R 325.10603 Radionuclides; MCLs; applicability.

Rule 603. (1) Community water supplies, also known as "supplies" in this rule and R 325.10604, shall comply with the MCLs in this rule and compliance shall be determined under R 325.10604. (2) The MCLs for radionuclides are all of the following: (a) The maximum contaminant level for combined radium 226 and radium 228 is 5 picoCurries per liter (pCi/l). The combined radium-226 and radium-228 value is determined by the addition of the results of the analysis for radium-226 and the analysis for radium-228. (b) The maximum contaminant level for gross alpha particle activity, including radium 226, but excluding radon and uranium, is 15 pCi per liter. (c) Both of the following apply to the MCL for beta particle and photon radioactivity: (i) The average annual concentration of beta particle and photon radioactivity from man- made radionuclides in drinking water shall not produce an annual dose equivalent to the total body or any internal organ greater than 4 millirems per year. (ii) Except for the radionuclides listed in table 1 of this rule, the concentration of man- made radionuclides causing 4 millirems total body or organ dose equivalents shall be calculated on the basis of a 2-liter-per-day drinking water intake using the 168-hour data listed in the publication entitled "maximum permissible body burdens and maximum permissible concentration of radionuclides in air or water for occupational exposure," nbs (national bureau of standards) handbook 69, as amended August, 1963, United States department of commerce, which is adopted by reference in R 325.10112. If 2 or more radionuclides are present, then the sum of their annual dose equivalent to the total body or to any organ shall not be more than 4 millirem per year. Table 1 Average Annual Concentrations Assumed to Produce a Total Body or Organ Dose of 4 Millirem Per Radionuclide Critical organ pCi per liter Tritium Total body 20,000 Strontium-90 Bone marrow 8 (d) The maximum contaminant level for uranium is 30 micrograms per liter (ug/l).