The Waste Management Centre operated by COGERSA in Asturias (Spain) receives up to 900,000 tons of waste per year, out of which 380,000 tons of Municipal Mixed Waste (MMW) are sent to landfills, producing more than 200,000 m3 year-1 of leachate. In addition to landfilling, AD of the OFMSW is also performed. The recovered biogas is used to produce electricity and auxiliary fuel in the surrounding facilities such as the incineration plant (clinical waste) and the treatment of animal by-products not intended for human consumption (ABPs). The leachate produced and OFMSW liquid digestate are treated by a biological nitrification-denitrification system followed by UF membranes. Excess sludge is centrifuged and composted. The commissioning of a new mechanical-biological treatment plant (MBT) by 2024 and the increasing of separate collection of municipal biowaste will allow most organic waste to be diverted from landfilling in the mid-term, thus decreasing landfill biogas and increasing AD biogas.