Client

A large facilities management company  

Services provided by our experts:

• Incident response & mitigation

• Contamination assessment and remediation

• Underpinning of protected structure

• Reinstatement  

• Project management

The Incident

Significant hydrocarbon odours reported in a protected structure in Co. Monaghan. A flexi hose at the oil burner had failed and an estimated 600 litres of oil had been lost to ground. The boiler was situated 40m downgradient from the building where odours were recorded. The escape of oil led to contamination impacting soils around the boiler house and oil vapours venting via a man-made tunnel underneath the protected structure. The building was sale agreed and required Seed working to extremely tight deadlines to ensure that the sale did not fall through.

The Solution

The Seed Environmental team were called in to carry out a site investigation to assess the extent and severity of the contamination plume. Seed deployed vacuum extraction units to alleviate odours while conducting non-invasive internal investigations, due to protected structure status of the building along with external window sampling survey. Seed identified the odour pathway as via an old access tunnel and disused lead pipework, external contamination was identified at a depth of 1.7m below ground level in the vicinity of the boiler house.

The Outcome

Following discussions with the local authority and engagement of a conservation engineer, Seed devised a remedial programme to excavate and underpin around the boiler house followed by an in-situ chemical oxidation treatment programme. Seed successfully excavated the gross contamination to a depth of 1.7m and fully removed the hydrocarbon odours from the protected structure.

During reinstatement works on the site, a new OFTEC compliant bunded oil storage tank and a new underground oil feed line was placed in protective ducting and flexi hoses were replaced.