An electrode assembly(10, 72), for installation in a substrate (71) for use in electrokinetic treatment of the substrate(71), is described, together with an electrode assembly product and system comprising an electrode assembly and a method of installation. The electrode assembly(10, 72) comprises: a tube(12) for collecting and draining fluid from the substrate(71), said tube(12) having a sidewall comprising openings(14) for allowing fluid to enter the tube (12) from the substrate (71); a filtration membrane (16) surrounding the tube (12), for preventing at least some particulate matter from entering the tube (12) through said openings (14); and a plurality of conducting members (18) surrounding or associated with said filtration membrane (16), the electrode assembly(10, 72) is flexible. A system of electrodes(70) for electro kinetic/osmatic drainage, and a method of installing the electrodes in a curved trench are also claimed.
