Chief, Monitoring and Technical Services

San Diego County Air Pollution Control District

10124 Old Grove Road

San Diego, California 92131-1640

Dear Mr. Hossain:

In your previous monitoring annual network plan, San Diego County Air Pollution Control

District (SDCAPCD) requested EPA’s approval to consider the 20 10-2012 PM2.5data from your

continuous FEM monitors at the following sites as not eligible for comparison to the NAAQS: ElCajon (AQS II) 06-073-0003), San Diego-Downtown (AQS ID 06-073-1010), Escondido (AQS

ID 06-073-1002), Alpine (AQS ID 06-073-0006) and Camp Pendleton (AQS ID 06-073-1008).Your most recent monitoring annual network plan updates this request to include 2013 data from

the same monitors. This letter is in response to your requests and approves the monitors listedbelow for the specified dates as not eligible for comparison to the NAAQS (i.e., provides awaiver for NAAQS comparability).

According to 40 CFR 58.11(e), in order to be considered not eligible for comparison to the

NAAQS, continuous FEM PM25 data must be shown to not meet the criteria in 40 CFR 53 Table

C-4. These criteria describe the maximum allowable multiplicative and additive bias between afilter-based FRM PM2.5monitor and a Class ifi continuous FEM PM2.5monitor operating at the

same site. EPA based its evaluation on the criteria in 40 CFR 53 as described by our memo dated

April 20, 2013 and its attached document titled “Instructions and Tem?late for Requesting that

data from PM2.5Continuous FEMs are not compared to the NAAQS.”

We reviewed your request for 2010-20 12 data, and well as your updated request for 2011-2013data. After reviewing the information in your requests, we have determined that the following

monitors do not meet the bias criteria in 53 and are approved as not eligible for comparison to

the NAAQS for the noted time periods:

‘This memo and tools used for comparing FRM and continuous FEM data are found at EPA’s website:

htt:j/www.epa.gov/ttnamtii/contront.htm.

Printed on Recycled Paper
for the data in 2011-2013, and therefore the 2013 data are considered comparable to the

NAAQS. Likewise, since there is variability in the comparability between the filter-based and

continuous monitors throughout your network, we cannot approve a waiver from NAAQScomparability for the monitors at Alpine and Camp Pendleton without collocated filter-based

FRM data as the basis for such a request. However, since Alpine and Camp Pendleton started

operating in July 2012 and November 2011, respectively, they have not collected enough data to

calculate a design value that is valid for comparison to the NAAQS at this time.

Your request stated that you consider the continuous PM2.5data ofsufficient quality to report to

the AQI, and will be submitting the data to AIRN0w, so you may now re-load the data from themonitors and dates in the table above to AQS under the parameter code 88502.

If you have any questions regarding this letter or the enclosure, please feel free to contact me at(415) 947-4534, or Kate Hoag ofmy staff at (415) 972-3970.

Sincerely,

Meredith Kurpius, ManagerAir Quality Analysis Office

Enclosure:

A. EPA Evaluation ofthe Request for Exclusion ofPM2.5Continuous FEM Data

cc: David Shina, SDCAPCD

Sylvia Vanderspek, CARB
A. EPA Evaluation of the Request for Exclusion of PM2.5Continuous FEM Data 1

1 Data from 2010-2013 evaluated here was generated on May 12, 2014 using the EPA PM2.5continuous monito

assessment tool found at the website: http://www.epa.gov/airguality/airdata/ad rep frmvfem.html. A techni

tool is located at http://www.epa.gov/ttnamtjl/fjles/arnbjent/pm2S/comparabjljtyassessmenttool.pdf.
2011-2013

Continuous! PM. 5 PM5 Site Name Cont Method FRM Slope Intercept M

Site ID Cont. Cont End / City POC Description Sampler pairs (m) (y) req

Begin Date Date

per season

Sites with PM25continuous FEMs that are collocated with FRM5:

Winter = 63

MetOne BAM Spring = 86

El Cajon 06-073-0003 2 3/1/2011 12/31/2013 Summer = 93 1.13 1.98 

1020 (170) Fall =88

-

Total=330

Winter = 122

San Diego- MetOne BAM Spring = 146

06-073-1010 2 11/1/2011 12/31/2013 Summer = 155 1.08 1.16 

Beardsley 1020 (170) FaIl = 199

Total = 622

Winter = 84

MetOne BAM Spring = 89

Escondido 06-073-1002 3 1/1/2011 12/31/2013 Summer = 80 1.10 0.35 

1020 (170) FaIl = 87

Total = 340

Winter = 84

Escondido 06-073-1002 MetOne BAM Spring =92

4 1/1/2011 12/31/2013 Summer = 81 1.14 1.91 

1020 (170) FaIl = 84

Total= 341

Sites with PM2.5continuous FEMs that are not collocated with FRMs:

MetOne BAM Alpine 06-073-0006 1 7/1/2012 12/31/2013 1020 (170)

Camp MetOne BAM 06-073-1008 3 11/9/11 12/31/2013 Pendleton 1020 (170)