## Minnesota Pollution Control Agency
520 lafayetteRoad North 

### I St. Paul, MN 55155-4194 

### I 651-296-6300 

### I 800-675-3843 

### I 651-282-5332 TTY 

### 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 ofPilot Testing and Installation ofa Low Nitrogen Oxides Main Burner on Agglomeration Line 

### 7 at the US Steel- Minnesota Ore Operations Minntac Facility Dear Mr. Coleman: This letter is in response to your July 15, 2009, letier to the Minnesota Pollution Control Agency (MPCA) regarding the proposed installation and pilot testing ofa low Nitrogen Oxides (NOx) main burner on Agglomeration Line 

### 7 at the Minntac facility in Mountain Iron, Minnesota. In the letter, US Steel CorpMinnesota Ore Operations Minntac (Minntac) requested the MPCA concurrence with its determination that the facility does not need an air emissions permit amendment (administrative, minor, moderate, or major) to install and pilot test a low NOx main burner on Agglomeration line 7 at Minntac. Minn. R. 7007.1150 dictates when an airpermit amendment is needed based on several criteria. The MPCA does not exempt specific activities from the need to obtain a petmit or permit amendment, other than what is listed in Minn. R. 7007. In order to evaluate those criteria the MPCArequested additional information from Minntac on possible air emission impacts that couldresult from the burner replacement. 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 burner replacement. The information submitted byMinntac in the July 15,2009, letter and subsequent November 12, 2009, letter were used for the evaluation ofthe criteria in Minn. R. 7007.1150. Generally, when a reduction 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 fi·om the pilot test should be included in the Pilot Test Results submittal as required by the Pern1ittee'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 not required for replacement and pilot testing ofa low NOx main burner on Minntac's Agglomeration line 7. The MPCA staffbased this 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 Detroit Lakes 

### I Duluth 

### I Mankato 

### I Marshall 

### I Rochester 

### I Willmar 

### I Printed on 100% post-consumer recycled paperMr. Scott Coleman 

### Page2

The cmTent Air Emission Pem1it No. 13700005-005 in which Minntac operates under, for purposes ofthe Retroactive Prevention ofSignificant Deterioration Program (PSD) Petmitting Requirements, requires the Permittee to commence pilot testing ofselected NOx control technologies, upon written MPCA approval oftheNOx control technology selection and test schedule as submitted in an Engineering Analysis Report as well as receipt ofpermit(s) as needed. Based on the above concunence with Minntac's detennination that the facility does not need an air emissions permit amendment (administrative, minor, moderate, or major) to install andpilot test a low NOx main burner onAgglomeration line 7, and a letter dated April16, 2009, from the MPCA approving a Febmary 27, 2009, Engineering Analysis Report for the selection and test schedule ofthe proposedNOx control technologies, Minntac has final approval from the MPCA to install andpilot test a low NOx main burner on Agglomeration line 7. The lowNOx 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's Air Emission Permit No. 13700005-005. Additionally, the MPCA requests a notification ofthe burner replacement within 15 days after the installation. Furthennore, AirEmission PennitNo. 13700005-005 (pages A-3- A-6) contains Retroactive PSD Petmitting Requirements, which requires the pilot testing ofNOx control technologies, and the requirements for full scale demonstrations and incorporation ofselected technologies into the remaining Agglomeration lines at Minntac. Ifthe lowNOx main burner approved in this letter for installation and pilot testing on Agglomeration line 7 is selected for full scale demonstration or installation onthe remaining four Agglomeration lines at Minntac, the Permittee 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 determination requests, will be effective r etroactively to July 1, 2009. Applicability determination requests received bythe MPCA after July 1, 2009, and before implementation ofthe tule, are subject to the new fees and will be charged retroactive fees as necessary. For infonnation, 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,

# (};;;**~** 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 AQ File No. 26A