[Federal Register Volume 71, Number 244 (Wednesday, December 20, 2006)]
[Proposed Rules]
[Pages 76553-76555]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-21404]



  Federal Register / Vol. 71, No. 244 / Wednesday, December 20, 2006 / 
Proposed Rules  

[[Page 76553]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2002-0051; FRL-8256-3]
RIN 2060-AJ78


National Emission Standards for Hazardous Air Pollutants From the 
Portland Cement Manufacturing Industry: Notice of Reconsideration

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of reconsideration.

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SUMMARY: EPA is announcing that it is reconsidering the new source 
standards for mercury and for total hydrocarbons (THC) which are part 
of the National Emission Standards for Hazardous Air Pollutants From 
the Portland Cement Manufacturing Industry, published on December 20, 
2006.

DATES: Comments are due no later than February 20, 2007.

ADDRESSES: EPA has established a docket for this action under Docket ID 
No. EPA-HQ-OAR-2002-0051. All documents in the docket are listed on the 
www.regulations.gov Web site. Although listed in the index, some 
information is not publicly available, e.g., 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 Docket, EPA/DC, EPA 
West, Room 3334, 1301 Constitution Ave., NW., Washington, DC. The 
Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through 
Friday, excluding legal holidays. The telephone number for the Public 
Reading Room is (202) 566-1744, and the telephone number for the EPA 
Docket Center is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: Mr. Keith Barnett, EPA, Office of Air 
Quality Planning and Standards, Sector Policies and Programs Division, 
Metals and Minerals Group (D243-02), Research Triangle Park, NC 27711; 
telephone number (919) 541-5605; facsimile number (919) 541-3207; e-
mail address [email protected].

SUPPLEMENTARY INFORMATION:

I. General Information

    A. Does this action apply to me? Entities potentially affected by 
this action are those that manufacture portland cement. Regulated 
categories and entities include:

                                       Table 1.--Regulated Entities Table
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              Category                   NAICS \1\                  Examples of regulated entities
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Industry............................           32731  Owners or operators of portland cement manufacturing
                                                       plants.
State...............................  ..............  None.
Tribal associations.................  ..............  None.
Federal agencies....................            None  None.
----------------------------------------------------------------------------------------------------------------
\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 regulated by this 
action. This table lists the types of entities that may potentially be 
regulated by this action. To determine whether your facility is 
regulated by this action, you should carefully examine the 
applicability criteria in 40 CFR 63.1340 of the rule. If you have 
questions regarding the applicability of this action to a particular 
entity, consult the person listed in the preceding FOR FURTHER 
INFORMATION CONTACT section.
    Worldwide Web (WWW). In addition to being available in the docket, 
an electronic copy of today's notice will also be available through the 
WWW. Following the Administrator's signature, a copy of this action 
will be posted on EPA's Technology Transfer Network (TTN) policy and 
guidance page for newly proposed or promulgated rules at http://www.epa.gov/ttn/oarpg/. The TTN at EPA's Web site provides information 
and technology exchange in various areas of air pollution control.

Reconsideration of the New Source Mercury Standard

    On December 2, 2005, EPA proposed amendments to the National 
Emission Standards for Hazardous Air Pollutants from the Portland 
Cement Manufacturing Industry (70 FR 72330). Among other things, we 
proposed to amend the emission standards for mercury, hydrogen 
chloride, and total hydrocarbons. We are publishing the final 
amendments in another part of today's Federal Register. The final 
amendments contain a mercury new source standard of 41 [mu]g/dscm for 
cement kilns and kilns/in-line raw mills, or an alternative standard 
requiring application of a limestone wet scrubber with a liquid-to-gas 
ratio of 30 gallons per thousand actual cubic feet per minute of 
exhaust gas with a site-specific numeric limit to be established based 
on that scrubber's performance.
    In this notice, we are ourselves granting reconsideration of this 
new source standard for mercury. We are doing so because we believe 
that reconsideration is compelled by section 307(d)(7)(B) of the Act, 
since the information on which the standard is based arose after the 
period for public comment and (obviously) is of central relevance to 
the rulemaking. In addition, as explained in the following paragraphs, 
we believe that there remain important technical issues which we hope 
to better resolve during the reconsideration process.
    In developing the final amendments, we noted that there are at 
least five cement kilns that have limestone (wet) scrubbers for control 
of SO2. As explained more fully in the preamble to the final 
amendments, based on our experience with utility boilers, as well as on 
general engineering principles, we expect that the scrubbers on cement 
kilns remove mercury, although the amount of removal is uncertain. 
Thus, assuming reductions occur, which we believe to be the case based 
on the limited information in the record, a portland cement kiln 
equipped with a scrubber would have the best performance for mercury 
over time, since variability in mercury emissions attributable to raw 
material and fuel inputs would be controlled in part.
    We have mercury test data from two portland cement kilns equipped 
with wet scrubbers, measured exclusively at the scrubber outlet. These 
data range from 0.42 to 30 [mu]g/dscm, which fall within the range of 
test data from all

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portland cement kilns (those with wet scrubbers and those without wet 
scrubbers). They are among the lowest end-of-stack mercury data in our 
data base (although not the lowest). This could indicate that some 
removal mechanism is involved. Variability of mercury emissions at the 
scrubber-equipped kilns for which we have multiple test data differs by 
orders of magnitude. See Summary of Mercury Test data in Docket EPA-HQ-
OAR-2002-0051.
    As noted above, we have no test data for mercury measured at the 
scrubber inlet. As a result, we cannot, on the basis of the current 
data, determine with absolute certainty if the outlet mercury emissions 
from the wet scrubber-equipped kilns are a result of mercury removal by 
the scrubber, or simply reflect the amounts of mercury in the raw 
materials. Nonetheless, for the reasons described in the preamble to 
the final amendments, we believe, based on the limited information in 
the record, that it is reasonable to find that wet scrubbers remove 
some mercury from cement kiln emissions.
    In the final amendments being published concurrently with this 
notice, we developed an emissions limit of 41 [mu]g/dscm (corrected to 
7 percent oxygen) using the following rationale. First, we limited the 
analysis to data from wet scrubber-equipped kilns regardless of their 
actual outlet emissions levels. Second, we ranked all the wet scrubber 
mercury emissions with the raw mill off--a recurring mode of operation 
for cement kilns reflecting the maximum variability a properly designed 
and operated scrubber-equipped kiln would experience. We then took the 
mean raw mill off value for mercury emissions from the best performing 
wet scrubber-equipped cement kiln in our (limited) data base, and 
multiplied it by a variability factor which accounts for normal, 
unavoidable variation in mercury emissions. This variability factor is 
the standard deviation of the data multiplied by 2.326 to produce the 
99th confidence interval. We looked to all of the data we have from 
cement kilns equipped with wet scrubbers, rather than just to data from 
the single lowest-emitting kiln, because there are too few data points 
from the lowest emitting kiln to properly estimate its variability. The 
result of this analysis is a new source floor of 41 [mu]g/dscm, which 
we then adopted as the new source standard. This standard must be met 
continuously (raw mill on and raw mill off).
    Because of the limited performance data characterizing performance 
of the lowest-emitting scrubber-equipped kiln, we also developed an 
alternative new source mercury floor. The best performing kiln is 
equipped with a wet scrubber. Therefore, if a new source installs a 
properly designed and operated wet scrubber, and is unable to achieve 
the 41 [mu]g/dscm standard, then whatever emission level the source 
achieves (over time, considering all normal sources of variability) 
would become the floor for that source. Based on the design of the wet 
scrubbers that were the basis of the new source floor, this would be a 
packed bed or spray tower wet scrubber with a minimum liquid-to-gas 
ratio of 30 gallons per thousand actual cubic feet of exhaust gas. We 
also adopted this alternative floor as an alternative new source 
emission standard for mercury.
    As noted above, we are ourselves granting reconsideration of the 
new source mercury standard adopted in the final amendments, both due 
to substantive issues relating to performance of wet scrubbers and 
because information about their performance in this industry has not 
been available for public comment. As part of the reconsideration 
process, we are initiating a test program to simultaneously measure 
mercury emissions at the inlet and the outlet of wet scrubbers 
currently installed on cement kilns. By doing so, we expect to be able 
to better resolve the ultimate issues we are reconsidering: the 
appropriateness of the new source standard (and floor), and whether wet 
scrubbers remove mercury from portland cement kiln emissions, and if 
so, to what extent.
    We intend to complete the reconsideration process by December 20, 
2007. When data from the testing process are in hand, we will issue 
another Federal Register notice describing the data and the testing 
process by which the data were obtained, and seek public comment on 
those data and on the testing process. As part of that notice, we may 
also propose to amend the new source standard.
    At the present time, we are also soliciting any data that could 
potentially be relevant in this reconsideration process. Given the 
expedited schedule for reconsideration of the new source mercury 
standard, we are asking that the data be submitted to EPA as soon as 
possible, and no later than February 20, 2007, so that we can properly 
consider it prior to publishing another notice in the Federal Register. 
The data should be submitted to the person and address in the FOR 
FURTHER INFORMATION CONTACT section.

Reconsideration of Existing and New Source Standard Banning Cement Kiln 
Use of Certain Mercury-Containing Fly Ash

    As part of the final rule, EPA adopted a standard for both new and 
existing sources banning the use of utility boiler fly ash in cement 
kilns where the fly ash mercury content has been increased through the 
use of activated carbon or any other sorbent unless the facility can 
demonstrate that the use of that fly ash will not result in an increase 
in mercury emissions over baseline emissions (i.e. emissions not using 
the mercury increased fly ash). See section IV.A.2 to the preamble to 
the final rule. EPA took this action because of the potential for 
significant increases in mercury emissions from cement kilns, and 
because the positive energy and non-air health and environmental 
impacts from current recycling of utility fly ash as feed material in 
cement kilns would not be significantly impeded. Although EPA alluded 
to the possibility of this type of standard at proposal (70 FR 72334), 
we nonetheless believe it appropriate to reconsider the issue to 
provide further opportunity for comment on both the standard and the 
underlying rationale, because we do not feel we have the level of 
analysis we would like to support a beyond-the-floor determination. We 
request that all comments be submitted to EPA no later than February 
20, 2007.

Reconsideration of New Source Standard for THC

    As part of the final amendments, EPA also issued a standard for new 
cement kilns of 20 ppmv (corrected to 7 percent oxygen) or 98 percent 
reduction in THC emissions from uncontrolled levels. This standard is 
based upon the performance of a single cement kiln which has installed 
a regenerative thermal oxidizer (RTO) in series with a wet scrubber 
(which precedes the RTO and enables its performance by preventing 
plugging, fouling, and corrosion of the device). We are ourselves 
granting reconsideration of this standard in this notice. We are doing 
so because we believe that reconsideration is compelled by section 
307(d)(7)(B) of the Act, since the information on which the standard is 
based arose after the period for public comment and is of central 
relevance to the rulemaking.
    We are specifically requesting comment on the new source standard 
itself, as well as on the information upon which the standard is based. 
We also are soliciting data on THC emission levels from preheater/
precalciner cement kilns. We further solicit

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comment as to whether the promulgated standard is appropriate for 
reconstructed new sources, should any be contemplated (it is our 
understanding that all new source cement kilns will be newly 
constructed). We request that all comment be submitted within February 
20, 2007. EPA will evaluate all data and comments received, and 
determine whether in light of those data and comment it is appropriate 
to propose to amend the promulgated standard. If EPA does propose to 
amend the standard, EPA would take final action on the proposal within 
the same one year period that we are allotting for completion of the 
reconsideration process for the new source mercury standard.

How can I get copies of the final amendments and other related 
information?

    EPA has established the official public docket for this rulemaking 
under docket ID No. EPA-HQ-OAR-2002-0051. Information on how to access 
the docket is presented above in the ADDRESSES section. In addition, 
information may be obtained from the Web page for the rulemaking at: 
http://www.epa.gov/ttn/atw/pcem/pcempg.html.

    Dated: December 8, 2006.
Stephen L. Johnson,
Administrator.
[FR Doc. E6-21404 Filed 12-19-06; 8:45 am]
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