Approval and Promulgation of PMINF10 Implementation Plan for the Commonwealth of Puerto Rico

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[Region II Docket No. 126, PR3-1-6331, FRL-5030-4]

Approval and Promulgation of PM10 Implementation Plan for

the Commonwealth of Puerto Rico

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rulemaking.

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SUMMARY: The EPA proposes full approval of the State Implementation

Plan (SIP) submitted by the Commonwealth of Puerto Rico for the purpose

of attaining the National Ambient Air Quality Standards (NAAQS) for

fine particulate matter with an aerodynamic diameter less than or equal

to a nominal 10 micrometers (PM10). The SIP addresses sources

impacting the Municipality of Guaynabo, Puerto Rico which has been

designated nonattainment.

DATES: Comments must be received on or before the later of the

following two dates: either September 12, 1994 or 14 days after the

date of an EPA public meeting to discuss the proposal. The date, times

and place of this public meeting will be announced in Puerto Rico

shortly.

ADDRESSES: All comments should be addressed to:

Jeanne M. Fox, Regional Administrator, Environmental Protection Agency,

Region II Office, 26 Federal Plaza, New York, NY, 10278; or

Carl Soderberg, Director, Environmental Protection Agency, Region II,

Caribbean Field Office, Centro Europa Building, Suite 417, 1492 Ponce

De Leon Avenue, Stop 22, Santurce, Puerto Rico, 00909.

Copies of the state submittal are available at the following

addresses for inspection during normal business hours:

Environmental Protection Agency, Region II Office, Library, 26 Federal

Plaza, Room 402, New York, NY, 10278.

Environmental Protection Agency, Region II, Caribbean Field Office,

Centro Europa Building, Suite 417, 1492 Ponce De Leon Avenue, Stop 22,

Santurce, Puerto Rico, 00909.

Commonwealth of Puerto Rico, Environmental Quality Board, Banco

National Plaza, 8th Floor, 431 Ponce De Leon Avenue, Hato Rey, Puerto

Rico, 00917.

FOR FURTHER INFORMATION CONTACT:

William S. Baker, Chief, Air Programs Branch, Environmental Protection

Agency, Region II Office, 26 Federal Plaza, Room 1034A, New York, New

York, 10278, (212) 264-2517; or

Carl Soderberg, Director, Environmental Protection Agency, Region II,

Caribbean Field Office, Centro Europa Building, Suite 417, 1492 Ponce

De Leon Avenue, Stop 22, Santurce, Puerto Rico, 00909, (809) 729-6951.

SUPPLEMENTARY INFORMATION:

I. Background

The Clean Air Act, as amended in 1990 (the Act), requires all areas

that have measured a violation of the NAAQS be designated

nonattainment. The Municipality of Guaynabo, Puerto Rico was designated

nonattainment for PM10 and classified as moderate based on

violations measured in 1987 in the Municipality. The Act requires state

or territorial governments to revise the SIP for all areas that are

designated as nonattainment to ensure that the NAAQS will be attained.

Under the context of the Act, the Commonwealth of Puerto Rico is

regarded as a state. The reader should refer to the ``General

Preamble'' [see generally 57 FR 13498 (April 16, 1992) and 57 FR 18070

(April 28, 1992)] for a more detailed discussion of the designation of

PM10 nonattainment areas.

II. Clean Air Act Requirements for PM10 SIP's

The air quality planning requirements for areas designated

nonattainment for PM10 are set out in subparts 1 and 4 of Title I

of the Act. EPA intends to review SIP's and SIP revisions submitted

under Title I of the Act, including those state submittals addressing

moderate PM10 nonattainment areas according to the ``General

Preamble.'' Because EPA is describing the PM10 requirements here

only in broad terms, the reader should refer to the ``General

Preamble'' for a more detailed discussion of the PM10

requirements, and guidance on meeting those requirements.

States containing moderate PM10 nonattainment areas were

required to submit, among other things, the following elements by

November 15, 1991:

A. Regulations 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;

B. 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;

C. Quantitative milestones which are to be achieved every three

years and which demonstrate reasonable further progress (RFP) toward

attainment by December 31, 1994; and

D. Provisions to assure that the control requirements applicable to

major stationary sources of PM10 also apply to major stationary

sources of PM10 precursors except where the Administrator

determines that such sources do not contribute significantly to

PM10 levels which exceed the NAAQS in the nonattainment area

(sections 172(c), 188, and 189.)

There are requirements for a New Source Review (NSR) permit program

and contingency measures that are due at a later date:

E. States with a moderate PM10 nonattainment area were

required to submit a NSR permit program SIP revision for the

construction and operation of new and modified major stationary sources

of PM10 by June 30, 1992 [section 189 (a)(2)]. The specific NSR

requirements for moderate PM10 nonattainment areas are:

1. Definition of the term ``major stationary source'' that reflects

thresholds of 100 tons per year (tpy) for PM10 and, presumptively,

100 tpy for each PM10 precursor for determination of whether a

source is subject to Part D requirements as a major source;

2. Provisions to ensure that new or modified major stationary

sources obtain emission offsets at an offset ratio of at least one to

one;

3. Requirements applicable to major sources of PM10 are also

applicable to major sources of PM10 precursors, except where EPA

determines that the sources of PM10 precursors do not contribute

significantly to PM10 levels which exceed the PM10 NAAQS in

the area. The EPA generally considers sulfur dioxide (SO2),

nitrogen oxides (NOX), and volatile organic compounds (VOC) to be

PM10 precursors for NSR purposes; and

4. Provisions to ensure that the significance threshold for a

modification to be major, and therefore subject to the section 173

permit requirements, is 15 tpy for PM10 and, presumptively, 15 tpy

for each PM10 precursor.

F. States 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 PM10 NAAQS by the applicable statutory deadline. This

requirement is described in section 172(c)(9) of the Act and 57 FR

13543-13544.

General requirements for implementation plans are contained in

section 110 of the Act and sets out provisions governing EPA's review

of SIP submittals (see 57 FR 13565-13566). 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.1

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. 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].

EPA's completeness criteria for SIP submittals are set out at Title 40

Code of Federal Regulation (CFR) Part 51, Appendix V (1991), as amended

by 57 FR 42216 (August 26, 1991).

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\1\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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III. Analysis of Puerto Rico's SIP Submission

For a more detailed discussion of Puerto Rico's submittal and EPA's

proposed action on the submittal, the reader should refer to the

Technical Support Document developed for this proposed action and found

at the previously mentioned addresses.

A. Administrative Requirements

The Commonwealth of Puerto Rico held a public hearing on October

15, 1993 to accept public comments on the implementation plan for the

Municipality of Guaynabo PM10 nonattainment area. Following the

public hearing the plan was adopted by Puerto Rico and signed by the

Secretary of State on March 2, 1994. On November 14, 1993, the plan was

submitted to EPA as a revision to the SIP. The submittal was

supplemented with administrative documents on March 18, 1994 and March

30, 1994. The SIP revision submitted on November 14, 1993 and

supplemented on March 18, 1994 and March 30, 1994 was reviewed by EPA

to determine completeness in accordance with the completeness criteria

set out at 40 CFR 51, and found to be complete.

Previously, the Governor of Puerto Rico was notified on December

16, 1991 by the EPA Regional Administrator that Puerto Rico had not

submitted the PM10 SIP requirements due on November 15, 1991. This

action formally started both an 18-month Sanction clock and a 24-month

Federal Implementation Plan (FIP) clock. In a January 15, 1993 letter,

the Governor was notified that another 18-month Sanction clock and 24-

month FIP clock, for the failure to submit a permit program for the NSR

requirements by June 30, 1992, had begun. Since the November 14, 1993

submittal was found to be complete, the findings made on December 16,

1991 and January 15, 1993 of non-submittal have been corrected and no

sanctions will be imposed. In this action, EPA is proposing to approve

the SIP revision submitted to EPA on November 14, 1993 and supplemented

on March 18, 1994 and March 30, 1994.

B. Emissions Inventory

Section 172(c)(3) of the Act requires that nonattainment plan

provisions include a comprehensive, accurate, and 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 are necessary

to an area's attainment demonstration, the emissions inventories must

be received with the submission (see 57 FR 13539).

Puerto Rico submitted an emissions inventory for base year 1990.

The base year inventory identified area sources as the primary cause of

PM10 nonattainment contributing approximately 79 percent of the

total emissions during the time the violations were recorded.

Additional contributing sources included point sources (19 percent),

microinventory sources including fugitive dust sources (one percent),

and marine vessels (one percent).

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.2

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\2\EPA issued guidance on PM10 emissions inventories prior

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

1987 PM10 SIP Development Guideline. The guidance provided in

this document appears to be consistent with the Act.

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C. RACM (Including RACT)

As previously noted, moderate PM10 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)]. 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).

Puerto Rico submitted provisions to assure the implementation of

RACM (including RACT) by December 10, 1993. The SIP contains

enforceable commitments by the Puerto Rico Environmental Quality Board

(PREQB) to achieve various RACM requirements in the regulations as well

as through Memoranda of Understanding (MOU). The PREQB has signed MOU's

with various entities to include details of how the various RACM

requirements will be implemented. Further discussion on the MOU's is

included in the enforceability section `G'. The three RACM's contained

in the SIP address measures to control emissions from urban fugitive

dust sources such as re-entrained road dust from paved roads, unpaved

roads and parking lots, and windblown dust from construction sites and

other areas;

1. The SIP determined that an efficiency of 25 percent was

reasonable in controlling emissions of fugitive dust from paved roads.

2. The SIP determined that a control effectiveness of 70 percent

was reasonable in controlling emissions of fugitive dust from unpaved

roads, based on the use of chemical stabilization. Also, a control

effectiveness of 90 percent is used for unpaved roads and parking lots

located at industrial facilities in the Municipality of Guaynabo.

3. Due to uncertainties in quantifying the emission reduction

benefit for construction sites and other areas where land is subject to

wind erosion, no credit was taken in the attainment demonstration for

emission reductions. However, controlling these sources using Puerto

Rico's SIP measures will further assure attainment of the NAAQS in the

Municipality of Guaynabo.

In addition to the control measures for fugitive dust sources, five

point source categories were identified as contributing to the

PM10 nonattainment problem in the Municipality of Guaynabo. RACT

for these source categories are:

1. Electric Utilities (greater than 25 megawatts of generating

capacity) are limited to the use of 1.5 percent sulfur in No. 6 fuel

oil;

2. Petroleum Refineries are limited to the use of 1.0 percent

sulfur in No. 6 fuel oil;

3. Grain Handling facilities must install control equipment that is

99.5 percent efficient; prohibit clam unloading of barges; require all

material handling operations including truck loading/unloading, and

ship unloading to take place in fully enclosed rooms and vented to a

control device; and implement a street cleaning program for all yard

activities associated with vehicular activities;

4. Asphalt Blowing facilities must install control equipment that

controls 90 percent of the emissions; and

5. Quarries/Rock Crushing operations must utilize water to suppress

dust thus achieving a 70 percent reduction in emissions.

The RACT regulations will apply to sources in these source

categories which are located in or have an impact on the Municipality

of Guaynabo. The following table includes the estimated PM10

emissions before and after controls for the source categories

previously mentioned.

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

Base year emissions RACT emissions

(tpy) (tpy) Emission

Source category ------------------------------------------ reductions

Actual Allowable Actual Allowable (tpy)

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Electric Utilities 2196.9 5814.2 2079.0 4908.7 905.5

Petroleum

Refineries....... 42.1 167.8 42.1 167.8 30.0

Grain Handling.... 214.3 256.0 25.0 33.0 4223.0

Asphalt Blowing... 59.5 81.8 6.0 8.2 73.6

Quarries/Rock

Crushing

Operation........ 74.6 74.6 74.6 74.6 30.0

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

Total....... 2587.4 6394.4 2226.7 5192.3 1202.1

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3The SIP requires that RACT be applied to these source categories, but

the analysis had uncertainties in the precise calculation of the

emission reduction benefit. Puerto Rico has chosen, in essence, no

credit to be taken towards attainment for the application of RACT on

these sources and instead that they act as additional measures to make

certain the area attains the NAAQS.

4The emission reductions presented in the table also reflect the

reductions from installing control equipment as well as paving the

truck haul roads at the grain handling facilities and other control

measures.

Puerto Rico commits to implementing the control measures (RACM and

RACT) by December 10, 1993. Control of the point source categories is

expected to result in an estimated emission reduction in PM10 of

1,202.1 tpy in the area. EPA has reviewed Puerto Rico's explanation and

associated documentation and concluded that it adequately justifies its

choice of control measures to be implemented. The implementation of

Puerto Rico's PM10 nonattainment plan control strategy will result

in the attainment of the PM10 NAAQS by December 31, 1994. By this

notice, EPA is proposing to approve the control strategy comprising

RACM including RACT.

D. Demonstration of Attainment

As previously noted, moderate PM10 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).

PREQB performed an attainment demonstration using the Industrial

Source Complex (ISC2) dispersion model and five years of National

Weather Service meteorological data. This demonstration indicates the

NAAQS for PM10 will be attained by December 31, 1994 in the

Municipality of Guaynabo and maintained throughout the future to year

1999. The demonstration predicted the highest 24-hour average

concentration by the attainment date of December 31, 1994 will be 111.3

g/m3, compared to the 24-hour PM10 NAAQS of 150

g/m3. The peak annual concentration predicted by the

model for the attainment year is 48.9 g/m3, compared to

the annual PM10 NAAQS of 50 g/m3. The demonstration

also showed that the PM10 NAAQS will be maintained in future years

through the year 1999.

E. New Source Review PM10 Permit Program

The general statutory permit requirements for moderate PM10

nonattainment areas are contained in section 173 and in subpart 4 of

Part D of the Act. For moderate PM10 nonattainment areas, states

must adopt the appropriate major source threshold, offset ratio,

significance level for modifications, and provisions for PM10

precursors. The following summarizes how Puerto Rico's SIP submittal

addresses the NSR requirements.

1. Puerto Rico has established a major source threshold of 100 tpy,

a minimum offset ratio of one to one, and a modification significance

level of 15 tpy. These provisions meet the minimum federal requirements

and are, therefore, approvable.

2. Puerto Rico has satisfied the requirement to demonstrate that

the control requirements which are applicable to major stationary

sources of PM10, should also apply to major stationary sources of

PM10 precursors, such as SO2, VOC and NOX. However, such

requirements will not apply where the EPA Administrator and the Board

determine that such sources of PM10 precursors do not

significantly contribute to PM10 levels which exceed the PM10

ambient standards.

3. The provisions to ensure the lifting of construction bans

previously imposed on states which did not have an approved

nonattainment NSR SIP are not applicable to Puerto Rico since it did

not have a construction ban.

4. The provisions to assure that calculation of emissions offsets,

as required by section 173(a)(1)(A), are based on the same emissions

baseline used in the demonstration of RFP are already contained in

Puerto Rico's existing regulations.

5. Puerto Rico's Rule 203 provides that a permit to construct or

modify a source may be granted for a proposed new major source or major

modification of an existing major source only if the applicant has

received a valid location approval. Rule 201 provides that a location

approval may be granted only if an emission offset is provided and the

``emission reductions must [be] based in actual emissions and federally

enforceable, through a permit condition made to the existing source, by

the time the new or modified source commences operation.'' EPA

interprets these rules to require an applicant for a new major source

or a major modification to an existing major source to secure federally

enforceable emission reductions before a permit to construct or modify

is granted, and to require that such emission reductions be federally

enforceable and in effect by the time the new or modified source

commences operation. That is, the permit condition for emission

reductions by the existing source will not have an effective date

beyond the date when the new or modified source commences operation.

EPA therefore proposes approval of these rules as satisfying

requirements in section 173(a & c).

6. The provisions to assure that emissions increases from new or

modified major stationary sources are offset by real reductions in

actual emissions as required by section 173(c)(1) are contained in the

revised regulations, and are therefore approvable.

7. The provisions to prevent emissions reductions otherwise

required by the Act from being credited for purposes of satisfying the

Part D offset requirements are contained in the regulations, and are

therefore approvable.

8. Provisions that, as a prerequisite to issuing any part D permit,

require an analysis of alternative sites, sizes, production processes,

and environmental control techniques for proposed sources that

demonstrates that the benefits of the proposed source significantly

outweigh the environmental and social costs imposed as a result of its

location, construction, or modification, are included in the revised

regulation, and are therefore approvable.

9. Puerto Rico has included a provision, in accordance with section

173(d) of the Act, for supplying information from nonattainment NSR

permits to EPA's RACT/BACT/LAER clearinghouse. This provision is

therefore approvable.

EPA is proposing to approve the PM10 NSR permit program SIP

revision.

F. Quantitative Milestones and RFP

The moderate PM10 nonattainment area plan revisions

demonstrating attainment must contain quantitative milestones which are

to be achieved every three years until the area is redesignated

attainment and which demonstrate RFP 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.

For moderate PM10 nonattainment areas, the emissions

reductions progress made between the SIP submittal due date of November

15, 1991 and the attainment date of December 31, 1994 will satisfy the

first quantitative milestone. The deminimis timing differential makes

it administratively impracticable to require separate milestone and

attainment demonstrations. Thus, EPA's policy is to deem that the

emissions reductions progress made between the SIP submittal due date

and the attainment date will satisfy the quantitative milestone

requirement for these areas (see 57 FR 13539).

G. Enforceability

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) and 57 FR

13556). The EPA's criteria addressing the enforceability of SIP's and

SIP revisions are 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). Moderate PM10 nonattainment

area plan provisions must also contain a program which 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

under the section headed ``RACM (including RACT).'' These control

measures apply to the types of activities identified in that

discussion. The SIP provides that only specific sources in the

PM10 nonattainment area and/or that significantly impact the

nonattainment area will be subject to the applicable control measures.

Several minor sources were excluded in the control strategy because

they do not contribute significantly to the modeled exceedances of the

NAAQS.

Consistent with the attainment demonstration described above, the

SIP requires that all affected stationary sources must be in full

compliance with the applicable RACT requirements by December 10, 1993.

However, if a physical alteration of the stationary source is necessary

to achieve compliance, the SIP requires that construction of the

alteration must commence by February 15, 1994, and must be completed by

November 30, 1994. Compliance with these RACT requirements must be

demonstrated using the applicable EPA Reference Test Methods. Puerto

Rico has an enforcement program that will ensure that these RACT

requirements are adequately enforced. There are civil penalties for

noncompliance with the Regulation containing these RACT requirements.

RACT for stationary point sources is also enforced by PREQB through

federally enforceable permit conditions.

In addition to the RACT requirements for stationary sources, the

SIP contains enforceable commitments by PREQB to achieve various RACM

requirements. To implement these measures, PREQB has signed an MOU with

the Puerto Rico Department of Transportation, the Puerto Rico Electric

Power Authority, the Municipality of Guaynabo, and the Port Authority

that contain details for how each of these entities will meet these

RACM commitments. The commitments to implement the RACM requirements

are in the SIP itself, and thus are enforceable as requirements of the

SIP. In addition, the MOU, having gone through public review and

comment, will be incorporated into the SIP by reference, and are

effective as of the date each was signed. The attainment demonstration,

which shows attainment of the PM10 NAAQS by December 31, 1994,

uses emissions reductions based on some of these RACM measures, and

thus EPA expects them to be implemented by that date. Once incorporated

into the approved SIP, the requirements of the MOU may not be changed

except by a revision to the SIP submitted to and approved by EPA.

Puerto Rico's revisions to the regulations include a new definition

for ``PM10'' in Rule 102. Although test methods are not contained

in Puerto Rico's definition of ``PM10'' as they are in 40 CFR

51.100 (qq), EPA proposes to approve Puerto Rico's definition of

``PM10,'' since the relevant test methods are found in other

provisions of the regulations.

H. Contingency Measures

As provided in section 172(c)(9) of the Act, all moderate PM10

nonattainment area SIP's that demonstrate attainment must include

contingency measures (see generally 57 FR 13543-44). These measures

must be submitted by November 15, 1993 for the moderate PM10

nonattainment areas. 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 PM10 NAAQS by the applicable statutory deadline. The

Municipality of Guaynabo PM10 nonattainment area SIP contains the

following six contingency measures and are included in Rule 423(D):

1. Puerto Rico Department of Transportation shall collect data on

silt content and dust loadings for highways in the Municipality of

Guaynabo for better estimating PM10 emissions following EPA's

``Compilation of Air Pollution Emission Factors'' (AP-42) procedures.

2. The Municipality of Guaynabo shall require vegetation, chemical

stabilization, or other abatement of wind erodible soils.

3. Diesel fuel oil with a sulfur in fuel less than 0.3 percent

shall be used by all vessels operating in San Juan Bay.

4. No visible emissions from any vessel shall be permitted in the

San Juan Bay except as provided in Rule 403 of the regulations.

5. The Port Authority shall implement a street cleaning program or

other program to prevent dust from collecting on paved surfaces in

their jurisdiction.

6. The Municipality of San Juan must revise the dust and fire

abatement programs at its sanitary landfill in order to establish

additional pollution control strategies.

The SIP provides that each of these measures can take effect

without further action by Puerto Rico or EPA should EPA determine that

the Municipality of Guaynabo PM10 nonattainment area has failed to

achieve RFP or to attain the PM10 NAAQS by December 31, 1994.

After review of the contingency measures described above, EPA is

proposing to approve the Municipality of Guaynabo PM10

nonattainment area contingency measures.

I. PM10 Precursors

The Act states that ``control requirements applicable to major

stationary sources of PM10 must also apply to major stationary

sources of PM10 precursors except where the Administrator

determines that such sources do not contribute significantly to

PM10 levels which exceed the NAAQS in the area.'' Based on filter

analyses of the Guaynabo nonattainment area, the relatively minor

contribution of precursors to overall nonattainment, and the

effectiveness of the state's RACT/RACM strategies, EPA has determined

that no direct controls of PM10 precursors are needed for

attainment. Nonetheless, Puerto Rico has chosen to include a provision

for NSR purposes wherein the requirements for PM10 precursors

apply unless EPA and PREQB determine otherwise.

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.

IV. Summary

EPA is proposing to approve the plan revision submitted on November

14, 1993 by Puerto Rico for the Municipality of Guaynabo PM10

nonattainment area. Specifically, EPA is proposing to approve the

emissions inventory, the control strategy including RACM and RACT, the

demonstration that the Municipality of Guaynabo PM10 nonattainment

area will attain the PM10 NAAQS by December 31, 1994 and maintain

the PM10 NAAQS through 1999, the NSR permit provisions and the

contingency measures. EPA determined that PM10 precursor controls

are not needed for attainment. EPA proposes to approve this SIP

submittal in relation to its satisfying all Act requirements, therefore

addressing the findings made by EPA on December 16, 1991 and January

15, 1993.

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

will consider all comments received before taking final action.

V. Miscellaneous

Nothing in this proposed rule 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.

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 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 any small entities affected. Moveover,

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

Act forbids EPA to base its actions concerning SIP's on such grounds.

Union Electric Co. v US EPA, 427 US 246, 256-66 (S.Ct. 1976); 42 U.S.C.

7410(a)(2).

This proposed rule 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 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 EPA has submitted a request for a permanent

waiver for Table 2 and 3 SIP revisions. The Office of Management and

Budget has agreed to continue the temporary wavier 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, Hydrocarbons,

Incorporation by reference, Intergovernmental relations, Nitrogen

dioxide, Particulate matter, Reporting and recordkeeping requirements,

Sulfur oxides, Volatile organic compounds.

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

Dated: July 21, 1994.

Jeanne M. Fox,

Regional Administrator.

[FR Doc. 94-19641 Filed 8-10-94; 8:45 am]

BILLING CODE 6560-50-P