This report describes research on the fate and effects of carbon tetrachloride and FREON 113 (1,1,2-Trichloro, 1,2,2-Trifluorethane) released into the estuarine environment. Both compounds are rapidly released from the water to the air at rates controlled by turbulent diffusion in the surface water layers. Degradation processes are very slow compared to loss into the atmosphere. As the halocarbons were rapidly released to the air, average values were used for the experiments based on the high of addition and the loss between additions.