UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX
75 Hawthorne Street San Francisco, CA 94105

March 1, 2013

Mr . Mahmood Hossain

, Chief, Monitoring and Technical Services San Diego County Air Pollution Control District

10124 Old Grove Road San Diego, CA 92131

- 1640

Dear Mr. Hossain :

Thank you for your submission of the San Diego Air Pollution Control District’s “2011 Ambient

Air Quality Network Plan ” in June 2012

. Based on the information provided in the plan, EPA approves all portions of the network plan except those specifically identified below.

Annual network plans are important documents for regulatory purposes (e.g., State Implementation Plans, designations and redesignations) and public information, in add ition to the myriad uses by the air districts. EPA is revising the review process for annual network plans to specifically check and document the comprehensive set of items that are required to be included in the annual network plans per 40 CFR 58.10 in a consistent manner. We have created

a checklist that lists all these items and have included it as Attachment A. While the items in the checklist are required by EPA regulations, we acknowledge that we have not specifically requested some of this informatio n in previous annual network plan reviews. We recognize that your plan may not have all the items that we have currently identified and hope to work with you on the inclusion of these items in future plans. To facilitate these changes, EPA has provided

det ailed feedback in the checklist where information should be included or revised in next year’s plan.

Please note that we cannot approve portions of th e annual network plan for which the information in the plan is insufficient to judge whether the requirem ent has been met, or for

which the information , as described, does not meet the requirements as specified in 40 CFR 58.10 and the associated appendices. EPA Region 9 also cannot approve portions of the plan for which the EPA Administrator has approval authority. Accordingly, we are not acting on the specific portions of your agency ’s annual network plan listed in Attachment B.

In addition to the checklist and list of specific plan elements where EPA Region 9 is not taking

action , enclosed are additional detailed comments on the plan (Attachment C ). Since t he plan’s public comment period occurred after submission to EPA (July 1

– 31 st , 2012), also enclosed isconfirmation that the San Diego Air Pollution Control District did not receive public comments

as of November 14 th , 2012 (Attachment D). All of the comments in Attachments A , B, and C should be addressed in next yea r’s network plan. If you have any questions regarding this letter or the enclosed comments, please feel free to contact me at (415) 972

- 3851 or Dena Vallano at (415) 972

- 3134

.

Sincerely,

/s/

Matthew Lakin, Manager Air Quality An alysis Office

Enclosure s : A. Annual Air Monitoring Network Plan Checklist

B. Elements where EPA is Not Taking Action

C. Additional Detailed Comments

D. Public Comments Confirmation E

- mail

cc: Robert Kard , San Diego County APCD David Shina, San Diego County APCD Karen Magliano, CARBAttachment B : Annual Air Monitoring Network P lan I tems where EPA is N ot Taking

Action

We are not acting on the portions of annual network plans where either EPA Region 9 lacks the authority to approve specific items of the plan, or EPA has determined that a requirement is either not met or information in the plan is insufficient to judge whether the requirement has

been met.

 NCore, PAMS, STN, and the plan for NO 2 monitoring require EPA Administrator

ap proval. Per 40 CFR 58.11(c), NCore, PAMS, and STN network design and changes are subject to approval of the EPA Administrator and per 40 CFR 58.10(a)(5) plans for establishing NO 2 monitoring sites are submitted to the EPA Administrator for action.

Therefor e, we are not acting on these items.

 EPA identified items in you agency’s annual network plan where a requirement was not being met or information in the plan was insufficient to judge whether the requirement was being met based on 40 CFR 58.10 and the as sociated appendices. Therefore, we are not acting on of the following items:

Item Checklist Row

(Attachment A) Issue

Dates of last two semi

- annual

flow rate audits for Pb

monitors 31 Insufficient information to judge

Probe height 65 Not meeting requirement

Distance between co

- located

PM 2.5 and PM 10 monitors 33 Insufficient information to judge

Designation of any Pb

monitors 19 Not meeting requirement

Distance from obstructions not

on roof 68 Insufficient information to judge

Additional information for each of these items is in included in Attachment A

.Attachment C : Additional Detailed Comments

 [Item 6] No documentation or approval letter was included in the Plan related to previous system modifications. When providing fut ure plans for public comment, please include information (your agency’s submittal and EPA’s approval) pertaining to any modifications that were approved in the data year covered by the plan (e.g. 2012 changes for the plan submitted in 2012 )

.

 [Items 9

- 10] Although EPA Region 9 is not taking action on the NO 2 portions of the plans this year, for next year, please identify sites fulfilling the NO 2 area

- wide and RA40 requirements.

 [Item 16] According to Appendix E, section 6.3 (b), Camp Pendleton may need to be changed to urban/regional scale site for PM 2.5 based on site type (general/background),

distance to nearest traffic lane (15m) , traffic count for “B” St. E (n/a)

, and proximity to I

5 A ADT (100K).

 [Item 19] The El Cajon Pb monitor station is listed as “Population Exposure” (for NCore) in the detailed site descriptions, however, it is described as “population oriented; neighborhood” (App 7, p. 5), and not as either source

- oriented or non

- source

- oriented.

Please include t he source

- oriented or non

- source

- oriented designation for all Pb sites in next year’s plan.

 [Item 52] The minimum monitoring requirements are met for Pb, but the plan notes that official Pb sampling at airports started late ( 2012 )

.

 [Item 62] The El Cajon monitor station is listed as <10m ( 7.8 m ) from Redwood Ave.

 [Item 68] For future plans, as necessary, report any obstructions (on and off the roof) by providing a distance from the probe/inlet, as well as height of the obstruction.

 [Item 69] Chula Vista (9.35 m for O 3 ), Del Mar (7.6m for O 3 ), and Otay Mesa (5.2m for

PM 10 ) monitors are listed as <10m from trees. The plan notes that t he vegetation at Del

Mar is trimmed regularly to maintain a height 2m below the inlet. Please note in future plans whether t he trees at these sites may be impacting data quality.