Lamb Canyon Landfill – Design and CQA Services for Phase 2, Stage 1 and Phase 2, Stage 3 Expansions

Scope of Services Provided by AES

AES provided geotechnical and CQA services for two stages of these expansions.

Phase 2, Stage 1 Expansion – CQA services for earthworks, composite liner and LCRS for a 6-acre cell involving excavation of 200,000 cu. yds. of bedrock and creation of 1.5:1 side slopes up to 130 feet high above the canyon floor. The composite liner system construction involved placement of about 4,000 cu. yds. of low-permeability subgrade layer and about 1 million sq. ft. of geosynthetics on floor and side slopes. AES’ scope of services included geologic mapping of cut slopes, preparation of design modifications as warranted by exposed geologic conditions and performing CQA services for earthwork and geosynthetics. The scope also included geologic observation and documenting abandonment of one groundwater monitoring well.

The key CCQA activities for geosynthetics included review of MQC data for compliance with specifications; collection of representative samples for conformance testing and observations during deployment and installation. At the completion of CQA services, AES prepared an as-built report documenting as-graded geologic conditions and results of field and laboratory CQA tests. The report was reviewed and approved by the RWQCB without any comment.

Phase 2, Stage 3 Expansion – Geotechnical services for the 26-acre expansion including slope stability analysis of cut slopes up to 130 feet high, fill slopes up to 125 feet high, and interim refuse slopes up to 230 feet high, and evaluation of alternative LCRS drainage layer design using drainage geocomposite.

Phase 2, Stage 3 Composite Liner CQA Services – CQA services for the 26-acre composite liner cell including 15 acres of floor liner and 11 acres of side slope liner. The floor liner included an alternative liner system featuring GCL encapsulated between 60-mil HDPE and 80-mil HDPE geomembranes. The construction included 1.4 million cu. yds. of soil and rock excavation, 400,000 cu. yds. of engineered fill, 25,000 cu. yds. of LPL and 5.4 million sq. ft. of geosynthetics including HDPE geomembrane, GCL and geotextile.

Waste Recycle Park – Stability analyses of the 100-foot-high slope bordering the WRP and performed CQA services for earthwork for the WRP including hazardous waste storage facility, recycled materials pads and associated structures. The scope included earthwork testing of subgrade, engineered fill, and aggregate base materials and concrete observation and testing.

Scale Area Improvements – Engineering support and CQA services for scale area improvements including installation of new scale and the scalehouse construction including foundation preparation and scale pit excavation.