The Brogborough test cells were initiated in 1986 to demonstrate several robust and easily applied techniques for accelerating waste degradation in landfill, principally as a means of enhancing energy recovery from landfill gas. This paper maps the project up to July 1998. The main conclusions are listed below. The Brogborough test cells data set includes over 9-years continuous flow data – longer than any other large scale landfill test programme. Specific yield data are 2 to 3 times higher than published data from commercial landfills – even from the control cells – indicating increased recovery as a result of the idealized landfill engineering and gas abstraction systems in place. Cells 5 and 6 (in situ treatments) produced more rapid methanogenesis, as designed. Cells 3 and 4 (applied treatments) have shown statistically significant enhancement in landfill gas production rates relative to the control cell of 20 to 30% in specific yield. Total yields have exceeded 113 m3 t–1.