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Data and Tools

National Air Quality: Status and Trends of Key Air Pollutants

EPA sets national air quality standards for six common air pollutants. Each year EPA tracks the levels of these air pollutants in the air. EPA posts the results of our analyses to this web site.
Ozone W126 Index

The impact of ozone exposure on trees, plants and ecosystems often is assessed using a seasonal index known as a "W126 index."
Lead NAAQS Review: Comparison of Numbers/Percents of Sites/Counties/Populations That are Not Likely to Meet Various Potential NAAQS Levels Using Various Averaging Times and Forms

Technical memo showing comparisons of various potential naaqs levels
Exceptional Events Documents PM2.5 - Plumas Co.

Exceptional Events Documents PM2.5 - Plumas Co.
Analysis relating the W126 metric and the annual 4th highest daily maximum 8-hour concentration metric (Nov 20, 2014 technical memorandum)

This memo provides the results of a technical analysis which examines the relationship between the 4th max metric and the W126 metric based on ambient air quality from 2001 to 2013.
Lead NAAQS Review: Comparison of Numbers/Percents of Sites/Counties/Populations That are Not Likely to Meet Various Potential NAAQS Levels Using Various Averaging Times and Forms

This is the memorandum documenting analyses to support the lead NAAQS review.
Best Communication Practices for Preparation of Exceptional Event Demonstrations

OAQPS developed this document of Best Practices based on input received from EPA regional offices and selected state/local air agencies who submitted Exceptional Event Demonstrations under the 2007 version of the Exceptional Events Rule (EE Rule).
Public Notice of Exceptional Events - Uinta Basin of Utah

This page contains an announcement of public comment for exceptional events in the Uinta Basin of Utah, along with a technical support document containing details.
One Point Quality Control Single Point Precision and Bias Graphics For Criteria Pollutants

This document defines the elements displayed in the corresponding box and whisker graphics as
well as base assumptions of the data contained within the AQS AMP256 report.
Exceptional Events Documents PM2.5 - Montana

Exceptional Events Documents PM2.5 - Montana
Exceptional Events Documents PM2.5 - Lindon, UT

Exceptional Events Documents PM2.5 - Lindon, UT
Exceptional Events Documents PM2.5 - Plumas and Shasta Cos. series 2

Exceptional Events Documents PM2.5 - Plumas and Shasta Cos. series 2
Exceptional Events Documents PM2.5 - Plumas and Shasta Cos. series 1

Exceptional Events Documents PM2.5 - Plumas and Shasta Cos. series 1
Exceptional Events Documents PM2.5 - Kona, Hawaii

Exceptional Events Documents PM2.5 - Kona, Hawaii
Exceptional Events Documents PM10 - Silverbow Co., MT

Exceptional Events Documents PM10 - Silverbow Co., MT
Exceptional Events Documents Ozone - Wyoming

Exceptional Events Documents Ozone - Wyoming
Exceptional Events Documents Ozone - Kansas

PDF documents associated with ozone exceptional events for Kansas City, Wichita, and Topeka areas, KS.
Exceptional Events Documents Ozone - Sacramento County, CA

PDF documents associated with ozone exceptional events for Sacramento County, CA.
Exceptional Events Documents PM2.5 - Granite City, IL

PDF documents associated with PM2.5 exceptional events for Granite City, IL.
Exceptional Events Documents Particulate Matter - Klamath Falls, OR

Exceptional Events Documents Ozone - Washoe, Nevada