Wujia, a village in north China's Inner Mongolia Autonomous Region, is unusual for its picturesque environment. Dung hills which are common in most of rural China are not seen here. The air also smells fresh, not like cattle and pigs.
Yang Jianguo, a farmer in the village, gives the credit to the village's 571 methane pits. With the government subsidy of 1,200 yuan (US$145) for building one pit, nearly all the households in the village have build their own.
Though having 580 households engaging in breeding of 5,300 head of livestock in the village, the village does not worry about the treatment of human and animal wastes. One methane pit can treat 30 cubic meters of wastes each year, said Yang.
Besides, with the help of technical personnel, farmers here also renovated their livestock pens and linked toilets to the pits, making the waste easy to flow into the pits for methane generation.
In the meantime, the gas generated in the pits is piped out for cooking, heating and even for lighting.
According to Yang's calculation, a methane pit can generate 370 to 440 cubic meters of gas, sufficient for cooking and lighting for a households of four members for a whole year. And the residue in a pit after generating gas could be used as fertilizer for some1.3 hectares of farm land a year.
"Now we don't have to suffer from the smoke in kitchen any more," said Yang. In the past, Yang and others in the village relied on burning firewood or dried grass for cooking.
The smoke from burning firewood in rural kitchens and discharge of human and animal wastes are two major sanitary problems faced by rural residents.
Both the World Health Organization and the United Nations Development Program noted that thick acrid smoke from rural stoves and fires inside farmer homes is associated with around 1.6 million deaths per year in developing countries.
In addition, approximately 70 percent of Chinese people live either on farms or in villages. No formal waste management systems are in place for these people. There are 200 million simple toilets in rural areas in China, which are no more than a pit underneath or a trough running to a storage pit behind the buildings, posing a severe sanitary problem.
For the local government, the benefits of methane use also lies in the possibility of putting the protection of ecological environment into real effect as farmers do not cut trees for firewood.
"With the methane pits, natural forestry an be protected really and truly," said Suo Shengqian, engineer with the Datong Forestry Bureau in northwest China's Qinghai Province.
According to Suo's calculation, with one pit, a household could save 1.5 tons of firewood, which equals to 0.3 hectares of forest being protected.
Since the 1970s, China has been promoting the use of underground, individual household scale, methane pits to process rural organic wastes. So far, in Inner Mongolia Autonomous Region alone, there are 20,000 rural households enjoying the benefits of the methane.
According to an ambitious plan set by the Ministry of Agriculture, there will be approximately 20 million pits by the end of 2004 in the whole country, and the figure will increase to 50 million by 2010.
(Xinhua News Agency October 21, 2004)
