## Summary of Interagency Working Comments on Draft Language under

EO s 12866 and 13563 Interagency Review. Subject to Further Policy Review.

1 **Comments on the Feasibility TSD,**  **Employment Estimates of Direct Labor in Response to the Proposed Toxics Rule in 2015**  **document, and Preamble**  **for the MATS Rule**
1. **MATS Feasibility TSD, Page 6 and Table 2** : In this feasibility document 1 , it is stated: “EPA has adopted a single metric to represent all APC technologies in this analysis. Use of a single metric facilitates an extrapolation of historic deployment rate data for wet and dry FGD and SCR to assess feasible future deployment rates needed for the retro fit technologies projected for MATS. Such a single metric permits assessment of the overall combined feasibility of all APC retrofits projected. This metric should be regarded as “average,” not capturing the specifics of any particular site, but representi ng average difficulty across many projects.” For the single metric mentioned above, EPA assumes that the industrial resources required for furnishing and installing each environmental control technology option for compliance with MATS can be projected as a percentage of the resources required for a wet FGD system, with this percentage being defined as a ratio of the capital costs for the control technology option and wet FGD scrubber. EPA has not provided any technical justification to prove that a cost ra tio can be used for the determination of industrial resource requirement in this manner **. We suggest that EPA add a reference in support of this assumption.**  In support of the above concern, we also note that EPA has prepared and issued another technical su pport document 2 for MATS, which shows different resource requirements for the same technologies included in the first document. For example, comparing the information in Tables A

- 1 and A

- 2 of the second document to the information in Table 2 of the first document, the following discrepancies are obvious:

 In the first document, the resource requirements for fabric filter (FF) are shown at 30% of that for wet FGD. However, in Tables A

- 1 and A

- 2 of the second document, the labor and steel requirements for F F are listed at 52 and 63% of that for wet FGD, respectively.

 For SCR (see the comment below), the resource requirements are shown at 40% of that for wet FGD in the first document, whereas the second document lists the labor and steel requirements for SCR at 92% and 111% of that for wet FGD.

 The second document also shows that boilermaker hours required for FF and SCR are higher percentages of the total manhours, as compared to the boilermaker hours for wet FGD.

1 “An Assessment of the Feasibility of Retrofits for the Mercury and Air Toxics Standards Rule,” U.S. Environmental Protection Ag ency, Office of Air and Radiation, Final Draft, November 2011 2 “ Employment Estimates of Direct Labor in Response to the Proposed Toxics Rule in 2015,”EPA Docket Number: EPA

- HQ

- OAR

- 2009

- 0234

## Summary of Interagency Working Comments on Draft Language under

EO s 12866 and 13563 Interagency Review. Subject to Further Policy Review.

2  The information provided in the second docume nt is backed by references, one of which is a detailed study 3 conducted by EPA in 2002. In comparison, as mentioned above, no references are provided to back the assumptions in the first document.

 Use of the above capital cost ratio to define the resource requirements for FGD upgrades and ESP modifications appear to be even more questionable, since making changes to existing equipment at the plant site may be more resource intensive compared to optimized methods usually employed to shop manufacture and install new equipment. We are requesting EPA to specifically review their assumptions for these two options shown to be exercised by a large number of GW capacity.
2. **MATS Feasibility TSD, Page 11:** A proposed timeline for the installation of environmental c ontrols within the allowable compliance time period has been presented on this page. Please note that certain plants complying with the CSAPR would also be installing controls, FGD, SCR, etc., in about the same timeframe as that for MATS. In addition, se veral industrial facilities will be installing similar controls to comply with the industrial MACT. There is a concern that the combined impact of these three rules could be greater than that envisioned by EPA in this TSD. Can EPA responds to this commen t?
3. **MATS Acid Gas Floor, General Comment:** A commenter is concerned about the application of dry sorbent injection (DSI) as a viable acid gas compliance alternative to flue gas desulfurization (FGD), and that its use has been overstated. This is based on t he pollution control configurations of the units in the MATS acid gas floor. In the proposed rule, there were 130 units used to calculate the acid gas MACT floor for existing units

– this represents the best performing 12%. Of this 131, 11 units (less tha n 10%) had DSI installed. These units are plotted in Figure 1 (“MATS Acid Gas Floor Units Employing DSI”). The largest eight units in Figure 1 (Montrose Units 1, 2, and 3; Ghent Unit 1; Cardinal Units 1 and 2; Conesville Unit 4; Mountaineer Unit 1) use DSI solely for the purpose of SO 3 control, not HCl or SO 2 . For acid gas control (as proposed under MATS), all eight of these units have FGD installed. The remaining three units with DSI installed (Arapahoe Unit 3; Cherokee Units 1 and 2) may not be repres entative of the type of plant that EPA has assumed is willing to install this technology. Cherokee Units 1 (107 MW) and 2 (106 MW) are both smaller, older units that have proposed retirement dates (the units came online in 1957 and 1959, respectively). In addition, there is a 569 MW NGCC being constructed onsite which is expected to come online in 2015. Therefore, these units are likely using DSI as a cheap compliance option until retirement.

3 “Engineering and Economic Factors Affecting the Installation of Control Technologies for Multipollutant Strategies,” EPA

- 600/R

- 02/073

## Summary of Interagency Working Comments on Draft Language under

EO s 12866 and 13563 Interagency Review. Subject to Further Policy Review.

3 Likewise, Arapahoe Unit 3 (44 MW, online in 1951) has DSI i nstalled, but also has an announced retirement date. Similar to the Cherokee Power Station, there is a 480 MW NGCC pending approval by the Colorado Public Utility Commission at the Arapahoe Station. Therefore, it may be the case that Arapahoe Unit 1 does not view DSI as a long term solution, but as a cheap, temporary method to control SO 2 emissions until retirement. It does not appear that there are any units in the MACT acid gas floor that are using DSI as a long

- term compliance solution for acid gas con trol. Therefore, the willingness of industry to adopt DSI as a viable alternative to FGD may have been overstated.

## Summary of Interagency Working Comments on Draft Language under EO s 12866 and 13563 Interagency Review. Subject to Further Policy Review.

4 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

0 200 400 600 800 1000 1200 1400**C u** **m u** **l a** **t i** **v e** **C a** **p a** **c i** **t y** **( %** **)**



## Uni **t Siz**  **e (MW**  **)** Mountaineer Unit 1: DSI used for SO3 control Conesville Unit 4: DSI used for SO3 control

Cardinal Unit 1, 2: DSI used for SO3 control

Ghent Unit 1: DSI used for SO3 control Montrose Unit 1, 2, 3: DSI used for SO3 control

Cherokee Unit 1,2: Proposed 2011 retirement 569 MW NGCC permitted, online in 2015 DSI likely being used as cheap compliance so lution until retirement Arapahoe Unit 3: Proposed 2013 retirement 480 MW NGCC pending CO PUC approval DSI likely being used as cheap compliance solution until retirement

## Summary of Interagency Working Comments on Draft Language under

EO s 12866 and 13563 Interagency Review. Subject to Further Policy Review.

5 **Additional Comments on the Preamble** 

### Page 318, Table 3: Clarifications are requested f or the following emission limits: Existing Unit designed for Coal > 8,300 Btu/lb , Mercury, 1.2E0 lb/Tbtu (2.0E

- 2 lb/GWh): These emission limits are only equivalent when the gross plant heat rate is ~16,667 Btu/kWh, or a 20.5% efficient plant. This is not representative of an existing unit. Therefore, these are really two different limits. Which one will an existing unit be held to?

**Page 572:** We refer to the statement on this page: “Only those units that begin construction, modification, or reconstruction after May 3, 2011, will be affected by the final rule.” Will this apply ret roactively to units meeting these criteria that already have air quality permits? There is a legal prece dent (Xcel case) for preventing retroactive application of new permit levels for units that have already obtained permits

.