[Federal Register Volume 81, Number 83 (Friday, April 29, 2016)]
[Rules and Regulations]
[Pages 26039-26088]
[FR Doc No: 2016-09292]

Vol. 81

Friday,

No. 83

April 29, 2016

Part IV

 Environmental Protection Agency

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40 CFR Part 62

 Federal Plan Requirements for Sewage Sludge Incineration Units
Constructed on or Before October 14, 2010; Final Rule

Federal Register / Vol. 81 , No. 83 / Friday, April 29, 2016 / Rules
and Regulations

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 62

[EPA-HQ-OAR-2012-0319; FRL-9940-50-OAR]
RIN 2060-AR77

Federal Plan Requirements for Sewage Sludge Incineration Units
Constructed on or Before October 14, 2010

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This action finalizes the federal plan for existing sewage
sludge incineration (SSI) units. This final action implements the
Environmental Protection Agency's (EPA) emission guidelines (EG)
adopted on March 21, 2011, in states that do not have an approved state
plan implementing the EG in place by the effective date of this federal
plan. The federal plan will result in emissions reductions of certain
pollutants from all affected units covered.

DATES: The effective date of this rule is May 31, 2016. The
incorporation by reference (IBR) of certain publications listed in the
rule is approved by the Director of the Federal Register as of May 31,
2016.

ADDRESSES: The EPA has established a docket for this action under
Docket ID No. EPA-HQ-OAR-2012-0319. The EPA previously established a
docket for the March 21, 2011, original SSI new source performance
standards (NSPS) and EG under Docket ID No. EPA-HQ-OAR-2009-0559. All
documents in these dockets are listed on the World Wide Web (www),
http://www.regulations.gov index Web site. Although listed in the
index, some information is not publicly available, e.g., Confidential
Business Information (CBI) or other information whose disclosure is
restricted by statute. Certain other material, such as copyrighted
material, is not placed in the Internet and will be publicly available
only in hard copy form. Publicly available docket materials are
available either electronically at http://www.regulations.gov or in
hard copy at the EPA Docket Center (EPA/DC), EPA WJC West Building,
Room 3334, 1301 Constitution Ave. NW., Washington, DC. The Public
Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through
Friday, excluding holidays. The telephone number for the Public Reading
Room is<PHONE_NUMBER>, and the telephone number for the EPA Docket
Center is<PHONE_NUMBER>.

FOR FURTHER INFORMATION CONTACT: Ms. Amy Hambrick, Fuels and
Incineration Group, Sector Policies and Programs Division (E143-05),
Environmental Protection Agency, Research Triangle Park, North Carolina
27711; telephone number:<PHONE_NUMBER>; fax number:<PHONE_NUMBER>;
email address<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:
    Acronyms and Abbreviations. The following acronyms and
abbreviations are used in this document.

ACI Activated Carbon Injection
AG Attorney General
ANSI American National Standards Institute
ASME American Society of Mechanical Engineers
ASTM American Society of Testing and Materials
BTU British Thermal Unit
CAA Clean Air Act
CBI Confidential Business Information
Cd Cadmium
CDX Central Data Exchange
CEDRI Compliance and Emissions Data Reporting Interface
CEMS Continuous Emissions Monitoring Systems
CFR Code of Federal Regulations
CO Carbon Monoxide
CPMS Continuous Parameter Monitoring Systems
EG Emission Guidelines
ERT Electronic Reporting Tool
ESP Electrostatic Precipitators
FB Fluidized Bed
FF Fabric Filter
HCl Hydrogen Chloride
Hg Mercury
IBR Incorporation by Reference
ISTDMS Integrated Sorbent Trap Dioxin Monitoring System
ISTMMS Integrated Sorbent Trap Mercury Monitoring System
MH Multiple Hearth
NAICS North American Industrial Classification System
NESHAP National Emission Standards for Hazardous Air Pollutants
NOX Nitrogen Oxides
NSPS New Source Performance Standards
NTTAA National Technology Transfer and Advancement Act of 1995
Pb Lead
PCDD/PCDF Polychlorinated Dibenzo-P-Dioxins and Polychlorinated
Dibenzofurans
PM Particulate Matter
PRA Paperwork Reduction Act
PS Performance Specifications
RFA Regulatory Flexibility Act
SO2 Sulfur Dioxide
SSI Sewage Sludge Incineration
TEF Toxicity Equivalence Factor
TEQ Toxicity Equivalence
The Court U.S. Court of Appeals for the District of Columbia Circuit
TMB Total Mass Basis
TPY Tons per Year
TTN Technology Transfer Network
UMRA Unfunded Mandates Reform Act of 1995
VCS Voluntary Consensus Standards
WWW World Wide Web

    Organization of This Document. The following outline is provided to
aid in locating information in this preamble.

I. General Information
    A. Does the final action apply to me?
    B. Where can I get a copy of this document?
    C. Judicial Review
II. Background Information
    A. What is the regulatory development background for this final
rule?
    B. What is the purpose of this final rule?
    C. What is the status of state plan submittals?
    D. What are the elements of the SSI federal plan?
III. Affected Facilities
    A. What is a sewage sludge incinerator?
    B. Does the federal plan apply to me?
    C. How do I determine if my SSI unit is covered by an approved
and effective state plan?
IV. Summary of Changes Since Proposal and Response to Public
Comments
    A. Summary of Public Comments and Responses
    B. Affirmative Defense to Malfunctions
V. Summary of Final SSI Federal Plan Requirements
    A. What are the final applicability requirements?
    B. What are the final compliance schedules?
    C. What are the final emissions limits and operating limits?
    D. What are the final performance testing and monitoring
requirements?
    E. What are the final recordkeeping and reporting requirements?
    F. What other requirements is the EPA finalizing?
VI. SSI Units That Have or Will Shut Down
    A. Units That Plan To Close
    B. Inoperable Units
    C. SSI Units That Have Shut Down
VII. Implementation of the Federal Plan and Delegation
    A. Background of Authority
    B. Mechanisms for Transferring Authority
    C. Implementing Authority
    D. Delegation of the Federal Plan and Retained Authorities
VIII. Title V Operating Permits
    A. Title V and Delegation of a Federal Plan
IX. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act (PRA)
    C. Regulatory Flexibility Act (RFA)
    D. Unfunded Mandates Reform Act (UMRA)
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination with
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From
Environmental Health Risks and Safety Risks
    H. Executive Order 13211: Actions That Significantly Affect
Energy Supply, Distribution, or Use

    I. National Technology Transfer and Advancement Act (NTTAA) and
1 CFR Part 51
    J. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income
Populations
    K. Congressional Review Act (CRA)

I. General Information

A. Does the final action apply to me?

    Regulated Entities. Owners or operators of existing SSI units that
are not already subject to an EPA-approved and effective state plan
implementing the March 21, 2011, EG, may be regulated by this final
action. Existing SSI units are those that commenced construction on or
before October 14, 2010. Regulated categories and entities include
those that operate SSI units. Although there is no specific North
American Industry Classification System (NAICS) code for SSI units,
these units may be operated by wastewater treatment facilities designed
to treat domestic sewage sludge. The following NAICS codes could apply
as shown in Table 1 below:

           Table 1--Examples of Potentially Regulated Entities
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                                                 Examples of potentially
            Category               NAICS code       regulated entities
------------------------------------------------------------------------
Solid waste combustors and               562213  Municipalities with SSI
 incinerators.                                    units.
Sewage treatment facilities....          221320  Wastewater treatment
                                                  facilities with SSI
                                                  units.
------------------------------------------------------------------------

    This table is not intended to be exhaustive, but rather provides a
general guide for identifying entities likely to be affected by the
final action. To determine whether a facility would be affected by this
action, please examine the applicability criteria in 40 CFR 62.15855
through 62.15870 of subpart LLL being finalized here. Questions
regarding the applicability of this action to a particular entity
should be directed to the person listed in the preceding FOR FURTHER
INFORMATION CONTACT section.

B. Where can I get a copy of this document?

    In addition to being available in the docket, an electronic copy of
the final action is available on the Internet through the Technology
Transfer Network (TTN) Web site. Following signature by the
Administrator, the EPA will post a copy of this final action at http://www3.epa.gov/ttn/atw/129/ssi/ssipg.html. The TTN provides information
and technology exchange in various areas of air pollution control.
Additional information is also available at the same Web site.

C. Judicial Review

    Under CAA section 307(b)(1), judicial review of this final rule is
available only by filing a petition for review in the U.S. Court of
Appeals for the District of Columbia Circuit (the Court) by June 28,
2016.

II. Background Information

A. What is the regulatory development background for this final rule?

    Section 129 of the CAA, titled, ``Solid Waste Combustion,''
requires the EPA to develop and adopt standards for solid waste
incineration units pursuant to CAA sections 111 and 129. On March 21,
2011, the EPA promulgated NSPS and EG for SSI units located at
wastewater treatment facilities designed to treat domestic sewage
sludge. See 76 FR 15372. Codified at 40 CFR part 60, subparts LLLL and
MMMM, respectively, these final rules set limits for nine pollutants
under section 129 of the CAA: Cadmium (Cd), carbon monoxide (CO),
hydrogen chloride (HCl), lead (Pb), mercury (Hg), nitrogen oxides
(NOX), particulate matter (PM), polychlorinated dibenzo-p-
dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs), and sulfur
dioxide (SO2).
    Sections 111(b) and 129(a) of the CAA address emissions from new
units (i.e., NSPS), and CAA sections 111(d) and 129(b) address
emissions from existing units (i.e., EG). The NSPS are federal
regulations directly enforceable upon SSI units, and, under CAA section
129(f)(1), become effective 6 months after promulgation. Unlike the
NSPS, the EG provide direction for developing state plans; however, the
EG are not themselves directly enforceable. The EG are implemented
under an EPA approved state or tribal plan or EPA adopted federal plan
that implements and enforces them, once the state, tribal, or federal
plan has become effective.
    Section 129(b)(2) of the CAA directs states with existing SSI
unit(s) subject to the EG to submit plans to the EPA that implement and
enforce the EG. The deadline for states to submit state plans to the
EPA for review was March 21, 2012.\1\ Sections 111 and 129(b)(3) of the
CAA and 40 CFR 60.27(c) and (d) require the EPA to develop, implement
and enforce a federal plan for SSI units in any state without an
approvable state plan within 2 years after promulgation of the EG. This
action finalizes the SSI federal plan.
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    \1\ Several states did not submit plans to the EPA by this date.
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    On August 20, 2013, the Court remanded portions of the 2011 SSI
rule for further explanation. National Ass'n. of Clean Water Agencies
v. EPA, 734 F.3d 1115. The Court did not vacate the NSPS or EG, and,
therefore, the requirements of the rules remain in place. The EPA
intends to address the Court's remand in a future rulemaking. The
federal plan is needed to implement the SSI rule in states without an
approved state plan. EPA anticipates that facilities in approximately
eighteen states and nine local air pollution control districts will
need to rely on the SSI federal plan.

B. What is the purpose of this final rule?

    Section 129 of the CAA calls upon states as the preferred
implementers of the EG for existing SSI units. States with existing SSI
units were to submit to the EPA within 1 year (by March 21, 2012)
following promulgation of the EG state plans that are at least as
protective as the EG. Sections 111 and 129 of the CAA and 40 CFR
60.27(c) and (d) require the EPA to develop, implement and enforce a
federal plan within 2 years following promulgation of the EG for
sources in states which have not submitted an approvable plan (by March
21, 2013). The EPA is finalizing the SSI federal plan now so that a
promulgated federal plan will go into place for any such states, thus
ensuring implementation and enforcement of the SSI EG.
    States without any existing SSI units are directed to submit to the
Administrator a letter of negative declaration certifying that there
are no SSI units in the state. No plan is required for states that do
not have any SSI units. SSI units located in states that mistakenly
submit a letter of negative declaration would be subject to the federal
plan until a state plan regulating those SSI units becomes approved.
State plans that have been submitted to implement the March 21, 2011,
EG, have either been approved or are

currently undergoing EPA review. This action finalizes the SSI federal
plan to implement the March 21, 2011, EG for those states that do not
have an approved state plan in place by the effective date of this
federal plan.
    Incineration of sewage sludge causes the release of a wide array of
air pollutants, some of which exist in the waste feed material and are
released unchanged during combustion, and some of which are generated
as a result of the combustion process itself.\2\ The EPA estimated in
the 2011 rule that once the state plans and federal plan become
effective, a total emissions reduction of the regulated pollutants
would occur as follows: Acid gases (i.e., HCl and SO2),
about 450 tons per year (TPY); PM about 58 TPY; non-Hg metals (i.e., Pb
and Cd) about 1.7 TPY; and Hg about 4 pounds per year. The EPA also
estimated that air pollution control devices installed to comply with
the 2011 rule would also effectively reduce emissions of pollutants
such as 7-polycyclic aromatic hydrocarbons, chromium, manganese,
nickel, and polychlorinated biphenyls.
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    \2\ See 76 FR 51371-51375, 51396-51399 and 51399-51400 to
reference the regulatory background, summary of final rule changes
and impacts of the EG adopted on March 21, 2011.
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C. What is the status of state plan submittals?

    Sections 111(d) and 129(b)(3) of the CAA, 42 U.S.C. 7411(d) and
7429(b)(3), authorize and require the EPA to develop and implement a
federal plan for SSI units located in states with no approved and
effective state plan. Table 2 below lists states and territories that
have an EPA-approved plan in effect on the date this final federal plan
is signed by the EPA Administrator. Additionally, Table 2 lists states
and local agencies that submitted negative declarations and or those
which the EPA anticipates taking delegation of the federal plan.

              Table 2--Status of State and Territory Plans
------------------------------------------------------------------------
               Status                               States
------------------------------------------------------------------------
I. EPA-Approved Implementation Plans  New York; Puerto Rico; Virginia;
                                       Michigan; Indiana; Missouri.
II. Anticipated Negative              Huntsville, Alabama; Jefferson
 Declarations to be Submitted to the   County, Alabama; Florida;
 EPA.                                  Jefferson County, Kentucky;
                                       Mississippi; Tennessee; Kansas;
                                       Pima County, Arizona; Pinal
                                       County, Arizona; Hawaii; Washoe
                                       County, Nevada; American Samoa;
                                       Guam.
III. Negative Declaration Submitted/  Maine; Vermont; Virgin Islands;
 EPA Approved.                         District of Columbia; Delaware;
                                       Philadelphia County,
                                       Pennsylvania; West Virginia;
                                       Alabama; Kentucky; South
                                       Carolina; Arkansas; City of
                                       Albuquerque, New Mexico; New
                                       Mexico; Oklahoma; Texas;
                                       Nebraska; Colorado; Montana;
                                       North Dakota; South Dakota; Utah;
                                       Wyoming; Arizona; Idaho; Oregon.
IV. Final Implementation Plans        Georgia.
 Submitted to the EPA.
V. Draft Implementation Plans         Rhode Island.
 Submitted to the EPA.
VI. EPA has not received a draft or   Huntsville, Alabama; Jefferson
 final implementation plan or          County, Alabama; Florida;
 negative declaration.                 Jefferson County, Kentucky;
                                       Mississippi; North Carolina;
                                       Forsyth County, North Carolina;
                                       Mecklenburg County, North
                                       Carolina; Buncombe County, North
                                       Carolina; Tennessee; Iowa;
                                       Kansas; Pima County, Arizona;
                                       Pinal County, Arizona;
                                       California; Hawaii; Washoe
                                       County, Nevada; American Samoa;
                                       Guam; Washington.
VII. Anticipated to Accept            Connecticut; Massachusetts; New
 Delegation of federal plan.           Hampshire; New Jersey; Maryland;
                                       Pennsylvania; Allegheny County,
                                       Pennsylvania; Louisiana; Maricopa
                                       County, Arizona; Nevada; Clark
                                       County, Nevada; Alaska; Puget
                                       Sound Clean Air Agency; Northwest
                                       Clean Air Agency; Southwest Clear
                                       Air Agency.
VIII. Anticipated federal plan        Illinois; Minnesota; Ohio;
 implementation by EPA.                Wisconsin.
------------------------------------------------------------------------

    As the EPA regional offices approve implementation plans, they will
also, in the same action, amend the appropriate subpart of 40 CFR part
62 to codify their approvals. The EPA will maintain a list of
implementation plan submittals and approvals on the TTN Air Toxics Web
site at http://www3.epa.gov/ttn/atw/129/ssi/ssipg.html. The list will
help SSI unit owners or operators determine whether their SSI units are
affected by a state plan or the federal plan.
    Sewage sludge incinerator owners and operators can also contact the
EPA regional office for the state in which their SSI units are located
to determine whether there is an approved and effective state plan in
place. Table 3 lists the names, email addresses and telephone numbers
of the EPA regional office contacts and the states and territories that
they cover.

                                        Table 3--Regional Office Contacts
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                 Region                       Regional contact            Phone         States and territories
----------------------------------------------------------------------------------------------------------------
Region I...............................  Patrick Bird,<PHONE_NUMBER>  Connecticut,
<EMAIL_ADDRESS>                       Massachusetts, Maine, New
                                                                                Hampshire, Rhode Island,
                                                                                Vermont.
Region II..............................  Phillip Ritz,<PHONE_NUMBER>  New York, New Jersey,
<EMAIL_ADDRESS>                       Puerto Rico, Virgin
                                                                                Islands.
Region III.............................  Mike Gordon,<PHONE_NUMBER>  Virginia, Delaware,
<EMAIL_ADDRESS>                        District of Columbia,
                                                                                Maryland, Pennsylvania,
                                                                                West Virginia.
Region IV..............................  Stan Kukier,<PHONE_NUMBER>  Florida, Georgia, North
<EMAIL_ADDRESS>                        Carolina, Alabama,
                                                                                Kentucky, Mississippi,
                                                                                South Carolina,
                                                                                Tennessee.
Region V...............................  Margaret Sieffert,<PHONE_NUMBER>  Minnesota, Wisconsin,
<EMAIL_ADDRESS>                  Illinois, Indiana,
                                                                                Michigan, Ohio.
Region VI..............................  Steve Thompson,<PHONE_NUMBER>  Arkansas, Louisiana, New
<EMAIL_ADDRESS>                     Mexico, Oklahoma, Texas.
Region VII.............................  Lisa Hanlon,<PHONE_NUMBER>  Iowa, Kansas, Missouri,
<EMAIL_ADDRESS>                        Nebraska.

Region VIII............................  Kendra Morrison,<PHONE_NUMBER>  Colorado, Montana, North
<EMAIL_ADDRESS>                    Dakota, South Dakota,
                                                                                Utah, Wyoming.
Region IX..............................  Mark Sims,<PHONE_NUMBER>  Arizona, California,
<EMAIL_ADDRESS>                          Hawaii, Nevada, American
                                                                                Samoa, Guam, Northern
                                                                                Mariana Islands.
Region X...............................  Katharine Owens,<PHONE_NUMBER>  Alaska, Washington.
<EMAIL_ADDRESS>                                         Madonna Narvaez,<PHONE_NUMBER>  Idaho, Oregon.
<EMAIL_ADDRESS>----------------------------------------------------------------------------------------------------------------

D. What are the elements of the SSI federal plan?

    Sections 111(d) and 129 of the CAA, as amended, 42 U.S.C. 7411(d)
and 7429(b)(2), require states to develop and implement state plans for
SSI units to implement and enforce the promulgated EG. Accordingly,
subpart MMMM of 40 CFR part 60 requires states to submit state plans
that include specified elements. Because this federal plan takes the
place of state plans, where approved state plans are not effective, it
includes the same essential elements: (1) Identification of legal
authority and mechanisms for implementation; (2) inventory of SSI
units; (3) emissions inventory; (4) compliance schedules; (5) emissions
limits and operating limits; (6) operator training and qualification;
(7) testing, monitoring, recordkeeping and reporting; (8) public
hearing; and (9) progress reporting. See 40 CFR part 62, subpart LLL,
and sections 111 and 129 of the CAA. Each element was discussed in
detail as it relates to the federal plan in the preamble of the
proposed rule (80 FR 23406). The EPA received a total of ten unique
public comment letters. A summary of these comments and the EPA's
responses is presented in section IV, ``Summary of Changes Since
Proposal and Response to Public Comments'' of this preamble.

III. Affected Facilities

A. What is a sewage sludge incinerator?

    The term ``SSI'' means any unit \3\ that combusts any amount of
sewage sludge located at a wastewater treatment facility designed to
treat domestic sewage sludge, as defined in 40 CFR part 62, subpart
LLL. The affected facility is each individual SSI unit. The federal
plan defines two subcategories for existing SSI units in 40 CFR
62.16045 of subpart LLL: Multiple hearth (MH) incinerators and
fluidized bed (FB) incinerators.
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    \3\ An SSI unit is an enclosed device or devices using
controlled flame combustion that burns sewage sludge for the purpose
of reducing the volume of the sewage sludge by removing combustible
matter. An SSI unit also includes, but is not limited to, the sewage
sludge feed system, auxiliary fuel feed system, grate system, flue
gas system, waste heat recovery equipment, if any, and bottom ash
system. The SSI unit includes all ash handling systems connected to
the bottom ash handling system. The combustion unit bottom ash
system ends at the truck loading station or similar equipment that
transfers the ash to final disposal. The SSI unit does not include
air pollution control equipment or the stack. 40 CFR 62.16045.
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    The combustion of sewage sludge that is not burned in an SSI unit
located at a wastewater treatment facility designed to treat domestic
sewage sludge may be subject to other standards under the CAA.

B. Does the federal plan apply to me?

    The federal plan would apply to the owner or operator of an
existing SSI unit that was constructed on or before October 14, 2010,
and that is not already regulated by an approved and effective state
plan as of the effective date in this notice.\4\ The federal plan would
apply to the SSI unit until the EPA approves a state plan that
regulates the SSI unit and that state plan becomes effective.\5\ If the
construction of an SSI unit began after October 14, 2010, or
modification of an SSI unit began after September 21, 2011, it would be
considered a new SSI unit and would be subject to the NSPS at 40 CFR
part 60, subpart LLLL. The specific applicability of the federal plan
is described in 40 CFR 62.15855 through 62.15870 of subpart LLL.
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    \4\ The federal plan will become effective 30 days after final
promulgation.
    \5\ A state plan is effective on the date specified in the
notice published in the Federal Register announcing the EPA's
approval of the plan.
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    This action will not preclude states from submitting a state plan
at a later time. If a state submits a plan after the promulgation of
the SSI federal plan, the EPA will review and approve or disapprove the
state plan.\6\ If the EPA approves a plan, then the SSI federal plan no
longer applies to SSI units covered by the state plan. If an SSI unit
was overlooked by a state and the state submitted a negative
declaration letter, or if an individual SSI unit was not covered by an
approved and effective state plan, the SSI unit would be subject to
this federal plan.
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    \6\ An approved state plan is a plan developed by a state that
the EPA has reviewed and approved based on the requirements in 40
CFR part 60, subpart B, to implement 40 CFR part 60, subpart MMMM.
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C. How do I determine if my SSI unit is covered by an approved and
effective state plan?

    Part 62 of title 40 of the CFR identifies the status of approval
and promulgation of CAA section 111(d) and CAA section 129(b) state
plans for designated facilities in each state. However, 40 CFR part 62
is updated only once per year. Thus, if 40 CFR part 62 does not
indicate that a state has an approved and effective plan, please
contact the state environmental agency's air director or the EPA's
regional office (see Table 3 in section II.C of this preamble) to
determine if approval occurred since publication of the most recent
version of 40 CFR part 62.

IV. Summary of Changes Since Proposal and Response to Public Comments

    This rule will be finalized as proposed except where the EPA
revised the regulatory text to make certain clarifications. After
consideration of all the public comments received, in the response to
public comments below, the EPA clarified the compliance date, operator
training requirements, the federal plan delegation process, certain
performance monitoring and testing provisions, status of state plan
submittals, and the inventory of units. The EPA received a total of ten
unique public comment letters on the proposed federal plan rulemaking.
(Note, one letter was inadvertently duplicated and submitted to the
docket.\7\) No public hearing was requested, and, therefore, none was
held.
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    \7\ Docket Identification Numbers EPA-HQ-OAR-2012-0319-0016 and
EPA-HQ-OAR-2012-0319-0017 are the same comment.
---------------------------------------------------------------------------

    The EPA believes that it is critical to highlight that the final
compliance date remains, as proposed, March 21, 2016. Commenters raised
concerns that the two proposed pathways for compliance implied that the
compliance date was longer than statutorily allowed. Therefore, the EPA
removed these pathways in the regulatory text to clarify the final
compliance date.

    Commenters raised numerous comments on the federal plan's
monitoring and testing provisions, most of which the EPA did not
propose to revise or otherwise solicit comment on in the proposed
federal plan. Section 129 of the CAA requires the EPA to develop a
federal plan to assure that existing units are in compliance with the
EG. Many of the comments received on the proposed federal plan's
monitoring and testing provisions recommended changes to the EG, which
are outside the scope of this action. For that reason, we are not
making these changes at this time in the federal plan. An example of
these changes is adjusting the minimum percent of the maximum permitted
capacity during testing, which is currently promulgated in the EG at
85-percent. In the April 27, 2015, federal plan proposal the EPA did
solicit comment on a potential revision to this provision.\8\ The EPA
is not revising the minimum threshold provision in the federal plan,
but will consider whether to do so in a future rulemaking action. With
respect to all other comments addressing monitoring and testing
provisions in the EG, those comments are outside the scope of this
action. However, we do provide some clarifications of the requirements
of the EG in response to those comments later in the preamble for this
federal plan. We will consider making changes to the EG and federal
plan to incorporate the suggested revisions in the future. In addition,
many of the commenters' concerns may be addressed through the federal
plan, which provides the EPA Administrator with the authority to
approve alternate methods of demonstrating compliance as established
under 40 CFR 60.8(b) and 60.13(i). SSI unit owners and operators who
wish to petition the agency for an alternative method of demonstrating
compliance should submit a request to the Regional Administrator with a
copy sent to the appropriate state.
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    \8\ See 80 FR 23404.
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    A full summary of the public comments and responses to the public
comments is provided below in section IV.A. of this preamble.

A. Summary of Public Comments and Responses

    In this section, we provide the EPA's responses to all of the
public comments received.\9\ All of the public comment letters received
are located in the docket, which can be accessed by following the
instructions outlined in the ADDRESSES section of this preamble.
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    \9\ All of the public comments received are identified in the
memorandum titled, ``Public Comments Received on the Proposed
Federal Plan Requirements for Sewage Sludge Incineration Units
Constructed on or Before October 14, 2010,'' located in the docket.
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1. Compliance Schedule
    Comment: Several commenters (08, 11, 12, 14) point out that the
proposed final compliance date of March 21, 2016, is contradictory to
the schedules of the compliance pathways proposed in 40 CFR 62.15875
given that it is less than 1 year after the close of the public comment
period. Commenters believe that the proposed compliance pathways are
unclear and imply that the final compliance date could be after March
21, 2016. Specifically, the proposed 40 CFR 62.15875 outlined two
compliance pathways. The first pathway was to achieve final compliance
by 1 year from the date of publication of the final federal plan in the
Federal Register. The second pathway was to achieve final compliance
more than one year following the date of publication of the final
federal plan in the Federal Register by meeting the increments of
progress specified in Table 1 of the proposed rule (increment 1: Submit
final control plan 3 months from the date of publication of the final
rule in the Federal Register and increment 2: Final compliance by March
21, 2016). Commenters (08, 11, 12, 14) request that EPA clarify the
final compliance date and the schedules in the compliance pathways.
    Two commenters (11, 12) specifically request that the EPA revise 40
CFR 62.15875 as follows:
     One (1) year after publication of the final federal plan
in the Federal Register, or
     For affected sources planning to comply more than one (1)
year after the final federal plan, meeting increments of progress for
submitting a final control plan within six (6) months after the final
federal plan is published and final compliance by two (2) years after
the publication of the final federal plan in the Federal Register.
    Commenters (11, 12) express concern that, due to the delays from
the petitioned SSI reconsideration and the federal plan development,
the federal plan will negatively affect utilities' efforts to plan for
compliance. Another commenter (14) reiterates this concern notably for
smaller to mid-size wastewater utilities. The commenter (14) further
highlights the short window for compliance and that facilities will
likely have to take further regulatory action in areas such as
greenhouse gas emissions, industrial pretreatment, anti-terrorism
safeguards, and nutrient removal in addition to the numerous other
rules and requirements that they are currently required to follow. The
commenter states the financial impact this regulation has already had
on its facility (estimated at $45,000 for administration and reporting,
$25,000 for fees, $65,000 for third-party audits, and $50,000 for a
compilation of reports for state and federal agency reporting) and
anticipates ongoing cost to ratepayers. A separate commenter (12) asks
that the final federal plan contain a mechanism modeled on the
provisions at 40 CFR 62.14536, which allow operators to petition for
compliance extensions on a case-by-case basis.
    Response: The EPA agrees with commenters that clarification of the
compliance date and compliance pathways is necessary, but disagrees
that a later compliance date is needed and notes that a later
compliance date is not authorized by CAA section 129. In addition,
comments regarding the appropriate compliance date are outside the
scope of this action, and EPA did not propose any revisions to the
compliance date. The EPA clarifies that the final compliance date is
March 21, 2016.\10\ This compliance date was established in the March
21, 2011, EG. In addition, similar to the implementation of other EG
under CAA section 129, the EPA proposed two compliance pathways, which
would allow owners or operators of SSI units to either: (1) Come into
compliance with the plan within 1 year after the plan is promulgated;
or (2) meet increments of progress and come into compliance by the
final compliance date.\11\ This framework was intended for a federal
plan that was promulgated on schedule as required by sections 111 and
129(b)(3) of the CAA and 40 CFR 60.27(c) and (d), which require the EPA
to develop, implement and enforce a federal plan for SSI units in any
state without an approvable state plan within 2 years after
promulgation of the EG. In this case, 2 years after the promulgation of
the EG would have been by March 21, 2013. The EPA recognizes that
because this federal plan is being finalized after the 2-year timeframe
from the promulgation of the EG, it is not practical to retain these
two pathways in the final federal plan, as the pathway with increments
of progress would not comport with the final compliance date
established by the EG. In fact, the EPA recognizes that by proposing
these pathways, many commenters were

confused and stated that they interpreted that the final compliance
date was after March 21, 2016, which is not what the EPA intended.
---------------------------------------------------------------------------

    \10\ If a facility is complying with a state implementation
plan, the compliance date may be earlier than March 21, 2016.
    \11\ 2010 State Implementation Guidance Document is available
through the EPA's TTN at http://www3.epa.gov/ttn/atw/129/hmiwi/epa453b10001_hmiwi.pdf.
---------------------------------------------------------------------------

    Therefore, the EPA is revising the final rule to require that all
SSI unit owners or operators submit a final control plan and achieve
final compliance by March 21, 2016. The EPA has concluded that most
facilities already have a final control plan in place and know what
measures they are required to take in order to achieve compliance.
    The EPA disagrees with the commenter's suggested framework for
allowing facilities to achieve final compliance up to 2 years after the
publication of the final federal plan in the Federal Register. This
would violate the statute, as section 129 of the CAA directs the EPA to
implement the federal plan so that the plan will assure that each unit
subject to the plan is in compliance with all provisions no later than
5 years after the date of the promulgation of the emissions guidelines,
which was March 21, 2011.
    The EPA disagrees with using a mechanism modeled on the provision
at 40 CFR 62.14536 as there is no statutory authority under CAA section
129 for providing compliance extensions (i.e., allowing compliance
after the compliance date). Lastly, the EPA disagrees that affected
sources have had inadequate time to prepare to comply with this rule.
The commenters do not point to any specific circumstances where
compliance is not possible. In fact, one commenter notes that sources
have been working to come into compliance since the March 2011 final
rule was issued. The federal plan implements the EG for existing SSI
units, which was promulgated on March 21, 2011.\12\ We believe that
sources have had ample notification of this final compliance date and
that they are aware of what measures they must take in order to comply.
---------------------------------------------------------------------------

    \12\ See 76 FR 15372.
---------------------------------------------------------------------------

2. Operator Training
    Comment: Several commenters (08, 11, 12, 14) express varying
opinions on the proposed operator training requirements. One commenter
(08) points out that the proposed 40 CFR 62.15920(b) requires that
operator training and qualification must be obtained through a state-
approved program or by completing the requirements that the section
outlines. Proposed 40 CFR 62.15920(c) requires that operators must pass
an examination designed and administered by a state-approved program or
an administering instructor. The commenter suggests that some states
will have neither created or identified an approved SSI operator
training program, nor have identified any state-approved instructors to
administer the training and examination. The commenter is concerned
that the facility and operator would be in a situation in which it
would be impossible to comply with the rule through no fault of the
facility or operator.
    Other commenters (11, 12) express appreciation of the EPA's
flexibility on who can administer the SSI operator training program and
the examination. Commenter (12) requests that the EPA verify its
interpretation of the operator training requirements. Specifically, the
commenter raises that, based on email correspondence with the EPA, they
understand that the proposed operator training requirements mean that a
third-party or utility could develop a training program and exam and it
need not be approved by the state or the EPA as long as it meets the
requirements in 40 CFR 62.15920(c). The commenter states that they
understand that this interpretation is only with respect to states that
do not have approved state plans in place and that, once a state plan
is approved by the EPA, upon the effective date of a state plan, the
federal plan would no longer apply as of the effective date of a state
plan. Any operator training requirements would have to comply with the
state plan.
    Another commenter (14) is concerned that it will be difficult to
meet the operator training requirements when no state training program
exists.
    Response: As the EPA recently clarified in a webinar on June 2,
2015, to states, tribes, territories, and local air agencies, the
federal plan would require that an SSI unit cannot be operated unless a
fully trained and qualified SSI unit operator is accessible, either at
the facility or nearby such that the operator can be at the facility
within 1 hour.\13\ Operator training and qualification must be obtained
through a state-approved training program or by completing the list of
training requirements included in the proposed federal plan. The EPA
explained that if a state program does not exist, facilities complying
with the federal plan must complete the list of training requirements
in order to comply with the rule.
---------------------------------------------------------------------------

    \13\ EPA's outreach webinar on the federal plan proposal can be
found at the SSI regulation Web site: http://www3.epa.gov/ttn/atw/129/ssi/ssipg.html.
---------------------------------------------------------------------------

    Section 62.15920(b) of 40 CFR part 62 clearly states that there are
two options for complying with the operator training requirements. The
first option is to obtain training and qualification through a state-
approved program. The second option is to obtain training and
qualification through completing an incinerator operator training
course that includes at a minimum the topics listed in 40 CFR
62.15920(c). The rule further requires operators to complete an
examination designed and administered by the state-approved program or
an instructor administering the training topics listed in the rule. The
rule also states that operators are required to conduct initial
training and annual refresher trainings in addition to retaining
documentation on-site of completed operator training. The EPA provides
the following examples of how a training and examination program could
work in order to comply with the requirements:
     Example 1: A third party administers an SSI operator
training course and examination. The training course and examination
syllabus cover the topics as described in 40 CFR 62.15920(c).
     Example 2: An affected SSI facility with necessary
technical expertise administers an ``in-house'' SSI operator training
course and examination. The training course and examination syllabus
cover the topics as described in 40 CFR 62.15920(c).
     Example 3: SSI operators complete an SSI operator training
course and examination through a state-approved training program (e.g.,
state-approved trainer or state-run program; may vary by state).
    The EPA further clarifies that ``state approved training program''
is not a ``state implementation plan''. The EPA recognizes that
different states may have their own requirements for professional
trainers in their states even if they do not have a state
implementation plan in place. SSI unit owners and operators are
encouraged to contact their state to find out if their state has its
own requirements for trainers. Once a state plan is approved by the
EPA, upon the effective date of a state plan, the federal plan would no
longer apply to SSIs in that state. The state or local agency would
implement and enforce the approved state plan in lieu of the federal
plan and operator training requirements would have to conform with the
state plan.
3. Performance Testing and Monitoring
    As the EPA discussed in the federal plan proposal, we will not
address comments on the underlying SSI EG, since those comments address
issues

outside the scope of the federal plan.\14\ We note that this section
addresses issues that the EPA believes warrant clarification, even
though they are not within the scope of this action. Many of the
comments received on the proposed federal plan's monitoring and testing
provisions recommend changes to be made in the EG, and since no such
revisions were identified in the proposed federal plan, we are not
making these changes at this time in the federal plan. We will consider
making changes to the EG and corresponding changes to the federal plan
to incorporate the suggested revisions in the future. However, the
responses below provide clarification regarding the requirements of
certain monitoring and testing provisions.
---------------------------------------------------------------------------

    \14\ See 80 FR 23404.
---------------------------------------------------------------------------

    Comment: Multiple commenters (11, 12, 13, 18) respond to the EPA's
solicitation of comments regarding the proposed provision at 40 CFR
62.16015, which would require SSI units to operate at a minimum of 85-
percent of the maximum permitted capacity during performance testing.
The EPA specifically solicited comments and additional data on whether
the 85-percent requirement warrants a revision due to operational
limitations or other factors. Two commenters (12 and 18) state that the
capacity at which SSIs test will drive the overall setting of operating
parameters that: (1) May be impossible to maintain at a lower (more
real-world) throughput rate, and (2) if possible to maintain, may have
negative environmental and cost implications. Under one commenter's
(18) title V permit, stack tests are required and set the maximum (with
an allowable exceedance up to 10-percent) for dry-tons-per-day solids
loading. The commenter argues that using a stack test to set the
maximum throughput makes sense when the stack test results are also
used to set operating parameters. In addition, for this commenter, the
permitted throughput is calculated as an average of three test runs,
and two commenters (12 and 18) request the EPA to consider including
this in the federal plan.
    Commenters (12 and 18) provide the example that an SSI unit with a
higher feed rate will have a higher air flow and, therefore, a higher
pressure drop; pressure drop is one of the operating parameters that
must be established. Under normal feed rates, SSIs will have lower air
flows and lower pressure drops. They state that it may be necessary for
some utilities attempting to achieve combustion zone temperature limits
established for higher loading conditions to use auxiliary fuel to
artificially increase bed temperature to meet the operating limit at
lower loading conditions.
    Commenters (12 and 18) discuss that it is not practical or
economical for many SSIs to maintain a level of 85-percent during
normal operations in order to ensure that operating parameters set at
this level are consistently met. The commenters discuss that operation
at this higher level will require frequent start/stop cycles, which
accelerates the thermal aging of the system, shortens the useful life
of the unit, results in highly variable feed composition, and uses more
auxiliary fuel for stable operation. The commenters believe that these
adverse impacts further increase the operating cost and adversely
impact emissions from SSIs due to excessive fuel use and increased
frequency of startup and shutdown modes. In other words, this would
result in increased energy consumption and greenhouse gas emissions.
    One commenter (12) explains that some SSI facilities have had to
store sludge for extended periods of time to accumulate enough material
to meet this requirement, as many SSIs routinely operate significantly
below their maximum permitted capacity. If an operating facility has to
store sludge to meet the 85-percent feed rate, the characteristics of
the sludge will change, resulting in different operating requirements
and performance for stored sludge than non-stored sludge processed
during average conditions. The commenter further explains that many
utilities simply do not generate enough sludge to burn at 85-percent of
permitted capacity consistently. The commenter describes how sludge is
fed at a rate to maintain a specific and narrow combustion temperature
range. Variations in sludge composition will vary the feed rate as the
commenter describes. During one SSI facility's recent performance test
run, the sludge's percent volatile solids and British Thermal Unit
(BTU) content were significantly higher than normal, which resulted in
feed rates less than 85-percent as the SSI's BTU input capacity was
reached. In other cases, SSI units have not been able to maintain feed
rates at 85-percent of their permitted maximum capacity and also
maintain other operating conditions during testing, resulting in test
runs that do not meet the regulatory requirements (e.g., sludge
volatile content and other sludge characteristics can vary
significantly and feed rates must be adjusted to maintain target
combustion temperatures).
    One commenter (12) reminds the EPA of their comments submitted on
the October 14, 2010, proposal of the EG and NSPS (75 FR 63260) in
which they stated that EPA's assumption that SSIs operate at 75-percent
of the rated capacity was too high and that the EPA needed to consider
other options.\15\ The commenter further highlights their November 29,
2010, comment that raised concerns about requiring a specific operating
parameter for feed rate. The commenter believes that the 85-percent
requirement was added at the 2011 final rule stage of the EG and NSPS
as the EPA attempted to address the issue that their November 29, 2010,
comments raised at the time. They further believe that the EPA removed
the operating parameter for sludge feed rate and the requirement to
regularly operate within that range, but the agency then added the 85-
percent requirement for performance testing. The commenter requests
that the EPA eliminate the 85-percent requirement and instead require
the use of a minimum feed rate based on actual historical operating
averages (i.e., the baseline would be each SSI's historical operating
baseline, instead of permitted capacity). The commenter states that the
EPA has previously suggested in email correspondence and phone
conversations that testing be conducted at both 85-percent of permitted
capacity and at the historical operating average feed rates in order to
establish the operating parameters at regular or normal feed rates. The
commenter does not think that this is acceptable because this would
require two separate compliance demonstration source tests and
effectively double the cost of performance testing. They also do not
think that there is valid regulatory purpose for establishing operating
parameters at higher operating capacities (e.g., 85-percent) than are
normally encountered, so they request that the EPA revise this
requirement to instead require testing based on actual/historical
operating average.
---------------------------------------------------------------------------

    \15\ See November 29, 2010, comment submitted by the National
Association of Clean Water Agencies. Document identification number
EPA-HQ-OAR-2009-0559-0127.1. http://www.regulations.gov.
---------------------------------------------------------------------------

    Commenter (11) discusses that their unit is rated by the
manufacturer at a sludge feed rate of 2.0 dry-tons-per-hour. The rating
was based on assumptions during its design, including volatile solids
percentage in sludge. The commenter states that the SSI unit has never
achieved the design sludge feed rate, much in part because the measured
volatile solids content has been consistently higher than the design

assumption. Under a normal optimal operation, the commenter can run a
feed rate of 1.4-1.5 dry-tons-per-hour, which is at 75-percent of rated
capacity. However, they describe that there are extended periods of
time where the SSI unit operates at lower feed rates (e.g., 1.1 dry-
ton-per-hour), which is 55-percent of rated capacity. The commenter
explains that sludge feed rate dictates the target combustion
temperature to achieve optimal combustion conditions while generating
the least quantity of air pollutants. While the commenter will seek a
lower permitted capacity in its air permit, it is likely that the SSI
unit will not continuously operate within 85-100-percent capacity
range, including during test conditions. The commenter describes how
operators must respond to varying conditions such as sludge quality,
fluidized sand condition, and combustion air flow and temperature. The
commenter believes that sludge feed rate should not be specified in the
operation of an SSI, including during performance testing. The
commenter asks the EPA to provide relief in this requirement by either
expanding the minimum percentage requirement, or by implementing
another means to determine ``normal operation''. One suggestion they
recommend is to require that a performance test be conducted at a
sludge feed rate within plus or minus 20-percent of the average sludge
feed rate during the past six months of SSI unit operation.
    Commenter (13) recommends that the 85-percent threshold be replaced
with a requirement that the minimum feed rate be based on historical
operating average. The commenter explains that this suggestion is
primarily due to the variability of the sludge feed (e.g., percent
solids, percent volatile solids, BTU content, percent primary sludge v.
percent waste activated sludge, etc.), which impacts throughput.
Furthermore, the commenter states that SSI facilities are finding that
they will not be able to continuously meet some of the site-specific
operating limits (e.g., wet scrubber pressure drop) established at 85-
percent threshold or higher, when operating their incinerators at
normal (lower) feed rates.
    Response: While we solicited comment on the 85-percent of maximum
permitted capacity performance testing requirement, the EPA has decided
that it is not appropriate to make changes to the requirement at this
time, in order to avoid inconsistencies between the federal plan and
the EG, since the federal plan is intended to implement the EG. The EPA
thanks the commenters for their valuable feedback and ideas. We will
consider making changes to the EG and corresponding changes to the
federal plan to address the suggested revisions in the future. If a
particular operating parameter is inappropriate for a site-specific
configuration, the facility may submit an alternative monitoring plan
to the appropriate EPA regional office pursuant to 40 CFR 62.16050, 40
CFR 60.8 and 60.13.
    Comment: One commenter (11) discusses the proposed 40 CFR
62.15995(a)(3)(ii)(C), which includes specific requirements for
installation of a pH monitoring system if a scrubber is designed to
control emissions of HCl or SO2. Specifically, 40 CFR
62.15995(a)(3)(ii)(C)(1) will require that a pH sensor be placed in a
position at the scrubber effluent. The commenter explains that the
requirement will cause issues in establishing an operating limit and in
operating and maintaining the pH probe because of the elevated
temperature of scrubber effluent and presence of erosive ash and sand
particulate. The commenter further explains that it is likely that the
pH probe measurement will drift under these conditions. Additionally,
regarding the establishment of operating limits, the commenter believes
that it is likely that the pH of scrubber effluent will vary during a
performance test, depending on the varying presence of HCl and/or
SO2 removed from the gas stream. The commenter states that
using scrubber effluent pH is inconsistent with engineering design for
scrubbers designed to remove acidic or alkaline gases from process air
or flue. Typically, the adjustment and measurement of scrubber pH
liquid is important for the feed (or influent) into a scrubber system.
In a semantic sense, the term ``scrubber liquid pH'' used in 40 CFR
62.15985(a)(1) is typically understood to be the liquid introduced
(i.e., feed) into a scrubber. This is a fundamentally different term
than ``scrubber effluent pH,'' as noted in 40 CFR
62.15995(a)(3)(ii)(C). The commenter recommends that the pH of scrubber
liquid, specifically the feed water into a scrubber, be used for
establishing operating limits. The commenter also states that the pH
monitoring system should be placed at the feed water, and not the
scrubber effluent.
    Response: This comment is outside the scope of the SSI federal
plan, since the federal plan is intended to implement the EG. The EPA
thanks the commenters for their valuable feedback and ideas. We will
consider making changes to the EG and federal plan to incorporate the
suggested revisions in the future. If a particular operating parameter
is inappropriate for a site-specific configuration, under 40 CFR
62.16050, 40 CFR 60.8 and 60.13, the facility may submit an alternative
monitoring plan to the appropriate EPA regional office.
    Comment: One commenter (08) describes that the proposed 40 CFR
62.15995 includes requirements to prepare site-specific monitoring
plans for continuous parameter monitoring systems (CPMS). The proposed
rule contains specific sensitivity specifications for certain types of
CPMS. The commenter explains that most SSIs have been operating
satisfactorily with legacy CPMS, installed at the time of installation
or shortly thereafter as the ``kinks'' were worked out. At this time,
however, it is often impossible to obtain performance specifications
for the CPMS components or the overall CPMS, for a variety of reasons.
The commenter discusses that, when the equipment was purchased,
performance specifications with that degree of granularity were often
not required as part of equipment specification. It may be impossible
to now obtain the data retroactively from vendors or manufacturers,
because suppliers are no longer in business, or the manufacturers did
not acquire or retain the data because it was not required. Thus there
will be situations in which an affected SSI unit has an existing
continuous parameter monitoring equipment that is working
satisfactorily with years of reliable performance, but for which the
operator cannot produce the ``paperwork'' documenting that the unit
meets the performance specification of the proposed 40 CFR 62.15995.
The commenter asks the EPA what alternatives are available to operators
of SSI units in these circumstances. The commenter also asks that if
the rule is promulgated as proposed, will the operators of those SSI
units be required to replace working and effective CPMS simply for the
lack of ``paperwork''. The commenter believes that discarding equipment
that is working for lack of ``paperwork'' seems unnecessary and
wasteful, particularly since newer equipment with greater sensitivity
might actually be more susceptible to breakdown or performance
excursions.
    Response: While the EPA has stated its belief that it is prudent
for records of specifications for measurement equipment to be kept, the
EPA understands that these records may no longer exist. In cases where
this information no longer exists, that reason alone will not require
facilities to replace their equipment. Instead, the facility may
demonstrate that the equipment meets the requirements

given in the rule. For example, for temperature measurements, such a
demonstration could rely on comparison to a redundant temperature
measurement device, a calibrated temperature measurement device or a
separate sensor check and system check by temperature simulation.
    It is important for monitoring equipment to meet minimum
specifications in order to return data of known quality. While the
monitor may be working, without data of known and satisfactory quality,
neither the owner or operator nor the EPA can be assured that the
facility is in compliance.
    Comment: One commenter (08) identifies that the proposed 40 CFR
62.15995(a)(7) would establish requirements to determine when a
continuous monitoring system (CMS) is out of control. They specify that
paragraph (a)(7)(i) sets forth that a CMS system would be deemed to be
out of control if drift exceeds two times the applicable calibration
drift specification (paragraph (a)(7)(i)(A)) or the unit fails certain
required performance test audits (paragraph (a)(7)(i)(B)). As the
commenter reads the proposed federal plan, the universe of CMS that
fall under this provision is unclear. They discuss that one
interpretation is that the proposed federal plan applies to all CMS,
which would indicate that an ``out-of-control'' specification would
need to be developed for each CMS. Following this interpretation, all
CMS that are not subject to performance audits would need to develop an
``out-of-control'' drift specification. The commenter asks how ``out-
of-control'' specifications would be developed for CMS that are subject
neither to a performance audit nor to drift. The commenter has an
alternate interpretation of 40 CFR 62.15995(a)(7), which is that it
applies only to CMS for which drift is a meaningful and relevant
concern. The commenter believes that the rule as written, however, does
not clearly limit 40 CFR 62.15995(a)(7) to such situations.
    Response: The rule applies to all CMS. Section 62.15995 of 40 CFR
part 62 requires owners or operators to develop and submit for the
Administrator's approval site-specific monitoring plans for each CMS.
Section 62.15995(a)(3) of 40 CFR part 62 requires owners or operators
to identify ongoing performance evaluations in their site-specific
monitoring plans for all CMS (both CEMS and CPMS). A failure of one of
these ongoing activities (e.g., the performance evaluation described in
the site-specific monitoring plan) constitutes an out-of-control period
and triggers corrective action. The EPA further notes that owners and
operators must conduct a performance evaluation of a pressure sensor no
less frequently than annually per 40 CFR 62.1995(a)(3)(ii)(B)(5).
    Comment: Two commenters (12 and 13) identify that under the EG and
the proposed federal plan, the lowest 4-hour average effluent water
flow rate at the outlet of the wet electrostatic precipitator (WESP)
recorded during the most recent performance test demonstrating
compliance with the particulate matter, lead, and cadmium limits,
becomes the WESP's site-specific minimum water effluent flow rate.
Commenters discuss that the data are supposed to be measured and
recorded on an hourly basis, and compliance is determined on a 12-hour
block average. Commenter (13) specifically notes that the EG only
requires three 1-hour long performance test runs, which means that the
minimum water effluent flow rate will actually be the lowest 1-hour
average. Both commenters convey that water does not continuously run
through a WESP. A WESP is only flushed (clean) with water approximately
once every 6 hours and the flush lasts for approximately 3 minutes.
Commenter (13) explains that the rate at which flushing water is added
to the WESP is normally in the range of 50-100 gallons per minute, but
it can vary depending on the size of the unit.
    Commenter (13) states that unlike other industries, all of the
WESPs located at publicly owned treatment works (POTWs) are preceded by
wet scrubbing systems and the gas stream entering the WESP is saturated
with moisture. As a result, there is no need to install water sprays
prior to the WESP's inlet. The commenter asks whether the use of water
sprays in other industries is the reason that the minimum water
effluent limit was included in the SSI rules. The commenter explains
that unless flushing water is being utilized, the water effluent flow
rate recorded during the performance test will only consist of a small
amount of moisture that has been carried over from the wet scrubbers
and the condensation that occurs within the WESP. A number of POTWs
combine the effluent from their wet scrubbers and WESPs into a single
pipe, making it almost impossible to accurately measure the WESP water
effluent. The commenter requests that POTWs be allowed to monitor the
WESP's flushing water inflow in lieu of measuring the WESP's effluent,
if this requirement is retained in the final federal plan.
    Commenter (12) states that the rule requires a minimum water flow
rate for the WESP in gallons-per-minute (gpm), just like the scrubber
water flow rate. Scrubber water, however, flows continuously while
WESPs are only flushed once every 6 hours. Since the flushing water is
not continuous, SSI unit owners and operators have difficulty
developing a minimum flow rate. In addition, a WESP gravity effluent
pipe with a diameter of 4 inches or 6 inches, necessary to avoid
clogging in some configurations, is too large for a meter to accurately
measure the low rate of flow. In some cases, WESP effluent flows into a
common drain pipe where backflow into the drain can affect the accuracy
of the reading. One SSI unit owner/operator requests that they be
allowed to measure the water feed to the WESP, instead of measuring the
flow at the outlet of the WESP. The influent flow rate will be greater
than or equal to the effluent rate due to possible evaporation within
the unit. However, the commenter has a more basic question as to why
the rule requires a minimum WESP effluent water flow rate as a site-
specific operating parameter. Based on the information the commenter
has collected, water flow does not change the WESP's collection
efficiency. In fact, at some times, there can be more water draining
out of the WESP then is being added to it. The exception is when
flushing occurs, which is due to the condensation of the moisture in
the exhaust gases that have been saturated in the wet scrubbers. The
commenter requests clarification on this topic in the final federal
plan.
    Similarly, another commenter (16) believes that 40 CFR 62.15985 as
proposed is impractical. The commenter states that 40 CFR 62.15985
indicates that water flow rate at the outlet of the WESP must be
monitored. The commenter remarks that water usage by the WESP is
intermittent and at many times too minimal for a mag-meter of the size
necessary on the effluent pipe to accurately measure. A pressurized
influent pipe supplying water to the WESP is much smaller, improving
the accuracy of the mag-meter. The commenter describes that a WESP
gravity effluent pipe with a diameter of 4 inches to 6 inches,
necessary to avoid clogging, is too large for a mag-meter to accurately
measure the low rate of flow.
    Commenter (13) references EPA guidance document for ``Compliance
Assurance Monitoring'' (CAM) that covered WESPs used for particulate
matter control; voltage was listed as the prime and only measurement
for compliance monitoring. The commenter states that this document also
acknowledged that wash water is only used on an intermittent basis and
results

in slight and temporary reductions in voltage. Since the water effluent
flow rate is not indicative of a WESP's removal efficiency, WESPs are
subject to a site-specific secondary voltage or amperage operating
limit, and WESPs located at POTWs do not require water sprays, the
commenter asks the EPA to consider eliminating the WESP water effluent
operating parameter from the EG and final federal plan.
    Response: The choice of site-specific operating parameters is
outside the scope of the federal plan, and EPA did not propose or
solicit comment on revisions to these provisions. The EPA thanks the
commenters for their valuable feedback and ideas. We will consider
making changes to the EG and federal plan to incorporate the suggested
revisions in the future. The EPA recognizes that the commenters have
asked for clarifications on some of the points related to WESP water
flow and we provide clarification below.
    First, commenters note that the lowest 4-hour average effluent
water flow rate at the outlet of the WESP, recorded during the most
recent performance test demonstrating compliance with the PM, Pb, and
Cd limits, becomes the WESP's minimum water effluent flow rate, but
that the regulation only requires three 1-hour performance test runs,
which means that the minimum water effluent flow rate will actually be
the lowest 1-hour average. The EPA notes that the regulation requires a
minimum sample volume for each test run, not a minimum sample time. It
is possible that some performance tests for PM and metals may not
require 4 hours in total to achieve the minimum sample volume for the
three runs. However, because the operating parameters must be set based
on a 4-hour average from the performance test, the EPA has concluded
that it is necessary to test for at least 4 hours (in total, not per
run), even if this means collecting more than the minimum sample volume
prescribed in the rule.
    Second, the EPA is clarifying why effluent water flow is an
appropriate operating parameter for a WESP and why it accurately
reflects a WESP's ability to efficiently collect PM. All ESPs operate
under the principle that opposite charges exist between the plates and
the particles. When the plates become too caked with collected
particles, there will no longer be enough pull from the plates to
attract the particles from the incoming gas stream. The plates must be
continuously or intermittently (at regular intervals) washed to
maintain the attraction. In some situations, either influent or
effluent water flow can provide an adequate indicator of performance.
However, as one commenter noted, sometimes the influent flow rate is
maintained at greater than or equal to the effluent rate due to
possible evaporation within the unit. In this type of situation, it is
important to monitor the effluent flow rather than the influent flow.
If the water evaporates and does not make it all the way through the
system and does not clean all of the plate surfaces, than the water
flow is not adequate, but this would not be reflected if measuring
inlet flow rate. Further, the commenter's assertion that the EPA's CAM
guidance lists voltage as the prime and only measurement for compliance
monitoring is incorrect. The CAM guidance is meant only to provide
examples for operating parameters for different control devices; it is
not meant to be all inclusive. However, the second example for WESP in
the CAM guidance lists three different monitoring parameters: secondary
voltage, quench inlet temperature, and WESP outlet temperature. The
WESP outlet temperature measurement serves as an indicator of water
flow through the system, thereby demonstrating that even in the CAM
guidance the EPA has acknowledged the importance of water flow in a
WESP.
    The EPA also reminds commenters that if a particular operating
parameter is inappropriate for their site-specific configuration, under
40 CFR 62.16050, 40 CFR 60.8 and 60.13 the facility may submit an
alternative monitoring plan to the appropriate EPA regional office.
    Comment: One commenter (12) discusses that the 2011 EG and proposed
federal plan include parametric monitoring requirements for good
combustion at 40 CFR 62.15960. The commenter points out that a
definition of ``combustion chamber'' is not provided in 40 CFR
62.16045, though the definition for ``fluidized bed incinerator'' makes
mention of ``combustion chamber.'' A multiple hearth incinerator
typically includes drying, combustion and cooling zones and could also
include an afterburner for carbon monoxide removal. The commenter
believes that it is unclear whether the requirement under 40 CFR
62.15960 to establish a minimum operating temperature applies to (a)
the combustion chamber within a fluidized bed incinerator and the
afterburner in a multiple hearth incinerator only, or (b) to all
hearths/zones within a multiple hearth incinerator as well as (a), or
(c) to only the combustion zone within a multiple hearth incinerator as
well as (a), or (d) does not apply at all to any of the hearths/zones
within a multiple hearth incinerator. The commenter stresses the
importance of developing site-monitoring plans for temperature sensors
that are affected under 40 CFR 62.15995(a)(3)(ii)(D).
    Response: The SSI federal plan does not define the term
``combustion chamber.'' In response to the comment regarding where the
minimum combustion temperature is applied, we are clarifying that the
minimum combustion temperature is to be applied in the combustion zone
of the unit. The drying hearth or zone temperature typically ranges
between 800 and 1,400 degrees Fahrenheit. In the drying zone, the
sludge that is dried is heated so that efficient combustion may then
occur. We do not believe it is appropriate to establish minimum
combustion temperature in the drying zone because the drying zone's
purpose is to reduce the moisture and heat up the sludge, not to
combust the sludge. The temperature of the combustion zone is typically
1,700 degrees Fahrenheit. Combustion typically requires at least
greater than 1400 degrees Fahrenheit to destroy solids and fixed
carbon. We intend for the minimum combustion temperature to be applied
in the combustion zone in order for good combustion to occur. From the
combustion zone, the cooling zone occurs next where ash cools and heat
is transferred to the incoming combustion air. The cooling zone also
would not be appropriate to apply the minimum combustion temperature
because combustion should have completed by this point.
    Comment: One commenter (12) states that they have had numerous
discussions with the EPA about the EG and proposed federal plan's
requirement relating to fugitive visible emissions from ash handling.
They identify that other Maximum Achievable Control Technology
standards specifically state that this requirement applies to emissions
from the building to the atmosphere, not from equipment within the
incinerator building, and EPA has confirmed in phone conversations with
the commenter that the same is true for the visible emissions
requirements for ash handling in the EG and proposed federal plan. The
commenter requests that this be clearly stated in the final federal
plan. The commenter believes that any attempt to apply the fugitive ash
requirement within the incinerator building would be unjustified and
lead to major compliance issues.
    Response: The underlying emissions guideline is clear that the
requirement applies to fugitive visible emissions from the ash handling
system. The definition of an SSI unit at 40 CFR 62.16045 describes that
the unit includes all ash handling systems

connected to the bottom ash handling system and that the combustion
unit bottom ash system ends at the truck loading station or similar
equipment that transfers the ash to final disposal. Tables 2 and 3 of
the federal plan regulatory text further specify that the visible
emissions of combustion ash from an ash conveying system include
conveyor transfer points. It is not predicated on the location of the
ash handling system. The 2011 EG and NSPS response to public comments
also explains that the rule should and does require that the source
owner or operator verify that the measures necessary to limit the
amount of fugitive dust exiting the transfer points and exhausts from
the building are such that they meet the visible emissions
standard.\16\ The commenter did not provide any specifics as to why the
emission standard for fugitive emissions from ash handling is
unjustified or would lead to major compliance issues.
---------------------------------------------------------------------------

    \16\ See Docket Identification Number EPA-HQ-OAR-2009-0559-0171.
---------------------------------------------------------------------------

    Comment: One commenter (12) states that according to the EG and the
proposed federal plan, all of the operating parameters, with the
exception of scrubber water pH, are to be equal to the lowest 4-hour
average measured during the most recent compliance test. The commenter
states that EPA staff have indicated that when writing the EG, EPA
personnel assumed that each of the three required test runs would be 4
hours in duration. However, the EPA included air emission test
protocols in the final rule for performance testing that allow three 1-
hour test runs. During correspondence with EPA, the commenter states
that EPA staff agreed that 1-hour test runs were acceptable for
establishing operating parameters. Furthermore, the EPA agreed that the
lowest 4-hour average should be deleted and replaced with the 1-hour
test run average already agreed to in principle. The commenter asks the
EPA to confirm this in writing in the final federal plan and through
the appropriate process to update any state implementation plans, as
well in 40 CFR part 60, subpart LLLL (NSPS for SSI units).
    Response: The EPA notes that the regulation requires a minimum
overall sample volume for each test run, not a minimum sample time. It
is possible that some performance tests for PM and metals may not
require 4 hours in total to achieve the minimum sample volume for the
three runs. However, because the operating parameters must be set based
on a 4-hour average from the performance test, the EPA has concluded
that it is necessary to test for at least 4 hours (in total, not per
run), even if this means collecting more than the minimum sample volume
prescribed in the rule.
    Comment: One commenter (12) recognizes that numerous SSI unit
owners and operators have raised questions regarding setting and
implementing operating limits. The commenter provides the following
example: During a recent performance test at one facility to establish
venturi water flow rate, when the flow rate was recorded at 344 gpm.
The commenter asks whether the utility must set the flow rate at the
level or whether it can set the flow rate at 340 gpm. The commenter
states that SSI unit owners and operators are not familiar with these
provisions and would benefit from any additional guidance the EPA can
provide. The commenter states that some leeway makes sense due to
measurement variability. The commenter believes that compliance with
the parametric limit should be based on the average high/low value (as
appropriate) plus or minus 30-percent, consistent with the existing 40
CFR part 60, subpart O requirements. The commenter requests that the
EPA clarify how averages are to be calculated. They state that
utilities need to know how the x-hour averages are calculated for each
operating parameter. Scrubber flow rate, liquid pH, combustion chamber
operating temperature, etc. limits all depend of knowing how this
calculation must be performed.
    Response: The rule provides sufficient flexibility to owners and
operators to establish monitoring parameters that are achievable on an
on-going basis. The owner and operator also has the flexibility to
conduct repeat performance tests to re-establish performance tests
parameters.
    While 40 CFR part 60, subpart MMMM, do not provide for the plus or
minus 30-percent allowance that is in 40 CFR part 60, subpart O, the
EPA notes that the operating parameter averaging times in subpart MMMM
are much longer than the averaging times in subpart O. This is meant to
account for the short-term fluctuations in the operating parameter
readings and serves a similar purpose to the 30-percent allowance. The
EPA does not think that providing the 30-percent allowance on top of
the long averaging times is appropriate for ensuring continuous
compliance.
    Section 62.15985 of 40 CFR part 62 describes how operating limits
are established and Table 4 of the federal plan regulatory text
describes how to demonstrate compliance with operating parameters
limits. For example, minimum combustion chamber temperature is equal to
the lowest 4-hour average combustion chamber temperature during the
performance test. This is likely the combustion chamber measured over
one test run, as the test run for dioxins and furans is likely to last
around 4 hours. If this 4-hour average is 1,802 degrees Fahrenheit, the
limit is 1,802 degrees Fahrenheit, not 1,800 degrees Fahrenheit. On a
continuous basis, the combustion temperature would be measured and
recorded at least once every 15 minutes, and those data would be used
to calculate hourly arithmetic averages. The hourly average would then
be used to calculate a 12-hour block average. The 12-hour block average
would be compared to the lowest 4-hour average recorded during the test
(1,802 degrees Fahrenheit in this example) to determine compliance.
Compliance with the other operating parameter limits are demonstrated
similarly according to the specific timeframes noted in 40 CFR 62.15985
and Table 4 for each operating parameter.
    Comment: One commenter (12) requests that the EPA considers
building some measure of flexibility into the site-specific operating
limits. Specifically, the commenter suggests that the enforceable site-
specific operating limit could be higher or lower than the limit
established during the compliance tests within some defined boundaries.
The commenter provides an example: If the lowest total pressure drop
during the testing is 40 inches and the particulate matter and the
metal emissions rates are all at or below 75-percent of the
standards,\17\ is EPA willing to reduce the total pressure drop
operating limit to 36 inches? The commenter believes that the EPA has
allowed this type of flexibility in its 40 CFR part 60, subpart O, and
40 CFR part 503 requirements.
---------------------------------------------------------------------------

    \17\ The commenter acknowledges that the EG does allow for
reduced frequency of testing for pollutants that are at or below 75-
percent of the emissions limits for at least two consecutive years.
---------------------------------------------------------------------------

    Response: This comment is outside the scope of this action, since
EPA is adopting a federal plan that simply implements the underlying
requirements of the EG. The EPA thanks the commenters for their
valuable feedback and ideas. We will consider making changes to the EG
and federal plan to incorporate the suggested revisions in the future.
If a particular operating parameter is inappropriate for a site-
specific configuration, under 40 CFR 62.16050, 40 CFR 60.8 and 60.13
the facility may submit an alternative

monitoring plan to the appropriate EPA regional office.
    Comment: One commenter (12) states that SSI unit owners and
operators are concerned they will be required to meet the emissions
limits required by the federal plan and the operating parameters
immediately after the initial compliance test. Based on conversations
with EPA regional staff, the commenter understands that, as long as an
SSI unit continues to operate as specified in an existing title V
permit or other authorizing document (where there is no title V
permit), they are not required to operate the control equipment under
the established parameters of the rule's initial compliance test until
the compliance date of March 21, 2016 (or earlier date specified by a
state implementation plan). The commenter asks the EPA to confirm this
in writing.
    Response: The EPA reiterates that the final compliance date of the
federal plan in March 21, 2016. SSI units will need to be in compliance
by that date, including operating within the limits of the operating
parameters they establish during the initial performance test.
Compliance before the compliance date is encouraged but not required.
SSI units subject to state plans may be required to meet earlier
compliance dates. The EPA notes that SSI units must also comply with
the requirements in their title V operating permits.
    Comment: One commenter (16) states that proposed 40 CFR 62.16015
implies that the use of the bypass stack when sewage sludge is not
being charged is not an emission standard deviation. Section 62.16015
of 40 CFR part 62 states that use of the bypass stack at any time that
sewage sludge is being charged to the SSI unit is an emissions
standards deviation for all pollutants listed in Table 2 or 3 of the
subpart. The commenter asks the EPA if this interpretation is correct.
Similarly, the commenter states that proposed 40 CFR 62.15955 implies
that emissions limits and standards do not apply to a bypass stack or
vent if sewage sludge is not being combusted. Section 62.15955 of 40
CFR part 62 states that emissions limits and standards apply at all
times the unit is operating and during periods of malfunction. The
emission limits and standards apply to emissions from a bypass stack or
vent while sewage sludge is in the combustion chamber (i.e., until the
sewage sludge feed to the combustor has been cut off for a period of
time not less than the sewage sludge incineration residence time). The
commenter asks EPA if their interpretation is correct.
    The commenter (16) further identified that 40 CFR 62.15970 appears
to conflict with 40 CFR 62.15955. Section 62.15970 of 40 CFR part 62
reads, ``emission limits and standards apply at all times and during
period of malfunction.'' Section 62.15955 of 40 CFR part 62 includes
the proviso ``at all times the unit is operating.'' The commenter
interprets the statement, ``at all times'' as written in 40 CFR
62.15970 to conflict with the implication in 40 CFR 62.15955 that
emissions limits and standards apply to a bypass stack while sewage
sludge is in the combustion chamber. The commenter points out that the
term ``operating'' as used in the proposed federal plan is not defined.
The commenter asks the EPA to clarify if the term ``operating'' is the
period of time when sludge is being combusted in the incinerator, or is
the term to mean any period of time that burners are on in the
incinerator, regardless of whether or not sludge is being combusted.
The commenter also points out that the term ``operating limits'' is
used in the regulations, but the definition of ``operating'' is not
clearly defined.
    Similarly, the commenter cites a discussion at 80 FR 23411, which
states that ``any incident of deviation, resumed operation following
shutdown, force majeure . . . are required to be reported to the
Administrator.'' The commenter reiterates that the term ``shut-down''
is defined as ``the period of time after all sewage sludge has been
combusted in the primary chamber.'' The commenter explains that it is
common practice for an SSI facility to run out of sludge to incinerate,
and is therefore ``shutdown'' on a regular basis, either weekly or
possibly more frequently until they have enough sludge to incinerate.
The commenter asks the EPA to clarify whether this discussion in the
preamble of the federal plan proposal means that each time an SSI
facility runs out of sludge and/or temporarily shuts off the sludge
feed to the incinerator for operational reasons, and then resumes
burning sludge, the Administrator must be notified. The commenter
asserts that ``shutdown'' by definition can exist with the burners on
but with no sludge being combusted. The commenters interprets that this
could mean that the term ``operation'' should be defined as any time
sludge is being combusted in the incinerator.
    The commenter further states that 40 CFR 62.15970 conflicts with
their understanding that, during the time when sludge is not being
combusted in the incinerator, it is not a deviation if the natural
draft damper is open. Section 62.15970 of 40 CFR part 62 states that
for determining compliance with the carbon monoxide (CO) concentration
limit using CO CEMS, the correction to 7-percent oxygen does not apply
during periods of startup or shutdown. Use the measured CO
concentration without correcting for oxygen concentration in averaging
with other CO concentrations (corrected to 7-percent oxygen) to
determine the 24-hour average value. The commenter explains that CEMS
obtain samples from the main incinerator stack, after pollution control
equipment. The CEMS does not sample from the natural draft stack,
therefore while the natural draft stack is open the CEMS is in essence
sampling ambient air and therefore inclusion of the CO concentrations
during these times seems irrelevant. The commenter states that CO is
still required to be monitored when sludge is not being combusted in
the incinerator during a period of shutdown. The commenter asks EPA to
clarify why, if emission limits do not apply when sludge is not being
combusted, CO must continue to be monitored, which requires the
constant operation of a scrubber, a WESP, and an afterburner to obtain
a valid CO reading.
    Response: The language in 40 CFR 62.16015 is clear in specifying
that use of the bypass stack when sewage sludge is charged is a
deviation of the standards. Section 62.15955 of 40 CFR part 62 also
clearly states that the emission limits and standards apply to
emissions from a bypass stack or vent while sewage sludge is in the
combustion chamber. EPA disagrees with the commenter that 40 CFR
62.15970 conflicts with 40 CFR 62.15955. The emissions standards apply
at all times. While we would expect that the source could meet the
emissions limit when not charging sludge (e.g., when burning a fuel
such as natural gas), that is not a given. Therefore, we did not
provide specific rule language for the use of the stack bypass when
sewage sludge is not being charged as the ``flip'' side to the
requirement at 40 CFR 62.16015 and 40 CFR 62.15955.
    Defining terms in the federal plan that are not defined in the
underlying EG is beyond the scope of this rulemaking. CAA section 129
clearly directs the EPA to structure the rule to include monitoring
provisions of parameters relating to the operation of the unit and its
pollution control equipment. Furthermore, we believe that the term
``operating limit'' is sufficiently understood by the regulated
community. The EPA points out that the federal plan does define the
term ``operating day'' to mean a 24-hour period between 12:00 midnight
and the following midnight during which any

amount of sewage sludge is combusted at any time in the SSI unit.\18\
---------------------------------------------------------------------------

    \18\ See 40 CFR 62.16045.
---------------------------------------------------------------------------

    Regarding the differing language ``at all times when the unit is
operating'' in 40 CFR 62.15955 and the language ``at all times'' in 40
CFR 62.15970, we do not believe that the underlying EG intended any
significance to this difference. As discussed in the preamble to that
rule, we are clear that the emissions limits and standards apply at all
times (see 75 FR 63265 and 75 FR 63282).
    The EPA is finalizing the notification requirements as proposed to
require that sources notify the Administrator following any incident of
deviation, force majeure, intent to stop or start use of CMS, and
intent of conducting or rescheduling a performance test. EPA clarifies
that notification of resumed operation following shutdown as cited by
the commenter at 80 FR 23411 is clear in the rule text. Specifically,
the notification of resumed operation following shutdown of the unit is
in the context of a qualified operator deviation. See 40 CFR
62.15945(b)(i) and (ii), 40 CFR 62.16030(e), and table 6 in the rule.
Please note that the rule requires other notifications associated with
a unit ceasing operations or going ``offline''.\19\
---------------------------------------------------------------------------

    \19\ For a full list of notification requirements, please see
Table 6 of 40 CFR part 62, supart LLL.
---------------------------------------------------------------------------

    Lastly, 40 CFR 62.15970 clearly states that operating limits only
apply when sludge is being combusted including residence time, but the
emission limits apply at all times. The definition of bypass stack
indicates that the bypass stack's intended purpose is to avoid severe
damage to air pollution control devices or other equipment.\20\ The EPA
did not intend for facilities to use the bypass stack at all times when
there is no sewage sludge being burned. Therefore, emissions should
generally be routed to the main stack even during periods when sewage
sludge is not being burned, and the requirement to continue monitoring
the emissions with the CO CEMS is relevant, as compliance with the
emission standard is still required during these periods.
---------------------------------------------------------------------------

    \20\ Comments received on the 2011 EG and NSPS indicate that
bypass stacks are an essential part of the safety equipment and use
of the stack indicates that the unit is not operating under normal
conditions. See Docket Identification Number EPA-HQ-OAR-2009-0559-
0171.
---------------------------------------------------------------------------

    Comment: One commenter (16) asks the EPA to clarify if 40 CFR
62.16020 includes periods of time when sludge is not being combusted in
the incinerator. Section 62.16020 of 40 CFR part 62 states that if your
SSI unit has a bypass stack, you must install, calibrate (to
manufacturers' specifications), maintain and operate a device or method
for measuring the use of the bypass stack including date, time, and
duration. The commenter explains that it is common practice for SSIs to
open the bypass stack and ``coast'' on natural draft during periods
when sludge is not being combusted in the incinerator in order to save
fuel, electricity, and wear and tear on equipment. The commenter,
referencing their comment that they interpret 40 CFR 62.16015 to imply
that the use of the bypass damper when sludge is not being combusted in
the incinerator is not a deviation, asks whether the recordkeeping and
reporting requirements of 40 CFR 62.16020 do not apply while not
combusting sludge in the incinerator.
    Response: The rule is clear as written. The requirement to install,
calibrate, maintain and operate a device or method for measuring the
use of the bypass stack including date, time and duration applies when
sludge is combusted and when sludge is not combusted.
    Comment: One commenter (16) asks the EPA to clarify if 40 CFR
62.16015 is to be interpreted to mean that each daily calibration
check, zero and span adjustments, and quarterly and annual calibrations
must be reported in a deviation report. Section 62.16015 of 40 CFR part
62 states that any data collected during monitoring system
malfunctions, repairs, or required monitoring system quality assurance
or control activities must be reported in a deviation report.
    Response: As the commenter notes, periods of equipment malfunction,
repairs and out-of-control periods are to be reported as deviations.
While we do not intend all instances of required quality assurance and
quality control activities to be reported as deviations, to the extent
that ongoing quality assurance and quality control activities require
an amount of time such that an hourly average cannot be determined for
that hour consistent with the requirements given in 40 CFR
60.13(h)(2)(iii) (i.e., there are not enough data collected during the
hour), those periods should also be reported as deviations. Reporting
of such periods informs regulatory authorities when unusual
circumstances occur, allowing increased scrutiny as necessary.
    Comment: One commenter (16) asks that the EPA clarify how 40 CFR
62.15985 should be interpreted. Section 62.15985 of 40 CFR part 62
states that we must perform checks at least once each process operating
day to ensure pressure measurements are not obstructed (e.g., check for
pressure tap plugging daily). The commenter explains that their
pressure transducers and transmitters operate with a 4 to 20 milliamp
signal sent to a controller that monitors the pressure reading and
controls the equipment necessary to maintain the operating setpoint.
Disconnection of the transducer to check ``the tap'' causes the signal
from the transmitter to send incorrect milliamp signals back to the
controller, which in turn can cause the controller to erroneously
control the equipment, or, in a worst case scenario, to trigger safety
shut-offs of the incinerator itself.
    Response: In general, we are not specifying how performance
evaluations are to be performed. Due to the many variations in
monitoring equipment, the manufacturer of the equipment is the best
source for determining the proper technique for performing most
performance evaluations. The site-specific monitoring plan must include
information on routine quality assurance and quality control
procedures. The plan should include not only a schedule for performing
the performance evaluations, but also a description of how the
evaluations will be performed. Unless specified, the EPA is providing
the facility with discretion to determine the best method to perform
these evaluations for these site-specific monitoring systems. The
facility, in conjunction with the equipment manufacturer, should
determine the best manner for demonstrating that the pressure
measurements are not obstructed. One example of such a procedure,
checking for pressure tap pluggage, is provided, but it is not the only
possible option.
    Comment: One commenter (16) asks that EPA clarify how 40 CFR
62.15990 should be interpreted. Section 62.15990 of 40 CFR part 62
requires that a ``performance evaluation'' of a pH meter be performed
daily. The commenter explains that companies that provide in-line
continuous pH meters are not aware of any feature other than a
calibration to demonstrate the accuracy of the meter, and calibrations
are only required quarterly. The commenter points out that different
regulators may consider the term ``performance evaluation''
differently, and may in fact consider a calibration as the only good
method to determine the performance of the meter, which is not
reasonable to do on a daily basis.
    Response: In general, we are not specifying how performance
evaluations are to be performed. Due to the many variations in
monitoring equipment, the EPA believes that the manufacturer of the
equipment is the best source for determining the proper technique for

performing most performance evaluations. The site-specific monitoring
plan must include information on routine quality assurance and quality
control procedures. The plan should include not only a schedule for
performing the performance evaluations, but also a description of how
the evaluations will be performed. Unless specified, the EPA is
providing the facility with discretion to determine the best method to
perform these evaluations for these site-specific monitoring systems.
    A performance evaluation and a calibration are not meant to be the
same thing, although a calibration could certainly suffice in lieu of a
performance evaluation. The intent of a performance evaluation is to
demonstrate that the equipment is still functioning within a specific
degree of accuracy. It is akin to performing a calibration check of a
CEMS in lieu of performing a CEMS calibration; in the former, the
facility would merely show that the CEMS is still within a certain
accuracy of a known standard, but the CEMS would not be adjusted in any
way. The EPA has not provided specific examples of a pH meter
performance evaluation, but one such example is performing a one-point
check on a known buffer solution. The facility, in conjunction with the
equipment manufacturer should determine the best manner for
demonstrating that the pH meter is reading accurately each day.
    Comment: One commenter (16) discusses their overall operations.
Their MH unit has been in operation since 1994 and the air pollution
control devices include a venturi scrubber, a plate scrubber, a WESP,
and a regenerative thermal oxidizer (afterburner). Their standard
operating procedure is to initiate the combustion of sludge on Monday,
with continuous combustion until Saturday or Sunday depending on the
amount of sludge inventory. Once they run out of sludge, charging of
sludge to the incinerator is stopped, and the temperature of the SSI
unit is stabilized to what they consider to be a cool standby condition
(hearth number 3 is at 1,100 degrees Fahrenheit). Approximately 4 hours
after the sludge feed is stopped, well past the residence time of
sludge in the incinerator, the induced draft fan is shut off and the
natural draft damper opens. Monday is then used for preventative
maintenance or other work on the unit and pollution control equipment.
During the time when the SSI unit is on natural draft, the scrubber,
WESP, and afterburner are off-line. This allows the commenter the
flexibility of shutting off the WESP and/or the afterburner. Late on
Monday, SSI unit temperatures are raised to 1,350 degrees Fahrenheit in
preparation of again burning sludge, and the induced draft fan is re-
started, placing the scrubber, WESP, and the afterburner back on-line.
Then sludge feed to the unit is initiated. This process occurs weekly,
possibly more often if unexpected maintenance on any of the SSI unit
equipment or pollution control equipment becomes necessary.
    The commenter states that the proposed federal plan appears to
imply that now any SSI unit owner or operator can never shut the
induced draft fan off and coast the incinerator in a cool standby
condition with the natural draft damper open even if sludge is not
being combusted in the SSI. The commenter believes that this is implied
because SSI unit owners and operators are directed to average CO at 7-
percent oxygen while combusting sludge and with CO while not combusting
sludge, to obtain the 24-hour CO average. CO monitoring probes,
however, are only installed on the induced draft fan stack, not on the
natural draft stack, so in order to obtain the ``average'' CO reading,
the induced draft fan has to be on-line at all times. Further, the
commenter believes it is implied that if the induced draft fan is shut
off (even when not combusting sludge), this is a reportable deviation
that could subject the facility to enforcement action. The commenter
further describes that any facility has to be able to shut off the
induced draft fan for preventative maintenance, for other scheduled
maintenance, and to save fuel without having it considered a deviation
or violation. Additionally, the commenter states that it is not
practical to run the induced draft fan when first turning on the
burners (start-up) after a cold shutdown. The induced draft fan is not
sized for cold air, and the temperatures inside the MH incinerator must
be raised slowly, in most cases not more than 50 degrees per hour with
several extended periods of ``soak'' that are intended to protect the
refractory and brick. Running the induced draft fan during ``start-up''
from a cold start requires more fuel and requires electricity, and
makes it difficult to properly raise temperatures to the proper burning
range. However, 40 CFR 62.15970 implies that CO readings must be
obtained at all times after start-up, not just when combusting sludge
in the SSI. In order to do this, the induced draft fan must be turned
on before the burners are even lit.
    Response: Section 62.15970 of 40 CFR part 62 clearly states the
emission limits apply at all times. The definition of bypass stack
indicates that the bypass stack's intended purpose is to avoid severe
damage to air pollution control devices or other equipment.\21\ As the
commenter infers from the CO CEMS language, the EPA did not intend for
facilities to use the bypass stack at all times when there is no sewage
sludge being burned, and emissions should generally be routed to the
main stack even during periods when sewage sludge is not being burned,
except in cases when it is necessary to route emissions to the bypass
in order to avoid damage to equipment.
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    \21\ Comments received on the 2011 EG and NSPS indicate that
bypass stacks are an essential part of the safety equipment and use
of the stack indicates that the unit is not operating under normal
conditions. See Docket Identification Number EPA-HQ-OAR-2009-0559-
0171.
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4. Status of State Plans and Federal Plan Delegation
    Comment: Multiple commenters (09, 10, 12, 15) request that the EPA
update the status of state plans in Table 2 of this preamble. One
commenter (09) confirmed that the Minnesota Pollution Control Agency
will not be submitting a state plan to the EPA but instead plans to
incorporate federal plan requirements into the affected SSI's title V
permits once the federal plan is promulgated. One commenter (10)
requests that the EPA reflect that the state of Rhode Island submitted
a draft state plan to the EPA on October 10, 2014. One commenter (12)
identified the state of Virginia as having received EPA approval of its
state plan. Another commenter (15) clarifies that they intend to seek
delegation of the federal plan for SSI units.
    Response: The EPA thanks the commenters for submitting these
updates and corrections. We have reflected these changes in the record
to this final federal plan and in Table 2, which is included in section
II.C. of this preamble.
    Comment: Commenters (09, 11, 12, 15) request that the EPA clarify
the implementation roles for ``states,'' ``locals,'' and the EPA with
respect to the implementation of the EG. One commenter (12) believes
that the lack of clarity is particularly an issue in those states where
there are both state and local air agencies, but the states have not
yet developed a state plan. The commenter requests that the EPA
continue to work with state and local regulators to address these
concerns. Commenter (11) further outlines that the proposed federal
plan does not clearly discuss how the authority to implement the
federal plan will be transferred to local air agencies, especially if a
state decides not to develop a state plan or further adopt or implement
the federal

plan. The commenter states that Washington state, where five
municipalities operate SSI units, has not expressed a decision to
submit a draft state plan to the EPA or take delegation of the federal
plan. The commenter is concerned with the outcome of how the three
local agencies affected will manage the implementation of the EG. The
commenter urges the EPA to work directly and closely with local air
agencies in order to clearly and effectively provide authority and
technical guidance to SSI unit operators. The commenter believes that
such authority should extend to local agencies so they can use their
discretion to work with SSI unit operators in determining appropriate
final compliance dates as proposed in 40 CFR 62.15875. Another
commenter (15) states that they are a local air authority in Washington
state that has an approved title V program and has received regular
delegation approvals for NSPS and NESHAP regulations (40 CFR part 60
and 63). Their most recent delegation approval from EPA Region 10 was
signed on February 19, 2015, for the NSPS for new SSI units at 40 CFR
part 60, subpart LLLL. The commenter states that the local agency
intends to seek delegation of the federal plan as soon as possible.
This local air agency plans to expedite their request for delegation
following the final federal plan instructions so that they can address
the regulatory gap in the title V permits for units in their district.
    Response: The EPA is finalizing the delegations of authority
provisions as proposed, and clarifying that local agencies may directly
request delegation of authority to implement the SSI federal plan with
respect to sources within their jurisdiction provided they have
authority under state law to do so. While the preamble to the proposal
does not specifically address how to address the situation where there
are both state and local air agencies and the state has not yet
developed a state plan, the EPA stated that it will do all that it can
to expedite delegation of the federal plan to state and local agencies
in those situations. However, since this involves resolution of issues
of state authority, the EPA expects that local agencies will work with
their states and the appropriate EPA regional office to resolve these
issues affecting their ability to implement the EG under a state plan
or delegated federal plan for the area. See 40 CFR 60.26(e). In the
meantime, a state or tribe with an approved title V program with
authority under state or tribal law to incorporate CAA section 111/129
requirements into its title V permits is able to implement and enforce
these requirements in the permitting context. See 80 FR 23413.
    As the EPA discussed in the proposed federal plan the EG are not
directly enforceable; they are only fully implemented when the EPA
either approves a state plan or adopts a federal plan that implements
and enforces the EG.\22\ Congress has determined that the primary
responsibility for air pollution prevention and control rests with
state and local agencies. (See section 101(a)(3) of the CAA.)
Consistent with that overall determination, Congress established
sections 111 and 129 of the CAA with the intent that the state and
local agencies take the primary responsibility for ensuring that the
emissions limitation and other requirements in the EG are achieved.
Also, in section 111(d) of the CAA, Congress explicitly required that
the EPA establish procedures that for state CAA section 111(d) plans
that are similar to those under CAA section 110(c) for state
implementation plans. Although Congress required the EPA to propose and
promulgate a federal plan for states that fail to submit approvable
state plans on time, states may submit plans after promulgation of the
SSI federal plan.
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    \22\ See the discussion beginning on 80 FR 23411.
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    The EPA directs states, tribes, and locals that intend to take
delegation of the federal plan to submit to the appropriate EPA
regional office a written request for delegation of authority.\23\ The
requester must explain how they meet the criteria for delegation. The
EPA references the ``Good Practices Manual for Delegation of NSPS and
NESHAP'' (EPA, February 1983) as a guidance document for states,
tribes, and locals to follow. The EPA clearly describes two mechanisms
for transferring authority to state, tribal, and local agencies: (1)
EPA approval of a state plan after the federal plan is in effect, and
(2) if a state does not submit or obtain approval of its own plan, the
EPA delegation of authority to a state, tribal, or local agency to
implement certain portions of the federal plan to the extent
appropriate and allowed by law. The EPA will generally delegate the
entire federal plan to the requesting agency. These functions include
administration and oversight of compliance reporting and record keeping
requirements, SSI inspections and preparation of draft notices of
violation, but will not include authorities retained by the EPA.
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    \23\ See 40 CFR 62.15865 and 40 CFR 62.16050.
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    Agencies that have taken delegation, as well as the EPA, will have
responsibility for bringing enforcement actions against sources
violating federal plan provisions. Specifically, the proposed federal
plan requires that an acceptable delegation request must include the
following: a demonstration of adequate resources and legal authority to
administer and enforce the federal plan (e.g., attorney general's
(AG's) opinion \24\); an inventory of affected SSI units and their air
emissions in addition to their compliance schedules; certification and
documentation that a public hearing on the delegation request was held;
and a commitment to enter into a memorandum of agreement with the EPA
Regional Administrator who sets forth the terms, conditions, and
effective date of delegation and that serves as the mechanism for the
transfer of authority.\25\
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    \24\ A state's AG's opinion that its air agency has the
authority to receive delegation and demonstrate that the rule will
be implemented and enforced relative to the designated facilities.
If an AG's opinion was previously submitted, the opinion should be
updated by the attorney general at the time a new delegation request
is submitted to the EPA. The AG's opinion will be crucial because
promulgated EG are not written as direct requirements for designated
facilities, but rather as requirements for the state to ensure that
its state plan or delegation request contains enforceable
regulations that are at least as protective as those in the EG. See
40 CFR 60.26 and 40 CFR 62.05 for all provisions that should be
addressed in an AG's opinion.
    \25\ Guidance and information is provided in EPA's ``Delegations
Manual, Item 7-139, Implementation and Enforcement of 111(d)(2) and
111(d)(2)/129(b)(3) Federal Plans.''
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    Neither the SSI EG nor the proposed federal plan define ``state.''
``State'' is defined in 40 CFR 60.2, however, to mean all non-Federal
authorities, including local agencies, interstate associations, and
state-wide programs, that have delegated authority to implement: (1)
the provisions of the part; and/or (2) the permit program established
under part 70 of the chapter. The term state shall have its
conventional meaning where clear from the context. Because ``state'' is
not defined in either the SSI EG or proposed federal plan, the broader
definition of ``state'' in 40 CFR 60.2 applies in the SSI federal plan.
This is because, as provided in 40 CFR 62.01, all terms not defined
therein have the meaning given to them in the CAA and in part 60 of the
chapter. Based on the lack of a more specific definition of ``state''
in the SSI federal plan and the definition of ``state'' in 40 CFR part
60, we are confirming here that local agencies may directly request
delegation of authority to implement the SSI federal plan with respect
to sources within their jurisdiction provided they have

authority under state law to do so and they have met all the
requirements specified in the federal plan for taking delegation. This
is in contrast to the situation with state plans implementing EG, in
which we believe the request for plan approval must be submitted by the
state.\26\
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    \26\ See CAA section 110(a)(2)(e) and CAA section 111(d).
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    The EPA strongly encourages state and local agencies in states that
do not submit approvable state plans to request delegation of the
federal plan so that they can have primary responsibility for
implementing the EG, consistent with the intent of Congress. Approved
and effective state plans or delegation of the federal plan is the
EPA's preferred outcome because states, tribes, territories, and local
agencies not only have the responsibility to carry out the EG, but also
have the practical knowledge and enforcement resources critical to
achieving the highest rate of compliance. It is generally preferable
for state and local agencies to be the implementing agencies. The EPA
reiterates that we will do all that we can to expedite delegation of
the federal plan to state and local agencies, whenever possible, in
cases where states are unable to develop and submit approvable state
plans.
    Comment: One commenter (12) raises concerns regarding the EPA's
delay of proposing the federal plan. The commenter specifically states
that the delay has exacerbated the difficulties SSI unit owners and
operators have faced in implementing the EG, especially given the fact
that a majority of states have not chosen to develop their own state
plans. The commenter encourages the EPA to move expeditiously to
finalize the federal plan.
    Response: The EPA acknowledges this comment.
5. Inventory of Units
    Comment: One commenter (09) confirms that the EPA has properly
identified the two SSI facilities in Minnesota that will be subject to
this SSI federal plan. Both facilities are owned and operated by
Metropolitan Council Environmental Services, the regional wastewater
treatment system operator for the Twin Cities area.
    Response: The EPA thanks the commenter for confirming the accuracy
of the unit inventory for units in their state.
6. Remand
    Comment: Two commenters (11, 12) raise concerns that the EPA has
not yet addressed the remand in the Court Decision NACWA v. EPA.
Specifically, commenter (11) believes that the proposed federal plan is
ambiguous and confusing and they are in an untenable position to
comply. The commenter highlights that this is because of the EPA's
delay of issuing the federal plan, issuing associated policy and
guidance directives for implementation of the rule, and the EPA's
decision to not yet address the remand in the DC Circuit Court decision
NACWA v. EPA, 734 F.3d. 1115. Commenter (12) believes that the EPA must
address both the issues raised in its May 29, 2014, Petition for
Reconsideration and the rule remand in the DC Circuit Court August 2013
decision in NACWA v. EPA, 734 F.3d. 1115. The commenter states that it
is inappropriate to issue a final federal plan in the absence of the
EPA's response to the remand. The commenter believes that the EPA's
failure to address the remand puts approximately 100 utilities in an
untenable position: Facilities must commit millions of dollars to
upgrade their SSI units to comply with emissions standards that the
Court has ruled do not clearly meet CAA statutory mandates. The
commenter discusses that they outlined further details in their 2014
Petition for Reconsideration that the EPA must either fully address the
Court's remand and adjust the final emissions standards as warranted or
delay the compliance deadline for the rule to prevent this potentially
wasteful expense of taxpayer dollars.
    Response: The EPA disagrees that issuance of the federal plan must
be delayed until such time as we address the Court's remand of certain
issues in NACWA v. EPA. The Court's remand was solely for the purpose
of further explanation of the EPA's methodology. Contrary to one
commenter's assertion, the Court did not find that the SSI rule was
inconsistent with the CAA. Rather, the Court requested that the EPA
better explain how its methodology meets the relevant statutory
requirements. Further, the same commenter, which was a party in the
NACWA case, requested that the Court vacate the SSI rule, and the Court
declined to do so. Therefore, the Court understood and intended that
the rule remain in place and that its implementation should move
forward while the EPA responds to the remand. For this reason, the EPA
also disagrees with the commenter who claimed that the SSI rule
requirements are ``not even established requirements,'' since they
remain in place.
    The EPA also disagrees that the agency must respond to one
commenter's 2014 petition for Reconsideration of the SSI rule,
submitted following the NACWA decision, before issuing the federal
plan. Nothing in the CAA, and specifically nothing in CAA section 129,
suggests that the EPA should postpone promulgation of a rule required
to be issued by the CAA by a date certain in order to address a
petition for reconsideration. Nor does the commenter point to any such
authority. Additionally, the petition at issue requests that the EPA
withdraw the SSI rule and instead issue a different rule for SSI units
under section 112 of the CAA. The EPA notes that the NACWA decision
upheld our authority to regulate SSI units under CAA section 129,
against a challenge claiming that the EPA must regulate the units under
CAA section 112.
7. Other Comments
    Comment: One commenter (14) remarks on the interaction of the SSI
federal plan and 40 CFR part 503, subpart E. The commenter asks if the
federal plan for SSI units will establish different operating limits
and reporting requirements that may be different than those established
under the Clean Water Act at 40 CFR part 503, subpart E. The commenter
requests that the EPA consider a streamlined approach to facilitate a
single set of operational parameters for demonstrating compliance.
    Response: This comment is outside the scope of the SSI federal
plan. However, the EPA discusses the relationship of the rule to other
standards for the use or disposal of sewage sludge and associated air
emissions in preamble of the March 21, 2011, EG and NSPS for SSI units
at 76 FR 15375.
    Comment: One commenter (12) discusses that some SSI units are
subject to the standard for particulate matter under 40 CFR part 60,
subpart O, which establishes emissions limits, monitoring requirements,
and recordkeeping requirements that are different than the guidelines
and standards for SSI units under 40 CFR part 60, subparts MMMM and
LLLL. The commenter gives the example of the requirement for pressure
drop, which is different between subpart O and subparts MMMM and LLLL.
Specifically, subpart O pressure drop is a 15-minute average while
subpart LLLL is a 12-hour average. The commenter is aware of at least
one facility that has submitted a request to the EPA to allow the
utility to demonstrate compliance with subpart O by demonstrating
compliance with subpart LLLL or MMMM. The commenter asks that the EPA
clarify

whether subpart O is superseded by the requirements of subparts MMMM
and LLLL, if both sets of site-specific limits and reporting
requirements apply, and whether a site-specific determination is
necessary to avoid having to demonstrate compliance with both sets of
requirements independently.
    Response: This comment is outside the scope of the SSI federal
plan. 40 CFR part 60, subparts O, MMMM, and LLLL remain in effect in
the CFR. Any affected facilities would need to comply with both
regulations. For the most part, subparts MMMM and LLLL are more
stringent than subpart O. Generally, if a facility is in compliance
with the more stringent of the regulations, it would be in compliance
with the other less stringent regulation. The EPA recognizes the
differences between subpart O and subparts MMMM and LLLL. However,
subparts MMMM and LLLL do not relieve SSI units of complying with
subpart O, and therefore an owner/operator of an SSI unit that is
affected by subpart MMMM or LLLL and subpart O would need to comply
with both. For the scrubber pressure drop example, subpart O does
require a much shorter averaging time (15-minute average versus 12-hour
average), but a facility would only need to identify when this 15-
minute average is 30-percent below the average pressure drop during the
performance test. Subparts MMMM and LLLL do not have the 30-percent
allowance. Additionally, subparts MMMM and LLLL require data recording
at 15-minute intervals, so facilities should already have the 15-minute
average. Therefore, we do not believe that it is unreasonable or overly
burdensome to comply with both limits.

B. Affirmative Defense to Malfunctions

    As proposed, this final action does not include an affirmative
defense to malfunction events. In the 2011 SSI rule, the EPA included
an affirmative defense that provided that civil penalties would not be