EGU MACT -- Interagency Request for Comment Higgins, Cortney to: RobertJ Wayland

03/15/2011 07:28 PM Cc: Bill Maxwell, Peter Tsirigotis, Kevin Culligan

Hi Bob,

I’ve heard from interagency reviewers that had a chance to review the response to comment documents. The list below highlights those issues that they want to make sure have request for comments, and a second list of issues that were not addressed that the suggest be considered for the final rule. Can you make sure the first list is addressed in the preamble?

Thanks,

Cortney

Issues that should be highlighted for comment: * EPA should seek public comments on the approach (99% UPL) used to account for variability of emissions during different unit operating

loads. * EPA appears to have made several assumptions to come to a conclusion that installation of 65 GW of FGD retrofits can be accomplished within planned outages for all affected units. Some of these assumptions, e.g., whether many units have spare absorbers, must be confirmed by the industry. It is true that several of the older FGD installations have multiple scrubbers, but they may usually be designed to have multiple vessels with each less than 100% capacity (e.g., 2x50%). Upgrade of these vessels may still require partial outages, affecting availability. We are recommending that EPA clearly show their assumptions with regards to FGD upgrades in the preamble and solicit public comments on them. * It is recommended that, in addition to EPA’s further review of the issues raised regarding the use of baghouses, EPA should seek information and public comments on these issues (primarily, is there sufficient space for retrofits).

* The number of units affected and controls installed for CAIR were totally different than what is required by the Toxic Rule. EPA’s analysis does not address the issues involved with the resources required for this rule. This is another important issue where EPA should seek information/comments from public to obtain the information needed to perform a proper analysis for the final rule. * It is critical that EPA perform comprehensive modeling of the impact that all proposed rules for all media (316b, NSPS for GHG, CCW, and any others) would have on coal plant retirements. Retirement decisions will not be made on a single rule but on the total expected investment required for compliance. We recommend that EPA seek public comments on

coal retirement issue.

Comments that were not responded to but EPA should consider while drafting the final rule:OMB File: Summary of Interagency Working Comments on draft EGU MACT under EO 12866 Interagency Review_ 03 10 2011_Response_031411.doc 1. Page 6 – Response to Comment on Page 10, Last Paragraph: We agree with the use of a baghouse with a 6.0 A/C ratio for the ACI service. However, if the baghouse is being used in the service of trona-based DSI system, an A/C ratio of 4.0 would be required. 2. Page 7 – Response to Comment on Page 13, Table 5-18: Please add the

size-cost correlation factors as a note to this table. EPA has done this for all other technologies. This is necessary for a proper review of these costs, especially for smaller units. 3. Page 7 – Response to Comment on Page 15, Last Paragraph: EPA has not addressed the main concern expressed in this comment. No basis for the $100/kW cost has been provided. This represents a major cost and it should be supported by a study and/or references to the costs incurred at actual retrofit projects. 4. Page 8 – Response to Comment on Page 5, Table 1: Please revise Table 1 to show the FGD upgrades resulting from EPA’s analysis. In addition, EPA appears to have made several assumptions to come to a conclusion that installation of 65 GW of FGD retrofits can be accomplished within planned outages for all affected units. Some of these assumptions, e.g., whether many units have spare absorbers, must be confirmed by the industry. It is true that several of the older FGD installations have multiple scrubbers, but they may usually be designed to have multiple vessels with each less than 100% capacity (e.g., 2x50%). Upgrade of these vessels may still require partial outages, affecting availability. We are recommending that EPA clearly show their assumptions with regards to FGD upgrades in the preamble and solicit public comments on them. 5. Page 9 – Response to Comment on Pages 12 to 14: EPA’s response does not address the issues raised in the comment. First, the document listing the project completion times should be revised to reflect correct times (this will also change some of the text). Second, work done for CAIR has a relationship to the work required for the Toxic Rule only for the units planning to install FGD controls. A lot more planning is required to confirm the technologies that would be required to comply

with the emission limits in the Toxic rule. EPA cannot make an assumption that plants will be able to complete all preliminary engineering work before the final rule and will be ready to award the equipment contracts right after the final rule is issued. It would be more appropriate for EPA to use conservative assumptions, given the complexity of this rule and the fact that the final rule may contain changes requiring selection of different compliance approaches. 6. Page 11 – First Bullet Item: EPA has not done any analysis to show that combining multiple units to share a single control will result in any cost saving or will be possible for a significant number of affected units. Lack of a proper space to place common controls, costs of long ductwork, increased auxiliary power loads, reliability issues, and the potential need for a new stack may not allow such an option to be exercised on a significant scale. Please also note that a common baghouse for multiple units may not reduce costs significantly, since the baghouses use air-to-cloth ratios for design.

OMB File: Summary of Interagency Working Comments on draft EGU MACT under EO 12866 Interagency Review_ 03 04 _Response_031411.doc* Page 27 – Comment on Page 466, Section V.M, Last Paragraph: It is agreed that there are some options that can be installed for improving an existing ESP performance. However, we also believe that the level of ESP performance required to achieve the emission limits for this rule would not be met with such options. It also appears that EPA has done no analysis to back its claim on this issue.