The European Commission gave Italy on Thursday two months to comply with EU landfill laws, accusing authorities of improperly treating waste dumped in Rome's biggest garbage site.

Warning that failure to properly treat waste threatens human health and the environment, the European Union's executive arm threatened to take Italy to court, where it would face fines, if it fails to abide by the rules.

The commission said an EU investigation found that some waste in the Malagrotta landfill in the Lazio region, and possibly other sites in the area, was dumped without being treated.

Considered Europe's biggest landfill, Malagrotta receives 4,500 tonnes of trash per day.

"Due to a narrow interpretation of what constitutes sufficient pre-treatment of waste by the Italian authorities, the Malagrotta landfill in the Lazio region contains waste that has not undergone the required pre-treatment," the commission said.

Italian authorities argue that the waste is treated because the garbage is crushed before being landfilled, according to the commission.

But the commission says trash must go through mechanical-biological treatment to stabilise its organic content in order to reduce the risk of pollution.

"A significant amount of waste is landfilled without undergoing an adequate treatment," the commission said.

Italy, which has struggled with waste management in the Naples area for years, is already facing the threat of EU fines over heaps of garbage in that part of the country.