[Federal Register Volume 67, Number 136 (Tuesday, July 16, 2002)]
[Rules and Regulations]
[Pages 46589-46594]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-17235]



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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[IN122-3; FRL-7235-2]


Approval and Promulgation of Implementation Plans; Indiana

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Indiana Department of Environmental Management (IDEM) 
submitted a revised opacity rule to the EPA on October 21, 1999, as a 
requested revision to its State Implementation Plan (SIP). The 
revisions amend portions of Indiana's opacity rule concerning the 
start-up and shutdown of utility boilers, terminology used in 
discussing averaging periods, time periods for temporary exemptions, 
alternative opacity limits, and conflicts between visible emission 
readings and continuous opacity monitor (COM) data. The proposed rule 
and direct final rule were published in the November 30, 2001 Federal 
Register. After EPA received adverse comments, a direct final rule 
withdrawal was published on January 28, 2002. In this action, the EPA 
responds to the adverse comments and takes final action approving 
Indiana's SIP revision request.

DATES: This rule is effective on August 15, 2002.

FOR FURTHER INFORMATION CONTACT: Matt Rau, Environmental Engineer, 
Regulation Development Section, Air Programs Branch (AR-18J), U.S. 
Environmental Protection Agency, Region 5, 77 West Jackson Boulevard, 
Chicago, Illinois 60604, Telephone: (312) 886-6524.

SUPPLEMENTARY INFORMATION: Throughout this document wherever ``we,'' 
``us,'' or ``our'' are used we mean the EPA.

Table of Contents

I. What is EPA approving?
II. What are the changes from the current rules?
    A. Provisions for utility boilers.
    B. Conflicts between COM data and visual opacity readings.
    C. Clarification of averaging periods.
    D. Temporary alternate opacity limitations for non-boiler 
sources.
    E. Opacity limit exemptions for Title V sources.
III. What is EPA's analysis of the supporting materials?
IV. What are the environmental effects of these alternate limits in 
326 IAC 5-1-3?
V. What are EPA's responses to the comments on this SIP revision?
VI. What rulemaking action is the EPA taking?
VII. Administrative Requirements.

I. What Is EPA Approving?

    EPA is approving revisions to Indiana's opacity rule. IDEM 
submitted the revised opacity regulation to the EPA on October 21, 
1999, as a requested revision to its SIP. The revisions address 
applicable requirements concerning the start-up and shutdown of utility 
boilers, the terminology used in discussing averaging periods, time 
periods for temporary exemptions, alternative opacity limits (AOLs), 
and conflicts between visible emission readings and COM data. The 
boiler start-up and shutdown revisions satisfy the Clean Air Act 
requirements and the EPA policy on such provisions. Other rule 
revisions aid the enforcement of the opacity rules.

II. What Are the Changes From the Current Rules?

    The State's submission revises several sections of Indiana's 
opacity rule, 326 IAC Article 5. The revisions involve limited 
exemptions from opacity limits during start-up and shutdown of utility 
boilers equipped with electrostatic precipitators (ESPs), conflicts 
between COM data and visible emission readings, clarification of 
averaging periods, temporary AOLs for non-boiler sources, and 
exemptions for sources with consolidated Title V permit limits.

A. Provisions for Utility Boilers

    The major new component of these revisions allows certain utility 
boilers to obtain limited exemptions from opacity limits during start-
up and shutdown periods in their federally enforceable operating 
permits. The exemption cannot be longer and will generally be shorter 
than an upper bound duration established in the rule, 326 IAC 5-1-3(e). 
This provision is for power plants using coal-fired boilers and ESPs.

B. Conflicts Between COM Data and Visual Opacity Readings

    The current SIP version states that if there is a conflict between 
opacity readings recorded by a COM and those taken by a human observer, 
the COM data will prevail. EPA requested this rule be revised to make 
enforcement easier. Indiana revised the rule, 326 IAC 5-1-4(b), to 
state that data from either a COM or a human observer may be used to 
show a violation of opacity limits. The basis for this change is that 
there are certain instances in which opacity readings from an observer 
may be more accurate than those from a COM. For example, sulfur in a 
high-temperature gas stream exists in a gaseous state inside a 
smokestack and would not register on a COM. Once the gas stream comes 
in contact with the atmosphere, however, chemical reactions and cooling 
occur, causing visible emissions which can be seen by an observer.

C. Clarification of Averaging Periods

    The current version of this rule, 326 IAC 5-1-2, states that the 
limits are not to be exceeded ``in 24 consecutive readings'' with 
readings taken every 15 seconds. The revised rule states that the 
limits are not to be exceeded in ``any one 6-minute averaging period.'' 
The limits themselves are unchanged. Indiana made a similar 
clarification of time averaging periods for temporary AOLs. Under 326 
IAC 5-1-3(a) and (b), Indiana may provide temporary AOLs to certain 
sources for start-up, shutdown, and ash removal. Both of these 
revisions improve the ability to enforce the rule by making it clearer 
and more consistent with the opacity test method. The test method (40 
CFR part 60, appendix A, Method 9) calls for opacity readings to be 
taken by an observer every 15 seconds, and for these readings to be 
averaged on a 6-minute basis.

D. Temporary Alternate Opacity Limitations for Non-Boiler Sources

    New provisions in 326 IAC 5-1-3(c) authorize Indiana to grant 
temporary AOLs to non-boiler sources. These sources now may apply for a 
short-term opacity AOL for start-up, shutdown, and ash removal 
situations. IDEM will submit any temporary AOLs to the EPA as site-
specific SIP revisions. EPA will review them for compliance with Clean 
Air Act requirements and EPA policy. This rule revision does not 
directly affect any SIP emissions limits.

E. Opacity Limit Exemptions for Title V Sources

    Indiana's rule had provided an exemption from opacity limits for 
any source with a specific opacity limit in a Title V permit. The rule, 
326 IAC 5-1-1, allowed sources to consolidate multiple limits into a 
single limit in the Title V permit. This is known as ``streamlining.'' 
The EPA had informed Indiana that the exemption was inappropriate 
because it had impermissibly suggested that Title V permits could 
create SIP exemptions. As a result, Indiana removed the exemption from 
326 IAC 5-1-1.

III. What Is EPA's Analysis of the Supporting Materials?

    The EPA used its September 20, 1999, memorandum entitled ``State 
Implementation Plans: Policy Regarding Excess Emissions During 
Malfunctions, Start-up, and Shutdown'' to evaluate the

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exemptions provisions in 326 IAC 5-1-3(e). To be approved, the 
provisions must meet the seven requirements in this memorandum. The 
requirements are:
    1. The revision must be limited to specific, narrowly-defined 
source categories using specific control strategies;
    2. Use of the control strategy for this source category must be 
technically infeasible during start-up or shutdown periods;
    3. The frequency and duration of operation in startup or shutdown 
mode must be minimized;
    4. As part of its justification of the SIP revision, the state 
should analyze the potential worst-case emissions that could occur 
during start-up and shutdown;
    5. All possible steps must be taken to minimize the impact of 
emissions during start-up and shutdown on ambient air quality;
    6. At all times, the facility must be operated in a manner 
consistent with good practice for minimizing emissions; and
    7. The owner or operator's actions during start-up and shutdown 
periods must be documented by properly signed, concurrent operating 
logs, or other relevant evidence.
    Indiana has met all seven requirements. Language in Indiana's rules 
meets requirements three, five, six, and seven. An October 10, 2001, 
letter from IDEM states that the AOL will only be given to 22 power 
plants using coal-fired boilers with ESPs. This satisfies the first 
requirement. IDEM supplied technical documentation on the infeasibility 
of ESPs during start-up and shutdown to meet requirement two. Indiana 
provided modeling analysis of the potential worst case emissions to 
meet the fourth requirement, as discussed in section IV below.
    In addition to the supporting material for the exemptions in 326 
IAC 5-1-3(e), Indiana provided support for its other opacity revisions. 
Revised language in 326 IAC 5-1-2 clarifies the averaging period for 
opacity level readings. The averaging period is now ``any one (1) six 
(6) minute averaging period.'' The former limit of ``twenty-four (24) 
consecutive readings'' (readings are taken every 15 seconds) was 
revised to aid enforcement of the opacity rules. Indiana also submitted 
revisions to 326 IAC 5-1-3 (a), and (b) which provide sources short-
term temporary AOLs for start-up, shutdown, and ash blowing. An 
alternative 60 percent opacity limit section (a) will now apply for up 
to ``two (2) six (6) minute averaging periods'' in any twenty-four hour 
period. Previously, the limit applied for ``twelve (12) continuous 
minutes.'' Section (b) similarly changes a ``six (6) continuous 
minutes'' to ``one (1) six (6) minute'' averaging period. The 326 IAC 
5-1-3 (a) and (b) revisions also aid rule enforcement.
    Indiana also revised 326 IAC 5-1-3 (c) to include non-boiler 
sources located outside of Lake County with similar AOLs to those of 
326 IAC 5-1-3 (a) and (b). Language in 326 IAC 5-1-1 allowing an 
opacity limits exemption for any source with a specific opacity limit 
in a Title V permit was removed. This exemption was removed because it 
had impermissibly suggested that Title V permits could create SIP 
exemptions.
    Indiana held two public hearings on the opacity rule revisions, 
giving interested parties an opportunity to comment. It held the first 
public hearing on December 3, 1997 and the second on June 3, 1998. 
Transcripts of the public hearing are included in the submittal. 
Representatives from electric utilities, a university, and a cement 
company made comments at the hearings. These comments were generally 
supportive of the rule revisions except for two commenters who 
expressed concern about 326 IAC 5-1-4(b). This section addresses 
conflicts between visual opacity readings and those taken with a COM. 
Indiana further revised this section in response to the comments. 
Section 5-1-4(b) now states that either visual or COM readings may be 
used to support an enforcement action. The source may also use COM 
readings and other relevant information to refute the State's findings.

IV. What Are the Environmental Effects of These Alternate Limits in 326 
IAC 5-1-3?

    Indiana submitted a modeling analysis aimed at assessing the worst-
case impact of the limited exemption from opacity limits in 326 IAC 5-
1-3(e). This modeling analysis addresses the fourth requirement of 
EPA's September 20, 1999 policy. Of the 22 eligible facilities, IDEM 
modeled PSI Energy's power plant in Edwardsport because it has the 
shortest stacks (183 feet) and the most significant impact from 
building downwash. A conservative emissions rate was calculated by 
estimating uncontrolled emissions under full-load operating conditions 
for a conservative eight-hour start-up period. IDEM developed a 
conservative estimate of background concentrations in the area of the 
Edwardsport plant. It showed that application of this background value 
to the other relevant power plants (none of which are in the Lake 
County non-attainment area) would provide a similar degree of 
conservatism.
    Indiana used five years of meteorological data to model estimated 
concentrations of particles of nominal aerodynamic diameter of 10 [mu]m 
or less (PM-10). The Edwardsport modeling results show an ambient PM-10 
concentration (including background) of 98.6 [mu]g/m3, well 
below the 24-hour average PM-10 standard of 150 [mu]g/m3. 
Thus, IDEM has demonstrated that the start-up and shutdown exemption in 
326 IAC 5-1-3 is not expected to cause a violation of the PM-10 air 
quality standards.
    The EPA further examined whether air quality problems could arise 
from multiple sources operating in start-up or shutdown mode 
simultaneously. With one exception, the relevant power plants are 
isolated from each other. The one exception is for two facilities in 
Warrick County. Because the two facilities are about 3 kilometers 
apart, and because these facilities have significantly higher stacks 
than the Edwardsport facility, EPA is satisfied that simultaneous 
operation in start-up or shutdown mode at these two facilities will not 
cause air quality problems. In addition, because operation in start-up 
or shutdown mode (particularly eight hours of such operation) is 
infrequent, simultaneous operation in these modes at more than one 
source is unlikely. Consequently, EPA believes that granting the 
exemption requested by Indiana will not jeopardize continued attainment 
of the air quality standards.

V. What Are EPA's Responses to the Comments on This SIP Revision?

    The Indiana Electric Utility Air Work Group submitted a comment 
supporting the (visual versus monitor) opacity readings revision. EPA 
acknowledges this comment. EPA has also received ten comments on the 
proposed rulemaking for Indiana's opacity rule from a Wyoming citizen. 
The following summarizes the comments and gives the EPA's response:
    Comment 1: EPA should not approve an exemption from Indiana's 
opacity limits because the limits are already quite lax. Sources 
located in non-attainment areas are subject to a 30 percent opacity 
limit (except for facilities located in Lake County which are subject 
to a 20 percent opacity limit), with an exemption allowed for a 
cumulative total of up to fifteen minutes in a 6-hour period during 
which opacity cannot exceed 60 percent, and sources elsewhere are 
subject to a 40 percent opacity limit.
    Response 1: Although the commenter considers Indiana's opacity 
limits lax, in

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fact Indiana has demonstrated to EPA that at least some of these 
sources cannot meet these limits during start-up and shutdown. The 
infeasibility of meeting the limits led Indiana to pursue an exemption 
from its normal opacity limits during these periods in accordance with 
EPA policy. First, the 30 percent opacity limit applies to areas that 
were previously designated non-attainment for total suspended 
particulate matter. Only Lake County is designated non-attainment for 
the current, PM-10 based, particulate matter standard.
    More importantly, the interpretation of the 60 percent opacity 
rules as an ``exemption'' is incorrect. This comment refers to limits 
in 326 IAC 5-1-2(1)(B) and 326 IAC 5-1-2(2)(C) which state that opacity 
shall not exceed 60 percent for a cumulative total of 15 minutes in a 
6-hour period. These 60 percent limits are in addition to the general 
6-minute average opacity limits in 326 IAC 5-1-2 (40 percent, 30 
percent, or 20 percent, depending on the location of the source), and 
are meant to prevent repeated, short-duration high-opacity emissions 
which may not last long enough to cause a violation of a 6-minute 
average opacity limit. There is no language in 326 IAC 5-1-2(1)(B) or 
(2)(C) which exempts sources from other applicable opacity limits. 
Therefore, it would be a violation of the rule if opacity were to 
exceed either the appropriate 6-minute average opacity limit or the 60 
percent 15-minute cumulative limit.
    Comment 2: While 326 IAC 5-1-3(d) does require the submittal of a 
source-specific SIP revision to the EPA for these alternative opacity 
exemptions, EPA's approval of the procedures for alternative opacity 
limits in 326 IAC 5-1-3(d) could be construed as a guaranteed approval 
of the SIP revision as long as the source and the State comply with the 
requirements of this State rule in crafting alternative opacity limits, 
especially considering that Indiana's rule does not require the source-
specific SIP revision to be approved by EPA before the source can be 
exempt from SIP opacity requirements. Thus, this provision must not be 
approved as part of the SIP. Instead, the EPA should simply review and 
approve or disapprove, as appropriate, each source-specific SIP 
revision as submitted.
    Response 2: We disagree with this interpretation of the State rule. 
EPA approval of 326 IAC 5-1-3(d) does not guarantee EPA approval of 
future SIP revisions requesting alternative opacity limits under this 
subsection. 326 IAC 5-1-3(d) merely lays out the conditions and 
procedures under which Indiana would accept such revisions. If such a 
revision is approved by Indiana, the State must submit it to the EPA as 
a site-specific SIP revision. The EPA will review any such submittals 
on their own merits under Clean Air Act requirements and take 
appropriate action.
    Alternative opacity limits under Section 326 IAC 5-1-3(d) do not 
become effective unless and until the EPA approves them as SIP 
revisions. 326 IAC 5-1-7 states that: ``Exemptions given or provisions 
granted by the commissioner in accordance with section * * * 3(d) * * * 
of this rule shall be submitted to the U.S. EPA as a SIP revision and 
shall not become effective until approved as a SIP revision by the U.S. 
EPA.''
    Comment 3: EPA's proposed approval of these revisions is in 
violation of the requirements of the Clean Air Act and EPA's September 
20, 1999 policy. First, it is apparent from the language of 326 IAC 5-
1-3(e) that Indiana has been allowing, without EPA approval, exemptions 
from the SIP's opacity requirements in operating permits (state 
operating permits as well as Part 70 operating permits). Such 
exemptions are illegal, as operating permits cannot allow a source to 
violate the SIP and such permits cannot be used to revise a SIP 
unilaterally. The commenter urges EPA to investigate Indiana's 
implementation of its permitting program to determine if the state is 
allowing illegal revisions to other requirements of the SIP as well as 
the SIP opacity limits through the issuance of operating permits. In 
addition, EPA's approval of the provision without discussion of the 
underlying change in specific SIP requirements is clearly improper.
    Response 3: The 22 facilities eligible for start-up/shutdown 
opacity limit exemptions under 326 IAC 5-1-3(e) currently have opacity 
limit exemptions in their State operating permits. However, since these 
State operating permits are not federally enforceable, they do not 
create SIP exemptions. Indiana cannot issue any Title V permits to 
these 22 facilities which contain start-up/shutdown exemptions until 
326 IAC 5-1-3(e) is incorporated into the SIP by federal rulemaking 
action.
    If EPA approves this provision, the State is bound by the 
provisions in 326 IAC 5-1-3(e) to establish limits which, among other 
things, ``limit the duration and extent of excess emissions to the 
greatest degree practicable,'' and ``minimize the duration and extent 
of excess emissions.'' Indiana has further indicated, in an October 10, 
2001 letter, that it understands that EPA approval of 326 IAC 5-1-3(e) 
will not make the pre-existing opacity exemptions in the State permits 
federally enforceable.
    Comment 4: Indiana's proposed SIP revision does not comply with the 
requirements of EPA's September 20, 1999 policy. EPA's policy states 
that start-ups and shutdowns are part of the normal operation of a 
source and should be accounted for in the planning, design, and 
implementation of operating procedures for the process and control 
equipment. Thus, it is reasonable to expect that careful and prudent 
planning and design will eliminate violations of emissions limitations 
during such periods.
    Response 4: The policy continues: ``For some source categories, 
given the types of control technologies available, there may exist 
short periods of emissions during start-up and shutdown when, despite 
the best efforts regarding planning, design, and operating procedures, 
the otherwise applicable emissions limitation cannot be met.'' The 
policy also states, ``it may be appropriate, in consultation with EPA, 
to create narrowly-tailored SIP revisions that take these technological 
limitations into account and state that the otherwise applicable 
emissions limitations do not apply during narrowly defined start-up and 
shutdown periods.''
    The start-up/shutdown exemptions in 326 IAC 5-1-3(e) only apply to 
coal-fired utility boilers equipped with electrostatic precipitators 
(ESPs). The rule also permits similar exemptions for boilers equipped 
with baghouses at sources with a preexisting permit with such an 
exemption. However, no boilers equipped with baghouses have such a 
permit, so no boilers with baghouses are eligible for the exemption. 
This is a specific source category with a certain type of control 
device that Indiana has determined is technically infeasible to operate 
in low temperature exhaust streams. Thus, approval of this SIP revision 
is appropriate under EPA policy.
    Comment 5: EPA's policy does allow for narrowly-tailored exemptions 
from SIP limits for some source categories, ``given the types of 
control technologies available,'' that cannot meet SIP limits despite 
best efforts regarding planning, design, and operating procedures. 
Regarding this SIP revision, Indiana has claimed those coal-fired 
utility boilers equipped with ESPs cannot meet the existing state 
opacity limits, which already are quite lenient and already allow 
greater levels of opacity during periods of start-up and shutdown. 
Although EPA has stated in its SIP approval that these exemptions only

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apply to coal-fired boilers using ESPs, the State rule does not limit 
the exemption to coal-fired boilers, and it does not limit the 
exemption to facilities using only ESPs for control. In fact, the 
exemptions are even allowed for facilities equipped with baghouses and 
such facilities should have no problems meeting Indiana's lax opacity 
limits, unless such facilities are bypassing the control equipment or 
not maintaining and operating the source in accordance with good air 
pollution practices for minimizing emissions. Thus, the State's rule is 
not limited to specific, narrowly-defined source categories.
    Response 5: 326 IAC 5-1-3(e) states that if a source has different 
start-up and shutdown conditions from those in subsections (a) or (b) 
in a valid operating permit on the effective date of this rule 
(November 8, 1998), the source will be eligible for the 5-1-3(e) start-
up/shutdown exemption. In an October 10, 2001, letter, Indiana states 
that the only facilities having such permits as of November 8, 1998, 
are a group of 22 power plants using coal-fired boilers equipped with 
ESPs. Other sources, such as facilities equipped with baghouses, are 
not eligible for this exemption under the explicit language in 5-1-
3(e). The EPA has determined that coal-fired utility boilers equipped 
with an electrostatic precipitator meet the policy requirement for a 
narrowly-defined source category.
    Comment 6: Indiana did not provide any justification to show that 
the applicable opacity limits cannot be met for sources other than 
coal-fired boilers equipped with ESPs, nor did Indiana provide adequate 
justification to show that the existing opacity requirements could not 
be met, given the types of control technologies available, at coal-
fired boilers equipped with ESPs. Further, the State did not adequately 
show that the use of ESPs during start-up and shutdown was technically 
infeasible.
    Response 6: The start-up/shutdown exemptions apply only to select 
facilities with coal-fired utility boilers controlled with ESPs, so 
there is no need to justify the technical infeasibility for other 
sources. Indiana's October 10, 2001, letter provides technical 
justification from Cinergy, Hoosier Energy, NIPSCO, and Indianapolis 
Power & Light. This technical justification is applicable for all 22 
facilities seeking start-up/shutdown exemptions. Energizing an ESP 
before the flue gas temperature is above the sulfuric acid dew point 
can result in damage to the equipment. Condensation of sulfuric acid in 
the ESP may cause corrosion. It may also condense on the dust in the 
unit causing hard deposits which reduce the PM-10 collection efficiency 
of the ESP. During the ignition of a coal-fired boiler, there is a risk 
of a fire or an explosion if the ESP is energized. Normal sparking can 
ignite any combustible gases in the unit.
    Comment 7: The State must be required to show that its minimum 
criteria for exemptions in 326 IAC 5-1-3(e)(2) will minimize the 
frequency and duration of excess emissions during start-up and shutdown 
to the maximum extent practicable. The State rule does not require the 
facility to, at all times, be operated in a manner consistent with good 
practice for minimizing emissions. The State rule also does not require 
the source to demonstrate that all possible steps were taken to 
minimize the impact of emissions during start-up and shutdown on air 
quality. In addition, the State rule does not require the owner or 
operator's action during start-up and shutdown to be properly 
documented.
    Response 7: In fact, language in the State rule does satisfy the 
September 20, 1999 policy requirement. 326 IAC 5-1-3(e) states that 
each facility must submit ``documentation including, but not limited 
to, historical opacity information during periods of start-up and 
shutdown and other pertinent information and proposed permit conditions 
that limit the duration and extent of excess emissions to the greatest 
practicable extent. The commissioner shall incorporate permit 
conditions that are necessary for safe and proper operation of 
equipment and minimize the duration and extent of excess emissions. 
Such conditions shall require the source to keep records of times of 
start-ups, shutdowns, and ash removals and may be more stringent than 
the operating permit conditions in effect as of the effective date of 
this rule.'' The rule was effective on November 8, 1998. In the October 
10, 2001 letter, Indiana adds, ``we anticipate tightening the allowable 
time periods and requirements for these limitations as we develop the 
Title V permits for these sources, based on historical information 
about emissions during these periods.'' This will further minimize the 
frequency and duration of excess emissions.
    Comment 8: Start-up/shutdown conditions under 326 IAC 5-1-3(e) ``* 
* * appear to be allowed for facilities located in non-attainment 
areas.''
    Response 8: This is not the case. The first sentence of 326 IAC 5-
1-3(e) explicitly states that `` . . . this section applies to sources 
existing on the effective date of this rule located in counties other 
than Lake County.'' As previously stated, the only PM-10 non-attainment 
area in Indiana is located in Lake County.
    Comment 9: The State's modeling analysis does not adequately 
demonstrate that the SIP relaxation will not result in a violation of 
the National Ambient Air Quality Standards (NAAQS). The State claimed 
that this exemption would apply to 22 facilities, but modeled only one 
facility. The State's modeling analysis did not address whether the 
facility modeled had the highest emission rate. The analysis also 
assumed that the topography, meteorological conditions, distance from 
stack to fence line, background concentrations, and locations of other 
nearby sources were identical to the source modeled. The State should 
have modeled every source with an exemption from the SIP opacity limits 
with the specific conditions applicable to each facility to truly 
examine worst case ambient impacts. Thus, this analysis is fatally 
flawed and is not sufficient to demonstrate that the SIP revision won't 
allow for a violation of the NAAQS.
    Response 9: Indiana used a worst-case approach to assess whether 
the exemptions its rules allow would cause violations of the NAAQS near 
any of the eligible facilities. Indiana sought to model a scenario that 
would show impacts equal to or greater than the impacts that would be 
expected at any of the 22 facilities eligible for these exemptions. 
This approach seeks to avoid unnecessary and overly burdensome analyses 
whose results (i.e., attainment) can be deduced from modeling a single 
worst-case scenario. The question, then, is whether Indiana has in fact 
modeled a worst-case scenario.
    A critical element of the modeled scenario is stack height. Indiana 
modeled the facility with the shortest stack of the 22 eligible 
facilities. Indeed, the modeled stack is short enough to have plume 
downwash, which causes much greater impacts than would occur otherwise. 
EPA expects this factor to have more effect on plant impacts than the 
emission differences among these facilities, so that start-up and 
shutdown at the modeled facility should cause higher concentrations 
than they would at the other 21 eligible facilities.
    The commenter identifies several other parameters that can affect 
plant impacts. However, none of these parameters is likely to affect 
plant impacts sufficiently to alter which plant has the worst-case 
impact. Meteorological variations from day to day obviously create 
substantial day to

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day concentration variations, but the question here is whether 
different locations in Indiana could be expected to have significantly 
different ensembles of meteorological conditions. EPA believes that the 
climatology is sufficiently similar across Indiana that an analysis for 
the one location analyzed by the State is sufficient. Distance from 
stack to plant fence line can be important for low-level releases, but 
the peak impacts from the sources involved are generally more than a 
kilometer from the source, i.e., well beyond plant fence line. 
Therefore, differences in fence line distances will likely not affect 
peak concentrations. Terrain can significantly affect concentrations, 
particularly if the terrain rises above the top of the stack. However, 
the stacks of the sources involved are in most cases very tall. They 
are well above both plant grounds and the highest nearby hilltops. EPA 
believes that Indiana has modeled the plant with stacks that are not 
just the shortest but in fact the least elevation above nearby terrain.
    The commenter further expresses concern about variations in 
background concentrations. EPA examined monitoring data throughout the 
State. Sources in Lake County are not eligible for the exemptions at 
issue, and so background concentrations there are not relevant. In the 
rest of the State, the measured background concentrations are 
comparable to the background concentrations that Indiana used. Whereas 
Lake County has a complicated mix of sources, making it difficult to 
assess background concentrations, the rest of the State has fewer 
sources, such that the ``background'' impact of other sources can be 
reasonably represented with available monitoring data. As a result, EPA 
concludes that the addition of the plant impacts modeled by Indiana to 
concentrations elsewhere in the State, other than Lake County, would 
not yield violations of the air quality standards. More generally, EPA 
concludes that Indiana has modeled a worst-case scenario. Indiana's 
modeling showed a 24-hour concentration for this scenario of 98.6 
[mu]g/m3, well below the air quality standard of 150 [mu]g/
m3. EPA therefore concludes that Indiana's modeling suffices 
to demonstrate that the exemptions which Indiana's rule authorizes 
would not allow violations of air quality standards.
    Comment 10: The State has not demonstrated that the SIP relaxation 
will not adversely impact the Prevention of Significant Deterioration 
(PSD) increments.
    Response 10: Under 40 CFR 51.166 (a)(2), a demonstration that a SIP 
revision will not cause or contribute to a violation of the applicable 
PSD increments is required, ``[i]f a State Implementation Plan revision 
would result in increased air quality deterioration over any baseline 
concentration.'' Increment violation can only occur if a source or 
sources increase actual emissions above baseline levels. EPA views the 
emissions associated with start-up and shutdown as emissions that were 
unavoidably present during the baseline period. While SIP relaxations 
ordinary allow an increase in emissions, this SIP revision will not 
yield any increase in emissions above baseline levels and some sources 
will actually require a decrease in emissions. Consequently, this SIP 
revision will not consume any PSD increment and a PSD increment 
consumption analysis is not required.

VI. What Rulemaking Action Is the EPA Taking?

    After considering the comments received, EPA continues to believe 
that Indiana's rule revisions are acceptable, as proposed in the 
November 30, 2001 proposed rule (66 FR 59757). Therefore, the EPA is 
approving revisions to Indiana's opacity rule. The revised regulation 
address provisions concerning the start-up and shutdown of operations, 
terminology used in discussing averaging periods, time periods for 
temporary exemptions, alternative opacity limits, and conflicts between 
visible readings and COM data. This rule will be effective on August 
15, 2002.

VII. Administrative Requirements

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this 
action is not a ``significant regulatory action'' and therefore is not 
subject to review by the Office of Management and Budget. For this 
reason, this action is also not subject to Executive Order 13211, 
``Actions Concerning Regulations That Significantly Affect Energy 
Supply, Distribution, or Use'' (66 FR 28355, May 22, 2001). This action 
merely approves state law as meeting Federal requirements and imposes 
no additional requirements beyond those imposed by state law. 
Accordingly, the Administrator certifies that this rule will not have a 
significant economic impact on a substantial number of small entities 
under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.). Because 
this rule approves pre-existing requirements under state law and does 
not impose any additional enforceable duty beyond that required by 
state law, it does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Public Law 104-4).
    This rule also does not have tribal implications because it will 
not have a substantial direct effect on one or more Indian tribes, 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 by Executive Order 13175 (65 
FR 67249, November 9, 2000). This action also does not have Federalism 
implications because it does 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 (64 
FR 43255, August 10, 1999). This action merely approves 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. This rule also is not subject to Executive Order 13045 
``Protection of Children from Environmental Health Risks and Safety 
Risks'' (62 FR 19885, April 23, 1997), because it is not economically 
significant.
    In reviewing SIP submissions, EPA's role is to approve state 
choices, provided that they meet the criteria of the Clean Air Act. In 
this context, in the absence of a prior existing requirement for the 
State to use voluntary consensus standards (VCS), EPA has no authority 
to disapprove a SIP submission for failure to use VCS. It would thus be 
inconsistent with applicable law for EPA, when it reviews a SIP 
submission, to use VCS in place of a SIP submission that otherwise 
satisfies the provisions of the Clean Air Act. Thus, the requirements 
of section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (15 U.S.C. 272 note) do not apply. This rule does not 
impose an information collection burden under the provisions of the 
Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.).
    The Congressional Review Act, 5 U.S.C. section 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 
rule and other required information to the U.S. Senate, the U.S.

[[Page 46594]]

House of Representatives, and the Comptroller General of the United 
States prior to publication of the 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. section 804(2).
    Under section 307(b)(1) of the Clean Air Act, petitions for 
judicial review of this action must be filed in the United States Court 
of Appeals for the appropriate circuit by September 16, 2002. Filing a 
petition for reconsideration by the Administrator of this final rule 
does not affect the finality of this rule for the purposes of judicial 
review nor does it extend the time within which a petition for judicial 
review may be filed, and shall not postpone the effectiveness of such 
rule or action. This action may not be challenged later in proceedings 
to enforce its requirements. (See section 307(b)(2).)

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, Intergovernmental relations, Particulate matter, Reporting 
and recordkeeping requirements.

    Dated: June 10, 2002.
Bharat Mathur,
Acting Regional Administrator, Region 5.


    For the reasons stated in the preamble, part 52, chapter I, title 
40 of the Code of Federal Regulations is amended as follows:

PART 52--[AMENDED]

    1. The authority citation for part 52 continues to read as follows:

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

Subpart P--Indiana

    2. Section 52.770 is amended by adding paragraph (c)(146) to read 
as follows:


Sec. 52.770  Identification of plan.

* * * * *
    (c) * * *
    (146) On October 21, 1999, Indiana submitted revised state opacity 
regulations. The submittal amends 326 IAC 5-1-1, 5-1-2, 5-1-3, 5-1-
4(b), and 5-1-5(b). The revisions address provisions concerning the 
startup and shutdown of operations, averaging period terminology, 
temporary exemptions, alternative opacity limits, and conflicts between 
continuous opacity monitor and visual readings.
    (i) Incorporation by reference. Opacity limits for Indiana 
contained in Indiana Administrative Code Title 326: Air Pollution 
Control Board, Article 5: Opacity Regulations. Filed with the Secretary 
of State on October 9, 1998 and effective on November 8, 1998. 
Published in 22 Indiana Register 426 on November 1, 1998.
    (ii) Additional material. Letter of October 10, 2001, from Janet 
McCabe, Indiana Department of Environmental Management, Assistant 
Commissioner of the Office of Air Quality, to Stephen Rothblatt, US EPA 
Region 5, Chief of Air Programs Branch. The letter adds the technical 
justification and air quality analysis required for alternate opacity 
limits.

[FR Doc. 02-17235 Filed 7-15-02; 8:45 am]
BILLING CODE 6560-50-P