### ,
March 19, 2012

Mr. Gerardo Rios Chief, Permits Office U.S. EPA Region 9 75 Hawthorne Street San Francisco, CA 94105

Subject: Pio Pico Energy Ce nter PSD Permit Application Response to EPA Supplemental Information Request

Dear Mr. Rios:

As requested by EPA on March 8, 2012 1 

### , we are submitting this additional information on behalf of Applicant.

Applicant submitted the PSD permit application on April 1, 2011. The original PSD permit application included a visi bility screenin g analysis.

Following guidance from Federal Land Managers (FLMs) 2 

### on assessing visibility impacts, the PSD application included the determination that the project would have no significant adverse impact on Class I areas. 3



### In the PSD permit application, Applicant also prepared a visibility analysis for the two Class II areas within 50 km of the project. This analysis was prepared following EPA procedures for evaluating the potential fo r visibility impairment on Class I areas. 4 

### This procedure involves a series of screening analyses of incr easing complexity. Based on EPA guidance 5 

### , if the results of the Level 1 screening analysis are below the screening threshold, no further anal ysis is required.

The Class I threshold is the level at which th e FLM is likely not to object to the issuance of the PSD permit based on near field visibility impacts to a Class I area 6 

### . EPA has not yet established quantitative visi bility thresholds for Class II areas. Consequently, in the PSD permit application, Applicant proposed to use a Class II threshold that was

1 Email from Cleveland Holladay to Steve Hill, March 8, 2012.

2 U.S. Forest Service et al., “F ederal Land Managers’ Air Quality Related Values Work Group (FLAG), Phase I Report—Revised (2010),” October 2010, p. 18
3 Resubmitted PSD Application, p. PSD-4.57

4 U.S. EPA, Workbook for Plume Visual Impact Screening and Analysis (Revised), EPA-454/R-92-023, October 1992
5 U.S. EPA, Workbook for Plume Visual Impact Screening and Analysis (Revised), EPA-454/R-92-023, October 1992, p. 1
6 U.S. EPA, Workbook for Plume Visual Impact Screening and Analysis (Revised), EPA-454/R-92-023, October 1992, p. 1 

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### Gerardo Rios -2- March 19, 2012

extrapolated from the Class I thresh olds using the ratio of Class II PM 10 

### increment to Class I PM 10 

### increment. A threshold less-stringent than the Class I area threshold for triggering the much more complex Level 2 an alysis was proposed for the Class II area analysis because (a) there is a distinction be tween the degrees of pr otection applicable to Class I and Class II areas; (b) Class I areas can be protected through AQRV analysis, whereas protection of Class II areas can be achieved using BACT requirements; and (c) the results of the Class II visibility anal ysis are for informational, not regulatory,
purposes.

As shown in the PSD application, the results of the Level 1 screening analysis exceeded the Class I threshold, but were below the pr oposed Class II thresh old. On March 8, 2012, more than 11 months after the original analysis was submitted to EPA, Region 9 staff has requested a Level 2 screening analysis for Class II areas, despite the fact that EPA has not yet established significance thresholds for such an analysis.

The results of the requested Level 2 screen ing analysis are presented for Cleveland National Forest and Cabrillo National Monument in Tables 1 and 2 below, respectively. Tables 1 and 2 show that the maximum visual impacts inside these two Class II areas are below the Class I significance criteria. Visu al impacts outside the Class II areas are “integral vistas” that are not protected. 7 

### Consequently, per EPA guidance, 8 

### the VISCREEN results for plume parcels outside the Class II area are ignored. Because the visual impacts inside the Class II areas are below the significance criteria, this completes the visibility analysis. 9

7 National Park Service, Visibility Protection http://www.nature.nps.gov/air/regs/visibility.cfm (accessed 3/14/2012)
8 U.S. EPA, Workbook for Plume Visual Impact Screening and Analysis (Revised), EPA-454/R-92-023, October 1992, p. 27
9 U.S. EPA, Workbook for Plume Visual Impact Screening and Analysis (Revised), EPA-454/R-92-023, October 1992, p. 1

### Gerardo Rios -3- March 19, 2012

TABLE 1 PPEC IMPACTS ON VISIBILITY IN CLEVELAND NATIO NAL FOREST (LEVEL 2 SCREENING ANALYSIS)

Background Ozone:0.04 ppm Emission Density Diameter Background Visual Range: 95 km b Particulate: 2.08 g/s 2.5 1 Source-Observer Distance: 23 km NOx: 4.54 g/s
Min. Source-Class II Distanc e: 23 km Primary NO2 0.00 g/s Max. Source-Class II Distance: 50 km Soot 0.00 g/s 2.0 1 Plume-source-observer angle: 11.25 degrees Sulfate 0.00 g/s 1.5 4 Stability: 6 Wind Speed: 2.00 m/s Maximum Visual Impacts INSIDE Class II Area a
Delta E Contrast

Background Theta Azi Dist Alpha Class I Criterion Plume Class I Criterion Plume Sky 10 145 32.8 24 2.0 0.642 0.05 -0.005 Sky 140 145 32.8 24 2.0 0.458 0.05 -0.003
Terrain 10 159 50 9 2.0 0.703 0.05 0.008
Terrain 140 159 50 9 2.0 0.314 0.05 0.009 Maximum Visual Impacts OUTSIDE Class II Area a,c
Delta E Contrast

Background Theta Azi Dist Alpha Class I Criterion Plume Class I Criterion Plume Sky 10 1 1 168 N/A 1.581 N/A -0.025 Sky 140 1 1 168 N/A 1.346 N/A -0.011 Terrain 10 1 1 168 N/A 3.247 N/A 0.038 Terrain 140 1 1 168 N/A 1.449 N/A 0.043

a Impacts based on 4 startups and 4 shutdowns of each turbine in a single day, remainder of day at peak operation.

b National Park Service, Visibility Monitoring Data, http://www.nature.nps.g ov/air/monitori ng/vismon.cfm#data (accessed 3/17/2011)

c VISCREEN results for plume parcels outside the Class II area are ignored.

### Gerardo Rios -4- March 19, 2012

TABLE 2 PPEC IMPACTS ON VISIBILITY IN CABRILLO NATIONAL MONUMENT (LEVEL 2 SCREENING ANALYSIS)

Background Ozone: 0.04 ppm Emission Density Diameter Background Visual Range: 95 km b Particulate: 2.08 g/s 2.5 1 Source-Observer Distance: 32 km NOx: 4.54 g/s
Min. Source-Class II Distanc e: 32 km Primary NO2 0.00 g/s Max. Source-Class II Distance: 33 km Soot 0.00 g/s 2.0 1 Plume-source-observer angle: 11.25 degrees Sulfate 0.00 g/s 1.5 4 Stability: 6 Wind Speed: 2.00 m/s Maximum Visual Impacts INSIDE Class II Area a
Delta E Contrast

Background Theta Azi Dist Alpha Class I Criterion Plume Class I Criterion Plume Sky 10 93 33 75 2.0 0.379 0.05 -0.003 Sky 140 93 33 75 2.0 0.264 0.05 -0.002
Terrain 10 84 32 84 2.0 0.303 0.05 0.002
Terrain 140 84 32 84 2.0 0.117 0.05 0.003 Maximum Visual Impacts OUTSIDE Class II Area a,c
Delta E Contrast

Background Theta Azi Dist Alpha Class I Criterion Plume Class I Criterion Plume Sky 10 0 1 168 N/A 1.027 N/A -0.018 Sky 140 0 1 168 N/A 0.729 N/A -0.008
Terrain 10 0 1 168 N/A 2.030 N/A 0.028
Terrain 140 0 1 168 N/A 0.884 N/A 0.031

a Impacts based on 4 startups and 4 shutdowns of each turbine in a single day, remainder of day at peak operation.

b National Park Service, Visibility Monitoring Data, http://www.nature.nps.g ov/air/monitori ng/vismon.cfm#data (accessed 3/17/2011)

c VISCREEN results for plume parcels outside the Class II area are ignored.



### As requested by EPA, the above analysis is submitted only for informational purposes.

Please do not hesitate to call me if you have any questions.

Sincerely,

Steve Hill

cc: John McKinsey, Stoel Rives LLP David Jenkins, Apex Power Group Steve Moore, SDAPCD