A new proposed railway to connect Zambia’s copper mines with the Lobito port in Angola will cost up to $5 billion, according to projections in an environmental study.

Construction of the 516-mile (830-kilometer) line is set to begin this year and is expected to be completed by 2030, a new report from the Zambia Environmental Management Agency said.

Africa Finance Corporation is the lead developer of the project, with funding commitments from the African Development Bank. The US is providing $553 million in funding to upgrade the existing railway line in Angola that runs from the Lobito port to the border with DR Congo, but it is not yet clear whether it will offer additional funding for the link into Zambia.