Case study : advanced integrated in situ technologies outperform traditional remediation techniques

Abstract

RGS 90 has been commissioned by the Swedish Armed Forces to remediate a large fuel storage facility servicing the military. The facility housed a variety of petroleum products for over 40 years and several documented release incidents resulted in the contamination of a 50,000 m² area. The largest known event occurred in 1958, where an explosion caused the release of 14,000 m³ of various petroleum products. During the clean-up, only 8,000 m³ of the product was recovered while an estimated 6,000 m³ reached the surrounding environment. The client initially proposed a remedial strategy consisting of biosparging and in-situ chemical oxidation using hydrogen peroxide; however, RGS 90 found these methods to be unsuitable for this site due to the geology of the area, which consists of impermeable and heterogeneous dense, rocky moraine. There are also safety risks and environmental hazards associated with the use of hydrogen peroxide. RGS 90 suggested an alternative method which was accepted by the Swedish Armed Forces and a pilot test was carried out in 2012. The results from the pilot tests confirmed that the use of ORC-Advanced and RegenOx would successfully remediate the extensive TPH contamination at the site. The data gathered from this pilot test allowed RGS 90 to refine and optimize the proposed full-scale treatment of the wider plume. The full scale remediation process started in December 2013 in area C and D. Sampling 6 month after injection shows that the target values have been achieved in almost all sampling points. During summer and autumn 2014, RGS 90 are planning for the full scale remediation process of the remaining areas, (B1-B3). The plan is to inject RegenOx and ORC-Advanced into the ground and groundwater and use multiphase extraction in the areas, where free phase product has been observed during the initial groundwater sampling.