Discharging, dumping or treating radioactive waste or waste containing infectious disease pathogens or toxic substances into sources of drinking water and nature reserves will be considered crimes of polluting the environment, according to the document.

"Compared with administrative punishment, the judicial document will increase the costs of environmental pollution, which was previously believed to have been too low to curb polluting activities," Ling said.

The outlook on the quality of China's water sources is "far from optimistic," according to a report released by the Ministry of Environmental Protection last month.

The quality of underground water in 57.3 percent of the 4,929 monitoring points in 198 cities around the country is "relatively poor" or "extremely poor". In addition, the resources in about 30 percent of water monitoring points in major rivers was of poor quality, according to the country's surface water standards.

Environmental pollution scares have popped up across China in recent years.

In March, thousands of pig carcasses were discovered in the Huangpu River, which provides 22 percent of Shanghai's tap water. The incident raised significant concerns, despite local authorities' attempts to reassure local residents about the safety of the water.

Liu Changming, a hydro-engineer and academician with the Chinese Academy of Sciences, said Chinese cities are facing an imbalance in water supply and demand, expanding pollution and excessive use of underground water after about three decades of urbanization.

The government should intensify management and control of water, remedy nonpoint source pollution, allocate water supplies in a more scientific and rational way, and selectively develop water supply sources, he said.