The contract is worth some 17.4mn euros (US$24.6mn), Acciona Agua said in a release.
The plant will have an average flow of 34,800m3/d. Construction of the plant and an 800mm-diameter intake collector is scheduled to take 22 months.
The facility will serve an initial population of 150,000, which is expected to increase to 240,000 by 2036 and will help reduce contamination of the Chili river. The plant will remove 90% of the contamination load from treated wastewater, which will eventually be used to irrigate local farms.
The plant is Acciona Agua's third project in Peru. The company built a desalination plant in 2002 and is currently working on the La Chira wastewater treatment plant in southern Lima.
Private investment promotion agency Proinversión awarded Acciona Agua and local construction firm Graña y Montero the La Chira concession at end-2010. That contract is worth some 280mn euros, the release said.