A preliminary laboratory and modeling study on the environmental impact of ''in-situ''coal gasification field testing is reported. Experiments were conducted on the aspects of ground water pollution; water leaching, transport, and dispersion of pollutants. The major inorganic contaminants leached from the coal ash were determined to be Al/sup 3/, Ca/sup 2/, and OH/sup -/, while the principal organic pollutants were found to be phenols. A simple calculational model is used to predict the movement of the polluted ground-water. This model inputs information from laboratory experiments for the rate at which the above pollutants are removed from the gasification zone and the degree with which they are sorbed by the surrounding coal. It was discovered that ungasified coal has a strong beneficial effect on retarding the dispersion of the pollutants. The problem of air pollution resulting from the flaring of the production gas was also examined. The extent of the air pollution plume that develops from this flaring is predicted using a simple computer model. These predictions have been carried out for a set of atmospheric and flare operating conditions that may be encountered during field tests. It was determined that the LLL field experiments will adequately meet air quality standards, even under adverse conditions.