Regional Emissions Data and Analyses

WESTAR/WRAP supports state, local, and Tribal air agencies, federal land managers, and the US EPA by tracking emissions data and conducting technical analyses to inform understanding of current and emerging regional air quality issues in the West.

This regional effort focuses on fully characterizing emissions sources both within and beyond the WESTAR/WRAP region that impact Western air quality. Key activities include:

• Developing emissions data for all source sectors – domestic and international – to support air quality planning in the West, and supporting the collection and analysis of that data through projects such as Regional Haze;
• Analyzing baseline emissions, trends, and projection data;
• Evaluating control technologies and emissions reduction strategies;
• Tracking activity data and emissions from fires and biomass burning, and assessing their impact on ozone and particulate matter
• Coordinating with the EPA National Emissions Inventory to ensure consistency in emissions tracking.

To support these efforts, WESTAR/WRAP develops, maintains, and shares databases, supports technical analyses, and provides member agencies with access to data and results from various information sources to produce consistent, comparable, and complete results.

WESTAR/WRAP hosts a monthly Emissions Inventory (EI) call that brings together state, local and Tribal air agency EI staff to discuss EI issues of common concern, learn about EI data collection and estimation methods across various sectors, respond to emissions modeling platform data requests and data reviews, and foster collaboration and familiarity among EI programs across the western air agencies.

May  29th, 2025 – Presentation on Residential Wood Combustion Emissions Estimation Methods (Madeleine Strum & Rich Mason, EPA)

June 26th, 2025 – Meeting Recording

An Emissions Modeling Platform (EMP) is periodically developed to serve as a basis for national, regional, and local modeling for regulatory analyses and State Implementation Plan (SIP) development. EPA, multi-jurisdictional organizations (MJOs) like WESTAR/WRAP, state, local and Tribal air agencies participate in a collaborative effort to develop the 2022 EMP, which includes a 2022 baseyear and subsequent future years (tenatively 2026, 2032, and 2038). More information on this development can be found on the 2022 EMP wiki page, and EPA’s 2022 EMP page.