[Federal Register Volume 76, Number 33 (Thursday, February 17, 2011)]
[Rules and Regulations]
[Pages 9450-9489]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-2608]
[[Page 9449]]
Vol. 76
Thursday,
No. 33
February 17, 2011
Part III
Environmental Protection Agency
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40 CFR Parts 9 and 63
National Emission Standards for Hazardous Air Pollutants: Gold Mine Ore
Processing and Production Area Source Category; and Addition to Source
Category List for Standards; Final Rule
Federal Register / Vol. 76 , No. 33 / Thursday, February 17, 2011 /
Rules and Regulations
[[Page 9450]]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 9 and 63
[EPA-HQ-OAR-2010-0239; FRL-9242-3]
RIN 2060-AP48
National Emission Standards for Hazardous Air Pollutants: Gold
Mine Ore Processing and Production Area Source Category; and Addition
to Source Category List for Standards
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: EPA is adding the gold mine ore processing and production area
source category to the list of source categories to be regulated under
Section 112(c)(6) of the Clean Air Act due to its mercury emissions.
EPA is also promulgating national emission standards for hazardous air
pollutants to regulate mercury emissions from this source category.
DATES: This final rule is effective on February 17, 2011. The
incorporation by reference of certain publications listed in the final
rule is approved by the Director of the Federal Register as of February
17, 2011.
ADDRESSES: EPA has established a docket for this action under Docket ID
No. EPA-HQ-OAR-2010-0239. All documents in the docket are listed on the
http://www.regulations.gov 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 on the Internet and will be publicly available only in hard
copy form. Publicly available docket materials are available either
electronically through www.regulations.gov or in hard copy at the EPA
Headquarters Library, Room Number 3334, EPA West Building, 1301
Constitution Ave., NW., Washington, DC. The EPA/DC Public Reading Room
hours of operation are 8:30 a.m. to 4:30 p.m. Eastern Standard Time
(EST), Monday through Friday. The telephone number for the Public
Reading Room is (202) 566-1744, and the telephone number for the Air
and Radiation Docket and Information Center is (202) 566-1742.
FOR FURTHER INFORMATION CONTACT: Mr. Chuck French, Sector Policies and
Program Division, Office of Air Quality Planning and Standards (D243-
02), Environmental Protection Agency, Research Triangle Park, North
Carolina 27711, telephone number (919) 541-7912; fax number (919) 541-
3207, e-mail address: [email protected].
SUPPLEMENTARY INFORMATION: The information presented in this preamble
is organized as follows:
I. General Information
A. Does this action apply to me?
B. Where can I get a copy of this document?
C. Judicial Review
II. Addition to Section 112(c)(6) Source Category List
III. What is the statutory authority and regulatory approach for the
proposed standards?
IV. Summary of Significant Changes Since Proposal
A. Applicability
B. Final Emission Standards
C. Compliance Dates
D. Compliance Requirements
E. Monitoring Requirements
F. Definitions
V. Summary of Responses to Major Comments
A. Statutory Requirements
B. Applicability
C. MACT Floors
D. Compliance Determinations
E. Monitoring Requirements
F. Definitions
VI. Summary of Environmental, Economic and Health Benefits
VII. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review
B. Paperwork Reduction Act
C. Regulatory Flexibility Act
D. Unfunded Mandates Reform Act
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 and Safety Risks
H. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
I. National Technology Transfer and Advancement Act
J. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income
Populations
K. Congressional Review Act
I. General Information
A. Does this action apply to me?
The regulated categories and entities potentially affected by this
final rule include:
------------------------------------------------------------------------
Examples of
Category NAICS code \1\ regulated entities
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Industry:
Gold Ore Mining.............. 212221 Establishments
primarily engaged
in developing the
mine site, mining,
and/or
beneficiating
(i.e., preparing)
ores valued chiefly
for their gold
content.
Establishments
primarily engaged
in transformation
of the gold into
bullion or dore bar
in combination with
mining activities
are included in
this industry.
------------------------------------------------------------------------
\1\ North American Industry Classification System.
This table is not intended to be exhaustive, but rather provides a
guide for readers regarding entities likely to be affected by this
action. To determine whether your facility would be regulated by this
action, you should examine the applicability criteria in 40 CFR
63.11640 of subpart EEEEEEE (National Emission Standards for Hazardous
Air Pollutants (NESHAP): Gold Mine Ore Processing and Production Area
Source Category). If you have any questions regarding the applicability
of this action to a particular entity, consult either the air permit
authority for the entity or your EPA Regional representative, as listed
in 40 CFR 63.13 of subpart A (General Provisions).
B. Where can I get a copy of this document?
In addition to being available in the docket, an electronic copy of
this final action will also be available on the Worldwide Web (WWW)
through the EPA Technology Transfer Network (TTN). Following signature,
a copy of this final action will be posted on the TTN's policy and
guidance page for newly proposed or promulgated rules at the following
address: http://www.epa.gov/ttn/oarpg/. The TTN provides information
and technology exchange in various areas of air pollution control.
C. Judicial Review
Under Section 307(b)(1) of the Clean Air Act (CAA), judicial review
of this final rule is available only by filing a petition for review in
the U.S. Court of
[[Page 9451]]
Appeals for the District of Columbia Circuit by April 18, 2011. Under
section 307(d)(7)(B) of the CAA, only an objection to this final rule
that was raised with reasonable specificity during the period for
public comment can be raised during judicial review. Moreover, under
section 307(b)(2) of the CAA, the requirements established by this
final rule may not be challenged separately in any civil or criminal
proceedings brought by EPA to enforce these requirements.
Section 307(d)(7)(B) also provides a mechanism for us to convene a
proceeding for reconsideration, ``[i]f the person raising an objection
can demonstrate to EPA that it was impracticable to raise such
objection within [the period for public comment] or if the grounds for
such objection arose after the period for public comment (but within
the time specified for judicial review) and if such objection is of
central relevance to the outcome of the rule.'' Any person seeking to
make such a demonstration to us should submit a Petition for
Reconsideration to the Office of the Administrator, U.S. EPA, Room
3000, Ariel Rios Building, 1200 Pennsylvania Ave., NW., Washington, DC
20460, with a copy to the person listed in the preceding FOR FURTHER
INFORMATION CONTACT section.
II. Addition to Section 112(c)(6) Source Category List
For reasons stated in the preamble to the proposed rule (75 FR
22470, April 28, 2010), we are adding the gold mine ore processing and
production area source category to the list of source categories under
section 112(c)(6) on the basis of its mercury emissions. The preamble
for the proposed rule provides a description of this industry including
the processes used and the typical control technologies applied.
III. What is the statutory authority and regulatory approach for the
proposed standards?
As explained in the preamble to the proposed rule, CAA section
112(c)(6) requires that EPA set standards under section 112(d)(2) or
(d)(4). The mercury standards for the gold mine ore processing and
production area source category are being established under CAA section
112(d)(2), which requires maximum available control technology (MACT)
level of control. Under CAA section 112(d), the MACT standards for
existing sources must be at least as stringent as the average emissions
limitation achieved by the best performing 12 percent of existing
sources (for which the administrator has emissions information) for
source categories and subcategories with 30 or more sources, or the
best performing 5 sources for categories and subcategories with fewer
than 30 sources (CAA section 112(d)(3)(A) and (B)). This level of
minimum stringency is called the MACT floor. For new sources, MACT
standards must be at least as stringent as the emission control that is
achieved in practice by the best controlled similar source (CAA section
112(d)(3)). EPA also must consider more stringent ``beyond-the-floor''
control options. When considering beyond-the-floor options, EPA must
consider not only the maximum degree of reduction in emissions of HAP,
but must take into account costs, energy, and nonair quality health and
environmental impacts when doing so.
IV. Summary of Significant Changes Since Proposal
This section summarizes the significant changes to the rule since
proposal. Additional information on the basis for these changes and
other changes can be found in the Summary of Responses to Major
Comments in section V of this preamble and in the Summary of Comments
and Responses document which is available in the docket for this
action.
A. Applicability
We have clarified in Sec. 63.11651 of the final rule that the term
``gold mine ore processing and production facility'' does not include
individual prospectors and very small pilot scale mining operations.
These types of operations are very small and were not included in the
section 112(c)(6) inventory that was the basis for the listing of the
gold mine ore processing and production source category.
B. Final Emission Standards
We have made changes to all of the proposed emission standards as
the result of the following developments: (1) Inclusion of additional
emissions test data received since proposal; \1\ (2) additional
analyses in response to public comments on the proposed rule; \2\ and
(3) further review of the data used to develop the standards for the
proposed rule. The changes are summarized below and described in more
detail in section V of this preamble. We estimate the final MACT
standards will reduce mercury emissions from gold mine ore processing
and production down to a level of about 1,180 pounds per year, which
will be an estimated 77 percent reduction from the 2007 emissions level
(5,000 lb/yr), a 95 percent reduction from year 2001 emissions level
(about 23,000 lb/yr), and more than 97 percent reduction from
uncontrolled emissions levels (more than 37,000 lb/yr).
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\1\ The new test data used in final MACT standard calculations
can be found in the docket as docket items: EPA-HQ-OAR-2010-0239-
0359 and EPA-HQ-OAR-2010-0239-0360.
\2\ Analyses for the final MACT standards can be found in the
docket in the document titled: ``Development of the MACT Floors and
MACT for the Final NESHAP for Gold Mine Ore Processing and
Production'' (also known as the ``MACT Development Document'').
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Ore Pretreatment Processes
In the proposed rule, the proposed mercury emission standards for
both existing and new ore pretreatment processes were 149 pounds per
million tons of ore processed (lb/million tons of ore). In the final
rule, the emission standard for existing sources is 127 lb/million tons
of ore; and for new sources the emission standard is 84 lb/million tons
of ore. The final emission standards are based on several changes to
the data set used in the MACT analysis. Since we issued the proposed
rule, we collected emissions data from more recent tests that were not
available at proposal. Further, we learned that two emissions tests
that we used to develop the MACT floor in our proposed rule had been
invalidated by the Nevada Division of Environmental Protection (NDEP),
and we removed those test results from the database. Information on the
specific tests invalidated and the rationale are available in the
docket (docket item number EPA-HQ-OAR-2010-0239-0061). We also
discovered that the test data for a unit within the ore pretreatment
affected source at a facility should have been included as part of a
different unit at the same facility. We have also dropped the data for
one facility from the analysis because their autoclave was shut down in
2007 and dismantled, and the only test data we had for them was one
test of the autoclave when it was operating in 2006. Moreover, we
conducted additional beyond-the-floor analyses for the ore pretreatment
affected source. The new information and analyses described above are
discussed in more detail in section V.C of this preamble and in the
MACT Development Document which is available in the docket for this
rulemaking.
The resulting data set included emissions data for four facilities
that ranged from 45 to 165 lb/million tons of ore. Based on these data,
and using the same upper prediction limit (UPL) approach used for
proposal to account for variability, we determined the MACT floor to be
158 lb/million tons of ore for existing sources of ore pretreatment
processes and 84 lb/
[[Page 9452]]
million tons of ore for new sources. As explained in the proposed rule
(75 FR at 22482), the technologies that we estimate are needed to
achieve the MACT floor level of performance for existing ore
pretreatment processes include calomel-based mercury scrubbers on
roasters and venturi scrubbers on autoclaves and ancillary roaster
operations. The preamble to the proposed rule provides a description of
the UPL and the approach and calculations used to derive the UPL. The
UPL is also discussed further in section V.
In our beyond-the-floor analysis, we evaluated the potential to add
condensers and carbon adsorbers to control autoclaves, and the
potential to add carbon adsorbers to control the ore pre-heaters. Based
on this beyond-the-floor analysis, we concluded that it is feasible and
cost-effective to establish the MACT standard for existing sources at a
level lower than the MACT floor. Based on the analysis, we determined
the MACT standard for existing sources to be 127 lb/million tons of
ore. For new sources, we determined that it was not feasible and cost-
effective to establish a standard lower than the new source MACT Floor
(of 84 lb/million tons); therefore the MACT standard for new sources
was determined to be 84 lb/million tons.
The technologies needed to achieve the new source MACT floor will
depend on the types of ore processed, amount of mercury in the ore, and
specific process units used. Nevertheless, we conclude that, at a
minimum, the controls that would be needed would include calomel-based
mercury scrubbers on roasters and venturi scrubbers on autoclaves and
ancillary roaster operations. Additional controls that will likely be
needed to achieve emissions at or below the new source MACT floor level
include condensers and carbon adsorbers on autoclaves, and carbon
adsorbers on ore preheaters.
Table 1 summarizes the MACT floor analysis for existing and new ore
pretreatment processes. The beyond-the-floor analyses are explained
further in section V of this preamble and in more detail in the MACT
Development document.
Table 1--MACT Floor Results for Ore Pretreatment Processes
------------------------------------------------------------------------
Average
performance
Facility (lb/million
tons of ore)
------------------------------------------------------------------------
A......................................................... 45
C......................................................... 56
E......................................................... 71
D......................................................... 165
Average of the 4 facilities............................... 84
99% UPL for existing sources (i.e., the MACT Floor for 158
existing sources)........................................
99% UPL for new sources \1\ (i.e., the MACT Floor for new 84
sources).................................................
------------------------------------------------------------------------
\1\ The MACT Floor for new sources is based on the average performance
of Facility A (i.e., 45) plus an amount to account for variability
(i.e., 45 + 39 = 84).
Carbon Processes
Under the proposed rule, all carbon processes were subject to the
same proposed mercury emissions limits of 2.6 pounds per ton of
concentrate (lb/ton of concentrate) for existing sources and, for new
sources, either 0.14 lb/ton of concentrate or 97 percent reduction in
uncontrolled mercury emissions. These limits would have applied to
facilities that operate mercury retorts and facilities that do not
operate mercury retorts. In the final rule, we distinguish between
carbon processes with mercury retorts and carbon processes without
mercury retorts because we believe there are unique differences in
these two types of processes. Therefore, the final rule specifies
separate emission standards for these two types of processes. Moreover,
the final emission standards for carbon processes reflect inclusion of
new test data that were not available at proposal. We also revised our
data set based on new information that we received since proposal which
impacted which sources were among the best performing sources. Based on
the data that we have, there are 10 facilities that have carbon
processes with mercury retorts, and we have mercury emissions data for
all 10 of these facilities. There are approximately 7 facilities that
have carbon processes without mercury retorts, and we have
comprehensive and reliable mercury emissions data for 2 of these
facilities. These 2 facilities are the best controlled facilities
within that group based on the information we have. (See section V for
further details.) For carbon processes with mercury retorts, the
emission standard in the final rule is 2.2 lb/ton of concentrate for
existing sources and 0.8 lb/ton of concentrate for new sources. For
carbon processes without mercury retorts, the emission standard in the
final rule is 0.17 lb/ton of concentrate for existing sources and 0.14
lb/ton of concentrate for new sources.
For carbon processes, regardless of whether the facility operates a
mercury retort, we estimate that to meet the MACT floor facilities
would generally need to have mercury condensers and carbon adsorbers to
control mercury emissions. We also considered beyond-the-floor options
for both existing and new sources for these process groups, which were
based on the addition of a second carbon adsorber; however, we rejected
those options because they are not cost effective. Additional
information on the analyses performed can be found in the MACT
Development document in the docket for this rulemaking.
We also eliminated in the final rule the compliance alternative of
97 percent reduction for new carbon processes. After reviewing the
comments received on this proposed alternative standard and giving
further consideration to the practicality of how it would be measured,
we concluded that this option would be difficult to implement,
particularly when multiple processes that are operated at different
times vent to a single control device and stack. In addition, we have
limited data supporting this compliance alternative. In proposing this
alternative for comment, we had hoped to, but did not, receive
additional data indicating that the 97 percent reduction option would
be equivalent to the proposed new source limit of 0.14 pounds of
mercury per ton of concentrate. For the reasons stated above, we
eliminated the 97 percent control efficiency option for new carbon
processes in the final rule.
Table 2 summarizes the results of the MACT floor analysis for
carbon processes with mercury retorts, and Table 3 summarizes the
analysis for carbon processes without mercury retorts.
Table 2--MACT Floor Results for Carbon Processes With Mercury Retorts
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Average
performance
Facility (lb/ton of
concentrate)
------------------------------------------------------------------------
N........................................................ 0.53
J........................................................ 0.74
I........................................................ 1.06
A........................................................ 1.47
H........................................................ 1.67
D........................................................ 2.20
C........................................................ 3.71
G........................................................ 8.17
E........................................................ 14.49
B........................................................ 20.60
[[Page 9453]]
Average of top 5......................................... 1.1
99% UPL for existing sources (i.e., MACT Floor for 2.2
existing sources).......................................
99% UPL for new sources (i.e., MACT Floor for new 0.8
sources)................................................
------------------------------------------------------------------------
Table 3--MACT Floor Results for Carbon Processes Without Mercury Retorts
------------------------------------------------------------------------
Average
performance
Facility (lb/ton of
concentrate)
------------------------------------------------------------------------
M........................................................ 0.058
F........................................................ 0.098
Average of top 2 facilities.............................. 0.078
99% UPL for existing sources (i.e., MACT Floor for 0.17
existing sources).......................................
99% UPL for new sources (i.e., MACT Floor for new 0.14
sources)................................................
------------------------------------------------------------------------
Non-Carbon Concentrate Processes
Under the proposed rule, the mercury emission standards for non-
carbon concentrate processes were 0.25 lb/ton of concentrate for
existing sources and 0.2 lb/ton of concentrate for new sources. In the
final rule, the emission standards for these sources are 0.2 lb/ton of
concentrate for existing sources and 0.1 lb/ton of concentrate for new
sources. These standards are based on using new emissions data that
were not available when we developed the proposal, along with the data
that were used for the proposal. For non-carbon concentrate processes,
we estimate that to meet the MACT floors, for both existing and new
sources, facilities would generally need to control mercury emissions
using mercury condensers and carbon adsorbers. As explained in the
proposed rule, we considered beyond-the-floor controls for these
processes (which were based on adding a second carbon adsorber to the
MACT floor level controls) but concluded those controls would not be a
cost-effective option. There are approximately 3 facilities in the U.S.
that use these types of processes. We have emissions tests data for 2
of these facilities.
Table 4 summarizes the results of the MACT floor analysis for non-
carbon concentrate processes.
Table 4--MACT Floor Results for Non-Carbon Concentrate Processes
------------------------------------------------------------------------
Average
performance
Facility (lb/ton of
concentrate)
------------------------------------------------------------------------
K........................................................ 0.047
L........................................................ 0.078
Average of 2 facilities.................................. 0.062
99% UPL for existing sources (i.e., MACT Floor for 0.2
existing sources).......................................
99% UPL for new sources (i.e., MACT Floor for new 0.1
sources)................................................
------------------------------------------------------------------------
C. Compliance Dates
In the final rule, we provide in Sec. 63.11641 that the compliance
date for existing sources is 3 years after promulgation of the final
rule as opposed to 2 years as proposed. We reviewed the information
provided in public comments on the challenges of installing new
controls, especially for autoclaves, which, although the controls have
not yet been demonstrated, have been proposed by facilities with
autoclaves in their Nevada Mercury Control Program (NMCP) permit
applications. We also considered the installation of new controls on
the roaster preheaters, which also have not yet been demonstrated, but
have been proposed by these facilities in their NMCP permit
applications. We concluded that allowing 3 years for existing sources
to comply is appropriate, given the complexity of the sources, the
combinations of control devices that are needed in many cases, and the
amount of time necessary for designing, installing, testing, and
commissioning additional emission controls for mercury.
D. Compliance Requirements
Section 63.11646(a)(1) of the final rule does not include Method
30A, as was proposed, as an appropriate method for determining mercury
concentration because it is not yet in general use. This paragraph
further clarifies that the use of ASTM D6784-02 and Method 30B are
allowed for compliance tests only if approved by the permit authority
as opposed to automatically being allowed as in the proposal. The final
rule also does not include the requirement to follow the acetone rinse
procedures and the absence of cyclonic flow determination requirement,
which were in subparagraphs (v) and (vi) respectively of our proposed
Sec. 63.11646(a)(1). Method 29 already includes requirements for the
acetone rinse, so there is no need to specify those procedures in the
rule; and Method 1, which is required by the rule, addresses the issue
of cyclonic flow.
In Sec. 63.11646(a)(2), we changed the minimum sample volume when
Method 29 is used to determine compliance from the proposed 60 dry
standard cubic feet (dscf) to 30 dscf. We believe this volume is
adequate for detecting mercury in the samples and determining mercury
emissions for this industry. We have also expanded this section to
address non-detect values. If the emission testing results for any of
the emission points yield a non-detect value, the final rule requires
that the minimum detection limit (MDL) be used to calculate the mass of
emissions (in pounds of mercury) for that emission point that would
subsequently be used in the calculations to determine if the source is
in compliance with the MACT standard. If the resulting calculations
indicate that mercury emissions are greater than the MACT emission
standard, the owner or operator may repeat the mercury emissions
testing one additional time for any emission point for which the
measured result was below the MDL using procedures that produce lower
MDL results. If this additional testing is performed, the results from
that testing must be used to determine compliance.
For sources with multiple emission units (e.g., two roasters)
ducted to a common control device and stack, we have clarified in Sec.
63.11646(a)(3) that compliance testing must either be performed with
all affected emissions units in operation, if this is possible, or
units must be tested separately. We also clarified that the
establishment of operating limits for units that share a common stack
can be based on emissions when all process units are operating
together, or based on testing units separately. However, this
requirement does not affect the frequency and schedule for monitoring,
which are specified in the rule. If facilities have batch type
processes that cannot be operated simultaneously, then the facility can
test some or all of the units individually.
In Sec. 63.11646(a)(6) and (7), we clarify that the production
data used in compliance determinations are based on full calendar
months. For the initial compliance test, data for all the full calendar
months between publication of the final rule and the initial compliance
test must be used. This initial compliance determination must include
at least one full month of production
[[Page 9454]]
data (e.g., hours of operation, and million tons of ore processed or
tons of concentrate processed) including the month the test was
conducted. For subsequent annual compliance tests, data for the 12 full
calendar months prior to the annual compliance test must be used to
demonstrate compliance. In addition, we clarify in paragraphs Sec.
63.11646(a)(5), (6) and (7) that compliance determinations are based on
the number of 1-hour periods each process unit operates. By using the
1-hour period terminology, the final rule language is consistent with
the terminology used in the General Provisions to part 63.
Because the final rule does not include the 97 percent reduction
option that was in Sec. 63.11645(e)(2) of the proposed rule, we have
removed from the final rule the compliance requirement for that option
that was in Sec. 63.11646(b) of the proposed rule, which addressed
testing the inlets and outlets for sources choosing that proposed
option.
E. Monitoring Requirements
Section 63.11647(a) of the final rule includes an additional option
for monitoring mercury emissions from roasters. The proposed rule
specified two options for monitoring mercury emissions: Paragraph
(a)(1) specified weekly sampling using PS 12B; and paragraph (a)(2)
specified continuous monitoring using a mercury continuous emissions
monitoring system (CEMS). In the final rule, we added paragraph (a)(3)
to provide a third option of continuous sampling using PS 12B. In
addition, paragraph (a)(1) in the final rule was changed to require
sampling at least twice per month using either PS 12B or Method 30B
rather than weekly. We believe that Method 30B is an acceptable
alternative method for monitoring purposes and allows owners and
operators more flexibility in how they monitor roaster emissions. We
also believe that sampling twice per month coupled with extensive
parametric monitoring of control devices (as explained below) is
sufficient for the monitoring option in paragraph (a)(1).
Section 63.11647(a)(4)(iii) of the proposed rule would have
required additional compliance testing if the mercury concentration in
the ore fed to the roaster was higher than any concentration measured
in the previous 12 months. We have removed this requirement from the
final rule because it is not clear that the mercury content of the ore
has a significant effect on the performance of mercury scrubbers
applied to roasters, which are designed to handle and operate
efficiently for a range of mercury inlet concentrations. In addition,
condensers are used to recover liquid elemental mercury prior to the
mercury scrubber, and any increase in mercury loading would likely
result in an increase in the recovery of elemental mercury.
The final rule incorporates several changes to Sec. 63.11647(b),
which addresses monitoring of calomel-based mercury scrubbers (i.e.,
mercury scrubbers) that are used to control emissions from roasters.
The proposed rule required monitoring of the scrubber liquid flow,
liquid chemistry, scrubber pressure drop, and scrubber inlet gas
temperature hourly. The final rule does not include the requirement to
monitor pressure drop across calomel-based scrubbers because we
conclude that pressure drop is not related to mercury emission control
performance by this type of control device. In addition, the final rule
allows hourly monitoring of the line pressure in the scrubber liquid
supply line as an alternative to hourly monitoring of scrubber liquid
flow rate. Line pressure monitoring is already in practice at some
facilities and provides the same type of information as does liquid
flow rate. As was proposed, the final rule allows the operating limit
for scrubber liquid flow rate (or line pressure) and inlet gas
temperature to be based on the minimum flow rate (or line pressure) or
maximum inlet gas temperature established during the initial
performance test. It also includes two additional options for setting
these operating limits: (1) Based on the manufacturer's specifications
if certain types of systems are designed to operate within a specified
range of flow rates or temperatures; and (2) based on limits
established by the permitting authority. If the facility chooses the
option to establish the limits during initial compliance, the final
rule requires the scrubber flow rate operating limit to be based on
either the lowest value for any run of the initial compliance test or
10 percent less than the average value measured during the compliance
test and the inlet gas temperature operating limit to be based on
either the highest value for any run of the initial compliance test or
10 percent higher than the average value measured during the compliance
test. This requirement takes into account the fact that, although
initially the system may exhibit little variability from test run to
test run, the short-term variability in performance may increase with
time. Additional discussion of these changes can be found in section
V.E of this preamble and in the Summary of Public Comments and
Responses document in the docket for this rulemaking.
In response to comments, we have revised the requirements for
corrective action following control device monitoring parameter
exceedances specified in Sec. 63.11647(d). Under the final rule, if
the corrective actions taken following an exceedance do not result in
the parameter value (e.g., liquid flow rate, line pressure, or inlet
gas temperature) being returned to within the parameter range or limit
within 48 hours, a mercury concentration measurement must be made to
determine if the operating limit for mercury concentration is being
exceeded. The measurement must be performed and the concentration
determined within 48 hours after the initial 48 hours, or a total of 96
hours from the time the parameter was exceeded. If the measured mercury
concentration meets the operating limit for mercury concentration, the
corrective actions are deemed successful. In addition, the owner or
operator may request approval from the permitting authority to change
the parameter range or limit based on measurements of the parameter at
the time the mercury concentration measurement was made. If, on the
other hand, the measured mercury concentration indicates the operating
limit for mercury concentration is exceeded, the exceedance must be
reported as a deviation within 24 hours to the permitting authority,
and the facility must perform a compliance test (pursuant to Sec.
63.11647(d)) within 40 days to determine whether the source is in
compliance with the MACT standard. We believe 40 days is appropriate
because it may take 3 to 4 weeks to schedule and have the testing
contractor on site, and, following completion of the test, another week
or so to receive the final test results, and allows sufficient time to
notify the permitting authority. We also removed the requirement that
roasters must be shut down if a parameter is out of range.
In Sec. 63.11647(a)(1)(ii) of the final rule, we require these
same corrective actions described above (i.e., measuring mercury
concentration within 48 hours, reporting a deviation if the data show
the operating limit was exceeded within 24 hours, and conducting a
compliance test within 40 days) for exceedances of mercury
concentration operating limits indicated by the results of the twice
monthly monitoring using PS 12B or Method 30B, CEMS, or continuous
monitoring using PS 12B. In such cases, the owner or operator must use
the results of the compliance test to determine if the ore pretreatment
[[Page 9455]]
process affected source is in compliance with the emission standard. If
the source is determined to be in compliance, the owner or operator may
use this compliance test to establish a new operating limit for mercury
concentration for the roaster. We also removed the requirement that
roasters must be shut down if the mercury concentration is out of
range.
In the final rule, Sec. 63.11647(f)(1) requires monthly sampling
of the exhaust stream of carbon adsorbers using Method 30B. The
duration of sampling must be at least the minimum sampling time
specified in Method 30B and up to one week. The proposed rule required
a full week of such sampling, but, as pointed out by one of the
commenters, breakthrough of the sampling trap from exhaust streams with
high mercury concentrations could occur before a week had elapsed.
Section 63.11647(f)(2) of the final rule clarifies that sampling of
the carbon bed must be collected from the inlet and outlet of the bed.
This paragraph also specifies that, for carbon adsorbers with multiple
carbon columns or beds, the sampling should be performed in the first
and last column or bed rather than at the inlet or outlet.
We have deleted Sec. 63.11647(f)(3) in the proposed rule, which
allowed the carbon bed change-out rate to be determined based on
historical data and the estimated life of the carbon. We have concluded
that this method would not be adequate to ensure that breakthrough does
not occur earlier than expected.
We have clarified Sec. 63.11647(h) with respect to the monitoring
of scrubbers (other than the calomel-based mercury scrubbers described
above). Under the final rule, owners or operators are required to
monitor and record water flow rate (or line pressure) and scrubber
pressure drop once per shift; they also must record any occurrences
when the water flow rate (line pressure) or pressure drop are outside
the operating range, take corrective actions to return the water flow
rate (line pressure) or pressure drop back in range, and record the
corrective actions taken. At proposal, the water flow rate and pressure
drop were to be monitored continuously. However, measuring the water
flow rate (line pressure) and pressure drop once per shift will provide
two to three measurements per day, and we believe that is sufficient to
assure proper operations of the wet scrubber, and thus assure
compliance with the emission standards. We have also added the option
of monitoring the line pressure in the scrubber liquid supply line as
an alternative to monitoring scrubber liquid flow rate because line
pressure monitoring is already in practice at some facilities and
provides the same type of information as does liquid flow rate. As was
proposed, the final rule allows the operating limit for water flow rate
and pressure drop to be based on the minimum value during the initial
performance test. It also includes two additional options for setting
the operating limit: (1) Based on the manufacturer's specifications;
and (2) based on limits established by the permitting authority. We
have also clarified that, for scrubbers on autoclaves, the pressure
drop parameter range should be established from manufacturer's
specifications only.
F. Definitions
We have added a definition of carbon adsorber to Sec. 63.11651 to
clarify that this term, as used in the final rule, includes control
devices consisting of a single fixed carbon bed, multiple carbon beds
or columns, carbon filter packs or modules, and other variations of
carbon adsorber design.
The definition of ``gold mine ore processing and production
facility'' in Sec. 63.11651 of the rule has been clarified to state
that small operations, such as prospectors and very small pilot scale
mining operations, that process or produce less than 100 pounds of
concentrate per year are excluded from the source category. These
prospectors and very small pilot-scale operations (that process at or
below this level) were not included in the section 112(c)(6) inventory
that was the basis for the listing of gold mine ore processing and
production source category. These types of very small operations were
not intended to be subject to the final rule, and we do not expect any
significant emissions from them. We also clarified that the source
category does not include facilities at which 95 percent or more of the
metals produced are metals other than gold. For example, if other non-
ferrous metals (such as copper, lead, nickel, or zinc) comprise 95
percent or more of the product, the facility is not part of the gold
ore processing and production source category.
V. Summary of Responses to Major Comments
A. Statutory Requirements
1. Listing of the Gold Mine Ore Processing and Production Source
Category Under Section 112(c)(6)
Comment: One commenter stated that adding the gold mine ore
processing and production category to the list of categories required
by Clean Air Act (CAA) section 112(c)(6) was correct and required
because gold mines accounted for a significant portion of the aggregate
emissions of mercury in the baseline year (1990) and because they still
do so today. Other commenters stated that EPA does not have the
authority to list gold mining processing and production as a source
category under section 112(c)(6) and noted that section 112(c)(6)
requires EPA to list, by 1995, categories of sources that make up 90
percent of the 1990 emissions for a subset of hazardous air pollutants
(HAP), including mercury. The commenters said that EPA concluded its
statutory listing obligation for mercury in 1998 with the publication
of a list of source categories constituting 90 percent of aggregate
mercury emissions, and that gold mining was not included on that list
in 1998. In addition, the commenters said that the CAA requires EPA to
list all categories under section 112(c)(6) by 1995 and complete
issuance of standards for all listed sources by 2000, a task that would
be impossible if EPA had the authority to add source categories ad
infinitum.
Response: We appreciate the commenter's support in listing the gold
mine processing and production area source category pursuant to section
112(c)(6). We disagree, however, with the commenters that assert that
EPA is precluded from listing additional categories pursuant to section
112(c)(6). The commenters appear to be arguing that EPA is limited to a
single listing opportunity under section 112(c)(6) and, having not
listed gold mine ore processing and production in the initial 1998
listing effort, EPA is now foreclosed from doing so. There is nothing
in the language of section 112(c)(6), however, that precludes EPA from
listing additional source categories to the extent EPA determines that
those categories are needed to meet the 90 percent requirement in
section 112(c)(6). Indeed, the commenter's reading is contrary to the
fundamental purpose of section 112(c)(6).
The core requirement of section 112(c)(6) is that EPA ``shall * * *
list categories and subcategories of sources assuring that sources
accounting for not less than 90 per centum of the aggregate emissions
of each such pollutant'' are subject to standards under either
11217FE0(d)(2) or (d)(4). EPA reasonably interprets section 112(c)(6)
as allowing it to revise the list to add categories, where, as here, it
determines that it needs the additional categories to meet the 90
percent requirement in section 112(c)(6). Indeed, EPA has previously
revised the section 112(c)(6)
[[Page 9456]]
list to add a source category, where EPA determined that category was
needed to meet its 90 percent requirement for mercury. See 72 FR 74087
(Dec. 28, 2007) (adding area source electric arc furnaces to the
section 112(c)(6) list).
As explained in the proposed rule, we have a 1990 baseline
emissions inventory, and it is against this baseline that we assess
compliance with the 90 percent requirement for each of the pollutants
specified in section 112(c)(6). EPA explained in the initial 1998
listing notice that it was using 1990 as the baseline year for
assessing compliance with the 90 percent requirement. As EPA has
developed emission standards for the sources included on the initial
section 112(c)(6) list, it has acquired additional information on those
sources and their emissions in 1990, which has resulted in some
revisions to the 1990 baseline emissions inventory estimates. These
revisions resulted in the need to regulate an additional source
category. See 72 FR 74087 (setting standards for area source electric
arc furnaces).
In addition to obtaining additional information concerning the
source categories on the initial list, EPA has obtained additional
information concerning the 1990 emissions of other sources. As
explained in the preamble to the proposed rule, at the time of the
initial section 112(c)(6) listing, there was very little available
information on mercury emissions from gold mine ore processing and
production. See 75 FR 22471. Because EPA lacked emissions information
on mercury emissions from this source category at the time of the
listing decision, EPA was unable to estimate the 1990 baseline mercury
emissions from the gold mine ore processing and production source
category and include this category in the first listing effort. Based
on information that became available after the initial listing, EPA now
finds that regulation of the area source gold mine ore processing and
production category is needed to meet the 90 percent requirement for
mercury. 75 FR 22471. Under the commenters' view, EPA cannot add any
additional categories to the section 112(c)(6) list following the
initial listing. If true, EPA could not meet its section 112(c)(6)
obligation--a result Congress could not have intended. EPA reasonably
interprets section 112(c)(6) in a manner that allows the Agency to
achieve that provision's core requirement. EPA repeats that it sees
nothing in the language or purpose of section 112(c)(6) that precludes
it from listing additional source categories as needed.
Finally, Congress left to EPA's discretion which categories and
subcategories of sources to include on the section 112(c)(6) list. We
have determined that we need the gold mine ore processing and
production source category to meet the 90 percent requirement in
section 112(c)(6) for mercury and are therefore now setting standards
for that category.
We also reject the comment that the task of completing standards by
2000 would be impossible if EPA had the authority to add source
categories. Nevertheless, EPA is under a court ordered deadline to
complete section 112(c)(6) standards by January 16, 2011. (Sierra Club
v. EPA, Consolidated Case No. 01-1537, D.D.C).
Comment: Some commenters claimed that EPA did not provide an
adequate basis for its 1990 emissions estimate for gold mining
processing and production. Specifically, they questioned EPA's
estimated emissions of 4.4 tons from this source category in the 1990
baseline year.
Response: Although the commenters question EPA's estimated
emissions of 4.4 tons from this source category in the 1990 baseline
year, they did not provide an alternative method for calculating such
emissions or alternative data or assumptions that should be used. They
also did not explain what they think the 1990 baseline emissions should
have been. EPA continues to maintain that its baseline emissions
estimate is reasonable. The methodology EPA used to derive that
estimate is described in docket item EPA-HQ-OAR-2010-0239-0175.
Comment: Several commenters stated that Phase 2 permits under the
Nevada Mercury Control Program (NMCP), which are scheduled for issuance
by the end of 2010, will result in MACT-level controls on all thermal
units at Nevada gold mines. According to the commenters, these permits
are the culmination of a 7-year collaborative effort between NDEP and
the gold mining industry to substantially reduce mercury emissions from
gold mine processes. The commenters said that the proposal does not
address how the NESHAP will result in reductions in mercury at gold
mines in areas of the country other than Nevada, where the mercury
content of the ore in gold mines is non-existent or only a fraction of
the amount found in Nevada, and Nevada accounted for 99 percent of
mercury emissions associated with gold mining operations in the United
States. According to the commenters, this shows that if Nevada has an
equivalent mercury control program for the gold mining industry, then
there is nothing to be gained from imposing a Federal program, and if
EPA acknowledges that the mines in Nevada are already well controlled,
then the listing of gold mining and the promulgation of an additional
layer of regulation at substantial cost to industry, but with little
environmental benefit, is both legally indefensible and practically
unsupportable.
Response: As explained above, we are regulating the gold mine ore
processing and production source category to meet the 90 percent
requirement in section 112(c)(6) for mercury and are therefore setting
standards for that category. Based on our 1990 baseline inventory for
section 112(c)(6) and other emissions information for subsequent years,
we estimate that this industry was among the top ten highest emitting
categories of mercury emissions in the U.S. in 1990 and has remained in
the top 10 since that time. Moreover, even though most emissions are
from facilities located in Nevada, several commenters expressed serious
concerns about the potential for mercury emissions from new gold mines
in other States (e.g., Alaska). We share these concerns about potential
emissions from new gold mine facilities. Finally, Congress left to
EPA's discretion which categories and subcategories of sources to
include on the section 112(c)(6) list. We are regulating the gold mine
ore processing and production source category to meet the 90 percent
requirement in section 112(c)(6) for mercury and are therefore now
promulgating a Federal NESHAP for existing and new gold mine ore
processing and production facilities.
2. Emission Standards for HAP Other Than Mercury
Comment: One commenter stated that CAA section 112(c)(6) provides
that EPA must ``list categories and subcategories of sources assuring
that sources accounting for not less than 90 percent of each
[enumerated] pollutant are subject to standards under subsection (d)(2)
or (d)(4) of this section.'' The commenter also stated that the D.C.
Circuit has held repeatedly that when EPA sets standards for a category
or subcategory of sources under section 112(d)(2), EPA has a statutory
duty to set emission standards for each HAP that the sources in that
category or subcategory emit (e.g., National Lime Ass'n v. EPA, 233
F.3d 625, 633-634 (D.C. Cir. 2000)). The commenter concluded that when
EPA sets standards for gold mines under section 112(d)(2), as section
112(c)(6) requires it to do, EPA must set section 112(d)(2) emission
standards for all the HAP that gold mines emit.
The commenter said that EPA appears to believe that because gold
mines are
[[Page 9457]]
needed only to reach the section 112(c)(6) requirement of 90 percent
for mercury and not for the other pollutants enumerated in section
112(c)(6), EPA's only obligation under section 112(c)(6) is to set
section 112(d)(2) standards for mercury. The commenter said that
section 112(c)(6) expressly requires EPA to issue section 112(d)(2)
standards for the ``sources'' in the categories listed under section
112(c)(6), not some subset of the pollutants that those sources emit,
and that section 112(d)(2) standards must include emission standards
for each HAP that a source category emits. The commenter continued by
stating that nothing in the CAA exempts EPA from this requirement. The
commenter concluded that, had Congress wished to give EPA discretion to
set standards for only some of the pollutants emitted by a category
listed under section 112(c)(6), it would have done so expressly.
Response: EPA disagrees with the comment that, even though EPA
lists a category under section 112(c)(6) due to the emissions of one or
more HAP specified in that section, EPA must issue emission standards
for all HAP (including HAP not listed in section 112(c)(6)) that
sources in that category emit. The commenter cited in support the
opinion by the United States Court of Appeals for the DC Circuit in
National Lime Ass'n v. EPA, 233 F.3d 625, 633-634 (D.C. Cir. 2000)).
The part of the National Lime opinion referenced in the comment dealt
with EPA's failure to set emission standards for certain HAPs emitted
by major sources of cement manufacturing because the Agency found no
sources using control technologies for those HAP. In rejecting EPA's
argument, the court stated that EPA has ``a statutory obligation to set
emission standards for each listed HAP.'' Id. at 634. The Court noted
the list of HAP in section 112(b) and stated that section 112(d)(1)
requires that EPA ``promulgate regulations establishing emission
standards for each category or subcategory of major sources * * * of
hazardous air pollutants listed for regulation. * * *'' Id. (Emphasis
added). For the reasons stated below, we do not believe that today's
final rule is controlled by or otherwise conflicts with the National
Lime decision.
National Lime did not involve section 112(c)(6). That provision is
ambiguous as to whether standards for listed source categories must
address all HAP or only the section 112(c)(6) HAP for which the source
category was listed. Section 112(c)(6) requires that ``sources
accounting for not less than 90 per centum of the aggregate emissions
of each such [specific] pollutant are subject to standards under
subsection (d)(2) or (d)(4).'' This language can reasonably be read to
mean standards for the section 112(c)(6) HAP or standards for all HAP
emitted by the source. Under either reading, the source would be
subject to a section 112(d)(2) or (d)(4) standard.
The commenter insists that once a section 112(d)(2) standard comes
into play, all HAP must be controlled (per National Lime). But this
result is not compelled by the pertinent provision, section 112(c)(6).
That provision is obviously intended to ensure controls for specific
persistent, bioaccumulative HAP, and this purpose is served by a
reading which compels regulation under section 112(d)(2) only of the
HAP for which a source category is listed under section 112(c)(6),
rather than for all HAP.
The facts here support the reasonableness of EPA's approach. Gold
mine ore processing is an area source category listed under section
112(c)(6) for regulation under section 112(d)(2) solely due to its
mercury emissions. There is special statutory sensitivity to regulation
of area source categories in section 112. For example, an area source
category may be listed for regulation under section 112 if EPA makes an
adverse effects finding pursuant to Section 112(c)(3) or if EPA
determines that the area source category is needed to meet its section
112(c)(3) obligations to regulate urban HAP or its section 112(c)(6)
obligations to regulate certain persistent bioaccumulative HAP.
Therefore, unless an area source category emits a section 112(c)(3)
urban HAP or a section 112(c)(6) HAP and EPA determines that such
category is needed to meet the 90 percent requirement set forth in
section 112(c)(3) and (c)(6), findings related to adverse human health
or environmental effects are required before EPA can regulate that area
source category--findings EPA is unable to make for non-mercury HAP
emitted from the gold mine ore processing and production source
category at this time. Moreover, to the extent EPA lists an area source
category pursuant to section 112(c)(3) (whether that finding is based
on adverse effects to human health or the environment or a finding that
the source is needed to meet the 90 percent requirement in section
112(c)(3), the statute gives EPA discretion to set generally available
control technology (``GACT'') standards for such sources. 42 U.S.C.
7412(d)(5).
EPA does not interpret section 112(c)(6) to create a means of
automatically compelling regulation of all HAP emitted by area sources
unrelated to the core object of section 112(c)(6), which is control of
the specific persistent, bioaccumulative HAP, and thereby bypassing
these otherwise applicable preconditions to setting section 112(d)
standards for area sources. Nor does National Lime address the issue,
since the case dealt exclusively with major sources.\3\ 233 F. 3d at
633. Consequently, EPA disagrees with the comment that it is compelled
to promulgate section 112(d)(2) MACT standards for all HAP emitted by
gold mine ore processors.
---------------------------------------------------------------------------
\3\ EPA acknowledges that major sources regulated under section
112 must be subject to MACT standards for all HAP emitted from the
source category consistent with National Lime.
---------------------------------------------------------------------------
3. Emission Standards for Fugitive Emissions
Comment: One commenter stated that gold mines have significant
fugitive emissions of mercury, but that EPA did not propose standards
for these emissions or mention them in its proposal. The commenter said
that EPA has a statutory obligation to set standards for gold mine
mercury emissions under section 112(d)(2) and (3), and must set
emission standards for all the mercury emissions from the listed
category. Another commenter described a recent preliminary study at two
facilities in Nevada that found fugitive mercury air emissions from
various non-point sources at those two mining operations such as from
leach pads and tailings ponds.
One commenter stated that means to control fugitive emissions are
available, such as enclosing their leaching operations. By enclosing
the leaching process, the commenter believes that mines could eliminate
this source of fugitive emissions. The commenter also stated that mines
should not send tailings into open tailing ponds, but into closed
treatment facilities that would remove mercury and other HAP from the
tailings and prevent their release to the air. The commenter
recommended that EPA evaluate the use of sulfur-based complexing agents
for removing mercury during cyanidization of gold. According to the
commenter, research indicates that these products appear useful for
substantially reducing mercury in process solution during heap
leaching.
Response: Due to the lack of information, we have not included
fugitive mercury emissions at gold mine facilities in our 1990 baseline
emission estimate (or in our more recent emissions estimates) for the
gold mine ore processing and production area source category.
Accordingly, these fugitive emissions are not part of the
[[Page 9458]]
source category we are listing and regulating in this final rule. Other
than the recent preliminary research at two facilities, we have no data
on fugitive mercury emissions at gold mine facilities. The recent
preliminary research suggests that some fugitive emissions may be
occurring at these facilities from large non-point sources such as
tailings ponds, leach fields and waste rock piles. However, it is our
understanding that this preliminary research has not yet been published
or peer-reviewed. Thus, at this juncture, we do not have sufficient
information on fugitive emissions.
Furthermore, we have very little information on how these fugitive
mercury emissions might be controlled. A few commenters suggested that
certain compounds were available that may be useful for limiting these
emissions. However, as far as we know, there has been no demonstration
that these compounds would work effectively to limit the emissions, and
we do not know the costs or potential adverse impacts of applying these
chemicals. Therefore, we question the feasibility and practicality of
applying these chemicals to limit fugitive mercury emissions from these
non-point sources. We also question the feasibility and practicality of
enclosing the leaching operations or the tailings ponds, as suggested
by some commenters.
As explained in the proposed rule, the gold mine ore processing and
production area source category covers the thermal processes that occur
after ore crushing, including roasting operations (i.e., ore dry
grinding, ore preheating, roasting, and quenching), autoclaves, carbon
kilns, electrowinning, preg tanks, mercury retorts, and furnaces. The
data and calculations used to derive the estimated 4.4 tons of mercury
emissions for this source category for the 1990 baseline inventory for
section 112(c)(6) reflect emissions from the thermal processes
described above, and the final MACT standards address all of these
processes.
4. Major Source Determination
Comment: One commenter noted that the proposal stated that the gold
mining processing and production source category consists of only area
sources; however, the proposal indicated that actual emissions of
hydrogen cyanide (HCN) at a few facilities were near the major source
threshold. The commenter concluded that EPA violates both the CAA and
its own regulations by basing its evaluation of whether gold mines are
major sources on their actual emissions instead of their potential
emissions.
The commenter further noted that the proposal requested comment on
a certification process that would allow gold mines to avoid major
source status whereby companies could certify that they are area
sources by implementing certain ``management practices'' and then
certifying to EPA that they had done so. The commenter stated that such
a certification process would be unlawful in calculating a sources
``potential to emit'' because the management practices are not
``control equipment,'' ``restrictions on hours of operation or on the
type or amount of material combusted, stored, or processed,'' and would
not be ``federally enforceable.''
Other commenters supported EPA's conclusion and determination that
the gold mines are area sources of HAP. According to the commenters,
EPA's methodology in making this determination was extremely
conservative because EPA did not apply what the commenters believe to
be a key correction factor. Application of this correction factor would
have reduced the HCN emissions estimates from by approximately 40-50%.
The commenters also stated that fence line testing at selected gold
mine operations demonstrated that these levels of HCN were below all
applicable public health standards.
The commenters believe that, because the gold mines are area
sources of HCN, they should not be subject to section 112 work practice
standards or newly developed certification requirements. The commenters
noted that it is not technically practical to set systematic work
practice standards to reduce HCN emissions for every gold mining
operation to follow because each mine is unique in its mineralogy and
cyanide leaching processes, and different process solution pH values
are necessary to enhance gold recovery.
The commenters explained that for economic, health, and safety
reasons, they already implement work practice standards designed to
minimize HCN. The commenter concluded that the combination of these
work practice standards and the annual TRI reporting more than
adequately ensure that gold mining operations will remain area sources
of HCN.
Response: Contrary to the assertions of one of the commenter's, EPA
did not state in the preamble to the proposed rule that the sources at
issue had actual emissions ranging from 5 to 9 tons. By contrast, EPA
stated that ``a few facilities are close to the major source threshold
due to hydrogen cyanide (HCN).'' 75 FR 22479. EPA failed to clarify in
the preamble to the proposed rule that the range of 5 to 9 tons
represented potential to emit calculations for the largest-emitting
sources. Specifically, as explained in the document ``Estimated
Emissions of HCN from Gold Mine Facilities in the U.S.'' (which is
available in the docket for this rulemaking), EPA estimated the
potential to emit for the five largest sources assuming that these
sources would be operating every day of the year, 24 hours a day, at
100 percent of its current capacity. These assumptions and calculations
resulted in a potential to emit estimate of 5 tons of HCN per year for
the largest source. EPA then completed a second set of calculations,
using the same assumptions (i.e., operating every day of the year, 24
hours a day, at full capacity), but without applying the surface area
correction factor, and those calculations resulted in a conservative
potential to emit estimate of 9 tons of HCN per year for the largest
source. The emission estimates for the remaining large facilities were
all below 9 tons.
The commenters correctly point out that in determining whether a
source is a ``major source'' under CAA section 112, we must consider
the source's potential to emit, as well as its actual emissions. See
CAA section 112(a)(1) and 40 CFR 63.2. As noted above, we specifically
examined the sources' potential to emit and concluded that all sources'
potential to emit were below the major source thresholds.
Some commenters allege that EPA significantly overestimated HCN
emissions from the larger sources by not accounting for certain
correction factors. They assert that if one were to account for the
appropriate correction factors in developing the potential to emit
values, HCN emissions would ``range from 3.7-4.5 tpy for the larger
mines compared to the 5-9 tpy estimate'' (See document titled ``PTE
Emission Estimates for HCN'' by the Nevada Mining Association, which is
available in the docket for this action). Other commenters make a
blanket, unsupported assertion that the Agency has underestimated HCN
emissions from the source category because they believe that without
the management practices currently employed by sources in the category,
HCN emissions would exceed the major source thresholds at the larger
sources. These latter commenters, however, made only conclusory
statements and did not demonstrate that HCN emissions from the larger
sources would exceed the major source thresholds if the management
practices were not employed.
[[Page 9459]]
In sum, EPA has developed conservative estimates of the sources'
potential to emit HCN. At one end of the range EPA estimates potential
emissions of 5 tons per year of HCN for the largest source, which is
well below the major source threshold of 10 tons per year of a single
HAP. At the other end of the range EPA estimates potential emissions of
9 tons per year for that same largest source, which is a conservative
estimate and is still below the major source threshold. The emission
estimates for the remaining large facilities were all below 9 tons. We
understand that the sources at issue implement various management
practices as part of their operations to minimize the use and emissions
of cyanide to protect workers, to comply with Mine Safety and Health
Administration (MSHA) standards, to comply with their agreements to the
International Cyanide Code, and for economic reasons (to reduce
operational and supply costs). We currently do not have sufficient
information to explicitly quantify emissions reductions achieved
through these management practices, but nothing in the record suggests
that the facilities would be major sources if they failed to employ the
management practices. Accordingly, we are taking final action today to
list the gold mine ore processing and production area source category
and regulate its mercury emissions pursuant to CAA section 112(c)(6).
Although not required, we intend to send letters to various Gold
Mining Processing and Production companies pursuant to Section 114 of
the Clean Air Act to confirm our conclusion that the sources' potential
to emit remain below major source thresholds.
5. Title V Permit Exemption
Comment: In the proposal preamble, EPA solicited comment on whether
a title V exemption ``is appropriate under section 502(a) for any
particular sources in this category.'' One commenter offered the
following reasons for not exempting gold mines from title V permitting
requirements:
EPA did not properly determine whether some or all sources
in the category are major sources by determining each source's
potential to emit.
The CAA allows EPA to exempt area sources from title V
permitting only if it establishes that compliance with the title V
permitting requirements would be ``impracticable, infeasible or
unnecessarily burdensome.'' However, EPA does not claim that such
requirements are ``impracticable,'' ``infeasible,'' or ``unnecessarily
burdensome'' for gold mines.
It is feasible and within the gold mining companies'
financial means to comply with title V permitting requirements.
The commenter believes that the text and legislative history of the
CAA make plain that Congress intended ordinary citizens to be able to
get emissions and compliance information about air toxics sources and
to be able to use that information in enforcement actions and in public
policy decisions on a State and local level. According to the
commenter, Congress did not think that enforcement by States or other
government entities was enough; if it had, Congress would not have
enacted the citizen suit provisions. The commenter said that, if a
source does not have a title V permit, it is difficult or impossible
for a member of the public to obtain relevant information about its
emissions and compliance status or to bring enforcement actions. The
commenter stated that to the extent the informational and enforcement
benefits provided by title V permits can be considered a burden, these
benefits far outweigh that burden.
The commenter also noted that title V provides important monitoring
benefits and that title V permits are necessary to provide adequate
monitoring. The commenter concluded by stating that the legislative
history of the CAA shows that Congress did not intend EPA to exempt
source categories from compliance with title V unless doing so would
not adversely affect public health, welfare, or the environment;
however, exempting gold mines from title V would adversely affect
public health, welfare and the environment by depriving the public of
important informational and enforcement benefits.
One State agency commented that additional title V permitting would
subject both the source and the State agency to additional resource
burdens. The commenter points out that major sources of criteria
pollutant emissions are currently subject to title V permit
requirements in Nevada and that sources not subject to major source
permitting requirements are subject to Nevada's minor source permitting
program. In addition, the NMCP requires all mining sources to obtain
mercury-specific operating permits to construct. The commenter believes
that these permit programs would provide a strong basis for
implementing and enforcing any Federal MACT requirements for the gold
mining industry, and there would be nothing gained by subjecting these
sources to title V permitting.
Several commenters stated that EPA should exercise its discretion
and exempt the gold mine ore processing and production industry from
the title V requirements as impracticable, infeasible, and
unnecessarily burdensome. The commenters said that, in light of EPA's
findings in other similar rulemakings for area sources, the four
factors set forth in the Exemption Rule support a finding that title V
permitting is ``unnecessarily burdensome'' for the gold mine ore
processing and production area source category.
In discussing the first factor of the Exemption Rule, whether title
V would result in significant improvements to the compliance
requirements, the commenters said that the proposed NESHAP for the gold
mine ore processing and production area source category includes
extensive monitoring, recordkeeping, and reporting requirements that
are more comprehensive than title V requirements. The commenters
believe that Nevada regulations and permits provide an additional layer
of compliance assurance on the Federal NESHAP that obviates the need
for title V permitting. The commenters claimed that the additional
layering of title V does not ``significantly improve'' upon the
proposed and existing compliance requirements.
Regarding the second factor in the Exemption Rule, whether title V
permitting would impose significant burdens on the area source category
and whether the burdens would be aggravated by any difficulty the
sources may have in obtaining assistance from permitting agencies, the
commenters said that there are extensive administrative burdens and
costs associated with the title V permitting process, including
mandatory activities that have been previously identified by EPA. The
commenters claimed that many of the area source gold mines are owned
and operated by small entities that are already required to comply with
comprehensive State permitting requirements for mercury emissions and
that requiring title V permits for them would result in resources being
redirected away from more useful and necessary efforts.
The commenters explained that the third factor in the Exemption
Rule examines whether the costs of title V permitting for the area
source category would be justified, taking into consideration any
potential gains in compliance likely to occur for such sources. The
commenters claim that there do not appear to be any gains in compliance
to justify the additional costs that would be imposed on these area
sources from title V permitting
[[Page 9460]]
based on the lack of significant improvements in compliance
requirements and the substantial additional costs and burdens
associated with title V compliance.
The commenters noted that the fourth factor in the Exemption Rule
analysis is whether there are implementation and enforcement programs
in place that are sufficient to assure compliance with the NESHAP for
the area source category, without relying on title V permits. The
commenters claimed that the proposed rule includes all necessary
monitoring to effectively implement its requirements, and the area
sources for the gold mine ore processing and production are already
permitted under State permit programs. According to the commenters, all
non-title V sources in Nevada are required to hold ``Class II''
operating permits that must contain, among other things, all applicable
emission limitations and standards. The commenters said that other
States where gold mine ore processing and production area source are
located either would be covered by a comparable delegated State air
program or by EPA.
The commenters stated that EPA regularly provides title V
exemptions for area sources similar to gold mine ore processing and
production area sources and cited examples from the past year. The
commenters claim that the existing and proposed compliance and
monitoring requirements for the gold mines are generally more stringent
than those found in the other NESHAPs for which EPA has granted a title
V permit exemption.
The commenters stated that exempting the gold mine ore processing
and production area source category from title V permitting will not
adversely affect public health, welfare, or the environment because
title V permits do not generally impose substantive air quality control
requirements. According to the commenters, requiring title V permits
also carries the potential of adversely affecting public health,
welfare, or the environment by shifting State agency resources away
from ensuring compliance with a program that is reducing mercury
emissions from gold mines.
The commenters stated that EPA should exempt the gold mine ore
processing and production area source category from title V permitting
requirements, and at a minimum, should exempt area source gold mines
that are subject to Nevada's comprehensive mercury control program.
Response: After reviewing the comments, we continue to believe that
it is appropriate that all gold mine ore processing and production
facilities be required to obtain title V permits. Most of the other
area source categories for which we have provided title V permit
exemptions have hundreds or thousands of facilities that are mostly
owned by small businesses. In contrast, there are an estimated 21
facilities that are subject to this final rule, and, based on our
research and analyses, none of the facilities are owned by small
businesses; most of these facilities are owned by large, and in some
cases, multi-national, corporations. Therefore, we conclude that the
argument of financial burden, which has supported title V exemption for
other source categories, does not apply to the gold mining industry
(see Economic and Small Business Analysis, which is available in the
docket).
Currently, it is our understanding that 7 of the 21 facilities that
will be subject to the final rule already have title V permits (5 in
Nevada and 2 in other states). Further, there are approximately 5
facilities in all other States (i.e., except Nevada) that do not
currently have title V permits that will be subject to this final rule,
so title V permitting will apply to no more than a few facilities in
any one of these other States. Therefore, we do not believe the
requirement for title V permitting will be overly burdensome to the
permitting authorities in those States. Although there are more
facilities in Nevada that will be subject to the final rule, as the
commenters point out, Nevada already has an effective permitting system
in place. Five of the 14 gold mine facilities in Nevada already have
title V permits. Because of Nevada's existing permitting system and
experience with title V permitting, we do not think that it is an undue
burden on the State of Nevada to require title V permits from the other
gold mine facilities located within the State. We also think it is
important for the public in States where these facilities are located
to have access to emissions and monitoring data and the opportunity for
public involvement in the permitting of these facilities that is
provided by title V permitting.
6. Reconstruction
Comment: Several commenters believe it is appropriate to group
under each of the umbrella ``affected sources'' all the equipment
associated with each particular process in order to ensure a reasonable
application of the reconstruction provisions found in the General
Provisions. The commenters asked that EPA reaffirm that the 50 percent
fixed capital cost trigger for determining reconstruction would be
measured against all equipment components needed for the defined
processes, and that reconstruction at one affected source as defined in
the standard will not affect or result in reconstruction at another
affected source.
The commenters also noted that the definition of ``reconstruction''
authorizes EPA to establish special provisions in a particular standard
for the application of the reconstruction criteria to the affected
source. The commenters said that the ``carbon processes'' affected
source illustrates that the affected source can consist of several
pieces of interconnected equipment that together constitute the process
line, and it can be anticipated that production needs will give rise to
the need to add more pieces of equipment to an existing carbon process
line or even to install a whole new carbon process line. The commenters
provided three examples: Adding a new component to an existing carbon
processes group; construction of a new carbon group due to expansion at
a facility that has an existing carbon group; and installation of new
pollution control equipment. The commenter said that consideration of
whether or where new MACT requirements should apply in these examples
warrants the development of special reconstruction provisions in this
standard, or EPA should clarify that the three examples would not be
considered reconstruction under the proposed rule.
The commenters asked that EPA either clarify that the three
examples would not be considered reconstruction, or alternatively, add
the following provisions to the proposed rule: (1) An addition of a new
piece of equipment to address production requirements is not considered
a reconstruction, (2) the expansion of a facility by the construction
of a completely new process line will not be considered a
reconstruction of an existing process line, and (3) the installation of
air pollution control equipment to comply with this standard is not
considered a reconstruction.
Response: The determination of what constitutes a reconstruction is
directly tied to the definition of the affected source and the
definition of reconstruction in the part 63 General Provisions:
Reconstruction, unless otherwise defined in a relevant standard,
means the replacement of components of an affected or a previously
nonaffected source to such an extent that:
(1) The fixed capital cost of the new components exceeds 50
percent of the fixed capital cost that would be required to
[[Page 9461]]
construct a comparable new [affected] source; and
(2) It is technologically and economically feasible for the
reconstructed source to meet the relevant standard(s) established by
the Administrator (or a State) pursuant to section 112 of the Act.
Upon reconstruction, an affected source, or a stationary source that
becomes an affected source, is subject to relevant standards for new
sources, including compliance dates, irrespective of any change in
emissions of hazardous air pollutants from that source.
For each of the four affected sources in the final rule, we have
defined the affected source as the collection of processes associated
within each affected source. Consequently, if one process within the
affected source is upgraded or replaced with a new process, the 50
percent fixed capital cost criterion would be based on the fixed
capital cost of replacing all processes in the affected source, not
just the capital cost of the process being upgraded or replaced. For
example, if a new carbon kiln is added to an existing group of carbon
processes with mercury retorts, the capital cost of the new carbon kiln
would be divided by the fixed capital cost of constructing a comparable
new affected source containing all of the processes within the existing
affected source of carbon processes with mercury retorts to calculate
the percent for comparison to the 50 percent criterion.
With regard to the scenario where a new carbon process with a
mercury retort is installed, the affected source is defined as the
collection of all applicable processes within the affected source, and
because of this, a facility could not have two carbon processes with
mercury retorts affected sources, such as the commenter suggested,
where one group is new and the other is existing. For example, if a new
group of carbon processes with mercury retorts is installed at a
facility in addition to an existing group of carbon processes with
mercury retorts, the two groups (all carbon processes with mercury
retorts at the facility) collectively would be a single affected
source. In this case, the fixed capital cost criterion would be based
on the fixed capital cost of replacing the existing affected source
with a comparable new affected source, and if the new processes exceed
50 percent of that cost, all of the carbon processes with mercury
retorts would be subject to the new source limit for carbon processes.
There would not be separate and different emission standards for the
two sets of carbon sources with mercury retorts (the older group and
newer group) because the collection of all of these processes is the
affected source.
We do not see a necessity to provide criteria for this final rule
that are different from the requirements in the General Provisions for
determining what constitutes a reconstruction. We also think it is
appropriate to exclude the cost of emission control equipment from the
cost calculation for reconstruction determinations.
B. Applicability
Comment: Several commenters stated the rule should exempt
individuals (prospectors), laboratories, small mining operations, and
non-leaching operations. The commenters urged EPA to include in the
final rule all of the following exemptions to avoid the problem of
unintended regulation of sources that were not meant to be included in
the source category: Gold mining operations that produce less than 100
pounds of concentrate per year, which would exempt analytical labs that
perform small bench scale processing tests on gold ores; gold mining
operations that do not leach or dissolve gold, which would exempt
placer and other non-leaching operators, including both small
commercial efforts as well as individual recreation-type prospectors;
and gold mining operations that process less than 1,000 tons per year
of gold ore, which would exempt certain small scale pilot plants and
related testing operations. The commenters said that the exemptions
suggested above will not reduce in any way the effectiveness of the
proposed rule in controlling mercury emissions from the targeted larger
mines, nor will they lead to increased mercury emissions, but they will
exclude regulation of a large number of small operators who do not emit
any significant mercury.
Response: Section 63.11640(c) of the proposed rule provides that
the emissions standards for this area source category do not apply to
research and development facilities, as that term is defined under CAA
section 112(c)(7). We did not receive any adverse comments concerning
this provision, and are finalizing the provision in this rule.
Further, as mentioned above in section IV, we are clarifying in
this final rule that this area source category does not include
individual prospectors and very small pilot scale mining operations.
Prospectors and other very small pilot-scale operations (e.g.,
operations that produce or process less than 100 pounds of concentrate
per year) are very small and were not included in the section 112(c)(6)
inventory that was the basis for the listing of gold mine ore
processing and production source category. We believe that emissions
from the very small scale operations described above to be very
minimal.
By contrast, the commenter's suggested 1,000 tons/yr ore threshold
may include operations beyond the very small scale pilot operations
discussed above. We believe that the 100 pounds of concentrate per year
more appropriately reflect these very small scale operations.
We are not making the suggested change of excluding operations that
do not leach or dissolve gold because certain gold mine facilities in
the source category use flotation or gravity flotation processes and
perform thermal processing of concentrate in melt furnaces, which can
have significant emissions of mercury. However, as mentioned above we
are clarifying that this final rule does not apply to these very small
scale operations.
C. MACT Floors
1. Consideration of Variability in Determining Floors
Comment: One commenter acknowledged that EPA may consider
variability in calculating the best sources' performance, but stated
that EPA's method of considering variability seeks to assure that none
of the sources among those identified as best performers would ever
exceed the floor level. The commenter claims that such an approach
ignores the reality that sources' emission levels are largely within
their control, and although a great deal of variability may be
statistically conceivable if EPA chooses a high enough prediction limit
(in this case the 99th percentile) that does not mean that a well-
operated source actually would experience such variability. The
commenter said that one of the main points of having emission standards
is to ensure that sources not only deploy the appropriate control
measures, but also use those control measures consistently to minimize
emissions.
The commenter said that using an upper prediction limit to set
standards reflecting the statistical worst performance these sources
could have in a purely statistical sense does not yield an accurate
picture of the best sources actual performance, and it is especially
arbitrary in the absence of any explanation of why EPA thinks that the
relevant best sources' performance would ever be so bad, other than the
fact that it is statistically possible.
Response: As described previously, the MACT floor limits are
calculated based on the performance of the lowest
[[Page 9462]]
emitting sources in each of the MACT floor pools. We ranked all of the
sources for which we had data based on their emissions and identified
the lowest emitting sources.
As the commenter concedes, EPA can consider variability in
assessing sources' performance when setting MACT standards. See Brick
MACT, 479 F.3d at 881-82; and Mossville Envt'l Action Now v. EPA, 370
F.3d 1232, 1241-42 (D.C. Cir 2004) (reaffirming that EPA can assess
variability in determining the level of emissions control achieved by
the best performing sources).
Variability in facilities' performance has various causes. One
source of variability for these facilities is the differing mercury
concentrations in the input materials. Another source of variability is
due to normal variations in performance of the control devices for
which both run-to-run and test-to-test variability must be
accounted.\4\ A review of the run-by-run emissions data in the record
shows that emission rates from one run to the next for well-operated
sources can vary by as much as a factor of 8. We need to account for
sources' variability (both due to control device performance and
variability in inputs) in assessing sources' performance when
developing technology-based standards. Accordingly, EPA accounts for
variance in test data, between units, and among facilities when
developing the MACT standard.
---------------------------------------------------------------------------
\4\ Run-to-run variability is essentially within-test
variability, and encompasses variability in individual runs
comprising the compliance test, and includes uncertainties in
correlation of monitoring parameters and emissions, and imprecision
of stack test methods and laboratory analysis. 72 FR at 54877 (Sept.
27, 2007). Test-to-test variability results from variability in
pollution device control efficiencies over time. Test-to-test
variability can be termed long-term variability. 72 FR at 54878.
---------------------------------------------------------------------------
In determining the MACT floor limits, we first determine the
average emissions of the top performers based on available data. We
then assess variability of the best performers by using a statistical
formula designed to estimate a MACT floor level that is equivalent to
the average of the best performing sources based on future compliance
tests. Specifically, the MACT floor limit is an upper prediction limit
(UPL) calculated with the Student's t-test. The Student's t-test has
also been used in other EPA rulemakings (e.g., NESHAP for Cement
Manufacturing, NSPS for Hospital/Medical/Infectious Waste Incinerators,
and NESHAP for Industrial, Commercial, and Institutional Boilers and
Process Heaters) in accounting for variability. A prediction interval
for a future observation is an interval that will, with a specified
degree of confidence, contain the next (or some other pre-specified)
randomly selected observation from a population. In other words, the
prediction interval estimates what the upper bound of future values
will be, based upon present or past background samples taken. The UPL
consequently represents the value which we can expect the mean of
future observations (i.e., emission test runs) to fall below within a
specified level of confidence, based upon the results of an independent
sample from the same population. In other words, if we were to randomly
select a future test condition from any of these sources (e.g., average
of 3 runs) we can be 99 percent confident that the reported level will
fall at or below the 99 percent UPL value. We note that the methodology
accounts for both short-term and long-term variability and encompasses
run-to-run and test-to-test variability.
For this rule, we used the 99 percent UPL analysis on the emissions
data for the top performing sources to account for the variance. In the
context of determining the MACT floor, the 99 percent UPL represents
the value below which the mean of future compliance tests (based on,
for example, a 3-run average) would fall 99 percent of the time. A 99
percent level of confidence means that a facility, whose emissions are
consistent with the best performing sources, has one chance in 100 of
exceeding the emission standard.
We believe that using the 99 percent UPL is appropriate for this
rule. As noted above, this approach is consistent with several other
previous rulemakings. It also makes sense from a practical standpoint.
If we selected a lower number (e.g., 95 percent UPL) this would mean
that a best performing source that is performing at the MACT level of
control would potentially exceed the limit 5 percent of the time--which
we do not believe is a reasonable approach for this rule. See
Mossville, 379 F.3d at 1241-42); see also 70 FR at 59438 (Oct. 12,
2005) (explaining use of 99th percentile). With regard to the
commenter's statement that no sources among the best performers would
ever exceed the MACT standard, we believe this is incorrect. The
commenter provided no basis for this statement, and we do not believe
the commenter based this statement on an analysis of the variability in
the data.
We do not believe that the UPL analysis reflects the statistical
worst performance the top five performing sources could have. The UPL
calculation is dependent on the data that we have, and reflects the
actual variability in the test data for the best performing sources. It
does not reflect worst-case performance. We continue to believe that
the UPL does yield an accurate picture of the best sources' performance
as best as possible with taking into account variance between the
facilities, units at the facilities, and between test runs for the
different units (including variability in input materials).
Furthermore, although the average of several data sets may show a
top performing source meeting the emission standard by a significant
margin, the variability in emissions inherent in any one compliance
test could easily indicate much higher emissions, and, in some cases,
an exceedance of the emission standard. We continue to believe that the
UPL analysis evaluated at 99 percent confidence is appropriate for this
source category.
Moreover, we believe the data we used to calculate the MACT
standards are representative of the normal performance of the best
performing sources for several reasons. First, the test results that we
are using in our MACT database are tests conducted under Nevada's
mercury emission control program, and are conducted to determine
whether a facility is in compliance with State requirements. Facilities
typically try to perform as well as they can during such tests. State
(and often EPA) permitting authority staff are notified before a
performance test is conducted to provide an opportunity to attend and
observe the test, and they often attend to ensure the source is
operating properly and that the testing is performed according to the
strict requirements in the codified test methods.
Test reports are carefully reviewed by the permitting authority,
and any failure to follow the test method or abnormal operation of a
source is flagged. These data are usually invalidated, and invalidated
tests are not used in our MACT standard calculations. For example,
several tests from these facilities were invalidated by the NDEP
because the specified testing procedures were not followed or the
emission control device was not operating properly, and we have not
used those results in our analysis for those reasons. We have collected
additional data from test reports not available at the time of
proposal, and one of those tests was invalidated because NDEP
representatives discovered that the emission control device was not
operating properly during the test. Therefore, we also did not use
those test data.
The commenter believes that floors must be set at the average
emission level
[[Page 9463]]
achieved by the best performers when they are operating properly. We
agree that the performance data characterizing the emission level
achieved by the top performers must be data obtained when they are
operating properly, and we believe that is the case for our current
database for this source category.
As described above, the MACT floor is based on the average
performance of the top performers plus an amount to account for
variability. We have appropriately developed a MACT standard based on
emissions from the top 5 best performing sources that accounts for
variability because, over an extended period of time, the emissions
from each of these best performing facilities (even the best
controlled) will vary above and below the facility average. For
example, we expect that about half of the duration of the year the
emissions from a best performing facility would be somewhat below their
average and that about half of the duration of the year their emissions
would be somewhat higher than their average. If we set the MACT limit
exactly equal to the average emissions level achieved by the best
performers (without accounting for variability), and we had a source
that was performing at exactly the MACT level over the course of the
year, the measured emissions level on roughly half the days of the year
would suggest that the source is emitting at levels above the MACT
limit, and on about half of the other days of the year the measured
emissions level would suggest that the source is emitting at levels
less than the MACT limit. We reasonably and appropriately accounted for
variability in the data consistent with established statistical theory
and practice and judicial precedent. Finally, ignoring variability of
the best performing sources and using only the average performance
would virtually guarantee that some of even the best performers would
exceed the floor limit at least some of the time.
Thus, we developed a MACT standard based on the average of the best
performing sources that accounts for variability. We accomplished this
by calculating the MACT standard from this average performance and
accounting for variability by using the 99 percent UPL. The specific
calculations are presented in the MACT floor document in the docket for
this rulemaking. Furthermore, we agree with the comment that one of the
points of having emission standards is to ensure that sources not only
deploy the appropriate control measures, but also use those control
measures consistently to minimize emissions. We believe that the MACT
standards established in this rule along with the requirements to
monitor and maintain control device parameters within certain ranges
will ensure control measures are applied consistently to minimize
emissions.
Comment: Another commenter stated that consideration should be
given to defining the inherent range of measurement error and requiring
more test runs in order to reduce variability due to process variation.
The commenter said that this would also better clarify when variability
was due to operational controls, which could be addressed, rather than
due to factors that cannot be controlled, such as mercury content in
the ore. The commenter asked for clarification on how inconsistent runs
should be treated, what defines an acceptable set of runs, and at what
point more runs would be required to provide reliable data.
The commenter also stated that the degree of variability allowed in
the development of the new source limit for ore pretreatment appears to
be out of line with the new source limits for carbon processes and non-
carbon processes. The commenter believes that ore pretreatment
variability for new sources is higher than existing sources because low
thermal units were included in the same category, high emissions were
allowed in the data set, and variable emissions were allowed in data
set. The commenter recommended that, if EPA continues to use Goldstrike
as the best performing source for new source MACT, then they should re-
evaluate and reduce the variability to be equal to or less than the
variability for existing sources.
Response: We agree with the commenter that the testing process
would be more accurate if the number of test runs was increased.
However, we balance several factors in determining the minimum number
of runs required, and because the compliance testing is supplemented by
various types of continuous or periodic parametric monitoring, we have
concluded that three test runs are appropriate for this final rule.
Although we have not proposed a formal procedure to assess the
consistency of test runs, the permitting authority performs routine
reviews of compliance test data to identify potential outliers and
results that suggest further investigation is needed. For example, a
routine review tracks trends in performance, and in particular, flags
any trends in deteriorating performance over time. An unusually high
run among the three runs also attracts attention and would be examined
to determine if it might have been caused by a problem with the
process, control device, sampling, or analysis. If the permitting
authority identifies inconsistent runs, they have the authority to
invalidate any or all runs. A source would be required to perform more
runs to provide reliable data if two to three runs were invalidated.
We agree with the commenter that the degree of variability used in
the development of the proposed new source MACT standard for the ore
pretreatment group appeared to be inconsistent with the degree of
variability used in the development of the proposed new source MACT
standard for carbon processes and non-carbon concentrate processes. We
agree with the commenter that the ore pretreatment degree of
variability at proposal for new sources was higher than the degree of
variability for existing sources. We do not believe that the
variability was higher because low thermal units (i.e., autoclaves)
were included in the same category, but because two tests of the ore
preheater/dry grinding processes at Goldstrike were allowed in the data
set. These tests had, as the commenter identified, inconsistently high
emissions (as compared to other tests at other times for the same
units) and inconsistent variability between the runs. We have
determined that the tests the commenter is referring to are not
representative of normal operation, and those tests have been removed
from our database because the NDEP invalidated the tests due to
possible sample contamination. (See the MACT Floor Document in the
docket for the final rulemaking for more details). We continue to use
Goldstrike as the best performing source for the ore pretreatment new
source MACT, and the variability for new source MACT is now less than
that of the variability for existing source MACT, and is less than the
variability calculated at the time of proposal.
2. General Comments on MACT
Comment: Some commenters stated that the MACT floor already
represents installation and operation of MACT controls, and the use of
emissions data from facilities that are already controlling their
mercury emissions creates an artificially low MACT floor. The
commenters said that the low MACT floor penalizes facilities that
voluntarily invested in pollution control technology and creates a
substantial disincentive for industry and States to move ahead of EPA
in reducing emissions of HAP.
Response: We acknowledged at proposal that many gold mine
facilities are already well controlled for many
[[Page 9464]]
reasons, including participation in the NMCP. We also acknowledge that
the top performing facilities that are the basis for the MACT floor
calculation are the top performers because they have installed
controls. CAA section 112(d)(3)(B) requires that, for a category with
fewer than 30 sources, the MACT floor not be less stringent than ``the
average emission limitation achieved by the best performing 5 sources
(for which the Administrator has or could reasonably obtain emission
information).'' (Emphasis added). EPA has information on the well-
controlled facilities and used the information to conduct MACT floor
analysis, as required by the CAA. Although the MACT floor may be
considered more stringent in comparison to floors that would have been
established if no facilities had mercury emission controls, we do not
consider the floor to be ``artificially low'' because consistent with
the statute, it reflects the level achieved in practice by the best
performing sources. See 112(d)(3). We do not believe that the MACT
floor penalizes facilities that invested in pollution control
technology because those facilities will be able to meet the MACT
standards. We do not consider that this final rule creates a
disincentive for industry and States to move ahead of EPA in reducing
HAP emissions because as facilities reduce mercury emissions by adding
controls required by State programs, they will be able to meet the
NESHAP. Most of the facilities that will not meet the current final
standards have already proposed to add controls to their units in their
Phase 2 applications for the NMCP.
3. MACT for the Ore Pretreatment Group
Comment: Several commenters supported EPA's general approach to
establish three groups of affected sources in the proposal. On the
other hand, several commenters suggested that EPA develop separate
emission standards for roasters and autoclaves for existing and new
sources. One commenter stated that roaster and autoclave processes are
different from each other based on the mercury species released,
controls utilized, and their rates of mercury emissions. The commenter
said that roasters commonly reach temperatures of 400[deg] to
700[deg]C, releasing gaseous elemental mercury, whereas autoclaves
commonly reach temperatures of 175[deg] to 230[deg]C producing reactive
gaseous mercury and sulfate and forming mercury sulfate. According to
the commenter, autoclaves are expected to be able to improve efficiency
over time. The commenter noted that roasters produce one to two orders
of magnitude higher emissions than do autoclaves. The commenter
believes that facilities that only use autoclaves should not be allowed
the leeway to emit at the rate that facilities employing roasters are
allowed. The commenter recommends that the ore pretreatment group be
divided into high temperature pretreatment processes (roasters) and low
temperature pretreatment processes (autoclaves and ancillary roaster
processes, such as dry grinding, pre-heating, and quenching).
Response: We discussed in section V.A. of the preamble to the
proposed rule our rationale for establishing the different affected
sources, including the ore pretreatment processes affected source. We
believe it is appropriate to maintain the ore pretreatment group
affected source, as we had proposed. We do not agree with the comment
that roasters necessarily have higher emissions that are one to two
orders of magnitude higher than emission from autoclaves. The available
data show a wide range in emissions from autoclaves (from 0.4 to 115
lb/million tons of ore). This range overlaps the range for roasters and
their ancillary equipment, which have combined emissions between 42 to
71 lb/million tons of ore. Regardless of the mercury species released,
controls utilized, operating temperatures, or control efficiency over
time, autoclaves and roasters process the same input material (i.e.,
ore) and are intended for the same purpose (i.e., to oxidize the ore).
Therefore, we believe that it is appropriate to maintain the ore
pretreatment affected source as we had proposed, keeping roasting
operations and autoclaves together.
Comment: One commenter stated that EPA failed to consider beyond-
the-floor standards for roasters and that if additional reductions are
achievable at roasters, then EPA must set additional beyond-the-floor
standards for roasters.
A commenter also stated that although EPA's standard for new ore
pretreatment facilities is as high as its standard for existing
facilities, EPA does not propose or discuss setting beyond-the-floor
standards for new sources. The commenter claims that EPA has a
statutory obligation to ensure that its new source standards reflect
the maximum achievable reduction in emissions.
Response: Following proposal, we continued to investigate the
performance of facilities with ore pretreatment processes and
opportunities for additional control. We collected data from more
recent tests that were not available at proposal, and these new data
show that emission control performance at these facilities has
continued to improve. We identified two previous tests in the proposal
database that were suspect, and we confirmed with NDEP that these tests
should be invalidated and not used in the analysis because of possible
sample contamination. We have also dropped the data for one facility
from the analysis because their autoclave was shutdown in 2007 and
dismantled, and we only had one test of the autoclave when it was
operating in 2006. For these reasons, we did not include data for that
facility in the analysis, which is now based on the only four
facilities currently operating.
Based on the addition and change described above with respect to
our available data, we revised the MACT floor analysis for the ore
pretreatment processes. The revised MACT floor for existing sources
decreased from 175 lb/million tons at proposal to 158 lb/million tons,
and the new source MACT floor dropped from 163 lb/million tons to 84
lb/million tons.
The MACT floor limit for existing ore pretreatment processes is
based on the use of calomel-based mercury scrubbers on roasters and wet
scrubbers on autoclaves and ancillary roaster operations. We conducted
a beyond-the-floor analysis during the development of the proposed
rule. The roasters were already equipped with very good mercury
controls (condensers and calomel-based mercury scrubbers), and we did
not identify any beyond-the-floor options for the roasters. However, we
identified as a beyond-the-floor control for autoclaves the
installation of both a refrigeration unit (or condenser) and a carbon
adsorber. We continue to believe that the roasters stacks are well
controlled, but since our proposal, we have identified a beyond-the-
floor control option (carbon adsorption) for the ore pre-heaters/dryers
(ancillary roaster operation) that could achieve additional emissions
reductions of approximately 70 percent (or more) for those units. Two
of the three facilities with roasters have already proposed in their
NMCP Phase 2 permit applications to apply controls to their preheaters/
ore dryers, and these two companies have submitted cost estimates for
applying a carbon adsorption system. Using the cost estimates submitted
by the affected facilities, we estimate the capital costs for control
of roaster preheaters/dryers for the three facilities with roasters as
$3 million with a total annualized cost of $1.6 million per year. We
also estimate a reduction of 118 lb/yr of mercury emissions would be
achieved at an overall cost effectiveness of about $13,800 per pound of
mercury. We
[[Page 9465]]
believe that these costs and cost effectiveness are reasonable. As
required under CAA section 112(d)(2), we have also considered non-air
quality health and environmental impacts and energy requirements of
this additional control. We conclude that this is an acceptable beyond-
the-floor control technology for existing roaster preheaters/ore
dryers. Therefore, we included the beyond-the-floor control for ore
preheaters/dryers, as well as the beyond-the-floor control for
autoclaves, in determining the MACT standard in this final rule for
existing sources of ore pre-treatment processes. After applying the
appropriate variability analyses to the data, we determined that the
MACT standard for existing sources is 127 lb/million tons of ore.
As mentioned above, we have revised the new source MACT floor. We
also did a beyond-the-floor analysis for new sources in the ore pre-
treatment processes group. However, we did not establish the MACT
standard for new sources based on this beyond-the-floor analysis
because we did not identify a feasible and cost-effective option to
achieve reductions greater than the new source MACT floor. Therefore,
for new sources of ore pretreatment processes, the MACT ``floor'' is
the MACT standard for the affected source. The final new source MACT
standard is 84 lb/million tons of ore, which is considerably more
stringent compared to the proposed standard of 149 lb/million tons of
ore and reflects the maximum achievable reduction in emissions.
Comment: One commenter stated that the proposed estimated capital
costs of $890,000 and total annualized cost of $720,000 for beyond-the-
floor autoclave controls are not representative of actual costs of
installing a refrigeration unit (or condenser) and a carbon adsorber on
autoclaves. The commenter estimates that capital costs for autoclave
controls will range from $18 million to at least $30 million, and
annual operating costs could range from $2 million to $60 million,
depending on which controls, if any, are determined to be technically
feasible. The commenter believes that based on these cost estimates,
beyond-the-floor MACT controls would be cost prohibitive and are not
justified for the ore pretreatment affected source group.
Another commenter estimated that for the installation of carbon
adsorbers on their autoclaves to control mercury emissions, the capital
costs would range from $30 million to $35 million, annual operating
costs would be $2 million per year, and the annual energy requirements
would be 11,400 megawatt-hours per year with an annual energy cost of
$900,000.
Response: After reviewing the new cost estimates provided by the
commenters, we agree that capital and total annualized cost estimates
of the beyond-the-floor controls on autoclaves in the proposal were
underestimated. We evaluated the detailed cost estimate based on an
engineering study for a carbon adsorption system provided by one of the
commenters (see details in the comment above on capital, operating, and
energy costs), and our review of these details indicates it to be a
reasonable cost estimate and more representative. Therefore, we have
used this estimate as the basis for our estimate of the costs of the
beyond-the-floor mercury emission controls for autoclaves. Our revised
estimates are that the capital cost for installing carbon adsorbers on
autoclaves would be $29.3 million, with a total annualized cost of $4.9
million per year, which would result in an estimated reduction of 431
lb/yr of mercury emissions per year and an overall cost effectiveness
of about $11,000 per pound of mercury. Based on these new costs and
estimated reductions we conclude that the beyond the floor controls are
affordable and justified for the ore pretreatment affected source.
Comment: Several commenters noted that, at the proposed new source
MACT limit of 149 pounds/million tons of ore, the proposed new source
Donlin Creek Mine, located in Alaska, would be allowed to emit 3,200
lb/yr of mercury based on a projected production rate of 22 million
tons/yr of ore.
Response: With respect to this proposed new gold mine in Alaska,
the commenters' estimate of 3,200 lb/yr of mercury emissions is
inaccurate and a significant overestimate for a number of reasons. The
two primary reasons are that, based on available information, if the
facility is built, only an estimated 15 percent of the ore mined will
be processed in autoclaves (not 100 percent as assumed by the
commenters), and that the commenters' estimate is based on assuming
that the average emissions level for the facility throughout the year
would be at the maximum allowed at the proposed new source limit (149
lb/million tons of ore), which has been significantly reduced since
proposal.
With the new source MACT standard in the final rule that is about
two times more stringent (i.e., lower) than the proposed MACT standard,
along with corrections described above, we estimate that far less than
3,200 lb/yr would be emitted from this new source if it is ever built.
Assuming continuous operation for 365 days per year, an estimated 21.5
million tons/yr of ore mined, about 3.2 million tons/yr processed in
autoclaves (15 percent), and assuming the source would emit at the
average emission level used to calculate the revised new source MACT
(45 lb/million tons of ore), we calculate that mercury emissions would
be about 144 lb/yr, which is about 5 percent of the estimate provided
by the commenters. Considering that the facility has yet to go through
the permitting process and that, if it is built, it will likely include
emissions controls that would reduce the emissions below 45 lb/million
tons of ore, we believe that, if the facility is built, emissions would
quite likely be lower than 144 lb/yr.
4. MACT for Carbon Processes
Comment: Several commenters objected to including Facility M in the
MACT floor determination for new and existing sources in the carbon
processes affected source because it is not representative of, or
similar to, other sources, because it has unusually low mercury
concentrations in its ore, and no need for a retort to remove and
recover mercury. They noted that, because the mercury content of the
gold ore is fixed, the only way for other facilities to reduce
emissions of mercury is to apply mercury emission controls, but, for
many facilities, emission controls will not be enough to meet the
proposed MACT standard. The commenters stated they were aware that the
DC Circuit Court had constrained EPA's discretion to set floors that
fail to consider material inputs, but they said gold mines were
different from the remanded source categories (brick kilns and cement
kilns) because gold mining operations process very large quantities of
ore, and the ore is the only material input that results in mercury
emissions. The commenters stated that, in adopting section 112,
Congress expressly cautioned EPA against setting standards that would
require mining operations to change the ore used as essential
feedstock. The commenters said that, by ignoring the mercury content in
the ore being mined and processed at the facilities in the MACT floor
determination, EPA is requiring facilities to consider the substitution
of, or changes in, the ore that is processed because there is no other
way to achieve the standard. The commenters recommended that EPA
address, as a threshold matter, the differences in processing and
emissions across facilities that result from the variable concentration
of mercury in ore. The commenters recommended that Facility M not be
considered the ``best controlled similar source'' for purposes of
setting the new source MACT floor because the
[[Page 9466]]
facility is not similar to other sources. The commenters stated that,
if EPA does not exclude from the source category facilities that do not
use retorts to process concentrate, then they should subcategorize
them.
Response: After consideration of comments and a re-examination of
the design of the facilities at issue, the emission controls, and other
factors affecting emissions from the carbon processes at Facility M, we
agree that this facility is quite different and unique compared to most
other gold mine ore processing and production facilities, including
other facilities in Nevada, in its carbon process. The difference is
manifested in the processing train in that mercury retorts are not
needed or used at Facility M to recover mercury. As the commenter
notes, the CAA allows EPA to ``distinguish among classes, types and
sizes of sources within a category'' in developing MACT emission
standards, and gold mine facilities without mercury retorts are
different in both class and type from those with mercury retorts.
Accordingly, in the final rule, we identify and set separate MACT
standards for these two different types of carbon processes: those that
use mercury retorts; and those, such as the carbon process at Facility
M, that do not use mercury retorts.
As part of our re-analysis of the MACT floor and the MACT for
sources that are in the carbon processes with mercury retorts group and
sources that are in the carbon processes without mercury retorts group,
we considered new data that were not available at the time of proposal.
Over the past one to two years since our data collection effort for the
proposal, facilities in Nevada have continued to add controls and
improve emission control as part of the NMCP. The new data indicate
there were two facilities with carbon processes without mercury retorts
operating in 2009. Using the data from these two facilities, we
determined that the MACT floor limits for carbon processes without
mercury retorts are 0.17 lb/ton of concentrate for existing sources and
0.14 lb/ton of concentrate for new sources (based on the best
performing facility, Facility M).
In our beyond-the-floor analysis, we considered the addition of a
carbon adsorber on an uncontrolled emission unit within an existing
affected source. We estimate the capital cost as $210,000 with a total
annualized cost of $72,000 per year, an emission reduction of 1.63 lb/
yr of mercury, and a cost effectiveness of $44,000/lb of mercury. We do
not believe that the small emission reduction that this control option
would achieve is justified in light of its cost. We therefore decided
not to go beyond-the-floor. We also considered possible beyond-the-
floor options for new carbon processes without mercury retorts, but
concluded these options were not cost-effective or feasible. Therefore,
for new and existing sources of carbon processes without mercury
retorts, the MACT floor limit is the MACT standard for this affected
source.
As part of our re-analysis for the carbon group processes with
mercury retorts, we collected and evaluated additional data. As
discussed above, several of the facilities have improved emission
control over the levels observed in the database we used at proposal.
Two facilities with newly-installed controls replaced two higher-
emitting facilities that were in the top 5 at proposal, and all three
of the other facilities that remained in the top 5 had lower levels of
emissions after considering the new data. The results are that the MACT
floor limits for carbon processes with mercury retorts are 2.2 lb/ton
of concentrate for existing sources and 0.8 lb/ton of concentrate for
new sources (based on the best performing facility, Facility N). In the
beyond-the-floor analysis, we evaluated the impacts of adding a second
carbon adsorber in series with the controls applied to achieve the MACT
floor level of control. We estimate the capital cost would be $3
million with a total annualized cost of $1.3 million per year, an
emission reduction of 9 lb/yr of mercury, and a cost effectiveness of
$150,000/lb of mercury. Because of the small emission reduction and
high cost effectiveness associated with this additional control, we
decided not to go beyond the floor. Therefore, for existing sources of
carbon processes with mercury retorts, the MACT floor limit is the MACT
standard for this affected source. We also considered possible beyond-
the-floor options for new carbon processes with mercury retorts, but
concluded these options were not cost-effective or feasible.
5. Compliance Alternative for New Carbon Process Sources
Comment: One commenter noted that the compliance ``alternative'' of
97 percent would be unlawful unless EPA specified that carbon sources
had to meet the more stringent of either the floor standard or a 97
percent reduction standard. The commenter stated that because floors
must reflect the emission level achieved by the best performing
sources, allowing sources to meet a 97 percent reduction standard that
was less stringent than the emission level actually achieved by the
relevant best sources would contravene section 112(d)(3) and well-
established D.C. Circuit court precedent.
One commenter supported EPA's use of the percent control
alternative to the new source MACT for the carbon group. The commenter
believes that the percent control alternative for new source carbon
group MACT should also be available as an alternative to the existing
source MACT for the carbon group.
Another commenter stated that another facility, which has an
average mercury reduction efficiency level of 99.995 percent,
represents the ``best controlled'' similar source for the carbon
process group and should be the basis for the alternative limits for
new carbon processes.
Several commenters requested clarification of the way in which
compliance with the alternative for percent reduction would be
demonstrated for new sources when there are multiple control devices on
an emission unit.
Response: We eliminated in the final rule the compliance
alternative of 97 percent reduction for new carbon processes. After
reviewing the comments received on this standard and giving further
consideration to the practicality of how it would be measured, we
concluded that this option would be difficult to implement,
particularly when multiple processes that are operated at different
times vent to a single control device and stack. In addition, we have
limited data supporting this compliance alternative. In proposing this
alternative for comment, we had hoped to, but did not receive
additional data indicating that the 97 percent reduction option would
be equivalent in stringency to the proposed new source limit of 0.14
pounds of mercury per ton of concentrate. Largely due to the reasons
stated above, we have eliminated the 97 percent control efficiency
option for new carbon processes in the final rule. In addition we are
not allowing this percent reduction to be used for existing carbon
sources. We also note that the facility that one commenter identified
as having an average mercury reduction efficiency level of 99.995
percent is now being used as the ``best controlled'' similar source for
the final MACT standard for new carbon processes with mercury retorts.
[[Page 9467]]
D. Compliance Determinations
1. Timing for Compliance Determinations
Comment: Several commenters requested that the compliance deadline
for existing sources be 3 years after the effective date of the rule,
rather than the 2 years proposed. The commenters noted that several
facilities will have to install control devices to achieve the MACT
floor limits that have been proposed. The commenters explained that the
controls must be custom designed for the unique characteristics of each
process and associated process streams at each facility and stated that
it can be time consuming and difficult to design, procure, construct,
and implement emission controls to ensure effective operation for the
particular source.
Response: After reviewing the information provided in public
comments on the challenges of retrofitting new controls, we believe
that allowing 3 years for existing sources to comply is appropriate.
Given the complexity of the sources, the combinations of control
devices that are needed in many cases, and the amount of time necessary
for designing, installing, testing, and commissioning additional
emission controls for mercury, we conclude that 2 years may not provide
adequate time for existing sources to comply with the final emission
standards.
Comment: Several commenters recommended that the rule specify that
source testing results be used to determine compliance for the calendar
year in which the test was conducted rather than to determine
compliance for the prior 12 months. The commenters suggested that the
source test results be applied to the hours of operation at the end of
the calendar year to determine the source's compliance with the MACT
standard on an annual basis, as required in the NMCP. The commenters
suggested that, if more than one source test is conducted in a year,
the facility should average the mercury emission test results to
determine compliance for the calendar year in which the tests were
conducted.
Another commenter commented that the annual compliance testing
should not be constrained to the same calendar quarter each year. The
commenter stated that this can lead to testing during periods of
operation that may not represent normal production capacities. The
commenter believes that mercury emissions testing should be scheduled
for the most appropriate time interval throughout the calendar year.
Response: The permitting authority needs to be able to determine
compliance with the NESHAP as soon as possible after the tests are
completed and test results are available. Consequently, the final rule
requires that initial compliance be determined based on production data
and operating hours for all full calendar months between the date the
rule is published in the Federal Register and the date of the
compliance test, and subsequently, annual compliance must be based on
production data and operating hours for the 12 full calendar months
preceding the compliance test. This allows the permitting authority to
determine if the affected source is in compliance in a timely manner.
(This is consistent with the way compliance determinations are made in
another MACT rule that uses a similar format--National Emission
Standards for Hazardous Air Pollutants for Primary Lead Smelting, 40
CFR part 63, subpart TTT.) If compliance was based on a calendar year,
as suggested by the commenter, then we would not know if a source is in
compliance until after December each year. For example, if a source
conducted its compliance test in March, we would have to wait about 9
more months before we could determine if that source was actually in
compliance. After those 9 months, if the source was not in compliance,
it would mean that the source could have been out of compliance for the
previous 9 months.
Moreover, we do not believe that compliance with the NESHAP based
on the production data from the 12 months prior to the compliance test
would cause problems with reporting under the State program. It is our
understanding that the emissions limits in the Nevada State Phase 2
permits are (or will be) based on concentration in the stacks (e.g.,
micrograms per cubic meter ([mu]g/m\3\)). The limits in this final rule
are based either on pounds of mercury per million tons of ore or pounds
of mercury per tons of concentrate. Therefore, the companies can
continue to report the annual emissions as required under the TRI
program and the State program without conflict with this rule.
If multiple compliance tests are conducted during the year, then a
compliance determination must be made for each separate compliance test
based on the production data and hours of operation for the 12 full
calendar months preceding each test (i.e., the results of multiple
compliance tests conducted throughout the year are not averaged to
provide a single compliance determination for the year).
We understand that the rule, as proposed, may have required all
existing sources to conduct their subsequent annual compliance tests in
the same calendar quarter, and this may pose a scheduling problem
because of the large number of facilities located in the same State
(e.g., Nevada). Our concern was that subsequent annual compliance
tests, if not separated in time, could be conducted for two different
years with little time between the two tests (e.g., only a few days
apart for the extreme case where the first test is conducted in late
December and the second one in early January of the following year). We
are providing scheduling flexibility by requiring that annual
compliance tests be at least 3 months apart and no more than 15 months
apart, and we are providing a similar separation for the period between
the initial compliance test and the first annual compliance test. We do
not believe that tracking multiple compliance dates is a particular
problem for the permitting authority because that is the case for many
other source categories subject to annual compliance testing.
2. Test Methods
Comment: Several commenters supported EPA's proposal of alternate
Methods 30A and 30B for demonstrating compliance. One commenter
supported EPA's requirement to use Method 29 as an emission test
method, but recommended two revisions: Requiring a determination of the
absence of cyclonic flow before sampling, and a minimum sampling time
of 90 minutes for each test run. The commenter also stated that they do
not support the use of the Ontario Hydro Method (ASTM D6784-02), Method
30A, or Method 30B as mercury test methods. The commenter believes that
the methods of demonstrating compliance with the emissions standards
should be consistent with the methods utilized to establish the
emission standards, which were based mainly on Method 29 data. The
commenter said that the typical gas streams associated with the gold
mining industry have high particulate loadings, high mercury
concentrations, sulfur dioxide (SO2), and contain
particulate-bound mercury. The commenter also stated that the
alternative methods were not developed specifically for the gold mining
industry and their typical gas streams and concluded that the results
from the various alternative methods will yield varying results, will
not be comparable, and will provide inconsistent reporting of overall
mercury emissions.
[[Page 9468]]
Response: Method 29 references Method 1, which requires cyclonic
flow checks under certain circumstances. Consequently, in the final
rule, we have removed the specific requirements for cyclonic flow
checks prior to every stack test that were in Sec. 63.11646(a)(1)(vi)
of the proposed rule. Owners or operators should follow the
requirements in the applicable EPA reference method and any additional
requirements specified by the permitting authority.
When specifying the minimum requirements for compliance tests, it
is more important to specify a minimum sampling volume than a minimum
sampling time because the detection of a regulated pollutant is a
function of the volume of the sample rather than the length of time
taken to collect the sample. Thus, the final rule does not specify a
minimum sampling time. We are also changing the required minimum
sampling volume to be 30 dscf rather than the 60 dscf as proposed in
Sec. 63.11646(a)(2) because we believe that 30 dscf generally will be
adequate for detecting mercury emissions for this industry. Affected
facilities should be aware, however, that the minimum sample volume may
sometimes result in a failure to detect any mercury (a non-detect)
emitted from a process unit subject to the emission standard (for the
group of process units within the affected source) because of a mercury
concentration at the outlet lower than expected. If the emission
testing results for any of the emission points yield a non-detect
value, then the minimum detection limit (MDL) must be used in
calculating the emissions for that emission point and, in turn, for
calculating the sum of the mass emissions for all emission points
subject to the emission standard for determining compliance. If the
resulting mercury emissions (in pounds of mercury per ton of
concentrate, or pounds of mercury per million tons of ore) for the
affected source are greater than the MACT emission standard, the owner
or operator may use procedures that produce lower MDL results and
repeat the mercury emissions testing one additional time for any
emission point for which the measured result was below the MDL. If this
additional testing is performed, the results from that testing must be
used to determine compliance (i.e., there are no additional
opportunities allowed to lower the MDL).
After reviewing the information provided by the commenter about
Method 29, we agree with the commenter that Method 29 is the most
appropriate method for compliance determinations for this source
category because of the unique characteristics of these sources.
Therefore, we are promulgating Method 29 as the main method for
compliance in this rule. Alternative methods, such as 30B and the
Ontario Hydro method (OHM; ASTM D6784-02), could be used to demonstrate
compliance for this source category if approved by the permitting
authority. These alternative methods (such as 30B and OHM) may prove to
be more appropriate under certain circumstances. However, we have
omitted Method 30A as an option in the final rule, as it is not yet in
general use.
E. Monitoring
1. Compliance Assurance
Comment: One commenter noted that EPA's proposed mercury standards
are expressed in a format of pounds of mercury per million tons of ore
processed and observed that the proposed rule requires stack testing
only once a year. The commenter claims that EPA's proposed monitoring
requirements would not demonstrate whether sources are in compliance
with their emission standards, which renders the rule unenforceable.
According to the commenter, the once-a-year stack test would provide no
indication as to what a mine's emissions were the rest of the year. The
commenter said that a source that failed its stack test would have only
one violation of emission standards, even if that test showed that the
source likely violated its emission standard throughout the year. The
commenter believes that EPA's proposed monitoring requirements would
not assure compliance with the proposed emission standards. The
commenter also noted that EPA proposed to require sources to monitor
their mercury emissions either with CEMs, sampling, or various types of
parametric monitoring; however, these methods do not provide direct
information about the pounds of mercury emitted. Consequently, none of
these monitoring methods could be used to demonstrate whether a source
is in or out of compliance with the proposed emission standards.
According to another commenter, all three affected source
categories should be required to use CEMS at all times and at all
emission points. The commenter stated that the ore pretreatment group
especially needs CEMS because of variable levels of mercury in the ore
and different operational measures within the control of the facility.
Other commenters supported a requirement for continuous monitoring
and said that the CEMS should be incorporated into the compliance
regime as well. The commenters believe that, if the monitoring results
indicate that the mine is consistently out of compliance for a period
of one week without correction, the process unit should be subject to
compliance-based penalties and/or shut down until corrections are made
and the process unit is back in compliance. According to the
commenters, quarterly stack testing should still be required to
demonstrate that the CEMS is working.
Response: We recognize the importance of requiring adequate
monitoring to assure compliance with the emission standards. Because of
the higher mercury emitting potential of the roaster, we proposed the
option of mercury monitoring using CEMS or weekly monitoring with PS
12B with associated parametric monitoring as well. We are including in
the final rule the option to perform continuous PS 12B monitoring, and,
as with the CEMS, associated parametric monitoring would not be
required. We are changing the frequency of the proposed weekly
concentration monitoring approach for roasters to twice per month (at
least 11 days apart) and would allow a facility to conduct a Method 30B
test (as an alternative to a PS 12B test), supplemented with continuous
parametric monitoring. We changed the frequency because we believe that
sampling twice per month, coupled with continuous parametric
monitoring, is sufficient for determining that the roaster control
devices are operating properly. We added the alternative of using
Method 30B because this method directly measures mercury concentration
and is a valid means of determining whether the concentration is below
the operating limit established during the initial performance test.
The twice per month Method 30B measurements will provide a
concentration value that can be compared to that operating limit to
determine if an exceedance of the operating limit has occurred. Also,
if the twice monthly sampling shows repeated deviations over time, EPA
could decide at a later date that CEMS or continuous monitoring with PS
12B are appropriate and necessary for roasters.
We disagree with the commenter that the proposed monitoring
requirements render the rule unenforceable. Although the mercury
concentrations monitoring for roasters along with the parametric
monitoring of all control devices on all units do not directly measure
pounds of mercury per ton of input, we believe that these actions,
along with the annual emissions compliance tests, is still an
acceptable approach to assure
[[Page 9469]]
compliance with the emission standards all year long. Parametric
monitoring of control devices assures that the control devices are
operating properly (and reducing emissions) on an ongoing basis. Any
exceedance of the parameter limits or operating limits triggers
corrective action. If corrective action does not return the mercury
concentration within the established limits, the plant must conduct a
full compliance test and determine if the source is meeting the mass-
based (lb/million tons of ore) emission standard.
We do not believe that we should include CEMS as a monitoring
option for the non-roaster sources. These sources have less potential
mercury emissions, and requiring CEMS on all these other units would be
quite costly and burdensome. Moreover, most of these other units are,
or will be, controlled with carbon adsorbers, and the carbon adsorber
monitoring required by the final rule is an effective means of ensuring
the controls are working effectively on a continuing basis. We consider
that either frequent testing of carbon beds to monitor for breakthrough
using Method 30B, or frequent adsorbent sampling for mercury content,
is an effective way to ensure these mercury control systems are
operating properly on a continuing basis. The final rule also requires
parametric monitoring of wet scrubbers that are considered the final
mercury control (i.e., not followed by a carbon adsorber or calomel
mercury scrubber). We believe that annual tests coupled with
appropriate parametric monitoring of the wet scrubbers are sufficient
to ensure emissions are properly controlled on a continuing basis.
With regard to the comment that quarterly stack testing should be
required for facilities using a CEMS, we believe that following the
Quality Assurance (QA) procedures detailed in 40 CFR 60, Appendix F,
are sufficient to ensure the CEMS continues to operate as designed, and
in this case, additional stack sampling is not necessary.
2. Operating Limits
Comment: One commenter stated that the operating limits for
roasters and for carbon adsorbers are inappropriate and set up a second
set of MACT standards. The commenter claimed that the operating limits
do not take into account the effects of: Hours of operation of a
process unit on mercury emissions; reduction in performance of a
process unit offset by an improvement in performance of another process
unit; variability in the exhaust gas flow rates with no appreciable
effect on the corresponding mercury emission rate; and variability in
the inlet mercury concentrations to a carbon adsorber. These factors
all result in variability in the outlet mercury concentration. The
commenter also noted that the proposed operating limit for carbon
adsorbers could result in premature carbon change out, resulting in the
generation of more waste. The commenter recommended that EPA defer to
the Nevada state monitoring requirements and only provide for
monitoring of throughput and annual mercury emission testing to
demonstrate compliance with the MACT emission standard. The commenter
believes that any operating limit parameters must be established based
on manufacturer specifications and recommendations in coordination with
the permitting authority and not based on values measured during source
compliance testing.
Response: We proposed the mercury operating limits as a monitoring
tool to ensure that the processes within individual affected sources
and their associated control devices are functioning properly on a
continuing basis and not as a second set of MACT standards. We
developed emission standards for four affected sources, and the
emission standard for an affected source applies to the sum of
emissions from all process units within the affected source. One unit
could have an upward fluctuation in mercury concentration, but the
group of process units could still meet the MACT limit. We see the
value of the operating limit approach as sufficient to detect
significant increases in emissions and as a valuable tool to ensure the
control devices are operating effectively and provide quick
notification of a potential problem with controls or emissions. The
monitoring parameters are used as compliance indicators, and the
relevant mercury operating limits are the main ``triggers'' of a
possible emissions increase and are set to alert facility operators
when emissions are greater than the corresponding mercury operating
limit. We believe it is important to have such monitoring in the rule
to ensure the control devices are working properly.
Regarding specific comments about monitoring the carbon adsorber,
the State of Nevada has had good results with conducting sampling of
the carbon adsorber to maintain its performance. The final rule offers
an additional option of measuring the mercury concentration exiting the
carbon adsorber that also achieves the same objective of avoiding
breakthrough of the bed. We do not expect sudden dramatic failures of
this technology. Instead, we expect to obtain close control of
performance by ensuring that the carbon is changed in a way that
prevents breakthrough. This monitoring methodology should also prevent
premature replacement of the bed.
We disagree with the comments that only monitoring for throughput
and annual emissions testing are sufficient to demonstrate compliance
with the MACT standards. Such an approach does not yield sufficient
data to assure compliance with the emission standards either directly
or indirectly by assuring that the control devices are operating
properly. The parametric monitoring and operating limits specified in
this final rule provide assurance that control devices are properly
operated and maintained between emissions tests, and exceedances of the
operating limit require corrective action. With regard to the comment
that any operating limit parameters should be based solely on
manufacturer specifications and/or in consultation with the permitting
authority, we have provided various options in this rule for
establishing control device parameter limits. Control device operating
parameter values sometimes are site-specific and are associated with a
level of emissions from the source. Therefore, it is generally
preferable for certain control device parameter limits to be associated
with an emissions test that demonstrates compliance with the emissions
standards. However, we agree that certain parameters for mercury
scrubbers applied to roasters, such as the ranges associated with
ensuring the proper chemistry of the scrubber, are best provided by the
system's manufacturer. Guarantees of performance are usually
conditioned by requiring that the system be operated as designed and
specified by the manufacturer, and there is no assurance that a
potentially narrow range that would be established during a short
performance test reflects the full applicable range of proper
operation. We also realize that it may be preferable that the permit
authority establish the parameter limits for some of the control
devices in this industry because of some of the unique characteristics
of the processes and control devices used in this industry and the
experience of the permit authority with addressing these sources.
Therefore, this final rule allows three options for establishing
parameter limits: (1) Based on the initial compliance test; (2)
according to the manufacturer's specifications; or (3) based on limits
established by the permitting authority.
Comment: Some commenters stated that their established parametric
[[Page 9470]]
monitoring programs are sufficient to confirm that mercury emission
controls are functioning properly for roasters. The commenters also
stated that the NMCP permits have required parametric limits and that
additional CEMS for mercury would neither improve the operation of
these current controls, nor reduce mercury emissions. The commenters
concluded that the operating parameters monitored on a regular basis
are key parameters for measuring the efficiency and operation of the
mercury controls and that operating each of these units within the
optimum ranges ensures that mercury emissions are being effectively
controlled.
Response: As discussed above, we do not believe parametric
monitoring alone is sufficient for roasters because of the very high
mercury emission potential, unless the facility has adequately
demonstrated that the mercury emissions from the roasters are
consistently very low (e.g., less than 10 pounds per million tons). We
have concluded that the combined approach of annual stack compliance
testing along with the mercury concentration monitoring and parametric
monitoring requirements and options outlined in this rule are necessary
to detect excess emissions and to ensure controls are working
effectively on a continuous basis. We note that for facilities that
choose to monitor the mercury concentration from the roaster with CEMS
or continuous PS 12B sampling, they do not have to do parametric
monitoring. For facilities that can demonstrate their mercury emissions
are less than 10 lbs per million tons of ore, they only have to do
parametric monitoring, no mercury concentration monitoring.
3. Mercury Concentration Monitoring for Roasters
Comment: One commenter stated that the proposed provisions for
monitoring mercury concentrations in roaster emissions are not based on
roaster process and pollution control device operational parameters and
would not yield reliable information that can be used for detecting and
correcting problems. The commenter also stated that the formula for
establishing the mercury operation limit for roasters is not
appropriate because it uses an emission limit that is based on emission
test data from several process units in addition to the roaster. The
commenter recommended using the methods proposed for parametric
monitoring of roaster emission control devices for all roasters. The
commenter also has concerns about utilizing PS 12A (mercury CEMS) and
PS 12B for emissions monitoring purposes because there are terms and
conditions listed in the proposed rule that are not fully defined. The
commenter also recommended deleting the emissions monitoring
requirements for mercury concentration for carbon adsorbers for the
same reasons described above for roasters.
Response: We disagree with the comment that monitoring the mercury
concentration in roaster emissions would not yield reliable information
that can be used for detecting and correcting problems. An elevated
mercury concentration in the roaster stack gas indicates that there
could be a problem with either the process or the control device, which
could result in excess mercury emissions from that unit. Monitoring the
mercury concentration in roaster emissions provides a direct measure of
the regulated pollutant (mercury). The commenter is correct that the
formula for establishing the mercury operating limit for roasters is
based on emission tests performed on several processes units in
addition to the roaster. However, for the facilities with roasters that
will be subject to the requirements to monitor mercury concentration,
the roaster is the biggest source of potential mercury emissions within
the affected source. Therefore, we conclude that changes in the mercury
concentration in the roaster exhaust gases provide a reasonable
indication of overall emissions from the affected source. In addition,
the operating limit is not used directly to determine compliance with
the MACT emission standard. As mentioned above, it is designed to
detect elevated mercury concentrations in the roaster stack gas, which
could indicate a problem with either the process or the control device.
We continue to believe that it is necessary and appropriate to monitor
mercury concentration for the largest source of potential mercury
emissions in the source category (i.e., the roaster) to detect
excursions in emissions that must be addressed when the operating limit
is exceeded. By developing the mercury operating limit from the
emission standard and compliance test results, an exceedance of the
mercury operating limit will indicate a potential increase in emissions
and that corrective actions are needed.
As described above, we believe that either continuous mercury
sampling or mercury sampling twice per month (coupled with continuous
parametric monitoring of the control device) should be required for the
roaster emissions. If a CEMS is used, the daily average mercury
concentration is calculated by averaging the hourly emissions
concentrations during that day. The final rule includes continuous
sampling with PS 12B as an option for monitoring roasters. If PS 12B is
used for continuous integrated sampling (i.e., without parametric
monitoring), the daily average concentration is determined by assigning
the mercury concentration measured by the sorbent trap monitoring
system (total mass of mercury collected during the sampling period
divided by the sample volume) as the daily average value to each of the
days covered by the integrated sample.
A third option is based on short-term sampling twice per month (at
least 11 days apart) for mercury concentration using either PS 12B or
Method 30B, and if this option is chosen, continuous parametric
monitoring of the mercury scrubber must also be performed. For this
short-term sampling option (twice per month sampling) each measured
mercury concentration must be compared to the operating limit to
determine if an exceedance has occurred. For the contents of the
monitoring plan, see 40 FR 63.8(d)(3) and 40 CFR part 60, Appendix F.
We also disagree that parametric monitoring alone is sufficient for
carbon adsorbers. For carbon adsorbers, measuring the mercury
concentration exiting the carbon bed is also a direct measure of the
pollutant of interest. (The other option as established for years in
NDEP operating permits involves sampling the carbon for mercury
content.) An elevated mercury concentration indicates that there could
be a problem with either the process or the control device, which could
result in excess mercury emissions from that unit. We have established
exit concentration monitoring requirements in many rules for emissions
of organic compounds exiting carbon adsorbers. That monitoring has
proven to be effective to prevent or detect breakthrough, and the same
principles apply here for mercury.
Comment: Commenters stated that CEMS for gold mining operations are
not capable of accurately measuring mercury emissions and that there
are three major challenges with the feasibility of mercury CEMS for the
gold mining industry: Mercury CEMS calibration, sample transport, and
system operability and reliability. The commenters are concerned with
the unavailability of a means to calibrate the CEMS for roasters
because existing calibrator designs are simply not capable of
generating mercury concentrations high enough to provide meaningful
upscale calibration points
[[Page 9471]]
that correspond to gold mining source characteristics. The commenters
noted the unavailability of National Institute of Standards and
Technology (NIST) traceable calibration gases and stated that the
current calibration standards traceable to NIST do not apply to the
full range of mercury concentrations that can be present in the exhaust
gases of roasters. The commenters concluded that the lack of a NIST-
traceable standard is a fatal flaw that precludes using mercury CEMS to
monitor roaster emissions. Regarding sample transport, the commenters
said that current designs of mercury CEMS for coal-fired electric
generating units require high temperature umbilical lines to transport
the sample from the stack to the analyzer and that CEMS on coal-fired
electric generating units have seen umbilical failures occur,
representing another challenge to having CEMS function consistently for
the continuous monitoring of mercury from industrial sources. The
commenters were also concerned with the CEMS operability and
reliability because mercury CEMS must contain some type of converter to
reduce oxidized mercury to elemental mercury and premature catalytic
failures periodically occur in these units resulting in several days of
missing data. The commenters continued by stating that users reported
mercury CEMS to be unavailable as much as 30 to 40 percent of the
electric generating unit operating time. The commenters believe the
amount of downtime to be expected from these systems on roasters would
likely be even higher. The commenter concluded that the breakdown
events, combined with the other types of failures, result in data
availability that is substantially inferior to parametric monitoring
and cannot justify the significant cost and resource investment
necessary to install, operate, and maintain these devices.
The commenters are concerned that continuous data reports of
mercury emissions that are not accurate, reliable, or credible could be
offered as ``credible evidence'' to assert a violation. The commenter
concluded by stating that this concern was particularly troubling in
Nevada, where there are separate mercury limits established pursuant to
State law.
Response: Regarding the feasibility of using CEMS to monitor
mercury emissions from roasters, CEMS have been demonstrated for
process units similar to roasters (e.g., coal-fired power plants), and
we believe there is no technical reason why they will not work for the
roasters. (See NESCAUM, 2010. Technologies for Control and Measurement
of Mercury Emissions from Coal-Fired Power Plants in the United States:
A 2010 Status Report Northeast States for Coordinated Air Use
Management (NESCAUM) July 2010).
Many of the issues with mercury CEMS have been resolved as
facilities have gained experience with their use. However, we realize
that mercury concentrations in the exhaust gases from roasters can be
higher than the range of concentrations for coal-fired power plants,
and that the calibration standards traceable to NIST, that have been
available in the past, have not applied to the full range of mercury
concentrations that can be present in the exhaust gases from roasters.
Nevertheless, as we discussed in the proposal preamble, CEMS
manufacturers supply calibration standards for the ranges of
concentrations seen at roasters.
In addition, the NIST has recently completed certification of a
`NIST Prime' elemental mercury gas generator at concentrations of 41,
68, 85, 105, 140, 185, 230, 287, and 353 [mu]g/m\3\. Mercury gas
generator vendors may now submit elemental mercury gas generators for
certification to serve as `Vendor Primes' in a wide range of
concentrations. Therefore NIST traceable mercury gas standards can now
be made available in concentrations that cover the full range of the
concentrations typically measured from roasters.
After consideration of public comments, we continue to believe CEMS
are a valuable tool and a reasonable option for monitoring mercury
concentrations and comparing those concentrations to the operating
limit that is established by CEMS measurements made during the
compliance test. However, we also point out that the final rule does
not require the use of CEMS; instead, the final rule includes CEMS as
one of the three monitoring options. The other two options that we are
promulgating for monitoring mercury from roasters are: (1) Continuous
monitoring using PS 12B; and (2) twice per month sampling using PS 12B
or Method 30B coupled with parametric monitoring. All three of these
monitoring options are intended to ensure that emissions from the
roasters are not exceeding operating limits, or if they do exceed the
operating limits, that corrective actions are taken in a timely manner
to bring the emissions down to within the operating limits. If these
corrective actions are not successful then the facility must perform a
complete compliance test using the methods in section 63.11646 to
determine whether the affected source is in compliance with the MACT
standard. The CEMs can also be used to help identify problems with
control systems and ensure that corrective actions are taken
immediately to fix such problems. The exceedance of the operating limit
is not intended to determine if the source in violation of the MACT
standard. Rather, it would be the subsequent compliance test pursuant
to section 63.11646 that would be used to determine if the source is in
compliance with the MACT standard.
We understand the commenter's concerns regarding the transport of
samples and converter failures. However, we have revised the final rule
to give facilities 3 years to comply with the rule which will allow
extra time to successfully set-up and operate controls and monitoring
equipment to be able to comply with the MACT standards. We believe this
will provide sufficient time, for facilities that choose the CEMs
monitoring option, to identify and resolve issues with the transport of
samples and converters.
Comment: One commenter stated that the regulated industry has no
experience with direct measurements of mercury concentrations at the
roaster exhaust gas stream. As a result, the commenter believes that
there will be problems in collecting data, establishing appropriate
timeframes for sampling under PS 12B, maintaining instrument
reliability for CEMS, and in establishing confidence in the accuracy of
the results reported by these methods. The commenter claimed that the
calculated operating limit based on source testing and simultaneous
direct measurements may not be reflective of the future daily
operations of all the stack emissions. The commenter noted that flow
rate measurements are critical in verifying compliance with actual
emission limits because sometimes lower flow rates of the stack exhaust
gas flow can artificially elevate the mercury concentration in the gas
stream with no real effect on emissions. The commenter concluded that
any exceedance in mercury concentration should be verified first with a
compliance test before halting the roaster production.
Response: We have learned from the comments received that there may
be a learning curve for facilities to implement the concentration
monitoring procedures. As described in section V.D. of this preamble,
we have established in the final rule a compliance date that is 3 years
after the effective date of the final rule for existing sources, partly
to allow sources time to ensure they can successfully comply with the
monitoring requirements, but mainly to allow time to install new
mercury emission
[[Page 9472]]
controls that we believe will be necessary to meet the emission
standards in the final rule.
We agree that mercury concentration measurements are not direct
measurements of the emissions rate from the affected source and that
flow rate, production, and other factors need to be considered. These
are some of the reasons that the operating limit is not being used as a
direct measure of compliance with the MACT standards. However,
concentration measurements above the operating limit should indicate
that either controls are not working effectively or other problems are
occurring. In either case, exceedances of the operating limit require
investigation and may require corrective actions. The requirement to
shut down the roaster has been removed from this final rule. However an
exceedance of the mercury concentration does trigger corrective action,
and if not corrected requires a compliance test.
Comment: One commenter requested that EPA reduce the weekly Method
12B monitoring frequency to quarterly or at most monthly. The commenter
also requested that EPA include a provision that allows for a source to
demonstrate a correlation or consistency of performance such that the
Method 12B sampling frequency can be further reduced based on the
permitting authority's acceptance of the demonstration. The commenter
suggested that if multiple Method 12B samples are collected in a single
day or over multiple days in the calendar week, then the samples should
be averaged, and this average concentration should be compared to the
operating limit. The commenter said that, for stacks with high mercury
concentration, the sample collection time may be only an hour or two,
and in this case, it may be important to collect more than one sample
in a single day or over multiple days to obtain a representative
mercury concentration measurement.
Response: After taking into consideration the commenter's
rationale, under this monitoring option, the final rule requires the
sampling of mercury concentration at least twice per month (with 2
samples taken at least 11 days apart) instead of weekly sampling as
proposed. If multiple samples are taken during the twice per month
period, each result must be compared to the operating limit separately
(i.e., not averaged). Otherwise, a high result from a sample taken near
the end of the sampling period might not trigger corrective actions to
correct a problem that developed at that time if the results are
averaged with previous samples during periods of good performance. We
do not agree with the suggestion to allow the monitoring frequency to
be reduced if the monitoring results demonstrate consistency over the
long term. We believe that monitoring the mercury concentration at
least twice per month is necessary for roasters to ensure that
potential problems with control systems are identified quickly and
corrective actions are taken in a timely manner.
4. Parametric Monitoring of Control Device for Roasters
Comment: Some commenters recommended that EPA remove the provisions
requiring monitoring of the mercury scrubber liquor flow rate and
scrubber pressure drop because each facility that has a roaster has a
unique sequence of air pollution control devices, and monitoring
parameters that may be appropriate for one roaster may not be
applicable to another. One of the commenters said that the scrubber
liquor flow rate is not currently monitored, nor is it considered a
critical parameter in the daily operation of the scrubber mercury
removal tower associated with roasters at their facility. The commenter
further explained that the scrubber is not a spray tower, but instead
the liquor is recirculated in the tower, so the pump is monitored to
insure it is operational. The commenter stated that the pressure drop
across the mercury removal tower at its roasters is monitored, but is
not considered a critical parameter and that the mercuric ion and
chloride ion concentrations that they monitor are the critical
parameters that define the effectiveness of the mercury scrubber.
Another commenter added that, for the calomel-based mercury
scrubbers, the key parameter is the reagent concentration in the
solution exiting the scrubber and that maintaining the exit reagent
concentration ensures there is sufficient reagent to react with the
mercury vapor. The commenter noted that low exit concentrations
indicate that either the liquor flow rate is too low, or the fresh
reagent addition rate is too low. Thus, liquor flow rate does not need
to be monitored in addition to reagent exit concentration. The
commenter stated that if EPA continues to require them, the ranges
should be based on the manufacturer's specification or an alternative
value approved by the permitting authority, as opposed to the three
test runs from the initial compliance test. One commenter recommended
that the corresponding range or limit for parametric deviations be
applied to a daily average value rather than continuous instantaneous
values or single samples.
Another commenter also stated that the requirement to establish the
minimum water flow rate and pressure drop of the wet scrubber on
readings taken during the performance test should not apply to
scrubbers on roasters. The commenter noted that these parameters were
intended to monitor for physical processes, and the scrubbers on
roasters often include chemical reactions, which are not monitored.
Response: We agree that pressure drop is not relevant to mercury
scrubbers because, unlike venturi scrubbers applied to control PM
emissions, it is not related to its mercury emission control
performance. We have removed pressure drop monitoring from the final
rule for mercury scrubbers. However, we continue to believe that it is
important to monitor the scrubber flow rate to ensure the scrubber
solution is being delivered to the system and that the flow is
adequate, which is related to the system's performance. We understand
that some facilities monitor mercury scrubber solution line pressure
(solution header pressure) as an indicator of flow rate, and we agree
this is adequate to ensure proper flow. Consequently, the final rule
requires hourly monitoring of scrubber flow rate (or line pressure) for
mercury scrubbers on roasters. As with the inlet temperature operating
range, the minimum flow rate or line pressure must be established by
one of the following three ways: (1) During the initial compliance
test, (2) from the manufacturer's specifications, or (3) based on the
limits established by the permitting authority. If the facility chooses
the option to establish the limits during initial compliance, the final
rule requires the scrubber flow rate operating limit to be based on
either the lowest value for any run of the initial compliance test or
10 percent less than the average value measured during the compliance
test and the inlet gas temperature operating limit to be based on
either the highest value for any run of the initial compliance test or
10 percent higher than the average value measured during the compliance
test. The final rule requires hourly monitoring and that corrective
action is triggered if the flow rate or line pressure falls below the
established parameter limit.
Regarding the acceptability of scrubber flow rate and inlet gas
temperature parameter values that were approved by permitting
authorities prior to this final rule, such values must be established
as specified in the final rule
[[Page 9473]]
and are not presumed in advance to be acceptable. Note that the
monitoring requirements for wet scrubbers in Sec. 63.11647 of the
final rule would not apply to the mercury scrubbers on roasters, or any
wet scrubber prior to the mercury scrubber on the roasters.
Comment: One commenter believes that establishing a maximum
operating temperature for inlet gas concentrations by artificially
increasing this temperature during compliance testing may destroy the
control equipment, conflict with recommended operating temperatures,
and artificially increase the reported mercury emissions. The commenter
concluded that these parameters are not deemed critical in the
effective operation of a mercury calomel scrubber. Another commenter
added that their Compliance Assurance Monitoring (CAM) plan provides
for an inlet gas temperature range of 32[deg] to 134 [deg]F to prevent
water freezing problems or extremely hot gas temperatures that could
damage the mercury scrubber. The commenter stated that mercury
scrubbers remove mercury from the gas stream through a chemical
reaction and not a condensation mechanism and that lower temperatures
will not remove (via condensation) additional mercury. The commenter
explained that, although mercury scrubber inlet gas temperature is not
a relevant control performance parameter, their facility maintains the
inlet gas temperature below 134 [deg]F and monitors the temperature
daily to prevent damage to the controls system from excessively low or
high gas temperatures.
Response: After additional review of operating permits and
consideration of public comments, we have found that the inlet
temperature of the mercury scrubber is monitored and maintained within
a range to provide operational flexibility with the lower end bounded
to prevent freezing and the upper end bounded to prevent damage to
equipment, which in turn could lead to excess emissions. In addition,
we have learned that this temperature is dependent on the cooling tower
water temperature used in the process, and this water temperature can
vary quite widely from winter to summer. Facilities may not be able to
address the issues described above if they can only use initial
compliance testing to establish the inlet temperature operating range,
as we proposed. Consequently, the final rule provides the following
three ways for a facility with a roaster to establish an operating
range for inlet temperature: (1) Based on the maximum inlet temperature
during the initial compliance test; (2) from the manufacturer's
specifications; or (3) based on the limits established by the
permitting authority. If the facility chooses the option to establish
the limits during initial compliance, the final rule requires the inlet
gas temperature operating limit to be based on either the highest value
for any run of the initial compliance test or 10 percent higher than
the average value measured during the compliance test. The facility
must monitor the temperature hourly, and any exceedance of the upper
limit for temperature would trigger corrective action.
5. Exceeding the Operating Limits for Roasters
Comment: One commenter was concerned about the consequences of
exceeding a parametric monitoring limit. The commenter remarked that
shutting down the roaster for exceeding a monitoring parameter without
evidence of an ongoing emission limit exceedance is arbitrary and
capricious, unnecessarily punitive, and threatens the economic
viability of the regulated sources. The commenter pointed out that the
ranges of parameters measured during source testing are not necessarily
the only ranges within which the unit can operate effectively. The
parameters proposed by EPA are not the best parameters for monitoring
roaster emissions and do not directly correlate to mercury emissions or
proper control system operation. The commenter also objected to the
period of only 45 minutes to investigate and take corrective action.
One commenter recommended that the corrective action response time
be extended minimally to 48 hours after daily average values are
processed, plus an additional 24 hours to verify the daily average
parametric value was within limits. For facilities that conduct PS 12B
sampling and a daily average parametric deviation persists for 96
hours, the commenter recommended requiring sampling of the roaster's
exhaust using PS 12B within the next 24 hours, then evaluating the
mercury concentration results. If the mercury concentration is below
the operating limit, then, within 10 days of receiving the analytical
results, the facility should be required to either petition the
permitting authority for a change in the parametric limits, or provide
the permitting authority with a compliance plan that details corrective
actions taken to date and the plan and schedule for bringing the
parameter back within range. The commenter said that, if the mercury
concentration is above the operating limit, the facility will be
required to schedule an independent source testing firm to perform a
compliance test within 45 days using one of the approved methods
described in the rule. The commenter noted that the Nevada State agency
requires 30 days to review the testing protocol, and source testing
companies typically require 30 days or more advanced notice.
For roasters where direct concentration measurements are not
required and a daily average parametric deviation persists for 96
hours, the commenter recommended that within 48 hours, the facility
should: (1) Provide the permitting authority with a compliance plan
that details corrective actions taken to date and the plan and schedule
for bringing the parameter back within the limits; or (2) schedule an
independent source testing firm to perform a compliance test within 45
days using one of the approved methods described in the rule. The
commenter concluded that, if the test results show that the source has
exceeded the threshold of 10 lb/million tons of ore, the facility would
be required to implement direct mercury concentration measurements.
One commenter requested that EPA provide an exception from the
shutdown requirement when it can be demonstrated that, notwithstanding
an exceedance of the parametric operating range, the roaster mercury
emissions are less than the operating limit for mercury concentration.
The commenter stated that the mercury concentration measurement is a
more direct indication of the ultimate mercury emissions that the
parametric monitors are designed to address.
Response: We have investigated in greater detail the issues
associated with monitoring roasters, and we have consulted with NDEP
and the owners and operators of roasters to learn more about
appropriate roaster monitoring. We understand that sometimes the ranges
of parameters measured during source testing are not necessarily the
only ranges within which the unit can operate effectively, that is why
in the final rule we are offering two other options for establishing
the ranges: (1) Based on manufacturer's specifications; and (2) ranges
approved by the permitting authority. We believe that monitoring the
scrubber flow rate, inlet gas temperature, and scrubber liquid
chemistry, as required in the final rule, are appropriate parameters to
monitor. We have also revised the requirements of this final rule to
provide assurance that timely corrective actions are taken when a
monitoring parameter is exceeded, and we have included requirements for
testing for
[[Page 9474]]
mercury concentrations to determine if the corrective actions were
successful or if a deviation has occurred. The final rule includes
parametric monitoring of the mercury scrubbers applied to roasters to
control mercury. If a parameter is outside of the established range or
limit, corrective actions are triggered. If corrective actions do not
result in the parameter reading being corrected and verified within 48
hours, a mercury concentration measurement (using CEMs, Method 30B, 29,
OHM, or PS 12B) must be made to determine if the operating limit for
mercury concentration is being exceeded. The measurement must be
performed and the concentration determined within 48 hours (after the
initial 48 hours, or a total of 96 hours). If the measured mercury
concentration meets the operating limit for mercury concentration, the
corrective actions are deemed successful. In addition, the owner or
operator may request approval from the permitting authority to change
the parameter range or limit based on measurements of the parameter at
the time the mercury concentration measurement was made. If, on the
other hand, the operating limit is exceeded, the exceedance must be
reported as a deviation and the facility must conduct a full compliance
test within 40 days to determine if the source is in compliance with
the MACT limit. See Sec. 63.11647(d) of final rule.
Comment: For facilities that monitor roasters with a CEMS, one
commenter proposed that corrective action be required within 48 hours
of receiving and processing the results from the CEMS data, plus an
additional 24 hours should be allowed to collect verification data to
see if the daily average concentration was restored below the operating
limit. The commenter recommended that, if the exceedance persists, the
facility should be required to schedule an independent source testing
firm to perform a compliance test within 45 days.
For facilities that choose PS 12B monitoring, the commenter
recommended that a deviation be considered an exceedance of the
operating limit if the average of three consecutive sampling results
(three weeks) were above the established limit. The commenter proposed
that the facility should then have one week to take corrective actions,
an additional week to take the verification sample using PS 12B, with
receipt of results the following week (three weeks total). The
commenter stated that if the exceedance persists, the facility should
be required to schedule an independent source testing firm to perform a
compliance test within 45 days using one of the approved methods
described in the proposed rule.
Response: After considering these comments on the mercury
concentration operating limit and the above discussion on parametric
monitoring of roasters, we have made several clarifications in the
final rule. If a mercury concentration operating limit is exceeded from
either daily average measurements from a CEMS, continuous sampling
using PS 12B, or from sampling twice per month (at least 11 days apart)
using PS 12B or Method 30B, the exceedance must be reported to the
permit authority as a deviation and corrective actions must be
implemented within 48 hours upon receipt of the sampling results that
show the deviation. Moreover, within 96 hours of the exceedance, the
owner or operator must measure the concentration again (with the CEMS,
PS 12B, Method 30B, Method 29, or OHM) and demonstrate to the permit
authority that the operating limit for mercury concentration has been
met, or inform the permit authority that the limit continues to be
exceeded. If the operating limit is still exceeded after these 96
hours, the owner or operator must conduct a full compliance test for
the ore pretreatment affected source within 40 days to determine if the
affected source is in compliance with the MACT emission standard. If
the source is determined to be in compliance, the compliance test may
also be used to establish a new operating limit for mercury
concentration. See Sec. 63.11647(a)(1)(ii), (a)(2)(ii), and (a)(3)(ii)
of the final rule.
Comment: One commenter requested that EPA provide an exception to
the shutdown requirement for facilities that have well-controlled
roasters and elect to monitor under the proposed Option 3. The
commenter believes a facility should have time (45 days) to demonstrate
that the roaster's mercury emissions remain less than 10 lbs of mercury
per million tons of ore. The commenter stated that this would be
achieved by scheduling an independent source testing firm to perform a
compliance test using methods described in the rule, and calculations
that demonstrate compliance with the limit of 10 lbs per million tons
of ore.
Response: As we have discussed above, the final rule relies in part
on parametric monitoring of mercury scrubbers used on roasters to
assure compliance with the applicable emission standards, and when the
measured parametric values are out of the established operating range,
corrective actions must be taken. This is no different for facilities
that qualify for the exemption described in Sec. 63.11647(a)(5) of the
final rule (i.e., facilities exempt from mercury concentration
monitoring by having demonstrated that their roaster emissions are less
than 10 lb/million tons of ore). For these facilities, the final rule
similarly requires that corrective actions be taken to restore the
scrubber operating parameters to the established operating range. If
the parameters are not restored to the established range within 48
hours of triggering the corrective actions, the owner or operator must
perform mercury concentration sampling of the roaster emissions using
PS 12B, Method 30B, Method 29, CEMS or OHM and determine the mercury
concentration within 48 hours following the initial 48 hours (or a
total of 96 hours from the time the parameter range was exceeded). The
measured concentration must be compared to a mercury concentration
operating limit that is based on Equation 2 in the final rule, where
the value for ``Ctrap'' in Equation 2 is based on the
mercury concentration for the roaster measured during the most recent
compliance test. If the measured mercury concentration meets the
operating limit for mercury concentration, the corrective actions are
deemed successful. In addition, the owner or operator may request
approval from the permitting authority to change the parameter range or
limit based on measurements of the parameter at the time the mercury
concentration measurement was made. If the operating limit is exceeded,
the facility must take corrective actions and report it to the permit
authority as a deviation. The owner or operator must also conduct a
compliance test within 40 days to determine if the roaster operations
are in compliance with the emission standard. See Sec. 63.11647(d) of
the final rule. We also note that the requirement to shut down the
roaster has been removed from this final rule.
6. Carbon Adsorber Temperature Monitoring
Comment: Several commenters stated their concern with the proposed
requirement of monitoring gas stream temperature at the inlet to the
carbon adsorber and maintaining the inlet temperature below the maximum
temperature established during the compliance test. They noted that the
primary purpose for monitoring the inlet gas stream temperature of
carbon adsorbers is to prevent spontaneous combustion of the sulfidized
carbon in the adsorber, not to detect excursions in mercury emissions.
The commenters also stated that some carbon adsorption systems heat the
gas stream prior to the
[[Page 9475]]
carbon adsorber to prevent moisture buildup and/or subsequent
condensation in the carbon. The commenters explained that the NMCP
already requires that the exit gas temperature of condensers prior to
the carbon adsorbers be established to minimize mercury emissions from
the condenser. The commenters believe that an increase in inlet gas
temperature to a carbon adsorption unit is not indicative of an
increase in inlet gas stream mercury emissions because the high
operating temperatures of the processes volatilize approximately 100
percent of mercury. The commenters stated that establishing a maximum
operating temperature for inlet gas concentrations by artificially
increasing this temperature during compliance testing may destroy
mercury control equipment; conflict with NMCP requirements and/or
manufacturer's recommended operating temperatures; artificially
increase the reported mercury emissions; or artificially decrease the
allowable operating limit for mercury concentration.
The commenters continued by stating that, if EPA persisted in
requiring the monitoring of the gas stream inlet temperature, the
maximum inlet temperature limit should be established by either the
manufacturer's recommendation and/or concurrence with the permitting
authority. The commenters proposed monitoring the inlet temperature
once per shift as an option to continuously monitoring the inlet
temperature and comparing the daily averages rather than the hourly
averages to the operating limit. The commenters noted that many
facilities do not have digital acquisition systems capable of recording
continuous data, and monitoring once per shift is sufficient to
maintain control performance. The commenters suggested that, if
corrective action is needed, the facility should be allowed to sample
the carbon loading to demonstrate that the effectiveness of the carbon
adsorber has not been adversely impacted.
Response: The purpose of monitoring the inlet temperature to carbon
adsorbers is not to provide an indication of higher mercury
concentrations in the inlet stream as suggested by the commenters. The
purpose is related to the fact that temperature is a fundamental
parameter that affects the efficiency and capacity of carbon adsorbers.
Generally, higher temperatures result in lower capacity and earlier
breakthrough and, in fact, high temperatures are used to desorb
adsorbed pollutants to regenerate carbon. In the extreme of
temperature, the carbon adsorber might actually be desorbing rather
than acting as a control device. This is particularly important for
those carbon adsorbers applied to high temperature thermal processes,
such as carbon kilns and melt furnaces, where it is possible for the
exhaust temperature to rise above the normal operating temperature or
above the temperature at which the carbon adsorber was designed to
operate. For high temperature processes (such as furnaces), and not
those such as electrowinning where the temperature may be near ambient
conditions, we continue to require monitoring the inlet temperature.
Owners or operators must establish an operating limit for temperature
based on one of the following: (1) The maximum temperature during the
initial compliance test; (2) from the manufacturer's specifications; or
(3) based on limits established by the permitting authority. If this
established operating limit is exceeded corrective action must be taken
and the exceedance reported as a deviation to the permit authority.
Further, the final rule requires facilities to monitor inlet
temperature once per shift rather than continuously, as was proposed.
Because inlet temperatures should not vary greatly over the course of
an 8- to 12-hour period, we believe monitoring once per shift is
adequate. We also conclude that if a temperature exceedance has
occurred, the carbon bed should be sampled or the outlet concentration
determined, depending on the monitoring option chosen, within 48 hours
to ensure no permanent damage to the carbon adsorber occurred as a
result of the deviation. We believe the temperature exceedance should
be reported as a deviation even if the subsequent monitoring shows that
the carbon bed is operating properly because the subsequent monitoring
would not necessarily detect if mercury had been desorbed and excess
emissions occurred.
7. Monitoring of Wet Scrubbers
Comment: One commenter proposed that only the scrubber water flow
rate monitoring be required for wet scrubbers on the quenching circuits
associated with the roaster. The commenter wanted to confirm that wet
scrubber monitoring does not apply to wet scrubbers or condensers on
roasters. Another commenter asked that EPA confirm that the term ``wet
scrubbers'' does not include condensers, which are used throughout the
mining processes for gas cooling to condense water or (in the case of
retorts) mercury. Another commenter asked EPA to confirm that wet
scrubber monitoring does not apply to wet scrubbers associated with ore
preheaters.
One commenter noted that continuous readings on wet scrubbers are
unreliable and proposed monitoring the water flow rate and pressure
drop once per shift. The commenter noted that if any water flow rate or
pressure drop reading exceeds the operating limit, the facility should
follow the procedures for operating limit exceedances. The commenter
stated that many facilities do not have data acquisition systems
capable of recording continuous data and that wet scrubbers are
primarily used to control particulates. The commenter concluded by
stating that wet scrubbers are not key mercury controls and monitoring
once per shift is sufficient to maintain control performance on a
continuing basis.
One commenter wanted to confirm that the limits established during
testing would not be more stringent than the requirements set forth in
the Standards of Performance for New Stationary Sources for Metallic
Mineral Processing Plants, which allows for plus or minus 30 percent.
Another commenter recommended that the operating limit for wet scrubber
monitoring be based on either the lowest average value during any test
run or no lower than 10 percent below the average value measured during
the test.
Response: We are clarifying in the final rule that Sec.
63.11647(h) applies only to wet scrubbers not followed by a mercury
control system (i.e., carbon adsorber, calomel mercury scrubber, etc.).
It is necessary to monitor the primary mercury emission control device,
which is the last stage of the exhaust gas cleaning treatment train, to
ensure it is operating properly and controlling mercury emissions, and
the rule does not require that wet scrubbers in the gas treatment train
(typically used for control of PM and/or SO2) prior to the
primary mercury emission control device be monitored under this rule
for mercury emissions. However, if there is no carbon adsorber or
mercury scrubber, and the wet scrubber in question is the only control
device for mercury emissions, the final rule requires that it be
monitored once per shift per operating day (e.g., minimum of two times
per day) for pressure drop and flow rate with operating limits that are
either established during the initial compliance test, from the
manufacturer's specifications, or based on approval from the permitting
authority (except for pressure drop for autoclaves as discussed above).
This applies to wet scrubbers on ore preheaters and quenching if there
is no
[[Page 9476]]
carbon adsorber or mercury scrubber in the exhaust gas treatment train.
As discussed above, the scrubber monitoring for roasters applies to the
mercury scrubber (located at or near the end of the exhaust gas
treatment train) and does not apply to the wet scrubbers that are used
to remove PM and SO2 prior to the mercury scrubber.
We are clarifying in the final rule that condensers, such as those
found at roasters and mercury retorts, are not wet scrubbers. We agree
that monitoring and recording the pressure drop once per shift is
adequate for monitoring these wet scrubbers to ensure they are
operating properly. We disagree that a buffer of 30
percent based on a certain New Source Performance Standard (NSPS)
subpart is appropriate for this NESHAP for mercury. The comment
suggesting an option of a 10 percent buffer around the
average value during the performance test has merit as an option to
only using the lowest value during any individual run as the operating
limit. If the system is so stable that it shows very minimal
variability during the performance test, we agree that it is
appropriate to add 10 percent to account for potential
future variability. Consequently, we are incorporating this option in
the final rule, as suggested by the commenter. However, we are using
10 percent rather than 30 percent. We are
also clarifying for the final rule for wet scrubbers on an autoclave,
that facilities must establish the pressure drop range according to
manufacturer's specifications.
8. Monitoring of Multiple Units Ducted to One Stack
Comment: Commenters requested clarification that, for facilities
that have two roasters ducted together through a shared mercury control
system, the mercury concentration monitoring would be conducted on the
combined exhaust stream. The commenters also requested clarification
that the mercury concentration operating limit for two roasters that
share a control system would be established during the simultaneous
operation of the roasters in order to account for the combined mercury
emissions from both roasters.
Commenters also requested clarification that, for facilities with
multiple process units ducted together through a shared carbon
adsorber, the mercury concentration monitoring would be conducted on
the combined exhaust stream. The commenters also requested
clarification that the mercury concentration operating limit for a
carbon adsorber for multiple units that share the carbon adsorber would
be established during the simultaneous operations of all process units
in order to account for the combined mercury emissions.
Response: We agree with the commenters in general and have made the
following clarifications in the final rule. If two roasters share a
common control device and stack, the mercury concentration operating
limit can be based on both roasters operating if possible. However,
monitoring for mercury concentration must be performed at the frequency
specified in the final rule whether only one or both roasters are
operating. We also have clarified that, for multiple process units
vented to a common carbon adsorber, the mercury concentration operating
limit can be based on all units operating if possible. However, the
ongoing mercury concentration monitoring must be performed at the
frequency specified in the final rule for whatever units are operating
at the time.
9. Monitoring Mercury Concentration in Roaster Ore
Comment: One commenter objected to the proposed requirement to
conduct additional compliance testing if the mercury concentration in
the ore fed to the roaster is higher than any concentration measured in
the previous 12 months. The commenter stated that there would not be an
increase in the mercury emissions from their roasters because of the
extensive series of mercury controls, some of which operate more
efficiently at higher mercury loadings with unchanged stack emissions.
In addition, the commenter noted that the rule does not provide details
on how to measure the mercury ore concentration or what threshold of
significance would be used to show an increase in ore mercury content
occurred. The commenter concluded that the requirement would only
provide extra cost and burden without any environmental benefit.
Response: We agree with the commenter and have removed this
requirement (Sec. 63.11647(a)(4)(iii) of proposed rule) from the final
rule. We have no data showing that the mercury content of the ore has a
significant effect on the performance of mercury scrubbers applied to
roasters, which are designed to handle and operate efficiently for a
range of mercury inlet concentrations. In addition, roasters condense
and recover elemental mercury prior to the mercury scrubber, and any
increase in mercury loading would likely result in an increase in the
recovery of liquid elemental mercury. We have identified and require
the monitoring of parameters associated with the scrubber chemistry,
and maintaining these parameters within the established range for which
the mercury scrubber was designed. This monitoring approach helps
ensure that the mercury scrubbers are controlling mercury emission
independent of variations in ore mercury content.
VI. Summary of Environmental, Economic and Health Benefits
For proposal, we estimated baseline mercury emissions to be 3,119
lb/yr based on the available emissions data and average process data
for the period 2007 to 2009. To estimate the impacts of the final rule,
we have revised our baseline mercury emissions estimate to account for
the recent installation of new mercury emission controls at two
facilities and additional test data received since proposal. As a
result of these changes, we now estimate baseline mercury emissions to
be 2,636 lb/yr. We estimate the final MACT standard will reduce mercury
emissions from gold mine ore processing and production by 1,461 lb/yr
from the baseline emissions levels of 2,636 lb/yr down to a level of
1,176 lb/yr once this NESHAP is fully implemented. The annual emissions
expected after the MACT standards are implemented (1,176 lb/yr)
represent an estimated 77 percent reduction from 2007 emissions (5,000
lb/yr), a 95 percent reduction from the emissions level in 2001 (about
23,000 lb/yr), and more than 97 percent reduction from uncontrolled
emissions levels (more than 37,000 lb/yr). The capital cost of emission
controls is estimated as $36 million with a total annualized cost of $8
million per year. The capital costs for monitoring, reporting, and
recordkeeping are estimated as $0.5 to $1.0 million with a total
annualized cost of $0.7 to $1.5 million per year, depending on the
monitoring option that is chosen. The overall cost effectiveness is
estimated to be about $6,300 per pound of mercury reduced. The cost of
compliance is estimated to be less than 0.8 percent of sales for all
affected firms. We therefore believe that the economic impact on an
affected company would be insignificant. Electricity consumption is
expected to increase by about 12,600 megawatt-hours per year due to
increased fan capacity for carbon adsorbers and the installation of
refrigeration units or condensers on a few process units. Non-hazardous
solid waste (spent carbon containing mercury that must be regenerated
or disposed of) would increase by about 7 tons per year.
[[Page 9477]]
VII. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review
This action is a ``significant regulatory action'' under the terms
of Executive Order 12866 (58 FR 51735, October 4, 1993) because it may
raise novel legal or policy issues. Accordingly, EPA submitted this
action to the Office of Management and Budget (OMB) for review under
Executive Order 12866, and any changes made in response to OMB
recommendations have been documented in the docket for this action.
B. Paperwork Reduction Act
The information collection requirements in this final rule have
been submitted for approval to OMB under the Paperwork Reduction Act,
44 U.S.C. 3501 et seq. The Information Collection Request (ICR)
document prepared by EPA has been assigned EPA ICR No. 2383.01.
The recordkeeping and reporting requirements in this final rule are
based, in large part, on the information collection requirements in
EPA's NESHAP General Provisions (40 CFR part 63, subpart A). The
recordkeeping and reporting requirements in the General Provisions are
specifically authorized by section 114 of the CAA (42 U.S.C. 7414). All
information other than emissions data submitted to EPA pursuant to the
information collection requirements for which a claim of
confidentiality is made is safeguarded according to CAA section 114(c)
and EPA's implementing regulations at 40 CFR part 2, subpart B.
This final NESHAP will require applicable one-time notifications
according to the NESHAP General Provisions. In addition, owners or
operators must submit annual notifications of compliance status and
report any deviations in each semiannual reporting period. Records of
all performance tests, measurements of feed input rates, monitoring
data, and corrective actions will be required.
The average annual burden for this information collection averaged
over the first 3 years of this ICR is estimated to total 483 labor
hours per year at a cost of approximately $26,847 per year for the 21
facilities that will be subject to this final rule, or approximately 23
hours per year per facility. Capital costs are estimated as $1.0
million, operation and maintenance costs are estimated as $52,000 per
year, and total annualized cost (including capital recovery) is
estimated as $360,210 per year for this final rule's information
collection requirements. No costs or burden hours are estimated for new
sources because none is projected for the next 3 years. Burden is
defined at 5 CFR 1320.3(b).
An agency may not conduct or sponsor, and a person is not required
to respond to, a collection of information unless the collection
displays a currently valid OMB control number. The OMB control numbers
for EPA's regulations in 40 CFR part 63 are listed in 40 CFR part 9. In
addition, EPA is amending the table in 40 CFR part 9 of currently
approved OMB control numbers for various regulations to list the
regulatory citations for the information requirements contained in this
final rule.
C. Regulatory Flexibility Act
The Regulatory Flexibility Act generally requires an agency to
prepare a regulatory flexibility analysis of any rule subject to notice
and comment rulemaking requirements under the Administrative Procedure
Act or any other statute unless the agency certifies that this rule
would not have a significant economic impact on a substantial number of
small entities. Small entities include small businesses, small not-for-
profit enterprises, and small governmental jurisdictions.
For the purposes of assessing the impacts of this final NESHAP on
small entities, a small entity is defined as: (1) A small business
whose parent company meets the Small Business Administration size
standards for small businesses found at 13 CFR 121.201 (less than 500
employees for gold mine ore processing and production facilities--NAICS
212221); (2) a small governmental jurisdiction that is a government of
a city, county, town, school district, or special district with a
population of less than 50,000; and (3) a small organization that is
any not-for-profit enterprise that is independently owned and operated
and is not dominant in its field.
After considering the economic impacts of this final rule on small
entities, I certify that this action will not have a significant
economic impact on a substantial number of small entities. This final
rule is estimated to impact about 21 gold mine ore processing and
production facilities, none of which are owned by small entities. Thus,
there are no impacts to small entities from this final rule. Although
this final rule will contain requirements for new sources, EPA expects
few, if any, new sources to be constructed in the next several years.
Therefore, EPA did not estimate the impacts for new affected sources
for this final rule.
Although this final rule will not have a significant economic
impact on a substantial number of small entities, EPA nonetheless has
tried to reduce the impact of this final rule on small and large
entities. These standards establish emission limits that reflect
practices and controls that are used throughout the industry and in
many cases are already required by State operating permits. These
standards also require only the essential monitoring, recordkeeping,
and reporting needed to verify compliance. These final standards were
developed based on information obtained from industry representatives
in our surveys, consultation with business representatives and their
trade association and other stakeholders.
D. Unfunded Mandates Reform Act
This final rule does not contain a Federal mandate that may result
in expenditures of $100 million or more for State, local, and tribal
governments, in the aggregate, or to the private sector in any one
year. This final rule is not expected to impact State, local, or tribal
governments. The total nationwide annualized cost of this final rule
for affected industrial sources is $9.1 million/yr. Thus, this final
rule is not subject to the requirements of sections 202 and 205 of the
Unfunded Mandates Reform Act (UMRA).
This final rule is also not subject to the requirements of section
203 of UMRA because it contains no regulatory requirements that might
significantly or uniquely affect small governments. This final rule
will not apply to such governments and will not impose any obligations
upon them.
E. Executive Order 13132: Federalism
This action does not have federalism implications. It will not have
substantial direct effects on the States, on the relationship between
the national government and the States, or on the distribution of power
and responsibilities among the various levels of government, as
specified in Executive Order 13132. This final rule does not impose any
requirements on state and local governments. Thus, Executive Order
13132 does not apply to this action.
In the spirit of Executive Order 13132, and consistent with EPA
policy to promote communications between EPA and State and local
governments, EPA specifically solicited comment on this proposed action
from State and local officials.
[[Page 9478]]
F. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments
This action does not have tribal implications, as specified in
Executive Order 13175 (65 FR 67249, November 9, 2000). This final rule
imposes no requirements on tribal governments; thus, Executive Order
13175 does not apply to this action. Although EPA requested comment
from tribal officials in developing this action, no comments on the
proposal were received from tribal governments. However, the reductions
in mercury emissions to the environment, which will be achieved by this
final rule, will certainly benefit tribal populations within the
vicinity of affected gold mine ore processing and production
facilities.
G. Executive Order 13045: Protection of Children From Environmental
Health and Safety Risks
EPA interprets Executive Order 13045 (62 FR 19885, April 22, 1997)
as applying only to those regulatory actions that are based on health
or safety risks, such that the analysis required under section 5-501 of
the Executive Order has the potential to influence the regulation. This
action is not subject to Executive Order 13045 because it is based
solely on technology performance. However, we note that the final rule
will result in significant reductions in emissions of mercury, and thus
will provide benefits to children's health.
H. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
This action is not a ``significant energy action'' as defined in
Executive Order 13211 (66 FR 28355, May 22, 2001) because it is not
likely to have a significant adverse effect on the supply,
distribution, or use of energy. We have concluded that this final rule
will not likely have any significant adverse energy effects because
energy consumption would increase by only 12,600 megawatt-hours per
year.
I. National Technology Transfer and Advancement Act
Section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (``NTTAA''), Public Law 104-113 (15 U.S.C. 272 note),
directs EPA to use voluntary consensus standards (VCS) in its
regulatory activities unless to do so would be inconsistent with
applicable law or otherwise impractical. VCS are technical standards
(e.g., materials specifications, test methods, sampling procedures,
business practices) that are developed or adopted by voluntary
consensus standards bodies. NTTAA directs EPA to provide Congress,
through OMB, explanations when the Agency decides not to use available
and applicable VCS.
This final rulemaking involves technical standards. EPA decided to
use ASME PTC 19.10-1981, ``Flue and Exhaust Gas Analyses,'' for its
manual methods of measuring the oxygen or carbon dioxide content of the
exhaust gas. These parts of ASME PTC 19.10-1981 are acceptable
alternatives to EPA Method 3B. This standard is available from the
American Society of Mechanical Engineers (ASME), Three Park Avenue, New
York, NY 10016-5990.
Another VCS, ASTM D6784-02, ``Standard Test Method for Elemental,
Oxidized, Particle-Bound and Total Mercury in Flue Gas Generated from
Coal-Fired Stationary Sources (Ontario Hydro Method)'' is an acceptable
alternative to EPA Method 29 for this NESHAP if approved by the permit
authority. This performance test method is available from ASTM
International. See http://www.astm.org/.
EPA has also decided to use EPA Methods 1, 1A, 2, 2A, 2C, 2D, 2F,
2G, 3, 3A, 3B, 4, 12A, 12B, 29, 30B, SW-846 Method 7471B, ``Mercury in
Solid or Semisolid Waste (Manual Cold-Vapor Technique),'' (incorporated
by reference--see Sec. 63.14) and ASTM D6784-02, ``Standard Test
Method for Elemental, Oxidized, Particle-Bound and Total Mercury in
Flue Gas Generated from Coal-Fired Stationary Sources,'' (incorporated
by reference--see Sec. 63.14). Although the Agency has identified 14
VCS as being potentially applicable to these methods cited in this
rule, we have decided not to use these standards in this final
rulemaking. The use of these VCS would have been impractical because
they do not meet the objectives of the standards cited in this rule.
The search and review results are in the docket for this final rule.
Under section 63.7(f) and section 63.8(f) of Subpart A of the
General Provisions, a source may apply to EPA for permission to use
alternative test methods or alternative monitoring requirements in
place of any required testing methods, performance specifications, or
procedures in the final rule.
J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations
Executive Order 12898 (59 FR 7629, February 16, 1994) establishes
Federal executive policy on environmental justice. Its main provision
directs Federal agencies, to the greatest extent practicable and
permitted by law, to make environmental justice part of their mission
by identifying and addressing, as appropriate, disproportionately high
and adverse human health or environmental effects of their programs,
policies, and activities on minority populations and low-income
populations in the United States.
EPA has determined that this final rule will not have
disproportionately high and adverse human health or environmental
effects on minority or low-income populations because it will increase
the level of environmental protection for all affected populations
without having any disproportionately high and adverse human health or
environmental effects on any population, including any minority or low-
income population.
Additionally, the Agency has reviewed this rule to determine if
there were any existing disproportionately high and adverse human
health or environmental effects on minority or low-income populations
that could be mitigated by this rulemaking. An analysis of demographic
data showed that the areas in closest proximity to gold mines are very
rural, with low total populations. The population total for block
groups which centers are within 3 miles of a gold mine facility is
1,580. At the three mile radius, minority populations and children's
populations are underrepresented when compared to national averages,
while populations living below poverty are overrepresented. The
aggregate average percentages for these groups are 26.3 percent, 30.5
percent, and 26 percent for minority populations, populations living
below poverty, and children's populations, respectively. These averages
are compared to national averages across block groups for these
populations which are 31.8 percent, 12.5 percent, and 25.7 percent.
There were only two block groups with centers within 3 miles of any
gold mine, and the total population living below poverty was found to
be 492.
In determining the aggregate demographic makeup of the communities
near affected sources, EPA used census data at the block group level to
identify demographics of the populations considered to be living near
affected sources, such that they have notable exposures to current
emissions from these sources. In this approach, EPA reviewed the
distributions of different socio-demographic groups in the locations of
the expected emission reductions from this rule. The review
[[Page 9479]]
identified those census block groups within a circular distance of a 1,
3, and 5 miles of affected sources and determined the demographic and
socio-economic composition (e.g., race, income, education, etc.) of
these census block groups. The radius of 3 miles (or approximately 5
kilometers) has been used in other demographic analyses focused on
areas around potential sources.5 6 7 8 Gold mine facilities
were assumed to have an average area of 7 square miles and buffered
distances were calculated beyond the 7 square mile area to count
populations not within the mine boundaries. EPA's demographic analysis
has shown that these areas have an overrepresentation of populations
below poverty, and an underrepresentation of minority and children's
populations.\9\
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\5\ U.S. GAO (Government Accountability Office). Demographics of
People Living Near Waste Facilities. Washington, DC: Government
Printing Office; 1995.
\6\ Mohai P, Saha R. ``Reassessing Racial and Socio-economic
Disparities in Environmental Justice Research''. Demography.
2006;43(2):383-399.
\7\ Mennis J. ``Using Geographic Information Systems to Create
and Analyze Statistical Surfaces of Populations and Risk for
Environmental Justice Analysis''. Social Science Quarterly,
2002;83(1):281-297.
\8\ Bullard RD, Mohai P, Wright B, Saha R, et al. Toxic Waste
and Race at Twenty 1987-2007. United Church of Christ. March 2007.
\9\ The results of the demographic analysis are presented in
``Review of Environmental Justice Impacts for Gold Mines'', December
2010, a copy of which is available in the docket.
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This action establishes national emission standards for new and
existing gold mines. The EPA estimates that there are approximately 23
such locations covered by this rule. The rule will reduce emissions of
mercury (Hg), and as a result have positive health and welfare benefits
to sustenance fishing communities, many of which are often considered
to have environmental justice concerns.
EPA defines ``Environmental Justice'' to include meaningful
involvement of all people regardless of race, color, national origin,
or income with respect to the development, implementation, and
enforcement of environmental laws, regulations, and policies. To
promote meaningful involvement, EPA has developed a communication and
outreach strategy to ensure that interested communities have access to
this rule and are aware of its content. EPA will publicize the
rulemaking via EJ newsletters, Tribal newsletters, EJ listservs, and
the Internet, including EPA's Office of Policy's Rulemaking Gateway Web
site (http://yosemite.epa.gov/opei/RuleGate.nsf/). EPA will also
conduct targeted outreach to EJ communities as appropriate. Outreach
activities may include providing general rulemaking fact sheets (e.g.,
why is this important for my community) for EJ community groups and
conducting conference calls with interested communities. In addition,
State and Federal permitting requirements will provide State and local
governments and members of affected communities the opportunity to
provide comments on the permit conditions associated with permitting
the sources affected by this rulemaking.
Overall, this final rule is expected to reduce mercury emissions
from gold mine ore processing and production facilities and thus
decrease the amount of such emissions to which all affected populations
are exposed.
K. Congressional Review Act
The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. EPA will submit a report containing this final rule and
other required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of this final rule in the Federal Register. A major rule
cannot take effect until 60 days after it is published in the Federal
Register. This action is not a ``major rule'' as defined by 5 U.S.C.
804(2). This final rule will be effective on February 17, 2011.
List of Subjects
40 CFR Part 9
Environmental protection, Reporting and recordkeeping requirements.
40 CFR Part 63
Environmental protection, Air pollution control, Hazardous
substances, Incorporation by reference, Reporting and recordkeeping
requirements.
Dated: December 16, 2010.
Lisa P. Jackson,
Administrator.
For the reasons stated in the preamble, title 40, chapter I, of the
Code of Federal Regulations is amended as follows:
PART 9--[AMENDED]
0
1. The authority citation for part 9 continues to read as follows:
Authority: 7 U.S.C. 135, et seq., 136-136y; 15 U.S.C. 2001,
2003, 2005, 2006, 2601-2671; 21 U.S.C. 331j, 346a, 348; 31 U.S.C.
9701; 33 U.S.C. 1251, et seq., 1311, 1313d, 1314, 1318, 1321, 1326,
1330, 1342, 1344, 1345(d) and (e), 1361; E.O. 11735, 38 FR 21243, 3
CFR, 1971-1975 Comp. p. 973; 42 U.S.C. 241, 242b, 243, 246, 300f,
300g, 300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-1, 300j-
2, 300j-3, 300j-4, 300j-9, 1857, et seq., 6901-6992k, 7401-7671q,
7542, 9601-9657, 11023, 11048.
Subpart A--[Amended]
* * * * *
0
2. The table in Sec. 9.1 is amended by adding an entry in numerical
order for ``63.11647-63.11648'' under the heading ``National Emission
Standards for Hazardous Air Pollutants for Source Categories'' to read
as follows:
Sec. 9.1 OMB Approvals under the Paperwork Reduction Act.
* * * * *
------------------------------------------------------------------------
OMB control
40 CFR citation No.
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* * * * *
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National Emission Standards for Hazardous Air Pollutants for Source
Categories \3\
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* * * * *
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63.11647-63.11648.......................................... 2060-NEW
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* * * * *
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* * * * *
\3\ The ICRs referenced in this section of the table encompass the
applicable general provisions contained in 40 CFR part 63, subpart A,
which are not independent information collection requirements.
* * * * *
PART 63--[AMENDED]
0
3. The authority citation for part 63 continues to read as follows:
Authority: 42 U.S.C. 7401 et seq.
Subpart A--[Amended]
0
4. Section 63.14 is amended by adding paragraph (b)(66), revising
paragraph (i)(1), and adding paragraph (k)(1)(v) to read as follows:
Sec. 63.14 Incorporation by reference.
* * * * *
(b) * * *
(66) ASTM D6784-02 (Reapproved 2008), Standard Test Method for
Elemental, Oxidized, Particle-Bound and Total Mercury in Flue Gas
Generated from Coal-Fired Stationary Sources (Ontario Hydro Method),
[[Page 9480]]
approved April 1, 2008, IBR approved for Sec. 63.11646(a)(1)(vi),
Sec. 63.11647(a)(1)(ii), Sec. 63.11647(a)(3)(ii), and Sec.
63.11647(d).
* * * * *
(i) * * *
(1) ANSI/ASME PTC 19.10-1981, Flue and Exhaust Gas Analyses [Part
10, Instruments and Apparatus], issued August 31, 1981 IBR approved for
Sec. Sec. 63.309(k)(1)(iii), 63.865(b), 63.3166(a)(3),
63.3360(e)(1)(iii), 63.3545(a)(3), 63.3555(a)(3), 63.4166(a)(3),
63.4362(a)(3), 63.4766(a)(3), 63.4965(a)(3), 63.5160(d)(1)(iii),
63.9307(c)(2), 63.9323(a)(3), 63.11148(e)(3)(iii), 63.11155(e)(3),
63.11162(f)(3)(iii) and (f)(4), 63.11163(g)(1)(iii) and (g)(2),
63.11410(j)(1)(iii), 63.11551(a)(2)(i)(C), 63.11646(a)(1)(iii), table 5
to subpart DDDDD of this part, and table 1 to subpart ZZZZZ of this
part.
* * * * *
(k) * * *
(1) * * *
(v) SW-846 Method 74741B, Revision 2, ``Mercury in Solid or
Semisolid Waste (Manual Cold-Vapor Technique)'' February 2007, IBR
approved for Sec. 63.11647(f)(2).
* * * * *
0
5. Part 63 is amended by adding subpart EEEEEEE to read as follows:
Subpart EEEEEEE--National Emission Standards for Hazardous Air
Pollutants: Gold Mine Ore Processing and Production Area Source
Category
Applicability and Compliance Dates
Sec.
63.11640 Am I subject to this subpart?
63.11641 What are my compliance dates?
Standards and Compliance Requirements
63.11645 What are my mercury emission standards?
63.11646 What are my compliance requirements?
63.11647 What are my monitoring requirements?
63.11648 What are my notification, reporting, and recordkeeping
requirements?
Other Requirements and Information
63.11650 What General Provisions apply to this subpart?
63.11651 What definitions apply to this subpart?
63.11652 Who implements and enforces this subpart?
63.11653 [Reserved]
Tables to Subpart EEEEEEE of Part 63
Table 1 to Subpart EEEEEEE of Part 63--Applicability of General
Provisions to Subpart EEEEEEE
Subpart EEEEEEE--National Emission Standards for Hazardous Air
Pollutants: Gold Mine Ore Processing and Production Area Source
Category
Applicability and Compliance Dates
Sec. 63.11640 Am I subject to this subpart?
(a) You are subject to this subpart if you own or operate a gold
mine ore processing and production facility as defined in Sec.
63.11651, that is an area source.
(b) This subpart applies to each new or existing affected source.
The affected sources are each collection of ``ore pretreatment
processes'' at a gold mine ore processing and production facility, each
collection of ``carbon processes with mercury retorts'' at a gold mine
ore processing and production facility, each collection of ``carbon
processes without mercury retorts'' at a gold mine ore processing and
production facility, and each collection of ``non-carbon concentrate
processes'' at a gold mine ore processing and production facility, as
defined in Sec. 63.11651.
(1) An affected source is existing if you commenced construction or
reconstruction of the affected source on or before April 28, 2010.
(2) An affected source is new if you commenced construction or
reconstruction of the affected source after April 28, 2010.
(c) This subpart does not apply to research and development
facilities, as defined in section 112(c)(7) of the Clean Air Act (CAA).
(d) If you own or operate a source subject to this subpart, you
must have or you must obtain a permit under 40 CFR part 70 or 40 CFR
part 71.
Sec. 63.11641 What are my compliance dates?
(a) If you own or operate an existing affected source, you must
comply with the applicable provisions of this subpart no later than
February 17, 2014.
(b) If you own or operate a new affected source, and the initial
startup of your affected source is on or before February 17, 2011, you
must comply with the provisions of this subpart no later than February
17, 2011.
(c) If you own or operate a new affected source, and the initial
startup of your affected source is after February 17, 2011, you must
comply with the provisions of this subpart upon startup of your
affected source.
Standards and Compliance Requirements
Sec. 63.11645 What are my mercury emission standards?
(a) For existing ore pretreatment processes, you must emit no more
than 127 pounds of mercury per million tons of ore processed.
(b) For existing carbon processes with mercury retorts, you must
emit no more than 2.2 pounds of mercury per ton of concentrate
processed.
(c) For existing carbon processes without mercury retorts, you must
emit no more than 0.17 pounds of mercury per ton of concentrate
processed.
(d) For existing non-carbon concentrate processes, you must emit no
more than 0.2 pounds of mercury per ton of concentrate processed.
(e) For new ore pretreatment processes, you must emit no more than
84 pounds of mercury per million tons of ore processed.
(f) For new carbon processes with mercury retorts, you must emit no
more than 0.8 pounds of mercury per ton of concentrate processed.
(g) For new carbon processes without mercury retorts, you must emit
no more than 0.14 pounds of mercury per ton of concentrate processed.
(h) For new non-carbon concentrate processes, you must emit no more
than 0.1 pounds of mercury per ton of concentrate processed.
(i) The standards set forth in this section apply at all times.
Sec. 63.11646 What are my compliance requirements?
(a) Except as provided in paragraph (b) of this section, you must
conduct a mercury compliance emission test within 180 days of the
compliance date for all process units at new and existing affected
sources according to the requirements in paragraphs (a)(1) through
(a)(13) of this section. This compliance testing must be repeated
annually thereafter, with no two consecutive annual compliance tests
occurring less than 3 months apart or more than 15 months apart.
(1) You must determine the concentration of mercury and the
volumetric flow rate of the stack gas according to the following test
methods and procedures:
(i) Method 1 or 1A (40 CFR part 60, appendix A-1) to select
sampling port locations and the number of traverse points in each stack
or duct. Sampling sites must be located at the outlet of the control
device (or at the outlet of the emissions source if no control device
is present) and prior to any releases to the atmosphere.
(ii) Method 2, 2A, 2C, 2D, 2F (40 CFR part 60, appendix A-1), or
Method 2G (40 CFR part 60, appendix A-2) to determine the volumetric
flow rate of the stack gas.
(iii) Method 3, 3A, or 3B (40 CFR part 60, appendix A-2) to
determine the dry
[[Page 9481]]
molecular weight of the stack gas. You may use ANSI/ASME PTC 19.10,
``Flue and Exhaust Gas Analyses'' (incorporated by reference-see Sec.
63.14) as an alternative to EPA Method 3B.
(iv) Method 4 (40 CFR part 60, appendix A-3) to determine the
moisture content of the stack gas.
(v) Method 29 (40 CFR part 60, appendix A-8) to determine the
concentration of mercury, except as provided in paragraphs (a)(1)(vi)
and (vii) of this section.
(vi) Upon approval by the permitting authority, ASTM D6784;
``Standard Test Method for Elemental, Oxidized, Particle-Bound and
Total Mercury in Flue Gas Generated from Coal-Fired Stationary Sources
(Ontario Hydro Method)'' (incorporated by reference--see Sec. 63.14)
may be used as an alternative to Method 29 to determine the
concentration of mercury.
(vii) Upon approval by the permitting authority, Method 30B (40 CFR
part 60, appendix A-8) may be used as an alternative to Method 29 to
determine the concentration of mercury for those process units with
relatively low particulate-bound mercury as specified in Section 1.2 of
Method 30B.
(2) A minimum of three test runs must be conducted for each
performance test of each process unit. Each test run conducted with
Method 29 must collect a minimum sample volume of 0.85 dry standard
cubic meters (30 dry standard cubic feet). If conducted with Method 30B
or ASTM D6784, determine sample time and volume according to the
testing criteria set forth in the relevant method. If the emission
testing results for any of the emission points yields a non-detect
value, then the minimum detection limit (MDL) must be used to calculate
the mass emissions rate (lb/hr) used to calculate the emissions factor
(lb/ton) for that emission point and, in turn, for calculating the sum
of the emissions (in units of pounds of mercury per ton of concentrate,
or pounds of mercury per million tons of ore) for all emission points
subject to the emission standard for determining compliance. If the
resulting mercury emissions are greater than the MACT emission
standard, the owner or operator may use procedures that produce lower
MDL results and repeat the mercury emissions testing one additional
time for any emission point for which the measured result was below the
MDL. If this additional testing is performed, the results from that
testing must be used to determine compliance (i.e., there are no
additional opportunities allowed to lower the MDL).
(3) Performance tests shall be conducted under such conditions as
the Administrator specifies to the owner or operator based on
representative performance of the affected source for the period being
tested. Upon request, the owner or operator shall make available to the
Administrator such records as may be necessary to determine the
conditions of performance tests. Performance tests must be conducted
under operating conditions (including process or production
throughputs) that are based on representative performance. Record and
report to the permit authority the process throughput for each test
run. For sources with multiple emission units (e.g., two roasters, or a
furnace, electrowinning circuit and a mercury retort) ducted to a
common control device and stack, compliance testing must be performed
either by conducting a single compliance test with all affected
emissions units in operation or by conducting a separate compliance
test on each emissions unit. Alternatively, the owner or operator may
request approval from the permit authority for an alternative testing
approach. If the units are tested separately, any emissions unit that
is not tested initially must be tested as soon as is practicable. If
the performance test is conducted when all affected units are
operating, then the number of hours of operation used for calculating
emissions pursuant to paragraphs (a)(6) and (7) of this section must be
the total number of hours for the unit that has the greatest total
operating hours for that period of time, or based on an appropriate
alternative method approved by the permit authority to account for the
hours of operation for each separate unit in these calculations.
(4) Calculate the mercury emission rate (lb/hr), based on the
average of 3 test run values, for each process unit (or combination of
units that are ducted to a common stack and are tested when all
affected sources are operating pursuant to paragraph (a)(3) of this
section) using Equation (1) of this section:
[GRAPHIC] [TIFF OMITTED] TR17FE11.003
Where:
E = mercury emissions in lb/hr;
Cs = concentration of mercury in the stack gas, in grains per dry
standard cubic foot (gr/dscf);
Qs = volumetric flow rate of the stack gas, in dry standard cubic
feet per hour; and
K = conversion factor for grains (gr) to pounds (lb), 1.43 x
10-4.
(5) Monitor and record the number of one-hour periods each process
unit operates during each month.
(6) For the initial compliance determination for both new and
existing sources, determine the total mercury emissions for all the
full calendar months between the compliance date and the date of the
initial compliance test by multiplying the emission rate in lb/hr for
each process unit (or combination of units ducted to a common stack
that are tested together) by the number of one-hour periods each
process unit (or the unit that had the greatest total operating hours
among the combination of multiple units with one stack that are tested
together, or an alternative method approved by the permit authority,
pursuant to paragraph (a)(3) of this section) operated during those
full calendar months prior to the initial compliance test. This initial
period must include at least 1 full month of operations. After the
initial compliance test, for subsequent compliance tests, determine the
mercury mass emissions for the 12 full calendar months prior to the
compliance test in accordance with the procedures in paragraph (a)(7)
of this section. Existing sources may use a previous emission test for
their initial compliance determination in lieu of conducting a new test
if the test was conducted within one year of the compliance date using
the methods specified in paragraphs (a)(1) through (a)(4) of this
section, and the tests were representative of current operating
processes and conditions. If a previous test is used for their initial
compliance determination, 3 to 12 full months of data on hours of
operation and production (i.e., million tons of ore or tons of
concentrate), including the month the test was conducted, must be used
to calculate the emissions rate (in units of pounds of mercury per
million tons of ore for the ore pretreatment affected sources, or in
units of pounds of mercury per tons of concentrate for the other
affected sources).
(7) For compliance determinations following the initial compliance
test for new and existing sources, determine the total mercury mass
emissions for each process unit for the 12 full calendar
[[Page 9482]]
months preceding the performance test by multiplying the emission rate
in lb/hr for each process unit (or combination of units ducted to a
common stack that are tested together) by the number of one-hour
periods each process unit (or the unit that had the greatest total
operating hours among the combination of multiple units with one stack
that are tested together, or an alternative method approved by the
permit authority, pursuant to paragraph (a)(3) of this section)
operated during the 12 full calendar months preceding the completion of
the performance tests.
(8) You must install, calibrate, maintain and operate an
appropriate weight measurement device, mass flow meter, or densitometer
and volumetric flow meter to measure ore throughput for each roasting
operation and autoclave and calculate hourly, daily and monthly totals
in tons of ore according to paragraphs (a)(8)(i) and (a)(8)(ii) of this
section.
(i) Measure the weight or the density and volumetric flow rate of
the oxidized ore slurry as it exits the roaster oxidation circuit(s)
and before the carbon-in-leach tanks. Alternatively, the weight of the
ore can be measured ``as fed'' if approved by the permit authority as
an acceptable equivalent method to measure amount of ore processed.
(ii) Measure the weight or the density and volumetric flow rate of
the ore slurry as it is fed to the autoclave(s). Alternatively, the
weight or the density and volumetric flow rate of the oxidized ore
slurry can be measured as it exits the autoclave and before the carbon-
in-leach tanks if approved by the permit authority as an acceptable
equivalent method to measure amount of ore processed.
(9) Measure the weight of concentrate (produced by electrowinning,
Merrill Crowe process, gravity feed, or other methods) using weigh
scales for each batch prior to processing in mercury retorts or melt
furnaces. For facilities with mercury retorts, the concentrate must be
weighed in the same state and condition as it is when fed to the
mercury retort. For facilities without mercury retorts, the concentrate
must be weighed prior to being fed to the melt furnace before drying in
any ovens. For facilities that ship concentrate offsite, measure the
weight of concentrate as shipped offsite. You must keep accurate
records of the weights of each batch of concentrate processed and
calculate, and record the total weight of concentrate processed each
month.
(10) You must maintain the systems for measuring density,
volumetric flow rate, and weight within 5 percent
accuracy. You must describe the specific equipment used to make
measurements at your facility and how that equipment is periodically
calibrated. You must also explain, document, and maintain written
procedures for determining the accuracy of the measurements and make
these written procedures available to your permitting authority upon
request. You must determine, record, and maintain a record of the
accuracy of the measuring systems before the beginning of your initial
compliance test and during each subsequent quarter of affected source
operation.
(11) Record the weight in tons of ore for ore pretreatment
processes and concentrate for carbon processes with mercury retorts,
carbon processes without mercury retorts, and for non-carbon
concentrate processes on a daily and monthly basis.
(12) Calculate the emissions from each new and existing affected
source for the sum of all full months between the compliance date and
the date of the initial compliance test in pounds of mercury per ton of
process input using the procedures in paragraphs (a)(12)(i) through
(a)(12)(iv) of this section to determine initial compliance with the
emission standards in Sec. 63.11645. This must include at least 1 full
month of data. Or, if a previous test is used pursuant to paragraph
(a)(6) of this section for the initial compliance test, use a period of
time pursuant to paragraph (a)(6) of this section to calculate the
emissions for the affected source. After this initial compliance test
period, determine annual compliance using the procedures in paragraph
(a)(13) of this section for existing sources.
(i) For ore pretreatment processes, divide the sum of mercury mass
emissions (in pounds) from all roasting operations and autoclaves
during the number of full months between the compliance date and the
initial compliance test by the sum of the total amount of gold mine ore
processed (in million tons) in these process units during those same
full months following the compliance date. Or, if a previous test is
used to determine initial compliance, pursuant to paragraph (a)(6) of
this section, then the same 3 to 12 full months of production data
(i.e., million tons of ore) and hours of operation referred to in
paragraph (a)(6) of this section, must be used to determine the
emissions in pounds of mercury per million tons of ore.
(ii) For carbon processes with mercury retorts, divide the sum of
mercury mass emissions (in pounds) from all carbon kilns, preg tanks,
electrowinning, mercury retorts, and melt furnaces during the initial
number of full months between the compliance date and the initial
compliance tests by the total amount of concentrate (in tons) processed
in these process units during those same full months following the
compliance date. If a previous test is used to determine initial
compliance, pursuant to paragraph (a)(6) of this section, then the same
3 to 12 full months of production data (i.e., tons of concentrate) and
hours of operation referred to in paragraph (a)(6) of this section,
must be used to determine the emissions in pounds of mercury per tons
of concentrate.
(iii) For carbon processes without mercury retorts, divide the sum
of mercury mass emissions (in pounds) from all carbon kilns, preg
tanks, electrowinning, and melt furnaces during the initial number of
full months between the compliance date and the initial compliance
tests by the total amount of concentrate (in tons) processed in these
process units during those same full months following the compliance
date. If a previous test is used to determine initial compliance,
pursuant to paragraph (a)(6) of this section, then the same 3 to 12
full months of production data (i.e., tons of concentrate) and hours of
operation referred to in paragraph (a)(6) of this section, must be used
to determine the emissions in pounds of mercury per tons of
concentrate.
(iv) For non-carbon concentrate processes, divide the sum of
mercury mass emissions (in pounds) from mercury retorts and melt
furnaces during the initial number of full months between the
compliance date and the initial compliance tests by the total amount of
concentrate (in tons) processed in these process units during those
same full months following the compliance date. If a previous test is
used to determine initial compliance, pursuant to paragraph (a)(6) of
this section, then the same 3 to 12 full months of production data
(i.e., tons of concentrate) and hours of operation referred to in
paragraph (a)(6) of this section, must be used to determine the
emissions in pounds of mercury per tons of concentrate.
(13) After the initial compliance test, calculate the emissions
from each new and existing affected source for each 12-month period
preceding each subsequent compliance test in pounds of mercury per ton
of process input using the procedures in paragraphs (a)(13)(i) through
(iv) of this section to determine compliance with the emission
standards in Sec. 63.11645.
(i) For ore pretreatment processes, divide the sum of mercury mass
[[Page 9483]]
emissions (in pounds) from all roasting operations and autoclaves in
the 12-month period preceding a compliance test by the sum of the total
amount of gold mine ore processed (in million tons) in that 12-month
period.
(ii) For carbon processes with mercury retorts, divide the sum of
mercury mass emissions (in pounds) from all carbon kilns, preg tanks,
electrowinning, mercury retorts, and melt furnaces in the 12-month
period preceding a compliance test by the total amount of concentrate
(in tons) processed in these process units in that 12-month period.
(iii) For carbon processes without mercury retorts, divide the sum
of mercury mass emissions (in pounds) from all carbon kilns, preg
tanks, electrowinning, and melt furnaces in the 12-month period
preceding a compliance test by the total amount of concentrate (in
tons) processed in these process units in that 12-month period.
(iv) For non-carbon concentrate processes, divide the sum of
mercury mass emissions (in pounds) from mercury retorts and melt
furnaces in the 12-month period preceding a compliance test by the
total amount of concentrate (in tons) processed in these process units
in that 12-month period.
(b) At all times, you must operate and maintain any affected
source, including associated air pollution control equipment and
monitoring equipment, in a manner consistent with safety and good air
pollution control practices for minimizing emissions. Determination of
whether such operation and maintenance procedures are being used will
be based on information available to the Administrator which may
include, but is not limited to, monitoring results, review of operation
and maintenance procedures, review of operation and maintenance
records, and inspection of the source.
Sec. 63.11647 What are my monitoring requirements?
(a) Except as provided in paragraph (a)(5) of this section, you
must monitor each roaster for mercury emissions using one of the
procedures in paragraphs (a)(1), (a)(2), or (a)(3) of this section and
establish operating limits for mercury concentration as described in
paragraph (a)(4) of this section.
(1) Perform sampling and analysis of the roaster's exhaust for
mercury concentration using EPA Performance Specification 12B (40 CFR
part 60, appendix B and Procedure 5 of appendix F) or EPA Method 30B
(40 CFR part 60, appendix A-8) at least twice per month. A minimum of
two measurements must be taken per month that are at least 11 days
apart from other consecutive tests. The mercury concentration must be
maintained below the operating limit established in paragraph (a)(4) of
this section. The results of the sampling must be obtained within 72
hours of the time the sample is taken.
(i) To determine the appropriate sampling duration, you must review
the available data from previous stack tests to determine the upper
99th percentile of the range of mercury concentrations in the exit
stack gas. Based on this upper end of expected concentrations, select
an appropriate sampling duration that is likely to provide a valid
sample and not result in breakthrough of the sampling tubes. If
breakthrough of the sampling tubes occurs, you must re-sample within 7
days using a shorter sampling duration.
(ii) If any mercury concentration measurement from the twice per
month sampling with PS 12B or Method 30B is higher than the operating
limit, the exceedance must be reported to the permit authority as a
deviation and corrective actions must be implemented within 48 hours
upon receipt of the sampling results. Moreover, within 96 hours of the
exceedance, the owner or operator must measure the concentration again
(with PS 12B (40 CFR part 60, appendix B and Procedure 5 of appendix
F), Method 30B or Method 29 (40 CFR part 60, appendix A-8), or ASTM
D6784(incorporated by reference--see Sec. 63.14)) and demonstrate to
the permit authority that the mercury concentration is no higher than
the operating limit, or inform the permit authority that the limit
continues to be exceeded. If the measured mercury concentration exceeds
the operating limit for mercury concentration after these 96 hours, the
exceedance must be reported as a deviation within 24 hours to the
permitting authority. The owner or operator must conduct a full
compliance test pursuant to Sec. 63.11646(a) for the roaster
operations within 40 days to determine if the affected source is in
compliance with the MACT emission standard. For facilities that have
roasters and autoclaves, the owner or operator can use the results of
the previous compliance test for the autoclaves to determine the
emissions for those process units to be used in the calculations of the
emissions for the affected source. If the source is determined to be in
compliance, the compliance test may also be used to establish a new
operating limit for mercury concentration (in accordance with paragraph
(e) of this section).
(2) Install, operate, calibrate, and maintain a continuous
emissions monitoring system (CEMS) to continuously measure the mercury
concentration in the final exhaust stream from each roaster according
to the requirements of Performance Specification 12A (40 CFR part 60,
appendix B) except that calibration standards traceable to the National
Institute of Standards and Technology are not required. You must
perform a data accuracy assessment of the CEMS according to section 5
of Appendix F in part 60 and follow the applicable monitoring
requirements in Sec. 63.8 as provided in Table 1 to subpart EEEEEEE.
(i) You must continuously monitor the daily average mercury
concentration from the roaster and maintain the daily average
concentration below the operating limit established in paragraph (a)(4)
of this section.
(ii) If the daily average mercury concentration from the CEMs is
higher than the operating limit, the exceedance must be reported to the
permit authority as a deviation and corrective actions must be
implemented within 48 hours upon receipt of the sampling results.
Moreover, within 96 hours of the exceedance, the owner or operator must
measure the concentration again (with the CEMs (40 CFR part 60,
appendix B and Procedure 5 of appendix F) and demonstrate to the permit
authority that the mercury concentration is no higher than the
operating limit, or inform the permit authority that the limit
continues to be exceeded. If the measured mercury concentration exceeds
the operating limit for mercury concentration after these 96 hours, the
exceedance must be reported as a deviation within 24 hours to the
permitting authority, and the owner or operator must conduct a full
compliance test pursuant to Sec. 63.11646(a) for the roaster
operations within 40 days to determine if the affected source is in
compliance with the MACT emission standard. For facilities that have
roasters and autoclaves, the owner or operator can use the results of
the previous compliance test for the autoclaves to determine the
emissions for those process units to be used in the calculations of the
emissions for the affected source. If the source is determined to be in
compliance, the compliance test results may also be used to establish a
new operating limit for mercury concentration (in accordance with
paragraph (e) of this section).
(iii) You must submit a monitoring plan that includes quality
assurance and quality control (QA/QC) procedures sufficient to
demonstrate the accuracy of
[[Page 9484]]
the CEMS to your permitting authority for approval 180 days prior to
your initial compliance test. At a minimum, the QA/QC procedures must
include daily calibrations and an annual accuracy test for the CEMS.
(3) Continuously measure the mercury concentration in the final
exhaust stream from each roaster using EPA Performance Specification
12B (40 CFR part 60 appendix B and Procedure 5 of appendix F).
(i) You must continuously measure the mercury concentration in the
roaster exhaust and maintain the average daily mercury concentration
below the operating limit established in paragraph (a)(4) of this
section. To determine the appropriate sampling duration, you must
review the available data from previous stack tests to determine the
upper 99th percentile of the range of mercury concentrations in the
exit stack gas. Based on this upper end of expected concentrations,
select an appropriate sampling duration that is likely to provide a
valid sample and not result in breakthrough of the sampling tubes. If
breakthrough of the sampling tubes occurs, you must re-sample within 7
days using a shorter sampling duration.
(ii) If the daily average mercury concentration is higher than the
operating limit, the exceedance must be reported to the permit
authority as a deviation and corrective actions must be implemented
within 48 hours upon receipt of the sampling results. Moreover, within
96 hours of the exceedance, the owner or operator must measure the
concentration again with PS 12B (40 CFR part 60, appendix B and
Procedure 5 of appendix F), Method 30B or Method 29 (40 CFR part 60,
appendix A-8), or ASTM D6784(incorporated by reference--see Sec.
63.14) and demonstrate to the permit authority that the mercury
concentration is no higher than the operating limit, or inform the
permit authority that the limit continues to be exceeded. If the
measured mercury concentration exceeds the operating limit for mercury
concentration after these 96 hours, the exceedance must be reported as
a deviation within 24 hours to the permitting authority and the owner
or operator must conduct a full compliance test pursuant to Sec.
63.11646(a) for the roaster operations within 40 days to determine if
the affected source is in compliance with the MACT emission standard.
For facilities that have roasters and autoclaves, the owner or operator
can use the results of the previous compliance test for the autoclaves
to determine the emissions for those process units to be used in the
calculations of the emissions for the affected source. If the source is
determined to be in compliance, the compliance test results may also be
used to establish a new operating limit for mercury concentration (in
accordance with paragraph (e) of this section).
(4) Use Equation (2) of this section to establish an upper
operating limit for mercury concentration as determined by using the
procedures in paragraphs (a)(1), (a)(2), or (a)(3) of this section
concurrently while you are conducting your annual compliance
performance stack tests according to the procedures in Sec.
63.11646(a).
[GRAPHIC] [TIFF OMITTED] TR17FE11.004
Where:
OLR = mercury concentration operating limit for the roaster (or
roasters that share a common stack) (in micrograms per cubic meter);
Ctest = average mercury concentration measured by the
monitoring procedures (PS 12A or PS 12B or 30B) during the
compliance performance stack test (in micrograms per cubic meter);
EL = emission standard for ore pretreatment processes (in lb/million
tons of ore);
CT = compliance test results for ore pretreatment processes (in lb/
million tons of ore).
(5) For roasters that utilize calomel-based mercury control systems
for emissions controls, you are not required to perform the monitoring
for mercury emissions in paragraphs (a)(1), (a)(2), or (a)(3) of this
section if you demonstrate to the satisfaction of your permitting
authority that mercury emissions from the roaster are less than 10
pounds of mercury per million tons of ore throughput. If you make this
demonstration, you must conduct the parametric monitoring as described
below in paragraphs (b) and (c) of this section.
(i) The initial demonstration must include three or more
consecutive independent stack tests for mercury at least one month
apart on the roaster exhaust stacks. Subsequent demonstrations may be
based upon the single stack test required in paragraph (a) of section
Sec. 63.11646. The results of each of the tests must be less than 10
pounds of mercury per million tons of ore. The testing must be
performed according to the procedures in Sec. 63.11646(a)(1) through
(a)(4) to determine mercury emissions in pounds per hour.
(ii) Divide the mercury emission rate in pounds per hour by the ore
throughput rate during the test expressed in millions of tons per hour
to determine the emissions in pounds per million tons of ore.
(b) For facilities with roasters and a calomel-based mercury
control system that choose to monitor for mercury emissions using the
procedures in paragraph (a)(1) of this section or that qualify for and
choose to follow the requirements in paragraph (a)(5) of this section,
you must establish operating parameter limits for scrubber liquor flow
(or line pressure) and scrubber inlet gas temperature and monitor these
parameters. You may establish your operating parameter limits from the
initial compliance test, according to the manufacturer's
specifications, or based on limits established by the permitting
authority. If you choose to establish your operating parameter limits
from the initial compliance test, monitor the scrubber liquor flow (or
line pressure) and scrubber inlet gas temperature during each run of
your initial compliance test. The minimum operating limit for scrubber
liquor flow rate (or line pressure) is either the lowest value during
any run of the initial compliance test or 10 percent less than the
average value measured during the compliance test, and your maximum
scrubber inlet temperature limit is the highest temperature measured
during any run of the initial compliance test or 10 percent higher than
the average value measured during the compliance test. You must monitor
the scrubber liquor flow rate (or line pressure) and scrubber inlet gas
temperature hourly and maintain the scrubber liquor flow (or line
pressure) at or above the established operating parameter and maintain
the inlet gas temperature below the established operating parameter
limit.
(c) For facilities with roasters and a calomel-based mercury
control system that choose to monitor for mercury emissions using the
procedures in paragraph (a)(1) of this section or that qualify for and
follow the requirements in paragraph (a)(5) of this section, you must
establish operating parameter ranges for mercuric ion and chloride ion
concentrations or for oxidation reduction potential and pH using the
[[Page 9485]]
procedures in paragraph (c)(1) or (c)(2) of this section respectively.
(1) Establish the mercuric ion concentration and chloride ion
concentration ranges for each calomel-based mercury control system. The
mercuric ion concentration and chloride ion concentration ranges for
each calomel-based mercury control system must be based on the
manufacturer's specifications, or based on approval by your permitting
authority. Measure the mercuric ion concentration and chloride ion
concentrations at least once during each run of your initial compliance
test. The measurements must be within the established concentration
range for mercuric ion concentration and chloride ion concentration.
Subsequently, you must sample at least once daily and maintain the
mercuric ion concentration and chloride ion concentrations within their
established range.
(2) Establish the oxidation reduction potential and pH range for
each calomel-based mercury control system. The oxidation reduction
potential and pH range for each calomel-based mercury control system
must be based on the manufacturer's specifications, or based on
approval by your permitting authority. Install monitoring equipment to
continuously monitor the oxidation reduction potential and pH of the
calomel-based mercury control system scrubber liquor. Measure the
oxidation reduction potential and pH of the scrubber liquor during each
run of your initial compliance test. The measurements must be within
the established range for oxidation reduction potential and pH.
Subsequently, you must monitor the oxidation reduction potential and pH
of the scrubber liquor continuously and maintain it within the
established operating range.
(d) If you have an exceedance of a control device operating
parameter range provided in paragraphs (b) or (c) of this section, you
must take corrective action and bring the parameters back into the
established parametric ranges. If the corrective actions taken
following an exceedance do not result in the operating parameter value
being returned within the established range within 48 hours, a mercury
concentration measurement (with PS 12B or PS 12A CEMS (40 CFR part 60,
appendix B and Procedure 5 of appendix F), Method 30B or Method 29 (40
CFR part 60, appendix A-8), or ASTM D6784 (incorporated by reference--
see Sec. 63.14)) must be made to determine if the operating limit for
mercury concentration is being exceeded. The measurement must be
performed and the mercury concentration determined within 48 hours
(after the initial 48 hours, or a total of 96 hours from the time the
parameter range was exceeded). If the measured mercury concentration
meets the operating limit for mercury concentration established under
Sec. 63.11647(a)(4), the corrective actions are deemed successful, and
the owner or operator can request the permit authority to establish a
new limit or range for the parameter. If the measured mercury
concentration exceeds the operating limit for mercury concentration
after these 96 hours, the exceedance must be reported as a deviation
within 24 hours to the permitting authority and the owner or operator
must conduct a full compliance test pursuant to Sec. 63.11646(a) for
the roaster operations within 40 days to determine if the affected
source is in compliance with the MACT emission standard. For facilities
that have roasters and autoclaves, the owner or operator can use the
results of the previous compliance test for the autoclaves to determine
the emissions for those process units to be used in the calculations of
the emissions for the affected source. If the source is determined to
be in compliance with the MACT emission standard, the compliance test
may also be used to establish a new operating limit for mercury
concentration (see paragraph (e) of this section).
(e) You may submit a request to your permitting authority for
approval to change the operating limits established under paragraph
(a)(4) of this section for the monitoring required in paragraph
(a)(1),(a)(2), or (a)(3) of this section. In the request, you must
demonstrate that the proposed change to the operating limit detects
changes in levels of mercury emission control. An approved change to
the operating limit under this paragraph only applies until a new
operating limit is established during the next annual compliance test.
(f) You must monitor each process unit at each new and existing
affected source that uses a carbon adsorber to control mercury
emissions using the procedures in paragraphs (f)(1) or (f)(2) of this
section. A carbon adsorber may include a fixed carbon bed, carbon
filter packs or modules, carbon columns, and other variations.
(1) Continuously sample and analyze the exhaust stream from the
carbon adsorber for mercury using Method 30B (40 CFR part 60, appendix
A-8) for a duration of at least the minimum sampling time specified in
Method 30B and up to one week that includes the period of the annual
performance test.
(i) Establish an upper operating limit for the process as
determined using the mercury concentration measurements from the
sorbent trap (Method 30B) as calculated from Equation (3) of this
section.
[GRAPHIC] [TIFF OMITTED] TR17FE11.005
Where:
OLC = mercury concentration operating limit for the carbon adsorber
control device on the process as measured using the sorbent trap,
(micrograms per cubic meter);
Ctrap = average mercury concentration measured using the
sorbent trap during the week that includes the compliance
performance test, (micrograms per cubic meter);
EL = emission standard for the affected sources (lb/ton of
concentrate);
CT = compliance test results for the affected sources (lb/ton of
concentrate).
(ii) Sample and analyze the exhaust stream from the carbon adsorber
for mercury at least monthly using Method 30B (40 CFR part 60, appendix
A-8). When the mercury concentration reaches 75 percent of the
operating limit, begin weekly sampling and analysis. When the mercury
concentration reaches 90 percent of the operating limit, replace the
carbon in the carbon adsorber within 30 days. If mercury concentration
exceeds the operating limit, change the carbon in the carbon adsorber
within 30 days and report the deviation to your permitting authority.
(2) Conduct an initial sampling of the carbon in the carbon bed for
mercury 90 days after the replacement of the carbon. A representative
sample must be collected from the inlet of the bed and the exit of the
bed and analyzed using SW-846 Method 7471B (incorporated by reference--
see Sec. 63.14). The depth to which the sampler is inserted must be
recorded. The design capacity is established by calculating the average
carbon loading from the inlet and outlet measurements. Sampling and
analysis
[[Page 9486]]
of the carbon bed for mercury must be performed quarterly thereafter.
When the carbon loading reaches 50 percent of the design capacity of
the carbon, monthly sampling must be performed until 90 percent of the
carbon loading capacity is reached. The carbon must be removed and
replaced with fresh carbon no later than 30 days after reaching 90
percent of capacity. For carbon designs where there may be multiple
carbon columns or beds, a representative sample may be collected from
the first and last column or bed instead of the inlet or outlet. If the
carbon loading exceeds the design capacity of the carbon, change the
carbon within 30 days and report the deviation to your permitting
authority.
(g) You must monitor gas stream temperature at the inlet to the
carbon adsorber for each process unit (i.e., carbon kiln, melt furnace,
etc.) equipped with a carbon adsorber. Establish a maximum value for
the inlet temperature either during the annual performance test
(required in Sec. 63.11646(a)), according to the manufacturer's
specifications, or as approved by your permitting authority. If you
choose to establish the temperature operating limit during the
performance test, establish the temperature operating limit based on
either the highest reading during the test or at 10[deg]F higher than
the average temperature measured during the performance test. Monitor
the inlet temperature once per shift. If an inlet temperature exceeds
the temperature operating limit, you must take corrective actions to
get the temperature back within the parameter operating limit within 48
hours. If the exceedance persists, within 144 hours of the exceedance,
you must sample and analyze the exhaust stream from the carbon adsorber
using Method 30B (40 CFR part 60, appendix A-8) and compare to an
operating limit (calculated pursuant to (f)(1)(i)) or you must conduct
carbon sampling pursuant to (f)(2) of this section. If the
concentration measured with Method 30B is below 90 percent of the
operating limit or the carbon sampling results are below 90 percent of
the carbon loading capacity, you may set a new temperature operating
limit 10[deg]F above the previous operating limit or at an alternative
level approved by your permit authority. If the concentration is above
90 percent of the operating limit or above 90 percent of the carbon
loading capacity you must change the carbon in the bed within 30 days
and report the event to your permitting authority, and reestablish an
appropriate maximum temperature limit based on approval of your permit
authority.
(h) For each wet scrubber at each new and existing affected source
not followed by a mercury control system, you must monitor the water
flow rate (or line pressure) and pressure drop. Establish a minimum
value as the operating limit for water flow rate (or line pressure) and
pressure drop either during the performance test required in Sec.
63.11646(a), according to the manufacturer's specifications, or as
approved by your permitting authority. If you choose to establish the
operating limit based on the results of the performance test, the new
operating limit must be established based on either the lowest value
during any test run or 10 percent less than the average value measured
during the test. For wet scrubbers on an autoclave, establish the
pressure drop range according to manufacturer's specifications. You
must monitor the water flow rate and pressure drop once per shift and
take corrective action within 24 hours if any daily average is less
than the operating limit. If the parameters are not in range within 72
hours, the owner or operator must report the deviation to the
permitting authority and perform a compliance test for the process
unit(s) controlled with the wet scrubber that has the parameter
exceedance within 40 days to determine if the affected source is in
compliance with the MACT limit. For the other process units included in
the affected source, the owner or operator can use the results of the
previous compliance test to determine the emissions for those process
units to be used in the calculations of the emissions for the affected
source.
(i) You may conduct additional compliance tests according to the
procedures in Sec. 63.11646 and re-establish the operating limits
required in paragraphs (a) through (c) and (f) through (h) of this
section at any time. You must submit a request to your permitting
authority for approval to re-establish the operating limits. In the
request, you must demonstrate that the proposed change to the operating
limit detects changes in levels of mercury emission control. An
approved change to the operating limit under this paragraph only
applies until a new operating limit is established during the next
annual compliance test.
Sec. 63.11648 What are my notification, reporting, and recordkeeping
requirements?
(a) You must submit the Initial Notification required by Sec.
63.9(b)(2) no later than 120 calendar days after the date of
publication of the final rule in the Federal Register or within 120
days after the source becomes subject to the standard. The Initial
Notification must include the information specified in Sec.
63.9(b)(2)(i) through (b)(2)(iv).
(b) You must submit an initial Notification of Compliance Status as
required by Sec. 63.9(h).
(c) If a deviation occurs during a semiannual reporting period, you
must submit a deviation report to your permitting authority according
to the requirements in paragraphs (c)(1) and (2) of this section.
(1) The first reporting period covers the period beginning on the
compliance date specified in Sec. 63.11641 and ending on June 30 or
December 31, whichever date comes first after your compliance date.
Each subsequent reporting period covers the semiannual period from
January 1 through June 30 or from July 1 through December 31. Your
deviation report must be postmarked or delivered no later than July 31
or January 31, whichever date comes first after the end of the
semiannual reporting period.
(2) A deviation report must include the information in paragraphs
(c)(2)(i) through (c)(2)(iv) of this section.
(i) Company name and address.
(ii) Statement by a responsible official, with the official's name,
title, and signature, certifying the truth, accuracy and completeness
of the content of the report.
(iii) Date of the report and beginning and ending dates of the
reporting period.
(iv) Identification of the affected source, the pollutant being
monitored, applicable requirement, description of deviation, and
corrective action taken.
(d) If you had a malfunction during the reporting period, the
compliance report required in Sec. 63.11648(b) must include the
number, duration, and a brief description for each type of malfunction
which occurred during the reporting period and which caused or may have
caused any applicable emission limitation to be exceeded. The report
must also include a description of actions taken by an owner or
operator during a malfunction of an affected source to minimize
emissions in accordance with Sec. 63.11646(b), including actions taken
to correct a malfunction.
(e) You must keep the records specified in paragraphs (e)(1)
through (e)(3) of this section. The form and maintenance of records
must be consistent with the requirements in section 63.10(b)(1) of the
General Provisions.
(1) As required in Sec. 63.10(b)(2)(xiv), you must keep a copy of
each
[[Page 9487]]
notification that you submitted to comply with this subpart and all
documentation supporting any Initial Notification, Notification of
Compliance Status, and semiannual compliance certifications that you
submitted.
(2) You must keep the records of all performance tests,
measurements, monitoring data, and corrective actions required by
Sec. Sec. 63.11646 and 63.11647, and the information identified in
paragraphs (c)(2)(i) through (c)(2)(vi) of this section for each
corrective action required by Sec. 63.11647.
(i) The date, place, and time of the monitoring event requiring
corrective action;
(ii) Technique or method used for monitoring;
(iv) Operating conditions during the activity;
(v) Results, including the date, time, and duration of the period
from the time the monitoring indicated a problem to the time that
monitoring indicated proper operation; and
(vi) Maintenance or corrective action taken (if applicable).
(3) You must keep records of operating hours for each process as
required by Sec. 63.11646(a)(5) and records of the monthly quantity of
ore and concentrate processed or produced as required by Sec.
63.11646(a)(10).
(f) Your records must be in a form suitable and readily available
for expeditious review, according to Sec. 63.10(b)(1). As specified in
Sec. 63.10(b)(1), you must keep each record for 5 years following the
date of each recorded action. You must keep each record onsite for at
least 2 years after the date of each recorded action according to Sec.
63.10(b)(1). You may keep the records offsite for the remaining 3
years.
(g) After December 31, 2011, within 60 days after the date of
completing each performance evaluation conducted to demonstrate
compliance with this subpart, the owner or operator of the affected
facility must submit the test data to EPA by entering the data
electronically into EPA's WebFIRE data base through EPA's Central Data
Exchange. The owner or operator of an affected facility shall enter the
test data into EPA's data base using the Electronic Reporting Tool or
other compatible electronic spreadsheet. Only performance evaluation
data collected using methods compatible with ERT are subject to this
requirement to be submitted electronically into EPA's WebFIRE database.
Other Requirements and Information
Sec. 63.11650 What General Provisions apply to this subpart?
Table 1 to this subpart shows which parts of the General Provisions
in Sec. Sec. 63.1 through 63.16 apply to you.
Sec. 63.11651 What definitions apply to this subpart?
Terms used in this subpart are defined in the Clean Air Act, in
Sec. 63.2, and in this section as follows:
Autoclave means a pressure oxidation vessel that is used to treat
gold ores (primarily sulfide refractory ore) and involves pumping a
slurry of milled ore into the vessel which is highly pressurized with
oxygen and heated to temperatures of approximately 350[deg] to 430[deg]
F.
Calomel-based mercury control system means a mercury emissions
control system that uses scrubbers to remove mercury from the gas
stream of a roaster or combination of roasters by complexing the
mercury from the gas stream with mercuric chloride to form mercurous
chloride (calomel). These scrubbers are also referred to as ``mercury
scrubbers.''
Carbon adsorber means a control device consisting of a single fixed
carbon bed, multiple carbon beds or columns, carbon filter packs or
modules, and other variations that uses activated carbon to remove
pollutants from a gas stream.
Carbon kiln means a kiln or furnace where carbon is regenerated by
heating, usually in the presence of steam, after the gold has been
stripped from the carbon.
Carbon processes with mercury retorts means the affected source
that includes carbon kilns, preg tanks, electrowinning cells, mercury
retorts, and melt furnaces at gold mine ore processing and production
facilities that use activated carbon, or resins that can be used as a
substitute for activated carbon, to recover (adsorb) gold from the
pregnant cyanide solution.
Carbon processes without mercury retorts means the affected source
that includes carbon kilns, preg tanks, electrowinning cells, and melt
furnaces, but has no retorts, at gold mine ore processing and
production facilities that use activated carbon, or resins that can be
used as a substitute for activated carbon, to recover (adsorb) gold
from the pregnant cyanide solution.
Concentrate means the sludge-like material that is loaded with gold
along with various other metals (such as silver, copper, and mercury)
and various other substances, that is produced by electrowinning, the
Merrill-Crowe process, flotation and gravity separation processes.
Concentrate is measured as the input to mercury retorts, or for
facilities without mercury retorts, as the input to melt furnaces
before any drying takes place. For facilities without mercury retorts
or melt furnaces, concentrate is measured as the quantity shipped.
Deviation means any instance where an affected source subject to
this subpart, or an owner or operator of such a source:
(1) Fails to meet any requirement or obligation established by this
subpart, including but not limited to any emissions limitation or work
practice standard;
(2) Fails to meet any term or condition that is adopted to
implement an applicable requirement in this subpart and that is
included in the operating permit for any affected source required to
obtain such a permit; or
(3) Exceeds any operating limit established under this subpart.
Electrowinning means a process that uses induced voltage on anode
and cathode plates to remove metals from the continuous flow of
solution, where the gold in solution is plated onto the cathode. Steel
wool is typically used as the plating surface.
Electrowinning Cells means a tank in which the electrowinning takes
place.
Gold mine ore processing and production facility means any
industrial facility engaged in the processing of gold mine ore that
uses any of the following processes: Roasting operations, autoclaves,
carbon kilns, preg tanks, electrowinning, mercury retorts, or melt
furnaces. Laboratories (see CAA section 112(c)(7)), individual
prospectors, and very small pilot scale mining operations that
processes or produces less than 100 pounds of concentrate per year are
not a gold mine ore processing and production facility. A facility that
produces primarily metals other than gold, such as copper, lead, zinc,
or nickel (where these metals other than gold comprise 95 percent or
more of the total metal production) that may also recover some gold as
a byproduct is not a gold mine ore processing and production facility.
Those facilities whereby 95 percent or more of total mass of metals
produced are metals other than gold, whether final metal production is
onsite or offsite, are not part of the gold mine ore processing and
production source category.
Melt furnace means a furnace (typically a crucible furnace) that is
used for smelting the gold-bearing material recovered from mercury
retorting, or the gold-bearing material from electrowinning, the
Merrill-Crowe
[[Page 9488]]
process, or other processes for facilities without mercury retorts.
Mercury retort means a vessel that is operated under a partial
vacuum at approximately 1,100 [deg] to 1,300 [deg]F to remove mercury
and moisture from the gold bearing sludge material that is recovered
from electrowinning, the Merrill-Crowe process, or other processes.
Mercury retorts are usually equipped with condensers that recover
liquid mercury during the processing.
Merrill-Crowe process means a precipitation technique using zinc
oxide for removing gold from a cyanide solution. Zinc dust is added to
the solution, and gold is precipitated to produce a concentrate.
Non-carbon concentrate processes means the affected source that
includes mercury retorts and melt furnaces at gold mine ore processing
and production facilities that use the Merrill-Crowe process or other
processes and do not use carbon (or resins that substitute for carbon)
to recover (adsorb) gold from the pregnant cyanide solution.
Ore dry grinding means a process in which the gold ore is ground
and heated (dried) prior to additional preheating or prior to entering
the roaster.
Ore preheating means a process in which ground gold ore is
preheated prior to entering the roaster.
Ore pretreatment processes means the affected source that includes
roasting operations and autoclaves that are used to pre-treat gold mine
ore at gold mine ore processing and production facilities prior to the
cyanide leaching process.
Pregnant solution tank (or preg tank) means a storage tank for
pregnant solution, which is the cyanide solution that contains gold-
cyanide complexes that is generated from leaching gold ore with cyanide
solution.
Pregnant cyanide solution means the cyanide solution that contains
gold-cyanide complexes that are generated from leaching gold ore with a
dilute cyanide solution.
Quenching means a process in which the hot calcined ore is cooled
and quenched with water after it leaves the roaster.
Roasting operation means a process that uses an industrial furnace
in which milled ore is combusted across a fluidized bed to oxidize and
remove organic carbon and sulfide mineral grains in refractory gold
ore. The emissions points of the roasting operation subject to this
subpart include ore dry grinding, ore preheating, the roaster stack,
and quenching.
Sec. 63.11652 Who implements and enforces this subpart?
(a) This subpart can be implemented and enforced by the U.S. EPA or
a delegated authority, such as your state, local, or tribal agency. If
the U.S. EPA Administrator has delegated authority to your state,
local, or tribal agency, then that agency has the authority to
implement and enforce this subpart. You should contact your U.S. EPA
Regional Office to find out if this subpart is delegated to your state,
local, or tribal agency.
(b) In delegating implementation and enforcement authority of this
subpart to a state, local, or tribal agency under 40 CFR part 63,
subpart E, the authorities contained in paragraph (c) of this section
are retained by the Administrator of the U.S. EPA and are not
transferred to the state, local, or tribal agency.
(c) The authorities that will not be delegated to state, local, or
tribal agencies are listed in paragraphs (c)(1) through (4) of this
section.
(1) Approval of alternatives to the applicability requirements in
Sec. 63.11640, the compliance date requirements in Sec. 63.11641, and
the applicable standards in Sec. 63.11645.
(2) Approval of an alternative nonopacity emissions standard under
Sec. 63.6(g).
(3) Approval of a major change to a test method under Sec.
63.7(e)(2)(ii) and (f). A ``major change to test method'' is defined in
Sec. 63.90(a).
(4) Approval of a major change to monitoring under Sec. 63.8(f). A
``major change to monitoring'' is defined in Sec. 63.90(a).
(5) Approval of a waiver of recordkeeping or reporting requirements
under Sec. 63.10(f), or another major change to recordkeeping/
reporting. A ``major change to recordkeeping/reporting'' is defined in
Sec. 63.90(a).
Sec. 63.11653 [Reserved]
Tables to Subpart EEEEEEE of Part 63
Table 1 to Subpart EEEEEEE of Part 63--Applicability of General Provisions to Subpart EEEEEE
[As stated in Sec. 63.11650, you must comply with the applicable General Provisions requirements according to
the following table]
----------------------------------------------------------------------------------------------------------------
Citation Subject Applies to subpart EEEEEEE Explanation
----------------------------------------------------------------------------------------------------------------
Sec. 63.1(a)(1), (a)(2), (a)(3), Applicability........ Yes............................
(a)(4), (a)(6), (a)(10)-(a)(12),
(b)(1), (b)(3), (c)(1), (c)(2),
(c)(5), (e).
Sec. 63.1(a)(5), (a)(7)-(a)(9), Reserved............. No.............................
(b)(2), (c)(3), (c)(4), (d).
Sec. 63.2....................... Definitions.......... Yes............................
Sec. 63.3....................... Units and Yes............................
Abbreviations.
Sec. 63.4....................... Prohibited Activities Yes............................
and Circumvention.
Sec. 63.5....................... Preconstruction Yes............................
Review and
Notification
Requirements.
Sec. 63.6(a), (b)(1)-(b)(5), Compliance with Yes............................
(b)(7), (c)(1), (c)(2), (c)(5), Standards and
(e)(1)(iii), (f)(2), (f)(3), (g), Maintenance
(i), (j). Requirements.
Sec. 63.6(e)(1)(i) and (ii), Startup, Shutdown and No............................. Subpart EEEEEEE
(e)(3), and (f)(1). Malfunction standards apply at
Requirements (SSM). all times.
Sec. 63.6(h)(1), (h)(2), Compliance with No............................. Subpart EEEEEEE does
(h)(4),(h)(5)(i), (ii), (iii) and Opacity and Visible not contain opacity
(v), (h)(6)-(h)(9). Emission Limits. or visible emission
limits.
Sec. 63.6(b)(6), (c)(3), (c)(4), Reserved............. No.............................
(d), (e)(2), (e)(3)(ii), (h)(3),
(h)(5)(iv).
Sec. 63.7, except (e)(1)........ Applicability and Yes............................
Performance Test
Dates.
Sec. 63.7(e)(1)................. Performance Testing No.............................
Requirements Related
to SSM.
[[Page 9489]]
Sec. 63.8(a)(1), (b)(1), (f)(1)- Monitoring Yes............................
(5), (g). Requirements.
Sec. 63.8(a)(2), (a)(4), (b)(2)- Continuous Monitoring Yes............................ Except cross
(3), (c), (d), (e), (f)(6), (g). Systems. references to SSM
requirements in
Sec. 63.6(e)(1)
and (3) do not
apply.
Sec. 63.8(a)(3)................. [Reserved]........... No.............................
Sec. 63.9(a), (b)(1), (b)(2)(i)- Notification Yes............................
(v), (b)(4), (b)(5), (c), (d), Requirements.
(e), (g), (h)(1)-(h)(3), (h)(5),
(h)(6), (i), (j).
Sec. 63.9(f).................... ..................... No.............................
Sec. 63.9(b)(3), (h)(4)......... Reserved............. No.............................
Sec. 63.10(a), (b)(1), Recordkeeping and Yes............................
(b)(2)(vi)-(xiv), (b)(3), (c), Reporting
(d)(1)-(4), (e), (f). Requirements.
Sec. 63.10(b)(2)(i)-(v), (d)(5). Recordkeeping/ No.............................
Reporting Associated
with SSM.
Sec. 63.10(c)(2)-(c)(4), (c)(9). Reserved............. No.............................
Sec. 63.11...................... Control Device No.............................
Requirements.
Sec. 63.12...................... State Authority and Yes............................
Delegations.
Sec. Sec. 63.13-63.16.......... Addresses, Yes............................
Incorporation by
Reference,
Availability of
Information,
Performance Track
Provisions.
----------------------------------------------------------------------------------------------------------------
[FR Doc. 2011-2608 Filed 2-16-11; 8:45 am]
BILLING CODE 6560-50-P