Search Frequent Questions

Displaying 1 - 15 of 72 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

• Can MOVES Report Output in Terms of Fuel Consumption?

  See More Frequent Questions about MOVES and Related Models . Although gallons of fuel consumed are not reported by MOVES, the factors used to convert total energy consumption (a MOVES reporting option) to gallons of fuel are contained in the FuelSubtype table (energy content, reported in kilojoules per gram of…

  • Last published: July 10, 2024

• Is it required that the professional engineer conducting the engineering review must be licensed in the state in which the renewable fuel facility is located?

  See More Frequent Questions about Fuels Registration, Reporting, and Compliance Help . The licensed professional engineer should comply with the state laws where the renewable fuel facility is located to determine whether or not their license allows them to conduct business in that state.

  • Last published: July 23, 2024

• How do I use MOVES at Project Scale?

  See More Frequent Questions about MOVES and Related Models . The MOVES model can estimate emissions at national, county or project scale. Project scale is useful for estimating an individual transportation project like an intersection or transit project, but it requires detailed inputs that describing the vehicle population and activity…

  • Last published: August 2, 2024

• May records, regardless of whether they are paper or electronic, be stored off-site?

  See More Frequent Questions about Fuels Registration, Reporting, and Compliance Help . Yes. Refiners, oxygenate blenders and importers must indicate where records will be kept on all facility registrations.(7/1/94) This question and answer was originally posted at Consolidated List of Reformulated Gasoline and Anti-Dumping Questions and Answers: July 1, 1994…

  • Last published: August 2, 2024

• Is the licensed professional engineer conducting the engineering review required to perform the site visit in person, or can they delegate the site visit to another person who maybe assisting them in the engineering review?

  See More Frequent Questions about Fuels Registration, Reporting, and Compliance Help . Pursuant to §80.1450(b)(2), all verifications must be performed by the licensed professional engineer conducting the engineering review. This requirement includes conducting the site visits. The licensed professional engineer conducting the engineering review must perform the site visits to…

  • Last published: August 2, 2024

• In filing company and facility registrations, if a parent corporation has several subsidiary corporations it desires to register and report to EPA under one company ID number, would it be permissible to register all of the facilities operated by the subsi

  See More Frequent Questions about Fuels Registration, Reporting, and Compliance Help . In this situation the parent corporation should register for a company ID # and facilities operated by the subsidiary corporations should be registered as separate facilities but under the parent corporation's company ID #.(8/29/94) This question and answer…

  • Last published: August 6, 2024

• If my fuel is already registered with the Fuels and Fuel Additives program under 40 CFR Part 79, do I still need to register with the RFS2 program under 40 CFR Part 80?

  See More Frequent Questions about Fuels Registration, Reporting, and Compliance Help . Yes. Even if your fuel or fuel additive is already registered under 40 CFR Part 79, there are additional registration requirements for parties regulated under the RFS2 program, as specified in 40 CFR 80.1450.

  • Last published: August 14, 2024

• How Can I Determine the Effect of Speed on Vehicle Emissions?

  See More Frequent Questions about MOVES and Related Models . MOVES can be run in either “Inventory” or “Emission Rates” mode. With Emission Rates, MOVES reports emission rates for the 16 average speed bins used by MOVES for each hour of the day and additional emission rate output that may…

  • Last published: October 23, 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