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Air emissions inventory summaries

Facilities that have an air operating permit must send their emissions data to us or local clean air agencies. We collect emissions data through the Washington Emissions Inventory Reporting System (WEIRS) to find out how much pollution is in our air and track the data.

Air emissions inventory

An air emissions inventory is an accounting of the amount of air pollution from various sources. Every year, local clean air agencies and Ecology inventory facilities with an air operating permit. This is called a point source inventory. Every three years, Ecology inventories many additional emission sources and issues a comprehensive three-year inventory.

Point source annual inventory

The point source annual inventory is a summary of individual inventories from facilities with an air operating permit. Maps of the most recent statewide point source emissions are listed below. Contact us or the appropriate local clean air agency for the most up-to-date information about individual facilities. Facilities with air operating permits must report annually.

Comprehensive three-year inventory

We publish a comprehensive three-year emissions inventory that includes a point source inventory and other emission sources such as vehicles, wood stoves, outdoor burning, agriculture, and natural sources. The latest summary data from the comprehensive emissions inventory as well as technical documentation are available in the documents below:

Prevention of Significant Deterioration modeling inventory

The Prevention of Significant Deterioration (PSD) permit program was developed to prevent significant environmental impacts to an attainment area (a location that meets federal air quality standards) from large industrial sources of air pollution. The Prevention of Significant Deterioration modeling inventory includes minor source baseline dates by county and modeling data for those years, as well as the most recent year's detailed emissions inventory data. This information is useful for those conducting a Prevention of Significant Deterioration analysis.