The department shot off a letter two days ago to the twin civic bodies after they failed to respond to previous notices issued by HSPCB on the matter. "Please send the details of action taken in compliance with the NGT order," the letter read.

The HSPCB had written to Huda on November 17, 2016, and January 6 this year but the urban development body failed to submit a compliance report. Last month, HSPCB had given Huda A final reminder to submit a status report and asked it to give top priority to the 'sensitive matter', being monitored regularly by the NGT, the ministry of environment, the Environment Pollution (Prevention & Control) Authority and the Central Pollution Control Board.

But Huda failed again, prompting HSPCB to nudge the department, under which Huda and MCG fall.

Construction activities, burning of waste and traffic congestion are considered major reasons for Gurgaon's high air pollution levels. Huda and MCG are expected to initiate comprehensive steps to tackle changes, following the NGT guidelines.

"Huda and MCG have to submit compliance reports on steps they have taken to curb pollution. It is the responsibility of Huda and MCG to ensure implementation of NGT directives and take action against violators, if any," said an HSPCB official.

In this regard, CPCB had issued directives on December 29, 2015, under Section 18(1)(b) of the Air Act, 1981, for prevention and control of air pollution, and improvement of air quality in Delhi and NCR.

Later, in its order dated November 10, 2016, with regard to the Vardhaman Kaushik case, NGT had constituted a monitoring committee.