7.—(1) Subject to paragraph 6(1), the recommended screening values are—
(a)0.1 Bq/l for gross alpha activity, and
(b)1.0 Bq/l for gross beta activity M1.
(2) If the gross alpha activity exceeds 0.1 Bq/l or the gross beta activity exceeds 1.0 Bq/l, analysis for specific radionuclides is required.
(3) The Secretary of State may set alternative screening levels for gross alpha activity and gross beta activity where it is demonstrated by the local authority that the alternative levels are in compliance with an ID of 0,1 mSv.
(4) The determination by the local authority of which radionuclides to measure must be based on all relevant information about likely sources of radioactivity.
Marginal Citations
M1Where appropriate, gross beta activity may be replaced by residual beta activity after subtraction of the K-40 activity concentration.