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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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  • 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 defined as a structure (home or place of business)?

    While generally defined as a building, a structure under the structural cleaning program will include only those habitable spaces where indoor occupancy is frequent and regularly occurring on a daily or near-daily basis. Examples of residential structures include primary residences and living spaces, and examples of commercial structures include offices…

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  • Why is cleaning of homes and places of businesses happening?

    Norfolk Southern, with EPA oversight, is providing indoor cleaning to eligible occupants in response to concerns about the impact of the derailment and cleanup work on homes and places of businesses. The cleaning is to address potential dust that may have been generated as part of the train derailment and…

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  • What work still needs to be done at the derailment site?

    Although contaminated soil has been excavated and removed from the derailment site, some additional work remains. Soil sampling continues to check all areas where cleanup operations took place. Stream assessments continue, and culvert clean out has started. Groundwater and drinking water sampling also continues. Expect these investigations and possible additional…

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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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  • Identifying public receptors and property with restricted access

    Does public receptor cover only buildings on a property or the entire property? If the owner of the land next to my site restricts access to the land, is it still a public receptor? Public receptors are not limited to buildings. For example, if there are houses near your property…

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  • When to Revise OCA

    The risk management program in 40 CFR Part 68 requires facilities to conduct an off-site consequence analysis (OCA) to provide information to state, local, and federal governments and the public about the potential consequences of an accidental chemical release. When does a facility need to revise its OCA? The owner…

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  • No trespassing signs restricted access onsite or offsite public receptor

    The definition of public receptor is "offsite residences, institutions (e.g., schools, hospitals), industrial, commercial, and office buildings, parks, or recreational areas inhabited or occupied by the public at any time without restriction by the stationary source ..." Offsite is further defined to include "areas within the property boundary [of the…

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