UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 8 1595 Wynkoop Street DENVER, CO 80202-1129 Phone 800-227-8917 http://www.epa.gov/region08

September 3,2010

Ref: 8ENF-L

Via US Mail & Email Mr. Terry O'Clair Director, Division ofAir Quality North Dakota Department ofHealth 918 East Divide Avenue, 2nd Floor Bismarck, ND 58501-1947

Re: Transmittal ofBurns & McDonnell's114 Response and Remaining Concerns

DearMr. O'Clair:

In a letter dated July 6,2010, the United States Environmental Protection Agency (EPA) requested certain information from Burns & McDonnell (B&McD) under Section 114(a) ofthe Clean Air Act, 42 U.S.C. § 7414(a). Enclosed are the transmittal letter and the B&McD response. Please note the Bums & McDonnell response contains information that is classifiedby the vendor as Confidential Business Information (CBI). Onpage 3 ofthe transmittal letter, B&McD agrees to allow EPA to provide this informationto North Dakota Department ofHealth (NDDH). EPA has maintained the CBI designation and transmitted that information in accordance with the federal policies regarding CBI. EPA has not reviewed this informationto ascertain ifit is CBI, and is not taking a position as to whether or not such a claim is valid. EPA requests thatNDDH treat this CBI information in accordance with its process for handling CBI found atNDAC 33-15-01-16 and any other applicable state laws.

EPA is also enclosing recent information for inclusion in the administrative record for the DraftNOx BACT Determination at Milton R. Young Station (MRYS). This new information is related to costs that other states have found acceptable for purposes ofdetermining Best Available Control Technology (BACT). The Colorado Air Pollution Control Division (the Division) has recently submitted BestAvailable Retrofit Technology (BART) determinations to its Air Quality Control Commission (the Commission) as part ofaproposed revision to its Visibility and Regional Haze State Implementation Plan (SIP) dated August 5, 2010. On pages 48 and 49 ofthis proposal, the Division notes that a cost effectiveness of$5,000/tonvalue is reasonable for a variety ofregulatory purposes and is consistent with its BACT determinations. Specifically, the Division states, "control costs for Colorado BACT canbe inthe range of $5,000/ton (and higher)." While this proposal has not been finalized by the Commission for 

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PrinlsdonRecyoJed Pape,purposes ofthe BART, it does documentthat Colorado has found $5,000/ton (and higher) to be reasonable for BACT determinations.

Minnkota and B&McD continue to assertthat any SCR application atMRYS is technically infeasible, despite NDDH's July 

### 15,2009, determination that low-dust selective catalytic reduction (LDSCR) and tail-end selective catalytic reduction (TESCR) are technically feasible at MRYS. EPA reviewed the budgetaryproposals that Minnkota and B&McD obtained from two catalyst vendors, CERAM and Haldor Topsoe, Inc., for LDSCR and TESCR at MRYS. Based onthe information submittedby Minnkota and B&McD to these catalyst vendors, and after several meetings betweenthe parties, the vendors recommended slipstream pilottesting data for MRYS priorto providing a catalyst life guarantee.

Minnkota's and B&McD'sjustificationfor eliminating SCRtechnology as being "technically infeasible" is purportedly based upon EPA;s October 

### 1990 DraftNew Source Review Workshop Manual (the NSR Manual) Section B.IV. EPA reiterates that both Minnkota and B & McD have incorrectly interpreted the NSR Manual. The NSR Manual does state that "technologies inthe pilot scale testing stages ofdevelopment would not be considered available for BACT review." The vendors have not suggested "pilot scale testing" relating to the development ofSCRtechnology. Rather, they have recommended testing to further understand catalyst deactivation rates at MRYS. It is clearfrom the catalyst vendorproposals that SCRis commercially available and technically feasible at MRYS. In fact, the two catalyst vendors were willing to provide guarantees on every aspect ofthe catalyst, otherthan the catalyst life guarantee (i.e. NOx rates, ammonia slip, S02 conversion, etc.). The lack ofa catalyst life guarantee is simply a matter ofriskmanagement onthe part ofthe catalyst vendor. The NSR Manual explicitly states that a "lackofa vendor guarantee by itselfdoes notpresent sufficient justificationthat a control option or an emissions limit is technically infeasible." Althoughthe catalyst vendors were apparently concerned aboutthe amount ofcatalyst deactivation data for plants firing North Dakota lignite, this datacould easily be obtained ifMinnkota wanted to have the assurance ofa catalyst life guarantee. 1 EPA has never objectedto Minnkota obtaining this data during the nearly ten-yearperiod ofdiscussing the feasibility ofSCR at MRYS.2

The extensive history ofapplying SCR to boilers ofwide-ranging fuel types (bituminous, subbituminous, lignite, brown coals, biomass, petcoke) and process types (municipal and hazardous waste incinerators, cement kilns, glass furnaces, etc.) is evidence that SCR is a commercially-available control option and not in the "developmental" stages. EPA fully concurs with NDDH's standing determination that LDSCR and TESCR are technically feasible at MRYS. As stated in ourMay 

### 10,2010, comment letter, SCR is clearly economically feasible at MRYS.

1 Minnkota has repeatedly expressed concern regarding the range ofsodium in Center Mine lignite coal. The BACT analysis must consider coal blending to mitigate any potential adverse impacts from the upper range ofsodium levels in the coal. 2 During this period, pilot testing and the application ofSCR on Texas lignite for the first time has taken place.

2Enclosures

cc: Jerry MacLaughlin, DOJ JeffKodish, EPA, OECA Hans Buenning, EPA, ENF-AT

# S~d1-/~ Brenda L. Morris, SeniorEnforcement Attorney U.S. EPA Region 8 Tel: 303-312-6891 Fax: 303-312-6953 morris.brenda@epa.gov

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