Approval and Promulgation of Implementation Plans; Minnesota

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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