Treatment of Data Influenced by Exceptional Events
Exceptional Events are unusual or naturally occurring events that can affect air quality but are not reasonably controllable using techniques that tribal, state or local air agencies may implement in order to attain and maintain the National Ambient Air Quality Standards.
Contact: Mark Evangelista
Evangelista.Mark@epa.gov
(919)
541-2803
Background
The Environmental Protection Agency (EPA) finalized a rule to establish criteria and procedures for use in determining if air quality monitoring data has been influenced by exceptional events. The rule:
- ensures that air quality measurements are properly evaluated and characterized with regard to their causes,
- identifies reasonable actions that should be taken to address the air quality and public health impacts caused by these types of events,
- avoids imposing unreasonable planning requirements on state, local, and tribal air quality agencies related to violations of the NAAQS due to exceptional events, and
- ensures that the use of air quality data, whether afforded special treatment or not, is subject to full public disclosure and review.
Examples of Reviewed Exceptional Event Submissions
These documents are examples of exceptional event submissions, or the decision documents responding to the demonstrations, for various cases of exceptional events. The purpose of this table is to provide examples of Exceptional Event demonstrations that have been reviewed by EPA. This table is not intended to serve as a database for all Agency actions on exceptional events. These examples may help agencies develop demonstration packages submitted in support of requests for data exclusion due to influence of Exceptional Events; however, they may not contain the minimum level of data or case-specific analyses necessary for any other exceptional event demonstration.
Please note that not all concentrations addressed in the demonstrations in this table may have resulted in EPA concurrences.
PM2.5 |
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| Event | Agency | Location | Available Documentation |
| Summer 2008 Wildfires (series 2) |
California ARB | Plumas and Shasta Cos. | Shasta-Plumas demonstration series 2 (8/28/09) (ZIP, 463 KB) EPA response letter (4/02/10) (PDF, 53 KB) EPA technical support document (3/30/10) (PDF, 1.5 MB) |
| Summer 2008 Wildfires (series 1) |
California ARB | Plumas and Shasta Cos. | Shasta-Plumas demonstration series 1 (8/28/09) (ZIP, 900 KB) EPA response letter (3/11/10) (PDF, 60 KB) EPA technical support document (3/11/10) (PDF, 1.5 MB) |
| Summer 2007 Wildfires | California ARB | Plumas Co. | Plumas demonstration (6/17/09) (ZIP, 29 MB) EPA response letter (3/11/10) (PDF, 60 KB) EPA technical support document (3/11/10) (PDF, 980 KB) |
| July 2008 Fireworks | Illinois EPA | Granite City, IL | Granite City demonstration (6/17/09) (ZIP, 603 KB) EPA response letter (7/24/09) (PDF, 225 KB) EPA technical support document (7/24/09) (PDF, 443 KB) |
| Summer 2007 Wildfires | Montana DEQ | Multiple locations across Montana | MT DEQ demonstration (12/14/07) (PDF, 43 MB) |
| July 2007 Wildfire | Utah DEQ | Lindon, UT | Lindon demonstration (12/24/2007) (PDF, 3 MB) EPA response letter (4/29/08) (PDF, 612 KB) |
| July 2007 Fireworks | Utah DEQ | Rose Park, UT West Valley, UT |
Rose Park demonstration (12/24/2007) (PDF, 895 KB) West Valley demonstration (12/24/2007) (PDF, 877 KB) EPA response letter (4/29/08) (PDF, 612 KB) |
PM10 |
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| Event | Agency | Location | Available Documentation |
| August 2007 Wildfires | Montana DEQ | Silverbow Co., MT | MT DEQ demonstration (12/14/07) (PDF, 43 MB) EPA response letter (8/18/08) (PDF, 758 KB) EPA technical support document (8/18/08) (PDF, 272 KB) |
Ozone |
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| Event | Agency | Location | Available Documentation |
| Summer 2008 Wildfires | California ARB | Sacramento County, CA | CARB demonstration (3/30/11) (ZIP, 80 MB) EPA response letter (4/13/11) (PDF, 92 KB) EPA technical support document (4/13/11) (PDF, 238 KB) |
Publicly Available Support Information and Tools
EPA provides no endorsement of specific publicly available tools, nor does EPA mandate their use.
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