A bench headed by Justice Swatanter Kumar sought response from all of them after the counsel for Uttarakhand government told the tribunal that certain people were carrying on illegal sand mining.
"We issue show cause notice to all the 24 persons who have been found by the state government to be carrying on illegal mining activity in district Haridwar," the bench said.
It also held that in terms of the provision of the Section 15 of the NGT Act, they are to be held responsible for causing damage to environment and ecology.
The bench also issued notices to the chief secretaries of Karnataka, Andhra Pradesh, Jammu Kashmir, Nagaland, Maharashtra, Telagana and Arunachal Pradesh to ensure that they are present on the next date of hearing.
"In the event of default, we will be compelled to issue bailable warrants against the chief secretaries of all these states," the bench said.