[Federal Register Volume 62, Number 158 (Friday, August 15, 1997)]
[Proposed Rules]
[Pages 43681-43683]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-21696]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[IA 031-1031; FRL-5875-5]


Approval and Promulgation of Implementation Plans; State of Iowa

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The EPA is proposing to approve the State Implementation Plan 
(SIP) submitted by the state of Iowa to achieve attainment of the 
primary National Ambient Air Quality Standard (NAAQS) for sulfur 
dioxide (SO2) for Muscatine County, Iowa. The SIP was 
submitted to satisfy the requirements of section 110 and part D of 
title I of the Clean Air Act (Act), and regulates certain sources of 
SO2 emissions in Muscatine, Iowa. The effect of the EPA's 
proposed action is to make this revision to the Iowa SIP federally 
enforceable.

DATES: Comments must be received on or before September 15, 1997.

ADDRESSES: Comments may be mailed to Wayne Kaiser, Environmental 
Protection Agency, Air Planning and Development Branch, 726 Minnesota 
Avenue, Kansas City, Kansas 66101.

FOR FURTHER INFORMATION CONTACT: Wayne Kaiser at (913) 551-7603.

SUPPLEMENTARY INFORMATION:

I. Background

    On March 10, 1994, the EPA published a document in the Federal 
Register (59 FR 11193) designating a portion of Muscatine County, Iowa, 
nonattainment for SO2. Additional information on the events 
leading to nonattainment designation are contained in the Technical 
Support Document (TSD) which accompanied that document.
    Areas designated nonattainment are subject to section 110 and part 
D of title I of the Act. On June 13, 1996, and April 25, 1997, the 
state of Iowa submitted information satisfying these requirements. An 
evaluation of the adequacy of this submittal with the Federal 
requirements is discussed below.

II. Description and Analysis of State Submittal

    In 1991 and 1992 there were violations of the primary 
SO2 NAAQS at one of three state air monitors in Muscatine, 
Iowa. This resulted in designation of a portion of Muscatine County as 
nonattainment in 1994. The state determined that there were two major 
emission sources contributing to the violations of the NAAQS. They were 
Grain Processing Corporation (GPC), a wet grain milling facility, and 
Muscatine Power and Water (MPW), a municipal power plant. In the course 
of modeling the impacts of these emission sources, it was also 
determined that a third source, Monsanto Corporation, contributed to a 
modeled violation of the SO2 NAAQS in the vicinity of its 
own facility.
    The state of Iowa's Department of Natural Resources negotiated 
emission reductions with GPC, MPW, and Monsanto. The reductions were 
incorporated into revised construction permits. These permits have been 
submitted as a part of the section 110 SIP revision and thus will be 
federally enforceable when approved by the EPA.
    The normal process for establishing a control strategy for an area 
where a NAAQS violation has occurred is to conduct an air dispersion 
modeling analysis to determine the degree of emissions reductions 
required by the sources contributing to the monitored violations.
    The NAAQS violations occurred at the Musser Park monitor, which is 
located north of and nearest to the GPC facility. Two additional 
monitors, one located further north of the sources, and one located to 
the south near MPW, have never recorded any violations of the NAAQS.
    Dispersion modeling performed by the state using the EPA's 
Industrial Source Complex (ISC) model significantly under predicted 
monitored values at the Musser Park monitor, but was highly accurate at 
the other downwind monitoring site. Consequently, the state initially 
used an alternative methodology, roll-back analysis, to estimate 
emission rates needed to attain the NAAQS at the Musser Park monitoring 
site. A roll-back analysis takes a monitored ambient exceedance 
recorded during a specific set of facility operating conditions and 
determines the amount of the exceedance due to each of the source's 
SO2 emitting operations in use at that time. The estimates 
are then linearly ``rolled back'' to acceptable SO2 emission 
limits which provide for attainment of the NAAQS under that set of 
operating conditions. Ultimately, the state, GPC, and MPW negotiated 
reductions of allowable emissions of 24 percent and 60 percent, 
respectively, and reductions of actual emissions of 4 percent and 13 
percent, respectively. These emission reductions were incorporated into 
revised construction permits for each source. These permits are 
proposed for approval as part of this

[[Page 43682]]

SIP revision and thus will be federally enforceable. The TSD for this 
action contains further information on the modeling analysis and the 
establishment of the final emission limits.
    Although the ISC model was not sufficiently accurate to be the 
basis for the control strategy at GPC and MPW, it was judged to be 
reliable for predicted emissions in the vicinity of the Monsanto 
facility. Modeling here indicated one small area of nonattainment on 
plant property to which the public had access. Monsanto agreed to 
accept emission limits and operating conditions in its permits to 
eliminate the modeled exceedances of the SO2 NAAQS.
    The emission limits imposed upon the sources are contained in the 
following permits:

GPC Permits dated September 18, 1995: #95-A-374; Boilers 1,2,3,5,6,7, 
#74-A-015-S; Source 97, Wet Milling No. 3 Germ Drier, #79-A-194-S; 
Source 15, Wet Milling Nos. 1 and 2 Germ Driers, #79-A-195-S; Source 
126, Wet Milling No. 4 Germ Drier. Permit #95-A-374 contains the 
requirement for the installation of a continuous emission monitor (CEM) 
on the stack servicing the permitted boilers.
MPW Permits dated September 14, 1995: #74-A-175-S; Boiler 7, #95-A-373; 
Boiler 8. Permit #74-A-175 requires the installation of a CEM on boiler 
stack 7. The CEMs provide for continuous measurement of SO2 
emissions and the subsequent determination of compliance with the 
permit emission limits. All permits contain the state's standard 
notification, recordkeeping, and reporting requirements.
Monsanto Permits dated July 18, 1996: #76-A-265-S3; B-6 Boiler, and 
#76-A-161-S3; B-7 Boiler.

III. Nonattainment Plan Provisions (Part D, Section 172(c))

    The following discusses how the submission complies with the 
pertinent provisions of the General Preamble for Implementation of 
title I of the 1990 Amendments and the SO2 Guideliine 
Document, as well as section 172(c) of the Act, which sets forth the 
requirements for part D SO2 SIPs.
    Section 172(c)(1)--In General. The plan complies with the 
requirements to implement reasonably available control measures by 
providing for expeditious attainment of the SO2 NAAQS 
through the emission limits imposed on the sources by enforceable 
permits.
    Section 172(c)(2)--Reasonable Further Progress (RFP). Section 
171(l) of the amended Act defines RFP as ``such annual incremental 
reductions in emissions of the relevant air pollutant as are required 
by (part D) or may reasonable be required by the EPA for the purpose of 
ensuring attainment of the applicable national ambient air quality 
standard by the applicable date.'' As discussed in the General Preamble 
for SO2 (57 FR 13547), there is usually a single ``step'' 
between precontrol nonattainment and postcontrol attainment. Therefore, 
for SO2, with its discernible relationship between emissions 
and air quality and significant and immediate air quality improvement, 
RFP is construed as ``adherence to an ambitious compliance schedule.''
    The state has met the requirement to implement reasonably available 
control measures and RFP by providing for expeditious attainment of the 
SO2 NAAQS through the establishment of emissions limits and 
operating restrictions imposed on the sources by the state construction 
permits submitted as part of the state plan. Implementation plans 
required under section 191(a) shall provide for attainment as 
expeditiously as practicable but no later than five years from the date 
of the nonattainment designation, in this case by March 1999. However, 
the state permits required compliance (and attainment) by March 15, 
1996. The sources met this compliance date, and the EPA believes that 
this date was as expeditious as practicable.
    Section 172(c)(3)--Inventory. This section of the Act requires that 
nonattainment plan provisions include a comprehensive, accurate, 
current inventory of actual emissions from all sources of relevant 
pollutants in the nonattainment area. The emission inventory also 
should include a comprehensive, accurate, and current inventory of 
allowable emissions in the area.
    A detailed emission inventory was included in the states 
submittal. In order to better quantify actual emission from the 100 
``nontraditional'' sources at GPC, source testing was conducted on two 
occasions on a number of representative emission points. In addition to 
the four major sources in the area, an emissions inventory was obtained 
for modeling purposes from three additional minor sources in Muscatine, 
and from 36 sources outside of Muscatine but within 50 kilometers.
    Section 172(c)(5)--Permits for New and Modified Major Stationary 
Sources. Section 172(c)(5) and section 173 of the amended Act contains 
SIP requirements for state construction permitting programs. Any new or 
modified major stationary source constructed in a nonattainment area 
must comply with the state submitted and federally approved New Source 
Review (NSR) Program. The state has an approved NSR program. However, 
revisions were required to make the state rules compliant with the 1990 
Amendments. The state adopted revisions and the EPA approved them in 
Federal Register documents dated June 23, 1995, and October 30, 1995. 
The EPA action proposing approval of the state's emission offset rule 
has been published and a final action is pending.
    Section 172(c)(6)--Other Measures. This section states that SIP 
provisions shall include enforceable emission limitations, and such 
other control measures, means or techniques, as well as schedules and 
timetables for compliance as may be necessary, to provide for 
attainment by the applicable attainment date.
    The state SIP provides for expeditious attainment of the 
SO2 NAAQS through the emission limits and operating 
restrictions that are set forth in the permits issued by the state. The 
emission reductions contained in these documents should ensure that the 
area continues to attain the NAAQS.
    Section 172(c)(7)--Compliance with Section 110(a)(2). This section 
contains general requirements for nonattainment plans. The state has 
met these requirements. The SIP contains enforceable permits which 
ensure attainment of the NAAQS. The state has committed to continue its 
existing ambient monitoring network; it has an approved parts C and D 
permit program (final approval of the state's emission offset rule is 
pending); and it has authority to prevent construction of a source 
which will contribute significantly to nonattainment in, or interfere 
with maintenance by, any other state with respect to the NAAQS. It also 
has demonstrated it has adequate personnel, funding, and authority 
under state law to carry out the provisions of the SIP. With respect to 
section 110(a)(2)(K), under which the EPA generally requires modeling 
in the case of SO2 and other pollutants (to demonstrate 
attainment as required by other provisions of section 110(a) and part 
D), the EPA notes that the ISC model used by the state has been shown 
to under predict ambient SO2 concentrations at the Musser 
Park monitor on known exceedance days. Therefore, as described in more 
detail above, a negotiated reduction of the permitted emission limits 
was established.
    Section 172(c)(8)--Equivalent Techniques. This section provides 
that

[[Page 43683]]

the EPA may allow the state to use equivalent modeling, emission 
inventory, and planning procedures in its SIP unless the EPA determines 
they are less effective than procedures approved by the Administrator. 
Since attainment of the SO2 NAAQS could not be demonstrated 
for all portions of the nonattainment area by modeling (for technical 
reasons described above and in more detail in the TSD), reductions in 
both allowable and actual limits were determined for the affected 
sources based generally on rollback calculations. The EPA believes that 
this procedure is no less effective than other procedures approved by 
the Administrator since it results in enforceable reductions in both 
potential and actual emissions. In addition, although not a basis for 
approval of the attainment demonstration, the EPA notes that no 
monitored violations of the NAAQS have been recorded since the 
reductions have been implemented.
    Section 172(c)(9)--Contingency Measures. For SO2 
programs, the EPA interprets ``contingency measures'' to mean that the 
state agency has a comprehensive program to identify sources of 
violations of the SO2 NAAQS and to undertake an aggressive 
follow-up for compliance and enforcement, including expedited 
procedures for establishing enforceable consent agreements pending 
adoption of revised SIPs.
    The state has a comprehensive program to identify sources of 
violations of the SO2 NAAQS and to undertake an aggressive 
follow-up for compliance and enforcement. The state has statutory 
authority to address any exceedances and resultant violations of the 
NAAQS that may be identified.
    The state will continue to maintain the network of the three 
SO2 ambient air monitoring stations in the nonattainment 
area. The state is committed to quickly identifying when exceedances 
occur and evaluating which sources may be contributing to such 
occurrences. Direct source monitoring, using CEMs as required in the 
permits issued to MPW and GPC under this plan, is designed to ensure 
that the emissions limitations in the permit are not exceeded. 
Reporting requirements established in those permits provide the state 
with a mechanism to consistently monitor the operations of those 
sources.
    Section 176(c)--Conformity. The EPA promulgated final general 
conformity regulations on November 30, 1993. These regulations require 
the states to adopt general conformity provisions in the SIPs for areas 
designated nonattainment or subject to a maintenance plan approved 
under section 175A of the Act. The state submitted its general 
conformity SIP, which the EPA approved on October 25, 1995. The state 
is not subject to the transportation conformity requirements.
    The state complied with the procedural requirements for submittal 
of SIPs pursuant to sections 110(a) and 110(l). The state provided for 
public notice and comment as required. The permits were approved by the 
Iowa Environmental Protection Commission. The SIP and related 
documentation was submitted by the governor's designee to the EPA on 
June 13, 1996, and April 25, 1997.
    The SIP submittal was reviewed by the EPA to determine completeness 
in accordance with the completeness criteria set out in 40 CFR part 51, 
appendix V. The submittal was found complete and the state was so 
notified by an EPA letter dated July 16, 1996.

IV. Proposed Action

    The EPA is proposing to approve a revision to the state SIP which 
incorporates emission restrictions and limitations on major 
SO2 sources in Muscatine, Iowa, for the purpose of assuring 
attainment and maintenance of the SO2 NAAQS. The enforceable 
permit conditions have been in effect since March 15, 1996. There have 
been no exceedances of the NAAQS since September 1995.
    Nothing in this action should be construed as permitting or 
allowing or establishing a precedent for any future request for 
revision to any SIP. Each request for revision to the SIP shall be 
considered separately in light of specific technical, economic, and 
environmental factors, and in relation to relevant statutory and 
regulatory requirements.

V. Administrative Requirements

A. Executive Order 12866

    The Office of Management and Budget has exempted this regulatory 
action from Executive Order 12866 review.

B. Regulatory Flexibility Act

    Under the Regulatory Flexibility Act, 5. U.S.C. 600 et seq., the 
EPA must prepare a regulatory flexibility analysis assessing the impact 
of any proposed or final rule on small entities (5 U.S.C. 603 and 604). 
Alternatively, the EPA may certify that the rule will not have a 
significant impact on a substantial number of small entities. Small 
entities include small businesses, small not-for-profit enterprises, 
and government entities with jurisdiction over populations of less than 
50,000.
    SIP approvals under section 110 and subchapter I, part D of the CAA 
do not create any new requirements but simply approve requirements that 
the state is already imposing. Therefore, because the Federal SIP 
approval does not impose any new requirements, the Administrator 
certifies that it does not have a significant impact on any small 
entities affected. Moreover, due to the nature of the Federal-state 
relationship under the CAA, preparation of a regulatory flexibility 
analysis would constitute Federal inquiry into the economic 
reasonableness of state action. The CAA forbids the EPA to base its 
actions concerning SIPs on such grounds (Union Electric Co. v. U.S. 
E.P.A., 427 U.S. 246, 256-66 (S.Ct. 1976); 42 U.S.C. 7410(a)(2)).

C. Unfunded Mandates

    Under section 202 of the Unfunded Mandates Reform Act of 1995 
(``Unfunded Mandates Act''), signed into law on March 22, 1995, the EPA 
must prepare 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 
private sector, of $100 million or more. Under section 205, the 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 the EPA to establish a 
plan for informing and advising any small governments that may be 
significantly or uniquely impacted by the rule.
    The EPA has determined that the approval action proposed does 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 approves 
preexisting 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.

    Authority: 42 U.S.C. 7401-7671q.

    Dated: July 24, 1997.
William Rice,
Acting Regional Administrator.
[FR Doc. 97-21696 Filed 8-14-97; 8:45 am]
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