This technical note describes how to construct a biogas system. A biogas system is a means of digesting animal manure anaerobically to produce methane gas which is burned to provide heat or light. The system consists of one or more digester tanks, a gas holder, an arrangement of gas pipes, and one or more fixtures to burn the gas. Constructing a biogas system requires the services of a foreman experienced with these systems. Read the entire technical note before beginning the design process.