This publication, an annual report to Congress, covers measures taken to implement the objectives of the Federal Water Pollution Control Act. The report was developed by the Environmental Protection Agency (EPA) and covers calendar year 1973. A letter introducing and highlighting the report from the EPA Director to the Congress is given at the beginning of the publication. The introduction describes the various federal, state and local government roles as well as the roles of industry and the public in water pollution control efforts in 1973. Other sections of the publication describe efforts in water quality, monitoring and planning, grants to state and local governments, regulation, water quality standards and effluent limitations, research and development, and efficiency of treatment works. Five appendices are included which describe enforcement actions pending or completed during 1973 that pertain to water pollution control legislation. (MR)