# Appendix 10.13

Table 10-16

Reference 4: Page 79 of "Colorado Visibility and Regional Haze S tate Implementation Plan for 12 Mandatory Class I Federa l Areas", January 7, 2011Colorado Visibility and Regional Haze State Implementation Plan f or 12 Mandatory Class I Federal Areas Colorado Dept. of Public Health and Environment, Air Pollution Control Divisi on Approved January 7, 2011 **1** 

# Colorado Visibility and Regional Haze State Implementation Plan for the Twelve Mandatory Class I Federal Areas in Colorado

Colorado Air Pollution Control Division

Revised Regional Haze Plan Air Quality Control Commission, approved 01/07/2011Colorado Visibility and Regional Haze State Implementation Plan f or 12 Mandatory Class I Federal Areas Colorado Dept. of Public Health and Environment, Air Pollution Control Divisi on Approved January 7, 2011 **79 Drake Unit 7 - SO**  **2 Cost Comparison** 

**Alternative Emissions**  **Reduction (tpy) Annualized Cost**  **($) Cost Effectiveness** 

**($/ton)**
**Baseline 0**  **$0 $0** 
**DSI 2,657**  **$3,723,826 $1,405**  **Dry FGD (LSD) @ 82% control (0.15 lb/MMBtu annual average)**  **3,632 $8,216,863**  **$2,263**

**Dry FGD (LSD) @ 85% control (0.12 lb/MMBtu annual average)**  **3,764 $8,829,321**  **$2,345**

**Dry FGD (LSD) @ 90% control (0.08 lb/MMBtu annual average)**  **3,986 $9,898,382**  **$2,483**



### The energy and non-air quality impacts of the remaining alternative are as follows: **DSI - reduced mercury capture in the baghouse, fly ash contamination with sodium sulfate, rendering the ash unsalable as a replacement for concrete and**  **rendering it landfill material only Dry FGD** 

– **less mercury removal compared to unscrubbed units, significant water usage**  **There are no remaining useful life issues for the alternatives as the sources will remain in service for the 20-year amortization period.**  **The projected visibility improvements attributed to the alternatives are as follows:**

**SO2 Control Method**  **Drake**

– **Unit 5 Drake** 

– **Unit 6 Drake** 

– **Unit 7 SO2**  **Emission Rate**  **(lb/MMBtu) 98th** 

**Percentile Impact**  (Δdv) **SO2**

**Emission Rate**  **(lb/MMBtu) 98th** 

**Percentile Impact**  (Δdv) **SO2**

**Emission Rate**  **(lb/MMBtu) 98th** 

**Percentile Impact**  (Δdv) **Daily Max (3-yr) 0.94**  **1.00 0.99**  **DSI (annual avg.)**  **0.25 0.12**  **0.33 0.18**  **0.33 0.29** 

**Dry FGD (LSD) (annual avg.)**  **Not**

**feasible 0.12**  **0.24 0.12**  **0.39**

**Dry FGD (LSD) (annual avg.)**  **Not**

**feasible 0.07**  **0.26 0.07**  **0.41**



### Based upon its consideration of the five factors summarized herein and detaile **d in Appendix C, the state has determined that SO2 BART for Unit 5 is the following SO2**  **emission rate: Drake Unit 5: 0.26 lb/MMBtu (30-day rolling average)**  **The state assumes that the BART emission limit can be achieved through the installation and operation of dry sorbent injection. Other alternatives are not feasible.**  **Unit 5: $1,760 per ton SO2 removed; 0.12 deciview of improvement**Colorado Visibility and Regional Haze State Implementation Plan f or 12 Mandatory Class I Federal Areas Colorado Dept. of Public Health and Environment, Air Pollution Control Divisi on Approved January 7, 2011 **80** 

### Based upon its consideration of the five factors summarized herein and detaile **d in Appendix C, the state has determined that SO2 BART for Unit 6 and Unit 7 is the**  **following SO2 emission rates: Drake Unit 6: 0.13 lb/MMBtu (30-day rolling average)**  **Drake Unit 7: 0.13 lb/MMBtu (30-day rolling average) The state assumes that the BART emission limits can be achieved through the**  **installation and operation of lime spray dryers (LSD). A lower emissions rate for Units 6 and 7 was deemed to not be reasonable as increased control costs to achieve such**  **an emissions rate do not provide appreciable improvements in visibility (0.02 delta deciv**  **iew for both units respectively).**  **These emission rates for Units 6 and 7 provide 85% SO2 emission reduction at a modest cost per ton of emissions removed and result in a meaningful contribution to**  **visibility improvement. Unit 6: $2,808 per ton SO2 removed; 0.24 deciview of improvement**  **Unit 7: $2,345 per ton SO2 removed; 0.39 deciview of improvement**

Particulate Matter BART Determination for Martin Drake - Units 5, 6 and 7

**The state determines that the existing regulatory emissions limit of 0.03 lb/MMBtu (PM/PM10) for the three units represent the most stringent control options. The units**  **are exceeding a PM control efficiency of 95%, and the emission limits are BART for PM/PM**  **10.** 

### The state assumes that the BART emission limit can be achieved through t **he operation of the existing fabric filter baghouses.** 

NOx BART Determination for Martin Drake - Units 5, 6 and 7 **Ultra low NOx burners (ULNB), ULNB including OFA, SNCR, SNCR plus ULNB, and SCR were determined to be technically feasible for reducing NOx emissions at Drake**  **Units 5, 6 and 7. The following tables list the emission reductions, annualized costs and cost**  **effectiveness of the control alternatives:**

**Drake Unit 5 - NO x**  **Cost Comparison**

**Alternative Emissions**  **Reduction (tpy) Annualized** 

**Cost ($) Cost** 

**Effectiveness ($/ton)**  **Baseline 0**  **$0 $0**  **Overfire air (OFA) 154**  **$141,844 $923**  **Ultra-low NOx burners (ULNBs) 200**  **$147,000 $736** 
**ULNBs + OFA 215**  **$288,844 $1,342**  **Selective Non-Catalytic Reduction (SNCR) 231**  **$1,011,324 $4,387**  **ULNB/SCR layered approach 626**  **$4,467,000 $7,133**  **Selective Catalytic Reduction (SCR) 626**  **$4,580,000 $7,314**