# Minnesota Pollution Control Agency 520LafayetteRoadNorth I St.Paui,MNS5155-4194 I 651·296-6300 I 800-675-3843 I 651-282·5332 TIY I www.pca.state.mn.us November 20, 2009

Mr. Scott Coleman · General Manager US Steel Corp

- Minntac 8819 Old Highway 169 Mt. Iron, MN 55768 RE: Request for the Approval ofPilotTesting and Installation ofa Low Nitrogen Oxides Main Bumer on Agglomeration Line 7 atthe US Steel-Minnesota Ore Operations Minntac Facility Dear Mr. Coleman: This letter is in response to your July 15, 2009, letterto the Minnesota Pollution Control Agency (MPCA). regarding the proposed installation and pilot testing ofalow Nitrogen Oxides (NOx) main burner on Agglomeration Line 7 at the Minntac facility in Mountain Iron, Minnesota. In the letter, US Steel Cotp

- Minnesota Ore Operations Minntac (Minntac) requested the MPCA concurrence with its determination that the facility does not need an air emissions pennit amendment (administrative, minor, moderate, or major) to install and pilottest a low NOx main buiner on Agglomeration line 

### 7atMinntac. Minn. R. 7007.1150'dictates when an air permit amendment is needed based on several criteria. The MPCA does not exempt specific activities from the need to obtain apennit orpermit amendment, other than what is listed in Minn. 

### R. 7007. In orderto evaluate those criteriathe MPCA requested additional infonnation from Minntac o11 possible air emission impacts that could result from thebumerreplacement. This information request was fulfilled with a supplemental letter from Minntac dated November 12, 2009. The November 12, 2009, letter contained statements on behalfofthe vendors selected to design the low NOx main burner, Hatch Associates Consultants, Inc. and COEN Company, Inc. These statements addressed possible changes to fuel use rates, fuel mixes, and pollutant emissions that could result from the bumerreplacement. The infom1ation submitted byMinntac in the July 15, 2009, letter and subsequent November 12, 2009, letterwere ·used for the evaluation ofthe criteria in Minn. R. 7007.1150. Generally, when areduction in NOx emissions from fuel combustion is proposed the pollutant ofconcern for potential increase is carbon monoxide (CO). However, due to the design ofthe proposed low NOx main burner, CO emissions are not anticipated to increase. Furthermore, as explained in the manufacturers' letters dated November 3, 2009, and November 6, 2009, and submitted to the MPCA via Minntac's November 12, 2009, letter, due to the design and operation ofthe proposed burner, CO emissions are expected to decrease. An analysis ofthe CO emissions from the pilottest shouldbe included in the Pilot Test Results submittal as required by the Pem1ittee's Air Emission Permit No. 13700005-005. · Based on the information provided in the July 15, 2009, and November 12, 2009, letters, the MPCA concurs with Minntac's determination that an air emissions permit amendment (administrative, minor, moderate, or major) is notrequired for replacement and pilot testing ofa low NOx main burner on Minntac's Agglomeration line 7. The MPCA staffbasedthis conclusion on the following assumptions:
• The change does not increase emissions ofany regulated airpollutant. • The change does not allow for an increase in fuel consumption orproduction rates. • Cunent monitoring, recordkeeping and reporting practices are sufficient to demonstrate compliance with the applicable requirements
.

. St.Paul I Brainerd I DetroitLakes I Duluth I Mankato I Marshall I Rochester IWillmar I Printed on 100% post-consumerrecycled paper

### Mr. Scott Coleman 

### Page2
The current Air Emission Pem1itNo. 13700005-005 in which Minntac operates under, for purposes ofthe Retroactive Prevention ofSignificant Deterioration Program (PSD) Permitting Requirements, requires the Permittee to commence pilot testing ofselected NOx control technologies, upon written MPCA approval ofthe NOx control technology selection and test schedule as submitted in an Engineering Analysis Report as well as receipt ofpennit(s) as needed. Based on the above concurrence with Minntac's determination that the facility does not need an air emissions permit amendment (administrative, minor, moderate, ormajor) to install and pilot test a low NOx main burner on Agglomeration line 7, and a letter dated April16, 2009, from the MPCA approving a February 27, 2009, Engineering Analysis Report for the selection and test schedule ofthe proposedNOx control technologies, Minntac has final approval from the MPCA to install and pilot test alow NOx main burner on Agglomeration line 7. The low NOx main burner installation, pilot testing, as well as the associated monitoring, recordkeeping and reporting shall be conducted in accordance with the aforementioned documents and the Permittee'sAirEmission PermitNo
. 13700005-005
.Additionally, the MPCA requests anotification ofthe burnerreplacement within 15 days after the installation
. Furthermore, Air Emission PermitNo
. 13700005-005 (l)ages A-3- A-6) contains Retroactive PSD PermittingRequirements, which requires the pilot testing ofNOx control technologies, and the requirements for full scale demonstrations and incorporation ofselected technologies into the remaining Agglomeration lines atMinntac
.Ifthe low NOx main bumer approved in this letter for installation and pilot testing on Agglomeration line 7 is selected for full scale demonstration or installation on the remaining four Agglomeration lines at Minntac,the Pennittee must submit the required amendment(s) in accordance with Air Emission PermitNo. 13700005-005. Please be aware that new permit application fees, including fees for applicability detennination requests, will be effective retroactively to July 1, 2009. Applicability detennination requests received by the MPCA after July 1, 2009, and before implementation ofthe rule, are subject to the tiew fees and will be charged retroactive fees as necessary. For information, see the MPCA's website regarding the new fee mle: www.pca.state
.mn.us/petmits/airwaterfees
.html. Ifyou have any questions, please feel free to contact me at 651-757-2713. Your cooperation and compliance with environmental regulations are appreciated.

· Sincerely,

# tJ;:;-**-- ~** 

OwenSeltz**~** 

### Engineer Metallic Mining Sector Industrial Division OS:rm
cc: Chrissy Bartovich, U. S. Steel Tishie Woodwell, U.S. Steel Ryan Siats, U. S
.Steel Mike Dzurinko, U
. S
.Steel Chris Nelson, MPCA Hongming Jiang, MPCA Suzanne Baumann, MPCA AQFileNo. 26A