The green panel, in a detailed judgement, had passed a slew of directions to rejuvenate Ganga, declaring as 'No Development Zone' an area of 100 metres from the edge of the river between Haridwar and Unnao and prohibiting dumping of waste within 500 metres from the river.
A bench headed by NGT Chairperson Justice Swatanter Kumar also asked all the stakeholders to state what course of action they propose to take in relation to Phase-2 from Kanpur to the UP border.
"We make it clear that in the event now the compliance is not made, to the directions of the tribunal, we will be compelled to pass coercive orders. Let copy of this order be provided to the chief secretaries of UP and Uttarakhand.
"All the counsels appearing for their respective clients will inform these directions to them. Copy of this order, also, be sent to DG of National Mission for Clean Ganga; Secretary, Ministry of Water Resources and Secretary, Ministry of Environment, Forest and Climate Change for compliance," the bench said.
The matter is listed for next hearing on October 24. The tribunal had earlier, in a detailed judgement, said the government has spent over Rs 7,000 crore in two years to clean the Ganga which still remains a "serious environmental issue".
'No-development zones' are areas where no construction including commercial or residential buildings can come up.
It also imposed a complete prohibition on disposal of municipal solid waste, e-waste or bio-medical waste on the floodplains or into the river and its tributaries.
The tribunal reiterated its earlier order of ban on mechanical mining in Ganga and said "no in-stream mechanical mining is permitted and even the mining on the flood plain should be semi-mechanical and preferably more manual."