Bryan W. Shaw, Ph.D., P.E., Chairman 

Toby Baker, Commissioner 

Zak Coval', Commissioner 

Richard A. Hyde, P .E., Executive Director 

TEXAS COMMISSION ON ENVIRONMENTAL QUALITY 

Mr. Ron Curry 

Administrator 

PI'Otecting Texas by Reducing and P1-eventing Pollution 

July 22, 2014 

Environmental Protection Agency, Region 6 

Fountain Place 121h Floor, Suite 1200 

1445 Ross Avenue 

Dallas, Texas 75202-2733 

Subject: Redesignation Substitute Report for tbe Houston-Galveston-Brazoria (HGB) One-Hour 

Ozone Standard Nonattainment Area 

Dear Mr. Curry: 

The Texas Commission on Environmental Quality (TCEQ) submits the enclosed Redesignation 

Substitute Report for the Houston-Galveston-Brazoria One-Hour Ozone Standard 

Nonattainment Area for your consideration and concurrence that the HGB area, which includes 

Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller Counties, 

has met the requirements for the one-hour ozone N a tiona! Ambient Air Quality Standard 

(NAAQS). This redesignation substitute report includes: monitoring data showing attainment 

of the revoked one-hour ozone NAAQS; a showing that attainment was due to permanent and 

enforceable emissions reductions; and a demonstration that the area can maintain the standard 

through 2026 based on emission inventory trends and projections of future emissions. 

The United States Environmental Protection Agency's (EPA) Implementation of the 2008 

National Ambient Air Quality Standards for Ozone: State Implementation Plan Requirements; 

Proposed Rule (zooS ozone standard SIP requirements rule) published in the June 6, 2013 

Federal Register (78 FR 34178), includes a mechanism for lifting anti-backsliding obligations 

under a revoked ozone NAAQS. According to tbe proposal, a state can provide a showing, 

termed a "redesignation substitute," based on Federal Clean Air Act (FCAA), §107(d)(3)(E) 

redesignation criteria to demonstrate that an area qualifies for lifting anti-backsliding 

obligations under a revoked standard. The enclosed report fulfills the requirements for a 

redesignation substitute, as described in the proposed zooS ozone standard SIP requirements 

rule, for the HGB one-hour ozone nonattainment area. 

The 2013 expected exceedances of the 0.12 parts per million one-hour ozone NAAQS for each 

monitor in tbe HGB area is less than 1.0 days per year and therefore the area is attaining the 

one-hour ozone standard. On March 7, 2014, the TCEQ submitted to the EPA a certification 

evaluation and concurrence report for early certification of 2013 ambient air monitoring data for 

ozone along with a request for a finding of attainment for the HGB area for the revoked onehour ozone NAAQS. 

While tbe proposed 2008 ozone standard SIP requirements rule is not expected to be finalized 

until this fall, the TCEQ submits this report to you now to facilitate your review of the elements 

described in FCAA, §107(d)(3)(E) as soon as possible. 

P.O. Box13087 • Austin, Texas78711-3087 • 512-239-1000 • tceq.texas.gov 

How is our customer service? tceq.texas.govjcustomersurvey 

printecl on recyclecl paper using vcgctable"IJased mk 
Mr. Curry 

Page 2 

July 22, 2014 

If you have questions or need additional information please contact David Brymer, Director of 

the Air Quality Division, at (512) 239-1725. 

Sincerely, 

Richard A. Hyde, P.E., Executive Director 

Texas Commission on Environmental Quality 

RH/DB/lb 

Enclosure: Redesignation Substitute Report for the Houston-Galveston-Brazoria One-Hour 

Ozone Standard Nonattainment Area 
REDESIGNATION SUBSTITUTE REPORT FOR THE

HOUSTON-GALVESTON-BRAZORIA ONE-HOUR OZONE STANDARD 

NONATTAINMENT AREA

TEXAS COMMISSION ON ENVIRONMENTAL QUALITY

P.O. BOX 13087

AUSTIN, TEXAS 78711-3087
This page intentionally left blank
Page 1

SECTION 1: GENERAL

1.1 Purpose of this Redesignation Substitute Report

This redesignation substitute (RS) report for the Houston-Galveston-Brazoria (HGB) one-hour 

ozone nonattainment area fulfills the requirements for an RS, as described in the United States 

Environmental Protection Agency’s (EPA) Implementation of the 2008 National Ambient Air 

Quality Standards for Ozone: State Implementation Plan Requirements; Proposed Rule

(proposed 2008 ozone standard SIP requirements rule), published in the June 6, 2013 Federal 

Register (78 FR 34178). Data for 2011 through 2013 show that the HGB area is monitoring 

attainment of the one-hour ozone National Ambient Air Quality Standard (NAAQS). The HGB 

area includes Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and 

Waller Counties. On March 7, 2014, the Texas Commission on Environmental Quality (TCEQ)

submitted to the EPA certified ambient air monitoring data along with a request for a finding of 

attainment for the HGB area for the revoked one-hour ozone NAAQS.

The EPA’s proposed 2008 ozone standard SIP requirements rule includes a mechanism for 

lifting anti-backsliding obligations under a revoked ozone NAAQS. According to the EPA’s

proposed 2008 ozone standard SIP requirements rule, a state can provide a showing, termed a 

“redesignation substitute,” based on Federal Clean Air Act (FCAA), §107(d)(3)(E) redesignation 

criteria to demonstrate that an area qualifies for lifting anti-backsliding obligations under a 

revoked standard.

This RS report satisfies the EPA’s proposed requirements to lift anti-backsliding obligations for 

the revoked one-hour ozone NAAQS by ensuring that specific redesignation requirements are

met for the HGB area under the revoked standard. Data for 2011 through 2013 demonstrate that 

the HGB area is monitoring attainment of the one-hour ozone NAAQS, and attainment is due to 

permanent and enforceable emission reductions. This RS report provides verification of 

continued attainment of the one-hour ozone NAAQS through 2026 via emissions inventory (EI) 

trends and future emission projections.

According to the EPA’s proposed 2008 ozone standard SIP requirements rule, this RS report is

based on FCAA redesignation criteria with the exception of certain elements. This report

includes the following elements.

Monitoring data showing attainment of the revoked one-hour ozone NAAQS

Section 2: Air Quality Data includes monitoring network and reporting requirements as well as

ozone data and trend analyses. The 2013 expected number of exceedances of the 0.12 parts per 

million (ppm) one-hour ozone NAAQS in the HGB area is 0.7 days per year. Ozone 

concentrations have decreased dramatically in the HGB area since the 1990s. Examination of 

the trends in one-hour ozone design values and the number of expected exceedances reveals 

substantial downward trends.

Showing that attainment was due to permanent and enforceable emissions reductions

Section 3: Permanent and Enforceable Emissions Reductions identifies permanent and 

enforceable control measures that have resulted in reductions in nitrogen oxides (NOX) and 

volatile organic compounds (VOC) emissions, and air quality improvements in the HGB onehour ozone nonattainment area. The 30 Texas Administrative Code (TAC) Chapter 115: Control 

of Air Pollution from Volatile Organic Compounds and 30 TAC Chapter 117: Control of Air 

Pollution from Nitrogen Compounds regulations along with implementation of the Mass 

Emissions Cap and Trade (MECT) program and the Highly-Reactive Volatile Organic 

Compounds Emissions Cap and Trade (HECT) program have significantly reduced overall ozone 

precursor emissions at both major and minor (point and area) stationary sources in the HGB 
Page 2

ozone nonattainment area. Innovative emissions reduction programs such as the Texas 

Emissions Reduction Plan (TERP) and the AirCheckTexas Drive a Clean Machine program have 

reduced mobile source emissions, the primary source of NOX emissions in the HGB area. The 

HGB area has attained the one-hour ozone NAAQS as the result of implemented federal, state, 

and local controls. These enforceable measures will remain in place to ensure continued 

maintenance of the one-hour ozone NAAQS in the HGB area.

Demonstration that the area can maintain the standard over the next 10 years

Section 4: Maintenance Demonstration provides EI trends, the 2011 attainment inventory, and 

future emissions and verification of continued attainment of the one-hour ozone standard 

through 2026. Trend analysis using the 2026 future-year emissions shows an overall decrease of 

176.40 tons per day (tpd) in combined NOX and VOC emissions for the HGB area. This net 

change includes a projected 18.49 tpd decrease in VOC and a 157.91 tpd decrease in NOX from 

2011 to 2026. Based on emissions projections and previous photochemical analysis, continued 

attainment of the one-hour ozone standard is shown for the HGB area through 2026.

1.2 One-Hour Ozone NAAQS History

In 1971, the EPA established the 0.08 ppm one-hour ozone NAAQS (36 FR 8186). The EPA 

revised the one-hour ozone standard to 0.12 ppm or 124 parts per billion (ppb) in 1979 (44 FR 

4202). In 1990, the eight-county HGB one-hour ozone nonattainment area, defined as Brazoria, 

Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller Counties, was 

classified as severe 17 according to the FCAA. At that time, the FCAA also required submission 

of a SIP revision describing actions to be taken to reduce NOX and VOC by November 1996. 

Before that deadline, however, modeling showed uncertainties in the actual impact that NOX

reductions would have on ground-level ozone formation. The HGB area was therefore granted a 

temporary exemption until December 1997 to fulfill its NOX control requirements after which 

the HGB area was given a new attainment deadline of November 15, 2007. In 1997, the EPA 

promulgated the more stringent eight-hour ozone NAAQS.

The HGB One-Hour Ozone Attainment Demonstration and Post-1999 Rate-of-Progress (ROP) 

SIP Revision was adopted on December 6, 2000. The attainment demonstration portion of the 

submittal contained numerous air pollution control measures resulting in an overall 90%

reduction in point source NOX emissions. Despite this reduction, a modeling analysis included 

in the SIP revision indicated a shortfall in NOX emissions reductions necessary for an 

approvable attainment demonstration. To address this shortfall, the SIP revision also contained 

enforceable commitments to implement further measures in support of the attainment 

demonstration and to submit a mid-course review (MCR) to the EPA. The ROP plan portion of 

the December 2000 SIP revision submittal provided emissions inventories, ROP analyses for 

milestone years 2002, 2005, and 2007, and motor vehicle emissions budgets (MVEB) for NOX

and VOC.

On September 26, 2001, the Follow-Up One-Hour Ozone Attainment Demonstration and ROP 

SIP Revision was adopted. This revision incorporated changes to several control strategies and

detailed the MCR process, which described how the state would fulfill the commitment to obtain 

the additional emission reductions necessary to address the remainder of the emission 

reductions shortfall and demonstrate attainment of the one-hour ozone standard in the HGB 

area. On November 14, 2001, the EPA published approval of both the December 2000 and 

September 2001 SIP revisions (66 FR 57159).

The Business Coalition for Clean Air Appeal Group and several regulated companies challenged 

the December 2000 HGB SIP revision and the 90% NOX reduction requirement from stationary 
Page 3

sources. In 2001, the Texas Natural Resource Conservation Commission, now the TCEQ, was

required to perform an independent and thorough analysis of the causes of rapid ozone 

formation events and to identify potential mitigating measures not yet included in the HGB 

attainment demonstration.

On December 13, 2002, the commission adopted the One-Hour Ozone Attainment 

Demonstration Follow-Up SIP Revision that addressed the agreements contained in the June 8, 

2001 consent order. This SIP revision also incorporated energy efficiency measures and the 

TERP protocol. The December 2002 SIP revision replaced 10% of industrial point source NOX

emissions reductions with industrial source, highly reactive volatile organic compounds 

(HRVOC) controls. The result was an industrial source ozone control strategy that relied on an 

80% reduction in NOX emissions through 30 TAC Chapter 117 and the MECT program, and 

HRVOC rules in 30 TAC Chapter 115 that better quantified and reduced emissions of HRVOC 

from four key industrial sources: fugitives, flares, process vents, and cooling tower heat 

exchange systems.

On October 27, 2004, the commission adopted the HGB One-Hour Ozone Post-1999 ROP SIP 

Revision. This revision provided updated emissions inventories and ROP analyses for milestone 

years 2002, 2005, and 2007 and revised MVEB for the HGB area based on new models for 

estimating on-road and non-road mobile emissions sources. This SIP revision replaced the 

previous versions of the Post-1999 ROP that the EPA approved in November 2001. On February 

14, 2005, the EPA published approval of this SIP revision (70 FR 7407).

On December 1, 2004, the commission adopted the HGB One-Hour Ozone Attainment 

Demonstration MCR SIP Revision reflecting a strategy based on reducing NOX and point source 

HRVOC rather than NOX alone. This SIP revision changed a number of NOX control strategies 

and added the HRVOC emission reduction requirements. The results of photochemical 

modeling and technical documentation included in this SIP revision demonstrated attainment 

of the one-hour ozone standard by the November 15, 2007 deadline. The one-hour ozone SIP 

revision commitments addressed in this revision included: completion of a one-hour ozone 

MCR; adoption of measures sufficient to address the shortfall in NOX reductions; adoption of 

measures sufficient to demonstrate attainment; MVEB updates using EPA’s MOBILE6 model; 

and changes to voluntary mobile emissions reduction program measures.

On September 6, 2006, the EPA published approval of the HGB area’s one-hour ozone 

attainment demonstration and associated rules (71 FR 52656). The approval was published in 

six parts covering the rules for the control of HRVOC, the one-hour ozone attainment plan, the 

HECT program for HRVOC, the MECT program for NOX, the Emissions Credit Banking and 

Trading Program, and the Discrete Emissions Credit Banking and Trading Program.

The HGB area failed to attain the one-hour ozone standard by the November 15, 2007 

attainment deadline, and the EPA published a failure-to-attain determination on June 19, 2012

based on air quality monitoring data for 2005 through 2007 (77 FR 36400). Although the EPA 

revoked the one-hour ozone NAAQS in June 2005, former one-hour ozone nonattainment areas 

remain subject to certain anti-backsliding requirements. The three anti-backsliding 

requirements that apply to the HGB severe one-hour ozone nonattainment area are contingency 

measures, new source review (NSR) permitting requirements for severe nonattainment areas, 
Page 4

and a penalty fee provision1

. The anti-backsliding requirement for contingency measures under 

FCAA, §172(c)(9) and §182(c)(9) has already been achieved in the HGB area2

, and a final 

determination of failure to attain does not trigger additional emission reductions. The NSR 

permitting requirements would apply for the one-hour ozone NAAQS until the RS request is 

approved by the EPA, after which Prevention of Significant Deterioration permitting 

requirements would apply. However, because the HGB area is also classified as severe

nonattainment for the 1997 eight-hour ozone NAAQS, severe area NSR permitting requirements 

would still apply whether or not this RS is approved by the EPA. The anti-backsliding 

requirement to implement a penalty fee program under FCAA, §182(d)(3) and §185 was 

triggered with the EPA’s failure-to-attain determination, and it continues to apply to the HGB 

one-hour ozone nonattainment area unless the obligation is terminated. On May 22, 2013, the 

commission adopted rules under 30 TAC Chapter 101: General Air Quality Rules, Subchapter B 

to implement these FCAA provisions.

SECTION 2: AIR QUALITY DATA

2.1 Monitoring Network and Reporting Requirements

The method chosen to verify continued attainment of the one-hour ozone National Ambient Air 

Quality Standard (NAAQS) is the ambient air quality monitoring network, which will be used to 

track changes in the ambient air quality.

The Houston-Galveston-Brazoria (HGB) area monitoring network in 2014 consists of 21 

regulatory ambient air ozone monitors located in Brazoria, Galveston, Harris, and Montgomery 

Counties, Texas. The City of Houston operates eight of the monitors: Clinton 

(C403/C113/C304); Houston North Wayside (C405); Houston Monroe (C406); Lang (C408);

Houston Croquet (C409); Houston Westhollow (C410); Houston Texas Avenue (C411); and Park 

Place (C416). The Texas Commission on Environmental Quality (TCEQ) operates the remaining 

13 ozone monitors: Houston East (C1); Houston Aldine (C8/C108/C150); Channelview 

(C15/C115); Northwest Harris County (C26), Houston Deer Park #2 (C35/C139), Seabrook 

Friendship Park (C45); Houston Bayland Park (C53); Conroe Relocated (C78); Manvel Croix 

Park (C84); Lynchburg Ferry (C1015); Lake Jackson (C1016); Baytown Garth (C1017); and 

Galveston 99th Street (C1034).

The monitors are managed in accordance with 40 Code of Federal Regulations (CFR) Part 58 to 

verify the attainment status of the area. The TCEQ commits to keep in operation an appropriate 

air monitoring network in the HGB area and will continue to work with the EPA through the air 

monitoring network review process, as required by 40 CFR Part 58, to determine: 1) the 

adequacy of the ozone monitoring network; 2) if additional monitoring is needed; and 3) when 

monitoring can be discontinued. Air monitoring data from these monitors will continue to be 

quality assured according to the requirements in EPA’s regulations until the end of the 

maintenance period (2026) and reported to the EPA on the schedule required by 40 CFR Part 

58.

 1 South Coast v. EPA, 472 F.3d 882 (D.C. Cir. 2006), directed the EPA to provide one-hour ozone NAAQS 

anti-backsliding requirements for nonattainment new source review, §185 fees, and §172(c)(9) and 

§182(c)(9) contingency measures for failure to attain the one-hour ozone NAAQS by the applicable 

attainment date or to make reasonable further progress toward attainment of that standard.

2 The EPA-approved one-hour ozone attainment demonstration and ROP SIP revisions included 

contingency measures (71 FR 52670, 70 FR 7407, 66 FR 57195, and 66 FR 20750).
Page 5

2.2 Ozone Data

The rest of this section provides an analysis of air quality observational data in the HGB area.

While the ozone NAAQS is expressed in units of parts per million (ppm), the familiar convention 

of expressing concentrations in parts per billion (ppb) is also used in this section. Data for ozone 

and nitrogen oxides (NOX) were retrieved from United States Environmental Protection 

Agency’s (EPA) Air Quality System database, and VOC data were retrieved from TCEQ’s 

automated gas chromatograph (auto-GC) database. Analyses of ozone data from federal 

reference method monitors and federal equivalent method monitors, those used by the EPA to 

compare to the NAAQS, are included in this section.

2.3 Ozone Trend Analysis

Trends in ozone are used to demonstrate the substantial progress the HGB area has made in 

improving air quality. The downward trend in design values for the one-hour ozone NAAQS in 

the HGB area is seen clearly in Figure 2-1: One-Hour Ozone Design Values for the HGB Area. In 

both 2011 and 2012, the one-hour design value for the HGB area was 0.13 ppm (or 125 ppb), 

which is just above the 0.12 ppm one-hour ozone NAAQS. In 2013, however, the HGB area 

monitored attainment with a design value of 0.12 ppm (or 121 ppb). The design value for each 

monitor is the fourth-highest concentration over a three-year period, and the design value for 

the area is the highest of the design values from the individual monitors within the area. The 

one-hour ozone design value in the HGB area has shown large decreases over the past 24 years; 

the design value of 121 ppb achieved in 2013 represents a 45% decrease from the 1990 design 

value of 220 ppb.

Figure 2-1: One-Hour Ozone Design Values for the HGB Area
Page 6

For the one-hour ozone NAAQS, the design value was used to determine the classification of a 

nonattainment area but was not used for designating an area as attainment or otherwise. 

Designation is based on the maximum number of expected exceedances over all the monitors in 

an area3

. To show that the HGB area no longer violates the one-hour ozone NAAQS, the 

remainder of this section will be based on expected exceedances, calculated as per 40 CFR Part 

50, Appendix H. 

The expected number of exceedances of record in a metropolitan area is the maximum expected 

number of exceedances of all the area’s regulatory monitors’ individual expected number of 

exceedances. Because ozone concentrations vary spatially, it is also prudent to investigate trends 

at all regulatory monitors in an area. Table 2-1: One-Hour Ozone Expected Exceedances by 

Monitor contains one-hour ozone expected number of exceedances at all regulatory monitors in 

the HGB area from 2000 through 2013. More monitors than those listed in Table 2-1 operate in 

the HGB area, but expected number of exceedances at those additional monitors are not 

appropriate for compliance determinations because the monitors’ data do not meet EPA’s 

quality assurance criteria and cannot be used for regulatory purposes. In 2013, all monitors in 

the HGB area had expected exceedances less than the threshold of 1.0 per year and only one 

monitor in the HGB area, the Houston East monitor (C1), had more than 1.0 expected 

exceedance in 2011 and 2012.

 3 The expected exceedances for a monitor is defined as the number of exceedances that occurred in the 

calendar year plus an increment that accounts for missing data, averaged across three consecutive years 

(for example, expected exceedances for 2013 is averaged across 2011, 2012, and 2013). The increment is 

calculated by finding the number of days without an associated ozone measurement that may not be 

assumed to be less than the standard, multiplied by the number of observed exceedances, then divided by 

the number of observations. This is done for each year and then averaged across three years to get the 

expected exceedances for that individual monitor. Note that unlike the calculation for expected 

exceedances, design values are not adjusted for data completeness.
Page 7

Table 2-1: One-Hour Ozone Expected Exceedances by Monitor

Site Name

20002001200220032004200520062007200820092010201120122013

Manvel Croix 

Park C84 1.7 2.0 2.7 2.7 3.4 2.1 1.4 0.7 0.3 0.7 0.7 0.7

Houston East 

C1 10.0 9.5 7.4 6.0 4.7 3.4 1.7 0.7 0.7 0.0 0.7 1.3 1.3 0.7

Northwest 

Harris County 

C26

7.1 6.8 5.2 4.1 2.4 1.7 1.7 2.0 1.3 1.4 0.7 0.7 0.7 0.7

Houston 

Bayland Park 

C53

14.4 12.2 7.1 6.4 4.4 5.4 5.1 3.7 1.7 0.3 0.3 0.7 0.7 0.7

Houston 

Monroe C406 8.2 7.2 5.4 4.4 3.4 3.4 3.4 2.7 1.0 0.3 0.3 0.3 0.7 0.7

Seabrook 

Friendship 

Park C45

3.7 5.4 4.0 3.7 2.7 2.0 1.0 0.3 0.0 0.0 0.3 0.7

Galveston 99th 

St C1034 0.0 0.0 0.0 0.0 0.4 0.4 0.4

Park Place 

C416 2.7 3.4 1.0 1.3 0.7 0.7 0.3

Houston 

Aldine 

C8/C108/C150

11.6 10.9 8.4 5.0 3.0 3.4 1.4 0.7 0.0 0.0 0.3 0.7 0.7 0.3

Houston 

Croquet C409 10.9 8.3 5.2 4.4 4.3 4.0 3.0 1.7 0.3 0.3 0.3 0.3 0.3 0.3

Houston Texas 

Avenue C411 2.2 4.9 3.7 3.7 1.4 0.7 0.7 0.7 0.3 0.3 0.3 0.3

Clinton 

C403/C113/C3

04

10.2 9.9 6.2 5.5 3.7 3.1 1.0 0.3 0.0 0.3 0.3 0.3 0.3 0.3

Houston North 

Wayside C405 9.3 6.9 4.8 2.4 2.7 2.4 0.7 0.0 0.0 0.0 0.0 0.3 0.3 0.3

Houston 

Regional Office 

C81

5.4 6.5 5.1 3.1 3.0 2.0 1.7 0.7 0.0 0.0 0.3 0.3 0.3

Channelview 

C15/C115 2.5 4.5 4.3 3.3 2.0 1.7 1.0 0.7 0.7 0.7 0.4 0.0

Lynchburg 

Ferry C1015 6.8 8.8 4.7 2.4 0.3 0.0 0.4 0.4 0.4 0.0

Houston Deer 

Park 2 

C35/C139

11.6 11.2 8.2 6.2 5.8 5.2 4.1 2.4 1.7 1.1 1.1 0.7 0.0 0.0

Lang C408 6.2 4.5 3.9 2.4 2.7 2.0 1.3 0.0 0.0 0.3 0.3 0.3 0.0 0.0
Page 8

Site Name

20002001200220032004200520062007200820092010201120122013

Lake Jackson 

C1016 0.6 0.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Houston 

Westhollow 

C410

7.7 7.9 4.5 3.4 2.1 1.7 2.4 2.0 1.7 0.3 0.0 0.0 0.0 0.0

Conroe 

Relocated C78 0.3 1.0 1.3 1.3 1.3 1.0 0.7 0.0 0.0 0.0 0.0 0.0

Galveston 

Airport 

C34/C109

5.7 3.7 1.4 1.1 1.4 1.4 0.3 0.0

Texas City C10 4.4 3.4 1.0 0.3 0.3

Clute C11 2.4 2.0 1.4 1.5

Conroe C65 3.1 4.0 2.6

Houston 

Crawford C407 8.4 4.4

Number of 

monitors 16 17 20 20 21 20 20 22 21 21 21 21 21 21

Figure 2-2: One-Hour Ozone Expected Exceedance Statistics for All Monitors in the HGB Area

displays the statistically summarized maximum, median, and minimum one-hour ozone 

expected number of exceedances averaged across three years computed across all monitors in 

the HGB area. This figure shows the range of expected number of exceedances averaged across 

three consecutive years observed at all regulatory monitors as well as how these distributions 

changed over time. The one-hour ozone expected number of exceedances exhibited a noticeable

downward trend from 1990 until about 1994, and again after 1999. Before 2002, no monitors in 

the HGB area met the one-hour ozone NAAQS; since then, the area has seen a steady increase in 

the number of monitors attaining the standard. By 2013, all monitors in the HGB area were 

below or equal to the one-hour ozone NAAQS expected number of exceedances of 1.0 days per 

year.
Page 9

Figure 2-2: One-Hour Ozone Expected Exceedance Statistics for All Monitors in the 

HGB Area

2.4 Trend Analysis for Ozone Precursors

Decreases in NOX and volatile organic compounds (VOC), precursors to ozone formation,

demonstrate the effectiveness of control measures in reducing emissions; however, due to its 

dependence on meteorological variables, ozone concentrations may not always exhibit trends 

identical to the concentrations of its precursors. This section evaluates trends in concentrations 

of NOX and VOC. Only data that met data completeness checks are used in this section. To meet 

the completeness check, each day must contain at least 18 valid hours of data, each month must 

contain at least 75% of days with data, each quarter must have at least two months of data, and 

each year must contain at least three quarters of data.

NOX are a variable mixture of nitric oxide and nitrogen dioxide and are critical precursors to 

ozone formation. As NOX emissions decrease, ambient concentrations of these compounds 

should also decrease. NOX are primarily created by fossil fuel combustion, lightning, biomass 

burning, and microbial action in soil.

Annual maxima, annual 90th percentile, and annual average daily peak one-hour NOX values

observed in the HGB area are plotted in Figure 2-3: Annual Maxima, 90th Percentile and 

Average of Daily Peak NOx Values (ppb) in the HGB Area, 2000 through 2013. The figure uses 

a logarithmic scale so that all three statistics are visible, and a linear regression line was added 

to each statistic. The linear regression line of the yearly maximum shows a negative slope of 19.9 
Page 10

parts per billion (ppb) per year with a correlation coefficient (r2) of 0.59, and the regression line 

of the yearly 90th percentile shows a negative slope of 3.6 ppb per year with an r2 of 0.76. The 

linear regression line of the yearly average shows a negative slope of 1.8 ppb per year with an r2

of 0.83. All three measures decreased markedly over the period from 2000 through 2013, falling 

25% (maximum), 24% (90th percentile), and 28% (mean). Strong downward trends in ambient 

NOX concentrations are evidence of the effectiveness of the emission controls depicted in the 

emission-trend data.

Figure 2-3: Annual Maxima, 90th Percentile and Average of Daily Peak NOX Values 

(ppb) in the HGB Area, 2000 through 2013

The other major class of ozone precursors is VOC. Since the mid-1990s, the TCEQ has collected 

40-minute measurements, on an hourly basis, of over 40 species of VOC using auto-GC 

instruments. This section focuses on two prevalent compounds, ethylene and propylene, that are 

associated with rapid and efficient ozone formation. Since the majority of VOC production 

occurs along the Houston Ship Channel, the eight auto-GC instruments near the area were 

examined. Yearly geometric means were computed from valid ambient hourly measurements. A 

geometric mean was calculated by taking the natural logarithm of each measurement, averaging 

these logs, and then calculating the antilog of this mean log value. The geometric mean is a 

preferable statistic to median or arithmetic (ordinary) mean for evaluating the central tendency 

of data when the data are skewed, i.e., when the data are not symmetrically, or normally, 

distributed, but instead clustered around extreme high or low values. A geometric mean is more 

robust than an ordinary average, in that its value is not greatly influenced by one or a few very 
Page 11

high or very low values. Many distributions of pollutant measurements, especially VOC, in the 

HGB area are skewed.

The annual geometric mean of ethylene concentrations in parts per billion carbon (ppbC) is 

shown in Figure 2-4: Yearly Geometric Mean Ethylene Concentrations (ppbC) at the Eight 

Houston Ship Channel Monitors, 2000 through 2013. Prior to 2004, only three of the eight 

monitors had enough valid data to calculate annual geometric mean ethylene. Generally, the 

geometric mean ethylene concentrations at all of the auto-GC monitors have decreased. 

Ethylene at the Channelview monitor (C15) steadily decreased until 2013 when the geometric 

mean ethylene increased. Ethylene at the Houston Regional Monitoring Corporation (HRM) 3 

Haden Road non-regulatory, industry-sponsored monitor (C603) began increasing in 2011 and 

2012 but resumed its decreasing trend in 2013.

Figure 2-4: Yearly Geometric Mean Ethylene Concentrations (ppbC) at the Eight 

Houston Ship Channel Monitors, 2000 through 2013

Figure 2-5: Yearly Geometric Mean Propylene Concentrations (ppbC) at the Eight Houston 

Ship Channel Monitors, 2000 through 2013 shows the annual geometric mean for propylene. 

Like ethylene, only three of the eight monitors had enough data to calculate annual geometric 

mean propylene prior to 2004. Note that the y-axis in this figure is the same as in Figure 2-5. 

The geometric means for propylene are lower than the geometric means for ethylene for all the 

years. All monitors showed a steady decrease in geometric mean propylene from 2000 through 

2013. Though decreasing at different rates, these long-term decreases in ambient concentrations 
Page 12

of ethylene and propylene suggest overall industrial emissions of these compounds have 

decreased considerably since 2000.

Figure 2-5: Yearly Geometric Mean Propylene Concentrations (ppbC) at the Eight 

Houston Ship Channel Monitors, 2000 through 2013

2.5 Ozone Data and Trend Analysis Summary

Ozone concentrations decreased dramatically in the HGB area since the 1990s. In 2013, the 

three-year average expected number of exceedances met the one-hour ozone standard of 1.0

days per year. Examination of the trends in one-hour ozone three-year average expected number 

of days where the one-hour ozone exceeded 0.12 ppm reveals substantial downward trends. 

Evaluation of local changes of ozone precursors showed similar significant downward trends. 

These results suggest that the significant ozone reductions achieved in the HGB area are 

primarily due to local emission reductions.

SECTION 3: PERMANENT AND ENFORCEABLE EMISSIONS REDUCTIONS

3.1 Control Measures

The Houston-Galveston-Brazoria (HGB) nonattainment area for the one-hour ozone National 

Ambient Air Quality Standard (NAAQS), which consists of Brazoria, Chambers, Fort Bend, 

Galveston, Harris, Liberty, Montgomery, and Waller Counties, includes one of the most 

comprehensively controlled industrial complexes in the world. The Texas Commission on 
Page 13

Environmental Quality (TCEQ) has developed stringent and innovative regulations that address 

nitrogen oxides (NOX), volatile organic compounds (VOC), and highly reactive volatile organic 

compounds (HRVOC).

3.2 List of Existing Control Measures

Over decades of air quality planning to improve ozone levels in the HGB area, a broad range of 

control measures have been implemented for each emission source category. Table 3-1: Existing 

Ozone Control Measures Applicable to the HGB Eight-County Nonattainment Area lists the 

existing ozone control strategies that have been implemented for the one-hour and 1997 eighthour ozone standards in the HGB area. The measures listed in Table 3-1 are permanent and 

enforceable and are included in the applicable implementation plan in accordance with Federal 

Clean Air Act (FCAA), §107(d)(3)(E)(iii).

Table 3-1: Existing Ozone Control Measures Applicable to the HGB Eight-County 

Nonattainment Area

Measure Description Start Date(s)

NOX Mass Emissions Cap 

and Trade (MECT) Program

30 Texas Administrative 

Code (TAC) Chapter 101, 

Subchapter H, Division 3

Overall 80% NOX reduction from existing industrial 

sources and utility power plants, implemented through 

a cap and trade program

Affects utility boilers, gas turbines, heaters and 

furnaces, stationary internal combustion engines, 

industrial boilers, and many other industrial sources

April 1, 2003 and phased 

in through April 1, 2007

HRVOC Rules and Highly 

Reactive Volatile Organic 

Compounds Emissions Cap 

and Trade (HECT) Program

30 TAC Chapter 101, 

Subchapter H, Division 6

Affects cooling towers, process vents, and flares, and 

establishes an annual emissions limit with a cap and 

trade for each applicable site in Harris County 

Seven perimeter counties subject to permit allowable 

limits and monitoring requirements

Monitoring 

requirements began 

January 31, 2006

Cap and trade program 

implemented January 1, 

2007

HECT cap incrementally 

stepped-down from 

2014 through 2017 for a 

total 25% cap reduction

HRVOC Fugitive Rules

30 TAC Chapter 115, 

Subchapter D, Division 3

More stringent leak detection and repair (LDAR) 

requirements for components in HRVOC service

Additional components included in LDAR program: 

more stringent repair times, lower leak detection, and 

third-party audit requirements

March 31, 2004

VOC Control Measures –

Storage Tanks

30 TAC Chapter 115, 

Subchapter B, Division 1

Requires controls for slotted guide poles and more 

stringent controls for other fittings on floating roof 

tanks, and control requirements or operational 

limitations on landing floating roof tanks

Eliminates exemption for storage tanks for crude oil or 

natural gas condensate, and regulates flash emissions 

from these tanks

January 1, 2009

Compliance with revised 

monitoring and testing 

requirements required 

by March 1, 2013
Page 14

Measure Description Start Date(s)

VOC Control Measures –

Degassing Operations

30 TAC Chapter 115, 

Subchapter F, Division 3

Requires vapors from degassing to be vented to a 

control device for a longer time period, and removes 

exemption from degassing to control for tanks with 

capacity of 75,000 to 1,000,000 gallons

Clarification of rule and monitoring and testing 

requirements, additional control options, and 

notification requirements

January 1, 2009

February 17, 2011

NOX Emission Standards for 

Nitric Acid and Adipic Acid 

Manufacturing

30 TAC Chapter 117, 

Subchapter F

NOX emission standards for nitric acid and adipic acid 

manufacturing facilities in the HGB area

November 15, 1999

Utility Electric Generation in 

East and Central Texas

30 TAC Chapter 117, 

Subchapter E, Division 1

NOX control requirements (approximately 55 %) on 

utility boilers and stationary gas turbines at utility 

electric generation sites in East and Central Texas

May 1, 2003 through 

May 1, 2005

VOC Control Measures

30 TAC Chapter 115

Additional control technology requirements for batch 

processes and bakeries by December 31, 2002

Additional VOC measures adopted earlier for 

reasonably available control technology (RACT) 

purposes: general vent gas control, industrial 

wastewater, loading and unloading operations, general 

VOC LDAR, solvent using process, etc. (see Appendix D: 

Reasonably Available Control Technology Analysis of 

the Houston-Galveston-Brazoria Attainment 

Demonstration State Implementation Plan Revision for 

the 1997 Eight-Hour Ozone Standard adopted March 

10, 2010 (2010 HGB AD SIP Revision) for more details)

December 31, 2002 and 

earlier

VOC Control Measures –

Offset Lithographic Printers

30 TAC Chapter 115, 

Subchapter E, Division 4

Additional control technology requirements for offset 

lithographic printers

Revised in 2010 to limit VOC content of solvents used 

by offset lithographic printing facilities and to include 

smaller sources in rule applicability (see Appendix D of 

the 2010 HGB AD SIP Revision for more details)

December 31, 2002

March 1, 2011 for major 

sources

March 1, 2012 for minor 

sources
Page 15

Measure Description Start Date(s)

VOC Control Measures –

Solvent-Using Processes

30 TAC Chapter 115, 

Subchapter E

Revised in 2011 to implement RACT requirements per 

control technique guidelines published by the United 

States Environmental Protection Agency (EPA)

Seven emission source categories in the HGB area: 

industrial cleaning solvents; flexible package printing; 

paper, film, and foil coatings; large appliance coatings; 

metal furniture coatings; miscellaneous metal and 

plastic parts coatings; and miscellaneous industrial 

adhesives (see Houston-Galveston-Brazoria 

Reasonably Available Control Technology Analysis 

Update State Implementation Plan Revision for the 

1997 Eight-Hour Ozone Standard adopted December 7, 

2011 for more details)

March 1, 2013

Refueling – Stage I

30 TAC Chapter 115, 

Subchapter C, Division 2

Captures gasoline vapors that are released when 

gasoline is delivered to a storage tank

Vapors returned to the tank truck as the storage tank 

is being filled with fuel, rather than released into the 

ambient air

1990

Refueling – Stage II

30 TAC Chapter 115, 

Subchapter C, Division 4

Captures gasoline vapors when a vehicle is being 

fueled at the pump

Vapors returned through the pump hose to the 

petroleum storage tank, rather than released into the 

air

1992

A SIP revision 

authorizing the 

decommissioning of 

Stage II vapor control 

equipment was

submitted to the EPA on 

October 31, 2013. 

Facilities may continue 

operating Stage II until 

August 31, 2018.

Federal Area/Non-Road 

Measures

Series of emissions limits, implemented by the EPA, for 

area and non-road sources

Examples: diesel and gasoline engine standards for 

locomotives and leaf-blowers

Through 2018

Texas Emissions Reduction 

Plan (TERP)

30 TAC Chapter 114, 

Subchapter K

Provides grant funds for on-road and non-road heavyduty diesel engine replacement/retrofitJanuary 2002

California Standards for 

Certain Gasoline Engines

California standards for non-road gasoline engines 25 

horsepower and larger

May 1, 2004

Stationary Diesel Engines

30 TAC Chapter 117, 

Subchapter B, Division 3

Prohibition on operating stationary diesel and dualfuel engines for testing and maintenance purposes 

between 6:00 a.m. and noon

April 1, 2002
Page 16

Measure Description Start Date(s)

Natural Gas-Fired Small 

Boilers, Process Heaters, 

and Water Heaters

30 TAC Chapter 117, 

Subchapter E, Division 3

NOX emission limits on small-scale residential and 

industrial boilers, process heaters, and water heaters 

equal to or less than 2.0 million British thermal units 

per hour

2002

Minor Source NOX Controls 

for Non-MECT Sites

30 TAC Chapter 117, 

Subchapter D, Division 1

NOX emission limits on boilers, process heaters, 

stationary engines, and turbines at minor sites not 

included in the MECT program (uncontrolled design 

capacity to emit less than 10 tons per year)

March 31, 2005

Texas Low Emission Diesel 

(TxLED)

30 TAC Chapter 114, 

Subchapter H, Division 2

Requires all diesels for both on-road and non-road use 

to have a lower aromatic content and a higher cetane 

number

Phase in began October 

31, 2005

TxLED for Marine Fuels

30 TAC Chapter 114, 

Subchapter H, Division 2

Adds marine distillate fuels X and A, commonly known 

as DMX and DMA, or Marine Gas Oil, into the 

definition of diesel fuels, requiring them to be TxLED 

compliant

June 24, 2007

Texas Low Reid Vapor 

Pressure (RVP) Gasoline

30 TAC Chapter 114, 

Subchapter H, Division 1

Requires all gasoline for both on-road and non-road 

use to have a RVP of 7.8 pounds per square inch or less 

from May 1 through October 1 each year

April 2000

Voluntary Mobile Emission 

Reduction Program

Voluntary measures administered by the HoustonGalveston Area Council (H-GAC) (see Appendix F: 

Evaluation of Mobile Source Control Strategies for the 

Houston-Galveston-Brazoria State Implementation 

Plan (With Detailed Strategies), prepared for H-GAC by 

ENVIRON International Corporation, of the 2010 HGB 

AD SIP Revision)

Through 2018

Federal On-Road Measures Series of emissions limits, implemented by the EPA, for 

on-road vehicles

Examples: Tier 1 and Tier 2 vehicle standards, low 

sulfur diesel standards, National Low Emission Vehicle 

standards, and reformulated gasoline

Phase in through 2013

Vehicle Inspection/ 

Maintenance

30 TAC Chapter 114, 

Subchapter C

Yearly treadmill-type testing for pre-1996 vehicles and 

computer checks for 1996 and newer vehicles

May 1, 2002 in Harris 

County

May 1, 2003 in Brazoria, 

Fort Bend, Galveston, 

and Montgomery 

Counties

Speed Limit Reduction

43 TAC Chapter 25, 

Subchapter B

Five miles per hour (mph) below what was posted 

before May 1, 2002, on roadways where speeds were 

65 mph or higher

September 2003
Page 17

Measure Description Start Date(s)

Transportation Control 

Measures

Various measures in H-GAC’s long-range 

transportation plans (see Appendix F of the 2010 HGB 

AD SIP Revision for more details)

Phase in through 2018

Voluntary Energy 

Efficiency/Renewable 

Energy

Energy efficiency and renewable energy projects 

encouraged by Senate Bill (SB) 7, 76th Texas 

Legislature, 1999 and SB 5, 77th Texas Legislature, 

2001

September 1, 1999 and 

September 1, 2001 

Automotive Windshield 

Washer Fluid

30 TAC Chapter 115, 

Subchapter G, Division 1

VOC content limitation on automotive windshield 

washer fluid sold, supplied, distributed, or 

manufactured for use in Texas

January 1, 1995

The following control measures being implemented in the HGB area are permanent and 

enforceable, but the emissions reductions from these control measures were not included in 

previous HGB attainment demonstration SIP revisions.

3.2.1 Control of Volatile Organic Compounds Emissions from Storage Tanks

In May 2007, the commission adopted revisions to the rules in 30 TAC Chapter 115, Subchapter 

B, Division 1 for VOC storage tanks located in the HGB ozone nonattainment area. The revised 

requirements reduce uncontrolled VOC flash emissions at oil and gas exploration and 

production sites and other VOC emissions from storage tanks. These amendments to Chapter 

115 are described in more detail in the preamble of the adopted rule (32 TexReg 3178) 

(http://www.tceq.texas.gov/assets/public/implementation/air/rules/texas-register/32-texreg3178.pdf).

Although these rules resulted in actual reductions in flash emissions, no credit was claimed in 

the 2010 HGB AD SIP Revision. At the time the rules were adopted, it was unknown how many 

affected sites would be required to install controls. In 2010, ENVIRON International 

Corporation (ENVIRON) Project 06-17477T quantified the VOC emission reductions resulting 

from the implementation of these Chapter 115 requirements to control VOC flash emissions 

from crude oil and condensate storage tanks in the HGB ozone nonattainment area. Based upon 

area source emissions inventory development methods at the time of publication, ENVIRON 

Project 06-17477T estimated that the Chapter 115 rules would result in 10,683 tons of VOC 

reductions per year (29.3 tons of VOC reductions per day) in the HGB area. More information 

on ENVIRON Project 06-17477T can be found on the TCEQ website 

(http://www.tceq.texas.gov/assets/public/implementation/air/am/contracts/reports/ei/58207

84005FY1022-20100831-environ-flash_emission.pdf).

3.2.2 Mass Emissions Cap and Trade Program

The MECT program uses an annual cap to limit the amount of NOX emissions from all 

applicable sources in the HGB area. The MECT program allocated NOX allowances to applicable 

facilities in the HGB area based on actual levels of activity from the years 1997 through 1999. 

These allowances are referred to as actual allowances. The program also allocated allowances to 

certain applicable facilities based on their permit limit. These allowances are referred to as 

allowable allowances and were allocated to facilities that had not yet been built or had not been 

operational long enough to establish baseline data. Applicable facilities that do not meet the 

criteria for receiving an allocation of actual or allowable allowances must acquire allowances 

from facilities in the program that receive an allocation of actual allowances. Additionally, 
Page 18

facilities that were allocated allowable allowances are required to revise their allocation to be 

based on actual operating data after an operational baseline period has been established. 

Participation in the MECT program is mandatory for all applicable sources. 

The photochemical modeling for the 2010 HGB AD SIP Revision included 120.0 tons per day 

(tpd) of NOX emissions in 2018 based on the October 2009 MECT cap. The modeled MECT cap 

is a function of the actual allowance allocations, allowable allowance allocations, and the 

conversion of emission reduction credits to allowance allocations. The projected 2018 MECT 

cap, as of March 2014 is 109.9 tpd of NOX emissions, which is a reduction of 10.1 tpd of NOX

emissions from the modeled MECT cap. This reduction can be attributed to facilities revising 

allowance allocations based on permit limits to allocations based on actual operating data since 

typically most facilities operate below their permit limits. Further MECT cap reductions are 

expected in the future due to sources that have yet to convert their allowable allowances into 

actual allowances and companies that choose to permanently retire allowances to comply with 

the requirements of other air quality programs.

3.2.3 Tier 3 Motor Vehicle Emission and Fuel Standards

On April 28, 2014, the EPA published the final rule for the new Tier 3 Motor Vehicle Emission 

and Fuel Standards (79 FR 23414). Tier 3 emission standards will apply to new, light-duty motor 

vehicles, light-duty trucks, and medium-duty passenger vehicles beginning model year 2017 and 

will be fully phased in by model year 2025. Tier 3 emission standards will also apply to chassiscertified Class 2b and Class 3 heavy-duty vehicles beginning model year 2018 and will be fully 

phased in by model year 2022. The Tier 3 emission standards also extend the regulatory useful 

life period during which the standards apply from 120,000 miles to 150,000 miles.

When fully implemented, the Tier 3 exhaust emission standards for light-duty vehicles will 

provide approximately an 80% reduction in non-methane organic gases (NMOG) and NOX

(NMOG+NOX) standards and a 70% reduction in per-vehicle particulate matter (PM) standards 

when compared to the current fleet average. The Tier 3 exhaust standards for heavy-duty 

vehicles provide about a 60% reduction in both fleet average NMOG+NOX standards and pervehicle PM standards when compared to the current standards.

Tier 3 fuel standards will limit gasoline sulfur to no more than 10 parts per million (ppm) of 

sulfur on an annual average basis beginning January 1, 2017, a reduction of approximately 66% 

when compared to the current standard. The current gasoline sulfur standards specifying an 80 

ppm refinery gate cap and 95 ppm downstream cap are maintained under the new Tier 3 fuel 

standards. Removing sulfur from gasoline allows a vehicle’s catalyst to work more efficiently. 

The Tier 3 gasoline sulfur standard will make emission control systems more effective for both 

existing and new vehicles, and will enable automobile manufacturers to meet the more stringent 

Tier 3 vehicle emissions standards.

3.2.4 New International Marine Diesel Engine and Marine Fuel Standards for Oceangoing 

Vessels and Emissions Control Areas

In March 2009, the United States (U.S.) government submitted a request to the International 

Maritime Organization (IMO) for the creation of an emissions control area (ECA) around the 

nation's coastlines. The request was granted and the North American ECA was officially 

designated by the IMO on March 26, 2010 and became enforceable in August 2012. All marine 

diesel fuels used by oceangoing vessels (OGV) in the North American ECA will be limited to a 

maximum sulfur content of 1,000 ppm beginning January 1, 2015, and all new engines on OGV 

operating in these areas must use emission controls that achieve an 80% reduction in NOX 

emissions beginning January 1, 2016.
Page 19

The EPA regulations for marine diesel fuel and new marine engines less than 30 liters per 

cylinder displacement and the new International Convention for the Prevention of Pollution 

from Ships (MARPOL) Annex VI standards for marine residual fuels and new marine diesel 

engines above 30 liters per cylinder displacement will apply to all OGV flagged and registered in 

the U.S. The EPA's regulations for new Category 3 marine engines and new sulfur limits for 

marine diesel fuel will also apply to all OGV flagged and registered in the U.S. In addition, the 

new MARPOL Annex VI standards will apply to all new marine diesel engines and fuels on 

foreign marine vessels that operate near U.S. coasts and ports.

The new marine diesel engine and fuel standards will provide a 96% reduction in sulfur in 

marine diesel fuels, as well as an 85% reduction in PM emissions and an 80% reduction in NOX

emissions, when compared to current standards4

.

Cumulatively, these new marine diesel engine and fuel standards are estimated by the EPA to 

result in a 0.5 to 1.0 parts per billion (ppb) reduction of ozone in the ambient air of the HGB 

ozone nonattainment area by 20205

.

3.3 Additional Measures

Additional air quality improvement measures being implemented in the HGB area are described 

in this section. These additional measures are beneficial toward reducing ozone and assure that 

the HGB area will continue to maintain the one-hour ozone standard.

3.3.1 SmartWay Transport Partnership and the Blue Skyways Collaborative

Among its various efforts to improve air quality in Texas, the TCEQ continues to promote two 

voluntary programs in cooperation with the EPA: SmartWay Transport Partnership and Blue 

Skyways Collaborative.

The SmartWay Transport Partnership is a market-driven partnership aimed at helping 

businesses move goods in the cleanest most efficient way possible. This program is a voluntary 

EPA program primarily for the freight transport industry that promotes strategies and 

technologies to help improve fleet efficiency while also reducing air emissions.

There are over 3,000 SmartWay partners in the U.S., including most of the nation’s largest truck 

carriers, all the Class 1 rail companies, and many of the top Fortune 500 companies. Since its 

founding, SmartWay has reduced oil consumption by 120.7 million barrels and prevented the 

release of 738,000 tons of NOX and 37,000 tons of PM into the atmosphere6

. Ports in the U.S. 

rely on SmartWay’s Port Drayage Truck program to help reduce pollution in and around major 

national ports. The Port of Houston Authority’s (PHA) partnership with the Environmental 

Defense Fund and H-GAC in the Port Drayage Truck Bridge Loan Program received $9 million 

from the EPA’s Diesel Emission Reduction Act SmartWay Program in 2009. On average, four

trucks a month, or about 50 trucks a year, were approved for replacement funding. Several 

workshops have been sponsored by the PHA for trucking companies and independent 

owner/operators to learn about funding opportunities.

 4 EPA, 2009. Oceangoing Vessels, Emission Control Area Designation, 

http://www.epa.gov/otaq/oceanvessels.htm#emissioncontrol, Office of Transportation and Air Quality. 5 EPA, 2009. Regulatory Announcement: Proposal of Emission Control Area Designation for Geographic 

Control of Emissions from Ships, EPA-420-F-09-015, Figure 4: Potential Benefits of U.S. ECA Ozone 

Reductions in 2020, March 2009.

6 EPA, 2014. SmartWay Program Highlights 2014, EPA-420-F-14-003, February 2014.
Page 20

Approximately 160 Texas companies are SmartWay partners. The SmartWay Transport 

Partnership will continue to benefit the HGB area by reducing emissions as more companies and 

affiliates join, and additional idle reduction, trailer aerodynamic kits, low rolling resistance tire, 

and retrofit technologies are incorporated into SmartWay-verified technologies.

The Blue Skyways Collaborative was created to encourage voluntary air emission reductions by 

planning or implementing projects that use innovations in diesel engines, alternative fuels, and 

renewable energy technologies applicable to on-road and non-road sources. The Blue Skyways 

Collaborative partnerships include international, federal, state, and local governments, nonprofit organizations, environmental groups, and private industries.

3.3.2 American Waterways Operators Tank Barge Emissions Best Management Practices

Using infrared gas imaging technology in field studies conducted in the summer of 2005, the 

TCEQ detected inadvertent VOC emissions from tank barges operating in the HGB area. The 

Louisiana Department of Environmental Quality (LDEQ) also detected inadvertent emissions 

from tank barges in similar field studies conducted in the same time period. In response to these 

field studies, the American Waterways Operators (AWO) voluntarily developed industry Best 

Management Practices (BMP) to reduce VOC emissions from tank barges. The BMP includes 

procedures to reduce VOC emissions from equipment and operations on tank barges. The 

recommendations are a combination of inspection, corrective action, preventative maintenance, 

and operational, procedural, and training practices.

The BMP was reviewed by the Chemical Transportation Advisory Committee (CTAC), United 

States Coast Guard (USCG), LDEQ, and TCEQ. The BMP was distributed to AWO members in 

2006 for implementation on a voluntary basis. While the BMP is a voluntary measure and does 

not impose an enforceable commitment on AWO members, the implementation of the BMP, 

where applicable, may contribute to reducing inadvertent VOC emissions from barges during 

dock operations and during transit, which will help improve the air quality in the HGB area. A 

copy of the 2006 BMP document is provided in Appendix J: Recommendations for Best 

Management Practices to Control and Reduce Inadvertent Cargo Vapor Emissions in the Tank 

Barge Community of the 2010 HGB AD SIP Revision.

3.3.3 Consent Decrees with Refineries

The EPA's National Petroleum Refinery Initiative7 has resulted in multi-issue settlement 

agreements with the nation's major petroleum refineries. As of March 2014, 109 refineries 

representing more than 90% of total domestic refining capacity are under settlement, and 

negotiations are underway with other refiners not currently under settlement. The EPA consent 

decrees limit emissions from fluidized catalytic cracking units, sulfur recovery units, heaters and 

boilers, and flares. The EPA estimates that full implementation of the current settlements will 

result in more than 93,000 tons per year of NOX emission reductions. The EPA also anticipates 

VOC emission reductions will result from consent decree requirements that reduce hydrocarbon 

flaring including:

• installing continuous emissions monitoring systems (CEMS) or predictive emissions 

monitoring systems;

• operating a flare gas recovery system to control continuous or routine flaring;

• limiting flaring to only process upset gases, fuel gas released as a result of relief valve 

leakage, or gas released due to a malfunction; and

 7 http://www2.epa.gov/enforcement/petroleum-refinery-national-case-results
Page 21

• eliminating the routes of generated fuel gases and monitoring the flare with CEMS or a flow 

meter.

Although some of the estimated NOX and VOC emission reductions may have occurred prior to 

2006, full implementation of the settlements is not expected until the end of 2015. Since 

approximately 14% of the nation’s petrochemical refining capacity is located in the HGB area8

, 

the commission expects the HGB area will benefit from the NOX and VOC emission reductions

required by these settlements.

3.3.4 Standards of Performance for Stationary Compression Ignition Internal Combustion 

Engines

The TCEQ previously adopted NOX emission standards for stationary diesel reciprocating 

internal combustion engines in 30 TAC Chapter 117 for the HGB area. The NOX emission 

standards for stationary diesel engines in §117.310 and §117.2010 are used in conjunction with 

the MECT program for sources subject to MECT. For sources subject to §117.2010 that are not in 

MECT, the NOX emission standards apply on a unit-by-unit basis. Additionally, the TCEQ 

adopted requirements in the exemption criteria for stationary diesel reciprocating internal 

combustion engines in §117.303 and §117.2003 that require engines installed, modified, 

reconstructed, or relocated on or after October 1, 2001 to meet the corresponding emission 

standards for non-road engines in 40 Code of Federal Regulations (CFR) Part 89, §89.112(a), 

Table 1 to be in effect at the time of the installation, modification, reconstruction, or relocation 

of the engine. The combination of the emission standards, the MECT program, and the 

provisions to meet EPA’s Tier standards (Tiers 1, 2, and 3) in 40 CFR Part 89 to qualify for 

exemption makes the Chapter 117 requirements for stationary diesel reciprocating internal 

combustion engines equivalent to, or more stringent than, most of the requirements in EPA’s 

New Source Performance Standards in 40 CFR Part 60, Subpart IIII, Standards of Performance 

for Stationary Compression Ignition Internal Combustion Engines. However, the NOX emission 

standards in 40 CFR §60.4204(c)(3) for large-cylinder non-emergency stationary compression 

ignition internal combustion engines (i.e., diesel-fired engines) installed on or after January 1, 

2016 are more stringent than the lowest NOX emission standards for stationary diesel 

reciprocating internal combustion engines in §117.310 and §117.2010 and 40 CFR Part 

§89.112(a), Table 1. The exact amount of NOX reductions resulting from 40 CFR §60.4204(c)(3) 

will be dependent on the turnover of existing engines and new installations after 2015 and 

cannot be estimated at this time. However, the requirements for new non-emergency stationary 

diesel-fired engines in the large-cylinder category starting in 2016 should ultimately result in 

additional NOX reductions beyond that already relied upon in the 2010 HGB AD SIP Revision.

3.3.5 Energy Efficiency and Renewable Energy Measures

Energy efficiency (EE) measures are typically programs that reduce the amount of electricity 

and natural gas consumed by residential, commercial, industrial, and municipal energy 

consumers. Examples of energy efficiency measures include increasing insulation in homes, 

installing compact fluorescent light bulbs, and replacing motors and pumps with high efficiency 

units. Renewable energy (RE) measures include programs that generate energy from resources 

that are replenished or are otherwise not consumed as with traditional fuel-based energy 

production. Examples of renewable energy include wind energy and solar energy projects.

 8 U.S. Energy Information Administration. Refinery Capacity Report. June 21, 2013. 

http://www.eia.gov/petroleum/refinerycapacity/
Page 22

Emission reductions resulting from these programs were not explicitly included in the 

photochemical modeling for the 2010 HGB AD SIP Revision because local efficiency efforts may 

not result in local emissions reductions or may be offset by increased demand in electricity. The 

complex nature of the electrical grid makes accurately quantifying emission reductions from 

EE/RE measures difficult. At any given time, it is impossible to determine exactly where a 

specific user’s electricity was produced. The electricity for a user in the HGB area could be 

generated by a power plant in West Texas, in a nearby attainment county, or within the 

nonattainment area. If electrical demand is reduced in the HGB area due to these local efficiency 

measures, then emission reductions from power generation facilities may occur in any number 

of locations around the state.

The Texas Legislature has enacted a number of EE/RE measures and programs. The following is 

a summary of Texas EE/RE legislation since 1999.

• 76th Texas Legislature, 1999

• SB 7 

• House Bill (HB) 2492 

• HB 2960 

• 77th Texas Legislature, 2001

• SB 5 

• HB 2277 

• HB 2278 

• HB 2845 

• 78th Texas Legislature, 2003

• HB1365 (Regular Session)

• 79th Texas Legislature, 2005

• SB 20 (First Called Session)

• HB 2129 (Regular Session)

• HB 2481 (Regular Session)

• 80th Texas Legislature, 2007

• HB 66 

• HB 3070 

• HB 3693 

• SB 12 

• 82nd Texas Legislature, 2011

• SB 898 (Regular Session)

• SB 924 (Regular Session)

• SB 981 (Regular Session)

• SB 1125 (Regular Session)

• SB 1150 (Regular Session)

• HB 51 (Regular Session)

3.3.5.1 Renewable Energy

SB 5, 77th Texas Legislature, 2001, set goals for political subdivisions in affected counties to 

implement measures to reduce energy consumption from existing facilities by 5% each year for 

five years from January 1, 2002 through January 1, 2006. In 2007, the 80th Texas Legislature 

passed SB 12, which extended the timeline set in SB 5 through 2007 and made the annual 5%

reduction a goal instead of a requirement. The State Energy Conservation Office (SECO) is 

charged with tracking the implementation of SB 5 and SB 12. Also during the 77th Texas 
Page 23

Legislature, the Energy Systems Laboratory (ESL), part of the Texas Engineering Experiment 

Station, Texas A&M University System, was mandated to provide an annual report on EE/RE 

efforts in the state as part of TERP under Texas Health and Safety Code (THSC), §388.003(e).

The 79th Texas Legislature, 2005, Regular and First Called Sessions, amended SB 5 through SB 

20, HB 2129, and HB 2481 to add, among other initiatives, renewable energy initiatives that

require: 5,880 megawatts of generating capacity from renewable energy by 2015; the TCEQ to 

develop a methodology for calculating emission reductions from renewable energy initiatives 

and associated credits; the ESL to assist the TCEQ in quantifying emissions reductions from 

EE/RE programs; and the Public Utility Commission of Texas (PUCT) to establish a target of 

10,000 megawatts of installed renewable technologies by 2025.

HB 2129, 79th Texas Legislature, 2005, Regular Session, directed the ESL to collaborate with 

the TCEQ to develop a methodology for computing emission reductions attributable to use of 

renewable energy and for the ESL to annually quantify such emission reductions. HB 2129 

directed the Texas Environmental Research Consortium to use the Texas Engineering 

Experiment Station to develop this methodology. With the TCEQ’s guidance, the ESL produces 

an annual report, Statewide Air Emissions Calculations from Energy Efficiency, Wind and 

Renewables, detailing these efforts.

In addition to the programs discussed and analyzed in the ESL report, local governments may 

have enacted measures beyond what has been reported to SECO and the PUCT. The TCEQ 

encourages local political subdivisions to promote EE/RE measures in their respective 

communities and to ensure these measures are fully reported to SECO and the PUCT.

SB 981, 82nd Texas Legislature, 2011, Regular Session, allows a retail electric customer to 

contract with a third party to finance, install, or maintain a distributed renewable generation 

system on the customer's side of the electric meter, regardless of whether the customer owns the 

installed system. SB 981 also prohibits the PUCT from requiring registration of the system as an 

electric utility if the system is not projected to send power to the grid.

3.3.5.2 Residential and Commercial Building Codes and Programs

THSC, Chapter 388, Texas Building Energy Performance Standards, as adopted in SB 5 of the 

77th Texas Legislature, 2001, states in §388.003(a) that single-family residential construction 

must meet the energy efficiency performance standards established in the energy efficiency 

chapter of the International Residential Code. The Furnace Pilot Light Program includes energy 

savings accomplished by retrofitting existing furnaces. Also included is a January 2006 federal 

mandate raising the minimum Seasonal Energy Efficiency Ratio (SEER) for air conditioners in 

single-family and multi-family buildings from 10 to 13.

THSC, Chapter 388, as adopted in SB 5 of the 77th Texas Legislature, 2001, states in 

§388.003(b) that non-single-family residential, commercial, and industrial construction must 

meet the energy efficiency performance standards established in the energy efficiency chapter of 

the International Energy Conservation Code.

3.3.5.3 Federal Facility Energy Efficiency and Renewable Energy Projects

Federal facilities are required to reduce energy use by Presidential Executive Order 13123 and 

the Energy Policy Act of 2005 (Public Law 109-58 EPACT20065). The ESL compiled energy 

reductions data for the federal EE/RE projects in Texas.
Page 24

3.3.5.4 Political Subdivisions Projects

SECO funds loans for energy efficiency projects for state agencies, institutions of higher 

education, school districts, county hospitals, and local governments. Political subdivisions in 

nonattainment and affected counties are required by SB 5, 77th Texas Legislature, 2001, to 

report EE/RE projects to SECO. These projects are typically building systems retrofits, nonbuilding lighting projects, and other mechanical and electrical systems retrofits such as 

municipal water and waste water treatment systems.

3.3.5.5 Electric Utility Sponsored Programs

Utilities are required by SB 7, 76th Texas Legislature, 1999, and SB 5, 77th Texas Legislature, 

2001, to report demand-reducing energy efficiency projects to the PUCT (see THSC, §386.205 

and Texas Utilities Code (TUC), §39.905). These projects are typically air conditioner 

replacements, ventilation duct tightening, and commercial and industrial equipment 

replacement.

SB 1125, 82nd Texas Legislature, 2011, Regular Session, amended the TUC, §39.905 to require 

energy efficiency goals to be at least 30% of annual growth beginning in 2013. The metric for the 

energy efficiency goal remains at 0.4% of peak summer demand when a utility program accrues 

that amount of energy efficiency. SB 1150, 82nd Texas Legislature, 2011, Regular Session, 

extended the energy efficiency goal requirements to utilities outside the Electric Reliability 

Council of Texas area.

3.3.5.6 Energy Efficiency Programs

HB 3693, 80th Texas Legislature, 2007, amended the Texas Education Code, Texas Government 

Code, THSC, and TUC. The bill:

• requires state agencies, universities, and local governments to adopt energy efficiency 

programs;

• provides additional incentives for electric utilities to expand energy conservation and 

efficiency programs;

• includes municipal-owned utilities and cooperatives in efficiency programs;

• increases incentives and provides consumer education to improve efficiency programs; and

• supports other programs such as revision of building codes and research into alternative 

technology and renewable energy.

HB 51, 82nd Texas Legislature, 2011, Regular Session, requires new state buildings and major 

renovations to be constructed to achieve certification under an approved high-performance 

design evaluation system.

HB 51 also requires, if practical, that certain new and renovated state-funded university 

buildings comply with approved high-performance building standards.

SB 898, 82nd Texas Legislature, 2011, Regular Session, extended the existing requirement for 

state agencies, state-funded universities, local governments, and school districts to adopt energy 

efficiency programs with a goal of reducing energy consumption by at least 5% per state fiscal 

year (FY) for 10 state FYs from September 1, 2011 through August 31, 2021.

SB 924, 82nd Texas Legislature, 2011, Regular Session, requires all municipally-owned utilities 

and electric cooperatives that had retail sales of more than 500,000 megawatt hours in 2005 to

report each year to SECO information regarding the combined effects of the energy efficiency 
Page 25

activities of the utility from the previous calendar year, including the utility's annual goals, 

programs enacted to achieve those goals, and any achieved energy demand or savings goals.

3.3.6 Clean Air Interstate Rule and Cross-State Air Pollution Rule

In March 2005, the EPA issued the Clean Air Interstate Rule (CAIR) to address electric 

generating utility (EGU) emissions that transport from one state to another. The rule 

incorporates the use of three cap and trade programs to reduce sulfur dioxide (SO2) and NOX: 

the ozone-season NOX trading program, the annual NOX trading program, and the annual SO2

trading program.

Texas was not included in the ozone season NOX program but was included for the annual NOX

and SO2 programs. As such, Texas must make necessary reductions in annual SO2 and NOX

emissions from new and existing EGUs to demonstrate that emissions from Texas do not 

contribute to nonattainment or interfere with maintenance of the 1997 particulate matter with 

an aerodynamic diameter less than or equal to a nominal 2.5 micrometers (PM2.5) NAAQS in 

another state. CAIR consists of two phases for implementing necessary NOX and SO2 reductions. 

Phase I addresses required reductions from 2009 through 2014. Phase II addresses reductions 

in 2015 and thereafter.

In July 2006, the commission adopted a SIP revision to address how the state would meet 

emissions allowance allocation budgets for NOX and SO2 established by the EPA to meet the 

federal obligations under CAIR. The commission adopted a second CAIR-related SIP revision in 

February 2010. This revision incorporated various federal rule revisions that the EPA had 

promulgated since the TCEQ’s initial submittal. It also incorporated revisions to 30 TAC 

Chapter 101 resulting from legislation during the 80th Texas Legislature, 2007.

A December 2008 court decision found flaws in CAIR but kept CAIR requirements in place 

temporarily while directing the EPA to issue a replacement rule. In July 2011, the EPA finalized 

the Cross-State Air Pollution Rule (CSAPR) to meet FCAA requirements and respond to the 

court’s order to issue a replacement program. Texas was included in CSAPR for ozone season 

NOX, annual NOX, and annual SO2 due to the EPA’s determination that Texas significantly 

contributes to nonattainment or interferes with maintenance of the 1997 eight-hour ozone 

NAAQS and the 1997 and 2006 PM2.5 NAAQS in other states. As a result of numerous EGU 

emission reduction strategies already in place in Texas, the annual and ozone season NOX

reduction requirements from CSAPR were relatively small but still significant. The CSAPR 

required an approximate 7% reduction in annual NOX emissions and less than 5% reduction in 

ozone season NOX emissions.

On August 21, 2012, the U.S. Court of Appeals for the District of Columbia (D.C.) Circuit vacated 

the CSAPR. Under the D.C. Circuit Court’s ruling, CAIR will remain in place until the EPA 

develops a valid replacement. On October 5, 2012, the EPA filed a petition seeking an en banc

rehearing of the U.S. Court of Appeals’ decision regarding CSAPR, but the appeal was denied. 

The EPA and various environmental groups petitioned the Supreme Court of the United States 

to review the D.C. Circuit Court's decision on CSAPR. On June 24, 2013, the Supreme Court 

granted the petitions and heard oral arguments in the case on December 10, 2013. On April 29, 

2014, a decision by the Supreme Court reversed the D.C. Circuit and remanded the case. The 

case is currently back before the D.C. Circuit, which has not yet issued instructions for actions. 

At this time, CAIR remains in place. In the meantime, the EPA is seeking input from states on 

the next steps to address interstate transport for current and future NAAQS.
Page 26

3.3.7 Clean School Bus Program

HB 3469, 79th Texas Legislature, 2005, established the Clean School Bus Program, which 

provides monetary incentives for school districts in the state for reducing emissions of diesel 

exhaust from school buses. As of July 2014, the TCEQ Clean School Bus Program has 

reimbursed approximately $25.9 million in grants for over 7,100 school buses across the state, 

with $5.2 million being used for 2,468 school buses in the HGB area.

3.3.8 Texas Emission Reduction Plan

The TERP was created in 2001 by the 77th Texas Legislature to provide grants to offset the 

incremental costs associated with reducing NOX emissions from high-emitting heavy-duty 

internal combustion engines on heavy-duty vehicles, non-road equipment, marine vessels, 

locomotives, and some stationary equipment.

The majority of emissions reduction incentives have been awarded under the Diesel Emissions 

Reduction Incentive Program (DERI). The DERI incentives are awarded to projects to replace, 

repower, or retrofit eligible vehicles and equipment to achieve NOX emission reductions in Texas 

ozone nonattainment areas and other counties identified as affected counties under the TERP 

where ground-level ozone is a concern. The last DERI grants were awarded through August 31, 

2013, with the next grant rounds anticipated after September 1, 2014. From 2001 through 

August 2013, $943 million in DERI grants were awarded for projects estimated to help reduce 

176,364 tons of NOX. Over $405 million in DERI grants were awarded to projects in the HGB 

area, with a projected 80,765 tons of NOX reduced. These projects are estimated to reduce up to 

27.7 tpd of NOX in the HGB areas during 2014. Of the $405 million, $11 million were awarded to 

H-GAC through third-party grants to administer subgrants in the HGB area. H-GAC has used 

this funding to target the replacement of drayage trucks operating in and from the Port of 

Houston with newer models with lower emission ratings.

Three other incentive programs under the TERP will result in the reduction in NOX emissions in 

the HGB area. The Texas Clean Fleet Program (TCFP) was established in 2009 to provide grants 

for the replacement of light-duty and heavy-duty diesel vehicles with vehicles powered by 

alternative fuels, including: natural gas, liquefied petroleum gas, hydrogen, methanol (85% or 

more by volume), or electricity. This program is for larger fleets, with a requirement that an 

applicant apply for replacement of at least 20 vehicles at a time. The last TCFP grants were 

awarded by August 31, 2013, with the next grant round anticipated in May 2014. From 2009 

through August 2013, over $23.6 million in TCFP grants were awarded for projects to reduce an 

estimated 314.5 tons of NOX. Almost $6.8 million in TCFP grants were awarded to projects in 

the HGB area, with a projected 61.9 tons of NOX reduced. These projects are estimated to reduce 

up to 0.05 tpd of NOX in the HGB area during 2014.

The Texas Natural Gas Vehicle Grant Program (TNGVGP) was established in 2011 to provide 

grants for the replacement of medium-duty and heavy-duty diesel vehicles with vehicles 

powered by natural gas. This program may include grants for individual vehicles or multiple 

vehicles. The majority of the vehicle operation must occur in the Texas nonattainment areas, 

other counties designated as affected counties under the TERP, and the counties in and between 

the triangular area between Houston, San Antonio, Dallas, and Fort Worth. The last TNGVGP 

grants were awarded by August 31, 2013, with a new grant round currently open and contracts 

pending. From 2011 through August 2013, almost $26 million in TNGVGP grants were awarded 

for projects to help reduce a projected 816 tons of NOX. Over $9.5 million in TNGVGP grants 

were awarded to projects where the applicant indicated the primary operation of the vehicle 

would occur in and around the HGB area, with a projected 266 tons of NOX reduced. These 

projects are expected to begin reducing 0.29 tpd of NOX in the HGB area starting in 2015.
Page 27

A new Drayage Truck Incentive Program (DTIP) was established in 2013 to provide grants for 

the replacement of drayage trucks operating in and from seaports and rail yards located in 

nonattainment areas. The first grant application period for this program is anticipated to open 

after September 1, 2014.

The TERP is currently authorized through 2019, which will result in continued reductions in the 

significant emissions source categories of heavy-duty on-road and non-road engines. TERP 

projects require reporting and documentation of emissions reductions over a five- to seven-year 

activity life or, in some cases, an even longer period. Projects funded in a particular year will 

continue to report emissions reductions achieved over the activity-life commitment period for 

each project.

3.3.9 83rd Texas Legislature

Summaries of the bills passed during the 83rd Texas Legislature, 2013, Regular Session, that 

have the potential to impact the HGB area are discussed in this section. For legislative updates 

regarding EE/RE measures and programs, see Section 3.3.9: Energy Efficiency and Renewable 

Energy Measures.

Senate Bill 1727

SB 1727 revised some of the criteria for the existing TERP incentive programs and established 

several new programs. The bill also revised the funding allocation formula for the various TERP 

programs.

The existing TERP programs that were revised include: the DERI, the TCFP, and the TNGVGP. 

A new program, the DTIP, was also established.

SB 1727 removed the maximum limits on the cost-effectiveness of a project funded under the 

DERI and authorized the TCEQ to fund projects to convert on-road and non-road diesel engines 

to a dual-fuel configuration using diesel and natural gas. Changes were also made to the TCFP to 

simplify the requirements on the percentage of costs that may be covered by a grant, and to 

authorize the TCEQ to allow trucks used to transport raw agricultural products that are replaced 

under this program to operate a lesser percentage of annual mileage in designated counties than 

is required for other TCFP projects.

The TNGVGP was affected by changes to the Clean Transportation Triangle (CTT) program, 

which provides grants for infrastructure to provide natural gas fueling in designated areas. SB 

1727 expanded the eligible areas under the CTT. The original areas included nonattainment 

areas and counties along the interstate highways connecting the cities of Houston, Dallas, Fort 

Worth, and San Antonio. The expanded areas include other counties designated as affected 

counties under the TERP and the counties located within the triangle formed by the previously 

designated interstate highways. The TNGVGP provides grants for replacement of heavy-duty 

and medium-duty vehicles that travel 75% of the annual mileage in the CTT designated areas. 

Thus, the expansion of the CTT areas also expands the eligible areas of travel under the 

TNGVGP. The bill also authorized the TCEQ to allow trucks used to transport raw agricultural 

products that are replaced under this program to operate a lesser percentage of annual mileage 

in designated counties than is required for other TNGVGP projects.

SB 1727 also established the new DTIP to provide grants for replacement of drayage trucks 

operating at seaports and rail yards located in a nonattainment area. The replacement trucks 

must continue to operate at designated seaports and rail yards and must also operate at least 
Page 28

50% of annual mileage within a maximum distance from the seaports and rail yards as defined 

by the TCEQ.

Other TERP programs not specifically included as weight of evidence strategies, but which are 

expected to have beneficial impacts on reducing emissions in nonattainment areas and other 

areas, were also revised. The maximum grant amounts for the CTT program and the Alternative 

Fueling Facilities Program (AFFP), which provides grants for infrastructure to provide fueling 

for a range of alternative fuels, were increased to a maximum of $600,000. The TERP LightDuty Purchase or Lease Incentive (LDPLI) program, which was established under the original 

TERP legislation in 2001 but never implemented, was also revised and restarted. Under the new 

program criteria, the TCEQ will provide grants of up to $2,500 for the purchase or lease of 

vehicles under 10,000 pounds gross vehicle weight rating that are powered by natural gas, 

liquefied petroleum gas, or electricity (including plug-in hybrid vehicles). The LDPLI program 

will be available statewide.

To implement SB 1727, the commission adopted revisions to 30 TAC §§114.622, 114.629, 

114.650, 114.653, and 114.656 and new 30 TAC §§114.680 - 114.682 on April 9, 2014. The 

commission adopted revisions to 30 TAC §§114.610 - 114.612 and 114.616 and the repeal of 30 

TAC §114.619 on April 30, 2014.

House Bill 2859

HB 2859 increased the funding allocated to the TCEQ’s Local Initiatives Projects (LIP) Program, 

which is available to counties that participate in the Low-Income Vehicle Repair Assistance, 

Retrofit, and Accelerated Vehicle Retirement Program (LIRAP), from $5 million to $7 million 

per year. The funding for LIRAP is from fees collected by the state’s I/M program. In addition, 

the bill limits $2 million of the funding to projects for coordinating with local law enforcement 

officials to reduce the use of counterfeit state inspection stickers. This bill became effective 

September 1, 2013.

3.3.10 Local Initiative Projects

Funds are provided to counties participating in LIRAP for implementation of air quality 

improvement strategies through local projects and initiatives. In the HGB area, LIP funding is 

available to the five counties participating in LIRAP: Brazoria; Fort Bend; Galveston; Harris; 

and Montgomery.

Brazoria, Fort Bend, and Galveston Counties used LIP funds to purchase buses and initiate a 

new park-and-ride transit service in 2010. LIP continues to maintain the park-and-ride funding 

as of 2013. The transit service links county residents with the Texas Medical Center area and 

creates immediate and long-term benefits for reducing emissions and congestion by decreasing 

single occupancy vehicle trips from U.S. Route 59.

Harris County used LIP funds in 2010 to establish the Harris County Clean Air Emissions Task 

Force and initiate an emissions enforcement program. The enforcement program targets highemitting vehicles, smoking vehicles, and suspicious vehicles to verify that the state safety and 

emissions inspection windshield certificates on these vehicles are legitimate and in compliance 

with air quality standards. The task force’s objective is to reduce the number of fraudulent, 

fictitious, or improperly issued safety and emissions inspection windshield certificates. The task 

force partners with local and state agencies to enforce state laws, codes, rules, and regulations 

regarding air quality and mobile emissions in Harris County. The citizens of Harris County and 

the entire southeast Texas region stand to benefit from this program as a result of the reduction 

in NOX emissions from each vehicle brought into emissions compliance.
Page 29

Montgomery County used LIP funds for signal light synchronization projects in FY 2010 and 

2012. Synchronizing traffic signalization reduces idling by decreasing the number of times a 

vehicle must stop at a traffic light. The “Exhaust Phase” of an engine emits the most emissions 

during starting, idling, and breaking stationary inertia. Synchronizing traffic signalization 

reduces both idling and the number of times a vehicle must resume travel, i.e., break stationary 

inertia. The project increases the emissions reduction benefits by synchronizing the traffic 

signalization upon real-time traffic flow instead of a stagnate model to better manage peak-hour 

congestion, while minimizing cross-traffic congestion, and reducing emissions.

3.3.11 Other Local Programs

In the 2010 HGB AD SIP Revision, H-GAC submitted the following programs that were not 

committed to as either transportation control measures or Voluntary Mobile Emission 

Reduction Program measures but may be implemented locally in the HGB area. Updates to 

these programs were included in the Houston-Galveston-Brazoria 1997 Eight-Hour Ozone 

Standard Nonattainment Area Motor Vehicle Emissions Budgets Update State Implementation 

Plan Revision adopted in April 2013 (2013 MVEB SIP Revision). For a detailed analysis of these 

programs, see Appendix F of the 2010 HGB AD SIP Revision, and Section 5.4.3.13: Other Local 

Programs and Section 5.4.3.14: Additional Strategies Not Included in the 2010 HGB AD SIP 

Revision of the 2013 MVEB SIP Revision.

• Scrappage and Buy-Back Plan

• Limitations on Heavy-Duty Vehicles Idling; Creation of Regional Government Idling 

Restrictions

• Encourage/Mandate Livable Centers

• Enhanced Enforcement of Smoking Vehicles

• Limitation on Idling of Heavy-Duty Construction Equipment

• Airport Emission Reduction Strategy

• Congestion Pricing/High Occupancy Vehicle (HOV) Lanes and High Occupancy Toll (HOT)

Lane Conversion

• Flextime

• Parking Pricing

• PHA Automated Gate Systems 

• Third-Party TERP Grants

3.4 Control Strategies Summary

The permanent and enforceable VOC and NOX control measures contained in Section 3.2: List of 

Existing Control Measures of this report have resulted in air quality improvement in the HGB 

area. These enforceable measures will remain in place to ensure continued maintenance of the 

one-hour ozone NAAQS in the HGB area. In addition, Section 3.3: Additional Measures lists 

control measures that may not meet all of the EPA’s standard tests of creditability (permanent,

enforceable, surplus, and quantifiable) but are crucial to the success of the air quality plan in the 

HGB area. Implementation of these control measures will contribute to the continued 

maintenance of the one-hour ozone NAAQS and attainment of the 1997 and 2008 ozone 

NAAQS. The TCEQ continues to seek innovative air quality improvement measures and 

technologies to implement in the HGB area.
Page 30

SECTION 4: MAINTENANCE DEMONSTRATION

4.1 General

The redesignation substitute (RS) report is intended to demonstrate that the HoustonGalveston-Brazoria (HGB) area will remain in attainment of the one-hour ozone National 

Ambient Air Quality Standard (NAAQS) for the 10-year period following the date that antibacksliding obligations under the revoked standard would be lifted. Since removing antibacksliding obligations is contingent upon the United States Environmental Protection Agency’s 

(EPA) approval, the Texas Commission on Environmental Quality (TCEQ) has set a horizon year 

of 2026. Setting the horizon date at 12 years from the date this report was developed allows 

more than adequate time for review and approval before the 10-year period begins. This tenyear period also aligns with the EPA’s requirement of maintenance plans to demonstrate 

attainment for a ten-year period following the date of redesignation.

The most current emissions inventory (EI) data were analyzed as part of this maintenance 

demonstration. The 2011 periodic inventory was chosen as the starting point for the analyses 

presented in this section since it was the most recent periodic inventory year. Specifically, the 

ten years prior to monitoring attainment of the one-hour ozone NAAQS (2002 through 2011) 

were analyzed to develop trend data. During this time, the HGB area EI showed a significant 

decrease in ozone precursor emissions from all source categories, which contributed to the 

attainment of the one-hour ozone NAAQS. These reductions were accomplished through a 

variety of federal, state, and local regulations and programs as detailed below.

4.2 Emissions Inventory Trends

From 2002 to 2011, overall anthropogenic ozone precursor emissions in the HGB 

nonattainment area declined substantially as a result of regulations implemented at the federal, 

state, and local levels and innovative programs implemented by the TCEQ. As demonstrated in 

Figure 4-1: HGB Eight-County Nonattainment Area Historical NOX Emissions Trends and 

Figure 4-2: HGB Eight-County Nonattainment Area Historical VOC Emissions Trends, 

anthropogenic volatile organic compounds (VOC) emissions have decreased 30%, and 

anthropogenic nitrogen oxides (NOX) emissions have decreased 46%. Both 30 Texas 

Administrative Code (TAC) Chapter 115: Control of Air Pollution from Volatile Organic

Compounds and 30 TAC Chapter 117: Control of Air Pollution from Nitrogen Compounds

regulations implemented from 1999 through 2006 along with implementation of the Mass 

Emissions Cap and Trade (MECT) program have significantly reduced overall ozone precursor 

emissions at both major and minor (point and area) industrial, commercial, and institutional 

sources in the HGB ozone nonattainment area. Innovative emissions reduction programs such 

as the Texas Emissions Reduction Plan and the AirCheckTexas Drive a Clean Machine program 

in 30 TAC Chapter 114: Control of Air Pollution from Motor Vehicles have also reduced mobile 

source emissions, the primary source of NOX emissions in the HGB area.
Page 31

Note: The 2002, 2005, and 2008 on-road mobile values were generated using the MOBILE6 model while the 2011 

value was generated using the MOVES2010b model. The upward trend from 2008 to 2011 for on-road mobile is 

due to the different NOX calculation methodologies between MOBILE6 and MOVES. If MOVES-based trends were 

available for 2002 through 2011, a downward trend would be seen throughout.

Figure 4-1: HGB Eight-County Nonattainment Area Historical NOX Emissions 

Trends

27.79 16.04 25.41

21.15

322.67

260.98

190.58

213.57

145.25

156.04

149.24

121.11

339.49

194.52

111.38

108.48

0.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

400.00

2002 2005 2008 2011

Emissions in Tons Per Day

Area

On-Road

Non-Road

Point
Page 32

Note: The 2002, 2005, and 2008 on-road mobile values were generated using the MOBILE6 model while the 2011 

value was generated using the MOVES2010b model.

Figure 4-2: HGB Eight-County Nonattainment Area Historical VOC Emissions 

Trends

4.3 2011 Attainment Inventory

The 1990 Federal Clean Air Act (FCAA) Amendments require that EIs be prepared for ozone 

nonattainment areas. Because ozone is photochemically produced in the atmosphere when VOC 

mixes with NOX in the presence of sunlight, the TCEQ must compile information on the sources 

of these precursor pollutants. The EI must identify the source types present in an area, the 

amount of each pollutant emitted, and the types of processes and control devices employed at 

stationary sources or other source categories. The EI provides data for a variety of air quality 

planning tasks, including establishing baseline emission levels, calculating reduction targets, 

control strategy development for achieving the required emission reductions, emission inputs 

into air quality simulation models, and tracking actual emission reductions against the 

established emissions growth and control budgets.

The attainment inventory for the HGB area is based on the VOC and NOX emissions that occur 

on an actual typical summer weekday. Consistent with a September 4, 1992 EPA memorandum 

entitled Procedures for Processing Requests to Redesignate Areas to Attainment, the 

attainment EI base year may be any one of the three years used to determine the design value 

for the attainment year. For this RS report, the attainment EI base year is 2011 because it is the 

year of the most recent periodic emissions inventory (PEI) and one of the three years used to 

determine the design value for the 2013 attainment year. The total VOC and NOX EI for the area 

115.34

106.58

96.37

85.05 82.79

72.28

62.65

49.92

149.37

140.08

108.10

96.11

422.14

425.83

446.60

308.74

0.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

400.00

450.00

500.00

0.00

20.00

40.00

60.00

80.00

100.00

120.00

140.00

2002 2005 2008 2011

Emissions in Tons Per Day

On-Road

Non-Road

Point

Area
Page 33

is summarized from the estimates developed for four general categories of anthropogenic 

emissions sources, which are each explained in Section 4.3.1: Area Sources, Section 4.3.2: OnRoad Mobile Sources, Section 4.3.3: Non-Road Mobile Sources, and Section 3.4.4: Stationary 

Point Sources. Summaries of the 2011 VOC and NOX emissions by source type are provided in 

Section 4.4: Emissions Summary.

4.4 Future Emissions and Verification of Continued Attainment

To track progress of the HGB area toward continued attainment of the one-hour ozone NAAQS, 

the TCEQ will develop and submit periodic EIs to the EPA every three years as required by the 

federal Air Emissions Reporting Requirements (AERR) rule. The 2011 inventory was the first 

PEI submitted under the AERR. Per the AERR, the 2011 PEI was reported to the EPA’s National 

Emissions Inventory (NEI) as a comprehensive and detailed estimate of air emissions, including 

ozone precursors (NOX and VOC). As directed by the AERR, the 2011 Texas PEI includes annual 

emissions for the entire state and summer weekday emissions for the 2008 eight-hour ozone 

nonattainment areas in Texas, including the HGB area. States can rely on periodic AERR EI 

submittals to satisfy ongoing state implementation plan (SIP) EI submission requirements every 

three years. The periodic EI SIP revision submission requirements would occur in the same 

years as the AERR submittals.

Because the EPA has not made guidance available for how to demonstrate verification of 

continued attainment in an RS, the TCEQ is using the method outlined in the EPA’s 

redesignation guidance9

. Future emissions for the HGB area were projected from the base year 

inventory (2011) to a future year (horizon year) of 2026, 12 years from the time this RS will be

submitted to the EPA. Projecting emissions to 2026 aligns with the EPA’s requirement of 

maintenance plans to demonstrate attainment for a 10-year period following the date of 

redesignation. The requirement for verification of continued attainment is satisfied when the 

state demonstrates that future VOC and NOX emissions levels are not expected to result in 

exceedances of the one-hour ozone NAAQS.

Future emissions were projected to the horizon year 2026 using three-year intervals. A 

summary of the base year inventory and the future year inventories for ozone precursor 

emissions is presented in Section 4.4.

4.4.1 Area Sources

Stationary source emissions data from sites and processes that do not meet the reporting 

requirements for point sources are classified as area sources. Area sources are small-scale 

industrial, commercial, and residential sources that generate emissions. Emissions are 

calculated and recorded on the county level. Examples of area sources include: printing 

operations; industrial coatings; degreasing solvents; house paints; gasoline service station 

underground tank filling; vehicle refueling operations; stationary source fossil fuel combustion;

outdoor refuse burning; and structural fires. With some exceptions, area source emissions are 

calculated by multiplying an established emissions factor (emissions per unit of activity) by the 

appropriate activity or activity surrogate responsible for generating emissions. Population is one 

of the more commonly used activity surrogates for area sources. Other activity data include the 

amount of gasoline sold in an area, employment by industry type, and crude oil and natural gas 

production.

 9 Memorandum from John Calcagni, Director of Air Quality Management Division, September 4, 1992, 

Procedures for Processing Requests to Redesignate Areas to Attainment. EPA Office of Air Quality 

Planning and Standards.
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4.4.1.1 Updated 2011 Base Year Inventories

The 2011 area source inventory was developed per the AERR reporting requirements. The 2011

inventory was created using a combination of methodologies and data: EPA-generated EIs;

TCEQ-contracted projects; TCEQ staff projects; and categories grown from the 2008 EI using 

factors derived from study data compiled by Eastern Research Group (ERG), the Economic and 

Consumer Credit Analytics website (http://www.economy.com/default.asp), and the United 

States Energy Information Administration’s (EIA) annual energy outlook publication. The 

documentation for the development of the ERG study factors can be found in Attachment A: 

Projection Factors for Point and Area Sources.

The EPA developed EIs for states to use for many source categories as part of the NEI. The 

states access these individual inventories through the EPA’s NEI website 

(ftp://ftp.epa.gov/EmisInventory/2011nei/doc/). These source categories include but are not 

limited to: industrial coatings; degreasing; residential, commercial/institutional, and industrial 

fuel use; commercial cooking; aviation fuel use; and consumer products. For some source 

categories, the TCEQ developed state-specific emissions estimates by acquiring current statespecific activity data and applying appropriate emissions factors. These source categories 

include but are not limited to: storage tanks; structural fires; dry cleaners; and automobile fires.

In particular, significant resources were expended to improve the oil and gas area source 

inventory production categories for the 2011 inventory. The improvements included the 

development and refinement of a state-specific oil and gas area source emissions calculator. This 

oil and gas area source emissions calculator uses county-level production and local equipment 

activity data with local emissions requirements to estimate emissions from individual 

production categories including compressors engines, condensate and oil storage tanks, loading 

operations, heaters, and dehydrators. The documentation for the development of the oil and gas 

emissions calculator can be found in Attachment B: Characterization of Oil and Gas Production 

Equipment and Develop a Methodology to Estimate Statewide Emissions. A significant 

improvement made to the oil and gas calculator for the 2011 inventory was the development of 

refined emission factors for VOC emissions from condensate storage tanks. The documentation 

for the refined emission factors can be found in Attachment C: Condensate Tank Oil and Gas 

Activities.

For those area source categories affected by TCEQ rules, rule effectiveness factors are applied to 

the baseline or uncontrolled emissions to estimate controlled emissions. These factors address 

the efficiency of the controls and the percentage of the category’s population affected by the rule. 

Quality assurance of area source emissions involves ensuring that the activity data used for each 

separate category is current and valid. Data such as current population figures, fuel usage, and 

material usage were updated and the EPA guidance on emission factors was used. Other routine 

efforts such as checking calculations for errors and conducting reasonableness and 

completeness checks were implemented.

4.4.1.2 Updated Milestone Years Inventories

The updated milestone year inventories for the area source categories were developed using 

factors derived from Attachment A, the Economic and Consumer Credit Analytics website 

(http://www.economy.com/default.asp), and the EIA’s annual energy outlook publication. The 

ERG-derived factors contain individual growth factors for each category and for each forecasting 

year. This projection method is the EPA standard, accepted method for developing future year 

EIs.
Page 35

4.4.1.3 Area Source Emissions Inventories

The 2011 area source NOX and VOC emissions totals for the eight-county HGB 2008 eight-hour 

ozone nonattainment area are presented in Table 4-1: HGB 2011 Area Source NOX and VOC 

Emissions (tons per day).

Table 4-1: HGB 2011 Area Source NOX and VOC Emissions (tons per day)

Pollutant 2011 2014 2017 2020 2023 2026

NOX 21.15 22.19 22.90 23.28 23.17 23.23

VOC 308.74 321.92 332.43 339.67 342.58 346.13

4.4.2 On-Road Mobile Sources

On-road mobile emission sources consist of automobiles, trucks, motorcycles, and other motor 

vehicles traveling on public roadways. On-road mobile source emissions are usually categorized 

as either combustion-related emissions or evaporative hydrocarbon emissions. Combustionrelated emissions are estimated for vehicle engine exhaust. Evaporative hydrocarbon emissions 

are estimated for the fuel tank and other evaporative-leak sources on the vehicle. To calculate 

emissions, both the rate of emissions per unit of activity (emissions factors) and the number of 

units of activity must be determined. The emissions factors for on-road mobile sources are 

determined using models developed and approved by the EPA. The models allow for input of 

local conditions and vehicle characteristics. The activity information corresponding to the 

emissions factors is obtained using local travel demand models (TDMs), the output from the 

highway performance monitoring system, and speed models.

In March 2010, the EPA released the Motor Vehicle Emissions Simulator (MOVES) as the

official emissions factor model for developing on-road mobile source category EIs. Although 

MOVES represented a new approach to assessing on-road emissions, the sources are the same, 

and the opportunity to use local inputs for meteorological conditions, control programs, and 

fleet characteristics remains. When using MOVES in emission-rates mode, emission rates are 

produced for subsets of the on-road fleet, and the emission rates are multiplied by the activity 

level of each vehicle type or source-use type to calculate emissions. The EPA prefers that states 

use the latest version of MOVES that is available. The EPA released MOVES2010b in April 2012 

and an updated MOVES2010b database in October 2012. MOVES2010b with the October 2012 

database updates was used in the inventory development for all on-road HGB EIs.

In accordance with EPA guidance, if states have completed significant work on an inventory for 

periodic reporting or for a SIP revision when a new version of MOVES is released, such work can 

be completed and submitted to EPA using the previous version of the model. The EPAannounced release date for an updated version of MOVES, MOVES2014, is July 2014. The 

schedule for the inventory development for this HGB RS report did not allow time to 

incorporate MOVES2014.

To estimate on-road mobile source emissions, emissions rates calculated by the MOVES model 

must be multiplied by the level of vehicle activity. On-road mobile source emissions factors are 

expressed in units of grams per mile; therefore, the activity information that is required to 

complete the inventory calculation is vehicle miles traveled (VMT) in units of miles per day. The 

level of vehicle travel activity is developed using a TDM run by the Texas Department of 

Transportation or by the local metropolitan planning organization. The TDMs are validated 

against a large number of ground counts, i.e., traffic passing over counters placed in various 
Page 36

locations throughout a county or area. For SIP and reporting inventories, VMT estimates are 

calibrated against outputs from the federal highway performance monitoring system, a model 

built from a different set of traffic counters.

In addition to the number of miles traveled on each roadway link, the speed on each roadway 

type or segment is also needed to complete an on-road EI. Roadway speeds, required inputs for 

the MOVES model, are calculated by using the activity volumes from the TDM and a postprocessor speed model.

4.4.2.1 On-Road Mobile Source Emissions Inventories

The 2011, 2014, 2017, 2020, 2023, and 2026 on-road mobile source EIs for the HGB RS were 

developed using the latest available data, current emissions factors and models, and the most 

current planning assumptions. The inventories include the eight HGB-area counties designated 

as nonattainment for the one-hour ozone NAAQS. On-road inventory estimates were developed 

under contract by the Texas Transportation Institute (TTI). Consistent with on-road inventory 

development procedures for reporting requirements and rate of further progress, the on-road 

inventories for each of these calendar years are based on VMT estimates and emission rates for 

an average summer work weekday. MOVES2010b, which is the latest available version of the 

EPA’s MOVES model, was used to estimate the summer weekday emission rates in units of 

grams per mile for NOX and VOC. The roadway link-level VMT estimates were obtained from 

travel demand modeling for the eight-county HGB area for each analysis year. A summary of the 

on-road mobile source VMT used to develop the various NOX and VOC emissions levels is 

presented in Table 4-2: HGB VMT (miles per average summer day). The HGB on-road mobile 

source 2011, 2014, 2017, 2020, 2023, and 2026 EIs for NOX and VOC are summarized in Table

4-3: HGB Average Summer Weekday NOX and VOC Emissions for On-Road Mobile Sources 

(tons per day). For complete documentation of the development of the on-road mobile source 

EIs for this HGB RS including the inventory development methods, MOVES inputs, and the 

results, refer to Attachment D: MOVES2010b-Based On-Road Inventories in Support of the 

HGB Ozone Nonattainment Area Redesignation Substitute Analysis. The complete set of input 

and output files are available from the TCEQ Air Quality Division upon request.

Table 4-2: HGB VMT (miles per average summer day)

Description 2011 2014 2017 2020 2023 2026

Vehicle Miles 

Traveled 150,968,794 144,916,411 151,890,390 159,509,450 167,539,317 176,004,008

Table 4-3: HGB Average Summer Weekday NOX and VOC Emissions for On-Road 

Mobile Sources (tons per day)

Pollutant 2011 2014 2017 2020 2023 2026

NOX 181.28 127.70 88.85 69.80 59.28 54.51

VOC 80.92 60.43 46.51 40.51 38.09 36.93

4.4.2.2 On-Road Mobile Source Control Strategies

The on-road mobile EIs for each HGB RS analysis year were developed using emission factors 

that reflect all control strategies for each analysis year except for the Tier 3 Federal Motor 

Vehicle Control Program (FMVCP) that will begin implementation in 2017. The controls that 
Page 37

were modeled include: pre-1990 FMVCP, fleet turnover to Tier 1 of the FMVCP, fleet turnover to 

Tier 2 of the FMVCP, the 2007 heavy duty diesel FMVCP, summer reformulated gasoline (RFG), 

the HGB vehicle inspection and maintenance (I/M) program, the HGB anti-tampering program, 

and Texas Low Emission Diesel (TxLED). The Tier 3 FMVCP was finalized in March 2014 and 

will begin implementation in 2017. Although the 2017, 2020, 2023, and 2026 emissions in this

HGB RS report will be reduced when the effects of Tier 3 are included, MOVES2010b was 

released before the final Tier 3 rule took effect and does not include Tier 3 benefits. A summary 

of the HGB on-road mobile source control strategies used for the HGB RS are presented in Table 

4-4: HGB On-Road Mobile Control Strategies Summary.

Table 4-4: HGB On-Road Mobile Control Strategies Summary

Control Program 

Description

Year Control 

Program Started

Control Scenario Notes

Pre-1990 FMVCP Pre-1990 Included for 2011, 2014, 2017, 2020, 2023, and 2026

Anti-Tampering Program 1986 Included for 2011, 2014, 2017, 2020, 2023, and 2026

1992 Federal Controls on 

Gasoline Volatility 1992

Maximum Reid Vapor Pressure of 7.8 pounds per 

square inch

Included for 2011, 2014, 2017, 2020, 2023, and 2026

Tier 1 FMVCP 1994 Included for 2011, 2014, 2017, 2020, 2023, and 2026

RFG Phase 1 1995 for Phase 

One Superseded by RFG Phase 2

I/M Program 1997 Included for 2011, 2014, 2017, 2020, 2023, and 2026

RFG Phase 2 2000 for Phase 

Two Included for 2011, 2014, 2017, 2020, 2023, and 2026

National Low Emission 

Vehicle (NLEV) Program 2001 Included for 2011, 2014, 2017, 2020, 2023, and 2026

Tier 2 FMVCP 2004 Phase in 2004 to 2009

Included for 2011, 2014, 2017, 2020, 2023, and 2026

TxLED 2006

Low aromatic hydrocarbon and high cetane number 

to control NOX

Included for 2011, 2014, 2017, 2020, 2023, and 2026

Federal Low-Sulfur 

Highway Diesel 2006 15 parts per million maximum sulfur contentIncluded for 2011, 2014, 2017, 2020, 2023, and 2026

2007 Heavy Duty FMVCP 2007 Phase in 2007 to 2010

Included for 2011, 2014, 2017, 2020, 2023, and 2026

Tier 3 FMVCP 2017

Not final until March 2014, Effects are not included 

in MOVES2010b, effects not included for any HGB 

RS Scenarios

If included, 2017, 2020, 2023, and 2026 emissions 

would be lower

Due to the on-road mobile source control programs in place for each analysis year, the on-road 

NOX and VOC emissions are steadily decreasing from the base year of 2011 to each milestone 

year and the 2026 horizon year despite growth in VMT. A summary of the tons per day (tpd)

change from the 2011 base year to each milestone year and the horizon year are summarized in 
Page 38

Table 4-5: Estimated Reductions from 2011 Baseline Due to FMVCP, I/M, RFG, and TxLED 

(tons per day). A summary of the percent change in NOX and VOC from the 2011 base year to 

each milestone year and the horizon year are summarized in Table 4-6: Estimated Percent 

Reductions from 2011 Baseline Due to FMVCP, I/M, RFG, and TxLED.

Table 4-5: Estimated Reductions from 2011 Baseline Due to FMVCP, I/M, RFG, and

TxLED (tons per day)

Inventory Year NOX VOC

2011 0 0

2014 -53.58 -20.49

2017 -92.43 -34.41

2020 -111.48 -40.41

2023 -122.00 -42.83

2026 -126.77 -43.99

Table 4-6: Estimated Percent Reductions from 2011 Baseline Due to FMVCP, I/M, 

RFG, and TxLED

Inventory Year NOX VOC

2011 0.0 0.0

2014 -29.6 -25.3

2017 -51.0 -42.5

2020 -61.5 -49.9

2023 -67.3 -52.9

2026 -69.9 -54.4

4.4.3 Non-Road Mobile Sources

Non-road vehicles do not typically operate on roads or highways and are often referred to as offroad or off-highway vehicles. The non-road source category is composed of a diverse collection 

of equipment. Non-road emissions sources include but are not limited to: agricultural 

equipment; construction and mining equipment; lawn and garden equipment; aircraft and 

airport equipment; locomotives; commercial marine vessels (CMV); and drilling rigs. EIs for 

non-road sources developed as subcategories include: NONROAD model categories; airports; 

CMVs; drilling rigs; and locomotives. The following sections describe the emissions calculation 

methods used for the non-road mobile source subcategories.

4.4.3.1 Updated 2011 Base Year Inventories

A Texas-specific version of the EPA’s latest NONROAD 2008a model, called the Texas 

NONROAD (TexN) model, was used to calculate emissions for all non-road mobile source 

equipment and recreational vehicles, with the exception of airports, locomotives, CMVs, and 

drilling rigs. Several equipment survey studies have been conducted that focused on various 

equipment categories operating in different areas in Texas. The resulting survey data are used as 

inputs to the TexN model to more accurately estimate non-road emissions for the State of Texas. 

The 2011 EI development used the meteorological data, and fuel data collected for the calendar 

year 2011.
Page 39

The 2011 airport emission sources include aircraft engines, auxiliary power units, and ground 

support equipment. The United States Federal Aviation Administration’s Emissions and 

Dispersion Modeling System, Version 5.1.3 (EDMS) was used to calculate airport source 

emissions. To estimate the 2011 emissions from the airport sources, a survey was conducted by 

ERG under contract with the TCEQ to collect updated information on aircraft activity, fleet mix, 

and EDMS model input parameters. Documentation of methods and procedures used in 

developing HGB area 2011 airport EI can be found in Attachment E: Development of Statewide 

Annual Emissions Inventory and Activity Data for Airports.

The 2011 Texas locomotive EI includes Class I, II, and III locomotive activity and emissions by 

rail segment for all counties within Texas. Locomotive line-haul and yard activity data were 

compiled from companies operating in Texas to create a county-level Class I line-haul inventory. 

Data developed by Eastern Regional Technical Advisory Committee in collaboration with the 

Federal Railroad Administration, the American Short Line and Regional Railroad Association 

(ASLRRA), and members of the Class II and III railroad communities used 2008 activity and 

emissions profiles for Class II and Class III railroads. To calculate annual gallons of fuel used by 

railroads, data compiled by ASLRRA from the Class II and III railroads, including total industry 

fuel use in 2008 for locomotives and total Class II/III route miles, were used. Based on the EIA’s

latest annual energy outlook publication, 2008 fuel usage values were grown to estimate 2011 

emissions. Documentation of methods and procedures used in developing the locomotive EIs 

can be found in Attachment F: 2011 Texas Railroad Emission Inventory Report.

The 2011 CMV EI was based on 2011 activity data compiled using local port data and data from 

the United States Department of Transportation Maritime Administration. The EPA’s updated 

2011 emissions factors were used to account for vessel turnover and compliance with marine 

vessel air quality regulations. The emissions factors were applied to the 2011 activity values to 

calculate 2011 emissions. The emissions were spatially allocated to geographic information 

system (GIS) shapefiles. Documentation of methodologies and procedures used in developing

the CMV EIs can be found in Attachment G: Development of 2011 Statewide Toxics and Actual 

Annual and Ozone Season Weekday Emissions Inventories for Commercial Marine Vessels.

The 2011 inventory for the drilling rig diesel engines was developed based on a statewide EI 

improvement study and updated with 2011 activity data. A survey of oil and gas exploration and 

production companies was used to develop improved drilling rig emissions characterization 

profiles. Documentation of methods and procedures used in developing the drilling rig diesel 

engine EIs can be found in Attachment H: Development of Texas Statewide Drilling Rigs 

Emissions Inventories for the Years 1990, 1993, 1996, and 1999 through 2040 or online at 

http://www.tceq.texas.gov/assets/public/implementation/air/am/contracts/reports/ei/582119

9776FY1105-20110815-ergi-drilling_rig_ei.pdf. The drilling rig emissions characterization 

profiles from this study were combined with 2011 drilling activity data obtained from the 

Railroad Commission of Texas (RRC) to develop the 2011 inventory.

4.4.3.2 Updated Milestone Years Inventories

The updated milestone year inventories for the NONROAD model categories were developed 

using the most recent TexN/NONROAD2008a model. The TexN model runs were performed for 

the analyses years 2014, 2017, 2020, 2023, and 2026 to estimate the ozone season daily 

emissions for the NONROAD model categories. Unlike the NONROAD 2008a model that uses 

one state-level population file, the TexN model contains unique population files for all 254 Texas 

counties. Population files in TexN have been developed for every possible analysis year (1970 to 

2050) within the TexN model, utilizing county and source category classification-specific growth 

factors. Due to fluctuations in engine activity and their associated surrogates, the TexN 
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population files are periodically updated using the most recent growth factors such as those 

available via Economy.com to allow for more accurate forecasting and back-casting of 

emissions.

The updated milestone year inventories for the airport sources were based on the study 

Projection Factors for Point and Area Sources developed by ERG (see Attachment A), the 2011 

airport EI data, and projections using Federal Aviation Association’s Terminal Area Forecast 

data.

The updated milestone year inventories for locomotives were based on the data developed by 

ERG in the final version of the 2011 NEI. The emissions rate adjustment factors used for 

projections by source classification code can found in the EPA’s fact sheet, Emission Factors for 

Locomotives (http://www.epa.gov/otaq/regs/nonroad/locomotv/420f09025.pdf).

The updated milestone year inventories for CMV sources were based on the data developed by 

ERG in the final version of the 2011 NEI and projections using trend data developed by E.H. 

Pechan & Associates, Inc. found in Attachment I: Development of Locomotive and Commercial 

Marine Emissions Inventory - 1990 to 2040.

The updated milestone year inventories for drilling rigs were based on the 2011 inventory 

developed using the drilling rig emissions characterization profiles from the ERG report in 

Attachment H combined with 2011 drilling rig activity data from the RRC. The 2011 inventory 

was then projected to future years using growth factors. Documentation on the development of 

growth factors can be found in Attachment A.

4.4.3.3 Non-Road Mobile Source Emissions Inventories

The 2011 non-road category source NOX and VOC emissions totals for the eight-county HGB 

area are presented in Table 4-7: HGB 2011 NOX Emissions for Non-Road Categories (tons per 

day) and Table 4-8: HGB 2011 VOC Emissions for Non-Road Categories (tons per day).

Table 4-7: HGB 2011 NOX Emissions for Non-Road EI Categories (tons per day)

Category 2011 2014 2017 2020 2023 2026

NONROAD Model 57.20 44.53 34.51 27.28 23.14 20.92

Airport 8.66 9.45 10.30 11.22 12.25 13.38

Locomotive 18.03 16.10 14.99 14.30 13.19 11.32

Commercial Marine Vessels 36.74 36.44 34.71 30.40 26.46 22.86

Drilling Rigs 0.48 0.47 0.48 0.50 0.50 0.50

Total 121.11 106.99 94.99 83.70 75.54 68.98
Page 41

Table 4-8: HGB 2011 VOC Emissions for Non-Road EI Categories (tons per day)

Category 2011 2014 2017 2020 2023 2026

NONROAD Model 45.63 34.24 29.17 26.58 25.66 25.43

Airport 1.88 1.80 1.95 2.10 2.30 2.49

Locomotive 1.04 0.85 0.75 0.67 0.61 0.52

Commercial Marine Vessels 1.33 1.40 1.43 1.46 1.49 1.53

Drilling Rigs 0.04 0.04 0.04 0.05 0.05 0.05

Total 49.92 38.33 33.34 30.86 30.11 30.02

4.4.4 Stationary Point Sources

4.4.4.1 Emissions Inventory Development

Stationary point source emissions data are collected annually from sites that meet the reporting 

requirements of 30 TAC §101.10. To collect the data, the TCEQ sends notices to all sites 

identified as potentially meeting the reporting requirements. Companies are required to report 

emissions data and to provide sample calculations used to determine the emissions. Information 

characterizing the process equipment, the abatement units, and the emission points is also 

required.

All data submitted in the emissions inventory questionnaire (EIQ) are reviewed for qualityassurance purposes and then stored in the State of Texas Air Reporting System (STARS) 

database. EIQ guidance documents and historical point source emissions of major pollutants are 

available on the TCEQ’s Point Source Emissions Inventory Web page 

(https://www.tceq.texas.gov/airquality/point-source-ei/psei.html). Additional information is 

available upon request from the TCEQ’s Air Quality Division.

4.4.4.2 Updated 2011 Base Year Inventory

The TCEQ extracted the 2011 point source inventory data from STARS on February 13, 2014. 

The extracted data included reported annual and ozone season daily emissions of NOX and VOC 

for each site in the HGB area for which a 2011 EIQ was submitted and reflected revisions made 

on or before the extract date. The TCEQ designated the 2011 inventory as the base year because 

it was the most recent NEI year available.

4.4.4.3 Updated Milestone Year Inventories

When developing the milestone year inventories, the TCEQ used the 2012 EI as a baseline for 

projections. 

The TCEQ designated the 2012 inventory as the baseline year for projections because it was the 

most recent finalized point source EI data available. The TCEQ extracted the 2012 point source 

inventory data from STARS on February 18, 2014. The extracted data included reported annual 

and ozone season daily emissions of NOX and VOC for each site in the HGB area that submitted 

a 2012 EIQ and reflected revisions made on or before the extract date.

NOX emissions from sites containing equipment applicable to the MECT program were 

projected using MECT data. MECT data were reviewed to identify sites with applicable units. 

For each of these sites, it was assumed that the significant majority of NOX emissions are from

MECT applicable units. Since the MECT cap is an annual value, it was prorated by the ratio of 

the aggregate of the 2012 ozone season daily emissions to the aggregate of the 2012 annual 
Page 42

emissions for applicable sites to project future daily emissions for the HGB area. To maintain a 

conservative approach, the entire cap was applied to the aggregate of the site emissions in the 

first milestone year inventory.

VOC emissions from sites identified as major sources of VOC emissions were projected using the 

major modification threshold for severe ozone nonattainment areas. Title V operating permit 

data from 2012 were reviewed to identify major sources of VOC emissions. For each site, the 

annual 25-ton major modification threshold was prorated by the site-wide ratio of ozone season 

to annual emissions to provide a one-time growth limit added to the site’s 2012 emissions. To 

maintain a conservative approach, all growth was taken into account for the first milestone year 

inventory.

NOX emissions from sites not listed in the MECT and VOC emissions from sources not identified 

as major sources of VOC emissions were projected using emissions trend data and growth 

factors. Emission trends for each site were established using 2009 through 2012 annual 

emissions data. For sites with decreasing emission trends, milestone year inventories were set 

equal to the 2012 baseline inventory. For sites with increasing emission trends, milestone year 

inventories were determined by applying growth factors to the 2012 baseline inventory. The

growth factor information can be found in Attachment A. To maintain a conservative approach, 

any growth factors that projected a decrease in future emissions were modified so that emissions

for these source categories remained constant through future years.

Finally, the milestone year inventories were adjusted to account for emissions credits. Emissions 

credits are banked emissions reductions that may return to the airshed in the future. To account 

for the possible use of the banked NOX and VOC emissions, available Emissions Reduction 

Credit (ERC) and Discrete Emissions Reduction Credit (DERC) data were applied to the 

inventories.

Banked ERC use was determined based on New Source Review permitting offsets with a severe 

nonattainment offset ratio of 1.3 to 1 applied to such credits. ERCs listed in the Emissions 

Banking and Trading database as of February 24, 2014 were used. All of the banked ERCs were 

assumed to be allocated by 2017. The ERC transactions from 2008 to 2014 were also applied.

Banked DERCs were projected based on historical data with a 10% environmental contribution 

deduction under the assumption that DERCs will be used to meet 30 TAC Chapter 115 and/or 

Chapter 117 emissions standards. Available credits were averaged over the projected timespan. 

This approach is conservative and simplified; historical use has been considerably less10. DERCs 

listed in the Emissions Banking and Trading database as of February 18, 2014 were used. Past 

DERC transactions were not considered because of the short-term nature of DERCs.

A summary of the point source inventories is presented in Table 4-9: HGB Point Source NOX 

and VOC Emissions (tons per day).

 10 Texas Commission on Environmental Quality. “Discrete Emission Credit Banking and Trading Program 

Audit.” Accessed March 6, 2014. http://www.tceq.texas.gov/assets/public/implementation/air/banking

/reports/2013decprogramaudit.pdf.
Page 43

Table 4-9: HGB Point Source NOX and VOC Emissions (tons per day)

Pollutant 2011 2014 2017 2020 2023 2026

NOX 108.48 126.31 126.82 127.01 127.20 127.39

VOC 96.11 100.81 102.86 103.29 103.71 104.12

4.5 Emissions Summary

The 2011 base year and the 2014, 2017, 2020, 2023, and 2026 future year EI summaries by 

source categories for the HGB area are shown in Table 4-10: HGB NOX Emissions by Source 

Category (tons per day) and Table 4-11: HGB VOC Emissions by Source Category (tons per 

day). These tables illustrate that in the horizon year of 2026, mobile sources (on-road and nonroad) contribute the most NOX emissions and area sources contribute the most VOC emissions. 

Contributions from biogenic emissions are not included in the summary because this analysis is 

limited to anthropogenic sources.

Table 4-10: HGB NOX Emissions by Source Category (tons per day)

Category 2011 2014 2017 2020 2023 2026

Point Sources 108.48 126.31 126.82 127.01 127.20 127.39

Area Sources 21.15 22.19 22.90 23.28 23.17 23.23

On-Road Mobile Sources 181.28 127.70 88.85 69.80 59.28 54.51

Non-Road Mobile Sources 121.11 106.99 94.99 83.70 75.54 68.98

Total 432.02 383.19 333.56 303.79 285.19 274.11

Table 4-11: HGB VOC Emissions by Source Category (tons per day)

Category 2011 2014 2017 2020 2023 2026

Point Sources 96.11 100.81 102.86 103.29 103.71 104.12

Area Sources 308.74 321.92 332.43 339.67 342.58 346.13

On-Road Mobile Sources 80.92 60.43 46.51 40.51 38.09 36.93

Non-Road Mobile Sources 49.92 38.33 33.34 30.86 30.11 30.02

Total 535.69 521.49 515.14 514.33 514.49 517.20

4.6 Maintenance Demonstration Conclusion

Trend analysis using the 2026 future year emissions shows an overall decrease of 176.40 tpd in 

combined NOX and VOC emissions for the HGB area. This net change includes a projected 18.49

tpd decrease in VOC and a 157.91 tpd decrease in NOX.

Previous photochemical modeling analysis for the HGB area shows that reducing NOX emissions 

is expected to be more effective in reducing the ozone design value than VOC reductions. 

Therefore, the projected 157.91 tpd decrease of NOX will reduce ozone design values more

effectively than the smaller 18.49 tpd decrease in VOC emissions. Based on future trends and 

previous photochemical analysis, the HGB area is projected to show continued attainment of the 

one-hour ozone standard through 2026.