The work had originally been assigned to another contractor.
The contract is for Lot 2 of the US$1.2bn Riachuelo system, a major scheme being commissioned by Agua y Saneamientos Argentinos to reduce pollution in the country’s most polluted river.
Salini Impregilo Group is already involved in Lot 3 of the clean-up of the Matanza Riachuelo River Basin.
The new project will see Fisia Italimpianti develop, within a 36-month period, a pre-treatment wastewater plant and accompanying pumping stations with a capacity of 27 cubic metres per second, making it one of the biggest plants of its kind in the world.
On completion in 2022, the Riachuelo system will treat 2,332,800 cubic metres of wastewater a day.