Preliminary investigations of contaminated sites may be necessary as a basis for a construction project or may be ordered by the environmental authority in accordance with the provisions of the Contaminated Sites Ordinance (AltlV). On the basis of a historical investigation, a technical investigation is carried out as a central step, in which explorations are made with excavators or drilling equipment and samples are analysed in the laboratory.
The results are evaluated by the contaminated site expert, with the following cases being possible:
- If no contaminations are found, the site is deleted from the Cadastre of polluted Sites (KbS).
- If there is pollution without harmful or tedious effects, the entry in the Cadastre remains, but no further measures are necessary.
- In more problematic cases, the site is classified as requiring monitoring or remediation, and further investigation steps are required (e.g. groundwater investigation, detailed investigation, remediation investigation).
- If the site is designated building land, the results can be used at the same time to clarify the requirements for future construction projects and to estimate the expected costs of remediation.
As contaminated site experts, we plan and manage all investigation steps in cooperation with experienced probing companies and laboratories, prepare the necessary expert reports, represent the interests of our clients vis-à-vis the authorities and support them if they are entitled to reimbursement of the investigation costs in accordance with the polluter-pays principle.
Former landfill site Beierschen
The site is a former gravel pit that was used as a municipal landfill between 1969 and 1977. In addition to domestic and construction waste, commercial and industrial waste was also deposited. On behalf of the municipality Simultec AG carried out the preliminary investigation of the contaminated site in several stages. Subsequently, seepage water and adjacent springs were monitored for several years. The results showed that there is no danger to the groundwater nor springs, so that no remediation was necessary and the monitoring could be stopped.
Client: Community of Hittnau
Project period: 2008 to 2017
Suspected contaminated site due to textile cleaning (CHC site)
Since the residential and office building in Dietikon has been equipped with a textile cleaning facility since 1974, there was a strong suspicion of contamination of the subsoil and groundwater with chlorinated hydrocarbons (CHCs). On behalf of the house owner Simultec carried out the preliminary investigation ordered by the Zurich Environmental Office AWEL. As required by the so-called Chloronet guidelines in such cases, the investigation comprised three steps, namely a historical investigation, an investigation of the subsoil with solid matter and pore air analyses at the presumed infiltration points and an investigation of the groundwater. The results turned out to be positive for the landowner: In all three compartments only trace contaminations of tetrachloroethene were found. The entry in the Cadastre of polluted Sites could be deleted.
Client: Private homeowner
Project period: 2017 to 2018