### Summary	of	Interagency	Working	Comments on	the	Draft	Language	under

EO 12866/1356 3	Interagency	Review.	Subject	to	Further	Policy	Review.

**ENVIRONMENTAL PROTECTION AGENCY (EPA )**  **Updated Version of 111(b) RIA and Response to Interagency Comments General Comments**  1) Reviewer recommends clarifying whether the sentence on page 1 -4 which includes “new non compliant natural gas -fired combustion turbine units” is referring to simply cycle combustion turbine units. 2) Reviewer recommends clarifying whether the reference on page 4 -4 to AEO 2013 should instead refer to 2014. 3) Reviewer recommends clarifying page 4 - 11, in the notes under figure 4 - 1, whethe r the renewables list should include wind. 4) Reviewer recommends clarifying whether the reference to “cofiring with 14 percent natural gas” on page 5 - 19 is correct. **Technical Comments** 1) Reviewer recommends updating page ES - 2 to reflect the revised preamble. a. S pecifically the sentence about “BSER for natural gas -fired stationary combustion turbines” and the “1,080 lb CO2/MWh” reference 2) Reviewer recommends updating table ES - 1 to reflect the revised preamble. 3) Reviewer recommends reconciling the note under Table 4 - 3 to ensure consistency with the definition of “high economic growth” scenario in Table 4 -4. 4) Reviewer recommends reconciling the notes under figure 5 - 1 about NG co -firing of 43% with the text in the paragraph above. 5) Reviewer recommends clarifying the acco unting for the greenhouse gas benefits of biomass energy in the RIA. Reviewer notes that the EPA SAB stated that it was not scientifically valid to assume that all biogenic feedstocks are carbon neutral, not is it scientifically valid to equate full stack emissions from biomass combustion with fossil sources. Despite this, EPA assumes a biomass emission factor of 195, equivalent to the direct stack emissions from biomass combustion. This is an inconsistency between the RIA and the language of the rule. **Ty pographical Comments**  1) Reviewer recommends editing the sentence on page 1 - 2 which reads “has explained in detail how emissions of CO2 from the source category here cause or contribute significantly to the air pollution which endangers.” 2) Reviewer recommends e diting the sentence on page 2 - 8 to read “Transmission is the term used to describe the bulk transfer of electricity”. 3) Reviewer recommends editing page 2 - 26 to refer to “highly efficient coal -fired designs” rather than “highly efficiency”. 4) Reviewer recomm ends editing page 4 - 8 to delete “projection is” in the sentence including “reference case is ‘projection is a business - as - usual...” 5) Reviewer recommends editing page 4 - 8 to delete “in” from “2030 in is projected to...”

### Summary	of	Interagency	Working	Comments on	the	Draft	Language	under

EO 12866/1356 3	Interagency	Review.	Subject	to	Further	Policy	Review. 6) Reviewer recommends editing page 4 - 12 to replace “than” with “that” in the bullet titled State Renewable Portfolio Standards (RPS). 7) Reviewer recommends adding “in” on page 4 - 25 to the sentence including “For technologies that are included in the IPM Base Case...” **8)** Reviewer recommends rewording the sentence on page 5 - 14 that reads “In this scenario, we expect some compliance costs if a new NGCC unit...”