Former admixed drilling sump at an abandoned wellsite. Soil impacts were from 1 meter below grade (mbg) to 3 mbg, consisting primarily of toluene.
Access road to the site was partially reclaimed, which limited the remedial options available (ie/ limiting truck transport of contaminants).
Impacted soils were excavated and an Allu bucket was used to homogenize soils and break up large soil clumps. The blended hydrogen peroxide was applied directly to the soil while the excavator was flipping and kneading the soil. A total of 5,000 litres of blended 20% EHP (enhanced hydrogen peroxide) oxidant was applied on the soil for treatment.
A closure-based in-situ chemical oxidation (ISCO) remediation was conducted at a former gas station in Southern Alberta to address BTEX, F1, F2, and PAH contamination in 6,630 m³ of impacted soil, bedrock, and groundwater, including off-site impacts beneath residential properties. Due to infrastructure constraints and vapour risks, a Remediation Train® approach was implemented, starting with a soil vapour extraction (SVE) and air sparge system, followed by a ISCO program with a 3-meter injection radius. Nested injection wells targeted various depth intervals, with careful scheduling around residential activity. Over 45 days, 1.6 million liters of 10% EHP (enhanced hydrogen peroxide) was injected using TRIUM’s ChemOx® process, achieving daily blend volumes of >35,000 L. The treatment successfully met regulatory groundwater quality guidelines, managed vapour risks, and was recognized as an industry-leading process by consultants, with no negative impact on the community.