Document ID: EPA-R03-OAR-2011-0584-0016
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2012-01-25T05:00Z

ENCLOSURE 3

PUBLIC PARTICIPATION RECORD



As required by 40 CFR 51.102(e), the complete record of testimony is
located at the Department of Environmental Quality.  The department
contact to access this information is the Director, Air Division.

As required by Section 2.1(h) of Appendix V of 40 CFR Part 51, below is
a summary of the testimony received and responses thereto.  Included is
a brief statement of the subject, the identification of the commenter,
the summary of the comment and the response (analysis and action taken).
 Each issue is discussed in light of all of the comments received that
affect that issue.  All comments have been reviewed and responses
developed based on an evaluation of the issues raised in consideration
of the overall goals and objectives of the air quality program and the
intended purpose of the document under review.

1. SUBJECT:  Sulfur dioxide (SO2) emissions.

COMMENTER:  National Park Service

TEXT:  DEQ has proposed addition of a caustic wet scrubber to control
SO2 emissions from the rotary kiln. We agree and fully support this
proposal.

RESPONSE:  Support for the proposal is appreciated.

2. SUBJECT:  Nitrogen oxide (NOX) emissions, cost effectiveness of
selective catalytic reduction (SCR) control.

COMMENTER:  National Park Service

TEXT:  We agree that SCR in a high-dust location on this rotary lime
kiln poses problems that render this approach technically infeasible in
this situation. There is a growing successful track record of SCR use in
the United States that indicates that spent catalyst and ammonia use are
not a significant risk if proper procedures are followed.

The following comments are directed to O-N Minerals' June 4, 2009
response to DEQ as it relates to the cost-effectiveness of a tail-end
SCR system located downstream of the existing baghouse.

Except as noted elsewhere, we accept O-N's estimated costs at face
value, and appreciate their effort to provide that information in such
detail.  We believe that O-N's operating cost for "Supplemental Natural
Gas Firing" may be overstated. We recently received an analysis of
tail-end SCR as it might be applied following a wet scrubber at Basin
Electric Power Cooperative's (BEPC) Leland Olds Station Unit #2 in North
Dakota. In that analysis, BEPC assumed that enough heat could be
recovered that the additional natural gas heating requirement to operate
SCR would be only 50°F. If we compare that Leland Olds estimate to the
200°F increase estimated by O-N, there is the potential to cut natural
gas use by 75%.

We believe that O-N has underestimated the effectiveness of SCR at 80%
control efficiency (305 tpy reduction). It is generally assumed that SCR
can attain at least 90% control--which should be especially likely in a
low-dust location. (The Leland Olds Unit #2 BART analysis assumed 90%
control.) A 90% reduction at O-N could result in up to 340 tpy removal. 
We entered data into a spreadsheet that adjusts the O-N Minerals results
to account for reduced reheat cost and increased NOX removal. The
resulting

$5,100 per ton cost-effectiveness is substantially lower than the $7,500
per ton estimated by O-N Minerals.

Unless a control technology option is determined to be technically
infeasible, the full five-step BART process should be applied. In this
case, tail-end SCR is technically feasible and its costs are low enough
to justify an analysis of the visibility improvements that would result
from its application.

RESPONSE:  The comments offered by the National Park Service (NPS) do
not address--or change--our position as stated in our September 22, 2009
letter responding to NPS’s original comments (provided during NPS’
formal 60-day review period).  As detailed in the letter, SCR has not
been applied to or demonstrated on any kiln (cement or lime) in the
United States. The limited data derived from one European cement kiln
SCR application indicates poor performance (resulting in the SCR being
replaced by SNCR at that location).  We have found no use of SCR on a
lime kiln anywhere.  Accordingly, and as detailed in our 9/22/09 letter,
we find that SCR is not a candidate for technology transfer for BART
consideration.

Nonetheless, we offer the following responses to the points raised by
NPS during the public comment period.

It is uncertain that it would be technically feasible to retrofit the
existing rotary kiln setup at the Strasburg site to accommodate a heat
exchanger for the purpose of heating the baghouse exhaust.  Kiln heat is
already recovered and used to heat limestone in the preheater, so it is
unlikely that there would be enough residual heat to appreciably raise
the baghouse outlet stream temperature.  It is not reasonable to
conclude that O-N’s natural gas heating requirement would be 50°F
(i.e., would be reduced by 75%) based on the requirements of a
coal-fired boiler installation using heat recovery.  

As stated in our 9/22/09 letter, we believe 80% is an appropriate
control efficiency basis for a novel application of SCR such as that on
a lime kiln.  There are data available from one application of SCR to a
kiln (a cement kiln, not a lime kiln) in Europe; the data show that the
SCR achieved an average control efficiency below 50%.  We also note that
several recent entries for applications of SCR on EPA’s RACT/BACT/LAER
Clearinghouse (RBLC) are listed at efficiencies below 90%, which
reflects the process-specific nature of SCR effectiveness.  As we
previously concluded, although SCR is capable of achieving 90% reduction
efficiency in certain applications, it would not be appropriate to apply
that standard to an application of SCR to a lime kiln.

The adjusted cost per ton value ($5,100) presented by NPS is based on
several assumptions.  First, it presumes that a heat exchanger retrofit
is technically feasible on the rotary kiln.  Secondly, NPS’s revised
calculation does not include an adjustment to capital costs to reflect
the cost of the retrofit, if it is feasible.  Finally, the revision is
based on 90% control efficiency, which, as explained above, we find to
be inappropriate in this case.  We therefore do not find the adjusted
cost per ton to be an accurate indicator of SCR control cost in O-N’s
case.

Modeling to assess the visibility improvement likely to result from
application of SCR at O-N has not been conducted, because SCR was
determined to be cost prohibitive.  Additionally, as detailed above, SCR
has not been applied to a lime kiln and we do not find it to be a
candidate for technology transfer consideration under the BART
guidelines.  The analysis conducted to determine BART for O-N is fully
consistent with the five-factor evaluative approach outlined in the BART
guidelines (40 CFR Part 51, Appendix Y).

3. SUBJECT:  Changes to permit conditions and SIP revisions.

COMMENTER:  O-N Minerals (Chemstone) Company

TEXT:  The proposed BART permit contains numerous and specific
conditions that we understand will become part of Virginia's state
implementation plan (SIP) once finalized and approved by the U.S.
Environmental Protection Agency (EPA).  Given that this facility in the
near and long term may undergo permit changes that could result in
future permit conditions that differ from those that incorporated in
this permit, we have previously suggested to DEQ that this permit
contain certain language to allow for permit modifications to minimize
the possibility of having to modify the SIP to accommodate future permit
requirements that may conflict with the BART permit as drafted.  We
appreciate that DEQ has considered this request previously and we
understand some regulatory options may exist to reduce the opportunity
for SIP revisions to be necessary.  However, we remain concerned that
future permitting efforts at the facility may require SIP revisions
before they can be implemented without such permit revision provisions
being incorporated in this permit.  Accordingly, we appreciate DEQ
reconsidering this aspect of the permit during this phase of the
process.

RESPONSE:  We understand O-N’s desire to simplify the administrative
SIP revision process that may be required to address future
modifications at the facility.  Nonetheless, there is no way to avoid
the need for a SIP revision if O-N wishes to change the terms of the
BART permit in the future.  We note that this is the case for any
facility holding an air permit that is part of Virginia’s SIP.  

4. SUBJECT:  Scrubber installation date.

COMMENTER:  O-N Minerals (Chemstone) Company

TEXT:  We previously suggested that Condition 4 be revised to
accommodate the timeframes that the company is working under relative to
installation of an SO2 continuous emission monitoring system (CEMS) and,
if necessary, the design, engineering, permitting and installation of
add-on control equipment as applicable.

DEQ has not agreed to accept our proposed revision to this condition in
prior discussions.  We would prefer not to formally challenge the permit
or delay the revision to the SIP.  However, we cannot agree to the
proposed language of Condition 4 which would require us to install a
scrubber by September 10, 2010.  We must have time to demonstrate that a
scrubber is not necessary and obtain approval for the alternative
control technology.  If we cannot make that demonstration after a
reasonable period (including the requirement to install a CEM for SO2),
we will need adequate time to install the scrubber (assuming we continue
to operate the kiln).  We recommend that Condition 4 clearly state that
we have until September 10, 2011 to seek approval of alternative control
technology.  Therefore, we propose the following revised Condition 4:

4.  Emission Controls: Rotary Kiln - No later than September 10, 2010,
sulfur dioxide (SO2) emissions from the rotary kiln (U5) shall be
controlled to achieve the SO2 limits set forth in this permit.  Unless
the Director, Valley Regional Office, approves inherent process
scrubbing as an alternative control technology by September 10, 2011, a
wet scrubber shall be installed by September 10, 2012.  The wet scrubber
or other technology employed to meet the SO2 emission limits shall be
provided with adequate access for inspection and shall be in operation
when the rotary kiln is operating.

(9VAC5-80-850, 9VAC5-40-7580, 9VAC5-40-7590, and 9VAC5-40-7650)

We also think it is important to state our understanding that the
Director will agree that inherent process scrubbing is an approvable
control technology if our SO2 emissions are consistently within the
permit limits.  We agreed to install a CEMS to provide data to
demonstrate that inherent process scrubbing is effective and capable of
meeting the BART permit without additional controls.  Additionally, we
understand that given the newness of continuous emission monitoring for
SO2, occasional deviations of the SO2 limit should not preclude the
Director from granting approval.

RESPONSE:  We agree that an extension of the deadline to install a
scrubber is appropriate, provided that the emission limits determined to
represent BART for SO2 from the rotary kiln (Condition 23) are met by
September 10, 2010.  Accordingly, we have changed Condition 4 to read:

Emission Controls: Rotary Kiln – No later than September 10, 2010,
sulfur dioxide (SO2) emissions from the rotary kiln (U5) shall be
controlled to achieve the SO2 limits in Condition 23.  Unless the
Director, Valley Regional Office, approves inherent process scrubbing as
an alternative control technology by September 10, 2011, a wet scrubber
shall be installed by August 1, 2012.  The wet scrubber or other
technology employed to meet the SO2 limits shall be provided with
adequate access for inspection and shall be in operation when the rotary
kiln is operating. 

(9 VAC 5-80-850, 9 VAC 5-40-7580, 9 VAC 5-40-7590 and 9 VAC 5-40-7650)

Note that the scrubber installation date has been changed to August 1,
2012 (instead of September 10, 2012 as proposed by O-N) to comply with
Virginia’s BART regulation (9 VAC 5-40-7590.4).

5. SUBJECT:  Wet scrubber.

COMMENTER:  O-N Minerals (Chemstone) Company

TEXT:  We also believe a wet scrubber will be sufficient and ask to
remove the reference to "caustic" in the appropriate conditions
including, but not limited to, Conditions 4, 9, 14, and 26j.

RESPONSE:  As requested, we have removed the word “caustic” from all
references to the scrubber throughout the permit.

TEMPLATES\SOURCE-SPECIFIC\PLN03

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