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.