Chapter 33 - Port Zone d) The activity does not result in any discharge or deposition of contaminants into the coastal marine area. e) The addition or alteration is contained either within the form of the existing structures, or adds no more than 5% to the plan or cross-sectional area of the structure within any 24 month period; 33.1.2.5 Demolition or Removal of Structures Any removal or demolition of any structure or any part of a structure that is fixed in, on, under or over the coastal marine area is a Permitted Activity provided that the activity conforms to the following conditions: a) All material removed or demolished from the structure is removed from the coastal marine area; b) The activity shall not involve any excavation of foreshore or seabed greater than 1 metre in depth or greater than 100m in volume; and 3 c) No foreshore or seabed material shall be removed from the site. 33.1.2.6 Drilling Disturbance and damage of foreshore and seabed associated with any drilling operation is a Permitted Activity provided that the activity conforms to the following: a) The diameter of the drilled hole shall not exceed 600mm; b) The activity shall be undertaken in a manner which minimises water turbidity; and c) The activity shall not involve any significant adverse effect on any significant flora or fauna. 33.1.3 Land Disturbance 33.1.3.1 Land Disturbance General Any land disturbance activity which meets the conditions below is a Permitted Activity. 33.1.3.1.1 Conditions a) Any increase in the concentration of suspended sediment shall not be more than 20% as measured by the ‘black disk’ method, notwithstanding that the concentration of suspended sediment in run-off water shall not exceed 200 grams/ cubic metre at any point of discharge to any receiving water. The effects on the receiving water are to be measured at a distance downstream of two widths of the receiving watercourse or 50 metres, whichever is the lesser; b) No woody material of greater than 100mm diameter shall be left in any permanently flowing river, lake, wetland or sea as a result of a land disturbance operation; and c) All land disturbance sites are to be stable when subject to a storm event of return frequency probability of 10% or less. 33 - 5