Spill at Commercial Premises
The 1500-litre capacity oil tank at the offices was vandalised shortly after it had been filled, and all its kerosene heating oil was lost to ground. Strong odours of oil were noted in the room used for training. The tarmac drive was heavily impacted with oil and oil was found in drains, which were pumped out.
A site survey was conducted. The tarmac drive was found to be disintegrating. Elevated but not very high concentrations of volatile organic compounds (VOCs) of 3 parts per million were found in the air of a training room. A borehole in this training room returned soils which released VOCs to air of 30ppm, showing some impaction to sub surface soils. External investigation revealed a network of drains external to the offices that had acted as preferential pathways for oil migration.
A vapour abatement unit was installed in the training room.
Risks and Remediation
To mitigate the risk of further migration of oil to the offices the tarmac and bulk of oil impacted soils were excavated. To mitigate impaction of the building materials by oil and subsequent to air, a trench was dug against the foundations and they were scrubbed with surfactant. Resultant oily water was pumped out. Removed soils and oily water were removed to licensed disposal.
The ground was backfilled with hard core with a section of new tarmac drive over.
Validation was by field monitoring and submission of soil and air samples for analysis to a UKAS accredited laboratory, and to target levels for air agreed by Environmental Health.Back