Complexe verontreiniging opgelost met combinatie in-situ technieken

The Coveliers Building in Berchem (Antwerp) is a well-known building. It houses several government institutions, including The House of Sports. Until 1973, this location was the site for several industries. Although the exact cause is still unknown, these left contamination with chlorine solvents in the soil and groundwater under what is now the building's car park. This presented the Province of Antwerp with a challenge. How do you quickly, but safely, remediate a complex soil contamination in a difficult-to-access location such as this extremely frequently used car park in the middle of the city, where excavation is not an option? Next door, they had been trying to remediate the soil for 10 years, without success. That's why opted for a combination of in situ techniques, which was effective.

In-situ chemical oxidation (ISCO), compressed air injection and soil air extraction

The contamination was found up to a depth of 15 meters deep and in both soil and groundwater. Our strategy for soil remediation was a two-stage procedure. First, we remediated the soil and groundwater with in-situ chemical oxidation (ISCO). This already made the soil and groundwater cleaner by a factor of three. Then we removed the remaining contamination from the soil and groundwater using compressed air injection (air sparging), combined with soil air extraction. We injected air at depths of 10 and 15 meters to remove the contamination from the groundwater and move it to the unsaturated zone. There we captured the contamination by soil air extraction. This way, we successfully removed more than 75% of the contamination and completed the remediation of the site in a period of less than 5 years.

Smart construction of wells, piping and treatment plant

Of course, you can't just start digging in the middle of the city to build the wells and piping needed for a cleanup like this. So we made a virtue of necessity. The installation work for the in-situ remediation was done in parallel with the planned renovation of the parking lot. For the reconstruction of the parking lot, the pavement and the existing sewer system were removed. In this temporary, unpaved and cleared area, we installed the 55 injection filters, 15 compressed air injection filters and 11 soil air extraction filters, including the associated underground piping. Once this remediation infrastructure was completed and the parking lot repaired, we could very simply do our work without disturbing site activities. A win-win, in other words. We designed and built all the remediation facilities ourselves.

In this project the added value of Mourik is very apparent. To begin with, we are very proficient in many remediation techniques and we can perfectly assess what the best solution is in which situation. We also know how to combine techniques, such as in this case in-situ chemical oxidation (ISCO), followed by compressed air injection and soil air extraction, for even better results. We have our own laboratory and a workshop for design and engineering of remediation plants. This is typical Mourik: we think in solutions from A to Z and like to relieve our customers from start to finish. With knowledge, with skill and always our 'can do' mentality.