1. Technologies for Radon & Radionuclide Removal Tom Sorg U. S. Environmental Protection Agency

2. Radon Rn Radium Ra Uranium U Radionuclides

3. Radioactive Element in the Uranium 238 decay series Decay product of Ra 226 Alpha emitter Half life of 3.8 days Radon - 222

4. Rn 222 3.8 days Po 218 3 min Pb 214 27 min Bi 214 20 min Po 214 1.6x10 -6 sec Pb 210 20 years Radon - 222

5. Gas Naturally occurring ground water contaminant Proposed MCL - 300 pCi/L MMM Program - 4000pCi/L (AMCL) Radon - 222

6. Aeration (BAT) 70 - 99 % GAC 80 - 99 % Radon Removal Technology

7. Packed tower 90 -99 % High performance PP90 - 99% Diffused bubble70 - 99 % Tray80 - 90 % Spray80 - 90 % Mechanical surface>90 % Aeration Technology

8. GAC 80 - 99 % High EBCT requirements Potential radiation exposure problems Potential waste disposal problems GAC Technology Very Small Systems/ POU/POE

9. Ra 224 Thorium series Alpha emitter Half life of 3.6 days Ra 226 Uranium series Alpha emitter Half life of 1620 years Radium

10. Ra 228 Thorium series Beta emitter Half life of 6.7 years Radium

11. Cation Ra +2 Naturally occurring ground water contaminant Current MCL - 5 pCi/L (Ra 226 + Ra 228) Radium

12. Chemistry is similar to calcium and magnesium (hardness elements) Radium

13. Cation Exchange 65 - 95 % Lime Softening 80 - 95 % Membrane Processes 90 - 99 % Selective Complexers 97+ % Radium Removal Technology

14. Cation Exchange - Selectivity Sequence Ra +2 > Ba +2 > Ca +2 > Mg +2 > Na +2 > H +2 Hardness can be used as a surrogate measurement of radium breakthrough Radium Removal Technology

15. U 238 Uranium series Alpha emitter Half life of 4.5x10 9 years U 234 Uranium series Alpha emitter Half life of 2.5x10 5 years Uranium

16. U 235 Actinium series Alpha emitter Half life of 7.1x10 6 years Uranium

17. Cation/Anion/Neutral depending on pH Naturally occurring ground water contaminant Current MCL - none Proposed MCL in 1991 20 ug/L 30 pCi/L Uranium

18. Uranium in Water Chemical Forms pH < 2.5 Cation - UO 2 + pH < 2.5 - 7 Neutral - UO 2 (CO 3 ) 0 pH 7 - 10 Anion - UO 2 (CO 3 ) -2 - UO 2 (CO 3 ) -4

19. Coagulation/Filtration 80 - 95 % Lime softening 85 - 99 % Anion Exchange 90 - 99 % Activated Alumina 90 - 99 % Membrane processes90 - 99 % Uranium Removal Technology

20. Anion Exchange - High U capacity Treat 10k -100k bed volumes Capacity sulfate dependent Uranium Removal Technology

21. Cation /Anion Exchange System Ra 100 -1500 BVs U 10k -100k BVs Adjust amount of cation / anion resin Optimum mixture - 10 % anion 90 % cation Uranium + Radium Removal Technology

22. Gross Alpha, Beta Particle & Photon Emiters MCLs Gross alpha - 15 pCi/L (including Ra 226) Beta particle & photon emitters - 4 mrem/year

23. Gross alpha Reverse osmosis Beta particle & Ion Exchange photon emitters Reverse Osmosis Gross Alpha, Beta Particle & Photon Emiters BAT

24. SUMMARY Radon, radium & uranium are naturally occurring contaminants usually occurring in ground water.

25. SUMMARY - RADON Aeration and GAC are effective treatment technologies for radon. Of the two technologies, only aeration will be listed as a BAT and likely be the technology of choice in almost all cases. GAC will likely be considered for only very small systems and for POU/POE.

26. SUMMARY - RADIUM All technologies effective for hardness removal are generally effective for radium removal. Cation exchange, lime softening and reverse osmosis are the technologies currently being applied for radium removal.

27. SUMMARY - URANIUM Most conventional technologies have some capability for uranium removal. Anion exchange has been successfully applied for uranium removal from small ground water systems.

28. Tom Sorg USEPA Cincinnati, OH 45268 513-569-7370 sorg.thomas@epa.gov