Retired Navy Lt. Cmdr, Benjamin Groundwater, 72, a veteran of World War II and the Korean conflict and a communications specialist with RCA here until his retirement in 1971, died of congestive heart failure Sunday at the Woodbine Nursing Home in Alexandria.

Cmdr. Groundwater enlisted in the Navy in 1928. In 1933, he joined the Navy Security Group Headquarters here and worked in specialized communications. During World War II, he served on the staffs of the Pacific and Asiatic fleets and was stationed at Pearl Harbor at the time of the Japanese attack there in 1941. He received his commission after Pearl Harbor.

During the Korean conflict, he served in the Far East. He also served in Europe before returing to the Naval Security Group here in 1957. He retired in 1958 and went to work for RCA.

A native of Scammon, Kan., he attend Kansas State Teachers College. He also attended the Corcoran School of Art here.

He and his wife, Ethel, a former Washington Post nurse, established their home in Arlington in 1943.

Cmdr. Groundwater was a member of the Cherrydale Methodist Church in Arlington. He also was a member of the Retired Officers Association.

In addition to his wife, he is survived by a daughter, Carol G. Preston, of Falls Church, a son Robert B., of Birmingham, Ala., and three grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the Benjamin Groundwater Memorial Fund, Cherrydale Methodist Church, Arlington.