ARSD 74:51:01:17. Analysis for dissolved gross beta radioactivity

Where alpha emitters, strontium-90, radium-228, iodine-129, iodine-130, and lead-210 are known to be a negligibly small fraction of the specific concentration limit in surface waters of the state, analyses for dissolved gross beta radioactivity, excluding any potassium-40 contribution, may be employed to monitor and show compliance with §§ 74:51:01:14 to 74:51:01:16, inclusive, except for tritium, if the gross concentration does not exceed 100 pCi/L. If these conditions are not met, quantitative analyses of individual radionuclides shall be performed to show compliance. Except in cases where tritium from other than natural sources are known to be absent, tritium analyses shall be performed to show compliance.