Groundwater Geochemistry of the Nanaimo Group in the Yellow Point and Gabriola Island areas

1. Groundwater Geochemistry of the Nanaimo Group in the Yellow Point and Gabriola Island areas

2. Environment Ministry evidence for elevated fluoride levels Malaspina well-water sampling program was initiated in 2000

3. Focused on Yellow Point and Gabriola Island areas because they showed some particularly high levels, and are close to Nanaimo. ~ 100 wells at Yellow Point (2000) ~ 75 wells on Gabriola (2001)

4. gabriola map

5. mudstone units sandstone units

6. anion diagram mudstone units sandstone units

7. Proportion of water samples with fluoride levels above the MAC (maximum acceptable concentration)Yellow Point ~13%Gabriola ~8%

8. RDN Landfill Observation well data Upperand lower samples at multi-piezo-meter sites

9. landfill Ca

13. representative n.g. g-waters

14. CaCO3 + CO2(g) + H2O = Ca2+ + 2HCO3- • According to the Le Chatelier principal, a decrease in the Ca content (because Ca is being removed from the water and adsorbed onto clays) will drive this reaction to the right, increasing the bicarbonate level, and resulting in a higher pH. This is base-exchange softening.

15. Outcrop sampling at Yellow Point and Gabriola owen drilling

16. f-b for rocks mudstone units sandstone units

17. ph-f

18. ca-f

19. na-f

20. so4-f

21. cl-f

22. b-f