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  • 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.

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  • 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…

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  • 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…

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  • Secondary containment for oil-filled operation equipment under SPCC

    On December 26, 2006, EPA provided an optional alternative to the general secondary containment requirements in 40 CFR §112.7(c) for qualified oil-filled operational equipment ( 71 FR 77266 ). Because the alternative is optional, an owner or operator could choose to comply with the existing SPCC requirements to provide general…

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  • Can I leave my car or other vehicles on my property while I am away?

    The cleaning team will need workspace outside of your home or place of business to set up trailers and equipment. If it is determined that your vehicles need to be moved, you should arrange to temporarily remove them from your property.

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  • What happens to my belongings during the cleaning?

    The items you leave on your property and inside your home or place of business will remain where you left them and will not be removed.

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  • 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…

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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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  • 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…

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  • SPCC requirements for transfer areas associated with exempt USTs

    Gas stations typically are not subject to the SPCC Rule because completely buried storage tanks subject to 40 CFR Part 280 or 281 are exempt per §112.1(d)(4). However, a gas station would be subject to the SPCC Rule if it has more than 1,320 gallons of oil in aggregate above…

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  • Do the changes in the 2006 Amendments apply to oil-filled manufacturing equipment?

    No. The amendment does not change any requirements for oil-filled manufacturing equipment. Oil-filled manufacturing equipment remains subject to the SPCC requirements (including those for containment), but an owner/operator may determine that secondary containment is impracticable and comply with the alternative measures in section 112.7(d).

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  • What is an oil spill contingency plan?

    Instead of providing secondary containment for qualified oil-filled operational equipment, an owner or operator may prepare an oil spill contingency plan and a written commitment of manpower, equipment, and materials to quickly control and remove discharged oil. He/she must also have an inspection or monitoring program for the equipment to…

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  • Secondary containment requirements for mobile refuelers

    What secondary containment requirements apply to mobile refuelers? General secondary containment requirements in §112.7(c) still apply to mobile refuelers at SPCC regulated facilities. General secondary containment should be designed to address the most likely discharge from the container and from oil transfers into or from the mobile refueler. The general…

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  • What do I do with my indoor plants during the cleaning?

    You may leave plants on your property and inside your home or place of business. However, the cleaning team will not move any of your belongings, including plants. You may want to consider moving plants outside for the day, if possible, and watering them before you leave.

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