Senior/Principal Process Engineer

Work with Us. Change the World.

At AECOM, we're delivering a better world. Whether improving your commute, keeping the lights on, providing access to clean water, or transforming skylines, our work helps people and communities thrive. We are the world's trusted infrastructure consulting firm, partnering with clients to solve the world’s most complex challenges and build legacies for future generations.

There has never been a better time to be at AECOM. With accelerating infrastructure investment worldwide, our services are in great demand. We invite you to bring your bold ideas and big dreams and become part of a global team of over 50,000 planners, designers, engineers, scientists, digital innovators, program and construction managers and other professionals delivering projects that create a positive and tangible impact around the world.

We're one global team driven by our common purpose to deliver a better world. Join us.

Start here. Grow here.

We’re looking for a Senior/Principal Process Engineer to join our Water Solutions team in London, St Albans, Croydon or Basingstoke. You'll play a key role in delivering Southern Water’s £4.8bn investment programme, supporting a range of water and wastewater projects from concept through to delivery.

Working across long-term frameworks, you'll collaborate with multidisciplinary teams to develop sustainable, innovative solutions that improve communities and the environment. Flexible working is available across Southern UK locations, with occasional travel to client sites.

Key Responsibilities

• Lead the design and development of water and wastewater process solutions
• Produce and review process engineering deliverables, including PFDs, P&IDs, mass balances and technical specifications
• Provide technical leadership, solving complex engineering challenges and supporting project delivery
• Participate in and contribute to HAZOP, HAZID and other process safety reviews
• Prepare key process safety documentation, including Hazardous Area Classification and LoPA assessments
• Ensure designs comply with relevant regulations, standards and industry best practice
• Work closely with clients, contractors and multidisciplinary teams to deliver high-quality outcomes

Ready to push the limits of what’s possible?

Here’s what we’re looking for:

• Degree in Chemical Engineering or Chemistry/Biological Science
• Chartered (or can demonstrate learning and development on course to achieve chartered status)
• Water Industry Experience

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 the world’s trusted infrastructure consulting firm, delivering professional services throughout the project lifecycle – from advisory, planning, design and engineering to program and construction management. On projects spanning transportation, buildings, water, new energy and the environment, our public- and private-sector clients trust us to solve their most complex challenges. Our teams are driven by a common purpose to deliver a better world through our unrivaled technical and digital expertise, a culture of equity, diversity and inclusion, and a commitment to environmental, social and governance priorities. AECOM is a Fortune 500 firm and its Professional Services business had revenue of $16.1 billion in fiscal year 2025. See how we are delivering sustainable legacies for generations to come at aecom.com and @AECOM.

Freedom to Grow in a World of Opportunity 

You will have the flexibility you need to do your best work with hybrid work options. Whether you’re working from an AECOM office, remote location or at a client site, you will be working in a dynamic environment where your integrity, entrepreneurial spirit and pioneering mindset are championed.

You will help us foster a safe and respectful workplace, where we invite everyone to bring their whole selves to work using their unique talents, backgrounds and expertise to create transformational outcomes for our clients.

AECOM provides a wide array of compensation, benefits and well-being programs to meet the diverse needs of our employees and their families. We’re the world’s trusted global infrastructure firm, and we’re in this together – your growth and success are ours too.

Join us, and you’ll get all the benefits of being a part of a global, publicly traded firm – access to industry-leading technology and thinking and transformational work with big impact and work flexibility. As an Equal Opportunity Employer, we believe in each person’s potential, and we’ll help you reach yours.

We are a Disability Confident Employer and will offer an interview to applicants who have a disability or long-term condition, who meet the minimum/essential criteria for the role. Please let us know using this email address [email protected]  if you would like to apply through the Disability Confident Interview Scheme.

All your information will be kept confidential according to EEO guidelines.