Feb. 21, 2024
Sustainable Water in China

Wang Hongchen: Sustainable Water in China

source: http://info.water.hc360.com/2010/07/130918205795.shtml


Beijing Gaobeidian Sewage Treatment Plant

Water is the source and foundation of life. Human beings must consume water in order to maintain a body composition that is 60 to 70 percent water (80 percent for children). Society also relies on water as an integral part of all industrial and agricultural production activities without which society would break down.

China currently faces an unprecedented crisis caused by severe pollution of its water resources which are already in short supply.  Finding a solution to this crisis is absolutely necessary if we are to have any hope of achieving truly sustainable development.

Water Pollution - Too Heavy to be Neglected

Water pollution reduces our supply of usable water, which in turn causes water shortages, ultimately leading to a water crisis, according to Professor Wang Hongchen, who is Vice President of the Environmental School of People's University of China.

Wang Hongchen considers the severity of pollution of different categories of water supply: surface water pollution level is still relatively high nationally; the seven main water systems are moderately polluted overall; and the explosion of algae in lakes and water reservoirs (called “eutrophication”) is serious.  Although the overall quality of underground water is relatively good, there has been a deterioration of underground water quality in some areas.  On the other hand, pollution of coastal waters is generally light.

Across China, there are 409 water quality monitoring sections that rate two hundred rivers across China on a graded scale of I to V, with I indicating the best water quality and V being the worst.  55% of China’s water stations are grades I-III; 24.2% are n Grade IV – V; and 20.8% are actually evaluated to be worse than Grade V.  More specifically, Zhujiang River and Changjiang River remain in generally good quality; the Songhua River is lightly polluted; the Yellow River, Huaihe River and Liao River have medium levels of pollution; and the Haihe River has a serious level of pollution.

Among 28 major lakes that are controlled by the state, 21.4% are Grade IV, 17.9% are Grade V, and 39.3% are worse than Grade V.  Taihu Lake, Dianchi Lake and Chaohu are worse than Grade V, with medium levels of entrophication (algae spread).

As for coastal waters, areas with grades of I to IV covered about 37,665 km2 in area.  While the waters of the Bohai Sea are lightly polluted, Liaodong Bay and Jiaozhou Bay have poor water quality, with Grade I and Grade II water accounting for less than 60% of their total volume. The Donghai coastal area has medium pollution, with Hangzhou Bay having the worst quality of water, 100% of which is Grade IV.

Regarding ground water, there has been considerable pollution of shallow waters in some plains regions, with  with Binhai suffering the worst water quality.  About 70 million people in China still drink groundwater that does not meet drinking water standards.

Bleak Outlook Regarding Water Shortages

Water pollution is only one side of the coin; the other side is water shortage. China has to feed 20% of the world’s population, notes Wang Hongchen, but it only has 6% of the world’s water supplies.  On average, Chinese people have 28% less water available to them than people than the world average, and the amount of water available for cultivating land in China is 30% less than the world average.

The overall shortage of water in China is aggravated by an unbalanced regional and seasonal distribution of water resources with respect to population and agricultural land. For example, the north of China is home to 45% of the nation’s population and contains 65% of its cultivated land, but it only has 19% of its water resources. Moreover, about 60%~80% rainfall comes mainly in the three or four months of the annual flood season.  This uneven spatial and temporal distribution water resources makes it even harder to develop and use water resources, which are in effect reduced to only 30% of their availability.

Wang Hongchen says China has already become the world's leading consumer of water, but because of agricultural efficiency is low, industrial water usage is immense, the population is enormous, China’s water resources are near exhaustion.  It is estimated that the total amount of utilizable water in China is 800 billion cubic tons of which 600 billion are already being used. Water consumption is expected to continue growing and is predicted to reach its saturation point when the population reaches 1.6 billion.

As Wang Hongchen has pointed emphasized, a shortage of water combined with water pollution will cause a serious water crisis.  Such a crisis will not only threaten our food security and continued economic development, but it will also hasten the collapse of our natural environment.  As the amount of water we use approaches the total amount available, water will disappear from the environment:  Rivers will stop flowing, lakes will shrink, land surfaces will sink (geological subsidence), and sea water will rush in…

Key Solution is Cyclical Utilization

Wang Hongchen believes that while there are many reasons for China’s water problem, two basic reasons are too little water and too much usage. Since China is a large country with a huge industry and a vast population, water consumption is already very high and will continue to increase due to further development and population increase. Finding solutions to the water problem is not only aimed at protecting the environment but also promoting development.

But the question remains: How can we solve China’s water problem?  Many approaches have been suggested, but Wang Hongchen explains their shortcomings as follows.  We cannot dig new springs because China lacks new resources. We cannot regulate usage, because China has no more room for additional regulation: industrial water usage today is already reduced to one third of what it was ten years ago; the reduction of 100 billion cubic tons of water used in agriculture requires investing 100 billion euros; domestic water usage can hardly be cut any further; and ecological water usage has virtually disappeared. Seawater desalination is not an option simply because it is too expensive at 8 yuan per cubic meter, not to mention transporting and distributing the desalinated water. Indeed, as the old saying goes, distant water cannot quench present thirst.

The essential solution to China's water problem lies in one word, according to Wang Hongchen: recycling.  And the crucial component of water recycling is sewage treatment.

Wang Hongchen says the total volume of water resources in China is 2.7 trillion cubic tons.  Current sewage volume is 57 billion cubic tons and is expected to increase to 80 billion cubic tons by 2025, representing water consumption that is 10% of the total 800 billion cubic tons of available water.  In other words, if we cannot properly treat these 80 billion cubic tons of sewage water, all 2.7 trillion cubic tons of our water supplies will get polluted, so we cannot guarantee the availability of the 800 billion cubic tons of usable water.  Thus, to succeed in recycling 80 billion cubic meters of sewage is to achieve the sustainable development of water resources, and provide a fundamental strategy for solving China's water problem.

Drainage Systems Must Be Modernized

A former chief engineer of the Beijing Drainage Group and a former general manager of Beijing Capital Drainage Services Company, Wang Hongchen has a wealth of experience dealing with drainage treatment. She believes that in order to realize the recyclying of 80 billion cubic tons of sewage, traditional drainage systems must be replaced by modern ones.  Traditional drainage systems collect and process sewage to a certain national standard before discharging it.  However, modern systems not only implement the entire collection, processing and recycling process, but also play a significant role in water resources allocation and actually become a component of the hydrologic cycle.

According to Wang Hongchen, by the end of 2009, China had built 70,000 km of drainage lines as well as 1998 sewage treatment plants with a total handling capacity of 110 million cubic tons a day. Currently, we are building an addtional 95,000 kilometers of drainage lines and 1977 new sewage treatment plants which will be able to deal with another 55.22 million cubic tons of sewage a day.  By the end of the 11th Five-Year Plan, China’s sewage treatment capacity of 160 billion cubic tons per day is expected to be the greatest in the world.  By that time, the sewage treatment rate will exceed 85%, and traditional drainage systems will no longer be constructed, providing the basis upon which China modify and upgrade to a modern drainage system.

Modern drainage systems will not merely control water pollution, but will also have the function of storm sewage collection, sewage treatment, recycling and sludge disposal. Their purpose, first of all, is to meet public services requirements, including drainage service, public health, drainage of stagnant water, water pollution control, recycling, etc.  Second, they should facilitate the normal water circulation process and merge the human cycles of water usage with natural water cycles.  Third, it should facilitate the normal ecological cycle of natural elements such as carbon, nitrogen, phosphorus, sulphur and so forth.

While building the modern drainage systems, Wang Hongchen believes we need to implement hundred-percent storm sewage collection, advanced sewage treatment, sludge disposal, and proper resource utilization.  In particular, she
emphasizes sludge disposal – an easily ignored problem that creates not only environmental problems but also health problems. She says China produces 30 million tons of sludge every year but has just begun to deal with its treatment.  Sludge disposal must include reduction, stabilization, and detoxification with the ultimate goal of returning the treated sludge to the earth.

At present, Beijing, Kunming and some other cities have already begun constructing a modern drainage system.  Beijing has already invested 8 billion yuan to modernize the system so that water discharged from treatment plants at the end of the treatment process will meet Grade IV groundwater standards.  The money will also be used to reconstruct storm sewage collection systems, establish water circulation systems, and implement sludge disposal and resource utilization.  Through this investment, Beijing has begun the process of modernizing its draining and sewage treatment systems.

Translator: Feng Yan

Proofreader: Vincent, Bruno-Ken