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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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  • Redoing calculations if RMP*Comp is updated

    Will RMP*Comp be updated? If so, would I have to redo calculations I might already have made with an earlier version? No, you do not have to redo your work if you have already completed your consequence analyses. RMP*Comp is based on the EPA's Offsite Consequence Analysis Guidance (OCA Guidance)…

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  • Different distances to toxic endpoints with different versions of RMP*Comp

    I've noticed that for certain chemicals, RMP*Comp gives substantially different distances to the toxic endpoint than previous versions. Why? In the current version of RMP*Comp, we have incorporated new chemical-specific distance tables for ammonia, chlorine, and sulfur dioxide. The generic tables are still used for other chemicals (you can see…

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  • Distance to endpoint calculations used by RMP*Comp

    Does RMP*Comp perform some math or modelling in order to arrive at an endpoint distance, or is it simply interpolating from the tables in the EPA's Offsite Consequence Analysis Guidance (OCA Guidance)? RMP*Comp follows the procedures set out in the OCA Guidance . This means that for some scenarios, the…

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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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  • Are biogenic emissions included in the emissions trends Tier 1 data?

    No, the biogenic emissions are not included in the emissions trends Tier 1 data. If needed, users can add the biogenic data either as a separate Tier, or specify its inclusion in the “Miscellaneous” Tier 1 group.

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  • How do I get access to the Emissions Inventory System?

    Access to the Emissions Inventory System (EIS) is available to state, local, tribal agencies, their representatives (such as contractors), to multijurisdictional organizations (MJOs), and to EPA staff. The EIS is not available to the public. Instructions for access to the EIS is available in the Emissions Inventory System (EIS) User’s…

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  • What sources make up the Sectors or Tiers used in the emissions data summaries?

    Tier 1 and Sector 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 and Sector assignments can be downloaded from the EPA SCC website in Comma Separate Values (CSV) format.

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  • RMP*Comp and emergency response

    Can I use RMP*Comp for emergency response? No. It's a planning tool. Many other tools are available for response, including ALOHA . You can learn more by reading CAMEO tools for RMP .

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  • Minimum and Maximum Distance to Endpoint

    The Chemical Accident Prevention Provisions require the completion of a worst-case release scenario analysis (40 CFR §68.25). This analysis includes estimating the greatest distance to endpoint as defined by the parameters in §68.22. Is there a required minimum or maximum distance for the distance to endpoint in the worst case…

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  • Where can I obtain the hourly data from Continuous Emissions Monitors (CEMs)?

    The CEM emissions data are available from the EPA Clean Air Markets Program Data website.

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  • How can I get more detailed information? What measurements/sensors are used to measure emissions?

    Access the latest NEI data set . Under 'Sector Summaries - Criteria and Hazardous Air Pollutants by 60 EIS emission sectors', > choose National > for Pollutant, choose PM10 Primary and/ or PM2.5-PRI > Sector, choose all sectors >Submit Query to see results at bottom of page. Open the results…

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  • Local meteorological data for alternative release scenarios

    For alternate release scenarios, RMP*Comp uses set values for meteorological conditions like humidity, wind speed, temperature, stability class, and so on. Is there a way to change those values? I want to use meteorology data from my own location. RMP*Comp indeed uses fixed values for certain atmospheric parameters, and does…

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  • Different results using ALOHA and RMP*Comp

    I tried running the same scenarios in ALOHA and in RMP*Comp. I got different answers. Why? The results you obtain using RMP*Comp may not closely match the results you obtain running the same release scenario in a more sophisticated air dispersion model such as ALOHA or DEGADIS. That's because of…

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  • How do I reset my password for the Emissions Inventory System?

    Instructions for resetting your password are available in the Emissions Inventory System (EIS) User’s Manual and How To’s section on “How Do I Update My Password?” Follow the instructions to reset your password.

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