Torra WTW – Major Upgrade and Expansion Work

Torra WTW is a key water treatment facility on Islay, which is undergoing major upgrades to ensure reliable, high-quality drinking water for the local community.

Overview

Torra Water Treatment Works (WTW) is located on the Isle of Islay on the west coast of Scotland, and serves approximately 1,900 customers in the Bowmore and Port Ellen areas. The facility currently produces around 810,000 litres of clear drinking water daily, with the scope for enhancements required to increase capacity and resilience for future demand.

Upgrades and Expansion

Scottish Water has begun the construction of a new £31 million Torra WTW, which will be adjacent to the existing plant and includes improvements to access roads and site infrastructure, with the project expected to take around 18 months to complete.

Key features of the upgrades and expansion to the works include:

• Transportable Treatment Units (TTU®): 19 state-of-the-art TTUs® will be installed, providing an additional 590,000litres of drinking water per day. The modular units were built off-site and transported to Islay, enhancing construction efficiency and future scalability.
• Membrane Technology: RSE designed, constructed and commissioned a new spiral membrane Water Treatment Works at Torra, increasing treatment capacity from approximately 0.81 ML/d (810,000 litres/day) to 1.4 ML/d (1.4 million litres/day
• Clear Water Tanks: The capacity of the clear water tanks has increased from 810,000 litres to 1.4 million litres.

Project Delivery

RSE is collaborating with Scottish Water as project delivery partner to implement the upgrades. A major milestone has already been achieved with the successful load out and transportation of all 19 TTU®s from the state-of-the-art RSE fabrication facility in Muir of Ord. Each module was fully fabricated, assembled, mechanically and electrically installed, and tested within a controlled factory environment before shipment. This offsite modular approach has enhanced quality control, improved safety, and will significantly reduce onsite installation durations.

RSE's approach combines off-site modular manufacturing with digital delivery to enable a reduction in project timelines by up to 50% compared to traditional construction methods. Our teams are focused on streamlining how information moves across projects, from design teams to fabrication workshops and client stakeholders. Central to that strategy is the adoption of Autodesk Construction Cloud (ACC), where teams can now collaborate directly within shared models, eliminating traditional communication barriers and enabling the workshop floor and design office to effectively operate as one team.

Extensive logistics planning was also required to coordinate the transportation of the TTU® modules, involving road haulage, ferry crossings and close collaboration with local authorities, transport contractors, and ferry operators. The successful delivery of these modules demonstrates the strength of RSE's integrated design, manufacturing, and delivery teams in overcoming challenging programme and logistical constraints, bringing the new treatment works one step closer to providing a resilient drinking water supply for the island.

Benefits and Impact

The upgrades at Torra WTW aim to:

• Enhance water supply reliability for existing customers and support future housing developments in areas like Imereval and Bowmore.
• Reduce reliance on water tankers by providing additional on-site capacity and resilience.
• Ensure high-quality drinking water through modern treatment processes and improved storage capacity.

The modular upgrade to Torra WTW represents a significant investment in Islay's water infrastructure, combining modern treatment technology with increased capacity to meet both current and future community needs. With this key milestone achieved, our project teams now look forward to progressing the programme through the installation, assembly, and commissioning phases of the project, as the new treatment works takes shape on site.