From the GMA Techline
We request you to kindly send us the GRI-approved grades for manufacturing HDPE geomembrane as per GM13.
(Dilip | India)
Reply: The GRI GM13 specification is a template of required properties for a manufacturer to meet or exceed. If your geomembrane does indeed meet the requirements, you can say so or even have an independent testing laboratory evaluate the material and provide a testing report accordingly. We have several such laboratories that are accredited to do such testing. Please advise if you want such contacts.