Ever wondered where your bathwater ends up? The Wastewater Treatment Plant Rosental is Leipzig’s largest wastewater treatment facility. It’s right here in front of you.
The Wastewater Treatment Plant Rosental has a long history. Wastewater disposal in Leipzig dates back to the 13th century. Streets were paved and open ditches in the street center carried rainwater and waste.
Fast forward to 1740. A central drainage network was built. In 1833, the city began constructing a large-scale sewage system. This system directed flow into the city moat, the Pleisse, and the Elstermühlgraben. Leipzig still uses a combined sewer system. This means sewage and rainwater are drained together.
The Wastewater Treatment Plant Rosental began operations in November 1894. It was one of Germany’s first treatment plants. The plant sits at a geographically advantageous low point. Wastewater flows here mostly by gravity.
The Leipziger Wasserwerke operate 25 treatment plants. Wastewater Treatment Plant Rosental is the largest in the city and region. It sits at the northwestern end of Rosental park. The park is part of the Leipzig floodplain forest. The plant covers about 25 hectares. The Weisse Elster River flows through it. The plant’s elevation is 103 meters above sea level.
The canal network helps prevent flooding. It can store water and release it gradually to the plant. Upon arrival, water undergoes mechanical cleaning. It passes through a screen and grit chamber. Then, in preliminary clarification, finer solids settle.
Phosphorus is removed using an iron-III-chloride-sulfate solution. Then, in four aeration basins totaling 97,000 cubic meters, microorganisms remove phosphorus, nitrogen, and carbon. In eight settling tanks, sludge settles. Cleaned water flows into the Neue Luppe River.
Part of the sludge returns to biological treatment. The rest breaks down in digesters at 37 degrees Celsius. This process produces methane, carbon dioxide, and water. The methane powers a combined heat and power plant. This provides electricity and heat for the facility. The remaining sludge is dewatered and composted. The plant cleans an average of 110,000 cubic meters of water per day.
Leipzig expanded the Wastewater Treatment Plant Rosental in 2017. The expansion will increase the treatment capacity from 550,000 to 710,000 population equivalents. The expansion includes a new mechanical stage and an expansion of the biological stage. The biological cleaning stage will be expanded to two stories by 2028. The mechanical cleaning stage will be completely rebuilt between 2027 and 2032.
In 2022, the Leipziger Wasserwerke invested 73 million euros in their water systems. About 42 million euros went to wastewater projects. These projects directly support environmental and water protection. Current projects include upgrades to the Dölzig and Gotha treatment plants. There are also upgrades to the inlet collection and Elster culvert in the Klingerhain area.
The Wastewater Treatment Plant Rosental processes about 110,000 cubic meters of wastewater daily. The expansion will increase capacity by 30%. The investment volume totals 240 million euros. Measures to protect biodiversity include over 6,800 square meters of new plantings. There are also nesting aids for bats. The project is scheduled for completion by 2032.
So, the next time you turn on the tap, remember the journey your water takes. The Wastewater Treatment Plant Rosental is essential. It keeps Leipzig clean. It protects our environment.