Xcel Energy·M 

September 1, 2015 

Joe Kordzi 

EPA's South Central Region (Region 6) 

Air Planning Section (6PD-L) 

Environmental Protection Agency 

1445 Ross A venue 

Suite 1200 

Dallas, Texas 75202-2733 

Docket No. EPA-R06-0AR-2014-0754 

Re: Proposed Approval/Disapproval of Texas and Oklahoma Regional Haze State 

Implementation Plans; Federal Implementation Plan for Regional Haze 

Dear Mr. Kordzi: 

Southwestern Public Service Company ("SPS") d/b/a Xcel Energy ("Xcel Energy") respectfully 

submits the following response to your electronic mail request dated August 29, 2015 regarding 

additional information in regard to water availability at Tolk Station. 

As stated in our initial comments dated April20, 2015 and our August 20, 2015 response to your 

information request dated August 11, 2015, we estimate the addition of dry scrubbers at Tolk would 

increase water demand at the facility by 380 million gallons of water annually or 1,165 acre/feet per 

year. Over 30 years, as amortized by EPA in its proposal, additional water requirements would be 

approximately 36,000 acre-feet for operation of the dry scrubbers. 

This estimate is the incremental additional water that would be required to operate dry scrubbers. 

This estimate already assumes (i.e.- was reduced by) our expectation that we could reuse approximately 

70% of the cunent blowdown water in dry scrubbers. The cost of procuring additional water resources 

was not factored into EPA's analysis of whether scrubbers can be justified at Tolk. The additional water 

and infrastructure is a significant expense, if the water is available for acquisition, and was not included 

in EPA's cost estimate. 

As also stated in our April20, 2015 initial comments, Tolk uses blowdown from its neighboring 

Xcel Energy facility, Plant X, to conserve water by recycling it at Tolk. This requires additional 

clarifying capacity at the Tolk facility which enhances the treatment facilities and allows improved 

water reuse at Tolle The repetitive cycling of the water used in the circulating cooling water system 

changes the water chemistry and requires that an amount of water (blow down) be eliminated from the 

system and fresh water added to maintain proper chemistry balance in the circulating water system. 

Cunently the blow down rate of the circulating water system is 300-350 GPM, cannot be used by other 
Mr. Joe Kordzi 2 September 1, 2015 

plant systems and is discharged to the evaporation ponds. An FGD scrubber would allow for 

approximately 70% of the current blowdown to be reused which would require the remaining (30%) to 

still be discharged. 

There is no blowdown water available that was not already factored into our estimate of the 

additional water that would be required for the operation of dry scrubbers. Therefore, additional water 

capacity in the amount of 1,165 acre-feet per year is required. All available water sources and 

blowdown are used in the system in an effort to conserve water in this very arid region. 

Xcel Energy appreciates EPA's consideration of this response to EPA's information request in 

its efforts to finalize the rule. Additionally, Xcel Energy formally requests this response be placed in 

Docket No. EPA-R06-0AR-2014-0754. If you should have any questions, please contact me at 303-

571-2762 or Ann Seha at 612-215-4619. 

Very truly yours, 

JeffWest 

ra~ C_ 

Director, Environmental Services -~ 

Xcel Energy Inc.