“The run lengths went from an average of 20 hours up to 60 hours.”
Sébastien Lesourd
Manager of the Angers Loire Métropole drinking water production plant
The Ponts de Cé drinking water treatment plant, operated by Angers Loire Métropole, produces an average of 60,000 m³ of drinking water per day from the Loire River and its alluvial aquifer. To improve filtration performance and operational efficiency, the plant launched a pilot project in 2019 to test Filtralite® Pure Mono-Multi, a dual-media filter bed made from expanded clay aggregates.
Pilot Testing Confirms Significant Improvements
During the pilot phase, one of the plant’s filters was equipped with Filtralite media instead of conventional filter material. Over the course of the trial, the system demonstrated a remarkable increase in filtration run lengths, with intervals between backwashes rising from an average of 20 hours to up to 60 hours.
This threefold improvement reduced water consumption for backwashing, lowered energy use, and stabilised filtration performance, all key factors in optimising plant operations.
Full-Scale Implementation Across the Plant
Encouraged by these results, the Water and Sanitation Department of Angers Loire Métropole decided to extend the solution to the entire facility. In 2021, Filtralite Pure Mono-Multi was installed in all 11 filters of treatment lines 1 and 2. With this upgrade, Ponts de Cé became the first drinking water plant in France to operate with a Filtralite dual-media filtration solution.
Dual Media Design Enhances Filtration Performance
The Filtralite Pure Mono-Multi system combines two types of filter media with different densities and grain sizes, creating an optimised filter bed that captures particles of varying sizes more effectively.
This configuration delivers longer filter cycles, higher production capacity, and improved water quality, all while reducing the water loss typically associated with frequent backwashing. As a result, the plant can produce more water without expanding its footprint and operate more sustainably.
A Sustainable and Cost-Effective Solution
The success at Ponts de Cé highlights the advantages of upgrading from conventional sand filters to Filtralite Pure Mono-Multi. The solution enables extended filter run times, lower operating costs, improved water efficiency, and enhanced resilience, demonstrating how modern filter media can significantly improve the performance and sustainability of drinking water treatment plants.
