Bryan W. Shaw, Ph.D., Chairman 

Buddy Garcia, Commissioner 

Carlos Rubinstein, Commissioner 

- . : ~~·.-> .:.\ \ .: I· 

!d:~ fJLr.;·u:i: 

. !· 

Mark R. Vickery, P.G., Executive Director 10 APR -9 Pii 1:55 

TEXAS COMMISSION ON ENVIRONMENTAL QUALITY 

Protecting Texas bg Reducing and Preventing Pollution 

April6,2010 

Docket No. 2009-0802-SIP, Project No. 2009-017-SIP-NR ~ 

Docket No. 2009-0932-RUL, Rule Project No. 2009-006-101-EN · 

Docket No. 2009-0867-RUL, Rule Project No. 2009-019-101-EN 

A1 Armendariz, PhD, Regional Administrator 

U.S. Environmental Protection Agency- Region 6 

1445 Ross Avenue 

Dallas, Texas 75202-2733 . 

Dear Dr. 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 Subchapter H, 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 GB Attsinment Demonstration SlP Revision for the 1997 Ei t-Hour Ozone Standard. These rule 

changes and SIP revisions demonstrate that the HGB area will attain the 1997 eight-hour ozone National 

Ambient Air Quality Standard by June 15, 2019. 

Enclosed are the proposed revisions to the SlP, a public hearing certification, a complete record of the public 

hearings, and the accompanying orders.· I look forward to your expeditious approval of these SlP revisions. 

Sincerely, 

B ~,;ktw.--· B~haw,PhD. Chairman 

BWS/jmm 

Enclosures 

cc: The Honorable Rick Perry, Governor ofTexas 

Mr. Toby Baker, Office ofBudget, Planning and Policy, Office of the Governor 

Mr. Mark R Vickery, P.G., Executive Director, Texas Cor!unission on Environmental Quality 

P.O. Box 13087 Austin, Texas 78711-3087 512-239'1000 1ntemet address: www.tceq.state.tx.us 
Texas Commission on Environmental Quality 

Public Hearings 

Odober 28-29, 2009 

Houston-Galveston-Brazoria (HGB) 

Attainment Demonstration SIP Revision 

for the 1997 Eight-Hour Ozone Standard 

Projed Number 2009-017-SIP-NR 

Volume 2 of2 
EVALUATION OF 

TESTIMONY 
Texas Commission on Environmental Quality INTEROFFICE MEMORANDUM 

To: Commissioners Date: February 19,2010 

Thru: LaDonna Castafiuela, Chief Clerk 

Mark R. Vickery, P.G., Executive Director ~1) 

From: Susana M. Hildebrand, P .E, ChlefEngin~ \ .\ ~ 1)l 

Docket No.: 2009-0802-SIP 

Subject: Commission Approval for Adoption 

Houston-Galveston-Brazoria (HGB) Attainment Demonstration State Implementation Plan 

(SIP) Revision for the 1997 Eight-Hour Ozone Standard · 

Rule Project No. 2009-017-SIP-NR 

Background and reasons for the SIP revision: 

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 October 31, 2008. The state is required to submit a SIP revision addressing the· 

severe ozone nonattainment area requirements of the Federal Clean Air Act (FCAA), 42 United States Code 

(USC), §7410 by Apri115, 2010. 

Scope of the SIP revision: 

A) Summary of what the SIP revision will do: . . . . 

This SIP revision uses photochemical modeling in combination with a weight of evidence (WoE) evaluation 

to support a conclusion that the HGB area will attain the 1997 eight-hour ozone NAAQS by June 15, 2019. 

Demonstration of attainment involves a photochemical modeling analysis that predicts ozone design values 

in 2018. The photochemical modeling analysis consicicrrs federal, state, and local control measures, 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 

control measures not explicitly accounted for in the photochemical modeling. · 

B) Scope required by federal regulations or state statutes: 

This revision contains the FCAA-required SIP revision elements, including analyses for reasonably available 

control technology (RAC1) and reasonably available control measures (RACM), a motor vehicle emissions 

budget (MVEB), transportation control measures (TCMs ), and a contingency plan. 

C) Additional staff recommendations that are not required by federal rule or state statute: 

None. 

Statutory authority 

The authority to propose and adopt this SIP revision is derived from Texas Health and Safety Code, Texas 

Clean Air Act (TCAA), §382.002, which provides that the policy and purpose of the 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 commission to prepare and develop a general, 

comprehensive plan for the control of the state's air; and Texas Water Code, §5.102, General Powers, and 

§5.013, General Jurisdiction of Commission. 
Commissioners 

Page2 

February 19, 2010 

Re: Docket No. 2009-0802-Sn> 

The FCAA,42 USC, §§740l, et seq., requires states to submit SIP revisions that specify the manner in yyhich 

the NAAQS will be achieved and maintained within each air quality e9ntrol re~ion of the state. Phase 1 of 

the EP A•s implementation rule for the 1997 eight-hour ozone stahdard, published in the April30, 2004; issue 

of the Federal Register (69 FR 23951), outlines classifications, atta.inment dates, and anti-backsliding 

principles. Phase 2 of the EPA's implementation rule for the 1997 eight-hour ~dard, published in the 

November 29, 2005, issue of the Federal Register (70 FR 11612), outlines the tequrrements for state plans~ 

Effect on the: 

A) Regulated community: 

The affected regulated community will be those associated with the rulemakings that are p!U't o~:~ 

Sn> revision. For further information, see the executive sUill)llaries. for the following rulemak:ings, 

which are.being adopted conclmenily with this Sn> ~v!sion. · . · 

• Rule Project No. 2008-019-115-EN, Volatile. Organic Compounds (VOC) Control 

Technique Guidelines (CTG) Update 

• Rule Project No. 2009-006-101-EN, HECT Program Cap Reduction and Allowance 

Reallocation . . . . . . 

• ·Rule Project No. 2009-019:-10l-;EN, Mass Emissions Cap and Trade (MECT) Pro~;Qap 

Integrity for the HGB Eight-Hour Ozone Ncmattainment Area ·, · t; · 

Fiscal impact infol'll1ation on the previously referenced rulemakings.associated with this SIP revision 

is included in the e~ecutive swnmilries. atid preambl~s fot the rulemalcings. See the execptive 

summary and preamble for Rule Project No. 2008-019-115-EN, VOC CTG Update;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 

transportation planning agency for the HGB area. 

B) PubHc: . . , 

The general publi¥ in the HGB and surrounding areas .will benefit from reduced ground-level ozon,e 

cc>ncentrations due to reduced emissions of o,zone pr~ursors. Ulere will :be no fiscal 'impact on the 

public. 

C) Agency programs: 

The Office of Compliance and Enforcement (OCE) conducts field investigations . to verify 

compliance with the rules addressed in SIP revisions. Enforcement of any revised rules in this Sn> 

revision would not significantly increase the number of facilities investigated by· state and local 

governments. However, the rule revisions may increase the OCE workload when investigating the 

affected facilities .. 

Staff solicited comments on whether it is appropriate to perform a mid-course review (MCR) and, if 

so, what elements should be contained in the analysis. Staff also recommended that the .colillllission 

seek input on the appropriate date to submit the MCR. An MCR could require additional resourees 

and increase the Air. Quality Division workload. In respon.Se to comments received, the staff..will 

perform a 1997 eight-hour ozone MCR for .cominission consideration and approval and submittal to 

the EPA (see ."Significant clianges from proposal" section). ' · 
Commissioners 

Page3 

February 19, 2010 

Re: Docket No. 2009-0802-SIP 

Stakeholder meetings: 

The HGB Eight-Hour Ozone SIP Stakeholder Group met March 25 and 26, and November 3, 2008, to 

discuss development of the 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 July 22, 

2008, to provide baekground on the SIP revision requirements and discuss the process to identify potential 

measures that can be implemented at the local level. Staff also participated in meetings held by H-GAC with 

stakeholder· groups representing airports and airlines, railroads, tug boat operators, the construction industry, 

ports and users of marine equipment, users of non-road mobile industrial equipment, local governments, and 

the public. 

Stakeholders provided comments on a broad range of potential control measures for point, area, and mobile 

sources of ozone precursors. Stakeholders also commented that evaluation and detennination of control 

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 

TCMs and VMEPs. 

Public comment: 

Public hearings for the proposed SIP revision and associated rulemakings were held on October 28, 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., 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 

6:00p.m. nor the October 29, 2009, hearing was officially opened because no party indicated a desire to 

provide comment Five persons presented oral comments concerning this SIP revision at the public hearing 

held at 2:00p.m. on October 28, 2009, in Houston. 

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, the use of WoE, conducting an· MCR, attainment of the 1997 eight-hour ozone 

standard in the HGB area, and specific control strategies as well as the RACT and RACM analysis. While 

several comments expressed support for this attainment demonstration SIP revision and its photochemical 

modeling analysis and weight of evidence determination, a number of commenters contended that this SIP 

revision does not demonstrate attainment of the 1997 eight-hour ozone standard by the June 15, 2019, 

deadline. Some of the commenters who opposed this SIP revision also expressed opposition to the use of 

WoE to augment photochemical modeling. · 

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 

consideration by the EPA. The City of Houston (COH), suggesting that the HGB area is attaining the 1997 

eight-hour standard, recommended that the TCEQ develop a redesignation request and maintenance plan for 

submission to the EPA and to concentrate future efforts on the revised ozone 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 concerning the rules associated with 

this attainment demonstration SIP revision. For a summary of comments more directly related to the 30 
Commissioners 

Page4 

February 19,2010 

Re: Docket No. 2009-0802-SIP 

Texas Administrative Code (TAC) Chapter 101 :MECT Program Cap Integrity (Rule Project No. 2009-'019-

.·. 101-EN).and HECT-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 

summary memos;for each of those rules. ; •· , .. , , 

Significant changes from proposal: . . . 

Significant changes were made' to the VOC RACT update element of this SIP revision in response ~o 

conunents. Staff proposed that 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 .staff may reevaluate the RACT analyses. The RACT determinQtion.fot the 

Fiberglass Boat Manufacturing CTG categoty .was proposed as not representing RACT for -the HGB area due 

to the potential econori:rlc impact to small businesses; howeVer, additional staff researeh indicates that no 

sources meeting thf,LCTG appliCability exist .iti the HGB area:. . Therefore, the RACf deteni\ination:for 

Fiberglass Boat Manufacturing was changed to a negative declaration. 

In preparing the response to the comments, staff reviewed the 2006 baseline, a.S well as the 2018 projecte9 

emissions, including the reduction to the reconciled emissions of highly reactive volatile 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~ 

reflects the .use .of the updated Texas NONROAD (TexN) model with a more recent database of equipment 

populations. For the 2018 projected emissions, updates were also made to the point sources and the non-road 

mobile sources. The updates to the point sources included changes in .the application of growth.f~ors,to 

non-:MECT sources, a revision to the :MECT allocations reflecting more recent emission certifications, and 

removing the r~duction of reconciled emissio~ of HRVOC in 2018. Similar to the 2.00.6 baSeline; _:t;he 

revision to the 2018 non-road mobile source emissions reflects the use of the upW.,ted TexN model with a 

more recent-database of equipment populations. 

The cbang~s in the2006 baseliile and 2018 future base emissions resulted in slightly smaller ,2018 projected 

eight-hour ozone design va.J.ues. All regulatory monitors have projected eight-hour ozone design values less 

:than 87 parts per billion (ppb). ·The projected· control strategy 2018 eight-hour ozone design values for tbe 

highest two monitors are also slightly lower than originally presented in the proPQsal (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 

modeling results. . . .'/ 

To address comments·to the SIP revision and to suppleinent.the corroborative analyses of Chapter 5: Weight 

; ofEvidence, additional analyses that address the effects of meteorology and economic factors on ozone 

trends have been included in Appendix I: Corroborative Analysis for the HGB Attainment Demonstratioh 

SIP Revision for· the 1997 Eight-Hour Ozone Standard as well as an. emissions. trend analysis. The 

discussion of model responSe to emission changes bas been broadened and trends in VOC reactivity have 

also been analyzed and also added to Appendix I. 
Commissioners 

PageS 

February 19, 2010 

Re: Docket No. 2009-0802-SIP 

In response to comments received, the executive director's staff will perform 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 of all modeling, inventory data, and other tools and assumptions used to develop the attainment 

demonstration. This effort will include a review of the control measures, WoE, and contingency plan as well 

as additional analysis that may include photochemical modeling if appropriate. The MCR will contain 

further evaluation of the potential state and federal measures and new programs or regulations. This MCR 

will also include the ongoing assessment of new technologies and innovative ideas for possible inclusion into 

the plan. 

The TCEQ executive director will commit to include for commission. approval sufficient additional measures 

to equal 3 percent of the emissions in the adjusted base year inventory to be implemented in the event that 

the HGB area does not attain the 1997 eight-hour ozone standard by June 15, 2019, at the time of an MCR 

for this attainment demonstration SIP revision. . 

In response to comments received applicable to the rules associated with this SIP revision, substantive 

changes were made to the Chapter 101 and 115 rule revisions, which are addressed in the preambles for those 

rules. 

Potential controversial concerns and legislative interest remaining after proposal and public comment: 

In addition to photochemical modeling, this SIP revision relies on WoE, including corroborative analysis and 

discussion of additional control measures not included in the photochemical modeling, to demonstrate . 

attainment. The commission received comments stating that the attainment demonstration should be based 

solely on the photochemical modeling and that because the photochemical modeling analysis shows that the 

proposed control measures will not be sufficient to demonstrate attainment by June 15, 2019, this SIP 

revision should be disapproved. · 

RACT determinations were not made for all of the 11 CTGs issued by the EPA between 2006 and 2008. 

While not stated in formally submitted comments, the EPA has verbally indicated to staff that it may issue 

notices of failure to submit to states that have not yet addressed all of the CTGs. The EPA's issuance of such 

a notice would start an 18-month sanctions clock. The TCEQ may need to address the remaining CTGs in a 

future SIP revision. 

Does this SIP revision affect any current policies or require development of new policies? 

No. 

What are the consequences if this SIP revision does not go forward? 

The legal requirement is to submit an attainment demonstration SIP revision for the 1997 eight-hour ozone 

standard by Aprill5, 2010. Not submitting a SIP revision to the EPA could result in a Federal 

Implementation Plan and/or federal sanctions. 

Are there alternatiVes to this revision? 

This SIP revision is required by federal statute. There are no alternatives. 

Key points in adoption request schedule: 

Texas Register proposal publication date: NA 

Anticipated Texas Register publication date: NA 

Anticipated effective date: NA 

Six-month Texas Register filing deadline: NA 
Commissioners 

Page6 

February 19, 2010 

Re: Docket No. 2009-0802-SIP 

. Agency contacts: 

Lola Brown, SIP Project Manager; 239-0348, Air Qilality Division 

· John Minter, Staff Attorney, 239·0663 

cc: . :ChiefClerk, 5 copies 

Executive Director's Office 

Susana M. Hildebrand, P .E. 

Kevin Patteson 

Curtis Seaton 

Daniel Womack ' 

Office of General Counsel 

Lola Brown 

. ~;, ' 

i • ~ ~ . 

. ' 
Response to Comments Received Regarding the 

Houston-Galveston-Brazoria (HGB) 

1997 Eight-Hour Ozone Attainment Demonstration 

State Implementation 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 of Houston (COH), Clean Air Institute of Texas (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 of Women Voters of the Houston Area (L WV Houston), 

LyondeliBasell Industries (LyondeiiBasell), PL Propylene LLC (PL Propylene), Printing 

Industries of the Gulf Coast (PIGC), Sustainable Energy and Economic Development Coalition 

(SEED), Texas Association of Business (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 of Manufacturers 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 

of their 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 of the Federal Register (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 (T AC) Chapter 10 I Mass 

Emissions Cap and Trade (MECT) Program Cap Integrity (Rule Project No. 2009-019-10 I-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 Printing rule revisions (Rule Project No. 2008-0 19-115-EN), which are incorporated 

by reference into this attainment demonstration SIP revision, are responded to in the Response to 

Comments section of the preamble to each of those rulemakings. Those comments are included 

in this attainment demonstration SIP revision through the adoption of those rules. Some changes 

were made to the proposed version of this attainment demonstration SIP revision in response to 

those comments. 

I of53 
Contents 

General Comments ............................................................................................................................... 4 

Evaluation of Attainment Demonstration SIP ................................................................................... .4 

General Support for Attainment Demonstration SIP Revision ............................................... .4 

Mid-Course Review ................................................................................................................. 5 

Contingency Plan ..................................................................................................................... 6 

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

Attainment of Standard ....................................................................................................................... 6 

1997 Eight-Hour Ozone Standard ............................................................................................ 6 

Revised Eight-Hour Ozone Standard ....................................................................................... 7 

One-Hour Ozone Standard ....................................................................................................... 7 

Air Quality .......................................................................................................................................... 8 

Emission Reductions ................................................................................................................ S 

Health and Economic Welfare ................................................................................................. 9 

Control Strategies Discussion ............................................................................................................ 10 

HRVOC Emissions Cap and Trade (HECT) Program ..................................................................... 10 

Mass Emissions Cap and Trade (MECT) Program .......................................................................... 11 

Offset Lithographic Printing Rule Revisions ................................................................................... 13 

Identification of Most Effective Ozone Control 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 Task Force Initiative ..................................................................................................... 27 

Photochemical Modeling .................................................................................................................... 28 

Support for Attainment Modeling and Weight of Evidence (WoE) Analyses ................................. 28 

Weight of Evidence (WoE) ............................................................................................................. .30 

Emissions Projections ....................................................................................................................... 44 

Emissions Reconciliation ................................................................................................................. 48 

Retrospective Modeling ................................................................................................................... .49 

Non-Ozone Emissions Reductions ................................................................................................... 51 

Photochemical· Modeling Improvements ..... , .................................................................................... 52 

Inclusion of Power Plant Emissions Outside of the HGB Area ....................................................... 53 

2 of 53 
List of Figures 

Figure 

Figure I 

Figure 2 

Figure 3 

Figure 4 

Figure 5 

Figure 6 

Figure 7 

Figure 8 

Figure 9 

Figure I 0 

Figure 11 

Figure 12 

Figure 13 

Figure 14 

Figure 15 

Figure 16 

Figure Name 

Wind Data from Houston Aldine 

Meteorologically Adjusted Ozone Trends in the HGB Area from 1997 through 

2008 (Source: EPA) 

Number of Ozone-Conducive Days and Number of Ozone-Conducive Days with 

Ozone Greater Than 84 ppb (Source: URS Corporation) 

Forecasted and Actual Eight-Hour Ozone Exceedance Days (1997 NAAQS) in 

the HGB Area 

Frequency of Morning Wind Direction and Wind Speed by Month in the HGB 

Area for 2000, 2004, 2008, and 2009 

Gross Domestic Product of Texas 

Metro Area Business Cycle Index, Houston-Sugarland-Baytown 

Gross Domestic Product of Selected Petroleum Related Industries 

Weekly Gulf Coast (PADD 3) Crude Oil Inputs to Refineries 

Weekly Percent Utilization of Refinery 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 Emission Trends from 2003 through 2007 

Modeled and Observed Response to Emission Changes between 2000 and 2006 

Modeled and Observed Response to Weekend Emission Reductions 

3 of53 
GENERAL COMMENTS 

Evaluation of Attainment Demonstration SIP 

General Support for Attainment Demonstration SIP Revision 

BCCA and the Coalition supported the proposed demonstration that the HGB area will attain the 

1997 eight-hour ozone standard by the attainment deadline of 2019. 

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 that the 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 contribute to attainment of the 1997 eight-hour ozone standard in the i-IGB area. 

The commission appreciates the support and is committed to working with local entities and 

the EPA to ensure attainment ofthe 1997 eight-hour ozone standard in 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 SIP revision 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 of the 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 of 0.060 to 0.070 ppm. The EPA bas also proposed a distinct cumulative, 

seasonal secondary standard within the range of 7 to 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 of the 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 

the EPA and the HGB regional stakeholders in this effort. 

4 of 53 
Mid-Course Review 

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 of the 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 HR VOC cap should be 

reduced in order to 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, so the MCR could be submitted concurrently with the SIP revision for 

the revised ozone standard. TCC suggested that the MCR be conducted prior to the first stepdown period for the proposed HECT program 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 of the 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 later than 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 of all 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. It will also include the ongoing assessment of new technologies and innovative 

ideas for possible inclusion into the plan. For further information regarding the MCR, see 

Chapter 6: Ongoing Future Initiatives, Section 6.3.1: Mid-Course Review (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 and thorough evaluation. 

TCC requested that photochemical modeling scenarios be performed during an MCR to 

determine if the 84 parts per billion (ppb) standard could be maintained while reducing the 25 

percent HECT cap. TCC specifically recommended HECT cap reduction scenarios of 5 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 TCEQ for the HGB area. 

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Contingency Plan 

TCC recommended that the TCEQ, as a potential contingency item during the 2009-2018 period, 

note emissions reductions of volatile organic compounds (VOC) or nitrogen oxides (NOx) that 

are anticipated as a result of consent decrees. 

It is not clear from the comments to what specific consent decrees the commenters are 

referring. The commission does not agree that previously entered EPA consent decrees are 

an appropriate measure to be included as a contingency measure. Though it is possible that 

VOC and NOx emission reductions may occur as a result of consent decrees in the HGB 

nonattainment area, the timing of the emissions reductions and the quantity of reductions 

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 time period and must total to a specific amount (3 percent of 

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 made no changes in response to this comment. 

Reclassification 

EDF and GHASP incorporated by reference as part of their 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 SIP revision. 

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 about the current SIP action, 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 

cut in reductions begins in 2014 in advance of the 2019 attainment date. Under the FCAA, 

§181, the EPA was required to grant the governor's request to reclassify the HGB area and 

the final rule was effective on October 31, 2008 (73 FR 56983). Thus, the comments are not 

relevant to this SIP revision and are outside the scope of this attainment demonstration SIP 

revision. The commission bas made no changes in response to these comments. 

Attainment of Standard 

J!J!J7 Eigbt-Hour Ozone Standard 

HSC and L WV 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 area may still be in nonattainment of the 1997 eight-hour ozone standard in 2018. 

L WV Houston rejected this proposed attainment demonstration SIP revision because it does not, 

on its face, meet the I 997 eight-hour ozone standard. L WV Houston expressed concern about the 

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TCEQ's credibility in developing a plan that will lead to attainment of the 1997 eight-hour ozone 

standard by the deadline. 

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 of 84 ppb 

and this attainment demonstration SIP revision are confirmation that the TCEQ will attain 

the 1997 eight-hour ozone standard in the HGB area by the June 15, 2019, attainment date. 

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 the airshed. 

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 of mathematical 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 of future events. The 

TCEQ has analyzed the appropriate reductions necessary for attainment of the 1997 eighthour ozone standard as described in this attainment demonstration SIP revision. The 

commission has made no changes in response to these comments. 

Revised Eight-Hour Ozone Standard 

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. 

The commission contends that this SIP revision continues to improve air quality in the HGB 

area. The commission will prepare SIP revisions to attain and maintain the new eight-hour 

ozone standard in those areas once nonattainment areas for the revised standard have been 

designated by the EPA. The commission has made no changes in response to these 

comments. 

One-Hour Ozone Standard 

EDF and GHASP commented that, despite recent improvements in ozone levels, the HGB area 

has failed to reduce emissions of ozone precursors to levels sufficient to ensure attainment of the 

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 under the 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 SIP revision. 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 under the one-hour ozone standard. 

7 of 53 
Regarding the one-hour standard, there is no requirement to ensure attainment of this 

standard because it bas been revoked. Phase 1 of the EPA's rules implementing the 1997 

eight-hour ozone standard published in the April30, 2004, issue of the Federal Register (69 

FR 23951) requires that areas designated nonattainment for the one-hour standard at the 

time of designation 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 that the current eight-hour ozone standard is more protective of human health than 

the previous one-hour ozone standard. Specific mention was made of exceedances of the onehour standard during 2007 through 2009 when violations of the eight-hour standard did not occur. 

CAIT, KIDS, SEED, and one individual claimed that the current form of the eight-hour ozone 

standard is flawed because it compensates for weather fluctuations providing unusually high 

design values but does not do so for fluctuations that provide unusually low design values. 

As part of the periodic review of the NAAQS required by the FCAA, the structure of the 

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 that there is insufficient evidence to retain the one-hour ozone NAAQS in order to 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 

Emission Reductions 

BCCA and the Coalition commented that the majority of ozone 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 of these compounds since 1995. Further, BCCA and the 

Coalition commented 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 of this 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 greater Houston 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 of 21 

percent in population. 

Emission reductions from stationary sources have been substantial over the past 10 years in 

the HGB area. More than 500 tpd of NOx emissions were reduced from the electric utility, 

industrial, commercial, and institutional sectors through the 30 TAC Chapter 117: Control 

of Air Pollution from Nitrogen Compounds rules and the NOx MECT program. In 

addition, a wide range of VOC control strategies were implemented for stationary sources 

8 of 53 
in the HGB area, impacting large industrial facilities such as refineries to smaller businesses 

such as printing operations. 

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 of Evidence, 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. The commission has made no changes 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 of expected 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 

attainment test is based upon this definition and is defined as the highest design value at any 

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 

attainment year. These ancillary arguments are collectively known as WoE. 

Conservative photochemical modeling for the 2018 future case, the current preliminary 

2009 HGB area design value of 84 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 MCR concurrently with the revised ozone standard SIP revision, which 

is scheduled to be due to the EPA in December 2013, to help the commission identify 

additional measures or change previously adopted measures to ensure that compliance with 

the 1997 eight-hour ozone standard is maintained. 

Health and Economic 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 area a 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 of human 

health. 

The commission appreciates the comments related to health effects of ozone and economic 

welfare. The commission 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 of safety, to protect the public 

health, including sensitive members of the population such as children, the elderly, and 

9 of 53 
those 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 of the 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. 

The commission strives to protect our state'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 of the state's ozone nonattainment areas. The purpose of this plan is to demonstrate 

attainment of the 1997 eight-hour ozone NAAQS by June 15, 2019, in accordance with the 

EPA's guidance and FCAA requirements. By improving air quality in the HGB area, this 

plan will improve the quality of life for many residents of the HGB area. 

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 of emissions, available control technologies 

for the source category, and other technical 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 attainment demonstration SIP revision. 

CONTROL STRATEGIES DISCUSSION 

HRVOC Emissions Cap and 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-hour ozone 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 5 percent reductions through 2017. 

The adopted rule revisions will reallocate the program in 2011 and implement an initial 10 

percent reduction of the 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 start of each 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 of 53 
time to install controls if necessary. Tbe commission bas made no changes in response to 

these comments. 

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 of the proposed 

attainment demonstration SIP revision. 

The commission 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 attainment demonstration SIP revision. The reallocation of HRVOC allowances 

does not in itself include a mandatory reduction in the HRVOC cap in Harris County. 

However, following the initial allocation of allowances, the TCEQ received comments that 

the allocation was not equitably distributed. Information from the first two years of 

monitoring data supports the assertion of an inequitable distribution of allowances. A more 

equitable allocation of allowances 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 emission point. 

The commission did not propose discontinuation of the HECT program. This comment is 

beyond the scope of this attainment demonstration SIP revision. The commission adopted 

the HECT program having determined it to be the most efficient means by which to achieve 

cost-effective reductions of HRVOC. 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 of HRVOC 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. The commission has 

made no changes in response to this comment. 

Mass Emissions Cap and Trade (MECT) Program 

The EPA requested clarification on the amendment to §I01.353(b) and why it does not require 

minor sources of NOx submitting late ECT -3 fonns to obtain allowances from the market. The 

EPA commented that these minor sources of NOx could increase the overall cap and jeopardize 

the attainment demonstration modeling for the HGB ozone nonattainment area. 

The MECT NOx cap is a product of the emission specifications of Chapter 117 and the 

submitted levels of activity from applicable existing facilities, 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 of allowances, and 

the site must obtain allowances to cover the new facility's total emission of NOx. 

Minor sources of NOx with applicable facilities that are not in the MECT program must 

meet tbe emission specifications of Chapter 117 on a unit-by-unit basis. A minor source of 

II of53 
NOx 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 of Chapter 117. If a minor source of NOx 

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 

purchasing the entire amount of allowances needed to comply with the MECT program for 

each control period if the 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. If an 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 minor sources does slightly increase the MECT NOx 

cap, it does not interfere with the attainment demonstration photochemical modeling for the 

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 at zero (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 of the MECT 

existing facilities' and the MECT new facilities' actual NOx emissions is less than or equal 

to the MECT NOx 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 the allowance allocation amount with zero growth, and the photochemical modeling value 

based on an EPA-approved growth methodology will be discarded. If the modeled MECT 

NOx cap were to increase, then that would result in decreases of the 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, if the model were 

to be run with the new numbers. 

If an existing facility at a minor source of NOx is in the area source inventory, the 

allowances provided to that facility 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 of 53 
respectively. 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 the point source MECT NOx cap. 

Thus, the continued acceptance of late ECT -3 forms from existing facilities at minor sources 

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 

changes in response to this 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 of the MECT program. This comment is 

beyond the scope of this attainment demonstration SIP revision. The commission adopted 

the MECT program having determined it to be the most efficient means to achieve costeffective reductions of NOx. 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. 

Offset Lithographic Printing Rule Revisions 

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 a major source of emissions in the HGB area. 

The commission is aware that printing sources do not constitute a large proportion of the 

emissions in the HGB area. However, revisions to the 30 TAC Chapter 115: Control of Air 

Pollution from Volatile Organic Compounds offset lithographic printing rules are necessary 

to fulfill FCAA reasonably available control 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 SIP Revision for the 1997 Eight-Hour Ozone 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 of the Federal 

Register (71 FR 58745). The purpose of the 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 of Most Effective Ozone Control Strategies 

COH requested a list of the most effective control strategies for reducing regional ozone levels. 

COH also requested that the ozone reductions associated with each of these 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 of 53 
significant 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 of ozone 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 of the effect of each strategy is not possible. Further, the commission bas 

not conducted an analysis of what each strategy bas contributed to ozone reduction because 

this exercise would 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 of possible 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: Reasonably Available 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 at reducing ozone may not necessarily 

be cost effective or technologically feasible. The TCEQ must consider all these factors when 

determining whether a control measure should be implemented as RACM. 

The attainment demonstration SIP revision contains sufficient reductions of both NOx and 

VOC precursors to demonstrate, in conjunction with the WoE analysis, attainment of the 

1997 eight-hour o:zOne standard by 2018 in HGB. The commission has made no changes in 

response to this comment. 

Mobile Sources 

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 older vehicles. 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 T AC Chapter 114: Control of Air Pollution from 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 percent in 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 of Rule Project No. 2007-026-114-EN, the commission bas opted not 

to implement final cut-points for ASM inspections. The commission has made no change in 

response to this comment. 

14 of 53 
EDF 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 of the Texas 

Inspection and Maintenance State Implementation Plan since 1996. The program was 

implemented in the HGB area in 1998. The Texas Department of Public 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 that can be conducted at any DPS-certified 

safety· and emissions inspection station. In addition, the motorist is informed that if the 

vehicle fails the verification inspection, the vehicle is required to be brought into compliance 

with the 11M program requirements. If the motorist fails to comply with the request 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 per offense for the continuance of noncompliance and the vehicle may be denied 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 of Appendix G. 

The commission appreciates the comment and has updated Appendix G: Transportation 

Control Measures for the HGB Attainment Demonstration SIP Revision 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: 

Projects with Applicable Benefits to show bid acceptance dates 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 during transit, the TCEQ has 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 Chapter 5: Weight of Evidence, Section 5.4.3.10: 

American Waterways Operators Tank Barge Emissions Best Management Practices of this 

attainment demonstration SIP revision. 

The point source inventory accounts for barge emissions while docked. The TCEQ has 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 of Fugitive Emissions from 

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 of53 
REASONABLY AVAILABLE CONTROL TECHNOLOGY (RACT), REASONABLY 

AVAILABLE CONTROL MEASURES (RACM) 

RACT, RACM Adequacy 

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 of NOx 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 or exceeds RACT for each applicable CTG 

source category or non-CTG major emission source; and (4) describing the basis for 

concluding that these regulations fulfill RACT. 

As described in the RACM analysis in Appendix E: Reasonably Available Control Measure 

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 of the 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 cap under the HECT program, met the criteria to be considered RACM. 

All other potential control measures 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 of the commission's determinations regarding measures 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 of NOx 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 of the 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 reasoned justification for the rejection of 

RACM applies equally to the rejection ofRACT. 

16 of 53 
The commission disagrees that the current attainment demonstration SIP revision does not 

provide a reasoned justification 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 measures for major sources of NOx 

and VOC emissions are being implemented. However, Appendix D: Reasonably Available 

Control Technology Analysis, Table D-2: State Rules Addressing RACT Requirements for 

Major Emission Sources in the HGB Area of this attainment demonstration SIP revision 

identifies the state regulation that implements or exceeds RACT for each applicable major 

emission source category and describes the basis for concluding that these regulations fulfill 

RACT. The commission made no changes in response to this comment. 

RACT 

EDF and GHASP expressed support for RACT rules limiting the VOC content of solvents used 

by offset lithographic printing operations and expanding the rule applicability to include currently 

unregulated sources. 

The commission appreciates the support. 

HSC commented on the statement in the preamble to the offset lithographic printing rule revision 

(Project No. 2008-0 I 9-I I 5-EN) that the commission does not agree that applying RACT 

standards to future equipment installations is necessary to meet the mandates of the FCAA under 

§§I 72(c)(I), I 82(b)(2), and I 82(t). HSC commented that the commission has stated publicly that 

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 of the ozone standard in the HGB area. 

The statement referenced by the commenter was included as part of a discussion about the 

EPA's 2006 Offset Lithographic and Letterpress Printing CTG recommendations. 

Specifically, the EPA's CTG recommends requiring 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 of rules implementing 

the CTG to have an overall control efficiency of 95 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 of the control equipment However, in 

response to comments received on the offset lithographic printing rule revision, the 

commission has removed this statement from the rule preamble. 

Additionally, 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 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 of NOx 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 of NOx 

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) 

describing the basis for concluding that these regulations fulfill RACT. 

I 7 of 53 
The 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 of sources evaluated for RACT purposes. 

As discussed in the RACT analysis provided in Appendix D: Reasonably Available 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 of NOx 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 inventory database with emissions of 10 tpy or 

more of NOx that were not identified in the Title V database and could not be verified as 

minor sources by other means are also included in the RACT analysis. 

The EPA requested confirmation that the level of NOx control for affected sources in the HGB 

area still represents RACT today. 

As discussed in the RACT analysis provided in Appendix D: Reasonably Available 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 of the most 

stringent NOx emission control requirements in the country and for many source categories 

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 SIP published in the September 6, 2006, issue of the Federal Register (71 FR 

52676), the EPA noted that the HGB NOx rules in Chapter 117 were previously determined 

to meet the FCAA RACT requirements. The commission maintains that the level of NOx 

control through the Chapter 117 rules and the NOx MECT program still represent RACT. 

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 of the NSR permit. 

The current NOx rules in Chapter 117 do not contain a RACT limit for glass furnaces in the 

HGB area. There were no glass furnaces in the point source emissions inventory year 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) 

of NOx per ton of glass by the site's NSR permit. The level of NOx 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 document Alternative Control Techniques Document-NOx Emissions from 

Glass Manufacturing, which describes oxy-firing as the most effective NOx control 

technique. Furthermore, there are no other glass furnaces in the HGB area. Therefore, the 

TCEQ determined that establishing a NOx RACT rule for the glass furnace source category 

was not necessary for fulfilling RACT for the HGB 1997 eight-hour ozone standard 

attainment demonstration because additional controls were not necessary or possible in this 

specific situation. 

This conclusion is supported by the guidance provided by the EPA in the RACT guidance 

document RACT Qs & As-Reasonably Available Control Technology (RACT): Questions and 

18 of 53 
Answers, 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 what was required for the one-hour ozone standard. 

Question: "What should a State do if it concludes that for a specific source 

or source category no additional controls are necessary beyond what was 

required by the RACT analysis under the 1-hour standard?" 

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 of its 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 permit was first issued in 2000. If the permit holder (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 TCEQ does not expect that this emission limit will be relaxed in the 

future. The executive director's staff will· continue to track the Longhorn Glass 

Corporation permit. If any 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 provide the EPA with a copy ofthe requested permit information. 

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 of an add-on control device with 95 percent efficiency. EDF and GHASP rejected the 

commission's explanation that existing rules are equivalent since the state only requires add-on 

control devices with 90 percent efficiency. 

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 complied with the existing rules. 

The commission also notes that in 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 of 70 percent VOC by volume in conjunction with work practice standards. 

Assuming the VOC in the cleaning solvent used is kerosene, which is the VOC referenced in 

the 2006 CTG, the adopted Chapter 115 content limit of 70 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 content to 5 percent alcohol substitutes or less by 

weight and no alcohol in the fountain solution. To prevent potential backsliding for sources 

already required to comply with these state regulations, the adopted Chapter 115 rules 

retain the more stringent fountain solution content limit of 3 percent alcohol substitutes or 

less by weight and no alcohol in the fountain solution. 

19of53 
The 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 tpy of VOC or more from the dryer. The rules in Chapter 115, Subchapter E, Division 4 

require control devices, with a control efficiency of at least 90 percent, to be installed on 

heatset offset lithographic presses on a property in the HGB area with total uncontrolled 

VOC emissions of at 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: Model Plant 

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 of the 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 of 25 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 of 22 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 of rules implementing 

the CTG to have an overall control efficiency of 95 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 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 date of the control equipment. 

Regardless of the first installation date of the 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 dry basis to accommodate situations where the inlet 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 of 20 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 of expensive 

and unnecessary add-on control devices. 

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 the comment. 

20 of 53 
EDF and GHASP commented that the commission failed to provide an adequate justification 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 of reasonable explanation required of agencies and is unsupportable 

given the significant progress needed to restore healthy air to the citizens of the HGB area. 

The commission provides a negative declaration for the Flat Wood Paneling Coatings CTG, 

Fiberglass Boat Manufacturing Materials CTG, and Auto and Light-Duty Truck Assembly 

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 Metal and Plastic Parts Coatings, Flexible Packaging Printing Materials, and 

Paper, Film, and Foil Coatings. The executive director will proceed with RACT analyses of 

these CTG documents and initiate a future SIP revision and rulemaking for the 

commission's consideration, if necessary, 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 

requirements for offset lithographic printing operations. 

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 of the 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 whether the 

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 determine the quantity of affected sources in the HGB area and plans 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 of these CTG documents and initiate a future SIP revision and rulemaking for the 

commission's consideration, if necessary, 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 of 53 
coatings 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 of these 

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, §II 0(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 constitute RACT 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 submit RACT 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 implementing the work practice requirements or provide analysis demonstrating 

that the requirements are satisfied by existing rules. 

At the September 23, 2009, agenda for proposal of this attainment demonstration SIP 

revision, the commission determined that no sources in the HGB area meet the applicability 

criteria in the 2006 Flat Wood Paneling Coatings CTG. The commission provided a 

negative declaration for the Flat Wood Paneling Coatings CTG source category in Chapter 

4: Control Strategies and Required Elements, Section 4.2: Existing Control Measures, 

Section 4.4.3.1: CTG Documents That Are Not Applicable to the HGB Area of this attainment 

demonstration SIP revision; however, some of the 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: 

Reasonably Available Control Technology Analysis bas been revised to clearly indicate that 

the commission is providing a negative declaration for this emission source category with 

regard to RACT for the HGB area. 

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, Clarification to Appendix D of November 24, 1987 Federal Register" 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 September 23, 2009, agenda for proposal of this attainment demonstration SIP revision, 

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 of 53 
databases. 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 source category with regard to RACT for the HGB 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 the Paper, 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 determinations to the EPA in a timely manner. 

EDF and GHASP disagreed with the statement on Page D-3 of the proposed attainment 

demonstration SIP revision 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 of control 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 that the EPA bas issued CTG documents 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 CTG documents defining RACT for existing facilities. 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 equivalent emission reductions. 

The commission disagrees with the commenters' statement that the commission rejected 

nearly all of the 11 CTG documents. The commission is making a negative declaration for 

three of the 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 of the 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 of 53 
The commission determined that CTG 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 

determinations for these two categories. 

The CTG documents for which the commission is not making a RACT determination at this 

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 director will proceed with RACT analyses of these CTG documents and initiate a 

future SIP revision and rulemaking for the commission's consideration, if necessary, to 

submit RACT determinations to the EPA 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 4 rules 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 

of the 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 of the 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 

emissions could 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 lower the 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 stated that since this HECT cap reduction is based on the fact that emissions from capped 

sources during the first two years of the program only averaged approximately 56 percent of the 

total allocated allowances, the commission should not claim that 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 air quality improvement. 

The commission agrees that the HECT reallocation and cap reduction does not require 

mandatory reductions of HRVOC emissions from program participants. The purpose of 

the rulemaking is to reallocate the program for a more equitable distribution of allowances 

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 of 53 
Photochemical modeling analysis demonstrates that the proposed HECT rule revision, 

which includes a reallocation and 25 percent reduction of the HRVOC emissions in Harris 

County, would advance attainment of the 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 (BA YP; 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 modeling decreased 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 of the 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 

program has been active cannot be removed. Therefore, a buffer in the cap is still needed to 

account for the inherent variability of HRVOC emissions associated with these activities. 

The 25 percent reduction in the Harris County HRVOC cap allows for a sufficient buffer to 

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 

for WoE discussion. 

EDF and GHASP suggested a number of additional general VOC control measures that should be 

considered sources of additional emission reductions. EDF and GHASP commented that current 

rules for condensate tanks in § ll5.ll2(a)(3) only require a control device capable of a 90 percent 

reduction. EDF and GHASP suggested additional reductions in flash emissions from 

hydrocarbon storage tanks, by requiring installation of a control device capable of a 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 of other 

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 pumps to 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 combustion engines rated I 00 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, the commission determined that reductions in general VOC emissions (i.e., 

non-HRVOC emissions) would not advance attainment of the 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 BA YP; CAMS 53, are 

insensitive to general VOC reductions. Approximately 130 tpd of general VOC reductions 

would be needed to reduce ozone at the DRPK; CAMS 35 monitor by 1 ppb. 

Approximately 230 tpd of general VOC reductions would be needed to reduce ozone at the 

BA YP; CAMS 53 monitor by 1 ppb. Given the magnitude of VOC 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 of 53 
control measures would not advance attainment and were not RACM because even large 

reductions of generai VOC 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 

result in actual VOC reductions from existing sources. 

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 of energy efficiency 

and renewable energy measures that are increasingly being implemented. 

The commission disagrees that the suggested control measure should be implemented. The 

commission performed a thorough evaluation of additional 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 the NOx RACM analysis is 

provided in Appendix E: Reasonably Available Control Measures Analysis of this attainment 

demonstration SIP revision. In addition, as discussed in Section 5.4.3.5: Energy Efficiency 

and Renewable Energy (EEIRE) Measures of this attainment demonstration SIP revision, 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 benefit is not quantifiable. 

Kaneka cited a portion of the RACM analysis in Appendix E: Reasonably Available 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 

stimulate the market, creating incentives for further reductions in the industry regulated by 

the program. The commission acknowledges that practicality is one of the EPA's evaluation 

criterion considered during the state's RACM analysis. In the portion of the RACM 

analysis referenced by the commenter, the commission also acknowledges practicality issues 

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 

MECT program. 

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 of 53 
allowances from the stream to the calculation of uncontrolled emissions as actual emissions. 

Revised §101.394(a)(1) allows sites holding stream trades to calculate their uncontrolled 

emissions as the greater of their actual average emissions of their two highest emission years 

from 2006 through 2009 or the sum of their original existing HECT HRVOC allowance and 

the amount of the 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 of the allowance stream in tons, the difference shall be added to the uncontrolled 

emissions as actual emissions. The purchase of an allowance stream also allowed some sites 

to operate with higher emissions during the baseline emissions period. Sites that took 

advantage of allowance streams would therefore realize the benefit of the higher emissions 

through the uncontrolled emissions-based reallocation methodology. 

Flare Task Force Initiative 

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 of industrial emissions in the 

southeast quadrant of Houston, 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 ozone precursor emissions. 

As described in the RACM analysis in Appendix E: Reasonably Available Control Measure 

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 of flare 

emissions on Texas air quality and assessing the adequacy of existing flare regulations. The 

commission may consider additional control measures for flares in a future SIP revision as 

a result of its ongoing efforts to evaluate flares in Texas. 

EDF and GHASP commented that the proposed attainment demonstration SIP revision states that 

flares represent approximately 45 percent of the 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 of HR VOC 

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 

the commission is unaware of any low-NOx flare burner designs. 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 of the 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: 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 of flare emissions on Texas air 

27 of 53 
. . 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 of that 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 minimization is a viable NOx control measure. 

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 are an applicable source category for the HECT program in Harris County. 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 of flare emissions on Texas air quality and assessing the adequacy of existing Dare 

regulations. The commission may consider additional control measures for flares in a 

future SIP revision as a result of its ongoing efforts to evaluate Dares in Texas. 

The EPA commented that since HECT sources were subject to monitoring requirements, any 

unreported HR VOC emissions could only come from unmonitored sources or incomplete 

combustion of flares 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 of studying flare operations and 

is considering the option of requiring more monitoring and oversight of flare operations in the 

future. 

The TCEQ agrees that flares are a potential source of under-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 

Chapter 6: Ongoing and Future Initiatives. 

PHOTOCHEMICAL MODELING 

Support for Attainment Modeling and Weight of Evidence (WoE) Analyses 

BCCA and the Coalition submitted similar sets of detailed comments totaling over 50 pages that 

were strongly supportive of the 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 of the ongoing public participation that the TCEQ 

facilitated in the modeling process, with specific mention of the 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 been used in 1997 eight-hour ozone SIP revisions elsewhere in the United States. 

BCCA and the Coalition noted the large number of federal, 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 of the lateral boundary condition inputs for Comprehensive Air Model with 

Extension (CAMx), the specialized meteorological inputs for modeling the HGB area with Fifth 

28 of 53 
Generation 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 Coalition using 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 of high 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 of North 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 if non-typical ozone 

days are filtered out of the 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 of the EPA's Modeled Attainment Test Software (MATS), which yields slightly 

lower values at most monitors on most episode days. BCCA and the Coalition performed 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 of evidence determination provides a 

thorough and up-to-date analysis of ambient ozone and precursor levels and trends, all of which 

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 of both NOx and HR VOC precursors, which are attributed to over $2 billion worth 

of control technologies installed by industries in the 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 of the 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. 

The commission concurs with the overall conclusion drawn by BCCA and the Coalition that 

both the photochemical modeling and WoE analyses are quite robust in demonstrating that 

the HGB area will attain the 1997 eight-hour ozone standard by 2019. The commission also 

concurs that ongoing efforts should continue to improve the areas of emissions 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 of 53 
Weight of Evidence (WoE) 

CAIT, EDF, the EPA, GRASP, KIDS, SEED, and one individual commented that the WoE 

analysis did not account for the effects of favorable 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 of ozone 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, leading to lower ozone concentrations. COH requested a 

quantification of the impacts of favorable 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 still decreasing in the HGB area, 

even when the effects of meteorology 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: Wind Data 

from Houston A/dine shows the graph of interest. 

Hourly Resultant Wind Speed Profile (mph) 

82 84 86 88 90 92 94 96 98 oo 02 04 06 oa 

Year 

1 ..... 0-4 lEI 5-9 ....... >=10 m Meen I 

Figure 1: Wind Data 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 of the Ozone" Report for 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 of lower ozone in 2008. As they have noted, the frequency of high winds in 2008 is 

30 of 53 
comparable 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-hour ozone from 1998 to 2008. Since the frequency of high winds is similar 

in 1998 and 2008, the frequency of high winds cannot explain the difference between ozone 

concentrations during those two years. 

The commission contends that four extensive analyses of meteorological conditions (each of 

which includes more than just the frequency of high winds) indicate meteorological factors 

cannot explain the recent decrease in ozone. In addition, an analysis of the frequency of 

wind speed and direction will show that the period of high winds in 2008 noted by Sather 

and Snyder occurred at a time of year when high ozone usually does not occur because of 

the direction ofthe wind flow at that time of year. It will also show that the wind conditions 

were more suitable for high ozone formation in August and September of 2008 and 2009 

than in 2000 and 2004, but the number of ozone exceedance days was far lower in 2008 and 

2009. 

Chapter 5: Weight of Evidence of this attainment demonstration SIP revision contains an 

analysis from the University of Texas at Austin (UT-Austin) that shows the ozone trends 

adjusted for meteorology. Those trends show that ozone levels through 2007 are decreasing 

even with meteorological influences removed from the trends. Much of the work from UTAustin was based upon a variation of the analysis technique developed by Camalier, Cox, 

and Dolwick, which is the technique recommended by the EPA for removing the influences 

of meteorology from trend data. UT-Austin's analysis shows that when the portion of the 

ozone variation associated with meteorological factors is removed from the observed ozone 

trend, the residual trend is still downward. The presence of a strong downward trend after 

the removal of meteorological effects strongly suggests that the overall downward trend is 

related to factors other than 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. The EPA trends are shown in Figure 

2: Meteorologically Adjusted Ozone Trends in the HGB Area from 1997 through 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 

continuing through the end of the analysis period in 2008. 

31 of 53 
-.c 

8: 

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Q) 

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a 

Houston-Sugar Land--Baytown, TX 

8 ·-· 0 

o.. ~·· "":":'=',,....._.-- .. , ,.·o"--• . . .. • ,....,..~~~· .. -· ... •'o··: ... o·;i.••· ··-·o~ ·o. 

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w 1998 2000 2002 2004 2006 2008 

Adjusted for Weather Unadjusted for Weather I 

Figure 2: Meteorologically Adjusted Ozone Trends in the HGB Area from 1997 through 

2008 (Source: EPA) 

URS Corporation performed a third analysis of the effects of meteorology 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 Conducive Days and Number of Ozone Conducive Days with Ozone Greater 

Than 84 ppb 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 

been just as 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, or 2003. 

32 of 53 
Annual Number of 03-Conducive Days (OCDs) 

and the Number of OCDs with Max 03 > 84 ppb 

90 

80 

70 

~ 60 as 

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o+-~-.-.-.,-.-~~-.-.-.--r-~,--r-.-.~~.-~~ 

0 (jj N ..., .,. I() g ...... GO g: 0 0 N ..., .,. I() co 8 GO 8 (l) (l) (l) (l) g: g: 8l 8 g g 0 g 0 0 (l) (l) (l) (l) (l) (l) 

... ... ... ... ... ... ... ... ... ... N ~ N N ~ N ~ N ~ N 

Year 

, .... High Ozone Days -Total 03-Conclucive Days I 

Figure 3: Number of Ozone-Conducive Days and Number of Ozone-Conducive Days with 

Ozone Greater Than 84 ppb (Source: URS Corporation) 

A fourth analysis is presented as a response to the comment by EDF and GHASP about 

evaluating the trends in forecasted high ozone days. A possible surrogate for the number of 

ozone-conducive days during each ozone season is the number of TCEQ-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 of actual 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 of false positives (predicted exceedances that 

did not occur) and false negatives (predicted non-exceedances on days with high ozone). 

The average percent of false negative days was added to the number of forecasted ozone 

exceedance days, and the average percent of false positive days was subtracted. The biasadjusted forecasted ozone exceedance days approximately match the actual number of 

eight-hour ozone exceedance days, with the exception of 2004 and 2008. In 2004, the biasadjusted ozone exceedance forecast was much lower than the actual number of eight-hour 

ozone exceedance days. However, in 2008, the bias-adjusted forecast of ozone exceedance 

days was much higher than the actual number of eight-hour ozone exceedance days, 

indicating decreases due to factors other than 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 of forecasted ozone days in 2008 approximately matched the number in 

2006, but there were about half as many actual exceedance days in 2008 as in 2006. 

33 of53 
-

c 

::I 

0 

0 

Forecasting 8-hour ozone exceedances, Houston 

-Bias-adjusted forecasts 

100 ....-----------------------1· · · · ·Mean forecast 

--Actual forecast 

--Actual eXt:eedances 

80 

60 

40 

20 

0 +--~~--~---~---~---,-----,----,----,----~ 

2000 2001 2002 2003 2004 2005 2006 2007 2008 

Figure 4: Forecasted and Actual Eight-Hour Ozone Exceedance Days (1997 NAAQS) in the 

HGBArea 

Those four analyses of the effects of inter-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 of wind 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 of the 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 of those levels were examined by wind direction for each month from May 

to September, which represents the peak of the ozone season in the HGB area. Figure 5: 

Frequency of Morning Wind Direction and Wind Speed by Month in the HGB Area for 2000, 

2004, 2008, and 2009 compares years with similar winds and shows the number of eighthour ozone exceedances that occurred 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 of this 

attainment demonstration SIP revision, winds from that direction typically represent higher 

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 Gulf of Mexico (Sullivan, 2009; Rappenglueck et al., 2008. 

For full references of these citations, see Chapter 5: Weight of Evidence of this 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 of this attainment demonstration SIP 

revision). Findings from previous studies have indicated that low 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 of 53 
The TCEQ's wind 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 and 2009. May 2000 and 2004 were less 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 or 2004. 

• June 2008 and 2009 bad higher wind speeds than those observed in June of 2000 

and 2004; however, winds in June are mainly out of the south, which brings in clean 

air from the Gulf of Mexico. There were only three exceedance days in June of 

2000, five in June of 2005, and two in both June 2008 and June 2009. 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 

of high winds in June 2008 was unlikely to affect the number of exceedances in that 

month. 

• July winds were very similar in 2000 and 2009, but there were only two exceedance 

days in July 2009 compared to 10 exceedance days 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 

September 2000 and 13 in September 2004. September 2009 was more conducive to 

high ozone, but bad far fewer exceedances than September 2000 or 2004. 

In summary, Figure 5: Frequency of Morning Wind Direction and Wind Speed by Month in 

the HGB Area for 2000, 2004, 2008, and 2009 shows that the wind speed and direction were 

actually more conducive to ozone formation during the peak of the 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 

conducive to high ozone, during all four 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 of NOx emissions in the MECT 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 recent decreases in ozone. 

35 of 53 
8-HrOzone 

2000 H.C3B. w.\ndsj05~0 :- 190~ .. LSIJ E~ceecl~n~_Days 

~ 

.~ 

~ 

" 

t 

" 

5 

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August 

• m: 0 1~3.CF;li7A~ 1 I 11111 It 1~2~~;?~~~?2':l~::l:l!l3 

nnaonooonot234S67Haot~~46$7A90t~346 

00000000000000000000000000 

l).~tlon,d\(1 

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2004 H_G~ .'!Yi".d.S (Q~.o_:: 1900 LST) E)(C8!~an_~Days 2008 ti(3BVVinds (050~ - 19()_()_ LS.J) ~~~~da'!~ Days 

j 

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n 1 ~ :l-4!: F. 78 9 1 1 1 1 1 1 1 1 1 1 '';at':?' 2?;>?333;)3:1 

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'Mnd~d.mph 

0 <5 Iii 5-10 .10-15 [1iJ15-20 .20-25 • >25 

2009 HGB !fVinds ~()5.P~=-!!l()() 

8-HrOzone 

Exceedance Days 

3 

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n ,,~4F;~789t 1 t 111111 ,,22~'2;>~22333333 

nnnnnooooOt23<4S~7A90t~::l-4687B90t2~.45 

00000000000000000000000000 

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Figure 5: Frequency of Morning Wind Direction and Wind Speed by Month in the HGB Area for 2000, 2004, 2008, and 2009 

36 of 53 
EDF, 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 their emissions have been lower in the last few years (starting in 2007) due to 

economic influences and when demand improves it is likely their emissions will increase over the 

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 of the 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 of the 

emission inventory changes and approximate ozone reductions that have occurred over the past 

few years due to the economic downturn. COH requested a list of actions necessary to make 

these emission changes permanent and enforceable. 

The commission disagrees with these comments. Detailed analysis of actual economic data 

from the HGB area, Texas, and the refming industry along the Gulf Coast does not support 

these conjectures based on anecdotal evidence and speculation. Indeed, there is no evidence 

of an economic downturn in Texas, the HGB area, or the petrochemical industry 

specifically, prior to early 2009. None of the commenters provided any specific data to back 

up the assertions made in their comments. 

Though the national economy entered a recession beginning in the fourth quarter of 2007, 

both Texas and the HGB area continued to experience robust economic expansion during 

2007 and 2008. Only in early 2009 did either Texas or the HGB area begin to exhibit flat 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 of the Houston-Sugarland-Baytown 

area grew even faster, at 8.4 percent and 7.4 percent over those years, respectively (see 

Bureau of Economic Analysis, Regional Economic Accounts: www.bea.gov/regional/gsp/ and 

GDP by 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 

States Department of Commerce. . 

37 of 53 
$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 Economic Analysis, U.S. Department of Commerce http://www.bea.govlregional/gspl 

Figure 6: Gross Domestic Product of Texas 

Another measure of economic 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: Metro Area Business Cycle Index, Houston-Sugar/and-Baytown). The 

index, which incorporates measures of employment, real wages, and retail commerce, grew 

5.6 percent from December 2006 to December 2007, and 2.5 percent from December 2007 to 

December 2008. Through September 2009, the index is down -2.7 percent from the end of 

2008. This index, available through the first three quarters of 2009, shows that during each 

of the years 2007,2008, and 2009 to date, the HGB area generated greater economic activity 

than in any previous year on record, exceeding an index value of 245 in every month. Prior 

to 2007, the index never exceeded that value. Despite this burgeoning economic activity, the 

HGB area continued to exhibit reductions in both precursor emissions and resultant ozone 

over those three years. 

38 of 53 
October 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 of Callas 

Figure 7: Metro Area Business Cycle Index, Houston-Sugarland-Baytown 

While the overall economies of Texas and the HGB area were not impacted by the economic 

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 Selected Petroleum Related Industries). 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. Similar patterns exist for other segments of the petroleum 

industry over that period. Manufacturing of chemicals grew 9.9 percent, while 

manufacturing of plastics and rubber products increased 2.7 percent. Only manufacturing 

of petroleum and coal products declined (at a rate of -1.9 percent) from 2006 to 2007. 

39 of 53 
$billions 

$80 

$70 

$60 

$50 

$40 

$20 

$10 

-+-Oil and gas extraction {left axis) 

....,.__Petroleum and 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 Ecooomic Analysis, U.S. Department of Commerce http://wwN.bea.gollregional/gspl 

Figure 8: Gross Domestic Product of Selected Petroleum Related Industries 

While more recent data on GDP trends in the petrochemical and refining 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 reports refining activity along the Gulf Coast, 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 

Gulf Coast (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 of this variability. That measure reveals the seasonal cycles in the 

industry, as refineries ramp up production for periods of high 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 neither grown nor shrunk markedly. 

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) are excluded. 

40 of 53 
7,000 

# , 

6,000 

5,000 

4,000 

EIA reports inputs by Petroleum Adminislration lor Defense 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 AdP w hll1 · do.ela doe.gol.!dna\ Jel/hist ·.~.3-t.w him 

Figure 9: Weekly Gulf Coast (PADD 3) Crude Oil Inputs 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 of the previous year and nearly as high as in 2004, 

when they averaged 7.37 million barrels per week. Although inputs to refineries in 2008 fell 

about 3 percent after six weeks of hurricane-affected data were removed, they were back on 

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 of Refinery 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 out shortterm 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 experiencing phenomena 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 P ADD 3. 

41 of53 
100% 

95 

90 

85 

80 

75 

70 

65 

60 

Reported weekly capacity utiliza~on (light olive) 

Quadratic regression fit to weekly data (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, Energy Information Admin. 

Figure 10: Weekly Percent Utilization of Refinery Operable Capacity, PADD 3 

The EPA commented that the WoE analysis excluded a discussion of how recent emission trends 

correlate with ozone-monitoring trends. The EPA mentioned that the modeling and attainment 

guidance recommends inclusion of such 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 of its 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 Analyses for Demonstrating Attainment of Air Quality Goals for Ozone, 

PM1.5, and Regional Haze, EPA-454/B-07-002, April2007. An emission trend analysis is less 

sophisticated, less certain, and less quantitative than other analyses, and for that reason, 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 of error associated 

with estimating industrial emissions. Chapter 5: Weight of Evidence 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 

subject to the underestimates observed in the industrial emissions 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 that are included in Chapter 2: 

Emissions Inventories, Section 2. 7: Emissions Summary of the Houston-Galveston-Brazoria 

Reasonable Further Progress (RFP) State Implementation Plan Revision for the 1997 EightHour Ozone Standard (Project No. 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: RFP NOx Emission Trends from 2002 to 2018 and Figure 12: RFP 

42 of 53 
VOC Emission Trends from 2002 to 2018 present bar chart summaries of the controlled NOx 

and VOC emissions compared with 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 

ill area 

•point 

Figure 11: RFP NOx Emission Trends from 2002 to 2018 

Figure 11: RFP NOx Emission Trends from 2002 to -2018 includes each source category, 

based upon weekday emissions within the eight-county HGB area. The reductions shown 

here represent the mass of weekday NOx emissions eliminated by controls each year. 

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: RFP VOC Emission Trends from 2002 to 2018 

Figure 12: RFP VOC Emission Trends from 2002 to 2018 includes each source category, 

based upon weekday emissions within the eight-county HGB area. The reductions shown 

here represent the mass of weekday VOC emissions eliminated by controls each year. 

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 of modeling lower than 84 ppb: (l) model under-prediction 

43 of 53 
of reductions; (2) recent trend of decreasing ozone concentrations; and (3) voluntary and other 

control measures that may not be 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 Other Analyses for Demonstrating Attainment of 

Air Quality Goals for Ozone, PM2.5, and Regional Haze, Section 2.3: What Does A 

Recommended Supplemental Analysis/Weight Of Evidence 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 attainment test. Such analyses are instrumental in guiding the conduct of an air quality 

modeling application. Sometimes, the results of corroboratory analyses may be used in a 

WoE determination to show that attainment is likely despite modeled results which may be 

inconclusive." Table 2.1: Guidelines for Weight of Evidence Determinations on page 17 

states that a WoE demonstration should be conducted when the future ozone design values 

fall in the range of 82 to 87 ppb. Due to the inevitable uncertainty that exists with respect to 

emission estimates, meteorological inputs, and chemical mechanisms, Section 7.1: What 

Types of Additional Analyses Should Be Completed as Part of the Attainment Demonstration? 

on page 105 says "EPA believes that weight of evidence determinations can be used in some 

cases to demonstrate attainment conclusions that differ from the conclusions of the model 

attainment test." 

TCC commented that it supports the WoE section but recommends that it be further strengthened 

to include the full range of 2007-2009 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 Bay land Park monitor design value of 84 ppb in contrast to the 2018 projected design 

value of 86.9 ppb. 

The commission has updated Chapter 5: Weight of Evidence of this attainment 

demonstration SIP revision 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 are inexact and precision cannot be expected. 

Emissions Projections 

The EPA commented that the attainment section did not include use of the MATS tool. For the 

monitored attainment test, the EPA stated that MATS should be used to indicate photochemical 

model predictions for areas outside of each monitor's grid cell array. 

The EPA developed MATS to provide regulatory entities conducting SIP reviSion 

photochemical modeling with a tool for applying the attainment test. 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 

areas where future-year design values are predicted to be greater than the NAAQS. 

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-hour ozone standard (e.g., Dallas-Fort Worth; May 2007) with submission dates prior 

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 of 53 
advantages, including the advantage that they can be more easily integrated into 

photochemical modeling output processing streams. For example, MATS requires input in 

latitude and longitude for monitor coordinates, while the TCEQ's procedures work directly 

with the Lambert Conformal Projection (LCP) monitoring coordinates used in our 

photochemical modeling applications. Also, MATS cannot easily handle multi-year baseline 

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 more familiar kriging technique. For these reasons, MATS was not used for either 

the monitored attainment test or the unmonitored area analysis. 

On February 18, 2009, at the SETPMTC meeting attended by EPA Region 6 staff, the 

TCEQ presented a comparison of2018 future-year eight-hour ozone design values using the 

EPA's MATS and the TCEQ's software procedures 

(http://www. tceg .state. tx. us/ assets/pub lie/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 of Air Quality Planning and Standards staff, and the TCEQ photochemical modeling 

staff, the comparison of the two methods was discussed as well as the planned use of the 

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 

the monitored attainment test. 

Although the comparison of the two methods focused primarily on the application of the 

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 that have a baseline design 

value (DVs) and a relative response factor (RRF) denominator greater than or equal to 85 

ppb mitigates the need to conduct an unmonitored area analysis for the area represented by 

the non-regulatory monitor. The relatively large number of monitors, both regulatory and 

non-regulatory, industry-sponsored, deployed in the HGB area provides adequate coverage, 

such that there are no areas outside of a monitor's 7x7 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 of MATS is a part of EPA's guidance, 

not rule or statute. Since the TCEQ has developed a less resource-intensive yet consistent 

tool, the commission contends that it is not necessary to conduct a duplicative exercise with 

the limited resources and time constraints of this SIP revision. Due to these constraints, the 

re-analysis uses the kriging method and not MATS. lfnecessary, a MATS analysis could be 

provided at a later date. 

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 DV F greater than the NAAQS that fall outside the 7x7 grid cell array 

around the WALV; CAMS 617 non-regulatory, industry-sponsored monitor. However, 

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these 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 appropriate for 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 RRF of0.954 yielding a DVF less than 85 ppb. Applying the attainment test at the BYWC 

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 - HGB 03 DV 5i1e 200MOoe 711.7 210m Cell> • HGBAQ Slli 200!1120oe 

[::=J HG 2x:J<m C3-a 

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 

46 of 53 
EDF and GHASP commented that VOC emissions will steadily rise out to 2018, specifically 

citing Table 3-13: Summary of2006 Baseline and 2018 Future Base, and 2018 Control Strategy 

Anthropogenic Modeling Emissions for HGB on page 3-25 of the proposed attainment 

demonstration SIP revision. EDF and GHASP requested a justification for a roughly I 00 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 of 2006 Baseline, 2018 Future 

Year, and 2018 Control Strategy Anthropogenic Modeling Emissions for HGB of the proposed 

attainment demonstration SIP revision of208.34 tpd in 2006 to 306.77 tpd 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 year were 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 of activity data were used: (1) the Dallas Federal Reserve Bank's Texas 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 of the 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 manufacturing facility). 

Both the TIPI and the REMI data sets were used with EGAS version 5.0 to derive two sets 

of emission 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: Photochemical Modeling of this attainment demonstration SIP 

revision, 2018 area source emissions, including VOC emissions, were estimated by applying 

the Texas-specific REMI-EGAS growth factors to the 2005 TexAER database. However, no 

growth or control factors were applied to the flash emissions, which are now subject to the 

storage vessel 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 

overestimates the future-year area source VOC emissions. 

Also, as reported in Chapter 3: Photochemical Modeling of this attainment demonstration 

SIP revision, 2018 point source emissions, including VOC, were estimated by applying the 

larger of the TIPI-EGAS, REMI-EGAS growth factors, or banked 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 of which 

would require offsets. Considering the recent decreasing trend in reported point source 

VOC emissions (Figure 14: HGB Point Source VOC and NOx Emission Trends From 2003 

through 2007), selecting the larger of the growth factors may overestimate the growth in 

point source emissions by 2018. 

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HGB Point Source VOC and NOx Emissions Trend 2003 - 2007 

2003 2004 2005 2008 2007 

Emission Reporting Year 

Figure 14: HGB Point Source VOC 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 tpd compared to 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; it is not a result of a 

relaxation or removal of a SIP requirement. Therefore, the increase is not backsliding 

under the one-hour ozone standard. 

A conservative estimate of emissions 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 

percent per year. 

Because the executive director has committed to a mid-course review, VOC emissions and 

their growth may be reevaluated at that time, if appropriate, to assess the validity of growth 

assumptions used within this SIP revision. 

Emissions Reconciliation 

The EPA commented that the TCEQ's method of reconciling reported emissions ofHRVOC with 

ambient concentrations adds 10 tpd of emissions to Harris County, using a technique derived 

from the PSCF- The EPA requested confirmation that 6 tpd of the 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 

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demonstration 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 

additional 6 tpd is not removed. 

The EPA commented that the PSCF-based emission reconciliation improves model performance 

but that even with the added HR VOC 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 of modeled and measured concentrations; and (2) using a multi-year annual 

mean in the reconciliation. 

The commission agrees that the emissions reconciliation improves model performance and 

that, in some cases, the model does not simulate the highest observed one-hour ozone 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 of routine 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 of the emissions reconciliation. In fact, the PSCF adjustment was 

applied separately for 2005 and 2006. 

Retrospective Modeling 

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 it does for any set 

of emission estimates. Both of the inventories were reconciled with observational data so 

that the emission inputs used in the retrospective modeling analyses reflect available 

adjusted inventories. The commission asserts that the retrospective 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 but rather provides flexibility to states in how to carry out this kind 

of analysis. 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 RRF calculation. 

Figure 15: Modeled and Observed Response 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 Weekend Emission Reductions shows how the model and observations respond 

49 of 53 
to 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 

weaker responses by the model than observed. Another example of how photochemical grid 

models have underestimated the response to emission reductions can be found in a study by 

EPA scientist Alice Gilliland and colleagues, published in 2008 in Atmospheric Environment. 

In that study, the authors showed that both relative and absolute model response to the 

NOx SIP call emission reductions, published on October 27, 1998, in the Federal Register (63 

FR 57356), are less than the observed responses. For the 2005 version of the 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 of Evidence, 

Section 5.2: Corroborative Analysis: Modeling of this attainment demonstration SIP 

revision is in agreement with other studies showing that modeled ozone response to emission 

controls is underestimated. 

110 

105 

.Q 100 c. 

c. 

> c 95 

(I) 

c 

0 

N 90 0 

CD 

0 

0 

N 85 

80 

75 

75 

Retrospective analysis, response to emission 

changes from 2000 to 2006 

y = 0.8501 X + 2.6019 

R2 = 0.9026 

' • Modeled 

• Observed 

-Linear (Observed) 

- Linear (Modeled) 1 

y = 0. 7206x + 12.662 

R2 = 0.3995 

80 85 90 95 100 105 110 

2000 Ozone DV, ppb 

Figure 15: Modeled and Observed Response to Emission Changes between 2000 and 2006 

In Figure 15: Modeled and Observed Response to Emission Changes Between 2000 and 2006, 

each point represents the values for a particular monitoring site. The slopes of the response 

lines show the degree of ozone decrease from 2000 through 2006. 

50 of 53 
80 

70 

a 60 

~ 

"" c 

:I 50 rn 

40 

30 

90 

80 

70 

a 

Observed and Modeled weekend effect, 

8-hour ozone 

40 50 60 70 80 

Wednesday 8-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 • Obs Sun >50ppb 

--1:11ine c 

ri! 

50 

40 

30 V···· 

30 

········· -10% 

-20% 

50 70 90 

Wednesday 1-hr 03 

Observed and Modeled weekend effect, 

8-hour ozone 

80..----------------,( 

70 

a eo 

~ 

~50 

40 

30 

90 

80 

70 ... 

0 

~ 60 

~ 50 

40 

30 

30 

40 50 60 70 80 

Wednesday 8-hr 03 

• Mod Saturday 

• Obs Saturday 

• Obs Sat >50ppb 

--1:1 ine 

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

-20% 

Observed and Modeled weekend effect, 

1-hour ozone 

50 70 90 

Wednesday 1-hr 03 

• Mod Saturday 

• Obs Saturday 

• Ols Sat >50ppb 

--1:1 ine 

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

-20% 

Figure 16: Modeled and Observed Response to 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 

peak eight-hour ozone over 50 ppb. The latter values are more comparable to the modeled 

days, since the modeled days have targeted high ozone days. The green triangles show a 

greater degree of decrease 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 Emissions Reductions 

COH commented that the TCEQ should focus on reductions of air toxic emissions in the ambient 

atmosphere. COH stated that reducing air toxic levels will help in reducing ozone formation. 

51 of53 
The TCEQ has made great strides in driving industrial reductions of air toxics over the 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 butadiene is of particular toxic concern. Though the rules were put in 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 of overall 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. For example, under the contingency plan description 

in Chapter 4: Control Strategies and Required Elements, 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. If finalized, 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 

air toxics and ozone." 

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, and permitting, to encourage and promote reductions of toxic air pollution. 

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 accompanying PM reductions. 

The commission concurs that some of the 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. The commission made no changes in response to this comment. 

Photochemical Modeling Improvements 

COH requested a listing of the changes and adjustments that need to be made to local air quality 

models so that they better reflect actual ozone measurements being taken in the area. 

Photochemical air quality modeling tools are constantly being improved as steady 

incremental progress is made in the areas of emissions 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 of this 

attainment demonstration SIP revision for a discussion of the improvements that have been 

52 of 53 
made 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. 

For example, the Weather Research and Forecasting (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 of on-road mobile source emissions. 

Chapter 6: Ongoing and Future Initiatives of this 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 

March 2010, with final results expected by the summer 2010. 

Another major effort more fully discussed in Chapter 6: Ongoing and Future Initiatives of 

this attainment demonstration SIP revision is the Study of Houston Atmospheric Radical 

Precursors (SHARP). That extensive field study of ozone 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 of the flare and SHARP studies will be incorporated into air quality 

modeling efforts. 

Inclusion of Power Plant Emissions Outside ofthe HGB Area 

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 of this attainment demonstration 

SIP revision states "Newly-permitted ARD [Acid Rain database] sources were limited to the 

[Texas] Clean Air Interstate Rule (CAIR) 9.5 percent set-aside for growth." Appendix B: 

Emissions Modeling for 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 of November 2009 were included in the modeling and are specifically listed in 

Appendix B: Emissions Modeling for the HGB Attainment Demonstration SIP, Section 2.3: 

2018 Future Year Point Source Modeling Emissions Development. The list of EGUs 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. The commission made no changes in response to this comment. 

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