Mechanical Site Supervisor – Water

Job Overview

OCU leads the way in end‑to‑end infrastructure engineering across the utilities, digital, and energy markets. We are seeking an experienced Mechanical Site Supervisor to join our growing Water sector team in Deeside. The role focuses on the delivery of wastewater infrastructure and treatment projects, supporting site operations across mechanical installation and maintenance works within live operational environments.

• Oversee day‑to‑day site operations across wastewater treatment and infrastructure projects, focusing on leadership, safety, coordination, and efficient delivery.
• Supervise daily site activities, subcontractors, and direct labour, ensuring all mechanical works are completed safely, in line with specifications, and to programme requirements.
• Oversee installations including pumps, pipework, valves, mechanical equipment, and associated infrastructure across wastewater treatment facilities.
• Conduct site inspections, quality checks, and safety audits while supporting the management of site resources, workflow planning, and productivity.
• Support incident and near‑miss reporting, ensuring corrective actions are implemented and a strong safety culture is maintained.
• Ensure all site documentation, inductions, permits, and safety procedures are in place and compliant with company and industry standards.
• Work closely with project managers, engineers, and wider delivery teams to help ensure projects are delivered successfully within challenging operational environments.

• Previous site supervision or site management experience within the mechanical, water, or wastewater sector.
• Experience working on wastewater treatment projects; strong understanding of mechanical installations and site operations within live environments.
• Valid SMSTS or SSSTS qualification; IOSH or NEBOSH certification considered advantageous.
• Knowledge of confined spaces, deep excavation safety, and working at height practices.
• Strong leadership and communication skills; ability to coordinate teams, manage subcontractors, and maintain high safety and quality standards.
• Full UK driving licence.

At OCU Group, we believe that diversity and inclusion are fundamental to building a workplace where people feel valued, supported and able to do their best work. We are an inclusive employer and welcome applications from people of all backgrounds. As part of our commitment to fairness and equality, we may ask candidates to complete an equal opportunity monitoring form. This information is used for monitoring purposes only and plays no part in selection decisions.

We are a Disability Confident employer and will offer an interview to candidates with a long‑term health condition or disability who meet the essential criteria for the role. If this applies to you, please contact us at

Please inform us if you require any reasonable adjustments to our recruitment and interview process by emailing