What happened?
Gaea responded to a recent oil spill in Co Cavan
Cause
A family in Co Cavan discovered a strong odour in their garage and a wet stain around their boiler. Further investigation revealed staining to the bricks on the rear wall of the garage. Soon after the lawn near the garage began to die off. The cause turned out to be a failed component on the burner apparatus inside the boiler cabin.
It was estimated that around 200 litres of home heating oil had been lost over a period of around five days.
What did we do first?
Response
The family contacted Gaea via our Dublin office 01 2330222 and spoke with one of our project managers. Detailed advice was given of how to make the system safe, preventing further loss. Arrangements were made for a scientist to attend the property the following morning.
Investigation
A thorough investigation of the cause of the spill was carried out in the first instance. This was followed by a detailed soil and structures investigation to determine what had been impacted by the oil spill and to what degree. Several soil cores were removed to determine the depth of contamination and allow for the collection of some soil samples for analysis.
What we found?
Gaea found that the rear third of the garage floor had been severely impacted by home heating oil. Heating oil had leached through the brickwork into the soils below the lawn. The neighbours were protected by a French drain along the boundary. This effectively created a barrier, preventing further migration. However, the excess water being brought on site was an issue that needed appropriate treatment.
How did we fix it?
Following relocation of the boiler and tank and making sure the family had on-going heating and hot water the garage floor was broken out and disposed of.
The impacted bricks of the garage were replaced.
The impacted sections of the garden were excavated to clean material and processed of at a properly licenced waste recycling facility.
Excess water was dealt with using oil water separators and granulated activated carbon filtration units.
How did we Validate
Nine soil samples were collected from the sides and base of the excavation both inside the garage and in the lawn area. These were placed in coolers and transported to a UKAS accredited laboratory for detailed analysis, in this instance for Speciated Total Petroleum Hydrocarbon Criteria Working Group.
Analytical results from the laboratory provided scientific evidence that any remaining residual hydrocarbons were well below industry recognised scientific thresholds for environmental & human health.
A validation / completion report was then compiled for insurers and the home owners detailing what had been carried out and that no further work is required.
Four skips of contaminated soil were removed then taken to a soil recycling facility rather than for disposal.
Final Outcome
Once validated, the excavations were backfilled with clean hardfill compacted in layers. The garage floor was restored with new concrete and a damp proof membrane.
A new tank base was created and poured in concrete. Once fully set, the original tank was reinstated on the new base. The boiler was relocated, checked over and connected to the tank.
Garden lawns were filled with imported topsoil, raked out, then laid with fresh garden turf ready for the family to enjoy.
