The following presents a summary of EPA’s Response
to Comments document that has been release prior to its final action on
the August 22, 2006 Proposed Revisions to Part 75. In anticipation of
the final rule’s release, this summary is primary intended to highlight
many of the apparent changes in the final version from the original
proposal that might be ascertained from the document. As best can be
determined (with occasional commentary):
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Hg Linearity specification – Proposed 5% or 0.6
μg/m3, Final 10% and 0.8% μg/m3
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Proposal intended to clarify validity for
off-line qualified units: To be valid an off-line calibration must
have occurred no more than 26 clock hours preceding that hour and an
on-line calibration must have been performed no more than 26 unit
operating hours preceding that hour. [Commentary: Clarification
does not help a bad decision. It is a shame that EPA has taken such
a good basic idea (off-line calibration qualification) and
convoluted it so badly. It is also a shame that the Agency
misinterpreted our suggestions to fix the issue.]
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Final Rule includes temporary waiver of NIST
traceability for Hg until 2010.
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Technical corrections to Appendix B regarding
system integrity check being a weekly test.
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Data from sorbent trap considered conditionally
valid for up to 720 operating hours after switching sorbent material
prior to RATA. Requirement for new RATA when there is a trap size
change has been removed.
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Appendix A has been revised to allow 336 unit
operating hours to complete an Ontario Hydro or Method 29 Hg RATA
(versus 168 hours). Provision also revised to allow RATA runs prior
to a failed calibration to be kept when Ontario Hydro or Method 29
is used.
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EPA appears to have revised Hg low mass emitter
(LME) provisions in §75.81 to allow a synthetic minor (i.e., to use
the number of permitted hours of operation per year in lieu of 8760
in Equation 1). If heat input is restricted (but not hours) the
annual heat input limit can be divided by the design rated heat
input to determine the number of hours for Equation 1. [Note:
Technically, the term LME is not used in §75.81, which defines
simplified monitoring options for units that can be demonstrated to
have less than 464 ounces of emissions. Unfortunately, the Hg “LME”
provisions are not merely conservative like the LME §75.19 for SO2
and NOX but are based on potential to emit.]
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Rule clarified that LME tests (for identical
units) are only required at common stack.
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“Change in fuel supply” that would trigger Hg
LME re-testing is clarified as a change in coal rank. If there is a
change in the coal rank, a retest would be required within 720
operating hours. The results of the retest could be applied
retroactively. Coal waste products, anthracite culm and bituminous
gob, are considered anthracite and bituminous coal, respectively.
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Reduced LME NOX testing requirements
for units with very low capacity factors (≤2.5% for 3 years and ≤
4.0% for any one year)—single load (75% - 100% of max.) or highest
attainable at time of test
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Final rule allows LME units to use other fuel
sampling methods defined by permit or federal/state regulations to
determine compliance with oil sulfur limits
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Option to use worst case F-factors in lieu of
prorating has been codified. F-factors for sub-bituminous coal, petroleum
coke and TDF have been rounded to nearest multiple of 10.
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To provide a transition period for
implementation, the final rule has been revised to state that the
Protocol Gas Verification Program will take effect on January 1,
2009.
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Cycle time test procedure in Appendix A revised
to be based on time to observe a 95% change from stack gas to
calibration gas instead of calibration gas to stack gas.
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ASTM D5453-05 added to list of acceptable oil
sulfur methods under Appendix D as well as “consensus standards
prescribed for the affected units in 40 CFR Part 75.”
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Reporting requirements for oil sulfur revised
to allow for concentrations lower than 0.01% sulfur.
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Requirement to “normalize” Appendix K results
based on spiking has been removed; albeit, third section spiking is
still required. For paired traps, a second alternative
specification of 0.03 μg/m3 absolute difference has been
added in addition to the 20% RD limit.
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Part 75 has been revised to state that if a
particulate mass CEMS is used then the opacity monitoring
requirements are deemed satisfied.
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Alternatives to dry gas meter “should be
allowed for sorbent trap monitoring systems” (see September 7, 2007
rulemaking).
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Removed requirements to submit EPA for 7610-14
(Certification Application Form). However, hard copies of the
monitoring plan and certification test results are still required to
go to the state and region for both certification and
re-certification events.
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In the Response to Comments, CAMD suggested
that sources that plan to retire a unit prior to January 1, 2010
could petition for relief from Hg monitoring in 2009.
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Requirement to publish requests for the
certification of an alternative monitoring system in the Federal
Register has been eliminated.
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Section 2.1.2 of Appendix E has been modified
to harmonize traverse point selection for NOX-to-heat
input testing for boilers and turbines in light of changes to the
EPA reference methods.
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Final rule allows for EPA Reference Methods 30A
and 30B as alternatives for Hg RATAs.
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Maximum controlled emission rate (MCR) for NOX
allowed or bypass stacks as well as for initial missing data
(provided that data show that controls are properly operating)
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Rule clarified to indicate that MCR may be
implemented on a fuel specific basis.
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Single trap adjustment factor for Appendix K
lowered from 1.222 to 1.111. [Commentary: While it is good that
EPA is allowing the use of data from a single trap when the other
trap is missing or invalidated and that the Agency and that it
addressed its math error, it is completely misguided to think that a
valid measurement needs correcting with a contrived multiplier to
compensate a missing or invalidated one.]
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New sources not required to use XML in 2008.
XML required by all units in 2009.
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Despite significant adverse comments, EPA is
going forward with the requirement for air emission testing bodies (AETBs)
to comply with ASTM D7036 by January 1, 2009.
