Senior Process Engineer – Water & Wastewater Treatment

About the role

PACT Engineering FZC is seeking an experienced Senior Process Engineer with strong technical expertise in the design and engineering of industrial and municipal water treatment, desalination and wastewater treatment plants. The successful candidate must be able to develop process designs independently, perform engineering calculations, prepare technical documentation and coordinate with multidisciplinary engineering teams on EPC and packaged treatment plant projects. The position is based in Riyadh.

Key responsibilities

• Develop and review process flow diagrams, piping and instrumentation diagrams, process descriptions and design basis documents.
• Perform process calculations, hydraulic calculations, mass balances and equipment sizing.
• Design and select water and wastewater treatment processes, including reverse osmosis, ultrafiltration, multimedia filtration, activated carbon and greensand filtration, chemical pretreatment, clarification, coagulation, flocculation, sludge treatment, sewage treatment plants, MBR, MBBR and SBR systems, chemical dosing, neutralization, disinfection and CIP systems.
• Prepare equipment datasheets and technical specifications, hydraulic profiles, pump head calculations, control philosophies, process control narratives, cause-and-effect matrices and operating sequences.
• Review vendor offers, drawings and calculations, prepare technical bid evaluations and vendor document review comments.
• Coordinate with mechanical, electrical, instrumentation, automation and project engineering teams, review 3D models and equipment layouts, and respond to client technical comments, RFIs and clarifications.
• Support HAZOP, design reviews, FAT, pre-commissioning, commissioning and performance testing.

Required profile

• Bachelor's degree in Chemical Engineering, Environmental Engineering or a closely related discipline.
• Minimum 8-10 years of direct experience in water and wastewater treatment engineering.
• Strong knowledge of RO design, membrane systems, filtration, chemical dosing and hydraulic calculations.
• Familiarity with AWWA, ASTM, ASME and international water treatment standards.
• Experience taking a water treatment project from design basis through detailed engineering and supporting commissioning; EPC contractor, OEM or engineering consultancy experience preferred.

Required skills

• Proficiency in AutoCAD and MS Excel.
• Engineering calculation tools.
• Membrane design software such as WAVE or ROSA is an advantage.
• Strong technical reporting, engineering documentation and English communication skills.