Volume Two 23. Airport Zone 23.3.15. Discharge of contaminants to air from the burning of solid fuel in an enclosed pellet burner. 23.3.15.1. The burner must comply with the stack requirements of Appendix 8 – Schedule 2. 23.3.15.2. The burner must only burn fuels approved for use in the burner. 23.3.16. Discharge of heat and water vapour from cooling towers. 23.3.16.1. No more than 5MW of heat per hour must be discharged. 23.4. Discretionary Activities Application must be made for a Discretionary Activity for the following: [R, D] 23.4.1. Any activity provided for as a Permitted Activity that does not meet the applicable standards. [D] 23.4.2. Any use of land not provided for as a Permitted Activity or limited as a Prohibited Activity. [R] 23.4.3. Any discharge of contaminants into or onto land, or to air, not provided for as a Permitted Activity or limited as a Prohibited Activity. 23.5. Prohibited Activities The following are Prohibited Activities for which no application can be made: [R] 23.5.1. Discharge of contaminants to air arising from the burning of any of the following materials: (a) wood having a moisture content of more than 25% dry weight; (b) wood which is painted, stained, oiled or coated; (c) wood treated with preservatives or impregnated with chemicals, including but not limited to, wood treated with Copper-Chrome-Arsenic; (d) pellets containing greater than 10 mg/kg (dry) of copper and 0.02 w-% (dry) of chlorine; (e) composite wood boards containing formaldehyde or similar adhesives, including but not limited to chip board, fibreboard, particle board and laminated boards; (f) metals and materials containing metals including but not limited to cables; (g) materials containing asbestos; (h) material containing tar or bitumen; (i) all rubber, including but not limited to, rubber tyres; 23 – 11