40 CFR Part 52

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[WA3-1-5479a; FRL-4997-6]

Approval and Promulgation of State Implementation Plans: Washington

AGENCY: Environmental Protection Agency.

ACTION: Final rule.

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SUMMARY: In this action, Environmental Protection Agency (EPA)

conditionally approves the State implementation plan (SIP) revisions

submitted by the State of Washington for the purpose of bringing about

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 implementation plan was submitted

by the State to satisfy certain Federal Clean Air Act requirements for

an approvable moderate nonattainment area PM-10 SIP for Seattle,

Washington due on November 15, 1991.

DATES: This final rule will be effective on August 22, 1994, unless

adverse or critical comments are received by July 25, 1994. If the

effective date is delayed, timely notice will be published in the

Federal Register.

ADDRESSES: Written comments should be addressed to: Montel Livingston,

SIP Manager, EPA, Air Programs Branch (AT-082), 1200 Sixth Avenue,

Seattle, Washington 98101.

Documents which are incorporated by reference are available for

public inspection at the Air and Radiation Docket and Information

Center, EPA, 401 M Street, SW., Washington, DC 20460. Copies of

material submitted to EPA may be examined during normal business hours

at the following locations: EPA, Air Programs Branch, 1200 Sixth Avenue

(AT-082), Seattle, Washington 98101, and the State of Washington

Department of Ecology, 4450 Third Ave. SE., Lacey, Washington 98504.

FOR FURTHER INFORMATION CONTACT: George Lauderdale, Air Programs Branch

(AT-082), EPA, 1200 Sixth Avenue, Seattle, Washington 98101, (206) 553-

6511.

SUPPLEMENTARY INFORMATION:

I. Background

The Seattle, Washington, area was designated nonattainment for PM-

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

the Clean Air Act, by operation of law upon enactment of the Clean Air

Act Amendments of 1990.1 See 56 FR 56694 (Nov. 6, 1991) (official

designation codified at 40 CFR 81.348). The air quality planning

requirements for moderate PM-10 nonattainment areas are set out in

subparts 1 and 4 of part D, title I of the Act.2 The EPA has

issued a ``General Preamble'' describing EPA's preliminary views on how

EPA intends to review SIP's 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 thisproposal and the supporting

rationale. In this rulemaking action on the Washington moderate PM-10

SIP for the Seattle nonattainment area, EPA applies its

interpretations, taking into consideration the specific factual issues

presented. Additional information supporting EPA's action on this

particular area is available for inspection at the address indicated

above.

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\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.

\2\Subpart 1 contains provisions applicable to nonattainment

areas generally and subpart 4 contains provisions specifically

applicable to PM-10 nonattainment areas. At times, subpart 1 and

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

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

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

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Those States containing initial moderate PM-10 nonattainment areas

(those areas designated nonattainment under section 107(d)(4)(B)) 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 were to 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 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). Section 110(k)(4) of

the Act authorizes EPA to approve a plan revision based on a commitment

by the State to adopt specific enforceable measures by a date certain,

but not later than one year after the date of approval of the plan

revision. EPA would then assess the approvability of the submittal

after the State fulfilled its commitment. However, if the State fails

to comply with its commitment, section 110(k)(4) provides that a

conditional approval shall be treated as a disapproval. The conditional

approval would become a disapproval upon notification of the State by

letter. EPA would subsequently publish a document in the Federal

Register announcing such action. If the conditional approval is

converted to a disapproval, the sanctions clock under section 179(a) of

the Act and the Federal implementation plan clock under section

110(c)(1) of the Act will begin.

In this action, EPA is granting conditional approval of the plan

revisions submitted to EPA for Seattle, Washington, on November 5,

1990, December 27, 1990, November 15, 1991, and May 11, 1994 (hereafter

generally referred to as a single submittal). EPA conditionally

approves the submittal because it meets many of the applicable

requirements of the Act and contains a commitment from the State to

adopt specific enforceable measures on or before January 1, 1995, to

address remaining applicable requirements of the Act. EPA approves the

exclusion from precursor controls as described in part II. 5 below. In

addition, EPA approves certain control measures contained in the

Seattle plan submittals which generally strengthen the plan.

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.3 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. 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 six

months after receipt of the submission.

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\3\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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The State of Washington Department of Ecology (WDOE) and the Puget

Sound Air Pollution Control Agency (PSAPCA) held a joint public hearing

to receive public comment on the original Seattle implementation plan

on December 8, 1988. WDOE adopted the implementation plan for the area

on November 3, 1990 and the plan was submitted to EPA on November 5,

1990. The plan was subsequently revised on December 27, 1990, November

15, 1991, and May 11, 1994. WDOE held appropriate public hearings prior

to submittal of each of the SIP revisions to entertain public comment.

The SIP submittal was reviewed by EPA to determine completeness in

accordance with the completeness criteria set out at 40 CFR part 51,

appendix V. A letter dated February 13, 1992, was forwarded to the WDOE

indicating the completeness of the submittal and the next steps to be

taken in the review process.

2. PM-10 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. Because the submission of the emissions inventory

is a necessary adjunct to an area's attainment demonstration (or

demonstration that the area cannot practicably attain) the emissions

inventory must be received with the demonstration (see 57 FR 13539).

WDOE submitted an emissions inventory of estimated actual emissions

for the base year of 1986 and the attainment year of 1991. The annual

and 24-hour emission inventories identified four major source

categories contributing to particulate matter concentrations in the

valley. These are, in descending order of greatest contribution,

vehicle resuspended dust (48%); industrial stack emissions (30%), motor

vehicle emissions (9%) and industrial fugitive emissions (7%).

Residential wood combustion is a relatively smaller source of PM-10

within the nonattainment area boundaries. However, the plan does

include control measures for residential wood combustion because there

is a large population of woodstoves and fireplaces adjacent to the

nonattainment area, and throughout the metropolitan area. WDOE has

determined all other sources to be insignificant within the

nonattainment area.

The emissions inventory estimating actual emissions generally

appears to be accurate and comprehensive, and provides a sufficient

basis for determining the technical adequacy of the attainment

demonstration for this area consistent with the requirements of section

172(c)(3) of the Clean Air Act.4 An important attainment year

emission inventory issue, relating to the attainment demonstration, and

other requirements, is the use of actual instead of allowable emission

estimates for projecting attainment. This issue will be discussed in

detail under the demonstration section of this document. For further

information the reader is referred to the Technical Support Document

(TSD) corresponding with this action, which is available at the EPA

address indicated above.

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\4\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 Act.

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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)). 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).

The Seattle emission inventory identified industrial fugitive

emissions and resuspended road dust as the significant contributors of

fugitive dust emissions. PSAPCA's fugitive dust regulation (Regulation

I, section 9.15) was designed to reduce fugitive dust from commercial

and industrial activities and also to reduce dust emissions from paved

and unpaved roads and parking lots.

PSAPCA requires ``Best Available Control Technology (BACT)'' under

section 9.15 for all fugitive emissions from all incinerators, boilers,

manufacturing equipment and air pollution control equipment. The

Seattle attainment plan lists and documents emission reductions from

several major facilities that were required to add PM-10 controls as

the result of PSAPCA's application of section 9.15. EPA accepts the

emission reductions claimed from this control measure as reasonable.

Since it is generally impractical to source test fugitive emission

sources, a SIP must rely on calculated emission estimates, and control

efficiency estimates, to arrive at emission reduction estimates.

PSAPCA applies the same section 9.15 BACT provisions to dust

emissions from both private and public paved and unpaved roads. In

addition, all private roadways adjoining paved public roads and all

commercial properties with access points abutting paved public roads in

the Seattle nonattainment area are required to implement BACT to

stabilize vehicular entrances and exits. The control measure

appropriately prioritized preventing material deposition over

mitigating measures after deposition. The plan uses an overall emission

reduction credit of 37% from resuspended road dust. EPA accepts this

estimate as reasonable.

Another source of PM-10 pollution is residential wood combustion.

PSAPCA initiated a voluntary woodsmoke curtailment program throughout

its four county jurisdictional area, including Seattle, in the winter

of 1987-88. The program changed to mandatory curtailment beginning with

the 1988-89 heating season, pursuant to WAC 173-433 and the PSAPCA

Regulation I, Article 13. The curtailment program is a two stage plan.

At Stage I, which is imposed when ambient PM-10 levels reach 75

g/m3, the use of uncertified stoves and fireplaces are

banned. At Stage II, imposed when PM-10 levels reach 105 g/

m3, all wood heating (fireplaces, certified and uncertified

woodstoves) is prohibited. The program exempts homes with no other

source of heat. WDOE and PSAPCA regulations contain additional

controls, including the prohibition of all fuels except dry, seasoned

wood in woodheating devices. Plume opacity for woodheating devices is

limited to 20%, with brief allowances for fire starting and stoking.

PSAPCA serves as the primary enforcement agency for the curtailment and

opacity portions of the control program. Both PSAPCA and WDOE

administer public education programs targeted at residential wood

burning. Throughout the State, WDOE also enforces a ban on the sale of

uncertified woodstoves.

The strength and depth of the legislated woodsmoke program, and the

size and historical effectiveness of the agencies involved,

demonstrates to EPA's satisfaction that the Seattle area is achieving a

sufficient compliance rate to justify the 70% emission reduction

credit. In addition, Ecology expects the implementation of part of the

King County Board of Health (KCBH) Regulation 70 (Title 16 of the Code

of the King County Board of Health) to further reduce daily woodstove

emissions; this will assist in maintaining the standard through 1994.

The KCBH requirement that uncertified woodstoves be removed on sale of

a home is estimated to reduce background particulates and result in a

36 kg/day reduction in the nonattainment area. EPA accepts this

estimate as reasonable and notes that Ecology did not seek credit for

several other control measures contained in the King County regulation

which could reasonably be expected to result in additional PM-10

emission reductions. A more detailed analysis of the Washington

woodsmoke curtailment plan and other residential wood combustion

measures is contained in the TSD.

The attainment plan contains a control measure directed at

prescribed burning even though the emission inventory for the

nonattainment area does not indicate prescribed burning as a major

source. The 1991 Clean Air Washington Act added additional restrictions

to general outdoor and prescribed burning in the Seattle nonattainment

area. In response to the new provision of the Act, PSAPCA banned all

outdoor burning in the Federal Aid Urban Area (much larger than the

nonattainment area) effective September 1, 1992. This strengthened

PSAPCA's previous regulation restricting open burning by expanding the

area covered. The November 15, 1991, submittal contains a 24 kg/day

emission credit that reduces the background concentrations for the

Seattle nonattainment area. EPA considers the estimation reasonable and

approves the reduction credit.

Ecology proposed in the November 15, 1991, submittal an emission

reduction credit of 85 kg/day for implementation of a Washington State

law requiring major employers to reduce single occupant vehicle

commuting by 15 percent by January 1, 1995. Inthe April 1992

supplement, Ecology revised the emission estimate to 14 kg/day based on

more recent data.

EPA approves the 14 kg/day credit for the control measure as a

reasonable estimate of the impact of the law. This technical conclusion

is based on the information provided in the April 1992 ``Supplement

Addendum.'' EPA has information that the law is being implemented in

the Seattle nonattainment area. Ecology submitted RWC 70.94, 521-551,

authorizing a Transportation Demand Management program, on November 13,

1992 as part of a carbon monoxide SIP revision. EPA approves the

measure as part of the Seattle PM-10 attainment plan.

Ecology began implementing a new program on July 1, 1993, to

inspect diesel fueled vehicles. The program includes a simple pass/fail

opacity test. The November 15, 1991, SIP submittal estimates an

emission reduction of 47 kg/day from implementation of the program. In

the April 1992 supplement, based on more recent data, the estimate was

revised to 50 kg/day. EPA approves the 50 kg/day emission reduction

credit as reasonable. The measure was submitted as a ``contingency

measure'' in the November 15, 1991, SIP revision. The measure is more

appropriately a control measure because it is relied on to maintain air

quality below the standards through 1994. The April 1992 supplement

from Ecology agrees with this view. The regulation was submitted with a

1992 carbon monoxide SIP revision and EPA proposes to approve those

portions of the regulation which apply to the diesel inspection and

maintenance program.

The November 15, 1991, SIP submittal contained emission reduction

credits from the implementation of the Federal requirement reducing

sulfur content in diesel fuel. The credit taken by Ecology is the same

as the credit estimated by EPA, 7.5%. This credit translates to

emission reductions of 19 kg/day. EPA accepts this credit as a

reasonable estimate of emission reductions from the implementation of

the Federal requirement. As with the diesel I/M program, the control

measure was originally submitted as a ``contingency measure,'' when the

measure is really an additional control measure necessary to maintain

the standards through 1994. Since the measure is federally required,

Ecology does not need to include another legally enforceable regulation

in the SIP.

The stack emissions in the Seattle nonattainment area were being

controlled prior to the development of the PM-10 plan to a degree

PSAPCA and Ecology consider reasonably available control technology.

PSAPCA did review and modify several regulations to generally

strengthen control of stack sources but did not request any additional

emission reduction credit. In 1988, additional wording was added to

PSAPCA regulations to emphasize operation and maintenance of control

equipment and several emission standards were strengthened. Control

equipment for stack sources in the Seattle area include traditional

electrostatic precipitators, baghouses, etc. There are 10 stack sources

in the Seattle area that were included in the emission inventory. The

sources ranged in size from 119 tons per year (controlled) to two tons

per year (controlled). The plan requests no emission reduction credit

from any additional control of stack emissions. EPA accepts this

determination.

Where sources of PM-10 contribute insignificantly to the PM-10

problem in the area, EPA's policy is that it would be unreasonable (and

would not constitute RACM) to require the implementation of potentially

available control measures. 57 FR 13540. Further, EPA has indicated

that for some sources in areas which demonstrate attainment, RACM does

not require the implementation of otherwise available control measures

that are not ``reasonably'' available because their implementation

would not expedite attainment (See 57 FR 13543). In the Seattle

situation, EPA believes the significant sources, as well as several

less significant sources, of PM-10 in the area have been reasonably

controlled. Thus, EPA believes it would be unreasonable to require

other de minimis sources of PM-10 in the area to implement potentially

available control measures or technology. Further, EPA believes

implementation of such additional controls in this area would not

expedite attainment.

A more detailed discussion of the individual source contributions,

their associated control measures and an explanation as to why certain

available control measures were not implemented, can be found in the

TSD. EPA has reviewed the State's explanation and associated

documentation and concludes that it adequately justifies the control

measures to be implemented. As addressed in more detail in part II.4.

below, not all of the emission reductions necessary to assure

expeditious attainment of the PM-10 NAAQS have been converted to

enforceable emission limitations. Thus, EPA is approving all control

measures for their general SIP strengthening effect. The only exception

is that EPA conditionally approves the emission estimates used for the

stack sources. Ecology will submit to EPA by January 1, 1995, legally

enforceable emission limits for the significant stack sources in

Seattle. This conditional approval is discussed further in the section

below.

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). The General Preamble sets out EPA's guidance on the use of

modeling for moderate area attainment demonstrations (57 FR 13539).

Alternatively, if the State does not submit a demonstration of

attainment, the State must show that attainment by December 31, 1994 is

impracticable (section 189(a)(1)(B)(ii).

PSAPCA in conjunction with WDOE conducted an attainment

demonstration in the Seattle, Washington, nonattainment area. The

dispersion modeling conducted employed WYNDvalley in combination with

RAM. WYNDvalley is a non-guideline dispersion model that the EPA

Regional Meteorologist approved for use in Seattle due to very low wind

speeds occurring during periods of historical exceedances. RAM, which

is a guideline model, was used to model emissions from stack sources,

while WYNDvalley was used for all other sources. Outputs from both

models were then combined for each grid cell to yield a cumulative

impact estimate.

PSAPCA employed this combination of models because RAM is believed

to more accurately represent dispersion patterns at the greater release

heights of the valley's industrial stacks, though its predictions of

ambient concentrations are less reliable during periods of air

stagnation. WYNDvalley, on the other hand, was designed for use in

stagnant conditions, but fails to predict the impact of those emissions

that may rise above the height of the inversion layer. Receptor

modeling was not used in the attainment demonstration.

A major problem with the attainment demonstration is the attainment

year emission inventory used for point (stack) sources. The inventory

was based on actual emission estimates. EPA's Guideline on Air Quality

Models (Revised, July 1986) generally requires use of allowable

emissions in inventories for the purposes of modeling attainment of the

NAAQS (see also section 110(a)(2)(K) of the Act). The requirement takes

into consideration possible increases from existing sources allowed by

their permits, registrations, or other regulatory mechanisms. Ecology

and PSAPCA, based on comments from EPA, were not able to demonstrate

that all point source emissions in the nonattainment area would be

unable to increase significantly above actual levels. Consequently,

there is no objective assurance, or legally enforceable mechanism in

place, to restrict a point source from emitting above the estimated

actual rate, should the source have the physical capacity. Therefore,

the current SIP cannot assure that the NAAQS will be protected in the

Seattle nonattainment area. Although Seattle has accumulated five years

of data with no exceedances of the NAAQS, there are no legal limits in

place to prevent future increases from a few industrial facilities that

could consequently threaten attainment of the NAAQS. Ecology submitted

on May 11, 1994, a request for conditional approval of the Seattle

nonattainment plan based on a commitment to reconcile the actual/

allowable issue. Ecology's commitment is based on PSAPCA's schedule to

issue regulatory orders to appropriate point sources within the

nonattainment area that will restrict emissions at or below the

``actual'' emission estimates used in the attainment demonstration.

The November 15, 1991, SIP revision contained a three year

maintenance demonstration that was based on an outdated emission

inventory. After EPA notified Ecology of this error, supplemental

information was submitted on April 29, 1992. The April 1992,

``Supplemental Addendum'', although not a formal SIP revision, provides

a replacement three year maintenance demonstration, which includes the

expected growth in emissions from 1991 to 1994, and describes the

control measures that Ecology expects will offset the increased

emissions.

Technical analysis provided in both the November 1991, and April

1992, submittals utilized proportional modeling to perform the air

quality modeling to demonstrate maintenance to the year 1994. In the

Seattle situation, Ecology used dispersion modeling for the attainment

demonstration and proportional modeling for the maintenance

demonstration. While recognizing that dispersion modeling would have

been the preferred method to provide evidence that the PM-10 standards

would be maintained for a three year period after attainment, EPA

accepts the proportional modeling demonstration of maintenance. The

Region considered actual monitoring data for the projected attainment

year (1991) and the two subsequent years (1992 and 1993). Neither the

24 hour nor annual PM-10 standard were exceeded in any of those three

years. In addition, the standards were not exceeded in 1989 or 1990. In

1988 one exceedance was recorded at one of the three monitoring sites

in the nonattainment area. EPA believes that it is reasonable to expect

that the proportional modeling is adequate to predict the three year

maintenance demonstration in the Seattle situation.

The existence of five years of daily PM-10 monitoring values

without any 24 hour or annual exceedances, through and beyond the

attainment plans 1991 attainment year, provides particularly convincing

evidence that both the attainment and the three year maintenance

modeling were reasonably accurate.

The technical modeling analysis described above confirmed that

attainment can be demonstrated in Seattle and could be maintained in

future years using actual emission estimates. The 24-hour PM-10 NAAQS

is 150 micrograms/cubic meter (g/m3), and the standard is

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

hour average concentration above 150 g/m3 is equal to or

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

g/m3, and the standard is attained when the expected

annual arithmetic mean concentration is less than or equal to 50

g/m3 (id.). The demonstration predicted that the 24-hour

design concentration in the attainment year of 1991 will be below 150

g/m3, thus demonstrating attainment of the 24-hour PM-10

NAAQS. The highest 24-hour value in 1993 was 126 g/m3 .

Ambient data show that the area exceeded the annual standard only one

year, for the calendar year 1985 (54 g/m3). The value for

the 1991 annual average was 37 g/m3. Since no annual

NAAQS exceedances have been noted with the current emissions inventory

and since the inventory was modeled using appropriate dispersion

modeling to show attainment of the 24-hour NAAQS, no violations of the

annual NAAQS are likely. Nevertheless, WDOE prepared and submitted a

proportional modeling analysis which demonstrated that the annual

standard was, indeed, attained in 1991 and will be maintained until at

least 1994. Therefore, EPA believes that WDOE has adequately

demonstrated that the annual standard will be attained in the Seattle

nonattainment area, using actual emission estimates.

EPA conditionally approves the Seattle demonstration based on a

commitment from the State to adopt specific enforceable measures on or

before January 1, 1995, that will convert certain actual source

emission to enforceable allowable emission limitations. The control

strategy used to achieve these design concentrations is summarized in

the section titled ``RACM (including RACT).'' For a more detailed

description of the attainment demonstration and the control strategy

used, see the TSD.

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 General Preamble contains guidance

addressing how EPA intends to implement section 189(e) (see 57 FR

13539-13540 and 13541-13542).

In 1985 a limited receptor modeling study was conducted in the

Seattle nonattainment area. The study had several technical problems

and was not used in the attainment/ maintenance demonstration. However,

the study did contain adequate information to determine the likelihood

of precursor problems in the area. The results of this study indicated

that sulfates contributed roughly 10 percent of the mass measured on

the PM-10 samples collected in the Seattle nonattainment area. Nitrate

impacts were much less. Consequently, EPA believes that stationary

sources of precursors provide an insignificant contribution to the

Seattle, Washington, ambient PM-10 concentration and EPA grants the

area an exclusion from PM-10 precursor control requirements authorized

under section 189(e) of the act. 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. 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 (RFP)

The PM-10 nonattainment area plan revisions demonstrating

attainment must contain quantitative milestones which are to be

achieved every three (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).

Reasonable further progress is defined in section 171(1) as such annual

incremental reductions in emissions of the relevant air pollutant as

are required by 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 RFP for this initial moderate area, EPA has

reviewed the attainment demonstration and control strategy for the area

to determine whether annual incremental reductions, different from

those provided in the SIP, should be required in order to ensure

attainment of the PM-10 NAAQS by December 31, 1994 (see section

171(1)). The State of Washington's PM-10 SIP for Seattle demonstrates

attainment in 1991 and maintenance through 1994, and therefore would

normally satisfy the initial quantitative milestone requirement (see 57

FR 13539). However, as mentioned previously, Ecology and PSAPCA based

attainment and maintenance demonstrations on actual emission estimates

instead of the required allowable rates. The State has committed to

adopt the necessary enforceable allowable emission limits by January 1,

1995. Accordingly, as with other requirements discussed elsewhere in

this document, EPA is conditionally approving the submittal relative to

the RFP and initial milestone requirements.

7. Enforceability Issues

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

WDOE and EPA (see sections 172(c)(6), 110(a)(2)(A) and 57 FR 13556).

EPA criteria addressing the enforceability of SIP's 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)).

WDOE's control measures and regulations for control of Particulate

Matter, which are contained in the SIP, are addressed above under the

section headed ``RACM (including RACT).'' These control measures apply

to the types of activities identified in that discussion including, for

example, fugitive emissions from point sources; vehicle resuspended

road dust; and residential wood combustion. The SIP provides that the

affected activities will be controlled throughout the entire

nonattainment area.

Consistent with the attainment demonstration described above, the

SIP requires that all the applicable SIP provisions must be implemented

by December 10, 1993 (section 189(a)(1)(C). In addition to the

applicable control measures, this includes the applicable record-

keeping requirements which are addressed in the supporting technical

information.

The TSD contains further information on enforceability requirements

including enforceable emission limitations; a description of the rules

contained in the SIP and the source types subject to them; test methods

and compliance schedules; malfunction provisions; excess emission

provisions; correctly cited references of incorporated methods/rules;

and reporting and recordkeeping requirements. The local air pollution

control agency, PSAPCA, has the primary responsibility for implementing

the measures in the plan. PSAPCA has many compliance inspectors and, as

discussed further in the TSD, EPA considers PSAPCA's staffing level

adequate to assure that the Seattle attainment plan is fully

implemented. As a necessary adjunct of its enforcement program, PSAPCA

also has broad powers to adopt rules and regulations, issue orders,

require access to records and information, and receive and disburse

funds. WDOE has adequate authority to implement and enforce the plan in

the event PSAPCA fails to make a good faith effort to implement the

regulations.

The residential wood combustion program, fugitive dust control

measures, the diesel inspection program, the transportation demand

management program, and the land clearing fire ban are enforceable.

Discussion and justification of EPA's reasoning can be found in the

control measure section of this document and the TSD.

However, as discussed elsewhere in this document, the use of actual

emission estimates rather than the significantly higher emission limits

allowed in the current PSAPCA regulations is unacceptable. EPA only

could enforce the allowable emissions that are currently contained in

the PSAPCA regulations. There are no mechanisms for EPA to enforce the

emission estimates used in the attainment demonstration because they

are well below the legal limits allowed in the PSAPCA regulations.

A discussion regarding the use of actual instead of allowable

emissions contained in the demonstration portion of this proposed

action provides background for the enforceability decision. The Region

recommends conditional approval of the Seattle attainment plan based on

the commitment contained in the May 11, 1994, submittal which will make

the emissions from point sources enforceable at or below the actual

emission levels used to demonstrate attainment and maintenance. EPA

will need additional technical documentation from Ecology if the

emission levels in the regulatory orders are greater than those used in

the attainment and three year maintenance demonstrations.

8. Contingency Measures

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

nonattainment area SIP's that demonstrate attainment must include

contingency measures (see generally 57 FR 13543-13544). These measures

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

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 PM-10 NAAQS by the applicable statutory deadline.

The Seattle, Washington, plan contains several control measures

which Ecology originally considered contingency measures (November 15,

1991 SIP submittal). In a section referring to contingency measures,

Ecology describes, and ascribes emission reduction estimates to

measures to demonstrate maintenance through 1994. However, these

measures are being relied on to demonstrate maintenance and therefore

cannot be approved as meeting the contingency measure requirements of

section 172. Since the action proposed in this Federal Register

document is related to elements of the SIP due on November 15, 1991,

EPA will not otherwise address the contingency measure requirement at

this time.

III. Implications of This Action

EPA conditionally approves the plan revisions submitted to EPA for

the Seattle, Washington, nonattainment area on November 5, 1990;

December 27, 1990; November 15, 1991; and May 11, 1994. EPA approves

the control measures contained in the plan submissions because they

strengthen the plan by further limiting PM-10 emissions in the area.

EPA also grants an exclusion from precursor control requirements as

described in part II. 5 of this document. EPA will assess the

approvability of these submittals after the State fulfills its

commitment. If the State fails to comply with its commitment, the

conditional approval will become a disapproval.

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

nonattainment areas are due at dates after the November 15, 1991,

deadline. EPA will determine the adequacy of any such submittals as

appropriate and take action at a later date.

IV. Administrative Review

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 2214-2224), 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 2222) from the

requirements of section 3 of Executive Order 12291 for two 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.

Under section 307(b)(1) of the Clean Air Act, petitions for

judicial review of this action must be filed in the United States of

Appeals for the appropriate circuit by August 22, 1994. Filing a

petition for reconsideration by the Administrator of this final rule

does not affect the finality of this rule for the purposes of judicial

review nor does it extend the time within which a petition for judicial

review may be filed and shall not postpone the effectiveness of such

rule or action. This action may not be challenged later in proceedings

to enforce its requirements. (See section 307(b)(2), 42 U.S.C.

7607(b)(2).

The EPA is publishing this action without prior proposal because

the Agency views this as a noncontroversial amendment and anticipates

no adverse comments. This action will be effective August 22, 1994,

unless adverse comments are received by July 25, 1994. If the EPA

receives adverse comments, the direct final rule will be withdrawn and

all public comments received will be addressed in a subsequent final

rule based on the proposed rule (please see short informational notice

published, simultaneously, in the proposal section of this Federal

Register).

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 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 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).

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

the 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.

List of Subjects in 40 CFR Part 52

Environmental protection, Air pollution control, Carbon monoxide,

Hydrocarbons, Incorporation by reference, Particulate matter, Ozone,

Volatile organic compounds.

Note: Incorporation by reference of the implementation plan for

the State of Washington was approved by the Director of the Office

of Federal Register on July 1, 1982.

Dated: May 27, 1994.

Chuck Clarke,

Regional Administrator.

Part 52, chapter I, title 40 of the Code of Federal Regulations is

amended as follows:

PART 52--[AMENDED]

1. The authority citation for part 52 continues to read as follows:

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

Subpart WW--Washington

2. Section 52.2470 is amended by adding paragraph (c) (47) to read

as follows:

Sec. 52.2470 Identification of plan.

* * * * *

(c) * * *

(47) On November 5, 1990, December 27, 1990, November 15, 1991 and

May 11, 1994 the Director of WDOE submitted to EPA SIP revisions for

the purpose of bringing about 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

implementation plan was submitted by the State to satisfy certain

Federal Clean Air Act requirements for an approvable moderate

nonattainment area PM-10 SIP for Seattle, Washington.

(i) Incorporation by reference.

(A) Letters dated November 5, 1990, December 27, 1990, November 13,

1991 and May 2, 1994, from WDOE to EPA submitting the revisions to the

SIP for the State of Washington.

(B) Revisions to the Washington SIP for the purpose of bringing

about 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):

(1) A Plan for Attaining and Maintaining the National Ambient Air

Quality Standard for PM-10 in the Seattle Duwamish Valley, September

1989, adopted November 3, 1990;

(2) Resolution No. 639 (amendments to the PM-10 attainment and

maintenance strategy), adopted December 8, 1988;

(3) State Implementation Plan for Particulate Matter in the Seattle

Duwamish Valley, Supplement, dated November 199l, adopted November 14,

1991; and

(4) State Implementation Plan for Particulate Matter in the Seattle

Duwamish Valley, Supplement, dated January 1, 1994, adopted May 4,

1994.

[FR Doc. 94-15260 Filed 6-22-94; 8:45 am]

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