OMB June 29 Comments on Transport Rule

A. Pathway from 2010 to 2012 

- Generally further discussion is needed in the preamble explaining how sources will meet the 

2012 caps given the 2010 known emissions – EPA has generated additional analysis on this point 

and it be helpful to explain this in the preamble. 

Response: Please see attached redline to section VII.C.2 of preamble for the new language that 

EPA proposes to add in regards to this issue. 

B. Texas FIP Clarification for the PM NAAQS 

- Please explain the following on pages 29 and 20 of the redline – if Texas doesn’t contribute to 

nonattainment or interference with maintenance in another state for the 24-hour PM2.5 NAAQS, 

why is EPA making a statement that the FIP for Texas satisfies its contribution to nonattainment 

or interference with maintenance of the 2006 24-hr PM 2.5 in another state? : 

With respect to the 24-hour PM2.5 NAAQS, the analysis EPA 

conducted for the proposal did not identify Texas as a state 

that significantly contributes to nonattainment or interferes 

with maintenance of 24-hour PM2.5 in another state. However, the 

analysis conducted for the final rule shows that emissions from 

Texas do significantly contribute to nonattainment of the 24-

hour PM2.5 NAAQS in another state. EPA is not issuing a FIP for 

Texas with respect to the 24-hour PM2.5 NAAQS in this rule. 

 However, EPA believes that the FIP for Texas with respect to 

the 1997 annual PM2.5 NAAQS also addresses the emissions in Texas 

that significantly contribute to nonattainment and interference 

with maintenance of the 2006 24-hour PM2.5 NAAQS in another 

state. 

Response: As explained in this section of the preamble, the Transport Rule’s air quality analysis does show 

that Texas significantly contributes to nonattainment or interferes with maintenance for the 24-hour PM2.5 

NAAQS. However, EPA is not issuing a FIP for Texas with respect to the 24-hour PM2.5 NAAQS 

because EPA requested comment on Texas inclusion in the proposal only with respect to the annual 

PM2.5 NAAQS. However, we continue to believe that inclusion of Texas in the Transport Rule annual 

NOx and annual SO2 programs will address their significant contribution with respect to the 2006 PM2.5 

NAAQS. Also, while we have proposed to disapprove the 2006 PM2.5 SIP for Texas, final action has not 

yet been taken on that proposal and thus we do not have an outstanding FIP obligation like we do with 

respect to the 1997 PM2.5 NAAQS. For these reasons, we are not including a FIP for Texas with respect 

to the 2006 PM2.5 NAAQS even though our analysis shows it does significantly contribute to 

nonattainment or interfere with maintenance of the 24-hour PM2.5 NAAQS in another state.
C. Cost-Benefit Table Adjustment 

- Page 35 and 435 – Reorganize and label the CBA table for clarity as follows (Table III-4, and 

Table VIII.C-3) – further, shouldn’t the net benefits be 1 billion lower based on rounding 

conventions?: 

Summary of Annual Benefits, Costs, and Net Benefits of the 

Final Transport Rule in 2014a

Description Transport Rule Remedy (Billions of 2007$) 

3% discount rate 7% discount rate 

Total social costs $0.81 $0.81 

Total monetized 

benefitsb

$120 to $280 $110 to $250 

Net benefits 

(benefits minus 

costs) 

$120 to $280 $100 to $250 

Response: EPA rounds benefits and net benefits to two significant figures, consistent with 

review from the National Academies of Science. Given the magnitude of the benefits as 

compared to the costs of this rule, the net benefits, when rounded based on these 

scientifically-reviewed conventions, remain the same as the gross benefits in these tables. 

EPA appreciates the improvements offered by the proposed restructuring of the tables and 

has implemented this recommended change – please see the attached “ Benefit Tables_Table 

Table III-4 and VIII.C-3” showing redline revisions to these tables for the preamble. 

D. SNCR Clarifications

- Page 77 –Footnote 77 is referenced in support of the supposition that some plant owners might 

choose to achieve NOx reductions using options other than LNB/OFA, such as a selective noncatalytic reduction (SNCR) system. Please note that the SNCR NOx reduction potential is 

significantly below the LNB/OFA level for pulverized-coal boilers, as shown in EPA’s IPM 

documents. Therefore, an SNCR system may not be a substitute for LNB/OFA if such units are 

intended to reduce NOx to the levels expected from LNB/OFA. In addition, the document in the 

above footnote contains information on only the time it takes to install the SNCR equipment on 

the boiler. For total installation timing, EPA should be referencing another document that 

contains such information. One such document, “Typical Installation Timelines for NOx 
Emissions Control Technologies on Industrial Boilers,” by ICAC, December 4, 2006, show a 

total installation time of close to one year, which does not include any planning or preengineering by the owner. Furthermore, the installation time may be longer for a larger utility 

boiler. Therefore, considering the 6-month time the affected sources have for compliance, 

SNCR may not be a viable option. It may be helpful for EPA to make note of that and point to a 

sensitivity analysis of this assumption. 

Response: EPA’s suggestion in this section of the preamble that individual unit owners may 

consider SNCR does not convey that universal replacement in a state of LNB/OFA by SNCR 

would deliver adequate emission reductions for the state to meet its emission reduction 

requirements under the Transport Rule. Rather, this reference appears in the context of the 

section describing the flexibilities that individual unit owners have under the Transport Rule 

to consider multiple NOX emission reduction strategies in response to the economic signal 

created by the programs. There is no specific unit-level requirement for NOX rate control 

under the Transport Rule programs. Regarding the sensitivity of NOX reductions to the 

timing of control installation (whether LNB or SNCR), table VII.C.2-2 in the preamble 

explains why the Transport Rule 2012 budgets are robust to the precise timing of the 

installation of these controls, even as EPA believes that there is adequate time to compete 

these retrofits by the beginning of the program. 

E. Capital Investments for CAIR Clarifications 

- Page 79, please explain/clarify the meaning of “correctly” in the following statement; 

additionally, please change the phrase “ignore that capital investments have already been made 

to meet the requirements of CAIR” to state “assume that capital investments have not already 

been made to meet the requirements of CAIR”: 

Similarly, if EPA were to ignore that capital investments have 

already been made to meet the requirements of CAIR and that 

these investments comprise “sunk” capital costs and not new 

costs, EPA’s analysis would not correctly reflect the cost of 

emission reductions required by the Transport Rule. 

Response: Please see attached redline to section V.B of the preamble for edits that EPA 

proposed to address this issue.

F. Canada and Mexico Emissions 
- Page 80 – can EPA add text explain how additional information or suspected trends for Canada 

and Mexico’s emissions would impact the modeled air quality? How does EPA know that the 

2006 Canada inventory and 1999 Mexico inventory lead to a conservative estimate of emissions? 

Response: EPA lacks sufficiently detailed information to determine “trends” in Canadian or 

Mexican emissions beyond the inventory data used in the Transport Rule air quality analyses. 

EPA agrees that it is unnecessary to characterize the analysis as “conservative.” Please see 

attached redline to section V.C.1 with EPA’s proposed clarifications. 

G. NOx Variability

- For clarity, can you further explain the following statement on page 247 – the explanation that 

follows the sentence explains why downwind air quality (AQ) is not heavily impacted by NOx, 

but it is not explained why the variation in SO2 emissions up to 20% does not have an impact:

This analysis shows that year-to-year fluctuations of up to 20 

percent in SO2 emissions from upwind states linked to a given 

downwind receptor do not undermine the ability of the Transport 

Rule programs to resolve nonattainment or maintenance concerns 

at that receptor. 

- Furthermore, this explanation on page 247 seems to imply that only SO2 variability was 

analyzed, yet there is discussion of NOx emissions and their relationship to downwind AQ. Can 

you clarify in the preamble if the sensitivity analysis was done for both? 

Response: Please see the attached “NOx variability in preamble” showing edits in redline that 

EPA proposes to this preamble section to clarify the relationship of SO2 and NOx and why 

EPA’s analysis of SO2 variability is relevant to both pollutants. These clarifications also 

note that the SO2 analysis is found in the variability TSD. 

H. Permitting

- Page 399: EPA has discussed the CO2 increases associated with the use of limestone-based 

scrubbers and with increased parasitic loads as two separate issues. Shouldn’t these two be 

combined, since an application of wet FGD would automatically result in an increased parasitic 

load? Also, since NOx and SO2 controls were added for CAIR, is there any data available on 

whether NSR was triggered on any of the affected units? Could this discussion be added to this 

section to support the response to comments on this. 

Response: EPA believes the preamble clearly identifies the permitting issues and makes it clear that all 

identified issues would need to be considered for future retrofits. EPA also notes that commenters did not 

provide the agency with any specific instances of CAIR retrofits triggering NSR, and that it would take 

several days to conduct a detailed review of historic permitting that is not feasible in the time remaining. 
EPA believes the preamble section accurately captures the permitting issues relevant to Transport Rule 

compliance.

I. Texas Sensitivity Analysis

- Suggest that the following language be added: 

"Also, coal-switching is only one of many ways by which Texas can comply; [EPA estimates] 

75% of Texas coal capacity will be scrubbed by 2012 and analysis shows that those units can 

increase their generation. Finally, natural gas-fired units benefiting from substantially expanding 

Texas natural gas supplies and low near-term prices can also increase their generation to help 

Texas cost-effectively meet its 2012 SO2 budget." 

Response:  EPA agrees with this addition and has included it in redline in the “Texas sensitivity analysis

findings in response to comments” document attached.  Please also see the last paragraphs of the

attached redline of section VII.C.2 for EPA’s proposed preamble reference to this more detailed

discussion in the record.