Search Frequent Questions

Displaying 1 - 15 of 59 results

• Where can I find older NEI data (prior to 2008)?

  The raw data and summaries that are still available (dating back to 1990) can be obtained from the web page https://www.epa.gov/air-emissions-inventories/pollutant-emissions-summary-files-earlier-neis . Starting with 2001 data, a more limited selection of summary files are available.

  • Last published: March 18, 2024

• How do the different parts of particulate matter (PM) fit together?

  The various parts of PM in the NEI are related as follows. PM10-FIL > PM25-FIL because PM10-FIL includes PM25-FIL PM25-PRI = PM25-FIL + PM-CON This equation only applies at the process level. Because some sources only can report PM2.5 (due to test method differences), this equation does not apply to…

  • Last published: April 17, 2024

• How does PM2.5 relate to PM species such as EC, OC, SO4, NO3, PMFINE, and DIESEL-PM25?

  Primary PM2.5 estimates are speciated into the five PM species in the NEI: elemental (black) carbon (EC), organic carbon (OC), nitrate (NO3), sulfate (SO4), and the remainder of PM25-PRI (PMFINE). Diesel engine PM25-PRI and PM10 emissions are also labeled as DIESEL-PM25 and DIESEL-PM10 for mobile source diesel engines. For all…

  • Last published: April 17, 2024

• What is the definition of “overburdened community” that is relevant for EPA Actions and Promising Practices?

  EPA Actions and Promising Practices apply the description of overburdened communities articulated in EPA’s Plan EJ 2014. The term is used to describe the minority, low‐income, tribal and indigenous populations or communities in the United States that potentially experience disproportionate environmental harms and risks due to exposures or cumulative impacts…

  • Last published: July 10, 2024

• How will an EPA regional office determine whether a permitted activity impacts a potential overburdened community? What screening tool or process will EPA regional offices use to screen permit applications?

  The Agency has developed a nationally consistent screening tool to help identify communities that are potentially overburdened. This tool, known as EJSCREEN, is one of several tools being developed under Plan EJ 2014. EPA anticipates that its regional offices will use EJSCREEN and other readily available information, including known community…

  • Last published: July 10, 2024

• Some of the Promising Practices are mentioned in EPA regulations, guidance and recommendations that EPA has issued in the past. So why is EPA issuing the Promising Practices?

  EPA is issuing Promising Practices to encourage permit applicants to strategically plan and conduct enhanced outreach to overburdened communities in the permitting process. As some commenters noted, EPA has recommended some of the outreach strategies included in Promising Practices previously. Nevertheless, EPA believes that it is important to issue Promising…

  • Last published: July 10, 2024

• Where can I download hourly emissions data from continuous monitoring?

  Hourly emissions data files are available from the Clean Air Markets Division of EPA, collected as part of 40 CFR Part 75. The download location has changed in February, 2023. The new location is https://campd.epa.gov/data/bulk-data-files . Once on this new site, use the menu (at the left) and the Keyword…

  • Last published: January 7, 2025

• What sources make up the Tier 1 categories used in the emissions trends?

  Tier 1 categories are assigned by source classification codes (SCCs) that are the most specific processes available in the NEI. The latest SCC list with the Tier 1 assignments can be downloaded from the EPA SCC website in Comma Separate Values (CSV) format.

  • Last published: May 1, 2024

• What is the cause of the large decrease in electric utility emissions, particularly sulfur dioxide, starting in 1995?

  SO2 emissions reductions from utilities during this time are primarily attributed to the impacts of the acid rain program. As described on EPA’s Acid Rain Program web page, Phase 1 of this program began in 1995 and affected 263 units at 110 most coal-burning electric utility plants in 21 eastern…

  • Last published: May 1, 2024

• Can I get access to the Emissions Inventory System if I am not a data provider to EPA?

  The Emission Inventory System (EIS) is a secured database for EPA and State/Local and Tribal Air Agencies only. The EIS is used to develop the National Emission Inventory (NEI). While you cannot have access to EIS, you can have access to the current and past NEIs through EPA’s NEI website…

  • Last published: May 28, 2024

• Are permit applicants required to adopt the Promising Practices?

  EPA is not requiring permit applicants to adopt the Promising Practices. Promising Practices are simply that: good ideas in the form of suggestions to permit applicants. Permit applicants may benefit from applying these Promising Practices. EPA hopes that when permit applicants practice early and meaningful dialogue with the community, they…

  • Last published: July 10, 2024

• EPA Actions does not require EPA regional offices to prioritize the same types of permits and adopt the same outreach activities. Why doesn’t EPA require regional offices to always prioritize certain permits and always do certain outreach activities?

  EPA Actions strikes an important balance between national consistency and regional flexibility. The Agency‐wide guidelines establish national consistency by providing EPA’s expectations for the regional implementation plans. At the same time, EPA recognizes that the regional offices need the flexibility to take actions suited to the types of permits and…

  • Last published: July 10, 2024

• Do EPA Actions or the Promising Practices in the Federal Register notice apply to permits that are issued by state, tribal, or local permitting authorities, or just permits that are issued by EPA?

  EPA Actions and Promising Practices apply only to permits that are issued by EPA. It does not apply to permits issued by state, tribal or local governments under authority delegated by EPA. By addressing environmental justice in its permits, EPA is leading by example among federal departments and agencies. EPA…

  • Last published: July 10, 2024

• If permit applicants are not required to adopt the Promising Practices, why should a permit applicant adopt them?

  EPA hopes that the practices described will persuade those who are new to these ideas to experiment with this form of leadership. Indeed, engaging with their communities as described in Promising Practices is consistent with many permit applicants’ core values. These principles, practices and values lead to corporate sustainability, stability…

  • Last published: July 10, 2024

• Are tribal and indigenous communities within the definition of overburdened communities?

  Tribal and indigenous communities are included in EPA’s definition of overburdened communities under Plan EJ 2014. For nearly thirty years, EPA has worked with federally recognized tribal governments on a government‐to‐government basis as sovereigns, partners, and co‐regulators. EPA has also worked with indigenous communities to address their environmental and health…

  • Last published: July 10, 2024