The World Bank has agreed to loan India $1 billion to help clean the Ganges river, sacred to hundred of millions of Hindus and also one of the most polluted rivers in the world.

“The bank would be honored to help and support India’s renewed endeavour to revitalize this uniquely important river,” World Bank President Robert Zoellick said.

The loan to clean up the 1,550-mile (2,490 km) river will be spread over the next five years, he said in a statement released late Wednesday.

Scientists say massive amounts of human and chemical waste have devastated the river, which spills from a Himalayan glacier and cuts through India’s plains before flowing into the Bay of Bengal.

Earlier this year the Indian government set up a National Ganga River Basin Authority as part of a plan to ensure that by 2020 no untreated sewage or effluents will be discharged into the river. The government estimates that nearly $4 billion will be required to meet the target.

More than 350 million people across several Indian states live in the river’s watershed.

This is not the first time that officials have launched an ambitious plan to clean the massive river.

In the late 1980s, the government launched a Ganges Action Plan and spent $300 million over the next two decades but achieved little.