# The Water Supply (Water Quality) Regulations 2016, Paragraph 2: Screening for certain radionuclides or for an individual radionuclide


(1) If one of the activity concentrations exceeds 20% of the corresponding derived value or the tritium concentration exceeds its parametric value listed in Schedule 2, an analysis of additional radionuclides is required.
(2) In deciding which radionuclides are required to be measured for each supply, a water undertaker must take into account all relevant information about likely sources of radioactivity.

---
Source: https://www.legislation.gov.uk/uksi/2016/614/schedule/4/paragraph/2 (the official version)
Page: https://openlegislation.uk/water-supply-water-quality-regulations-2016/schedule-4/paragraph-2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.