John Phillips (surveyor) - Separation of Effluent From Storm Waters

Separation of Effluent From Storm Waters

Combined- Versus Separate-Sewer Systems Although sanitary wastes were a constant input to European sewer systems, designs did not anticipate this component until 1843 in Hamburg. The first types of wastewater legally allowed into the storm sewers were dishwater and other kitchen wastes. When the water closet came into general use in the mid-19th century, existing privy vaults and cesspools became overwhelmed. Eventually, this led to the permitted discharge of sanitary wastes into sewers previously restricted to surface runoff only, legally creating combined wastewater. The permitted discharge of sanitary wastes did not occur in London until 1847 (Kirby and Laurson 1932) or in Paris until 1880 (Reid 1991).

Phillips proposed the separate system of sewerage for London in 1849. But a few years later, Bazalgette’s combined system was selected (Metcalf and Eddy 1928). Although supporters for separate sewerage existed, early systems were mostly combined because: (1) there was no European precedent for successful separate systems; (2) there was a belief that combined systems were cheaper to build than a complete separate system; and (3) engineers were not convinced that agricultural use of separate-sanitary wastewater was viable (Tarr 1979).