### Federal Register/ Vol. 73, No. 54/Wednesday, March 19, 2008 /Rules and Regulations

Issued in Washington, DC, on March 7, 2008. James J.Ballough, Director, FlightStandards Service. Adoption ofthe Amendment

0 Accordingly, pursuantto the authority delegated to me, under Title 14, Code of Federal Regulations, part 97 (14 CFR part 97) is amended by establishing, amending, suspending, or revoking Standard Instrument Approach Procedures and/or TakeoffMinimums and/or Obstacle Departure Procedures effective at 0901 UTC on the dates specified, as follows:

PART 97-STANDARD INSTRUMENT APPROACH PROCEDURES

N 1. The authority citation for part 97 continues to read as follows:

Authority: 49U.S.C. 106(g), 40103, 40106, 40113,40114,40120,44502,44514,44701, 44719,44721-44722.

* 2. Part 97 isamended to read as. follows: Effective 10Apr2008 Blytheville, AR, Arkansas Intl, RNAV (GPS)

RWY 18, Amdt 1. Blytheville, AR, Arkansas Intl, RNAV (GPS)

RWY 36, Amdt 1. Blytheville, AR, Arkansas Intl, Takeoff

Minimums and Obstacle DP, Orig. Chicago, IL, Chicago Midway Intl, Takeoff

Minimums and Obstacle DP, Amdt 10. Wichita, KS, Wichita Mid-Continent, Takeoff

Minimums and Obstacle DP, Orig. Coldwater, MI, Branch County Memorial,

RNAV (GPS) RWY 7, Amdt 1. Coldwater, MI, Branch County Memorial,

RNAV (GPS) RWY 25, Orig. Coldwater, MI, Branch County Memorial,

VOR RWY 7, Amdt 5. Coldwater, MI, Branch County Memorial,

VOR/DME RWY 25, Orig. Coldwater, MI, Branch County.Memorial,

VOR RWY 25, Orig-A, CANCELLED. Coldwater, MI, Branch County Memorial,

TakeoffMinimums and Obstacle DP,Amdt 4. Jackson, MN, Jackson Muni, NDB RWY 13,

Amdt 10. Higginsville, MO, Higginsville Industrial

Muni, RNAV (GPS) RWY 16, Amdt 1. Higginsville, MO, Higginsville Industrial

Muni, RNAV (GPS)RWY 34, Amdt 1. Tulsa, OK, Tulsa Intl, VOR OR TACAN RWY

26, Amdt 23. Antigo, WI, Langlade County, RNAV (GPS)

RWY 16, Amdt 1. Antigo, WI, Langlade County, RNAV (GPS)

RWY 34, Amdt 1. Antigo, WI, Langlade County, NDB RWY 16,

Amdt 6. Antigo, WI, Langlade County, Takeoff

Minimums and Obstacle DP, Orig. Milton, WV, Ona Airpark, TakeoffMinimums

and Obstacle DP, Amdt 2. Effective 05Jun2008 Meeker, CO, Meeker, TakeoffMinimums and

Obstacle DP, Amdt 1. Telluride, CO, Telluride Rgnl, Takeoff Minimums and Obstacle DP, Amdt 1. Bartow, FL,Bartow Muni, TakeoffMinimums

and Obstacle DP, Orig. Bozeman, MT, Gallatin Field, NDB RWY 12,

Amdt 5, CANCELLED. Redmond, OR, Roberts Field, NDB OR GPS

RWY 22, Amdt 1A, CANCELLED. Ephrata, WA, Ephrata Muni,Takeoff

Minimums and Obstacle DP, Amdt 2. OnFebruary 25, 2008 (73 FR 9935), the FAA published an Amendment inDocket No. 30593, Amdt No. 3256 to Part 97 ofthe Federal Aviation Regulations under section 97.33, effective April 10, 2008, which is hereby rescinded: Lanai City, HI, Lanai, ILS OR LOC RWY 3,

Orig-A. On-February 25, 2008 (73 FR 9935), the FAA published Amendments in Docket No. 30593, Amdt No. 3256 to Part 97 ofthe Federal Aviation Regulations under section 97.33, effective April 10, 2008, which are hereby corrected to beeffective March 13, 2008: Bishop, CA, Eastern Sierra Rgnl, RNAV (GPS)

YRWY 12, Orig. Bishop, CA, Eastern Sierra Rgnl, RNAV (GPS)

Z RWY 12, Orig. On February 25, 2008 (73 FR 9935), the FAA published an Amendment in DocketNo. 30593, AmdtNo. 3256 to Part 97 ofthe Federal Aviation Regulations under section 97.33, effective April 10, 2008, which are hereby corrected tobe effective July 31, 2008: Woodward, OK,West Woodward, NDB RWY

17, Amdt 3, CANCELLED.
[FR Doc. E8-5172 Filed 3-18-08; 8:45 am]

BILLING CODE 4910-13-P

COMMERCE DEPARTMENT
Industryand Security Bureau

15 CFR Part 738 *

Commerce Control ListOverview and the Country Chart

CFR Correction

In Title 15 ofthe Code ofFederal Regulations, Parts 300 to 799, revised as ofJanuary 1,2008, in part 738, in Supplement No. 1,onpage 244, an "X" is added in the entry for Tonga under the heading CC3. [FRDoc. 08-55506 Filed3-18-08; 8:45 am]

BILUNG CODE 1505-01-D

PEACE CORPS

22 CFR Part 310

Governmentwide Debarment and Suspension (Nonprocurement)

CFR Correction

In Title 22 ofthe Code ofFederal Regulations, Parts 300 to 1799, revised as ofApril 1, 2007, on page 49, the appendix to Part 310 is removed. [FR Doc..08-55503 Filed3-18-08; 8:45 am]

BILLING CODE 1505-01-0

DEPARTMENT OF THE TREASURY

Internal Revenue Service

26 CFR Part 1

Income Taxes

CFR Correction

In Title 26 ofthe Code ofFederal Regulations, Part I (§ 1.1551 to End), revised as ofApril 1,2007, on page439, in §1.6654-2, in the undesignated paragraph following-paragraph (d)(2)(ii)(B), make the following changes:

1.In the first sentence, after the word "attributable", insert the words "to months in such partnership taxable"; and

2.At the beginning ofthe third sentence, remove the words "In addition, a partner shall include in his taxing after December" and add the words "In addition, a partner shall include inhis taxable income and, for taxable years beginning after December" intheir place. [FR Doc. 08-55505 Filed 3-18-08; 8:45 am]

BILLING CODE 1505-01-D

ENVIRONMENTAL PROTECTION
AGENCY

40 CFR Parts 52 and 81 [EPA-R09-OAR-2006-0583, FRL-8542-6]
Approval and Promulgation of Implementation Plans; Designation of Areas forAir Quality Planning Purposes; State of California; PM-10; Affirmation of Determination of Attainment forthe San Joaquin Valley Nonattainment Area
AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule.

SUMMARY: EPA is finalizing its proposal to affirm its October 30, 2006, determination that the San Joaquin Valley nonattainment area (SJV orthe Valley) inCalifornia has attained the National Ambient Air Quality Standard (NAAQS) for particulate matter with an aerodynamic diameter less than or equal to anominal 10micrometers (PM-10). EPA proposed to affirm the determination ofattainment in order to take comment on theexclusion from a 

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### 73, No. 54/Wedinesday, March '19, 2608/Rue and Regulatiohs

determination ofattainment,ofPM-10 exceedances that were caused by exceptional events. EPA i'sconcurring with the State's request to flag I exceedances which occurred in the SJV.

asbeing caused-by exceptionalevents, i.e., high winds. EPA is also concurring with the Santa Rosa Rancheria Tribe's request to flag, as due to an exceptional event, PM-10 exceedances which occurred ontribal lands located within the boundaries ofthe SJV. EPA is further finding that these exceedances at the Santa Rosa Rancheria (SRR) should be excluded from use in determining attainment because the exceedances occurred while the monitor was operating in very close proximity to construction activities and, as such, the monitor was notproperly sited during that time forpurposes ofcomparison to the NAAQS. As a result,EPA is affirming its determination that the SJV has attained thePM-10 standard based

on EPA's evaluation ofquality-assured data through 2006..

In addition, EPA did notreceive
comments on how the Agency addressed the issues raised in petitions for reconsideration and withdrawal of EPA's 2006 determination ofattainment, filed byEarthjustice onbehalf ofthe Sierra Club, Latino Issues Forum and others, and thus we are denying the petitions. DATES: Effective Date:This rule is effective on April 18, 2008. ADDRESSES: EPA has established docket number EPA-R09-OAR-2006-0583 for this action. The index to the docket is available electronically at www.regulations.govand in hard copy atEPA Region IX, 75 Hawthorne Street, San Francisco, California. While all documents inthe docket are listed in the index, some information may be publicly available only at thehard copy location (e.g., copyrighted material), and

some may notbe publicly available in either location (e.g., CBI). To inspect the hard copy materials, please schedule an appointment during normal business hours with the contact listed inthe FOR FURTHER INFORMATION CONTACT section. FOR FURTHER INFORMATION CONTACT: Doris Lo, EPA Region IX, (415) 972- 3959, lo.doris@epa.govor BobPallarino, EPA Region IX, (415) 947-4128, pallarino.bob@epa.gov.
SUPPLEMENTARY INFORMATION: Throughout this document, "we," "us" and "our" referto EPA.
Table ofContents I.Summary ofProposed Action I. Public Comments andEPA Responses

A. Earthjustice Comments 1.Overview Comments 2..Comments Specific toSeptember 22, 2006--Corcoran, Bakersfield andOildale 3.Comments Specific to October25,

2006-Corcoran and Bakersfield B.Other Comments C.ListofEPA Figures in the Docket III. FinalAction IV. Statutory and Executive Order Reviews
1. Summary ofProposed Action

On August 27, 2007, EPA proposed to affirmits determination that the SJVhas attained the 24-hour NAAQS for PM-IO. 72 FR49046.1 EPA issued this proposed rule in order to take comment on the exclusion of several PM-10 exceedances that were caused by exceptional events, and, inthe case ofthe SRR, improper siting ofthe monitor forpurposes of comparison to the NAAQS. These exceedances are summarized inTable 1 inthe proposed rule.

### Id. at49047. For

amore detailed discussion ofthe related background forthe SJV and ofthe proposal, please refer to the proposed rule.

II.Public Comments and EPA Responses

EPA received three comment letters supporting the proposal to affirm the attainment determination. These
comments were submittedby the California Cotton Ginners and Growers Association, the Tulare County Farm Bureau and the Western United Dairymen. Ingeneral, these commenters support the cases that are made for the exceptional event exceedances and discuss the many control measures and efforts that have been made to achieve -attainment. The commenters also point
to the SJV's continued efforts to achieve further air quality improvements under the PM-2.5 plan development. One
commenter provides information to show that no cotton harvesting was occurring in September 2006. Finally, the commenters question the representativeness ofthe 2000 comment letters received by EPA inresponse to

ourJuly 19, 2006, attainment determination proposal (71 FR40952) since the majority ofthe commenters appear to reside outside the SJV.

EPA received three adverse comment letters. Two were from private citizens from the state ofTennessee and one was from Earthjustice, representing Sierra Club, Latino Issues Forum,Medical Advocates for Healthy Air, the Steven and Michele Kirsch Foundation, TriValley CAREs, Concerned Residents of Lockwood Valley, Fresno Coalition Against the Misuse.ofPesticides,

I On October 17, 2006, EPA finalized its determination that the SJVattained the NAAQS for PM-10 and onOctober 30, 2006, EPA published this determination in the Federal Register. 71 FR 63642. Califoia Communities Against Toxics, FresntPMetro Ministry, Coalition for Clean Air, Center for Biological Diversity, and the Association of Irritated Residents. 2 The majority ofthe
comments discussed below are raised by Earthjustice.

EPA notes that although itreceived

numerous specific comments onthe September 22, 2006, October 25, 2006, andthe SRR exceedances, no adverse
comments are directed specifically at EPA's finding that exceedances' monitored on December 8, 2006, at Corcoran andBakersfield-Golden State Highway (Bakersfield)were caused by

an exceptional high wind event. Thus, EPA does notaddress any substantive issues regarding these exceedances inits responses to comments.

In subsection A.below we respond to the extensive cdmments raised by Earthjustice. Insubsection B. we respond to comments raised by other parties.

A. EarthjusticeComments
1. Overview Comments

Comment 1:Earthjustice explains that its comments analyze EPA's proposed affirmation rule under the new Exceptional Events Rule (EER). 72 FR 13560 (March 22, 2007). In thisregard, Earthjustice states that, "assuming EPA has the discretion to apply thenew rule," EPA's decision to do so is completely arbitrary given that the San Joaquin Valley AirPollution Control District (District or SJVAPCD) prepared its analyses under EPA's priorpolicies and did notinvoke the new regulatory requirements.

Response 1:EPA addressed the issue of the applicability of the new EER to the events at issue inthis rulemaking in its proposed affirmation rule. EPA explained that the statutory provision upon which the new rule is based, CAA section 319, as amended by section 6013 ofthe Safe Accountable Flexible Efficient-Transportation Equity Act: A Legacy for Users (SAFE-TEA-LU) of 2005, provides that the Agency's preexisting guidance documents continue to apply until the effective date ofthe rule. CAA section 319(b)(4). As mandated by section 319, EPA finalized andpublished the finalEER in March 2007. This rulebecame effective onMay 21, 2007, requiring EPA to follow the rule in making exceptional events determinations after that date.

2The proposal provided a 30 day comment period ending on September 26, 2007.EPA received

arequest for an additional 30 days to comment and granted that request extending the comment period until October 26, 2007. 72 FR 53743 (September 20, 2007).

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### Federal Register/Vol. 73, No. 54/Wednesday, March 19, 2008 /Rules and Regulations

Therefore, inmaking andpublishing its determination afterthe effective date of theEER, EPA followed its procedures and criteria in evaluating the State's exceptional events demonstrations. 72 FR at 49048.



### Although EPA followed theEER in this particular instance, andbelieves it should be followed in most cases,the Agency recognized that there might be certain instances where EPA hadnot yet made a decision on a state's already completed and submitted demonstration ofan exceptional event and these demonstrations werethus caught midstream. In those instances, EPA concluded that astate could choosefor

a limitedperiod tocomply with either theprovisions oftherule orthose ofthe Agency's existing policies and, that if asked, EPA would act underthepolicy

on agrandfathering rationale fora short timeperiod. EPA continues tobelieve thatthistransitional policy was reasonable in the absence ofan explicit statutory directive addressing that situation.Here, the State did not indicate that its submissions should be evaluated under the existing policies. Therefore, EPA applied the rule, which

was already effective, when itmade its determinations on the exceptional events inthe SJV. Comment2:Earthjustice, citing case law, states thatEPA mustprovide a rational basisto supportits conclusions regarding the exclusion ofmonitoring data showing NAAQS exceedances and that its decisions musthave a "substantial basis in facts." Earthjustice cites 40CFR 50.14(c)(3)(iii) and CAA section 319(b)(3)(B), respectively, forthe propositions that for EPA's determination here the Districtmust provide actual evidence to support its claims and thatthe occurrence of an exceptional event mustbe "demonstrated by reliable, accurate data." Earthjustice claims that even under a weightofevidence standard there must be evidence supporting the specific findings andthat reliance ona plausible story isnot enough.

Response2:EPA agrees with Earthjustice's characterization ofthe general demonstration, as stated in our summary ofits comment above, that mustbe made in order to exclude data showing NAAQS exceedances. EPA believes that ithas, both intheproposed affirmation ruleand thisfinal rule, provided arational basis supportedby reliable, accurate data for its conclusions that the September, October and December 2006 PM-10 exceedances 

### in the SJV were caused by exceptional
events. See 72 FR at 59050-49063 and



### ourresponses to comments below. Comment3: Regarding its contention concerning the lack ofreliable and
accurate data,Earthjustice cites EPA's
statements inthe proposed affirmation rule at 72 FRat 49053 that activity levels on September 22, 2006 were "constant" and that reasonable controls

were in place to control particulate matterwhile providing only general or anecdotal evidence in the form ofnonspecific District inspector observations and "discussions with representatives of agricultural and industrial operations." CitingCAA section 319(b)(3)(B), Earthjustice claims that this doesnot satisfy the statutory requirement that "exceptionality" be based on reliable,
accurate data.

Response3: Inthe section of the proposed affilnation rule cited by Earthjustice we discussed our conclusion that the State's documentation demonstrates that the exceedances atCorcoran, Bakersfield and Oildale on September 22, 2006 would not have occurred but forthe wind event onthis day. EPA based this conclusion onthe totality ofthe evidence presented by the State which included, butwas not limited to, the information on activity levels and control measures singled outby Earthjustice. For the additional factors EPA considered in.reaching its conclusion, see section V.A.2.d. in our proposed affirmation rule (72 FRat 49053) and ourresponses to comments below. Comment 4:Earthjustice claims that EPAoffers no evidence to support the construction claims regarding the SRR. It asserts that EPA cannot say what if anything was occurring on the days in question, where it was occurring, or whyit could notbe reasonably controlled. Earthjustice also maintains that EPA cannot show that construction activity at the SRR is related to the measured exceedances and,as a result, EPAcannot show the required "clear causal relationship." Further,EPA
cannot say when these events occurred and why these allegedly ongoing activities only resulted in exceedances during the same period that monitors in other areas ofthe SJVstarted monitoring exceedances. Earthjustice argues that EPA cannot make the required "but for" showing at the SRRbecause EPA cannot show that there was an event inthe first place. Earthjustice further contends that EPA did not provide adequate evidence, including written accounts, that the construction activity took place on the days the exceedances occurred. Earthjustice claims that "no one was able to produce any written account, in the form ofcontractor records, work orders, schedules, or anything elsethat 

### would confirm that construction activity did, in fact, take place on the days in question." Finally, Earthjustice states that "mere posthoc speculation and anecdotal accounts ofwhat probably happened does not establish a basis for waiving these data."

Response4: First, Earthjustice notes that EPA proposed to exclude the SRR violations ontwogrounds: (1) The monitor wasnot properly sited, and (2) the nearby construction activity was an exceptional event. Earthjustice concedes that "[bloth ofthese conclusions seem reasonable ifthe activity can be shown
to have occurred onthe days the monitor recorded violations." Earthjustice Comments (EC) at 23. 3 Earthjustice contends, however, that EPA didnot provide "any such evidence."

Contrary to Earthjustice's assertion, EPA in its proposed affirmation rule provided ademonstration that construction activity, involving the grading and paving ofparking lots,took place inclose proximity to the SRR monitor duringthe period the exceedances at the SRR monitor occurred, and that this activity caused the exceedances. EPA inits proposal set forth information derived from eyewitness accounts, meteorological data, contemporaneous tracking reports, and an account ofan EPAexpert's own visit to the site. 72 FR at49060-49063. EPA did include written documentation ofthe events atissue. This written documentation included sample tracking reports that accompanied the filters from the monitors and described the conditions at the time ofthe monitoring, and an EPA expert's report ofhis site visit and interviews of witnesses to the events. There is no requirement in theEER that documentation ofevents include specific types ofwritten documentation, such as those cited byEarthjustice.4 Nor

3Earthjustice concedes, moreover, that under the EERthe requirements for fribal governments appear tobe "much more flexible * * " and "lilt would
not takemuch to make these demonstrations." EC

at 22.

"Note that we are not specifying what will be required as a minimum level ofdocumentation in all casesbecause facts and circumstances will vary significantly based on, among other things, geography, meteorology and therelative complexity ofsource contributions to measured concentrations
in any particular location. 72 FR at 13573. A particular instance may require more or less documentation, depending on theparticular facts or circumstances. The simplest demonstrations could consist ofnewspaper accounts or satellite images to demonstrate that an eventoccurred together with daily and seasonal average ambient concentrations to demonstrate an unusually high ambient concentration level, which is clearly indicative of

an exceptional impact. Such is the case with events such as volcanic eruptions and nearby forest fires.
Continued 

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is there any requirement for specific types of documentation forEPA to demonstrate its alternative ground for excluding the data under principles established in 40 CFR part 58, appendix E, that during the period ofthe nearby construction the monitor was not properly sited forpurposes ofcollecting data for comparison to the NAAQS. 72 FR at 49060-49061.

EPA's findings were supported by information from interviews with three individuals withfirsthand knowledge of the activities that took place near the monitor, as well as by contemporaneous documentation from filter sample tracking reports. These individuals were the SRR environmental technician responsible for overseeing the operation ofthe monitor, the SRR construction superintendent, and aprivate environmental consultant working for. the Santa Rosa Rancheria EPA (SRREPA). The construction superintendent and the consultant concurred with the SRR environmental technician's recollection that grading and paving ofthe parking lots took place in September and October 2006, and the environmental technician concluded that these activities caused the exceedances on September i4and 20, 2006 and later in October, when the initial paving had to beremoved and the parking lot repaved.

EPA's July 18, 2007, Memorandum, "On-Sfte Visit to Santa Rosa Rancheria," from Bob Pallarino, EPA, to Sean Hogan, EPA (SiteVisit Memorandum), contains the following account:

The construction activity entailed grading and leveling theground, application of subbase material, and paving with asphalt.The par[kling lot was firstpaved in September andit is thisproject which [the SRR environmental technician] believed caused the exceedances on September 14 and20. * * * the first paving* * *hadto be removed and theparking lotrepaved. 5 Itis this second part of the paving project which [the environmental technician] believed caused the October exceedance. * * * [T]he SRR environmental consultant stated thathe had witnessed'these construction activities during September andOctober, 2006. * * * The construction supervisorconcurred with [the environmental technician's] recollection ofthe construction activity * * *
'SiteVisit Memorandum at 2-3. The information aboutthe timing of the construction activity, from witnesses withboth firsthand and expert

Id.More documentation would beneeded to support situations that are not as straightforward.

5The Site Memorandum stated that the first paving project "did not pass inspection and the paving had to be removed andthe parking lot repaved." The FacilityManager in his letter of December 2007 referred to the first paving ofthe parking lot as "temporary." knowledge, is confirmed by documentation from the California Air Resources Board (CARB) sample tracking reports that the SRREPA environmental technician filled out at the time the samples were obtained, and forwarded to CARB along with the monitored samples. The SRREPA technician observed the "sampling conditions" at the time the monitor was operating and noted on the sample tracking forms, which are completed with each sampling run, that there was "construction nearby." This was signified by the letter "J". Earthjustice ignores this corroborating documentation, cited by EPA in its proposal, and included in the rulemaking docket. 72 FR at49062. It is significant that these sample tracking forms were prepared before the filters from the monitors were sent to and analyzed bythe lab. Thus atthe time the technician noted that nearby construction was occurring during the monitoring, he could not have known whether ornot an exceedance was recorded that day.

EPA's proposal also showed that the meteorological data lend support to the environmental technician's account of the events ofthe days in question. The winds onthe three days that exceeded the NAAQS were predominantly from the northwest, north and northeast. This would indicate that any dust-producing activity north and northeast ofthe monitor would result inhigh concentrations ofgeologic dust being blown towards the monitor. Site Visit Memorandum at 2.

Further corroboration ofthe impact of the construction onthe monitor came from EPA's assessment ofthe proximity of the monitoring site to the nearby ° parking lots. EPA's onsite inspection ascertained that one ofthe parking lots

was within 25 feet ofthe monitor, and the other was within 100 feet. 72 FR at 49062.

Reinforcing EPA's conclusion that construction activities near the monitor caused the exceedances was the fact, pointed to in the proposed rule, that after completion ofthe paving projects, average PM-10 concentrations dropped by more than 50 percent. Id.

Since the proposal, EPA has.obtained further documentation that the exceedances occurred during the period of construction activity in close ,proximity to the monitor. The Facility Director ofthe Tribe's hotel and casino has providedEPA witha letter stating that asphalt work on the parking lots closeto the monitoring station was completed between August 15 and November 4, 2006. Enclosed with the letter was a billing statement from the Tribe's general contractor for the period up to August'15, 2006. The statement shows that work on the parking lots closeto the monitor remained to be completed after August 15. The letter from the Facility Director states that at the time ofthe monitored exceedances, there were earthmoving activities nearby and paving activities near the site ofthe monitor "in a large area for parking for Trib.l Administrators and forour customers."

Thus, in addition to ihe documentation available at the time of the proposal, EPA has provided a letter from the Tribe and a billing statement from the general contractor that support the conclusion that paving wqrk was occurring at the time ofthe exceedances.

Earthjustice argues that because exceedances did not occur on other days when construction activities were occurring, this indicates that construction didnot cause the exceedances in September and October 2006. Butthis argument is misleading. Generally, varying degrees, types and locations ofthe construction activity, and changing meteorological conditions lead to varying impacts onthe monitor. The fact that construction activities did
not cause exceedances on some days does not mean that they were not responsible for the exceedances that occurred on other days. In addition, although Earthjustice claims that two days ofviolations at the SRR "correlate wellwith violations seen in other parts ofthe Valley," no other violations were monitored in the Valley on September 14 and 20 and October 26, 2006.

Earthjustice also claims that EPA "still needsto make the other required showings" for exceptional events, "including that these sources were reasonably controlled." EC at 22. EPA made these showings in its proposal, and Earthjustice did notraise any specific grounds to challenge them. See 72 FR at 49061-49062. In its proposal EPA, after discussing whether the construction activity's impact onthe monitor was reasonably controllable, concluded that "under the particular set ofcircumstances presented here, forthe purposes ofevaluating the 'reasonably controllable' criterion of the EER, we deem this criterion to have been satisfied." EPA found that even if control measures had been employed,

we cannot be certain they would have prevented exceedances at the monitor, and that EPA's monitor siting rules provide that the monitor should not be operated at such a time and place for the purposes for determining attainment. 72 FR at 49062. We note that the criteria under the EER do not apply forthe

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purposes of our alternative ground, that the monitor was not properly sited. See 72 FRat 49060-49061. Thus EPA is finalizing its determination that there

are two independent bases for determining that the exceedances recorded atthe SRR in September and October, 2006 should be excluded from consideration in determining whether the SJVhas attained the PM-10 standard: (1) The monitorwas not properly sited, under the principles established in part 58, appendix E, and (2) the construction activity constitutes

an exceptional event under EPA's EER.

Comment5:Earthjustice states that EPA cannot point to any statutory or regulatory authority that allows it to treat wind-entrained particulate matter pollution from land that has been disturbed by human activities, i.e., agriculture or construction as "natural." Earthjustice observes that, while EPA cites preamble language in the EER regarding high winds, this language was
never codified even though the final rule does contain provisions relating to the treatment ofother anthropogenic

sources such as fireworks and prescribed fire. Earthjustice suggests that even though a natural event is defined in 40 CFR 50.1(k)as "an event in which human activity plays little or
no direct causal role," EPA attempts to define an event in which windentrained dust from agricultural and industrial operations as natural. Earthjustice cites legislative history of the 1990 Clean Air ActAmendments (CAAA) to support its contention that this result defies logic and flies inthe face of Congressional intent as evidenced by Congress's refusal to

excuse duststorms from Mono and Owens lakebeds because they were human-caused. Earthjustice claims that ifthe measures in place are not enough to prevent exceedances due to windentrained dust, then Congress intended that additional controls berequired.

Response5:Section 319, as amended, defines an exceptional event as an event that affects air quality, is notreasonably preventable orcontrollable, is anatural
event oris an event caused by human activity that is unlikely to recur ata particular location. Under this definition, foran event to qualify as an exceptional event, bothnatural events and events caused byhuman activity must beevents that are notreasonably preventable orcontrollable. Therefore, Earthjustice's conclusion that designating an event "natural" would "allow air agencies to avoid controls" is

erroneous. An agency flagging data as due to an exceptional event, including

a high wind event, will be required to show that the event was not reasonably preventable or controllable. In the preamble to the final rule, EPA explained how it would evaluate whether an agency had been able to successfully demonstrate that an event metthis criteriaby taking into account the controls inplace, the wind speed, and other factors. 72 FR at 13565- 13566, 13576-13577. As explained elsewhere inour responses to comments below, inthis particular instance the District's Regulation VIII (general fugitive dustrules) and Rule 4550 which limits fugitive dust emissions specifically from agricultural operations through Conservation Management Practices (CMPs) were inplace. In addition,the District has adopted and is implementing EPA-approved best available control measures (BACM)for all significant sources ofPM-10in the SW.

Earthjustice incorrectly states that if

an event is classified as a natural event,

a state would be ableto "avoid controls." In the proposed EER, EPA explained that it was proposing to treat high wind events that result in exceedances orviolations as anatural
event provided a clear causal relationship between the wind event and the measured exceedance was established and contributing anthropogenic activities were "reasonably well-controlled." 6In the final rule, after considering the
comments on high wind events including on the terminology and the definition, EPA adopted an approach that considers high winds anatural
event ifcontributing anthropogenic activities are controlled through "reasonable and appropriate measures." 72 FR at 13566. To qualify as a natural
event (asubset ofexceptional events under the rule) a state must demonstrate, among others, that dust from contributing anthropogenic

sources was "reasonably well-controlled
at the time the event occurred." 72 FR at 13576. The EER, therefore, has already defined what constitutes ahigh wind event through appropriate notice and commentrulemaking. Thus, the question ofwhether a high wind that

causes exceedances or violations due to entrainment ofdust from anthropogenic

sources can be defined as anatural
event is not an issuethat is open for
comment in thisrulemaking. Inthis

6EPA madethis statement in the context ofPM2.5 because at thetime, the Agency was considering adopting thePM1O-2.5 standard and noted that states wouldbe expected to have appropriate controls forcontributing anthropogenic emissions under the definition oftheproposed PM10-2.5 indicator. The Agency, eventually, did not finalize thePM10-2.5 indicator andinstead retained the 24- hourPM-IO standard. case, the Agency has only asked for
comments on whether the particular high wind event metthe criteria and procedures established under the rule, e.g., establishing a causal connection, reasonable controls on anthropogenic
sources, wind speed and direction, etc., and not on whether these criteria are appropriate.

Earthjustice cites to the legislative history ofthe 1990 CAAA, for the discussion on Owens and Mono lakebeds where Congress indicated that diversion ofwater from these lakes created an anthropogenic source ofdust. Fromthis Earthjustice contrives an overly-broad conclusion that any "dust from lands disturbed by human activity" mustbe treated as an anthropogenic rather than anatural
event. Under this proposition gale-force winds, for example of 100 mph, in an urban area could not betreated as a natural event because human activity would be acontributing factor.

. As amatter ofrecord, the legislative history also demonstrates that EPA concurred with Congress that the diversion ofwater created an anthropogenic source of dustin the Owens and Mono lakebeds. Pub. L. 101- 549, CAA Amendments of 1990 House Report No. 101-290(1), May 17, 1990. EPA, however, does not interpret the statutory language ina manner that considers any anthropogenic contribution to anatural event as transforming it into an anthropogenic
event. Inthe Mono and Owens lakebed situation, EPA believed that the anthropogenic contribution was such that dust blown from those areas should betreated as anthropogenic rather than natural events. In other high winds instances, however, wherethere were anthropogenic contributions with adequate controls in place, EPA treated the high wind events as natural events.

Inits Natural Events Policy, EPA stated that it would treat a high wind event as anatural event even ifthe dust originated from anthropogenic sources, provided best available control

measures were in place. Memorandum from Mary D. Nichols, Assistant Administrator for Air and Radiation to Regional Air Directors, "Areas Affected by PM-10 Natural Events," May 30, 1996 (NEP) at 7.Congress was cognizant ofEPA's existingpolicies on natural and anthropogenic events and howEPA interpreted and implemented these policies. In amending section 319, Congress specifically required EPA to continue to apply its NEP duringthe exceptional events rulemaking process,
an unlikely action ifit disagreed with EPA's interpretation ofnatural events. Section 319 (b)(4)(B). Under the NEP, 14691

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EPA treated high wind events as natural
events andreasonably well-controlled if contributing anthropogenic sources had BACM in place. NEP at 7. During the exceptional events rulemaking, EPA sought comment on a number of options formitigation requirements, including whether to continue to require BACM for such events. After considering all
comments onthe proposed options, EPA explained in the preamble to the final rule that it would continue to require that anthropogenic sources contributing to high wind events be well-controlled through reasonable and appropriate measures. 72 FR at 13566. EPA, therefore, believes its interpretation ofahigh wind event as set forth in the preamble to the EER conforms to congressional intent and the requirements of section 319.

Also, inresponse to Earthjustice's assertion that EPA cites no statutory or regulatory authority that permits usto treat high wind as a natural event, as discussed above, Congress was aware of EPA's interpretation ofnatural events as evidenced by the statutory reference to the NEP (Section 319(b)(4)(B)) and it is self-evident that volcanic, seismic, high wind, and other similar events are natural events under section 50.1(k) of the EER. Therefore, EPA did not find it necessary to specifically list these
events as exceptional events inthe final rule. When asking forcomments in the proposed rule, we noted that some of these exceptional events (including volcanic, seismic and high wind events) have "unusual characteristics" and needed a fuller discussion inthe preamble regarding how states may meet the requirements established inthe EER. 71 FR at 12605.EPA believed that this explanation in the preamble was sufficient to assist states in developing their demonstration requirements and didnot make.it necessary to specifically list these events as exceptional events in the finalrule. Comment6:Earthjustice claims that

even ifEPA had codified the preamble language allowing dust from lands disturbed byhuman activity to be excused, EPA offers no evidence to show whether the sources that allegedly

were responsible for the dust were reasonably well controlled atthe time the event occurred. Earthjustice states that EPA must show that the sources

were actually controlled, notjust that they were subject to controls. Earthjustice believes that reasonable controls would have prevented dust from being entrained bythe stated wind speeds and that ifthe winds at issue picked up the large amounts of particulate concentrations claimed, then by definition, these sources were not reasonably controlled. Withrespect to September 22, 2006, Earthjustice asserts that the fact that the District claims that the dust came from anthropogenic

sources being scoured by winds under 25 mph for a short period oftime means that reasonable measures could nothave been in place. Therefore, Earthjustice claims that either the dust was not caused by wind or the sources did not have reasonable controls that would have prevented the event. With respect to October 25, 2006, Earthjustice asserts that none ofthe 90 inspections conducted bythe District was inor around the Lemoore/Corcoran area where the dust allegedly originated.

Response 6:With respect to reasonable controls, in the preamble to the EER we explained that "ambient particulate.matter concentrations due to dustbeing raisedby unusually high winds willbe treated as due to uncontrollable natural events where * * * the dust originated from

- anthropogenic sources within the State, that are determined to have been reasonably well-controlled at the time that the event occurred, orfrom anthropogenic sources outside the State.* * * In cases where anthropogenic sources are determined
to have contributed to exceedances or violations due to high wind events at air quality monitoring sites, per our decision inthis rulemaking concerning the action that States musttake to mitigate the impact ofexceptional
events on public health * * * States
musttake reasonable and appropriate.

measures to mitigate the impact associated with the event on public health." 72 FR at 13576-13577.

As we observed in ourproposed affirmation rule, Regulation VIII and District Rule 4550 were in place atthe time ofthe events in question. Furthermore, we noted that EPA has approved the District's BACM demonstration for all significant sources of PM-10 in the SJV as meeting CAA section 189(b)(1)(B). See 72 at 49053 and 49057. Moreover, the District conducted'numerous inspections of PM-10 sources in the SJV on September 22 and October 25, 2006. Thus controls beyond those deemed "reasonable"

werebeing implemented and enforced inthe SJV onthose dates.

Contrary to Earthjustice's apparent belief,there is nothing in either the preamble to the EER or the rule itself that requires EPA to show that all

sources were "actually controlled" at the time ofthe events. Moreover, there

are thousands offugitive dust sources in the SJV,7 an area ofnearly 25,000 square miles which constitutes approximately 16percent ofthe geographic area of California. 2003 PM1O Plan for the SJV at 2-1. As aresult it would be a practical impossibility forthe District, a publicly-funded agency, to determine whether every source was in compliance with its regulations on any given day, the standard Earthjustice evidently espouses. The fact that the District conducted 90 inspections on October 25, 2006 and none was in Lemoore or Corcoran simply illustrates the magnitude ofthe task Earthjustice suggests should be mandatory for the exclusion ofdata from an exceptional
event.

Finally, Earthjustice presents no support for its contention that controls

on anthropogenic sources beyond those already inplace would have prevented dust from being entrained by the stated wind speeds. Earthjustice simply asserts (see comment 7) without evidence that there are numerous measures available that could have prevented orreduced entrainment ofparticulate matter.As we have shown, reasonable controls were in place onthe days in question and the* exceedances occurred notwithstanding those controls. See also our response to comment 7below.

Comment 7:Earthjustice further asserts that there are numerous
measures available that could have reduced or prevented the entrainment of particulate matter by winds above the entrainment threshold of 18 mph, many ofwhich are included but notrequired by the District's agricultural CMP rule and Regulation VIII. Earthjustice provides anumber of examples that it claims are effective in reducing or eliminating erosion and transport ofsoil particles during high wind events. Earthjustice concludes that even assuming 100 percent compliance with the agricultural CMP rule and Regulation VIII, "not one ofthese

measures is required to-be in place by these so-called BACM level controls." Thus Earthjustice alleges that sources could be 100 percent in compliance with District rules and still notbe doing anything to prevent wind-generated entrainment ofparticulates.

Response 7: As we stated inthe preamble to the EER, where wind speed results in particulate matter exceedances, a clear causal relationship
mustbe demonstrated between the exceedances measured at the air quality monitoring site and the high wind event

7Forexample, theDistrict has approved over 6,000 applications under Rule 4550. "Conservation Management Practices Program Report for 2005," January 19, 2006, SJVAPCD at 5.

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in question in order fordata affectedby these events tobe excluded underthe weight ofevidence approach. 72 FR at 13566, footnote 11. We further stated that "EPA will consider inthe weight of evidence analysis winds that produce emissions contributed toby anthropogenic activities that havebeen controlled to the extent possible through

use ofallreasonably available reasonable and appropriate measures." Id.

EPA approved Regulation VIII-as BACM onFebruary 17, 2006 (71 FR 8461) and Rule 4550 asBACM on February 14, 2006 (71 FR 7683). The control measures inthese rules are designed toreduce fugitive dust emissions. Anumber ofthe measures that sources can choose incompliance with therules are also specifically designed toreduce or prevent entrainment ofparticulate matter during wind events. See, forexample, in the "List ofConservation Management

. Practices," May 20, 2004, for Rule4550 in the "Cropland-Other" category the following measures: alternate till, bulk materials control, cover crops, permanent crops, surface roughening, wind barrier.

EPA determines what controls constitute "all reasonably available reasonable and appropriate measures"

ona caseby casebasis. With regard to the SJV, EPA has agreed withthe District's finding that "* * *unlike other arid western PM-10 serious nonattainment areas, the SJV doesnot have a regular and repeated windblown dust problem." 71 FR at 7686. In addition, inresponding to a comment
onits proposed approval ofthe 2003 PM-10 serious area plan forthe SJV, EPA observed that "[oinly five PM-10 exceedance days spanning a 13-year period were identified as associated with strongwinds." 69 FR 30006, 30033 (May 26, 2004). Under these circumstances, EPAbelieves thatitwas not necessary for the District'srules to mandate the selection ofwindblown dust measures and that the BACM controlsbeing implemented inthe SJV constitute "all reasonably available reasonable andappropriate measures."

Comment8:Earthjustice argues that the events at issuecannot be claimed as exceptionalbecause the District did not make its demonstration according tothe procedures outlined in the EER. Specifically, Earthjustice states that while EPA relies on demonstrations prepared bythe District in April and May 2007, the only opportunity for public comment provided bythe District was onthe February 2007 version ofthe analysis. Moreover, Earthjustice states, only 15 calendar days were provided for comment on the February version and the preamble to EPA's EER provides for a 30-day comment period. Earthjustice states that
to the extent that EPA believes preamble
statements to be enforceable, the event cannot be deemed exceptional because the District did notmeet the procedural requirements in the EER. Earthjustice also asserts that since the District's rationalefor flagging the September 22, 2006 exceedances changed so markedly

as to make comments onthe first draft irrelevant, the documentation should have been put out for a second round of public comment. Earthjustice further states that insofar as the EER applies to EPA's affirmation action, the District also failed to meet itsprocedural requirements that documentation justifying exclusion must be submitted

nolater than 12 months before a regulatory decision is made. Here, Earthjustice asserts, EPA based its regulatory decision to findthe SJV in attainment on the exclusion ofdata before any demonstration supporting the exclusion was drafted by the State.

Response 8:The public did have an adequate opportunity forreview and
comment on the State's documentation ofthe exceptional events. Earthjustice complains that the State did not provide

a 30-day comment period onthe documentation ofexceptional events, and further contends that there was no opportunity to review and comment after the District revised this. documentation. EPA's EERprovides that a statethat has flagged data asbeing due to an exceptional event and that is requesting exclusion ofthe data shall "after notice and opportunity forpublic comment, submit a demonstration" to EPA, along with any public comments itreceived. 40 CFR 50.14(c)(3)(i).

With respect to Earthjustice's first contention regarding the 30-day
commentperiod, theEER contains no such requirement. The language cited by Earthjustice that purports to characteriz6 30 days as a requirement is found in the preamble only, 72 FR 13574, and does not reflect the language ofthe rule. Thus, while indicative ofa period that EPA would deem reasonable, the preamble language regarding a 30-day comment period does not serve to make such aperiod mandatory. Nor doesit mean that a shorter commentperiod shouldbe deemed unreasonable. Earthjustice concedes that in February 2007 the District provided atwo week comment period forits initial documentation of the September, October and December 2006 exceedances. TheDistrict received

no comments or requests for extension ofthe comment period.8 On March 21, 2007, Earthjustice filed with EPA a petition to withdraw EPA's October 2006 attainment determination, which cited to and discussed theDistrict's initial documentation. This petition, however, was directed to EPA and not to the District orthe State. Earthjustice, having failed to request an extension of the comment period and to address comments to the District and the State, cannot nowbe heard to complain about * the length ofthe initial comment period.

Subsequently, the District posted on the "Public Notices" section ofits Web site revised versions ofthe documentation for exceedances on these three days atissue, and thus the revised documentation was also available for public review and comment. These revised versions modified and clarified the technical analysis ofthe-high wind events. For the September 22 event, the District.posted on its Web site a revised set ofdocumentation, dated April 20, and CARB subsequently submitted it to EPA. The District submitted an Addendum to CARB on May 23, 2007, which it again posted on its Web site, and CARB later submitted it to EPA. 72 FR at 49050. For the October 25 event, theDistrict posted on its Web site a revised set ofdocumentation, dated April 23, and CARB again subsequently submitted it to EPA. 72 FR at 49054. For the December 8, 2006 event, which Earthjustice does not contest is an exceptional event, the District revised its documentation and submitted it to CARB on May 23, 2007, and posted it

on its Web site.At CARB's request the District made further revisions which it submitted to CARB on June 6, 2007, and posted on its Web site. 72 FR at 49057. The State later submitted it to EPA. Id.

Thus each set ofrevised documentation was available to the public inthe "Public Notices" section of the District's Web site for months prior to EPA's August 15, 2007 issuance ofits proposed rule, and EPA has found no indication that comments were submitted or inquiries received about the revised documentation. EPA therefore believes thatthere was adequate opportunity for the public to comment on the revised demonstrations madeby the District and CARB. The fact remains that no comments were submitted to the District or CARB on the original versions ofthe documentation,

nor does it appear that there were any requests for an extension ofthe comment period that closed on March 5,

6Contrary to Earthjustice'scontention (EC at3, footnote 3), EPAin itsproposal didnothing to "hide" the date that thedocumentation became available. EPA simply statedthat the documentation became available in February. 

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2007. Similarly, EPA knows ofno comments orrequests regarding the
comment period that were submitted on the subsequent versions ofthe documentation thatwere posted onthe District's Web site.

Earthjustice further contends thatEPA has failed to meet the requirement that

a demonstration be submitted to EPA no later than 12 months "prior to the date"

a regulatory decision "must" be made byEPA. EER, section 50.14(c)(3)(i). We
note initially that this section ofthe EER is designed for EPA's benefit, to furnish adequate time to review documentation, and it is thus forEPA to determine whether we require the full time allotted by the rule.

Furthermore, in the preamble we "recognize that special circumstances could dictate more expedited data delivery, flagging, and minimal demonstrations * * *." 72 FR at 13571, In this case, where EPA is actingto affirm a prior attainment determination that recognized the need for additional evaluation ofpreliminary data,EPA finds there is value inproceeding expeditiously to obtain and review the State's documentation ofthose data and surrounding exceptional events. Moreover, this action toaffirm EPA's attainment determination is not a regulatory decision that "must" be made by a certain date, and therefore the 12- month requirement is not applicable. Finally we note that the bulk ofthe revised documentation forthe September and October 2006 exceedances at issue here was submitted
to EPA inApril and May 2007, well in advance ofEPA's final regulatory decision in thisrulemaking. Thus EPA finds that, for all the reasons set forth above, the timing ofsubmission ofthe documentation here was adequate for purposes ofsection 50.14(c)(3)(i) ofthe EER.

Earthjustice also complains that in issuing the October 2006 determination ofattainment, EPA made the determination to finally concur in the flagging of exceptional events prior to receiving the State's documentation. The procedural validity ofthe October 2006 determination, and whether it provided adequate notice and cohnment, is notat issue in today's rulemaking. Thus Earthjustice's contentions with regard to notice and comment issues arising from the October 2006 rulemaking are misplacedhere.

Moreover, Earthjustice's contentions

are belied by the facts. EPA's October 2006 determination of attainmentmade clear that the data showing exceedances

on September 22, 2006 were preliminary. EPA stated that once quality-assured data were available, EPA would review those data and CARB's request with respect to them, evaluate whether the data qualified.for exclusion as caused by exceptional events, and determine whether the determination should be withdrawn.9
See discussion in EPA's proposed " affirmation rule, 72 FRat 49064. See also 71 FR 63642.

In today's rulemaking EPA has fulfilled its promise by providing ample opportunity for comment on the State's documentation and EPA's evaluation of exceedances under the EER prior to issuing afinal concurrence. As EPA noted in its proposed affirmation rule,

our purpose here is not totake comment

on the issues raised bythe 2006 attainment determination, except to the
extent that they affect EPA's ability to determine that the SJVcontinued to attain the PM-10 standard through 2006. 72 FR at 49047. The October 2006 rulemaking, whichis not at issue in this
current action, did notpurport to be a final concurrence on the State's exceptional events documentation for the September 22, exceedances. Today's rulemaking addresses quality-assured data for September, October and December 2006, for which the State has provided exceptional events documentation. Comment9:Earthjustice states that EPA argues that atthe time ofthe attainment finding the Agency merely deferred its determination ofthe impact of the preliminary data untilthey could be quality assured and the State had an opportunity to show that.the exceedance was caused by an exceptional event. Earthjustice claims thatthe data at issue hadin fact been processed by the CARB laboratory and thus already quality assured by the State when EPA was notified ofthe September 22, 2006 exceedances. In this respect, Earthjustice believes that EPA mischaracterized CARB's October 17, 2006 letter to EPA to mean that the data from the filter analyses were preliminary. Thus, Earthjustice concludes thatEPA's decision notto consider the September 22 exceedances in its October 17, 2006 attainment finding is a violation oflaw and an abuse ofdiscretion. Earthjustice also
states that this violation ofthe Administrative Procedure Act (APA)
cannot be cured with this rulemaking's post-hoc rationalization. Earthjustice interprets 40 CFR 51.14(c)(2)(ii) to mean that an exceedance mustbe considered

9 As EPAnoted in its proposed affirmation rule, EPA's October, 2006 final determination did not ignore the exceedances that occurred in October 2006 since these occurred eight days afterEPA promulgated its final determination ofattainment. 72 FR at 49064. an exceedance unless and until EPA gives -finalconcurrence following a thorough, convincing, publicly reviewed demonstration that the data

can be ignored.

Response9:As noted in the response to comment 8 above, the adequacy and validity ofthe October 2006 rulemaking is notat-issue in thisproceeding. Whether the APAwas violated inthat rulemaking is not at issue here. In this
current rulemaking, EPA thoroughly reviewed and proposed to concur with the documentation submittedby the State, andprovided full opportunity for public review and commentbefore finalizing its concurrence with the flags, andbefore excluding the data from a final determination ofattainment. The purpose ofthis rulemaking is to assess the quality-assured data and documentation ofexceptional events claims inthe context ofnotice and comment rulemaking. Thus, even if, for the sake of argument, we accept Earthjustice's contentions that there

were procedural deficiencies inthe October 2006 rulemaking, EPA would have cured any such deficiencies with the procedures it has followed in this rulemaking.

In any event, Earthjustice is incorrect in its assertions that,at the time ofthe October 2006 rulemaking, data for September 22, 2006 were not preliminary and hadbeen quality assured. The data forthe September 22 exceedances were plainly preliminary. *An EPA staff employee e-mailed a CARB branch chiefan informal request to "find out if there was any preliminary data available from the ARB lab." E-mail from Bob Pallarino, EPA, to Karen Magliano, Chief, Air Quality Data Branch, Planning and Technical Support Division, CARB, October 12, 2006. On October 13, 2006 she forwarded to EPA an informal e-mail originating from a CARB staffer. The email included data from filter analyses ofseveral monitors, which set forth numerical values representing monitored data.That e-mail stated clearly: "Ofcourse, all the data is preliminary." E-mail from Scott Randall, Inorganic Laboratory Section, Northern Laboratory Branch, CARB, to CliffPopejoy, Inorganic Laboratory Section, Northern Laboratory Branch, CARB, October 13, 2006 (forwarded to Bob Pallarino by Karen Magliano). Thus, CARB represented and EPA reasonably believed that the data showing monitored exceedances were "preliminary" and not quality assured. Indeed, EPA believed that the normal data validation and verification processes had notbeenundertaken, and that, in fact, the data had notbeen

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submitted to EPA's Air Quality System (AQS) database 10or certified by CARB. The message that the CARB staffer sent
was in responseto an informal request fromEPA staff, and inthat context EPA did notconsider it an official CARB submission of data.The informal and preliminary nature ofthe information is further indicated bythe factthat the numerical values for PM-10reported in the e-mail were not accompanied by scientific units, which would be essential documentation in any official submission ofquality-assured data, and could only be inferred by EPAbased on usual practice.

EPA didnot therefore, as Earthjustice contends, "mischaracterize" the data from the filter analyses, when it described the data as "preliminary." EC at 11, footnote 9. CARB itself characterized the data as preliminary when it forwarded them to EPA.

In any event, as noted above, what is at issue in this rulemaking is EPA's

concurrence on the exceptional events documentation forquality-assured data subsequent to EPA's October 2006 determination, and notthe procedural validity ofthat prior determination. Itis clear in thisrulemaking that EPA is determining to finally concur onthe State's flagging ofthe data only after EPA has conducted notice and comment rulemaking on documentation thatthe State has submitted to support those flags.

Comment 10:Forthe wind events, Earthjustice maintains that the data offered by the District and relied upon by EPA does notdemonstrate a "clear causal relationship" because exceedances were being measured before the events occurred.

Response 10:EPA disagrees with Earthjustice's conclusion forthe reasons discussed below. Initially it is important to understand that the 24-hour PM-10 NAAQS, 150 gig/m3, is a 24-hour averageconcentration. This means that individual hourly concentrations at any given monitoring location may exceed 150 gg/m 3

,butuntil all 24 hours ofa day are sampled acomplete daily reading cannot be calculated. Therefore it-is incorrect to characterize the data, as Earthjustice does, as showing that NAAQS exceedances were measured before the wind events.

To support its contention, Earthjustice states that fugitive dust sources in the Lemoore area on September 22 and October 25, 2006 could nothave caused the Corcoran NAAQS exceedances since the first hourly PM-10 concentrations exceeding 150gg/m 3 at Corcoran occurred either an hour before orat the 'same time as the Lemoore meteorological station recorded wind speeds exceeding the District's threshold wind speed. From these facts, Earthjustice concludes that since the monitor was already recording an hourly concentration above the NAAQS before the dust-laden winds from Lemoore11 arrived on September 22 and October 25, the monitor could nothave been impacted by them.

In evaluating this conclusion it is instructive to look at any number of days where the level ofan hourly PM10 concentration at Corcoran exceeded the level ofthe 24-hour NAAQS, yetthe 24-hour average concentration for the day didnot exceed the NAAQS. October 26 and 27, 2006, March 26 and 27, 2007, April 17, 2007, May 2 and 21, 2007, and June 5, 2007, all experienced one or
more hours exceeding the level ofthe NAAQS yet theNAAQS forthe day was not exceeded. See Table I below. The most extreme example is April 17, 2007,

on which four continuous hourly concentrations greater than 150 gg/m 3

were recorded from 4:00 p.m. Pacific Standard Time (PST)through 7p.m. PST (181, 466, 460, 236 gg/m 3

, respectively), yet the overall 24-hour average concentration for that day was only 91 gg/m 3

. TABLE 1.-NON-EXCEEDANCE DAYS WITH ONE OR MORE HOURLY PM-10 CONCENTRATIONS ABOVE 150 gG/M3 AS MEASURED AT CORCORAN

Oct 26 Oct 27 Mar 26 Mar 27 Apr 17 May 2 May 21 Jun 5 Hour* 2006 2006 2007 2007 2007 2007 2007 2007 (gg/m 3) (gg/m3) (4g/m3 ) (ig/m3) (gg/m3) (gg/m 3) (gg/m 3) (gg/m3)

0

.................. 157 79 8 0 27 18 17 21 1

....................................................................... 143 135 11 0 26 14 16 15 2

....................................................................... 146 126 8 1 30 13 15 12 3

....................................................................... 147 89 11 3 31 11. 13 13 4

....................................................................... 161 69 9 3 29 12 15 24 5

....................................................................... 175 91 1.0 3 63 26 16 24 6

....................................................................... 194 221 22 5 73 23 25 22 7

....................................................................... 232 184 19 7 34 25 28 19 8

....................... 115 158 16 0 34 20 35 14 9

....................................................................... 66 149 12 8 33 13 42 18 10

..................................................................... 53 107 2 1 22 16 59 23 11

..................................................................... 92 117 6 18 21 16 66 35 12

..................................................................... 128 86 8 122 15 20 72 61 13

..................................................................... 128 70 17 162 26 22 74 87 14

.................................................................... 133 91 7 152 54 25 85 77 15

................................................................... 115 69 7 190 138 28 84 254 16

..................................................................... 126 87 18 54 181 151 94 169 17

..................................................................... 152 116 19 86 466 239 195 145 18

................... :

................................................. 151 140 128 47 460 61 180 173 19

..................................................................... 145 116 407 8 236 • 27 127 235 20

..................................................................... 161 126 48 17 136 13 10A Rr

"OData from air monitors operated by state and local agencies in compliance with EPA monitoring requirements must be submitted to AQS. Heads of monitoring agencies annually certify that these data

are accurate to the best of theirknowledge. See 71 FR at40953.

11Throughout this final rule when we refer to Lemoore, Corcoran and Bakersfield, we mean the Lemoore area, the Corcoran area, and the Bakersfield area. When analyzing data, the State, District and EPAuse information collected from specific points where the monitors are located, whether meteorological monitors or PM-10 monitors. Since it is not possible, due to finite
resources, to monitor pollutant or meteorological parameters in every location, monitoring locations

are chosen tobe representative oflarger areas. The size ofthe arearepresented bya monitor is dependent on a number offactors, including, but
not limited to, theparameter being measured (e.g., wind speed, PM-10 concentration), the overall terrain (e.g., urban, rural, valley, etc.) andany localized characteristics that may influence the parameter being measured (e.g., obstructions such

as buildings ortrees). 

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TABLE 1.-NON-EXiEEDANCE"DAYS WITH ONE OR MORE-HOURLY PM'10 CONCENiATIONS •ABOVE 150 g/G/M 3

- As 

### MEASURED AT CORb ORAN-Continued

Oct 26 Oct 27 Mar 26 Mar 27 Apr 17 May 2 May 21 Jun 5 Hour* 2006 2006 2007 2007 2007 2007 2007 2007 (jig/m3 ) (jig/m3) (jig/m 3 ) (gg/m3) (gg/m3) (jig/m 3 ) (jig/m 3 ) (jig/m 3)

21

...................................................................... 147 118 16 15 34 14 66 34 22

............................. . ..... 124 141 4 9 14 29 61 27 23

.................................................................... 130 105 0 10 7 16 66 49
Daily Average

................................................... 137 116 34 38 91 36 65 67
Source: EPAAir Quality System Database. *Hours are inPST. AllState and local ambient air pollutant monitoring equipment inCalifornia operates on PST all year and is never adjusted for Daylight Savings Time. For example, hour 12 inthe table is 1p.m. Pacific Daylight Time (PDT).

Thus, ascan be seen from Table 1 and the discussion above, Earthjustice is incorrect when itconcludes that dustladen winds from Lemoore could not have affected the Corcoran monitor on September 22 and October 25, 2006 because concentrations above the level ofthe NAAQS were recorded at the monitor before the winds arrived By failing to account for all 24 hours ofthe day, Earthjustice has misinterpreted how EPA determines compliance with the 24-hour PM-10 NAAQS.

Earthjustice further states that fugitive dust sources inthe Lemoore area on September 22 and October 25, 2006 could not have caused the Corcoran NAAQS exceedances since the first hourly PM-10 concentrations exceeding the level ofthe NAAQS at Corcoran occurred either an hourbefore or atthe

same time as the Lemoore meteorological stationrecorded wind speeds exceeding the 18 mph threshold speed. 12 Earthjustice notes that on September .22the 6:00 a.m. hourly PM10 concentration at Corcoran exceeded the.level ofthe NAAQS and wind speeds recorded in Lemoore did not exceed the threshold wind speed until 7 a.m. On October 25 the Corcoran hourly PM-10 concentration first exceeded the levelof the NAAQS at 6
a.m., the same time the Lemoore meteorological station recorded winds inexcess of the threshold speed. 13 However, as set forthbelow, the data show that on September 22the winds at Lemoore began exceeding the threshold speed at 6 a.m. PST, and likely began affecting the concentrations atthe Corcoran monitor by the time concentrations were recorded at 7 a.m. PST.14 OnOctober 25, the winds recorded atLemoore exceeded the threshold speed at*5 a.m. PST and'likely affected the concentrations recorded at' the Corcoran monitorbeginning at 6

a.m. PST. Thus onboth days there wasatmost a period of one ortwohours where the concentrations at the monitor that exceeded the standard mightnot have been attributable to the winds from Lemoore.

Nevertheless, based upon meteorological data, EPA believes that the high concentrations measured beginning at 7 a.m. PST on September 22 and 6 a.m. on October 25 and continuing throughout the day were due
to transport ofdust by high winds in the Lemoore area, and thus resulted in the exceedance of the 24-hour NAAQS. In reaching this conclusion, EPA evaluated the available hourly concentration data from the Corcoran monitoring site 15 from October 1, 2006 through June 30, 2007 to determine how often the Corcoran site recorded high hourly concentrations inthe morning. While high morning concentrations were relatively rare in the data-we evaluated, whenthey do occur they do notalways result in a 24-hour average concentration that exceeds the NAAQS. Table 2 below compares days with high morning concentrations, October 26 and 27, 2006, that did not exceed the 24- hourNAAQS with September 22 and October 25, 2006, days with high morning concentrations that ultimately did exceed the 24-hour NAAQS.

TABLE 2.-CORCORAN HOURLY CONCENTRATIONS ON SEPTEMBER 22, OCTOBER 25, OCTOBER 26 AND OCTOBER 27, 

### 2006

September 22, October 25, October 26, October 27, Hour (standard time) 2006 2006 2006 2006 (conc. ig/rn3) (conc. jg/m 3) (conc. jg/m 3) (conc. jg/m 3)

0

....................................................................................................................... 1

....................................................................................................................... 2

....................................................................................................................... 3

.................................................................................................................... 4

................................................... 5

....................................................................................... :
.............................. 157 143 146 147 161 175

12The State cites a 2002California Regional PM10/PM-2.5 Air Quality Study (2002 CRPAQS Study) thatestablished adust-generating wind speed threshold of 17.8 mph to support its conclusion that these wind speeds were sufficient
to erode sojls and entrain dust into the atmosphere

as well as to exacerbate the entrainment ofdust from the anthropogenic activities. See ourproposal
at 72 FR at49052.

13As will be discussed further below, EPA uncovered an error in the reporting ofthe meteorological data fromLemoore. The data for Lemoore winds were reported in the State's documentation in PDTas opposed to the other meteorological andPM-10 concentration data which were reported inPST. This means that the wind speeds increased an hour earlier than had previously been reported in the State's documentation. Therefore when Earthjustice refers
to wind data from Lemoore at 6a.m. and 7 a.m., the actualtimes were 5 a.m. and 6 a.m. PST.

14 Hourly concentrations recorded by PM-10 continuous monitors are reported in the beginning hour.That is, anhourly average concentration calculated from readings taken between the hours of7 a.m. and 8 a.m. would be reported as the
average hourly concentration for 7 a.m. 15 In October 2006,the SJVAPCD began the routine submittal ofcontinuois PM-10 data to EPA's AQS database. These data are recorded with

a special purpose Federal EquivalentMethod (FEM) monitor and the Districtbegan submitting these data in response to new requirements contained in EPA's revised monitoring regulations (71 FR 61236, October 17, 2006). Prior to thisregulation revision, air monitoring agencies were not required to submit special purpose monitoring data to the AQS database. Therefore, the amount ofcertified pollutant data available for our analysis is limited
to October 1,2006 through September 30, 2007.

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TABLE 2.-CORCORAN HOURLY CONCENTRATIONS ON SEPTEMBER 22, OCTOBER 25, OCTOBER 26 AND OCTOBER 27, 

### 2006-Continued
September 22, October 25, October 26, October27, Hour (standard time) 2006 2006 2006 2006 (conc. gg/m 3) (conc. gg/m 3) (conc. gg/m 3 ) (conc. gg/m3)

6

....................................................................................................................... 170 269 194 221 7
............................................................................................................... : ....... 306 346 232 184 8

....................................................................................................................... 519 651 115 158 9

....................................................................................................................... 531 674 66 149 10

..................................................................................................................... 725 777 53 107 11

..................................................................................................................... 695 794 92 117 12

..................................................................................................................... 521 681 128 86 13

..................................................................................................... ................. 318 580 128 70 14

..................................................................................................................... 276 510 133 91 15

..................................................................................................................... 247 302 115 69 16

..................................................................................................................... 269 179 126 87 17

..................................................................................................................... 283 184 152 116 18

..................................................................................................................... 258 180 151 140 19

..................................................................................................................... 223 178 145 116 20

..................................................................................................................... 150 166 161 126 21

.................................................................................................................... 144 201 147 118 22
..................................................................................................................... 138 183 124 141 23

..................................................................................................................... 144 150 130 105
Dailyaverage
........................................ ................................................... 261 304 137 116
Source: EPA Air Quality System Database, "Natural Event Documentation, Corcoran, Oildale and Bakersfield, California, September 22, 2006" San Joaquin Valley Unified Air Pollution Control District, April20, 2007 and "Natural Event Documentation, Corcoran and Bakersfield, California, October 25,2006," San Joaquin Valley Unified Air Pollution Control District, April 23, 2007.

As can be seen from Table 2, early morning hourly concentrations on October 26 and 27, 2006 were comparable to morning hourly values on September 22 and October 25, 2006. All ofthese days recorded high early morninghourly values. However, the hourly concentrations on September 22 and October 25, 2006 continue to increase throughout the morning and into the afternoon and evening while the hourly concentrations for October 26 and 27 begin to decrease after hour 7 and then laterincrease slightly in the afternoon and evening. As discussed above, we believe the increasing concentrations forthe morning and afternoon for September 22 and October 25 are associated with an increase in hourly wind speeds, as measured in Lemoore. Even ifwe assumethat several ofthe hours ofhigh early morning concentrations at Corcoran on September 22 and October 25 were caused by something other than windblown dust, we have shown that there would not have been an exceedance ofthe 24-hour NAAQS that day without the subsequent high hourly concentrations that werecaused by windblown dusttransported from the Lemoore area.

Moreover, an evaluation of meteorology inthe Lemoore area on October 26 and 27, 2007 shows that the wind conditions on September 22 and October 25, 2006 were much different from October 26 and 27, days that had high morning concentrations but ultimately didnot exceed the 24-hour NAAQS. Table 3 below summarizes this information.

TABLE 3.-CORCORAN HOURLY PM-10 CONCENTRATIONS AND LEMOORE HOURLY WIND SPEEDS FOR SEPTEMBER 22,

OCTOBER 25, OCTOBER 

### 26 AND OCTOBER 

### 27, 2006

September 22, 2006 October 25, 2006 October 26, 2006 October 27, 2006

Hour Lemoore Lemoore Lemoore Lemoore Conc. wind- Conc. wind- Conc. wind- Conc. windjig/m3) speed (jig/in3) speed (jig/ 3) speed (lig/m3) speed (mph) (mph) (mph) (mph)

0

....................................................................... 1

....................................................................... 2

....................................................................... 3

....................................................................... 4

....................................................................... 5

....................................................................... 6

....................................................................... 7

....................................................................... 8

....................................................................... 9

....................................................................... 10

..................................................................... 11

..................................................................... 12

..................................................................... 13

..................................................................... 14

..................................................................... 15

....................................... 16

............................................. ........ 12 9 10 8

- 10 8 21 21 28 29 23 17 17
21 14 5 10 

### 14697

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TABLE 3.--CORCORAN HOURLY PM-10 CONCENTRATIONS AND LEMOORE HOURLY WIND SPEEDS FOR SEPTEMBER 22, 

### OCTOBER 25, OCTOBER 26 AND OCTOBER 27, 2006-Continued

September 22, 2006 October25, 2006 October26, 2006 October27, 2006

Hour Lemoore Lemoore Lemoore Lemoore Conc. wind- Conc. wind- Conc. wind- Conc. wind

### jig/m3 ) 

### speed (jig/m3) 

### speed (ig/m3) 

### speed (jig/m3

### ) speed (mph) (mph) (mph) (mph)

17

.................................. 283 9 184 3 152 3 116 5 18

.................................................................... 258 6 180 6 151 5 140 6 19

..................................................................... 223 8 178 8 145 7 116

................ 20

..................................... ... ....................... 150 7 166 9 161 6 126 8 21

.................................... ............................ 144 9 201 8 147 8 118 0 22

..................................................................... 138 0 183 8 124 8 141 3 23

..................................................................... 144 7 150 130 6 105 8
Daily Average

........................................... 261 304

.............. 137

.............. 116

........ Source: EPA AQS Database, Mesowest historical meteorological data, Mesowest, http://www.met.utah.edu/mesowesti

From this tabulation we can see that while hourly concentrations measured
at Corcoran exceeded the level ofthe NAAQS during the morning hours on all four days, it was only on September 22 and October 25, 2006 that sustained high winds inthe central SJV, represented by data from the Lemoore
area, generated enough fugitive dustto

cause an increase in the hourly concentrations in Corcoran recorded at and after 7 a.m. PST on September 22 and at and after 6 a.m. PST on October 25. These increases inhourly concentrations throughout the morning hours were a result ofthe high winds that occurred inthe Lemoore area. Therefore it is.incorrect to conclude, as Earthjustice does, that the State cannot show acausal connection between the winds and the 24-hour PM-10 exceedances at Corcoran on September 22, 2006 simply because the monitor recorded an hourly concentration above the level ofthe NAAQS at the same time winds in the Lemoore areabegan to exceed the threshold wind speed. Further, contrary to Earthjustice's contention, the winds at Lemoore on October 25, 2006 exceeded the threshold for entrainment prior to the time that increased concentrations were recorded at Corcoran and likely affected those concentrations.

Finally, the timing ofthe wind speeds shows an increase an hour earlier than

was previously reported, andthus a corresponding earlier impact onthe monitor. In evaluating the State's documentation we uncovered an error inhow the meteorological data from the Lemoore meteorological station was reported. Inboth its April 20, 2007 "Natural Event Documentation, Corcoran, Oildale and Bakersfield, September 22, 2006," and its April 23, 2007 "Natural Event Documentation, Corcoran and Bakersfield, October 25, 2006," the District reported the Lemoore meteorological data in PDT as opposed
to PST. This was confirmed when EPA independently obtained data forthe Lemoore meteorological monitoring station. As noted previously in Table 1, all State and local ambient air pollutant monitoring equipment in California operates on PST yearround and is never adjusted forDaylight Savings Time. Therefore, the information presented in Table 3of the State's April 20, 2007 documentation and Table 1 ofthe State's April 23, 2007 documentation incorrectly lists the time when winds in Lemoore reached the threshold wind speeds.

As can be seen in Table 3 above and Tables 4 and 5below, whichreflect the proper times for reported wind speeds,

on September 22, 2006 winds at Lemoore reached 21 mph, exceeding the threshold wind speed, at 6 a.m. PST, whichwould be 7 a.m. PDT. On October 25, 2006 winds atLemoore reached 22 mph at 5 a.m. PST, which would be 6

a.m. PDT. This adjustment strengthens the State's demonstration by showing that the winds inLemoore affected the PM-10 concentrations at Corcoran and Bakersfield an hour earlier than originally reported in the documentation.

Comment 11: Earthjustice asserts that the onerun ofthe model that EPA relies

on demonstrates that there is no connection between-the events in and around Lemoore and the exceedances measured in Bakersfield and Oildale.

Response 11:The model to which Earthjustice refersis the Hybrid SingleParticle-Lagrangian Integrated Trajectory model (HYSPLIT). However, contiary to Earthjustice's assertion, EPA did not rely onthe State's HYSPLIT analysis to make its decision to concur with the State's demonstration ofcausal connection. Rather, in its proposal, EPA noted the limitations ofthe HYSPLIT model, describing it merely as offering

some support to the State's demonstration that winds were ofthe appropriate intensity and direction to

move a plume ofdust from the central SJV to the Bakersfield area. 16 See 72 FR
at 49052. EPA is concurring with the State's causal connection demonstration based on actual meteorological data recorded on September 22 and October 25, 2006 which show winds ofthe appropriate intensity and direction occurring at the appropriate times.

The State's demonstration included actual meteorological data that showed that there were wind speeds between Corcoran and Bakersfield that exceeded the threshold wind velocities. For example, the State's demonstration for September 22 included meteorological data from amonitoring station in Alpaugh (15 miles SSE ofCorcoran) which showed winds in excess ofthe 18 mph threshold at 9:00 am PST and in the 15-16 mph range until 12 pm PST. Wind gusts at Bakersfield Meadow Field Airport also approached the threshold wind speed, with a gust speed of 17 mph recorded at 12:30 p.m.PST. The hourly concentrations inthe Bakersfield

area began to exceed the level ofthe PM-10 NAAQS at noon and stayed above 200 hg/m 3 for the remainder of the day. We discussed the transport of dustfrom the Lemoore and Corcoran

16The Oildale monitoring site does not record hourly PM-10 concentrations but usesamanual PM-10 sampler that provides only 24-houraverage concentrations. The Bakersfield-Golden State Highway monitoring site utilizes both a manual samplerfor average 24-hour PM-10 concentrations andacontinuous PM-la analyzer to provide hourly concentrations. Since the Bakersfield-Golden State Highway site andthe Oildale site arerelatively closeto each other(3.5 miles apart), we believe it is appropriate to use the Bakersfield-Golden State Highway continuous analyzer tocharacterize the temporal distribution ofhourly concentrations at both sites.

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areas in our proposal at 72 FR at49052 for September 22 and at49055-49056 for October 25. As we indicated, the winds between Lemoore and Corcoran and Corcoran and Bakersfield were sufficient to keep entrained dust suspended so that it could be transported.

As part ofour review ofthe State's documentation we researched whether any other publicly available meteorological data supported the State's demonstration and found that wind data collected atAllensworth State Park (20 miles SE ofCorcoran) also recorded wind speeds on September 22, 2006 in excess ofthe 18 mph.While
most ofthe wind speeds recorded in Alpaugh and Allensworth State Park in the late morning and afternoon hours

- did notexceed the threshold wind speed, we believe these wind speeds. 

### were sufficient totransport suspended PM-10 from the Corcoran area to the Bakersfield area. See ourproposed rule at 72 FRat49052. The wind direction from all ofthe sites on September 22 is consistent with the south; southeast transport ofdust (i.e., winds from the north and northwest)from the Lemoore

area to Corcoran and the Bakersfield

area as demonstrated byTable 4below.

TABLE 4.-SEPTEMBER 

### 22, 2006 DAYTIME HOURLY WINDSPEEDS AND CONCENTRATION DATA FOR THE CENTRAL AND SOUTHERN SJV

Lemoore Corcoran Allensworth State Park Bakersfield Horconc. Alpaugh WS*/WD WWDconc. WS/WD/gusts (ggfl, WSIWD (jg/m 3)

6

............. 21/NW

.................................... 170 5.5/W

................... ..................... ..... 74 7

............. 21/NW

..................................... 306 3.3/N SW

............................. 6/NNE

........................................ 104 8........

.... 28/NNW/35

..................... 5....... 519

........ 20/NNW

...................................... 78 9

............. 29/NNW/37

............................. 531 19.1/NNW

.............................. 35

................................................ 114 10

........... 23/NW/30

................................ 725 15.2/NNW

............... ........................... 103 11

........... 17/NNW/24

............................. 695 15.5/NNW

.............................. 8/NW

.......................................... 139 12

........... 17/NNW/25

............................. 521 16.1/NW

................................. ND

............................................... 168 13

........... 21/NNW

.................................. 318 13.6/NW

................................ 2/3

............................................... 196 14

........... 14/NNE

................................... 276 12.1/NW

................................. 7/NW

........................................... 239 15

........... 5/N

.......................................... 247 12.1/NW

................................. 8/WNW

........................................ 294 16

........... 10/N

........................... 269 10.2/NW

................................. 7/NNW

........................................ 285 17

........... 9/NNW

.................................... 283 9.7/NNW

................................ 5/NNW

........................................ 281 18

........... 6/N

......................................... 258 5.5/NNW

............................... 1I/WSW

..................................... 270

ND--No Data. Source: "Natural Event Documentation, Corcoran, Oildale and Bakersfield, California, September 22, 2006," San Joaquin Valley Unified Air Pollution Control District, April 20, 2007; "Addendum, Natural Event Documentation, Corcoran, Oildale and Bakersfield, California, September 22, 2006," San Joaquin Valley Unified Air Pollution Control District, May 23, 2007; Mesowest historical meteorological data, Mesowest, http:// www.met.utah.edu/mesowest.

*Wind Speed data at Alpaugh adjusted to 10 meter AGL based on conversion formula in the "Addendum, Natural Event Documentation, Corcoran, Oildale and Bakersfield, California, September 22, 2006," San Joaquin Valley Unified Air Pollution Control District, May 23, 2007 at 13.

For October 25, the State included all available meteorological data in its documentation. 17These data support the demonstration that winds between' the Corcoran and Bakersfield areas were sufficient to transport dust on October 25. We believe that thewind speed and direction data collected atAlpaugh and Bakersfield Meadow airport, while not exceeding the threshold wind speed, show that the winds in this portion of the SJV on October 25 were sufficient to transport suspended PM-10 from the Corcoran area to the Bakersfield area. See our proposed rule at 72 FRat 49052. The wind direction from all ofthe sites during the daytime hours on October 25 is consistent withthe south, southeast transport ofdust (i.e., winds from the north and northwest) from the Lemoore

area to Corcoran and the Bakersfield

area as demonstrated by Table 5 below.

TABLE 5.-HOURLY DAYTIME WINDSPEEDS AND CONCENTRATION DATA FOR CENTRAL AND SOUTHERN 

### SJV ON OCTOBER 

### 25, 2006

Lemoore Corcoran Bkrsfld Meadow Airport Bkrsfld conc. conc. Alpaugh WS*/WD WS/WD (gig/m3) Hour WS/WD/gusts (jig/m3)

22 NNW /30

............................... 22/NNW/32

............................... 26/NW/36

.................................. 29/NNW/39

.............................. 31/NW/37

.................................. 30/NW/40

.................................. 28/NNW /38 .: ............................. 26/NNW/35

............................... 22 NNW /31

............................... 20/NW /26

................................. 14/NNW

.................................... 3/N

......................... 3.5/SSW

................................... 2.9/W

........................................ 5.6/NW

..................................... 17.0/NNW

................................ 16.5/NNW

................................ 16.8/NNW

................................ 15.6/NNW

................................ 14.8/NNW

..:

.................... 13.2/NNW

.................... 13.3/NNW

....................... ........ 12.7/NNW

................................ 6.5/NW

..................................... 5/ESE

..................................... 6/E

.......................................... 0

............................................. 10/NW

.................................... 9/WNW

................................... 12/W

....................................... 12/WNW

................................. 6/ND

....................................... 7/ND

....................................... 7/NW

...................................... 3/WNW

................................... 5/NW

....................... 97 89 88 123 148 177 195 222 415 406 393 416

2See "Natural EventDocumentation, Corcoran and Bakersfield, California, October 25, 2006," April 23,2007 at 44-74. 6

............. 7

............. 8

............. 9

............. 10

........... 11

........... 12

... ....... 13

........... 14

........... 15

........... 16

........... 17

........... 

### 14699

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### /Rules and Regulations

TABLE 5.-HOURLY DAYTIME WINDSPEEDS AND CONCENTRATION DATA FOR CENTRAL AND SOUTHERN SJV ON OCTOBER 25, 2006-Continued

Lemoore Corcoran Bkrsfld Meadow Airport Bkrsfld conc. Hour WS/ND/gusts conc. Alpaugh WS*/WD WS/WD (lgg/m 3) (gig/m 3)

18

........... 6/N

............................................ 180 4.4/WNW

.................................. 3/NW " 403

ND-No data available. Source: "Natural Event Documentation, Corcoran and Bakersfield, California, October 25, 2006," San Joaquin Valley Unified Air Pollution Control District, April 23, 2007; Mesowest historical meteorological data, Mesowest,http://www.met.utah.eduImesowest/.

*Wind Speed data at Alpaugh adjusted to 10 meter above ground level (AGL) based on the conversion formula in"Natural Event Documentation, Corcoran, Oildale and Bakersfield, California, October 25, 2006," San Joaquin Valley Unified Air Pollution Control District, April 23, 2007 at 25.

In its documentation the State also included the results ofa HYSPLIT model run bythe District to identify

source regions for the parcels ofair that impacted the Corcoran and Bakersfield monitors on September 22 and October 25, 2006. The District explicitly stated that the models were not intended to quantify particulate concentrations but simply .wereused to support its view of the-origin ofthe particulate matter that impacted themonitors at Corcoran and Bakersfield. As stated in the proposed rule, EPA agrees'that thismodel run supports the conclusions drawn from the meteorological data presented. See 72 FR at49052 and 49056.

Inits comment letter on the proposed affirmation rule, Earthjustice relies on its own computer simulations using the HYSPLIT model and appears to claim that,based on its own HYSPLIT analyses, the winds inthe Lemoore area could nothave carried sufficient quantities ofparticulate matter to Bakersfield to cause exceedances ofthe PM-10 NAAQS. In orderto evaluate Earthjustice's HYSPLIT analyses, EPA also performed computer simulations using the HYSPLIT model. However, we took a different approach because we believe that Earthjustice's HYSPLIT analyses do.not represent a comprehensive depiction ofthe dust event."'

While Earthjustice used trajectories starting at zero meters in height and took atwo-dimensional aproach in assessing the wind event, we took a

more appropriate three-dimensional approach. The EPA approach recognizes that the dust did not stay at zero meters inheight above ground but instead

'EPA does agree in part with theJan Null declaration (EC, Exhibit H) in which he states that the data usedby the District in the HYSPLIT model, EDAS (ETA Data Assimilation System) meso-scale data, is toocoarse to account fullyforboth the complex terrain in and around the SJV and for the closeproximity ofthe stations being examined. However, Earthjustice and EPA also used theEDAS meso-scale data which are ofsufficient resolution
to account for the general overall wind flow in the southern SJV and thus provide a coarse simulation ofwind trajectories within the Valley. mixed up higher into the atmosphere where stronger winds occurred that caused the transport to be faster than Earthjustice's HYSPLIT analyses indicated. For September 22 and October 25, 2006, for the morning start times, EPA ran trajectories atthree heights: 10 meters, 100 meters and 250
meters. These heights were used to approximate the transport from near the surface, near the middle and near the top ofthe mixed layer 19 as shownby the HYSPLIT model.

On September 22, 2006,based onthe meteorological data and our HYSPLIT

runs, the high winds thatbegan inthe Lembore area around 6 a.m. PST eroded apd thentransported dust that startedto affect the PM-10 concentrations measured inthe Corcoran areaby 7 a.m. PST. See Figure 1, "Forward Trajectories at 10, 100, &250meters, Lemoore Area to Corcoran, September 22, 2006, 6 a.m. to 8 a.m. PST." 20 From Corcoran and eastward, some of the dust
may have been transported more towards the Sierra foothills. See Figure 2, "Forward Trajectories at 250meters, Lemoore to Corcoran and Bakersfield, September 22, 2006, 6 a.m. to 1p.m. PST." West ofCorcoran, the dustwas transported southward towards Bakersfield, beginning to affect that area between the hours of 12 p.m. and 1p.m. PST. See Figure 2 and Figure 3, "Forward Trajectories at 10, 100, &250 meters, Lemoore Area to Bakersfield, September 22, 2006, 6 a.m. to 1p.m. PST." Based on hourly PM-10 values, the peak concentration ofdust, 725 pRg/

m3

, occurred at about 10 a.m. PST in Corcoran and a PM-10 value of294 Itg/

m3 occurred at about 3- p.m. PST in

19The mixed layer is the unstable layer ofthe atmosphere in direct contact with the surface ofthe Earth. The daytime mixed layer is characterized by vigorous turbulent mixing. This means that air or dust laden air atany height within the mixed layer

can impact the surface due to themixing caused by turbulence.

20The EPAFigures referenced in this final rule

are available in the docket forthis rulemaking action and are listed in section I.C.below. Bakersfield. See Table 4 above. See also

our response to comment 21 below.

On October 25, 2006, the scenario was similar'to September 22, 2006. EPA's HYSPLIT runs support a finding that the high winds that began in the Lemoore

area around 5 a.m. PST eroded and then transported dustthat started to affect the PM-10 concentrations measured in the Corcoran areaby about 6 a.m. PST. See Figure 4, "Forward Trajectories at 10, 100, &250meters, Lemoore Area to Corcoran, October 25, 2006, 5 a.m. to 7

a.m. PST." FromCorcoran and eastward, some ofthe dust may have been transported more towards the Sierra foothills. West of Corcoran, the dust was transported southward towards Bakersfield, starting to affect that area between 11 a.m. and 12 p.m. PST. See Figure 5, "Forward Trajectories at 250 meters, Lemoore to Corcoran and Bakersfield, October 25, 2006, 5 a.m. to 11 a.m. PST" and Figure 6," Forward Trajectories at 10, 100, & 250meters, Lemoore Area to Bakersfield, October 25, 2006, 5 a.m. to 11 a.m. PST." The peak concentration of dust in Corcoran occurred around 11

a.m. PST with a PM-10 value of 794 gg/

M3

. The peak concentration ofdust in Bakersfield was more obscure with a peak atabout 5 p.m. PST and aPM-10 value of416 gg/m 3

. See Table 5 above.

EPA believes that our HYSPLIT analyses depict more accurately than Earthjustice's runs the windblown dust
events ofSeptember 22 and October 25 because, in addition to accounting for thevarious heights above ground level,

we accounted for the wind flows within the Valley more comprehensively. We recognized that the winds over the
eastern portion of the Valley tended to

move towards the east, winds over the
western portion of the valley tended to

move more towards the south, and that there was a transition area inbetween where winds moved southeast directly from the Lemoore areato Bakersfield. See Figures 2 and 5 above. Thus we believe that our HYSPLIT analyses were sufficient to provide a general overview ofthe direction and speed of dust

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transport inthe San Joaquin Valley and supportthe contention ofdust transport from the Lemoore area to the Corcoran and Bakersfield areas. Our analyses are alsoin general agreement with the measured wind data providedby the State which do accountfor the complex terrain ofthe Valley.

We note again that our concurrence with the State's causal connection demonstration isbased on the meteorological datafor September 22 and October 25, 2006 discussed above. Webelieve the HYSPLIT model supports this demonstration by showing thatthe winds were ofthe appropriate intensity and direction to move a plume ofdust from the central SJVto the Bakersfield areas onthose days.

-



### Comment12:Earthjustice claims that the exceedances inthe SJVcannot be 

### deemed to be in excess ofnormal historical fluctuations because they

occur regularly and ata similar level everyfall and are therefore no different fromthe exceedances used to designate the SfVnonattainment inthe firstplaco. Thus Earthjustice believes there are no "unusual activities" asEPA states, because the exceedances atissue here

were caused bythe same dustgenerating activities that cause exceedances every year:

Response 12:As we discussed in our proposed ruleat 72 FR 49052, forEPA to concur with a state's claim that an exceptional event caused an exceedance, the state must show that the event is associated with concentrations "thatarebeyond the normal historical fluctuations. See 40 CFR50.14(c)(3)(iii)(C).

When the SJV was designated nonattainment for PM-10 in 1991 by operation oflaw (56 FR 11101, March 15, 1991), the District hadnot 

### implemented the BACM forPM-10 that

are currently inplace. Since 1991, the State ofCalifornia andthe SJVAPCD have adopted many rules and rule amendments that haveled to significant reductions in PM-10 and oxides of nitrogen (NOx) emissions. These rules include, as discussed above, BACM for fugitive-dust sources such as unpaved and paved roads, vacant lots, construction sites, etc. (RegulationVIII) and BACM foragricultural sources (Rule 4550-Conservation Management Practices). See Section 8, "Natural Event 

### Documentation, Corcoran, Oildale and Bakersfield, California, September 22, 2006," April 20, 2006. These BACM 

### rules for fugitive dust and agricultural

sources were adopted and implemented inmid- tolate 2004. See 71 FR 8461 and 71 FR 7683. Given the vastchanges in regulatory requirements forPM-10 sources, the dust-generating activities in the early 1990's are not, as Earthjustice suggests, comparable to those after the full implementation ofBACM inthe SJV. Therefore we do notbelieve that the September 22 and October 25, 2006 21 exceedances are the result ofthe

same fype ofdust-generating activities that caused the area to originally become nonattainment. Nor do we believe that Earthjustice has substantiated its claim thatthey are.

We originally evaluated whether the September 22 and October 25, 2006. exceedances exceeded normal historical fluctuations inour proposed rule. See 72 FR at49053 and49056. In response toEarthjustice's comment on the proposed rulethat this EER criterion had notbeen satisfactorily demonstrated by the State's documentation, EPA undertook a further analysis ofthe data collected at the sites that exceeded the 24-hour PM-10 NAAQS on September 22, 2006 (Corcoran, Bakersfield-Golden State Highway and Oildale) and October 25, 2006 (Corcoran and BakersfieldGolden State Highway). EPA included data from 1993 to 2006 inour analysis.72 Our statistical analysis 

### shows the annual percentile values of the data from each ofthe three sites. In the preamble to our EER, we state that

a comparison ofthe exceedance data to the historical 95th percentile values is appropriate for determining the level of evidence or documentation a state needs to provide in orderfor EPAto concur with its flagging request. Extremely high concentrations relative to the 95th percentile values would require a lesser
amount ofdocumentation to demonstrate that an event affected air quality. See 72 FRat 13569.

For Corcoran, when we examine all 

### data collected since 1993,23 

### itis clear that the 95th percentile values have consistently beenbelow the level ofthe 24-hour PM-10 NAAQS and since 1999 the Corcoran site has not recorded a 95th percentile value greater than 117

21Withrespect to the exceedances atthe Santa Rosa Rancheria,in the proposed rule EPAshowed that the concentrations measured duringthe construction activity were in excess ofnormal historical fluctuations andthataftercompletion of the paving projectaverage PM-10 concentrations droppedby more than 50 percent. 72 FR at49062.

221993 was chosen as the startingpoint fordata analysis because that is the year that the SJV was classified as aserious PM-10 nonattainment area.

23 From 1993 through 1998, the Corcoran site collected PM-10 data on aonce every sixth day schedule using a Federal Reference Method (FRM) monitor. Beginning in 1999 the Corcoran PM-10 site hasbeen collecting data onaonce every third day schedule using FRM monitors. InOctober2006 the SJVAPCD began operatingacontinuoug monitor designated as aFederal Equivalent Method (FEM) monitorat the siteto provide everyday PM-10 data to the public,The State and SJVAPCD reportall data from these monitors to theEPA's AQS database. 

### g/rm3



### .The 95thpercentile talue recorded at Corcoran in 2006 was less than 100jg/m 3

. Therefore, ouranalysis ofall the data collected at Corcoran over the past 14 years indicates that the September 22 and October 25, 2006 exceedances were clearly beyond the normal range ofannual concentrations recorded at this site. See Figure 7, "Annual Peak Day PM10 Concentrations
atCorcoran."

Aswith the Corcoran data, we performed a statistical analysis ofthe data collected at the Bakersfield-Golden State Highway site using data from 1993
to 2006 and calculated the annual percentile values. From this analysis it is clear thatthe 95th percentile values atBakersfield were consistently less than the level ofthe 24-hour PM-10 NAAQS. In 2006 the 95th percentile value atBakersfield-Golden State Highway was 101 jig/m 3

. Therefore our analysis ofthe Bakersfield-Golden State Highway data.shows that the September 22 and October 25, 2006 exceedances

werebeyond the normalrange ofdata recorded atthis site during the past 14 years. See Figure 8, "Annual Peak Day PM10 Concentrations at Bakersfield."

Finally, our analysis ofthe data collected atOildale also shows that the exceedance recorded at that site on September 22, 2006 was outside the normal range ofhistorical values. As with the other two sites discussed above, the 95th percentile values recorded atOildale during the past 14 years were consistently below the level ofthe NAAQS and the 95th percentile value in 2006 was 111 gg/m 3

.Again, our analysis ofthe Oildale data indicates that the September 22, 2006 exceedance recorded atthis site was outside the normal historical fluctuation ofdata for the past 14 years. See Figure 9, "Annual Peak Day PM10 Concentrations at Oildale."

Therefore, our analysis ofall the annual data from 1993 through 2006 shows that the September 22 and October 25, 2006 exceedances are in

excess ofnormal fluctuations.

To address Earthjustice's specific

concern that these exceedances occur routinely in the fall months, defined by Earthjustice as the months of September, October and November, 2 4

we performed the same statistical test

onthe Corcoran data using only those values recorded during those months. From this test it is clear that the 95th percentile values forall years since 1998 do not exceed the level ofthe 24-hour PM-10 NAAQS. The highest 95th percentile value since 1998 was a 146 gg/m 3 recorded in 2003. Again, this

2 4 EC at 15. II I II I | I I I II I 

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analysis demonstrates that the September 22 .and

### October 25, 2006 

### exceedances recorded in Corcoran, even whenwe use seasonally adjusted data,

were in excess ofthe normafhistorical fluctuations. See Figure 10, "Annual Peak FallDay PM10 Concentrations at Corcoran."

At the Bakersfield monitor, 95th percentile values for the fall months havebeen lower than the level of24- hour PM-10 NAAQS since 2000, with the highest 95th percentile value recorded in that year at 145 gtg/m 3

.In 2006, thefall months' 95th percentile value was 100 R.g/m 3



### . These values show that the exceedances measured on September 22 and October 25 were outsidethe historical fluctuation ofdata for the fall months. See Figure 11, "Annual PeakFall bay PM1O Concentrations atBakersfield."

Finally for Oildale, our analysis ofthe fall 95th percentile values shows that since 1996 the 95th percentile values have not exceeded the level ofthe NAAQS and 1996 hadthe highest 95th percentile value (138 Lg/m 3), with the exception ofthe September 22, 2006 concentration of 162 jtg/m 3

.Even though the 95th percentile value in the fall of2006 exceeded the level ofthe

- NAAQS, when we look atthe historical fall data forOildale this value does stand out as outside the normal range. See Figure 12, "Annual Peak Fall Day PM10 Concentrations atOildale."

Therefore, our analysis ofthe data from 1993 through 2006 for the months ofSeptember through November shows that the September 22 and October 25, 2006 exceedances were in excess of normal fluctuations.

Comment 13:Earthjustice argues that EPA cannot make the required "but for" showing for the locations other than the SRR because either the model shows that the winds did notblow toward the monitors orthe monitoring data show that the standard was being exceeded

even before the alleged dust-laden winds arrived.

Response 13:With respect to the September 22, 2006 exceedance, see our responses to comments 10, 11, 16 and 21. With respect to October 25, 2006 see

our responses to comments 10, 11 and 43. We also discussed the "but for" demonstration included inthe State's documentation in detail in our proposed action. See 72 FR 49053, 49056-49057.

Comment 14:Earthjustice also argues that to make its "but for" showing EPA asserts that no "unusual activities" occurred during the exceedance period and implies that something "extra" must have happened which would

mean that an area would either have violations every day or never and that EPA would then have to conclude that unless an area violates every day, any violation mustbe the product ofsome exceptional, nonrecurring event. Earthjustice believes that EPA's reliance

onthis type ofargument to make the "but for" claim is arbitrary and capricious."

Response14:Earthjustice takes out of context EPA's consideration ofthe fact that there were no other unusual activities atthe time ofthe September 22 and October 25, 2006 exceedances to draw some extreme conclusions, such as that the Agency would have to conclude "that unless an area violates every day, any violation mustbethe product of

some exceptional nonrecurring event." In this connection, Earthjustice misunderstands EPA's application of the weight ofevidence approach to the "but for" demonstration. In the



### . preamble to the EER, EPA explained that itwould use a "weight ofevidencebased approach to demonstrate that there would not have been an exceedance or violation but forthe event." 72 FR at 13570-13571. EPA explained thatthrough analyses it was possible to demonstrate that an exceedance would not have occurred but forthe event; however, this analysis does not require a precise estimate of the estimated air quality impact from the event. 72 FR at 13570.

In applying this weight ofevidence approach, EPA considered the totality of circumstances surrounding the events forthe exceedance days. EPA included inits consideration, an evaluation ofthe

coarse particles, information about geologic dust, values representing

excess geologic contributions, comparison of"adjusted" PM-10 values with typical average concentrations during similar periods, information about control measures, readings on daysbefore and after the exceedance days, and whether any unusual or out ofthe ordinary activities occurred on such days. See 72 FR at 49053. Monitor readings on the days before and after the
event days indicated no violations. EPA therefore looked to see if on the specific event days there were activities that

were different orunusual as compared
to the days when there were no exceedances inorder to rule those in or out as contributing to the exceedance. Contrary to Earthjustice's contention that any time there is aviolation EPA would conclude that it is due to some exceptional nonrecurring event, the lack ofunusual activities wasjust one ofthe factors that EPA considered in reaching its determination based on the weight of evidence analyses. Thus, EPA's consideration ofwhether ornot there

were unusual activities in this context is neither arbitrary nor capricious as Earthjustice claims.

2. Comments Specific to September 22, 2006-Corcoran, Bakersfield and Oildale

Comment 15:Earthjustice claims that in orderto show that an event'has affected air quality, a demonstration
mustbe made that the event "caused a specific airpollution concentration" and that the data to be waived are directly due to the event. Earthjustice asserts that the District did notprovide evidence that demonstrates how enough particulate matter pollution could have been generated in and transported from

one remote area ofthe SJV to multiple monitors in distant locations within the time period ofthe event. In this regard, Earthjustice states that while the District cites a study that allegedly establishes a threshold at which wind begins to erode PM (sustained winds of18 mph or gusts of 22.4 mph), there is no basis for the claim espoused by both the District and EPA that winds below thisthreshold velocity can then transport particulate matter pollution long distances. To support this assertion Earthjustice cites EPA's recent rulemaking (71 FR 61f44, 61146, October 17, 2006) establishing

new PM standards in which EPA concluded that "thoracic coarse particles generally deposit rapidly on the ground or other surfaces and are not readily transported across urban or broader areas."

Response 15:Earthjustice states that in order to show that an event affected air quality the State must quantify the amount ofPM-10 initially generated at

asource location. In ourproposed rule

we stated that this criterion (affecting air quality) is met by establishing that the event is associated with a measured exceedance inexcess ofnormal historical fluctuations, including background, and there is a clear causal connection between the event and the exceedance. 72 FR at 49051. We also discussed how these criteria were met. Id.at49051-49052.

Earthjustice seems to be suggesting that in orderto meet the criterion "affects air quality" the State should have used an air quality model such as AERMOD orCalPuff to show the behavior offugitive dust. In other words, Earthjustice is asking for a modeling demonstration that would show, quantitatively, that a given
amount (either in the form ofan emission rate or initial ambient concentrations at the source regions)

can produce a partic.ular concentration at areceptor point (e.g., monitoring site location). This type ofmodeling, at the scale Earthjustice is suggesting, is not an

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appropriate tool for use in this type of application because it cannot be performed with any degree ofaccuracy.

The State included inits documentation theresults ofa study that determined the threshold wind speed needed to erode geologic material and entrain the resulting particles into the atmosphere. 2 5 Earthjustice states that there is no basis for the claimthat lower wind speeds could transport dust long distances.

While the State did not provide information from a specific study to demonstrate wind speeds sufficient to transport PM-10 suspended inthe atmosphere, EPA believes itis reasonable to conclude, as the State did, that if an 18 mph wind is sufficient to erode and entrain coarse particles into the atmosphere, a lower wind speed is sufficient to keep particles already entrained in the atmosphere suspended, and to subsequently transport them considerable distances. To erode geological material on the ground and

cause itto be suspended inthe air, winds must have enoughkinetic energy to overcome the attractive forces between particles, inaddition to gravitational forces. High winds also tend to cause large particles to collide with each other, making thembreak apart and become morelikely to be lifted up. Forparticles thathave already been lifted well above ground level, winds need only have enough occasional upward component (due to turbulence) to overcome gravitational settling. Also, winds aloft may have been stronger (andhad more turbulence) than suggested by the ground based
measurements.

As presented in Table 3 ofthe State's documentation, the wind speeds between Lemoore and Corcoran, measured at Corcoran, reached a maximum speed of11 mph between hours 6 and 12. See "Natural Event Documentation, Corcoran, Oildale and Bakersfield, California, September 22, 2006," San Joaquin Valley Unified Air Pollution Control District, April 20, 2007. Winds inthe region between Corcoran and Bakersfield, measured at Alpaugh and Allensworth State Park, reached 16 mph and 15 mph, respectively, between hours 10 and 16.26 EPA believes that wind speeds of this intensity were sufficient to transport PM-10 from the central SJV to the Bakersfield area.

Regarding Earthjustice's reference to the PM coarse NAAQS final rule,EPA

was noting the difference in expected transport distances for PM-2.5 versus PM coarse. Note that we stated that

coarse particles generallydeposit rapidly onthe ground orother surfaces and are not readily transported across urban or broader areas. 71 at 61146. When comparing PM-2.5 and PM coarse inurban settings itis true that PM-2.5 is a moreregional pollutant and can spread over great distances. PM coarse particles inurban areas, under meteorological conditions that do not involve high winds, generally are considered more ofa localized pollutant problem. The statement cited by Earthjustice was not meant to imply that under windy conditions PM coarse particles would notbe subject to transport. The exceedances that occurred in both Corcoran and the Bakersfield area on September 22 and October 25, 2006 werethe result of windblown and transported dust from a predominantly rural area.

Comment 16:Earthjustice provides a chartthat it states demonstrates the range ofsustained wind speeds in key

areas ofthe central and southern SJV on September 22, 2006 with corresponding hourly PM-10 concentrations. With respect to thischart, Earthjustice, citing EPA Raw Data Reports, asserts the following:

* * * there wasaperiod ofa few hours where the alleged wind speed threshold was exceeded at theLemoore Naval Air Station monitoring site,which is located rorthwest ofthe city ofLemoore. The maximum sustained wind speeds ranged from 21 to 29 milesper hourbetween thehours of7a.m. and 11 a.m., and again exceeded the alleged threshold at 1p.m. The maximum peak gusts (i.e., momentary bursts ofwind)recorded at the Lemoore NAS ranged from 30-40 miles perhourbetween the hours of9a.m. and 11

a.m.However,just 10 miles southeast ofthe

TABLE 6.-SEPTEMBER 

### 22, 2006 MORNING WIND SPEEDS AT METEOROLOGICAL SAN JOAQUIN VALLEY Lemoore NAS at the Santa Rosa Rancheria, sustained winds never got any higher than 14.1 miles perhour * * *.In Corcoran, sustained winds reached only 9.6 miles per hour, and Bakersfield experienced nothing stronger than 7.8 mile-per-hour sustained winds * * *.None ofthe winds experienced outside ofnorthwest Lemoore were capable oferoding soils and so none ofthese areas could have contributed any wind-entrained dust to the PM-10 concentrations recorded

on September 22, 2006.

Response 16:As discussed in our response to comment 10, the Lemoore wind speeds included in the Stae's documentation were reported inPDT and not in PST. The Corcoran and Bakersfield PM-10 hourly concentration data were reported in PST which means that the winds in Lemoore began to exceed the threshold wind speed at 6

a.m. PST. Thetimes for the wind speed data inthe Earthjustice chart need to be adjusted accordingly.

While we do nothave monitoring data at every location, contrary to Earthjustice's comment, there are data that show the threshold wind speed was exceeded notonly inthe Lemoore area but atother locations in the central and southern SJV on September 22, 2006. The Lemoore station showed the most intense wind speeds in the area and the data are used torepresent the conditions in the area centered around Lemoore. The nearest meteorological station to Lemoore is the Santa Rosa Rancheria monitoring station, located about 11 miles SE ofLemoore. However, the fact that the winds atthe SRR didnot exceed the threshold velocity does not
prove that there were no wind speeds above the threshold between Lemoore and Corcoran. We obtained wind data from other meteorological stations inthe central SJV such as Tranquility (30 miles NW ofLemoore), Selma (20miles NE ofLemoore), Kettleman Hills (20 miles SSW ofLemoore), Hanford Municipal Airport (17 miles east of Lemoore), Hanford (18,miles east of Lemoore) and Allensworth State Park (43 miles SW ofLemoore). Wind speed data from these sites are presented in the Table 6 below.
MONITORING STATIONS INTHE CENTRAL

Time Tranquility Selma Lemoore Kettleman Hills Hanford Airport Hanford ae Park (a.m. S ark PST) (hour/gust) (hour/gust) (hour/gust) (hour/gust) (hour/gust) (hour/gust) (hour)

6:20

........ 9/12

.................. 6:30

........ 10/10

........ 6/7

.................... N D

...................... /

......... ND
..................... 5/9

................. ND

......................... ND

.......... 4/10

.................. ND

......................... ND

............. 5/8

....................

25Subtask Memorandum, "3.3 How Well Do
Measurements Characterize Critical Meteorological Features," Dave Bush, T &B Systems, August 24, 2004. 26Wind speeds at Allensworth State park reached additional PM-10 was likely generated bywinds in 20 mph and35 mph athours 8 and 9. This indicates the regionbetween Corcoran andBakersfield. that while the area around Lemoore was identified

asthe source for the PM-10 on September 22, 2006, 

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TABLE 6.-SEPTEMBER 22, 2006 MORNING WIND SPEEDS AT METEOROLOGICAL MONITORING STATIONS INTHE CENTRAL SAN JOAQUIN VALLEY-Continued Time Allensworth (a.m. Tranquility Selma Lemoore Kettleman Hills "Hanford Airport Hanford Ae rk (hour/gust) (hour/gust) (hour/gust) (hour/gust) (hour/gust) (hour/gust) (hour)

6:45

........ 8/12

........ ......... 5/7

........... ND............ND

............. ND............ 5/8 3.................... 3 7:00

........ 9/11

......... 6/9

...........21............ 16/24

..................... 17/ND

............... 517

.................... 6 7:20

........ 13/12 : 716........7/6

........... ND

.......... ND
.......... NO

. "ND..........ND

.........5/11

.................. 7 7:35

......... 13114

................ 7/7

........... ND ND

............ ND

............. ND

.................... 5/11

.................. ND 7:45

........ 14/14

................ 8/9

.......... 28......*

........ . 17/24

..................... 15/ND

............... 7/10

.................. 38 8:05

........ 15/19

................. 10/10

......... 26..... 26

....... ND.............ND

.................... 8/12

.................. 5 8:15

........ 13/19

................ 12/10

.........31............ N

.................. ND
.................... 9/12

.................. 20 8:30

........ 21/20

................ 14/14

................ 28/35

......... ......................... ND/26

............... 9/17

................. 21 8:45

. 23/23

................ 8/16

.................. ND/35

.........ND

................ ND
.................... 7/18

.................. 9 9:00

........ 20/23

................ 12/15

................ 29/38

..........18

.............15/ND

............... 5/21

................ 2 9:20

........ 18/27

................ 12/18

................ 24/40

.......... .. ND............ND.......... 4/18

.................. 35 9:35

........ 21/25

................ 9/15

.......... ND............ND.............ND.......... 5/16

.................. 6 9:45

........ 17/25

................ 6/16

......... ND/37

... ...... ND...

............ ND.......... 8/18

.................. 2 10:05

...... 17/24

................ 9/13

.................. 23/ND

.........20/27

..................... 10/ND

............... 7/16

.................. 15 10:15

...... 17/26

................ 5/13

.................. N D

....................... N

D

......................... N

D

.................... 4/11

..................3 10:35

...... 17/23

................ 7/7

.......... ND

............ ND............ND.......... ND/13

........... :... 10:50

...... 14/23

................ 8/12

.................. ND/30

......... .. ND.......................ND

........... ND/13 0.............. 11:05

...... 16/21

................ 7/7

.................... 17/ND

.........17/32

..................... 10/ND

............... ND/11

...............ND 11:15

...... 12/22

................ 7/12

.......... ND

....................... ........... N
.................... ND

.................... 8 11:30

...... 1.4/20

................ 1/9

.................... NO

........................ NO

......................... NO

.................... N

O

.................... 10 11:35

...... 15/23

................ ND/8

................. ND/24

.........ND/24

..........ND.......... ND

......... ........... ND 11:45

...... N

D/23

............... 6/9

.................... NO

....................... NO

......................... ND
................... ND

........ 0....... 0 11:50

...... ND/23

................ ND/. N.............ND............N DD..

.......... ND......... ND

......... ND 12:00

...... ND/16

............... 0

............ 14/

....................... 17/ND

..........10/ND

............... ND

......... ND Source: Mesowest historical meteorological data, Mesowest, http://www.met.utah.edu/mesowest/. ND-No Data available.

Earthjustice includes data in its chart only from locations which had recorded lower wind speeds on the morning of September 22, 2006. We addressed the lower intensity winds atCorcoran and Bakersfield in ourproposed rule, and the fact that the winds between Lemoore and Corcoran and Bakersfield were capable ofkeeping in suspension the. particulate matter that the winds at Lemoore had suspended. See 72 FR at 49052. Earthjustice does not indude data from the other meteorological sites inthe general area ofthe central SJV that show winds that were comparable to those recorded at the Lemoore Naval Air Station meteorological site. Data from these other meteorological sites, as shown above, indicate that nearly all recorded hourly wind speeds on September 22, 2006 were in excess of the threshold wind speed of 18 mph between 6 a.m. and 12noon PST. Recorded gusts at some ofthese sites

were also inthe 20-30 mph range during the morning hours. Itis likely that there were other places along the path from Lemoore to Bakersfield that experienced wind speeds above the threshold velocity butthere were no wind instruments to document it.

Therefore, Earthjustice's statement that none ofthe winds experienced outside ofnorthwest Lemoore were capable oferoding soils is simply not true. Based on actual recorded wind data, wind speeds inthe central SWV on the morning of September 22, 2006were high not just inLemoore butthroughout thisportion ofthe Valley. Moreover, as pointed out above, even ifthe winds outside ofLemoore were notcapable of eroding soil, the winds between Lemoore and Corcoran and Bakersfield

were capable ofkeeping in suspension the particulate matter thatthe winds in the area around Lemoore had entrained.

Comment 17:Earthjustice states that

no attemptwas made to explain how high winds that began at 7a.m. on September 22, 2006 caused violating PM-10 levels ata monitor 25 miles away starting at 6 a.m.

Response 17:See responses to comments 10 and 11.

Comment 18:Earthjustice asserts that EPA failed to demonstrate that the concentrations measured on September 22, 2006 could have been caused by the wind-generated erosion ofsoils from agricultural and industrial sources in the Lemoore area. Earthjustice states that all EPA offered as evidence is a study establishing athreshold velocity at which soil erosion may begin to
occur, but that EPA has not analyzed whether the study's threshold wind speed is appropriate for the Lemoore

area. Earthjustice argues that the scouring ofsoilby winds depends on much more than simply the speed ofthe wind and that EPA has not attempted to analyze factors pertinent to fugitive dust generation such as the soil class and erodibility inthe Lemoore area, the types and stages ofcrop cover present atthe time the winds occurred, the specific activities occurring in the area that contributed to PM-10 concentrations, or the specific measures employed by sources toreduce or prevent wind erosion. Earthjustice maintains that this information should have been evaluated to help determine whether or not-thewinds in Lemoore could haverealistically generated the levels ofPM-10 observed on September 22, 2006.

Response 18:EPA has demonstrated that the concentrations measured on September 22, 2006 were caused by windblown dust generated in the Lemoore area. As-stated above in response to comment 10, the State's documentation included a threshold wind speed needed to erode soils and entrain the resulting particulate matter inthe atmosphere. This wind speed study was part ofthe 2002 CRPAQS Study. The wind speed study was performed inAngiola, California, which is located about 8 miles SW ofCorcoran and 34 miles SW ofLemoore. Based on the soil map included inthe State's documentation, the soiltype in Angiola is the same as those in Lemoore and Corcoran. See "Natural Event Documentation, Corcoran, Oildale and

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Bakersfield, California, September 22, 2006," SanJoaquin Valley Unified Air Pollution Control District, April 20, 2007 at 76. Thus the threshold velocity at which soil erodes identified inthe study is appropriate for the Lemoore and Corcoran areas.

Reviewing the graphic inthe State's documentation, we see that crop types throughout the areas in question are predominantly field crops. Id.at 77. Other sources in this rural portion ofthe SJV could include, but are not limited to, agricultural activities, unpaved roads and construction activity. These types of

sources are all subject to BACM. Id.at 32-33. These BACM are part ofthe approved serious area PM-10 plan for the SJV. See 69 FR 30006. Therefore, EPA didin fact evaluate the principal factors identified by Earthjustice, including wind speed, sources and whether they were controlled. See also

our proposed rule at 72 FR49051 and 49053. Comment 19:Earthjustice states that EPA must find that the documentation demonstrates a clear causal relationship between ameasured exceedance and the alleged event. Inthis respect, Earthjustice, relying on a declaration of Jan Null (Null declaration), argues that the District's documentation concocts a barely-plausible story ofsevere scouring by winds notmuch greater than the alleged minimum velocity for entrainment, followed by rapid transport from one remote west-Valley location (Lemoore) down to Corcoran, where huge amounts ofparticulate matter were deposited on the monitor in order to cause violations, yet enough pollution was kept entrained by much slower winds to continue on for 60 miles down to Bakersfield and Oildale in substantial enough quantities to also

cause violations inthose locations. Earthjustice concludes that this "story" is unsupported by reliable meteorological-evidence.

Response19:As discussed in EPA's proposed rule (72 FR 49046) and in responses to comments 11 and 16, the State did provide reliable meteorological data to support its demonstration that winds inthe central and southern SJV were ofthe appropriate intensity and direction to

cause and transport fugitive dust to the affected monitors at Corcoran and Bakersfield. EPA relied onthese data, as well as other publicly available data, to

concur with the State's request to find that the exceedances ofthe NAAQS on September 22, 2006 were due to an exceptional event.

Furthermore, Earthjustice mischaracterizes the data used to support this action. It is notthe case that winds were not much greater than the threshold wind speed of 18 mph; rather they were at times significantly higher and widespread inthe central SJV. See Table 6 above. Winds between Lemoore and Corcoran were ofthe appropriate direction and intensity to transport windblown dustto Corcoran, 25 miles away. Winds inthe areas south ofCorcoran and north ofBakersfield

were ofsufficient intensity to transport suspended PM-10 the 55 miles from Corcoran to Bakersfield. 27 Thetiming, direction and intensity ofthe winds and hourly PM-10 concentrations at Bakersfield all support the demonstration oftransport presented by the State. Based on the weightof evidence presented, EPA hasconcluded the State's documentation shows aclear causal relationship between the wind
event and the exceedances in contrast to the "barely-plausible story" Earthjustice alleges.

Comment 20:Earthjustice states that theFigure 1 in theNull declaration shows that winds originating in Lemoore at 7 am, which is when the data in the record show elevated winds began, may have traveled to Corcoran, arriving around noon. However, Earthjustice states that because the Corcoran monitor began reading exceedances ofthe PM-10 standard at 6
a.m., EPA cannot claim the winds caused the Corcoran exceedance.

Response20:See our responses to comments 10 and 11.

Comment21:Earthjustice claims that the Figures 1, 2 and 3 inthe Null declaration show that the winds that did reach Corcoran proceeded northeast toward the Sierra foothills and did not

move in the direction ofBakersfield.

Response21:As discussed in our responseto comment 11 above,EPA assumed a more realistic threedimensional approach to using the HYSPLIT model than Earthjustice's twodimensional approach. We also used a small range ofstarting points for our HYSPLIT runs, recognizing that simply because the available Lemoore meteorological data were from a single point atthe Lemoore Naval Air Station, the data from thatpoint represent meteorological conditions over awider

area. See footnote 11 above.

Based on ourmore realistic inputs, we initiated three HYSPLIT runs, one

27There may have been some deposition and dispersion ofthe dust plume, as discussed in our proposal at 72 FR at49052, but enough material reihained suspended to impact the Bakersfield area. The fact that the 24-hour average PM-10 concentrations in Bakersfield and Oildale were 157 gg/m3 and 162 gg/m 3 compared to the 215 pg/m3
recorded atCorcoran certainly indicates that some deposition or dispersion occurred alongthe 55 mile pathway. starting halfway between Lemoore and Kettleman City (about 11 miles southwest from Lemoore), one at Lemoore, and one about 11 miles northeast ofLemoore. EPA chose these
two different starting locations outside ofLemoore because, based on the trajectory model, they more precisely depict the potential source regions for Corcoran, which is more east than south ofLemoore, and Bakersfield, which is

more south than east ofLemoore. Since the Lemoore station can be considered representative ofa larger area than Lemoore itself, the starting locations are considered part ofthe Lemoore area and dust was entrained from that entire area. Also, in support ofthat assumption, Hanford, which is about 15 miles east northeast ofLemoore, and Kettleman Hills, about 22 miles southwest of Lemoore, reported wind speeds above the threshold forthe entrainment of dust.

The results ofour HYSPLIT runs show that from Corcoran and eastward,

some ofthe dustmay have been transported more towards the Sierra foothills, but west ofCorcoran the dust

was transported southward towards Bakersfield. See Figures 1,2, and 3. These results are in general agreement with Jan Null's statement that:

* * * winds out ofKettleman City continued down the western-most side ofthe San Joaquin Valley, essentially following the contours ofthe Coastal Range. This is not unusualbehavior for winds on the west side ofthe Valley, which aregenerally faster than winds intherest ofthe Valley dueto the orientation ofthe Sacramento and San Joaquin Valleys.
Null declaration at 11. Between Lemoore and Kettleman City, the winds

were in transition from heading towards the east near Corcoran and following the Coastal Range as happened around Kettleman City. This caused thewinds in a portion ofthat transition area to go in a direct path towards Bakersfield. In
contrast to EPA's inputs to the HYSPLIT model, the inputs used by Jan Null did notreflect the wind flow structure in the Valley and did not demonstrate a comprehensive view ofthe meteorological events that took place during that day.

Comment22:Earthjustice believes that EPA was "dazzled" by theDistrict's

use ofthe HYSPLIT model even though the model is not an appropriate tool for posthoc simulation oflocalized meteorology and EPA did no analyses of its own. Earthjustice further states that the District's single run does not show the connection between Lemoore winds and the violating monitors that EPA apparently thinks it does. 

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Response22:See our response to comments 10, 11 and 21.

Comment23:Earthjustice maintains that the windsjust south ofLemoore, in and around Corcoran andbetween Corcoran and Bakersfield never exceeded the "alleged" threshold velocity to entrain dust and the winds originating in Lemoore that did exceed such threshold could nothave carried sufficient particles ofPM on to Bakersfield and Oildale. Earthjustice concludes therefore that the timing, wind trajectories and the basic physics ofwind movement do not support a causal connection between the Lemoore winds and the September 22, 2006 exceedances.

Response23:See responses to comments 11 and 16.

Comment24:Earthjustice notes that the District highlights a single data point showing sustained winds of 15.2 mph for one hour inAlpaugh. Earthjustice believes this is troubling because the District is relying on data from the California Irrigation Management Information System (CIMIS) monitoring network that the T &B Systems Report says should be

, used with "extreme caution." Earthjustice also believes that it is suspicious that the District puts forth data from this source while simultaneously providing almost none ofthe data it collects from its own meteorological sensors which are collocated with themonitors that record PM-10 concentrations.

Response24:Earthjustice quotes from the T &B Systems Report without providing the context ofthe warning to

use the data with "extreme caution." In its report, T &B Systems state:

CIMIS-This data set should be used with extreme caution.Two significant issues regarding the CIMIS data were noted. First, the fact that wind measurements are made at 2meters instead of10 meters appears to resultin thereported wind speeds decreasing by about 30 percent relative to those made at 10 meters. Thiscan becorrected, forthe most part,byusing the standard power law adjustment. Second, theresults brought about significant questions about the alignment ofthe wind direction system, with possible misalignments as much as300 noted. This potential problem was noted at,
a significant number ofsites investigated. The QAprogram for the CIMIS network is not known.
"T &B Systems Contribution to CRPAQS Initial'Data Analysis ofField Program Measurements, Final Report Contract 2002-06," Technical & Business Systems, Inc., November 9, 2004 at 3.

The issue ofthe height ofthe measurements taken at CIMIS', meteorological stations was addressed bythe State in its documentation.28 Winds measured at two meters above ground level (AGL) are generally lower than thosemeasured atthe standard 10 meters.

Regarding the alignment ofthe wind direction system, there were many other meteorological stations that provided data on wind direction and these showed that the winds were predominantly from the north and northwest on September 22, 2006.

Any uncertainty regarding the quality

assurance for the CIMIS data would carry more weight ifwe were relying solely onthe CIMIS data. Most ofthe meteorological data included in the State's documentation 29as well as the additional data obtained by EPA 30 and used to evaluate this exceptional event demonstration were from the District's meteorological stations and National -Weather Service meteorological networks. Since the District does not operate any monitoring stations between Corcoran and Bakersfield, it did not have any District-collected meteorological data for this region. Comment25:Earthjustice believes that the District did little more than a blind search for the areas ofthe SJV that experienced winds that exceeded the "alleged" entrainment level andthen concluded that pollution on September 22, 2006 must have originated from-that

area.

Response25:EPA believes that the State and EPA conducted a thorough evaluation ofthe possible cause ofthe September 22, 2006 exceedances and considered potential sources, conditions and control measures at the time ofthe exceedances. We discuss inadditional detail in ourresponse to comment 16 the fact that anumber oflocations inthe central SJV besides Lemoore experienced high winds on that day. After a consideration ofthe most likely

cause ofthe exceedances and after evaluating all the circumstances, the State concluded that the unusually high winds in the Lemoore area caused the exceedances in'Cotcoran and Bakersfield on September 22, 2006. The State then established inits documentation the causal connection between the winds inthe Lemoore area

28"Addendum, Natural Event Documentation, Corcoran, Oildale and Bakersfield, California, September 22, 2006," May 23, 2007 at 13.

29"Natural Event Documentation, Corcoran, Oildale and Bakersfield, California, September 22, 2006," San Joaquin Valley Unified Air Pollution Control District, April 20, 2007; "Addendum, Natural EventDocumentation, Corcoran, Oildale and Bakersfield, California, September 22, 2006,' ' San Joaquin Valley Unified Air Pollution Control District, May 23, 2007.

30Mes5owest historical meteorological data, Mesowest,http://www.met.utah.edu/mesowest/. and the exceedances atCorcoran and Bakersfield. Comment26:Earthjustice asserts that neither the District nor EPA offers any basis forthe statement in the proposed rule at 72 FR 49051 that "wind speeds [in Corcoran], though not sufficient to erode dust, were sufficient to keep entrained and transported dust from the .high winds at Lemoore suspended for the period during whichthe exceedances occurred." Earthjustice further asserts that because winds 10 miles southeast of Lemoore at the SRR

never exceeded the entrainment threshold and no other relevant location outside ofthe area northwest of Lemoore experienced erosive winds, there is very little basisf6rthe conclusion that a clear causal relationship exists between dust entrained in Lemoore and violations of the standard in Corcoran, Oildale and Bakersfield.

Response26:See responses to comments 10, 11, 15 and 16. Comment27:Earthjustice asserts that EPA fails to show that the exceedances
at Corcoran, Bakersfield and Oildale

were outside normal historical concentrations. Earthjustice claims that dust-intensive agricultural .activities

occur inthe fall andthat none ofthe September 22, 2006 exceedances are significantly beyond the normal fluctuating range of air quality concentrations inthe SJV. Earthjustice presents a chartthat it says demonstrates that the September 22, 2006 readings are within the historical range ofPM-10 concentrations observed

over the past 15 years during the fall

season.

Response27:See our response to comment 12 above.

Comment28:Earthjustice states that EPA suggests in the Exceptional Events Rule that a contemporary comparison of all seasonally-adjusted data is appropriate for determining historical frequency ofthe measurements in question. However, Earthjustice says, because fall is the season with the highestPM-10 concentrations, the comparison is most appropriately made by looking athistorical data from September through November. Earthjustice claims that because the District's documentation limits its comparison to September measurements

over a 7 year period, the result is a "typical value" based only on the "relatively good days monitored."

Response28:See our response to comment 12 above.

Comment 29:Earthjustice maintains that EPA asserts thatbecause the September 22, 2006 measurements were higher than what the District claims is

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the "typical value" for the month of September, these violations must have beencaused by an exceptional event. Earthjustice claims that withthis argument EPA is saying that any PM-10 exceedance should be ignored as exceptional which is an absurd assumption that would render the NAAQS meaningless.

Response29:EPA did notdecide to exclude the data from September 22, 

### 2006 from its attainment finding simply because the data were outside ofthe typical range ofvalues normally seen in these areas. The EER has a number of criteria that need to be met in order for

us to concur with a State's request to exclude data from consideration, including a demonstration that the event affected air quality, a causal 

### connection between the event andthe exceedance value recorded, an analysis demonstrating that therecorded exceedance was outside the normal fluctuation ofthe data, and a demonstration that "but for" the event the exceedance would nothave occurred. EPA evaluates how the State
meets all of these criteria, in addition to the procedural requirements ofthe EER and determines, based on the weight of the totality ofthe evidence presented, whether to concur with the State's 

### request. In thiscase, EPA believes that the State has met the "weight-ofevidence" standard and has demonstrated that the cause ofthe exceedances on September 22, 2006 was

a high wind exceptional event. See also

our response to comment 12.

Comment30:Earthjustice states that if 

### EPA had compared the September 22, 2006 data to data from other days on which exceedances occurred, it would have found that the September 22, 2006 readings are typical ofbad air days in the fall in the SJV and therefore would not have been able to dismiss these violations as 'Vinexcess ofnormal fluctuations."

Response30:See response to comment 12.

Comment31:Earthjustice states that it 

### reviewed EPA's AQS reports of monitoring data fromthe past tenyears and found that in Corcoran, 50 percent ofall FRM readings showing elevated levels ofPM-IO occur in September and October and that 95 percent occurin the period from September to January. Earthjustice states that although the numbers are lower in Bakersfield and Oildale, with 31 percent and 29 percent ofelevated PM-10 readings, respectively, occurring in September and October, these numbers do not paint the picture ofexceptionality the District and EPA claim. Instead, Earthjustice declares, these numbers confirm that the concentrations recorded on September 22, 2006 were within the normal historical range of PM-10 concentrations experienced in the central and southern SJV duringthe fall PM season when concentrations are historically at theirhighest.

Response31:As discussed in our response to comment 12, EPA analyzed data from these sites and determined that the concentrations recorded on September 22 and October 25, 2006

were well outside the normal historical fluctuation ofdata normally recorded at these sites. In its comment, Earthjustice analyzes what it states are "elevated levels" ofPM-l0 concentrations that
,wererecorded at the Corcoran, Oildale, and Bakersfield-Golden State Highway sites. Earthjustice asserts that an "elevated level" is "defined by EPA" as 90 gig/m3 or greater.31This is notthe

-case. For the source ofits definition, Earthjustice cites a Federal Register notice inwhich EPA proposed to approve a PM-10 maintenance plan for Wallula, Washington. Inthat proposed rule the 90 gg/m3 orgreater was a figure employed by the Washington State Department ofEcology for use in modeling aPM-10 maintenance demonstration. 70 FR 38076 (July 1, 2005). EPA did not endorse or adopt this level as a definition ofwhat constitutes "elevated levels" ofPM-la for the purposes ofperforming an analysis ofhistorical fluctuations for the EER, and Earthjustice's evaluation of 

### "elevated levels" atthe SJVmonitoring sites is notbased on an EPA definition ofwhat constitutes "elevated levels" for this purpose. Comment32:Earthjustice claims that the "but for" test requires ashowing that without the winds scouring the soils near Lemoore, the monitors in Corcoran, Bakersfield, and Oildale would not have recorded violations of the PM-10 standard and that such a showing cannot be made. Specifically, Earthjustice asserts that the monitor in Corcoran was violating the PM-la standard on September 22, 2006 before the winds in Lemoore even picked up. Earthjustice states that Table 3 ofthe District's April 20, 2007 documentation shows that the continuous monitor in Corcoran was recording concentrations in excess of 150 gg/m3 starting at 6 a.m. Earthjustice further maintains that Jan Null inhis declaration states that there is no way the winds in Lemoore could transport entrained dust instantaneously from Lemoore to Corcoran.

Response32:We address these issues in our responses to comments 10, 11, 16 and 21. In our proposed rule we also

31EC at6, footnote 16. discussed how the State met the "but for" criteria. 72 FR at 49053.

-Comment33:Earthjustice further asserts that the winds InCorcoran never
even got above 11 miles per hour, so local wind entrainment of particulate matter is not a factor. Earthjustice concludes that activities in and around Corcoran must have been responsible forthe high PM-la concentrations on September 22, 2006, notwinds from Lemoore.

Response33:We addressed the lower wind speed issue inCorcoran in our proposed rule at 72 FR49052 and also in our responses to comments 10 and 15. As we discussed inthe proposed rule, the lower wind speeds inCorcoran do notpreclude the transport ofdust from the areas northwest ofCorcoran. The wind data from September 22, 2006 show high winds in the area centered around Lemoore. It was this area northwest ofCorcoran that contributed PM-10 to the air parcel that impacted the monitors at Corcoran and Bakersfield. While any sources in the local area represented by the Corcoran monitor may have contributed some PM-10 to the total 24-hour average, it

was the wind-generated dust from the

area ofLemoore that contributed enough PM-10 to cause the monitor to record an exceedance ofthe 24-hour PM-la NAAQS.

Given the evaluation ofall information and circumstances surrounding the exceedance at the Corcoran monitor on September 22, 2006, the weight ofevidence supports the conclusion that the windblown dust from the area of Lemoorerather than contributions from sources in the area represented by the Corcoran PM-la monitor were the "but for" cause ofthe exceedance.

Comment34:Earthjustice argues that,

even if6 hours worth ofreadings from the Corcoran continuous monitor were removed starting at 11 a.m., in order to account for the 6 hours during which winds inLemoore exceeded the alleged threshold velocity, there is still a violation ofthePM-10 standard. Therefore, Earthjustice concludes, there is no way the District can argue and EPA can concur that winds from Lemoore were the cause ofthe violation ofthe PM-la standard in Corcoran on September 22, 2006.

. Response34:As discussed inthe preamble to the EER, EPA's historical practice hasbeen to exclude a daily measured value in its entirety when an exceptional event causes that value. See 72 FR at 13572. EPAis not aware ofthe existence ofprecise and universally applicable techniques that are administratively and technically 

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feasible and that could support partial adjustment ofair quality data. Thus, the approach suggested by Earthjustice is
not viable and is'not permitted bythe

- EER except in some very limited cases not applicable here. See also response to comments 10.

Moreover, Earthjustice suggests that the winds from Lemoore began affecting the Corcoran monitor at 11 a.m. In fact the Lemoore area experienced winds higher than the threshold wind speed beginning at6 a.m. PST and these winds likely began affecting the monitor at Corcoran between 7 and 8 a.m. PST (the value reported for 7 a.m. PST). See response to comment 10. When the winds at Lemoore decreased to levels below the threshold wind speed at 2 p.m.PST, the dust entrained inthe atmosphere most likely still continued
to impact the Corcoran monitor, though

we see a leveling offand then gradual decrease inhourly PM-10 concentrations from that point forward. See Table 3 above in our response to
comment 10. We further addressed this timing questionby performing our own HYSPLIT analyses. See response to comment 11 above. The result ofour analysis ofthe winds on September 22 supports the State's demonstration that winds originating inthe area around Lemoore starting at6 a.m. PST could have transported dust and impacted the Corcoran monitor within one to two hours. See Figures 1 and 2.

Earthjustice appears to assume that particles are deposited as soon as winds decrease below the threshold speed for entrainment; in fact, PM-10 particles remain in suspension formany hours afterbeing entrained and, as in the case ofCorcoran, continued to affect concentrations recorded atthe monitor until the early evening hours of September 22, 2006. Thus, Earthjustice

assumes that the windblown dust started to affect the concentrations monitored at Corcoran many hours later than it did in fact, and that it ceased to impact the monitormany hours before it did in fact. Thus EPA believes that the impact onthe monitor started earlier and ended later than Earthjustice contends, and was thus the "but for"

cause ofthe exceedance.

Comment35:Earthjustice maintains that there is no support for the claim that but for thewinds originating in Lemoore, the monitors inBakersfield and Oildale would not have exceeded the PM-10 standard. Earthjustice states that Jan Null shows inFigures 1, 2 and 3 inhis declaration that the winds originating in Lemoore may have reached Corcoran at some point in the day, but they certainly did not continue

onto Bakersfield and Oildale. Earthjustice states that the trajectories of winds out ofLemoore and Corcoran

were decidedly away from Bakersfield and could not have carried particulate
matter to Bakersfield and Oildale to

cause the violations ofthe standard seen inthese locations. Earthjustice states. that Figure 4 in Jan Null's declaration shows that,in fact, any winds arriving inBakersfield by 1p.m. were slow and moving ina circular pattern up from the southwest. Further, Earthjustice asserts that, as illustrated in Table A-1 ofthe District's MayAddendum to its April 20, 2007 documentation, wind speeds in the Bakersfield area never reached speeds capable oferoding soils.

Response 35:We havepreviously addressed the-issueof dusttransport to Bakersfield in our responses to comments 10, 11, 15, 16 and 21. EPA does not contend that the wind speeds in Bakersfield reached the speeds necessary to erode and entrain dust,but rather that windblown dust from the

area beginning in Lemoore and moving south affected the monitors in Bakersfield.

The trajectory calculation that Jan Null used for Bakersfield was not illustrative ofthe complete meteorological scenario. Again, he used

a single trajectory calculation starting at

zero meters height which doesnot account for the third dimension of height ofthe dust above ground level. In HYSPLIT runs performed by EPA, forward trajectory calculations within the mixed layer starting between Lemoore and Kettleman Hills show transport directly to Bakersfield within 7hours.

In addition, the circular wind pattern

or eddy near Bakersfield discussed by Earthjustice was produced by a HYSPLIT analysisusing a backward trajectory. However there appears to be

a discrepancy between forward trajectories andbackward trajectories produced by the HYSPLIT model. In source-receptor determinations, forward trajectories are considered more appropriate in determining precise locations ofsources because they more accurately account forwhere the weather is coming from.EPA's forward trajectories did not show any indication ofan eddy. The eddies that Earthjustice
states occurred-around Bakersfield are around 15kin in size for September 22, 2006. Since the EDAS meteorological data used for the trajectories has 40 km spacingbetween each grid point or meteorological data point, it is notof high enough resolution to accurately represent an eddy-in the 15 km size
range. There is too much uncertainty to conclude that there is an eddy because it is less than one grid cell spacing in dimension and wouldbe considered a sub-grid scale feature. Thus, EPA's HYSPLIT runs, usingmore appropriate height levels in the atmosphere and forward trajectories, support the conclusion that the winds transported dust from the Lemoore area and caused the exceedances recorded at the monitors inthe timeframe ofthe exceedances.

Comment36:Earthjustice argues.that, in evaluating the "but for" demonstration, no attempt was made to determine which of the many diverse

sources that contribute toparticulate
matter concentrations inthe SJV might havebeen contributing to thepollution load and inwhat quantities on September 22, 2006. Earthjustice concludes that for EPA to declare that

no "unusual activities" were taking place onthis day is to saythat the same dust-generating sources that have always caused periodic violations ofthe standards in the fall were again responsible for exceedances.

Response36:See responses to comments 6, 12 and 14.

3. Comments Specific to October 25, 2006-Corcoran and Bakersfield

Comment 37:Earthjustice states that the documentation forthe exceedances

on October 25, 2006 is remarkably similar tothat of September 22, 2006, and as such, suffers from the same significant flaws. Earthjustice also states that since the meteorology for both days

was Very similar, much ofits analysis for September 22, 2006 also applies to October 25, 2006. Earthjustice provides

a chart which it contends shows that wind speeds in Lemoore on October 25

were very similar to wind speeds on September 22. Withrespect tothis chart, Earthjustice asserts the following:

* * * therewas aperiod ofseveral hours during which the alleged wind speed threshold was exceeded in northwest Lemoore at the Naval Air Station monitor, though again wind speeds at the Santa Rosa Rancheria monitoronly 10 milessoutheast

never reached that threshold. * * *Winds in Corcoran never got above 11.3 miles per hour andBakersfield, likewise, did not exceedthe District's alleged entrainment threshold with maximum windsjust under seven miles per hour. * * *Further, the Districtcan pointto

no databetween Lemoore and Bakersfield that show winds capable ofentraining dust, offering instead only data from CIMIS stations located far to thenorth andwestthat experienced higherwind speeds on October 25, 2006. Ashas alreadybeen established by Mr. Null,higher wind speeds on the west side ofthe Valley along theCoastal Range are not unusual due to the orientation ofthe Sacramento and SanJoaquin Valleys. * * *

Response37:To the extent there are similarities between Earthjustice's

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analyses for September 22 and October 25, 2006, EPA's responses to comments regarding September 22 are also applicable.

In addition,EPA notes that the wind speeds inthe central SJV, as represented by themeteorological monitoring station
at Lemoore, on October 25 werequite high, reaching hourly average speeds of 31 mph and gusts ofup to 40 mph, and

were sustained at levels above the threshold wind speed for 11 hours (5 a.m.to 3p.m. PST),32 as shown in Table 5 above. We do not contend that the wind speeds in the vicinity of Corcoran and Bakersfield Were
, sufficient to entrain dust but, like September 22, 2006, the windblown dustgenerated inthe Lemoore areain the central SJVwas the "but for" cause ofthe exceedances recorded in Corcoran and Bakersfield on October 25, 2006. Moreover, the wind speeds that occurred inbetween Lemoore and Corcoran and Bakersfield were of sufficient speed to transportthe entrained dust from Lemooreto the affected areas. Id.

Earthjustice again selectively presents meteorological data to support its own 

### position and neglects to include other data that support the State's demonstration. From the data sipplied bythe State in its documentation as well as additional publicly available data,itis clear that wind speeds in Lemoore, aswell as throughout the central San Joaquin Valley, were either in excess ofthe threshold wind speed for entrainment (18 mph) or ofsufficient intensity totransport dust from the Lemoore areato Corcoran and the southern SJV. See Table 7below.

TABLE 7.-OCTOBER 25, 

### 2006 DAYTIME WIND SPEEDS AT METEOROLOGICAL MONITORING STATIONS IN THE CENTRAL SAN JOAQUIN VALLEY

Mendota Tranquility Lemoore Hanford Ketelan Alpauh Wasco HorAirport Hills (or) (hour/dir/ (hour/gust) (hour/gust) (hour/gust) (hour/gust) (hour/gust) our gust)

6

.............................................................. 12/ND 9/15 22/30 17/23 11/21 3.5 2/SW /3 7

............................................................... 15/20 10/17 22/32 15/ND 20/28 2.9 0 8

............................................................... 18/25 13/19 26/36 17/ND 15/27 5.6 7/NNW/15 9

.. ............ 17/30 20/22 29/39 24/29 19/32 16.9 5/NNE/18 10

.... ............................. 22/31 17/21 31/37 20/28 25/35 16.5 9/N/22 11

.... ............................. 22/30 15/20 30/40 15/24 25/35 16.8 71N/i5 12

.... ............................. 21/28 17/20 28/38 12/21 24/45 15.6 6/N/16 13

.... ............................. 20/28 15/23 26/35 12/ND 25/34 14.8 8/N/i6 14

............................................................. 18/29 18/19 22/31 9/ND 21/35 13.2 2iNNE/10 1"5

............................................................. 12/23 10/18 20/26 12/18 22/33 13.3 ND/N/12 16

............................................................. 15/20 8/17 14/ND 8/16 15/28 12.7 3/N/7 17

............................................................. 8/17 4/10 3/ND 8/ND 9/22 6.5 2/N/ND 18

............................................................. 5/6 1/5 6/ND 6/ND 10/14 4.4 0

Source: Mesowest historical meteorological data, Mesowest, http://www.met.utah.edu/mesowest. ND-No Data available.



### South ofCorcoran, wind speeds measured at Alpaugh,33 15 miles SSE of Corcoran and 44 miles NW of Bakersfield, were close to exceeding the threshold wind speed and as such were sufficient to transport particulate matter from the Lemoore area to Bakersfield as discussed above andin our proposed action.Furthermore, meteorological data from a station in Wasco, 40 miles SSE ofCorcoran and 25 miles NW of Bakersfield andnot part of theCIMIS network, recorded data that indicate that the daytime winds, while not high enough to erode soils, were predominantly from the north. Comment38:Earthjustice states that like the documentation for September 22, 2006, theDistrict's documentation forthe alleged October event also fails to analyze the actual ability ofthe area to generate particulate matter concentrations inquantities great enough to cause the exceedances, fails to provide anythingmore than anecdotal evidence ofactivity levels and compliance with dust controls, and

32Asdiscussed inresponseto comment 10 above, the meteorological data for Lemoore mustbe adjustedto correct forDaylight Savings Time. 

### therefore fails to demonstrate that the winds inLemoore affected air quality at all. Earthjustice states that,like the case for the September 22 demonstration, a claim that the wind entrained significant amounts ofdust requires looking atmore thanjust the wind speeds in thearea. There are many factors that EPA andthe District failed to support with any reliable and accurate data, starting with whether there was any dust available tobe entrained.

Response 38:See responses to comments 6, 14 and 18. As is the case with the September 22, 2006 

### documentation, the State has evaluated

a variety offactors and circumstances to demonstrate that windblown dust caused the exceedances onOctober 25. See "Natural EventDocumentation, Corcoran andBakersfield, California, October 25, 2006," San Joaquin Valley 

### Unified AirPollution Control District, April 23, 2007 at section 7.



### The State also provided information

on the inspection and compliance

3 3 See response to comment 24. 

### activities that were conducted on October 25, 2006. Section 9.2 ofthe 

### State's documentation lists the number ofinspections andthe location of inspection activity and indicates that the District was actively enforcing its rules on October 25, 2006. Two 

### newspaper accounts ofthe high winds that occurred on October 25, 2006 

### provide independent verification of meteorological conditions, Thistype of documentation has beenhistorically used to support these types of exceptional events requests. EPA's EER states thatthe simplest demonstrations could consist ofnewspaper accounts or satellite images to demonstrate that an event occurred together with daily and seasonal average ambientconcentrations to demonstrate an unusually high ambient concentration level, whichis clearly indicative ofan exceptional impact. 72 FR at 13573.



### Comment39:Earthjustice states that,

as explained in its comments for September 22, 2006, the generation of 

### particulate matter from winds ofthe 10 1 I I I I I ! II I I I I I I • I I II • I Il l II I | II I I I 114709f

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type experienced on October 25, 2006 could have been controlled or prevented had reasonable controls been required of dust-producing sources. Earthjustice believes that the fact that the District is trying to blame winds only slightly abovethe alleged wind speed threshold, and significantly below the velocities at which the aforementioned controls stop being effective, suggests that either winds could not have entrained dust or the reasonable measures referenced in the proposal werenot actually in place at the time ofthe event.

Response39:See responses to comments 5, 6 and 7. The winds inthe Lemoore area on October 25 were not "slightly above" the wind speed threshold but rather included sustained high winds between 26 and 31 mph with gusts ranging from 26 to 40 mph. These wind speeds were clearly sufficient to entrain and transport PM10.

Comment40:Earthjustice states that high winds entraining dust may qualify

as a natural event, but it also believes the source ofthe dust is ofequal importance under the law. Earthjustice states that EPA admits that on October 25, 2006, the wind-entrained particulate matter originated from anthropogenic

sources such as agricultural and industrial activities, but that under the EER, only "an event inwhich human activity plays little or no direct causal role" can be considered anatural event. Earthjustice states that Congress did not intend for exceptional events to include

sources that are caused by human activity. Alternatively, Earthjustice states that the source ofthe dust cannot be considered a non-recurring human activity, as agricultural and industrial activities are a constant source of emissions inthe Valley.

Response40: See response to comment 5. Also, regarding Earthjustice's argument that dust from agricultural and industrial activities cannot be considered anon-recurring human activity because these activities

are a constant source ofemissions in the Valley, EPA does not consider (andhas not stated anywhere) that normal agricultural and industrial activities are "non-recurring human activity" because such human activities often recur on a regular basis. By contrast, examples of non-recurring human activities may include major construction projects such as highways ifthey meet the criteria and requirements established in the EER. However, a recurring natural event such as a high wind event may entrain dust from anthropogenic

sources. The entrainment ofdust from "reasonably controlled sources" such as agricultural sources does notconvert a natural event that qualifies as ahigh wind event into a recurring human activity which appears to be the result Earthjustice is seeking.

Comment 41:Earthjustice states that, like the September 22, 2006 documentation, the District did not provide the requisite amount oftime for public comment on its October 25, 2006 documentation and did not re-publish its final documentation after radically changing its rationale. These procedural deficiencies alone should give EPA pause in considering the District's requests to flag this data.

-Response41: See response to comment 8.

Comment 42:Earthjustice states that since the meteorology on October 25, 2006 is so similar to that ofSeptember 22, 2006, it is not surprising that a causal connection cannot be established for October 25 either. Earthjustice points out that the Corcoran monitor began reading concentrations above the national standard at 6:00 am, the same time that the winds in Lemoore, 25 miles away, began exceeding the District's alleged wind speed threshold at the same time. Earthjustice believes that it should gowithout saying that it is notpossible for winds in Lemoore to transport entrained dustto Corcoran instantaneously, which is what would have tobe the case ifwe are to believe the District's claims that those winds caused the exceedances inCorcoran, and that therefore, something other than the Lemoore winds caused the initial exceedances recorded at that monitor.

Response42: See responses to comments 10 and 11.

Comment43:Earthjustice states that

even ifwe were to assumethat the winds carried dust from Lemoore to Corcoran, the trajectory ofthose winds does not support the conclusion that the dustthen moved down to Bakersfield. Earthjustice cites Figure 7 inthe Null declaration which shows that winds originating in Lemoore moved on adueeast path toward Hanford and Corcoran and continued ontoward the Sierra foothills. Jan Null uses HYSPLIT to determine the source ofwind parcels arriving inBakersfield at noon, which is approximately whenthe exceedances began, and shows that the same slow eddy effect that occurred on September 22, 2006 was also occurring in Bakersfield on October 25, 2006, which

means that the winds impacting Bakersfield during the time ofthe exceedances were coming in slowly from the southwest. Figure 8 inthe Null declaration.

Response43:As discussed in our responses to comments 11 and 21 above, EPA assumed amore realistic three dimensional approach to using the HYSPLIT model than didJan Null.We also used a small range ofstarting points for our HYSPLIT runs, recognizing that although the available Lemoore meteorological data were from apoint located at the Lemoore Naval Air Station, the data represent conditions

overa wider area. See footnote 11 above.

As with our analysis ofthe September 22, 2006 event, we initiated three HYSPLIT runs for October 25, 2006, one-, starting halfway between Lemoore and Kettleman City (about 11 miles southwest from Lemoore), one at Lemoore, and one about 11 miles northeast ofLemoore. On October 25, 2006, the HYSPLIT trajectory presented by Null in Figure 7of his declaration indicates that the winds starting in Lemoore went to the east southeast. However, EPA's HYSPLIT runs initiated halfway between Lemoore and Kettleman City, northwest ofCorcoran, demonstrate that the winds continued downthe SJV towards Bakersfield, along apath just west ofCorcoran. See Figures 5 and 6 above. Between Lemoore and Kettleman City,the winds

were in transition from heading towards the east near Corcoran and following the Coastal Range as happened around Kettleman City. This caused the winds in a portion of that transition areato go ina direct path towards Bakersfield. See Figure 5.

For Bakersfield, Null used a trajectory inFigure 8 ofhis declaration atzero meters heightto show the same eddy effect occurring on October 25 as on September 22. Again, this height does not take into account dust mixing up into the atmosphere. In EPA's HYSPLIT
runs, more appropriate forward trajectories were used which showed that dustcoming from the Lemoore area could have reached Bakersfield within about 6 hours. See Figure 6. They also didnot show any indication ofthe eddy effect near Bakersfield that Earthjustice found with back trajectories. Id.and response to comment 35. This supports the conclusion that dust-laden winds from the Lemoore area reached Bakersfield on October 25, 2006 consistent with the impacts reflected at the Bakersfield monitor.

Comment44:Earthjustice states that while the District and EPA cite wind speeds averaging 12 miles perhour in Alpaugh, an area 15 miles south of Corcoran, neither agency provides a basis for concluding that such winds could transport and keep suspended the plume ofentrained dust that was allegedly carried to Bakersfield, nor do they explain howthe evidence provided

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even suggests such transport could have taken place.

Response44:See responses to comments 11, 15 and 43. EPA finds that the documentation does establish a clear causal relationship between the winds in Lemoore and the exceedances in Corcoran and Bakersfield. See "Natural Event Documentation, Corcoran and Bakersfield, California, October 25, 2006," San Joaquin Valley UnifiedAir Pollution Control District, April 23, 2007. Earthjustice neglects to consider that the CIMIS data need to be adjusted,

as discussed in the State's documentation, due to the fact that CIMIS stations collect data at2 meters above ground level as opposed to the standard 10meter height. Id.at 25. See also response to comment 24. When this adjustment is made, we can see that the wind speeds atAlpaugh would have been approximately 25 percent higher at 10 meters than at 2 meters. Winds at nearly 17 mph wererecorded from 9

a.m.to 11 a.m. PST, dropping to between 15 mph and 13 mph between 12 p.m. and 3 p.m. PST. The lower wind speeds recorded at stations farther south, such as Shafter and Arvin, are consistent withthe State's demonstration that after the winds in the central SJV transported particulate matter southward, lower wind speeds in the Bakersfield area facilitated the settling ofthe particulates atthe monitoring station.

Comment 45:Earthjustice states that while the readings from October 25, 2006 were relatively high,they were probably not beyond the normal historical fluctuations experienced in the Valley inlate October. Earthjustice also states that fall is when the Valley's PM-10 concentrations are at their highest and also the peak season for many dusty crops in the Valley.

Response45:See our responses to comment 7and 12 above, Comment46:Earthjustice states that EPA's "but for" analysis forthe October 25, 2006 event isbased entirely on speculation and conjecture and that EPA cannot say for sure what activities

were taking place in the areas of Corcoran or Bakersfield and cannot say for sure that without the alleged high winds inLemoore the monitors in Corcoran and Bakersfield would not have exceeded the standard.

Response 46:See responses to comments 6 and 7 and EPA's "but for" analysis in our proposed rule at 72 FR 49056-49057. EPA's conclusion is not based on speculation and conjecture but rather onthe weight ofevidence presented.

Comment47:Earthjustice states that since the HYSPLIT analyses provided 

### both bythe District andby meteorologistJan Null contradict the claimthat the winds from Lemoore had

a sufficient speed oi trajectory toimpact Corcoran andBakersfield, and because the Corcoran andBakersfield monitors

were already measuring exceedances of the PM-10 standard before thewinds fromLemoore could have arrived, EPA cannotconclude that theDistrict has established that "but for" the winds in Lemoore, the exceedances would not have occurred.

Response47: See responses to comments 10, 11, 21, 43 and 44.

B. OtherComments



### Comment48:A commenter notes that the concept ofexceptional events for air qualitypurposes is "a bad idea" because they provide a loophole to gutthe intent ofthe original regulation. The commenter expresses concern that discarding data related to exceptional events would substantially weaken the regulation designed to protect the health ofresidents inan area. Inthe particular instance ofthe SJV, the commenter notes thatthe exceptional events were highwinds and construction activity. According tothe commenter, these events should notbe usedtojustify por air qualitybecause high winds are a natural occurrence and construction activity occurs repeatedly. The commenter expresses concern that exceptional events notbe used as "additional excuses to rationalize bad air on certain days."

Response48:Congress amended section 319 ofthe CAA and required 

### EPA to establishregulations governing the review andhandling ofairquality monitoring datainfluenced by exceptional events. In amending section 319, Congress indicated that states should not have to prepare and implement regulatory strategies designed to remedy poor airquality when their airquality is affectedby events beyond theirreasonable control. To accomplish thisgoal, Section 319, as amended, defined an exceptional event andrequired EPAto setcertain minimum substantive andprocedural requirements before data could be excluded as due to an exceptional event.. Inresponse, as describedbelow, EPA proposed regulations forexceptional events in March 2006 and sought public comments onits proposal. See 71 FR 12592 (March, 10, 2006). InMarch 2007, 

### after considering allcomments received, EPA published its finalrule on exceptional events whichbecame effective on May 21, 2007. 72 FR 13560. 

### During the exceptional events rulemaking process, EPA took comments onthe definition of exceptional events, the substantive and procedural requirements foran event tO qualify as an exceptional event and appropriate mitigation measures in these circumstances. Inthis rulemaking

onairquality inthe SJV, EPAis neither seeking nor considering comments on the concept ofexceptional events, which activities would constitute exceptional events, and/or whether air quality data may beexcluded dueto such events. EPA has already addressed these issues in its EER. Comments about the concept ofexceptional eventsand whether such events should be considered in airquality determinations have been decided inthe exceptional events rulemaking process and thusare outsidethe scope ofthisrulemaking.

The commenter also notes that as a general matter highwinds shouldnot be considered an exceptional event because they are natural occurrences. EPA has discussed highwind events extensively inthe preambles toboththe proposed and the finalrules on exceptional events. The EER indicates the circumstances under which high winds can qualify fortreatment as exceptional events. Again, these general issues were decided in the EER andEPA did notreopen comment onthat general issue inthis SJV rulemaking. The commenter does notprovide data relevant to whether the highwinds in thisinstance meet the provisions ofthe EER, the issue under consideration in this rulemaking action.

The commenter asserts that "construction is always occurring" and therefore datarelated tothese events should notbe excluded. Not all construction activity qualifies asan exceptional event. A construction activity, likeother exceptional events mustmeet the definitional, substantive andprocedural requirements specified intheEER. For example, forany construction activity to be considered

an exceptional event, itmustmeet the definition ofan exceptional event, including for anthropogenic events such

asconstruction, that itis an event that is unlikely torecur at that location. Thus, by definition, construction activity that is "always occurring" at a particular location isnot an exceptional event under therule.

Comment49:The commenter states thathe isunfamiliar with details ofthe SJV casebutwishes to comment onthe concept ofexceptional events and expressed hisview that such events should notbe considered in air quality determinations. The commenter believes that there are awide variety of loopholes such aspermitting rounding down ofnumbers, exclusion ofthree worstdays andusing three year 14711

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averages forfinal attainment which "degrade the rigor ofthe standard." According to the commenter, excluding air quality data affected by exceptional
events further softens the initial regulation. Inthe SJV case, the
commenter questions why the construction activity was not limitedto periods when the atmosphere could "handle the load." In addition,the
commenter discusses the construction of an asphalt plant in alocal community and notes that during the construction ofsuch a plant, officials sought to exclude data on certain days because they attributed the poor air quality to interstate transport. The commenter also refers to the treatment offires inhis

area.

Response49: With respect to that portion ofthe comment concerning the concept ofexceptional events, see response to comment .48.In response to the commenter's question about why the construction activity was not limited to periods whenthe atmosphere could harndle the load, EPA notes that air quality "load" is not an issue for the SRR area where construction contributed to the exceptional event. Thiere have been no exqeedances or air quality issues inthe SRR area either before or afterthe construction activity. As explained in the proposed rule, the monitor inthe SRR was affected bythe construction activity because it was in such close proximity to the construction activity (25-100feet). 72 FR at49062. The monitor hasnot recorded any exceedances since the construction activity atthe parking lot was completed. The comments on the construction ofthe asphalt plant and the fires do notrelate to issues in the SJV

area and thus are outside the scope of thisrulemaking.
C.ListofEPA Figures in Docket 

### * Figure 1. "Forward Trajectories at 10, 100, &250 meters, Lemoore Area to Corcoran, September 22, 2006, 6 a.m.to 8 a.m. PST," March 6, 2008.

* Figure 2. "Forward Trajectories at 250meters, Lemoore to Corcoran and Bakersfield, September 22, 2006, 6 a.m. to 1p.m.PST," March 6, 2008. * Figurq 3. "Forward Trajectories at 10, 100, & 250meters, Lemoore Area to Bakersfield, September 22,-2006, 6 a.m. to 1p.m. PST," March 6, 2008.

o Figure 4. "Forward Trajectories at 10, 100, & 250meters, Lemoore Area to Corcoran, October 25, 2006, 5 a.m. to 7

a.m.PST," March 6, 2008.

* Figure 5. "Forward Trajectories at 250 meters, Lemoore to Corcoran to Bakersfield, October 25, 2006, 5 a.m.to 11 a.m. PST," March 6, 2008.. a Figure 6. "Forward Trajectories at 10, 100, & 250 meters, Lemoore Area to Bakersfield, October 25, 2006, 5 a.m. to 11 a.m. PST," March 6, 2008.

a Figure 7. "Annual Peak Day PM10 Concentrations atCorcoran," March 6, 2008.



### * Figure 8. "Annual Peak Day PM10 Concentrations atBakersfield," March 6, 2008.

• Figure 9. "Annual Peak Day PM10 Concentrations at Oildale," March 6, 2008.



### * Figure 10. "Annual Peak Fall Day PM10 Concentrations atCorcoran (September, October, November Data Only)," March 6, 2008.

. Figure 11. "Annual PeakFall Day PM10 Concentrations at Bakersfield (September, October, November Data Only)," March 6, 2008.

• Figure 12. "Annual PeakFall Day PMIO Concentrations at Oildale (September, October, November Data Only)," March 6, 2008.

IH.Final.Action

For the reasons set forth in detail in EPA's proposed rule and in today's final rule, including ihe responses to comments, EPA is concurring with the State's and the Santa Rosa Rancheria Tribe's requests to flag exceedances occurring in 2006 asbeing causedby exceptional events. (i.e., highwinds and construction activity invery close proximity to the monitor, respectively). In addition, as set forth in its proposed rule, EPA is finding that the monitor at the Santa Rosa Rancheria was not properly sited for purposes ofcollecting data for comparison to the NAAQS during the period that exceedances were monitored in 2006. EPA is thus concluding that the exceedances that are the subject ofthese requests should be excluded from use in determining whether the SJV has attained the PM10 NAAQS. EPA is finalizing its proposal to affirm the determination of attainment forthe SJV,based on qualityassured data through December, 2006.34

For the reasons set forth in its proposed rule and inthis final rule, EPA is denying the December 29, 2006 petition forreconsideration and the March 21, 2007 petition forwithdrawal ofEPA's 2006 determination of attainment filedby Earthjustice on behalfofthe Sierra Club,Latino Issues Forum, and others.

34The District has flagged exceedances occurring

on July4, 2007 andJanuary 4, 2008 as being caused by exceptional events. We intend to address these exceedances in the future. IV. Statutoryand Executive Order Reviews

Under Executive Order 12866 (58 FR 51735, October 4, 1993), this action is not a "significant regulatory action" and therefore is not subject to review by the Office ofManagement andBudget. For this reason, this action is also not subject toExecutive Order 13211, "Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use" (66 FR28355, May 22, 2001). This action merely makes a determination based on air quality data, and imposes no additional requirements. Accordingly, the Administrator certifies that this rule will not have a significant economic impact on a substantial number ofsihall entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.). Because this rule does not impose any additional enforceable duty, it does not contain any unfunded mandate or significantly

oruniquely affect small governments, as described inthe Unfunded Mandates Reform Act of 1995 (Pub.L. 104-4).

Executive Order 13175 (65 FR 67249, November 9, 2000) requires EPA to develop an accountable process to

ensure "meaningful and timely input by tribal officials in the development of regulatory policies that have tribal implications." As discussed in our proposed rule, several Indian tribes have reservations located within the boundaries ofthe SJV. EPA is aware of only one tribe inthe SJVthat operates

a PM-10 monitor, the Santa Rosa Rancheria. Prior to and since the proposed rule, EPA has consulted with representatives ofthe Santa Rosa Rancheria Tribe on the data recorded by its monitor, and the flagging of the data, and will continue to work with the Tribe, asprovided forin Executive Order 13175. Accordingly, EPA has addressed Executive Order 13175 tothe
extent that it applies to this action. This action also does not have Federalism implications because itdoes not have substantial direct effects on the States,

onthe relationship between the national government and the States, or on the distribution ofpower and responsibilities among the various levels ofgovernment, as specified in Executive Order 13132 (64FR 43255, August 10, 1999). This action merely makes a determination based on air quality data and doesnot alter the relationship or the distribution ofpower and responsibilities established inthe Clean Air Act. Executive Order 12898 establishes a Federal policy for incorporating environmental- justice into Federal agency actions by directing agencies to identify and address, as

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appropriate, disproportionately high and adverse human health or environmental effects oftheir programs, policies, and activities on minority and low-income populations. Today's action involves determinations based on air quality considerations and affirms that the SJV attainedthe PM-10 NAAQS. It will nothave disproportionately high and adverse effects on any communities in the area, including minority and lowincome communities.

This rule also is not subject to Executive Order 13045 "Protection of Children from Environmental Health Risks and Safety Risks" (62 FR 19885, April 23, 1997), because it is not economically significant. The requirements ofsection 12(d) ofthe National Technology Transfer and Advancement Actof 1995 (15 U.S.C. 272 note) do not apply because it would be inconsistent with applicable law for EPA, when determining the attainment
status ofan area, to use voluntary

consensus standards in place of promulgated air quality standards and monitoring procedures that otherwise satisfy the provisions ofthe Clean Air. This rule does notimpose an information collection burden under the provisions ofthe Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.).

The Congressional Review Act, 5 U.S.C. section 801 et seq., as added by the Small Business Regulatory Enforcement Fairness Act of1996, generally provides that before a rule may takeeffect, the agency promulgating the rule must submit a rule report, whichincludes acopy of the rule, to each House ofthe Congress and to the Comptroller General ofthe United States. EPA will submit areport containing this rule and other required information to the U.S. Senate, the U.S. House ofRepresentatives, and the Comptroller General ofthe United States prior to publication ofthe rule* in the Federal Register. A major rule cannot take effect until 60 days after it is published in the Federal Register. This action is not a "major rule" as defined by 5 U.S.C. section 804(2).

Under section 307(b)(1) ofthe Clean Air Act, petitions forjudicial review of this action mustbe filed in the United States Court ofAppeals for the appropriate circuit byMay 19, 2008. Filing a petition forreconsideration by theAdministrator ofthis finalrule does not affect the finality ofthis rule forthe purposes ofjudicial review nor does it extend the time within which a petition forjudicial review may be filed, and shall not postpone the effectiveness of such rule or action. This action may not be challenged later in proceedings to enforce its requirements. (See section 307(b)(2).)
List ofSubjects
40 CFRParts52

Environmental protection, Air pollution control, Incorporation by reference, Particulate matter, Reporting and recordkeeping requirements.
40 CFRPart81

Environmental protection, Air pollution control, National parks, Wilderness areas.

DatedMarch 7,2008. Wayne Nastri, RegionalAdministrator, Region9. [FRDoc. E8-5188Filed 3-18-08; 8:45 am]

BILLING CODE 6560-50-P

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Part 180 (EPA-HQ-OPP-2007-0876; FRL-8344-1]
Spinetoram; PesticideTolerance; Technical Correction
AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule; technical correction.

SUMMARY: EPA issued afinal rule inthe Federal Register ofOctober 10, 2007, concerning the establishment ofa tolerance for the combined residues of the insecticide spinetoram. This document is being issued to correct a technical error, specifically, the omission ofthe complete tolerance expression under Unit V. and in the regulatory text section ofthe final rule. DATES: This finalrule is effective March 19, 2008. ADDRESSES: EPA has established a docket for this action under docket identification (ID) number EPA-HQOPP-2007-0876. To access the electronic docket, go to http:// www.regulations.gov,select "Advanced Search," then "Docket Search." Insert the docket ID number where indicated and select the "Submit" button. Follow the instructions on the regulations.gov website to viewthe docket index or
access available documents. All documents in the docket are listed in the docket index available in .regulations.gov. Although listed inthe index, some information is notpublicly available, e.g., Confidential Business Information (CBI) orother information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the Internet and will be publicly available only in hard copy form. Publicly available docket materials are available eitherin the electronic docket at http://www.regulations.gov,or, ifonly available inhard copy, at the Office of Pesticide Programs (OPP) Regulatory Public Docket in Rm. S-4400, One Potomac Yard (SouthBldg.), 2777 S. Crystal Dr., Arlington, VA. The hours of operation ofthis Docket Facility are from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The Docket Facility telephone number is (703) 305-5805. FOR FURTHER INFORMATION CONTACT: Bonaventure Akinlosotu, Registration Division (7505P), Office ofPesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone number: (703) 605-0653; e-mail address: akinlosotu.bonaventure@epa.gov. SUPPLEMENTARY INFORMATION:

I. General Information
A' Does thisActionApply toMe?

The Agency included in the final rule

a list ofthose who may be potentially affected by this action. Ifyou have questions regarding the applicability of this actionto aparticular entity, consult the person listed under FOR FURTHER INFORMATION CONTACT.

B.HowCanIAccessElectronicCopies ofthisDocumentandOtherRelated Information?

In addition to usingregulations.gov, you may access this Federal Register document electronically through the EPA Internet under the "Federal Register" listings at http:// www.epa.gov/fedrgstr.
II. WhatDoes this Correction Do?

The final rule, identified as FR Doc. E7-19947 that published in the Federal Register ofOctober 10, 2007 (72 FR 57492) (FRL-8149-9) is corrected to fix

a technical error, specifically, the omission ofthe complete tolerance expression forthe combined residues of the insecticide spinetoram under Unit V. (page 51498, second column) and in the regulatory text section (page 57499, first column) ofthe final rule.

Unit V. Conclusion, on page 57498, second column, is corrected to read as follows:

"Therefore, the tolerance is established for the combined residues ofthe insecticide spinetoram, expressed as a combination of XDE-175-J: 1-H-as-indaceno[3,2- dloxacyclododecin-7,15-dione, 2-[(6-deoxy-3-O-ethyl-2,4-di-O-methyl-a-Lmannopyranosyloxy-13-[[(2R,5S,6R)-5-(dimethylamino)tetrahydro-6-methyl-2Hpyran-2-yl]oxy]-9-ethyl-2,3,3a,4,5,5a,5b, 

### 14713

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