Remediation of the Le Letten landfill

PROJECT DATA

Region: Alsace/France
Client: HIM GmbH, on behalf of GIRB c/o BASF
Participants: ARE Deutzen GmbH
Construction period: 2011
Project value: €4.50 million

WORK PERFORMED

  • Pretreatment of 35,000 tons of material at the
    soil treatment facility in Deutzen
  • Thermal treatment and subsequent disposal of
    35,000 tons of excavated material in total

BACKGROUND

Die frühere Deponie Le Letten liegt im elsässischen Hagenthal le Bas (F), rund 300 m von der Schweizer Grenze bei Schönenbuch im Kanton Basel-Landschaft (CH) entfernt. In den 1950er und 1960er Jahren wurden sowohl Aushub und Bauschutt als auch Gewerbe, Industrie- und Chemieabfälle deponiert.

The former Le Letten landfill is situated in Hagenthal le Bas Valley in Alsace (F), roughly 300 m from the Swiss border, near Schönenbuch in the canton of Basel-Landschaft (CH). It was used in the 1950s and 1960s to store excavated soil, as well as commercial, industrial and chemical waste.

GIDBR commissioned HIM GmbH with remediation of the former landfill site Le Letten.

A central component of the remediation project was to dispose of the contaminated landfill contents.
These heterogeneous materials were described as a ‘mixed layer’. Based on the original volume estimate, the total quantity of mixed layer material was to be around 20,600 m³ (= approx. 35,000 t).

A preliminary investigation indicated that the mixed layer material consisted mainly of contaminated mineral substances (soil material and rubble), interspersed with production waste from the chemicals industry.

Moreover, depending on the degree of contamination, the soils located immediately beneath the mixed layer material in the adjacent alluvium needed to be excavated and disposed of. The volume of this material at the base of the landfill and in the boundary areas was estimated to be approx. 3,000 m³ (= around 5,100 t).

REMEDIATION WORK

The HIM GmbH disposal concept included decontamination of the mixed layer material and the alluvial soil in the thermal soil treatment facility at ARE Deutzen GmbH in Deutzen/Saxony, Germany, depending on the degree of contamination.

The entire deposit was enclosed within a structure and an external company removed the soil. It was then placed in an airlock, fed into containers and transported for thermal treatment at the facility operated by ARE Deutzen GmbH near Leipzig.

Transportation of the material from the Le Letten landfill to Deutzen took place in ‘inter-modal’ (road-rail-road) gas-tight containers in order to comply with the facility’s acceptance thresholds.

Around 35,000 tons of soil material were delivered in the period 02/2011– 10/2011, pretreated and then disposed of by then end of 2011.

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