Civil Engineering Reference
In-Depth Information
400
Stoppage of Pumps Feeding Illinois and Michigan Canal
and Probably Combination of Other Circumstances
Chicago
Fire
300
First 2
mile
Intake
Low Lake
Level
200
Drainage Canal Opened
1905-08 Intercepting Sewers Built
Pasteurization of Milk Started
Chlorination of Water Started
100
0
1860 1870 1880 1890 1900 1910 1920 1930 1940 1950
Fig. 1-1.
Typhoid fever mortality in Chicago (1860-1950) (
Source:
References 3, 5)
lished an experiment station in Lawrence, Massachusetts, in 1887. While the Lawrence
experiments were going on, the city was hit with a typhoid epidemic and a sand filter
was installed in Lawrence. In 1893, Massachusetts Institute of Technology professor
W. T. Sedgwick examined typhoid cases before and after the sand filter was installed
and reported that the death rate from typhoid fever dropped 79 percent following the
installation of the filter. Other filtration experiments were conducted at Louisville,
Kentucky, in 1895 to 1897. By 1900, there were more than 3000 municipal water
systems in the United States supplying water to customers. Philadelphia was one of
the first large U.S. cities to adopt sand filtration in 1906, and by 1907 over 30 cities
nationwide were doing so.
While filtration was found to be somewhat effective in
removing
disease-causing
microbes (pathogens), dramatic improvements in the safety of water occurred due to
the use of chlorine to disinfect or
kill
the pathogens. The first permanent chlorination
plant was built in 1902 at Middelkerke, Belgium. Over the next few years, chlorination
became standard practice in Great Britain. The first major city in the United States to
chlorinate its water supply was Jersey City, New Jersey, in late 1908.
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The dramatic
effect of chlorination was a marked decrease of typhoid and other waterborne diseases.
Early pioneers in water treatment included Abel Wolman, who in 1919 demonstrated
that chlorine consumption varied widely from water to water and helped develop the
concept of chlorine demand.
By the 1920s, use of sand filtration and chlorine disinfection in the United States
defined ''state-of-the-art'' treatment and virtually eliminated major waterborne-disease
outbreaks, such as typhoid and cholera. An example of how effective water treatment
had become in reducing sickness is found in Wheeling, West Virginia. In 1917-18,
the rate of typhoid fever was 150-200 cases per 100,000 population. Chlorination was
added in 1918, and the rate of illness dropped to 25 per 100,000 population.
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