The mining giants BHP and Vale have signed a deal with the Brazilian government to pay nearly $30bn (£23bn) in compensation for the Mariana dam collapse in 2015 that caused the country’s worst environmental disaster.

Brazilian President Luis Inacio Lula da Silva attended the signing of the deal on Friday.

The dam collapse released toxic waste and mud, which flooded nearby towns, rivers and forests.

It killed 19 people, left hundreds others homeless, and poisoned the river.

President Lula said: “I aspiration the mining companies have learned their lesson; it would have expense them less to prevent the disaster.”

The dam was owned by Samarco, a joint assignment between Vale and BHP.

Since the disaster, the companies have set up a foundation to compensate people, which has already carried out billions of dollars’ worth of repairs. This included building a recent town to replace one of the towns that was destroyed.

However, many people in the throng were still arguing they had not received fairness or enough to rebuild their lives nine years on.

Separately to these legal proceedings in Brazil, more than 620,000 people had taken BHP to court in the UK, where BHP was headquartered at the period, in a trial that started earlier this week.

• ‘Nothing can bring a life back’: Brazil dam collapse survivors talk as UK trial begins

They are seeking about $47bn in damages in the civil trial. The first stage of it will determine if BHP – as a parent business – was liable. About 70,000 complainants are also taking Vale to court in The Netherlands.

Both companies deny obligation and debate that this overseas legal action is “unnecessary” and duplicates legal proceedings in Brazil.

Some members of the throng in Mariana had told the BBC they had joined the UK legal action after frustration that the Brazilian proceedings were taking too long, but suspected that the Brazilian settlement may be reached soon after the UK case opened due to more international pressure.

In 2016, both companies agreed to pay about $3.5bn in today’s rate in compensation but negotiations were reopened in 2021 due to the leisurely advancement of Brazil’s fairness structure in resolving the dispute.

Friday’s agreement covers their history and upcoming obligations to assist people, communities and ecosystems affected by the disaster.

The companies agreed to pay 100bn reais ($17.5bn; £13.5bn ) to local authorities over 20 years and 32bn reais towards compensating and resettling the victims and repairing the damage caused to the surroundings.

The remaining 38bn reais is the amount the companies declare they have already paid in compensation.