Skip to main content

The Combined Air Emissions Reporting (CAER) project seeks to consolidate reporting activities by creating a coordinated process for regulated entities to provide the latest facility attributes and emissions data only once. CAER relies on technology and collaboration to route the appropriate data to the relevant regulatory programs.


Various programs report air pollutant emissions using many approaches, forms, and definitions. This patchwork results in inefficiencies and unnecessary costs. In the proposed future state, the CAER project will reduce the cost to industry and government of consolidating and managing important environmental data.


  • Regulated Community: CAER will reduce reporting burden for facilities by avoiding duplicative efforts across programs and improving reporter experience through integrated electronic reporting and shared services
  • Public: CAER will improve the availability, timeliness, and transparency of data, while yielding higher quality and more consistent data for various users
  • Regulators: U.S. EPA, states, tribes, and locals will engage in timely decision-making and analyses with more consistent, accessible, and high-quality air emissions data


The most recent Research and Development projects under CAER Phase II included:

  • Creating a compendium of state-specific emission factor information
  • Enhancing data-sharing between programs


In the coming year the team will start building the “Common Emissions Form” through a pilot. This will serve as a tool for combined reporting. The team will seek a state to collaborate in this endeavor. The pilot will be a steppingstone toward a “Minimum Viable Product” that the team hopes to complete within two years. While not containing the full suite of capabilities envisioned for the common form, the product will be usable by piloting state facilities.


For more information, please visit the CAER Project Website. To join the CAER listserv, send an email to


State/Local/Tribal (SLT), National Emission Inventory (NEI), Toxic Release Inventory (TRI) Mapping

Research consistency and possible workflows for sharing of emissions data between TRI, SLTs and NEI. This will include creating a crosswalk for pollutants between programs, figuring out how to handle each program’s terminology (e.g. facility, unit) and emission sources covered by reporting, and identifying where guidance needs to be harmonized, among other things.

Phase 1 – Final Report

TRI/NEI Pollutant Crosswalk

Quality Assurance / Quality Control (QA/QC)

Identification and evaluation of a common set of emissions data QA/QC procedures for potential use in a shared emission reporting system.

Phase 1 – Final Report

Data Model for the Common Emissions Form (CEF)

Document a data model with the emissions-related data elements needed to support a common emission form (CEF) reporting structure in a shared emissions platform. Identify and include state-specific data elements sufficient to allow for broad usage by states and EPA CAER

Phase 1 – Final Report

Appendix A – Data Model Survey Results

Appendix B – Additional Pollutants

Appendix C – Additional Data Fields

SCC-WebFIRE for the Common Emissions Form (CEF)

Scoping study for identifying problems and solutions with SCCs and WebFIRE that will meet SLT, NEI, NATA, and CEDRI/ERT requirements under the CAER project.

Phase 1 – Final Report

State Greenhouse Gas Reporting Program (GHGRP) to National GHGRP Mapping

This will be a pilot study to map emission data in the national GHGRP to state GHGRP programs. The goal of the study is to understand which data elements state mandatory reporting programs have in common with GHGRP required data elements. This will help us understand what would be necessary to share data between the programs.

Phase 1 – Final Report

Appendix A – GHG PDT Dad Element Comparison