BEIJING — April 11, 2016 — More than 80 percent of water sourced from shallow underground wells in China is polluted by runoff from farming and industry and is unsafe for drinking, a Chinese government study revealed.

A report released by the water ministry last week showed that most of the samples taken from over 2,000 shallow wells in the north and east in 2015 were of poor quality. More than 30 percent were classed as Grade IV, which is suitable only for industrial and agricultural use, and almost 50 percent were Grade V, which is water unfit for human consumption of any kind.

Contaminants in the water included manganese, fluoride and triazoles — chemicals used to make fungicides. Some areas also had pollution caused by heavy metals, the New York Times reported.

Manganese: The good for you, bad for you mineral

These shallow wells are used by farms, factories and rural households.

The water ministry noted that the findings only relate to shallow wells in the rural northeast, a region that was targeted for testing because it was known to have water quality problems.

Officials also stressed that drinking water for urban areas across the country comes from deep underground aquifers, 85 percent of which meet national water quality standards.

All 33 sources that supply drinking water to cities with a population larger than 500,000 meet water quality standards, water ministry official Chen Mingzhong told Chinese newspaper the People’s Daily.

China has pledged to cut industrial pollution and improve water quality as part of its latest five-year plan.