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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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  • 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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  • Quantity of a regulated substance in an aqueous solution

    When using RMP*Comp to conduct an offsite consequence analysis (OCA), a facility must specify the quantity released. What quantity should be entered for a regulated toxic substance in an aqueous solution, the total quantity of the aqueous solution or just the quantity of the toxic substance? The entire quantity of…

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  • Must I anticipate a specific cause for the worst-case scenario for a toxic substance?

    When analyzing the worst-case scenario for regulated toxic substances, must I anticipate a specific cause (e.g., fire, explosion, etc.) of the scenario? No. The worst-case analysis for a release of regulated toxic substances must conform to specific assumptions as identified in § 68.25(c) and (d). Anticipated causes of the release…

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  • Flammable event with different time duration

    What if a flammable event has a different time duration than the 5 kw/m2 for 40 seconds? EPA recognizes that flammable events may occur for a different amount of exposure time. Therefore, the owner or operator should determine the distance to an equivalent exposure - e.g. if the flammable event…

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