GRAP II measures include regular mechanical cleaning of roads, water sprinkling and the use of anti-smog guns to reduce dust. The enforcement of the pollution control is being jointly carried out by the Delhi Environment and Transport Departments, along with the traffic police. Grap-II Pollution Curbs In Delhi As Air Quality Slips To 'Very. GRAP Stage II has been implemented in Delhi-NCR due to a significant decline in air quality.