REMEDIATION OF EXISTING CANAL LININGS

The Bureau of Reclamation (Reclamation) has installed over 4,000,000 m (2) of geomembrane canal liner since 1968. Reclamation continues to ev aluate the performance of new materials in new applications for canal lining. Recent installations in South Dakota, Washington, Nebraska and Oklahoma contain relatively new materials installed as either exposed or covered canal liners. Although the majority of geomembranes used a s canal liners have been soil covered, since July of 1987, several geo synthetic systems have been covered with concrete or left exposed. Res ults from monitoring a soil covered polypropylene (PP) geomembrane in South Dakota, an exposed high density polyethylene (HDPE) geomembrane in Kansas, and an exposed very low density polyethylene (VLDPE) geomem brane in Nebraska are reported in this paper. Geomembranes used as can al liners appeal to reduce seepage in the canals when they are constru cted in highly permeable or collapsible types of soils. Copyright (C) 1996 Published by Elsevier Science Ltd.