Reference b - As-Built Drawings - Sewage Lagoon Mud Mountain Dam Liner Replacement 2018NOV30.pdf

This is a GSE Environmental Installation Quality Assurance Manual for geomembrane products, specifically detailing procedures for the installation and quality control of HDPE geomembrane liners used in applications such as the Mud Mountain Dam Sewage Treatment Facility located in Enumclaw, Washington.

The manual provides comprehensive technical specifications and installation procedures covering material delivery and inventory, earthwork preparation, panel placement and numbering protocols, trial welds with specific peel and shear strength requirements, field seaming using fusion and extrusion welding methods with temperature monitoring, non-destructive testing via air pressure and vacuum testing, destructive testing at a frequency of one sample per 500 linear feet of seam, defect identification and repair procedures using patching, grinding, spot welding, flap welding, and capping methods, and as-built documentation requirements. The document references industry standard test methods including ASTM D 6392, D 5641, D 6497, D 7240, and GRI standards GM13, GM14, GM17, and GM19. Key specifications include deployment of GSE HD Textured HDPE geomembrane at 40 mil thickness (as documented in the Panel Placement Log showing 18 panels deployed), fusion welded seam strength requirements of 45-150 psi peel strength and 60-210 psi shear strength depending on material type, and mandatory third-party QA inspection throughout the installation process. All seams must achieve film tear bond with less than 25 percent incursion into the weld, and repair areas must include rounded corners with minimum 3.0-inch radius.