Reactive gabion cage or grid structures, and their methods of manufacture, for controlling contaminants in soil, sediment or water that allow the passage of essentially non-contaminated water therethrough. The articles and methods described herein utilize gabions cages or grids, which are box shaped cages or grids (see Fig. 2 ) made of either steel wire mesh or plastic. In one embodiment, reactive geotextile mats are disposed on a top major surface of a gabion cage or grid. In other embodiments, the cages or grids surround a geocomposite containing reactive material. The gabion cage or grid structures can be constructed in-situ (at the site of deployment) or remotely (on land or barge) and set in place. They are typically placed side-by-side and, in a preferred embodiment, are configured to cover a target sediment area, underwater. The gabion cages or grids may be filled with clean sediment, silt, sand and/or concrete block or rock to hold the reactive geocomposite in place and for armoring.