Livemint. Ahead of Diwali, CAQM invoked Stage III of GRAP across Delhi-NCR as a precaution against worsening pollution. The curbs include bans on many construction activities, older vehicles and. The air quality in Delhi has deteriorated into the ‘severe’ category, with the Commission for Air Quality Management (CAQM) imposing Stage III of the Graded Action Plan or GRAP due to the.