Project Overview: In the years 2015 to 2017, AC Materials undertook the challenging task of reMediating the contaminated soil and groundwater at the former Martens Energie gas station along Rue de Mons in Hornu. The site was polluted with gasoline and petroleum compounds, specifically mineral oil, BTEX, and MTBE.
Complex Location: Situated alongside a busy thoroughfare near a hospital parking lot, the contaminated site presented unique challenges. A high-voltage cabin and various underground pipelines (electricity feed cables to and from the high-voltage cabin, medium-pressure gas, enclosed current cables, concrete prefab channel, lighting pole, etc.) were present on the premises.
Excavation and ReMediation Strategy: Approximately 1,250 m² of the area needed excavation. The process began with a dig down to 5 m below ground level in a slope configuration. Subsequently, a sump pump system was installed at the base of the slope.
The central part of the zone was further excavated down to 9 m below ground level. To maintain the stability of the slope, the section at the base of the slope was excavated in segments.
Deeper contamination was identified in soil samples taken from the slope near the high-voltage cabin. The area surrounding the cabin was subjected to a tube-based excavation down to 9.5 m below ground level.
In total, 7,500 m³ of soil was excavated, with 750 m³ removed using tube-based excavation. Approximately 10,550 tons of contaminated soil were transported to an external soil treatment center.
Following the excavation works, the entire zone was backfilled with clean stockpiled soil and imported fill material.
In-Situ ReMediation Strategy: Based on observations during civil engineering works and a pilot test, an in-situ reMediation concept was formulated. A pressurized air injection was performed on 29 injection filters, accompanied by soil vapor extraction. Extracted air and condensed water were purified using activated carbon filters.
