Stage 1 FOGO Hardstand Scope of Works
Clear vegetation and prepare subgrade for clay placement. The surface shall be smooth, free of debris, roots, sticks and sharp rocks. The subgrade shall be compacted using a sheepsfoot roller before any fill is placed.
Fill shall be compacted to 95% of its maximum dry density in layers not exceeding 300mm to the levels shown on the attached drawings. Upon completion of the fill placement the top 300mm will be tested by Nuclear Density Meter to confirm compaction and permeability.
A 100mm ferricrete layer shall be placed on top of prepared hardstand and compacted with a smooth drum roller.
0.5m high ferricrete bunds shall be placed around the perimeter of the hardstand to prevent any stormwater ingress.
A leachate collection sump shall be constructed to capture leachate runoff from the hardstand. The sump shall be constructed with a minimum 500mm clay liner and a 2mm HDPE Layer.
The sump shall be suitably sized to handle a 24 hour 1 in 100-year storm event which will immediately be pumped to the site leachate ponds.
Pumping infrastructure to be in place and shall have a float system to automatically start and stop the pumps as levels in the sump rise and fall.
The sump shall be monitored every day rain fall is occurring to ensure a 500mm freeboard is maintained at all times.
