“The mineral wealth of a country should be used for the benefit of the people, including the workers, and not to destroy the environment for the benefit of the corporations and politicians,” Gerard and Gómez Urrutia said in their statement.

Grupo Mexico denies the accusations. In a press release published in Peru’s El Comercio last week, Grupo Mexico, Mexico’s largest mining and infrastructure consortium, said that the Tía María project has complied with all the permits required and has taken into account the communities by setting up a mechanism of public consultations and citizen participation.

Peru’s Energy and Mines Ministry said in April that Southern Copper has guaranteed that it won’t touch water to be used for farming, and that dust from the mining process will also be controlled.

In its statement, Grupo Mexico reported that the Tía María mine will only use ocean water from a new $95 million dollar desalinization plant built 25 kilometers away.

The Peruvian government approved the environmental impact assessment for the Tía María project in 2014. Before the truce, Grupo Mexico said that itexpected the project to begin operating in mid 2017.

It is not clear if Grupo Mexico will scrap the project all together. Southern Copper’s spokesman in Peru, Julio Morriberon, announced in late March that the company was cancelling the project, because it had grown tired of ongoing “anti-mining terrorism” in the area, but his comments were amended by Grupo Mexico’s top executives. Southern Copper’s CEO Gonzalez Rocha told Reuters that Morriberon’s announcement “did not totally reflect the intention of the board.”

This is not the first time that mines owned by Larrea, Mexico’s second richest person, have run into opposition from local communities. Last year, Grupo Mexico created a political storm after one of its mines in northern Mexico caused the worst ecological disaster in Mexican history.

German Larrea Mota Velasco is currently worth an estimated $14.6 billion, according to Forbes. He ranked number #77 on Forbes 2015 World’s Billionaires list.