Approval and Promulgation of State Implementation Plans; Utah Stack Height Analyses and Regulations

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[UT4-1-5628 and UT2-1-5441; FRL-4875-1]

Approval and Promulgation of State Implementation Plans; Utah

Stack Height Analyses and Regulations

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Governor of Utah submitted two revisions to the Utah State

Implementation Plan (SIP): Section 16, Stack Height Demonstration, and

Section 9, Part B, Sulfur Dioxide. Sections 16 and 9 were submitted in

letters dated December 23, 1991, and May 15, 1992, respectively. The

revisions to Section 16 were to address the stack-height demonstration

requirements for the Kennecott Minerals Company Smelter near Magna,

Utah. Minor corrections to the other stacks in the State were also

made. Section 9, Part B was revised to be consistent with Section 16.

Prior to the revision, the SO2 attainment demonstration for Salt

Lake County and portions of Tooele County was based on multipoint

rollback emission rates at the Kennecott smelter. The PM10 SIP

adopted for Salt Lake County in 1991 established significantly lower

emission rates (which would meet the 24-hour National Ambient Air

Quality Standard (NAAQS) for the smelter based on reasonable available

control technology (RACT). Section 16 and Section 9, Part B needed to

be consistent with the PM10 SIP (the PM10 SIP is located in

Section 9, Part A). In addition, Section 9 Part B was revised to

include an analysis and the emission limitation that would demonstrate

attainment of the 3-hour secondary NAAQS.

DATES: Comments must be received on or before May 18, 1994.

ADDRESSES: Written comments should be addressed to: Douglas Skie (ART--

AP) Air Programs Branch, EPA Region VIII, 999 18th St., suite 500,

Denver, Colorado 80202-2466.

Copies of the documents relevant to this proposed action are

available for public inspection between 8 a.m. and 4 p.m., Monday

through Friday, at the following office: Environmental Protection

Agency, Region VIII, Air Programs Branch, 999-18th Street, suite 500,

Denver, Colorado 80202-2466.

FOR FURTHER INFORMATION CONTACT: Lee Hanley, Air Programs Branch,

Environmental Protection Agency, Region VIII, 999-18th Street, suite

500, Denver, Colorado 80202-2466, (303) 293-1760.

SUPPLEMENTARY INFORMATION:

I. Background

A. Regulatory History

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 Clean Air Act (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, 719 F.2d 436 (DC Cir. 1983). On October 11, 1983, the court issued

its decision ordering EPA to reconsider portions of the stack height

regulations, while upholding other portions. As a result, EPA

promulgated revisions to the stack height regulations 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

credit.

Pursuant to Section 406(d)(2) as amended in the 1977 CAA, each

state was required to: (1) Review and revise its SIP, as necessary, to

include provisions that limit stack height credit and other 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 greater than

GEP, or any other dispersion techniques. For any limitations so

affected, each state was to prepare revised limitations consistent with

the revised stack height regulation.

Subsequently, EPA issued detailed guidance on carrying out the

necessary reviews. For the review of emission limitations, each state

was to prepare an inventory of stacks greater than 65 meters in height

and sources with emissions of sulfur dioxide (SO2) in excess of

5,000 tons per year (tpy). These limits correspond with the de minimis

stack height and the de minimis SO2 emission level provisions in

the regulations. These sources were then subjected to detailed review

for conformance with the revised federal 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:

1. Grandfathering pre-October 11, 1983 within-formula stack height

increases from demonstration requirements [40 CFR 51.100(kk)(2)];

2. Dispersion credit for sources originally designed and constructed

with merged or multiflue stacks [40 CFR 51.100(hh)(2)(ii)(A)]; and

3. Grandfathering pre-1979 use of the refined H + 1.5L formula [40

CFR 51.100(ii)(2)].

However, none of these provisions is at issue here.

B. Regulatory Requirement for Stacks Greater Than GEP

GEP has been established by the regulations to be the greater of:

(1) 65 meters, (2) the height derived through application of one of two

formulas which base GEP on the dimensions of nearby buildings, or (3)

the height demonstration through a field study or fluid modeling

demonstration to be necessary to avoid excessive concentrations of any

air pollutant due to downwash, eddies, or wakes caused by the source

itself or nearby buildings or terrain obstacles (40 CFR 51.100(ii).

Where EPA or a State finds that a source emission limit is affected by

dispersion from a stack in excess of GEP, the State must then model to

establish an emission limit which will provide for attainment of the

NAAQS when stack height credit is restricted to GEP.

The term ``excessive concentration'' is defined in the regulations

to be a 40% increase in concentrations of an air pollutant due to

downwash which also results in an exceedance of an applicable NAAQS or

prevention of significant deterioration (PSD) increment. In order to

demonstrate that stack height in excess of the GEP formulas is needed,

a source owner must show through the use of fluid modeling that, when

meeting emission rates equivalent to the new source performance

standard applicable to the source category, excessive concentrations

would result from the use of a shorter stack height. However, a source

may demonstrate that the NSPS emission limit is infeasible,

establishing an alternative emission limit that represents the most

stringent degree of emissions control feasible for the particular

source. In making this demonstration, source owners may generally rely

on EPA's Guidelines for the Determination of Best Available Retrofit

Technology for Coal-Fired Power Plants and Other Existing Stationary

Facilities, EPA 450/3-80-009b, November 1980 (BART Guideline).

C. The 1981 and 1986 SIP Submittals

1. The 1981 SO2 SIP Submittal

A Utah SO2 SIP revision was submitted with a letter dated

August 17, 1981, by the Governor of Utah to address the attainment of

the SO2 NAAQS in Salt Lake County and portions of the

nonattainment area in Tooele County. Additional information was

submitted by the State on December 7, 1981 and January 25, 1983. On

February 7, 1983, the Governor submitted a request to redesignate all

of Salt Lake County and the nonattainment portion of Tooele County to

attainment. On March 23, 1984 (49 FR 10926), EPA proposed to delay any

action on the request to redesignate the area to attainment until final

resolution of several issues. A detailed discussion of this SIP

revision is contained in the March 23, 1984 Notice of Proposed

Rulemaking and should be used as a reference for additional

information.

This SIP revision contained several complex national issues, such

as what constitutes ambient air and whether attainment demonstration is

sufficient without dispersion modeling or monitoring. Section 50.1 of

Title 40 Code of Federal Regulations (CFR) defines ``ambient air''

simply as ``that portion of the atmosphere, external to buildings, to

which the general public has access.'' Application of that regulatory

provision is based on an evaluation of where public lands are involved,

where private lands are subject to little restriction on access, or

conversely, where lands adjacent to a source are clearly restricted for

the public. Kennecott has maintained for some years, that public access

to the property (and therefore, the atmosphere) in question has been

and is precluded. The cumulative effect of Kennecott's property

holding, property exchanges, installation of fences, posts, no-

trespassing signs, and security patrolling, supports the Company's

claim to control use of the relevant property. There was information on

termination of limited elk hunting practices in the area. Kennecott's

man-made barriers, and other security measures, together with the

inherently rugged nature of the mountainous terrain involved, were

believed to effectively preclude access.

The control strategy for the 1981 SIP has several parts: (1)

Emission limitations on several low-level stacks at the smelter (e.g.,

boilers and heat treaters); (2) reasonably available measures to

control or eliminate fugitive emissions; and (3) cumulative emission

limits for the main stack (see additional discussion on these emission

limits in 2.b. below). The State's strategy was based upon measured

ambient data in the lower elevation near the smelter. EPA identified

the major deficiencies of the State analysis: (1) The State made no

attempt to demonstrate the effects in the upper elevation (above 5600

feet in the Oquirrh Mountains); and (2) the database at the smelter was

insufficient to be used reliably with the established emission limits,

given the assumption in the development of the emission limits

technique. Modeling analyses performed by the State and EPA to

demonstrate attainment in the upper elevation were screening analyses

only. EPA concluded that dispersion modeling in this complex terrain

was unreliable and that the only method that could be used for this

determination was monitoring. The 1981 SO2 SIP was conditionally

approved on the assumption that the emission limits were consistent

with federal 1985 stack height rules and, therefore, adequate for

attainment of the SO2 NAAQS. The redesignation of the area to

attainment was denied. (50 FR 7059, February 20, 1985)

2. The May 2, 1986 GEP SIP Submittal

The Utah Stack Height SIP was submitted by the Governor with a

letter dated May 2, 1986. The submittal included regulations to address

(1) GEP stack height credit and dispersion techniques, (2) a new

Section 17 of the SIP that listed all existing stacks in Utah greater

than 65 meters, and (3) a technical support document for Section 17 of

the SIP. The Kennecott Magna stack analyses were part of this

submittal. Subsequent submittals to support the Kennecott analyses were

received in letters dated October 6, 1986, December 3, 1986, November

13, 1987, and May 17, 1988.

The Kennecott smelter stack height credit was a significant

component of the Utah SO2 SIP emission limits conditionally

approved on February 20, 1985. Briefly, a condition in that approval

required the State to determine whether the 1215-foot stack would be

GEP once the revised stack height regulations were promulgated. If not,

the emission limits would then be revised as necessary.

a. Applicability of the NSPS Regulation. The federal NSPS

regulation for primary copper smelters applies to any such facility

that commences construction or modification after October 16, 1974 (42

FR 37937, July 25, 1977 and 40 CFR 60.160). Modification generally

means any physical or operational change which results in an increase

in the emission rate to the atmosphere. NSPS require, among other

things, control of the strong gas streams with a double contact acid

plant (i.e., a stack gas of 650 ppm or less SO2, based on a 6-hour

average (EPA 450/3-83-018a)).

The Kennecott Magna smelter expansion/modification began in the

early 1970s, with a commitment to the 1215-foot stack in 1973 and

completion of the project in 1977. The modification of the acid plant

system resulted in an increase from 60% sulfur capture to 86%,

approximately a 65% reduction of sulfur emissions. Based on this

information, EPA concluded that the 1970's Kennecott expansion/

modification did not subject the smelter to NSPS requirements.

b. Analyses on the 1986 Submittal. The Kennecott stack height

analyses were undertaken to comply with the July 8, 1985 stack height

regulation, as well as the condition specified in the approval of the

Utah SO2 SIP. The reader should refer to the February 2, 1985

final conditional approval (50 FR 7056) and March 23, 1984 proposed

approval (49 FR 10946) Federal Register actions for additional

information on the Utah SO2 SIP.

Kennecott originally had two 400-foot stacks (grandfathered stack

heights) from which SO2 emissions from the smelter were vented.

The 1970's modification/expansion included the replacement of the 400-

foot stacks with a single 1215-foot stack. The GEP formula height

(H+1.5 L), considering the nearby buildings, is 212.5 feet. The federal

regulation established the policy that sources faced with excessive

concentrations, due to downwash, should be required to attempt to

reduce those concentrations by reducing emissions to the degree

feasible before seeking credit above the GEP formula. The benchmark for

this requirement is the NSPS or the alternative level of control

established through the application of BART if the NSPS is found to be

infeasible. The demonstration that the NSPS is infeasible can be done

through a fluid modeling analyses.

The initial Kennecott GEP demonstration was submitted on May 2,

1986, with subsequent submittals on October 6, 1986, December 3, 1986,

November 13, 1987, and May 11, 1988. There are two basic parts to the

Kennecott analyses: the GEP demonstration and BART analysis. The GEP

demonstration consists of three subparts: the fluid modeling protocol,

the fluid modeling results, and an evaluation of the fluid modeling

results with respect to the stack height regulations. The BART analysis

is performed if the source contends that the NSPS emission limits are

infeasible. Relevant factors for this analysis include: high cost-

effectiveness ratio, excessive local community impact, excessive plant

impact, and technological infeasibility.

Since the Kennecott emissions, as established through Multi-point

Rollback (MPR), were used in the 1981 SO2 SIP, EPA's primary

concern, with the use of any emission rate in the demonstration of GEP,

is ensuring protection of the NAAQS (i.e., to protect health and

welfare). The basic concept behind GEP is to prevent sources from using

illegal dispersion techniques to avoid emissions controls.

Kennecott provided extensive data on its GEP analyses. The reader

is referred to 53 FR 48942 for information on the GEP demonstration and

BART analysis. To summarize, the GEP demonstration showed that the

existing stack height of 1215-foot (370.4m) met the 40% criterion due

to terrain effects and an exceedance of the NAAQS at MPR emission

rates. (Discussion of the MPR emission rates for Kennecott can be found

in 49 FR 10948, March 12, 1983, proposed rulemaking). MPR is a

technique designed for sources with variable emission rates (e.g.,

smelters). MPR allows for a frequency distribution of emission rates

which will permit extremely high emissions on rare occasions. The MPR

methodology is constructed around the recognition that any control

strategy will have a predictable probability of allowing a violation of

the NAAQS. The MPR is based upon allowing a 26% probability of

recording a violation (Additional information on MPR is found in

Appendix A). The GEP demonstration satisfies the excessive

concentration criteria in EPA's regulation if MPR reflects the proper

emission rates. After review, EPA concluded that Kennecott's analyses

were acceptable, since Kennecott performed a fluid modeling study

consistent with existing guidance and the study was approved by EPA.

The purpose of establishing a BART emission rate in the 1985 stack

height regulations was to prevent source owners from using unreasonably

high emission rates to justify credit for excessive stack heights. The

regulation requires that sources faced with excessive concentrations

due to downwash should be required to attempt to reduce those

concentrations by reducing those emissions to the degree feasible

before seeking credit above the GEP formula. The benchmark for this

requirement is the NSPS, or an alternative level of control established

through the application of BART if NSPS is found to be infeasible.

Kennecott provided responses to all the BART factors mentioned above.

The cost-effectiveness ratio and technical infeasibility issues,

however, were determined critical to this review because of their

relationship to the emission limitations used in the GEP analyses.

Application of the level of control required by NSPS would reduce

the emissions of SO2 at Kennecott during the stable process phase,

but would not affect emission rates under startup, shutdown,

malfunction, and upset conditions. This is because the NSPS emission

rate is for normal operations and excludes such process conditions. MPR

includes startup, shutdown, malfunction, and upset conditions. From the

Kennecott assessment, considering only long-term averages, the cost

portion is consistent with the tons of SO2 reduction expected from

similar NSPS applications. In the Kennecott BART analysis, the

controlling emissions for the determination of GEP appear to be those

under upset, start-up, shutdown, and malfunction. Therefore, while

there would be no difference in the emission rates under these

conditions as a result of meeting NSPS, there would be a substantial

additional cost to control these emissions.

In summary, the emissions at the smelter from startups, shutdowns,

upsets, and malfunctions are included in the MPR emission limits and

could be considered in the NAAQS attainment and GEP analyses.

Application of NSPS technology will not affect these emission rates and

will, therefore, result in no change in demonstrating GEP. It may be

possible to reduce annual emissions by requiring additional controls on

the smelter, but such reduction would have no relevance to the limiting

case for determination of GEP.

Given the above discussion, EPA proposed to approve (53 FR 48942,

December 5, 1988) the Kennecott analysis in the Utah GEP SIP submitted

on May 2, 1986, with subsequent submittals on October 6, 1986, December

3, 1986, November 13, 1987, and May 17, 1988. However, EPA's review was

conducted under a specific assumption: that the emission rate(s) in the

SO2 SIP were sufficient to demonstrate attainment. That assumption

followed another critical assumption: that Kennecott owned or

controlled the lands in the upper elevation for which no monitoring

data exist to demonstrate attainment of the NAAQS.

Only one comment was received in response to the December 5, 1988

Federal Register proposed approval of the Kennecott GEP demonstration.

The comment was from Kennecott in support of this action. However,

prior to publication of the proposed approval Federal Register, EPA did

receive a letter from a landowner in the Oquirrh Mountains expressing

concerns due to the lack of ambient monitoring in the nonattainment

area. This was EPA's first documented information on public access in

the nonattainment area other than the Kennecott operation. EPA

proceeded to continue its evaluation of the State submittal and to

publish its position on the GEP demonstration based on the State

submittal, but initiated a reevaluation on land ownership above the

5600-ft. elevation in the Oquirrh Mountains. Documentation on the claim

of land ownership, other than that of the Kennecott operations, was

provided by Howard Haynes, Jr. in March 1989.

3. Utah 1981 SO2 and 1986 GEP SIP Reassessment

Data from the Salt Lake County and Tooele County Assessor offices

showed over 80 landowners in this nonattainment area. Kennecott, in its

land ownership research, verified the list of landowners.

As stated above, one of the critical assumptions of the conditional

approval of the 1981 SO2 SIP and the emission rate was Kennecott's

ownership or control of those lands in the potential nonattainment area

in the Oquirrh Mountains. The land ownership research revised the EPA's

earlier assumptions on the adequacy of the 1981 SO2 and the 1986

GEP Stack SIPs.

EPA entered into discussions with Kennecott and the State for

resolution of these issues and attempted to outline the procedures for

addressing the SO2 and GEP SIPs. Documentation of these meetings

and discussions is found in EPA letters to the State dated July 12,

1989, and August 14, 1989. Since monitoring has been stated as the only

method to conclusively determine the attainment status of lands in the

Oquirrh Mountain, the State and Kennecott proceeded to develop a

monitoring program. Maximum ambient concentration location of the

monitors, access to the monitors, and operational logistics of the

monitor(s) were key problems identified.

During these negotiations, the State was developing the PM10

SIP for Salt Lake County. The Salt Lake County PM10 SIP

development process identified SO2 as a precursor for PM10.

(Precursors are secondary particles which are formed in the atmosphere

from gases which are directly emitted by the source. Sulfates are one

of the most common secondary particles in a PM10 nonattainment

area and result from sulfur dioxide emissions.) The Kennecott smelter

SO2 emissions comprised 56% of the total (primary and

secondary) PM10 emissions in Salt Lake County.

The PM10 SIP was adopted by the State in August 1991 and

submitted to EPA in November 1991. The reader is referred to 57 FR

60149, December 18, 1992, for information on the PM10 SIP. The

PM10 SIP required significant emission reduction for the Kennecott

operations (refinery, concentrator, mine, power plant and smelter). The

Kennecott smelter emission limits were reduced from 76,000 tpy or

18,000 lb/hr annual average (as allowed in the 1981 SO2 and 1986

GEP SIPs) to 18,500 tpy (which includes fugitive emissions,

and applies to the entire smelter). (The 1981 SO2 and 1986 GEP

SIPs addressed emissions from smelter processing units and SO2

collection and removal equipment vented to the smelter tall stack. They

did not include fugitive emissions. For clarification, the 76,000 tpy

was reduced to the 14,191 tpy limit on the 1215-foot stack for

emissions from the smelter processing units and SO2 collection and

removal equipment).

D. The 1991 GEP and 1992 SO2 SIP Submittals

Prior to the State's adoption of the PM10 SIP, EPA discussed

the uncertainties of finalizing the 1986 GEP SIP with the State and

Kennecott. EPA clarified its position on the need for consistency

within the Utah SIP with respect to emission limitations at the

Kennecott smelter. In a letter dated July 18, 1991, EPA outlined the

SIP Revisions that must occur to address the inconsistencies between

the 1981 SO2 SIP, the 1986 GEP SIP, and 1991 PM10 SIP. To

summarize, EPA stated that it could not knowingly and legally proceed

to approve a regulation and emission limitation that were no longer

applicable, or a stack height demonstration analysis based on an

obsolete regulation or emissions limitation.

In a letter dated December 23, 1991, the Governor of Utah submitted

a revision to Section 16, Demonstration of GEP Stack Height, of the

Utah SIP. The 1991 submittal was received on December 30, 1991. On

February 28, 1992, EPA advised the Governor of Utah that this submittal

was administratively and technically complete in accordance with the

Federal SIP completeness criteria.

The revisions to Section 16 specify the allowable emission limit

for the 1215-foot main stack at 14,191 tons/year as derived in the

PM10 SIP. This emission limit is based on double contact acid

plant technology (which is considered NSPS for the smelter acid plant

tail gas), significant capture improvement of fugitive emissions, and

improved operation and maintenance. The 1991 submittal also contained a

reanalysis of other sources in the State for which stack heights above

the deminimus level (65m) were previously reported. (These sources'

stack heights were published in 54 FR 24334, June 7, 1989.)

EPA found minor changes between the June 7, 1989 Federal Register

and the 1991 revision to Section 16 for the ``actual'' stack height of

some sources. EPA is not concerned with these minor changes since they

could be attributed to errors in rounding and the stack height changes

are less than one foot. Listed below are the differences between the

June 7, 1989 Federal Register and the 1991 submittal:

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

June 7, 1989 1991

Source FR revision

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

Desert Units 1 and 2......................... 182.9m 182m

UP&L Hunter Units 1 and 2.................... 183.08m 183m

UP&L Hunter Unit 3........................... 183.1m 183m\1\

UP&L Huntington Units 1 and 2................ 182.93m 183m

IPP Units 1 and 2............................ 216.46m 216m

Chevron USA HCC cracker...................... 1946\1\ 1950\2\

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\1\The State indicated very insignificant changes to these sources

``calculated'' GEP stack heights; the State has indicated that the

``actual'' height will be the enforceable stack height.

\2\Correction of grandfathered date.

The State's revised analyses are presented in the table below.

Detailed documentation for these analyses and the corresponding EPA

review is contained in the EPA technical support document and air

compliance files, and the State files.

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

Allowable

Stack SO2

Source name height emissions

(M) (ton/year)

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

Deseret Units 1&2............................... 182 1,512

U.P.&L. Hunter Units 1&2........................ 183 4,347

U.P.&L. Hunter Unit 3........................... 183 1,283

U.P.&L. Huntington Units 1&2.................... 183 9,448

I.P.P. Units 1&2................................ 216 17,870

U.P.&L. Gadsby Units 1,2&3...................... 76.2 +67.7

Geneva Steel blast furnaces 1&2................. 79.2 +*12.5

Geneva Steel Coke blast furnace................. 68.6 ............

Geneva Steel Coke Combustion 1-4................ 76.2 +102.8

Kennecott Utah Copper Smelter Main Stack........ 370 +*14,191

Chevron USA HCC Cracker Cat. Dis................ 88.4 +66.7

Chevron Research Air Heater..................... 69.8 0

Chevron Research Retort......................... 69.8 +0

Amax melt reactor............................... 76.22 0

Amax electrolytics.............................. 76.22 0

Amax emergency off gas.......................... 76.22 0

Amax spray dryers 1-3........................... 76.22 83

Phillips thermal cat. cracking.................. 80.8 +3.5

White River Shale Lift Pipes.................... 76.2 ............

White River Elutriators......................... 76.2 ............

White River Hydrogen Plant...................... 76.2 ............

White River Power Plants........................ 76.2 ............

White River Ball Heaters........................ 76.2 *1,180.8

Tosco Preheat Stacks............................ 95 -

Tosco Warm Ball Elutriators..................... 95 -

Tosco Process Shale Wetters..................... 95 *1,166.6

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

+SO2 emissions derived from the PM10 SIP adopted August 14, 1991.

*The total SO2 emissions are given for these sources.

On May 15, 1992, the Governor of Utah submitted a revision to

Section 9, Part B, Sulfur Dioxide, Utah SIP. The revision was to

address the 1990 CAA requirement that a SIP revision be submitted by

May 15, 1992, for any area that did not have a fully approved SIP (the

1981 SO2 SIP was only conditionally approved). The significant

change in this SIP revision from that of the 1981 submittal is as

follows:

a. The MPR emission limitations and assumptions are removed and

replaced with the emission limitation which can be achieved using the

NSPS technology, double contact acid plant, or the equivalent of NSPS.

(NSPS is the presumptive norm for RACT for this facility.) The SO2

SIP now references the same emission limitations as those stated in

PM10 SIP.

b. The SO2 NAAQS are the 0.14ppm, 24-hour primary standard,

and the 0.5ppm, 3-hour secondary standard. The 24-hour impact analysis

was a rollback analysis which compared the smelter emissions in 1991

(PM10 SIP emission limitation) with 1979 emissions. The State had

monitoring data showing attainment at Lake Point (an area originally

defined as ambient air and owned by the Bureau of Land Management, but

now owned by Kennecott) where exceedances were recorded. The Lake Point

site could be considered representative of the closest point in the

elevated terrain that would be impacted by the tall stack emissions.

Demonstrating attainment at Lake Point would technically support the

attainment elsewhere in the elevated terrain that is considered ambient

air. The area considered ambient air in the elevated terrain is a

significant distance downwind from Lake Point.

c. The PM10 SIP addressed, to some degree, the 3-hour impact.

The PM10 SIP emission limitation was based on a 24-hour SO2

limit; this emission limitation would be achieved through a given lb/hr

calculated on a 6-hour average. The 24-hour limit was considered

``controlling'' for PM10 and SO2 (i.e., the 24-hour

limitation was believed to be the level of control necessary for

PM10 attainment, as well as for the SO2 attainment

demonstration). The SO2 SIP established a 3-hour limitation and

verified that such limitation would protect the 3-hour NAAQS.

d. Section 4.2 of the Utah Air Conservation Regulations was revised

to include a 24-hour averaging period for the sulfur content of coal,

fuel oil, and fuel mixtures, and to specify the ASTM methods to be used

to demonstrate compliance with the limitation and reporting

requirement. (The previous rule specified a limit for the sulfur

content of fuels, but did not specify an averaging time or specific

ASTM methods.) Section 4.6 was also revised to include a 3-hour

averaging time for Sulfur Burning Production Sulfuric Acid Plants.

e. Specific regulations which provided for special consideration

(including malfunction provisions) on the smelter fluctuating operation

are removed. Malfunction provisions for the Kennecott smelter operation

are now the same as for any stationary source in Utah. This issue was

addressed during the PM10 SIP development and is being approved

under the PM10 SIP federal approval process. These regulation

impacts were clarified in this SIP revision.

II. This Action

The December 23, 1991 Section 16, Stack Height revision and the May

15, l992 Section 9, Part B, SO2 revision are consistent with other

provisions in the State-wide SIP. EPA is proposing to approve these

revisions because they are consistent with EPA guidance for GEP stack

height demonstration and the attainment demonstration for the SO2

NAAQS.

These revisions resolve EPA's concerns regarding ambient air,

attainment demonstration in the elevated terrain, and the

enforceability issues related to the smelter operations. The previous

emission limitations have been the subject of litigation filed by the

Environmental Defense Fund. The legal actions have been stayed pending

EPA final action on the past SIP revisions. The 1991 and 1992 revisions

are believed to have settled the litigants' concerns about applying

reasonable control technology and demonstrating attainment per the

traditionally accepted federal requirements (i.e., application of RACT

(double contact acid plant or the equivalent), monitoring

demonstration, etc).

Request for Public Comment

The EPA is requesting comments on all aspects of today's proposal.

As indicated at the outset of this document, EPA will consider any

comments received by May 18, 1994.

Nothing in this action should be construed as permitting or

allowing or establishing a precedent for any future request for

revision to any State Implementation Plan. Each request for revision to

any State Implementation Plan shall be considered separately in light

of specific technical, economic, and environmental factors and in

relation to relevant statutory and regulatory requirements.

Regulatory Flexibility

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 impact on a substantial number of small entities. Small

entities include small businesses, small not-for-profit enterprises,

and government entities with jurisdiction over population 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, I certify 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 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).

Executive Order 12866

The Office of Management and Budget has exempted this rule from the

requirement of section 6 of Executive Order 12866.

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), as revised by an October 4, 1993,

memorandum from Michael H. Shapiro, Acting Assistant Administrator for

Air and Radiation. A future document will inform the general public of

these tables. On January 6, 1989, the Office of Management and Budget

(OMB) waived Table 2 and Table 3 SIP revisions (54 FR 222) from the

requirements of section 3 of Executive Order 12291 for 2 years. The EPA

has submitted a request for a permanent waiver for Table 2 and Table 3

SIP revisions. The OMB has agreed to continue the waiver until such

time as it rules on EPA's request. This request continues in effect

under Executive Order 12866 which superseded Executive Order 12291 on

September 30, 1993.

List of Subjects in 40 CFR Part 52

Environmental protection, Air pollution control, Reporting and

recordkeeping requirements, and Sulfur dioxide.

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

Dated: March 31, 1994.

Jack W. McGraw,

Acting Regional Administrator.

[FR Doc. 94-9292 Filed 4-15-94; 8:45 am]

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