The water quality of the Ganga river has improved at several locations according to an assessment carried out by the Central Pollution Control Board, the government informed the Lok Sabha today.

In a written response to a question, Satyapal Singh, Minister of State for water resources, river development and Ganga rejuvenation, said Dissolved Oxygen levels have improved at 33 locations and is above the primary bathing water quality requirement of 5mg/l. Biochemical Oxygen Demand (BOD) levels and faecal coliforms have decreased at 26 locations and at 30 locations.

The river stretches where improvement has been observed are: Rishikesh, Haridwar, Allahabad Sangam, Kanpur, Varanasi (Assi Ghat), Buxar (Ramrekha Ghat), Patna (Punpun), four locations in West Bengal — Diamond Harbour, Garden Reach, Behrampore and Howrah-Shibpur.

"The comparison of observed water quality in 2017 with the bathing water quality criteria indicates that the Dissolved Oxygen, which is an indicator of river health, has been found to be within the acceptable limits of notified primary bathing water quality criteria," Singh said.    

"BOD is found above acceptable limit in part stretches down stream of Haridwar to Kannauj, at Kanpur, at Allahabad, at Varanasi, some stretches in West Bengal (Behrampore, Serampore, Palta, Dakshineshwar, Howrah, Garden Reach, Uluberia and Diamond Harbour)," he added.

The central government, under the Namami Gange project, has been undertaking steps to rejuvenate the river and its tributaries and sub-tributaries. So far, a total of 221 projects have been sanctioned at an estimated cost of Rs 22,238 crore for various activities.

The Ganga river basin is the largest in India and is spread across four States.