ABSTRACT
In dry climates where évapotranspiration exceeds precipitation, perchlorate may not migrate appreciably into the soil column and may redeposit at or near the soil surface. In these environments, water may not penetrate the soil column very far before it reverses course and moves upward due to evaporation and transpiration processes. When water evaporates or is transpired, the previously dissolved perchlorate salts are left behind in the shallow soil column.
