The plan is based on studies carried out by the country's competition agency and proposes the execution of a number of road projects, some of which could be PPPs.
The company has introduced so-called sequencing batch reactors in two sewage treatment units.
Some US$60mn will be used to improve two highways in the state.
The new cabinet chief pledged increased public spending to spur billions of dollars in infrastructure projects over the next two years.
The agreement states that utility Essal will increase the capacity of the Panguipulli wastewater system, where local authorities blamed the firm for pollution of a local lake.
The winning consulting firm will design the new concession for El Loa airport in the Antofagasta region.