How Thames Water Uses Robotic Technology to Improve Slow Sand Filter Maintenance

Exploring automated sand filter cleaning to maintain water output while reducing labor and operational downtime

Thames Water is the United Kingdom’s largest water utility, serving over 15 million residents and managing extensive infrastructure, including reservoirs, treatment plants, pipelines, tanks, and basins. Across this network, maintaining consistent water output and water quality requires continuous management of sediment buildup, algae blooms, and aging concrete linings—factors that can compromise flow rates and operational efficiency if left unaddressed.

“We’re exploring robotic sand filter cleaning with the SSF-800 to maintain water output while minimizing labor and downtime.”
— Maintenance Planning Lead, Thames Water

Manual skimming of slow sand filters has historically created bottlenecks in treatment operations. The process requires significant labor input, cannot always be performed on demand, and can limit operational flexibility. In response, Thames Water initiated a pilot with Weda’s SSF-800 robot, a surface skimmer specifically designed for slow sand filter maintenance. The unit enables on-site, instant cleaning with minimal disruption, supporting continuous water treatment performance without the need to drain assets.

By exploring robotic sand filter cleaning technology, Thames Water is aligning slow sand filter maintenance with modern water infrastructure standards. The adoption of automation supports improved operational reliability, reduced downtime, and enhanced asset longevity—helping ensure stable water supply and service continuity across the UK.