UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX
75 Hawthorne Street San Francisco, CA 94105

March 27, 2013

Donald Gabrielson, Director Pinal County Air Quality Control District Air Quality Control District

P.O. Box 987 Florence, Arizona 85232

Dear Mr. Gabrielson:

Thank you for your submission of Pinal County Air Quality Control District’s (PCAQCD’s)

“ 2012 Ambient Monitoring Network Plan and 2011 Data Summary ” in July 2012 . Based on the information provided in the plan, EPA approves all portions of the network plan except those specifically identified below. With this plan approval, we also formally approve the following system modification: the conversion of the Cowtown (AQS ID: 04

- 021

- 3013) PM 2.5 monitors from Special Purpose Monitors (SPMs) to State and Local Air Monitoring Station (SLAMS).

Annual network plans are important documents for regulatory purposes (e.g., State Implementation Plans, designations and redesignations ) and public information, in addition 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. W hile the items in the checklist are required by EPA regulations , we acknowledge that we have not specifically requested some of this information in previous annual network plan reviews . We r ecognize 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

detailed feedback in the checklist where informati on should be included or revised in next year’s plan.

Please note that we cannot approve portions of the annual network plan for which the information in the plan is insufficient to judge whether the requirement 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

s pecific portions of your agency’s annual netw ork 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 commen ts on the plan (Attachment C). All of the

comments in Attachments A , B, and C should be addressed in next year’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 Mic hael Flagg at (415) 972

- 3372

.

Sincerely,

/s/

Matthew Lakin, Manager Air Quality Analysis Office

Enclosures:

A. Annual Air Monitoring Network Plan Checklist

B. Elements where EPA is Not Taking Action

C. Additional Detailed Comments

cc: Kale Walch, PCAQCDAttachment 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 plan s 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.

 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 associated appendices. Therefore, we are not acting on of the following items:

Item Checklist Row

(Attachment A) Iss ue

PM 2.5 co

- location 34 Not meeting requirement

PM 10 co

- location 32 Not meeting requirement

Continuous PM 2.5 57 Not meeting requirement

PM 2.5 sampling schedule

waiver 45 Insufficient information to judge

Ozone sampling season

waiver 44 Insufficient information to judge

Distance from supporting

structure 66 Insufficient information to judge

Distance from obstructions

on roof 67 Insufficient information to judge

Monitor type 39 Incorrect information in some instances

Monitor start date 38 Insufficient information

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

.Attachment C : Additional Detailed Comments

 Per 40 CFR 58 Appendix D, section (2)(e), the EPA Regional Administrator and state or local agencies ... “may divide the overall MSA/CSA monitoring responsibilities and requirements among the various agencies to achieve an effective network design. Full monitoring requirements apply separately to each affected State or local agency in the absence of an agreem ent between the affected agencies and the EPA Regional

Administr ator.” For future plans, please state if an agreement has been made to share network design responsibilities for any MSAs in your jurisdiction and attach

documentation.