UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX

75 Hawthorne Street

San Francisco, CA 94105

November 1, 2010

Mr. Robert Kard, Air Pollution Control Officer

San Diego County Air Pollution Control District

10124 Old Grove Road

San Diego, CA 92131-1640

Dear Mr. Kard:

Thank you for your submission of San Diego County Air Pollution Control District’s 

(SDCAPCD) 2009 Ambient Air Monitoring Network Plan. We have reviewed the submitted 

document and have found that it meets the minimum requirements set forth under 40 CFR Part 

58.10. While this letter serves as official approval of the annual network plan, it does not 

constitute approval of the system modifications that are proposed in the plan for the future. We 

will continue to work with your district to review system changes as they proceed.

Enclosed, please find our comments on the plan. If you have any questions regarding 

this letter or the enclosed comments, please feel free to contact me at (415) 972-3851 or Kate 

Hoag at (415) 972-3970.

Sincerely,

/S/

Matthew Lakin, Manager

Air Quality Analysis Office

Air Division

Enclosure

cc: Mahmood Hossain, SDAPCD

David Shina, SDAPCD
Comments on 2009 Data Year Network Plan for San Diego County APCD 

Please update next year’s annual network plan to reflect the following comments:

1. The general process for soliciting public comments on the Annual Monitoring 

Network Plan is described on page 2. For future plans, please also submit the 

specific dates of the public comment period and specify whether or not any 

comments were received. 

2. Please include the design values used for determining minimum monitoring 

requirements. Also, the data used should include the most recent complete data 

year. For example, for your next Annual Monitoring Network Plan, the design 

values should be calculated using 2008-2010 data. 

3. Page 11 states that there are no required monitors for NO2, SO2 and Pb in 

California to comply with Appendix D. In future network plans, please revise 

this section to reflect changed requirements due to the recent NAAQS revisions.

4. Page 12 outlines the requirements for PM2.5 samplers. The table lists all the 

required monitors together. While most of the information needed is included in 

the footnotes, it might be more easily understood if the requirements and the 

monitors that satisfy them are listed separately. In addition, the footnote should 

list what monitor is fulfilling the collocation requirement for both the FRM and 

the continuous requirement.

5. Please specifically state which sites are meeting the collocation requirements for 

PM2.5 and PM10 and include proposed new collocation sites if a required site is 

moving or shutting down.

6. The discussion on page 12 of the suitability for comparison to the annual PM2.5

NAAQS discusses the appropriate scale, but not the FRM/FEM/non-FEM status 

of the monitors. Please include information about monitor type in this section 

and ensure that it is consistent with the information presented in the detailed site 

information.

7. Providing for Review of Changes to PM2.5 Network: 40 CFR 58.10(c) says:

(c) The annual monitoring network plan must document how States and 

local agencies provide for the review of changes to a PM2.5 monitoring 

network that impact the location of a violating PM2.5 monitor or the 

creation/change to a community monitoring zone, including a description 

of the proposed use of spatial averaging for purposes of making 

comparisons to the annual PM2.5 NAAQS as set forth in appendix N to 

part 50 of this chapter. The affected State or local agency must document 

the process for obtaining public comment and include any comments 

received through the public notification process within their submitted 

plan.

The discussion on page 12 of the network plan did not fully address this 

requirement. As an example of the type of language that would suffice, Santa 

Barbara’s network plan includes the following statement:

“The PM2.5 network of FRM monitors in California was largely established in 

1999 and completed in 2000. There are two monitors located in Santa Barbara and 
Santa Maria as part of this larger network in California. CARB located and 

operates these two monitors. SBCAPCD and CARB would discuss any proposed 

changes to the network of PM2.5 monitors in Santa Barbara County prior to any 

formal changes being made.”

8. Page 13 lists seven PM10 locations and page 16 states there are six PM10 sites

please make these references consistent. For future network plans, listing the site 

names in the requirements section may alleviate this confusion.

9. Page 15. The timeframe for EPA’s TSAs are every three years.

10. Please clarify which samplers in table 7 on page 18 are non-FEMs.

11. Proposed Changes

a. For all proposed changes, when the District has completed its evaluation, 

please submit any request with the appropriate documentation to EPA 

Region 9 for approval.

b. Is concurrent monitoring being performed for all pollutants at Kearney 

Mesa (Overland) before the move, or just ozone? (There is also NO2, 

PM2.5, PM10 and PAMS at this site.) Also, will the new site still be the 

collocated site for PM2.5 and PM10?

c. Will there be concurrent monitoring of gaseous pollutants at the new Otay 

Mesa-Donovan site before the old site closes?

d. Please submit the required information for moving the PAMS II site from 

KMA/MMR to Escondido to EPA Region 9.

e. The plan discusses shutting down the CO monitors at Chula Vista and 

Otay Mesa. Since EPA is currently reviewing the CO NAAQS, please 

consider as part of your evaluation that the CO monitoring requirements 

may change.

f. Please confirm whether the meteorology measurements at Mount Soledad 

were required by PAMS.

12. Detailed Site Information

a. The PM monitors at the Beardsley Street site are not listed in the detailed 

site information table.

b. Siting issues:

i. The distance to trees at the Del Mar monitoring site is listed as less 

than the recommended 10 meters. In such cases, it would be 

helpful to include a footnote that characterizes the trees (e.g., tree 

below height of probe, tree not in predominant wind direction, 

etc.). Refer to 40 CFR 58, Appendix E, Section 5.

ii. 40 CFR 58, App. E, 6.1 and Table E-1 describes the minimum 

separation distance between roadways and ozone monitor probes as 

10 meters for roadways with average traffic counts of less than 

1,000 vehicles per day. The detailed site information for the 

Beardsley Street and El Cajon sites lists the distance to the nearest 

streets as 7.6 and 7.5 meters, respectively. It is recommended that 

SDCAPCD ensure that this ozone monitor is meeting the siting 

criteria set forth by 40 CFR 58, App. E, 6.1. Because this ozone 

monitor is only violating the requirement by a minimal distance, it 
may be that taking a more precise measurement from the actual 

monitor rather than from the general site would resolve the issue. 

The network plan reports what seems to be a distance to the road 

applicable to the entire site in general, rather than the ozone 

monitor probe.

iii. Please list the traffic counts for the paved cross road at Donovan.

iv. When distances to more than one road are given for the 

requirement in 40 CFR 58, App. E, 6.1 and 6.2, specify which road 

corresponds to the vehicle counts provided.

v. Adjust the monitor objective and spatial scale for the monitors at 

Otay Mesa to reflect the current conditions at the site. 

vi. Please confirm whether the District will operate the same 

instrumentation at Donovan as at the original Otay Mesa site.

vii. Please confirm that the collocated monitors at Otay Mesa meet the 

requirements for distance from each other that is appropriate for 

their flow rate.

c. Please add the following information to the detailed site information table 

for each monitor (a template table is provided as an example on the 

following page):

i. Site type (SLAMS/SPM etc.)

ii. List FRM/FEM/non-FEM and method code for particulate 

monitors. 

iii. List POC for each monitor 

iv. Frequency of flow rate verification for manual PM samplers audit, 

App A, 3.3.2: e.g. weekly, bi-weekly, monthly? (can be quarterly 

for high volume samplers)

v. Frequency of flow rate verification for automated PM analyzers 

audit, App A, 3.2.3: e.g. weekly, bi-weekly, monthly?

vi. Frequency of one-point QC check, App. A, 3.2.1 (gaseous 

instruments): e.g. daily, weekly, bi-weekly?

vii. Date of the last Annual Performance Evaluation, App. A, 3.2.2 

(gaseous instruments)

viii. Dates of the last two semi-annual flow rate audits for PM monitors, 

App A 3.2.4 and 3.3.3 (automated and manual)

i. Date of the past year’s PM2.5-PEP and Pb-PEP audits, App A 3.2.7 

and 4.3.2.

ix. Will there by changes within the next 18 months? (Y/N)
Template for Detailed Site Information

Site Name

AQS ID

GIS coordinates

Location In shed, on school, etc.

Address

County

Dist. to road meters

Traffic count #

Groundcover Paved, vegetated, etc.

Representative Area List MSA or CSA (indicate which)

Pollutant O3 PM2.5

Monitor objective List objective List objective

Spatial scale List scale List scale

Site Type SLAMS/SPM etc SLAMS/SPM etc

Sampling method List instrument instrument / code

Analysis method N/A e.g., weighed by X 

lab

Start date Date when operation 

began

Date when operation 

began

Operation schedule e.g., 1:1 e.g., 1:3

Sampling season e.g., May-Nov. e.g., all year

Probe height meters meters

Distance from supporting 

structure

meters meters

Distance from 

obstructions on roof

meters meters

Distance from 

obstructions not on roof

meters meters

Distance from trees meters meters

Distance to furnace or 

incinerator flue

N/A meters

Distance between 

collocated monitors

N/A meters

Unrestricted airflow degrees degrees

Probe material e.g., Teflon N/A

Residence time X seconds N/A

Will there be changes 

within the next 18 

months?

Y/N Y/N

Is it suitable for 

comparison against the 

annual PM2.5?

N/A Y/N

Frequency of flow rate 

verification for manual 

PM samplers audit

N/A weekly, bi-weekly, 

monthly, quarterly 

(high vol)

Frequency of flow rate 

verification for automated 

PM analyzers audit

N/A weekly, bi-weekly, 

monthly, quarterly 

(high vol)?

Frequency of one-point 

QC check (gaseous)

daily, weekly, 

bi-weekly?

N/A

Last Annual Performance 

Evaluation (gaseous)

date N/A

Last two semi-annual flow 

rate audits for PM 

monitors

N/A dates