Sewer History: Articles

Design Choices - Combined and Separate Systems

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As America's cities began to grow and their population densities increased, two potential design approaches were possible: cities with storm sewers could combine storm water and sewage -- the "combined" system, or they had to create "separate" systems for dealing with sanitary sewage. Most likely, the combined system was the choice for cities with heavy precipitation (rain and snow) and relatively flat terrain, where storm water was needed to flush the sewers. Cities with rolling or steep terrain (i.e., good storm water runoff and/or spare precipitation) generally chose the separate system.

The principle of creating separate systems for receiving and conveying human wastes was developed as early as 1842 in England by Edwin Chadwick (considered by many to be the "Father of Sanitation" in England). Other English engineers, such as Sir Robert Rawlinson, carried the same philosophy forward in later years. American engineers, in particular Colonel George Waring, Jr., studied the British systems closely.

See Tracking Down the Roots of Our Sanitary Sewers for more information.

Edward S. Philbrick, American Sanitary Engineering (New York: The Sanitary Engineer, 1881), pp. 1-15, 53-89, 117-123.

Lecture IV: "The Drainage of Towns" (pp. 53-66)
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For other chapters, see Design - before 1900.

Frederick S. Odell, "The Sewerage of Memphis with Discussions," Transactions of the American Society of Civil Engineers, Volume IX (February 1881), pp. 23-52 and Plate IV.

See pp. 24-26 for discussion of Colonel Waring's influence on the creation of a separate system in Memphis.

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George E. Waring, Jr., "Sanitary Drainage," The North American Review, Vol. 137, Issue 320 (July 1883), pp. 57-67. Courtesy of The Making of America Digital Collection, Cornell University Library.

See pp. 58-59.

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Samuel M. Gray, Proposed Plan for a Sewerage System, and for the Disposal of the Sewage of the City of Providence (Providence: Providence Press Company, Printers to the City, 1884), Appendix A, pp. 3-116 and Plates I - XVI and XXIII.

See pp. 64-70 for discussion of the separate system.

Table of Contents
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"The Separate Sewer System," The Manufacturer and Builder, Volume 21, Issue 9 (Sept. 1889), p. 210. Courtesy of The Making of America Digital Collection, Cornell University Library.

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Cady Staley and Geo. S. Pierson, The Separate System of Sewerage, Its Theory and Construction, Third Edition (New York: D. Van Nostrand, Co., 1899), pp. 17-45, 200-239.

Chapter I: "Introduction" (pp. 17-38)
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Chapter II: "Water Carriage Systems" (pp. 39-45)
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Chapter X: "Flushing and Ventilation" (pp. 200-239)
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For other chapters, see Design before 1900.

Colonel E. C. S. Moore, "Introduction, Chapter I, Chapter II, Chapter III," Sanitary Engineering, Volume I, 3rd Edition revised by E. J. Silcock (Philadelphia: J. B. Lippincott Company, 1909), pp. 1-69.

See pp. 21-23.

Chapter II: "Sewerage" (pp. 16-51)
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For other chapters, see Design - 1900 and later.

J. T. Brown, W. H. Maxwell, editors, "Sewerage," The Encyclopaedia of Municipal and Sanitary Engineering (New York: D. Van Nostrand Company, 1910), pp. 421-433.

See pp. 421-423.

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Leonard Metcalf and Harrison P. Eddy, "Introduction: The Lessons Taught by Early Sewerage Works," American Sewerage Practice, First Edition (New York: McGraw-Hill, 1914), pp. 1-31.

Discusses early design in England and the United States, including information on separate and combined systems.

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A. Prescott Folwell, Sewerage - The Designing, Construction, and Maintenance of Sewerage Systems, 7th edition (New York: John Wiley and Sons, 1916), pp. 1-12, 44-68, 69-86, 141-176, 345-358.

See pp. 9-12, 74.

"Sewerage - the System" (pp. 1-12)
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"Flushing and Ventilation" (pp. 69-86)
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For other chapters, see Design - 1900 and later.

H. K. Barrows, "Present Tendencies in Sewer Construction and Design," Municipal Engineering, Volume LIV, No. 4 (April 1918), pp. 144-146.

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Steven J. Burian, Stephan J. Nix, Robert E. Pitt, S. Rocky Durrans, "Urban Wastewater Management in the United States: Past, Present, and Future," Journal of Urban Technology, Volume 7, Number 3 (December 2000), pp. 33-62. Used with permission.

See pp. 43-51 for discussion of combined versus separate systems in the United States.

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