AECOM 978.589.3000 tel 

2 Technology Park Drive 978.589.3100 fax 

Westford, MA 01886-3140 

Memorandum 

To enhance and sustain the world’s built, natural and social environments

To: Scott Bohning Page 1 

cc: Shirley Rivera 

Subject: Final Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analyses for Palmdale 

Hybrid Power Project 

From: 

Richard Hamel 

Date: March 30, 2011 

 

On December 14, 2010, EPA Region 9, AECOM, and Inland Energy dicussed the last remaining open 

issues related to the 1-hour NO2 modeling analysis for the Palmdale Hybrid Power Project (PHPP), which 

are summarized below. This memorandum provides all remaining requested information and analyses. 

As such, there are no open items remaining for the PSD modeling analyses for PHPP. 

The PHPP application was submitted two years ago and we have repeatedly provided updated 

information and analysis, as described below. This final memo resolves all outstanding data requests 

and analysis except for a greenhouse Best Available Control Technology (BACT) analysis, which will be 

provided soon. EPA has not indicated that any additional information or analysis are needed other than 

what is discussed in this memo. If you have any questions about this memorandum or the PHPP, please 

contact me at the contact information provided above. The City of Palmdale, Inland Energy and AECOM 

look forward to working with the EPA to complete the PHPP permitting process as expeditiously as 

possible. 

I. Overview of PSD Application History and Background 

As was summarized in a prior memo provided on December 14, 2010, AECOM, on behalf of the City of 

Palmdale, submitted a Prevention of Significant Deterioration (PSD) permit application to EPA Region 9

for the PHPP on April 1, 2009. Some additional information was provided in response to unofficial 

requests. However, it was not until a conference call between EPA and PHPP representatives in March 

2010 that supplemental information was requested by EPA on several items, including the PM2.5, 

visibility, and growth analyses, as well as the analysis with respect to the 1-hour NO2 National Ambient 

Air Quality Standard (NAAQS) that became effective in April 2010. On July 21, 2010, AECOM submitted 

the "Palmdale Hybrid Power Project (PHPP) - Supplemental Information for the Application for PSD 

Permit" in response to that conference call. 

Many emails, conference calls and submittals between EPA and the Applicant’s representatives have 

occurred since that time, all regarding the 1-hour NO2 NAAQS analysis. Most recently, a conference call 

between EPA Region 9, AECOM, and Inland Energy was held on December 14, 2010 to discuss the 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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status of open issues related to the 1-hour NO2 modeling analysis for the PHPP. The following personnel 

participated in the call: 

• Scott Bohning – EPA Region 9 

• Shirley Rivera – EPA Region 9 

• Julie Walters – EPA Region 9 

• Rich Hamel – AECOM 

• Sara Head – AECOM 

• Tom Barnett – Inland Energy, Inc. 

• Michael Carroll – Latham & Watkins, LLP 

On the call, the following issues and resolutions were reached, and the requested updated analysis is 

provided in this memorandum: 

1. Background Data Monitor: Use of the Lancaster Division Street Monitor for ambient background 

concentrations of NO2 was approved. 

2. Missing Ozone Data Fill-in: The methodology applied by AECOM to fill in missing ozone data 

was approved, though Scott Bohning of EPA requested some examples of the data filling. Those 

examples are included in this memo. 

3. Meteorological Data Duration: Based on information provided by AECOM to EPA on December 

14, 2010, EPA determined that the meteorological station at Palmdale Regional Airport was 

effectively site-specific, and therefore the use of three years of meteorological data was sufficient 

for this application. 

4. In-stack Ratio: EPA determined that AECOM had adequately researched the subject to the point 

where no further action was required by AECOM, and that EPA would follow up with General 

Electric. 

5. Time-Matched Background Data: EPA expressed concern over the use of hourly time-matched 

background and meteorological data as proposed by AECOM. Rather than extend this debate, 

AECOM now proposes to use the average 98th percentile background concentration over the 

most recent 3-years of available data. This value is more conservative than the background 

value suggested in the recently (March 2011) updated EPA NO2 NAAQS modeling guidance, 

which considers only the daily-maxima in the 98th percentile calculations. 

6. Source Inventory for Cumulative Analysis: AECOM has provided an updated analysis in this 

memo, following suggestions provided by EPA during the 12/14/10 call. While AECOM followed 

the approach suggested by EPA which included looking at sources beyond 50 kilometers (km) 

from the PHPP, the new guidance recommends only looking at sources within 10 km of the 

project site when determining the cumulative inventory. Hence, AECOM believes that the source 

inventory assessed is more than adequate to analyze sources that could cause a significant 

concentration gradient near the PHPP. 

In addition to the updated 1-hour NO2 NAAQS analysis, this memorandum includes updates to the 

modeling based on information received from the Antelope Valley Air Quality Management District 

(AVAQMD). Specifically, in December 2010, Chris Anderson of AVAQMD notified AECOM that the hourly 

emissions provided for sources at U. S. Air Force (USAF) Plant 42 near the proposed PHPP were 

mislabeled (emissions were labeled lb/hr but were actually in tons/hr). As a result, it was necessary to 

update the cumulative NAAQS modeling for both the 1-hour NO2 and 24-hour PM2.5 in support of the 

PHPP PSD Permit Application. The updated short-term modeling provides similar results (minor changes 

only) from prior submittals, continues to demonstrate that the PHPP will comply with all NAAQS, and 

hence did not change any of the prior conclusions. The annual emissions for both pollutants at USAF 

Plant 42 were correct and thus the annual modeling was not affected. 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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This memo summarizes the revisions to the NO2 and PM2.5 modeling due to both the changes in the NO2

background data and cumulative inventory, as well as to the increases in the USAF Plant 42 emissions 

used for the NO2 and PM2.5 cumulative analyses. This memo provides the updated modeling results for 

both the 1-hour NO2 and 24-hour PM2.5 analyses, discussing NO2 first and then PM2.5. Because the 

modeling adopts EPA’s recommended modeling approaches and/or is more conservative than recent 

guidance, and since the modeling shows compliance with the 1-hour NO2 and PM2.5 NAAQS, no further 

analyses should be required. 

II. Updated 1-hour NO2 NAAQS Modeling Analysis 

As noted above, the updated NO2 NAAQS Modeling Analysis presented herein addresses the remaining 

three of EPA’s requests: A) to provide examples of the ozone data fill-in procedures; B) to update the NO2

background values; and C) to consider additional sources for the cumulative source inventory. Also, this 

updated modeling includes corrected hourly emission rates and other refinements associated with the 

USAF Plant 42 sources. 

On March 1st, 2011, EPA issued additional guidance regarding the modeling of the 1-hour NO2 NAAQS1

. 

Although the modeling performed for this memo was completed prior to the issuance of the updated 

guidance, a review of the new information shows that the methodologies that form the basis of this 

revised modeling are at least as conservative as the approaches described in the guidance, and in some

cases are more conservative. As a result, AECOM’s opinion is that there is no need to revise the 

analyses presented herein with respect to that guidance. However, we have pointed out some of the 

applicable differences where appropriate. 

A. Example of Methodology Used in Filling Missing Ozone Data 

The proposed method for filling missing hourly ozone data, which was accepted by EPA during the 

conference call on 12/14/10, was described in the Response to EPA Additional Comments on AECOM’s 

1-hour NO2 NAAQS Analysis for Palmdale Hybrid Power Project, submitted by AECOM to EPA on 

12/14/10. Examples of the filling methodology used are provided below. As established in the earlier 

memo, the methodology used to fill missing ozone data was as follows: 

• Where only 1 or 2 hours of data were missing, the higher of the two endpoints was persisted 

across the missing hours. 

• Where 3 or more hours were missing, the higher of the following was persisted across all hours in 

the missing period: 

o The higher of the two endpoints, or; 

o The highest value from any hour in the missing period from the day before or after the 

day on which the missing hours occurred. 

In the 3 years of hourly ozone data (26,304 hours), there were 23 instances where 3 or more hours were

missing and the approach described in the 2nd bullet above was used to fill the missing data. Of those 23 

instances, 17 were blocks of less than 10 missing hours. Tables 1 and 2 provide examples of the two 

methods for data filling when 3 or more hours are missing. In Table 1, an example in which one of the

two missing endpoints was the highest value between either the endpoints or any of the hours matching 

the missing hours during the previous or next day is shown. In Table 2, an example in which one of the 

concurrent hours from the previous or next day was the highest ozone concentration is shown. The 

 

1

 http://www.epa.gov/ttn/scram/Additional_Clarifications_AppendixW_Hourly-NO2-NAAQS_FINAL_03-01-2011.pdf 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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spreadsheet PHPP Ozone Filling Analysis.xls containing all of the calculations used in filling the missing 

ozone data is included in Attachment A to this memo. 

In Table 1, ozone concentration data from 7/15/03 were missing from hours 10 through 13. Hours 9 and 

14 (the endpoints) from that day, along with hours 10 through 13 on the previous and next days were 

considered. In this case, hour 14 on 7/15/03, one of the endpoints, had the highest monitored ozone 

concentration of 104 ppb. Thus, the four missing hours were all filled with 104 ppb. 

Table 1: Example of Ozone Data Filling Where Endpoint is the Highest Value (ppb) 

Hour 

Previous 

Day 

Missing 

Day Next Day 

Filled 

Value 

9 64 55 74 N/A 

10 63 -9999 74 104 

11 62 -9999 74 104 

12 74 -9999 82 104 

13 84 -9999 82 104 

14 100 104 74 N/A 

In Table 2, ozone concentration data from 3/2/02 were missing for hours 10 through 18. Hours 9 and 19

(the endpoints) from that day, along with hours 10 through 18 on the previous and next days were 

considered. In this case, hours 14 and 15 on 3/1/02 had the highest monitored ozone concentrations, of 

48 ppb. Thus, all of the nine missing hours were filled with 48 ppb.

Table 2: Example of Ozone Data Filling Where Previous or Next Day Provides the Highest 

Value (ppb) 

Hour 

Previous 

Day 

Missing 

Day Next Day 

Filled 

Value 

9 10 5 36 N/A 

10 19 -9999 38 48 

11 30 -9999 41 48 

12 42 -9999 35 48 

13 42 -9999 37 48 

14 48 -9999 41 48 

15 48 -9999 36 48 

16 45 -9999 30 48 

17 44 -9999 26 48 

18 30 -9999 22 48 

19 10 35 22 N/A 

B. Ambient Background Concentration 

The prior NO2 NAAQS modeling submitted by AECOM for PHPP had paired the modeled concentrations 

with a background value that corresponded to the NO2 concentration measured in the same hour as the 

hourly meteorological conditions that produced the modeled result. EPA has indicated that it is 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

5

uncomfortable with the notion of time-matching ambient background concentrations with modeled 

concentrations on an hourly basis on the grounds that the practice may not be sufficiently conservative, 

and requested the use of a background that was based on a longer averaging time, related to the 

applicable meteorological conditions present at the project site. AECOM disagrees that the use of hourly 

time-matched background is inappropriate and again points out that the background concentration cannot

be more closely associated with the meteorological conditions that contribute to that background value

than using the actual meteorological conditions that were occurring during that specific hour. 

Nonetheless, AECOM researched the possibility of using values by season, month, or the average of 

hourly values for each of the 24 hours of the day for the ambient background, but found that none of 

these options worked in the analysis. The maximum NO2 concentrations that are measured at the 

Lancaster Division Street Monitor occur during the morning and evening commutes on almost a daily 

basis. As documented in the response to comment #2 in Response to EPA Additional Comments on 

AECOM 1-hour NO2 NAAQS Analysis for Palmdale Hybrid Power Project submitted on 12/14/10, the 

emissions that create these elevated background concentrations are not present at the project site and

thus the background concentrations recorded at the Division Street Monitor are overly conservative. 

Rather than attempt to define a longer period for the time-matched methodology for the application of 

background concentration, AECOM instead chose an approach tied directly to the form of the standard, 

i.e., the average of the 98th percentile over a 3-year period was used as the background concentration, as 

described in EPA’s Applicability of Appendix W Modeling Guidance for the 1-hour NO2 National Air 

Quality Standard (June 28, 2010). 

The March 1, 2011 EPA guidance memo, on page 17, indicated that a new 1st-tier assumption regarding 

background should be acceptable: 

“Based on these considerations, we believe that a less conservative “first tier” for a uniform 

monitored background contribution based on the monitored design value from a representative 

monitor should be acceptable in most cases. The monitored NO2 design value, i.e., the 98thpercentile of the annual distribution of daily maximum 1-hour values averaged across the most 

recent three years of monitored data, should be used irrespective of the meteorological data 

period used in the dispersion modeling.” 

The 3-year period selected for the PHPP modeling was the most recent three years where data are 

available (2007-2009) at the Lancaster station. This selection for a background value remains a 

conservative estimate of the background because the increased NO2 concentrations caused by commute 

traffic and trains in the vicinity of the monitor but far from the project site are still present, and the 98th

percentile background includes all hours, not just the daily maxima as described in the form of the 

standard and the recently updated modeling guidance. The resultant background value that was added 

to the modeled impacts, as shown in Table 3, is 77.1 μg/m3. The calculation of this value is shown in the 

spreadsheet Background Data Analysis.xlsx included in Attachment A. 

Table 3: Lancaster Division Street Monitor 1-hour NO2 Annual 98th Percentile 

Concentrations (μg/m3

) from 2007 – 2009 

2007 2008 2009 3-year Average 

80.88 77.12 73.36 77.1 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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C. Selection of Cumulative Non-Project Sources of NO2

During the conference call on 12/14/10, EPA requested further analysis of sources in the vicinity of PHPP 

to determine whether there were additional sources of NOx emissions in the region that could potentially 

cause a significant concentration gradient near PHPP. On 12/20/10, AECOM contacted Antelope Valley 

Air Quality Management District (AVAQMD) and requested an inventory of all permitted sources of NOx

emissions within 60 km of PHPP (note that the new EPA guidance issued on 3/1/11 suggests that only 

sources within 10 km need be considered for inclusion in the cumulative modeling). From that inventory, 

AECOM extracted all facilities with emissions greater than 20 tons per year (tpy) of NOx. The locations of 

these facilities relative to PHPP are shown in Figure 1. 

Also during the call, EPA recommended a “Q/D analysis” of sources in the region to screen out sources 

too distant to have an impact near PHPP based on their emission rates. A Q/D analysis is an approach 

used to quantify the source strength as a function of the amount of emissions from a source and the 

distance between that source and the project sources. This methodology determines if sources in the 

area are close enough to the project to have an impact on the modeling results. This screening is 

accomplished by creating a ratio of emissions to distance, and then determining whether each nonproject source is within the distance specified by the Q/D formula. If it is, the source is close enough to 

contribute to modeled concentrations near the proposed project. If not, the source is “screened out” and 

removed from consideration. Although EPA suggested that a Q/D analysis be used to screen non-project 

sources, no specific Q/D formula was provided or suggested by EPA. 

To the list of sources provided by AVAQMD, AECOM applied the Q/D “Screening Method for PSD” 

developed by the North Carolina Air Quality Section of the North Carolina Department of Natural 

Resources (NCDNR). A copy of the North Carolina letter which described this Q/D approach is included 

in Attachment B. This Q/D methodology uses the following formula to screen out sources that are not 

expected to contribute to the air concentrations near the subject of the modeling analysis: 

Q = 20D 

Where Q = the source’s maximum NOx emissions in tpy. 

The NCDNR letter defines D as the distance (in kilometers) from “the source in the screening area to the 

PSD source defining the impact area, for short term analysis”. 

Rearranging the formula to solve for D yields: 

D = Q/20. 

Sources that are farther from the PSD source than the calculated value for D are excluded from the 

modeling analysis, while those closer must be included. Table 4 shows the sources included in the 

AVAQMD inventory that have emissions greater than 20 tpy, the resulting value of D, and their distance

from PHPP. As seen in Table 4, only the USAF Plant 42 sources are closer than their respective values

of D and therefore are recommended for inclusion in the cumulative modeling analysis. Per AVAQMD, 

the Bolthouse Farms emission sources are mobile and widely distributed amongst several agricultural 

areas in the Antelope Valley, with the majority of the emissions occurring in the eastern part of the valley 

near Lake Los Angeles, a point over 20 km from PHPP. Because of the distributed nature of these 

sources, the distance from PHPP to most of the locations where the emissions occur, and the fact that 

these emissions all occur to the east, or downwind of the prevailing wind direction from PHPP, Bolthouse 

Farms was not included in the modeling. As a result, only the USAF Plant 42 sources (Lockheed and 

Northrop) were included in the cumulative modeling in addition to the PHPP sources. The email from 

AVAQMD regarding Bolthouse Farms is included in Attachment C. 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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D. USAF Plant 42 Sources and Boundary 

The USAF Plant 42 sources were included in the previous PHPP cumulative 1-hour NO2 modeling 

analysis submitted by AECOM to EPA on October 7, 2010. However, in December 2010, Chris Anderson 

of AVAQMD notified AECOM via email that the emissions provided for the USAF Plant 42 sources were 

mislabeled (emissions were labeled lb/hr but were actually in tons/hr), requiring new modeling with the 

revised emissions. Prior AECOM modeling analyses had conservatively combined the emissions into 

fewer sources to simplify and facilitate the model runs. However, due to the significantly higher emission 

rates with the corrected units, for this updated modeling it was decided to model each source in its correct 

location rather than use the condensed source methodology that had been previously applied. There are

a total of 53 permitted emission sources at USAF Plant 42, 36 at Lockheed-Martin and 17 at Northrop 

Grumman. The characteristics and emissions of each source are given in Table 5 (volume sources) and 

Table 6 (point sources). 

A further review of the USAF Plant 42 sources showed that of the 53 sources, 32 are emergency engines,

either providing power in the case of emergency or powering fire pumps in the case of a fire. The EPA

guidance memo goes into great detail (pages 8 and 9) discussing the problems associated with sources 

that operate only intermittently being modeled against a probabilistic (e.g., 98th percentile) standard such 

as the new 1-hour NO2 NAAQS, eventually concluding: 

“For the reasons discussed above, EPA believes the most appropriate data to use for compliance 

demonstrations for the 1-hour NO2 NAAQS are those based on emissions scenarios that are 

continuous enough or frequent enough to contribute significantly to the annual distribution of daily 

maximum 1-hour concentrations.” 

Despite the discussion above that would likely eliminate the need to model the emergency engines at 

USAF Plant 42 (along with other intermittent sources such as the test jet stand) completely, and despite 

the fact that no more than a handful of these sources would be tested at any given time, the PHPP 

cumulative modeling (that was completed prior to the release of the new EPA guidance) takes the 

extremely conservative step of not only including the PHPP emergency sources as well as all of the 

USAF Plant 42 sources, but also assumes that these engines are being tested simultaneously, and 

therefore all 32 of them are modeled as if a full hour of emissions occurred in the same hour. It was also 

assumed that testing would occur during the daytime anytime in a 12 hour window (6 am – 6 pm) on any 

single day. Given that the majority of these sources are limited by permit to 20 hours testing per year, and 

testing typically occurs only once every week for less than one hour, modeling a full hour of operations 

during any of 12 hours in the day remains a very conservative assumption. 

In addition to updated emissions from USAF Plant 42, AECOM also revisited the fence line receptors to 

be used for the USAF Plant 42. AECOM requested and received from AVAQMD in January 2011 a figure 

depicting the fence line of USAF Plant 42. Prior modeling had assumed receptor locations within the 

USAF Plant 42 property, but since USAF Plant 42 is a fenced, secure area without public access, the 

area within the fence line would not be considered to be ambient air with respect to USAF Plant 42 

sources (EPA memo from Joseph Tikvart, 1/21/86). The updated fence line used in this cumulative 

analysis is shown in Figure 2, and a copy of the email from AVAQMD is included in Attachment C. 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP Table 4: Sources Considered for Inclusion in PHPP 1-hour Cumulative NO2 Modeling 

Facility Name Street City NOx (tpy) Lat Long Distan

(miles

USAF Plant 421 Palmdale 22.5 34.638 -118.100 0.25 Calmat Co. DBA Vulcan Materials East Ave T Little Rock 43.3 34.543 -118.014 8.49 Vulcan Materials Co. 155th and Hwy 138 Pearblossom Llano 25.3 34.506 -117.853 17.07 Granite Construction Co. East Ave T Little Rock 21.7 34.543 -118.010 8.66 Holliday Rock Company East Ave T Palmdale 35.9 34.543 -117.993 9.29 Mtn. High Ski Area East Hwy 2 Wrightwood 21.3 34.377 -117.692 29.76 Mtn. High Ski Area West Big Pines Hwy Wrightwood 23.8 34.384 -117.706 28.83 Lancaster Landfill East Ave F Lancaster 43.5 34.748 -118.120 7.51 Antelope Valley Recycling West City Ranch Rd. Palmdale 56.1 34.570 -118.150 5.45 Bolthouse Farms2 District Wide Lancaster 136.1 varies Varies 2.8-11. Consists of both the Lockheed-Martin and Northrop-Grumman sources. 2. Bolthouse Farms emissions are from mobile sources widely distributed across Antelope Valley agricultural sites. Per Chris Anderson 

of these emissions occur in the eastern part of the valley near Lake Los Angeles, a distance of more than 20 km from PHPP. 

Table 5: USAF Plant 42 Volume Source Parameters 

Source ID Facility UTM Easting (NAD27) UTM Northing (NAD27) Base Elev. (m) Rel. Hgt. (m) Sigma-Y Sigma-Z 

S024 Lockheed 398081.6 3830683.0 746.8 3.05 222.49 1.86 S048 Lockheed 399992.6 3831386.0 746.8 5.80 1.21 6.98 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP Table 6: USAF Plant 42 Point Source Parameters 

Source ID Facility UTM Easting (NAD27) UTM Northing (NAD27) Base Elev. (m) Stack Hgt. (m) Temp (°K) Exit Vel. (m/s) Exit. Diam. (m) 

S066 Lockheed 400264.6 3833225.0 746.8 2.6 505.4 4.3 1.68 S067 Lockheed 400236.6 3833225.0 746.8 3.1 505.4 4.3 1.68 S068 Lockheed 400230.5 3833236.0 746.8 16.8 883.2 90.0 0.10 S070 Lockheed 400595.6 3833212.0 746.8 1.5 783.2 69.9 0.08 S071 Lockheed 400244.6 3833417.0 746.8 1.8 835.9 44.6 0.10 S072 Lockheed 397548.7 3830488.0 746.8 0.5 713.7 51.3 0.25 S073 Lockheed 397548.6 3830677.0 746.8 3.0 713.7 51.3 0.25 S074 Lockheed 397469.6 3831064.0 746.8 3.0 713.7 35.5 0.20 S075 Lockheed 398078.7 3830369.0 746.8 3.1 505.4 22.8 1.22 S076 Lockheed 398040.7 3830366.0 746.8 2.6 505.4 21.6 1.22 S077 Lockheed 398050.6 3830366.0 746.8 5.4 505.4 21.6 1.22 S078 Lockheed 398097.6 3830381.0 746.8 12.2 830.9 85.0 0.15 S081 Lockheed 397550.6 3830881.0 746.8 6.1 883.2 131.3 0.05 S085 Lockheed 397437.6 3830322.0 746.8 13.7 820.9 54.4 0.15 S087 Lockheed 397689.7 3830861.0 746.8 3.7 883.2 69.8 0.05 S088 Lockheed 397749.6 3830401.0 746.8 1.5 727.6 66.5 0.15 S089 Lockheed 397753.6 3830401.0 746.8 1.5 727.6 66.5 0.15 S090 Lockheed 397748.6 3830415.0 746.8 1.5 727.6 66.5 0.15 S091 Lockheed 397753.7 3830415.0 746.8 1.5 727.6 66.5 0.15 S092 Lockheed 397885.6 3830400.0 746.8 1.5 727.6 66.5 0.15 S093 Lockheed 397885.6 3830415.0 746.8 1.5 727.6 66.5 0.15 S094 Lockheed 397880.7 3830415.0 746.8 1.5 727.6 66.5 0.15 S095 Lockheed 397875.6 3830400.0 746.8 1.5 727.6 66.5 0.15 S097 Lockheed 398045.6 3830521.0 746.8 2.1 505.4 14.4 0.31 S098 Lockheed 398053.6 3830521.0 746.8 2.1 505.4 14.4 0.31 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP 

Source ID Facility UTM Easting (NAD27) UTM Northing (NAD27) Base Elev. (m) Stack Hgt. (m) Temp (°K) Exit Vel. (m/s) Exit. Diam. (m) 

S099 Lockheed 398083.6 3830535.0 746.8 3.1 477.6 20.0 1.22 S105 Lockheed 399337.7 3830928.0 746.8 16.8 802.6 40.5 0.08 S106 Lockheed 399511.6 3831148.0 746.8 2.0 505.4 8.5 0.92 S107 Lockheed 399504.6 3831154.0 746.8 7.6 505.4 9.5 0.92 S108 Lockheed 399502.6 3831136.0 746.8 12.2 816.5 47.6 0.08 S110 Lockheed 399563.6 3831102.0 746.8 18.3 802.6 40.5 0.08 S112 Lockheed 399652.6 3831240.0 746.8 21.3 802.6 40.5 0.08 S114 Lockheed 397299.6 3830864.0 746.8 6.1 780.4 54.3 0.08 S115 Lockheed 398550.6 3831532.0 746.8 12.2 862.0 26.6 0.08 S208 Northrop 401314.2 3833302.0 789.3 12.5 505.4 6.6 0.92 S209 Northrop 401325.6 3833300.0 789.3 12.5 505.4 8.8 0.92 S210 Northrop 401325.7 3833302.0 789.3 12.5 505.4 11.1 0.92 S211 Northrop 402121.3 3833533.0 789.3 10.7 505.4 0.0 0.61 S212 Northrop 402126.2 3833533.0 789.3 10.7 505.4 0.0 0.61 S215 Northrop 402103.5 3833516.0 789.3 10.7 466.5 18.3 0.31 S216 Northrop 402104.7 3833516.0 789.3 10.7 466.5 18.3 0.31 S217 Northrop 401067.7 3833333.0 789.3 2.3 797.0 12.1 0.13 S218 Northrop 400951.6 3833528.0 789.3 2.9 797.0 18.7 0.23 S219 Northrop 401083.8 3833145.0 789.3 2.3 797.0 12.1 0.13 S220 Northrop 401527.6 3833989.0 789.3 1.5 797.0 2.6 0.10 S221 Northrop 401330.7 3833302.0 789.3 2.5 797.0 12.2 0.10 S222 Northrop 402128.7 3833515.0 789.3 10.4 549.8 1.4 0.20 S223 Northrop 402130.7 3833516.0 789.3 3.0 752.6 16.3 0.17 S224 Northrop 402132.9 3833516.0 789.3 0.3 741.5 12.4 0.12 S225 Northrop 401989.3 3833728.0 789.3 3.0 797.0 12.2 0.17 S226 Northrop 401461.5 3833769.0 789.3 3.0 797.0 12.2 0.17 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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E. Updated 1-hour NO2 Cumulative NAAQS Modeling Results 

The updated PHPP cumulative NO2 modeling was performed using the same methodology as discussed 

in section 3.0 of the Palmdale Hybrid Power Project PSD Application, Supplemental Information (AECOM, 

July 20, 2010), except that the USAF Plant 42 sources were included in addition to ambient background. 

Because emission sources cannot contribute to an air quality standard violation on their own property, the 

cumulative model run included only those receptors not located within the USAF Plant 42 ambient air 

boundary. Compliance with the 1-hour NO2 NAAQS for PHPP-only sources was already demonstrated at 

all receptors within the boundary in the PHPP Supplemental Information submittal. 

The model was run for both the startup / shutdown and normal operations scenarios with the following 

assumptions regarding the PHPP ancillary equipment sources. Again, the new modeling guidance 

suggests that these intermittent sources do not need to be modeled at all, but since the modeling is 

conservative and in order to not redo it again, we continue to include these sources in the modeling:

a. The PHPP emergency generator and fire water pump will not be tested while the combustion 

turbines are in the startup or shutdown process. 

b. The PHPP emergency generator and fire water pump engine will not be tested simultaneously. 

The output from the AERMOD run was then processed using the “Post-1hr” post-processor created by 

AECOM and described in section 3.2 of the PHPP Supplemental Information submittal, and the worst 

case impact was compared to the standard. The results are presented below with the 3-year average 

98th percentile background added to all modeled impacts as described previously. The results, as shown 

in Table 7, demonstrate that the worst case impacts occur during startup / shutdown scenario, an 

intermittent case that the 3/1/11 EPA guidance memo suggests can be excluded in some cases, but was 

kept in the modeling to be conservative. When the 3-year average 98th percentile background from 2007 

– 2009 is added to the very conservative modeling, the maximum impact of 186.9 μg/m3

 is below the 

NAAQS of 188 μg/m3

. Therefore, compliance with the NAAQS is demonstrated for PHPP, and no further 

analysis is required. 

All modeling and calculation files associated with the cumulative 1-hour NO2 modeling analysis are 

included in Attachment A to this memo. 

Table 7: Revised Cumulative 1-hour NO2 NAAQS Modeling Results 

Modeled Concentrations (μg/m3) 

Modeling Scenario 

PHPP with updated

USAF Plant 42 

Sources and 

Receptors 

Backgrounda Sum % of 

Standard 

Normal Operations - No PHPP 

Emergency generator 88.2 77.1 165.3 87.9% 

Normal Operations - No PHPP Fire 

Water Pump 108.2 77.1 185.3 98.6% 

Startup/Shutdown - No PHPP 

Emergency generator 109.7 77.1 186.9 99.4% 

a. Background based on 3-year average 98th percentile background from 2007 – 2009 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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III. Updated 24-hour PM2.5 NAAQS Cumulative Modeling 

The PHPP PSD Application submitted on April 1, 2009 contained a cumulative PM2.5 NAAQS analysis 

which included other nearby (i.e., USAF Plant 42) sources of PM2.5 emissions. The USAF Plant 42 

sources were the only ones that the AVAQMD had recommended be included for the cumulative 

modeling analysis for PM10/PM2.5. However, in March 2010, EPA requested that this cumulative 

analysis be expanded to include additional sources up to 50 km from the PM10 Significant Impact Area 

(SIA) from the power plant site. Since modeling had determined that the PM10 24-hour impacts fell to 

less than the Significant Impact Level (SIL) within 400 meters of the PHPP, an area of 51 km was used to 

assess the cumulative PM2.5 impacts. Two other sources, Granite Rock Construction and Robertson’s 

Ready Mix, were identified for inclusion in the PM2.5 cumulative NAAQS analysis. An updated cumulative

PM2.5 NAAQS analysis was submitted to the EPA by AECOM in PHPP PSD Application, Supplemental 

Information, in July 2010. No comments have been received to date from EPA on the PM2.5 analyses 

submitted in July 2010. 

A. Updated USAF Plant 42 Sources 

Similar to the NOx emissions provided by the AVAQMD for the USAF Plant 42 sources, the AVAQMD 

notified AECOM in December 2010 that the short-term PM2.5 emissions for these sources were 

mislabeled as lb/hr, when they were actually in tons/hour. Therefore, updating of the cumulative 24-hour 

PM2.5 NAAQS analysis with the corrected emissions was necessary. Similar to the cumulative NO2

analysis discussed in this memo, AECOM implemented the same refinements to the sources and 

receptor grids to account for the higher emission levels. That is, the sources were now modeled as 

individual sources rather than being combined for simplification and the USAF Plant 42 fence line was 

used as the ambient air boundary for the cumulative modeling (see Figure 2). 

At Lockheed Martin, there are 88 sources included in the PM2.5 inventory, of which 55 are permitted and 

33 were unpermitted. At Northrop Grumman, there are 129 sources included in the inventory, of which 

only 23 are permitted, and the remaining 106 sources are unpermitted. At Lockheed Martin, 25 of the 

sources are emergency combustion engines, while at Northrop Grumman 7 of the sources are 

emergency combustion engines. These engines are only tested up to one hour per week and would 

rarely, if ever, be tested at the same time. The 3/1/11 EPA modeling guidance memo regarding 1-hour 

NO2 NAAQS discusses how the modeling of intermittent sources like emergency engines is likely overly 

conservative for standards with a probabilistic form (i.e., a 98th percentile value). As the 24-hour PM2.5 

NAAQS is a similar probabilistic form, it can be argued that the emergency engines should be excluded 

from the PM2.5 modeling as well. Nonetheless, they were conservatively included in the modeling as if

they were all being tested simultaneously. 

Because such a large number of sources at USAF Plant 42 operate only intermittently or are mobile 

sources that operate at different locations across the facility at irregular schedules, including them all in 

the modeling operating 24 hours a day is unrealistically conservative. In order to better characterize the 

sources to be modeled, copies of the operating permits for the two USAF Plant 42 facilities were obtained 

from AVAQMD, and several email requests were made to the contractors responsible for submitting 

emissions information for USAF Plant 42. As a result, a number of refinements were made. The PM2.5 

emissions for all USAF Plant 42 sources used in the updated modeling are provided in the spreadsheet 

USAF Plant 42 Source Characteristics.xlsx in Attachment A. Copies of all email correspondence 

regarding USAF Plant 42 sources are included in Attachment C. 

It should be noted that the HARP file presented the emissions as PM, not PM2.5. Most sources had an 

extremely conservative conversion rate from PM to PM2.5 associated with them in the HARP file. In 

order to expedite the completion of the modeling, refinement of PM emissions to PM2.5 was only 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

13

performed for those sources showing high modeled impacts. Additionally, the majority of the sources in 

the HARP files specified limits in the number of hours the source could run in a 24-hour period. For this 

analysis, only the emergency engines were restricted by their listed hours of operation. This is yet 

another factor in the conservatism of the modeling analysis: many sources’ emissions are total PM, not

PM2.5 emissions, and many sources are allowed to operate more hours in the modeling than they would 

in reality. The following is a summary of the refinements made to USAF Plant 42 sources: 

• Hours of operations restrictions: Similar to the NO2 modeling, it was assumed that testing of the 

37 sources representing emergency generator and fire water pump engines, along with jet test 

stands, would occur during the daytime, which was conservatively assumed to be up to 12 hours 

per day, from 6 am through 6 pm. 

• As a refinement to some of the sources showing the highest modeled impacts, the given HARP 

conversion rate from PM to PM2.5 for 4 of the sources was applied. 

• Source S055, the cooling tower at Lockheed, had incorrect emissions in the transaction file. 

Email correspondence with the consultant responsible for Lockheed emission reporting (included 

in Attachment C) confirmed the error and provided the correct emission rate of 0.225 lb/hr which 

was corrected in the modeling. 

• Source S046, various jet engine testing at Lockheed, was characterized in the HARP files with 

short-term emissions that would exceed the permitted annual emissions limit in less than one 

day. Email correspondence with Lockheed’s consultant indicated that these are mobile sources 

with a variable operating schedule and intermittent use. Because these sources are not 

permitted, are rarely used, and the emissions occur at different locations at various times, this 

source was omitted from the modeling. 

• Source S051 represents various small motors used in ground support tasks at Lockheed. Short 

term emissions for these sources were characterized in the HARP files at levels that would 

exceed the permitted annual emissions limit in less than one day. Again, email correspondence 

with the consultant indicated that these were mobile, non-permitted sources with no predictable 

schedule or location of use. Therefore, this source was excluded from the modeling. 

Figure 3 shows the locations of the PHPP and USAF Plant 42 facilities/sources that were included in the 

cumulative PM2.5 modeling. 

B. Updated Ambient Background Data 

Ambient background data for PM2.5 are available from the monitor located at 43301 Division St. in 

Lancaster, California, located approximately two miles from the PHPP site. Background data for 2005 –

2007 were used in the PSD Application, while data for 2006 – 2008 were used in the July 2010 submittal. 

For this updated analysis, data for 2007-2009 were used, since the data available on the AIRS database

website (http://www.epa.gov/ttn/airs/airsaqs/detaildata/downloadaqsdata.htm) are not yet complete for 

2010. For the 24-hour period, the 3-year average of the 98th percentile values was used. For the annual 

period, the 3-year average annual mean was used. The PM2.5 background values for 2007 – 2009 from 

the Division Street Monitor are shown in Table 8. 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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Table 8: Ambient PM2.5 Background Concentrations at Lancaster Monitoring Station 

Pollutant Period Measure 

PM2.5 Ambient Background (μg/m3) 

2007 2008 2009 Max. 3-Year 

Average 

PM2.5 

24-hour 

1

st-high 25 24 20 25 23 

2

nd-high 20 13 16 20 16.3 

98th % 20 13a 16 20 16.3 

Annual Mean 8.0 7.1 7.8 8.0 7.6 

a. The July 2010 submittal contained an error in the 98th percentile value for 2008. This PM2.5 value has 

been corrected in this updated analysis. 

C. Modeling Methodology 

Beside the changes discussed above, all other aspects of the PM2.5 cumulative NAAQS analysis remain 

unchanged from the analysis presented in July 2010. These aspects include the EPA modeling guidance 

followed (i.e., the March 23, 2010 EPA memo regarding the modeling of PM2.5 found at 

http://www.epa.gov/region07/air/nsr/nsrmemos/pm25memo.pdf), the PHPP sources/stack parameters 

and emission scenarios, the meteorological data, and the receptor grids (except as indicated above for

USAF Plant 42 fence line). 

In order to streamline this updated 24-hour PM2.5 analysis, the receptor grid was then reduced to include 

only those receptors at which PHPP sources had a significant impact and therefore could potentially 

contribute to an exceedence of the NAAQS/CAAQS. The refined receptor grid used in the 24-hour 

cumulative PM2.5 model runs is shown in Figure 4. 

D. PM2.5 Updated Modeling Results and Discussion 

The results of the cumulative PM2.5 modeling are shown in Table 9. In the table, the average of the 

maximum modeled high-1st-high over the three years by receptor is summed with the 3-year average of 

the 98th percentile ambient background values for the 24-hour period. Similarly, the maximum annual 

impact over the three years is added to the average annual mean ambient background averaged over 

three years. The results are then compared to the 24-hour NAAQS for PM2.5 (35 μg/m3) and annual 

NAAQS/CAAQS for PM2.5 (15/12 μg/m3

). As shown in the table, the cumulative impacts for both periods 

are below their respective standards and thus compliance is demonstrated. 

The maximum modeled impact from the PHPP sources (including the emergency generator and fire water 

pump engine) is 12.57 μg/m3

. The non-PHPP sources (including the other two more distant sources 

[Granite Rock Construction and Robertson’s Ready Mix], as well as the USAF Plant 42 sources), 

contribute only 0.01 μg/m3

 to the maximum total impact. This contribution is the same as the previous 

modeling, demonstrating that non-Project sources have little or no impact at locations where PHPP 

sources have the most impact, which are relatively close to the plant site (as shown in Figure 4). 

The modeling and supporting files used in this analysis are included in Attachment A. 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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Table 9: PHPP Cumulative PM2.5 Modeling Results 

Pollutant Averaging 

Period 

Maximum AERMOD 

Modeled Concentrations 

(μg/m3)

Background b 

(μg/m3) 

Maximum 

Cumulative 

Modeled 

Result Plus 

Background

(μg/m3) 

NAAQS

(μg/m3)

PHPP 

onlya 

PHPP with 

Cumulative 

Sources 

PM2.5 

24-hour 12.57 12.58 16.3 28.9 35 

Annual 1.2 1.3 7.6 8.9 15c

a. 3-year average of High-1st-high value by receptor; 

b. 3-year average 98th percentile value for 24-hour and 3 year annual average mean from Table 8 

c. The annual PM2.5 CAAQS is 12 μg/m3, there is no separate 24-hour PM2.5 CAAQS

Please feel free to contact Richard Hamel at 978-589-3275/richard.hamel@aecom.com or Sara Head at 

805-388-3775/sara.head@aecom.com if you have any questions or comments regarding this information. 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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Figure 1: Relative Location of the PHPP Site and Non-Project Sources of NOX. 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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Figure 2: Updated USAF Plant 42 Ambient Air Boundary 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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Figure 3: USAF Plant 42 Sources included in the PHPP Cumulative PM2.5 Modeling 

Analysis 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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Figure 4: Receptors Used in Refined PHPP Cumulative PM2.5 Modeling Analysis 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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Attachment A: 

Electronic Modeling and Calculation Files Archive 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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Attachment B: 

Q/D Analysis Methodology from the 

North Carolina Air Quality Section 

“Screening Method for PSD” 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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Attachment C: 

Correspondence with Antelope Valley AQMD 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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Emails between Chris Anderson of AVAQMD and Rich Hamel of AECOM Regarding Cumulative 

NOX Source Inventory for PHPP 12/20/10 – 1/4/11. 

From: Hamel, Richard [mailto:richard.hamel@aecom.com] 

Sent: Monday, December 20, 2010 10:04 AM 

To: Chris Anderson 

Subject: More Requests Regarding PHPP

Chris, 

2 requests 

1) Regarding Plant 42. Per my voicemail, the impacts weren’t as bad as I thought all things 

considered, and I think that with some reasonable assumptions regarding the operations of the 

many ICU’s at the two sites we should be able to show compliance. Could you send me the 

permits for both Lockheed and Northrop-Grumman to take a look at so that I can identify what 

these sources are and what limitations I might be able to use in the modeling? 

2) Cumulative Sources: EPA is still uneasy about the selection of sources for cumulative modeling. I 

think what they are mostly looking for is a list of sources with some explanation of the criteria 

we subsequently used to eliminate some. As a result, I’d like to request a list of all sources 

within 60 km of the PHPP site that have annual emissions of NO2 > 20 tpy. 

Please let me know if you need any other information or want to discuss. 

Rich 

From: Chris Anderson [mailto:canderson@mdaqmd.ca.gov] 

Sent: Monday, December 20, 2010 2:51 PM 

To: Hamel, Richard 

Cc: Alan De Salvio 

Subject: RE: More Requests Regarding PHPP 

RichAttached are all active permits for both Northrop Grumman and Lockheed Martin. This should satisfy 

request #1. 

All permitted sources within 60 km that have annual emissions NO2 >20 tpy: The two sources we have 

named from the start, Northrop and Lockheed, are the only two that we have judged and determined to 

satisfy your request. Both sources have PTE >20 tpy for NOx (assume NOx=NO2) but not actuals. 

Bolthouse Farms is an agricultural source which we have recently permitted and inventoried. Their 

operations mainly take place on the east side of the Antelope Valley. These operations include using 

diesel ICE for crop irrigation purposes. NOx emissions from Bolthouse Farms DICE operations exceeds 

20 tpy, however these emissions are from their entire operation of DICE throughout the AV. Bolthouse 

has been assigned one facility number within the District, however they do have multiple facilites. At this 

time the AVAQMD is working with Bolthouse Farms to determine the exact size and number of these 

facilities. 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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Please review the attached and let me know if you have any questions or comments. 

Regards 

Chris A. 

From: Hamel, Richard [mailto:richard.hamel@aecom.com] 

Sent: Tuesday, January 04, 2011 10:48 AM 

To: Chris Anderson 

Subject: RE: More Requests Regarding PHPP

Chris, 

We’re back to looking at this again. Question for you as I’m not that familiar with the boundaries of 

Antelope Valley: When you say that Bolthouse Farms operations are mainly on the east side of the 

valley, where exactly is the eastern side of the valley? Can you give me a particular town or landmark it is 

near? 

Thanks, 

Rich 

From: Chris Anderson [mailto:canderson@mdaqmd.ca.gov] 

Sent: Tuesday, January 04, 2011 2:14 PM 

To: Hamel, Richard 

Cc: Alan De Salvio 

Subject: RE: More Requests Regarding PHPP 

RichWhen I say east side of the District I am referring to all areas east of Division St. Looking at an aerial 

photo from Google Earth you will notice that there are Agriculture Operations (AO) in City of Lancaster 

and Palmdale area due east of Plant 42 and then Northeast of Lancaster. Further east in the areas of 

Lake Los Angeles and further east near the county line there is also AO. Many of these sources are 

Bolthouse Farms, however there is a mix of smaller AO that can be seen that I chose not to include 

based on size of source. Again, with its emission across the District’s east side aggregated together, 

Bolthouse appears to be one large facility in HARP, however their emissions are spread out across the 

entire east side of the District. 

Let me know if these answers satisfy your requests completely and/or if you should have any other 

questions. 

Regards, 

Chris Anderson 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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Email from Chris Anderson of AVAQMD to Rich Hamel Regarding Plant 42 Ambient Air 

Boundary 1/5/11

From: Hamel, Richard [mailto:richard.hamel@aecom.com] 

Sent: Tuesday, January 04, 2011 1:48 PM 

To: Chris Anderson 

Cc: Alan De Salvio 

Subject: RE: More Requests Regarding PHPP

Chris, 

I do have one more follow up question: Do you have anything that would indicate the ambient air 

boundaries the two facilities (Lockheed and Northrop) use for their air modeling? With Plant 42 being 

restricted to the public there are a lot of fences around there, I’d like to see if I’ve got the fence lines for 

modeling set up correctly. I’ve taken a minimalistic approach in the previous modeling, but at this point I 

need to know what is considered within the ambient air boundary and to make sure I’m not considering 

some areas within the fence line of either facility as publicly accessible. 

Thanks, 

Rich 

From: Chris Anderson [mailto:canderson@mdaqmd.ca.gov] 

Sent: Wednesday, January 05, 2011 6:09 PM 

To: Hamel, Richard 

Cc: Alan De Salvio; Bret Banks 

Subject: RE: More Requests Regarding PHPP 

RichThe District has reviewed the boundaries of AF Plant 42 and its adjacent Aerospace Companies. As a 

result we have generated an aerial view outlining which areas are not available to the general public, i.e. 

location is fenced off, gated, guarded, and need to obtain permission prior to entering site. 

Please see the attached file. 

Should you have any questions please let me know. 

Chris 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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Emails between Chris Anderson of AVAQMD and Rich Hamel of AECOM Regarding Cumulative 

PM2.5 Source Inventory for PHPP 2/4/11 – 3/3/11. 

From: Hamel, Richard [mailto:richard.hamel@aecom.com] 

Sent: Friday, February 04, 2011 1:09 PM 

To: Chris Anderson 

Subject: RE: 2 Questions about emissions in HARP files 

Hi Chris, 

I was getting into taking a close look at this and it seems to me that the PM emissions (in the HARP file 

they are all listed as PM, no PM10 or PM2.5 breakdown) must be in lb/hr as opposed to tons/hour. 

Case in point: Lockheed device #90801, stack #50153 is their cooling tower, located (UTM NAD83 at 

397937.6 3830600.7). It’s a small 3-cell tower. It’s PM emissions are listed as 6.48. That can’t possibly be 

6.48 tons/hr out of a cooling tower, and the annual emissions for the same source are only 0.98 

tons/year. 

Frankly, even 6.48 lb/hr seems high, given that Palmdale’s 10 cell tower will only emit 1.63 lb/hr 

PM10/PM2.5, but again that 6.48 is in PM and not broken down by particle size. 

Thoughts? 

Rich 

From: John Pinsonnault [mailto:John.Pinsonnault@verdant-env.com] 

Sent: Tuesday, February 08, 2011 10:02 AM 

To: Chris Anderson; Been, Laura 

Subject: Re: FW: 2 Questions about emissions in HARP files 

Chris 

There does seem to be a problem with the hourly emission calculation from the cooling tower. The 

correct emission rate is 0.000113 tons per hour or 0.225 lb/hr. The calculations in our model appear to 

be correct so I am not sure where the problem occurred. I reviewed the other PM estimates and 

everything appears to be in line with our assumptions. 

As to whether these are actual emissions or PTE, that depends on the source and time period. Annual 

emissions are actual emissions. Hourly emissions from permitted combustion equipment are PTE since 

we are assuming heaters and permitted IC engines are operating at maximum rated capacity for the hour. 

Hourly emissions from AGE and Jet Engine Testing are not PTE. We make assumptions on typical 

operating profiles. For a spray booth, we have no idea what the max hourly coating rate is so we assume 

emissions are spread out over an eight shift. 

John 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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From: Hamel, Richard [mailto:richard.hamel@aecom.com] 

Sent: Friday, February 18, 2011 8:14 AM 

To: Chris Anderson 

Subject: RE: FW: 2 Questions about emissions in HARP files 

Hi Chris, 

I have a couple of additional questions related to the PM emissions included in the Plant 42 emissions

inventory. In doing the cumulative modeling, I've found 2 sources to be problematic, but I also think the 

reported emissions are likely very conservative. Both of the sources are non-permitted so I only have 

what information I can find in the HARP transaction files (these are both Lockheed Martin): 

Device: 90155, Stack 50141 (volume source): Listed as JP-TS Combustion, 

Jet Engine 

Operations: 16 hr/day 

Emissions: 

 Short term: 2.73E-3 tons/hr = 5.39 lb/hr 

 Annual: 2.7E-4 tons/yr = 53.93 lb/yr. 

Comments: Given the short term vs. annual emissions, the source obviously doesn't operate 16 hours / 

day since that would exceed the annual emissions in less than a day. Can you tell me anything else about 

how this source usually operates or what it is, or what the correct short term emissions should be? It's not 

a permitted source so there aren't any limitations per-se, but I can make operating assumptions in the

modeling based on reasonable normal use. 

The other is 3 devices combined into stack 50146 (volume source): 

90105: Distillate Combustion - Gas Turbine 

Operations: 16 hr/day 

Emissions: 

 Short term: 9.68E-4 tons/hr = 1.94 lb/hr 

 Annual: 27.1 lb/yr. 

 Conversion rate from PM -> PM2.5 = .967 

90116: Distillate Combustion - Gas Turbine 

Operations: 16 hr/day 

Emissions: 

 Short term: 8.47E-4 tons/hr = 1.69 lb/hr 

 Annual: 8.35 lb/yr. 

 Conversion rate from PM -> PM2.5 = .967 

90125: Distillate Combustion - Reciprocating Engine

Operations: 16 hr/day 

Emissions: 

 Short term: 8.44E-4 tons/hr = 1.69 lb/hr 

 Annual: 141.6 lb/yr. 

 Conversion rate from PM -> PM2.5 = .967 

Comments: Again, for the first 2, the annual emissions would be eaten up in less than one day at the 16 

hours / day rate, so either the short term emissions are incorrect or the sources don't in reality operate 

nearly that much. Also, the conversion rate listed in HARP is 96.7% of the PM is PM2.5. That seems high. 

Any idea where that reference comes from? Also, I wonder if these 3 sources are active at the same 

time? 

Thanks for any info. 

Rich 
AECOM 

Update to 1-hour NO2 and 24-hour PM2.5 NAAQS Analysis for PHPP March 2011

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From: John Pinsonnault [mailto:John.Pinsonnault@verdant-env.com] 

Sent: Thursday, March 03, 2011 12:33 PM 

To: Erkeneff, Kelly; Chris Anderson 

Subject: Re: FW: LM Inventory 

Chris 

None of these sources operate on a well defined schedule. 

Device: 90155, Stack 50141 (volume source): Listed as JP-TS Combustion, 

Jet Engine 

This describes jet engine testing out on the flightline. We typically track the amount of fuel used or

operating hours but do not know when testing takes place. In this case the schedule reflects an operation 

that could take place anytime during Lockheed's normal operating schedule. We have estimated hourly 

emissions assuming that an engine is tested for one full hour and based emissions on a typical load 

profile (ie some minutes at idle, the rest at military load). It is not unreasonable to assume that the test 

lasts a full hour. In some cases, Lockheed can test more than one engine during the year. In these 

circumstances, the hourly rates will reflect multiple engines operating at the same time which is not likely. 

Stack 50146 (volume source): 

90105: Distillate Combustion - Gas Turbine 

90116: Distillate Combustion - Gas Turbine 

90125: Distillate Combustion - Reciprocating Engine

These devices represent Ground support equipment. Again, this equipment can operate at any time 

during Lockheed's normal operation. We have no idea when this equipment operates or how many 

pieces of equipment operate simultaneously. The hourly emission rate assumes that all of the equipment 

is operating at 80% of load for one full hour (except for Start carts) which is very conservative. We

assume start carts operate for about 15 minutes during the hour. 

Estimating hourly emissions from this type of operation is very difficult. I was under the impression that 

these sources would be considered as mobile and excluded from the modeling. Has that changed? 

John