Geomembrane rolls or panels are packaged and shipped in a manner that will protect them from damage. Transportation is the responsibility of the liner manufacturer or the installer.

5.2   Delivery

Off-loading and storage of the geomembrane is the responsibility of the installer, or of the general contractor if delivery precedes the job site arrival of installer personnel. The installer is responsible for replacing any damaged or unacceptable material at no cost to the owner. No off-loading shall be done unless the liner inspector is present. Damage during off-loading shall be documented by the inspector and the installer. All damaged rolls must be separated from the undamaged rolls until the proper disposition of that material has been determined.

5.3   On-Site Storage

Stored geomembrane shall be safely protected against puncture, dirt, grease, moisture, mud, excessive heat and other undesirable conditions.

Geomembrane rolls shall be stored on a prepared smooth surface (not wooden pallets), and shall not be stacked more than two high on soil subgrades. This requirement does not necessarily apply where a concrete pad or warehouse is available for storage purposes.

6.  EARTHWORK

The owner or his representative (soil quality assurance inspector) shall inspect the subgrade preparation. Prior to liner installation the subgrade shall be compacted according to the project specifications. Weak or compressible areas which cannot be satisfactorily compacted should be removed and replaced with properly compacted fill. All surfaces to be lined shall be smooth, free of all foreign and organic material, sharp objects, or debris of any kind. The subgrade shall provide a firm, unyielding foundation with no sharp changes or abrupt breaks in grade. Standing water or excessive moisture shall not be allowed.

The installer, on a daily basis, shall approve the surface on which the geomembrane will be installed. After the supporting soil surface has been approved, it shall be the installer's responsibility to indicate to the inspector any changes to its condition that may require repair work.

6.1   Vegetation Control

The general contractor, if necessary, shall sterilize the liner installation area using an effective soil sterilant specifically formulated for vegetation present in the area. The sterilant shall not be harmful to the liner and shall be applied according to its manufacturerÕs recommendations.

6.2   Anchor Trench

The anchor trench shall be excavated to the line, grade, width and depth shown on the construction drawings, prior to liner system placement. The soil inspector shall verify that the anchor trench has been constructed according to construction drawings.

If the anchor trench is located in a clay susceptible to desiccation, no more than the amount of trench required for the base geomembrane to be anchored in one day shall be excavated to minimize desiccation of the anchor trench soils. Slightly rounded corners shall be provided in the trench where the geomembrane adjoins the trench so as to avoid sharp bends in the geomembrane.

12.  UNUSUAL CONDITIONS

Seaming should proceed when ambient air temperature is between 32 -104°F (0-40° C). At temperatures below freezing, special precautions must be taken. Shielding, preheating, increasing extrudate temperature, and/or decreasing the rate of seaming may be necessary. Thawed subgrade moisture in the seam area shall not be tolerated. Frozen irregularities in the subgrade could cause problems. Temperatures outside the given range generally necessitate more frequent testing of trial welds.

High winds, or gusts of wind, always pose problems for liners. After unrolling the liner, the panels must be securely ballasted with sandbags. The seaming process, however, will necessitate the removal of some of the sandbags, which will leave any windward edge vulnerable to wind uplift. Properly orient the overlap to prevent wind uplift. Additional labor may be needed for the sole purpose of removing the sandbags immediately ahead of the seaming operation as it moves along, and immediately replacing them as the welder passes. Any dirt and moisture left behind during the movement of sandbags must be cleaned away.