The composting process used by the GMWC combines bottom aeration and a cover system. The key to the composting process is the mix ratio of biosolids and wood waste consisting primarily of bark and ground forestry waste. The bulking material provides a source of carbon but is essential in obtaining a porosity that facilitates the migration of air for a thorough and complete aerobic process.
The current system has a capacity to process 15,000 tonnes of biosolids mixed with 15,000 tonnes of wood waste for a total of 30,000 tonnes per year of material to compost.
Compost curing and finishing take place on adjacent asphalt pads. The design concept is based on total containment of surface runoff from rainfall and snowmelt together with leachate generated from the composting process.
The system produces Type “AA” compost in accordance with the BNQ (Bureau de normalisation du Québec) CAN/BNQ 0413-200/2016 standard.