UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX 

75 Hawthorne Street 

San Francisco, CA 94105 

April 19, 2013

Ms. Karen Magliano, Manager 

Air Quality Data Branch

Planning and Technical Support Division

California Air Resources Board

P.O. Box 2815 

Sacramento, California 95812

Dear Ms. Magliano:

In the State of California twelve districts plus the California Air Resources Board (CARB) submit 

annual network plans in accordance with 40 CFR 58.10. The plans that were submitted by the following 

local agencies in California in 2012 have been approved: 

 Bay Area Air Quality Management District,

 Great Basin Unified Air Pollution Control District, 

 Imperial County Air Pollution Control District, 

 Monterey Bay Unified Air Pollution Control District, 

 North Coast Unified Air Pollution Control District, 

 Sacramento Metropolitan Air Quality Management District, 

 San Diego County Air Pollution Control District, 

 San Luis Obispo County Air Pollution Control District, 

 Santa Barbara County Air Pollution Control District, 

 South Coast Air Quality Management District, and 

 Ventura County Air Pollution Control District.

We have provided specific comments on the plans we received from local agencies through separate 

letters. We appreciate your efforts in preparing the “2012 Annual Monitoring Report for Small Districts 

in California,” submitted by CARB in June 2012. Based on the information provided in the plan, EPA 

approves all portions of the network plan except those specifically identified in Attachments A and B, 

for which no action is being taken at this time. San Joaquin Valley Unified Air Pollution Control District 

did not submit an annual network plan for 2012 and therefore we are not acting on the network plan for 

the San Joaquin Valley at this time.

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. Some annual network plans submitted by local agencies included CARB sites. 

Missing or deficient information for CARB sites in local agency plans was addressed in the approval 

letters for each local agency. For convenience, we are providing a synthesized list of these issues in 

Attachment C. In addition to the checklist (Attachment A) and list of specific plan elements where EPA

Region 9 is not taking action (Attachments B and C), enclosed are additional detailed comments on 

“2012 Annual Monitoring Report for Small Districts in California” (Attachment D). 

EPA Region 9 identified specific annual network plan requirements that were not addressed in any plan 

submitted in 2012. These include requirements that apply to the State or multiple jurisdictions, as well as 

for areas for which no plan was received (i.e., San Joaquin Valley). These issues are listed in 

Attachment E. Due to the closure and lack of approved replacement for the ozone monitor at Arvin Bear 

Mountain Road, the State of California does not currently meet the requirement for a maximum ozone 

concentration monitor in the Bakersfield Metropolitan Statistical Area (MSA). We therefore disapprove 

the 40 CFR 58 Appendix D 4.1(b) network requirement in that instance. 

EPA will continue to work with CARB and the San Joaquin Valley Air Pollution Control District 

(SJVAPCD) to resolve this issue prior to ozone data in the Bakersfield MSA being considered for a 

regulatory action. CARB and SJVAPCD are making efforts to find an adequate replacement for the 

previous Arvin Bear Mountain Road site. EPA appreciates CARB’s attempts to work with the ArvinEdison Water Storage District to return to the original site, and SJVAPCD’s recent Request for 

Proposals for an ozone saturation study to evaluate ozone gradients in the area. With respect to 

SJVAPCD’s study, EPA hopes to work closely with CARB and SJVAPCD in the study design and 

implementation, which could help inform the choice of an adequate replacement site for Arvin Bear 

Mountain Road. A replacement, once approved by EPA under 40 CFR 58.14, can be used as the basis 

for approval of the 40 CFR 58 Appendix D 4.1(b) requirement in future annual network plan actions.

All of the comments in Attachments A, B, C, D, and E should be addressed in next year’s network plans. 

If you have any questions regarding this letter or the enclosed comments, please feel free to contact me 

at (415) 972-3851 or Meredith Kurpius at (415) 947-4534.

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. Elements Related to CARB Sites in Local Agency Plans Where EPA is Not Taking Action

D. Additional Detailed Comments

E. Elements Not Represented in Any 2012 Annual Network Plans

cc: Ken Stroud, CARB

Mike Miguel, CARB
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.

 System modifications (e.g., site closures or moves) are subject to approval per 40 CFR 58.14(c). 

Information provided in the plan was insufficient for EPA to approve the system modifications 

listed in the plan per the applicable requirement. Therefore, we are not acting on the following 

items as part of this year’s annual network plan:

o Chico site relocation

o Placerville site relocation

o Fresno-1

st Street site relocation

o Discontinuation of PM10 at Mojave-Poole

o Discontinuation of PM10 at Canebrake

o Discontinuation of ozone at Truckee

o Discontinuation of NOx at Grass Valley

o Fort Bragg site relocation

 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 the 

following items:

Item Checklist Row 

(Attachment A) Issue

PM2.5 sampling schedule 45 Not meeting requirement

PM2.5 and PM10 co-location 32, 34 Not meeting requirement

Method code for each monitor 37 Not meeting requirement

Instrument parameter code 42 Not meeting requirement

Sampling season for ozone –

waivers not submitted

44 Not meeting requirement

Sampling schedule for PM10 46 Insufficient to judge

Instrument monitor type 39 Insufficient to judge

PM co-location distance 33 Insufficient to judge

Residence time 73 Not meeting requirement for 3 cases

Probe height 65 Not meeting requirement in 3 cases

Distance from trees 69 Not meeting requirement in 2 cases

Probe material 72 Insufficient to judge

Distance from supporting 

structures

66 Insufficient to judge

Distance from obstructions on 

roof

67 Insufficient to judge
Distance to furnace or 

incinerator flue

70 Insufficient to judge

Start date for each monitor 38 Not meeting requirement

Monitoring objective for each 

instrument

40 Not meeting requirement

Additional information for each of these items is in included in Attachment A.
Attachment C: Elements Related to CARB Sites in Local Agency Plans 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.

 System modifications (e.g., site closures or moves) are subject to approval per 40 CFR58.14(c). 

Information provided in the plan was insufficient for EPA to approve the following system 

modification listed in the plan per the applicable requirement: relocation of the Calexico Ethel 

SLAMS site. Therefore, we are not taking action on this item as part of this year’s annual 

network plan.

 EPA identified items related to CARB sites in annual network plan submitted by local agencies 

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 the following items:

Item Checklist Row 

(Attachment A) Issue

Distance from trees Imperial 69 Not meeting requirement in one instance

PM2.5 sampling frequency Imperial 45 Insufficient information to judge

PM10 sampling frequency Imperial 46 Insufficient information to judge

Scale of representation Imperial 16 Insufficient information to judge

PM2.5 collocation/Operating 

schedule

Imperial 32/14 Insufficient information to judge

Date of last two semi-annual 

PM flow audits

Imperial 30 Insufficient information to judge

Distance between collocated 

monitors

Imperial 33 Insufficient information to judge

Distance from obstructions not 

on roof

Imperial 68 Insufficient information to judge

Distance from furnace or 

incinerator flue

Imperial 70 Insufficient information to judge

Parameter code Imperial 42 Insufficient information to judge

Site type Imperial 41 Insufficient information to judge in some 

instances

Method code Imperial 37 Insufficient information to judge

Monitoring objective Imperial 40 Insufficient information to judge

Monitor type Imperial 39 Insufficient information to judge in some 

instances

Statement of purpose Imperial 2 Insufficient information to judge

Pb collocation Imperial 35 Insufficient information to judge

Designation of Pb monitors as Imperial 16 Insufficient information to judge
source-oriented 

Date of last two semi-annual 

Pb flow audits

Imperial 31 Insufficient information to judge

Sampling Schedule for PM2.5 Sacramento 45 Insufficient information to judge

Sampling Schedule for PM10 Sacramento 46 Insufficient information to judge

PM2.5 expected maximum 

concentration site identified as 

population exposure

Sacramento 55 Insufficient information to judge

Site type for each instrument Sacramento 41 Insufficient information to judge

Monitoring objective for each 

instrument

Sacramento 40 Insufficient information to judge

Date of last Annual 

Performance Evaluation 

(gaseous)

Sacramento 29 Insufficient information to judge in some 

instances

Dates of last two semi-annual 

flow rate audits for PM 

monitors

Sacramento 30 Insufficient information to judge in some 

instances

Scale of representativeness for 

each monitor

Sacramento 16 Insufficient information to judge in some 

instances

Frequency of flow rate 

verification for manual and 

automated PM samplers audit

Santa Barbara 

25-26

Insufficient information to judge for CARB 

sites within the Santa Barbara County 

APCD annual network plan

Frequency of one-point QC 

check (gaseous)

Santa Barbara 

28

Insufficient information to judge for CARB 

sites within the Santa Barbara County 

APCD annual network plan

Date of last Annual 

Performance Evaluation 

(gaseous)

Santa Barbara 

29

Insufficient information to judge for CARB 

sites within the Santa Barbara County 

APCD annual network plan

Dates of last two semi-annual 

flow rate audits for PM 

monitors

Santa Barbara 

30

Insufficient information to judge for CARB 

sites within the Santa Barbara County 

APCD annual network plan

Scale of representativeness San Luis Obispo 

62

Insufficient information to judge for Paso 

Robles site.

In addition, the following comments were made in EPA’s Sacramento Metro AQMD annual network 

plan approval letter:

 The site description on page 53 lists the Sacramento-T Street site as middle scale for all 

pollutants. Please clarify why this is the case, or change the site description and spatial scales as 

appropriate.

 The PM2.5 speciation monitor at the Sacramento-T Street site is listed as an SPM (Appendix B, 

page 55), but EPA’s website lists this as a CSN site. Please clarify this in your 2013 network 

plan.
Attachment D: 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.

 [Item 2] Statement of Purpose for Each Monitor: The purpose listed in Appendix D does not 

match Table 3. It appears that “purpose” in Appendix D is actually monitor type (see item 39).

 [Item 9] There are no requirements for NO2 area-wide or RA40 monitors in the areas 

represented in the plan for small districts. It would be useful to add a statement in the plan 

similar to that for NO2 near-road on p. 22 of plan that indicates that there are also no 

requirements for NO2 area-wide or RA40.

 [Item 16] Scale of representativeness for each monitor as defined in Appendix D: 

o Scale is provided in Section 4, Table 4 and also in Appendix D. The information in 

Appendix D is incomplete.

o Based on the road distance/count at both the Barstow and Roseville sites, neither can be 

considered a neighborhood scale site for ozone (see 40 CFR 58, Appendix E, Table E-1). 

Both should be changed to a middle scale sites and removed from the minimum 

monitoring requirements.

 [Item 18] MSA: Since this ANP covers much of the State, it would be helpful if the paragraph in 

Section 3 on MSAs listed all the MSAs in the State and then referenced which ones were 

addressed in this plan. It would also be very helpful to identify any areas in the plan that are not 

part of a Metropolitan Statistical Area – otherwise the minimum monitoring requirement tables 

create the perception that some areas covered in the plan were left off when in fact they are 

simply not in a Metropolitan Statistical Area. This can be figured out from Table 3, but a simple 

listing in the text in Section 3 would add a lot of clarity.

 [Items 25 and 25] Flow rate verification for PM samplers: Does CARB do the flow rate audits 

for all the local districts? If not, how is it verified that these are being done on the schedule listed 

in the plan? Please clarify how this information is verified if it is not directly obtained by CARB.

 [Item 28] Frequency of one-point QC check (gaseous): The plan indicates that all gaseous 

monitors have precision checks every two weeks. It would be surprising if this was universal 

among all sites in the plan since many agencies conduct automated nightly checks. Is it verified 

that these are done at this frequency?

 [Items 32 and 34] It would be helpful to list the PM2.5 and PM10 co-located sites.
 [Item 42] Site type:

o Something similar to site type is provided, although it is labeled as “Federal Monitoring 

Purpose.” While many of the Federal site types are provided, the list is not complete. 

Please either replace “Federal Monitoring Purpose” with “Site Type” (as defined in 40 

CFR 58, App. D 1.1.1) and add the additional categories (in particular, “population 

exposure” is an important site type that is not included) or add a note that “Federal 

Monitoring Purpose” is equivalent to “Site Type” and add the additional categories to the 

“Monitoring Purpose.”

o The relationship between Federal Monitoring Purposes for Tables 3 and 4 is unclear. The 

purposes listed do not match. In addition, the codes do not always match between the 

plans (e.g., Chico is not listed as “High Concentration” in both Tables).

 [Item 43] The following sites listed multiple instruments of the same parameter under the same 

POC:

o Lancaster PM10

o Trona PM10

o PM2.5 at Grass Valley (if the BAM is non-regulatory this is ok)

o PM2.5 at Truckee

o PM2.5 at Portola (if the BAM is non-regulatory this is ok)

 [Item 49] Minimum monitoring requirements for ozone should not include any ozone sites that 

do not meet traffic count/distance requirements to be considered neighborhood scale (see 40 

CFR 58, Appendix E, Table E-1) (i.e., Lancaster, Barstow, and Roseville – N. Sunrise).

 [Item 54] Required PM2.5 sites represent community-wide air quality: Numerous sites are listed 

as neighborhood scale (i.e., representing community-level air quality) and “Gnrl” which is 

population representation. Further, all areas in the plan have more than the required number of 

total PM2.5 instruments and so presumably this requirement is being met. However it cannot be 

determined which sites are considered required and it would be helpful for future plans to 

address this.

 [Item 55] For PM2.5, is at least one site in a population-oriented area of expected maximum 

concentration?: This requirement is per MSA and this plan does not include all information from 

each MSA, so this review is not comprehensive. Based on the review of the information in this 

plan, one site was identified that should be labeled as high (or max.) concentration: Chico 

(060070002). EPA’s review did not identify any additional issues.

 [Item 59] The areas represented in the plan do not include any STN sites. It would be helpful to 

state this.

 [Item 61] The areas represented in the plan do not include any PM10-2.5 sites. It would be 

helpful to state this.

 [Item 62] Distance of site from nearest road:

o Lancaster, Barstow, and Roseville – N. Sunrise are too close for the ozone monitors to be 
considered neighborhood scale. Lancaster is listed appropriately as middle scale but 

Barstow and Roseville – N. Sunrise need to be changed. All should be removed from the 

minimum monitoring counts.

o West Sacramento-15th St: distance to road listed as 3500m – please double-check this.

 [Item 64] Many of the detailed site reports list “roof” as the groundcover. A roof is not typically 

considered a groundcover. Please provide a description of the groundcover adjacent to the 

building on which the monitors are placed.
Attachment E. Elements Not Represented in Any 2012 California Annual Network Plans

[Items 49-50] Minimum ozone monitoring requirements for the Bakersfield MSA. The ozone 

monitoring site at Arvin-Bear Mountain Boulevard was forced to close in October 2010 due to 

the loss of the lease. Historically, that site measured the highest ozone concentrations in the San 

Joaquin Valley. Because ozone concentrations measured at CARB's new Arvin-DiGiorgio site 

are significantly lower than those measured at Arvin-Bear Mountain, this new site may not 

constitute an approvable, adequate replacement site under applicable Federal regulations (40 

CFR 58.14). The lack of a representative replacement design value ozone site in SJV could 

jeopardize our ability to make determinations of whether there were NAAQS violations (e.g. 

clean data findings or redesignations to attainment).

[Items 4-5] Modifications to SLAMS network: Network modifications are subject to the 

requirements of 40 CFR § 58.14 and require approval by EPA. EPA and CARB have established 

a process for proceeding with site closures and relocations in a way that avoids data 

completeness problems. Following this process is critical for all site changes, especially for 

closures of high concentration sites, crucial in determining compliance with the NAAQS. Also, 

the State of California’s Air Monitoring Technical Advisory Committee (AMTAC) document 

“Site Relocation and Parallel Monitoring Guidelines” (June 1997) may inform the process for 

these system modifications. Ongoing network modifications, including recent actions in the San 

Joaquin Valley, should follow the process established by EPA and CARB.

[Item 58] Background and transport PM2.5 sites: This requirement applies to the entire state. The 

universe of sites provided in this plan does not include PM2.5 background or transport sites but 

they likely exist elsewhere in the state. A state-level overview is necessary to address state-level 

requirements.

The following topics are addressed in most plans but would benefit from a state-level overview 

since the requirements either apply at the state level or involve multiple jurisdictions:

 Minimum monitoring requirements

 Co-location requirements

 NCore requirements

 STN requirements

 Transport and background sites