NAVAJO GENERATING STATION P O . Box 850 Pa ge, A Z 8604 0 ( 928 ) 645-62 17 F ax ( 928) 645-7298



### May 1 , 2015 Mr. Gerardo Rios

### fR!ECIE~\?'lE!D 

## MAY 1 2 2015



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U.S. Environmental Protection Agency, Region IX 75 Hawthorne Street Mail Code : AIR-3 San Francisco , California 94105 

### Re: Administrative Permit Revision Application Navajo Generating Station PSD Permit Number AZ 08-0JA Dear Mr. Rios: ROBERT K . TALBOT

Manager



### The Navajo Generating Station (NGS) is a pulverized coal steam electric generating facility that is operated by the Salt River Project Agricultural Improvement and Power District (SRP). NGS currently operates under Title V permit number NN -ROP 05-06 issued by the Navajo Nation Environmental Protection Agency (NNEPA) . Additionally , NGS has been issued Prevention of Significant D eteriorati on (PSD) permit number AZ 08-0lA by United States Environmental Protection Agency ' s (EPA) Region 9 . On March 31 , 2015 , SRP submitted to NNEPA and EPA an addendum to it Title V permit renewal applicati on to incorporate th e applicable mercury (Hg) provisions of the Mercury and Air Toxics Standard (MATS) Rule and to au t horize the Hg control equipment necessary fo r complying with the MATS Hg emission limits. On April 20 , 2015 , SRP had been n otified by EPA that the new Hg control equipment to be installed is subject to the administrative permit revision requirements under 40 CFR §49.159(f) 1 • 

### As a result, SRP is submitting thi s administrative permit revision app li cation under the direction of EPA to authorize the Hg control equipment. Description of Change

1 Per telephone conversation between Lisa Beckham , EPA Region 9, and Kyle Hecke l , SRP on April 2 0 , 2015.The proposed Hg control s ystem will consist of a new c alcium bromide application system and a new powdered activated carbon (PAC) injection system. Details of each system are described below: Calcium Bromide A ppli cation System The calcium bromide app lic ation system will consist of one main 60,000 gallon storage tank , three 4 , 500 gallo n day tanks, and several pumping skids for transferring the calcium bromide . Liquid calci um bromide will be truck delivered into the main storage tank . The calcium bromi de will be transferred to each unit's day tank via dedicated transfer pumps. From the d ay tanks , calcium bromide will applied to the coal directly at each ex i ting coal pulverizer feeder . No air emissions are anticipated from the calcium bromide app li c ation system. PAC Injection System The PAC injection system will consist of two 40 ton storage si l os , each equipped with a baghouse , two feed tanks containing PAC slurry , and various pumping skids for transferring the PAC slurry. PAC will be truck de liv ered into the main storage si lo s for bulk storage . From the storage silos , the PAC will be mixed with water creating a PAC slu rry and subsequ ently transferred to the feed tank . PA C s lurry will then be fed to each absorber as needed. P articulate matter emissions are anticipated from the unloading of PAC into the storage si lo s. 

### Potential Emissions The proposed PAC storage si lo dust collectors are anticipated to be sources of particulate matter (PM , PM 10 , and PM 2 5 ) emissio n s . Using the man ufacture's design flow rate and particu l ate grain lo ading rate for the baghouses and assuming 8 , 760 hours of operation per year , the total potential emissions from the pro j ect are estimated to be 0.08 tons per year for PM , 

### PMw and PM 2 .s . Detailed emiss io n calcul ations and the manufacture ' s specification sheet for the b a ghouses are attached. 

### If you h ave any ques tio ns regarding this application submittal , please contact Kyle Heckel at (602) 236 - 5493 or me at (928) 645-6217 . Sincerely ,**~**

# ~;{! Robert Talbot, Manager Navajo Generating Sta tioncc w/attachment: Stephen B. Etsitty , NNEPA Paul Ostapuk , NGS LOC 6 - 2-6Table 1: p, . I E . . f1 Dust Co ll 

### s Description Co ntro l F low Rate PM EF 1 PM 10 EF 1 P M 2 .s EF 1 PM Emi ss io n s PM 10 E mi ss ions PM 2 .5 E mi ss io n s Device (a c fm) (g r/act) ( 2 r/ac O (l! r/a cf ) llb/ hd (tons/yr) 3 (lb / hd (ton st vd (lb / h d (tons/ vr) 3 PAC S tora ge Silo A B ag ho use 1 ,200 8 . 8 0E-04 8 . 8 0E - 04 8 . 8 0E - 04 0 . 00 9 1 0.040 0 . 009 1 0.040 0 .00 9 1 0.0 3 9 6 PAC Storage Silo B B ag ho us e 1 ,2 0 0 8 . 8 0E -04 8 . 8 0E-04 8.8 0E- 04 0 . 00 9 1 0 . 040 0 . 0 0 9 1 0.040 0.009 1 0 . 0 39 6 Total Emissions fro m Du st Co llection Sys tem s 0.02 0.08 0.02 0 . 08 0.02 0.08 l ) Em iss ion fact o rs ba sed o n manufac turers' data ( see Attac hme nt). 2) Emi ss ion s ( lb/hr )= F l ow Rat e (ac fm) x Emi ss io n Fac to r (gr/a ct) x ( lb/7 ,000 gra in) x (60 min/hr) 3) Emi ss io ns (to n s/yr) = Em is s io ns (lb/hr) x 8 ,7 60 h r/yr x ( l to n/2 , 000 lb)

# • CHEMCO Equipment Company 15 0 0 In dustria l Drive Monongahela, PA 15 0 63 

# - - CH E MCO •Te le. : (724) 258-7333 •Fax . : (724 ) 258-7350 EQUIPMENT •e-ma il : sa les@chemcoequ ipment.com 

### February 16, 2007

RE : Dust Collector Emission Information Below is the requested for information on the dust collector. We are proposing t o furnish a CHEMCO Model CEC-DC300 dust collector with the following design specifications: • Filter Area: 300 Square Feet • Fi lter Media: Pleated polyester • Blow In Rate: 750 SCFM • Fill Cycle Duration: 60-90 Minutes per Fill Cycle • Cloth Load i ng : 2 . 5 SCFM/Square Feet • Fan Capacity : 1200 SCFM 

### @ 5" W.C . • Outlet Emissions: .00088 Grains/CF (2mg / M 3 ) 

### • Efficiency: 99.9% Based upon an inlet loading of 20 grains/cubic foot If you need additiona l information on the dust collector for your air perm it application , p lease advise. Sincerely , CHEMCO Jeffrey A. 

### Tennant

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