PLC Engineer for Wastewater Treatment System

We are an established industrial water treatment company based in the United States looking for a highly experienced PLC/HMI engineer to assist with the development of a wastewater treatment chemical feed and process control system.

This is not a simple PLC programming assignment. We are looking for a contractor who can help develop portions of the control philosophy, identify design gaps, recommend best practices, and create a professional, maintainable control system that can be supported by our team long-term.

The project includes:

Chemical feed control systems
Polymer blending systems
DAF (Dissolved Air Flotation) process controls
Clarifier chemical dosing
pH monitoring
Turbidity monitoring
Conductivity verification
Flow-paced chemical dosing
Pump duty/standby control
Alarm management
Modbus TCP integration
HMI development
Startup simulation and FAT support

We currently have:

Preliminary process diagrams
I/O lists
Instrument lists
Hardware architecture
Wiring concepts
Initial sequence concepts
Process narratives

We need an experienced engineer to help transform these documents into a complete controls package.

Current Hardware

Current design is based on:

Maple Systems PLC-ES8006R
Maple Analog and Digital I/O
Weintek cMT HMI
Hach SC1000 Analyzer
Modbus TCP Communications
Endress+Hauser Picomag Flow Meters

Scope of Work
Phase 1 – Architecture & Design Review

Review provided documentation and develop:

Design review report
Questions / RFI register
Recommended control architecture
Alarm strategy
Communication architecture
Sequence of operation recommendations
Dosing control recommendations
Phase 2 – PLC Development

Develop reusable PLC modules for:

Analog input scaling
Broken-wire detection
Chemical dosing calculation
Flow-paced control
Pump control
Duty/standby alternation
Alarm management
Modbus communications
Data validation
Phase 3 – HMI Development

Develop:

Plant overview screen
Chemical feed screens
Polymer blending screens
DAF screens
Clarifier screens
Alarm screens
Trend screens
Security/user management
Phase 4 – FAT Support

Provide:

Simulation testing
FAT documentation
Deficiency tracking
Source-code documentation
Required Experience

Applicants MUST have experience with:

PLC Programming
Industrial Automation
HMI Development
Modbus TCP
Process Control
Pump Control Systems

Strong preference for experience with:

Wastewater Treatment
Chemical Feed Systems
DAF Systems
Polymer Systems
pH Control
Water Treatment Plants
Industrial Process Systems
Deliverables

Successful contractor must provide:

Complete PLC source code
Complete HMI source code
Tag database
Alarm database
Modbus register documentation
Network architecture documentation
Comments throughout code
FAT documentation
Change log
Ownership Requirements

IMPORTANT:

We will retain full ownership of all:

Source code
Function blocks
HMI files
Documentation
Intellectual property

No password protection or locked project files will be accepted.

The final deliverable must be fully editable by our internal team.

To Be Considered, Please Include
Your country of residence.
Years of PLC programming experience.
PLC platforms you have worked with.
Experience with Weintek HMI.
Experience with wastewater or water treatment projects.
Example screenshots of prior HMI projects.
Description of a Modbus TCP integration you completed.
Confirmation that you will provide full editable source code.
Availability for overlap with U.S. Eastern Time.
Estimated hours to complete Phase 1 Design Review.
Budget

Initial engagement will begin with a paid Phase 1 design review and architecture assessment.

Top candidates may be retained for additional phases including PLC programming, HMI development, FAT testing, future projects, and long-term support.