About 51 million people in the DRC don't have access to safe drinking water despite the country's vast water reserves.
Hassan Partow, the program director for the U.N. Environment Program in DRC, said the government since a peace deal in 2003 managed to make great strides in improving trends in water coverage.
"However, the stark reality is that the DRC has one of the fastest urbanization growth rates in the world and this is not being matched with adequate water and sanitation service delivery," he said in a statement.
An assessment from the U.N. Environment Program and the U.N. Human Settlements Program found that 40 percent of the 1 billion people in Africa live in locations without adequate sanitation or water supplies.
The number of Africans in urban areas without access to safe drinking water increased from 30 million in 1990 to more than 55 million in 2008, UNEP added.