UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 


REGION 10 


1200 Sixth Avenue, Suite 900 

Seattle, WA 98101·3140 

In. OF 

AIR WASTE. AND TOXICS 

OCT 052011 

Ms. Barbara Trost 

Air and Water Quality Division 

Alaska Department of Environmenlal Conservation 

555 Cordova Street 

Anchorage, Alaska 99501-2617 

Dear Ms. Trost: 

We have evaluated the 2011 Alaska Ambient Air Monitoring Network Plan, which describes the 

Alaska monitoring network for 2011-12. EPA has the following comments on this network plan. 

The primary change to the Alaska air monitoring network this year was the addition of the Fairbanks 

NCore monitoring site, which was supposed to be fully operation on January 1,2011. As oqhat 

date, only the required PM2.5 and meteorological monitoring equipment had been initiated. 

However, ADEC has provided adequate justification in its final plan explaining that some of the 

gaseous monitors at this site were not in operation until mid-September because of instrument 

problems requiring factory repair. Also, ADEC provided a description of the Fairbanks NCore site 

selection process in Appendix G of the plan, which explains why ADEC believes the site is properly 

located. EPA concurs with the selection of the Fairbanks NCore monitoring site. 

As requested by EPA, ADEC added a footnote in Appendix E that explains that the.2009 PM2.5 98 

percentile value, and the 2008-10 design value, provided in the tables for the Fairbanks State Office 

Building Site, are contingent on EPA concurring on the five high flagged exceptional event days for 

2009. 

The Municipality of Anchorage (MOA) will discontinue collection of a PM2.5 FRM monitor at the 

Garden site (AQS ID: 02-020-0018) after 06/30/11. MOA will continue collection of PM2.5 data at 

this site with an FEM BAM 1 020 monitor which is also designated as SLAMS for PM2.5. EPA 

approves this change. 

MOA replaced the primary PMIO FRM samplers (operating on a 1:3 frequency) at the Tudor site 

with a BAM 1020 operating continuously, in accordance with 40 CFR, Part 50, Appendix K, Section 

3.1 (f). EPA approves this change. 

MOA discontinued CO monitoring at the Turnagain site effective 03/31111. CO monitors will 

continue to operate at three other locations in Anchorage (the Garden, Parkgate, and DHHS sites). 

EPA approves this change. 

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The following monitors are designated "core" monitors because they are either: I) required by 40 

CFR Part 58, Appendix D; 2) have a design value near or above the new PM2.5 24-hour standard of 

35ug/m3 or; 3) they are essential monitoring parameters at NCore sites: 

1. 	 PM2.5 FRMs (or Approved Regional Method): 

a) Fairbanks (primary and secondary) 

b) Juneau 

c) Butte 

2. 	 PM2.5 speciation and precursor gas monitoring at the Fairbanks NCore site. 

"Core" monitors are those monitors in the network that must be operated with available PM2.5 

monitoring funds. The "non-core" PM2.5 monitors in the State's network can be operated at 

ADEC's discretion with any remaining federal funds or State funds. 

If you have any questions about our approval of the Alaska monitoring network, please contact Keith 

Rose at (206) 553-1949. 

Sincerely, 

Robert Elleman, Acting Manager 

State and Tribal Programs Unit 

cc: 	Chris Hall, OEA 

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