27 September 2018
Work to restore the structural integrity of an Anglian Water wet well was completed this week.
The transfer of ownership of thousands of private pumping stations to water companies in 2016 amounted to significant, and often problematic additions to their asset bases. Periodic maintenance and cleaning of wet wells is essential to avoid blockages. With many wet wells difficult to locate and access this isn’t always possible or straightforward. Problems can also be caused by external factors such as vegetation and root ingress, as was the case with this wet well.
With visible signs of cracking to the wet well, CSC Services were contacted by Anglian Water to remove all vegetation and reline a wet well in the Colchester supply area, to prevent future problems and to ensure its structural integrity remained. Upon initial inspection of the wet well, tree roots were found to be entering the well through joints and pipe entry. Ring joints and grout holes were leaking. There were holes to the base, and cracks to the wall. 5-10mm of concrete had been lost from the walls and soffit.
CSC Services began the project by inserting pipe access bungs and setting up over-pumping to an intermediate bulk container. Confined space entry was then established. Once the atmosphere was tested and forced ventilation was set up the tree roots were cut out and removed. High pressure water jetting was undertaken to all surfaces.
All joints, grout holes, cracks and voids were sealed using Flexcrete repair mortars. A first coat of Monolevel 844 SP was applied to all surfaces which is a chemical resistant fairing coat to bring concrete back to profile.
Protective coating Cemprotec E942 was applied in two 1mm coats to all surfaces to provide protection from future Hydrogen Sulphide Attack. A physical check made to ensure coating was fully cured. Bungs were then removed and the wet well returned to normal service.
The Project Engineer for Anglian Water said:
“I was highly impressed with the level of detail that CSC Services provided on this job. The professionalism by the Project Manager and the working team is what I would expect to see from a specialist contractor. The works were carried out in the duration that was agreed, and updates on the progress of the job were communicated clearly. The finished product looks like a brand-new install. Any works required to this effect in the future CSC Services will certainly be the first call I make. Thanks for a great job.”
Images of Wet Well prior to refurbishment work undertaken
Images of Wet Well during refurbishment work