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  • 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…

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  • 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…

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  • 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.

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  • 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…

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  • What changes did EPA finalize to the SPCC Rule in December 2006?

    The revised rule modifies requirements for facilities with smaller oil storage capacity and specific types of oil-filled operating equipment. If a facility has 10,000 gallons or less in aggregate aboveground oil storage capacity and the facility meets the oil discharge history criteria, then an owner/operator of a facility may prepare…

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  • SPCC change in ownership

    If there is a change in ownership at a facility, can the facility operate under the same SPCC Plan without the certification from a professional engineer (PE)? If no change in procedures has been made, it may still be feasible to operate under the existing SPCC Plan. The information in…

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  • 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…

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  • Liability of oil retailers at SPCC regulated farm

    If a farm is out of compliance of Spill Prevention, Control, and Countermeasure (SPCC) regulations and is checked by EPA and/or has a spill, is the retailer that filled the tank liable? No, EPA considers the oil tank owner responsible for lack of compliance.

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  • 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…

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  • PE certifying a technical amendment

    Except as provided in 40 CFR §112.6 for qualified facilities, a Professional Engineer (PE) must certify all technical amendments to an existing SPCC Plan (§112.5(c)). When certifying a technical change to an existing SPCC Plan, does the PE have to inspect and certify the entire Plan or only the amended…

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  • 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…

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  • Is a PE required to review an SPCC Plan if it has not changed?

    Under the 2002 regulations, is a PE required to review the SPCC Plans at the end of a 5-year SPCC Plan cycle if no changes have occurred at the facilities? No. It is the responsibility of the owner or operator to document the completion of a review and decide whether…

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  • PE certifying an SPCC plan in a different state

    Except as provided in 40 CFR §112.6 for qualified facilities, a licensed Professional Engineer (PE) must review and certify an SPCC Plan for it to be effective to satisfy the requirements of Part 112 (§112.3(d)). When reviewing and certifying a facility’s SPCC Plan, must the PE be licensed in the…

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  • How did EPA amend the requirements for animal fats and vegetable oils in 2006?

    In December 2006, EPA removed the following SPCC requirements for the following specific types of animal fat and vegetable oil facilities: Requirements for onshore oil production facilities (Section 112.13) Requirements for onshore oil drilling and workover facilities (Section 112.14) Requirements for offshore oil drilling, production, or workover facilities (Section 112.15)…

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  • 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…

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