Allen Hazen (August 28, 1869 – July 26, 1930) was an American civil engineer and an expert in

hydraulics Hydraulics () is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counterpart of pneumatics, which concer ...

flood control Flood management or flood control are methods used to reduce or prevent the detrimental effects of flood waters. Flooding can be caused by a mix of both natural processes, such as extreme weather upstream, and human changes to waterbodies and ru ...

, water purification and

sewage treatment Sewage treatment is a type of wastewater treatment which aims to remove contaminants from sewage to produce an effluent that is suitable to discharge to the surrounding environment or an intended reuse application, thereby preventing water p ...

. His career extended from 1888 to 1930, and he is, perhaps, best known for his contributions to hydraulics with the Hazen-Williams equation. Hazen published some of the seminal works on

sedimentation Sedimentation is the deposition of sediments. It takes place when particles in suspension settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to their motion through the fluid in response to th ...

and

filtration Filtration is a physical separation process that separates solid matter and fluid from a mixture using a ''filter medium'' that has a complex structure through which only the fluid can pass. Solid particles that cannot pass through the filte ...

. He was President of the New England Water Works Association and Vice President of the

American Society of Civil Engineers The American Society of Civil Engineers (ASCE) is a tax-exempt professional body founded in 1852 to represent members of the civil engineering profession worldwide. Headquartered in Reston, Virginia, it is the oldest national engineering soci ...

Early life and education

Hazen was born in 1869 on his family farm located near the

Connecticut River The Connecticut River is the longest river in the New England region of the United States, flowing roughly southward for through four states. It rises 300 yards (270 m) south of the U.S. border with Quebec, Canada, and discharges into Long Isl ...

close to the small town of Norwich, Vermont. He attended the New Hampshire College of Agriculture and Mechanical Arts (which was affiliated with

Dartmouth College Dartmouth College ( ) is a Private university, private Ivy League research university in Hanover, New Hampshire, United States. Established in 1769 by Eleazar Wheelock, Dartmouth is one of the nine colonial colleges chartered before the America ...

) and graduated with a Bachelor of Science degree at 15 years of age.Brown, Edward S. (1995). “The Hanover Water Works Company: One Hundred Years of Service.” ''Dartmouth College Library Bulletin.'' April

/ref>Hall, Ellen L. “Hydraulics in the Golden Age of Sanitary Engineering: The Life of Allen Hazen.” Presented at the Darcy Memorial Symposium on the History of Hydraulics. Philadelphia, PA. June 23-6, 2003

During a year spent at MIT (1887–88), Hazen studied chemistry and came into contact with Professor William T. Sedgwick, Dr. Thomas M. Drown and fellow students George W. Fuller and George C. Whipple.

Career

As a direct result of his association with Dr. Thomas M. Drown, Hazen was offered his first job at the Lawrence Experiment Station in Lawrence, Massachusetts. LES was likely the first institute in the world devoted solely to investigations of water purification and sewage treatment. From 1888 to 1893, Hazen headed the research team at this innovative research institute into water purification and

Hydraulics and dams

Hazen is most widely known for developing in 1902 with Gardner S. Williams the Hazen-Williams equation which described the flow of water in pipelines. In 1905, the two engineers published an influential book, which contained solutions to the Hazen-Williams equation for pipes of widely varying diameters. The equation uses an empirically derived constant for the “roughness” of the pipe walls which became known as the Hazen-Williams coefficient. In 1908, Hazen was appointed by President

Theodore Roosevelt Theodore Roosevelt Jr. (October 27, 1858 – January 6, 1919), also known as Teddy or T.R., was the 26th president of the United States, serving from 1901 to 1909. Roosevelt previously was involved in New York (state), New York politics, incl ...

to a panel of expert engineers to inspect the construction progress on the

Panama Canal The Panama Canal () is an artificial waterway in Panama that connects the Caribbean Sea with the Pacific Ocean. It cuts across the narrowest point of the Isthmus of Panama, and is a Channel (geography), conduit for maritime trade between th ...

with President-elect William H. Taft. Hazen specifically reported on the soundness of the Gatun Dam (an integral structure in the canal system), which he said was constructed of the proper materials and not in any danger of failure. Late in his career, Hazen concentrated on ways to statistically describe the recurrence interval of flood flows in rivers. His book on the subject was published the year he died. The Allen Hazen Water Tower was built in 1930–31 in Des Moines, Iowa. Hazen designed the tower shortly before he died. In his honor, the City of Des Moines named the tower after him.

Water purification

Hazen’s early work at the Lawrence Experiment Station established some of the basic parameters for the design of slow sand filters. One of his greatest contributions to filtration technology was the derivation of two terms for describing the size distribution of filter media: effective size and uniformity coefficient. These two parameters are used today to specify the size of filter materials for water purification applications. His first book, ''The Filtration of Public Water Supplies,'' was published in 1895. His first assignment as a sole practitioner in 1897 was the design of the filtration plant at Albany, New York. The plant was the first continuously operated slow sand filter plant in the U.S.”Allen Hazen.” (1930). ''Jour. American Water Works Association.'' 22:9, 1268-70. One of his early assignments was as consultant to

Pittsburgh Pittsburgh ( ) is a city in Allegheny County, Pennsylvania, United States, and its county seat. It is the List of municipalities in Pennsylvania#Municipalities, second-most populous city in Pennsylvania (after Philadelphia) and the List of Un ...

, Pennsylvania, to determine the best method of providing a safe water supply from the Monongahela River. For decades, the city had been wracked with typhoid fever epidemics. At the time, mechanical filtration (or rapid sand filtration) was just beginning to be understood as a treatment process. As a conservative engineer, Hazen recommended that the City install slow sand filters to remove both turbidity and harmful bacteria from its water supply. As early as 1904, Hazen recommended the filtration of the Croton water supply for New York City. As of 2012, a new filtration plant on that water supply is nearing completion.

Sewage collection and disposal

At the age of 24, Hazen was charged with the responsibility for sewage collection and disposal for the 1893 Chicago World’s Fair and Columbian Exposition. For many years, the

Passaic River The Passaic River ( or ) is a river, approximately long, in North Jersey, northern New Jersey. The river in its upper course flows in a highly circuitous route, meandering through the swamp lowlands between the ridge hills of rural and suburb ...

below

Paterson, New Jersey Paterson ( ) is the largest City (New Jersey), city in and the county seat of Passaic County, New Jersey, Passaic County, in the U.S. state of New Jersey.Malcolm Pirnie, Chester M. Everett and L.N. Babbitt), New York City, 1924–1930 In 1897, Allen Hazen opened up a single person practice in New York City and for a couple of years, shared the same address as one of his professional colleagues, George W. Fuller at 220 Broadway. Hazen’s clients included Albany, New York; New York City; Washington, DC; San Francisco, California; Lawrence and Springfield, Massachusetts; Providence, Rhode Island; Pittsburgh and Philadelphia, Pennsylvania; St. Louis, Missouri, Brisbane, Australia; and Ottawa and Toronto, Canada.

Personal life

For many years, Allen Hazen lived in New York City. For most of the last decades of his life, Hazen and his family lived in

Dobbs Ferry, New York Dobbs Ferry is a Administrative divisions of New York#Village, village in Westchester County, New York, United States. The population was 10,875 according to the 2010 United States Census. In 2021, its population rose to an estimated 11,456. The ...

. In 1903, he married Elizabeth McConway in Pittsburgh. They had four daughters and two sons. Their son Richard Hazen (1911-1990) was also a professional engineer in the field of water supply and wastewater engineering, and founded the consulting firm Hazen and Sawyer in 1951.

Professional associations

He was active in numerous professional associations. He was President of the New England Water Works Association and Vice President of the

. In the fall of 1929, Hazen and his wife attended the World Engineering Congress in Tokyo, Japan as a representative of the American Society of Civil Engineers.

Honors

Hazen received honorary degrees of Doctor of Science from both New Hampshire College of Agriculture and Mechanical Arts (1913) and

(1917). In 1915, he received the Norman Medal which is the highest honor given by the American Society of Civil Engineers for a technical paper that "makes a definitive contribution to engineering science." He was selected as an Honorary Member of the American Water Works Association in 1930. In 1971, he was inducted into the AWWA Water Industry Hall of Fame with his friend and colleague, George W. Fuller.AWWA Water Industry Hall of Fame
Accessed 12-06-29.

Limited list of publications

*Sedgwick, William T. and Hazen, Allen. (1892). “Typhoid Fever in Chicago.” ''Engr. News and American Railway Jour.'' April 21. * Hazen, Allen. (1895).
The Filtration of Public Water-Supplies.
' New York:Wiley. *Hazen, Allen, (1896). “The Measurement of the Colors of Natural Waters,” ''American Chemist Jour.'' 18: 364. * Hazen, Allen. (1899). “Report of the Consulting Engineer.” In ''Report of the Filtration Commission of the City of Pittsburgh, Pennsylvania.'' Pittsburgh:n.p., 27-86. * Hazen, Allen. (1905). “Purification of Water for Domestic Use.” ''Trans. ASCE.'' 54:Part D, 131-54. * Williams, Gardner S. and Hazen, Allen. (1905). ''Hydraulic Tables.'' New York:Wiley. * Hazen, Allen. (1906). “Report of Allen Hazen.” In ''Report on the Joint Committee on Sewage Disposal of the City of Paterson.'' Paterson:n.p. * Hazen, Allen. (1916).
Clean Water and How to Get It.
' New York:Wiley. * Hazen, Allen. (1930). ''Flood Flows: A Study of Frequencies and Magnitudes.'' New York:Wiley.

References

External links

Allen Hazen's Photograph Album World Engineering Congress, Tokyo, October-November 1929

* ttp://www.awwa.org/membership/get-involved/awards/award-details/articleid/187/water-industry-hall-of-fame.aspx AWWA Water Industry Hall of Fame {{DEFAULTSORT:Hazen, Allen 1869 births 1930 deaths Dartmouth College alumni American engineers People from Norwich, Vermont