In terrestrial environments, the dominant fate of TCE released to surface soils is volatilization to the air. Because of its moderate water solubility, TCE introduced into soil has the potential to migrate through the soil into groundwater. The relatively frequent detection of TCE in groundwater confirms its mobility in soils. Biodegradation in soil and groundwater is thought to be slow (half-life on the order of monthsto years) Because of its high vapor pressure,TCE in the atmosphere is expected to be present primarily in the vapor phase rather than sorbed to particulates. Some removal by scavenging during wet precipitation is expected because of the moderate solubility of TCE in water (1.1 g/L). The major degradation process affecting vapor phase TCE is photo oxidation by hydroxyl radicals (half-life on the order of 1-11 days) The dominant fate of TCE released to surface waters is volatilization (predicted half-life of minutes to hours). Bioconcentration, biodegradation, and sorption to sediments and suspended solids are not thought to be significant