Search Frequent Questions

Displaying 1 - 15 of 71 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

• Underground Storage Tanks in SPCC Plans

  If a gas station that has less than 42,000 gallons completely buried oil storage capacity and no aboveground oil storage capacity installs a new aboveground tank with a capacity greater than 1,320 gallons, must the facility’s Spill Prevention, Control, and Countermeasure (SPCC) Plan address the underground storage tanks (USTs) in…

  • Last published: May 31, 2024

• Container capacity less than 55 gallons

  Do facilities need to consider containers that are less than 55 gallons for applicability under 40 CFR Part 112? No. The third column of page 47066 of the July 17, 2002 Preamble states that "You need only count containers of 55 gallons or greater in the calculation of the regulatory…

  • Last published: May 31, 2024

• Oil-filled equipment capacity

  When counting against the 1,320 aboveground storage capacity threshold, would operational storage of oil (such as in a hydraulic press) be used? Oil which is contained in equipment is required to be factored into the storage capacity for the facility even though the oil may be only used for ancillary…

  • Last published: May 31, 2024

• If your farm does not have fuel storage that will flow into US waters by a ditch, river, stream, or lake, do you have to prepare a SPCC Plan?

  No. EPA suggests you use a common sense approach. If one of your oil storage tanks leaks, and the spilled oil would not flow into navigable waters or adjoining shorelines, you do not have to prepare a Plan. Remember that you still have the responsibility to clean up any spilled…

  • Last published: June 5, 2024

• Ground water pathways related to reasonably expected to discharge

  The SPCC Rule applies to facilities that could reasonably be expected to discharge into navigable waters (40 CFR §112.2(a)). Does a facility need to consider ground water pathways when determining if a discharge of oil could reasonably be expected to reach navigable waters? Owners and operators should consider whether on-site…

  • Last published: June 5, 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

• SPCC responsibility for tanks on leased property

  What if I leased some parcels, and there are tanks already present? Am I responsible for these tanks? You could be. If you plan to use these tanks, make sure in your lease agreement, it states who is responsible for these tanks. If the lease does not state who is…

  • Last published: August 5, 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