A bench headed by NGT Chairperson Justice Swatanter Kumar gave two weeks to them to file their responses and listed the matter on January 15, 2014.
The tribunal was hearing a petition filed by environmentalist Subhas Dutta who has sought "uniform, practical, pragmatic and well-accepted standard operating procedure" for immersion of idols across the country.
"Lakhs of idols are immersed in the rivers and water bodies in the country every year and they are left there to decompose, resulting in damage to the water body and the environment," Dutta told the tribunal.
"Holding immersion processes and throwing idols in rivers and water bodies have become, superfluous, colourful, competitive, not backed by religious necessity," the petition has said.
In his petition, he has sought setting up of a high powered committee to monitor idol immersions in the country.
He has also suggested that while coming up with the uniform policy for immersion of idols, religious gurus, environmental experts, social activists and scientists be also consulted.