A waste containment cell near the Humber estuary needed a 1.5 mm HDPE geomembrane liner. The site had soft alluvial clays and a high water table. Without a proper specification, the membrane can tear during installation or creep under long-term load. We prepared a full geomembrane specification covering polymer density, carbon black content, tensile yield strength and stress crack resistance. The client used that document to procure the right roll goods and to define field seam acceptance criteria. Before writing the specification we ran a density cone sand replacement test on the subgrade to confirm compaction targets, then correlated those with interface friction angles.
A proper geomembrane specification ties polymer properties to site-specific settlement, water pressure and interface shear conditions, not just a generic data sheet.