Word: planted
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Dates: during 1960-1969
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Telltale Tap Water. The trouble is that such conventional methods of treatment and purification as filtration, dilution and chlorination are unable to cope with some of today's contaminants. Household detergents pass through modern treatment plants with only partial removal. Certain synthetic chemicals, reports the U.S. Public Health Service, can travel hundreds of miles, go through a treatment plant, and still show up in tap water...
...searching for the answer to a question that has plagued farmers throughout history: How much water does each crop actually need? Using radioactive tracer materials, American-born Soil Physicist Daniel Hillel is keeping track of irrigation water as it enters the fields and as it escapes through evaporation or plant transpiration. He radiates neutrons into the soil near plant roots and measures the results: the more water in the soil, the slower the neutrons move. He shoots leaves with beta rays to determine their water content. Going back to the same leaves daily, he keeps a record of their transpiration...
...could drink melted water from the ice of salty seas. In freezing, he learned, the ice crystals form separately from the brine, then melt down as fresh water. One important advantage of this kind of desalinization is that it takes less power to freeze than to heat. A prototype plant, developed by Zarchin and built by Colt Industries Inc. of the U.S., is now in operation at the Red Sea port of Elath...
Similar systems can be adapted to almost any fuel-electricity, natural gas, or nuclear energy. In teeming Hong Kong, a desalinization plant is powered by burning garbage. It is the more immediate problem of cost that causes the most concern. By improving technology and experimenting with large-scale operation, engineers have already lowered the average cost of desalinization from about $5 per 1,000 gallons of water in 1952 to about $1. But the goal is still far off-less than 35?, which would make desalinized water competitive in price with natural water...
When that distant goal is reached, another difficulty will arise: mountains of coarse, unusable salt will somehow have to be disposed of. Every quart of sea water contains an average of 1¼ oz. of salt; a 150-million-gallon-capacity plant would end up producing more than 23,000 tons of salt a day. "Only when you have effective water management and still have a shortage," says Jack Hunter, an assistant director of the Interior Department's Office of Saline Water, "then desalinization may be the answer...