Case Study 1:

Oil Spill at Commercial property, in Lisburn , Northern Ireland

The site is situated in Lisburn, Northern Ireland.  Staff ordered a fill of kerosene in mid-August 2008.  The oil supply system was fitted with an automatic ordering link to the oil supply company who duly delivered more oil at the beginning of September 2008.  Due to the timescale between deliveries close observation of the volume of kerosene being used was maintained and it was discovered that as much as 1500 litres of oil was being lost per day.

AES-Marconi were contacted and requested to perform an emergency response situation. AES-Marconi responded to site within 1 hour of notification and containment measures were put in place to prevent any further migration.

A prompt investigation was undertaken to establish the cause of the loss and an excavation performed along the route taken by the oil supply line from the bund area to the boilers.  A hole was subsequently found in the line. It is estimated that 10,000 litres of oil were lost during the incident.

Upon completion of the initial emergency procedures AES-Marconi performed a full site survey.

During the site walkover visual contamination could be seen and sections of the asphalt had disintegrated due to the affect of the kerosene.

Upon completion of soil gas survey and  borehole investigation it became evident that contamination was indeed present at the site.

Hydrocarbon contamination was found to be present beneath a large section of the asphalt area either side of the excavation.  A section of the land  between the bund and the boundary fence contained quantities of oil.

Due to the nature of the site a combination of excavation and in-situ remediation was instigated to remove the contaminated asphalt and underlying contaminated sub-soils.

During the exaction process it was discovered that kerosene had migrated to depth greater that the permissible excavation.

 In order to return the rear of the site to normality, large diameter injection and recovery wells were installed throughout the remaining contaminated areas and the excavated areas backfilled with clean hardcore. whereupon an automated  in-situ treatment system was utilised using

AES-Marconi novacells and proprietary treatment materials.
A pump and treated remedial strategy was instigated for a period of 12 weeks utilising automatic bacteria / nutrient dosing equipment. The levels of contamination were monitored throughout the treatment programme until levels of residual contamination were reduced the below guidelines.

Once all areas had been  indentified as having been remediated the site was independently verified and the asphalt and other structural components reversed and the site left to the customer’s satisfaction.