I have a problem with my project and I was hoping I would find some clarification.
I did some modeling with phreeqc to calculate saturation indices and found that calcite was saturated in an engineered aquifer. The time of sampling of groundwater was roughly 1 year after construction was completed. Gypsum is present in the aquifer, so there are high calcium concentrations. However, I don't think the mineral calcite is actually forming insitu. I think the concentrations of calcium and carbonate are just at the right combination to be in equilibrium with calcite, so it is not actually contributing to calcium concentrations. I should add that the pH of the aquifer is between 7-8. I just don't think any sufficient quantities of calcite would form in a system with lots of water moving through it.
Is this a correct interpretation?