This is an interim program review of the Colorado River Basin Water Quality Control Project in progress. Organization and management of the project are presented. Accomplishments to date and work anticipated for the balance of the fiscal year with respect to each of the items are detailed in activity reports. Initially the principal emphasis of this project was placed on investigations related to pollution caused by uranium milling operations. Considerable engineering field work was devoted to this problem, and field activities were expanded to fill the requirements of the water quality management program and to examine existing nonradiological problem areas. These activities are described in detail. Salinity then became the most significant problem with respect to water quality of the Basin. At this point the project is estimated to be 35 percent completed. A bibliography of project reports and publications is included.