Radon and Tritium in Public Water Supplies East Land Quality Forum

1. Radon and Tritium in Public Water SuppliesEast Land Quality Forum

2. Contents • Regulations – water quality and radiation • Indicative Dose – broad screening including gross alpha and gross beta indicators • Tritium – man-made radionuclide contaminant • Radon – naturally occurring contaminant found in ground water sources

3. Regulation – • Radioactivity in drinking water • The Water Supply (Water Quality) Regulations 2016 • Regulation 6 details general sample monitoring requirements including radioactivity

4. Private water supplies

5. Regulations also ensure public water supplies undergo thorough risk assessments Outputs of these assessments determine sampling strategies for radioactivity Where there is little or no perceived risk then waivers for reduced regulatory sampling can be applied for Risk Assessments and Waivers

6. RIFE report • Annual report commissioned by the EA and other environmental and food protection bodies • Details current risk for UK radioactive sites: nuclear power stations, defence establishments, nuclear fuel processing sites and other industries • 1mSv/year limit for each site

7. East Anglia nuclear sites

8. TID (total indicative dose), gross alpha and gross beta TID is a measure of the radioactive dose in mSv/year Limit of 0.1mSv/year from drinking water Only measured if gross alpha or gross beta limits are exceeded Gross alpha and gross beta are indicators for levels of radioactivity concentration and are measured in Bq/l Gross alpha limit 0.1Bq/l Gross beta limit 1Bq/l Monitored at all of our WTWs at least once annually

9. Measuring TID Calculation that takes into account all radioactivity with the exception of radon found in drinking water. 0.1mSv represents a very low level of risk that would not give rise to any detectable adverse health effect (Guidelines for Drinking Water Quality, World Health Organisation, 4th Edition). Radiation dose received is a function of factors such as the type of radiation, the part of the body affected and the exposure pathway. 1Bq of radiation will not always deliver the same radiation dose, therefore indicative dose has been developed to take into account the differences between different types of radiation.

10. TID levels in the UK Mean annual dose from consuming drinking water in the UK was assessed as 0.017 mSv in 2016. The highest annual dose was estimated to be 0.019 mSvfor drinking water from the River Faughan, County Londonderry. Doses dominated by naturally occurring radionuclides. The annual dose from artificial radionuclides in drinking water was less than 0.001 mSv.

11. Tritium • Radioactive isotope of hydrogen • 1 proton and 2 neutrons Introduced into the Water Quality regulations in 2000 to monitor for man-made radioactive contamination Primarily used for monitoring nuclear site discharges but also for larger non-nuclear industrial premises and landfill sites Occurs naturally in rainwater, streams, rivers and lakes at concentrations normally in the range 1 to 4 Bq/l Water Quality regulations give limit of 100Bq/l for drinking water Monitored at all WTWs at least once annually

12. Tritium and landfill sites • Some of the highest tritium concentrations in the environment are seen near landfill sites (1300 Bq/l in 1998 at Milton Landfill in Cambridge) • Extremely variable concentrations linked to heavy rainfall • Tritium is used in self-illuminating devices (gaseous tritium light devices GTLDs) • Lack of other radioactive contaminants means the dose (mSv/year) is actually very low

13. Radon • Rn-222, Rn-220, Rn-219 • Naturally existing radioactive noble gas • Decay product of uranium • Introduced into Water Quality regulations 2016 • Limit of 100Bq/l for drinking water (instant remedial action required at 1,000Bq/l) • Dose pathway through inhalation rather than ingestion

14. Ricardo-AEA – radon hazard maps

15. 306 samples from 124 sites: 25 high risk 267 moderate risk 14 low risk UKWIR radon report

16. Ukradon.org

17. Thanks for listening