Joseph Zwerdling, 76, who retired in 1979 as chief administrative law judge of the Federal Energy Regulatory Commission and was a past president of the Federal Trial Examiners Conference, died of a heart ailment July 25 at Suburban Hospital. He lived in Kensington.

Judge Zwerdling began his career as an administrative law judge in 1964, with the old Federal Power Commission. He stayed on the bench with the new FERC. During the Kennedy Administration, he was a member of the President's Administrative Conference of the United States and helped formulate guidelines for the conduct of administrative judges.

He was active in a number of civic and community groups in the Silver Spring area. In the early 1960s, he had helped lead a campaign to oppose construction of high-rise buildings and to build a library. He was a founder of the Daleview Community Swimming Pool.

Judge Zwerdling was a native of Ann Arbor, Mich., and received undergraduate and law degrees from the University of Michigan. Before World War II, he was an assistant attorney general of Michigan.

He moved to the Washington area after wartime Army service. He was a lawyer with the Justice Department's office of alien property and worked for the Office of Price Stabilization before joining the Federal Power Commision

Survivors include his wife, Alice G., of Kensington; two sons, Dr. David Zwerdling of Silver Spring, and Daniel Zwerdling-Rothschild of Chevy Chase; a daughter, Judith Zwerdling Zwelling of Williamsburg, and eight grandchildren.

JAMES R. HENNESSEY, 69, a retired Air Force Department criminal investigator and former special agent with the Federal Bureau of Investigation, died July 25 at his home in Lanham. He had cancer.

He worked for the Air Force office of special investigations from 1952 until retiring for health reasons in 1976. Before joining the OSI, he had served with the FBI for 13 years. In addition to its Washington Field Office, he had worked for the bureau in New York, Norfolk and North Carolina.

Mr. Hennessey, who had lived here since the mid-1940s, was a native of Ansonia, Conn. He was a graduate of Benjamin Franklin University.

He was a member of the Ex-Agents of the FBI, the Ex-OSI Officers, the Criminal Investigators Association, the College Park Moose lodge and the Andrews Air Force Base Officers Club. He was a member of St. Bernard's Catholic Church in Riverdale.

Survivors include his wife, Dorothy, and a son, James Jr., of Lanham; a daughter, Susan Madison of Rockville, and a sister, Gertrude Cooke of Ansonia.

EMIL A. PRESS, 82, a retired chief of the planning division of the old D.C. Department of Sanitary Engineering who later worked for Deleuw Cather & Co., a Washington engineering firm, died of Parkinson's disease July 25 at the Wisconsin Avenue Nursing Home.

Mr. Press was a native and resident of Washington. He graduated from McKinley Technical High School and George Washington University. He joined the D.C. government during the 1920s. He retired in 1965 and became a consultant with Deleuw Cather. He retired a second time in 1975.

He was a member of the American Society of Civil Engineers, the Washington Board of Trade, the Columbia Historical Society and Phi Sigma Kappa Fraternity.

Survivors include his wife, Eleanor Ashe Press of Washington; one son, Donald Press of Springfield; one daughter, Alice Press of Denver; one brother, William H. Press of Washington, and three granddaughters.

WALTER BENJAMIN SANDERSON SR., 95, who was a D.C. police officer for 26 years before retiring in 1950 as a private, died July 22 at his home in Annapolis. He had cancer.

Mr. Sanderson was was a native of Wilcox County, Ala. He was a 1912 graduate of the Knoxville College in Tennessee and served in the Army during World War I. He came to Washington in 1913 and moved to Annapolis in the late 1960s.

He was a member of the Northeast Presbyterian Church in Washington and had attended Cecil Memorial United Methodist Church in Annapolis. He had been a member of the Pigskin Club, had served as an officer of several Washington-area PTA groups, and had been awarded an honorary sergeant's badge by the D.C. police.

His first marriage, to the former Yale Scott Manning, ended in divorce. Survivors include his wife, the former Sophia Johnson of Annapolis; three children by his first marriage, Vera L. Thomas of Columbus, Ohio, Walter B. Jr., of Washington, and John G., of Annapolis; six grandchildren, and six great-grandchildren.