The Problem

• Failure of an automated pump resulted in the loss of over 20,000 litres of heating oil.
• The overfilled day tank was located on the 35th floor of an office building.
• Heating oil had seriously impacted lower plant rooms and office accommodation on five floors.
• Traces of oil were found over fifteen floors.

The Solution

• The most significantly affected floors were immediately evacuated.
• Containment and ‘mopping up’ of free oil was undertaken.
• An investigation including the drilling of concrete cores and recover of samples were undertaken.
• Affected areas were delineated and a re-instatement package devised.
• Contaminated fixtures and fittings were removed.
• Where possible, affected concrete screeds were removed. In plant rooms where this was not possible, bioremediation of concrete was undertaken.
• Residual oil contamination on floor slabs was bioremediated.
• Floors screeds were then re-instated and offices re-fitted.
• Air monitoring within the building was undertaken prior to, during and post remediation to demonstrate safe working conditions and effectiveness of remediation.

The Benefits

• Immediate risks to the building users were quickly established and monitored.
• Affected areas were quickly established along with an appropriate remediation scheme.
• A combination of physical removal of contamination and bioremediation was utilised to provide the most economic and technically robust solution.
• Disruption to building users was limited with much work undertaken out of hours.
• The building was returned to full use in less than three months.