Antarctica has been a site of human activity for many years. With an increasing emphasis on environmental health and safety issues, the United States Antarctic Program is supporting research activity in these areas. This grant will investigate the sewage effluent plume and the persistence of bacteria associated with human wastes from McMurdo Station. Both chemical and biological indicators will be used to determine the sewage plume characteristics. The persistence of the bacteria will be investigated both in the field and laboratory experiments. The information obtained from this investigation will provide baseline data as a basis for assessing the impact of McMurdo Station's sewage effluent on the environment, and to determine whether further microbiological studies are necessary.