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Citation: 54 Fed. Reg. 41218 1989

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### Federal Register / Vol. 54, No. 192 / Thursday, October 5, 1989 / Proposed Rules

ENVIRONMENTAL PROTECTION
AGENCY

40 CFR Parts 51, 52, and 81
[AD-FRL-3519-2]

RIN 2060-AC33

Prevention of SignificantDeterioration for Particulate Matter
AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule; notice of opportunity forpublic hearing,
SUMMARY: The EPA is proposing to revise the maximum allowable increases (increments) forparticulate matter under the requirements for prevention of significant deterioration (PSD) in40 CFR 51.166 and 40 CFR 52.21. The revisions being proposed would replace the increments presently measured by the total suspended particulate (TSP) indicator with increments that are (1) measured by an indicator thatfocuses

on particles with an aerodynamic diameter less than or equal to a nominal 10 micrometers (PMo), and (2) generally equivalent to the current TSP increments.

The proposed increments would define maximum allowable increases in concentrations ofPMlo as follows: 4 micrograms per cubic meter (ILg/mg) (annual arithmetic mean) and 8 pg/m 3 (24-hourmaximum) for Class I areas; 17 pg/m3 (annual arithmetic mean) and 30 gig/m 3 (24-hourmaximum) for Class II
areas; and 34 pg/m s (annual arithmetic mean) and 60 gg/m s (24-hourmaximum) for Class III areas.

The EPA is proposing these changes because it believes that the particulate
matter increments should be measured by the same indicator as the revised national ambient air quality standards (NAAQS) for particulate matter.The NAAQS were revised to replace the TSP, indicator with the new PMo indicator on July 1, 1987 (52FR 24634).

Under this proposal, it is EPA's intent
to continue the existing PSD program for particulate matter but to regulate maximum allowable increases expressed as concentrations ofPMlo rather than TSP Forthe purposes of analyzing and tracking the consumption ofthe PSD increments forparticulate matter,EPA is proposing to (1)retain all existing consumption of the TSP increments (to be recalculated as an amount ofPMio increment consumed), and (2) require that all future determinations ofincrement consumption for particulate matter be based on PM1o,beginning on the implementation date ofthe PMo increments. The TSP increments will remain in effect until the implementation date ofthe new PMo increments under the applicable PSD requirements for each State.

The EPA is also proposing revisions to the PSD regulations to assure that the existing PSD program for particulate
matter will continue in effect while operating in accordance with the proposed PM1oincrements. The proposed revisions would affect the PSD requirements contained in 40 CFR parts 51 and 52. Part51 establishes requirements forthe preparation, adoption, and submittal ofState implementation plans (SIP's); part 52
sets forth the Administrator's approval and promulgation ofimplementation plans, and establishes the regulations that operate in the absence ofan approved SIP DATES: Comments on the proposed regulations must be received before December 4, 1989 a public hearing will be held ifrequested; requests to present oral testimony must be received on or before October 26, 1989. The date and time ofthe publichearing willbe announced in a subsequent Federal Register notice. If no one has requested

an opportunity to present oral testimony by October 26, 1989, then no hearing will be held, Supporting information used in developing the proposed rules is contained in Docket No. A-88-19. This docket is available for public inspection and copying between 8:30 a.m. and 3:30 p.m., Monday through Friday. ADDRESSES: Comments should be mailed (in duplicate ifpossible) to: EPA Air Docket (LE-131), Attn: Docket No. A-88-19, Room M-1500, Waterside Mall, 401 M Street SW Washington, DC 20460. The hearing, ifrequested, willbe held in the auditorium at the EPA's Office ofAdministration, Research Triangle Park,North Carolina. FOR FURTHER INFORMATION CONTACT: Dan deRoeck at (919) 541-5593. Persons interested in attending the hearing or wishing to present oral testimony should
contact Mr. deRoeck, in writing at the U.S. Environmental Protection Agency, Office ofAir Quality Planning and Standards,Air Quality Management Division, Noncriteria Pollutant Programs Branch, Mail Drop 15, Research Triangle Park,North Carolina 27711.
SUPPLEMENTARY INFORMATION: 

### The
contents oftoday's preamble are listed in the following outline:
I.Background A.PSD program B.Baseline dates andbaseline areas C.PSD program status D.Promulgation ofPMo NAAQS and

implementation regulations II. Establishing New Increments for Particulate Matter
A. Existing section 163 particulate matter

increments B. Legal authority to promulgate PMlo

increments C. Section 107 area designations D. Selecting equivalent PM~o increments

III Description ofApproach For Developing Equivalent PM1oIncrements
A. Class IIincrements B. Class III increments C. Class I increments D. Selecting the form for the PMlo increments

IV Implementation Issues
A. Geographic applicability ofPMo

increments B. Baseline dates and baseline areas C. Source applicability D. Implementation date E. Grandfathering provisions F Exclusions from increment consumption G.Area source impacts H. Prevention ofsignificant deterioration

monitoring
V. Summary ofProposed Changes to the Regulations

VI. Administrative Requirements
A. Public hearing B. Docket C. Reference documents D. Office ofManagement and Budget (OMB)

review E. Federalism implications F Economic impact assessment G. Regulatory Flexibility Act compliance H. Paperwork Reduction Act

I. Background

A. PSD program

In 1977 Congress amended the Clean Air Act (Act), adding requirements for the prevention of significant deterioration of air quality as Part C of Title I ofthe Act. Under the PSD
program, States are required to adopt a preconstruction review permit program for major new stationary sources and major modifications of stationary

sources, and to prevent significant deterioration of existing air quality levels in areas that are in compliance with the NAAQS.1

The PSD program mandated by Congress is required to balance three primary goals, as specified by section 160 ofthe Act. The first ofthese goals is

to protect public health and welfare.

The PSDrequirements apply to areas classified pursuant to section 107 ofthe Act as attainment or unclassifiable. For pollutants for which noNAAQS have been promulgated, andfor pollutants not subject to the section107 area designation process, the PSD requirements apply everywhere as long as
an area is designated asattainment or unclassifiable forat least one pollutant for which NAAQS exist (i.e., forat least one "criteria" pollutant). 

### 41218

### Federal Register / Vol. 54, No. 192 / Thursday, October 5, 1989 / Proposed Rules

This goal includes the prevention of significant deterioration ofair quality in all areas where the ambient pollutant concentrations required by the NAAQS

are currently being achieved. The second goal emphasizes the protection ofair quality in national parks, wilderness areas, and similar areas of special concern where air quality is considered particularly important. The third goal isto assure that economic growth in-clean air areas occurs only after careful deliberation of theimpacts ofgrowth on air quality by the States and local communities.

The PSD program enacted by Congress is implemented in large part through theuse of "increments" and

area classifications that effectively define "significant deterioration" for individual pollutants. The program also includes a requirement thatmajor new
or modified sources ofair pollution employ the best available control technology (BACT) foreach pollutant subject to regulation under the Act that is emitted in significant amounts. 2 

### In section 163 ofthe Act, Congress defined numerical increments forparticulate matter and sulfurdioxide (SO2

### )as the maximum allowable increases, above baseline levels in the ambient concentration ofthe pollutants in a PSD

area. Thus, the section 163 increments limit the allowable.increase3 in the ambient concentrations ofparticulate
matter and SO2 in any area that 

### isin 

### compliance with the NAAQS.3 

### Congress determined that the particulate matter increment levels adopted in the Act provide forboth protection of air quality and reasonable industrial and economic expansion in PSD areas.

The Act's area classification scheme for PSD establishes three classes of geographic areas and applies increments ofdifferent stringency to each class. Congress established Class Ifor areas of special national concern where the need to prevent significant deterioration in air quality is greatest. Consequently, the mostrestrictive increments apply in Class Iareas. Class Iareas include all international parks as well as national parks, national wilderness areas, and national memorial parks exceeding

aThe EPA has defined "significant" emissions increases (intons per year) for pollutants subiect to regulation under the Act [see the PSD regulations at 40 CFR 51.166(23)(i) and52.21(23)(i)]. Using these significance levels. certain small modifications and emissions ofcertain pollutants at new sources could be exempted from PSD review on the grounds that such emissions would be insignificant, i.e., "de minmis.

3The increments for particulate matter enacted by Congress in 1977 and listed in section 153 were based on the NAAQS forparticulate matter,which until last year used TSPas the unit ofmeasurement (indicator) for ambient levels ofparticulate matter. 

### certain sizes and existing on the effective date ofthe 1977 amendments. Section 162(a) prohibits the States or EPA from redesignating these areas to other classifications.

Less restrictive increments apply in

areas designated as Class IIor Class III. Class IIareas are, initially, all PSD

areas that are designated as attainment

or unclassifiable with respect to the NAAQS and that are not classified in theAct as Class I areas. Class IIareas (except statutorily defined Class Iareas) may be redesignated by the States to Class Ior Class III under certain circumstances. The Class III area designation would permit more deterioration in air quality in specific

areas designated by the States for higher levels ofindustrial development and emissions growth. There are as yet no Class III areas. B. Baselinedatesandbaselineareas In an increment system, the "baseline date" marks the date after which increases in the emissions ofa pollutant from any source within a defined geographical "baseline area" will be counted in determining how much increment is available for further economic development, i.e., after this date, increases in emissions "consume" increment. Hence, both thebaseline date and the associated baseline area
are important factors. For the existing particulate matter increments specified in section 163 oftheAct, the ambient air quality on thebaseline date is the baseline concentration against which increment consumption is measured. All ambient concentrations resulting from (1)actual emissions from sources in existence on the baseline date, and (2) allowable emissions from major stationary sources permitted before January 6, 1975, butnotyet in operation

on the baseline date, are part ofthe baseline concentration forparticulate matter.

The PSD definition of "baseline date" provides two reference points for purposes ofdetermining increment consumption: (1)The "major source baseline date" and (2)the "minor source baseline date. 4The major source baseline date is the date after which emissions changes resulting from construction at any new ormodified major stationary source affect the

The terms "major source baseline date" and "minor source baseline date" were added to the definition of"baseline date"when EPA promulgated new PSD increments for nitrogen dioxide (NO 2)onOctober 17,1988.These terms clarified points to be used for majorand minor

sources. See preamble forfinal NO2increment regulations for further discussion ofthe adoption of these terms (53 FR 40656). 

### amount ofincrement used. The Act established January 6,1975 as the major

source baseline date forthe statutory increments for particulate matter and SO2 .The "minor source baseline",date 

### is the date after August 7 1977 on which the first complete PSD application for a major stationary source is submitted in

aPSD area. Starting on this date, all emissions increases in the baseline area (including those from minor sources) affect the amount ofincrement available forfuture growth. For particulate matter and SO 2

### ,the minor source baseline date has already been established in many PSD areas. C.PSD programstatus The PSD requirements have been incorporated into the Code ofFederal Regulations (CFR) under both parts 51 and 52 ofTitle40. In part 51, thePSD regulations at section 51.166 set minimum requirements forStates for the preparation, adoption, and submittal of

a PSD program as part ofan approved SIP In part 52, EPA promulgated PSD requirements at §52.21 for direct implementation ofa PSD program involving the Administrator's preconstruction review and approval of

new ormodified PSD sources in the absence ofa State PSD program under

an approved SIP

Approximately one halfofthe States have EPA-approved PSD programs for particulate matter (pursuant to §51.166) incorporated into their SIP's.The remaining States have not submitted approvable programs. The EPA has delegated its authority to issue PSD permits under section 52.21 to most of these States, butcontinues to issue PSD permits directly for the remaining States.

D.PromulgationofPMoNAAQS and implementationregulations

On July 1,1987 (52 FR24634), the EPA adopted final regulations that revised the NAAQS for particulate matter.With these revisions,EPA eliminated TSP as the indicator for the NAAQS and replaced it with the PMio indicator. Both theprimary and secondary standards

were revised taking into account the mostrecent scientific information available on thehealth and welfare effects associated with particulate matter, as well as the change in the ambient indicator forparticulate matter.

Inthe same Federal Register, EPA adopted final regulations to implement the revised standards. Included in these final ruleswere amendments to the PSD' requirements, in 40CFR Parts 51 and 52, to address the new PMo indicator as a regulated form ofparticulate matter.The EPA did not,however, revise the PSD 41219

### Federal Register ,/ Vol. 54, No. 192 / Thursday, October 5, 1989 / Proposed Rules

increments forparticulate matter at that time to account for the new PMo indicator. Instead, EPA clarified that the existing statutory particulate matter increments were meant to be measured in terms ofTSPbecause that was the indicatorfor the particulate matter NAAQS when Congress adopted the "particulate matter" increments in 1977 The EPA also announced its intention to promulgate increments based on the

new PMo indicator pursuant to section 166 ofthe Act (52FR 24672).



### The EPAhad originally proposed to adopt PMio primary NAAQS but to retain the TSP indicator forthe secondary NAAQS [49 FR 10408]. The 

### EPA, therefore, suggested that itmight promulgate and implement new PMio increments, and continue to require implementation ofthe statutory TSP increments as well [50 FR 13147]. The 

### EPA received numerous comments expressing opposition to this "dual increment system" and to the retention ofTSPas an indicator for measuring the particulate matter increments. On the otherhand, comments received from

some State and local airpollution control agencies and other commenters urgedEPA to retain the existing TSP increments. Today's action proposes a single setofincrements for particulate matter, which wouldbe based on PMo.

In order to implement thePMo increments and to maintain a single Increment system, the Administrator suggested that States could request elimination ofthe area designations withintheirjurisdiction, made under section 107 of the Act ("section 107 areas") with respect to attainment status relative to the old TSPNAAQS. Through thismeasure, the existing Class IIand Class IIIparticulate matter increments wouldbe rendered inoperative, 5

### and the increment program forparticulate matter in these areas would be governed by the new PMo increments.

Unlike the Class IIand III areas, Federal mandatory Class Iareas are defined in the Act without reference to the section 107 area designations. Consequently. EPA cannot redesignate

or eliminate Federal mandatory ClassI

areas in orderto render the Class ITSP increments inoperable. To avoid the burdens inherent to a dual increment

Undersection 163 oftheAct, Class II increments apply to Class iiareas, which aredefined as areas that have been designated attainment or unclassifiable under section 107 ofthe Act.The EPA haspreviously indicated thatsection 107 areas are pollutant-specific (see 52 FR24634,July 1,1987; pp. 24701-2). Therefore, eliminating the section 107area designation forparticulate matter for aparticular geographic area results in the existing particulate matter increments being inapplicable to that particular geographic area. system, EPAtherefore suggested that it might develop PMio increments that are "equivalent in effect" to statutory Class ITSP increments, and allow States to

use these new Class I PMo increments

as surrogates for the TSPincrements (52 FR at 24685-24686).

II. Establishing New Increments for Particulate Matter

A. ExistingSection163Particulate Matter Increments
In the 1977 Amendments to the Act, as discussed above, Congress set numerical PSD increments in section 163 for both particulate matter and SO 2. In establishing the PSD increments for these two pollutants, Congress used the then existing NAAQS for each pollutant

as the benchmark for determining what constitutes "significant deterioration. It
set the increments as percentages ofthe NAAQS level for each pollutant, with the same percentage, 25 percent and 50 percent, respectively, forClass IIand Class III. Congress also retained the

same averaging times and units of
measurement (jg/m}as the NAAQS. Although section 163 does not expressly define the particulate matter increments in terms ofa specific irndicator, EPA reasoned that Congress' knowledge that TSP was the indicator for the particulate
matter NAAQS, and that the TSP standards were the starting point for the increment levels when the increments

were established in 1977 meant that TSP was also the appropriate measure for the particulate matter increments in section 163 (52 FR at 24700-24701). As a consequence, EPAconcluded that the statutory particulate matter increments could not simplybe-administratively redefined and considered to be PMjo increments following the revision ofthe particulate matter NAAQS; rather, EPA decided that is must promulgate new particulate matter increments, expressed in terms ofthe new PMo indicator.

B. Legal Authority To Promulgate PMe 0 Increments

As previously described in the July 1, 1987 PMo notice, EPA believes that it has the authority to promulgate new Increments for particulate matter, measured by the new PM1oindicator, pursuant to s6ction 166 ofthe Act (52 FR
at24700). Section 166(a) states that "[i]n the case ofpollutants for which national ambient air quality standards are promulgated after the date ofenactment ofthis part, [the Administrator] shall promulgate such regulations [toprevent the significant deterioration ofair quality]. Under this authority, EPA recently promulgated PSD increments and associated regulations for NO2 (53 FR 40656, October 17 1988). Itis not as clear from the face ofthe statute, however, how Congress intended section 166 tobe applied to the circumstances here, where the particulate matter NAAQS and control strategy are redirected to an entirely

new indicator (PMo). The EPA, therefore, was faced with the questions ofwhether section 166 applies to the unique situation presented by PM 10 and, if so, how it applies.

The EPA has concluded that the
statute authorizes the Agency to promulgate new increments for a pollutant when it changes the NAAQS
to a new indicator and sets new levels,

as the July 1,1987 revisions did. The PMo NAAQS were not based on the preexisting TSPNAAQS. Instead, they represent a fundamental reexamination of the present understanlding ofthe health and welfare effects associated with ambient particulate matter. Selection of the PMo indicator was based on an abundance of scientific data demonstrating that those particles small enough to penetrate to the sensitive thoracic region ofthe respiratory tractposed the greatest risk
to human health. In addition, EPA determined that the new PMo standards provide sufficient protection for relevant welfare effects associated with ambient particulate matter 6(52 FR at 24646). In short, the selection of a new indicator and new levels for the standards establishes a new NAAQS for particulate matter for purposes of section 166.The EPA, therefore, believes thatwith the promulgation ofthe new PM 1oNAAQS, it has both the responsibility and authority under sections 166 and 301 ofthe Act to promulgate new particulate matter increments to be measured in terms of 

### PM1 

### o. The EPA couldpromulgate new PMo increments and simply add them to the existing TSPparticulate matter increments set forth in section 163 of the Act. However, as indicated in the July 1, 1987 Federal Register notice, EPA believes that the resulting dual increment system would prove unnecessarily burdensome and cumbersome for permit applicants and for States that would implement it (52 FR at 24701). In addition, retaining the TSP increments after the transition period would appear to make little

6The EPAbelieves that large particles In sufficient concentrations could present some welfare concerns, but that the PMo NAAQS as promulgated and the controls necessary to meet such NAAQS willadequately address any such

concerns (52 FR at 24645-4%.and24700). 

### 41220

### Federal Register / Vol. 54, No. 192 / Thursday, October 5, 1989 / Proposed Rules

sense, because (1)both the primary and secondary particulate matter NAAQS willnow be measured exclusively by thePMo indicator, and (2)PMo increments can serve to prevent significant deterioration of air quality forparticulafe matter as well as can increments measured by the TSP indicator. Thus, EPA believes that promulgating PM10

### increments to replace, rather than supplement, the statutory TSPincrements represents the most sensible approach.
C.Section107AreaDesignations

Section 107(a) ofthe Actrequired that each State be divided into air quality control regions (AQCR's). Section 107(d), added by the 1977Act Amendments, directed each State to submit a list specifying all AQCR's, or portions thereof, as attainment areas (areas in which theNAAQS had been attained), nonattainment areas, or unclassifiable on the basis of available information. Together, these areas are commonly referred to as "section 107

areas. The PSD provisions in part C of the Act generally apply in all section 107

areas that are designated as attainment

orunclassifiable (40 CFR 51.166(i)(3)). 

### With respect to the increments for particulate matter, the existing Class II TSPincrements (and Class III 

### increments, ifthere were any) specifically apply to section 107 areas designated as either attainment or unclassifiable for TSP as long as such

areas are not classified as Class I PSD

areas.

Because ofthe importance ofthe section 107 area designations to the 

### applicability ofthe TSP increments, the EPA announced in the July 1,1987 Federal Register its position to temporarily retain the TSP area designations beyond the date on which EPA approves a State's revised PMo SIP7This would protect the 

### applicability ofthe TSP increments until

a PMio increment system could be established. The eventual replacement of the TSP increments with PMo increments that operate independently from the section 107 TSP area

When EPA adopted the final regulations under 40 CFR Part 51 for State implementationof the revised PM~oNAAQS. States were encouraged to request redesignation oftheir TSPnonattainment

areas to "unclassifiable" when they submitted their revised implementation plan for attaining the PMo NAAQS (52 FR at 24682). The discussion in today's Federal Register, concerning EPA's ultimate deletion of all TSParea designations when States adopt the PMo increments, presumes that Stateplan revisions for attaining the revised PM~o NAAQS will have already been submitted to EPA and approved. Ifthis is not the case,then deletion oftheTSP nonattamment area designationswill necessarily be delayed. Seesection IV.B for further discussion. designations would finally negate the need forEPA to require that these TSP

area designations be maintained. Accordingly, in the same Federal Register, EPA described an approach whereby the Agency would approve State requests to delete section 107 area designations forTSP (in order to render the Class IIand IIITSP increments inoperable) simultaneously with its approval to each State's plan revision containing the PMo increments (52 FR at 24701, middle column).

In giving this approach further consideration, EPA now believes thatit is not necessary for States to request the deletion oftheir TSP designations. Instead, with today's notice ofPM 0 increments, EPAis proposing an alternative approach, whereby itwould automatically delete the TSP designations from the listing for each State contained in subpart C of40 CFR part 81. The actual deletion by EPA of the TSP designations foreach State would occur atthe same time that EPA either (1)approves a State's revised PSD plan containing the PMo increments, (2) approves a State's request fordelegation ofPSD responsibility under 40 CFR 52.21(u), or (3)promulgates the PMo increments into a State's SIP where a State chooses not to do so (see revised subpart C, 40 CFR part 81).8 In all cases, it is EPA's intent via this approach that the TSP increments remain in effect until the PMo increments replace them under the applicable PSD program.

As already noted, once the section 107 designations forTSP are deleted for a particular State, the statutory Class II and Class IIITSP increments will no longer have any applicability, since those increments by definition apply only in Class II and Class III areas for TSP respectively, i.e., section 107 areas designated as attainment or unclassifiable for TSP

The Class Istatutory increments are not similarly affected by the deletion of the section 107 area designations, since mandatory Class I areas are defined in the Act without reference to section 107

area designations. However, EPA believes that it can use its authority under sections 166 and 301 to develop Class IPMo increments generally equivalent to the statutory Class ITSP increments, which could serve as surrogates for the statutory increments. With the surrogate PMo increments in place, the statutory TSPincrements

It should be noted that while EPA intends to delete the TSP area designations, itwillnot delete thereferences to the defined geographic areas for which the attainment status designations havebeen made. Thismatter is discussed further in section IV.B., Baseline dates andbaseline areas. 

### would no longer be necessary, and would be dispensed with as aregulatory

measure. Using the surrogate PMo increments wouldprovide generally equivalent prevention ofsignificant deterioration of air quality m these Class Iareas while avoiding the problems inherent to a dual increment system.
D. SelectingEquivalent PMo Increments

In addition to the goals which Congress setforth forthe PSD program, section 166(d) ofthe Act requires any increments orother measures that EPA promulgates under section 166(a) to be "at least as effective as theincrements established in section 163"in preventing significant deterioration ofair quality. The EPA has considered two approaches for the selection of PMo increments that itbelieves couldbe considered tomeet this test: (1)the "equivalent to statutory increments" approach, and (2)the "percentage of NAAQS" approach.

The increments derived by either of the two approaches would be expressed

as numerical measures and could be implemented similarly to the statutory increments. Moreover, either setof increments would provide clean areas of the country withprotection against significant deterioration ofair quality, especially since both sets ofincrements could be implemented by retaining the baseline areas and baseline dates that have already been established for the statutory TSPincrements (thereby taking into account the amount of increment already consumed under the existing PSD increments for particulate matter).
1."Equivalent to statutory increments" approach

One approach is to set PMo increments which will be as nearly equivalent as possible to the section 163 particulate matter increments in their effect on TSP increment "consumption, thereby retaining essentially the same limitations on future deterioration ofair quality and economic growth as was allowed under the statutory TSP increments. The PMo increments developed pursuant to this approach could thenbe regarded as reasonable surrogates for the statutoryTSP increments. For this approach, the statutory TSP increments necessarily

serve as thebenchmark fordeveloping

new PM,o increments.

Accordingly, EPA considered the amountof TSPincrement "consumed" by a sample population ofPSDpermitted stationary sources since the 41221

### Federal Register / Vol. 54, No. 192 / Thursday, October 5, 1989 / Proposed Rulescommencement ofthe PSD system.The EPA then determined the PMo increment value, foreach area classification and averaging time, that wouldprovide an "equivalent" amount ofPMo increment consumed for the particular population of sources examined. 9

### For example, ifa source in a. Class IIarea causes a 24-hour concentration increase of18.5 1.g/m3 of TSP over the baseline concentration, then that source consumes 50 percent of the Class II24-hour increment for TSP '37 pg/m3). Then, by estimating the ambient PMo concentrations that such

source would cause, a Class II,24-hour PMo increment could be selected that would result in 50 percent ofthat new increment being consumed. 10



### Because the annual increment levels derived using this approach were geometric mean values, a conversion factor (1.12) was used to adjust these increments to arithmetic mean values. The proposed Class IPM1

### oincrements derived from this approach are 4p$i/m (annual arithmetic mean) and8jig/m (24-hour). The proposed Class II increments are 17 kg/im 3 

### (annual arithmetic mean) and 30 pg/m3 (24- hour).

Class III increments were derived in a different manner because currently there are no Class IIIareas for particulate matter.The EPA, therefore, chose Class IIIPMo increments that are double the levels ofthe Class IIPMo increments, using theprecedent set by Congress in selecting Class III increments for particulate matter and SO 2 

### that were twice as large as the respective Class IIincrements.1 

### IThus, the proposed Class III PMo increments

are 34 jig/m (annual arithmetic mean) and 60 1.g/me (24-hour).

2. "Percentage ofNAAQS" approach

A second approach would be forEPA to establish PMo increments that bear the same percentage relationship to the

new PMo NAAQS as the section 163 TSPincrements bear to the TSP NAAQ from which they were derived. 12 

### Thus,

Because stationary sources emit particulate matter with varying PM~o/TSPemissions ratios, itis not possibleto select PMo increments that represent the same percentage ofTSP increment consumption forall stationary sources.

10 The actual derivation ofPM,o increments for Class I,II,and III areas using the "equivalent to statutory increments" approach is described more fully in sectionIII and in the docket forthis proposed action.

I Congress selected ClassIIincrements that

were 25 percent ofthe respective NAAQS. and Class III increments that were 50percent ofthe respective NAAQS.

12 Unlike the PMoNAAQS. whichprovides for the same levels for both theprimary and secondary standards, the TSP NAAQS has lowerlevels for the 

### thepercentage ofNAAQS approach would define equivalent amounts of "significant deterioration" relative to the standards fromwhich the increments

are derived. The EPA considered this approach because the legislative history ofthe 1977Clean Air Act Amendments demonstrates that Congress selected the various section 163 increment levels by using such an approach [seeH.R. Rep. No.95-564, 95th Cong., 1st Sess. (1977), 

### reprinted in 3ALegislative History of the Clean AirAct Amendments of1977 ("Legislative History"), at 528-531; H.R. 

### Rep. 95-294, 95th Cong., 1st Sess. at 153, 

### reprinted in 4Legislative History, at 2620]. Forboth TSP and SO2 

### ,the two pollutants forwhich PSD increments

were established in section 163, Congress chose Class IIincrements that

were 25 percent ofthe lowest standard and Class III increments that were 50 percent of the lowest standard. For Class Iareas, the TSPincrements selected were 6.7 percent ofthe lowest standard, while the SOs increments selected were 2.5 percent ofthe lowest standard.

Congress established the original increment levels to provide an appropriate balance between protecting air quality and providing an adequate margin for industrial growth.The PMo increment levels that would result from using this same percentage-based approach would reflect a similar balance, because industrial sources typically would not be prevented from constructing in an area where the full Class IIincrement is available. Also, since the new PM 0 

### NAAQS are based

on EPA slatest findings regarding harm to health and welfare posed by particulate matter, this approach reflects

an equivalent evaluation forPMo to that used by Congress in choosing the section 163 increments from the TSP standards.

ThePMo levels ofboth the primary and secondary NAAQS are 50 Ag/m3 for the annual standard; and 150 ig/im 3 

### for the 24-hour standard (40

### CFR 50.6). Using the "percentage ofNAAQS" approach, the Class IPMo increments would be 3pjg/m s 

### (annual arithmetic mean) and 10 pg/m3

### (24-hour. These values are 6.7 percent ofthe annual and 24-hour standards, respectively. The Class IIPM

,

### oincrements would be 13 11g/Ms (annual arithmetic mean) and 37 jig/m (24-hour), i.e., 25 percent ofthe

secondary NAAQS. The section 163 particulate matter increments were based onthe lower secondary level for the 24-hour concentration, but relied onthe annual primary value because the lower value associated with the secondary "standard" was regarded only as a guidefor attainment purposes. 

### respective standards. The Class III PMo increments would be 25jg/im (annual arithmetic mean) and 75 pjg/m 3 

### (24-hour), i.e., 50 percent of the respective standards.
3.Comparison ofincrement levels

The EPA compared the PM0 

### increment levels derived from both the "equivalent to statutory increments" and "percentage ofNAAQS" approaches. This comparison indicated that,for the annual averaging time,PMo increments derived from the "percentage ofNAAQS" approach would establish lower maximum allowable increases in concentrations ofPMo than would PMio increments derived from the "equivalent to statutory increment" approach. The difference between thelevels for the annual increments uting the two independent approaches is lessened somewhat by taking into account the fact that the deterministic annual increments would possess lower levels ifexpressed as equivalent statistical annual increments.13



### For the 24-hour averaging time, which is typically the more critical averaging time forsource impact analyses, the differences in the numerical levels were
more significant thanwere the annual increment differences. The numerical levels ofthe statistical PMo increments (derived fromthe "percentage of NAAQS" approach) are larger than the levels ofthe deterministic PMo increments (derived from the .,equivalent to statutory increment" approach) and would appear to allow for considerably greater increases in concentrations ofPMo. However, to identify the actual difference between the two sets of24-hour increments, they mustbe statedin the same form, i.e., either as statistical ordeterministic increments.

The EPA assessed the general relationship between the statistical and deterministic forms for the 24-hour averaging time (Tikvart,1989). Based on this analysis, the level ofa statistical increment would be lower than the level ofits equivalent deterministic counterpart. Thus, if the deterministic 24-hour increment levels derived from the "equivalent to statutory increments" approach were tobe expressed as equivalent statistical increments, they

.. In proposing the statistical form for the PM~o NAAQS, EPA assessed the relationship between statistical and deterministic forms ofan annual standard. Based on this analysis EPAfound that,on average, thelevel of'an annual statistical standard equivalent to deterministic standard would be approximately 0.9 times the level ofthat deterministic standard (49 FR 10408, March 20. 1984. p. 10413). 

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would have lower numerical values. This would support the original finding that the 24-hour increments derived from the "percentage ofNAAQS" approach would allow forgreater increases in concentrations ofPMo than would the increments derived from the "equivalent
to statutory increments" approach.

The EPA has already used the "percentage ofNAAQS" approach, and believes that it is an appropriate approach to consider ingeneral for setting PSD increments. 4 This approach is simple to implement and reflects the methodology which Congress used to establish the SO and TSPincrements in section 163 ofthe Act. However, EPA Is today proposing to establish PMo increments using the "equivalent to statutory increments" approach because it believes that PMo increments derived from the statutory (TSP)increments better match congressional intent in the special case where thenew increments for particulate matter are Intended not only to prevent significant deterioration ofPMo air quality, but also to replace (rather than supplement) the existing section 163 increments forparticulate
matter.

Increments established under the "equivalent to statutory increments" approach preserve roughly the same growth opportunites and limitations on deterioration ofair quality as that established by Congress in section 163. Although the numerical levels would be established to reflect the PM~o component ofparticulate matter this approach would preserve to the greatest extent possible the effects of the increments established by Congress. In other words, the new PMo increments would attempt tomirror the statutory paticulate matter increments and reflect, in the aggregate, the level ofincrement that would have been consumed ifthe PMo increments (rather thanTSP increments) has been in place since 1977 Therefore, EPA is proposing PM~o increments derived from the "equivalent
to statutory increments" approach under today's notice.

The EPA solicits comment on today s proposal concerning new PMo increments which would replace the existing TSP increments under section 163 ofthe Act. In particular, EPA invites
commenters to respond to the following topics: (1)The rationale forproposing PMo increments under the "equivalent
to statutory increments approach" (2)

4The EPA followed the "percentage of NAAQS" approach indeveloping the NO increments, promulgated on October17, 1988(53 FR 40657). In that case.however, there were no statutory increments fornitrogen oxides from which new NO, increments could be denved. 

### the rationale fornot proposing PMo increments under the "percentage of NAAQS" approach. (3)the numerical levels ofthe proposed PMo increments: and (4) whether the proposed 

### increments would serve as adequate surrogates for the TSP increments.
IlL.Description of Approach for Developing EquivalentPMo Increments

This section describes the procedures that EPAfollowed in developing PMo increments that it believes are generally equivalent to the statutory Class 11, Class III, and ClassI increments, respectively. As described in detail below, the development ofthese PMio increments involved two Important steps. The first step was to convert the levels ofthe TSP increments to equivalent PM~o levels.The second step

was to convert the resultinglevels ofthe equivalent PMo annual increments from geometric means values (thebasis for the-TSP NAAQS) to arithmetic mean values (thebasis for the PM~o NAAQS).

A. ClassII Increments

For Class IIincrement selection, EPA based its proposed PMto increment levels on Information in an existing new
source review (NSR) data base. The NSR data base, developed byEPA, consists ofinformation fromover 500 existing PSD/NSR permits issued nationwide for criteria pollutant emissions between 1977 and 1984. There

were 249 permits issued forparticulate matter emissions having sufficient information to estimate PMo emissions and, subsequently, PMo increment consumption from each source. The population ofpermits used is believed to be representative of mostPSD/NSR applications.

First, EPA plotted a distribution ofthe predicted air quality impacts ofTSP (taken directly from the NSR data base) for each ofthe 249 sources. Byplotting the sources according to themagnitude oftheirTSP impacts, EPA could determine thenumber ofsources (expressed as apercentage ofthe total number of sources)with predicted TSP impacts at or below agiven value. A similar distribution ofPMto air quality levels was plotted using (1)the projected TSP air quality levels reported by the source, and (2)PMo emission factors to estimate PMo emissions for emission units at the source within the 249 sources. A detailed description of themethodology ispresented in a report entitled "Technical ReportEquivalency ofAlternative PMo Increments" (Radian Corp., March, 1989).This document is available in the docket forpublic inspection. Based on the predicted ambient TSP and PMio impacts, EPA calculated the percent increment consumption (for the annual and 24-hour averaging periods) for each source based on the statutory TSP increments and various trial PMo increments. The trial PMo increment levels were 13, 14, 15, 17 and 18 Lig/M 3 

### (annualgeometric mean); and 28, 30, 33, and 37 pg/m3 

### (24-hourmaximum).

A comparison ofthe TSP and PMo increment consumption data provided the basis for determining which ofthe alternative PMio increment levels would result in the same average percent increment consumption as the existing TSPincrement consumption. This comparison was performed by calculating the area under the curves representing the distributions plotted for each increment alternative. For each PMo increment alternative, EPA calculated an "increment consumption index. This index represents the amount ofPMio increment consumed on
a source-aggregated basis relative to the amount ofTSPincrement consumed on
a source-aggregated basis. The increment consumption index value for each PMo increment alternative is shown in Table 1.

TABLE 1-NATIONWIDE IMPACTS OF AL

TERNATIVE CLASS IIAREA 

### PMio INCREMENTS

Increment Alternative class It PMo Increments, consumption (ug/m imdexb/mearf

24-Hour average: PM,o-28

........................................... 108 PMIo-30

........................................... 100 PMo-33

........................................ 91 PMo-34

........................................... 88 PMo-37

........................................... 81 Annual average: PM,o-13

........................................... 118 PMio-14

........................................... 110 PMIo-15

........................................... 100 PMo-17

........................................... 90 PM1-18

........................................... . 8a

Mo-28 refers to a PM 0 increment alternative with anumerical value of 28 pg/m 3 The increment consumption index values are a relative indicator of nationwide increment consump- tion under the Class IIincrement PM,0 alternatives. Each value isrelative to the existing TSP increment baseline value which isnormalized to a value of 100.

IBased on the mean PM,0 air quality impacts distribution.



### As Table 1illustrates, the Class II PMo increment levels of 15

### jg/m3 

### (annual geometric mean) and 30jg/m 3 

### (24-hour maximum] are associated with

an increment consumption index of100. This means that these PMo increment levels result in the same overall amount ofincrement consumption as the TSP increments on a source-aggregated basis. Selection of thesePMo increments should provide air quality 41223

### Federal Register / Vol. 54, No. 192 / Thursday, October 5, 1989 / Proposed Rules

protection that is roughly equivalent to the TSPincrements.

TheEPA recognizes, however, that individual sources could be affected differently with respect to the amount of "equivalent" PM 1

### oincrement that each would consume, depending on localized conditions and thePM~o emissions fraction foremission units at a given

source. Consequently, EPA further examined the equivalent Class IIPMo increments to determine their impacts relative to several specific criteria. These criteria included the following: (1) The number ofsources and source types with PM10 

### increment consumption above and below TSPincrement consumption, (2)the extent to which a source's PMio increment consumption exceeds orfalls below TSP increment consumption, (3) the availability ofcontrol technology to bring new sources into compliance with the proposedPMio increments, and (4) the cost ofbringing new sources into compliance with the equivalent PMo increments.The impacts associated with the equivalent PM1

### oincrement levels of 15j1g/m 3

### (annual geometric mean) and 30 pg/m 3

### (24-hour maximum) are discussed below.

The EPA examined the 249 sources in the NSR data base in orderto determine the difference between TSPincrement consumption and PMo increment consumption (based on the selected equivalent PMo levels) for each individual source. The results ofthis analysis showed that some sources

consume more ofthe available increment under the equivalent Class II PMo increments than under the existing TSP increments, and some sources

consume less.There was essentially no difference in the percentage of increment consumed (i.e., lessthan 5 percent difference) forabout 91 percent of the 249 NSR data base sources. A detailed summary of this examination is presented in the referenced Technical Report available forpublic inspection in the docket.

Of the 249 individual sources that

were examined, only four were projected to exceed the equivalent PMo increment levels.These sources included: (1)A petroleum refinery located at a synthetic fuels plant, (2)a steel fabrication plant, (3)an electric utility, and (4)a food processing facility. This projection assumes that the sources would apply the same level of control as they applied to meet the TSP increments. Upon closer examination of these specific sources, EPA has determined that exceedances ofthe PMo increment by sources ofthese types are not likely to occur. This judgment was based on (1)The unusual characteristics ofthree ofthe affected

sources relative to other sources of these types (i.e., they werelocated in complex terrain); and (2)the availability ofexisting control technologies that could be applied to ensure that similar

new sources would not exceed the PMo increments.

For all four source types, control technology is available that can bring

new sources ofthese types into compliance with the proposed PM~o increments. A cost and economic evaluation ofthese sources was performed as part ofan impact assessment (described m Section V of thispreamble). The evaluation showed that no unreasonable economic impacts would be imposed on future sources to achieve compliance with the proposed PMo increments. Details on the cost and economic evaluation are presented in a report entitled "Cost and Economic Impact Assessment forPMio Increment Options" (Radian Corp., April 1988). This report is available in the docket for publicinspection.

B. ClassIIIIncrements

There are currently no Class IIIareas. Forselection ofequivalent Class III PMo increments, EPA also followed the approach used by Congress to establish Class IIITSP increments when it simply doubled the Class II increments. Using this approach, EPAproposes to establish the Class III PMlo increments at twice the level ofthe Class IIPM~o increments. Consequently, the equivalent Class III PMo increments would be 30 t.g/m 3

### (annual geometric mean) and 60 gkg/m 3

### (24-hour maximum).
C.ClassIIncrements

There have been relatively few major

sources constructed in the vicinity of Class Iareas, which emit significant amounts ofparticulate matter. Consequently, there is significantly less information available on current patterns ofparticulate matter increment consumption for Class Iareas thanis available for Class II areas. In selecting Class Iincrements, EPAdid not attempt to compare thepercentages ofTSP increment and PMo increment consumed on an aggregated basis, as
was done forthe Class IIincrement analysis. Instead, EPAexamined directly the TSPand PMo impacts of 16

sources in theNSR data base, with known Class Iarea TSP impacts.

For 12 ofthe 16 sources, EPA relied on the Class Iarea TSPimpacts reported in the data base to estimate the maximum Class Iarea PMo impacts. The estimated PMo impacts were derived from the TSP impacts after first calculating a PMlo-to-particulate matter emissions ratio foreach source. The resulting ratios were then applied to the known TSP impacts. For theremaining four sources, EPA modeled each one based on particulate matter emissions data and source characteristics contained in the NSR data base to project the TSP and PMo ambient impacts. The referenced Technical Reportprovides the details ofthis analysis and is available for public inspection in the docket for this proposed rulemaking.

Based on its examination of the percentage ofincrement consumed by each ofthe 16 sources, the EPA believes that PM 1

### oincrements of4 Lg/m 3

### (annual geometric mean) and 8 tg/ms

### (24-hour maximum) are the most appropriate PMo levels to serve as surrogates for the existing TSP increments. For several of the sources, the selected PMio levels would result in a greater portion of PMo increment being consumed than ofTSP increment. In no case, however, would a PMo increment violationbe predicted.

Although EPAbelieves that these PMo increment levels will afford Class I

area protection that is generally equivalent to the protection provided by the existing TSPincrements, therelative stringency oftheincrements could vary by source type, depending on the PMoto-particulate matter emission ratios for individual sources. For example, a

source that emits a small volume of PMo relative to the entire volume of particulate matter emitted conceivably could comply with thePMo Class I increments while still emitting more total particulate matter than would be allowed under the existing increment.

Recognizing the small data base that

was available to develop the equivalent Class IPMo increments, EPA sought another way to analyze the potential impacts ofother sources on the selected PMo increment levels. For thepurposes ofthis additional analysis, it was assumed that the 249 particulate matter

sources included in theNSR data base

were located near enough to Class I

areas so that the point ofmaximum 

### impact would occur in the Class I area; although, In fact,this would only be true of 16 ofthose sources. Through this analysis, it was determined that only 2 ofthe 249sources in thedata base (or less than Ipercent) would exceed the existing Class ITSPincrements while complying with the equivalent Class I PMo increments. Based on this larger sample ofsources, it would be expected that thenumber ofsources whose impacts would potentially exceed the existing Class ITSP increments while complying with the PMio increments, would be very small. 

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While EPA believes that the results of this analysis help to demonstrate that the selected PMo increments can reasonably serve as surrogates to the statutory TSP increments, it is also important to recognize that, in Class I
areas, the increments have a special function that does not apply to the increments inClass II and Class III

areas. In Class I areas, increments are a

means ofdetermining which party (the applicant orthe permitting agency) has the burden ofproofwith respect to demonstrating any specific adverse impacts ofa proposed PSD source within a Class I area. Congress recognized that Class I areas tend to have unique air quality concerns and, in section 165 ofthe Act,set forth procedures to afford special provisions beyond the use ofClass I increments.

The mechanism created by Congress for achieving the extra degree of protection for Class I areas relies on the authority vested in the Federal land managers (FLM's) who oversee Class I

areas to review and comment on PSD permit applications that may show specific adverse impacts in a Class I

area. Such specific adverse impacts are determined relative to air quality related values (e.g., visibility) which may be defined by the FLM.

Through this special procedure set forth by Congress, FLM's have the authority to request that a permit application for a new ormodified source affecting Class I areas be denied or that additional controls be required, even if the source demonstrates that it will not

cause or contribute to a violation ofa Class I increment.

D. Selecting theForm forthePMo Increments

The levels of the equivalent PM1o increments that result from the 0equivalent to statutory increments" approach must initiallybear the same deterministic form as the statutory TSP increments. This means that (1)for the annual increments, the values are expressed as mean concentrations which cannot be exceeded in a single year, and (2) for the 24-hour increments, the values are 24-hour average concentrations which cannot be exceeded more than one time in a single year.In addition, the annual increments

are stated as geometric mean values.

In contrast, the PMo NAAQS are expressed in a statistical form. That is, the PMo annual NAAQS is an expected arithmetic mean concentration, while the PM0 24-hour NAAQS isa 24-hour average concentration forwhich a single expected exceedance per year is allowed. In the statistical form, the expected value is actually an average 

### value derived from several years of data, againstwhich the annual or 24- 

### hour NAAQS is compared. The prescribed method for calculating these expected values for the PMo NAAQS is contained in 40 CFR Part 50Appendix K.

In order to be completely consistent with the form ofthe PMo NAAQS, three separate conversions, involving three different conversion factors, would need
tobe made. Two ofthese conversion factors would be used to adjust the annual and 24-hour increments to the statistical form (each averaging time requires its own independent adjustment). The third conversion factor would be used to adjust from an annual geometric mean value to an annual arithmetic mean value (for the annual averaging time only).

The EPA believes that either the deterministic or statistical form would be acceotable as long as the numerical levels ofthe increments could be adjusted accordingly to retain their equivalent relationship to the statutory TSP increments. The EPAhas decided to propose theincrements in the deterministic form in order to eliminate the need for applying two of the conversion factors.This decision was based primarily on the difficulty that EPA would experience in attempting to replicate the source-by-source equivalency analyses which were conducted using deterministic source impact data in the NSR data base.

The EPA doesbelieve, however, that there is a practical need to establish the annual PMio increments as arithmetic

mean values instead ofthe geometric

mean values. Current EPA models are designed to compute arithmetic means, rather than geometric means. Furthermore, EPA believes thatmost PSD applications received to date by the States and EPA contain increment analyses in which the modeled predictions ofannual increases in concentrations ofTSP are based on arithmetic mean concentrations, rather than geometric mean concentrations.

The use ofan arithmetic mean value in predicting source impacts on air quality is generally acceptable, because it tends to yield a more conservative (higher] concentration estimate than the geometric mean concentration derived from the same setof data. However,

over time, unless EPA makes the conversion to an arithmetic mean value, PSD applications eventually will find it necessary to calculate their predicted air quality impacts as a geometric mean concentration. That is, as less available increment remains for additional emissions growth, use of the more conservative approach will no longer suffice for making compliance demonstrations.

To adjust to an arithmetic mean value. EPA used information that was developed from an analysis of 11,541 site-years ofTSP data (1975-1978) nationwide. The data were analyzed to determine, on a single year basis, the percent difference between the annual arithmetic mean and the annual geometric mean. The analysis indicated that the typical ratio (at the 50th percentile) was 1.12. In other words, the annual arithmetic mean was typically 12 percent higher than the annual geometric mean.

Accordingly, EPA is adjusting the equivalent annual PMo increments, derived from the statutory annual TSP increments (geometric), to arithmetic

mean values using the 50th percentile ratio of 1.12. The annual increments expressed as arithmetic means (rounded
to the nearest whole number) are as follows (with the equivalent PMo increment expressed as geometric

means inparentheses): Class I--4 Lg/

m3 PM 0 annual arithmetic mean (5 pgI

m3 annual geometric mean); Class 1- 17 pjg/m3 PM1oannual arithmetic mean (15 1AgJm 3 annual geometric mean); Class 111-34 jLg/m3 PM0 annual arithmetic mean (30 ig/m 3 annual geometric mean).

IV Implementation Issues.

A. Geographic Applicabilityof PMo Increments

On the applicable implementation date (see section IV.D.), the proposed PMio increments generally would apply everywhere. This is in accordance with 40 CFR 51.166(i)(3) [see also §52.21(i)(3)] which stipulates that the PSD review applied to any new major stationary

source ormajor modification thatwould
propose to locate in an area designated

as either attainment or unclassifiable for anypollutant.15 Only in the case ofan
area designated as nonattainment for all pollutants would the PSD requirements fail to apply to PMo. However, because

no such complete nonattainment area status currently exists, EPA has chosen
not to propose revisions to the regulatory framework applying PSD to PM 10. The EPAintends forthe PM 0 increments to apply in a manner consistent with the latest PSD area

15 Inaddition to the current area designations for TSP Statesare required under section 107 ofthe Act toidentify the attainment status forother criteria pollutants, including sulfur dioxide,nitrogen dioxide,ozone, and carbon monoxide. TheEPA maintains alisting ofall area designations in40 CFRPart81 Subpart C. 

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## / Vol. 54, No. 192 / Thursday October 5, 1989 

## / Proposed Rules

classifications, i.e, Class 1, 11, and III, which apply to the TSP increments proposed to be replaced. However, where an area waspreviously designated as nonattainment for TSP the Class IIPM1

### oincrements will apply unless the area is designated as a Class Iarea [see 40 CFR 51.166(e) and §52.21(e)]. States may redesignate area classifications forPMo in accordance with the redesignation procedures set forth under 40 CFR 51.166(g) [also §52.21(g)].

B.BaselineDatesandBaselineAreas

Under today's action, EPA is proposing its intention to retain the existing baseline dates and baseline

areas thathave already been established for particulate matter.The EPA believes thatit isnecessary to provide continuity with respect to the starting date formeasuring the particulate matter increments in order to

asure the "equivalence" concept that EPAhas selected for establishing the

new PMo increments. The major source baseline date, therefore, will continue to be January 6,1975, and the minor source baseline date will be the earliest date after August 7 1977 on which the first complete PSD application is submitted by a major source with significant particulate matter emissions.

The retention ofexisting baseline dates and baseline areas for particulate matter includes those established under EPA-approved State PSD programs, as well as the ones established under EPA's40 CFR part 52PSD regulations. Thus, once the new PMo increments are approved by EPA as part ofthe States' PSD SIP's, the amount ofPMo increment already used (ifthe baseline date has already been established forTSP)must be calculated in accordance with the baseline date established under the original TSPincrements. An established baseline date forTSPwould remain in effect even ifthe PSD source would not have triggered such datebased on its potential PMio emissions [see proposed

new paragraph (b)(14)(iv) under 40CFR 51.166 and § 52.21].



### Where the baseline date for particulate matter has not yetbeen established, it willbe the date after the applicable PMo increment implementation date on which the first complete PSD application is submitted by a majornew source ormajor modification having the potential for significant amounts ofPMo emissions. That is, EPA's policy willbe torequire that any new baseline dates for particulate matter under the PMio increments be established when the

source ormodification would have the potential to emit as least 15 tons per year ormore ofPMo emissions, (i.e., the significant emission rate defined for PM~o), rather than 25 tons per year or

more ofparticulate matter emissions. See further discussion ofhow the two different significant emission thresholds will be applied m the following section, "Source applicability.

Baseline areas that are established after the implementation date for the

new PM1o increments mustinclude the "PSD area" in which the proposed

source ormodification would be located and any other "PSD area" ifiwhich the

source ormodification would have an ambient PMo impact ofat laest ljtg/m3 (annual average). The PSD areas referred to would iritally be circumscribed by the geographic boundaries which the States set forth to define the section 107 attainment designation status (including nonattainment) forTSP These boundaries are listed as the "designated area" under Subpart C of40 CFR part 81.

As mentioned earlier in this preamble, EPA plans to automatically delete the applicable attainment status designations for TSPwhen the equivalent PMo increments are in place in a State's SIP In doing so, EPA will retain references to the geographic boundaries ("designated areas") associated with the designations. These "designated areas, including the ones previously holding a TSP nonattainment designation, will then be listed in Subpart C as PSD areas for PMo. It shouldbe noted, however, that the "automatic" deletion ofan area's TSP designation from 40 CFR part 81 will

occur only after a PM,o SIPproviding for implemention ofthe PMo NAAQS has been approved, orEPA promulgates a substitute Federal plan. Ifsuch a revised PM

1 *o SIP has not been approved, EPA will need to retain the TSP area designation, even though it is revising part 81, as described above, to list the

area boundaries for purposes of identifying PMo baseline areas. Ultimately, EPA anticipates that all TSP

area designations will be removed and the "designated areas" associated with them willbecome PSD areas for determining PMo increment baseline

areas.

The EPA is also proposing to revise the definitions of "baseline area" and "baseline date" inparts 51 and 52 to account for the new PSD area listings for PMo. Since the PSD areas for PMio will have no direct linkage to the section 107 area process, language is proposed
to be added to the definitions of "baseline date" and "baseline area" to refer specifically to the PSD areas for PMio as they are listed in Subpart C of 40 CFR part 81 [see proposed revisions
to 40 CFR 51.166(b) (14) and (15), and §52.21(b) (14) and (15)].

C.SourceApplicability

Only "major stationary sources" and "major modifications" (i.e., major stationary sources incurring a significant
net increase in emissions) are subject to PSD review. A major stationary source is defined in 40 CFR 51.166(b)(1)(i) as any stationary source that emits, or has the potential to emit, a threshold amount ofpollution for "any pollutant subject to regulation under the Act. For sources in
any one of28 specified source categories, that threshold is 100 tons or

more per year; for all other sources, the threshold is 250 tons ormore per year.

The EPA believes that the determination ofwhether a source is a major stationary source should continue
to be based on potential "particulate
matter emissions, 16 since particulate
matter emissions continue to be regulated under a variety ofsection 111

new source performance standards. (See 40 CFR part 60 etseq.) For the reason, EPA does not intend to change the way in which a new source is determined to be "major" forparticulate matter.

Similarly, EPA does not intent to make any changes to the emission rates which define "significant" for particulate matter. That is, significant
amounts ofparticulate matter will continue to be calculated in terms of both particulate matter emissions and PMo emissions. Accordingly, anew stationary source which has the potential to emit any pollutant in major
amounts will be subject to PSD for particulate matter,ifsuch major stationary source would emit significant
amounts ofeither particulate matter emissions (25tons per year) orPMo emissions (15 tons per year). An existing major stationary source will also be subject to PSD review if, after accounting for creditable emissions increases and decreases caused by a modification, a significant net emissions increase ofeither particulate matter emissions orPMo emissions is determined to result.

Under today's proposal, itwill be EPA s policy to require any PSD source which would have the potential to emit significant amounts ofeither particulate
matter emissions orPMo emissions to undergo PSD review. However, in

16 "Particulate matter emissions" are defined as all finely divided solid orliqmd material, other than uncombined water,emitted tothe ambient air as measured byapplicable reference methods, or an equivalent or alternative method, specified by EPA

orby a test method inan approved SIP [40CFR 51.100 (pp)]. 

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### Federal Register / Vol. 54, No. 192 / Thursday, October 5, 1989 / Proposed Rules

completing this review, a PSD applicant would only be required to perform an ambient impact analysis (NAAQS and PSD increments) for particulate matter when the proposed new source or modification would have the potential to emit PMo emissions in significant
amounts.
D.ImplementationDate

There are several important time periods specified by section 166(b) of the Act that will affect the implementation ofthe increments for PMo. First,'a 1-year time period is required by section 166(b) between the date ofpromulgation ofsection 166 regulations and the effective date of such regulations. Second, section 166(b) of the Act also provides States up to 9 months following the effective date of promulgation ofthe new regulations to prepare necessary amendments to SIP's, and an additional 4months (13 months total) forEPA to review the proposed SIPrevisions prior to determimng their approvability. Consequently, a periodof up to 25 months (12 months from promulgation to the effective date, plus 13 months for SIPapproval) could elapse between the promulgation of these increments and their implementation. Until the actual implementation date ofthe new PMlo increments in any State's PSD SIP the TSPincrements will continue to apply.

The actual'time that elapses between promulgation and implementation depends on two factors: (1) The mechanism by which the PSD program is implemented in an area, and (2) the action a State or area takes to enable it
to implement the program. There are three mechanisms by which the PSD program is implemented. First,a State

can have its own PSD permitting procedures that have been approved by EPA as meeting the requirements of40 CFR 51.166; this is termed an EPAapproved PSD SIPprogram. Second, a State can receive a delegation ofEPA's authority to issue PSD permits in accordance with the Federal PSD regulations in 40 CFR 52.21; this is termed a delegated PSD program. Finally, in a few areas ofthe country where States have neither submitted an approvable PSD SIPnor sought a delegation, and in Indian lands where States lack authority to administer the PSD requirements, EPA Regional Offices issued PSD permits pursuant to 40 CFR 52.21.

ForEPA-approved programs, section 166(b) ofthe Act contemplated a 40 CFR 51.166 rule thatwould take effect 12 months after promulgation and allow States 9 months after that (21 months afterpromulgation) to submit revised SIP's incorporating the increments. The EPA was then expected to approve or disapprove the SIPrevision within 4 months, so the maximum time anticipated for implementation in SIPapproved areas is 25 months. The EPA will follow this schedule for the PMo increments. Each State or area with an EPA-approved PSD program will have until 21 months after promulgation ofthe increments to submit to EPA a SIP revision implementing them. Revised SIP's may, ofcourse, be submitted earlier,'but EPA cannot approve any such revisions until 12 months after the date ofpromulgation ofthe PMo increments under § 51.166.

For States that currently lack approved PSD plans, and forIndian lands, EPA proposes a similar implementation schedule for the PMo increments and associated regulations. The EPAbelieves that it should follow the language ofsection 166 to the greatest extentpossible in establishing implementation dates for these areas. Specifically, section 166(b) provides up to 21 months from the date of promulgation ofsection 166 regulations for States to submit SIPrevisions to EPA for approval. The EPAbelieves it appropriate to provide each State an opportunity to develop an EPAapproved PSD SIP program. For this
reason, every State will be provided 21 months in which to develop and submit

a revised SIPfor PSD, including any PMo increments ultimately promulgated pursuant to today's proposal. This approach should also minimize differences in implementation dates between the States due to differences in PSD program mechanisms. The EPA proposes to establish a general effective date of25 months after publication of the final notice for the PMlo increments and associated regulations promulgated pursuant to § 52.21.

It should be noted, however, that as events actually unfold over that 25- month period, the implementation date forthe PMo increments could occur in

some SIP's at times other than the generally applicable effective date. First,

a State might adopt and submit the necessary SIP revisions (perhaps as part ofa comprehensive PSD permitting program), and EPAmight approve them, all between the 12-month and 25-month points. Second, EPA might advance the general effective date in the case where

a State stipulates, in writing, that it does
not intend to submit the necessary SIP revisions (thereby rejecting the 21- month SIP development time provided in the Act), and requests that EPA delegate
to it (i.e., the State) the administration of the PMo increments in lieu ofthe TSP increments currently contained in §52.21. Similarly, ifan Indian tribe requests in writing an earlier effective date, EPA will consider advancing the effective date in accordance with the tribe's wishes. The EPA will make a case-bycase judgment based on all of the circumstances at the time ofthe request. The EPA would in no event make those amendments effective any earlier than the 12-month point established for the amendments to §51.166.

E. Grandfatherng Provisins

The EPA anticipates that the Agency and the States will receive numerous PSD permit applications, which contain

a TSP increment analysis, before the applicable implementation date of the PMo increments. In cases where these applications are considered to be complete based on the existing requirements on the date that they were submitted, yet a permit has not yet been issued by the reviewing authority, EPA believes thatit would be appropriate to exempt the applications from any PMo increment analysis and requirements. In order toprovide for such exemptions, EPAis proposing to add grandfathering provisions to the PSD regulations under both part 51 and part 52. The new provision would apply only as to consideration ofthe PMo increments. Any SIPrequirements already in effect forPMo (e.g., PMlo NAAQS compliance), before the implementation date of the PMo increments must be met

as provided for in the existing PSD program.

For applications submitted under EPA'spart 52 PSD regulations, the Agency is proposing agrandfathering provision at § 52.21(i)(13). This paragraph states that the amendments requiring a PMo increment analysis would not apply to any project forwhich

a complete application has already been filed, including a project that has already received a permit before the implementation date ofthe relevant amendments to § 52.21, Instead, such projects would be reviewed only for their ability to demonstrate compliance with the originalTSP increments.

The EPAis also proposing to add a parallel grandfathering provision under part 51 that would allow a State to enact

a similar exemption under it's SIPapproved program. In the case ofa State's own PSD requirements, the exemption would be based on the submission of a complete PSD permit application before the State's implementation date for the PMo increments [see proposed new, paragraph (i)(12) under §51.166]. Of

course, a State would be free to have a

more restrictive exemption, or no 

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### Federal Register / Vol. 54, No. 192 / Thursday, October 5, 1989 / Proposed Rules

exemption at all, ifit deemed any such alternative course ofaction more appropriate.

F.Exclusions from Increment Consumption

Section 163(c)(1) of the Actprovides that States With EPA approved PSD plans may "issue orders or promulgate rules" to exclude concentrations from certain emission-related activities in determining compliance with the PSD increments. When States revise their SIP's to adopt the new PMo increments, they may adopt exclusions for certain concentrations ofparticular matter, which had not been previously considered forthe TSP increments [see 40 CFR 51.166(0 ]. "Prescribed burning" is an example of the types ofactivities for which an exclusion might be sought.

"Prescribed burning" is a term for a wide variety of silvicultural, agricultural, industrial, and commercial practices involving the burning of vegetative materials. Prescribed burning is done for a variety ofreasons, including wildlife and vegetation management; fire suppression; disposal oflogging, agricultural, and other wastes; site preparation; land clearing; timber standmanagement; and range (forage] management. Certain ofthese activities, such as the burmng ofdebris
to construct a highway (landclearing), might be considered to be temporary in that the emissions would only degrade air quality in any affected area fora short time (the duration ofthe construction project). However, certain other activities, which may represent

common and routine practices, might not be considered to be temporary since they contribute to measured air quality levels on a regular basis. Suchperiodic burning might be considered an intermittent, but not necessarily temporary, activity.

Section 163(c)(3) ofthe Act calls for

an EPA determination that any State rule or order providing for the exclusion ofcertain pollutant concentrations from PSD increment consumption complies with the statutory exclusion provisions. The EPA will give serious consideration
to a State exclusion provision for specific temporary PM 1oemissionrelated activities fromPMo increment consumption, provided that any such provision would not result in permanent

orlong-term deterioration ofair quality in any affected area. For example, some logging, agricultural, and silvicultural activities could betterbe described as "itinerant" activities in that they mav be temporary at a specific location. but

move to nearoy locations and still'affect the air quality within the same air shed. The EPA is also soliciting comments regarding (1) whether exclusions should be contingent upon the use ofspecific mitigation measures as "best management practices"- (2)what, ifany, accountability measures should be required regarding the temporary nature ofair quality deterioration resulting from excluded activities; and (3) whether excluded activities should be "coordinated" or "scheduled" when occurring in a common air shed to minimize the ambient impact from all excluded activities on a given day.

As stated above, the Act allows only those States with approved PSD plans to establish certain exclusions from increment consumption. While the types ofexclusions that States may establish

are described under paragraph (f) of § 51.166, EPA's current part 52 PSD Regulations also contain similar exclusion provisions [see § 52.21(f)]. The EPA originally allowed States to request the use of the exclusion provisions underEPA's part 52 PSD program while States were developing their own initial PSD regulations. But the EPA indicated that, after May 7, 1981, the exclusions would be unavailable unless a State submitted an approvable PSD plan to EPA (see 45 FR 52676, August 7 1980; p. 52719). Paragraph 

### (f) of § 52.21 is superfluous, since States may no longer request the exclusion ofcertain particulate matter concentrations from the PM1oincrements under EPA's part 52 PSD regulations. Consequently, EPA plans to eliminate paragraph (f) altogether to avoid any confusion as to its future use by States without EPAapproved PSD plans. Accordingly, EPA is proposing to delete and reserve paragraph 

### (f) of § 52.21. EPA is also proposing to delete paragraph (f0(3) of §51.166 which states: "No exclusion under paragraph (f) of this section shall occur laterthan 9 months after August 7 1980, unless a SIP revision meeting the requirements of40 CFR 51.166 has been submitted to the Administrator. The original purpose of this provision was to restrict the use of the exclusion provisions under EPA s Part 52 PSD regulations beyond May 7 1981. Therefore, inorder to avoid any confusion concerning the States' continuing authority to adopt new exclusion provisions pursuant to section 51.166, EPA is today proposing to delete paragraph (f)(3) ofthat section.

G. Areasourceimpacts
Afterthe baseline date, emissions from area sources must be considered in the increment consumption calculations. An analysis was conducted todetermine the potential impact ofemissions from

area sources on the consumption (or expansion) ofPMo increments. A detailed report is provided inthe docket for public inspection. Basically, this analysis focused on emissions from
motor vehicles andresidential wood combustion (RWC) in high growth urban

areas. The potential impacts ofother

area sources on PMo increments were determined to be less than their potential impact on the existing TSP increments, because their ratios ofPMio emissions to particulate matter emissions were sufficiently low.

Ifarea sources make a significant contribution to ambient PMo concentrations after the establishment ofthe baseline date, these sources would consume the PM~o increment and, consequently, constrain new or modified

source growth in PSD areas. If, on the otherhand, emission controls on area

sources result in reductions in emissions of PM10, these controls may effectively expand the increment and reduce the constraints posed by the PSD regulations on new and modified source growth.

H. Preventionofsignificant deterioration monitoring

In conjunction with EPA s proposed deletion of the TSP-based increments, EPAis also proposing to eliminate the requirement that PSD applicants submit preapplication monitoring data for TSP

as part oftheir permit applications. This would be accomplished through the deletion ofthe significant ambient concentration defined forTSP [see revised paragraph (i)(8)(i)(c) of40 CFR 51.166; also §52.21(i)(8)(i)]. The existing significant ambient concentration of10 pg/m3 ofTSP 24-hour average, was originally established to help determine when a proposed PSD source must, prior
to the submittal of its PSD application, collect and evaluate ambient TSP data in accordance with paragraph (in) ofthe PSD requirements under §§ 51.166 and 52.21.

When EPA amended the PSD requirements on July 1, 1987 to account for the revised PMo NAAQS, it added a significant ambient concentration for PMo (10 j.g/m s 24-hour average). This significant ambient concentration is used to help determine when application monitoring data forPM1omust be gathered. The EPA indicated, however, that TSPmonitoring would continue to be required under the PSD program (52 FR 24686). Once the TSP increments are deleted in accordance with the applicable,implementation date for the PMo increments, PSD programs will no longer require the regulation ofTSPas
an ambient indicator for particulate
matter. Consequently, EPA will not 

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### Federal Register / Vol. 54, No. 192 / Thursday, October 5, 1989 / Proposed Rules

require PSD applicants to submit preapplication monitoring data forTSP when today's proposed amendments become effective under the Part 52 PSD regulations; only PM10 monitoring data will be required where applicable. When today's proposed amendments become effective under 40 CFR part 51, the requirement forpreapplication monitoring data for TSPwill no longer exist in the Federal SIPrequirements for PSD.

V Summary ofProposed Changes to the Regulations

In order to incorporate the PMo increments and other changes discussed above into the PSD regulations, EPA is proposing amendments to several provisions of the CFR. Most ofthe changes are to existing provisions under both part 51 and part 52 ofChapter40 of the CFR, pertaining to requirements for State and Federal administration ofthe PSD program, respectively. The EPA is also proposing to add a new Subpart C under part 81 ofChapter 40, as further described below.

One important proposed revision to the PSD regulations is the establishment ofPMo increments and the deletion of the existing TSP increments. In accordance with today's proposal the PMo increments would be added to the tables in §§ 51.166(c) and 52.21(c) which define increments for Class I, II, and III

areas. Similarly, EPA proposes to amend the tables in 40 CFR 51.166(p) and §52.21(p) by adding new increments for PMo. The increments contained in these latter tables apply in situations where the FLM determines that a source will exceed the PMo Class I increments 

### (in a Class I area) without adversely affecting the area's air quality-related values. In all of these tables, the TSP increments would be deleted upon the effective date of the amendments to the increments for particulate matter. Other changes to the PSD regulations are necessary to account for the new PMio increments and the deletion ofthe TSPincrements. First, a sentence is proposed to be added to §§ 51.166(b)(3)(iv) and 52.21(b)(3)(iv) to make it clear that only reductions in PM 10 can be used to offset

new emissions ofPMo in determining the net emissions increase created by a
new ormodified facility subject to the PSD program.

Second,EPA proposes to modify the definitions of "baseline date" and "baseline area" to make it clear that baseline dates and baseline areas will be retained under the PMio program, just

as they existed under the existing particulate matter PSD regulations. That is, ifan area has a baseline date under the existing particulate matter (TSP) 

### increment, that same area andbaseline date will be applicable to thePM1

### o regulations. Ifan areahas no existing baseline date for particulate matter,the first complete PSD application with significant PMo emissions filed with the appropriate reviewing authority after the implementation date ofthenew PMio increments will trigger thebaseline date. Also, because requirements for designating area attainment status pursuant to section 107 oftheAct do not apply to PM~o, the definitions of "baseline date" and "baseline area" are proposed to be amended to refer to the PSD areas forPMio thatwill be listed in subpart Cof40 CFR part81.

Paragraph (f)(3) of§51.166 isproposed
to be deleted and reserved in order to avoid confusion as to a State's authority to develop and request EPA approval for

new exclusion procedures for PSD increments. The elimination of paragraph (f)(3) will clarify EPA's position that any State with anEPAapproved PSD planmay request exclusions. Also, the entire paragraph (f) ofsection 52.21 is proposed to be deleted and reserved because States are
no longer able to request the exclusion of certain concentrations in determining compliance with the PSD increments under §52.21.

ThePSD requirement for preapplication monitoring forTSP is proposed to be eliminated by deleting the significant ambient concentration for TSP from the listofpollutants contained in §§51.166(i)(8)(i) and 52.21(i)(8)(i). 

### Thereafter, the PSD monitoring requirement for particulate matter will apply onlyto the PMi

### oindicator.

A new grandfathering provision is being proposed under §§51.166(i)(12) 

### and 52.21(i)(13) to enable certain permit applications, ifsubmitted before the effective date ofthe amended regulations, to be exempted from the

new requirement for a PM10

### increment analysis.

Finally, Subpart C to 40 CFR part 81 is proposed to be amended. Anew paragraph will be added to explain how the section 107TSP area designations willbe deleted from each State listing so that PMobaseline areas can be established when the PMio increments become operative In each SIP

VI. Admimstrative Requirements.
A. Public Hearing 

### Ifrequested, a public hearingwill be held to discuss theproposed regulations in accordance with section 307(d)(5) of theAct. Persons wishing to make oral presentations should contact EPA at the address given in the ADDRESSES section 

### ofthis preamble. Ifnecessary, oral presentations willbe limited to 15 minutes each. Any member of thepublic may file a written statement with EPA before, during, or within30 days after thehearing. Written statements should be addressed to theAir Docket address given in the ADDRESSES 

### section of this preamble.

A verbatim transcript ofthe hearing and written statements willbe available for public inspection and copying dunng normal working hours at EPA'sAir Docket inWashington, DC (see
ADDRESSES section 

### ofthis preamble).

B. Docket



### The docket forthis regulatory action is A-88-19. The docket is an organized and complete file of all theinformation submitted to, orotherwise considered by,EPA in the development ofthis proposed rulemaking. The principal purposes ofthe docket are: (1)To allow interested parties a means to identify and locate documents so that they can effectively participate in the rulemaking process, and (2)to serve as the record in

case ofjudicial review (except for interagency review materials). [see section 307(d)(7)(A)]. The docket is available forpublic inspection at EPA's Air Docket,which is listed under the
ADDRESSES 

### section ofthisnotice.

C.ReferenceDocuments

1.Radian Corporation. Technical ReportEquivalency ofAlternative PMo Increments. Prepared for U.S. Environmental Protection Agency. Office ofAir Quality Planning and Standards. Research Triangle Park, NC. March, 1988.

2.Radian Corporation. Cost and Economic Impact Assessment for PM 1oIncrement Options. Prepared for U.S.Environmental Protection Agency. Office ofAir Quality Planning and Standards,Research Triangle Park.NC. April, 1988.

3.Shumaker, J.L, Radian Corporation (1988). Evaluation ofSource Impacts Associated with PMo Increment Options. Memorandum to Daniel J.deRoeck. Feburary 15. 1988.

4. Pandullo, R.F. Radian Corporation (1988). Protection Against Adverse Class ITSP Impacts Affordedby PM1 oIncrements. Memorandum to Daniel J.deRoeck. September 28,1988.

5.Frank, Neil H., U.S. EPA,Monitoring and Reports Branch. Difference Between Arithmetic Mean and Geometric Mean TSP Memorandum to lohn Bachman andHenry Thomas. June 2,1980.

6. Frank, Neil L,U.S. EPA, Data Analysis Section (1984) Update on the Difference Between Arithmetic and Geometric Means for TSP Memorandum to John Bachman. September 1,1983.

7 Tikvart, JosephA., U.S. EPA, Source Receptor Analysis Branch (19891. Comparison ofModel Estimates for Deterministic vs. Statistical Standards. Memorandum to Edward J.Lillis.April 4,1989. 

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### Federal Register / Vol. 54, No. 192 / Thursday, October 5, 1989 / Proposed Rules

8.Radian Corporation. PM 0 Area Sources Paper.Prepared for U.S. Environmental Protection Agency. Office of AirQuality Planningand Standards. Research Triangle Park, NC. February 1988.

9. Revisions to the National AmbientAir Quality Standards for Particulate Matter (52
FR24634).

10.Air Programs. Review of the National Secondary AmbientAir Quality Standards for Particulate Matter (52FR 24670).July 1, 1987

11.Regulations for Implementing Revised Particulate Matter Standards [52 FR24672). July 1,1987

12. Proposed Regulations for Implementing Revised Particulate Matter Standards (50 FR 13130). April 2, 1985.

13. Proposed Revisions to the National Ambient Air Quality Standards for Particulate Matter (49FR 10408).

14. Regulations for the Prevention of Significant Deterioration ofAir Quality (45 FR 52676). August 7 1980.

D. Officeof ManagementandBudget (OMB)Review

Under Executive Order 12291 (E.O. 12291), EPAmust judge whether a regulation is "major," and therefore subject to the requirement ofa Regulatory Impact Analysis. The EPA performed an economic impact
assessment using conservative costing assumptions to assess whether the proposed PMo increments would constitute a major rule. Theresults of this assessment indicate that the proposed regulation is not major, because itwould result in none ofthe adverse economic effects set forth in section I ofE.O. 12291 as grounds for finding a regulation to be major.The annualized costs in the fifth year after the proposed regulations would go into effect would be $5 million, well under the $100 million threshold established as the first criterion fora major regulation in E.O. 12291. Estimated price increases of0.3 to 1.5 percent associated with the proposed regulations would not be considered a "major increase in costs or prices" specified as the second criterion in E.O. 12291. The economic analysis of the proposed regulations' effect on the industry did not indicate any significant adverse effect on competition, investment, productivity, employment, innovation, or the ability ofU.S. firms to compete with foreign firms [the third criterion ofE.O. 12291).

This regulation was submitted to OMB for review as required by E.O. 12291. Any written comments from OMB
to EPA. and any EPA responses to those comments, will be included inDocket A-88-19.

No additional reporting and recordkeeping requirements will occur

as a result oftoday's proposed regulatory revisions. The EPA previously addressed significant changes to the recordkeeping and reporting-requirements, which resulted from new requirements for PMlo in the Federal PSD and NSR regulations, amended July 1, 1987 (52FR 24672). Those changes were submitted to OMB for approval under the Paperwork Reduction Act of1980,44 U.S.C. 3501 et
seq.Today's proposed revisions focus primarily on the replacement ofthe existing TSPincrements with equivalent PM 0 increments for the prevention of significant deterioration. There will not be a time when both sets of increments willbe federally required simultaneously.

E.Federalism Implications

Under Executive Order 12612 [E.O. 12612), EPA must determine ifa rulehas federalism implications. Federalism implications refer to substantial direct effects on the States, on the relationships between the national government and the States, or on the distribution ofpower and responsibilities among the various levels ofgovernment. For those rules which have federalism implications, a federalism assessment is to be made.

E.O. 12612 also requires that agencies,
to the extent possible, refrain from limiting Statepolicy options, consult with States prior to taking any actions that would restrict State policy options, and take such actions only when there is clearconstitutional authority and the
presence ofa problem ofnational scope. E.O. 12612 provides for preemption of State law, however, ifthere is a clear congressional intent for EPA to do so. Any such preemption, however, is to be limited to the extent possible.

The development ofsection 166 regulations for PMo is a statutory, nondiscretionary duty. However, States
may adopt strategies other than increments for PMo under section 166, if the strategies, taken as a whole, accomplish the statutory purposes. In addition, the regulations that EPA is proposing will allow States a full opportunity to develop their own approvable methods ofimplementing the proposed increments. Finally, the EPA will implement its own regulations only for those States that do not develop their own approvable regulations. Congressional intent forpreemption of State law is clear in such cases.

State comments on the proposal will be fully considered prior to promulgation offinal rules. For these

reasons, a federalism assessment has
not been prepared. F EconomicImpactAssessment
Section 317 ofthe Act requires the Administrator to prepare an economic impact assessment for any regulations under part C ofTitle I [relating to PSD of air quality). An economic impact
assessment was prepared for the proposed PM1oincrement levels and also for other alternative levels. The requirements oftins section were considered in the formulation of the proposed increments to ensure that they would represent the best system for the prevention of significant deterioration of air quality, considering costs.The economic impact assessment is included in the docket.

G. RegulatoryFlexibility Act Compliance

Pursuant to the provisions ofU.S.C. 605(b), I hereby certify that this rule, if promulgated, will not have a significant economic impact on a substantial number ofsmall business entities (see 46 FR 8709).

List ofSubjects
40CFRPart 51

Air pollution control, Intergovernmental relations, Particulate matter, Total suspended particulate, PM3o.
H.Paperwork ReductionAct

Under the Paperwork Reduction Act (44 U.S.C. 35.01 et seq)Federal Agencies
must obtain OMB clearance for collection ofinformation from ten (10) or

more non-federal respondents. This rule does not contain any collection information requirements.

40 CFRPart 52

Airpollution control, Particulate matter, Total suspended particulate, PM1o.
40 CFRPart 81

Air pollution control, National parks, Wilderness areas.

Dated: September 22, 1989. William K.Reilly, Administrator.

PART 51-REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS

Forthe reasons set forth in the 

### preamble, it is proposed that part 51, 

### Chaper I,Title 40 ofthe Code ofFederal 

### Regulations. be amended as follows:

1. The authority citation forpart 51 continues to read as follows:

Authority: Secs. 101(b)(1), 110, 160-169, 171-178. and 301(a) ofthe Clean Air Act;42 

### 41L230

### Federal Register / Vol. 54, No. 192 / Thursday, Oct6ber 5, 1989 / Proposed Rules

U.S.C. 7401(b)(1), 7410, 7470-7479, 7501-7508, and 7601(a).

2. In § 51.166, paragraphs (b)(3)(iv), (b)(14)(iii)(a), and 

### (b)(15)(i), the first part ofparagraph (b)(15)(ii) ending with the word "which, paragraph (i){8)(i)(c), the tables in paragraph (c) and paragraph (p)(4) are revised; paragraph (f)(3) is removed and reserved; and paragraphs (b}{14)(vi), (b)(15)(iii), and (i)(12) are added to read as follows: §51.166 Prevention of significant deterioration of air quality.



### (b) (3) (iv)An increase or decrease in actual emissions ofsulfur dioxide, particulate matter, ornitrogen oxides, which occurs before the applicable minor source baseline date is creditable only ifit is required to be considered in calculating the amount ofmaximum allowable increases remaining available. With respect to particulate matter, only PMo emissions can be used to evaluate the
net emissions increase forPM 1e.
(14) (iii) (a)The area m which the proposed

source ormodification would construct is designated as attainment or unclassifiable for sulfur dioxide or nitrogen dioxide under section 107(d)(1)(D) or (E) of the Act, or is listed for PMo under 40 CFR part 81 Subpart C, on the date ofits complete application under 40 CFR 52.21 or under regulations approved pursuant to 40 CFR 51.166; and

(iv) Any baseline date established for

an increment for particulate matter shall remain ineffect and shall apply to any change in the applicable ambient indicator for particulate matter.

(15)(i) "Baseline area" means any intrastate area (andevery part thereof) either designated as attainment or unclassifiable for sulfur dioxide or nitrogen dioxide under section 107(d)(1) (DI or (E) ofthe Act,or listed for PMo under 40 CFR pai 81 Subpart C, in which the major source ormajor modification establishing the minor

source baseline date would construct or would have an air quality impact equal
to or greater than ug/m3 (annual average) ofthe pollutant(s) forwhich the baseline date is established.

(ii) The redesignation ofan attainment

orunclassifiable area for sulfur dioxide

or nitrogen dioxide under section 107(d)(1) (D) or 

### (E) of the Act, or ofan

area listed for PMo under 40 CFR part 81 Subpart C,cannot cause such 

### redesignated area to intersect or be smaller than the area ofimpact ofany major stationary source ormajor modification which:

(iii) Any baseline area established for

an increment forparticulate matter shall remain in effect and shall apply to any change in the annlicable ambient indicator forparticulate matter, except that Auch area may beredesignated in accordance with paragraph (b)(15)(ii) of this section.

(c)

Maximum allowable increase Pollutant (micrograms per

cubic meter)

Class I:

Particulate matter:

PM0, annual arithmetic mean

........... 4 PM,0,24-hr maximum

......................... . . Sulfur dioxide:

Annual arithmetic mean

.................. . 2 24-hr maximum

.................................... 5 3-hr maximum

..................................... 25 Nitrogen dioxide:

Annual arithmetic mean

...................... 2.5

Class II:

Particulate matter.

PMo, annual arithmetic mean

.......... 17 PMo,24-hr maximum

........................ 30 Sulfur dioxide:

Annual arithmetic mean

.................... 20 24-hr maximum

................................... 91 3-hr maximum

...................................... 512 Nitrogen dioxide:

Annual arithmetic mean

.................... 25

Class III:

Particulate matter:

PMo, annual arithmetic mean

........... 34 PMI0,24-hr maximum

........................ 60 Sulfur dioxide:

Annual arithmetic mean

.................... 40 24-hr maximum

................................... 182 3-hr maximum

...................................... 700 Nitrogen dioxide:

Annual arithmetic mean

.................... 50



### (f) (3) [Reserved] 

### fi} (8) (i) (c)Particulate matter-10jg/m3 of PMo, 24-hour average.

(12) The planmay provide that the permitting requirements equivalent to those contained in paragraph (k)(2) of this section shall not apply to a stationary source or modification with respect to any maximum allowable increase for PMo if 

### (i) the owner or operator ofthe source

ormodification submitted an application for apermit under the applicable permit program approved under the Actbefore the provisions embodying the maximum allowable increases for PMo took effect

aspart ofthe plan, and

(ii) the permitting authority subsequently determined that the application as submitted before that date was complete.

Instead, the applicable requirements equivalent to paragraph (k)(21 ofthis section shall apply with respect to the maximum allowable increases for TSP

as in effect on the date the application

was submitted.



### (p) (4)

Maximum allowable increase Pollutant (micrograms per

cubic meter)

Particulate matter.

PM,, annual arithmetic mean
............... 17 PM,0,24-hour maximum

....................... 30 Sulfur dioxide:

Annual arithmetic mean
........................ 20 24-hr maximum

....................................... 91 3-hr maximum

.......................................... 325 Nitrogen dioxide:

Annual arithmetic mean
........................ 25

PART 52-APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS

For the reasons set out in the preamble, itis proposed that Part 52, Chapter I,Title 40 ofthe Code ofFederal Regulations, be amended as follows:

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

Authority: 42 U.S.C. 7401-7642.

2. 

### In § 52.21, paragraphs 

### (b)(3)(iv), (b)(14)(iii)(a), (b)(15)(i), the firstpart of paragraph (b)(15)(ii) ending with the word "which, the tables in paragraph (c)and paragraph (p)(5), and the third itemin paragraph (i)(8)(i) are revised; paragraph (f)is removed and reserved; and paragraphs (b)[14)(iv), (b)(15)(iii), and (i)(13) 

### are added to read as follows:

§52.21 Prevention ofsignificant deterioration of airquality.



### (b) (3) (iv) An increase ordecrease in actual emissions ofsulfur dioxide, particulate matter, ornitrogen oxide, which occurs I I 

### 41231