Remediation of contaminated subsoil under tight deadlines

In time-sensitive remediation projects, every day counts. Whether it’s acute contamination, construction delays, or even a halt to construction due to unexpected discoveries of hazardous substances or tight project timelines—these situations call for partners who can respond quickly, reliably meet regulatory requirements, and operate cost-effectively at the same time.  

At Sensatec, we specifically rely on drilling and injection methods that can be carried out quickly and on the use of long-acting, sustained-release active ingredients, which—in short campaigns—create remediation potentialat the site that remains effective for years. These approaches enable the rapid, safe, and cost-effective implementation of challenging remediation projects.

On a former industrial site in Schladen in the Western Harz Mountains, two heavily contaminated areas were identified during civil engineering work for a new building; these areas were contaminated with highly volatile aromatic hydrocarbons (cumene) to a depth of several meters.

The discovery led to a halt in construction and resulted in significant associated costs. In order to proceed with a planned change of use, the confirmed soil contamination had to be reduced quickly.

A narrow time window was available between the demolition of the old building structure and the start of new construction to investigate the extent of the cumene contamination and remediate it, as well as to address contamination at the edges and base of the excavation areas. Consequently, investigation results had to be obtained as quickly as possible, and the remediation plan had to be designed so that only a single treatment would be required, with the longest possible-lasting effect.

The investigation was conducted using MIP (Membrane Interface Probe) sampling. With this method, volatile contaminants in the saturated and unsaturated zones can be detected “online” in real time during the sampling process, using imaging techniques and without the need for sampling.

Based on the results of the MIP soundings, the multi-stage oxidizing agent Klozur CR was injected immediately afterward through a total of 23 injection boreholes.

The remediation work at the site was completed within 4 weeks. Subsequent groundwater monitoring in the former contamination center and in the groundwater discharge area confirmed the long-term success of the remediation. Construction was able to begin as planned.

Details of the exceptionally fast in-situ remediation: View reference project

When every day counts, what matters most is prompt treatment with long-lasting results and precise execution. Thanks to our many years of experience and our wide range of restoration services, we can deliver exactly that—quickly and efficiently.