Despite hundreds of crores of rupees being spent to clean the Ganga, the lifeline of north India, pollution levels in the river have reached septic levels at certain points with dissolved oxygen dropping to alarmingly low levels.

"In Varanasi alone, the seven km stretch from upstream Assi Ghat to Varuna Sangam, pollution has reached septic levels and we have data to prove this point," Hydraulic expert and Professor Vir Bhadra Misra said.

Misra said the samples tested by laboratories set up under the 'Clean Ganga Campaign' of the Sankat Mochan foundation, of which he is the head, show that the river is dirty in the upstream Assi Ghat area and by the time it reaches Varuna Sangam, it attains septic levels.

"We had set up these labs along the river ever since it was claimed by the authorities that the water in the river has been cleaned following the Ganga Action Plan," the former Civil Engineering Department head at the Banaras Hindu University said.

Misra, who was recently honoured by the Council of Science and Technology with Vigyan Ratna award, said he had formulated a plan for the Varanasi Nagar Nigam way back in 1995 to clean the river using low cost gravitational force method to stop inflow of domestic sewage into the river.

Sewage inflow is one of the main causes for pollution. The project was aimed at not only stopping the inflow of sewage into the river from the banks but also to treat it in a manner so as to make it fit for reuse.

Although Misra's plan continued to gather dust, he is still upbeat after being invited to New Delhi on November 6 last year by Prime Minister Manmohan Singh [Images] and his 'important' meeting with Union Secretary for Environment and Forests on February 29 last.

"Almost 95 per cent of the pollution in the river is caused at point sources at which sewers and open drains bringing pollutants in domestic and municipal limits fall, while only five per cent is by the direct users, especially in the case of rivers like Ganga, which were in constant use for religious reasons," Misra said.

"In Varanasi alone 32 drains fall in the river, in Kanpur 22 and in Allahabad there are 40 point sources in the Ganga," he said.

Explaining the process used in his proposed project to clean Ganga in Varanasi, Misra said the sewage carrying drains would be intercepted in a water tight drain all along the river and directed to four large ponds for treatment set up outside the city.

These four large ponds have been specially designed with the assistance of experts from University of California, Berkeley, which would be used to treat the polluted water. The activated sludge plant and UASB (up flow Anaerobic sludge blanket) the two main methods of water treatment currently in use have not been proved to be effective enough,
besides they also consume heavy electricity making them costly, he said.

Misra said his project was not only more effective but also requires very low maintenance and was cost effective. Misra said with the assurance from higher authorities during his New Delhi visit last year he is hopeful that his project could be utilised for dealing with the massive pollution levels in Varanasi.