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`1~' ; UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

Z~F ,o= REGION IX 

~rq< PROTEG~ 75 Hawthorne Street 

San Francisco, CA 94105-3901 

OE'C Q 1 2009 

Ted Schade 

Air Pollution Control Officer 

Great Basin Unified Air Pollution Control District 

157 Short Street 

Bishop, California 93514 

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, 2010. 

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

feel free to contact me at (415) 947-4226 or Michael Flagg at (415) 972-3372. 

Office 

cc: Christopher Lanane 

Michael Flagg 

Printed on Recycled Paper 

EPA Comments on the 2009 Ambient Air Quality Monitoring Network Plan 

40 CFR 58.10(a)(1) 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 minimurn monitoring requirements, the MSA 

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

Appendix E: 

® For each site: 

• Distance from nearest road 

• Traffic count of nearest road 

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

® For each monitor: 

o Probe height 

o Distance from structure 

• Distance from obstructions on roof 

• Distance from obstruction not on roof 

• Distance from trees 

o D.istance to furnace or flue 

• Distance between collocated monitors 

• 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 

Site Name 

AQS ID 

GIS coordinates 

Location In shed, on school, etc. 

Address 

County 

Dist. to road meters 

Traffic count # 

Groundcover Paved, ve etated, etc. 

Representative 

Area 

List MSA or CSA (indicate which) 

Pollutant 03 PM2.5 

Monitor ob' List ob'ective List ob'ective 

S atial scale List scale List scale 

Sampling method List instrument Sampling 

instrument 

Analysis method N/A e.g., weighed by X 

lab 

Start date Date when 

o eration be an 

Date when 

o eration began 

O eration schedule e.g., 1:1 e. ., 1:3, 

Sam ling season e. ., May-Nov. e.g., all year 

Probe hei ht meters meters 

Distance from 

supporting 

structure 

meters meters 

Distance from 

obstructions on 

roof 

meters meters 

Distance from 

obstructions not on 

roof ' 

meters meters 

Distance from 

trees 

meters meters 

Distance to furnace 

or incinerator flue 

N/A meters 

Distance between 

collocated 

monitors 

N/A meters 

Unrestricted 

airflow 

degrees degrees 

Probe material e.g., Teflon N/A 

Residence time X seconds N/A 

Will there be 

changes within the 

next 18 months? 

Y/N Y/N 

Is it suitable for 

comparison against 

the annual PM2.5? 

N/A Yes for all current 

sites in Region 9. 

Fre uency of flow N/A weekly, bi-weekly, 
rate verification for monthly, quarterly 

manual PM (high vol) 

sam lers audit 

Frequency of flow N/A weekly, bi-weekly, 

rate verification for monthly, quarterly 

automated PM (high vol)? 

analyzers audit 

Frequency of one- daily, weekly, bi- N/A 

point QC check weekly? 

(gaseous) 

Last Annual date N/A 

Performance 

Evaluation 

( aseous) 

Last two semi- N/A dates 

annual flow rate 

audits for PM 

monitors