Case Study: Fuel System Decommissioning and Installation

This project involved the safe decommissioning, removal, and replacement of a fuel storage system, including underground tanks, pipework, and supporting infrastructure. With careful planning and industry best practices, we ensured a smooth transition from old to new, prioritising safety, compliance, and efficiency.

Project Planning & Site Preparation

Before work commenced, the project manager developed a detailed Gantt schedule, identifying long-lead-time items and key order points. A thorough Risk Assessment and Method Statement (RAMS) was prepared, and the site was set up with:

• Security & Welfare Facilities – Heras fencing, site office, welfare area, designated storage, and waste zones
• Safety Protocols – Defined site rules, muster points, and emergency response plans
• Electrical Disconnection – Power was isolated at the substation, fuse elements removed, and supply locked off – all DBs and components were tested to confirm the system was dead before electrical infrastructure was safely removed and recycled

With electrical hazards eliminated, fuel system decommissioning could begin.

Fuel System Decommissioning & Tank Removal

The existing fuel storage system was carefully dismantled. Non-entry tank cleaning was completed, removing all remaining fuel from the tanks, pipework, and associated components. Waste disposal was meticulously recorded, ensuring compliance with hazardous waste regulations. Above-ground pipework and fuel distribution infrastructure were then dismantled, categorized, and either recycled or sent for specialist hazardous waste disposal.

With the above-ground elements cleared, focus shifted to the removal of the underground fuel storage tanks. Breaking through the reinforced concrete casing required heavy-duty plant and precision techniques to control noise and dust levels. Over several days, hundreds of tonnes of concrete were carefully excavated to reveal the tanks. Once exposed, they were methodically cut, folded on-site, and transported for disposal through approved waste streams.

To maintain site safety, excavation edges were banked and segregated, while surrounding ground was tested for contamination. Any impacted soil was removed and processed through a local treatment facility. The excavation was then backfilled with recycled aggregate from local suppliers, compacted layer by layer using remote-controlled equipment to eliminate HAVS risks and excessive noise exposure.

New Fuel System Installation

With the site stabilised, the new fuel system was installed:

Underground Infrastructure

• Drainage and ducting systems laid to detailed specifications
• Temporary works permits issued for excavation and shoring
• Oil-Water Interceptor (OWI) installed, encased in concrete, and connected to drainage
• New drainage pipework installed and tested for tightness

Fuel Storage & Distribution

• Fuel tank positioned via contract lift, shimmed, and grouted
• Pipework pre-fabricated off-site, coded welded, and NDT tested before installation
• Isolation and anti-siphon valves fitted, with full in-situ pressure testing
• Fuel pumps installed and connected with SWA cables

Electrical & Safety Systems

• CompEx electricians completed all glanding and terminations for the fuel island
• Fire alarm system installed with intrinsically safe call points and 4G-linked monitoring
• Substation supply upgraded with an external rotary isolator
• OWI commissioned with high oil level alarms and automatic shut-off

Final Handover & Commissioning

Before project completion, all concrete pads and kerbing were sealed, and a tanker pot drop test was conducted following APEA Blue Book guidelines. The first fuel delivery soak test confirmed system performance, and all pumps were calibrated within client tolerance levels.

Line marking, safety signage installation, and final commissioning checks were completed in collaboration with key stakeholders. As-built drawings and full O&M documentation – covering mechanical, electrical, civils, and landscaping – were provided. With a successful handover, the upgraded fuel system was officially brought into service, delivering a safer, more efficient, and fully compliant solution.