“With new filter materials, and especially Filtralite Pure Mono-Multi, we have increased the capacity of our water works without having to increase the actual footprint. Our research has been profitable.”
— Michael Chipps, Chief Scientist, Thames Water
Thames Water, the UK’s largest water and wastewater services company, supplies drinking water to millions of people across the country. In recent years, changing climate conditions and the increasing occurrence of algal blooms have placed significant pressure on its rapid sand filters, reducing their efficiency and reliability.
To address this challenge, Thames Water launched an extensive internal research programme to investigate alternative filtration media. The aim was to improve performance, extend filter run times, and reduce operational costs — all without the need for costly infrastructure expansion.
More than a dozen different filter materials — including sand, broken glass, sand/anthracite mixes, and Filtralite® Pure Mono-Multi — were tested under real operating conditions. Filtralite® Pure Mono-Multi, a dual-layer expanded clay filter media, consistently delivered the best results across all key performance indicators.
Traditional sand filters require long filtration cycles, frequent maintenance, and significant water and energy for backwashing. In contrast, Filtralite Pure Mono-Multi offers a much higher capacity to capture particles of varying sizes throughout the filter bed. Its open internal pore structure leads to lower head loss and significantly longer filtration cycles, reducing both water consumption and operational costs.
By switching to Filtralite Pure Mono-Multi, Thames Water has been able to extend filter run times and minimise backwashing frequency, leading to substantial savings in water and energy. The enhanced performance also means that existing filters can be upgraded rather than replaced, avoiding the need for costly new construction.
To date, 37 rapid sand filters have already been renovated with Filtralite Pure Mono-Multi, significantly increasing treatment capacity without expanding the plant’s physical footprint. The improved efficiency and reduced operational costs have saved Thames Water millions of pounds in investment while helping the utility meet growing demand under changing environmental conditions.
Designed for drinking water plants and pre-treatment for desalination, Filtralite Pure is a filter media suitable for both physical filtration and biological treatment
