Allen Hazen

An American civil engineer, Allen Hazen was born in 1869 and died in 1930. He became one of the leading experts on water supply, filtration, and sanitation at a time when fast-growing cities were struggling to provide safe drinking water.

Hazen is especially remembered for his work on water purification and for the practical, measurement-based approach he brought to public health engineering. He advised major waterworks projects and wrote influential technical books and papers that helped define the field for decades.

His career reflects a moment when engineering could directly improve everyday life: cleaner water, safer cities, and better public health. That mix of scientific rigor and public service is why his name still matters in the history of environmental and civil engineering.