Minnesota Pollution Control Agency

520 Lafayette Road North I 5t.Paul,MN 55155-4194 I 651-296-6300 I 800-675-3843 651-282-5332 TTY www.pca.state.mn.us

March 24, 2010

Ms. Chrissy Bartovich

U.S. Steel Corporation

Minnesota Ore Operations

P.O. Box 417

Mt. Iron, MN 55768

Dear Ms. Bartovich:

The Minnesota Pollution Control Agency (MPCA) is in receipt of the following documents

recently submitted by US Steel Corporation Minnesota Ore Operations (Minntac): the Nitrogen

Oxides (NOx) Reduction Progress Update dated February 15,2010, and the Computational Fluid

Dynamics (CFD) modeling study results dated February 18,2010. The NOx Reduction Progress

Update was submitted in response to the MPCA's January 12,2010, letter to Minntac. The CFD

modeling report was submitted per the requirements of Air Emissions Permit No. 13700005-005.

CFD Modeling

Minntac requested that the CFD modeling report submitted on February 18,2010, be considered

confidential. Minntac must certify that the submittal qualifies for confidential treatment and

provide the appropriate rationale. Minntac should complete and submit to the MPCA the

Confidentiality Certification Form (CR-03) to justify why data in the CFD modeling report

qualifies for not public treatment based on Minn. Stat. § 13.37 and 116.075. The form describes

how confidential information must be submitted to the MPCA.

Please note that only specific data within a submittal can be considered confidential and not the

entire document. You will need to submit a public version of the document as explained on Form

CR-O3. The MPCA will review your,r~quest and respond in writing.

In addition, as we have discussed previously, when CFD modeling reports, with the confidential

arrange a meeting with the MPCA staff, the Federal Land Managers (FLMs), Minntac

representatives, and the CFD vendors to discuss and understand the contents of the report.

Proposed Installation Schedule for Low-NOx Main Burners

On April 16, 2009, the MPCA approved an installation schedule for low NOx main burners.

Minntac's February 15,2010, letter contained an alternative schedule that did not replicate the

MPCA-approved schedule. Minntac should follow the schedule approved on April 16, 2009.

Based on the approved schedule and recent conversations with Minntac, the MPCA believes that

Minntac will have the information that it needs to determine the degree of effectiveness of the

main burners by mid-July. The MPCA will initiate a meeting with Minntac in July to discuss the

NOx reduction being achieved by the Low-NOx Main Burners and the next steps.

St. Paul I Brainerd I Detroit Lakes I Duluth I Mankato I Marshall I Rochester I Will mar I Printed on 100% post-consumer recycled paper
Ms. Chrissy Bartovich

Page 2

Proposed Pilot Test Schedule for Regenerative Selective Catalytic Reduction (RSCR)

Minntac's proposed RSCR schedule would require submittal of the permit applicability

determination for the pilot test in mid-October, at the earliest. As stated above, the MPCA

believes that Minntac will have the information that it needs to determine the degree of

effectiveness of the Low NOx Main Burners in July 2010. If the Low NOx Main Burners, in

combination with process optimization, do not achieve the predicted NOx reductions of

60-90 percent, the MPCA would like Minntac to proceed with pilot testing of RSCR technology.

In order to minimize delay, Minntac should complete the preparation work needed to pilot RSCR

before July, including catalyst poison tests and requisite technical meetings with Babcock Power,

the MPCA and FLMs. The MPCA is happy to provide any assistance in completing these tasks.

LoTOx

At this time, the MPCA is not requiring further activities related to a LoTOx pilot test at

Minntac. The MPCA will continue to discuss potential applications of LoTOx at taconite

facilities with the technology vendor, and include Minntac in those discussions when

appropriate. Discussions regarding LoTOx pilot tests at Minntac will resume if the Low-NOx

main burners do not achieve the predicted reductions.

The MPCA looks forward to continued work with Minntac on potential NOx reduction

technologies. We encourage continued regular communication between MPCA and Minntac

regarding the NOx reduction technology testing efforts. Please contact me or Suzanne Baumann

if any communication, in addition to those required in approved schedules, would be useful.

r ",L...,, 

Sincerely,

{J(

Christopher \ Nelson, P .E., Man,ager

Metallic Mining Sector'

Industrial Division

CJN/SB :rn1

cc: Tishie Woodwell, US Steel

Mike Dzurinko, US Steel

Chrissy Bartovich, US Steel

Ryan Siats, US Steel

Stephanie Campbell, US Steel

Suzanne Baumann, MPCA

Owen Seltz, MPCA

Hongming Jiang, MPCA