Search Frequent Questions

Filter By:

Active filters:

Remove all filters

Displaying 1 - 15 of 16 results

  • 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:

  • 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:

  • How do the changes in the 2006 Amendments apply to mobile refuelers?

    Mobile refuelers are now exempt from the following sized secondary containment provisions that still apply to all other bulk storage containers and mobile/portable bulk storage containers: • Sections 112.8(c)(2) and (11) for petroleum oils • Sections 112.12(c)(2) and (11) for animal fats and vegetable oils These provisions previously required sized…

    • Last published:

  • Why Doesn't my Output Vehicle Miles Traveled (VMT) Match my Input VMT?

    See More Frequent Questions about MOVES and Related Models . This problem usually occurs when the run specification does not include all possible vehicle and fuel types. MOVES internally allocates the input VMT to each of the source types and fuel types and only reports the VMT for the fuel…

    • Last published:

  • What does MOVES Assume for Future Year Fleet Fuel Efficiency and Emissions?

    See More Frequent Questions about MOVES and Related Models . MOVES reflects all fuel economy and emissions standards that were final as of the model release date. For a list of recent regulations accounted for in the most recent MOVES version, see the see the Overview of EPA’s Motor Vehicle…

    • Last published:

  • SPCC Rule schedules for inspections, tests, and evaluations

    The SPCC rule requires inspections, tests, and evaluations of above ground containers (40 CFR §112.8(c)(6)). Does the rule set schedules for how often these need to be conducted? The SPCC Rule does not prescribe a specific frequency or methodology for performing the required inspections, evaluations, and tests for aboveground containers…

    • Last published:

  • Are mobile refuelers exempt from integrity testing requirements?

    Pursuant to 40 CFR §112.8(c)(2), mobile refuelers are exempt from the secondary containment requirements for bulk storage containers. Are mobile refuelers also exempt from the requirements for integrity testing in §112.8(c)(6)? Since mobile refuelers are mobile or portable bulk storage containers, the other provisions of §112.8(c) still apply. Therefore, mobile…

    • Last published:

  • Why Are There No Emissions for the Early and Late Hours of the Day for Certain Source Types?

    See More Frequent Questions about MOVES and Related Models . MOVES has no start emissions for the certain source types in certain hours of the day. While we know that a non-zero number of these source types do start late at night, our activity data on these trucks and buses…

    • Last published:

  • What does an annual emissions value in the NEI represent (one year or multiple years)?

    The NEI provides total annual emissions for a single year.

    • Last published:

  • What is included in the emissions “Tiers”?

    The Tiers are assigned by a Source Classification Code (SCC), which has the most detail about the emissions processes that generate the emissions. The full list of SCCs, their associated Tiers, and the SCC descriptions is available online at https://sor-scc-api.epa.gov/sccwebservices/sccsearch/ .

    • Last published:

  • How does MOVES Calculate CO2 and CO2 Equivalent Emissions?

    See More Frequent Questions about MOVES and Related Models . MOVES calculates the energy it takes to operate an onroad vehicle based on energy consumption rates as explained in the technical reports Greenhouse Gas and Energy Consumption Rates for Onroad Vehicles MOVES3 (pdf) (November 2020, EPA-420-R-20-015) and Exhaust Emission Rates…

    • Last published:

  • What are the units of NEI emissions data?

    NEI emissions values represent total annual emissions for the inventory reporting year. Criteria air pollutants and precursors (CAPs) are reported in short tons per year , and hazardous air pollutants (HAPs) are reported in lbs per year .

    • Last published:

  • What Pollutants are Included in “oxides of nitrogen” in MOVES?

    See More Frequent Questions about MOVES and Related Models . The definition of NOx in MOVES (NO + NO2 + HONO) is different than the standard NOx definition of NOx (NO + NO2). This change has been made to correct the exhaust NOx emission in MOVES for potential interference with…

    • Last published:

  • What Drives Seasonal CO Emission Trends?

    See More Frequent Questions about MOVES and Related Models . Once a vehicle’s engine/catalyst reaches operating temperature, the ambient temperature has little effect on the emissions performance of the vehicle. These “running” emission rates in MOVES have no temperature adjustment. However, during summer months at warm temperatures, MOVES assumes extensive…

    • Last published:

  • What does "NEC" stand for in the emissions sectors?

    NEC means “not elsewhere classified” and includes SCCs that are not assigned to any of the other specific industrial process sectors. If you look at the SCC code table available at the SCC web site and filter on the Sector name that includes “NEC”, you can see the type of…

    • Last published: