çSOS14 ,. UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION
IX 0 PRO

75 Hawthorne Street San Francisco, CA 941O539O1 JUN
3 0 2008 Mr. John Ching Program Coordinator Sacramento Metropolitan Air Quality Management District 12 Street,3 rd Floor Sacramento, CA 958 14-1908 Dear Mr. Ching: Thank youfor yoursubmission of the Annual Monitoring Network Plan for the Sacramento Metropolitan Air Quality Management District. We recognize that producing this document and the associated public inspection process represented new requirements and we appreciate youreffort tomeetthem. We have reviewed the submitted document and have found that it meetsthe minimum requirements
setforth under 40 CFR Part 58.10. The comments enclosed with this letter identify several areasin the Plan where additional information

is requested
in order to complete the Odocument and fully satisfy the requirements
of 40 CFR Part 58.10. Rather than attemptto resolve these data gapsin this document, we requestthat Sacramento Metro AQMD address the enclosed comments
in next year’s annual network plan which is due on July 1, 2008. If youhave any questions regarding this letter orthe enclosed comments, please feel free tocontactmeat (415) 972-3261
orMeredith Kurpius
at (415) 947-4534. Sincerely, Sean P. Hogan, Manager Air Division Technical Support Office 0

Printed on Reycted PaperComments Public Process: Please attach the notice or web screen shot of the announcement
for public comment. Monitoring Objective vs. Site Type (section 2.1): In the first paragraph of section 2.1 monitoring objectives are defined as: 1) provide air pollution data to the general public in a timely manner;
2) support compliance with ambient air quality standards and emission strategy development; and 3) support air pollution research studies. This is consistent with the definition for monitoring objectives
in 40 CFR 58 Appendix

D section

1. Tables

2 and
3 on page
6 then list the six site types (also defined in 40 CFR 58 Appendix

D section
1) but uses the heading of “Monitoring Objective” Likely, the confusion arose because EPA requested monitoring objective information

as part of the network plan in 40 CFR 58.10 when it is really site type that is desired. One solution to clarify this point in the network plan is to add a sentence defining “site type” at the end of the first paragraph
in section 2.1 and then change the headings
in Tables

2 and 3. Minimum monitoring requirements (section 3.0). It would be helpful to restate the population of the Sacramento-Arden Arcade-Roseville MSA in the first paragraph of section 3.0 since it is relevant for determining minimum monitoring requirements. Dates (throughout document, but see annual data certification and some audit dates): Due to the timing of the submittal of this plan, it is difficult
to determine
if some of the dates are meant to reflect

a plan for the 2006 time period or 2007 time period. For example,
in Section 6.0 the date for annual data certification

is June 2006. For a plan submitted on July 1, 2007 to cover the period of January-December, 2006 this would be acceptable. However, since the plan was submitted almost

a full year late it is difficult
to interpret this and other dates.
It is recommended that future plans specify the time period that the report is intended
to cover.