November 12, 2009

Catherine Neuschler Environmental Analysis & Outcomes Division Minnesota Pollution Control Agency 520 Lafayette Road North

St. Paul, MN 55155-4194

Re: Hibbing Taconite Company Proposal of Mo dified Alternative Monitoring Methods for Nitrogen Oxides Emissions

Dear Ms. Neuschler,

The purpose of this letter is to request:

1. Modification of Hibbing Taconite Company’ s (HTC’s) alternative monitoring methods for nitrogen oxides (NOx) emissions orig inating from the indurating furnaces.

2. Contingent upon Minnesota Pollu tion Control Agency (MPCA) approval of the modified alternative monitoring methods for NOx, removal of condition 10.f. contained in HTC’s Administrative Order by Consent (AO), which requires “installation a nd certification of permanent stack gas flow monitors”.

As you may be aware, in 2008 HTC experienced pr emature failure of stack gas flow monitors after only two months of operati on in each of the twelve indurating furnace stack vents. HTC has worked extensively with th e flow monitor vendor to comple te preliminary testing of two redesigned flow monitors, in the hope of identifying a suitable design. However, HTC was recently informed that its flow monitor warranty claim has been denied by the vendor, and that any future purchase of flow monitors and re lated components will not be associated with a warranty of any kind. Consequent ly, additional testing of the re designed flow monitors is required to fully assess future operating and maintenance costs, as well as to make a determination relative to overall technical feasibility.

HTC’s indurating furnaces are currently scheduled to resume production in April 2010, at which time additional testing of the redesigned flow monitors could begin. Given the anticipated time requirements associated with additional testing; determination of flow monitor economic and technical feasibility; a 12-14 week lead time fo r manufacture of twelve new flow monitors; and

calibration / certification of new flow monitors, NOx data coll ection at HTC would likely be delayed until late 2010 or early 2011.Due to these facts, HTC requests MPCA to a pprove the use of modified NOx predictive equations to directly calculate NOx mass emi ssion rates on a pound per hour basis without the need to operate and maintain stack gas flow m onitors. The modified predictive equations meet the AO acceptance requirements contained in 10.d. and will allow for the immediate collection of continuous NOx emission data upon restart of each temporarily idled indurating furnace in April 2010. This will allow both HTC and the MPCA to maintain adherence to the NOx data

collection schedule contained in Minnesota’s Regional Haze State Implementation Plan, for purposes of establishing a Best Available Retrofit Technology (BART) NOx limit for HTC in a timely manner.

HTC’s detailed proposal is contained in the attached enclosure, with the modified NOx alternative monitoring methods to be discussed at a November 16, 2009 meeting at the MPCA’s

St. Paul office. Please cont act me at (218) 262-5970 or andrew.mcdowell@cliffsnr.com with any questions concerning this matter.

Sincerely, Hibbing Taconite Company

Andrew S. McDowell Environmental Manager

Cc: Ed LaTendresse (HTC) Jason Aagenes (Cliffs) Hongming Jiang (MPCA)

Enclosure