Contaminated Site Remediation

Sustainable Contamination Remediation as a Model

In Clausthal-Zellerfeld, on the site of the former "Werk Tanne" explosives factory, we are setting a strong example for sustainable contaminated site remediation - with the clear goal of creating ground for the future together.

At the "Werk Tanne" site, a milestone in environmental technology was achieved with the opening of Europe's largest constructed wetland. Lower Saxony's Environment Minister Christian Meyer described the project as:

an outstanding example of how modern technology and nature work hand in hand to protect water in our region.

Nearly 80 years after the end of World War II, this makes a decisive contribution to dealing with the legacy of National Socialism. The former factory, which was one of the largest explosives and munitions plants of the German Reich between 1935 and 1944, left behind heavily contaminated soils and polluted seepage water. We consciously accept this responsibility today.

Constructed Wetland: Technology in Harmony with Nature

The innovative system is based on a near-natural purification process, in which plants, soil and microorganisms work together. In so-called Constructed Wetlands – a combination of water surfaces and reed beds – rainwater and snowmelt are collected and gently purified. The process is efficient, cost-effective and impresses with an excellent ecological balance. Thanks to the natural slope of the terrain and biological purification processes, a sustainable cost-benefit ratio is created, which is particularly important for long-term remediation projects. With the completion of the second phase of the system, it is ensured that contaminated seepage water is comprehensively purified before entering the Pfauenteiche – part of the UNESCO World Heritage Site Upper Harz Water Management System.