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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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  • 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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  • Where can I find the East Palestine City Park soil sampling results?

    You can find East Palestine City Park soil sampling results at: East Palestine City Park soil sampling results

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  • What were the results from the phase 1 of soil sampling?

    Phase 1 of soil sampling is complete, and we have received most of the preliminary data. The vast majority of results are within typical ranges for soil. Samples taken on private properties are all within typical soil levels, and only a few samples taken along public right-of-way (next to roads…

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  • What are the next steps?

    The sampling data will be evaluated to determine if additional sampling or other action is necessary (additional information will be made available soon). Evaluation of results and future sampling plans will guide EPA’s future work and environmental monitoring in the East Palestine area.

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  • How were soil sample locations chosen?

    The study area was determined based on evacuation zones, plume modeling, field observations, and areas most likely to be impacted by the vent and burn. Event Reconstruction Plume Map

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  • 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://ofmpub.epa.gov/sccwebservices/sccsearch/ .

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  • Where can I find soil sampling data and results?

    EPA will release validated (final) and non-validated (preliminary) soil sampling results from East Palestine and surrounding Ohio and Pennsylvania areas as they become available. As soon as the quality of non-validated preliminary data has been fully assessed and documented, EPA will post validated data on the East Palestine, Ohio Train…

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  • 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.

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  • What do the symbols and words on my water well sampling results mean?

    One common symbol on results is μg/L, which stands for microgram per liter. This indicates the mass of a chemical in one liter of water. Columbiana County Health District has a guide to help understand terms in well sampling results reports. You can find the guide at Columbiana Health Data…

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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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