Bell Island sludge tank & pipework

21 May

Project Spotlight: Bell Island Sludge Tank and Pipework Upgrade

In September 2023, Kernohan Engineering was engaged by Nelmac to deliver a major upgrade to the sludge management infrastructure at Bell Island. With the certificate of completion issued in January 2025, this complex mechanical and civil project marks a significant improvement in the site’s operational capability and resilience.

A Fit-for-Purpose Tank Replacement

At the heart of the project was the design and installation of a new 120,000-litre stainless steel sludge tank, built to replace the existing structure. The tank, made from 316 stainless steel, was designed for durability in a corrosive environment and to ensure seamless integration with the surrounding infrastructure.

Measuring 6000mm in diameter and standing over 6 metres tall, the tank includes:

Eight pipe penetrations to accommodate a range of pipe sizes and process requirements
A manway access door weighing approx. 180kg, complete with a davit arm to support safe access and maintenance
A tapered concrete floor that directs sludge to a centrally positioned pipe connected to a Vaughan chopper pump
An integrated recirculation system via internal mixer nozzles to maintain effective sludge movement

This design allows for operational flexibility—the pump system can be bypassed when needed, with the sludge redirected to a transfer pump feeding back into the existing network. A series of manual and automated valves (supplied by others) manage flow and switching between processes.

Pipework and Platform Integration

Kernohan’s scope also included the full mechanical pipework installation, along with the design and construction of foundation pads for the tank, pumps, and access structures. A robust pigging platform was installed on the eastern sideof the tank, enabling system cleaning and maintenance.

The pigging station includes:

A bolted access box with an internal cage to catch the pig
Welded sockets for water flushing before manual access
Potable water supply for a hand basin, washdown hose, and emergency shower

The pump pad also features key safety and hygiene facilities, including a potable water supply, reused water for washdown, and an airline system running across both pads to support automated valve operation in the sludge line.

A Robust and Reliable Outcome

Despite the technical complexity and multiple coordination points across civil, mechanical, and safety systems, the project was successfully delivered to specification. The new tank and associated systems will support long-term performance for the Bell Island site, ensuring continued environmental compliance and operational efficiency.

This project is another example of Kernohan’s capability in delivering complex infrastructure upgrades, with high standards of safety, quality, and client collaboration at the core of every phase.