The value of pure water / by George C. Whipple.

  • George C. Whipple
Date:
1907
Catalogue details

Licence: Public Domain Mark

Credit: The value of pure water / by George C. Whipple. Source: Wellcome Collection.

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    improves its general attractiveness. By using a prop¬ erly designed filter-plant, supplemented if necessary by sedimentation or aeration or chemical treatment according to local needs, an infected water may be made safe to drink, a turbid water may be clarified, a colored water rendered colorless, a bad-smelling water made savory, and a hard water made soft. By the applica¬ tion of the formulae above described the beneficial effects of filtration may be clearly demonstrated. Sanitary quality.—The following figures show to what extent the sanitary value of a polluted public water-supply is increased by an efficient system of filtration: Lawrence, Mass.: Water-supply, Merrimack River, filtered by a slow sand-filter. Population, 70,000. Water consumption, 40 gallons per capita daily. Before filtration the typhoid-fever death-rate was 121 per 100,000; since then it has been 26. Before filtration D = 2.75(121 — 20)X~np=$693. After filtration D=2.75(26-20)xW“*41. Increase in sanitary value =$693— $41 =$652 per million gal¬ lons, or $665,000 per year, or $9.50 per year per capita. Albany, N. Y.: Water-supply, Hudson River, filtered by sand-filter. Population, 95,000. Water consumption, 165 gallons per capita daily. Before filtration the typhoid-fever death-rate was 104 per 100,000; since then it has been 26. Before filtration Z) = 2.75(104— 20) X iff =$140.
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