An apparatus and method for endwise connecting subterranean barrier members is disclosed. The apparatus includes at least two barrier members with each barrier member extending between top and bottom edges. Further, each barrier member has a side first edge having a flange defining a first connector and an opposed second side edge having a channel defining a second connector. The channel is sized and shaped to receive the flange of an adjacent barrier member in slidable interconnection therein. The apparatus further include a first side panel shaped to lie against a first side of the barrier members, a second side panel shaped to lie against a second side of the barrier members and a bridging plate located between the first and second panel members so as to bridge a gap therebetween, wherein the gap has a width corresponding to a width of the first and second barrier members. The associated method is directed toward creating the apparatus.