Initial situation

As the upgrading plants were shut down, the exploration and removal of the contaminated deposits caused by mining began. Depending on the way the area had been used, and the initial contamination, over time the soil beneath the sites had become contaminated to varying degrees. This was the situation at the former Lauchhammer coking plant site.

Approach

When implementing the rehabilitation concept it was necessary to consider whether it should involve complete removal with disposal of the material elsewhere, and filling of the cut, or an alternative method.
Extensive exploration work and hazard assessments of the site showed that there were seven different areas that had been contaminated by after-use. With the final exploration of the central coking oven area and the peripheral areas, it was possible to define the total quantity of material that would have to be moved 763,000 m³.

Result

Altogether, a total of 144,000 m³ of contaminated soil and rubble were removed from other parts of the site and deposited and graded, then sealed with a 2.3- meter surface layer, on a total area of 16.9 hectares comprised by the central coking oven and tip G sections.
In both sections an appropriate surface water drainage system was installed taking account of the fact that the ground water level is near the surface. The implementation of this option resulted in a considerable potential for cost reductions.