Addendum to DEQ BART Report for the Boardman Power Plant (November 11, 2010)

Page 1 INTRODUCTION:

PGE and several citizen groups asked DEQ to re

- open the comment period on proposed pollution
control rules for the Boardman coal

- fired power plant to consider new information. PGE

propose d a new approach to satisfying the Clean Air Act BART requirements that would require the Boardman Plant to meet increasingly stringent emission limits, close the plant no later than December 31, 2020, and eliminate existing rules that allow the plant to op era te indefinitely. DEQ proposed rules that would address PGE’S request and re

- opened the comment period from October 29 through November 15, 2010. Provided below is DEQ’s BART analysis for the new proposal

.

CONTROL TECHNOLOGY I NFORMATION

A discussion of the feasible control options is provided in the BART report prepared on September 1, 2010. The new proposal does not evaluate any new controls, but re

- assesses the control effectiveness, cost effectiveness, and visibility improvement associated with the control options. Provided below is a summary of the feasible controls, the dates they would be employed, and the remaining useful life taking into consider ation the plant close s on December 31, 2010.

Feasible Controls:

Visibility Impairing Pollutant Control technology Date of operation Remaining useful life (years)
NOx Low NOx burners with over

fire air (LNB) 7/1/11 9.5

Selective non

- catalytic reduction (SNCR) 7/1/14 6.5

Selective catalytic reduction (SCR) 7/1/17 3.5

SO2 Reduced sulfur coal

restriction (RSCR) 7/1/14 6.5

Dry sorbent injection (DSI) 7/1/14 6.5
Semi

- dry flue gas desulfurization (SDFGD) 7/1/14 6.5

Wet flue gas desulfurization (WFGD) 7/1/14 6.5

PM Fabric filter (FF) 7/1/14 6.5

Provided below is a summary of the control effectiveness, emissions reductions, and visibility improvement for each of the control technologies.Addendum to DEQ BART Report for the Boardman Power Plant (November 11, 2010)

Page 2 Control Effectiveness:

Visibility Impairing Pollutant Control

technology Emission limit

(lb/MMBtu) Annual emission

reduction (tons/yr) a Visibility

improvement (dV) b

NOx LNB 0.23 4,756 1.44

SNCR w/LNB 0.19 5,729 1.62
SCR w/LNB 0.070 8,647 2.17
SO2 RSCR 0.60 331 0.43

RSCR/DSI 0.55 1,545 0.53
DSI

- 1 0.40 5,188 0.84
DSI

- 2 0.30 7,616 0.98
SDFGD 0.12 11,988 1.24
WFGD 0.070 13,202 1.19
PM FF 0.012 122 <0.1

a. The baseline for determining emissions reductions is the highest annual emission during 2003 for each pollutant. NOx = 10,349 tons; SO2 = 14,902, PM = 417
b. Improvement is based on 22 nd highest day impact in the Mt. Hood Wilderness area over the period of 2003 to 2005. Mt. Hood Wilderness is the highest impacted Class I area.

Provided below is a summary of the costs associated with each control technology considering the remaining usefu l life of the plant/technologies.

Cost effectiveness:

Visibility Impairing Pollutant Control

technology Capital Cost

(1000$) a Total

Annual ized C ost (1,000$) a Cost

effectiveness ($/ton) Incremental

cost effectiveness ( $ /ton)
NOx LNB 31,585 5,358 1,102

---

SNCR w/LNB 43,960 11,595 1,987 6,413

SCR w/LNB 223,651 74,189 8,475 21,452
SO2 RSCR 0 0 0

---

RSCR/DSI 22,932 17,541 b

--- DSI

- 1 22,932 17,541 3,375 3,611
DSI

- 2 22,932 17,541 c c SDFGD 352,915 78,259 6,523 8,929
WFGD 417,837 101,336 7,670 19,005
PM FF 100,442 22,842 186,102

---

a. PGE estimate August 27, 2010 (2010 dollars)
b. This value is not calculated because RSCR/DSI is a fallback limit in case the DSI

- 1 limit cannot be met due to negative impacts on mercury and fine particulate matter controls.

c. These values are not calculated because DSI

- 2 is required in 2018, which is after the BART compliance period (e.g., 5 years after SIP approval).Addendum to DEQ BART Report for the Boardman Power Plant (November 11, 2010)

Page 3 SELECTION OF BART:

If adopted as proposed, the BART/Regional Haze rules would require closure of the coal

- fired power plant by December 31, 2010, consistent with PGE’s request. Taking into consideration the remaining useful life of the control technologies associated with p lant closure, DEQ has determined that the following control technologies satisfy the BART requirements for the reasons provided.

Nitrogen Oxides (NO x ):

Low NO x burners with over

- fire air (LNB) technology is considered BART because the technology is cost ef

fective and provides significant visibility improvement (>1 dV in Mt. Hood wilderness area). In addition, LNB can be installed as soon as 2011, providing 9.5 years of
emission reductions.

Selective non

- catalytic reduction ( SNCR ) was considered, but rejected because the technology provides only an additional 0.18 dV improvement in the Mt. Hood wilderness area ( l ess improvement in all other wilderness areas) as compared to LNB . In addition, there is concern
that ex cess ammonia emi ssions could produce fine particulate matter emissions that may have an adverse impact on the fine particulate (PM 2.5 ) ambient air quality.

Selective Catalytic Reduction ( SCR ) is not required because under the current rules adopted in 2009, the technology is not required to be installed until July 1, 2017, and the technology would
not be cost effecti ve for 3.5 years of operation.

Sulfur dioxide (SO 2 ):

Reduced sulfur coal restriction (RSCR) is not considered BART because it would only provide
0.43 dV visibil ity improvement in the Mt. Hood wilderness area. This level of improvement is not considered significant enough to satisfy the BART requirements.

Dry sorbent injection is considered to meet the BART requirements because it is cost effective and will provi de significant visibility improvement (>0.5 dV) in at least the Mt. Hood wilderness
area. Based on installation s on smaller boilers, DSI can achieve emission reductions of 30 to 70%. Considering the size of the Boardman unit (duct geometry and exhaust ga s flow), a DSI system may perform in the lower range of the control effectiveness, but the effectiveness could be improved with additional operating experience. Therefore, DEQ proposes a limit of 0.40 lb/MMBtu (35% emission reduction ) in 2014 to satisfy t he BART requirements. The limit is lowered to 0.30 lb/MMBtu (51% emission reduction) in 2018. The limit i n 2018 could be met by further refinements to the DSI system or in combination with ultra

- low sulfur coal or supplemental fuels, such as biomass.

PGE has raise d concerns that DSI could negatively impact the mercury controls scheduled to be installed in 2011 as required by other DEQ rules. In addition, PGE is concerned that DSI willAddendum to DEQ BART Report for the Boardman Power Plant (November 11, 2010)

Page 4 generate fine particulate matter that would result in a requirement to install a fabric filter. The limits proposed by DEQ are intended to be met with the existing electrostatic precipitator (ESP) PM control equipment. The addition of a fabric filter would be cost prohibitive considering closure of the plant by December 31 , 2020 , as shown above . In order to address PGE’s concerns, the proposed rules include provisions for conduct ing pilot studies prior to the compliance dates in 2014 and 2018. The studies will evaluate commercially available sorbents, injection zones, and ESP collection efficiency. If it is determined that the DSI system would negatively impact the mercury controls or require a fabric filter, PGE may propose an alternative limit that will be established in the permit. The alternative limit must be the lo west achievable
emissions limit without negatively impacting the mercury controls or requiring a fabric filter, but may not exceed 0.55 lb/MMBtu in order to achieve at least 0.5 dV improvement in the Mt. Hoo d wilderness area. For purposes of BART, 0.5 dV i s considered significant and less than 0.5 is not considered significant

.

Semi

- dry flue gas desulfurization (SDFGD) and wet flue gas desulfurization (WFGD) are not considered to meet the BART requirements because they are not cost effective considering
clo sure of the plant in 2020. The cost effectiveness of WFGD is $7,670/ton and the incremental cost of SDFGD is $8,929/ton, both considered too high for BART.

Particulate Matter:

The current electrostatic precipitator ( ESP ) is considered BART for particulate matter. A fabric filter is not cost effective and reductions in PM emission do not provide a noticeable improvement in visibility.

REGIONAL HAZE/BART S UMMARY:

BART control technology Compliance
Date Emission

Reduction ( NO x and SO 2 tons/yr) Mt. Hood

Visibility Impacts Visibility

Improvement Baseline

---- --- 4.98

--- LNB 7/1/11 4,756 3.54 1.44
DSI

- 1 7/1/14 9,944 2.57 2.41
DSI

- 2 7/1/18 10,917 TBD* TBD Plant Closure 12/31/20 12,373 0 4.98 *Running model, results should be available by 11/19.Addendum to DEQ BART Report for the Boardman Power Plant (November 11, 2010)

Page 5 SUPPLEMENTAL INFORMA TION:

Provided below is a table showing the visibility improvement in all Class I areas due to low NOx
burners with and without selective non

- catalytic reduction. As shown, SNCR does not provide significant visibility improvement. The maximum improvement is 0.18 dV in the Mt. Hood
wilderness area.

LNB/SNCR visibility improvement:

22nd high dV:

Class I ar ea 22 nd High dV
SNCR Improvement LNB (0.23 lb/MMBtu)) SNCR

(0.19 lb/MMtu)) Alpinae Lakes 1.564 1.484 0.080
Diamond Peak 0.757 0.730 0.027 Eagle Cap 1.611 1.528 0.083 Glacier Peak 1.008 0.959 0.049 Goat Rocks 1.702 1.611 0.091 Hells Canyon 1.435 1.367 0.068
Mt. Adams 1.899 1.772 0.127
Mt. Hood 3.537 3.356 0.181
Mt. Jeffereson 2.355 2.251 0.104
Mt. Ranier 1.478 1.416 0.062 Mt. Washington 1.711 1.635 0.076
Norch Cascades 0.747 0.710 0.037 Strawberry Mountain 1.281 1.204 0.077 Three Sisters 1.622 1.563 0.059 Columbia River Gorge 2.787 2.641 0.146

Maximum 3.537 3.356 0.181

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