSRA 
would be necessary on a site-specific basis. The new regulatory 
provision in no way expands or supplements the authority on which EPA 
had previously relied--i.e., omnibus and Sec.  270.10(k), thus it does 
not provide any more or less authority to permit authorities (i.e., 
lower or raise the hurdle) to require SSRAs. We agree that, because the 
proposed language provides permitting authorities with no greater 
authority than the omnibus authority, it is somewhat duplicative of 
Sec.  270.10(k). However, as noted, EPA believes this provision offers 
important benefits to both the agency and the regulated community, and 
as explained further below, EPA has adopted a slightly modified version 
of the proposal pursuant to RCRA Sec.  3004(a) and Sec.  3005(b). See 
also discussion in subsection F.
    Another common view expressed by commenters is that, although 
extensive risk assessments that have been performed for more than a 
decade, showing lack of risk to human health and the environment, EPA 
continues to require SSRAs without a technical evaluation of the 
historical results. To the contrary, EPA Regional permit writers have 
found that certain chemicals (especially dioxin and mercury)\235\ pose 
excess risk in certain circumstances--even under the Interim 
Standards--and consequently find it necessary to assess risk to human 
health and the environment based on site-specific conditions at the 
facility. In EPA Regions 7 and 10 for example, some facilities have 
RCRA risk-based permit conditions that establish more frequent sampling 
or limits on feed rate for specified metals to ensure that ecologically 
sensitive areas are not adversely impacted.
---------------------------------------------------------------------------

    \235\ Dioxin is a common risk driver due to ongoing uncertainty 
in cancer and other health effects levels for chlorinated dioxins 
and furans. Mercury is also a common risk driver due to 
uncertainties implicit in the quantitative mercury analysis. See 
discussion in Part Seven, Section II. and 65 FR 52997. Thus, it is 
not uncommon for permit authorities to require risk-based RCRA 
permit limits (based on risk assessment results) to control 
emissions of these pollutants.
---------------------------------------------------------------------------

    Many commenters also state that CAA Sec.  112(f) residual risk 
process is the appropriate method to assess risk for hazardous waste 
combustors complying with MACT, not RCRA risk assessments. 
Specifically, one commenter argued that EPA lacked statutory authority 
to rely on the omnibus provisions to require SSRA and SSRA-based 
controls on the grounds that Sec.  112(f) of the Clean Air Act 
establishes a specific provision to control any residual risk from 
combustor emissions. We disagree with commenters for two reasons. 
First, as we explained in the 1999 final rule preamble, the omnibus 
provision is a RCRA statutory requirement and the CAA does not override 
RCRA. Promulgation of the MACT standards, therefore, does not 
duplicate, supersede, or otherwise modify the omnibus provision or its 
applicability to the sources covered by today's rule. Second, the SSRA 
under RCRA is usually conducted prior to issuance of the final permit. 
The CAA residual risk determination is generally made eight years after 
promulgation of the MACT standards for a source category. Accordingly, 
a permit authority currently facing a permit decision could not rely on 
these yet unwritten residual risk standards to resolve its identified 
concern that the MACT standard may not be sufficiently protective at an 
individual site. In addition, even though we believe that Sec.  
3005(c)(3) and its associated regulations provide the authority to 
require and perform SSRAs and to write permit conditions based on SSRA 
results, we are not relying on these provisions as the authority for 
Sec.  270.10(l). Rather, we are relying on Sec. Sec.  3004(a) and (q) 
and 3005(b). See 69 FR 21327.
    With respect to the costs incurred when conducting an SSRA, several 
commenters raised the concern that our approximations do not include 
portions of actual costs (e.g., data gathering, QA/QC, and third party 
consultants, risk assessors, and plant personnel time to coordinate and 
review SSRA efforts and collect facility data), thus resulting in 
artificially low costs. Commenters cited additional reasons why they 
feel that EPA's cost estimates are too low including our assumptions 
that: (1) SSRAs are a one-time or infrequent cost; (2) most SSRAs fall 
under ``normal'' versus ``unusual'' situations; and (3) the cost of 
conducting a risk burn during a

[[Page 59507]]

trial burn adds only 20% more to the cost.
    Regarding the comment that we did not include actual costs for our 
estimates of overall costs to conduct an SSRA, we agree that some costs 
were overlooked. We did include the costs related to conducting an SSRA 
under ``normal'' and ``unusual'' conditions, SSRA data collection in 
conjunction with a regular performance burn, and a full independent 
risk burn including protocol, sampling, analysis, and report. However, 
we did not capture facility time associated with data collection and 
management related to the SSRA. Consequently, we have revised our cost 
estimate for performing these activities; see chapter 4 of the 
background document entitled, Assessment of the Potential Costs, 
Benefits, and Other Impacts of the Hazardous Waste Combustion MACT 
Replacement Standards--Final Rule, October 12, 2005.
    In response to the broader comment that our cost estimates are too 
low (for several reasons mentioned previously), we agree that our 
estimate of a 20% additional cost to conduct a risk burn with a trial 
burn may have been conservative and therefore, we have adjusted our 
previous estimate to include a range of 20% to 40%. The total SSRA cost 
range has also been updated from $141K-$370K to $157K-$815K.\236\ With 
respect to our assumption that the majority of SSRAs are conducted 
under ``normal'' conditions (lending to overall lower cost estimates), 
we do believe that the majority of future SSRAs will fall under the 
``normal'' conditions.\237\ We believe this is appropriate due to: lack 
of new facilities coming on-line for which there is no previous test 
data; availability of commercial modeling software; and finalization of 
the ``Human Health Risk Assessment Protocol for Hazardous Waste 
Combustion Facilities'' guidance, or ``HHRAP'' guidance. However, we do 
recognize that some facilities can be more complex than others in the 
hazardous waste combustion universe. Therefore, we have identified a 
portion of facilities that are likely to incur ``unusual'' costs for a 
future SSRA and have revised our cost analysis to reflect inclusion of 
these higher-cost facilities. See background document, Assessment of 
the Potential Costs, Benefits, and Other Impacts of the Hazardous Waste 
Combustion MACT Replacement Standards--Final Rule, October 12, 2005.
---------------------------------------------------------------------------

    \236\ The high end of this range applies only to those systems 
operating under ``unusual conditions'' (the available data suggest 
that there are only five such facilities).
    \237\ Normal conditions assume use of previously collected 
performance burn data, use of standard commercial modeling software 
that meet Agency guidance, and limited interactions with State and 
Federal oversight authorities. Unusual conditions assume the need 
for site-specific modeling, extensive interactions with stakeholders 
and regulators, an extended time frame, and targeted ecological 
analyses.
---------------------------------------------------------------------------

    Also, we maintain our assumption that SSRAs generally represent a 
one-time cost unless a facility significantly changes its operations or 
if receptors change such that an increase in risk is anticipated as a 
result. Even so, as explained earlier in subsection B., we would 
anticipate that the risk assessment would not have to be entirely 
redone. It may be as limited as collecting relevant new data for 
comparison purposes, leading to a decision not to repeat any portion of 
a risk assessment. Or, it may be more inclusive such that modifications 
would be made to specific inputs to or aspects of the risk assessment 
using data from a previous risk assessment, risk burn or comprehensive 
performance test. With respect to chemical weapons demilitarization 
facilities, we recognize that due to their specialized waste streams 
and multiple treatment units, SSRAs, in many cases, are not one-time 
events and as a result, their SSRA costs are relatively high. The high 
costs can be attributed to the necessity for each chemical weapons 
demilitarization facility to perform surrogate trial burns and then 
agent trial burns for each furnace and each agent campaign (e.g., GB 
(Sarin), VX, and HD (Sulfur Mustard)). For example, a chemical weapons 
demilitarization facility would conduct GB trial burns on all the 
furnaces and then complete destruction of the GB stockpile, followed by 
VX trial burns and VX stockpile and finally, the HD trial burns and the 
HD stockpile. This effectively extends the input to the risk assessment 
of the trial burn data over most of the operational life of the 
facility.
    Last, several commenters raised the concern that EPA's proposal to 
codify the authority to require SSRAs on a case-by-case basis and add 
conditions to RCRA permits based on SSRA results, violates the due 
process protections afforded under the current structure, where SSRAs 
are required and performed pursuant to RCRA Sec.  3005(c)(3) omnibus 
authority. Commenters were further concerned that the proposed language 
in Sec.  270.10(l) would remove existing procedural safeguards by 
allowing the Agency to require a very expensive SSRA before the draft 
permit is even issued, thus violating EPA's own procedural standards as 
well as due process. It appears as though commenters believe that the 
procedures (and procedural protections) currently applicable whenever 
an SSRA is conducted are unique to circumstances in which the 
permitting authority proceeds under the authority of RCRA Sec.  
3005(c)(3)--the ``omnibus'' provision. This is incorrect. All of the 
specific procedural requirements the commenters have raised would be 
applicable whether the permitting authority proceeded under Sec.  
270.10(l), as EPA proposed, or pursuant to RCRA Sec.  3005(c)(3) and 
Sec.  270.10(k), as is the current practice.
    All of the requirements established in Part 124 continue to apply, 
whether EPA proceeds under Sec.  270.10(l) or under Sec.  270.10(k). As 
we discussed in the proposal, the basis for the decision to conduct a 
risk assessment, or to request additional information to evaluate risk 
or determine whether a risk assessment is necessary, must be included 
in the administrative record for the facility and made available to the 
public during the comment period for the draft permit. See 40 CFR 124.7 
[statement of basis]; 124.9 [administrative record for draft permit]; 
124.18 [administrative record for final permit]. If the facility, or 
any other party, files comments on a draft permit decision objecting to 
the permitting authority's conclusions regarding the need for a risk 
assessment, the permitting authority must respond fully to the 
comments. Any permit conditions determined to be necessary based either 
on the SSRA, or because the facility declined to conduct an SSRA, also 
must be documented and supported in the administrative record.
    The commenters' concern that Sec.  270.10(l) allows the permitting 
authority to require the SSRA prior to the issuance of a draft permit, 
and therefore the applicant would have no opportunity to comment or 
challenge that determination, is equally unfounded. There is 
effectively no practical or substantive distinction between the 
circumstance when a permit authority communicates the decision that an 
SSRA is necessary to issue the permit prior to issuing the draft 
permit, or as part of the draft permit. In either case, if a facility 
refuses to provide a risk assessment or data to support a risk 
assessment requested under this provision, the regulations at part 124 
make clear that the appropriate recourse is for the permit authority to 
deny the permit (See 40 CFR 124.3(d); 124.6(b) and 270.10(c). The basis 
for the denial would essentially be the same in either case--that the 
information before the agency gives rise to a concern that the MACT may 
not be sufficiently protective,

[[Page 59508]]

which the agency is unable to dispel based on the information before 
it. Consequently, the permit authority cannot determine that the permit 
meets RCRA's standard for permit issuance. An as noted above, all of 
the requirements of Part 124 would apply to actions taken in accordance 
with Sec.  270.10(l). For additional discussion on this issue, please 
refer to the Response to Comments background document for this final 
rule.\238\
---------------------------------------------------------------------------

    \238\ See final Response to Comment to the HWC MACT Standards, 
Volume 5, Miscellaneous.
---------------------------------------------------------------------------

    Despite the many reasons offered by commenters opposing our 
proposal, we continue to believe that our proposed approach is 
appropriate. As discussed in the proposal (69 FR 21327) and in the 
previous subsection, although the Phase 1 Replacement and Phase 2 
standards provide a high level of protection (i.e., they are generally 
protective) to human health and the environment, thereby allowing us to 
nationally defer the RCRA emission requirements to MACT, additional 
controls may be necessary on an individual source basis to ensure that 
adequate protection is achieved in accordance with RCRA. Until today, 
we have relied exclusively upon RCRA Sec.  3005(c)(3) and its 
associated regulations at Sec.  270.10(k) when conducting or requiring 
an SSRA. We continue to believe that Sec.  3005(c)(3) and its 
associated regulations provide the authority to require and perform 
SSRAs and to write permit conditions based on SSRA results. In fact, as 
the next subsection will explain, EPA will likely continue to include 
permit conditions based on the omnibus authority in some circumstances 
when conducting these activities, and state agencies in states with 
authorized programs will continue to rely on their own authorized 
equivalent. However, because SSRAs are likely to continue to be 
necessary at some facilities, we are finalizing the authority to 
require them on a case-by-case basis and add conditions to RCRA permits 
based on SSRA results under the authority of RCRA Sec. Sec.  3004(a) 
and (q) and 3005(c). Therefore, we are finalizing Sec. Sec.  270.10(l) 
and 270.32(b)(3) with some minor modifications to provide further 
clarification of the Agency's intent.

D. How Will the New SSRA Regulatory Provisions Work?

    The new regulatory provisions are finalized under both base program 
authority (Sec.  3004(a) and Sec.  3005(b)) and HSWA authority (Sec.  
3004(q)). That is, changes made to regulations applicable to boilers 
are promulgated under HSWA authority, whereas changes made to 
regulations applicable to incinerators are promulgated under non-HSWA 
authority. Consequently, when it is determined that an SSRA is needed, 
the applicability of these provisions will vary according to the type 
of combustion unit (whether it is regulated under 3004(q), or only 
3004(a) and 3005(b)), and the authorization status of the state. 
Depending on the facts, the new authority would be applicable, or the 
omnibus provision would remain the principal authority for requiring 
SSRAs and imposing risk-based conditions where appropriate. See 69 FR 
21327.
    According to the state authorization section of this preamble (see 
Part Five, Section IV.), EPA does not consider these provisions to be 
either more or less stringent than the pre-existing federal program, 
since they simply make explicit an authority that has been and remains 
available under the omnibus authority and its implementing regulations. 
Thus, states with authorized equivalents to the federal omnibus 
authority will not be required to adopt these provisions, so long as 
they interpret their omnibus authority broadly enough to require risk 
assessments where necessary.\239\
---------------------------------------------------------------------------

    \239\ Authorized states are required to modify their programs 
only when EPA enacts federal requirements that are more stringent or 
broader in scope than existing federal requirements. This applies to 
regulations promulgated under both HSWA and non-HSWA authorities.
---------------------------------------------------------------------------

    The provisions of Sec. Sec.  270.10(l) and 270.32(b)(3) adopted in 
today's rule are substantially similar to the provisions EPA proposed. 
Section 270.10(l) continues to explicitly provide that a permit 
authority has the authority to evaluate, on a case-by-case basis, the 
need for an SSRA. EPA has also retained its proposed language that 
explicitly provides that, where an SSRA is determined to be necessary, 
the permit authority may require a permittee or an applicant to conduct 
an SSRA, or to provide the regulatory agency with the information 
necessary to conduct an SSRA on behalf of the permittee/applicant. The 
final provision also essentially retains the standard laid out in the 
proposal: that a permit authority may decide that an SSRA is warranted 
based on a conclusion that additional controls beyond those required 
pursuant to 40 CFR parts 63, 264, 265, or 266 may be needed to ensure 
protection of human health and the environment under RCRA. In Sec.  
270.32(b)(3), EPA has also explicitly codified the authority for permit 
authorities to require that the applicant provide information, if 
needed, to make the decision of whether an SSRA should be required.
    However, EPA has adopted some further clarifications to the final 
provisions in response to comments. In response to comments that the 
regulatory language EPA had proposed still fails to provide the 
regulated community with adequate notice that an SSRA might be 
required, and what that might entail, EPA has included additional 
language to address those issues. Specifically, EPA has included a 
sentence stating that the information required under Sec.  270.10(l) 
can include the information necessary to evaluate the potential risk to 
human health and/or the environment resulting from both direct and 
indirect exposure pathways. EPA has also added language to remind 
permit authorities that the determination that the MACT standards may 
not be sufficiently protective is to be based only on factors relevant 
to the potential risk from the hazardous waste combustion unit at the 
site, and has provided a list of factors to guide the permit authority 
in making that determination. See subsections E. and F. for further 
discussion. The applicability language of Sec. Sec.  270.19, 270.22, 
270.62, and 270.66 also has been amended to allow a permit authority 
that has determined that an SSRA is necessary to continue to apply the 
relevant requirements of these sections on a case-by-case basis and as 
they relate to the performance of the SSRA after the source has 
demonstrated compliance with the MACT standards.
    As previously noted, the requirements at 40 CFR Part 124 continue 
to apply to actions taken to implement Sec.  270.10(l). Thus, if the 
permitting authority concludes that a risk assessment or additional 
information is necessary for a particular combustor, the permitting 
authority must provide the factual and technical basis for its decision 
in the permit's administrative record and must make it available to the 
public during the comment period for the draft permit. If the facility 
or any other party files comments on a draft permit decision objecting 
to the permitting authority's conclusions regarding the need for an 
SSRA, the authority must respond fully to the comments. In addition, 
the SSRA must be included in the administrative record and made 
available to the public during the comment period. Any additional 
conditions and limitations determined to be necessary as a result of 
the SSRA must be documented and supported in the administrative record 
as well.\240\
---------------------------------------------------------------------------

    \240\ Additional clarification on the appropriate use of the 
SSRA policy and technical guidance is provided in the April 10, 2003 
memorandum from Marianne Lamont Horinko entitled ``Use of the Site-
Specific Risk Assessment Policy and Guidance for Hazardous Waste 
Combustion Facilities.'' (See Docket <greek-i> OAR-2004-0022-0083).

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[[Page 59509]]

E. What Were Commenters' Reactions to EPA's Proposed Decision Not To 
Provide National Criteria for Determining When an SSRA Is or Is Not 
Necessary?

    In the proposal, we stated that we were not proposing national 
criteria (e.g., guiding factors) for determining when an SSRA is 
necessary. Although we had developed a list of qualitative guiding 
factors for permit authorities to consult when considering the need for 
an SSRA in the September 1999 final rulemaking (revised from the April 
1996 NPRM), we never intended for them to comprise an exclusive list 
for several reasons. Mainly, we felt that the complexity of multi-
pathway risk assessments precluded the conversion of the qualitative 
guiding factors into more definitive criteria. See 69 FR 21328.
    Commenters generally agreed that the risk assessment guidance and 
policy should not be codified. They agreed in principle that it is 
important to keep the decision to require an SSRA flexible because 
factors vary from facility to facility. However, several commenters 
raised the concern that the proposed language of Sec.  270.10 (l) was 
too vague. For example, one commenter suggested that any additional 
guidance clarifying how risk assessments should be performed and that 
providing standards or goals to be achieved by the operating conditions 
would be helpful. Another commenter felt that EPA should identify 
specific factors that the regions and authorized states should 
consider, and specific criteria that should be met, before requiring an 
SSRA or additional emission controls or other standards. We agree with 
commenters that additional guidance would be beneficial and have taken 
a number of actions in this regard. First, EPA is adopting a more 
detailed regulatory provision that provides a non-exclusive list of 
guiding factors for permit authorities to use in determining whether 
the MACT will be sufficiently protective at an individual site, and 
consequently, whether an SSRA is warranted. Section 270.10(l) now 
requires that the permit writer's evaluation of whether compliance with 
the standards of 40 CFR part 63, Subpart EEE alone is protective of 
human health or the environment be based on factors relevant to the 
potential risk from a hazardous waste combustion unit, including, as 
appropriate, any of the specifically enumerated factors. These factors 
reflect the eight guiding factors that EPA has discussed in several 
rule preambles. See 61 FR 17372, 64 FR 52842, and 69 FR 21328. However, 
EPA has also incorporated a few minor revisions to reflect the 
standards promulgated today, and to reflect the fact that the factors 
will be codified.
    EPA has revised the language of the factors so that the language is 
consistent between the provisions. Consistency of phrasing is generally 
more important in regulations, which are binding, than in guidance. For 
example, some of the factors listed in the 1999 preamble used the 
phrase ``presence or absence'' while other used the phrase ``identities 
and quantities.'' EPA has adopted the phrase ``identities and 
quantities,'' on the grounds that it more precisely expresses the 
concept intended by both phrases. EPA has also made minor revisions to 
reduce redundant text, and to shorten the provisions, in the interests 
of clarity. For example, rather than addressing the proximity of 
receptors in two factors, EPA addresses this issue in a single factor. 
However, nothing contained in either of the original factors was 
deleted as part of this revision. None of the revisions described here 
substantively change the issues to be considered from those contained 
in the original eight guiding factors.
    In addition to these minor technical revisions, EPA has included 
language to clarify that one potentially relevant factor for 
consideration is the ``identities and quantities of persistent, 
bioaccumulative or toxic pollutants considering enforceable controls in 
place to limit those pollutants.'' This reflects changes made between 
the proposed and final MACT standards (e.g., the proposed rule called 
for beyond-the-floor dioxin limits for some sources; those were not 
promulgated in the final rule).
    Another change is the EPA has deleted the factor that listed 
``concerns raised by the public.'' The regulation will allow the 
decision to be based on any one of the listed factors, and public 
concern, unaccompanied by an identifiable risk, would not provide an 
adequate basis for determining that an SSRA was warranted.
    Finally, as discussed previously in subsection B., EPA has added an 
additional factor to indicate that a previously conducted risk 
assessment would be relevant in evaluating changes in conditions that 
may lead to increased risk. The factor reads as follows: ``Adequacy of 
any previously conducted risk assessment, given any subsequent changes 
in conditions likely to affect risk.'' See Sec.  270.10(l)(1).
    One commenter raised the concern that the eight guiding factors the 
Agency specified in its Federal Register notice at 64 FR 52842 
(September 30, 1999) did not adequately focus on the central question 
of whether there are likely to be emissions that would be uncontrolled 
under the Subpart EEE final rule. They argued that, as an example, 
under guiding factor <greek-i>5, if the waste containing highly toxic 
constituents are being addressed by the Subpart EEE standards, the fact 
that there might be such wastes should not justify an SSRA. The 
commenter apparently misunderstands that the factors were not intended 
to function as stand-alone criteria for requiring an SSRA--i.e., to use 
their example, the commenter believes that the mere fact that highly 
toxic constituents are present in the waste would justify an SSRA 
without consideration of whether the MACT emission standards were 
sufficiently protective. This is an incorrect reading of EPA's proposed 
regulation. Rather, the factors were always intended to function as 
considerations that might be relevant to the determination of whether 
the MACT was sufficiently protective. However, the regulatory structure 
EPA has adopted in the final rule makes perfectly clear that the 
critical determination is that ``compliance with the standards of 40 
CFR part 63, Subpart EEE alone may not be protective of human health or 
the environment.'' Further, the provision states that this 
determination is to be based only on factors relevant to the potential 
risk from the hazardous waste combustion unit, including, as 
appropriate, the listed factors. EPA believes that these provisions 
make clear that the determination of whether to require an SSRA is to 
be based on consideration of the conditions at the facility site, 
including, for example, an evaluation of all enforceable controls in 
place to limit emissions. Further discussion of EPA's revised 
provisions can be found in subsection F.
    Second, as discussed in more detail below, EPA is issuing a revised 
risk assessment guidance document that we believe will provide 
additional insight to help users. While clearly delineating between 
risk management and risk assessment, the HHRAP explains in great detail 
a recommended process for performing and reporting on cost-effective, 
scientifically defensible risk assessments. It includes numerous 
recommended defaults, while at the same time is flexible enough to 
incorporate site-specific values. Although the HHRAP provides numerous 
recommendations, it remains merely guidance and consequently leaves the 
final decisions up to the permitting authority. We believe that

[[Page 59510]]

the revised HHRAP guidance will provide further assistance to permit 
writers, risk assessors and facilities in determining whether or not to 
conduct an SSRA and what and how much information is required for the 
SSRA.

F. What Are EPA's Responses to the Cement Kiln Recycling Coalition's 
Comments on the Proposal and What is EPA's Final Decision on CKRC's 
Petition?

    In the proposal, we provided a lengthy discussion in response to 
CKRC's petition for rulemaking (69 FR 21325-21331). In its petition, 
CKRC presented two requests with respect to SSRAs: (1) That EPA repeal 
the existing SSRA policy and technical guidance because CKRC believes 
that the policy and guidance ``are regulations issued without 
appropriate notice and comment rulemaking procedures''; and (2) after 
EPA repeals the policy and guidance, ``should EPA believe it can 
establish the need to require SSRAs in certain situations, CKRC urges 
EPA undertake an appropriate notice and comment rulemaking process 
seeking to promulgate regulations establishing such requirements.'' 
Additionally, CKRC stated that it does ``not believe that these SSRAs 
are in any event necessary or appropriate'' and that they disagree with 
EPA's use of the RCRA omnibus provision as the authority to conduct 
SSRAs. Finally, CKRC raised three general concerns: (1) Whether an SSRA 
is needed for hazardous waste combustors that will be receiving a RCRA 
permit when the combustor is in full compliance with the RCRA boiler 
and industrial furnace regulations and/or with the MACT regulations; 
(2) how an SSRA should be conducted; and (3) what is the threshold 
level for a ``yes'' or ``no'' decision that additional risk-based 
permit conditions are necessary. We believe our tentative decision in 
the proposal addressed each request and concern presented in their 
petition. However, in its comments, CKRC has restated many of the same 
issues with new emphasis. Thus, we believe it is appropriate to address 
their major comments in the following paragraphs.\240a\
---------------------------------------------------------------------------

    \240a\ CKRC provided numerous comments organized by subtitles. 
Rather than relying on this format in the preamble, we have 
organized the comments and responses according to the concerns 
initially raised in the petition, and consistent with the discussion 
presented in the proposal.
---------------------------------------------------------------------------

1. Whether SSRAs Are Necessary for Facilities in Full Compliance With 
BIF or MACT Regulations
    In its comments, CKRC continues to question the need for any SSRAs 
at facilities that are in full compliance with the MACT EEE standards. 
CKRC also states that ``[our] Petition challenged EPA to explain why, 
if there is any need for SSRAs at all under RCRA, there is a rational 
basis for why it has limited the entire SSRA program to hazardous waste 
combustors.'' They argue that, ``The point is that if the ``omnibus'' 
words in RCRA mean what EPA says they mean for hazardous waste 
combustors, why do they not mean the same thing for all of the other 
TSD facilities that also pose the same kind of ``what-if'' 
hypotheticals that EPA throws out in its preamble?''
    As discussed above in subsection B., and in greater detail below, 
EPA believes that risk assessments will continue to be necessary at 
some facilities. For example, based on the inconclusive results from 
the national risk assessment conducted for the 1999 final rule and the 
comparative risk analysis conducted for today's rule, EPA is not able 
to conclude that all MACT standards will be sufficiently protective for 
every facility (e.g., non-dioxin PICs not previously modeled, no 
numerical dioxin/furan emission standard for solid fuel-fired boilers, 
liquid fuel-fired boilers with wet or no APCDs, and hydrochloric acid 
production furnaces, etc.). EPA also provided examples of site-specific 
factors that might lead risk assessors to decide that the MACT 
standards may not be sufficiently protective, and therefore an SSRA may 
be necessary (e.g., if a source's emissions are comprised of persistent 
bioaccumulative or toxic contaminants). EPA also discussed this issue 
at length in both the 2004 proposal, and the 1999 rule preamble. See 69 
FR 21326 and 64 FR 52842. Given these uncertainties, the SSRA provides 
significant support for the Agency's 1006(b) determination supporting 
the elimination of separate RCRA emission standards for MACT EEE 
facilities.
    We disagree that our discussion of standards (and site-specific 
factors) that may warrant a risk evaluation at certain types of 
facilities are mere ``what-if'' hypotheticals. The examples that we 
discussed in both the earlier preambles and above were based on the 
1999 national risk assessment and a comparative risk analysis, which 
concluded that either there was not enough information to make a 
definitive protectiveness determination or that uncertainty in cancer 
and other health effects levels of dioxin and furans, for instance, 
make it difficult to draw conclusions about potential risks. 
Furthermore, the discussions with respect to the protectiveness of 
certain standards (i.e., some are less stringent today than the 1999 
standards) in subsection B., present a reasonable basis for permitting 
authorities to consider whether or not risk should be evaluated. In 
support of our position that the examples we have provided in the 1999 
final rule preamble, the 2004 proposed rule preamble, and this final 
rule, are more than ``what-if'' hypotheticals, we have placed copies of 
completed risk assessments where risk-based limits were found to be 
necessary in the docket for today's final rule (see OAR-2004-0022).
    The CKRC fails to acknowledge that there are many aspects of 
hazardous waste combustors and the combustion process itself, which 
make this category of TSD facilities different from others, and which 
factor heavily into our SSRA policy. Consider that many combustion 
facilities feed a wide array of waste streams comprised of many 
hazardous constituents. The combustion of these constituents results in 
complex chemical processes (which are difficult to predict) occurring 
throughout the combustion unit. The end product is stack emissions 
comprised of a variety of compounds different from those that enter the 
process, and thus are difficult to predict because they can vary 
greatly based on the many variables of the individual combustion unit, 
making them difficult to address (i.e., there are no specific emissions 
standards to limit certain compounds such as products of incomplete 
combustion). For example, in attempting to maximize the destruction of 
organic compounds, products of incomplete combustion are often 
generated as a consequence. Further, due to stack dispersion, hazardous 
waste combustors have the potential to affect several square miles. 
Other types of TSD facilities' operations typically do not encompass 
such complex processes or have the potential to adversely affect 
receptors for several square miles.
    It should be noted that hazardous waste combustors are not the only 
type of TSD subjected to site-specific evaluations of risk. We take a 
site-specific approach to regulating miscellaneous units under Part 
264, subpart X. Because it is not possible to develop performance 
standards and emission limits for each type of treatment unit that may 
fall under this broad category, we rely on general environmental 
performance standards to meet our mandate under Sec. Sec.  3004 (a) and 
(q) that standards governing the operation of hazardous waste 
facilities be protective of human health and the environment. For 
example, Sec.  264.601(c) requires ``Prevention of any release that may 
have adverse effects on human

[[Page 59511]]

health or the environment due to migration of waste constituents in the 
air, considering: * * * (6) the potential for health risks caused by 
human exposure to waste constituents; and * * *'' For all intents and 
purposes, subparts X units are subject to SSRAs as well.
    In addition, the question of whether an SSRA continues to be 
necessary is partly a function of the fact that EPA is seeking to rely 
on CAA MACT standards in order to eliminate RCRA emissions standards 
for these facilities. As noted above, because the MACT is technology-
based, and because of uncertainties in our national risk assessments, 
permit writers' ability to conduct an SSRA in individual cases provides 
important support for our deferral.
    RCRA Sec. Sec.  3004(a) and (q) mandate that standards governing 
the operation of hazardous waste combustion facilities be protective of 
human health and the environment. To meet this mandate, we originally 
developed national combustion standards under RCRA, taking into account 
the potential risk posed by direct inhalation of the emissions from 
these sources. With advancements in risk assessment science since 
promulgation of the original national standards (i.e., 1981 for 
incinerators and 1991 for boilers and industrial furnaces), it became 
apparent that the risk posed by indirect exposure (e.g., ingestion of 
contaminants in the food chain) to long-term deposition of metals, 
dioxins/furans and other organic compounds onto soils and surface 
waters should be assessed in addition to the risk posed by direct 
inhalation exposure to these contaminants. We also recognized that the 
national assessments performed in support of the original hazardous 
waste combustor standards did not take into account unique and site-
specific considerations which might influence the risk posed by a 
particular source. Therefore, until EPA was able to revise its 
regulations, to ensure the RCRA mandate was met on a facility-specific 
level for all hazardous waste combustors, we strongly recommended that 
site-specific risk assessments (SSRAs), including evaluations of risk 
resulting from both direct and indirect exposure pathways, be conducted 
as part of the RCRA permitting process. In those situations where the 
results of an SSRA showed that a facility's operations could pose an 
unacceptable risk (even after compliance with the RCRA national 
regulatory standards), additional risk based, site-specific permit 
conditions could be imposed pursuant to RCRA's omnibus authority, Sec.  
3005(c)(3).
    Rather than establish separate emission standards under RCRA, EPA 
decided to coordinate its revisions to the RCRA emissions standards for 
hazardous waste combustors with the adoption of the MACT standards 
pursuant to Sec.  112(d) of the CAA. See 64 FR 52832. In the rulemaking 
establishing the MACT standards for incinerators, cement kilns and 
lightweight aggregate kilns (Phase 1 sources), relying on RCRA Sec.  
1006(b), EPA determined that in most cases, the MACT standards would be 
sufficiently protective that separate RCRA emission standards and 
operating conditions would not need to be included in the facility's 
RCRA permit. However, for a variety of reasons, EPA lacked sufficient 
factual basis to conclude that a complete deferral of RCRA requirements 
could be supported for all facilities.
    Section 1006(b) conditions EPA's authority to reduce or eliminate 
RCRA requirements on the Agency's ability to demonstrate that the 
integration meets RCRA's protectiveness mandate (42 U.S.C. 6005(b)(1)). 
See Chemical Waste Management v. EPA, 976 F.2d 2, 23, 25 (D.C. Cir. 
1992). To support its RCRA Sec.  1006(b) determination, EPA conducted a 
national evaluation of both direct and indirect human health and 
ecological risks to determine if the MACT standards would satisfy the 
RCRA mandate to protect human health and the environment. That 
evaluation, however, did not quantitatively assess the proposed 
standards with respect to mercury and nondioxin products of incomplete 
combustion. This was due to a lack of adequate information regarding 
the behavior of mercury in the environment and a lack of sufficient 
emissions data and parameter values (e.g., bioaccumulation values) for 
nondioxin products of incomplete combustion. Since it was not possible 
to suitably evaluate the proposed standards for the potential risk 
posed by mercury and nondioxin products of incomplete combustion, in 
order to support our 1006(b) determination, we continued to recommend 
that SSRAs be conducted for some facilities as part of the permitting 
process until we could conduct a further assessment once final MACT 
standards were promulgated and implemented. Specifically, we 
recommended that for hazardous waste combustors subject to the Phase 1 
MACT standards--hazardous waste burning incinerators, cement kilns and 
light-weight aggregate kilns--permitting authorities should evaluate 
the need for an SSRA on a case-by-case basis. We further stated that 
while SSRAs are not anticipated to be necessary for every facility, 
they should be conducted where there is some reason to believe that 
operation in accordance with the MACT standards alone may not be 
protective of human health and the environment. For hazardous waste 
combustors not subject to the Phase 1 standards, we continued to 
recommend that SSRAs be conducted as part of the RCRA permitting 
process. See 64 FR 52841. As discussed in subsection B., EPA believes 
that SSRAs may continue to be necessary for some Phase 1 facilities. 
For the Phase 2 sources, our comparative risk analysis generally 
indicates that, although the MACT standards for Phase 2 sources are 
appreciably more stringent than the current RCRA BIF standards, an SSRA 
may be necessary to confirm that a facility will operate in a way that 
is protective of human health and the environment.
    Thus, for both Phase 1 and Phase 2 sources, we continue to believe 
that SSRAs may be necessary for some facilities.\241\ We generally 
believe the MACT standards will be protective; in most cases they are 
substantially more protective than the existing RCRA part 264, 265, and 
266 requirements. However, because HWCs manage hazardous waste and 
process it by burning and emitting the by-products into the air, a 
multitude of potential exposure pathways exist. These exposure pathways 
can also vary substantially based on site-specific factors associated 
with an individual combustion unit and the surrounding site. Such 
factors make it difficult for the Agency to conclude that a single, 
national risk assessment provides adequate factual support for its 
determination that the technology-based MACT standards will be 
sufficiently protective. This is further complicated by the fact that, 
for certain parameters, the Agency lacked sufficient information to 
quantitatively assess the risk, but is relying on a combination of 
quantitative and qualitative assessments of the MACT standards' 
protectiveness.
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    \241\ As discussed in section B., we expect that facilities that 
have previously conducted an SSRA will not need to conduct another 
in consideration of today's final standards. Only those facilities 
newly subject to the RCRA permitting requirements, or existing 
sources where changes in conditions could lead to increased risk, 
may need to conduct or modify an existing SSRA.
---------------------------------------------------------------------------

    Nonetheless, EPA does not believe that the uncertainty is so great 
that it would preclude a deferral under 1006(b) for the affected 
categories of facilities; nor does EPA believe that these uncertainties 
necessarily support requiring a risk assessment for all such 
facilities. Conditions at the facility

[[Page 59512]]

might confirm that the MACT standards are sufficiently protective, 
without the need for a facility-wide risk assessment. For example, if 
the results of the MACT testing demonstrated that the facility's dioxin 
emissions fall below the levels estimated in the database EPA used for 
its comparative risk assessment, the uncertainties in EPA's comparative 
risk assessment would not, by itself, support a decision to require an 
SSRA. Such decisions require an evaluation of the conditions at the 
site, and EPA believes it important to retain the flexibility for 
permit authorities to take these conditions into account. Accordingly, 
EPA believes that the regulatory structure adopted in today's rule 
strikes the appropriate balance between these competing factors.
    In response to EPA's statement in the proposal that non-HAP 
emissions, which were beyond the direct scope of MACT, may pose risk 
which could necessitate an SSRA (69 FR 21326), CKRC pointed out that 
the same could be said for other types of TSDs, such as landfills, land 
treatment systems, etcetera, and EPA has not addressed this point in 
its preamble. As previously noted, combustion units are distinct from 
other types of TSDs due to the wide array of waste streams being fed to 
the unit, the complex chemical processes throughout the combustion 
unit, stack emissions comprised of a wide variety of compounds that are 
difficult to address, and the potential to impact receptors for several 
square miles due to stack dispersion. A further distinction is that EPA 
is seeking to rely on the MACT standards to eliminate national RCRA 
stack emissions standards under Sec.  1006(b). Unless EPA can 
affirmatively demonstrate that RCRA's protectiveness standards are met, 
the Agency cannot eliminate RCRA requirements. A number of 
uncertainties remain concerning the protectiveness of the MACT 
standards based on the uncertainties remaining in the supporting 
national risk assessment and comparative analysis, and the variability 
of site-specific factors from one facility to another. Permitting 
authorities' ability to resolve these uncertainties through the use of 
the SSRA, where appropriate, provides important support for the 
Agency's 1006(b) finding. Furthermore, as we have noted, under omnibus, 
to the extent permitting authorities believe there are problems with 
other types of TSDs, they can impose requirements and request 
additional information, including an SSRA in accordance with Sec.  
270.10(k). Also as previously noted, Part 264, subpart X specifically 
incorporates site-specific consideration of risk into its regulatory 
framework.
    Next, CKRC comments that EPA has a non-discretionary duty under CAA 
Sec.  112(f) to address and take care of any ``residual risk'' from 
MACT facilities in the future in any event. We discussed why we do not 
believe that the residual risk process should or can take the place of 
an SSRA under RCRA in subsection C. of this SSRA preamble, as well as 
in the 1999 rule preamble (64 FR 52843). In short, because the residual 
risk standards have not yet been established, permit writers cannot 
rely on this process in reaching current permitting decisions or in 
acting on currently pending permit applications.
2. Codification of EPA's Technical Guidance
    In response to our explanation in the proposal that risk assessment 
guidelines should be flexible and reflect current science, CKRC gave 
three comments: (1) Not a word of the current SSRA guidelines has been 
changed in 3 years; (2) it is easy to write regulations that have 
provisions that might be applied differently in different situations, 
and at least many basic, fundamental points can go in regulations, 
while some details can be in guidance--EPA writes regulations 
accompanied by ``fill in the small details'' guidance all the time; and 
(3) EPA seems to have no real problems with regulatory fixes anyway. In 
addition, CKRC provides several comments related to the previous three 
throughout their comment document, which are addressed below.
    None of these comments address the specific issue EPA raised, which 
is that, while it certainly is possible to codify our risk assessment 
guidance, for a variety of reasons, we disagree that it would be 
appropriate to issue these technical recommendations as a regulation. 
As we previously explained, risk assessment--especially multi-pathway, 
indirect exposure assessment--is a highly technical and evolving field. 
Any regulatory approach EPA might codify in this area is likely to 
become outdated, or at least artificially constraining, shortly after 
promulgation in ways that EPA cannot anticipate now. In support of 
this, we noted specific examples of problems we experienced in 
implementing the BIF regulations. See 69 FR 21330. Further, we 
explained that at the time of codification, BIF risk assessments were 
not intended to address indirect routes of exposure, thus making the 
parameters easier to implement. Today, however, risk assessments are 
more complex due to the necessary inclusion of multi-pathway and 
indirect exposure routes. Given the complexity of multi-pathway and 
indirect exposure assessments and the fact that risk science is 
continuously evolving, it would be difficult and again, overly 
constraining, to codify risk parameters today. We note as well, in this 
regard, that several commenters agreed that codification of EPA's risk 
assessment guidance would be too constraining for both the agency and 
the regulated community.
    We also believe that a guidance approach is consistent with the 
fact that permit authorities must make site-specific decisions whether 
to do risk assessments at all. We think that it makes little sense to 
allow this kind of flexibility regarding whether to do a risk 
assessment and for what purposes, while prescribing how one must be 
conducted if one is required. In fact, permitting authorities, in some 
cases, have developed their own guidance methodologies responsive to 
the specific needs associated with their facilities. For example, North 
Carolina, Texas, and New York have each developed their own risk 
assessment methodologies. Further, facilities that choose to conduct 
SSRAs themselves can choose alternative approaches in applying 
methodologies as well. We think this flexibility employed in the field 
supports our judgment that risk assessment methodologies should not be 
codified. CKRC's comments failed to address any of these issues.
    Turning to the remainder of CKRC's specific points--CKRC's 
assertion that the technical guidance has not been amended in the past 
three years is inaccurate. A revised HHRAP guidance, that has been 
amended to take into account the technical recommendations from both 
the public comments and peer review, is published in conjunction with 
this rule. In addition, as noted above, in some cases, permitting 
authorities have developed their own methodologies responsive to the 
specific needs associated with their facilities.
    With respect to CKRC's third point, the regulatory corrections made 
to the MACT rules were necessary either to fix an error or omission or 
to resolve potential legal issues. To codify technical tools and 
chemical information pertinent to the risk process simply is not 
prudent, as this information is continually changing and would almost 
always be out of date. Granted, when this information is presented in 
guidance, it can just as easily become outdated, however, facilities 
and risk assessors are free to use the most up-to-date air modeling 
tools and toxicity values available (i.e., they would not be bound to 
regulations requiring the use of obsolete tools and

[[Page 59513]]

information). We continue to believe that publishing our technical 
recommendations as regulation would remove much of the flexibility that 
is important in evaluating risk on a site-specific basis.
    CKRC discounts EPA's statement that codification of risk assessment 
is the exception arguing that ``Neither TSCA or CERCLA, however, 
specifically commands EPA to define the type of information necessary 
for a permit application through the rulemaking process as RCRA does. 
Moreover, the TSCA and CERCLA examples EPA cites are not analogous to 
the situation where a permit applicant can be denied a permit--or at 
least strung through months or years of tortuous and costly 
submissions, revision, and resubmission--to obtain a permit.''
    Even if TSCA and CERCLA were not considered to be analogous, that 
does not change EPA's fundamental rationale that codification of highly 
technical risk assessment guidance is not appropriate. EPA does not 
believe that RCRA Sec.  3005(b) requires EPA to codify an exhaustive 
list of every possible piece of information that might be required in a 
permit. To some extent, that is the reason for having a permit 
process--to allow site specific conditions to be taken into account. 
Nevertheless, EPA has revised part 270, pursuant to RCRA Sec.  3004(a) 
and Sec.  3005(b) to specifically provide that a risk assessment may be 
necessary, where there is reason to believe that the MACT standards may 
not be sufficiently protective. This was done wholly to address the 
petitioner's concern that the current regulations do not adequately 
provide notice that an SSRA might be necessary as part of a permit 
application. This provision, while it does not provide as much detail 
as the petitioner wishes, clearly ``defines the type of information 
necessary for a permit application.''
    CKRC complains that the Agency did not address in its proposed 
response the petitioner's discussion of the ``strong case law 
compelling the conclusion that `guidance' documents EPA has issued for 
conducting SSRAs must be subjected to notice-and-comment rulemaking.'' 
EPA has chosen not to respond to CKRC's legal interpretation because we 
believe that it is clear that the guidance documents do not impose 
mandatory requirements, and therefore need not be issued by notice and 
comment rulemaking. Nevertheless, EPA notes that in the proposal, the 
Agency explained that we were in the process of reviewing the guidance 
documents, and, to the extent we found language that could be construed 
as limiting discretion, we committed to revise the documents to make 
clear that they are non-binding. See 69 FR 21329. We specifically noted 
that CKRC indicated in its petition that, in its view, the documents 
contain language that could be construed as mandatory. While EPA does 
not necessarily agree, and believes that, in context, it is clear that 
the recommendations in the documents are discretionary, EPA nonetheless 
reviewed the documents to ensure that they are carefully drafted. 
Consequently, under the standards articulated in Appalachian Power Co. 
v. EPA, 208 F.3d 1015 (D.C. Cir. 2000) and subsequent case law, the 
final HHRAP guidance is truly guidance and does not require notice-and-
comment rulemaking. The HHRAP explains in great detail an acceptable 
process for performing and reporting on cost-effective, scientifically 
defensible risk assessments. It includes numerous recommended defaults, 
while at the same time provides the risk assessor or facility full 
opportunity to incorporate site-specific values in place of the 
defaults. The HHRAP offers numerous recommendations, but requires 
nothing. EPA has placed a copy of the final guidance document in the 
docket for today's action (see OAR-2004-0022).
    CKRC believes that EPA's technical guidance imposes information 
requirements upon the RCRA permit applicant that are not contained in 
any regulations and in fact exceed by orders of magnitude any 
information requirements contained in the part 270 regulations. We 
disagree that anything contained in HHRAP is ``required'' in any way. 
Moreover, to the extent any individual facility believes the 
information requested is inappropriate or unnecessary, they can 
challenge that as part of the permitting process.
    Lastly, CKRC argues that ``The procedures EPA has been using to 
issue and revise the SSRA guidance do not by any measure comply with 
the full panoply of procedures and protections offered by the APA 
process. Most critically, when EPA merely solicits comments on draft 
guidance documents, it has no duty to respond to comments and provide a 
rational basis and justification in defense of its choices in the face 
of comments. EPA is essentially running its entire SSRA program on the 
basis of ``draft'' guidance versions for which EPA has never to this 
day prepared any response to comments.'' As previously noted, EPA 
believes the final HHRAP is merely guidance and therefore, EPA is not 
required to proceed through notice and comment rulemaking pursuant to 
Sec.  553 of the APA. However, because we want the HHRAP guidance to be 
useful and clear, we have solicited public review and comment. As a 
result, it has been improved over the years by including revisions to 
the guidance based upon feedback from users of the guidance and from 
experience in the field. A response to comments document has been 
prepared and released along with the final HHRAP and final MACT rules, 
even though the Agency was not required to do so. More to the point, 
because it is only guidance, sources will have the opportunity to raise 
questions or comments on anything in the guidance as part of the 
permitting process and the permitting authority will be required to 
respond to those comments as part of the permitting process. See 40 CFR 
part 124. Sources will also have the right to challenge the responses 
or use of the guidance as part of the permitting process.
3. Codification of Criteria for Determining That Additional Risk-Based 
Permit Conditions or an SSRA Is Necessary
    CKRC argues that EPA's proposed regulatory changes should not be 
considered as a partial grant because EPA has not codified specific 
criteria in the proposed regulations for permit authorities to use to 
decide whether to require an SSRA; to set the risk levels that are 
deemed protective; or to otherwise provide any further definition as to 
what it means to protect human health and the environment.
    In its petition, CKRC requested that after we repeal the policy and 
guidance (per the first request), ``should EPA believe it can establish 
the need to require SSRAs in certain situations, CKRC urges EPA to 
undertake an appropriate notice and comment rulemaking process seeking 
to promulgate regulations establishing such requirements.'' As 
discussed at length in both the proposal (69 FR 21325-21327) and the 
preceding paragraphs, we believe that we have established certain 
circumstances where the MACT standards may not be protective and that 
an SSRA may be warranted, based on relevant site-specific factors 
associated with an individual combustion unit. Consequently, we are 
finalizing regulations that explicitly authorize permitting authorities 
to conduct or require an SSRA on a site-specific basis. This, in our 
view, grants the second of CKRC's requests. Our response directly 
addresses a number of CKRC's concerns: (1) Through a notice and comment 
rulemaking process, EPA has established circumstances in which an SSRA 
may be necessary; and (2) EPA's regulations will now explicitly

[[Page 59514]]

acknowledge that an SSRA might be necessary as part of the permitting 
process, thereby addressing the petitioner's concern that EPA's past 
approach of relying on RCRA's omnibus authority to implement this 
policy violates the requirements of RCRA Sec.  3005(b). And as 
discussed further below, EPA has codified criteria for permit 
authorities to use to determine whether to require an SSRA.
    While it does not provide exactly what CKRC requested, the 
regulated community has had a full opportunity to comment on the need 
for an SSRA both as part of the 1999 rulemaking and, again, as part of 
this rulemaking to adopt the provisions of Sec.  270.10(l), which 
contain an explicit reference to the potential need for an SSRA as part 
of the permitting process pursuant to RCRA Sec.  3004(a) and Sec.  
3005(b). As previously explained, Sec.  270.10(k) does not explicitly 
mention the potential for an SSRA to be required. Although the rule 
does not identify a priori that an SSRA will be required in an 
individual circumstance, but defers that determination to the 
permitting process, the final rule reflects EPA's findings that an SSRA 
is not anticipated to be necessary in every circumstance--only where 
site-specific conditions give the permit authority reason to believe 
that additional controls beyond those required pursuant to 40 CFR parts 
63, 264, 265, or 266 may be necessary to protect human health and the 
environment.
    CKRC argues that EPA's decision not to codify national criteria 
renders the regulation impermissibly vague, and therefore, ``in their 
view totally deficient as a legal matter.'' The petitioner argues that 
the rule is essentially ``a bootstrap attempt to avoid rulemaking 
requirements by establishing `rules' that give no more guidance or 
direction than general terms in the statute and in no way channel the 
decision maker's discretion or put the public on notice of anything.'' 
According to CKRC, this unbridled discretion is manifest in three ways: 
(1) No criteria explain how a permit writer is to decide whether to 
require an SSRA; need merely to conclude ``reason to believe''; (2) 
there are absolutely no limits on what type of information or 
assessments the permit writer may demand and the proposed reg. does not 
even hint at what type of information or assessments might be demanded; 
and (3) there is not a word of guidance or specification as to what it 
means to ``ensure protection of human health and the environment.'' The 
petitioner argues that as a consequence, the proposed Sec.  270.10(l) 
would be struck down as a ``standardless regulation.''
    EPA disagrees that the provisions at Sec.  270.10(l) are 
impermissibly vague, or otherwise inconsistent with the cases the 
petitioner cites. In the cited cases the courts found that the 
regulated entity bore the entire burden of determining how to comply 
with the challenged regulation in the complete absence of a government-
generated standard or guidance. See Maryland v. EPA, 530 F.2d 215, 220 
(4th Cir. 1975); South Terminal Corp v. EPA, 504 F.2d 646, 670 (1st 
Cir. 1974). This is entirely distinct from the regulations codified at 
Sec.  270.10(l).
    In Sec.  270.10(l) EPA identified the standard for when a risk 
assessment may be necessary: where the regulatory authority identifies 
factors or conditions at the facility that indicate that the MACT 
standards may not be sufficiently protective, and defers the 
articulation of the more precise requirement to the permitting process, 
where the onus falls on the permitting authority to identify the basis 
for its determination. Until the permitting authority provides this 
further guidance, the regulated entity incurs no obligation. The mere 
fact that specific factors or facility conditions that form the basis 
for the determination that an SSRA is warranted will be subsequently 
identified through the permitting process does not invalidate the 
regulation. See Ethyl Corp v. EPA, 306 F.3d 1144, 1149-1150 (D.C. Cir. 
2002).
    The regulation also identifies the categories of information that 
might be required for MACT EEE facilities: The information must be 
necessary to determine whether additional controls are needed to ensure 
protection of human health and the environment; it can include the 
information necessary to evaluate the potential risk from both direct 
and indirect exposure pathways; or it can include the information 
necessary to determine whether such an assessment is necessary. Here as 
well, EPA's reliance on the permitting process to provide further 
specification of the required information is not improper.
    Moreover, as discussed above in subsection C., in response to 
commenters' concerns, EPA has revised Sec.  270.10(l) to provide more 
detail, both with respect to the basis for the determination that an 
SSRA is necessary, and with respect to the type of information the 
permit authority might need. EPA has added language to remind permit 
authorities that the determination that the MACT standards may not be 
sufficiently protective is to be based only on factors relevant to the 
potential risk from the hazardous waste combustion unit at the site. 
EPA has also added language to Sec.  270.10(l) to identify guiding 
factors for permitting authorities to consult in determining whether 
the MACT will be sufficiently protective at an individual site. 
Although the list of guiding factors is not all-inclusive, they offer a 
structure for risk managers (as well as the regulated community) to use 
to frame the evaluation of whether a combustor's potential risk may or 
may not be acceptable.
    Finally, we note that, unlike the circumstances in the cited cases, 
Sec.  270.10 is promulgated in the context of an existing permitting 
regime. The regulatory standards at 40 CFR part 124 provide further 
structure for both the regulated community and the permit authority. 
For similar reasons, EPA disagrees that the cited cases compel the 
Agency to establish risk levels that are deemed protective, or to 
otherwise provide any further definition as to what it means to protect 
human health and the environment. We discussed at length throughout the 
proposal the reasons we believe it would not be appropriate to codify 
either an exclusive set of national criteria for determining that an 
SSRA (or additional risk-based permit conditions) would be necessary, 
or a uniform risk level. The decision to require an SSRA is inherently 
site specific, thus permitting authorities need to have the flexibility 
to evaluate a range of factors that can vary from facility to facility. 
See 69 FR 21328-21331. CKRC has neither presented new factual or policy 
reasons that would cause the Agency to reconsider the tentative 
decisions presented in the proposal, nor specifically addressed the 
issues underlying EPA's decision. Instead, the petitioner has merely 
reiterated the concerns presented in its petition and its general 
disagreement with EPA's decision.
    EPA also disagrees that its new regulatory structure grants permit 
writers unbridled discretion for many of the same reasons that EPA does 
not believe that Sec.  270.10(l) is impermissibly vague. As EPA has 
previously explained, the requirements at Part 124 continue to apply to 
actions taken to implement Sec.  270.10(l). Moreover, the language of 
Sec.  270.10(l) makes clear that the onus initially falls on the 
permitting authority to identify the basis for its conclusion that the 
MACT standards may not be sufficiently protective. As both part 124 et. 
seq., and EPA's preamble discussions make clear, facilities will 
continue to have the opportunity to comment on and challenge the 
determination. See Sec. Sec.  124.10, 124.11, and 124.19. The

[[Page 59515]]

regulatory structure adopted in Sec.  270.10(l) mirrors the structure 
Congress established in sections 3004 and 3005; although 3004 directs 
EPA to establish national standards, section 3005 recognizes that those 
standards will be applied on a case-by-case basis through the 
permitting process, to allow site-specific conditions to be taken into 
account, and to supplement those standards as necessary.
    EPA has also provided recommendations through guidance on how an 
SSRA can be conducted. Although the recommendations are not binding, 
they provide risk managers (as well as the facility) with a starting 
point from which to determine whether a combustor's potential risk may 
or may not be acceptable.
    CKRC argues that it appears that rather than following the 
statutory authorities and requirements to review and amend regulations 
every 3 years as necessary (RCRA Sec.  2002(b)), EPA decided to take 
the easy way out and impose, through non-rulemaking ``guidance'', 
massive, costly, and confusing requirements leaving unbridled 
discretion to its permit writers.
    We disagree that the Agency has attempted to avoid rulemaking in 
this context. EPA has conducted several rulemakings to amend our 
regulations. The first was in 1999, when we adopted revised emission 
standards under the authority of both Sec.  112(d) of the CAA and RCRA 
to more rigorously control toxic emissions from burning hazardous waste 
in incinerators, cement kilns, and lightweight aggregate kilns. See 64 
FR 52828. At the time, we noted that ``today's rule fulfills our 1993 
and 1994 public commitments to upgrade emission standards for hazardous 
waste combustors.'' We have continued to revise our regulations 
consistent with and based on the facts before the Agency, taking into 
account the arguments presented in CKRC's petition. As explained above, 
we believe that the facts do not support granting all of CKRC's 
requests. Rather we believe that the MACT standards will generally be 
protective, and that permit authorities should reach the decision to 
require an SSRA based on a variety of factors and concerns specific to 
their sites. In addition, as previously addressed, we believe that our 
risk assessment guidance should remain as guidance. Several other 
commenters agree that the guidance should not be codified.
    The petitioner argues that the regulation EPA has proposed to adopt 
is so vague, that it is essentially not a regulation, and that 
consequently, even if finalized, it would not be sufficient to comply 
with the requirement in RCRA Sec.  3005(b) to specify in regulations, 
the information necessary to obtain a permit. They compare the level of 
detail in Sec.  270.10(l) to the lengthy regulations (codified in 40 
CFR part 270) specifying in great detail the information required when 
one is submitting a RCRA permit application, arguing that ``these 
regulations cover 75 pages of fine print in Code of Federal 
Regulations,'' to demonstrate that this regulation would be 
insufficient under RCRA Sec.  3005(b). In further support of this 
argument, CKRC cites Ethyl Corporation v. EPA, 306 F.3d 1144 (D.C. Cir. 
2002).
    EPA disagrees that its regulations are in any way inconsistent with 
the decision in Ethyl Corp. At issue in that case was a regulation 
issued pursuant to section 206(d) of the CAA. Section 206(d) provides 
that EPA ``shall, by regulation, establish methods and procedures for 
making tests under this section.'' 42 U.S.C. 7525(d). The court found 
that ``with CAP 2000, [the challenged regulation] the EPA does not 
claim to have itself articulated even a vague durability test. Rather 
CAP 2000 requires that `the manufacturer shall propose a durability 
program' for EPA approval. 40 CFR 86.182301(a). It thus falls on the 
forbidden side of the line.'' Ethyl Corp., 306 F.3d at 323-324. The 
Court distinguished the challenged regulation from the situation in 
which an agency issues a ``vague'' regulation, and relies on subsequent 
proceedings to flesh out the specific details. And as the court 
explained, where ``Congress had not specified the level of specificity 
expected of the agency, we held that the agency was entitled to broad 
deference in picking the suitable level.'' 306 F.3d at 323 (citing 
American Trucking Associations v. DOT, 166 F.3d 374 (D.C. Cir. 1999) 
and New Mexico v. EPA, 114 F.3d 290 (D.C. Cir. 1997).
    In Sec.  270.10(l) EPA has articulated the standard for when a risk 
assessment may be necessary: where the regulatory authority has 
identified factors or conditions at the facility that indicate that the 
MACT standards may not be sufficiently protective. EPA has also adopted 
a list of factors on which permit writers are to rely in reaching this 
determination. EPA has also identified the categories of information 
that might be required for MACT EEE facilities: The information must be 
necessary to determine whether additional controls are needed to ensure 
protection of human health and the environment; it can include the 
information necessary to evaluate the potential risk from both direct 
and indirect exposure pathways; or it can include the information 
necessary to determine whether such an assessment is necessary. While 
it does not provide as much detail as the petitioner wishes, this 
provision unquestionably ``defines the type of information necessary 
for a permit application.''
    Thus, the issue turns on the level of specificity that RCRA Sec.  
3005(b) requires, and EPA does not believe that RCRA Sec.  3005(b) 
requires EPA to publish a list of every possible piece of information 
that might be required in a permit. Section 3005(b) merely establishes 
a broad directive that ``each application for a permit under this 
section shall contain such information as may be required under 
regulations promulgated by the Administrator,'' and that it shall 
include the information contained in subsections (1) and (2), leaving 
to EPA's discretion to determine the level of specificity at which to 
promulgate regulations. To some extent, this reflects the reason for 
having a permit process--to allow site specific conditions to be taken 
into account. The regulatory structure adopted in Sec.  270.10 mirrors 
the structure Congress established in RCRA Sec.  3004 and Sec.  3005. 
Despite the petitioner's comparison to the length of part 270, the 
length of these provisions are not indicative of any determination of 
the precise level of detail that Sec.  3005(b) requires, but reflects 
the fact that EPA has adopted requirements specific to individual types 
of units. Moreover, notwithstanding the petitioner's characterization, 
the language at Sec.  270.10(l) is comparable to many other provisions 
in 40 CFR part 270. See, for example: Sec. Sec.  270.14(b)(8); 
270.16(h)(1)-(2); 270.22(a)(6)(i)(C); 270.22(c).
    Lastly, CKRC argues that the proposed regulation is particularly 
problematic, because it extends beyond ``information'' that may already 
exist. CKRC says that it is one thing to demand that a party go out and 
gather existing information, but another thing to demand that an 
applicant conduct ``assessments.'' Moreover, nothing in the regulations 
prohibits a permit authority from demanding revised assessments, and 
even more revised assessments. We agree that permit authorities have 
the authority to require facilities to provide additional information 
beyond that which already exists. However, based on feedback from EPA 
Regional permit writers, SSRAs generally represent a one-time cost. We 
do not expect that facilities that have conducted risk assessments will 
have to repeat them. As discussed in the 1999 final rule preamble, 
changes to comply with the MACT standards should not cause an increase 
in risk for the vast majority of facilities given that the changes, in 
all

[[Page 59516]]

probability, will be the addition of pollution control equipment or a 
reduction in the hazardous waste being burned (see 64 FR 52842). 
Instances where a facility may need to repeat a risk assessment would 
be related to changes in conditions that would likely lead to increased 
risk.\242\ In such situations, we would anticipate that the risk 
assessment would not have to be entirely redone. It may be as limited 
as collecting relevant new data for comparison purposes, leading to a 
decision not to repeat any portion of a risk assessment. Or, it may be 
more inclusive such that modifications would be made to specific inputs 
to or aspects of the risk assessment using data from a previous risk 
assessment, risk burn or comprehensive performance test. As discussed 
in subsection B., we have added a new regulatory provision to indicate 
a previously conducted risk assessment would be relevant in evaluating 
changes in conditions that may lead to increased risk. The factor reads 
as follows: ``Adequacy of any previously conducted risk assessment, 
given any subsequent changes in conditions likely to affect risk.''
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    \242\ For example, hazardous waste burning cement kilns that 
previously monitored hydrocarbons in the main stack may elect to 
install a mid-kiln sampling port for carbon monoxide or hydrocarbon 
monitoring to avoid restrictions on hydrocarbon levels in the main 
stack. Thus, their hydrocarbon emissions may increase. (64 FR 52843, 
footnote 29.) Another example would be if the only change at a 
facility relates to the exposed population; what was acceptable in a 
previous risk assessment may not be any longer.
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4. EPA's Cost Estimates for SSRAs
    CKRC raised several objections to our cost estimates for conducting 
an SSRA, and provided higher cost estimates ($200K to $1M, with upper 
bound of $1.3M). We suggested in the proposal, that the higher cost 
figures provided by CKRC were likely incurred prior to the 1998 release 
of the Human Health Risk Assessment Protocol (HHRAP) guidance document. 
We believe our lower cost estimates can be attributed to the fact that 
we based them on the conduct of future SSRAs that will benefit from 
substantially better guidance and commercially available software.
    Multiple issues regarding the cost information we provided in the 
proposal are raised by CKRC. The first of five issues is that CKRC 
believes that EPA's methods for calculating costs associated with 
future SSRAs do not include data gathering costs, QA/QC, third party 
consultants in addition to risk assessors and plant personnel time to 
coordinate and review SSRA efforts and collect facility data. We 
disagree with this statement in part; the estimates developed by the 
Agency do include data gathering costs, QA/QC, and third-party 
consultants. (Refer to the proposed rule's support document entitled: 
Preliminary Cost Assessment for Site Specific Risk Assessment, November 
2003, Docket <greek-i> OAR-2004-0022; and the Assessment of the 
Potential Costs, Benefits, and Other Impacts of the Hazardous Waste 
Combustion MACT Replacement Standards--Final Rule, October 12, 2005, 
for a description of how the estimates were arrived at.) However, we 
agree with CKRC that the method used to develop SSRA costs does not 
capture facility time associated with data collection and management 
related to the SSRA. Consequently, we have adjusted our SSRA cost 
estimates to account for these activities by incorporating costs 
associated with time needed for facility data collection and management 
efforts associated with the SSRA, and will assume that engineering 
staff are required to perform these tasks.
    The second issue concerns the extent to which cement kiln SSRAs are 
consistent with EPA's ``normal'' assumptions. We do not question the 
accuracy of the costs submitted by CKRC. However, it is not clear that 
the costs submitted by CKRC represent typical future costs for SSRA 
implementation at all facilities in the universe. Certain of the CKRC 
cost estimates (e.g., those submitted by Ash Grove and Holcim) reflect 
implementation of SSRAs over a number of years in the 1990s, while SSRA 
implementation was in its early stages. In other cases (e.g., estimates 
provided by Solite) costs appear to be consistent with EPA estimates. 
While we do not dispute the accuracy of these costs, earlier costs are 
likely to reflect the deliberative process common with early SSRAs.
    For the third issue, CKRC's points out that EPA's estimate of 20 
percent additional cost for adding a risk burn during a trial burn may 
be low; CKRC asserts that additional test costs can add up to 40 
percent depending on the circumstances. We agree with this and have 
adjusted the range of total SSRA costs as necessary to assure that a 
range of additional test costs for separate risk burns (20 to 40 
percent incremental cost) are included. For revised figures, see 
background document, Assessment of the Potential Costs, Benefits, and 
Other Impacts of the Hazardous Waste Combustion MACT Replacement 
Standards--Final Rule, October 12, 2005.
    CKRC's fourth issue is that EPA does not appear to include more 
than evaluations of stack emissions in its estimates of SSRA costs. We 
disagree with this comment. The estimates of SSRA costs developed by 
the Agency reflect total contractor costs for performing an SSRA at a 
facility under different sets of conditions, and are not limited to 
stack emissions.
    In the fifth cost-related issue, CKRC asserts that EPA's average 
estimates might be reasonable if the SSRA process were limited to the 
submission and acceptance of one SSRA effort. CKRC contends, however, 
that its members' experiences with SSRAs have involved coordination 
with state and regional offices and multiple revisions and submissions. 
Again, we do not question the experiences and costs of specific 
facilities. However, we anticipate that the 2003 Memorandum, Use of the 
Site-Specific Risk Assessment Policy and Guidance for Hazardous Waste 
Combustion Facilities, and the Human Health Risk Assessment Protocol 
for Hazardous Waste Combustion Facilities guidance, which is finalized 
and released in conjunction with today's rule, will provide facilities 
and regulators with a clearer understanding of SSRA policy and guidance 
and will support a more efficient SSRA process. EPA's future SSRA cost 
estimates are based on current or recent cost data from multiple 
practitioners, and likely reflect a more efficient process than that 
experienced by some CKRC members in the 1990s.

X. Permitting

    As discussed in the proposal, we believe that the permitting 
approach we adopted in the 1999 final rule is still the most 
appropriate means to avoid duplication to the extent practicable and to 
streamline requirements. Thus, both Phase 1 and Phase 2 sources will 
comply with their RCRA emission limits and operating requirements until 
they demonstrate compliance with the MACT standards by conducting a 
comprehensive performance test (CPT), submitting a Notification of 
Compliance (NOC) documenting compliance to the Administrator or 
delegated state, and then requesting to have their RCRA permits 
modified to remove the duplicative RCRA requirements (unless a sunset 
clause had been added previously that inactivates specified 
requirements upon compliance with MACT).\243\ Ultimately, the MACT air 
emissions and related operating requirements will reside in the CAA 
Title V permit, while all other aspects

[[Page 59517]]

of the combustion unit and the facility (e.g., corrective action, 
general facility standards, other combustor specific concerns such as 
material handling, risk-based emission limits and operating 
requirements, and other hazardous waste management units) will remain 
in the RCRA permit. A new pictorial timeline has been provided to 
highlight milestones of the MACT compliance process. See figure 1 at 
the end of this section.
---------------------------------------------------------------------------

    \243\ Although we expect that the vast majority of Phase 1 
sources will have had their RCRA permits modified by the time this 
rule is promulgated, we acknowledge that there may be a few permits 
yet to be modified.
---------------------------------------------------------------------------

A. What is the Statutory Authority for the RCRA Requirements Discussed 
in this Section?

    EPA is finalizing amendments to modify RCRA permits in today's rule 
pursuant to sections 1006(b), 2002, 3004, 3005 and 7004(b) of RCRA. 42 
U.S.C. Sec. Sec.  6905(b), 6912, 6924, 6905, and 6074. Our approach is 
likewise consistent with section 112(n)(7) of the Clean Air Act which 
indicates that EPA should strive to harmonize requirements under 
section 112 and RCRA requirements for hazardous waste combustion 
sources. With respect to the regulatory framework that is discussed in 
this section, we are finalizing the process to eliminate the existing 
RCRA stack emissions national standards for hazardous air pollutant for 
Phase 2 sources as we had done for Phase 1 sources in the 1999 final 
rule. That is, after submittal of the NOC established by today's rule 
and, where applicable, once RCRA permit modifications are completed at 
individual facilities, RCRA national stack emission standards will no 
longer apply to these hazardous waste combustors (unless risk-based 
permit conditions are determined necessary).
    We originally issued emission standards under the authority of 
section 3004(a) and (q) of RCRA, which calls for EPA to promulgate 
standards ``as may be necessary to protect human health and the 
environment.'' We believe that the final MACT standards are generally 
protective of human health and the environment, and that separate RCRA 
emission standards are not needed to protect human health and the 
environment. See Part Seven, How Does the Final Rule Meet the RCRA 
Protectiveness Mandate? for a discussion of this topic. RCRA section 
1006(b) directs EPA to integrate the provisions of RCRA for purposes of 
administration and enforcement and to avoid duplication, to the maximum 
extent practicable, with the appropriate provisions of the Clean Air 
Act (and other federal statutes). This integration must be done in a 
way that is consistent with the goals and policies of these statutes. 
Therefore, based on its findings regarding the protectiveness of the 
MACT standards, and pursuant to section 1006(b), EPA is generally 
eliminating the existing RCRA stack emission standards to avoid 
duplication with the new MACT standards. The amendments made today to 
allow new combustion units to comply with the MACT standards upon 
start-up, versus the RCRA stack emissions national standards, are based 
on the principle of avoiding duplication between programs.
    We are not stating that RCRA permit conditions to control emissions 
from these sources will never be necessary, only that the national RCRA 
standards appear to be unnecessary. Under the authority of RCRA's 
``omnibus'' clause section 3005(c)(3); (see Sec. Sec.  270.32(b)(2) and 
(b)(3)), RCRA permit authorities may impose additional terms and 
conditions on a site-specific basis as may be necessary to protect 
human health and the environment. Thus, if MACT standards are not 
protective in an individual instance, RCRA permit writers will 
establish permit limits that are protective.
    In RCRA, Congress gave EPA broad authority to provide for public 
participation in the RCRA permitting process. Section 7004(b) of RCRA 
requires EPA to provide for, encourage and assist public participation 
in the development, revision, implementation, and enforcement of any 
regulation, guideline, information, or program under the Act.

B. Did Commenters Express any Concerns Regarding the Current Permitting 
Requirements?

    Generally speaking, commenters favor maintaining the permitting 
approach and requirements referred to above. This approach was 
finalized in the 1999 rule and has been implemented, and in a few cases 
is currently being implemented, for Phase 1 sources complying with the 
Interim Standards Rule. However, several commenters raised similar 
concerns regarding certain aspects of the transition process from RCRA 
to MACT and Title V permitting.
1. Removal of Duplicative RCRA Permit Conditions
    One comment is in regard to Phase 1 sources that have been fully 
transitioned (i.e., have had duplicative RCRA permit conditions and 
requirements removed or that have been ``sunsetted'') to compliance 
with the Interim Standards that may need to make upgrades to comply 
with the revised Phase 1 MACT Standards. The concern is that Phase 1 
sources needing to make upgrades for MACT should be able to do so 
without a RCRA permit modification (unless risk-based conditions are 
present). We agree with the commenters that as long as the technology 
upgrades (e.g., equipment changes to upgrade air pollution control 
equipment) do not affect any remaining conditions in the RCRA permit, 
the regulations do not require a permit modification. For those Phase 1 
sources that need to make upgrades to comply with the revised 
standards, they should address the specific upgrades in their draft 
Notification of Intent to Comply (NIC) and during the informal NIC 
public meeting so that the regulatory authority and public are aware of 
the source's activities and plans for compliance. We encourage early 
communication between the source and the RCRA permit writer to ensure a 
common understanding of whether a RCRA permit modification will be 
needed.
    Additionally, Phase 1 sources must comply with the provisions of 
Sec.  63.1206(b)(5) for changes in facility design. We do not 
anticipate that upgrades made to comply with the Replacement Standards 
will adversely affect a source's compliance with the Interim Standards. 
Therefore, consistent with Sec.  63.1206(b)(5)(ii), sources must 
document the change in their operating record, revise their NOC and 
resubmit it to the permitting authority (per Sec.  63.9(h)), and, as 
necessary, revise their start-up, shutdown, and malfunction plan.\244\
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    \244\ The requirements in Sec.  63.1206(b)(5)(ii) call for 
sources to revise (as necessary) the performance test plan, DOC, 
NOC, and start-up, shutdown, and malfunction plan. For sources 
complying with the Interim Standards, it is not necessary to revise 
the performance test plan or the DOC, since they were developed in 
preparation for compliance with the Interim Standards.
---------------------------------------------------------------------------

    Several commenters felt that we should re-emphasize the importance 
of removing duplicative RCRA permit conditions and requirements. We 
agree with the commenters that this is an important action for 
regulatory agencies. In addition to comments received, we also have 
learned through the implementation process for the Interim Standards, 
that some state agencies are not removing duplicative requirements from 
the RCRA permit. We have clearly stated in several preambles and 
guidance documents that we believe it is appropriate to retain only the 
RCRA risk-based conditions that are more stringent than the applicable 
MACT limits (i.e., if the RCRA condition has been determined to limit 
risk to an acceptable level and is necessary to protect human health 
and the environment) in the RCRA permit after

[[Page 59518]]

compliance with MACT.\245\ However, we also acknowledge that in certain 
cases it may not be clear which compliance requirement is more 
stringent. For example, standards under MACT are expressed as 
concentration based limits (micrograms/dry standard cubic meter) while 
certain RCRA standards are expressed as mass emission rate limits 
(grams/second). Also, averaging times between the two programs differ: 
MACT requires hourly rolling averages whereas RCRA requires 
instantaneous values. This is an unfortunate consequence of moving 
compliance from a risk-based program to a technology-based program. 
Because we cannot definitively say when a RCRA requirement is more 
stringent than a MACT requirement and consistently apply it to all 
sources, we are relying on sources and permitting agencies to work 
together to determine which requirement is more stringent. If the MACT 
requirement is determined to be more stringent, the permitting agency 
can remove the requirement from the RCRA permit.
---------------------------------------------------------------------------

    \245\ As an example, a RCRA permit could specify a higher 
minimum operating temperature than what is necessary for the 
facility to achieve compliance with MACT. The lower minimum 
operating temperature under MACT may be sufficient, unless the RCRA 
permit authority determines that the higher RCRA temperature is 
necessary to limit risk to an acceptable level for that facility. 
There should be a connection between the RCRA limit and protection 
of human health and the environment when retaining a RCRA limit.
---------------------------------------------------------------------------

    In adopting a permitting approach to place the MACT air emissions 
and related operating requirements in the CAA Title V permit and to 
keep all other aspects of the combustion unit and the facility in the 
RCRA permit, our intent was and still is, to minimize duplication to 
the extent practicable and to eliminate the potential for dual 
enforcement. We view it as an unnecessary duplication of effort between 
programs as well as an unnecessary expenditure of resources and costs 
for both facilities and regulatory authorities to maintain a RCRA 
permit and a Title V permit that contain duplicative requirements, when 
there are viable mechanisms (i.e., Class 1 modification procedure at 
270.42 Appendix I, section A.8, or Class 2 or 3 if a state has not 
adopted the Class 1 procedure) in place to avoid doing so.
    Nevertheless, we believe that states should have the flexibility to 
decide how they will allocate their resources, which is why we did not 
include a single transition approach for implementing agencies to 
follow in the 1999 rule or in today's rule. So, in such cases where a 
state agency chooses not to adopt the transition language (i.e. the 
Class 1 modification procedure at 270.42 Appendix I, section A.8) into 
their state requirements (e.g., because the state's procedures are 
broader in scope or more stringent than the federal requirements) or is 
unable to reach an agreement between its RCRA and air programs 
regarding which standards are more stringent, the Title V permitting 
authority should document these issues, including any continuing RCRA 
permit requirements, in the title V permit's statement of basis (40 CFR 
Sec. Sec.  70.7(a)(5) and 71.7(a)(5)). This will help to ensure that 
the source is clear regarding its compliance obligations, which is a 
main goal of the Title V program. Further, for purposes of 
clarification and as a matter of courtesy, we urge regulatory 
authorities that choose to impose dual compliance requirements, to also 
provide a written justification to the source explaining the reasons 
for their decisions.
2. Transition of Interim Status Phase 2 Units From RCRA to CAA Permits
    In response to our discussion in the proposal regarding RCRA 
permitting for interim status Phase 2 units (69 FR 21324), two 
commenters suggest that EPA establish policy and/or regulation that 
discourage further RCRA permitting work for interim status Phase 2 
sources. Their comments are directed our statement in the proposal that 
the RCRA combustion permitting procedures in 40 CFR part 270 also 
continue to apply until you demonstrate compliance. As noted in this 
statement, we intended for Phase 2 sources to continue to be subject to 
RCRA permitting requirements for air emissions standards and related 
operating parameters, including trial burn planning and testing, until 
they have demonstrated compliance with the MACT standards by conducting 
a comprehensive performance test and submitting an NOC to the Agency. 
However, we also provided several factors that should be taken into 
consideration when determining whether to proceed with the RCRA permit 
process such as: the facility's permit status at the time the MACT rule 
becomes final, the facility's anticipated schedule for MACT compliance, 
the priorities and schedule of the regulatory agency, and the level of 
environmental concern at a given site (69 FR 21324).
    To support their position, the commenters noted that time and 
resources would be conserved and duplicative and overlapping activities 
could be minimized if Phase 2 sources were permitted solely via Title 
V. Also, they argued that it would avoid expending resources to modify 
the RCRA permit once the source has demonstrated compliance with MACT. 
We agree with commenters that every effort should be made to conserve 
resources and avoid duplication to the extent possible. However, we do 
not believe it is appropriate to establish policy or regulation that 
permitting authorities must suspend the RCRA permit process (whether it 
pertains to interim status or renewals), especially in cases where 
considerable time and effort has been invested and the permit is close 
to final issuance. As before, we strongly encourage sources and 
regulatory authorities to work together to establish an approach that 
will provide for the most practical transition. For example, we 
strongly recommend that sunset provisions be included in a permit that 
will be issued well in advance of compliance with MACT to avoid 
duplication and a later modification to remove the duplicative RCRA 
conditions. Also, it would make more sense to transition a source to 
MACT compliance prior to issuing the RCRA permit if it will comply with 
MACT early.
3. Transition From Compliance With the Interim Standards to the 
Replacement Standards
    A specific question that has been raised relates to the applicable 
standards and operating parameters that the source must comply with 
during the period between the rule's effective date for the Phase 1 
Replacement Standards and submission of their new NOC. Upon the 
publication date of the rule, the Replacement Standards (and Phase 2 
Standards) will become effective and sources will have 3 years to come 
into compliance. During this 3-year period, Phase I sources' existing 
title V permits will either be reopened to include the Replacement 
Standards, or the permitting authority will have incorporated the 
Replacement Standards during permit renewal. In this example, a Phase 1 
source's Title V permit has been reopened, revised, or renewed and 
includes the Replacement Standards, the compliance date has not yet 
passed, no new documentation of compliance (DOC) for the replacement 
standards has been included in the operating record, and the source has 
not yet conducted a comprehensive performance test and submitted a new 
NOC (therefore it still has an NOC containing the operating parameters 
for compliance with the Interim Standards).
    In the above scenario, the question asked is whether the source 
should comply with the Interim Standards in the current NOC or the 
Replacement Standards in the Title V permit. The

[[Page 59519]]

source should comply with the Interim Standards until the compliance 
date of the Replacement Standards. Although the Title V permit now 
includes the Replacement Standards, the permit will also include the 
Replacement Standards' future compliance date. With regard to the 
transition from the Interim Standards NOC to the Replacement Standards 
DOC, we are revising the regulations at Sec.  63.1211(c) to render the 
NOC, which documented compliance with the Interim Standards, 
inapplicable upon inclusion of the DOC for the Replacement Standards in 
the operating record by the compliance date. Thus, the source will not 
be placed in a situation where it must continue to ensure compliance 
with the operating parameters established in the NOC for the Interim 
Standards, while seeking to comply with the Replacement Standards and 
operating parameters in its DOC. Although it can be assumed that the 
source would still be able to comply with its Interim Standard-based 
NOC because the Replacement Standards are the same as or more stringent 
than the Interim Standards, we believe that the revision to render the 
previous NOC inapplicable provides a clearer and more sensible 
approach.
4. Changes to Title V Permits
    Both the Replacement Standards and the Phase 2 Standards will 
necessitate permit reopenings or revisions to some existing title V 
permits; other permits will incorporate the requirements upon renewal. 
40 CFR Sec. Sec.  70.7 and 71.7 include the requirements for Title V 
permit revisions, reopenings, and renewals. Also, approved Title V 
permitting authorities may have additional requirements. Please refer 
to the appropriate permitting authority and its individual Title V 
permits program to determine the necessary requirements and procedures.
    With respect to incorporating minor revisions into the Title V 
permit, one commenter had asked, for example, whether revisions made to 
the NOC to reflect minor operating changes could be incorporated into 
the permit by reference rather than through the reopening procedures. 
Determining the appropriate Title V permit reopening or revision 
requirements is based on the nature of the change and the source 
specific permit terms and conditions, and is therefore difficult to 
generalize. We recommend that sources work with their Title V permit 
authorities to determine the appropriate requirements and procedures 
that are applicable to any specific situation. However, we would like 
to note that, when incorporating requirements by reference into the 
Title V permit is appropriate, this does not necessarily obviate the 
need for permit revisions if the material incorporated by reference is 
subsequently revised. For more information on incorporation by 
reference, please refer to the Office of Air Quality Planning and 
Standards' ``White Paper Number 2 for Improved Implementation of the 
Part 70 Operating Permits Program'' (March 5, 1996), Section II.E.2.c. 
This paper can be found at: http://www.epa.gov/ttn/oarpg/t5/memoranda/wtppr-2.pdf.

C. Are There Any Changes to the Proposed Class 1 Permit Modification 
Procedure?

    In the NPRM, we proposed a new Class 1, with prior Agency approval, 
permit modification procedure to help further minimize potential 
conflicts between the RCRA permit requirements and MACT requirements. 
See 69 FR 21384 and proposed Sec.  270.42(k). During implementation of 
the Interim Standards for Phase 1 sources, it became evident that there 
are two significant instances where RCRA permit limits may overlap with 
MACT requirements: during initial (and future) performance testing and 
during the period between placement of the documentation of compliance 
(DOC) in the operating record and the final modification of the RCRA 
permit after receipt of the NOC. We discussed several existing 
approaches (e.g., a class 2 or 3 modification, request for approval 
submitted via the RCRA trial burn plan or coordinated MACT/RCRA test 
plan, or through a temporary authorization) for addressing these 
instances, noting that none provided an optimal solution.
    All commenters agreed that the new Class 1 modification procedure 
is the appropriate and most efficient method to enable specific RCRA 
permit conditions to be waived during instances of overlap referred to 
above. However, a few commenters were concerned with the requirements 
in proposed Sec.  270.42(k)(2)(ii) and (k)(3), that require sources to 
submit their permit modification request upon approval of the test plan 
and the requirement for the Director to approve or deny the request 
within 30 days, or within 60 days with an extension. This timeframe is 
feasible only for those sources that have received approval of their 
test plans at least 60 days prior to their scheduled date for 
commencing their performance test. We acknowledged the potential 
impracticality of this requirement in the proposal, but at the time 
believed that few sources, if any, would conduct their performance 
tests without an approved test plan. While this still may be true, we 
have learned that sources who received extensions for testing (so that 
they would have an approved plan), typically commenced their test 
shortly after approval. Consequently, this still would not allow enough 
time to review and approve the permit modification before the test 
begins. Thus, the new Class 1 modification would be of no benefit to 
facilities that conduct their tests without an approved test plan, or 
to facilities that received extensions and need to begin their tests 
upon or shortly after approval of the test plan. Also, we found one 
other circumstance where the timeframes could be problematic: If a 
permitting agency has allowed sources to begin pretesting/testing upon 
approval of the test plan. Again, a source would not be able to have 
RCRA permit requirements waived in time to begin its test.
    We agree with commenters that the proposed requirements in 
270.42(k)(2)(ii) and (iii) do not provide any flexibility to waive RCRA 
permit limits for sources that (1) do not have an approved test plan 
but choose to conduct their test; (2) are granted an extension to their 
test date because they do not yet have an approved test plan; and (3) 
may begin testing upon approval of their test plans. Our original 
intent to require prior Agency approval for the new Class 1 permit 
modification procedure was to ensure that the proposed test conditions 
would be sufficiently protective when specific RCRA requirements are 
waived and that a source has met the regulatory requirements for 
performance test plans. We still believe that review and approval is an 
important step; however, we also believe it should not be a barrier and 
therefore, should occur in advance of a source commencing its 
performance test. As a result, we have revised the proposed regulatory 
language in 270.42(k)(2)(i) to specify that sources submit their permit 
modification requests with their test plans, to allow potentially up to 
one year for approval (i.e., the performance test plan is due one year 
before the test is to begin). Also, so that approval does not impede 
the commencement of the performance test, we have revised the proposed 
language in 270.42(k)(2)(ii) so that the Director can choose whether to 
issue approval of the permit modification request contingent upon 
approval of the performance test plan.\246\ In that respect,

[[Page 59520]]

the RCRA permit authority would continue to have an extra measure of 
assurance in circumstances that may demand it.
---------------------------------------------------------------------------

    \246\ In all likelihood, we anticipate that the RCRA permit 
authority will have reviewed the modification request along with the 
test plans, worked with its Air counterparts and the source to 
resolve any concerns, and have prepared the permit modification 
approval prior to issuance of the test plan approval.
---------------------------------------------------------------------------

D. What Permitting Approach Is EPA Finalizing for New Units?

1. Why Did EPA Propose a Separate Permitting Approach?
    As discussed in the proposal, the current RCRA regulations at 
Sec. Sec.  264.340, 265.340, 266.100, 270.19, 270.22, 270.62, and 
270.66 do not address how or when new combustion units will comply with 
the MACT standards. Consequently, the part 270 regulations imply that a 
new unit must obtain a complete RCRA permit before it can demonstrate 
compliance with the MACT standards. It was never our intent for new 
units to develop a trial burn plan and provide suggested conditions for 
the various phases of operation in the RCRA permit application, given 
that these conditions will become inactive or need to be removed from 
their permits upon demonstrating compliance with MACT. To rectify our 
previous omission, we suggested several options that would allow units 
newly entering the RCRA permit process \247\ (and that will comply with 
the Subpart EEE requirement upon start-up) to forego certain RCRA 
permit requirements and performance standards. In developing the 
options that would enable new units to forego certain RCRA 
requirements, we noted the importance of public participation 
opportunities under the MACT/CAA framework equivalent to those provided 
under the RCRA framework. Thus, each option was constructed in such a 
way that would streamline the RCRA requirements, but continue to 
provide early and frequent public participation commensurate with the 
requirements of the RCRA Expanded Public Participation Rule (60 FR 
63417, December 11, 1995).
---------------------------------------------------------------------------

    \247\ Units ``newly'' entering the RCRA permit process refers to 
a newly constructed facility, thus newly constructed hazardous waste 
combustion unit; an existing facility that constructs a new unit; or 
an existing facility that converts a non-hazardous fuel combustion 
unit to a hazardous waste fuel combustion unit.
---------------------------------------------------------------------------

2. What Options Did EPA Propose for Permitting New Units?
    In our preferred approach, we proposed that new units not be 
required to develop a trial burn plan and provide suggested conditions 
for the various phases of operation in their RCRA permit application. 
Instead, new units would only be required to address the remaining RCRA 
activities at the facility in their permit application (or modification 
request) including corrective action, general facility standards, other 
combustor specific concerns such as materials handling, risk-based 
emission limits and operating requirements, and other hazardous waste 
management units. While this approach appears to be ideal from the 
standpoint of reducing the regulatory burden to sources and RCRA permit 
authorities, we noted that even though a new unit will be required to 
meet the RCRA public participation requirements as part of the permit 
application process, the operations and emission information specific 
to the combustor would no longer be provided. Thus, we focused on 
certain compliance activities under the MACT/CAA framework (i.e., the 
Notification of Intent to Comply requirements) that would allow for 
combustor-specific information to be made available to the public as it 
would have been under the full RCRA permit process.
    Regarding the three additional approaches or ``options'', each 
considered a different point in the RCRA permit process where a new 
unit could ``transition'' to compliance with the MACT standards (see 69 
FR 21319). Under the first option, a new unit could transition to MACT 
compliance after it had submitted its RCRA Part B application. The Part 
B however, would not include the trial burn plan information. The new 
unit would only be required to discuss the compliance activities 
related to the combustor as part of the RCRA informal public meeting. 
In the second option, we proposed that a new unit would transition 
after its RCRA permit has been issued. Here, the new unit would be 
required to develop a trial burn plan which provided its proposed 
operations and emissions information and to discuss its compliance 
activities via the RCRA informal public meeting. Then, a permit would 
be issued, but it would not contain operating and emissions 
requirements in order to avoid a future modification to remove them. 
For the third option, the transition point would have been after the 
new unit places the DOC in its operating record, which is the 
compliance point for MACT. This option is more inclusive than the 
second because it requires the new unit to have a draft permit that 
covers the construction and shakedown period.
3. Which Option Is EPA Finalizing?
    For today's final rule, we are adopting our preferred, proposed 
approach: new units will not be required to follow the full RCRA 
permitting process for establishing combustor operations and emissions. 
Thus, new units are not subject to the combustor-specific RCRA permit 
requirements and performance standards (i.e., to develop a trial burn 
plan, provide suggested conditions for the various phases of operation 
in their permit application, and subsequently operate under those 
conditions). However, because these units remain hazardous waste 
treatment units, they are still required to obtain a RCRA permit, or to 
modify an existing RCRA permit to include a new unit, prior to 
construction. They need only address the remaining hazardous waste 
management activities at the facility in their permit application (or 
modification request) including corrective action, general facility 
standards, other combustor specific concerns such as materials 
handling, risk-based emission limits and operating requirements, and 
other hazardous waste management units. As we noted in the previous 
section and will discuss again more thoroughly in the next section, we 
are relying on the NIC process to provide the public with the 
combustor-specific information that previously would have been provided 
under the full RCRA permit process.
    Almost all commenters supported our preferred approach to not 
require that new units complete the full RCRA permit process and to 
rely on the NIC requirements and the MACT/CAA framework to provide a 
level of public participation that is commensurate with the 
requirements under RCRA. Commenters generally agreed that our preferred 
approach achieves this goal while streamlining the RCRA permit process 
for new units. One commenter felt that the Title V and New Source 
Review programs (NSR) provide sufficient requirements to regulate new 
combustion units. We disagree that either or both of those programs 
fully address the hazardous waste and public participation components 
commensurate with that provided by the approach we are finalizing 
today. For instance, a unit may be constructed and operating before a 
Title V permit is issued, which directly conflicts with RCRA's early 
public participation requirements. Also, in some instances, public 
participation may not be a required component of state issued NSR 
permits (see footnote regarding public participation and SIPs below). 
However, we do believe that the NSR program will play an important role 
regarding the exchange of information, as we will discuss in the 
section below. With respect to the remaining three options presented in 
the proposal (69 FR 21319-

[[Page 59521]]

21320) that suggested a transitional approach (i.e., each option 
explored progressive points in the RCRA permit process where facilities 
could transfer over to MACT without fully completing the RCRA process), 
nearly all commenters were in agreement that they would require more 
work to implement than is necessary and consequently oppose them.
4. How Will Permitting for New Units Work?
    In the proposed rule, we created an approach that utilizes the NIC 
requirements and the MACT/CAA framework with the intent of ensuring 
that the requirements of the RCRA Expanded Public Participation Rule 
would continue to be fulfilled. The four requirements for public 
participation as they relate to hazardous waste combustion units are: 
(1) Permit applicants must hold an informal public meeting before 
applying for a permit; (2) permit agencies must announce the submission 
of a permit application which will tell community members where they 
can view the application while the agency reviews it; (3) permitting 
agencies may require a facility to set up an information repository at 
any point during the permitting process if warranted; and (4) 
permitting agencies must notify the public prior to a trial (or test) 
burn.
    As discussed in the preamble to the proposal (69 FR 21318), we 
believe that the NIC process addresses the first two RCRA public 
participation requirements. The NIC process requires a source to make 
its draft NIC, which discusses the source's plan for coming into 
compliance with the MACT standards, available for public review and to 
hold an informal public meeting to discuss the activities contained in 
the NIC. While the NIC process gives the public an early opportunity to 
participate in the unit's compliance planning process early on, a few 
components are still missing before we can consider the first 2 RCRA 
public participation requirements to be fulfilled under the MACT 
framework. One component is that there is no permit action associated 
with the NIC requirements. However, the NSR program can provide a 
permit mechanism that will determine whether or not a source may be 
constructed.\248\ The steps associated with obtaining an NSR permit, or 
a ``pre-construction'' permit, are similar, but not necessarily 
identical to that required under RCRA. They are: (1) Preparation of the 
permit application (sources must provide the location, design, 
construction, and operation information) and participation in pre-
application meetings; (2) issuance of permit application completeness 
determination by the State; (3) development and negotiation of draft 
permit; (4) opportunity for public notice and comment on the draft 
permit; (5) response of permitting authority to public comments; (6) 
possible administrative and judicial appeals; and (7) permit issuance/
denial.\249\
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    \248\ We believe that the majority of new units will be 
classified as major sources for NSR permitting (requiring either 
prevention of significant deterioration or nonattainment permits), 
however, those that do not, will likely be required to obtain a 
minor NSR permit. In few cases, new sources (e.g., newly constructed 
as opposed to modified) may not be required to obtain an NSR permit 
if its potential to emit does not exceed the NSR threshold level.
    \249\ With respect to numbers 4 and 5, many States omitted the 
public participation steps in their federally approved SIPs. This 
was the reason why Sierra Club had been opposed to our efforts to 
simply rely on NSR permitting to provide public participation 
opportunities that would have been otherwise provided under the 
traditional RCRA permit process for new units. Today, however, many 
SIPs have been revised to address public participation requirements.
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    A second component is that the NIC does not provide the information 
on the proposed combustor operations or emissions information that 
would normally be available as part of the RCRA process. To address 
these gaps between RCRA and MACT, we are requiring an approach similar 
to that which was proposed. New sources must: (1) Prepare a draft NIC 
and make it available to the public at the same time as their RCRA pre-
application meeting notice; (2) provide a draft of their comprehensive 
performance test (CPT) plan (to the public) to coincide with the draft 
NIC and RCRA pre-application meeting notices; and (3) hold their NIC 
public meeting with their RCRA informal public meeting. The first two 
requirements ensure that the public is provided with most of the same 
information that would have been available via the RCRA trial burn plan 
prior to the source burning hazardous waste. Other information not 
required by the NIC or CPT plan, such as the combustion unit's design 
specifications will, in most cases, be available to the public through 
the NSR permit application. We recommend that sources submit a copy of 
their NSR permit application to the RCRA permit authority so that this 
information is readily available for development of the RCRA permit. 
The third requirement allows the public to inquire and comment on both 
the new unit's proposed activities and operations. By requiring new 
sources to develop, notice, and hold a combined public meeting that 
encompasses the NIC, draft CPT plan, and RCRA pre-application notice 
information, the public will be provided with all information related 
to the combustor's compliance plans as well as its operating plans and 
emissions estimates prior to burning hazardous waste. See new 
requirements in Sec.  63.1212.
    With respect to the requirements we are finalizing today, we 
received only one comment that expressed concern. The concern is that 
the requirement to submit the CPT plan is too early in the compliance 
process. For example, the RCRA application is submitted approximately 
2-3 years before start-up whereas the CPT plan is required 1.5 years 
after the final NIC is due.\250\ The commenter feels that the facility 
would not have enough time to learn about the ``detailed nuances of the 
system''. However, the commenter does note that it is possible to 
submit the CPT plan, but it will not be as complete or refined as it 
would be if it was submitted according to the deadline for existing 
units. We agree with the commenter that a considerable amount of 
planning is required of the source to be able to draft the CPT plan at 
such an early stage, but we are only requiring that a draft of the CPT 
plan be made available, with the final CPT plan due 6 months prior to 
the source's compliance date. Moreover, at this early stage, we liken 
the development of the draft CPT plan to the development of the trial 
burn plan. Even though it may not be as complete or refined as it will 
be when the final CPT plan is due, we believe that it will still be of 
benefit to the public and the regulatory authority, but also to the 
source in terms of advance planning for the design of the unit through 
start-up of the unit.
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    \250\ Comprehensive performance test plans are required to be 
submitted one year in advance of the scheduled test. The submittal 
date would be as late as 2.5 years after the effective date of the 
rule assuming no extensions are granted.
---------------------------------------------------------------------------

    The components thus far, have satisfied the first (2) two RCRA 
public participation requirements. The third RCRA public participation 
requirement enables a regulatory authority to evaluate the need for and 
require a facility to establish and maintain an information repository. 
The establishment of an information repository is typically required 
only when there are concerns or unique information needs of a 
community. The purpose of the information repository is to make 
information regarding the facility (and combustion unit) available to 
the public during the permit issuance process and during the life of 
the permit. In the preamble, we noted that

[[Page 59522]]

although the Title V permit process contains a provision that any 
materials relevant to the permit decision be made available to 
interested persons (see Sec.  70.7(h)(2) and Sec.  71.11(d)), the 
information may not be made available until well after the combustor is 
constructed and operating. Consequently, we have chosen to adopt 
additional provisions under the NIC requirements that parallel the 
requirements of Sec.  124.33.
    We had proposed two options that would allow a regulatory authority 
to require, on a case-by-case basis, a source to establish an 
information repository specific to the combustor. The first option was 
to place such a provision in the NIC regulations and the second option 
was to amend the applicability language in Sec.  124.33 to include 
combustion sources that will comply with Part 63, subpart EEE upon 
start-up. Two commenters felt that the second option would create 
problems as far as organization (i.e., by modifying the RCRA 
regulations to include a provision solely for new units complying with 
MACT). We agree that the second option could be confusing and that it 
would be more appropriate to keep all new requirements for new units in 
one set of regulations. Therefore, we are finalizing a provision that 
will allow for an information repository to be established specific to 
the combustor (recall that a repository established pursuant to the 
RCRA permit will include documents relevant to the facility only), if 
deemed appropriate, under the NIC regulations. See new Sec.  
63.1212(c). Under the NIC regulations, the repository could include the 
NIC, test plans, draft Title V permit and application, reports, et 
cetera.
    The fourth and final RCRA public participation requirement to be 
fulfilled is for the regulatory authority to notify the public of an 
impending trial burn or test burn. As discussed in the RCRA Expanded 
Public Participation Rule, the RCRA permit authority will typically 
provide the notice at least 30 days in advance of the test (60 FR 
63426, December 11, 1995). Similarly, the MACT regulations require an 
existing or new unit to provide notice to the public that the CPT plan 
(and the continuous monitoring system performance evaluation test plan) 
is available for review. The regulations in Sec.  63.1207(e)(2) fulfill 
this requirement. Although the CPT plan may not be approved before the 
public is notified, the intent is to provide notice to the public of a 
future test. We believe that the MACT regulations provide public notice 
of the test plans that are commensurate with the RCRA regulations and 
thus, no additional regulatory revisions or amendments are needed.
4.a. Process for New Units Seeking an Initial RCRA Permit
    We anticipate that the process for new units seeking an initial 
permit will work as follows. Any new unit would begin the process by 
developing and compiling the information necessary for the RCRA draft 
permit (e.g., information required for the part A application at Sec.  
270.13, the relevant general information for the part B application 
according to Part 270) and the applicable NSR permit.\251\ The 
information needed to compile the draft NIC and draft CPT plan would be 
gathered simultaneously, as if the source were developing the trial 
burn plan. When the source has compiled its RCRA permit application, 
draft NIC and draft CPT plan, it would submit a RCRA pre-application 
meeting notice at least 30 days prior to the date scheduled for the 
RCRA informal public meeting according to Sec. Sec.  124.31(b) and (d). 
At the time of the RCRA pre-application meeting notice, the source 
would also issue notice of the NIC public meeting (at least 30 days 
prior to the NIC meeting) according to Sec.  63.1210(c)(3), so that the 
two meetings can occur at the same time. In order for the public to be 
able to view all information relevant to the combustor before the 
combined RCRA pre-application and NIC public meeting, the source would 
make the draft NIC and draft CPT plan available to the public for 
review at the same time the notices for the meetings are issued. To aid 
the RCRA permit authority in its development of the draft RCRA permit 
(i.e., mainly for purposes of evaluating risk), we strongly recommend 
that the source also provide copies of the draft NIC, draft CPT plan, 
and NSR application (if applicable) to the RCRA permit authority. It is 
our hope that the availability of information will expedite the 
development of the draft permit. All notices should be presented to the 
public in sufficient time to allow for a combined RCRA informal public 
meeting and NIC public meeting.
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    \251\ Because the information required for NSR permit is less 
comprehensive than a RCRA permit, it allows for a much shorter time 
period for issuance. The average time for issuing a PSD permit, for 
example, after receiving an application is slightly more than 7 
months, but varies depending upon public involvement and negotiation 
of the application content. USEPA. Docket A-2001-19, Document II-A-
01. NSR 90-Day Review Background Paper, June 22, 2001.
---------------------------------------------------------------------------

    Following the combined public meeting, the source will submit its 
RCRA permit application and the RCRA regulatory authority will prepare 
and issue a draft permit. The public will then have an opportunity to 
comment on the draft permit and request a public hearing. Upon 
resolution of any issues surrounding the draft permit, a final RCRA 
permit will be issued. The RCRA process is the same as before, but 
should be reasonably shorter. Finally, the new unit may begin burning 
hazardous waste when it can assure it will operate in compliance with 
the MACT standards (i.e., by placing a documentation of compliance in 
its operating record on the day it begins burning hazardous waste). See 
new regulatory language at Sec.  63.1212(c). To aid readers in 
understanding the above process, we have included a pictorial timeline. 
Please see figure 2.
    Finally, it may also be feasible to combine an NSR pre-application 
meeting and public notice of the draft NSR permit with the process 
described above. Thus, we recommend that sources work closely with 
their Air and RCRA permit agencies so that the NSR public notices and 
meetings may be coordinated with the RCRA and NIC notices and meetings 
so time and resources are efficiently utilized.
4.b. Process for New Units Modifying an Existing RCRA Permit
    The process of adding a new unit to an existing permit is 
accomplished through a Class 3 permit modification (see Sec.  270.42 
(c) for requirements). The requirements governing public notices of the 
draft NIC, draft CPT plan, and holding a combined public meeting are 
essentially the same as new units seeking an initial permit. The 
process is as follows. The source prepares and submits its RCRA permit 
modification request (and if applicable, NSR application). It must then 
publish a notice of the modification request seven days later, followed 
by a public meeting no earlier than 15 days after publication of the 
notice for the modification request, and no later than 15 days before 
the close of the 60-day comment period. As with new units that are 
submitting an initial RCRA permit application, it is also important for 
sources seeking to modify their permit to coordinate their NIC public 
meeting with their RCRA permit modification public meeting. This is 
made possible due to the flexibility of the NIC public meeting; it can 
be held any time prior to the 10 month deadline. After the combined 
public meeting and the close of the comment period, the permit 
authority will either grant or deny the modification request. If 
approved, the source may then begin construction or modification of the 
unit. To aid readers in understanding the timing of the

[[Page 59523]]

above process, we have included a pictorial timeline. Please see figure 
2.
    Again, it may be feasible to combine an NSR pre-application meeting 
and public notice of the draft NSR permit with the process described 
above. Thus, we recommend that sources work closely with their Air and 
RCRA permit agencies so that the NSR public notices and meetings may be 
coordinated with the RCRA and NIC notices and meetings so time and 
resources are efficiently utilized.

E. What Other Permitting Requirements Were Discussed in the Proposal?

    At proposal, we discussed where most Phase 1 sources would be in 
terms of their transition from their RCRA permit requirements to 
compliance with the MACT Interim Standards (see 69 FR 21321). The 
transition process was discussed with respect to both the RCRA permit 
and the Title V permit. However, when we discussed the Title V permit 
requirements in the proposal, we did not elaborate on the transition 
between the Interim Standards and Replacement Standards. Because we 
believe that such a discussion would be helpful to readers, we have 
included general information describing how the transition process 
would work for most sources in Section B. Did Commenters Express any 
Concerns Regarding the Current Permitting Requirements?, subsections 3 
and 4.
    For Phase 2 sources, we proposed the same permitting approach as we 
did for Phase 1 sources. Today, we are finalizing as proposed, the 
following for Phase 2 sources: (1) the new Phase 2 emissions standards 
will be placed only in the CAA regulations at 40 CFR part 63, subpart 
EEE, and be implemented through the air program; (2) with few 
exceptions, the analogous standards in the RCRA regulations no longer 
apply once a facility demonstrates compliance with the MACT standards 
in subpart EEE and any duplicative requirements have been removed from 
the RCRA permit; and (3) the new standards will be incorporated into 
operating permits issued under Title V of the CAA rather than be 
incorporated into RCRA permits. Consequently, we are finalizing the 
proposed changes to Sec. Sec.  270.22 and 270.66 to implement the 
above. Also applicable to Phase 2 sources via today's final rule are 
the changes and additions we finalized in the 1999 final rule for Phase 
1 sources. These include a streamlined RCRA permit modification 
procedure to allow sources to make upgrades to comply with MACT 
(Sec. Sec.  270.42(j) and 270.42 appendix I, section L.9), a second 
streamlined RCRA permit modification procedure to remove conditions 
from a permit that are no longer applicable (Sec.  270.42 appendix I, 
section A.8), an addition to Sec.  270.235 to specify conditions for 
start-up, shutdown, and malfunction plan and integrate them with the 
CAA program, and an amendment to the interim status regulations at 
Sec.  270.72 to exempt interim status facilities from the 
reconstruction limitation when making upgrades to comply with MACT.
    Also, we are finalizing three new permitting changes that are 
applicable to both Phase 1 and 2 sources. Two have been discussed 
previously in this section and are: (1) A new streamlined RCRA permit 
modification procedure designed to reduce overlap during the transition 
from RCRA to MACT (Sec. Sec.  270.42(k) and 270.42, appendix I, L.10); 
and (2) regulatory provisions stating that new units are no longer 
subject to the full array of RCRA combustion permitting requirements. 
The third change is discussed above in Section IX. Site-Specific Risk 
Assessment Under RCRA and finalizes our response to a petition for 
rulemaking with respect to site-specific risk assessments (SSRAs). As 
part of this change we have decided to adopt regulatory language that 
specifically provides clarification of authority for RCRA permit 
writers to evaluate the need for and, where appropriate, require SSRAs 
and to add conditions to RCRA permits that they determine, based on the 
results of an SSRA, are necessary to protect human health and the 
environment.
    Last, as explained in part four section II.A, we are finalizing our 
decision to regulate emissions of dioxin/furans, mercury, polycyclic 
organic matter, and polychlorinated biphenyls from Phase 2 area sources 
under section 112(d).\252\ This means that Phase 2 area sources are 
subject to MACT standards only for these hazardous air pollutants (HAP) 
in the final rule. To reiterate, they are: Dioxin/furans, mercury, and 
polycyclic organic matter (controlled by the surrogates DRE and carbon 
monoxide/hydrocarbon). For the remaining HAP (hydrogen chloride and 
chlorine gas and metals other than mercury), Phase 2 area sources may 
either comply with the MACT standards for Phase 2 major sources or 
continue complying with the RCRA standards and requirements of their 
RCRA permit.
---------------------------------------------------------------------------

    \252\ As explained in the Comment Response Document vol. V, 
although Sec.  502(a) allows EPA to exempt area sources from title V 
permitting requirements if EPA finds that those requirements would 
be (among other things) ``unnecessarily burdensome'', we believe 
that Title V requirements remain appropriate for these sources given 
the highly toxic nature of the HAP and the importance of affording 
opportunity for public participation as provided for in the Title V 
permit issuance process.
---------------------------------------------------------------------------

    In the 2004 proposal, we stated that we were not making a positive 
area source finding for Phase 2 area sources as we have for Phase 1 
area sources (69 FR 21212 and 21325). Regardless of this, however, the 
Phase 2 area sources are still subject to the requirement to obtain a 
Title V permit because they are subject to section 112 standards under 
this subpart. See Sec.  502(a) of the CAA and 40 CFR Sec. Sec.  
70.3(b)(2) and 71.3(b)(2).
    It is important to note that the Title V applications for the Phase 
2 area sources will need to contain emissions information relative to 
all regulated air pollutants (to determine applicable requirements, 
fees, etc.) that are being emitted from the units subject to the MACT 
standards, not just the specific HAP pollutants regulated by the MACT 
standards (see Sec. Sec.  70.5(c)(3)(i) and 71.5(c)(3)(i)). Although, 
the permit itself would contain standards only for the HAP subject to 
MACT standards (the Sec.  112(c)(6) HAP). A Phase 2 area source which 
chooses to control hydrogen chloride, chlorine gas, and metals other 
than mercury by continuing to comply with the relevant RCRA standards 
and the requirements of its RCRA permit should note this choice in its 
Title V application and cite to the relevant requirements of this 
subpart. This will help ensure that the permitting authority is aware 
that these requirements apply in lieu of the MACT standards for Phase 2 
major sources. The permitting authority should also document this 
choice in the statement of basis for the source's Title V permit. See 
Sec. Sec.  70.7(a)(5) and 71.7(a)(5). Finally, for the units at a 
source which are subject to the subpart EEE MACT standards, all CAA 
applicable requirements to which these units are subject, e.g., State 
Implementation Plan requirements, not just the relevant Subpart EEE 
requirements, must be included in the Title V permits issued to these 
sources. See Sec. Sec.  70.3(c)(2) and 71.3(c)(2). For more information 
regarding Sec.  112(c)(6) and how it relates to Phase 2 area sources, 
see Part Four, Section II.A., ``Area Source Boilers and Hydrochloric 
Acid Production Furnaces''.
BILLING CODE 6560-50-P

[[Page 59524]]

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[[Page 59525]]


[GRAPHIC] [TIFF OMITTED] TR12OC05.005


[[Page 59526]]



Part Five: What Are the CAA Delegation Clarifications and RCRA State 
Authorization Requirements?

I. Authority for This Rule

    Today's rule amends the promulgated standards located at 40 CFR 
part 63, subpart EEE. It amends the standards for the Phase 1 source 
categories--incinerators, cement kilns, and lightweight aggregate kilns 
that burn hazardous waste, and it also amends subpart EEE to establish 
MACT standards for the Phase 2 source categories--boilers and 
hydrochloric acid production furnaces that burn hazardous waste. 
Additionally, this rule amends several RCRA regulations located in 40 
CFR part 270 to reflect changes in applicability, addition of a new 
permit modification procedure, and additions related to site-specific 
assessments and permitting.

II. CAA Delegation Authority

    Before discussing the clarifications being finalized today, it is 
important to first highlight a few key aspects of delegation authority. 
Recall from the proposal that a state, local, or tribal (S/L/T) agency 
must be delegated authority under CAA section 112(l) before it can 
exercise the delegable provisions' authorities. The delegable 
authorities can be found in 40 CFR 63.91(g)(1)(i), also known as 
Category I Authorities. A S/L/T agency that has applied for and 
received delegation authority can approve: test plans, requests for 
minor and in most cases, intermediate changes to monitoring and test 
methods, performance test waivers, and several other Category I 
Authorities. Please note that even though a S/L/T agency may have an 
approved Title V permit program, it cannot exercise delegable 
authorities or be the primary enforcement authority if it has not 
received delegation authority under CAA section 112(l). Moreover, when 
a S/L/T agency has not taken delegation of a section 112 standard, the 
agency can only incorporate the section 112 standard's requirements 
into its Title V permits, (and then implement and enforce these 
requirements through its title V permits) when it has adequate 
authority under State, local, or tribal law which allows it to conduct 
the above actions without delegation. See, e.g., the proposed Federal 
Plan for Commercial and Industrial Solid Waste Incinerators, November 
25, 2002 (67 FR 70640, 70652). Please also refer to 69 FR 21335 of the 
proposal and the fact sheet entitled, Clean Air Act Delegation for the 
HWC NESHAP at: http://www.epa.gov/epaoswer/hazwaste/combust/toolkit/factshts.htm to learn more about the advantages of receiving delegation 
authority.
    Also, we would like to point out that there are several delegation 
options that S/L/T agencies can receive. Regardless, many S/L/T 
agencies choose the ``straight delegation'' option when applying for 
delegation approval. Straight delegation means that these agencies have 
agreed to implement and enforce federal MACT standards as they have 
been written in the promulgated requirements. As a result, many EPA 
Regions and states have established memoranda of agreement that 
essentially provide automatic delegation of each future MACT, as 
opposed to the state applying for delegation of each future MACT, which 
requires a rulemaking to implement. For more information related to the 
delegation options and procedures, please refer to the fact sheet, 
Clean Air Act Delegation for the HWC NESHAP at: http://www.epa.gov/epaoswer/hazwaste/combust/toolkit/factshts.htm and EPA's delegation 
website at: http://www.epa.gov/ttnatw01/112(l)/112-lpg.html.

III. Clarifications to CAA Delegation Provisions for Subpart EEE

    In the proposal, we discussed the need to provide additional 
clarification for the delegable and non-delegable authorities within 
Subpart EEE based upon our implementation experience with the Phase 1 
Interim Standards and the Clarifications to Existing National Emissions 
Standards for Hazardous Air Pollutants Delegation' Provisions final 
rule published on June 23, 2003 (68 FR 37334). Although the June 23, 
2003 final rule provided clarification and streamlined the delegable 
provisions for each existing NESHAP, it overlooked several non-
delegable and delegable authorities within Subpart EEE. It provided 
clarification on the non-delegable authorities of Subpart EEE as they 
relate to major alternatives to the standards themselves and to test 
methods, monitoring, or recordkeeping and reporting under the General 
Provisions.\254\ However, it omitted major alternatives specific to 
Subpart EEE such as: test methods under Sec. Sec.  63.1208(b) and 
63.1209(a)(1); monitoring under Sec.  63.1209(a)(5) and; recordkeeping 
and reporting under Sec.  63.1211(a) through (d). Therefore, the 
following paragraphs will explain which authorities in Subpart EEE are 
delegable and are not delegable to S/L/T agencies that have been 
delegated authority and will provide some examples of or references to 
alternative requests associated with each delegable or non-delegable 
provisions authority.
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    \254\ For example, the final rule included approval of 
alternatives to requirements in Sec. Sec.  63.1200, 63.1203, through 
63.1205, and 63.1206(a); approval of major alternatives to test 
methods under Sec.  63.7(e)(2)(ii) and (f); approval of major 
alternatives to monitoring under Sec.  63.8(f) and; approval of 
major alternatives to recordkeeping and reporting under Sec.  
63.10(f).
---------------------------------------------------------------------------

    To review, the regulations at 40 CFR 63.90 define three types of 
alternative requests. Alternative requests or ``changes'' to a 
particular delegable or non-delegable provision are classified as 
major, intermediate, or minor depending upon the degree (i.e., 
potential to be nationally significance, potential to reduce the 
stringency of the standard, etc.) of change being requested. An 
alternative request that qualifies as a major change is not delegable 
to S/L/T agencies, even when they have delegation authority. These 
requests must be sent to the EPA Region or, if it concerns a test 
method under Sec. Sec.  63.7(e)(2)(ii) and (f), 63.1208(b) and 
63.1209(a)(1) or a standard under Sec. Sec.  63.1200, 63.1206(a), or 
63.1216-63.1221, then it must be sent to our Office of Air Quality 
Planning and Standards (OAPQS).\255\ An alternative request that 
qualifies as an intermediate or minor change is delegable. However, the 
EPA Region may choose whether or not they will delegate authority to S/
L/T agencies to approve intermediate and, even some minor changes 
during the delegation approval process. In addition to the regulations, 
the guidance document entitled, How to Review and Issue Clean Air Act 
Applicability Determinations and Alternative Monitoring (EPA 305-B-99-
004, February 1999) provides a listing of delegable and non-delegable 
authorities in Tables 1 and 2, as well as descriptions and examples of 
major, intermediate, and minor changes in Attachment 1.
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    \255\ For contact information, please visit www.epa.gov/ttn/emc/staffdir.html.
---------------------------------------------------------------------------

A. Alternatives to Requirements

    Any change to a promulgated standard is considered a major change 
and as noted above, must be sent to OAQPS (see contact information in 
footnote). The reason why a change to a standard must be sent to EPA 
Headquarters is because the change must be established through national 
rulemaking, regardless of the degree of change sought. Thus, only OAQPS 
can approve alternative requests for changes to standards. 
Additionally, any change to applicability requirements and compliance 
dates (e.g., requirements that ensure that the standards are achieved 
as EPA intended) are also

[[Page 59527]]

considered major and also must be sent to OAQPS for approval. Specific 
to Subpart EEE, alternative requirement requests including those 
pursuant to Sec. Sec.  63.1200, 63.1206(a), or 63.1216-63.1221 are 
considered major changes and consequently are non-delegable. The 
regulations at Sec.  63.1214(c) correctly identified the requirements 
in Subpart EEE, however we have revised them today (as we proposed) to 
reflect the new sections that house the Phase 1 Replacement Standards 
and Phase 2 Standards.
    There are a few exceptions to the above, however. Subpart EEE 
incorporates specific provisions for sources to request alternative 
standards which are delegable because they have been established 
through rulemaking. In fact, several alternative standards are self-
implementing meaning that the source only need specify in their DOC 
which standard it will comply with. The alternative to the particulate 
matter standard in Sec.  63.1206(b)(14) and the emissions averaging 
standards for cement kilns with in line kiln raw mills and preheater or 
preheater/precalciner kilns with dual stacks in Sec.  63.1204(d) and 
(e) are three examples. There are also alternative standards that 
sources may petition to comply with. They include: Alternatives to the 
standards for existing and new LWAKs at Sec.  63.1206(9) and cement 
kilns at Sec.  63.1206(b)(10) and the alternative risk-based standard 
for total chlorine at Sec.  63.1215. Sources choosing to comply with 
these alternative standards must receive approval from their delegated 
S/L/T agency prior to implementing them.\256\ With respect to changes 
to compliance dates, requests under Sec.  63.1213 specifically allow 
sources to request an extension to the compliance date for the 
installation of pollution prevention or waste minimization controls. 
Again, because this provision has been specified in subpart EEE, it is 
not considered a major change and is delegable.
---------------------------------------------------------------------------

    \256\ The alternative risk-based standard for total chlorine at 
Sec.  63.1215 requires sources to submit their eligibility 
demonstration to both the delegated S/L/T agency and to the Risk and 
Exposure Assessment Group in Research Triangle Park, NC for review, 
even though the delegated S/L/T agency can grant or deny approval.
---------------------------------------------------------------------------

B. Alternatives to Test Methods

    With respect to test methods, we noted above that the final 
delegations rule stated that major alternatives to the test methods at 
Sec. Sec.  63.7(e)(2)(ii) and (f) were not delegable. Therefore, as we 
proposed, it is necessary to add major alternatives to 63.1208(b), 
which specifies the test methods sources must use to determine 
compliance with subpart EEE. Also, we are adding the CEMS monitoring 
requirement under Sec.  63.1209(a)(1). It is regarded as a test method 
because it serves as a benchmark method for demonstrating compliance 
with the emission standards. Both sections are delegable to S/L/T 
agencies as long as they have been delegated authority and as long as 
the alternative requests comprise minor or intermediate changes. 
However, a major change to either of these test method sections must be 
sent to OAQPS for approval.\257\ Only OAQPS can approve major changes 
to test methods because they are designated in the standard as the 
means for determining compliance with an emission standard. The 
proposed revisions to Sec.  63.1214 are finalized today to include 
major alternatives to test methods under Sec. Sec.  63.1208(b) and 
63.1209(a)(1) as non-delegable authorities.
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    \257\ For contact information, please visit www.epa.gov/ttn/emc/staffdir.html.
---------------------------------------------------------------------------

C. Alternatives to Monitoring

    For monitoring, the final delegations rule stated that major 
alternatives to monitoring at Sec.  63.8(f) were not delegable, but did 
not reference monitoring specific to subpart EEE. In subpart EEE, the 
monitoring requirements are located in Sec.  63.1209. This section also 
includes two provisions specific to alternative monitoring, thus 
removing some of the ``guesswork'' when trying to discern whether a 
request for change is minor, intermediate, or major. One is located at 
Sec.  63.1209(a)(5), Petitions to use CEMS for other standards and the 
other is located at Sec.  63.1209(g)(1), Alternative monitoring 
requirements other than continuous emissions monitoring systems. Each 
is discussed in the following paragraphs.
    In the proposal, we explained that a request to use other 
monitoring in lieu of a CEMS is always considered a major change due to 
CEMS generally being considered a more accurate measure of compliance. 
However, if a source requests to use a CEMS in lieu of a required 
operating parameter, it may be considered an intermediate change. Since 
publication of the proposal, performance specifications have been 
promulgated for PM CEMS (and mercury CEMS).\258\ Consequently, today we 
view requests per Sec.  63.1209(a)(5) to use PM CEMS as intermediate 
changes to monitoring. Although the implementation of PM CEMS according 
to PS-11 (69 FR 1786 and 40 CFR part 60, Appendix B; January 12, 2004) 
and Procedure 2 (see also 40 CFR part 60, Appendix F) is largely 
``self-implementing,'' sources wishing to apply to use of PM CEMS 
should develop and submit QA/QC plans specifying audit frequencies to 
account for site-specific stack conditions. We believe that other site-
specific issues that may need to be addressed prior to use of the CEMS, 
such as a source's request to deviate from PS-11 or a source's 
selection of the correct correlation curve(s), are properly addressed 
under EPA's established policies and procedures for alternative method 
requests. We believe that a petition to use PM CEMS under Sec.  63.8(f) 
is still the appropriate mechanism, but that sources can submit their 
petitions to their delegated S/L/T agency for review and approval, and 
we recommend that EPA Regional offices work with these agencies to 
monitor implementation. Thus, with the exception of petitions to use PM 
CEMS in lieu of an operating parameter which is considered an 
intermediate change, we are finalizing our proposed revision to Sec.  
63.1214(c) to include major alternatives to monitoring under Sec.  
63.1209(a)(5) as a non-delegable authority.
---------------------------------------------------------------------------

    \258\ Although performance specifications have been promulgated 
for mercury CEMS, there has not been as much experience in 
implementing these devices for hazardous waste combustion sources 
(or similar sources) as there has been for PM CEMS at this time. 
Therefore, we believe it appropriate to continue sending requests to 
use mercury CEMS in lieu of an operating parameter to the 
appropriate EPA Region for review and approval.
---------------------------------------------------------------------------

    Section 63.1209(g)(1), Alternative monitoring requirements other 
than continuous emissions monitoring systems, contains the other 
alternative monitoring provision. This provision allows sources to 
request alternative monitoring methods to monitor compliance, except 
for those standards that must be monitored with a CEMS (e.g., those in 
Sec.  63.1209(a)(1)), and to request a waiver of an operating parameter 
limit. We provided several examples of alternative parameter monitoring 
for which a request may be submitted under this section in the proposal 
at 69 FR 21337. They include use of: a different detector, different 
monitoring location, a different method as recommended by the 
manufacturer, or a different averaging period that is more stringent 
than the applicable standard. In the proposal, we stated that we 
believe the majority of requests submitted pursuant to Sec.  
63.1209(g)(1) are not major and discussed in the preamble amending the 
language in Sec.  63.1209(g)(1) so that these types of changes could be 
reviewed and approved by the delegated S/L/T agency. However, when we 
added

[[Page 59528]]

language to Sec.  63.1209(g)(1) to allow for the above, we 
inadvertently referred to an approved Title V program instead of a S/L/
T agency which has taken delegation of subpart EEE. We have corrected 
and finalized the proposed language. Therefore, whether minor or 
intermediate, requests under Sec.  63.1209(g)(1) may be sent to your 
delegated S/L/T agency for review and approval.
    Please note that 63.1209(g)(1) cannot be used when requesting major 
changes to the monitoring required by the standard. Such changes 
typically involve new unproven monitoring methods. Unproven monitoring 
methods refer to those where the technology or procedures are not 
generally accepted by the scientific community (Sec.  63.90(a)). If you 
are uncertain whether your request constitutes a new unproven 
monitoring method, which is considered a major change, you should 
submit your request to your EPA Region. The regulatory language in 
63.1209(g)(1) has been revised to reflect this clarification.

D. Alternatives to Recordkeeping and Reporting.

    As with the others, the final delegation provisions' rule only 
cited the waiver of recordkeeping and reporting requirements of Sec.  
63.10(f) as a non-delegable provision. Thus, it is necessary to add the 
relevant subpart EEE recordkeeping and reporting requirements of Sec.  
63.1211. Section 63.1211 is delegable in its entirety to S/L/T agencies 
unless an alternative request is determined to be a major change. An 
alternative request that is a major change, such as decreases in record 
retention for all records, must be sent to your EPA Region for review 
and approval. Similar to the monitoring section, Sec.  63.1211 contains 
a specific alternative provision. Section 63.1211(d) Data Compression, 
allows sources to request to use data compression techniques to record 
data from CMS and CEMS on a frequency less than that required by Sec.  
63.1209. We view the alternative request to be a minor change because 
available guidance provides criteria for defining fluctuation and data 
compression limits. See 64 FR 52961 and 52962, September 30, 1999. 
Therefore, requests submitted under 63.1211(d) can be consistently 
evaluated by delegated S/L/T agencies. Section 63.1214(c) has been 
revised to specify that major alternatives to 63.1211(a)--(c) are non-
delegable authorities.

E. Other Delegation Provisions

    Although not discussed in the proposal, it is important to note 
that issuing applicability determinations is another delegable 
authority. The EPA document How to Review and Issue Clean Air Act 
Applicability Determinations and Alternative Monitoring (EPA 305-B-99-
004, February 1999) provides guidance regarding who has the lead for 
issuing applicability determinations. In general, Regions may delegate 
the authority to issue applicability determinations to S/L/T agencies 
when the determinations are routine in nature. However, delegation of 
authority for certain applicability determinations should be retained 
by the Regions. These include applicability determinations that: (1) 
Are unusually controversial or complex; (2) have bearing on more than 
one state or district (are multi-Regional); (3) appear to create 
conflict with previous policy or determinations; (4) are a legal issue 
which has not previously been considered (a matter of first 
impression); or (5) raise new policy questions. It is recommended that 
Regional offices require notification when S/L/T agencies issue 
applicability determinations.

IV. RCRA State Authorization and Amendments to the RCRA Regulations

    Under section 3006 of RCRA, EPA may authorize qualified states to 
administer their own hazardous waste programs in lieu of the federal 
program within the state. Following authorization, EPA retains 
enforcement authority under sections 3008, 3013, and 7003 of RCRA, 
although authorized states have primary enforcement responsibility. The 
standards and requirements for state authorization are found at 40 CFR 
Part 271.
    Prior to enactment of the Hazardous and Solid Waste Amendments of 
1984 (HSWA), a State with final RCRA authorization administered its 
hazardous waste program entirely in lieu of EPA administering the 
federal program in that state. The federal requirements no longer 
applied in the authorized state, and EPA could not issue permits for 
any facilities in that state, since only the state was authorized to 
issue RCRA permits. When new, more stringent federal requirements were 
promulgated, the state was obligated to enact equivalent authorities 
within specified time frames. However, the new federal requirements did 
not take effect in an authorized state until the state adopted the 
federal requirements as state law.
    In contrast, under RCRA section 3006(g) (42 U.S.C. 6926(g)), which 
was added by HSWA, new requirements and prohibitions imposed under HSWA 
authority take effect in authorized states at the same time that they 
take effect in unauthorized states. EPA is directed by the statute to 
implement these requirements and prohibitions in authorized states, 
including the issuance of permits, until the state is granted 
authorization to do so. While states must still adopt HSWA related 
provisions as state law to retain final authorization, EPA implements 
the HSWA provisions in authorized states until the states do so.
    Authorized states are required to modify their programs only when 
EPA enacts federal requirements that are more stringent or broader in 
scope than existing federal requirements. RCRA section 3009 allows the 
states to impose standards more stringent than those in the federal 
program (see also 40 CFR 271.1). Therefore, authorized states may, but 
are not required to, adopt federal regulations, both HSWA and non-HSWA, 
that are considered less stringent than previous federal regulations.
    We discussed in the proposal which RCRA regulations we intended to 
amend and their impact on state authorization procedures. Today, we are 
finalizing those amendments in Sec. Sec.  270.10, 270.22, 270.32, 
270.42, 27062, 270.66, and 270.235. In addition, we are amending the 
regulations in Sec. Sec.  264.340 and 266.100 to reflect changes that 
have been made based upon comments. Today's amendments fall under both 
HSWA and non-HSWA authorities. That is, changes made to regulations 
applicable to boilers and industrial furnaces are promulgated under 
HSWA authority, whereas changes made to regulations applicable to 
incinerators are promulgated under non-HSWA authority. \259\ All of the 
amendments made today are considered to be either less stringent or 
equivalent to the existing Federal program, which means that states are 
not required to adopt and seek authorization for these provisions 
regardless of whether they are finalized under non-HSWA or HSWA 
authorities. Nevertheless, we strongly encourage states to become 
authorized for today's amendments.

[[Page 59529]]

Experience has shown that when states have been authorized for previous 
amendments (i.e., those finalized in the 1999 rule) that were intended 
to facilitate the transition from the RCRA program to MACT and the CAA 
Title V program, the process has proven to be less cumbersome. For a 
more detailed discussion of non-HSWA and HSWA authorities with respect 
to how and when they take effect, please refer to the proposal's 
preamble discussion at 69 FR 21338.
---------------------------------------------------------------------------

    \259\ When new requirements and prohibitions (that are more 
stringent than the previous federal regulations) are imposed under 
non-HSWA authority, the new federal requirements do not take effect 
in an authorized state until the state adopts the federal 
requirements as law. Conversely, when imposed under HSWA authority, 
the new federal requirements are federally enforceable in an 
authorized state until the necessary changes to a state's 
authorization are approved by EPA.
---------------------------------------------------------------------------

    Several RCRA sections that have been enacted as part of HSWA apply 
to today's rule: 3004(o), 3004(q), and 3005(c)(3). Thus, if a state is 
not authorized for the boiler and industrial furnace regulations, these 
provisions are federally enforceable in an authorized state until the 
necessary changes to a state's authorization are approved by us. See 
RCRA section 3006, 42 U.S.C. 6926. We are adding today's requirements 
to Table 1 in 271.1(j) where rulemakings promulgated pursuant to HSWA 
authority are identified.

Part Six: Impacts of the Final Rule

I. What Are the Air Impacts?

    Table 1 below shows the emissions reductions achieved by the final 
rule for all existing hazardous waste combustors. For Phase I sources--
incinerators, cement kilns, and lightweight aggregate kilns--the 
emission reductions represent the difference in emissions between 
sources controlled to today's standards and estimated emissions when 
complying with the interim MACT standards promulgated on February 13, 
2002. Thus, the significant emissions reductions already achieved by 
the interim standards are not reflected in the estimates shown in Table 
1.\260\ For Phase II sources--solid fuel boilers, liquid fuel boilers, 
and hydrochloric acid production furnaces--the reductions represent the 
difference in emissions between today's standards and the current 
baseline of control provided by 40 CFR part 266, subpart H.
---------------------------------------------------------------------------

    \260\ USEPA, ``Final Technical Support Document for HWC MACT 
Standards, Volume V: Emission Estimates and Engineering Costs,'' 
Section 3, July 1999.
---------------------------------------------------------------------------

    Nationwide baseline HAP and particulate matter emissions from 
hazardous waste combustors are estimated to be approximately 12,650 
tons per year at the current baseline level of control. Depending on 
the number of facilities demonstrating compliance with health-based 
compliance alternatives for total chlorine, the total reduction of HAP 
and particulate matter for existing sources could be between 
approximately 2,260 and 3,380 tons per year. A discussion of the 
emission estimates methodology and results are presented in ``Technical 
Support Document for HWC MACT Replacement Standards, Volume V: Emission 
Estimates and Engineering Costs'' that is available in the docket.

    Table 1.--Nationwide Annual Emissions Reductions of HAP and Other
                               Pollutants
------------------------------------------------------------------------
                                                             Estimated
                                                             emission
                        Pollutant                           reductions
                                                             (tons per
                                                               year)
------------------------------------------------------------------------
Dioxin/furans\1\........................................            0.20
All HAP metals..........................................            19.5
Mercury.................................................            0.21
Semivolatile metals (Cd, Pb)............................             2.9
Low volatile metals (As, Be, Cr)........................             6.5
Other metals (Co, Mn, Ni, Sb, Se).......................             9.9
HCl and chlorine gas\2\.................................            1220
Particulate matter......................................          2,140
------------------------------------------------------------------------
\1\ Dioxin/furan emission reductions are expressed as grams TEQ per
  year.
\2\ We are promulgating health-based compliance alternatives for total
  chlorine for hazardous waste combustors other than hydrochloric acid
  production furnaces in lieu of the MACT technology-based emission
  standards (see Part Four, Section VII of the preamble for details).
  Given that a number of sources may elect to comply with the health-
  based compliance alternatives, the estimated reductions of total
  chlorine represent an upper bound estimate.

II. What Are the Water and Solid Waste Impacts?

    We estimate that water usage for existing sources will increase 
between 400 million and 1.6 billion gallons per year as a result of 
today's rule. The upper range estimate represents the water usage 
assuming no sources elect to comply with the health-based compliance 
alternatives for total chlorine, while the lower range estimate 
represents water usage assuming all sources elect the alternative. 
Water usage increases are estimated for reducing combustion gas 
temperatures with evaporated spray coolers for dioxin/furan control as 
well as for new particulate matter and acid gas air pollution control 
equipment. The increased water usage will also result in an increase in 
wastewater generation. Depending on the number of sources that elect to 
comply with the health-based compliance alternatives for total 
chlorine, we also estimate that up to 775 million gallons of wastewater 
may be generated.
    We estimate that the generation of solid waste will increase 
between approximately 8,700 tons and 12,200 tons per year depending on 
the number of sources that elect to comply with the health-based 
compliance alternatives for total chlorine. Of these totals, 
approximately 250 tons per year will be classified as hazardous waste 
subject to RCRA Subtitle C regulations. We estimate the remainder--
between 8,450 and 11,950 tons per year--will be classified and managed 
as a non-hazardous industrial waste subject to Subtitle D of RCRA. The 
costs associated with these disposal and water requirements are 
accounted for in the annualized compliance cost estimates. A discussion 
of the methodology used to estimate impacts is presented in ``Technical 
Support Document for HWC MACT Replacement Standards, Volume V: Emission 
Estimates and Engineering Costs'' that is available in the docket. We 
note that the nonair quality health and environmental impacts effects 
for both floor and beyond-the-floor options are discussed in the 
technical support document and are part of our consideration of such 
factors under section 112(d)(2).

III. What Are the Energy Impacts?

    We estimate that the national annual energy usage as a result of 
this rule will increase between approximately 73 million and 85 million 
kilowatt hours (kWh) depending on the number of sources that elect to 
comply with the health-based compliance alternatives for total 
chlorine. The increase results from the electricity required to operate 
air pollution control equipment installed to meet the standards. The 
increase energy usage costs are accounted for in the annualized 
compliance cost estimates. A discussion of the methodology used to 
estimate impacts is presented in ``Technical Support Document for HWC 
MACT Replacement Standards, Volume V: Emission Estimates and 
Engineering Costs.'' We note that the energy effects for both floor and 
beyond-the-floor options are discussed in the technical support 
document and are part of our consideration of such factors under 
section 112(d)(2).

IV. What Are the Control Costs?

    Control costs, as presented in this section, refer only to 
engineering, operation, and maintenance costs associated with unit/
system upgrades necessary to meet the final standards. These costs do 
not incorporate any market-based adjustments. All costs presented in 
this section are annualized estimates in 2002 dollars.

[[Page 59530]]

    We estimate there are a total of 267 sources \261\ that may be 
subject to requirements of this final rule. Of this total, there are 
116 boilers (104 liquid fuel boilers plus 12 solid fuel boilers), 92 
on-site incinerators, 25 cement kilns, 15 commercial incinerators, nine 
(or seven) lightweight aggregate kilns, and ten hydrochloric acid (HCl) 
production furnaces.
---------------------------------------------------------------------------

    \261\ For purposes of this discussion, a source is defined as 
the air pollution control system associated with one or more 
hazardous waste combustion unit(s). A facility may operate one or 
more sources. Note that this total includes two LWAK units limited 
by system burn constraints. Exclusion of these two units results in 
a total of 265 independent sources.
---------------------------------------------------------------------------

    Total national private sector engineering costs for the final 
standards are estimated at $40.2 million per year.\262\ This estimate 
reflects total non market adjusted upgrade costs (engineering, plus 
administrative and permitting), excluding chlorine control costs.\263\ 
All Phase II sources combined (liquid fuel boilers, coal fired boilers, 
and HCl production furnaces) represent 86 percent of this total. The 
average private sector engineering cost, excluding permitting and 
administrative, is projected to be highest for liquid fuel boilers, at 
$256,300 per source. Coal fired boilers are second at approximately 
$170,246 per source. Total engineering costs to cement kilns and HCl 
production furnaces are estimated to average $113,600, and $16,645 per 
source, respectively. Commercial incinerators are projected to 
experience engineering costs averaging $12,300 per source. On-site 
incinerators and LWAKs will face the lowest engineering costs at 
$10,200 and $3,330, respectively.
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    \262\ Not included here are total annual government costs. These 
costs, with or without chlorine control, are approximately $0.5 
million/year.
    \263\ We are finalizing the incorporation of section 112(d)(4) 
of the Clean Air Act to establish risk-based standards for total 
chlorine for hazardous waste combustors (except for hydrochloric 
acid production furnaces). The low-end of this cost range assumes 
all facilities emit total chlorine levels below risk-based levels of 
concern. Under this scenario, no total chlorine controls are assumed 
to be necessary. The total engineering cost with chlorine control is 
estimated at $46.7 million/year.]
---------------------------------------------------------------------------

    For all Phase I sources (141 sources; commercial incinerators, on-
site incinerators, cement kilns, and lightweight aggregate kilns), 
total average annualized non market-adjusted compliance costs 
(including permitting and administrative \264\) are estimated at 
$39,700 per source. The combined Phase II sources (126 sources; solid 
and liquid fuel-fired boilers and hydrochloric acid production 
furnaces) have total average annualized non market-adjusted compliance 
costs of approximately $274,500 per source. Across all sectors covered 
by today's rule (Phase I and Phase II sources), total annualized 
compliance costs were found to average $150,500 per source.
---------------------------------------------------------------------------

    \264\ See Exhibit 4-3 in the economic assessment background 
document.
---------------------------------------------------------------------------

    Private sector engineering costs (control) costs have also been 
assessed on a per ton (U.S.) basis. Captive energy recovery sources 
(solid and liquid fuel-fired boilers, and hydrochloric acid production 
furnaces) burned a total of 944,667 tons of hazardous waste in 2003. 
These facilities are projected to experience the highest average 
incremental control costs, at approximately $37 per ton of waste 
burned. Commercial energy recovery sources (cement kilns and LWAKs), 
burning an estimated 999,076 tons in 2003, are projected to experience 
average incremental control costs of approximately of $3.00 per ton. 
Captive (on-site) and commercial incinerators burn an estimated 925,828 
tons and 447,524 tons per year, respectively. These sources are 
estimated to experience average incremental engineering costs of $2.15 
per ton and $0.80 per ton, respectively.
    The aggregate control costs presented in this section do not 
reflect the anticipated real world cost burden on the economy. Any 
market disruption, such as the requirements in this final rule, will 
cause a short-term disequilibrium in the hazardous waste burning 
market, resulting in a natural economic process designed to reach the 
new market equilibrium. Actual cost impacts to society are more 
accurately measured by taking into account market adjustments in the 
targeted industry, plus secondary (societal) costs. Total market-
adjusted costs plus secondary costs are commonly termed Social Costs, 
and are generally less than total engineering costs due to efficiencies 
implemented during the market adjustment process. Social Costs 
theoretically represent the total real world costs of all goods and 
services society must give up in order to gain the added protection to 
human health and the environment. Social Costs are presented in Part VI 
of this Section.\265\
---------------------------------------------------------------------------

    \265\ Beyond-the-Floor standards were assessed for all floors. 
These findings are available in Appendix F and G of the engineering 
background document: See: Final Technical Support Document for HWC 
MACT Standards, Volume V--Emissions Estimates and Engineering Costs.
---------------------------------------------------------------------------

V. What Are the Economic Impacts?

    Economic impacts may be measured through several factors. This 
section presents estimated economic impacts relative to market exits, 
waste reallocations, and employment impacts. Economic impacts presented 
in this section are distinct from social costs, which correspond only 
to the estimated monetary value of market disturbances.

A. Market Exit Estimates

    The hazardous waste combustion industry operates in a dynamic 
market, with systems entering and exiting the market on a routine 
basis. Our analysis defines ``market exit'' as ceasing to burn 
hazardous waste. We have projected post-rule hazardous waste combustion 
system market exits based on economic feasibility only. Social, 
liability, and informational issues are not incorporated into our 
market exit analysis.
    Market exit estimates are derived from a breakeven analysis 
designed to determine system viability. This analysis is subject to 
several assumptions, including: Cost assumptions concerning the per 
sector baseline cost of hazardous waste burning, cost estimates for 
necessary pollution control devices (including operation and 
maintenance), prices for combustion services, and estimated waste 
quantities burned at these facilities. It is important to note that, 
for most sectors, exiting the hazardous waste combustion market is not 
equivalent to closing a plant. (Actual plant closure may occur only in 
the case of a commercial incinerator closing all systems.)
    We estimate that 39 systems, representing about 15 percent of the 
total affected universe, may stop burning hazardous waste in response 
to the final standards. Approximately 59,000 tons of hazardous waste 
may be diverted from these closed systems.
    These estimates assume no chlorine controls are put in place as a 
direct result of the rule.\266\ Of the estimated 39 market exits, 26 
are projected to be on-site incinerators and 8 are liquid fuel boilers. 
Three commercial incinerator systems may exit the market in response to 
the final rule. However, these systems are considered economically 
marginal in the baseline. Two coal-fired boiler systems are also 
projected to exit the market. No cement kilns, lightweight aggregate 
kilns, or HCl production furnaces are projected to exit the market as a 
result of the final rule. Market exit estimates were found to be 
identical

[[Page 59531]]

when the cost of chlorine control is included in the model.
---------------------------------------------------------------------------

    \266\ Even though we are allowing sources (except hydrochloric 
acid production furnaces) to invoke Sec.  112(d)(4) in lieu of MACT 
chlorine control requirements, we have not attempted to estimate the 
following: (1) The total number of sources that may elect to 
implement this provision, and, (2) what level of control may be 
necessary following a Sec.  112(d)(4) risk-based determination, 
since this would vary on a site-by-site basis.
---------------------------------------------------------------------------

B. Waste Reallocations

    Some on-site combustion systems (sources) may no longer be able to 
cover their hazardous waste burning costs as a result of final rule 
requirements. These sources are projected to divert or reroute their 
wastes to different hazardous waste combustion sources (usually some 
type of commercial unit).\267\ For multiple system facilities, this 
diversion may include on-site (non-commercial) waste consolidation 
among fewer systems at the same facility. Under current market 
conditions, non-combustion alternatives are generally not economically 
feasible, and in any case, would normally be unable to achieve the RCRA 
Land Disposal Restriction Treatment standards, which are based on the 
performance of combustion technology (which optimizes destruction of 
organic HAP).
---------------------------------------------------------------------------

    \267\ This analysis includes the cost of waste transport to 
alternative combustion sources, burning fees, and purchase of 
alternative fuels (if appropriate).
---------------------------------------------------------------------------

    As mentioned above, our economic model indicates that approximately 
59,000 tons (U.S.) of hazardous waste may be reallocated. This figure 
represents approximately 1.8 percent of the total 2003 quantity of 
hazardous waste burned at all sources. On-site consolidations account 
for nearly 24 percent (13,915 tons) of all diverted waste. Commercial 
incinerators are projected to receive the vast majority (42,722 tons, 
or 73 percent) of all off-site waste reallocations. Cement kilns and 
LWAKs are projected to receive the remaining reallocation (2,289 tons). 
Currently, there is more than adequate capacity to accommodate all off-
site hazardous waste diversions.

C. Employment Impacts

    Today's rule is projected to induce employment shifts across all 
affected sectors. These shifts may occur as specific combustion 
facilities find it no longer economically feasible to keep all of their 
systems running, or to stay in the hazardous waste market at all. When 
this occurs, workers at these locations may lose their jobs or 
experience forced relocations. At the same time, the rule is projected 
to result in positive employment impacts, as new purchases of pollution 
control equipment stimulate additional hiring in the pollution control 
manufacturing sector, and as additional staff are required at selected 
combustion facilities to accommodate reallocated waste and/or various 
compliance activities.
1. Employment Impacts--Dislocations (Losses)
    Employment dislocations in the combustion industry are projected to 
occur when facilities consolidate waste into fewer systems, or when a 
facility exits the hazardous waste combustion market altogether. 
Operation and maintenance labor hours are expected to be reduced for 
each system that stops burning hazardous waste. For each facility that 
completely exits the market, employment dislocations may also include 
supervisory and/or administrative personnel.
    Total employment dislocations resulting from implementation of the 
final standards are estimated at 310 full-time-equivalent (FTE) jobs. 
On-site incinerators account for about 62 percent of this total, 
followed by commercial incinerators (about 24 percent), and liquid-fuel 
boilers (about 12 percent). The large number of on-site incinerators 
drives the impacts within this sector.
2. Employment Impacts--Positive
    In addition to employment dislocations, our analysis indicates that 
today's rule may also result in positive employment impacts. These 
positive impacts are projected to occur to both the air pollution 
control industry and to combustion firms as they hire personnel to 
accommodate reallocated waste and/or comply with the various 
requirements of the rule. Hazardous waste combustion sources are 
projected to need additional operation and maintenance personnel for 
the new pollution control equipment and other compliance activities, 
such as new reporting and record keeping requirements.
    The total annual positive employment impact associated with the 
final standards is estimated at 323 FTEs. Positive employment impacts 
to the air pollution control industry \268\ are projected at 93 FTEs, 
or about 29 percent of this total. At 183 jobs, liquid-fuel boilers are 
projected to experience the greatest positive employment impact among 
all combustors.
---------------------------------------------------------------------------

    \268\ Manufacturers and distributors of air pollution control 
devices are projected to increase sales as a result of this action.
---------------------------------------------------------------------------

    While it may appear that our analysis suggests overall net positive 
employment impacts, such a conclusion would be inappropriate. Because 
the positive employment impacts and employment dislocations occur in 
different sectors of the economy, they should not be added together. 
Doing so would mask important distributional effects of the rule. In 
addition, these employment estimates reflect within sector impacts only 
and therefore do not account for potential displacements across 
sectors. This may occur if investment funds are diverted from other 
areas of the larger economy.

VI. What Are the Social Costs and Benefits of the Final Rule?

    The value of any regulatory action is traditionally measured by the 
net change in social welfare that it generates. Our economic assessment 
conducted in support of today's final rule evaluated compliance 
(control) costs, and economic impacts, as discussed above. The 
Assessment also analyzed social costs, benefits, small entity impacts, 
and other impacts (e.g., children's health, unfunded mandates). To 
conduct this analysis, we examined the current combustion market and 
practices, developed and implemented a methodology for examining 
compliance and social costs, applied an economic model to analyze 
industry economic impacts (discussed above), examined benefits, and 
followed appropriate guidelines and procedures for examining equity 
considerations, children's health, and other impacts. The data applied 
in this analysis were the most recently available at the time of the 
analysis. Because our data were limited, the findings from these 
analyses should be more accurately viewed as national estimates.

A. Combustion Market Overview

    The hazardous waste industry consists of three key segments: 
hazardous waste generators, fuel blenders/intermediaries, and hazardous 
waste burners. Hazardous waste is combusted at four main types of 
facilities: commercial incinerators, on-site incinerators, waste 
burning kilns (cement kilns and lightweight aggregate kilns), and 
industrial boilers. Commercial incinerators are generally larger in 
size and designed to manage virtually all types of solids, as well as 
liquid wastes. On-site incinerators are more often designed as liquid-
injection systems that handle liquids and pumpable solids. Waste 
burning kilns and boilers generally burn hazardous wastes to generate 
heat and power for their manufacturing processes.
    As discussed above, we have identified a total of 267 hazardous 
waste burning sources (systems) currently in operation in the United 
States. Liquid fuel-boilers account for 104 sources, followed by on-
site incinerators at 92 sources. Cement kilns, hydrochloric acid 
production furnaces, and commercial incinerators account for 25, 10, 
and 15 sources, respectively. Solid

[[Page 59532]]

fuel boilers and lightweight aggregate kilns make up the remainder, at 
12 and nine systems, respectively. These 267 sources are operated at a 
total of 145 different facilities. A single facility may have one or 
more combustion systems. Facilities with multiple systems may have 
different types of hazardous waste burning units. Combustion systems 
operating at chemical manufacturing facilities (NAICS 325) were found 
to account for about 70 percent of the total number of facilities and 
manage about 58 percent of all hazardous waste burned in 2003.
    The EPA Biennial Reporting System (BRS) reports a total demand for 
all combusted hazardous waste, across all facilities, at 3.32 million 
tons (U.S. ton) in 2003. Commercial energy recovery (cement kilns and 
lightweight aggregate kilns) burned about 30 percent of this total. 
Hazardous waste destruction at on-site incinerators and commercial 
incinerators accounted for 28 percent and 13 percent, respectively. 
Captive energy recovery accounted for the remainder, at 29 percent of 
the total.
    About 65 percent of all hazardous waste burned in 2003 was organic 
liquids. This is followed by solids (14 percent), inorganic liquids (11 
percent), and sludges (10 percent). Hazardous gases were found to 
represent a negligible portion, at about 0.08 percent of the total 
quantity burned in 2003. In terms of hazardous waste generating 
sources, the Basic Organic Chemical Manufacturing e sector (NAICS 325) 
generated approximately 32 percent of all hazardous waste burned in 
2001, followed by pesticides and agricultural chemicals, business 
services, organic fibers, medicinal chemicals, pharmaceuticals, 
plastics materials and resins, petroleum, and miscellaneous.
    Companies that generate large quantities of uniform hazardous 
wastes generally find it more economical and efficient to combust these 
wastes on-site using their own noncommercial systems. Commercial 
incineration facilities manage a wide range of hazardous waste streams 
generated in small to medium quantities by diverse industries. Cement 
kilns, lightweight aggregate kilns, and boilers derive heat and energy 
by burning high-Btu (solvents and organics) liquid hazardous 
wastes.\269\ Sometimes these wastes are blended with fossil fuels where 
system operators choose to not derive all of their energy input from 
hazardous waste.
---------------------------------------------------------------------------

    \269\ Many cement kilns are also able to burn a certain level of 
non liquid waste.
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    Regulatory requirements, liability concerns, and economics 
influence the demand for hazardous waste combustion services. 
Regulatory forces influence the demand for combustion by mandating 
certain hazardous waste treatment standards (land disposal restriction 
requirements, etc.). Liability concerns of waste generators affect 
combustion demand because combustion, by destroying organic wastes, 
greatly reduces the risk of future environmental problems. Finally, if 
alternative waste management options are more expensive, hazardous 
waste generators will likely choose to send their wastes to combustion 
facilities in order to increase overall profitability.
    Throughout much of the 1980s, hazardous waste combustors enjoyed a 
strong competitive position and generally maintained a high level of 
profitability. During this period, EPA regulations helped stimulate a 
greatly expanded market. In addition, federal permitting requirements, 
as well as powerful local opposition to siting of new incinerators, 
constrained the entry of new combustion systems. As a result, 
combustion prices rose steadily, ultimately reaching record levels in 
1987. The high profits of the late 1980s induced many firms to enter 
the market, in spite of the difficulties and delays anticipated in the 
permitting and siting process.
    Hazardous waste markets have changed significantly since the late 
1980s. In the early 1990s, substantial overcapacity resulted in fierce 
competition, declining prices, poor financial performance, numerous 
project cancellations, system consolidations, and facility closures. 
Since the mid 1990s, several additional combustion facilities have 
closed, while many of those that have remained open have consolidated 
their operations. Available (prior to this final rule) excess 
commercial capacity is currently estimated at about 21 percent of the 
total 2003 quantity combusted.

B. Baseline Specification

    Proper and consistent baseline specification is vital to the 
accurate assessment of incremental costs, benefits, and other economic 
impacts associated with today's rule. The baseline essentially 
describes the world absent the rule. The incremental impacts of today's 
rule are evaluated by predicting post MACT compliance responses with 
respect to the baseline. The baseline, as applied in this analysis, is 
the point at which today's rule is promulgated. Thus, incremental cost 
and economic impacts are projected beyond the standards established in 
the February 13, 2002 Interim Standards Final Rule.

C. Analytical Methodology and Findings--Social Cost Analysis

    Total social costs include the value of resources used to comply 
with the standards by the private sector, the value of resources used 
to administer the regulation by the government, and the value of output 
lost due to shifts of resources away from the current market 
equilibrium. To evaluate these shifts in resources and changes in 
output requires predicting changes in behavior by all affected parties 
in response to the regulation, including responses of directly-affected 
entities, as well as indirectly-affected private parties.
    For this analysis, social costs are grouped into two categories: 
Economic welfare (changes in consumer and producer surplus), and 
government administrative costs. The economic welfare analysis 
conducted for today's rule uses a simplified partial equilibrium 
approach. In this analysis, changes in economic welfare are measured by 
summing the changes in consumer and producer surplus. This simplified 
approach bounds potential economic welfare losses associated with the 
rule by considering two scenarios: Compliance costs assuming no market 
adjustments, and market adjusted compliance costs.
    The annualized private sector compliance (engineering) costs of 
$40.2 million, as presented in Section IV, assume no market 
adjustments. Our best estimate of total social costs incorporates 
rational market adjustments and all government costs. Under this 
scenario, increased compliance (engineering) costs are examined in the 
context of likely incentives hazardous waste combustion facilities have 
to continue burning, and the competitive balance in the market.
    Total annualized market-adjusted net private-sector costs are 
estimated at $22.1 million. \270\ In addition to the net private sector 
costs, total annual government costs are approximately $0.50 million. 
Thus, our best estimate of total social costs of this final rule is 
$22.6 million per year.
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    \270\ We are finalizing alternative risk-based total chlorine 
standards for hazardous waste combustors (ecept for hydrochloric 
acid production furnaces). The net private sector costs of $22.1 
million/year may be considered a lower-bound estimate that assumes 
facilities emit total chlorine (TCI) below risk-based levels of 
concern (i.e., no TCI controls are assumed to be necessary). Total 
net private sector market-adjusted costs would increase to 
approximately $28.1 million per year if we were to assume all 
sources were to comply with technology-based TCI standards (as 
opposed to the risk-based standards).
---------------------------------------------------------------------------

    The $22.1 million figure incorporates a net gain to selected Phase 
I sources and an estimated $3.6 million cost

[[Page 59533]]

(price) increase to pre-existing customers of commercial hazardous 
waste combustion facilities. On-site incinerators are projected to 
experience total market-adjusted cost increases of approximately $1.5 
million/year. All phase II sources account for approximately $31.9 
million in increased costs. Our economic model indicates that, of the 
Phase I source categories, commercial incinerators, cement kilns, and 
LWAKs would experience net gains following all market adjustments. The 
total net gain for these three source categories is estimated at $14.8 
million per year. Commercial incinerators would receive about 98 
percent of the total gain ($14.5 million/year). Gains to commercial 
facilities occur due to marginally higher prices, increased waste 
receipts, and relatively low upgrade costs, when compared to the other 
sources.

D. Analytical Methodology and Findings--Benefits Assessment

    This section discusses the monetized and non monetized benefits to 
human health and the environment potentially associated with today's 
final rule. Monetized human health benefits are derived from reductions 
in particulate matter (PM) and dioxin/furan exposure, and are based on 
a Value of Statistical Life (VSL) estimate of $6.2 million. \271\ Non 
monetized benefits are associated with human health, ecological, and 
waste minimization factors.
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    \271\ Monetized benefits associated with avoided premature 
mortality reflect a VSL range of $1.1 million to $11.4 million, with 
a central VSL estimate of $6.2 million. These values are derived 
from willingness-to-pay based VSL estimates presented in U.S. EPA, 
Regulatory Impact Analysis for the Final Clean Air Interstate Rule, 
March 2005.
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1. Monetized Benefits
    Total monetized human health benefits for the final standards are 
estimated to range from $5.61 million/year to $6.31 million/year. This 
estimate includes human health benefits associated with avoided PM and 
dioxin/furans exposure. The range is driven by alternative discount 
rate assumptions (no discount rate, 3 percent, or 7 percent) for 
mortality valuation. PM benefits represent 99 percent of the total 
monetized human health benefits.

Particulate Matter

    Results from our risk assessment extrapolation procedure \272\ are 
used to evaluate incremental human health benefits potentially 
associated with particulate matter emission reductions from hazardous 
waste combustion facilities. This analysis applied avoided human health 
benefits factors from the March 2004 Assessment document,\273\ combined 
with more recent emissions estimates for particulate matter.
---------------------------------------------------------------------------

    \272\ Inferential Risk Analysis in Support of Standards for 
Emissions of Hazardous Air Pollutants from Hazardous Waste 
Combustors.
    \273\ Assessment of the Potential Costs, Benefits, and Other 
Impacts of the Hazardous Waste Combustion MACT Replacement 
Standards: Proposed Rule, March 2004 (Chapter 6), and Addendum to 
the Assessment.
---------------------------------------------------------------------------

    Reduced PM emissions are estimated to result in monetized human 
health benefits of approximately $6.29 million per year. This is an 
undiscounted figure. Avoided PM morbidity cases account for $3.42 
million of this total, and include: respiratory illness, cardiovascular 
disease, chronic bronchitis, work loss days, and minor restricted 
activity. Chronic bronchitis accounts for approximately 89 percent of 
the total value of avoided PM morbidity cases. All morbidity cases are 
assumed to be avoided within the first year following reduced PM 
emissions and are not discounted under any scenario.
    Avoided premature deaths (mortality) are valued at $2.87 million 
per year, undiscounted. Assuming a discount rate of three and seven 
percent, PM mortality benefits would be $2.52 million and $2.19 
million, respectively. Our discounted analysis of PM mortality benefits 
assumes that 30 percent of premature mortalities occur during the first 
year, 50 percent occur evenly from the second through the fifth years, 
and the remaining 20 percent occur evenly from the sixth through the 
twentieth years.\274\ Due to limitations in the risk analysis, this 
assessment of PM benefits does not consider corresponding health 
benefits associated with the reduction of HAP metals carried by the PM.
---------------------------------------------------------------------------

    \274\ See: U.S. EPA. March 2005. Regulatory Impact Analysis for 
the Final Interstate Air Quality Rule.
---------------------------------------------------------------------------

    Dioxin/furan--Dioxin/furan emissions are projected to be reduced by 
a total of 0.2 grams per year under the final standards. In the July 
23, 1999 Addendum to the Assessment, cancer risk reductions linked to 
consumption of dioxin-contaminated agricultural products accounted for 
the vast majority of the 0.36 cancer cases per year that were expected 
to be avoided due to the 1999 standards. Cancer risk reductions 
associated with the final standards are expected to be less than 0.36 
cases per year, but greater than zero.
    At this time, the Agency is still using a cancer risk slope factor 
of 1.56 x 10<SUP>5</SUP> [mg/kg/day]<SUP>-1</SUP> for dioxin. This 
cancer slope factor is derived from the Agency's 1985 health assessment 
document for polychlorinated dibenzo-p-dioxins \275\ and represents an 
upper bound 95th percentile confidence limit of the excess cancer risk 
from a lifetime exposure. For the past several years the Agency has 
been conducting a reassessment of the human health risks associated 
with dioxin and dioxin-like compounds. In October of 2004 this 
reassessment \276\ was delivered to the National Academy of Sciences 
(NAS) for review.
---------------------------------------------------------------------------

    \275\ USEPA, 1985. Health Assessment Document for 
Polychlorinated Dibenzo-p-Dioxins. EPA/600/8-84/014F. Final Report. 
Office of Health and Environmental Assessment. Washington, DC. 
September, 1985.
    \276\ U.S.EPA. Exposure and Human Health Reassessment of 
2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) and Related Compounds 
National Academy Sciences (NAS) Review Draft, December 2003. [Note: 
Toxicity risk factors presented in this document should not be 
considered EPA's official estimate of dioxin toxicity, but rather 
reflect EPA's ongoing effort to reevaluate dioxin toxicity].
---------------------------------------------------------------------------

    Evidence compiled from this draft reassessment indicates that the 
carcinogenic effects of dioxin/furans may be six times as great as 
believed in 1985, reflecting an upper bound cancer risk slope factor of 
1 x 10<SUP>6</SUP> [mg/kg/day]<SUP>-1</SUP> for some individuals. 
Agency scientists' more likely (central tendency) estimates (derived 
from the ED<INF>01</INF> rather than the LED<INF>01</INF>) result in 
slope factors and risk estimates that are within 2-3 times of the upper 
bound estimates (i.e., between 3 x 10<SUP>5</SUP> [mg/kg/
day]<SUP>-1</SUP> and 5 x 10\5\ [mg/kg/day]<SUP>-1</SUP>) based on the 
available epidemiological and animal cancer data. However, risks could 
be as low as zero for some individuals. Use of the alternative upper 
bound cancer risk slope factor could result in a higher human health 
monetized health benefit associated with premature cancer deaths 
avoided in response to the final standard for dioxin/furans. The 
assessment of upper bound cancer risk using this alternative slope 
factor should not be considered current Agency policy. The standards 
for dioxin in today's final rule were not based on this draft 
reassessment.
    Total non-discounted human health benefits associated with 
projected dioxin reductions are estimated at $0.02 million/year. These 
benefits may range from $0.01 million/year to nearly zero, applying a 
discount rate of 3 percent and 7 percent, respectively. Our discounted 
estimates incorporate an assumed latency period of 21 and 34 years from 
exposure to death.
2. Non-Monetized Benefits
    We examined, but did not monetize human health benefits potentially 
associated with reduced exposure to lead, mercury, and total chlorine. 
Non monetized ecological benefits

[[Page 59534]]

potentially associated with reductions in dioxin/furan; selected 
metals, total chlorine, and particulate matter were also examined. 
Finally, waste minimization is examined as a non-monetized benefit.
    Lead--The final standards are expected to reduce lead emissions by 
approximately 2.5 tons per year. In comparison, the 1999 standards were 
expected to reduce lead emissions by 89 tons per year, and were 
expected to reduce cumulative lead exposures for two children, ages 
zero to five, to less than 10 [mu]g/dL. The lead benefits associated 
with these final standards are therefore expected to be modest. The 
final standards will also result in reduced lead levels for children of 
sub-populations with especially high levels of exposure. Children of 
subsistence fishermen, commercial beef farmers, and commercial dairy 
farmers who face the greatest levels of cumulative lead exposure may 
also experience comparable reductions in overall exposure as a result 
of the MACT standards.
    Mercury--The HWC MACT final standards are expected to reduce 
mercury emissions by approximately 0.21 tons per year, approximately 93 
percent less than the four-ton reduction expected under the 1999 
Standards. We do not attempt to quantify the mercury-related benefits 
associated with today's final standards. However, because the reduction 
in mercury emissions represents a fraction of the reduction expected 
under the 1999 Standards, the mercury-related benefits of the final 
standards are likely to be less than the corresponding benefits under 
the 1999 Standards.
    To characterize the benefits associated with reduced mercury 
emissions, the 1999 Assessment measured changes in hazard quotients for 
populations living near hazardous waste combustion facilities. For any 
given population, the hazard quotient is the ratio of the actual level 
of exposure to a safe level of exposure. A hazard quotient greater than 
one implies that a population is potentially at risk. The exposure 
quotient analysis in the 1999 Assessment found that the measurable 
benefits of reduced mercury emissions under the 1999 Standards were 
likely to be small because baseline exposures were relatively low. In 
addition, many of the studies examining the adverse health effects of 
mercury are inconclusive. Over the past several years, however, 
scientists have conducted three large-scale studies of individuals in 
the Faroe Islands, New Zealand, and the Seychelles Islands examining 
the relationship between mercury exposure in women and the neuro-
development of their unborn children.\277\ The New Zealand and Faroe 
Islands studies both found a statistically significant relationship 
between maternal methylmercury exposure and IQ decrements in the unborn 
children of these women. In its 2000 report on the toxicological 
effects of methylmercury, the National Research Council suggested that 
integrating the results of all three studies could be useful for risk 
assessment purposes.\278\ Such an integrative risk assessment, later 
published by Ryan et al. in 2005, served as the basis of the Agency's 
health effects analysis for the Clean Air Mercury Rule (CAMR).\279\ The 
regulatory impact analysis for CAMR summarizes several of the adverse 
health effects that may be linked to mercury and reviews the 
epidemiological literature examining the link between these effects and 
exposure to mercury.\280\
---------------------------------------------------------------------------

    \277\ Grandjean, P., K. Murata, E. Budtz-Jorgensen, and P. 
Weihe. 2004. ``Autonomic Activity in Methylmercury Neurotoxicity: 
14-Year Follow-Up of a Faroese Birth Cohort.'' Journal of 
Pediatrics.144:169-76; Kjellstrom, T., P. Kennedy, S. Wallis, A. 
Stewart, L. Friberg, B. Lind, P. Witherspoon, and C. Mantell. 1989. 
Physical and mental development of children with prenatal exposure 
to mercury from fish. Stage 2: Interviews and psychological tests at 
age 6. National Swedish Environmental Protection Board Report No. 
3642; Crump, K.S., T. Kjellstrom, A.M. Shipp, A. Silvers, and A. 
Stewart. 1998. ``Influence of prenatal mercury exposure upon 
scholastic and psychological test performance: benchmark analysis of 
a New Zealand cohort.'' Risk Analysis. 18(6):701-713; Davidson, 
P.W., G.J. Myers, C. Cox, C. Axtell, C. Shamlaye, J. Sloane-Reeves, 
E. Cernichiari, L. Needham, A. Choi, Y. Wang, M. Berlin, and T.W. 
Clarkson. 1998. ``Effects of prenatal and postnatal methylmercury 
exposure from fish consumption on neurodevelopment: outcomes at 66 
months of age in the Seychelles Child Development Study.'' Journal 
of the American Medical Association. 280(8):701-707; and Myers, 
G.J., P.W. Davidson, C. Cox, C.F. Shamlaye, D. Palumbo, E. 
Cernichiari, J. Sloane-Reeves, G.E. Wilding, J. Kost, L.S. Huang, 
and T.W. Clarkson. 2003. ``Prenatal methylmercury exposure from 
ocean fish consumption in the Seychelles child development study.'' 
Lancet. 361(9370):1686-92.
    \278\ National Research Council of the National Academy of 
Sciences, Toxicological Effects of Methylmercury. 2000, p. 299.
    \279\ Ryan, L.M. Effects of Prenatal Methylmercury on Childhood 
IQ: A Synthesis of Three Studies. Report to the U.S. Environmental 
Protection Agency, 2005; U.S. EPA. Regulatory Impact Analysis of the 
Clean Air Mercury Rule: Final Report. March 2005.
    \280\ U.S. EPA. Regulatory Impact Analysis of the Clean Air 
Mercury Rule: Final Report. March 2005.
---------------------------------------------------------------------------

    Total Chlorine--We were not able to quantify the benefits 
associated with reductions in total chlorine emissions. Total chlorine 
is a combination of hydrogen chloride and chlorine gas. The final 
standards are projected to reduce total annual chlorine emissions by 
about 107 tons per year \281\ (HCl production furnaces only). Hydrogen 
chloride is corrosive to the eyes, skin, and mucous membranes. Acute 
inhalation can cause eye, nose, and respiratory tract irritation and 
inflammation, and pulmonary edema. Chronic occupational inhalation has 
been reported to cause gastritis, bronchitis, and dermatitis in 
workers. Long term exposure can also cause dental discoloration and 
erosion. Chlorine gas inhalation can cause bronchitis, asthma and 
swelling of the lungs, headaches, heart disease, and meningitis. Acute 
exposure causes more severe respiratory and lung effects, and can 
result in fatalities in extreme cases. The exposure levels established 
under 112(d)(4) are expected to reduce chlorine exposure for people in 
close proximity to hazardous waste combustion facilities, and are 
therefore likely to reduce the risk of all associated health effects.
    Ecological Benefits--We examined ecological benefits through a 
comparison of the 1999 Assessment and today's final standards. 
Ecological benefits in the 1999 Assessment were based on reductions of 
approximately 100 tons per year in dioxin/furans and selected metals. 
Lead was the only pollutant of concern for aquatic ecosystems, while 
mercury appeared to be of greatest concern for terrestrial ecosystems. 
Dioxin/furan and lead emission reductions also provided some potential 
benefits for terrestrial ecosystems. The final standards are expected 
to reduce dioxin/furan and selected metal emissions by about 12 percent 
to 13 percent of the 1999 estimate, resulting in fewer incremental 
benefits than those estimated for the 1999 Assessment (and later, for 
the 2002 Interim Standards). However, the 1999 Assessment did not 
estimate the ecological benefits of MACT standards for hazardous waste 
burning industrial boilers and HCl production furnaces. These systems 
were excluded from the universe in 1999 but are part of the universe 
addressed by today's final standards. As a result, while the total 
ecological benefits of the final rule are likely to be modest, areas 
near facilities with boilers may enjoy more significant ecological 
benefits under the final standards than areas near facilities that have 
already complied with the 2002 Interim standards.
---------------------------------------------------------------------------

    \281\ This is a lower bound estimate that assumes all other 
sources will implement 112(d)(4) and will not move to reduce TCl 
emissions from current baseline levels.
---------------------------------------------------------------------------

    Mercury, lead, and chlorides are among the HAPs that can cause 
damage to the health and visual appearance of

[[Page 59535]]

plants.\282\ While the total value of forest health is difficult to 
estimate, visible deterioration in the health of forests and plants can 
cause a measurable change in recreation behavior. Several studies that 
measure the change in outdoor recreation behavior according to forest 
health have attempted to place a value on aesthetic degradation of 
forests.\283\ Although these studies are available, additional research 
is needed to fully understand the effects of these Haps on the forest 
ecosystem. Thus, these benefits are not quantified in this analysis.
---------------------------------------------------------------------------

    \282\ Although the primary pollutants which are detrimental to 
vegetation aesthetics and growth are tropospheric ozone, sulfur 
dioxide, and hydrogen fluoride (three pollutants which are not 
regulated in the MACT standards), some literature exists on the 
relationship between metal deposition and vegetation health. 
(Mercury Study Report to Congress Volume VI, 1997) (Several studies 
are cited in this report.)
    \283\ See, for example, Brown, T.C. et al. 1989, Scenic Beauty 
and Recreation Value: Assessing the Relationship, In J. Vining, ed., 
Social Science and Natural Resources Recreation Management, Westview 
Press, Boulder, Colorado; this work studies the relationship between 
forest characteristics and the value of recreational participation. 
Also see Peterson, D.G. et al. 1987, Improving Accuracy and Reducing 
Cost of Environmental Benefit Assessments. Draft Report to the U.S. 
EPA, by Energy and Resource Consultants, Boulder, Colorado; Walsh et 
al. 1990, Estimating the public benefits of protecting forest 
quality, Journal of Forest Management, 30:175-189., and Homes et al. 
1992, Economic Valuation of Spruce-Fir Decline in the Southern 
Appalachian Mountains: A comparison of Value Elicitation Methods. 
Presented at the Forestry and the Environment: Economic Perspectives 
Conference, March 1, 1992 Jasper, Alberta, Canada for estimates of 
the WTP of visitors and residents to avoid forest damage.
---------------------------------------------------------------------------

    Emissions that are sufficient to cause structural and aesthetic 
damage to vegetation are likely to affect growth as well. Little 
research has been done on the effects of compounds such as chlorine, 
heavy metals (as air pollutants), and PM on agricultural 
productivity.\284\ Even though the potential for visible damage and 
production decline from metals and other pollutants suggests the final 
standards could increase agricultural productivity, we have not 
monetized the benefits of these changes.
---------------------------------------------------------------------------

    \284\ MacKenzie, James J., and Mohamed T. El-Ashry, Air 
Pollution's Toll on Forests and Crops (New Haven, Yale University 
Press, 1989).
---------------------------------------------------------------------------

3. Waste Minimization Benefits
    Facilities that burn hazardous waste and remain in operation 
following implementation of the final standards are expected to 
experience marginally increased costs as a result of these standards. 
This will result in an incentive to pass these increased costs on to 
their customers in the form of higher combustion prices. In the 1999 
Assessment we conducted a waste minimization analysis to inform the 
expected price change. The analysis concluded that the demand for 
hazardous waste combustion is relatively inelastic. While a variety of 
waste minimization alternatives are available for managing hazardous 
waste streams that are currently combusted, the costs of these 
alternatives generally exceed the cost of combustion. When the 
additional costs of compliance with the MACT standards are taken into 
account, waste minimization alternatives still tend to exceed the 
higher combustion costs. This relative inelasticity suggests that, in 
the short term, large reductions in the amount of hazardous waste 
requiring combustion are not likely to occur. However, over the longer 
term (i.e. as production systems are updated), companies may continue 
to seek alternatives to expensive hazardous waste-management. This may 
include process adjustments that result, to some degree in source 
reduction of hazardous waste and the increased generation of non 
hazardous waste. To the extent that increases in combustion prices 
provide additional incentive to adopt more efficient processes, the 
final standards may contribute to longer term process-based hazardous 
waste minimization efforts.
    No hazardous waste minimization impacts are captured in our 
quantitative analysis of costs and benefits.\285\ A quantitative 
assessment of the benefits associated with waste minimization may 
result in double-counting of some of the benefits described earlier. 
For example, waste minimization may reduce emissions of hazardous air 
pollutants and therefore have a positive effect on public health. 
Furthermore, emission reductions beyond those necessary for compliance 
with the final standards are not addressed in the benefits assessment. 
In addition, waste minimization is likely to result in specific types 
of benefits not captured in this Assessment. For example, waste 
generators that engage in waste minimization may experience a reduction 
in their waste handling costs and could also reduce the risk related to 
waste spills and waste management. Finally, waste minimization 
procedures potentially stimulated by today's action may result in 
additional costs to facilities that implement these technologies. These 
factors have not been assessed in our analysis but are likely to at 
least partially offset corresponding benefits.
---------------------------------------------------------------------------

    \285\ Note that this rule does, in fact, consider hazardous 
waste feed control. Feed control can be implemented by each source 
through waste minimization procedures. See: Final Technical Support 
Document for HWC MACT Standards, Volume V-Emissions Estimates and 
Engineering Costs.
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4. Conclusion
    Total non-discounted monetized human health benefits associated 
with the final standards are estimated at $6.31 million/year. 
Annualized discounted benefits were found to range from $5.61 million 
to $5.95 million/year. The range reflects an alternative discount rate 
of 3 percent and 7 percent for mortality benefits.
    It is important to emphasize that monetized benefits represent only 
a portion of the total benefits associated with this rule. A 
significant portion of the benefits are not monetized, as discussed 
above, due to data and analytical limitations. Specifically, ecological 
benefits, and human health benefits associated with reductions in 
chlorine, mercury, and lead are not quantified or monetized. In some 
regions these benefits may be significant. In addition, specific sub-
populations near combustion facilities, including children and minority 
populations, may be disproportionately affected by environmental risks 
and may therefore enjoy more significant benefits. Visibility benefits 
associated with reduced PM are also expected from this final rule. For 
a complete discussion of the methodology, data, findings, and 
limitations associated with our benefits analysis the reader is 
encouraged to review the Assessment document,\286\ and the Addendum to 
the Assessment.
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    \286\ Assessment of the Potential Costs, Benefits, and Other 
Impacts of the Hazardous Waste Combustion MACT Final Rule Standards. 
September 2005.
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Part Seven: How Does the Final Rule Meet the RCRA Protectiveness 
Mandate?

    As discussed in more detail below, we believe today's final 
standards are generally protective of human health and the environment. 
We therefore finalize and apply these standards, in most instances, in 
lieu of the RCRA air emission standards applicable to these sources.

I. Background

    Section 3004(a) of RCRA requires the Agency to promulgate standards 
for hazardous waste treatment, storage, and disposal facilities as 
necessary to protect human health and the environment. The standards 
for hazardous waste incinerators generally rest on this authority. In 
addition, Sec.  3004(q) requires the Agency to promulgate standards for 
emissions from facilities that burn

[[Page 59536]]

hazardous waste fuels (e.g., cement and lightweight aggregate kilns, 
boilers, and hydrochloric acid production furnaces) as necessary to 
protect human health and the environment. Using RCRA authority, the 
Agency has established emission (and other) standards for hazardous 
waste combustors that are either entirely risk-based (e.g., site-
specific standards for metals under the Boiler and Industrial Furnace 
rule), or are technology-based but determined by a generic risk 
assessment to be protective (e.g., the DRE standard for incinerators 
and BIFs).
    The MACT standards finalized today implement the technology-based 
regime of CAA Sec.  112(d). There is, however, a residual risk 
component to air toxics standards. Section 112(f) of the Clean Air Act 
requires the Agency to impose, within eight years after promulgation of 
the technology-based standards promulgated under Sec.  112(d) (i.e., 
the authority for today's final standards), additional controls if 
needed to protect public health with an ample margin of safety or to 
prevent adverse environmental effect.
    RCRA Sec.  1006(b) directs that EPA ``integrate all provisions of 
[RCRA] for purposes of administration and enforcement and * * * avoid 
duplication, to the maximum extent possible, with the appropriate 
provisions of the Clean Air Act * * * '' Thus, although considerations 
of risk are not ordinarily part of the MACT process, in order to avoid 
duplicative standards where possible, we have evaluated the 
protectiveness of the standards finalized today.
    As noted above, under RCRA, EPA must promulgate standards ``as may 
be necessary to protect human health and the environment.'' RCRA Sec.  
3004(a) and (q). Technology-based standards developed under CAA Sec.  
112 do not automatically satisfy this requirement, but may do so in 
fact. See 59 FR at 29776 (June 6, 1994) and 60 FR at 32593 (June 23, 
1995) (RCRA regulation of secondary lead smelter emissions unnecessary 
at this time given stringency of technology-based standard and pendency 
of Sec.  112(f) determination). If the MACT standards, as a factual 
matter, are sufficiently protective to also satisfy the RCRA mandate, 
then no independent RCRA standards are required. Conversely, if MACT 
standards are inadequate, the RCRA authorities would have to be used to 
fill the gap.

II. Evaluation of Protectiveness

    For the purpose of satisfying the RCRA statutory mandates, the 
Agency has conducted an evaluation of the degree of protection afforded 
by the MACT standards being finalized today. We have not conducted a 
comprehensive risk assessment for this rulemaking as was done for 
incinerators, cement kilns, and lightweight aggregate kilns in the 1999 
MACT rule where we concluded that the promulgated standards were 
generally protective and therefore, the RCRA standards need not be 
retained. However, we noted that in certain instances, permit 
authorities may invoke the omnibus authority (RCRA Sec.  3005(c)(3) and 
its implementing regulations at Sec.  270.10(k)) if there is some 
reason to believe that additional controls beyond those required 
pursuant to 40 CFR parts 63, 264, 265, and 266 may be needed to ensure 
protection of human health and the environment under RCRA.
    For this final rule, we instead compared the risk-related 
characteristics of the sources covered by the 1999 rule to the sources 
covered by today's rule (e.g., estimated emissions, stack 
characteristics, meteorology, and population). For a description of the 
methodology and technical discussion of its application, see 
``Inferential Risk Analysis in Support of Standards for Emissions of 
Hazardous Air Pollutants from Hazardous Waste Combustors,'' in the 
docket for today's rule. We performed a large array of statistical 
comparisons and from these we attempted to make inferences about 
whether risks would be expected to be about the same, less than, or 
greater than the risks estimated for 1999 rule. We think the 
comparative analysis lends additional support to our view that today's 
final standards are generally protective. We received no comments 
either in support of or in opposition to our use of the comparative 
analysis to evaluate the protectiveness of the standards being 
finalized today or our view that the standards are generally 
protective.
    While we regard the final standards as generally protective, the 
comparative analysis suggests some concern for solid fuel-fired boilers 
(SFBs) with regard to the particulate matter standard (and certain 
metals such as antimony and thallium), mercury, and total chlorine 
standards (other than the alternative risk-based chlorine standards). 
The analysis also suggests some concern for hydrochloric acid (HCl) 
production furnaces with regard to the dioxin/furan standard, where 
carbon monoxide and total hydrocarbon serve as surrogate control. 
However, because both SFBs and HCl production furnaces comprise such 
small source categories (4 SFB facilities and 8 HCl production 
facilities), it is difficult to reach firm conclusions. For example, 
for SFBs it was not possible to conduct hypothesis tests that could be 
considered valid involving correlations among variables for a number of 
variables in the analysis because of the small number of data points 
and the power of the tests to detect differences for those that were 
conducted was very low, which greatly diminishes the value of the 
results. (Indeed, no differences in correlations were found for SFBs at 
the 0.1 significance level--the level of significance that was used in 
the analysis.) Similarly, for HCl production furnaces the power of the 
tests to detect differences in correlations was quite low. It must be 
noted that the comparative analysis methodology was not intended for 
comparisons that involve relatively few facilities because it is 
grounded in tests of hypotheses and levels of statistical significance 
which generally require substantial amounts of data to produce firm 
conclusions. Nevertheless, in consideration of the indications of 
possible risks for the aforementioned standards, permit authorities may 
want to consider site-specific factors in determining whether or not 
the MACT standards are sufficiently protective for facilities that fall 
into these categories.
    The comparative analysis may also raise possible concerns for 
lightweight aggregate kilns (LWAKs) and liquid fuel-fired boilers 
(LFBs) with dry APCDs with regard to the dioxin/furan standards, in 
view of the ongoing uncertainty in cancer and other health effects 
levels for chlorinated dioxins and furans. In particular, some recent 
estimates of the carcinogenicity of these compounds that consider both 
human and animal data, are higher than earlier estimates derived from 
animal data alone. However, like SFBs and HCl production furnaces, 
LWAKs and LFBs with dry APCDs both comprise small source categories (3 
LWAK facilities and 7 dry APCD LFB facilities). This makes it very 
difficult to reach firm conclusions and suggests the need to consider 
site-specific factors in determining whether the MACT standards are 
sufficiently protective in these instances.
    Except as noted, we believe today's final standards provide a 
substantial degree of protection to human health and the environment. 
We therefore do not believe that we need to retain the existing RCRA 
standards for boilers and hydrochloric acid production furnaces (just 
as we found that existing RCRA standards for incinerators, cement 
kilns, and lightweight aggregate kilns were no longer needed after the 
1999 rule). However, as previously discussed in

[[Page 59537]]

more detail in Part Four, Section IX, site-specific risk assessments 
may be warranted on an individual source basis to ensure that the MACT 
standards provide adequate protection in accordance with RCRA.

Part Eight: Statutory and Executive Order Reviews

I. Executive Order 12866: Regulatory Planning and Review

    Under Executive Order 12866 [58 FR 51735 (October 4, 1993)] the 
Agency, in conjunction with OMB's Office of Information and Regulatory 
Affairs (OIRA), must determine whether a regulatory action is 
``significant'' and therefore subject to OMB review and the full 
requirements of the Executive Order. The Order defines ``significant 
regulatory action'' as one that is likely to result in a rule that may:
    (1) Have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local, or tribal governments or 
communities;
    (2) Create a serious inconsistency or otherwise interfere with an 
action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, grants, 
user fees, or loan programs or the rights and obligations of recipients 
thereof; or
    (4) Raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order.
    Pursuant to the terms of Executive Order 12866, it has been 
determined that this rule is a ``significant regulatory action'' 
because this action may raise novel legal or policy issues due to the 
methodology applied in development of the final standards. As such, 
this action was submitted to OMB for review. Changes made in response 
to OMB suggestions or recommendations are documented in the public 
record.
    The total social costs for this rule are estimated at $22.6 million 
per year \287\. This figure is significantly below the $100 million 
threshold established under point number one above. Thus, this rule is 
not considered to be an economically significant action. However, in an 
effort to comply with the spirit of the Order, we have prepared an 
economic assessment in support of today's final rule. This document is 
entitled: Assessment of the Potential Costs, Benefits, and Other 
Impacts of the Hazardous Waste Combustion MACT Final Rule Standards, 
September 2005. We have also prepared an Addendum to this Assessment 
entitled: Addendum to the Assessment of the Potential Costs, Benefits, 
and Other Impacts of the Hazardous Waste Combustion MACT Final Rule 
Standards, September 2005. This Addendum captures changes made to the 
rulemaking following completion of the full Assessment document. The 
Assessment and Addendum were designed to adhere to analytical 
requirements established under Executive Order 12866, and corresponding 
Agency and OMB guidance; subject to data, analytical, and resource 
limitations. Findings presented under Part Six of this Preamble were 
developed in accordance with this guidance. The RCRA docket established 
for today's rulemaking maintains a copy of the Assessment and Addendum 
for public review. Interested persons are encouraged to read both 
documents to gain a full understanding of the analytical methodology, 
findings, and limitations associated with this report.
---------------------------------------------------------------------------

    \287\ This figure includes approximately $0.5 million/year in 
total government costs. Total social costs would increase to 
approximately $28.6 million per year if we were to assume all 
sources were to comply with technology-based TC1 standards.
---------------------------------------------------------------------------

II. Paperwork Reduction Act

    We have prepared an Information Collection Request (ICR) document 
(ICR No. 1773.08) listing the information collection requirements of 
this final rule, and have submitted it for approval to the Office of 
Management and Budget (OMB) under the provisions of the Paperwork 
Reduction Act, U.S.C. 3501 et seq. OMB has assigned a control number 
2050-0171 for this ICR. This ICR is available for public viewing in the 
EPA Docket Center, Room B102, 1301 Constitution Avenue NW., Washington, 
DC. Copy may also be obtained from the EDOCKET on the EPA Web site, or 
by calling (202) 566-1744. The information collection requirements are 
not enforceable until OMB approves them.
    The public burden associated with this final rule is projected to 
affect 238 HWC units and is estimated to average 211 hours per 
respondent annually. The reporting and recordkeeping cost burden is 
estimated to average $5,640 per respondent annually.
    Burden means total time, effort, or financial resources expended by 
persons to generate, maintain, retain, disclose, or provide information 
to or for a Federal agency. That includes the time needed to review 
instructions; develop, acquire, install, and utilize technology and 
systems for the purposes of collecting, validating, and verifying 
information, processing and maintaining information, and disclosing and 
providing information; adjust the existing ways to comply with any 
previously applicable instructions and requirements; train personnel to 
be able to respond to a collection of information; search data sources; 
complete and review the collection of information; and transmit or 
otherwise disclose the information.
    An agency may not conduct or sponsor, and a person is not required 
to respond to, a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for EPA's 
regulations are listed in 40 CFR part 9. When this ICR is approved by 
OMB, the Agency will publish a technical amendment to 40 CFR part 9 in 
the Federal Register to display the OMB control number for the approved 
information collection requirements contained in this final rule.
    The EPA requested comments (see 70 FR 20748, Apr. 21, 2005) on the 
need for this information, the accuracy of the provided burden 
estimates, and any suggested methods for minimizing respondent burden, 
including through the use of automated collection techniques.

III. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) as amended by the Small 
Business Regulatory Enforcement Fairness Act of 1996 (SBREFA), 5 U.S.C. 
601 et seq., generally requires an agency to prepare a regulatory 
flexibility analysis of any rule subject to notice and comment 
rulemaking requirements under the Administrative Procedure Act, or any 
other statute. This analysis must be completed unless the agency is 
able to certify that the rule will not have a significant economic 
impact on a substantial number of small entities. Small entities 
include small businesses, small not-for-profit enterprises, and small 
governmental jurisdictions.
    The RFA provides default definitions for each type of small entity. 
Small entities are defined as: (1) A small business as defined by the 
Small Business Administration's (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; and (3) a small organization that is any not-for-
profit enterprise which is independently owned and operated and is not 
dominant in its field.
    After considering the economic impacts of today's final rule on 
small entities, I certify that this action will not

[[Page 59538]]

have a significant economic impact on a substantial number of small 
entities. We have determined that hazardous waste combustion facilities 
are not owned by small governmental jurisdiction or nonprofit 
organizations. Therefore, only small businesses were analyzed for small 
entity impacts. For the purposes of the impact analyses, small entity 
is defined either by the number of employees or by the dollar amount of 
sales. The level at which a business is considered small is determined 
for each North American Industrial Classification System (NAICS) code 
by the Small Business Administration.
    Affected individual waste combustors (incinerators, cement kilns, 
lightweight aggregate kilns, solid and liquid fuel-boilers, and 
hydrochloric acid production furnaces) will bear the impacts of today's 
rule. These units will incur direct economic impacts (positive or 
negative) as a result of today's rule. Few of the hazardous waste 
combustion facilities affected by this rule were found to be owned by 
small businesses, as defined by the Small Business Administration 
(SBA). From our universe of 145 facilities, we identified eight 
facilities that are currently owned by small businesses. Four of these 
facilities are liquid boilers, two are on-site incinerators, one is a 
cement kiln, and one is a lightweight aggregate kiln (LWAK). Our 
analysis indicates that none of these facilities are likely to incur 
annualized compliance costs greater than one percent of gross annual 
corporate revenues. Cost impacts of the final standards were found to 
range from less than 0.01 percent to 0.46 percent of annual gross 
corporate revenues.
    The reader is encouraged to review our regulatory flexibility 
screening analysis prepared in support of this determination. This 
analysis is incorporated as Appendix H of the Assessment document, and 
updated in the Addendum.

IV. Unfunded Mandates Reform Act of 1995

    Signed into law on March 22, 1995, the Unfunded Mandates Reform Act 
(UMRA) calls on all federal agencies to provide a statement supporting 
the need to issue any regulation containing an unfunded federal mandate 
and describing prior consultation with representatives of affected 
state, local, and tribal governments.
    Today's final rule is not subject to the requirements of sections 
202, 204 and 205 of UMRA. In general, a rule is subject to the 
requirements of these sections if it contains ``Federal mandates'' that 
may result in the expenditure by State, local, and tribal governments, 
in the aggregate, or by the private sector, of $100 million or more in 
any one year. Today's final rule does not result in $100 million or 
more in expenditures for any of these categories. The aggregate 
annualized social cost for today's rule is estimated at $22.6 million.

V. Executive Order 13132: Federalism

    Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August 
10, 1999), requires EPA to develop an accountable process to ensure 
``meaningful and timely input by State and local officials in the 
development of regulatory policies that have federalism implications.'' 
``Policies that have federalism implications'' is defined in the 
Executive Order to include regulations that have ``substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government.''
    Under Executive Order 13132, EPA may not issue a regulation that 
has federalism implications, that imposes substantial direct compliance 
costs, and that is not required by statute, unless the Federal 
government provides the funds necessary to pay the direct compliance 
costs incurred by State and local governments, or EPA consults with 
State and local officials early in the process of developing the 
regulation.
    This final rule does not have federalism implications. It will not 
have substantial direct effects on the States, on the relationship 
between the national government and the States, or on the distribution 
of power and responsibilities among the various levels of government, 
as specified in the Order. The rule focuses on requirements for 
facilities burning hazardous waste, without affecting the relationships 
between Federal and State governments. Thus, Executive Order 13132 does 
not apply to this rule. Although section 6 of Executive Order 13132 
does not apply to this rule, EPA did include various State 
representatives on our Agency workgroup. These representatives 
participated in the development of this rule.

VI. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    Executive Order 13175: Consultation and Coordination with Indian 
Tribal Governments (65 FR 67249, November 9, 2000), requires EPA to 
develop an accountable process to ensure ``meaningful and timely input 
by tribal officials in the development of regulatory policies that have 
tribal implications.'' Our Agency workgroup for this rule included 
Tribal representation. We have determined that this final rule does not 
have tribal implications, as specified in the Order. No Tribal 
governments are known to own or operate hazardous waste combustors 
subject to the requirements of this final rule. Furthermore, this rule 
focuses on requirements for all regulated sources without affecting the 
relationships between tribal governments in its implementation, and 
applies to all regulated sources, without distinction of the 
surrounding populations affected. Thus, Executive Order 13175 does not 
apply to this rule.

VII. Executive Order 13045: Protection of Children From Environmental 
Health Risks and Safety Risks

    Executive Order 13045: ``Protection of Children from Environmental 
Health Risks and Safety Risks'' (62 FR. 19885, April 23, 1997) applies 
to any rule that: (1) Is determined to be ``economically significant'' 
as defined under E.O. 12866, and (2) concerns an environmental health 
or safety risk that EPA has reason to believe may have a 
disproportionate effect on children. If the regulatory action meets 
both criteria, the Agency must evaluate the environmental health or 
safety effects of the planned rule on children, and explain why the 
planned regulation is preferable to other potentially effective and 
reasonably feasible alternatives considered by the Agency. Today's 
final rule is not subject to the Executive Order because it is not 
economically significant as defined under point one of the Order, and 
because the Agency does not have reason to believe the environmental 
health or safety risks addressed by this action present a 
disproportionate risk to children.

VIII. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use

    This rule is not subject to Executive Order 13211, ``Actions 
Concerning Regulations That Significantly Affect Energy Supply, 
Distribution, or Use'' (66 Fed. Reg. 28355 (May 22, 2001)). This rule, 
as finalized, will not seriously disrupt energy supply, distribution 
patterns, prices, imports or exports. Furthermore, this rule is not an 
economically significant action under Executive Order 12866.

[[Page 59539]]

IX. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (``NTTAA''), Public Law 104-113, 12(d) (15 U.S.C. 272 note) 
directs EPA to use voluntary consensus standards in its regulatory 
activities unless to do so would be inconsistent with applicable law or 
otherwise impractical. Voluntary consensus standards are technical 
standards (e.g., materials specifications, test methods, sampling 
procedures, and business practices) that are developed or adopted by 
voluntary consensus standards bodies. The NTTAA directs EPA to provide 
Congress, through OMB, explanations when the Agency decides not to use 
available and applicable voluntary consensus standards.
    This rulemaking involves environmental monitoring or measurement. 
Both Performance Based Measurement System (PBMS) and specific 
measurement methods are finalized under this rule. The PBMS approach is 
intended to be more flexible and cost-effective for the regulated 
community; it is also intended to encourage innovation in analytical 
technology and improved data quality. Where allowed, EPA is not 
precluding the use of any method, whether it constitutes a voluntary 
consensus standard or not, as long as it meets the performance criteria 
specified.

X. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    Executive Order 12898, ``Federal Actions to Address Environmental 
Justice in Minority Populations and Low-Income Populations' (February 
11, 1994) requires us to complete an analysis of today's rule with 
regard to equity considerations. The Order is designed to address the 
environmental and human health conditions of minority and low-income 
populations. This section briefly discusses potential impacts (direct 
or disproportional) today's rule may have in the area of environmental 
justice.
    We have recently analyzed demographic data from the U.S. Census, 
and have previously examined data from two other reports: ``Race, 
Ethnicity, and Poverty Status of the Populations Living Near Cement 
Plants in the United States'' (EPA, August 1994) and ``Race, Ethnicity, 
and Poverty Status of the Populations Living Near Hazardous Waste 
Incinerators in the United States'' (EPA, October 1994). These reports 
examine the number of low-income and minority individuals living near a 
relatively large sample of cement kilns and hazardous waste 
incinerators and provide county, state, and national population 
percentages for various sub-populations. The demographic data in these 
reports provide several important findings when examined in conjunction 
with the risk reductions projected from today's rule.
    We find that combustion facilities, in general, are not located in 
areas with disproportionately high minority and low-income populations. 
However, there is evidence that hazardous waste burning cement kilns 
are somewhat more likely to be located in areas that have relatively 
higher low-income populations. Furthermore, there are a small number of 
commercial hazardous waste incinerators located in highly urbanized 
areas where there is a disproportionately high concentration of 
minorities and low-income populations within one and five mile radii. 
The reduced emissions at these facilities due to today's rule could 
represent meaningful environmental and health improvements for these 
populations. Overall, today's rule should not result in any adverse or 
disproportional health or safety effects on minority or low-income 
populations. Any impacts on these populations are likely to be positive 
due to the reduction in emissions from combustion facilities near 
minority and low-income population groups. The Assessment document 
available in the RCRA docket established for today's rule discusses our 
Environmental Justice analysis.

XI. Congressional Review

    The Congressional Review Act (CRA), 5 U.S.C. 801 et seq., as added 
by the Small Business Regulatory Enforcement Fairness Act of 1996, 
generally provides that before a rule may take effect, the agency 
promulgating the rule must submit a rule report, which includes a copy 
of the rule, to each House of the Congress and to the Comptroller 
General of the United States. Prior to publication of the final rule in 
the Federal Register, we will submit all necessary information to the 
U.S. Senate, the U.S. House of Representatives, and the Comptroller 
General of the United States. Under the CRA, a major rule cannot take 
effect until 60 days after it is published in the Federal Register. 
This action is not a ``major rule'' as defined by 5 U.S.C. 804(2).

List of Subjects

40 CFR Part 9

    Environmental protection, Reporting and recordkeeping requirements.

40 CFR Part 63

    Environmental protection, Air pollution control, Hazardous 
substances, Incorporation by reference, Reporting and recordkeeping 
requirements.

40 CFR Part 260

    Environmental protection, Administrative practice and procedure, 
Confidential business information, Hazardous waste, Reporting and 
recordkeeping requirements.

40 CFR Part 264

    Environmental protection, Air pollution control, Hazardous waste, 
Insurance, Packaging and containers, Reporting and recordkeeping 
requirements, Security measures, Surety bonds.

40 CFR Part 265

    Environmental protection, Air pollution control, Hazardous waste, 
Insurance, Packaging and containers, Reporting and recordkeeping 
requirements.

40 CFR Part 266

    Environmental protection, Energy, Hazardous waste, Recycling, 
Reporting and recordkeeping requirements.

40 CFR Part 270

    Environmental protection, Administrative practice and procedure, 
Confidential business information, Hazardous materials transportation, 
Hazardous waste, Reporting and recordkeeping requirements.

40 CFR Part 271

    Administrative practice and procedure, Hazardous materials 
transportation, Hazardous waste, Intergovernmental relations, Reporting 
and recordkeeping requirements.

    Dated: September 14, 2005.
Stephen L. Johnson,
Administrator.

0
For the reasons set out in the preamble, title 40, chapter I, of the 
Code of Federal Regulations is amended as follows:

PART 9--OMB APPROVALS UNDER THE PAPERWORK REDUCTION ACT

0
1. The authority citation for part 9 continues to read as follows:

    Authority: 7 U.S.C. 135 et seq., 136-136y; 15 U.S.C. 2001, 2003, 
2005, 2006, 2601-2671; 21 U.S.C. 331j, 346a, 348; 31 U.S.C. 9701; 33 
U.S.C. 1251 et seq., 1311, 1313d, 1314, 1318, 1321, 1326, 1330, 
1342, 1344, 1345 (d) and (e), 1361; E.O. 11735, 38 FR 21243, 3 CFR, 
1971-1975 Comp. p. 973; 42 U.S.C. 241, 242b, 243, 246, 300f, 300g, 
300g-1, 300g-2,

[[Page 59540]]

300g-3, 300g-4, 300g-5, 300g-6, 300j-1, 300j-2, 300j-3, 300j-4, 
300j-9, 1857 et seq., 6901-6992k, 7401-7671q, 7542, 9601-9657, 
11023, 11048.

0
2. Section 9.1 is amended in the table under center heading ``National 
Emission Standards for Hazardous Air Pollutants for Source Categories'' 
by adding entry ``63.1200-63.1221'' in numerical order to read as 
follows:


Sec.  9.1  OMB approvals under the Paperwork Reduction Act.

* * * * *

------------------------------------------------------------------------
          40 CFR citation                      OMB control No.
------------------------------------------------------------------------
 
                              * * * * * * *
------------------------------------
   National Emission Standards for Hazardous Air Pollutants for Source
                             Categories \3\
------------------------------------------------------------------------
 
                              * * * * * * *
63.1200-63.1221....................  2050-0171
 
------------------------------------------------------------------------
 \3\ The ICRs referenced in this section of the table encompass the
  applicable general provisions contained in 40 CFR part 63, subpart A,
  which are not independent information collection requirements.

* * * * *

PART 63--NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS 
FOR SOURCE CATEGORIES

0
1. The authority citation for part 63 continues to read as follows:

    Authority: 42 U.S.C. 7401 et seq.

0
2. Section 63.14 is amended by:
0
a. Removing paragraphs (i)(1) and (i)(2).
0
b. Redesignating paragraph (i)(3) as (i)(1).
0
c. Adding and reserving new paragraph (i)(2).
0
d. Revising paragraph (k).
    The revisions and additions read as follows:


Sec.  63.14  Incorporations by reference.

* * * * *
    (i) * * *
    (2) [Reserved]
* * * * *
    (k) The following materials are available for purchase from the 
National Technical Information Service (NTIS), 5285 Port Royal Road, 
Springfield, VA 22161, (703) 605-6000 or (800) 553-6847; or for 
purchase from the Superintendent of Documents, U.S. Government Printing 
Office, Washington, DC 20402, (202) 512-1800:
    (1) The following methods as published in the test methods 
compendium known as ``Test Methods for Evaluating Solid Waste, 
Physical/Chemical Methods,'' EPA Publication SW-846, Third Edition. A 
suffix of ``A'' in the method number indicates revision one (the method 
has been revised once). A suffix of ``B'' in the method number 
indicates revision two (the method has been revised twice).
    (i) Method 0023A, ``Sampling Method for Polychlorinated Dibenzo-p-
Dioxins and Polychlorinated Dibenzofuran Emissions from Stationary 
Sources,'' dated December 1996 and in Update III, IBR approved for 
Sec.  63.1208(b)(1) of Subpart EEE of this part.
    (ii) Method 9071B, ``n-Hexane Extractable Material (HEM) for 
Sludge, Sediment, and Solid Samples,'' dated April 1998 and in Update 
IIIA, IBR approved for Sec.  63.7824(e) of Subpart FFFFF of this part.
    (iii) Method 9095A, ``Paint Filter Liquids Test,'' dated December 
1996 and in Update III, IBR approved for Sec. Sec.  63.7700(b) and 
63.7765 of Subpart EEEEE of this part.
    (2) [Reserved]

0
3. Section 63.1200 is amended by:
0
a. Revising the introductory text.
0
b. Revising paragraph (a)(2).
0
c. Adding entry (4) in Table 1 in paragraph (b).
    The revisions and additions read as follows:


Sec.  63.1200  Who is subject to these regulations?

    The provisions of this subpart apply to all hazardous waste 
combustors: hazardous waste incinerators, hazardous waste cement kilns, 
hazardous waste lightweight aggregate kilns, hazardous waste solid fuel 
boilers, hazardous waste liquid fuel boilers, and hazardous waste 
hydrochloric acid production furnaces. Hazardous waste combustors are 
also subject to applicable requirements under parts 260 through 270 of 
this chapter.
    (a) * * *
    (2) Both area sources and major sources subject to this subpart, 
but not previously subject to title V, are immediately subject to the 
requirement to apply for and obtain a title V permit in all States, and 
in areas covered by part 71 of this chapter.
    (b) * * *

   Table 1 to Sec.   63.1200.--Hazardous Waste Combustors Exempt From
                               Subpart EEE
------------------------------------------------------------------------
              If                      And If                Then
------------------------------------------------------------------------
 
                              * * * * * * *
(4) You meet the definition of  .................  You are not subject
 a small quantity burner under                      to the requirements
 Sec.   266.108 of this                             of this subpart
 chapter                                            (Subpart EEE).
------------------------------------------------------------------------

* * * * *

0
4. Section 63.1201 is amended in paragraph (a) by revising the 
definitions of ``Hazardous waste combustor'', ``New source'', and 
``TEQ'', and adding definitions for ``Btu'', ``Hazardous waste 
hydrochloric acid production furnace'', ``Hazardous waste liquid fuel 
boiler'', ``Hazardous waste solid fuel boiler'', and ``System removal 
efficiency'' in alphabetical order to read as follows:

[[Page 59541]]

Sec.  63.1201  Definitions and acronyms used in this subpart.

    (a) * * *
    Btu means British Thermal Units.
* * * * *
    Hazardous waste combustor means a hazardous waste incinerator, 
hazardous waste burning cement kiln, hazardous waste burning 
lightweight aggregate kiln, hazardous waste liquid fuel boiler, 
hazardous waste solid fuel boiler, or hazardous waste hydrochloric acid 
production furnace.
* * * * *
    Hazardous waste hydrochloric acid production furnace and Hazardous 
Waste HCl production furnace mean a halogen acid furnace defined under 
Sec.  260.10 of this chapter that produces aqueous hydrochloric acid 
(HCl) product and that burns hazardous waste at any time.
* * * * *
    Hazardous waste liquid fuel boiler means a boiler defined under 
Sec.  260.10 of this chapter that does not burn solid fuels and that 
burns hazardous waste at any time. Liquid fuel boiler includes boilers 
that only burn gaseous fuel.
* * * * *
    Hazardous waste solid fuel boiler means a boiler defined under 
Sec.  260.10 of this chapter that burns a solid fuel and that burns 
hazardous waste at any time.
* * * * *
    New source means any affected source the construction or 
reconstruction of which is commenced after the dates specified under 
Sec. Sec.  63.1206(a)(1)(i)(B), (a)(1)(ii)(B), and (a)(2)(ii).
* * * * *
    System removal efficiency means [1 - Emission Rate (mass/time) / 
Feedrate (mass/time)] X 100.
* * * * *
    TEQ means the international method of expressing toxicity 
equivalents for dioxins and furans as defined in U.S. EPA, Interim 
Procedures for Estimating Risks Associated with Exposures to Mixtures 
of Chlorinated Dibenzo-p-dioxins and -dibenzofurans (CDDs and CDFs) and 
1989 Update, March 1989.
* * * * *

0
5. Section 63.1203 is amended by:
0
a. Revising an undesignated center heading above the section heading.
0
b. Revising the section heading.
0
c. Revising paragraph (c)(3)(2).
    The revisions and additions read as follows:

Interim Emissions Standards and Operating Limits For Incinerators, 
Cement Kilns, and Lightweight Aggregate Kilns


Sec.  63.1203  What are the standards for hazardous waste incinerators 
that are effective until compliance with the standards under Sec.  
63.1219?

* * * * *
    (c) * * *
    (3) * * *
    (ii) You must specify one or more POHCs that are representative of 
the most difficult to destroy organic compounds in your hazardous waste 
feedstream. You must base this specification on the degree of 
difficulty of incineration of the organic constituents in the hazardous 
waste and on their concentration or mass in the hazardous waste feed, 
considering the results of hazardous waste analyses or other data and 
information.
* * * * *

0
6. The section heading to Sec.  63.1204 and paragraph (c)(3)(ii) are 
revised to read as follows:


Sec.  63.1204  What are the standards for hazardous waste burning 
cement kilns that are effective until compliance with the standards 
under Sec.  63.1220?

* * * * *
    (c) * * *
    (3) * * *
    (ii) You must specify one or more POHCs that are representative of 
the most difficult to destroy organic compounds in your hazardous waste 
feedstream. You must base this specification on the degree of 
difficulty of incineration of the organic constituents in the hazardous 
waste and on their concentration or mass in the hazardous waste feed, 
considering the results of hazardous waste analyses or other data and 
information.
* * * * *

0
7. The section heading to Sec.  63.1205 and paragraph (c)(3)(ii) are 
revised to read as follows:


Sec.  63.1205  What are the standards for hazardous waste burning 
lightweight aggregate kilns that are effective until compliance with 
the standards under Sec.  63.1221?

* * * * *
    (c) * * *
    (3) * * *
    (ii) You must specify one or more POHCs that are representative of 
the most difficult to destroy organic compounds in your hazardous waste 
feedstream. You must base this specification on the degree of 
difficulty of incineration of the organic constituents in the hazardous 
waste and on their concentration or mass in the hazardous waste feed, 
considering the results of hazardous waste analyses or other data and 
information.
* * * * *

0
8. Section 63.1206 is amended by:
0
a. Revising paragraph (a).
0
b. Revising paragraphs (b)(1)(ii), (b)(6) introductory text, 
(b)(7)(i)(A), (b)(7)(ii), (b)(9)(i) introductory text, (b)(9)(i)(A), 
(b)(9)(iv)(A), (b)(9)(vi), (b)(9)(vii) introductory text, 
(b)(9)(viii)(D), (b)(9)(ix)(D), (b)(10)(i) introductory text, 
(b)(10)(i)(A), (b)(10)(vi), (b)(10)(vii) introductory text, 
(b)(10)(viii)(D), (b)(10)(ix)(D), (b)(11), (b)(13)(i) introductory 
text, (b)(13)(ii), and (b)(14).
0
c. Adding paragraph (b)(16).
0
d. Revising paragraphs (c)(1)(i) introductory text, (c)(3)(iv), 
(c)(6)(iii)(B) introductory text, (c)(6)(iv) introductory text, and 
(c)(7).
0
e. Adding paragraphs (c)(8) and (c)(9).
    The revisions and additions read as follows:


Sec.  63.1206  When and how must you comply with the standards and 
operating requirements?

    (a) Compliance dates. (1) Compliance dates for incinerators, cement 
kilns, and lightweight aggregate kilns that burn hazardous waste. (i) 
Compliance date for standards under Sec. Sec.  63.1203, 63.1204, and 
63.1205. (A) Compliance dates for existing sources. You must comply 
with the emission standards under Sec. Sec.  63.1203, 63.1204, and 
63.1205 and the other requirements of this subpart no later than the 
compliance date, September 30, 2003, unless the Administrator grants 
you an extension of time under Sec.  63.6(i) or Sec.  63.1213.
    (B) New or reconstructed sources. (1) If you commenced construction 
or reconstruction of your hazardous waste combustor after April 19, 
1996, you must comply with the emission standards under Sec. Sec.  
63.1203, 63.1204, and 63.1205 and the other requirements of this 
subpart by the later of September 30, 1999 or the date the source 
starts operations, except as provided by paragraph (a)(1)(i)(B)(2) of 
this section. The costs of retrofitting and replacement of equipment 
that is installed specifically to comply with this subpart, between 
April 19, 1996 and a source's compliance date, are not considered to be 
reconstruction costs.
    (2) For a standard under Sec. Sec.  63.1203, 63.1204, and 63.1205 
that is more stringent than the standard proposed on April 19, 1996, 
you may achieve compliance no later than September 30, 2003 if you 
comply with the standard proposed on April 19, 1996 after September 30, 
1999. This exception does not apply, however, to new or

[[Page 59542]]

reconstructed area source hazardous waste combustors that become major 
sources after September 30, 1999. As provided by Sec.  63.6(b)(7), such 
sources must comply with the standards under Sec. Sec.  63.1203, 
63.1204, and 63.1205 at startup.
    (ii) Compliance date for standards under Sec. Sec.  63.1219, 
63.1220, and 63.1221. (A) Compliance dates for existing sources. You 
must comply with the emission standards under Sec. Sec.  63.1219, 
63.1220, and 63.1221 and the other requirements of this subpart no 
later than the compliance date, October 14, 2008, unless the 
Administrator grants you an extension of time under Sec.  63.6(i) or 
Sec.  63.1213.
    (B) New or reconstructed sources. (1) If you commenced construction 
or reconstruction of your hazardous waste combustor after April 20, 
2004, you must comply with the new source emission standards under 
Sec. Sec.  63.1219, 63.1220, and 63.1221 and the other requirements of 
this subpart by the later of October 12, 2005 or the date the source 
starts operations, except as provided by paragraph (a)(1)(ii)(B)(2) of 
this section. The costs of retrofitting and replacement of equipment 
that is installed specifically to comply with this subpart, between 
April 20, 2004, and a source's compliance date, are not considered to 
be reconstruction costs.
    (2) For a standard under Sec. Sec.  63.1219, 63.1220, and 63.1221 
that is more stringent than the standard proposed on April 20, 2004, 
you may achieve compliance no later than October 14, 2008, if you 
comply with the standard proposed on April 20, 2004, after October 12, 
2005. This exception does not apply, however, to new or reconstructed 
area source hazardous waste combustors that become major sources after 
October 14, 2008. As provided by Sec.  63.6(b)(7), such sources must 
comply with the standards under Sec. Sec.  63.1219, 63.1220, and 
63.1221 at startup.
    (2) Compliance dates for solid fuel boilers, liquid fuel boilers, 
and hydrogen chloride production furnaces that burn hazardous waste for 
standards under Sec. Sec.  63.1216, 63.1217, and 63.1218. (i) 
Compliance date for existing sources. You must comply with the 
standards of this subpart no later than the compliance date, October 
14, 2008, unless the Administrator grants you an extension of time 
under Sec.  63.6(i) or Sec.  63.1213.
    (ii) New or reconstructed sources. (A) If you commenced 
construction or reconstruction of your hazardous waste combustor after 
October 12, 2005, you must comply with the new source emission 
standards of this subpart by the later of October 12, 2005, or the date 
the source starts operations, except as provided by paragraph 
(a)(2)(ii)(B) of this section. The costs of retrofitting and 
replacement of equipment that is installed specifically to comply with 
this subpart, between April 20, 2004, and a source's compliance date, 
are not considered to be reconstruction costs.
    (B) For a standard in the subpart that is more stringent than the 
standard proposed on April 20, 2004, you may achieve compliance no 
later than October 14, 2008, if you comply with the standard proposed 
on April 20, 2004, after October 12, 2005. This exception does not 
apply, however, to new or reconstructed area source hazardous waste 
combustors that become major sources after October 14, 2008. As 
provided by Sec.  63.6(b)(7), such sources must comply with this 
subpart at startup.
    (3) Early compliance. If you choose to comply with the emission 
standards of this subpart prior to the dates specified in paragraphs 
(a)(1) and (a)(2) of this section, your compliance date is the earlier 
of the date you postmark the Notification of Compliance under Sec.  
63.1207(j)(1) or the dates specified in paragraphs (a)(1) and (a)(2) of 
this section.
    (b) * * *
    (1) * * *
    (ii) When hazardous waste is not in the combustion chamber (i.e., 
the hazardous waste feed to the combustor has been cut off for a period 
of time not less than the hazardous waste residence time) and you have 
documented in the operating record that you are complying with all 
otherwise applicable requirements and standards promulgated under 
authority of sections 112 (e.g., 40 CFR part 63, subparts LLL, DDDDD, 
and NNNNN) or 129 of the Clean Air Act in lieu of the emission 
standards under Sec. Sec.  63.1203, 63.1204, 63.1205, 63.1215, 63.1216, 
63.1217, 63.1218, 63.1219, 63.1220, and 63.1221; the monitoring and 
compliance standards of this section and Sec. Sec.  63.1207 through 
63.1209, except the modes of operation requirements of Sec.  
63.1209(q); and the notification, reporting, and recordkeeping 
requirements of Sec. Sec.  63.1210 through 63.1212.
* * * * *
    (6) Compliance with the carbon monoxide and hydrocarbon emission 
standards. This paragraph applies to sources that elect to comply with 
the carbon monoxide and hydrocarbon emissions standards of this subpart 
by documenting continuous compliance with the carbon monoxide standard 
using a continuous emissions monitoring system and documenting 
compliance with the hydrocarbon standard during the destruction and 
removal efficiency (DRE) performance test or its equivalent.
* * * * *
    (7) * * * (i) * * *
    (A) You must document compliance with the Destruction and Removal 
Efficiency (DRE) standard under this subpart only once provided that 
you do not modify the source after the DRE test in a manner that could 
affect the ability of the source to achieve the DRE standard.
* * * * *
    (ii) Sources that feed hazardous waste at locations other than the 
normal flame zone. (A) Except as provided by paragraph (b)(7)(ii)(B) of 
this section, if you feed hazardous waste at a location in the 
combustion system other than the normal flame zone, then you must 
demonstrate compliance with the DRE standard during each comprehensive 
performance test;
    (B)(1) A cement kiln that feeds hazardous waste at a location other 
than the normal flame zone need only demonstrate compliance with the 
DRE standard during three consecutive comprehensive performance tests 
provided that:
    (i) All three tests achieve the DRE standard in this subpart; and
    (ii) The design, operation, and maintenance features of each of the 
three tests are similar;
    (iii) The data in lieu restriction of Sec.  63.1207(c)(2)(iv) does 
not apply when complying with the provisions of paragraph (b)(7)(ii)(B) 
of this section;
    (2) If at any time you change your design, operation, and 
maintenance features in a manner that could reasonably be expected to 
affect your ability to meet the DRE standard, then you must comply with 
the requirements of paragraph (b)(7)(ii)(A) of this section.
* * * * *
    (9) * * * (i) You may petition the Administrator to request 
alternative standards to the mercury or hydrogen chloride/chlorine gas 
emission standards of this subpart, to the semivolatile metals emission 
standards under Sec. Sec.  63.1205, 63.1221(a)(3)(ii), or 
63.1221(b)(3)(ii), or to the low volatile metals emissions standards 
under Sec. Sec.  63.1205, 63.1221(a)(4)(ii), or 63.1221(b)(4)(ii) if:
    (A) You cannot achieve one or more of these standards while using 
maximum achievable control technology (MACT) because of raw material 
contributions to emissions of mercury, semivolatile metals, low

[[Page 59543]]

volatile metals, or hydrogen chloride/chlorine gas; or
* * * * *
    (iv) * * * (A) The alternative standard petition you submit under 
paragraph (b)(9)(i)(A) of this section must include data or information 
documenting that raw material contributions to emissions prevent you 
from complying with the emission standard even though the source is 
using MACT, as defined under paragraphs (b)(9)(viii) and (ix) of this 
section, for the standard for which you are seeking relief.
* * * * *
    (vi) You must include data or information with semivolatile metals, 
low volatile metals, and hydrogen chloride/chlorine gas alternative 
standard petitions that you submit under paragraph (b)(9)(i)(A) of this 
section documenting that semivolatile metals, low volatile metals, and 
hydrogen chloride/chlorine gas emissions attributable to the hazardous 
waste only will not exceed the emission standards of this subpart.
    (vii) You must not operate pursuant to your recommended alternative 
standards in lieu of emission standards specified in this subpart:
* * * * *
    (viii) * * *
    (D) For hydrogen chloride/chlorine gas, a hazardous waste chlorine 
feedrate corresponding to an MTEC of 2,000,000 [mu]g/dscm or less, and 
use of an air pollution control device with a hydrogen chloride/
chlorine gas removal efficiency of 85 percent or greater.
    (ix) * * *
    (D) For hydrogen chloride/chlorine gas, a hazardous waste chlorine 
feedrate corresponding to an MTEC of 14,000,000 [mu]g/dscm or less, and 
use of an air pollution control device with a hydrogen chloride/
chlorine gas removal efficiency of 99.6 percent or greater.
    (10) * * * (i) You may petition the Administrator to request 
alternative standards to the mercury or hydrogen chloride/chlorine gas 
emission standards of this subpart, to the semivolatile metals emission 
standards under Sec. Sec.  63.1204, 63.1220(a)(3)(ii), or 
63.1220(b)(3)(ii), or to the low volatile metals emissions standards 
under Sec. Sec.  63.1204, 63.1220(a)(4)(ii), or 63.1220(b)(4)(ii) if:
    (A) You cannot achieve one or more of these standards while using 
maximum achievable control technology (MACT) because of raw material 
contributions to emissions of mercury, semivolatile metals, low 
volatile metals, or hydrogen chloride/chlorine gas; or
* * * * *
    (vi) You must include data or information with semivolatile metals, 
low volatile metals, and hydrogen chloride/chlorine gas alternative 
standard petitions that you submit under paragraph (b)(10)(i)(A) of 
this section documenting that emissions of the regulated metals and 
hydrogen chloride/chlorine gas attributable to the hazardous waste only 
will not exceed the emission standards in this subpart.
    (vii) You must not operate pursuant to your recommended alternative 
standards in lieu of emission standards specified in this subpart:
* * * * *
    (viii) * * *
    (D) For hydrogen chloride/chlorine gas, a hazardous waste chlorine 
feedrate corresponding to an MTEC of 720,000 [mu]g/dscm or less.
    (ix) * * *
    (D) For hydrogen chloride/chlorine gas, a hazardous waste chlorine 
feedrate corresponding to an MTEC of 420,000 [mu]g/dscm or less.
    (11) Calculation of hazardous waste residence time. You must 
calculate the hazardous waste residence time and include the 
calculation in the performance test plan under Sec.  63.1207(f) and the 
operating record. You must also provide the hazardous waste residence 
time in the Documentation of Compliance under Sec.  63.1211(c) and the 
Notification of Compliance under Sec. Sec.  63.1207(j) and 63.1210(d).
* * * * *
    (13) * * *
    (i) Cement kilns that feed hazardous waste at a location other than 
the end where products are normally discharged and where fuels are 
normally fired must comply with the carbon monoxide and hydrocarbon 
standards of this subpart as follows:
* * * * *
    (ii) Lightweight aggregate kilns that feed hazardous waste at a 
location other than the end where products are normally discharged and 
where fuels are normally fired must comply with the hydrocarbon 
standards of this subpart as follows:
    (A) Existing sources must comply with the 20 parts per million by 
volume hydrocarbon standard of this subpart;
    (B) New sources must comply with the 20 parts per million by volume 
hydrocarbon standard of this subpart.
    (14) Alternative to the particulate matter standard for 
incinerators. (i). General. In lieu of complying with the particulate 
matter standards under Sec.  63.1203, you may elect to comply with the 
following alternative metal emission control requirements:
    (ii) Alternative metal emission control requirements for existing 
incinerators. (A) You must not discharge or cause combustion gases to 
be emitted into the atmosphere that contain cadmium, lead, and selenium 
in excess of 240 [mu]g/dscm, combined emissions, corrected to 7 percent 
oxygen; and,
    (B) You must not discharge or cause combustion gases to be emitted 
into the atmosphere that contain antimony, arsenic, beryllium, 
chromium, cobalt, manganese, and nickel in excess of 97 [mu]g/dscm, 
combined emissions, corrected to 7 percent oxygen.
    (iii) Alternative metal emission control requirements for new 
incinerators. (A) You must not discharge or cause combustion gases to 
be emitted into the atmosphere that contain cadmium, lead, and selenium 
in excess of 24 [mu]g/dscm, combined emissions, corrected to 7 percent 
oxygen; and,
    (B) You must not discharge or cause combustion gases to be emitted 
into the atmosphere that contain antimony, arsenic, beryllium, 
chromium, cobalt, manganese, and nickel in excess of 97 [mu]g/dscm, 
combined emissions, corrected to 7 percent oxygen.
    (iv) Operating limits. Semivolatile and low volatile metal 
operating parameter limits must be established to ensure compliance 
with the alternative emission limitations described in paragraphs 
(e)(2) and (e)(3) of this section pursuant to Sec.  63.1209(n), except 
that semivolatile metal feedrate limits apply to lead, cadmium, and 
selenium, combined, and low volatile metal feedrate limits apply to 
arsenic, beryllium, chromium, antimony, cobalt, manganese, and nickel, 
combined.
* * * * *
    (16) Compliance with subcategory standards for liquid fuel boilers. 
You must comply with the mercury, semivolatile, low volatile metal, and 
total chlorine standards for liquid fuel boilers under Sec.  63.1217 as 
follows:
    (i) You must determine the as-fired heating value of each batch of 
hazardous waste fired by each firing system of the boiler so that you 
know the mass-weighted heating value of the hazardous waste fired at 
all times.
    (ii) If the as-fired heating value of the hazardous waste is 10,000 
Btu per pound or greater, you are subject to the thermal emission 
concentration standards (lb/million Btu) under Sec.  63.1217.
    (iii) If the as-fired heating value of the hazardous waste is less 
than 10,000 Btu/lb, you are subject to the mass or volume emission 
concentration

[[Page 59544]]

standards ([mu]g/dscm or ppmv) under Sec.  63.1217.
    (iv) If the as-fired heating value of hazardous wastes varies above 
and below 10,000 Btu/lb over time, you are subject to the thermal 
concentration standards when the heating value is 10,000 Btu/lb or 
greater and the mass concentration standards when the heating value is 
less than 10,000 Btu/lb. You may elect to comply at all times with the 
more stringent operating requirements that ensure compliance with both 
the thermal emission concentration standards and the mass or volume 
emission concentration standards.
* * * * *
    (c) * * * (1) * * * (i) You must operate only under the operating 
requirements specified in the Documentation of Compliance under Sec.  
63.1211(c) or the Notification of Compliance under Sec. Sec.  
63.1207(j) and 63.1210(d), except:
* * * * *
    (3) * * *
    (iv) Failure of the AWFCO system. If the AWFCO system fails to 
automatically and immediately cutoff the flow of hazardous waste upon 
exceedance of a parameter required to be interlocked with the AWFCO 
system under paragraph (c)(3)(i) of this section, you have failed to 
comply with the AWFCO requirements of paragraph (c)(3) of this section. 
If an equipment or other failure prevents immediate and automatic 
cutoff of the hazardous waste feed, however, you must cease feeding 
hazardous waste as quickly as possible.
* * * * *
    (6) * * *
    (iii) * * *
    (B) Be trained under the requirements of, and certified under, one 
of the following American Society of Mechanical Engineers (ASME) 
standards: QHO-1-1994, QHO-1a-1996, or QHO-1-2004 (Standard for the 
Qualification and Certification of Hazardous Waste Incinerator 
Operators). If you elect to use the ASME program:
* * * * *
    (iv) Control room operators of cement kilns, lightweight aggregate 
kilns, solid fuel boilers, liquid fuel boilers, and hydrochloric acid 
production furnaces must be trained and certified under:
* * * * *
    (7) Operation and maintenance plan--(i) You must prepare and at all 
times operate according to an operation and maintenance plan that 
describes in detail procedures for operation, inspection, maintenance, 
and corrective measures for all components of the combustor, including 
associated pollution control equipment, that could affect emissions of 
regulated hazardous air pollutants.
    (ii) The plan must prescribe how you will operate and maintain the 
combustor in a manner consistent with good air pollution control 
practices for minimizing emissions at least to the levels achieved 
during the comprehensive performance test.
    (iii) This plan ensures compliance with the operation and 
maintenance requirements of Sec.  63.6(e) and minimizes emissions of 
pollutants, automatic waste feed cutoffs, and malfunctions.
    (iv) You must record the plan in the operating record.
    (8) Bag leak detection system requirements. (i) If your combustor 
is equipped with a baghouse (fabric filter), you must continuously 
operate either:
    (A) A bag leak detection system that meets the specifications and 
requirements of paragraph (c)(8)(ii) of this section and you must 
comply with the corrective measures and notification requirements of 
paragraphs (c)(8)(iii) and (iv) of this section; or
    (B) A particulate matter detection system under paragraph (c)(9) of 
this section.
    (ii) Bag leak detection system specification and requirements. (A) 
The bag leak detection system must be certified by the manufacturer to 
be capable of continuously detecting and recording particulate matter 
emissions at concentrations of 1.0 milligrams per actual cubic meter 
unless you demonstrate, under Sec.  63.1209(g)(1), that a higher 
detection limit would routinely detect particulate matter loadings 
during normal operations;
    (B) The bag leak detection system shall provide output of relative 
or absolute particulate matter loadings;
    (C) The bag leak detection system shall be equipped with an alarm 
system that will sound an audible alarm when an increase in relative 
particulate loadings is detected over a preset level;
    (D) The bag leak detection system shall be installed and operated 
in a manner consistent with available written guidance from the U.S. 
Environmental Protection Agency or, in the absence of such written 
guidance, the manufacturer's written specifications and recommendations 
for installation, operation, and adjustment of the system;
    (E) The initial adjustment of the system shall, at a minimum, 
consist of establishing the baseline output by adjusting the 
sensitivity (range) and the averaging period of the device, and 
establishing the alarm set points and the alarm delay time;
    (F) Following initial adjustment, you must not adjust the 
sensitivity or range, averaging period, alarm set points, or alarm 
delay time, except as detailed in the operation and maintenance plan 
required under paragraph (c)(7) of this section. You must not increase 
the sensitivity by more than 100 percent or decrease the sensitivity by 
more than 50 percent over a 365 day period unless such adjustment 
follows a complete baghouse inspection which demonstrates the baghouse 
is in good operating condition;
    (G) For negative pressure or induced air baghouses, and positive 
pressure baghouses that are discharged to the atmosphere through a 
stack, the bag leak detector shall be installed downstream of the 
baghouse and upstream of any wet acid gas scrubber; and
    (H) Where multiple detectors are required, the system's 
instrumentation and alarm system may be shared among the detectors.
    (iii) Bag leak detection system corrective measures requirements. 
The operating and maintenance plan required by paragraph (c)(7) of this 
section must include a corrective measures plan that specifies the 
procedures you will follow in the case of a bag leak detection system 
alarm. The corrective measures plan must include, at a minimum, the 
procedures used to determine and record the time and cause of the alarm 
as well as the corrective measures taken to correct the control device 
malfunction or minimize emissions as specified below. Failure to 
initiate the corrective measures required by this paragraph is failure 
to ensure compliance with the emission standards in this subpart.
    (A) You must initiate the procedures used to determine the cause of 
the alarm within 30 minutes of the time the alarm first sounds; and
    (B) You must alleviate the cause of the alarm by taking the 
necessary corrective measure(s) which may include, but are not to be 
limited to, the following:
    (1) Inspecting the baghouse for air leaks, torn or broken filter 
elements, or any other malfunction that may cause an increase in 
emissions;
    (2) Sealing off defective bags or filter media;
    (3) Replacing defective bags or filter media, or otherwise 
repairing the control device;
    (4) Sealing off a defective baghouse compartment;
    (5) Cleaning the bag leak detection system probe, or otherwise 
repairing the bag leak detection system; or
    (6) Shutting down the combustor.
    (iv) Excessive exceedances notification. If you operate the

[[Page 59545]]

combustor when the detector response exceeds the alarm set-point more 
than 5 percent of the time during any 6-month block time period, you 
must submit a notification to the Administrator within 30 days of the 
end of the 6-month block time period that describes the causes of the 
exceedances and the revisions to the design, operation, or maintenance 
of the combustor or baghouse you are taking to minimize exceedances. To 
document compliance with this requirement:
    (A) You must keep records of the date, time, and duration of each 
alarm, the time corrective action was initiated and completed, and a 
brief description of the cause of the alarm and the corrective action 
taken;
    (B) You must record the percent of the operating time during each 
6-month period that the alarm sounds;
    (C) In calculating the operating time percentage, if inspection of 
the fabric filter demonstrates that no corrective action is required, 
no alarm time is counted; and
    (D) If corrective action is required, each alarm shall be counted 
as a minimum of 1 hour.
    (9) Particulate matter detection system requirements for 
electrostatic precipitators and ionizing wet scrubbers. If your 
combustor is equipped with an electrostatic precipitator or ionizing 
wet scrubber, and you elect not to establish under Sec.  
63.1209(m)(1)(iv) site-specific control device operating parameter 
limits that are linked to the automatic waste feed cutoff system under 
paragraph (c)(3) of this section, you must continuously operate a 
particulate matter detection system that meets the specifications and 
requirements of paragraph (c)(9)(i) through (iii) of this section and 
you must comply with the corrective measures and notification 
requirements of paragraphs (c)(9)(iv) through (v) of this section.
    (i) Particulate matter detection system requirements.--(A) The 
particulate matter detection system must be certified by the 
manufacturer to be capable of continuously detecting and recording 
particulate matter emissions at concentrations of 1.0 milligrams per 
actual cubic meter unless you demonstrate, under Sec.  63.1209(g)(1), 
that a higher detection limit would routinely detect particulate matter 
loadings during normal operations;
    (B) The particulate matter detector shall provide output of 
relative or absolute particulate matter loadings;
    (C) The particulate matter detection system shall be equipped with 
an alarm system that will sound an audible alarm when an increase in 
relative or absolute particulate loadings is detected over the set-
point
    (D) You must install, operate, and maintain the particulate matter 
detection system in a manner consistent with the provisions of 
paragraph (c)(9) of this section and available written guidance from 
the U.S. Environmental Protection Agency or, in the absence of such 
written guidance, the manufacturer's written specifications and 
recommendations for installation, operation, maintenance and quality 
assurance of the system;
    (E) You must include procedures for installation, operation, 
maintenance, and quality assurance of the particulate matter detection 
system in the site-specific continuous monitoring system test plan 
required under Sec.  63.8(e)(3) of this chapter.
    (F) Where multiple detectors are required to monitor multiple 
control devices, the system's instrumentation and alarm system may be 
shared among the detectors.
    (G) You must establish the alarm set-point as provided by either 
paragraph (c)(9)(ii) or paragraph (c)(9)(iii) of this section.
    (ii) Establishing the alarm set-point without extrapolation. (A) 
The alarm set-point is the average of the test run averages of the 
detector response achieved during the comprehensive performance test 
demonstrating compliance with the particulate matter emission standard.
    (B) During the comprehensive performance test, you may simulate 
emission concentrations at the upper end of the range of normal 
operations by means including feeding high levels of ash and detuning 
the emission control equipment.
    (C) You must comply with the alarm set-point on a 6-hour rolling 
average, updated each hour with a one-hour block average that is the 
average of the detector responses over each 15-minute block;
    (iii) Establishing the alarm set-point with extrapolation. You may 
extrapolate the average of the test run averages of the detector 
response achieved during the comprehensive performance test as provided 
by paragraph (c)(9)(iii)(A) of this section to establish an alarm level 
after you approximate the correlation of the detector response to 
particulate matter concentration as prescribed by paragraph 
(c)(9)(iii)(B) of this section. You must comply with the extrapolated 
alarm set-point on a 6-hour rolling average, updated each hour with a 
one-hour block average that is the average of the detector responses 
over each 15-minute block.
    (A) You may extrapolate the detector response up to a particulate 
matter concentration that is 50% of the particulate matter emission 
standard or 125% of the highest particulate matter concentration used 
to develop the correlation under paragraph (c)(9)(iii)(B) of this 
section, whichever is greater. The extrapolated emission concentration 
must not exceed the particulate matter emission standard.
    (B) To establish an approximate correlation of the detector 
response to particulate matter emission concentrations, you should use 
as guidance Performance Specification-11 for PM CEMS (40 CFR Part 60, 
Appendix B), except that you need only conduct 5 runs to establish the 
initial correlation under Section 8.6 of Performance Specification 11.
    (C) For quality assurance, you should use as guidance Procedure 2 
of Appendix F to Part 60 of this chapter and the detector 
manufacturer's recommended procedures for periodic quality assurance 
checks and tests, except that:
    (1) You must conduct annual Relative Response Audits as prescribed 
by Procedure 2 of Appendix F to Part 60 of this chapter (Section 
10.3(6));
    (2) You need only conduct Relative Response Audits on a 3-year 
interval after passing two sequential annual Relative Response Audits.
    (D) An exceedance of the particulate matter emission standard by a 
particulate matter detection system for which particulate emission 
concentrations have been approximately correlated with the detector 
response under paragraph (c)(9)(iii) of this section is not evidence 
that the standard has been exceeded. The approximate correlation is 
used for compliance assurance to determine when corrective measures 
must be taken rather than for compliance monitoring.
    (iv) Particulate matter detection system corrective measures 
requirements. The operating and maintenance plan required by paragraph 
(c)(7) of this section must include a corrective measures plan that 
specifies the procedures you will follow in the case of a particulate 
matter detection system alarm. The corrective measures plan must 
include, at a minimum, the procedures used to determine and record the 
time and cause of the alarm as well as the corrective measures taken to 
correct the control device malfunction or minimize emissions as 
specified below. Failure to initiate the corrective measures required 
by this paragraph is failure to ensure compliance with the emission 
standards in this subpart.

[[Page 59546]]

    (A) You must initiate the procedures used to determine the cause of 
the alarm within 30 minutes of the time the alarm first sounds; and
    (B) You must alleviate the cause of the alarm by taking the 
necessary corrective measure(s) which may include shutting down the 
combustor.
    (v) Excessive exceedances notification. If you operate the 
combustor when the detector response exceeds the alarm set-point more 
than 5 percent of the time during any 6-month block time period, you 
must submit a notification to the Administrator within 30 days of the 
end of the 6-month block time period that describes the causes of the 
exceedances and the revisions to the design, operation, or maintenance 
of the combustor or emission control device you are taking to minimize 
exceedances. To document compliance with this requirement:
    (A) You must keep records of the date, time, and duration of each 
alarm, the time corrective action was initiated and completed, and a 
brief description of the cause of the alarm and the corrective action 
taken;
    (B) You must record the percent of the operating time during each 
6-month period that the alarm sounds;
    (C) In calculating the operating time percentage, if inspection of 
the emission control device demonstrates that no corrective action is 
required, no alarm time is counted; and
    (D) If corrective action is required, each alarm shall be counted 
as a minimum of 1 hour.

0
9. Section 63.1207 is amended by:
0
a. Revising paragraph (b)(1).
0
b. Adding paragraph (b)(3).
0
c. Revising paragraphs (c)(1) and (c)(2)(iii).
0
d. Adding paragraph (c)(3).
0
e. Revising paragraph (d)(4)(i).
0
f. Revising paragraphs (e)(2) and (e)(3)(iv).
0
g. Revising paragraphs (f)(1)(ii)(D), (f)(1)(x) introductory text, 
(f)(1)(xiii), (f)(1)(xiv), (f)(1)(xvi), and (f)(1)(xxv).
0
h. Adding paragraph (f)(1)(xv).
0
i. Revising paragraph (h)(2)(i).
0
j. Revising paragraph (j)(3).
0
k. Revising paragraph (l)(1) introductory text.
0
l. Revising paragraph (m)(2) introductory text.
    The revisions and additions read as follows:


Sec.  63.1207  What are the performance testing requirements?

* * * * *
    (b) * * *
    (1) Comprehensive performance test. You must conduct comprehensive 
performance tests to demonstrate compliance with the emission standards 
provided by this subpart, establish limits for the operating parameters 
provided by Sec.  63.1209, and demonstrate compliance with the 
performance specifications for continuous monitoring systems.
* * * * *
    (3) One-Time Dioxin/Furan Test for Sources Not Subject to a 
Numerical Dioxin/Furan Standard. For solid fuel boilers and 
hydrochloric acid production furnaces, for lightweight aggregate kilns 
that are not subject to a numerical dioxin/furan emission standard 
under Sec.  63.1221, and liquid fuel boilers that are not subject to a 
numerical dioxin/furan emission standard under Sec.  63.1217, you must 
conduct a one-time emission test for dioxin/furan under feed and 
operating conditions that are most likely to reflect daily maximum 
operating variability, similar to a dioxin/furan comprehensive 
performance test.
    (i) You must conduct the dioxin/furan emissions test no later than 
the deadline for conducting the initial comprehensive performance test.
    (ii) You may use dioxin/furan emissions data from previous testing 
to meet this requirement, provided that:
    (A) The testing was conducted under feed and operating conditions 
that are most likely to reflect daily maximum operating variability, 
similar to a dioxin/furan compliance test;
    (B) You have not changed the design or operation of the source in a 
manner that could significantly affect stack gas dioxin/furan emission 
concentrations; and
    (C) The data meet quality assurance objectives that may be 
determined on a site-specific basis.
    (iii) You may use dioxin/furan emissions data from a source to 
represent emissions from another on-site source in lieu of testing 
(i.e., data in lieu of testing) if the design and operation, including 
hazardous waste feed and other feedstreams, of the sources are 
identical.
    (iv) You must include the results of the one-time dioxin/furan 
emissions test with the results of the initial comprehensive 
performance test in the Notification of Compliance.
    (v) You must repeat the dioxin/furan emissions test if you change 
the design or operation of the source in a manner that may increase 
dioxin/furan emissions.
    (c) * * * (1) Test date. Except as provided by paragraphs (c)(2) 
and (c)(3) of this section, you must commence the initial comprehensive 
performance test not later than six months after the compliance date.
    (2) * * * (iii) The data in lieu test age restriction provided in 
paragraph (c)(2)(i)(A) of this section does not apply for the duration 
of the interim standards (i.e., the standards published in the Federal 
Register on February 13, 2002, 67 FR 6792). See 40 CFR parts 63, 264, 
265, 266, 270, and 271 revised as of July 1, 2002. Paragraph 
(c)(2)(i)(A) of this section does not apply until EPA promulgates 
permanent replacement standards pursuant to the Settlement Agreement 
noticed in the Federal Register on November 16, 2001 (66 FR 57715).
* * * * *
    (3) For incinerators, cement kilns, and lightweight aggregate 
kilns, you must commence the initial comprehensive performance test to 
demonstrate compliance with the standards under Sec. Sec.  63.1219, 
63.1220, and 63.1221 not later than 12 months after the compliance 
date.
    (d) * * *
    (4) * * * (i) Waiver of periodic comprehensive performance tests. 
Except as provided in paragraph (c)(2) of this section, you must 
conduct only an initial comprehensive performance test under the 
interim standards (i.e., the standards published in the Federal 
Register on February 13, 2002); all subsequent comprehensive 
performance testing requirements are waived under the interim 
standards. The provisions in the introductory text to paragraph (d) and 
in paragraph (d)(1) of this section do not apply until EPA promulgates 
permanent replacement standards pursuant to the Settlement Agreement 
noticed in the Federal Register on November 16, 2001.
* * * * *
    (e) * * *
    (2) You must make your site-specific test plan and CMS performance 
evaluation test plan available to the public for review no later than 
60 calendar days before initiation of the test. You must issue a public 
notice to all persons on your facility/public mailing list (developed 
pursuant to 40 CFR 70.7(h), 71.11(d)(3)(i)(E) and 124.10(c)(1)(ix)) 
announcing the availability of the test plans and the location where 
the test plans are available for review. The test plans must be 
accessible to the public for 60 calendar days, beginning on the date 
that you issue your public notice. The location must be unrestricted 
and provide access to the public during reasonable hours and provide a 
means for the public to obtain copies. The notification must include 
the following information at a minimum:

[[Page 59547]]

    (i) The name and telephone number of the source's contact person;
    (ii) The name and telephone number of the regulatory agency's 
contact person;
    (iii) The location where the test plans and any necessary 
supporting documentation can be reviewed and copied;
    (iv) The time period for which the test plans will be available for 
public review; and
    (v) An expected time period for commencement and completion of the 
performance test and CMS performance evaluation test.
    (3) * * *
    (iv) Public notice. At the same time that you submit your petition 
to the Administrator, you must notify the public (e.g., distribute a 
notice to the facility/public mailing list developed pursuant to 40 CFR 
70.7(h), 71.11(d)(3)(i)(E) and 124.10(c)(1)(ix)) of your petition to 
waive a performance test. The notification must include all of the 
following information at a minimum:
    (A) The name and telephone number of the source's contact person;
    (B) The name and telephone number of the regulatory agency's 
contact person;
    (C) The date the source submitted its site-specific performance 
test plan and CMS performance evaluation test plans; and
    (D) The length of time requested for the waiver.
    (f) * * *
    (1) * * *
    (ii) * * *
    (D) The Administrator may approve on a case-by-case basis a 
hazardous waste feedstream analysis for organic hazardous air 
pollutants in lieu of the analysis required under paragraph 
(f)(1)(ii)(A) of this section if the reduced analysis is sufficient to 
ensure that the POHCs used to demonstrate compliance with the 
applicable DRE standards of this subpart continue to be representative 
of the most difficult to destroy organic compounds in your hazardous 
waste feedstreams;
* * * * *
    (x) If you are requesting to extrapolate metal feedrate limits from 
comprehensive performance test levels under Sec. Sec.  63.1209(l)(1)(v) 
or 63.1209(n)(2)(vii):
* * * * *
    (xiii) For cement kilns with in-line raw mills, if you elect to use 
the emissions averaging provision of this subpart, you must notify the 
Administrator of your intent in the initial (and subsequent) 
comprehensive performance test plan, and provide the information 
required by the emission averaging provision;
    (xiv) For preheater or preheater/precalciner cement kilns with dual 
stacks, if you elect to use the emissions averaging provision of this 
subpart, you must notify the Administrator of your intent in the 
initial (and subsequent) comprehensive performance test plan, and 
provide the information required by the emission averaging provision;
    (xv) If you request to use Method 23 for dioxin/furan you must 
provide the information required under Sec.  63.1208(b)(1)(i)(B);
    (xvi) If you are not required to conduct performance testing to 
document compliance with the mercury, semivolatile metals, low volatile 
metals, or hydrogen chloride/chlorine gas emission standards under 
paragraph (m) of this section, you must include with the comprehensive 
performance test plan documentation of compliance with the provisions 
of that section.
* * * * *
    (xxv) If your source is equipped with a dry scrubber to control 
hydrogen chloride and chlorine gas, you must document in the 
comprehensive performance test plan key parameters that affect 
adsorption, and the limits you establish for those parameters based on 
the sorbent used during the performance test, if you elect not to 
specify and use the brand and type of sorbent used during the 
comprehensive performance test, as required by Sec.  
63.1209(o)(4)(iii)(A); and
* * * * *
    (h) * * *
    (2) * * *
    (i) Operations when stack emissions testing for dioxin/furan, 
mercury, semivolatile metals, low volatile metals, particulate matter, 
or hydrogen chloride/chlorine gas is being performed; and
* * * * *
    (j) * * *
    (3) See Sec. Sec.  63.7(g), 63.9(h), and 63.1210(d) for additional 
requirements pertaining to the Notification of Compliance (e.g., you 
must include results of performance tests in the Notification of 
Compliance).
* * * * *
    (l) Failure of performance test--(1) Comprehensive performance 
test. The provisions of this paragraph do not apply to the initial 
comprehensive performance test if you conduct the test prior to your 
compliance date.
* * * * *
    (m) * * *
    (2) You are not required to conduct performance tests to document 
compliance with the mercury, semivolatile metals, low volatile metals, 
or hydrogen chloride/chlorine gas emission standards under the 
conditions specified in this paragraph (m)(2). You are deemed to be in 
compliance with an emission standard if the twelve-hour rolling average 
maximum theoretical emission concentration (MTEC) does not exceed the 
emission standard:
* * * * *

0
10. Section 63.1208 is amended by removing and reserving paragraph (a) 
and revising paragraphs (b)(1)(i) and (b)(5) to read as follows:


Sec.  63.1208  What are the test methods?

    (a) [Reserved]
    (b) * * *
    (1) * * * (i) To determine compliance with the emission standard 
for dioxins and furans, you must use:
    (A) Method 0023A, Sampling Method for Polychlorinated Dibenzo-p-
Dioxins and Polychlorinated Dibenzofurans emissions from Stationary 
Sources, EPA Publication SW-846 (incorporated by reference-- see Sec.  
63.14); or
    (B) Method 23, provided in appendix A, part 60 of this chapter, 
after approval by the Administrator.
    (1) You may request approval to use Method 23 in the performance 
test plan required under Sec.  63.1207(e)(i) and (ii).
    (2) In determining whether to grant approval to use Method 23, the 
Administrator may consider factors including whether dioxin/furan were 
detected at levels substantially below the emission standard in 
previous testing, and whether previous Method 0023 analyses detected 
low levels of dioxin/furan in the front half of the sampling train.
    (3) Sources that emit carbonaceous particulate matter, such as 
coal-fired boilers, and sources equipped with activated carbon 
injection, will be deemed not suitable for use of Method 23 unless you 
document that there would not be a significant improvement in quality 
assurance with Method 0023A.
* * * * *
    (5) Hydrogen chloride and chlorine gas--(i) Compliance with MACT 
standards. To determine compliance with the emission standard for 
hydrogen chloride and chlorine gas (combined), you must use:
    (A) Method 26/26A as provided in appendix A, part 60 of this 
chapter; or
    (B) Methods 320 or 321 as provided in appendix A, part 63 of this 
chapter, or

[[Page 59548]]

    (C) ASTM D 6735-01, Standard Test Method for Measurement of Gaseous 
Chlorides and Fluorides from Mineral Calcining Exhaust Sources--
Impinger Method to measure emissions of hydrogen chloride, and Method 
26/26A to measure emissions of chlorine gas, provided that you follow 
the provisions in paragraphs (b)(5)(C)(1) through (6) of this section. 
ASTM D 6735-01 is available for purchase from at least one of the 
following addresses: American Society for Testing and Materials (ASTM), 
100 Barr Harbor Drive, Post Office Box C700, West Conshohocken, PA 
19428-2959; or ProQuest, 300 North Zeeb Road, Ann Arbor, MI 48106.
    (1) A test must include three or more runs in which a pair of 
samples is obtained simultaneously for each run according to section 
11.2.6 of ASTM Method D6735-01.
    (2) You must calculate the test run standard deviation of each set 
of paired samples to quantify data precision, according to Equation 1 
of this section:
[GRAPHIC] [TIFF OMITTED] TR12OC05.001

Where:

RSD<INF>a</INF> = The test run relative standard deviation of sample 
pair a, percent.
C1<INF>a</INF> and C2<INF>a</INF> = The HCl concentrations, milligram/
dry standard cubic meter (mg/dscm), from the paired samples.

    (3) You must calculate the test average relative standard deviation 
according to Equation 2 of this section:
[GRAPHIC] [TIFF OMITTED] TR12OC05.002

Where:

RSD<INF>TA</INF> = The test average relative standard deviation, 
percent.
RSD<INF>a</INF> = The test run relative standard deviation for sample 
pair a.
p = The number of test runs, >=3.

    (4) If RSDTA is greater than 20 percent, the data are invalid and 
the test must be repeated.
    (5) The post-test analyte spike procedure of section 11.2.7 of ASTM 
Method D6735-01 is conducted, and the percent recovery is calculated 
according to section 12.6 of ASTM Method D6735-01.
    (6) If the percent recovery is between 70 percent and 130 percent, 
inclusive, the test is valid. If the percent recovery is outside of 
this range, the data are considered invalid, and the test must be 
repeated.
    (ii) Compliance with risk-based limits under Sec.  63.1215. To 
demonstrate compliance with emission limits established under Sec.  
63.1215, you must use Method 26/26A as provided in appendix A, part 60 
of this chapter, Method 320 as provided in appendix A, part 63 of this 
chapter, Method 321 as provided in appendix A, part 63 of this chapter, 
or ASTM D 6735-01, Standard Test Method for Measurement of Gaseous 
Chlorides and Fluorides from Mineral Calcining Exhaust Sources--
Impinger Method (following the provisions of paragraphs (b)(5)(C)(1) 
through (6) of this section), except:
    (A) For cement kilns and sources equipped with a dry acid gas 
scrubber, you must use Methods 320 or 321 as provided in appendix A, 
part 63 of this chapter, or ASTM D 6735-01 to measure hydrogen 
chloride, and the back-half, caustic impingers of Method 26/26A as 
provided in appendix A, part 60 of this chapter to measure chlorine 
gas; and
    (B) For incinerators, boilers, and lightweight aggregate kilns, you 
must use Methods 320 or 321 as provided in appendix A, part 63 of this 
chapter, or ASTM D 6735-01 to measure hydrogen chloride, and Method 26/
26A as provided in appendix A, part 60 of this chapter to measure total 
chlorine, and calculate chlorine gas by difference if:
    (1) The bromine/chlorine ratio in feedstreams is greater than 5 
percent; or
    (2) The sulfur/chlorine ratio in feedstreams is greater than 50 
percent.
* * * * *

0
11. Section 63.1209 is amended by:
0
a. Revising paragraphs (a)(1)(ii), (a)(1)(iv)(D), (a)(1)(v)(D), and 
(a)(5).
0
b. Revising paragraph (b)(2)(ii).
0
c. Revising the heading of paragraph (g)(1) introductory text and 
paragraph (g)(1)(i).
0
d. Adding paragraph (g)(1)(iv).
0
e. Revising paragraphs (k)(1)(i) and (k)(2)(i).
0
f. Revising paragraph (l)(1).
0
g. Revising paragraphs (m)(1)(iv) introductory text and (m)(3).
0
h. Revising paragraph (n)(2).
0
i. Revising the heading of paragraph (o) introductory text and 
paragraph (o)(1).
0
j. Adding paragraph (r).
    The revisions read as follows:


Sec.  63.1209  What are the monitoring requirements?

    (a) * * *
    (1) * * *
    (ii) (A) Cement kilns under Sec.  63.1204--Except as provided by 
paragraphs (a)(1)(iv) and (a)(1)(v) of the section, you must use a COMS 
to demonstrate and monitor compliance with the opacity standard under 
Sec. Sec.  63.1204(a)(7) and (b)(7) at each point where emissions are 
vented from these affected sources including the bypass stack of a 
preheater or preheater/precalciner kiln with dual stacks.
    (B) Cement kilns under Sec.  63.1220--Except as provided by 
paragraphs (a)(1)(iv) and (a)(1)(v) of the section and unless your 
source is equipped with a bag leak detection system under Sec.  
63.1206(c)(8) or a particulate matter detection system under Sec.  
63.1206(c)(9), you must use a COMS to demonstrate and monitor 
compliance with the opacity standard under Sec. Sec.  63.1220(a)(7) and 
(b)(7) at each point where emissions are vented from these affected 
sources including the bypass stack of a preheater or preheater/
precalciner kiln with dual stacks.
    (C) You must maintain and operate each COMS in accordance with the 
requirements of Sec.  63.8(c) except for the requirements under Sec.  
63.8(c)(3). The requirements of Sec.  63.1211(c) shall be complied with 
instead of Sec.  63.8(c)(3); and
    (D) Compliance is based on a six-minute block average.
* * * * *
    (iv) * * *
    (D) To remain in compliance, all six-minute block averages must not 
exceed the opacity standard.
    (v) * * *
    (D) To remain in compliance, all six-minute block averages must not 
exceed the opacity standard.
* * * * *
    (5) Petitions to use CEMS for other standards. You may petition the 
Administrator to use CEMS for compliance monitoring for particulate 
matter, mercury, semivolatile metals, low volatile metals, and hydrogen 
chloride and chlorine gas under Sec.  63.8(f) in lieu of compliance 
with the corresponding operating parameter limits under this section.
* * * * *
    (b) * * *
    (2) * * *

[[Page 59549]]

    (ii) Accuracy and calibration of weight measurement devices for 
activated carbon injection systems. If you operate a carbon injection 
system, the accuracy of the weight measurement device must be <plus-
minus> 1 percent of the weight being measured. The calibration of the 
device must be verified at least once each calendar quarter at a 
frequency of approximately 120 days.
* * * * *
    (g) * * *
    (1) Requests to use alternatives to operating parameter monitoring 
requirements. (i) You may submit an application to the Administrator 
under this paragraph for approval of alternative operating parameter 
monitoring requirements to document compliance with the emission 
standards of this subpart. For requests to use additional CEMS, 
however, you must use paragraph (a)(5) of this section and Sec.  
63.8(f). Alternative requests to operating parameter monitoring 
requirements that include unproven monitoring methods may not be made 
under this paragraph and must be made under Sec.  63.8(f).
* * * * *
    (iv) Dual Standards that incorporate the Interim Standards for HAP 
metals. (A) Semivolatile and Low Volatile Metals. You may petition the 
Administrator to waive a feedrate operating parameter limit under 
paragraph (n)(2) of this section for either the emission standards 
expressed in a thermal emissions format or the interim standards based 
on documentation that the feedrate operating parameter limit is not 
needed to ensure compliance with the relevant standard on a continuous 
basis.
    (B) Mercury. You may petition the Administrator to waive a feedrate 
operating parameter limit under paragraph (l)(1) of this section for 
either the feed concentration standard under Sec. Sec.  
63.1220(a)(2)(i) and (b)(2)(i) or the interim standards based on 
documentation that the feedrate operating parameter limit is not needed 
to ensure compliance with the relevant standard on a continuous basis.
* * * * *
    (k) * * *
    (1) * * * (i) For sources other than a lightweight aggregate kiln, 
if the combustor is equipped with an electrostatic precipitator, 
baghouse (fabric filter), or other dry emissions control device where 
particulate matter is suspended in contact with combustion gas, you 
must establish a limit on the maximum temperature of the gas at the 
inlet to the device on an hourly rolling average. You must establish 
the hourly rolling average limit as the average of the test run 
averages.
* * * * *
    (2) * * * (i) For sources other than cement kilns, you must measure 
the temperature of each combustion chamber at a location that best 
represents, as practicable, the bulk gas temperature in the combustion 
zone. You must document the temperature measurement location in the 
test plan you submit under Sec. Sec.  63.1207(e) and (f);
* * * * *
    (l) Mercury. * * *
    (1) Feedrate of mercury. (i) For incinerators and solid fuel 
boilers, when complying with the mercury emission standards under 
Sec. Sec.  63.1203, 63.1216 and 63.1219, you must establish a 12-hour 
rolling average limit for the total feedrate of mercury in all 
feedstreams as the average of the test run averages.
    (ii) For liquid fuel boilers, when complying with the mercury 
emission standards of Sec.  63.1217, you must establish a rolling 
average limit for the mercury feedrate as follows on an averaging 
period not to exceed an annual rolling average:
    (A) You must calculate a mercury system removal efficiency for each 
test run and calculate the average system removal efficiency of the 
test run averages. If emissions exceed the mercury emission standard 
during the comprehensive performance test, it is not a violation 
because the averaging period for the mercury emission standard is (not-
to-exceed) one year and compliance is based on compliance with the 
mercury feedrate limit with an averaging period not-to-exceed one year.
    (B) If you burn hazardous waste with a heating value of 10,000 Btu/
lb or greater, you must calculate the mercury feedrate limit as 
follows:
    (1) The mercury feedrate limit is the emission standard divided by 
[1 - system removal efficiency].
    (2) The mercury feedrate limit is a hazardous waste thermal 
concentration limit expressed as pounds of mercury in hazardous waste 
feedstreams per million Btu of hazardous waste fired.
    (3) You must comply with the hazardous waste mercury thermal 
concentration limit by determining the feedrate of mercury in all 
hazardous waste feedstreams (lb/hr) at least once a minute and the 
hazardous waste thermal feedrate (MM Btu/hr) at least once a minute to 
calculate a 60-minute average thermal emission concentration as 
[hazardous waste mercury feedrate (lb/hr) / hazardous waste thermal 
feedrate (MM Btu/hr)].
    (4) You must calculate a rolling average hazardous waste mercury 
thermal concentration that is updated each hour.
    (5) If you select an averaging period for the feedrate limit that 
is greater than a 12-hour rolling average, you must calculate the 
initial rolling average as though you had selected a 12-hour rolling 
average, as provided by paragraph (b)(5)(i) of this section. You must 
calculate rolling averages thereafter as the average of the available 
one-minute values until enough one-minute values are available to 
calculate the rolling average period you select. At that time and 
thereafter, you update the rolling average feedrate each hour with a 
60-minute average feedrate.
    (C) If you burn hazardous waste with a heating value of less than 
10,000 Btu/lb, you must calculate the mercury feedrate limit as 
follows:
    (1) You must calculate the mercury feedrate limit as the mercury 
emission standard divided by [1 - System Removal Efficiency].
    (2) The feedrate limit is expressed as a mass concentration per 
unit volume of stack gas ([mu]g/dscm) and is converted to a mass 
feedrate (lb/hr) by multiplying it by the average stack gas flowrate of 
the test run averages.
    (3) You must comply with the feedrate limit by determining the 
mercury feedrate (lb/hr) at least once a minute to calculate a 60-
minute average feedrate.
    (4) You must update the rolling average feedrate each hour with 
this 60-minute feedrate measurement.
    (5) If you select an averaging period for the feedrate limit that 
is greater than a 12-hour rolling average, you must calculate the 
initial rolling average as though you had selected a 12-hour rolling 
average, as provided by paragraph (b)(5)(i) of this section. You must 
calculate rolling averages thereafter as the average of the available 
one-minute values until enough one-minute values are available to 
calculate the rolling average period you select. At that time and 
thereafter, you update the rolling average feedrate each hour with a 
60-minute average feedrate.
    (D) If your boiler is equipped with a wet scrubber, you must comply 
with the following unless you document in the performance test plan 
that you do not feed chlorine at rates that may substantially affect 
the system removal efficiency of mercury for purposes of establishing a 
mercury feedrate limit based on the system removal efficiency during 
the test:
    (1) Scrubber blowdown must be minimized during a pretest 
conditioning period and during the performance test:
    (2) Scrubber water must be preconditioned so that mercury in the

[[Page 59550]]

water is at equilibrium with stack gas at the mercury feedrate level of 
the performance test; and
    (3) You must establish an operating limit on minimum pH of scrubber 
water as the average of the test run averages and comply with the limit 
on an hourly rolling average.
    (iii) For cement kilns:
    (A) When complying with the emission standards under Sec. Sec.  
63.1220(a)(2)(i) and (b)(2)(i), you must:
    (1) Comply with the mercury hazardous waste feed concentration 
operating requirement on a twelve-hour rolling average;
    (2) Monitor and record in the operating record the as-fired mercury 
concentration in the hazardous waste (or the weighted-average mercury 
concentration for multiple hazardous waste feedstreams);
    (3) Initiate an automatic waste feed cutoff that immediately and 
automatically cuts off the hazardous waste feed when the as-fired 
mercury concentration operating requirement is exceeded;
    (B) When complying with the emission standards under Sec. Sec.  
63.1204, 63.1220(a)(2)(ii) and (b)(2)(ii), you must establish a 12-hour 
rolling average limit for the total feedrate of mercury in all 
feedstreams as the average of the test run averages;
    (C) Except as provided by paragraph (l)(1)(iii)(D) of this section, 
when complying with the hazardous waste feedrate corresponding to a 
maximum theoretical emission concentration (MTEC) under Sec. Sec.  
63.1220(a)(2)(iii) and (b)(2)(iii), you must:
    (1) Comply with the MTEC operating requirement on a twelve-hour 
rolling average;
    (2) Monitor and record the feedrate of mercury for each hazardous 
waste feedstream according to Sec.  63.1209(c);
    (3) Monitor with a CMS and record in the operating record the gas 
flowrate (either directly or by monitoring a surrogate parameter that 
you have correlated to gas flowrate);
    (4) Continuously calculate and record in the operating record a 
MTEC assuming mercury from all hazardous waste feedstreams is emitted;
    (5) Initiate an automatic waste feed cutoff that immediately and 
automatically cuts off the hazardous waste feed when the MTEC operating 
requirement is exceeded;
    (D) In lieu of complying with paragraph (l)(1)(iii)(C) of this 
section, you may:
    (1) Identify in the Notification of Compliance a minimum gas 
flowrate limit and a maximum feedrate limit of mercury from all 
hazardous waste feedstreams that ensures the MTEC calculated in 
paragraph (l)(1)(iii)(B)(4) of this section is below the operating 
requirement under paragraphs Sec. Sec.  63.1220(a)(2)(iii) and 
(b)(2)(iii); and
    (2) Initiate an automatic waste feed cutoff that immediately and 
automatically cuts off the hazardous waste feed when either the gas 
flowrate or mercury feedrate exceeds the limits identified in paragraph 
(l)(1)(iv)(D)(1) of this section.
    (iv) For lightweight aggregate kilns:
    (A) When complying with the emission standards under Sec. Sec.  
63.1205, 63.1221(a)(2)(i) and (b)(2)(i), you must establish a 12-hour 
rolling average limit for the total feedrate of mercury in all 
feedstreams as the average of the test run averages;
    (B) Except as provided by paragraph (l)(1)(iv)(C) of this section, 
when complying with the hazardous waste feedrate corresponding to a 
maximum theoretical emission concentration (MTEC) under Sec. Sec.  
63.1221(a)(2)(ii) and (b)(2)(ii), you must:
    (1) Comply with the MTEC operating requirement on a twelve-hour 
rolling average;
    (2) Monitor and record the feedrate of mercury for each hazardous 
waste feedstream according to Sec.  63.1209(c);
    (3) Monitor with a CMS and record in the operating record the gas 
flowrate (either directly or by monitoring a surrogate parameter that 
you have correlated to gas flowrate);
    (4) Continuously calculate and record in the operating record a 
MTEC assuming mercury from all hazardous waste feedstreams is emitted;
    (5) Initiate an automatic waste feed cutoff that immediately and 
automatically cuts off the hazardous waste feed when the MTEC operating 
requirement is exceeded;
    (C) In lieu of complying with paragraph (l)(1)(iv)(B) of this 
section, you may:
    (1) Identify in the Notification of Compliance a minimum gas 
flowrate limit and a maximum feedrate limit of mercury from all 
hazardous waste feedstreams that ensures the MTEC calculated in 
paragraph (l)(1)(iv)(B)(4) of this section is below the operating 
requirement under paragraphs Sec. Sec.  63.1221(a)(2)(ii) and 
(b)(2)(ii); and
    (2) Initiate an automatic waste feed cutoff that immediately and 
automatically cuts off the hazardous waste feed when either the gas 
flowrate or mercury feedrate exceeds the limits identified in paragraph 
(l)(1)(iv)(C)(1) of this section.
    (v) Extrapolation of feedrate levels. In lieu of establishing 
mercury feedrate limits as specified in paragraphs (l)(1)(i) through 
(iv) of this section, you may request as part of the performance test 
plan under Sec. Sec.  63.7(b) and (c) and Sec. Sec.  63.1207 (e) and 
(f) to use the mercury feedrates and associated emission rates during 
the comprehensive performance test to extrapolate to higher allowable 
feedrate limits and emission rates. The extrapolation methodology will 
be reviewed and approved, as warranted, by the Administrator. The 
review will consider in particular whether:
    (A) Performance test metal feedrates are appropriate (i.e., whether 
feedrates are at least at normal levels; depending on the heterogeneity 
of the waste, whether some level of spiking would be appropriate; and 
whether the physical form and species of spiked material is 
appropriate); and
    (B) Whether the extrapolated feedrates you request are warranted 
considering historical metal feedrate data.
* * * * *
    (m) * * *
    (1) * * *
    (iv) Other particulate matter control devices. For each particulate 
matter control device that is not a fabric filter or high energy wet 
scrubber, or is not an electrostatic precipitator or ionizing wet 
scrubber for which you elect to monitor particulate matter loadings 
under Sec.  63.1206(c)(9) of this chapter for process control, you must 
ensure that the control device is properly operated and maintained as 
required by Sec.  63.1206(c)(7) and by monitoring the operation of the 
control device as follows:
* * * * *
    (3) Maximum ash feedrate. Owners and operators of hazardous waste 
incinerators, solid fuel boilers, and liquid fuel boilers must 
establish a maximum ash feedrate limit as a 12-hour rolling average 
based on the average of the test run averages. This requirement is 
waived, however, if you comply with the particulate matter detection 
system requirements under Sec.  63.1206(c)(9).
    (n) * * *
    (2) Maximum feedrate of semivolatile and low volatile metals. (i) 
General. You must establish feedrate limits for semivolatile metals 
(cadmium and lead) and low volatile metals (arsenic, beryllium, and 
chromium) as follows, except as provided by paragraph (n)(2)(vii) of 
this section.
    (ii) For incinerators, cement kilns, and lightweight aggregate 
kilns, when complying with the emission standards under Sec. Sec.  
63.1203, 63.1204, 63.1205, and 63.1219, and for solid fuel boilers when 
complying with the emission standards

[[Page 59551]]

under Sec.  63.1216, you must establish 12-hour rolling average limits 
for the total feedrate of semivolatile and low volatile metals in all 
feedstreams as the average of the test run averages.
    (iii) Cement kilns under Sec.  63.1220--(A) When complying with the 
emission standards under Sec. Sec.  63.1220(a)(3)(i), (a)(4)(i), 
(b)(3)(i), and (b)(4)(i), you must establish 12-hour rolling average 
feedrate limits for semivolatile and low volatile metals as the thermal 
concentration of semivolatile metals or low volatile metals in all 
hazardous waste feedstreams. You must calculate hazardous waste thermal 
concentrations for semivolatile metals and low volatile metals for each 
run as the total mass feedrate of semivolatile metals or low volatile 
metals for all hazardous waste feedstreams divided by the total heat 
input rate for all hazardous waste feedstreams. The 12-hour rolling 
average feedrate limits for semivolatile metals and low volatile metals 
are the average of the hazardous waste thermal concentrations for the 
runs.
    (B) When complying with the emission standards under Sec. Sec.  
63.1220(a)(3)(ii), (a)(4)(ii), (b)(3)(ii), and (b)(4)(ii), you must 
establish 12-hour rolling average limits for the total feedrate of 
semivolatile and low volatile metals in all feedstreams as the average 
of the test run averages.
    (iv) Lightweight aggregate kilns under Sec.  63.1221--(A) When 
complying with the emission standards under Sec. Sec.  
63.1221(a)(3)(i), (a)(4)(i), (b)(3)(i), and (b)(4)(i), you must 
establish 12-hour rolling average feedrate limits for semivolatile and 
low volatile metals as the thermal concentration of semivolatile metals 
or low volatile metals in all hazardous waste feedstreams as specified 
in paragraphs (n)(2)(iii)(A) of this section.
    (B) When complying with the emission standards under Sec. Sec.  
63.1221(a)(3)(ii), (a)(4)(ii), (b)(3)(ii), and (b)(4)(ii), you must 
establish 12-hour rolling average limits for the total feedrate of 
semivolatile and low volatile metals in all feedstreams as the average 
of the test run averages.
    (v) Liquid fuel boilers under Sec.  63.1217. (A) Semivolatile 
metals. You must establish a rolling average limit for the semivolatile 
metal feedrate as follows on an averaging period not to exceed an 
annual rolling average.
    (1) System removal efficiency. You must calculate a semivolatile 
metal system removal efficiency for each test run and calculate the 
average system removal efficiency of the test run averages. If 
emissions exceed the semivolatile metal emission standard during the 
comprehensive performance test, it is not a violation because the 
averaging period for the semivolatile metal emission standard is one 
year and compliance is based on compliance with the semivolatile metal 
feedrate limit that has an averaging period not to exceed an annual 
rolling average.
    (2) Boilers that feed hazardous waste with a heating value of 
10,000 Btu/lb or greater. You must calculate the semivolatile metal 
feedrate limit as the semivolatile metal emission standard divided by 
[1 - System Removal Efficiency].
    (i) The feedrate limit is a hazardous waste thermal concentration 
limit expressed as pounds of semivolatile metals in all hazardous waste 
feedstreams per million Btu of hazardous waste fed to the boiler.
    (ii) You must comply with the hazardous waste semivolatile metal 
thermal concentration limit by determining the feedrate of semivolatile 
metal in all hazardous waste feedstreams (lb/hr) and the hazardous 
waste thermal feedrate (MM Btu/hr) at least once a minute to calculate 
a 60-minute average thermal emission concentration as [hazardous waste 
semivolatile metal feedrate (lb/hr) / hazardous waste thermal feedrate 
(MM Btu/hr)].
    (iii) You must calculate a rolling average hazardous waste 
semivolatile metal thermal concentration that is updated each hour.
    (iv) If you select an averaging period for the feedrate limit that 
is greater than a 12-hour rolling average, you must calculate the 
initial rolling average as though you had selected a 12-hour rolling 
average, as provided by paragraph (b)(5)(i) of this section. You must 
calculate rolling averages thereafter as the average of the available 
one-minute values until enough one-minute values are available to 
calculate the rolling average period you select. At that time and 
thereafter, you update the rolling average feedrate each hour with a 
60-minute average feedrate.
    (3) Boilers that feed hazardous waste with a heating value less 
than 10,000 Btu/lb. (i) You must calculate the semivolatile metal 
feedrate limit as the semivolatile metal emission standard divided by 
[1 - System Removal Efficiency].
    (ii) The feedrate limit is expressed as a mass concentration per 
unit volume of stack gas ([mu]g/dscm) and is converted to a mass 
feedrate (lb/hr) by multiplying it by the average stack gas flowrate 
(dscm/hr) of the test run averages.
    (iii) You must comply with the feedrate limit by determining the 
semivolatile metal feedrate (lb/hr) at least once a minute to calculate 
a 60-minute average feedrate.
    (iv) You must update the rolling average feedrate each hour with 
this 60-minute feedrate measurement.
    (v) If you select an averaging period for the feedrate limit that 
is greater than a 12-hour rolling average, you must calculate the 
initial rolling average as though you had selected a 12-hour rolling 
average, as provided by paragraph (b)(5)(i) of this section. You must 
calculate rolling averages thereafter as the average of the available 
one-minute values until enough one-minute values are available to 
calculate the rolling average period you select. At that time and 
thereafter, you update the rolling average feedrate each hour with a 
60-minute average feedrate.
    (B) Chromium. (1) Boilers that feed hazardous waste with a heating 
value of 10,000 Btu/lb or greater. (i) The feedrate limit is a 
hazardous waste thermal concentration limit expressed as pounds of 
chromium in all hazardous waste feedstreams per million Btu of 
hazardous waste fed to the boiler.
    (ii) You must comply with the hazardous waste chromium thermal 
concentration limit by determining the feedrate of chromium in all 
hazardous waste feedstreams (lb/hr) and the hazardous waste thermal 
feedrate (MM Btu/hr) at least once a minute to calculate a 60-minute 
average thermal emission concentration as [hazardous waste chromium 
feedrate (lb/hr) / hazardous waste thermal feedrate (MM Btu/hr)]. You 
must update the rolling average feedrate each hour with this 60-minute 
average feedrate measurement.
    (2) Boilers that feed hazardous waste with a heating value less 
than 10,000 Btu/lb. You must establish a 12-hour rolling average limit 
for the total feedrate (lb/hr) of chromium in all feedstreams as the 
average of the test run averages. You must update the rolling average 
feedrate each hour with a 60-minute average feedrate measurement.
    (vi) LVM limits for pumpable wastes. You must establish separate 
feedrate limits for low volatile metals in pumpable feedstreams using 
the procedures prescribed above for total low volatile metals. Dual 
feedrate limits for both pumpable and total feedstreams are not 
required, however, if you base the total feedrate limit solely on the 
feedrate of pumpable feedstreams.
    (vii) Extrapolation of feedrate levels. In lieu of establishing 
feedrate limits as specified in paragraphs (l)(1)(i) through (iii) of 
this section, you may request as part of the performance test plan 
under Sec. Sec.  63.7(b) and (c) and Sec. Sec.  63.1207(e) and (f) to 
use the semivolatile metal and low

[[Page 59552]]

volatile metal feedrates and associated emission rates during the 
comprehensive performance test to extrapolate to higher allowable 
feedrate limits and emission rates. The extrapolation methodology will 
be reviewed and approved, as warranted, by the Administrator. The 
review will consider in particular whether:
    (A) Performance test metal feedrates are appropriate (i.e., whether 
feedrates are at least at normal levels; depending on the heterogeneity 
of the waste, whether some level of spiking would be appropriate; and 
whether the physical form and species of spiked material is 
appropriate); and
    (B) Whether the extrapolated feedrates you request are warranted 
considering historical metal feedrate data.
* * * * *
    (o) Hydrogen chloride and chlorine gas. * * *
    (1) Feedrate of total chlorine and chloride. (i) Incinerators, 
cement kilns, lightweight aggregate kilns, solid fuel boilers, and 
hydrochloric acid production furnaces. You must establish a 12-hour 
rolling average limit for the total feedrate of chlorine (organic and 
inorganic) in all feedstreams as the average of the test run averages.
    (ii) Liquid fuel boilers. (A) Boilers that feed hazardous waste 
with a heating value not less than 10,000 Btu/lb. (1) The feedrate 
limit is a hazardous waste thermal concentration limit expressed as 
pounds of chlorine (organic and inorganic) in all hazardous waste 
feedstreams per million Btu of hazardous waste fed to the boiler.
    (2) You must establish a 12-hour rolling average feedrate limit as 
the average of the test run averages.
    (3) You must comply with the feedrate limit by determining the mass 
feedrate of hazardous waste feedstreams (lb/hr) at least once a minute 
and by knowing the chlorine (organic and inorganic) content and heating 
value (million Btu/lb) of hazardous waste feedstreams at all times to 
calculate a 60-minute average feedrate measurement as [hazardous waste 
chlorine feedrate (lb/hr) / hazardous waste thermal feedrate (million 
Btu/hr)]. You must update the rolling average feedrate each hour with 
this 60-minute average feedrate measurement.
    (B) Boilers that feed hazardous waste with a heating value less 
than 10,000 Btu/lb. You must establish a 12-hour rolling average limit 
for the total feedrate of chlorine (organic and inorganic) in all 
feedstreams as the average of the test run averages. You must update 
the rolling average feedrate each hour with a 60-minute average 
feedrate measurement.
* * * * *
    (r) Averaging periods. The averaging periods specified in this 
section for operating parameters are not-to-exceed averaging periods. 
You may elect to use shorter averaging periods. For example, you may 
elect to use a 1-hour rolling average rather than the 12-hour rolling 
average specified in paragraph (l)(1)(i) of this section for mercury.

0
12. Section 63.1210 is amended by:
0
a. Revising the table in paragraph (a)(1) and the table in paragraph 
(a)(2).
0
b. Redesignating paragraph (b) as (d).
0
c. Adding new paragraph (b).
0
d. Adding new paragraph (c).
    The revisions and additions read as follows:


Sec.  63.1210  What are the notification requirements?

    (a) * * *
    (1) * * *

----------------------------------------------------------------------------------------------------------------
                           Reference                                               Notification
----------------------------------------------------------------------------------------------------------------
63.9(b)........................................................  Initial notifications that you are subject to
                                                                  Subpart EEE of this Part.
63.9(d)........................................................  Notification that you are subject to special
                                                                  compliance requirements.
63.9(j)........................................................  Notification and documentation of any change in
                                                                  information already provided under Sec.
                                                                  63.9.
63.1206(b)(5)(i)...............................................  Notification of changes in design, operation,
                                                                  or maintenance.
63.1206(c)(7)(ii)(C)...........................................  Notification of excessive bag leak detection
                                                                  system exceedances.
63.1207(e), 63.9(e) 63.9(g)(1) and (3).........................  Notification of performance test and continuous
                                                                  monitoring system evaluation, including the
                                                                  performance test plan and CMS performance
                                                                  evaluation plan.\1\
63.1210(b).....................................................  Notification of intent to comply.
63.1210(d), 63.1207(j), 63.1207(k), 63.1207(l), 63.9(h),         Notification of compliance, including results
 63.10(d)(2), 63.10(e)(2).                                        of performance tests and continuous monitoring
                                                                  system performance evaluations.
----------------------------------------------------------------------------------------------------------------
\1\ You may also be required on a case-by-case basis to submit a feedstream analysis plan under Sec.
  63.1209(c)(3).

    (2) * * *

----------------------------------------------------------------------------------------------------------------
                                                                 Notification, request, petition, or application
                           Reference                                                    6
----------------------------------------------------------------------------------------------------------------
63.9(i)........................................................  You may request an adjustment to time periods
                                                                  or postmark deadlines for submittal and review
                                                                  of required information.
63.10(e)(3)(ii)................................................  You may request to reduce the frequency of
                                                                  excess emissions and CMS performance reports.
63.10(f).......................................................  You may request to waive recordkeeping or
                                                                  reporting requirements.
63.1204(d)(2)(iii), 63.1220(d)(2)(iii).........................  Notification that you elect to comply with the
                                                                  emission averaging requirements for cement
                                                                  kilns with in-line raw mills.
63.1204(e)(2)(iii), 63.1220(e)(2)(iii).........................  Notification that you elect to comply with the
                                                                  emission averaging requirements for preheater
                                                                  or preheater/precalciner kilns with dual
                                                                  stacks.
63.1206(b)(4), 63.1213, 63.6(i), 63.9(c).......................  You may request an extension of the compliance
                                                                  date for up to one year.
63.1206(b)(5)(i)(C)............................................  You may request to burn hazardous waste for
                                                                  more than 720 hours and for purposes other
                                                                  than testing or pretesting after making a
                                                                  change in the design or operation that could
                                                                  affect compliance with emission standards and
                                                                  prior to submitting a revised Notification of
                                                                  Compliance.
63.1206(b)(8)(iii)(B)..........................................  If you elect to conduct particulate matter CEMS
                                                                  correlation testing and wish to have federal
                                                                  particulate matter and opacity standards and
                                                                  associated operating limits waived during the
                                                                  testing, you must notify the Administrator by
                                                                  submitting the correlation test plan for
                                                                  review and approval.
63.1206(b)(8)(v)...............................................  You may request approval to have the
                                                                  particulate matter and opacity standards and
                                                                  associated operating limits and conditions
                                                                  waived for more than 96 hours for a
                                                                  correlation test.

[[Page 59553]]

 
63.1206(b)(9)..................................................  Owners and operators of lightweight aggregate
                                                                  kilns may request approval of alternative
                                                                  emission standards for mercury, semivolatile
                                                                  metal, low volatile metal, and hydrogen
                                                                  chloride/chlorine gas under certain
                                                                  conditions.
63.1206(b)(10).................................................  Owners and operators of cement kilns may
                                                                  request approval of alternative emission
                                                                  standards for mercury, semivolatile metal, low
                                                                  volatile metal, and hydrogen chloride/chlorine
                                                                  gas under certain conditions.
63.1206(b)(14).................................................  Owners and operators of incinerators may elect
                                                                  to comply with an alternative to the
                                                                  particulate matter standard.
63.1206(b)(15).................................................  Owners and operators of cement and lightweight
                                                                  aggregate kilns may request to comply with the
                                                                  alternative to the interim standards for
                                                                  mercury.
63.1206(c)(2)(ii)(C)...........................................  You may request to make changes to the startup,
                                                                  shutdown, and malfunction plan.
63.1206(c)(5)(i)(C)............................................  You may request an alternative means of control
                                                                  to provide control of combustion system leaks.
63.1206(c)(5)(i)(D)............................................  You may request other techniques to prevent
                                                                  fugitive emissions without use of
                                                                  instantaneous pressure limits.
63.1207(c)(2)..................................................  You may request to base initial compliance on
                                                                  data in lieu of a comprehensive performance
                                                                  test.
63.1207(d)(3)..................................................  You may request more than 60 days to complete a
                                                                  performance test if additional time is needed
                                                                  for reasons beyond your control.
63.1207(e)(3), 63.7(h).........................................  You may request a time extension if the
                                                                  Administrator fails to approve or deny your
                                                                  test plan.
63.1207(h)(2)..................................................  You may request to waive current operating
                                                                  parameter limits during pretesting for more
                                                                  than 720 hours.
63.1207(f)(1)(ii)(D)...........................................  You may request a reduced hazardous waste
                                                                  feedstream analysis for organic hazardous air
                                                                  pollutants if the reduced analysis continues
                                                                  to be representative of organic hazardous air
                                                                  pollutants in your hazardous waste
                                                                  feedstreams.
63.1207(g)(2)(v)...............................................  You may request to operate under a wider
                                                                  operating range for a parameter during
                                                                  confirmatory performance testing.
63.1207(i).....................................................  You may request up to a one-year time extension
                                                                  for conducting a performance test (other than
                                                                  the initial comprehensive performance test) to
                                                                  consolidate testing with other state or
                                                                  federally-required testing.
63.1207(j)(4)..................................................  You may request more than 90 days to submit a
                                                                  Notification of Compliance after completing a
                                                                  performance test if additional time is needed
                                                                  for reasons beyond your control.
63.1207(l)(3)..................................................  After failure of a performance test, you may
                                                                  request to burn hazardous waste for more than
                                                                  720 hours and for purposes other than testing
                                                                  or pretesting.
63.1209(a)(5), 63.8(f).........................................  You may request: (1) Approval of alternative
                                                                  monitoring methods for compliance with
                                                                  standards that are monitored with a CEMS; and
                                                                  (2) approval to use a CEMS in lieu of
                                                                  operating parameter limits.
63.1209(g)(1)..................................................  You may request approval of: (1) Alternatives
                                                                  to operating parameter monitoring
                                                                  requirements, except for standards that you
                                                                  must monitor with a continuous emission
                                                                  monitoring system (CEMS) and except for
                                                                  requests to use a CEMS in lieu of operating
                                                                  parameter limits; or (2) a waiver of an
                                                                  operating parameter limit.
63.1209(l)(1)..................................................  You may request to extrapolate mercury feedrate
                                                                  limits.
63.1209(n)(2)..................................................  You may request to extrapolate semivolatile and
                                                                  low volatile metal feedrate limits.
63.1211(d).....................................................  You may request to use data compression
                                                                  techniques to record data on a less frequent
                                                                  basis than required by Sec.   63.1209.
----------------------------------------------------------------------------------------------------------------

    (b) Notification of intent to comply (NIC). These procedures apply 
to sources that have not previously complied with the requirements of 
paragraph (b) of this section, and to sources that previously complied 
with the NIC requirements of Sec.  63.1210, which were in effect prior 
to October 11, 2000, that must make a technology change requiring a 
Class 1 permit modification to meet the standards of Sec. Sec.  
63.1219, 63.1220, and 63.1221.
    (1) You must prepare a Notification of Intent to Comply that 
includes all of the following information:
    (i) General information:
    (A) The name and address of the owner/operator and the source;
    (B) Whether the source is a major or an area source;
    (C) Waste minimization and emission control technique(s) being 
considered;
    (D) Emission monitoring technique(s) you are considering;
    (E) Waste minimization and emission control technique(s) 
effectiveness;
    (F) A description of the evaluation criteria used or to be used to 
select waste minimization and/or emission control technique(s); and
    (G) A general description of how you intend to comply with the 
emission standards of this subpart.
    (ii) As applicable to each source, information on key activities 
and estimated dates for these activities that will bring the source 
into compliance with emission control requirements of this subpart. You 
must include all of the following key activities and dates in your NIC:
    (A) The dates by which you anticipate you will develop engineering 
designs for emission control systems or process changes for emissions;
    (B) The date by which you anticipate you will commit internal or 
external resources for installing emission control systems or making 
process changes for emission control, or the date by which you will 
issue orders for the purchase of component parts to accomplish emission 
control or process changes.
    (C) The date by which you anticipate you will submit construction 
applications;
    (D) The date by which you anticipate you will initiate on-site 
construction, installation of emission control equipment, or process 
change;
    (E) The date by which you anticipate you will complete on-site 
construction, installation of emission control equipment, or process 
change; and
    (F) The date by which you anticipate you will achieve final 
compliance. The individual dates and milestones listed in paragraphs 
(b)(1)(ii)(A) through (F) of this section as part of the NIC are not 
requirements and therefore are not

[[Page 59554]]

enforceable deadlines; the requirements of paragraphs (b)(1)(ii)(A) 
through (F) of this section must be included as part of the NIC only to 
inform the public of how you intend to comply with the emission 
standards of this subpart.
    (iii) A summary of the public meeting required under paragraph (c) 
of this section;
    (iv) If you intend to cease burning hazardous waste prior to or on 
the compliance date, the requirements of paragraphs (b)(1)(ii) and 
(b)(1)(iii) of this section do not apply. You must include in your NIC 
a schedule of key dates for the steps to be taken to stop hazardous 
waste activity at your combustion unit. Key dates include the date for 
submittal of RCRA closure documents required under subpart G, part 264 
or subpart G, part 265 of this chapter.
    (2) You must make a draft of the NIC available for public review no 
later than 30 days prior to the public meeting required under paragraph 
(c)(1) of this section or no later than 9 months after the effective 
date of the rule if you intend to cease burning hazardous waste prior 
to or on the compliance date.
    (3) You must submit the final NIC to the Administrator no later 
than one year following the effective date of the emission standards of 
this subpart.
    (c) NIC public meeting and notice. (1) Prior to the submission of 
the NIC to the permitting agency, and no later than 10 months after the 
effective date of the emission standards of this subpart, you must hold 
at least one informal meeting with the public to discuss anticipated 
activities described in the draft NIC for achieving compliance with the 
emission standards of this subpart. You must post a sign-in sheet or 
otherwise provide a voluntary opportunity for attendees to provide 
their names and addresses;
    (2) You must submit a summary of the meeting, along with the list 
of attendees and their addresses developed under paragraph (b)(1) of 
this section, and copies of any written comments or materials submitted 
at the meeting, to the Administrator as part of the final NIC, in 
accordance with paragraph (b)(1)(iii) of this section;
    (3) You must provide public notice of the NIC meeting at least 30 
days prior to the meeting and you must maintain, and provide to the 
Administrator upon request, documentation of the notice. You must 
provide public notice in all of the following forms:
    (i) Newspaper advertisement. You must publish a notice in a 
newspaper of general circulation in the county or equivalent 
jurisdiction of your facility. In addition, you must publish the notice 
in newspapers of general circulation in adjacent counties or equivalent 
jurisdiction where such publication would be necessary to inform the 
affected public. You must publish the notice as a display 
advertisement.
    (ii) Visible and accessible sign. You must post a notice on a 
clearly marked sign at or near the source. If you place the sign on the 
site of the hazardous waste combustor, the sign must be large enough to 
be readable from the nearest spot where the public would pass by the 
site.
    (iii) Broadcast media announcement. You must broadcast a notice at 
least once on at least one local radio station or television station.
    (iv) Notice to the facility mailing list. You must provide a copy 
of the notice to the facility mailing list in accordance with Sec.  
124.10(c)(1)(ix) of this chapter.
    (4) You must include all of the following in the notices required 
under paragraph (c)(3) of this section:
    (i) The date, time, and location of the meeting;
    (ii) A brief description of the purpose of the meeting;
    (iii) A brief description of the source and proposed operations, 
including the address or a map (e.g., a sketched or copied street map) 
of the source location;
    (iv) A statement encouraging people to contact the source at least 
72 hours before the meeting if they need special access to participate 
in the meeting;
    (v) A statement describing how the draft NIC (and final NIC, if 
requested) can be obtained; and
    (vi) The name, address, and telephone number of a contact person 
for the NIC.
    (5) The requirements of this paragraph do not apply to sources that 
intend to cease burning hazardous waste prior to or on the compliance 
date.

0
13. Section 63.1211 is amended by:
0
a. Revising the table in paragraph (b).
0
b. Revising paragraph (c)(1).
    The revisions read as follows:


Sec.  63.1211  What are the recordkeeping and reporting requirements?

* * * * *
    (b) * * *

----------------------------------------------------------------------------------------------------------------
                           Reference                                      Document, Data, or Information
----------------------------------------------------------------------------------------------------------------
63.1200, 63.10(b) and (c)......................................  General. Information required to document and
                                                                  maintain compliance with the regulations of
                                                                  Subpart EEE, including data recorded by
                                                                  continuous monitoring systems (CMS), and
                                                                  copies of all notifications, reports, plans,
                                                                  and other documents submitted to the
                                                                  Administrator.
63.1204(d)(1)(ii), 63.1220(d)(1)(ii)...........................  Documentation of mode of operation changes for
                                                                  cement kilns with in-line raw mills.
63.1204(d)(2)(ii), 63.1220(d)(2)(ii)...........................  Documentation of compliance with the emission
                                                                  averaging requirements for cement kilns with
                                                                  in-line raw mills.
63.1204(e)(2)(ii), 63.1220(e)(2)(ii)...........................  Documentation of compliance with the emission
                                                                  averaging requirements for preheater or
                                                                  preheater/precalciner kilns with dual stacks.
63.1206(b)(1)(ii)..............................................  If you elect to comply with all applicable
                                                                  requirements and standards promulgated under
                                                                  authority of the Clean Air Act, including
                                                                  Sections 112 and 129, in lieu of the
                                                                  requirements of Subpart EEE when not burning
                                                                  hazardous waste, you must document in the
                                                                  operating record that you are in compliance
                                                                  with those requirements.
63.1206(b)(5)(ii)..............................................  Documentation that a change will not adversely
                                                                  affect compliance with the emission standards
                                                                  or operating requirements.
63.1206(b)(11).................................................  Calculation of hazardous waste residence time.
63.1206(c)(2)..................................................  Startup, shutdown, and malfunction plan.
63.1206(c)(2)(v)(A)............................................  Documentation of your investigation and
                                                                  evaluation of excessive exceedances during
                                                                  malfunctions.
63.1206(c)(3)(v)...............................................  Corrective measures for any automatic waste
                                                                  feed cutoff that results in an exceedance of
                                                                  an emission standard or operating parameter
                                                                  limit.
63.1206(c)(3)(vii).............................................  Documentation and results of the automatic
                                                                  waste feed cutoff operability testing.
63.1206(c)(4)(ii)..............................................  Emergency safety vent operating plan.
63.1206(c)(4)(iii).............................................  Corrective measures for any emergency safety
                                                                  vent opening.
63.1206(c)(5)(ii)..............................................  Method used for control of combustion system
                                                                  leaks.
63.1206(c)(6)..................................................  Operator training and certification program.
63.1206(c)(7)(i)(D)............................................  Operation and maintenance plan.
63.1209(c)(2)..................................................  Feedstream analysis plan.

[[Page 59555]]

 
63.1209(k)(6)(iii), 63.1209(k)(7)(ii), 63.1209(k)(9)(ii),        Documentation that a substitute activated
 63.1209(o)(4)(iii).                                              carbon, dioxin/furan formation reaction
                                                                  inhibitor, or dry scrubber sorbent will
                                                                  provide the same level of control as the
                                                                  original material.
63.1209(k)(7)(i)(C)............................................  Results of carbon bed performance monitoring.
63.1209(q).....................................................  Documentation of changes in modes of operation.
63.1211(c).....................................................  Documentation of compliance.
----------------------------------------------------------------------------------------------------------------

    (c) * * *
    (1) By the compliance date, you must develop and include in the 
operating record a Documentation of Compliance. You are not subject to 
this requirement, however, if you submit a Notification of Compliance 
under Sec.  63.1207(j) prior to the compliance date. Upon inclusion of 
the Documentation of Compliance in the operating record, hazardous 
waste burning incinerators, cement kilns, and lightweight aggregate 
kilns regulated under the interim standards of Sec. Sec.  63.1203, 
63.1204, and 63.1205 are no longer subject to compliance with the 
previously applicable Notification of Compliance.
* * * * *

0
14. Section 63.1212 is added to subpart EEE to read as follows:


Sec.  63.1212  What are the other requirements pertaining to the NIC?

    (a) Certification of intent to comply. The Notice of Intent to 
Comply (NIC) must contain the following certification signed and dated 
by a responsible official as defined under Sec.  63.2 of this chapter: 
I certify under penalty of law that I have personally examined and am 
familiar with the information submitted in this document and all 
attachments and that, based on my inquiry of those individuals 
immediately responsible for obtaining the information, I believe that 
the information is true, accurate, and complete. I am aware that there 
are significant penalties for submitting false information, including 
the possibility of fine and imprisonment.
    (b) New units. Any source that files a RCRA permit application or 
permit modification request for construction of a hazardous waste 
combustion unit after October 12, 2005 must:
    (1) Prepare a draft NIC according to Sec.  63.1210(b) and make it 
available to the public upon issuance of the notice of NIC public 
meeting per Sec.  63.1210(c)(3);
    (2) Prepare a draft comprehensive performance test plan pursuant to 
the requirements of Sec.  63.1207 and make it available for public 
review upon issuance of the notice of NIC public meeting;
    (3) Provide notice to the public of a pre-application meeting 
pursuant to Sec.  124.30 or notice to the public of a permit 
modification request pursuant to Sec.  270.42 and;
    (4) Hold an informal public meeting 30 days following notice of NIC 
public meeting and notice of the pre-application meeting or notice of 
the permit modification request.
    (c) Information Repository specific to new combustion units. (1) 
Any source that files a RCRA permit application or modification request 
for construction of a new hazardous waste combustion unit after October 
12, 2005 may be required to establish an information repository if 
deemed appropriate.
    (2) The Administrator may assess the need, on a case-by-case basis 
for an information repository. When assessing the need for a 
repository, the Administrator shall consider the level of public 
interest, the presence of an existing repository, and any information 
available via the New Source Review and Title V permit processes. If 
the Administrator determines a need for a repository, then the 
Administrator shall notify the facility that it must establish and 
maintain an information repository.
    (3) The information repository shall contain all documents, 
reports, data, and information deemed necessary by the Administrator. 
The Administrator shall have the discretion to limit the contents of 
the repository.
    (4) The information repository shall be located and maintained at a 
site chosen by the source. If the Administrator finds the site 
unsuitable for the purposes and persons for which it was established, 
due to problems with location, hours of availability, access, or other 
relevant considerations, then the Administrator shall specify a more 
appropriate site.
    (5) The Administrator shall require the source to provide a written 
notice about the information repository to all individuals on the 
source mailing list.
    (6) The source shall be responsible for maintaining and updating 
the repository with appropriate information throughout a period 
specified by the Administrator. The Administrator may close the 
repository at his or her discretion based on the considerations in 
paragraph (c)(2) of this section.

0
15. Section 63.1214 is amended by revising paragraphs (c)(1), (c)(2), 
(c)(3), and (c)(4) to read as follows:


Sec.  63.1214  Implementation and enforcement.

* * * * *
    (c) * * *
    (1) Approval of alternatives to requirements in Sec. Sec.  63.1200, 
63.1203, 63.1204, 63.1205, 63.1206(a), 63.1215, 63.1216, 63.1217, 
63.1218, 63.1219, 63.1220, and 63.1221.
    (2) Approval of major alternatives to test methods under Sec. Sec.  
63.7(e)(2)(ii) and (f), 63.1208(b), and 63.1209(a)(1), as defined under 
Sec.  63.90, and as required in this subpart.
    (3) Approval of major alternatives to monitoring under Sec. Sec.  
63.8(f) and 63.1209(a)(5), as defined under Sec.  63.90, and as 
required in this subpart.
    (4) Approval of major alternatives to recordkeeping and reporting 
under Sec. Sec.  63.10(f) and 63.1211(a) through (c), as defined under 
Sec.  63.90, and as required in this subpart.

0
16. Section Sec.  63.1215 is added to subpart EEE to read as follows:


Sec.  63.1215  What are the health-based compliance alternatives for 
total chlorine?

    (a) General. (1) Overview. You may establish and comply with 
health-based compliance alternatives for total chlorine under the 
procedures prescribed in this section for your hazardous waste 
combustors other than hydrochloric acid production furnaces. You may 
comply with these health-based compliance alternatives in lieu of the 
emission standards for total chlorine provided under Sec. Sec.  
63.1216, 63.1217, 63.1219, 63.1220, and 63.1221. To identify and comply 
with the limits, you must:
    (i) Identify a total chlorine emission concentration (ppmv) 
expressed as chloride (Cl<SUP>(-)</SUP>) equivalent for each on-site 
hazardous waste combustor. You may select total chlorine emission 
concentrations as you choose to demonstrate eligibility for the risk-
based limits under this section, except as provided by paragraph (b)(4) 
of this section;
    (ii) Apportion the total chlorine emission concentration between 
HCl and Cl<INF>2</INF> according to paragraph (b)(6)(i) of this 
section, and calculate HCl and Cl<INF>2</INF> emission rates (lb/hr) 
using the gas flowrate and other parameters from the most recent 
regulatory compliance test.

[[Page 59556]]

    (iii) Calculate the annual average HCl-equivalent emission rate as 
prescribed in paragraph (b)(2) of this section.
    (iv) Perform an eligibility demonstration to determine if your HCl-
equivalent emission rate meets the national exposure standard and thus 
is below the annual average HCl-equivalent emission rate limit, as 
prescribed by paragraph (c) of this section;
    (v) Submit your eligibility demonstration for review and approval, 
as prescribed by paragraph (e) of this section, which must include 
information to ensure that the 1-hour average HCl-equivalent emission 
rate limit is not exceeded, as prescribed by paragraph (d) of this 
section;
    (vi) Demonstrate compliance with the annual average HCl-equivalent 
emission rate limit during the comprehensive performance test, as 
prescribed by the testing and monitoring requirements under paragraph 
(e) of this section;
    (vii) Comply with compliance monitoring requirements, including 
establishing feedrate limits on total chlorine and chloride, and 
operating parameter limits on emission control equipment, as prescribed 
by paragraph (f) of this section; and
    (viii) Comply with the requirements for changes, as prescribed by 
paragraph (h) of this section.
    (2) Definitions. In addition to the definitions under Sec.  
63.1201, the following definitions apply to this section:
    1-Hour Average HCl-Equivalent Emission Rate means the HCl-
equivalent emission rate (lb/hr) determined by equating the toxicity of 
chlorine to HCl using 1-hour RELs as the health risk metric for acute 
exposure.
    1-Hour Average HCl-Equivalent Emission Rate Limit means the HCl-
equivalent emission rate (lb/hr) determined by equating the toxicity of 
chlorine to HCl using 1-hour RELs as the health risk metric for acute 
exposure and which ensures that maximum 1-hour average ambient 
concentrations of HCl-equivalents do not exceed a Hazard Index of 1.0, 
rounded to the nearest tenths decimal place (0.1), at an off-site 
receptor location.
    Acute Reference Exposure Level (aREL) means health thresholds below 
which there would be no adverse health effects for greater than once in 
a lifetime exposures of one hour. ARELs are developed by the California 
Office of Health Hazard Assessment and are available at http://www.oehha.ca.gov/air/acute_rels/acuterel.html.
    Annual Average HCl-Equivalent Emission Rate means the HCl-
equivalent emission rate (lb/hr) determined by equating the toxicity of 
chlorine to HCl using RfCs as the health risk metric for long-term 
exposure.
    Annual Average HCl-Equivalent Emission Rate Limit means the HCl-
equivalent emission rate (lb/hr) determined by equating the toxicity of 
chlorine to HCl using RfCs as the health risk metric for long-term 
exposure and which ensures that maximum annual average ambient 
concentrations of HCl equivalents do not exceed a Hazard Index of 1.0, 
rounded to the nearest tenths decimal place (0.1), at an off-site 
receptor location.
    Hazard Index (HI) means the sum of more than one Hazard Quotient 
for multiple substances and/or multiple exposure pathways. In this 
section, the Hazard Index is the sum of the Hazard Quotients for HCl 
and chlorine.
    Hazard Quotient (HQ) means the ratio of the predicted media 
concentration of a pollutant to the media concentration at which no 
adverse effects are expected. For chronic inhalation exposures, the HQ 
is calculated under this section as the air concentration divided by 
the RfC. For acute inhalation exposures, the HQ is calculated under 
this section as the air concentration divided by the aREL.
    Look-up table analysis means a risk screening analysis based on 
comparing the HCl-equivalent emission rate from the affected source to 
the appropriate HCl-equivalent emission rate limit specified in Tables 
1 through 4 of this section.
    Reference Concentration (RfC) means an estimate (with uncertainty 
spanning perhaps an order of magnitude) of a continuous inhalation 
exposure to the human population (including sensitive subgroups) that 
is likely to be without an appreciable risk of deleterious effects 
during a lifetime. It can be derived from various types of human or 
animal data, with uncertainty factors generally applied to reflect 
limitations of the data used.
    (b) HCl-equivalent emission rates. (1) You must express total 
chlorine emission rates for each hazardous waste combustor as HCl-
equivalent emission rates.
    (2) Annual average rates. You must calculate annual average 
toxicity-weighted HCl-equivalent emission rates for each combustor as 
follows:

ER<INF>tw</INF> = ER<INF>HCl</INF> + ER<INF>Cl2</INF> x 
(RfC<INF>HCl</INF>/RfC<INF>Cl2</INF>)
Where:

ER<INF>LTtw</INF> is the annual average HCl toxicity-weighted emission 
rate (HCl-equivalent emission rate) considering long-term exposures, 
lb/hr
ER<INF>HCl</INF> is the emission rate of HCl in lbs/hr
ER<INF>Cl2</INF> is the emission rate of chlorine in lbs/hr
RfC<INF>HCl</INF> is the reference concentration of HCl
RfC<INF>Cl2</INF> is the reference concentration of chlorine
    (3) 1-hour average rates. You must calculate 1-hour average 
toxicity-weighted HCl-equivalent emission rates for each combustor as 
follows:

ER<INF>STtw</INF> = ER<INF>HCl</INF> + ER<INF>Cl2</INF> x 
(aREL<INF>HCl</INF>/aREL<INF>Cl2</INF>)

Where:

ER<INF>STtw</INF> is the 1-hour average HCl toxicity-weighted emission 
rate (HCl-equivalent emission rate) considering 1-hour (short-term) 
exposures, lb/hr
ER<INF>HCl</INF> is the emission rate of HCl in lbs/hr
ER<INF>Cl2</INF> is the emission rate of chlorine in lbs/hr
aREL<INF>HCl</INF> is the 1-hour Reference Exposure Level of HCl
aREL<INF>Cl2</INF> is the 1-hour Reference Exposure Level of chlorine
    (4) You must use the RfC values for hydrogen chloride and chlorine 
found at http://epa.gov/ttn/atw/toxsource/ summary.html.
    (5) You must use the aREL values for hydrogen chloride and chlorine 
found at http://www.oehha.ca.gov/air/ acute--rels/acuterel.html.
    (6) Cl<INF>2</INF>HCl ratios--(i) Ratio for calculating annual 
average HCl-equivalent emission rates. (A) To calculate the annual 
average HCl-equivalent emission rate (lb/hr) for each combustor, you 
must apportion the total chlorine emission concentration (ppmv chloride 
(Cl<SUP>(-)</SUP>) equivalent) between HCl and chlorine according to 
the historical average Cl<INF>2</INF>/HCl volumetric ratio for all 
regulatory compliance tests.
    (B) You must calculate HCl and Cl<INF>2</INF> emission rates (lb/
hr) using the apportioned emission concentrations and the gas flowrate 
and other parameters from the most recent regulatory compliance test.
    (C) You must calculate the annual average HCl-equivalent emission 
rate using these HCl and Cl<INF>2</INF> emission rates and the equation 
in paragraph (b)(2) of this section.
    (ii) Ratio for calculating 1-hour average HCl-equivalent emission 
rates. (A) To calculate the 1-hour average HCl-equivalent emission rate 
for each combustor as a criterion for you to determine under paragraph 
(d) of this section if an hourly rolling average feedrate limit on 
total chlorine and chloride may be waived, you must apportion the total 
chlorine emission concentration (ppmv chloride (Cl<SUP>(-)</SUP>) 
equivalent) between HCl and chlorine

[[Page 59557]]

according to the historical highest Cl<INF>2</INF>/HCl volumetric ratio 
for all regulatory compliance tests.
    (B) You must calculate HCl and Cl<INF>2</INF> emission rates (lb/
hr) using the apportioned emission concentrations and the gas flowrate 
and other parameters from the most recent regulatory compliance test.
    (C) You must calculate the 1-hour average HCl-equivalent emission 
rate using the se HCl and Cl<INF>2</INF> emission rates and the 
equation in paragraph (b)(3) of this section.
    (iii) Ratios for new sources. (A) You must use engineering 
information to estimate the Cl<INF>2</INF>/HCl volumetric ratio for a 
new source for the initial eligibility demonstration.
    (B) You must use the Cl<INF>2</INF>/HCl volumetric ratio 
demonstrated during the initial comprehensive performance test to 
demonstrate in the Notification of Compliance that your HCl-equivalent 
emission rate does not exceed your HCl-equivalent emission rate limit.
    (C) When approving the test plan for the initial comprehensive 
performance test, the permitting authority will establish a periodic 
testing requirement, such as every 3 months for 1 year, to establish a 
record of representative Cl<INF>2</INF>/HCl volumetric ratios.
    (1) You must revise your HCl-equivalent emission rates and HCl-
equivalent emission rate limits after each such test using the 
procedures prescribed in paragraphs (b)(6)(i) and (ii) of this section.
    (2) If you no longer are eligible for the health-based compliance 
alternative, you must notify the permitting authority immediately and 
either:
    (i) Submit a revised eligibility demonstration requesting lower 
HCl-equivalent emission rate limits, establishing lower HCl-equivalent 
emission rates, and establishing by downward extrapolation lower 
feedrate limits for total chlorine and chloride; or
    (ii) Request a compliance schedule of up to three years to 
demonstrate compliance with the emission standards under Sec. Sec.  
63.1216, 63.1217, 63.1219, 63.1220, and 63.1221.
    (iv) Unrepresentative or inadequate historical Cl<INF>2</INF>/HCl 
volumetric ratios. (A) If you believe that the Cl<INF>2</INF>/HCl 
volumetric ratio for one or more historical regulatory compliance tests 
is not representative of the current ratio, you may request that the 
permitting authority allow you to screen those ratios from the analysis 
of historical ratios.
    (B) If the permitting authority believes that too few historical 
ratios are available to calculate a representative average ratio or 
establish a maximum ratio, the permitting authority may require you to 
conduct periodic testing to establish representative ratios.
    (v) Updating Cl<INF>2</INF>/HCl ratios. You must include the 
Cl<INF>2</INF>/HCl volumetric ratio demonstrated during each 
performance test in your data base of historical Cl2/HCl ratios to 
update the ratios you establish under paragraphs (b)(6)(i) and (ii) of 
this section for subsequent calculations of the annual average and 1-
hour average HCl-equivalent emission rates.
    (7) Emission rates are capped. The hydrogen chloride and chlorine 
emission rates you use to calculate the HCl-equivalent emission rate 
limit for incinerators, cement kilns, and lightweight aggregate kilns 
must not result in total chlorine emission concentrations exceeding:
    (i) For incinerators that were existing sources on April 19, 1996: 
77 parts per million by volume, combined emissions, expressed as 
chloride (Cl<SUP>(-)</SUP>) equivalent, dry basis and corrected to 7 
percent oxygen;
    (ii) For incinerators that are new or reconstructed sources after 
April 19, 1996: 21 parts per million by volume, combined emissions, 
expressed as chloride (Cl<SUP>(-)</SUP>) equivalent, dry basis and 
corrected to 7 percent oxygen;
    (iii) For cement kilns that were existing sources on April 19, 
1996: 130 parts per million by volume, combined emissions, expressed as 
chloride (Cl<SUP>(-)</SUP>) equivalent, dry basis and corrected to 7 
percent oxygen;
    (iv) For cement kilns that are new or reconstructed sources after 
April 19, 1996: 86 parts per million by volume, combined emissions, 
expressed as chloride (Cl<SUP>(-)</SUP>) equivalent, dry basis and 
corrected to 7 percent oxygen;
    (v) For lightweight aggregate kilns that were existing sources on 
April 19, 1996: 600 parts per million by volume, combined emissions, 
expressed as chloride (Cl<SUP>(-)</SUP>) equivalent, dry basis and 
corrected to 7 percent oxygen;
    (vi) For lightweight aggregate kilns that are new or reconstructed 
sources after April 19, 1996: 600 parts per million by volume, combined 
emissions, expressed as chloride (Cl<SUP>(-)</SUP>) equivalent, dry 
basis and corrected to 7 percent oxygen.
    (c) Eligibility demonstration--(1) General. (i) You must perform an 
eligibility demonstration to determine whether the total chlorine 
emission rates you select for each on-site hazardous waste combustor 
meet the national exposure standards using either a look-up table 
analysis prescribed by paragraph (c)(3) of this section, or a site-
specific compliance demonstration prescribed by paragraph (c)(4) of 
this section.
    (ii) You must also determine in your eligibility demonstration 
whether each combustor may exceed the 1-hour HCl-equivalent emission 
rate limit absent an hourly rolling average limit on the feedrate of 
total chlorine and chloride, as provided by paragraph (d) of this 
section.
    (2) Definition of eligibility. (i) Eligibility for the risk-based 
total chlorine standard is determined by comparing the annual average 
HCl-equivalent emission rate for the total chlorine emission rate you 
select for each combustor to the annual average HCl-equivalent emission 
rate limit.
    (ii) The annual average HCl-equivalent emission rate limit ensures 
that the Hazard Index for chronic exposure from HCl and chlorine 
emissions from all on-site hazardous waste combustors is less than or 
equal to 1.0, rounded to the nearest tenths decimal place (0.1), for 
the actual individual most exposed to the facility's emissions, 
considering off-site locations where people reside and where people 
congregate for work, school, or recreation.
    (iii) Your facility is eligible for the health-based compliance 
alternative for total chlorine if either:
    (A) The annual average HCl-equivalent emission rate for each on-
site hazardous waste combustor is below the appropriate value in the 
look-up table determined under paragraph (c)(3) of this section; or
    (B) The annual average HCl-equivalent emission rate for each on-
site hazardous waste combustor is below the annual average HCl-
equivalent emission rate limit you calculate based on a site-specific 
compliance demonstration under paragraph (c)(4) of this section.
    (3) Look-up table analysis. Look-up tables for the eligibility 
demonstration are provided as Tables 1 and 2 to this section.
    (i) Table 1 presents annual average HCl-equivalent emission rate 
limits for sources located in flat terrain. For purposes of this 
analysis, flat terrain is terrain that rises to a level not exceeding 
one half the stack height within a distance of 50 stack heights.
    (ii) Table 2 presents annual average HCl-equivalent emission rate 
limits for sources located in simple elevated terrain. For purposes of 
this analysis, simple elevated terrain is terrain that rises to a level 
exceeding one half the stack height, but that does not exceed the stack 
height, within a distance of 50 stack heights.
    (iii) To determine the annual average HCl-equivalent emission rate 
limit for a

[[Page 59558]]

source from the look-up table, you must use the stack height and stack 
diameter for your hazardous waste combustors and the distance between 
the stack and the property boundary.
    (iv) If any of these values for stack height, stack diameter, and 
distance to nearest property boundary do not match the exact values in 
the look-up table, you must use the next lowest table value.
    (v) Adjusted HCl-equivalent emission rate limit for multiple on-
site combustors. (A) If you have more than one hazardous waste 
combustor on site, the sum across all hazardous waste combustors of the 
ratio of the adjusted HCl-equivalent emission rate limit to the HCl-
equivalent emission rate limit provided by Tables 1 or 2 cannot exceed 
1.0, according to the following equation:
[GRAPHIC] [TIFF OMITTED] TR12OC05.003

Where:

i = number of on-site hazardous waste combustors;
HCl-Equivalent Emission Rate Limit Adjusted<INF>i</INF> means the 
apportioned, allowable HCl-equivalent emission rate limit for combustor 
i, and
HCl-Equivalent Emission Rate Limit Table<INF>i</INF> means the HCl-
equivalent emission rate limit from Table 1 or 2 to Sec.  63.1215 for 
combustor i.

    (B) The adjusted HCl-equivalent emission rate limit becomes the 
HCl-equivalent emission rate limit.
    (4) Site-specific compliance demonstration. (i) You may use any 
scientifically-accepted peer-reviewed risk assessment methodology for 
your site-specific compliance demonstration to calculate an annual 
average HCl-equivalent emission rate limit for each on-site hazardous 
waste combustor. An example of one approach for performing the 
demonstration for air toxics can be found in the EPA's ``Air Toxics 
Risk Assessment Reference Library, Volume 2, Site-Specific Risk 
Assessment Technical Resource Document,'' which may be obtained through 
the EPA's Air Toxics Web site at http://www.epa.gov/ttn/fera/risk_atra_main.html.
    (ii) The annual average HCl-equivalent emission rate limit is the 
HCl-equivalent emission rate that ensures that the Hazard Index 
associated with maximum annual average exposures is not greater than 
1.0 rounded to the nearest tenths decimal place (0.1).
    (iii) To determine the annual average HCl-equivalent emission rate 
limit, your site-specific compliance demonstration must, at a minimum:
    (A) Estimate long-term inhalation exposures through the estimation 
of annual or multi-year average ambient concentrations;
    (B) Estimate the inhalation exposure for the actual individual most 
exposed to the facility's emissions from hazardous waste combustors, 
considering off-site locations where people reside and where people 
congregate for work, school, or recreation;
    (C) Use site-specific, quality-assured data wherever possible;
    (D) Use health-protective default assumptions wherever site-
specific data are not available, and:
    (E) Contain adequate documentation of the data and methods used for 
the assessment so that it is transparent and can be reproduced by an 
experienced risk assessor and emissions measurement expert.
    (iv) Your site-specific compliance demonstration need not:
    (A) Assume any attenuation of exposure concentrations due to the 
penetration of outdoor pollutants into indoor exposure areas;
    (B) Assume any reaction or deposition of the emitted pollutants 
during transport from the emission point to the point of exposure.
    (d) Assurance that the 1-hour HCl-equivalent emission rate limit 
will not be exceeded. To ensure that the 1-hour HCl-equivalent emission 
rate limit will not be exceeded when complying with the annual average 
HCl-equivalent emission rate limit, you must establish a 1-hour average 
HCl-equivalent emission rate for each combustor, establish a 1-hour 
average HCl-equivalent emission rate limit for each combustor, and 
consider site-specific factors including prescribed criteria to 
determine if the 1-hour average HCl-equivalent emission rate limit may 
be exceeded absent an hourly rolling average limit on the feedrate of 
total chlorine and chloride. If the 1-hour average HCl-equivalent 
emission rate limit may be exceeded, you must establish an hourly 
rolling average feedrate limit on total chlorine as provided by 
paragraph (f)(3) of this section.
    (1) 1-hour average HCl-equivalent emission rate. You must calculate 
the 1-hour average HCl-equivalent emission rate from the total chlorine 
emission concentration you select for each source as prescribed in 
paragraph (b)(6)(ii)(C) of this section.
    (2) 1-hour average HCl-equivalent emission rate limit. You must 
establish the 1-hour average HCl-equivalent emission rate limit for 
each affected source using either a look-up table analysis or site-
specific analysis:
    (i) Look-up table analysis. Look-up tables are provided for 1-hour 
average HCl-equivalent emission rate limits as Table 3 and Table 4 to 
this section. Table 3 provides limits for facilities located in flat 
terrain. Table 4 provides limits for facilities located in simple 
elevated terrain. You must use the Tables to establish 1-hour average 
HCl-equivalent emission rate limits as prescribed in paragraphs 
(c)(3)(iii) through (c)(3)(v) of this section for annual average HCl-
equivalent emission rate limits.
    (ii) Site-specific analysis. The 1-hour average HCl-equivalent 
emission rate limit is the HCl-equivalent emission rate that ensures 
that the Hazard Index associated with maximum 1-hour average exposures 
is not greater than 1.0 rounded to the nearest tenths decimal place 
(0.1). You must follow the risk assessment procedures under paragraph 
(c)(4) of this section to estimate short-term inhalation exposures 
through the estimation of maximum 1-hour average ambient 
concentrations.
    (3) Criteria for determining whether the 1-hour HCl-equivalent 
emission rate may be exceeded absent an hourly rolling average limit on 
the feedrate of total chlorine and chloride. An hourly rolling average 
feedrate limit on total chlorine and chloride is waived if you 
determine considering the criteria listed below that the long-term 
feedrate limit (and averaging period) established under paragraph 
(c)(4)(i) of this section will also ensure that the 1-hour average HCl-
equivalent emission rate will not exceed the 1-hour average HCl-
equivalent emission rate limit you calculate for each combustor.
    (i) The ratio of the 1-hour average HCl-equivalent emission rate 
based on the total chlorine emission rate you select for each hazardous 
waste combustor to the 1-hour average HCl-equivalent emission rate 
limit for the combustor; and
    (ii) The potential for the source to vary total chlorine and 
chloride

[[Page 59559]]

feedrates substantially over the averaging period for the feedrate 
limit established under paragraph (c)(4)(i) of this section.
    (e) Review and approval of eligibility demonstrations--(1) Content 
of the eligibility demonstration--(i) General. The eligibility 
demonstration must include the following information, at a minimum:
    (A) Identification of each hazardous waste combustor combustion gas 
emission point (e.g., generally, the flue gas stack);
    (B) The maximum and average capacity at which each combustor will 
operate, and the maximum rated capacity for each combustor, using the 
metric of stack gas volume (under both actual and standard conditions) 
emitted per unit of time, as well as any other metric that is 
appropriate for the combustor (e.g., million Btu/hr heat input for 
boilers; tons of dry raw material feed/hour for cement kilns);
    (C) Stack parameters for each combustor, including, but not limited 
to stack height, stack diameter, stack gas temperature, and stack gas 
exit velocity;
    (D) Plot plan showing all stack emission points, nearby residences 
and property boundary line;
    (E) Identification of any stack gas control devices used to reduce 
emissions from each combustor;
    (F) Identification of the RfC values used to calculate annual 
average HCl-equivalent emission rates and the aREL values used to 
calculate 1-hour average HCl-equivalent emission rates;
    (G) Calculations used to determine the annual average and 1-hour 
average HCl-equivalent emission rates and rate limits, including 
calculation of the Cl<INF>2</INF>/HCl ratios as prescribed by paragraph 
(b)(6) of this section;
    (ii) Additional content to implement the annual average HCl-
equivalent emission rate limit. You must include the following in your 
eligibility demonstration to implement the annual average HCl-
equivalent emission rate limit:
    (A) For incinerators, cement kilns, and lightweight aggregate 
kilns, calculations to confirm that the annual average HCl-equivalent 
emission rate that you calculate from the total chlorine emission rate 
you select for each combustor does not exceed the limits provided by 
paragraph (b)(7) of this section;
    (B) Comparison of the annual average HCl-equivalent emission rate 
limit for each combustor to the annual average HCl-equivalent emission 
rate for the total chlorine emission rate you select for each 
combustor;
    (C) The annual average HCl-equivalent emission rate limit for each 
hazardous waste combustor, and the limits on operating parameters 
required under paragraph (g)(1) of this section;
    (D) Determination of the long-term chlorine feedrate limit, 
including the total chlorine system removal efficiency for sources that 
establish an (up to) annual rolling average feedrate limit under 
paragraph (g)(2)(ii) of this section;
    (iii) Additional content to implement the 1-hour average HCl-
equivalent emission rate limit. You must include the following in your 
eligibility demonstration to implement the 1-hour average HCl-
equivalent emission rate limit:
    (A) Determination of whether the combustor may exceed the 1-hour 
HCl-equivalent emission rate limit absent an hourly rolling average 
chlorine feedrate limit, including:
    (1) Determination of the 1-hour average HCl-equivalent emission 
rate from the total chlorine emission rate you select for the 
combustor;
    (2) Determination of the 1-hour average HCl-equivalent emission 
rate limit using either look-up Tables 3 and 4 to this section or site-
specific risk analysis;
    (3) Determination of the ratio of the 1-hour average HCl-equivalent 
emission rate to the 1-hour average HCl-equivalent emission rate limit 
for the combustor; and
    (4) The potential for the source to vary total chlorine and 
chloride feedrates substantially over the averaging period for the 
long-term feedrate limit established under paragraphs (g)(2)(i) and 
(g)(2)(ii) of this section; and
    (B) Determination of the hourly rolling average chlorine feedrate 
limit, including the total chlorine system removal efficiency.
    (iv) Additional content of a look-up table demonstration. If you 
use the look-up table analysis to establish HCl-equivalent emission 
rate limits, your eligibility demonstration must also contain, at a 
minimum, the following:
    (A) Documentation that the facility is located in either flat or 
simple elevated terrain; and
    (B) For facilities with more than one on-site hazardous waste 
combustor, documentation that the sum of the ratios for all such 
combustors of the HCl-equivalent emission rate to the HCl-equivalent 
emission rate limit does not exceed 1.0.
    (v) Additional content of a site-specific compliance demonstration. 
If you use a site-specific compliance demonstration, your eligibility 
demonstration must also contain, at a minimum, the following 
information to support your determination of the annual average HCl-
equivalent emission rate limit for each combustor:
    (A) Identification of the risk assessment methodology used;
    (B) Documentation of the fate and transport model used;
    (C) Documentation of the fate and transport model inputs, including 
the stack parameters listed in paragraph (d)(1)(i)(C) of this section 
converted to the dimensions required for the model;
    (D) As applicable:
    (1) Meteorological data;
    (2) Building, land use, and terrain data;
    (3) Receptor locations and population data, including areas where 
people congregate for work, school, or recreation; and
    (4) Other facility-specific parameters input into the model;
    (E) Documentation of the fate and transport model outputs; and
    (F) Documentation of any exposure assessment and risk 
characterization calculations.
    (2) Review and approval--(i) Existing sources. (A) If you operate 
an existing source, you must submit the eligibility demonstration to 
your permitting authority for review and approval not later than 12 
months prior to the compliance date. You must also submit a separate 
copy of the eligibility demonstration to: U.S. EPA, Risk and Exposure 
Assessment Group, Emission Standards Division (C404-01), Attn: Group 
Leader, Research Triangle Park, North Carolina 27711, electronic mail 
address <a href="/cdn-cgi/l/email-protection#297b6c686e694c5948074e465f"><span class="__cf_email__" data-cfemail="4d1f080c0a0d283d2c632a223b">[email protected]</span></a>.
    (B) Your permitting authority should notify you of approval or 
intent to disapprove your eligibility demonstration within 6 months 
after receipt of the original demonstration, and within 3 months after 
receipt of any supplemental information that you submit. A notice of 
intent to disapprove your eligibility demonstration, whether before or 
after the compliance date, will identify incomplete or inaccurate 
information or noncompliance with prescribed procedures and specify how 
much time you will have to submit additional information or to achieve 
the MACT standards for total chlorine under Sec. Sec.  63.1216, 
63.1217, 63.1219, 63.1220, and 63.1221. If your eligibility 
demonstration is disapproved, the permitting authority may extend the 
compliance date of the total chlorine standards to allow you to make 
changes to the design or operation of the combustor or related systems 
as quickly as practicable to enable you to achieve compliance with the 
MACT total chlorine standards.

[[Page 59560]]

    (C) If your permitting authority has not approved your eligibility 
demonstration by the compliance date, and has not issued a notice of 
intent to disapprove your demonstration, you may nonetheless begin 
complying, on the compliance date, with the HCl-equivalent emission 
rate limits you present in your eligibility demonstration.
    (D) If your permitting authority issues a notice of intent to 
disapprove your eligibility demonstration after the compliance date, 
the authority will identify the basis for that notice and specify how 
much time you will have to submit additional information or to comply 
with the MACT standards for total chlorine under Sec. Sec.  63.1216, 
63.1217, 63.1219, 63.1220, and 63.1221. The permitting authority may 
extend the compliance date of the total chlorine standards to allow you 
to make changes to the design or operation of the combustor or related 
systems as quickly as practicable to enable you to achieve compliance 
with the MACT standards for total chlorine.
    (ii) New or reconstructed sources. (A) General. The procedures for 
review and approval of eligibility demonstrations applicable to 
existing sources under paragraph (e)(2)(i) of this section also apply 
to new or reconstructed sources, except that the date you must submit 
the eligibility demonstration is as prescribed in this paragraph 
(e)(2)(ii).
    (B) If you operate a new or reconstructed source that starts up 
before April 12, 2007, or a solid fuel boiler or liquid fuel boiler 
that is an area source that increases its emissions or its potential to 
emit such that it becomes a major source of HAP before April 12, 2007, 
you must either:
    (1) Comply with the final total chlorine emission standards under 
Sec. Sec.  63.1216, 63.1217, 63.1219, 63.1220, and 63.1221, by October 
12, 2005, or upon startup, whichever is later, except for a standard 
that is more stringent than the standard proposed on April 20, 2004 for 
your source. If a final standard is more stringent than the proposed 
standard, you may comply with the proposed standard until October 14, 
2008, after which you must comply with the final standard; or
    (2) Submit an eligibility demonstration for review and approval 
under this section by April 12, 2006, and comply with the HCl-
equivalent emission rate limits and operating requirements you 
establish in the eligibility demonstration.
    (C) If you operate a new or reconstructed source that starts up on 
or after April 12, 2007, or a solid fuel boiler or liquid fuel boiler 
that is an area source that increases its emissions or its potential to 
emit such that it becomes a major source of HAP on or after April 12, 
2007, you must either:
    (1) Comply with the final total chlorine emission standards under 
Sec. Sec.  63.1216, 63.1217, 63.1219, 63.1220, and 63.1221 upon 
startup. If the final standard is more stringent than the standard 
proposed for your source on April 20, 2004, however, and if you start 
operations before October 14, 2008, you may comply with the proposed 
standard until October 14, 2008, after which you must comply with the 
final standard; or
    (2) Submit an eligibility demonstration for review and approval 
under this section 12 months prior to startup.
    (f) Testing requirements--(1) General. You must comply with the 
requirements for comprehensive performance testing under Sec.  63.1207.
    (2) System removal efficiency. (i) You must calculate the total 
chlorine removal efficiency of the combustor during each run of the 
comprehensive performance test.
    (ii) You must calculate the average system removal efficiency as 
the average of the test run averages.
    (iii) If your source does not control emissions of total chlorine, 
you must assume zero system removal efficiency.
    (3) Annual average HCl-equivalent emission rate limit. If emissions 
during the comprehensive performance test exceed the annual average 
HCl-equivalent emission rate limit, eligibility for emission limits 
under this section is not affected. This emission rate limit is an 
annual average limit even though compliance is based on a 12-hour or 
(up to) an annual rolling average feedrate limit on total chlorine and 
chloride because the feedrate limit is also used for compliance 
assurance for the semivolatile metal emission standard
    (4) 1-hour average HCl-equivalent emission rate limit. Total 
chlorine emissions during each run of the comprehensive performance 
test cannot exceed the 1-hour average HCl-equivalent emission rate 
limit.
    (5) Test methods. (i) If you operate a cement kiln or a combustor 
equipped with a dry acid gas scrubber, you must use EPA Method 320/321 
or ASTM D 6735-01, or an equivalent method, to measure hydrogen 
chloride, and the back-half (caustic impingers) of Method 26/26A, or an 
equivalent method, to measure chlorine gas.
    (ii) Bromine and sulfur considerations. If you operate an 
incinerator, boiler, or lightweight aggregate kiln and your feedstreams 
contain bromine or sulfur during the comprehensive performance test at 
levels specified under paragraph (e)(2)(ii)(B) of this section, you 
must use EPA Method 320/321 or ASTM D 6735-01, or an equivalent method, 
to measure hydrogen chloride, and Method 26/26A, or an equivalent 
method, to measure chlorine and hydrogen chloride, and determine your 
chlorine emissions as follows:
    (A) You must determine you chlorine emissions to be the higher of 
the value measured by Method 26/26A, or an equivalent method, or the 
value calculated by difference between the combined hydrogen chloride 
and chlorine levels measured by Method 26/26a, or an equivalent method, 
and the hydrogen chloride measurement from EPA Method 320/321 or ASTM D 
6735-01, or an equivalent method.
    (B) The procedures under paragraph (f)(2)(ii) of this section for 
determining hydrogen chloride and chlorine emissions apply if you feed 
bromine or sulfur during the performance test at the levels specified 
in this paragraph (f)(5)(ii)(B):
    (1) If the bromine/chlorine ratio in feedstreams is greater than 5 
percent by mass; or
    (2) If the sulfur/chlorine ratio in feedstreams is greater than 50 
percent by mass.
    (g) Monitoring requirements. (1) General. You must establish and 
comply with limits on the same operating parameters that apply to 
sources complying with the MACT standard for total chlorine under Sec.  
63.1209(o), except that feedrate limits on total chlorine and chloride 
must be established according to paragraphs (g)(2) and (g)(3) of this 
section:
    (2) Feedrate limit to ensure compliance with the annual average 
HCl-equivalent emission rate limit. (i) For sources subject to the 
feedrate limit for total chlorine and chloride under Sec.  
63.1209(n)(4) to ensure compliance with the semivolatile metals 
standard:
    (A) The feedrate limit (and averaging period) for total chlorine 
and chloride to ensure compliance with the annual average HCl-
equivalent emission rate limit is the same as required by Sec.  
63.1209(n)(4), except as provided by paragraph (g)(2)(i)(B) of this 
section.
    (B) The numerical value of the total chlorine and chloride feedrate 
limit (i.e., not considering the averaging period) you establish under 
Sec.  63.1209(n)(4) must not exceed the value you calculate as the 
annual average HCl-equivalent emission rate limit (lb/hr) divided by [1 
- system removal efficiency], where the system removal efficiency is 
calculated as prescribed by paragraph (f)(2) of this section.

[[Page 59561]]

    (ii) For sources exempt from the feedrate limit for total chlorine 
and chloride under Sec.  63.1209(n)(4) because they comply with Sec.  
63.1207(m)(2), the feedrate limit for total chlorine and chloride to 
ensure compliance with the annual average HCl-equivalent emission rate 
must be established as follows:
    (A) You must establish an average period for the feedrate limit 
that does not exceed an annual rolling average;
    (B) The numerical value of the total chlorine and chloride feedrate 
limit (i.e., not considering the averaging period) must not exceed the 
value you calculate as the annual average HCl-equivalent emission rate 
limit (lb/hr) divided by [1 - system removal efficiency], where the 
system removal efficiency is calculated as prescribed by paragraph 
(f)(2) of this section.
    (C) You must calculate the initial rolling average as though you 
had selected a 12-hour rolling average, as provided by paragraph 
(b)(5)(i) of this section. You must calculate rolling averages 
thereafter as the average of the available one-minute values until 
enough one-minute values are available to calculate the rolling average 
period you select. At that time and thereafter, you update the rolling 
average feedrate each hour with a 60-minute average feedrate.
    (3) Feedrate limit to ensure compliance with the 1-hour average 
HCl-equivalent emission rate limit. (i) You must establish an hourly 
rolling average feedrate limit on total chlorine and chloride to ensure 
compliance with the 1-hour average HCl-equivalent emission rate limit 
unless you determine that the hourly rolling average feedrate limit is 
waived under paragraph (d) of this section.
    (ii) You must calculate the hourly rolling average feedrate limit 
for total chlorine and chloride as the 1-hour average HCl-equivalent 
emission rate limit (lb/hr) divided by [1 - system removal efficiency], 
where the system removal efficiency is calculated as prescribed by 
paragraph (f)(2)(ii) of this section.
    (h) Changes--(1) Changes over which you have control. (i) Changes 
that would affect the HCl-equivalent emission rate limit. (A) If you 
plan to change the design, operation, or maintenance of the facility in 
a manner than would decrease the annual average or 1-hour average HCl-
equivalent emission rate limit, you must submit to the permitting 
authority prior to the change a revised eligibility demonstration 
documenting the lower emission rate limits and calculations of reduced 
total chlorine and chloride feedrate limits.
    (B) If you plan to change the design, operation, or maintenance of 
the facility in a manner than would increase the annual average or 1-
hour average HCl-equivalent emission rate limit, and you elect to 
increase your total chlorine and chloride feedrate limits. You must 
also submit to the permitting authority prior to the change a revised 
eligibility demonstration documenting the increased emission rate 
limits and calculations of the increased feedrate limits prior to the 
change.
    (ii) Changes that could affect system removal efficiency. (A) If 
you plan to change the design, operation, or maintenance of the 
combustor in a manner than could decrease the system removal 
efficiency, you are subject to the requirements of Sec.  63.1206(b)(5) 
for conducting a performance test to reestablish the combustor's system 
removal efficiency and you must submit a revised eligibility 
demonstration documenting the lower system removal efficiency and the 
reduced feedrate limits on total chlorine and chloride.
    (B) If you plan to change the design, operation, or maintenance of 
the combustor in a manner than could increase the system removal 
efficiency, and you elect to document the increased system removal 
efficiency to establish higher feedrate limits on total chlorine and 
chloride, you are subject to the requirements of Sec.  63.1206(b)(5) 
for conducting a performance test to reestablish the combustor's system 
removal efficiency. You must also submit to the permitting authority a 
revised eligibility demonstration documenting the higher system removal 
efficiency and the increased feedrate limits on total chlorine and 
chloride.
    (2) Changes over which you do not have control that may decrease 
the HCl-equivalent emission rate limits. These requirements apply if 
you use a site-specific risk assessment under paragraph (c)(4) of this 
section to demonstrate eligibility for the health-based limits.
    (i) Proactive review. You must review the documentation you use in 
your eligibility demonstration every five years from the date of the 
comprehensive performance test and submit for review and approval with 
the comprehensive performance test plan either a certification that the 
information used in your eligibility demonstration has not changed in a 
manner that would decrease the annual average or 1-hour average HCl-
equivalent emission rate limit, or a revised eligibility demonstration.
    (ii) Reactive review. If in the interim between your comprehensive 
performance tests you have reason to know of changes that would 
decrease the annual average or 1-hour average HCl-equivalent emission 
rate limit, you must submit a revised eligibility demonstration as soon 
as practicable but not more frequently than annually.
    (iii) Compliance schedule. If you determine that you cannot 
demonstrate compliance with a lower annual average HCl-equivalent 
emission rate limit during the comprehensive performance test because 
you need additional time to complete changes to the design or operation 
of the source, you may request that the permitting authority grant you 
additional time to make those changes as quickly as practicable.

BILLING CODE 6560-50-P

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0
17. Section 63.1216 and an undesignated center heading are added to 
subpart EEE to read as follows:

Emissions Standards and Operating Limits for Solid Fuel Boilers, Liquid 
Fuel Boilers, and Hydrochloric Acid Production Furnaces


Sec.  63.1216  What are the standards for solid fuel boilers that burn 
hazardous waste?

    (a) Emission limits for existing sources. You must not discharge or 
cause combustion gases to be emitted into the atmosphere that contain:
    (1) For dioxins and furans, either carbon monoxide or hydrocarbon 
emissions in excess of the limits provided by paragraph (a)(5) of this 
section;
    (2) Mercury in excess of 11 [mu]g/dscm corrected to 7 percent 
oxygen;
    (3) For cadmium and lead combined, except for an area source as 
defined under Sec.  63.2, emissions in excess of 180 [mu]g/dscm, 
corrected to 7 percent oxygen;
    (4) For arsenic, beryllium, and chromium combined, except for an 
area source as defined under Sec.  63.2, emissions in excess of 380 
[mu]g/dscm, corrected to 7 percent oxygen;
    (5) For carbon monoxide and hydrocarbons, either:
    (i) Carbon monoxide in excess of 100 parts per million by volume, 
over an hourly rolling average (monitored continuously with a 
continuous emissions monitoring system), dry basis and corrected to 7 
percent oxygen. If

[[Page 59566]]

you elect to comply with this carbon monoxide standard rather than the 
hydrocarbon standard under paragraph (a)(5)(ii) of this section, you 
must also document that, during the destruction and removal efficiency 
(DRE) test runs or their equivalent as provided by Sec.  63.1206(b)(7), 
hydrocarbons do not exceed 10 parts per million by volume during those 
runs, over an hourly rolling average (monitored continuously with a 
continuous emissions monitoring system), dry basis, corrected to 7 
percent oxygen, and reported as propane; or
    (ii) Hydrocarbons in excess of 10 parts per million by volume, over 
an hourly rolling average (monitored continuously with a continuous 
emissions monitoring system), dry basis, corrected to 7 percent oxygen, 
and reported as propane;
    (6) For hydrogen chloride and chlorine combined, except for an area 
source as defined under Sec.  63.2, emissions in excess of 440 parts 
per million by volume, expressed as a chloride (Cl<SUP>(-)</SUP>) 
equivalent, dry basis and corrected to 7 percent oxygen; and
    (7) For particulate matter, except for an area source as defined 
under Sec.  63.2 or as provided by paragraph (e) of this section, 
emissions in excess of 68 mg/dscm corrected to 7 percent oxygen.
    (b) Emission limits for new sources. You must not discharge or 
cause combustion gases to be emitted into the atmosphere that contain:
    (1) For dioxins and furans, either carbon monoxide or hydrocarbon 
emissions in excess of the limits provided by paragraph (b)(5) of this 
section;
    (2) Mercury in excess of 11 [mu]g/dscm corrected to 7 percent 
oxygen;
    (3) For cadmium and lead combined, except for an area source as 
defined under Sec.  63.2, emissions in excess of 180 [mu]g/dscm, 
corrected to 7 percent oxygen;
    (4) For arsenic, beryllium, and chromium combined, except for an 
area source as defined under Sec.  63.2, emissions in excess of 190 
[mu]g/dscm, corrected to 7 percent oxygen;
    (5) For carbon monoxide and hydrocarbons, either:
    (i) Carbon monoxide in excess of 100 parts per million by volume, 
over an hourly rolling average (monitored continuously with a 
continuous emissions monitoring system), dry basis and corrected to 7 
percent oxygen. If you elect to comply with this carbon monoxide 
standard rather than the hydrocarbon standard under paragraph 
(b)(5)(ii) of this section, you must also document that, during the 
destruction and removal efficiency (DRE) test runs or their equivalent 
as provided by Sec.  63.1206(b)(7), hydrocarbons do not exceed 10 parts 
per million by volume during those runs, over an hourly rolling average 
(monitored continuously with a continuous emissions monitoring system), 
dry basis, corrected to 7 percent oxygen, and reported as propane; or
    (ii) Hydrocarbons in excess of 10 parts per million by volume, over 
an hourly rolling average (monitored continuously with a continuous 
emissions monitoring system), dry basis, corrected to 7 percent oxygen, 
and reported as propane;
    (6) For hydrogen chloride and chlorine combined, except for an area 
source as defined under Sec.  63.2, emissions in excess of 73 parts per 
million by volume, expressed as a chloride (Cl<SUP>(-)</SUP>) 
equivalent, dry basis and corrected to 7 percent oxygen; and
    (7) For particulate matter, except for an area source as defined 
under Sec.  63.2 or as provided by paragraph (e) of this section, 
emissions in excess of 34 mg/dscm corrected to 7 percent oxygen.
    (c) Destruction and removal efficiency (DRE) standard. (1) 99.99% 
DRE. Except as provided in paragraph (c)(2) of this section, you must 
achieve a DRE of 99.99% for each principle organic hazardous 
constituent (POHC) designated under paragraph (c)(3) of this section. 
You must calculate DRE for each POHC from the following equation:

DRE = [1 - (W<INF>out</INF> / W<INF>in</INF>)] x 100%

Where:

    W<INF>in</INF> = mass feedrate of one POHC in a waste feedstream; 
and
    W<INF>out</INF> = mass emission rate of the same POHC present in 
exhaust emissions prior to release to the atmosphere.
    (2) 99.9999% DRE. If you burn the dioxin-listed hazardous wastes 
F020, F021, F022, F023, F026, or F027 (see Sec.  261.31 of this 
chapter), you must achieve a DRE of 99.9999% for each POHC that you 
designate under paragraph (c)(3) of this section. You must demonstrate 
this DRE performance on POHCs that are more difficult to incinerate 
than tetra-, penta-, and hexachlorodibenzo-p-dioxins and dibenzofurans. 
You must use the equation in paragraph (c)(1) of this section to 
calculate DRE for each POHC. In addition, you must notify the 
Administrator of your intent to incinerate hazardous wastes F020, F021, 
F022, F023, F026, or F027.
    (3) Principal organic hazardous constituents (POHCs). (i) You must 
treat the POHCs in the waste feed that you specify under paragraph 
(c)(3)(ii) of this section to the extent required by paragraphs (c)(1) 
and (c)(2) of this section.
    (ii) You must specify one or more POHCs that are representative of 
the most difficult to destroy organic compounds in your hazardous waste 
feedstream. You must base this specification on the degree of 
difficulty of incineration of the organic constituents in the hazardous 
waste and on their concentration or mass in the hazardous waste feed, 
considering the results of hazardous waste analyses or other data and 
information.
    (d) Significant figures. The emission limits provided by paragraphs 
(a) and (b) of this section are presented with two significant figures. 
Although you must perform intermediate calculations using at least 
three significant figures, you may round the resultant emission levels 
to two significant figures to document compliance.
    (e) Alternative to the particulate matter standard. (1) General. In 
lieu of complying with the particulate matter standards of this 
section, you may elect to comply with the following alternative metal 
emission control requirement:
    (2) Alternative metal emission control requirements for existing 
solid fuel boilers. (i) You must not discharge or cause combustion 
gases to be emitted into the atmosphere that contain cadmium, lead, and 
selenium in excess of 180 [mu]g/dscm, combined emissions, corrected to 
7 percent oxygen; and,
    (ii) You must not discharge or cause combustion gases to be emitted 
into the atmosphere that contain antimony, arsenic, beryllium, 
chromium, cobalt, manganese, and nickel in excess of 380 [mu]g/dscm, 
combined emissions, corrected to 7 percent oxygen.
    (3) Alternative metal emission control requirements for new solid 
fuel boilers. (i) You must not discharge or cause combustion gases to 
be emitted into the atmosphere that contain cadmium, lead, and selenium 
in excess of 180 [mu]g/dscm, combined emissions, corrected to 7 percent 
oxygen; and,
    (ii) You must not discharge or cause combustion gases to be emitted 
into the atmosphere that contain antimony, arsenic, beryllium, 
chromium, cobalt, manganese, and nickel in excess of 190 [mu]g/dscm, 
combined emissions, corrected to 7 percent oxygen.
    (4) Operating limits. Semivolatile and low volatile metal operating 
parameter limits must be established to ensure compliance with the 
alternative emission limitations described in paragraphs (e)(2) and 
(e)(3) of this section pursuant to Sec.  63.1209(n), except that 
semivolatile metal feedrate limits apply to lead, cadmium, and 
selenium, combined, and low volatile metal feedrate limits apply to 
arsenic,

[[Page 59567]]

beryllium, chromium, antimony, cobalt, manganese, and nickel, combined.
    (f) Elective standards for area sources. Area sources as defined 
under Sec.  63.2 are subject to the standards for cadmium and lead, the 
standards for arsenic, beryllium, and chromium, the standards for 
hydrogen chloride and chlorine, and the standards for particulate 
matter under this section if they elect under Sec.  266.100(b)(3) of 
this chapter to comply with those standards in lieu of the standards 
under 40 CFR 266.105, 266.106, and 266.107 to control those pollutants.

0
18. Section 63.1217 is added to read as follows:


Sec.  63.1217  What are the standards for liquid fuel boilers that burn 
hazardous waste?

    (a) Emission limits for existing sources. You must not discharge or 
cause combustion gases to be emitted into the atmosphere that contain:
    (1)(i) Dioxins and furans in excess of 0.40 ng TEQ/dscm, corrected 
to 7 percent oxygen, for liquid fuel boilers equipped with a dry air 
pollution control system; or
    (ii) Either carbon monoxide or hydrocarbon emissions in excess of 
the limits provided by paragraph (a)(5) of this section for sources not 
equipped with a dry air pollution control system;
    (iii) A source equipped with a wet air pollution control system 
followed by a dry air pollution control system is not considered to be 
a dry air pollution control system, and a source equipped with a dry 
air pollution control system followed by a wet air pollution control 
system is considered to be a dry air pollution control system for 
purposes of this emission limit;
    (2) For mercury, except as provided for in paragraph (a)(2)(iii) of 
this section:
    (i) When you burn hazardous waste with an as-fired heating value 
less than 10,000 Btu/lb, emissions in excess of 19 [mu]g/dscm, 
corrected to 7 percent oxygen, on an (not-to-exceed) annual averaging 
period;
    (ii) When you burn hazardous waste with an as-fired heating value 
10,000 Btu/lb or greater, emissions in excess of 4.2 x 10<SUP>-5</SUP> 
lbs mercury attributable to the hazardous waste per million Btu heat 
input from the hazardous waste on an (not-to-exceed) annual averaging 
period;
    (iii) The boiler operated by Diversified Scientific Services, Inc. 
with EPA identification number TND982109142, and which burns 
radioactive waste mixed with hazardous waste, must comply with the 
mercury emission standard under Sec.  63.1219(a)(2);
    (3) For cadmium and lead combined, except for an area source as 
defined under Sec.  63.2,
    (i) When you burn hazardous waste with an as-fired heating value 
less than 10,000 Btu/lb, emissions in excess of 150 [mu]g/dscm, 
corrected to 7 percent oxygen, on an (not-to-exceed) annual averaging 
period;
    (ii) When you burn hazardous waste with an as-fired heating value 
of 10,000 Btu/lb or greater, emissions in excess of 8.2 x 
10<SUP>-5</SUP> lbs combined cadmium and lead emissions attributable to 
the hazardous waste per million Btu heat input from the hazardous waste 
on an (not-to-exceed) annual averaging period;
    (4) For chromium, except for an area source as defined under Sec.  
63.2:
    (i) When you burn hazardous waste with an as-fired heating value 
less than 10,000 Btu/lb, emissions in excess of 370 [mu]g/dscm, 
corrected to 7 percent oxygen;
    (ii) When you burn hazardous waste with an as-fired heating value 
of 10,000 Btu/lb or greater, emissions in excess of 1.3 x 
10<SUP>-4</SUP> lbs chromium emissions attributable to the hazardous 
waste per million Btu heat input from the hazardous waste;
    (5) For carbon monoxide and hydrocarbons, either:
    (i) Carbon monoxide in excess of 100 parts per million by volume, 
over an hourly rolling average (monitored continuously with a 
continuous emissions monitoring system), dry basis and corrected to 7 
percent oxygen. If you elect to comply with this carbon monoxide 
standard rather than the hydrocarbon standard under paragraph 
(a)(5)(ii) of this section, you must also document that, during the 
destruction and removal efficiency (DRE) test runs or their equivalent 
as provided by Sec.  63.1206(b)(7), hydrocarbons do not exceed 10 parts 
per million by volume during those runs, over an hourly rolling average 
(monitored continuously with a continuous emissions monitoring system), 
dry basis, corrected to 7 percent oxygen, and reported as propane; or
    (ii) Hydrocarbons in excess of 10 parts per million by volume, over 
an hourly rolling average (monitored continuously with a continuous 
emissions monitoring system), dry basis, corrected to 7 percent oxygen, 
and reported as propane;
    (6) For hydrogen chloride and chlorine, except for an area source 
as defined under Sec.  63.2:
    (i) When you burn hazardous waste with an as-fired heating value 
less than 10,000 Btu/lb, emissions in excess of 31 parts per million by 
volume, combined emissions, expressed as a chloride (Cl<SUP>(-)</SUP>) 
equivalent, dry basis and corrected to 7 percent oxygen;
    (ii) When you burn hazardous waste with an as-fired heating value 
of 10,000 Btu/lb or greater, emissions in excess of 5.08 x 
10<SUP>-2</SUP> lbs combined emissions of hydrogen chloride and 
chlorine gas attributable to the hazardous waste per million Btu heat 
input from the hazardous waste;
    (7) For particulate matter, except for an area source as defined 
under Sec.  63.2 or as provided by paragraph (e) of this section, 
emissions in excess of 80 mg/dscm corrected to 7 percent oxygen.
    (b) Emission limits for new sources. You must not discharge or 
cause combustion gases to be emitted into the atmosphere that contain:
    (1)(i) Dioxins and furans in excess of 0.40 ng TEQ/dscm, corrected 
to 7 percent oxygen, for liquid fuel boilers equipped with a dry air 
pollution control system; or
    (ii) Either carbon monoxide or hydrocarbon emissions in excess of 
the limits provided by paragraph (b)(5) of this section for sources not 
equipped with a dry air pollution control system;
    (iii) A source equipped with a wet air pollution control system 
followed by a dry air pollution control system is not considered to be 
a dry air pollution control system, and a source equipped with a dry 
air pollution control system followed by a wet air pollution control 
system is considered to be a dry air pollution control system for 
purposes of this emission limit;
    (2) For mercury:
    (i) When you burn hazardous waste with an as-fired heating value 
less than 10,000 Btu/lb, emissions in excess of 6.8 [mu]g/dscm, 
corrected to 7 percent oxygen, on an (not-to-exceed) annual averaging 
period;
    (ii) When you burn hazardous waste with an as-fired heating value 
of 10,000 Btu/lb or greater, emissions in excess of 1.2 x 
10<SUP>-6</SUP> lbs mercury emissions attributable to the hazardous 
waste per million Btu heat input from the hazardous waste on an (not-
to-exceed) annual averaging period;
    (3) For cadmium and lead combined, except for an area source as 
defined under Sec.  63.2:
    (i) When you burn hazardous waste with an as-fired heating value 
less than 10,000 Btu/lb, emissions in excess of 78 [mu]g/dscm, 
corrected to 7 percent oxygen, on an (not-to-exceed) annual averaging 
period;
    (ii) When you burn hazardous waste with an as-fired heating value 
greater than or equal to 10,000 Btu/lb, emissions in excess of 6.2 x 
10<SUP>-6</SUP> lbs combined cadmium and lead emissions attributable to 
the hazardous waste per

[[Page 59568]]

million Btu heat input from the hazardous waste on an (not-to-exceed) 
annual averaging period;
    (4) For chromium, except for an area source as defined under Sec.  
63.2:
    (i) When you burn hazardous waste with an as-fired heating value 
less than 10,000 Btu/lb, emissions in excess of 12 [mu]g/dscm, 
corrected to 7 percent oxygen;
    (ii) When you burn hazardous waste with an as-fired heating value 
of 10,000 Btu/lb or greater, emissions in excess of 1.4 x 
10<SUP>-5</SUP> lbs chromium emissions attributable to the hazardous 
waste per million Btu heat input from the hazardous waste;
    (5) For carbon monoxide and hydrocarbons, either:
    (i) Carbon monoxide in excess of 100 parts per million by volume, 
over an hourly rolling average (monitored continuously with a 
continuous emissions monitoring system), dry basis and corrected to 7 
percent oxygen. If you elect to comply with this carbon monoxide 
standard rather than the hydrocarbon standard under paragraph 
(b)(5)(ii) of this section, you must also document that, during the 
destruction and removal efficiency (DRE) test runs or their equivalent 
as provided by Sec.  63.1206(b)(7), hydrocarbons do not exceed 10 parts 
per million by volume during those runs, over an hourly rolling average 
(monitored continuously with a continuous emissions monitoring system), 
dry basis, corrected to 7 percent oxygen, and reported as propane; or
    (ii) Hydrocarbons in excess of 10 parts per million by volume, over 
an hourly rolling average (monitored continuously with a continuous 
emissions monitoring system), dry basis, corrected to 7 percent oxygen, 
and reported as propane;
    (6) For hydrogen chloride and chlorine, except for an area source 
as defined under Sec.  63.2:
    (i) When you burn hazardous waste with an as-fired heating value 
less than 10,000 Btu/lb, emissions in excess of 31 parts per million by 
volume, combined emissions, expressed as a chloride (Cl<SUP>(-)</SUP>) 
equivalent, dry basis and corrected to 7 percent oxygen;
    (ii) When you burn hazardous waste with an as-fired heating value 
of 10,000 Btu/lb or greater, emissions in excess of 5.08 x 
10<SUP>-2</SUP> lbs combined emissions of hydrogen chloride and 
chlorine gas attributable to the hazardous waste per million Btu heat 
input from the hazardous waste;
    (7) For particulate matter, except for an area source as defined 
under Sec.  63.2 or as provided by paragraph (e) of this section, 
emissions in excess of 20 mg/dscm corrected to 7 percent oxygen.
    (c) Destruction and removal efficiency (DRE) standard. (1) 99.99% 
DRE. Except as provided in paragraph (c)(2) of this section, you must 
achieve a DRE of 99.99% for each principle organic hazardous 
constituent (POHC) designated under paragraph (c)(3) of this section. 
You must calculate DRE for each POHC from the following equation:

DRE = [1 - (W<INF>out</INF> / W<INF>in</INF>)] x 100%

Where:

W<INF>in</INF> = mass feedrate of one POHC in a waste feedstream; and
W<INF>out</INF> = mass emission rate of the same POHC present in 
exhaust emissions prior to release to the atmosphere.

    (2) 99.9999% DRE. If you burn the dioxin-listed hazardous wastes 
F020, F021, F022, F023, F026, or F027 (see Sec.  261.31 of this 
chapter), you must achieve a DRE of 99.9999% for each POHC that you 
designate under paragraph (c)(3) of this section. You must demonstrate 
this DRE performance on POHCs that are more difficult to incinerate 
than tetra-, penta-, and hexachlorodibenzo-p-dioxins and dibenzofurans. 
You must use the equation in paragraph (c)(1) of this section to 
calculate DRE for each POHC. In addition, you must notify the 
Administrator of your intent to incinerate hazardous wastes F020, F021, 
F022, F023, F026, or F027.
    (3) Principal organic hazardous constituents (POHCs). (i) You must 
treat the POHCs in the waste feed that you specify under paragraph 
(c)(3)(ii) of this section to the extent required by paragraphs (c)(1) 
and (c)(2) of this section.
    (ii) You must specify one or more POHCs that are representative of 
the most difficult to destroy organic compounds in your hazardous waste 
feedstream. You must base this specification on the degree of 
difficulty of incineration of the organic constituents in the hazardous 
waste and on their concentration or mass in the hazardous waste feed, 
considering the results of hazardous waste analyses or other data and 
information.
    (d) Significant figures. The emission limits provided by paragraphs 
(a) and (b) of this section are presented with two significant figures. 
Although you must perform intermediate calculations using at least 
three significant figures, you may round the resultant emission levels 
to two significant figures to document compliance.
    (e) Alternative to the particulate matter standard. (1) General. In 
lieu of complying with the particulate matter standards of this 
section, you may elect to comply with the following alternative metal 
emission control requirement:
    (2) Alternative metal emission control requirements for existing 
liquid fuel boilers. (i) When you burn hazardous waste with a heating 
value less than 10,000 Btu/lb:
    (A) You must not discharge or cause combustion gases to be emitted 
into the atmosphere that contain cadmium, lead, and selenium, combined, 
in excess of 150 [mu]g/dscm, corrected to 7 percent oxygen; and
    (B) You must not discharge or cause combustion gases to be emitted 
into the atmosphere that contain antimony, arsenic, beryllium, 
chromium, cobalt, manganese, and nickel, combined, in excess of 370 
[mu]g/dscm, corrected to 7 percent oxygen;
    (ii) When you burn hazardous waste with a heating value of 10,000 
Btu/lb or greater:
    (A) You must not discharge or cause combustion gases to be emitted 
into the atmosphere that contain in excess of 8.2 x 10<SUP>-5</SUP> lbs 
combined emissions of cadmium, lead, and selenium attributable to the 
hazardous waste per million Btu heat input from the hazardous waste; 
and
    (B) You must not discharge or cause combustion gases to be emitted 
into the atmosphere that contain either in excess of 1.3 x 
10<SUP>-4</SUP> lbs combined emissions of antimony, arsenic, beryllium, 
chromium, cobalt, manganese, and nickel attributable to the hazardous 
waste per million Btu heat input from the hazardous waste;
    (3) Alternative metal emission control requirements for new liquid 
fuel boilers. (i) When you burn hazardous waste with a heating value 
less than 10,000 Btu/lb:
    (A) You must not discharge or cause combustion gases to be emitted 
into the atmosphere that contain cadmium, lead, and selenium, combined, 
in excess of 78 [mu]g/dscm, corrected to 7 percent oxygen; and
    (B) You must not discharge or cause combustion gases to be emitted 
into the atmosphere that contain antimony, arsenic, beryllium, 
chromium, cobalt, manganese, and nickel, combined, in excess of 12 
[mu]g/dscm, corrected to 7 percent oxygen;
    (ii) When you burn hazardous waste with a heating value greater 
than or equal to 10,000 Btu/lb:
    (A) You must not discharge or cause combustion gases to be emitted 
into the atmosphere that contain in excess of 6.2 x 10<SUP>-6</SUP> lbs 
combined emissions of cadmium, lead, and selenium attributable to the 
hazardous waste per million Btu heat input from the hazardous waste; 
and
    (B) You must not discharge or cause combustion gases to be emitted 
into the

[[Page 59569]]

atmosphere that contain either in excess of 1.4 x 10<SUP>-5</SUP> lbs 
combined emissions of antimony, arsenic, beryllium, chromium, cobalt, 
manganese, and nickel attributable to the hazardous waste per million 
Btu heat input from the hazardous waste;
    (4) Operating limits. Semivolatile and low volatile metal operating 
parameter limits must be established to ensure compliance with the 
alternative emission limitations described in paragraphs (e)(2) and 
(e)(3) of this section pursuant to Sec.  63.1209(n), except that 
semivolatile metal feedrate limits apply to lead, cadmium, and 
selenium, combined, and low volatile metal feedrate limits apply to 
arsenic, beryllium, chromium, antimony, cobalt, manganese, and nickel, 
combined.
    (f) Elective standards for area sources. Area sources as defined 
under Sec.  63.2 are subject to the standards for cadmium and lead, the 
standards for chromium, the standards for hydrogen chloride and 
chlorine, and the standards for particulate matter under this section 
if they elect under Sec.  266.100(b)(3) of this chapter to comply with 
those standards in lieu of the standards under 40 CFR 266.105, 266.106, 
and 266.107 to control those pollutants.

0
19. Section 63.1218 is added to read as follows:


Sec.  63.1218  What are the standards for hydrochloric acid production 
furnaces that burn hazardous waste?

    (a) Emission limits for existing sources. You must not discharge or 
cause combustion gases to be emitted into the atmosphere that contain:
    (1) For dioxins and furans, either carbon monoxide or hydrocarbon 
emissions in excess of the limits provided by paragraph (a)(5) of this 
section;
    (2) For mercury, hydrogen chloride and chlorine gas emissions in 
excess of the levels provided by paragraph (a)(6) of this section;
    (3) For lead and cadmium, except for an area source as defined 
under Sec.  63.2, hydrogen chloride and chlorine gas emissions in 
excess of the levels provided by paragraph (a)(6) of this section;
    (4) For arsenic, beryllium, and chromium, except for an area source 
as defined under Sec.  63.2, hydrogen chloride and chlorine gas 
emissions in excess of the levels provided by paragraph (a)(6) of this 
section;
    (5) For carbon monoxide and hydrocarbons, either:
    (i) Carbon monoxide in excess of 100 parts per million by volume, 
over an hourly rolling average (monitored continuously with a 
continuous emissions monitoring system), dry basis and corrected to 7 
percent oxygen. If you elect to comply with this carbon monoxide 
standard rather than the hydrocarbon standard under paragraph 
(a)(5)(ii) of this section, you must also document that, during the 
destruction and removal efficiency (DRE) test runs or their equivalent 
as provided by Sec.  63.1206(b)(7), hydrocarbons do not exceed 10 parts 
per million by volume during those runs, over an hourly rolling average 
(monitored continuously with a continuous emissions monitoring system), 
dry basis, corrected to 7 percent oxygen, and reported as propane; or
    (ii) Hydrocarbons in excess of 10 parts per million by volume, over 
an hourly rolling average (monitored continuously with a continuous 
emissions monitoring system), dry basis, corrected to 7 percent oxygen, 
and reported as propane;
    (6) For hydrogen chloride and chlorine gas, either:
    (i) Emission in excess of 150 parts per million by volume, combined 
emissions, expressed as a chloride (Cl<SUP>(-)</SUP> equivalent, dry 
basis and corrected to 7 percent oxygen; or
    (ii) Emissions greater than the levels that would be emitted if the 
source is achieving a system removal efficiency (SRE) of less than 
99.923 percent for total chlorine and chloride fed to the combustor. 
You must calculate SRE from the following equation:

SRE = [1 - (Cl <INF>out</INF> / Cl <INF>in</INF>)] x 100%

Where:

Cl in = mass feedrate of total chlorine or chloride in all feedstreams, 
reported as chloride; and
Cl out = mass emission rate of hydrogen chloride and chlorine gas, 
reported as chloride, in exhaust emissions prior to release to the 
atmosphere.

    (7) For particulate matter, except for an area source as defined 
under Sec.  63.2, hydrogen chloride and chlorine gas emissions in 
excess of the levels provided by paragraph (a)(6) of this section.
    (b) Emission limits for new sources. You must not discharge or 
cause combustion gases to be emitted into the atmosphere that contain:
    (1) For dioxins and furans, either carbon monoxide or hydrocarbon 
emissions in excess of the limits provided by paragraph (b)(5) of this 
section;
    (2) For mercury, hydrogen chloride and chlorine gas emissions in 
excess of the levels provided by paragraph (b)(6) of this section;
    (3) For lead and cadmium, except for an area source as defined 
under Sec.  63.2, hydrogen chloride and chlorine gas emissions in 
excess of the levels provided by paragraph (b)(6) of this section;
    (4) For arsenic, beryllium, and chromium, except for an area source 
as defined under Sec.  63.2, hydrogen chloride and chlorine gas 
emissions in excess of the levels provided by paragraph (b)(6) of this 
section;
    (5) For carbon monoxide and hydrocarbons, either:
    (i) Carbon monoxide in excess of 100 parts per million by volume, 
over an hourly rolling average (monitored continuously with a 
continuous emissions monitoring system), dry basis and corrected to 7 
percent oxygen. If you elect to comply with this carbon monoxide 
standard rather than the hydrocarbon standard under paragraph 
(b)(5)(ii) of this section, you must also document that, during the 
destruction and removal efficiency (DRE) test runs or their equivalent 
as provided by Sec.  63.1206(b)(7), hydrocarbons do not exceed 10 parts 
per million by volume during those runs, over an hourly rolling average 
(monitored continuously with a continuous emissions monitoring system), 
dry basis, corrected to 7 percent oxygen, and reported as propane; or
    (ii) Hydrocarbons in excess of 10 parts per million by volume, over 
an hourly rolling average (monitored continuously with a continuous 
emissions monitoring system), dry basis, corrected to 7 percent oxygen, 
and reported as propane;
    (6) For hydrogen chloride and chlorine gas, either:
    (i) Emission in excess of 25 parts per million by volume, combined 
emissions, expressed as a chloride (Cl<SUP>(-)</SUP> equivalent, dry 
basis and corrected to 7 percent oxygen; or
    (ii) Emissions greater than the levels that would be emitted if the 
source is achieving a system removal efficiency (SRE) of less than 
99.987 percent for total chlorine and chloride fed to the combustor. 
You must calculate SRE from the following equation:

SRE = [1 - (Cl <INF>out</INF> / Cl <INF>in</INF>)] x 100%

Where:

Cl in = mass feedrate of total chlorine or chloride in all feedstreams, 
reported as chloride; and
Cl out = mass emission rate of hydrogen chloride and chlorine gas, 
reported as chloride, in exhaust emissions prior to release to the 
atmosphere.

    (7) For particulate matter, except for an area source as defined 
under Sec.  63.2, hydrogen chloride and chlorine gas

[[Page 59570]]

emissions in excess of the levels provided by paragraph (b)(6) of this 
section.
    (c) Destruction and removal efficiency (DRE) standard. (1) 99.99% 
DRE. Except as provided in paragraph (c)(2) of this section, you must 
achieve a DRE of 99.99% for each principle organic hazardous 
constituent (POHC) designated under paragraph (c)(3) of this section. 
You must calculate DRE for each POHC from the following equation:

DRE = [1 - (W <INF>out</INF> / W <INF>in</INF>)] x 100%

Where:

Win = mass feedrate of one POHC in a waste feedstream; and
Wout = mass emission rate of the same POHC present in exhaust emissions 
prior to release to the atmosphere.
    (2) 99.9999% DRE. If you burn the dioxin-listed hazardous wastes 
F020, F021, F022, F023, F026, or F027 (see Sec.  261.31 of this 
chapter), you must achieve a DRE of 99.9999% for each POHC that you 
designate under paragraph (c)(3) of this section. You must demonstrate 
this DRE performance on POHCs that are more difficult to incinerate 
than tetra-, penta-, and hexachlorodibenzo-p-dioxins and dibenzofurans. 
You must use the equation in paragraph (c)(1) of this section to 
calculate DRE for each POHC. In addition, you must notify the 
Administrator of your intent to incinerate hazardous wastes F020, F021, 
F022, F023, F026, or F027.
    (3) Principal organic hazardous constituents (POHCs). (i) You must 
treat the POHCs in the waste feed that you specify under paragraph 
(c)(3)(ii) of this section to the extent required by paragraphs (c)(1) 
and (c)(2) of this section.
    (ii) You must specify one or more POHCs that are representative of 
the most difficult to destroy organic compounds in your hazardous waste 
feedstream. You must base this specification on the degree of 
difficulty of incineration of the organic constituents in the hazardous 
waste and on their concentration or mass in the hazardous waste feed, 
considering the results of hazardous waste analyses or other data and 
information.
    (d) Significant figures. The emission limits provided by paragraphs 
(a) and (b) of this section are presented with two significant figures. 
Although you must perform intermediate calculations using at least 
three significant figures, you may round the resultant emission levels 
to two significant figures to document compliance.
    (e) Elective standards for area sources. Area sources as defined 
under Sec.  63.2 are subject to the standards for cadmium and lead, the 
standards for arsenic, beryllium, and chromium, the standards for 
hydrogen chloride and chlorine, and the standards for particulate 
matter under this section if they elect under Sec.  266.100(b)(3) of 
this chapter to comply with those standards in lieu of the standards 
under 40 CFR 266.105, 266.106, and 266.107 to control those pollutants.
0
20. Section 63.1219 and a new undesignated center heading are added to 
subpart EEE to read as follows:

Replacement Emissions Standards and Operating Limits for Incinerators, 
Cement Kilns, and Lightweight Aggregate Kilns


Sec.  63.1219  What are the replacement standards for hazardous waste 
incinerators?

    (a) Emission limits for existing sources. You must not discharge or 
cause combustion gases to be emitted into the atmosphere that contain:
    (1) For dioxins and furans:
    (i) For incinerators equipped with either a waste heat boiler or 
dry air pollution control system, either:
    (A) Emissions in excess of 0.20 ng TEQ/dscm, corrected to 7 percent 
oxygen; or
    (B) Emissions in excess of 0.40 ng TEQ/dscm, corrected to 7 percent 
oxygen, provided that the combustion gas temperature at the inlet to 
the initial particulate matter control device is 400[deg]F or lower 
based on the average of the test run average temperatures. (For 
purposes of compliance, operation of a wet particulate matter control 
device is presumed to meet the 400[deg]F or lower requirement);
    (ii) Emissions in excess of 0.40 ng TEQ/dscm, corrected to 7 
percent oxygen, for incinerators not equipped with either a waste heat 
boiler or dry air pollution control system;
    (iii) A source equipped with a wet air pollution control system 
followed by a dry air pollution control system is not considered to be 
a dry air pollution control system, and a source equipped with a dry 
air pollution control system followed by a wet air pollution control 
system is considered to be a dry air pollution control system for 
purposes of this standard;
    (2) Mercury in excess of 130 [mu]g/dscm, corrected to 7 percent 
oxygen;
    (3) Cadmium and lead in excess of 230 [mu]g/dscm, combined 
emissions, corrected to 7 percent oxygen;
    (4) Arsenic, beryllium, and chromium in excess of 92 [mu]g/dscm, 
combined emissions, corrected to 7 percent oxygen;
    (5) For carbon monoxide and hydrocarbons, either:
    (i) Carbon monoxide in excess of 100 parts per million by volume, 
over an hourly rolling average (monitored continuously with a 
continuous emissions monitoring system), dry basis and corrected to 7 
percent oxygen. If you elect to comply with this carbon monoxide 
standard rather than the hydrocarbon standard under paragraph 
(a)(5)(ii) of this section, you must also document that, during the 
destruction and removal efficiency (DRE) test runs or their equivalent 
as provided by Sec.  63.1206(b)(7), hydrocarbons do not exceed 10 parts 
per million by volume during those runs, over an hourly rolling average 
(monitored continuously with a continuous emissions monitoring system), 
dry basis, corrected to 7 percent oxygen, and reported as propane; or
    (ii) Hydrocarbons in excess of 10 parts per million by volume, over 
an hourly rolling average (monitored continuously with a continuous 
emissions monitoring system), dry basis, corrected to 7 percent oxygen, 
and reported as propane;
    (6) Hydrogen chloride and chlorine gas (total chlorine) in excess 
of 32 parts per million by volume, combined emissions, expressed as a 
chloride (Cl<SUP>(-)</SUP>) equivalent, dry basis and corrected to 7 
percent oxygen; and
    (7) Except as provided by paragraph (e) of this section, 
particulate matter in excess of 0.013 gr/dscf corrected to 7 percent 
oxygen.
    (b) Emission limits for new sources. You must not discharge or 
cause combustion gases to be emitted into the atmosphere that contain:
    (1)(i) Dioxins and furans in excess of 0.11 ng TEQ/dscm corrected 
to 7 percent oxygen for incinerators equipped with either a waste heat 
boiler or dry air pollution control system; or
    (ii) Dioxins and furans in excess of 0.20 ng TEQ/dscm corrected to 
7 percent oxygen for sources not equipped with either a waste heat 
boiler or dry air pollution control system;
    (iii) A source equipped with a wet air pollution control system 
followed by a dry air pollution control system is not considered to be 
a dry air pollution control system, and a source equipped with a dry 
air pollution control system followed by a wet air pollution control 
system is considered to be a dry air pollution control system for 
purposes of this standard;
    (2) Mercury in excess of 8.1 [mu]g/dscm, corrected to 7 percent 
oxygen;
    (3) Cadmium and lead in excess of 10 [mu]g/dscm, combined 
emissions, corrected to 7 percent oxygen;
    (4) Arsenic, beryllium, and chromium in excess of 23 [mu]g/dscm, 
combined

[[Page 59571]]

emissions, corrected to 7 percent oxygen;
    (5) For carbon monoxide and hydrocarbons, either:
    (i) Carbon monoxide in excess of 100 parts per million by volume, 
over an hourly rolling average (monitored continuously with a 
continuous emissions monitoring system), dry basis and corrected to 7 
percent oxygen. If you elect to comply with this carbon monoxide 
standard rather than the hydrocarbon standard under paragraph 
(b)(5)(ii) of this section, you must also document that, during the 
destruction and removal efficiency (DRE) test runs or their equivalent 
as provided by Sec.  63.1206(b)(7), hydrocarbons do not exceed 10 parts 
per million by volume during those runs, over an hourly rolling average 
(monitored continuously with a continuous emissions monitoring system), 
dry basis, corrected to 7 percent oxygen, and reported as propane; or
    (ii) Hydrocarbons in excess of 10 parts per million by volume, over 
an hourly rolling average (monitored continuously with a continuous 
emissions monitoring system), dry basis, corrected to 7 percent oxygen, 
and reported as propane;
    (6) Hydrogen chloride and chlorine gas in excess of 21 parts per 
million by volume, combined emissions, expressed as a chloride 
(Cl<SUP>(-)</SUP>) equivalent, dry basis and corrected to 7 percent 
oxygen; and
    (7) Except as provided by paragraph (e) of this section, 
particulate matter in excess of 0.0015 gr/dscf, corrected to 7 percent 
oxygen.
    (c) Destruction and removal efficiency (DRE) standard. (1) 99.99% 
DRE. Except as provided in paragraph (c)(2) of this section, you must 
achieve a destruction and removal efficiency (DRE) of 99.99% for each 
principle organic hazardous constituent (POHC) designated under 
paragraph (c)(3) of this section. You must calculate DRE for each POHC 
from the following equation:

DRE = [1 - (W<INF>out</INF> / W<INF>in</INF>)] x 100%

Where:

W<INF>in</INF> = mass feedrate of one POHC in a waste feedstream; and
W<INF>out</INF> = mass emission rate of the same POHC present in 
exhaust emissions prior to release to the atmosphere.

    (2) 99.9999% DRE. If you burn the dioxin-listed hazardous wastes 
F020, F021, F022, F023, F026, or F027 (see Sec.  261.31 of this 
chapter), you must achieve a DRE of 99.9999% for each POHC that you 
designate under paragraph (c)(3) of this section. You must demonstrate 
this DRE performance on POHCs that are more difficult to incinerate 
than tetra-, penta-, and hexachlorodibenzo-p-dioxins and dibenzofurans. 
You must use the equation in paragraph (c)(1) of this section to 
calculate DRE for each POHC. In addition, you must notify the 
Administrator of your intent to incinerate hazardous wastes F020, F021, 
F022, F023, F026, or F027.
    (3) Principal organic hazardous constituent (POHC). (i) You must 
treat each POHC in the waste feed that you specify under paragraph 
(c)(3)(ii) of this section to the extent required by paragraphs (c)(1) 
and (c)(2) of this section.
    (ii) You must specify one or more POHCs that are representative of 
the most difficult to destroy organic compounds in your hazardous waste 
feedstream. You must base this specification on the degree of 
difficulty of incineration of the organic constituents in the hazardous 
waste and on their concentration or mass in the hazardous waste feed, 
considering the results of hazardous waste analyses or other data and 
information.
    (d) Significant figures. The emission limits provided by paragraphs 
(a) and (b) of this section are presented with two significant figures. 
Although you must perform intermediate calculations using at least 
three significant figures, you may round the resultant emission levels 
to two significant figures to document compliance.
    (e) Alternative to the particulate matter standard. (1). General. 
In lieu of complying with the particulate matter standards of this 
section, you may elect to comply with the following alternative metal 
emission control requirement:
    (2) Alternative metal emission control requirements for existing 
incinerators. (i) You must not discharge or cause combustion gases to 
be emitted into the atmosphere that contain cadmium, lead, and selenium 
in excess of 230 [mu]g/dscm, combined emissions, corrected to 7 percent 
oxygen; and,
    (ii) You must not discharge or cause combustion gases to be emitted 
into the atmosphere that contain antimony, arsenic, beryllium, 
chromium, cobalt, manganese, and nickel in excess of 92 [mu]g/dscm, 
combined emissions, corrected to 7 percent oxygen.
    (3) Alternative metal emission control requirements for new 
incinerators. (i) You must not discharge or cause combustion gases to 
be emitted into the atmosphere that contain cadmium, lead, and selenium 
in excess of 10 [mu]g/dscm, combined emissions, corrected to 7 percent 
oxygen; and,
    (ii) You must not discharge or cause combustion gases to be emitted 
into the atmosphere that contain antimony, arsenic, beryllium, 
chromium, cobalt, manganese, and nickel in excess of 23 [mu]g/dscm, 
combined emissions, corrected to 7 percent oxygen.
    (4) Operating limits. Semivolatile and low volatile metal operating 
parameter limits must be established to ensure compliance with the 
alternative emission limitations described in paragraphs (e)(2) and 
(e)(3) of this section pursuant to Sec.  63.1209(n), except that 
semivolatile metal feedrate limits apply to lead, cadmium, and 
selenium, combined, and low volatile metal feedrate limits apply to 
arsenic, beryllium, chromium, antimony, cobalt, manganese, and nickel, 
combined.

0
21. Section 63.1220 is added to subpart EEE to read as follows:


Sec.  63.1220  What are the replacement standards for hazardous waste 
burning cement kilns?

    (a) Emission and hazardous waste feed limits for existing sources. 
You must not discharge or cause combustion gases to be emitted into the 
atmosphere or feed hazardous waste that contain:
    (1) For dioxins and furans, either:
    (i) Emissions in excess of 0.20 ng TEQ/dscm corrected to 7 percent 
oxygen; or
    (ii) Emissions in excess of 0.40 ng TEQ/dscm corrected to 7 percent 
oxygen provided that the combustion gas temperature at the inlet to the 
initial dry particulate matter control device is 400 [deg]F or lower 
based on the average of the test run average temperatures;
    (2) For mercury, both:
    (i) An average as-fired concentration of mercury in all hazardous 
waste feedstreams in excess of 3.0 parts per million by weight; and
    (ii) Emissions in excess of 120 [mu]g/dscm, corrected to 7 percent 
oxygen; or
    (iii) A hazardous waste feedrate corresponding to a maximum 
theoretical emission concentration (MTEC) in excess of 120 [mu]g/dscm;
    (3) For cadmium and lead, both:
    (i) Emissions in excess of 7.6 x 10<SUP>-4</SUP> lbs combined 
emissions of cadmium and lead attributable to the hazardous waste per 
million Btu heat input from the hazardous waste; and
    (ii) Emissions in excess of 330 [mu]g/dscm, combined emissions, 
corrected to 7 percent oxygen;
    (4) For arsenic, beryllium, and chromium, both:
    (i) Emissions in excess of 2.1 x 10<SUP>-5</SUP> lbs combined 
emissions of arsenic, beryllium, and chromium attributable to the 
hazardous waste per million Btu heat input from the hazardous waste; 
and
    (ii) Emissions in excess of 56 [mu]g/dscm, combined emissions, 
corrected to 7 percent oxygen;

[[Page 59572]]

    (5) Carbon monoxide and hydrocarbons. (i) For kilns equipped with a 
by-pass duct or midkiln gas sampling system, either:
    (A) Carbon monoxide in the by-pass duct or mid-kiln gas sampling 
system in excess of 100 parts per million by volume, over an hourly 
rolling average (monitored continuously with a continuous emissions 
monitoring system), dry basis and corrected to 7 percent oxygen. If you 
elect to comply with this carbon monoxide standard rather than the 
hydrocarbon standard under paragraph (a)(5)(i)(B) of this section, you 
must also document that, during the destruction and removal efficiency 
(DRE) test runs or their equivalent as provided by Sec.  63.1206(b)(7), 
hydrocarbons in the by-pass duct or mid-kiln gas sampling system do not 
exceed 10 parts per million by volume during those runs, over an hourly 
rolling average (monitored continuously with a continuous emissions 
monitoring system), dry basis, corrected to 7 percent oxygen, and 
reported as propane; or
    (B) Hydrocarbons in the by-pass duct or midkiln gas sampling system 
in excess of 10 parts per million by volume, over an hourly rolling 
average (monitored continuously with a continuous emissions monitoring 
system), dry basis, corrected to 7 percent oxygen, and reported as 
propane;
    (ii) For kilns not equipped with a by-pass duct or midkiln gas 
sampling system, either:
    (A) Hydrocarbons in the main stack in excess of 20 parts per 
million by volume, over an hourly rolling average (monitored 
continuously with a continuous emissions monitoring system), dry basis, 
corrected to 7 percent oxygen, and reported as propane; or
    (B) Carbon monoxide in the main stack in excess of 100 parts per 
million by volume, over an hourly rolling average (monitored 
continuously with a continuous emissions monitoring system), dry basis 
and corrected to 7 percent oxygen. If you elect to comply with this 
carbon monoxide standard rather than the hydrocarbon standard under 
paragraph (a)(5)(ii)(A) of this section, you also must document that, 
during the destruction and removal efficiency (DRE) test runs or their 
equivalent as provided by Sec.  63.1206(b)(7), hydrocarbons in the main 
stack do not exceed 20 parts per million by volume during those runs, 
over an hourly rolling average (monitored continuously with a 
continuous emissions monitoring system), dry basis, corrected to 7 
percent oxygen, and reported as propane.
    (6) Hydrogen chloride and chlorine gas in excess of 120 parts per 
million by volume, combined emissions, expressed as a chloride 
(Cl<SUP>(-)</SUP>) equivalent, dry basis, corrected to 7 percent 
oxygen; and
    (7) For particulate matter, both:
    (i) Emissions in excess of 0.028 gr/dscf corrected to 7 percent 
oxygen; and
    (ii) Opacity greater than 20 percent, unless your source is 
equipped with a bag leak detection system under Sec.  63.1206(c)(8) or 
a particulate matter detection system under Sec.  63.1206(c)(9).
    (b) Emission and hazardous waste feed limits for new sources. You 
must not discharge or cause combustion gases to be emitted into the 
atmosphere or feed hazardous waste that contain:
    (1) For dioxins and furans, either:
    (i) Emissions in excess of 0.20 ng TEQ/dscm corrected to 7 percent 
oxygen; or
    (ii) Emissions in excess of 0.40 ng TEQ/dscm corrected to 7 percent 
oxygen provided that the combustion gas temperature at the inlet to the 
initial dry particulate matter control device is 400 [deg]F or lower 
based on the average of the test run average temperatures;
    (2) For mercury, both:
    (i) An average as-fired concentration of mercury in all hazardous 
waste feedstreams in excess of 1.9 parts per million by weight; and
    (ii) Emissions in excess of 120 [mu]g/dscm, corrected to 7 percent 
oxygen; or
    (iii) A hazardous waste feedrate corresponding to a maximum 
theoretical emission concentration (MTEC) in excess of 120 [mu]g/dscm;
    (3) For cadmium and lead, both:
    (i) Emissions in excess of 6.2 x 10<SUP>-5</SUP> lbs combined 
emissions of cadmium and lead attributable to the hazardous waste per 
million Btu heat input from the hazardous waste; and
    (ii) Emissions in excess of 180 [mu]g/dscm, combined emissions, 
corrected to 7 percent oxygen;
    (4) For arsenic, beryllium, and chromium, both:
    (i) Emissions in excess of 1.5 x 10<SUP>-5</SUP> lbs combined 
emissions of arsenic, beryllium, and chromium attributable to the 
hazardous waste per million Btu heat input from the hazardous waste; 
and
    (ii) Emissions in excess of 54 [mu]g/dscm, combined emissions, 
corrected to 7 percent oxygen;
    (5) Carbon monoxide and hydrocarbons. (i) For kilns equipped with a 
by-pass duct or midkiln gas sampling system, carbon monoxide and 
hydrocarbons emissions are limited in both the bypass duct or midkiln 
gas sampling system and the main stack as follows:
    (A) Emissions in the by-pass or midkiln gas sampling system are 
limited to either:
    (1) Carbon monoxide in excess of 100 parts per million by volume, 
over an hourly rolling average (monitored continuously with a 
continuous emissions monitoring system), dry basis and corrected to 7 
percent oxygen. If you elect to comply with this carbon monoxide 
standard rather than the hydrocarbon standard under paragraph 
(b)(5)(i)(A)(2) of this section, you also must document that, during 
the destruction and removal efficiency (DRE) test runs or their 
equivalent as provided by Sec.  63.1206(b)(7), hydrocarbons do not 
exceed 10 parts per million by volume during those runs, over an hourly 
rolling average (monitored continuously with a continuous emissions 
monitoring system), dry basis, corrected to 7 percent oxygen, and 
reported as propane; or
    (2) Hydrocarbons in the by-pass duct or midkiln gas sampling system 
in excess of 10 parts per million by volume, over an hourly rolling 
average (monitored continuously with a continuous emissions monitoring 
system), dry basis, corrected to 7 percent oxygen, and reported as 
propane; and
    (B) Hydrocarbons in the main stack are limited, if construction of 
the kiln commenced after April 19, 1996 at a plant site where a cement 
kiln (whether burning hazardous waste or not) did not previously exist, 
to 50 parts per million by volume, over a 30-day block average 
(monitored continuously with a continuous monitoring system), dry 
basis, corrected to 7 percent oxygen, and reported as propane.
    (ii) For kilns not equipped with a by-pass duct or midkiln gas 
sampling system, hydrocarbons and carbon monoxide are limited in the 
main stack to either:
    (A) Hydrocarbons not exceeding 20 parts per million by volume, over 
an hourly rolling average (monitored continuously with a continuous 
emissions monitoring system), dry basis, corrected to 7 percent oxygen, 
and reported as propane; or
    (B)(1) Carbon monoxide not exceeding 100 parts per million by 
volume, over an hourly rolling average (monitored continuously with a 
continuous emissions monitoring system), dry basis, corrected to 7 
percent oxygen; and
    (2) Hydrocarbons not exceeding 20 parts per million by volume, over 
an hourly rolling average (monitored continuously with a continuous

[[Page 59573]]

monitoring system), dry basis, corrected to 7 percent oxygen, and 
reported as propane at any time during the destruction and removal 
efficiency (DRE) test runs or their equivalent as provided by Sec.  
63.1206(b)(7); and
    (3) If construction of the kiln commenced after April 19, 1996 at a 
plant site where a cement kiln (whether burning hazardous waste or not) 
did not previously exist, hydrocarbons are limited to 50 parts per 
million by volume, over a 30-day block average (monitored continuously 
with a continuous monitoring system), dry basis, corrected to 7 percent 
oxygen, and reported as propane.
    (6) Hydrogen chloride and chlorine gas in excess of 86 parts per 
million by volume, combined emissions, expressed as a chloride 
(Cl<SUP>(-)</SUP>) equivalent, dry basis and corrected to 7 percent 
oxygen; and
    (7) For particulate matter, both:
    (i) Emissions in excess of 0.0023 gr/dscf corrected to 7 percent 
oxygen; and
    (ii) Opacity greater than 20 percent, unless your source is 
equipped with a bag leak detection system under Sec.  63.1206(c)(8) or 
a particulate matter detection system under Sec.  63.1206(c)(9).
    (c) Destruction and removal efficiency (DRE) standard. (1) 99.99% 
DRE. Except as provided in paragraph (c)(2) of this section, you must 
achieve a destruction and removal efficiency (DRE) of 99.99% for each 
principle organic hazardous constituent (POHC) designated under 
paragraph (c)(3) of this section. You must calculate DRE for each POHC 
from the following equation:

DRE = [1 - (W<INF>out</INF> / W<INF>in</INF>)] x 100%

Where:

W<INF>in</INF> = mass feedrate of one POHC in a waste feedstream; and
W<INF>out</INF> = mass emission rate of the same POHC present in 
exhaust emissions prior to release to the atmosphere.

    (2) 99.9999% DRE. If you burn the dioxin-listed hazardous wastes 
F020, F021, F022, F023, F026, or F027 (see Sec.  261.31 of this 
chapter), you must achieve a DRE of 99.9999% for each POHC that you 
designate under paragraph (c)(3) of this section. You must demonstrate 
this DRE performance on POHCs that are more difficult to incinerate 
than tetra-, penta-, and hexachlorodibenzo-p-dioxins and dibenzofurans. 
You must use the equation in paragraph (c)(1) of this section to 
calculate DRE for each POHC. In addition, you must notify the 
Administrator of your intent to incinerate hazardous wastes F020, F021, 
F022, F023, F026, or F027.
    (3) Principal organic hazardous constituent (POHC). (i) You must 
treat each POHC in the waste feed that you specify under paragraph 
(c)(3)(ii) of this section to the extent required by paragraphs (c)(1) 
and (c)(2) of this section.
    (ii) You must specify one or more POHCs that are representative of 
the most difficult to destroy organic compounds in your hazardous waste 
feedstream. You must base this specification on the degree of 
difficulty of incineration of the organic constituents in the hazardous 
waste and on their concentration or mass in the hazardous waste feed, 
considering the results of hazardous waste analyses or other data and 
information.
    (d) Cement kilns with in-line kiln raw mills. (1) General. (i) You 
must conduct performance testing when the raw mill is on-line and when 
the mill is off-line to demonstrate compliance with the emission 
standards, and you must establish separate operating parameter limits 
under Sec.  63.1209 for each mode of operation, except as provided by 
paragraphs (d)(1)(iv) and (d)(1)(v) of this section.
    (ii) You must document in the operating record each time you change 
from one mode of operation to the alternate mode and begin complying 
with the operating parameter limits for that alternate mode of 
operation.
    (iii) You must calculate rolling averages for operating parameter 
limits as provided by Sec.  63.1209(q)(2).
    (iv) If your in-line kiln raw mill has dual stacks, you may assume 
that the dioxin/furan emission levels in the by-pass stack and the 
operating parameter limits determined during performance testing of the 
by-pass stack when the raw mill is off-line are the same as when the 
mill is on-line.
    (v) In lieu of conducting a performance test to demonstrate 
compliance with the dioxin/furan emission standards for the mode of 
operation when the raw mill is on-line, you may specify in the 
performance test workplan and Notification of Compliance the same 
operating parameter limits required under Sec.  63.1209(k) for the mode 
of operation when the raw mill is on-line as you establish during 
performance testing for the mode of operation when the raw mill is off-
line.
    (2) Emissions averaging. You may comply with the mercury, 
semivolatile metal, low volatile metal, and hydrogen chloride/chlorine 
gas emission standards on a time-weighted average basis under the 
following procedures:
    (i) Averaging methodology. You must calculate the time-weighted 
average emission concentration with the following equation:

C<INF>total</INF> = {C<INF>mill-off</INF> x (T<INF>mill-off</INF> / 
(T<INF>mill-off</INF> + T<INF>mill-on</INF>)){time}  + 
{C<INF>mill-on</INF> x (T<INF>mill-on</INF> / (T<INF>mill-off</INF> + 
T<INF>mill-on</INF>)){time} 

Where:

    C<INF>total</INF> = time-weighted average concentration of a 
regulated constituent considering both raw mill on time and off time;
    C<INF>mill-off</INF> = average performance test concentration of 
regulated constituent with the raw mill off-line;
C<INF>mill-on</INF> = average performance test concentration of 
regulated constituent with the raw mill on-line;
T<INF>mill-off</INF> = time when kiln gases are not routed through the 
raw mill; and
T<INF>mill-on</INF> = time when kiln gases are routed through the raw 
mill.

    (ii) Compliance. (A) If you use this emission averaging provision, 
you must document in the operating record compliance with the emission 
standards on an annual basis by using the equation provided by 
paragraph (d)(2) of this section.
    (B) Compliance is based on one-year block averages beginning on the 
day you submit the initial notification of compliance.
    (iii) Notification. (A) If you elect to document compliance with 
one or more emission standards using this emission averaging provision, 
you must notify the Administrator in the initial comprehensive 
performance test plan submitted under Sec.  63.1207(e).
    (B) You must include historical raw mill operation data in the 
performance test plan to estimate future raw mill down-time and 
document in the performance test plan that estimated emissions and 
estimated raw mill down-time will not result in an exceedance of an 
emission standard on an annual basis.
    (C) You must document in the notification of compliance submitted 
under Sec.  63.1207(j) that an emission standard will not be exceeded 
based on the documented emissions from the performance test and 
predicted raw mill down-time.
    (e) Preheater or preheater/precalciner kilns with dual stacks. (1) 
General. You must conduct performance testing on each stack to 
demonstrate compliance with the emission standards, and you must 
establish operating parameter limits under Sec.  63.1209 for each 
stack, except as provided by paragraph (d)(1)(iv) of this section for 
dioxin/furan emissions testing and operating parameter limits for the 
by-pass stack of in-line raw mills.
    (2) Emissions averaging. You may comply with the mercury, 
semivolatile metal, low volatile metal, and hydrogen

[[Page 59574]]

chloride/chlorine gas emission standards specified in this section on a 
gas flowrate-weighted average basis under the following procedures:
    (i) Averaging methodology. You must calculate the gas flowrate-
weighted average emission concentration using the following equation:

C<INF>tot</INF> = {C<INF>main</INF> x (Q<INF>main</INF> / 
(Q<INF>main</INF> + Q<INF>bypass</INF>)){time}  + {C<INF>bypass</INF> x 
(Q<INF>bypass</INF> / (Q<INF>main</INF> + Q<INF>bypass</INF>)){time} 

Where:

C<INF>tot</INF> = gas flowrate-weighted average concentration of the 
regulated constituent;
C<INF>main</INF> = average performance test concentration demonstrated 
in the main stack;
C<INF>bypass</INF> = average performance test concentration 
demonstrated in the bypass stack;
Q<INF>main</INF> = volumetric flowrate of main stack effluent gas; and
Q<INF>bypass</INF> = volumetric flowrate of bypass effluent gas.

    (ii) Compliance. (A) You must demonstrate compliance with the 
emission standard(s) using the emission concentrations determined from 
the performance tests and the equation provided by paragraph (e)(1) of 
this section; and
    (B) You must develop operating parameter limits for bypass stack 
and main stack flowrates that ensure the emission concentrations 
calculated with the equation in paragraph (e)(1) of this section do not 
exceed the emission standards on a 12-hour rolling average basis. You 
must include these flowrate limits in the Notification of Compliance.
    (iii) Notification. If you elect to document compliance under this 
emissions averaging provision, you must:
    (A) Notify the Administrator in the initial comprehensive 
performance test plan submitted under Sec.  63.1207(e). The performance 
test plan must include, at a minimum, information describing the 
flowrate limits established under paragraph (e)(2)(ii)(B) of this 
section; and
    (B) Document in the Notification of Compliance submitted under 
Sec.  63.1207(j) the demonstrated gas flowrate-weighted average 
emissions that you calculate with the equation provided by paragraph 
(e)(2) of this section.
    (f) Significant figures. The emission limits provided by paragraphs 
(a) and (b) of this section are presented with two significant figures. 
Although you must perform intermediate calculations using at least 
three significant figures, you may round the resultant emission levels 
to two significant figures to document compliance.
    (g) [Reserved].
    (h) When you comply with the particulate matter requirements of 
paragraphs (a)(7) or (b)(7) of this section, you are exempt from the 
New Source Performance Standard for particulate matter and opacity 
under Sec.  60.60 of this chapter.

0
22. Section 63.1221 is added to subpart EEE to read as follows:


Sec.  63.1221  What are the replacement standards for hazardous waste 
burning lightweight aggregate kilns?

    (a) Emission and hazardous waste feed limits for existing sources. 
You must not discharge or cause combustion gases to be emitted into the 
atmosphere or feed hazardous waste that contain:
    (1) For dioxins and furans, either:
    (i) Emissions in excess of 0.20 ng TEQ/dscm corrected to 7 percent 
oxygen; or
    (ii) Rapid quench of the combustion gas temperature at the exit of 
the (last) combustion chamber (or exit of any waste heat recovery 
system that immediately follows the last combustion chamber) to 
400[deg]F or lower based on the average of the test run average 
temperatures. You must also notify in writing the RCRA authority that 
you are complying with this option;
    (2) For mercury, either:
    (i) Emissions in excess of 120 [mu]g/dscm, corrected to 7 percent 
oxygen; or
    (ii) A hazardous waste feedrate corresponding to a maximum 
theoretical emission concentration (MTEC) in excess of 120 [mu]g/dscm;
    (3) For cadmium and lead, both:
    (i) Emissions in excess of 3.0 x 10<SUP>-4</SUP> lbs combined 
emissions of cadmium and lead attributable to the hazardous waste per 
million Btu heat input from the hazardous waste; and
    (ii) Emissions in excess of 250 [mu]g/dscm, combined emissions, 
corrected to 7 percent oxygen;
    (4) For arsenic, beryllium, and chromium, both:
    (i) In excess of 9.5 x 10<SUP>-5</SUP> lbs combined emissions of 
arsenic, beryllium, and chromium attributable to the hazardous waste 
per million Btu heat input from the hazardous waste;
    (ii) Emissions in excess of 110 [mu]g/dscm, combined emissions, 
corrected to 7 percent oxygen;
    (5) Carbon monoxide and hydrocarbons. (i) Carbon monoxide in excess 
of 100 parts per million by volume, over an hourly rolling average 
(monitored continuously with a continuous emissions monitoring system), 
dry basis and corrected to 7 percent oxygen. If you elect to comply 
with this carbon monoxide standard rather than the hydrocarbon standard 
under paragraph (a)(5)(ii) of this section, you also must document 
that, during the destruction and removal efficiency (DRE) test runs or 
their equivalent as provided by Sec.  63.1206(b)(7), hydrocarbons do 
not exceed 20 parts per million by volume during those runs, over an 
hourly rolling average (monitored continuously with a continuous 
emissions monitoring system), dry basis, corrected to 7 percent oxygen, 
and reported as propane; or
    (ii) Hydrocarbons in excess of 20 parts per million by volume, over 
an hourly rolling average, dry basis, corrected to 7 percent oxygen, 
and reported as propane;
    (6) Hydrogen chloride and chlorine gas in excess of 600 parts per 
million by volume, combined emissions, expressed as a chloride 
(Cl<SUP>(-)</SUP>) equivalent, dry basis and corrected to 7 percent 
oxygen; and
    (7) Particulate matter emissions in excess of 0.025 gr/dscf, 
corrected to 7 percent oxygen.
    (b) Emission and hazardous waste feed limits for new sources. You 
must not discharge or cause combustion gases to be emitted into the 
atmosphere or feed hazardous waste that contain:
    (1) For dioxins and furans, either:
    (i) Emissions in excess of 0.20 ng TEQ/dscm corrected to 7 percent 
oxygen; or
    (ii) Rapid quench of the combustion gas temperature at the exit of 
the (last) combustion chamber (or exit of any waste heat recovery 
system that immediately follows the last combustion chamber) to 
400[deg]F or lower based on the average of the test run average 
temperatures. You must also notify in writing the RCRA authority that 
you are complying with this option;
    (2) For mercury, either:
    (i) Emissions in excess of 120 [mu]g/dscm, corrected to 7 percent 
oxygen; or
    (ii) A hazardous waste feedrate corresponding to a maximum 
theoretical emission concentration (MTEC) in excess of 120 [mu]g/dscm;
    (3) For cadmium and lead, both:
    (i) Emissions in excess of 3.7 x 10<SUP>-5</SUP> lbs combined 
emissions of cadmium and lead attributable to the hazardous waste per 
million Btu heat input from the hazardous waste; and
    (ii) Emissions in excess of 43 [mu]g/dscm, combined emissions, 
corrected to 7 percent oxygen;
    (4) For arsenic, beryllium, and chromium, both:
    (i) In excess of 3.3 x 10<SUP>-</SUP>\5\ lbs combined emissions of 
arsenic, beryllium, and chromium attributable to the hazardous waste 
per million Btu heat input from the hazardous waste;

[[Page 59575]]

    (ii) Emissions in excess of 110 [mu]g/dscm, combined emissions, 
corrected to 7 percent oxygen;
    (5) Carbon monoxide and hydrocarbons. (i) Carbon monoxide in excess 
of 100 parts per million by volume, over an hourly rolling average 
(monitored continuously with a continuous emissions monitoring system), 
dry basis and corrected to 7 percent oxygen. If you elect to comply 
with this carbon monoxide standard rather than the hydrocarbon standard 
under paragraph (b)(5)(ii) of this section, you also must document 
that, during the destruction and removal efficiency (DRE) test runs or 
their equivalent as provided by Sec.  63.1206(b)(7), hydrocarbons do 
not exceed 20 parts per million by volume during those runs, over an 
hourly rolling average (monitored continuously with a continuous 
emissions monitoring system), dry basis, corrected to 7 percent oxygen, 
and reported as propane; or
    (ii) Hydrocarbons in excess of 20 parts per million by volume, over 
an hourly rolling average, dry basis, corrected to 7 percent oxygen, 
and reported as propane;
    (6) Hydrogen chloride and chlorine gas in excess of 600 parts per 
million by volume, combined emissions, expressed as a chloride 
(Cl<SUP>(-)</SUP>) equivalent, dry basis and corrected to 7 percent 
oxygen; and
    (7) Particulate matter emissions in excess of 0.0098 gr/dscf 
corrected to 7 percent oxygen.
    (c) Destruction and removal efficiency (DRE) standard. (1) 99.99% 
DRE. Except as provided in paragraph (c)(2) of this section, you must 
achieve a destruction and removal efficiency (DRE) of 99.99% for each 
principal organic hazardous constituent (POHC) designated under 
paragraph (c)(3) of this section. You must calculate DRE for each POHC 
from the following equation:

DRE = [1 - (W<INF>out</INF> / Win)] x 100%

Where:

    W<INF>in</INF> = mass feedrate of one POHC in a waste feedstream; 
and
    W<INF>out</INF> = mass emission rate of the same POHC present in 
exhaust emissions prior to release to the atmosphere.

    (2) 99.9999% DRE. If you burn the dioxin-listed hazardous wastes 
F020, F021, F022, F023, F026, or F027 (see Sec.  261.31 of this 
chapter), you must achieve a destruction and removal efficiency (DRE) 
of 99.9999% for each POHC that you designate under paragraph (c)(3) of 
this section. You must demonstrate this DRE performance on POHCs that 
are more difficult to incinerate than tetra-, penta-, and 
hexachlorodibenzo-dioxins and dibenzofurans. You must use the equation 
in paragraph (c)(1) of this section to calculate DRE for each POHC. In 
addition, you must notify the Administrator of your intent to burn 
hazardous wastes F020, F021, F022, F023, F026, or F027.
    (3) Principal organic hazardous constituents (POHCs). (i) You must 
treat each POHC in the waste feed that you specify under paragraph 
(c)(3)(ii) of this section to the extent required by paragraphs (c)(1) 
and (c)(2) of this section.
    (ii) You must specify one or more POHCs that are representative of 
the most difficult to destroy organic compounds in your hazardous waste 
feedstream. You must base this specification on the degree of 
difficulty of incineration of the organic constituents in the hazardous 
waste and on their concentration or mass in the hazardous waste feed, 
considering the results of hazardous waste analyses or other data and 
information.
    (d) Significant figures. The emission limits provided by paragraphs 
(a) and (b) of this section are presented with two significant figures. 
Although you must perform intermediate calculations using at least 
three significant figures, you may round the resultant emission levels 
to two significant figures to document compliance.

PART 260--HAZARDOUS WASTE MANAGEMENT SYSTEM: GENERAL

0
1. The authority citation for part 260 continues to read as follows:

    Authority: 42 U.S.C. 6905, 6912(a), 6921-6927, 6930, 6934, 6935, 
6937, 6938, 6939, and 6974.


0
2. Section 260.11 is amended by
0
a. Revising the first sentence in paragraph (a).
0
b. Revising paragraph (c)(1).
    The revisions and additions read as follows:


Sec.  260.11  References.

    (a) When used in parts 260 through 268 of this chapter, the 
following publications are incorporated by reference. * * *
* * * * *
    (c) * * *
    (1) ``APTI Course 415: Control of Gaseous Emissions,'' EPA 
Publication EPA-450/2-81-005, December 1981, IBR approved for 
Sec. Sec.  264.1035 and 265.1035.
* * * * *

PART 264--STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE 
TREATMENT, STORAGE, AND DISPOSAL FACILITIES

0
1. The authority citation for part 264 continues to read as follows:

    Authority: 42 U.S.C. 6905, 6912(a), 6924, 6925, 6927, 6928(h), 
and 6974.


0
2. Section 264.340 is amended by revising the first sentence of 
paragraph (b)(1) and adding paragraph (b)(5) to read as follows:


Sec.  264.340  Applicability.

* * * * *
    (b) * * * (1) Except as provided by paragraphs (b)(2) through 
(b)(5) of this section, the standards of this part do not apply to a 
new hazardous waste incineration unit that becomes subject to RCRA 
permit requirements after October 12, 2005; or no longer apply when an 
owner or operator of an existing hazardous waste incineration unit 
demonstrates compliance with the maximum achievable control technology 
(MACT) requirements of part 63, subpart EEE, of this chapter by 
conducting a comprehensive performance test and submitting to the 
Administrator a Notification of Compliance under Sec. Sec.  63.1207(j) 
and 63.1210(d) of this chapter documenting compliance with the 
requirements of part 63, subpart EEE, of this chapter. * * *
* * * * *
    (5) The particulate matter standard of Sec.  264.343(c) remains in 
effect for incinerators that elect to comply with the alternative to 
the particulate matter standard of Sec. Sec.  63.1206(b)(14) and 
63.1219(e) of this chapter.
* * * * *

PART 265--INTERIM STATUS STANDARDS FOR OWNERS AND OPERATORS OF 
HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES

0
1. The authority citation for part 265 continues to read as follows:

    Authority: 42 U.S.C. 6905, 6906, 6912, 6922, 6923, 6924, 6925, 
6935, 6936, and 6937.

0
2. Section 265.340 is amended by revising paragraph (b)(1) to read as 
follows:


Sec.  265.340  Applicability.

* * * * *
    (b) * * * (1) Except as provided by paragraphs (b)(2) and (b)(3) of 
this section, the standards of this part no longer apply when an owner 
or operator

[[Page 59576]]

demonstrates compliance with the maximum achievable control technology 
(MACT) requirements of part 63, subpart EEE, of this chapter by 
conducting a comprehensive performance test and submitting to the 
Administrator a Notification of Compliance under Sec. Sec.  63.1207(j) 
and 63.1210(d) of this chapter documenting compliance with the 
requirements of part 63, subpart EEE, of this chapter.
* * * * *

PART 266--STANDARDS FOR THE MANAGEMENT OF SPECIFIC HAZARDOUS WASTES 
AND SPECIFIC TYPES OF HAZARDOUS WASTE MANAGEMENT FACILITIES

0
1. The authority citation for part 266 continues to read as follows:

    Authority: 42 U.S.C. 1006, 2002(a), 3001-3009, 3014, 6905, 6906, 
6912, 6921, 6922, 6924-6927, 6934, and 6937.

0
2. Section 266.100 is amended by revising the first sentence of 
paragraph (b)(1) and adding paragraphs (b)(3) and (b)(4) to read as 
follows:


Sec.  266.100  Applicability.

* * * * *
    (b) * * * (1) Except as provided by paragraphs (b)(2), (b)(3), and 
(b)(4) of this section, the standards of this part do not apply to a 
new hazardous waste boiler or industrial furnace unit that becomes 
subject to RCRA permit requirements after October 12, 2005; or no 
longer apply when an owner or operator of an existing hazardous waste 
boiler or industrial furnace unit demonstrates compliance with the 
maximum achievable control technology (MACT) requirements of part 63, 
subpart EEE, of this chapter by conducting a comprehensive performance 
test and submitting to the Administrator a Notification of Compliance 
under Sec. Sec.  63.1207(j) and 63.1210(d) of this chapter documenting 
compliance with the requirements of part 63, subpart EEE, of this 
chapter. * * *
* * * * *
    (3) If you own or operate a boiler or hydrochloric acid production 
furnace that is an area source under Sec.  63.2 of this chapter and you 
elect not to comply with the emission standards under Sec. Sec.  
63.1216, 63.1217, and 63.1218 of this chapter for particulate matter, 
semivolatile and low volatile metals, and total chlorine, you also 
remain subject to:
    (i) Section 266.105--Standards to control particulate matter;
    (ii) Section 266.106--Standards to control metals emissions, except 
for mercury; and
    (ii) Section 266.107--Standards to control hydrogen chloride and 
chlorine gas.
    (4) The particulate matter standard of Sec.  266.105 remains in 
effect for boilers that elect to comply with the alternative to the 
particulate matter standard under Sec. Sec.  63.1216(e) and 63.1217(e) 
of this chapter.
* * * * *

PART 270--EPA ADMINISTERED PERMIT PROGRAMS: THE HAZARDOUS WASTE 
PERMIT PROGRAM

0
1. The authority citation for part 270 continues to read as follows:

    Authority: 42 U.S.C. 6905, 6912, 6924, 6925, 6927, 6939, and 
6974.

0
2. Section 270.6 is revised to read as follows:


Sec.  270.6  References.

    (a) When used in part 270 of this chapter, the following 
publications are incorporated by reference. These incorporations by 
reference were approved by the Director of the Federal Register 
pursuant to 5 U.S.C. 552(a) and 1 CFR part 51. These materials are 
incorporated as they exist on the date of approval and a notice of any 
change in these materials will be published in the Federal Register. 
Copies may be inspected at the Library, U.S. Environmental Protection 
Agency, 1200 Pennsylvania Ave., NW., (3403T), Washington, DC 20460, 
<a href="/cdn-cgi/l/email-protection#8de1e4efffecfff4e5fccde8fdeca3eae2fb"><span class="__cf_email__" data-cfemail="076b6e657566757e6f764762776629606871">[email protected]</span></a>; or at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
    (b) The following materials are available for purchase from the 
National Technical Information Service (NTIS), 5285 Port Royal Road, 
Springfield, VA 22161, (703) 605-6000 or (800) 553-6847; or for 
purchase from the Superintendent of Documents, U.S. Government Printing 
Office, Washington, DC 20402, (202) 512-1800:
    (1) ``APTI Course 415: Control of Gaseous Emissions,'' EPA 
Publication EPA-450/2-81-005, December 1981, IBR approved for 
Sec. Sec.  270.24 and 270.25.
    (2) [Reserved].

0
3. Section 270.10 is amended by adding paragraph (l) to read as 
follows:


Sec.  270.10  General application requirements.

* * * * *
    (l) If the Director concludes, based on one or more of the factors 
listed in paragraph (l)(1) of this section that compliance with the 
standards of 40 CFR part 63, subpart EEE alone may not be protective of 
human health or the environment, the Director shall require the 
additional information or assessment(s) necessary to determine whether 
additional controls are necessary to ensure protection of human health 
and the environment. This includes information necessary to evaluate 
the potential risk to human health and/or the environment resulting 
from both direct and indirect exposure pathways. The Director may also 
require a permittee or applicant to provide information necessary to 
determine whether such an assessment(s) should be required.
    (1) The Director shall base the evaluation of whether compliance 
with the standards of 40 CFR part 63, subpart EEE alone is protective 
of human health or the environment on factors relevant to the potential 
risk from a hazardous waste combustion unit, including, as appropriate, 
any of the following factors:
    (i) Particular site-specific considerations such as proximity to 
receptors (such as schools, hospitals, nursing homes, day care centers, 
parks, community activity centers, or other potentially sensitive 
receptors), unique dispersion patterns, etc.;
    (ii) Identities and quantities of emissions of persistent, 
bioaccumulative or toxic pollutants considering enforceable controls in 
place to limit those pollutants;
    (iii) Identities and quantities of nondioxin products of incomplete 
combustion most likely to be emitted and to pose significant risk based 
on known toxicities (confirmation of which should be made through 
emissions testing);
    (iv) Identities and quantities of other off-site sources of 
pollutants in proximity of the facility that significantly influence 
interpretation of a facility-specific risk assessment;
    (v) Presence of significant ecological considerations, such as the 
proximity of a particularly sensitive ecological area;
    (vi) Volume and types of wastes, for example wastes containing 
highly toxic constituents;
    (vii) Other on-site sources of hazardous air pollutants that 
significantly influence interpretation of the risk posed by the 
operation of the source in question;
    (viii) Adequacy of any previously conducted risk assessment, given 
any subsequent changes in conditions likely to affect risk; and
    (ix) Such other factors as may be appropriate.
    (2) [Reserved]

[[Page 59577]]


0
4. Section 270.19 is amended by revising paragraph (e) to reads as 
follows:


Sec.  270.19  Specific part B information requirements for 
incinerators.

* * * * *
    (e) When an owner or operator of a hazardous waste incineration 
unit becomes subject to RCRA permit requirements after October 12, 
2005, or when an owner or operator of an existing hazardous waste 
incineration unit demonstrates compliance with the air emission 
standards and limitations in part 63, subpart EEE, of this chapter 
(i.e., by conducting a comprehensive performance test and submitting a 
Notification of Compliance under Sec. Sec.  63.1207(j) and 63.1210(d) 
of this chapter documenting compliance with all applicable requirements 
of part 63, subpart EEE, of this chapter), the requirements of this 
section do not apply, except those provisions the Director determines 
are necessary to ensure compliance with Sec. Sec.  264.345(a) and 
264.345(c) of this chapter if you elect to comply with Sec.  
270.235(a)(1)(i) to minimize emissions of toxic compounds from startup, 
shutdown, and malfunction events. Nevertheless, the Director may apply 
the provisions of this section, on a case-by-case basis, for purposes 
of information collection in accordance with Sec. Sec.  270.10(k), 
270.10(l), 270.32(b)(2), and 270.32(b)(3).

0
5. Section 270.22 is amended by revising the introductory text to read 
as follows:


Sec.  270.22  Specific part B information requirements for boilers and 
industrial furnaces burning hazardous waste.

    When an owner or operator of a cement kiln, lightweight aggregate 
kiln, solid fuel boiler, liquid fuel boiler, or hydrochloric acid 
production furnace becomes subject to RCRA permit requirements after 
October 12, 2005, or when an owner or operator of an existing cement 
kiln, lightweight aggregate kiln, solid fuel boiler, liquid fuel 
boiler, or hydrochloric acid production furnace demonstrates compliance 
with the air emission standards and limitations in part 63, subpart 
EEE, of this chapter (i.e., by conducting a comprehensive performance 
test and submitting a Notification of Compliance under Sec. Sec.  
63.1207(j) and 63.1210(d) of this chapter documenting compliance with 
all applicable requirements of part 63, subpart EEE, of this chapter), 
the requirements of this section do not apply. The requirements of this 
section do apply, however, if the Director determines certain 
provisions are necessary to ensure compliance with Sec. Sec.  
266.102(e)(1) and 266.102(e)(2)(iii) of this chapter if you elect to 
comply with Sec.  270.235(a)(1)(i) to minimize emissions of toxic 
compounds from startup, shutdown, and malfunction events; or if you are 
an area source and elect to comply with the Sec. Sec.  266.105, 
266.106, and 266.107 standards and associated requirements for 
particulate matter, hydrogen chloride and chlorine gas, and non-mercury 
metals; or the Director determines certain provisions apply, on a case-
by-case basis, for purposes of information collection in accordance 
with Sec. Sec.  270.10(k), 270.10(l), 270.32(b)(2), and 270.32(b)(3).
* * * * *

0
6. Section 270.24 is amended by revising paragraph (d)(3) to read as 
follows:


Sec.  270.24  Specific part B information requirements for process 
vents.

* * * * *
    (d) * * *
    (3) A design analysis, specifications, drawings, schematics, and 
piping and instrumentation diagrams based on the appropriate sections 
of ``APTI Course 415: Control of Gaseous Emissions'' (incorporated by 
reference as specified in Sec.  270.6) or other engineering texts 
acceptable to the Regional Administrator that present basic control 
device information. The design analysis shall address the vent stream 
characteristics and control device operation parameters as specified in 
Sec.  264.1035(b)(4)(iii).
* * * * *

0
7. Section 270.25 is amended by revising paragraph (e)(3) to read as 
follows:


Sec.  270.25  Specific part B information requirements for equipment.

* * * * *
    (e) * * *
    (3) A design analysis, specifications, drawings, schematics, and 
piping and instrumentation diagrams based on the appropriate sections 
of ``APTI Course 415: Control of Gaseous Emissions'' (incorporated by 
reference as specified in Sec.  270.6) or other engineering texts 
acceptable to the Regional Administrator that present basic control 
device information. The design analysis shall address the vent stream 
characteristics and control device operation parameters as specified in 
Sec.  264.1035(b)(4)(iii).
* * * * *

0
8. Section 270.32 is amended by adding paragraph (b)(3) to read as 
follows:


Sec.  270.32  Establishing permit conditions.

* * * * *
    (b) * * *
    (3) If, as the result of an assessment(s) or other information, the 
Administrator or Director determines that conditions are necessary in 
addition to those required under 40 CFR parts 63, subpart EEE, 264 or 
266 to ensure protection of human health and the environment, he shall 
include those terms and conditions in a RCRA permit for a hazardous 
waste combustion unit.
* * * * *

0
9. Section 270.42 is amended by:
0
a. Revising paragraph (j)(1).
0
b. Redesignating paragraph (j)(2) as (j)(3).
0
c. Adding new paragraph (j)(2).
0
d. Adding new paragraph (k); and
0
e. Adding a new entry 10 in numerical order in the table under section 
L of Appendix I.
    The revisions and additions read as follows:


Sec.  270.42  Permit modification at the request of the permittee.

* * * * *
    (j) * * *
    (1) Facility owners or operators must have complied with the 
Notification of Intent to Comply (NIC) requirements of 40 CFR 63.1210 
that were in effect prior to October 11, 2000, (See 40 CFR part 63 
Sec. Sec.  63.1200-63.1499 revised as of July 1, 2000) in order to 
request a permit modification under this section for the purpose of 
technology changes needed to meet the standards under 40 CFR 63.1203, 
63.1204, and 63.1205.
    (2) Facility owners or operators must comply with the Notification 
of Intent to Comply (NIC) requirements of 40 CFR 63.1210(b) and 
63.1212(a) before a permit modification can be requested under this 
section for the purpose of technology changes needed to meet the 40 CFR 
63.1215, 63.1216, 63.1217, 63.1218, 63.1219, 63.1220, and 63.1221 
standards promulgated on October 12, 2005.
* * * * *
    (k) Waiver of RCRA permit conditions in support of transition to 
the part 63 MACT standards. (1) You may request to have specific RCRA 
operating and emissions limits waived by submitting a Class 1 permit 
modification request under Appendix I of this section, section L(10). 
You must:
    (i) Identify the specific RCRA permit operating and emissions 
limits which you are requesting to waive;
    (ii) Provide an explanation of why the changes are necessary in 
order to minimize or eliminate conflicts between the RCRA permit and 
MACT compliance; and

[[Page 59578]]

    (iii) Discuss how the revised provisions will be sufficiently 
protective.
    (iv) The Director shall approve or deny the request within 30 days 
of receipt of the request. The Director may, as his or her discretion, 
extend this 30 day deadline one time for up to 30 days by notifying the 
facility owner or operator.
    (2) To request this modification in conjunction with MACT 
performance testing where permit limits may only be waived during 
actual test events and pretesting, as defined under 40 CFR 
63.1207(h)(2)(i) and (ii), for an aggregate time not to exceed 720 
hours of operation (renewable at the discretion of the Administrator) 
you must:
    (i) Submit your modification request to the Director at the same 
time you submit your test plans to the Administrator; and
    (ii) The Director may elect to approve or deny the request 
continent upon approval of the test plans.
* * * * *

Appendix I to Sec.  270.42--Classification of Permit Modification

------------------------------------------------------------------------
                          Modifications                            Class
------------------------------------------------------------------------
 
                              * * * * * * *
L. * * *........................................................   \1\ 1
10. Changes to RCRA permit provisions needed to support
 transition to 40 CFR part 63 (Subpart EEE--National Emission
 Standards for Hazardous Air Pollutants From Hazardous Waste
 Combustors), provided the procedures of Sec.   270.42(k) are
 followed.......................................................
 
                             * * * * * * *
------------------------------------------------------------------------
\1\ Class 1 modifications requiring prior Agency approval.

* * * * *

0
10. Section 270.62 is amended by revising the introductory text to read 
as follows:


Sec.  270.62  Hazardous waste incinerator permits.

    When an owner or operator of a hazardous waste incineration unit 
becomes subject to RCRA permit requirements after October 12, 2005, or 
when an owner or operator of an existing hazardous waste incineration 
unit demonstrates compliance with the air emission standards and 
limitations in part 63, subpart EEE, of this chapter (i.e., by 
conducting a comprehensive performance test and submitting a 
Notification of Compliance under Sec. Sec.  63.1207(j) and 63.1210(d) 
of this chapter documenting compliance with all applicable requirements 
of part 63, subpart EEE, of this chapter), the requirements of this 
section do not apply, except those provisions the Director determines 
are necessary to ensure compliance with Sec. Sec.  264.345(a) and 
264.345(c) of this chapter if you elect to comply with Sec.  
270.235(a)(1)(i) to minimize emissions of toxic compounds from startup, 
shutdown, and malfunction events. Nevertheless, the Director may apply 
the provisions of this section, on a case-by-case basis, for purposes 
of information collection in accordance with Sec. Sec.  270.10(k), 
270.10(l), 270.32(b)(2), and 270.32(b)(3).
* * * * *

0
11. Section 270.66 is amended by revising the introductory text to read 
as follows:


Sec.  270.66  Permits for boilers and industrial furnaces burning 
hazardous waste.

    When an owner or operator of a cement kiln, lightweight aggregate 
kiln, solid fuel boiler, liquid fuel boiler, or hydrochloric acid 
production furnace becomes subject to RCRA permit requirements after 
October 12, 2005 or when an owner or operator of an existing cement 
kiln, lightweight aggregate kiln, solid fuel boiler, liquid fuel 
boiler, or hydrochloric acid production furnace demonstrates compliance 
with the air emission standards and limitations in part 63, subpart 
EEE, of this chapter (i.e., by conducting a comprehensive performance 
test and submitting a Notification of Compliance under Sec. Sec.  
63.1207(j) and 63.1210(d) of this chapter documenting compliance with 
all applicable requirements of part 63, subpart EEE, of this chapter), 
the requirements of this section do not apply. The requirements of this 
section do apply, however, if the Director determines certain 
provisions are necessary to ensure compliance with Sec. Sec.  
266.102(e)(1) and 266.102(e)(2)(iii) of this chapter if you elect to 
comply with Sec.  270.235(a)(1)(i) to minimize emissions of toxic 
compounds from startup, shutdown, and malfunction events; or if you are 
an area source and elect to comply with the Sec. Sec.  266.105, 
266.106, and 266.107 standards and associated requirements for 
particulate matter, hydrogen chloride and chlorine gas, and non-mercury 
metals; or the Director determines certain provisions apply, on a case-
by-case basis, for purposes of information collection in accordance 
with Sec. Sec.  270.10(k), 270.10(l), 270.32(b)(2), and 270.32(b)(3).
* * * * *

0
12. Section 270.235 is amended by:
0
a. Revising the section heading and paragraphs (a)(1) introductory text 
and (a)(2) introductory text.
0
b. Revising paragraphs (b)(1) introductory text and (b)(2).
0
c. Adding new paragraph (c).
    The revisions read as follows:
* * * * *


Sec.  270.235  Options for incinerators, cement kilns, lightweight 
aggregate kilns, solid fuel boilers, liquid fuel boilers and 
hydrochloric acid production furnaces to minimize emissions from 
startup, shutdown, and malfunction events.

    (a) * * * (1) Revisions to permit conditions after documenting 
compliance with MACT. The owner or operator of a RCRA-permitted 
incinerator, cement kiln, lightweight aggregate kiln, solid fuel 
boiler, liquid fuel boiler, or hydrochloric acid production furnace may 
request that the Director address permit conditions that minimize 
emissions from startup, shutdown, and malfunction events under any of 
the following options when requesting removal of permit conditions that 
are no longer applicable according to Sec. Sec.  264.340(b) and 
266.100(b) of this chapter:
* * * * *
    (2) Addressing permit conditions upon permit reissuance. The owner 
or operator of an incinerator, cement kiln, lightweight aggregate kiln, 
solid fuel boiler, liquid fuel boiler, or hydrochloric acid production 
furnace that has conducted a comprehensive performance test and 
submitted to the Administrator a Notification of Compliance documenting 
compliance with the standards of part 63, subpart EEE, of this chapter 
may request in the application to reissue the permit for the combustion 
unit that the Director control emissions from startup,

[[Page 59579]]

shutdown, and malfunction events under any of the following options:
* * * * *
    (b) * * * (1) Interim status operations. In compliance with 
Sec. Sec.  265.340 and 266.100(b), the owner or operator of an 
incinerator, cement kiln, lightweight aggregate kiln, solid fuel 
boiler, liquid fuel boiler, or hydrochloric acid production furnace 
that is operating under the interim status standards of part 265 or 266 
of this chapter may control emissions of toxic compounds during 
startup, shutdown, and malfunction events under either of the following 
options after conducting a comprehensive performance test and 
submitting to the Administrator a Notification of Compliance 
documenting compliance with the standards of part 63, subpart EEE, of 
this chapter.
* * * * *
    (2) Operations under a subsequent RCRA permit. When an owner or 
operator of an incinerator, cement kiln, lightweight aggregate kiln, 
solid fuel boiler, liquid fuel boiler, or hydrochloric acid production 
furnace that is operating under the interim status standards of parts 
265 or 266 of this chapter submits a RCRA permit application, the owner 
or operator may request that the Director control emissions from 
startup, shutdown, and malfunction events under any of the options 
provided by paragraphs (a)(2)(i), (a)(2)(ii), or (a)(2)(iii) of this 
section.
    (c) New units. Hazardous waste incinerator, cement kiln, 
lightweight aggregate kiln, solid fuel boiler, liquid fuel boiler, or 
hydrochloric acid production furnace units that become subject to RCRA 
permit requirements after October 12, 2005 must control emissions of 
toxic compounds during startup, shutdown, and malfunction events under 
either of the following options:
    (1) Comply with the requirements specified in Sec.  63.1206(c)(2) 
of this chapter; or
    (2) Request to include in the RCRA permit, conditions that ensure 
emissions of toxic compounds are minimized from startup, shutdown, and 
malfunction events, including releases from emergency safety vents, 
based on review of information including the source's startup, 
shutdown, and malfunction plan and design. The director will specify 
that these permit conditions apply only when the facility is operating 
under its startup, shutdown, and malfunction plan.

PART 271--REQUIREMENTS FOR AUTHORIZATION OF STATE HAZARDOUS WASTE 
PROGRAMS

0
1. The authority citation for part 271 continues to read as follows:

    Authority: 42 U.S.C. 6905, 6912(a), and 6926.

0
2. Section 271.1(j) is amended by adding the following entries to Table 
1 in chronological order by date of publication in the Federal 
Register, to read as follows:


Sec.  271.1  Purpose and scope.

* * * * *
    (j) * * *

               Table 1.--Regulations Implementing the Hazardous and Solid Waste Amendments of 1984
----------------------------------------------------------------------------------------------------------------
                                                                    Federal Register
          Promulgation date               Title of Reglation           reference              Effective date
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
Oct. 12, 2005........................  Standards for Hazardous  [Insert FR page          Oct. 12, 2005.
                                        Air Pollutants for       numbers].
                                        Hazardous Waste
                                        Combustors.
----------------------------------------------------------------------------------------------------------------

[FR Doc. 05-18824 Filed 10-11-05; 8:45 am]
BILLING CODE 6560-50-P


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