Marlborough Sounds Resource Management Plan b) Notwithstanding the generality of the above condition, no person shall discharge contaminants into air that results in odour beyond the boundary of the premises that, in the opinion of a Council officer, is offensive or objectionabl e. 36.1.7.12 General Rules Relating to Dust Emissions Any person undertaking an activity resulting in the emission of dust shall adopt the best practicable option to avoid adverse effects resulting from the dust emissions on the receiving environment. The discharge of non-toxic dusts from any process vent or stack is a Permitted Activity subject to the following conditions. 36.1.7.12.1 Conditions a) Any air pollution control equipment and dust collection system shall be designed to achieve a particulate discharge rate of 125m/ m³ (corrected to 0 degrees Celsius, 1 atmosphere pressure, dry gas basis) and at no time shall emissions exceed 250mg/ m³ (corrected to 0 degrees Celsius, 1 atmosphere pressure, dry gas basis); and b) No particles in the emission shall be larger than 0.5 millimetres in diameter. 36.1.7.13 Abrasive Blasting Operations 36.1.7.13.1 Non Mobile Source The discharge of contaminant into air from abrasive blasting, other than from a mobile source, is a Permitted Activity provided the following conditions are complied with. 36.1.7.13.1.1 Conditions a) The surface to be blasted shall not contain any lead, zinc, arsenic, chromium, cadmium, copper, mercury, tributyl tin or thorium-based compounds; b) When using dry abrasive blasting techniques, all items shall be blasted within an abrasive blasting enclosure, and air extracted from the enclosure shall be filtered so that there is no visible discharge of dust; c) When using wet abrasive blasting techniques, there shall be no discharge of water spray beyond the boundary of the subject property; d) The discharge shall not raise the ambient dust deposition rate by more than 4g/ m² per 30 days at any point beyond the boundary of the subject property; and e) Sand or any other material used for abrasive blasting shall contain not more than 5% free silica on a dry weight basis, and shall not be reused. 36.1.7.13.2 Mobile Source The discharge of contaminant into air from abrasive blasting using a mobile source and wet abrasive blasting techniques is a Permitted Activity provided the following conditions are complied with. 36.1.7.13.2.1 Conditions a) The surface to be blasted shall not contain any lead, zinc, arsenic, chromium, cadmium, copper, mercury, tributyl tin or thorium-based compounds; 36 - 18