Principal Water Quality Scientist​/Modeller

About the Role

Principal Water Quality Modeller in AECOM’s Water Environment team. You will lead technical work for water utilities, industrial clients, government agencies and local authorities, mentoring junior staff and developing innovative solutions across rivers, lakes and coastal water bodies. The role is based in a UK office with flexible hybrid working options.

• Conceptualise and scope modelling approaches, assessing risks and opportunities.
• Build and validate water quality models for Integrated Water Management Plans, permitting studies and EIAs.
• Use modelling packages such as MIKE+, MIKE
  21/3 HD, AD, Ecolab, Info Works ICM, SAGIS‑SIMCAT or Cormix.
• Produce and review high‑quality technical reports that document model development and uncertainties.
• Lead input into tenders, from one‑off projects to multi‑million pound framework contracts.
• Mentor team members to support their professional development.
• Build relationships with clients and cross‑disciplinary teams.
• Stay current with legislation and guidance that affect our services.
• Use AECOM’s project management systems to deliver outputs within agreed programme and budget.
• Collaborate with engineers and specialists to deliver fluvial and coastal surface water quality projects.

• Catchment‑wide chemical investigations for water companies.
• Environmental Improvement Programme (WINEP) studies, investigating algal blooms in reservoirs and developing mitigation.
• Design, modelling and installation of Natural Flood Management measures and river restoration schemes.
• Catchment‑wide river restoration plans for the Environment Agency and water companies.
• Nutrient modelling in rivers, lakes and estuarine/coastal environments.
• Modelling to inform management decisions such as water‑level dependent designated sites.
• Desk studies, consultation, water quality monitoring and site surveys for developments, including WFD assessments and Environmental Permitting.
• Undertaking UPM studies and storm overflow investigations for water companies.
• Derive strategies to improve catchment water quantity and quality under WFD and Local Nature Recovery requirements.

• Expertise in water quality, including knowledge of cryptosporidium, PFAS, geosmin and disinfection by‑products and their treatment.
• Experience with fluvial and/or coastal water quality modelling software and demonstrable knowledge of Environment Agency UPM or WINEP studies.
• Proficiency in mass balance calculations (simple, flow‑weighted, Monte Carlo) and hydrological assessment tools such as REFH2 or FEH.
• Practical knowledge of scripting (Python, Anaconda, R) and strong GIS skills (QGIS, ArcGIS or Map Info).
• Master’s degree (or equivalent) in hydrology, engineering, mathematics or a related discipline.
• Demonstrated experience in technical project delivery from bid preparation to project management, with strong report writing and presentation skills.

• Leadership experience in technical projects and tendering.
• Understanding of UPM, WINEP requirements and related modelling.
• Knowledge of the regulatory framework for water quality in the UK.

If you meet some of the requirements above or have transferable skills that would benefit us, we would be delighted to hear from you.

AECOM is an Equal Opportunity Employer. We believe in each person's potential and welcome applications from all backgrounds.