Volume Two 17. Open Space 1 Zone 17.2.7. Dust from any process vent or stack. 17.2.7.1. The dust must not contain hazardous substances. 17.2.7.2. 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. 17.2.7.3. Dust particles must not exceed 0.05mm size in any direction. 17.3. Standards that apply to specific permitted activities 17.3.1. Planting of vegetation. 17.3.1.1. Only indigenous species must be planted in, or within 8m of, a Significant Wetland. 17.3.2. Indigenous vegetation clearance. 17.3.2.1. Indigenous vegetation clearance must comply with Standards 17.3.3.1 to 17.3.3.4 (inclusive). 17.3.2.2. The clearance of indigenous vegetation in the following circumstances is exempt from the Standards 17.3.2.3 and 17.3.2.4: (a) indigenous vegetation dominated by manuka, kanuka, tauhinu, bracken fern and silver tussock, and which has grown naturally from previously cleared land (i.e. regrowth) and where the regrowth is less than 20 years in age; (b) indigenous vegetation dominated by matagouri, and which has grown naturally from previously cleared land (i.e. regrowth) and where the regrowth is less than 50 years in age; (c) where the clearance is associated with the maintenance of an existing road or track. 17.3.2.3. Clearance of indigenous vegetation must not occur on a Threatened Environments – Indigenous Vegetation Site. 17.3.2.4. Clearance must not exceed 2000m 2 per Computer Register in any 5 year period. 17.3.3. Non-indigenous vegetation clearance. 17.3.3.1. Vegetation must not be removed by fire or mechanical means within 8m of a river (except an ephemeral river, or intermittently flowing river when not flowing), lake, Significant Wetland or the coastal marine area. 17.3.3.2. Wheeled or tracked machinery must not be operated in, or within 8m of, a river (except an ephemeral river or intermittently flowing river, when not flowing), lake, Significant Wetland or the coastal marine area. 17.3.3.3. Within, or within 8 metres of, a Significant Wetland, Pest Plants identified in Appendix 25 and willow, blackberry, broom, gorse and old man’s beard are the only vegetation that may be removed. Any vegetation removed under this Standard must only be cleared by non-mechanical means. 17.3.3.4. Woody material greater than 100mm in diameter and soil debris must: (a) not be left within 8m of, or deposited in, a river (except an ephemeral river or intermittently flowing river, when not flowing), lake, Significant Wetland or the coastal marine area; 17 – 3