The National Green Tribunal today asked the Centre to clarify what should be the minimum environmental flow (E-flow) in the Ganga, in a bid to ensure uninterrupted water supply in the river.
The E-flow defines the quantity, timing and quality of water flow required to sustain freshwater and the estuarine ecosystems, besides human livelihood.
A bench headed by NGT Chairperson Justice Swatanter Kumar directed the Environment Ministry, Ministry of Water Resources and the Central Pollution Control Board to provide complete information on e-flow to be maintained in the river.
It asked them to apprise the green panel about extraction of groundwater in the stretch of 543 km between Haridwar and Unnao, and state whether the water being diverted into the various canals should be regulated so as to help maintenance of minimum flow of the river.
"Ministry of Environment and Forests, Ministry of Water Resources and CPCB will take a clear stand as to what should be the minimum environmental flow of river Ganga in Segment-B (Haridwar and Unnao)," the bench said.
The NGT fixed the matter for hearing on April 19.
Earlier, the Yogi Adityanath-led Uttar Pradesh government favoured the shifting of British-era tanneries releasing toxic wastes into the river Ganga at Kanpur.
The UP government had told the NGT that the hunt for a new site for setting up of these leather units, which are the "major source of pollution" in Ganga, was under consideration and would be identified soon.
In a detailed report covering various aspects of contamination in the river, CPCB had informed the NGT that the Ganga, spanning a distance of 543 km between Haridwar and Kanpur, was affected by 1,072 seriously polluting industries which were releasing heavy metals and pesticides.
At present, 823.1 million litres per day of untreated sewage and 212.42 MLD of industrial effluent flows into the river while three of the four monitored Sewage Treatment Plants were non-compliant with the set standards, it said.
The green panel has divided the work of cleaning the river in different segments - Gomukh to Haridwar (Phase-I), Haridwar to Unnao (termed as segment B of Phase-I), Unnao to border of Uttar Pradesh, border of Uttar Pradesh to border of Jharkhand and border of Jharkhand to Bay of Bengal.