The production of biogas, which is regarded in many countries as a by-product of an efficient system of energy production, has become in China a comprehensive, controlled method of waste disposal, recycling resources, supplying energy and fertilizer and improving rural health, as the digesting of wastes in a closed container kills many of the pathogens responsible for common human diseases.There are already approximately seven million biogas pits in operation, with Sichuan (Szechuan) province leading the country in a movement to extend the practice throughout the countryside. This manual describes in detail how to build the pit, and covers a full range of designs to suit various soils from sandstone to sheer rock. It also includes a description of how the original manual was used.Uses diagrams and pictures to show how the basic design of the biogas pit can be adapted for construction in different soils, from sandstone to sheer rock, which should encourage other developing countries to embark on their own biogas programmes.