Case Study - In-situ remediation of a petrol station
Background
During excavation works at a neighbouring property it was identified that a leak of diesel had occurred from a fitting on an underground
storage tank at a petrol filling station. Initial investigation and monitoring works were undertaken by another contractor. Following discussions with the Environment Agency, Oracle were appointed to
completed soil and groundwater remediation at the site. Due to the small size of the site, proximity to other properties and a main road as well as other business operating from the site, in-situ treatment was selected to minimise disruption.
Planning & Management
Oracle liaised closely with the site operator, neighbouring business, surrounding residents and Environment Agency to devise a remedial strategy that would achieve the remedial objectives with minimal disruption.
The works required the deployment of our Environment Agency permit, and boundary noise and VOC monitoring was undertaken to ensure compliance with the permit requirements.
Oracle also liaised with the local sewerage undertaker and utilised a trade effluent consent for the discharge of treated groundwater to
foul sewer.
Remediation
Oracle completed further monitoring of groundwater at the site and identified a region of contaminated soils and groundwater below
the forecourt.
A trench was cut through the impacted region, and vacuum excavation was used to install injection lances into the underlying soils to a depth of 2 m to avoid buried services. Lances were used to inject chemical oxidant solutions to treat hydrocarbon impacted soils in-situ and avoid the requirement for large scale excavations.
A groundwater treatment system was also installed and all pipework was buried below the forecourt to allow the continued operation of the petrol station and neighbouring business while the treatment system was operational.