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  • Criteria for selecting alternative release scenarios

    As part of the hazard assessment, owners and operators of Program 2 and Program 3 covered processes must identify and analyze alternative release scenarios (40 CFR §68.28). What criteria should be used when selecting an alternative release scenario? The owner or operator of a stationary source subject to the risk…

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  • What’s the difference between air sampling and air monitoring?

    Air monitoring and air sampling are two different methods of looking at air quality. Air monitoring uses electronic devices to provide real-time readings of contaminants in the air. Air sampling involves trapping air over a period of time in a container that is then sent to a laboratory for analysis…

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  • What is EPA’s role in sampling?

    EPA is part of the Unified Command consisting of different agencies to review, approve and direct Norfolk Southern’s workplans and site activities. Surface water sampling is performed by Norfolk Southern contractors, with EPA and Ohio EPA oversight. Soil sampling is performed both by Norfolk Southern contractors and EPA contractors. Air…

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  • Does the distance to endpoint start at the process or stationary source boundary?

    When selecting the worst-case release scenario for Program 2 and 3 processes as required by 40 CFR §68.25, a stationary source owner or operator must analyze the release scenario that results in the greatest distance to an endpoint. Does the "greatest distance to an endpoint" refer to the greatest total…

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  • Using meteorological station data for off-site consequence analyses

    For the purpose of the offsite consequence analyses required under 40 CFR Part 68, Subpart B, there are several instances in which data gathered at a local meteorological station may be used to establish the modeling parameters of wind speed, atmospheric stability, temperature, and humidity for the stationary source. How…

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  • Underground storage tank off-site impacts to groundwater, drinking water, or soil

    For the worst-case and alternative release scenarios of an underground storage tank, should I consider any impact on groundwater, drinking water, or soil? No. As part of the worst-case and alternative release scenarios, you need to define the offsite impacts to the environment (40 CFR §68.33) by listing the environmental…

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  • Administrative controls considered when determining worst-case release quantity

    For the purpose of analyzing the worst-case release scenario required as part of the hazard assessment at 40 CFR Part 68, Subpart B, the worst-case release quantity is identified as the greatest amount held in a single vessel or pipe, taking into account administrative controls that limit the maximum quantity…

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  • Are Mechanical Controls Considered Administrative Controls?

    For the purpose of analyzing the worst-case release scenario required as part of the hazard assessment at 40 CFR Part 68, Subpart B, the worst-case release quantity is identified as the greatest amount held in a single vessel or pipe, taking into account administrative controls that limit the maximum quantity…

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  • Worst-case release from smaller process with larger distance to endpoint

    The owner or operator of a stationary source covered by the risk management program regulations must conduct a worst-case release scenario analysis as part of the required hazard assessment (40 CFR §68.25). The worst-case release is defined as the release of the largest quantity of a regulated substance from a…

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  • Can I use any previous three year meteorological data for worst case scenario?

    I am trying to complete my worst case release scenario for the Risk Management Plan under §68.25. I understand that I am required to use a wind speed of 1.5 m/s and F atmospheric stability class as specified in §68.22(b), unless I can prove that at no time over the…

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  • What is the plume map and what does it tell us?

    The plume map is an “event reconstruction” based on known weather and on-site observations during a 10-hour time period after the vent-and-burn operation that occurred on Monday, February 6. It tells us where soot likely fell to the ground and where the highest concentrations of particles may be. This information…

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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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  • What is split sampling?

    Split sampling is a technique where multiple samples are collected from the same location at the same time and then sent to separate laboratories for analysis. Checking to see if the labs get the same or similar results is a way to determine the accuracy of the data. If there…

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  • What work happens after contamination under and between the train tracks is removed?

    After track work is complete, additional cleanup and assessments will continue. This includes shipping solid and liquid wastes off-site, excavating in areas where rail cars were staged and scrapped, and sampling and monitoring groundwater, soil, surface water, and sediment.

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  • How many worst-case release scenarios must be analyzed and documented in the RMP?

    As a part of the hazard assessment requirements in 40 CFR Part 68, Subpart B, I must analyze worst-case release scenarios and document certain analyses in my risk management plan (RMP). How many worst-case release scenarios must be analyzed, and how many analyses must be specifically documented in the RMP…

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