What's good for China's air may not be good for its water, according to an analysis from environmental experts.

China's State Council's announced a plan last month to combat air pollution, which includes banning new coal-fired power plants in areas around Beijing, Shanghai and Guangzhou. But some recommendations in the measure — now seemingly urgent in light of the record-setting levels of smog that recently shut down the northeastern Chinese city of Harbin — could be harmful to the country's water supplies if carried out, experts at World Resources Institute (WRI) wrote on their website (www.WRI.org).

The Air Pollution Control Action plan calls for replacing coal with natural gases, including the conversion of coal to synthetic natural gas (SNG). But WRI's experts said that it takes six to 10 liters of freshwater to produce one cubic meter of SNG, which would be a drain on China's water supplies.

Many of the 18 approved SNG plants that WRI analyzed are going to be located in "water-stressed regions" and they could "exacerbate water scarcity." The large-scale facilities can produce 75.1 billion cubic meters of natural gas per year, according to WRI, which will consume 500 to 700 million cubic meters of freshwater a year if operating at full capacity.

"That's almost 20 percent of the region's total industrial water use in 2011," analysts at WRI wrote. "The plants would therefore significantly exacerbate stress in areas already experiencing chronic water shortages."

Most of the proposed plants will be located in arid regions such as Xinjiang and Inner Mongolia, WRI wrote, so "in the dry season, those plants may have to reduce production capacity or experience temporary outages due to the lack of resilience in water supply."

Beijing will become the first city to be powered by SNG, and it will use at least 4 billion cubic meters of the fuel, according to WRI, which will take more than 32 billion liters of freshwater to produce, enough water to "meet 1 million Inner Mongolians' domestic needs for an entire year."

SNG production affects water supplies and it also releases "significantly more greenhouse gases than mainstream fossil fuels," according to WRI. It is a better alternative to burning coal that emits more particulates, WRI wrote, but "rapidly deploying SNG projects might, therefore, be a step backward for China's low-carbon energy strategy."

Tien Shiao, senior fellow at WRI and an author of the analysis, told China Daily that it might seem contradictory that SNG plants are being proposed for areas already water-stressed, but the north is where China's coal supplies are, which is needed for the gas conversion. Conversely, much of China's water is in the Yangtze River basin in the south, but the country's coal reserves do not reside there. "It's a Catch-22," Shiao said.

The Chinese government needs to consider whether the benefits of SNG creation outweigh the potential harm to the country's water supplies and impact on climate change, according to WRI, and also needs to consult the country's water experts in energy planning.

China needs to prioritize energy projects that have less environmental risks, WRI added, and "only then will China more successfully manage its conflict between economic growth and resource demands and find lasting energy security."

amyhe@chinadailyusa.com