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Air Quality Program

Air Emissions Inventory

An air emissions inventory is a listing of the amount of air pollution emitted by various sources. Every year, Ecology and the local air quality agencies inventory large businesses.  Every three years, Ecology inventories many additional sources such as motor vehicles, woodstoves, outdoor burning, agricultural sources, and natural sources. Several inventory summaries are available for download below.


Large Business Annual Inventory

The large business inventory is a summary of individual facility inventories compiled by local air agencies and Department of Ecology offices. The agency or office responsible for each facility is noted in the downloadable spreadsheet. Contact the local air agency or Ecology office for questions and the most up-to-date information for individual facilities.

Washington Emissions Inventory Repository Database (WEIRD)

The Washington Emissions Inventory Repository Database (WEIRD) system was designed to capture the information that major (also known as AOP) sources are required to report annually. There are two versions of WEIRD: the training version and the production version. The training version of WEIRD will allow sources to get familiar with the system without affecting data that will be reported to Ecology. The production version of WEIRD allows sources to update the data for annual reporting. Helpful resources and links are available below.

Instructional Material:

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Comprehensive three-year inventory

The comprehensive three-year inventory was developed by the Department of Ecology. It includes the large business inventory and many other source types such as motor vehicles, woodstoves, outdoor burning, agricultural sources, and natural sources.

Large Business Prevention of Significant Deterioration (PSD) Modeling Inventory

The prevention of Significant Deterioration Inventory includes large businesses for the minor source baseline dates and the years 2005-2008. It also includes information for using the inventories in a PSD analysis.

Other Links

Do you have questions or need more detail?  Contact Us.


Download 2005 Large Business Emissions Summary

Large Business Emissions Inventory Assistance

Download 2005 Comprehensive Emissions Inventory Summary

Download PSD Modeling Inventory (ZIP File Format)

Small Business Assistance Links

PSD Permit Information

Air Operating Permits

Air Quality Data

Local Clean Air Agencies and Ecology Regional Offices