[Federal Register Volume 67, Number 85 (Thursday, May 2, 2002)]
[Proposed Rules]
[Pages 22242-22247]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-10333]



  Federal Register / Vol. 67, No. 85 / Thursday, May, 2, 2002 / 
Proposed Rules  

[[Page 22242]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[MT-001-0010; MT-001-0028; FR-174-9]


Approval and Promulgation of Air Quality Implementation Plans; 
Montana; Billings/Laurel Sulfur Dioxide State Implementation Plan

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing to partially approve and limitedly approve 
and limitedly disapprove revisions to the Billings/Laurel sulfur 
dioxide (SO2) State Implementation Plan (SIP) submitted by the State of 
Montana on July 29, 1998 and May 4, 2000. The May 4, 2000 SIP revision 
was submitted to satisfy earlier commitments made by the Governor. The 
intended effect of this action is to make federally enforceable those 
provisions that EPA is proposing to partially and limitedly approve and 
to limitedly approve and to limitedly disapprove those provisions that 
are not approvable. EPA is taking this action under sections 110 and 
179 of the Clean Air Act (Act). In a separate action being published 
today, we are finalizing action on other provisions of the Billings/
Laurel SO2 SIP.

DATES: Written comments must be received on or before July 1, 2002.

ADDRESSES: Written comments may be mailed to Richard R. Long, Director, 
Air and Radiation Program, Mailcode 8P-AR, Environmental Protection 
Agency (EPA), Region 8, 999 18th Street, Suite 300, Denver, Colorado 
80202. Copies of the documents relevant to this action are available 
for public inspection during normal business hours at the Air and 
Radiation Program, Environmental Protection Agency, Region 8, 999 18th 
Street, Suite 300, Denver, Colorado 80202. Copies of the State 
documents relevant to this action are available for public inspection 
at the Montana Department of Environmental Quality, Air and Waste 
Management Bureau, 1520 E. 6th Avenue, Helena, Montana 59620.
    Docket: You can inspect the docket concerning this action, docket 
#R8-99-01, at the Air Program Office, Environmental Protection Agency, 
Region 8, 999 18th Street, Suite 300, Denver, Colorado 80202. Call 
Laurie Ostrand to make an appointment at (303) 312-6437.

FOR FURTHER INFORMATION CONTACT: Laurie Ostrand, EPA, Region 8, (303) 
312-6437.

SUPPLEMENTARY INFORMATION:

Table of Contents

Definitions
I. Summary of EPA's Proposed Action on Portions of the State of 
Montana's July 29, 1998 Submittal and all of the May 4, 2000 
Submittal
II. Background
III. EPA's Proposed Action on Portions of the State of Montana's 
July 29, 1998 Submittal and all of the May 4, 2000 Submittal
    A. Why Is EPA Proposing to Partially and Limitedly Approve and 
Limitedly Disapprove Parts of the July 29, 1998 and May 4, 2000 
Submittals?
    B. What Happens When EPA Approves Parts of the State of 
Montana's Plan?
    C. What Happens When EPA Limitedly Approves and Limitedly 
Disapproves Parts of the State of Montana's Plan?
IV. Request for Public Comments
V. Administrative Requirements

Definitions

    For the purpose of this document, we are giving meaning to certain 
words or initials as follows:
    (i) The words or initials Act or CAA mean or refer to the Clean Air 
Act, unless the context indicates otherwise.
    (ii) The initials CEMS mean or refer to continuous emission 
monitoring systems.
    (iii) The initials CO mean or refer to carbon monoxide.
    (iv) the words EPA, we, us or our mean or refer to the United 
States Environmental Protection Agency.
    (v) The initials FCC mean or refer to fluid catalytic cracking 
unit.
    (vi) The initials FIP mean or refer to Federal Implementation Plan.
    (vii) The initials H2S mean or refer to hydrogen sulfide.
    (viii) The initials MBER mean or refer to the Montana Board of 
Environmental Review.
    (ix) The initials MDEQ mean or refer to the Montana Department of 
Environmental Quality.
    (x) The initials NAAQS mean or refer to the national ambient air 
quality standards.
    (xi) The initials NOX mean or refer to nitrogen oxides.
    (xii) The initials SIP mean or refer to State Implementation Plan.
    (xiii) The initials SO2 mean or refer to sulfur dioxide.
    (xiv) The words State and Montana mean the State of Montana, unless 
the context indicates otherwise.
    (xv) The initials SWS mean or refer to sour water stripper.
    (xvi) The initials TSD mean or refer to the Technical Support 
Document.
    (xvii) The initials YELP mean or refer to the Yellowstone Energy 
Limited Partnership.

I. Summary of EPA's Proposed Action on the Portions of the State of 
Montana's July 29, 1998 Submittal and All of the May 4, 2000 
Submittal

    We are proposing to approve the following provisions:
     YELP's emission limits in section 3(A)(1) through (3) and 
reporting requirements in section 7(C)(1)(b) of YELP's exhibit A 
submitted on May 4, 2000.
     Provisions related to the burning of SWS overheads in the 
F-1 Crude Furnace (and exhausted through the F-2 Crude/Vacuum Heater 
stack) at ExxonMobil in sections 3(E)(4) and 4(E) (excluding ``or in 
the flare'' and ``or the flare'' in both sections), 3(A)(2), and 
3(B)(3) of ExxonMobil's exhibit A, submitted on July 29, 1998 and 
method #6A-1 of attachment #2 of ExxonMobil's exhibit A, submitted on 
May 4, 2000.
     Minor changes in sections 3, 3(A) and 3(B) (only the 
introductory paragraphs); and sections 3(E)(3), 6(B)(7), 7(B)(1)(d), 
7(B)(1)(j), 7(C)(1)(b), 7(C)(1)(d), 7(C)(1)(f), and 7(C)(1)(l) of 
ExxonMobil's exhibit A, submitted on May 4, 2000.
    We are proposing to limitedly approve and limitedly disapprove the 
following provisions:
     Provisions related to the fuel gas combustion emission 
limitations at ExxonMobil in sections 3(B)(2), 4(B), and 6(B)(3) of 
ExxonMobil's exhibit A, submitted on July 29, 1998 and section 3(A)(1) 
of ExxonMobil's exhibit A, submitted on May 4, 2000.
     Provisions related to ExxonMobil's coker CO-boiler 
emission limitation in sections 2(A)(11)(d), 3(B)(1) and 4(C) of 
ExxonMobil's exhibit A, submitted on May 4, 2000.
     Provisions related to the burning of SWS overheads at 
Cenex in sections 3(B)(2) and 4(D) (excluding ``or in the flare'' and 
``or the flare'' in both sections), 3(A)(1)(d), and 4(B) of Cenex's 
exhibit A, submitted on July 29, 1998, and method #6A-1 of attachment 
#2 of Cenex's exhibit A, submitted on May 4, 2000.
    We caution that if sources are subject to more stringent 
requirements under other provisions of the Act (e.g., section 111 new 
source performance standards; Title I, Part C, (prevention of 
significant deterioration); or SIP-approved permit programs under Title 
I, Part A), our approval and limited approval of the SIP (including 
emission limitations and other requirements), would not excuse sources 
from meeting these other more stringent requirements. Also, our action 
on this SIP is not meant to imply any sort of applicability 
determination

[[Page 22243]]

under other provisions of the Act (e.g., section 111; Title I, Part C; 
or SIP-approved permit programs under Title I, Part A).

II. Background

    For a complete discussion of the SO2 SIP issues in the Billings/
Laurel, Montana area see our July 28, 1999 proposed rulemaking action 
(64 FR 40791) (docket # III.A.-2).
    In our July 28, 1999 action, we proposed to conditionally approve 
several provisions of the Billings/Laurel SO2 SIP based on commitments 
from the Governor of Montana to adopt specific enforceable measures by 
a specified date. See the July 28, 1999 Federal Register action, 
starting at page 40802, for a complete discussion of those parts of the 
plan we proposed to conditionally approve. On May 4, 2000, the Governor 
of Montana submitted a SIP revision to fulfill these commitments. Since 
the Governor has fulfilled his commitments, we believe it is not 
appropriate to take final action on the conditional approval. Instead, 
in this document we are proposing action on parts of the July 29, 1998 
submittal (i.e., those parts we proposed to conditionally approve on 
July 28, 1999) and all of the May 4, 2000 submittal. In a separate 
document published today we are taking final action on the remainder of 
the July 29, 1998 submittal.

III. EPA's Proposed Action on Portions of the State of Montana's 
July 29, 1998 Submittal and All of the May 4, 2000 Submittal

A. Why Is EPA Proposing to Partially and Limitedly Approve and 
Limitedly Disapprove Parts of the July 29, 1998 and May 4, 2000 
Submittals?

    For the reasons given below we are proposing to partially and 
limitedly approve and limitedly disapprove parts of the July 29, 1998 
and May 4, 2000 submittals. EPA believes proposing to partially and 
limitedly approve these parts of the Billings/Laurel SO2 SIP meets the 
requirements of section 110(l) of the Act. The provisions of the plan 
that we are proposing to partially and limitedly approve strengthen the 
Montana SIP by providing specific emission limits for several SO2 
sources in Billings/Laurel. This will achieve progress toward attaining 
the SO2 NAAQS.
(1) YELP's Emission Limitations
    In our July 28, 1999 action on the SO2 SIP for the Billings/Laurel, 
MT, area (64 FR 40791, page 40802, middle column), we proposed to 
conditionally approve the SIP as it applies to YELP's emission 
limitations in sections 3(A)(1) through (3) of YELP's exhibit A, based 
on the Governor's commitment to revise these provisions in the YELP 
exhibit. We were concerned that the emission limits in sections 3(A)(1) 
and (2) of YELP's exhibit A were not practically enforceable and that 
the emission limits in section 3(A)(3) were not clearly defined. With 
the May 4, 2000 submittal, the State revised sections 3(A)(1) through 
(3) of the YELP exhibit A to address our concerns and also revised 
section 7(C)(1)(b) to clarify a reporting requirement. We are proposing 
to approve sections 3(A)(1) through (3) and 7(C)(1)(b) of the YELP 
exhibit A. We realize, however, that the time-of-day-restricted and 
pro-rated emission limitations may be somewhat more difficult to 
enforce than a simple fixed limitation. If we were to find that the 
time-of-day-restricted or pro-rated emission limitations were too 
difficult to enforce, we would reconsider our approval. Our 
reconsideration could occur under section 110(k)(6) of the Act or we 
could complete another SIP Call under sections 110(a)(2)(H) and 
110(k)(5) of the Act or take other appropriate action under the Act.
(2) ExxonMobil's F-2 Crude/Vacuum Heater Stack Emission Limitations and 
Attendant Compliance Monitoring Method
    In our July 28, 1999 action (64 FR 40803, middle column) we 
proposed to conditionally approve the SIP as it applies to the F-2 
crude/vacuum heater stack emission limitation and attendant compliance 
monitoring methods--sections 3(E)(4) and 4(E) (only as they apply to 
the F-2 crude/vacuum heater stack), 3(A)(2), 3(B)(3), and attachment 
#2, of ExxonMobil's exhibit A--based on the Governor's commitment to 
revise attachment #2 of the ExxonMobil exhibit.\1\ We were concerned 
that method #6A of attachment #2, which contains the analytical method 
used to determine the H2S concentration in the sour water, was not 
acceptable. (The H2S concentration in the sour water is needed to 
monitor compliance with the F-2 crude/vacuum heater stack emission 
limitation.)
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    \1\ Because we believe the emission limit and compliance 
monitoring method are not separable, in addition to proposing 
conditional approval of the compliance monitoring method in 
attachment #2 of ExxonMobil's exhibit A, we also proposed 
conditional approval of the emission limit and other related 
provisions in the exhibit. In addition, we proposed to conditionally 
approve all of attachment #2 of ExxonMobil's exhibit. We should have 
limited our proposed conditional approval to only method #6A of 
attachment #2.
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    On reviewing the May 4, 2000 submittal and subsequent 
correspondence from the State and ExxonMobil, we believe the revised 
method #6A-1 (previously called method #6A) of attachment #2 is 
acceptable. On March 10, 2000, we submitted comments on the draft 
revision of the method when the State took the rule to public hearing. 
See document #IV.C-30. We wanted assurance that the method would 
measure all sulfide compounds and that no sulfide compounds would be 
lost when collecting and analyzing the sample. The State responded to 
our concern in an April 4, 2000 letter to us (see document #IV.C-33) 
and subsequently forwarded a letter ExxonMobil had sent the MDEQ, dated 
July 25, 2000 (see document #IV.C-37). The April 4, 2000 State letter 
and July 25, 2000 ExxonMobil letter address our concerns.
    We are proposing to approve method #6A-1 of attachment #2 of 
ExxonMobil's exhibit A submitted with the State's May 4, 2000 
submittal, and the attendant compliance monitoring methods, emission 
limitations and facility modifications in sections 3(E)(4) and 4(E) 
(excluding ``or in the flare'' and ``or the flare'' in both sections), 
3(A)(2), and 3(B)(3) of ExxonMobil's exhibit A, submitted on July 29, 
1998.
(3) ExxonMobil's Fuel Gas Combustion Emission Limitations and Attendant 
Compliance Monitoring Method
    In our July 28, 1999 action (64 FR 40803, middle column), we 
proposed to conditionally approve the SIP as it applies to ExxonMobil's 
refinery fuel-gas combustion emission limitations and attendant 
compliance monitoring methods in sections 3(A)(1), 3(B)(2), 4(B), and 
6(B)(3), of ExxonMobil's exhibit A, based on the Governor's commitment 
to address our concerns about the method for monitoring compliance with 
the emission limitation. We had concerns that H2S concentration in the 
refinery fuel gas could exceed the levels which the H2S CEMS was able 
to monitor.
    With the May 4, 2000 submittal, the State did not address our 
concerns regarding the H2S CEMS. On March 10, 2000, we submitted 
comments on the draft SIP revision the State was taking to public 
hearing (see document #IV.C-30). In the public hearing documents, the 
State indicated that it would not be revising ExxonMobil exhibit A to 
address our concerns regarding the H2S CEMS. In our March 10, 2000 
letter we indicated that even though it was rare for ExxonMobil's fuel 
gas H2S concentration to exceed the range of the

[[Page 22244]]

H2S CEMS, we believed that ExxonMobil's exhibit A should be revised to 
address this issue. We suggested that exhibit A could be revised to 
require an alternative method to monitor H2S concentration when the 
range of the CEMS is exceeded, or to provide that any time the range of 
the CEMS is exceeded will be considered a violation of the refinery 
fuel gas emission limitation. In its April 4, 2000 letter to us, the 
State indicated that it believes the ExxonMobil fuel gas monitoring 
method is adequate for compliance monitoring purposes and that it is 
unnecessary and inappropriate to further modify ExxonMobil's monitoring 
requirements (see document #IV.C-33).
    We continue to believe that ExxonMobil exhibit A is not acceptable, 
because the combustion emission limitation is not enforceable under all 
scenarios and thus, does not meet the requirements of section 
110(a)(2)(A) of the Act that the SIP contain enforceable emission 
limitations. Therefore, we believe we cannot propose to fully approve 
the refinery fuel-gas combustion emission limitations and attendant 
compliance monitoring methods in sections 3(A)(1), 3(B)(2), 4(B), and 
6(B)(3) of ExxonMobil's exhibit A.
    However, we do believe it is appropriate to propose limited 
approval and limited disapproval of these provisions. In some cases, a 
SIP rule may contain certain provisions that meet the applicable 
requirements of the Act, but that are inseparable from other provisions 
that do not meet all the requirements. Although the submittal may not 
meet all of the applicable requirements, we may consider whether the 
rule, as a whole, has a strengthening effect on the SIP. If this is the 
case, limited approval may be used to approve a rule that strengthens 
the existing SIP as representing an improvement over what is currently 
in the SIP and as meeting some of the applicable requirements of the 
Act. At the same time we disapprove the rule for not meeting all of the 
applicable requirements of the Act. Under a limited approval/
disapproval action, we approve and disapprove the entire rule even 
though parts of it do and parts do not satisfy requirements under the 
Act. The rule remains a part of the SIP, even though it has been 
limitedly disapproved, because the rule strengthens the SIP. The 
disapproval only concerns the failure of the rule to meet a specific 
requirement of the Act and does not affect incorporation of the rule as 
part of the approved, federally enforceable SIP.
    Therefore, we are proposing to limitedly approve and limitedly 
disapprove sections 3(A)(1), 3(B)(2), 4(B), and 6(B)(3), of 
ExxonMobil's exhibit. We believe emission limitations under sections 
3(A)(1) and 3(B)(2) are enforceable under most but not all scenarios. 
Because the limitations are not enforceable under all scenarios, we 
believe the SIP does not fully satisfy the requirement of section 
110(a)(2)(A) of the Act that the SIP contain enforceable emission 
limitations. We believe limitedly approving these provisions will 
strengthen the SIP. However, we believe the SIP should also be revised 
to address the enforceability concern. As indicated in a separate 
action published today, we intend to propose a FIP to gap-fill those 
provisions of the Billings/Laurel SO2 SIP which are being disapproved. 
We would do the same here. If this proposed limited disapproval becomes 
a final action, we intend to address these concerns in a FIP.
(4) ExxonMobil's Coker CO-Boiler Emission Limitation
    In our July 28, 1999 action (64 FR 40803, first column) we proposed 
to conditionally approve the SIP as it applies to the coker CO-boiler 
stack emission limitation in section 3(B)(1) of ExxonMobil's exhibit A, 
based on the Governor's commitment to adopt a compliance monitoring 
method for the coker CO-boiler stack emission limitation. The July 29, 
1998 SIP submittal did not contain such a method.
    For the May 4, 2000 SIP submittal, the State developed an empirical 
method to monitor compliance with ExxonMobil's coker CO-boiler stack 
emission limitation. The compliance monitoring method is an equation 
that was derived from historical testing and CEMS data, whereby one can 
determine pounds per hour of SO2 emissions from the coker CO-boiler by 
multiplying a constant by the coker fresh feed rate. On March 10, 2000, 
we submitted comments on the draft SIP revision the State was taking to 
public hearing (see document #IV.C-30).
    We had three concerns with the State's empirical method for 
determining compliance with ExxonMobil's coker CO-boiler stack emission 
limitation: (1) The empirical method does not apply, and hence there is 
no compliance monitoring method, when the sulfur content of the reactor 
feed exceeds 5.11 percent of weight. We believe the SIP should contain 
a compliance monitoring method for all operating scenarios. (2) The 
compliance monitoring equation is basically the ``best fit'' line 
through the test data. To be more conservative, we believe the 
compliance monitoring equation should be the upper bound of the 95% 
confidence level of the equation. (3) Finally, since a feed-rate meter 
for the coker unit is required for the compliance monitoring method, 
the feed-rate meter should be subject to QA/QC requirements similar to 
those for the FCC feed-rate meter. Therefore, section 6(E) of 
ExxonMobil exhibit A should be revised to include the fresh feed-rate 
meter for the coker unit, along with the other monitor and meter 
mentioned in that section.
    In its April 4, 2000 letter to us (document #IV.C-33), the MDEQ did 
not agree with our concerns (1) and (2), but did agree with our concern 
in (3). With respect to the concern in (3), MDEQ indicated that it 
would revise the SIP at a later time to address the concern. With 
respect to the concern that the empirical method does not provide a 
compliance monitoring method when the sulfur content of the reactor 
feed exceeds 5.11 percent by weight, our March 10, 2000 letter 
suggested that exhibit A should plan for the situation now. We state 
that exhibit A should indicate that if the sulfur content of the 
reactor feed exceeds 5.11 percent by weight, then the excess sulfur 
over the average sulfur content of the reactor feed from the testing 
results (which is 4.89 percent of weight) shall be assumed to be 
emitted as SO2 from the coker CO-boiler stack. Our letter provided some 
suggested calculations for determining the SO2 emissions from the coker 
CO-boiler when the sulfur content of the reactor feed exceeds 5.11 
percent by weight. In its April 4, 2000 letter, the MDEQ provided 
several reasons why it did not agree with us. First, the MDEQ did not 
believe that the data supported the assumption that all sulfur 
contained in the reactor feed at concentrations above 4.89 percent is 
emitted as SO2. Second, the MDEQ concluded that such an approach would 
do nothing to improve the compliance monitoring method; it would simply 
set an arbitrary limit on the process feed rate. Third, the MDEQ 
believed the empirical method was reliable within the range tested, but 
had not concluded that the empirical method was not reliable outside 
that range. Rather, the MDEQ chose to reserve judgement on the 
empirical method's reliability outside the testing range. Finally, the 
MDEQ believed that the empirical method would be used infrequently. In 
addition, MDEQ questioned the reasons for our suggested calculations 
for determining SO2 emissions from the

[[Page 22245]]

coker CO-boiler when the sulfur content of the reactor feed exceeds 
5.11 percent by weight.
    We still believe that the test method should cover all operating 
scenarios; as currently written, the SIP provides no way to monitor 
compliance with the limit if the sulfur content of the reactor feed 
exceeds 5.11 percent by weight. Because the limitations are not 
enforceable under all scenarios, we believe the SIP does not satisfy 
section 110(a)(2)(A) of the Act. Therefore, there needs to be a method 
to monitor compliance when the sulfur content of the reactor feed 
exceeds 5.11 percent by weight. That method could be similar to the 
approach we suggested in our March 4, 2000 letter, or some other 
acceptable method.
    With respect to the concern regarding the upper bound of the 
equation, we indicated in our March 4, 2000 letter to MDEQ that the 
compliance monitoring equation should be the upper bound of the 95% 
confidence level of the equation, in lieu of the ``best fit'' line 
through the test data. In an April 4, 2000 letter to us, MDEQ indicated 
that it believed the ``best fit'' line was appropriate because the 
coefficient of correlation (r) between the coker fresh feed rate and 
the corresponding SO2 emission is approximately 0.95, and the results 
of the Relative Accuracy (RA) test on the proposed monitoring method 
indicate an RA of 4.9%. An r-value 0.95 is generally considered 
indicative of a very strong relationship. Also, MDEQ believed that 
under our SO2 and NOX CEMS requirements, CEMS performance is considered 
acceptable if the RA tests yield a value of 20% or less.
    We still believe that a conservative approach is necessary to 
assure that the empirical equation will adequately monitor compliance 
and thus assure attainment of the NAAQS. As can be seen in the scatter 
diagram in figure 1 of Tim Schug's August 16, 1999 letter to the MDEQ, 
contained in document # IV.C.-29, there are many points above the 
regression line (the regression line plus a constant is the equation 
used to monitor compliance with the coker CO-boiler emission 
limitation). Therefore, the regression line underestimates the measured 
emissions for these points. Using the 95% confidence interval (or some 
other approvable approach) would assure that the measured emissions for 
all test data points fall below the regression line.
    Because of these three concerns, we cannot propose to fully approve 
the coker CO-boiler stack emission limitation and attendant compliance 
monitoring method in sections 3(B)(1), 2(A)(11)(d) and 4(C) of 
ExxonMobil's exhibit A, submitted on May 4, 2000. However, we believe 
it is appropriate to limitedly approve and limitedly disapprove these 
provisions. See discussion above, in section III.A.3, concerning 
limited approval and limited disapproval of SIPS.
    Therefore, we are proposing to limitedly approve and limitedly 
disapprove sections 2(A)(11)(d), 3(B)(1) and 4(C) of ExxonMobil's 
exhibit A submitted on May 4, 2000. We believe the emission limitations 
under section 3(B)(1) are enforceable under some but not all scenarios. 
Because the emission limitations are not enforceable under all 
scenarios, we believe the SIP does not satisfy section 110(a)(2)(A) of 
the Act. We believe limitedly approving these provisions will 
strengthen the SIP. However, we believe the SIP should also be revised 
to address the concerns mentioned above. As indicated in a separate 
action published today, we intend to propose a FIP to gap-fill those 
provisions of the Billings/Laurel SO2 SIP which are being disapproved. 
We would do the same here. If this proposed limited disapproval becomes 
a final action, we intend to address these concerns in a FIP.
(5) Other Minor Changes to ExxonMobil's Exhibit A
    In the May 4, 2000 submittal, other minor changes were made to 
ExxonMobil's exhibit A. The following sections were added or revised: 
section 3 was revised to add new introductory text; the introductory 
text of sections 3(A) and 3(B) was rewritten to more clearly explain 
how the emission limitations apply; section 3(E)(3) was revised to 
correct a referenced date; and sections 7(B)(1)(j) and 7(C)(1)(1) were 
added and sections 6(B)(7), 7(B)(1)(d), 7(C)(1)(b), 7(C)(1)(d) and 
7(C)(1)(f) were revised because of other changes needed to address the 
coker CO-boiler issue.
    We believe these minor changes are acceptable and are proposing to 
approve these additions and revisions.
(6) Cenex Sour Water Stripper (SWS)
    In our July 28, 1999 action (64 FR 40803, right column) we proposed 
to conditionally approve the SIP as it applies to the combustion source 
emission limitation and the attendant compliance monitoring methods, 
sections 3(B)(2) and 4(D) (only as they apply to the main crude 
heater), 3(A)(1)(d), 4(B), and attachment #2, of Cenex's exhibit A, 
based on the Governor's commitment to revise attachment #2 of the Cenex 
exhibit.\2\ We were concerned that method #6A of attachment #2, which 
contains analytical method used to determine the H2S concentration in 
the sour water, was not acceptable. (The H2S concentration in the sour 
water is needed to monitor compliance with the combustion source 
emission limitation when sour water stripper emissions are being 
combusted in the main crude heater.)
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    \2\ Because we believe the emission limit and compliance 
monitoring method are not separable, in addition to proposing 
conditional approval of the compliance monitoring method in 
attachment #2 of Cenex's exhibit, we also proposed conditional 
approval of the emission limit and other related provisions in 
Cenex's exhibit. Also, we proposed to conditionally approve all of 
attachment #2 of Cenex's exhibit. We should have limited our 
proposed conditional approval to only method #6A of attachment #2 of 
Cenex's exhibit.
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    On reviewing the May 4, 2000 submittal and subsequent 
correspondence from the State and Cenex, we still believe the revised 
method #6A-1 (previously called method #6A) of attachment #2 is not 
acceptable. On March 10, 2000, we submitted comments on the draft 
revision of attachment #2 to Cenex's exhibit A when the State took the 
rule through public hearing. See document #IV.C-30. We wanted assurance 
that the method would measure all sulfide compounds and that no sulfide 
compounds would be lost as a result of collecting and analyzing the 
sample. The State responded to our concern in an April 4, 2000 letter 
to us (see document #IV.C-33) and subsequently followed up with a 
September 5, 2000 telefax containing a letter from Cenex to the MDEQ 
dated August 30, 2000 (see document #IV.C-38). Based on the September 
5, 2000 telefax and August 30, 2000 Cenex letter, it does not appear 
that Cenex's method #6A-1 of attachment #2 will assure that all sulfide 
compounds will be measured.
    Therefore, we believe we cannot propose to fully approve the 
combustion source emission limitation and attendant compliance 
monitoring methods--sections 3(A)(1)(d), 3(B)(2), 4(B), 4(D) and method 
#6A-1 of attachment #2 of the Cenex exhibit. However, we do not believe 
it is appropriate to limitedly approve and limitedly disapprove these 
provisions (excluding ``or in the flare'' and ``in the flare'' in 
sections 3(B)(2) and 4(D)). See discussion above, in section III.A.3, 
concerning limited approval and limited disapproval of SIPS.
    Therefore, we are proposing to limitedly approve and limitedly 
disapprove sections 3(B)(2) and 4(D) (excluding ``or in the flare'' and 
``in the flare'' in both sections), 3(A)(1)(d), 4(B), submitted on July 
29, 1998, and method

[[Page 22246]]

#6A-1 of attachment #2 of the Cenex exhibit A submitted on May 4, 2000. 
We believe the emission limitations under 3(A)(1)(d) are enforceable 
under most but not all scenarios. The emission limitations may not be 
enforceable when sour water stripper overheads are burned in the main 
crude heater. Because the limitations are not enforceable under all 
scenarios, we believe the SIP does not meet section 110(a)(2)(A) of the 
Act. We believe limitedly approving these provisions will strengthen 
the SIP. However, we believe the SIP should also be revised to address 
the enforceability concern. As indicated in a separate action published 
today, we intend to proposed a FIP to gap-fill those provisions of the 
Billings/Laurel SO2 SIP which are being disapproved. We would do the 
same here. If this proposed limited disapproval becomes a final action, 
we intend to address these concerns in a FIP.

B. What Happens When EPA Approves Parts of the State of Montana's Plan?

    One we approve a SIP, or parts of a SIP, the portions approved are 
legally enforceable by us and citizens under the Act.

C. What Happens When EPA Limitedly Approves or Limitedly Disapproves 
Parts of the State of Montana's Plan?

    Once we limitedly approve/disapprove a SIP, or parts of SIP, the 
SIP provisions are legally enforceable by us and citizens under the 
Act. Under a limited approval/disapproval action, we approve and 
disapprove the entire rule even though parts of it do and parts do not 
satisfy requirements under the Act. The rule remains a part of the SIP, 
however, even though there is a disapproval, because the rule 
strengthens the SIP. The disapproval only concerns the failure of the 
rule to meet specific requirements of the Act and does not affect 
incorporation of the rule as part of the approved, federally 
enforceable SIP.

IV. Request for Public Comment

    We are soliciting public comment on all aspects of this proposed 
SIP rulemaking action. Send you comments in duplicate to the address 
listed in the front of this Notice. We will consider your comments in 
deciding our final action if your letter is received before [insert 
date, 30 days from publication].

V. Administrative Requirements

A. Executive Order 12866

    The Office of Management and Budget (OMB) has exempted this 
regulatory action from Executive Order 12866, entitled ``Regulatory 
Planning and Review.''

B. Executive Order 13045

    Protection of Children from Environmental Health Risks and Safety 
Risks (62 FR 19885, April 23, 1997), applies to any rule that: (1) is 
determined to be ``economically significant'' as defined under 
Executive Order 12866, and (2) concerns an environmental health or 
safety risk that EPA has reason to believe may have a disproportionate 
effect on children. If the regulatory action meets both criteria, the 
Agency must evaluate the environmental health or safety effects of the 
planned rule on children, and explain why the planned regulation is 
preferable to other potentially effective and reasonably feasible 
alternatives considered by the Agency.
    This proposed rule is not subject to Executive Order 13045 because 
it does not involve decisions intended to mitigate environmental health 
or safety risks.

C. Executive Order 13132

    Federalism (64 FR 43255, August 10, 1999) revokes and replaces 
Executive Orders 12612 (Federalism) and 12875 (Enhancing the 
Intergovernmental Partnership). Executive Order 13132 requires EPA to 
develop an accountable process to ensure ``meaningful and timely input 
by State and local officials in the development of regulatory policies 
that have federalism implications.'' ``Policies that have federalism 
implications'' is defined in the Executive Order to include regulations 
that 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.'' Under Executive Order 13132, EPA may not issue a 
regulation that has federalism implications, that imposes substantial 
direct compliance costs, and that is not required by statute, unless 
the Federal government provides the funds necessary to pay the direct 
compliance costs incurred by State and local governments, or EPA 
consults with State and local officials early in the process of 
developing the proposed regulation. EPA also may not issue a regulation 
that has federalism implications and that preempts State law unless the 
Agency consults with State and local officials early in the process of 
developing the proposed regulation.
    This proposed rule 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, 
because it merely proposes to partially or limitedly approve and 
limitedly disapprove a state rule implementing a federal standard, and 
does not alter the relationship or the distribution of power and 
responsibilities established in the Clean Air Act. Thus, the 
requirement of section 6 of the Executive Order do not apply to this 
rule.

D. Executive Order 13175

    Executive Order 13175, entitled ``Consultation and Coordination 
with Indian Tribal Governments'' (65 FR 67249, November 6, 2000), 
requires EPA to develop an accountable process to ensure ``meaningful 
and timely input by tribal officials in the development of regulatory 
policies that have tribal implications.''
    This proposed rule does not have tribal implications. It will not 
have substantial direct effects on tribal governments, on the 
relationship between the Federal government and Indian tribes, or on 
the distribution of power and responsibilities between the Federal 
government and Indian tribes, as specified in Executive Order 13175. 
This action does not involve or impose any requirements that affect 
Indian Tribes. Thus, Executive Order 13175 does not apply to this rule.

E. Executive Order 13211

    This proposed rule is not subject to Executive Order 13211, 
``Actions Concerning Regulations That Significantly Affect Energy 
Supply, Distribution, or Use'' (66 FR 28355, May 22, 2001) because it 
is not a significant regulatory action under Executive Order 12866.

F. Regulatory Flexibility

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to conduct a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements unless the agency certifies 
that the rule will 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.
    This proposed partial and limited approval rule will not have a 
significant impact on a substantial number of small entities because 
SIP approvals under section 110 and subchapter I, part D of the Clean 
Air Act do not create any new requirements but simply approve 
requirements that the State is already

[[Page 22247]]

imposing. Moreover, due to the nature of the Federal-State relationship 
under the Clean Air Act, preparation of flexibility analysis would 
constitute Federal inquiry into the economic reasonableness of state 
action. The Clean Air Act forbids EPA to base its actions concerning 
SIPs on such grounds. Union Electric Co., v. U.S. EPA, 427 U.S. 246, 
255-66 (1976); 42 U.S.C. 7410(a)(2).
    Moreover, EPA's proposed limited disapproval rule will not have a 
significant impact on a substantial number of small entities because 
the proposed limited disapproval action only affects two industrial 
sources of air pollution in Billings/Laurel, Montana: Cenex Harvest 
Cooperatives and ExxonMobil Company, USA. Only a limited number of 
sources are impacted by this action. Furthermore, as explained in this 
action, the submission does not meet the requirements of the Clean Air 
Act and EPA cannot approve the submission. The proposed limited 
disapproval will not affect any existing State requirements applicable 
to the entities. Federal disapproval of a State submittal does not 
affect its State enforceability. Therefore, I certify that this action 
will not have a significant economic impact on a substantial number of 
small entities.

G. Unfunded Mandates

    Under sections 202 of the Unfunded Mandates Reform Act of 1995 
(``Unfunded Mandates Act''), signed into law on March 22, 1995, EPA 
must prepared a budgetary impact statement to accompany any proposed or 
final rule that includes a Federal mandate that may result in estimated 
costs to State, local, or tribal governments in the aggregate; or to 
the private sector, of $100 million or more. Under section 205, EPA 
must select the most cost-effective and least burdensome alternative 
that achieves the objectives of the rule and is consistent with 
statutory requirements. Section 203 requires EPA to establish a plan 
for informing and advising any small governments that may be 
significantly or uniquely impacted by the rule.
    EPA has determined that the proposed partial and limited approval 
and limited disapproval actions do not include a Federal mandate that 
may result in estimated costs of $100 million or more to either State, 
local, or tribal governments in the aggregate, or to the private 
sector. This Federal action proposes to partially and limitedly approve 
and limitedly disapprove pre-existing requirements under State or local 
law, and imposes no new requirements. Accordingly, no additional costs 
to State, local, or tribal governments, or to the private sector, 
result from this action.

H. National Technology Transfer and Advancement Act

    Section 12 of the National Technology Transfer and Advancement Act 
(NTTAA) of 1995 requires Federal agencies to evaluate existing 
technical standards when developing a new regulation. To comply with 
NTTAA, EPA must consider and use ``voluntary consensus standards'' 
(VCS) if available and applicable when developing programs and policies 
unless doing so would be inconsistent with applicable law or otherwise 
impractical.
    The EPA believes that VCS are inapplicable to this action. Today's 
action does not require the public to perform activities conducive to 
the use of VCS.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Intergovernmental 
relations, Reporting and recordkeeping requirements, Sulfur oxides.

    Authority: 42 U.S.C. 7401 et seq.

    March 26, 2002.
Jack M. McGraw,
Acting Regional Administrator, Region 8.
[FR Doc. 02-10333 Filed 5-1-02; 8:45 am]
BILLING CODE 6560-50-M