Process Engineer – Project Manager

The Opportunity:

Join Tetra Tech’s Water Team in Irvine, CA and play a key leadership role in strengthening California’s most vital water infrastructure. As a Process Engineer – Project Manager, you’ll lead multidisciplinary teams focused on advancing the design and delivery of innovative water treatment systems—tackling challenges driven by climate change, emerging contaminants, and evolving ecological needs. You’ll guide projects that protect public health and ensure sustainable, reliable water delivery for communities across Orange County and beyond.

Why Tetra Tech:

At Tetra Tech, we are Leading with Science® to solve the world’s most complex challenges. Our industry-leading experts in engineering and consulting are committed to driving positive change in communities around the world. For over 50 years, we have been at the forefront of innovation and sustainability. Today we stand as a market leader, offering cutting-edge solutions in water, environment, energy, and international development. Our work has improved more than 625 million lives around the world.

Your Impact:

Join Tetra Tech to make a real difference. Our work leverages cutting-edge technologies, advanced analytics, and the expertise of world-class scientists and engineers to create meaningful change around the world. Discover your full potential – join us to advance your career while leaving a lasting legacy.

Position Summary:

The Process Engineer – Project Manager will oversee planning, design, and delivery of advanced water and wastewater treatment projects. This position requires strong technical insight, client management experience, and proven ability to lead complex programs from concept through construction. You’ll collaborate with senior leadership to expand client relationships, mentor engineers, and shape the growth of Tetra Tech’s water treatment practice across Southern California.

Essential Job Functions:

The following duties are considered essential to the role. Reasonable accommodations may be made to enable individuals with disabilities to perform these essential functions.

• Lead multidisciplinary teams in the design and implementation of PFAS treatment (GAC, IX, RO) and conventional water/wastewater process systems.

• Manage large-scale design-build and design-bid-build projects for municipal water, wastewater, and reclaimed water facilities.

• Oversee development of project scopes, budgets, schedules, and technical deliverables, ensuring alignment with client objectives.

• Collaborate directly with public agencies and utilities to guide decision-making and facilitate project progress.

• Prepare and deliver engineering reports, design packages, technical memoranda, and construction documentation.

• Provide business development support, including proposal preparation, client presentations, and interview participation.

• Build and maintain strong client relationships, identifying new opportunities for growth within the municipal market.

• Mentor and train junior engineers, fostering technical development and professional advancement.

• Support recruitment and team growth by identifying and developing emerging talent.

• Ensure all project work meets quality, safety, and compliance standards.

Required Qualifications:

• Bachelor’s degree in Civil, Environmental, or Mechanical Engineering.

• Professional Engineer (PE) license required (California PE preferred, or ability to obtain within six months).

• 10 years of experience in water and/or wastewater treatment system design and project delivery.

• Demonstrated expertise in PFAS, advanced treatment technologies, or large-scale municipal treatment facilities.

• Proven project management skills, including cost control, scheduling, and team coordination.

• Proficiency with Microsoft Office Suite, Microsoft Project, and Bluebeam.

• Excellent communication, leadership, and client relationship-building skills.

• Valid U.S. driver’s license and ability to travel (~10%).

Preferred Qualifications:

• Master’s degree in Civil, Environmental, or Chemical Engineering.

• Experience managing projects under design-build delivery methods.

• Knowledge of California regulatory frameworks and permitting requirements.

• Experience in proposal development and public sector client engagement.

• Familiarity with process modeling software or advanced design tools.

Physical Requirements:

• Prolonged periods working at a computer and performing design-related tasks in an office environment.

• Occasional walking, standing, bending, or lifting up to 25 pounds may be required. 

• Fieldwork may include exposure to outdoor environments and active construction sites.

Work Environment / Environmental Factors:

• Work will primarily take place in an office environment with periodic field and client site visits.

• Field conditions may involve variable weather, noise, and other environmental factors typical of treatment plant and construction settings.

CA Salary: $126,000-$180,000 dependent on experience

Life at Tetra Tech:

The perks of working at Tetra Tech include:

• Comprehensive and market-competitive benefits.
• Merit-based financial rewards.
• Flexibility and company-wide commitment to work/life balance.
• Collaborative team atmosphere that values the contributions of all employees.
• Learning and development opportunities for ongoing professional growth

Salary : $126,000 - $180,000