19. Open Space 3 Zone Volume Two 19.2.5. Dust. 19.2.5.1. The best practicable method must be adopted to avoid dust beyond the legal boundary of the area of land on which the activity is occurring. 19.2.6. Dust from any process vent or stack. 19.2.6.1. The dust must not contain hazardous substances. 19.2.6.2. The particulate discharge rate from any air pollution control equipment and dust collection system must not exceed 250mg/m at any time, corrected to 0°C, 1 3 atmosphere pressure, dry gas basis. 19.2.6.3. Dust particles must not exceed 0.05mm size in any direction. 19.3. Standards that apply to specific permitted activities 19.3.1. Recreational event or special event. 19.3.1.1. The event must not exceed three consecutive days duration. 19.3.1.2. Where a site immediately adjoins or is located across a road from any land zoned Urban Residential 1, Urban Residential 2 (including Greenfields) or Urban Residential 3, the activity must not be conducted on the site between the hours of midnight and 7am. 19.3.1.3. All structures and other works accessory to the event must be removed and the site returned to its original condition within 5 working days after the activity has ceased. 19.3.1.4. If access is to be directly off a State Highway, approval from the Road Controlling Authority must be provided to the Council. 19.3.2. Conservation planting. 19.3.2.1. The following species must not be planted: (a) Douglas fir (Pseudotsuga Menziesii ); (b) Lodgepole pine (Pinus contorta ); (c) Muricata pine (Pinus muricata ); (d) European larch (Larix decidua ); (e) Scots pine (Pinus sylvestris ); (f) Mountain or dwarf pine (Pinus mugo ); (g) Corsican pine (Pinus nigra ); 19.3.2.2. There must be no planting of vegetation which will mature to a height exceeding 6m within 30m of a formed and sealed road. 19.3.2.3. There must be no planting within the Wairau Dry Hills Landscape. 19.3.2.4. Only indigenous species must be planted in, or within 8m of, a Significant Wetland. 19.3.3. Indigenous vegetation clearance. 19.3.3.1. Indigenous vegetation clearance must comply with Standards 19.3.4.1 to 19.3.4.6 (inclusive). 19.3.3.2. The clearance of indigenous vegetation in the following circumstances is exempt from Standards 19.3.3.3 to 19.3.3.5 (inclusive): 19 – 4