Gurugram, Oct. 29 -- The Haryana State Pollution Control Board (HSPCB) has issued closure notices to 225 construction and demolition (C&D) sites in Gurugram north over the past week for failing to register on the dust-monitoring portal and comply with norms, officials said. The action follows the implementation of Stage 1 of the Graded Response Action Plan (GRAP) across Delhi-NCR on October 21 amid deteriorating air quality after Dussehra. Gurugram has more than 900 active C&D sites, which must follow dust-mitigation measures prescribed by the Commission for Air Quality Management (CAQM). Officials said further action could follow if the sites failed to comply. Under CAQM directions, projects on plots measuring 500 square metres or more must register on the state's dust-mitigation portal and install geo-fenced pan-tilt-zoom (PTZ) cameras and low-cost PM2.5 and PM10 sensors. Live camera feeds must be linked to the HSPCB portal and CAQM's integrated command centre in Delhi. The latest notices follow a series of enforcement drives conducted since September. On September 10, HSPCB issued notices to more than 400 sites in southern Gurugram after inspections found missing cameras, interrupted live feeds, non-functional sensors and inadequate camera coverage. Around 350 sites later complied with requirements, while 34 were recommended for closure after failing to rectify violations. Last week, the board also recommended closure of 13 sites for lacking the required cameras and sensors. Officials said that Gurugram then had 974 identified active C&D sites, of which 898 had cameras linked to the portal, but only 524 had air-quality sensors installed....