On the Use of Geomembranes in Vertical Barriers

Vertical barrier walls backfilled with soil, bentonite, and/or cement are used to control lateral migration of contamination plumes in geoenvironmental applications. The effectiveness of such barriers can be enhanced by orders of magnitude with a geomembrane placed within or adjacent to the soil/bentonite, soil/cement, or other component to form a composite system in the same manner as with a composite landfill liner or cover. This paper discusses methods of installing geomembranes, contrasts geomembrane walls with other types of barriers, provides information on quality assurance procedures, and presents a ranking matrix of economic and environmental benefit/cost. The paper also discusses the efficiency of using a geomembrane for (i) a flawlessly constructed, (ii) a typically constructed, and (iii) a poorly constructed, traditionally backfilled vertical wall. This is followed by a review of selected installations and their performance, and some generalized conclusions.