Docket ID: EPA‐R06‐OAR‐2015‐0495

Technical Support Document

Addressing

Emissions Inventory and Reasonable Further Progress Plan for the

Dallas/Fort Worth Moderate 8‐Hour Ozone Nonattainment Area

June 2016

This is the Environmental Protection Agency’s (EPA’s) technical review of revisions to

the Dallas/Fort Worth (DFW) State Implementation Plan (SIP) submitted by the Texas

Commission on Environmental Quality (TCEQ) on July 10, 2015, (and a technical supplement to

such submittal, dated April 22, 2016)1 to address reasonable further progress (RFP)

requirements for the 2008 8‐hour ozone National Ambient Air Quality Standard (NAAQS or

standard) for the Moderate ozone nonattainment area. The July 2015 SIP revision also updates

the 2011 emissions inventory (EI) and establishes motor vehicle emissions budgets (MVEBs) for

2017. The TCEQ’s submittals and appendices are in the docket for this rulemaking and on the

TCEQ website.2

Within this technical support document (TSD), “we,” “us,” and “our” means the EPA.

A. Background

Ozone is a gas composed of three oxygen atoms. Ground‐level ozone is generally not

emitted directly from a vehicle’s exhaust or an industrial smokestack, but is created by a

chemical reaction between nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the

presence of sunlight and high ambient temperatures. Thus, ozone is known primarily as a

summertime air pollutant. NOx and VOCs are called “precursors” to ozone formation. Motor

vehicle exhaust and industrial emissions, gasoline vapors, chemical solvents and natural sources

emit NOx and VOCs. Urban areas tend to have high concentrations of ground‐level ozone, but

areas without significant industrial activity and with relatively low vehicular traffic are also

subject to increased ozone levels because wind carries ozone and its precursors hundreds of

miles from their sources. Repeated exposure to ozone pollution may cause lung damage. Even

at very low concentrations, ground‐level ozone triggers a variety of health problems including

aggravated asthma, reduced lung capacity, and increased susceptibility to respiratory illnesses

like pneumonia and bronchitis. It can also have detrimental effects on plants and ecosystems.

The TCEQ has been addressing ground level ozone in the DFW area for over two

decades. To wit, the counties of Collin, Dallas, Denton, and Tarrant (the “core” counties) were

 

1 The technical supplement provides detail on how Wise County meets the 15% emission reduction requirement

described later in this document, beginning in Section 2 on page 7 below. The data provided in the technical

supplement was included in the July 10, 2015 SIP submittal, but was not used in the State’s calculations because

the TCEQ did not realize it was necessary. The technical supplement is provided in the docket for this rulemaking,

posted at www.regulations.gov at the docket ID: EPA‐R06‐OAR‐2015‐0495.

2 To view the submittals on the TCEQ website, please see https://www.tceq.texas.gov/airquality/sip/dfw/dfw‐

latest‐ozone.
2

initially designated and classified as a Moderate nonattainment area (NAA) under the 1‐hour

ozone standard (November 6, 1991, 56 FR 56694) and later reclassified as Serious (February 18,

1998, 63 FR 8128). The DFW area attained the 1‐hour ozone standard in 2006 (73 FR 61357,

October 16, 2008) and has continued to meet that standard. On April 30, 2004, the EPA

designated the DFW area (consisting of Collin, Dallas, Denton, Ellis, Johnson, Kaufman, Parker,

Rockwall and Tarrant counties) as a Moderate NAA under the 1997 8‐hour ozone standard, with

an attainment date of June 15, 2010.3 However, the DFW area failed to attain the 1997 ozone

standard by June 15, 2010, and was reclassified as a Serious NAA (75 FR 79302, December 20,

2010). The DFW area ultimately attained the 1997 8‐hour ozone standard in 2014 (80 FR 52630,

September 1, 2015) and continues to meet that standard.4 On April 30, 2012, the EPA finalized

designations under the 2008 ozone standard (77 FR 30088, May 21, 2012). In that action, the

EPA designated Collin, Dallas, Denton, Ellis, Johnson, Kaufman, Parker, Rockwall, Tarrant and

Wise counties as a Moderate NAA (the 10‐county NAA).5

Section 110 of the Clean Air Act (CAA or Act) requires states to develop air pollution

regulations and control strategies to ensure that air quality meets the NAAQS established by

EPA. Such regulations and strategies are often adopted into each state’s SIP. We further define

a SIP as a set of air pollution regulations, control strategies, other means or techniques, and

technical analyses developed by the state, to ensure that the state meets the NAAQS. It is

required by section 110 and other provisions of the CAA. A SIP protects air quality primarily by

addressing air pollution at its point of origin. A SIP can be extensive, containing state

regulations or other enforceable documents, and supporting information such as emissions

inventories, monitoring networks, and modeling demonstrations. Each state must submit

regulations and control strategies to EPA for approval and incorporation into the federally‐

enforceable SIP.

Section 172 of the CAA addresses nonattainment plan provisions in general and Section

182 provides for plan submissions and requirements.

Section 182 of the CAA and EPA’s SIP Requirements Rule for the 2008 ozone standard

(SRR) require areas classified as Moderate or higher to submit a SIP revision that provides for

RFP. See 80 FR 12264 (March 6, 2015) and 40 CFR 51.1110. The RFP shows how the area will

achieve specific emissions reductions over a certain period of time. The EI is an estimation of

actual emissions of air pollutants in an area and for this RFP, we are focusing on emissions of

NOx and VOC, which are precursors to ozone formation. On November 12, 2014 (79 FR 67068),

we approved the RFP for the DFW Serious ozone NAA, which demonstrated required emissions

reductions for the nine‐county NAA through the end of calendar year 2012 and MVEBs for

2012. Pursuant to section 172(c)(9) of the Act, under the 2008 ozone standard, the RFP SIP for

the DFW Moderate NAA must demonstrate emissions reductions of at least three percent per

 

3 We refer to the DFW NAA for the 1997 ozone standard as, “the nine‐county NAA,” which consists of Collin,

Dallas, Denton, Ellis, Johnson, Kaufman, Parker, Rockwall and Tarrant counties.

4 Furthermore, on May 25, 2016, we proposed to approve a redesignation substitute and make a finding of

attainment for both the 1‐hour ozone and the 1997 8‐hour ozone NAAQS for the DFW NAA (81 FR 33161).

5On October 1, 2015, the EPA strengthened the ozone standards to 70 parts per billion or ppb (80 FR 65292,

October 26, 2015). The submittals under evaluation in this TSD do not address the 2015 ozone standard, but will

provide progress toward meeting this newer standard.
3

year, for each of the calendar years 2012 through 2017. The emissions must occur within the

ten‐county nonattainment area. The starting point for calculating the emissions reductions, also

called the “base year,” is 2011 (80 FR 9204, February 20, 2015).

In addition, the RFP plan must include contingency measures, which are additional

controls that would be implemented if the area should fail to make reasonable further progress

(see section 172(c)(9) of the Act). Implementation of these measures would provide additional

emissions reductions of up to three percent of the adjusted base year inventory (or a lesser

percentage that will make up the identified shortfall). The RFP plan must also include MVEBs,

which are the allowable on‐road mobile emissions an area can produce and continue to

demonstrate RFP. EPA’s regulations concerning MVEBs are found at 40 CFR 93.118.

Table 1 below identifies the EIs, rate of progress (ROP)6 and RFP SIPs approved by the

EPA for the DFW area.

Table 1: DFW Emissions Inventories, ROP and RFP SIPs

SIP Revision Federal Register Citation

1‐Hour Ozone Standard; Emissions Inventory 11/8/1994, 59 FR 55586

1‐Hour Ozone Standard; 15% VOC ROP Plan and MVEBs 4/12/2005, 70 FR 18993

1997 8‐Hour Ozone Standard; Emissions Inventory 8/15/2008, 73 FR 47835

1997 8‐Hour Ozone Standard; 15% RFP, MVEBs and Revised EI 10/7/2008, 73 FR 58475

1997 8‐Hour Ozone Standard; RFP and MVEBs 11/12/2014, 79 FR 67068

2008 8‐Hour Ozone Standard; Emissions Inventory 2/20/2015, 80 FR 9204

B. The State’s Submittals and EPA’s Analysis

In this TSD we are reviewing the Texas submittals for consistency with the requirements

of the CAA and EPA’s guidance and regulations.

1. The Base Year Emissions Inventories

The base year EI is the starting point for calculating the reductions necessary to meet

the RFP requirements of the CAA. Section 172 (c)(3) and 182(b)(1) of the CAA require that

nonattainment plan provisions include an inventory of actual NOx and VOC emissions from all

sources in the nonattainment area. On July 10, 2015, the TCEQ submitted to EPA a revised 2011

base year EI as part of the RFP SIP for the 10‐county NAA under the 2008 ozone standard. The

initial 2011 EI was approved early in 2015 (see 80 FR 9204) and since that time, updated models

to estimate mobile emissions and updated emission rates for locomotives and activities

associated with oil and gas production have become available. The submitted revisions to the

2011 EI address area, point, and mobile source emissions in the 10‐county NAA. Those revisions

follow and the two inventories are provided side‐by‐side in Table 2 below:

   

 

6 ROP means for purposes of the 1‐hour ozone NAAQS, the progress reductions required under section 172(c)(2)

and sections 182(b)(1), 182(c)(2)(B), and 182(c)(2)(C) of the CAA. See 40 CFR 51.900(q).
4

Area Source Emissions

Area sources are small scale industrial, commercial and residential sources that

generate emissions, such as gas stations, bakeries, and solvent use (e.g., dry cleaners, auto

paint shops, print shops and house paints). Area sources are numerous and their emissions are

calculated as county‐wide totals rather than as individual facilities. These emissions are typically

estimated by multiplying an established emission 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. An example of actual

activity data is the amount of gasoline sold in an area.

The 2011 area source EI was developed by using EPA‐generated emissions inventories;

TCEQ‐contracted projects to develop emission inventories; TCEQ staff projects to develop

emission inventories; and projecting 2008 emissions inventories by applying growth factors

derived from Eastern Research Group (ERG) study data, the Economy and Consumer Credit

Analytics website (http://www.economy.com/default.asp), and the United States Energy

Information Administration’s (EIA) Annual Energy Outlook publication. In addition, a study

completed by ERG in 2014 further refined emissions factors for oil and gas well mud degassing

and hydraulic pump engines. These improvements revise the prior area source inventory and

are incorporated in the inventories presented in this section. Documentation is provided in

Appendices 3 and 4 of the State’s submittal.

We find the approach and methods of calculating the 2011 area source EI satisfactory

and we recommend approval of the revised 2011 area source EI.

Point Source Emissions

Point sources are individually inventoried and usually located at a fixed, stationary

location. Examples include large industrial facilities, like cement plants and electric power

plants. Point sources are required to submit emissions data to TCEQ annually. The data are

reviewed by the TCEQ for quality assurance purposes and stored in the State of Texas Air

Reporting System (STARS) database. Point source EI data for 2011 was obtained from STARS on

June 5, 2014. The extracted data included reported ozone season daily emissions of NOX and

VOC from each site in the DFW area that submitted a 2011 emissions inventory questionnaire

(EIQ) and reflected revisions made on or before the extract date. There were no changes to

these data from what we approved at 80 FR 9204.

Non‐road Emissions

Non‐road mobile sources generally include industrial and construction equipment; lawn,

garden and agricultural equipment; aircraft/airport equipment; locomotives; and marine

vessels and equipment. A Texas‐specific version of the EPA’s latest NONROAD 2008a model,

called the Texas NONROAD (TexN) model, was used to calculate emissions from the non‐road

mobile sources, with the exception of aircraft/airport, locomotives and oilfield drilling rigs. The

TexN model uses local survey data for categories including diesel construction equipment;

liquid propane gas powered forklifts; transportation refrigeration units; commercial lawn,

garden and agricultural equipment; and recreational marine vessels. The NONROAD model

category emissions included in the proposed version of this SIP revision were developed using
5

version 1.6 of the TexN emissions model. An updated version (1.6.1) of the TexN model became

available on July 30, 2014 and this updated TexN model was used to revise the NONROAD

model category emissions.

Airport emissions were calculated using the Federal Aviation Administration’s Emissions

and Dispersion Modeling System (EDMS). The airport emissions categories used for this RFP

analysis included aircraft (commercial air carriers, air taxis, general aviation, and military),

Auxiliary Power Units, and Ground Support Equipment operations. The 2011 airport emissions

inventory was developed by the North Central Texas Council of Governments (NCTCoG) for the

nine previously designated counties. Wise County airport emissions estimates are from a

statewide county‐specific airport inventory.7 The documentation of procedures used by the

NCTCoG in developing the airport emissions inventories for all but Wise County can be found in

Appendix 9 of the State’s submittal.

The locomotive EI developed from a TCEQ‐commissioned study8 was extracted from the

Texas Air Emissions Repository (TexAER) database. The locomotive emissions inventory includes

line haul and yard emissions activity data from all Class I, II, and III locomotive activity and

emissions by rail segment. This inventory was recently revised to incorporate the use of Texas

Low Emission Diesel (TxLED) and corresponding emission reductions for applicable counties.

Revised documentation of methods and procedures used to develop the 2011 locomotive

emissions inventories can be found in Appendix 7 of the State’s submittal.

Drilling rig diesel engines used in upstream oil and gas exploration activities are included

in the NONROAD model category under “Other Oilfield Equipment.” A survey of oil and gas

exploration and production companies was used to develop improved drilling rig emissions

characterization profiles, building on the work done in 2009. The revisions provide a more

complete and accurate set of drill rig activity. In addition, this study utilized historical drilling

data from the Texas Railroad Commission (RRC) to estimate past emissions, rather than relying

on surrogate based back‐casting from a base year, as was done in 2009. The uncontrolled and

controlled drilling rig emissions characterization profiles from this study were combined with

2011 drilling activity data obtained from the RRC to develop the 2011 inventory. Controlled and

uncontrolled emissions trends were developed by projecting oil and gas production data from

2011 to 2017 and 2018. Please see Appendix 8 of the State’s submittal for more detail on the

development of the drilling rigs EIs.

We find the approach and methods of calculating the 2011 non‐road EI satisfactory and

we recommend approval of the revised 2011 non‐road EI.

On‐road Emissions

On‐road emissions sources include automobiles, trucks and motorcycles ‐ vehicles

commonly driven on roadways. The TCEQ revised the on‐road mobile emissions by using EPA’s

Motor Vehicle Emission Simulator (MOVES) model, MOVES2014 (see 79 FR 60343, October 7,

2014). The initial 2011 EI approved at 80 FR 9204 used EPA’s MOVES2010b model. Additional

updates were made to incorporate the latest activity estimates from the DFW travel demand

 

7 See Appendix 1 of the State’s submittal, sheets 70 and 72‐74.

8 The 2011 inventory report was prepared by ERG.
6

model (TDM) 2011 network. Control strategies implemented prior to 2011 were included in the

input to the emissions inventory development for the 2011 on‐road mobile source base year

emissions inventory. Those controls include: the pre‐1990 Federal Motor Vehicle Control

Program (FMVCP); reformulated gasoline (RFG); the East Texas Regional Low RVP Gasoline

Program, the DFW vehicle inspection and maintenance (I/M) program and on‐road TxLED.

Detailed descriptions of the on‐road data and calculations are provided in Appendices 10 and

11 of the State’s submittal.

We find the approach and methods of calculating the 2011 on‐road EI satisfactory and

we recommend approval of the revised 2011 on‐road EI.

Summary of the Revisions to the 2011 Base Year EI

Table 2 below shows the previously approved 2011 base year EI and the submitted

revisions we are evaluating in this TSD. As described above, there is no change in the point

source EI. The changes to the area source EI are the result of recent refinements to emissions

factors for oil and gas well mud degassing and hydraulic pump engines. The changes to the non‐

road EI are the result of using the updated TexN model; incorporating the use of TxLED in

locomotives; and a recent survey of drilling rig data. The changes to the on‐road EI are the

result of using the updated MOVES2014 model. The changes to the EIs are reasonable and we

recommend approval of the revised 2011 base year EI.

Table 2: Previously Approved (80 FR 9204), and Revised RFP Base Year EIs

2011 Base Year Inventory, reported in tons per day (tpd)

Source Type

NOX VOC

Approved at

80 FR 9204

Submitted

revisions

Approved at

80 FR 9204

Submitted

revisions

Point 39.95 39.95 29.80 29.80

Area 42.64 50.98 292.49 291.31

Non‐road Mobile 120.61 116.95 55.00 54.63

On‐road Mobile 238.87 241.13 98.36 104.12

Total 442.079 449.0110 475.65 479.86

Table 3 shows the revised 2011 base year EI for each source category and identifies the

contributions from Wise County in separate columns. The contributions from Wise County are

distinguished here because, as we describe in the next section of this TSD, when analyzing RFP

for this area, the emissions from Wise County are calculated differently from the rest of the

DFW nonattainment area.

   

 

9 The total NOx approved at 80 FR 9204 is 442.08 tpd. However, 442.07 is the sum of the emissions provided.

10 The total NOx emissions in the TCEQ submittal is 448.98. However, 449.01 is the sum of the emissions provided.
7

Table 3:  Revised 2011 RFP Base Year Inventory (tpd)

Source Type

NOx VOC

9 Counties Wise

County

10‐County

Total

9 Counties Wise

County

10‐County

Total

Point 31.34 8.61 39.95 27.66 2.14 29.80

Area 37.69 13.29 50.98 262.36 28.95 291.31

Non‐road

Mobile

110.26 6.69 116.95 53.38 1.25 54.63

On‐road

Mobile

235.23 5.90 241.13 102.39 1.73 104.12

Total 414.52 34.49 449.01 445.79 34.07 479.86

2. Calculating RFP

In calculating RFP for Moderate and above areas, CAA section 182(b)(1) under subpart 2

requires a 15 percent reduction in VOC emissions from the baseline anthropogenic emissions

within 6 years after the effective date of designations. With respect to RFP requirements, we

interpret the 15 percent VOC emission reduction requirement in CAA section 182(b)(1) such

that an area that has already met the 15 percent requirement for VOC under either the 1‐hour

ozone NAAQS or the 1997 ozone NAAQS (for the first 6 years after the RFP baseline year for the

prior ozone NAAQS) would not have to fulfill that requirement again. Instead, such areas would

be treated like areas covered under CAA section 172(c)(2) if they are classified as Moderate for

the 2008 ozone NAAQS. For purposes of the 2008 ozone NAAQS, the EPA has interpreted CAA

section 172(c)(2) to require such Moderate areas to obtain 15 percent ozone precursor

emission reductions over the first 6 years after the baseline year for the 2008 ozone NAAQS. In

addition, NOx emission reductions could be substituted for VOC reductions. See 80 FR 12264,

12271 and 40 CFR 51.1110.11

The DFW 10‐county NAA includes nine counties that have already met the 15% emission

reduction requirement for VOC under the 1‐hour ozone NAAQS (Collin, Dallas, Denton and

Tarrant, see 70 FR 18993) and the 1997 ozone NAAQS (Ellis, Johnson, Kaufman, Parker and

Rockwall, see 73 FR 58475). Wise County however, must meet the 15% VOC emission reduction

requirement and therefore the emissions reductions are calculated separately from the other

nine counties listed here.

Section 182 of the CAA and 40 CFR 51.1110 require that the 15% emissions reduction is

calculated from the base year EI to provide the emissions “targets” or milestones.

The tables below show the steps to calculate the RFP targets for NOx and VOC

reductions for 2017 for the nine counties (Table 4) and for Wise County (Table 5).

 

11 See also our December 1993 NOx Substitution Guidance at

http://www3.epa.gov/ttn/caaa/t1/memoranda/noxsubst.pdf.
8

Table 4: Calculation of NOx and VOC Reductions for the Nine Counties through 2017(tpd)

Description NOx VOC  

a. 2011 Emissions Inventory (from Table 3 above) 414.52 445.79

b1. 2011 On‐road Adjusted Base Year EI12 729.90 329.84

b2. 2017 On‐road Adjusted Base Year EI 727.03 334.29

c. Non‐creditable reductions, 2011‐2017 (b1‐b2) 2.87  ‐4.45

d. 2017 Adjusted Base Year EI (row a minus row c) 411.65 450.24

e. Percent of NOX and VOC to meet 15% reduction 10.0% 5.0%

f. 15% NOX and VOC reduction, 2011‐2017

(row d multiplied by row e)

(411.65 x 0.1 = 41.17)13 and (450.24 x 0.05 = 22.51)

41.17 22.51

g. 2017 Target Level of Emissions (d‐f) 370.48 427.73

Table 5: Calculation of NOx and VOC Reductions for Wise County through 2017(tpd)

Description NOx VOC  

a. 2011 Emissions Inventory 34.49 34.07

b1. 2011 On‐road Adjusted Base Year EI 16.40 4.41

b2. 2017 On‐road Adjusted Base Year EI 16.19 4.49

c. Non‐creditable reductions, 2011‐2017 (b1‐b2) 0.21  ‐0.08

d. 2017 Adjusted Base Year EI (row a minus row c) 34.28 34.15

e. Percent of NOX and VOC to meet 15% reduction N/A 15.0%

f. 15% VOC reduction, through 2017 (row d x row e)

(34.15 x 0.15 = 5.12)

N/A 5.12

g. 2017 Target Level of Emissions (d‐f) 34.28 29.03

3. Control Measures

Now that we’ve calculated the emissions targets, let’s determine whether the area has

ample emission reductions (in the form of control measures) to reach those targets. The control

measures used to achieve the necessary emission reductions to meet the RFP requirements are

discussed in Chapter 4 of the Texas submittal and listed below in Tables 6 and 7. The measures

used for RFP do not include all emissions reduction programs for the DFW area, but just those

necessary to meet the RFP requirements for 2017 and 2018. The State has therefore chosen to

use State and Federal non‐road and on‐road mobile source measures. The State rules relied on

in this plan were approved in prior actions, as identified here. The approval dates and citations

 

12 The “adjusted” emissions in Tables 4 and 5 are uncontrolled or what we would expect to see if the on‐road fleet

did not implement the low Reid Vapor Pressure (RVP) gasoline and the pre‐1990 emission controls. Such controls

are not creditable under section 182(b)(1)(D) of the CAA, but are no longer required to be calculated for exclusion

in RFP analyses because the Administrator has determined that due to the passage of time the effect of these

exclusions would be de minimis (40 CFR 51.1110). However, since the pre‐1990 fleet turnover corrections are

cumulative in the MOVES model, the State continues to show these non‐creditable reductions to achieve a more

accurate accounting.

13 10% is equal to 0.1. Thus 411.65 x 0.1 = 41.165 and we round up to 41.17.
9

for the federal rules listed below are available at www.epa.gov/otaq/standards/index.htm.

Non‐road emissions reductions were a result of implementing federal measures such as the

standards for non‐road spark‐ignition (SI) engines, heavy duty non‐road engines, Tier 2 and 3

non‐road diesel engines, and Tier 1 and 2 locomotive NOx standards. Reductions in on‐road

emissions came from the I/M program (see 66 FR 57261, 11/14/2001), the FMVCP, the use of

RFG, and the Tier 3 vehicle emission and fuel standards program, which will reduce the content

of sulfur in gasoline beginning in 2017.14 We find that the projected emission reductions are

reasonable and acceptable.

Table 6. NOx and VOC Control Measures and Expected Emission Reductions (tpd) for the Nine

Counties, 2011‐2018

Control Strategy Description 2011‐2017

NOx

2011‐2017

VOC

2011‐2018

NOx

2011‐2018

VOC

FMVCP 637.38 283.41 678.58 298.78

I/M program 12.26 10.57 10.87 10.06

RFG/East Texas Regional RVP

Gasoline Program

52.63 21.27 48.71 20.10

On‐road TxLED15 3.77 0.00 3.38 0.00

Tier 1 and 2 locomotive NOx

standards

0.10 0.20 0.20 0.30

Small non‐road SI engines (Phase 1)  ‐3.4416 32.27 ‐3.50 32.81

Heavy duty non‐road engines 25.39 9.43 26.08 9.70

Tiers 2 and 3 non‐road diesel engines 33.56 6.54 35.03 6.77

Small non‐road SI engines (Phase 2) 2.40 31.24 2.44 31.77

Large non‐road SI & recreational

marine

32.71 13.84 34.14 14.65

Non‐road TxLED (footnote 14) 2.33 0.00 2.16 0.00

Non‐road RFG  ‐0.47 1.37 ‐0.54 1.59

Tier 4 non‐road diesel engines 15.55 0.85 18.02 0.95

Small SI (Phase 3) 2.02 13.54 2.13 14.26

2017 Low Sulfur Gasoline Standard 14.60 2.72 13.97 2.68

Drilling rigs17 8.71 1.60 6.62 1.22

Total Reductions Projected   839.50 428.85 878.29 445.64

 

14 The RFG program in the DFW area is implemented only in Collin, Dallas, Denton, and Tarrant counties.

15 The TxLED fuel rules apply to highway (on‐road) and non‐road vehicles and were approved into the Texas SIP on

November 14, 2001 (66 FR 57196). Subsequent revisions were approved April 6, 2005 (70 FR 17321), October 6,

2005 (70 FR 58325), October 24, 2008 (73 FR 63378), and May 6, 2013 (78 FR 26255).

16 The increase in emissions is due to engine modifications to meet the standards for VOC and carbon monoxide.

17 The TCEQ did not include emission reductions from drilling rigs in the RFP calculations submitted on July 10,

2015. Such reductions however, were included in the July 10, 2015 submittal (see Appendix 1, sheet 23) and are

essential to demonstrate RFP in Wise County. The technical supplement submitted by the TCEQ on April 22, 2016

provides a recalculation of RFP with emission reductions from the drilling rigs. Such reductions are the result of

Federal diesel engine emission standards and non‐road TxLED. The technical supplement is posted in our docket.
10

Table 7. NOx and VOC Control Measures and Expected Emission Reductions (tpd) for Wise

County, 2011‐2018

Control Strategy Description 2011‐2017

NOx

2011‐2017

VOC

2011‐2018

NOx

2011‐2018

VOC

FMVCP 14.01 3.63 14.91 3.84

East Texas Regional Low RVP

Gasoline Program  

0.77 0.19 0.70 0.19

On‐road TxLED 0.11 0.00 0.10 0.00

Tier 1 and 2 locomotive NOx

standards

0.01 0.02 0.02 0.03

Small non‐road SI engines (phase 1)  ‐0.03 0.21 ‐0.03 0.22

Heavy duty non‐road engines 1.22 0.49 1.23 0.50

Tiers 2 and 3 non‐road diesel engines 1.48 0.16 1.51 0.17

Small non‐road SI engines (phase 2) 0.02 0.21 0.02 0.21

Large non‐road SI & recreational

marine

0.20 0.28 0.21 0.30

Non‐road TxLED 0.07 0.00 0.06 0.00

Tier 4 non‐road diesel engines 0.75 0.03 0.86 0.04

Small SI (Phase 3) 0.02 0.21 0.02 0.23

2017 Low Sulfur Gasoline Standard 0.31 0.05 0.30 0.05

Drilling rigs (see footnote 17) 1.35 0.25 1.04 0.19

Total Reductions Projected   20.29 5.73 20.95 5.97

4. Demonstration of the RFP

In order to show that the reductions associated with the control measures are adequate

to meet the percent reduction requirements, the 2011 base year emissions are projected to

2017 and 2018. The total of VOC and NOx emissions in the projected inventories must be equal

or less than the target inventories (listed at line g in Tables 4 and 5, above). Texas developed

the projected inventories for 2017 and 2018 by first estimating growth and then calculating the

reductions from the control measures listed in Tables 6 and 7 above. The growth factors for

point and area sources were established upon a base year of 2005, which was the most recent

EI available at the time.18 Various demographic and economic data were used to develop the

growth factors, including: energy projections from the EIA’s Annual Energy Outlook, economy

forecasts from Economy.com, and Texas‐specific population projections. The MOVES2014

model was used to project growth of on‐road mobile sources and the TexN model to project

growth of non‐road mobile sources. We find the approach and methods of calculating the

future inventories acceptable.

Tables 8 and 9 below summarize the emissions reductions through 2017 and 2018 and

demonstrate how the area will meet the RFP targets for those years.

 

18 The work to update projection factors for point and area sources was completed in August 2010 by ERG. See

Appendix 3 of the State’s submittal.
11

Table 8. Summary of RFP Demonstration for DFW through 2017 (tpd)

Description NOx VOC NOx VOC

9 Counties Wise County

a. 2017 Target (from Tables 4 and 5 above) 370.48 427.73 34.28 29.03

b. 2017 Uncontrolled Emissions19 1139.93 830.38 49.33 34.68

c. Projected Emission Reductions through 2017 839.50 428.85 20.29 5.73

d. Projected Emissions after Reductions (b‐c) 300.43 401.53 29.04 28.95

2017 RFP Targets 370.48 427.73 34.28 29.03

RFP Met? yes yes yes yes

Surplus or (shortfall) 70.05 26.20 5.24 0.08

As shown in Table 8 above, the projected emissions of NOx and VOC for all counties in

the DFW 10‐county NAA are sufficient to meet the RFP targets for 2017.  

Chapter 3 and Appendix 1 of the State’s July 2015 submittal and the April 2016

submittal provide the methodology and calculations used to determine the target emission

levels and demonstrate RFP. We find that the State’s RFP demonstration for the DFW area is in

accordance with EPA guidelines (see 80 FR 12264) and recommend approval of such.

5. Contingency Provisions

For ozone nonattainment areas classified as moderate or above, states must include in

their submittal contingency measures to be implemented if the area fails to make reasonable

further progress (CAA section 172(c)(9)). The contingency measures should, at a minimum,

ensure that an appropriate level of emissions reductions continue to be made if attainment or

RFP are not achieved. The EPA interprets the Act to require states with moderate and above

ozone nonattainment areas to include sufficient contingency measures so that, upon

implementation of such measures, additional reductions of up to 3 percent of the emissions in

the adjusted base year EI would be achieved in the year following the year in which the failure

has been identified. The EPA continues to allow the use of federal measures providing ongoing

reductions into the future to be used to meet contingency measure requirements for the 2008

ozone NAAQS, consistent with the EPA’s longstanding policy (see 80 FR 12264). Contingency

measures could include federal measures and local measures already scheduled for

implementation, as long as their emission reductions are beyond those needed for attainment

or to meet RFP. The CAA does not preclude a state from implementing such measures before

they are triggered. For more information on contingency measures see the April 16, 1992

General Preamble (57 FR 13498, 13511) and the SRR (80 FR 12264).

Texas provided emissions reductions in excess of those needed for RFP as contingency

measures (see Chapter 4, pages 15‐17 of the State’s submittal). Tables 9 and 10 below

summarize the emissions reductions used for contingency measures.

   

 

19 See Appendix 1 of the State’s submittal, sheets 38, 39, and 68.
12

Table 9. Demonstration for 2018 for Nine Counties, Contingency Measures (tpd)

Description NOx VOC

A. 2017 Adjusted Base Year EI (Table 4, line d) 411.65 450.24

B. Percent of NOx and VOC to meet 3% contingency 2% 1%

C. Required reduction to provide contingency (A x B) 8.23 4.50

D. Reduction to meet RFP in 2017 (Table 4, line g) 41.17 22.51

E. 2018 FMVCP non‐creditable reductions20 0.58 0.23

F. 2018 Target Level of Emissions (line A‐C‐D‐E) 361.67 423.00

Excess reductions to meet contingency requirement    

G. 2018 Uncontrolled Emissions21 1157.47 833.75

H. Total Reductions Projected through 2018 (from Table 6 above) 878.29 445.64

J. Projected emissions after reductions (line G minus line H) 279.18 388.11

Add line C22 8.23 4.50

K. Projected emissions, accounting for contingency measures 287.41 392.61

Total surplus or shortfall    

Line K is less than line F. Subtract line K from line F for surplus 74.26 30.39

Is the contingency measure requirement met? Yes Yes

Table 10. Demonstration for 2018 for Wise County, Contingency Measures (tpd)

Description NOx VOC

A. 2017 Adjusted Base Year EI (Table 5, line d) 34.28 34.15

B. Percent of NOx and VOC to meet 3% contingency 3%  ‐‐ 

C. Required reduction to provide contingency (A x B) 1.03  ‐‐ 

D. Reduction to meet RFP in 2017 (Table 5, line f)  ‐0‐  5.12

E. 2018 FMVCP non‐creditable reductions23  ‐0‐  ‐0‐ 

F. 2018 Target Level of Emissions (line A‐C‐D‐E) 33.25 29.03

Excess reductions to meet contingency requirement    

G. 2018 Uncontrolled Emissions24 46.24 29.71

H. Total Reductions Projected through 2018 (from Table 7 above) 20.95 5.97

J. Projected emissions after reductions (line G minus line H) 25.29 23.74

Add line C (see footnote 21) 1.03  ‐0‐ 

K. Projected emissions, accounting for contingency measures 26.32 23.74

Total surplus or shortfall    

Line K is less than line F. Subtract line K from line F for surplus 6.93 5.29

Is the contingency measure requirement met? Yes  ‐‐ 

 

20 See Appendix 1 of the State submittals, sheets 15 and 17.

21 See Appendix 1 of the State submittals, sheets 7, 40 and 69.

22 The NOx and VOC emission reductions used to meet the contingency requirement in line B must be removed

from the total reductions projected through 2018 to determine whether they are in excess of (or surplus to) the

emissions reductions needed to meet the 2018 target level of emissions.

23 See Appendix 1 of the State submittals, sheets 15 and 18.

24 See Appendix 1 of the State submittals, sheets 8, 41 and 69.
13

As shown in Tables 9 and 10 above, the NOx reductions projected through 2018 are

sufficient to meet the requirement for contingency measures. Note that VOC reductions for

Wise County are not necessary for this contingency demonstration, but those projected

through 2018 (5.97 tpd) are greater than what would be needed to meet such requirement

(34.15 x 0.03 = 1.02). Therefore, we recommend approval of the RFP contingency measures.

6. Motor Vehicle Emissions Budget

The 2008 ozone RFP plan must include MVEBs for transportation conformity purposes.

The MVEB is the mechanism to determine if the future transportation plans conform to the SIP.

Conformity to a SIP means that transportation activities will not produce new air quality

violations, worsen existing violations, delay RFP milestones, or delay timely attainment of the

NAAQS. A MVEB is the maximum amount of emissions allowed in the SIP for on‐road motor

vehicles The MVEB establishes an emissions ceiling for the regional transportation network. The

DFW RFP SIP contains VOC and NOx MVEBs for the RFP milestone year 2017 and these are

provided in Table 11 below. On‐road emissions must be shown in future transportation plans to

be less than the MVEBs for 2017 and subsequent years.

We found the 2017 MVEBs (also termed transportation conformity budgets) adequate,

and on August 25, 2015, the availability of these budgets was posted on our website for the

purpose of soliciting public comments. The comment period closed on September 24, 2015, and

we received no comments. On January 11, 2016, we published the Notice of Adequacy

Determination for these RFP MVEBs (81 FR 1184).25 Once determined adequate, these RFP

budgets must be used in future DFW transportation conformity determinations. The adequacy

determination represents a preliminary finding by EPA of the acceptability of the MVEB. Today

we are finding the MVEBs are fully consistent with RFP, and the RFP plan is fully approvable, as

it sets the allowable on‐road mobile emissions the DFW area can produce and continue to

demonstrate RFP.

Table 11. RFP Motor Vehicle Emissions Budgets for DFW (tpd)

Year NOx VOC

2017 148.36 77.18

D. Summary and Recommendations

The TCEQ used acceptable techniques to revise the base year EI and calculate the 2017

target EIs, the emissions reductions for the milestone years 2017 and 2018, and the

contingency provisions. The surplus in NOx and VOC emissions for the period from 2011 ‐ 2017

are sufficient to demonstrate RFP. In addition, the surplus in NOx and VOC emissions through

2018 are sufficient to meet the requirement for contingency. Therefore we recommend

approval of the revisions to the 2011 base year EI, the DFW RFP Plan for the moderate ozone

nonattainment area under the 2008 ozone standard, the associated contingency measures for

2018, and the MVEBs adopted by the TCEQ for 2017.

 

25 The notice of adequacy is posted in the docket for this rulemaking.