I think the issue with tailings ponds would be the hydrochemistry of the water and how that can mobilize certain heavy metals or trace constituents into the groundwater system. I think the release of water from these ponds becomes a major recharge event, and that water can enter into the system, contaminate these freshwater systems and cause toxic effects, I suppose, to the ecosystem that is being impacted.
The concern is with the situation of the hydraulics of this tailings pond. The nature and extent of that impact would be associated with both the quantity of the water and the water chemistry and all the reactions that are going to be happening along those transport pathways. Those can happen over multiple time and distance scales.