The water utility also wants to grant subsidies based on personal need, not area of residence.
The concession for the Ferrovia Norte Sul project is held by state-run company Valec Engenharia, which will allow a private player to operate it through a sub-concession.
Vinci Airports is the latest to tap foreign construction firms or SMEs in order to avoid contracting companies that have been targeted by Brazil's anticorruption investigation.
Brazil's government has promised to step up financing for the recovery of the São Francisco river basin with funds from Eletrobras' privatization, if northeastern lawmakers support the sale.
The Colombian lender - a unit of Scotiabank - is targeting the country's huge road-building program and aiming to strengthen its digital muscles.
The first stretch of the US$64mn corridor was expected to be operating next month.
Once completed, the station will be one of the largest in the state capital's metropolitan region.