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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 does the Safe Drinking Water Act limit lead in pipes, plumbing fittings, fixtures, faucets, solder and flux?

    Answer: Section 1417 of the Safe Drinking Water Act (SDWA) establishes the definition for “lead free” as a weighted average of 0.25% lead calculated across the wetted surfaces of a pipe, pipe fitting, plumbing fitting, and fixture and 0.2% lead for solder and flux. The Act also provides a methodology…

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  • Is exposure to lead contaminated drinking water from absorption through skin a health threat?

    Answer: Human skin does not absorb lead in water. For more information visit our website: https://www.epa.gov/ground-water-and-drinking-water/basic-information-about-lead-drinking-water . Question (23002-32377) Find a printable PDF copy of all frequent questions pertaining to lead .

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  • Are non-transient, non-community water systems (NTNCWSs) required to monitor for lead and copper?

    Answer: All community water systems (CWSs) and NTNCWSs must collect lead and copper tap samples. The frequency of the monitoring and number of samples to be collected and analyzed is based primarily on the number of people served and tap water monitoring results. For an outline of monitoring requirements (e.g…

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  • Is there anything else I can do beyond flushing my tap or buying bottled water?

    Answer: Yes, find “Important Steps You Can Take to Reduce Lead in Drinking Water” if you are concerned about lead in their drinking water. The list is not intended to be exhaustive or to imply that all actions equally reduce lead from drinking water. EPA recommends you also contact your…

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  • My neighbors got their water tested and found lead. Is my water safe?

    Answer: Lead usually gets into drinking water through contact with plumbing materials such as lead pipes or lead solder, or faucets, valves, and fixtures made of brass (brass contains some lead). Since each home has different plumbing pipes and materials, test results are likely to be different for each home…

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  • Can one still sell lead solder under the Lead Ban?

    Answer: Section 1417(a)(3) of the Safe Drinking Water Act (SDWA) prohibits the sale of solder and flux that is not lead-free unless the solder or flux bears a prominent label stating that it is illegal to use the solder or flux in the installation or repair of any plumbing providing…

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  • Why do water systems add phosphate to drinking water? What are the health effects of drinking water containing phosphates? 

    Answer: Public water systems (PWSs) commonly add phosphates to drinking water to prevent the release of metals in drinking water. Orthophosphate is most commonly used for lead and copper control. Polyphosphates sequester iron and manganese to prevent discolored water but are not effective to control lead and copper. Blended phosphates…

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