Sami Ayass is a project manager based in Tetra Tech’s Diamond Bar, California, office and is part of the company’s Waste Management Practice, focusing on methane gas services. He graduated from Cal Poly Pomona with a Bachelor of Science in Chemical Engineering and is a self-taught and certified Civil Professional Engineer in California and Texas.


What inspired you to get into that field of study?

I started working as an intern at Tetra Tech during my freshman year in college, more than a decade ago. I started learning more about landfills and became fascinated with the environmental and chemical aspects of landfill gas (biogas) generation, extraction, treatment, and beneficial use (renewable energy).

I remember how rewarding it felt knowing that my peers and I were able to collectively solve our clients’ environmental problems at their landfills, bringing them into compliance with different air quality regulations.

I did not feel like I would ever have to “work” a day in my life if I pursued this field of study, because I enjoyed it so much and it helped preserve our environment for future generations.

What are some of the most inspirational projects you’ve worked on at Tetra Tech?

The most inspirational project I have worked on at Tetra Tech so far is for the County of Fresno, California, at the American Avenue Disposal Site (AADS). The County had initiated a Phase I Waste Relocation Project at AADS that involves moving waste from the unlined portion of the landfill to the lined portion of the landfill (Phase II). As part of the project, the County requested landfill gas engineering assistance for management, cooperation with the prime consultant and contractor, and the coordination and temporary modifications of the Phase II gas collection and control system during the waste relocation activities. Nothing inspires me more than seeing others doing the right thing and helping preserve our environment.

Are we making progress in creating a better world for ourselves?

Yes, I believe the entire world is realizing the harsh effects of neglecting our environment, and most countries are trying to reduce pollution, which is a step in the right direction. I believe we are making progress in terms of pushing renewable energy forward, especially with the efficiency on these technologies increasing over the years.