[Loler]

Hello everyone,

This is more of a geochemistry question, but I'm sure someone might be able to help. I am very sorry if I posted this topic in the wrong section, a moderator can move it if necessary.

I have calculated saturation indices for a newly engineered system to see what minerals the groundwater might be in chemical equilibrium with. The data was collected 1 year after construction was completed.

I have found that the groundwater in the system was saturated with respect to dolomite and calcite, but I am not sure how to interpret this. Theoretically, this finding indicates that the groundwater is in chemical equilibrium with solid dolomite and calcite. But does this not indicate that the minerals are present in the aquifer? I find it hard to believe that dolomite and calcite can precipitate out in such a short period of time, especially in a system with lots of moving water. I don't think they were present initially, so the minerals did not dissolve to reach equilibrium. The calcium and magnesium would come from the sulfate salts that are in the matrix of the engineered aquifer, their dissolution results in the release of magnesium and calcium.

My thinking is it is just by chance that activities are in the right combination for calcite and dolomite to be saturated, and that the minerals are not actually contributing to the water. Does this make sense?