The financing agreement for US$12mn, provided by French development agency AFD, will serve to implement a technical assistance program to support water and waste projects.
The Argentine government signed a loan deal with French development agency AFD to fund water works intended to benefit nearly 500,000 people in the country's northern provinces.
Some 13 Brazilian states have now joined the program.
The Chilean project includes a desalination plant and expanded processing infrastructure to face drought and ever-harder ore.
The award of the contract follows legislative approval last month of the last of two loans needed to finance the works to rehabilitate San Salvador's Las Pavas plant.
The first studies for the Cayambe-Pedro Moncayo irrigation system took place in the 1970s, while an attempt to carry out the project ended with works being suspended for a decade until 2010.
This year the government will invest US$19mn on water and sanitation works in the department, although this is considerably lower than the US$33mn investments made last year.
The utility, serving Brazil's Minas Gerais state, is investing 28mn reais in the project.
Since 2012, the government has invested over US$58mn in this program, which consists of installing domestic water and sewerage connections for low-income homes.