### RE:Clarificationonplantcapacityfactor-revisedUnits1&2BARTupdate. Parker,JamesM to:AaronWorstell 10/19/201101:56PM Cc: VanessaHinkle From: "Parker,JamesM"<jmparker@pplweb.com> 

### To: AaronWorstell/R8/USEPAlUS@EPA Cc: VanessaHinkle/R8/USEPAlUS@EPA Aaron. In looking back on the data, I found I may have told

### you the wrong years that we based our CF on. I have an inquiry to the person who actually put this information together and gave it to our consultant in 2007. He recently retired but is available for questions. I'll let 

### you know what find out
- on your most recent question and on the timeframe. Thanks. Jim -----Original Message----­ From: Worstell.Aaron@epamail.epa.gov [mailto:Worstell.Aaron@epamail.epa.gov] Sent: Tuesday, October 18, 2011 2:28 PM To: Parker, James M Cc: Hinkle.Vanessa@epamail.epa.gov Subject: RE: Clarification on plant capacity factor

- revised units 1&2 BART update. Jim- Thanks for your quick response. Can 

### you describe how the capacity factor for each of the five years was calculated? For example, is it based on the annual gross load (MWh) as reported to CAMD? Aaron J. Worstell Environmental Engineer u.S. Environmental ProtectionAgency

- Region 8 Air Program

- Mail Code 8P-AR 1595 Wynkoop Street Denver, CO 80202 Phone: 303-312-6073 Fax: 303-312-6064

From: "Parker, James M" <jmparker@pplweb.com> To: Aaron Worstell/R8/USEPA/US@EPA Cc: Vanessa Hinkle/R8/USEPA/US@EPA Date: 10/18/2011 01:15 PM Subject: RE: Clarification on plant capacity factor

- revised Units 1&2 BART update.

Aaron

- The capacity factor was developed in 2007, the date of our original BART submittal. The CF was derived by taking the average capacity factor of the five years 2003-2007, with the 2007 CF values used in the average being a projection to year's end (since the year wasn't complete at the time of the analysis)
. Also, pursuant to our correspondence last week, attached please find revisions for our Units 1&2 September 23, 2011 submittal. I've attached the revised Ipages and also a complete revised report. Please let me know if you have any questions. Thanks. Jim 406-237-6932

-----Original Message----­ From: Worstell.Aaron@epamail.epa.gov [ mailto:Worstell.Aaron@epamail.epa.gov] Sent: Tuesday, October lS, 2011 S:12 AM To: Parker, James M Subject: Clarification on plant capacity factor
Hi JimIn your NOx update for Colstrip 1 and 2 (September 2011), you use a plant capacity of 92%. Can you tell me how this was derived? Thanks in advance. Aaron J. Worstell Environmental Engineer u.S. Environmental Protection Agency

- Region S Air Program

- Mail Code SP-AR 1595 Wynkoop Street Denver, CO S0202 Phone: 303-312-6073 Fax: 303-312-6064 The information contained in this message is intended only for the personal and confidential use of the recipient(s) named above. If the reader of this message is not the intended recipient or an agent responsible for delivering it to the intended recipient, you are hereby notified that you have received this document in error and that any review, dissemination, distribution, or copying of this message is strictlyprohibited. If you have received this communication in error, please notify us immediately, and delete the original message. [attachment "NOX Control Update to PPL Montana's Colstrip Generatiing Station

- Revised pages(Oct2011).pdf" deleted by Aaron Worstell/RS/USEPA/US] [attachment "NOx Control Update to PPL Montana's Colstrip Generating Station BART Report (Revised).pdf" deleted by Aaron Worstell/RS/USEPA/US] The information contained in this message is intended only for the personal and confidential use of the recipient(s) named above. If the reader of this message is not the intended recipient or an agent responsible for delivering it to the intended recipient, you are hereby notified that you have received this document in error and that any review, dissemination, distribution, or copying of this message is strictlyprohibited. If you have received this communication in error, please notify us immediately, and delete the original message.

### RE:Clarificationonplantcapacityfactor
-revisedUnits1&2BARTupdate. Parker,JamesM to:AaronWorstell 10/18/201101:15PM Cc: VanessaHinkle From: "Parker,JamesM"<jmparker@pplweb.com> To: AaronWorstell/R8/USEPAlUS@EPA Cc: VanessaHinkle/R8/USEPAlUS@EPA 

### 2attachments !I:;n.-.·.···. NOXControlUpdateto

### PPlMontana'sCOISThmi

...GeneratiingStation
-Revisedpages(Oct2011).pdf**!~!** NOxControlUpdatetoPPLMontana'sColstripGeneratingStationBARTReport(Revised).pdf

Aaron

- The capacity factor was developed in 2007, the date of our original BART submittal. The CF was derived by taking the average capacity factor of the five years 2003-2007, with the 2007 CF values used in the average being a projection to year's end (since the year wasn't complete at the time of the analysis)
. Also, pursuant to our correspondence last week, attached please find revisions for our units 1&2 September 23, 2011 submittal. I've attached the revised pages and also a complete revised report. Please let me know if you have any questions. Thanks. Jim 406-237-6932

-----Original Message----­ From: Worstell.Aaron@epamail.epa.gov [mailto:Worstell.Aaron@epamail.epa.gov] Sent: Tuesday, October 18, 2011 8:12 AM To: Parker, James M Subject: Clarification on plant capacity factor
Hi JimIn your NOx update for Colstrip 1 and 2 (September 2011), you use a plant capacity of 92%. Can you tell me how this was derived? Thanks in advance. Aaron J. Worstell Environmental Engineer u.S. Environmental ProtectionAgency

- Region 8 Air Program

- Mail Code 8P-AR 1595 Wynkoop Street Denver, CO 80202 Phone: 303-312-6073Fax: 303-312-6064 The information contained in this message is intended only for the personal and confidential use of the recipient(s) named above. If the reader of this message is not the intended recipient or an agent responsible for delivering it to the intended recipient, you are hereby notified that you have received this document in error and that any review, dissemination, distribution, or copying of this message is strictlyprohibited. If you have received this communication in error, please notify us immediately, and delete the original message.

### RE:UncontrolledNOxRateforSCR-Colstrip1and2 Parker,JamesM 

### to:AaronWorstell 10/13/201103:05PM Cc: VanessaHinkle From: "Parker,JamesM"<jmparker@pplweb.com> 

### To: AaronWorstell/R8/USEPNUS@EPA Cc: VanessaHinkle/R8/USEPNUS@EPA Aaron

- Your observation is correct. The "uncontrolled" Nox value in table 2-3a should be 0.20 #/MMBtu. This change flows through to Table 2-3b, such that the cost of application is slightly lower because of lower reagent preparation equipment, urea, and other minor costs. The $/ton goes down from $7,405 to $7,300. We will revise the report accordingly and submit revised pages to you. Thank you for catching that inadvertent error, and my apologize for any confusion this may have caused. Jim 406-237-6932
-----Original Message----­ From: Worstell.Aaron@epamail.epa.gov [mailto:Worstell.Aaron@epamail.epa.gov] Sent: Thursday, October 13, 2011 9:44 AM To: Parker, James M Cc: Hinkle.Vanessa@epamail.epa.gov Subject: Uncontrolled NOx Rate for SCR

- Colstrip land 2 Hi JimI'm reviewing the IPM calculations for SCR in your September 2011 NOx control update for Colstrip Units 1 and 2. The "NOx Emiss Rate" in Table 2-3a is shown as 0.26 lb/MMBtu. In the following table, Table 2-3b, "Uncontrolled Emissions" are shown as 0.20 lb/MMbtu. Both tables address SCR reductions on a 30-day average emissions basis. Did you intend for the NOx emission rate in Table 2-3a to be 0.20 lb/MMBtu, reflecting installation of SOFA system? Aaron J. Worstell Environmental Engineer U.S. Environmental ProtectionAgency

- Region 8 Air Program

- Mail Code 8P-AR 1595 Wynkoop Street Denver, CO 80202 Phone: 303-312-6073 Fax: 303-312-6064 The information contained in this message is intended only for the personal and confidential use of the recipient(s) named above. If the reader of this message is not the intended recipient or an agent responsible for delivering it to the intended recipient, you are hereby notified that you have received this document in error and that any review, dissemination, distribution, or copying of this message is strictlyprohibited. If you have received this communication in error, please notify us immediately, and delete the original message.