The cause was complications after treatment for cancer, said his wife, Lynn Gutter.
Mr. Freudberg spent 40 years with COG, an organization of 24 local and municipal governments in the Washington area, before retiring in 2020 as deputy executive director.
He previously had been COG’s senior director of environment, homeland security, and health, as well as director of environmental programs.
“He brought data to the table,” said COG Executive Director Chuck Bean, adding that Mr. Freudberg knew the level of pollutants flowing into the river, what it would take to clean them up, what it would cost, and who should pay.
Stuart Alan Freudberg was born in Washington on Sept. 26, 1953, and grew up in Newton, Mass. His father was an engineer, and his mother was a librarian.
He graduated in 1974 from Rensselaer Polytechnic Institute in Troy, N.Y., and received a master’s degree in civil engineering from the Massachusetts Institute of Technology in 1977.
Mr. Freudberg’s first marriage, to Abby Mandel, ended in divorce. In addition to Gutter, his wife of 22 years, of Falls Church, Va., survivors include three sons from his first marriage, Daniel B. Freudberg of Arlington, Va., Michael S. Freudberg of Brooklyn, N.Y., and Adam L. Freudberg of Framingham, Mass.; his mother, Rita Freudberg of Auburndale, Mass.; a brother; a sister; and four grandchildren.
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