part_subject: "NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS"
subpart_code: "R"
subpart_subject: "National Emission Standards for Radon Emissions From Phosphogypsum Stacks"
section_number: "61.207"
section_subject: "Radium-226 sampling and measurement procedures."
cfr_reference: "40 CFR 61.207"
title_name: "Title 40"
title_subject: "Protection of Environment"
parts_covered: "Parts 61 to 62"
revised_date: "Revised as of July 1, 2019"
publication_date: "As of July 1, 2019"
contains_description: "Containing a codification of documents of general applicability and future effect"
publication_info: "Published by the Office of the Federal Register National Archives and Records Administration as a Special Edition of the Federal Register"
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(a)Before removing phosphogypsum from a stack for distribution in commerce pursuant to § 61.204, or § 61.206, the owner or operator of a phosphogypsum stack shall measure the average radium-226 concentration at the location in the stack from which phosphogypsum will be removed. Measurements shall be performed for each such location prior to the initial distribution in commerce of phosphogypsum removed from that location and at least once during each calendar year while distribution of phosphogypsum removed from the location continues.
(1)A minimum of 30 phosphogypsum samples shall be taken at regularly spaced intervals across the surface of the location on the stack from which the phosphogypsum will be removed. Let n
1 represent the number of samples taken.
(2)Measure the radium-226 concentration of each of the n
1 samples in accordance with the analytical procedures described in 40 CFR part 61, appendix B, Method 114.
(4)Calculate the 95th percentile for the distribution, x*, using the following equation:
(5)If the purpose for removing phosphogypsum from a stack is for distribution to commerce pursuant to § 61.206, the owner or operator of a phosphogypsum stack shall report the mean, standard deviation, 95th percentile and sample size. If the purpose for removing phosphogypsum from a stack is for distribution to commerce pursuant to § 61.204, the additional sampling procedures set forth in paragraphs (b) and (c) of this section shall apply.
1, <10 pCi/g and x* >10 pCi/g, the owner or operator may elect to follow the procedures for further sampling set forth in paragraph (c) of this section:
1 ≥10 pCi/g; phosphogypsum shall not be removed from this area of the stack for distribution in commerce pursuant to § 61.204.
(c)If the owner or operator elects to conduct further sampling to determine if phosphogypsum can be removed from this area of the stack, the following procedure shall apply. The objective of the following procedure is to demonstrate, with a 95% probability, that the phosphogypsum from this area of the stack has a radium-226 concentration no greater than 10 pCi/g. The procedure is iterative, the sample size may have to be increased more than one time; otherwise the phosphogypsum cannot be removed from this area of the stack for distribution to commerce pursuant to § 61.204.