RECEIVED 

STATE OF IDAHO 

DEPARTMENT OF 

ENVIRONMENTAL QUALITY 

SEP 3 0 Z013 

1410 North Hilton • Boise, Idaho 83706 • (208) 373-0502 

September 23, 2013 

Kate Kelly, Director 

Office of Air, Waste and Toxics 

USEP A, Region 10 

Mail Drop OA WT -107 

1200 Sixth A venue 

Seattle, WA 98101 

Dear~ 

Offk:e of Air, waste & Toxlcs 

C.L. "Butch" Otter, Governor 

Curt Fransen, Director 

The Idaho Department of Environmental Quality (DEQ) submits the enclosed 

documentation for data exclusion flagging and EPA concurrence as Exceptional Events 

for monitored values at the Boise and Nampa Idaho PM10 monitors. Those monitors 

were affected by a natural, regional dust transport event originating outside the state of 

Idaho on February 15 and 16, 2011. This documentation was prepared in accordance with 

requirements of the March 22, 2007 Final Rule, Treatment of Data Influenced by 

Exceptionai Events, Federal Register VoL 72, No. 55. 

DEQ has flagged in AQS, the values shown in the attached table and their respective 

AQS/POC identifiers. 

Monitor Site: 

Monitor ID (AQS#/POC): 

Date 

2/15/2011 

2/16/2011 

Boise Fire Station No. 5, 

Ada County, Idaho 

16-001-0009 (POC 3) 

Nampa Fire Station, 

Canyon County, Idaho 

16-027-0002 (POC 2) 

PM10 Concentration Recorded, ~g/m3 

183 174 

156 108 

Note: DEQ is not seeking concurrence on the February 16th value for the Nampa Fire Station (108 gt ). 

As required, all data were flagged prior to July 1, 2012 with "RJ" and for "high wind dust 

event." 

Accompanying this letter is the supporting documentation describing the event and 

demonstrating that the event meets all the Exceptional Event Rule (EER) criteria: 

(a) affects air quality (AAQ); (b) is not reasonably controllable or preventable (nRCP), 

(c) is a natural event or is an event caused by human activity that is unlikely to recur at a 

Prrnred .,, Rec)'•rea Papf!r 
particular location (NEIHAURL); (d) that there is a clear causal relationship (CCR) 

between the identified source and measurement under consideration; (e) that the event is 

associated with measured concentrations in excess of normal historical fluctuations (HF), 

including background; and (f) that there would have been no exceedance or violation of 

the standard but for the event (NEBF). DEQ also documented that prompt public 

notification procedures and measures to reduce public exposure were followed and that 

the public comment process was followed in reviewing the demonstration. 

In addition, the attached document (Request for EPA Concurrence as Exceptional Events 

for the February 15- 16, 2011, High Wind P M10 Dust Event Affecting High P M10 

Concentrations at the Boise Fire Station, Ada County and Nampa Fire Station, Canyon 

County, Idaho) was made available to the public for a 30-day public comment period, and 

no comments were received. 

DEQ would appreciate your review of the enclosed documentation and notification of 

EPA's determination of concurrence or non-concurrence to these flagged data within 60 

days as required in the Exceptional Event Rule. 

If you have questions or need additional information please contact Bruce Louks at 

(208) 373-0294, or me at (208) 373-0552. Thank you for your attention to this matter. 

Sincerely, 

loy 

Administrator, Air Quality Division 

Idaho Department of Environmental Quality 

Enclosure 

cc: Debra Suzuki, EPA Rl 0 Air Planning Unit Manager (no enclosure) 

Justin Spenillo, EPA RIO 

Chris Hall, EPA Rl 0