RECEIVED ST

A TE OF I DAHO DEPARTMENT OF ENVIRONMENTAL QUALITY 

### SEP 3 0 Z013

1 410 No rth Hi lton • Boise , Idaho 83706 • (208) 373-0502 September 23, 2013

Kate Kelly, Director Office ofAir, Waste and Toxics USEPA, Region 10 Mail Drop OA WT-107 1200 Sixth Avenue Seattle, WA 98101

# Dear~ Offk:e of Air, waste & Toxlcs

C

. L. " Butch" Otter, Governo r Curt Fransen , D irector

The Idaho Department ofEnvironmental 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 ofthe 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) PM 10 Concentration Recorded,**~g/m 3** 

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 Except ional 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!rparticular 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 ofnormal 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 EventAffecting High P 

### M10 Concentrations at the Boise Fire Station, Ada County andNampa 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 ofthe enclosed documentation and notification of EPA's determination ofconcurrence or non-concurrence to these flagged data within 60 days as required in the Exceptional Event Rule. Ifyou 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 ofEnvironmental Quality Enclosure

cc: Debra Suzuki, EPA Rl0 Air Planning Unit Manager (no enclosure) Justin Spenillo, EPA RIO Chris Hall, EPA Rl0