ASH GROVE CEMENT COMPANY
 

-----C ~--:-----

WESTERN REGION
 

100 HWY. 516
 

CLANCY. MT 59634-9701
 

PHONE 406 I 442-6855
 

FAX 406 I 442·9262
 

May 5,2008 

Ms. Callie A. Videtich, Director 

Air and Radiation Program 

United States Environmental Protection Agency 

Region 8 

1595 Wynkoop Street 

Denver, Colorado 80202-1129 

RE:	 Ash Grove Cement - Montana CitY Plant 

Response to Comments on Best Available Retrofit Technology (BART) Analysis 

Dear Ms. Videtich: 

Ash Grove Cemen~Company (Ash Grove) recently submitted responses to comments provided 

by the U.S. Enviro~meritalProtection Ag~Dcy (USEPA) Region 8 on the BARTFive Factor 

Analysis dated JUD~ 2007 for our Montana City plant. In preparing the responses to comments, 

Ash Grove providep some infonnation on the cost of changing fuels that was different than the 

information provid~d in the original BART analysis. Ms. Kasi Dubbs ofTrinity Consultants has 

briefly discussed the different information with Ms. Laurel Dygowski. Ms. Dygowski requested 

that Ash Grove clarify and/or revise any information in the original BART analysis, as necessary, 

so that EPA is not left to interpret what information from the original BART analysis is no longer 

valid. This letter identifies the infonnation that was updated by Ash Grove during the preparation 

of the responses to comments. 

The original BART analysis indicated that the sulfur content of the existing coke used at the plant 

was 4.5%. Since the submittal of the original BART analysis, Ash Grove has determined that the 

sulfur content of the existing coke is actually 5.2%. The original BART analysis also assumed 

that a 50% reduction in inlet fuel sulfur would result a 50% reduction in S02 emissions. Further, 

the analysis assumed that the inlet fuel sulfur could be cut by 50% by using a fuel blend that is 

11% coke and 89% coal, where the specific coal and coke assumed for the blend are the same 

coal and coke that are currently burned at the plant. Since the submittal ofthe original BART 

analysis, Ash Grove has determined that the maximum amount of coal that can be utilized in the 

fuel blend without adversely affecting the quality ofthe clinker, is a blend of 38% coke and 62% 

coal. Further, Ash Grove concluded that a 50% reduction in the inlet fuei sulfur would Dot drop 

S02 emissions by 50%, since a portion ofthe S02 emissions are not generated from the sulfur in 

the fuel but rather are generated from the sulfur in the kiln feed. The sulfur in the kiln feed 

cannot be changed. 

PC~ PDrll.nd Cement As>act.lI", 

IUIdIEIi 
In responding to the EPA's comments on fuel switching, Ash Grove provided a revised cost 

analysis for fuel switching that considers the revised information presented above. The cost for 

reducing S02 based on using the existing fuels, but switching to a blend that is 38% coke and 

62% coal, was detelmined to be $2,995/ton S02 removed. The revised cost infol111ation should 

replace the information presented in Section 4.4.2 ofthe original BART analysis. 

If you have any questions concerning the infol111ation in this letter, please feel free to contact me 

at 406-442-8855. 

Sincerely, ( 

.' 

~.

Richard Johnson 

Plant Manager-Montana City