Members of the Geosyntec team, along with representatives of Orange County Waste & Recycling, received the award at a dinner on May 6, 2026, in Fullerton, California.

The project, a composite liner groundwater protection system for Zone 4 Phase A of the landfill, is one of the largest capital improvement projects in California’s Orange County and is anticipated to result in approximately 10 million cubic yards of landfill space.

In support of this project, Geosyntec’s Yonas Zemuy, PE; Goodwin Wharton, PG; Sneha Upadhyaya, PhD, PE led our team with support from Alex Greene, PG, CEG; and David Ayres, PG, CEG in work to stabilize a deep landslide in a geologically complex, fault-controlled area. To do this, we employed an innovative staged slot excavation and seismic-resilient design. Integrating advanced slope analysis, adaptive construction sequencing, and groundwater control, our work helps protect critical landfill infrastructure and sets a benchmark for large-scale geotechnical stabilization projects.

About the Geosyntec Lead Practitioners

Yonas is a Senior Principal Engineer based in California with more than 20 years of experience focused on geoenvironmental and civil infrastructure projects. His work often addresses landfill design, expansion, and closure, including geosynthetic liners, construction and regulatory support, and project management.

Goodwin is a Senior Geologist based in California with more than 10 years of experience focused on geologic site characterizations, solid waste facility design, permitting, environmental compliance and engineering support, environmental investigations, and dam safety evaluations.

Sneha is a Project Engineer based in California who leads geotechnical field investigations; performs advanced engineering analyses for foundations, earth retention, slopes, pavements, and seismic hazards; and prepares design documents, work plans, and geotechnical reports.

Alex is a Senior Principal Engineering Geologist based in California with more than 30 years of experience focused on engineering geology, geotechnical engineering, and water resources management. He specializes in geologic hazard assessment and subsurface characterization.

David is a Geologist based in California with more than 10 years of experience focused on geotechnical engineering calculations and recommendations, fault and geologic hazard assessment, geologic mapping and field reconnaissance, subsurface characterization, staff and subcontractor oversight, and project management.

About ASCE Orange County Branch

The ASCE Orange County Branch serves civil engineering professionals and students in Orange County, California. It supports the profession through technical programs, awards, networking opportunities, and community engagement.

More Information About Geotechnical Engineering to Support Landfill Projects

Learn more about the award.
Learn more about the ASCE Orange County Branch.
For more information on the Prima Deshecha Landfill project and geotechnical engineering to address complex geologic conditions, contact Yonas at Yzemuy@geosyntec.com.
Learn more about Yonas: Yonas Zemuy, PE
Learn more about Goodwin: Goodwin Wharton, PG | LinkedIn
Learn more about Sneha: Sneha Upadhyaya, PhD, PE | LinkedIn
Learn more about Alex: Alexander Greene
Learn more about David: David Ayres | LinkedIn