St Mary’s Island on the Isles of Scilly is unique in the United Kingdom being almost totally dependent on desalination of sea water to blend with groundwater supplies for the islands drinking water supply.

During recent years the existing desalination system became beyond economic repair and as part of a major refurbishment scheme including new bore wells and new purpose engineered building, Kirton secured the contract to replace this with a larger and more efficient fully automatic system.

The new system comprises of 2 x 200m³/day reverse osmosis trains preceded by a common multi-media and cartridge filtration pre-treatment system. The system utilises pressure exchanger technology to achieve the lowest possible energy cost per cubic metre.

The system features full SCADA control with remote access and is predominately housed in purpose built containers to provide low cost yet durable housing for the plant components. Telemetry is provided together with email alert to alert the Operators on the need for attention to the system. The system was installed and commissioned mid 2013 and the permeate quality continues to comfortably meet specification requirements.