Laboratory à Grande-Bretagne

United Infrastructure is a dynamic, rapidly expanding business, delivering critical infrastructure to communities across the UK.

We pride ourselves on delivering innovative solutions to the complex challenges our clients face in five key sectors: water, energy, power, telecoms and property services, under two main business areas – Utility Infrastructure and Social Infrastructure. We employ over 2200 people and work with a broad range of public and private sector clients.

We are dedicated to creating a connected, sustainable future, and our work plays an important role in achieving the UK’s net zero ambitions. We deliver infrastructure that supports the energy transition as well as improving the energy efficiency of thousands of homes and addressing industry skills gaps by providing formal qualifications and training in the net zero space.

We are a fast-paced, diverse, and hugely ambitious business. We welcome challengers, innovators and people who embrace change and want to establish themselves in a creative environment that champions freedom of expression and supports them in their personal and professional development – because together, we achieve more.

OverviewWe’re looking for a skilled and safety-focused Water Mains Chlorination & Commissioning Technician to join our Network Improvement team. In this role, you’ll be responsible for the safe, efficient, and compliant chlorination, pressure testing, and commissioning of newly installed water mains and services. You’ll play a vital part in protecting water quality, ensuring network integrity, and supporting the smooth handover of completed assets in accordance with Northumbrian Water (NWG) standards, industry regulations, and United Infrastructure operating procedures.

• Carry out chlorination of new and repaired water mains using approved methods.
• Calculate chlorine doses, volumes, retention times, and neutralisation requirements.
• Safely neutralise and dispose of chlorinated water using approved de-chlorination equipment and chemicals.
• Collect water samples post-chlorination for laboratory analysis and maintain accurate test data.

• Conduct hydrostatic pressure tests on mains and services using calibrated equipment.
• Verify pressures, durations, and allowable drops in line with standards.
• Identify and report leaks or integrity issues promptly.
• Complete all logs, paperwork, and digital records for test certification.

• Adhere to NWG protocols and United Infrastructure operating procedures.
• Maintain high standards of hygiene, pipe cleanliness, and contamination control.
• Support site teams in proper pipe storage, capping, and protection.

• Complete chlorination certificates, sampling logs, and pressure test results.
• Submit documentation to planners, commissioning engineers, and NWG representatives.
• Maintain accurate records for audit and compliance purposes.

• Operate, maintain, and calibrate chlorination rigs, pumps, and testing equipment.
• Inspect hoses, connections, and backflow prevention devices for compliance.
• Report defects and ensure all equipment remains certified and safe.

• Follow NWG and United Infrastructure safety standards, including Zero Harm principles.
• Carry out risk assessments and comply with COSHH, PUWER, and HSG47 regulations.
• Handle and store chemicals safely, preventing environmental harm through proper wastewater management.

• EUSR National Water Hygiene certification.
• Proven experience in chlorination, pressure testing, commissioning, or related water-sector work.
• Good understanding of water industry standards and procedures.
• Full UK driving licence.
• Strong practical skills and effective problem-solving ability.
• Excellent communication with site teams, planners, and NWG inspectors.
• High attention to detail and strong commitment to safety and water quality.
• Safety-first mindset: Committed to Zero Harm and contamination prevention.
• Quality-driven: Strives for first-time acceptance and compliance.
• Organised and methodical: Maintains clear, accurate records.
• Proactive and collaborative: Works effectively with site crews and supervisors.
• Customer and compliance focused: Protects water quality, supply, and delivery schedules.