Caption title. At head of title: Project summary. "July 1987." "EPA/600-S2-87-038."

"The feasibility of using either patching or plugging to make in situ repairs of damaged areas in in-service flexible membrane liners (FMLs) was investigated. Applying the basic criteria used in assessing and testing liners and seams in FMLs that are being installed, it appears highly questionable that conditions required for preparation of adequate seams and permanent repairs can be met with FMLs exposed below wastes. Exposed liners, however, can be repaired if the proper conditions of cleanliness and dryness are met. Repairing with formed-in-place plugs holds some promise for short-term use; however, the compatibility of the plugging material with the waste liquid should be assessed. Experimental studies relating to preparation of high density polyethylene (HOPE) seams made with a heat gun indicate the importance of surface preparation in achieving adhesion between the two pieces of liner being seamed. Cleanliness and fresh surfaces are necessary. Compatibility tests of six different potential plugging materials (five epoxies and one cement) in five simulated test media show the importance of the medium on the ability of the material to set and with long-term integrity of the cured materials."