## MONTANA SULPHUR & CHEMICAL COMPANY

627 ExxonMobil Road • P O Box 31118 Billings, Montana 59101 • Billings, Montana 59107

- 1118 Phone: (406)

- 252

- 9324 • Fax: (406) 252

- 8250

February 6, 2012

Vanessa Hinkle, 8P

- AR U.S. Environmental Protection Agency

R egion 8 1595 Wynko op Street Denver, CO 80202

- 1129

Dear M s

. Hinkle :

The attached report is our response to EPA’s letter dated December 30, 2011, postmarked January 3, 2012

, and received January 6, 2012, requesting additional Reasonable Progress informati on for the Montana Sulphur & Chemical Company ( MSCC ) facility located near Billings , Montana. As requested, MSCC has (via Bison Engineering, Inc.) conducted an analysis of “ control options ” fo r the potentially affected sulfur plant at the MSCC facility

. Th e work addresses “SCOT” type technology

, as we understood from discussion that it was specifically of interest. This work included

, to the

extent feasible given severe time restraints for response

, the four factors included in 40

CFR § 51.308(d)(1)(i)(A) : t he costs of compliance, the time necessary for compliance, the energy and non

- air quality impacts of compliance, and the remaining useful life of the potentially affected sources.

On January 13, 2012, we requested an extension to the 21

- day deadline to r espond to

the request. EPA granted MSCC an extension until February 6, 2012

. Although we appreciate the extension, the February 6, 2012

, deadline did not allow MSCC to

conduct a s thorough an analysis of potential emission control technologies as would

have been ideal. We believe that the short timeframe provided to MSCC limited the scope of this analysis. Given more time, MSCC /Bison would have contacted more vendors that specialize in emissions control at sulfur recovery plants , and possibly

received additi onal responses from vendors contacted . Nonetheless, the attached report represents our best effort to respond to EPA’s request , given the limitation . If, despite evidence to the contrary found in the attached report, EPA determines that MSCC will be requir ed to further study alternatives or further control emissions from the facility, we do not wish to be limited to the two example technologies identified in the attached report. This is a reasonable request given MSCC ’ s previous efforts to reduce

emissions

, such as installing two SuperClaus systems at the plant, and due to the limited timeframe provided to MSCC to respond to EPA’s January 2012 request for

information

.If you have any questions or need further information , p lease contact me at MSCC

( 406

- 252

- 9324 ) , or Hal Robbins or Grant Rodway at Bison Engineering

, Inc

. (406

- 442

- 5768)

. Similarly, as this process progresses, I woul d appreciate the opportunity to hear from you regarding any ideas or proposals that may be under consider ation

.

Sincerely,

Larr y Zink

President

Enc losureSTATEMENT OF CERTIFICATION

I certify under penalty of law that I have personally examined and am familiar with the information submitted in this document and all attachments and that, based on my inquiry of those immediately responsible for obtaining this information, I believe that the information is true, accurate and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine or imprisonment.

Signature: __

_________________________________

Title: ______________________________________

Date: _______________________________________