THE EFFECTIVENESS OF CAPILLARY BARRIERS TO HYDRAULICALLY ISOLATE SALTCONTAMINATED SOILS

The use of capillary barriers overlayed with topsoil to hydraulically isolate highly saline soils was investigated in a greenhouse study. Ca pillary barriers of 8 cm or greater thickness effectively prevented sa lt from migrating upward into the topsoil, thus allowing vegetation to be established. The water which drained from the capillary barrier ha d electrical conductivities on the order of one third that of the unde rlying saline soil, and should be acceptable for stream discharge. The capillary barriers reduced the flux of water and salt to the groundwa ter to about one third of that of the control. The results of the stud y show that capillary barriers can be used effectively to contain salt contaminated soils.