Student Accommodation – London

REQUIREMENT

A 3.5m deep extremely large foul waste concrete chamber at the base of a three-storey basement required cleaning of all debris. Due to the location and low oxygen levels in this chamber, it appeared that the works required confined space entry using a remote BA trolley, a high vacuum combination jetter and tanker capable of removing waste 25 metres below ground level and a jetting facility suitable to break up the raft of waste material, in order that the suction pipe could withdraw the waste without blocking.

METHOD

A full appraisal survey of the site and required works was undertaken to ascertain the safest manner in which to execute the works to remove the vast raft of waste within this chamber and ideally to mitigate any personnel entry to the chamber. A high vacuum combination jetter and tanker was used to jet the raft of waste material from above the chamber in order to break down the waste. The waste was then removed from the chamber using the tanker’s suction line. To remove the final sections of waste an entry was required to the chamber, but as the majority of waste had been removed, the gas detection levels for Oxygen was safe and the entry did not require the BA. However, the BA was available on site to ensure that the works could be facilitated within the allotted timescale and budgeted costs.

RESULT

The chamber was cleared of all solids waste from this chamber, resulting in a reduced risk of blockage to the pumps and therefore a reduction in costs. A subsequent regime of periodic jetting and cleaning was then put in place as part of the PPM.

FOCUS ON:

Jetting

High pressure drainage jetting is a highly effective way to clear blocked drainage pipes within all manner of waste drainage systems, such as ground water pumped systems, storm water pumped systems and foul water pumped and gravity systems. Blockages can occur over time due to an initial build-up of material or the blockage can be as a result of a one-off item.