USE OF ATMOSPHERIC CONTAMINANTS TO ESTIMATE THE MINIMUM AGE OF CONTAMINANT RELEASES IMPACTING GROUND WATER: BACKGROUND AND THEORY

摘要

There are several anthropogenic contaminants present in the atmosphere that can be employed as time clocks for ground-water recharge. Contaminants, such as tritium (~3H) and chlorofluorocarbons (CFCs), have been used for decades to assess ground-water flow pathways and ages. Recently, contaminants such as krypton-85 (~(85)Kr) and sulphur hexafluoride (SF_6) have also been employed. These same methods can be applied to estimate the minimum release time frames for contaminants entering ground water and have been used successfully for discharges of petroleum products and chlorinated solvents. These methods can be employed to age date releases for virtually all types of contaminants.