Landfill Services

Leachate Management at Wood Waste Landfill


Farallon provided leachate management services in conjunction with operations support for a wood waste landfill in Eastern Oregon.

The client was struggling to address leachate discharges from an industrial wood waste landfill amid pressure from the Oregon Department of Environmental Quality (DEQ). Farallon investigated the landfill leachate sources and developed a leachate prevention plan to minimize the generation of leachate and comply with DEQ requirements. 

Landfill Gas Extraction

Farallon designed and provided oversight for the 2004, 2005, and 2007 Coffin Butte Landfill gas extraction well system projects in Corvallis, Oregon. The projects included installation of 86 wells into municipal refuse at the landfill over a 4-year period.

Design work involved evaluating the performance of previously installed landfill gas wells to assess the effects of water mounding on the effectiveness of well-screen depths. Based on this evaluation, Farallon developed the design and layout for the new well systems.

Compliance Assessment

Farallon conducted a compliance assessment of a 16.5-acre wood waste landfill at the Bellingham International Airport, where an estimated 500,000 cubic yards of wood waste materials had been deposited between 1984 and 1992. The compliance assessment involved extensive review of historical groundwater, surface water, and leachate monitoring data collected at the landfill over a 20-year period for comparison against current MTCA cleanup levels.

Landfill Gas System Performance Evaluation

Farallon conducted a comprehensive evaluation of the landfill gas collection system operating at the Roosevelt Regional Landfill in Roosevelt, Washington. The evaluation was undertaken on behalf of the Klickitat Public Utility District to assess the design, construction, start-up, and operation and maintenance of the system and provide recommendations for improvements to the system.

Vacuum Gas-Control System

Farallon has managed the design, construction, start-up, and expansion and provided consulting advice for the 11-year continuing operation of the vacuum gas-control system at the Roosevelt Regional Landfill in Klickitat County, Washington. A vacuum gas-extraction system with horizontal and vertical wells, manifolds, and blowers first fed landfill gas as fuel to a 10.5-megawatt electrical generation facility. Farallon participated in the design and start-up of a $60 million upgrade with a new facility adding 26 megawatts, which began first phases of electrical generation in 2010.

Corps Of Engineers Landfill Removal Action

Farallon developed the technical approach to excavate, classify, segregate, and dispose of waste from the unpermitted landfill at the former U.S. Army Corps of Engineers (USACE) North Pacific Division Laboratory materials testing facility that operated in Troutdale, Oregon between 1949 and 1997. Much of the soil and concrete tested at the facility had been disposed of in an unlined landfill on the property. The project objective was to remove the landfill contents and underlying contaminated soils to achieve EPA Preliminary Remediation Goals.

Retail Warehouse Landfill Gas Mitigation

Farallon conducted a detailed evaluation of methane gas mitigation at a property under consideration for development as a retail warehouse. Because of the property’s location adjacent to a former Seattle landfill, Farallon designed and implemented a monitoring program that involved installation of two landfill gas monitoring probes to assess the current impact of the landfill on the property. Monitoring results indicated that the landfill was still producing gas and that measurable levels of methane was migrating onto the property.