HOHHOT: Wujia, a village in North China's Inner Mongolia Autonomous Region, is unusual for its picturesque environment. Dunghills, common in most of rural China, are not seen here. The air is fresh, and no odor of cattle and pigs is prevalent.

Yang Jianguo, a farmer, gives the credit to the village's 571 methane pits. With a government subsidy of 1,200 yuan for building a pit, nearly all the households in the village have built their own.

Though 580 households engage in raising and breeding of 5,300 head of livestock, the village does not worry about the treatment of human and animal waste. One methane pit can treat 30 cubic metres of waste annually, Yang said.

With the help of technical personnel, farmers have also renovated their livestock pens and linked toilets to the pits, making waste flow easily into the pits for methane generation.

In the meantime, 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 metres of gas, sufficient for cooking and lighting for a household of four for a year. And the residue in a pit after generating gas can be an effective fertilizer for some 1.3 hectares of farmland.

"Now we don't have to suffer from the smoke in our kitchens anymore," said Yang. In the past, Yang and others in the village relied on firewood or dried grass for cooking.

The smoke from burning firewood in rural kitchens and the discharge of human and animal wastes were two major sanitary problems faced by residents.

Both the World Health Organization and the United Nations Development Programme noted that thick acrid smoke from rural stoves and fires inside homes is associated with around 1.6 million deaths per year in developing countries.

In addition, approximately 70 per cent 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 dug-out pit or a trough running to a storage pit behind buildings, posing severe sanitary problems.

For the local government, the benefits of methane use also lies in the possibility of protecting the environment into real effect, since farmers no longer have to cut trees for firewood.

"With the methane pits, natural forestry can be protected really and truly," said Suo Shengqian, an engineer with the Datong Forestry Bureau in Northwest China's Qinghai Province.

According to Suo's calculations, with one pit, a household saves 1.5 tons of firewood annually, equal to protecting 0.3 hectares of forest.

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.

(China Daily 10/22/2004 page3)