Frequent Questions

Can gross alpha particle activity analytical results be substituted for radium levels when determining compliance with the radium-226/228 standard?

Gross alpha particle activity results may be substituted for the required radium-226 levels when determining compliance, provided that the measured gross alpha particle activity does not exceed 5 pCi/L. If the gross alpha particle activity result is less than the detection limit, then one-half the detection limit (i.e., 1.5 pCi/L) is used for radium-226 and is added to the radium-228 activity. The combined radium-226/228 value must be used to determine compliance. If the gross alpha particle activity result is above the detection limit, compliance is determined using the whole gross alpha result (40 CFR 141.26(a)(5)).
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