Upon Slovenia's accession to the European Union (EU) in 2004, the country's focus on municipal solid waste management (MSWM) policy underwent a significant shift. It centered on implementing nationwide separate waste collection systems, incorporating mechanical biological treatment (MBT) plants, and planning for two large-scale incineration facilities, which faced delays due to local objections. The national government introduced regulatory changes governing the types of waste that could be landfilled, leading to the closure of roughly half of all landfill sites across the nation.