My current project is construction of a mega highway in Qatar and one small section of the roadway clips the corner of a previously unidentified active landfill site which will need removal and backfilling to complete the road.

Does anybody have specific experience of removal of such materials?

We have full soils contamination and gas analysis reports indicating high levels of Methane in localised hot spot with no significant soils contaminants as the waste is generally household and construction materials with no trace of benzenes, H2s or other hydrocarbon residues.

The affected area is at the side of a previous licensed landfill quarry however very poorly implemented and managed with no liners, gas vent pipework or leachate sumps etc.

We have top of the range PID's and 4 gas monitors used for the investigations with constant monitoring and appropriate powered full face respirators and correct cartridges and are now planning to undertake the works.

The volume is approximately 100,000 m3 to a depth of 12m and I would be interested if anybody has any contacts or reference material to ensure every angle is considered in the planning and preparations for the activity.

I am particularly interested in equipment controls such as spark arrestors, dust suppression as well as treating the whole area as confined space with appropriate rescue equipment and procedures with Occ. Health as an absolute priority.

We are also exploring alternative soil stabilisation and venting options as a preferred scenario with soil remediation consultants to minimise human exposure to potential hazards.

Any guidance and experiences greatly appreciated.

Andy Merrison 

Mike is absolutely right you need expert geoengineering help.  Encapsulating, especially as this is a highway, is far better than the removal of such large volume.  Appropriate venting can be installed without major problems.