Membrane biology from WABAG Switzerland for the Lauterbrunnen wastewater treatment plant

In Lauterbrunnen, a highly popular winter tourism resort in the Swiss Alps, the wastewater treatment plant is to be upgraded with modern and flexible membrane technology (MARAPUR® – the WABAG MBR process) in order to deal with seasonal peak loads. For the completion of this project, the local authority has turned to WABAG, which specialises in both MBR and plant modifications and enlargements in challenging circumstances. The contract was signed in September 2015.     

In the tourism off-season, the treatment plant handles the municipal wastewater derived from the roughly 3,000 local inhabitants. However, at peak times in winter skiing holidaymakers push the population figure up to around 12,500. Under these circumstances, the existing plant has become incapable of meeting the strict water protection requirements and is therefore about to undergo re-equipping and upgrading. WABAG is to replace the biodisc reactor technology used to date with a modern MARAPUR® membrane bioreactor system. This combination of activated sludge biology and ultrafiltration is able to cope with very large seasonal fluctuations while simultaneously securing all-year nitrification.     

WABAG was able to convince the client with a compact, tailor-made solution that took into account the limited amount of space available and could be ideally integrated into the current plant. The conversion work is to take place during full plant operation in two stages with start-up in 2017 and 2018.

The contract incorporates the design, engineering, delivery, installation and start-up of the electromechanical equipment and measurement systems for the membrane technology including the upstream fine sieves. WABAG will also be responsible for the disassembly of the old plant machinery.

 A specialist for difficult tasks: a MBR plant in a mountain cavern for Zermatt

The WABAG experts in Switzerland have already solved a similarly tricky assignment on an even larger scale in Zermatt at the foot of the Matterhorn. In this case, with regard to cleaning and capacity levels, the existing wastewater treatment plant was also no longer able to handle tourism-related peak loads ranging between 6,000 and 60,000 p.e. Therefore between 2011 and 2013, WABAG carried out a complete upgrade and also installed modern MARAPUR® – MBR technology.   

This project was further complicated by the location of the Zermatt treatment plant, which is situated in mountain caverns at a depth of up to 200m. In addition, the conversion work had to be completed during ongoing plant operation. With 60,000 p.e. the Zermatt facility represents the largest municipal membrane biology in Switzerland and following successful completion, was handed over to the Zermatt district authority in early 2014.