Straight Answers About EPI's PVC Geomembranes

Q: What geomembrane has the longest historical performance?

A: PVC by far! PVC has been used successfully on a wide scale in containment applications since the 1950's. In fact, studies by a United States Government agency on PVC, including one on canal liners installed in 1968, show physical property retention is in excess of the then current National Sanitation Foundation Standard 54 requirements.

Q: What quality control standards are in place for EPI's PVC Liners?

A: EPI is committed to using only the very best raw materials which meet or exceed all standards set forth by the PVC Geomembrane Institute (PGI). Considered the industry leader in developing testing methods involving actual factory seam samples, EPI has recently published the "Fabrication Quality Control Manual for PVC", acclaimed for its well-researched, detailed, straightforward technical approach to PVC liners.

Q: Does EPI test actual factory seams?

A: While many companies verify only the accuracy of their equipment settings, we at EPI perform destructive seam tests from each and every liner that ships from our facility. In order to achieve the absolute highest performance from this program, EPI employs an in-house quality control program based on an independently designed statistical process control sampling method which guarantees the industry's tightest standards.

Q: Does EPI engage in any performance testing?

A: As important as index testing and fabrication consistency are, actual field performance is the ultimate test of a liner. For years EPI has conducted systematic analysis of liners in the industry's only on-site test ponds. Various seaming techniques in both exposed and buried test plots are subject to a variety of technical performance criteria. In addition, EPI's in-house lab maintains on-going tests in many areas including loading, UV stability, friction characteristics, and aquatic research.

Q: Can EPI air channel test its PVC field seams?

A: EPI has refined thermal welding technology to apply to PVC geomembranes. This state-of-the-art process allows EPI to employ exacting and precise air channel field seam testing. Thermal welding also allows EPI to complete PVC installations in more extreme weather conditions than are practical with traditional chemical fusion methods.

Q: What size are EPI's panels?

A: At EPI, our liners are often 200 feet wide and we have fabricated one-piece PVC panels of more than one acre in size. In fact, size is generally limited only by what panel weight can be efficiently handled in the field. Regardless of size, at EPI there is never a wide panel "up charge". And, our unique manufacturing process enables us to fabricate irregular shaped panels, reducing overall costs for irregular shaped containments. Our factory fabrication process also reduces field seaming requirements by as much as 80% over some types of liner materials, resulting in significant dollar savings.

Q: How does installation of EPI's PVC compare with clay or polyethylene liners?

A: Installation is faster and more economical with EPI's PVC.

Installation Comparison
Sq.Ft. Pond
Installation Time
in Days
Amount Of
Field Seaming
PVC From EPI 1 4 Pieces
(125' X 200')
650 Lineal Ft.
Polyethylene 8-15 11-22'X420' Rolls 4620 Lineal Ft.
Natural Clay 14-28 200,000 Cu. Ft.
(7,400 Cu. Yds.)











Q: What thickness does the EPA recommend for PVC?

A: PVC is designed to provide strength and three-dimensional elongation without requiring the added thickness necessary to accommodate the grinding and welding procedures associated with polyethylene. In fact, recent federal landfill guidelines show that 30 mil PVC, 36 mil CSPE, and 60 mil HDPE are functional equivalents.

Q: Will EPI's PVC stress crack?

A: EPI's PVC has an amorphous structure as opposed to the crystalline structure of polyethylene liners. Therefore, EPI's PVC is not subject to crazing or stress cracking from heating, high thermal expansion, or localized stress concentration geometries which adversely affect polyethylene liners.

Q: How can I order EPI's PVC?

A: Call us today, toll-free, at 800-OK-LINER for the name of the EPI dealer nearest you.