Screening strategies for gross alpha activity and gross beta activity
3.—(1) A water undertaker may use a screening strategy for gross alpha and gross beta to monitor for the parametric indicator value for indicative dose.
(2) Subject to sub-paragraph (3) the recommended screening values are—
(a)0,1Bq/l for gross alpha activity; and
(b)1,0Bq/l for gross beta activity(1).
(3) If the gross alpha activity exceeds 0,1Bq/l or the gross beta activity exceeds 1,0Bq/l, analysis for specific radionuclides is required.
(4) The Welsh Ministers may set alternative screening levels for gross alpha activity and gross beta activity where it can be demonstrated by the water undertaker that the alternative levels are in compliance with an indicative dose of 0,1 mSv.
(5) The radionuclides to be measured must be based on all relevant information about likely sources of radioactivity.
Where appropriate, gross beta activity may be replaced by residual beta activity after subtraction of the K-40 activity concentration.