Flowing along south of Buenos Aires, Argentina’s capital city, the Matanza Riachuelo River leaves one of the world's most polluted urban areas and empties into the River Plate. To remediate this hazard, a $1.25-billion system now under construction will channel pre-treated wastewater to the end of a 12-km outfall into the River Plate, where Italian engineers deployed innovative pipe jacking equipment to push effluent riser tubes up though some 30 meters of riverbed.
It took two years for Milan-based outfall contractor Webuild S.p.A. to develop vertical pipe jacking rigs able to operate inside a tunnel. The undisclosed investment was made to replace the owner’s option of forming the risers from the river surface, says Nicola Valiante, the contractor’s head of design. Marine work can be “highly risky in terms of safety and construction schedule,” he adds.