UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION IX 

75 Hawthorne Street 

San Francisco, CA 94105-3901 

ma1m9 

Ted Schade 

Air Pollution Control Officer 

Great Basin Unified Air Pollution Control District 

157 Short Street 

Bishop, California 935 14 

Dear Mr. Schade: 

Thank you for submitting the Great Basin Unified Air Pollution Control District's 

2009 Ambient Air Quality Monitoring Network Plan. We have reviewed the submitted 

document and have found that it meets the minimum requirements set forth under 40 

CFR Part 58.10. The comments enclosed with this letter identify several areas in the Plan 

where additional information is requested in order to complete the document and fully 

satisfy the requirements of 40 CFR Part 58.10. Rather than attempt to resolve these data 

gaps in this document, we request that GBUAPCD address the enclosed comments in 

next year's annual network plan which is due on July 1,201 0. 

If you have any questions regarding this letter or the enclosed comments, please 

feel free to c,ontact me at (4 15) 947-4226 or Michael Flagg at (41 5) 972-3372. 

-, ~iic"eG~~, 

a / 

/ 

__- --- 

, ' - Actingpanager 

Air Quality Analysis Office 

cc: Christopher Lanane 

Michael Flagg 

Pn'nred on Recycled Paper 
EPA Comments on the 2009 Ambient Air Quality Monitoring Network Plan 

40 CFR 58.10(a)(l) states that monitors must meet Appendix A, C, D, and E. The 

following information from these appendices should be included in the plan. 

Appendix A: 

Frequency of flow rate verification for manual PM samplers audit (App A, 3.3.2) 

Frequency of flow rate verification for automated PM analyzers audit (App A, 

3.2.3) 

Last two semi-annual flow rate audits for PM monitors (App A, 3.2.4 and 3.3.3) 

PEP audit dates 

Appendix D: 

To ensure network meets minimum monitoring requirements, the MSA 

population, and design value should be included for each pollutant. 

Appendix E: 

For each site: 

o Distance from nearest road 

o Traffic count of nearest road 

o Surrounding groundcover (e.g. paved, vegetated, etc.) 

For each rnonitor: 

o Probe height 

o Distance from structure 

o Distance from obstructions on roof 

o Distance from obstruction not on roof 

o Distance from trees 

o Distance to furnace or flue 

o Distance between collocated monitors 

o Unrestricted airflow in degrees 

40 CFR 58.10 (b) 

Location of each site: street address and geographic coordinates 

Identification of sites suitable and sites not suitable for comparison to the annual 

PM2.5 NAAQS as described in 40 CFR 58.30 

The "Detailed Site Information" table shown below is an example of how site 

information can be organized to ensure that each site and monitor meet the necessary 

regulatory requirements. 
Detailed Site Information 

Address 

Location 

County 

Dist. to road 

Traffic count 

I Area 

meters 

# 

Groundcover 

Representative 

supporting 

structure 

Distance from meters meters 

obstructions on ~ 

Paved, vegetated, etc. 

List MSA or CSA (indicate which) 

roof 

Distance from 

obstructions not on 

roof 

Distance from meters 

meters 

meters 

trees 

Distance to furnace 

or incinerator flue 

Distance between 

collocated 

monitors 

Unrestricted 

meters 

airflow 

Probe material 

Residence time 

Will there be 

changes within the 

next 18 months? 

Is it suitable for 

comparison against 

the annual PM2.5? 

Frequency of flow 

NIA 

NIA 

degrees 

meters 

meters 

degrees 

~g., Teflon 

X seconds 

YM 

N/A 

NIA 

NI A 

Nl A 

YM 

Yes for all current 

sites in Region 9. 

weekly, bi-weekly, 
monthly, quarterly 

(high vol) 

weekly, bi-weekly, 

monthly, quarterly 

(high vol)? 

NIA 

NIA 

dates 

rate verification for 

manual PM 

samplers audit 

Frequency of flow 

rate verification for 

automated PM 

analyzers audit 

Frequency of onepoint QC check 

(gaseous) 

Last Annual 

Performance 

Evaluation 

(gaseous) 

Last two semiannual flow rate 

audits for PM 

monitors 

NIA 

daily, weekly, biweekly? 

date 

NIA