Archinode studio makes a very interesting suggestion concerning the use of 3D printers and industrial-scale recycling:

New York City is disposing of 38,000 tons of waste per day. Most of this discarded material ended up in Fresh Kills landfill before it closed. The Rapid Re(f)use project supposes an extended New York reconstituted from its own landfill material. Our concept remakes the city by utilizing the trash at Fresh Kills. With our method, we can remake seven entirely new Manhattan islands at full scale. Automated robot 3d printers are modified to process trash and complete this task within decades. These robots are based on existing techniques commonly found in industrial waste compaction devices. Instead of machines that crush objects into cubes, these devices have jaws that make simple shape grammars for assembly. Different materials serve specified purposes; plastic for fenestration, organic compounds for temporary scaffolds, metals for primary structures, and etc. Eventually, the future city makes no distinction between waste and supply.

Thanks to Brainsturbator for bringing this article to our attention.