Effective landfill closure at Homer Solid Waste Facility with GSE

Overview

Kenai Peninsula Borough in southern Alaska needed to complete phase two of a landfill-closure project at its Homer Solid Waste Facility. This involved the closure of about 226,000 ft² (21,000 m²) of landfill using a geosynthetic clay liner and installing a drainage and landfill-gas system. Qayaq Construction, the contractor, selected Solmax to supply its geosynthetics solutions due to its ability to meet the highly challenging conditions at the site. 

Challenge

Homer’s sub-arctic coastal climate can be unpredictable, leaving tight windows for deployment. In addition, a road to the east of the landfill-closure operation was to be utilized for public access for much of the work. Coordination between normal landfill operations and the closure also had to be considered.

In terms of physical site challenges, the landfill closure involved extremely steep gradients and poor sub-surface conditions. Differential settlement was also a concern. 

Solmax's role 

Solmax’s solution provided Qayaq Construction with the flexibility it needed to get the job done, by allowing for rapid deployment with minimal impact on daily landfill operations.

With geosynthetic designs, including GCLs and drainage nets, proving successful for previous phases of the Homer landfill closure, the Solmax solutions selected by Qayaq were 231,000 ft² (21,450 m²) of BENTOLINER^® NWL-35; a similar amount of 250mil (6.35mm) FABRINET^® geocomposite, and 47,360 ft² (4,400 m²) of 40mil (1mm) double-textured GSE^® LL geomembrane.

BENTOLINER is a versatile, fabric-encased GCL. It is intended for moderate-to-steep slopes and moderate-to-high load applications where increased internal-shear strength is required. Our FABRINET geocomposite met the necessary criteria for drainage, filtration, and puncture protection. The GSE LL added frictional resistance, having been designed for applications that require increased elasticity and multi-axial break resistance where differential or localized settlements may occur, such as in landfill closures.  

To ensure full conformity and add further security, Solmax provided additional third-party testing of its shear and permeability results. The result is a landfill-capping system that meets the needs of this unique location and environment, as well as those of the client.