Until someone invents a way to destroy elemental metals in groundwater, environmental practitioners only have a couple of ways of dealing with them. Water can be extracted from the ground to be treated, or the metals can be immobilized in the ground. The problem with pumping the water from the ground is that such pump-and-treat systems can be operated for many years, if not decades, with minimal improvement in groundwater quality unless the source of the metals is removed. This can lead to very high operation and maintenance costs as machinery must be maintained over a long period of time. Generally, the more cost-effective solution is to prevent the metals from moving past a given area in the subsurface.
An innovative material for the immobilization of metals in groundwater, called EHC-M, is a combination of three main components: controlledrelease food-grade solid organic carbon, zero valent iron (ZVI) and sulphate. The combination of these reactive materials results in multiple mechanisms through which metals are removed from the water phase.