A major leak from underground storage tank (USTs) at an operational petrol filling station near Milan, resulted in a significant hydrocarbon contamination plume extending 50 m outside the site boundary. The leaking USTs were excavated, however a significant mass of contaminant remained sorbed to the soil, providing an ongoing source of contamination.
A remedial solution was required that tackled both the contaminant source and addressed the migrating plume.
Previous attempts to remediate the contamination included dual phase vapour extraction (DPVE), pump and treat (P&T) and air sparging. However; ongoing, these proved to be ineffective after their initial period of good contaminant removal.
PetroCleanze®, a powerful desorption reagent, was applied to an area of the highly contaminated source zone to release the sorbed contaminant and LNAPL bound to soil. Once in solution, the contamination was physically extracted by a vacuum truck from the same well where product was applied.
Additionally, a full scale barrier of ORC-Advanced injections was placed at the site boundary to treat contamination migrating offsite.
Stand alone physical extraction systems are unable to remove contamination bound to soil. PetroCleanze however desorbs bound contamination into solution allowing for physical extraction of the desorbed mass.