Landfills in developing countries, like Indonesia are dominated by organic solid waste, with water content reaching 80%. It is impossible to manage them by incineration processes. Naturally, all organic material can decompose and produce methane gas, carbon, water, as well as leave blackish fine soil-like material, called compost. Therefore, the recovery of the landfills can be done by using landfill mining methods. However, the benefits, costs, and environmental impacts of landfill mining are highly dependent on landfills age, material characteristics, disposal systems, economic and social development of the community, and climate. The main objective of this study was to analyze the optimum age of garbage heaps to obtain the right time on the recovery of the landfills. Five excavation points were prepared at 4–5, 6–7, 8–9, 10–11, and > 12 years. Each excavated material was dried, separated, and grouped according to each component, and then weighed, tabulated, and shown as a percentage of excavated garbage composition. The result shows that landfill mining can be carried out at a garbage heap aged 8–9 years in which compost landfill mining has obtained at 50%. Other discussions concern the existence of organic and nonorganic components as well as the usage of plastic bags and nappies indicating the lifestyle changes of the people.