Mercer Rosenthal has temporarily paused the restart of its kraft pulp mill in Rosenthal am Rennsteig, Germany, following reports of discoloration near the facility’s wastewater discharge point into the Saale River.
The mill was returning to operation after a scheduled maintenance shutdown of approximately four weeks when the issue was reported. As a precaution, Mercer Rosenthal suspended the startup process and wastewater discharge into the river.
The company said the wastewater is being held in on-site buffer tanks while the situation is investigated. Environmental authorities were notified and visited the site.
The Saale-Orla District Office said unknown substances entered the Saale on October 1 and attributed the release to an incident at the Mercer Rosenthal mill. Authorities reported strong odors and marked turbidity in the water, along with isolated dead fish.
As a precaution, the district imposed a temporary swimming ban on the southern section of the Bleiloch Reservoir between Harra and the Saale Bridge near Saaldorf. People and animals were also advised to avoid contact with the water pending further information.
By October 2, environmental officials said no further surface turbidity was visible at Harra or farther downstream. However, additional dead fish had been found, and authorities said part of the material appeared to have settled on the riverbed.
Laboratory testing was underway to identify the substances involved and assess any potential environmental or health risks.
Mercer Rosenthal Managing Director Christian Sörgel told MDR Thüringen that the company had found no indication that unauthorized substances had entered the Saale and disputed that an incident had occurred at the mill. Mercer said it remains in close contact with the relevant authorities and is taking measures to fully clarify the circumstances.
Mercer Rosenthal has an annual production capacity of approximately 360,000 metric tons of kraft pulp, primarily supplying customers in Germany and Italy. The mill also produces tall oil and lignin and operates a biomass power plant with 413 MW of thermal capacity and 57 MW of electrical capacity.
Mercer Rosenthal is part of Mercer International Inc., a forest products company with operations in Germany, Canada and the United States.
