In October 2015, NGT had directed the Central Pollution Control Board (CPCB) to institute a proper mechanism to check emission levels of moving, overloaded, heavy vehicles.

Petitioner Neena Pradeep alleged the cement makers were violating the NGT order by overloading trucks with cement and clinker to save on toll.

A bench headed by NGT chairperson justice Swatanter Kumar issued the notices. The case will be heard next on 6 April.

The petitioner also said the companies transport cement by road to cut costs, despite having exclusive railway sidings.

“The ministry of railways should target maximum dispatches of cement and clinker by railways so that air pollution can be controlled in the city,” the petition said.Mint has seen a copy of the petition.

In December 2014, the CPCB identified 17 sectors as highly polluting, including the cement industry. Some of the other sectors in the list are iron and steel, thermal power plants, sugar, tanneries, distilleries, fertilizers and pesticides.

An April 2015 order of the NGT, in a case related to air pollution, said an estimated 80,000 trucks enter the capital every day. On 5 January, the Supreme Court had barred heavy commercial vehicles from entering Delhi from national highways 2 (Delhi-Kolkata), 10 (Punjab-Delhi) and 58 (Uttarakhand-Ghaziabad-Delhi) as well as state highway 57 (Baghpat-Ghaziabad-Delhi), in a bid to curb air pollution.

The apex court had in December last year also doubled entry tax on trucks into the city and taken 10-year-old diesel commercial vehicles off the city’s roads.

The 13 cement manufacturers are Shree Cement Ltd, J.K. Cements Ltd, ACC Cements Ltd, Binani Cement Ltd, Birla Corp. Ltd, Gujarat Ambuja Cement Ltd, Heidelberg Cement India Ltd, J.P. Cement, J.K. Lakshmi Cement Ltd, Maihar Cement Ltd, Mangalam Cement Ltd, Wonder Cement Ltd and Ultratech Cement Ltd.

According to lawyer Abhishek Vikram, Shree Cement and JK Cement alone overloaded the trucks to the tune of 200-250% of permissible limits.