The sand extraction area for Maasvlakte 2 is located some 11 kilometres off the Dutch coast. For sand extraction purposes, the area has been divided into a grid. The trailing suction hopper dredgers are systematically dredging the seabed, section by section. The quality of the dredged sand is recorded, with the grain size being the primary determining factor. Once the hold (the bin) is filled with sand, the trailing suction hopper dredger sets course back to the Maasvlakte to unload the sand. The grain size is once again important when selecting which area the sand will be transported to. The finer grains of sand are ideal for the interiors of the sand bodies. In contrast, the outer area, where the beach and dunes have been planned, requires a larger grain of sand. This sand will be able to stay in place better and withstand the tug of tides and wind. The extraction and the area of destination are carefully recorded. This information can be used as input to effectively monitor whether the quality of the work satisfies the strict standards set for it.
The best location for the sand extraction activities was determined after extensive research. Due to the many limitations, this was not an easy task. For example, the location needed to take account of nature areas, munitions dumping grounds, military practice areas, pipeline and cable corridors and archaeological sites. But neither were the future sites of wind parks an option. Moreover, the busy shipping traffic off the Dutch coast needed to have constant safe passage. Ultimately, the contractor decided on a location for the sand extraction area that was even relatively close to Maasvlakte 2. This considerably reduces transport time and as a result emissions.
Usually, sand is extracted to a depth of two metres. To construct Maasvlakte 2, this would mean digging up an 11 by 30-km section of the North Sea seabed. In order to impact a smaller section of the seabed, and as a result the marine ecology, the sand for Maasvlakte 2 will be dredged to a depth of 20 metres.
The extraction of sand at sea has an impact on the life on and in the sea floor and on the movement of water around the sand extraction site. The effects of the sand extraction activities have been studied in detail in connection with the construction permits for Maasvlakte 2. The most important effect of the sand extraction activities is the release of silt. This means that during the activities, local water will temporarily become murkier. Sound can also have a disruptive influence, both above and beneath the waterline. The expected effects have been judged to be ‘insignificant'. To determine the actual effects, these are continually monitored throughout the construction. Major projects in the Netherlands are always preceded by an Environmental Impact Assessment (EIA). This mandatory procedure describes the consequences of a plan for the environment and the surrounding area. For Maasvlakte 2, the EIA describes among other things the effects of the sand extraction activities. The EIA also describes measures aimed at reducing negative effects and possible compensation.