The poor quality of natural water resources and devastating pollution threaten the safety of drinking water for millions of inhabitants across vast areas of rural China, a report warned on Wednesday.

A woman from an unnamed village in Chongqing washes clothes on July 29 in a pool that has been taken over by duckweed. [China Daily]

The report, released by the Ministry of Water Resources and the World Wide Fund for Nature (WWF), addresses the need to supervise the safety of water resources in rural China.

Most of China's water resources in rural areas naturally contain excessive levels of heavy metals, such as arsenic, fluoride and iron, as well as some radioactive elements, according to the report. 

Rural water pollution, the result of rising incidents of industrial pollution, outdated sewage systems, and the overuse of pesticides and chemical fertilizers, also endangers the health of rural inhabitants in China, it said.

Industrial pollution is responsible for depositing heavy metals and nitrates in rural water supplies, contributing to eutrophication, a process in which excessive nutrients stimulate abundant plant growth that depletes the oxygen supply for other aquatic life.

"It is a challenge for us to be able to guarantee the safety of rural drinking water, especially when industrial pollution is moving from cities to the countryside and we lack a comprehensive rural sewage treatment system," said Ni Wenjin, deputy director of the department of rural water resources under the ministry and a co-author of the report.