Life-Threatening Contaminated Sites Require Meticulous Procedures

In 2019, Ginger HPC was commissioned to prepare an environmental and geotechnical assessment for the replacement of wastewater sewers beneath the Buttermarkt as part of planned road reconstruction. Even the mere suspicion of anthrax pathogens makes opening the soil particularly dangerous—and for good reason: anthrax pathogens are classified as biological warfare agents. Protecting human life and health therefore has the highest priority.

Frederik Arnold, geologist and project manager, explains:
“Of course, we worked meticulously through the available data and, together with highly specialized equipment providers, were able to define protective clothing and measurement procedures. Despite all precautionary measures, trust within the team was essential, especially for the first test drillings.

I assembled the team from a few very experienced Ginger HPC employees and former fellow students working in the drilling crew—we have known each other for years and know we can rely on one another. The nights before the first drilling were still sleepless, and the relief after the first successful explorations and measurements was immense.”

Together with his colleague Hanna Kim, a water and environmental engineer and the second project manager for this project, Frederik Arnold has since established a routine for the measurements. The safety standards were extremely high, and the team members are recognized as experts in this field. While Frederik Arnold is responsible for planning field operations, selecting precisely fitted protective equipment, and preparing contaminated site assessments, Hanna Kim oversees geotechnical reports, groundwater calculations, coordination with authorities, and traffic safety measures.

From Theory to Practice: No Room for Grey Areas

At the beginning of the project, construction personnel received detailed instructions on the protection concept developed by project manager Arnold. The extensive equipment can be intimidating, so part of his role was to reduce fears and build confidence in the safety concept. In addition, a so-called black-and-white zone was established to ensure the protection of both the environment and local residents. Soil extracted with specialized drilling equipment is dewatered in tents over several days, properly packaged, and then disposed of at a hazardous waste incineration facility.

Precision at Depth

During site investigations, the Ginger HPC team discovered—alongside contaminated materials—the lower section of a gasometer that had been installed three meters below the surface and was not visible. Through historical research combined with drilling and probing, the location, design, and filling material of the gasometer basin were precisely determined, allowing obstacle removal to be carried out according to the work and safety plans. The team can state with some pride that their calculated location of the gasometer basin deviated by only 0.5 meters. The construction and filling material corresponded exactly with the materials predicted during the historical investigation.

A Look at the Present

Obstacle removal has now been completed, and sewer construction is proceeding based on our geotechnical reports and our work and safety plan, carried out by highly specialized contractors. A joint venture between BAUER Resources GmbH (BAUER Umwelt division) and STRABAG AG (Transportation Infrastructure division) is performing the work on site. Once a week, staff from the Ginger HPC Bremen office travel to the site to conduct additional safety inspections. After all, monitoring is good—but when dealing with highly hazardous risks, double-checking is even better. When it comes to safety, we make no compromises.

We have since become a key contact point for hazardous contaminated site issues throughout the region and prepare expert reports on environmental remediation and land recycling. Our motivation is clear: we aim to protect the environment from pollution and the dangers of the past—and above all prevent new contamination. This principle guides every step we take.

Work in Progress: Continuous Innovation at the Site

Our work at the Buttermarkt is a balancing act. We are proud to enable safe construction and to remove contamination in an environmentally responsible way, yet the path is filled with challenges—such as the enormous time and cost required for soil treatment and the frequently overburdened infrastructure of waste incineration facilities. Therefore, we continue to think ahead: how can the process be optimized, made even safer for people and the environment, and designed so that it can be transferred to other sites facing similar contamination challenges?

During brainstorming sessions, many approaches are explored. One idea is to cast the contaminated soil into epoxy resin blocks. Anthrax spores cannot escape from these blocks, allowing safe storage in landfills without the need for incineration.