By Zhan Yan, China Features

    BEIJING, Dec. 2 (Xinhua) -- The water in Zhao Bo's village on the outskirts of Beijing was a sickly shade of green. After drinking from the local well, Zhao and his fellow villagers could not go a month without suffering from diarrhea. The contamination was believed to originate from a zinc-plating plant established near the upper reaches of the well ten years ago.

    Plant officials compensated for the worsening water quality by drilling a second well, according to Zhao, a 50-year-old farmer from Daciluo Village. But the water in that well became contaminated too. To access cleaner drinking water, residents decided to drill yet another well further upstream, while wealthier members of the community vowed to drink only bottled water. But the problem still did not go away.

    "The new well could provide only enough water for drinking. We still have to use the original well to water our crops and feed our pigs, chicken, and ducks," Zhao says. He explains that the state-supplied tap water was cut off in the village three years ago after water prices went up and residents were no longer able to pay the bills.

    No administrative action was taken against the polluting factory until September, when the government closed down the zinc-plating plant after a local newspaper exposed the case. Daciluo Village was one of the lucky ones. While water contamination is not rare in China, few polluting enterprises are ultimately punished, according to Dr. Wen Dongguang with the China Geological Survey (CGS).

    "Those enterprises are pillars of the local economy. Local governments are reluctant to take action against them for fear of affecting their revenues and social stability if the companies lay off their workers," Wen said.

    Such misgivings have resulted in loopholes in the implementation of pollution prevention and control laws, and groundwater pollution has become ever more serious with China's economic growth.

    Groundwater is now contaminated in about 90 percent of the nation's cities, says Zhang Lijun, deputy director of the State Environmental Protection Administration. An increasing number of water samples have been found to contain toxic substances.

    Groundwater constitutes a third of China's freshwater resources and plays a key role in the nation's water supply. About 70 percent of drinking water and 40 percent of agricultural irrigation water come from groundwater.

    Pollution is the biggest challenge to China's groundwater management. Yet the most recent national survey, completed by the Ministry of Land and Resources in 2004, downplays the alarm. It concludes that China's shallow aquifer (rocky areas containing water that can be used to supply wells) is "relatively good," with about 92 percent of the water supply fit for daily use and 63 percent suitable for drinking.

    "It seems rosy because the survey only tests the inorganic matters in groundwater, but now more organic substances are culprits in groundwater pollution and it costs more to test organic matters," Wen says.

    Due to the uneven distribution of groundwater -- 67.7 percent in the south and 32.3 percent in the north -- China's arid northern areas and relatively developed eastern areas suffer the most pollution, while poverty-stricken areas in the northwest are plagued by extreme water shortages. "China's groundwater management is about 10 to 20 years behind the world's most advanced levels," says Yin Yueping, an expert with the CGS.

    Yin notes that many areas have reported ground subsidence or clefts due to groundwater overuse. "It's easier for pollutants to seep into the groundwater in areas that have experienced unsustainable exploitation, due to underground pressure changes," he observes. About 50 cities in China have reported sinking ground. Shanghai, Tianjin, and Taiyuan report the worst subsidence, each having dropped by more than two meters since the early 1900s, according to the Ministry of Land and Resources survey.

    In coastal areas, unbridled exploitation of groundwater has resulted in the infiltration of water supplies by seawater. This has occurred in Liaoning, Hebei, Shandong, and Hainan provinces and in the Guangxi Zhuang Autonomous Region, leaving wells dry and residents with little access to clean water. In the eastern Bohai Gulf, seawater invades 62 square kilometers of groundwater annually. In 2003, the infiltration topped 2,457 square kilometers, leaving 400,000 people without access to clean water and destroying 300 million kilograms of grain, according to the survey.