Inros Lackner has been regularly planning and managing projects in the port city of Pointe-Noire in the Republic of the Congo since 2007. An important current project, which is part of a major extension of the port to the east, involves the creation of a new piece of land of area 360,000 m2 (length approx. 800 m, width approx. 450 m excluding slopes). It also includes filling of the “lagoon”, with an area of roughly 151,500 m2. In total, the project involves the movement of approximately 3,200,000 m3 of material. This requires in-depth knowledge and experience of “bituminous sands” in a construction area - the “pockets”, “veins” and “seams” that formed throughout the earth’s history at different depths and to varying extents, depending on the compactness of the soil, in which mineral oil mixed with sand. Since bituminous sands may be encountered at any time, due to the inhomogeneity of the soil, a protective barrier must be formed around the entire construction area. This will create, in a first step, a large basin which will be used for the removal of heavily contaminated material while soil containing less bitumen/oil is used to extend the dam. In addition to supervising/monitoring the construction, Inros Lackner’s responsibilities also include visually assessing the excavated material and determining how it should be used, and raising an alarm should significant quantities of bitumen be encountered.
In order to minimise the escape of released oil particles, oil barriers with a total length of approximately 4 km will be placed around the excavation zone (excavation capacity: 3,000 m3/hr) and around the stage-by-stage soil treatment zones. The proper functioning of these barriers, and appropriate maintenance measures, shall be regularly assessed, notified and monitored, and the surrounding beaches will be walked to check for traces of oil and bitumen. The excavated material will be transported away exclusively by pipeline: some floating, some subsurface and some on land. To avoid expensive soil cleaning measures, the bituminous materials resulting from each excavation and treatment phase will be removed immediately.