DREDGING is cleaning out the bed of a body of water by scooping out silt, mud, trash or other materials.
Each year, more than 100 million cubic tonnes of material is pumped into the Fly River by Ok Tedi mining operation.
Some of these material are contaminated and deposited in confined disposal facilities but a significant amount of it can be reused.
The dredged material can be reused as:
- WASTE product – sand can be used for beach nourishment, to enhance existing beaches where the shoreline is threatened by erosion or to create new beaches. It can be used in combination with geotextile tubes to build out flood defences on beaches. Finer materials such as clay and fine dirt have many uses. Fine clay material can be used for land creation and construction fill, especially for new land areas within harbours and ports. Fine dirt is often mixed with additives such as manure, biosolids or compost to create or enhance topsoil.
- RECOVERED product or by-product – harvesting of peat moss, which is used throughout the world as fuel or to enhance soil. Recover biosolids or organic materials made from sewage to create fertiliser;
- PRIMARY product – sand is gathered for a range of production purposes, including the making of glass or as a component in mortar; and,
- FINE granules including precious metals such as gold.