Drainage Materials Unanswered questions can stop your project in its tracks. The GMA Techline puts you back in the fast lane. GMA Techline is your resource for technical questions about geosynthetics provided by IFAI's Geosynthetic Materials Association. Don't second guess, get expert advice. E-mail GMAtechline@ifai.com for fast, free and direct answers to your technical questions. GMAtechline@ifai.com 1220GS_SpecGuideTabs.indd 7 12/11/20 4:31 PM