How industrial waste has been handled over the years

Published on 01/07/2021

In the period up to around 1945, the chemical companies operating in the Basel area, similar to other types of industries, mainly disposed their waste in the Rhine. Solid waste was liquefied in so-called sludge mills and also disposed of in the Rhine. When legal regulation prohibited this practice, the waste was deposited in gravel pits in Switzerland but also in Germany and France. This practice was applied from about 1940 to 1961. From 1961 to 1996, the waste was deposited in the hazardous waste landfills in Bonfol, Koelliken and Teuftal. At that time there were no special furnaces for thermal treatment, and it was not until 1980 that the technology of incinerating chemical and production waste became available on a large scale, a technology that is still used today.

Particularly in the last decade of the 20th century, it became apparent that the depositing of chemical and production waste in pits was problematic with regard to the protection of groundwater and drinking water and that in individual cases there was a need for action. In 2001, therefore, the companies of the Basel Chemical Industry (bci) – in consultation with the authorities of Germany, France and Switzerland – founded the association Interessengemeinschaft Deponiesicherheit Regio Basel (IG DRB). On behalf of its member companies, IG DRB carried out the investigations of the former landfills in the trinational Basel region. A total of 12 landfills were investigated, and the results of the investigation were made available to the responsible authorities, who assessed the results and decided on the further course of action and the measures to be taken. For the individual landfills, the responsible bodies were formed by the companies concerned. They carried out, and still carry out, the necessary investigations, monitoring and remediation work in close consultation with the authorities.

At other landfills (Le Letten and Roemisloch [F]) the authorities did not demand any remediation measures. Nevertheless, the affected companies BASF, Novartis and Syngenta joined forces to voluntarily clean up both landfills to form the Groupement d’intérêt pour la sécurité des décharges de la région bâloise (GI DRB). The waste stored in the landfills in Alsace was excavated in 2010/11 and disposed of in accordance with the state of the art (Le Letten: 79,270 tonnes, Roemisloch: 7,633 tonnes).

The necessary remediation of the Bonfol and Koelliken hazardous waste landfills also involved the formation of sponsorships. Koelliken was rehabilitated by the Cantons of Aargau and Zurich, the City of Zurich and the bci. The bci Betriebs AG was responsible for the remediation of the Bonfol landfill and carried out the remediation on behalf of the Basel chemical industry. In both cases, the waste has now been excavated and disposed of properly (Koelliken: 664,100 tonnes, Bonfol 286,561 tonnes).

The area of the STEIH wastewater treatment plant is not a landfill in the true sense, but a contaminated industrial area. With the remediation of the soil at the ARA STEIH, Novartis remediated a contaminated site that was not caused by it. For the complete remediation of the ARA STEIH site, approx. 788,000 tonnes of contaminated soil was excavated and disposed of properly. This more than doubled the excavation volumes of Bonfol (286,561 tonnes) and significantly exceeded those of the Koelliken hazardous waste landfill (664,100 tonnes).

With the remediation of the STEIH site, another milestone has been reached. However, it will take several more years before all the legacy burdens are eliminated. What has been done in decades can only be corrected with great effort and not in a short period of time.