Search Frequent Questions

Displaying 1 - 14 of 14 results

• 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

• Are the NO Values in the MOVES Output Files Actually NO (Molecular Weight 30), or is the NO Expressed as NO2 (Molecular Weight 46)?

  See More Frequent Questions about MOVES and Related Models . The NO values in all versions of MOVES2014 (and MOVES2010b) output files are expressed as NO2 (molecular weight 46). HONO and NOx are also expressed in terms of NO2.

  • Last published: July 10, 2024

• How can residents communicate with EPA about activities at the Norwood Landfill site?

  This EPA website ( www.epa.gov/norwood ) is dedicated to the investigations in the Norwood community. We encourage you to use the site and submit any questions you might have through the form that appears on the website. We also welcome any feedback you might have on the webpage.

  • Last published: February 19, 2025

• Where can residents get the most accurate and up-to-date information on the Norwood Landfill site?

  The www.epa.gov/norwood website is the site with the most accurate and up-to-date information regarding EPA’s investigations in the Norwood community.

  • Last published: February 18, 2025

• What is the Difference Between Extended Idling and Normal Idling? Is it Possible to get Distinct Idling Emission Output for any Vehicle Type? Can this be Done in the Emission Rate Mode, or only Inventory Mode?

  See More Frequent Questions about MOVES and Related Models . Extended idling is a distinct emission process defined as the overnight idling of long-haul trucks with sleeper cabs at truck stops and other locations during federally required downtime. During such idling periods, these engines experience unusual loads (televisions, air conditioning…

  • Last published: July 10, 2024

• How does MOVES Classify Light-Duty Trucks?

  See More Frequent Questions about MOVES and Related Models . There are two definitions used in MOVES for light duty trucks. The source use type light duty trucks (sourceTypeID values of 31 or 32) use the Federal Highway Administration (FHWA) VM-1 definition of light duty vehicles used to report vehicle…

  • Last published: July 10, 2024

• If I want to talk with EPA about sampling on my property or ask a specific question about my property, who should I contact?

  Please contact Katie Page, EPA Community Involvement Coordinator, at 215-814-2409 or [email protected] to ask any questions related to your property.

  • Last published: June 17, 2024

• What is the Relationship Between Calendar Year, Model Year, and Age?

  See More Frequent Questions about MOVES and Related Models . Model year (modelYearID) corresponds to the year that a group of vehicles in the fleet was produced. Calendar year (yearID) is the analysis year as selected in the ‘Time Spans/Year’ panel of the MOVES GUI. For a given calendar year…

  • Last published: July 10, 2024

• Why do mobile source NOx emissions jump higher between 2001 and 2002 on the emissions trends?

  The emissions model used for mobile sources changed from MOBILE6.2 to MOVES 2010 in December 2009. This change included a notable increase in NOx emissions. The EPA adjusted data back to 2002 to reflect the change in models. The higher emissions in 2002 are because of this method change and…

  • Last published: May 1, 2024

• What is the Meaning of the MOVESScenarioID Field? What Conditions Must User-Defined MOVESScenarioIDs Meet?

  See More Frequent Questions about MOVES and Related Models . The MOVESScenarioID is merely text that is used to label the output rows resulting from a MOVES rates run and is defined in the Scale Panel of the MOVES GUI. You can enter any text you like, as long as…

  • Last published: July 10, 2024

• How are the Number of Weekdays and Weekend Days in each Month Determined in MOVES?

  See More Frequent Questions about MOVES and Related Models . For any given month, MOVES assumes that 5 out of every 7 days in the month are ‘weekdays’ and 2 out of every 7 of days in the month are ‘weekend days.’ For example, MOVES assumes that January has (5/7)*31…

  • Last published: July 10, 2024

• What is Vehicle Specific Power (VSP)?

  See More Frequent Questions about MOVES and Related Models . It is an estimate of the power demand on the engine during driving. It is calculated using the second-by-second speed values in a driving schedule, along with information about the type of vehicle being operated. The VSP is used by…

  • Last published: July 10, 2024

• Why do the PM2.5 emissions for the electric utilities source category jump up between 1998 and 1999?

  The estimation method for PM emissions from fuel combustion sources was enhanced beginning with the 1999 National Emissions Inventory. Prior to 1999, the emissions measurement data methodology only included the filterable portion (which means the solid particle matter at elevated stack temperatures). Beginning with the 1999 NEI, both the filterable…

  • Last published: August 15, 2024