Some local governments are still putting more emphasis on economic growth than on the environment and people's health, Zhang said. He urged officials from local environmental protection bureaus to stick to their responsibilities and not approve projects that pollute.

"I've learned that in some areas, local governments are trying to shrink the protection zone for drinking water sources, to make room for more development projects, regardless of their impact on the environment," Zhang said.

Protection zones have been designated for each drinking water source, where industrial projects are forbidden in order to ensure no sewage is discharged into the water source, according to the regulations formulated by the Ministry of Environmental Protection.

"The ministry and local protection bureaus should never approve a request for re-designing the protection zone for such purposes," he said.

Zhang also told local environment authorities to be wary of industrial projects that involve heavy metals, such as lead, mercury, cadmium, chromium and arsenic.

The ministry is revising a plan for heavy-metal pollution. The State Council will release the plan soon, Zhang said.

The protection of drinking water is also hampered by insufficient water quality monitoring equipment. Most of the country's environment monitoring stations still do not have the facilities to carry out examinations for all the 109 water pollution indicators.