The capacity of the Għallis landfill is being increased by the equivalent of 130 Olympic-sized swimming pools, without taking up any more land.
The project will see the Naxxar landfill enlarged by 330,000m3 by building a retaining wall made out of waste at a 70-degree angle rather than the 30-degree slope generally used.
In so doing, it will expand the landfill vertically, without increasing its footprint, Environment Minister Aaron Farrugia said.
Once completed, the wall will be 667m long and be constructed out of 315,000 tonnes of waste - effectively extending the rapidly filling landfill's lifespan by around one year.
Farrugia inaugurated the project during a visit to the site together with WasteServ CEO Richard Bilocca.
He said that the technique would allow Malta to make the most use of its landfill space until work to construct a waste-to-energy incinerator was completed, as part of the so-called Ecohive waste management project.
Malta remains far behind its EU-mandated waste management targets: it is one of the heaviest European users of landfills and managed to recycle just one per cent of its plastic waste in 2019.