filter and separator, on one or both sides. Various systems are available, each focused on a particular application. The first is known as wick drains in the U.S. and prefabricated vertical drains, PVDs, in Europe. The 100 mm wide by 5 mm thick polymer cores are often fluted for ease of conducting water. A geotextile acting as a filter and separator is socked around the core. The emergence of such wick drains, or PVDs, has all but eliminated traditional sand drains as a rapid means of consolidating fine-grained saturated cohesive soils. The second type is in the form of drainage panels, the rigid polymer core being nubbed, columned, dimpled or a three-dimensional net. With a geotextile on one side it makes an excellent drain on the backfilled side of retaining walls, basement walls and plaza decks. The cores are sometimes vacuum formed dimples or stiff 3-D meshes. As with wick drains, the geotextile is the filter/separator and the thick polymer core is the drain. Many systems of this type are available, the latest addition having a thin pliable geomembrane on the side facing the wall and functioning as a vapor barrier. The third type within this area of drainage geocomposites is the category of prefabricated edge drains. These materials, typically 500 mm high by 20 to 30 mm wide are placed adjacent to a highway pavement, airfield pavement, or railroad right-of-way, for lateral drainage out of and away from the pavement section. The systems are very rapid in their installation and extremely cost effective. References Geosynthetics