WRc Clarity Design & Installation

Patented and industry-recognised, WRc Clarity actively reduces environmental pollution being discharged from CSO spills.

Paul Grabham is our expert in WRc Clarity

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Rethinking the CSO for the 21st Century

The design of the traditional combined sewer overflow (CSO) has remained the same for years, though additional screening has been retrofitted at existing CSOs or included at new CSO designs to achieve tighter aesthetic requirements. However, these screens require cleaning either mechanically or by operational staff and can entail high OPEX costs and residual H&S risks.

WRc has developed and patented a new CSO design that minimises environmental pollution, requires no power to be operational and can be manufactured as a modular unit offsite from partially recycled materials. Floating solids presented to the screen are reduced by over 90%. This means that WRc Clarity actively reduces environmental pollution being discharged from CSO spills.

      WRc Clarity design principles

      The innovative CSO is designed as a twin chamber with the upstream chamber producing a stilling pond effect, with the floating debris and sewerage litter accumulating and discharging via a bypass weir and continuation pipe. Therefore, this litter is retained in the sewerage network, transported directly to the Wastewater Treatment Works (WwTW) and not discharged to the environment.

      We believe this design can be part of the solution to achieving the requirements of the Environment Act and the journey towards lowering our carbon impact and achieving Net Zero targets.

      Industry-recognised innovation

      • Reduces debris presented to the screen by up to 90%.
      • Reduces pollution of watercourses and beaches.
      • Significant carbon savings in manufacture and operation.
      • Quicker fabrication and installation.
      • Improves reliability in network operations.
      • Modular concept increases flexibility.
      • Reduced OPEX costs over traditional powered solutions.

      WRc Clarity is trademarked and improves the environmental impact of CSO spills whilst the water industry - WRc included - search for further solutions to address environmental pollution in the long term. Its game-changing design was shortlisted at both the Institute of Water SWA Innovation Awards 2021 and the Water Industry Awards, for which it was named a 2021 finalist in the category 'Wastewater Innovation Project of the Year' and for a second time in 2022. WRc Clarity (known as WRcCSO at the time) won the 2022 RSK Innovation Awards.

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      Paul Grabham

      Head of Wastewater Infrastructure

      Paul has over 20 years’ experience in the water industry, relating to the technical delivery of sewerage studies, and recent experience of strategic planning, asset management and the inputs to the regulatory price review process. As Head of Wastewater Infrastructure at WRc, Paul's role involves the development of the strategy for business growth for our UK and international client base. He is a chartered member of CIWEM and an active member of the Urban Drainage community.