Case Study 1

The site was situated at surveyors office in Belfast. The staff first discovered a strong hydrocarbon smell in the office kitchen.  Upon investigation oil was found to have been leaking from the fittings of the oil tank and boiler situated in the courtyard between the kitchen and the main underground boiler room.  The amount of oil lost was estimated at approximately 200 litres.

AES-Marconi was requested to perform a contamination survey at the above-mentioned property in order to ascertain the extent of contamination present and submit a proposal and costs to remediate the site.

On arrival at the site there were obvious signs that a pollution incident had occurred. There was an amount of oil present on the surface of the cobbles in the rear section of the courtyard.  A small excavation had been cut as part of the on-going boiler maintenance programme, which contained an amount of oil at the time of the survey.  Several bags of oil absorbent granules were distributed around the site to halt any further migration of contaminants.  An AES-Marconi plumber was called to the scene to replace the damaged and still leaking fittings.
 
The contamination had migrated outwards from the tank into the main courtyard, extending around the corner of the kitchen for a few meters.  The contamination had also found its way through the foundations of the kitchen and toilet block.  The bulk of the lost kerosene had travelled by way of the existing gradient into the main boiler room covering a large section of the sub-soils there in. 

AES-Marconi were authorised to proceed with the recommended remedial strategy which consisted of a mixture combination of excavation and in-situ treatment. The combination was recommended due the access restraints and also to reduce the disruption to the occupants of the property.

Contaminated soil and fill was removed to a depth of 1 metre whereupon a cut off system comprising a collection trench and automated pumping system was installed along the foundations of the kitchen in order to capture any mobile hydrocarbons for subsequent safe disposal.

When all of the contaminated ground had been identified an intensive treatment programme was employed using propriety bacterial cultures and saponics.

When all of the affected areas had been successfully treated, and any temporary modifications had been performed, the site was independently verified and the structural components of the site were reinstated the customers satisfaction.