Works by Bournemouth Water to upgrade its Alderney Water Treatment Works have entered their final phase, with commissioning and testing of the site now underway.

Photo: Alderney WTW

The £115 million project, which began in October 2023, is a key part of Bournemouth Water’s £200 million investment programme to modernise its water treatment system, future-proof it against a changing climate and minimise the impact on the environment.

Once complete, the upgraded facility will use advanced technology to deliver more sustainable, cleaner, and more reliable drinking water for customers across the region.

Significant progress on site

Over the past year, major progress has been made on site as the new treatment works moves closer to completion. Since May 2025, Bournemouth Water has:

• Built four new treatment facilities fitted with advanced electrical and mechanical equipment to ensure all water that goes through the new works is fully treated so it’s clean and safe to use.
• Installed 20km of electric and fibre-optic cables to power the pumps and treat water across the site.
• Installed a new surface water drainage system to manage rainwater more effectively and stop excess water from flowing across the site.
• Weatherproofed all buildings with new roofing and cladding, fully sealing them against the elements

Currently, Bournemouth Water’s teams are installing new dosing systems on site to carefully control chlorine levels and maintain drinking water safety.

A major upgrade to the site’s power supply is also nearing completion, with new generators and transformers installed, commissioned and tested to improve reliability.

The team is working to test equipment in the new treatment process buildings including circulating water through sections of the site to confirm systems are operating as designed ahead of full treatment.

Work has also begun to create permanent roads and footpaths on site, marking the site’s transition from construction into operational use.

With testing on site well underway, over the next few months Bournemouth Water’s teams will be working to bring systems online in stages, with close monitoring at each step.

Photo: new process building at Alderney WTW

A key upcoming milestone is the installation of Granulated Activated Carbon, an essential part of the treatment process. The material has already arrived on site and will be installed in the new treatment building before being flushed and prepared for use.

Once fully connected, water will be run through the complete treatment process and tested regularly to ensure it meets strict safety and quality standards before the works is completed later this year.

Richard Stanbrook, Director of Drinking Water Services at Bournemouth Water, said:

“We’re now entering one of the most important phases of the Alderney project as we bring the new systems online.

“This investment will transform how we treat and deliver drinking water for over 250,000 customers, ensuring a more resilient, efficient and sustainable service for the future.”