Dismantling of former Erzenberg foundry, Liestal

The site of the former Erzenberg foundry in Liestal is being redeveloped. The old existing foundry buildings will have to make way for a residential development. Ecosens AG has been supporting and advising the client on building pollutants and contaminated sites since 2016.

An extensive building check and subsequent detailed investigations revealed various components and materials containing asbestos, PCBs and PAHs. The main deposits were mainly asbestos cement products (corrugated sheets, façade panels) and window putty. However, materials containing asbestos were also found in the machines and furnaces of the former foundry. Black lying dust as a result of the production activities in the foundry and other halls required special handling. This was heavily contaminated with HC C10-C40 and heavy metals and was found on the floors, walls, machines and cable trays, among other things. Before dismantling, the buildings had to be cleaned to such an extent that the machines and buildings could be dismantled and the building materials recycled without incurring additional costs due to dust accumulation and that the dust could not be transported during the dismantling process. Ecosens AG tendered for the remediation of pollutants in the buildings and the subsoil. The remediation of the buildings took place in 2023 and was professionally supervised by Ecosens AG. The tall foundry furnaces and machines of the former foundry posed a particular challenge. These could often only be examined and assessed in more detail during dismantling on site. Dismantling, dismantling and accompanying investigations therefore went hand in hand.

Parallel to the demolition of the buildings and now following on from this, the next challenge was imminent - the remediation of the use-related contamination in the concrete floors and the contaminated soil, with the aim of completely decontaminating the area of the future residential development. This work is being supervised by our Contaminated Sites + Geology department and is expected to continue until the summer.

Contact person for building pollutants 
Ansgar Schlöffel, sen. Project Manager Building Pollutants

Contact person for contaminated sites
Melanie Tschopp-Vögtli, Head of Contaminated Sites + Geology Department