Environmental engineer John Henry Austin, 75, a Washington native who worked to improve water supplies and sanitation systems around the globe, died of colon cancer Aug. 17 at his home in Arlington.

During more than 20 years with the U.S. Agency for International Development, Dr. Austin helped develop public health projects to provide clean water and sanitation systems to the developing world. He was a professor at four universities and conducted training programs in sanitation and public health in many countries.

"He was a giant in those fields," said Dennis Carroll, an infectious disease specialist and USAID colleague. "The regard in which he was held internationally was quite remarkable."

At a 75th birthday celebration for Dr. Austin in February, engineers from Europe, Africa, Asia and South America came to Washington to pay tribute to his career.

He had been a professor of civil engineering at Colorado State University since 1993, and the university allowed him to remain in Washington as a full-time technical adviser to USAID's Bureau of Global Health. He retired in March and stayed on as a part-time consultant until his death. He received the bureau's lifetime achievement award in May.

In 1998 and 1999, Dr. Austin worked with the governments of Nicaragua and the Dominican Republic to develop sanitation and hygiene projects after hurricanes. In 1993, he helped design projects to improve water quality in Russia.

He worked on public water projects in Jordan, Egypt, Sri Lanka and Jamaica and developed sanitation projects in South Africa and Mozambique. He also helped devise standards for controlling pollution in Thailand.

Born and raised in Washington, Dr. Austin was a graduate of Anacostia High School. He graduated from Syracuse University, received a master's degree in sanitary engineering from Massachusetts Institute of Technology and studied in Delft, the Netherlands, on a Fulbright scholarship. He received a doctorate in sanitary engineering from the University of California at Berkeley in 1963.

He began his career with the U.S. Public Health Service in Cincinnati in 1955. From 1957 to 1959, he worked in Vietnam with a U.S. team to modernize the country's water supply. He taught at the University of Illinois from 1963 to 1969, when he went to Clemson University in South Carolina as head of the department of environmental systems engineering.

In 1977, Dr. Austin was named visiting professor at the University of Maryland. He was vice president of Maxima Corp., a Silver Spring environmental contracting firm, from 1978 to 1981, when he began his career with USAID.

He lived in Silver Spring from 1976 to 1983, when he moved to Arlington. He was a member of the Unitarian Universalist Church of Arlington.

Dr. Austin had many outside interests and adventures, beginning as a teenager when he worked on a ship transporting horses to Poland, replenishing animals killed during World War II. He later spent a summer with an international team rebuilding an Italian town's water system.

A dedicated mountaineer in his youth, he once climbed the Matterhorn. Another time, after his guide was seriously injured in the Wyoming Tetons, Dr. Austin climbed down a mountain in the dark to summon help.

In later years, he organized hikes on Virginia's Skyline Drive. A devoted bird-watcher, he was always on the lookout for birds in his travels.

While in high school, he played baritone horn in the Washington Redskins marching band. A week before his death, Dr. Austin attended an appreciation day for the football team and was especially pleased to see the latest incarnation of the Redskins band.

His marriage to Marilyn A. Austin ended in divorce.

Survivors include his wife of 12 years, Rita Klees of Arlington; four children from his first marriage, Eric Austin of Lexington, Mass., Kirstin Austin Kirkpatrick of Silver Spring, Shawn Austin of Burbank, Calif., and Bryn Austin of Boston; two sisters, Nan Doggett of Myersville and Mary Ann Harlan of Staunton, Va.; and six grandchildren.

John Austin helped provide clean water to the developing world.