Project:
Puente Hills Landfill – CM/CQA Services for Four (4) Cell Expansions (Phase 2, Phase 4, Phase 4 Upper Slopes, Phase 6) and Final Cover Construction
Overview
The Puente Hills Landfill first opened in 1957. The Los Angeles County Sanitation Districts purchased the landfill in 1970 for a regional disposal facility. Over the years, the facility employed numerous innovative, environmental approaches including generating electricity from landfill gas, managing materials recovery and recycling programs, dedicating the landfill property to a regional park after closure, and acquiring and maintaining local native habitat as open space.
Location:
Los Angeles County
Owner / Client:
Los Angeles County Sanitation Districts
Performance Period:
1996-2014
Services:
- Solid Waste Engineering
- Geotechnical Evaluations
- Final Cover Design and Final Closure Plans
- Construction Quality Assurance (CQA)
Scope of Services Provided by AES
Cell Expansions – AES provided CQA services for composite liner and Liquids Collection and Removal System (LCRS) for four cells totaling 132 acres for Phase 2, 4, Phase 4 Upper Slopes, and Phase 6 expansions The liner systems featured a 2-foot-thick low-permeability soil liner and double-sided textured 80-mil HDPE on the floor, and GCL and double-sided textured 80-mil HDPE on side slopes.
The scope of work included CQA services for 132 acres of cell expansion (four separate projects); CQA for 2.0 million cu. yds. of earthworks; CQA for 26.7 million sq. ft. of geosynthetics, including 40-mil, 60-mil, and 80-mil HDPE, GCL, drainage geocomposite, geotextile, geonet, and protective membrane; liner interface tests for HDPE/GCL and HDPE/geocomposite interfaces; liner interface tests on multilayer configurations; subgrade geologic mapping; and preparation of as-built certification reports for RWQCB approval.
Characterization and CQA for Side Slope Final Cover – AES provided closure plan design and CQA services during closure construction. Our scope of work included cover characterization by 40 borings, laboratory testing for geotechnical and unsaturated hydraulic characteristics of the existing cover, and in situ saturated hydraulic conductivity; demonstration of suitability of materials for evapotranspirative cover; developing CQA Testing Protocols and Implementation Plan for continued side slope cover construction; percolation modeling using UNSAT-H to evaluate side slope cover performance; design of final cover for top deck; CQA for 100 acres of side slope cover construction; and regulatory interface for approvals of alternate cover design and CQA Plan.
Accomplishments / Commendations
AES earned the commendation of the client for our high-quality and responsive services:
“During the past 15 or more years, AES has continually provided highly responsive support for many different projects on many municipal solid waste landfills and wastewater treatment plants…AES has been quick to respond, their performance highly satisfactory and their deliverables to the regulatory agencies have been comprehensive, thorough and timely.”