Hi Anita,

As I mentioned in my previous note, we have been di scussing options for obtaining additional certainty regarding the potential performance of SNCR at NGS. After a great deal of consideration, we have deci ded to proceed with a demonstration test for SNCR at NGS, despite that the cost of urea has increased substan tially

over the last several months.

The previous work that was done by Fuel Tech that f ormed the basis for the NOx emission rate range in the January 2012 BART report (0.15-0.18 lb/MMBtu) was p rimarily theoretical. We expect that the demonstra tion test will provide greater certainty regarding the p otential performance of SNCR at NGS.

We expect to be able to provide the results of the test to EPA sometime in the next several weeks. In the meantime, if you have any questions or would like t o discuss further, please let me know.

Thanks,

Grant

From: Anita Lee [ mailto:Lee.Anita@epamail.epa.gov ]
Sent: Wednesday, April 18, 2012 1:02 PM

To: Smedley Grant M
Cc: Colleen McKaughan Subject: Re: Voicemail



### RE: Voicemail Smedley Grant M

to: Anita Lee
04/25/2012 03:37 PM
Cc: Colleen McKaughan, Barr Kelly J
Hide Details From: Smedley Grant M <Grant.Smedley@srpnet.com>

To: Anita Lee/R9/USEPA/US@EPA

Cc: Colleen McKaughan/R9/USEPA/US@EPA, Barr Kelly J <Kelly.Barr@srpnet.com>

History: This message has been forwarded. Page 1 of 3

5/17/2012 file://C:\Documents and Settings\ALEE07\Local Setti ngs\Temp\notesBAAA25\~web5683.

...Hi Grant,

Thank you for your email response to our SNCR quest ion. We understand from your email that you cannot provide specific information on the emission rate y ou expect would be achievable with SNCR.

The most recent information we have is that SRP use d a range of 0.15-0.18 lb/MMBtu for cost effectiven ess calculations and modeling based on "information tha t FTI has provided to date". For our record, can yo ur provide the FTI information they provided SRP "to date" (as of January 2012) to support the 0.15-0.18 lb/MMBtu range?

Thanks again, and please feel free to call if you h ave any questions or concerns!

anita

- - - - - - - - - Anita Lee, PhD

Environmental Scientist US EPA, Region 9, Air Planning Office 75 Hawthorne Street (AIR-2)

San Francisco, CA 94105

ph: (415) 972-3958 fax: (415) 947-3579

From: Smedley Grant M <Grant.Smedley@srpnet.com>

To: Anita Lee/R9/USEPA/US@EPA

Date: 04/13/2012 07:12 AM

Subject: Voicemail

Hi Anita,

I wanted to follow up with you on your voicemail me ssage. You referenced the nitrogen oxide (NOx) emi ssion rate range of 0.15-0.18 lb/MMBtu that we specified for Selective Non-Catalytic Reduction (SNCR) in our January 2012 Best Available Retrofit Technology (BART) report for Navajo Genera ting Station, and asked whether we could be more sp ecific about the emission rate that might be achievable. You specif ically asked whether the Computational Fluid Dynami cs (CFD) modeling

that Fuel Tech conducted would allow us to more acc urately define the NOx emission rate that might be achievable in
practice.

The CFD modeling provides some preliminary informat ion that would be utilized in designing an SNCR ins tallation (e.g., where to position injectors) and some indication of potential performance. Unfortunately, the CFD modeling does not in
any way guarantee that an emission rate in that ran ge would be achievable in practice.

We are discussing options for obtaining additional certainty regarding the potential performance of SN CR, but at this point,
we cannot provide more specific information on the emission rate that would be achievable in practice.

If you have any questions or would like to discuss further, please let me know. 

### Page 2 of 3

5/17/2012 file://C:\Documents and Settings\ALEE07\Local Setti ngs\Temp\notesBAAA25\~web5683.

...Thanks,

Grant

--------------------------------------------------- ------ Grant Smedley
Manager, Environmental Policy & Innovation
Salt River Project
Tel: (602) 236-2928
Fax: (602) 236-6690
grant.smedley@srpnet.com

--------------------------------------------------- ------ 

### Page 3 of 3

5/17/2012 file://C:\Documents and Settings\ALEE07\Local Setti ngs\Temp\notesBAAA25\~web5683.

...