MinnkotaPower

[!VIPQ coo PER A T I V E, INC.

1822 Mill Road· P.O. Box 13200 • Grand forks, NO 58208-3200 • Phone (701) 795-4000

November 12, 2009

Mr. Terry O'Clair

Director, Division of Air Quality

North Dakota Department of Health

918 E. Divide Avenue, 2nd FI

Bismarck, ND 58501-1947

Your Touchstone Energy· Parmer ""'~

-

RE: NOx Best Available Control Technology Analysis Study - Supplemental

Reports for M.R. Young Station Units 1 and 2, dated November 2009

Dear Mr. O'Clair:

In accordance with the July 27, 2006, new source review enforcement consent decree,

Minnkota Power Cooperative, Inc. ("Minnkota") submitted a NOx Best Available Control

Technology Analysis Study to the North Dakota Department of Health ("NDDH") on

October 4, 2006. Based on this submission, as supplemented by responses to various

comments by NDDH and the U.S. Environmental Protection Agency ("EPA"), NDDH

issued its preliminary Best Available Control Technology Determination ("BACT

Determination") on February 27, 2008. The preliminary BACT Determination concluded

that selective catalytic reduction ("SCR") technologies were technically infeasible at

Minnkota's Milton R. Young Station ("MRYS") Unit 1 and Unit 2. Consequently, NDDH

did not analyze SCR technology beyond Step 2 of EPA's Top-Down BACT Analysis

method. Subsequently, NDDH determined that low-dust and tail-end SCR technologies

were technically feasible and in a letter dated July 15, requested that Minnkota submit

an economic analysis and other information required by Steps 3 and 4 of the top down

BACT analysis process for low dust and tail end SCR applications at Milton R. Young

Station.

In response to this request, please find enclosed two reports entitled "NOx Best

Available Control Technology Analysis Study - Supplemental Report for M.R. Young

Station Unit 1" and "NOx Best Available Control Technology Analysis StudySupplemental Report for M.R. Young Station Unit 2", both dated November 2009. This

analysis is supplemental to Minnkota's original October 2006 BACT Analysis as well as

all other materials Minnkota has submitted in this proceeding.

The enclosed reports indicated both low dust and tail end SCRs are not economically

acceptable on either Unit 1 or Unit 2. For Unit 1, the Unit Control Costs(UCCs) range

from a low of $3,944/ton to a high of $6,597/ton for the low dust or tail end options with
Advanced Separated Over Fire Air. These UCCs are approximately 270 percent to 525

percent of the UCC for SNCR w/ASOFA. The incremental costs per ton from SNCR

w/ASOFA to a low dust or tail end SCR option range from a low of $7,058 to

$15,550/ton. All of these cost parameters show low dust and tail end SCRs are not

economically acceptable.

Under the prevailing standard of review, People to Save the Sheyenne River, Inc. v.

North Dakota Dept. of Health, 697 NW.2d 319 (N.D. 2005), NDDH's BACT

Determination is entitled to significant deference, and may only be set aside if-based

on the record before it-NDDH's decision was the product of an irrational mental

process or if a reviewing court can discern no rationale for the decision. EPA submitted

comments on the BACT Determination on July 31 , 2008, expressing its disagreement

with a number of technical conclusions, chief among them that neither SCR technology

was technically feasible at MRYS. EPA suggested that NDDH complete the remainder

of the Top-Down BACT Analysis process for SCA. NDDH requested that Minnkota

prepare a supplement to its original October 2006 BACT Analysis and include the

balance of the Top-Down BACT Analysis approach for SCR technology. Minnkota is

confident that under the People to Save the Sheyenne River standard, NDDH's

February 2008 BACT Determination was based on a rational mental process supported

by a rationale evident in the record. More specifically, Minnkota believes that its

submissions and NDDH's original February 2008 BACT Determination are correct: lowdust and tail-end SCR technologies are technically infeasible at MRYS Unit 1and Unit 2,

because of problems associated with catalyst fouling and deactivation, primarily through

concentrations of alkali mineral compounds; This is bolstered by the fact that the two

catalyst vendors Minnkota worked with while doing the in depth cost analysis told us

that they would not offer any catalyst life guarantees without extensive testing. This

both supports the prior conclusions reached by Minnkota and the NDDH as to the

potential of catalyst poisoning and that SCT technology is not currently "available" for

application at either unit at Milton R. Young Station.

Minnkota believes that the total record, both technical and economic, supports a finding

that Advanced Separated Over-fire Air with Selective Non-catalytic Reduction

constitutes BACT for Milton R Young Station Units 1 and 2.

Should you have any questions concerning this submittal, please contact me at 701-

795-4221.

Sincerely,

MINN OTA POWER COOPERATIVE, INC.

John T. Graves,

£~~ P.E.

Environmental Manager

C: David Sogard

Ron Rutherford, USEPA