Previously excavated soil was stockpiled on-site. Contaminants in the soil included BTEX, F1, and F2. A total of 1,900 m3 of low to moderate PHC impacted mineral soil was stockpiled and 600 m3 of heavily contaminated organic/ topsoil was stockpiled separately.
Mineral soils and organic soils were segregated due to high variability amongst the two piles for PHC concentrations. A specialized mulcher was used for the project in order to ensure the greatest contact between the oxidant and the impacted soils.
Mineral soils had a total of three passes with 56,150 kg of 50% EHP (enhanced hydrogen peroxide) applied. Pilot test on the organic soils had a total of three passes and 3,600 kg of 50% EHP (enhanced hydrogen peroxide) applied.
A pipeline release at an active multi-well pad in Central Alberta required remediation due to BTEX, F1, F2, and PAH contamination in 2,000 m³ of impacted soil and groundwater, with remediation timeframes limited by site conditions. A staged risk-based in-situ chemical oxidation (ISCO) approach was implemented with a 3-meter injection radius, involving the installation of 52 injection wells and five permeable reaction trenches to facilitate groundwater extraction and oxidant circulation. A total of 17,500 liters of 12% EHP (enhanced hydrogen peroxide) was injected using TRIUM’s ChemOx® process, with injections timed during frost-cap months to maintain pressure. Results show a well-defined and shrinking plume, significant source area concentration reductions, and an approximate 90% decrease in PHC and PAH concentrations since project inception.