After attending the Phillips Academy, he studied civil engineer at the Massachusetts Institute of Technology, where he graduated in 1887.
[2] Waldo had started his career as chief engineer of the water works of Lincoln, Massachusetts in 1868 at the age of 17.
[2] In 1890 Waldo joined E. Jersey Water Company, where he became assistant of Clemens Herschel.
"[3] From 1903 to 1905 he was chief engineer in the aqueduct commissioner of New York, where he assisted in the completion of the construction of the New Croton Dam.
In 1918 Waldo was awarded the honorary Doctor of Engineering from the Stevens Institute of Technology.