Residents in the Duncan Road area of Ramsgate had endured unpleasant odours from local sewers for some time when MTS arrived to clean the sewer chambers. Sewage had backed up behind hydro-breaks and penstocks in the holding chambers and MTS crews found accumulated rag, fat and silt more than one metre deep as far as the naked eye could see.
The chamber system was designed to provide storm relief for heavy rain, filling with water in order to avoid overloading the pumping station downstream. Penstocks and hydro-breaks slow down the flow in storm conditions, but the blockages had drastically reduced capacity and created odours.
The chambers varied in depth from five to 20 metres and our specialist confined space entry crews used full breathing apparatus because of potentially deadly toxic gases. The teams needed intrinsically safe electrical equipment, including lighting, for the chambers which were two metres wide and more than two metres high. In addition, specialist communications equipment ensured constant contact with the surface.
Full CCTV surveys showed the progress of this weather-dependent work which took eight weeks to clean six chambers. After the crews had broken up the solid waste, super suction tankers used 6in suction pipes to remove it, leaving the chambers, penstocks and hydro-breaks clear.