SJATEOFCALIFORNIA -THE RESOURCES AGENC- ARNOLDSCHWARZENEGGER,**Gov~nor** 

## ============ CALIFORNIA ENERGY COMMISSION

1516 NINTH STREET SACRAMENTO, CA 95814-5512 

# RECEIVED

NOV . 1 2007

October 26,2007 Permits 0lhl:eAir-3 U.S. EPA, Region 9 Ms. Deborah Jordan, Director USEPA, Region 9 Air Programs Division 75 Hawthorne Street San Francisco, CA 94105

Dear Ms. Jordan:

REQUEST FOR USEPA CONCURRENCE REGARDING TWO AIR QUALITY AMENDMENT REQUESTS

- HIGH DESERT POWER PRO

..IECT (97-AFC-1C)

The purpose ofthis letter is to request yourconcurrence with one approved and one proposed amendmentto the airquality conditions ofcertification forthe High Desert Power Project (HDPP). Energy Commission staff have been working with Gerardo Rios and his stafffor several months to obtain concurrence with these proposed changes.

Thefirst amendmentwas approved by the Energy Commission on October 20, 2004, eliminating durational limits on startups while leaving all emission limits unchanged. This modification was also approved by the Mojave DesertAirQuality Management District (MDAQMD). The reason forapproving the amendment is that Energy Commission and MDAQMD staff determined that this would allow HDPP to**~tartup** theirturbines sequentially in orderto minimize thermal stress on both the combustion turbines and the steam turbine generatorwhile maintaining emissions at or belowthe pre-existing limits. The end result is improved plant reliability with no negative environmental consequences.

The second amendment petition from HDPP is dated August 30, 2006. This petition requests that the interval for source testing for nitrous oxide (NOx) and carbon monoxide (CO) be extended from every yearto everyfive years, and other changes not covered in the Prevention ofSignificant Deterioration (PSD) permit. The reason forthis request is that HDPP believes that the eXisting Continuous Emissions Monitoring System (CEMS), in combination with an annual Relative Accuracy TestAudit (RATA) ofthe CEMS is reliable and is sufficient to ensure thatthe facility will remain within its emission limits forthese pollutants. The second amendment petition also requests othertechnical changes, including correction ofa typographical error in the drafting ofcondition AQ-30 in the October 20, 2004 amendment Orderthat erroneously placed limits on the power block instead ofindividual equipment. This change was not intentional.

MDAQMD has already incorporated these changes in the HDPP Title V Permit undertheir delegated authority. Although we were informed by your staff in a conversation on June 20, 2007, that corresponding approval ofthese changes in HDPP's PSD permit would be forthcoming in the nearfuture, atthis time it has notyet occurred. We understand that you have had some staffturnover, and your office has a full agenda of project applications and other matters. However, given the prolonged period oftime the HDPP requests have been under review, we ask you to place a higher priority on the processing ofthese requested changes. Without the PSD permit changes, HDPP cannot implementthese modifications.Ms. Deborah Jordan October26, 2007 Page 2

Ifyou have any questions or need additional information, you may contact me at (916) 654­ 3933, oryour staff may contact Tuan Ngo ofthe Energy Commission air quality staff at (916) 654-3852, or Compliance Project Manager Steve Munro at (916) 654-3936. I appreciate your assistance with this matter.
Sincerely,

TERRENCE O'BRIEN Deputy Directorfor Energy Facilities Siting

cc: Jon Boyer, High Desert Power Project, LLC