# • Minnesota Pollution Control Agency
520 Lafayette Road North I St. Paul, MN 55155-4194 I 651-296-6300 I 800-657-3864 I 651-282-5332 TTY I www.pca.state.mn.us


### January 18, 2011

Ms

. Chrissy Bartovich U

.S. Steel Corporation Minnesota Ore Operations- Minntac P.O. Box 417 Mountain lron, MN 55768
RE: Nitrogen Oxides Control Technology Pilot Testing
Dear Ms. Bartovich:
This letter is in response to the October 22, 2010, report from U.S

. Steel Corporation Minnesota Ore Operations- Minntac (Minntac) to the Minnesota Pollution Control Agency (MPCA) regarding nitrogen oxides (NOx) control technology pilot test requirements contained in Air Emissions Permit No. 13700005-005. The air emissions permit for the facility contains stepwise requirements to test NOx control technologies with the goal ofachieving greater than 70 percent NOx emissions control from the initial permit limit of 13,300 tons per yearNOx. In the October report Minntac provided preliminary pilot test results from the low NOxmain burner installed on Line 7, a schedule for continued pilot testing on Line 7, and a schedule for installation and pilot testing on Line 6. The MPCA, Federal Land Managers, and Minntac met on December 13, 2010, to discuss the effort to date. During the meeting several follow-up items were identified. This letter responds to the October 22, 2010, report and provides direction to U.S. Steel Corporation for future testing, including approximate permitting timelines for major permit modifications. 

### Line 7 Low NOx Main Burner Pilot Test Minntac installed a low NOx main burner on Line 7 in May 2010. Minntac has provided information demonstrating continued achievement ofexcellentNOx control efficiencies while combusting natural gas. Despite redesigning the burnertip twice, Minntac stated that it has not been able to achieve the same level ofemissions reductions when combusting coal and biomass. Minntac stated that while combusting coal, the Line 7 burner has continued to produce a short, bushy flame which results in reduced NOxcontrol efficiency and warps the kiln refractory.
In September 2010, the MPCA requested that Minntac submit the results ofthe pilot test results conducted to date including technical feasibility and impact to pellet quality, significantNOx reduction, cross media impacts, multi-pollutant co-control benefits, energy efficiency or consumption impact, and economic feasibility

. The MPCA is required, perMinntac's air permit, to evaluate the pilot test results using that data. In the October 22,2010, report Minntac provided

St. Paul I Brainerd I Detroit Lakes I Duluth I Mankato I Marshall I Rochester IWillmar I Printed on 100% post-consumer recycled paperMs. Chrissy Bartovich Page 2

briefdescriptions regarding the above items, but because it had not yet installed the second redesigned burnertip or completedpilot testing while combusting biomass, any report provided at that time would've been incomplete. Instead Minntac submitted an amended schedule for providing the final results ofthe Line 7 pilot testing. The MPCA approves the schedule proposed in the October report, pending the inclusion ofquarterly updates to the MPCA. The quarterly update can be as simple as an e-mail to the MPCA contacts, but should provide information so that the MPCA can track the status ofthe effort; including the installation dates and the other measures used as milestones in the proposed schedule.
Per the schedule provided, Minntac will be submitting the final report on the Line 7 low NOx main burnerpilot testing approximately in June 2011. The MPCA expects that the final report will contain data in greater detail than the briefdescriptions provided in the October preliminary report so that the MPCA can use the data provided to evaluate the control technology. When submitting the final report, ifMinntac intends to submit protected data, please be mindful ofthe MPCA's confidentiality requirements; including submittal of justification for confidentiality and providing two copies ofthe report, one confidential and one with the protected data redacted. 

### Line 6 Low 

### NOx Main Burner Pilot Test Despite its efforts to redesign the Line 7 lowNOx main burnertip, Minntac stated that it has achieved limited improvements to NOx control efficiency while combusting coal. 

### It also stated that it was having biomass delivery problems; the burner isn't able to feed biomass into the burner at an adequate rate for production.
For these reasons, Minntac has proposed to redesign and reconfigure a new low NOx main burnerto try to eliminate the flame shape problems occurring during coal combustion on Line 7. To this end, Minntac submitted to the MPCA a schedule for installing and pilot testing a redesigned burner on Line 6.
Per our request in the September 2010 letter, the MPCA approves the proposed Line 6 pilot test schedule pending inclusion ofa quarterly update so that the MPCA can track the status ofthe piJot testing effort. 

### Permitting Timelines to meet February 1, 2014, Full Scale Installation Goal Sixty days after the MPCA approves the final NOx emission control pilot testing results, Minntac is required to submit a major permit amendment for "full scale demonstration;" installation ofthe chosen technology on a single agglomerating line. Following full scale demonstration, the permit requires a major permit amendment for "full scale installation;" installation ofthe chosen technology on all operating agglomerating lines at the plant. The major permit amendment is an important part ofthe process because it allows for public participation and provides some level of regulatory certainty for Minntac.

### Ms. Chrissy Bartovich Page 3

Becausethere is no wayto pilot test a low NOx mainburnerwithout full scale installation, the line between a pilot testing and full scale demonstration is blurred. ButtheMPCAbelieves that Minntac will have sufficientlyrefined the technology during the Line 6 low NOxmainburnerpilot testing, so that any future proposed lowNOx mainburner installations canno longer be considered pilot tests and will trigger require majorpermit amendment requirements prior to installation

. Minntac's air emissions permit contains a goal ofinstallation ofNOxcontrols on all agglomerating lines byFebruary 1, 2014. The major amendmentprocess canrequire a significant amount oftime. In addition to drafting the permitlanguage, there are numerous administrative requirements that add time to permitting

. In orderto meetthe February 1, 2014, installation goal it is important that Minntac consider the timing ofthe majorpermit amendment submittal. The time required to issue the permit is dependent on a number offactors, including the completeness ofthe application, the number and complexity ofcomments received, etc. So, the following are rough estimates for some ofthe major steps in the major amendment process: 

### Major Modification Milestones Time Estimates 1. MPCA reviews the application submitted byMinntac and determines that it Start is complete 2

. MPCA drafts permit and discusses the permit terms Varies 3. MPCAinternal peerreview 14 days 4

. MPCA seeks feedback from Minntac, tribes and FLMs 15 days 5. MPCA receives feedback, adjusts the language, and finalizes the permit Varies, generally approx. 30 days 6. Minntac submits permit application reflecting the final permit language, if 45 days significant changes have occurred since the application was submitted. Concurrently, MPCAprepares permit for public notice

. 7. Public notice 30 days 8. EPA45 day review period. In 

### some cases it is possible for this review to be 45 days concurrent with the public notice

. 9

. 

### Ifrequested to comebefore the MPCA Citizen's Board for issuance, MPCA 45-60 days prepared responses to comments and prepares for the board meeting. 10. Permit issued 5 days after Citizen's BoardMeeting 11. EAB Appeal Period (PSD permits only) 45 days
Please be cognizant ofthe above time requirements when submittingpermit amendment applications to complywith the February 1, 2014, control installation goal.

### Ms. ChrissyBartovich Page 4

The MPCAlooks forward to continuingto work with U.S. Steel Corporation on achieving the NOx emission reductions required byits permit. Ifyou have any questions orconcerns, please contactme at 651-757-2603

. Sincerely,

ChristopherJ. Nelson, P.E., Manager Strategic Projects Sector Industrial Division CJN /SLB:lao

cc: Trent Wickman, US Forest Service Don Shepherd, National Park Service David Pohlman, National Park Service Tishie Woodwell, U.S. Steel Corporation Mike Dzurinko, U

.S. Steel Corporation James Jarvi, U.S

. Steel Corporation Suzanne Baumann,MPCA