Knights Brown was awarded the Rotherwas and Eign Waste Water Treatment Works (WWTW) contract under our Capital Delivery Alliance Framework for Welsh Water Dwr Cymru.
The High Rate Filter (HRF) at the waste water treatment works was to be decommissioned and a replacement constructed. Knights Brown installed the new ductile iron pipework to connect the pumping station to the new HRF and existing humus tank.
Prior to the start of work, we attended multiple design meetings with Skanska, Arcadis and Sewaco, the HRF tank builder, to look at how the design would work during the construction phase. We resolved issues related to the installation of the piled foundation and the planned route for the ductile iron pipework below the foundation.
The general scope of works included:
• Trial holes
• Excavation and installation of temporary works
• Installation of over 300m of 450mm and 600mm ductile iron pipework to an average depth of 3m and testing
• Construction of manhole chambers
• Installation of service ducts and draw pits
• Construction of concrete footpaths
• Kerbing and resurfacing works
• Landscaping works
As a live waste water treatment works on private land the records of existing services and structures was deficient. To overcome this, extensive trial holes, surveying and planning of temporary works was imperative for safe installation of the pipework.
Air testing was conducted throughout installation, as well as a hydraulic test of the pressurized 450mm pipework on completion.
Additional works included construction of a brick valve chamber, concrete footpaths and upsizing of pipework at the nearby Eign WWTW.