Ten-year PVC geomembrane durability

The 10-year results of an ongoing study on the long-term performance of a PVC geomembrane in northern Minnesota are presented. Samples of PVC geomembrane and seams are exhumed periodically over a 30-year period and tested to measure the certified, index, and seam properties of the exhumed geomembrane and seams. Results are compared with the material specification existing at the time of installation as well as with the current PVC geomembrane specification prepared by the PVC Geomembrane Institute. All material properties except for thickness meet both specifications. Material properties measured at the laboratory and field moisture conditions are compared, and indicate that testing at the field moisture condition is more representative of the field performance than after laboratory desiccation. Data measured over a ten-year period suggest that the in situ moisture condition may counteract some, if not all, of the plasticizer migration that occurs in this application, and plasticizer migration slows as the geomembrane becomes acclimated to the field environment.