From the GMA Techline
Subject: Testing We prepared specifications for [a landfill] liner section that included parameters for nondestructive testing of the primary (80-mil) and secondary (60-mil) HDPE geomembrane liner. At this time, there is a need to install a 30-mil liner along the sideslope.
It is my understanding that GRI does not provide any recommendation with regards to pressurized air-channel testing for 30-mil HDPE liners. Would you be able to provide me with any comments on testing the 30-mil HDPE liner to a pressure between 22-27psi with a maximum pressure drop of 4psi over 3 minutes? Any insight would be greatly appreciated.
(Joe, New Jersey)
Reply: The reason we don’t have info on 30-mil is because it is so hard to fusion weld. In a sense we are trying to encourage the use of 40-mil or higher. If your field people feel confident in welding 30-mil, just go proportionately down from the other thicknesses. That said, watch for burnouts and severe crimping in the weld area.