The objective of this project is to determine the survivability characteristics of the Human Immunodeficiency Virus (HIV) in wastewater collection and treatment systems. Research being conducted includes development of reliable methods to concentrate and assay the virus in wastewater during and after stages in its collection, transport and treatment. Preliminary work has indicated that the HIV is stable in the liquid fraction of non-chlorinated, secondary effluent from a conventional wastewater treatment plant for at least 24 hours with no reduction in infectivity. In this project, viral concentration will be performed using the bentonite adsorption-elution process with determination of the virus to be conducted by direct assay using the antigen capture test, and by measurement of infectivity. The Human Immunodeficiency Virus (HIV) has been found in body excretions from infected individuals. Wastes from infected individuals are typically discharged into wastewater collection and treatment systems where the survivability characteristics of the virus are presently not well established. Results of this research are expected to provide the basis for determination of any changes in the engineering design of collection and treatment systems that may be necessary for response to this potential threat to public health.