The Envac Automated Waste Collection System is a proprietary waste management system that uses large, underground pneumatic tubes to distribute waste to a centralized processing facility.[1] The system originated in Sweden in the 1960s, and is designed by the Swedish corporation Envac.[2]
The process begins with the deposit of trash into intake hatches, called portholes, which may be specialized for waste, recycling, or compost. Portholes are located in public areas and on private property where the owner has opted in. The waste is then pulled through an underground pipeline by air pressure difference created by large industrial fans, in response to porthole sensors that indicate when the trash needs to be emptied and help ensure that only one kind of waste material is travelling through the pipe at a time. The pipelines converge on a central processing facility that uses automated software to direct the waste to the proper container, from there to be trucked to its final location, such as a landfill or composting plant. The facility retains only a small maintenance staff, and is otherwise managed remotely by Envac from its headquarters in Stockholm.[1]
Envac systems are in use in thirty countries around the world, and in many major cities, such as Barcelona, London, and Stockholm.[1][2] Montreal is set to implement an Envac system in 2012, at a cost of $8.2 million, to service its downtown arts district.[1]