# XcelEnergy·M

September 1, 2015 Joe Kordzi EPA's South Central Region (Region 6) Air Planning Section (6PD-L) EnvironmentalProtectionAgency 1445 Ross Avenue Suite 1200 Dallas, Texas 75202-2733 DocketNo. EPA-R06-0AR-2014-0754 Re: Proposed Approval/Disapproval ofTexas and OklahomaRegional Haze State ImplementationPlans; Federal ImplementationPlanfor Regional Haze DearMr. 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 informationinregardto water availability at Tolk Station.
As statedin 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 ofwater 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 ofthe dry scrubbers. This estimate is the incremental additional water that would be requiredto operate dry scrubbers. This estimate already assumes (i.e.- was reduced by) our expectationthat we could reuse approximately 70% ofthe cunent blowdown water in dry scrubbers. The cost ofprocuring additional water resources was not factored into EPA's analysis ofwhether scrubbers canbejustified at Tolk. The additional water and infrastructure is a significant expense, ifthe water is available for acquisition, and was not included inEPA's cost estimate. As also stated in our April20, 2015 initial comments, Tolkuses 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 ofthe water used in the circulating cooling water system changes the water chemistry and requires that an amount ofwater (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 ofthe circulating water system is 300-350 GPM, cannot be used by otherMr. Joe Kordzi 2 September 1, 2015 plant systems and is discharged to the evaporation ponds. An FGD scrubber would allow for approximately 70% ofthe current blowdown to be reused which would require the remaining (30%) to stillbe discharged. There is no blowdown water available that was not already factored into our estimate ofthe additional water that would be required for the operation ofdry 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 inthe systemin an effortto conserve water inthis very aridregion. Xcel Energy appreciates EPA'sconsideration ofthis response to EPA's informationrequest in its efforts to finalize the rule. Additionally, Xcel Energyformally requests this response be placed in DocketNo. EPA-R06-0AR-2014-0754. Ifyou shouldhave any questions, please contact me at 303- 571-2762 or Ann Seha at 612-215-4619. Verytruly yours,



# ra~ JeffWest 

# C_ Director, Environmental Services

**-~** Xcel Energy Inc.