[Federal Register Volume 59, Number 170 (Friday, September 2, 1994)]
[Proposed Rules]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-21695]


[[Page Unknown]]

[Federal Register: September 2, 1994]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[MN20-1-5880; FRL-5064-2]

 

Approval and Promulgation of Implementation Plans; Minnesota

AGENCY: Environmental Protection Agency (USEPA).

ACTION: Proposed rule.

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SUMMARY: On December 11, 1992, the Minnesota Pollution Control Agency 
(MPCA) submitted proposed revisions to its State Implementation Plan 
(SIP) for sulfur dioxide (SO2). In the proposed revisions, MPCA is 
attempting to demonstrate attainment and maintenance of the National 
Ambient Air Quality Standards (NAAQS) for SO2 as required by 
Sections 110 and 172 of the Clean Air Act, 42 U.S.C. 7410 and 7502. The 
submittal consists of Administrative Orders representing the St. Paul 
Park/Ashland area of Air Quality Control Region (AQCR) 131. In this 
action, USEPA is proposing to disapprove the State's submittal based on 
enforceability and attainment demonstration concerns. The MPCA must 
address the concerns detailed in this action and submit the 
Administrative Order to USEPA before the end of the 30-day comment 
period. If no other substantive, adverse comments are received and MPCA 
adequately responds the USEPA's concerns before the end of the 30-day 
comment period, USEPA intends to proceed with a direct final approval 
of the submittal. If, however, the concerns are not adequately 
addressed before that time, USEPA will finalize the disapproval. The 
direct final rulemaking would provide an opportunity for the public to 
comment on the final rulemaking action.

DATES: Comments on this requested revision and on the proposed USEPA 
action must be received by October 3, 1994.

ADDRESSES: Copies of the SIP revision request and USEPA's analysis are 
available for inspection at the following address: (It is recommended 
that you telephone Randy Robinson at 312 353-6713, before visiting the 
Region 5 office.) U.S. Environmental Protection Agency, Region 5, Air 
and Radiation Division, 77 West Jackson Boulevard, Chicago, Illinois 
60604.
    Written comments should be sent to: William L. MacDowell, Chief, 
Regulation Development Section, Air Enforcement Branch (AE-17J), U.S. 
Environmental Protection Agency, 77 West Jackson Boulevard, Chicago, 
Illinois 60604.

FOR FURTHER INFORMATION CONTACT: Randy Robinson, Regulation Development 
Section, Air Enforcement Branch (AE-17J), U.S. Environmental Protection 
Agency, Region 5, Chicago, Illinois 60604.

SUPPLEMENTARY INFORMATION:

I. Summary of State Submittal

    On December 11, 1992, the Minnesota Pollution Control Agency (MPCA) 
submitted a revision to the State Implementation Plan (SIP) for sulfur 
dioxide (SO2) in Air Quality Control Region (AQCR) 131 to the 
United States Environmental Protection Agency (USEPA). The seven-county 
metropolitan area (AQCR 131) has been designated, by the USEPA, as 
nonattainment for SO2 (40 C.F.R. 81.324). The submittal is 
intended to demonstrate attainment of the National Ambient Air Quality 
Standards (NAAQS) for SO2 in AQCR 131 for the area surrounding the 
Ashland Petroleum Company. The remainder of the area (Dakota County/
Pine Bend and the rest of the Twin Cities) is being addressed in 
separate rulemakings.

Background

    The USEPA published the designation of AQCR 131 as a primary 
nonattainment area for SO2 on March 3, 1978 (43 FR 8962). The MPCA 
submitted a final SO2 plan on August 4, 1980. USEPA published its 
final rule approving and promulgating the Minnesota Part D SIP for 
SO2 for AQCR 131 on April 8, 1981 (46 FR 20997). The MPCA 
submitted a request for redesignation to attainment of AQCR 131, except 
for the Pine Bend area of Dakota County, on September 2, 1983. The 
redesignation request included permits for several facilities, as well 
as, monitoring data and dispersion modeling intended to support the 
request.
    The USEPA requested several revisions to the permits and compliance 
data included in the 1983 submittal. In addition, the Stack Height Rule 
promulgated on July 8, 1985, required the State to review all existing 
emission limitations to determine whether any of these limitations had 
been affected by stack height credit above Good Engineering Practice 
(GEP) stack height or by other dispersion techniques. As a result of 
this review, MPCA determined that Ashland Petroleum Company (in 
addition to NSP-Riverside, and Koch Refining Company-Pine Bend) would 
require additional permit revisions due to modeled violations using the 
reduced creditable stack heights.
    Given the numerous changes which had occurred since the original 
redesignation request was submitted in 1983, the submittal was 
withdrawn by the MPCA. A new SIP revision for Ashland Refining Company 
was submitted on June 30, 1987. A SIP revision and redesignation 
request for the remainder of AQCR 131, excluding the Pine Bend area of 
Dakota County, was submitted by the MPCA on September 10, 1987. The 
MPCA later withdrew the June 30, 1987, SIP revision because Ashland 
Refining Company could not meet one of the emission limits listed in 
the permit.
    On December 11, 1992, the MPCA submitted a SIP revision for 
SO2 for the St. Paul Park/Ashland area of AQCR 131. The submittal 
includes an Administrative Order for Ashland Petroleum Company--St. 
Paul Park Refinery, in addition to dispersion modeling and technical 
support intended to show that the limits in the Administrative Order 
are sufficient to attain the NAAQS for SO2 in the AQCR 131 
nonattainment area near Ashland Petroleum Company.

II. Attainment Demonstration Review

    This section will provide a general description of the State 
submittal followed by USEPA's review of the attainment demonstration, 
including modeling specifics of the Administrative Order for the 
Ashland Petroleum Company. A more detailed description of the 
Administrative Order and the attainment demonstration is included in 
the technical support document associated with this action.

Description of State Emission Inventory

    The emission units at the Ashland Refining Company--St. Paul Park 
facility that discharge sulfur dioxide to the atmosphere are: three 
process steam boilers, 27 process heaters, one fluidized catalytic 
cracker regenerator, two sulfur recovery units with a common Shell 
Claus Offgas Treatment (SCOT) tailgas unit, two diesel generators and 
heater decoking operations. Specific emission limits and operating 
limits are listed in the administrative order for these sources. In 
addition, sulfur control limits are applied to the diesel fuel and 
hydrogen sulfide limits are applied to the refinery gas. Compliance 
with the emission limitations and operating restrictions shall be 
demonstrated through the combined use of continuous emission monitors 
(CEMS) designed to measure SO2 emissions, continuous monitoring 
systems (CMS) that record fuel flowrate, and hydrogen sulfide content, 
and regular fuel analysis and supplier certification to determine the 
sulfur content and heating value of the fuel oil and diesel fuel. A 
stack test will be used to determine initial compliance at Emission 
Point 15 (SRU's and SCOT, and boilers 4 & 6). It has been determined, 
based on guidance in the ``General Preamble for Future Proposed 
Rulemakings,'' published in the Federal Register on April 16, 1992 (57 
FR 13498), that the compliance methods listed above provide for 
continuous compliance monitoring.

Description of State General Modeling Methodology

    The modeling techniques used in the demonstration are based on the 
modeling guidelines in place at the time the analyses were performed 
(i.e., ``Guideline on Air Quality Models, (Revised),'' July 1986, 
including ``Supplement A,'' July 1987).

Model

    The dispersion modeling conducted for this demonstration was 
performed using the Industrial Source Complex Short-Term (ISCST) model 
(version 90346) for calculation of the 24-hour, 3-hour, and annual 
concentrations. The model was run using the regulatory default option 
and urban mode 3 (McElroy-Pooler) dispersion coefficients. Although a 
land use analysis around Ashland Refining Company would classify the 
area as rural, urban dispersion coefficients were applied based on the 
results of a preliminary model/monitor comparison study which indicated 
that the available rural models underpredict ambient concentrations. To 
assure attainment, MPCA found it necessary to apply the more 
conservative urban dispersion coefficients. The State did not use the 
most recent version of the Industrial Source Complex model, known as 
ISC2. The MPCA had completed the modeling to determine appropriate SIP 
limits before the ISC2 model was released. Therefore, based on USEPA 
guidance concerning grandfathering in the January 2, 1985, memorandum 
from Joseph A. Tikvart, Chief, Source Receptor Analysis Branch, to the 
Regional Modeling Contacts, the use of the ISCS2 version 90346 model is 
acceptable for this particular submittal. Future modeling of the AQCR 
131 area will need to be conducted using the ISC2 model.
Meteorological Data

    The analysis used 1 year of on-site meteorological data (1988). As 
a comparison, the MPCA conducted supplemental modeling using 1973-1977 
Minneapolis Airport surface meteorological data, and St. Cloud mixing 
height data. The results showed that the on-site meteorological data 
resulted in higher predicted 3-hour and 24-hour concentrations. 
However, both data sets produced concentrations demonstrating modeled 
attainment of the SO2 NAAQS. Background concentrations of SO2 
from sources not included in the modeling inventory were determined 
based on consideration of previous background values. Historic 
monitoring data (1984) was considered in ascertaining the SO2 
unmodeled background concentration. The modeling inventory also 
included many minor sources whose collective contributions were 
classified in the submittal as ``background.'' These modeled 
``background'' values, along with the monitored values, were included 
in the critical concentrations identified in the attainment 
demonstration.

Receptor Grid

    The sulfur impacts were calculated over a 4-kilometer by 4-
kilometer area with 100 meter resolution. Terrain effects were 
considered. Complex terrain impacts were determined by using the 
COMPLEX1 model run in the VALLEY mode. The predicted 24-hour 
concentrations for the complex run was less than the ISCST simple 
terrain run; therefore, ISCST results were used for establishing the 
SO2 emission limits in Ashland's Administrative Order.

GEP Determinations

    All Ashland Refinery stacks were modeled using the lesser of the 
actual stack height or 65 meters. Building downwash was not 
incorporated in the original attainment demonstration because MPCA 
maintained the stack heights at the facility were sufficiently high to 
avoid downwash. The USEPA requested, and received from the State, 
documentation demonstrating that the significant sources at the 
facility were not subject to building downwash.

Interstate Impacts

    Section 110(a)(2) of the Clean Air Act requires that the Minnesota 
SIP prohibit emissions which would prevent attainment or maintenance of 
the NAAQS in any other State. The Wisconsin border is approximately 40 
kilometers (km) to the east of the sources included in this attainment 
demonstration. For each source which was explicitly modeled in this 
submittal, attainment in the adjacent State was demonstrated through 
supplemental dispersion modeling. This modeling showed either 
decreasing or steady concentration gradients in the direction of the 
adjacent State and demonstrated that SO2 emissions allowed in 
Minnesota would not prevent attainment or maintenance of the National 
Ambient Air Quality Standards (NAAQS) in Wisconsin.

Comments

    The USEPA has identified deficiencies in the Ashland Petroleum 
Company Administrative Order that the MPCA must adequately address 
before the USEPA can proceed with a final approval. The deficiencies 
are presented in the following comments.
    (1) On page 6, under the definition of 24-hour average, the word 
``quality'' must be replaced by the word ``quantity.''
    (2) On page 9, Section I.C.2. states that ``the company is allowed 
to conduct decoking operations at each process heater not more than 72 
hours in each calendar quarter.'' However, the modeling demonstration 
appears to have based the decoking emissions on operations restricted 
to 72 hours per year. The restriction in the order must reflect the 
same operating hours as the attainment demonstration (72 hours per 
year).
    (3) On page 10, Section I.C.4.a.2. limits the amount of hydrogen 
sulfide in the refinery gas to no more than 162 ppm as an average for 
any consecutive 3-hour period. In the order, this limit does not apply 
during ``periods of startup, shutdown, breakdown, maintenance and 
repair of the fuel gas amine system, SRU1, SRU2, the tailgas recovery 
unit (SCOT), the heavy distillate hydrotreater, and significant 
decreases in hydrogen production.'' The emissions used in the modeled 
attainment demonstration for the refinery gas sources appear to be 
based on the hydrogen sulfide limit on the refinery gas. Allowing 
exemptions to the hydrogen sulfide limit during the time periods 
mentioned above may jeopardize the SO2 standards.
    The ``Guideline on Air Quality Models (Revised), including 
Supplement A,'' dated June 1987, allows exclusion of emissions due to 
malfunctions from the modeling demonstration. The non-malfunction 
related time periods either must be removed from paragraph I.C.4.a.2. 
or it must be shown that the SO2 standards are not violated during 
these periods.
    (4) On page 28, Section VI.D., the order states that ``no facility 
shall be permitted to operate if it experiences an unreasonable 
breakdown frequency of control equipment.'' This provision is 
unenforceable and must be removed.
    (5) On page 29, Section VI.G., references to more stringent 
requirements must be removed. The final sentence should read ``To the 
extent that any Federal or State statute, rule, permit, order, 
stipulation agreement, consent decree or schedule of compliance now in 
force or subsequently issued imposes limits and requires actions 
additional to those required in this Order, the Company shall comply 
with the additional requirements of the Federal or State statute, rule, 
permit, order, stipulation agreement, consent decree, or schedule of 
compliance.''
    (6) A recent USEPA enforcement inspection of the facility showed 
that a bypass route is available for emissions from the sulfur 
reduction units 1 and 2. When the bypass is utilized, emissions do not 
go through the tail gas unit or the incinerator and are not monitored. 
There is no information in the order or the technical support which 
discusses potential emissions, the reason for bypass, or frequency of 
use of this bypass route. It is reasonable to expect that the short-
term SO2 National Ambient Air Quality Standard (NAAQS) may be in 
jeopardy during bypass operations. Information must be provided which 
demonstrates that the SO2 NAAQS are not violated when using the 
bypass associated with the sulfur reduction units. The information must 
include why bypass routes are used, the frequency of use, and the 
associated sulfur emissions. In addition, bypass information must be 
included in the notification requirements listed under Section V.C.
    (7) In Exhibit 2, Section E.1., should be entitled ``Sources not 
subject to New Source Performance Standards.'' Also, in Section 
E.1.a.1. and 2, should state the testing capacity may be ``specified by 
the MPCA and/or USEPA.''
    Further comments are documented in the Technical Support Document 
(TSD), dated March 18, 1994.

Section 172 Requirements

    Air Quality Control Region 131 is designated as a nonattainment 
area for the primary NAAQS for sulfur dioxide. As a result, sulfur 
dioxide nonattainment area plans must meet the requirements of Subpart 
I of Part D of Subchapter I of the Clean Air Act, particularly Section 
172(c). Guidance on the requirements of Section 172 is given in the 
General Preamble for the Implementation of Title I of the Clean Air Act 
Amendments of 1990; Proposed Rule; published April 16, 1992 at 57 FR 
13498.
    Section 172(c)(1) states that plans must require reasonably 
available control measures (RACT). The General Preamble states that 
``the definition of RACT for SO2 is that control technology which 
is necessary to achieve the NAAQS.'' Minnesota's submittal includes air 
dispersion modeling designed to show that, when the comments are 
adequately addressed, the area will achieve attainment of the SO2 
NAAQS with the control measures fully implemented, and therefore 
satisfy the RACT requirement of Section 172(c)(1).
    Section 172(c)(2) states that plans shall require reasonable 
further progress. The term ``reasonable further progress'' is defined 
in Section 171(1) as ``such annual incremental reductions in emissions 
of the relevant air pollutant as are required by this part or may 
reasonably be required by the Administrator for the purpose of ensuring 
attainment of the applicable NAAQS by the applicable date.'' These 
measures are not applicable because the Administrative Order ensures 
attainment of the SO2 NAAQS by February 1994.
    Section 172(c)(3) requires a suitable emission inventory. A 
suitable inventory of SO2 emissions was included in the submittal.
    Section 172(c)(4) mandates that any stationary source growth margin 
included in the SIP must be expressly identified and quantified. Zero 
growth margin was provided for in the submittal.
    Section 172(c)(5) mandates a suitable permit program for new and 
modified major stationary sources. A new source permitting program for 
nonattainment areas was approved on April 28, 1994 (59 FR 21939).
    Section 172(c)(6) requires enforceable limitations sufficient to 
provide for attainment. The Administrative Order provides emission 
limitations, operating requirements, and compliance schedules. When the 
concerns identified previously in this action are adequately addressed, 
the plan will then demonstrate, through air dispersion modeling, that 
the fully implemented control measures achieve attainment of the 
SO2 NAAQS.
    Section 172(c)(7) mandates satisfaction of Section 110(a)(2). 
Principal among the requirements of Section 110(a)(2) are requirements 
that the State adopt its limitations following a suitable opportunity 
for public comment. The MPCA Commissioner has certified that the public 
hearing was noticed on November 9, 1992, and was held on December 15, 
1992. Section 172(c)(8) states that the Administrator, in some 
circumstances, may allow the use of equivalent modeling emission 
inventory, and planning procedures. MPCA did not seek this 
authorization.
    Section 172(c)(9) requires the plan to provide for implementation 
of specific measures to be undertaken if the area fails to make 
reasonable further progress (i.e., contingency measures), or to attain 
the primary NAAQS by the attainment date applicable under this part. 
The General Preamble, referenced above, provides guidance on SIP 
requirements for SO2 nonattainment areas. It discusses contingency 
measures for SO2 and states that it is unlikely for an area to 
implement SO2 controls and fail to attain the NAAQS. Therefore, 
USEPA interprets ``contingency measures'' for SO2 to include the 
ability to rely on comprehensive State programs to identify violations 
and to provide for compliance and enforcement. Minnesota Stat. 
Sec. 115.071 provides that the provisions issued by the MPCA may be 
enforced by various means. The orders also contain reporting 
requirements necessary to determine compliance. Given this information, 
it has been determined that the submittal contains appropriate 
contingency measures.

III. Proposed Rulemaking Action

    The USEPA is proposing to disapprove the Minnesota SIP revision for 
SO2 for the St. Paul Park/Ashland area of AQCR 131. However, if 
the above comments, detailed in this action, are adequately addressed 
in revisions to this plan, and those revisions are submitted to USEPA 
by the end of the 30-day comment period, then, assuming no other 
substantive adverse public comments are received, USEPA intends to 
publish a direct final rulemaking approving the SIP revision as a whole 
including the supplemental submittal. If, at the end of the 30-day 
comment period, the issues are still unresolved, final rulemaking 
disapproving the SIP revision will be promulgated.
    Public comments are solicited on the requested SIP revision and on 
USEPA's proposal to disapprove. Public comments received by October 3, 
1994 will be considered in the development of USEPA's final rulemaking 
action.
    Nothing in this action should be construed as permitting, allowing 
or establishing a precedent for any future request for revision to any 
SIP. USEPA shall consider each request for revision to the SIP in light 
of specific technical, economic, and environmental factors, and in 
relation to relevant statutory and regulatory requirements.
    This action has been classified as a Table 2 action by the Regional 
Administrator under the procedures published in the Federal Register on 
January 19, 1989 (54 FR 2214-2225). A revision to the SIP processing 
review tables was approved by the Acting Administrator for the Office 
of Air and Radiation on October 4, 1993 (Michael Shapiro's memorandum 
to Regional Administrators). A future notice will inform the general 
public of these tables. Under the revised tables, this action remains 
classified as Table 2. The Office of Management and Budget has exempted 
this regulatory action from Executive Order 12866 review.
    Under the Regulatory Flexibility Act, 5 U.S.C. 600 et seq., USEPA 
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, USEPA 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.
    USEPA's disapproval of the State request under Section 110 and 
Subchapter I, Part D of the CAA does not affect any existing 
requirements applicable to small entities. Any pre-existing Federal 
requirements remaining in place after this disapproval. Federal 
disapproval of the State submittal does not affect its state 
enforceability. Moreover, USEPA's disapproval action does not have a 
significant impact on a substantial number of small entities because it 
does not remove existing requirements nor does it impose any new 
Federal requirements.

List of Subjects in 40 CFR Part 52

    Air Pollution Control, Environmental protection, Incorporation by 
Reference, Reporting and record keeping requirements, Sulfur dioxide.

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

    Dated: August 22, 1994.
Valdas V. Adamkus,
Regional Administrator.
[FR Doc. 94-21695 Filed 9-1-94; 8:45 am]
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