Enviroway told government officials to introduce biochemical treatment methods to clean the drains that will be cost effective and eco-friendly.

Ganga is highly polluted despite being considered sacred by Hindus. About 30 large drains here discharge about 190 million litres of untreated sewage and garbage into the the river every day.

Tested samples of the water revealed a high presence of coliform bacteria. "Garbage is dumped into the river, contributing to the growth of the bacteria," a scientist said.

A latest research has revealed that Ganga water is unfit for agricultural purposes also.

A joint team of army and air force officers had completed a journey from Allahabad to Patna through the river route Last year.

Members of the team said they were shocked at the filthy condition of the riverbanks, the garbage dumping and the flow of untreated sewage water into the river.

"We came across dozens of half-burnt bodies and corpses floating in the river. We also came across animal carcasses and heaps of polythene bags," a team member said.

According to an estimate of the environmental science department of A.N. College here during the river's 2,510-km-long journey from Gaumukh to the Bay of Bengal, nearly 1 billion litres of untreated sewage gets disposed into the river.