While some thirsty coastal cities in China are turning to long-distance water diversion systems for relief, treated sea water is highly recommended as an alternative solution, if not a better one.
"Three decades worth of effort has ranked China among the world's few countries capable of sea-water desalination," said Hui Shaotang, director of the Institute of Sea Water Desalination and Comprehensive Utilization in North China's Tianjin Municipality.
Hui made the remark yesterday in response to a report released on Saturday by the Tianjin Municipal Environmental Protection Bureau. The report indicates that Yellow River water recently introduced to the city is suitable for drinking.
Calling the successful introduction of the Yellow River water a good stop-gap measure for the people of Tianjin, Hui said nonetheless it is better to develop a more sustainable resource - the sea water - in the long term.
A more stable resource is necessary because the Ministry of Water Resources forecasts that China will use up to 800 billion cubic meters of fresh water by 2030, Hui said.
To tackle a serious water shortage caused by a six-year dry spell, Tianjin, the largest coastal city in North China, started earlier this month to channel a total (by next February) of 350-million cubic meters of Yellow River water to Tianjin from the Weishan Sluice Gate, 440 kilometers away.
In light of the staggering amount of water required, Hui said coastal cities need to bear in mind that "water diversion can only alter the geological layout of water resources. It's not able to enhance the total amount available."
According to Hui, about half of China's urban water consumption goes to industrial equipment cooling, while about 30 percent of urban people's water consumption is for toilet flushing.
"With specially constructed pipelines, our treated sea water can do things as well as tap water," he said.
Because of improved technology and production efficiency, the production cost of one ton of fresh water produced from sea water has been greatly reduced from 7 yuan (85 US cents) to the present 5 yuan (60 US cents), which makes it more marketable than ever.
Sales figures for desalinated water illustrate the case. Since it was first marketed in Tianjin in October, the new type of water, which sells for 1 yuan (12 US cents) per bottle, has obtained a strong foothold in local supermarkets.
"In the initial stage of our industrialization of the new type of water in 1994, our production costs of 10 yuan (US$1.20) per ton gave us no advantage at all in comparison with that of average purified water, which cost less than 1 yuan (12 US cents)," said Du Chunyuan, one leading developer of the drinkable sea water.
(China Daily November 18, 2002)
