Search Frequent Questions

Displaying 1 - 15 of 56 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

• 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

• My neighbor is re-siding and re-roofing his house and there is material all over the ground. Do I need to be worried about asbestos exposure?

  Not all house siding or roofing materials contain asbestos. If you are concerned the material might contain asbestos, you can ask your neighbor whether or not the material has been tested for asbestos. Federal regulations regarding renovations or demolitions of asbestos-containing materials do not apply to a homeowner’s renovation of…

  • Last published: May 1, 2024

• How do I know if I have asbestos in my home (in floor tile, ceiling tile, shingles, siding, etc.)?

  The only way to be sure whether a material contains asbestos is to have it tested by a qualified laboratory. EPA only recommends testing suspect materials if they are damaged (fraying, crumbling) or if you are planning a renovation that would disturb the suspect material. Samples should be taken by…

  • 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

• Does EPA Actions apply to permits that are jointly issued by EPA and a state, tribal, or local permitting authority with partially delegated permitting authority?

  EPA regional offices will decide whether a permit that EPA jointly issues with a state, tribal, or local permitting authority should be considered for prioritization for enhanced outreach as described in EPA Actions on a case‐by‐case basis. EPA will take into account its role and authority in issuing the specific…

  • Last published: July 10, 2024

• Why doesn’t EPA do enhanced outreach for every permit?

  Robust public outreach and engagement can consume a substantial amount of resources from all stakeholders in a permitting process and would not be warranted for every permit action. EPA recognizes that its regional offices cannot enhance engagement for every EPA‐issued permit and that overburdened communities might be overwhelmed with process…

  • Last published: July 10, 2024

• How will an EPA regional office determine whether a permitted activity may have significant public health or environmental impacts?

  Permit applications provide information on the proposed project consistent with the requirements of particular statutes and regulations. EPA may also do its own assessment of the environmental and public health impacts of a proposed project, using modeling and monitoring data for example. Such information would inform an EPA regional office’s…

  • Last published: July 10, 2024