From: "Higgins, Cortney " <Cortney_Higgins@omb.eop.gov>

To: Sharon Nizich/RTP/USEPA/US@EPA

Cc: Steve Fruh/RTP/USEPA/US@EPA

Date: 08/03/2010 05: 47 PM Subject : Part of E.O. 12866 Review: Interagency Discussion about the revised RIA pertaining to NESHAP: Mercury Emissions from Mercury Cell Chlor

- Alkali Plants 2060

- AN99

Hi Sharon, Attached is a document with the interagen cy comment s received so far. I anticipate additional comments, especially on the RIA, but I'd like to use the time tomorrow to discuss the RIA.

We will also be sending suggested language on the mercury health effects, but it is not yet ready. When
characterizin g methylmercury health effects, the language is differen t between RIA and the preamble. Can you explain where the preamble language came from?

Please let me know if you have any questions.

Regards, Cortney

202.395.7856 (See attached file: InteragencyWorkin gCommentsonEPA_HgChlorAlkali_EO12866Review_08032010.pdf)***E.O. 12866 Review

– Draft

– Do Not Cite, Quote, or Release During Review***

EO12866_Mercury Emissions from Mercury Cell Chlor

- Alkali Plants 2060

- AN99 NPRM RIA _20100803

Interagency Working Comments on Draft Rule under EO 12866 8/3/2010

Below are additional working comments from the interagency review of the draft rule titled, “NESHAP: Mercury Cell Chlor

- Alk ali Plants, Amendments.”

General Comments :

1) Page 15: It is not clear why the detection limit is set at or below 0.5 times the mercury concentration measured during the test. What is the basis for the 0.5 factor? 2) Page 17: IV A refers to the propo sal of a zero mercury standard although this is contradictory to what is stated on page 13 in that zero mercury emissions are noted as “impossible”. Rather, this is a proposal for conversion to non

- mercury technology or closure of existing mercury technol ogies. We suggest this header be reworded to better reflect what the proposal is about. A similar statement of a “zero mercury standard” is on page 32 and we suggest this be revised. 3) Page 19: Consider inserting a paragraph describing mercury cell te chnology before the paragraph beginning, “Conversion from mercury cells to membrane cells...” 4) Page 29: Can you provide more information about “the data” that plant closure may be the owner’s preferred option? 5) Page 29: Mercury is described from ind ustrial sources and from mercury cell chlor

- alkali plants. Please clarify the “industrial sources” by providing examples and clarify liquid, particulate, and vapor states for the different species from “industry” and from the chlor

- alkali sector to make th is section more descriptive for the general reader. 6) Page 30: Can EPA be more specific about the predominant types of Hg emitted by these factilities in the following statement? Furthermore, can EPA explain the basis for the 12 month residence time gi ven for mercury in circulation within the global pool? “Mercury that is emitted can be atmospherically transported different distances depending on the species. While inorganic mercury is generally transported relatively short distances before depositing, elemental mercury, barring any topographical interferences, can enter the global pool and remain in circulation up to 12 months prior to deposition.” 7) Has EPA considered quantifying the social benefits of reduced energy demand by using the social

cost of carbon ( http://www.epa.gov/otaq/climate/regulations/scc

- tsd.pdf )? Reduced energy demand will result in reduced carbon emissions from power plants, and such reductions can be estimated, using the social cost of carbon, to quantify the social benefits. We suggest using the annual emissions from a 40 megawatt power plant, multiplied by the social cost of carbon, to estimate social benefits. 8) Page 34: Can EPA provide a list/information on examples of rules where the beyond the floor cost

effectiveness of mercury control has been similar to what is in this rule.

RIA

9) The energy savings co

- benefits are described in Chapter 5, and more information is found in

Appendix B. Can EPA provide the “XL” sheet referenced in the Appendix, as well as

informati on the COBRA model? Furthermore, what is the source of these emissions factors? “EPA’s eGrid database provided emission factors for NO X , SO 2 , CO 2 , and Hg (see attached XL spreadsheet). RTI calculated emission factors for pollutants for which EPA’s eGrid data

was unavailable. The Co

- Benefits Risk Assessment model (COBRA) provided total emissions estimates by fuel type and by pollutant for 2010.”

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