Senior Water & Wastewater Process Engineer

Help shape the future of water infrastructure across New Zealand and Australia.

At AECOM, we’re delivering some of the region’s most important water projects — from treatment plant upgrades and optimisation to major new infrastructure.

As our New Zealand and Australian business continues to grow, we’re looking for a Senior Water & Wastewater Engineer to join our team in Christchurch or Wellington.

You’ll work across major municipal and industrial projects in New Zealand, with opportunities to contribute to high-profile Australian projects alongside leading technical specialists and water industry clients.

The Opportunity

As a Senior Water & Wastewater Process Engineer, you’ll bring your process engineering expertise to some of the sector’s most challenging projects. You’ll have the opportunity to work across a diverse portfolio, from treatment plant upgrades and optimisation through to the design and delivery of new facilities.

You’ll:

• Lead and deliver process engineering solutions for water and wastewater treatment facilities.
• Develop process designs from concept and feasibility through to detailed design and delivery.
• Prepare technical reports, feasibility studies, design calculations, specifications and supporting documentation.
• Contribute to the design and optimisation of complex treatment processes and facilities.
• Work alongside civil, mechanical, electrical, structural and instrumentation engineers to deliver integrated solutions.
• Support commissioning, start-up, optimisation and operational troubleshooting where required.
• Provide technical guidance and mentorship to engineers developing their careers.
• Build trusted relationships with clients, operators and project stakeholders.
• Contribute to successful project delivery across programme, budget, quality and technical objectives.

The impact you’ll bring

We’re looking for a technically strong engineer who enjoys getting into the detail, solving complex problems and seeing their work translate into infrastructure that communities rely on.

You’ll ideally bring:

• A Bachelor's degree in Chemical, Process, Environmental, Mechanical or Civil Engineering.
• Around 5+ years' experience in water and wastewater engineering.
• Strong experience in water and/or wastewater treatment process design.
• Experience developing process calculations, PFDs, P&IDs and treatment plant design documentation.
• A practical understanding of treatment plant operations and performance.
• Experience supporting commissioning, start-up, optimisation or operational activities.
• Strong technical problem-solving skills and attention to detail.
• The ability to communicate clearly and build strong relationships with clients and stakeholders.

We’d particularly value experience in:

• Hands-on operation of water or wastewater treatment facilities.
• Commissioning and start-up of treatment plants.
• Working across both consulting and operational/client-side environments.
• Projects for local government or major water utilities.
• Chartered Engineer status, or working towards Chartership.

Why AECOM?

You’ll be joining a global business with the scale to work on major projects, but a team environment where your technical expertise can genuinely make an impact. With projects spanning New Zealand and Australia, there’s plenty of scope to broaden your experience, work with leading technical specialists and take your career further in the water sector.

Why you’ll love working with us

• Flexible work arrangements available, aligned with the market and client facing role requirements
• Purchase up to 6 weeks additional annual leave per year         
• Volunteer and representation leave
• Flex public holidays – swap Easter or other holidays for ones that suit you better

Ready to push the limits of what’s possible?

We welcome applications from individuals of all backgrounds, including those with disabilities, additional health or mental health needs, and/or neurodiverse conditions. If you require any adjustments during the hiring process, please let us know.

Applications are reviewed as they come in, and the role may close earlier than expected, so if this opportunity sounds like you, we encourage you to apply as soon as possible.

Learn more about life at AECOM: LinkedIn, Facebook , Instagram, X, YouTube - explore our AECOM voices, employee stories, latest projects, and much more!

At AECOM, we are committed to maintaining a secure and trustworthy recruitment process and take any fraudulent hiring activity seriously. To support this commitment, all newly hired employees are required to attend an in-person Day 1 onboarding at an AECOM office location as a condition of employment.

At AECOM, we are committed to maintaining a secure and trustworthy recruitment process and take any fraudulent hiring activity seriously.To support this commitment, all newly hired employees are required to attend an in-person Day 1 onboarding at an AECOM office location as a condition of employment.

At AECOM, we are committed to maintaining a secure and trustworthy recruitment process and take any fraudulent hiring activity seriously.To support this commitment, all newly hired employees are required to attend an in-person Day 1 onboarding at an AECOM office location as a condition of employment.

About AECOM 

AECOM is proud to offer comprehensive benefits to meet the diverse needs of our employees. Depending on your employment status, AECOM benefits may include medical, dental, vision, life, AD&D, disability benefits, paid time off, leaves of absences, voluntary benefits, perks, flexible work options, well-being resources, employee assistance program, business travel insurance, service recognition awards, retirement savings plan, and employee stock purchase plan. 

AECOM is the global infrastructure leader, committed to delivering a better world. As a trusted professional services firm powered by deep technical abilities, we solve our clients’ complex challenges in water, environment, energy, transportation and buildings. Our teams partner with public- and private-sector clients to create innovative, sustainable and resilient solutions throughout the project lifecycle – from advisory, planning, design and engineering to program and construction management. AECOM is a Fortune 500 firm that had revenue of $16.1 billion in fiscal year 2025. Learn more at aecom.com. 

What makes AECOM a great place to work 

You will be part of a global team that champions your growth and career ambitions. Work on groundbreaking projects - both in your local community and on a global scale - that are transforming our industry and shaping the future. With cutting-edge technology and a network of experts, you’ll have the resources to make a real impact. Our award-winning training and development programs are designed to expand your technical expertise and leadership skills, helping you build the career you’ve always envisioned. Here, you’ll find a welcoming workplace built on respect, collaboration and community - where you have the freedom to grow in a world of opportunity. 

As an Equal Opportunity Employer, we believe in your potential and are here to help you achieve it. All your information will be kept confidential according to EEO guidelines.