Tonnage
10tph
Material
Filter Sands
Output
High Quality Filter Sands
THE CHALLENGE
Essex & Suffolk Water provides water services for 1.8 million people in Essex, Suffolk and parts of East London and is part of Northumbrian Water Limited (NWL). . At the water treatment works in Langham and Ormesby, raw water is treated using slow sand filters to produce potable water. This is then delivered by a network of pipes to homes and businesses in Essex and Suffolk. The Essex area, which has a population of 1.5 million, is part rural and part urban with the main areas of population being in Chelmsford, Southend and the London Boroughs of Barking and Dagenham, Havering and Redbridge. The biggest towns in the Suffolk area include Great Yarmouth and Lowestoft.
The filter sand washing process
Filter sand washing has been a reliable method of water purification in the UK for approximately 150 years, requiring no chemicals or electricity to operate. The process takes place over a large surface area, with both water treatment works having up to twelve large beds, and involves the formation of a biofilm of living organisms on top of a fine layer of sand. The sand and biolayer is submerged in water allowing the organisms to eat potentially harmful pathogens while clean, potable water filters through the sand.
THE SOLUTION
An important part of the filter sand washing process is maintaining the cleanliness of the sand to ensure clean water and an optimum rate of flow through the filter. At the Langham works, the filter is drained and the sand is skimmed off and washed before being laid back down again allowing a new biofilm to develop. CDE equipment was chosen to replace the current sand treatment system which was installed in 1998.
THE RESULTS
The CDE filter sand treatment systems were installed at both water treatment works during 2017. They will provide a consistent supply of clean, dry filter sand which is uniform in size and meets all the requirements for slow sand filtration media.
Fred Aujoux, Asset Delivery Programme Manager at Essex & Suffolk Water, said: “Our investment in this new technology reflects our sustainable approach and will ensure a more efficient process and helping to secure water supplies for our customers through improved and reliable equipment. This new sand treatment process will allow us to continue with this traditional method of water purification for many years to come; a method which we consider to be the most sustainable, low-energy solution for water purification while protecting future generations”.
