This is agricultural runoff they are desalinating, right? I would've thought it is so full of other stuff that it would be too contaminated to extract salt. But

This is agricultural runoff they are desalinating, right? I would've thought it is so full of other stuff that it would be too contaminated to extract salt. But I don't know anything about the refining process so maybe it is feasible to get very pure salt even in the presence of contaminants.