Senior Process Mechanical Engineer

Overview

This is a job description for a Senior Process Mechanical Engineer specializing in wastewater treatment and advanced water reclamation systems. This role is responsible for leading the development of process designs from concept through detailed engineering, including simulation, hydraulic analysis, and full facility design.

The engineer in this position shall be capable of transforming process simulations into practical, constructible treatment plant designs, including development of hydraulic profiles, PFDs, P&IDs, equipment selection, and facility layouts. This position requires deep expertise in biological treatment systems, including activated sludge, MBBR (Moving Bed Biofilm Reactor), and SBR (Sequencing Batch Reactor) technologies, as well as advanced membrane systems such as microfiltration (MF), nanofiltration (NF), and reverse osmosis (RO).

The Senior Process Mechanical Engineer will coordinate closely with multidisciplinary teams and support both project execution and business development efforts, including technical input for proposals and client engagements and any other tasks assigned by the Director of Engineering.

 

Key Responsibilities

1. Process Engineering and Design Development

• Lead process design development for wastewater and advanced water treatment facilities from conceptual design through Issued for Construction (IFC) deliverables.
• Develop and execute process simulations using industry-standard software such as BioWin or equivalent.
• Model and design conventional activated processes with biological nutrient removal (BNR) treatment processes including:
• Membrane Bio Reactor (MBR)
• Moving Bed Biofilm Reactor (MBBR)
• Sequencing Batch Reactor (SBR)
• Integrated Fixed Film Activated Sludge (IFAS)
• Bardenpho
• Modified Ludzack-Ettinger (MLE)
• Oxidation Ditch
• Translate process models into detailed engineering designs, including:
• Hydraulic Profiles
• Process Flow Diagrams (PFDs)
• Piping & Instrumentation Diagrams (P&IDs)
• Perform process calculations, mass balances, and system performance evaluations.

 

2. Advanced Treatment Systems Design

• Design and integrate advanced treatment systems including:
  • Microfiltration (MF)
  • Nanofiltration (NF)
  • Reverse Osmosis (RO)
  • Advanced Oxidation Process (AOP)
• Develop process configurations for water reuse and advanced water reclamation facilities.
• Perform membrane system sizing, recovery analysis, and fouling considerations.
• Integrate biological and membrane processes into optimized treatment trains.

3. Equipment Sizing and Facility Design

• Lead development of equipment sizing and selection, including:
  • Pumps
  • Blowers and aeration systems
  • Reactors and basins
  • Membrane systems
  • Chemical dosing systems
• Develop and review treatment plant layouts, ensuring efficient process flow and maintainability.
• Prepare and review:
  • General Arrangement (GA) drawings
  • Equipment layouts
  • Process system configurations
• Integrate standard technical drawing details into design packages.

4. Project Delivery and Design Milestones

• Lead process engineering deliverables through all project phases:
  • Conceptual Design
  • 30% Design
  • 60% Design
  • 90% Design
  • Issued for Construction (IFC)
• Ensure process design deliverables meet project schedule, budget, and quality requirements.
• Participate in and lead design reviews to validate process performance, constructability, and operational efficiency.
• Support commissioning and startup activities as needed, including troubleshooting and performance optimization.

5. Multidisciplinary Coordination

• Coordinate process design with:
  • Mechanical Engineers
  • Civil Engineers
  • Structural Engineers
  • Instrumentation & Electrical Engineers
  • CAD Designers
• Provide process design input for instrumentation, controls philosophy, and system automation.
• Ensure proper integration of process systems with electrical and control systems.
• Resolve interdisciplinary design conflicts and ensure coordinated engineering deliverables.

6. Technical Leadership and Mentorship

• Provide technical leadership and mentorship to junior and mid-level engineers.
• Review and validate engineering calculations, reports, and design deliverables.
• Contribute to the development of engineering standards, specifications, and best practices.
• Serve as a subject matter expert in wastewater treatment and advanced water reuse systems.

7. Business Development and Proposal Support

• Provide technical support to the sales and business development teams during project pursuits.
• Support preparation of:
  • Technical proposals
  • Process design narratives
  • Preliminary sizing and cost inputs including chemical and power
• Participate in client presentations and technical discussions.
• Assist in evaluating project feasibility and technical risks during bid/proposal development.

 

Qualifications

Required Skills and Experience

• Minimum 10–15 years of experience in wastewater treatment and water reclamation facility design.
• Demonstrated experience in process modeling and simulation, preferably using BioWin.
• Extensive expertise and experience in designing activated sludge process (ASP) and biological nutrient removal (BNR) treatment including solids processing. Specific types of systems include:
  • MBRMBBR
  • SBR
  • IFAS
  • Modified Ludzack-Ettinger (MLE)
  • Oxidation Ditch
  • Bardenpho
• Experience with advanced treatment systems:
  • MF / UF
  • NF
  • RO
  • AOP
• Proven ability to develop:
  • PFDs
  • Preliminary Design Reports
  • P&IDs
  • Hydraulic profiles
  • Process calculations
• Experience delivering projects from concept through IFC.
• Strong understanding of applicable standards including:
  • AWWA
  • ASME
  • ANSI
  • WEF guidelines
• Experience coordinating multidisciplinary teams.

 

Education and Certifications

• Bachelor’s Degree in Chemical, Environmental, Mechanical Engineering, or Civil Engineering.
• Professional Engineer (PE) license preferred in California, Arizona, Florida, or Colorado.
• Advanced training or certification in process modeling software is an advantage.

 

Work Conditions and Physical Requirements

• Up to 20–25% travel may be required for site visits, client meetings, and project support activities.
• Must be able to lift up to 30 lbs occasionally during site inspections or field verification.
• Work may involve both office and field environments requiring the use of personal protective equipment (PPE).

Salary Range

• $150,000-$185,000 USD