COMMENTS BY THE TEXAS COMMISSION ON ENVIRONMENTAL QUALITY 

REGARDING THE NOTICE OF DATA AVAILABILITY SUPPORTING FEDERAL

IMPLEMENTATION PLANS TO REDUCE INTERSTATE TRANSPORT OF FINE 

PARTICULATE MATTER AND OZONE: REVISIONS TO EMISSION INVENTORIES

EPA DOCKET ID NO. EPA-HQ-OAR-2009-0491

I. Summary of Proposed Action

On October 27, 2010, the United States Environmental Protection Agency (EPA) published in 

the Federal Register a Notice of Data Availability (NODA) for emissions inventories (75 FR 

66055) supporting the previously proposed Transport Rule (75 FR 45210). The NODA included 

updated emissions inventory data for 2005, 2012, and 2014 for several stationary and mobile 

source inventory components. Though the EPA noted that these data and revisions could impact 

the final Transport Rule, it specifies that such impacts have not yet been quantified by the EPA, 

and it requests comment only on the new data provided in the NODA. 

II. Comments

General Comment.

The EPA’s request for comment on its proposed use of the revised data identified 

in NODA to make changes to the final Transport Rule is unreasonable and does 

not provide adequate notice to the public of the potential changes to the final 

Transport Rule.

The NODA does not provide adequate information or time for the public to comment on the 

potential changes to the final Transport Rule. The EPA’s failure to identify criteria used to 

determine which new data were appropriate to include in the NODA compounds these errors. 

The EPA has failed to explain why these particular data changes were critical for inclusion in 

future final Transport Rule modeling, when commenters have provided comments regarding 

other missing or incorrect data. Additionally, as discussed further in these comments, mere 

provision of data without an explanation of the potential changes that could be made by the EPA 

in the final Transport Rule is inadequate for the public to assess and comment on the potential 

future rule changes or the implications of using this revised data. The EPA has stated that it 

intends to rely on the new data, and potentially other new data, for inclusion in computer 

modeling to determine applicability for the final Transport Rule, but the public cannot 

reasonably provide meaningful comments without some understanding of the final modeling 

results. Placing the burden on the public to comment on changes to the final Transport Rule 

that will result from complex computer modeling not yet completed nor available to the public 

does not allow the public to ascertain whether they have a specific interest at stake. 
COMMENTS OF TEXAS COMMISSION ON ENVIRONMENTAL QUALITY

DOCKET NO. EPA-HQ-OAR-2009-0491

PAGE 2 OF 5

If the EPA continues to revise emissions inventory data and places additional 

information in the docket to support changes to the final rulemaking, then the 

EPA should make that information available for public comment. The EPA should 

also reopen the comment period for the complete rulemaking package to allow 

for adequate opportunity for the public to evaluate the potential impact of the 

rule and provide meaningful public comment. 

If the EPA does continue to update information, including emission inventory data, that is used 

to support the final rulemaking, the Texas Commission on Environmental Quality (TCEQ) 

requests that any such information be made available for public comment. Furthermore, the 

TCEQ requests that the complete rulemaking package be reopened for comment and that the 

EPA provide adequate time for all the technical information and any potential changes to the 

rule to be evaluated. Absent such an opportunity to comment on the complete proposed rule and 

any substantive changes that the EPA may make using new information, the public is unable to 

reasonably provide meaningful comments or to evaluate the potential impact of the rule.

Request for comment on revised 2012 and 2014 projected non-electric generating unit (EGU) 

emissions sector (75 FR 66056).

The EPA’s request for comment on the revised non-EGU emissions inventories is 

unreasonable given the short comment period that the EPA is allowing for review 

of such voluminous data.

The 2014 non-EGU point source emissions inventory data for Texas provided by the EPA with 

this NODA exceeds 132,000 rows of data. It is unreasonable of the EPA to expect states to 

provide meaningful comment on the accuracy of the EPA’s future projected emissions inventory 

on this amount of data with only a 30-day comment period. 

While the EPA has provided significant amounts of emissions data, the information and context 

provided with the NODA are not adequate for states and other parties to appropriately comment 

on the emission data. The EPA has not provided sufficiently detailed explanations on how the 

emissions inventory data were adjusted and in some cases has only provided emissions data 

with no explanation of how the emissions were adjusted.

As suggested in the TCEQ’s original comments on the Transport Rule, submitted on October 1, 

2010, the EPA should work with states outside of the rulemaking comment period to develop a 

more accurate future-projected emissions inventory for the non-EGU sector. The EPA’s rush to 

finalize the future non-EGU emissions inventory within the limited time period of the Transport 

Rule comment period will lead to an inaccurate emissions inventory and fundamentally bias any 

decisions the EPA might make based on those data.

Proposal to include revised emissions inventory in the final Transport Rule (75 FR 66057).

If it is the EPA’s intent to use the revised emissions inventory as a justification for 

expanding the scope of the proposed Transport Rule, the TCEQ strongly objects to 

the EPA attempting such a change in scope of the proposed rule without proper

notice.

The EPA indicates that it is not limited in the manner and scope in which the revised emissions 

inventory data may be used to change the final rulemaking. The NODA also indicates that the 
COMMENTS OF TEXAS COMMISSION ON ENVIRONMENTAL QUALITY

DOCKET NO. EPA-HQ-OAR-2009-0491

PAGE 3 OF 5

EPA may revise its assessment of which areas may have air quality concerns and which states 

are contributing to downwind areas, without specifying which states or areas may be so 

impacted. If the revised data indicates that the scope of the Transport Rule should be narrowed, 

such a change would be within the scope and notice of the original proposed rulemaking. 

However, if the EPA expands the Transport Rule based on this revised emissions inventory to 

affect new parties that were not subject to the rule as proposed on August 2, 2010, these parties 

would not have been provided adequate notice. That the EPA proposes inclusion of new data 

that may fundamentally alter the applicability of the original Transport Rule proposal but then 

allows comment only on the new data (and without full indication of the manner in which the 

data may be used) makes clear that the NODA published in the October 27, 2010, issue of the 

Federal Register does not provide adequate notice for potential expansion of the Transport Rule 

to other parties. 

Request for comment on emissions reductions resulting from the National Emission Standards 

for Hazardous Air Pollutants (NESHAP) for Reciprocating Internal Combustion Engines (75 FR 

66056).

The EPA should not be ignoring EPA-approved enforceable state control 

measures that are included in the state implementation plan (SIP) while 

apparently claiming unenforceable ancillary nitrogen oxides (NOX) reductions 

from federal measures as creditable for the Transport Rule.

The technical support document spreadsheet regarding reductions resulting from federal 

measures such as the National Emission Standards for Hazardous Air Pollutants (NESHAP) for 

reciprocating internal combustion engines (TR_EI_NODA_relevant_CoSTpackets_and_ 

inventories.xls) that the EPA has posted on its ftp site for this NODA appears to indicate that the 

EPA is crediting NOX reductions from the NESHAP regulation in 40 Code of Federal 

Regulations Part 63, Subpart ZZZZ as part of the Transport Rule modeling. The TCEQ does not 

dispute that the installation of nonselective catalytic reduction (NSCR) systems on stationary 

rich-burn engines to meet the hazardous air pollutant (HAP) limits in the final rule will also 

result in NOX reductions. As noted by the EPA in the document provided with the NODA and

the Federal Register publication (75 FR 51578) for the final rule of Subpart ZZZZ, these NOX 

reductions are co-benefits of the control technology potentially installed to meet the enforceable 

limits in Subpart ZZZZ and are not enforceable under federal rule. However, in the EPA’s 

technical support document for the Transport Rule emissions inventories, the EPA indicates 

that for local SIP controls to be included in the final rule: “1) the SIPs must be approved and 

made available, and 2) the control measures and technologies are provided in such a way that 

they can be applied to our inventories (e.g., control efficiencies or emission reductions matched 

to specific NEI facilities, units, and/or source category codes (SCCs)).” The TCEQ objects to the 

EPA holding itself to far less stringent requirements than states are being expected to meet for 

the EPA to acknowledge local controls after 2005 for purposes of the Transport Rule.

As discussed in the comments submitted by the TCEQ during the original Transport Rule 

comment period, the TCEQ has implemented control strategies that have resulted in significant 

NOX reductions in Texas. Among these TCEQ rules are enforceable NOX emission 

specifications for stationary reciprocating internal combustion engines that went into effect after 

2005 that are approved by the EPA (December 3, 2008, 75 FR 73562) as part of the Texas SIP 

and were also included in the Texas Transport SIP, which was acknowledged as received by the 

EPA on May 6, 2008, but on which the EPA has not yet taken action. The following is a 
COMMENTS OF TEXAS COMMISSION ON ENVIRONMENTAL QUALITY

DOCKET NO. EPA-HQ-OAR-2009-0491

PAGE 4 OF 5

summary of the gas-fired stationary reciprocating internal combustion NOX rules that the EPA 

approved in 2008.

• For the Dallas-Fort Worth (DFW) Eight-Hour Ozone Nonattainment Area (Collin, Dallas, 

Denton, Ellis, Johnson, Kaufman, Parker, Rockwall, and Tarrant Counties), the NOX 

emission specifications for stationary gas-fired engines rated 50 horsepower (hp) and larger 

are between 0.50 and 0.70 grams per horsepower-hour (g/hp-hr), depending on the fuel 

type and burn type (rich or lean). These emission standards apply to existing and new 

engines both major and minor sources in the DFW Eight-Hour Ozone Nonattainment Area 

and are found in 30 TAC Chapter 117, §117.410(b)(4) and §117.2110(a)(1).

• For the East Texas Combustion Rule counties (Anderson, Brazos, Burleson, Camp, Cass, 

Cherokee, Franklin, Freestone, Gregg, Grimes, Harrison, Henderson, Hill, Hopkins, Hunt, 

Lee, Leon, Limestone, Madison, Marion, Morris, Nacogdoches, Navarro, Panola, Rains, 

Robertson, Rusk, Shelby, Smith, Titus, Upshur, Van Zandt, and Wood Counties), the NOX 

emission specifications for stationary rich-burn gas-fired engines are 0.50 g/hp-hr for richburn engines equal to or greater than 500 hp (0.60 g/hp-hr for landfill gas-fired engines) 

and 1.0 g/hp-hr for rich-burn engines between 240 hp and 500 hp. These emission 

standards apply to existing and new engines at both major and minor sources in these 33 

East Texas counties and are found in 30 TAC Chapter 117, §117.3310(a)(1).

Request for comment on revised oil and gas emissions inventory for Texas and Oklahoma (75 

FR 66056).

The EPA’s projected oil and gas drilling rig emissions for Texas are not 

consistent with the TCEQ’s projected emissions estimates; however, the EPA has 

not provided sufficient information for TCEQ to adequately comment on the 

accuracy of the EPA’s projected emissions for 2012 and 2014.

The EPA’s projected emissions data for drilling rigs in Texas do not agree with the projected 

emissions data for 2012 and 2014 from the 2009 study, Drilling Rig Emission Inventory for the 

State of Texas, conducted by Eastern Research Group, Inc. (ERG), which is the basis of the 

original 2005 emissions data that the TCEQ provided to the EPA. The EPA should provide a 

clear explanation of, and the basis for, the assumptions that were used to grow or control the 

emissions data that the TCEQ provided on oil and gas drilling rig emissions. Without such 

explanation in the public docket available for public comment, the TCEQ cannot properly 

evaluate and comment on the discrepancy between the EPA’s projected emissions data and the 

results of the ERG study. The EPA should either explain the methodology used to project the 

drilling rig emissions data to 2012 and 2014 or use the projected emissions data from the ERG 

study that the TCEQ used to provide the original emissions data. The 2009 study report is 

available on the TCEQ’s Web site at: 

http://www.tceq.state.tx.us/implementation/air/airmod/project/pj_report_ei.html. 
COMMENTS OF TEXAS COMMISSION ON ENVIRONMENTAL QUALITY

DOCKET NO. EPA-HQ-OAR-2009-0491

PAGE 5 OF 5

Request for comment on the EPA’s proposal to use the latest public release of the Motor Vehicle 

Emissions Simulator (MOVES) to estimate on-road mobile emissions data (75 FR 66057). 

The TCEQ requests that the EPA specify by name which “latest public release” of 

MOVES it intends to use in developing the 2005, 2012, and 2014 on-road 

inventories and ensure that this version has been made available to the public for 

comment. 

While the TCEQ continues to object to the EPA’s revisions of emissions inventories that may 

fundamentally alter the scope and applicability of the Transport Rule without also re-opening 

the Transport Rule comment period, the TCEQ requests that if an updated version of MOVES is 

to be used by the EPA for interstate transport modeling efforts, this version should be clearly 

identified by name and have been previously made available to the public. Because MOVES is in 

development and newer versions may become available, the EPA should identify which version 

will be used and for what purpose. By stating only that the “latest public release” of MOVES may 

be used, the EPA leaves open the possibility of releasing a newer version after the close of this 

NODA comment period and using that version for the final Transport Rule. Without knowing 

specifically which version of MOVES the EPA intends to use, the TCEQ has no basis on which to 

comment on the appropriateness of using a yet-to-be decided version and cannot predict how 

mobile emissions estimates might be altered.