William D. Barber Jr., 53, a water pollution control and manpower management consultant who had worked for the Environmental Protection Agency since 1979, died of a heart attack Friday at Washington Hospital Center.

Mr. Barber went to work in 1954 as a field representative for Pennsylvania's Fair Employment Practices Commission. He later worked in urban renewal and redevelopment programs in Schuylkill and York, Pa., and was assistant executive director of the Pennsylvania State Employes Retirement System. From 1952 to 1963, he also operated a real estate business in York.

He then served as an urban and federal program coordinator for the Interior Department's Bureau of Outdoor Recreation in Pennsylvania for three years before moving to Washington in 1966 as chief of Interior's manpower development program in the old Federal Water Pollution Control Administration, now part of the EPA.

From 1971 to 1979, Mr. Barber lived in St. Thomas, V.I., where he was a special assistant to U.S. Virgin Islands governors Melvin Evans and Cyril King for about five years. He than established his own consulting firm on St. Thomas, International Business Associates, which he operated until returning to Washington last year as a full-time consultant on safety programs for farm workers for the EPA.

Mr. Barber served in the Army Air Forces on Guam from 1945 to 1947.

He graduated from Pennyslvania State University and earned a master's degree in political science from Stanford University.

He maintained homes here and in St. Thomas.

Survivors include his wife, Ann, and two sons, David and William III, all of St. Thomas; two other sons Richard of Pottstown, Pa., and Scott of Kansas City, Mo.; his father, William Sr. of Philadelphia; his mother Catherine Beasley, a brother, John, and a sister, Millie Green, all of Pottstown, and five grandchildren.