Clean Air Act Approval and Promulgation of PM-10 Implementation Plan for Colorado

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[CO32-1-5982; FRL-4855-7]

Clean Air Act Approval and Promulgation of PM-10 Implementation

Plan for Colorado

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rulemaking.

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

SUMMARY: In this action, the EPA proposes approval of the State

implementation plan (SIP) submitted by the State of Colorado for the

purpose of bringing about the attainment of the national ambient air

quality standards (NAAQS) for particulate matter with an aerodynamic

diameter less than or equal to a nominal 10 micrometers (PM-10). The

SIP was submitted by the State on May 27, 1993 to satisfy certain

federal Clean Air Act requirements for an approvable moderate

nonattainment area PM-10 SIP for Lamar, Colorado.

DATES: Comments on this proposed action must be received in writing by

May 6, 1994.

ADDRESSES: Written comments should be addressed to: Vicki Stamper,

8ART-AP, Environmental Protection Agency, Region VIII, 999 18th Street,

suite 500, Denver, Colorado 80202-2466.

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.

Air Pollution Control Division, Colorado Department of Health, 4300

Cherry Creek Drive South, Denver, Colorado 80222-1530.

FOR FURTHER INFORMATION CONTACT: Vicki Stamper, 8ART-AP, Environmental

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

Colorado 80202-2466, (303) 293-1765.

SUPPLEMENTARY INFORMATION:

I. Background

Lamar, Colorado was designated nonattainment for PM-10 and

classified as moderate under sections 107(d)(4)(B) and 188(a) of the

Clean Air Act (Act) upon enactment of the Clean Air Act Amendments of

1990.\1\ (See 56 FR 56694, November 6, 1991 and 40 CFR 81.306.) The air

quality planning requirements for moderate PM-10 nonattainment areas

are set out in subparts 1 and 4 of part D of title I of the Act. The

EPA has issued a ``General Preamble'' describing EPA's preliminary

views on how EPA intends to review SIPs and SIP revisions submitted

under title I of the Act, including those State submittals containing

moderate PM-10 nonattainment area SIP requirements (see generally 57 FR

13498 (April 16, 1992) and 57 FR 18070 (April 28, 1992)). 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 this proposal and the

supporting rationale. In this rulemaking action on the Colorado

moderate PM-10 SIP for the Lamar PM-10 nonattainment area, EPA is

proposing to apply its interpretations taking into consideration the

specific factual issues presented. Thus, EPA will consider any timely

submitted comments before taking final action on this proposal.

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

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

changes to the Act. See Pub. L. 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. 7401, et seq.

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

Those states containing initial moderate PM-10 nonattainment areas

were required to submit, among other things, the following provisions

by November 15, 1991:

1. Provisions to assure that reasonably available control measures

(RACM) (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--RACT) shall be implemented no

later than December 10, 1993;

2. Either a demonstration (including air quality modeling) that the

plan will provide for attainment as expeditiously as practicable but no

later than December 31, 1994 or a demonstration that attainment by that

date is impracticable;

3. Quantitative milestones which are to be achieved every 3 years

and which demonstrate reasonable further progress (RFP) toward

attainment by December 31, 1994; and

4. Provisions to assure that the control requirements applicable to

major stationary sources of PM-10 also apply to major stationary

sources of PM-10 precursors except where the Administrator determines

that such sources do not contribute significantly to PM-10 levels which

exceed the NAAQS in the area. See sections 172(c), 188, and 189 of the

Act.

Some provisions are due at a later date. States with initial

moderate PM-10 nonattainment areas were required to submit a permit

program for the construction and operation of new and modified major

stationary sources of PM-10 by June 30, 1992 (see section 189(a)). Such

States also must submit contingency measures by November 15, 1993 which

become effective without further action by the State or EPA, upon a

determination by EPA that the area has failed to achieve RFP or to

attain the PM-10 NAAQS by the applicable statutory deadline. See

section 172(c)(9) and 57 FR 13510-13512, 13543-13544.

II. This Action

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

review of SIP submittals (see 57 FR 13565-13566). In this action, EPA

is proposing to grant approval of the Lamar plan revision which was due

to EPA on November 15, 1991 and submitted by the State on May 27, 1993.

EPA believes the attainment plan for Lamar meets all of the applicable

requirements of the Act.

Since the Lamar PM-10 SIP was not submitted by November 15, 1991 as

required by section 189(a)(2)(A) of the Act, EPA made a finding

pursuant to section 179 of the Act that the State failed to submit the

SIP and notified the Governor in a letter dated December 16, 1991. See

57 FR 19906 (May 8, 1992). After the Lamar PM-10 SIP was submitted on

May 27, 1993, EPA found the submittal to be complete pursuant to

section 110(k)(1) of the Act and notified the Governor accordingly in a

letter dated June 14, 1993. This completeness determination corrected

the State's deficiency and, therefore, terminated the 18-month

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 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.\2\ Section 110(l) 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.

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

\2\Also Section 172(c)(7) of the Act requires that plan

provisions for nonattainment areas meet the applicable provisions of

section 100(a)(2).

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

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 (1992). 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 6 months after

receipt of the submission.

After providing more than 30 days of prior public notice, the State

of Colorado held a public hearing on April 15, 1993 to entertain public

comment on the implementation plan for Lamar. The plan for Lamar was

subsequently adopted by the State and submitted by the Governor by

letter dated May 27, 1993 as a proposed revision to the SIP. EPA

received the submittal on June 3, 1993.

The SIP revision was reviewed by EPA to determine completeness

shortly after its submittal, 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 June 14, 1993 was forwarded to the

Governor indicating the completeness of the submittal and the next

steps to be taken in the review process. In this action, EPA proposes

to approve the State of Colorado's PM-10 SIP submittal for Lamar

relative to those moderate area PM-10 SIP requirements due on November

15, 1991 and invites public comment on the action.

2. Accurate Emissions 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 emissions inventory should also include a

comprehensive, accurate, and current inventory of allowable emissions

in the area. Because the submission of such inventories is a necessary

adjunct to an area's attainment demonstration (or demonstration that

the area cannot practicably attain), the emissions inventories must be

received with the submission (see 57 FR 13539).

The State of Colorado submitted a winter/spring season emissions

inventory for the base year of 1992. A winter/spring season emissions

inventory was calculated because the highest PM- 10 concentrations

generally occur in the winter/spring season in Lamar. The base year

inventory identified area sources as the primary cause of high PM-10

concentrations, which contributed 99 percent of the total emissions,

with wind erosion from agriculture lands contributing 49 percent, re-

entrained road dust from paved and unpaved roads contributing 24

percent, cattle feedlots contributing 15 percent, residential wood

burning contributing 8 percent, and point sources contributing 1

percent. The remaining 3 percent of PM-10 emissions was due to

emissions from tailpipes, agricultural tilling, and storage piles. The

emission inventory demonstrates that wind erosion from agricultural

land is the principal contributor to PM-10 emissions in the Lamar

nonattainment area. However, the State and EPA believe that during the

conditions when the PM-10 exceedances have been known to occur (high

wind days preceded by warm, dry weather), PM-10 from wind erosion may

be coming into the area from land much farther away than the area

modeled by the State in developing the Lamar PM-10 emissions inventory.

Thus, on the high wind days, agricultural emissions not in the

immediate area surrounding Lamar may represent a much greater

contribution to total PM-10 emissions in the area. However, emissions

from such sources not in the immediate area surrounding Lamar were

difficult to estimate.

The EPA is proposing to approve the emissions inventory because it

generally appears to be 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.\3\ For further details

see the Technical Support Document (TSD).

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

\3\The EPA issued guidance on PM-10 emissions inventories prior

to the enactment of the Clean Air Act Amendments in the form of the

1987 PM-10 SIP Development Guideline. The guidance provided in this

document appears to be consistent with the revised Act.

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

3. RACM (Including RACT)

As noted, the initial moderate PM-10 nonattainment areas must

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

no later than December 10, 1993 (see sections 172(c)(1) and

189(a)(1)(C) of the Act). The General Preamble contains a detailed

discussion of EPA's interpretation of the RACM (including RACT)

requirement (see 57 FR 13539-13545 and 13560-13561). In Lamar, wind

erosion from agricultural farmland in the area was identified as the

principal contributor to the PM-10 nonattainment problem, and these

emissions will be controlled through reliance on the soil conservation

measures of the Food Security Act (FSA). See e.g., 16 U.S.C. 3801,

3811-3813.

The FSA, which was enacted in 1985, applies to any farmer

participating in a federal farm subsidies program. One of the main

provisions of the FSA requires farmers who cultivate highly erodible

land (which includes the majority of the farmland surrounding Lamar) to

develop and implement soil conservation plans. The conservation plan is

to document the decisions of an affected farmer with respect to

location, land use, tillage systems, and conservation treatment

measures and schedules. The plan is to be based on the local Soil

Conservation Service technical guide, and it is to be approved by the

local soil conservation district. See 16 U.S.C. 3812(a)(2). The law

provides that if such a conservation plan is actively applied by

January 1, 1990 or 2 years after the Soil Conservation Service has

completed a soil survey for the farm, whichever is later, affected

farmers shall have until January 1, 1995 to comply with the plan

without being subject to ineligibility for certain program loans,

payments, and benefits.

In the area surrounding Lamar, approximately 75-80 percent of the

agricultural lands are subject to the soil conservation requirements.

According to the Southeast Regional Soil Conservation Service (SCS)

office, all of the farmers subject to the FSA in the Lamar area have

developed conservation plans, and most of the farmers in the Lamar area

have already begun at least partial implementation of these plans.\4\

The local SCS office has estimated that the implementation of these

plans will result in a 70 percent reduction in wind erosion emissions

from the non-irrigated farmland surrounding Lamar (which represents 85

percent of the farmland subject to the FSA in the Lamar area).

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

\4\Per December 4, 1992 telephone coversation between Vicki

Stamper, U.S. EPA Region VIII, and Lorenz Sutherland, Southeast

Colorado Regional SCS office.

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

While the State is relying on these provisions to reduce the PM-10

emissions from wind erosion in the Lamar area, the State did not adopt

these measures into the SIP or take credit for these control measures.

Since these measures are federally mandated and will be implemented by

the U.S. Department of Agriculture, it is not necessary for the State

to adopt these measures into the SIP. No credit was taken for these

measures because of the difficulty in estimating the effectiveness of

these measures and, moreover, because no credit was needed to

demonstrate attainment or maintenance of the PM-10 NAAQS in Lamar (see

section II.A.4. of this document). Nevertheless, EPA does believe that

the provisions of the FSA will have a significant impact on the

emissions from wind erosion from agricultural land in the Lamar area.

RACT does not require controls on stationary sources in the Lamar

nonattainment area because the point source emissions in the Lamar area

are de minimis, and control of such sources would not expedite

attainment and maintenance of the PM-10 NAAQS. See 57 FR 13540, 13543.

There are also Statewide control measures that apply in the Lamar

area. Colorado Regulation No. 4 requires new wood stoves to meet the

emission requirements of EPA's Standards of Performance for New

Residential Wood Heaters in 40 CFR 60.532(b). Colorado Regulation No. 3

regulates the construction and modification of new stationary sources

of PM-10.\5\ These measures will help to reduce emissions from new

stationary source growth and residential wood combustion.

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

\5\The State is required by the amended Clean Air Act to adopt a

revised new source review permit program for the construction and

operation of new and modified stationary sources. See Section

189(a)(1)(A). This SIP revision, which was submitted by the State on

January 15, 1993, was due independent of the November 15, 1991

moderate PM-10 nonattainment area SIP requirements addressed in this

action and will be addressed in a separate notice. See section

189(a)(2)(A) of the Act.

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

A more detailed discussion of the individual source contributions,

the associated control measures, and an explanation as to why certain

available control measures were not adopted, can be found in the TSD.

EPA has reviewed the State's explanation and associated documentation

and concluded that it adequately justifies the control measures to be

implemented. The Lamar PM-10 SIP demonstrates that the area will attain

the PM-10 NAAQS by December 31, 1994. By this notice, EPA is proposing

to approve Colorado's SIP submittal for Lamar as meeting the RACM

(including RACT) requirement. However, EPA is not proposing action on

Regulations No. 3 and 4 because EPA has previously approved these

regulations in separate actions (see the TSD for further information).

4. Demonstration

As noted, the initial moderate PM-10 nonattainment areas must

submit a demonstration (including air quality modeling) showing that

the plan will provide for attainment as expeditiously as practicable

but no later than December 31, 1994 (see section 189(a)(1)(B) of the

Act). Alternatively, the State must show that attainment by December

31, 1994 is impracticable.

EPA regulations provide that the adequacy of a control strategy to

provide for timely attainment must be demonstrated by means of a

proportional model or dispersion model or other procedure which is

shown to be adequate and appropriate (see 40 CFR 51.112(a)). EPA policy

specifies that the preferred approach for estimating the air quality

impacts of emissions of PM-10 is to use receptor modeling in

combination with dispersion modeling. However, on July 5, 1990, EPA

issued guidance providing that, in certain situations, it may be more

appropriate to rely on a receptor model demonstration alone as the

basis for the attainment demonstration (see July 5, 1990 memo to

Regional Air Branch Chiefs from Robert D. Bauman, Chief of SO2/

Particulate Matter Programs Branch and Joseph Tikvart, Chief of Source

Receptor Analysis Branch). Lamar met the criteria discussed in the July

5, 1990 memo to justify using receptor modeling alone and had

originally planned to use this approach in its attainment

demonstration. However, after further review, the State determined that

the chemical mass balance (CMB) analysis (i.e., analysis of source

contributions from PM-10 monitoring filters) to be used in the receptor

model was inadequate and decided to base the attainment and maintenance

demonstration on simple emissions rollback modeling, which involves

using the ratio of the design day ambient concentration of 101

g/m\3\ to the design day emissions and projecting future

concentrations.

Because the Lamar attainment and maintenance demonstrations did not

follow EPA general guidance, the State included a commitment in the

Lamar PM-10 SIP to conduct revised CMB analyses on all filters greater

than 100 g/m\3\ and to use this information to assess the

adequacy of the SIP. On September 20, 1993, the State submitted the

revised CMB analysis but did not utilize the results in calculating a

revised attainment and maintenance demonstration. The State determined

that the receptor modeling performed for Lamar did not provide the

conclusive source contribution information that would be necessary in

order to adequately revise the Lamar PM-10 attainment and maintenance

demonstrations. EPA has reviewed the State's analysis and concurs with

the State's justification for using emissions rollback modeling in its

attainment demonstration. In addition, because the emissions rollback

modeling demonstration accounted for growth in source categories that

were not even identified in the CMB analysis, EPA believes that the use

of emissions rollback modeling provides for a more conservative

prediction of future concentrations. Thus, EPA believes that the

State's attainment demonstration adequately demonstrates that the Lamar

PM-10 nonattainment area will remain in attainment and maintain the 24-

hour PM-10 NAAQS. (See the TSD for further information.)

The 24-hour PM-10 NAAQS is 150 g/m\3\, and the standard is

attained when the expected number of days per calendar year with a 24-

hour average concentration above 150 g/m\3\ is equal to or

less than one (see 40 CFR 50.6). The annual PM-10 NAAQS is 50

g/m\3\, and the standard is attained when the expected annual

arithmetic mean concentration is less than or equal to 50 g/

m\3\ (id.). The demonstration predicted that the 24-hour design

concentration in the attainment year of 1994 will be 115 g/

m\3\, thus demonstrating attainment of the 24-hour PM-10 NAAQS. The

demonstration also showed that the PM-10 NAAQS will be maintained in

future years by predicting a 24-hour design concentration in 1997 of

116 g/m\3\.

Since no violations of the annual PM-10 NAAQS have been monitored

in the Lamar area and since the attainment demonstration in the Lamar

PM-10 SIP clearly shows attainment and maintenance of the 24-hour PM-10

NAAQS, it is reasonable and adequate to assume that protection of the

24-hour standard will be sufficient to protect the annual standard as

well. For a more detailed description of the attainment demonstration,

see the TSD accompanying this document.

5. PM-10 Precursors

The control requirements which are applicable to major stationary

sources of PM-10 also apply to major stationary sources of PM-10

precursors, unless EPA determines such sources do not contribute

significantly to PM-10 levels in excess of the NAAQS in that area (see

section 189(e) of the Act).

The analysis of the air quality and emissions data for the Lamar

nonattainment area indicates that the PM-10 exceedances in the Lamar

area are generally attributable to particulate matter emissions from

area sources, mainly windblown emissions from agricultural lands, re-

entrained road dust, cattle feed lots, and residential wood combustion.

In addition, the emissions inventory for this area did not reveal any

major stationary sources of PM-10 precursors. Consequently, EPA is

proposing to find that major stationary sources of precursors of PM-10

do not contribute significantly to PM-10 levels in excess of the NAAQS.

If finalized, this finding would exclude major stationary sources of

PM-10 precursors from the applicability of PM-10 nonattainment area

control requirements. Further discussion of the analyses and supporting

rationale for EPA's proposed finding are contained in the TSD

accompanying this document. Note that while EPA is making a general

finding for this area, this finding is based on the current character

of the area including, for example, the existing mix of sources in the

area. It is possible, therefore, that future growth could change the

significance of precursors in the area. The EPA intends to issue future

guidance addressing such potential changes in the significance of

precursor emissions in an area.

6. Quantitative Milestones and Reasonable Further Progress

The PM-10 nonattainment area plan revisions demonstrating

attainment must contain quantitative milestones which are to be

achieved every 3 years until the area is redesignated attainment and

which demonstrate RFP, as defined in section 171(1), toward attainment

by December 31, 1994 (see section 189(c) of the Act). RFP is defined in

section 171(1) as such annual incremental reductions in emissions of

the relevant air pollutant as are required by part D or may reasonably

be required by the Administrator for the purpose of ensuring attainment

of the applicable NAAQS by the applicable date.

In implementing the quantitative milestone and RFP provisions for

this initial moderate area, EPA has reviewed the attainment

demonstration for the area to determine the nature of any milestones

necessary to ensure timely attainment and whether annual incremental

reductions should be required in order to ensure attainment of the PM-

10 NAAQS by December 31, 1994 (see section 171(1)). Because the Lamar

area can demonstrate expeditious attainment of the PM-10 NAAQS without

taking credit for the reliance on the soil conservation plans, no

further reductions are necessary. Therefore, EPA believes the Lamar PM-

10 SIP satisfies the quantitative milestone and RFP requirement.

However, there will be emissions reductions that occur as a result of

the federally mandated soil conservation plans, which will help to

ensure that the area attains and maintains the PM-10 NAAQS.

7. Enforceability Issues

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

the State and EPA (see sections 172(c)(6), 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

must also contain a program that provides for enforcement of the

control measures and other elements in the SIP (see section

110(a)(2)(C)).

The specific control measures contained in the SIP are addressed

above under section 3 entitled ``RACM (including RACT).'' The State,

while relying on the soil conservation measures of the FSA, has not

adopted these measures into the SIP or taken any credit for these

measures. Since these measures are federally mandated and will be

implemented by the U.S. Department of Agriculture, they are considered

to be federally enforceable. Thus, it is not necessary for the State to

adopt these measures into the SIP.

As discussed in section 3 above, there are State-wide regulations

that will also impact the emissions of PM-10 in the Lamar nonattainment

area. These regulations include Colorado Regulation No. 4, which

requires all wood stoves sold after July 1, 1991 to meet the emission

requirements of EPA's Standards of Performance for New Residential Wood

Heaters in 40 CFR 60.532(b), and Colorado Regulation No. 3, which

requires construction permits for new or modified stationary sources.

EPA previously reviewed Colorado Regulations No. 3 and 4 at the time

these regulations were approved by EPA as part of the SIP, and it was

determined that these regulations met the enforceability criteria of

the September 23, 1987 Potter Memorandum (see the TSD for information

on EPA approvals of these regulations).\6\

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

\6\Note that the current version of Colorado Regulation No. 3

approved by EPA does not meet all of the applicable requirements of

the amended Act. As discussed in footnote number 4, the State

submitted revisions to Regulation No. 3 in January of 1993 which are

being evaluated by EPA. EPA will act on that submittal in a separate

notice.

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

The State of Colorado has a program that will ensure that the

measures contained in the SIP are adequately enforced. The Colorado Air

Pollution Control Division (APCD) has the authority to implement and

enforce all emission limitations and control measures adopted by the

State, including the requirements of any emission control regulations,

the SIP, and any permit. The APCD has the authority to impose civil

penalties of up to $15,000 per day per violation, as well as criminal

penalties. Thus, EPA believes the State has adequate enforcement

capabilities to ensure compliance with the Lamar PM-10 SIP and the

State-wide regulations. The TSD contains further information on the

State-wide regulations, enforceability requirements, and a discussion

of the personnel and funding intended to support effective

implementation of the control measures.

8. Contingency Measures.

As provided in section 172(c)(9) of the Act, all moderate

nonattainment area SIPs that demonstrate attainment must include

contingency measures. See generally 57 FR 13510-13512 and 13543-13544.

These measures were to be submitted by November 15, 1993 for the

initial moderate nonattainment areas. Thus, the measures were due

separate from the requirements addressed in this notice. Contingency

measures should consist of other available measures that are not part

of the area's control strategy. These measures must take effect without

further action by the State or EPA, upon a determination by EPA that

the area has failed to make RFP or attain the PM-10 NAAQS by the

applicable statutory deadline. The Lamar SIP submittal addressed in

this notice did not include any contingency measures. The State

submitted the contingency measures for Lamar as a revision to the SIP

on December 9, 1993. EPA will act on the December 1993 submittal in a

separate notice.

III. Implications of This Action

The EPA is proposing to approve the plan revision submitted by

Colorado for the Lamar nonattainment area on May 27, 1993 to satisfy

those moderate area PM-10 SIP requirements due on November 15, 1991.

Among other things, the State of Colorado has adequately demonstrated

that the Lamar moderate PM-10 nonattainment area will attain the PM-10

NAAQS by December 31, 1994.

As noted, additional submittals for the initial moderate PM-10

nonattainment areas are due at later dates. The EPA will determine the

adequacy of any such submittal as appropriate.

IV. Request for Public Comments

The EPA is requesting comments on all aspects of this proposal. As

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

comments received by May 6, 1994.

V. Executive Order (EO) 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 notice will inform the general public of

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

(OMB) waived Table 2 and 3 SIP revisions (54 FR 2222) from the

requirements of section 3 of Executive Order 12291 for a period of two

years. The U.S. EPA has submitted a request for a permanent waiver for

Table 2 and 3 SIP revisions. The OMB has agreed to continue the

temporary 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.

VI. 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 economic impact on a substantial number of small entities.

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

enterprises, and government entities with jurisdiction over populations

of less than 50,000.

SIP approvals under section 110 and subchapter I, part D of the 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 small entities affected. Moreover, due

to the nature of the federal-state relationship under the Act,

preparation of a regulatory flexibility analysis would constitute

federal inquiry into the economic reasonableness of state action. The

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 (S.Ct. 1976);

42 U.S.C. section 7410(a)(2).

Nothing in this action should be construed as permitting or

allowing or establishing a precedent for any future request for

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

considered separately in light of specific technical, economic, and

environmental factors and in relation to relevant statutory and

regulatory requirements.

List of Subjects

40 CFR Part 52

Environmental protection, Air pollution control, Hydrocarbons,

Intergovernmental relations, Nitrogen dioxide, Particulate matter,

Reporting and recordkeeping requirements, Sulfur dioxide, Volatile

organic compounds.

40 CFR Part 81

Air pollution control, National parks, Wilderness areas.

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

Dated: March 18, 1994.

William P. Yellowtail,

Regional Administrator.

[FR Doc. 94-8228 Filed 4-5-94; 8:45 am]

BILLING CODE 6560-50-P