South West Water was one of the first companies to install the Mono Discreen® nearly 20 years ago, which featured a 5.5mm screening aperture. It was installed into the CSO chamber underneath the green adjacent to Grange Road in Helston, Cornwall, where it was used to limit flow into the downstream sewer and treatment works, and control the aesthetic load carried into the watercourse.

Keen to upgrade its storm overflow with Mono’s latest Discreen product, which features an even finer screening aperture of 2.5mm, South West Water asked the company to supply and install a new L Series Discreen, complete with new support framework, to screen stormwater at a capacity of 900m3/h.

Mark Netherton, Commissioning Engineer at South West Water commented: “We specified Mono as we were more than happy with our existing Mono Discreen and we could carry out a ‘like for like’ retrofit with minimum fuss.

“We wanted to benefit from the latest screening technology and improve our facility in order to meet tighter EA consent, and Mono offered a solution that we could trust.”

Mono’s L Series Discreen has the ability to remove up to 95% of solids, is self cleaning and does not blind or require manual raking or cleaning. It is constructed using a number of shafts, each fitted with discs that overlap and intermesh with corresponding shafts.

The shaft rotation forms a gentle conveying action of solids across the face of the screen to the discharge point, while allowing water to flow through the disc stacks. Individual comb bars are fitted to the first and last shaft to eject screening solids for discharge back into the main flow or sump area. This removes the need to collect and manually dispose of extracted debris, significantly reducing labour and disposal costs. The individual discs on a Mono Discreen also allow easy, low cost maintenance should they need replacing.

Available to fit various channel widths and depths, the Discreen is ideally suited to water abstraction intakes, inlet works, storm overflows and pump stations. 

It can also be packaged with a Mono Muncher® to screen and grind solids for the protection of pumps, or as part of a complete extraction package for screenings removal, compaction and dewatering.