© Ye Zhu / Greenpeace

A flagship project designed to cut smog in Beijing by providing the city with relatively clean-burning gas is at risk of causing hazerdous air and water pollution, according to a Greenpeace investigation.

The Datang Hexigten Coal-to-gas plant sits in Inner Mongolia to the North-West of Beijing and could provide 25% of its gas needs – helping it cut down on coal use.

But the process of gasifying coal actually increases carbon dioxide emissions and is extremely water intensive.

Chinese firms have built two pilot plants to test the technology and show it can be “zero waste”. Between April and October 2014 we visited one of them seven times

Water samples from an informal pond and an evaporation pool near the plant found high levels of hazardous contaminants that can be associated with the industrial process needed to turn gas to methane.

An aerial photo shows a massive seepage pit used to dispose of the toxic wastewater.

Local herders downwind from the plant wear gas-masks – much like the residents of Beijing.

Communities close to the plant have complained of dizzyness, headaches and insomnia. Incomplete local air quality records suggest the plant exceeded limits of Nitrogen Oxide, Sulpher dioxide and particulates.

There were claims that livestock had also been affected gasping for air and even dying. The plant is still in a testing phase so pollution may increase when it reaches full production.