### Addition to Colorado Docket Laurel Dygowski Laurel Dygowski to: Crystal Freeman 09/17/2012 07:23 AM

Can you add the following string of e-mails/attachment to the Colorado docket. It is not a public comment but it is supporting information. Can you title it "7/16 E-Mail from Lisa Clarke to Laurel Dygowski Pertaining to Fuel Switching at CENC" THanks

**** Note - New Mailing Address

Laurel Dygowski Regional Haze Coordinator Air Quality Planning Unit US EPA - Region 8 1595 Wynkoop Street Denver, CO 80202-1129 303-312-6144 ----- Forwarded by Laurel Dygowski/R8/USEPA/US on 09/17/2012 07:24 AM -----

From: "Clarke, Lisa M." <Lisa.Clarke@dphe.state.co.us> To: "Clarke, Lisa M." <Lisa.Clarke@dphe.state.co.us>, Laurel Dygowski/R8/USEPA/US@EPA Cc: "Taipale, Curtis D." <Curtis.Taipale@dphe.state.co.us>, "Kaufman, Garry W."

<Garry.Kaufman@dphe.state.co.us>, "King, Kirsten L." <Kirsten.King@dphe.state.co.us>, "Hea, Roland C." <Roland.Hea@dphe.state.co.us>, "Allison, William" <William.Allison@dphe.state.co.us> Date: 07/16/2012 03:24 PM Subject: RE: CENC 4 and 5 - fuel switching question from Laurel



### Hi Laurel,

Attached is the CENC BART Cost Analysis as discussed. Again, this is a draft version of the cost analysis, so all of the cost alternative calculations ($/ton) for the other options may not line up with the submitted SIP. The cost tables are in the “CEN Alternatives – BART SO2 Avg.” and “CEN Alternatives – BART NOx Avg” tabs. It should be clarified that the over $25,000/ton costs are for SO2 – Boiler 4 - $29,985/ton and Boiler 5 - $30,945/ton. The costs for NOx are as follows: $64,102/ton (Boiler 4) and $82,834/ton (Boiler 5). Costs for fuel switching to natural gas are widely variable by unit and determined on a case-by-case basis.

I appreciate the opportunity to look at the draft portion of the notice before it goes out . Please let me know if you have any other questions or comments.

Thanks, Lisa

Lisa Clarke, M.S./P.E. Air Quality Planner/Engineer Planning & Policy Program Air Pollution Control Division Colorado Department of Public Health and Environment 4300 Cherry Creek Drive South Denver, CO 80246-1530303-692-3117| lisa

. clarke @ state

. co

. us

From: Clarke, Lisa M. Sent: Monday, July 09, 2012 1:22 PM To: 'Laurel Dygowski' Cc: Taipale , Curtis D.; Kaufman, Garry W.; King, Kirsten L.; Hea, Roland C.; Allison, William Subject: RE: CENC 4 and 5 - fuel switching question from Laurel



### Laurel,

Yes, there is supporting documentation in the docket. The attached documents were originally provided to EPA (as well as the FWS and NPS) by Curt Taipale on August 23, 2010. Fuel switching to Natural Gas is mentioned on page 17 of the Technical Support Document (TSD) for CENC. The State conducted a preliminary analysis as described below and concluded that a complete fuel switch to natural gas for Units 4 and 5 was cost prohibitive, as is the case with Unit 3 at the same facility and also with other Colorado EGUs (such as PRPA Rawhide Unit 1). It should be noted that the cost is variable depending on the unit. While it is unfortunate that this conclusion is not further described in the TSD, all available technologies, including technically feasible alternative fuel technologies, were properly examined within the scope of the five-factor analysis.

The flexible BART limit established in the SIP may be accomplished through partial fuel switching and other operational changes to reduce emissions (see docket EPA-R08-OAR-2011-0770-0002.pdf page 260 and EPA-R08-OAR-2011-0770-0008.pdf page 259). These changes will also result in reduced SO2 and PM10 emissions. CENC itself notes in the docket that fuel switching to natural gas was examined at both units (EPA-R08-OAR-2011-0770-0002.pdf page 264 and EPA-R08-OAR-2011-0770-0008.pdf page 262).

Thank you, Lisa

Lisa Clarke, M.S./P.E. Air Quality Planner/Engineer Planning & Policy Program Air Pollution Control Division Colorado Department of Public Health and Environment 4300 Cherry Creek Drive South Denver, CO 80246-1530 303-692-3117| lisa

. clarke @ state

. co

. usFrom: Laurel Dygowski [mailto:Dygowski.Laurel@epamail.epa.gov]

Sent: Monday, July 02, 2012 3:37 PM To: Clarke, Lisa M. Cc: Taipale , Curtis D.; Kaufman, Garry W.; King, Kirsten L.; Hea, Roland C.; Allison, William Subject: RE: CENC 4 and 5 - fuel switching question from Laurel

Was the information in the attachments included as part of the State's submittal? I do not see fuel switching discussed in the five factor analysis or SIP, so need to see what is actually in the record pertaining to this. Thanks

  Note - New Mailing Address

Laurel Dygowski Regional Haze Coordinator Air Quality Planning Unit US EPA - Region 8 1595 Wynkoop Street Denver, CO 80202-1129 303-312-6144

"Clarke, Lisa M." ---06/25/2012 09:24:54 AM---Hi La urel, I reviewed the comment below and here is the Division’s response:

From: "Clarke, Lisa M." <Lisa.Clarke@dphe.state.co.us> To: Laurel Dygowski/R8/USEPA/US@EPA Cc: "King, Kirsten L." <Kirsten.King@dphe.state.co.us>, "Hea, Roland C." <Roland.Hea@dphe.state.co.us>, " Allison , William" <William. Allison @dphe.state.co.us>, "Kaufman, Garry W." <Garry.Kauf man@dphe.state.co.us>, "Taipale, Curtis D." <Curtis.Taipale@dphe.state.co.us> Date: 06/25/2012 09:24 AM Subject: RE: CENC 4 and 5 - fuel switching question from Lau rel

Hi Laurel,

I reviewed the comment below and here is the Division’s response:

In determining BART for CENC Units 4 and 5, the State analyzed alternative fuel-switching scenarios. The State requested in a letter dated January 26, 2010 (attached) to CENC that fuel-switching needed to be examined. CENC responded in full on February 8, 2010 (also attached). The State subsequently examined fuel-switching to a number of different fuels. Boilers 4 and 5 are not capable of burning wood or other biomass types. The use of sludge as the primary fuel is not technically feasible due to handling and storage issues and has not been researched for potential pollutant reductions. Residual oil, distallate oil, ethanol, and natural gas, were reviewed as technically feasible options.

Residual oil would not result in pollutant reductions. Distillate oil, ethanol, and biodiesel, are extremely high cost fuels for boilers of this size, with prices 2-3 times the cost of natural gas, 6-7 times higher than coal (at the time of analysis – December 2009) and highly volatile. Using EPA’s Cost Control Manual, the State determined that the cost of fuel-switching to natural gas for Boilers 4 and 5 when combined with direct and indirect installation costs, isgreater than $ 25
, 000 per ton of NOx reduced annually

. A study may be needed to assess potential pipeline

changes that may need to occur to account for the increased natural gas demand which could increase costs.

Therefore, based on the information above, the State determined that “although other alternatives achieve better emissions reductions, achieving lower limits through different controls was determined to not be reasonable based on the high cost/effectiveness ratios coupled with the low visibility improvements afforded.”

Please let me know if you have any further questions or comments.

Thanks,
Lisa

Lisa Clarke, M.S./P.E. Air Quality Planner/Engineer Planning & Policy Program
Air Pollution Control Division Colorado Department of Public Health and Environment 4300 Cherry Creek Drive South Denver, CO 80246-1530 303-692-3117| lisa

. clarke @ state

. co

. us

From: Laurel Dygowski [ mailto : Dygowski

. Laurel @ epamail

. epa

. gov ] Sent: Thursday , June 21, 2012 7:39 AM To: Taipale , Curtis D. Subject: CENC 4 and 5

Hi Curt -

We have gone through all the Colorado comments and there is one more we need your help on pertaining to CENC 4 and 5 (see below). Aaron looked at this a nd does not see a good technical reason the State ( or EPA) did not assess fuel switching. Any thoughts?



### Comment: In determining BART for Units 4 and 5, the State fa iled to identify and analyze alternative fueling scenarios that would lead to gr eater reductions in NOx, sulfur dioxide (“SO
2 

### ”), and particulate matter. The proposed rule notes, an d the underlying record clearly explains, that Units 4 and 5 are capable of burning (and do in fac t burn) fuels other than coal. In particular, the

### proposed rule states that Unit 4 can and does burn natural gas or fuel oil and that Unit 5 can and

does burn fuel oil. Both boilers may fire ethanol o r sludge from the Coors Brewery. Despite this, the State did not assess whether alte rnative fueling scenarios, such as a full or partial shift from coal to natural gas or fuel oil at Units 4 and 5 would represent BART. This is a concern because according to the CAA Title V Operat ing Permit for the facility, both Units 4 and 5 could meet stronger SO
2 

### and NOx emission rates than have been proposed by t he State as BART. The operating permit shows that the permitted emission rates for Units 4 and 5, when firing natural gas and/or fuel oil, are already low er than the proposed BART emission rates. See Colorado Department of Public Health and Environmen t, Operating Permit, Trigen-Colorado Energy Corpora tion Golden Facility (Feb. 1, 2003). Attached as Exhibit 1 to the comment. 

### Given that permitted emission rates are higher than actual emissions, this means that t he facility is most likely capable of achieving far greater emission reductions under an alternativ e fueling scenario. Indeed for Unit 4, whether firing natural gas or fuel oil, both permitted SO
2 

### and NOx emission rates are lower than the proposed BART limits. For Unit 5, when firing fuel oil, the permitted SO
2 

### emission rate is lower than proposed BART. Furthermore, although the permi tted NOx emission rate for Unit 5 when firing fuel oil is higher than the proposed BART, i t is based on a 3-hour average (as opposed to a 30-day average) and even then, actual emission are likely to be lower than the proposed BART Here, alternative fueling scenarios, such as a full or partial shift away from coal to fuels that are already being burned in Units 4 and 5 (including na tural gas and fuel oil) both seem to represent the “best system of continuous emission c ontrol technology” and seem entirely reasonable when considering the five factors requir ed to be assessed by states when determining BART. The State failed to analyze alternative fueli ng in its SIP. Alternative fueling is an available technology that should have been analyzed by the State given that the visibility benefits to Class I areas could be tremendous. Although the State purported to identify “all available technologies” in its BART analysis, clearly it did not identify all available technologies. The failure to analyze alternative fueling scenario s is especially confusing because the State did, apparently, identify in their TSD fo r the CENC facility a fuel switch to natural gas as an available technology and in analyzing “SO
2 

### Emissions Management” as potential BART, noted that an option to reduce emissions could invo lve a “dispatch [of] natural gas-fired capacity.” There is, however, no explanation in the TSD as to why “fuel switching,” or otherwise increased reliance on natural gas, would not consti tute BART or would be contrary to the five factors required to be considered in establishing B ART under the CAA. The failure to analyze alternative fueling scenario s is further confusing because the EPA’s BART guidelines indicate that alternative fue ling scenarios should be analyzed by states when determining BART. The guidelines specifically state that “potentially applicable retrofit control alternatives” can include the “use of inher ently lower-emitting processes/practices” or “combinations of inherently lower-emitting processe s and add-on controls.” Appendix Y at Section IV.D.3. Above all, states should “identify potentially applicable retrofit technologies that represent the full range of demonstrated alternativ es.” Id. The guidelines clearly indicate that inherently “lower-emitting processes,” such as alte rnative fueling, are squarely within the realm of what may be considered BART.

** ** Note - New Mailing AddressLaurel Dygowski

Regional Haze Coordinator Air Quality Planning Unit US EPA - Region 8 1595 Wynkoop Street Denver, CO 80202-1129 303-312-6144 

### (See attached file: CEN 4- Factor Questions

. pdf )( See attached file: February 8

,

2010 CENC Response to CDPHE. pdf ) CEN BART Cost Analysis 19 July 2010.xlsx