City Water Supply (main title missing)

City Water Supply (main title missing) Erpi Classroom Films Animals drinking are shown, VO water is essential to all living things. Rain, streams, forests, grasslands & deserts as commentator explains importance of rainfall to vegetation. Map of water sources. MCU Water dipped from spring; drawn from well. Maps of US show large cities using large wells from aquifers; lakes & rivers shown as sources from which other cities draw their water supply. 11:33:34 Very high aerials New York City & its operation of a large system explained: watersheds, lakes & aqueducts shown, & their place in the water system explained w/ maps. Animated diagrams show tunnel carrying water thru a mountain, and of the pressure tunnel that carries the water under the Hudson River. The various watersheds, lakes, and aqueducts serving NYC identified by name. Workers cut thru solid rock during aqueduct construction & remove material. GOOD. Reservoirs. 11:36:37 Sewage treatment plant along Hudson River. Aerial photo of NYC w/ graph showing reduction in typhoid fever after introduction of chlorine & filters. INT laboratory, scientist in white coat examines water sample thru microscope. A measured amount of water placed in a culture medium, incubated, & resulting colonies of bacteria observed. Tests for alkalinity, solids & excessive nitrogen content & turbidity shown. 11:38:59 When water stands in a lake or reservoir suspended matter settles out. Alum is added to settle suspended matter. Lime is added to reduce the acidity caused by the alum. The use of sand filters, the addition of carbon, aeration, & chlorination are also shown as means of safeguarding the water supply. 11:40:10 Map of NYC area. Cross section diagram shows system that distributes water to the consumer - risers & mains. 11:40:47 INT pumping station w/ pumps to maintain water pressure in high buildings; view up large 1920s / 1930s skyscraper. Montage of many uses of water in a city inc. industrial laundry, street cleaning, public bathing, swimming pools; fountains, firefighting, housewife pouring kid a glass of tap water. The End. Health & Safety; Sanitation; 1940s daily city life; Recreation;