Date Issued: May 1990
                                                                  Revised: October 1998
SUBJECT:   Compliance for Gross Beta Particle Activity

SOURCE:    Greg Helms
Title 40 CFR, Section 141.26, sets forth provisions for the monitoring of radioactivity in
community water systems.  Section 141.26(b)(l) states that compliance for gross beta particle
activity may be assumed without further analysis if the average annual concentration of gross
beta particle activity is less than 50 pCi/1 and the average annual concentrations of tritium and
strontium-90 are less than 20,000 pCi/1 and 8 pCi/1 respectively, provided, that if both
radionuclides are present the sum of their annual dose equivalents to bone marrow shall not
exceed 4 millirems/year. According to Section 141.26(b)(l)(i), if the average annual gross beta
particle activity exceeds 50 pCi/1, an analysis of the sample must be performed to identify the
major radioactive constituents present and the appropriate organ and total body doses shall be
calculated to determine compliance with Section 141.26.  Are the constituents listed in Table B
of Section 141.25 the major constituents to be determined?


       No, any radionuclide found in the samples that are listed in CFR 141.25(a) and have body
       burdens listed in "Maximum Permissible Body Burdens...in Air  or Water for
       Occupational Exposure" (NBS Handbook 69 as amended August 1963, U.S. Department
       of Commerce) is considered a major constituent as specified in CFR 141.16(b).  While
       the constituents listed are most likely to occur,  "major constituents" refers to the specific
       radioactive constituents in the particular (or an equivalent) sample.