BryanW. Shaw, Ph.D., Chairman Buddy Garcia, Commissioner Carlos Rubinstein, Commissioner 

### - 

## .
:**~~·.->** .:.\ \ .: I·**!d:~** 

## fJLr.;·u:i: . !·

MarkR. Vickery, P.G., ExecutiveDirector 

## 10 APR -9 Pii 

## 1:55

TEXAS COMMISSION ON ENVIRONMENTAL QUALITY
Protecting Texas bgReducingandPreventingPollution 

## April6,2010

DocketNo. 2009-0802-SIP, ProjectNo. 2009-017-SIP-NR**~** 

### DocketNo. 2009-0932-RUL, RuleProjectNo. 2009-006-101-EN · DocketNo. 2009-0867-RUL, RuleProjectNo. 2009-019-101-EN

A1 Armendariz,PhD,Regional Administrator U.S. EnvironmentalProtectionAgency- Region 6 

### 1445 RossAvenue Dallas,Texas 75202-2733

. DearDr. Armendariz:
On March 10, 2010, the Texas Commission on Environmental Quality (Commission) adopted revisions to 

### the State Implementation Plan (SlP) for the control of ozone air pollution for the Houston-Galveston-Brazoria (HGB) 

### area.
The Commission adopted amendments to 

### 30 Texas Administrative Code (TAC) Chapter 101, Subchapter A, General Rules, Section 101.1; and SubchapterH, Emissions Banking and Trading, Division 6, Highly Reactive Volatile Organic Compound Emissions Cap and 

### Trade Program, 

### Sections 101.390

- 101.394, 101.396, and 

### 101.399

- 101.401; 30 TAC Chapter 101, Subchapter H, 

### Emissions Banking and Trading, Division 3, Mass Emissions C and

### Trade Pro 

### Sections 101.350 101.351 and 

### 101.353 and co · revisions to the SlP; and 

### GBAttsinmentDemonstration SlP Revisionforthe 1997Ei t-Hour Ozone Standard. Theserule changes and SIP revisions demonstrate that the HGB area 

### will attain the 

### 1997 eight-hour ozone National AmbientAir

### Quality Standardby June 15, 2019.
Enclosed are 

### the proposed revisions to the SlP, a public hearing certification, a 

### complete record ofthe public hearings, andtheaccompanying orders.· I 

### lookforward to yourexpeditious approval ofthese SlPrevisions. Sincerely, 

# B**~,;ktw.--·**

# B~haw,PhD.

Chairman BWS/jmm
Enclosures

cc: TheHonorableRickPerry, GovernorofTexas Mr. TobyBaker, Office ofBudget,Planning andPolicy, Office ofthe Governor Mr. Mark

### R Vickery, P.G., ExecutiveDirector,TexasCor!unissiononEnvironmental Quality

P.O. Box 13087 Austin, Texas 78711-3087 512-239'1000 1ntemetaddress: www.tceq.state.tx.usTexas Commission on Environmental Quality Public Hearings Odober28-29, 2009
Houston-Galveston-Brazoria (HGB) Attainment Demonstration SIP Revision forthe 1997 Eight-Hour Ozone Standard Projed Number2009-017-SIP-NR Volume 2 of2

# EVALUATION OF TESTIMONY

# Texas CommissiononEnvironmentalQuality INTEROFFICEMEMORANDUM

To: Commissioners Date: February 19,2010
Thru: LaDonnaCastafiuela, ChiefClerk MarkR.Vickery, P.G.,ExecutiveDirector**~1)** From: Susana

### M.Hildebrand, P

### .E,

# ChlefEngin~\ .\

# ~1)l

DocketNo.: 2009-0802-SIP Subject: CommissionApprovalforAdoption Houston-Galveston-Brazoria(HGB)AttainmentDemonstration StateImplementationPlan (SIP) Revision forthe 1997Eight-HourOzone Standard · RuleProjectNo. 2009-017-SIP-NR

BackgroundandreasonsfortheSIPrevision: The United States Environmental Protection Agency (EPA) reclassified the eight-county HGB area (Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller Counties) from a moderate to a severe nonattainment area for the 1997 eight-hour ozone National Ambient 

### Air Quality Standard (NAAQS)effective October31, 2008. The state isrequiredto submita SIPrevisionaddressingthe·
severe ozone nonattainment arearequirements ofthe Federal Clean

### AirAct(FCAA), 42 United States Code (USC), §7410byApri115,2010. ScopeoftheSIPrevision: A) SummaryofwhattheSIPrevisionwill do:

. . . . This SIP revision usesphotochemicalmodelingincombination with aweight ofevidence (WoE) evaluation to support a conclusion thatthe HGB areawill 

### attain the 1997 eight-hour ozone NAAQS by June 15, 2019. Demonstration ofattainment involves a photochemical modeling analysisthat predicts ozone design values in2018. Thephotochemicalmodelinganalysis consicicrrs federal, state, andlocalcontrolmeasures, including the proposed revisions to the Highly Reactive Volatile Organic Compounds Emissions Cap and Trade (HEC1) program and the Voluntary Mobile Emission Reduction Program (VMEP) and accounts for population and economic growth.

.The WoE evaluation includes a corroborative analysis and additional controlmeasuresnotexplicitlyaccountedforinthephotochemicalmodeling. · B) Scoperequiredbyfederalregulations orstatestatutes: Thisrevision containstheFCAA-requiredSIPrevision elements, including analysesforreasonablyavailable controltechnology(RAC1)andreasonablyavailable controlmeasures (RACM), a motorvehicle emissions budget(MVEB),transportationcontrolmeasures (TCMs ), anda contingencyplan. C)Additionalstaffrecommendationsthatarenotrequiredbyfederalrule orstatestatute: None. Statutoryauthority The authority to propose and adopt this SIP revision is derived from Texas Health and SafetyCode, Texas Clean 

### AirAct(TCAA), §382.002, whichprovides thatthepolicy andpurpose ofthe TCAA is to safeguard ·the state's air resources from pollution; TCAA, §382.011, which authorizes the commission to control the quality ofthe state's air; and §382.012, which authorizes the commissiontoprepare and develop a general, comprehensive plan forthe control ofthe state's air; and Texas Water Code, §5.102, General Powers, and §5.013, GeneralJurisdiction ofCommission.Commissioners Page2 February 19,2010

Re: DocketNo. 2009-0802-Sn>
TheFCAA,42USC, §§740l,etseq., requires statesto submit SIPrevisionsthat specifythe manner

### inyyhich the

### NAAQS willbe achieved andmaintained within each air quality e9ntrol**re~ion** ofthe state. Phase 1 of theEP A•s implementationrule forthe 1997 eight-hour ozone stahdard,published

### intheApril30, 2004; issue of the Federal Register (69 FR 23951), outlines classifications, atta.inment dates, and anti-backsliding principles. Phase 2 ofthe EPA's implementation rule for the 1997 eight-hour**~dard,** published 

### in the November29, 2005, issueofthe

### FederalRegister(70FR11612), outlinesthetequrrementsfor state**plans~** Effectonthe: A)Regulated community: The affectedregulated communitywill bethose associated

### with therulemakingsthat are

### p!U't**o~:~** Sn> revision. For further information, see the executive sUill)llaries.for the following rulemak:ings, whichare.beingadoptedconclmenilywiththis Sn>**~v!sion.** · . · • Rule Project No. 2008-019-115-EN, Volatile. Organic Compounds (VOC) Control TechniqueGuidelines (CTG)Update
• Rule Project No. 2009-006-101-EN, HECT Program Cap Reduction and Allowance Reallocation

. . . . . . • ·RuleProjectNo. 2009-019:-10l-;EN, MassEmissions Cap and Trade (MECT)**Pro~;Qap** IntegrityfortheHGBEight-HourOzoneNcmattainmentArea ·, · 

### t;·
Fiscalimpactinfol'll1ation onthepreviouslyreferencedrulemakings.associatedwiththis SIP revision is included 

### in the**e~ecutive** swnmilries.

### atid**preambl~s** fot the rulemalcings. See the execptive summaryandpreamble forRuleProjectNo. 2008-019-115-EN, VOC CTGUpdate;tegard.jngp:ffset lithographic printing operations for information on affected persons who were not affected previously. : .:
.

. This SJP revision.also includes local.con1tol measu.res (VMEP measures a'n.d TCMs)

### developed~d implemented through th€! Houston-Galveston Area Council (H-GAC), the regional metropQlitan transportationplanningagencyfortheHGB

### area. B) PubHc:

. . , The general publi¥ intheHGB and surrounding areas .will benefitfrom reducedground-levelozon,e cc>ncentrations duetoreduced emissions ofo,zone**pr~ursors.** 

### Ulere will 

### :be no

### fiscal 'impactonthe public. C)Agencyprograms: The Office of Compliance and Enforcement (OCE) conducts field investigations

. to verify compliancewiththerules addressed 

### in SIPrevisions. Enforcement ofanyrevisedrules inthis Sn> revision would not significantly increase the number offacilities investigated by·state and local governments. However, therule revisions may increase the OCE workload wheninvestigatingthe affectedfacilities

.. Staffsolicitedcomments onwhether itis appropriate toperform a mid-coursereview (MCR) and, if so, whatelements should becontainedinthe analysis. Staffalso recommendedthatthe.colillllission seekinput onthe appropriate dateto submittheMCR. An MCRcouldrequire additionalresourees and increase the Air. Quality Division workload. In respon.Se to comments received, the staff..will perform a 1997 eight-hour ozoneMCRfor.cominission consideration and approval and submittalto theEPA(see."Significantcliangesfromproposal"section). ' ·Commissioners Page3 February 19, 2010

Re: DocketNo. 2009-0802-SIP
Stakeholdermeetings: The HGB Eight-Hour Ozone SIP Stakeholder Group met March 25 and 26, and November 3, 2008, to discuss development ofthe SIP revision, review modeling updates, and provide public input on potential control strategies. Meetings were held with the H-GAC and local governments on· May 15 and July22, 2008, to provide baekground onthe SIP revision requirements and discuss the process to identify potential
measuresthatcanbeimplemented atthelocal level. StaffalsoparticipatedinmeetingsheldbyH-GACwith stakeholder·groupsrepresenting airports and airlines, railroads, tug boatoperators, the construction industry, ports and users ofmarine equipment, users ofnon-roadmobile industrial equipment, local governments, and thepublic.
Stakeholdersprovided comments on a broadrange ofpotential control measures forpoint, 

### area, andmobile
sources of ozone precursors. Stakeholders also commented that evaluation and detennination ofcontrol strategies should be based on ozone reduction benefits as well as technical and economic feasibilities. Stakeholders' suggested potential control measures were included·in the RACM analysis and the H-GAC TCMsandVMEPs.
Publiccomment: Publichearings for the proposed SIPrevision and associatedrulemakings wereheldonOctober28, 2009, at 2:00 p.m. and 6:00 .p.m., at the H-GAC offices in Houston; and on October 29, 2009, at 3:00 p.m., atthe Texas Commission on Environmental Quality (TCEQ) headquarters in Austin. Question and answer sessions were held 30 minutes priorto the hearings. Neither the October 28, 2009, hearing scheduled for 6:00p.m. nor the October 29, 2009, hearing was officially opened because no party indicated a desire to provide comment Fivepersons presented 

### oral comments concerningthis SIP revision atthepublic hearing heldat2:00p.m.onOctober28, 2009, inHouston.

The public comment period opened on October 9, 2009, and closed on November 9, 2009. Written comments were accepted via mail, fax, and through the eComments system. There were 25 written comments received. Generally, the comments concerned support for or opposition to this attainment demonstration SIP revision, theuse ofWoE, conducting an·MCR, attainment ofthe 1997 eight-hour ozone standard inthe HGB 

### area, and specific control strategies as well asthe RACT and RACM analysis. While several comments expressed support for this attainment demonstration SIP revision and its photochemical modeling analysis and weight ofevidence determination, a number ofcommenters contended that this SIP revision does not demonstrate attainment of the 1997 eight-hour ozone standard by the June 15, 2019, deadline. Some ofthe commenters who opposed this SIP revision also expressed opposition to the use of WoEto augmentphotochemicalmodeling. ·
Comments were received regarding attainment in the HGB area regarding a pending lowered eight-hour
ozone standard in 2010. The Environmental Defense Fund (EDF) and the Galveston-Houston Association for Smog Prevention (GHASP) commented that the TCEQ has failed to initiate additional reductions that will be necessary in order to attain the more stringent eight-hour ozone standard, which is under considerationbythe EPA. The CityofHouston (COH), suggestingthatthe HGB area is attainingthe 1997 eight-hour standard, recommended

### thatthe TCEQ develop a redesignationrequestandmaintenanceplanfor submissiontotheEPAandtoconcentratefuture effortsontherevisedozone standard.

Several commenters proposed that the TCEQ undertake an MCR and offered suggestions for content and timing of an MCR for the HGB area. There were also numerous comments concerning the general effectiveness of control measures included in this attainment demonstration SIP revision, and statements were submitted about specific control measures, including comments concerningthe rules associated with this attainment demonstration SIP revision. For a summary of comments more directly related to the 30Commissioners Page4 February 19,2010
Re: DocketNo. 2009-0802-SIP
Texas Administrative Code (TAC) Chapter 101 :MECTProgram Cap Integrity (Rule ProjectNo. 2009-'019-

.·. 101-EN).andHECT-Program Cap Reducti:on'and AUowanceReal.location**(2009~006~101-EN)** and Chapter

115 Offset Lithographic Printing rule revisions (Rule Project No. 2008-019-US-EN), see the executive summarymemos;foreachofthoserules. ;•· , .. ,, Significantchangesfrom proposal:

. .. Significant changes were made'to the VOC RACT update element of this SIP revision in response**~o** conunents. Staffproposedthat RACT for two CTG categories was fulfilled through c1,11Tent 

### state rules and permitting requirements. These categories include: Flexible Packaging Printing; and Paper, Fih:o, .and-FCiil Coatings. However, in response to comments from the EPA, the RACT determinations for these two categories were withdrawn so .staffmayreevaluate theRACT analyses. The RACT determinQtion.fot the FiberglassBoatManufacturingCTGcategoty.wasproposed

## as notrepresentingRACTfor-the HGB area due tothe potential econori:rlc impact to small businesses; howeVer, additional staffreseareh indicates 

### thatno sources meeting thf,LCTG appliCability exist 

### .iti the HGB 

### area:.
.Therefore, the RACf deteni\ination:for FiberglassBoatManufacturingwas changedto a negative declaration.

In preparingthe response to the comments, staffreviewed the 2006 baseline, a.S well as the 2018 projecte9 emissions, includingthereductiontothereconciled emissions ofhighlyreactivevolatile organic compoli!l$ (HRVOC), For the 2006 baseline emissions, updates were made to.the point sources and the non-road mobile sources. The updates to the point sources priniarily included accounting for annualiz.OO emissjons from upsets, mainteliance, startups, and shutdowns, The revision to the non-road mobile source**emissio~** reflectsthe.use .ofthe updatedTexas NONROAD (TexN) model with a more recentdatabase ofequipment populations. Forthe2018projectedemissions,updateswere alsomadeto thepointsources andthenon-road mobile sources. The updates to the point sources included changes in.the application of**growth.f~ors,to** non-:MECT sources, a revisionto the :MECT allocations reflecting more recent emission certifications, and removing the**r~duction** ofreconciled**emissio~** ofHRVOC in 2018. Similar to the 2.00.6 baSeline;_:t;he revision to the 2018 non-road mobile source emissions reflects the use ofthe upW.,ted TexN model

### with a morerecent-databaseofequipmentpopulations.
The**cbang~s** inthe2006baseliile and2018 future base emissionsresulted in slightly smaller,2018 projected eight-hour ozone design va.J.ues. Allregulatory monitors have projected eight-hour ozone designvalues less 

### :than 87 parts perbillion (ppb). ·Theprojected·control strategy2018 eight-hour ozone design values for tbe highesttwo monitors are also slightly lower

### than originallypresented

### in theproPQsal (i.e., DRPK: 86.3 ppl> and BA YP: 85..3 ppb) due to the emission-:-related changes

.

### in the 2006 baseline and 2018**~ ba..~e**  modelingresults.

. . .'/

To address comments·tothe SIPrevisionandto suppleinent.thecorroborative analyses ofChapter5: Weight ;ofEvidence, additional analyses that address the effects ofmeteorology and economic factors on ozone trends have been included 

### in Appendix I: CorroborativeAnalysisfor the HGB AttainmentDemonstratioh SIP Revisionfor· the 1997 Eight-Hour Ozone Standard as well as an. emissions. trend analysis. The discussion ofmodel responSe to emission changes bas been broadened and trends in VOC reactivity have alsobeenanalyzedand alsoaddedtoAppendixI.

### Commissioners PageS February 19, 2010
Re: DocketNo. 2009-0802-SIP In

### response to comments received, the executive director's staffwillperform a 1997 eight-hour ozone MCR for commission approval and submittal to the EPA concurrently with the revised ozone 

### standard SIP revision, which is scheduled to be due to the EPA in December 2013. The MCR 

### will involve a thorough evaluation ofall 

### modeling, inventory data, 

### and othertools and assumptions used to develop the attainment demonstration. This effortwillinclude areview ofthe controlmeasures, WoE, and contingencyplanas well
as 

### additional analysis that may include photochemical modeling if

### appropriate. The MCR will 

### contain further evaluation ofthe potential state 

### and federal measures and new programs or regulations. 

### This MCR will

### also includetheongoingassessmentofnewtechnologies and innovative ideas forpossible inclusion into theplan.
The TCEQ executive directorwillcommittoinclude for commission.approval sufficientadditionalmeasures to 

### equal 3 

### percent ofthe emissions in the adjusted baseyear

### inventory to be implemented inthe eventthat the HGB area does not attain the 1997 eight-hour ozone standard by

### June 15, 2019, atthe time ofan MCR forthis attainmentdemonstration SIPrevision.

. In 

### response to comments received applicable to the rules associated with this SIP revision, substantive changes were madetotheChapter 101 and 115 rulerevisions, which

### are addressed inthepreambles forthose rules.

Potentialcontroversialconcernsandlegislativeinterestremainingafterproposalandpubliccomment: In

### additionto photochemicalmodeling,this

### SIPrevisionrelies onWoE, including corroborative analysis and discussion of additional control measures not included in the photochemical modeling, to demonstrate

. attainment. The commission received comments statingthat the attainment demonstration should be based solelyonthephotochemical modeling and that becausethe photochemical modeling analysis shows thatthe proposed control measures will not be sufficient to demonstrate attainment by June 15, 2019, this SIP revision shouldbe 

### disapproved. ·
RACT 

### determinations were not made for all 

### ofthe 11 CTGs 

### issued by the EPA 

### between 2006 and 2008. While not stated in formally submitted comments, the EPA has 

### verbally indicated to staffthat it may issue notices offailure to submit

### to statesthat

### have notyetaddressed all

### ofthe CTGs. TheEPA'sissuance ofsuch anotice would start

### an 18-month sanctionsclock. The TCEQ mayneedto addressthe remaining CTGs in a future SIPrevision.

Doesthis SIPrevision affectanycurrentpolicies orrequiredevelopmentofnewpolicies? 

### No.

Whataretheconsequences ifthis SIPrevision doesnotgo forward? 

### The legalrequirementisto submitan attainmentdemonstration SIPrevisionforthe 1997 eight-hourozone standardbyAprill5,2010. Not submittinga SIPrevisiontotheEPAcouldresultin aFederal ImplementationPlan and/orfederal sanctions.

AretherealternatiVestothisrevision? 

### This SIPrevisionis requiredbyfederal statute. Thereareno alternatives. Keypointsinadoptionrequestschedule: TexasRegisterproposalpublicationdate: 

### NA Anticipated TexasRegisterpublicationdate: 

### NA Anticipated effective date: 

### NA Six-monthTexasRegisterfiling deadline: 

### NA

### Commissioners Page6 February 19, 2010
Re: 

### DocketNo. 2009-0802-SIP

.Agencycontacts: 

### LolaBrown, SIPProject

### Manager; 239-0348, Air

### QilalityDivision

·JohnMinter, StaffAttorney, 239·0663

cc:
.:ChiefClerk,

### 5copies ExecutiveDirector'sOffice SusanaM. Hildebrand, P.E. KevinPatteson 

### Curtis Seaton DanielWomack ' Office

### ofGeneral 

### Counsel 

### LolaBrown

.**~;,** ' i •**~ ~**  .

. 'Responseto CommentsReceived Regardingthe Houston-Galveston-Brazoria (HGB) 1997 Eight-HourOzoneAttainmentDemonstration StateImplementation Plan (SIP) Revision

Public hearings for this proposed attainment demonstration SIP revtston and associated rulemakings were held on October 28, 2009, at 2:00 p.m. and 6:00 p.m., at the HoustonGalveston Area Council offices in Houston; and on October 29, 2009, at 3:00p.m., at the Texas Commission on Environmental Quality (TCEQ) headquarters in Austin. Question and answer sessions were held 30 minutes prior to the hearings. Neither the October 28, 2009, hearing scheduled for 6:00 p.m. nor the October 29, 2009, hearing were officially opened because no party indicated a desire to provide comment. Five persons presented oral comments concerning this attainment demonstration SIP revision at the public hearing held at 2:00 p.m. on October 28, 2009, in Houston. The public comment period opened October 9, 2009, and closed November 9, 2009. The commission received comments from the 8-Hour Ozone SIP Coalition (Coalition), Albemarle Corporation (Albemarle), AmericanAcryl, Arkema Inc. (Arkema), BCCA Appeal Group (BCCA), City ofHouston (COH), Clean Air Institute ofTexas (CAIT), Environmental Defense Fund (EDF), Galveston-Houston Association for Smog Prevention (GHASP), Houston Sierra Club (HSC), Houston-Galveston Area Council (H-GAC), Kaneka Texas Corporation (Kaneka), KIDS for Clean Air (KIDS), League ofWomen Voters ofthe Houston Area (LWV Houston), LyondeliBasell Industries (LyondeiiBasell), PL Propylene LLC (PL Propylene), Printing Industries ofthe GulfCoast (PIGC), Sustainable Energy and Economic Development Coalition (SEED), Texas Association ofBusiness (TAB), Texas Chemical Council (TCC), Texas Oil and Gas Association (TxOGA), Texas Petrochemicals, United States Environmental Protection Agency (EPA), and one individual. Albemarle supported comments made by TCC and the Coalition ofManufacturers for Air Quality (COMAQ). No comments were received from COMAQ concerning this attainment demonstration SIP revision. CAIT, KIDS, SEED, and one individual incorporated by reference any comments submitted by EDF and HSC. EDF and GHASP incorporated by reference as part oftheir comments and for the administrative record, EDF's January 30, 2008, comments on the EPA's proposed rulemaking for "Clean Air Act Reclassification of the Houston/Galvestori/Brazoria Ozone Nonattainment Area; Texas" as published in the December 31,2007, issue ofthe FederalRegister (72 FR 74252) as well as all cited documents and studies included in their comments. Comments more directly related to the 30 Texas Administrative Code (TAC) Chapter 10I Mass Emissions Cap and Trade (MECT) Program Cap Integrity (Rule Project No. 2009-019-10I-EN) and Highly-Reactive Volatile Organic Compounds Emissions Cap and Trade (HECT) Program Cap Reduction and Allowance Reallocation (2009-006-101-EN) and 30 TAC Chapter 115 Offset Lithographic Printingrule revisions (Rule ProjectNo. 2008-019-115-EN), which are incorporated by reference into this attainment demonstration SIPrevision, are responded to in the Response to Comments section ofthe preamble to each ofthose rulemakings. Those comments are included in this attainment demonstration SIP revision through the adoption ofthose rules. Some changes
were made to the proposed version ofthis attainment demonstration SIP revision in response to those comments.

I of53Contents General Comments
...............................................................................................................................4 Evaluation ofAttainment Demonstration SIP

....................................................................................4 General Supportfor AttainmentDemonstration SIPRevision

................................................4 Mid-Course Review

.................................................................................................................5 Contingency Plan

.....................................................................................................................6 Rec'lassification

........................................................................................................................6 Attainment ofStandard

.......................................................................................................................6 1997 Eight-HourOzone Standard

............................................................................................6 Revised Eight-Hour Ozone Standard

.......................................................................................7 One-HourOzone Standard

.......................................................................................................7 Air Quality

..........................................................................................................................................8 Emission Reductions

................................................................................................................S Health and Economic Welfare

.................................................................................................9 Control Strategies Discussion
............................................................................................................10 HRVOCEmissionsCap and Trade (HECT) Program

.....................................................................10 Mass Emissions Cap and Trade (MECT) Program

..........................................................................11 OffsetLithographic Printing Rule Revisions

...................................................................................13 Identification ofMostEffective OzoneControl Strategies

..............................................................13 Mobile Sources

.................................................................................................................................14 Emissions Inventory

.........................................................................................................................15 Reasonably Available Control Technology (RACT), Reasonably Available Control Measures (RACM)
..............................................................................................................................16 RACT, RACM Adequacy

................................................................................................................16 RACT

...............................................................................................................................................17 RACM

..............................................................................................................................................24 Flare TaskForce Initiative

.....................................................................................................27 Photochemical Modeling
....................................................................................................................28 Support for Attainment Modeling and Weight ofEvidence (WoE)Analyses

.................................28 Weight ofEvidence (WoE)

..............................................................................................................30 Emissions Projections

.......................................................................................................................44 Emissions Reconciliation

.................................................................................................................48 Retrospective Modeling

....................................................................................................................49 Non-Ozone Emissions Reductions

...................................................................................................51 Photochemical·Modeling Improvements

.....,....................................................................................52 Inclusion ofPowerPlant Emissions Outside ofthe HGB Area

.......................................................53

2 of53List ofFigures Figure Figure I Figure 2
Figure 3
Figure4
Figure 5
Figure 6 Figure 7 Figure 8 Figure 9 Figure I0 Figure 11 Figure 12 Figure 13
Figure 14 Figure 15 Figure 16 FigureName Wind Datafrom Houston Aldine Meteorologically Adjusted Ozone Trends in the HGB Area from 1997 through 2008 (Source: EPA) Number ofOzone-Conducive Days and Number ofOzone-Conducive Days with OzoneGreaterThan 84 ppb (Source: URS Corporation) Forecasted and Actual Eight-Hour Ozone Exceedance Days (1997 NAAQS) in the HGB Area Frequency ofMorning Wind Direction and Wind Speed by Month in the HGB Areafor 2000, 2004, 2008, and 2009 Gross Domestic Product ofTexas Metro Area Business Cycle Index, Houston-Sugarland-Baytown Gross Domestic Product ofSelected Petroleum Related Industries Weekly GulfCoast (PADD 3) Crude Oil Inputsto Refineries Weekly PercentUtilization ofRefinery Operable Capacity, PADD 3 RFP NOx Emission Trends from 2002 to 2018 RFP VOC Emission Trends from 2002 to 2018 2 km Modeling Domain Grid Cells Projecting Eight-Hour Ozone DVF Greater than 84 ppb, and 7x7 Grid Cell Arrays for Regulatory Monitors HGB Point Source VOC and NOx EmissionTrends from 2003 through 2007 Modeled and Observed Response to Emission Changes between 2000 and 2006 Modeled and Observed Response to Weekend Emission Reductions

3 of53GENERALCOMMENTS Evaluation ofAttainmentDemonstration SIP 

### GeneralSupportforAttainmentDemonstrationSIPRevision BCCA and the Coalition supported the proposed demonstration that the HGB area will attain the 1997 eight-hourozone standard by the attainmentdeadline of2019. AmericanAcryl and Arkema appreciated efforts by the Texas Commission on Environmental Quality (TCEQ) to develop programs that contribute to compliance with the National Ambient Air Quality Standards (NAAQS).
COH commented thatthe TCEQ is making progress in reducing emissions. LyondellBasell commented that photochemical modeling demonstrates that the proposed Highly Reactive Volatile Organic Compounds (HRVOC) Emissions Cap and Trade (HECT) Program allowance cap reduction, in addition to stationary and mobile source emissions reduction programs, will contributeto attainment ofthe 1997 eight-hourozone standard in the i-IGB area. Thecommission appreciatesthe supportand is committed toworkingwith local entities and theEPAto ensure attainmentofthe 1997 eight-hourozone standardin the HGB area.
COH commented that the TCEQ should develop a redesignation request to attainment and prepare the required maintenance plan for submission to the EPA as expeditiously as possible. COH also commented that the TCEQ should finalize the proposed attainment demonstration SIP revision and submit it to the EPA in 2010 so that proposed control measures can be implemented to assure continued ozone reductions, and that the proposed attainment demonstration SIP revision may be incorporated into the maintenance plan. COH was also hopeful that ozone levels could be maintained for the necessary length of time to have the nonattainment designation removed for the HGB area.
The commission has developed and adopted this attainment demonstration for the 1997 eight-hour ozone standard in an expeditious manner and will submit this attainment demonstration SIPrevision to the governor's office in time to be provided to the EPA by the April 15, 2010, deadline. Although preliminary data for 2007 through 2009 show that the HGB area is monitoring attainment ofthe 1997 eight-hour ozone standard, on January 7, 2010, the EPA proposed to strengthen the eight-hour primary ozone NAAQS to a level within the range of0.060 to 0.070 ppm. The EPA bas also proposed a distinct cumulative, seasonal secondary standard within the range of7to 15 ppm-hours. The EPA is scheduled to issue the final standards by August 31, 2010. According to the EPA's accelerated schedule, states will be required to submit recommendations for the attainment status of areas under the revised primary ozone NAAQS by January 2011 and final area designations are scheduled to be issued by July 2011 and become effective in August 2011. Nonattainment area SIP revisions are scheduled to be due to the EPA in December 2013. At the time of this writing, the EPA bas not published guidance on bow the 2010 ozone NAAQS should be implemented.
Given the short time frame in which the commission must provide recommendations for nonattainment areas and react to the EPA's implementation guidance to develop SIP revisions for the revised ozone NAAQS, the limited resources available are best utilized in assessing and preparing for the revised ozone NAAQS. The TCEQ will pursue requesting redesignation ofthe HGB area to attainment for the 1997 eight-hour ozone standard when all elements necessary for redesignation can be considered in the context of the EPA's implementation rule requirements for the 2010 ozone NAAQS. The TCEQ will work with theEPAandtheHGB regional stakeholders in this effort.

4 of53

### Mid-CourseReview EDF, the EPA, GHASP, H-GAC, LWV Houston, and TCC supported the TCEQ conducting a mid-course review (MCR). The EPA also suggested that the TCEQ conduct photochemical modeling during the MCR. H-GAC encouraged the TCEQ to include an MCR in the proposed attainment demonstration SIP revision to assure that adequate measures are included to achieve attainment as expeditiously as possible.
The EPA pointed out that the MCR should show whether implemented control measures are sufficient. H-GAC suggested that the MCR include an assessment ofthe weight of evidence (WoE) to provide an opportunity to adjust the attainment demonstration SIP revision for future technology changes and information and to include additional funding if appropriated or amendments to commitments if funding is reduced. TCC commented that the MCR should evaluate the need to implement a 25 percent HRVOC emissions cap reduction and include additional photochemical modeling to determine the extent to which the HRVOC cap should be reduced in orderto attain the 1997 eight-hour ozone standard.

EDF and GHASP suggested that the MCR should occur in the 2012-2013 time frame to allow ample time for the implementation of additional controls, if any, needed to demonstrate attainment by 2019. The EPA noted that the revised eight-hour ozone standard SIP revision will be due to the EPA in 2013, sothe MCR could be submitted concurrently with the SIPrevision for the revised ozone standard. TCC suggested that the MCR be conducted prior to the first stepdown period for the proposed HECTprogram changes or in the 2011-2013 time frame.
To ensure that the HGB area is in attainment of the 1997 eight-hour ozone standard by June 15, 2019, and that the controls to get there are the most cost-effective, technologybased solutions possible, the executive director commits to performing a 1997 eight-hour
ozone standard MCR and submitting it to the commission for consideration. With commission approval, the results ofthe MCR would be submitted to the EPA concurrently with a SIP revision for the EPA's revised ozone standard, which is scheduled to be due to the EPA no laterthan December 2013. In the event that the schedule for the revised ozone standard is changed by the EPA, the schedule for the MCR submission will change accordingly. This effort will involve a thorough evaluation ofall photochemical modeling, inventory data, and other tools and assumptions used to develop the attainment demonstration. The MCR will include a review of the control measures, WoE, and contingency plan as well as additional analysis that may include photochemical modeling if appropriate. Itwill also include the ongoing assessmentofnew technologies and innovative ideas for possible inclusion into the plan. Forfurther information regarding the MCR, see Chapter6: OngoingFutureInitiatives, Section 6.3.1: Mid-CourseReview(MCR).
The commission commits to continue working with the EPA and the HGB regional stakeholders in an open, public consultative process to ensure that the MCR is a comprehensive andthorough evaluation.
TCC requested that photochemical modeling scenarios be performed during an MCR to determine ifthe 84 parts per billion (ppb) standard could be maintained while reducing the 25 percent HECT cap. TCC specifically recommended HECT cap reduction scenarios of5 percent increments for such an analysis.
When an MCR is developed for the HGB area, the TCEQ will evaluate control strategy scenarios needed for demonstrating attainment of the ozone standard. Since ozone formation is sensitive to anthropogenic HRVOC levels, this specific emission category will continue to receive attention in any future ozone attainment demonstration SIP revision developed by the TCEQfor the HGBarea.

5 of53ContingencyPlan TCC recommended that the TCEQ, as a potential contingency item during the 2009-2018 period, note emissions reductions ofvolatile organic compounds (VOC) or nitrogen oxides (NOx) that
are anticipated as aresultofconsent decrees.
It is not clear from the comments to what specific consent decrees the commenters are referring. The commission does not agree thatpreviously entered EPA consent decrees are an appropriate measureto beincluded as a contingency measure. Though it is possible that VOC and NOx emission reductions may occur as a result ofconsent decrees in the HGB nonattainment area, the timing ofthe emissions reductions and the quantity ofreductions that are surplus to those that are accounted for in the photochemical modeling analysis are extremely difficult to ascertain. Since the emissions reduction for contingency would need to take place during a specific timeperiod and must total to a specific amount (3 percentof the adjusted base-year inventory), the commission has not included consent decrees as a possible contingency measure as part of this attainment demonstration SIP revision. The commission has madeno changesin response to this comment. Reclassification EDF and GHASP incorporated by reference as part oftheir comments on the proposed attainment demonstration SIP revision comments submitted by EDF on January 30, 2008, to the EPA proposed rulemaking for reclassifying the HGB nonattainment area, Docket No. R06-0AR-2007- 0554, published in the Federal Register on December 31, 2007. EDF and GHASP also referenced comments made by the EPA regarding a previous SIPrevision.
The commission acknowledges these comments to the EPA as part of the record for this proposed attainment demonstration SIP revision. To the extent those comments are also specifically referenced in other comments made aboutthe current SIPaction, responses are made accordingly elsewhere in this response to comments. However, the commission is not responding specifically to the January 30, 2008, comments originally submitted only to the EPA but not submitted to the TCEQ, since the January 30, 2008, comments are relevant only to the EPA's action reclassifying the HGB area and not for this proposed attainment demonstration SIP revision. The commission has made no changes in response to this comment. COH, EDF, and GHASP commented that they opposed the previous double bump-up request and the prolonged attainment timetable for the HGB area.
The commission acknowledges these comments and the concerns associated with the later attainment date. Because the Federal Clean Air Act (FCAA) requires that the commission implement control strategies as expeditiously as practicable, the TCEQ bas set an aggressive schedule to implement the 25 percent reduction in the HRVOC cap. The initial cutin reductions begins in 2014 in advance ofthe 2019 attainment date. Underthe FCAA, §181, the EPA was required to grant the governor's request to reclassify the HGB area and the final rule was effective on October31, 2008 (73 FR56983). Thus, the comments are not relevant to this SIP revision and are outside the scope ofthis attainment demonstration SIP revision. Thecommission bas made nochanges in response to thesecomments.
AttainmentofStandard J!J!J7Eigbt-HourOzoneStandard HSC and LWV Houston commented that the TCEQ has not yet successfully attained the 1997 eight-hour ozone standard in the HGB area. The EPA and LWV Houston expressed concern that the HGB areamay still be in nonattainment ofthe 1997 eight-hourozone standard in 2018.

LWV Houston rejected this proposed attainment demonstration SIP revision because it does not, on its face, meet the I997 eight-hourozone standard. LWV Houston expressed concern about the 6 of53TCEQ's credibility in developing a plan that will lead to attainment ofthe 1997 eight-hour ozone standard by thedeadline.
The commission is committed to attaining the 1997 eight-hour ozone standard in the HGB
area as expeditiously as practicable. The current preliminary 2009 design value of84 ppb and this attainment demonstration SIPrevision are confirmation that the TCEQ will attain the 1997 eight-hourozone standardin the HGB area by theJune 15, 2019, attainmentdate. The commission expects that proposed new control measures, along with existing control
measures being implemented in the HGB area, will improve the area's air quality by removing ozone precursors from theairshed.
As part of this demonstration, the TCEQ uses photochemical modeling, which is a predictive tool that simulates the changes of ozone precursor concentrations in the atmosphere using a set ofmathematical equations characterizing the chemical and physical processes in the atmosphere. In specifying requirements for photochemical modeling, the EPA allows for the use of corroboratory WoE by states to support demonstrations of attainment since there is always uncertainty in numerical forecasts offuture events. The TCEQ has analyzed the appropriate reductions necessary for attainment ofthe 1997 eighthour ozone standard as described in this attainment demonstration SIP revision. The commission has made no changes in response to these comments.
RevisedEight-HourOzoneStandard COH, EDF, and GHASP commented that the EPA is considering lowering the eight-hour ozone standard. COH stated that forward progress must be maintained because the eight-hour ozone standard will be tightening.

EDF and GHASP commented that the modeling contained in the proposed attainment demonstration SIP revision fails to initiate additional reductions to comply with a lowered ozone standard.
The commission is aware of the EPA's**r~cent** proposal to reduce the NAAQS for ozone. Thecommission contendsthatthis SIPrevision continues to improveairqualityin theHGB
area. Thecommission will prepare SIPrevisions to attain and maintain the new eight-hour
ozone standard in those areasonce nonattainment areas for the revised standard have been designated by the EPA. The commission has made no changes in response to these comments.
One-HourOzoneStandard EDF and GHASP commented that, despite recent improvements in ozone levels, the HGB area has failed to reduce emissions ofozone precursors to levels sufficient to ensure attainment ofthe revoked one-hour ozone standard, the 1997 eight-hour ozone standard, and a revised eight-hour
ozone standard currently under consideration by the EPA. Further, EDF and GHASP asserted that the TCEQ must demonstrate why the dramatic increase in overall VOC emissions in the HGB area is not backsliding underthe one-hour ozone standard.
In the 2004 HGB MCR SIP revision, 2007 future-year point source VOC emissions were 255 tons per day (tpd) compared to the 2018 future-year emissions of 290 tpd in this attainment demonstration SIPrevision. The corresponding NOx emissions are 512 tpd and 377 tpd, respectively. Since modeling sensitivities for both SIP revisions indicate that, with the exception of HRVOC, ozone formation is much less sensitive to VOC than NOx reductions, the increase in projected point source VOC emissions should not compromise attainment. As discussed elsewhere in this response to comments, the increase in VOC is due to growth projections, primarily from area and non-major point sources; it is not a result of a relaxation or removal of a SIP requirement. Therefore, the increase is not backsliding undertheone-hourozone standard.
7 of53Regarding the one-hour standard, there is no requirement to ensure attainment of this standard because it bas been revoked. Phase 1 ofthe EPA's rules implementing the 1997 eight-hour ozone standard published in the April30, 2004, issue ofthe 

### FederalRegister (69 FR 23951) requires that areas designated nonattainment for the one-hour standard at the time ofdesignation for the eight-hour ozone standard meet certain requirements including having an approved one-hour attainment demonstration. The EPA approved the HGB attainment demonstration for the one-hour standard published in the September 6, 2006, issue of the 

### Federal Register (71 FR 52656). The commission bas made no changes in response to this comment. CAIT, KIDS, SEED, and one individual commented that air monitoring data have proven false the assumption thatthe current eight-hourozone standard is more protective ofhuman health than the previous one-hour ozone standard. Specific mention was made ofexceedances ofthe onehour standard during 2007 through 2009 when violations oftheeight-hourstandard did notoccur. CAIT, KIDS, SEED, and one individual claimed that the current form ofthe eight-hour ozone standard is flawed because it compensates for weather fluctuations providing unusually high design values but does not do so for fluctuations thatprovide unusually low design values.
As part ofthe periodic review ofthe NAAQS required by the FCAA, the structure ofthe ozone standard is developed by the EPA with substantial input from various scientific and health experts from across the United States. An exceedance of the one-hour ozone standard does not necessarily imply that the current 1997 eight-hour ozone standard is not more protective of human health. Further, the EPA has established through scientific review thatthere is insufficient evidence to retain the one-hourozone NAAQS in orderto be protective of public health. For more detail about the health impacts of ozone exposure, several documents related to the review of the 84 ppb ozone standard are available at http://www.epa.gov/ttn/naags/standards/ozone/s o3 pr.html.
Air Quality 

### EmissionReductions BCCA and the Coalition commented that the majority ofozone precursor emissions reductions have been achieved through programs aimed at the industrial source sector, and they cited that decreases in the ambient concentrations of ethylene and propylene suggest a considerable decrease in overall industrial emissions ofthese compounds since 1995. Further, BCCA and the Coalitioncommented that this finding agrees with early reports from the Texas Air Quality Study II (TexAQS II) field program indicating a decrease in ethylene emissions along the Houston Ship Channel.
The commission acknowledges that programs aimed at the industrial source sector have been successful in reducing ozone precursor emissions in the HGB nonattainment area. The commission's goal in the development ofthis proposed attainment demonstration SIP revision is to advance a plan that will result in the HGB area meeting the 1997 eight-hour ozone standard as soon as practicable and in the most economically feasible manner consistent with continued economic growth in the greaterHouston area. The commission's overall strategy for improving air quality in the HGB area is working, as proven by the 26 percent decrease in the one-hour ozone design value and the 19 percent decrease in the eight-hour ozone design value between 2000 and 2008 during a simultaneous increase of21 percentin population.
Emission reductions from stationary sources have been substantialoverthe past 10years in theHGB area. More than 500 tpd ofNOx emissions were reduced from the electric utility, industrial, commercial, and institutional sectors through the30TAC Chapter 117: 

### Control ofAir Pollution from Nitrogen Compounds rules and the NOx MECT program. In addition, a wide range ofVOC control strategies were implemented for stationary sources

8 of53in theHGB area, impactinglarge industrial facilities such as refineries to smallerbusinesses such as printingoperations.
The commission concurs with the comment that the propylene and ethylene trends have shown decreases in their ambient concentrations. This is discussed in greater detail in Chapter 5: 

### Weight ofEvidence, Sections 5.3.6: 

### Ambient VOC Concentrations, 5.3.7: 

### Geographic Patterns in Ambient HRVOC Concentrations Near the Houston Ship Channel, and 5.3.8: 

### Ambient Total VOC Concentrations of the proposed attainment demonstration SIP revision. Thecommission has made nochanges in response to this comment.
The EPA commented that modeling conducted for the proposed attainment demonstration SIP revision indicates that, even with additional federal measures, the area will not reach attainment by 2018; therefore, further reductions not included in this proposed attainment demonstration SIP revision may be necessary to attain the 1997 eight-hour ozone standard.
The FCAA defines nonattainment based upon the number ofexpected exceedances at any monitor in a region. As long as monitored data show that the number of expected exceedances is no greater than one, then the area is in attainment. The statistic used in the attainmenttest is based upon this definition andis defined as thehighest design value atany monitor in the region, where each monitor's design value is the fourth-highest one-hour
ozone concentration measured at the monitor in the most current three-year period (adjusted for incomplete data, if applicable). Thus, the FCAA allows a region a limited number of exceedances of the standard without causing a violation. The EPA guidance explicitly allows modeled values to exceed the standard in attainment demonstration modeling, provided the exceedance is very limited in time and space, and provided that the state can supply additional compelling evidence that the area will not be in violation in its attainmentyear. These ancillaryargumentsarecollectively known asWoE.
Conservative photochemical modeling for the 2018 future case, the current preliminary 2009 HGB area design value of84 ppb, and the WoE analysis demonstrate that the HGB
area will attain the 1997 eight-hour ozone standard. The executive director commits to perform a thorough MCRconcurrentlywith the revised ozone standard SIPrevision, which is scheduled to be due to the EPA in December 2013, to help the commission identify additional measures orchangepreviously adopted measures to ensurethatcompliance with the 1997eight-hourozone standardis maintained.
Health andEconomic Welfare COH commented that the TCEQ should bring the HGB area into attainment with the ozone standard to protect human health and provide an economic boost for the HGB area. COH further commented that the TCEQ should make the HGB areaa priority.
EDF, GHASP, and HSC commented that the TCEQ should bring the HGB area into attainment with the 1997 eight-hour ozone standard to protect human health. EDF and GHASP stated that the SIP is the best opportunity that the state has to require emission control measures to protect human health from air pollution in the HGB nonattainment area. EDF and GHASP went on to state that the TCEQ did not use this proposed attainment demonstration SIP revision to implement control measures to reduce ozone concentrations to a level that is protective ofhuman health.
The commission appreciates the comments related to health effects ofozone and economic welfare. Thecommission is committed to working with area stakeholders to attain the 1997 eight-hour NAAQS, which is a health-based standard, as expeditiously as practicable to adequately protect public health in accordance with the EPA's 1997 eight-hour implementation rule, EPA guidance, and the FCAA. The primary NAAQS are those that the EPA determines are necessary, with an adequate margin ofsafety, to protect the public health, including sensitive members of the population such as children, the elderly, and 9 of53those with existing lung or cardiovascular conditions. It is well known that some air pollutants, including ozone, can aggravate existing respiratory diseases. The primary health concerns for ozone are effects to the lungs and respiratory system. Health effects from ozone generally can resolve quickly once an individual is no longer exposed to high levels. By demonstrating attainment ofthe 1997 eight-hour ozone standard in the HGB area, in accordance with the EPA's 1997 eight-hour implementation rule, the EPA's guidance, and the FCAA, the commission is ensuring that public health will be adequately protected.
Thecommission strives to protect ourstate's human and natural resources, including those in the HGB area, consistent with sustainable economic development. The commission is committed to attaining the 1997 eight-hour ozone standard as expeditiously as practicable in aU ofthe state's ozone nonattainment areas. The purpose ofthis plan is to demonstrate attainment ofthe 1997 eight-hour ozone NAAQS by June 15, 2019, in accordance with the EPA's guidance and FCAA requirements. By improving airquality in the HGB area, this plan will improvethe quality oflife for manyresidents ofthe HGBarea. The rules associated with this attainment demonstration SIP revision include achievable and cost-effective ozone emissions standards for sources in and around the HGB nonattainment area. An achievable and cost-effective level of control for a particular
source category depends on the current levels ofemissions, available control technologies for the source category, and othertechnical and economic factors that may be specific to a source or to a region. The commission determined the appropriate level of control for sources in the HGB nonattainment area considering all appropriate factors, including information obtained during the public comment period. Discussion regarding the level of control required on specific source categories is provided in the adopted rules associated with this attainmentdemonstration SIPrevision.
CONTROL STRATEGIESDISCUSSION HRVOC Emissions Capand Trade(HECT)Program· BCCA, the Coalition, LyondellBasell, TAB, TCC, Texas Petrochemicals, and TxOGA supported the TCEQ's proposed 25 percent reduction in the HECT program emissions allowance cap. AmericanAcry1 and Arkema supported efforts by the TCEQ to reduce the total HECT trading cap.
The commission appreciates the comments and will continue to work with area stakeholders to attain the 1997 eight-hourozone standard in the HGB area as expeditiously as practicable.
The EPA requested that the commission explain why the reductions cannot be implemented
sooner than the proposed 2015-2017 time frame. EDF and GHASP expressed support for reducing the HECT cap for Harris County in stepwise fashion by IO percent in 2014, followed by annual 5percent reductions through 2017.
The adopted rule revisions will reallocate the program in 2011 and implement an initial 10 percent reduction ofthe existing available HECT cap of 3,451.5 tons beginning with the 2014 calendar-year control period. The available cap will then be reduced in 5 percent increments at the startofeach calendar-year control period for 2015, 2016, and 2017. The full 25 percent cap reduction will have been in effect for one full calendar-year control period by January 1, 2018. While historical data demonstrate an overall surplus in the HRVOC cap, many sources were operating near their individual cap limits and thus may see a significant change in their HRVOC emissions. The cap reduction and reallocation may require some individual sites to install additional controls or otherwise modify their operations to reduce their HRVOC emissions. The step-down approach allows companies

10 of53time to install controls ifnecessary. Tbe commission bas made no changes in response to thesecomments.
BCCA and the Coalition commented that the reallocation of HRVOC allowances in the HECT program rulemaking included in the proposed attainment demonstration SIP revision is not required for purposes of providing ozone precursor reductions for the 1997 eight-hour ozone HGB SIP package. TAB and TxOGA commented that the proposed attainment demonstration SIP revision does not rely on the reallocation rulemaking. PL Propylene commented that the reallocation of HECT allowances is fair and necessary to protect the integrity ofthe proposed attainment demonstration SIPrevision.
Thecommission agrees witb BCCA, the Coalition, TAB, and TxOGA that the reallocation of HECT allowances is not required to model attainment of the HGB area for the 1997 eigbt-bour attainmentdemonstration SIP revision. The reallocation ofHRVOC allowances does not in itself include a mandatory reduction in the HRVOC cap in Harris County. However, following the initial allocation ofallowances, the TCEQ received comments that the allocation was not equitably distributed. Information from the first two years of monitoringdata supportsthe assertion ofan inequitable distribution ofallowances. A more equitable allocation ofallowances will stimulate the market, creating incentives for further reductions by industry regulated by the program. The commission therefore agrees with PL Propylene that revisions to the rule are anticipated to result in a more equitable approach. Because the change in allowance allocation methodology will create incentives for further reductions, it will contribute to the area's attainment of the NAAQS as expeditiously as practicable. The commission bas made no changes in response to these comments.
HSC proposed that the commission should discontinue the HECT program and set command and control emission limits for each emissionpoint.
The commission did not propose discontinuation ofthe HECT program. This comment is beyond the scope ofthis attainment demonstration SIP revision. The commission adopted the HECTprogram having determined it to bethe most efficient means by which to achieve cost-effective reductions ofHRVOC. The HECT program was approved by the EPA on September 6, 2006, and provides compliance flexibility while maximizing the efficiency of emission reductions through market forces. Tbe commission maintains that the HECT program is the most cost-effective means of achieving emissions reductions of HRVOC. Individual sources ofHRVOC emissions also must meet permit limits and any applicable limit is established by rule. The HECT program provides for additional decreases in HRVOC emissions limits above and beyond these basic requirements. Thecommission has made no changes in responseto thiscomment.
Mass Emissions Cap andTrade(MECT) Program The EPA requested clarification on the amendment to §I01.353(b) and why it does not require minor sources ofNOx submitting late ECT-3 fonns to obtain allowances from the market. The EPA commented that these minor sources ofNOx could increase the overall cap andjeopardize the attainment demonstration modeling for the HGB ozone nonattainmentarea. The MECT NOx cap is a product of the emission specifications ofChapter 117 and the submitted levels ofactivity from applicableexistingfacilities, about an 80 percent reduction from each existing facility's baseline. A new facility (i.e., a new or modified facility that is part of an administratively complete permit application received on or after January 2, 2001) tbat is subject to the MECT program cannot receive an allocation ofallowances, and the sitemustobtain allowances to coverthe new facility's total emission ofNOx.
Minor sources of NOx with applicable facilities that are not in the MECT program must meet tbe emission specifications ofChapter 117 on a unit-by-unit basis. A minor source of II of53NOx with facilities subject to the emission specifications of Chapter 117 must comply by installing controls, the use of emission reduction credits (ERCs), or the use of discreet emission reduction credits (DERCs). A minor source of NOx is subject to the MECT program once the site bas a collective uncontrolled design capacity to emit greater than or equal to 10 tons per year (tpy) NOx. If an existing facility at a minor source of NOx transitions from being a non-MECT facility to a MECT facility, it may receive allowance allocations based on the emission specifications ofChapter 117. Ifa minor source ofNOx submits a late Form ECT-3, Level of Activity Certification (ECT-3 form) but installed controls on an existing facility to comply with Chapter 117 prior to entering the MECT program, the site would undergo both the cost of installing the controls and the cost of purchasingthe entire amountofallowances needed to comply with the MECT program for each control period ifthe late ECT -3 form was not accepted. This action would penalize sites that choose to install controls on an existing facility and then become subject to the MECT program. Therefore, the commission is continuing to grant allowances for the portion of an existing facility's emissions at a minor source of NOx that were previously controlled through compliance with the Chapter 117 emission specifications. Ifan existing facility required additional allowances for compliance, the allowances would have to be purchased from the market. Although the existing facility's compliance mechanism transitions from direct compliance with the emission specifications to compliance with the MECT program, there is no actual growth in real emissions because the allowance is based
on actual level of activity and the emission specification the existing facility was already required to meet. Although granting these allowances to minorsources does slightly increase the MECT NOx cap,it does notinterferewith the attainmentdemonstration photochemical modelingforthe HGB area. When analyzing future growth in the attainment demonstration model, it is assumed that there is no trading because trading is highly unpredictable from fluctuations in needs and market conditions. Existing facilities subject to the MECT program are modeled at their allowance allocation amount and not allowed any growth. New facilities subject to the MECT program are modeled atzero (i.e., allocated zero allowances), because these facilities are required to obtain allowances from existing facilities through trading. With respect to the model, the sum of the MECT existing facilities and the MECT new facilities is the MECT NOx cap. With respect to actual emissions, the sum ofthe MECT existing facilities' and the MECT new facilities' actual NOx emissions is less than or equal to the MECTNOx cap.
New and existing facilities not in the MECT program are allowed growth using photochemical modeling values based on EPA-approved growth methodologies. For example, a facility entering late into the MECT program will be recategorized in the model to theallowance allocation amountwith zero growth,andthephotochemical modelingvalue based on an EPA-approved growth methodology will be discarded. Ifthe modeled MECT NOx cap were to increase, then that would result in decreases ofthe non-MECT modeled NOx emissions to which this growth was applied. The final result would actually be a net decrease in the total point source NOx emissions inventory in the model, ifthe model were to berunwith thenew numbers.
If an existing facility at a minor source of NOx is in the area source inventory, the allowances provided to thatfacility would still be applied to the total point source inventory modeled MECT NOx cap. However, the commission has decided not to decrease the area source inventory correspondingly at this time because the change would be insignificant. Historically, the increase in the MECT NOx cap due to approved late ECT-3 forms submitted by minor sources of NOx bas been insignificant. Since January 1, 2004, the commission approved 13 late ECT-3 forms that were due by June 30, 2001. These sites were allocated an average of 3.64 tons of allowances per site, or 0.01 tpd NOx. The collective total from the 13 sites is about 0.13 tpd. The total 2018 modeled baseline area source inventory and point source inventory NOx emissions are 42.04 tpd and 154.36 tpd, 12 of53respectively. Adjusting the modeled area source inventory for such an inconsequential decrease is an impractical use of resources and provides no benefit. Therefore, the commission bas chosen to model such changes conservatively and only include the increase in thepoint source MECTNOx cap. Thus,thecontinued acceptance oflate ECT-3 forms from existing facilities atminorsources of NOx, while slightly increasing the NOx cap, will not interfere with attainment demonstration photochemical modeling for the HGB area. The commission has made no changesin response tothis comment.
The HSC commented that the commission should discontinue the MECT program and set command and control emission limits for each emission point.
The commission did not propose discontinuation ofthe MECT program. This comment is beyond the scope ofthis attainment demonstration SIP revision. The commission adopted the MECT program having determined it to be the most efficient means to achieve costeffective reductions ofNOx. The MECT program was approved by the EPA and provides compliance flexibility while maximizing the efficiency of emission reductions through market forces. The commission maintains that the MECT program is the most costeffective means of achieving emissions reductions of NOx. Individual sources of NOx emissions also must meet permit limits and any applicable limit as established by rule. The MECT program provides for additional decreases in NOx emissions limits above and beyond these basic requirements. The commission bas made no changes in response to this comment.
OffsetLithographic PrintingRuleRevisions PIGC commented that the health benefit to the public of the proposed Chapter 115 offset lithographic printing rules is negligible because there are relatively few firms in the HGB area that will be affected by the proposed rules in Chapter 115. PIGC further commented that the printing industry is not amajor source ofemissions inthe HGB area.
The commission is aware that printing sources do not constitute a large proportion ofthe emissions in the HGB area. However, revisions to the 30 TAC Chapter 115: Control of Air Pollutionfrom Volatile Organic Compounds offset lithographic printing rules are necessary to fulfill FCAA reasonablyavailablecontrol technology (RACT) requirements.
In accordance with FCAA, §172(c)(1) and §182(b)(2), the state is required to include RACT for VOC emission sources addressed in a control technique guidelines (CTG) document issued between November 15, 1990, and the area's attainment date in the HGB Attainment Demonstration SIPRevision for the 1997 Eight-HourOzone Standard. The EPA published
a CTG document in lieu of national regulations for VOC emissions from Offset Lithographic Printing and Letterpress Printing in the October 5, 2006, issue ofthe Federal Register (71 FR 58745). The purpose ofthe offset lithographic printing rule revision is to implement RACT for this CTG emission source category. The commission has made no changes in response to this comment.
Identification ofMost Effective Ozone Control Strategies COH requested a list ofthe most effective control strategies for reducing regional ozone levels. COH also requested that the ozone reductions associated with each ofthese key strategies be included.

In general, it is necessary to reduce anthropogenic NOx and VOC precursors to achieve lower ozone levels in the atmosphere. In VOC-Iimited arid metropolitan areas with little vegetation and much anthropogenic NOx, VOC controls tend to be more effective for reducing ozone. In NOx-limited areas, such as the eastern half of Texas, that have
13 of53significant naturally occurring biogenic VOC, it is typically more effective to reduce anthropogenic NOx instead of VOC for the purposes of lowering ozone concentrations. However, the situation is more complex for industrial areas where HRVOC is common, such as the Houston Ship Channel. In such cases, both NOx and HRVOC reductions are needed. Numerical quantification ofozone reductions is very difficult because individual
areas of the HGB nonattainment area can be either NOx-limited or VOC-Iimited on any given day.
The commenter requested the ozone reductgions associated with each strategy. Because
ozone formation is a combination of non-linear chemical and photochemical reactions, a simple analysis ofthe effect of each strategy is not possible. Further, the commission bas not conducted an analysisofwhateach strategy bas contributed to ozone reduction because this exercisewould be resource intensive while not producing meaningful information upon which to base future plans.
At the March 25 and 26, 2008, stakeholder meetings, the TCEQ provided a list of initial potential control measures that was based on stafrs initial evaluation ofpossible measures to be considered in the RACM analysis. Any control measures suggested by stakeholders during the informal comment period were added to this list. All the measures included on the initial list and those suggested by stakeholders were evaluated in the RACM analysis provided in Appendix E: 

### ReasonablyAvailable Control Measure Analysis. However, the TCEQ must also consider other factors in addition to using modeling to estimate the ozone reduction benefits of potential control strategies. Examples of such other factors include technological and economic feasibility, the agency's legal authority, and time required for implementation. The most effective control measures atreducingozone maynotnecessarily be cost effective ortechnologically feasible. TheTCEQ must considerall these factorswhen determiningwhether a control measureshould beimplemented as RACM.
The attainment demonstration SIP revision contains sufficient reductions ofboth NOx and VOC precursors to demonstrate, in conjunction with the WoE analysis, attainment ofthe 1997 eight-hour o:zOne standard by 2018 in HGB. Thecommission has made no changes in response to thiscomment.
MobileSources EDF and GHASP stated that the commission should implement more stringent cut-points for use in the liM program.
In a previous rulemaking, Senate Bill 12: Low Income Repair Assistance, Retrofit, and Accelerated Vehicle Retirement Program (Rule Project No. 2007-026-114-EN), the commission requested public comment to whether a transition to final cut-points should be considered for the acceleration simulation mode (ASM) emissions inspections performed on gasoline-powered model year 1995 and oldervehicles. Due to the vehicle inspection failure rate of approximately 9 percent escalating to over 30 percent for this older group of vehicles, and the continuing diminishing fleet of older vehicles, the commission adopted amendments to 30 TAC Chapter 114: 

### Control of Air Pollutionfrom Motor Vehicles on December 5, 2007, with no action taken to implement final cut-points for ASM inspections. As the gasoline-powered model year 1995 and older vehicle fleet continues to diminish, down from 23 percent in 2007 to 12 percentin 2009, the reductions diminish from 0.36 tpd NOx and 0.30 tpd VOC in 2012, to 0.13 tpd NOx and 0.12 tpd VOC in 2018. Due to the issues identified as part ofRule ProjectNo. 2007-026-114-EN, thecommission basopted not to implement final cut-points for ASM inspections. Thecommission has made no change in response tothis comment.

14 of53EDF and GHASP recommended that the commission adopt a program to identify high-emitting vehicles.
A remote sensing program that identifies high-emitting vehicles has been part ofthe Texas Inspection and Maintenance State Implementation Plan since 1996. The program was implemented in the HGB area in 1998. The Texas Department ofPublic Safety (DPS), the agency that implements the liM program along with the commission, uses remote sensing technology to identify vehicles operating within the 1/M program areas that have a high probability of being high emitters. The remote sensing program focuses on identifying probable high-emitting vehicles that are registered within the subject counties but are not complying with periodic inspection requirements in the 11M program areas and probable high-emitting vehicles commuting from adjacent non-liM program counties. A motorist whose vehicle meets the high-emitter identification criteria is mailed a notification letter informing him that the vehicle has a high probability of being a high emitter. The notification letter informs the motorist that the vehicle is required to undergo a remote sensing vehicle emissions verification inspection thatcan be conducted atany DPS-certified safety·and emissions inspection station. In addition, the motorist is informed that if the vehiclefails theverification inspection, thevehicle is required tobe brought intocompliance with the 11M program requirements. Ifthe motorist fails to complywith therequest to have the vehicle undergo a verification inspection or bring the vehicle into compliance after failing a verification inspection, the motorist may be issued a citation with progressive penalties that may escalate to a maximum of$1,000 peroffense for the continuance ofnoncomplianceand thevehicle may bedenied re-registration.
The EPA suggested that the TCEQ include estimated time frames for initiation and completion of the candidate Transportation Control Measures (TCM) listed in Table I ofAppendix G.
The commission appreciates the comment and has updated Appendix G: Transportation Control Measures for the HGB AttainmentDemonstration SIPRevision for the 1997 EightHour Ozone Standard (Excerpt from Evaluation of Mobile Source Control Strategies for the Houston-Galveston-Brazoria State Implementation Plan), Prepared for HoustonGalveston Area Council, Prepared by ENVIRON International Corporation, Table 1: Projectswith Applicable Benefits to showbid acceptancedates and completion dates.
Emissions Inventory EDF and GHASP commented that the TCEQ should work with the EPA and the United States Coast Guard to better assess barge emissions and adopt appropriate control measures. Currently, Chapter 115 specifies control measures for barge loading, unloading, and degassing operations while barges are docked. While the TCEQ does not currently have rules specifying control requirements for barges duringtransit, theTCEQhas worked with the Coast Guard, the American Waterways Operators, and other groups to develop industry Best Management Practices for barge operations to reduce VOC emissions during transit and dock operations, as detailed in Chapter5: 

### Weight of Evidence, Section 5.4.3.10: 

### American Waterways Operators Tank Barge Emissions Best Management Practices of this attainmentdemonstration SIPrevision.
The point source inventory accounts for bargeemissions while docked. TheTCEQhas also initiated mobile source emissions inventory improvement research to account for barge VOC emissions while in transit. Research will build upon the EPA's recently published assessment of barge fugitive emissions entitled 

### Investigation ofFugitive Emissionsfrom Petrochemical Transport Barges Using Optical Remote Sensing (EPA/600/R-09/136), available at: http://cfpub.epa.gov/si/si public record Report.cfm?dirEntrvid=213705.

15 of53REASONABLY AVAILABLE CONTROL TECHNOLOGY (RACT), REASONABLY AVAILABLE CONTROLMEASURES (RACM) RACT, RACMAdequacy EDF and GHASP commented that the current attainment demonstration SIP revision fails to adopt all RACM and RACT as expeditiously as practicable. EDF and GHASP commented that the attainment demonstration SIP revision contains no additional RACT requirements for nonCTG major sources ofNOx and VOC emissions and only one additional RACT requirement for a CTG VOC emission source category (offset lithographic printing). EDF and GHASP also commented that the attainment demonstration SIP revision only contains one additional RACM requirement that will not result in actual emission reductions (Harris County HECT cap reduction).
The commission disagrees that the current attainment demonstration SIP revision fails to adopt all RACM and RACT as expeditiously as practicable. As described in the RACT analysis in Appendix D: 

### Reasonably Available Control Technology Analysis of this attainment demonstration SIP revision, the commission determined that all technologically and economically feasible controls are implemented. The commission's analysis demonstrates that the RACT requirements are being fulfilled in the HGB area by: (1) identifying all CTG source categories ofNOx and VOC emissions and submitting negative declarations for categories where there are no emission sources of these types within the HGB area; (2) identifying all non-CTG major sources of NOx and VOC emissions; (3) identifying the state regulation that implements orexceeds RACT for each applicable CTG
source category or non-CTG major emission source; and (4) describing the basis for concludingthatthese regulations fulfill RACT.
As described in the RACM analysis in Appendix E: 

### ReasonablyAvailable ControlMeasure Analysis of this attainment demonstration SIP revision, the commission evaluated all potential RACM identified to determine if all technologically and economically feasible control measures that would advance attainment ofthe ozone NAAQS were implemented. The commission used a two-step process to identify all potential RACM for stationary sources, including requesting stakeholder suggestions for potential RACM to evaluate during the SIP development process. The commission evaluated all identified potential stationary source RACM and determined that only one potential control measure, reducing the Harris County capunderthe HECTprogram,metthe criteria to be considered RACM. All other potential controlmeasures evaluated for both stationary and mobile sources were determined not to be RACM due to technological or economic feasibility, enforceability, adverse impacts, or ability of the measure to advance attainment of the NAAQS. The details ofthecommission'sdeterminations regardingmeasures determined not to be RACM are provided in the discussion sections and RACM tables included in Appendix E: 

### Reasonably Available Control Measure Analysis. The commission made no changes in response to this comment.
EDF and GHASP commented that the commission did not provide the reasoned justification required by the EPA for rejecting otherwise available RACT measures. EDF and GHASP stated that the commission did not adequately support the conclusion that additional RACT measures for major sources ofNOx and VOC emissions are not economically or technologically feasible. EDF and GHASP also stated that the commission did not adequately explain why the schedule to implement all RACM, including RACT, is the earliest feasible schedule based on the specific circumstances ofthe area. EDF and GHASP stated the commission must do more than simply assert that additional RACT measures for major sources of NOx and VOC emissions are unavailable. EDF and GHASP stated that since RACT is a subset of the broader RACM requirements, the commission's obligation to provide a reasonedjustification for the rejection of RACM applies equally to the rejection ofRACT.

16 of53The commission disagrees that the current attainment demonstration SIP revision does not provide a reasonedjustification for not adopting all RACT. The commenters are correct that the general discussion portion of the RACT analyses in Appendix D: Reasonably Available Control Technology Analysis the attainment demonstration SIP revision only summarizes the commission's conclusion that all RACT measuresfor major sources ofNOx and VOC emissions are being implemented. However, Appendix D: ReasonablyAvailable Control Technology Analysis, Table D-2: State Rules Addressing RACTRequirementsfor Major Emission Sources in the HGB Area of this attainment demonstration SIP revision identifies the state regulation that implements orexceeds RACT for each applicable major emission source category anddescribes the basis for concluding thatthese regulations fulfill RACT. Thecommission made no changes in responseto this comment.

RACT EDF and GHASP expressed support for RACT rules limiting the VOC content ofsolvents used by offset lithographic printingoperations and expandingthe rule applicability to include currently unregulated sources.
Thecommission appreciatesthesupport.
HSC commented on the statement in the preamble to the offset lithographic printing rule revision (Project No. 2008-0I9-I I5-EN) that the commission does not agree that applying RACT standards to future equipment installations is necessary to meet the mandates ofthe FCAA under §§I72(c)(I), I82(b)(2), and I82(t). HSC commented that the commission has stated publiclythat additional reductions are necessary to achieve the ozone standard. HSC suggested the commission implement RACT to reduce risks to human health and welfare and advance attainment ofthe ozone standard in the HGB area.
The statement referenced by the commenterwas included as part ofa discussion about the EPA's 2006 Offset Lithographic and Letterpress Printing CTG recommendations. Specifically, the EPA's CTGrecommends requiring control equipmentfirst installed before the effective date ofrules implementing the CTG to have an overall control efficiency of90 percent and control equipment first installed after the effective date ofrules implementing the CTG tohave an overall controlefficiency of95 percent. The commission disagrees with the EPA's CTG recommendation to correlate control device efficiency requirements with the first installation date of the control device regardless of where the equipment was installed. The commission contends imposing this policy may encourage the installation of older, less efficient equipment and may create potential backsliding issues. This policy could also create significant practical enforceability issues for commission investigators with regard to verifying the first installation date ofthe control equipment However, in response to comments received on the offset lithographic printing rule revision, the commission has removed this statementfrom therulepreamble. Additionally, as described in the RACT analysis in Appendix D: Reasonably Available Control TechnologyAnalysis ofthis attainment demonstration SIP revision, the commission determined that all technologically and economically feasible RACT controls are implemented. The commission's analysis demonstrates that the RACT requirements are being fulfilled in the HGB area by: (I) identifying all CTG source categories ofNOx and VOC emissions and submitting negative declarations for categories where there are no emission sources within the HGB area; (2) identifying all non-CTG major sources ofNOx and VOC emissions; (3) identifying the state regulation that implements or exceeds RACT for each applicable CTG source category or non-CTG major emission source; and (4) describingthe basis for concludingthatthese regulations fulfill RACT.

I 7of53The EPA requested confirmation that all NOx point sources in the HGB area with the potential to emit at least 25 tpy have been included in the list ofsources evaluated for RACT purposes.
As discussed in the RACT analysis provided in Appendix D: ReasonablyAvailable Control Technology Analysis of this attainment demonstration SIP revision, the commission reviewed the point source emissions inventory and Title V databases to identify all major
sources ofNOx emissions. All major NOx sources in the Title V database were included in the RACT analysis. Since the point source emissions inventory database reports actual emissions rather than potential to emit, the RACT analysis included sources that reported actual NOx emissions as low as 10 tpy to account for the difference between actual and potential emissions. Sites from the emissions inventorydatabase with emissions of 10 tpy or more ofNOx that were not identified in the Title V database and could not be verified as minorsources by othermeans arealso included in the RACT analysis.
The EPA requested confirmation that the level ofNOx control for affected sources in the HGB
area still represents RACTtoday.
As discussed in the RACT analysis provided in Appendix D: ReasonablyAvailable Control Technology Analysis of this attainment demonstration SIP revision, the commission maintains that under the current state rules, the HGB area is subject to some ofthe most stringent NOx emission control requirementsin the country and for manysourcecategories the existing rules are more stringent than recommended RACT standards for those categories. In the final approval notice for the revised HGB one-hour ozone attainment demonstration SIPpublished in the September6, 2006, issue ofthe FederalRegister(71 FR 52676), the EPA noted that the HGB NOx rules in Chapter 117 were previouslydetermined to meet the FCAA RACT requirements. The commission maintains that the level ofNOx controlthroughtheChapter 117 rules andtheNOx MECTprogram still representRACT.

The EPA commented that RACT should be federally enforceable and requested additional explanation as to why it is appropriate to use New Source Review (NSR) permit conditions to implement RACT for the glass manufacturing facility identified in the HGB area. The EPA also requested a copy oftheNSRpermit.
ThecurrentNOx rules in Chapter 117 do notcontain a RACT limit for glass furnaces in the HGB area. There were no glass furnaces in the point source emissions inventoryyear used during the HGB one-hour ozone attainment demonstration SIP revision; therefore, the commission had no reason to establish a RACT limit for this category in the HGB area during that SIP revision. The glass furnace at the Longhorn Glass Corporation facility began operation after the baseline inventory year that was used for the one-hour SIP revision. During the RACT analysis for this attainment demonstration SIP revision for the 1997 eight-hour ozone NAAQS, the glass furnace at this facility was identified in the inventory as an Alternative Control Techniques (ACT) category. However, the glass furnace located at the facility is equipment with oxy-tiring and is limited to 1.48 pounds (lb) ofNOx perton ofglass by the site's NSR permit. The level ofNOx control already installed at the facility already meets what the TCEQ considers to be the top end controls for glass furnaces, and additional NOx control is not possible at this facility. This is consistent with the EPA's ACT documentAlternative Control Techniques Document-NOx Emissionsfrom Glass Manufacturing, which describes oxy-firing as the most effective NOx control technique. Furthermore,thereareno otherglass furnaces in the HGBarea. Therefore, the TCEQdetermined thatestablishing a NOx RACT rule for theglass furnace sourcecategory was not necessary for fulfilling RACT for the HGB 1997 eight-hour ozone standard attainment demonstration because additional controls werenot necessary orpossible in this specificsituation.
This conclusion is supported by the guidance provided by the EPA in the RACT guidance documentRACTQs & As-ReasonablyAvailable Control Technology (RACT): Questions and 18 of53Answers, issued May 18, 2006. The following is the question and response in that guidance document regarding situations where states determine that additional controls are not necessary beyond whatwas required for theone-hourozone standard. Question: "What should a State do ifit concludes thatfor a specific source or source category no additional controls are necessary beyond what was required by theRACT analysis underthe 1-hourstandard?"
EPA's response: "Where a State concludes that the no control is required beyond what was required for purposes of the 1-hour NAAQS, the State should submit its analysis justifying such a conclusion as part ofits RACT SIP."
Additional controls are not required for fulfilling RACT for the glass furnace source category in the HGB area. The NOx emission rate limit established for this furnace has remained unchanged since the permitwas first issued in 2000. Ifthepermitholder (facility) desired to increase their emissions or the emission factor of 1.48 lb of NOx, the permit holder would be required to modify their permit and demonstrate that best available control technology (BACT) is applied at the higher rate. Because the facility has operated with this emission limit in place since initial startup of the unit, such a modification is unlikely. Therefore, the TCEQdoes notexpectthatthis emission limitwill be relaxed in the future. The executive director's staff will· continue to track the Longhorn Glass Corporation permit. Ifany changes occur in the permit that interfere with RACT, the executive director will initiate a future SIP revision, if necessary, for the commission's consideration to ensure that that NOx RACT is maintained for the HGB area. The TCEQ will providetheEPAwith a copy oftherequested permitinformation.

EDF and GHASP stated that the commission failed to provide adequate justification for not including the EPA's 2006 Offset Lithographic and Letterpress Printing CTG recommendation to require use ofan add-on control device with 95 percentefficiency. EDF and GHASP rejected the commission's explanation that existing rules are equivalent since the state only requires add-on control devices with 90 percentefficiency.
The commission maintains that the overall VOC control level in the adopted Chapter 115, Subchapter E, Division 4 is equivalent to or more stringent than the EPA's 2006 Offset Lithographic and Letterpress Printing CTG recommendations and sufficient to fulfill RACT for offset lithographic printing operations in the HGB area. The commission must balance arbitrarily implementing the 2006 CTG recommendations with the potential for backsliding, enforceability considerations, and the possible impacts to sources that have already compliedwith theexisting rules.
The commission also notes thatin several instances, the adopted Chapter 115 content limits
are more stringent than the EPA's 2006 CTG recommendations. The 2006 CTG recommends limiting the VOC content of cleaning solutions used in offset lithographic printing operations to 70 percent VOC by weight in conjunction with work practice standards. The adopted Chapter 115 rules retain the more stringent cleaning solution content limit of70 percent VOC by volume in conjunction with work practice standards. Assuming theVOC in thecleaning solventused is kerosene, which is theVOC referenced in the 2006 CTG, the adopted Chapter 115 content limit of70 percent VOC by volume for cleaning solutions is equivalent to 66 percent VOC by weight. The EPA's 2006 CTG also recommends limiting the fountain solution contentto 5percentalcohol substitutes orless by weight and no alcohol in thefountain solution. To prevent potential backslidingfor sources already required to comply with these state regulations, the adopted Chapter 115 rules retain the more stringent fountain solution content limit of3 percent alcohol substitutes or less byweightand no alcohol in the fountain solution.

19of53The commassaon maintains that the adopted Chapter 115 rules for heatset offset lithographic presses are at least as stringent as the EPA's 2006 CTG-recommended controls. The EPA's CTG recommends an add-on air pollution control device be required
on each individual heatset offset lithographic press with the uncontrolled potential to emit 25 tpyofVOC or more from the dryer. Therules in Chapter 115, SubchapterE, Division 4 require control devices, with a control efficiency ofat least 90 percent, to be installed on heatset offset lithographic presses on a property in the HGB area with total uncontrolled VOC emissions ofat least 25 tpy, which includes VOC emissions from ink oils evaporated by the press dryer and VOC in fountain and cleaning solutions. In Table 5-1: 

### ModelPlant Product Use and Baseline (Uncontrolled) Volatile Organic Compounds (Average Tons Per Year) of the 1993 draft Offset Lithographic Printing CTG, the EPA estimates that 26 percent ofthe total uncontrolled VOC emissions from heatset offset lithographic printing operations are emitted from the press dryer. Based on EPA's assumption, an individual heatset press located on a property with total uncontrolled VOC emissions of25 tpy would emit less than 7 tpy of VOC from the press dryer. Therefore, the Chapter 115 offset lithographic printing rules are effectively more stringent than the EPA's 2006 CTG RACT recommendations with regard to the applicability threshold for this control requirement. Additionally, the EPA's 2006 CTG recommended exempting heatset presses used for book printing and heatset presses with a maximum web width of22 inches or less from the addon control device requirements. The existing Chapter 115 regulations do not exempt these
sources from the control requirements, and the commission has not adopted these exemptions into the revised rule.
The EPA's CTG recommends requarmg control equipment first installed before the effective date of rules implementing the CTG to have an overall control efficiency of 90 percent and control equipment first installed after the effective date ofrules implementing the CTG to have an overall control efficiency of95 percent. Thecommission disagrees with the EPA's CTG recommendation to correlate control device efficiency requirements with the first installation date of the control device regardless of where the equipment was installed. The commission contends imposing this policy may encourage the installation of older, less efficient equipment because facilities purchasing used equipment would be held to a less stringent standard and may create potential backsliding issues. This policy could also create significant practical enforceability issues for commission investigators with regard to verifying the first installation dateofthecontrolequipment. Regardless ofthe first installation date ofthe device, the EPA recommends providing the alternative option to reduce the control device outlet concentration to 20 parts per million by volume (ppmv) as hexane on a drybasis to accommodate situations where theinlet VOC concentration is too low to demonstrate the 90 or 95 percent control efficiency. The Chapter 115 rules provide affected owners or operators of a heatset offset lithographic printing press the option to operate a control device to reduce VOC emissions from the press dryer exhaust vent by 90 percent by weight or maintain a maximum dryer exhaust outlet VOC concentration of20 ppmv. The Chapter 115 alternative concentration limit is substantially preferable because it encourages VOC emission reductions without requiring add-on controls and implementing the EPA's recommended approach would penalize operations that were able to achieve the 20 ppmv limit without the installation ofexpensive and unnecessary add-on controldevices.
Based on this analysis, the commission determined that the adopted Chapter 115 rules for offset lithographic printing operations provide an overall VOC control level that is at least equivalent to the 2006 CTG recommendations and are more effective and enforceable. Therefore, the revised Chapter 115, Subchapter E, Division 4 rules are sufficient to fulfill RACT for offset lithographic printing operations. The commission made no change in response to thecomment.

20 of53EDF and GHASP commented that the commission failed to provide an adequatejustification for rejecting all ofthe EPA's work practice recommendations in the II VOC CTG documents issued from 2006 through 2008. EDF and GHASP stated that rejecting the CTG-recommended work practices based on the unverified assumption that facilities are implementing similar practices fails to demonstrate the kind ofreasonable explanation required ofagencies and is unsupportable giventhe significantprogress needed to restore healthy airto thecitizens ofthe HGB area. The commission provides a negative declaration for the FlatWood Paneling Coatings CTG, Fiberglass Boat Manufacturing Materials CTG, and Auto and Light-Duty TruckAssembly Coatings CTG source categories. The commission bas determined that no sources meeting the applicability criteria recommended in these CTG documents are located in the HGB
area. The commission is not making a determination at this time whether the recommendations in the following CTG documents represent RACT for Texas: Industrial Cleaning Solvents, Miscellaneous Industrial Adhesives, Large Appliance Coatings, Metal Furniture Coatings, Miscellaneous Metaland Plastic Parts Coatings, Flexible PackagingPrinting Materials, and Paper, Film, and Foil Coatings. Theexecutive directorwill proceed with RACT analyses of these CTG documents and initiate a future SIP revision and rulemaking for the commission's consideration, ifnecessary, to submit RACT determinations to the EPA in a timely manner.
In response to comments received regarding the offset lithographic printing rule revisions, the commission is revising the rule to include the CTG-recommended work practice requirementsfor offset lithographic printingoperations.
The EPA commented that the commission did not propose a RACT determination for the Industrial Cleaning Solvents CTG or the Miscellaneous Industrial Adhesives CTG. The EPA commented that for the HGB area to meet the requirements for RACT (40 Code of Federal Regulations (CFR) §51.912), the commission will need to complete RACT determinations and take appropriate action for these two CTG categories. The EPA indicated approval ofthe VOC RACT update would only be considered for those CTG categories that have been thoroughly addressed.
As noted in the EPA's comment, the commission did not make a determination whetherthe Industrial Cleaning Solvents and Miscellaneous Industrial Adhesives CTG recommendations represent RACT for Texas. The commission maintains the EPA substantially underestimated the scope and potential impact of these CTG recommendations, especially the impacts to small businesses. The commission is conducting research to determinethe quantityofaffected sources in theHGB area andplans to provide small business outreach to engage stakeholders that could be potentially impacted by the EPA's suggested control measures. The executive director will proceed with RACT analyses ofthese CTG documents and initiate a future SIP revision and rulemakingfor the commission's consideration, ifnecessary, to submit RACT determinations to the EPA in a timely manner.
The EPA commented that the commission did not propose a RACT determination for the Large Appliance Coatings, Metal Furniture Coatings, and Miscellaneous Metal and Plastic Parts Coatings CTG. The EPA commented that for the HGB area to meet the requirements for RACT (40 CFR §51.912), the commission will need to complete RACT determinations and take appropriate action for these three CTG categories. The EPA indicated approval of the VOC RACT update would only be considered for those CTG categories that have been thoroughly addressed. The EPA acknowledged that it has not yet responded to the commission's request for clarification on potential backsliding issues in the Large Appliance Coatings, Metal Furniture Coatings, and Miscellaneous Metal and Plastic Parts Coatings CTG documents; specifically, the commission requested clarification on implementing CTG recommendations for specialty 21 of53coatings that are less stringent than the EPA's

### gener~l-use coating.RACT

### recommenda~ions from the 1970s. The EPA identified two options for movmg forward wtth the RACT analysts ofthese CTG recommendations: (1) implement only those CTG-recommended specialty coating content limits that are more stringent than existing state limits; or (2) relax the existing coating content limits consistent with the new CTG recommendations and provide additional analysis to demonstrate compliance with the non-interference provisions under FCAA, §II0(1).
As noted by the EPA, the commission did not make a RACT determination for the Large Appliance Coatings, Metal Furniture Coatings, and Miscellaneous Metal and Plastic Parts Coatings CTG recommendations. The EPA's CTG documents for these emission source categories did not contain sufficient information for the commission to determine if the CTG recommendations constituteRACT for Texas. On December 8, 2008, the commission requested written clarification on why the coating content limits in these CTG recommendations were less stringent than the previously issued RACT recommendations for the same source categories. While the EPA bas not yet formally responded to· the December 2008 letter, the commission appreciates the EPA's suggestions regarding the issues raised by the commission. The executive director will proceed with RACT analyses of these CTG documents based on the guidance provided in the EPA's comments and initiate a future SIP revision and rulemaking for the commission's consideration, if necessary, to submitRACT determinations to the EPA in a timely manner.
The EPA commented that the commission has chosen not to adopt the recommended work practices in the 2006 Flat Wood Paneling Coatings CTG. The EPA added that these work practice requirements provide reasonable, cost-effective controls and are an important way to reduce emissions. The EPA stated that to meet RACT requirements, the commission should either adopt rules implementingthe work practicerequirements orprovide analysis demonstrating thatthe requirements are satisfied by existingrules.
At the September 23, 2009, agenda for proposal of this attainment demonstration SIP revision, the commission determined that no sources in the HGBarea meet theapplicability criteria in the 2006 Flat Wood Paneling Coatings CTG. The commission provided a negative declaration for the FlatWood Paneling Coatings CTG sourcecategory in Chapter 4: 

### Control Strategies and Required Elements, Section 4.2: 

### Existing Control Measures, Section 4.4.3.1: 

### CTGDocuments ThatAreNotApplicableto theHGBAreaofthis attainment demonstration SIP revision; however, some ofthe language used in the RACT analysis in Appendix D: 

### Reasonably Available Control Technology Analysis of this attainment demonstration SIP revision did not clearly reflect this determination. Appendix D: 

### ReasonablyAvailable Control TechnologyAnalysis bas been revised to clearly indicate that the commission is providing a negative declaration for this emission source category with regardto RACTfor the HGBarea.
The EPA commented that the co.mmission needs to address the VOC RACT requirements for the Fiberglass Boat Manufacturing Materials CTG source category. The EPA disagreed with the commission's interpretation ofthe EPA's 1988 guidance for determining alternative applicability thresholds for RACT ("Issues Relating to VOC Regulation Cutpoints, Deficiencies, and Deviations, Clarificationto Appendix D ofNovember 24, 1987 FederalRegister" issued May 25, 1988) since the calculation was not specifically based on emission sources in the HGB area. The EPA commented that the Fiberglass Boat Manufacturing Materials CTG-recommended controls
are cost-effective, and RACT for this emission source category should be addressed.
The 2008 Fiberglass Boat Manufacturing Materials CTG document did not identify any sources in Texas that would be subject to the CTG-recommended controls. However, as of the September23, 2009, agenda for proposalofthis attainmentdemonstration SIPrevision, the commission could not make a definitive negative declaration for this source category. Since that time the commission bas conducted extensive additional review of sources identified in the point source emissions inventory, Title V permits, and central registry 22 of53databases. No sources meeting the applicability criteria recommended in the CTG document were identified in the HGB area. Therefore, the commission provides a negative declaration for this emission sourcecategorywith regardto RACT for theHGB area.
The EPA commented that the commission has chosen not to adopt the recommended work practices in the 2007 Flexible Package Printing CTG and the 2007 Paper, Film, and Foil Coatings CTG. The EPA added that these work practice requirements provide reasonable, cost-effective controls and are an important way to reduce emissions. The EPA stated that to meet RACT requirements, the commission should either adopt rules implementing the work practice requirements or provide analysis demonstrating that the requirements are satisfied by existing rules.
In response to EPA's comments, the commission has decided to reevaluate the RACT determinations for the Flexible Packaging Printing Materials and thePaper, Film, and Foil Coatings CTG recommendations. The executive director will proceed with RACT analyses of these CTG documents based on the guidance provided in the EPA's comments and initiate a future SIP revision and rulemaking for the commission's consideration, if necessary, to submit RACT determinationsto theEPA in a timely manner.
EDF and GHASP disagreed with the statement on Page D-3 of the proposed attainment demonstration SIPrevision that the "EPA has issued CTG documents defining RACT for existing facilities and ACT documents that describe available control technologies but do not define presumptive RACT levels." EDF and GHASP stated that the EPA's CTG establish presumptive levels ofcontrol that demonstrate RACT.
The commission agrees that the EPA's CTG documents establish presumptive RACT. In the statement referenced by the commenters, the commission generally describes both the EPA's CTG and ACT documents. As quoted in the comment from EDF and GHASP, the commission indicates thattheEPA bas issued CTGdocuments defining RACT. In the same sentence, the commission indicates that the EPA has also issued ACT documents that describe available control technologies but do not define presumptive RACT levels. The commission bas revised the statement in Appendix D: Reasonably Available Control Technology Analysis of this attainment demonstration SIP revision to avoid any future confusion resulting from sentence structure. The revised statement reads, "The EPA has issued CTGdocuments definingRACT for existingfacilities. The EPA has also issued ACT documents that describe available control technologies but do not define presumptive RACT levels."

EDF and GHASP commented that the commission rejected nearly all of the EPA's RACT recommendations in the 11 CTG documents issued from 2006 to 2008 without adequately demonstrating that the alternative strategies relied on to fulfill RACT requirements for these emission source categories will achieve equivalentemission reductions.
The commission disagrees with the commenters' statement that the commission rejected nearly all ofthe 11 CTG documents. The commission is making a negative declaration for three ofthe CTG source categories: the Flat Wood Paneling Coatings CTG; Fiberglass Boat Manufacturing Materials CTG; and Auto and Light-Duty Truck Assembly Coatings CTG source categories. The commission has determined that no sources meeting the applicability criteria recommended in these CTG documents are located in the HGB area. States are allowed to provide negative declarations for such situations. Furthermore, the commission did not propose RACT determinations for five ofthe 11 CTG categories. As discussed elsewhere in this response to comments, the commission determined additional research was needed on two CTG categories (Industrial Cleaning Solvents and Miscellaneous Industrial Adhesives), and the EPA had not yet responded to the commission's request for clarification on three other CTG categories (Large Appliance Coatings, Metal Furniture Coatings, and Miscellaneous Metal and Plastic Parts Coatings). 23 of53Thecommission determined thatCTG recommendations for the offset lithographic printing industry do represent RACT, and the commission is adopting rule amendments to implement additional RACT requirements for this category. The commission proposed that additional controls were not necessary for two of the 11 CTG categories (Flexible Packaging Printing Materials and Paper, Film, and Foil Coatings); however, as discussed elsewhere in this response to comments, the commission is withdrawing RACT determinationsfor these two categories.
The CTGdocuments for which thecommission is not making a RACT determination atthis time include: Industrial Cleaning Solvents; Miscellaneous Industrial Adhesives; Large Appliance Coatings; Metal Furniture Coatings; Miscellaneous Metal and Plastic Parts Coatings; Flexible Packaging Printing Materials; and Paper, Film, and Foil Coatings. The executive directorwill proceed with RACT analyses ofthese CTG documents and initiate a future SIP revision and rulemaking for the commission's consideration, if necessary, to submitRACT determinationsto theEPA in a timely manner. Regarding the EDF and GHASP comments about equivalent reductions, the commission maintains that the overall VOC control level in the adopted Chapter 115, Subchapter E, Division 4rules is equivalent to or more stringent than the EPA's 2006 Offset Lithographic and Letterpress Printing CTG recommendations and sufficient to fulfill RACT for offset lithographic printing operations. Additional discussion regarding the overall control level ofthe adopted rules for the offset lithographic printing industry is provided elsewhere in this response to comments.
RACM The EPA commented that the proposed reduction and reallocation ofthe Harris County HRVOC cap does not require HRVOC levels to be reduced below currently reported levels. The EPA stated that the current 25 percent reduction in the HECT cap would still be higher than reported emissions and would allow for growth and allowances for upset conditions. The EPA added that the 25 percent cap reduction would allow HRVOC emission increases at HECT-applicable facilities compared to the highest annual actual HECT emissions. The EPA suggested that the commission consider as part of the RACM analysis whether reductions in actual HRVOC emissionscould accelerate attainment.

EDF and GHASP stated that they see no reason to delay additional cap reductions beyond the proposed 25 percent at this time. The commenters stated that to ensure that the area is meeting the FCAA requirement to implement all RACM as expeditiously as practicable, the commission must lowerthe cap to a meaningful level that will produce actual emissions reductions in the near term, or provide a logical, reasoned explanation as to why doing so is not feasible. EDF and GHASP statedthat sincethis HECTcapreduction is based onthe fact that emissions from capped
sources during the first two years ofthe program only averaged approximately 56 percent ofthe total allocated allowances, the commission should notclaimthat a 25 percent reduction in the cap would result in any actual emissions reductions. They added that since the reduction is only in allowable emissions there will not be any improvement in actual air quality. EDF and GHASP commented that a HECT cap reduction closer to 50 percent is necessary in order to achieve any actual reductions and airquality improvement.
The commission agrees that the HECT reallocation and cap reduction does not require mandatory reductions ofHRVOC emissions from program participants. The purpose of the rulemaking is to reallocate the program for a more equitable distribution ofallowances based on actual monitoring data and reduce the HRVOC cap in Harris County by 25 percent. A more equitable allocation of allowances will stimulate the market, creating incentives for further reductions in the industry regulated by the program.

24 of53Photochemical modeling analysis demonstrates that the proposed HECT rule revision, which includes a reallocation and 25 percent reduction ofthe HRVOC emissions in Harris County, would advance attainment ofthe 1997 eight-hour ozone NAAQS by reducing the future 2018 ozone design values at all HGB area monitors. For the three monitoring sites with 2018 projected eight-hour ozone design values greater than the NAAQS, Deer Park (DRPK; CAMS 35), Bayland Park (BAYP; CAMS 53) and the non-regulatory, industry sponsored Wallisville (WALV; CAMS 617) monitor, the average decrease in the projected DV18s was 0.13 ppb. The DRPK; CAMS 35 monitor's DV18 was the highest in the HECT sensitivity modeling. The HECT sensitivity modelingdecreased the DRPK; CAMS 35 DV1s from 86.49 ppb to 86.36 ppb.
The commission agrees with EDF and GHASP that HRVOC monitoring data reported for 2006 through 2008 indicates that the total actual emissions from sources in the HECT program have been approximately SO percent ofthe total current HRVOC cap. Because the HRVOC rules in Chapter US, Subchapter H, Division 1 and Division 2 require emissions from maintenance, startup, and shutdown activities and emissions events be included in the HECT program, the total surplus observed in the two years that the programhas been active cannot be removed. Therefore, a bufferin thecapis still needed to account for the inherent variability of HRVOC emissions associated with these activities. The25 percent reduction in the Harris County HRVOC cap allows for a sufficient bufferto protect against the inherent variability in HRVOC emissions, and according to photochemical modeling, the average 2018 future cap design value is within EPA's range forWoEdiscussion.

EDF and GHASP suggested a number ofadditional general VOC control measures that should be considered sources ofadditional emission reductions. EDF and GHASP commented that current rules for condensatetanks in §ll5.ll2(a)(3)only require a control device capable ofa 90 percent reduction. EDF and GHASP suggested additional reductions in flash emissions from hydrocarbon storagetanks, by requiring installation ofa control device capable ofa 95 percent or 98 percent removal efficiency for tanks with cumulative, uncontrolled emissions equal to or greater than 20 tpy. The commenters cited Colorado and Wyoming requirements as sources for these suggested storage tank control measures. EDF and GHASP suggested a number ofother general VOC control measures that should be considered sources of additional emission reductions, including: requiring the use of low-bleed control devices on all new and existing pneumatic devices used in oil and gas operations; requiring all pneumatic pumpsto route gas vent lines to a combustion device; requiring VOC controls on glycol dehydrators located at oil and gas exploration and production operations, natural gas compressor stations, drip stations or gas processing plants with actual uncontrolled VOC emissions of IS tpy or more; requiring natural gas operators to reduce VOC emissions during well completions or work-overs by the use of specified practices generally referred to as green completions; and requiring VOC controls for natural gas-fired reciprocating internal combustionengines rated I00 horsepower or greater.
The commission disagrees that the suggested RACM should be considered as potential
sources of additional emission reductions. Based on photochemical modeling sensitivity matrix analyses, thecommission determined that reductions in general VOC emissions (i.e., non-HRVOC emissions) would not advance attainment ofthe HGB area. The 2018 futureyear matrix modeling sensitivity runs indicate that even substantial reductions in general VOC emissions will not have a significant enough impact on ozone reduction to be considered as RACM. The two regulatory monitors that still exceed the eight-hour ozone NAAQS in the 2018 future base case, DRPK; CAMS 35 and BAYP; CAMS 53, are insensitive to general VOC reductions. Approximately 130 tpd ofgeneral VOC reductions would be needed to reduce ozone at the DRPK; CAMS 35 monitor by 1 ppb. Approximately 230 tpd ofgeneral VOC reductions would be needed to reduce ozone at the BAYP; CAMS 53 monitor by 1 ppb. Given the magnitude ofVOC reductions needed to affect the ozone concentrations, and the lack of availability of strategies that could accomplish these magnitudes, the commission has concluded that general VOC reduction 25 of53control measures would not advance attainment and were not RACM because even large reductions ofgeneraiVOC emissions would only result in a small ozone reduction benefit in the HGB area. Additional information on the photochemical modeling sensitivity runs is provided in Chapter 3: Photochemical Modeling of this attainment demonstration SIP revision. Additionally, the commission notes that the Colorado and Wyoming regulations and permitting requirements referenced by the commenters only apply to new or modified
sources. Tbe control requirements in §115.112(a) apply to existing and new sources and resultin actualVOC reductions from existingsources.
EDF and GHASP suggested resetting the NOx cap at a reduced level to account for improvements in NOx control technology and to reflect the beneficial effects ofenergy efficiency andrenewable energy measuresthat are increasingly being implemented.
The commission disagrees that the suggested control measure should be implemented. The commission performed a thorough evaluation ofadditional NOx control measures as part of the RACM analysis and determined that additional NOx controls were not RACM due to technological and economic factors. Additional detail regarding theNOx RACM analysis is provided in Appendix E: ReasonablyAvailable ControlMeasuresAnalysisofthis attainment demonstration SIP revision. In addition, as discussed in Section 5.4.3.5: Energy Efficiency andRenewableEnergy (EEIRE) Measures ofthis attainmentdemonstration SIPrevision, the complex nature of the electrical grid makes accurately quantifying emission reductions from EEIRE projects difficult. Any NOx emission reductions resulting from EE/RE programs cannot be explicitly determined because local efficiency efforts may not result in local emissions reductions or may be offset by increased demand in electricity. Therefore, the commission determined that the suggested measures are not RACM because the emission reduction benefitis not quantifiable.
Kaneka cited a portion ofthe RACM analysis in Appendix E: ReasonablyAvailable Control Measure Analysis of the proposed attainment demonstration SIP revision, describing the practicality issues identified with revising NOx allowances under the MECT program because allowance streams have been traded and relied upon for compliance with the program. Kaneka concluded that if it is impractical to nullify MECT trades then it is also impractical to nullify HECT trades that have also been relied upon for compliance with the program.
The commission maintains that reallocation associated with reducing the Harris County HECT program cap is RACM. After the initial HECT program allocation, due to stakeholder comments and information from the first two years of monitoring data supporting the assertion that the program was not equitably distributed, the commission committed to reallocating the HECT program as soon as sufficient actual monitored HRVOC emissions data were available. A more equitable allocation of allowances will stimulatethe market, creating incentives for further reductions in theindustryregulated by theprogram. Thecommission acknowledges thatpracticality is one oftheEPA's evaluation criterion considered during the state's RACM analysis. In the portion of the RACM analysis referenced by thecommenter, thecommission also acknowledges practicalityissues associated with revising MECT program NOx allocations. However, as discussed at length in Appendix E: Reasonably Available Control Measure Analysis, Section 4.2.1: Mass Emission Cap and Trade (MECT) Program and Chapter 117 NOx Rules RACM of this proposed attainment demonstration SIP revision, the commission concluded that further NOx reductions through the MECT program did not constitute RACM on the basis of economic and technological feasibility, not practicality. Therefore, the commission disagrees with the commenter's conclusion that revising the HECT program should not be considered RACM based on the commission's RACM determination regarding revising the MECTprogram.
The commission agrees that the nullification issue should be addressed. The rules have been revised to allow sites that purchased allowances stream the potential to apply 26 of53allowances from the streamto the calculation ofuncontrolled emissions as actual emissions. Revised §101.394(a)(1) allows sites holding stream trades to calculate their uncontrolled emissions as the greateroftheir actual average emissions oftheirtwo highest emission years from 2006 through 2009 orthe sum oftheiroriginal existing HECT HRVOC allowance and the amount ofthe allowance stream in tons. In the event that a site's actual two high year emissions is less than the sum of its original existing HECT HRVOC allowance and the amount ofthe allowance stream in tons, the difference shall be added to the uncontrolled emissions as actual emissions. Thepurchase ofan allowance stream also allowed some sites to operate with higher emissions during the baseline emissions period. Sites that took advantage ofallowance streams would therefore realize the benefit ofthe higher emissions through theuncontrolled emissions-based reallocation methodology.
Flare TaskForceInitiative The EPA commented that reductions in industrial emissions would be most effective in advancing attainment. The EPA also expressed support for the commission's Flare Task Force initiative and expressed hope that it will result in future reductions ofindustrial emissions in the southeast quadrant ofHouston, including industry around the Houston Ship Channel. The EPA suggested that additional monitoring and requirements for flares would aid in improving the emission inventory and reduce ozoneprecursoremissions.
As described in the RACM analysis in Appendix E: ReasonablyAvailable ControlMeasure Analysis of this attainment demonstration SIP revision, the commission evaluated all identified potential stationary source control measures, including measures to reduce industrial emissions. The commission appreciates the EPA's support for the Flare Task Force initiative. As noted in Chapter 6: Ongoing and Future Initiatives, Section 6.2.1: Flare Task Force of this attainment demonstration SIP revision and elsewhere in this response to comments, the agency-wide Flare Task Force is evaluating the impact offlare emissions on Texas airquality and assessing the adequacy ofexisting flare regulations. The commission may consider additional control measures for flares in a future SIP revision as a resultofits ongoing efforts to evaluateflares in Texas.
EDF and GHASP commented that the proposed attainment demonstration SIP revision states that flares represent approximately 45 percent ofthe total NOx emissions from unregulated sources, and the commission's justification for not including control measures for these significant emissions was legally insufficient. EDF and GHASP commented that the current attainment demonstration SIP revision acknowledges that flares contribute an unknown amount ofHRVOC especially during emissions events but does not contain any additional provisions that would result in more accurate HRVOC emissions data. EDF and GHASP suggested requiring enhanced monitoring and reporting of flare emissions and suggested establishing NOx and HRVOC emissions limits for flares. Additionally, the commenters requested that the commission undertake a thorough analysis of controls for flares and include flare regulation in the current attainment demonstration SIP revision.
The commission acknowledges that flare NOx emissions represent a significant percent of the currently exempt sources; however, the actual NOx emissions from flares was approximately 5.6 tpd based on 2006 emissions inventory data. The external combustion nature of flares makes post-combustion NOx pollution control technology infeasible, and thecommission is unawareofanylow-NOx flare burnerdesigns. The commission considers the lack of available control technology to be a legally sufficient justification for determining a potential control measure is not RACM because a key aspect ofthe EPA's definition of RACM is that the control measure must be technologically feasible. Any reduction in NOx emissions from flares could only be made by a reduction in flaring. As noted in Chapter 6: OngoingandFutureInitiatives, Section 6.2.1: Flare Task Force ofthis attainment demonstration SIP revision and elsewhere in this response to comments, the agency-wide Flare Task Force is evaluating the impact of flare emissions on Texas air

27 of53. . nare regulations. F\are

## minimizati~n is a quality and assessing the adequacy of.n.1stmg

. 'm\l.ation

### ma~ reduce

### NOx em\ss\OUS at Part ofthat evaluation. However, whl\e nare

### ml~I · 

### NO em'tssious at a\teruative \ · sponding mcrease m x the flare, it could also resu t m a

### c:o~re . ry before tbe commission can determine control equipment. Further evaluatiOn IS nec:essa whether flare minimizationis a viableNOx controlmeasure.
Rcgilrding the suggestions for enhanced -monitoring, reporting, and HRVOC limits for nares, the commission has already established enhanced monitoring through the HRVOC rules in Chapter 115, Subchapter H, Division 1 for all eight counties in the HGB area, and flares arean applicable sourcecategory fortheHECTprogram in HarrisCounty. As noted in Section 6.2.1: 

### Flare Task Force of this attainment demonstration SIP revision and elsewhere in this response to comments, the agency-wide Flare Task Force is evaluating the impact offlare emissions on Texas air quality and assessing the adequacy ofexisting Dare regulations. The commission may consider additional control measures for flares in a future SIPrevision as a resultofits ongoingefforts to evaluate Dares in Texas.
The EPA commented that since HECT sources were subject to monitoring requirements, any unreported HRVOC emissions could only come from unmonitored sources or incomplete combustion offlares and that because unmonitored sources are small, the most likely source of the emissions was flares. The EPA commented that the TCEQ model sensitivity analyses where increased flare emissions were substituted for the Potential Source Contribution Function (PSCF)-based emission reconciliation yielded improved ozone model performance and that this, along with many other scientific studies, supports the conclusion that flare emissions are underestimated. The EPA noted that the TCEQ is in the process ofstudying flare operations and is considering the option ofrequiring more monitoring and oversight offlare operations in the future.
The TCEQ agrees that flares are a potential source ofunder-reported HRVOC emissions and is currently conducting research to investigate this issue. Additional information concerning the TCEQ's Flare Task Force and upcoming Dare studies is contained in Chapter6: 

### OngoingandFutureInitiatives.
PHOTOCHEMICALMODELING Supportfor AttainmentModeling andWeightofEvidence (WoE)Analyses BCCA and the Coalition submitted similar sets ofdetailed comments totaling over 50 pages that
were strongly supportive ofthe proposed attainment demonstration SIP revision. BCCA and the Coalition ran independent modeling scenarios that paralleled those presented in the proposed attainment demonstration SIP revision. They stated that "TCEQ adhered to EPA's modeling guidance assiduously," and described the demonstration as "exceeding requirements" and going "well beyond standard EPA methodology."
BCCA and the Coalition were complimentary ofthe ongoing public participation that the TCEQ facilitated in the modeling process, with specific mention ofthe monthly technical meetings held in the HGB area, along with the regular data file updates that were made to the TCEQ Web site and file transfer protocol (FTP) sites. BCCA and the Coalition referenced the extensive emissions, meteorological, and air quality datasets that are available from both the Texas Air Quality Study 2000 (TexAQS 2000) and TexAQS II studies, characterizing them as the most extensive and intensive databases ever assembled for regulatory modeling, far exceeding what has typically beenused in 1997 eight-hour ozone SIPrevisions elsewhere in the United States.
BCCA and the Coalition noted the large number offederal, state, local, academic, research, and private organizations involved in the various measurements and analyses required for the HGB attainment demonstration SIP revision modeling efforts. Supportive comments were made about the refined treatment ofthe lateral boundary condition inputs for Comprehensive AirModel with Extension (CAMx), the specialized meteorological inputs for modeling the HGB area with Fifth
28 of53Generation Meteorological Model (MM5), and the extensive performance evaluation conducted
on the output files from both CAMx and MM5. The model performance evaluation was independently verified by BCCA and the Coalitionusing the Modeling Analysis and Performance Software (MAPS) tools, which were originally developed by Alpine/CARA Geophysics, Inc.
BCCA and the Coalition commented that the WoE portion of the proposed attainment demonstration SIP revision is robust and also provided additional corroborative analyses. A URS Corporation analysis was cited that showed the annual number ofhigh ozone days declining from 2003-2009 even when looking solely at those days when weather conditions were conducive to ozone formation. Additional analyses showed a gradual decline from 1990-1998 in the ratio of high-ozone days to ozone-conducive days, followed by a significant drop in that ratio from 2004- 2007. BCCA and the Coalition cited considerable decreases in ambient concentrations of ethylene and propylene from industrial sources in the Houston Ship Channel area since 1995.
BCCA and the Coalition cited University ofNorth Carolina (UNC) research indicating that "the TCEQ's 2018 attainment results are, more likely than not, conservative

..." and that "the standard EPA attainment paradigm followed by TCEQ leads to a significant degree of conservatism" at the BAYP; CAMS 53, DRPK; CAMS 35, WALV; CAMS 617, and Houston Swiss and Monroe (HSMA; CAMS 406), monitors. UNC concluded that ifnon-typical ozone days are filtered out ofthe base-case modeling, the 2018 projected future design value (DVF) for these monitors would all be at 84 ppb or below. BCCA and the Coalition compared the EPA's recommended attainment test with eight alternatives and concluded that more conservative future design values were obtained by using TCEQ's custom approach based on 2007 EPA modeling guidance in lieu ofthe EPA's Modeled Attainment Test Software (MATS), which yields slightly lower values at most monitors on most episode days. BCCA and the Coalitionperformed source apportionment modeling on both the base and future-case scenarios and concluded that no single
source category or geographic region appears to dominate future ozone formation in the HGB
area.
BCCA and the Coalition commented that "TCEQ's weight ofevidence determination provides a thorough and up-to-date analysis ofambient ozone and precursor levels and trends, all ofwhich support the conclusion that the region will attain the 1997 ozone standard by the deadline." Additional analyses were provided that showed improving trends in air quality since 2002, with apparent acceleration since 2006. BCCA and the Coalition referenced declines in ambient concentrations ofbothNOx and HRVOC precursors, which are attributed to over $2 billion worth ofcontrol technologies installed by industries inthe HGB area since 2001.
BCCA and the Coalition expressed support for efforts by the TCEQ, described in Chapter 6: Ongoing and Future Initiatives to continue improving the scientific basis ofthe SIP modeling efforts for the HGB area. They recommended that the TCEQ pay specific attention to the following areas for potential improvement: (l) radical sources and atmospheric chemistry; (2) emissions inventory improvements; (3) quantification of emissions control sensitivity; (4) quantification of uncertainty; (5) ensemble modeling; (6) pragmatic two-ozone SIP control paradigm; (7) intercontinental transport of air pollution; (8) forge more scientific methods for attainment modeling; and (9) extended MM5/CAMx model evaluation across full 36/12/4/2 km grid scales.
Thecommission concurs with theoverallconclusion drawnby BCCAand theCoalition that both the photochemical modeling and WoE analyses are quiterobust in demonstrating that the HGB area will attain the 1997 eight-hour ozone standard by2019. Thecommission also
concurs that ongoing efforts should continue to improve the areas ofemissions estimation, meteorological modeling, and chemical processing mechanisms. The commission will continue to work with all interested stakeholders to improve the scientific basis of the photochemical modeling and WoE analyses that will be included in future HGB area SIP revisions.

29 of53Weight ofEvidence(WoE) CAIT, EDF, the EPA, GRASP, KIDS, SEED, and one individual commented that the WoE analysis did not account for the effects offavorable meteorological conditions on reducing the 2007-2009 ozone design values to below 85 ppb for HGB area monitors. The EPA stated that favorable meteorological conditions may have played a greater role in reducing the ozone concentrations than the reduced emissions ofozone precursors. The EPA cited 5-10 ppb drops in
ozone levels over the past two years from other metropolitan areas within Region 6. The EPA claimed that these decreases are an indication that the meteorological factors affecting the HGB
area also affected other Region 6 areas, and that these meteorological factors caused the ozone reductions. The EPA argued that the meteorological conditions during the 2005 and 2006 modeled ozone episodes are more conducive to ozone formation than the 2007-2009 conditions leading to the current design values. The EPA also contended that higher than average wind speeds occurred in both 2007 and 2008, leadingto lower ozone concentrations. COH requested a quantification ofthe impacts offavorable meteorology on monitored ozone levels over the past three years. CAIT, KIDS, SEED, and one individual mention an unusually rainy and cool ozone season during 2007 and an unusually windy ozone season in 2009.
The commission agrees that meteorological factors have played a small role in the recently observed ozone trends but disagrees that the meteorological factors are the primary reason for decreasing ozone. Analyses show that ozone trends are stilldecreasing in theHGBarea, even when theeffects ofmeteorology have been accounted for.
The commission disagrees with the EPA that meteorological conditions in Houston during 2006 through 2009 have been unfavorable for high ozone, and therefore the decline in ozone concentrations is not due to local emission reductions. The EPA bases its position on a finding from an analysis by Sather and Snyder, which shows that higher wind speeds occurred more frequently during 2008 than in 2000 through 2007. Figure 1: WindData fromHoustonA/dineshows the graph ofinterest.

Hourly Resultant Wind Speed Profile (mph)

82 84 86 88 90 92 94 96 98 

### oo 02 04 06 

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# m Meen I

Figure 1: WindData from Houston Aldine (Source: The data are from June through August, 0500 to 1900 local standard time (LST), with 65 percent minimum data capture. Winds of greater than 10 miles per hour (mph)
were more frequent during 2008 than any year since 1998. This figure is copied from Sather and Snyder, Region 6 "State ofthe Ozone" Reportfor 2008, presented at the Southeast Texas Photochemical Modeling Technical Committee (SETPMTC) meeting, Apri128, 2009.)
The EPA, and Sather and Snyder, assert that the higher winds in 2008 are the primary
cause oflower ozone in 2008. As they have noted, the frequency ofhigh winds in 2008 is 30 of53comparable to the frequency observed in 1998. The maximum 4th-high eight-hour ozone concentrations in 1998 ranged from 90 to 117 ppb at regulatory monitors throughout Houston, but the maximum 4th-high eight-hour ozone concentrations in 2008 ranged from 68 to 83 ppb at Houston regulatory monitors. This represents a 29 percent decrease in maximum eight-hourozone from 1998 to 2008. Since the frequency ofhigh winds is similar in 1998 and 2008, the frequency ofhigh winds cannot explain the difference between ozone concentrationsduringthose two years.
The commission contends thatfour extensive analyses ofmeteorological conditions (each of which includes more thanjustthe frequency ofhigh winds) indicate meteorological factors cannot explain the recent decrease in ozone. In addition, an analysis ofthe frequency of wind speed and direction will show that the period ofhigh winds in 2008 noted by Sather and Snyder occurred at a time ofyear when high ozone usually does not occur because of thedirection ofthewind flow at thattime ofyear. Itwill also showthatthewind conditions were more suitable for high ozone formation in August and September of2008 and 2009 than in 2000 and 2004, but the numberofozone exceedance days was far lower in 2008 and 2009. Chapter 5: Weight of Evidence ofthis attainment demonstration SIP revision contains an analysis from the University ofTexas at Austin (UT-Austin) that shows the ozone trends adjusted for meteorology. Those trends show thatozone levels through 2007 aredecreasing even with meteorological influences removed from the trends. Much ofthe work from UTAustin was based upon a variation ofthe analysis technique developed by Camalier, Cox, and Dolwick, which is the technique recommended by the EPA for removing the influences ofmeteorology from trend data. UT-Austin's analysis shows that when the portion ofthe
ozone variation associated with meteorological factors is removed from the observed ozone trend, the residual trend is still downward. Thepresence ofa strong downward trend after the removal ofmeteorological effects strongly suggests that the overall downward trend is related to factors otherthan meteorology.
A second analysis of meteorologically adjusted ozone trends can be found on the EPA's Web site: www.epa.gov/airtrends/weather/region06.pdf. TheEPA trends areshown in Figure 2: MeteorologicallyAdjusted Ozone Trends in the HGBAreafrom 1997through 2008, that illustrates the observed seasonal average ozone trend as well as the seasonal average ozone trend adjusted for weather. The ozone trend adjusted for weather represents the expected
ozone levels for typical weather conditions. According to the EPA analysis, the downward trend in Houston's ozone is unrelated to meteorological variations, beginning in 2002 and continuingthrough the end ofthe analysisperiod in 2008.

31 of53

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Figure 2: Meteorologically Adjusted Ozone Trends in the HGB Area from 1997 through 2008 (Source: EPA)
URS Corporation performed a third analysis ofthe effects ofmeteorology on ozone trends, which is included in comments received from the Coalition. A presentation that discusses URS Corporation's analysis can be found at: http://www.tceg.state.tx.us/assets/public/implementation/air/am/committees/pmt set/200712 12/20071212-setpmtc-hgb ozone trend.pdf. In the analysis, the author used the Classification and Regression Tree (CART) method, a multivariate statistical analysis technique, to classify ozone season days according to meteorological conditions, and whether those conditions are conducive to high ozone in Houston. URS Corporation's analysis calculated trends of the number of ozone-conducive days per year. Figure 3: Number of Ozone ConduciveDaysandNumber of Ozone Conducive Days with Ozone Greater Than 84ppb shows that the number of ozone-conducive days in 2007, 2008, and 2009 is similar to or greater than previous years, indicating that the past three ozone seasons have beenjustas conducive to high ozone formation as previous years. Since 2005, there appear to be more ozone-conducive days than average, but fewer eight-hour ozone exceedance days. Although 2005 had the largest number of ozone-conducive days since 1990, there
were fewer exceedance days in 2005 than during previous years with a lower number of ozone-conducive days, such as 1995, 2000, or2003.

32 of53

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Figure 3: Number ofOzone-Conducive Days and Number ofOzone-Conducive Days with Ozone GreaterThan 84 ppb (Source: URS Corporation)
A fourth analysis is presented as a response to the comment by EDF and GHASP about evaluatingthe trends in forecasted high ozone days. A possible surrogatefor the numberof ozone-conducive days during each ozone season is the number ofTCEQ-forecasted eighthour ozone exceedance days. Figure 4: 

### Forecasted and Actual Eight-Hour Ozone Exceedance Days (1997 NAAQS) in the HGB Area shows that the number of forecasted eight-hour ozone exceedance days is typically greater than the number ofactual eight-hour
ozone exceedances to avoid missing potentially high ozone days. To adjust the forecasted eight-hour ozone exceedances to compensate for the bias, a bias-adjusted forecast was developed by accounting for the average rates offalse positives (predicted exceedances that did not occur) and false negatives (predicted non-exceedances on days with high ozone). The average percent offalse negative days was added to the number offorecasted ozone exceedance days, and the average percent offalse positive days was subtracted. The biasadjusted forecasted ozone exceedance days approximately match the actual number of eight-hour ozone exceedance days, with the exception of2004 and 2008. In 2004, the biasadjusted ozone exceedance forecast was much lower than the actual number ofeight-hour
ozone exceedance days. However, in 2008, the bias-adjusted forecast ofozone exceedance days was much higher than the actual number of eight-hour ozone exceedance days, indicating decreases due to factors otherthan meteorology. There are uncertainties in this analysis because meteorologists at the TCEQ adjust their forecast techniques as they learn
more about which conditions are most conducive to ozone formation, accumulation, and transport in Houston. In other words, the criteria used for developing forecasts in 2000 may have differed somewhat from the criteria used in 2008. The results, however, are consistent with the three previous analyses, in that the peak number of ozone-conducive days in recent years appears to be in 2005, with the number decreasing slightly in 2006 to 2007. The number offorecasted ozone days in 2008 approximately matched the number in 2006, buttherewere abouthalfas manyactualexceedance days in 2008 asin 2006.

33 of53

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### 2000 2001 2002 2003 2004 2005 2006 2007 2008

Figure4: Forecasted and Actual Eight-Hour Ozone Exceedance Days (1997 NAAQS) in the HGBArea
Those four analyses ofthe effects ofinter-annual meteorological variations on ozone trends all imply that meteorological factors alone cannot explain the decrease in ozone concentrations in the Houston area. The commission has also analyzed the frequency ofwind speeds and directions by month and by year to show in greater detail the wind data that the EPA had originally cited in its comment. The winds in the HGB area were examined for each month ofthe ozone season from 2000 through 2009 to determine if higher wind speeds in 2008 and 2009 caused decreases in ozone concentrations. Daytime wind speeds were grouped into six levels, and the frequencies ofthose levels were examined by wind direction for each month from May to September, which represents the peak ofthe ozone season in the HGB area. Figure 5: Frequency of Morning WindDirection and WindSpeedby Month in the HGBArea for 2000, 2004, 2008, and 2009 compares years with similar winds and shows the number ofeighthour ozone exceedances thatoccurred in each month (1997 NAAQS). Winds from 0 to 90 degrees are from the north to east, and, as shown in Chapter 5: Weight of Evidence ofthis attainmentdemonstration SIPrevision, winds from thatdirection typically representhigher background ozone concentrations, as well as winds that can interact with the bay breeze and Gulf breeze to create stagnant conditions (Darby, 2005; Pakalapati et al., 2008; Sullivan, 2009; Ngan and Byun, 2008; Rappenglueck et al., 2008. For full references of these citations, see Chapter 5: Weight of Evidence of this attainment demonstration SIP revision). Winds from 90 to 225 degrees are from the east to southwest and represent cleaner air blowing in from the GulfofMexico (Sullivan, 2009; Rappenglueck et al., 2008. For full references ofthese citations, see Chapter 5: Weight of Evidence ofthis attainment demonstration SIP revision). Those east to southwest winds accentuate the bay and Gulf breezes rather than opposing them (Darby, 2005; Banta et al., 2005. For full references of these citations, see Chapter 5: Weight of Evidence ofthis attainment demonstration SIP revision). Findings from previous studies have indicated thatlow winds are more favorable for high ozone, whereas high winds are less favorable. Findings also show that northerly winds are more favorable for high ozone in Houston, and that southerly winds are less favorable.
34 of53TheTCEQ'swind analysis found that:

• Wind speeds in May 2000 and May 2004 were higher than those observed in May 2008 and May 2009, but the number of eight-hour ozone exceedance days was higher in 2000 compared to 2008 and2009. May 2000 and 2004 wereless conducive to ozone formation based upon wind speeds but bad more exceedances than May 2008 and 2009.

• May 2009 also bad more winds from the north to northeast direction, which typically indicates higher background ozone, but bad only three exceedance days. May 2009 was more conducive based upon wind direction yet bad fewer exceedances than May 2000 or2004.

• June 2008 and 2009 bad higher wind speeds than those observed in June of 2000 and 2004; however, winds in Junearemainly out ofthe south,which brings in clean air from the Gulf of Mexico. There were only three exceedance days in June of 2000, five in June of2005, and two in bothJune2008 and June2009. For all years, June was dominated by southerly winds, which are not conducive to ozone formation. The low number of exceedances each year reflects bow unfavorable southerly winds are to ozone exceedances; therefore, the slightly greater frequency ofhigh winds in June2008 was unlikely to affect the number ofexceedances in that month.

• July winds were very similar in 2000 and 2009, buttherewere only two exceedance days in July 2009 comparedto 10 exceedancedays in July 2000.

• Winds in August 2008 were slower than those observed in August 2000, yet August 2008 bad one exceedance day compared to 15 in 2000. August 2008 was more conducive to high ozone than August 2000, based upon wind speeds, but bad far fewer exceedances.

• September 2009 bad slightly lower winds in the northeast direction compared to September 2000 and 2004, but only three exceedance days compared to 10 in September2000 and 13 in September 2004. September2009 was more conducive to high ozone, but bad farfewer exceedances than September2000 or2004.
In summary, Figure 5: Frequency of Morning WindDirection and WindSpeedby Month in theHGBArea for2000, 2004, 2008, and2009 shows that thewind speed and direction were actually more conducive to ozone formation during the peak ofthe ozone season in August and September in 2008 and 2009 than in 2000 and 2004, but 2000 and 2004 had far more exceedances than 2008 and 2009. The greater frequency of high winds in 2008 noted by Sather and Snyder occurred during June, when winds were southerly, and therefore not conduciveto high ozone, duringallfour years.
Evidence provided in the proposed attainment demonstration SIP revision, along with additional analyses presented in this response to comments, show that favorable meteorology is not adequate to explain the decreases in ozone observed in 2007, 2008, and 2009. Because the last stepdown ofNOxemissions in theMECT program occurred in 2007, the commission contends that these substantial reductions are a primary cause of ozone reductions, not weather patterns. Evidence presented in Chapter 5: Weight of Evidence of this attainment demonstration SIP revision shows that decreases in ozone precursor emissions played a significant role in the recentdecreases in ozone.

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Figure5: FrequencyofMorningWindDirection andWind Speed byMonth in theHGBArea for 2000, 2004, 2008, and2009

36 of53EDF, the EPA, and GHASP commented that the WoE analysis did not account for the effects of the recent economic downturn on the 2007-2009 ozone design values being at or below 84 ppb for HGB area monitors. Specifically, the EPA noted that "industry representatives have commented

...that theiremissions have been lower inthe last few years (starting in 2007) due to economic influences and when demand improves it is likely theiremissions will increase overthe levels in 2007-2009." The EPA further stated that "after the economy gains strength and emissions likely increase

... it seems unlikely that the area will continue to monitor attainment." The EPA emphasized that some ofthe monitors currently at or close to an 84 ppb design value
are located within or downwind of industrial areas and would then likely register higher ozone levels when economic demand increases in the future. COH requested a quantification ofthe emission inventory changes and approximate ozone reductions that have occurred over the past few years due to the economic downturn. COH requested a list ofactions necessary to make these emission changespermanent and enforceable.
The commission disagrees with these comments. Detailed analysis ofactual economic data from the HGB area,Texas, and the refming industry along theGulfCoastdoes not support these conjectures based on anecdotalevidence and speculation. Indeed, there is no evidence of an economic downturn in Texas, the HGB area, or the petrochemical industry specifically,priorto early2009. None ofthecommentersprovided any specific data to back uptheassertions madein theircomments. Though the national economy entered a recession beginning in the fourth quarter of2007, both Texas and the HGB area continued to experience robust economic expansion during 2007 and 2008. Only in early 2009 did eitherTexas orthe HGB area begin to exhibitflat or slightly reduced economic activity. While Texas Gross Domestic Product (GDP) increased 7.3 percent in nominal terms from 2006 to 2007 (see Figure 6: Gross Domestic Product of Texas) and 6.5 percent from 2007 to 2008, the economy ofthe Houston-Sugarland-Baytown
area grew even faster, at 8.4 percent and 7.4 percent over those years, respectively (see Bureau ofEconomicAnalysis, Regional Economic Accounts: www.bea.gov/regional/gsp/ and GDPby Metropolitan Area: www.bea.gov/regional/gdpmetroD. Though these figures are not corrected for inflation, inflation was exceptionally low over this period. HoustonSugarland-Baytown is the definition of the HGB metropolitan area used by the United StatesDepartmentofCommerce.

.

37 of53$billions $1,400

$1,200

$1,000

$800

$600

$400

$200

$- 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 Source: Bureau of EconomicAnalysis, U.S. Department ofCommerce http://www.bea.govlregional/gspl Figure 6: Gross Domestic ProductofTexas
Another measure ofeconomic activity for the Houston-Sugarland-Baytown metro area, the business cycle index computed by the Federal Reserve Bank of Dallas (www.dallasfed.org/data/datalhoucoini.htm), exhibits a downward trend beginning only in early 2009 (Figure 7: MetroAreaBusiness Cycle Index, Houston-Sugar/and-Baytown). The index, which incorporates measures ofemployment, real wages, and retail commerce, grew 5.6 percentfrom December2006 to December2007, and 2.5 percentfrom December2007 to December 2008. Through September 2009, the index is down -2.7 percent from the end of 2008. This index, available through the first threequartersof2009, shows thatduring each oftheyears 2007,2008, and 2009 to date, the HGB area generated greatereconomic activity than in any previous yearon record, exceeding an index value of245 in every month. Prior to 2007, the index never exceeded thatvalue. Despite this burgeoningeconomic activity, the HGB area continued to exhibit reductions in both precursor emissions and resultant ozone overthose threeyears.

38 of53October 1980= 100 300

275

250

225

200

175

150 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08 Jan-09 Source: Federal Resene Bank ofCallas Figure7: MetroArea Business Cycle Index, Houston-Sugarland-Baytown
While the overall economies ofTexas and the HGB area were not impacted by theeconomic downturn until early 2009, industries linked to petrochemicals and refining, which are key to HGB area air quality, also failed to exhibit the claimed downward trend (see Figure 8: Gross Domestic Product of SelectedPetroleum RelatedIndustries). From 2006 to 2007, the most recent annual period for which sub-industry GDP data are available, oil and gas extraction increased 7.6 percent. Similarpatterns existfor othersegments ofthe petroleum industry over that period. Manufacturing of chemicals grew 9.9 percent, while manufacturing ofplastics and rubber products increased 2.7 percent. Only manufacturing ofpetroleum andcoal productsdeclined (ata rate of-1.9 percent)from 2006 to 2007.

39 of53$billions $80

$70

$60

$50
$40

$20

$10 -+-Oiland gas extraction {left axis) ....,.__Petroleumand coal products mfg {right axis) -Chemical mfg {right axis) -+-Plastics and rubber products mfg {right axis) $billions $40
$35

$30

$25
$20

$15

$10
$5

$- $- 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
Source: Bureau of EcooomicAnalysis, U.S. Department ofCommerce http://wwN.bea.gollregional/gspl Figure 8: GrossDomestic ProductofSelectedPetroleum Related Industries
While more recent data on GDP trends in the petrochemical andrefining industries are not yet available, other recent information on activity in those industries corroborates these findings. The Energy Information Administration of the United States Department of Energy reportsrefining activity alongthe GulfCoast, termed Petroleum Administration for Defense District (PADD) 3, which includes the HGB area (tonto.eia.doe.gov/dnav/pet/pet sum sndw deus r30 w.htm). As evident in Figure 9: Weekly GulfCoast (PADD 3) Crude Oil Inputs to Refineries, reported weekly inputs are highly variable. A 13-week, or roughly quarterly, moving average is superimposed on the weekly data to smooth out some ofthisvariability. Thatmeasure reveals the seasonal cycles in the industry, as refineries ramp up production for periods ofhigh product demand. Although inputs to refineries appear to be on a slight downward trend since 2007, they have actually been increasing since early 2009, though this is likely a cyclical phenomenon. In fact, neither high nor low values of the quarterly average since 2007 have strayed beyond the highest or lowest values observed over the previous decade indicating tbe industry as a whole has neithergrown norshrunkmarkedly.
A quadratic fit to the weekly data reveals a very slight long-term downward trend in the refining industry, beginning around 2004. Since 2004, PADD 3 inputs to refineries bave generally dropped, at a rate of about -0.7 percent per year, even when hurricane-affected periods in 2005 (Katrina,Rita) and 2008 (Ike) areexcluded.

40 of537,000

# , 6,000

5,000

4,000

EIAreports inputs by Petroleum Adminislration lorDefense District(PADD). PADD 3 includes refining I I i t ;

# ~am~ I I 

### \. I 

# v Ike

operations 3,000**,..:__---~--------------~~~~~~~~-----~** 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009**~~'** rce· u.S. Oe:pt at**~ergy.** t:ner!:l} offJr l'\"'tior AdPw hll1 · do.ela doe.gol.!dna\ Jel/hist**·.~.3-t.w** him
Figure9: Weekly GulfCoast(PADD 3) CrudeOilInputs to Refineries
This may suggest factors other than an economic downturn in 2007 or 2008 were influencing the industry. Average weekly inputs to refineries in 2007 were 7.35 million barrels, 1.4 percent above the average ofthe previous year and nearly as high as in 2004, when they averaged 7.37 million barrelsperweek. Although inputs to refineries in 2008 fell about 3 percent aftersix weeks ofhurricane-affecteddatawere removed, they werebackon trend again by 2009, dropping-0.6 percent.
An additional perspective on trends in the petrochemical industry is provided in Figure 10: 

### Weekly Percent Utilization ofRefinery Operable Capacity, PADD 3, which summarizes utilization of available refining capacity, also reported by the Energy Information Administration of the United States Department of Energy (tonto.eia.doe.gov/dnav/petlhist/wpuleus3w.htm). Capacity utilization, like inputs to refineries, is highly variable from week to week but is clearly on a long-term downward trend, having peaked in 1998 at 100.5 percent of operable capacity. Since then, despite considerable seasonal variation, it has fallen in most years as evident from the quadratic regression fitted to the series. When considered on an annualized basis to smooth outshortterm fluctuations, average capacity utilization decreased -0.7 percent from 2006 to 2007,

- 4.3 percent from 2007 to 2008, and -1.1 percent from 2008 to 2009. The decade-long duration of this downward trend corroborates the earlier conclusion that the petroleum refining industry may likely be experiencingphenomena unrelated to the national recession that began in 2007. That recession, though severe in many areas of the country, is not apparent within the refining industry and was likely not the primary determinant of refining activity in PADD 3.

41 of53100%

95

90

85

80

75

70

65

60 Reported weekly capacity**utiliza~on** (light olive) Quadratic regressionfitto weeklydata (dark olive)



## '-u Katrina Ike

1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 20042005 2006 2007 2008 2009

Source: U.S. Dept of Energy, EnergyInformation Admin. Figure 10: WeeklyPercentUtilization ofRefinery OperableCapacity,PADD 3
The EPA commented that the WoE analysis excluded a discussion ofhow recent emission trends correlate with ozone-monitoring trends. The EPA mentioned that the modeling and attainment guidance recommends inclusion ofsuch an analysis for WoE discussions. The EPA stated that future expected emission trends should also be included in this analysis for the area, non-road, on-road, and point major source categories.
As the EPA correctly states on pages 102 and 103 ofits modeling guidance, "a simpler (and
more uncertain) way to qualitatively assess progress toward attainment is to examine recently observed air quality and emissions trends." Refer to Guidance on the Use of Models and Other Analysesfor DemonstratingAttainment of Air Quality Goalsfor Ozone, PM1.5, andRegionalHaze, EPA-454/B-07-002, April2007. An emission trend analysis is less sophisticated, less certain, and less quantitativethan other analyses, and for thatreason, no emission trend data were included in the original proposal. The commission contends that ambient NOx and VOC data are a more reliable indicator for historical emission trends than the emissions inventory data, which have more and larger sources oferror associated with estimating industrial emissions. Chapter 5: Weight ofEvidence of this attainment demonstration SIP revision contains extensive historical ozone precursor trend analyses that are based upon monitoring data. Those ozone precursor concentration trends are not subjectto the underestimates observed in the industrialemissions inventories. However, the EPA's request for a trend analysis for past and future emissions by major
source category can be satisfied with the emission estimates thatareincluded in Chapter2: EmissionsInventories, Section 2.7: EmissionsSummary ofthe Houston-Galveston-Brazoria Reasonable FurtherProgress (RFP) StateImplementationPlanRevision forthe 1997 EightHour Ozone Standard (ProjectNo. 2009-018-SIP-NR), which is being adopted concurrently with this attainment demonstration SIP revision. For more detail on the development of those emission inventories, see the RFP SIP revision, along with its accompanying appendices. Figure 11: RFPNOxEmission Trendsfrom 2002 to 2018 and Figure 12: RFP
42 of53VOCEmission Trendsfrom 2002 to 2018 presentbarchartsummaries ofthecontrolledNOx andVOC emissions comparedwith uncontrolled emission totals.



### HGB 8-County RFP Controlled Ozone Season Weekday NOx emissions

1400 ..,.----------------------, 1200 i;' 1000 "CC 

# l 800 600 

# , c 0 

# - 400 200 0 

### 2002 2008 2011 2014 2017 2018 

## o reductions •onroad
• nonroad 

### illarea •point

Figure 11: RFPNOx EmissionTrendsfrom 2002 to 2018 Figure 11: RFPNOx Emission Trendsfrom 2002 to -2018 includes each source category, based upon weekday emissions within the eight-county HGB area. The reductions shown hererepresent the mass ofweekdayNOx emissions eliminatedbycontrolseachyear.



### 1400 1200 i;' 1000 "CC



### .... 800 

## 8. 

# , 600 c 0 

### 400 

# - 200 0 

### HGB 8-County RFP Controlled Ozone Season Weekday VOC emissions



## o reductions •onroad •nonroad
•area •point



### 2002 2008 2011 2014 2017 2018

Figure 12: RFPVOC Emission Trends from 2002 to 2018 Figure 12: RFP VOC Emission Trendsfrom 2002 to 2018 includes each source category, based upon weekday emissions within the eight-county HGB area. The reductions shown here representthemass ofweekdayVOCemissions eliminated bycontrolseachyear. EDF, GHASP, HSC, and LWV Houston opposed reliance on WoE to augment photochemical modeling. EDF and GHASP recommended that additional control measures be included to model below 84 ppb. EDF and GHASP claimed that the following three WoE arguments are insufficient to overcome the absence ofmodeling lower than 84 ppb: (l) model under-prediction 43 of53ofreductions; (2) recent trend of decreasing ozone concentrations; and (3) voluntary and other control measuresthatmaynotbe implemented.
The commission disagrees with this comment. The EPA's modeling and analysis guidance recommends the use of WoE analyses to complement attainment demonstrations. The EPA's 

### Guidance on the Use of Models and OtherAnalysesfor DemonstratingAttainment of Air Quality Goals for Ozone, PM2.5, and Regional Haze, Section 2.3: 

### What Does A Recommended SupplementalAnalysis/Weight OfEvidence Determination Consist Of? --An Overview says that states "should always perform complementary analyses of air quality, emissions and meteorological data, and consider modeling outputs other than the results of the attainmenttest. Such analyses are instrumental in guiding the conduct ofan airquality modeling application. Sometimes, the results ofcorroboratory analyses may be used in a WoE determination to show that attainment is likely despite modeled results which may be inconclusive." Table 2.1: 

### Guidelinesfor Weight ofEvidence Determinations on page 17 states that a WoE demonstration should be conducted when the future ozone design values fall in the range of82 to 87 ppb. Due to the inevitable uncertaintythatexists with respect to emission estimates, meteorological inputs, and chemical mechanisms, Section 7.1: 

### What Types of AdditionalAnalysesShouldBe Completedas Part of theAttainmentDemonstration?
on page 105 says "EPA believes thatweight ofevidence determinations can be used in some cases to demonstrate attainment conclusions that differ from the conclusions ofthe model attainmenttest."
TCC commented that it supports the WoE section but recommends that it be further strengthened to include the full range of2007-2009 ozone monitoring data, which currently shows compliance with the 84 ppb standard. TCC specifically mentioned that the current Deer Park monitor design value is 81 ppb even though the 2018 projected design value is 87.9 ppb. TCC also mentioned the current Bayland Park monitor design value of84 ppb in contrast to the 2018 projected design value of86.9 ppb.
The commission has updated Chapter 5: 

### Weight of Evidence of this attainment demonstration SIPrevision to include the 2009 ozone monitoring data. At the time that the proposal was prepared, the 2009 ozone season was not complete, and these data could not be included. The 2018 ozone design values estimated by the photochemical model are approximate, based upon the expected changes in emissions between the baseline and the future. The various tools used to estimate the emissions levels, meteorological impacts, and chemical mechanisms areinexactandprecision cannotbe expected.
Emissions Projections The EPA commented that the attainment section did not include use ofthe MATS tool. For the monitored attainment test, the EPA stated that MATS should be used to indicate photochemical model predictions for areas outside ofeach monitor's grid cell array.
The EPA developed MATS to provide regulatory entities conducting SIP reviSion photochemical modeling with a tool for applying the attainmenttest. MATS can be used to apply the attainment test for monitored as well as unmonitored areas. Under the EPA's modeling and analyses guidance, an unmonitored area analysis is recommended to identify areaswherefuture-year design values arepredictedto be greaterthantheNAAQS.
The EPA initially released MATS in June 2007 and subsequently updated MATS in 2009. However, to conduct the attainment demonstration modeling for SIP revisions for the 1997 eight-hourozone standard (e.g., Dallas-FortWorth; May 2007) with submission datesprior to the initial release of MATS, the TCEQ developed and implemented its own software procedures for both applying the attainment test at monitors and conducting an analysis of unmonitored areas. While conceptually similar to MATS, the TCEQ's procedures offer

44 of53advantages, including the advantage that they can be more easily integrated into photochemical modeling output processing streams. Forexample, MATS requires input in latitude and longitude for monitor coordinates, while the TCEQ'sprocedureswork directly with the Lambert Conformal Projection (LCP) monitoring coordinates used in our photochemical modeling applications. Also, MATS cannot easilyhandle multi-yearbaseline photochemical modeling that is for the same month and day, whereas the TCEQ software
can. Regarding the unmonitored area analysis, MATS uses a technique called Voronoi Neighbor Averaging (VNA) for spatial interpolation, while the TCEQ's procedures rely upon the morefamiliarkrigingtechnique. Forthese reasons, MATS was not used for either the monitored attainmenttest orthe unmonitored area analysis.
On February 18, 2009, at the SETPMTC meeting attended by EPA Region 6 staff, the TCEQpresented a comparison of2018future-year eight-hourozone design valuesusing the EPA's MATS and the TCEQ's software procedures (http://www.tceg.state.tx.us/assets/publie/implementation/air/am/committees/pmt set/20090218/2 0090218-smith.pdf). The results of this comparison show the two methods agree closely. Where slight differences in the two methods were found, the error appeared to be with the MATS analysis (e.g., MATS occasionally assigned monitors to the wrong grid cells). In addition, during a conference call on March 10, 2009, with the EPA Region 6 staff, the EPA Office ofAir Quality Planningand Standardsstaff, and theTCEQphotochemical modeling staff, the comparison ofthe two methods was discussed as well as the planned use ofthe TCEQ-derived software procedures rather than MATS for photochemical modeling in this attainment demonstration SIP revision. During neither meeting did the EPA indicate that MATS was scientifically superior to the TCEQ-derived software procedure for conducting themonitored attainmenttest. Although the comparison ofthe two methods focused primarily on the application ofthe attainment test at monitors and not the unmonitored area analysis, it was not considered necessary to conduct an unmonitored area analysis. The HGB area is well-monitored. As discussed in Chapter 3: Photochemical Modeling of the attainment demonstration SIP revision, including non-regulatory, industry-sponsored monitors thathave a baseline design value (DVs) and a relative response factor (RRF) denominator greater than orequal to 85 ppbmitigates the need to conduct an unmonitored area analysis for thearea represented by the non-regulatory monitor. The relatively large number ofmonitors, both regulatory and non-regulatory, industry-sponsored, deployed in the HGB area provides adequate coverage, such thatthere are no areasoutside ofa monitor's7x7 grid cell array for which future-year design values are predicted to be greater than the NAAQS. However, since the EPA, in its comments and subsequent follow-up discussions, expressed strong concerns about the TCEQ's decision to omit the unmonitored area analysis, the issue was re-visited as discussed further in this response to comments. Use ofMATS is a partofEPA's guidance, not rule or statute. Since the TCEQ has developed a less resource-intensive yet consistent tool, the commission contends thatit is not necessary to conduct a duplicative exercise with the limited resources and time constraints ofthis SIPrevision. Due to these constraints, the re-analysis uses the kriging method and not MATS. lfnecessary, a MATS analysis could be provided ata laterdate. Figure 13: 2 km Modeling Domain Grid Cells Projecting Eight-Hour Ozone DVF Greater than 84 ppb, and 7x7 Grid Cell Arrays for Regulatory Monitors shows a map of the 2 kilometer (km) modeling domain depicting those grid cells with a projected DVF greater than the NAAQS (shown in pink), and the 7x7 grid cell arrays around each of the regulatory monitors as well as the WALV; CAMS 617 non-regulatory, industry-sponsored monitor (shown in purple). The grid cells with a projected DVF greater than the NAAQS were determined using the kriging technique. As shown in the figure, there are eight grid cells with a projected DVFgreaterthan the NAAQS that fall outside the 7x7 grid cell array around the WALV; CAMS 617 non-regulatory, industry-sponsored monitor. However, 45 of53these eight grid cells are within a 7x7 grid cell array around the Baytown Wetland Center (BYWC; CAMS 552) non-regulatory monitor. Although the BYWC; CAMS 552 nonregulatory monitor does not receive the level of quality assurance and quality control (QA/QC) required for regulatory status, the measured ozone concentrations at BYWC; CAMS 552 are more appropriatefor testing attainment than a concentration derived from kriging. The BYWC; CAMS 552 non-regulatory monitor bas a DV8 equal to 85.3 ppb and
a RRFof0.954yielding a DVF less than 85 ppb. Applyingthe attainmenttest attheBYWC non-regulatory monitor mitigates the need to conduct a MATS analysis for the eight grid cells with a projected DVF greater than the NAAQS, derived from kriging. A modified modeling analysis is presented in Chapter 3: Photochemical Modeling and Appendix C: Photochemical Modeling for the HGB Attainment Demonstration SIP that includes the BYWC non-regulatory monitor.

• D\11 >=**8~**ppb {bl06.a;Deb)



### ttJ:tttttttt:1=t!:tittttm:ttttttttl:Jj:ttttllid:i:±±tttu

- HGB03DV 5i1e 200MOoe 711.7 210mCell> • HGBAQ Slli200!1120oe [::=J HG2x:J<m C3-a

Figure 13: 2 km Modeling Domain Grid Cells Projecting Eight-Hour Ozone DVF Greater than 84 ppb, and 7x7 Grid CellArrays for RegulatoryMonitors

46 of53EDF and GHASP commented that VOC emissions 

### will steadily rise out to 2018, specifically citing Table 3-13: Summary of2006Baseline and2018 Future Base, and2018 Control Strategy Anthropogenic Modeling Emissions for HGB on page 3-25 of the proposed attainment demonstration SIP revision. EDF and GHASP requested ajustification for a roughly I00 tpd increase in VOC emissions from point sources by 2018. TCC requested justification for the projected point source VOC increase in Table ES-1: Summary of2006 Baseline, 2018 Future Year, and 2018 Control StrategyAnthropogenic Modeling Emissionsfor HGB ofthe proposed attainment demonstration SIP revisionof208.34tpd in 2006 to 306.77tpd in 2018. Positive VOC emissions growth within the eight-county HGB nonattainment area was projected for the area and point source categories. Area and point source VOC modeling emissions for the 2018 future yearwere developed using growth factors applied to the 2006 baseline modeling emissions. Emissions growth factors were developed using trends in demographic, economic, and commodity production activity data and the EPA's Economic Growth Analysis System (EGAS) version 5.0, which associates activity data with emissions. Two sets ofactivity datawere used: (1) the Dallas FederalReserve Bank'sTexas Industrial Production Index (TIPI) data, which is specific to an industry's Standard Industrial Classification (SIC) (e.g., petrochemical manufacturing); and (2) a Texas-specific application ofthe Regional Economic Models, Inc (REMI) model data, which is specific to the source category classifications (SCCs) within an SIC (e.g., product tanks at a petrochemical manufacturingfacility).
Both the TIPI and the REMI data sets were used with EGAS version 5.0 to derive two sets ofemission growth factors, i.e., TIPI-EGAS and Texas-specific REMI-EGAS. The Texasspecific REMI-EGAS also includes growth factors for area source categories.
As reported in Chapter 3: PhotochemicalModeling ofthis attainment demonstration SIP revision, 2018 area source emissions, including VOC emissions, were estimated by applying theTexas-specific REMI-EGAS growth factors to the 2005 TexAER database. However, no growth orcontrol factors were applied to the flash emissions, which are now subject to the storagevessel and degassing rule in Chapter 115 because currently the emission reductions
are not quantifiable. Since the net result of the controls and future growth in flash emissions will likely result in emissions reductions, the current modeling likely overestimatesthefuture-year area sourceVOC emissions. Also, as reported in Chapter3: PhotochemicalModeling ofthis attainment demonstration SIP revision, 2018 point source emissions, including VOC, were estimated by applying the largerofthe TIPI-EGAS, REMI-EGAS growth factors, orbanked ERCs and DERCs to the 2006 baseline emissions. This growth was applied to account for emission increases at nonmajor sources-and modifications at major sources that are not significant, neither ofwhich would require offsets. Considering the recent decreasing trend in reported point source VOC emissions (Figure 14: HGB PointSource VOC andNOxEmission Trends From 2003 through 2007), selecting the larger ofthe growth factors may overestimate the growth in point source emissions by 2018.

47 of53HGB Point SourceVOC and NOx Emissions Trend 2003

- 2007

2003 2004 2005 2008 2007 Emission Reporting Year Figure 14: HGBPoint SourceVOC and NOx Emission Trends from 2003 through 2007
In the December 2004 HGB MCR SIP revision (Project Number 2004-042-SIP-NR), 2007 future-year VOC emissions were 255 tpdcomparedto the 2018 future-year emissions of290 tpd in this proposed attainment demonstration SIP revision. The corresponding NOx emissions are 512 and 377 tpd, respectively. Since modeling sensitivities for both SIP revisions indicate that, with the exception of HRVOC, ozone formation is much less sensitive to VOC than NOx reductions, the increase in projected point source VOC emissions should not compromise attainment. As noted, the increase in VOC is due to growth projections, primarily from non-major area and point sources; itis not a result ofa relaxation or removal of a SIP requirement. Therefore, the increase is not backsliding underthe one-hourozonestandard.
A conservative estimate ofemissions growth for future-year attainment modeling was used in this attainment demonstration SIP revision. Subsequently, both the 2006 baseline modeling emissions and the 2018 future-year emissions, including the VOC emissions for point sources, have been reevaluated and revised based on updates to the 2006 State of Texas Air Reporting System (STARS) point source database. The revised 2006 and 2018 point source modeling emissions for the eight-county HGB nonattainment area are 241 tpd and 290 tpd, respectively, representing a growth of 49 tpd, which is approximately 1.6 percentperyear.
Because the executive director has committed to a mid-course review, VOC emissions and theirgrowth may be reevaluated atthattime, ifappropriate,toassess thevalidityofgrowth assumptions used within this SIPrevision.
Emissions Reconciliation The EPA commentedthat the TCEQ'smethod ofreconciling reported emissions ofHRVOC with ambient concentrations adds 10 tpd ofemissions to Harris County, using a technique derived from the PSCF- The EPA requested confirmation that 6 tpd ofthe additional 10 tpd originate from HECT sources. The EPA commented that removing these 6 tpd in 2018 is not justified because there are no additional rules or enforceable commitments in the proposed attainment demonstration SIP revision.
The commission partitioned the 10 tpd added through emissions reconciliation into 6 tpd from HECT sources and 4 tons from non-HECT sources, assuming the additional tons were distributed proportionally to 2006 reported emissions. The proposed attainment 48 of53demonstration SIP revision narrative was clarified accordingly. The commission disagrees with the EPA's contention that removing the 6 tpd of HRVOC emissions is unjustified. Nevertheless, 2018 control strategy photochemical modeling has been revised so that the additional6tpdis not removed.
The EPA commented that the PSCF-based emission reconciliation improves model performance but that even with the added HRVOC emissions, the model underestimates the peak ozone levels. The EPA expressed concern that the reconciliation method did not add sufficient emissions to allow the model to replicate the highest peaks. The EPA suggested two reasons this occurs: (1) incommensurability ofmodeled and measured concentrations; and (2) using a multi-year annual
mean inthe reconciliation.
The commission agrees that the emissions reconciliation improves model performance and that, in some cases, the model does not simulatethe highest observed one-hourozone peaks. However, this attainment demonstration SIP revision is for the 1997 eight-hour ozone standard, not the one-hour ozone standard, and the model usually does not underestimate observed peak eight-hour ozone concentrations. The emissions reconciliation method was designed to improve the characterization ofroutine HRVOC emissions, and neither it nor any other available methodology is capable of a prior prediction of emission events or random emission fluctuations that may cause higher precursor concentrations on specific days. The commission agrees that incommensurability issues may affect the emission reconciliation, but that by using median values in the calculation, this effect should be minimized. Finally, the EPA is mistaken in its claim that the TCEQ used a multi-annual
mean in its application ofthe emissions reconciliation. In fact, the PSCF adjustment was applied separately for 2005 and 2006. RetrospectiveModeling The EPA commented that the retrospective modeling between 2000 and 2006 is not conclusive in showing responsiveness to emission controls. The EPA stated that ozone design values and meteorology for the time periods are different. The EPA emphasized that conclusions cannot be reached about model responsiveness to controls due to the overall uncertainty in estimated emission levels. Uncertainty does exist in both the 2000 and 2006 emissions inventories, as itdoes for any set ofemission estimates. Both ofthe inventories were reconciled with observational data so that the emission inputs used in the retrospective modeling analyses reflect available adjusted inventories. The commission asserts thattheretrospective analysis included in this modeling demonstration is appropriate and is in accordance with EPA's modeling and analyses guidance.
The EPA's modeling and analyses guidance does not precisely specify how a retrospective analysis should be done butratherprovides flexibility to states in how to carryout this kind ofanalysis. The commission decided to use the same methodology that the EPA prescribes for an attainment demonstration, which includes modifying the observed design values by the RRF developed from the modeling. In this instance, the relative change between 2000 and 2006 was used in the same way that the relative change between 2006 and 2018 was used in the RRFcalculation. Figure 15: Modeled and ObservedResponse to Emission Changes Between 2000 and 2006 shows how the model and observations respond to the emission changes between 2000 and 2006. The model predicts ozone design values 15 percent lower with 2006 emissions compared to 2000 emissions. But the observations show that the ozone design values actually decreased by 28 percent from 2000 to 2006. Figure 16: Modeled and Observed Response to WeekendEmission Reductions shows how the model and observations respond

49 of53to emission changes that occur between weekdays and weekends. For the weekend effect, the model response is also less than the observed response. Other studies have also found weakerresponses by themodel than observed. Anotherexample ofhowphotochemicalgrid models have underestimated the response to emission reductions can befound in a studyby EPA scientistAlice Gilliland and colleagues, published in 2008 inAtmosphericEnvironment. In that study, the authors showed that both relative and absolute model response to the NOx SIPcall emission reductions, published on October27, 1998, in theFederalRegister(63 FR57356), are less than the observed responses. For the 2005 version ofthe Carbon Bond (CB05) chemical mechanism, which is used by the TCEQ, the relative response in modeled
ozone concentrations from 2002 to 2005 is about 73 percent of the observed relative response. The retrospective analysis presented in the Chapter 5: Weight ofEvidence, Section 5.2: Corroborative Analysis: Modeling of this attainment demonstration SIP revision is in agreementwith otherstudies showingthatmodeled ozone responseto emission controls is underestimated.



### 110

105

.Q 

### 100 c. c. 

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75 75Retrospective analysis, response to emission changes from 2000 to 2006

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### + 2.6019

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- Linear (Modeled)

1



### y

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### + 12.662

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### 80 85 90 95 100 105 110 2000 Ozone DV, ppb

Figure 15: Modeled and Observed Responseto Emission Changes between2000 and 2006
In Figure 15: ModeledandObservedResponseto Emission Changes Between2000and2006, each point representsthevalues for a particularmonitoring site. Theslopes ofthe response lines showthe degree ofozone decreasefrom 2000 through 2006.

50 of5380

70


# a 60**~** 

## "" c :I 50 rn

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30

90

80

70 

# a Observed and Modeled weekend effect, 8-hour ozone

40 50 60 70 80

Wednesday8-hr 03 • Mod Sunday
• ObsSunday
• Obs Sun >50ppb --1:10ne

········· -10% -20%

Observed and Modeled weekend effect, 1-hour ozone

• Mod Sunday
• Obs Sunday**~** 60 • ObsSun >50ppb --1:11ine c ri! 50

40

30 

## V····

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50 70 90 Wednesday 1-hr03 Observed and Modeledweekend effect, 8-hour ozone
80..----------------,(

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90

80

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# ... 0**~** 60**~** 50

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30 30 40 50 60 70 80 Wednesday 8-hr 03 • Mod Saturday
• Obs Saturday
• Obs Sat>50ppb --1:1ine

......... -10% -20%

Observed and Modeled weekend effect, 1-hour ozone

50 70 90 Wednesday 1-hr03 • Mod Saturday

• ObsSaturday
• OlsSat>50ppb --1:1 ine

......... -10% -20%

Figure 16: Modeled andObserved Responseto Weekend Emission Reductions
In Figure 16: 

### Modeled and Observed Response to Weekend Emission Reductions, blue squares show. average daily maximum modeled ozone concentrations on Wednesday and Saturday or Sunday; green triangles show the average daily maximum observed ozone concentrations on Wednesday and Saturday or Sunday for days with maximum area-wide peakeight-hour ozone over 50 ppb. Thelattervalues are more comparable to the modeled days, since the modeled days have targeted high ozone days. The green triangles show a greater degree ofdecrease during the weekends than the blue squares, indicating that" the model has less response to emission decreases than the observations. The commission made
no changes in response to this comment.
Non-Ozone EmissionsReductions COH commented that the TCEQ should focus on reductions ofairtoxic emissions in the ambient atmosphere. COHstatedthatreducing airtoxic levels will help in reducing ozone formation.

51 of53TheTCEQhas madegreatstridesin drivingindustrial reductions ofairtoxics overthe past several years and will continue to seek additional reductions. Rules related to HRVOC emissions have already been adopted to reduce the levels of ethylene, propylene, 1,3- butadiene, and butenes in the HGB area. While these four compounds are highly reactive chemicals, only butadieneis ofparticulartoxic concern. Though the rules were putin place primarily to reduce ozone formation, substantial reductions of all four, including 1,3- butadiene have been observed at lower monitored concentrations in the HGB area. Other rules have been in effect for several years in the HGB area to reduce overall VOC emissions. Typically, reduction ofoverall VOC will also reduce some air toxic emissions. For example, benzene levels from on-road mobile sources have been reduced as both exhaust and evaporative VOC emissions from automobiles have declined over the last several years. Some of these reductions are due to fleet turnover effects from federal standards, and some result from state rules such as the liM program. Federal and state control programs such as these will continue to provide both air toxic and overall VOC reductions in future years.
Additional work is ongoing at both the state and federal levels to reduce ozone precursors that will also yield lower toxic levels. Forexample, under the contingency plan description in Chapter 4: Control Strategies andRequiredElements, Section 4.9: Contingency Plan of the proposed attainment demonstration SIP revision, an EPA-proposed rule to reduce air toxic emissions from stationary diesel and gas-fired engines is discussed. Iffinalized, that rule would become effective in 2013. Also, Chapter 6: Ongoing and Future Initiatives, Section 6.2.1: Flare Task Force discusses the formation of a Flare Task Force that is charged with "evaluating how flares factor into air quality challenges with an emphasis on airtoxics andozone."
The TCEQ's Toxicology Division analyzes monitoring data for over 100 toxic pollutants in the HGB area and works with other areas of the agency, such as enforcement, field operations, andpermitting, to encourage and promotereductions oftoxic airpollution.

EDF and GHASP commented that reductions in ozone precursors are also known to reduce particulate matter (PM) levels. EDF and GHASP urged for more ozone precursor controls that would have accompanyingPMreductions.
The commission concurs that some ofthe control strategies designed to reduce NOx and VOC also reduce particulate emissions of organic carbon, elemental carbon, sulfate, etc. This attainment demonstration SIP revision contains sufficient NOx and VOC controls to demonstrate, in conjunction with the WoE analysis, attainment of the 1997 eight-hour ozone standard by 2018. In the event that a future SIP revision is required to demonstrate attainment of a PM standard, the commission will consider strategies for necessary PM reductions. Thecommission made nochanges in response to this comment.
PhotochemicalModeling Improvements COH requested a listing ofthe changes and adjustments that need to be made to local air quality models sothatthey better reflectactual ozone measurements beingtakenin the area. Photochemical air quality modeling tools are constantly being improved as steady incremental progress is made in the areas ofemissions estimation, meteorological modeling, and chemical processing mechanisms. The latest available improvements in these areas have always been incorporated into air quality modeling efforts, provided those improvements are scientifically valid and mature enough to be used in a regulatory context. This process will continue in the future as various tools are either updated or replaced. Refer to Chapter 5: Weight of Evidence, Section 5.2.1: Solving Modeling Problems ofthis attainmentdemonstration SIP revision for a discussion ofthe improvements thathave been

52 of53made for this modeling exercise and for an explanation about why other improvements
were considered too immature for incorporation into regulatory modeling at this time. Future modeling will address the upcoming MCR and new criteria pollutant standards. Forexample, theWeatherResearch andForecasting (WRF)tool that improves on MMS for meteorological modeling applications is expected to be incorporated. In accordance with EPA guidance, the recently released Motor Vehicle Emission Simulator (MOVES) model (http://www.epa.gov/otaq/models/moves/) will be used instead of the current MOBILE6.2 for estimation ofon-road mobile source emissions. Chapter 6: Ongoing and Future Initiatives ofthis attainment demonstration SIP revision describes a set of ongoing and future initiatives that will result in improved air quality model performance for the HGB area. A Flare Task Force has been working since November 2008 to evaluate "how flares factor into air quality challenges with an emphasis
on air toxics and ozone." Ongoing field testing for a flare study should be completed by March2010, with final results expected bythe summer2010.
Another major effort more fully discussed in Chapter 6: Ongoing andFuture Initiatives of this attainment demonstration SIP revision is the Study ofHouston Atmospheric Radical Precursors (SHARP). That extensive field study ofozone precursors and formation in the HGB area was conducted from April through June 2009 using cutting-edge measurement technology. Specific areas of interest included under SHARP are direct emissions of formaldehyde and nitrous acid, ambient levels of nitryl chloride, and ozone formation mechanisms related to the spring and early summer time periods. As they become available, the results ofthe flare and SHARP studies will be incorporated into air quality modelingefforts.
Inclusion ofPowerPlantEmissions OutsideoftheHGBArea CAIT, KIDS, SEED, and one individual commented that the attainment demonstration failed to adequately account for new power plants that have either already been permitted or are currently undergoing the permitting process. CAIT, KIDS, SEED, and one individual claimed that the NOx and VOC emissions from these new power plants in Robertson, Milam, Calhoun, Goliad, and Matagorda Counties will blow into the HGB area and contribute to ozone violations.
The commission disagrees with this comment. The specific sources identified by the commenter were accounted for in the attainment demonstration. Chapter 3: Photochemical Modeling, Section 3.4.4.1: Point Sources ofthis attainment demonstration SIPrevision states "Newly-permitted ARD [Acid Rain database] sourceswere limited to the [Texas] Clean Air Interstate Rule (CAIR) 9.5 percent set-aside for growth." Appendix B: Emissions Modelingfor the HGB Attainment Demonstration SIP, Section 2.3.1.1.1: EGUs expands upon that statement, explaining that newly-permitted electric generating units (EGU) are included in the 2018 modeling. The units for which the commission issued air permits as ofNovember 2009 were included in the modeling and are specifically listed in Appendix B: Emissions Modelingfor theHGBAttainmentDemonstration SIP, Section 2.3: 2018 Future YearPointSourceModeling EmissionsDevelopment. Thelist ofEGUs provides the growth in the EGU sector for the entire state. Units that have applied for but have not yet been granted a permit were excluded from the future modeling inventories. Historically, many units have withdrawn permit applications prior to permit issuance due to market speculation and/or market changes. The commission does not speculate which of those permit applications will result in units being built, so only permitted units are included. Thecommission made no changes in responseto this comment.

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