Approval and Promulgation of Air Quality Implementation Plans; Montana; State Implementation Plan for East Helena SOINF2 Nonattainment Area

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[MT23-1-6402a; FRL-5128-1]

Approval and Promulgation of Air Quality Implementation Plans;

Montana; State Implementation Plan for East Helena SO2

Nonattainment Area

AGENCY: Environmental Protection Agency (EPA).

ACTION: Direct final rule.

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SUMMARY: EPA fully approves the State implementation plan (SIP)

submitted by the State of Montana to achieve attainment of the primary

National Ambient Air Quality Standards (NAAQS) for sulfur dioxide

(SO2). The SIP was submitted by Montana to satisfy certain federal

requirements for an approvable nonattainment area SO2 SIP for East

Helena. The effect of EPA's final action is to make the East Helena

Primary SO2 NAAQS SIP federally enforceable.

DATES: This final rule is effective March 28, 1995, unless adverse

comments are received by February 27, 1995. If the effective date is

delayed, timely notice will be published in the Federal Register.

ADDRESSES: Comments should be addressed to Meredith A. Bond, 8ART-AP,

Environmental Protection Agency, Region VIII, 999 18th Street, Suite

500, Denver, Colorado 80202-2405. Copies of the State's submittal and

other information are available for inspection during normal business

hours at the following locations: Air Programs Branch, Environmental

Protection Agency, Region VIII, 999 18th Street, Suite 500, Denver,

Colorado 80202-2405; and Montana Department of Health and Environmental

Sciences, Air Quality Bureau, Cogswell Building, Helena, Montana 59620-

0901; and U.S. EPA Air & Radiation Docket Information Center, 401 M

Street, SW., Washington, DC 20460.

FOR FURTHER INFORMATION CONTACT: Meredith Bond at (303) 293-1764.

SUPPLEMENTARY INFORMATION:

I. Background

East Helena, Montana, is a small community located about 5 miles

east of the State capitol, Helena. The major industrial source

affecting the SO2 concentrations in the ambient air is the Asarco,

Incorporated, primary lead smelter. The following summarizes the

regulatory history of the East Helena SO2 nonattainment area.

On September 19, 1975, EPA approved the revision to the Montana SIP

which sets forth a sulfur oxide control strategy to provide for

attainment and maintenance of the SO2 NAAQS near Asarco in East

Helena (40 FR 43216).

The Clean Air Act Amendments of 1977 provided for non-attainment

designations for areas violating the NAAQS. On March 3, 1978, EPA

designated the East Helena area as nonattainment for SO2 based on

historical ambient monitoring data [[Page 5314]] showing primary

standard violations (43 FR 8962).

Prior to this official SO2 nonattainment designation, the

Montana Department of Health and Environmental Sciences (MDHES) and

Asarco had been working on a plan to reduce SO2 emissions from the

East Helena facility. The main focus of this plan was the construction

of a double contact sulfuric acid plant to control SO2 emissions

from the sintering process. Following construction of the acid plant in

July 1977, SO2 concentrations in the rural areas around East

Helena decreased dramatically. However, there were still violations

being monitored at the Kennedy Park site.

In response to the Part D SIP requirements of the 1977 CAA

Amendments, on April 24, 1979, Montana submitted a SIP revision for the

East Helena SO2 nonattainment area. This SIP revision identified

the continued monitored violations as being caused by low-level

emissions from three 110-foot stacks serving the smelter's blast

furnace operations. The control strategy included replacing the three

110-foot stacks with a single 425-foot stack (for which Asarco claimed

stack height credit of 375 feet), and setting daily and six-hour

emission limits on the new stack. On November 20, 1980, EPA

conditionally approved the SIP revision (45 FR 76685). EPA's action was

conditioned upon adequate demonstration of good engineering practice

(GEP) stack height for the blast furnace stack, and revised dispersion

modeling if GEP height was determined to be below 375 feet.

Asarco completed a field tracer study demonstration in 1982, and

subsequently proceeded to complete construction of its new stack based

on the study results justifying a stack height of 375 feet as necessary

to overcome the effects of downwash causing monitored ambient SO2

violations near the smelter.

On July 5, 1983, EPA proposed to approve the SIP and GEP

demonstration as satisfying the conditional approval requirements (48

FR 30696). But, final action was not taken due to pending litigation

concerning the federal stack height regulations. As a result of this

litigation, the federal stack height regulations were revised on July

5, 1985. Among other things, these revisions changed the requirements

for justifying stack heights above the formula height established in 40

CFR 51.100(ii)(2). For this reason, several years later Asarco

abandoned its efforts to take credit for the additional blast furnace

stack height above formula height. EPA's stack height analysis and

findings for the Asarco facility stacks are discussed further later in

this document.

The SIP was further revised with respect to East Helena in order to

provide for a catalyst screening procedure at Asarco's acid plant. EPA

approved this revision on May 1, 1984 (54 FR 18482).

The 1990 Clean Air Act Amendments1 (``1990 Amendments''),

effective November 15, 1990, reaffirmed the nonattainment designation

of East Helena with respect to the primary and secondary SO2

NAAQS, under section 107(d)(4)(B). See 56 FR 56706 (Nov. 6, 1991) and

40 CFR 81.327 (specifying designation for East Helena). Section 191

required that any state which was lacking an approved SIP for an area

designated nonattainment with respect to the national primary ambient

air quality standard for SO2 must resubmit a plan meeting the

requirements of the amended Act within 18 months of enactment of the

amendments, thus by May 15, 1992. For the secondary SO2 NAAQS SIP

for East Helena, EPA established November 15, 1993, as the submittal

due date in an action published in the Federal Register on October 7,

1993 (58 FR 52237).

\1\The 1990 Amendments to the Clean Air Act made significant

changes to the Act. See Public Law No. 101-549, 104 Stat. 2399.

References herein are to the Clean Air Act, as amended (``the

Act''). The Clean Air Act is codified, as amended, in the U.S. Code

at 42 U.S.C. Sections 7401, et seq.

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The air quality planning requirements for SO2 nonattainment

areas are set out in subparts 1 and 5 of part D of title I of the

Act.2 The amended Clean Air Act requires nonattainment area SIP

submittals to contain, among other things, provisions to assure that

reasonable available control measures (including such reductions in

emissions from existing sources in the area as may be obtained through

the adoption, at a minimum, of reasonably available control technology)

are implemented, and that provide for attainment of the primary

SO2 standards within 5 years of enactment of the 1990 Amendments,

or November 15, 1995 (see Sections 172(c) and 192(b) of the Act). EPA

has issued detailed guidance that describes the Agency's preliminary

interpretations regarding SO2 nonattainment area SIP requirements.

[57 FR 13498 (April 16, 1992) and 57 FR 18070 (April 28, 1992)

(hereafter called the ``General Preamble'')]. Because EPA is describing

its interpretations here only in broad terms, the reader should refer

to the General Preamble for a more detailed discussion of the

interpretations of title I advanced in today's action and the

supporting rationale.

\2\Subpart 1 contains provisions applicable to nonattainment

areas generally and subpart 4 contains provisions specifically

applicable to PM10 nonattainment areas. At times, subpart 1 and

subpart 4 overlap or conflict. EPA has attempted to clarify the

relationship among these provisions in the ``General Preamble'' and,

as appropriate, in today's notice and supporting information.

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II. This Action

The primary SO2 NAAQS SIP for East Helena was developed by the

MDHES in consultation with Asarco, the major SO2 source in East

Helena. The State's efforts have been coordinated with EPA to ensure

compliance with SIP requirements. The Montana Board of Health and

Environmental Sciences (MBHES) approved a stipulation between the MDHES

and Asarco on March 18, 1994, to limit SO2 emissions from that

company's lead smelting operations. This binding agreement was

submitted to EPA on March 30, 1994, as part of a revision of the

Montana SIP. This SIP revision addresses only the 24-hour and annual

primary SO2 NAAQS; Montana will address the 3-hour secondary

SO2 NAAQS in a forthcoming submittal. Hence, this action addresses

only the primary SO2 NAAQS.

Section 110(k) of the Act sets out provisions governing EPA's

review of SIP submittals (see 57 FR 13565-66). In this action, EPA is

approving the primary SO2 NAAQS SIP revision for the East Helena,

Montana, nonattainment area which was due on May 15, 1992, and was

submitted by the Governor of Montana on March 30, 1994. EPA is also

approving the stack height demonstrations for the Asarco, East Helena,

primary lead smelter. EPA believes that the East Helena plan meets the

applicable requirements of the Act.

Since the East Helena Primary SO2 NAAQS SIP was not submitted

by May 15, 1992, as required by section 191 of the Act, EPA made a

finding that the State failed to submit the SIP, pursuant to section

179 of the Act, and notified the Governor in a letter dated June 16,

1992. See 57 FR 48614 (October 27, 1992). After the East Helena Primary

SO2 NAAQS SIP was submitted on March 30, 1994, EPA found the

submittal complete pursuant to section 110(k)(1) of the Act and

notified the Governor accordingly in a letter dated May 12, 1994. This

completeness determination corrected the State's deficiency and,

therefore, terminated the sanctions clock under section 179 of the Act.

A. Analysis of State Submission

1. Procedural Background

The Act requires States to observe certain procedural requirements

in [[Page 5315]] developing implementation plans and plan revisions for

submission to EPA. Section 110(a)(2) of the Act provides that each

implementation plan submitted by a State must be adopted after

reasonable notice and public hearing.3 Section 110(1) of the Act

similarly provides that each revision to an implementation plan

submitted by a State under the Act must be adopted by such State after

reasonable notice and public hearing. The EPA also must determine

whether a submittal is complete and therefore warrants further EPA

review and action (see section 110(k)(1) and 57 FR 13565). The EPA's

completeness criteria for SIP submittals are set out at 40 CFR Part 51,

Appendix V. The EPA attempts to make completeness determinations within

60 days of receiving a submission. However, a submittal is deemed

complete by operation of law if a completeness determination is not

made by EPA six months after receipt of the submission.

\3\Also Section 172(c)(7) of the Act requires that plan

provisions for nonattainment areas meet the applicable provisions of

Section 110(a)(2).

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To entertain public comment on the implementation plan for East

Helena, the State of Montana, after providing adequate notice, held a

public hearing on March 18, 1994, to address the stipulation between

the MDHES and Asarco, and the East Helena primary SO2 NAAQS SIP.

Following the public hearing, the stipulation and SIP were adopted by

the State. The Governor of Montana submitted the SIP to EPA on March

30, 1994. The SIP submittal was reviewed by EPA to determine

completeness in accordance with the completeness criteria set out at 40

CFR Part 51, Appendix V. The submittal was found to be complete, and a

letter dated May 12, 1994, was forwarded to the Governor indicating the

completeness of the submittal and the next steps to be taken in the

review process.

2. Accurate Emission Inventory

Section 172(c)(3) 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.

The MDHES identified two major sources of SO2 in the East

Helena area: the Asarco Smelter complex and the Ash Grove cement plant.

Emission inventory information for the Ash Grove Kiln stack was derived

from an engineering calculation to determine potential SO2

emissions. Assuming all heat input to the kiln is supplied by 6% sulfur

coke, a potential emission rate of 2.7 tons SO2/day was used for

this facility in this SIP revision. Actual SO2 emissions for this

source are approximately 1.0 ton per day.

A detailed SO2 emission inventory of the Asarco smelter

facility was conducted in the fall of 1991. A complete testing protocol

was approved by EPA along with the final emission inventory report. The

report provided a complete and accurate SO2 emission inventory of

the entire facility for use in dispersion modeling studies.

In general, the SO2 emission sources were separated into three

major categories: Point sources, volume sources, and fugitive sources.

The results of the point source tests confirmed Asarco's three major

sources of SO2 emissions to be the Sinter Plant Baghouse stack,

Acid Plant stack, and Blast Furnace Baghouse stack. Volume and fugitive

sources were also quantified.

The MDHES also maintains an annual SO2 emission inventory for

the Asarco facility. This inventory does not include all sources that

were measured in the field sampling study, but does include the major

sources of SO2 emissions. Totals for 1990 (including only the

three major point sources) were 17,491.0 tpy; totals for 1991 (with

building volume and fugitive area sources included) were 18,031.7 tpy.

Thus, annual SO2 emissions for the Asarco facility are

approximately 18,000 tpy. For the Ash Grove kiln stacks, emissions for

the same years were less than 280 tpy.

EPA is approving the emissions inventory because it is accurate and

comprehensive and provides a sufficient basis for determining the

adequacy of the attainment demonstration for this area consistent with

the requirements of sections 172(c)(3) and 110(a)(2)(K) of the Act. For

further details see the TSD.

3. RACM (Including RACT)

As noted, the initial SO2 nonattainment areas must submit

provisions to assure that RACM (including RACT) are implemented as

expeditiously as possible (see section 172(c)(1)). The General Preamble

contains a detailed discussion of EPA's interpretation of the RACM

(including RACT) requirement (see 57 FR 13547 and 13560-13561), and

defines RACT for SO2 as that control technology which is necessary

to achieve the NAAQS.

The Asarco, East Helena, primary lead smelter was identified as the

major source of the SO2 nonattainment problem in East Helena. The

control strategy includes setting operational SO2 emission limits

for several of the major emission points of the Asarco facility.

Asarco developed a set of emissions parameters for combined

emissions from the two largest SO2 emission points, the sinter and

blast furnace stacks, in order to provide maximum operating flexibility

while still protecting the NAAQS. The set of compliance parameters for

combined emissions from the Blast Furnace Stack and Sinter Plant Stack

consists of the following relationships:

for:

022.93, B=29.64-(0.180) S

22.9354.54, B=38.74-(0.577) S

54.5460.27, B=76.60-(1.271) S

where:

B=Daily emissions of SO2 from the Blast Furnace Stack in tons per

calendar day

S=Daily emissions of SO2 from the Sinter Plant Stack in tons per

calendar day

In addition to the compliance parameters for combined emissions

from the sinter and blast furnace stacks, the March 18, 1994,

stipulation also sets absolute SO2 emission limitations for the

sinter and blast furnace stacks at 60.27 tons per calendar day and

29.64 tons per calendar day, respectively. Daily emissions of SO2

from the Acid Plant Stack shall not exceed 4.30 tons per calendar day.

SO2 emissions from the Concentrate Storage and Handling Building

Stack (including the exhaust from the new Sinter Plant Ventilation

System baghouse) shall not exceed 46.00 pounds per hour or 0.552 tons

per calendar day. All of these emission limits, including the

compliance parameters for the combined emissions of the sinter and

blast furnace stacks, were effective September 1, 1994.

Two additional emission limitations on minor stack sources at the

Asarco facility take effect June 30, 1995: SO2 emissions from the

Crushing Mill Baghouse Stacks #1 and #2 shall not exceed 0.19 and 0.37

tons per calendar day, respectively.

The stipulation details the use of continuous emission monitoring

systems to determine compliance with the emission limitations for the

sinter plant stack, blast furnace stack, and acid plant stack. Emission

testing provisions for the remaining stacks are also specified.

Provisions have also been incorporated into the stipulation to

insure that sulfur dioxide emissions from miscellaneous volume and

fugitive sources do not increase beyond their current levels. Those

provisions include: limiting fugitive emissions of

[[Page 5316]] SO2 from the Sinter (D&L) Building by restricting

openings to the building enclosure; maintaining and operating all

processes and systems within the Cottrell Penthouse, Mist Precipitator

Building, and Pump Tank Building such that conditions which contribute

to volume source SO2 emissions from these sources are not

significantly worsened compared to conditions existing during the

preparation of the January 20, 1992, emission inventory report; and

maintaining and operating all processes and systems associated with the

Acid Plant Scrubber Towers such that conditions which contribute to

volume source SO2 emissions from this source are not significantly

worsened compared to conditions existing during the preparation of the

January 20, 1992, emission inventory report.

A more detailed discussion of the control strategy can be found in

the TSD for this action. EPA has reviewed the State's documentation and

concluded that it adequately justifies the control measures to be

implemented. The implementation of Montana's SO2 nonattainment

plan will result in the attainment of the primary SO2 NAAQS by

November 15, 1995. By this action EPA is approving the East Helena

primary SO2 plan's RACM (including RACT) in its entirety, noting

that additional dispersion modeling and control strategy evaluation

will be necessary in the future to address the secondary, 3-hour

standard.

4. Demonstration

The initial SO2 nonattainment areas are required to submit a

demonstration (including air quality modeling) showing that the plan

will provide for attainment as expeditiously as practicable, but no

later than November 15, 1995. EPA-approved dispersion models ISCST and

RTDM were used to predict ambient SO2 concentrations around the

Asarco facility. The primary SO2 NAAQS are 365 micrograms per

cubic meter (g/m\3\) (0.14 parts per million (ppm)), averaged

over a 24-hour period and not to be exceeded more than once per year,

and 80 g/m\3\ (0.03 ppm) annual arithmetic mean (see 40 CFR

50.4). The demonstration for East Helena indicates that the primary

SO2 NAAQS will be attained by November 15, 1995. For a more

detailed description of the attainment demonstration and the control

strategies used, see the TSD for this action.

5. Enforceability Issues

All measures and other elements in the SIP must be enforceable by

the State and EPA (see sections 172(c)(6) and 110(a)(2)(A) of the Act

and 57 FR 13556). The EPA criteria addressing the enforceability of

SIPs and SIP revisions were stated in a September 23, 1987, memorandum

(with attachments) from J. Craig Potter, Assistant Administrator for

Air and Radiation, et al. (see 57 FR 13541). Nonattainment area plan

provisions also must contain a program to provide for enforcement of

control measures and other elements in the SIP (see section

110(a)(2)(C) of the Act).

The specific control measure contained in the SIP are addressed

above in section 3, ``RACM (including RACT).'' The March 18, 1994,

stipulation between the MDHES and Asarco has been approved by the MBHES

in accordance with section 75-2-301 of the Montana Clean Air Act and

effectuated by a MBHES order, and since the MDHES can enforce MBHES

orders, the MDHES has independent enforcement powers. The Montana Clean

Air Act grants authority to the MDHES to enforce orders of the Board

(section 75-2-112, Montana Code Annotated (MCA)). Sections 75-2-412 and

75-2-413, MCA, authorize the MDHES to seek criminal and civil penalties

for violations of any Board order in the amount of $10,000.00 per day

of violation, respectively. In addition, Section 75-2-431, MCA,

authorizes the MDHES to seek noncompliance penalties for any violation

of a Board order. Noncompliance penalties shall be no less than the

economic value which a delay in compliance may have for the owner of

such a source, including the capital costs of compliance and debt

service over a normal amortization period (not to exceed ten years of

operation) and maintenance costs foregone as a result of noncompliance.

EPA believes that the State's existing air enforcement program will

be adequate to ensure implementation of this SIP revision. The TSD for

this action contains further information on enforceability

requirements, responsibilities, and resources intended to support

effective implementation of the control measures.

6. Reasonable Further Progress

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 reasonably be required by 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, there is usually a single ``step'' between pre-

control nonattainment and post-control attainment. Therefore, for

SO2, with its discernible relationship between emissions and air

quality and significant and immediate air quality improvements, RFP is

construed as ``adherence to an ambitious compliance schedule.''

Asarco became responsible for the reporting requirements outlined

in the SIP after July 1, 1994. The emission and process limitations

outlined above became effective on September 1, 1994. These timelines

allow Asarco sufficient opportunity to implement the control strategy,

and to gain operating experience before the requirements become

effective. The emission limitations went into effect September 1, 1994,

a date far in advance of the November 15, 1995 attainment date. EPA

concurs that this program constitutes adherence to an ambitious

compliance schedule and therefore demonstrates reasonable further

progress.

7. Contingency Measures

Section 172(c)(9) of the amended Act defines contingency measures

as measures in a SIP which are to be implemented if an area fails to

make RFP or fails to attain the NAAQS by the applicable attainment

date. Contingency measures become effective without further action by

the State or EPA, upon determination by EPA that the area has failed to

either make reasonable further progress or to attain the SO2 NAAQS

by the applicable statutory deadline. For SO2 programs, 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 the adoption of revised SIP's.

(See 57 FR 13547, April 16, 1992.)

The East Helena control strategy is based upon a dispersion

modeling analysis which indicates that the Primary SO2 NAAQS will

be protected. The use of continuous emission monitoring systems will

ensure that the emission limitations in the plan are not exceeded. In

addition, a compliance network of ambient air monitoring stations will

be maintained around the smelter at locations associated with predicted

maximum concentrations. This monitoring system should quickly identify

any violations of the NAAQS, if they should occur.

If violations should occur, the MDHES would immediately begin

negotiations with Asarco to reach agreement on control measures to

[[Page 5317]] correct the problem. Asarco would then implement those

measures to assure compliance as expeditiously as possible.

Additionally, the MDHES has emergency powers under Section 75.2.402 of

the Montana Clean Air Act to require curtailment of a source if the

source is causing imminent danger to human health or safety.

III. Stack Height Analysis

A. Background

On February 8, 1982 (47 FR 5864), EPA promulgated final regulations

limiting stack height credits and other dispersion techniques as

required by Section 123 of the CAA. These regulations were challenged

in the U.S. Court of appeals for the D.C. Circuit by the Sierra Club

Legal Defense Fund, Inc., the Natural Resources Defense Council, Inc.,

and the Commonwealth of Pennsylvania in Sierra Club v. EPA. On October

11, 1983, the court issued its decision ordering EPA to reconsider

portions of the stack height regulations, revising certain portions and

upholding other portions.

On February 28, 1984, the electric power industry filed a petition

for a writ of certiorari with the U.S. Supreme Court. On July 2, 1984,

the Supreme Court denied the petition, and on July 18, 1984, the Court

of Appeals mandate was formally issued, implementing the court's

decision and requiring EPA to promulgate revisions to the stack height

regulations within six months. The promulgation deadline was ultimately

extended to June 27, 1985.

Revisions to the stack height regulations were proposed on November

9, 1984 (49 FR 44878), and promulgated on July 8, 1985 (50 FR 27892).

The revisions redefined a number of specific terms including

``excessive concentrations,'' ``dispersion techniques,'' ``nearby,''

and other important concepts, and modified some of the bases for

determining good engineering practice (GEP) stack height.

Pursuant to section 406(d)(2) of the CAA, all States were required

to: (1) Review and revise, as necessary, their SIPs to include

provisions that limit stack height credit and dispersion techniques in

accordance with the revised regulations and (2) review all existing

emission limitations to determine whether any of these limitations have

been affected by stack height credits above GEP or any other dispersion

techniques. For any limitations so affected, States were to prepare

revised limitations consistent with their revised SIPs. All SIP

revisions and revised emission limits were to be submitted to EPA

within 9 months of the EPA stack height regulations promulgation.

Subsequently, EPA issued detailed guidance on carrying out the

necessary reviews. For the review of emission limitations, States were

to prepare inventories of stacks greater than 65 meters in height and

sources with emissions of sulfur dioxide (SO2) in excess of 5,000

tons per year. These limits correspond to the de minimis stack height

and the de minimis SO2 emission exemption from prohibited

dispersion techniques. These sources were then subjected to detailed

review for conformance with the revised regulations. State submissions

were to contain an evaluation of each stack and source in the

inventory.

Subsequent to the July 8, 1985 promulgation, the stack height

regulations were again challenged in NRDC v. Thomas, 838 F. 2d 1224

(D.C. Cir. 1988). On January 22, 1988, the U.S. Court of Appeals for

the D.C. Circuit issued its decision affirming the regulations for the

most part, but remanding three provisions to the EPA for

reconsideration. These are: Grandfathering stack height credits for

sources that raise their stacks prior to October 1, 1983, up to the

height permitted by GEP formula height (40 CFR 51.100 (kk)(21)),

dispersion credit for sources originally designed and constructed with

merged or originally designed and constructed with merged or multi-flue

stacks, (40 CFR 51.100 (hh)(2)(ii)(A)), and grandfathering credit for

the refined (H + 1.5 L) formula height for sources unable to show

reliance on the original (2.5H) formula (40 CFR 51.100 (ii)(2)).

B. State of Montana Submissions

EPA promulgated approval of a SIP revision which revised the

Administrative Rules of Montana governing stack height and dispersion

techniques on June 7, 1989 (54 FR 24334). In that same action, EPA

approved Montana's stack height demonstration analyses with the

exception of the Asarco East Helena lead smelter facility stacks. This

is the first time that EPA is taking action on the Asarco stacks.

C. Asarco, East Helena Stack Height Demonstration

EPA received a stack height review from Montana with a letter dated

November 25, 1985, and a subsequent submittal dated January 28, 1986.

With regard to the Asarco stack heights, the State found that no

existing emission limitations were affected by stack height credits

above GEP or any other dispersion technique prohibited by EPA

regulations.

EPA has determined that Montana's inventory of the Asarco facility

at East Helena is complete and has carefully reviewed the State's

findings. EPA concurs with those findings, which are summarized in the

table below. A detailed discussion of the Asarco stack height analysis

can be found in the TSD for this action.

------------------------------------------------------------------------

Actual

stack GEP

Stack I.D. height Applicable GEP formula height

(m) (m)

------------------------------------------------------------------------

Sinter.................... 128 Grandfathered (1939)...... .......

Blast Furnace............. 130 de minimis................ 65

Zinc Furnace.............. 107 (*) (*)

------------------------------------------------------------------------

*Source is shut down. New permit will be required to reopen zinc plant.

IV. Final Action

EPA is approving the East Helena primary SO2 NAAQS SIP

submitted to EPA on March 30, 1994. Among other things, the State of

Montana has demonstrated that the East Helena SO2 nonattainment

area will attain the primary SO2 NAAQS by November 15, 1995. EPA

is also approving stack height demonstrations for the Asarco, East

Helena, primary lead smelter.

Because EPA considers this action noncontroversial and anticipates

no adverse comments, this final approval is made without prior

proposal. This action will be effective March 28, 1995. However, if

adverse comments are received by February 27, 1995, then EPA would

withdraw this final approval action and this notice would instead stand

as a proposed rule. EPA would then address the comments in a subsequent

final promulgation notice.

Nothing in this action should be construed as permitting, allowing

or establishing a precedent for any future request for revision to any

SIP. Each request for revision to any SIP shall be considered

separately in light of specific technical, economic, and environmental

factors, and in relation to relevant statutory and regulatory

requirements.

The OMB has exempted this regulatory action from review under

Executive Order 12866.

Under the Regulatory Flexibility Act, 5 U.S.C. 600 et seq., 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, EPA may certify that the rule will not have a

significant economic impact on a substantial number of small entities.

Small entities [[Page 5318]] 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

Clean Air Act 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, I certify

that it does not have a significant impact on a substantial number of

small entities affected. Moreover, due to the nature of the Federal-

state relationship under the Clean Air Act, preparation of a regulatory

flexibility analysis would constitute Federal inquiry into the economic

reasonableness of state action. The Clean Air Act forbids EPA to base

its actions concerning SIPs on such grounds. Union Electric Co. v. U.S.

E.P.A.,427 U.S. 246, 256-66 (1976); 42 U.S.C. 7410 (a)(2).

Under section 307(b)(1) of the Act, petitions for judicial review

of this action must be filed in the United States Court of Appeals for

the appropriate circuit by March 28, 1995. 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 Act, section 307(b)(2).)

List of Subjects in 40 CFR Part 52

Environmental Protection, Air pollution control, Incorporation by

reference, Intergovernmental relations, Reporting and recordkeeping

requirements, Sulfur dioxide.

Dated: December 14, 1994.

William P. Yellowtail,

Regional Administrator.

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. 7401-7671q.

Subpart BB--Montana

2. Section 52.1370 is amended by adding paragraph (c)(37) to read

as follows:

Sec. 52.1370 Identification of plan.

* * * * *

(c) * * *

(37) The Governor of Montana submitted a SIP revision meeting the

requirements for the primary SO2 NAAQS State Implementation Plan

(SIP) for the East Helena, Montana nonattainment area with a letter

dated March 30, 1994. The submittal was to satisfy those SO2

nonattainment area SIP requirements due for East Helena on May 15,

1992.

(i) Incorporation by reference.

(A) Stipulation signed March 15, 1994, between the Montana

Department of Health and Environmental Sciences (MDHES) and Asarco,

Incorporated, which specifies SO2 emission limitations and

requirements for the company's primary lead smelter located in East

Helena, MT.

(B) Board order issued on March 18, 1994, by the Montana Board of

Health and Environmental Sciences approving and adopting the control

strategy for achieving and maintaining the primary SO2 NAAQS in

the East Helena area.

[FR Doc. 95-2017 Filed 1-26-95; 8:45 am]

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