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) PM2.5 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. While 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 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 

detailed feedback in the checklist where information 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 

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). 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 Michael 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, PCAQCD
Attachment B: Annual Air Monitoring Network Plan Items where EPA is Not 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.

 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)

Issue

PM2.5 co-location 34 Not meeting requirement

PM10 co-location 32 Not meeting requirement

Continuous PM2.5 57 Not meeting requirement

PM2.5 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 agreement between the affected agencies and the EPA Regional 

Administrator.” 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.