Effective Wastewater Treatment for the Saxon Switzerland National Park


Bastei Mountain Hotel Relies on Environmental Technology by DAS Environmental Expert GmbH

(Dresden, August 14, 2017) The “Berghotel und Panorama Restaurant Bastei” (Bastei Mountain Hotel and Panorama Restaurant) is located high above the Elbe Valley on a rocky plateau in the famous Elbe Sandstone Mountains. It is located in the midst of the central area of the Saxon Switzerland National Park, where strict environmental protection regulations are upheld. As one of Saxony’s most prominent attractions and famous for its photo opportunities, the Bastei attracts close to 1.5 million visitors each year. In August 2017, Dresden DAS Environmental Expert was contracted by the Bastei Mountain Hotel to equip the property with a new water treatment plant. 

The Location’s Particular Challenge 

This particular location posed a double challenge for the Dresden environmental technology specialists. First, it was necessary to design the new plant’s capacity so that it processes the 4‑Star mountain hotel and restaurant’s wastewaters, as well as the wastewaters of the public restrooms within the area. Typically, wastewater streams are subject to sharp daily and seasonal fluctuations which had to be accounted for during the project’s conception. Secondly, the treatment plant is located in the central area of the national park and the wastewater pipe for the treated wastewater runs though canyons and the national park directly into the Elbe River. Accordingly, water authorities set stringent requirements concerning applicable limit values. 

High Quality and Performance Standards

The owner and managing director of the Bastei Mountain Hotel, Dieter Schröter entrusted the project’s planning to the specialists of DAS Environmental Expert. “We have the highest standards for the best service and quality for our guests,” Schröter says. “We do not make any concessions concerning our wastewater treatment. It was our goal to do more than meet the required limit values; we wanted to achieve optimum results. Clean water is essential to this unique Saxon Switzerland National Park. We want to contribute our best. The old wastewater treatment plant was no longer able to meet our standards, thus we approached DAS Environmental Expert.”

Efficient Technology for Clean Water

After initial discussions in 2012, the environmental technology specialists first examined the most appropriate technologies for the Bastei Mountain Hotel’s wastewater treatment.  Together, Dieter Schröter and the water authorities decided to use the Membrane Bio Reactor (MBR). This technology features two aerobic aeration tanks working parallel to each other where organic and nitrogen compounds degrade microbiologically. Plant construction started in fall 2015, where DAS Environmental Expert configured the aeration tanks to provide high operational safety while, at the same time, ensuring the necessary adaptability to seasonal fluctuations. 

Each aeration tank features two membrane cassette modules that are submerged in the tank. The membranes with a membrane pore size of 0,45 µm are highly efficient and separate sludge and bacteria, a procedure called “cold hygienization”, which provides additional safety to the environment from the treatment plant to the Elbe River.  The extremely small pore size, however, requires thorough mechanical pre-treatment of the accumulated wastewaters.

“The Bastei is a popular destination among hikers,” DAS Project Manager Kerstin Ilgen says. “Particularly at the public restrooms where we were dealing with high volumes of solids. It seems some hikers simply clean their hiking shoes with paper towels or large amounts of toilet paper and dispose of the towels via the toilets.  So, in advance, we separate all solids larger than 2 mm from the wastewater using a fully automated worm-screen. The wastewater then flows into a buffer tank, and then pumps pass it along into the aeration tanks where the actual degradation process starts.”

The system is designed for 450 resident units and releases up to two cubic meters (528.34 gallons) of cleaned water into the Elbe River on an hourly basis.

Clean Water and Clean Air Thanks to Dresden Environmental Technology Experts

“The MBR-technology is, in comparison to other solutions, more cost and maintenance intensive, however, the treated wastewater achieves process water quality,” Ilgen says. “This is how the stringent limit values are reliably met at all times.” Not only is the water quality securely guaranteed, the air quality is better, too.“Odor emissions that occurred with the old treatment plant no longer occur,” Ilgen says, “as many visitors have positively stated. This side-effect of the new treatment plant, of course, contributes to the quality of the stay at the Bastei.”

Expert and Reliable Partner for Optimum Results

Since spring 2016, DAS Environmental Expert technicians have continued to service the Bastei Mountain Hotel wastewater system based on a service and maintenance contract.  The technicians service the system once a month and carry out a thorough review once a year. “We are very satisfied with our new plant – it is small, compact and efficient,” Bastei Mountain Hotel owner Dieter Schröter says. “It could not be any better. Since the planning stage, DAS Environmental Expert has been a reliable partner, whose expertise we can trust.”