OASE Living Water

Low-impact sludge removal for a body of water in a conservation area

Mission

The town of Georgsmarienhütte in Lower Saxony is home to a mill pond measuring 1 ha in size. The body of water has been declared a "Fauna-Flora Habitat (FFH) Area" and helps to protect and conserve 231 types of habitat and more than 1000 wild species of fauna and flora in Europe. The mill pond is mainly used for fishing.

Challenges

The particular challenge of the mill pond stems from its location in an FFH area, which requires especially delicate treatment of the natural environment. It was therefore not possible to approve dredging the sludge.

Over a period of 50 years, a sludge layer with an average thickness of 75 cm had formed. In 2011, fish started dying off in the body of water, which was only 45–65 cm deep.

Solution

SchlixX Plus was regularly applied in quantities of 0.5 t to 3 t over the next three years. Owing to the great success of this treatment, another 2 t of SchlixX Plus was applied in 2019 and then again in 2020.

Result

It was possible to reduce the total sludge layer by 32–58 cm, which constitutes a 43% sludge reduction. At the same time the organic content of the remaining sediment was reduced by approximately 60%. A variety of amphibians, dragonflies and others have established themselves at the pond during the treatment period. There is a stable community of macrozoobenthos in the pond, the mussels multiply and the fish are doing very well. It can be assumed that these measures prevented the town from the loss of its biotope at the Mühlenteich caused by the growing sludge layer in the Mühlenteich. Based upon these positive results a further amount of 1,5 t of SchlixX Plus has been applied in 2021. We will report about further news.

Products used