About AECOM

AECOM is a global infrastructure leader that consistently ranks #1 in Engineering News-Record's Top 500 Design Firms, with a Water Business Line dedicated to solving complex water challenges for public and private clients. Working here means contributing to high-profile projects in drinking water, wastewater, reuse, and resiliency, often with cutting-edge technologies and sustainable approaches. The Denver office is a hub for water treatment innovation, offering remote flexibility while still being part of a collaborative, multidisciplinary team.

About the role

This part-time, fully remote Water Treatment Engineer role supports planning and design for water and wastewater treatment facilities, from calculations to deliverables like technical memoranda and design packages. You'll work under supervision but with real responsibility, coordinating with multidisciplinary teams to align treatment needs with overall facility design. It's ideal for someone who wants to make a tangible impact on water infrastructure while enjoying the flexibility of remote work and part-time hours.

A typical day

A typical day might involve performing hydraulic calculations for a new membrane bioreactor system, reviewing water quality data from a client's facility, and drafting a section of a basis of design report. You'll also have a virtual coordination meeting with structural and electrical engineers to align on design drawings, and later summarize your findings in a technical memorandum for the project manager. The work is varied, technically challenging, and directly contributes to sustainable water solutions.

Who AECOM is looking for

Holds a Bachelor's degree in Civil, Environmental, or Chemical Engineering, with 2-4 years of experience in water/wastewater treatment design or planning.
Demonstrates strong technical skills in engineering calculations (e.g., hydraulic, process, mass balance) and familiarity with treatment processes like coagulation, filtration, disinfection, or biological treatment.
Has experience preparing technical memoranda, basis of design reports, and coordinating design drawings/specifications; proficiency with AutoCAD, Revit, or hydraulic modeling software is a plus.
Is a collaborative communicator who can work effectively in remote teams, manage part-time schedules, and summarize complex data clearly for clients and internal stakeholders.

Tips for this application

Tailor your resume to highlight specific water/wastewater treatment projects, including any experience with drinking water, wastewater, or reuse—use keywords from the job description like 'basis of design,' 'opinions of probable cost,' and 'multidisciplinary teams.'
In your cover letter, explicitly state your interest in AECOM's Water Business Line and mention the Denver office or Colorado water projects to show you've done your homework and are not just applying to any remote role.
If you have experience with remote collaboration tools (e.g., Microsoft Teams, BIM 360, Bluebeam), mention it—AECOM values seamless remote teamwork, and this role is fully remote.
Quantify your impact where possible: e.g., 'Assisted with design of a 10 MGD wastewater treatment plant upgrade' or 'Prepared calculations that reduced chemical usage by 15%.'
Apply through AECOM's careers portal and, if possible, connect with a current AECOM water engineer on LinkedIn to ask a thoughtful question about the team or projects—this can help your application stand out.

What to cover in your cover letter

["Your specific technical experience in water/wastewater treatment, including any design or planning work on treatment facilities, and how it aligns with AECOM's projects.", 'Your ability to work collaboratively in multidisciplinary teams, especially in a remote setting, and examples of coordinating with other engineers or disciplines.', 'Your familiarity with preparing deliverables like technical memoranda, basis of design documents, and design packages, and your attention to detail in reviewing data and summarizing findings.', "Why AECOM and why this part-time remote role—show enthusiasm for AECOM's sustainability mission and the flexibility this position offers."]

Draft a cover letter

Research before applying

Explore AECOM's Water Business Line page and recent projects, especially in Denver or the western U.S., to understand their focus areas like potable reuse, PFAS treatment, or resiliency.
Read AECOM's latest sustainability reports or press releases to grasp their commitment to sustainable legacies and how water treatment fits into that vision.
Research common water treatment regulations and trends in Colorado (e.g., Colorado Water Quality Control Division, nutrient standards) to speak knowledgeably about local challenges.
Look up the backgrounds of AECOM's water leadership in Denver on LinkedIn to understand their expertise and potential interviewers.

Likely interview topics

Based on the job description, expect questions about:

Walk us through a water or wastewater treatment project you supported from planning through design. What was your specific role and what challenges did you overcome?
How do you approach engineering calculations for a new treatment process? Give an example of a calculation you performed and how you verified its accuracy.
Describe a time you coordinated with multiple disciplines (e.g., structural, electrical, process) to align treatment needs with overall facility design. How did you ensure effective communication?
What experience do you have with preparing technical memoranda, basis of design reports, or opinions of probable cost? Can you share a sample or describe the process?
This role is part-time and fully remote. How do you manage your time and stay connected with a team when working remotely? What tools or strategies do you use?

Practise interview questions

Common mistakes to avoid

Submitting a generic resume that doesn't highlight water/wastewater treatment experience—this role requires specific technical skills, so omitting relevant projects or calculations is a major red flag.
Ignoring the part-time and remote nature of the role in your application—if you don't address your ability to work part-time and remotely, recruiters may doubt your fit.
Failing to demonstrate collaborative skills—AECOM emphasizes multidisciplinary teamwork, so focusing only on individual accomplishments without showing how you work with others can hurt your chances.

Deadline

No deadline is listed. Roles without a deadline usually close once the employer has enough candidates, so apply soon if you are interested.