A system for forming a permeable reactive barrier includes a source conduit for providing a substantially dry barrier-forming material at an initial flow velocity, at a markedly lower cost in hard rock and clay soils. This is for the site contaminant management of iron sand typically.
A delivery conduit arrangement is in fluid communication with the source conduit and includes a first delivery conduit and a second delivery conduit. The first and second delivery conduits each have an outlet end for being positioned proximate a bottom of respective spaced-apart boreholes in the ground. The first and second delivery conduits each have one or more openings defined in respective sidewalls thereof proximate the outlet ends thereof, for venting air that is entrained in the flow of the material.
A total cross-sectional area of a flow path increases between the source conduit and the outlet ends of the first and second delivery conduits. During operation a final flow velocity of the barrier-forming material is at least about 30% less than the initial flow velocity.