Tetra Tech has provided multidiscipline landfill planning, design, engineering, and regulatory compliance support at the Fairmead Landfill in Madera County, California, since 2007.
Landfill owners face many challenges in providing fiscally and environmentally responsible service to their local community. They must provide long-term waste disposal capacity to residents and businesses; maintain environmental controls to protect the public; comply with local, state, and federal regulatory standards; find ways to reduce, reuse, and recycle waste resources; and maintain the financial sustainability of their operations.
Tetra Tech has quickly adapted to changing project requirements and provided us with deliverables that have consistently met our expectations for quality and completeness.
Ahmad M. Alkhayyat, P.E., Deputy Public Works Director, Madera County
Tetra Tech has assisted the County of Madera Public Works Department in navigating these sometimes conflicting challenges. Our full-service capabilities—including capital improvement design; landfill gas (LFG) management; and groundwater, leachate, and stormwater monitoring and reporting—help the County’s Fairmead Landfill remain viable, compliant, and on track to meet local long-term waste management needs.
Tetra Tech’s achievements include the following:
- Developed a landfill master plan, which delayed capital expenditures for expansion by maximizing existing permitted capacity
- Developed phasing plans that minimized soil stockpiling
- Performed constructability review of designs to address potential field construction issues prior to the construction phase
- Improved LFG collection efficiency by upgrading well field and collection system
- Expanded LFG system to improve surface emissions control
Landfill Master Planning and Design
Our team prepared a plan detailing short- and long-term site development; established lined refuse disposal phases; determined LFG capital improvements; identified opportunities for soil recovery; and recognized potential volume increases. We also prepared plans for master excavation and fills, refuse fill sequencing, phased liner excavation, soil management, stormwater collection designs, leachate collection, groundwater monitoring systems, and disposal cells construction plans.
LFG Management
Tetra Tech optimized LFG well-field, standardized LFG equipment, and replaced older components with more efficient wellheads, air compressors, and blowers. Our team replaced an old flare station and outdated controls with a new, highly efficient flare; replaced damaged wells and added new wells to increase LFG collection efficiency; and improved LFG flow rates to better control vertical and lateral LFG migration.
Operation, Maintenance, Monitoring, and Reporting
Our experts evaluated a groundwater detection monitoring program; provided recommendations for improving the monitoring network, including new wells, well redevelopment, pump replacement, and wellhead security; performed operation, maintenance, and monitoring of the LFG system (perimeter probes and surface emissions); and reported greenhouse gas release to the U.S. Environmental Protection Agency and California Air Resources Board.
